Adding upstream version 247.3.upstream/247.3upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 5561 insertions, 0 deletions

diff --git a/src/nspawn/nspawn.c b/src/nspawn/nspawn.c
new file mode 100644
index 0000000..7515380
--- /dev/null
+++ b/src/nspawn/nspawn.c
@@ -0,0 +1,5561 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#if HAVE_BLKID
+#endif
+#include <errno.h>
+#include <getopt.h>
+#include <linux/fs.h>
+#include <linux/loop.h>
+#if HAVE_SELINUX
+#include <selinux/selinux.h>
+#endif
+#include <stdlib.h>
+#include <sys/file.h>
+#include <sys/ioctl.h>
+#include <sys/personality.h>
+#include <sys/prctl.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <termios.h>
+#include <unistd.h>
+
+#include "sd-bus.h"
+#include "sd-daemon.h"
+#include "sd-id128.h"
+
+#include "alloc-util.h"
+#include "barrier.h"
+#include "base-filesystem.h"
+#include "blkid-util.h"
+#include "btrfs-util.h"
+#include "bus-error.h"
+#include "bus-util.h"
+#include "cap-list.h"
+#include "capability-util.h"
+#include "cgroup-util.h"
+#include "copy.h"
+#include "cpu-set-util.h"
+#include "dev-setup.h"
+#include "dissect-image.h"
+#include "env-util.h"
+#include "escape.h"
+#include "fd-util.h"
+#include "fdset.h"
+#include "fileio.h"
+#include "format-util.h"
+#include "fs-util.h"
+#include "gpt.h"
+#include "hexdecoct.h"
+#include "hostname-util.h"
+#include "id128-util.h"
+#include "io-util.h"
+#include "log.h"
+#include "loop-util.h"
+#include "loopback-setup.h"
+#include "machine-image.h"
+#include "macro.h"
+#include "main-func.h"
+#include "missing_sched.h"
+#include "mkdir.h"
+#include "mount-util.h"
+#include "mountpoint-util.h"
+#include "namespace-util.h"
+#include "netlink-util.h"
+#include "nspawn-cgroup.h"
+#include "nspawn-creds.h"
+#include "nspawn-def.h"
+#include "nspawn-expose-ports.h"
+#include "nspawn-mount.h"
+#include "nspawn-network.h"
+#include "nspawn-oci.h"
+#include "nspawn-patch-uid.h"
+#include "nspawn-register.h"
+#include "nspawn-seccomp.h"
+#include "nspawn-settings.h"
+#include "nspawn-setuid.h"
+#include "nspawn-stub-pid1.h"
+#include "nulstr-util.h"
+#include "os-util.h"
+#include "pager.h"
+#include "parse-util.h"
+#include "path-util.h"
+#include "pretty-print.h"
+#include "process-util.h"
+#include "ptyfwd.h"
+#include "random-util.h"
+#include "raw-clone.h"
+#include "resolve-util.h"
+#include "rlimit-util.h"
+#include "rm-rf.h"
+#if HAVE_SECCOMP
+#include "seccomp-util.h"
+#endif
+#include "selinux-util.h"
+#include "signal-util.h"
+#include "socket-util.h"
+#include "stat-util.h"
+#include "stdio-util.h"
+#include "string-table.h"
+#include "string-util.h"
+#include "strv.h"
+#include "sysctl-util.h"
+#include "terminal-util.h"
+#include "tmpfile-util.h"
+#include "umask-util.h"
+#include "unit-name.h"
+#include "user-util.h"
+#include "util.h"
+
+/* The notify socket inside the container it can use to talk to nspawn using the sd_notify(3) protocol */
+#define NSPAWN_NOTIFY_SOCKET_PATH "/run/host/notify"
+
+#define EXIT_FORCE_RESTART 133
+
+typedef enum ContainerStatus {
+        CONTAINER_TERMINATED,
+        CONTAINER_REBOOTED,
+} ContainerStatus;
+
+static char *arg_directory = NULL;
+static char *arg_template = NULL;
+static char *arg_chdir = NULL;
+static char *arg_pivot_root_new = NULL;
+static char *arg_pivot_root_old = NULL;
+static char *arg_user = NULL;
+static uid_t arg_uid = UID_INVALID;
+static gid_t arg_gid = GID_INVALID;
+static gid_t* arg_supplementary_gids = NULL;
+static size_t arg_n_supplementary_gids = 0;
+static sd_id128_t arg_uuid = {};
+static char *arg_machine = NULL;     /* The name used by the host to refer to this */
+static char *arg_hostname = NULL;    /* The name the payload sees by default */
+static const char *arg_selinux_context = NULL;
+static const char *arg_selinux_apifs_context = NULL;
+static char *arg_slice = NULL;
+static bool arg_private_network = false;
+static bool arg_read_only = false;
+static StartMode arg_start_mode = START_PID1;
+static bool arg_ephemeral = false;
+static LinkJournal arg_link_journal = LINK_AUTO;
+static bool arg_link_journal_try = false;
+static uint64_t arg_caps_retain =
+        (1ULL << CAP_AUDIT_CONTROL) |
+        (1ULL << CAP_AUDIT_WRITE) |
+        (1ULL << CAP_CHOWN) |
+        (1ULL << CAP_DAC_OVERRIDE) |
+        (1ULL << CAP_DAC_READ_SEARCH) |
+        (1ULL << CAP_FOWNER) |
+        (1ULL << CAP_FSETID) |
+        (1ULL << CAP_IPC_OWNER) |
+        (1ULL << CAP_KILL) |
+        (1ULL << CAP_LEASE) |
+        (1ULL << CAP_LINUX_IMMUTABLE) |
+        (1ULL << CAP_MKNOD) |
+        (1ULL << CAP_NET_BIND_SERVICE) |
+        (1ULL << CAP_NET_BROADCAST) |
+        (1ULL << CAP_NET_RAW) |
+        (1ULL << CAP_SETFCAP) |
+        (1ULL << CAP_SETGID) |
+        (1ULL << CAP_SETPCAP) |
+        (1ULL << CAP_SETUID) |
+        (1ULL << CAP_SYS_ADMIN) |
+        (1ULL << CAP_SYS_BOOT) |
+        (1ULL << CAP_SYS_CHROOT) |
+        (1ULL << CAP_SYS_NICE) |
+        (1ULL << CAP_SYS_PTRACE) |
+        (1ULL << CAP_SYS_RESOURCE) |
+        (1ULL << CAP_SYS_TTY_CONFIG);
+static CapabilityQuintet arg_full_capabilities = CAPABILITY_QUINTET_NULL;
+static CustomMount *arg_custom_mounts = NULL;
+static size_t arg_n_custom_mounts = 0;
+static char **arg_setenv = NULL;
+static bool arg_quiet = false;
+static bool arg_register = true;
+static bool arg_keep_unit = false;
+static char **arg_network_interfaces = NULL;
+static char **arg_network_macvlan = NULL;
+static char **arg_network_ipvlan = NULL;
+static bool arg_network_veth = false;
+static char **arg_network_veth_extra = NULL;
+static char *arg_network_bridge = NULL;
+static char *arg_network_zone = NULL;
+static char *arg_network_namespace_path = NULL;
+static PagerFlags arg_pager_flags = 0;
+static unsigned long arg_personality = PERSONALITY_INVALID;
+static char *arg_image = NULL;
+static char *arg_oci_bundle = NULL;
+static VolatileMode arg_volatile_mode = VOLATILE_NO;
+static ExposePort *arg_expose_ports = NULL;
+static char **arg_property = NULL;
+static sd_bus_message *arg_property_message = NULL;
+static UserNamespaceMode arg_userns_mode = USER_NAMESPACE_NO;
+static uid_t arg_uid_shift = UID_INVALID, arg_uid_range = 0x10000U;
+static bool arg_userns_chown = false;
+static int arg_kill_signal = 0;
+static CGroupUnified arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_UNKNOWN;
+static SettingsMask arg_settings_mask = 0;
+static int arg_settings_trusted = -1;
+static char **arg_parameters = NULL;
+static const char *arg_container_service_name = "systemd-nspawn";
+static bool arg_notify_ready = false;
+static bool arg_use_cgns = true;
+static unsigned long arg_clone_ns_flags = CLONE_NEWIPC|CLONE_NEWPID|CLONE_NEWUTS;
+static MountSettingsMask arg_mount_settings = MOUNT_APPLY_APIVFS_RO|MOUNT_APPLY_TMPFS_TMP;
+static VeritySettings arg_verity_settings = VERITY_SETTINGS_DEFAULT;
+static char **arg_syscall_allow_list = NULL;
+static char **arg_syscall_deny_list = NULL;
+#if HAVE_SECCOMP
+static scmp_filter_ctx arg_seccomp = NULL;
+#endif
+static struct rlimit *arg_rlimit[_RLIMIT_MAX] = {};
+static bool arg_no_new_privileges = false;
+static int arg_oom_score_adjust = 0;
+static bool arg_oom_score_adjust_set = false;
+static CPUSet arg_cpu_set = {};
+static ResolvConfMode arg_resolv_conf = RESOLV_CONF_AUTO;
+static TimezoneMode arg_timezone = TIMEZONE_AUTO;
+static unsigned arg_console_width = (unsigned) -1, arg_console_height = (unsigned) -1;
+static DeviceNode* arg_extra_nodes = NULL;
+static size_t arg_n_extra_nodes = 0;
+static char **arg_sysctl = NULL;
+static ConsoleMode arg_console_mode = _CONSOLE_MODE_INVALID;
+static Credential *arg_credentials = NULL;
+static size_t arg_n_credentials = 0;
+
+STATIC_DESTRUCTOR_REGISTER(arg_directory, freep);
+STATIC_DESTRUCTOR_REGISTER(arg_template, freep);
+STATIC_DESTRUCTOR_REGISTER(arg_chdir, freep);
+STATIC_DESTRUCTOR_REGISTER(arg_pivot_root_new, freep);
+STATIC_DESTRUCTOR_REGISTER(arg_pivot_root_old, freep);
+STATIC_DESTRUCTOR_REGISTER(arg_user, freep);
+STATIC_DESTRUCTOR_REGISTER(arg_supplementary_gids, freep);
+STATIC_DESTRUCTOR_REGISTER(arg_machine, freep);
+STATIC_DESTRUCTOR_REGISTER(arg_hostname, freep);
+STATIC_DESTRUCTOR_REGISTER(arg_slice, freep);
+STATIC_DESTRUCTOR_REGISTER(arg_setenv, strv_freep);
+STATIC_DESTRUCTOR_REGISTER(arg_network_interfaces, strv_freep);
+STATIC_DESTRUCTOR_REGISTER(arg_network_macvlan, strv_freep);
+STATIC_DESTRUCTOR_REGISTER(arg_network_ipvlan, strv_freep);
+STATIC_DESTRUCTOR_REGISTER(arg_network_veth_extra, strv_freep);
+STATIC_DESTRUCTOR_REGISTER(arg_network_bridge, freep);
+STATIC_DESTRUCTOR_REGISTER(arg_network_zone, freep);
+STATIC_DESTRUCTOR_REGISTER(arg_network_namespace_path, freep);
+STATIC_DESTRUCTOR_REGISTER(arg_image, freep);
+STATIC_DESTRUCTOR_REGISTER(arg_oci_bundle, freep);
+STATIC_DESTRUCTOR_REGISTER(arg_property, strv_freep);
+STATIC_DESTRUCTOR_REGISTER(arg_property_message, sd_bus_message_unrefp);
+STATIC_DESTRUCTOR_REGISTER(arg_parameters, strv_freep);
+STATIC_DESTRUCTOR_REGISTER(arg_verity_settings, verity_settings_done);
+STATIC_DESTRUCTOR_REGISTER(arg_syscall_allow_list, strv_freep);
+STATIC_DESTRUCTOR_REGISTER(arg_syscall_deny_list, strv_freep);
+#if HAVE_SECCOMP
+STATIC_DESTRUCTOR_REGISTER(arg_seccomp, seccomp_releasep);
+#endif
+STATIC_DESTRUCTOR_REGISTER(arg_cpu_set, cpu_set_reset);
+STATIC_DESTRUCTOR_REGISTER(arg_sysctl, strv_freep);
+
+static int handle_arg_console(const char *arg) {
+        if (streq(arg, "help")) {
+                puts("autopipe\n"
+                     "interactive\n"
+                     "passive\n"
+                     "pipe\n"
+                     "read-only");
+                return 0;
+        }
+
+        if (streq(arg, "interactive"))
+                arg_console_mode = CONSOLE_INTERACTIVE;
+        else if (streq(arg, "read-only"))
+                arg_console_mode = CONSOLE_READ_ONLY;
+        else if (streq(arg, "passive"))
+                arg_console_mode = CONSOLE_PASSIVE;
+        else if (streq(arg, "pipe")) {
+                if (isatty(STDIN_FILENO) > 0 && isatty(STDOUT_FILENO) > 0)
+                        log_full(arg_quiet ? LOG_DEBUG : LOG_NOTICE,
+                                 "Console mode 'pipe' selected, but standard input/output are connected to an interactive TTY. "
+                                 "Most likely you want to use 'interactive' console mode for proper interactivity and shell job control. "
+                                 "Proceeding anyway.");
+
+                arg_console_mode = CONSOLE_PIPE;
+        } else if (streq(arg, "autopipe")) {
+                if (isatty(STDIN_FILENO) > 0 && isatty(STDOUT_FILENO) > 0)
+                        arg_console_mode = CONSOLE_INTERACTIVE;
+                else
+                        arg_console_mode = CONSOLE_PIPE;
+        } else
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Unknown console mode: %s", optarg);
+
+        arg_settings_mask |= SETTING_CONSOLE_MODE;
+        return 1;
+}
+
+static int help(void) {
+        _cleanup_free_ char *link = NULL;
+        int r;
+
+        (void) pager_open(arg_pager_flags);
+
+        r = terminal_urlify_man("systemd-nspawn", "1", &link);
+        if (r < 0)
+                return log_oom();
+
+        printf("%1$s [OPTIONS...] [PATH] [ARGUMENTS...]\n\n"
+               "%5$sSpawn a command or OS in a light-weight container.%6$s\n\n"
+               "  -h --help                 Show this help\n"
+               "     --version              Print version string\n"
+               "  -q --quiet                Do not show status information\n"
+               "     --no-pager             Do not pipe output into a pager\n"
+               "     --settings=BOOLEAN     Load additional settings from .nspawn file\n\n"
+               "%3$sImage:%4$s\n"
+               "  -D --directory=PATH       Root directory for the container\n"
+               "     --template=PATH        Initialize root directory from template directory,\n"
+               "                            if missing\n"
+               "  -x --ephemeral            Run container with snapshot of root directory, and\n"
+               "                            remove it after exit\n"
+               "  -i --image=PATH           Root file system disk image (or device node) for\n"
+               "                            the container\n"
+               "     --oci-bundle=PATH      OCI bundle directory\n"
+               "     --read-only            Mount the root directory read-only\n"
+               "     --volatile[=MODE]      Run the system in volatile mode\n"
+               "     --root-hash=HASH       Specify verity root hash for root disk image\n"
+               "     --root-hash-sig=SIG    Specify pkcs7 signature of root hash for verity\n"
+               "                            as a DER encoded PKCS7, either as a path to a file\n"
+               "                            or as an ASCII base64 encoded string prefixed by\n"
+               "                            'base64:'\n"
+               "     --verity-data=PATH     Specify hash device for verity\n"
+               "     --pivot-root=PATH[:PATH]\n"
+               "                            Pivot root to given directory in the container\n\n"
+               "%3$sExecution:%4$s\n"
+               "  -a --as-pid2              Maintain a stub init as PID1, invoke binary as PID2\n"
+               "  -b --boot                 Boot up full system (i.e. invoke init)\n"
+               "     --chdir=PATH           Set working directory in the container\n"
+               "  -E --setenv=NAME=VALUE    Pass an environment variable to PID 1\n"
+               "  -u --user=USER            Run the command under specified user or UID\n"
+               "     --kill-signal=SIGNAL   Select signal to use for shutting down PID 1\n"
+               "     --notify-ready=BOOLEAN Receive notifications from the child init process\n\n"
+               "%3$sSystem Identity:%4$s\n"
+               "  -M --machine=NAME         Set the machine name for the container\n"
+               "     --hostname=NAME        Override the hostname for the container\n"
+               "     --uuid=UUID            Set a specific machine UUID for the container\n\n"
+               "%3$sProperties:%4$s\n"
+               "  -S --slice=SLICE          Place the container in the specified slice\n"
+               "     --property=NAME=VALUE  Set scope unit property\n"
+               "     --register=BOOLEAN     Register container as machine\n"
+               "     --keep-unit            Do not register a scope for the machine, reuse\n"
+               "                            the service unit nspawn is running in\n\n"
+               "%3$sUser Namespacing:%4$s\n"
+               "  -U --private-users=pick   Run within user namespace, autoselect UID/GID range\n"
+               "     --private-users[=UIDBASE[:NUIDS]]\n"
+               "                            Similar, but with user configured UID/GID range\n"
+               "     --private-users-chown  Adjust OS tree ownership to private UID/GID range\n\n"
+               "%3$sNetworking:%4$s\n"
+               "     --private-network      Disable network in container\n"
+               "     --network-interface=INTERFACE\n"
+               "                            Assign an existing network interface to the\n"
+               "                            container\n"
+               "     --network-macvlan=INTERFACE\n"
+               "                            Create a macvlan network interface based on an\n"
+               "                            existing network interface to the container\n"
+               "     --network-ipvlan=INTERFACE\n"
+               "                            Create a ipvlan network interface based on an\n"
+               "                            existing network interface to the container\n"
+               "  -n --network-veth         Add a virtual Ethernet connection between host\n"
+               "                            and container\n"
+               "     --network-veth-extra=HOSTIF[:CONTAINERIF]\n"
+               "                            Add an additional virtual Ethernet link between\n"
+               "                            host and container\n"
+               "     --network-bridge=INTERFACE\n"
+               "                            Add a virtual Ethernet connection to the container\n"
+               "                            and attach it to an existing bridge on the host\n"
+               "     --network-zone=NAME    Similar, but attach the new interface to an\n"
+               "                            an automatically managed bridge interface\n"
+               "     --network-namespace-path=PATH\n"
+               "                            Set network namespace to the one represented by\n"
+               "                            the specified kernel namespace file node\n"
+               "  -p --port=[PROTOCOL:]HOSTPORT[:CONTAINERPORT]\n"
+               "                            Expose a container IP port on the host\n\n"
+               "%3$sSecurity:%4$s\n"
+               "     --capability=CAP       In addition to the default, retain specified\n"
+               "                            capability\n"
+               "     --drop-capability=CAP  Drop the specified capability from the default set\n"
+               "     --no-new-privileges    Set PR_SET_NO_NEW_PRIVS flag for container payload\n"
+               "     --system-call-filter=LIST|~LIST\n"
+               "                            Permit/prohibit specific system calls\n"
+               "  -Z --selinux-context=SECLABEL\n"
+               "                            Set the SELinux security context to be used by\n"
+               "                            processes in the container\n"
+               "  -L --selinux-apifs-context=SECLABEL\n"
+               "                            Set the SELinux security context to be used by\n"
+               "                            API/tmpfs file systems in the container\n\n"
+               "%3$sResources:%4$s\n"
+               "     --rlimit=NAME=LIMIT    Set a resource limit for the payload\n"
+               "     --oom-score-adjust=VALUE\n"
+               "                            Adjust the OOM score value for the payload\n"
+               "     --cpu-affinity=CPUS    Adjust the CPU affinity of the container\n"
+               "     --personality=ARCH     Pick personality for this container\n\n"
+               "%3$sIntegration:%4$s\n"
+               "     --resolv-conf=MODE     Select mode of /etc/resolv.conf initialization\n"
+               "     --timezone=MODE        Select mode of /etc/localtime initialization\n"
+               "     --link-journal=MODE    Link up guest journal, one of no, auto, guest, \n"
+               "                            host, try-guest, try-host\n"
+               "  -j                        Equivalent to --link-journal=try-guest\n\n"
+               "%3$sMounts:%4$s\n"
+               "     --bind=PATH[:PATH[:OPTIONS]]\n"
+               "                            Bind mount a file or directory from the host into\n"
+               "                            the container\n"
+               "     --bind-ro=PATH[:PATH[:OPTIONS]\n"
+               "                            Similar, but creates a read-only bind mount\n"
+               "     --inaccessible=PATH    Over-mount file node with inaccessible node to mask\n"
+               "                            it\n"
+               "     --tmpfs=PATH:[OPTIONS] Mount an empty tmpfs to the specified directory\n"
+               "     --overlay=PATH[:PATH...]:PATH\n"
+               "                            Create an overlay mount from the host to \n"
+               "                            the container\n"
+               "     --overlay-ro=PATH[:PATH...]:PATH\n"
+               "                            Similar, but creates a read-only overlay mount\n\n"
+               "%3$sInput/Output:%4$s\n"
+               "     --console=MODE         Select how stdin/stdout/stderr and /dev/console are\n"
+               "                            set up for the container.\n"
+               "  -P --pipe                 Equivalent to --console=pipe\n\n"
+               "%3$sCredentials:%4$s\n"
+               "     --set-credential=ID:VALUE\n"
+               "                            Pass a credential with literal value to container.\n"
+               "     --load-credential=ID:PATH\n"
+               "                            Load credential to pass to container from file or\n"
+               "                            AF_UNIX stream socket.\n"
+               "\nSee the %2$s for details.\n"
+               , program_invocation_short_name
+               , link
+               , ansi_underline(), ansi_normal()
+               , ansi_highlight(), ansi_normal()
+        );
+
+        return 0;
+}
+
+static int custom_mount_check_all(void) {
+        size_t i;
+
+        for (i = 0; i < arg_n_custom_mounts; i++) {
+                CustomMount *m = &arg_custom_mounts[i];
+
+                if (path_equal(m->destination, "/") && arg_userns_mode != USER_NAMESPACE_NO) {
+                        if (arg_userns_chown)
+                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                                       "--private-users-chown may not be combined with custom root mounts.");
+                        else if (arg_uid_shift == UID_INVALID)
+                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                                       "--private-users with automatic UID shift may not be combined with custom root mounts.");
+                }
+        }
+
+        return 0;
+}
+
+static int detect_unified_cgroup_hierarchy_from_environment(void) {
+        const char *e, *var = "SYSTEMD_NSPAWN_UNIFIED_HIERARCHY";
+        int r;
+
+        /* Allow the user to control whether the unified hierarchy is used */
+
+        e = getenv(var);
+        if (!e) {
+                /* $UNIFIED_CGROUP_HIERARCHY has been renamed to $SYSTEMD_NSPAWN_UNIFIED_HIERARCHY. */
+                var = "UNIFIED_CGROUP_HIERARCHY";
+                e = getenv(var);
+        }
+
+        if (!isempty(e)) {
+                r = parse_boolean(e);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to parse $%s: %m", var);
+                if (r > 0)
+                        arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_ALL;
+                else
+                        arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_NONE;
+        }
+
+        return 0;
+}
+
+static int detect_unified_cgroup_hierarchy_from_image(const char *directory) {
+        int r;
+
+        /* Let's inherit the mode to use from the host system, but let's take into consideration what systemd
+         * in the image actually supports. */
+        r = cg_all_unified();
+        if (r < 0)
+                return log_error_errno(r, "Failed to determine whether we are in all unified mode.");
+        if (r > 0) {
+                /* Unified cgroup hierarchy support was added in 230. Unfortunately the detection
+                 * routine only detects 231, so we'll have a false negative here for 230. */
+                r = systemd_installation_has_version(directory, 230);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to determine systemd version in container: %m");
+                if (r > 0)
+                        arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_ALL;
+                else
+                        arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_NONE;
+        } else if (cg_unified_controller(SYSTEMD_CGROUP_CONTROLLER) > 0) {
+                /* Mixed cgroup hierarchy support was added in 233 */
+                r = systemd_installation_has_version(directory, 233);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to determine systemd version in container: %m");
+                if (r > 0)
+                        arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_SYSTEMD;
+                else
+                        arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_NONE;
+        } else
+                arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_NONE;
+
+        log_debug("Using %s hierarchy for container.",
+                  arg_unified_cgroup_hierarchy == CGROUP_UNIFIED_NONE ? "legacy" :
+                  arg_unified_cgroup_hierarchy == CGROUP_UNIFIED_SYSTEMD ? "hybrid" : "unified");
+
+        return 0;
+}
+
+static int parse_capability_spec(const char *spec, uint64_t *ret_mask) {
+        uint64_t mask = 0;
+        int r;
+
+        for (;;) {
+                _cleanup_free_ char *t = NULL;
+
+                r = extract_first_word(&spec, &t, ",", 0);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to parse capability %s.", t);
+                if (r == 0)
+                        break;
+
+                if (streq(t, "help")) {
+                        for (int i = 0; i < capability_list_length(); i++) {
+                                const char *name;
+
+                                name = capability_to_name(i);
+                                if (name)
+                                        puts(name);
+                        }
+
+                        return 0; /* quit */
+                }
+
+                if (streq(t, "all"))
+                        mask = (uint64_t) -1;
+                else {
+                        r = capability_from_name(t);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to parse capability %s.", t);
+
+                        mask |= 1ULL << r;
+                }
+        }
+
+        *ret_mask = mask;
+        return 1; /* continue */
+}
+
+static int parse_share_ns_env(const char *name, unsigned long ns_flag) {
+        int r;
+
+        r = getenv_bool(name);
+        if (r == -ENXIO)
+                return 0;
+        if (r < 0)
+                return log_error_errno(r, "Failed to parse $%s: %m", name);
+
