./move.sh

20 files changed, 7124 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..5ec68fb205
--- /dev/null
+++ b/src/systemd-nspawn/Makefile
@@ -0,0 +1,70 @@
+#  -*- 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
+
+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-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/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 = \
+	$(AM_CFLAGS) \
+	$(BLKID_CFLAGS) \
+	$(SECCOMP_CFLAGS)
+
+systemd_nspawn_LDADD = \
+	libshared.la \
+	$(BLKID_LIBS)
+
+ifneq ($(HAVE_LIBIPTC),)
+systemd_nspawn_LDADD += \
+	libfirewall.la
+endif # HAVE_LIBIPTC
+
+$(eval $(value automake2autothing))
+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..1db5ba7116
--- /dev/null
+++ b/src/systemd-nspawn/nspawn-cgroup.c
@@ -0,0 +1,163 @@
+/***
+  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 "alloc-util.h"
+#include "cgroup-util.h"
+#include "fd-util.h"
+#include "fileio.h"
+#include "mkdir.h"
+#include "nspawn-cgroup.h"
+#include "string-util.h"
+#include "strv.h"
+#include "util.h"
+
+int chown_cgroup(pid_t pid, uid_t uid_shift) {
+        _cleanup_free_ char *path = NULL, *fs = NULL;
+        _cleanup_close_ int fd = -1;
+        const char *fn;
+        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");
+
+        fd = open(fs, O_RDONLY|O_CLOEXEC|O_DIRECTORY);
+        if (fd < 0)
+                return log_error_errno(errno, "Failed to open %s: %m", fs);
+
+        FOREACH_STRING(fn,
+                       ".",
+                       "tasks",
+                       "notify_on_release",
+                       "cgroup.procs",
+                       "cgroup.events",
+                       "cgroup.clone_children",
+                       "cgroup.controllers",
+                       "cgroup.subtree_control",
+                       "cgroup.populated")
+                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 sync_cgroup(pid_t pid, bool unified_requested) {
+        _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();
+        if (unified < 0)
+                return log_error_errno(unified, "Failed to determine whether the unified hierachy is used: %m");
+
+        if ((unified > 0) == unified_requested)
+                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("cgroup", tree, "cgroup", MS_NOSUID|MS_NOEXEC|MS_NODEV, "none,name=systemd,xattr");
+        else
+                r = mount("cgroup", tree, "cgroup", MS_NOSUID|MS_NOEXEC|MS_NODEV, "__DEVEL__sane_behavior");
+        if (r < 0) {
+                r = log_error_errno(errno, "Failed to mount unified hierarchy: %m");
+                goto finish;
+        }
+
+        undo_mount = true;
+
+        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");
+
+finish:
+        if (undo_mount)
+                (void) umount(tree);
+
+        (void) rmdir(tree);
+        return r;
+}
+
+int create_subcgroup(pid_t pid, bool unified_requested) {
+        _cleanup_free_ char *cgroup = NULL;
+        const char *child;
+        int unified, r;
+        CGroupMask supported;
+
+        /* In the unified hierarchy inner nodes may only 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)
+                return 0;
+
+        unified = cg_unified();
+        if (unified < 0)
+                return log_error_errno(unified, "Failed to determine whether the unified hierachy 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..1ff35a299a
--- /dev/null
+++ b/src/systemd-nspawn/nspawn-cgroup.h
@@ -0,0 +1,27 @@
+#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>
+
+int chown_cgroup(pid_t pid, uid_t uid_shift);
+int sync_cgroup(pid_t pid, bool unified_requested);
+int create_subcgroup(pid_t pid, bool 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..8122a14f7b
--- /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 <systemd/sd-netlink.h>
+
+#include "alloc-util.h"
+#include "fd-util.h"
+#include "firewall-util.h"
+#include "in-addr-util.h"
+#include "local-addresses.h"
+#include "netlink-util.h"
+#include "nspawn-expose-ports.h"
+#include "parse-util.h"
+#include "socket-util.h"
+#include "string-util.h"
+#include "util.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..0e9f8f7e88
--- /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/sd-netlink.h>
+
+#include "in-addr-util.h"
+#include "list.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..116655cdd2
--- /dev/null
+++ b/src/systemd-nspawn/nspawn-gperf.gperf
@@ -0,0 +1,41 @@
+%{
+#include <stddef.h>
+#include "conf-parser.h"
+#include "nspawn-settings.h"
+#include "nspawn-expose-ports.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)
+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
+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_string,        0, offsetof(Settings, network_bridge)
+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..70cca15278
--- /dev/null
+++ b/src/systemd-nspawn/nspawn-mount.c
@@ -0,0 +1,942 @@
+/***
+  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 "alloc-util.h"
+#include "cgroup-util.h"
+#include "escape.h"
+#include "fs-util.h"
+#include "label.h"
+#include "mkdir.h"
+#include "mount-util.h"
+#include "nspawn-mount.h"
+#include "parse-util.h"
+#include "path-util.h"
+#include "rm-rf.h"
+#include "set.h"
+#include "stat-util.h"
+#include "string-util.h"
+#include "strv.h"
+#include "user-util.h"
+#include "util.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,
+                const char *selinux_apifs_context,
+                char **ret) {
+
+        char *buf = NULL;
+
+        if (userns && uid_shift != 0) {
+                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
+
+        *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);
+
+        if (mount("sysfs", full, "sysfs", MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV, NULL) < 0)
+                return log_error_errno(errno, "Failed to mount sysfs to %s: %m", full);
+
+        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);
+
+                if (mount(from, to, NULL, MS_BIND, NULL) < 0)
+                        return log_error_errno(errno, "Failed to mount /sys/%s into place: %m", x);
+
+                if (mount(NULL, to, NULL, MS_BIND|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT, NULL) < 0)
+                        return log_error_errno(errno, "Failed to mount /sys/%s read-only: %m", x);
+        }
+
+        if (umount(full) < 0)
+                return log_error_errno(errno, "Failed to unmount %s: %m", full);
+
+        if (rmdir(full) < 0)
+                return log_error_errno(errno, "Failed to remove %s: %m", full);
+
+        x = prefix_roota(top, "/fs/kdbus");
+        (void) mkdir(x, 0755);
+
+        if (mount(NULL, top, NULL, MS_BIND|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT, NULL) < 0)
+                return log_error_errno(errno, "Failed to make %s read-only: %m", top);
+
+        return 0;
+}
+
+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 */
+                { 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 */
+                { "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_p(where, 0755);
+                if (r < 0) {
