nspawn: add new .nspawn files for container settings

.nspawn fiels are simple settings files that may accompany container
images and directories and contain settings otherwise passed on the
nspawn command line. This provides an efficient way to attach execution
data directly to containers.

12 files changed, 1086 insertions, 290 deletions

diff --git a/src/basic/conf-files.h b/src/basic/conf-files.h
index 3169a907f1..d8aebc5e5b 100644
--- a/src/basic/conf-files.h
+++ b/src/basic/conf-files.h
@@ -22,7 +22,6 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
-
-int conf_files_list(char ***strv, const char *suffix, const char *root, const char *dir, ...);
-int conf_files_list_strv(char ***strv, const char *suffix, const char *root, const char* const* dirs);
-int conf_files_list_nulstr(char ***strv, const char *suffix, const char *root, const char *dirs);
+int conf_files_list(char ***ret, const char *suffix, const char *root, const char *dir, ...);
+int conf_files_list_strv(char ***ret, const char *suffix, const char *root, const char* const* dirs);
+int conf_files_list_nulstr(char ***ret, const char *suffix, const char *root, const char *dirs);
diff --git a/src/core/load-fragment-gperf.gperf.m4 b/src/core/load-fragment-gperf.gperf.m4
index 60b97722db..edd55b9e45 100644
--- a/src/core/load-fragment-gperf.gperf.m4
+++ b/src/core/load-fragment-gperf.gperf.m4
@@ -106,7 +106,7 @@ m4_define(`KILL_CONTEXT_CONFIG_ITEMS',
 `$1.SendSIGKILL,                 config_parse_bool,                  0,                             offsetof($1, kill_context.send_sigkill)
 $1.SendSIGHUP,                   config_parse_bool,                  0,                             offsetof($1, kill_context.send_sighup)
 $1.KillMode,                     config_parse_kill_mode,             0,                             offsetof($1, kill_context.kill_mode)
-$1.KillSignal,                   config_parse_kill_signal,           0,                             offsetof($1, kill_context.kill_signal)'
+$1.KillSignal,                   config_parse_signal,                0,                             offsetof($1, kill_context.kill_signal)'
 )m4_dnl
 m4_define(`CGROUP_CONTEXT_CONFIG_ITEMS',
 `$1.Slice,                       config_parse_unit_slice,            0,                             0
diff --git a/src/core/load-fragment.c b/src/core/load-fragment.c
index c0db0dcefd..542bf8eb26 100644
--- a/src/core/load-fragment.c
+++ b/src/core/load-fragment.c
@@ -1143,39 +1143,8 @@ int config_parse_sysv_priority(const char *unit,
 #endif
 
 DEFINE_CONFIG_PARSE_ENUM(config_parse_exec_utmp_mode, exec_utmp_mode, ExecUtmpMode, "Failed to parse utmp mode");
-
 DEFINE_CONFIG_PARSE_ENUM(config_parse_kill_mode, kill_mode, KillMode, "Failed to parse kill mode");
 
-int config_parse_kill_signal(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 *sig = data;
-        int r;
-
-        assert(filename);
-        assert(lvalue);
-        assert(rvalue);
-        assert(sig);
-
-        r = signal_from_string_try_harder(rvalue);
-        if (r <= 0) {
-                log_syntax(unit, LOG_ERR, filename, line, -r,
-                           "Failed to parse kill signal, ignoring: %s", rvalue);
-                return 0;
-        }
-
-        *sig = r;
-        return 0;
-}
-
 int config_parse_exec_mount_flags(const char *unit,
                                   const char *filename,
                                   unsigned line,
@@ -3021,36 +2990,6 @@ int config_parse_job_mode_isolate(
         return 0;
 }
 