+        arg_clone_ns_flags = (arg_clone_ns_flags & ~ns_flag) | (r > 0 ? 0 : ns_flag);
+        arg_settings_mask |= SETTING_CLONE_NS_FLAGS;
+        return 0;
+}
+
+static int parse_mount_settings_env(void) {
+        const char *e;
+        int r;
+
+        r = getenv_bool("SYSTEMD_NSPAWN_TMPFS_TMP");
+        if (r < 0 && r != -ENXIO)
+                return log_error_errno(r, "Failed to parse $SYSTEMD_NSPAWN_TMPFS_TMP: %m");
+        if (r >= 0)
+                SET_FLAG(arg_mount_settings, MOUNT_APPLY_TMPFS_TMP, r > 0);
+
+        e = getenv("SYSTEMD_NSPAWN_API_VFS_WRITABLE");
+        if (streq_ptr(e, "network"))
+                arg_mount_settings |= MOUNT_APPLY_APIVFS_RO|MOUNT_APPLY_APIVFS_NETNS;
+
+        else if (e) {
+                r = parse_boolean(e);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to parse $SYSTEMD_NSPAWN_API_VFS_WRITABLE: %m");
+
+                SET_FLAG(arg_mount_settings, MOUNT_APPLY_APIVFS_RO, r == 0);
+                SET_FLAG(arg_mount_settings, MOUNT_APPLY_APIVFS_NETNS, false);
+        }
+
+        return 0;
+}
+
+static int parse_environment(void) {
+        const char *e;
+        int r;
+
+        r = parse_share_ns_env("SYSTEMD_NSPAWN_SHARE_NS_IPC", CLONE_NEWIPC);
+        if (r < 0)
+                return r;
+        r = parse_share_ns_env("SYSTEMD_NSPAWN_SHARE_NS_PID", CLONE_NEWPID);
+        if (r < 0)
+                return r;
+        r = parse_share_ns_env("SYSTEMD_NSPAWN_SHARE_NS_UTS", CLONE_NEWUTS);
+        if (r < 0)
+                return r;
+        r = parse_share_ns_env("SYSTEMD_NSPAWN_SHARE_SYSTEM", CLONE_NEWIPC|CLONE_NEWPID|CLONE_NEWUTS);
+        if (r < 0)
+                return r;
+
+        r = parse_mount_settings_env();
+        if (r < 0)
+                return r;
+
+        /* SYSTEMD_NSPAWN_USE_CGNS=0 can be used to disable CLONE_NEWCGROUP use,
+         * even if it is supported. If not supported, it has no effect. */
+        if (!cg_ns_supported())
+                arg_use_cgns = false;
+        else {
+                r = getenv_bool("SYSTEMD_NSPAWN_USE_CGNS");
+                if (r < 0) {
+                        if (r != -ENXIO)
+                                return log_error_errno(r, "Failed to parse $SYSTEMD_NSPAWN_USE_CGNS: %m");
+
+                        arg_use_cgns = true;
+                } else {
+                        arg_use_cgns = r > 0;
+                        arg_settings_mask |= SETTING_USE_CGNS;
+                }
+        }
+
+        e = getenv("SYSTEMD_NSPAWN_CONTAINER_SERVICE");
+        if (e)
+                arg_container_service_name = e;
+
+        return detect_unified_cgroup_hierarchy_from_environment();
+}
+
+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_INACCESSIBLE,
+                ARG_SHARE_SYSTEM,
+                ARG_REGISTER,
+                ARG_KEEP_UNIT,
+                ARG_NETWORK_INTERFACE,
+                ARG_NETWORK_MACVLAN,
+                ARG_NETWORK_IPVLAN,
+                ARG_NETWORK_BRIDGE,
+                ARG_NETWORK_ZONE,
+                ARG_NETWORK_VETH_EXTRA,
+                ARG_NETWORK_NAMESPACE_PATH,
+                ARG_PERSONALITY,
+                ARG_VOLATILE,
+                ARG_TEMPLATE,
+                ARG_PROPERTY,
+                ARG_PRIVATE_USERS,
+                ARG_KILL_SIGNAL,
+                ARG_SETTINGS,
+                ARG_CHDIR,
+                ARG_PIVOT_ROOT,
+                ARG_PRIVATE_USERS_CHOWN,
+                ARG_NOTIFY_READY,
+                ARG_ROOT_HASH,
+                ARG_ROOT_HASH_SIG,
+                ARG_VERITY_DATA,
+                ARG_SYSTEM_CALL_FILTER,
+                ARG_RLIMIT,
+                ARG_HOSTNAME,
+                ARG_NO_NEW_PRIVILEGES,
+                ARG_OOM_SCORE_ADJUST,
+                ARG_CPU_AFFINITY,
+                ARG_RESOLV_CONF,
+                ARG_TIMEZONE,
+                ARG_CONSOLE,
+                ARG_PIPE,
+                ARG_OCI_BUNDLE,
+                ARG_NO_PAGER,
+                ARG_SET_CREDENTIAL,
+                ARG_LOAD_CREDENTIAL,
+        };
+
+        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        },
+                { "no-new-privileges",      required_argument, NULL, ARG_NO_NEW_PRIVILEGES      },
+                { "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             },
+                { "inaccessible",           required_argument, NULL, ARG_INACCESSIBLE           },
+                { "machine",                required_argument, NULL, 'M'                        },
+                { "hostname",               required_argument, NULL, ARG_HOSTNAME               },
+                { "slice",                  required_argument, NULL, 'S'                        },
+                { "setenv",                 required_argument, NULL, 'E'                        },
+                { "selinux-context",        required_argument, NULL, 'Z'                        },
+                { "selinux-apifs-context",  required_argument, NULL, 'L'                        },
+                { "quiet",                  no_argument,       NULL, 'q'                        },
+                { "share-system",           no_argument,       NULL, ARG_SHARE_SYSTEM           }, /* not documented */
+                { "register",               required_argument, NULL, ARG_REGISTER               },
+                { "keep-unit",              no_argument,       NULL, ARG_KEEP_UNIT              },
+                { "network-interface",      required_argument, NULL, ARG_NETWORK_INTERFACE      },
+                { "network-macvlan",        required_argument, NULL, ARG_NETWORK_MACVLAN        },
+                { "network-ipvlan",         required_argument, NULL, ARG_NETWORK_IPVLAN         },
+                { "network-veth",           no_argument,       NULL, 'n'                        },
+                { "network-veth-extra",     required_argument, NULL, ARG_NETWORK_VETH_EXTRA     },
+                { "network-bridge",         required_argument, NULL, ARG_NETWORK_BRIDGE         },
+                { "network-zone",           required_argument, NULL, ARG_NETWORK_ZONE           },
+                { "network-namespace-path", required_argument, NULL, ARG_NETWORK_NAMESPACE_PATH },
+                { "personality",            required_argument, NULL, ARG_PERSONALITY            },
+                { "image",                  required_argument, NULL, 'i'                        },
+                { "volatile",               optional_argument, NULL, ARG_VOLATILE               },
+                { "port",                   required_argument, NULL, 'p'                        },
+                { "property",               required_argument, NULL, ARG_PROPERTY               },
+                { "private-users",          optional_argument, NULL, ARG_PRIVATE_USERS          },
+                { "private-users-chown",    optional_argument, NULL, ARG_PRIVATE_USERS_CHOWN    },
+                { "kill-signal",            required_argument, NULL, ARG_KILL_SIGNAL            },
+                { "settings",               required_argument, NULL, ARG_SETTINGS               },
+                { "chdir",                  required_argument, NULL, ARG_CHDIR                  },
+                { "pivot-root",             required_argument, NULL, ARG_PIVOT_ROOT             },
+                { "notify-ready",           required_argument, NULL, ARG_NOTIFY_READY           },
+                { "root-hash",              required_argument, NULL, ARG_ROOT_HASH              },
+                { "root-hash-sig",          required_argument, NULL, ARG_ROOT_HASH_SIG          },
+                { "verity-data",            required_argument, NULL, ARG_VERITY_DATA            },
+                { "system-call-filter",     required_argument, NULL, ARG_SYSTEM_CALL_FILTER     },
+                { "rlimit",                 required_argument, NULL, ARG_RLIMIT                 },
+                { "oom-score-adjust",       required_argument, NULL, ARG_OOM_SCORE_ADJUST       },
+                { "cpu-affinity",           required_argument, NULL, ARG_CPU_AFFINITY           },
+                { "resolv-conf",            required_argument, NULL, ARG_RESOLV_CONF            },
+                { "timezone",               required_argument, NULL, ARG_TIMEZONE               },
+                { "console",                required_argument, NULL, ARG_CONSOLE                },
+                { "pipe",                   no_argument,       NULL, ARG_PIPE                   },
+                { "oci-bundle",             required_argument, NULL, ARG_OCI_BUNDLE             },
+                { "no-pager",               no_argument,       NULL, ARG_NO_PAGER               },
+                { "set-credential",         required_argument, NULL, ARG_SET_CREDENTIAL         },
+                { "load-credential",        required_argument, NULL, ARG_LOAD_CREDENTIAL        },
+                {}
+        };
+
+        int c, r;
+        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:nUE:P", options, NULL)) >= 0)
+                switch (c) {
+
+                case 'h':
+                        return help();
+
+                case ARG_VERSION:
+                        return version();
+
+                case 'D':
+                        r = parse_path_argument_and_warn(optarg, false, &arg_directory);
+                        if (r < 0)
+                                return r;
+
+                        arg_settings_mask |= SETTING_DIRECTORY;
+                        break;
+
+                case ARG_TEMPLATE:
+                        r = parse_path_argument_and_warn(optarg, false, &arg_template);
+                        if (r < 0)
+                                return r;
+
+                        arg_settings_mask |= SETTING_DIRECTORY;
+                        break;
+
+                case 'i':
+                        r = parse_path_argument_and_warn(optarg, false, &arg_image);
+                        if (r < 0)
+                                return r;
+
+                        arg_settings_mask |= SETTING_DIRECTORY;
+                        break;
+
+                case ARG_OCI_BUNDLE:
+                        r = parse_path_argument_and_warn(optarg, false, &arg_oci_bundle);
+                        if (r < 0)
+                                return r;
+
+                        break;
+
+                case 'x':
+                        arg_ephemeral = true;
+                        arg_settings_mask |= SETTING_EPHEMERAL;
+                        break;
+
+                case 'u':
+                        r = free_and_strdup(&arg_user, optarg);
+                        if (r < 0)
+                                return log_oom();
+
+                        arg_settings_mask |= SETTING_USER;
+                        break;
+
+                case ARG_NETWORK_ZONE: {
+                        char *j;
+
+                        j = strjoin("vz-", optarg);
+                        if (!j)
+                                return log_oom();
+
+                        if (!ifname_valid(j)) {
+                                log_error("Network zone name not valid: %s", j);
+                                free(j);
+                                return -EINVAL;
+                        }
+
+                        free_and_replace(arg_network_zone, j);
+
+                        arg_network_veth = true;
+                        arg_private_network = true;
+                        arg_settings_mask |= SETTING_NETWORK;
+                        break;
+                }
+
+                case ARG_NETWORK_BRIDGE:
+
+                        if (!ifname_valid(optarg))
+                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                                       "Bridge interface name not valid: %s", optarg);
+
+                        r = free_and_strdup(&arg_network_bridge, optarg);
+                        if (r < 0)
+                                return log_oom();
+
+                        _fallthrough_;
+                case 'n':
+                        arg_network_veth = true;
+                        arg_private_network = true;
+                        arg_settings_mask |= SETTING_NETWORK;
+                        break;
+
+                case ARG_NETWORK_VETH_EXTRA:
+                        r = veth_extra_parse(&arg_network_veth_extra, optarg);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to parse --network-veth-extra= parameter: %s", optarg);
+
+                        arg_private_network = true;
+                        arg_settings_mask |= SETTING_NETWORK;
+                        break;
+
+                case ARG_NETWORK_INTERFACE:
+                        if (!ifname_valid(optarg))
+                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                                       "Network interface name not valid: %s", optarg);
+
+                        r = test_network_interface_initialized(optarg);
+                        if (r < 0)
+                                return r;
+
+                        if (strv_extend(&arg_network_interfaces, optarg) < 0)
+                                return log_oom();
+
+                        arg_private_network = true;
+                        arg_settings_mask |= SETTING_NETWORK;
+                        break;
+
+                case ARG_NETWORK_MACVLAN:
+
+                        if (!ifname_valid(optarg))
+                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                                       "MACVLAN network interface name not valid: %s", optarg);
+
+                        r = test_network_interface_initialized(optarg);
+                        if (r < 0)
+                                return r;
+
+                        if (strv_extend(&arg_network_macvlan, optarg) < 0)
+                                return log_oom();
+
+                        arg_private_network = true;
+                        arg_settings_mask |= SETTING_NETWORK;
+                        break;
+
+                case ARG_NETWORK_IPVLAN:
+
+                        if (!ifname_valid(optarg))
+                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                                       "IPVLAN network interface name not valid: %s", optarg);
+
+                        r = test_network_interface_initialized(optarg);
+                        if (r < 0)
+                                return r;
+
+                        if (strv_extend(&arg_network_ipvlan, optarg) < 0)
+                                return log_oom();
+
+                        _fallthrough_;
+                case ARG_PRIVATE_NETWORK:
+                        arg_private_network = true;
+                        arg_settings_mask |= SETTING_NETWORK;
+                        break;
+
+                case ARG_NETWORK_NAMESPACE_PATH:
+                        r = parse_path_argument_and_warn(optarg, false, &arg_network_namespace_path);
+                        if (r < 0)
+                                return r;
+
+                        arg_settings_mask |= SETTING_NETWORK;
+                        break;
+
+                case 'b':
+                        if (arg_start_mode == START_PID2)
+                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                                       "--boot and --as-pid2 may not be combined.");
+
+                        arg_start_mode = START_BOOT;
+                        arg_settings_mask |= SETTING_START_MODE;
+                        break;
+
+                case 'a':
+                        if (arg_start_mode == START_BOOT)
+                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                                       "--boot and --as-pid2 may not be combined.");
+
+                        arg_start_mode = START_PID2;
+                        arg_settings_mask |= SETTING_START_MODE;
+                        break;
+
+                case ARG_UUID:
+                        r = sd_id128_from_string(optarg, &arg_uuid);
+                        if (r < 0)
+                                return log_error_errno(r, "Invalid UUID: %s", optarg);
+
+                        if (sd_id128_is_null(arg_uuid))
+                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                                       "Machine UUID may not be all zeroes.");
+
+                        arg_settings_mask |= SETTING_MACHINE_ID;
+                        break;
+
+                case 'S': {
+                        _cleanup_free_ char *mangled = NULL;
+
+                        r = unit_name_mangle_with_suffix(optarg, NULL, UNIT_NAME_MANGLE_WARN, ".slice", &mangled);
+                        if (r < 0)
+                                return log_oom();
+
+                        free_and_replace(arg_slice, mangled);
+                        arg_settings_mask |= SETTING_SLICE;
+                        break;
+                }
+
+                case 'M':
+                        if (isempty(optarg))
+                                arg_machine = mfree(arg_machine);
+                        else {
+                                if (!machine_name_is_valid(optarg))
+                                        return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                                               "Invalid machine name: %s", optarg);
+
+                                r = free_and_strdup(&arg_machine, optarg);
+                                if (r < 0)
+                                        return log_oom();
+                        }
+                        break;
+
+                case ARG_HOSTNAME:
+                        if (isempty(optarg))
+                                arg_hostname = mfree(arg_hostname);
+                        else {
+                                if (!hostname_is_valid(optarg, false))
+                                        return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                                               "Invalid hostname: %s", optarg);
+
+                                r = free_and_strdup(&arg_hostname, optarg);
+                                if (r < 0)
+                                        return log_oom();
+                        }
+
+                        arg_settings_mask |= SETTING_HOSTNAME;
+                        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: {
+                        uint64_t m;
+                        r = parse_capability_spec(optarg, &m);
+                        if (r <= 0)
+                                return r;
+
+                        if (c == ARG_CAPABILITY)
+                                plus |= m;
+                        else
+                                minus |= m;
+                        arg_settings_mask |= SETTING_CAPABILITY;
+                        break;
+                }
+                case ARG_NO_NEW_PRIVILEGES:
+                        r = parse_boolean(optarg);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to parse --no-new-privileges= argument: %s", optarg);
+
+                        arg_no_new_privileges = r;
+                        arg_settings_mask |= SETTING_NO_NEW_PRIVILEGES;
+                        break;
+
+                case 'j':
+                        arg_link_journal = LINK_GUEST;
+                        arg_link_journal_try = true;
+                        arg_settings_mask |= SETTING_LINK_JOURNAL;
+                        break;
+
+                case ARG_LINK_JOURNAL:
+                        r = parse_link_journal(optarg, &arg_link_journal, &arg_link_journal_try);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to parse link journal mode %s", optarg);
+
+                        arg_settings_mask |= SETTING_LINK_JOURNAL;
+                        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:
+                        r = overlay_mount_parse(&arg_custom_mounts, &arg_n_custom_mounts, optarg, c == ARG_OVERLAY_RO);
+                        if (r == -EADDRNOTAVAIL)
+                                return log_error_errno(r, "--overlay(-ro)= needs at least two colon-separated directories specified.");
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to parse --overlay(-ro)= argument %s: %m", optarg);
+
+                        arg_settings_mask |= SETTING_CUSTOM_MOUNTS;
+                        break;
+
+                case ARG_INACCESSIBLE:
+                        r = inaccessible_mount_parse(&arg_custom_mounts, &arg_n_custom_mounts, optarg);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to parse --inaccessible= argument %s: %m", optarg);
+
+                        arg_settings_mask |= SETTING_CUSTOM_MOUNTS;
+                        break;
+
+                case 'E': {
+                        char **n;
+
+                        if (!env_assignment_is_valid(optarg))
+                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                                       "Environment variable assignment '%s' is not valid.", optarg);
+
+                        n = strv_env_set(arg_setenv, optarg);
+                        if (!n)
+                                return log_oom();
+
+                        strv_free_and_replace(arg_setenv, n);
+                        arg_settings_mask |= SETTING_ENVIRONMENT;
+                        break;
+                }
+
+                case 'q':
+                        arg_quiet = true;
+                        break;
+
+                case ARG_SHARE_SYSTEM:
+                        /* We don't officially support this anymore, except for compat reasons. People should use the
+                         * $SYSTEMD_NSPAWN_SHARE_* environment variables instead. */
+                        log_warning("Please do not use --share-system anymore, use $SYSTEMD_NSPAWN_SHARE_* instead.");
+                        arg_clone_ns_flags = 0;
+                        break;
+
+                case ARG_REGISTER:
+                        r = parse_boolean(optarg);
+                        if (r < 0) {
+                                log_error("Failed to parse --register= argument: %s", optarg);
+                                return r;
+                        }
+
+                        arg_register = r;
+                        break;
+
+                case ARG_KEEP_UNIT:
+                        arg_keep_unit = true;
+                        break;
+
+                case ARG_PERSONALITY:
+
+                        arg_personality = personality_from_string(optarg);
+                        if (arg_personality == PERSONALITY_INVALID)
+                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                                       "Unknown or unsupported personality '%s'.", optarg);
+
+                        arg_settings_mask |= SETTING_PERSONALITY;
+                        break;
+
+                case ARG_VOLATILE:
+
+                        if (!optarg)
+                                arg_volatile_mode = VOLATILE_YES;
+                        else if (streq(optarg, "help")) {
+                                DUMP_STRING_TABLE(volatile_mode, VolatileMode, _VOLATILE_MODE_MAX);
+                                return 0;
+                        } else {
+                                VolatileMode m;
+
+                                m = volatile_mode_from_string(optarg);
+                                if (m < 0)
+                                        return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                                               "Failed to parse --volatile= argument: %s", optarg);
+                                else
+                                        arg_volatile_mode = m;
+                        }
+
+                        arg_settings_mask |= SETTING_VOLATILE_MODE;
+                        break;
+
+                case 'p':
+                        r = expose_port_parse(&arg_expose_ports, optarg);
+                        if (r == -EEXIST)
+                                return log_error_errno(r, "Duplicate port specification: %s", optarg);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to parse host port %s: %m", optarg);
+
+                        arg_settings_mask |= SETTING_EXPOSE_PORTS;
+                        break;
+
+                case ARG_PROPERTY:
+                        if (strv_extend(&arg_property, optarg) < 0)
+                                return log_oom();
+
+                        break;
+
+                case ARG_PRIVATE_USERS: {
+                        int boolean = -1;
+
+                        if (!optarg)
+                                boolean = true;
+                        else if (!in_charset(optarg, DIGITS))
+                                /* do *not* parse numbers as booleans */
+                                boolean = parse_boolean(optarg);
+
+                        if (boolean == false) {
+                                /* no: User namespacing off */
+                                arg_userns_mode = USER_NAMESPACE_NO;
+                                arg_uid_shift = UID_INVALID;
+                                arg_uid_range = UINT32_C(0x10000);
+                        } else if (boolean == true) {
+                                /* yes: User namespacing on, UID range is read from root dir */
+                                arg_userns_mode = USER_NAMESPACE_FIXED;
+                                arg_uid_shift = UID_INVALID;
+                                arg_uid_range = UINT32_C(0x10000);
+                        } else if (streq(optarg, "pick")) {
+                                /* pick: User namespacing on, UID range is picked randomly */
+                                arg_userns_mode = USER_NAMESPACE_PICK;
+                                arg_uid_shift = UID_INVALID;
+                                arg_uid_range = UINT32_C(0x10000);
+                        } else {
+                                _cleanup_free_ char *buffer = NULL;
+                                const char *range, *shift;
+
+                                /* anything else: User namespacing on, UID range is explicitly configured */
+
