./tools/notsd-move

30 files changed, 10442 insertions, 0 deletions

diff --git a/src/systemd-nspawn/.gitignore b/src/systemd-nspawn/.gitignore
new file mode 100644
index 0000000000..85c81fff24
--- /dev/null
+++ b/src/systemd-nspawn/.gitignore
@@ -0,0 +1 @@
+/nspawn-gperf.c
diff --git a/src/systemd-nspawn/Makefile b/src/systemd-nspawn/Makefile
new file mode 100644
index 0000000000..c0fc3bd98e
--- /dev/null
+++ b/src/systemd-nspawn/Makefile
@@ -0,0 +1,93 @@
+#  -*- Mode: makefile; indent-tabs-mode: t -*-
+#
+#  This file is part of systemd.
+#
+#  Copyright 2010-2012 Lennart Poettering
+#  Copyright 2010-2012 Kay Sievers
+#  Copyright 2013 Zbigniew Jędrzejewski-Szmek
+#  Copyright 2013 David Strauss
+#  Copyright 2016 Luke Shumaker
+#
+#  systemd is free software; you can redistribute it and/or modify it
+#  under the terms of the GNU Lesser General Public License as published by
+#  the Free Software Foundation; either version 2.1 of the License, or
+#  (at your option) any later version.
+#
+#  systemd is distributed in the hope that it will be useful, but
+#  WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+#  Lesser General Public License for more details.
+#
+#  You should have received a copy of the GNU Lesser General Public License
+#  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+include $(dir $(lastword $(MAKEFILE_LIST)))/../../config.mk
+include $(topsrcdir)/build-aux/Makefile.head.mk
+
+bin_PROGRAMS += systemd-nspawn
+systemd_nspawn_SOURCES = \
+	src/nspawn/nspawn.c \
+	src/nspawn/nspawn-settings.c \
+	src/nspawn/nspawn-settings.h \
+	src/nspawn/nspawn-mount.c \
+	src/nspawn/nspawn-mount.h \
+	src/nspawn/nspawn-network.c \
+	src/nspawn/nspawn-network.h \
+	src/nspawn/nspawn-expose-ports.c \
+	src/nspawn/nspawn-expose-ports.h \
+	src/nspawn/nspawn-cgroup.c \
+	src/nspawn/nspawn-cgroup.h \
+	src/nspawn/nspawn-seccomp.c \
+	src/nspawn/nspawn-seccomp.h \
+	src/nspawn/nspawn-register.c \
+	src/nspawn/nspawn-register.h \
+	src/nspawn/nspawn-setuid.c \
+	src/nspawn/nspawn-setuid.h \
+	src/nspawn/nspawn-stub-pid1.c \
+	src/nspawn/nspawn-stub-pid1.h \
+	src/nspawn/nspawn-patch-uid.c \
+	src/nspawn/nspawn-patch-uid.h \
+	src/core/mount-setup.c \
+	src/core/mount-setup.h \
+	src/core/loopback-setup.c \
+	src/core/loopback-setup.h
+
+nodist_systemd_nspawn_SOURCES = \
+	src/nspawn/nspawn-gperf.c
+
+gperf_gperf_sources += \
+	src/nspawn/nspawn-gperf.gperf
+
+systemd_nspawn_CFLAGS = \
+	$(ACL_CFLAGS) \
+	$(BLKID_CFLAGS) \
+	$(SECCOMP_CFLAGS) \
+	$(SELINUX_CFLAGS)
+
+systemd_nspawn_LDADD = \
+	libsystemd-shared.la \
+	$(ACL_LIBS) \
+	$(BLKID_LIBS) \
+	$(SECCOMP_LIBS) \
+	$(SELINUX_LIBS)
+
+ifneq ($(HAVE_LIBIPTC),)
+systemd_nspawn_LDADD += \
+	libsystemd-firewall.la
+endif # HAVE_LIBIPTC
+
+test_patch_uid_SOURCES = \
+	src/nspawn/nspawn-patch-uid.c \
+	src/nspawn/nspawn-patch-uid.h \
+	src/nspawn/test-patch-uid.c
+
+test_patch_uid_CFLAGS = \
+	$(ACL_CFLAGS)
+
+test_patch_uid_LDADD = \
+	libsystemd-shared.la \
+	$(ACL_LIBS)
+
+manual_tests += \
+	test-patch-uid
+
+include $(topsrcdir)/build-aux/Makefile.tail.mk
diff --git a/src/systemd-nspawn/nspawn-cgroup.c b/src/systemd-nspawn/nspawn-cgroup.c
new file mode 100644
index 0000000000..9e793d85f1
--- /dev/null
+++ b/src/systemd-nspawn/nspawn-cgroup.c
@@ -0,0 +1,185 @@
+/***
+  This file is part of systemd.
+
+  Copyright 2015 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <sys/mount.h>
+
+#include "systemd-basic/alloc-util.h"
+#include "systemd-basic/fd-util.h"
+#include "systemd-basic/fileio.h"
+#include "systemd-basic/mkdir.h"
+#include "systemd-basic/mount-util.h"
+#include "systemd-basic/rm-rf.h"
+#include "systemd-basic/string-util.h"
+#include "systemd-basic/strv.h"
+#include "systemd-basic/util.h"
+
+#include "nspawn-cgroup.h"
+
+static int chown_cgroup_path(const char *path, uid_t uid_shift) {
+        _cleanup_close_ int fd = -1;
+        const char *fn;
+
+        fd = open(path, O_RDONLY|O_CLOEXEC|O_DIRECTORY);
+        if (fd < 0)
+                return -errno;
+
+        FOREACH_STRING(fn,
+                       ".",
+                       "tasks",
+                       "notify_on_release",
+                       "cgroup.procs",
+                       "cgroup.events",
+                       "cgroup.clone_children",
+                       "cgroup.controllers",
+                       "cgroup.subtree_control")
+                if (fchownat(fd, fn, uid_shift, uid_shift, 0) < 0)
+                        log_full_errno(errno == ENOENT ? LOG_DEBUG :  LOG_WARNING, errno,
+                                       "Failed to chown() cgroup file %s, ignoring: %m", fn);
+
+        return 0;
+}
+
+int chown_cgroup(pid_t pid, uid_t uid_shift) {
+        _cleanup_free_ char *path = NULL, *fs = NULL;
+        int r;
+
+        r = cg_pid_get_path(NULL, pid, &path);
+        if (r < 0)
+                return log_error_errno(r, "Failed to get container cgroup path: %m");
+
+        r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, path, NULL, &fs);
+        if (r < 0)
+                return log_error_errno(r, "Failed to get file system path for container cgroup: %m");
+
+        r = chown_cgroup_path(fs, uid_shift);
+        if (r < 0)
+                return log_error_errno(r, "Failed to chown() cgroup %s: %m", fs);
+
+        return 0;
+}
+
+int sync_cgroup(pid_t pid, CGroupUnified unified_requested, uid_t arg_uid_shift) {
+        _cleanup_free_ char *cgroup = NULL;
+        char tree[] = "/tmp/unifiedXXXXXX", pid_string[DECIMAL_STR_MAX(pid) + 1];
+        bool undo_mount = false;
+        const char *fn;
+        int unified, r;
+
+        unified = cg_unified(SYSTEMD_CGROUP_CONTROLLER);
+        if (unified < 0)
+                return log_error_errno(unified, "Failed to determine whether the unified hierarchy is used: %m");
+
+        if ((unified > 0) == (unified_requested >= CGROUP_UNIFIED_SYSTEMD))
+                return 0;
+
+        /* When the host uses the legacy cgroup setup, but the
+         * container shall use the unified hierarchy, let's make sure
+         * we copy the path from the name=systemd hierarchy into the
+         * unified hierarchy. Similar for the reverse situation. */
+
+        r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, pid, &cgroup);
+        if (r < 0)
+                return log_error_errno(r, "Failed to get control group of " PID_FMT ": %m", pid);
+
+        /* In order to access the unified hierarchy we need to mount it */
+        if (!mkdtemp(tree))
+                return log_error_errno(errno, "Failed to generate temporary mount point for unified hierarchy: %m");
+
+        if (unified)
+                r = mount_verbose(LOG_ERR, "cgroup", tree, "cgroup",
+                                  MS_NOSUID|MS_NOEXEC|MS_NODEV, "none,name=systemd,xattr");
+        else
+                r = mount_verbose(LOG_ERR, "cgroup", tree, "cgroup2",
+                                  MS_NOSUID|MS_NOEXEC|MS_NODEV, NULL);
+        if (r < 0)
+                goto finish;
+
+        undo_mount = true;
+
+        /* If nspawn dies abruptly the cgroup hierarchy created below
+         * its unit isn't cleaned up. So, let's remove it
+         * https://github.com/systemd/systemd/pull/4223#issuecomment-252519810 */
+        fn = strjoina(tree, cgroup);
+        (void) rm_rf(fn, REMOVE_ROOT|REMOVE_ONLY_DIRECTORIES);
+
+        fn = strjoina(tree, cgroup, "/cgroup.procs");
+        (void) mkdir_parents(fn, 0755);
+
+        sprintf(pid_string, PID_FMT, pid);
+        r = write_string_file(fn, pid_string, 0);
+        if (r < 0) {
+                log_error_errno(r, "Failed to move process: %m");
+                goto finish;
+        }
+
+        fn = strjoina(tree, cgroup);
+        r = chown_cgroup_path(fn, arg_uid_shift);
+        if (r < 0)
+                log_error_errno(r, "Failed to chown() cgroup %s: %m", fn);
+finish:
+        if (undo_mount)
+                (void) umount_verbose(tree);
+
+        (void) rmdir(tree);
+        return r;
+}
+
+int create_subcgroup(pid_t pid, CGroupUnified unified_requested) {
+        _cleanup_free_ char *cgroup = NULL;
+        const char *child;
+        int unified, r;
+        CGroupMask supported;
+
+        /* In the unified hierarchy inner nodes may only contain
+         * subgroups, but not processes. Hence, if we running in the
+         * unified hierarchy and the container does the same, and we
+         * did not create a scope unit for the container move us and
+         * the container into two separate subcgroups. */
+
+        if (unified_requested == CGROUP_UNIFIED_NONE)
+                return 0;
+
+        unified = cg_unified(SYSTEMD_CGROUP_CONTROLLER);
+        if (unified < 0)
+                return log_error_errno(unified, "Failed to determine whether the unified hierarchy is used: %m");
+        if (unified == 0)
+                return 0;
+
+        r = cg_mask_supported(&supported);
+        if (r < 0)
+                return log_error_errno(r, "Failed to determine supported controllers: %m");
+
+        r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, 0, &cgroup);
+        if (r < 0)
+                return log_error_errno(r, "Failed to get our control group: %m");
+
+        child = strjoina(cgroup, "/payload");
+        r = cg_create_and_attach(SYSTEMD_CGROUP_CONTROLLER, child, pid);
+        if (r < 0)
+                return log_error_errno(r, "Failed to create %s subcgroup: %m", child);
+
+        child = strjoina(cgroup, "/supervisor");
+        r = cg_create_and_attach(SYSTEMD_CGROUP_CONTROLLER, child, 0);
+        if (r < 0)
+                return log_error_errno(r, "Failed to create %s subcgroup: %m", child);
+
+        /* Try to enable as many controllers as possible for the new payload. */
+        (void) cg_enable_everywhere(supported, supported, cgroup);
+        return 0;
+}
diff --git a/src/systemd-nspawn/nspawn-cgroup.h b/src/systemd-nspawn/nspawn-cgroup.h
new file mode 100644
index 0000000000..6c0ddfc7de
--- /dev/null
+++ b/src/systemd-nspawn/nspawn-cgroup.h
@@ -0,0 +1,29 @@
+#pragma once
+
+/***
+  This file is part of systemd.
+
+  Copyright 2015 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <stdbool.h>
+#include <sys/types.h>
+
+#include "systemd-basic/cgroup-util.h"
+
+int chown_cgroup(pid_t pid, uid_t uid_shift);
+int sync_cgroup(pid_t pid, CGroupUnified unified_requested, uid_t uid_shift);
+int create_subcgroup(pid_t pid, CGroupUnified unified_requested);
diff --git a/src/systemd-nspawn/nspawn-expose-ports.c b/src/systemd-nspawn/nspawn-expose-ports.c
new file mode 100644
index 0000000000..1ecebe8e30
--- /dev/null
+++ b/src/systemd-nspawn/nspawn-expose-ports.c
@@ -0,0 +1,245 @@
+/***
+  This file is part of systemd.
+
+  Copyright 2015 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include "sd-netlink/local-addresses.h"
+#include "sd-netlink/netlink-util.h"
+#include "systemd-basic/alloc-util.h"
+#include "systemd-basic/fd-util.h"
+#include "systemd-basic/in-addr-util.h"
+#include "systemd-basic/parse-util.h"
+#include "systemd-basic/socket-util.h"
+#include "systemd-basic/string-util.h"
+#include "systemd-basic/util.h"
+#include "systemd-firewall/firewall-util.h"
+#include "systemd-staging/sd-netlink.h"
+
+#include "nspawn-expose-ports.h"
+
+int expose_port_parse(ExposePort **l, const char *s) {
+
+        const char *split, *e;
+        uint16_t container_port, host_port;
+        int protocol;
+        ExposePort *p;
+        int r;
+
+        assert(l);
+        assert(s);
+
+        if ((e = startswith(s, "tcp:")))
+                protocol = IPPROTO_TCP;
+        else if ((e = startswith(s, "udp:")))
+                protocol = IPPROTO_UDP;
+        else {
+                e = s;
+                protocol = IPPROTO_TCP;
+        }
+
+        split = strchr(e, ':');
+        if (split) {
+                char v[split - e + 1];
+
+                memcpy(v, e, split - e);
+                v[split - e] = 0;
+
+                r = safe_atou16(v, &host_port);
+                if (r < 0 || host_port <= 0)
+                        return -EINVAL;
+
+                r = safe_atou16(split + 1, &container_port);
+        } else {
+                r = safe_atou16(e, &container_port);
+                host_port = container_port;
+        }
+
+        if (r < 0 || container_port <= 0)
+                return -EINVAL;
+
+        LIST_FOREACH(ports, p, *l)
+                if (p->protocol == protocol && p->host_port == host_port)
+                        return -EEXIST;
+
+        p = new(ExposePort, 1);
+        if (!p)
+                return -ENOMEM;
+
+        p->protocol = protocol;
+        p->host_port = host_port;
+        p->container_port = container_port;
+
+        LIST_PREPEND(ports, *l, p);
+
+        return 0;
+}
+
+void expose_port_free_all(ExposePort *p) {
+
+        while (p) {
+                ExposePort *q = p;
+                LIST_REMOVE(ports, p, q);
+                free(q);
+        }
+}
+
+int expose_port_flush(ExposePort* l, union in_addr_union *exposed) {
+        ExposePort *p;
+        int r, af = AF_INET;
+
+        assert(exposed);
+
+        if (!l)
+                return 0;
+
+        if (in_addr_is_null(af, exposed))
+                return 0;
+
+        log_debug("Lost IP address.");
+
+        LIST_FOREACH(ports, p, l) {
+                r = fw_add_local_dnat(false,
+                                      af,
+                                      p->protocol,
+                                      NULL,
+                                      NULL, 0,
+                                      NULL, 0,
+                                      p->host_port,
+                                      exposed,
+                                      p->container_port,
+                                      NULL);
+                if (r < 0)
+                        log_warning_errno(r, "Failed to modify firewall: %m");
+        }
+
+        *exposed = IN_ADDR_NULL;
+        return 0;
+}
+
+int expose_port_execute(sd_netlink *rtnl, ExposePort *l, union in_addr_union *exposed) {
+        _cleanup_free_ struct local_address *addresses = NULL;
+        _cleanup_free_ char *pretty = NULL;
+        union in_addr_union new_exposed;
+        ExposePort *p;
+        bool add;
+        int af = AF_INET, r;
+
+        assert(exposed);
+
+        /* Invoked each time an address is added or removed inside the
+         * container */
+
+        if (!l)
+                return 0;
+
+        r = local_addresses(rtnl, 0, af, &addresses);
+        if (r < 0)
+                return log_error_errno(r, "Failed to enumerate local addresses: %m");
+
+        add = r > 0 &&
+                addresses[0].family == af &&
+                addresses[0].scope < RT_SCOPE_LINK;
+
+        if (!add)
+                return expose_port_flush(l, exposed);
+
+        new_exposed = addresses[0].address;
+        if (in_addr_equal(af, exposed, &new_exposed))
+                return 0;
+
+        in_addr_to_string(af, &new_exposed, &pretty);
+        log_debug("New container IP is %s.", strna(pretty));
+
+        LIST_FOREACH(ports, p, l) {
+
+                r = fw_add_local_dnat(true,
+                                      af,
+                                      p->protocol,
+                                      NULL,
+                                      NULL, 0,
+                                      NULL, 0,
+                                      p->host_port,
+                                      &new_exposed,
+                                      p->container_port,
+                                      in_addr_is_null(af, exposed) ? NULL : exposed);
+                if (r < 0)
+                        log_warning_errno(r, "Failed to modify firewall: %m");
+        }
+
+        *exposed = new_exposed;
+        return 0;
+}
+
+int expose_port_send_rtnl(int send_fd) {
+        _cleanup_close_ int fd = -1;
+        int r;
+
+        assert(send_fd >= 0);
+
+        fd = socket(PF_NETLINK, SOCK_RAW|SOCK_CLOEXEC|SOCK_NONBLOCK, NETLINK_ROUTE);
+        if (fd < 0)
+                return log_error_errno(errno, "Failed to allocate container netlink: %m");
+
+        /* Store away the fd in the socket, so that it stays open as
+         * long as we run the child */
+        r = send_one_fd(send_fd, fd, 0);
+        if (r < 0)
+                return log_error_errno(r, "Failed to send netlink fd: %m");
+
+        return 0;
+}
+
+int expose_port_watch_rtnl(
+                sd_event *event,
+                int recv_fd,
+                sd_netlink_message_handler_t handler,
+                union in_addr_union *exposed,
+                sd_netlink **ret) {
+        _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL;
+        int fd, r;
+
+        assert(event);
+        assert(recv_fd >= 0);
+        assert(ret);
+
+        fd = receive_one_fd(recv_fd, 0);
+        if (fd < 0)
+                return log_error_errno(fd, "Failed to recv netlink fd: %m");
+
+        r = sd_netlink_open_fd(&rtnl, fd);
+        if (r < 0) {
+                safe_close(fd);
+                return log_error_errno(r, "Failed to create rtnl object: %m");
+        }
+
+        r = sd_netlink_add_match(rtnl, RTM_NEWADDR, handler, exposed);
+        if (r < 0)
+                return log_error_errno(r, "Failed to subscribe to RTM_NEWADDR messages: %m");
+
+        r = sd_netlink_add_match(rtnl, RTM_DELADDR, handler, exposed);
+        if (r < 0)
+                return log_error_errno(r, "Failed to subscribe to RTM_DELADDR messages: %m");
+
+        r = sd_netlink_attach_event(rtnl, event, 0);
+        if (r < 0)
+                return log_error_errno(r, "Failed to add to even loop: %m");
+
+        *ret = rtnl;
+        rtnl = NULL;
+
+        return 0;
+}
diff --git a/src/systemd-nspawn/nspawn-expose-ports.h b/src/systemd-nspawn/nspawn-expose-ports.h
new file mode 100644
index 0000000000..61134fcba6
--- /dev/null
+++ b/src/systemd-nspawn/nspawn-expose-ports.h
@@ -0,0 +1,44 @@
+#pragma once
+
+/***
+  This file is part of systemd.
+
+  Copyright 2015 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <inttypes.h>
+
+#include <systemd/sd-event.h>
+
+#include "systemd-basic/in-addr-util.h"
+#include "systemd-basic/list.h"
+#include "systemd-staging/sd-netlink.h"
+
+typedef struct ExposePort {
+        int protocol;
+        uint16_t host_port;
+        uint16_t container_port;
+        LIST_FIELDS(struct ExposePort, ports);
+} ExposePort;
+
+void expose_port_free_all(ExposePort *p);
+int expose_port_parse(ExposePort **l, const char *s);
+
+int expose_port_watch_rtnl(sd_event *event, int recv_fd, sd_netlink_message_handler_t handler, union in_addr_union *exposed, sd_netlink **ret);
+int expose_port_send_rtnl(int send_fd);
+
+int expose_port_execute(sd_netlink *rtnl, ExposePort *l, union in_addr_union *exposed);
+int expose_port_flush(ExposePort* l, union in_addr_union *exposed);
diff --git a/src/systemd-nspawn/nspawn-gperf.gperf b/src/systemd-nspawn/nspawn-gperf.gperf
new file mode 100644
index 0000000000..0c1dd98ff6
--- /dev/null
+++ b/src/systemd-nspawn/nspawn-gperf.gperf
@@ -0,0 +1,47 @@
+%{
+#include <stddef.h>
+
+#include "systemd-shared/conf-parser.h"
+
+#include "nspawn-expose-ports.h"
+#include "nspawn-settings.h"
+%}
+struct ConfigPerfItem;
+%null_strings
+%language=ANSI-C
+%define slot-name section_and_lvalue
+%define hash-function-name nspawn_gperf_hash
+%define lookup-function-name nspawn_gperf_lookup
+%readonly-tables
+%omit-struct-type
+%struct-type
+%includes
+%%
+Exec.Boot,                    config_parse_boot,          0, 0
+Exec.ProcessTwo,              config_parse_pid2,          0, 0
+Exec.Parameters,              config_parse_strv,          0, offsetof(Settings, parameters)
+Exec.Environment,             config_parse_strv,          0, offsetof(Settings, environment)
+Exec.User,                    config_parse_string,        0, offsetof(Settings, user)
+Exec.Capability,              config_parse_capability,    0, offsetof(Settings, capability)
+Exec.DropCapability,          config_parse_capability,    0, offsetof(Settings, drop_capability)
+Exec.KillSignal,              config_parse_signal,        0, offsetof(Settings, kill_signal)
+Exec.Personality,             config_parse_personality,   0, offsetof(Settings, personality)
+Exec.MachineID,               config_parse_id128,         0, offsetof(Settings, machine_id)
+Exec.WorkingDirectory,        config_parse_path,          0, offsetof(Settings, working_directory)
+Exec.PrivateUsers,            config_parse_private_users, 0, 0
+Exec.NotifyReady,             config_parse_bool,          0, offsetof(Settings, notify_ready)
+Files.ReadOnly,               config_parse_tristate,      0, offsetof(Settings, read_only)
+Files.Volatile,               config_parse_volatile_mode, 0, offsetof(Settings, volatile_mode)
+Files.Bind,                   config_parse_bind,          0, 0
+Files.BindReadOnly,           config_parse_bind,          1, 0
+Files.TemporaryFileSystem,    config_parse_tmpfs,         0, 0
+Files.PrivateUsersChown,      config_parse_tristate,      0, offsetof(Settings, userns_chown)
+Network.Private,              config_parse_tristate,      0, offsetof(Settings, private_network)
+Network.Interface,            config_parse_strv,          0, offsetof(Settings, network_interfaces)
+Network.MACVLAN,              config_parse_strv,          0, offsetof(Settings, network_macvlan)
+Network.IPVLAN,               config_parse_strv,          0, offsetof(Settings, network_ipvlan)
+Network.VirtualEthernet,      config_parse_tristate,      0, offsetof(Settings, network_veth)
+Network.VirtualEthernetExtra, config_parse_veth_extra,    0, 0
+Network.Bridge,               config_parse_ifname,        0, offsetof(Settings, network_bridge)
+Network.Zone,                 config_parse_network_zone,  0, 0
+Network.Port,                 config_parse_expose_port,   0, 0
diff --git a/src/systemd-nspawn/nspawn-mount.c b/src/systemd-nspawn/nspawn-mount.c
new file mode 100644
index 0000000000..aac04efd4b
--- /dev/null
+++ b/src/systemd-nspawn/nspawn-mount.c
@@ -0,0 +1,1164 @@
+/***
+  This file is part of systemd.
+
+  Copyright 2015 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <sys/mount.h>
+
+#include <linux/magic.h>
+
+#include "systemd-basic/alloc-util.h"
+#include "systemd-basic/escape.h"
+#include "systemd-basic/fd-util.h"
+#include "systemd-basic/fileio.h"
+#include "systemd-basic/fs-util.h"
+#include "systemd-basic/label.h"
+#include "systemd-basic/mkdir.h"
+#include "systemd-basic/mount-util.h"
+#include "systemd-basic/parse-util.h"
+#include "systemd-basic/path-util.h"
+#include "systemd-basic/rm-rf.h"
+#include "systemd-basic/set.h"
+#include "systemd-basic/stat-util.h"
+#include "systemd-basic/string-util.h"
+#include "systemd-basic/strv.h"
+#include "systemd-basic/user-util.h"
+#include "systemd-basic/util.h"
+
+#include "nspawn-mount.h"
+
+CustomMount* custom_mount_add(CustomMount **l, unsigned *n, CustomMountType t) {
+        CustomMount *c, *ret;
+
+        assert(l);
+        assert(n);
+        assert(t >= 0);
+        assert(t < _CUSTOM_MOUNT_TYPE_MAX);
+
+        c = realloc(*l, (*n + 1) * sizeof(CustomMount));
+        if (!c)
+                return NULL;
+
+        *l = c;
+        ret = *l + *n;
+        (*n)++;
+
+        *ret = (CustomMount) { .type = t };
+
+        return ret;
+}
+
+void custom_mount_free_all(CustomMount *l, unsigned n) {
+        unsigned i;
+
+        for (i = 0; i < n; i++) {
+                CustomMount *m = l + i;
+
+                free(m->source);
+                free(m->destination);
+                free(m->options);
+
+                if (m->work_dir) {
+                        (void) rm_rf(m->work_dir, REMOVE_ROOT|REMOVE_PHYSICAL);
+                        free(m->work_dir);
+                }
+
+                strv_free(m->lower);
+        }
+
+        free(l);
+}
+
+int custom_mount_compare(const void *a, const void *b) {
+        const CustomMount *x = a, *y = b;
+        int r;
+
+        r = path_compare(x->destination, y->destination);
+        if (r != 0)
+                return r;
+
+        if (x->type < y->type)
+                return -1;
+        if (x->type > y->type)
+                return 1;
+
+        return 0;
+}
+
+int bind_mount_parse(CustomMount **l, unsigned *n, const char *s, bool read_only) {
+        _cleanup_free_ char *source = NULL, *destination = NULL, *opts = NULL;
+        const char *p = s;
+        CustomMount *m;
+        int r;
+
+        assert(l);
+        assert(n);
+
+        r = extract_many_words(&p, ":", EXTRACT_DONT_COALESCE_SEPARATORS, &source, &destination, NULL);
+        if (r < 0)
+                return r;
+        if (r == 0)
+                return -EINVAL;
+
+        if (r == 1) {
+                destination = strdup(source);
+                if (!destination)
+                        return -ENOMEM;
+        }
+
+        if (r == 2 && !isempty(p)) {
+                opts = strdup(p);
+                if (!opts)
+                        return -ENOMEM;
+        }
+
+        if (!path_is_absolute(source))
+                return -EINVAL;
+
+        if (!path_is_absolute(destination))
+                return -EINVAL;
+
+        m = custom_mount_add(l, n, CUSTOM_MOUNT_BIND);
+        if (!m)
+                return log_oom();
+
+        m->source = source;
+        m->destination = destination;
+        m->read_only = read_only;
+        m->options = opts;
+
+        source = destination = opts = NULL;
+        return 0;
+}
+
+int tmpfs_mount_parse(CustomMount **l, unsigned *n, const char *s) {
+        _cleanup_free_ char *path = NULL, *opts = NULL;
+        const char *p = s;
+        CustomMount *m;
+        int r;
+
+        assert(l);
+        assert(n);
+        assert(s);
+
+        r = extract_first_word(&p, &path, ":", EXTRACT_DONT_COALESCE_SEPARATORS);
+        if (r < 0)
+                return r;
+        if (r == 0)
+                return -EINVAL;
+
+        if (isempty(p))
+                opts = strdup("mode=0755");
+        else
+                opts = strdup(p);
+        if (!opts)
+                return -ENOMEM;
+
+        if (!path_is_absolute(path))
+                return -EINVAL;
+
+        m = custom_mount_add(l, n, CUSTOM_MOUNT_TMPFS);
+        if (!m)
+                return -ENOMEM;
+
+        m->destination = path;
+        m->options = opts;
+
+        path = opts = NULL;
+        return 0;
+}
+
+static int tmpfs_patch_options(
+                const char *options,
+                bool userns,
+                uid_t uid_shift, uid_t uid_range,
+                bool patch_ids,
+                const char *selinux_apifs_context,
+                char **ret) {
+
+        char *buf = NULL;
+
+        if ((userns && uid_shift != 0) || patch_ids) {
+                assert(uid_shift != UID_INVALID);
+
+                if (options)
+                        (void) asprintf(&buf, "%s,uid=" UID_FMT ",gid=" UID_FMT, options, uid_shift, uid_shift);
+                else
+                        (void) asprintf(&buf, "uid=" UID_FMT ",gid=" UID_FMT, uid_shift, uid_shift);
+                if (!buf)
+                        return -ENOMEM;
+
+                options = buf;
+        }
+
+#ifdef HAVE_SELINUX
+        if (selinux_apifs_context) {
+                char *t;
+
+                if (options)
+                        t = strjoin(options, ",context=\"", selinux_apifs_context, "\"", NULL);
+                else
+                        t = strjoin("context=\"", selinux_apifs_context, "\"", NULL);
+                if (!t) {
+                        free(buf);
+                        return -ENOMEM;
+                }
+
+                free(buf);
+                buf = t;
+        }
+#endif
+
+        if (!buf && options) {
+                buf = strdup(options);
+                if (!buf)
+                        return -ENOMEM;
+        }
+        *ret = buf;
+
+        return !!buf;
+}
+
+int mount_sysfs(const char *dest) {
+        const char *full, *top, *x;
+        int r;
+
+        top = prefix_roota(dest, "/sys");
+        r = path_check_fstype(top, SYSFS_MAGIC);
+        if (r < 0)
+                return log_error_errno(r, "Failed to determine filesystem type of %s: %m", top);
+        /* /sys might already be mounted as sysfs by the outer child in the
+         * !netns case. In this case, it's all good. Don't touch it because we
+         * don't have the right to do so, see https://github.com/systemd/systemd/issues/1555.
+         */
+        if (r > 0)
+                return 0;
+
+        full = prefix_roota(top, "/full");
+
+        (void) mkdir(full, 0755);
+
+        r = mount_verbose(LOG_ERR, "sysfs", full, "sysfs",
+                          MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV, NULL);
+        if (r < 0)
+                return r;
+
+        FOREACH_STRING(x, "block", "bus", "class", "dev", "devices", "kernel") {
+                _cleanup_free_ char *from = NULL, *to = NULL;
+
+                from = prefix_root(full, x);
+                if (!from)
+                        return log_oom();
+
+                to = prefix_root(top, x);
+                if (!to)
+                        return log_oom();
+
+                (void) mkdir(to, 0755);
+
+                r = mount_verbose(LOG_ERR, from, to, NULL, MS_BIND, NULL);
+                if (r < 0)
+                        return r;
+
+                r = mount_verbose(LOG_ERR, NULL, to, NULL,
+                                  MS_BIND|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT, NULL);
+                if (r < 0)
+                        return r;
+        }
+
+        r = umount_verbose(full);
+        if (r < 0)
+                return r;
+
+        if (rmdir(full) < 0)
+                return log_error_errno(errno, "Failed to remove %s: %m", full);
+
+        x = prefix_roota(top, "/fs/kdbus");
+        (void) mkdir_p(x, 0755);
+
+        /* Create mountpoint for cgroups. Otherwise we are not allowed since we
+         * remount /sys read-only.
+         */
+        if (cg_ns_supported()) {
+                x = prefix_roota(top, "/fs/cgroup");
+                (void) mkdir_p(x, 0755);
+        }
+
+        return mount_verbose(LOG_ERR, NULL, top, NULL,
+                             MS_BIND|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT, NULL);
+}
+
+static int mkdir_userns(const char *path, mode_t mode, bool in_userns, uid_t uid_shift) {
+        int r;
+
+        assert(path);
+
+        r = mkdir(path, mode);
+        if (r < 0 && errno != EEXIST)
+                return -errno;
+
+        if (!in_userns) {
+                r = lchown(path, uid_shift, uid_shift);
+                if (r < 0)
+                        return -errno;
+        }
+
+        return 0;
+}
+
+static int mkdir_userns_p(const char *prefix, const char *path, mode_t mode, bool in_userns, uid_t uid_shift) {
+        const char *p, *e;
+        int r;
+
+        assert(path);
+
+        if (prefix && !path_startswith(path, prefix))
+                return -ENOTDIR;
+
+        /* create every parent directory in the path, except the last component */
+        p = path + strspn(path, "/");
+        for (;;) {
+                char t[strlen(path) + 1];
+
+                e = p + strcspn(p, "/");
+                p = e + strspn(e, "/");
+
+                /* Is this the last component? If so, then we're done */
+                if (*p == 0)
+                        break;
+
+                memcpy(t, path, e - path);
+                t[e-path] = 0;
+
+                if (prefix && path_startswith(prefix, t))
+                        continue;
+
+                r = mkdir_userns(t, mode, in_userns, uid_shift);
+                if (r < 0)
+                        return r;
+        }
+
+        return mkdir_userns(path, mode, in_userns, uid_shift);
+}
+
+int mount_all(const char *dest,
+              bool use_userns, bool in_userns,
+              bool use_netns,
+              uid_t uid_shift, uid_t uid_range,
+              const char *selinux_apifs_context) {
+
+        typedef struct MountPoint {
+                const char *what;
+                const char *where;
+                const char *type;
+                const char *options;
+                unsigned long flags;
+                bool fatal;
+                bool in_userns;
+                bool use_netns;
+        } MountPoint;
+
+        static const MountPoint mount_table[] = {
+                { "proc",                "/proc",               "proc",  NULL,        MS_NOSUID|MS_NOEXEC|MS_NODEV,                              true,  true,  false },
+                { "/proc/sys",           "/proc/sys",           NULL,    NULL,        MS_BIND,                                                   true,  true,  false },   /* Bind mount first ...*/
+                { "/proc/sys/net",       "/proc/sys/net",       NULL,    NULL,        MS_BIND,                                                   true,  true,  true  },   /* (except for this) */
+                { NULL,                  "/proc/sys",           NULL,    NULL,        MS_BIND|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT, true,  true,  false },   /* ... then, make it r/o */
+                { "/proc/sysrq-trigger", "/proc/sysrq-trigger", NULL,    NULL,        MS_BIND,                                                   false, true,  false },   /* Bind mount first ...*/
+                { NULL,                  "/proc/sysrq-trigger", NULL,    NULL,        MS_BIND|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT, false, true,  false },   /* ... then, make it r/o */
+                { "tmpfs",               "/sys",                "tmpfs", "mode=755",  MS_NOSUID|MS_NOEXEC|MS_NODEV,                              true,  false, true  },
+                { "sysfs",               "/sys",                "sysfs", NULL,        MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV,                    true,  false, false },
+                { "tmpfs",               "/dev",                "tmpfs", "mode=755",  MS_NOSUID|MS_STRICTATIME,                                  true,  false, false },
+                { "tmpfs",               "/dev/shm",            "tmpfs", "mode=1777", MS_NOSUID|MS_NODEV|MS_STRICTATIME,                         true,  false, false },
+                { "tmpfs",               "/run",                "tmpfs", "mode=755",  MS_NOSUID|MS_NODEV|MS_STRICTATIME,                         true,  false, false },
+                { "tmpfs",               "/tmp",                "tmpfs", "mode=1777", MS_STRICTATIME,                                            true,  false,  false },
+#ifdef HAVE_SELINUX
+                { "/sys/fs/selinux",     "/sys/fs/selinux",     NULL,     NULL,       MS_BIND,                                                   false, false, false },  /* Bind mount first */
+                { NULL,                  "/sys/fs/selinux",     NULL,     NULL,       MS_BIND|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT, false, false, false },  /* Then, make it r/o */
+#endif
+        };
+
+        unsigned k;
+        int r;
+
+        for (k = 0; k < ELEMENTSOF(mount_table); k++) {
+                _cleanup_free_ char *where = NULL, *options = NULL;
+                const char *o;
+
+                if (in_userns != mount_table[k].in_userns)
+                        continue;
+
+                if (!use_netns && mount_table[k].use_netns)
+                        continue;
+
+                where = prefix_root(dest, mount_table[k].where);
+                if (!where)
+                        return log_oom();
+
+                r = path_is_mount_point(where, AT_SYMLINK_FOLLOW);
+                if (r < 0 && r != -ENOENT)
+                        return log_error_errno(r, "Failed to detect whether %s is a mount point: %m", where);
+
+                /* Skip this entry if it is not a remount. */
+                if (mount_table[k].what && r > 0)
+                        continue;
+
+                r = mkdir_userns_p(dest, where, 0755, in_userns, uid_shift);
+                if (r < 0 && r != -EEXIST) {
+                        if (mount_table[k].fatal)
+                                return log_error_errno(r, "Failed to create directory %s: %m", where);
+
+                        log_debug_errno(r, "Failed to create directory %s: %m", where);
+                        continue;
+                }
+
+                o = mount_table[k].options;
+                if (streq_ptr(mount_table[k].type, "tmpfs")) {
+                        if (in_userns)
+                                r = tmpfs_patch_options(o, use_userns, 0, uid_range, true, selinux_apifs_context, &options);
+                        else
+                                r = tmpfs_patch_options(o, use_userns, uid_shift, uid_range, false, selinux_apifs_context, &options);
+                        if (r < 0)
+                                return log_oom();
+                        if (r > 0)
+                                o = options;
+                }
+
+                r = mount_verbose(mount_table[k].fatal ? LOG_ERR : LOG_WARNING,
+                                  mount_table[k].what,
+                                  where,
+                                  mount_table[k].type,
+                                  mount_table[k].flags,
+                                  o);
+                if (r < 0 && mount_table[k].fatal)
+                        return r;
+        }
+
+        return 0;
+}
+
+static int parse_mount_bind_options(const char *options, unsigned long *mount_flags, char **mount_opts) {
+        const char *p = options;
+        unsigned long flags = *mount_flags;
+        char *opts = NULL;
+
+        assert(options);
+
+        for (;;) {
+                _cleanup_free_ char *word = NULL;
+                int r = extract_first_word(&p, &word, ",", 0);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to extract mount option: %m");
+                if (r == 0)
+                        break;
+
+                if (streq(word, "rbind"))
+                        flags |= MS_REC;
+                else if (streq(word, "norbind"))
+                        flags &= ~MS_REC;
+                else {
+                        log_error("Invalid bind mount option: %s", word);
+                        return -EINVAL;
+                }
+        }
+
+        *mount_flags = flags;
+        /* in the future mount_opts will hold string options for mount(2) */
+        *mount_opts = opts;
+
+        return 0;
+}
+
+static int mount_bind(const char *dest, CustomMount *m) {
+        struct stat source_st, dest_st;
+        const char *where;
+        unsigned long mount_flags = MS_BIND | MS_REC;
+        _cleanup_free_ char *mount_opts = NULL;
+        int r;
+
+        assert(m);
+
+        if (m->options) {
+                r = parse_mount_bind_options(m->options, &mount_flags, &mount_opts);
+                if (r < 0)
+                        return r;
+        }
+
+        if (stat(m->source, &source_st) < 0)
+                return log_error_errno(errno, "Failed to stat %s: %m", m->source);
+
+        where = prefix_roota(dest, m->destination);
+
+        if (stat(where, &dest_st) >= 0) {
+                if (S_ISDIR(source_st.st_mode) && !S_ISDIR(dest_st.st_mode)) {
+                        log_error("Cannot bind mount directory %s on file %s.", m->source, where);
+                        return -EINVAL;
+                }
+
+                if (!S_ISDIR(source_st.st_mode) && S_ISDIR(dest_st.st_mode)) {
+                        log_error("Cannot bind mount file %s on directory %s.", m->source, where);
+                        return -EINVAL;
+                }
+
+        } else if (errno == ENOENT) {
+                r = mkdir_parents_label(where, 0755);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to make parents of %s: %m", where);
+
+                /* Create the mount point. Any non-directory file can be
+                * mounted on any non-directory file (regular, fifo, socket,
+                * char, block).
+                */
+                if (S_ISDIR(source_st.st_mode))
+                        r = mkdir_label(where, 0755);
+                else
+                        r = touch(where);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to create mount point %s: %m", where);
+
+        } else
+                return log_error_errno(errno, "Failed to stat %s: %m", where);
+
+        r = mount_verbose(LOG_ERR, m->source, where, NULL, mount_flags, mount_opts);
+        if (r < 0)
+                return r;
+
+        if (m->read_only) {
+                r = bind_remount_recursive(where, true, NULL);
+                if (r < 0)
+                        return log_error_errno(r, "Read-only bind mount failed: %m");
+        }
+
+        return 0;
+}
+
+static int mount_tmpfs(
+                const char *dest,
+                CustomMount *m,
+                bool userns, uid_t uid_shift, uid_t uid_range,
+                const char *selinux_apifs_context) {
+
+        const char *where, *options;
+        _cleanup_free_ char *buf = NULL;
+        int r;
+
+        assert(dest);
+        assert(m);
+
+        where = prefix_roota(dest, m->destination);
+
+        r = mkdir_p_label(where, 0755);
+        if (r < 0 && r != -EEXIST)
+                return log_error_errno(r, "Creating mount point for tmpfs %s failed: %m", where);
+
+        r = tmpfs_patch_options(m->options, userns, uid_shift, uid_range, false, selinux_apifs_context, &buf);
+        if (r < 0)
+                return log_oom();
+        options = r > 0 ? buf : m->options;
+
+        return mount_verbose(LOG_ERR, "tmpfs", where, "tmpfs", MS_NODEV|MS_STRICTATIME, options);
+}
+
+static char *joined_and_escaped_lower_dirs(char * const *lower) {
+        _cleanup_strv_free_ char **sv = NULL;
+
+        sv = strv_copy(lower);
+        if (!sv)
+                return NULL;
+
+        strv_reverse(sv);
+
+        if (!strv_shell_escape(sv, ",:"))
+                return NULL;
+
+        return strv_join(sv, ":");
+}
+
+static int mount_overlay(const char *dest, CustomMount *m) {
+        _cleanup_free_ char *lower = NULL;
+        const char *where, *options;
+        int r;
+
+        assert(dest);
+        assert(m);
+
+        where = prefix_roota(dest, m->destination);
+
+        r = mkdir_label(where, 0755);
+        if (r < 0 && r != -EEXIST)
+                return log_error_errno(r, "Creating mount point for overlay %s failed: %m", where);
+
+        (void) mkdir_p_label(m->source, 0755);
+
+        lower = joined_and_escaped_lower_dirs(m->lower);
+        if (!lower)
+                return log_oom();
+
+        if (m->read_only) {
+                _cleanup_free_ char *escaped_source = NULL;
+
+                escaped_source = shell_escape(m->source, ",:");
+                if (!escaped_source)
+                        return log_oom();
+
+                options = strjoina("lowerdir=", escaped_source, ":", lower);
+        } else {
+                _cleanup_free_ char *escaped_source = NULL, *escaped_work_dir = NULL;
+
+                assert(m->work_dir);
+                (void) mkdir_label(m->work_dir, 0700);
+
+                escaped_source = shell_escape(m->source, ",:");
+                if (!escaped_source)
+                        return log_oom();
+                escaped_work_dir = shell_escape(m->work_dir, ",:");
+                if (!escaped_work_dir)
+                        return log_oom();
+
+                options = strjoina("lowerdir=", lower, ",upperdir=", escaped_source, ",workdir=", escaped_work_dir);
+        }
+
+        return mount_verbose(LOG_ERR, "overlay", where, "overlay", m->read_only ? MS_RDONLY : 0, options);
+}
+
+int mount_custom(
+                const char *dest,
+                CustomMount *mounts, unsigned n,
+                bool userns, uid_t uid_shift, uid_t uid_range,
+                const char *selinux_apifs_context) {
+
+        unsigned i;
+        int r;
+
+        assert(dest);
+
+        for (i = 0; i < n; i++) {
+                CustomMount *m = mounts + i;
+
+                switch (m->type) {
+
+                case CUSTOM_MOUNT_BIND:
+                        r = mount_bind(dest, m);
+                        break;
+
+                case CUSTOM_MOUNT_TMPFS:
+                        r = mount_tmpfs(dest, m, userns, uid_shift, uid_range, selinux_apifs_context);
+                        break;
+
+                case CUSTOM_MOUNT_OVERLAY:
+                        r = mount_overlay(dest, m);
+                        break;
+
+                default:
+                        assert_not_reached("Unknown custom mount type");
+                }
+
+                if (r < 0)
+                        return r;
+        }
+
+        return 0;
+}
+
+/* Retrieve existing subsystems. This function is called in a new cgroup
+ * namespace.
