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/* SPDX-License-Identifier: LGPL-2.1+ */
#if HAVE_BLKID
#include <blkid.h>
#endif
#include <errno.h>
#include <getopt.h>
#include <grp.h>
#include <linux/loop.h>
#include <pwd.h>
#include <sched.h>
#if HAVE_SELINUX
#include <selinux/selinux.h>
#endif
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/file.h>
#include <sys/mount.h>
#include <sys/personality.h>
#include <sys/prctl.h>
#include <sys/types.h>
#include <sys/wait.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 "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 "log.h"
#include "loop-util.h"
#include "loopback-setup.h"
#include "machine-image.h"
#include "macro.h"
#include "missing.h"
#include "mkdir.h"
#include "mount-util.h"
#include "netlink-util.h"
#include "nspawn-cgroup.h"
#include "nspawn-def.h"
#include "nspawn-expose-ports.h"
#include "nspawn-mount.h"
#include "nspawn-network.h"
#include "nspawn-patch-uid.h"
#include "nspawn-register.h"
#include "nspawn-seccomp.h"
#include "nspawn-settings.h"
#include "nspawn-setuid.h"
#include "nspawn-stub-pid1.h"
#include "os-util.h"
#include "pager.h"
#include "parse-util.h"
#include "path-util.h"
#include "process-util.h"
#include "ptyfwd.h"
#include "random-util.h"
#include "raw-clone.h"
#include "rlimit-util.h"
#include "rm-rf.h"
#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 "terminal-util.h"
#include "umask-util.h"
#include "user-util.h"
#include "util.h"
#if HAVE_SPLIT_USR
#define STATIC_RESOLV_CONF "/lib/systemd/resolv.conf"
#else
#define STATIC_RESOLV_CONF "/usr/lib/systemd/resolv.conf"
#endif
/* nspawn is listening on the socket at the path in the constant nspawn_notify_socket_path
* nspawn_notify_socket_path is relative to the container
* the init process in the container pid can send messages to nspawn following the sd_notify(3) protocol */
#define NSPAWN_NOTIFY_SOCKET_PATH "/run/systemd/nspawn/notify"
#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 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 const char *arg_slice = NULL;
static bool arg_private_network = false;
static bool arg_read_only = false;
static StartMode arg_start_mode = START_PID1;
static bool arg_ephemeral = false;
static LinkJournal arg_link_journal = LINK_AUTO;
static bool arg_link_journal_try = false;
static uint64_t arg_caps_retain =
(1ULL << CAP_AUDIT_CONTROL) |
(1ULL << CAP_AUDIT_WRITE) |
(1ULL << CAP_CHOWN) |
(1ULL << CAP_DAC_OVERRIDE) |
(1ULL << CAP_DAC_READ_SEARCH) |
(1ULL << CAP_FOWNER) |
(1ULL << CAP_FSETID) |
(1ULL << CAP_IPC_OWNER) |
(1ULL << CAP_KILL) |
(1ULL << CAP_LEASE) |
(1ULL << CAP_LINUX_IMMUTABLE) |
(1ULL << CAP_MKNOD) |
(1ULL << CAP_NET_BIND_SERVICE) |
(1ULL << CAP_NET_BROADCAST) |
(1ULL << CAP_NET_RAW) |
(1ULL << CAP_SETFCAP) |
(1ULL << CAP_SETGID) |
(1ULL << CAP_SETPCAP) |
(1ULL << CAP_SETUID) |
(1ULL << CAP_SYS_ADMIN) |
(1ULL << CAP_SYS_BOOT) |
(1ULL << CAP_SYS_CHROOT) |
(1ULL << CAP_SYS_NICE) |
(1ULL << CAP_SYS_PTRACE) |
(1ULL << CAP_SYS_RESOURCE) |
(1ULL << CAP_SYS_TTY_CONFIG);
static CustomMount *arg_custom_mounts = NULL;
static 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 unsigned long arg_personality = PERSONALITY_INVALID;
static char *arg_image = NULL;
static VolatileMode arg_volatile_mode = VOLATILE_NO;
static ExposePort *arg_expose_ports = NULL;
static char **arg_property = NULL;
static UserNamespaceMode arg_userns_mode = USER_NAMESPACE_NO;
static uid_t arg_uid_shift = UID_INVALID, arg_uid_range = 0x10000U;