+                                range = strchr(optarg, ':');
+                                if (range) {
+                                        buffer = strndup(optarg, range - optarg);
+                                        if (!buffer)
+                                                return log_oom();
+                                        shift = buffer;
+
+                                        range++;
+                                        r = safe_atou32(range, &arg_uid_range);
+                                        if (r < 0)
+                                                return log_error_errno(r, "Failed to parse UID range \"%s\": %m", range);
+                                } else
+                                        shift = optarg;
+
+                                r = parse_uid(shift, &arg_uid_shift);
+                                if (r < 0)
+                                        return log_error_errno(r, "Failed to parse UID \"%s\": %m", optarg);
+
+                                arg_userns_mode = USER_NAMESPACE_FIXED;
+                        }
+
+                        if (arg_uid_range <= 0)
+                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                                       "UID range cannot be 0.");
+
+                        arg_settings_mask |= SETTING_USERNS;
+                        break;
+                }
+
+                case 'U':
+                        if (userns_supported()) {
+                                arg_userns_mode = USER_NAMESPACE_PICK;
+                                arg_uid_shift = UID_INVALID;
+                                arg_uid_range = UINT32_C(0x10000);
+
+                                arg_settings_mask |= SETTING_USERNS;
+                        }
+
+                        break;
+
+                case ARG_PRIVATE_USERS_CHOWN:
+                        arg_userns_chown = true;
+
+                        arg_settings_mask |= SETTING_USERNS;
+                        break;
+
+                case ARG_KILL_SIGNAL:
+                        if (streq(optarg, "help")) {
+                                DUMP_STRING_TABLE(signal, int, _NSIG);
+                                return 0;
+                        }
+
+                        arg_kill_signal = signal_from_string(optarg);
+                        if (arg_kill_signal < 0)
+                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                                       "Cannot parse signal: %s", optarg);
+
+                        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))
+                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                                       "Working directory %s is not an absolute path.", optarg);
+
+                        r = free_and_strdup(&arg_chdir, optarg);
+                        if (r < 0)
+                                return log_oom();
+
+                        arg_settings_mask |= SETTING_WORKING_DIRECTORY;
+                        break;
+
+                case ARG_PIVOT_ROOT:
+                        r = pivot_root_parse(&arg_pivot_root_new, &arg_pivot_root_old, optarg);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to parse --pivot-root= argument %s: %m", optarg);
+
+                        arg_settings_mask |= SETTING_PIVOT_ROOT;
+                        break;
+
+                case ARG_NOTIFY_READY:
+                        r = parse_boolean(optarg);
+                        if (r < 0)
+                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                                       "%s is not a valid notify mode. Valid modes are: yes, no, and ready.", optarg);
+                        arg_notify_ready = r;
+                        arg_settings_mask |= SETTING_NOTIFY_READY;
+                        break;
+
+                case ARG_ROOT_HASH: {
+                        _cleanup_free_ void *k = NULL;
+                        size_t l;
+
+                        r = unhexmem(optarg, strlen(optarg), &k, &l);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to parse root hash: %s", optarg);
+                        if (l < sizeof(sd_id128_t))
+                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Root hash must be at least 128bit long: %s", optarg);
+
+                        free_and_replace(arg_verity_settings.root_hash, k);
+                        arg_verity_settings.root_hash_size = l;
+                        break;
+                }
+
+                case ARG_ROOT_HASH_SIG: {
+                        char *value;
+                        size_t l;
+                        void *p;
+
+                        if ((value = startswith(optarg, "base64:"))) {
+                                r = unbase64mem(value, strlen(value), &p, &l);
+                                if (r < 0)
+                                        return log_error_errno(r, "Failed to parse root hash signature '%s': %m", optarg);
+
+                        } else {
+                                r = read_full_file(optarg, (char**) &p, &l);
+                                if (r < 0)
+                                        return log_error_errno(r, "Failed parse root hash signature file '%s': %m", optarg);
+                        }
+
+                        free_and_replace(arg_verity_settings.root_hash_sig, p);
+                        arg_verity_settings.root_hash_sig_size = l;
+                        break;
+                }
+
+                case ARG_VERITY_DATA:
+                        r = parse_path_argument_and_warn(optarg, false, &arg_verity_settings.data_path);
+                        if (r < 0)
+                                return r;
+                        break;
+
+                case ARG_SYSTEM_CALL_FILTER: {
+                        bool negative;
+                        const char *items;
+
+                        negative = optarg[0] == '~';
+                        items = negative ? optarg + 1 : optarg;
+
+                        for (;;) {
+                                _cleanup_free_ char *word = NULL;
+
+                                r = extract_first_word(&items, &word, NULL, 0);
+                                if (r == 0)
+                                        break;
+                                if (r == -ENOMEM)
+                                        return log_oom();
+                                if (r < 0)
+                                        return log_error_errno(r, "Failed to parse system call filter: %m");
+
+                                if (negative)
+                                        r = strv_extend(&arg_syscall_deny_list, word);
+                                else
+                                        r = strv_extend(&arg_syscall_allow_list, word);
+                                if (r < 0)
+                                        return log_oom();
+                        }
+
+                        arg_settings_mask |= SETTING_SYSCALL_FILTER;
+                        break;
+                }
+
+                case ARG_RLIMIT: {
+                        const char *eq;
+                        _cleanup_free_ char *name = NULL;
+                        int rl;
+
+                        if (streq(optarg, "help")) {
+                                DUMP_STRING_TABLE(rlimit, int, _RLIMIT_MAX);
+                                return 0;
+                        }
+
+                        eq = strchr(optarg, '=');
+                        if (!eq)
+                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                                       "--rlimit= expects an '=' assignment.");
+
+                        name = strndup(optarg, eq - optarg);
+                        if (!name)
+                                return log_oom();
+
+                        rl = rlimit_from_string_harder(name);
+                        if (rl < 0)
+                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                                       "Unknown resource limit: %s", name);
+
+                        if (!arg_rlimit[rl]) {
+                                arg_rlimit[rl] = new0(struct rlimit, 1);
+                                if (!arg_rlimit[rl])
+                                        return log_oom();
+                        }
+
+                        r = rlimit_parse(rl, eq + 1, arg_rlimit[rl]);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to parse resource limit: %s", eq + 1);
+
+                        arg_settings_mask |= SETTING_RLIMIT_FIRST << rl;
+                        break;
+                }
+
+                case ARG_OOM_SCORE_ADJUST:
+                        r = parse_oom_score_adjust(optarg, &arg_oom_score_adjust);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to parse --oom-score-adjust= parameter: %s", optarg);
+
+                        arg_oom_score_adjust_set = true;
+                        arg_settings_mask |= SETTING_OOM_SCORE_ADJUST;
+                        break;
+
+                case ARG_CPU_AFFINITY: {
+                        CPUSet cpuset;
+
+                        r = parse_cpu_set(optarg, &cpuset);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to parse CPU affinity mask %s: %m", optarg);
+
+                        cpu_set_reset(&arg_cpu_set);
+                        arg_cpu_set = cpuset;
+                        arg_settings_mask |= SETTING_CPU_AFFINITY;
+                        break;
+                }
+
+                case ARG_RESOLV_CONF:
+                        if (streq(optarg, "help")) {
+                                DUMP_STRING_TABLE(resolv_conf_mode, ResolvConfMode, _RESOLV_CONF_MODE_MAX);
+                                return 0;
+                        }
+
+                        arg_resolv_conf = resolv_conf_mode_from_string(optarg);
+                        if (arg_resolv_conf < 0)
+                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                                       "Failed to parse /etc/resolv.conf mode: %s", optarg);
+
+                        arg_settings_mask |= SETTING_RESOLV_CONF;
+                        break;
+
+                case ARG_TIMEZONE:
+                        if (streq(optarg, "help")) {
+                                DUMP_STRING_TABLE(timezone_mode, TimezoneMode, _TIMEZONE_MODE_MAX);
+                                return 0;
+                        }
+
+                        arg_timezone = timezone_mode_from_string(optarg);
+                        if (arg_timezone < 0)
+                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                                       "Failed to parse /etc/localtime mode: %s", optarg);
+
+                        arg_settings_mask |= SETTING_TIMEZONE;
+                        break;
+
+                case ARG_CONSOLE:
+                        r = handle_arg_console(optarg);
+                        if (r <= 0)
+                                return r;
+                        break;
+
+                case 'P':
+                case ARG_PIPE:
+                        r = handle_arg_console("pipe");
+                        if (r <= 0)
+                                return r;
+                        break;
+
+                case ARG_NO_PAGER:
+                        arg_pager_flags |= PAGER_DISABLE;
+                        break;
+
+                case ARG_SET_CREDENTIAL: {
+                        _cleanup_free_ char *word = NULL, *data = NULL;
+                        const char *p = optarg;
+                        Credential *a;
+                        size_t i;
+                        int l;
+
+                        r = extract_first_word(&p, &word, ":", EXTRACT_DONT_COALESCE_SEPARATORS);
+                        if (r == -ENOMEM)
+                                return log_oom();
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to parse --set-credential= parameter: %m");
+                        if (r == 0 || !p)
+                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Missing value for --set-credential=: %s", optarg);
+
+                        if (!credential_name_valid(word))
+                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Credential name is not valid: %s", word);
+
+                        for (i = 0; i < arg_n_credentials; i++)
+                                if (streq(arg_credentials[i].id, word))
+                                        return log_error_errno(SYNTHETIC_ERRNO(EEXIST), "Duplicate credential '%s', refusing.", word);
+
+                        l = cunescape(p, UNESCAPE_ACCEPT_NUL, &data);
+                        if (l < 0)
+                                return log_error_errno(l, "Failed to unescape credential data: %s", p);
+
+                        a = reallocarray(arg_credentials, arg_n_credentials + 1, sizeof(Credential));
+                        if (!a)
+                                return log_oom();
+
+                        a[arg_n_credentials++] = (Credential) {
+                                .id = TAKE_PTR(word),
+                                .data = TAKE_PTR(data),
+                                .size = l,
+                        };
+
+                        arg_credentials = a;
+
+                        arg_settings_mask |= SETTING_CREDENTIALS;
+                        break;
+                }
+
+                case ARG_LOAD_CREDENTIAL: {
+                        ReadFullFileFlags flags = READ_FULL_FILE_SECURE;
+                        _cleanup_(erase_and_freep) char *data = NULL;
+                        _cleanup_free_ char *word = NULL, *j = NULL;
+                        const char *p = optarg;
+                        Credential *a;
+                        size_t size, i;
+
+                        r = extract_first_word(&p, &word, ":", EXTRACT_DONT_COALESCE_SEPARATORS);
+                        if (r == -ENOMEM)
+                                return log_oom();
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to parse --set-credential= parameter: %m");
+                        if (r == 0 || !p)
+                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Missing value for --set-credential=: %s", optarg);
+
+                        if (!credential_name_valid(word))
+                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Credential name is not valid: %s", word);
+
+                        for (i = 0; i < arg_n_credentials; i++)
+                                if (streq(arg_credentials[i].id, word))
+                                        return log_error_errno(SYNTHETIC_ERRNO(EEXIST), "Duplicate credential '%s', refusing.", word);
+
+                        if (path_is_absolute(p))
+                                flags |= READ_FULL_FILE_CONNECT_SOCKET;
+                        else {
+                                const char *e;
+
+                                e = getenv("CREDENTIALS_DIRECTORY");
+                                if (!e)
+                                        return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Credential not available (no credentials passed at all): %s", word);
+
+                                j = path_join(e, p);
+                                if (!j)
+                                        return log_oom();
+                        }
+
+                        r = read_full_file_full(AT_FDCWD, j ?: p, flags, NULL, &data, &size);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to read credential '%s': %m", j ?: p);
+
+                        a = reallocarray(arg_credentials, arg_n_credentials + 1, sizeof(Credential));
+                        if (!a)
+                                return log_oom();
+
+                        a[arg_n_credentials++] = (Credential) {
+                                .id = TAKE_PTR(word),
+                                .data = TAKE_PTR(data),
+                                .size = size,
+                        };
+
+                        arg_credentials = a;
+
+                        arg_settings_mask |= SETTING_CREDENTIALS;
+                        break;
+                }
+
+                case '?':
+                        return -EINVAL;
+
+                default:
+                        assert_not_reached("Unhandled option");
+                }
+
+        if (argc > optind) {
+                strv_free(arg_parameters);
+                arg_parameters = strv_copy(argv + optind);
+                if (!arg_parameters)
+                        return log_oom();
+
+                arg_settings_mask |= SETTING_START_MODE;
+        }
+
+        if (arg_ephemeral && arg_template && !arg_directory)
+                /* User asked for ephemeral execution but specified --template= instead of --directory=. Semantically
+                 * such an invocation makes some sense, see https://github.com/systemd/systemd/issues/3667. Let's
+                 * accept this here, and silently make "--ephemeral --template=" equivalent to "--ephemeral
+                 * --directory=". */
+                arg_directory = TAKE_PTR(arg_template);
+
+        arg_caps_retain = (arg_caps_retain | plus | (arg_private_network ? UINT64_C(1) << CAP_NET_ADMIN : 0)) & ~minus;
+
+        /* Make sure to parse environment before we reset the settings mask below */
+        r = parse_environment();
+        if (r < 0)
+                return r;
+
+        /* 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;
+
+        return 1;
+}
+
+static int verify_arguments(void) {
+        int r;
+
+        if (arg_start_mode == START_PID2 && arg_unified_cgroup_hierarchy == CGROUP_UNIFIED_UNKNOWN) {
+                /* If we are running the stub init in the container, we don't need to look at what the init
+                 * in the container supports, because we are not using it. Let's immediately pick the right
+                 * setting based on the host system configuration.
+                 *
+                 * We only do this, if the user didn't use an environment variable to override the detection.
+                 */
+
+                r = cg_all_unified();
+                if (r < 0)
+                        return log_error_errno(r, "Failed to determine whether we are in all unified mode.");
+                if (r > 0)
+                        arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_ALL;
+                else if (cg_unified_controller(SYSTEMD_CGROUP_CONTROLLER) > 0)
+                        arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_SYSTEMD;
+                else
+                        arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_NONE;
+        }
+
+        if (arg_userns_mode != USER_NAMESPACE_NO)
+                arg_mount_settings |= MOUNT_USE_USERNS;
+
+        if (arg_private_network)
+                arg_mount_settings |= MOUNT_APPLY_APIVFS_NETNS;
+
+        if (!(arg_clone_ns_flags & CLONE_NEWPID) ||
+            !(arg_clone_ns_flags & CLONE_NEWUTS)) {
+                arg_register = false;
+                if (arg_start_mode != START_PID1)
+                        return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "--boot cannot be used without namespacing.");
+        }
+
+        if (arg_userns_mode == USER_NAMESPACE_PICK)
+                arg_userns_chown = true;
+
+        if (arg_start_mode == START_BOOT && arg_kill_signal <= 0)
+                arg_kill_signal = SIGRTMIN+3;
+
+        if (arg_volatile_mode != VOLATILE_NO) /* Make sure all file systems contained in the image are mounted read-only if we are in volatile mode */
+                arg_read_only = true;
+
+        if (has_custom_root_mount(arg_custom_mounts, arg_n_custom_mounts))
+                arg_read_only = true;
+
+        if (arg_keep_unit && arg_register && cg_pid_get_owner_uid(0, NULL) >= 0)
+                /* Save the user from accidentally registering either user-$SESSION.scope or user@.service.
+                 * The latter is not technically a user session, but we don't need to labour the point. */
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "--keep-unit --register=yes may not be used when invoked from a user session.");
+
+        if (arg_directory && arg_image)
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "--directory= and --image= may not be combined.");
+
+        if (arg_template && arg_image)
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "--template= and --image= may not be combined.");
+
+        if (arg_template && !(arg_directory || arg_machine))
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "--template= needs --directory= or --machine=.");
+
+        if (arg_ephemeral && arg_template)
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "--ephemeral and --template= may not be combined.");
+
+        if (arg_ephemeral && !IN_SET(arg_link_journal, LINK_NO, LINK_AUTO))
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "--ephemeral and --link-journal= may not be combined.");
+
+        if (arg_userns_mode != USER_NAMESPACE_NO && !userns_supported())
+                return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "--private-users= is not supported, kernel compiled without user namespace support.");
+
+        if (arg_userns_chown && arg_read_only)
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                       "--read-only and --private-users-chown may not be combined.");
+
+        /* We don't support --private-users-chown together with any of the volatile modes since we couldn't
+         * change the read-only part of the tree (i.e. /usr) anyway, or because it would trigger a massive
+         * copy-up (in case of overlay) making the entire exercise pointless. */
+        if (arg_userns_chown && arg_volatile_mode != VOLATILE_NO)
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "--volatile= and --private-users-chown may not be combined.");
+
+        /* If --network-namespace-path is given with any other network-related option (except --private-network),
+         * we need to error out, to avoid conflicts between different network options. */
+        if (arg_network_namespace_path &&
+                (arg_network_interfaces || arg_network_macvlan ||
+                 arg_network_ipvlan || arg_network_veth_extra ||
+                 arg_network_bridge || arg_network_zone ||
+                 arg_network_veth))
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "--network-namespace-path= cannot be combined with other network options.");
+
+        if (arg_network_bridge && arg_network_zone)
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                       "--network-bridge= and --network-zone= may not be combined.");
+
+        if (arg_userns_mode != USER_NAMESPACE_NO && (arg_mount_settings & MOUNT_APPLY_APIVFS_NETNS) && !arg_private_network)
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Invalid namespacing settings. Mounting sysfs with --private-users requires --private-network.");
+
+        if (arg_userns_mode != USER_NAMESPACE_NO && !(arg_mount_settings & MOUNT_APPLY_APIVFS_RO))
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Cannot combine --private-users with read-write mounts.");
+
+        if (arg_expose_ports && !arg_private_network)
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Cannot use --port= without private networking.");
+
+#if ! HAVE_LIBIPTC
+        if (arg_expose_ports)
+                return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "--port= is not supported, compiled without libiptc support.");
+#endif
+
+        r = custom_mount_check_all();
+        if (r < 0)
+                return r;
+
+        return 0;
+}
+
+static int userns_lchown(const char *p, uid_t uid, gid_t gid) {
+        assert(p);
+
+        if (arg_userns_mode == USER_NAMESPACE_NO)
+                return 0;
+
+        if (uid == UID_INVALID && gid == GID_INVALID)
+                return 0;
+
+        if (uid != UID_INVALID) {
+                uid += arg_uid_shift;
+
+                if (uid < arg_uid_shift || uid >= arg_uid_shift + arg_uid_range)
+                        return -EOVERFLOW;
+        }
+
+        if (gid != GID_INVALID) {
+                gid += (gid_t) arg_uid_shift;
+
+                if (gid < (gid_t) arg_uid_shift || gid >= (gid_t) (arg_uid_shift + arg_uid_range))
+                        return -EOVERFLOW;
+        }
+
+        if (lchown(p, uid, gid) < 0)
+                return -errno;
+
+        return 0;
+}
+
+static int userns_mkdir(const char *root, const char *path, mode_t mode, uid_t uid, gid_t gid) {
+        const char *q;
+        int r;
+
+        q = prefix_roota(root, path);
+        r = mkdir_errno_wrapper(q, mode);
+        if (r == -EEXIST)
+                return 0;
+        if (r < 0)
+                return r;
+
+        return userns_lchown(q, uid, gid);
+}
+
+static const char *timezone_from_path(const char *path) {
+        return PATH_STARTSWITH_SET(
+                        path,
+                        "../usr/share/zoneinfo/",
+                        "/usr/share/zoneinfo/");
+}
+
+static bool etc_writable(void) {
+        return !arg_read_only || IN_SET(arg_volatile_mode, VOLATILE_YES, VOLATILE_OVERLAY);
+}
+
+static int setup_timezone(const char *dest) {
+        _cleanup_free_ char *p = NULL, *etc = NULL;
+        const char *where, *check;
+        TimezoneMode m;
+        int r;
+
+        assert(dest);
+
+        if (IN_SET(arg_timezone, TIMEZONE_AUTO, TIMEZONE_SYMLINK)) {
+                r = readlink_malloc("/etc/localtime", &p);
+                if (r == -ENOENT && arg_timezone == TIMEZONE_AUTO)
+                        m = etc_writable() ? TIMEZONE_DELETE : TIMEZONE_OFF;
+                else if (r == -EINVAL && arg_timezone == TIMEZONE_AUTO) /* regular file? */
+                        m = etc_writable() ? TIMEZONE_COPY : TIMEZONE_BIND;
+                else if (r < 0) {
+                        log_warning_errno(r, "Failed to read host's /etc/localtime symlink, not updating container timezone: %m");
+                        /* To handle warning, delete /etc/localtime and replace it with a symbolic link to a time zone data
+                         * file.