+ */
+static int get_controllers(Set *subsystems) {
+        _cleanup_fclose_ FILE *f = NULL;
+        char line[LINE_MAX];
+
+        assert(subsystems);
+
+        f = fopen("/proc/self/cgroup", "re");
+        if (!f)
+                return errno == ENOENT ? -ESRCH : -errno;
+
+        FOREACH_LINE(line, f, return -errno) {
+                int r;
+                char *e, *l, *p;
+
+                l = strchr(line, ':');
+                if (!l)
+                        continue;
+
+                l++;
+                e = strchr(l, ':');
+                if (!e)
+                        continue;
+
+                *e = 0;
+
+                if (STR_IN_SET(l, "", "name=systemd"))
+                        continue;
+
+                p = strdup(l);
+                if (!p)
+                        return -ENOMEM;
+
+                r = set_consume(subsystems, p);
+                if (r < 0)
+                        return r;
+        }
+
+        return 0;
+}
+
+static int mount_legacy_cgroup_hierarchy(const char *dest, const char *controller, const char *hierarchy,
+                                         CGroupUnified unified_requested, bool read_only) {
+        const char *to, *fstype, *opts;
+        int r;
+
+        to = strjoina(strempty(dest), "/sys/fs/cgroup/", hierarchy);
+
+        r = path_is_mount_point(to, 0);
+        if (r < 0 && r != -ENOENT)
+                return log_error_errno(r, "Failed to determine if %s is mounted already: %m", to);
+        if (r > 0)
+                return 0;
+
+        mkdir_p(to, 0755);
+
+        /* The superblock mount options of the mount point need to be
+         * identical to the hosts', and hence writable... */
+        if (streq(controller, SYSTEMD_CGROUP_CONTROLLER)) {
+                if (unified_requested >= CGROUP_UNIFIED_SYSTEMD) {
+                        fstype = "cgroup2";
+                        opts = NULL;
+                } else {
+                        fstype = "cgroup";
+                        opts = "none,name=systemd,xattr";
+                }
+        } else {
+                fstype = "cgroup";
+                opts = controller;
+        }
+
+        r = mount_verbose(LOG_ERR, "cgroup", to, fstype, MS_NOSUID|MS_NOEXEC|MS_NODEV, opts);
+        if (r < 0)
+                return r;
+
+        /* ... hence let's only make the bind mount read-only, not the superblock. */
+        if (read_only) {
+                r = mount_verbose(LOG_ERR, NULL, to, NULL,
+                                  MS_BIND|MS_REMOUNT|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_RDONLY, NULL);
+                if (r < 0)
+                        return r;
+        }
+
+        return 1;
+}
+
+/* Mount a legacy cgroup hierarchy when cgroup namespaces are supported. */
+static int mount_legacy_cgns_supported(
+                CGroupUnified unified_requested, bool userns, uid_t uid_shift,
+                uid_t uid_range, const char *selinux_apifs_context) {
+        _cleanup_set_free_free_ Set *controllers = NULL;
+        const char *cgroup_root = "/sys/fs/cgroup", *c;
+        int r;
+
+        (void) mkdir_p(cgroup_root, 0755);
+
+        /* Mount a tmpfs to /sys/fs/cgroup if it's not mounted there yet. */
+        r = path_is_mount_point(cgroup_root, AT_SYMLINK_FOLLOW);
+        if (r < 0)
+                return log_error_errno(r, "Failed to determine if /sys/fs/cgroup is already mounted: %m");
+        if (r == 0) {
+                _cleanup_free_ char *options = NULL;
+
+                /* When cgroup namespaces are enabled and user namespaces are
+                 * used then the mount of the cgroupfs is done *inside* the new
+                 * user namespace. We're root in the new user namespace and the
+                 * kernel will happily translate our uid/gid to the correct
+                 * uid/gid as seen from e.g. /proc/1/mountinfo. So we simply
+                 * pass uid 0 and not uid_shift to tmpfs_patch_options().
+                 */
+                r = tmpfs_patch_options("mode=755", userns, 0, uid_range, true, selinux_apifs_context, &options);
+                if (r < 0)
+                        return log_oom();
+
+                r = mount_verbose(LOG_ERR, "tmpfs", cgroup_root, "tmpfs",
+                                  MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_STRICTATIME, options);
+                if (r < 0)
+                        return r;
+        }
+
+        if (cg_all_unified() > 0)
+                goto skip_controllers;
+
+        controllers = set_new(&string_hash_ops);
+        if (!controllers)
+                return log_oom();
+
+        r = get_controllers(controllers);
+        if (r < 0)
+                return log_error_errno(r, "Failed to determine cgroup controllers: %m");
+
+        for (;;) {
+                _cleanup_free_ const char *controller = NULL;
+
+                controller = set_steal_first(controllers);
+                if (!controller)
+                        break;
+
+                r = mount_legacy_cgroup_hierarchy("", controller, controller, unified_requested, !userns);
+                if (r < 0)
+                        return r;
+
+                /* When multiple hierarchies are co-mounted, make their
+                 * constituting individual hierarchies a symlink to the
+                 * co-mount.
+                 */
+                c = controller;
+                for (;;) {
+                        _cleanup_free_ char *target = NULL, *tok = NULL;
+
+                        r = extract_first_word(&c, &tok, ",", 0);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to extract co-mounted cgroup controller: %m");
+                        if (r == 0)
+                                break;
+
+                        target = prefix_root("/sys/fs/cgroup", tok);
+                        if (!target)
+                                return log_oom();
+
+                        if (streq(controller, tok))
+                                break;
+
+                        r = symlink_idempotent(controller, target);
+                        if (r == -EINVAL)
+                                return log_error_errno(r, "Invalid existing symlink for combined hierarchy: %m");
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to create symlink for combined hierarchy: %m");
+                }
+        }
+
+skip_controllers:
+        r = mount_legacy_cgroup_hierarchy("", SYSTEMD_CGROUP_CONTROLLER, "systemd", unified_requested, false);
+        if (r < 0)
+                return r;
+
+        if (!userns)
+                return mount_verbose(LOG_ERR, NULL, cgroup_root, NULL,
+                                     MS_REMOUNT|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_STRICTATIME|MS_RDONLY, "mode=755");
+
+        return 0;
+}
+
+/* Mount legacy cgroup hierarchy when cgroup namespaces are unsupported. */
+static int mount_legacy_cgns_unsupported(
+                const char *dest,
+                CGroupUnified unified_requested, bool userns, uid_t uid_shift, uid_t uid_range,
+                const char *selinux_apifs_context) {
+        _cleanup_set_free_free_ Set *controllers = NULL;
+        const char *cgroup_root;
+        int r;
+
+        cgroup_root = prefix_roota(dest, "/sys/fs/cgroup");
+
+        (void) mkdir_p(cgroup_root, 0755);
+
+        /* Mount a tmpfs to /sys/fs/cgroup if it's not mounted there yet. */
+        r = path_is_mount_point(cgroup_root, AT_SYMLINK_FOLLOW);
+        if (r < 0)
+                return log_error_errno(r, "Failed to determine if /sys/fs/cgroup is already mounted: %m");
+        if (r == 0) {
+                _cleanup_free_ char *options = NULL;
+
+                r = tmpfs_patch_options("mode=755", userns, uid_shift, uid_range, false, selinux_apifs_context, &options);
+                if (r < 0)
+                        return log_oom();
+
+                r = mount_verbose(LOG_ERR, "tmpfs", cgroup_root, "tmpfs",
+                                  MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_STRICTATIME, options);
+                if (r < 0)
+                        return r;
+        }
+
+        if (cg_all_unified() > 0)
+                goto skip_controllers;
+
+        controllers = set_new(&string_hash_ops);
+        if (!controllers)
+                return log_oom();
+
+        r = cg_kernel_controllers(controllers);
+        if (r < 0)
+                return log_error_errno(r, "Failed to determine cgroup controllers: %m");
+
+        for (;;) {
+                _cleanup_free_ char *controller = NULL, *origin = NULL, *combined = NULL;
+
+                controller = set_steal_first(controllers);
+                if (!controller)
+                        break;
+
+                origin = prefix_root("/sys/fs/cgroup/", controller);
+                if (!origin)
+                        return log_oom();
+
+                r = readlink_malloc(origin, &combined);
+                if (r == -EINVAL) {
+                        /* Not a symbolic link, but directly a single cgroup hierarchy */
+
+                        r = mount_legacy_cgroup_hierarchy(dest, controller, controller, unified_requested, true);
+                        if (r < 0)
+                                return r;
+
+                } else if (r < 0)
+                        return log_error_errno(r, "Failed to read link %s: %m", origin);
+                else {
+                        _cleanup_free_ char *target = NULL;
+
+                        target = prefix_root(dest, origin);
+                        if (!target)
+                                return log_oom();
+
+                        /* A symbolic link, a combination of controllers in one hierarchy */
+
+                        if (!filename_is_valid(combined)) {
+                                log_warning("Ignoring invalid combined hierarchy %s.", combined);
+                                continue;
+                        }
+
+                        r = mount_legacy_cgroup_hierarchy(dest, combined, combined, unified_requested, true);
+                        if (r < 0)
+                                return r;
+
+                        r = symlink_idempotent(combined, target);
+                        if (r == -EINVAL)
+                                return log_error_errno(r, "Invalid existing symlink for combined hierarchy: %m");
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to create symlink for combined hierarchy: %m");
+                }
+        }
+
+skip_controllers:
+        r = mount_legacy_cgroup_hierarchy(dest, SYSTEMD_CGROUP_CONTROLLER, "systemd", unified_requested, false);
+        if (r < 0)
+                return r;
+
+        return mount_verbose(LOG_ERR, NULL, cgroup_root, NULL,
+                             MS_REMOUNT|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_STRICTATIME|MS_RDONLY, "mode=755");
+}
+
+static int mount_unified_cgroups(const char *dest) {
+        const char *p;
+        int r;
+
+        assert(dest);
+
+        p = prefix_roota(dest, "/sys/fs/cgroup");
+
+        (void) mkdir_p(p, 0755);
+
+        r = path_is_mount_point(p, AT_SYMLINK_FOLLOW);
+        if (r < 0)
+                return log_error_errno(r, "Failed to determine if %s is mounted already: %m", p);
+        if (r > 0) {
+                p = prefix_roota(dest, "/sys/fs/cgroup/cgroup.procs");
+                if (access(p, F_OK) >= 0)
+                        return 0;
+                if (errno != ENOENT)
+                        return log_error_errno(errno, "Failed to determine if mount point %s contains the unified cgroup hierarchy: %m", p);
+
+                log_error("%s is already mounted but not a unified cgroup hierarchy. Refusing.", p);
+                return -EINVAL;
+        }
+
+        return mount_verbose(LOG_ERR, "cgroup", p, "cgroup2", MS_NOSUID|MS_NOEXEC|MS_NODEV, NULL);
+}
+
+int mount_cgroups(
+                const char *dest,
+                CGroupUnified unified_requested,
+                bool userns, uid_t uid_shift, uid_t uid_range,
+                const char *selinux_apifs_context,
+                bool use_cgns) {
+
+        if (unified_requested >= CGROUP_UNIFIED_ALL)
+                return mount_unified_cgroups(dest);
+        else if (use_cgns)
+                return mount_legacy_cgns_supported(unified_requested, userns, uid_shift, uid_range, selinux_apifs_context);
+
+        return mount_legacy_cgns_unsupported(dest, unified_requested, userns, uid_shift, uid_range, selinux_apifs_context);
+}
+
+int mount_systemd_cgroup_writable(
+                const char *dest,
+                CGroupUnified unified_requested) {
+
+        _cleanup_free_ char *own_cgroup_path = NULL;
+        const char *systemd_root, *systemd_own;
+        int r;
+
+        assert(dest);
+
+        r = cg_pid_get_path(NULL, 0, &own_cgroup_path);
+        if (r < 0)
+                return log_error_errno(r, "Failed to determine our own cgroup path: %m");
+
+        /* If we are living in the top-level, then there's nothing to do... */
+        if (path_equal(own_cgroup_path, "/"))
+                return 0;
+
+        if (unified_requested >= CGROUP_UNIFIED_ALL) {
+                systemd_own = strjoina(dest, "/sys/fs/cgroup", own_cgroup_path);
+                systemd_root = prefix_roota(dest, "/sys/fs/cgroup");
+        } else {
+                systemd_own = strjoina(dest, "/sys/fs/cgroup/systemd", own_cgroup_path);
+                systemd_root = prefix_roota(dest, "/sys/fs/cgroup/systemd");
+        }
+
+        /* Make our own cgroup a (writable) bind mount */
+        r = mount_verbose(LOG_ERR, systemd_own, systemd_own,  NULL, MS_BIND, NULL);
+        if (r < 0)
+                return r;
+
+        /* And then remount the systemd cgroup root read-only */
+        return mount_verbose(LOG_ERR, NULL, systemd_root, NULL,
+                             MS_BIND|MS_REMOUNT|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_RDONLY, NULL);
+}
+
+int setup_volatile_state(
+                const char *directory,
+                VolatileMode mode,
+                bool userns, uid_t uid_shift, uid_t uid_range,
+                const char *selinux_apifs_context) {
+
+        _cleanup_free_ char *buf = NULL;
+        const char *p, *options;
+        int r;
+
+        assert(directory);
+
+        if (mode != VOLATILE_STATE)
+                return 0;
+
+        /* --volatile=state means we simply overmount /var
+           with a tmpfs, and the rest read-only. */
+
+        r = bind_remount_recursive(directory, true, NULL);
+        if (r < 0)
+                return log_error_errno(r, "Failed to remount %s read-only: %m", directory);
+
+        p = prefix_roota(directory, "/var");
+        r = mkdir(p, 0755);
+        if (r < 0 && errno != EEXIST)
+                return log_error_errno(errno, "Failed to create %s: %m", directory);
+
+        options = "mode=755";
+        r = tmpfs_patch_options(options, userns, uid_shift, uid_range, false, selinux_apifs_context, &buf);
+        if (r < 0)
+                return log_oom();
+        if (r > 0)
+                options = buf;
+
+        return mount_verbose(LOG_ERR, "tmpfs", p, "tmpfs", MS_STRICTATIME, options);
+}
+
+int setup_volatile(
+                const char *directory,
+                VolatileMode mode,
+                bool userns, uid_t uid_shift, uid_t uid_range,
+                const char *selinux_apifs_context) {
+
+        bool tmpfs_mounted = false, bind_mounted = false;
+        char template[] = "/tmp/nspawn-volatile-XXXXXX";
+        _cleanup_free_ char *buf = NULL;
+        const char *f, *t, *options;
+        int r;
+
+        assert(directory);
+
+        if (mode != VOLATILE_YES)
+                return 0;
+
+        /* --volatile=yes means we mount a tmpfs to the root dir, and
+           the original /usr to use inside it, and that read-only. */
+
+        if (!mkdtemp(template))
+                return log_error_errno(errno, "Failed to create temporary directory: %m");
+
+        options = "mode=755";
+        r = tmpfs_patch_options(options, userns, uid_shift, uid_range, false, selinux_apifs_context, &buf);
+        if (r < 0)
+                return log_oom();
+        if (r > 0)
+                options = buf;
+
+        r = mount_verbose(LOG_ERR, "tmpfs", template, "tmpfs", MS_STRICTATIME, options);
+        if (r < 0)
+                goto fail;
+
+        tmpfs_mounted = true;
+
+        f = prefix_roota(directory, "/usr");
+        t = prefix_roota(template, "/usr");
+
+        r = mkdir(t, 0755);
+        if (r < 0 && errno != EEXIST) {
+                r = log_error_errno(errno, "Failed to create %s: %m", t);
+                goto fail;
+        }
+
+        r = mount_verbose(LOG_ERR, f, t, NULL, MS_BIND|MS_REC, NULL);
+        if (r < 0)
+                goto fail;
+
+        bind_mounted = true;
+
+        r = bind_remount_recursive(t, true, NULL);
+        if (r < 0) {
+                log_error_errno(r, "Failed to remount %s read-only: %m", t);
+                goto fail;
+        }
+
+        r = mount_verbose(LOG_ERR, template, directory, NULL, MS_MOVE, NULL);
+        if (r < 0)
+                goto fail;
+
+        (void) rmdir(template);
+
+        return 0;
+
+fail:
+        if (bind_mounted)
+                (void) umount_verbose(t);
+
+        if (tmpfs_mounted)
+                (void) umount_verbose(template);
+        (void) rmdir(template);
+        return r;
+}
+
+VolatileMode volatile_mode_from_string(const char *s) {
+        int b;
+
+        if (isempty(s))
+                return _VOLATILE_MODE_INVALID;
+
+        b = parse_boolean(s);
+        if (b > 0)
+                return VOLATILE_YES;
+        if (b == 0)
+                return VOLATILE_NO;
+
+        if (streq(s, "state"))
+                return VOLATILE_STATE;
+
+        return _VOLATILE_MODE_INVALID;
+}
diff --git a/src/systemd-nspawn/nspawn-mount.h b/src/systemd-nspawn/nspawn-mount.h
new file mode 100644
index 0000000000..0d58439df3
--- /dev/null
+++ b/src/systemd-nspawn/nspawn-mount.h
@@ -0,0 +1,71 @@
+#pragma once
+
+/***
+  This file is part of systemd.
+
+  Copyright 2015 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <stdbool.h>
+
+#include "systemd-basic/cgroup-util.h"
+
+typedef enum VolatileMode {
+        VOLATILE_NO,
+        VOLATILE_YES,
+        VOLATILE_STATE,
+        _VOLATILE_MODE_MAX,
+        _VOLATILE_MODE_INVALID = -1
+} VolatileMode;
+
+typedef enum CustomMountType {
+        CUSTOM_MOUNT_BIND,
+        CUSTOM_MOUNT_TMPFS,
+        CUSTOM_MOUNT_OVERLAY,
+        _CUSTOM_MOUNT_TYPE_MAX,
+        _CUSTOM_MOUNT_TYPE_INVALID = -1
+} CustomMountType;
+
+typedef struct CustomMount {
+        CustomMountType type;
+        bool read_only;
+        char *source; /* for overlayfs this is the upper directory */
+        char *destination;
+        char *options;
+        char *work_dir;
+        char **lower;
+} CustomMount;
+
+CustomMount* custom_mount_add(CustomMount **l, unsigned *n, CustomMountType t);
+
+void custom_mount_free_all(CustomMount *l, unsigned n);
+int bind_mount_parse(CustomMount **l, unsigned *n, const char *s, bool read_only);
+int tmpfs_mount_parse(CustomMount **l, unsigned *n, const char *s);
+
+int custom_mount_compare(const void *a, const void *b);
+
+int mount_all(const char *dest, bool use_userns, bool in_userns, bool use_netns, uid_t uid_shift, uid_t uid_range, const char *selinux_apifs_context);
+int mount_sysfs(const char *dest);
+
+int mount_cgroups(const char *dest, CGroupUnified unified_requested, bool userns, uid_t uid_shift, uid_t uid_range, const char *selinux_apifs_context, bool use_cgns);
+int mount_systemd_cgroup_writable(const char *dest, CGroupUnified unified_requested);
+
+int mount_custom(const char *dest, CustomMount *mounts, unsigned n, bool userns, uid_t uid_shift, uid_t uid_range, const char *selinux_apifs_context);
+
+int setup_volatile(const char *directory, VolatileMode mode, bool userns, uid_t uid_shift, uid_t uid_range, const char *selinux_apifs_context);
+int setup_volatile_state(const char *directory, VolatileMode mode, bool userns, uid_t uid_shift, uid_t uid_range, const char *selinux_apifs_context);
+
+VolatileMode volatile_mode_from_string(const char *s);
diff --git a/src/systemd-nspawn/nspawn-network.c b/src/systemd-nspawn/nspawn-network.c
new file mode 100644
index 0000000000..2e0760ec86
--- /dev/null
+++ b/src/systemd-nspawn/nspawn-network.c
@@ -0,0 +1,696 @@
+/***
+  This file is part of systemd.
+
+  Copyright 2015 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <net/if.h>
+
+#include <linux/veth.h>
+
+#include <libudev.h>
+#include <systemd/sd-id128.h>
+
+#include "sd-netlink/netlink-util.h"
+#include "systemd-basic/alloc-util.h"
+#include "systemd-basic/ether-addr-util.h"
+#include "systemd-basic/lockfile-util.h"
+#include "systemd-basic/siphash24.h"
+#include "systemd-basic/socket-util.h"
+#include "systemd-basic/stat-util.h"
+#include "systemd-basic/string-util.h"
+#include "systemd-basic/util.h"
+#include "systemd-shared/udev-util.h"
+#include "systemd-staging/sd-netlink.h"
+
+#include "nspawn-network.h"
+
+#define HOST_HASH_KEY SD_ID128_MAKE(1a,37,6f,c7,46,ec,45,0b,ad,a3,d5,31,06,60,5d,b1)
+#define CONTAINER_HASH_KEY SD_ID128_MAKE(c3,c4,f9,19,b5,57,b2,1c,e6,cf,14,27,03,9c,ee,a2)
+#define VETH_EXTRA_HOST_HASH_KEY SD_ID128_MAKE(48,c7,f6,b7,ea,9d,4c,9e,b7,28,d4,de,91,d5,bf,66)
+#define VETH_EXTRA_CONTAINER_HASH_KEY SD_ID128_MAKE(af,50,17,61,ce,f9,4d,35,84,0d,2b,20,54,be,ce,59)
+#define MACVLAN_HASH_KEY SD_ID128_MAKE(00,13,6d,bc,66,83,44,81,bb,0c,f9,51,1f,24,a6,6f)
+
+static int remove_one_link(sd_netlink *rtnl, const char *name) {
+        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
+        int r;
+
+        if (isempty(name))
+                return 0;
+
+        r = sd_rtnl_message_new_link(rtnl, &m, RTM_DELLINK, 0);
+        if (r < 0)
+                return log_error_errno(r, "Failed to allocate netlink message: %m");
+
+        r = sd_netlink_message_append_string(m, IFLA_IFNAME, name);
+        if (r < 0)
+                return log_error_errno(r, "Failed to add netlink interface name: %m");
+
+        r = sd_netlink_call(rtnl, m, 0, NULL);
+        if (r == -ENODEV) /* Already gone */
+                return 0;
+        if (r < 0)
+                return log_error_errno(r, "Failed to remove interface %s: %m", name);
+
+        return 1;
+}
+
+static int generate_mac(
+                const char *machine_name,
+                struct ether_addr *mac,
+                sd_id128_t hash_key,
+                uint64_t idx) {
+
+        uint64_t result;
+        size_t l, sz;
+        uint8_t *v, *i;
+        int r;
+
+        l = strlen(machine_name);
+        sz = sizeof(sd_id128_t) + l;
+        if (idx > 0)
+                sz += sizeof(idx);
+
+        v = alloca(sz);
+
+        /* fetch some persistent data unique to the host */
+        r = sd_id128_get_machine((sd_id128_t*) v);
+        if (r < 0)
+                return r;
+
+        /* combine with some data unique (on this host) to this
+         * container instance */
+        i = mempcpy(v + sizeof(sd_id128_t), machine_name, l);
+        if (idx > 0) {
+                idx = htole64(idx);
+                memcpy(i, &idx, sizeof(idx));
+        }
+
+        /* Let's hash the host machine ID plus the container name. We
+         * use a fixed, but originally randomly created hash key here. */
+        result = htole64(siphash24(v, sz, hash_key.bytes));
+
+        assert_cc(ETH_ALEN <= sizeof(result));
+        memcpy(mac->ether_addr_octet, &result, ETH_ALEN);
+
+        /* see eth_random_addr in the kernel */
+        mac->ether_addr_octet[0] &= 0xfe;        /* clear multicast bit */
+        mac->ether_addr_octet[0] |= 0x02;        /* set local assignment bit (IEEE802) */
+
+        return 0;
+}
+
+static int add_veth(
+                sd_netlink *rtnl,
+                pid_t pid,
+                const char *ifname_host,
+                const struct ether_addr *mac_host,
+                const char *ifname_container,
+                const struct ether_addr *mac_container) {
+
+        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
+        int r;
+
+        assert(rtnl);
+        assert(ifname_host);
+        assert(mac_host);
+        assert(ifname_container);
+        assert(mac_container);
+
+        r = sd_rtnl_message_new_link(rtnl, &m, RTM_NEWLINK, 0);
+        if (r < 0)
+                return log_error_errno(r, "Failed to allocate netlink message: %m");
+
+        r = sd_netlink_message_append_string(m, IFLA_IFNAME, ifname_host);
+        if (r < 0)
+                return log_error_errno(r, "Failed to add netlink interface name: %m");
+
+        r = sd_netlink_message_append_ether_addr(m, IFLA_ADDRESS, mac_host);
+        if (r < 0)
+                return log_error_errno(r, "Failed to add netlink MAC address: %m");
+
+        r = sd_netlink_message_open_container(m, IFLA_LINKINFO);
+        if (r < 0)
+                return log_error_errno(r, "Failed to open netlink container: %m");
+
+        r = sd_netlink_message_open_container_union(m, IFLA_INFO_DATA, "veth");
+        if (r < 0)
+                return log_error_errno(r, "Failed to open netlink container: %m");
+
+        r = sd_netlink_message_open_container(m, VETH_INFO_PEER);
+        if (r < 0)
+                return log_error_errno(r, "Failed to open netlink container: %m");
+
+        r = sd_netlink_message_append_string(m, IFLA_IFNAME, ifname_container);
+        if (r < 0)
+                return log_error_errno(r, "Failed to add netlink interface name: %m");
+
+        r = sd_netlink_message_append_ether_addr(m, IFLA_ADDRESS, mac_container);
+        if (r < 0)
+                return log_error_errno(r, "Failed to add netlink MAC address: %m");
+
+        r = sd_netlink_message_append_u32(m, IFLA_NET_NS_PID, pid);
+        if (r < 0)
+                return log_error_errno(r, "Failed to add netlink namespace field: %m");
+
+        r = sd_netlink_message_close_container(m);
+        if (r < 0)
+                return log_error_errno(r, "Failed to close netlink container: %m");
+
+        r = sd_netlink_message_close_container(m);
+        if (r < 0)
+                return log_error_errno(r, "Failed to close netlink container: %m");
+
+        r = sd_netlink_message_close_container(m);
+        if (r < 0)
+                return log_error_errno(r, "Failed to close netlink container: %m");
+
+        r = sd_netlink_call(rtnl, m, 0, NULL);
+        if (r < 0)
+                return log_error_errno(r, "Failed to add new veth interfaces (%s:%s): %m", ifname_host, ifname_container);
+
+        return 0;
+}
+
+int setup_veth(const char *machine_name,
+               pid_t pid,
+               char iface_name[IFNAMSIZ],
+               bool bridge) {
+
+        _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL;
+        struct ether_addr mac_host, mac_container;
+        int r, i;
+
+        assert(machine_name);
+        assert(pid > 0);
+        assert(iface_name);
+
+        /* Use two different interface name prefixes depending whether
+         * we are in bridge mode or not. */
+        snprintf(iface_name, IFNAMSIZ - 1, "%s-%s",
+                 bridge ? "vb" : "ve", machine_name);
+
+        r = generate_mac(machine_name, &mac_container, CONTAINER_HASH_KEY, 0);
+        if (r < 0)
+                return log_error_errno(r, "Failed to generate predictable MAC address for container side: %m");
+
+        r = generate_mac(machine_name, &mac_host, HOST_HASH_KEY, 0);
+        if (r < 0)
+                return log_error_errno(r, "Failed to generate predictable MAC address for host side: %m");
+
+        r = sd_netlink_open(&rtnl);
+        if (r < 0)
+                return log_error_errno(r, "Failed to connect to netlink: %m");
+
+        r = add_veth(rtnl, pid, iface_name, &mac_host, "host0", &mac_container);
+        if (r < 0)
+                return r;
+
+        i = (int) if_nametoindex(iface_name);
+        if (i <= 0)
+                return log_error_errno(errno, "Failed to resolve interface %s: %m", iface_name);
+
+        return i;
+}
+
+int setup_veth_extra(
+                const char *machine_name,
+                pid_t pid,
+                char **pairs) {
+
+        _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL;
+        uint64_t idx = 0;
+        char **a, **b;
+        int r;
+
+        assert(machine_name);
+        assert(pid > 0);
+
+        if (strv_isempty(pairs))
+                return 0;
+
+        r = sd_netlink_open(&rtnl);
+        if (r < 0)
+                return log_error_errno(r, "Failed to connect to netlink: %m");
+
+        STRV_FOREACH_PAIR(a, b, pairs) {
+                struct ether_addr mac_host, mac_container;
+
+                r = generate_mac(machine_name, &mac_container, VETH_EXTRA_CONTAINER_HASH_KEY, idx);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to generate predictable MAC address for container side of extra veth link: %m");
+
+                r = generate_mac(machine_name, &mac_host, VETH_EXTRA_HOST_HASH_KEY, idx);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to generate predictable MAC address for container side of extra veth link: %m");
+
+                r = add_veth(rtnl, pid, *a, &mac_host, *b, &mac_container);
+                if (r < 0)
+                        return r;
+
+                idx++;
+        }
+
+        return 0;
+}
+
+static int join_bridge(sd_netlink *rtnl, const char *veth_name, const char *bridge_name) {
+        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
+        int r, bridge_ifi;
+
+        assert(rtnl);
+        assert(veth_name);
+        assert(bridge_name);
+
+        bridge_ifi = (int) if_nametoindex(bridge_name);
+        if (bridge_ifi <= 0)
+                return -errno;
+
+        r = sd_rtnl_message_new_link(rtnl, &m, RTM_SETLINK, 0);
+        if (r < 0)
+                return r;
+
+        r = sd_rtnl_message_link_set_flags(m, IFF_UP, IFF_UP);
+        if (r < 0)
+                return r;
+
+        r = sd_netlink_message_append_string(m, IFLA_IFNAME, veth_name);
+        if (r < 0)
+                return r;
+
+        r = sd_netlink_message_append_u32(m, IFLA_MASTER, bridge_ifi);
+        if (r < 0)
+                return r;
+
+        r = sd_netlink_call(rtnl, m, 0, NULL);
+        if (r < 0)
+                return r;
+
+        return bridge_ifi;
+}
+
+static int create_bridge(sd_netlink *rtnl, const char *bridge_name) {
+        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
+        int r;
+
+        r = sd_rtnl_message_new_link(rtnl, &m, RTM_NEWLINK, 0);
+        if (r < 0)
+                return r;
+
+        r = sd_netlink_message_append_string(m, IFLA_IFNAME, bridge_name);
+        if (r < 0)
+                return r;
+
+        r = sd_netlink_message_open_container(m, IFLA_LINKINFO);
+        if (r < 0)
+                return r;
+
+        r = sd_netlink_message_open_container_union(m, IFLA_INFO_DATA, "bridge");
+        if (r < 0)
+                return r;
+
+        r = sd_netlink_message_close_container(m);
+        if (r < 0)
+                return r;
+
+        r = sd_netlink_message_close_container(m);
+        if (r < 0)
+                return r;
+
+        r = sd_netlink_call(rtnl, m, 0, NULL);
+        if (r < 0)
+                return r;
+
+        return 0;
+}
+
+int setup_bridge(const char *veth_name, const char *bridge_name, bool create) {
+        _cleanup_release_lock_file_ LockFile bridge_lock = LOCK_FILE_INIT;
+        _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL;
+        int r, bridge_ifi;
+        unsigned n = 0;
+
+        assert(veth_name);
+        assert(bridge_name);
+
+        r = sd_netlink_open(&rtnl);
+        if (r < 0)
+                return log_error_errno(r, "Failed to connect to netlink: %m");
+
+        if (create) {
+                /* We take a system-wide lock here, so that we can safely check whether there's still a member in the
+                 * bridge before removing it, without risking interference from other nspawn instances. */
+
+                r = make_lock_file("/run/systemd/nspawn-network-zone", LOCK_EX, &bridge_lock);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to take network zone lock: %m");
+        }
+
+        for (;;) {
+                bridge_ifi = join_bridge(rtnl, veth_name, bridge_name);
+                if (bridge_ifi >= 0)
+                        return bridge_ifi;
+                if (bridge_ifi != -ENODEV || !create || n > 10)
+                        return log_error_errno(bridge_ifi, "Failed to add interface %s to bridge %s: %m", veth_name, bridge_name);
+
+                /* Count attempts, so that we don't enter an endless loop here. */
+                n++;
+
+                /* The bridge doesn't exist yet. Let's create it */
+                r = create_bridge(rtnl, bridge_name);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to create bridge interface %s: %m", bridge_name);
+
+                /* Try again, now that the bridge exists */
+        }
+}
+
+int remove_bridge(const char *bridge_name) {
+        _cleanup_release_lock_file_ LockFile bridge_lock = LOCK_FILE_INIT;
+        _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL;
+        const char *path;
+        int r;
+
+        /* Removes the specified bridge, but only if it is currently empty */
+
+        if (isempty(bridge_name))
+                return 0;
+
+        r = make_lock_file("/run/systemd/nspawn-network-zone", LOCK_EX, &bridge_lock);
+        if (r < 0)
+                return log_error_errno(r, "Failed to take network zone lock: %m");
+
+        path = strjoina("/sys/class/net/", bridge_name, "/brif");
+
+        r = dir_is_empty(path);
+        if (r == -ENOENT) /* Already gone? */
+                return 0;
+        if (r < 0)
+                return log_error_errno(r, "Can't detect if bridge %s is empty: %m", bridge_name);
+        if (r == 0) /* Still populated, leave it around */
+                return 0;
+
+        r = sd_netlink_open(&rtnl);
+        if (r < 0)
+                return log_error_errno(r, "Failed to connect to netlink: %m");
+
+        return remove_one_link(rtnl, bridge_name);
+}
+
+static int parse_interface(struct udev *udev, const char *name) {
+        _cleanup_udev_device_unref_ struct udev_device *d = NULL;
+        char ifi_str[2 + DECIMAL_STR_MAX(int)];
+        int ifi;
+
+        ifi = (int) if_nametoindex(name);
+        if (ifi <= 0)
+                return log_error_errno(errno, "Failed to resolve interface %s: %m", name);
+
+        sprintf(ifi_str, "n%i", ifi);
+        d = udev_device_new_from_device_id(udev, ifi_str);
+        if (!d)
+                return log_error_errno(errno, "Failed to get udev device for interface %s: %m", name);
+
+        if (udev_device_get_is_initialized(d) <= 0) {
+                log_error("Network interface %s is not initialized yet.", name);
+                return -EBUSY;
+        }
+
+        return ifi;
+}
+
+int move_network_interfaces(pid_t pid, char **ifaces) {
+        _cleanup_udev_unref_ struct udev *udev = NULL;
+        _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL;
+        char **i;
+        int r;
+
+        if (strv_isempty(ifaces))
+                return 0;
+
+        r = sd_netlink_open(&rtnl);
+        if (r < 0)
+                return log_error_errno(r, "Failed to connect to netlink: %m");
+
+        udev = udev_new();
+        if (!udev) {
+                log_error("Failed to connect to udev.");
+                return -ENOMEM;
+        }
+
+        STRV_FOREACH(i, ifaces) {
+                _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
+                int ifi;
+
+                ifi = parse_interface(udev, *i);
+                if (ifi < 0)
+                        return ifi;
+
+                r = sd_rtnl_message_new_link(rtnl, &m, RTM_SETLINK, ifi);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to allocate netlink message: %m");
+
+                r = sd_netlink_message_append_u32(m, IFLA_NET_NS_PID, pid);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to append namespace PID to netlink message: %m");
+
+                r = sd_netlink_call(rtnl, m, 0, NULL);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to move interface %s to namespace: %m", *i);
+        }
+
+        return 0;
+}
+
+int setup_macvlan(const char *machine_name, pid_t pid, char **ifaces) {
+        _cleanup_udev_unref_ struct udev *udev = NULL;
+        _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL;
+        unsigned idx = 0;
+        char **i;
+        int r;
+
+        if (strv_isempty(ifaces))
+                return 0;
+
+        r = sd_netlink_open(&rtnl);
+        if (r < 0)
+                return log_error_errno(r, "Failed to connect to netlink: %m");
+
+        udev = udev_new();
+        if (!udev) {
+                log_error("Failed to connect to udev.");
+                return -ENOMEM;
+        }
+
+        STRV_FOREACH(i, ifaces) {
+                _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
+                _cleanup_free_ char *n = NULL;
+                struct ether_addr mac;
+                int ifi;
+
+                ifi = parse_interface(udev, *i);
+                if (ifi < 0)
+                        return ifi;
+
+                r = generate_mac(machine_name, &mac, MACVLAN_HASH_KEY, idx++);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to create MACVLAN MAC address: %m");
+
+                r = sd_rtnl_message_new_link(rtnl, &m, RTM_NEWLINK, 0);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to allocate netlink message: %m");
+
+                r = sd_netlink_message_append_u32(m, IFLA_LINK, ifi);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to add netlink interface index: %m");
+
+                n = strappend("mv-", *i);
+                if (!n)
+                        return log_oom();
+
+                strshorten(n, IFNAMSIZ-1);
+
+                r = sd_netlink_message_append_string(m, IFLA_IFNAME, n);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to add netlink interface name: %m");
+
+                r = sd_netlink_message_append_ether_addr(m, IFLA_ADDRESS, &mac);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to add netlink MAC address: %m");
+
+                r = sd_netlink_message_append_u32(m, IFLA_NET_NS_PID, pid);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to add netlink namespace field: %m");
+
+                r = sd_netlink_message_open_container(m, IFLA_LINKINFO);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to open netlink container: %m");
+
+                r = sd_netlink_message_open_container_union(m, IFLA_INFO_DATA, "macvlan");
+                if (r < 0)
+                        return log_error_errno(r, "Failed to open netlink container: %m");
+
+                r = sd_netlink_message_append_u32(m, IFLA_MACVLAN_MODE, MACVLAN_MODE_BRIDGE);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to append macvlan mode: %m");
+
+                r = sd_netlink_message_close_container(m);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to close netlink container: %m");
+
+                r = sd_netlink_message_close_container(m);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to close netlink container: %m");
+
+                r = sd_netlink_call(rtnl, m, 0, NULL);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to add new macvlan interfaces: %m");
+        }
+
+        return 0;
+}
+
+int setup_ipvlan(const char *machine_name, pid_t pid, char **ifaces) {
+        _cleanup_udev_unref_ struct udev *udev = NULL;
+        _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL;
+        char **i;
+        int r;
+
+        if (strv_isempty(ifaces))
+                return 0;
+
+        r = sd_netlink_open(&rtnl);
+        if (r < 0)
+                return log_error_errno(r, "Failed to connect to netlink: %m");
+
+        udev = udev_new();
+        if (!udev) {
+                log_error("Failed to connect to udev.");
+                return -ENOMEM;
+        }
+
+        STRV_FOREACH(i, ifaces) {
+                _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
+                _cleanup_free_ char *n = NULL;
+                int ifi;
+
+                ifi = parse_interface(udev, *i);
+                if (ifi < 0)
+                        return ifi;
+
+                r = sd_rtnl_message_new_link(rtnl, &m, RTM_NEWLINK, 0);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to allocate netlink message: %m");
+
+                r = sd_netlink_message_append_u32(m, IFLA_LINK, ifi);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to add netlink interface index: %m");
+
+                n = strappend("iv-", *i);
+                if (!n)
+                        return log_oom();
+
+                strshorten(n, IFNAMSIZ-1);
+
+                r = sd_netlink_message_append_string(m, IFLA_IFNAME, n);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to add netlink interface name: %m");
+
+                r = sd_netlink_message_append_u32(m, IFLA_NET_NS_PID, pid);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to add netlink namespace field: %m");
+
+                r = sd_netlink_message_open_container(m, IFLA_LINKINFO);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to open netlink container: %m");
+
+                r = sd_netlink_message_open_container_union(m, IFLA_INFO_DATA, "ipvlan");
+                if (r < 0)
+                        return log_error_errno(r, "Failed to open netlink container: %m");
+
+                r = sd_netlink_message_append_u16(m, IFLA_IPVLAN_MODE, IPVLAN_MODE_L2);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to add ipvlan mode: %m");
+
+                r = sd_netlink_message_close_container(m);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to close netlink container: %m");
+
+                r = sd_netlink_message_close_container(m);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to close netlink container: %m");
+
+                r = sd_netlink_call(rtnl, m, 0, NULL);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to add new ipvlan interfaces: %m");
+        }
+
+        return 0;
+}
+
+int veth_extra_parse(char ***l, const char *p) {
+        _cleanup_free_ char *a = NULL, *b = NULL;
+        int r;
+
+        r = extract_first_word(&p, &a, ":", EXTRACT_DONT_COALESCE_SEPARATORS);
+        if (r < 0)
+                return r;
+        if (r == 0 || !ifname_valid(a))
+                return -EINVAL;
+
+        r = extract_first_word(&p, &b, ":", EXTRACT_DONT_COALESCE_SEPARATORS);
+        if (r < 0)
+                return r;
+        if (r == 0 || !ifname_valid(b)) {
+                free(b);
+                b = strdup(a);
+                if (!b)
+                        return -ENOMEM;
+        }
+
+        if (p)
+                return -EINVAL;
+
+        r = strv_push_pair(l, a, b);
+        if (r < 0)
+                return -ENOMEM;
+
+        a = b = NULL;
+        return 0;
+}
+
+int remove_veth_links(const char *primary, char **pairs) {
+        _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL;
+        char **a, **b;
+        int r;
+
+        /* In some cases the kernel might pin the veth links between host and container even after the namespace
+         * died. Hence, let's better remove them explicitly too. */
+
+        if (isempty(primary) && strv_isempty(pairs))
+                return 0;
+
+        r = sd_netlink_open(&rtnl);
+        if (r < 0)
+                return log_error_errno(r, "Failed to connect to netlink: %m");
+
+        remove_one_link(rtnl, primary);
+
+        STRV_FOREACH_PAIR(a, b, pairs)
+                remove_one_link(rtnl, *a);
+
+        return 0;
+}
diff --git a/src/systemd-nspawn/nspawn-network.h b/src/systemd-nspawn/nspawn-network.h
new file mode 100644
index 0000000000..3d8861e1e5
--- /dev/null
+++ b/src/systemd-nspawn/nspawn-network.h
@@ -0,0 +1,39 @@
+#pragma once
+
+/***
+  This file is part of systemd.
+
+  Copyright 2015 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <net/if.h>
+#include <stdbool.h>
+#include <sys/types.h>
+
+int setup_veth(const char *machine_name, pid_t pid, char iface_name[IFNAMSIZ], bool bridge);
+int setup_veth_extra(const char *machine_name, pid_t pid, char **pairs);
+
+int setup_bridge(const char *veth_name, const char *bridge_name, bool create);
+int remove_bridge(const char *bridge_name);
+
+int setup_macvlan(const char *machine_name, pid_t pid, char **ifaces);
+int setup_ipvlan(const char *machine_name, pid_t pid, char **ifaces);
+
+int move_network_interfaces(pid_t pid, char **ifaces);
+
+int veth_extra_parse(char ***l, const char *p);
+
+int remove_veth_links(const char *primary, char **pairs);
diff --git a/src/systemd-nspawn/nspawn-patch-uid.c b/src/systemd-nspawn/nspawn-patch-uid.c
new file mode 100644
index 0000000000..ef297ed915
--- /dev/null
+++ b/src/systemd-nspawn/nspawn-patch-uid.c
@@ -0,0 +1,483 @@
+/***
+  This file is part of systemd.