static bool arg_userns_chown = false;
static int arg_kill_signal = 0;
static CGroupUnified arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_UNKNOWN;
static SettingsMask arg_settings_mask = 0;
static int arg_settings_trusted = -1;
static char **arg_parameters = NULL;
static const char *arg_container_service_name = "systemd-nspawn";
static bool arg_notify_ready = false;
static bool arg_use_cgns = true;
static unsigned long arg_clone_ns_flags = CLONE_NEWIPC|CLONE_NEWPID|CLONE_NEWUTS;
static MountSettingsMask arg_mount_settings = MOUNT_APPLY_APIVFS_RO;
static void *arg_root_hash = NULL;
static size_t arg_root_hash_size = 0;
static char **arg_syscall_whitelist = NULL;
static char **arg_syscall_blacklist = NULL;
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 cpu_set_t *arg_cpuset = NULL;
static unsigned arg_cpuset_ncpus = 0;
static ResolvConfMode arg_resolv_conf = RESOLV_CONF_AUTO;
static TimezoneMode arg_timezone = TIMEZONE_AUTO;
static int help(void) {
_cleanup_free_ char *link = NULL;
int r;
(void) pager_open(false, false);
r = terminal_urlify_man("systemd-nspawn", "1", &link);
if (r < 0)
return log_oom();
printf("%s [OPTIONS...] [PATH] [ARGUMENTS...]\n\n"
"Spawn a command or OS in a light-weight container.\n\n"
" -h --help Show this help\n"
" --version Print version string\n"
" -q --quiet Do not show status information\n"
" -D --directory=PATH Root directory for the container\n"
" --template=PATH Initialize root directory from template directory,\n"
" if missing\n"
" -x --ephemeral Run container with snapshot of root directory, and\n"
" remove it after exit\n"
" -i --image=PATH File system device or disk image for the container\n"
" --root-hash=HASH Specify verity root hash\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"
" --pivot-root=PATH[:PATH]\n"
" Pivot root to given directory in the container\n"
" -u --user=USER Run the command under specified user or uid\n"
" -M --machine=NAME Set the machine name for the container\n"
" --hostname=NAME Override the hostname for the container\n"
" --uuid=UUID Set a specific machine UUID for the container\n"
" -S --slice=SLICE Place the container in the specified slice\n"
" --property=NAME=VALUE Set scope unit property\n"
" -U --private-users=pick Run within user namespace, autoselect UID/GID range\n"
" --private-users[=UIDBASE[:NUIDS]]\n"
" Similar, but with user configured UID/GID range\n"
" --private-users-chown Adjust OS tree ownership to private UID/GID range\n"
" --private-network Disable network in container\n"
" --network-interface=INTERFACE\n"
" Assign an existing network interface to the\n"
" container\n"
" --network-macvlan=INTERFACE\n"
" Create a macvlan network interface based on an\n"
" existing network interface to the container\n"
" --network-ipvlan=INTERFACE\n"
" Create a ipvlan network interface based on an\n"
" existing network interface to the container\n"
" -n --network-veth Add a virtual Ethernet connection between host\n"
" and container\n"
" --network-veth-extra=HOSTIF[:CONTAINERIF]\n"
" Add an additional virtual Ethernet link between\n"
" host and container\n"
" --network-bridge=INTERFACE\n"
" Add a virtual Ethernet connection to the container\n"
" and attach it to an existing bridge on the host\n"
" --network-zone=NAME Similar, but attach the new interface to an\n"
" an automatically managed bridge interface\n"
" --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"
" -Z --selinux-context=SECLABEL\n"
" Set the SELinux security context to be used by\n"