+                         *
+                         * Example:
+                         * ln -s /usr/share/zoneinfo/UTC /etc/localtime
+                         */
+                        return 0;
+                } else if (arg_timezone == TIMEZONE_AUTO)
+                        m = etc_writable() ? TIMEZONE_SYMLINK : TIMEZONE_BIND;
+                else
+                        m = arg_timezone;
+        } else
+                m = arg_timezone;
+
+        if (m == TIMEZONE_OFF)
+                return 0;
+
+        r = chase_symlinks("/etc", dest, CHASE_PREFIX_ROOT, &etc, NULL);
+        if (r < 0) {
+                log_warning_errno(r, "Failed to resolve /etc path in container, ignoring: %m");
+                return 0;
+        }
+
+        where = strjoina(etc, "/localtime");
+
+        switch (m) {
+
+        case TIMEZONE_DELETE:
+                if (unlink(where) < 0)
+                        log_full_errno(errno == ENOENT ? LOG_DEBUG : LOG_WARNING, errno, "Failed to remove '%s', ignoring: %m", where);
+
+                return 0;
+
+        case TIMEZONE_SYMLINK: {
+                _cleanup_free_ char *q = NULL;
+                const char *z, *what;
+
+                z = timezone_from_path(p);
+                if (!z) {
+                        log_warning("/etc/localtime does not point into /usr/share/zoneinfo/, not updating container timezone.");
+                        return 0;
+                }
+
+                r = readlink_malloc(where, &q);
+                if (r >= 0 && streq_ptr(timezone_from_path(q), z))
+                        return 0; /* Already pointing to the right place? Then do nothing .. */
+
+                check = strjoina(dest, "/usr/share/zoneinfo/", z);
+                r = chase_symlinks(check, dest, 0, NULL, NULL);
+                if (r < 0)
+                        log_debug_errno(r, "Timezone %s does not exist (or is not accessible) in container, not creating symlink: %m", z);
+                else {
+                        if (unlink(where) < 0 && errno != ENOENT) {
+                                log_full_errno(IN_SET(errno, EROFS, EACCES, EPERM) ? LOG_DEBUG : LOG_WARNING, /* Don't complain on read-only images */
+                                               errno, "Failed to remove existing timezone info %s in container, ignoring: %m", where);
+                                return 0;
+                        }
+
+                        what = strjoina("../usr/share/zoneinfo/", z);
+                        if (symlink(what, where) < 0) {
+                                log_full_errno(IN_SET(errno, EROFS, EACCES, EPERM) ? LOG_DEBUG : LOG_WARNING,
+                                               errno, "Failed to correct timezone of container, ignoring: %m");
+                                return 0;
+                        }
+
+                        break;
+                }
+
+                _fallthrough_;
+        }
+
+        case TIMEZONE_BIND: {
+                _cleanup_free_ char *resolved = NULL;
+                int found;
+
+                found = chase_symlinks(where, dest, CHASE_NONEXISTENT, &resolved, NULL);
+                if (found < 0) {
+                        log_warning_errno(found, "Failed to resolve /etc/localtime path in container, ignoring: %m");
+                        return 0;
+                }
+
+                if (found == 0) /* missing? */
+                        (void) touch(resolved);
+
+                r = mount_nofollow_verbose(LOG_WARNING, "/etc/localtime", resolved, NULL, MS_BIND, NULL);
+                if (r >= 0)
+                        return mount_nofollow_verbose(LOG_ERR, NULL, resolved, NULL, MS_BIND|MS_REMOUNT|MS_RDONLY|MS_NOSUID|MS_NODEV, NULL);
+
+                _fallthrough_;
+        }
+
+        case TIMEZONE_COPY:
+                /* If mounting failed, try to copy */
+                r = copy_file_atomic("/etc/localtime", where, 0644, 0, 0, COPY_REFLINK|COPY_REPLACE);
+                if (r < 0) {
+                        log_full_errno(IN_SET(r, -EROFS, -EACCES, -EPERM) ? LOG_DEBUG : LOG_WARNING, r,
+                                       "Failed to copy /etc/localtime to %s, ignoring: %m", where);
+                        return 0;
+                }
+
+                break;
+
+        default:
+                assert_not_reached("unexpected mode");
+        }
+
+        /* Fix permissions of the symlink or file copy we just created */
+        r = userns_lchown(where, 0, 0);
+        if (r < 0)
+                log_warning_errno(r, "Failed to chown /etc/localtime, ignoring: %m");
+
+        return 0;
+}
+
+static int have_resolv_conf(const char *path) {
+        assert(path);
+
+        if (access(path, F_OK) < 0) {
+                if (errno == ENOENT)
+                        return 0;
+
+                return log_debug_errno(errno, "Failed to determine whether '%s' is available: %m", path);
+        }
+
+        return 1;
+}
+
+static int resolved_listening(void) {
+        _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
+        _cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL;
+        _cleanup_free_ char *dns_stub_listener_mode = NULL;
+        int r;
+
+        /* Check if resolved is listening */
+
+        r = sd_bus_open_system(&bus);
+        if (r < 0)
+                return log_debug_errno(r, "Failed to open system bus: %m");
+
+        r = bus_name_has_owner(bus, "org.freedesktop.resolve1", NULL);
+        if (r < 0)
+                return log_debug_errno(r, "Failed to check whether the 'org.freedesktop.resolve1' bus name is taken: %m");
+        if (r == 0)
+                return 0;
+
+        r = sd_bus_get_property_string(bus,
+                                       "org.freedesktop.resolve1",
+                                       "/org/freedesktop/resolve1",
+                                       "org.freedesktop.resolve1.Manager",
+                                       "DNSStubListener",
+                                       &error,
+                                       &dns_stub_listener_mode);
+        if (r < 0)
+                return log_debug_errno(r, "Failed to query DNSStubListener property: %s", bus_error_message(&error, r));
+
+        return STR_IN_SET(dns_stub_listener_mode, "udp", "yes");
+}
+
+static int setup_resolv_conf(const char *dest) {
+        _cleanup_free_ char *etc = NULL;
+        const char *where, *what;
+        ResolvConfMode m;
+        int r;
+
+        assert(dest);
+
+        if (arg_resolv_conf == RESOLV_CONF_AUTO) {
+                if (arg_private_network)
+                        m = RESOLV_CONF_OFF;
+                else if (have_resolv_conf(PRIVATE_STUB_RESOLV_CONF) > 0 && resolved_listening() > 0)
+                        m = etc_writable() ? RESOLV_CONF_COPY_STUB : RESOLV_CONF_BIND_STUB;
+                else if (have_resolv_conf("/etc/resolv.conf") > 0)
+                        m = etc_writable() ? RESOLV_CONF_COPY_HOST : RESOLV_CONF_BIND_HOST;
+                else
+                        m = etc_writable() ? RESOLV_CONF_DELETE : RESOLV_CONF_OFF;
+
+        } else
+                m = arg_resolv_conf;
+
+        if (m == RESOLV_CONF_OFF)
+                return 0;
+
+        r = chase_symlinks("/etc", dest, CHASE_PREFIX_ROOT, &etc, NULL);
+        if (r < 0) {
+                log_warning_errno(r, "Failed to resolve /etc path in container, ignoring: %m");
+                return 0;
+        }
+
+        where = strjoina(etc, "/resolv.conf");
+
+        if (m == RESOLV_CONF_DELETE) {
+                if (unlink(where) < 0)
+                        log_full_errno(errno == ENOENT ? LOG_DEBUG : LOG_WARNING, errno, "Failed to remove '%s', ignoring: %m", where);
+
+                return 0;
+        }
+
+        if (IN_SET(m, RESOLV_CONF_BIND_STATIC, RESOLV_CONF_REPLACE_STATIC, RESOLV_CONF_COPY_STATIC))
+                what = PRIVATE_STATIC_RESOLV_CONF;
+        else if (IN_SET(m, RESOLV_CONF_BIND_UPLINK, RESOLV_CONF_REPLACE_UPLINK, RESOLV_CONF_COPY_UPLINK))
+                what = PRIVATE_UPLINK_RESOLV_CONF;
+        else if (IN_SET(m, RESOLV_CONF_BIND_STUB, RESOLV_CONF_REPLACE_STUB, RESOLV_CONF_COPY_STUB))
+                what = PRIVATE_STUB_RESOLV_CONF;
+        else
+                what = "/etc/resolv.conf";
+
+        if (IN_SET(m, RESOLV_CONF_BIND_HOST, RESOLV_CONF_BIND_STATIC, RESOLV_CONF_BIND_UPLINK, RESOLV_CONF_BIND_STUB)) {
+                _cleanup_free_ char *resolved = NULL;
+                int found;
+
+                found = chase_symlinks(where, dest, CHASE_NONEXISTENT, &resolved, NULL);
+                if (found < 0) {
+                        log_warning_errno(found, "Failed to resolve /etc/resolv.conf path in container, ignoring: %m");
+                        return 0;
+                }
+
+                if (found == 0) /* missing? */
+                        (void) touch(resolved);
+
+                r = mount_nofollow_verbose(LOG_WARNING, what, resolved, NULL, MS_BIND, NULL);
+                if (r >= 0)
+                        return mount_nofollow_verbose(LOG_ERR, NULL, resolved, NULL, MS_BIND|MS_REMOUNT|MS_RDONLY|MS_NOSUID|MS_NODEV, NULL);
+
+                /* If that didn't work, let's copy the file */
+        }
+
+        if (IN_SET(m, RESOLV_CONF_REPLACE_HOST, RESOLV_CONF_REPLACE_STATIC, RESOLV_CONF_REPLACE_UPLINK, RESOLV_CONF_REPLACE_STUB))
+                r = copy_file_atomic(what, where, 0644, 0, 0, COPY_REFLINK|COPY_REPLACE);
+        else
+                r = copy_file(what, where, O_TRUNC|O_NOFOLLOW, 0644, 0, 0, COPY_REFLINK);
+        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(RESOLV_CONF_COPY_HOST, RESOLV_CONF_COPY_STATIC, RESOLV_CONF_COPY_UPLINK, RESOLV_CONF_COPY_STUB) &&
+                               IN_SET(r, -ELOOP, -EROFS, -EACCES, -EPERM) ? LOG_DEBUG : LOG_WARNING, r,
+                               "Failed to copy /etc/resolv.conf to %s, ignoring: %m", where);
+                return 0;
+        }
+
+        r = userns_lchown(where, 0, 0);
+        if (r < 0)
+                log_warning_errno(r, "Failed to chown /etc/resolv.conf, ignoring: %m");
+
+        return 0;
+}
+
+static int setup_boot_id(void) {
+        _cleanup_(unlink_and_freep) char *from = NULL;
+        _cleanup_free_ char *path = NULL;
+        sd_id128_t rnd = SD_ID128_NULL;
+        const char *to;
+        int r;
+
+        /* Generate a new randomized boot ID, so that each boot-up of the container gets a new one */
+
+        r = tempfn_random_child("/run", "proc-sys-kernel-random-boot-id", &path);
+        if (r < 0)
+                return log_error_errno(r, "Failed to generate random boot ID path: %m");
+
+        r = sd_id128_randomize(&rnd);
+        if (r < 0)
+                return log_error_errno(r, "Failed to generate random boot id: %m");
+
+        r = id128_write(path, ID128_UUID, rnd, false);
+        if (r < 0)
+                return log_error_errno(r, "Failed to write boot id: %m");
+
+        from = TAKE_PTR(path);
+        to = "/proc/sys/kernel/random/boot_id";
+
+        r = mount_nofollow_verbose(LOG_ERR, from, to, NULL, MS_BIND, NULL);
+        if (r < 0)
+                return r;
+
+        return mount_nofollow_verbose(LOG_ERR, NULL, to, NULL, MS_BIND|MS_REMOUNT|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV, NULL);
+}
+
+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";
+
+        _cleanup_umask_ mode_t u;
+        const char *d;
+        int r = 0;
+
+        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 = path_join("/dev/", d);
+                if (!from)
+                        return log_oom();
+
+                to = path_join(dest, from);
+                if (!to)
+                        return log_oom();
+
+                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))
+                        return log_error_errno(SYNTHETIC_ERRNO(EIO),
+                                               "%s is not a char or block device, cannot copy.", from);
+                else {
+                        _cleanup_free_ char *sl = NULL, *prefixed = NULL, *dn = NULL, *t = NULL;
+
+                        if (mknod(to, st.st_mode, st.st_rdev) < 0) {
+                                /* Explicitly warn the user when /dev is already populated. */
+                                if (errno == EEXIST)
+                                        log_notice("%s/dev is pre-mounted and pre-populated. If a pre-mounted /dev is provided it needs to be an unpopulated file system.", dest);
+                                if (errno != EPERM)
+                                        return log_error_errno(errno, "mknod(%s) failed: %m", to);
+
+                                /* Some systems abusively restrict mknod but allow bind mounts. */
+                                r = touch(to);
+                                if (r < 0)
+                                        return log_error_errno(r, "touch (%s) failed: %m", to);
+                                r = mount_nofollow_verbose(LOG_DEBUG, from, to, NULL, MS_BIND, NULL);
+                                if (r < 0)
+                                        return log_error_errno(r, "Both mknod and bind mount (%s) failed: %m", to);
+                        }
+
+                        r = userns_lchown(to, 0, 0);
+                        if (r < 0)
+                                return log_error_errno(r, "chown() of device node %s failed: %m", to);
+
+                        dn = path_join("/dev", S_ISCHR(st.st_mode) ? "char" : "block");
+                        if (!dn)
+                                return log_oom();
+
+                        r = userns_mkdir(dest, dn, 0755, 0, 0);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to create '%s': %m", dn);
+
+                        if (asprintf(&sl, "%s/%u:%u", dn, major(st.st_rdev), minor(st.st_rdev)) < 0)
+                                return log_oom();
+
+                        prefixed = path_join(dest, sl);
+                        if (!prefixed)
+                                return log_oom();
+
+                        t = path_join("..", d);
+                        if (!t)
+                                return log_oom();
+
+                        if (symlink(t, prefixed) < 0)
+                                log_debug_errno(errno, "Failed to symlink '%s' to '%s': %m", t, prefixed);
+                }
+        }
+
+        return r;
+}
+
+static int make_extra_nodes(const char *dest) {
+        _cleanup_umask_ mode_t u;
+        size_t i;
+        int r;
+
+        u = umask(0000);
+
+        for (i = 0; i < arg_n_extra_nodes; i++) {
+                _cleanup_free_ char *path = NULL;
+                DeviceNode *n = arg_extra_nodes + i;
+
+                path = path_join(dest, n->path);
+                if (!path)
+                        return log_oom();
+
+                if (mknod(path, n->mode, S_ISCHR(n->mode) || S_ISBLK(n->mode) ? makedev(n->major, n->minor) : 0) < 0)
+                        return log_error_errno(errno, "Failed to create device node '%s': %m", path);
+
+                r = chmod_and_chown(path, n->mode, n->uid, n->gid);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to adjust device node ownership of '%s': %m", path);
+        }
+
+        return 0;
+}
+
+static int setup_pts(const char *dest) {
+        _cleanup_free_ char *options = NULL;
+        const char *p;
+        int r;
+
+#if 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");
+        r = mkdir_errno_wrapper(p, 0755);
+        if (r < 0)
+                return log_error_errno(r, "Failed to create /dev/pts: %m");
+
+        r = mount_nofollow_verbose(LOG_ERR, "devpts", p, "devpts", MS_NOSUID|MS_NOEXEC, options);
+        if (r < 0)
+                return r;
+        r = userns_lchown(p, 0, 0);
+        if (r < 0)
+                return log_error_errno(r, "Failed to chown /dev/pts: %m");
+
+        /* Create /dev/ptmx symlink */
+        p = prefix_roota(dest, "/dev/ptmx");
+        if (symlink("pts/ptmx", p) < 0)
+                return log_error_errno(errno, "Failed to create /dev/ptmx symlink: %m");
+        r = userns_lchown(p, 0, 0);
+        if (r < 0)
+                return log_error_errno(r, "Failed to chown /dev/ptmx: %m");
+
+        /* And fix /dev/pts/ptmx ownership */
+        p = prefix_roota(dest, "/dev/pts/ptmx");
+        r = userns_lchown(p, 0, 0);
+        if (r < 0)
+                return log_error_errno(r, "Failed to chown /dev/pts/ptmx: %m");
+
+        return 0;
+}
+
+static int setup_stdio_as_dev_console(void) {
+        _cleanup_close_ int terminal = -1;
+        int r;
+
+        /* We open the TTY in O_NOCTTY mode, so that we do not become controller yet. We'll do that later
+         * explicitly, if we are configured to. */
+        terminal = open_terminal("/dev/console", O_RDWR|O_NOCTTY);
+        if (terminal < 0)
+                return log_error_errno(terminal, "Failed to open console: %m");
+
+        /* Make sure we can continue logging to the original stderr, even if
+         * stderr points elsewhere now */
+        r = log_dup_console();
+        if (r < 0)
+                return log_error_errno(r, "Failed to duplicate stderr: %m");
+
+        /* invalidates 'terminal' on success and failure */
+        r = rearrange_stdio(terminal, terminal, terminal);
+        TAKE_FD(terminal);
+        if (r < 0)
+                return log_error_errno(r, "Failed to move console to stdin/stdout/stderr: %m");
+
+        return 0;
+}
+
+static int setup_dev_console(const char *console) {
+        _cleanup_free_ char *p = NULL;
+        int r;
+
+        /* Create /dev/console symlink */
+        r = path_make_relative("/dev", console, &p);
+        if (r < 0)
+                return log_error_errno(r, "Failed to create relative path: %m");
+
+        if (symlink(p, "/dev/console") < 0)
+                return log_error_errno(errno, "Failed to create /dev/console symlink: %m");
+
+        return 0;
+}
+
+static int setup_keyring(void) {
+        key_serial_t keyring;
+
+        /* Allocate a new session keyring for the container. This makes sure the keyring of the session
+         * systemd-nspawn was invoked from doesn't leak into the container. Note that by default we block
+         * keyctl() and request_key() anyway via seccomp so doing this operation isn't strictly necessary,
+         * but in case people explicitly allow-list these system calls let's make sure we don't leak anything
+         * into the container. */
+
+        keyring = keyctl(KEYCTL_JOIN_SESSION_KEYRING, 0, 0, 0, 0);
+        if (keyring == -1) {
+                if (errno == ENOSYS)
+                        log_debug_errno(errno, "Kernel keyring not supported, ignoring.");
+                else if (ERRNO_IS_PRIVILEGE(errno))
+                        log_debug_errno(errno, "Kernel keyring access prohibited, ignoring.");
+                else
+                        return log_error_errno(errno, "Setting up kernel keyring failed: %m");
+        }
+
+        return 0;
+}
+
+static int setup_credentials(const char *root) {
+        const char *q;
+        int r;
+
+        if (arg_n_credentials <= 0)
+                return 0;
+
+        r = userns_mkdir(root, "/run/host", 0755, 0, 0);
+        if (r < 0)
+                return log_error_errno(r, "Failed to create /run/host: %m");
+
+        r = userns_mkdir(root, "/run/host/credentials", 0700, 0, 0);
+        if (r < 0)
+                return log_error_errno(r, "Failed to create /run/host/credentials: %m");
+
+        q = prefix_roota(root, "/run/host/credentials");
+        r = mount_nofollow_verbose(LOG_ERR, NULL, q, "ramfs", MS_NOSUID|MS_NOEXEC|MS_NODEV, "mode=0700");
+        if (r < 0)
+                return r;
+
+        for (size_t i = 0; i < arg_n_credentials; i++) {
+                _cleanup_free_ char *j = NULL;
+                _cleanup_close_ int fd = -1;
+
+                j = path_join(q, arg_credentials[i].id);
+                if (!j)
+                        return log_oom();
+
+                fd = open(j, O_CREAT|O_EXCL|O_WRONLY|O_CLOEXEC|O_NOFOLLOW, 0600);
+                if (fd < 0)
+                        return log_error_errno(errno, "Failed to create credential file %s: %m", j);
+
+                r = loop_write(fd, arg_credentials[i].data, arg_credentials[i].size, /* do_poll= */ false);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to write credential to file %s: %m", j);
+
+                if (fchmod(fd, 0400) < 0)
+                        return log_error_errno(errno, "Failed to adjust access mode of %s: %m", j);
+
+                if (arg_userns_mode != USER_NAMESPACE_NO) {
+                        if (fchown(fd, arg_uid_shift, arg_uid_shift) < 0)
+                                return log_error_errno(errno, "Failed to adjust ownership of %s: %m", j);
+                }
+        }
+
+        if (chmod(q, 0500) < 0)
+                return log_error_errno(errno, "Failed to adjust access mode of %s: %m", q);
+
+        r = userns_lchown(q, 0, 0);
+        if (r < 0)
+                return r;
+
+        /* Make both mount and superblock read-only now */
+        r = mount_nofollow_verbose(LOG_ERR, NULL, q, NULL, MS_REMOUNT|MS_BIND|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV, NULL);
+        if (r < 0)
+                return r;
+
+        return mount_nofollow_verbose(LOG_ERR, NULL, q, NULL, MS_REMOUNT|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV, "mode=0500");
+}
+
+static int setup_kmsg(int kmsg_socket) {
+        _cleanup_(unlink_and_freep) char *from = NULL;
+        _cleanup_free_ char *fifo = NULL;
+        _cleanup_close_ int fd = -1;
+        _cleanup_umask_ mode_t u;
+        int r;
+
+        assert(kmsg_socket >= 0);
+
+        u = umask(0000);
+
+        /* We create the kmsg FIFO as as temporary file in /run, 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. */
+
+        r = tempfn_random_child("/run", "proc-kmsg", &fifo);
+        if (r < 0)
+                return log_error_errno(r, "Failed to generate kmsg path: %m");
+
+        if (mkfifo(fifo, 0600) < 0)
+                return log_error_errno(errno, "mkfifo() for /run/kmsg failed: %m");
+
+        from = TAKE_PTR(fifo);
+
+        r = mount_nofollow_verbose(LOG_ERR, from, "/proc/kmsg", NULL, MS_BIND, NULL);
+        if (r < 0)
+                return r;
+
+        fd = open(from, O_RDWR|O_NONBLOCK|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);
+        if (r < 0)
+                return log_error_errno(r, "Failed to send FIFO fd: %m");
+
+        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) {
+        int r;
+
+        if ((arg_clone_ns_flags & CLONE_NEWUTS) == 0)
+                return 0;
+
+        r = sethostname_idempotent(arg_hostname ?: arg_machine);
+        if (r < 0)
+                return log_error_errno(r, "Failed to set hostname: %m");
+
+        return 0;
+}
+
+static int setup_journal(const char *directory) {
+        _cleanup_free_ char *d = NULL;
+        char id[SD_ID128_STRING_MAX];
+        const char *dirname, *p, *q;
+        sd_id128_t this_id;
+        bool try;
+        int r;
+
+        /* Don't link journals in ephemeral mode */
+        if (arg_ephemeral)
+                return 0;
+
+        if (arg_link_journal == LINK_NO)
+                return 0;
+
+        try = arg_link_journal_try || arg_link_journal == LINK_AUTO;
+
+        r = sd_id128_get_machine(&this_id);
+        if (r < 0)
+                return log_error_errno(r, "Failed to retrieve machine ID: %m");
+
+        if (sd_id128_equal(arg_uuid, this_id)) {
+                log_full(try ? LOG_WARNING : LOG_ERR,
+                         "Host and machine ids are equal (%s): refusing to link journals", sd_id128_to_string(arg_uuid, id));
+                if (try)
+                        return 0;
+                return -EEXIST;
+        }
+
+        FOREACH_STRING(dirname, "/var", "/var/log", "/var/log/journal") {
+                r = userns_mkdir(directory, dirname, 0755, 0, 0);
+                if (r < 0) {
+                        bool ignore = r == -EROFS && try;
+                        log_full_errno(ignore ? LOG_DEBUG : LOG_ERR, r,
+                                       "Failed to create %s%s: %m", dirname, ignore ? ", ignoring" : "");
+                        return ignore ? 0 : r;
+                }
+        }
+
+        (void) sd_id128_to_string(arg_uuid, id);
+
+        p = strjoina("/var/log/journal/", id);
+        q = prefix_roota(directory, p);
+
+        if (path_is_mount_point(p, NULL, 0) > 0) {
+                if (try)
+                        return 0;
+
+                return log_error_errno(SYNTHETIC_ERRNO(EEXIST),
+                                       "%s: already a mount point, refusing to use for journal", p);
+        }
+
+        if (path_is_mount_point(q, NULL, 0) > 0) {
+                if (try)
+                        return 0;
+
+                return log_error_errno(SYNTHETIC_ERRNO(EEXIST),
+                                       "%s: already a mount point, refusing to use for journal", q);
+        }
+
+        r = readlink_and_make_absolute(p, &d);
+        if (r >= 0) {
+                if (IN_SET(arg_link_journal, LINK_GUEST, 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 */
+
+                r = mkdir_errno_wrapper(p, 0755);
+                if (r < 0 && r != -EEXIST) {
+                        if (try) {
+                                log_debug_errno(r, "Failed to create %s, skipping journal setup: %m", p);
+                                return 0;
+                        } else
+                                return log_error_errno(r, "Failed to create %s: %m", p);
+                }
+
+        } else if (access(p, F_OK) < 0)
+                return 0;
+
+        if (dir_is_empty(q) == 0)
+                log_warning("%s is not empty, proceeding anyway.", q);
+
+        r = userns_mkdir(directory, p, 0755, 0, 0);
+        if (r < 0)
+                return log_error_errno(r, "Failed to create %s: %m", q);
+
+        r = mount_nofollow_verbose(LOG_DEBUG, p, q, NULL, MS_BIND, NULL);
+        if (r < 0)
+                return log_error_errno(errno, "Failed to bind mount journal from host into guest: %m");
+
+        return 0;
+}
+
+static int drop_capabilities(uid_t uid) {
+        CapabilityQuintet q;
+
+        /* Let's initialize all five capability sets to something valid. If the quintet was configured via
+         * OCI use that, but fill in missing bits. If it wasn't then derive the quintet in full from
+         * arg_caps_retain. */
+
+        if (capability_quintet_is_set(&arg_full_capabilities)) {
+                q = arg_full_capabilities;
+
+                if (q.bounding == (uint64_t) -1)
+                        q.bounding = uid == 0 ? arg_caps_retain : 0;
+
+                if (q.effective == (uint64_t) -1)
+                        q.effective = uid == 0 ? q.bounding : 0;
+
+                if (q.inheritable == (uint64_t) -1)
+                        q.inheritable = uid == 0 ? q.bounding : 0;
+
+                if (q.permitted == (uint64_t) -1)
+                        q.permitted = uid == 0 ? q.bounding : 0;
+
+                if (q.ambient == (uint64_t) -1 && ambient_capabilities_supported())
+                        q.ambient = 0;
+
+                if (capability_quintet_mangle(&q))
+                        return log_error_errno(SYNTHETIC_ERRNO(EPERM), "Cannot set capabilities that are not in the current bounding set.");
+
+        } else {
+                q = (CapabilityQuintet) {
+                        .bounding = arg_caps_retain,
+                        .effective = uid == 0 ? arg_caps_retain : 0,
+                        .inheritable = uid == 0 ? arg_caps_retain : 0,
+                        .permitted = uid == 0 ? arg_caps_retain : 0,
+                        .ambient = ambient_capabilities_supported() ? 0 : (uint64_t) -1,
+                };
+
+                /* If we're not using OCI, proceed with mangled capabilities (so we don't error out)
+                 * in order to maintain the same behavior as systemd < 242. */
+                if (capability_quintet_mangle(&q))
+                        log_full(arg_quiet ? LOG_DEBUG : LOG_WARNING,
+                                 "Some capabilities will not be set because they are not in the current bounding set.");
+
+        }
+
+        return capability_quintet_enforce(&q);
+}
+
+static int reset_audit_loginuid(void) {
+        _cleanup_free_ char *p = NULL;
+        int r;
+
+        if ((arg_clone_ns_flags & CLONE_NEWPID) == 0)
+                return 0;
+
+        r = read_one_line_file("/proc/self/loginuid", &p);
+        if (r == -ENOENT)
+                return 0;
+        if (r < 0)
+                return log_error_errno(r, "Failed to read /proc/self/loginuid: %m");
+
+        /* Already reset? */
+        if (streq(p, "4294967295"))
+                return 0;
+
+        r = write_string_file("/proc/self/loginuid", "4294967295", WRITE_STRING_FILE_DISABLE_BUFFER);
+        if (r < 0) {
+                log_error_errno(r,
+                                "Failed to reset audit login UID. This probably means that your kernel is too\n"
+                                "old and you have audit enabled. Note that the auditing subsystem is known to\n"
+                                "be incompatible with containers on old kernels. Please make sure to upgrade\n"
+                                "your kernel or to off auditing with 'audit=0' on the kernel command line before\n"
+                                "using systemd-nspawn. Sleeping for 5s... (%m)");
+
+                sleep(5);
+        }
+
+        return 0;
+}
+
+static int setup_propagate(const char *root) {
+        const char *p, *q;
+        int r;
+
+        (void) mkdir_p("/run/systemd/nspawn/", 0755);
+        (void) mkdir_p("/run/systemd/nspawn/propagate", 0600);
+        p = strjoina("/run/systemd/nspawn/propagate/", arg_machine);
+        (void) mkdir_p(p, 0600);
+
+        r = userns_mkdir(root, "/run/host", 0755, 0, 0);
+        if (r < 0)
+                return log_error_errno(r, "Failed to create /run/host: %m");
+
+        r = userns_mkdir(root, "/run/host/incoming", 0600, 0, 0);
+        if (r < 0)
+                return log_error_errno(r, "Failed to create /run/host/incoming: %m");
+
+        q = prefix_roota(root, "/run/host/incoming");
+        r = mount_nofollow_verbose(LOG_ERR, p, q, NULL, MS_BIND, NULL);
+        if (r < 0)
+                return r;
+
+        r = mount_nofollow_verbose(LOG_ERR, NULL, q, NULL, MS_BIND|MS_REMOUNT|MS_RDONLY, NULL);
+        if (r < 0)
+                return r;
+
+        /* machined will MS_MOVE into that directory, and that's only supported for non-shared mounts. */
+        return mount_nofollow_verbose(LOG_ERR, NULL, q, NULL, MS_SLAVE, NULL);
+}
+
+static int setup_machine_id(const char *directory) {
+        const char *etc_machine_id;
+        sd_id128_t id;
+        int r;
+
+        /* If the UUID in the container is already set, then that's what counts, and we use. If it isn't set, and the
+         * caller passed --uuid=, then we'll pass it in the $container_uuid env var to PID 1 of the container. The
+         * assumption is that PID 1 will then write it to /etc/machine-id to make it persistent. If --uuid= is not
+         * passed we generate a random UUID, and pass it via $container_uuid. In effect this means that /etc/machine-id
+         * in the container and our idea of the container UUID will always be in sync (at least if PID 1 in the
+         * container behaves nicely). */
+
+        etc_machine_id = prefix_roota(directory, "/etc/machine-id");
+
+        r = id128_read(etc_machine_id, ID128_PLAIN_OR_UNINIT, &id);
+        if (r < 0) {
+                if (!IN_SET(r, -ENOENT, -ENOMEDIUM)) /* If the file is missing or empty, we don't mind */
+                        return log_error_errno(r, "Failed to read machine ID from container image: %m");
+
+                if (sd_id128_is_null(arg_uuid)) {
+                        r = sd_id128_randomize(&arg_uuid);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to acquire randomized machine UUID: %m");
+                }
+        } else {
+                if (sd_id128_is_null(id))
+                        return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                               "Machine ID in container image is zero, refusing.");
+
+                arg_uuid = id;
+        }
+
+        return 0;
+}
+
+static int recursive_chown(const char *directory, uid_t shift, uid_t range) {
+        int r;
+
+        assert(directory);
+
+        if (arg_userns_mode == USER_NAMESPACE_NO || !arg_userns_chown)
+                return 0;
+
+        r = path_patch_uid(directory, arg_uid_shift, arg_uid_range);
+        if (r == -EOPNOTSUPP)
+                return log_error_errno(r, "Automatic UID/GID adjusting is only supported for UID/GID ranges starting at multiples of 2^16 with a range of 2^16.");
+        if (r == -EBADE)