+
+  Copyright 2016 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <fcntl.h>
+
+#include <linux/magic.h>
+#ifdef HAVE_ACL
+#include <sys/acl.h>
+#endif
+#include <sys/stat.h>
+#include <sys/vfs.h>
+#include <unistd.h>
+
+#include "systemd-basic/dirent-util.h"
+#include "systemd-basic/fd-util.h"
+#include "systemd-basic/missing.h"
+#include "systemd-basic/stat-util.h"
+#include "systemd-basic/stdio-util.h"
+#include "systemd-basic/string-util.h"
+#include "systemd-basic/strv.h"
+#include "systemd-basic/user-util.h"
+#include "systemd-shared/acl-util.h"
+
+#include "nspawn-patch-uid.h"
+
+#ifdef HAVE_ACL
+
+static int get_acl(int fd, const char *name, acl_type_t type, acl_t *ret) {
+        char procfs_path[strlen("/proc/self/fd/") + DECIMAL_STR_MAX(int) + 1];
+        acl_t acl;
+
+        assert(fd >= 0);
+        assert(ret);
+
+        if (name) {
+                _cleanup_close_ int child_fd = -1;
+
+                child_fd = openat(fd, name, O_PATH|O_CLOEXEC|O_NOFOLLOW);
+                if (child_fd < 0)
+                        return -errno;
+
+                xsprintf(procfs_path, "/proc/self/fd/%i", child_fd);
+                acl = acl_get_file(procfs_path, type);
+        } else if (type == ACL_TYPE_ACCESS)
+                acl = acl_get_fd(fd);
+        else {
+                xsprintf(procfs_path, "/proc/self/fd/%i", fd);
+                acl = acl_get_file(procfs_path, type);
+        }
+        if (!acl)
+                return -errno;
+
+        *ret = acl;
+        return 0;
+}
+
+static int set_acl(int fd, const char *name, acl_type_t type, acl_t acl) {
+        char procfs_path[strlen("/proc/self/fd/") + DECIMAL_STR_MAX(int) + 1];
+        int r;
+
+        assert(fd >= 0);
+        assert(acl);
+
+        if (name) {
+                _cleanup_close_ int child_fd = -1;
+
+                child_fd = openat(fd, name, O_PATH|O_CLOEXEC|O_NOFOLLOW);
+                if (child_fd < 0)
+                        return -errno;
+
+                xsprintf(procfs_path, "/proc/self/fd/%i", child_fd);
+                r = acl_set_file(procfs_path, type, acl);
+        } else if (type == ACL_TYPE_ACCESS)
+                r = acl_set_fd(fd, acl);
+        else {
+                xsprintf(procfs_path, "/proc/self/fd/%i", fd);
+                r = acl_set_file(procfs_path, type, acl);
+        }
+        if (r < 0)
+                return -errno;
+
+        return 0;
+}
+
+static int shift_acl(acl_t acl, uid_t shift, acl_t *ret) {
+        _cleanup_(acl_freep) acl_t copy = NULL;
+        acl_entry_t i;
+        int r;
+
+        assert(acl);
+        assert(ret);
+
+        r = acl_get_entry(acl, ACL_FIRST_ENTRY, &i);
+        if (r < 0)
+                return -errno;
+        while (r > 0) {
+                uid_t *old_uid, new_uid;
+                bool modify = false;
+                acl_tag_t tag;
+
+                if (acl_get_tag_type(i, &tag) < 0)
+                        return -errno;
+
+                if (IN_SET(tag, ACL_USER, ACL_GROUP)) {
+
+                        /* We don't distuingish here between uid_t and gid_t, let's make sure the compiler checks that
+                         * this is actually OK */
+                        assert_cc(sizeof(uid_t) == sizeof(gid_t));
+
+                        old_uid = acl_get_qualifier(i);
+                        if (!old_uid)
+                                return -errno;
+
+                        new_uid = shift | (*old_uid & UINT32_C(0xFFFF));
+                        if (!uid_is_valid(new_uid))
+                                return -EINVAL;
+
+                        modify = new_uid != *old_uid;
+                        if (modify && !copy) {
+                                int n;
+
+                                /* There's no copy of the ACL yet? if so, let's create one, and start the loop from the
+                                 * beginning, so that we copy all entries, starting from the first, this time. */
+
+                                n = acl_entries(acl);
+                                if (n < 0)
+                                        return -errno;
+
+                                copy = acl_init(n);
+                                if (!copy)
+                                        return -errno;
+
+                                /* Seek back to the beginning */
+                                r = acl_get_entry(acl, ACL_FIRST_ENTRY, &i);
+                                if (r < 0)
+                                        return -errno;
+                                continue;
+                        }
+                }
+
+                if (copy) {
+                        acl_entry_t new_entry;
+
+                        if (acl_create_entry(&copy, &new_entry) < 0)
+                                return -errno;
+
+                        if (acl_copy_entry(new_entry, i) < 0)
+                                return -errno;
+
+                        if (modify)
+                                if (acl_set_qualifier(new_entry, &new_uid) < 0)
+                                        return -errno;
+                }
+
+                r = acl_get_entry(acl, ACL_NEXT_ENTRY, &i);
+                if (r < 0)
+                        return -errno;
+        }
+
+        *ret = copy;
+        copy = NULL;
+
+        return !!*ret;
+}
+
+static int patch_acls(int fd, const char *name, const struct stat *st, uid_t shift) {
+        _cleanup_(acl_freep) acl_t acl = NULL, shifted = NULL;
+        bool changed = false;
+        int r;
+
+        assert(fd >= 0);
+        assert(st);
+
+        /* ACLs are not supported on symlinks, there's no point in trying */
+        if (S_ISLNK(st->st_mode))
+                return 0;
+
+        r = get_acl(fd, name, ACL_TYPE_ACCESS, &acl);
+        if (r == -EOPNOTSUPP)
+                return 0;
+        if (r < 0)
+                return r;
+
+        r = shift_acl(acl, shift, &shifted);
+        if (r < 0)
+                return r;
+        if (r > 0) {
+                r = set_acl(fd, name, ACL_TYPE_ACCESS, shifted);
+                if (r < 0)
+                        return r;
+
+                changed = true;
+        }
+
+        if (S_ISDIR(st->st_mode)) {
+                acl_free(acl);
+                acl_free(shifted);
+
+                acl = shifted = NULL;
+
+                r = get_acl(fd, name, ACL_TYPE_DEFAULT, &acl);
+                if (r < 0)
+                        return r;
+
+                r = shift_acl(acl, shift, &shifted);
+                if (r < 0)
+                        return r;
+                if (r > 0) {
+                        r = set_acl(fd, name, ACL_TYPE_DEFAULT, shifted);
+                        if (r < 0)
+                                return r;
+
+                        changed = true;
+                }
+        }
+
+        return changed;
+}
+
+#else
+
+static int patch_acls(int fd, const char *name, const struct stat *st, uid_t shift) {
+        return 0;
+}
+
+#endif
+
+static int patch_fd(int fd, const char *name, const struct stat *st, uid_t shift) {
+        uid_t new_uid;
+        gid_t new_gid;
+        bool changed = false;
+        int r;
+
+        assert(fd >= 0);
+        assert(st);
+
+        new_uid =         shift | (st->st_uid & UINT32_C(0xFFFF));
+        new_gid = (gid_t) shift | (st->st_gid & UINT32_C(0xFFFF));
+
+        if (!uid_is_valid(new_uid) || !gid_is_valid(new_gid))
+                return -EINVAL;
+
+        if (st->st_uid != new_uid || st->st_gid != new_gid) {
+                if (name)
+                        r = fchownat(fd, name, new_uid, new_gid, AT_SYMLINK_NOFOLLOW);
+                else
+                        r = fchown(fd, new_uid, new_gid);
+                if (r < 0)
+                        return -errno;
+
+                /* The Linux kernel alters the mode in some cases of chown(). Let's undo this. */
+                if (name) {
+                        if (!S_ISLNK(st->st_mode))
+                                r = fchmodat(fd, name, st->st_mode, 0);
+                        else /* AT_SYMLINK_NOFOLLOW is not available for fchmodat() */
+                                r = 0;
+                } else
+                        r = fchmod(fd, st->st_mode);
+                if (r < 0)
+                        return -errno;
+
+                changed = true;
+        }
+
+        r = patch_acls(fd, name, st, shift);
+        if (r < 0)
+                return r;
+
+        return r > 0 || changed;
+}
+
+/*
+ * Check if the filesystem is fully compatible with user namespaces or
+ * UID/GID patching. Some filesystems in this list can be fully mounted inside
+ * user namespaces, however their inodes may relate to host resources or only
+ * valid in the global user namespace, therefore no patching should be applied.
+ */
+static int is_fs_fully_userns_compatible(int fd) {
+        struct statfs sfs;
+
+        assert(fd >= 0);
+
+        if (fstatfs(fd, &sfs) < 0)
+                return -errno;
+
+        return F_TYPE_EQUAL(sfs.f_type, BINFMTFS_MAGIC) ||
+               F_TYPE_EQUAL(sfs.f_type, CGROUP_SUPER_MAGIC) ||
+               F_TYPE_EQUAL(sfs.f_type, CGROUP2_SUPER_MAGIC) ||
+               F_TYPE_EQUAL(sfs.f_type, DEBUGFS_MAGIC) ||
+               F_TYPE_EQUAL(sfs.f_type, DEVPTS_SUPER_MAGIC) ||
+               F_TYPE_EQUAL(sfs.f_type, EFIVARFS_MAGIC) ||
+               F_TYPE_EQUAL(sfs.f_type, HUGETLBFS_MAGIC) ||
+               F_TYPE_EQUAL(sfs.f_type, MQUEUE_MAGIC) ||
+               F_TYPE_EQUAL(sfs.f_type, PROC_SUPER_MAGIC) ||
+               F_TYPE_EQUAL(sfs.f_type, PSTOREFS_MAGIC) ||
+               F_TYPE_EQUAL(sfs.f_type, SELINUX_MAGIC) ||
+               F_TYPE_EQUAL(sfs.f_type, SMACK_MAGIC) ||
+               F_TYPE_EQUAL(sfs.f_type, SECURITYFS_MAGIC) ||
+               F_TYPE_EQUAL(sfs.f_type, BPF_FS_MAGIC) ||
+               F_TYPE_EQUAL(sfs.f_type, TRACEFS_MAGIC) ||
+               F_TYPE_EQUAL(sfs.f_type, SYSFS_MAGIC);
+}
+
+static int recurse_fd(int fd, bool donate_fd, const struct stat *st, uid_t shift, bool is_toplevel) {
+        bool changed = false;
+        int r;
+
+        assert(fd >= 0);
+
+        /* We generally want to permit crossing of mount boundaries when patching the UIDs/GIDs. However, we
+         * probably shouldn't do this for /proc and /sys if that is already mounted into place. Hence, let's
+         * stop the recursion when we hit procfs, sysfs or some other special file systems. */
+        r = is_fs_fully_userns_compatible(fd);
+        if (r < 0)
+                goto finish;
+        if (r > 0) {
+                r = 0; /* don't recurse */
+                goto finish;
+        }
+
+        r = patch_fd(fd, NULL, st, shift);
+        if (r == -EROFS) {
+                _cleanup_free_ char *name = NULL;
+
+                if (!is_toplevel) {
+                        /* When we hit a ready-only subtree we simply skip it, but log about it. */
+                        (void) fd_get_path(fd, &name);
+                        log_debug("Skippping read-only file or directory %s.", strna(name));
+                        r = 0;
+                }
+
+                goto finish;
+        }
+        if (r < 0)
+                goto finish;
+
+        if (S_ISDIR(st->st_mode)) {
+                _cleanup_closedir_ DIR *d = NULL;
+                struct dirent *de;
+
+                if (!donate_fd) {
+                        int copy;
+
+                        copy = fcntl(fd, F_DUPFD_CLOEXEC, 3);
+                        if (copy < 0) {
+                                r = -errno;
+                                goto finish;
+                        }
+
+                        fd = copy;
+                        donate_fd = true;
+                }
+
+                d = fdopendir(fd);
+                if (!d) {
+                        r = -errno;
+                        goto finish;
+                }
+                fd = -1;
+
+                FOREACH_DIRENT_ALL(de, d, r = -errno; goto finish) {
+                        struct stat fst;
+
+                        if (STR_IN_SET(de->d_name, ".", ".."))
+                                continue;
+
+                        if (fstatat(dirfd(d), de->d_name, &fst, AT_SYMLINK_NOFOLLOW) < 0) {
+                                r = -errno;
+                                goto finish;
+                        }
+
+                        if (S_ISDIR(fst.st_mode)) {
+                                int subdir_fd;
+
+                                subdir_fd = openat(dirfd(d), de->d_name, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC|O_NOFOLLOW|O_NOATIME);
+                                if (subdir_fd < 0) {
+                                        r = -errno;
+                                        goto finish;
+
+                                }
+
+                                r = recurse_fd(subdir_fd, true, &fst, shift, false);
+                                if (r < 0)
+                                        goto finish;
+                                if (r > 0)
+                                        changed = true;
+
+                        } else {
+                                r = patch_fd(dirfd(d), de->d_name, &fst, shift);
+                                if (r < 0)
+                                        goto finish;
+                                if (r > 0)
+                                        changed = true;
+                        }
+                }
+        }
+
+        r = changed;
+
+finish:
+        if (donate_fd)
+                safe_close(fd);
+
+        return r;
+}
+
+static int fd_patch_uid_internal(int fd, bool donate_fd, uid_t shift, uid_t range) {
+        struct stat st;
+        int r;
+
+        assert(fd >= 0);
+
+        /* Recursively adjusts the UID/GIDs of all files of a directory tree. This is used to automatically fix up an
+         * OS tree to the used user namespace UID range. Note that this automatic adjustment only works for UID ranges
+         * following the concept that the upper 16bit of a UID identify the container, and the lower 16bit are the actual
+         * UID within the container. */
+
+        if ((shift & 0xFFFF) != 0) {
+                /* We only support containers where the shift starts at a 2^16 boundary */
+                r = -EOPNOTSUPP;
+                goto finish;
+        }
+
+        if (range != 0x10000) {
+                /* We only support containers with 16bit UID ranges for the patching logic */
+                r = -EOPNOTSUPP;
+                goto finish;
+        }
+
+        if (fstat(fd, &st) < 0) {
+                r = -errno;
+                goto finish;
+        }
+
+        if ((uint32_t) st.st_uid >> 16 != (uint32_t) st.st_gid >> 16) {
+                /* We only support containers where the uid/gid container ID match */
+                r = -EBADE;
+                goto finish;
+        }
+
+        /* Try to detect if the range is already right. Of course, this a pretty drastic optimization, as we assume
+         * that if the top-level dir has the right upper 16bit assigned, then everything below will have too... */
+        if (((uint32_t) (st.st_uid ^ shift) >> 16) == 0)
+                return 0;
+
+        return recurse_fd(fd, donate_fd, &st, shift, true);
+
+finish:
+        if (donate_fd)
+                safe_close(fd);
+
+        return r;
+}
+
+int fd_patch_uid(int fd, uid_t shift, uid_t range) {
+        return fd_patch_uid_internal(fd, false, shift, range);
+}
+
+int path_patch_uid(const char *path, uid_t shift, uid_t range) {
+        int fd;
+
+        fd = open(path, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC|O_NOFOLLOW|O_NOATIME);
+        if (fd < 0)
+                return -errno;
+
+        return fd_patch_uid_internal(fd, true, shift, range);
+}
diff --git a/src/systemd-nspawn/nspawn-patch-uid.h b/src/systemd-nspawn/nspawn-patch-uid.h
new file mode 100644
index 0000000000..55d0990016
--- /dev/null
+++ b/src/systemd-nspawn/nspawn-patch-uid.h
@@ -0,0 +1,23 @@
+/***
+  This file is part of systemd.
+
+  Copyright 2016 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <sys/types.h>
+
+int fd_patch_uid(int fd, uid_t shift, uid_t range);
+int path_patch_uid(const char *path, uid_t shift, uid_t range);
diff --git a/src/systemd-nspawn/nspawn-register.c b/src/systemd-nspawn/nspawn-register.c
new file mode 100644
index 0000000000..de3ee23f09
--- /dev/null
+++ b/src/systemd-nspawn/nspawn-register.c
@@ -0,0 +1,227 @@
+/***
+  This file is part of systemd.
+
+  Copyright 2015 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <systemd/sd-bus.h>
+
+#include "sd-bus/bus-error.h"
+#include "sd-bus/bus-util.h"
+#include "systemd-basic/stat-util.h"
+#include "systemd-basic/strv.h"
+#include "systemd-basic/util.h"
+#include "systemd-shared/bus-unit-util.h"
+
+#include "nspawn-register.h"
+
+int register_machine(
+                const char *machine_name,
+                pid_t pid,
+                const char *directory,
+                sd_id128_t uuid,
+                int local_ifindex,
+                const char *slice,
+                CustomMount *mounts,
+                unsigned n_mounts,
+                int kill_signal,
+                char **properties,
+                bool keep_unit,
+                const char *service) {
+
+        _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
+        _cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL;
+        int r;
+
+        r = sd_bus_default_system(&bus);
+        if (r < 0)
+                return log_error_errno(r, "Failed to open system bus: %m");
+
+        if (keep_unit) {
+                r = sd_bus_call_method(
+                                bus,
+                                "org.freedesktop.machine1",
+                                "/org/freedesktop/machine1",
+                                "org.freedesktop.machine1.Manager",
+                                "RegisterMachineWithNetwork",
+                                &error,
+                                NULL,
+                                "sayssusai",
+                                machine_name,
+                                SD_BUS_MESSAGE_APPEND_ID128(uuid),
+                                service,
+                                "container",
+                                (uint32_t) pid,
+                                strempty(directory),
+                                local_ifindex > 0 ? 1 : 0, local_ifindex);
+        } else {
+                _cleanup_(sd_bus_message_unrefp) sd_bus_message *m = NULL;
+                unsigned j;
+
+                r = sd_bus_message_new_method_call(
+                                bus,
+                                &m,
+                                "org.freedesktop.machine1",
+                                "/org/freedesktop/machine1",
+                                "org.freedesktop.machine1.Manager",
+                                "CreateMachineWithNetwork");
+                if (r < 0)
+                        return bus_log_create_error(r);
+
+                r = sd_bus_message_append(
+                                m,
+                                "sayssusai",
+                                machine_name,
+                                SD_BUS_MESSAGE_APPEND_ID128(uuid),
+                                service,
+                                "container",
+                                (uint32_t) pid,
+                                strempty(directory),
+                                local_ifindex > 0 ? 1 : 0, local_ifindex);
+                if (r < 0)
+                        return bus_log_create_error(r);
+
+                r = sd_bus_message_open_container(m, 'a', "(sv)");
+                if (r < 0)
+                        return bus_log_create_error(r);
+
+                if (!isempty(slice)) {
+                        r = sd_bus_message_append(m, "(sv)", "Slice", "s", slice);
+                        if (r < 0)
+                                return bus_log_create_error(r);
+                }
+
+                r = sd_bus_message_append(m, "(sv)", "DevicePolicy", "s", "closed");
+                if (r < 0)
+                        return bus_log_create_error(r);
+
+                /* If you make changes here, also make sure to update
+                 * systemd-nspawn@.service, to keep the device
+                 * policies in sync regardless if we are run with or
+                 * without the --keep-unit switch. */
+                r = sd_bus_message_append(m, "(sv)", "DeviceAllow", "a(ss)", 2,
+                                          /* Allow the container to
+                                           * access and create the API
+                                           * device nodes, so that
+                                           * PrivateDevices= in the
+                                           * container can work
+                                           * fine */
+                                          "/dev/net/tun", "rwm",
+                                          /* Allow the container
+                                           * access to ptys. However,
+                                           * do not permit the
+                                           * container to ever create
+                                           * these device nodes. */
+                                          "char-pts", "rw");
+                if (r < 0)
+                        return bus_log_create_error(r);
+
+                for (j = 0; j < n_mounts; j++) {
+                        CustomMount *cm = mounts + j;
+
+                        if (cm->type != CUSTOM_MOUNT_BIND)
+                                continue;
+
+                        r = is_device_node(cm->source);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to stat %s: %m", cm->source);
+
+                        if (r) {
+                                r = sd_bus_message_append(m, "(sv)", "DeviceAllow", "a(ss)", 1,
+                                        cm->source, cm->read_only ? "r" : "rw");
+                                if (r < 0)
+                                        return log_error_errno(r, "Failed to append message arguments: %m");
+                        }
+                }
+
+                if (kill_signal != 0) {
+                        r = sd_bus_message_append(m, "(sv)", "KillSignal", "i", kill_signal);
+                        if (r < 0)
+                                return bus_log_create_error(r);
+
+                        r = sd_bus_message_append(m, "(sv)", "KillMode", "s", "mixed");
+                        if (r < 0)
+                                return bus_log_create_error(r);
+                }
+
+                r = bus_append_unit_property_assignment_many(m, properties);
+                if (r < 0)
+                        return r;
+
+                r = sd_bus_message_close_container(m);
+                if (r < 0)
+                        return bus_log_create_error(r);
+
+                r = sd_bus_call(bus, m, 0, &error, NULL);
+        }
+
+        if (r < 0) {
+                log_error("Failed to register machine: %s", bus_error_message(&error, r));
+                return r;
+        }
+
+        return 0;
+}
+
+int terminate_machine(pid_t pid) {
+        _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
+        _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL;
+        _cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL;
+        const char *path;
+        int r;
+
+        r = sd_bus_default_system(&bus);
+        if (r < 0)
+                return log_error_errno(r, "Failed to open system bus: %m");
+
+        r = sd_bus_call_method(
+                        bus,
+                        "org.freedesktop.machine1",
+                        "/org/freedesktop/machine1",
+                        "org.freedesktop.machine1.Manager",
+                        "GetMachineByPID",
+                        &error,
+                        &reply,
+                        "u",
+                        (uint32_t) pid);
+        if (r < 0) {
+                /* Note that the machine might already have been
+                 * cleaned up automatically, hence don't consider it a
+                 * failure if we cannot get the machine object. */
+                log_debug("Failed to get machine: %s", bus_error_message(&error, r));
+                return 0;
+        }
+
+        r = sd_bus_message_read(reply, "o", &path);
+        if (r < 0)
+                return bus_log_parse_error(r);
+
+        r = sd_bus_call_method(
+                        bus,
+                        "org.freedesktop.machine1",
+                        path,
+                        "org.freedesktop.machine1.Machine",
+                        "Terminate",
+                        &error,
+                        NULL,
+                        NULL);
+        if (r < 0) {
+                log_debug("Failed to terminate machine: %s", bus_error_message(&error, r));
+                return 0;
+        }
+
+        return 0;
+}
diff --git a/src/systemd-nspawn/nspawn-register.h b/src/systemd-nspawn/nspawn-register.h
new file mode 100644
index 0000000000..c7a50f7477
--- /dev/null
+++ b/src/systemd-nspawn/nspawn-register.h
@@ -0,0 +1,29 @@
+#pragma once
+
+/***
+  This file is part of systemd.
+
+  Copyright 2015 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <sys/types.h>
+
+#include <systemd/sd-id128.h>
+
+#include "nspawn-mount.h"
+
+int register_machine(const char *machine_name, pid_t pid, const char *directory, sd_id128_t uuid, int local_ifindex, const char *slice, CustomMount *mounts, unsigned n_mounts, int kill_signal, char **properties, bool keep_unit, const char *service);
+int terminate_machine(pid_t pid);
diff --git a/src/systemd-nspawn/nspawn-seccomp.c b/src/systemd-nspawn/nspawn-seccomp.c
new file mode 100644
index 0000000000..e5cfe789a1
--- /dev/null
+++ b/src/systemd-nspawn/nspawn-seccomp.c
@@ -0,0 +1,186 @@
+/***
+  This file is part of systemd.
+
+  Copyright 2016 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <errno.h>
+#include <sys/capability.h>
+#include <sys/types.h>
+
+#include <linux/netlink.h>
+
+#ifdef HAVE_SECCOMP
+#include <seccomp.h>
+#endif
+
+#include "systemd-basic/log.h"
+
+#ifdef HAVE_SECCOMP
+#include "systemd-shared/seccomp-util.h"
+#endif
+
+#include "nspawn-seccomp.h"
+
+#ifdef HAVE_SECCOMP
+
+static int seccomp_add_default_syscall_filter(scmp_filter_ctx ctx,
+                                              uint64_t cap_list_retain) {
+        unsigned i;
+        int r;
+        static const struct {
+                uint64_t capability;
+                int syscall_num;
+        } blacklist[] = {
+                { 0,              SCMP_SYS(_sysctl)             }, /* obsolete syscall */
+                { 0,              SCMP_SYS(add_key)             }, /* keyring is not namespaced */
+                { 0,              SCMP_SYS(afs_syscall)         }, /* obsolete syscall */
+                { 0,              SCMP_SYS(bdflush)             },
+#ifdef __NR_bpf
+                { 0,              SCMP_SYS(bpf)                 },
+#endif
+                { 0,              SCMP_SYS(break)               }, /* obsolete syscall */
+                { 0,              SCMP_SYS(create_module)       }, /* obsolete syscall */
+                { 0,              SCMP_SYS(ftime)               }, /* obsolete syscall */
+                { 0,              SCMP_SYS(get_kernel_syms)     }, /* obsolete syscall */
+                { 0,              SCMP_SYS(getpmsg)             }, /* obsolete syscall */
+                { 0,              SCMP_SYS(gtty)                }, /* obsolete syscall */
+#ifdef __NR_kexec_file_load
+                { 0,              SCMP_SYS(kexec_file_load)     },
+#endif
+                { 0,              SCMP_SYS(kexec_load)          },
+                { 0,              SCMP_SYS(keyctl)              }, /* keyring is not namespaced */
+                { 0,              SCMP_SYS(lock)                }, /* obsolete syscall */
+                { 0,              SCMP_SYS(lookup_dcookie)      },
+                { 0,              SCMP_SYS(mpx)                 }, /* obsolete syscall */
+                { 0,              SCMP_SYS(nfsservctl)          }, /* obsolete syscall */
+                { 0,              SCMP_SYS(open_by_handle_at)   },
+                { 0,              SCMP_SYS(perf_event_open)     },
+                { 0,              SCMP_SYS(prof)                }, /* obsolete syscall */
+                { 0,              SCMP_SYS(profil)              }, /* obsolete syscall */
+                { 0,              SCMP_SYS(putpmsg)             }, /* obsolete syscall */
+                { 0,              SCMP_SYS(query_module)        }, /* obsolete syscall */
+                { 0,              SCMP_SYS(quotactl)            },
+                { 0,              SCMP_SYS(request_key)         }, /* keyring is not namespaced */
+                { 0,              SCMP_SYS(security)            }, /* obsolete syscall */
+                { 0,              SCMP_SYS(sgetmask)            }, /* obsolete syscall */
+                { 0,              SCMP_SYS(ssetmask)            }, /* obsolete syscall */
+                { 0,              SCMP_SYS(stty)                }, /* obsolete syscall */
+                { 0,              SCMP_SYS(swapoff)             },
+                { 0,              SCMP_SYS(swapon)              },
+                { 0,              SCMP_SYS(sysfs)               }, /* obsolete syscall */
+                { 0,              SCMP_SYS(tuxcall)             }, /* obsolete syscall */
+                { 0,              SCMP_SYS(ulimit)              }, /* obsolete syscall */
+                { 0,              SCMP_SYS(uselib)              }, /* obsolete syscall */
+                { 0,              SCMP_SYS(ustat)               }, /* obsolete syscall */
+                { 0,              SCMP_SYS(vserver)             }, /* obsolete syscall */
+                { CAP_SYSLOG,     SCMP_SYS(syslog)              },
+                { CAP_SYS_MODULE, SCMP_SYS(delete_module)       },
+                { CAP_SYS_MODULE, SCMP_SYS(finit_module)        },
+                { CAP_SYS_MODULE, SCMP_SYS(init_module)         },
+                { CAP_SYS_PACCT,  SCMP_SYS(acct)                },
+                { CAP_SYS_PTRACE, SCMP_SYS(process_vm_readv)    },
+                { CAP_SYS_PTRACE, SCMP_SYS(process_vm_writev)   },
+                { CAP_SYS_PTRACE, SCMP_SYS(ptrace)              },
+                { CAP_SYS_RAWIO,  SCMP_SYS(ioperm)              },
+                { CAP_SYS_RAWIO,  SCMP_SYS(iopl)                },
+                { CAP_SYS_RAWIO,  SCMP_SYS(pciconfig_iobase)    },
+                { CAP_SYS_RAWIO,  SCMP_SYS(pciconfig_read)      },
+                { CAP_SYS_RAWIO,  SCMP_SYS(pciconfig_write)     },
+#ifdef __NR_s390_pci_mmio_read
+                { CAP_SYS_RAWIO,  SCMP_SYS(s390_pci_mmio_read)  },
+#endif
+#ifdef __NR_s390_pci_mmio_write
+                { CAP_SYS_RAWIO,  SCMP_SYS(s390_pci_mmio_write) },
+#endif
+                { CAP_SYS_TIME,   SCMP_SYS(adjtimex)            },
+                { CAP_SYS_TIME,   SCMP_SYS(clock_adjtime)       },
+                { CAP_SYS_TIME,   SCMP_SYS(clock_settime)       },
+                { CAP_SYS_TIME,   SCMP_SYS(settimeofday)        },
+                { CAP_SYS_TIME,   SCMP_SYS(stime)               },
+        };
+
+        for (i = 0; i < ELEMENTSOF(blacklist); i++) {
+                if (blacklist[i].capability != 0 && (cap_list_retain & (1ULL << blacklist[i].capability)))
+                        continue;
+
+                r = seccomp_rule_add(ctx, SCMP_ACT_ERRNO(EPERM), blacklist[i].syscall_num, 0);
+                if (r == -EFAULT)
+                        continue; /* unknown syscall */
+                if (r < 0)
+                        return log_error_errno(r, "Failed to block syscall: %m");
+        }
+
+        return 0;
+}
+
+int setup_seccomp(uint64_t cap_list_retain) {
+        scmp_filter_ctx seccomp;
+        int r;
+
+        if (!is_seccomp_available()) {
+                log_debug("SECCOMP features not detected in the kernel, disabling SECCOMP audit filter");
+                return 0;
+        }
+
+        r = seccomp_init_conservative(&seccomp, SCMP_ACT_ALLOW);
+        if (r < 0)
+                return log_error_errno(r, "Failed to allocate seccomp object: %m");
+
+        r = seccomp_add_default_syscall_filter(seccomp, cap_list_retain);
+        if (r < 0)
+                goto finish;
+
+        /*
+           Audit is broken in containers, much of the userspace audit
+           hookup will fail if running inside a container. We don't
+           care and just turn off creation of audit sockets.
+
+           This will make socket(AF_NETLINK, *, NETLINK_AUDIT) fail
+           with EAFNOSUPPORT which audit userspace uses as indication
+           that audit is disabled in the kernel.
+         */
+
+        r = seccomp_rule_add(
+                        seccomp,
+                        SCMP_ACT_ERRNO(EAFNOSUPPORT),
+                        SCMP_SYS(socket),
+                        2,
+                        SCMP_A0(SCMP_CMP_EQ, AF_NETLINK),
+                        SCMP_A2(SCMP_CMP_EQ, NETLINK_AUDIT));
+        if (r < 0) {
+                log_error_errno(r, "Failed to add audit seccomp rule: %m");
+                goto finish;
+        }
+
+        r = seccomp_load(seccomp);
+        if (r < 0) {
+                log_error_errno(r, "Failed to install seccomp audit filter: %m");
+                goto finish;
+        }
+
+finish:
+        seccomp_release(seccomp);
+        return r;
+}
+
+#else
+
+int setup_seccomp(uint64_t cap_list_retain) {
+        return 0;
+}
+
+#endif
diff --git a/src/systemd-nspawn/nspawn-seccomp.h b/src/systemd-nspawn/nspawn-seccomp.h
new file mode 100644
index 0000000000..5bde16faf9
--- /dev/null
+++ b/src/systemd-nspawn/nspawn-seccomp.h
@@ -0,0 +1,24 @@
+#pragma once
+
+/***
+  This file is part of systemd.
+
+  Copyright 2016 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <sys/types.h>
+
+int setup_seccomp(uint64_t cap_list_retain);
diff --git a/src/systemd-nspawn/nspawn-settings.c b/src/systemd-nspawn/nspawn-settings.c
new file mode 100644
index 0000000000..6c1614b276
--- /dev/null
+++ b/src/systemd-nspawn/nspawn-settings.c
@@ -0,0 +1,515 @@
+/***
+  This file is part of systemd.
+
+  Copyright 2015 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include "systemd-basic/alloc-util.h"
+#include "systemd-basic/cap-list.h"
+#include "systemd-basic/parse-util.h"
+#include "systemd-basic/process-util.h"
+#include "systemd-basic/socket-util.h"
+#include "systemd-basic/string-util.h"
+#include "systemd-basic/strv.h"
+#include "systemd-basic/user-util.h"
+#include "systemd-basic/util.h"
+#include "systemd-shared/conf-parser.h"
+
+#include "nspawn-network.h"
+#include "nspawn-settings.h"
+
+int settings_load(FILE *f, const char *path, Settings **ret) {
+        _cleanup_(settings_freep) Settings *s = NULL;
+        int r;
+
+        assert(path);
+        assert(ret);
+
+        s = new0(Settings, 1);
+        if (!s)
+                return -ENOMEM;
+
+        s->start_mode = _START_MODE_INVALID;
+        s->personality = PERSONALITY_INVALID;
+        s->userns_mode = _USER_NAMESPACE_MODE_INVALID;
+        s->uid_shift = UID_INVALID;
+        s->uid_range = UID_INVALID;
+
+        s->read_only = -1;
+        s->volatile_mode = _VOLATILE_MODE_INVALID;
+        s->userns_chown = -1;
+
+        s->private_network = -1;
+        s->network_veth = -1;
+
+        r = config_parse(NULL, path, f,
+                         "Exec\0"
+                         "Network\0"
+                         "Files\0",
+                         config_item_perf_lookup, nspawn_gperf_lookup,
+                         false,
+                         false,
+                         true,
+                         s);
+        if (r < 0)
+                return r;
+
+        /* Make sure that if userns_mode is set, userns_chown is set to something appropriate, and vice versa. Either
+         * both fields shall be initialized or neither. */
+        if (s->userns_mode == USER_NAMESPACE_PICK)
+                s->userns_chown = true;
+        else if (s->userns_mode != _USER_NAMESPACE_MODE_INVALID && s->userns_chown < 0)
+                s->userns_chown = false;
+
+        if (s->userns_chown >= 0 && s->userns_mode == _USER_NAMESPACE_MODE_INVALID)
+                s->userns_mode = USER_NAMESPACE_NO;
+
+        *ret = s;
+        s = NULL;
+
+        return 0;
+}
+
+Settings* settings_free(Settings *s) {
+
+        if (!s)
+                return NULL;
+
+        strv_free(s->parameters);
+        strv_free(s->environment);
+        free(s->user);
+        free(s->working_directory);
+
+        strv_free(s->network_interfaces);
+        strv_free(s->network_macvlan);
+        strv_free(s->network_ipvlan);
+        strv_free(s->network_veth_extra);
+        free(s->network_bridge);
+        free(s->network_zone);
+        expose_port_free_all(s->expose_ports);
+
+        custom_mount_free_all(s->custom_mounts, s->n_custom_mounts);
+        return mfree(s);
+}
+
+bool settings_private_network(Settings *s) {
+        assert(s);
+
+        return
+                s->private_network > 0 ||
+                s->network_veth > 0 ||
+                s->network_bridge ||
+                s->network_zone ||
+                s->network_interfaces ||
+                s->network_macvlan ||
+                s->network_ipvlan ||
+                s->network_veth_extra;
+}
+
+bool settings_network_veth(Settings *s) {
+        assert(s);
+
+        return
+                s->network_veth > 0 ||
+                s->network_bridge ||
+                s->network_zone;
+}
+
+DEFINE_CONFIG_PARSE_ENUM(config_parse_volatile_mode, volatile_mode, VolatileMode, "Failed to parse volatile mode");
+
+int config_parse_expose_port(
+                const char *unit,
+                const char *filename,
+                unsigned line,
+                const char *section,
+                unsigned section_line,
+                const char *lvalue,
+                int ltype,
+                const char *rvalue,
+                void *data,
+                void *userdata) {
+
+        Settings *s = data;
+        int r;
+
+        assert(filename);
+        assert(lvalue);
+        assert(rvalue);
+
+        r = expose_port_parse(&s->expose_ports, rvalue);
+        if (r == -EEXIST) {
+                log_syntax(unit, LOG_ERR, filename, line, r, "Duplicate port specification, ignoring: %s", rvalue);
+                return 0;
+        }
+        if (r < 0) {
+                log_syntax(unit, LOG_ERR, filename, line, r, "Failed to parse host port %s: %m", rvalue);
+                return 0;
+        }
+
+        return 0;
+}
+
+int config_parse_capability(
+                const char *unit,
+                const char *filename,
+                unsigned line,
+                const char *section,
+                unsigned section_line,
+                const char *lvalue,
+                int ltype,
+                const char *rvalue,
+                void *data,
+                void *userdata) {
+
+        uint64_t u = 0, *result = data;
+        int r;
+
+        assert(filename);
+        assert(lvalue);
+        assert(rvalue);
+
+        for (;;) {
+                _cleanup_free_ char *word = NULL;
+                int cap;
+
+                r = extract_first_word(&rvalue, &word, NULL, 0);
+                if (r < 0) {
+                        log_syntax(unit, LOG_ERR, filename, line, r, "Failed to extract capability string, ignoring: %s", rvalue);
+                        return 0;
+                }
+                if (r == 0)
+                        break;
+
+                cap = capability_from_name(word);
+                if (cap < 0) {
+                        log_syntax(unit, LOG_ERR, filename, line, 0, "Failed to parse capability, ignoring: %s", word);
+                        continue;
+                }
+
+                u |= 1 << ((uint64_t) cap);
+        }
+
+        if (u == 0)
+                return 0;
+
+        *result |= u;
+        return 0;
+}
+
+int config_parse_id128(
+                const char *unit,
+                const char *filename,
+                unsigned line,
+                const char *section,
+                unsigned section_line,
+                const char *lvalue,
+                int ltype,
+                const char *rvalue,
+                void *data,
+                void *userdata) {
+
+        sd_id128_t t, *result = data;
+        int r;
+
+        assert(filename);
+        assert(lvalue);
+        assert(rvalue);
+
+        r = sd_id128_from_string(rvalue, &t);
+        if (r < 0) {
+                log_syntax(unit, LOG_ERR, filename, line, r, "Failed to parse 128bit ID/UUID, ignoring: %s", rvalue);
+                return 0;
+        }
+
+        *result = t;
+        return 0;
+}
+
+int config_parse_bind(
+                const char *unit,
+                const char *filename,
+                unsigned line,
+                const char *section,
+                unsigned section_line,
+                const char *lvalue,
+                int ltype,
+                const char *rvalue,
+                void *data,
+                void *userdata) {
+
+        Settings *settings = data;
+        int r;
+
+        assert(filename);
+        assert(lvalue);
+        assert(rvalue);
+
+        r = bind_mount_parse(&settings->custom_mounts, &settings->n_custom_mounts, rvalue, ltype);
+        if (r < 0) {
+                log_syntax(unit, LOG_ERR, filename, line, r, "Invalid bind mount specification %s: %m", rvalue);
+                return 0;
+        }
+
+        return 0;
+}
+
+int config_parse_tmpfs(
+                const char *unit,
+                const char *filename,
+                unsigned line,
+                const char *section,
+                unsigned section_line,
+                const char *lvalue,
+                int ltype,
+                const char *rvalue,
+                void *data,
+                void *userdata) {
+
+        Settings *settings = data;
+        int r;
+
+        assert(filename);
+        assert(lvalue);
+        assert(rvalue);
+
+        r = tmpfs_mount_parse(&settings->custom_mounts, &settings->n_custom_mounts, rvalue);
+        if (r < 0) {
+                log_syntax(unit, LOG_ERR, filename, line, r, "Invalid temporary file system specification %s: %m", rvalue);
+                return 0;
+        }
+
+        return 0;
+}
+
+int config_parse_veth_extra(
+                const char *unit,
+                const char *filename,
+                unsigned line,
+                const char *section,
+                unsigned section_line,
+                const char *lvalue,
+                int ltype,
+                const char *rvalue,
+                void *data,
+                void *userdata) {
+
+        Settings *settings = data;
+        int r;
+
+        assert(filename);
+        assert(lvalue);
+        assert(rvalue);
+
+        r = veth_extra_parse(&settings->network_veth_extra, rvalue);
+        if (r < 0) {
+                log_syntax(unit, LOG_ERR, filename, line, r, "Invalid extra virtual Ethernet link specification %s: %m", rvalue);
+                return 0;
+        }
+
+        return 0;
+}
+
+int config_parse_network_zone(
+                const char *unit,
+                const char *filename,
+                unsigned line,
+                const char *section,
+                unsigned section_line,
+                const char *lvalue,
+                int ltype,
+                const char *rvalue,
+                void *data,
+                void *userdata) {
+
+        Settings *settings = data;
+        _cleanup_free_ char *j = NULL;
+
+        assert(filename);
+        assert(lvalue);
+        assert(rvalue);
+
+        j = strappend("vz-", rvalue);
+        if (!ifname_valid(j)) {
+                log_syntax(unit, LOG_ERR, filename, line, 0, "Invalid network zone name %s, ignoring: %m", rvalue);
+                return 0;
+        }
+
+        free(settings->network_zone);
+        settings->network_zone = j;
+        j = NULL;
+
+        return 0;
+}
+
+int config_parse_boot(
+                const char *unit,
+                const char *filename,
+                unsigned line,
+                const char *section,
+                unsigned section_line,
+                const char *lvalue,
+                int ltype,
+                const char *rvalue,
+                void *data,
+                void *userdata) {
+
+        Settings *settings = data;
+        int r;
+
+        assert(filename);
+        assert(lvalue);
+        assert(rvalue);
+
+        r = parse_boolean(rvalue);
+        if (r < 0) {
+                log_syntax(unit, LOG_ERR, filename, line, r, "Failed to parse Boot= parameter %s, ignoring: %m", rvalue);
+                return 0;
+        }
+
+        if (r > 0) {
+                if (settings->start_mode == START_PID2)
+                        goto conflict;
+
+                settings->start_mode = START_BOOT;
+        } else {
+                if (settings->start_mode == START_BOOT)
+                        goto conflict;
+
+                if (settings->start_mode < 0)
+                        settings->start_mode = START_PID1;
+        }
+
+        return 0;
+
+conflict:
+        log_syntax(unit, LOG_ERR, filename, line, r, "Conflicting Boot= or ProcessTwo= setting found. Ignoring.");
+        return 0;
+}
+
+int config_parse_pid2(
+                const char *unit,
+                const char *filename,
+                unsigned line,
+                const char *section,
+                unsigned section_line,
+                const char *lvalue,
+                int ltype,
+                const char *rvalue,
+                void *data,
+                void *userdata) {
+
+        Settings *settings = data;
+        int r;
+
+        assert(filename);
+        assert(lvalue);
+        assert(rvalue);
+
+        r = parse_boolean(rvalue);
+        if (r < 0) {
+                log_syntax(unit, LOG_ERR, filename, line, r, "Failed to parse ProcessTwo= parameter %s, ignoring: %m", rvalue);
+                return 0;
+        }
+
+        if (r > 0) {
+                if (settings->start_mode == START_BOOT)
+                        goto conflict;
+
+                settings->start_mode = START_PID2;
+        } else {
+                if (settings->start_mode == START_PID2)
+                        goto conflict;
+
+                if (settings->start_mode < 0)
+                        settings->start_mode = START_PID1;
+        }
+
+        return 0;
+
+conflict:
+        log_syntax(unit, LOG_ERR, filename, line, r, "Conflicting Boot= or ProcessTwo= setting found. Ignoring.");
+        return 0;
+}
+
+int config_parse_private_users(
+                const char *unit,
+                const char *filename,
+                unsigned line,
+                const char *section,
+                unsigned section_line,
+                const char *lvalue,
+                int ltype,
+                const char *rvalue,
+                void *data,
+                void *userdata) {
+
+        Settings *settings = data;
+        int r;
+
+        assert(filename);
+        assert(lvalue);
+        assert(rvalue);
+
+        r = parse_boolean(rvalue);
+        if (r == 0) {
+                /* no: User namespacing off */
+                settings->userns_mode = USER_NAMESPACE_NO;
+                settings->uid_shift = UID_INVALID;
+                settings->uid_range = UINT32_C(0x10000);
+        } else if (r > 0) {
+                /* yes: User namespacing on, UID range is read from root dir */
+                settings->userns_mode = USER_NAMESPACE_FIXED;
+                settings->uid_shift = UID_INVALID;
+                settings->uid_range = UINT32_C(0x10000);
+        } else if (streq(rvalue, "pick")) {
+                /* pick: User namespacing on, UID range is picked randomly */
+                settings->userns_mode = USER_NAMESPACE_PICK;
+                settings->uid_shift = UID_INVALID;
+                settings->uid_range = UINT32_C(0x10000);
+        } else {
+                const char *range, *shift;
+                uid_t sh, rn;
+
+                /* anything else: User namespacing on, UID range is explicitly configured */
+
+                range = strchr(rvalue, ':');
+                if (range) {
+                        shift = strndupa(rvalue, range - rvalue);
+                        range++;
+
+                        r = safe_atou32(range, &rn);
+                        if (r < 0 || rn <= 0) {
+                                log_syntax(unit, LOG_ERR, filename, line, r, "UID/GID range invalid, ignoring: %s", range);
+                                return 0;
+                        }
+                } else {
+                        shift = rvalue;
+                        rn = UINT32_C(0x10000);
+                }
+
+                r = parse_uid(shift, &sh);
+                if (r < 0) {
+                        log_syntax(unit, LOG_ERR, filename, line, r, "UID/GID shift invalid, ignoring: %s", range);
+                        return 0;
+                }
+
+                settings->userns_mode = USER_NAMESPACE_FIXED;
+                settings->uid_shift = sh;
+                settings->uid_range = rn;
+        }
+
+        return 0;
+}
diff --git a/src/systemd-nspawn/nspawn-settings.h b/src/systemd-nspawn/nspawn-settings.h
new file mode 100644
index 0000000000..5274daf80d
--- /dev/null
+++ b/src/systemd-nspawn/nspawn-settings.h
@@ -0,0 +1,119 @@
+#pragma once
+
+/***
+  This file is part of systemd.
+
+  Copyright 2015 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <stdio.h>
+
+#include "systemd-basic/macro.h"
+
+#include "nspawn-expose-ports.h"
+#include "nspawn-mount.h"
+
+typedef enum StartMode {
+        START_PID1, /* Run parameters as command line as process 1 */
+        START_PID2, /* Use stub init process as PID 1, run parameters as command line as process 2 */
+        START_BOOT, /* Search for init system, pass arguments as parameters */
+        _START_MODE_MAX,
+        _START_MODE_INVALID = -1
+} StartMode;
+
+typedef enum UserNamespaceMode {
+        USER_NAMESPACE_NO,
+        USER_NAMESPACE_FIXED,
+        USER_NAMESPACE_PICK,
+        _USER_NAMESPACE_MODE_MAX,
+        _USER_NAMESPACE_MODE_INVALID = -1,
+} UserNamespaceMode;
+
+typedef enum SettingsMask {
+        SETTING_START_MODE        = 1 << 0,
+        SETTING_ENVIRONMENT       = 1 << 1,
+        SETTING_USER              = 1 << 2,
+        SETTING_CAPABILITY        = 1 << 3,
+        SETTING_KILL_SIGNAL       = 1 << 4,
+        SETTING_PERSONALITY       = 1 << 5,
+        SETTING_MACHINE_ID        = 1 << 6,
+        SETTING_NETWORK           = 1 << 7,
+        SETTING_EXPOSE_PORTS      = 1 << 8,
+        SETTING_READ_ONLY         = 1 << 9,
+        SETTING_VOLATILE_MODE     = 1 << 10,
+        SETTING_CUSTOM_MOUNTS     = 1 << 11,
+        SETTING_WORKING_DIRECTORY = 1 << 12,
+        SETTING_USERNS            = 1 << 13,
+        SETTING_NOTIFY_READY      = 1 << 14,
+        _SETTINGS_MASK_ALL        = (1 << 15) -1
+} SettingsMask;
+
+typedef struct Settings {
+        /* [Run] */
+        StartMode start_mode;
+        char **parameters;
+        char **environment;
+        char *user;
+        uint64_t capability;
+        uint64_t drop_capability;
+        int kill_signal;
+        unsigned long personality;
+        sd_id128_t machine_id;
+        char *working_directory;
+        UserNamespaceMode userns_mode;
+        uid_t uid_shift, uid_range;
+        bool notify_ready;
+
+        /* [Image] */
+        int read_only;
+        VolatileMode volatile_mode;
+        CustomMount *custom_mounts;
+        unsigned n_custom_mounts;
+        int userns_chown;
+
+        /* [Network] */
+        int private_network;
+        int network_veth;
+        char *network_bridge;
+        char *network_zone;
+        char **network_interfaces;
+        char **network_macvlan;
+        char **network_ipvlan;
+        char **network_veth_extra;
+        ExposePort *expose_ports;
+} Settings;
+
+int settings_load(FILE *f, const char *path, Settings **ret);
+Settings* settings_free(Settings *s);
+
+bool settings_network_veth(Settings *s);
+bool settings_private_network(Settings *s);
+
+DEFINE_TRIVIAL_CLEANUP_FUNC(Settings*, settings_free);
+
+const struct ConfigPerfItem* nspawn_gperf_lookup(const char *key, unsigned length);
+
+int config_parse_capability(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
+int config_parse_id128(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
+int config_parse_expose_port(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
+int config_parse_volatile_mode(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
+int config_parse_bind(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
+int config_parse_tmpfs(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
+int config_parse_veth_extra(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
+int config_parse_network_zone(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
+int config_parse_boot(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
+int config_parse_pid2(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
+int config_parse_private_users(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
diff --git a/src/systemd-nspawn/nspawn-setuid.c b/src/systemd-nspawn/nspawn-setuid.c
new file mode 100644
index 0000000000..129d3acc5f
--- /dev/null
+++ b/src/systemd-nspawn/nspawn-setuid.c
@@ -0,0 +1,271 @@
+/***
+  This file is part of systemd.