-int config_parse_personality(
-                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) {
-
-        unsigned long *personality = data, p;
-
-        assert(filename);
-        assert(lvalue);
-        assert(rvalue);
-        assert(personality);
-
-        p = personality_from_string(rvalue);
-        if (p == PERSONALITY_INVALID) {
-                log_syntax(unit, LOG_ERR, filename, line, EINVAL,
-                           "Failed to parse personality, ignoring: %s", rvalue);
-                return 0;
-        }
-
-        *personality = p;
-        return 0;
-}
-
 int config_parse_runtime_directory(
                 const char *unit,
                 const char *filename,
@@ -3720,7 +3659,7 @@ void unit_dump_config_items(FILE *f) {
                 { config_parse_sysv_priority,         "SYSVPRIORITY" },
 #endif
                 { config_parse_kill_mode,             "KILLMODE" },
-                { config_parse_kill_signal,           "SIGNAL" },
+                { config_parse_signal,                "SIGNAL" },
                 { config_parse_socket_listen,         "SOCKET [...]" },
                 { config_parse_socket_bind,           "SOCKETBIND" },
                 { config_parse_socket_bindtodevice,   "NETWORKINTERFACE" },
diff --git a/src/core/load-fragment.h b/src/core/load-fragment.h
index fcca2b0221..1d128716c4 100644
--- a/src/core/load-fragment.h
+++ b/src/core/load-fragment.h
@@ -92,7 +92,6 @@ int config_parse_blockio_bandwidth(const char *unit, const char *filename, unsig
 int config_parse_job_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_job_mode_isolate(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_exec_selinux_context(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_personality(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_exec_apparmor_profile(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_exec_smack_process_label(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_address_families(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/nspawn/.gitignore b/src/nspawn/.gitignore
new file mode 100644
index 0000000000..85c81fff24
--- /dev/null
+++ b/src/nspawn/.gitignore
@@ -0,0 +1 @@
+/nspawn-gperf.c
diff --git a/src/nspawn/nspawn-gperf.gperf b/src/nspawn/nspawn-gperf.gperf
new file mode 100644
index 0000000000..8b68dfa9f5
--- /dev/null
+++ b/src/nspawn/nspawn-gperf.gperf
@@ -0,0 +1,38 @@
+%{
+#include <stddef.h>
+#include "conf-parser.h"
+#include "nspawn.h"
+#include "nspawn-settings.h"
+%}
+struct ConfigPerfItem;
+%null_strings
+%language=ANSI-C
+%define slot-name section_and_lvalue
+%define hash-function-name nspawn_gperf_hash
+%define lookup-function-name nspawn_gperf_lookup
+%readonly-tables
+%omit-struct-type
+%struct-type
+%includes
+%%
+Exec.Boot,                 config_parse_tristate,      0, offsetof(Settings, boot)
+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)
+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.Bridge             config_parse_string,        0, offsetof(Settings, network_bridge)
+Network.Port,              config_parse_expose_port,   0, 0
diff --git a/src/nspawn/nspawn-settings.c b/src/nspawn/nspawn-settings.c
new file mode 100644
index 0000000000..9a403a3068
--- /dev/null
+++ b/src/nspawn/nspawn-settings.c
@@ -0,0 +1,263 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  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 "util.h"
+#include "conf-parser.h"
+#include "strv.h"
+#include "cap-list.h"
+
+#include "nspawn.h"
+#include "nspawn-settings.h"
+
+int settings_load(FILE *f, const char *path, Settings **ret) {
+        _cleanup_(settings_freep) Settings *s = NULL;
+        int r;
+
+        assert(path);
+        assert(ret);
+
+        s = new0(Settings, 1);
+        if (!s)
+                return -ENOMEM;
+
+        s->boot = -1;
+        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);
+
+        strv_free(s->network_interfaces);
+        strv_free(s->network_macvlan);
+        strv_free(s->network_ipvlan);
+        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;
+}
+
+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, cap, "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;
+        }
+
+        if (settings->network_bridge)
+                settings->network_veth = true;
+
+        if (settings->network_interfaces ||
+            settings->network_macvlan ||
+            settings->network_ipvlan ||
+            settings->network_bridge ||
+            settings->network_veth)
+                settings->private_network = true;
+
+        return 0;
+}
diff --git a/src/nspawn/nspawn-settings.h b/src/nspawn/nspawn-settings.h
new file mode 100644
index 0000000000..d9b3b2f7c0
--- /dev/null
+++ b/src/nspawn/nspawn-settings.h
@@ -0,0 +1,85 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+#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.h"
+
+typedef enum SettingsMask {
+        SETTING_BOOT          = 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,
+        _SETTINGS_MASK_ALL    = (1 << 12) -1
+} SettingsMask;
+
+typedef struct Settings {
+        /* [Run] */
+        int boot;
+        char **parameters;
+        char **environment;
+        char *user;
+        uint64_t capability;
+        uint64_t drop_capability;
+        int kill_signal;
+        unsigned long personality;
+        sd_id128_t machine_id;
+
+        /* [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;
+        ExposePort *expose_ports;
+} Settings;
+
+int settings_load(FILE *f, const char *path, Settings **ret);
+Settings* settings_free(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);
diff --git a/src/nspawn/nspawn.c b/src/nspawn/nspawn.c
index 1c64c3e771..a8afcd1466 100644
--- a/src/nspawn/nspawn.c
+++ b/src/nspawn/nspawn.c
@@ -102,12 +102,8 @@
 #include "seccomp-util.h"
 #endif
 