" processes in the container\n"
" -L --selinux-apifs-context=SECLABEL\n"
" Set the SELinux security context to be used by\n"
" API/tmpfs file systems in the container\n"
" --capability=CAP In addition to the default, retain specified\n"
" capability\n"
" --drop-capability=CAP Drop the specified capability from the default set\n"
" --system-call-filter=LIST|~LIST\n"
" Permit/prohibit specific system calls\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"
" --kill-signal=SIGNAL Select signal to use for shutting down PID 1\n"
" --link-journal=MODE Link up guest journal, one of no, auto, guest, \n"
" host, try-guest, try-host\n"
" -j Equivalent to --link-journal=try-guest\n"
" --resolv-conf=MODE Select mode of /etc/resolv.conf initialization\n"
" --timezone=MODE Select mode of /etc/localtime initialization\n"
" --read-only Mount the root directory read-only\n"
" --bind=PATH[:PATH[:OPTIONS]]\n"
" Bind mount a file or directory from the host into\n"
" the container\n"
" --bind-ro=PATH[:PATH[:OPTIONS]\n"
" Similar, but creates a read-only bind mount\n"
" --tmpfs=PATH:[OPTIONS] Mount an empty tmpfs to the specified directory\n"
" --overlay=PATH[:PATH...]:PATH\n"
" Create an overlay mount from the host to \n"
" the container\n"
" --overlay-ro=PATH[:PATH...]:PATH\n"
" Similar, but creates a read-only overlay mount\n"
" -E --setenv=NAME=VALUE Pass an environment variable to PID 1\n"
" --register=BOOLEAN Register container as machine\n"
" --keep-unit Do not register a scope for the machine, reuse\n"
" the service unit nspawn is running in\n"
" --volatile[=MODE] Run the system in volatile mode\n"
" --settings=BOOLEAN Load additional settings from .nspawn file\n"
" --notify-ready=BOOLEAN Receive notifications from the child init process\n"
"\nSee the %s for details.\n"
, program_invocation_short_name
, link
);
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) {
log_error("--private-users-chown may not be combined with custom root mounts.");
return -EINVAL;
} else if (arg_uid_shift == UID_INVALID) {
log_error("--private-users with automatic UID shift may not be combined with custom root mounts.");
return -EINVAL;
}
}
}
return 0;
}
static int detect_unified_cgroup_hierarchy_from_environment(void) {
const char *e;
int r;
/* Allow the user to control whether the unified hierarchy is used */
e = getenv("UNIFIED_CGROUP_HIERARCHY");
if (e) {
r = parse_boolean(e);
if (r < 0)
return log_error_errno(r, "Failed to parse $UNIFIED_CGROUP_HIERARCHY.");
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 void parse_share_ns_env(const char *name, unsigned long ns_flag) {
int r;
r = getenv_bool(name);
if (r == -ENXIO)
return;
if (r < 0)
log_warning_errno(r, "Failed to parse %s from environment, defaulting to false.", name);
arg_clone_ns_flags = (arg_clone_ns_flags & ~ns_flag) | (r > 0 ? 0 : ns_flag);
}
static void parse_mount_settings_env(void) {
int r;
const char *e;
e = getenv("SYSTEMD_NSPAWN_API_VFS_WRITABLE");
if (!e)
return;
if (streq(e, "network")) {
arg_mount_settings |= MOUNT_APPLY_APIVFS_RO|MOUNT_APPLY_APIVFS_NETNS;
return;
}
r = parse_boolean(e);
if (r < 0) {
log_warning_errno(r, "Failed to parse SYSTEMD_NSPAWN_API_VFS_WRITABLE from environment, ignoring.");
return;
}
SET_FLAG(arg_mount_settings, MOUNT_APPLY_APIVFS_RO, r == 0);
SET_FLAG(arg_mount_settings, MOUNT_APPLY_APIVFS_NETNS, false);
}
static int parse_argv(int argc, char *argv[]) {
enum {
ARG_VERSION = 0x100,
ARG_PRIVATE_NETWORK,
ARG_UUID,
ARG_READ_ONLY,
ARG_CAPABILITY,