+                return log_error_errno(r, "Upper 16 bits of root directory UID and GID do not match.");
+        if (r < 0)
+                return log_error_errno(r, "Failed to adjust UID/GID shift of OS tree: %m");
+        if (r == 0)
+                log_debug("Root directory of image is already owned by the right UID/GID range, skipping recursive chown operation.");
+        else
+                log_debug("Patched directory tree to match UID/GID range.");
+
+        return r;
+}
+
+/*
+ * 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;
+                }
+
+                _fallthrough_;
+        case CLD_DUMPED:
+                return log_error_errno(SYNTHETIC_ERRNO(EIO),
+                                       "Container %s terminated by signal %s.", arg_machine, signal_to_string(status.si_status));
+
+        default:
+                return log_error_errno(SYNTHETIC_ERRNO(EIO),
+                                       "Container %s failed due to unknown reason.", arg_machine);
+        }
+}
+
+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 on_sigchld(sd_event_source *s, const struct signalfd_siginfo *ssi, void *userdata) {
+        pid_t pid;
+
+        assert(s);
+        assert(ssi);
+
+        pid = PTR_TO_PID(userdata);
+
+        for (;;) {
+                siginfo_t si = {};
+
+                if (waitid(P_ALL, 0, &si, WNOHANG|WNOWAIT|WEXITED) < 0)
+                        return log_error_errno(errno, "Failed to waitid(): %m");
+                if (si.si_pid == 0) /* No pending children. */
+                        break;
+                if (si.si_pid == pid) {
+                        /* The main process we care for has exited. Return from
+                         * signal handler but leave the zombie. */
+                        sd_event_exit(sd_event_source_get_event(s), 0);
+                        break;
+                }
+
+                /* Reap all other children. */
+                (void) waitid(P_PID, si.si_pid, &si, WNOHANG|WEXITED);
+        }
+
+        return 0;
+}
+
+static int on_request_stop(sd_bus_message *m, void *userdata, sd_bus_error *error) {
+        pid_t pid;
+
+        assert(m);
+
+        pid = PTR_TO_PID(userdata);
+
+        if (arg_kill_signal > 0) {
+                log_info("Container termination requested. Attempting to halt container.");
+                (void) kill(pid, arg_kill_signal);
+        } else {
+                log_info("Container termination requested. Exiting.");
+                sd_event_exit(sd_bus_get_event(sd_bus_message_get_bus(m)), 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 = path_join("/var/lib/machines", arg_machine);
+                if (!arg_directory)
+                        return log_oom();
+        }
+
+        if (!arg_image && !arg_directory) {
+                if (arg_machine) {
+                        _cleanup_(image_unrefp) Image *i = NULL;
+
+                        r = image_find(IMAGE_MACHINE, arg_machine, &i);
+                        if (r == -ENOENT)
+                                return log_error_errno(r, "No image for machine '%s'.", arg_machine);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to find image for machine '%s': %m", arg_machine);
+
+                        if (IN_SET(i->type, IMAGE_RAW, IMAGE_BLOCK))
+                                r = free_and_strdup(&arg_image, i->path);
+                        else
+                                r = free_and_strdup(&arg_directory, i->path);
+                        if (r < 0)
+                                return log_oom();
+
+                        if (!arg_ephemeral)
+                                arg_read_only = arg_read_only || i->read_only;
+                } else {
+                        r = safe_getcwd(&arg_directory);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to determine current directory: %m");
+                }
+
+                if (!arg_directory && !arg_image)
+                        return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to determine path, please use -D or -i.");
+        }
+
+        if (!arg_machine) {
+                if (arg_directory && path_equal(arg_directory, "/"))
+                        arg_machine = gethostname_malloc();
+                else {
+                        if (arg_image) {
+                                char *e;
+
+                                arg_machine = strdup(basename(arg_image));
+
+                                /* Truncate suffix if there is one */
+                                e = endswith(arg_machine, ".raw");
+                                if (e)
+                                        *e = 0;
+                        } else
+                                arg_machine = strdup(basename(arg_directory));
+                }
+                if (!arg_machine)
+                        return log_oom();
+
+                hostname_cleanup(arg_machine);
+                if (!machine_name_is_valid(arg_machine))
+                        return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to determine machine name automatically, please use -M.");
+
+                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 chase_symlinks_and_update(char **p, unsigned flags) {
+        char *chased;
+        int r;
+
+        assert(p);
+
+        if (!*p)
+                return 0;
+
+        r = chase_symlinks(*p, NULL, flags, &chased, NULL);
+        if (r < 0)
+                return log_error_errno(r, "Failed to resolve path %s: %m", *p);
+
+        return free_and_replace(*p, chased);
+}
+
+static int determine_uid_shift(const char *directory) {
+        int r;
+
+        if (arg_userns_mode == USER_NAMESPACE_NO) {
+                arg_uid_shift = 0;
+                return 0;
+        }
+
+        if (arg_uid_shift == UID_INVALID) {
+                struct stat st;
+
+                r = stat(directory, &st);
+                if (r < 0)
+                        return log_error_errno(errno, "Failed to determine UID base of %s: %m", directory);
+
+                arg_uid_shift = st.st_uid & UINT32_C(0xffff0000);
+
+                if (arg_uid_shift != (st.st_gid & UINT32_C(0xffff0000)))
+                        return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                               "UID and GID base of %s don't match.", directory);
+
+                arg_uid_range = UINT32_C(0x10000);
+        }
+
+        if (arg_uid_shift > (uid_t) -1 - arg_uid_range)
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                       "UID base too high for UID range.");
+
+        return 0;
+}
+
+static unsigned long effective_clone_ns_flags(void) {
+        unsigned long flags = arg_clone_ns_flags;
+
+        if (arg_private_network)
+                flags |= CLONE_NEWNET;
+        if (arg_use_cgns)
+                flags |= CLONE_NEWCGROUP;
+        if (arg_userns_mode != USER_NAMESPACE_NO)
+                flags |= CLONE_NEWUSER;
+
+        return flags;
+}
+
+static int patch_sysctl(void) {
+
+        /* This table is inspired by runc's sysctl() function */
+        static const struct {
+                const char *key;
+                bool prefix;
+                unsigned long clone_flags;
+        } safe_sysctl[] = {
+                { "kernel.hostname",   false, CLONE_NEWUTS },
+                { "kernel.domainname", false, CLONE_NEWUTS },
+                { "kernel.msgmax",     false, CLONE_NEWIPC },
+                { "kernel.msgmnb",     false, CLONE_NEWIPC },
+                { "kernel.msgmni",     false, CLONE_NEWIPC },
+                { "kernel.sem",        false, CLONE_NEWIPC },
+                { "kernel.shmall",     false, CLONE_NEWIPC },
+                { "kernel.shmmax",     false, CLONE_NEWIPC },
+                { "kernel.shmmni",     false, CLONE_NEWIPC },
+                { "fs.mqueue.",        true,  CLONE_NEWIPC },
+                { "net.",              true,  CLONE_NEWNET },
+        };
+
+        unsigned long flags;
+        char **k, **v;
+        int r;
+
+        flags = effective_clone_ns_flags();
+
+        STRV_FOREACH_PAIR(k, v, arg_sysctl) {
+                bool good = false;
+                size_t i;
+
+                for (i = 0; i < ELEMENTSOF(safe_sysctl); i++) {
+
+                        if (!FLAGS_SET(flags, safe_sysctl[i].clone_flags))
+                                continue;
+
+                        if (safe_sysctl[i].prefix)
+                                good = startswith(*k, safe_sysctl[i].key);
+                        else
+                                good = streq(*k, safe_sysctl[i].key);
+
+                        if (good)
+                                break;
+                }
+
+                if (!good)
+                        return log_error_errno(SYNTHETIC_ERRNO(EPERM), "Refusing to write to sysctl '%s', as it is not safe in the selected namespaces.", *k);
+
+                r = sysctl_write(*k, *v);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to write sysctl '%s': %m", *k);
+        }
+
+        return 0;
+}
+
+static int inner_child(
+                Barrier *barrier,
+                const char *directory,
+                bool secondary,
+                int kmsg_socket,
+                int rtnl_socket,
+                int master_pty_socket,
+                FDSet *fds,
+                char **os_release_pairs) {
+
+        _cleanup_free_ char *home = NULL;
+        char as_uuid[ID128_UUID_STRING_MAX];
+        size_t n_env = 1;
+        const char *envp[] = {
+                "PATH=" DEFAULT_PATH_COMPAT,
+                NULL, /* container */
+                NULL, /* TERM */
+                NULL, /* HOME */
+                NULL, /* USER */
+                NULL, /* LOGNAME */
+                NULL, /* container_uuid */
+                NULL, /* LISTEN_FDS */
+                NULL, /* LISTEN_PID */
+                NULL, /* NOTIFY_SOCKET */
+                NULL, /* CREDENTIALS_DIRECTORY */
+                NULL
+        };
+        const char *exec_target;
+        _cleanup_strv_free_ char **env_use = NULL;
+        int r, which_failed;
+
+        /* This is the "inner" child process, i.e. the one forked off by the "outer" child process, which is the one
+         * the container manager itself forked off. At the time of clone() it gained its own CLONE_NEWNS, CLONE_NEWPID,
+         * CLONE_NEWUTS, CLONE_NEWIPC, CLONE_NEWUSER namespaces. Note that it has its own CLONE_NEWNS namespace,
+         * separate from the CLONE_NEWNS created for the "outer" child, and also separate from the host's CLONE_NEWNS
+         * namespace. The reason for having two levels of CLONE_NEWNS namespaces is that the "inner" one is owned by
+         * the CLONE_NEWUSER namespace of the container, while the "outer" one is owned by the host's CLONE_NEWUSER
+         * namespace.
+         *
+         * Note at this point we have no CLONE_NEWNET namespace yet. We'll acquire that one later through
+         * unshare(). See below. */
+
+        assert(barrier);
+        assert(directory);
+        assert(kmsg_socket >= 0);
+
+        log_debug("Inner child is initializing.");
+
+        if (arg_userns_mode != USER_NAMESPACE_NO) {
+                /* Tell the parent, that it now can write the UID map. */
+                (void) barrier_place(barrier); /* #1 */
+
+                /* Wait until the parent wrote the UID map */
+                if (!barrier_place_and_sync(barrier)) /* #2 */
+                        return log_error_errno(SYNTHETIC_ERRNO(ESRCH), "Parent died too early");
+
+                /* Become the new root user inside our namespace */
+                r = reset_uid_gid();
+                if (r < 0)
+                        return log_error_errno(r, "Couldn't become new root: %m");
+
+                /* Creating a new user namespace means all MS_SHARED mounts become MS_SLAVE. Let's put them
+                 * back to MS_SHARED here, since that's what we want as defaults. (This will not reconnect
+                 * propagation, but simply create new peer groups for all our mounts). */
+                r = mount_follow_verbose(LOG_ERR, NULL, "/", NULL, MS_SHARED|MS_REC, NULL);
+                if (r < 0)
+                        return r;
+        }
+
+        r = mount_all(NULL,
+                      arg_mount_settings | MOUNT_IN_USERNS,
+                      arg_uid_shift,
+                      arg_selinux_apifs_context);
+        if (r < 0)
+                return r;
+
+        if (!arg_network_namespace_path && arg_private_network) {
+                r = unshare(CLONE_NEWNET);
+                if (r < 0)
+                        return log_error_errno(errno, "Failed to unshare network namespace: %m");
+
+                /* Tell the parent that it can setup network interfaces. */
+                (void) barrier_place(barrier); /* #3 */
+        }
+
+        r = mount_sysfs(NULL, arg_mount_settings);
+        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)) /* #4 */
+                return log_error_errno(SYNTHETIC_ERRNO(ESRCH),
+                                       "Parent died too early");
+
+        if (arg_use_cgns) {
+                r = unshare(CLONE_NEWCGROUP);
+                if (r < 0)
+                        return log_error_errno(errno, "Failed to unshare cgroup namespace: %m");
+                r = mount_cgroups(
+                                "",
+                                arg_unified_cgroup_hierarchy,
+                                arg_userns_mode != USER_NAMESPACE_NO,
+                                arg_uid_shift,
+                                arg_uid_range,
+                                arg_selinux_apifs_context,
+                                true);
+        } else
+                r = mount_systemd_cgroup_writable("", arg_unified_cgroup_hierarchy);
+        if (r < 0)
+                return r;
+
+        r = setup_boot_id();
+        if (r < 0)
+                return r;
+
+        r = setup_kmsg(kmsg_socket);
+        if (r < 0)
+                return r;
+        kmsg_socket = safe_close(kmsg_socket);
+
+        r = mount_custom(
+                        "/",
+                        arg_custom_mounts,
+                        arg_n_custom_mounts,
+                        0,
+                        arg_selinux_apifs_context,
+                        MOUNT_NON_ROOT_ONLY | MOUNT_IN_USERNS);
+        if (r < 0)
+                return r;
+
+        if (setsid() < 0)
+                return log_error_errno(errno, "setsid() failed: %m");
+
+        if (arg_private_network)
+                (void) loopback_setup();
+
+        if (arg_expose_ports) {
+                r = expose_port_send_rtnl(rtnl_socket);
+                if (r < 0)
+                        return r;
+                rtnl_socket = safe_close(rtnl_socket);
+        }
+
+        if (arg_console_mode != CONSOLE_PIPE) {
+                _cleanup_close_ int master = -1;
+                _cleanup_free_ char *console = NULL;
+
+                /* Allocate a pty and make it available as /dev/console. */
+                master = openpt_allocate(O_RDWR|O_NONBLOCK, &console);
+                if (master < 0)
+                        return log_error_errno(master, "Failed to allocate a pty: %m");
+
+                r = setup_dev_console(console);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to set up /dev/console: %m");
+
+                r = send_one_fd(master_pty_socket, master, 0);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to send master fd: %m");
+                master_pty_socket = safe_close(master_pty_socket);
+
+                r = setup_stdio_as_dev_console();
+                if (r < 0)
+                        return r;
+        }
+
+        r = patch_sysctl();
+        if (r < 0)
+                return r;
+
+        if (arg_oom_score_adjust_set) {
+                r = set_oom_score_adjust(arg_oom_score_adjust);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to adjust OOM score: %m");
+        }
+
+        if (arg_cpu_set.set)
+                if (sched_setaffinity(0, arg_cpu_set.allocated, arg_cpu_set.set) < 0)
+                        return log_error_errno(errno, "Failed to set CPU affinity: %m");
+
+        (void) setup_hostname();
+
+        if (arg_personality != PERSONALITY_INVALID) {
+                r = safe_personality(arg_personality);
+                if (r < 0)
+                        return log_error_errno(r, "personality() failed: %m");
+        } else if (secondary) {
+                r = safe_personality(PER_LINUX32);
+                if (r < 0)
+                        return log_error_errno(r, "personality() failed: %m");
+        }
+
+        r = setrlimit_closest_all((const struct rlimit *const*) arg_rlimit, &which_failed);
+        if (r < 0)
+                return log_error_errno(r, "Failed to apply resource limit RLIMIT_%s: %m", rlimit_to_string(which_failed));
+
+#if HAVE_SECCOMP
+        if (arg_seccomp) {
+
+                if (is_seccomp_available()) {
+
+                        r = seccomp_load(arg_seccomp);
+                        if (ERRNO_IS_SECCOMP_FATAL(r))
+                                return log_error_errno(r, "Failed to install seccomp filter: %m");
+                        if (r < 0)
+                                log_debug_errno(r, "Failed to install seccomp filter: %m");
+                }
+        } else
+#endif
+        {
+                r = setup_seccomp(arg_caps_retain, arg_syscall_allow_list, arg_syscall_deny_list);
+                if (r < 0)
+                        return r;
+        }
+
+#if HAVE_SELINUX
+        if (arg_selinux_context)
+                if (setexeccon(arg_selinux_context) < 0)
+                        return log_error_errno(errno, "setexeccon(\"%s\") failed: %m", arg_selinux_context);
+#endif
+
+        /* Make sure we keep the caps across the uid/gid dropping, so that we can retain some selected caps
+         * if we need to later on. */
+        if (prctl(PR_SET_KEEPCAPS, 1) < 0)
+                return log_error_errno(errno, "Failed to set PR_SET_KEEPCAPS: %m");
+
+        if (uid_is_valid(arg_uid) || gid_is_valid(arg_gid))
+                r = change_uid_gid_raw(arg_uid, arg_gid, arg_supplementary_gids, arg_n_supplementary_gids, arg_console_mode != CONSOLE_PIPE);
+        else
+                r = change_uid_gid(arg_user, arg_console_mode != CONSOLE_PIPE, &home);
+        if (r < 0)
+                return r;
+
+        r = drop_capabilities(getuid());
+        if (r < 0)
+                return log_error_errno(r, "Dropping capabilities failed: %m");
+
+        if (arg_no_new_privileges)
+                if (prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0) < 0)
+                        return log_error_errno(errno, "Failed to disable new privileges: %m");
+
+        /* 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 (home || !uid_is_valid(arg_uid) || arg_uid == 0)
+                if (asprintf((char**)(envp + n_env++), "HOME=%s", home ?: "/root") < 0)
+                        return log_oom();
+
+        if (arg_user || !uid_is_valid(arg_uid) || arg_uid == 0)
+                if (asprintf((char**)(envp + n_env++), "USER=%s", arg_user ?: "root") < 0 ||
+                    asprintf((char**)(envp + n_env++), "LOGNAME=%s", arg_user ? arg_user : "root") < 0)
+                        return log_oom();
+
+        assert(!sd_id128_is_null(arg_uuid));
+
+        if (asprintf((char**)(envp + n_env++), "container_uuid=%s", id128_to_uuid_string(arg_uuid, as_uuid)) < 0)
+                return log_oom();
+
+        if (fdset_size(fds) > 0) {
+                r = fdset_cloexec(fds, false);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to unset O_CLOEXEC for file descriptors.");
+
+                if ((asprintf((char **)(envp + n_env++), "LISTEN_FDS=%u", fdset_size(fds)) < 0) ||
+                    (asprintf((char **)(envp + n_env++), "LISTEN_PID=1") < 0))
+                        return log_oom();
+        }
+        if (asprintf((char **)(envp + n_env++), "NOTIFY_SOCKET=%s", NSPAWN_NOTIFY_SOCKET_PATH) < 0)
+                return log_oom();
+
+        if (arg_n_credentials > 0) {
+                envp[n_env] = strdup("CREDENTIALS_DIRECTORY=/run/host/credentials");
+                if (!envp[n_env])
+                        return log_oom();
+                n_env++;
+        }
+
+        env_use = strv_env_merge(3, envp, os_release_pairs, 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)) /* #5 */
+                return log_error_errno(SYNTHETIC_ERRNO(ESRCH), "Parent died too early");
+
+        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(arg_uuid);
+                if (r < 0)
+                        return r;
+        }
+
+        if (arg_console_mode != CONSOLE_PIPE) {
+                /* So far our pty wasn't controlled by any process. Finally, it's time to change that, if we
+                 * are configured for that. Acquire it as controlling tty. */
+                if (ioctl(STDIN_FILENO, TIOCSCTTY) < 0)
+                        return log_error_errno(errno, "Failed to acquire controlling TTY: %m");
+        }
+
+        log_debug("Inner child completed, invoking payload.");
+
+        /* 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();
+        log_set_open_when_needed(true);
+
+        (void) fdset_close_others(fds);
+
+        if (arg_start_mode == START_BOOT) {
+                char **a;
+                size_t m;
+
+                /* Automatically search for the init system */
+
+                m = strv_length(arg_parameters);
+                a = newa(char*, m + 2);
+                memcpy_safe(a + 1, arg_parameters, m * sizeof(char*));
+                a[1 + m] = NULL;
+
+                a[0] = (char*) "/usr/lib/systemd/systemd";
+                execve(a[0], a, env_use);
+
+                a[0] = (char*) "/lib/systemd/systemd";
+                execve(a[0], a, env_use);
+
+                a[0] = (char*) "/sbin/init";
+                execve(a[0], a, env_use);
+
+                exec_target = "/usr/lib/systemd/systemd, /lib/systemd/systemd, /sbin/init";
+        } else if (!strv_isempty(arg_parameters)) {
+                const char *dollar_path;
+
+                exec_target = arg_parameters[0];
+
+                /* Use the user supplied search $PATH if there is one, or DEFAULT_PATH_COMPAT if not to search the
+                 * binary. */
+                dollar_path = strv_env_get(env_use, "PATH");
+                if (dollar_path) {
+                        if (setenv("PATH", dollar_path, 1) < 0)
+                                return log_error_errno(errno, "Failed to update $PATH: %m");
+                }
+
+                execvpe(arg_parameters[0], arg_parameters, env_use);
+        } else {
+                if (!arg_chdir)
+                        /* If we cannot change the directory, we'll end up in /, that is expected. */
+                        (void) chdir(home ?: "/root");
+
+                execle("/bin/bash", "-bash", NULL, env_use);
+                execle("/bin/sh", "-sh", NULL, env_use);
+
+                exec_target = "/bin/bash, /bin/sh";
+        }
+
+        return log_error_errno(errno, "execv(%s) failed: %m", exec_target);
+}
+
+static int setup_notify_child(void) {
+        _cleanup_close_ int fd = -1;
+        union sockaddr_union sa = {
+                .un.sun_family = AF_UNIX,
+                .un.sun_path = NSPAWN_NOTIFY_SOCKET_PATH,
+        };
+        int r;
+
+        fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
+        if (fd < 0)
+                return log_error_errno(errno, "Failed to allocate notification socket: %m");
+
+        (void) mkdir_parents(NSPAWN_NOTIFY_SOCKET_PATH, 0755);
+        (void) sockaddr_un_unlink(&sa.un);
+
+        r = bind(fd, &sa.sa, SOCKADDR_UN_LEN(sa.un));
+        if (r < 0)
+                return log_error_errno(errno, "bind(" NSPAWN_NOTIFY_SOCKET_PATH ") failed: %m");
+
+        r = userns_lchown(NSPAWN_NOTIFY_SOCKET_PATH, 0, 0);
+        if (r < 0)
+                return log_error_errno(r, "Failed to chown " NSPAWN_NOTIFY_SOCKET_PATH ": %m");
+
+        r = setsockopt_int(fd, SOL_SOCKET, SO_PASSCRED, true);
+        if (r < 0)
+                return log_error_errno(r, "SO_PASSCRED failed: %m");
+
+        return TAKE_FD(fd);
+}
+
+static int outer_child(
+                Barrier *barrier,
+                const char *directory,
+                DissectedImage *dissected_image,
+                bool secondary,
+                int pid_socket,
+                int uuid_socket,
+                int notify_socket,
+                int kmsg_socket,
+                int rtnl_socket,
+                int uid_shift_socket,
+                int master_pty_socket,
+                int unified_cgroup_hierarchy_socket,
+                FDSet *fds,
+                int netns_fd) {
+
+        _cleanup_strv_free_ char **os_release_pairs = NULL;
+        _cleanup_close_ int fd = -1;
+        const char *p;
+        pid_t pid;
+        ssize_t l;
+        int r;
+
+        /* This is the "outer" child process, i.e the one forked off by the container manager itself. It already has
+         * its own CLONE_NEWNS namespace (which was created by the clone()). It still lives in the host's CLONE_NEWPID,
+         * CLONE_NEWUTS, CLONE_NEWIPC, CLONE_NEWUSER and CLONE_NEWNET namespaces. After it completed a number of
+         * initializations a second child (the "inner" one) is forked off it, and it exits. */
+
+        assert(barrier);
+        assert(directory);
+        assert(pid_socket >= 0);
+        assert(uuid_socket >= 0);
+        assert(notify_socket >= 0);
+        assert(master_pty_socket >= 0);
+        assert(kmsg_socket >= 0);
+
+        log_debug("Outer child is initializing.");
+
+        r = load_os_release_pairs_with_prefix("/", "container_host_", &os_release_pairs);
+        if (r < 0)
+                log_debug_errno(r, "Failed to read os-release from host for container, ignoring: %m");
+
+        if (prctl(PR_SET_PDEATHSIG, SIGKILL) < 0)
+                return log_error_errno(errno, "PR_SET_PDEATHSIG failed: %m");
+
+        r = reset_audit_loginuid();
+        if (r < 0)
+                return r;
+
+        /* Mark everything as slave, so that we still receive mounts from the real root, but don't propagate
+         * mounts to the real root. */
+        r = mount_follow_verbose(LOG_ERR, NULL, "/", NULL, MS_SLAVE|MS_REC, NULL);
+        if (r < 0)
+                return r;
+
+        if (dissected_image) {
+                /* If we are operating on a disk image, then mount its root directory now, but leave out the rest. We
+                 * can read the UID shift from it if we need to. Further down we'll mount the rest, but then with the
+                 * uid shift known. That way we can mount VFAT file systems shifted to the right place right away. This
+                 * makes sure ESP partitions and userns are compatible. */
+
+                r = dissected_image_mount_and_warn(
+                                dissected_image, directory, arg_uid_shift,
+                                DISSECT_IMAGE_MOUNT_ROOT_ONLY|DISSECT_IMAGE_DISCARD_ON_LOOP|
+                                (arg_read_only ? DISSECT_IMAGE_READ_ONLY : DISSECT_IMAGE_FSCK)|
+                                (arg_start_mode == START_BOOT ? DISSECT_IMAGE_VALIDATE_OS : 0));
+                if (r < 0)
+                        return r;
+        }
+
+        r = determine_uid_shift(directory);
+        if (r < 0)
+                return r;
+
+        if (arg_userns_mode != USER_NAMESPACE_NO) {
+                /* Let the parent know which UID shift we read from the image */
+                l = send(uid_shift_socket, &arg_uid_shift, sizeof(arg_uid_shift), MSG_NOSIGNAL);
+                if (l < 0)
+                        return log_error_errno(errno, "Failed to send UID shift: %m");
+                if (l != sizeof(arg_uid_shift))
+                        return log_error_errno(SYNTHETIC_ERRNO(EIO),
+                                               "Short write while sending UID shift.");
+
+                if (arg_userns_mode == USER_NAMESPACE_PICK) {
+                        /* When we are supposed to pick the UID shift, the parent will check now whether the UID shift
+                         * we just read from the image is available. If yes, it will send the UID shift back to us, if
+                         * not it will pick a different one, and send it back to us. */
+
+                        l = recv(uid_shift_socket, &arg_uid_shift, sizeof(arg_uid_shift), 0);
+                        if (l < 0)
+                                return log_error_errno(errno, "Failed to recv UID shift: %m");
+                        if (l != sizeof(arg_uid_shift))
+                                return log_error_errno(SYNTHETIC_ERRNO(EIO),
+                                                       "Short read while receiving UID shift.");
+                }
+
+                log_full(arg_quiet ? LOG_DEBUG : LOG_INFO,
+                         "Selected user namespace base " UID_FMT " and range " UID_FMT ".", arg_uid_shift, arg_uid_range);
+        }
+
+        if (path_equal(directory, "/")) {
+                /* If the directory we shall boot is the host, let's operate on a bind mount at a different
+                 * place, so that we can make changes to its mount structure (for example, to implement
+                 * --volatile=) without this interfering with our ability to access files such as
+                 * /etc/localtime to copy into the container. Note that we use a fixed place for this
+                 * (instead of a temporary directory, since we are living in our own mount namspace here
+                 * already, and thus don't need to be afraid of colliding with anyone else's mounts).*/
+                (void) mkdir_p("/run/systemd/nspawn-root", 0755);
+
+                r = mount_nofollow_verbose(LOG_ERR, "/", "/run/systemd/nspawn-root", NULL, MS_BIND|MS_REC, NULL);
+                if (r < 0)
+                        return r;
+
+                directory = "/run/systemd/nspawn-root";
+        }
+
+        r = setup_pivot_root(
+                        directory,
+                        arg_pivot_root_new,
+                        arg_pivot_root_old);
+        if (r < 0)
+                return r;
+
+        r = setup_volatile_mode(
+                        directory,
+                        arg_volatile_mode,
+                        arg_uid_shift,
+                        arg_selinux_apifs_context);
+        if (r < 0)
+                return r;
+
+        r = mount_custom(
+                        directory,
+                        arg_custom_mounts,
+                        arg_n_custom_mounts,
+                        arg_uid_shift,
+                        arg_selinux_apifs_context,
+                        MOUNT_ROOT_ONLY);
+        if (r < 0)
+                return r;
+
+        /* Make sure we always have a mount that we can move to root later on. */
+        if (!path_is_mount_point(directory, NULL, 0)) {
+                r = mount_nofollow_verbose(LOG_ERR, directory, directory, NULL, MS_BIND|MS_REC, NULL);
+                if (r < 0)
+                        return r;
+        }
+
+        if (dissected_image) {
+                /* Now we know the uid shift, let's now mount everything else that might be in the image. */
+                r = dissected_image_mount(dissected_image, directory, arg_uid_shift,
+                                          DISSECT_IMAGE_MOUNT_NON_ROOT_ONLY|DISSECT_IMAGE_DISCARD_ON_LOOP|(arg_read_only ? DISSECT_IMAGE_READ_ONLY : DISSECT_IMAGE_FSCK));
+                if (r == -EUCLEAN)
+                        return log_error_errno(r, "File system check for image failed: %m");
+                if (r < 0)
+                        return log_error_errno(r, "Failed to mount image file system: %m");
+        }
+
+        if (arg_unified_cgroup_hierarchy == CGROUP_UNIFIED_UNKNOWN) {
+                /* OK, we don't know yet which cgroup mode to use yet. Let's figure it out, and tell the parent. */
+
+                r = detect_unified_cgroup_hierarchy_from_image(directory);
+                if (r < 0)
+                        return r;
+
+                l = send(unified_cgroup_hierarchy_socket, &arg_unified_cgroup_hierarchy, sizeof(arg_unified_cgroup_hierarchy), MSG_NOSIGNAL);
+                if (l < 0)
+                        return log_error_errno(errno, "Failed to send cgroup mode: %m");
+                if (l != sizeof(arg_unified_cgroup_hierarchy))
+                        return log_error_errno(SYNTHETIC_ERRNO(EIO),
+                                               "Short write while sending cgroup mode.");
+
+                unified_cgroup_hierarchy_socket = safe_close(unified_cgroup_hierarchy_socket);
+        }
+
+        /* Mark everything as shared so our mounts get propagated down. This is
+         * required to make new bind mounts available in systemd services
+         * inside the container that create a new mount namespace.