-typedef struct ExposePort {
-        int protocol;
-        uint16_t host_port;
-        uint16_t container_port;
-        LIST_FIELDS(struct ExposePort, ports);
-} ExposePort;
+#include "nspawn.h"
+#include "nspawn-settings.h"
 
 typedef enum ContainerStatus {
         CONTAINER_TERMINATED,
@@ -121,28 +117,6 @@ typedef enum LinkJournal {
         LINK_GUEST
 } LinkJournal;
 
-typedef enum Volatile {
-        VOLATILE_NO,
-        VOLATILE_YES,
-        VOLATILE_STATE,
-} Volatile;
-
-typedef enum CustomMountType {
-        CUSTOM_MOUNT_BIND,
-        CUSTOM_MOUNT_TMPFS,
-        CUSTOM_MOUNT_OVERLAY,
-} 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;
-
 static char *arg_directory = NULL;
 static char *arg_template = NULL;
 static char *arg_user = NULL;
@@ -195,16 +169,19 @@ 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 const char *arg_network_bridge = NULL;
+static char *arg_network_bridge = NULL;
 static unsigned long arg_personality = PERSONALITY_INVALID;
 static char *arg_image = NULL;
-static Volatile arg_volatile = VOLATILE_NO;
+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 void help(void) {
         printf("%s [OPTIONS...] [PATH] [ARGUMENTS...]\n\n"
@@ -275,30 +252,36 @@ static void help(void) {
                "     --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 CustomMount* custom_mount_add(CustomMountType t) {
+static CustomMount* custom_mount_add(CustomMount **l, unsigned *n, CustomMountType t) {
         CustomMount *c, *ret;
 
-        c = realloc(arg_custom_mounts, (arg_n_custom_mounts + 1) * sizeof(CustomMount));
+        assert(l);
+        assert(n);
+        assert(t >= 0);
+        assert(t < _CUSTOM_MOUNT_TYPE_MAX);
+
+        c = realloc(*l, (*n + 1) * sizeof(CustomMount));
         if (!c)
                 return NULL;
 
-        arg_custom_mounts = c;
-        ret = arg_custom_mounts + arg_n_custom_mounts;
-        arg_n_custom_mounts++;
+        *l = c;
+        ret = *l + *n;
+        (*n)++;
 
         *ret = (CustomMount) { .type = t };
 
         return ret;
 }
 
-static void custom_mount_free_all(void) {
+void custom_mount_free_all(CustomMount *l, unsigned n) {
         unsigned i;
 