+                        if (mount_table[k].fatal)
+                                return log_error_errno(r, "Failed to create directory %s: %m", where);
+
+                        log_warning_errno(r, "Failed to create directory %s: %m", where);
+                        continue;
+                }
+
+                o = mount_table[k].options;
+                if (streq_ptr(mount_table[k].type, "tmpfs")) {
+                        r = tmpfs_patch_options(o, use_userns, uid_shift, uid_range, selinux_apifs_context, &options);
+                        if (r < 0)
+                                return log_oom();
+                        if (r > 0)
+                                o = options;
+                }
+
+                if (mount(mount_table[k].what,
+                          where,
+                          mount_table[k].type,
+                          mount_table[k].flags,
+                          o) < 0) {
+
+                        if (mount_table[k].fatal)
+                                return log_error_errno(errno, "mount(%s) failed: %m", where);
+
+                        log_warning_errno(errno, "mount(%s) failed, ignoring: %m", where);
+                }
+        }
+
+        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);
+        } else {
+                return log_error_errno(errno, "Failed to stat %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 && r != -EEXIST)
+                return log_error_errno(r, "Failed to create mount point %s: %m", where);
+
+        if (mount(m->source, where, NULL, mount_flags, mount_opts) < 0)
+                return log_error_errno(errno, "mount(%s) failed: %m", where);
+
+        if (m->read_only) {
+                r = bind_remount_recursive(where, true);
+                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, selinux_apifs_context, &buf);
+        if (r < 0)
+                return log_oom();
+        options = r > 0 ? buf : m->options;
+
+        if (mount("tmpfs", where, "tmpfs", MS_NODEV|MS_STRICTATIME, options) < 0)
+                return log_error_errno(errno, "tmpfs mount to %s failed: %m", where);
+
+        return 0;
+}
+
+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);
+        }
+
+        if (mount("overlay", where, "overlay", m->read_only ? MS_RDONLY : 0, options) < 0)
+                return log_error_errno(errno, "overlay mount to %s failed: %m", where);
+
+        return 0;
+}
+
+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;
+}
+
+static int mount_legacy_cgroup_hierarchy(const char *dest, const char *controller, const char *hierarchy, bool read_only) {
+        char *to;
+        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 (mount("cgroup", to, "cgroup", MS_NOSUID|MS_NOEXEC|MS_NODEV, controller) < 0)
+                return log_error_errno(errno, "Failed to mount to %s: %m", to);
+
+        /* ... hence let's only make the bind mount read-only, not the
+         * superblock. */
+        if (read_only) {
+                if (mount(NULL, to, NULL, MS_BIND|MS_REMOUNT|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_RDONLY, NULL) < 0)
+                        return log_error_errno(errno, "Failed to remount %s read-only: %m", to);
+        }
+        return 1;
+}
+
+static int mount_legacy_cgroups(
+                const char *dest,
+                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, selinux_apifs_context, &options);
+                if (r < 0)
+                        return log_oom();
+
+                if (mount("tmpfs", cgroup_root, "tmpfs", MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_STRICTATIME, options) < 0)
+                        return log_error_errno(errno, "Failed to mount /sys/fs/cgroup: %m");
+        }
+
+        if (cg_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, 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, true);
+                        if (r < 0)
+                                return r;
+
+                        r = symlink_idempotent(combined, target);
+                        if (r == -EINVAL) {
+                                log_error("Invalid existing symlink for combined hierarchy");
+                                return r;
+                        }
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to create symlink for combined hierarchy: %m");
+                }
+        }
+
+skip_controllers:
+        r = mount_legacy_cgroup_hierarchy(dest, "none,name=systemd,xattr", "systemd", false);
+        if (r < 0)
+                return r;
+
+        if (mount(NULL, cgroup_root, NULL, MS_REMOUNT|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_STRICTATIME|MS_RDONLY, "mode=755") < 0)
+                return log_error_errno(errno, "Failed to remount %s read-only: %m", cgroup_root);
+
+        return 0;
+}
+
+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;
+        }
+
+        if (mount("cgroup", p, "cgroup", MS_NOSUID|MS_NOEXEC|MS_NODEV, "__DEVEL__sane_behavior") < 0)
+                return log_error_errno(errno, "Failed to mount unified cgroup hierarchy to %s: %m", p);
+
+        return 0;
+}
+
+int mount_cgroups(
+                const char *dest,
+                bool unified_requested,
+                bool userns, uid_t uid_shift, uid_t uid_range,
+                const char *selinux_apifs_context) {
+
+        if (unified_requested)
+                return mount_unified_cgroups(dest);
+        else
+                return mount_legacy_cgroups(dest, userns, uid_shift, uid_range, selinux_apifs_context);
+}
+
+int mount_systemd_cgroup_writable(
+                const char *dest,
+                bool 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) {
+                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 */
+        if (mount(systemd_own, systemd_own,  NULL, MS_BIND, NULL) < 0)
+                return log_error_errno(errno, "Failed to turn %s into a bind mount: %m", own_cgroup_path);
+
+        /* And then remount the systemd cgroup root read-only */
+        if (mount(NULL, systemd_root, NULL, MS_BIND|MS_REMOUNT|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_RDONLY, NULL) < 0)
+                return log_error_errno(errno, "Failed to mount cgroup root read-only: %m");
+
+        return 0;
+}
+
+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);
+        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, selinux_apifs_context, &buf);
+        if (r < 0)
+                return log_oom();
+        if (r > 0)
+                options = buf;
+
+        if (mount("tmpfs", p, "tmpfs", MS_STRICTATIME, options) < 0)
+                return log_error_errno(errno, "Failed to mount tmpfs to /var: %m");
+
+        return 0;
+}
+
+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, selinux_apifs_context, &buf);
+        if (r < 0)
+                return log_oom();
+        if (r > 0)
+                options = buf;
+
+        if (mount("tmpfs", template, "tmpfs", MS_STRICTATIME, options) < 0) {
+                r = log_error_errno(errno, "Failed to mount tmpfs for root directory: %m");
+                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;
+        }
+
+        if (mount(f, t, NULL, MS_BIND|MS_REC, NULL) < 0) {