+
+  Copyright 2015 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <grp.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "systemd-basic/alloc-util.h"
+#include "systemd-basic/fd-util.h"
+#include "systemd-basic/mkdir.h"
+#include "systemd-basic/process-util.h"
+#include "systemd-basic/signal-util.h"
+#include "systemd-basic/string-util.h"
+#include "systemd-basic/user-util.h"
+#include "systemd-basic/util.h"
+
+#include "nspawn-setuid.h"
+
+static int spawn_getent(const char *database, const char *key, pid_t *rpid) {
+        int pipe_fds[2];
+        pid_t pid;
+
+        assert(database);
+        assert(key);
+        assert(rpid);
+
+        if (pipe2(pipe_fds, O_CLOEXEC) < 0)
+                return log_error_errno(errno, "Failed to allocate pipe: %m");
+
+        pid = fork();
+        if (pid < 0)
+                return log_error_errno(errno, "Failed to fork getent child: %m");
+        else if (pid == 0) {
+                int nullfd;
+                char *empty_env = NULL;
+
+                if (dup3(pipe_fds[1], STDOUT_FILENO, 0) < 0)
+                        _exit(EXIT_FAILURE);
+
+                if (pipe_fds[0] > 2)
+                        safe_close(pipe_fds[0]);
+                if (pipe_fds[1] > 2)
+                        safe_close(pipe_fds[1]);
+
+                nullfd = open("/dev/null", O_RDWR);
+                if (nullfd < 0)
+                        _exit(EXIT_FAILURE);
+
+                if (dup3(nullfd, STDIN_FILENO, 0) < 0)
+                        _exit(EXIT_FAILURE);
+
+                if (dup3(nullfd, STDERR_FILENO, 0) < 0)
+                        _exit(EXIT_FAILURE);
+
+                if (nullfd > 2)
+                        safe_close(nullfd);
+
+                (void) reset_all_signal_handlers();
+                (void) reset_signal_mask();
+                close_all_fds(NULL, 0);
+
+                execle("/usr/bin/getent", "getent", database, key, NULL, &empty_env);
+                execle("/bin/getent", "getent", database, key, NULL, &empty_env);
+                _exit(EXIT_FAILURE);
+        }
+
+        pipe_fds[1] = safe_close(pipe_fds[1]);
+
+        *rpid = pid;
+
+        return pipe_fds[0];
+}
+
+int change_uid_gid(const char *user, char **_home) {
+        char line[LINE_MAX], *x, *u, *g, *h;
+        const char *word, *state;
+        _cleanup_free_ uid_t *uids = NULL;
+        _cleanup_free_ char *home = NULL;
+        _cleanup_fclose_ FILE *f = NULL;
+        _cleanup_close_ int fd = -1;
+        unsigned n_uids = 0;
+        size_t sz = 0, l;
+        uid_t uid;
+        gid_t gid;
+        pid_t pid;
+        int r;
+
+        assert(_home);
+
+        if (!user || streq(user, "root") || streq(user, "0")) {
+                /* Reset everything fully to 0, just in case */
+
+                r = reset_uid_gid();
+                if (r < 0)
+                        return log_error_errno(r, "Failed to become root: %m");
+
+                *_home = NULL;
+                return 0;
+        }
+
+        /* First, get user credentials */
+        fd = spawn_getent("passwd", user, &pid);
+        if (fd < 0)
+                return fd;
+
+        f = fdopen(fd, "r");
+        if (!f)
+                return log_oom();
+        fd = -1;
+
+        if (!fgets(line, sizeof(line), f)) {
+                if (!ferror(f)) {
+                        log_error("Failed to resolve user %s.", user);
+                        return -ESRCH;
+                }
+
+                return log_error_errno(errno, "Failed to read from getent: %m");
+        }
+
+        truncate_nl(line);
+
+        wait_for_terminate_and_warn("getent passwd", pid, true);
+
+        x = strchr(line, ':');
+        if (!x) {
+                log_error("/etc/passwd entry has invalid user field.");
+                return -EIO;
+        }
+
+        u = strchr(x+1, ':');
+        if (!u) {
+                log_error("/etc/passwd entry has invalid password field.");
+                return -EIO;
+        }
+
+        u++;
+        g = strchr(u, ':');
+        if (!g) {
+                log_error("/etc/passwd entry has invalid UID field.");
+                return -EIO;
+        }
+
+        *g = 0;
+        g++;
+        x = strchr(g, ':');
+        if (!x) {
+                log_error("/etc/passwd entry has invalid GID field.");
+                return -EIO;
+        }
+
+        *x = 0;
+        h = strchr(x+1, ':');
+        if (!h) {
+                log_error("/etc/passwd entry has invalid GECOS field.");
+                return -EIO;
+        }
+
+        h++;
+        x = strchr(h, ':');
+        if (!x) {
+                log_error("/etc/passwd entry has invalid home directory field.");
+                return -EIO;
+        }
+
+        *x = 0;
+
+        r = parse_uid(u, &uid);
+        if (r < 0) {
+                log_error("Failed to parse UID of user.");
+                return -EIO;
+        }
+
+        r = parse_gid(g, &gid);
+        if (r < 0) {
+                log_error("Failed to parse GID of user.");
+                return -EIO;
+        }
+
+        home = strdup(h);
+        if (!home)
+                return log_oom();
+
+        /* Second, get group memberships */
+        fd = spawn_getent("initgroups", user, &pid);
+        if (fd < 0)
+                return fd;
+
+        fclose(f);
+        f = fdopen(fd, "r");
+        if (!f)
+                return log_oom();
+        fd = -1;
+
+        if (!fgets(line, sizeof(line), f)) {
+                if (!ferror(f)) {
+                        log_error("Failed to resolve user %s.", user);
+                        return -ESRCH;
+                }
+
+                return log_error_errno(errno, "Failed to read from getent: %m");
+        }
+
+        truncate_nl(line);
+
+        wait_for_terminate_and_warn("getent initgroups", pid, true);
+
+        /* Skip over the username and subsequent separator whitespace */
+        x = line;
+        x += strcspn(x, WHITESPACE);
+        x += strspn(x, WHITESPACE);
+
+        FOREACH_WORD(word, l, x, state) {
+                char c[l+1];
+
+                memcpy(c, word, l);
+                c[l] = 0;
+
+                if (!GREEDY_REALLOC(uids, sz, n_uids+1))
+                        return log_oom();
+
+                r = parse_uid(c, &uids[n_uids++]);
+                if (r < 0) {
+                        log_error("Failed to parse group data from getent.");
+                        return -EIO;
+                }
+        }
+
+        r = mkdir_parents(home, 0775);
+        if (r < 0)
+                return log_error_errno(r, "Failed to make home root directory: %m");
+
+        r = mkdir_safe(home, 0755, uid, gid);
+        if (r < 0 && r != -EEXIST)
+                return log_error_errno(r, "Failed to make home directory: %m");
+
+        (void) fchown(STDIN_FILENO, uid, gid);
+        (void) fchown(STDOUT_FILENO, uid, gid);
+        (void) fchown(STDERR_FILENO, uid, gid);
+
+        if (setgroups(n_uids, uids) < 0)
+                return log_error_errno(errno, "Failed to set auxiliary groups: %m");
+
+        if (setresgid(gid, gid, gid) < 0)
+                return log_error_errno(errno, "setresgid() failed: %m");
+
+        if (setresuid(uid, uid, uid) < 0)
+                return log_error_errno(errno, "setresuid() failed: %m");
+
+        if (_home) {
+                *_home = home;
+                home = NULL;
+        }
+
+        return 0;
+}
diff --git a/src/systemd-nspawn/nspawn-setuid.h b/src/systemd-nspawn/nspawn-setuid.h
new file mode 100644
index 0000000000..b4968ba1fc
--- /dev/null
+++ b/src/systemd-nspawn/nspawn-setuid.h
@@ -0,0 +1,22 @@
+#pragma once
+
+/***
+  This file is part of systemd.
+
+  Copyright 2015 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+int change_uid_gid(const char *user, char **ret);
diff --git a/src/systemd-nspawn/nspawn-stub-pid1.c b/src/systemd-nspawn/nspawn-stub-pid1.c
new file mode 100644
index 0000000000..36d7bfc7c4
--- /dev/null
+++ b/src/systemd-nspawn/nspawn-stub-pid1.c
@@ -0,0 +1,171 @@
+/***
+  This file is part of systemd.
+
+  Copyright 2016 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <sys/reboot.h>
+#include <sys/unistd.h>
+#include <sys/wait.h>
+
+#include "systemd-basic/def.h"
+#include "systemd-basic/fd-util.h"
+#include "systemd-basic/log.h"
+#include "systemd-basic/process-util.h"
+#include "systemd-basic/signal-util.h"
+#include "systemd-basic/time-util.h"
+
+#include "nspawn-stub-pid1.h"
+
+int stub_pid1(void) {
+        enum {
+                STATE_RUNNING,
+                STATE_REBOOT,
+                STATE_POWEROFF,
+        } state = STATE_RUNNING;
+
+        sigset_t fullmask, oldmask, waitmask;
+        usec_t quit_usec = USEC_INFINITY;
+        pid_t pid;
+        int r;
+
+        /* Implements a stub PID 1, that reaps all processes and processes a couple of standard signals. This is useful
+         * for allowing arbitrary processes run in a container, and still have all zombies reaped. */
+
+        assert_se(sigfillset(&fullmask) >= 0);
+        assert_se(sigprocmask(SIG_BLOCK, &fullmask, &oldmask) >= 0);
+
+        pid = fork();
+        if (pid < 0)
+                return log_error_errno(errno, "Failed to fork child pid: %m");
+
+        if (pid == 0) {
+                /* Return in the child */
+                assert_se(sigprocmask(SIG_SETMASK, &oldmask, NULL) >= 0);
+                setsid();
+                return 0;
+        }
+
+        reset_all_signal_handlers();
+
+        log_close();
+        close_all_fds(NULL, 0);
+        log_open();
+
+        rename_process("STUBINIT");
+
+        assert_se(sigemptyset(&waitmask) >= 0);
+        assert_se(sigset_add_many(&waitmask,
+                                  SIGCHLD,          /* posix: process died */
+                                  SIGINT,           /* sysv: ctrl-alt-del */
+                                  SIGRTMIN+3,       /* systemd: halt */
+                                  SIGRTMIN+4,       /* systemd: poweroff */
+                                  SIGRTMIN+5,       /* systemd: reboot */
+                                  SIGRTMIN+6,       /* systemd: kexec */
+                                  SIGRTMIN+13,      /* systemd: halt */
+                                  SIGRTMIN+14,      /* systemd: poweroff */
+                                  SIGRTMIN+15,      /* systemd: reboot */
+                                  SIGRTMIN+16,      /* systemd: kexec */
+                                  -1) >= 0);
+
+        /* Note that we ignore SIGTERM (sysv's reexec), SIGHUP (reload), and all other signals here, since we don't
+         * support reexec/reloading in this stub process. */
+
+        for (;;) {
+                siginfo_t si;
+                usec_t current_usec;
+
+                si.si_pid = 0;
+                r = waitid(P_ALL, 0, &si, WEXITED|WNOHANG);
+                if (r < 0) {
+                        r = log_error_errno(errno, "Failed to reap children: %m");
+                        goto finish;
+                }
+
+                current_usec = now(CLOCK_MONOTONIC);
+
+                if (si.si_pid == pid || current_usec >= quit_usec) {
+
+                        /* The child we started ourselves died or we reached a timeout. */
+
+                        if (state == STATE_REBOOT) { /* dispatch a queued reboot */
+                                (void) reboot(RB_AUTOBOOT);
+                                r = log_error_errno(errno, "Failed to reboot: %m");
+                                goto finish;
+
+                        } else if (state == STATE_POWEROFF)
+                                (void) reboot(RB_POWER_OFF); /* if this fails, fall back to normal exit. */
+
+                        if (si.si_pid == pid && si.si_code == CLD_EXITED)
+                                r = si.si_status; /* pass on exit code */
+                        else
+                                r = 255; /* signal, coredump, timeout, … */
+
+                        goto finish;
+                }
+                if (si.si_pid != 0)
+                        /* We reaped something. Retry until there's nothing more to reap. */
+                        continue;
+
+                if (quit_usec == USEC_INFINITY)
+                        r = sigwaitinfo(&waitmask, &si);
+                else {
+                        struct timespec ts;
+                        r = sigtimedwait(&waitmask, &si, timespec_store(&ts, quit_usec - current_usec));
+                }
+                if (r < 0) {
+                        if (errno == EINTR) /* strace -p attach can result in EINTR, let's handle this nicely. */
+                                continue;
+                        if (errno == EAGAIN) /* timeout reached */
+                                continue;
+
+                        r = log_error_errno(errno, "Failed to wait for signal: %m");
+                        goto finish;
+                }
+
+                if (si.si_signo == SIGCHLD)
+                        continue; /* Let's reap this */
+
+                if (state != STATE_RUNNING)
+                        continue;
+
+                /* Would love to use a switch() statement here, but SIGRTMIN is actually a function call, not a
+                 * constant… */
+
+                if (si.si_signo == SIGRTMIN+3 ||
+                    si.si_signo == SIGRTMIN+4 ||
+                    si.si_signo == SIGRTMIN+13 ||
+                    si.si_signo == SIGRTMIN+14)
+
+                        state = STATE_POWEROFF;
+
+                else if (si.si_signo == SIGINT ||
+                         si.si_signo == SIGRTMIN+5 ||
+                         si.si_signo == SIGRTMIN+6 ||
+                         si.si_signo == SIGRTMIN+15 ||
+                         si.si_signo == SIGRTMIN+16)
+
+                        state = STATE_REBOOT;
+                else
+                        assert_not_reached("Got unexpected signal");
+
+                /* (void) kill_and_sigcont(pid, SIGTERM); */
+                quit_usec = now(CLOCK_MONOTONIC) + DEFAULT_TIMEOUT_USEC;
+        }
+
+finish:
+        _exit(r < 0 ? EXIT_FAILURE : r);
+}
diff --git a/src/systemd-nspawn/nspawn-stub-pid1.h b/src/systemd-nspawn/nspawn-stub-pid1.h
new file mode 100644
index 0000000000..36c1aaf5dd
--- /dev/null
+++ b/src/systemd-nspawn/nspawn-stub-pid1.h
@@ -0,0 +1,22 @@
+#pragma once
+
+/***
+  This file is part of systemd.
+
+  Copyright 2016 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+int stub_pid1(void);
diff --git a/src/systemd-nspawn/nspawn.c b/src/systemd-nspawn/nspawn.c
new file mode 100644
index 0000000000..5a3624fad1
--- /dev/null
+++ b/src/systemd-nspawn/nspawn.c
@@ -0,0 +1,4319 @@
+/***
+  This file is part of systemd.
+
+  Copyright 2010 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#ifdef HAVE_BLKID
+#include <blkid/blkid.h>
+#endif
+#include <errno.h>
+#include <getopt.h>
+#include <grp.h>
+#include <pwd.h>
+#include <sched.h>
+
+#include <linux/loop.h>
+#ifdef HAVE_SELINUX
+#include <selinux/selinux.h>
+#endif
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/file.h>
+#include <sys/mount.h>
+#include <sys/personality.h>
+#include <sys/prctl.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <systemd/sd-daemon.h>
+#include <systemd/sd-id128.h>
+
+#include "core/loopback-setup.h"
+#include "sd-id128/id128-util.h"
+#include "sd-netlink/netlink-util.h"
+#include "systemd-basic/alloc-util.h"
+#include "systemd-basic/barrier.h"
+#include "systemd-basic/btrfs-util.h"
+#include "systemd-basic/cap-list.h"
+#include "systemd-basic/capability-util.h"
+#include "systemd-basic/cgroup-util.h"
+#include "systemd-basic/copy.h"
+#include "systemd-basic/env-util.h"
+#include "systemd-basic/fd-util.h"
+#include "systemd-basic/fileio.h"
+#include "systemd-basic/formats-util.h"
+#include "systemd-basic/fs-util.h"
+#include "systemd-basic/hostname-util.h"
+#include "systemd-basic/log.h"
+#include "systemd-basic/macro.h"
+#include "systemd-basic/missing.h"
+#include "systemd-basic/mkdir.h"
+#include "systemd-basic/mount-util.h"
+#include "systemd-basic/parse-util.h"
+#include "systemd-basic/path-util.h"
+#include "systemd-basic/process-util.h"
+#include "systemd-basic/random-util.h"
+#include "systemd-basic/raw-clone.h"
+#include "systemd-basic/rm-rf.h"
+#include "systemd-basic/selinux-util.h"
+#include "systemd-basic/signal-util.h"
+#include "systemd-basic/socket-util.h"
+#include "systemd-basic/stat-util.h"
+#include "systemd-basic/stdio-util.h"
+#include "systemd-basic/string-util.h"
+#include "systemd-basic/strv.h"
+#include "systemd-basic/terminal-util.h"
+#include "systemd-basic/umask-util.h"
+#include "systemd-basic/user-util.h"
+#include "systemd-basic/util.h"
+#include "systemd-blkid/blkid-util.h"
+#include "systemd-shared/base-filesystem.h"
+#include "systemd-shared/dev-setup.h"
+#include "systemd-shared/fdset.h"
+#include "systemd-shared/gpt.h"
+#include "systemd-shared/machine-image.h"
+#include "systemd-shared/ptyfwd.h"
+#include "systemd-shared/udev-util.h"
+
+#include "nspawn-cgroup.h"
+#include "nspawn-expose-ports.h"
+#include "nspawn-mount.h"
+#include "nspawn-network.h"
+#include "nspawn-patch-uid.h"
+#include "nspawn-register.h"
+#include "nspawn-seccomp.h"
+#include "nspawn-settings.h"
+#include "nspawn-setuid.h"
+#include "nspawn-stub-pid1.h"
+
+/* Note that devpts's gid= parameter parses GIDs as signed values, hence we stay away from the upper half of the 32bit
+ * UID range here. We leave a bit of room at the lower end and a lot of room at the upper end, so that other subsystems
+ * may have their own allocation ranges too. */
+#define UID_SHIFT_PICK_MIN ((uid_t) UINT32_C(0x00080000))
+#define UID_SHIFT_PICK_MAX ((uid_t) UINT32_C(0x6FFF0000))
+
+/* nspawn is listening on the socket at the path in the constant nspawn_notify_socket_path
+ * nspawn_notify_socket_path is relative to the container
+ * the init process in the container pid can send messages to nspawn following the sd_notify(3) protocol */
+#define NSPAWN_NOTIFY_SOCKET_PATH "/run/systemd/nspawn/notify"
+
+typedef enum ContainerStatus {
+        CONTAINER_TERMINATED,
+        CONTAINER_REBOOTED
+} ContainerStatus;
+
+typedef enum LinkJournal {
+        LINK_NO,
+        LINK_AUTO,
+        LINK_HOST,
+        LINK_GUEST
+} LinkJournal;
+
+static char *arg_directory = NULL;
+static char *arg_template = NULL;
+static char *arg_chdir = NULL;
+static char *arg_user = NULL;
+static sd_id128_t arg_uuid = {};
+static char *arg_machine = NULL;
+static const char *arg_selinux_context = NULL;
+static const char *arg_selinux_apifs_context = NULL;
+static const char *arg_slice = NULL;
+static bool arg_private_network = false;
+static bool arg_read_only = false;
+static StartMode arg_start_mode = START_PID1;
+static bool arg_ephemeral = false;
+static LinkJournal arg_link_journal = LINK_AUTO;
+static bool arg_link_journal_try = false;
+static uint64_t arg_caps_retain =
+        (1ULL << CAP_AUDIT_CONTROL) |
+        (1ULL << CAP_AUDIT_WRITE) |
+        (1ULL << CAP_CHOWN) |
+        (1ULL << CAP_DAC_OVERRIDE) |
+        (1ULL << CAP_DAC_READ_SEARCH) |
+        (1ULL << CAP_FOWNER) |
+        (1ULL << CAP_FSETID) |
+        (1ULL << CAP_IPC_OWNER) |
+        (1ULL << CAP_KILL) |
+        (1ULL << CAP_LEASE) |
+        (1ULL << CAP_LINUX_IMMUTABLE) |
+        (1ULL << CAP_MKNOD) |
+        (1ULL << CAP_NET_BIND_SERVICE) |
+        (1ULL << CAP_NET_BROADCAST) |
+        (1ULL << CAP_NET_RAW) |
+        (1ULL << CAP_SETFCAP) |
+        (1ULL << CAP_SETGID) |
+        (1ULL << CAP_SETPCAP) |
+        (1ULL << CAP_SETUID) |
+        (1ULL << CAP_SYS_ADMIN) |
+        (1ULL << CAP_SYS_BOOT) |
+        (1ULL << CAP_SYS_CHROOT) |
+        (1ULL << CAP_SYS_NICE) |
+        (1ULL << CAP_SYS_PTRACE) |
+        (1ULL << CAP_SYS_RESOURCE) |
+        (1ULL << CAP_SYS_TTY_CONFIG);
+static CustomMount *arg_custom_mounts = NULL;
+static unsigned arg_n_custom_mounts = 0;
+static char **arg_setenv = NULL;
+static bool arg_quiet = false;
+static bool arg_register = true;
+static bool arg_keep_unit = false;
+static char **arg_network_interfaces = NULL;
+static char **arg_network_macvlan = NULL;
+static char **arg_network_ipvlan = NULL;
+static bool arg_network_veth = false;
+static char **arg_network_veth_extra = NULL;
+static char *arg_network_bridge = NULL;
+static char *arg_network_zone = NULL;
+static unsigned long arg_personality = PERSONALITY_INVALID;
+static char *arg_image = NULL;
+static VolatileMode arg_volatile_mode = VOLATILE_NO;
+static ExposePort *arg_expose_ports = NULL;
+static char **arg_property = NULL;
+static UserNamespaceMode arg_userns_mode = USER_NAMESPACE_NO;
+static uid_t arg_uid_shift = UID_INVALID, arg_uid_range = 0x10000U;
+static bool arg_userns_chown = false;
+static int arg_kill_signal = 0;
+static CGroupUnified arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_UNKNOWN;
+static SettingsMask arg_settings_mask = 0;
+static int arg_settings_trusted = -1;
+static char **arg_parameters = NULL;
+static const char *arg_container_service_name = "systemd-nspawn";
+static bool arg_notify_ready = false;
+static bool arg_use_cgns = true;
+static unsigned long arg_clone_ns_flags = CLONE_NEWIPC|CLONE_NEWPID|CLONE_NEWUTS;
+
+static void help(void) {
+        printf("%s [OPTIONS...] [PATH] [ARGUMENTS...]\n\n"
+               "Spawn a minimal namespace container for debugging, testing and building.\n\n"
+               "  -h --help                 Show this help\n"
+               "     --version              Print version string\n"
+               "  -q --quiet                Do not show status information\n"
+               "  -D --directory=PATH       Root directory for the container\n"
+               "     --template=PATH        Initialize root directory from template directory,\n"
+               "                            if missing\n"
+               "  -x --ephemeral            Run container with snapshot of root directory, and\n"
+               "                            remove it after exit\n"
+               "  -i --image=PATH           File system device or disk image for the container\n"
+               "  -a --as-pid2              Maintain a stub init as PID1, invoke binary as PID2\n"
+               "  -b --boot                 Boot up full system (i.e. invoke init)\n"
+               "     --chdir=PATH           Set working directory in the container\n"
+               "  -u --user=USER            Run the command under specified user or uid\n"
+               "  -M --machine=NAME         Set the machine name for the container\n"
+               "     --uuid=UUID            Set a specific machine UUID for the container\n"
+               "  -S --slice=SLICE          Place the container in the specified slice\n"
+               "     --property=NAME=VALUE  Set scope unit property\n"
+               "  -U --private-users=pick   Run within user namespace, autoselect UID/GID range\n"
+               "     --private-users[=UIDBASE[:NUIDS]]\n"
+               "                            Similar, but with user configured UID/GID range\n"
+               "     --private-users-chown  Adjust OS tree ownership to private UID/GID range\n"
+               "     --private-network      Disable network in container\n"
+               "     --network-interface=INTERFACE\n"
+               "                            Assign an existing network interface to the\n"
+               "                            container\n"
+               "     --network-macvlan=INTERFACE\n"
+               "                            Create a macvlan network interface based on an\n"
+               "                            existing network interface to the container\n"
+               "     --network-ipvlan=INTERFACE\n"
+               "                            Create a ipvlan network interface based on an\n"
+               "                            existing network interface to the container\n"
+               "  -n --network-veth         Add a virtual Ethernet connection between host\n"
+               "                            and container\n"
+               "     --network-veth-extra=HOSTIF[:CONTAINERIF]\n"
+               "                            Add an additional virtual Ethernet link between\n"
+               "                            host and container\n"
+               "     --network-bridge=INTERFACE\n"
+               "                            Add a virtual Ethernet connection to the container\n"
+               "                            and attach it to an existing bridge on the host\n"
+               "     --network-zone=NAME    Similar, but attach the new interface to an\n"
+               "                            an automatically managed bridge interface\n"
+               "  -p --port=[PROTOCOL:]HOSTPORT[:CONTAINERPORT]\n"
+               "                            Expose a container IP port on the host\n"
+               "  -Z --selinux-context=SECLABEL\n"
+               "                            Set the SELinux security context to be used by\n"
+               "                            processes in the container\n"
+               "  -L --selinux-apifs-context=SECLABEL\n"
+               "                            Set the SELinux security context to be used by\n"
+               "                            API/tmpfs file systems in the container\n"
+               "     --capability=CAP       In addition to the default, retain specified\n"
+               "                            capability\n"
+               "     --drop-capability=CAP  Drop the specified capability from the default set\n"
+               "     --kill-signal=SIGNAL   Select signal to use for shutting down PID 1\n"
+               "     --link-journal=MODE    Link up guest journal, one of no, auto, guest, \n"
+               "                            host, try-guest, try-host\n"
+               "  -j                        Equivalent to --link-journal=try-guest\n"
+               "     --read-only            Mount the root directory read-only\n"
+               "     --bind=PATH[:PATH[:OPTIONS]]\n"
+               "                            Bind mount a file or directory from the host into\n"
+               "                            the container\n"
+               "     --bind-ro=PATH[:PATH[:OPTIONS]\n"
+               "                            Similar, but creates a read-only bind mount\n"
+               "     --tmpfs=PATH:[OPTIONS] Mount an empty tmpfs to the specified directory\n"
+               "     --overlay=PATH[:PATH...]:PATH\n"
+               "                            Create an overlay mount from the host to \n"
+               "                            the container\n"
+               "     --overlay-ro=PATH[:PATH...]:PATH\n"
+               "                            Similar, but creates a read-only overlay mount\n"
+               "  -E --setenv=NAME=VALUE    Pass an environment variable to PID 1\n"
+               "     --register=BOOLEAN     Register container as machine\n"
+               "     --keep-unit            Do not register a scope for the machine, reuse\n"
+               "                            the service unit nspawn is running in\n"
+               "     --volatile[=MODE]      Run the system in volatile mode\n"
+               "     --settings=BOOLEAN     Load additional settings from .nspawn file\n"
+               "     --notify-ready=BOOLEAN Receive notifications from the child init process\n"
+               , program_invocation_short_name);
+}
+
+static int custom_mounts_prepare(void) {
+        unsigned i;
+        int r;
+
+        /* Ensure the mounts are applied prefix first. */
+        qsort_safe(arg_custom_mounts, arg_n_custom_mounts, sizeof(CustomMount), custom_mount_compare);
+
+        /* Allocate working directories for the overlay file systems that need it */
+        for (i = 0; i < arg_n_custom_mounts; i++) {
+                CustomMount *m = &arg_custom_mounts[i];
+
+                if (path_equal(m->destination, "/") && arg_userns_mode != USER_NAMESPACE_NO) {
+
+                        if (arg_userns_chown) {
+                                log_error("--private-users-chown may not be combined with custom root mounts.");
+                                return -EINVAL;
+                        } else if (arg_uid_shift == UID_INVALID) {
+                                log_error("--private-users with automatic UID shift may not be combined with custom root mounts.");
+                                return -EINVAL;
+                        }
+                }
+
+                if (m->type != CUSTOM_MOUNT_OVERLAY)
+                        continue;
+
+                if (m->work_dir)
+                        continue;
+
+                if (m->read_only)
+                        continue;
+
+                r = tempfn_random(m->source, NULL, &m->work_dir);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to generate work directory from %s: %m", m->source);
+        }
+
+        return 0;
+}
+
+static int detect_unified_cgroup_hierarchy(const char *directory) {
+        const char *e;
+        int r, all_unified, systemd_unified;
+
+        /* Allow the user to control whether the unified hierarchy is used */
+        e = getenv("UNIFIED_CGROUP_HIERARCHY");
+        if (e) {
+                r = parse_boolean(e);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to parse $UNIFIED_CGROUP_HIERARCHY.");
+                if (r > 0)
+                        arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_ALL;
+                else
+                        arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_NONE;
+
+                return 0;
+        }
+
+        all_unified = cg_all_unified();
+        systemd_unified = cg_unified(SYSTEMD_CGROUP_CONTROLLER);
+
+        if (all_unified < 0 || systemd_unified < 0)
+                return log_error_errno(all_unified < 0 ? all_unified : systemd_unified,
+                                       "Failed to determine whether the unified cgroups hierarchy is used: %m");
+
+        /* Otherwise inherit the default from the host system */
+        if (all_unified > 0) {
+                /* Unified cgroup hierarchy support was added in 230. Unfortunately the detection
+                 * routine only detects 231, so we'll have a false negative here for 230. */
+                r = systemd_installation_has_version(directory, 230);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to determine systemd version in container: %m");
+                if (r > 0)
+                        arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_ALL;
+                else
+                        arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_NONE;
+        } else if (systemd_unified > 0) {
+                /* Mixed cgroup hierarchy support was added in 232 */
+                r = systemd_installation_has_version(directory, 232);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to determine systemd version in container: %m");
+                if (r > 0)
+                        arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_SYSTEMD;
+                else
+                        arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_NONE;
+        } else
+                arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_NONE;
+
+        return 0;
+}
+
+static void parse_share_ns_env(const char *name, unsigned long ns_flag) {
+        int r;
+
+        r = getenv_bool(name);
+        if (r == -ENXIO)
+                return;
+        if (r < 0)
+                log_warning_errno(r, "Failed to parse %s from environment, defaulting to false.", name);
+        arg_clone_ns_flags = (arg_clone_ns_flags & ~ns_flag) | (r > 0 ? 0 : ns_flag);
+}
+
+static int parse_argv(int argc, char *argv[]) {
+
+        enum {
+                ARG_VERSION = 0x100,
+                ARG_PRIVATE_NETWORK,
+                ARG_UUID,
+                ARG_READ_ONLY,
+                ARG_CAPABILITY,
+                ARG_DROP_CAPABILITY,
+                ARG_LINK_JOURNAL,
+                ARG_BIND,
+                ARG_BIND_RO,
+                ARG_TMPFS,
+                ARG_OVERLAY,
+                ARG_OVERLAY_RO,
+                ARG_SHARE_SYSTEM,
+                ARG_REGISTER,
+                ARG_KEEP_UNIT,
+                ARG_NETWORK_INTERFACE,
+                ARG_NETWORK_MACVLAN,
+                ARG_NETWORK_IPVLAN,
+                ARG_NETWORK_BRIDGE,
+                ARG_NETWORK_ZONE,
+                ARG_NETWORK_VETH_EXTRA,
+                ARG_PERSONALITY,
+                ARG_VOLATILE,
+                ARG_TEMPLATE,
+                ARG_PROPERTY,
+                ARG_PRIVATE_USERS,
+                ARG_KILL_SIGNAL,
+                ARG_SETTINGS,
+                ARG_CHDIR,
+                ARG_PRIVATE_USERS_CHOWN,
+                ARG_NOTIFY_READY,
+        };
+
+        static const struct option options[] = {
+                { "help",                  no_argument,       NULL, 'h'                     },
+                { "version",               no_argument,       NULL, ARG_VERSION             },
+                { "directory",             required_argument, NULL, 'D'                     },
+                { "template",              required_argument, NULL, ARG_TEMPLATE            },
+                { "ephemeral",             no_argument,       NULL, 'x'                     },
+                { "user",                  required_argument, NULL, 'u'                     },
+                { "private-network",       no_argument,       NULL, ARG_PRIVATE_NETWORK     },
+                { "as-pid2",               no_argument,       NULL, 'a'                     },
+                { "boot",                  no_argument,       NULL, 'b'                     },
+                { "uuid",                  required_argument, NULL, ARG_UUID                },
+                { "read-only",             no_argument,       NULL, ARG_READ_ONLY           },
+                { "capability",            required_argument, NULL, ARG_CAPABILITY          },
+                { "drop-capability",       required_argument, NULL, ARG_DROP_CAPABILITY     },
+                { "link-journal",          required_argument, NULL, ARG_LINK_JOURNAL        },
+                { "bind",                  required_argument, NULL, ARG_BIND                },
+                { "bind-ro",               required_argument, NULL, ARG_BIND_RO             },
+                { "tmpfs",                 required_argument, NULL, ARG_TMPFS               },
+                { "overlay",               required_argument, NULL, ARG_OVERLAY             },
+                { "overlay-ro",            required_argument, NULL, ARG_OVERLAY_RO          },
+                { "machine",               required_argument, NULL, 'M'                     },
+                { "slice",                 required_argument, NULL, 'S'                     },
+                { "setenv",                required_argument, NULL, 'E'                     },
+                { "selinux-context",       required_argument, NULL, 'Z'                     },
+                { "selinux-apifs-context", required_argument, NULL, 'L'                     },
+                { "quiet",                 no_argument,       NULL, 'q'                     },
+                { "share-system",          no_argument,       NULL, ARG_SHARE_SYSTEM        }, /* not documented */
+                { "register",              required_argument, NULL, ARG_REGISTER            },
+                { "keep-unit",             no_argument,       NULL, ARG_KEEP_UNIT           },
+                { "network-interface",     required_argument, NULL, ARG_NETWORK_INTERFACE   },
+                { "network-macvlan",       required_argument, NULL, ARG_NETWORK_MACVLAN     },
+                { "network-ipvlan",        required_argument, NULL, ARG_NETWORK_IPVLAN      },
+                { "network-veth",          no_argument,       NULL, 'n'                     },
+                { "network-veth-extra",    required_argument, NULL, ARG_NETWORK_VETH_EXTRA  },
+                { "network-bridge",        required_argument, NULL, ARG_NETWORK_BRIDGE      },
+                { "network-zone",          required_argument, NULL, ARG_NETWORK_ZONE        },
+                { "personality",           required_argument, NULL, ARG_PERSONALITY         },
+                { "image",                 required_argument, NULL, 'i'                     },
+                { "volatile",              optional_argument, NULL, ARG_VOLATILE            },
+                { "port",                  required_argument, NULL, 'p'                     },
+                { "property",              required_argument, NULL, ARG_PROPERTY            },
+                { "private-users",         optional_argument, NULL, ARG_PRIVATE_USERS       },
+                { "private-users-chown",   optional_argument, NULL, ARG_PRIVATE_USERS_CHOWN },
+                { "kill-signal",           required_argument, NULL, ARG_KILL_SIGNAL         },
+                { "settings",              required_argument, NULL, ARG_SETTINGS            },
+                { "chdir",                 required_argument, NULL, ARG_CHDIR               },
+                { "notify-ready",          required_argument, NULL, ARG_NOTIFY_READY        },
+                {}
+        };
+
+        int c, r;
+        const char *p, *e;
+        uint64_t plus = 0, minus = 0;
+        bool mask_all_settings = false, mask_no_settings = false;
+
+        assert(argc >= 0);
+        assert(argv);
+
+        while ((c = getopt_long(argc, argv, "+hD:u:abL:M:jS:Z:qi:xp:nU", options, NULL)) >= 0)
+
+                switch (c) {
+
+                case 'h':
+                        help();
+                        return 0;
+
+                case ARG_VERSION:
+                        return version();
+
+                case 'D':
+                        r = parse_path_argument_and_warn(optarg, false, &arg_directory);
+                        if (r < 0)
+                                return r;
+                        break;
+
+                case ARG_TEMPLATE:
+                        r = parse_path_argument_and_warn(optarg, false, &arg_template);
+                        if (r < 0)
+                                return r;
+                        break;
+
+                case 'i':
+                        r = parse_path_argument_and_warn(optarg, false, &arg_image);
+                        if (r < 0)
+                                return r;
+                        break;
+
+                case 'x':
+                        arg_ephemeral = true;
+                        break;
+
+                case 'u':
+                        r = free_and_strdup(&arg_user, optarg);
+                        if (r < 0)
+                                return log_oom();
+
+                        arg_settings_mask |= SETTING_USER;
+                        break;
+
+                case ARG_NETWORK_ZONE: {
+                        char *j;
+
+                        j = strappend("vz-", optarg);
+                        if (!j)
+                                return log_oom();
+
+                        if (!ifname_valid(j)) {
+                                log_error("Network zone name not valid: %s", j);
+                                free(j);
+                                return -EINVAL;
+                        }
+
+                        free(arg_network_zone);
+                        arg_network_zone = j;
+
+                        arg_network_veth = true;
+                        arg_private_network = true;
+                        arg_settings_mask |= SETTING_NETWORK;
+                        break;
+                }
+
+                case ARG_NETWORK_BRIDGE:
+
+                        if (!ifname_valid(optarg)) {
+                                log_error("Bridge interface name not valid: %s", optarg);
+                                return -EINVAL;
+                        }
+
+                        r = free_and_strdup(&arg_network_bridge, optarg);
+                        if (r < 0)
+                                return log_oom();
+
+                        /* fall through */
+
+                case 'n':
+                        arg_network_veth = true;
+                        arg_private_network = true;
+                        arg_settings_mask |= SETTING_NETWORK;
+                        break;
+
+                case ARG_NETWORK_VETH_EXTRA:
+                        r = veth_extra_parse(&arg_network_veth_extra, optarg);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to parse --network-veth-extra= parameter: %s", optarg);
+
+                        arg_private_network = true;
+                        arg_settings_mask |= SETTING_NETWORK;
+                        break;
+
+                case ARG_NETWORK_INTERFACE:
+
+                        if (!ifname_valid(optarg)) {
+                                log_error("Network interface name not valid: %s", optarg);
+                                return -EINVAL;
+                        }
+
+                        if (strv_extend(&arg_network_interfaces, optarg) < 0)
+                                return log_oom();
+
+                        arg_private_network = true;
+                        arg_settings_mask |= SETTING_NETWORK;
+                        break;
+
+                case ARG_NETWORK_MACVLAN:
+
+                        if (!ifname_valid(optarg)) {
+                                log_error("MACVLAN network interface name not valid: %s", optarg);
+                                return -EINVAL;
+                        }
+
+                        if (strv_extend(&arg_network_macvlan, optarg) < 0)
+                                return log_oom();
+
+                        arg_private_network = true;
+                        arg_settings_mask |= SETTING_NETWORK;
+                        break;
+
+                case ARG_NETWORK_IPVLAN:
+
+                        if (!ifname_valid(optarg)) {
+                                log_error("IPVLAN network interface name not valid: %s", optarg);
+                                return -EINVAL;
+                        }
+
+                        if (strv_extend(&arg_network_ipvlan, optarg) < 0)
+                                return log_oom();
+
+                        /* fall through */
+
+                case ARG_PRIVATE_NETWORK:
+                        arg_private_network = true;
+                        arg_settings_mask |= SETTING_NETWORK;
+                        break;
+
+                case 'b':
+                        if (arg_start_mode == START_PID2) {
+                                log_error("--boot and --as-pid2 may not be combined.");
+                                return -EINVAL;
+                        }
+
+                        arg_start_mode = START_BOOT;
+                        arg_settings_mask |= SETTING_START_MODE;
+                        break;
+
+                case 'a':
+                        if (arg_start_mode == START_BOOT) {
+                                log_error("--boot and --as-pid2 may not be combined.");
+                                return -EINVAL;
+                        }
+
+                        arg_start_mode = START_PID2;
+                        arg_settings_mask |= SETTING_START_MODE;
+                        break;
+
+                case ARG_UUID:
+                        r = sd_id128_from_string(optarg, &arg_uuid);
+                        if (r < 0)
+                                return log_error_errno(r, "Invalid UUID: %s", optarg);
+
+                        if (sd_id128_is_null(arg_uuid)) {
+                                log_error("Machine UUID may not be all zeroes.");
+                                return -EINVAL;
+                        }
+
+                        arg_settings_mask |= SETTING_MACHINE_ID;
+                        break;
+
+                case 'S':
+                        arg_slice = optarg;
+                        break;
+
+                case 'M':
+                        if (isempty(optarg))
+                                arg_machine = mfree(arg_machine);
+                        else {
+                                if (!machine_name_is_valid(optarg)) {
+                                        log_error("Invalid machine name: %s", optarg);
+                                        return -EINVAL;
+                                }
+
+                                r = free_and_strdup(&arg_machine, optarg);
+                                if (r < 0)
+                                        return log_oom();
+
+                                break;
+                        }
+
+                case 'Z':
+                        arg_selinux_context = optarg;
+                        break;
+
+                case 'L':
+                        arg_selinux_apifs_context = optarg;
+                        break;
+
+                case ARG_READ_ONLY:
+                        arg_read_only = true;
+                        arg_settings_mask |= SETTING_READ_ONLY;
+                        break;
+
+                case ARG_CAPABILITY:
+                case ARG_DROP_CAPABILITY: {
+                        p = optarg;
+                        for (;;) {
+                                _cleanup_free_ char *t = NULL;
+
+                                r = extract_first_word(&p, &t, ",", 0);
+                                if (r < 0)
+                                        return log_error_errno(r, "Failed to parse capability %s.", t);
+
+                                if (r == 0)
+                                        break;
+
+                                if (streq(t, "all")) {
+                                        if (c == ARG_CAPABILITY)
+                                                plus = (uint64_t) -1;
+                                        else
+                                                minus = (uint64_t) -1;
+                                } else {
+                                        int cap;
+
+                                        cap = capability_from_name(t);
+                                        if (cap < 0) {
+                                                log_error("Failed to parse capability %s.", t);
+                                                return -EINVAL;
+                                        }
+
+                                        if (c == ARG_CAPABILITY)
+                                                plus |= 1ULL << (uint64_t) cap;
+                                        else
+                                                minus |= 1ULL << (uint64_t) cap;
+                                }
+                        }
+
+                        arg_settings_mask |= SETTING_CAPABILITY;
+                        break;
+                }
+
+                case 'j':
+                        arg_link_journal = LINK_GUEST;
+                        arg_link_journal_try = true;
+                        break;
+
+                case ARG_LINK_JOURNAL:
+                        if (streq(optarg, "auto")) {
+                                arg_link_journal = LINK_AUTO;
+                                arg_link_journal_try = false;
+                        } else if (streq(optarg, "no")) {
+                                arg_link_journal = LINK_NO;
+                                arg_link_journal_try = false;
+                        } else if (streq(optarg, "guest")) {
+                                arg_link_journal = LINK_GUEST;
+                                arg_link_journal_try = false;
+                        } else if (streq(optarg, "host")) {
+                                arg_link_journal = LINK_HOST;
+                                arg_link_journal_try = false;
+                        } else if (streq(optarg, "try-guest")) {
+                                arg_link_journal = LINK_GUEST;
+                                arg_link_journal_try = true;
+                        } else if (streq(optarg, "try-host")) {
+                                arg_link_journal = LINK_HOST;
+                                arg_link_journal_try = true;
+                        } else {
+                                log_error("Failed to parse link journal mode %s", optarg);
+                                return -EINVAL;