ARG_DROP_CAPABILITY,
ARG_LINK_JOURNAL,
ARG_BIND,
ARG_BIND_RO,
ARG_TMPFS,
ARG_OVERLAY,
ARG_OVERLAY_RO,
ARG_SHARE_SYSTEM,
ARG_REGISTER,
ARG_KEEP_UNIT,
ARG_NETWORK_INTERFACE,
ARG_NETWORK_MACVLAN,
ARG_NETWORK_IPVLAN,
ARG_NETWORK_BRIDGE,
ARG_NETWORK_ZONE,
ARG_NETWORK_VETH_EXTRA,
ARG_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_SYSTEM_CALL_FILTER,
ARG_RLIMIT,
ARG_HOSTNAME,
ARG_NO_NEW_PRIVILEGES,
ARG_OOM_SCORE_ADJUST,
ARG_CPU_AFFINITY,
ARG_RESOLV_CONF,
ARG_TIMEZONE,
};
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 },
{ "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 },
{ "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 },
{}
};
int c, r;
const char *p, *e;
uint64_t plus = 0, minus = 0;
bool mask_all_settings = false, mask_no_settings = false;
assert(argc >= 0);
assert(argv);
while ((c = getopt_long(argc, argv, "+hD:u:abL:M:jS:Z:qi:xp:nUE:", 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;
break;
case ARG_TEMPLATE:
r = parse_path_argument_and_warn(optarg, false, &arg_template);
if (r < 0)
return r;
break;
case 'i':
r = parse_path_argument_and_warn(optarg, false, &arg_image);
if (r < 0)
return r;
break;
case 'x':
arg_ephemeral = true;
break;
case 'u':
r = free_and_strdup(&arg_user, optarg);
if (r < 0)
return log_oom();
arg_settings_mask |= SETTING_USER;
break;
case ARG_NETWORK_ZONE: {
char *j;
j = strappend("vz-", optarg);
if (!j)
return log_oom();
if (!ifname_valid(j)) {
log_error("Network zone name not valid: %s", j);
free(j);
return -EINVAL;
}
free_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)) {
log_error("Bridge interface name not valid: %s", optarg);
return -EINVAL;
}
r = free_and_strdup(&arg_network_bridge, optarg);
if (r < 0)
return log_oom();
_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)) {
log_error("Network interface name not valid: %s", optarg);
return -EINVAL;
}
if (strv_extend(&arg_network_interfaces, optarg) < 0)
return log_oom();
arg_private_network = true;
arg_settings_mask |= SETTING_NETWORK;
break;
case ARG_NETWORK_MACVLAN:
if (!ifname_valid(optarg)) {
log_error("MACVLAN network interface name not valid: %s", optarg);
return -EINVAL;
}
if (strv_extend(&arg_network_macvlan, optarg) < 0)
return log_oom();
arg_private_network = true;
arg_settings_mask |= SETTING_NETWORK;
break;
case ARG_NETWORK_IPVLAN:
if (!ifname_valid(optarg)) {
log_error("IPVLAN network interface name not valid: %s", optarg);
return -EINVAL;
}
if (strv_extend(&arg_network_ipvlan, optarg) < 0)
return log_oom();
_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;
break;
case 'b':
if (arg_start_mode == START_PID2) {
log_error("--boot and --as-pid2 may not be combined.");
return -EINVAL;
}
arg_start_mode = START_BOOT;
arg_settings_mask |= SETTING_START_MODE;
break;
case 'a':
if (arg_start_mode == START_BOOT) {
log_error("--boot and --as-pid2 may not be combined.");
return -EINVAL;
}
arg_start_mode = START_PID2;
arg_settings_mask |= SETTING_START_MODE;
break;
case ARG_UUID:
r = sd_id128_from_string(optarg, &arg_uuid);
if (r < 0)
return log_error_errno(r, "Invalid UUID: %s", optarg);
if (sd_id128_is_null(arg_uuid)) {
log_error("Machine UUID may not be all zeroes.");
return -EINVAL;
}
arg_settings_mask |= SETTING_MACHINE_ID;
break;
case 'S':
arg_slice = optarg;
break;
case 'M':
if (isempty(optarg))
arg_machine = mfree(arg_machine);
else {
if (!machine_name_is_valid(optarg)) {
log_error("Invalid machine name: %s", optarg);
return -EINVAL;
}
r = free_and_strdup(&arg_machine, optarg);
if (r < 0)