+                r = log_error_errno(errno, "Failed to create /usr bind mount: %m");
+                goto fail;
+        }
+
+        bind_mounted = true;
+
+        r = bind_remount_recursive(t, true);
+        if (r < 0) {
+                log_error_errno(r, "Failed to remount %s read-only: %m", t);
+                goto fail;
+        }
+
+        if (mount(template, directory, NULL, MS_MOVE, NULL) < 0) {
+                r = log_error_errno(errno, "Failed to move root mount: %m");
+                goto fail;
+        }
+
+        (void) rmdir(template);
+
+        return 0;
+
+fail:
+        if (bind_mounted)
+                (void) umount(t);
+
+        if (tmpfs_mounted)
+                (void) umount(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..0daf145412
--- /dev/null
+++ b/src/systemd-nspawn/nspawn-mount.h
@@ -0,0 +1,69 @@
+#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>
+
+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, bool unified_requested, bool userns, uid_t uid_shift, uid_t uid_range, const char *selinux_apifs_context);
+int mount_systemd_cgroup_writable(const char *dest, bool 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..d03fd001a7
--- /dev/null
+++ b/src/systemd-nspawn/nspawn-network.c
@@ -0,0 +1,540 @@
+/***
+  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 <linux/veth.h>
+#include <net/if.h>
+
+#include "libudev.h"
+#include <systemd/sd-id128.h>
+#include <systemd/sd-netlink.h>
+
+#include "alloc-util.h"
+#include "ether-addr-util.h"
+#include "netlink-util.h"
+#include "nspawn-network.h"
+#include "siphash24.h"
+#include "string-util.h"
+#include "udev-util.h"
+#include "util.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 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;
+}
+
+int setup_bridge(const char *veth_name, const char *bridge_name) {
+        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
+        _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL;
+        int r, bridge_ifi;
+
+        assert(veth_name);
+        assert(bridge_name);
+
+        bridge_ifi = (int) if_nametoindex(bridge_name);
+        if (bridge_ifi <= 0)
+                return log_error_errno(errno, "Failed to resolve interface %s: %m", bridge_name);
+
+        r = sd_netlink_open(&rtnl);
+        if (r < 0)
+                return log_error_errno(r, "Failed to connect to netlink: %m");
+
+        r = sd_rtnl_message_new_link(rtnl, &m, RTM_SETLINK, 0);
+        if (r < 0)
+                return log_error_errno(r, "Failed to allocate netlink message: %m");
+
+        r = sd_rtnl_message_link_set_flags(m, IFF_UP, IFF_UP);
+        if (r < 0)
+                return log_error_errno(r, "Failed to set IFF_UP flag: %m");
+
+        r = sd_netlink_message_append_string(m, IFLA_IFNAME, veth_name);
+        if (r < 0)
+                return log_error_errno(r, "Failed to add netlink interface name field: %m");
+
+        r = sd_netlink_message_append_u32(m, IFLA_MASTER, bridge_ifi);
+        if (r < 0)
+                return log_error_errno(r, "Failed to add netlink master field: %m");
+
+        r = sd_netlink_call(rtnl, m, 0, NULL);
+        if (r < 0)
+                return log_error_errno(r, "Failed to add veth interface to bridge: %m");
+
+        return bridge_ifi;
+}
+
+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 || isempty(a))
+                return -EINVAL;
+
+        r = extract_first_word(&p, &b, ":", EXTRACT_DONT_COALESCE_SEPARATORS);
+        if (r < 0)
+                return r;
+        if (r == 0 || isempty(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;
+}
diff --git a/src/systemd-nspawn/nspawn-network.h b/src/systemd-nspawn/nspawn-network.h
new file mode 100644
index 0000000000..9ab1606d1c
--- /dev/null
+++ b/src/systemd-nspawn/nspawn-network.h
@@ -0,0 +1,36 @@
+#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);
+
+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);
diff --git a/src/systemd-nspawn/nspawn-register.c b/src/systemd-nspawn/nspawn-register.c
new file mode 100644
index 0000000000..3b0d778f43
--- /dev/null
+++ b/src/systemd-nspawn/nspawn-register.c
@@ -0,0 +1,235 @@
+/***
+  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 "bus-error.h"
+#include "bus-util.h"
+#include "nspawn-register.h"
+#include "stat-util.h"
+#include "strv.h"
+#include "util.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;
+                char **i;
+                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", "strict");
+                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)", 9,
+                                          /* Allow the container to
+                                           * access and create the API
+                                           * device nodes, so that
+                                           * PrivateDevices= in the
+                                           * container can work
+                                           * fine */
+                                          "/dev/null", "rwm",
+                                          "/dev/zero", "rwm",
+                                          "/dev/full", "rwm",
+                                          "/dev/random", "rwm",
+                                          "/dev/urandom", "rwm",
+                                          "/dev/tty", "rwm",
+                                          "/dev/net/tun", "rwm",
+                                          /* Allow the container
+                                           * access to ptys. However,
+                                           * do not permit the
+                                           * container to ever create
+                                           * these device nodes. */
+                                          "/dev/pts/ptmx", "rw",
+                                          "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);
+                }
+
+                STRV_FOREACH(i, properties) {
+                        r = bus_append_unit_property_assignment(m, *i);
+                        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-settings.c b/src/systemd-nspawn/nspawn-settings.c
new file mode 100644
index 0000000000..4fb0054698
--- /dev/null
+++ b/src/systemd-nspawn/nspawn-settings.c
@@ -0,0 +1,394 @@
+/***
+  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 "alloc-util.h"
+#include "cap-list.h"
+#include "conf-parser.h"
+#include "nspawn-network.h"
+#include "nspawn-settings.h"
+#include "parse-util.h"
+#include "process-util.h"
+#include "strv.h"
+#include "util.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->read_only = -1;
+        s->volatile_mode = _VOLATILE_MODE_INVALID;
+
+        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;
+
+        *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);
+        expose_port_free_all(s->expose_ports);
+
+        custom_mount_free_all(s->custom_mounts, s->n_custom_mounts);
+        free(s);
+
+        return NULL;
+}
+
+bool settings_private_network(Settings *s) {
+        assert(s);
+
+        return
+                s->private_network > 0 ||