-        for (i = 0; i < arg_n_custom_mounts; i++) {
-                CustomMount *m = &arg_custom_mounts[i];
+        for (i = 0; i < n; i++) {
+                CustomMount *m = l + i;
 
                 free(m->source);
                 free(m->destination);
@@ -312,8 +295,7 @@ static void custom_mount_free_all(void) {
                 strv_free(m->lower);
         }
 
-        arg_custom_mounts = mfree(arg_custom_mounts);
-        arg_n_custom_mounts = 0;
+        free(l);
 }
 
 static int custom_mount_compare(const void *a, const void *b) {
@@ -410,6 +392,161 @@ static int detect_unified_cgroup_hierarchy(void) {
         return 0;
 }
 
+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;
+}
+
+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;
+
+        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, arg_expose_ports)
+                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;
+}
+
+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 parse_argv(int argc, char *argv[]) {
 
         enum {
@@ -439,6 +576,7 @@ static int parse_argv(int argc, char *argv[]) {
                 ARG_PROPERTY,
                 ARG_PRIVATE_USERS,
                 ARG_KILL_SIGNAL,
+                ARG_SETTINGS,
         };
 
         static const struct option options[] = {
@@ -481,11 +619,13 @@ static int parse_argv(int argc, char *argv[]) {
                 { "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          },
                 {}
         };
 
         int c, r;
         uint64_t plus = 0, minus = 0;
+        bool mask_all_settings = false, mask_no_settings = false;
 
         assert(argc >= 0);
         assert(argv);
@@ -533,16 +673,20 @@ static int parse_argv(int argc, char *argv[]) {
                         if (r < 0)
                                 return log_oom();
 
+                        arg_settings_mask |= SETTING_USER;
                         break;
 
                 case ARG_NETWORK_BRIDGE:
-                        arg_network_bridge = optarg;
+                        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_INTERFACE:
@@ -550,6 +694,7 @@ static int parse_argv(int argc, char *argv[]) {
                                 return log_oom();
 
                         arg_private_network = true;
+                        arg_settings_mask |= SETTING_NETWORK;
                         break;
 
                 case ARG_NETWORK_MACVLAN:
@@ -557,6 +702,7 @@ static int parse_argv(int argc, char *argv[]) {
                                 return log_oom();
 
                         arg_private_network = true;
+                        arg_settings_mask |= SETTING_NETWORK;
                         break;
 
                 case ARG_NETWORK_IPVLAN:
@@ -567,10 +713,12 @@ static int parse_argv(int argc, char *argv[]) {
 
                 case ARG_PRIVATE_NETWORK:
                         arg_private_network = true;
+                        arg_settings_mask |= SETTING_NETWORK;
                         break;
 
                 case 'b':
                         arg_boot = true;
+                        arg_settings_mask |= SETTING_BOOT;
                         break;
 
                 case ARG_UUID:
@@ -579,6 +727,8 @@ static int parse_argv(int argc, char *argv[]) {
                                 log_error("Invalid UUID: %s", optarg);
                                 return r;
                         }
+
+                        arg_settings_mask |= SETTING_MACHINE_ID;
                         break;
 
                 case 'S':
@@ -611,6 +761,7 @@ static int parse_argv(int argc, char *argv[]) {
 
                 case ARG_READ_ONLY:
                         arg_read_only = true;
+                        arg_settings_mask |= SETTING_READ_ONLY;
                         break;
 
                 case ARG_CAPABILITY:
@@ -646,6 +797,7 @@ static int parse_argv(int argc, char *argv[]) {
                                 }
                         }
 
+                        arg_settings_mask |= SETTING_CAPABILITY;
                         break;
                 }
 