+                        }
+
+                        break;
+
+                case ARG_BIND:
+                case ARG_BIND_RO:
+                        r = bind_mount_parse(&arg_custom_mounts, &arg_n_custom_mounts, optarg, c == ARG_BIND_RO);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to parse --bind(-ro)= argument %s: %m", optarg);
+
+                        arg_settings_mask |= SETTING_CUSTOM_MOUNTS;
+                        break;
+
+                case ARG_TMPFS:
+                        r = tmpfs_mount_parse(&arg_custom_mounts, &arg_n_custom_mounts, optarg);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to parse --tmpfs= argument %s: %m", optarg);
+
+                        arg_settings_mask |= SETTING_CUSTOM_MOUNTS;
+                        break;
+
+                case ARG_OVERLAY:
+                case ARG_OVERLAY_RO: {
+                        _cleanup_free_ char *upper = NULL, *destination = NULL;
+                        _cleanup_strv_free_ char **lower = NULL;
+                        CustomMount *m;
+                        unsigned n = 0;
+                        char **i;
+
+                        r = strv_split_extract(&lower, optarg, ":", EXTRACT_DONT_COALESCE_SEPARATORS);
+                        if (r == -ENOMEM)
+                                return log_oom();
+                        else if (r < 0) {
+                                log_error("Invalid overlay specification: %s", optarg);
+                                return r;
+                        }
+
+                        STRV_FOREACH(i, lower) {
+                                if (!path_is_absolute(*i)) {
+                                        log_error("Overlay path %s is not absolute.", *i);
+                                        return -EINVAL;
+                                }
+
+                                n++;
+                        }
+
+                        if (n < 2) {
+                                log_error("--overlay= needs at least two colon-separated directories specified.");
+                                return -EINVAL;
+                        }
+
+                        if (n == 2) {
+                                /* If two parameters are specified,
+                                 * the first one is the lower, the
+                                 * second one the upper directory. And
+                                 * we'll also define the destination
+                                 * mount point the same as the upper. */
+                                upper = lower[1];
+                                lower[1] = NULL;
+
+                                destination = strdup(upper);
+                                if (!destination)
+                                        return log_oom();
+
+                        } else {
+                                upper = lower[n - 2];
+                                destination = lower[n - 1];
+                                lower[n - 2] = NULL;
+                        }
+
+                        m = custom_mount_add(&arg_custom_mounts, &arg_n_custom_mounts, CUSTOM_MOUNT_OVERLAY);
+                        if (!m)
+                                return log_oom();
+
+                        m->destination = destination;
+                        m->source = upper;
+                        m->lower = lower;
+                        m->read_only = c == ARG_OVERLAY_RO;
+
+                        upper = destination = NULL;
+                        lower = NULL;
+
+                        arg_settings_mask |= SETTING_CUSTOM_MOUNTS;
+                        break;
+                }
+
+                case 'E': {
+                        char **n;
+
+                        if (!env_assignment_is_valid(optarg)) {
+                                log_error("Environment variable assignment '%s' is not valid.", optarg);
+                                return -EINVAL;
+                        }
+
+                        n = strv_env_set(arg_setenv, optarg);
+                        if (!n)
+                                return log_oom();
+
+                        strv_free(arg_setenv);
+                        arg_setenv = n;
+
+                        arg_settings_mask |= SETTING_ENVIRONMENT;
+                        break;
+                }
+
+                case 'q':
+                        arg_quiet = true;
+                        break;
+
+                case ARG_SHARE_SYSTEM:
+                        /* We don't officially support this anymore, except for compat reasons. People should use the
+                         * $SYSTEMD_NSPAWN_SHARE_* environment variables instead. */
+                        arg_clone_ns_flags = 0;
+                        break;
+
+                case ARG_REGISTER:
+                        r = parse_boolean(optarg);
+                        if (r < 0) {
+                                log_error("Failed to parse --register= argument: %s", optarg);
+                                return r;
+                        }
+
+                        arg_register = r;
+                        break;
+
+                case ARG_KEEP_UNIT:
+                        arg_keep_unit = true;
+                        break;
+
+                case ARG_PERSONALITY:
+
+                        arg_personality = personality_from_string(optarg);
+                        if (arg_personality == PERSONALITY_INVALID) {
+                                log_error("Unknown or unsupported personality '%s'.", optarg);
+                                return -EINVAL;
+                        }
+
+                        arg_settings_mask |= SETTING_PERSONALITY;
+                        break;
+
+                case ARG_VOLATILE:
+
+                        if (!optarg)
+                                arg_volatile_mode = VOLATILE_YES;
+                        else {
+                                VolatileMode m;
+
+                                m = volatile_mode_from_string(optarg);
+                                if (m < 0) {
+                                        log_error("Failed to parse --volatile= argument: %s", optarg);
+                                        return -EINVAL;
+                                } else
+                                        arg_volatile_mode = m;
+                        }
+
+                        arg_settings_mask |= SETTING_VOLATILE_MODE;
+                        break;
+
+                case 'p':
+                        r = expose_port_parse(&arg_expose_ports, optarg);
+                        if (r == -EEXIST)
+                                return log_error_errno(r, "Duplicate port specification: %s", optarg);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to parse host port %s: %m", optarg);
+
+                        arg_settings_mask |= SETTING_EXPOSE_PORTS;
+                        break;
+
+                case ARG_PROPERTY:
+                        if (strv_extend(&arg_property, optarg) < 0)
+                                return log_oom();
+
+                        break;
+
+                case ARG_PRIVATE_USERS: {
+                        int boolean = -1;
+
+                        if (!optarg)
+                                boolean = true;
+                        else if (!in_charset(optarg, DIGITS))
+                                /* do *not* parse numbers as booleans */
+                                boolean = parse_boolean(optarg);
+
+                        if (boolean == false) {
+                                /* no: User namespacing off */
+                                arg_userns_mode = USER_NAMESPACE_NO;
+                                arg_uid_shift = UID_INVALID;
+                                arg_uid_range = UINT32_C(0x10000);
+                        } else if (boolean == true) {
+                                /* yes: User namespacing on, UID range is read from root dir */
+                                arg_userns_mode = USER_NAMESPACE_FIXED;
+                                arg_uid_shift = UID_INVALID;
+                                arg_uid_range = UINT32_C(0x10000);
+                        } else if (streq(optarg, "pick")) {
+                                /* pick: User namespacing on, UID range is picked randomly */
+                                arg_userns_mode = USER_NAMESPACE_PICK;
+                                arg_uid_shift = UID_INVALID;
+                                arg_uid_range = UINT32_C(0x10000);
+                        } else {
+                                _cleanup_free_ char *buffer = NULL;
+                                const char *range, *shift;
+
+                                /* anything else: User namespacing on, UID range is explicitly configured */
+
+                                range = strchr(optarg, ':');
+                                if (range) {
+                                        buffer = strndup(optarg, range - optarg);
+                                        if (!buffer)
+                                                return log_oom();
+                                        shift = buffer;
+
+                                        range++;
+                                        r = safe_atou32(range, &arg_uid_range);
+                                        if (r < 0)
+                                                return log_error_errno(r, "Failed to parse UID range \"%s\": %m", range);
+                                } else
+                                        shift = optarg;
+
+                                r = parse_uid(shift, &arg_uid_shift);
+                                if (r < 0)
+                                        return log_error_errno(r, "Failed to parse UID \"%s\": %m", optarg);
+
+                                arg_userns_mode = USER_NAMESPACE_FIXED;
+                        }
+
+                        if (arg_uid_range <= 0) {
+                                log_error("UID range cannot be 0.");
+                                return -EINVAL;
+                        }
+
+                        arg_settings_mask |= SETTING_USERNS;
+                        break;
+                }
+
+                case 'U':
+                        if (userns_supported()) {
+                                arg_userns_mode = USER_NAMESPACE_PICK;
+                                arg_uid_shift = UID_INVALID;
+                                arg_uid_range = UINT32_C(0x10000);
+
+                                arg_settings_mask |= SETTING_USERNS;
+                        }
+
+                        break;
+
+                case ARG_PRIVATE_USERS_CHOWN:
+                        arg_userns_chown = true;
+
+                        arg_settings_mask |= SETTING_USERNS;
+                        break;
+
+                case ARG_KILL_SIGNAL:
+                        arg_kill_signal = signal_from_string_try_harder(optarg);
+                        if (arg_kill_signal < 0) {
+                                log_error("Cannot parse signal: %s", optarg);
+                                return -EINVAL;
+                        }
+
+                        arg_settings_mask |= SETTING_KILL_SIGNAL;
+                        break;
+
+                case ARG_SETTINGS:
+
+                        /* no               → do not read files
+                         * yes              → read files, do not override cmdline, trust only subset
+                         * override         → read files, override cmdline, trust only subset
+                         * trusted          → read files, do not override cmdline, trust all
+                         */
+
+                        r = parse_boolean(optarg);
+                        if (r < 0) {
+                                if (streq(optarg, "trusted")) {
+                                        mask_all_settings = false;
+                                        mask_no_settings = false;
+                                        arg_settings_trusted = true;
+
+                                } else if (streq(optarg, "override")) {
+                                        mask_all_settings = false;
+                                        mask_no_settings = true;
+                                        arg_settings_trusted = -1;
+                                } else
+                                        return log_error_errno(r, "Failed to parse --settings= argument: %s", optarg);
+                        } else if (r > 0) {
+                                /* yes */
+                                mask_all_settings = false;
+                                mask_no_settings = false;
+                                arg_settings_trusted = -1;
+                        } else {
+                                /* no */
+                                mask_all_settings = true;
+                                mask_no_settings = false;
+                                arg_settings_trusted = false;
+                        }
+
+                        break;
+
+                case ARG_CHDIR:
+                        if (!path_is_absolute(optarg)) {
+                                log_error("Working directory %s is not an absolute path.", optarg);
+                                return -EINVAL;
+                        }
+
+                        r = free_and_strdup(&arg_chdir, optarg);
+                        if (r < 0)
+                                return log_oom();
+
+                        arg_settings_mask |= SETTING_WORKING_DIRECTORY;
+                        break;
+
+                case ARG_NOTIFY_READY:
+                        r = parse_boolean(optarg);
+                        if (r < 0) {
+                                log_error("%s is not a valid notify mode. Valid modes are: yes, no, and ready.", optarg);
+                                return -EINVAL;
+                        }
+                        arg_notify_ready = r;
+                        arg_settings_mask |= SETTING_NOTIFY_READY;
+                        break;
+
+                case '?':
+                        return -EINVAL;
+
+                default:
+                        assert_not_reached("Unhandled option");
+                }
+
+        parse_share_ns_env("SYSTEMD_NSPAWN_SHARE_NS_IPC", CLONE_NEWIPC);
+        parse_share_ns_env("SYSTEMD_NSPAWN_SHARE_NS_PID", CLONE_NEWPID);
+        parse_share_ns_env("SYSTEMD_NSPAWN_SHARE_NS_UTS", CLONE_NEWUTS);
+        parse_share_ns_env("SYSTEMD_NSPAWN_SHARE_SYSTEM", CLONE_NEWIPC|CLONE_NEWPID|CLONE_NEWUTS);
+
+        if (!(arg_clone_ns_flags & CLONE_NEWPID) ||
+            !(arg_clone_ns_flags & CLONE_NEWUTS)) {
+                arg_register = false;
+                if (arg_start_mode != START_PID1) {
+                        log_error("--boot cannot be used without namespacing.");
+                        return -EINVAL;
+                }
+        }
+
+        if (arg_userns_mode == USER_NAMESPACE_PICK)
+                arg_userns_chown = true;
+
+        if (arg_keep_unit && cg_pid_get_owner_uid(0, NULL) >= 0) {
+                log_error("--keep-unit may not be used when invoked from a user session.");
+                return -EINVAL;
+        }
+
+        if (arg_directory && arg_image) {
+                log_error("--directory= and --image= may not be combined.");
+                return -EINVAL;
+        }
+
+        if (arg_template && arg_image) {
+                log_error("--template= and --image= may not be combined.");
+                return -EINVAL;
+        }
+
+        if (arg_template && !(arg_directory || arg_machine)) {
+                log_error("--template= needs --directory= or --machine=.");
+                return -EINVAL;
+        }
+
+        if (arg_ephemeral && arg_template) {
+                log_error("--ephemeral and --template= may not be combined.");
+                return -EINVAL;
+        }
+
+        if (arg_ephemeral && arg_image) {
+                log_error("--ephemeral and --image= may not be combined.");
+                return -EINVAL;
+        }
+
+        if (arg_ephemeral && !IN_SET(arg_link_journal, LINK_NO, LINK_AUTO)) {
+                log_error("--ephemeral and --link-journal= may not be combined.");
+                return -EINVAL;
+        }
+
+        if (arg_userns_mode != USER_NAMESPACE_NO && !userns_supported()) {
+                log_error("--private-users= is not supported, kernel compiled without user namespace support.");
+                return -EOPNOTSUPP;
+        }
+
+        if (arg_userns_chown && arg_read_only) {
+                log_error("--read-only and --private-users-chown may not be combined.");
+                return -EINVAL;
+        }
+
+        if (arg_network_bridge && arg_network_zone) {
+                log_error("--network-bridge= and --network-zone= may not be combined.");
+                return -EINVAL;
+        }
+
+        if (argc > optind) {
+                arg_parameters = strv_copy(argv + optind);
+                if (!arg_parameters)
+                        return log_oom();
+
+                arg_settings_mask |= SETTING_START_MODE;
+        }
+
+        /* Load all settings from .nspawn files */
+        if (mask_no_settings)
+                arg_settings_mask = 0;
+
+        /* Don't load any settings from .nspawn files */
+        if (mask_all_settings)
+                arg_settings_mask = _SETTINGS_MASK_ALL;
+
+        arg_caps_retain = (arg_caps_retain | plus | (arg_private_network ? 1ULL << CAP_NET_ADMIN : 0)) & ~minus;
+
+        e = getenv("SYSTEMD_NSPAWN_CONTAINER_SERVICE");
+        if (e)
+                arg_container_service_name = e;
+
+        r = getenv_bool("SYSTEMD_NSPAWN_USE_CGNS");
+        if (r < 0)
+                arg_use_cgns = cg_ns_supported();
+        else
+                arg_use_cgns = r;
+
+        return 1;
+}
+
+static int verify_arguments(void) {
+
+        if (arg_volatile_mode != VOLATILE_NO && arg_read_only) {
+                log_error("Cannot combine --read-only with --volatile. Note that --volatile already implies a read-only base hierarchy.");
+                return -EINVAL;
+        }
+
+        if (arg_expose_ports && !arg_private_network) {
+                log_error("Cannot use --port= without private networking.");
+                return -EINVAL;
+        }
+
+#ifndef HAVE_LIBIPTC
+        if (arg_expose_ports) {
+                log_error("--port= is not supported, compiled without libiptc support.");
+                return -EOPNOTSUPP;
+        }
+#endif
+
+        if (arg_start_mode == START_BOOT && arg_kill_signal <= 0)
+                arg_kill_signal = SIGRTMIN+3;
+
+        return 0;
+}
+
+static int userns_lchown(const char *p, uid_t uid, gid_t gid) {
+        assert(p);
+
+        if (arg_userns_mode == USER_NAMESPACE_NO)
+                return 0;
+
+        if (uid == UID_INVALID && gid == GID_INVALID)
+                return 0;
+
+        if (uid != UID_INVALID) {
+                uid += arg_uid_shift;
+
+                if (uid < arg_uid_shift || uid >= arg_uid_shift + arg_uid_range)
+                        return -EOVERFLOW;
+        }
+
+        if (gid != GID_INVALID) {
+                gid += (gid_t) arg_uid_shift;
+
+                if (gid < (gid_t) arg_uid_shift || gid >= (gid_t) (arg_uid_shift + arg_uid_range))
+                        return -EOVERFLOW;
+        }
+
+        if (lchown(p, uid, gid) < 0)
+                return -errno;
+
+        return 0;
+}
+
+static int userns_mkdir(const char *root, const char *path, mode_t mode, uid_t uid, gid_t gid) {
+        const char *q;
+
+        q = prefix_roota(root, path);
+        if (mkdir(q, mode) < 0) {
+                if (errno == EEXIST)
+                        return 0;
+                return -errno;
+        }
+
+        return userns_lchown(q, uid, gid);
+}
+
+static int setup_timezone(const char *dest) {
+        _cleanup_free_ char *p = NULL, *q = NULL;
+        const char *where, *check, *what;
+        char *z, *y;
+        int r;
+
+        assert(dest);
+
+        /* Fix the timezone, if possible */
+        r = readlink_malloc("/etc/localtime", &p);
+        if (r < 0) {
+                log_warning("host's /etc/localtime is not a symlink, not updating container timezone.");
+                /* to handle warning, delete /etc/localtime and replace it
+                 * with a symbolic link to a time zone data file.
+                 *
+                 * Example:
+                 * ln -s /usr/share/zoneinfo/UTC /etc/localtime
+                 */
+                return 0;
+        }
+
+        z = path_startswith(p, "../usr/share/zoneinfo/");
+        if (!z)
+                z = path_startswith(p, "/usr/share/zoneinfo/");
+        if (!z) {
+                log_warning("/etc/localtime does not point into /usr/share/zoneinfo/, not updating container timezone.");
+                return 0;
+        }
+
+        where = prefix_roota(dest, "/etc/localtime");
+        r = readlink_malloc(where, &q);
+        if (r >= 0) {
+                y = path_startswith(q, "../usr/share/zoneinfo/");
+                if (!y)
+                        y = path_startswith(q, "/usr/share/zoneinfo/");
+
+                /* Already pointing to the right place? Then do nothing .. */
+                if (y && streq(y, z))
+                        return 0;
+        }
+
+        check = strjoina("/usr/share/zoneinfo/", z);
+        check = prefix_roota(dest, check);
+        if (laccess(check, F_OK) < 0) {
+                log_warning("Timezone %s does not exist in container, not updating container timezone.", z);
+                return 0;
+        }
+
+        r = unlink(where);
+        if (r < 0 && errno != ENOENT) {
+                log_error_errno(errno, "Failed to remove existing timezone info %s in container: %m", where);
+                return 0;
+        }
+
+        what = strjoina("../usr/share/zoneinfo/", z);
+        if (symlink(what, where) < 0) {
+                log_error_errno(errno, "Failed to correct timezone of container: %m");
+                return 0;
+        }
+
+        r = userns_lchown(where, 0, 0);
+        if (r < 0)
+                return log_warning_errno(r, "Failed to chown /etc/localtime: %m");
+
+        return 0;
+}
+
+static int setup_resolv_conf(const char *dest) {
+        const char *where = NULL;
+        int r;
+
+        assert(dest);
+
+        if (arg_private_network)
+                return 0;
+
+        /* Fix resolv.conf, if possible */
+        where = prefix_roota(dest, "/etc/resolv.conf");
+
+        r = copy_file("/etc/resolv.conf", where, O_TRUNC|O_NOFOLLOW, 0644, 0);
+        if (r < 0) {
+                /* If the file already exists as symlink, let's
+                 * suppress the warning, under the assumption that
+                 * resolved or something similar runs inside and the
+                 * symlink points there.
+                 *
+                 * If the disk image is read-only, there's also no
+                 * point in complaining.
+                 */
+                log_full_errno(IN_SET(r, -ELOOP, -EROFS) ? LOG_DEBUG : LOG_WARNING, r,
+                               "Failed to copy /etc/resolv.conf to %s: %m", where);
+                return 0;
+        }
+
+        r = userns_lchown(where, 0, 0);
+        if (r < 0)
+                log_warning_errno(r, "Failed to chown /etc/resolv.conf: %m");
+
+        return 0;
+}
+
+static int setup_boot_id(const char *dest) {
+        sd_id128_t rnd = SD_ID128_NULL;
+        const char *from, *to;
+        int r;
+
+        /* Generate a new randomized boot ID, so that each boot-up of
+         * the container gets a new one */
+
+        from = prefix_roota(dest, "/run/proc-sys-kernel-random-boot-id");
+        to = prefix_roota(dest, "/proc/sys/kernel/random/boot_id");
+
+        r = sd_id128_randomize(&rnd);
+        if (r < 0)
+                return log_error_errno(r, "Failed to generate random boot id: %m");
+
+        r = id128_write(from, ID128_UUID, rnd, false);
+        if (r < 0)
+                return log_error_errno(r, "Failed to write boot id: %m");
+
+        r = mount_verbose(LOG_ERR, from, to, NULL, MS_BIND, NULL);
+        if (r >= 0)
+                r = mount_verbose(LOG_ERR, NULL, to, NULL,
+                                  MS_BIND|MS_REMOUNT|MS_RDONLY|MS_NOSUID|MS_NODEV, NULL);
+
+        (void) unlink(from);
+        return r;
+}
+
+static int copy_devnodes(const char *dest) {
+
+        static const char devnodes[] =
+                "null\0"
+                "zero\0"
+                "full\0"
+                "random\0"
+                "urandom\0"
+                "tty\0"
+                "net/tun\0";
+
+        const char *d;
+        int r = 0;
+        _cleanup_umask_ mode_t u;
+
+        assert(dest);
+
+        u = umask(0000);
+
+        /* Create /dev/net, so that we can create /dev/net/tun in it */
+        if (userns_mkdir(dest, "/dev/net", 0755, 0, 0) < 0)
+                return log_error_errno(r, "Failed to create /dev/net directory: %m");
+
+        NULSTR_FOREACH(d, devnodes) {
+                _cleanup_free_ char *from = NULL, *to = NULL;
+                struct stat st;
+
+                from = strappend("/dev/", d);
+                to = prefix_root(dest, from);
+
+                if (stat(from, &st) < 0) {
+
+                        if (errno != ENOENT)
+                                return log_error_errno(errno, "Failed to stat %s: %m", from);
+
+                } else if (!S_ISCHR(st.st_mode) && !S_ISBLK(st.st_mode)) {
+
+                        log_error("%s is not a char or block device, cannot copy.", from);
+                        return -EIO;
+
+                } else {
+                        if (mknod(to, st.st_mode, st.st_rdev) < 0) {
+                                /*
+                                 * This is some sort of protection too against
+                                 * recursive userns chown on shared /dev/
+                                 */
+                                if (errno == EEXIST)
+                                        log_notice("%s/dev/ should be an empty directory", dest);
+                                if (errno != EPERM)
+                                        return log_error_errno(errno, "mknod(%s) failed: %m", to);
+
+                                /* Some systems abusively restrict mknod but
+                                 * allow bind mounts. */
+                                r = touch(to);
+                                if (r < 0)
+                                        return log_error_errno(r, "touch (%s) failed: %m", to);
+                                r = mount_verbose(LOG_DEBUG, from, to, NULL, MS_BIND, NULL);
+                                if (r < 0)
+                                        return log_error_errno(r, "Both mknod and bind mount (%s) failed: %m", to);
+                        }
+
+                        r = userns_lchown(to, 0, 0);
+                        if (r < 0)
+                                return log_error_errno(r, "chown() of device node %s failed: %m", to);
+                }
+        }
+
+        return r;
+}
+
+static int setup_pts(const char *dest) {
+        _cleanup_free_ char *options = NULL;
+        const char *p;
+        int r;
+
+#ifdef HAVE_SELINUX
+        if (arg_selinux_apifs_context)
+                (void) asprintf(&options,
+                                "newinstance,ptmxmode=0666,mode=620,gid=" GID_FMT ",context=\"%s\"",
+                                arg_uid_shift + TTY_GID,
+                                arg_selinux_apifs_context);
+        else
+#endif
+                (void) asprintf(&options,
+                                "newinstance,ptmxmode=0666,mode=620,gid=" GID_FMT,
+                                arg_uid_shift + TTY_GID);
+
+        if (!options)
+                return log_oom();
+
+        /* Mount /dev/pts itself */
+        p = prefix_roota(dest, "/dev/pts");
+        if (mkdir(p, 0755) < 0)
+                return log_error_errno(errno, "Failed to create /dev/pts: %m");
+        r = mount_verbose(LOG_ERR, "devpts", p, "devpts", MS_NOSUID|MS_NOEXEC, options);
+        if (r < 0)
+                return r;
+        r = userns_lchown(p, 0, 0);
+        if (r < 0)
+                return log_error_errno(r, "Failed to chown /dev/pts: %m");
+
+        /* Create /dev/ptmx symlink */
+        p = prefix_roota(dest, "/dev/ptmx");
+        if (symlink("pts/ptmx", p) < 0)
+                return log_error_errno(errno, "Failed to create /dev/ptmx symlink: %m");
+        r = userns_lchown(p, 0, 0);
+        if (r < 0)
+                return log_error_errno(r, "Failed to chown /dev/ptmx: %m");
+
+        /* And fix /dev/pts/ptmx ownership */
+        p = prefix_roota(dest, "/dev/pts/ptmx");
+        r = userns_lchown(p, 0, 0);
+        if (r < 0)
+                return log_error_errno(r, "Failed to chown /dev/pts/ptmx: %m");
+
+        return 0;
+}
+
+static int setup_dev_console(const char *dest, const char *console) {
+        _cleanup_umask_ mode_t u;
+        const char *to;
+        int r;
+
+        assert(dest);
+        assert(console);
+
+        u = umask(0000);
+
+        r = chmod_and_chown(console, 0600, arg_uid_shift, arg_uid_shift);
+        if (r < 0)
+                return log_error_errno(r, "Failed to correct access mode for TTY: %m");
+
+        /* We need to bind mount the right tty to /dev/console since
+         * ptys can only exist on pts file systems. To have something
+         * to bind mount things on we create a empty regular file. */
+
+        to = prefix_roota(dest, "/dev/console");
+        r = touch(to);
+        if (r < 0)
+                return log_error_errno(r, "touch() for /dev/console failed: %m");
+
+        return mount_verbose(LOG_ERR, console, to, NULL, MS_BIND, NULL);
+}
+
+static int setup_kmsg(const char *dest, int kmsg_socket) {
+        const char *from, *to;
+        _cleanup_umask_ mode_t u;
+        int fd, r;
+
+        assert(kmsg_socket >= 0);
+
+        u = umask(0000);
+
+        /* We create the kmsg FIFO as /run/kmsg, but immediately
+         * delete it after bind mounting it to /proc/kmsg. While FIFOs
+         * on the reading side behave very similar to /proc/kmsg,
+         * their writing side behaves differently from /dev/kmsg in
+         * that writing blocks when nothing is reading. In order to
+         * avoid any problems with containers deadlocking due to this
+         * we simply make /dev/kmsg unavailable to the container. */
+        from = prefix_roota(dest, "/run/kmsg");
+        to = prefix_roota(dest, "/proc/kmsg");
+
+        if (mkfifo(from, 0600) < 0)
+                return log_error_errno(errno, "mkfifo() for /run/kmsg failed: %m");
+        r = mount_verbose(LOG_ERR, from, to, NULL, MS_BIND, NULL);
+        if (r < 0)
+                return r;
+
+        fd = open(from, O_RDWR|O_NDELAY|O_CLOEXEC);
+        if (fd < 0)
+                return log_error_errno(errno, "Failed to open fifo: %m");
+
+        /* Store away the fd in the socket, so that it stays open as
+         * long as we run the child */
+        r = send_one_fd(kmsg_socket, fd, 0);
+        safe_close(fd);
+
+        if (r < 0)
+                return log_error_errno(r, "Failed to send FIFO fd: %m");
+
+        /* And now make the FIFO unavailable as /run/kmsg... */
+        (void) unlink(from);
+
+        return 0;
+}
+
+static int on_address_change(sd_netlink *rtnl, sd_netlink_message *m, void *userdata) {
+        union in_addr_union *exposed = userdata;
+
+        assert(rtnl);
+        assert(m);
+        assert(exposed);
+
+        expose_port_execute(rtnl, arg_expose_ports, exposed);
+        return 0;
+}
+
+static int setup_hostname(void) {
+
+        if ((arg_clone_ns_flags & CLONE_NEWUTS) == 0)
+                return 0;
+
+        if (sethostname_idempotent(arg_machine) < 0)
+                return -errno;
+
+        return 0;
+}
+
+static int setup_journal(const char *directory) {
+        sd_id128_t this_id;
+        _cleanup_free_ char *d = NULL;
+        const char *p, *q;
+        bool try;
+        char id[33];
+        int r;
+
+        /* Don't link journals in ephemeral mode */
+        if (arg_ephemeral)
+                return 0;
+
+        if (arg_link_journal == LINK_NO)
+                return 0;
+
+        try = arg_link_journal_try || arg_link_journal == LINK_AUTO;
+
+        r = sd_id128_get_machine(&this_id);
+        if (r < 0)
+                return log_error_errno(r, "Failed to retrieve machine ID: %m");
+
+        if (sd_id128_equal(arg_uuid, this_id)) {
+                log_full(try ? LOG_WARNING : LOG_ERR,
+                         "Host and machine ids are equal (%s): refusing to link journals", sd_id128_to_string(arg_uuid, id));
+                if (try)
+                        return 0;
+                return -EEXIST;
+        }
+
+        r = userns_mkdir(directory, "/var", 0755, 0, 0);
+        if (r < 0)
+                return log_error_errno(r, "Failed to create /var: %m");
+
+        r = userns_mkdir(directory, "/var/log", 0755, 0, 0);
+        if (r < 0)
+                return log_error_errno(r, "Failed to create /var/log: %m");
+
+        r = userns_mkdir(directory, "/var/log/journal", 0755, 0, 0);
+        if (r < 0)
+                return log_error_errno(r, "Failed to create /var/log/journal: %m");
+
+        (void) sd_id128_to_string(arg_uuid, id);
+
+        p = strjoina("/var/log/journal/", id);
+        q = prefix_roota(directory, p);
+
+        if (path_is_mount_point(p, 0) > 0) {
+                if (try)
+                        return 0;
+
+                log_error("%s: already a mount point, refusing to use for journal", p);
+                return -EEXIST;
+        }
+
+        if (path_is_mount_point(q, 0) > 0) {
+                if (try)
+                        return 0;
+
+                log_error("%s: already a mount point, refusing to use for journal", q);
+                return -EEXIST;
+        }
+
+        r = readlink_and_make_absolute(p, &d);
+        if (r >= 0) {
+                if ((arg_link_journal == LINK_GUEST ||
+                     arg_link_journal == LINK_AUTO) &&
+                    path_equal(d, q)) {
+
+                        r = userns_mkdir(directory, p, 0755, 0, 0);
+                        if (r < 0)
+                                log_warning_errno(r, "Failed to create directory %s: %m", q);
+                        return 0;
+                }
+
+                if (unlink(p) < 0)
+                        return log_error_errno(errno, "Failed to remove symlink %s: %m", p);
+        } else if (r == -EINVAL) {
+
+                if (arg_link_journal == LINK_GUEST &&
+                    rmdir(p) < 0) {
+
+                        if (errno == ENOTDIR) {
+                                log_error("%s already exists and is neither a symlink nor a directory", p);
+                                return r;
+                        } else
+                                return log_error_errno(errno, "Failed to remove %s: %m", p);
+                }
+        } else if (r != -ENOENT)
+                return log_error_errno(r, "readlink(%s) failed: %m", p);
+
+        if (arg_link_journal == LINK_GUEST) {
+
+                if (symlink(q, p) < 0) {
+                        if (try) {
+                                log_debug_errno(errno, "Failed to symlink %s to %s, skipping journal setup: %m", q, p);
+                                return 0;
+                        } else
+                                return log_error_errno(errno, "Failed to symlink %s to %s: %m", q, p);
+                }
+
+                r = userns_mkdir(directory, p, 0755, 0, 0);
+                if (r < 0)
+                        log_warning_errno(r, "Failed to create directory %s: %m", q);
+                return 0;
+        }
+
+        if (arg_link_journal == LINK_HOST) {
+                /* don't create parents here — if the host doesn't have
+                 * permanent journal set up, don't force it here */
+
+                if (mkdir(p, 0755) < 0 && errno != EEXIST) {
+                        if (try) {
+                                log_debug_errno(errno, "Failed to create %s, skipping journal setup: %m", p);
+                                return 0;
+                        } else
+                                return log_error_errno(errno, "Failed to create %s: %m", p);
+                }
+
+        } else if (access(p, F_OK) < 0)
+                return 0;
+
+        if (dir_is_empty(q) == 0)
+                log_warning("%s is not empty, proceeding anyway.", q);
+
+        r = userns_mkdir(directory, p, 0755, 0, 0);
+        if (r < 0)
+                return log_error_errno(r, "Failed to create %s: %m", q);
+
+        r = mount_verbose(LOG_DEBUG, p, q, NULL, MS_BIND, NULL);
+        if (r < 0)
+                return log_error_errno(errno, "Failed to bind mount journal from host into guest: %m");
+
+        return 0;
+}
+
+static int drop_capabilities(void) {
+        return capability_bounding_set_drop(arg_caps_retain, false);
+}
+
+static int reset_audit_loginuid(void) {
+        _cleanup_free_ char *p = NULL;
+        int r;
+
+        if ((arg_clone_ns_flags & CLONE_NEWPID) == 0)
+                return 0;
+
+        r = read_one_line_file("/proc/self/loginuid", &p);
+        if (r == -ENOENT)
+                return 0;
+        if (r < 0)
+                return log_error_errno(r, "Failed to read /proc/self/loginuid: %m");
+
+        /* Already reset? */
+        if (streq(p, "4294967295"))
+                return 0;
+
+        r = write_string_file("/proc/self/loginuid", "4294967295", 0);
+        if (r < 0) {
+                log_error_errno(r,
+                                "Failed to reset audit login UID. This probably means that your kernel is too\n"
+                                "old and you have audit enabled. Note that the auditing subsystem is known to\n"
+                                "be incompatible with containers on old kernels. Please make sure to upgrade\n"
+                                "your kernel or to off auditing with 'audit=0' on the kernel command line before\n"
+                                "using systemd-nspawn. Sleeping for 5s... (%m)");
+
+                sleep(5);
+        }
+
+        return 0;
+}
+
+
+static int setup_propagate(const char *root) {
+        const char *p, *q;
+        int r;
+
+        (void) mkdir_p("/run/systemd/nspawn/", 0755);
+        (void) mkdir_p("/run/systemd/nspawn/propagate", 0600);
+        p = strjoina("/run/systemd/nspawn/propagate/", arg_machine);
+        (void) mkdir_p(p, 0600);
+
+        r = userns_mkdir(root, "/run/systemd", 0755, 0, 0);
+        if (r < 0)
+                return log_error_errno(r, "Failed to create /run/systemd: %m");
+
+        r = userns_mkdir(root, "/run/systemd/nspawn", 0755, 0, 0);
+        if (r < 0)
+                return log_error_errno(r, "Failed to create /run/systemd/nspawn: %m");
+
+        r = userns_mkdir(root, "/run/systemd/nspawn/incoming", 0600, 0, 0);
+        if (r < 0)
+                return log_error_errno(r, "Failed to create /run/systemd/nspawn/incoming: %m");
+
+        q = prefix_roota(root, "/run/systemd/nspawn/incoming");
+        r = mount_verbose(LOG_ERR, p, q, NULL, MS_BIND, NULL);
+        if (r < 0)
+                return r;
+
+        r = mount_verbose(LOG_ERR, NULL, q, NULL, MS_BIND|MS_REMOUNT|MS_RDONLY, NULL);
+        if (r < 0)
+                return r;
+
+        /* machined will MS_MOVE into that directory, and that's only
+         * supported for non-shared mounts. */
+        return mount_verbose(LOG_ERR, NULL, q, NULL, MS_SLAVE, NULL);
+}
+
+static int setup_image(char **device_path, int *loop_nr) {
+        struct loop_info64 info = {
+                .lo_flags = LO_FLAGS_AUTOCLEAR|LO_FLAGS_PARTSCAN
+        };
+        _cleanup_close_ int fd = -1, control = -1, loop = -1;
+        _cleanup_free_ char* loopdev = NULL;
+        struct stat st;
+        int r, nr;
+
+        assert(device_path);
+        assert(loop_nr);
+        assert(arg_image);
+
+        fd = open(arg_image, O_CLOEXEC|(arg_read_only ? O_RDONLY : O_RDWR)|O_NONBLOCK|O_NOCTTY);
+        if (fd < 0)
+                return log_error_errno(errno, "Failed to open %s: %m", arg_image);
+
+        if (fstat(fd, &st) < 0)
+                return log_error_errno(errno, "Failed to stat %s: %m", arg_image);
+
+        if (S_ISBLK(st.st_mode)) {
+                char *p;
+
+                p = strdup(arg_image);
+                if (!p)
+                        return log_oom();
+
+                *device_path = p;
+
+                *loop_nr = -1;
+
+                r = fd;
+                fd = -1;
+
+                return r;
+        }
+
+        if (!S_ISREG(st.st_mode)) {
+                log_error("%s is not a regular file or block device.", arg_image);
+                return -EINVAL;
+        }
+
+        control = open("/dev/loop-control", O_RDWR|O_CLOEXEC|O_NOCTTY|O_NONBLOCK);
+        if (control < 0)
+                return log_error_errno(errno, "Failed to open /dev/loop-control: %m");
+
+        nr = ioctl(control, LOOP_CTL_GET_FREE);
+        if (nr < 0)
+                return log_error_errno(errno, "Failed to allocate loop device: %m");
+
+        if (asprintf(&loopdev, "/dev/loop%i", nr) < 0)
+                return log_oom();
+
+        loop = open(loopdev, O_CLOEXEC|(arg_read_only ? O_RDONLY : O_RDWR)|O_NONBLOCK|O_NOCTTY);
+        if (loop < 0)
+                return log_error_errno(errno, "Failed to open loop device %s: %m", loopdev);
+
+        if (ioctl(loop, LOOP_SET_FD, fd) < 0)
+                return log_error_errno(errno, "Failed to set loopback file descriptor on %s: %m", loopdev);
+
+        if (arg_read_only)
+                info.lo_flags |= LO_FLAGS_READ_ONLY;
+
+        if (ioctl(loop, LOOP_SET_STATUS64, &info) < 0)
+                return log_error_errno(errno, "Failed to set loopback settings on %s: %m", loopdev);
+
+        *device_path = loopdev;
+        loopdev = NULL;
+
+        *loop_nr = nr;
+
+        r = loop;
+        loop = -1;
+
+        return r;
+}
+
+#define PARTITION_TABLE_BLURB \
+        "Note that the disk image needs to either contain only a single MBR partition of\n" \
+        "type 0x83 that is marked bootable, or a single GPT partition of type " \
+        "0FC63DAF-8483-4772-8E79-3D69D8477DE4 or follow\n" \
+        "    http://www.freedesktop.org/wiki/Specifications/DiscoverablePartitionsSpec/\n" \
+        "to be bootable with systemd-nspawn."
+
+static int dissect_image(
+                int fd,
+                char **root_device, bool *root_device_rw,
+                char **home_device, bool *home_device_rw,
+                char **srv_device, bool *srv_device_rw,
+                char **esp_device,
+                bool *secondary) {
+
+#ifdef HAVE_BLKID
+        int home_nr = -1, srv_nr = -1, esp_nr = -1;
+#ifdef GPT_ROOT_NATIVE
+        int root_nr = -1;
+#endif
+#ifdef GPT_ROOT_SECONDARY
+        int secondary_root_nr = -1;
+#endif
+        _cleanup_free_ char *home = NULL, *root = NULL, *secondary_root = NULL, *srv = NULL, *esp = NULL, *generic = NULL;
+        _cleanup_udev_enumerate_unref_ struct udev_enumerate *e = NULL;
+        _cleanup_udev_device_unref_ struct udev_device *d = NULL;
+        _cleanup_blkid_free_probe_ blkid_probe b = NULL;
+        _cleanup_udev_unref_ struct udev *udev = NULL;
+        struct udev_list_entry *first, *item;
+        bool home_rw = true, root_rw = true, secondary_root_rw = true, srv_rw = true, generic_rw = true;
+        bool is_gpt, is_mbr, multiple_generic = false;
+        const char *pttype = NULL;
+        blkid_partlist pl;
+        struct stat st;
+        unsigned i;
+        int r;
+
+        assert(fd >= 0);
+        assert(root_device);
+        assert(home_device);
+        assert(srv_device);
+        assert(esp_device);
+        assert(secondary);
+        assert(arg_image);
+
+        b = blkid_new_probe();
+        if (!b)
+                return log_oom();
+
+        errno = 0;
+        r = blkid_probe_set_device(b, fd, 0, 0);
+        if (r != 0) {
+                if (errno == 0)
+                        return log_oom();
+
+                return log_error_errno(errno, "Failed to set device on blkid probe: %m");
+        }
+
+        blkid_probe_enable_partitions(b, 1);
+        blkid_probe_set_partitions_flags(b, BLKID_PARTS_ENTRY_DETAILS);
+
+        errno = 0;
+        r = blkid_do_safeprobe(b);
+        if (r == -2 || r == 1) {
+                log_error("Failed to identify any partition table on\n"
+                          "    %s\n"
+                          PARTITION_TABLE_BLURB, arg_image);
+                return -EINVAL;
+        } else if (r != 0) {
+                if (errno == 0)
+                        errno = EIO;
+                return log_error_errno(errno, "Failed to probe: %m");
+        }
+
+        (void) blkid_probe_lookup_value(b, "PTTYPE", &pttype, NULL);
+
+        is_gpt = streq_ptr(pttype, "gpt");
+        is_mbr = streq_ptr(pttype, "dos");
+
+        if (!is_gpt && !is_mbr) {
+                log_error("No GPT or MBR partition table discovered on\n"
+                          "    %s\n"
+                          PARTITION_TABLE_BLURB, arg_image);
+                return -EINVAL;
+        }
+
+        errno = 0;
+        pl = blkid_probe_get_partitions(b);
+        if (!pl) {
+                if (errno == 0)
+                        return log_oom();
+
+                log_error("Failed to list partitions of %s", arg_image);
+                return -errno;
+        }
+
+        udev = udev_new();
+        if (!udev)
+                return log_oom();
+
+        if (fstat(fd, &st) < 0)
+                return log_error_errno(errno, "Failed to stat block device: %m");
+
+        d = udev_device_new_from_devnum(udev, 'b', st.st_rdev);
+        if (!d)
+                return log_oom();
+
+        for (i = 0;; i++) {
+                int n, m;
+
+                if (i >= 10) {
+                        log_error("Kernel partitions never appeared.");
+                        return -ENXIO;
+                }
+
+                e = udev_enumerate_new(udev);
+                if (!e)
+                        return log_oom();
+
+                r = udev_enumerate_add_match_parent(e, d);
+                if (r < 0)
+                        return log_oom();
+
+                r = udev_enumerate_scan_devices(e);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to scan for partition devices of %s: %m", arg_image);
+
+                /* Count the partitions enumerated by the kernel */
+                n = 0;
+                first = udev_enumerate_get_list_entry(e);
+                udev_list_entry_foreach(item, first)
+                        n++;
+
+                /* Count the partitions enumerated by blkid */
+                m = blkid_partlist_numof_partitions(pl);
+                if (n == m + 1)
+                        break;
+                if (n > m + 1) {
+                        log_error("blkid and kernel partition list do not match.");
+                        return -EIO;
+                }
+                if (n < m + 1) {
+                        unsigned j;
+
+                        /* The kernel has probed fewer partitions than
+                         * blkid? Maybe the kernel prober is still
+                         * running or it got EBUSY because udev
+                         * already opened the device. Let's reprobe
+                         * the device, which is a synchronous call
+                         * that waits until probing is complete. */
+
+                        for (j = 0; j < 20; j++) {
+
+                                r = ioctl(fd, BLKRRPART, 0);
+                                if (r < 0)
+                                        r = -errno;
+                                if (r >= 0 || r != -EBUSY)
+                                        break;
+
+                                /* If something else has the device
+                                 * open, such as an udev rule, the
+                                 * ioctl will return EBUSY. Since
+                                 * there's no way to wait until it
+                                 * isn't busy anymore, let's just wait
+                                 * a bit, and try again.