+                s->network_veth > 0 ||
+                s->network_bridge ||
+                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;
+}
+
+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_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;
+}
diff --git a/src/systemd-nspawn/nspawn-settings.h b/src/systemd-nspawn/nspawn-settings.h
new file mode 100644
index 0000000000..a017405cd9
--- /dev/null
+++ b/src/systemd-nspawn/nspawn-settings.h
@@ -0,0 +1,101 @@
+#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 "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 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,
+        _SETTINGS_MASK_ALL        = (1 << 13) -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;
+
+        /* [Image] */
+        int read_only;
+        VolatileMode volatile_mode;
+        CustomMount *custom_mounts;
+        unsigned n_custom_mounts;
+
+        /* [Network] */
+        int private_network;
+        int network_veth;
+        char *network_bridge;
+        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_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);
diff --git a/src/systemd-nspawn/nspawn-setuid.c b/src/systemd-nspawn/nspawn-setuid.c
new file mode 100644
index 0000000000..ee15a47e93
--- /dev/null
+++ b/src/systemd-nspawn/nspawn-setuid.c
@@ -0,0 +1,273 @@
+/***
+  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 "alloc-util.h"
+#include "fd-util.h"
+#include "mkdir.h"
+#include "nspawn-setuid.h"
+#include "process-util.h"
+#include "signal-util.h"
+#include "string-util.h"
+#include "user-util.h"
+#include "util.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;
+                }
+
+                log_error_errno(errno, "Failed to read from getent: %m");
+                return -errno;
+        }
+
+        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;
+                }
+
+                log_error_errno(errno, "Failed to read from getent: %m");
+                return -errno;
+        }
+
+        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..2de87e3c63
--- /dev/null
+++ b/src/systemd-nspawn/nspawn-stub-pid1.c
@@ -0,0 +1,170 @@
+/***
+  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 "fd-util.h"
+#include "log.h"
+#include "nspawn-stub-pid1.h"
+#include "process-util.h"
+#include "signal-util.h"
+#include "time-util.h"
+#include "def.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..add66be183
--- /dev/null
+++ b/src/systemd-nspawn/nspawn.c
@@ -0,0 +1,3700 @@
+/***
+  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 <linux/loop.h>
+#include <sched.h>
+#ifdef HAVE_SECCOMP
+#include <seccomp.h>
+#endif
+#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 "alloc-util.h"
+#include "barrier.h"
+#include "base-filesystem.h"
+#include "blkid-util.h"
+#include "btrfs-util.h"
+#include "cap-list.h"
+#include "capability-util.h"
+#include "cgroup-util.h"
+#include "copy.h"
+#include "dev-setup.h"
+#include "env-util.h"
+#include "fd-util.h"
+#include "fdset.h"
+#include "fileio.h"
+#include "formats-util.h"
+#include "fs-util.h"
+#include "gpt.h"
+#include "hostname-util.h"
+#include "log.h"
+#include "loopback-setup.h"
+#include "machine-image.h"
+#include "macro.h"
+#include "missing.h"
+#include "mkdir.h"
+#include "mount-util.h"
+#include "netlink-util.h"
+#include "nspawn-cgroup.h"
+#include "nspawn-expose-ports.h"
+#include "nspawn-mount.h"
+#include "nspawn-network.h"
+#include "nspawn-register.h"
+#include "nspawn-settings.h"
+#include "nspawn-setuid.h"
+#include "nspawn-stub-pid1.h"
+#include "parse-util.h"
+#include "path-util.h"
+#include "process-util.h"
+#include "ptyfwd.h"
+#include "random-util.h"
+#include "rm-rf.h"
+#ifdef HAVE_SECCOMP
+#include "seccomp-util.h"
+#endif
+#include "signal-util.h"
+#include "socket-util.h"
+#include "stat-util.h"
+#include "stdio-util.h"
+#include "string-util.h"
+#include "strv.h"
+#include "terminal-util.h"
+#include "udev-util.h"
+#include "umask-util.h"
+#include "user-util.h"
+#include "util.h"
+
+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_retain =
+        (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_NET_BIND_SERVICE) |
+        (1ULL << CAP_NET_BROADCAST) |
+        (1ULL << CAP_NET_RAW) |
+        (1ULL << CAP_SETGID) |
+        (1ULL << CAP_SETFCAP) |
+        (1ULL << CAP_SETPCAP) |
+        (1ULL << CAP_SETUID) |
+        (1ULL << CAP_SYS_ADMIN) |
+        (1ULL << CAP_SYS_CHROOT) |
+        (1ULL << CAP_SYS_NICE) |
+        (1ULL << CAP_SYS_PTRACE) |
+        (1ULL << CAP_SYS_TTY_CONFIG) |
+        (1ULL << CAP_SYS_RESOURCE) |
+        (1ULL << CAP_SYS_BOOT) |
+        (1ULL << CAP_AUDIT_WRITE) |
+        (1ULL << CAP_AUDIT_CONTROL) |
+        (1ULL << CAP_MKNOD);
+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_share_system = 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 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 uid_t arg_uid_shift = UID_INVALID, arg_uid_range = 0x10000U;
+static bool arg_userns = false;
+static int arg_kill_signal = 0;
+static bool arg_unified_cgroup_hierarchy = false;
+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 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"
+               "     --private-users[=UIDBASE[:NUIDS]]\n"
+               "                            Run within user namespace\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 between host\n"
+               "                            and container and add it to an existing bridge on\n"
+               "                            the host\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"
+               "     --setenv=NAME=VALUE    Pass an environment variable to PID 1\n"
+               "     --share-system         Share system namespaces with host\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"
+               , 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 (arg_userns && arg_uid_shift == UID_INVALID && path_equal(m->destination, "/")) {
+                        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(void) {
+        const char *e;
+        int r;
+
+        /* 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.");
+
+                arg_unified_cgroup_hierarchy = r;
+                return 0;
+        }
+
+        /* Otherwise inherit the default from the host system */
+        r = cg_unified();
+        if (r < 0)
+                return log_error_errno(r, "Failed to determine whether the unified cgroups hierarchy is used: %m");
+
+        arg_unified_cgroup_hierarchy = r;
+        return 0;
+}
+
+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_SETENV,
+                ARG_SHARE_SYSTEM,
+                ARG_REGISTER,
+                ARG_KEEP_UNIT,
+                ARG_NETWORK_INTERFACE,
+                ARG_NETWORK_MACVLAN,
+                ARG_NETWORK_IPVLAN,
+                ARG_NETWORK_BRIDGE,
+                ARG_NETWORK_VETH_EXTRA,
+                ARG_PERSONALITY,
+                ARG_VOLATILE,
+                ARG_TEMPLATE,
+                ARG_PROPERTY,
+                ARG_PRIVATE_USERS,
+                ARG_KILL_SIGNAL,
+                ARG_SETTINGS,
+                ARG_CHDIR,
+        };