@@ -681,83 +833,21 @@ static int parse_argv(int argc, char *argv[]) {
                         break;
 
                 case ARG_BIND:
-                case ARG_BIND_RO: {
-                        const char *current = optarg;
-                        _cleanup_free_ char *source = NULL, *destination = NULL, *opts = NULL;
-                        CustomMount *m;
-
-                        r = extract_many_words(&current, ":", EXTRACT_DONT_COALESCE_SEPARATORS, &source, &destination, &opts, NULL);
-                        switch (r) {
-                        case 1:
-                                destination = strdup(source);
-                        case 2:
-                        case 3:
-                                break;
-                        case -ENOMEM:
-                                return log_oom();
-                        default:
-                                log_error("Invalid bind mount specification: %s", optarg);
-                                return -EINVAL;
-                        }
-
-                        if (!source || !destination)
-                                return log_oom();
-
-                        if (!path_is_absolute(source) || !path_is_absolute(destination)) {
-                                log_error("Invalid bind mount specification: %s", optarg);
-                                return -EINVAL;
-                        }
-
-                        m = custom_mount_add(CUSTOM_MOUNT_BIND);
-                        if (!m)
-                                return log_oom();
-
-                        m->source = source;
-                        m->destination = destination;
-                        m->read_only = c == ARG_BIND_RO;
-                        m->options = opts;
-
-                        source = destination = opts = NULL;
+                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: {
-                        const char *current = optarg;
-                        _cleanup_free_ char *path = NULL, *opts = NULL;
-                        CustomMount *m;
-
-                        r = extract_first_word(&current, &path, ":", EXTRACT_DONT_COALESCE_SEPARATORS);
-                        if (r == -ENOMEM)
-                                return log_oom();
-                        else if (r < 0) {
-                                log_error("Invalid tmpfs specification: %s", optarg);
-                                return r;
-                        }
-                        if (r)
-                                opts = strdup(current);
-                        else
-                                opts = strdup("mode=0755");
-
-                        if (!path || !opts)
-                                return log_oom();
-
-                        if (!path_is_absolute(path)) {
-                                log_error("Invalid tmpfs specification: %s", optarg);
-                                return -EINVAL;
-                        }
-
-                        m = custom_mount_add(CUSTOM_MOUNT_TMPFS);
-                        if (!m)
-                                return log_oom();
-
-                        m->destination = path;
-                        m->options = opts;
 
-                        path = opts = NULL;
+                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: {
@@ -808,7 +898,7 @@ static int parse_argv(int argc, char *argv[]) {
                                 lower[n - 2] = NULL;
                         }
 
-                        m = custom_mount_add(CUSTOM_MOUNT_OVERLAY);
+                        m = custom_mount_add(&arg_custom_mounts, &arg_n_custom_mounts, CUSTOM_MOUNT_OVERLAY);
                         if (!m)
                                 return log_oom();
 
@@ -820,6 +910,7 @@ static int parse_argv(int argc, char *argv[]) {
                         upper = destination = NULL;
                         lower = NULL;
 
+                        arg_settings_mask |= SETTING_CUSTOM_MOUNTS;
                         break;
                 }
 
@@ -837,6 +928,8 @@ static int parse_argv(int argc, char *argv[]) {
 
                         strv_free(arg_setenv);
                         arg_setenv = n;
+
+                        arg_settings_mask |= SETTING_ENVIRONMENT;
                         break;
                 }
 
@@ -870,85 +963,36 @@ static int parse_argv(int argc, char *argv[]) {
                                 return -EINVAL;
                         }
 
+                        arg_settings_mask |= SETTING_PERSONALITY;
                         break;
 
                 case ARG_VOLATILE:
 
                         if (!optarg)
-                                arg_volatile = VOLATILE_YES;
+                                arg_volatile_mode = VOLATILE_YES;
                         else {
-                                r = parse_boolean(optarg);
-                                if (r < 0) {
-                                        if (streq(optarg, "state"))
-                                                arg_volatile = VOLATILE_STATE;
-                                        else {
-                                                log_error("Failed to parse --volatile= argument: %s", optarg);
-                                                return r;
-                                        }
-                                } else
-                                        arg_volatile = r ? VOLATILE_YES : VOLATILE_NO;
-                        }
+                                VolatileMode m;
 