+         * See https://github.com/systemd/systemd/issues/3860
+         * Further submounts (such as /dev) done after this will inherit the
+         * shared propagation mode.
+         *
+         * IMPORTANT: Do not overmount the root directory anymore from now on to
+         * enable moving the root directory mount to root later on.
+         * https://github.com/systemd/systemd/issues/3847#issuecomment-562735251
+         */
+        r = mount_nofollow_verbose(LOG_ERR, NULL, directory, NULL, MS_SHARED|MS_REC, NULL);
+        if (r < 0)
+                return r;
+
+        r = recursive_chown(directory, arg_uid_shift, arg_uid_range);
+        if (r < 0)
+                return r;
+
+        r = base_filesystem_create(directory, arg_uid_shift, (gid_t) arg_uid_shift);
+        if (r < 0)
+                return r;
+
+        if (arg_read_only && arg_volatile_mode == VOLATILE_NO &&
+                !has_custom_root_mount(arg_custom_mounts, arg_n_custom_mounts)) {
+                r = bind_remount_recursive(directory, MS_RDONLY, MS_RDONLY, NULL);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to make tree read-only: %m");
+        }
+
+        r = mount_all(directory,
+                      arg_mount_settings,
+                      arg_uid_shift,
+                      arg_selinux_apifs_context);
+        if (r < 0)
+                return r;
+
+        r = copy_devnodes(directory);
+        if (r < 0)
+                return r;
+
+        r = make_extra_nodes(directory);
+        if (r < 0)
+                return r;
+
+        (void) dev_setup(directory, arg_uid_shift, arg_uid_shift);
+
+        p = prefix_roota(directory, "/run/host");
+        (void) make_inaccessible_nodes(p, 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_keyring();
+        if (r < 0)
+                return r;
+
+        r = setup_credentials(directory);
+        if (r < 0)
+                return r;
+
+        r = mount_custom(
+                        directory,
+                        arg_custom_mounts,
+                        arg_n_custom_mounts,
+                        arg_uid_shift,
+                        arg_selinux_apifs_context,
+                        MOUNT_NON_ROOT_ONLY);
+        if (r < 0)
+                return r;
+
+        r = setup_timezone(directory);
+        if (r < 0)
+                return r;
+
+        r = setup_resolv_conf(directory);
+        if (r < 0)
+                return r;
+
+        r = setup_machine_id(directory);
+        if (r < 0)
+                return r;
+
+        r = setup_journal(directory);
+        if (r < 0)
+                return r;
+
+        /* The same stuff as the $container env var, but nicely readable for the entire payload */
+        p = prefix_roota(directory, "/run/host/container-manager");
+        (void) write_string_file(p, arg_container_service_name, WRITE_STRING_FILE_CREATE);
+
+        /* The same stuff as the $container_uuid env var */
+        p = prefix_roota(directory, "/run/host/container-uuid");
+        (void) write_string_filef(p, WRITE_STRING_FILE_CREATE, SD_ID128_UUID_FORMAT_STR, SD_ID128_FORMAT_VAL(arg_uuid));
+
+        if (!arg_use_cgns) {
+                r = mount_cgroups(
+                                directory,
+                                arg_unified_cgroup_hierarchy,
+                                arg_userns_mode != USER_NAMESPACE_NO,
+                                arg_uid_shift,
+                                arg_uid_range,
+                                arg_selinux_apifs_context,
+                                false);
+                if (r < 0)
+                        return r;
+        }
+
+        r = mount_move_root(directory);
+        if (r < 0)
+                return log_error_errno(r, "Failed to move root directory: %m");
+
+        fd = setup_notify_child();
+        if (fd < 0)
+                return fd;
+
+        pid = raw_clone(SIGCHLD|CLONE_NEWNS|
+                        arg_clone_ns_flags |
+                        (arg_userns_mode != USER_NAMESPACE_NO ? CLONE_NEWUSER : 0));
+        if (pid < 0)
+                return log_error_errno(errno, "Failed to fork inner child: %m");
+        if (pid == 0) {
+                pid_socket = safe_close(pid_socket);
+                uuid_socket = safe_close(uuid_socket);
+                notify_socket = safe_close(notify_socket);
+                uid_shift_socket = safe_close(uid_shift_socket);
+
+                /* The inner child has all namespaces that are requested, so that we all are owned by the
+                 * user if user namespaces are turned on. */
+
+                if (arg_network_namespace_path) {
+                        r = namespace_enter(-1, -1, netns_fd, -1, -1);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to join network namespace: %m");
+                }
+
+                r = inner_child(barrier, directory, secondary, kmsg_socket, rtnl_socket, master_pty_socket, fds, os_release_pairs);
+                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))
+                return log_error_errno(SYNTHETIC_ERRNO(EIO),
+                                       "Short write while sending PID.");
+
+        l = send(uuid_socket, &arg_uuid, sizeof(arg_uuid), MSG_NOSIGNAL);
+        if (l < 0)
+                return log_error_errno(errno, "Failed to send machine ID: %m");
+        if (l != sizeof(arg_uuid))
+                return log_error_errno(SYNTHETIC_ERRNO(EIO),
+                                       "Short write while sending machine ID.");
+
+        l = send_one_fd(notify_socket, fd, 0);
+        if (l < 0)
+                return log_error_errno(l, "Failed to send notify fd: %m");
+
+        pid_socket = safe_close(pid_socket);
+        uuid_socket = safe_close(uuid_socket);
+        notify_socket = safe_close(notify_socket);
+        master_pty_socket = safe_close(master_pty_socket);
+        kmsg_socket = safe_close(kmsg_socket);
+        rtnl_socket = safe_close(rtnl_socket);
+        netns_fd = safe_close(netns_fd);
+
+        return 0;
+}
+
+static int uid_shift_pick(uid_t *shift, LockFile *ret_lock_file) {
+        bool tried_hashed = false;
+        unsigned n_tries = 100;
+        uid_t candidate;
+        int r;
+
+        assert(shift);
+        assert(ret_lock_file);
+        assert(arg_userns_mode == USER_NAMESPACE_PICK);
+        assert(arg_uid_range == 0x10000U);
+
+        candidate = *shift;
+
+        (void) mkdir("/run/systemd/nspawn-uid", 0755);
+
+        for (;;) {
+                char lock_path[STRLEN("/run/systemd/nspawn-uid/") + DECIMAL_STR_MAX(uid_t) + 1];
+                _cleanup_(release_lock_file) LockFile lf = LOCK_FILE_INIT;
+
+                if (--n_tries <= 0)
+                        return -EBUSY;
+
+                if (candidate < CONTAINER_UID_BASE_MIN || candidate > CONTAINER_UID_BASE_MAX)
+                        goto next;
+                if ((candidate & UINT32_C(0xFFFF)) != 0)
+                        goto next;
+
+                xsprintf(lock_path, "/run/systemd/nspawn-uid/" UID_FMT, candidate);
+                r = make_lock_file(lock_path, LOCK_EX|LOCK_NB, &lf);
+                if (r == -EBUSY) /* Range already taken by another nspawn instance */
+                        goto next;
+                if (r < 0)
+                        return r;
+
+                /* Make some superficial checks whether the range is currently known in the user database */
+                if (getpwuid(candidate))
+                        goto next;
+                if (getpwuid(candidate + UINT32_C(0xFFFE)))
+                        goto next;
+                if (getgrgid(candidate))
+                        goto next;
+                if (getgrgid(candidate + UINT32_C(0xFFFE)))
+                        goto next;
+
+                *ret_lock_file = lf;
+                lf = (struct LockFile) LOCK_FILE_INIT;
+                *shift = candidate;
+                return 0;
+
+        next:
+                if (arg_machine && !tried_hashed) {
+                        /* Try to hash the base from the container name */
+
+                        static const uint8_t hash_key[] = {
+                                0xe1, 0x56, 0xe0, 0xf0, 0x4a, 0xf0, 0x41, 0xaf,
+                                0x96, 0x41, 0xcf, 0x41, 0x33, 0x94, 0xff, 0x72
+                        };
+
+                        candidate = (uid_t) siphash24(arg_machine, strlen(arg_machine), hash_key);
+
+                        tried_hashed = true;
+                } else
+                        random_bytes(&candidate, sizeof(candidate));
+
+                candidate = (candidate % (CONTAINER_UID_BASE_MAX - CONTAINER_UID_BASE_MIN)) + CONTAINER_UID_BASE_MIN;
+                candidate &= (uid_t) UINT32_C(0xFFFF0000);
+        }
+}
+
+static int setup_uid_map(pid_t pid) {
+        char uid_map[STRLEN("/proc//uid_map") + DECIMAL_STR_MAX(uid_t) + 1], line[DECIMAL_STR_MAX(uid_t)*3+3+1];
+        int r;
+
+        assert(pid > 1);
+
+        xsprintf(uid_map, "/proc/" PID_FMT "/uid_map", pid);
+        xsprintf(line, UID_FMT " " UID_FMT " " UID_FMT "\n", 0, arg_uid_shift, arg_uid_range);
+        r = write_string_file(uid_map, line, WRITE_STRING_FILE_DISABLE_BUFFER);
+        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, WRITE_STRING_FILE_DISABLE_BUFFER);
+        if (r < 0)
+                return log_error_errno(r, "Failed to write GID map: %m");
+
+        return 0;
+}
+
+static int nspawn_dispatch_notify_fd(sd_event_source *source, int fd, uint32_t revents, void *userdata) {
+        char buf[NOTIFY_BUFFER_MAX+1];
+        char *p = NULL;
+        struct iovec iovec = {
+                .iov_base = buf,
+                .iov_len = sizeof(buf)-1,
+        };
+        CMSG_BUFFER_TYPE(CMSG_SPACE(sizeof(struct ucred)) +
+                         CMSG_SPACE(sizeof(int) * NOTIFY_FD_MAX)) control;
+        struct msghdr msghdr = {
+                .msg_iov = &iovec,
+                .msg_iovlen = 1,
+                .msg_control = &control,
+                .msg_controllen = sizeof(control),
+        };
+        struct ucred *ucred;
+        ssize_t n;
+        pid_t inner_child_pid;
+        _cleanup_strv_free_ char **tags = NULL;
+
+        assert(userdata);
+
+        inner_child_pid = PTR_TO_PID(userdata);
+
+        if (revents != EPOLLIN) {
+                log_warning("Got unexpected poll event for notify fd.");
+                return 0;
+        }
+
+        n = recvmsg_safe(fd, &msghdr, MSG_DONTWAIT|MSG_CMSG_CLOEXEC);
+        if (IN_SET(n, -EAGAIN, -EINTR))
+                return 0;
+        if (n == -EXFULL) {
+                log_warning("Got message with truncated control data (too many fds sent?), ignoring.");
+                return 0;
+        }
+        if (n < 0)
+                return log_warning_errno(n, "Couldn't read notification socket: %m");
+
+        cmsg_close_all(&msghdr);
+
+        ucred = CMSG_FIND_DATA(&msghdr, SOL_SOCKET, SCM_CREDENTIALS, struct ucred);
+        if (!ucred || ucred->pid != inner_child_pid) {
+                log_debug("Received notify message without valid credentials. Ignoring.");
+                return 0;
+        }
+
+        if ((size_t) n >= sizeof(buf)) {
+                log_warning("Received notify message exceeded maximum size. Ignoring.");
+                return 0;
+        }
+
+        buf[n] = 0;
+        tags = strv_split(buf, "\n\r");
+        if (!tags)
+                return log_oom();
+
+        if (strv_find(tags, "READY=1"))
+                (void) sd_notifyf(false, "READY=1\n");
+
+        p = strv_find_startswith(tags, "STATUS=");
+        if (p)
+                (void) sd_notifyf(false, "STATUS=Container running: %s", p);
+
+        return 0;
+}
+
+static int setup_notify_parent(sd_event *event, int fd, pid_t *inner_child_pid, sd_event_source **notify_event_source) {
+        int r;
+
+        r = sd_event_add_io(event, notify_event_source, fd, EPOLLIN, nspawn_dispatch_notify_fd, inner_child_pid);
+        if (r < 0)
+                return log_error_errno(r, "Failed to allocate notify event source: %m");
+
+        (void) sd_event_source_set_description(*notify_event_source, "nspawn-notify");
+
+        return 0;
+}
+
+static int merge_settings(Settings *settings, const char *path) {
+        int rl;
+
+        assert(settings);
+        assert(path);
+
+        /* Copy over bits from the settings, unless they have been explicitly masked by command line switches. Note
+         * that this steals the fields of the Settings* structure, and hence modifies it. */
+
+        if ((arg_settings_mask & SETTING_START_MODE) == 0 &&
+            settings->start_mode >= 0) {
+                arg_start_mode = settings->start_mode;
+                strv_free_and_replace(arg_parameters, settings->parameters);
+        }
+
+        if ((arg_settings_mask & SETTING_EPHEMERAL) == 0)
+                arg_ephemeral = settings->ephemeral;
+
+        if ((arg_settings_mask & SETTING_DIRECTORY) == 0 &&
+            settings->root) {
+
+                if (!arg_settings_trusted)
+                        log_warning("Ignoring root directory setting, file %s is not trusted.", path);
+                else
+                        free_and_replace(arg_directory, settings->root);
+        }
+
+        if ((arg_settings_mask & SETTING_PIVOT_ROOT) == 0 &&
+            settings->pivot_root_new) {
+                free_and_replace(arg_pivot_root_new, settings->pivot_root_new);
+                free_and_replace(arg_pivot_root_old, settings->pivot_root_old);
+        }
+
+        if ((arg_settings_mask & SETTING_WORKING_DIRECTORY) == 0 &&
+            settings->working_directory)
+                free_and_replace(arg_chdir, settings->working_directory);
+
+        if ((arg_settings_mask & SETTING_ENVIRONMENT) == 0 &&
+            settings->environment)
+                strv_free_and_replace(arg_setenv, settings->environment);
+
+        if ((arg_settings_mask & SETTING_USER) == 0) {
+
+                if (settings->user)
+                        free_and_replace(arg_user, settings->user);
+
+                if (uid_is_valid(settings->uid))
+                        arg_uid = settings->uid;
+                if (gid_is_valid(settings->gid))
+                        arg_gid = settings->gid;
+                if (settings->n_supplementary_gids > 0) {
+                        free_and_replace(arg_supplementary_gids, settings->supplementary_gids);
+                        arg_n_supplementary_gids = settings->n_supplementary_gids;
+                }
+        }
+
+        if ((arg_settings_mask & SETTING_CAPABILITY) == 0) {
+                uint64_t plus, minus;
+                uint64_t network_minus = 0;
+
+                /* Note that we copy both the simple plus/minus caps here, and the full quintet from the
+                 * Settings structure */
+
+                plus = settings->capability;
+                minus = settings->drop_capability;
+
+                if ((arg_settings_mask & SETTING_NETWORK) == 0) {
+                        if (settings_private_network(settings))
+                                plus |= UINT64_C(1) << CAP_NET_ADMIN;
+                        else
+                                network_minus |= UINT64_C(1) << CAP_NET_ADMIN;
+                }
+
+                if (!arg_settings_trusted && plus != 0) {
+                        if (settings->capability != 0)
+                                log_warning("Ignoring Capability= setting, file %s is not trusted.", path);
+                } else {
+                        arg_caps_retain &= ~network_minus;
+                        arg_caps_retain |= plus;
+                }
+
+                arg_caps_retain &= ~minus;
+
+                /* Copy the full capabilities over too */
+                if (capability_quintet_is_set(&settings->full_capabilities)) {
+                        if (!arg_settings_trusted)
+                                log_warning("Ignoring capability settings, file %s is not trusted.", path);
+                        else
+                                arg_full_capabilities = settings->full_capabilities;
+                }
+        }
+
+        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.", path);
+                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.", path);
+                else {
+                        custom_mount_free_all(arg_custom_mounts, arg_n_custom_mounts);
+                        arg_custom_mounts = TAKE_PTR(settings->custom_mounts);
+                        arg_n_custom_mounts = settings->n_custom_mounts;
+                        settings->n_custom_mounts = 0;
+                }
+        }
+
+        if ((arg_settings_mask & SETTING_NETWORK) == 0 &&
+            (settings->private_network >= 0 ||
+             settings->network_veth >= 0 ||
+             settings->network_bridge ||
+             settings->network_zone ||
+             settings->network_interfaces ||
+             settings->network_macvlan ||
+             settings->network_ipvlan ||
+             settings->network_veth_extra ||
+             settings->network_namespace_path)) {
+
+                if (!arg_settings_trusted)
+                        log_warning("Ignoring network settings, file %s is not trusted.", path);
+                else {
+                        arg_network_veth = settings_network_veth(settings);
+                        arg_private_network = settings_private_network(settings);
+
+                        strv_free_and_replace(arg_network_interfaces, settings->network_interfaces);
+                        strv_free_and_replace(arg_network_macvlan, settings->network_macvlan);
+                        strv_free_and_replace(arg_network_ipvlan, settings->network_ipvlan);
+                        strv_free_and_replace(arg_network_veth_extra, settings->network_veth_extra);
+
+                        free_and_replace(arg_network_bridge, settings->network_bridge);
+                        free_and_replace(arg_network_zone, settings->network_zone);
+
+                        free_and_replace(arg_network_namespace_path, settings->network_namespace_path);
+                }
+        }
+
+        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.", path);
+                else {
+                        expose_port_free_all(arg_expose_ports);
+                        arg_expose_ports = TAKE_PTR(settings->expose_ports);
+                }
+        }
+
+        if ((arg_settings_mask & SETTING_USERNS) == 0 &&
+            settings->userns_mode != _USER_NAMESPACE_MODE_INVALID) {
+
+                if (!arg_settings_trusted)
+                        log_warning("Ignoring PrivateUsers= and PrivateUsersChown= settings, file %s is not trusted.", path);
+                else {
+                        arg_userns_mode = settings->userns_mode;
+                        arg_uid_shift = settings->uid_shift;
+                        arg_uid_range = settings->uid_range;
+                        arg_userns_chown = settings->userns_chown;
+                }
+        }
+
+        if ((arg_settings_mask & SETTING_NOTIFY_READY) == 0)
+                arg_notify_ready = settings->notify_ready;
+
+        if ((arg_settings_mask & SETTING_SYSCALL_FILTER) == 0) {
+
+                if (!arg_settings_trusted && !strv_isempty(settings->syscall_allow_list))
+                        log_warning("Ignoring SystemCallFilter= settings, file %s is not trusted.", path);
+                else {
+                        strv_free_and_replace(arg_syscall_allow_list, settings->syscall_allow_list);
+                        strv_free_and_replace(arg_syscall_deny_list, settings->syscall_deny_list);
+                }
+
+#if HAVE_SECCOMP
+                if (!arg_settings_trusted && settings->seccomp)
+                        log_warning("Ignoring SECCOMP filter, file %s is not trusted.", path);
+                else {
+                        seccomp_release(arg_seccomp);
+                        arg_seccomp = TAKE_PTR(settings->seccomp);
+                }
+#endif
+        }
+
+        for (rl = 0; rl < _RLIMIT_MAX; rl ++) {
+                if ((arg_settings_mask & (SETTING_RLIMIT_FIRST << rl)))
+                        continue;
+
+                if (!settings->rlimit[rl])
+                        continue;
+
+                if (!arg_settings_trusted) {
+                        log_warning("Ignoring Limit%s= setting, file '%s' is not trusted.", rlimit_to_string(rl), path);
+                        continue;
+                }
+
+                free_and_replace(arg_rlimit[rl], settings->rlimit[rl]);
+        }
+
+        if ((arg_settings_mask & SETTING_HOSTNAME) == 0 &&
+            settings->hostname)
+                free_and_replace(arg_hostname, settings->hostname);
+
+        if ((arg_settings_mask & SETTING_NO_NEW_PRIVILEGES) == 0 &&
+            settings->no_new_privileges >= 0)
+                arg_no_new_privileges = settings->no_new_privileges;
+
+        if ((arg_settings_mask & SETTING_OOM_SCORE_ADJUST) == 0 &&
+            settings->oom_score_adjust_set) {
+
+                if (!arg_settings_trusted)
+                        log_warning("Ignoring OOMScoreAdjust= setting, file '%s' is not trusted.", path);
+                else {
+                        arg_oom_score_adjust = settings->oom_score_adjust;
+                        arg_oom_score_adjust_set = true;
+                }
+        }
+
+        if ((arg_settings_mask & SETTING_CPU_AFFINITY) == 0 &&
+            settings->cpu_set.set) {
+
+                if (!arg_settings_trusted)
+                        log_warning("Ignoring CPUAffinity= setting, file '%s' is not trusted.", path);
+                else {
+                        cpu_set_reset(&arg_cpu_set);
+                        arg_cpu_set = settings->cpu_set;
+                        settings->cpu_set = (CPUSet) {};
+                }
+        }
+
+        if ((arg_settings_mask & SETTING_RESOLV_CONF) == 0 &&
+            settings->resolv_conf != _RESOLV_CONF_MODE_INVALID)
+                arg_resolv_conf = settings->resolv_conf;
+
+        if ((arg_settings_mask & SETTING_LINK_JOURNAL) == 0 &&
+            settings->link_journal != _LINK_JOURNAL_INVALID) {
+
+                if (!arg_settings_trusted)
+                        log_warning("Ignoring journal link setting, file '%s' is not trusted.", path);
+                else {
+                        arg_link_journal = settings->link_journal;
+                        arg_link_journal_try = settings->link_journal_try;
+                }
+        }
+
+        if ((arg_settings_mask & SETTING_TIMEZONE) == 0 &&
+            settings->timezone != _TIMEZONE_MODE_INVALID)
+                arg_timezone = settings->timezone;
+
+        if ((arg_settings_mask & SETTING_SLICE) == 0 &&
+            settings->slice) {
+
+                if (!arg_settings_trusted)
+                        log_warning("Ignoring slice setting, file '%s' is not trusted.", path);
+                else
+                        free_and_replace(arg_slice, settings->slice);
+        }
+
+        if ((arg_settings_mask & SETTING_USE_CGNS) == 0 &&
+            settings->use_cgns >= 0) {
+
+                if (!arg_settings_trusted)
+                        log_warning("Ignoring cgroup namespace setting, file '%s' is not trusted.", path);
+                else
+                        arg_use_cgns = settings->use_cgns;
+        }
+
+        if ((arg_settings_mask & SETTING_CLONE_NS_FLAGS) == 0 &&
+            settings->clone_ns_flags != (unsigned long) -1) {
+
+                if (!arg_settings_trusted)
+                        log_warning("Ignoring namespace setting, file '%s' is not trusted.", path);
+                else
+                        arg_clone_ns_flags = settings->clone_ns_flags;
+        }
+
+        if ((arg_settings_mask & SETTING_CONSOLE_MODE) == 0 &&
+            settings->console_mode >= 0) {
+
+                if (!arg_settings_trusted)
+                        log_warning("Ignoring console mode setting, file '%s' is not trusted.", path);
+                else
+                        arg_console_mode = settings->console_mode;
+        }
+
+        /* The following properties can only be set through the OCI settings logic, not from the command line, hence we
+         * don't consult arg_settings_mask for them. */
+
+        sd_bus_message_unref(arg_property_message);
+        arg_property_message = TAKE_PTR(settings->properties);
+
+        arg_console_width = settings->console_width;
+        arg_console_height = settings->console_height;
+
+        device_node_array_free(arg_extra_nodes, arg_n_extra_nodes);
+        arg_extra_nodes = TAKE_PTR(settings->extra_nodes);
+        arg_n_extra_nodes = settings->n_extra_nodes;
+
+        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 (arg_oci_bundle)
+                return 0;
+
+        /* If all settings are masked, there's no point in looking for
+         * the settings file */
+        if (FLAGS_SET(arg_settings_mask, _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 = path_join(i, fn);
+                if (!j)
+                        return log_oom();
+
+                f = fopen(j, "re");
+                if (f) {
+                        p = TAKE_PTR(j);
+
+                        /* 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 && !path_equal(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;
+
+        return merge_settings(settings, p);
+}
+
+static int load_oci_bundle(void) {
+        _cleanup_(settings_freep) Settings *settings = NULL;
+        int r;
+
+        if (!arg_oci_bundle)
+                return 0;
+
+        /* By default let's trust OCI bundles */
+        if (arg_settings_trusted < 0)
+                arg_settings_trusted = true;
+
+        r = oci_load(NULL, arg_oci_bundle, &settings);
+        if (r < 0)
+                return r;