+
+        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, ARG_SETENV            },
+                { "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      },
+                { "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    },
+                { "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     },
+                { "kill-signal",           required_argument, NULL, ARG_KILL_SIGNAL       },
+                { "settings",              required_argument, NULL, ARG_SETTINGS          },
+                { "chdir",                 required_argument, NULL, ARG_CHDIR             },
+                {}
+        };
+
+        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:n", 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_BRIDGE:
+                        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 (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 (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 (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) {
+                                log_error("Invalid UUID: %s", optarg);
+                                return r;
+                        }
+
+                        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 ARG_SETENV: {
+                        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:
+                        arg_share_system = true;
+                        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:
+                        if (optarg) {
+                                _cleanup_free_ char *buffer = NULL;
+                                const char *range, *shift;
+
+                                range = strchr(optarg, ':');
+                                if (range) {
+                                        buffer = strndup(optarg, range - optarg);
+                                        if (!buffer)
+                                                return log_oom();
+                                        shift = buffer;
+
+                                        range++;
+                                        if (safe_atou32(range, &arg_uid_range) < 0 || arg_uid_range <= 0) {
+                                                log_error("Failed to parse UID range: %s", range);
+                                                return -EINVAL;
+                                        }
+                                } else
+                                        shift = optarg;
+
+                                if (parse_uid(shift, &arg_uid_shift) < 0) {
+                                        log_error("Failed to parse UID: %s", optarg);
+                                        return -EINVAL;
+                                }
+                        }
+
+                        arg_userns = true;
+                        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 '?':
+                        return -EINVAL;
+
+                default:
+                        assert_not_reached("Unhandled option");
+                }
+
+        if (arg_share_system)
+                arg_register = false;
+
+        if (arg_start_mode != START_PID1 && arg_share_system) {
+                log_error("--boot and --share-system may not be combined.");
+                return -EINVAL;
+        }
+
+        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 && access("/proc/self/uid_map", F_OK) < 0)
+                return log_error_errno(EOPNOTSUPP, "--private-users= is not supported, kernel compiled without user namespace support.");
+
+        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_retain = (arg_retain | plus | (arg_private_network ? 1ULL << CAP_NET_ADMIN : 0)) & ~minus;
+
+        r = detect_unified_cgroup_hierarchy();
+        if (r < 0)
+                return r;
+
+        e = getenv("SYSTEMD_NSPAWN_CONTAINER_SERVICE");
+        if (e)
+                arg_container_service_name = e;
+
+        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;
+        }
+
+        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)
+                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("/etc/localtime is not a symlink, not updating container timezone.");
+                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 char* id128_format_as_uuid(sd_id128_t id, char s[37]) {
+        assert(s);
+
+        snprintf(s, 37,
+                 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
+                 SD_ID128_FORMAT_VAL(id));
+
+        return s;
+}
+
+static int setup_boot_id(const char *dest) {
+        const char *from, *to;
+        sd_id128_t rnd = {};
+        char as_uuid[37];
+        int r;
+
+        if (arg_share_system)
+                return 0;
+
+        /* 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");
+
+        id128_format_as_uuid(rnd, as_uuid);
+
+        r = write_string_file(from, as_uuid, WRITE_STRING_FILE_CREATE);
+        if (r < 0)
+                return log_error_errno(r, "Failed to write boot id: %m");
+
+        if (mount(from, to, NULL, MS_BIND, NULL) < 0)
+                r = log_error_errno(errno, "Failed to bind mount boot id: %m");
+        else if (mount(NULL, to, NULL, MS_BIND|MS_REMOUNT|MS_RDONLY|MS_NOSUID|MS_NODEV, NULL) < 0)
+                log_warning_errno(errno, "Failed to make boot id read-only: %m");
+
+        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) {
+                                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);
+                                if (mount(from, to, NULL, MS_BIND, NULL) < 0)
+                                        return log_error_errno(errno, "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");
+        if (mount("devpts", p, "devpts", MS_NOSUID|MS_NOEXEC, options) < 0)
+                return log_error_errno(errno, "Failed to mount /dev/pts: %m");
+        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");
+
+        if (mount(console, to, NULL, MS_BIND, NULL) < 0)
+                return log_error_errno(errno, "Bind mount for /dev/console failed: %m");
+
+        return 0;
+}
+
+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");
+        if (mount(from, to, NULL, MS_BIND, NULL) < 0)
+                return log_error_errno(errno, "Bind mount for /proc/kmsg failed: %m");
+
+        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_share_system)
+                return 0;
+
+        if (sethostname_idempotent(arg_machine) < 0)
+                return -errno;
+
+        return 0;
+}
+
+static int setup_journal(const char *directory) {
+        sd_id128_t machine_id, this_id;
+        _cleanup_free_ char *b = NULL, *d = NULL;
+        const char *etc_machine_id, *p, *q;
+        bool try;
+        char *id;
+        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;
+
+        etc_machine_id = prefix_roota(directory, "/etc/machine-id");
+
+        r = read_one_line_file(etc_machine_id, &b);
+        if (r == -ENOENT && try)
+                return 0;
+        else if (r < 0)
+                return log_error_errno(r, "Failed to read machine ID from %s: %m", etc_machine_id);
+
+        id = strstrip(b);
+        if (isempty(id) && try)