+                                 *
+                                 * This is really something they
+                                 * should fix in the kernel! */
+
+                                usleep(50 * USEC_PER_MSEC);
+                        }
+
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to reread partition table: %m");
+                }
+
+                e = udev_enumerate_unref(e);
+        }
+
+        first = udev_enumerate_get_list_entry(e);
+        udev_list_entry_foreach(item, first) {
+                _cleanup_udev_device_unref_ struct udev_device *q;
+                const char *node;
+                unsigned long long flags;
+                blkid_partition pp;
+                dev_t qn;
+                int nr;
+
+                errno = 0;
+                q = udev_device_new_from_syspath(udev, udev_list_entry_get_name(item));
+                if (!q) {
+                        if (!errno)
+                                errno = ENOMEM;
+
+                        return log_error_errno(errno, "Failed to get partition device of %s: %m", arg_image);
+                }
+
+                qn = udev_device_get_devnum(q);
+                if (major(qn) == 0)
+                        continue;
+
+                if (st.st_rdev == qn)
+                        continue;
+
+                node = udev_device_get_devnode(q);
+                if (!node)
+                        continue;
+
+                pp = blkid_partlist_devno_to_partition(pl, qn);
+                if (!pp)
+                        continue;
+
+                flags = blkid_partition_get_flags(pp);
+
+                nr = blkid_partition_get_partno(pp);
+                if (nr < 0)
+                        continue;
+
+                if (is_gpt) {
+                        sd_id128_t type_id;
+                        const char *stype;
+
+                        if (flags & GPT_FLAG_NO_AUTO)
+                                continue;
+
+                        stype = blkid_partition_get_type_string(pp);
+                        if (!stype)
+                                continue;
+
+                        if (sd_id128_from_string(stype, &type_id) < 0)
+                                continue;
+
+                        if (sd_id128_equal(type_id, GPT_HOME)) {
+
+                                if (home && nr >= home_nr)
+                                        continue;
+
+                                home_nr = nr;
+                                home_rw = !(flags & GPT_FLAG_READ_ONLY);
+
+                                r = free_and_strdup(&home, node);
+                                if (r < 0)
+                                        return log_oom();
+
+                        } else if (sd_id128_equal(type_id, GPT_SRV)) {
+
+                                if (srv && nr >= srv_nr)
+                                        continue;
+
+                                srv_nr = nr;
+                                srv_rw = !(flags & GPT_FLAG_READ_ONLY);
+
+                                r = free_and_strdup(&srv, node);
+                                if (r < 0)
+                                        return log_oom();
+                        } else if (sd_id128_equal(type_id, GPT_ESP)) {
+
+                                if (esp && nr >= esp_nr)
+                                        continue;
+
+                                esp_nr = nr;
+
+                                r = free_and_strdup(&esp, node);
+                                if (r < 0)
+                                        return log_oom();
+                        }
+#ifdef GPT_ROOT_NATIVE
+                        else if (sd_id128_equal(type_id, GPT_ROOT_NATIVE)) {
+
+                                if (root && nr >= root_nr)
+                                        continue;
+
+                                root_nr = nr;
+                                root_rw = !(flags & GPT_FLAG_READ_ONLY);
+
+                                r = free_and_strdup(&root, node);
+                                if (r < 0)
+                                        return log_oom();
+                        }
+#endif
+#ifdef GPT_ROOT_SECONDARY
+                        else if (sd_id128_equal(type_id, GPT_ROOT_SECONDARY)) {
+
+                                if (secondary_root && nr >= secondary_root_nr)
+                                        continue;
+
+                                secondary_root_nr = nr;
+                                secondary_root_rw = !(flags & GPT_FLAG_READ_ONLY);
+
+                                r = free_and_strdup(&secondary_root, node);
+                                if (r < 0)
+                                        return log_oom();
+                        }
+#endif
+                        else if (sd_id128_equal(type_id, GPT_LINUX_GENERIC)) {
+
+                                if (generic)
+                                        multiple_generic = true;
+                                else {
+                                        generic_rw = !(flags & GPT_FLAG_READ_ONLY);
+
+                                        r = free_and_strdup(&generic, node);
+                                        if (r < 0)
+                                                return log_oom();
+                                }
+                        }
+
+                } else if (is_mbr) {
+                        int type;
+
+                        if (flags != 0x80) /* Bootable flag */
+                                continue;
+
+                        type = blkid_partition_get_type(pp);
+                        if (type != 0x83) /* Linux partition */
+                                continue;
+
+                        if (generic)
+                                multiple_generic = true;
+                        else {
+                                generic_rw = true;
+
+                                r = free_and_strdup(&root, node);
+                                if (r < 0)
+                                        return log_oom();
+                        }
+                }
+        }
+
+        if (root) {
+                *root_device = root;
+                root = NULL;
+
+                *root_device_rw = root_rw;
+                *secondary = false;
+        } else if (secondary_root) {
+                *root_device = secondary_root;
+                secondary_root = NULL;
+
+                *root_device_rw = secondary_root_rw;
+                *secondary = true;
+        } else if (generic) {
+
+                /* There were no partitions with precise meanings
+                 * around, but we found generic partitions. In this
+                 * case, if there's only one, we can go ahead and boot
+                 * it, otherwise we bail out, because we really cannot
+                 * make any sense of it. */
+
+                if (multiple_generic) {
+                        log_error("Identified multiple bootable Linux partitions on\n"
+                                  "    %s\n"
+                                  PARTITION_TABLE_BLURB, arg_image);
+                        return -EINVAL;
+                }
+
+                *root_device = generic;
+                generic = NULL;
+
+                *root_device_rw = generic_rw;
+                *secondary = false;
+        } else {
+                log_error("Failed to identify root partition in disk image\n"
+                          "    %s\n"
+                          PARTITION_TABLE_BLURB, arg_image);
+                return -EINVAL;
+        }
+
+        if (home) {
+                *home_device = home;
+                home = NULL;
+
+                *home_device_rw = home_rw;
+        }
+
+        if (srv) {
+                *srv_device = srv;
+                srv = NULL;
+
+                *srv_device_rw = srv_rw;
+        }
+
+        if (esp) {
+                *esp_device = esp;
+                esp = NULL;
+        }
+
+        return 0;
+#else
+        log_error("--image= is not supported, compiled without blkid support.");
+        return -EOPNOTSUPP;
+#endif
+}
+
+static int mount_device(const char *what, const char *where, const char *directory, bool rw) {
+#ifdef HAVE_BLKID
+        _cleanup_blkid_free_probe_ blkid_probe b = NULL;
+        const char *fstype, *p, *options;
+        int r;
+
+        assert(what);
+        assert(where);
+
+        if (arg_read_only)
+                rw = false;
+
+        if (directory)
+                p = strjoina(where, directory);
+        else
+                p = where;
+
+        errno = 0;
+        b = blkid_new_probe_from_filename(what);
+        if (!b) {
+                if (errno == 0)
+                        return log_oom();
+                return log_error_errno(errno, "Failed to allocate prober for %s: %m", what);
+        }
+
+        blkid_probe_enable_superblocks(b, 1);
+        blkid_probe_set_superblocks_flags(b, BLKID_SUBLKS_TYPE);
+
+        errno = 0;
+        r = blkid_do_safeprobe(b);
+        if (r == -1 || r == 1) {
+                log_error("Cannot determine file system type of %s", what);
+                return -EINVAL;
+        } else if (r != 0) {
+                if (errno == 0)
+                        errno = EIO;
+                return log_error_errno(errno, "Failed to probe %s: %m", what);
+        }
+
+        errno = 0;
+        if (blkid_probe_lookup_value(b, "TYPE", &fstype, NULL) < 0) {
+                if (errno == 0)
+                        errno = EINVAL;
+                log_error("Failed to determine file system type of %s", what);
+                return -errno;
+        }
+
+        if (streq(fstype, "crypto_LUKS")) {
+                log_error("nspawn currently does not support LUKS disk images.");
+                return -EOPNOTSUPP;
+        }
+
+        /* If this is a loopback device then let's mount the image with discard, so that the underlying file remains
+         * sparse when possible. */
+        if (STR_IN_SET(fstype, "btrfs", "ext4", "vfat", "xfs")) {
+                const char *l;
+
+                l = path_startswith(what, "/dev");
+                if (l && startswith(l, "loop"))
+                        options = "discard";
+        }
+
+        return mount_verbose(LOG_ERR, what, p, fstype, MS_NODEV|(rw ? 0 : MS_RDONLY), options);
+#else
+        log_error("--image= is not supported, compiled without blkid support.");
+        return -EOPNOTSUPP;
+#endif
+}
+
+static int setup_machine_id(const char *directory) {
+        const char *etc_machine_id;
+        sd_id128_t id;
+        int r;
+
+        /* If the UUID in the container is already set, then that's what counts, and we use. If it isn't set, and the
+         * caller passed --uuid=, then we'll pass it in the $container_uuid env var to PID 1 of the container. The
+         * assumption is that PID 1 will then write it to /etc/machine-id to make it persistent. If --uuid= is not
+         * passed we generate a random UUID, and pass it via $container_uuid. In effect this means that /etc/machine-id
+         * in the container and our idea of the container UUID will always be in sync (at least if PID 1 in the
+         * container behaves nicely). */
+
+        etc_machine_id = prefix_roota(directory, "/etc/machine-id");
+
+        r = id128_read(etc_machine_id, ID128_PLAIN, &id);
+        if (r < 0) {
+                if (!IN_SET(r, -ENOENT, -ENOMEDIUM)) /* If the file is missing or empty, we don't mind */
+                        return log_error_errno(r, "Failed to read machine ID from container image: %m");
+
+                if (sd_id128_is_null(arg_uuid)) {
+                        r = sd_id128_randomize(&arg_uuid);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to acquire randomized machine UUID: %m");
+                }
+        } else {
+                if (sd_id128_is_null(id)) {
+                        log_error("Machine ID in container image is zero, refusing.");
+                        return -EINVAL;
+                }
+
+                arg_uuid = id;
+        }
+
+        return 0;
+}
+
+static int recursive_chown(const char *directory, uid_t shift, uid_t range) {
+        int r;
+
+        assert(directory);
+
+        if (arg_userns_mode == USER_NAMESPACE_NO || !arg_userns_chown)
+                return 0;
+
+        r = path_patch_uid(directory, arg_uid_shift, arg_uid_range);
+        if (r == -EOPNOTSUPP)
+                return log_error_errno(r, "Automatic UID/GID adjusting is only supported for UID/GID ranges starting at multiples of 2^16 with a range of 2^16.");
+        if (r == -EBADE)
+                return log_error_errno(r, "Upper 16 bits of root directory UID and GID do not match.");
+        if (r < 0)
+                return log_error_errno(r, "Failed to adjust UID/GID shift of OS tree: %m");
+        if (r == 0)
+                log_debug("Root directory of image is already owned by the right UID/GID range, skipping recursive chown operation.");
+        else
+                log_debug("Patched directory tree to match UID/GID range.");
+
+        return r;
+}
+
+static int mount_devices(
+                const char *where,
+                const char *root_device, bool root_device_rw,
+                const char *home_device, bool home_device_rw,
+                const char *srv_device, bool srv_device_rw,
+                const char *esp_device) {
+        int r;
+
+        assert(where);
+
+        if (root_device) {
+                r = mount_device(root_device, arg_directory, NULL, root_device_rw);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to mount root directory: %m");
+        }
+
+        if (home_device) {
+                r = mount_device(home_device, arg_directory, "/home", home_device_rw);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to mount home directory: %m");
+        }
+
+        if (srv_device) {
+                r = mount_device(srv_device, arg_directory, "/srv", srv_device_rw);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to mount server data directory: %m");
+        }
+
+        if (esp_device) {
+                const char *mp, *x;
+
+                /* Mount the ESP to /efi if it exists and is empty. If it doesn't exist, use /boot instead. */
+
+                mp = "/efi";
+                x = strjoina(arg_directory, mp);
+                r = dir_is_empty(x);
+                if (r == -ENOENT) {
+                        mp = "/boot";
+                        x = strjoina(arg_directory, mp);
+                        r = dir_is_empty(x);
+                }
+
+                if (r > 0) {
+                        r = mount_device(esp_device, arg_directory, mp, true);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to  mount ESP: %m");
+                }
+        }
+
+        return 0;
+}
+
+static void loop_remove(int nr, int *image_fd) {
+        _cleanup_close_ int control = -1;
+        int r;
+
+        if (nr < 0)
+                return;
+
+        if (image_fd && *image_fd >= 0) {
+                r = ioctl(*image_fd, LOOP_CLR_FD);
+                if (r < 0)
+                        log_debug_errno(errno, "Failed to close loop image: %m");
+                *image_fd = safe_close(*image_fd);
+        }
+
+        control = open("/dev/loop-control", O_RDWR|O_CLOEXEC|O_NOCTTY|O_NONBLOCK);
+        if (control < 0) {
+                log_warning_errno(errno, "Failed to open /dev/loop-control: %m");
+                return;
+        }
+
+        r = ioctl(control, LOOP_CTL_REMOVE, nr);
+        if (r < 0)
+                log_debug_errno(errno, "Failed to remove loop %d: %m", nr);
+}
+
+/*
+ * Return values:
+ * < 0 : wait_for_terminate() failed to get the state of the
+ *       container, the container was terminated by a signal, or
+ *       failed for an unknown reason.  No change is made to the
+ *       container argument.
+ * > 0 : The program executed in the container terminated with an
+ *       error.  The exit code of the program executed in the
+ *       container is returned.  The container argument has been set
+ *       to CONTAINER_TERMINATED.
+ *   0 : The container is being rebooted, has been shut down or exited
+ *       successfully.  The container argument has been set to either
+ *       CONTAINER_TERMINATED or CONTAINER_REBOOTED.
+ *
+ * That is, success is indicated by a return value of zero, and an
+ * error is indicated by a non-zero value.
+ */
+static int wait_for_container(pid_t pid, ContainerStatus *container) {
+        siginfo_t status;
+        int r;
+
+        r = wait_for_terminate(pid, &status);
+        if (r < 0)
+                return log_warning_errno(r, "Failed to wait for container: %m");
+
+        switch (status.si_code) {
+
+        case CLD_EXITED:
+                if (status.si_status == 0)
+                        log_full(arg_quiet ? LOG_DEBUG : LOG_INFO, "Container %s exited successfully.", arg_machine);
+                else
+                        log_full(arg_quiet ? LOG_DEBUG : LOG_INFO, "Container %s failed with error code %i.", arg_machine, status.si_status);
+
+                *container = CONTAINER_TERMINATED;
+                return status.si_status;
+
+        case CLD_KILLED:
+                if (status.si_status == SIGINT) {
+                        log_full(arg_quiet ? LOG_DEBUG : LOG_INFO, "Container %s has been shut down.", arg_machine);
+                        *container = CONTAINER_TERMINATED;
+                        return 0;
+
+                } else if (status.si_status == SIGHUP) {
+                        log_full(arg_quiet ? LOG_DEBUG : LOG_INFO, "Container %s is being rebooted.", arg_machine);
+                        *container = CONTAINER_REBOOTED;
+                        return 0;
+                }
+
+                /* CLD_KILLED fallthrough */
+
+        case CLD_DUMPED:
+                log_error("Container %s terminated by signal %s.", arg_machine, signal_to_string(status.si_status));
+                return -EIO;
+
+        default:
+                log_error("Container %s failed due to unknown reason.", arg_machine);
+                return -EIO;
+        }
+}
+
+static int on_orderly_shutdown(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) {
+        pid_t pid;
+
+        pid = PTR_TO_PID(userdata);
+        if (pid > 0) {
+                if (kill(pid, arg_kill_signal) >= 0) {
+                        log_info("Trying to halt container. Send SIGTERM again to trigger immediate termination.");
+                        sd_event_source_set_userdata(s, NULL);
+                        return 0;
+                }
+        }
+
+        sd_event_exit(sd_event_source_get_event(s), 0);
+        return 0;
+}
+
+static int determine_names(void) {
+        int r;
+
+        if (arg_template && !arg_directory && arg_machine) {
+
+                /* If --template= was specified then we should not
+                 * search for a machine, but instead create a new one
+                 * in /var/lib/machine. */
+
+                arg_directory = strjoin("/var/lib/machines/", arg_machine, NULL);
+                if (!arg_directory)
+                        return log_oom();
+        }
+
+        if (!arg_image && !arg_directory) {
+                if (arg_machine) {
+                        _cleanup_(image_unrefp) Image *i = NULL;
+
+                        r = image_find(arg_machine, &i);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to find image for machine '%s': %m", arg_machine);
+                        else if (r == 0) {
+                                log_error("No image for machine '%s': %m", arg_machine);
+                                return -ENOENT;
+                        }
+
+                        if (i->type == IMAGE_RAW)
+                                r = free_and_strdup(&arg_image, i->path);
+                        else
+                                r = free_and_strdup(&arg_directory, i->path);
+                        if (r < 0)
+                                return log_error_errno(r, "Invalid image directory: %m");
+
+                        if (!arg_ephemeral)
+                                arg_read_only = arg_read_only || i->read_only;
+                } else
+                        arg_directory = get_current_dir_name();
+
+                if (!arg_directory && !arg_machine) {
+                        log_error("Failed to determine path, please use -D or -i.");
+                        return -EINVAL;
+                }
+        }
+
+        if (!arg_machine) {
+                if (arg_directory && path_equal(arg_directory, "/"))
+                        arg_machine = gethostname_malloc();
+                else
+                        arg_machine = strdup(basename(arg_image ?: arg_directory));
+
+                if (!arg_machine)
+                        return log_oom();
+
+                hostname_cleanup(arg_machine);
+                if (!machine_name_is_valid(arg_machine)) {
+                        log_error("Failed to determine machine name automatically, please use -M.");
+                        return -EINVAL;
+                }
+
+                if (arg_ephemeral) {
+                        char *b;
+
+                        /* Add a random suffix when this is an
+                         * ephemeral machine, so that we can run many
+                         * instances at once without manually having
+                         * to specify -M each time. */
+
+                        if (asprintf(&b, "%s-%016" PRIx64, arg_machine, random_u64()) < 0)
+                                return log_oom();
+
+                        free(arg_machine);
+                        arg_machine = b;
+                }
+        }
+
+        return 0;
+}
+
+static int determine_uid_shift(const char *directory) {
+        int r;
+
+        if (arg_userns_mode == USER_NAMESPACE_NO) {
+                arg_uid_shift = 0;
+                return 0;
+        }
+
+        if (arg_uid_shift == UID_INVALID) {
+                struct stat st;
+
+                r = stat(directory, &st);
+                if (r < 0)
+                        return log_error_errno(errno, "Failed to determine UID base of %s: %m", directory);
+
+                arg_uid_shift = st.st_uid & UINT32_C(0xffff0000);
+
+                if (arg_uid_shift != (st.st_gid & UINT32_C(0xffff0000))) {
+                        log_error("UID and GID base of %s don't match.", directory);
+                        return -EINVAL;
+                }
+
+                arg_uid_range = UINT32_C(0x10000);
+        }
+
+        if (arg_uid_shift > (uid_t) -1 - arg_uid_range) {
+                log_error("UID base too high for UID range.");
+                return -EINVAL;
+        }
+
+        return 0;
+}
+
+static int inner_child(
+                Barrier *barrier,
+                const char *directory,
+                bool secondary,
+                int kmsg_socket,
+                int rtnl_socket,
+                FDSet *fds) {
+
+        _cleanup_free_ char *home = NULL;
+        char as_uuid[37];
+        unsigned n_env = 1;
+        const char *envp[] = {
+                "PATH=" DEFAULT_PATH_SPLIT_USR,
+                NULL, /* container */
+                NULL, /* TERM */
+                NULL, /* HOME */
+                NULL, /* USER */
+                NULL, /* LOGNAME */
+                NULL, /* container_uuid */
+                NULL, /* LISTEN_FDS */
+                NULL, /* LISTEN_PID */
+                NULL, /* NOTIFY_SOCKET */
+                NULL
+        };
+
+        _cleanup_strv_free_ char **env_use = NULL;
+        int r;
+
+        assert(barrier);
+        assert(directory);
+        assert(kmsg_socket >= 0);
+
+        cg_unified_flush();
+
+        if (arg_userns_mode != USER_NAMESPACE_NO) {
+                /* Tell the parent, that it now can write the UID map. */
+                (void) barrier_place(barrier); /* #1 */
+
+                /* Wait until the parent wrote the UID map */
+                if (!barrier_place_and_sync(barrier)) { /* #2 */
+                        log_error("Parent died too early");
+                        return -ESRCH;
+                }
+        }
+
+        r = reset_uid_gid();
+        if (r < 0)
+                return log_error_errno(r, "Couldn't become new root: %m");
+
+        r = mount_all(NULL,
+                      arg_userns_mode != USER_NAMESPACE_NO,
+                      true,
+                      arg_private_network,
+                      arg_uid_shift,
+                      arg_uid_range,
+                      arg_selinux_apifs_context);
+
+        if (r < 0)
+                return r;
+
+        r = mount_sysfs(NULL);
+        if (r < 0)
+                return r;
+
+        /* Wait until we are cgroup-ified, so that we
+         * can mount the right cgroup path writable */
+        if (!barrier_place_and_sync(barrier)) { /* #3 */
+                log_error("Parent died too early");
+                return -ESRCH;
+        }
+
+        if (arg_use_cgns && cg_ns_supported()) {
+                r = unshare(CLONE_NEWCGROUP);
+                if (r < 0)
+                        return log_error_errno(errno, "Failed to unshare cgroup namespace");
+                r = mount_cgroups(
+                                "",
+                                arg_unified_cgroup_hierarchy,
+                                arg_userns_mode != USER_NAMESPACE_NO,
+                                arg_uid_shift,
+                                arg_uid_range,
+                                arg_selinux_apifs_context,
+                                true);
+                if (r < 0)
+                        return r;
+        } else {
+                r = mount_systemd_cgroup_writable("", arg_unified_cgroup_hierarchy);
+                if (r < 0)
+                        return r;
+        }
+
+        r = setup_boot_id(NULL);
+        if (r < 0)
+                return r;
+
+        r = setup_kmsg(NULL, kmsg_socket);
+        if (r < 0)
+                return r;
+        kmsg_socket = safe_close(kmsg_socket);
+
+        umask(0022);
+
+        if (setsid() < 0)
+                return log_error_errno(errno, "setsid() failed: %m");
+
+        if (arg_private_network)
+                loopback_setup();
+
+        if (arg_expose_ports) {
+                r = expose_port_send_rtnl(rtnl_socket);
+                if (r < 0)
+                        return r;
+                rtnl_socket = safe_close(rtnl_socket);
+        }
+
+        r = drop_capabilities();
+        if (r < 0)
+                return log_error_errno(r, "drop_capabilities() failed: %m");
+
+        setup_hostname();
+
+        if (arg_personality != PERSONALITY_INVALID) {
+                if (personality(arg_personality) < 0)
+                        return log_error_errno(errno, "personality() failed: %m");
+        } else if (secondary) {
+                if (personality(PER_LINUX32) < 0)
+                        return log_error_errno(errno, "personality() failed: %m");
+        }
+
+#ifdef HAVE_SELINUX
+        if (arg_selinux_context)
+                if (setexeccon(arg_selinux_context) < 0)
+                        return log_error_errno(errno, "setexeccon(\"%s\") failed: %m", arg_selinux_context);
+#endif
+
+        r = change_uid_gid(arg_user, &home);
+        if (r < 0)
+                return r;
+
+        /* LXC sets container=lxc, so follow the scheme here */
+        envp[n_env++] = strjoina("container=", arg_container_service_name);
+
+        envp[n_env] = strv_find_prefix(environ, "TERM=");
+        if (envp[n_env])
+                n_env++;
+
+        if ((asprintf((char**)(envp + n_env++), "HOME=%s", home ? home: "/root") < 0) ||
+            (asprintf((char**)(envp + n_env++), "USER=%s", arg_user ? arg_user : "root") < 0) ||
+            (asprintf((char**)(envp + n_env++), "LOGNAME=%s", arg_user ? arg_user : "root") < 0))
+                return log_oom();
+
+        assert(!sd_id128_is_null(arg_uuid));
+
+        if (asprintf((char**)(envp + n_env++), "container_uuid=%s", id128_to_uuid_string(arg_uuid, as_uuid)) < 0)
+                return log_oom();
+
+        if (fdset_size(fds) > 0) {
+                r = fdset_cloexec(fds, false);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to unset O_CLOEXEC for file descriptors.");
+
+                if ((asprintf((char **)(envp + n_env++), "LISTEN_FDS=%u", fdset_size(fds)) < 0) ||
+                    (asprintf((char **)(envp + n_env++), "LISTEN_PID=1") < 0))
+                        return log_oom();
+        }
+        if (asprintf((char **)(envp + n_env++), "NOTIFY_SOCKET=%s", NSPAWN_NOTIFY_SOCKET_PATH) < 0)
+                return log_oom();
+
+        env_use = strv_env_merge(2, envp, arg_setenv);
+        if (!env_use)
+                return log_oom();
+
+        /* Let the parent know that we are ready and
+         * wait until the parent is ready with the
+         * setup, too... */
+        if (!barrier_place_and_sync(barrier)) { /* #4 */
+                log_error("Parent died too early");
+                return -ESRCH;
+        }
+
+        if (arg_chdir)
+                if (chdir(arg_chdir) < 0)
+                        return log_error_errno(errno, "Failed to change to specified working directory %s: %m", arg_chdir);
+
+        if (arg_start_mode == START_PID2) {
+                r = stub_pid1();
+                if (r < 0)
+                        return r;
+        }
+
+        /* Now, explicitly close the log, so that we
+         * then can close all remaining fds. Closing
+         * the log explicitly first has the benefit
+         * that the logging subsystem knows about it,
+         * and is thus ready to be reopened should we
+         * need it again. Note that the other fds
+         * closed here are at least the locking and
+         * barrier fds. */
+        log_close();
+        (void) fdset_close_others(fds);
+
+        if (arg_start_mode == START_BOOT) {
+                char **a;
+                size_t m;
+
+                /* Automatically search for the init system */
+
+                m = strv_length(arg_parameters);
+                a = newa(char*, m + 2);
+                memcpy_safe(a + 1, arg_parameters, m * sizeof(char*));
+                a[1 + m] = NULL;
+
+                a[0] = (char*) "/usr/lib/systemd/systemd";
+                execve(a[0], a, env_use);
+
+                a[0] = (char*) "/lib/systemd/systemd";
+                execve(a[0], a, env_use);
+
+                a[0] = (char*) "/sbin/init";
+                execve(a[0], a, env_use);
+        } else if (!strv_isempty(arg_parameters))
+                execvpe(arg_parameters[0], arg_parameters, env_use);
+        else {
+                if (!arg_chdir)
+                        /* If we cannot change the directory, we'll end up in /, that is expected. */
+                        (void) chdir(home ?: "/root");
+
+                execle("/bin/bash", "-bash", NULL, env_use);
+                execle("/bin/sh", "-sh", NULL, env_use);
+        }
+
+        r = -errno;
+        (void) log_open();
+        return log_error_errno(r, "execv() failed: %m");
+}
+
+static int setup_sd_notify_child(void) {
+        static const int one = 1;
+        int fd = -1;
+        union sockaddr_union sa = {
+                .sa.sa_family = AF_UNIX,
+        };
+        int r;
+
+        fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
+        if (fd < 0)
+                return log_error_errno(errno, "Failed to allocate notification socket: %m");
+
+        (void) mkdir_parents(NSPAWN_NOTIFY_SOCKET_PATH, 0755);
+        (void) unlink(NSPAWN_NOTIFY_SOCKET_PATH);
+
+        strncpy(sa.un.sun_path, NSPAWN_NOTIFY_SOCKET_PATH, sizeof(sa.un.sun_path)-1);
+        r = bind(fd, &sa.sa, SOCKADDR_UN_LEN(sa.un));
+        if (r < 0) {
+                safe_close(fd);
+                return log_error_errno(errno, "bind(%s) failed: %m", sa.un.sun_path);
+        }
+
+        r = setsockopt(fd, SOL_SOCKET, SO_PASSCRED, &one, sizeof(one));
+        if (r < 0) {
+                safe_close(fd);
+                return log_error_errno(errno, "SO_PASSCRED failed: %m");
+        }
+
+        return fd;
+}
+
+static int outer_child(
+                Barrier *barrier,
+                const char *directory,
+                const char *console,
+                const char *root_device, bool root_device_rw,
+                const char *home_device, bool home_device_rw,
+                const char *srv_device, bool srv_device_rw,
+                const char *esp_device,
+                bool interactive,
+                bool secondary,
+                int pid_socket,
+                int uuid_socket,
+                int notify_socket,
+                int kmsg_socket,
+                int rtnl_socket,
+                int uid_shift_socket,
+                FDSet *fds) {
+
+        pid_t pid;
+        ssize_t l;
+        int r;
+        _cleanup_close_ int fd = -1;
+
+        assert(barrier);
+        assert(directory);
+        assert(console);
+        assert(pid_socket >= 0);
+        assert(uuid_socket >= 0);
+        assert(notify_socket >= 0);
+        assert(kmsg_socket >= 0);
+
+        cg_unified_flush();
+
+        if (prctl(PR_SET_PDEATHSIG, SIGKILL) < 0)
+                return log_error_errno(errno, "PR_SET_PDEATHSIG failed: %m");
+
+        if (interactive) {
+                close_nointr(STDIN_FILENO);
+                close_nointr(STDOUT_FILENO);
+                close_nointr(STDERR_FILENO);
+
+                r = open_terminal(console, O_RDWR);
+                if (r != STDIN_FILENO) {
+                        if (r >= 0) {
+                                safe_close(r);
+                                r = -EINVAL;
+                        }
+
+                        return log_error_errno(r, "Failed to open console: %m");
+                }
+
+                if (dup2(STDIN_FILENO, STDOUT_FILENO) != STDOUT_FILENO ||
+                    dup2(STDIN_FILENO, STDERR_FILENO) != STDERR_FILENO)
+                        return log_error_errno(errno, "Failed to duplicate console: %m");
+        }
+
+        r = reset_audit_loginuid();
+        if (r < 0)
+                return r;
+
+        /* Mark everything as slave, so that we still
+         * receive mounts from the real root, but don't
+         * propagate mounts to the real root. */
+        r = mount_verbose(LOG_ERR, NULL, "/", NULL, MS_SLAVE|MS_REC, NULL);
+        if (r < 0)
+                return r;
+
+        r = mount_devices(directory,
+                          root_device, root_device_rw,
+                          home_device, home_device_rw,
+                          srv_device, srv_device_rw,
+                          esp_device);
+        if (r < 0)
+                return r;
+
+        r = determine_uid_shift(directory);
+        if (r < 0)
+                return r;
+
+        r = detect_unified_cgroup_hierarchy(directory);
+        if (r < 0)
+                return r;
+
+        if (arg_userns_mode != USER_NAMESPACE_NO) {
+                /* Let the parent know which UID shift we read from the image */
+                l = send(uid_shift_socket, &arg_uid_shift, sizeof(arg_uid_shift), MSG_NOSIGNAL);
+                if (l < 0)
+                        return log_error_errno(errno, "Failed to send UID shift: %m");
+                if (l != sizeof(arg_uid_shift)) {
+                        log_error("Short write while sending UID shift.");
+                        return -EIO;
+                }
+
+                if (arg_userns_mode == USER_NAMESPACE_PICK) {
+                        /* When we are supposed to pick the UID shift, the parent will check now whether the UID shift
+                         * we just read from the image is available. If yes, it will send the UID shift back to us, if
+                         * not it will pick a different one, and send it back to us. */
+
+                        l = recv(uid_shift_socket, &arg_uid_shift, sizeof(arg_uid_shift), 0);
+                        if (l < 0)
+                                return log_error_errno(errno, "Failed to recv UID shift: %m");
+                        if (l != sizeof(arg_uid_shift)) {
+                                log_error("Short read while receiving UID shift.");
+                                return -EIO;
+                        }
+                }
+
+                log_info("Selected user namespace base " UID_FMT " and range " UID_FMT ".", arg_uid_shift, arg_uid_range);
+        }
+
+        /* Turn directory into bind mount */
+        r = mount_verbose(LOG_ERR, directory, directory, NULL, MS_BIND|MS_REC, NULL);
+        if (r < 0)
+                return r;
+
+        /* Mark everything as shared so our mounts get propagated down. This is
+         * required to make new bind mounts available in systemd services
+         * inside the containter that create a new mount namespace.
+         * See https://github.com/systemd/systemd/issues/3860
+         * Further submounts (such as /dev) done after this will inherit the
+         * shared propagation mode.*/
+        r = mount_verbose(LOG_ERR, NULL, directory, NULL, MS_SHARED|MS_REC, NULL);
+        if (r < 0)
+                return r;
+
+        r = recursive_chown(directory, arg_uid_shift, arg_uid_range);
+        if (r < 0)
+                return r;
+
+        r = setup_volatile(
+                        directory,
+                        arg_volatile_mode,
+                        arg_userns_mode != USER_NAMESPACE_NO,
+                        arg_uid_shift,
+                        arg_uid_range,
+                        arg_selinux_context);
+        if (r < 0)
+                return r;
+
+        r = setup_volatile_state(
+                        directory,
+                        arg_volatile_mode,
+                        arg_userns_mode != USER_NAMESPACE_NO,
+                        arg_uid_shift,
+                        arg_uid_range,
+                        arg_selinux_context);
+        if (r < 0)
+                return r;
+
+        r = base_filesystem_create(directory, arg_uid_shift, (gid_t) arg_uid_shift);
+        if (r < 0)
+                return r;
+
+        if (arg_read_only) {
+                r = bind_remount_recursive(directory, true, NULL);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to make tree read-only: %m");
+        }
+
+        r = mount_all(directory,
+                      arg_userns_mode != USER_NAMESPACE_NO,
+                      false,
+                      arg_private_network,
+                      arg_uid_shift,
+                      arg_uid_range,
+                      arg_selinux_apifs_context);
+        if (r < 0)
+                return r;
+
+        r = copy_devnodes(directory);
+        if (r < 0)
+                return r;
+
+        dev_setup(directory, arg_uid_shift, arg_uid_shift);
+
+        r = setup_pts(directory);
+        if (r < 0)
+                return r;
+
+        r = setup_propagate(directory);
+        if (r < 0)
+                return r;
+
+        r = setup_dev_console(directory, console);
+        if (r < 0)
+                return r;
+
+        r = setup_seccomp(arg_caps_retain);
+        if (r < 0)
+                return r;
+
+        r = setup_timezone(directory);
+        if (r < 0)
+                return r;
+
+        r = setup_resolv_conf(directory);
+        if (r < 0)
+                return r;
+
+        r = setup_machine_id(directory);
+        if (r < 0)
+                return r;
+
+        r = setup_journal(directory);
+        if (r < 0)
+                return r;
+
+        r = mount_custom(
+                        directory,
+                        arg_custom_mounts,
+                        arg_n_custom_mounts,
+                        arg_userns_mode != USER_NAMESPACE_NO,
+                        arg_uid_shift,
+                        arg_uid_range,
+                        arg_selinux_apifs_context);
+        if (r < 0)
+                return r;
+
+        if (!arg_use_cgns || !cg_ns_supported()) {
+                r = mount_cgroups(
+                                directory,
+                                arg_unified_cgroup_hierarchy,
+                                arg_userns_mode != USER_NAMESPACE_NO,
+                                arg_uid_shift,
+                                arg_uid_range,
+                                arg_selinux_apifs_context,
+                                false);
+                if (r < 0)
+                        return r;
+        }
+
+        r = mount_move_root(directory);
+        if (r < 0)
+                return log_error_errno(r, "Failed to move root directory: %m");
+
+        fd = setup_sd_notify_child();
+        if (fd < 0)
+                return fd;
+
+        pid = raw_clone(SIGCHLD|CLONE_NEWNS|
+                        arg_clone_ns_flags |
+                        (arg_private_network ? CLONE_NEWNET : 0) |
+                        (arg_userns_mode != USER_NAMESPACE_NO ? CLONE_NEWUSER : 0));
+        if (pid < 0)
+                return log_error_errno(errno, "Failed to fork inner child: %m");
+        if (pid == 0) {
+                pid_socket = safe_close(pid_socket);
+                uuid_socket = safe_close(uuid_socket);
+                notify_socket = safe_close(notify_socket);
+                uid_shift_socket = safe_close(uid_shift_socket);
+
+                /* The inner child has all namespaces that are
+                 * requested, so that we all are owned by the user if
+                 * user namespaces are turned on. */
+
+                r = inner_child(barrier, directory, secondary, kmsg_socket, rtnl_socket, fds);
+                if (r < 0)
+                        _exit(EXIT_FAILURE);
+
+                _exit(EXIT_SUCCESS);
+        }
+
+        l = send(pid_socket, &pid, sizeof(pid), MSG_NOSIGNAL);
+        if (l < 0)
+                return log_error_errno(errno, "Failed to send PID: %m");
+        if (l != sizeof(pid)) {
+                log_error("Short write while sending PID.");
+                return -EIO;
+        }
+
+        l = send(uuid_socket, &arg_uuid, sizeof(arg_uuid), MSG_NOSIGNAL);
+        if (l < 0)
+                return log_error_errno(errno, "Failed to send machine ID: %m");
+        if (l != sizeof(arg_uuid)) {
+                log_error("Short write while sending machine ID.");
+                return -EIO;
+        }
+
+        l = send_one_fd(notify_socket, fd, 0);
+        if (l < 0)
+                return log_error_errno(errno, "Failed to send notify fd: %m");
+
+        pid_socket = safe_close(pid_socket);
+        uuid_socket = safe_close(uuid_socket);
+        notify_socket = safe_close(notify_socket);
+        kmsg_socket = safe_close(kmsg_socket);
+        rtnl_socket = safe_close(rtnl_socket);
+
+        return 0;
+}
+
+static int uid_shift_pick(uid_t *shift, LockFile *ret_lock_file) {
+        unsigned n_tries = 100;
+        uid_t candidate;
+        int r;
+
+        assert(shift);
+        assert(ret_lock_file);
+        assert(arg_userns_mode == USER_NAMESPACE_PICK);
+        assert(arg_uid_range == 0x10000U);
+
+        candidate = *shift;
+
+        (void) mkdir("/run/systemd/nspawn-uid", 0755);
+
+        for (;;) {
+                char lock_path[strlen("/run/systemd/nspawn-uid/") + DECIMAL_STR_MAX(uid_t) + 1];
+                _cleanup_release_lock_file_ LockFile lf = LOCK_FILE_INIT;
+
+                if (--n_tries <= 0)
+                        return -EBUSY;
+
+                if (candidate < UID_SHIFT_PICK_MIN || candidate > UID_SHIFT_PICK_MAX)
+                        goto next;
+                if ((candidate & UINT32_C(0xFFFF)) != 0)
+                        goto next;
+
+                xsprintf(lock_path, "/run/systemd/nspawn-uid/" UID_FMT, candidate);
+                r = make_lock_file(lock_path, LOCK_EX|LOCK_NB, &lf);
+                if (r == -EBUSY) /* Range already taken by another nspawn instance */
+                        goto next;
+                if (r < 0)
+                        return r;
+
+                /* Make some superficial checks whether the range is currently known in the user database */
+                if (getpwuid(candidate))
+                        goto next;
+                if (getpwuid(candidate + UINT32_C(0xFFFE)))
+                        goto next;
+                if (getgrgid(candidate))
+                        goto next;
+                if (getgrgid(candidate + UINT32_C(0xFFFE)))
+                        goto next;
+
+                *ret_lock_file = lf;
+                lf = (struct LockFile) LOCK_FILE_INIT;
+                *shift = candidate;
+                return 0;
+
+        next:
+                random_bytes(&candidate, sizeof(candidate));
+                candidate = (candidate % (UID_SHIFT_PICK_MAX - UID_SHIFT_PICK_MIN)) + UID_SHIFT_PICK_MIN;
+                candidate &= (uid_t) UINT32_C(0xFFFF0000);
+        }
+}
+
+static int setup_uid_map(pid_t pid) {
+        char uid_map[strlen("/proc//uid_map") + DECIMAL_STR_MAX(uid_t) + 1], line[DECIMAL_STR_MAX(uid_t)*3+3+1];
+        int r;
+
+        assert(pid > 1);
+
+        xsprintf(uid_map, "/proc/" PID_FMT "/uid_map", pid);
+        xsprintf(line, UID_FMT " " UID_FMT " " UID_FMT "\n", 0, arg_uid_shift, arg_uid_range);
+        r = write_string_file(uid_map, line, 0);
+        if (r < 0)
+                return log_error_errno(r, "Failed to write UID map: %m");
+
+        /* We always assign the same UID and GID ranges */
+        xsprintf(uid_map, "/proc/" PID_FMT "/gid_map", pid);
+        r = write_string_file(uid_map, line, 0);
+        if (r < 0)
+                return log_error_errno(r, "Failed to write GID map: %m");
+
+        return 0;
+}
+
+static int nspawn_dispatch_notify_fd(sd_event_source *source, int fd, uint32_t revents, void *userdata) {
+        char buf[NOTIFY_BUFFER_MAX+1];
+        char *p = NULL;
+        struct iovec iovec = {
+                .iov_base = buf,
+                .iov_len = sizeof(buf)-1,
+        };
+        union {
+                struct cmsghdr cmsghdr;
+                uint8_t buf[CMSG_SPACE(sizeof(struct ucred)) +
+                            CMSG_SPACE(sizeof(int) * NOTIFY_FD_MAX)];
+        } control = {};
+        struct msghdr msghdr = {
+                .msg_iov = &iovec,
+                .msg_iovlen = 1,
+                .msg_control = &control,
+                .msg_controllen = sizeof(control),
+        };
+        struct cmsghdr *cmsg;
+        struct ucred *ucred = NULL;
+        ssize_t n;
+        pid_t inner_child_pid;
+        _cleanup_strv_free_ char **tags = NULL;
+
+        assert(userdata);
+
+        inner_child_pid = PTR_TO_PID(userdata);
+
+        if (revents != EPOLLIN) {
+                log_warning("Got unexpected poll event for notify fd.");
+                return 0;
+        }
+
+        n = recvmsg(fd, &msghdr, MSG_DONTWAIT|MSG_CMSG_CLOEXEC);
+        if (n < 0) {
+                if (errno == EAGAIN || errno == EINTR)
+                        return 0;
+
+                return log_warning_errno(errno, "Couldn't read notification socket: %m");
+        }
+        cmsg_close_all(&msghdr);
+
+        CMSG_FOREACH(cmsg, &msghdr) {
+                if (cmsg->cmsg_level == SOL_SOCKET &&
+                           cmsg->cmsg_type == SCM_CREDENTIALS &&
+                           cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred))) {
+
+                        ucred = (struct ucred*) CMSG_DATA(cmsg);
+                }
+        }
+
+        if (!ucred || ucred->pid != inner_child_pid) {
+                log_warning("Received notify message without valid credentials. Ignoring.");
+                return 0;
+        }
+
+        if ((size_t) n >= sizeof(buf)) {
+                log_warning("Received notify message exceeded maximum size. Ignoring.");
+                return 0;
+        }
+
+        buf[n] = 0;
+        tags = strv_split(buf, "\n\r");
+        if (!tags)
+                return log_oom();
+
+        if (strv_find(tags, "READY=1"))
+                sd_notifyf(false, "READY=1\n");
+
+        p = strv_find_startswith(tags, "STATUS=");
+        if (p)
+                sd_notifyf(false, "STATUS=Container running: %s", p);
+
+        return 0;
+}
+
+static int setup_sd_notify_parent(sd_event *event, int fd, pid_t *inner_child_pid) {
+        int r;
+        sd_event_source *notify_event_source;
+
+        r = sd_event_add_io(event, &notify_event_source, fd, EPOLLIN, nspawn_dispatch_notify_fd, inner_child_pid);
+        if (r < 0)
+                return log_error_errno(r, "Failed to allocate notify event source: %m");
+
+        (void) sd_event_source_set_description(notify_event_source, "nspawn-notify");
+
+        return 0;
+}
+
+static int load_settings(void) {
+        _cleanup_(settings_freep) Settings *settings = NULL;
+        _cleanup_fclose_ FILE *f = NULL;
+        _cleanup_free_ char *p = NULL;
+        const char *fn, *i;
+        int r;
+
+        /* If all settings are masked, there's no point in looking for
+         * the settings file */
+        if ((arg_settings_mask & _SETTINGS_MASK_ALL) == _SETTINGS_MASK_ALL)
+                return 0;
+
+        fn = strjoina(arg_machine, ".nspawn");
+
+        /* We first look in the admin's directories in /etc and /run */
+        FOREACH_STRING(i, "/etc/systemd/nspawn", "/run/systemd/nspawn") {
+                _cleanup_free_ char *j = NULL;
+
+                j = strjoin(i, "/", fn, NULL);
+                if (!j)
+                        return log_oom();
+
+                f = fopen(j, "re");
+                if (f) {
+                        p = j;
+                        j = NULL;
+
+                        /* By default, we trust configuration from /etc and /run */
+                        if (arg_settings_trusted < 0)
+                                arg_settings_trusted = true;
+
+                        break;
+                }
+
+                if (errno != ENOENT)
+                        return log_error_errno(errno, "Failed to open %s: %m", j);
+        }
+
+        if (!f) {
+                /* After that, let's look for a file next to the
+                 * actual image we shall boot. */
+
+                if (arg_image) {
+                        p = file_in_same_dir(arg_image, fn);
+                        if (!p)
+                                return log_oom();
+                } else if (arg_directory) {
+                        p = file_in_same_dir(arg_directory, fn);
+                        if (!p)
+                                return log_oom();
+                }
+
+                if (p) {
+                        f = fopen(p, "re");
+                        if (!f && errno != ENOENT)
+                                return log_error_errno(errno, "Failed to open %s: %m", p);
+
+                        /* By default, we do not trust configuration from /var/lib/machines */
+                        if (arg_settings_trusted < 0)
+                                arg_settings_trusted = false;
+                }
+        }
+
+        if (!f)
+                return 0;
+
+        log_debug("Settings are trusted: %s", yes_no(arg_settings_trusted));
+
+        r = settings_load(f, p, &settings);
+        if (r < 0)
+                return r;
+
+        /* Copy over bits from the settings, unless they have been
+         * explicitly masked by command line switches. */
+
+        if ((arg_settings_mask & SETTING_START_MODE) == 0 &&
+            settings->start_mode >= 0) {
+                arg_start_mode = settings->start_mode;
+
+                strv_free(arg_parameters);
+                arg_parameters = settings->parameters;
+                settings->parameters = NULL;
+        }
+
+        if ((arg_settings_mask & SETTING_WORKING_DIRECTORY) == 0 &&
+            settings->working_directory) {
+                free(arg_chdir);
+                arg_chdir = settings->working_directory;
+                settings->working_directory = NULL;
+        }
+
+        if ((arg_settings_mask & SETTING_ENVIRONMENT) == 0 &&
+            settings->environment) {
+                strv_free(arg_setenv);
+                arg_setenv = settings->environment;
+                settings->environment = NULL;
+        }
+
+        if ((arg_settings_mask & SETTING_USER) == 0 &&
+            settings->user) {
+                free(arg_user);
+                arg_user = settings->user;
+                settings->user = NULL;
+        }
+
+        if ((arg_settings_mask & SETTING_CAPABILITY) == 0) {
+                uint64_t plus;
+
+                plus = settings->capability;
+                if (settings_private_network(settings))
+                        plus |= (1ULL << CAP_NET_ADMIN);
+
+                if (!arg_settings_trusted && plus != 0) {
+                        if (settings->capability != 0)
+                                log_warning("Ignoring Capability= setting, file %s is not trusted.", p);
+                } else
+                        arg_caps_retain |= plus;
+
+                arg_caps_retain &= ~settings->drop_capability;
+        }
+
+        if ((arg_settings_mask & SETTING_KILL_SIGNAL) == 0 &&
+            settings->kill_signal > 0)
+                arg_kill_signal = settings->kill_signal;
+
+        if ((arg_settings_mask & SETTING_PERSONALITY) == 0 &&
+            settings->personality != PERSONALITY_INVALID)
+                arg_personality = settings->personality;
+
+        if ((arg_settings_mask & SETTING_MACHINE_ID) == 0 &&
+            !sd_id128_is_null(settings->machine_id)) {
+
+                if (!arg_settings_trusted)
+                        log_warning("Ignoring MachineID= setting, file %s is not trusted.", p);
+                else
+                        arg_uuid = settings->machine_id;
+        }
+
+        if ((arg_settings_mask & SETTING_READ_ONLY) == 0 &&
+            settings->read_only >= 0)
+                arg_read_only = settings->read_only;
+
+        if ((arg_settings_mask & SETTING_VOLATILE_MODE) == 0 &&
+            settings->volatile_mode != _VOLATILE_MODE_INVALID)
+                arg_volatile_mode = settings->volatile_mode;
+
+        if ((arg_settings_mask & SETTING_CUSTOM_MOUNTS) == 0 &&
+            settings->n_custom_mounts > 0) {
+
+                if (!arg_settings_trusted)
+                        log_warning("Ignoring TemporaryFileSystem=, Bind= and BindReadOnly= settings, file %s is not trusted.", p);
+                else {
+                        custom_mount_free_all(arg_custom_mounts, arg_n_custom_mounts);
+                        arg_custom_mounts = settings->custom_mounts;
+                        arg_n_custom_mounts = settings->n_custom_mounts;
+
+                        settings->custom_mounts = NULL;
+                        settings->n_custom_mounts = 0;
+                }
+        }
+
+        if ((arg_settings_mask & SETTING_NETWORK) == 0 &&
+            (settings->private_network >= 0 ||
+             settings->network_veth >= 0 ||
+             settings->network_bridge ||
+             settings->network_zone ||
+             settings->network_interfaces ||
+             settings->network_macvlan ||
+             settings->network_ipvlan ||
+             settings->network_veth_extra)) {
+
+                if (!arg_settings_trusted)
+                        log_warning("Ignoring network settings, file %s is not trusted.", p);
+                else {
+                        arg_network_veth = settings_network_veth(settings);
+                        arg_private_network = settings_private_network(settings);
+
+                        strv_free(arg_network_interfaces);
+                        arg_network_interfaces = settings->network_interfaces;
+                        settings->network_interfaces = NULL;
+
+                        strv_free(arg_network_macvlan);
+                        arg_network_macvlan = settings->network_macvlan;
+                        settings->network_macvlan = NULL;
+
+                        strv_free(arg_network_ipvlan);
+                        arg_network_ipvlan = settings->network_ipvlan;
+                        settings->network_ipvlan = NULL;
+
+                        strv_free(arg_network_veth_extra);
+                        arg_network_veth_extra = settings->network_veth_extra;
+                        settings->network_veth_extra = NULL;
+
+                        free(arg_network_bridge);
+                        arg_network_bridge = settings->network_bridge;
+                        settings->network_bridge = NULL;
+
+                        free(arg_network_zone);
+                        arg_network_zone = settings->network_zone;
+                        settings->network_zone = NULL;
+                }
+        }
+
+        if ((arg_settings_mask & SETTING_EXPOSE_PORTS) == 0 &&
+            settings->expose_ports) {
+
+                if (!arg_settings_trusted)
+                        log_warning("Ignoring Port= setting, file %s is not trusted.", p);
+                else {
+                        expose_port_free_all(arg_expose_ports);
+                        arg_expose_ports = settings->expose_ports;
+                        settings->expose_ports = NULL;
+                }
+        }
+
+        if ((arg_settings_mask & SETTING_USERNS) == 0 &&
+            settings->userns_mode != _USER_NAMESPACE_MODE_INVALID) {
+
+                if (!arg_settings_trusted)
+                        log_warning("Ignoring PrivateUsers= and PrivateUsersChown= settings, file %s is not trusted.", p);
+                else {
+                        arg_userns_mode = settings->userns_mode;
+                        arg_uid_shift = settings->uid_shift;
+                        arg_uid_range = settings->uid_range;
+                        arg_userns_chown = settings->userns_chown;
+                }
+        }
+
+        if ((arg_settings_mask & SETTING_NOTIFY_READY) == 0)
+                arg_notify_ready = settings->notify_ready;
+
+        return 0;
+}
+
+static int run(int master,
+               const char* console,
+               const char *root_device, bool root_device_rw,
+               const char *home_device, bool home_device_rw,
+               const char *srv_device, bool srv_device_rw,
+               const char *esp_device,
+               bool interactive,
+               bool secondary,
+               FDSet *fds,
+               char veth_name[IFNAMSIZ], bool *veth_created,
+               union in_addr_union *exposed,
+               pid_t *pid, int *ret) {
+
+        static const struct sigaction sa = {
+                .sa_handler = nop_signal_handler,
+                .sa_flags = SA_NOCLDSTOP,
+        };
+
+        _cleanup_release_lock_file_ LockFile uid_shift_lock = LOCK_FILE_INIT;
+        _cleanup_close_ int etc_passwd_lock = -1;
+        _cleanup_close_pair_ int
+                kmsg_socket_pair[2] = { -1, -1 },
+                rtnl_socket_pair[2] = { -1, -1 },
+                pid_socket_pair[2] = { -1, -1 },
+                uuid_socket_pair[2] = { -1, -1 },
+                notify_socket_pair[2] = { -1, -1 },
+                uid_shift_socket_pair[2] = { -1, -1 };
+        _cleanup_close_ int notify_socket= -1;
+        _cleanup_(barrier_destroy) Barrier barrier = BARRIER_NULL;
+        _cleanup_(sd_event_unrefp) sd_event *event = NULL;
+        _cleanup_(pty_forward_freep) PTYForward *forward = NULL;
+        _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL;
+        ContainerStatus container_status = 0;
+        char last_char = 0;
+        int ifi = 0, r;
+        ssize_t l;
+        sigset_t mask_chld;
+
+        assert_se(sigemptyset(&mask_chld) == 0);
+        assert_se(sigaddset(&mask_chld, SIGCHLD) == 0);
+
+        if (arg_userns_mode == USER_NAMESPACE_PICK) {
+                /* When we shall pick the UID/GID range, let's first lock /etc/passwd, so that we can safely
+                 * check with getpwuid() if the specific user already exists. Note that /etc might be
+                 * read-only, in which case this will fail with EROFS. But that's really OK, as in that case we
+                 * can be reasonably sure that no users are going to be added. Note that getpwuid() checks are
+                 * really just an extra safety net. We kinda assume that the UID range we allocate from is
+                 * really ours. */
+
+                etc_passwd_lock = take_etc_passwd_lock(NULL);
+                if (etc_passwd_lock < 0 && etc_passwd_lock != -EROFS)
+                        return log_error_errno(etc_passwd_lock, "Failed to take /etc/passwd lock: %m");
+        }
+
+        r = barrier_create(&barrier);
+        if (r < 0)
+                return log_error_errno(r, "Cannot initialize IPC barrier: %m");
+
+        if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, kmsg_socket_pair) < 0)
+                return log_error_errno(errno, "Failed to create kmsg socket pair: %m");
+
+        if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, rtnl_socket_pair) < 0)
+                return log_error_errno(errno, "Failed to create rtnl socket pair: %m");
+
+        if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, pid_socket_pair) < 0)
+                return log_error_errno(errno, "Failed to create pid socket pair: %m");
+
+        if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, uuid_socket_pair) < 0)
+                return log_error_errno(errno, "Failed to create id socket pair: %m");
+
+        if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, notify_socket_pair) < 0)
+                return log_error_errno(errno, "Failed to create notify socket pair: %m");
+
+        if (arg_userns_mode != USER_NAMESPACE_NO)
+                if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, uid_shift_socket_pair) < 0)
+                        return log_error_errno(errno, "Failed to create uid shift socket pair: %m");
+
+        /* Child can be killed before execv(), so handle SIGCHLD in order to interrupt
+         * parent's blocking calls and give it a chance to call wait() and terminate. */
+        r = sigprocmask(SIG_UNBLOCK, &mask_chld, NULL);
+        if (r < 0)
+                return log_error_errno(errno, "Failed to change the signal mask: %m");
+
+        r = sigaction(SIGCHLD, &sa, NULL);
+        if (r < 0)
+                return log_error_errno(errno, "Failed to install SIGCHLD handler: %m");
+
+        *pid = raw_clone(SIGCHLD|CLONE_NEWNS);
+        if (*pid < 0)
+                return log_error_errno(errno, "clone() failed%s: %m",
+                                       errno == EINVAL ?