+
+        return merge_settings(settings, arg_oci_bundle);
+}
+
+static int run_container(
+               DissectedImage *dissected_image,
+               bool secondary,
+               FDSet *fds,
+               char veth_name[IFNAMSIZ], bool *veth_created,
+               union in_addr_union *exposed,
+               int *master, pid_t *pid, int *ret) {
+
+        static const struct sigaction sa = {
+                .sa_handler = nop_signal_handler,
+                .sa_flags = SA_NOCLDSTOP|SA_RESTART,
+        };
+
+        _cleanup_(release_lock_file) LockFile uid_shift_lock = LOCK_FILE_INIT;
+        _cleanup_close_ int etc_passwd_lock = -1;
+        _cleanup_close_pair_ int
+                kmsg_socket_pair[2] = { -1, -1 },
+                rtnl_socket_pair[2] = { -1, -1 },
+                pid_socket_pair[2] = { -1, -1 },
+                uuid_socket_pair[2] = { -1, -1 },
+                notify_socket_pair[2] = { -1, -1 },
+                uid_shift_socket_pair[2] = { -1, -1 },
+                master_pty_socket_pair[2] = { -1, -1 },
+                unified_cgroup_hierarchy_socket_pair[2] = { -1, -1};
+
+        _cleanup_close_ int notify_socket = -1;
+        _cleanup_(barrier_destroy) Barrier barrier = BARRIER_NULL;
+        _cleanup_(sd_event_source_unrefp) sd_event_source *notify_event_source = NULL;
+        _cleanup_(sd_event_unrefp) sd_event *event = NULL;
+        _cleanup_(pty_forward_freep) PTYForward *forward = NULL;
+        _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL;
+        _cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL;
+        ContainerStatus container_status = 0;
+        int ifi = 0, r;
+        ssize_t l;
+        sigset_t mask_chld;
+        _cleanup_close_ int child_netns_fd = -1;
+
+        assert_se(sigemptyset(&mask_chld) == 0);
+        assert_se(sigaddset(&mask_chld, SIGCHLD) == 0);
+
+        if (arg_userns_mode == USER_NAMESPACE_PICK) {
+                /* When we shall pick the UID/GID range, let's first lock /etc/passwd, so that we can safely
+                 * check with getpwuid() if the specific user already exists. Note that /etc might be
+                 * read-only, in which case this will fail with EROFS. But that's really OK, as in that case we
+                 * can be reasonably sure that no users are going to be added. Note that getpwuid() checks are
+                 * really just an extra safety net. We kinda assume that the UID range we allocate from is
+                 * really ours. */
+
+                etc_passwd_lock = take_etc_passwd_lock(NULL);
+                if (etc_passwd_lock < 0 && etc_passwd_lock != -EROFS)
+                        return log_error_errno(etc_passwd_lock, "Failed to take /etc/passwd lock: %m");
+        }
+
+        r = barrier_create(&barrier);
+        if (r < 0)
+                return log_error_errno(r, "Cannot initialize IPC barrier: %m");
+
+        if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, kmsg_socket_pair) < 0)
+                return log_error_errno(errno, "Failed to create kmsg socket pair: %m");
+
+        if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, rtnl_socket_pair) < 0)
+                return log_error_errno(errno, "Failed to create rtnl socket pair: %m");
+
+        if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, pid_socket_pair) < 0)
+                return log_error_errno(errno, "Failed to create pid socket pair: %m");
+
+        if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, uuid_socket_pair) < 0)
+                return log_error_errno(errno, "Failed to create id socket pair: %m");
+
+        if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, notify_socket_pair) < 0)
+                return log_error_errno(errno, "Failed to create notify socket pair: %m");
+
+        if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, master_pty_socket_pair) < 0)
+                return log_error_errno(errno, "Failed to create console socket pair: %m");
+
+        if (arg_userns_mode != USER_NAMESPACE_NO)
+                if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, uid_shift_socket_pair) < 0)
+                        return log_error_errno(errno, "Failed to create uid shift socket pair: %m");
+
+        if (arg_unified_cgroup_hierarchy == CGROUP_UNIFIED_UNKNOWN)
+                if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, unified_cgroup_hierarchy_socket_pair) < 0)
+                        return log_error_errno(errno, "Failed to create unified cgroup socket pair: %m");
+
+        /* Child can be killed before execv(), so handle SIGCHLD in order to interrupt
+         * parent's blocking calls and give it a chance to call wait() and terminate. */
+        r = sigprocmask(SIG_UNBLOCK, &mask_chld, NULL);
+        if (r < 0)
+                return log_error_errno(errno, "Failed to change the signal mask: %m");
+
+        r = sigaction(SIGCHLD, &sa, NULL);
+        if (r < 0)
+                return log_error_errno(errno, "Failed to install SIGCHLD handler: %m");
+
+        if (arg_network_namespace_path) {
+                child_netns_fd = open(arg_network_namespace_path, O_RDONLY|O_NOCTTY|O_CLOEXEC);
+                if (child_netns_fd < 0)
+                        return log_error_errno(errno, "Cannot open file %s: %m", arg_network_namespace_path);
+
+                r = fd_is_network_ns(child_netns_fd);
+                if (r == -EUCLEAN)
+                        log_debug_errno(r, "Cannot determine if passed network namespace path '%s' really refers to a network namespace, assuming it does.", arg_network_namespace_path);
+                else if (r < 0)
+                        return log_error_errno(r, "Failed to check %s fs type: %m", arg_network_namespace_path);
+                else if (r == 0)
+                        return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                               "Path %s doesn't refer to a network namespace, refusing.", arg_network_namespace_path);
+        }
+
+        *pid = raw_clone(SIGCHLD|CLONE_NEWNS);
+        if (*pid < 0)
+                return log_error_errno(errno, "clone() failed%s: %m",
+                                       errno == EINVAL ?
+                                       ", do you have namespace support enabled in your kernel? (You need UTS, IPC, PID and NET namespacing built in)" : "");
+
+        if (*pid == 0) {
+                /* The outer child only has a file system namespace. */
+                barrier_set_role(&barrier, BARRIER_CHILD);
+
+                kmsg_socket_pair[0] = safe_close(kmsg_socket_pair[0]);
+                rtnl_socket_pair[0] = safe_close(rtnl_socket_pair[0]);
+                pid_socket_pair[0] = safe_close(pid_socket_pair[0]);
+                uuid_socket_pair[0] = safe_close(uuid_socket_pair[0]);
+                notify_socket_pair[0] = safe_close(notify_socket_pair[0]);
+                master_pty_socket_pair[0] = safe_close(master_pty_socket_pair[0]);
+                uid_shift_socket_pair[0] = safe_close(uid_shift_socket_pair[0]);
+                unified_cgroup_hierarchy_socket_pair[0] = safe_close(unified_cgroup_hierarchy_socket_pair[0]);
+
+                (void) reset_all_signal_handlers();
+                (void) reset_signal_mask();
+
+                r = outer_child(&barrier,
+                                arg_directory,
+                                dissected_image,
+                                secondary,
+                                pid_socket_pair[1],
+                                uuid_socket_pair[1],
+                                notify_socket_pair[1],
+                                kmsg_socket_pair[1],
+                                rtnl_socket_pair[1],
+                                uid_shift_socket_pair[1],
+                                master_pty_socket_pair[1],
+                                unified_cgroup_hierarchy_socket_pair[1],
+                                fds,
+                                child_netns_fd);
+                if (r < 0)
+                        _exit(EXIT_FAILURE);
+
+                _exit(EXIT_SUCCESS);
+        }
+
+        barrier_set_role(&barrier, BARRIER_PARENT);
+
+        fdset_close(fds);
+
+        kmsg_socket_pair[1] = safe_close(kmsg_socket_pair[1]);
+        rtnl_socket_pair[1] = safe_close(rtnl_socket_pair[1]);
+        pid_socket_pair[1] = safe_close(pid_socket_pair[1]);
+        uuid_socket_pair[1] = safe_close(uuid_socket_pair[1]);
+        notify_socket_pair[1] = safe_close(notify_socket_pair[1]);
+        master_pty_socket_pair[1] = safe_close(master_pty_socket_pair[1]);
+        uid_shift_socket_pair[1] = safe_close(uid_shift_socket_pair[1]);
+        unified_cgroup_hierarchy_socket_pair[1] = safe_close(unified_cgroup_hierarchy_socket_pair[1]);
+
+        if (arg_userns_mode != USER_NAMESPACE_NO) {
+                /* The child just let us know the UID shift it might have read from the image. */
+                l = recv(uid_shift_socket_pair[0], &arg_uid_shift, sizeof arg_uid_shift, 0);
+                if (l < 0)
+                        return log_error_errno(errno, "Failed to read UID shift: %m");
+                if (l != sizeof arg_uid_shift)
+                        return log_error_errno(SYNTHETIC_ERRNO(EIO), "Short read while reading UID shift.");
+
+                if (arg_userns_mode == USER_NAMESPACE_PICK) {
+                        /* If we are supposed to pick the UID shift, let's try to use the shift read from the
+                         * image, but if that's already in use, pick a new one, and report back to the child,
+                         * which one we now picked. */
+
+                        r = uid_shift_pick(&arg_uid_shift, &uid_shift_lock);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to pick suitable UID/GID range: %m");
+
+                        l = send(uid_shift_socket_pair[0], &arg_uid_shift, sizeof arg_uid_shift, MSG_NOSIGNAL);
+                        if (l < 0)
+                                return log_error_errno(errno, "Failed to send UID shift: %m");
+                        if (l != sizeof arg_uid_shift)
+                                return log_error_errno(SYNTHETIC_ERRNO(EIO), "Short write while writing UID shift.");
+                }
+        }
+
+        if (arg_unified_cgroup_hierarchy == CGROUP_UNIFIED_UNKNOWN) {
+                /* The child let us know the support cgroup mode it might have read from the image. */
+                l = recv(unified_cgroup_hierarchy_socket_pair[0], &arg_unified_cgroup_hierarchy, sizeof(arg_unified_cgroup_hierarchy), 0);
+                if (l < 0)
+                        return log_error_errno(errno, "Failed to read cgroup mode: %m");
+                if (l != sizeof(arg_unified_cgroup_hierarchy))
+                        return log_error_errno(SYNTHETIC_ERRNO(EIO), "Short read while reading cgroup mode (%zu bytes).%s",
+                                               l, l == 0 ? " The child is most likely dead." : "");
+        }
+
+        /* Wait for the outer child. */
+        r = wait_for_terminate_and_check("(sd-namespace)", *pid, WAIT_LOG_ABNORMAL);
+        if (r < 0)
+                return r;
+        if (r != EXIT_SUCCESS)
+                return -EIO;
+
+        /* And now retrieve the PID of the inner child. */
+        l = recv(pid_socket_pair[0], pid, sizeof *pid, 0);
+        if (l < 0)
+                return log_error_errno(errno, "Failed to read inner child PID: %m");
+        if (l != sizeof *pid)
+                return log_error_errno(SYNTHETIC_ERRNO(EIO), "Short read while reading inner child PID.");
+
+        /* We also retrieve container UUID in case it was generated by outer child */
+        l = recv(uuid_socket_pair[0], &arg_uuid, sizeof arg_uuid, 0);
+        if (l < 0)
+                return log_error_errno(errno, "Failed to read container machine ID: %m");
+        if (l != sizeof(arg_uuid))
+                return log_error_errno(SYNTHETIC_ERRNO(EIO), "Short read while reading container machined ID.");
+
+        /* We also retrieve the socket used for notifications generated by outer child */
+        notify_socket = receive_one_fd(notify_socket_pair[0], 0);
+        if (notify_socket < 0)
+                return log_error_errno(notify_socket,
+                                       "Failed to receive notification socket from the outer child: %m");
+
+        log_debug("Init process invoked as PID "PID_FMT, *pid);
+
+        if (arg_userns_mode != USER_NAMESPACE_NO) {
+                if (!barrier_place_and_sync(&barrier)) /* #1 */
+                        return log_error_errno(SYNTHETIC_ERRNO(ESRCH), "Child died too early.");
+
+                r = setup_uid_map(*pid);
+                if (r < 0)
+                        return r;
+
+                (void) barrier_place(&barrier); /* #2 */
+        }
+
+        if (arg_private_network) {
+                if (!arg_network_namespace_path) {
+                        /* Wait until the child has unshared its network namespace. */
+                        if (!barrier_place_and_sync(&barrier)) /* #3 */
+                                return log_error_errno(SYNTHETIC_ERRNO(ESRCH), "Child died too early");
+                }
+
+                if (child_netns_fd < 0) {
+                        /* Make sure we have an open file descriptor to the child's network
+                         * namespace so it stays alive even if the child exits. */
+                        r = namespace_open(*pid, NULL, NULL, &child_netns_fd, NULL, NULL);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to open child network namespace: %m");
+                }
+
+                r = move_network_interfaces(child_netns_fd, arg_network_interfaces);
+                if (r < 0)
+                        return r;
+
+                if (arg_network_veth) {
+                        r = setup_veth(arg_machine, *pid, veth_name,
+                                       arg_network_bridge || arg_network_zone);
+                        if (r < 0)
+                                return r;
+                        else if (r > 0)
+                                ifi = r;
+
+                        if (arg_network_bridge) {
+                                /* Add the interface to a bridge */
+                                r = setup_bridge(veth_name, arg_network_bridge, false);
+                                if (r < 0)
+                                        return r;
+                                if (r > 0)
+                                        ifi = r;
+                        } else if (arg_network_zone) {
+                                /* Add the interface to a bridge, possibly creating it */
+                                r = setup_bridge(veth_name, arg_network_zone, true);
+                                if (r < 0)
+                                        return r;
+                                if (r > 0)
+                                        ifi = r;
+                        }
+                }
+
+                r = setup_veth_extra(arg_machine, *pid, arg_network_veth_extra);
+                if (r < 0)
+                        return r;
+
+                /* We created the primary and extra veth links now; let's remember this, so that we know to
+                   remove them later on. Note that we don't bother with removing veth links that were created
+                   here when their setup failed half-way, because in that case the kernel should be able to
+                   remove them on its own, since they cannot be referenced by anything yet. */
+                *veth_created = true;
+
+                r = setup_macvlan(arg_machine, *pid, arg_network_macvlan);
+                if (r < 0)
+                        return r;
+
+                r = setup_ipvlan(arg_machine, *pid, arg_network_ipvlan);
+                if (r < 0)
+                        return r;
+        }
+
+        if (arg_register || !arg_keep_unit) {
+                r = sd_bus_default_system(&bus);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to open system bus: %m");
+
+                r = sd_bus_set_close_on_exit(bus, false);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to disable close-on-exit behaviour: %m");
+        }
+
+        if (!arg_keep_unit) {
+                /* When a new scope is created for this container, then we'll be registered as its controller, in which
+                 * case PID 1 will send us a friendly RequestStop signal, when it is asked to terminate the
+                 * scope. Let's hook into that, and cleanly shut down the container, and print a friendly message. */
+
+                r = sd_bus_match_signal_async(
+                                bus,
+                                NULL,
+                                "org.freedesktop.systemd1",
+                                NULL,
+                                "org.freedesktop.systemd1.Scope",
+                                "RequestStop",
+                                on_request_stop, NULL, PID_TO_PTR(*pid));
+                if (r < 0)
+                        return log_error_errno(r, "Failed to request RequestStop match: %m");
+        }
+
+        if (arg_register) {
+                r = register_machine(
+                                bus,
+                                arg_machine,
+                                *pid,
+                                arg_directory,
+                                arg_uuid,
+                                ifi,
+                                arg_slice,
+                                arg_custom_mounts, arg_n_custom_mounts,
+                                arg_kill_signal,
+                                arg_property,
+                                arg_property_message,
+                                arg_keep_unit,
+                                arg_container_service_name);
+                if (r < 0)
+                        return r;
+
+        } else if (!arg_keep_unit) {
+                r = allocate_scope(
+                                bus,
+                                arg_machine,
+                                *pid,
+                                arg_slice,
+                                arg_custom_mounts, arg_n_custom_mounts,
+                                arg_kill_signal,
+                                arg_property,
+                                arg_property_message);
+                if (r < 0)
+                        return r;
+
+        } else if (arg_slice || arg_property)
+                log_notice("Machine and scope registration turned off, --slice= and --property= settings will have no effect.");
+
+        r = create_subcgroup(*pid, arg_keep_unit, arg_unified_cgroup_hierarchy);
+        if (r < 0)
+                return r;
+
+        r = sync_cgroup(*pid, arg_unified_cgroup_hierarchy, arg_uid_shift);
+        if (r < 0)
+                return r;
+
+        r = chown_cgroup(*pid, arg_unified_cgroup_hierarchy, arg_uid_shift);
+        if (r < 0)
+                return r;
+
+        /* Notify the child that the parent is ready with all
+         * its setup (including cgroup-ification), and that
+         * the child can now hand over control to the code to
+         * run inside the container. */
+        (void) barrier_place(&barrier); /* #4 */
+
+        /* Block SIGCHLD here, before notifying child.
+         * process_pty() will handle it with the other signals. */
+        assert_se(sigprocmask(SIG_BLOCK, &mask_chld, NULL) >= 0);
+
+        /* Reset signal to default */
+        r = default_signals(SIGCHLD, -1);
+        if (r < 0)
+                return log_error_errno(r, "Failed to reset SIGCHLD: %m");
+
+        r = sd_event_new(&event);
+        if (r < 0)
+                return log_error_errno(r, "Failed to get default event source: %m");
+
+        (void) sd_event_set_watchdog(event, true);
+
+        if (bus) {
+                r = sd_bus_attach_event(bus, event, 0);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to attach bus to event loop: %m");
+        }
+
+        r = setup_notify_parent(event, notify_socket, PID_TO_PTR(*pid), &notify_event_source);
+        if (r < 0)
+                return r;
+
+        /* Let the child know that we are ready and wait that the child is completely ready now. */
+        if (!barrier_place_and_sync(&barrier)) /* #5 */
+                return log_error_errno(SYNTHETIC_ERRNO(ESRCH), "Child died too early.");
+
+        /* At this point we have made use of the UID we picked, and thus nss-systemd/systemd-machined.service
+         * will make them appear in getpwuid(), thus we can release the /etc/passwd lock. */
+        etc_passwd_lock = safe_close(etc_passwd_lock);
+
+        (void) sd_notifyf(false,
+                          "STATUS=Container running.\n"
+                          "X_NSPAWN_LEADER_PID=" PID_FMT, *pid);
+        if (!arg_notify_ready)
+                (void) sd_notify(false, "READY=1\n");
+
+        if (arg_kill_signal > 0) {
+                /* Try to kill the init system on SIGINT or SIGTERM */
+                (void) sd_event_add_signal(event, NULL, SIGINT, on_orderly_shutdown, PID_TO_PTR(*pid));
+                (void) sd_event_add_signal(event, NULL, SIGTERM, on_orderly_shutdown, PID_TO_PTR(*pid));
+        } else {
+                /* Immediately exit */
+                (void) sd_event_add_signal(event, NULL, SIGINT, NULL, NULL);
+                (void) sd_event_add_signal(event, NULL, SIGTERM, NULL, NULL);
+        }
+
+        /* Exit when the child exits */
+        (void) sd_event_add_signal(event, NULL, SIGCHLD, on_sigchld, PID_TO_PTR(*pid));
+
+        if (arg_expose_ports) {
+                r = expose_port_watch_rtnl(event, rtnl_socket_pair[0], on_address_change, exposed, &rtnl);
+                if (r < 0)
+                        return r;
+
+                (void) expose_port_execute(rtnl, arg_expose_ports, exposed);
+        }
+
+        rtnl_socket_pair[0] = safe_close(rtnl_socket_pair[0]);
+
+        if (arg_console_mode != CONSOLE_PIPE) {
+                _cleanup_close_ int fd = -1;
+                PTYForwardFlags flags = 0;
+
+                /* Retrieve the master pty allocated by inner child */
+                fd = receive_one_fd(master_pty_socket_pair[0], 0);
+                if (fd < 0)
+                        return log_error_errno(fd, "Failed to receive master pty from the inner child: %m");
+
+                switch (arg_console_mode) {
+
+                case CONSOLE_READ_ONLY:
+                        flags |= PTY_FORWARD_READ_ONLY;
+
+                        _fallthrough_;
+
+                case CONSOLE_INTERACTIVE:
+                        flags |= PTY_FORWARD_IGNORE_VHANGUP;
+
+                        r = pty_forward_new(event, fd, flags, &forward);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to create PTY forwarder: %m");
+
+                        if (arg_console_width != (unsigned) -1 || arg_console_height != (unsigned) -1)
+                                (void) pty_forward_set_width_height(forward,
+                                                                    arg_console_width,
+                                                                    arg_console_height);
+                        break;
+
+                default:
+                        assert(arg_console_mode == CONSOLE_PASSIVE);
+                }
+
+                *master = TAKE_FD(fd);
+        }
+
+        r = sd_event_loop(event);
+        if (r < 0)
+                return log_error_errno(r, "Failed to run event loop: %m");
+
+        if (forward) {
+                char last_char = 0;
+
+                (void) 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 && bus)
+                terminate_scope(bus, arg_machine);
+
+        /* Normally redundant, but better safe than sorry */
+        (void) kill(*pid, SIGKILL);
+
+        if (arg_private_network) {
+                /* Move network interfaces back to the parent network namespace. We use `safe_fork`
+                 * to avoid having to move the parent to the child network namespace. */
+                r = safe_fork(NULL, FORK_RESET_SIGNALS|FORK_DEATHSIG|FORK_WAIT|FORK_LOG, NULL);
+                if (r < 0)
+                        return r;
+
+                if (r == 0) {
+                        _cleanup_close_ int parent_netns_fd = -1;
+
+                        r = namespace_open(getpid(), NULL, NULL, &parent_netns_fd, NULL, NULL);
+                        if (r < 0) {
+                                log_error_errno(r, "Failed to open parent network namespace: %m");
+                                _exit(EXIT_FAILURE);
+                        }
+
+                        r = namespace_enter(-1, -1, child_netns_fd, -1, -1);
+                        if (r < 0) {
+                                log_error_errno(r, "Failed to enter child network namespace: %m");
+                                _exit(EXIT_FAILURE);
+                        }
+
+                        r = move_network_interfaces(parent_netns_fd, arg_network_interfaces);
+                        if (r < 0)
+                                log_error_errno(r, "Failed to move network interfaces back to parent network namespace: %m");
+
+                        _exit(r < 0 ? EXIT_FAILURE : EXIT_SUCCESS);
+                }
+        }
+
+        r = wait_for_container(*pid, &container_status);
+        *pid = 0;
+
+        /* Tell machined that we are gone. */
+        if (bus)
+                (void) unregister_machine(bus, arg_machine);
+
+        if (r < 0)
+                /* We failed to wait for the container, or the container exited abnormally. */
+                return r;
+        if (r > 0 || container_status == CONTAINER_TERMINATED) {
+                /* r > 0 → The container exited with a non-zero status.