return log_oom();
}
break;
case ARG_HOSTNAME:
if (isempty(optarg))
arg_hostname = mfree(arg_hostname);
else {
if (!hostname_is_valid(optarg, false)) {
log_error("Invalid hostname: %s", optarg);
return -EINVAL;
}
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: {
p = optarg;
for (;;) {
_cleanup_free_ char *t = NULL;
r = extract_first_word(&p, &t, ",", 0);
if (r < 0)
return log_error_errno(r, "Failed to parse capability %s.", t);
if (r == 0)
break;
if (streq(t, "all")) {
if (c == ARG_CAPABILITY)
plus = (uint64_t) -1;
else
minus = (uint64_t) -1;
} else {
int cap;
cap = capability_from_name(t);
if (cap < 0) {
log_error("Failed to parse capability %s.", t);
return -EINVAL;
}
if (c == ARG_CAPABILITY)
plus |= 1ULL << (uint64_t) cap;
else
minus |= 1ULL << (uint64_t) cap;
}
}
arg_settings_mask |= SETTING_CAPABILITY;
break;
}
case 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) {
log_error_errno(r, "Failed to parse link journal mode %s", optarg);
return -EINVAL;
}
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 'E': {
char **n;
if (!env_assignment_is_valid(optarg)) {
log_error("Environment variable assignment '%s' is not valid.", optarg);
return -EINVAL;
}
n = strv_env_set(arg_setenv, optarg);
if (!n)
return log_oom();
strv_free_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) {
log_error("Unknown or unsupported personality '%s'.", optarg);
return -EINVAL;
}
arg_settings_mask |= SETTING_PERSONALITY;
break;
case ARG_VOLATILE:
if (!optarg)
arg_volatile_mode = VOLATILE_YES;
else 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) {
log_error("Failed to parse --volatile= argument: %s", optarg);
return -EINVAL;
} else
arg_volatile_mode = m;
}
arg_settings_mask |= SETTING_VOLATILE_MODE;
break;
case 'p':
r = expose_port_parse(&arg_expose_ports, optarg);
if (r == -EEXIST)
return log_error_errno(r, "Duplicate port specification: %s", optarg);
if (r < 0)
return log_error_errno(r, "Failed to parse host port %s: %m", optarg);
arg_settings_mask |= SETTING_EXPOSE_PORTS;
break;
case ARG_PROPERTY:
if (strv_extend(&arg_property, optarg) < 0)
return log_oom();
break;
case ARG_PRIVATE_USERS: {
int boolean = -1;
if (!optarg)
boolean = true;
else if (!in_charset(optarg, DIGITS))
/* do *not* parse numbers as booleans */
boolean = parse_boolean(optarg);
if (boolean == false) {
/* no: User namespacing off */
arg_userns_mode = USER_NAMESPACE_NO;
arg_uid_shift = UID_INVALID;
arg_uid_range = UINT32_C(0x10000);
} else if (boolean == true) {
/* yes: User namespacing on, UID range is read from root dir */
arg_userns_mode = USER_NAMESPACE_FIXED;
arg_uid_shift = UID_INVALID;
arg_uid_range = UINT32_C(0x10000);
} else if (streq(optarg, "pick")) {
/* pick: User namespacing on, UID range is picked randomly */
arg_userns_mode = USER_NAMESPACE_PICK;
arg_uid_shift = UID_INVALID;
arg_uid_range = UINT32_C(0x10000);
} else {
_cleanup_free_ char *buffer = NULL;
const char *range, *shift;
/* anything else: User namespacing on, UID range is explicitly configured */
range = strchr(optarg, ':');
if (range) {
buffer = strndup(optarg, range - optarg);
if (!buffer)
return log_oom();
shift = buffer;
range++;
r = safe_atou32(range, &arg_uid_range);
if (r < 0)
return log_error_errno(r, "Failed to parse UID range \"%s\": %m", range);
} else
shift = optarg;
r = parse_uid(shift, &arg_uid_shift);
if (r < 0)
return log_error_errno(r, "Failed to parse UID \"%s\": %m", optarg);
arg_userns_mode = USER_NAMESPACE_FIXED;
}
if (arg_uid_range <= 0) {