+                                       ", do you have namespace support enabled in your kernel? (You need UTS, IPC, PID and NET namespacing built in)" : "");
+
+        if (*pid == 0) {
+                /* The outer child only has a file system namespace. */
+                barrier_set_role(&barrier, BARRIER_CHILD);
+
+                master = safe_close(master);
+
+                kmsg_socket_pair[0] = safe_close(kmsg_socket_pair[0]);
+                rtnl_socket_pair[0] = safe_close(rtnl_socket_pair[0]);
+                pid_socket_pair[0] = safe_close(pid_socket_pair[0]);
+                uuid_socket_pair[0] = safe_close(uuid_socket_pair[0]);
+                notify_socket_pair[0] = safe_close(notify_socket_pair[0]);
+                uid_shift_socket_pair[0] = safe_close(uid_shift_socket_pair[0]);
+
+                (void) reset_all_signal_handlers();
+                (void) reset_signal_mask();
+
+                r = outer_child(&barrier,
+                                arg_directory,
+                                console,
+                                root_device, root_device_rw,
+                                home_device, home_device_rw,
+                                srv_device, srv_device_rw,
+                                esp_device,
+                                interactive,
+                                secondary,
+                                pid_socket_pair[1],
+                                uuid_socket_pair[1],
+                                notify_socket_pair[1],
+                                kmsg_socket_pair[1],
+                                rtnl_socket_pair[1],
+                                uid_shift_socket_pair[1],
+                                fds);
+                if (r < 0)
+                        _exit(EXIT_FAILURE);
+
+                _exit(EXIT_SUCCESS);
+        }
+
+        barrier_set_role(&barrier, BARRIER_PARENT);
+
+        fds = fdset_free(fds);
+
+        kmsg_socket_pair[1] = safe_close(kmsg_socket_pair[1]);
+        rtnl_socket_pair[1] = safe_close(rtnl_socket_pair[1]);
+        pid_socket_pair[1] = safe_close(pid_socket_pair[1]);
+        uuid_socket_pair[1] = safe_close(uuid_socket_pair[1]);
+        notify_socket_pair[1] = safe_close(notify_socket_pair[1]);
+        uid_shift_socket_pair[1] = safe_close(uid_shift_socket_pair[1]);
+
+        if (arg_userns_mode != USER_NAMESPACE_NO) {
+                /* The child just let us know the UID shift it might have read from the image. */
+                l = recv(uid_shift_socket_pair[0], &arg_uid_shift, sizeof arg_uid_shift, 0);
+                if (l < 0)
+                        return log_error_errno(errno, "Failed to read UID shift: %m");
+
+                if (l != sizeof arg_uid_shift) {
+                        log_error("Short read while reading UID shift.");
+                        return -EIO;
+                }
+
+                if (arg_userns_mode == USER_NAMESPACE_PICK) {
+                        /* If we are supposed to pick the UID shift, let's try to use the shift read from the
+                         * image, but if that's already in use, pick a new one, and report back to the child,
+                         * which one we now picked. */
+
+                        r = uid_shift_pick(&arg_uid_shift, &uid_shift_lock);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to pick suitable UID/GID range: %m");
+
+                        l = send(uid_shift_socket_pair[0], &arg_uid_shift, sizeof arg_uid_shift, MSG_NOSIGNAL);
+                        if (l < 0)
+                                return log_error_errno(errno, "Failed to send UID shift: %m");
+                        if (l != sizeof arg_uid_shift) {
+                                log_error("Short write while writing UID shift.");
+                                return -EIO;
+                        }
+                }
+        }
+
+        /* Wait for the outer child. */
+        r = wait_for_terminate_and_warn("namespace helper", *pid, NULL);
+        if (r != 0)
+                return r < 0 ? r : -EIO;
+
+        /* And now retrieve the PID of the inner child. */
+        l = recv(pid_socket_pair[0], pid, sizeof *pid, 0);
+        if (l < 0)
+                return log_error_errno(errno, "Failed to read inner child PID: %m");
+        if (l != sizeof *pid) {
+                log_error("Short read while reading inner child PID.");
+                return -EIO;
+        }
+
+        /* We also retrieve container UUID in case it was generated by outer child */
+        l = recv(uuid_socket_pair[0], &arg_uuid, sizeof arg_uuid, 0);
+        if (l < 0)
+                return log_error_errno(errno, "Failed to read container machine ID: %m");
+        if (l != sizeof(arg_uuid)) {
+                log_error("Short read while reading container machined ID.");
+                return -EIO;
+        }
+
+        /* We also retrieve the socket used for notifications generated by outer child */
+        notify_socket = receive_one_fd(notify_socket_pair[0], 0);
+        if (notify_socket < 0)
+                return log_error_errno(notify_socket,
+                                       "Failed to receive notification socket from the outer child: %m");
+
+        log_debug("Init process invoked as PID "PID_FMT, *pid);
+
+        if (arg_userns_mode != USER_NAMESPACE_NO) {
+                if (!barrier_place_and_sync(&barrier)) { /* #1 */
+                        log_error("Child died too early.");
+                        return -ESRCH;
+                }
+
+                r = setup_uid_map(*pid);
+                if (r < 0)
+                        return r;
+
+                (void) barrier_place(&barrier); /* #2 */
+        }
+
+        if (arg_private_network) {
+
+                r = move_network_interfaces(*pid, arg_network_interfaces);
+                if (r < 0)
+                        return r;
+
+                if (arg_network_veth) {
+                        r = setup_veth(arg_machine, *pid, veth_name,
+                                       arg_network_bridge || arg_network_zone);
+                        if (r < 0)
+                                return r;
+                        else if (r > 0)
+                                ifi = r;
+
+                        if (arg_network_bridge) {
+                                /* Add the interface to a bridge */
+                                r = setup_bridge(veth_name, arg_network_bridge, false);
+                                if (r < 0)
+                                        return r;
+                                if (r > 0)
+                                        ifi = r;
+                        } else if (arg_network_zone) {
+                                /* Add the interface to a bridge, possibly creating it */
+                                r = setup_bridge(veth_name, arg_network_zone, true);
+                                if (r < 0)
+                                        return r;
+                                if (r > 0)
+                                        ifi = r;
+                        }
+                }
+
+                r = setup_veth_extra(arg_machine, *pid, arg_network_veth_extra);
+                if (r < 0)
+                        return r;
+
+                /* We created the primary and extra veth links now; let's remember this, so that we know to
+                   remove them later on. Note that we don't bother with removing veth links that were created
+                   here when their setup failed half-way, because in that case the kernel should be able to
+                   remove them on its own, since they cannot be referenced by anything yet. */
+                *veth_created = true;
+
+                r = setup_macvlan(arg_machine, *pid, arg_network_macvlan);
+                if (r < 0)
+                        return r;
+
+                r = setup_ipvlan(arg_machine, *pid, arg_network_ipvlan);
+                if (r < 0)
+                        return r;
+        }
+
+        if (arg_register) {
+                r = register_machine(
+                                arg_machine,
+                                *pid,
+                                arg_directory,
+                                arg_uuid,
+                                ifi,
+                                arg_slice,
+                                arg_custom_mounts, arg_n_custom_mounts,
+                                arg_kill_signal,
+                                arg_property,
+                                arg_keep_unit,
+                                arg_container_service_name);
+                if (r < 0)
+                        return r;
+        }
+
+        r = sync_cgroup(*pid, arg_unified_cgroup_hierarchy, arg_uid_shift);
+        if (r < 0)
+                return r;
+
+        if (arg_keep_unit) {
+                r = create_subcgroup(*pid, arg_unified_cgroup_hierarchy);
+                if (r < 0)
+                        return r;
+        }
+
+        r = chown_cgroup(*pid, arg_uid_shift);
+        if (r < 0)
+                return r;
+
+        /* Notify the child that the parent is ready with all
+         * its setup (including cgroup-ification), and that
+         * the child can now hand over control to the code to
+         * run inside the container. */
+        (void) barrier_place(&barrier); /* #3 */
+
+        /* Block SIGCHLD here, before notifying child.
+         * process_pty() will handle it with the other signals. */
+        assert_se(sigprocmask(SIG_BLOCK, &mask_chld, NULL) >= 0);
+
+        /* Reset signal to default */
+        r = default_signals(SIGCHLD, -1);
+        if (r < 0)
+                return log_error_errno(r, "Failed to reset SIGCHLD: %m");
+
+        r = sd_event_new(&event);
+        if (r < 0)
+                return log_error_errno(r, "Failed to get default event source: %m");
+
+        r = setup_sd_notify_parent(event, notify_socket, PID_TO_PTR(*pid));
+        if (r < 0)
+                return r;
+
+        /* Let the child know that we are ready and wait that the child is completely ready now. */
+        if (!barrier_place_and_sync(&barrier)) { /* #4 */
+                log_error("Child died too early.");
+                return -ESRCH;
+        }
+
+        /* At this point we have made use of the UID we picked, and thus nss-mymachines
+         * will make them appear in getpwuid(), thus we can release the /etc/passwd lock. */
+        etc_passwd_lock = safe_close(etc_passwd_lock);
+
+        sd_notifyf(false,
+                   "STATUS=Container running.\n"
+                   "X_NSPAWN_LEADER_PID=" PID_FMT, *pid);
+        if (!arg_notify_ready)
+                sd_notify(false, "READY=1\n");
+
+        if (arg_kill_signal > 0) {
+                /* Try to kill the init system on SIGINT or SIGTERM */
+                sd_event_add_signal(event, NULL, SIGINT, on_orderly_shutdown, PID_TO_PTR(*pid));
+                sd_event_add_signal(event, NULL, SIGTERM, on_orderly_shutdown, PID_TO_PTR(*pid));
+        } else {
+                /* Immediately exit */
+                sd_event_add_signal(event, NULL, SIGINT, NULL, NULL);
+                sd_event_add_signal(event, NULL, SIGTERM, NULL, NULL);
+        }
+
+        /* simply exit on sigchld */
+        sd_event_add_signal(event, NULL, SIGCHLD, NULL, NULL);
+
+        if (arg_expose_ports) {
+                r = expose_port_watch_rtnl(event, rtnl_socket_pair[0], on_address_change, exposed, &rtnl);
+                if (r < 0)
+                        return r;
+
+                (void) expose_port_execute(rtnl, arg_expose_ports, exposed);
+        }
+
+        rtnl_socket_pair[0] = safe_close(rtnl_socket_pair[0]);
+
+        r = pty_forward_new(event, master,
+                            PTY_FORWARD_IGNORE_VHANGUP | (interactive ? 0 : PTY_FORWARD_READ_ONLY),
+                            &forward);
+        if (r < 0)
+                return log_error_errno(r, "Failed to create PTY forwarder: %m");
+
+        r = sd_event_loop(event);
+        if (r < 0)
+                return log_error_errno(r, "Failed to run event loop: %m");
+
+        pty_forward_get_last_char(forward, &last_char);
+
+        forward = pty_forward_free(forward);
+
+        if (!arg_quiet && last_char != '\n')
+                putc('\n', stdout);
+
+        /* Kill if it is not dead yet anyway */
+        if (arg_register && !arg_keep_unit)
+                terminate_machine(*pid);
+
+        /* Normally redundant, but better safe than sorry */
+        kill(*pid, SIGKILL);
+
+        r = wait_for_container(*pid, &container_status);
+        *pid = 0;
+
+        if (r < 0)
+                /* We failed to wait for the container, or the container exited abnormally. */
+                return r;
+        if (r > 0 || container_status == CONTAINER_TERMINATED) {
+                /* r > 0 → The container exited with a non-zero status.
+                 *         As a special case, we need to replace 133 with a different value,
+                 *         because 133 is special-cased in the service file to reboot the container.
+                 * otherwise → The container exited with zero status and a reboot was not requested.
+                 */
+                if (r == 133)
+                        r = EXIT_FAILURE; /* replace 133 with the general failure code */
+                *ret = r;
+                return 0; /* finito */
+        }
+
+        /* CONTAINER_REBOOTED, loop again */
+
+        if (arg_keep_unit) {
+                /* Special handling if we are running as a service: instead of simply
+                 * restarting the machine we want to restart the entire service, so let's
+                 * inform systemd about this with the special exit code 133. The service
+                 * file uses RestartForceExitStatus=133 so that this results in a full
+                 * nspawn restart. This is necessary since we might have cgroup parameters
+                 * set we want to have flushed out. */
+                *ret = 0;
+                return 133;
+        }
+
+        expose_port_flush(arg_expose_ports, exposed);
+
+        (void) remove_veth_links(veth_name, arg_network_veth_extra);
+        *veth_created = false;
+        return 1; /* loop again */
+}
+
+int main(int argc, char *argv[]) {
+
+        _cleanup_free_ char *device_path = NULL, *root_device = NULL, *home_device = NULL, *srv_device = NULL, *esp_device = NULL, *console = NULL;
+        bool root_device_rw = true, home_device_rw = true, srv_device_rw = true;
+        _cleanup_close_ int master = -1, image_fd = -1;
+        _cleanup_fdset_free_ FDSet *fds = NULL;
+        int r, n_fd_passed, loop_nr = -1, ret = EXIT_SUCCESS;
+        char veth_name[IFNAMSIZ] = "";
+        bool secondary = false, remove_subvol = false;
+        pid_t pid = 0;
+        union in_addr_union exposed = {};
+        _cleanup_release_lock_file_ LockFile tree_global_lock = LOCK_FILE_INIT, tree_local_lock = LOCK_FILE_INIT;
+        bool interactive, veth_created = false;
+
+        log_parse_environment();
+        log_open();
+
+        /* Make sure rename_process() in the stub init process can work */
+        saved_argv = argv;
+        saved_argc = argc;
+
+        r = parse_argv(argc, argv);
+        if (r <= 0)
+                goto finish;
+
+        if (geteuid() != 0) {
+                log_error("Need to be root.");
+                r = -EPERM;
+                goto finish;
+        }
+        r = determine_names();
+        if (r < 0)
+                goto finish;
+
+        r = load_settings();
+        if (r < 0)
+                goto finish;
+
+        r = verify_arguments();
+        if (r < 0)
+                goto finish;
+
+        n_fd_passed = sd_listen_fds(false);
+        if (n_fd_passed > 0) {
+                r = fdset_new_listen_fds(&fds, false);
+                if (r < 0) {
+                        log_error_errno(r, "Failed to collect file descriptors: %m");
+                        goto finish;
+                }
+        }
+
+        if (arg_directory) {
+                assert(!arg_image);
+
+                if (path_equal(arg_directory, "/") && !arg_ephemeral) {
+                        log_error("Spawning container on root directory is not supported. Consider using --ephemeral.");
+                        r = -EINVAL;
+                        goto finish;
+                }
+
+                if (arg_ephemeral) {
+                        _cleanup_free_ char *np = NULL;
+
+                        /* If the specified path is a mount point we
+                         * generate the new snapshot immediately
+                         * inside it under a random name. However if
+                         * the specified is not a mount point we
+                         * create the new snapshot in the parent
+                         * directory, just next to it. */
+                        r = path_is_mount_point(arg_directory, 0);
+                        if (r < 0) {
+                                log_error_errno(r, "Failed to determine whether directory %s is mount point: %m", arg_directory);
+                                goto finish;
+                        }
+                        if (r > 0)
+                                r = tempfn_random_child(arg_directory, "machine.", &np);
+                        else
+                                r = tempfn_random(arg_directory, "machine.", &np);
+                        if (r < 0) {
+                                log_error_errno(r, "Failed to generate name for snapshot: %m");
+                                goto finish;
+                        }
+
+                        r = image_path_lock(np, (arg_read_only ? LOCK_SH : LOCK_EX) | LOCK_NB, &tree_global_lock, &tree_local_lock);
+                        if (r < 0) {
+                                log_error_errno(r, "Failed to lock %s: %m", np);
+                                goto finish;
+                        }
+
+                        r = btrfs_subvol_snapshot(arg_directory, np, (arg_read_only ? BTRFS_SNAPSHOT_READ_ONLY : 0) | BTRFS_SNAPSHOT_FALLBACK_COPY | BTRFS_SNAPSHOT_RECURSIVE | BTRFS_SNAPSHOT_QUOTA);
+                        if (r < 0) {
+                                log_error_errno(r, "Failed to create snapshot %s from %s: %m", np, arg_directory);
+                                goto finish;
+                        }
+
+                        free(arg_directory);
+                        arg_directory = np;
+                        np = NULL;
+
+                        remove_subvol = true;
+
+                } else {
+                        r = image_path_lock(arg_directory, (arg_read_only ? LOCK_SH : LOCK_EX) | LOCK_NB, &tree_global_lock, &tree_local_lock);
+                        if (r == -EBUSY) {
+                                log_error_errno(r, "Directory tree %s is currently busy.", arg_directory);
+                                goto finish;
+                        }
+                        if (r < 0) {
+                                log_error_errno(r, "Failed to lock %s: %m", arg_directory);
+                                goto finish;
+                        }
+
+                        if (arg_template) {
+                                r = btrfs_subvol_snapshot(arg_template, arg_directory, (arg_read_only ? BTRFS_SNAPSHOT_READ_ONLY : 0) | BTRFS_SNAPSHOT_FALLBACK_COPY | BTRFS_SNAPSHOT_RECURSIVE | BTRFS_SNAPSHOT_QUOTA);
+                                if (r == -EEXIST) {
+                                        if (!arg_quiet)
+                                                log_info("Directory %s already exists, not populating from template %s.", arg_directory, arg_template);
+                                } else if (r < 0) {
+                                        log_error_errno(r, "Couldn't create snapshot %s from %s: %m", arg_directory, arg_template);
+                                        goto finish;
+                                } else {
+                                        if (!arg_quiet)
+                                                log_info("Populated %s from template %s.", arg_directory, arg_template);
+                                }
+                        }
+                }
+
+                if (arg_start_mode == START_BOOT) {
+                        if (path_is_os_tree(arg_directory) <= 0) {
+                                log_error("Directory %s doesn't look like an OS root directory (os-release file is missing). Refusing.", arg_directory);
+                                r = -EINVAL;
+                                goto finish;
+                        }
+                } else {
+                        const char *p;
+
+                        p = strjoina(arg_directory, "/usr/");
+                        if (laccess(p, F_OK) < 0) {
+                                log_error("Directory %s doesn't look like it has an OS tree. Refusing.", arg_directory);
+                                r = -EINVAL;
+                                goto finish;
+                        }
+                }
+
+        } else {
+                char template[] = "/tmp/nspawn-root-XXXXXX";
+
+                assert(arg_image);
+                assert(!arg_template);
+
+                r = image_path_lock(arg_image, (arg_read_only ? LOCK_SH : LOCK_EX) | LOCK_NB, &tree_global_lock, &tree_local_lock);
+                if (r == -EBUSY) {
+                        r = log_error_errno(r, "Disk image %s is currently busy.", arg_image);
+                        goto finish;
+                }
+                if (r < 0) {
+                        r = log_error_errno(r, "Failed to create image lock: %m");
+                        goto finish;
+                }
+
+                if (!mkdtemp(template)) {
+                        log_error_errno(errno, "Failed to create temporary directory: %m");
+                        r = -errno;
+                        goto finish;
+                }
+
+                arg_directory = strdup(template);
+                if (!arg_directory) {
+                        r = log_oom();
+                        goto finish;
+                }
+
+                image_fd = setup_image(&device_path, &loop_nr);
+                if (image_fd < 0) {
+                        r = image_fd;
+                        goto finish;
+                }
+
+                r = dissect_image(image_fd,
+                                  &root_device, &root_device_rw,
+                                  &home_device, &home_device_rw,
+                                  &srv_device, &srv_device_rw,
+                                  &esp_device,
+                                  &secondary);
+                if (r < 0)
+                        goto finish;
+        }
+
+        r = custom_mounts_prepare();
+        if (r < 0)
+                goto finish;
+
+        interactive =
+                isatty(STDIN_FILENO) > 0 &&
+                isatty(STDOUT_FILENO) > 0;
+
+        master = posix_openpt(O_RDWR|O_NOCTTY|O_CLOEXEC|O_NDELAY);
+        if (master < 0) {
+                r = log_error_errno(errno, "Failed to acquire pseudo tty: %m");
+                goto finish;
+        }
+
+        r = ptsname_malloc(master, &console);
+        if (r < 0) {
+                r = log_error_errno(r, "Failed to determine tty name: %m");
+                goto finish;
+        }
+
+        if (arg_selinux_apifs_context) {
+                r = mac_selinux_apply(console, arg_selinux_apifs_context);
+                if (r < 0)
+                        goto finish;
+        }
+
+        if (unlockpt(master) < 0) {
+                r = log_error_errno(errno, "Failed to unlock tty: %m");
+                goto finish;
+        }
+
+        if (!arg_quiet)
+                log_info("Spawning container %s on %s.\nPress ^] three times within 1s to kill container.",
+                         arg_machine, arg_image ?: arg_directory);
+
+        assert_se(sigprocmask_many(SIG_BLOCK, NULL, SIGCHLD, SIGWINCH, SIGTERM, SIGINT, -1) >= 0);
+
+        if (prctl(PR_SET_CHILD_SUBREAPER, 1) < 0) {
+                r = log_error_errno(errno, "Failed to become subreaper: %m");
+                goto finish;
+        }
+
+        for (;;) {
+                r = run(master,
+                        console,
+                        root_device, root_device_rw,
+                        home_device, home_device_rw,
+                        srv_device, srv_device_rw,
+                        esp_device,
+                        interactive, secondary,
+                        fds,
+                        veth_name, &veth_created,
+                        &exposed,
+                        &pid, &ret);
+                if (r <= 0)
+                        break;
+        }
+
+finish:
+        sd_notify(false,
+                  "STOPPING=1\n"
+                  "STATUS=Terminating...");
+
+        if (pid > 0)
+                kill(pid, SIGKILL);
+
+        /* Try to flush whatever is still queued in the pty */
+        if (master >= 0)
+                (void) copy_bytes(master, STDOUT_FILENO, (uint64_t) -1, false);
+
+        loop_remove(loop_nr, &image_fd);
+
+        if (remove_subvol && arg_directory) {
+                int k;
+
+                k = btrfs_subvol_remove(arg_directory, BTRFS_REMOVE_RECURSIVE|BTRFS_REMOVE_QUOTA);
+                if (k < 0)
+                        log_warning_errno(k, "Cannot remove subvolume '%s', ignoring: %m", arg_directory);
+        }
+
+        if (arg_machine) {
+                const char *p;
+
+                p = strjoina("/run/systemd/nspawn/propagate/", arg_machine);
+                (void) rm_rf(p, REMOVE_ROOT);
+        }
+
+        expose_port_flush(arg_expose_ports, &exposed);
+
+        if (veth_created)
+                (void) remove_veth_links(veth_name, arg_network_veth_extra);
+        (void) remove_bridge(arg_network_zone);
+
+        free(arg_directory);
+        free(arg_template);
+        free(arg_image);
+        free(arg_machine);
+        free(arg_user);
+        free(arg_chdir);
+        strv_free(arg_setenv);
+        free(arg_network_bridge);
+        strv_free(arg_network_interfaces);
+        strv_free(arg_network_macvlan);
+        strv_free(arg_network_ipvlan);
+        strv_free(arg_network_veth_extra);
+        strv_free(arg_parameters);
+        custom_mount_free_all(arg_custom_mounts, arg_n_custom_mounts);
+        expose_port_free_all(arg_expose_ports);
+
+        return r < 0 ? EXIT_FAILURE : ret;
+}
diff --git a/src/systemd-nspawn/systemd-nspawn.completion.bash b/src/systemd-nspawn/systemd-nspawn.completion.bash
new file mode 100644
index 0000000000..ea4a5e1f43
--- /dev/null
+++ b/src/systemd-nspawn/systemd-nspawn.completion.bash
@@ -0,0 +1,155 @@
+# systemd-nspawn(1) completion                  -*- shell-script -*-
+#
+# This file is part of systemd.
+#
+# Copyright 2014 Thomas H.P. Andersen
+#
+# systemd is free software; you can redistribute it and/or modify it
+# under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation; either version 2.1 of the License, or
+# (at your option) any later version.
+#
+# systemd is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+# General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with systemd; If not, see <http://www.gnu.org/licenses/>.
+
+__contains_word() {
+        local w word=$1; shift
+        for w in "$@"; do
+                [[ $w = "$word" ]] && return
+        done
+}
+
+__get_users() {
+        local a b
+        loginctl list-users --no-legend --no-pager | { while read a b; do echo " $b"; done; };
+}
+
+__get_slices() {
+        local a b
+        systemctl list-units -t slice --no-legend --no-pager | { while read a b; do echo " $a"; done; };
+}
+
+__get_machines() {
+        local a b
+        machinectl list --no-legend --no-pager | { while read a b; do echo " $a"; done; };
+}
+
+__get_env() {
+        local a
+        env | { while read a; do echo " ${a%%=*}"; done; };
+}
+
+__get_interfaces(){
+        { cd /sys/class/net && echo *; } | \
+        while read -d' ' -r name; do
+                [[ "$name" != "lo" ]] && echo "$name"
+        done
+}
+
+_systemd_nspawn() {
+        local cur=${COMP_WORDS[COMP_CWORD]} prev=${COMP_WORDS[COMP_CWORD-1]}
+        local i verb comps
+
+        local -A OPTS=(
+               [STANDALONE]='-h --help --version --private-network -b --boot --read-only -q --quiet --share-system --keep-unit --network-veth -j'
+                      [ARG]='-D --directory -u --user --uuid --capability --drop-capability --link-journal --bind --bind-ro -M --machine
+                             -S --slice --setenv -Z --selinux-context -L --selinux-apifs-context --register --network-interface --network-bridge
+                             --personality -i --image --tmpfs --volatile
+                             --network-macvlan --kill-signal --template
+                             --notify-ready'
+        )
+
+        _init_completion || return
+
+        if __contains_word "$prev" ${OPTS[ARG]}; then
+                case $prev in
+                        --directory|-D|--template)
+                                compopt -o nospace
+                                comps=$(compgen -S/ -A directory -- "$cur" )
+                        ;;
+                        --user|-u)
+                                comps=$( __get_users )
+                        ;;
+                        --uuid)
+                                comps=''
+                        ;;
+                        --capability)
+                                comps='CAP_BLOCK_SUSPEND CAP_IPC_LOCK CAP_MAC_ADMIN CAP_MAC_OVERRIDE CAP_SYS_MODULE CAP_SYS_PACCT CAP_SYS_RAWIO
+                                       CAP_SYS_TIME CAP_SYSLOG CAP_WAKE_ALARM CAP_NET_ADMIN'
+                        ;;
+                        --drop-capability)
+                                comps='CAP_AUDIT_CONTROL CAP_AUDIT_WRITE CAP_CHOWN CAP_DAC_OVERRIDE CAP_DAC_READ_SEARCH CAP_FOWNER CAP_FSETID
+                                       CAP_IPC_OWNER CAP_KILL CAP_LEASE CAP_LINUX_IMMUTABLE CAP_MKNOD CAP_NET_ADMIN CAP_NET_BIND_SERVICE
+                                       CAP_NET_BROADCAST CAP_NET_RAW CAP_SETFCAP CAP_SETGID CAP_SETPCAP CAP_SETUID CAP_SYS_ADMIN CAP_SYS_BOOT
+                                       CAP_SYS_CHROOT CAP_SYS_NICE CAP_SYS_PTRACE CAP_SYS_RESOURCE CAP_SYS_TTY_CONFIG'
+                        ;;
+                        --link-journal)
+                                comps='no auto guest try-guest host try-host'
+                        ;;
+                        --bind|--bind-ro)
+                                compopt -o nospace
+                                comps=$(compgen -S/ -A directory -- "$cur" )
+                        ;;
+                        --tmpfs)
+                                compopt -o nospace
+                                comps=$(compgen -S/ -A directory -- "$cur" )
+                        ;;
+                        --machine|-M)
+                                comps=$( __get_machines )
+                        ;;
+                        --slice|-S)
+                                comps=$( __get_slices )
+                        ;;
+                        --setenv)
+                                comps=$( __get_env )
+                        ;;
+                        --selinux-context|-Z)
+                                comps=''
+                        ;;
+                        --selinux-apifs-context|-L)
+                                comps=''
+                        ;;
+                        --register)
+                                comps='yes no'
+                        ;;
+                        --network-interface)
+                                comps=$(__get_interfaces)
+                        ;;
+                        --network-bridge)
+                                comps=''
+                        ;;
+                        --network-macvlan)
+                                comps=''
+                        ;;
+                        --personality)
+                                comps='x86 x86-64'
+                        ;;
+                        --volatile)
+                                comps='yes state no'
+                        ;;
+                        --image|-i)
+                                compopt -o nospace
+                                comps=$( compgen -A file -- "$cur" )
+                        ;;
+                        --kill-signal)
+                                _signals
+                                return
+                        ;;
+                        --notify-ready)
+                                comps='yes no'
+                                return
+                        ;;
+                esac
+                COMPREPLY=( $(compgen -W '$comps' -- "$cur") )
+                return 0
+        fi
+
+        COMPREPLY=( $(compgen -W '${OPTS[*]}' -- "$cur") )
+}
+
+complete -F _systemd_nspawn systemd-nspawn
diff --git a/src/systemd-nspawn/systemd-nspawn.completion.zsh b/src/systemd-nspawn/systemd-nspawn.completion.zsh
new file mode 100644
index 0000000000..77b2e7cd7c
--- /dev/null
+++ b/src/systemd-nspawn/systemd-nspawn.completion.zsh
@@ -0,0 +1,50 @@
+#compdef systemd-nspawn
+
+_nspawn-caps(){
+    local -a _caps
+    _caps=( CAP_CHOWN CAP_DAC_OVERRIDE CAP_DAC_READ_SEARCH
+            CAP_FOWNER CAP_FSETID CAP_IPC_OWNER CAP_KILL CAP_LEASE CAP_LINUX_IMMUTABLE
+            CAP_NET_BIND_SERVICE CAP_NET_BROADCAST CAP_NET_RAW CAP_SETGID CAP_SETFCAP CAP_SETPCAP
+            CAP_SETUID CAP_SYS_ADMIN CAP_SYS_CHROOT CAP_SYS_NICE CAP_SYS_PTRACE CAP_SYS_TTY_CONFIG
+            CAP_SYS_RESOURCE CAP_SYS_BOOT )
+    _values -s , 'capabilities' "$_caps[@]"
+}
+
+_arguments \
+    {-h,--help}'[Show this help.]' \
+    '--version[Print a short version string and exit.]' \
+    {--quiet,-q}'[Turns off any status output by the tool itself.]' \
+    {--directory=,-D+}'[Directory to use as file system root for the namespace container. If omitted the current directory will be used.]:directories:_directories' \
+    '--template=[Initialize root directory from template directory, if missing.]:template:_directories' \
+    {--ephemeral,-x}'[Run container with snapshot of root directory, and remove it after exit.]' \
+    {--image=,-i+}'[Disk image to mount the root directory for the container from.]:disk image: _files' \
+    {--boot,-b}'[Automatically search for an init binary and invoke it instead of a shell or a user supplied program.]' \
+    {--user=,-u+}'[Run the command under specified user, create home directory and cd into it.]:user:_users' \
+    {--machine=,-M+}'[Sets the machine name for this container.]: : _message "container name"' \
+    '--uuid=[Set the specified uuid for the container.]: : _message "container UUID"' \
+    {--slice=,-S+}'[Make the container part of the specified slice, instead of the default machine.slice.]: : _message slice' \
+    '--private-network[Disconnect networking of the container from the host.]' \
+    '--network-interface=[Assign the specified network interface to the container.]: : _net_interfaces' \
+    '--network-macvlan=[Create a "macvlan" interface of the specified Ethernet network interface and add it to the container.]: : _net_interfaces' \
+    '--network-ipvlan=[Create a ipvlan network interface based on an existing network interface to the container.]: : _net_interfaces' \
+    {--network-veth,-n}'[Create a virtual Ethernet link (veth) between host and container.]' \
+    '--network-bridge=[Adds the host side of the Ethernet link created with --network-veth to the specified bridge.]: : _net_interfaces' \
+    {--port=,-p+}'[Expose a container IP port on the host.]: : _message port' \
+    {--selinux-context=,-Z+}'[Sets the SELinux security context to be used to label processes in the container.]: : _message "SELinux context"' \
+    {--selinux-apifs-context=,-L+}'[Sets the SELinux security context to be used to label files in the virtual API file systems in the container.]: : _message "SELinux context"' \
+    '--capability=[List one or more additional capabilities to grant the container.]:capabilities:_nspawn-caps' \
+    '--drop-capability=[Specify one or more additional capabilities to drop for the containerm]:capabilities:_nspawn-caps' \
+    "--link-journal=[Control whether the container's journal shall be made visible to the host system.]:options:(no host guest auto)" \
+    '-j[Equivalent to --link-journal=guest.]' \
+    '--read-only[Mount the root file system read only for the container.]' \
+    '--bind=[Bind mount a file or directory from the host into the container.]: : _files' \
+    '--bind-ro=[Bind mount a file or directory from the host into the container (read-only).]: : _files' \
+    '--tmpfs=[Mount an empty tmpfs to the specified directory.]: : _files' \
+    '--setenv=[Specifies an environment variable assignment to pass to the init process in the container, in the format "NAME=VALUE".]: : _message "environment variables"' \
+    '--share-system[Allows the container to share certain system facilities with the host.]' \
+    '--register=[Controls whether the container is registered with systemd-machined(8).]:systemd-machined registration:( yes no )' \
+    '--keep-unit[Instead of creating a transient scope unit to run the container in, simply register the service or scope unit systemd-nspawn has been invoked in with systemd-machined(8).]' \
+    '--personality=[Control the architecture ("personality") reported by uname(2) in the container.]:architecture:(x86 x86-64)' \
+    '--volatile=[Run the system in volatile mode.]:volatile:(no yes state)' \
+    "--notify-ready=[Control when the ready notification is sent]:options:(yes no)" \
+    '*:: : _normal'
diff --git a/src/systemd-nspawn/systemd-nspawn.tmpfiles b/src/systemd-nspawn/systemd-nspawn.tmpfiles
new file mode 100644
index 0000000000..78bd1c670e
--- /dev/null
+++ b/src/systemd-nspawn/systemd-nspawn.tmpfiles
@@ -0,0 +1,23 @@
+#  This file is part of systemd.
+#
+#  systemd is free software; you can redistribute it and/or modify it
+#  under the terms of the GNU Lesser General Public License as published by
+#  the Free Software Foundation; either version 2.1 of the License, or
+#  (at your option) any later version.
+
+# See tmpfiles.d(5) for details
+
+Q /var/lib/machines 0700 - - -
+
+# Remove old temporary snapshots, but only at boot. Ideally we'd have
+# "self-destroying" btrfs snapshots that go away if the last
+# reference to it does. To mimic a scheme like this at least remove
+# the old snapshots on fresh boots, where we know they cannot be
+# referenced anymore. Note that we actually remove all temporary files
+# in /var/lib/machines/ at boot, which should be safe since the
+# directory has defined semantics. In the root directory (where
+# systemd-nspawn --ephemeral places snapshots) we are more strict, to
+# avoid removing unrelated temporary files.
+
+R! /var/lib/machines/.#*
+R! /.#machine.*
diff --git a/src/systemd-nspawn/systemd-nspawn.xml b/src/systemd-nspawn/systemd-nspawn.xml
new file mode 100644
index 0000000000..c449edee89
--- /dev/null
+++ b/src/systemd-nspawn/systemd-nspawn.xml
@@ -0,0 +1,1088 @@
+<?xml version='1.0'?> <!--*- Mode: nxml; nxml-child-indent: 2; indent-tabs-mode: nil -*-->
+<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
+  "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
+
+<!--
+  This file is part of systemd.