+                return 0;
+
+        /* Verify validity */
+        r = sd_id128_from_string(id, &machine_id);
+        if (r < 0)
+                return log_error_errno(r, "Failed to parse machine ID from %s: %m", etc_machine_id);
+
+        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(machine_id, this_id)) {
+                log_full(try ? LOG_WARNING : LOG_ERR,
+                         "Host and machine ids are equal (%s): refusing to link journals", 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");
+
+        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);
+
+        if (mount(p, q, NULL, MS_BIND, NULL) < 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_retain, false);
+}
+
+static int reset_audit_loginuid(void) {
+        _cleanup_free_ char *p = NULL;
+        int r;
+
+        if (arg_share_system)
+                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_seccomp(void) {
+
+#ifdef HAVE_SECCOMP
+        static const struct {
+                uint64_t capability;
+                int syscall_num;
+        } blacklist[] = {
+                { CAP_SYS_RAWIO,  SCMP_SYS(iopl)              },
+                { CAP_SYS_RAWIO,  SCMP_SYS(ioperm)            },
+                { CAP_SYS_BOOT,   SCMP_SYS(kexec_load)        },
+                { CAP_SYS_ADMIN,  SCMP_SYS(swapon)            },
+                { CAP_SYS_ADMIN,  SCMP_SYS(swapoff)           },
+                { CAP_SYS_ADMIN,  SCMP_SYS(open_by_handle_at) },
+                { CAP_SYS_MODULE, SCMP_SYS(init_module)       },
+                { CAP_SYS_MODULE, SCMP_SYS(finit_module)      },
+                { CAP_SYS_MODULE, SCMP_SYS(delete_module)     },
+                { CAP_SYSLOG,     SCMP_SYS(syslog)            },
+        };
+
+        scmp_filter_ctx seccomp;
+        unsigned i;
+        int r;
+
+        seccomp = seccomp_init(SCMP_ACT_ALLOW);
+        if (!seccomp)
+                return log_oom();
+
+        r = seccomp_add_secondary_archs(seccomp);
+        if (r < 0) {
+                log_error_errno(r, "Failed to add secondary archs to seccomp filter: %m");
+                goto finish;
+        }
+
+        for (i = 0; i < ELEMENTSOF(blacklist); i++) {
+                if (arg_retain & (1ULL << blacklist[i].capability))
+                        continue;
+
+                r = seccomp_rule_add(seccomp, SCMP_ACT_ERRNO(EPERM), blacklist[i].syscall_num, 0);
+                if (r == -EFAULT)
+                        continue; /* unknown syscall */
+                if (r < 0) {
+                        log_error_errno(r, "Failed to block syscall: %m");
+                        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_attr_set(seccomp, SCMP_FLTATR_CTL_NNP, 0);
+        if (r < 0) {
+                log_error_errno(r, "Failed to unset NO_NEW_PRIVS: %m");
+                goto finish;
+        }
+
+        r = seccomp_load(seccomp);
+        if (r == -EINVAL) {
+                log_debug_errno(r, "Kernel is probably not configured with CONFIG_SECCOMP. Disabling seccomp audit filter: %m");
+                r = 0;
+                goto finish;
+        }
+        if (r < 0) {
+                log_error_errno(r, "Failed to install seccomp audit filter: %m");
+                goto finish;
+        }
+
+finish:
+        seccomp_release(seccomp);
+        return r;
+#else
+        return 0;
+#endif
+
+}
+
+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");
+        if (mount(p, q, NULL, MS_BIND, NULL) < 0)
+                return log_error_errno(errno, "Failed to install propagation bind mount.");
+
+        if (mount(NULL, q, NULL, MS_BIND|MS_REMOUNT|MS_RDONLY, NULL) < 0)
+                return log_error_errno(errno, "Failed to make propagation mount read-only");
+
+        return 0;
+}
+
+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,
+                bool *secondary) {
+
+#ifdef HAVE_BLKID
+        int home_nr = -1, srv_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, *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(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();
+                        }
+#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;
+        }
+
+        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;
+        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 (mount(what, p, fstype, MS_NODEV|(rw ? 0 : MS_RDONLY), NULL) < 0)
+                return log_error_errno(errno, "Failed to mount %s: %m", what);
+
+        return 0;
+#else
+        log_error("--image= is not supported, compiled without blkid support.");
+        return -EOPNOTSUPP;
+#endif
+}
+
+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) {
+        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");
+        }
+
+        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;
+        }
+
+        return r;
+}
+
+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) {
+                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;
+        }
+
+        log_info("Using user namespaces with base " UID_FMT " and range " UID_FMT ".", arg_uid_shift, arg_uid_range);
+        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;
+        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
+        };
+
+        _cleanup_strv_free_ char **env_use = NULL;
+        int r;
+
+        assert(barrier);
+        assert(directory);
+        assert(kmsg_socket >= 0);
+
+        cg_unified_flush();
+
+        if (arg_userns) {
+                /* 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 = mount_all(NULL, arg_userns, true, arg_uid_shift, arg_private_network, 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;
+        }
+
+        r = mount_systemd_cgroup_writable("", arg_unified_cgroup_hierarchy);
+        if (r < 0)
+                return r;
+
+        r = reset_uid_gid();
+        if (r < 0)
+                return log_error_errno(r, "Couldn't become new root: %m");
+
+        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((security_context_t) 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();
+
+        if (!sd_id128_equal(arg_uuid, SD_ID128_NULL)) {
+                char as_uuid[37];
+
+                if (asprintf((char**)(envp + n_env++), "container_uuid=%s", id128_format_as_uuid(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();
+        }
+
+        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 = 1 + strv_length(arg_parameters);
+                a = newa(char*, m + 1);
+                if (strv_isempty(arg_parameters))
+                        a[1] = NULL;
+                else
+                        memcpy(a + 1, arg_parameters, m * sizeof(char*));
+
+                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)
+                        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 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,
+                bool interactive,
+                bool secondary,
+                int pid_socket,
+                int kmsg_socket,
+                int rtnl_socket,
+                int uid_shift_socket,
+                FDSet *fds) {
+
+        pid_t pid;
+        ssize_t l;
+        int r;