log_error("UID range cannot be 0.");
return -EINVAL;
}
arg_settings_mask |= SETTING_USERNS;
break;
}
case 'U':
if (userns_supported()) {
arg_userns_mode = USER_NAMESPACE_PICK;
arg_uid_shift = UID_INVALID;
arg_uid_range = UINT32_C(0x10000);
arg_settings_mask |= SETTING_USERNS;
}
break;
case ARG_PRIVATE_USERS_CHOWN:
arg_userns_chown = true;
arg_settings_mask |= SETTING_USERNS;
break;
case ARG_KILL_SIGNAL:
if (streq(optarg, "help")) {
DUMP_STRING_TABLE(signal, int, _NSIG);
return 0;
}
arg_kill_signal = signal_from_string(optarg);
if (arg_kill_signal < 0) {
log_error("Cannot parse signal: %s", optarg);
return -EINVAL;
}
arg_settings_mask |= SETTING_KILL_SIGNAL;
break;
case ARG_SETTINGS:
/* no β†’ do not read files
* yes β†’ read files, do not override cmdline, trust only subset
* override β†’ read files, override cmdline, trust only subset
* trusted β†’ read files, do not override cmdline, trust all
*/
r = parse_boolean(optarg);
if (r < 0) {
if (streq(optarg, "trusted")) {
mask_all_settings = false;
mask_no_settings = false;
arg_settings_trusted = true;
} else if (streq(optarg, "override")) {
mask_all_settings = false;
mask_no_settings = true;
arg_settings_trusted = -1;
} else
return log_error_errno(r, "Failed to parse --settings= argument: %s", optarg);
} else if (r > 0) {
/* yes */
mask_all_settings = false;
mask_no_settings = false;
arg_settings_trusted = -1;
} else {
/* no */
mask_all_settings = true;
mask_no_settings = false;
arg_settings_trusted = false;
}
break;
case ARG_CHDIR:
if (!path_is_absolute(optarg)) {
log_error("Working directory %s is not an absolute path.", optarg);
return -EINVAL;
}
r = free_and_strdup(&arg_chdir, optarg);
if (r < 0)
return log_oom();
arg_settings_mask |= SETTING_WORKING_DIRECTORY;
break;
case ARG_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) {
log_error("%s is not a valid notify mode. Valid modes are: yes, no, and ready.", optarg);
return -EINVAL;
}
arg_notify_ready = r;
arg_settings_mask |= SETTING_NOTIFY_READY;
break;
case ARG_ROOT_HASH: {
void *k;
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)) {
log_error("Root hash must be at least 128bit long: %s", optarg);
free(k);
return -EINVAL;
}
free(arg_root_hash);
arg_root_hash = k;
arg_root_hash_size = l;
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_blacklist, word);
else
r = strv_extend(&arg_syscall_whitelist, word);
if (r < 0)
return log_oom();
}
arg_settings_mask |= SETTING_SYSCALL_FILTER;
break;
}
case ARG_RLIMIT: {
const char *eq;
char *name;
int rl;
if (streq(optarg, "help")) {
DUMP_STRING_TABLE(rlimit, int, _RLIMIT_MAX);
return 0;
}
eq = strchr(optarg, '=');
if (!eq) {
log_error("--rlimit= expects an '=' assignment.");
return -EINVAL;
}
name = strndup(optarg, eq - optarg);
if (!name)
return log_oom();
rl = rlimit_from_string_harder(name);
if (rl < 0) {
log_error("Unknown resource limit: %s", name);
return -EINVAL;
}
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: {
_cleanup_cpu_free_ cpu_set_t *cpuset = NULL;
r = parse_cpu_set(optarg, &cpuset);
if (r < 0)
return log_error_errno(r, "Failed to parse CPU affinity mask: %s", optarg);
if (arg_cpuset)
CPU_FREE(arg_cpuset);
arg_cpuset = TAKE_PTR(cpuset);
arg_cpuset_ncpus = r;
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) {
log_error("Failed to parse /etc/resolv.conf mode: %s", optarg);
return -EINVAL;
}
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) {
log_error("Failed to parse /etc/localtime mode: %s", optarg);
return -EINVAL;
}
arg_settings_mask |= SETTING_TIMEZONE;