+
+  Copyright 2010 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+-->
+
+<refentry id="systemd-nspawn"
+    xmlns:xi="http://www.w3.org/2001/XInclude">
+
+  <refentryinfo>
+    <title>systemd-nspawn</title>
+    <productname>systemd</productname>
+
+    <authorgroup>
+      <author>
+        <contrib>Developer</contrib>
+        <firstname>Lennart</firstname>
+        <surname>Poettering</surname>
+        <email>lennart@poettering.net</email>
+      </author>
+    </authorgroup>
+  </refentryinfo>
+
+  <refmeta>
+    <refentrytitle>systemd-nspawn</refentrytitle>
+    <manvolnum>1</manvolnum>
+  </refmeta>
+
+  <refnamediv>
+    <refname>systemd-nspawn</refname>
+    <refpurpose>Spawn a namespace container for debugging, testing and building</refpurpose>
+  </refnamediv>
+
+  <refsynopsisdiv>
+    <cmdsynopsis>
+      <command>systemd-nspawn</command>
+      <arg choice="opt" rep="repeat">OPTIONS</arg>
+      <arg choice="opt"><replaceable>COMMAND</replaceable>
+      <arg choice="opt" rep="repeat">ARGS</arg>
+      </arg>
+    </cmdsynopsis>
+    <cmdsynopsis>
+      <command>systemd-nspawn</command>
+      <arg choice="plain">--boot</arg>
+      <arg choice="opt" rep="repeat">OPTIONS</arg>
+      <arg choice="opt" rep="repeat">ARGS</arg>
+    </cmdsynopsis>
+  </refsynopsisdiv>
+
+  <refsect1>
+    <title>Description</title>
+
+    <para><command>systemd-nspawn</command> may be used to run a command or OS in a light-weight namespace
+    container. In many ways it is similar to <citerefentry
+    project='man-pages'><refentrytitle>chroot</refentrytitle><manvolnum>1</manvolnum></citerefentry>, but more powerful
+    since it fully virtualizes the file system hierarchy, as well as the process tree, the various IPC subsystems and
+    the host and domain name.</para>
+
+    <para><command>systemd-nspawn</command> may be invoked on any directory tree containing an operating system tree,
+    using the <option>--directory=</option> command line option. By using the <option>--machine=</option> option an OS
+    tree is automatically searched for in a couple of locations, most importantly in
+    <filename>/var/lib/machines</filename>, the suggested directory to place container images installed on the
+    system.</para>
+
+    <para>In contrast to <citerefentry
+    project='man-pages'><refentrytitle>chroot</refentrytitle><manvolnum>1</manvolnum></citerefentry> <command>systemd-nspawn</command>
+    may be used to boot full Linux-based operating systems in a container.</para>
+
+    <para><command>systemd-nspawn</command> limits access to various kernel interfaces in the container to read-only,
+    such as <filename>/sys</filename>, <filename>/proc/sys</filename> or <filename>/sys/fs/selinux</filename>. The
+    host's network interfaces and the system clock may not be changed from within the container. Device nodes may not
+    be created. The host system cannot be rebooted and kernel modules may not be loaded from within the
+    container.</para>
+
+    <para>Use a tool like <citerefentry
+    project='mankier'><refentrytitle>dnf</refentrytitle><manvolnum>8</manvolnum></citerefentry>, <citerefentry
+    project='die-net'><refentrytitle>debootstrap</refentrytitle><manvolnum>8</manvolnum></citerefentry>, or
+    <citerefentry project='archlinux'><refentrytitle>pacman</refentrytitle><manvolnum>8</manvolnum></citerefentry> to
+    set up an OS directory tree suitable as file system hierarchy for <command>systemd-nspawn</command> containers. See
+    the Examples section below for details on suitable invocation of these commands.</para>
+
+    <para>As a safety check <command>systemd-nspawn</command> will verify the existence of
+    <filename>/usr/lib/os-release</filename> or <filename>/etc/os-release</filename> in the container tree before
+    starting the container (see
+    <citerefentry><refentrytitle>os-release</refentrytitle><manvolnum>5</manvolnum></citerefentry>).  It might be
+    necessary to add this file to the container tree manually if the OS of the container is too old to contain this
+    file out-of-the-box.</para>
+
+    <para><command>systemd-nspawn</command> may be invoked directly from the interactive command line or run as system
+    service in the background. In this mode each container instance runs as its own service instance; a default
+    template unit file <filename>systemd-nspawn@.service</filename> is provided to make this easy, taking the container
+    name as instance identifier. Note that different default options apply when <command>systemd-nspawn</command> is
+    invoked by the template unit file than interactively on the command line. Most importantly the template unit file
+    makes use of the <option>--boot</option> which is not the default in case <command>systemd-nspawn</command> is
+    invoked from the interactive command line. Further differences with the defaults are documented along with the
+    various supported options below.</para>
+
+    <para>The <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry> tool may
+    be used to execute a number of operations on containers. In particular it provides easy-to-use commands to run
+    containers as system services using the <filename>systemd-nspawn@.service</filename> template unit
+    file.</para>
+
+    <para>Along with each container a settings file with the <filename>.nspawn</filename> suffix may exist, containing
+    additional settings to apply when running the container. See
+    <citerefentry><refentrytitle>systemd.nspawn</refentrytitle><manvolnum>5</manvolnum></citerefentry> for
+    details. Settings files override the default options used by the <filename>systemd-nspawn@.service</filename>
+    template unit file, making it usually unnecessary to alter this template file directly.</para>
+
+    <para>Note that <command>systemd-nspawn</command> will mount file systems private to the container to
+    <filename>/dev</filename>, <filename>/run</filename> and similar. These will not be visible outside of the
+    container, and their contents will be lost when the container exits.</para>
+
+    <para>Note that running two <command>systemd-nspawn</command> containers from the same directory tree will not make
+    processes in them see each other. The PID namespace separation of the two containers is complete and the containers
+    will share very few runtime objects except for the underlying file system. Use
+    <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry>'s
+    <command>login</command> or <command>shell</command> commands to request an additional login session in a running
+    container.</para>
+
+    <para><command>systemd-nspawn</command> implements the <ulink
+    url="http://www.freedesktop.org/wiki/Software/systemd/ContainerInterface">Container Interface</ulink>
+    specification.</para>
+
+    <para>While running, containers invoked with <command>systemd-nspawn</command> are registered with the
+    <citerefentry><refentrytitle>systemd-machined</refentrytitle><manvolnum>8</manvolnum></citerefentry> service that
+    keeps track of running containers, and provides programming interfaces to interact with them.</para>
+  </refsect1>
+
+  <refsect1>
+    <title>Options</title>
+
+    <para>If option <option>-b</option> is specified, the arguments
+    are used as arguments for the init binary. Otherwise,
+    <replaceable>COMMAND</replaceable> specifies the program to launch
+    in the container, and the remaining arguments are used as
+    arguments for this program. If <option>--boot</option> is not used and
+    no arguments are specified, a shell is launched in the
+    container.</para>
+
+    <para>The following options are understood:</para>
+
+    <variablelist>
+      <varlistentry>
+        <term><option>-D</option></term>
+        <term><option>--directory=</option></term>
+
+        <listitem><para>Directory to use as file system root for the
+        container.</para>
+
+        <para>If neither <option>--directory=</option>, nor
+        <option>--image=</option> is specified the directory is
+        determined by searching for a directory named the same as the
+        machine name specified with <option>--machine=</option>. See
+        <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+        section "Files and Directories" for the precise search path.</para>
+
+        <para>If neither <option>--directory=</option>,
+        <option>--image=</option>, nor <option>--machine=</option>
+        are specified, the current directory will
+        be used. May not be specified together with
+        <option>--image=</option>.</para></listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>--template=</option></term>
+
+        <listitem><para>Directory or <literal>btrfs</literal>
+        subvolume to use as template for the container's root
+        directory. If this is specified and the container's root
+        directory (as configured by <option>--directory=</option>)
+        does not yet exist it is created as <literal>btrfs</literal>
+        subvolume and populated from this template tree. Ideally, the
+        specified template path refers to the root of a
+        <literal>btrfs</literal> subvolume, in which case a simple
+        copy-on-write snapshot is taken, and populating the root
+        directory is instant. If the specified template path does not
+        refer to the root of a <literal>btrfs</literal> subvolume (or
+        not even to a <literal>btrfs</literal> file system at all),
+        the tree is copied, which can be substantially more
+        time-consuming. Note that if this option is used the
+        container's root directory (in contrast to the template
+        directory!) must be located on a <literal>btrfs</literal> file
+        system, so that the <literal>btrfs</literal> subvolume may be
+        created. May not be specified together with
+        <option>--image=</option> or
+        <option>--ephemeral</option>.</para>
+
+        <para>Note that this switch leaves host name, machine ID and
+        all other settings that could identify the instance
+        unmodified.</para></listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>-x</option></term>
+        <term><option>--ephemeral</option></term>
+
+        <listitem><para>If specified, the container is run with a
+        temporary <literal>btrfs</literal> snapshot of its root
+        directory (as configured with <option>--directory=</option>),
+        that is removed immediately when the container terminates.
+        This option is only supported if the root file system is
+        <literal>btrfs</literal>. May not be specified together with
+        <option>--image=</option> or
+        <option>--template=</option>.</para>
+        <para>Note that this switch leaves host name, machine ID and
+        all other settings that could identify the instance
+        unmodified.</para></listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>-i</option></term>
+        <term><option>--image=</option></term>
+
+        <listitem><para>Disk image to mount the root directory for the
+        container from. Takes a path to a regular file or to a block
+        device node. The file or block device must contain
+        either:</para>
+
+        <itemizedlist>
+          <listitem><para>An MBR partition table with a single
+          partition of type 0x83 that is marked
+          bootable.</para></listitem>
+
+          <listitem><para>A GUID partition table (GPT) with a single
+          partition of type
+          0fc63daf-8483-4772-8e79-3d69d8477de4.</para></listitem>
+
+          <listitem><para>A GUID partition table (GPT) with a marked
+          root partition which is mounted as the root directory of the
+          container. Optionally, GPT images may contain a home and/or
+          a server data partition which are mounted to the appropriate
+          places in the container. All these partitions must be
+          identified by the partition types defined by the <ulink
+          url="http://www.freedesktop.org/wiki/Specifications/DiscoverablePartitionsSpec/">Discoverable
+          Partitions Specification</ulink>.</para></listitem>
+        </itemizedlist>
+
+        <para>Any other partitions, such as foreign partitions, swap
+        partitions or EFI system partitions are not mounted. May not
+        be specified together with <option>--directory=</option>,
+        <option>--template=</option> or
+        <option>--ephemeral</option>.</para></listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>-a</option></term>
+        <term><option>--as-pid2</option></term>
+
+        <listitem><para>Invoke the shell or specified program as process ID (PID) 2 instead of PID 1 (init). By
+        default, if neither this option nor <option>--boot</option> is used, the selected binary is run as process with
+        PID 1, a mode only suitable for programs that are aware of the special semantics that the process with PID 1
+        has on UNIX. For example, it needs to reap all processes reparented to it, and should implement
+        <command>sysvinit</command> compatible signal handling (specifically: it needs to reboot on SIGINT, reexecute
+        on SIGTERM, reload configuration on SIGHUP, and so on). With <option>--as-pid2</option> a minimal stub init
+        process is run as PID 1 and the selected binary is executed as PID 2 (and hence does not need to implement any
+        special semantics). The stub init process will reap processes as necessary and react appropriately to
+        signals. It is recommended to use this mode to invoke arbitrary commands in containers, unless they have been
+        modified to run correctly as PID 1. Or in other words: this switch should be used for pretty much all commands,
+        except when the command refers to an init or shell implementation, as these are generally capable of running
+        correctly as PID 1. This option may not be combined with <option>--boot</option>.</para>
+        </listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>-b</option></term>
+        <term><option>--boot</option></term>
+
+        <listitem><para>Automatically search for an init binary and invoke it as PID 1, instead of a shell or a user
+        supplied program. If this option is used, arguments specified on the command line are used as arguments for the
+        init binary. This option may not be combined with <option>--as-pid2</option>.</para>
+
+        <para>The following table explains the different modes of invocation and relationship to
+        <option>--as-pid2</option> (see above):</para>
+
+        <table>
+          <title>Invocation Mode</title>
+          <tgroup cols='2' align='left' colsep='1' rowsep='1'>
+            <colspec colname="switch" />
+            <colspec colname="explanation" />
+            <thead>
+              <row>
+                <entry>Switch</entry>
+                <entry>Explanation</entry>
+              </row>
+            </thead>
+            <tbody>
+              <row>
+                <entry>Neither <option>--as-pid2</option> nor <option>--boot</option> specified</entry>
+                <entry>The passed parameters are interpreted as the command line, which is executed as PID 1 in the container.</entry>
+              </row>
+
+              <row>
+                <entry><option>--as-pid2</option> specified</entry>
+                <entry>The passed parameters are interpreted as the command line, which is executed as PID 2 in the container. A stub init process is run as PID 1.</entry>
+              </row>
+
+              <row>
+                <entry><option>--boot</option> specified</entry>
+                <entry>An init binary as automatically searched and run as PID 1 in the container. The passed parameters are used as invocation parameters for this process.</entry>
+              </row>
+
+            </tbody>
+          </tgroup>
+        </table>
+
+        <para>Note that <option>--boot</option> is the default mode of operation if the
+        <filename>systemd-nspawn@.service</filename> template unit file is used.</para>
+        </listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>--chdir=</option></term>
+
+        <listitem><para>Change to the specified working directory before invoking the process in the container. Expects
+        an absolute path in the container's file system namespace.</para></listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>-u</option></term>
+        <term><option>--user=</option></term>
+
+        <listitem><para>After transitioning into the container, change
+        to the specified user-defined in the container's user
+        database. Like all other systemd-nspawn features, this is not
+        a security feature and provides protection against accidental
+        destructive operations only.</para></listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>-M</option></term>
+        <term><option>--machine=</option></term>
+
+        <listitem><para>Sets the machine name for this container. This
+        name may be used to identify this container during its runtime
+        (for example in tools like
+        <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+        and similar), and is used to initialize the container's
+        hostname (which the container can choose to override,
+        however). If not specified, the last component of the root
+        directory path of the container is used, possibly suffixed
+        with a random identifier in case <option>--ephemeral</option>
+        mode is selected. If the root directory selected is the host's
+        root directory the host's hostname is used as default
+        instead.</para></listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>--uuid=</option></term>
+
+        <listitem><para>Set the specified UUID for the container. The
+        init system will initialize
+        <filename>/etc/machine-id</filename> from this if this file is
+        not set yet. Note that this option takes effect only if
+        <filename>/etc/machine-id</filename> in the container is
+        unpopulated.</para></listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>--slice=</option></term>
+
+        <listitem><para>Make the container part of the specified
+        slice, instead of the default
+        <filename>machine.slice</filename>. This is only applies if
+        the machine is run in its own scope unit, i.e. if
+        <option>--keep-unit</option> is not used.</para>
+        </listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>--property=</option></term>
+
+        <listitem><para>Set a unit property on the scope unit to
+        register for the machine. This only applies if the machine is
+        run in its own scope unit, i.e. if
+        <option>--keep-unit</option> is not used. Takes unit property
+        assignments in the same format as <command>systemctl
+        set-property</command>. This is useful to set memory limits
+        and similar for machines.</para>
+        </listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>--private-users=</option></term>
+
+        <listitem><para>Controls user namespacing. If enabled, the container will run with its own private set of UNIX
+        user and group ids (UIDs and GIDs). This involves mapping the private UIDs/GIDs used in the container (starting
+        with the container's root user 0 and up) to a range of UIDs/GIDs on the host that are not used for other
+        purposes (usually in the range beyond the host's UID/GID 65536). The parameter may be specified as follows:</para>
+
+        <orderedlist>
+          <listitem><para>If one or two colon-separated numbers are specified, user namespacing is turned on. The first
+          parameter specifies the first host UID/GID to assign to the container, the second parameter specifies the
+          number of host UIDs/GIDs to assign to the container. If the second parameter is omitted, 65536 UIDs/GIDs are
+          assigned.</para></listitem>
+
+          <listitem><para>If the parameter is omitted, or true, user namespacing is turned on. The UID/GID range to
+          use is determined automatically from the file ownership of the root directory of the container's directory
+          tree. To use this option, make sure to prepare the directory tree in advance, and ensure that all files and
+          directories in it are owned by UIDs/GIDs in the range you'd like to use. Also, make sure that used file ACLs
+          exclusively reference UIDs/GIDs in the appropriate range. If this mode is used the number of UIDs/GIDs
+          assigned to the container for use is 65536, and the UID/GID of the root directory must be a multiple of
+          65536.</para></listitem>
+
+          <listitem><para>If the parameter is false, user namespacing is turned off. This is the default.</para>
+          </listitem>
+
+          <listitem><para>The special value <literal>pick</literal> turns on user namespacing. In this case the UID/GID
+          range is automatically chosen. As first step, the file owner of the root directory of the container's
+          directory tree is read, and it is checked that it is currently not used by the system otherwise (in
+          particular, that no other container is using it). If this check is successful, the UID/GID range determined
+          this way is used, similar to the behavior if "yes" is specified. If the check is not successful (and thus
+          the UID/GID range indicated in the root directory's file owner is already used elsewhere) a new – currently
+          unused – UID/GID range of 65536 UIDs/GIDs is randomly chosen between the host UID/GIDs of 524288 and
+          1878982656, always starting at a multiple of 65536. This setting implies
+          <option>--private-users-chown</option> (see below), which has the effect that the files and directories in
+          the container's directory tree will be owned by the appropriate users of the range picked. Using this option
+          makes user namespace behavior fully automatic. Note that the first invocation of a previously unused
+          container image might result in picking a new UID/GID range for it, and thus in the (possibly expensive) file
+          ownership adjustment operation. However, subsequent invocations of the container will be cheap (unless of
+          course the picked UID/GID range is assigned to a different use by then).</para></listitem>
+        </orderedlist>
+
+        <para>It is recommended to assign at least 65536 UIDs/GIDs to each container, so that the usable UID/GID range in the
+        container covers 16 bit. For best security, do not assign overlapping UID/GID ranges to multiple containers. It is
+        hence a good idea to use the upper 16 bit of the host 32-bit UIDs/GIDs as container identifier, while the lower 16
+        bit encode the container UID/GID used. This is in fact the behavior enforced by the
+        <option>--private-users=pick</option> option.</para>
+
+        <para>When user namespaces are used, the GID range assigned to each container is always chosen identical to the
+        UID range.</para>
+
+        <para>In most cases, using <option>--private-users=pick</option> is the recommended option as it enhances
+        container security massively and operates fully automatically in most cases.</para>
+
+        <para>Note that the picked UID/GID range is not written to <filename>/etc/passwd</filename> or
+        <filename>/etc/group</filename>. In fact, the allocation of the range is not stored persistently anywhere,
+        except in the file ownership of the files and directories of the container.</para></listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>--private-users-chown</option></term>
+
+        <listitem><para>If specified, all files and directories in the container's directory tree will adjusted so that
+        they are owned to the appropriate UIDs/GIDs selected for the container (see above). This operation is
+        potentially expensive, as it involves descending and iterating through the full directory tree of the
+        container. Besides actual file ownership, file ACLs are adjusted as well.</para>
+
+        <para>This option is implied if <option>--private-users=pick</option> is used. This option has no effect if
+        user namespacing is not used.</para></listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>-U</option></term>
+
+        <listitem><para>If the kernel supports the user namespaces feature, equivalent to
+        <option>--private-users=pick --private-users-chown</option>, otherwise equivalent to
+        <option>--private-users=no</option>.</para>
+
+        <para>Note that <option>-U</option> is the default if the
+        <filename>systemd-nspawn@.service</filename> template unit file is used.</para>
+
+        <para>Note: it is possible to undo the effect of <option>--private-users-chown</option> (or
+        <option>-U</option>) on the file system by redoing the operation with the first UID of 0:</para>
+
+        <programlisting>systemd-nspawn … --private-users=0 --private-users-chown</programlisting>
+        </listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>--private-network</option></term>
+
+        <listitem><para>Disconnect networking of the container from
+        the host. This makes all network interfaces unavailable in the
+        container, with the exception of the loopback device and those
+        specified with <option>--network-interface=</option> and
+        configured with <option>--network-veth</option>. If this
+        option is specified, the CAP_NET_ADMIN capability will be
+        added to the set of capabilities the container retains. The
+        latter may be disabled by using
+        <option>--drop-capability=</option>.</para></listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>--network-interface=</option></term>
+
+        <listitem><para>Assign the specified network interface to the
+        container. This will remove the specified interface from the
+        calling namespace and place it in the container. When the
+        container terminates, it is moved back to the host namespace.
+        Note that <option>--network-interface=</option> implies
+        <option>--private-network</option>. This option may be used
+        more than once to add multiple network interfaces to the
+        container.</para></listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>--network-macvlan=</option></term>
+
+        <listitem><para>Create a <literal>macvlan</literal> interface
+        of the specified Ethernet network interface and add it to the
+        container. A <literal>macvlan</literal> interface is a virtual
+        interface that adds a second MAC address to an existing
+        physical Ethernet link. The interface in the container will be
+        named after the interface on the host, prefixed with
+        <literal>mv-</literal>. Note that
+        <option>--network-macvlan=</option> implies
+        <option>--private-network</option>. This option may be used
+        more than once to add multiple network interfaces to the
+        container.</para></listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>--network-ipvlan=</option></term>
+
+        <listitem><para>Create an <literal>ipvlan</literal> interface
+        of the specified Ethernet network interface and add it to the
+        container. An <literal>ipvlan</literal> interface is a virtual
+        interface, similar to a <literal>macvlan</literal> interface,
+        which uses the same MAC address as the underlying interface.
+        The interface in the container will be named after the
+        interface on the host, prefixed with <literal>iv-</literal>.
+        Note that <option>--network-ipvlan=</option> implies
+        <option>--private-network</option>. This option may be used
+        more than once to add multiple network interfaces to the
+        container.</para></listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>-n</option></term>
+        <term><option>--network-veth</option></term>
+
+        <listitem><para>Create a virtual Ethernet link (<literal>veth</literal>) between host and container. The host
+        side of the Ethernet link will be available as a network interface named after the container's name (as
+        specified with <option>--machine=</option>), prefixed with <literal>ve-</literal>. The container side of the
+        Ethernet link will be named <literal>host0</literal>. The <option>--network-veth</option> option implies
+        <option>--private-network</option>.</para>
+
+        <para>Note that
+        <citerefentry><refentrytitle>systemd-networkd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
+        includes by default a network file <filename>/usr/lib/systemd/network/80-container-ve.network</filename>
+        matching the host-side interfaces created this way, which contains settings to enable automatic address
+        provisioning on the created virtual link via DHCP, as well as automatic IP routing onto the host's external
+        network interfaces. It also contains <filename>/usr/lib/systemd/network/80-container-host0.network</filename>
+        matching the container-side interface created this way, containing settings to enable client side address
+        assignment via DHCP. In case <filename>systemd-networkd</filename> is running on both the host and inside the
+        container, automatic IP communication from the container to the host is thus available, with further
+        connectivity to the external network.</para>
+
+        <para>Note that <option>--network-veth</option> is the default if the
+        <filename>systemd-nspawn@.service</filename> template unit file is used.</para>
+        </listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>--network-veth-extra=</option></term>
+
+        <listitem><para>Adds an additional virtual Ethernet link
+        between host and container. Takes a colon-separated pair of
+        host interface name and container interface name. The latter
+        may be omitted in which case the container and host sides will
+        be assigned the same name. This switch is independent of
+        <option>--network-veth</option>, and — in contrast — may be
+        used multiple times, and allows configuration of the network
+        interface names. Note that <option>--network-bridge=</option>
+        has no effect on interfaces created with
+        <option>--network-veth-extra=</option>.</para></listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>--network-bridge=</option></term>
+
+        <listitem><para>Adds the host side of the Ethernet link created with <option>--network-veth</option> to the
+        specified Ethernet bridge interface. Expects a valid network interface name of a bridge device as
+        argument. Note that <option>--network-bridge=</option> implies <option>--network-veth</option>. If this option
+        is used, the host side of the Ethernet link will use the <literal>vb-</literal> prefix instead of
+        <literal>ve-</literal>.</para></listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>--network-zone=</option></term>
+
+        <listitem><para>Creates a virtual Ethernet link (<literal>veth</literal>) to the container and adds it to an
+        automatically managed Ethernet bridge interface. The bridge interface is named after the passed argument,
+        prefixed with <literal>vz-</literal>. The bridge interface is automatically created when the first container
+        configured for its name is started, and is automatically removed when the last container configured for its
+        name exits. Hence, each bridge interface configured this way exists only as long as there's at least one
+        container referencing it running. This option is very similar to <option>--network-bridge=</option>, besides
+        this automatic creation/removal of the bridge device.</para>
+
+        <para>This setting makes it easy to place multiple related containers on a common, virtual Ethernet-based
+        broadcast domain, here called a "zone". Each container may only be part of one zone, but each zone may contain
+        any number of containers. Each zone is referenced by its name. Names may be chosen freely (as long as they form
+        valid network interface names when prefixed with <literal>vz-</literal>), and it is sufficient to pass the same
+        name to the <option>--network-zones=</option> switch of the various concurrently running containers to join
+        them in one zone.</para>
+
+        <para>Note that
+        <citerefentry><refentrytitle>systemd-networkd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
+        includes by default a network file <filename>/usr/lib/systemd/network/80-container-vz.network</filename>
+        matching the bridge interfaces created this way, which contains settings to enable automatic address
+        provisioning on the created virtual network via DHCP, as well as automatic IP routing onto the host's external
+        network interfaces. Using <option>--network-zone=</option> is hence in most cases fully automatic and
+        sufficient to connect multiple local containers in a joined broadcast domain to the host, with further
+        connectivity to the external network.</para>
+        </listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>-p</option></term>
+        <term><option>--port=</option></term>
+
+        <listitem><para>If private networking is enabled, maps an IP
+        port on the host onto an IP port on the container. Takes a
+        protocol specifier (either <literal>tcp</literal> or
+        <literal>udp</literal>), separated by a colon from a host port
+        number in the range 1 to 65535, separated by a colon from a
+        container port number in the range from 1 to 65535. The
+        protocol specifier and its separating colon may be omitted, in
+        which case <literal>tcp</literal> is assumed. The container
+        port number and its colon may be omitted, in which case the
+        same port as the host port is implied. This option is only
+        supported if private networking is used, such as with
+        <option>--network-veth</option>, <option>--network-zone=</option>
+        <option>--network-bridge=</option>.</para></listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>-Z</option></term>
+        <term><option>--selinux-context=</option></term>
+
+        <listitem><para>Sets the SELinux security context to be used
+        to label processes in the container.</para>
+        </listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>-L</option></term>
+        <term><option>--selinux-apifs-context=</option></term>
+
+        <listitem><para>Sets the SELinux security context to be used
+        to label files in the virtual API file systems in the
+        container.</para>
+        </listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>--capability=</option></term>
+
+        <listitem><para>List one or more additional capabilities to
+        grant the container. Takes a comma-separated list of
+        capability names, see
+        <citerefentry project='man-pages'><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>
+        for more information. Note that the following capabilities
+        will be granted in any way: CAP_CHOWN, CAP_DAC_OVERRIDE,
+        CAP_DAC_READ_SEARCH, CAP_FOWNER, CAP_FSETID, CAP_IPC_OWNER,
+        CAP_KILL, CAP_LEASE, CAP_LINUX_IMMUTABLE,
+        CAP_NET_BIND_SERVICE, CAP_NET_BROADCAST, CAP_NET_RAW,
+        CAP_SETGID, CAP_SETFCAP, CAP_SETPCAP, CAP_SETUID,
+        CAP_SYS_ADMIN, CAP_SYS_CHROOT, CAP_SYS_NICE, CAP_SYS_PTRACE,
+        CAP_SYS_TTY_CONFIG, CAP_SYS_RESOURCE, CAP_SYS_BOOT,
+        CAP_AUDIT_WRITE, CAP_AUDIT_CONTROL. Also CAP_NET_ADMIN is
+        retained if <option>--private-network</option> is specified.
+        If the special value <literal>all</literal> is passed, all
+        capabilities are retained.</para></listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>--drop-capability=</option></term>
+
+        <listitem><para>Specify one or more additional capabilities to
+        drop for the container. This allows running the container with
+        fewer capabilities than the default (see
+        above).</para></listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>--kill-signal=</option></term>
+
+        <listitem><para>Specify the process signal to send to the
+        container's PID 1 when nspawn itself receives SIGTERM, in
+        order to trigger an orderly shutdown of the
+        container. Defaults to SIGRTMIN+3 if <option>--boot</option>
+        is used (on systemd-compatible init systems SIGRTMIN+3
+        triggers an orderly shutdown). For a list of valid signals, see
+        <citerefentry project='man-pages'><refentrytitle>signal</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para></listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>--link-journal=</option></term>
+
+        <listitem><para>Control whether the container's journal shall
+        be made visible to the host system. If enabled, allows viewing
+        the container's journal files from the host (but not vice
+        versa). Takes one of <literal>no</literal>,
+        <literal>host</literal>, <literal>try-host</literal>,
+        <literal>guest</literal>, <literal>try-guest</literal>,
+        <literal>auto</literal>. If <literal>no</literal>, the journal
+        is not linked. If <literal>host</literal>, the journal files
+        are stored on the host file system (beneath
+        <filename>/var/log/journal/<replaceable>machine-id</replaceable></filename>)
+        and the subdirectory is bind-mounted into the container at the
+        same location. If <literal>guest</literal>, the journal files
+        are stored on the guest file system (beneath
+        <filename>/var/log/journal/<replaceable>machine-id</replaceable></filename>)
+        and the subdirectory is symlinked into the host at the same
+        location. <literal>try-host</literal> and
+        <literal>try-guest</literal> do the same but do not fail if
+        the host does not have persistent journaling enabled. If
+        <literal>auto</literal> (the default), and the right
+        subdirectory of <filename>/var/log/journal</filename> exists,
+        it will be bind mounted into the container. If the
+        subdirectory does not exist, no linking is performed.
+        Effectively, booting a container once with
+        <literal>guest</literal> or <literal>host</literal> will link
+        the journal persistently if further on the default of
+        <literal>auto</literal> is used.</para>
+
+        <para>Note that <option>--link-journal=try-guest</option> is the default if the
+        <filename>systemd-nspawn@.service</filename> template unit file is used.</para></listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>-j</option></term>
+
+        <listitem><para>Equivalent to
+        <option>--link-journal=try-guest</option>.</para></listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>--read-only</option></term>
+
+        <listitem><para>Mount the root file system read-only for the
+        container.</para></listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>--bind=</option></term>
+        <term><option>--bind-ro=</option></term>
+
+        <listitem><para>Bind mount a file or directory from the host
+        into the container. Takes one of: a path argument — in which
+        case the specified path will be mounted from the host to the
+        same path in the container —, or a colon-separated pair of
+        paths — in which case the first specified path is the source
+        in the host, and the second path is the destination in the
+        container —, or a colon-separated triple of source path,
+        destination path and mount options. Mount options are
+        comma-separated and currently, only "rbind" and "norbind"
+        are allowed. Defaults to "rbind". Backslash escapes are interpreted, so
+        <literal>\:</literal> may be used to embed colons in either path.
+        This option may be specified multiple times for
+        creating multiple independent bind mount points. The
+        <option>--bind-ro=</option> option creates read-only bind
+        mounts.</para></listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>--tmpfs=</option></term>
+
+        <listitem><para>Mount a tmpfs file system into the container.
+        Takes a single absolute path argument that specifies where to
+        mount the tmpfs instance to (in which case the directory
+        access mode will be chosen as 0755, owned by root/root), or
+        optionally a colon-separated pair of path and mount option
+        string that is used for mounting (in which case the kernel
+        default for access mode and owner will be chosen, unless
+        otherwise specified). This option is particularly useful for
+        mounting directories such as <filename>/var</filename> as
+        tmpfs, to allow state-less systems, in particular when
+        combined with <option>--read-only</option>.
+        Backslash escapes are interpreted in the path, so
+        <literal>\:</literal> may be used to embed colons in the path.
+        </para></listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>--overlay=</option></term>
+        <term><option>--overlay-ro=</option></term>
+
+        <listitem><para>Combine multiple directory trees into one
+        overlay file system and mount it into the container. Takes a
+        list of colon-separated paths to the directory trees to
+        combine and the destination mount point.</para>
+
+        <para>Backslash escapes are interpreted in the paths, so
+        <literal>\:</literal> may be used to embed colons in the paths.
+        </para>
+
+        <para>If three or more paths are specified, then the last
+        specified path is the destination mount point in the
+        container, all paths specified before refer to directory trees
+        on the host and are combined in the specified order into one
+        overlay file system. The left-most path is hence the lowest
+        directory tree, the second-to-last path the highest directory
+        tree in the stacking order. If <option>--overlay-ro=</option>
+        is used instead of <option>--overlay=</option>, a read-only
+        overlay file system is created. If a writable overlay file
+        system is created, all changes made to it are written to the
+        highest directory tree in the stacking order, i.e. the
+        second-to-last specified.</para>
+
+        <para>If only two paths are specified, then the second
+        specified path is used both as the top-level directory tree in
+        the stacking order as seen from the host, as well as the mount
+        point for the overlay file system in the container. At least
+        two paths have to be specified.</para>
+
+        <para>For details about overlay file systems, see <ulink
+        url="https://www.kernel.org/doc/Documentation/filesystems/overlayfs.txt">overlayfs.txt</ulink>. Note
+        that the semantics of overlay file systems are substantially
+        different from normal file systems, in particular regarding
+        reported device and inode information. Device and inode
+        information may change for a file while it is being written
+        to, and processes might see out-of-date versions of files at
+        times. Note that this switch automatically derives the
+        <literal>workdir=</literal> mount option for the overlay file
+        system from the top-level directory tree, making it a sibling
+        of it. It is hence essential that the top-level directory tree
+        is not a mount point itself (since the working directory must
+        be on the same file system as the top-most directory
+        tree). Also note that the <literal>lowerdir=</literal> mount
+        option receives the paths to stack in the opposite order of
+        this switch.</para></listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>-E <replaceable>NAME</replaceable>=<replaceable>VALUE</replaceable></option></term>
+        <term><option>--setenv=<replaceable>NAME</replaceable>=<replaceable>VALUE</replaceable></option></term>
+
+        <listitem><para>Specifies an environment variable assignment
+        to pass to the init process in the container, in the format
+        <literal>NAME=VALUE</literal>. This may be used to override
+        the default variables or to set additional variables. This
+        parameter may be used more than once.</para></listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>--register=</option></term>
+
+        <listitem><para>Controls whether the container is registered
+        with
+        <citerefentry><refentrytitle>systemd-machined</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
+        Takes a boolean argument, which defaults to <literal>yes</literal>.
+        This option should be enabled when the container runs a full
+        Operating System (more specifically: an init system), and is
+        useful to ensure that the container is accessible via
+        <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+        and shown by tools such as
+        <citerefentry project='man-pages'><refentrytitle>ps</refentrytitle><manvolnum>1</manvolnum></citerefentry>.
+        If the container does not run an init system, it is
+        recommended to set this option to <literal>no</literal>.</para></listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>--keep-unit</option></term>
+
+        <listitem><para>Instead of creating a transient scope unit to
+        run the container in, simply register the service or scope
+        unit <command>systemd-nspawn</command> has been invoked in
+        with
+        <citerefentry><refentrytitle>systemd-machined</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
+        This has no effect if <option>--register=no</option> is used.
+        This switch should be used if
+        <command>systemd-nspawn</command> is invoked from within a
+        service unit, and the service unit's sole purpose is to run a
+        single <command>systemd-nspawn</command> container. This
+        option is not available if run from a user
+        session.</para></listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>--personality=</option></term>
+
+        <listitem><para>Control the architecture ("personality")
+        reported by
+        <citerefentry project='man-pages'><refentrytitle>uname</refentrytitle><manvolnum>2</manvolnum></citerefentry>
+        in the container. Currently, only <literal>x86</literal> and
+        <literal>x86-64</literal> are supported. This is useful when
+        running a 32-bit container on a 64-bit host. If this setting
+        is not used, the personality reported in the container is the
+        same as the one reported on the host.</para></listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>-q</option></term>
+        <term><option>--quiet</option></term>
+
+        <listitem><para>Turns off any status output by the tool
+        itself. When this switch is used, the only output from nspawn
+        will be the console output of the container OS
+        itself.</para></listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>--volatile</option></term>
+        <term><option>--volatile=</option><replaceable>MODE</replaceable></term>
+
+        <listitem><para>Boots the container in volatile mode. When no
+        mode parameter is passed or when mode is specified as
+        <option>yes</option>, full volatile mode is enabled. This
+        means the root directory is mounted as a mostly unpopulated
+        <literal>tmpfs</literal> instance, and
+        <filename>/usr</filename> from the OS tree is mounted into it
+        in read-only mode (the system thus starts up with read-only OS
+        image, but pristine state and configuration, any changes
+        are lost on shutdown). When the mode parameter
+        is specified as <option>state</option>, the OS tree is
+        mounted read-only, but <filename>/var</filename> is mounted as
+        a <literal>tmpfs</literal> instance into it (the system thus
+        starts up with read-only OS resources and configuration, but
+        pristine state, and any changes to the latter are lost on
+        shutdown). When the mode parameter is specified as
+        <option>no</option> (the default), the whole OS tree is made
+        available writable.</para>
+
+        <para>Note that setting this to <option>yes</option> or
+        <option>state</option> will only work correctly with
+        operating systems in the container that can boot up with only
+        <filename>/usr</filename> mounted, and are able to populate
+        <filename>/var</filename> automatically, as
+        needed.</para></listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>--settings=</option><replaceable>MODE</replaceable></term>
+
+        <listitem><para>Controls whether
+        <command>systemd-nspawn</command> shall search for and use
+        additional per-container settings from
+        <filename>.nspawn</filename> files. Takes a boolean or the
+        special values <option>override</option> or
+        <option>trusted</option>.</para>
+
+        <para>If enabled (the default), a settings file named after the
+        machine (as specified with the <option>--machine=</option>
+        setting, or derived from the directory or image file name)
+        with the suffix <filename>.nspawn</filename> is searched in
+        <filename>/etc/systemd/nspawn/</filename> and
+        <filename>/run/systemd/nspawn/</filename>. If it is found
+        there, its settings are read and used. If it is not found
+        there, it is subsequently searched in the same directory as the
+        image file or in the immediate parent of the root directory of
+        the container. In this case, if the file is found, its settings
+        will be also read and used, but potentially unsafe settings
+        are ignored. Note that in both these cases, settings on the
+        command line take precedence over the corresponding settings
+        from loaded <filename>.nspawn</filename> files, if both are
+        specified. Unsafe settings are considered all settings that
+        elevate the container's privileges or grant access to
+        additional resources such as files or directories of the
+        host. For details about the format and contents of
+        <filename>.nspawn</filename> files, consult
+        <citerefentry><refentrytitle>systemd.nspawn</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
+
+        <para>If this option is set to <option>override</option>, the
+        file is searched, read and used the same way, however, the order of
+        precedence is reversed: settings read from the
+        <filename>.nspawn</filename> file will take precedence over
+        the corresponding command line options, if both are
+        specified.</para>
+
+        <para>If this option is set to <option>trusted</option>, the
+        file is searched, read and used the same way, but regardless
+        of being found in <filename>/etc/systemd/nspawn/</filename>,
+        <filename>/run/systemd/nspawn/</filename> or next to the image
+        file or container root directory, all settings will take
+        effect, however, command line arguments still take precedence
+        over corresponding settings.</para>
+
+        <para>If disabled, no <filename>.nspawn</filename> file is read
+        and no settings except the ones on the command line are in
+        effect.</para></listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>--notify-ready=</option></term>
+
+        <listitem><para>Configures support for notifications from the container's init process.
+        <option>--notify-ready=</option> takes a boolean (<option>no</option> and  <option>yes</option>).
+        With option <option>no</option> systemd-nspawn notifies systemd
+        with a <literal>READY=1</literal> message when the init process is created.
+        With option <option>yes</option> systemd-nspawn waits for the
+        <literal>READY=1</literal> message from the init process in the container
+        before sending its own to systemd. For more details about notifications
+        see <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>).</para></listitem>
+      </varlistentry>
+
+      <xi:include href="standard-options.xml" xpointer="help" />
+      <xi:include href="standard-options.xml" xpointer="version" />
+    </variablelist>
+
+  </refsect1>
+
+  <refsect1>
+    <title>Examples</title>
+
+    <example>
+      <title>Build and boot a minimal BLAG distribution in a container</title>
+
+      <programlisting># dnf -y --releasever=210k --installroot=/srv/mycontainer --disablerepo='*' --enablerepo=blag --enablerepo=updates install systemd passwd dnf blag-release vim-minimal
+# systemd-nspawn -bD /srv/mycontainer</programlisting>
+
+      <para>This installs a minimal BLAG distribution into the
+      directory <filename noindex='true'>/srv/mycontainer/</filename>
+      and then boots an OS in a namespace container in it.</para>
+    </example>
+
+    <example>
+      <title>Spawn a shell in a container of a minimal gNewSense Ucclia distribution</title>
+
+      <programlisting># debootstrap --arch=amd64 ucclia ~/gnewsense-tree/
+# systemd-nspawn -D ~/gnewsense-tree/</programlisting>
+
+      <para>This installs a minimal gNewSense unstable distribution into
+      the directory <filename>~/gnewsense-tree/</filename> and then
+      spawns a shell in a namespace container in it.</para>
+    </example>
+
+    <example>
+      <title>Boot a minimal Parabola distribution in a container</title>
+
+      <programlisting># pacstrap -c -d ~/parabola-tree/ base
+# systemd-nspawn -bD ~/parabola-tree/</programlisting>
+
+      <para>This installs a minimal Parabola distribution into the
+      directory <filename>~/parabola-tree/</filename> and then boots an OS
+      in a namespace container in it.</para>
+    </example>
+
+    <example>
+      <title>Boot into an ephemeral <literal>btrfs</literal> snapshot of the host system</title>
+
+      <programlisting># systemd-nspawn -D / -xb</programlisting>
+
+      <para>This runs a copy of the host system in a
+      <literal>btrfs</literal> snapshot which is removed immediately
+      when the container exits. All file system changes made during
+      runtime will be lost on shutdown, hence.</para>
+    </example>
+
+    <example>
+      <title>Run a container with SELinux sandbox security contexts</title>
+
+      <programlisting># chcon system_u:object_r:svirt_sandbox_file_t:s0:c0,c1 -R /srv/container
+# systemd-nspawn -L system_u:object_r:svirt_sandbox_file_t:s0:c0,c1 -Z system_u:system_r:svirt_lxc_net_t:s0:c0,c1 -D /srv/container /bin/sh</programlisting>
+    </example>
+  </refsect1>
+
+  <refsect1>
+    <title>Exit status</title>
+
+    <para>The exit code of the program executed in the container is
+    returned.</para>
+  </refsect1>
+
+  <refsect1>
+    <title>See Also</title>
+    <para>
+      <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+      <citerefentry><refentrytitle>systemd.nspawn</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+      <citerefentry project='man-pages'><refentrytitle>chroot</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+      <citerefentry project='mankier'><refentrytitle>dnf</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
+      <citerefentry project='die-net'><refentrytitle>debootstrap</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
+      <citerefentry project='archlinux'><refentrytitle>pacman</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
+      <citerefentry><refentrytitle>systemd.slice</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+      <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+      <citerefentry project='man-pages'><refentrytitle>btrfs</refentrytitle><manvolnum>8</manvolnum></citerefentry>
+    </para>
+  </refsect1>
+
+</refentry>
diff --git a/src/systemd-nspawn/systemd-nspawn@.service.in b/src/systemd-nspawn/systemd-nspawn@.service.in
new file mode 100644
index 0000000000..c8141639b6
--- /dev/null
+++ b/src/systemd-nspawn/systemd-nspawn@.service.in
@@ -0,0 +1,39 @@
+#  This file is part of systemd.
+#
+#  systemd is free software; you can redistribute it and/or modify it
+#  under the terms of the GNU Lesser General Public License as published by
+#  the Free Software Foundation; either version 2.1 of the License, or
+#  (at your option) any later version.
+
+[Unit]
+Description=Container %i
+Documentation=man:systemd-nspawn(1)
+PartOf=machines.target
+Before=machines.target
+After=network.target
+
+[Service]
+ExecStart=@bindir@/systemd-nspawn --quiet --keep-unit --boot --link-journal=try-guest --network-veth -U --settings=override --machine=%i
+KillMode=mixed
+Type=notify
+RestartForceExitStatus=133
+SuccessExitStatus=133
+Slice=machine.slice
+Delegate=yes
+TasksMax=16384
+
+# Enforce a strict device policy, similar to the one nspawn configures
+# when it allocates its own scope unit. Make sure to keep these
+# policies in sync if you change them!
+DevicePolicy=closed
+DeviceAllow=/dev/net/tun rwm
+DeviceAllow=char-pts rw
+
+# nspawn itself needs access to /dev/loop-control and /dev/loop, to
+# implement the --image= option. Add these here, too.
+DeviceAllow=/dev/loop-control rw
+DeviceAllow=block-loop rw
+DeviceAllow=block-blkext rw
+
+[Install]
+WantedBy=machines.target
diff --git a/src/systemd-nspawn/test-patch-uid.c b/src/systemd-nspawn/test-patch-uid.c
new file mode 100644
index 0000000000..4297fea6fe
--- /dev/null
+++ b/src/systemd-nspawn/test-patch-uid.c
@@ -0,0 +1,62 @@
+/***
+  This file is part of systemd.
+
+  Copyright 2016 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <stdlib.h>
+
+#include "systemd-basic/log.h"
+#include "systemd-basic/user-util.h"
+#include "systemd-basic/util.h"
+
+#include "nspawn-patch-uid.h"
+
+int main(int argc, char *argv[]) {
+        uid_t shift, range;
+        int r;
+
+        log_set_max_level(LOG_DEBUG);
+        log_parse_environment();
+        log_open();
+
+        if (argc != 4) {
+                log_error("Expected PATH SHIFT RANGE parameters.");
+                return EXIT_FAILURE;
+        }
+
+        r = parse_uid(argv[2], &shift);
+        if (r < 0) {
+                log_error_errno(r, "Failed to parse UID shift %s.", argv[2]);
+                return EXIT_FAILURE;
+        }
+
+        r = parse_gid(argv[3], &range);
+        if (r < 0) {
+                log_error_errno(r, "Failed to parse UID range %s.", argv[3]);
+                return EXIT_FAILURE;
+        }
+
+        r = path_patch_uid(argv[1], shift, range);
+        if (r < 0) {
+                log_error_errno(r, "Failed to patch directory tree: %m");
+                return EXIT_FAILURE;
+        }
+
+        log_info("Changed: %s", yes_no(r));
+
+        return EXIT_SUCCESS;
+}