+
+        assert(barrier);
+        assert(directory);
+        assert(console);
+        assert(pid_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. */
+        if (mount(NULL, "/", NULL, MS_SLAVE|MS_REC, NULL) < 0)
+                return log_error_errno(errno, "MS_SLAVE|MS_REC failed: %m");
+
+        r = mount_devices(directory,
+                          root_device, root_device_rw,
+                          home_device, home_device_rw,
+                          srv_device, srv_device_rw);
+        if (r < 0)
+                return r;
+
+        r = determine_uid_shift(directory);
+        if (r < 0)
+                return r;
+
+        if (arg_userns) {
+                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;
+                }
+        }
+
+        /* Turn directory into bind mount */
+        if (mount(directory, directory, NULL, MS_BIND|MS_REC, NULL) < 0)
+                return log_error_errno(errno, "Failed to make bind mount: %m");
+
+        r = setup_volatile(directory, arg_volatile_mode, arg_userns, arg_uid_shift, arg_uid_range, arg_selinux_context);
+        if (r < 0)
+                return r;
+
+        r = setup_volatile_state(directory, arg_volatile_mode, arg_userns, 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);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to make tree read-only: %m");
+        }
+
+        r = mount_all(directory, arg_userns, 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();
+        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_journal(directory);
+        if (r < 0)
+                return r;
+
+        r = mount_custom(directory, arg_custom_mounts, arg_n_custom_mounts, arg_userns, arg_uid_shift, arg_uid_range, arg_selinux_apifs_context);
+        if (r < 0)
+                return r;
+
+        r = mount_cgroups(directory, arg_unified_cgroup_hierarchy, arg_userns, arg_uid_shift, arg_uid_range, arg_selinux_apifs_context);
+        if (r < 0)
+                return r;
+
+        r = mount_move_root(directory);
+        if (r < 0)
+                return log_error_errno(r, "Failed to move root directory: %m");
+
+        pid = raw_clone(SIGCHLD|CLONE_NEWNS|
+                        (arg_share_system ? 0 : CLONE_NEWIPC|CLONE_NEWPID|CLONE_NEWUTS) |
+                        (arg_private_network ? CLONE_NEWNET : 0) |
+                        (arg_userns ? CLONE_NEWUSER : 0),
+                        NULL);
+        if (pid < 0)
+                return log_error_errno(errno, "Failed to fork inner child: %m");
+        if (pid == 0) {
+                pid_socket = safe_close(pid_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;
+        }
+
+        pid_socket = safe_close(pid_socket);
+        kmsg_socket = safe_close(kmsg_socket);
+        rtnl_socket = safe_close(rtnl_socket);
+
+        return 0;
+}
+
+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 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_retain |= plus;
+
+                arg_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_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;
+                }
+        }
+
+        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;
+                }
+        }
+
+        return 0;
+}
+
+int main(int argc, char *argv[]) {
+
+        _cleanup_free_ char *device_path = NULL, *root_device = NULL, *home_device = NULL, *srv_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;
+        char veth_name[IFNAMSIZ];
+        bool secondary = false, remove_subvol = false;
+        sigset_t mask_chld;
+        pid_t pid = 0;
+        int ret = EXIT_SUCCESS;
+        union in_addr_union exposed = {};
+        _cleanup_release_lock_file_ LockFile tree_global_lock = LOCK_FILE_INIT, tree_local_lock = LOCK_FILE_INIT;
+        bool interactive;
+
+        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);
+                                return r;
+                        }
+
+                        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,
+                                  &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 (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);
+
+        assert_se(sigemptyset(&mask_chld) == 0);
+        assert_se(sigaddset(&mask_chld, SIGCHLD) == 0);
+
+        if (prctl(PR_SET_CHILD_SUBREAPER, 1) < 0) {
+                r = log_error_errno(errno, "Failed to become subreaper: %m");
+                goto finish;
+        }
+
+        for (;;) {
+                _cleanup_close_pair_ int kmsg_socket_pair[2] = { -1, -1 }, rtnl_socket_pair[2] = { -1, -1 }, pid_socket_pair[2] = { -1, -1 }, uid_shift_socket_pair[2] = { -1, -1 };
+                ContainerStatus container_status;
+                _cleanup_(barrier_destroy) Barrier barrier = BARRIER_NULL;
+                static const struct sigaction sa = {
+                        .sa_handler = nop_signal_handler,
+                        .sa_flags = SA_NOCLDSTOP,
+                };
+                int ifi = 0;
+                ssize_t l;
+                _cleanup_(sd_event_unrefp) sd_event *event = NULL;
+                _cleanup_(pty_forward_freep) PTYForward *forward = NULL;
+                _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL;
+                char last_char = 0;
+
+                r = barrier_create(&barrier);
+                if (r < 0) {
+                        log_error_errno(r, "Cannot initialize IPC barrier: %m");
+                        goto finish;
+                }
+
+                if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, kmsg_socket_pair) < 0) {
+                        r = log_error_errno(errno, "Failed to create kmsg socket pair: %m");
+                        goto finish;
+                }
+
+                if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, rtnl_socket_pair) < 0) {
+                        r = log_error_errno(errno, "Failed to create rtnl socket pair: %m");
+                        goto finish;
+                }
+
+                if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, pid_socket_pair) < 0) {
+                        r = log_error_errno(errno, "Failed to create pid socket pair: %m");
+                        goto finish;
+                }
+
+                if (arg_userns)
+                        if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, uid_shift_socket_pair) < 0) {
+                                r = log_error_errno(errno, "Failed to create uid shift socket pair: %m");
+                                goto finish;
+                        }
+
+                /* 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) {
+                        r = log_error_errno(errno, "Failed to change the signal mask: %m");
+                        goto finish;
+                }
+
+                r = sigaction(SIGCHLD, &sa, NULL);
+                if (r < 0) {
+                        r = log_error_errno(errno, "Failed to install SIGCHLD handler: %m");
+                        goto finish;
+                }
+
+                pid = raw_clone(SIGCHLD|CLONE_NEWNS, NULL);
+                if (pid < 0) {
+                        if (errno == EINVAL)