break;
case '?':
return -EINVAL;
default:
assert_not_reached("Unhandled option");
}
/* If --network-namespace-path is given with any other network-related option,
* 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 || arg_private_network)) {
log_error("--network-namespace-path cannot be combined with other network options.");
return -EINVAL;
}
parse_share_ns_env("SYSTEMD_NSPAWN_SHARE_NS_IPC", CLONE_NEWIPC);
parse_share_ns_env("SYSTEMD_NSPAWN_SHARE_NS_PID", CLONE_NEWPID);
parse_share_ns_env("SYSTEMD_NSPAWN_SHARE_NS_UTS", CLONE_NEWUTS);
parse_share_ns_env("SYSTEMD_NSPAWN_SHARE_SYSTEM", CLONE_NEWIPC|CLONE_NEWPID|CLONE_NEWUTS);
if (arg_userns_mode != USER_NAMESPACE_NO)
arg_mount_settings |= MOUNT_USE_USERNS;
if (arg_private_network)
arg_mount_settings |= MOUNT_APPLY_APIVFS_NETNS;
parse_mount_settings_env();
if (!(arg_clone_ns_flags & CLONE_NEWPID) ||
!(arg_clone_ns_flags & CLONE_NEWUTS)) {
arg_register = false;
if (arg_start_mode != START_PID1) {
log_error("--boot cannot be used without namespacing.");
return -EINVAL;
}
}
if (arg_userns_mode == USER_NAMESPACE_PICK)
arg_userns_chown = true;
if (arg_keep_unit && 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. */
log_error("--keep-unit --register=yes may not be used when invoked from a user session.");
return -EINVAL;
}
if (arg_directory && arg_image) {
log_error("--directory= and --image= may not be combined.");
return -EINVAL;
}
if (arg_template && arg_image) {
log_error("--template= and --image= may not be combined.");
return -EINVAL;
}
if (arg_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);
}
if (arg_template && !(arg_directory || arg_machine)) {
log_error("--template= needs --directory= or --machine=.");
return -EINVAL;
}
if (arg_ephemeral && arg_template) {
log_error("--ephemeral and --template= may not be combined.");
return -EINVAL;
}
if (arg_ephemeral && !IN_SET(arg_link_journal, LINK_NO, LINK_AUTO)) {
log_error("--ephemeral and --link-journal= may not be combined.");
return -EINVAL;
}
if (arg_userns_mode != USER_NAMESPACE_NO && !userns_supported()) {
log_error("--private-users= is not supported, kernel compiled without user namespace support.");
return -EOPNOTSUPP;
}
if (arg_userns_chown && arg_read_only) {
log_error("--read-only and --private-users-chown may not be combined.");
return -EINVAL;
}
if (arg_network_bridge && arg_network_zone) {
log_error("--network-bridge= and --network-zone= may not be combined.");
return -EINVAL;
}
if (argc > optind) {
arg_parameters = strv_copy(argv + optind);
if (!arg_parameters)
return log_oom();
arg_settings_mask |= SETTING_START_MODE;
}
/* Load all settings from .nspawn files */
if (mask_no_settings)
arg_settings_mask = 0;
/* Don't load any settings from .nspawn files */
if (mask_all_settings)
arg_settings_mask = _SETTINGS_MASK_ALL;
arg_caps_retain = (arg_caps_retain | plus | (arg_private_network ? 1ULL << CAP_NET_ADMIN : 0)) & ~minus;
r = cg_unified_flush();
if (r < 0)
return log_error_errno(r, "Failed to determine whether the unified cgroups hierarchy is used: %m");
e = getenv("SYSTEMD_NSPAWN_CONTAINER_SERVICE");
if (e)
arg_container_service_name = e;
r = getenv_bool("SYSTEMD_NSPAWN_USE_CGNS");
if (r < 0)
arg_use_cgns = cg_ns_supported();
else
arg_use_cgns = r;
r = custom_mount_check_all();
if (r < 0)
return r;
return 1;
}
static int verify_arguments(void) {
if (arg_userns_mode != USER_NAMESPACE_NO && (arg_mount_settings & MOUNT_APPLY_APIVFS_NETNS) && !arg_private_network) {