+                 *         As a special case, we need to replace 133 with a different value,
+                 *         because 133 is special-cased in the service file to reboot the container.
+                 * otherwise → The container exited with zero status and a reboot was not requested.
+                 */
+                if (r == EXIT_FORCE_RESTART)
+                        r = EXIT_FAILURE; /* replace 133 with the general failure code */
+                *ret = r;
+                return 0; /* finito */
+        }
+
+        /* CONTAINER_REBOOTED, loop again */
+
+        if (arg_keep_unit) {
+                /* Special handling if we are running as a service: instead of simply
+                 * restarting the machine we want to restart the entire service, so let's
+                 * inform systemd about this with the special exit code 133. The service
+                 * file uses RestartForceExitStatus=133 so that this results in a full
+                 * nspawn restart. This is necessary since we might have cgroup parameters
+                 * set we want to have flushed out. */
+                *ret = EXIT_FORCE_RESTART;
+                return 0; /* finito */
+        }
+
+        expose_port_flush(arg_expose_ports, exposed);
+
+        (void) remove_veth_links(veth_name, arg_network_veth_extra);
+        *veth_created = false;
+        return 1; /* loop again */
+}
+
+static int initialize_rlimits(void) {
+        /* The default resource limits the kernel passes to PID 1, as per kernel 4.16. Let's pass our container payload
+         * the same values as the kernel originally passed to PID 1, in order to minimize differences between host and
+         * container execution environments. */
+
+        static const struct rlimit kernel_defaults[_RLIMIT_MAX] = {
+                [RLIMIT_AS]       = { RLIM_INFINITY, RLIM_INFINITY },
+                [RLIMIT_CORE]     = { 0,             RLIM_INFINITY },
+                [RLIMIT_CPU]      = { RLIM_INFINITY, RLIM_INFINITY },
+                [RLIMIT_DATA]     = { RLIM_INFINITY, RLIM_INFINITY },
+                [RLIMIT_FSIZE]    = { RLIM_INFINITY, RLIM_INFINITY },
+                [RLIMIT_LOCKS]    = { RLIM_INFINITY, RLIM_INFINITY },
+                [RLIMIT_MEMLOCK]  = { 65536,         65536         },
+                [RLIMIT_MSGQUEUE] = { 819200,        819200        },
+                [RLIMIT_NICE]     = { 0,             0             },
+                [RLIMIT_NOFILE]   = { 1024,          4096          },
+                [RLIMIT_RSS]      = { RLIM_INFINITY, RLIM_INFINITY },
+                [RLIMIT_RTPRIO]   = { 0,             0             },
+                [RLIMIT_RTTIME]   = { RLIM_INFINITY, RLIM_INFINITY },
+                [RLIMIT_STACK]    = { 8388608,       RLIM_INFINITY },
+
+                /* The kernel scales the default for RLIMIT_NPROC and RLIMIT_SIGPENDING based on the system's amount of
+                 * RAM. To provide best compatibility we'll read these limits off PID 1 instead of hardcoding them
+                 * here. This is safe as we know that PID 1 doesn't change these two limits and thus the original
+                 * kernel's initialization should still be valid during runtime — at least if PID 1 is systemd. Note
+                 * that PID 1 changes a number of other resource limits during early initialization which is why we
+                 * don't read the other limits from PID 1 but prefer the static table above. */
+        };
+
+        int rl;
+
+        for (rl = 0; rl < _RLIMIT_MAX; rl++) {
+                /* Let's only fill in what the user hasn't explicitly configured anyway */
+                if ((arg_settings_mask & (SETTING_RLIMIT_FIRST << rl)) == 0) {
+                        const struct rlimit *v;
+                        struct rlimit buffer;
+
+                        if (IN_SET(rl, RLIMIT_NPROC, RLIMIT_SIGPENDING)) {
+                                /* For these two let's read the limits off PID 1. See above for an explanation. */
+
+                                if (prlimit(1, rl, NULL, &buffer) < 0)
+                                        return log_error_errno(errno, "Failed to read resource limit RLIMIT_%s of PID 1: %m", rlimit_to_string(rl));
+
+                                v = &buffer;
+                        } else
+                                v = kernel_defaults + rl;
+
+                        arg_rlimit[rl] = newdup(struct rlimit, v, 1);
+                        if (!arg_rlimit[rl])
+                                return log_oom();
+                }
+
+                if (DEBUG_LOGGING) {
+                        _cleanup_free_ char *k = NULL;
+
+                        (void) rlimit_format(arg_rlimit[rl], &k);
+                        log_debug("Setting RLIMIT_%s to %s.", rlimit_to_string(rl), k);
+                }
+        }
+
+        return 0;
+}
+
+static int cant_be_in_netns(void) {
+        union sockaddr_union sa = {
+                .un = {
+                        .sun_family = AF_UNIX,
+                        .sun_path = "/run/udev/control",
+                },
+        };
+        char udev_path[STRLEN("/proc//ns/net") + DECIMAL_STR_MAX(pid_t)];
+        _cleanup_free_ char *udev_ns = NULL, *our_ns = NULL;
+        _cleanup_close_ int fd = -1;
+        struct ucred ucred;
+        int r;
+
+        /* Check if we are in the same netns as udev. If we aren't, then device monitoring (and thus waiting
+         * for loopback block devices) won't work, and we will hang. Detect this case and exit early with a
+         * nice message. */
+
+        if (!arg_image) /* only matters if --image= us used, i.e. we actually need to use loopback devices */
+                return 0;
+
+        fd = socket(AF_UNIX, SOCK_SEQPACKET|SOCK_NONBLOCK|SOCK_CLOEXEC, 0);
+        if (fd < 0)
+                return log_error_errno(errno, "Failed to allocate udev control socket: %m");
+
+        if (connect(fd, &sa.un, SOCKADDR_UN_LEN(sa.un)) < 0) {
+
+                if (errno == ENOENT || ERRNO_IS_DISCONNECT(errno))
+                        return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP),
+                                               "Sorry, but --image= requires access to the host's /run/ hierarchy, since we need access to udev.");
+
+                return log_error_errno(errno, "Failed to connect socket to udev control socket: %m");
+        }
+
+        r = getpeercred(fd, &ucred);
+        if (r < 0)
+                return log_error_errno(r, "Failed to determine peer of udev control socket: %m");
+
+        xsprintf(udev_path, "/proc/" PID_FMT "/ns/net", ucred.pid);
+        r = readlink_malloc(udev_path, &udev_ns);
+        if (r < 0)
+                return log_error_errno(r, "Failed to read network namespace of udev: %m");
+
+        r = readlink_malloc("/proc/self/ns/net", &our_ns);
+        if (r < 0)
+                return log_error_errno(r, "Failed to read our own network namespace: %m");
+
+        if (!streq(our_ns, udev_ns))
+                return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP),
+                                       "Sorry, but --image= is only supported in the main network namespace, since we need access to udev/AF_NETLINK.");
+        return 0;
+}
+
+static int run(int argc, char *argv[]) {
+        bool secondary = false, remove_directory = false, remove_image = false,
+                veth_created = false, remove_tmprootdir = false;
+        _cleanup_close_ int master = -1;
+        _cleanup_fdset_free_ FDSet *fds = NULL;
+        int r, n_fd_passed, ret = EXIT_SUCCESS;
+        char veth_name[IFNAMSIZ] = "";
+        union in_addr_union exposed = {};
+        _cleanup_(release_lock_file) LockFile tree_global_lock = LOCK_FILE_INIT, tree_local_lock = LOCK_FILE_INIT;
+        char tmprootdir[] = "/tmp/nspawn-root-XXXXXX";
+        _cleanup_(loop_device_unrefp) LoopDevice *loop = NULL;
+        _cleanup_(decrypted_image_unrefp) DecryptedImage *decrypted_image = NULL;
+        _cleanup_(dissected_image_unrefp) DissectedImage *dissected_image = NULL;
+        pid_t pid = 0;
+
+        log_parse_environment();
+        log_open();
+
+        r = parse_argv(argc, argv);
+        if (r <= 0)
+                goto finish;
+
+        if (geteuid() != 0) {
+                r = log_warning_errno(SYNTHETIC_ERRNO(EPERM),
+                                      argc >= 2 ? "Need to be root." :
+                                      "Need to be root (and some arguments are usually required).\nHint: try --help");
+                goto finish;
+        }
+
+        r = cant_be_in_netns();
+        if (r < 0)
+                goto finish;
+
+        r = initialize_rlimits();
+        if (r < 0)
+                goto finish;
+
+        r = load_oci_bundle();
+        if (r < 0)
+                goto finish;
+
+        r = determine_names();
+        if (r < 0)
+                goto finish;
+
+        r = load_settings();
+        if (r < 0)
+                goto finish;
+
+        r = cg_unified();
+        if (r < 0) {
+                log_error_errno(r, "Failed to determine whether the unified cgroups hierarchy is used: %m");
+                goto finish;
+        }
+
+        r = verify_arguments();
+        if (r < 0)
+                goto finish;
+
+        /* Reapply environment settings. */
+        (void) detect_unified_cgroup_hierarchy_from_environment();
+
+        /* Ignore SIGPIPE here, because we use splice() on the ptyfwd stuff and that will generate SIGPIPE if
+         * the result is closed. Note that the container payload child will reset signal mask+handler anyway,
+         * so just turning this off here means we only turn it off in nspawn itself, not any children. */
+        (void) ignore_signals(SIGPIPE, -1);
+
+        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;
+                }
+        }
+
+        /* The "default" umask. This is appropriate for most file and directory
+        * operations performed by nspawn, and is the umask that will be used for
+        * the child. Functions like copy_devnodes() change the umask temporarily. */
+        umask(0022);
+
+        if (arg_directory) {
+                assert(!arg_image);
+
+                /* Safety precaution: let's not allow running images from the live host OS image, as long as
+                 * /var from the host will propagate into container dynamically (because bad things happen if
+                 * two systems write to the same /var). Let's allow it for the special cases where /var is
+                 * either copied (i.e. --ephemeral) or replaced (i.e. --volatile=yes|state). */
+                if (path_equal(arg_directory, "/") && !(arg_ephemeral || IN_SET(arg_volatile_mode, VOLATILE_YES, VOLATILE_STATE))) {
+                        log_error("Spawning container on root directory is not supported. Consider using --ephemeral, --volatile=yes or --volatile=state.");
+                        r = -EINVAL;
+                        goto finish;
+                }
+
+                if (arg_ephemeral) {
+                        _cleanup_free_ char *np = NULL;
+
+                        r = chase_symlinks_and_update(&arg_directory, 0);
+                        if (r < 0)
+                                goto finish;
+
+                        /* 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, NULL, 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 directory snapshot: %m");
+                                goto finish;
+                        }
+
+                        /* We take an exclusive lock on this image, since it's our private, ephemeral copy
+                         * only owned by us and no one else. */
+                        r = image_path_lock(np, 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;
+                        }
+
+                        {
+                                BLOCK_SIGNALS(SIGINT);
+                                r = btrfs_subvol_snapshot(arg_directory, np,
+                                                          (arg_read_only ? BTRFS_SNAPSHOT_READ_ONLY : 0) |
+                                                          BTRFS_SNAPSHOT_FALLBACK_COPY |
+                                                          BTRFS_SNAPSHOT_FALLBACK_DIRECTORY |
+                                                          BTRFS_SNAPSHOT_RECURSIVE |
+                                                          BTRFS_SNAPSHOT_QUOTA |
+                                                          BTRFS_SNAPSHOT_SIGINT);
+                        }
+                        if (r == -EINTR) {
+                                log_error_errno(r, "Interrupted while copying file system tree to %s, removed again.", np);
+                                goto finish;
+                        }
+                        if (r < 0) {
+                                log_error_errno(r, "Failed to create snapshot %s from %s: %m", np, arg_directory);
+                                goto finish;
+                        }
+
+                        free_and_replace(arg_directory, np);
+                        remove_directory = true;
+                } else {
+                        r = chase_symlinks_and_update(&arg_directory, arg_template ? CHASE_NONEXISTENT : 0);
+                        if (r < 0)
+                                goto finish;
+
+                        r = image_path_lock(arg_directory, (arg_read_only ? LOCK_SH : LOCK_EX) | LOCK_NB, &tree_global_lock, &tree_local_lock);
+                        if (r == -EBUSY) {
+                                log_error_errno(r, "Directory tree %s is currently busy.", arg_directory);
+                                goto finish;
+                        }
+                        if (r < 0) {
+                                log_error_errno(r, "Failed to lock %s: %m", arg_directory);
+                                goto finish;
+                        }
+
+                        if (arg_template) {
+                                r = chase_symlinks_and_update(&arg_template, 0);
+                                if (r < 0)
+                                        goto finish;
+
+                                {
+                                        BLOCK_SIGNALS(SIGINT);
+                                        r = btrfs_subvol_snapshot(arg_template, arg_directory,
+                                                                  (arg_read_only ? BTRFS_SNAPSHOT_READ_ONLY : 0) |
+                                                                  BTRFS_SNAPSHOT_FALLBACK_COPY |
+                                                                  BTRFS_SNAPSHOT_FALLBACK_DIRECTORY |
+                                                                  BTRFS_SNAPSHOT_FALLBACK_IMMUTABLE |
+                                                                  BTRFS_SNAPSHOT_RECURSIVE |
+                                                                  BTRFS_SNAPSHOT_QUOTA |
+                                                                  BTRFS_SNAPSHOT_SIGINT);
+                                }
+                                if (r == -EEXIST)
+                                        log_full(arg_quiet ? LOG_DEBUG : LOG_INFO,
+                                                 "Directory %s already exists, not populating from template %s.", arg_directory, arg_template);
+                                else if (r == -EINTR) {
+                                        log_error_errno(r, "Interrupted while copying file system tree to %s, removed again.", arg_directory);
+                                        goto finish;
+                                } else if (r < 0) {
+                                        log_error_errno(r, "Couldn't create snapshot %s from %s: %m", arg_directory, arg_template);
+                                        goto finish;
+                                } else
+                                        log_full(arg_quiet ? LOG_DEBUG : LOG_INFO,
+                                                 "Populated %s from template %s.", arg_directory, arg_template);
+                        }
+                }
+
+                if (arg_start_mode == START_BOOT) {
+                        const char *p;
+
+                        if (arg_pivot_root_new)
+                                p = prefix_roota(arg_directory, arg_pivot_root_new);
+                        else
+                                p = arg_directory;
+
+                        if (path_is_os_tree(p) <= 0) {
+                                log_error("Directory %s doesn't look like an OS root directory (os-release file is missing). Refusing.", p);
+                                r = -EINVAL;
+                                goto finish;
+                        }
+                } else {
+                        const char *p, *q;
+
+                        if (arg_pivot_root_new)
+                                p = prefix_roota(arg_directory, arg_pivot_root_new);
+                        else
+                                p = arg_directory;
+
+                        q = strjoina(p, "/usr/");
+
+                        if (laccess(q, F_OK) < 0) {
+                                log_error("Directory %s doesn't look like it has an OS tree. Refusing.", p);
+                                r = -EINVAL;
+                                goto finish;
+                        }
+                }
+
+        } else {
+                DissectImageFlags dissect_image_flags = DISSECT_IMAGE_REQUIRE_ROOT | DISSECT_IMAGE_RELAX_VAR_CHECK;
+                assert(arg_image);
+                assert(!arg_template);
+
+                r = chase_symlinks_and_update(&arg_image, 0);
+                if (r < 0)
+                        goto finish;
+
+                if (arg_ephemeral)  {
+                        _cleanup_free_ char *np = NULL;
+
+                        r = tempfn_random(arg_image, "machine.", &np);
+                        if (r < 0) {
+                                log_error_errno(r, "Failed to generate name for image snapshot: %m");
+                                goto finish;
+                        }
+
+                        /* Always take an exclusive lock on our own ephemeral copy. */
+                        r = image_path_lock(np, LOCK_EX|LOCK_NB, &tree_global_lock, &tree_local_lock);
+                        if (r < 0) {
+                                r = log_error_errno(r, "Failed to create image lock: %m");
+                                goto finish;
+                        }
+
+                        {
+                                BLOCK_SIGNALS(SIGINT);
+                                r = copy_file(arg_image, np, O_EXCL, arg_read_only ? 0400 : 0600, FS_NOCOW_FL, FS_NOCOW_FL, COPY_REFLINK|COPY_CRTIME|COPY_SIGINT);
+                        }
+                        if (r == -EINTR) {
+                                log_error_errno(r, "Interrupted while copying image file to %s, removed again.", np);
+                                goto finish;
+                        }
+                        if (r < 0) {
+                                r = log_error_errno(r, "Failed to copy image file: %m");
+                                goto finish;
+                        }
+
+                        free_and_replace(arg_image, np);
+                        remove_image = true;
+                } else {
+                        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;
+                        }
+
+                        r = verity_settings_load(
+                                        &arg_verity_settings,
+                                        arg_image, NULL, NULL);
+                        if (r < 0) {
+                                log_error_errno(r, "Failed to read verity artefacts for %s: %m", arg_image);
+                                goto finish;
+                        }
+
+                        if (arg_verity_settings.data_path)
+                                dissect_image_flags |= DISSECT_IMAGE_NO_PARTITION_TABLE;
+                }
+
+                if (!mkdtemp(tmprootdir)) {
+                        r = log_error_errno(errno, "Failed to create temporary directory: %m");
+                        goto finish;
+                }
+
+                remove_tmprootdir = true;
+
+                arg_directory = strdup(tmprootdir);
+                if (!arg_directory) {
+                        r = log_oom();
+                        goto finish;
+                }
+
+                r = loop_device_make_by_path(
+                                arg_image,
+                                arg_read_only ? O_RDONLY : O_RDWR,
+                                FLAGS_SET(dissect_image_flags, DISSECT_IMAGE_NO_PARTITION_TABLE) ? 0 : LO_FLAGS_PARTSCAN,
+                                &loop);
+                if (r < 0) {
+                        log_error_errno(r, "Failed to set up loopback block device: %m");
+                        goto finish;
+                }
+
+                r = dissect_image_and_warn(
+                                loop->fd,
+                                arg_image,
+                                &arg_verity_settings,
+                                NULL,
+                                dissect_image_flags,
+                                &dissected_image);
+                if (r == -ENOPKG) {
+                        /* dissected_image_and_warn() already printed a brief error message. Extend on that with more details */
+                        log_notice("Note that the disk image needs to\n"
+                                   "    a) either contain only a single MBR partition of type 0x83 that is marked bootable\n"
+                                   "    b) or contain a single GPT partition of type 0FC63DAF-8483-4772-8E79-3D69D8477DE4\n"
+                                   "    c) or follow https://systemd.io/DISCOVERABLE_PARTITIONS\n"
+                                   "    d) or contain a file system without a partition table\n"
+                                   "in order to be bootable with systemd-nspawn.");
+                        goto finish;
+                }
+                if (r < 0)
+                        goto finish;
+
+                if (!arg_verity_settings.root_hash && dissected_image->can_verity)
+                        log_notice("Note: image %s contains verity information, but no root hash specified! Proceeding without integrity checking.", arg_image);
+
+                r = dissected_image_decrypt_interactively(
+                                dissected_image,
+                                NULL,
+                                &arg_verity_settings,
+                                0,
+                                &decrypted_image);
+                if (r < 0)
+                        goto finish;
+
+                /* Now that we mounted the image, let's try to remove it again, if it is ephemeral */
+                if (remove_image && unlink(arg_image) >= 0)
+                        remove_image = false;
+        }
+
+        r = custom_mount_prepare_all(arg_directory, arg_custom_mounts, arg_n_custom_mounts);
+        if (r < 0)
+                goto finish;
+
+        if (arg_console_mode < 0)
+                arg_console_mode =
+                        isatty(STDIN_FILENO) > 0 &&
+                        isatty(STDOUT_FILENO) > 0 ? CONSOLE_INTERACTIVE : CONSOLE_READ_ONLY;
+
+        if (arg_console_mode == CONSOLE_PIPE) /* if we pass STDERR on to the container, don't add our own logs into it too */
+                arg_quiet = true;
+
+        if (!arg_quiet)
+                log_info("Spawning container %s on %s.\nPress ^] three times within 1s to kill container.",
+                         arg_machine, arg_image ?: arg_directory);
+
+        assert_se(sigprocmask_many(SIG_BLOCK, NULL, SIGCHLD, SIGWINCH, SIGTERM, SIGINT, -1) >= 0);
+
+        if (prctl(PR_SET_CHILD_SUBREAPER, 1, 0, 0, 0) < 0) {
+                r = log_error_errno(errno, "Failed to become subreaper: %m");
+                goto finish;
+        }
+
+        for (;;) {
+                r = run_container(dissected_image,
+                                  secondary,
+                                  fds,
+                                  veth_name, &veth_created,
+                                  &exposed, &master,
+                                  &pid, &ret);
+                if (r <= 0)
+                        break;
+        }
+
+finish:
+        (void) sd_notify(false,
+                         r == 0 && ret == EXIT_FORCE_RESTART ? "STOPPING=1\nSTATUS=Restarting..." :
+                                                               "STOPPING=1\nSTATUS=Terminating...");
+
+        if (pid > 0)
+                (void) 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, 0);
+                master = safe_close(master);
+        }
+
+        if (pid > 0)
+                (void) wait_for_terminate(pid, NULL);
+
+        pager_close();
+
+        if (remove_directory && arg_directory) {
+                int k;
+
+                k = rm_rf(arg_directory, REMOVE_ROOT|REMOVE_PHYSICAL|REMOVE_SUBVOLUME);
+                if (k < 0)
+                        log_warning_errno(k, "Cannot remove '%s', ignoring: %m", arg_directory);
+        }
+
+        if (remove_image && arg_image) {
+                if (unlink(arg_image) < 0)
+                        log_warning_errno(errno, "Can't remove image file '%s', ignoring: %m", arg_image);
+        }
+
+        if (remove_tmprootdir) {
+                if (rmdir(tmprootdir) < 0)
+                        log_debug_errno(errno, "Can't remove temporary root directory '%s', ignoring: %m", tmprootdir);
+        }
+
+        if (arg_machine) {
+                const char *p;
+
+                p = strjoina("/run/systemd/nspawn/propagate/", arg_machine);
+                (void) rm_rf(p, REMOVE_ROOT);
+        }
+
+        expose_port_flush(arg_expose_ports, &exposed);
+
+        if (veth_created)
+                (void) remove_veth_links(veth_name, arg_network_veth_extra);
+        (void) remove_bridge(arg_network_zone);
+
+        custom_mount_free_all(arg_custom_mounts, arg_n_custom_mounts);
+        expose_port_free_all(arg_expose_ports);
+        rlimit_free_all(arg_rlimit);
+        device_node_array_free(arg_extra_nodes, arg_n_extra_nodes);
+        credential_free_all(arg_credentials, arg_n_credentials);
+
+        if (r < 0)
+                return r;
+
+        return ret;
+}
+
+DEFINE_MAIN_FUNCTION_WITH_POSITIVE_FAILURE(run);