-                        break;
-
-                case 'p': {
-                        const char *split, *e;
-                        uint16_t container_port, host_port;
-                        int protocol;
-                        ExposePort *p;
-
-                        if ((e = startswith(optarg, "tcp:")))
-                                protocol = IPPROTO_TCP;
-                        else if ((e = startswith(optarg, "udp:")))
-                                protocol = IPPROTO_UDP;
-                        else {
-                                e = optarg;
-                                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) {
-                                        log_error("Failed to parse host port: %s", optarg);
-                                        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) {
-                                log_error("Failed to parse host port: %s", optarg);
-                                return -EINVAL;
-                        }
-
-                        LIST_FOREACH(ports, p, arg_expose_ports) {
-                                if (p->protocol == protocol && p->host_port == host_port) {
-                                        log_error("Duplicate port specification: %s", optarg);
+                                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;
                         }
 
-                        p = new(ExposePort, 1);
-                        if (!p)
-                                return log_oom();
-
-                        p->protocol = protocol;
-                        p->host_port = host_port;
-                        p->container_port = container_port;
+                        arg_settings_mask |= SETTING_VOLATILE_MODE;
+                        break;
 
-                        LIST_PREPEND(ports, arg_expose_ports, p);
+                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)
@@ -992,6 +1036,42 @@ static int parse_argv(int argc, char *argv[]) {
                                 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 '?':
@@ -1044,7 +1124,37 @@ static int parse_argv(int argc, char *argv[]) {
                 return -EINVAL;
         }
 
-        if (arg_volatile != VOLATILE_NO && arg_read_only) {
+        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_BOOT;
+        }
+
+        /* 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;
+
+        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;
         }
@@ -1054,19 +1164,10 @@ static int parse_argv(int argc, char *argv[]) {
                 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.");
-
-        arg_retain = (arg_retain | plus | (arg_private_network ? 1ULL << CAP_NET_ADMIN : 0)) & ~minus;
-
         if (arg_boot && arg_kill_signal <= 0)
                 arg_kill_signal = SIGRTMIN+3;
 
-        r = detect_unified_cgroup_hierarchy();
-        if (r < 0)
-                return r;
-
-        return 1;
+        return 0;
 }
 
 static int tmpfs_patch_options(const char *options, char **ret) {
@@ -1743,7 +1844,7 @@ static int setup_volatile_state(const char *directory) {
 
         assert(directory);
 
-        if (arg_volatile != VOLATILE_STATE)
+        if (arg_volatile_mode != VOLATILE_STATE)
                 return 0;
 
         /* --volatile=state means we simply overmount /var
@@ -1780,7 +1881,7 @@ static int setup_volatile(const char *directory) {
 
         assert(directory);
 
-        if (arg_volatile != VOLATILE_YES)
+        if (arg_volatile_mode != VOLATILE_YES)
                 return 0;
 
         /* --volatile=yes means we mount a tmpfs to the root dir, and
@@ -2208,6 +2309,15 @@ static int expose_ports(sd_netlink *rtnl, union in_addr_union *exposed) {
         return 0;
 }
 
+void expose_port_free_all(ExposePort *p) {
+
+        while (p) {
+                ExposePort *q = p;
+                LIST_REMOVE(ports, p, q);
+                free(q);
+        }
+}
+
 static int on_address_change(sd_netlink *rtnl, sd_netlink_message *m, void *userdata) {
         union in_addr_union *exposed = userdata;
 
@@ -4254,9 +4364,7 @@ static int inner_child(
                 bool secondary,
                 int kmsg_socket,
                 int rtnl_socket,
-                FDSet *fds,
-                int argc,
-                char *argv[]) {
+                FDSet *fds) {
 
         _cleanup_free_ char *home = NULL;
         unsigned n_env = 2;
@@ -4412,9 +4520,12 @@ static int inner_child(
 