+                                r = log_error_errno(errno, "clone() failed, do you have namespace support enabled in your kernel? (You need UTS, IPC, PID and NET namespacing built in): %m");
+                        else
+                                r = log_error_errno(errno, "clone() failed: %m");
+
+                        goto finish;
+                }
+
+                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]);
+                        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,
+                                        interactive,
+                                        secondary,
+                                        pid_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]);
+                uid_shift_socket_pair[1] = safe_close(uid_shift_socket_pair[1]);
+
+                /* Wait for the outer child. */
+                r = wait_for_terminate_and_warn("namespace helper", pid, NULL);
+                if (r < 0)
+                        goto finish;
+                if (r != 0) {
+                        r = -EIO;
+                        goto finish;
+                }
+                pid = 0;
+
+                /* And now retrieve the PID of the inner child. */
+                l = recv(pid_socket_pair[0], &pid, sizeof(pid), 0);
+                if (l < 0) {
+                        r = log_error_errno(errno, "Failed to read inner child PID: %m");
+                        goto finish;
+                }
+                if (l != sizeof(pid)) {
+                        log_error("Short read while reading inner child PID.");
+                        r = EIO;
+                        goto finish;
+                }
+
+                log_debug("Init process invoked as PID " PID_FMT, pid);
+
+                if (arg_userns) {
+                        if (!barrier_place_and_sync(&barrier)) { /* #1 */
+                                log_error("Child died too early.");
+                                r = -ESRCH;
+                                goto finish;
+                        }
+
+                        l = recv(uid_shift_socket_pair[0], &arg_uid_shift, sizeof(arg_uid_shift), 0);
+                        if (l < 0) {
+                                r = log_error_errno(errno, "Failed to read UID shift: %m");
+                                goto finish;
+                        }
+                        if (l != sizeof(arg_uid_shift)) {
+                                log_error("Short read while reading UID shift.");
+                                r = EIO;
+                                goto finish;
+                        }
+
+                        r = setup_uid_map(pid);
+                        if (r < 0)
+                                goto finish;
+
+                        (void) barrier_place(&barrier); /* #2 */
+                }
+
+                if (arg_private_network) {
+
+                        r = move_network_interfaces(pid, arg_network_interfaces);
+                        if (r < 0)
+                                goto finish;
+
+                        if (arg_network_veth) {
+                                r = setup_veth(arg_machine, pid, veth_name, !!arg_network_bridge);
+                                if (r < 0)
+                                        goto finish;
+                                else if (r > 0)
+                                        ifi = r;
+
+                                if (arg_network_bridge) {
+                                        r = setup_bridge(veth_name, arg_network_bridge);
+                                        if (r < 0)
+                                                goto finish;
+                                        if (r > 0)
+                                                ifi = r;
+                                }
+                        }
+
+                        r = setup_veth_extra(arg_machine, pid, arg_network_veth_extra);
+                        if (r < 0)
+                                goto finish;
+
+                        r = setup_macvlan(arg_machine, pid, arg_network_macvlan);
+                        if (r < 0)
+                                goto finish;
+
+                        r = setup_ipvlan(arg_machine, pid, arg_network_ipvlan);
+                        if (r < 0)
+                                goto finish;
+                }
+
+                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)
+                                goto finish;
+                }
+
+                r = sync_cgroup(pid, arg_unified_cgroup_hierarchy);
+                if (r < 0)
+                        goto finish;
+
+                if (arg_keep_unit) {
+                        r = create_subcgroup(pid, arg_unified_cgroup_hierarchy);
+                        if (r < 0)
+                                goto finish;
+                }
+
+                r = chown_cgroup(pid, arg_uid_shift);
+                if (r < 0)
+                        goto finish;
+
+                /* 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) {
+                        log_error_errno(r, "Failed to reset SIGCHLD: %m");
+                        goto finish;
+                }
+
+                /* 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.");
+                        r = -ESRCH;
+                        goto finish;
+                }
+
+                sd_notifyf(false,
+                           "READY=1\n"
+                           "STATUS=Container running.\n"
+                           "X_NSPAWN_LEADER_PID=" PID_FMT, pid);
+
+                r = sd_event_new(&event);
+                if (r < 0) {
+                        log_error_errno(r, "Failed to get default event source: %m");
+                        goto finish;
+                }
+
+                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)
+                                goto finish;
+
+                        (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) {
+                        log_error_errno(r, "Failed to create PTY forwarder: %m");
+                        goto finish;
+                }
+
+                r = sd_event_loop(event);
+                if (r < 0) {
+                        log_error_errno(r, "Failed to run event loop: %m");
+                        goto finish;
+                }
+
+                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 */
+                        goto finish;
+                else if (r > 0 || container_status == CONTAINER_TERMINATED){
+                        /* The container exited with a non-zero
+                         * status, or with zero status and no reboot
+                         * was requested. */
+                        ret = r;
+                        break;
+                }
+
+                /* 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 = 133;
+                        r = 0;
+                        break;
+                }
+
+                expose_port_flush(arg_expose_ports, &exposed);
+        }
+
+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);
+
+        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;
+}