                 /* Automatically search for the init system */
 
-                m = 1 + argc - optind;
+                m = 1 + strv_length(arg_parameters);
                 a = newa(char*, m + 1);
-                memcpy(a + 1, argv + optind, m * sizeof(char*));
+                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);
@@ -4424,10 +4535,10 @@ static int inner_child(
 
                 a[0] = (char*) "/sbin/init";
                 execve(a[0], a, env_use);
-        } else if (argc > optind)
-                execvpe(argv[optind], argv + optind, env_use);
+        } else if (!strv_isempty(arg_parameters))
+                execvpe(arg_parameters[0], arg_parameters, env_use);
         else {
-                chdir(home ? home : "/root");
+                chdir(home ?: "/root");
                 execle("/bin/bash", "-bash", NULL, env_use);
                 execle("/bin/sh", "-sh", NULL, env_use);
         }
@@ -4449,9 +4560,7 @@ static int outer_child(
                 int kmsg_socket,
                 int rtnl_socket,
                 int uid_shift_socket,
-                FDSet *fds,
-                int argc,
-                char *argv[]) {
+                FDSet *fds) {
 
         pid_t pid;
         ssize_t l;
@@ -4604,7 +4713,7 @@ static int outer_child(
                  * 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, argc, argv);
+                r = inner_child(barrier, directory, secondary, kmsg_socket, rtnl_socket, fds);
                 if (r < 0)
                         _exit(EXIT_FAILURE);
 
@@ -4780,6 +4889,202 @@ static int create_subcgroup(pid_t pid) {
         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_BOOT) == 0 &&
+            settings->boot >= 0) {
+                arg_boot = settings->boot;
+
+                strv_free(arg_parameters);
+                arg_parameters = settings->parameters;
+                settings->parameters = 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) {
+
+                if (!arg_settings_trusted && settings->capability != 0)
+                        log_warning("Ignoring Capability= setting, file %s is not trusted.", p);
+                else
+                        arg_retain |= settings->capability;
+
+                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)) {
+
+                if (!arg_settings_trusted)
+                        log_warning("Ignoring network settings, file %s is not trusted.", p);
+                else {
+                        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;
+
+                        free(arg_network_bridge);
+                        arg_network_bridge = settings->network_bridge;
+                        settings->network_bridge = NULL;
+
+                        arg_network_veth = settings->network_veth > 0 || settings->network_bridge;
+
+                        arg_private_network = true; /* all these settings imply private networking */
+                }
+        }
+
+        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;
@@ -4803,15 +5108,22 @@ int main(int argc, char *argv[]) {
         if (r <= 0)
                 goto finish;
 
-        r = determine_names();
-        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) {
@@ -5092,8 +5404,7 @@ int main(int argc, char *argv[]) {
                                         kmsg_socket_pair[1],
                                         rtnl_socket_pair[1],
                                         uid_shift_socket_pair[1],
-                                        fds,
-                                        argc, argv);
+                                        fds);
                         if (r < 0)
                                 _exit(EXIT_FAILURE);
 
@@ -5342,24 +5653,21 @@ finish:
                 (void) rm_rf(p, REMOVE_ROOT);
         }
 
+        flush_ports(&exposed);
+
         free(arg_directory);
         free(arg_template);
         free(arg_image);
         free(arg_machine);
         free(arg_user);
         strv_free(arg_setenv);
+        free(arg_network_bridge);
         strv_free(arg_network_interfaces);
         strv_free(arg_network_macvlan);
         strv_free(arg_network_ipvlan);
-        custom_mount_free_all();
-
-        flush_ports(&exposed);
-
-        while (arg_expose_ports) {
-                ExposePort *p = arg_expose_ports;
-                LIST_REMOVE(ports, arg_expose_ports, p);
-                free(p);
-        }
+        strv_free(arg_parameters);
+        custom_mount_free_all(arg_custom_mounts, arg_n_custom_mounts);
+        expose_port_free_all(arg_expose_ports);
 
         return r < 0 ? EXIT_FAILURE : ret;
 }
diff --git a/src/nspawn/nspawn.h b/src/nspawn/nspawn.h
new file mode 100644
index 0000000000..2124b434fe
--- /dev/null
+++ b/src/nspawn/nspawn.h
@@ -0,0 +1,69 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+#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 <stdbool.h>
+
+#include "list.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;
+
+typedef struct ExposePort {
+        int protocol;
+        uint16_t host_port;
+        uint16_t container_port;
+        LIST_FIELDS(struct ExposePort, ports);
+} ExposePort;
+
+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);
+
+void expose_port_free_all(ExposePort *p);
+int expose_port_parse(ExposePort **l, const char *s);
+
+VolatileMode volatile_mode_from_string(const char *s);
diff --git a/src/shared/conf-parser.c b/src/shared/conf-parser.c
index 1f4aea6d6b..36150d8744 100644
--- a/src/shared/conf-parser.c
+++ b/src/shared/conf-parser.c
@@ -24,7 +24,7 @@
 #include <errno.h>
 #include <stdlib.h>
 
-#include "conf-parser.h"
+#include "sd-messages.h"
 #include "conf-files.h"
 #include "util.h"
 #include "macro.h"
@@ -32,7 +32,8 @@
 #include "log.h"
 #include "utf8.h"
 #include "path-util.h"
-#include "sd-messages.h"
+#include "signal-util.h"
+#include "conf-parser.h"
 
 int config_item_table_lookup(
                 const void *table,
@@ -575,6 +576,39 @@ int config_parse_bool(const char* unit,
         return 0;
 }
 
+int config_parse_tristate(
+                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 k, *t = data;
+
+        assert(filename);
+        assert(lvalue);
+        assert(rvalue);
+        assert(data);
+
+        /* A tristate is pretty much a boolean, except that it can
+         * also take the special value -1, indicating "uninitialized",
+         * much like NULL is for a pointer type. */
+
+        k = parse_boolean(rvalue);
+        if (k < 0) {
+                log_syntax(unit, LOG_ERR, filename, line, k, "Failed to parse boolean value, ignoring: %s", rvalue);
+                return 0;
+        }
+
+        *t = !!k;
+        return 0;
+}
+
 int config_parse_string(
                 const char *unit,
                 const char *filename,
@@ -802,3 +836,61 @@ int config_parse_log_level(
         *o = (*o & LOG_FACMASK) | x;
         return 0;
 }
+
+int config_parse_signal(
+                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 *sig = data, r;
+
+        assert(filename);
+        assert(lvalue);
+        assert(rvalue);
+        assert(sig);
+
+        r = signal_from_string_try_harder(rvalue);
+        if (r <= 0) {
+                log_syntax(unit, LOG_ERR, filename, line, EINVAL, "Failed to parse signal name, ignoring: %s", rvalue);
+                return 0;
+        }
+
+        *sig = r;
+        return 0;
+}
+
+int config_parse_personality(
+                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) {
+
+        unsigned long *personality = data, p;
+
+        assert(filename);
+        assert(lvalue);
+        assert(rvalue);
+        assert(personality);
+
+        p = personality_from_string(rvalue);
+        if (p == PERSONALITY_INVALID) {
+                log_syntax(unit, LOG_ERR, filename, line, EINVAL, "Failed to parse personality, ignoring: %s", rvalue);
+                return 0;
+        }
+
+        *personality = p;
+        return 0;
+}
diff --git a/src/shared/conf-parser.h b/src/shared/conf-parser.h
index 66c80890d3..34e3815782 100644
--- a/src/shared/conf-parser.h
+++ b/src/shared/conf-parser.h
@@ -111,6 +111,7 @@ int config_parse_iec_size(const char *unit, const char *filename, unsigned line,
 int config_parse_si_size(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_iec_off(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_bool(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_tristate(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_string(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_path(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_strv(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);
@@ -119,6 +120,8 @@ int config_parse_nsec(const char *unit, const char *filename, unsigned line, con
 int config_parse_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_log_facility(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_log_level(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_signal(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_personality(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);
 
 #define log_invalid_utf8(unit, level, config_file, config_line, error, rvalue) \
         do {                                                            \