log_error("Invalid namespacing settings. Mounting sysfs with --private-users requires --private-network.");
return -EINVAL;
}
if (arg_userns_mode != USER_NAMESPACE_NO && !(arg_mount_settings & MOUNT_APPLY_APIVFS_RO)) {
log_error("Cannot combine --private-users with read-write mounts.");
return -EINVAL;
}
if (arg_volatile_mode != VOLATILE_NO && arg_read_only) {
log_error("Cannot combine --read-only with --volatile. Note that --volatile already implies a read-only base hierarchy.");
return -EINVAL;
}
if (arg_expose_ports && !arg_private_network) {
log_error("Cannot use --port= without private networking.");
return -EINVAL;
}
#if ! HAVE_LIBIPTC
if (arg_expose_ports) {
log_error("--port= is not supported, compiled without libiptc support.");
return -EOPNOTSUPP;
}
#endif
if (arg_start_mode == START_BOOT && arg_kill_signal <= 0)
arg_kill_signal = SIGRTMIN+3;
return 0;
}
static int userns_lchown(const char *p, uid_t uid, gid_t gid) {
assert(p);
if (arg_userns_mode == USER_NAMESPACE_NO)
return 0;
if (uid == UID_INVALID && gid == GID_INVALID)
return 0;
if (uid != UID_INVALID) {
uid += arg_uid_shift;
if (uid < arg_uid_shift || uid >= arg_uid_shift + arg_uid_range)
return -EOVERFLOW;
}
if (gid != GID_INVALID) {
gid += (gid_t) arg_uid_shift;
if (gid < (gid_t) arg_uid_shift || gid >= (gid_t) (arg_uid_shift + arg_uid_range))
return -EOVERFLOW;
}
if (lchown(p, uid, gid) < 0)
return -errno;
return 0;
}
static int userns_mkdir(const char *root, const char *path, mode_t mode, uid_t uid, gid_t gid) {
const char *q;
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) {
const char *z;
z = path_startswith(path, "../usr/share/zoneinfo/");
if (z)
return z;
z = path_startswith(path, "/usr/share/zoneinfo/");
if (z)
return z;
return NULL;
}
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 = arg_read_only && arg_volatile_mode != VOLATILE_YES ? TIMEZONE_OFF : TIMEZONE_DELETE;
else if (r == -EINVAL && arg_timezone == TIMEZONE_AUTO) /* regular file? */
m = arg_read_only && arg_volatile_mode != VOLATILE_YES ? TIMEZONE_BIND : TIMEZONE_COPY;
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 = arg_read_only && arg_volatile_mode != VOLATILE_YES ? TIMEZONE_BIND : TIMEZONE_SYMLINK;
else
m = arg_timezone;
} else
m = arg_timezone;
if (m == TIMEZONE_OFF)
return 0;
r = chase_symlinks("/etc", dest, CHASE_PREFIX_ROOT, &etc);
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);
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);
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_verbose(LOG_WARNING, "/etc/localtime", resolved, NULL, MS_BIND, NULL);
if (r >= 0)
return mount_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, 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(STATIC_RESOLV_CONF) > 0 && resolved_listening() > 0)
m = arg_read_only && arg_volatile_mode != VOLATILE_YES ? RESOLV_CONF_BIND_STATIC : RESOLV_CONF_COPY_STATIC;
else if (have_resolv_conf("/etc/resolv.conf") > 0)
m = arg_read_only && arg_volatile_mode != VOLATILE_YES ? RESOLV_CONF_BIND_HOST : RESOLV_CONF_COPY_HOST;
else
m = arg_read_only && arg_volatile_mode != VOLATILE_YES ? RESOLV_CONF_OFF : RESOLV_CONF_DELETE;
} else
m = arg_resolv_conf;
if (m == RESOLV_CONF_OFF)
return 0;
r = chase_symlinks("/etc", dest, CHASE_PREFIX_ROOT, &etc);
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_COPY_STATIC))
what = STATIC_RESOLV_CONF;
else
what = "/etc/resolv.conf";
if (IN_SET(m, RESOLV_CONF_BIND_HOST, RESOLV_CONF_BIND_STATIC)) {
_cleanup_free_ char *resolved = NULL;
int found;
found = chase_symlinks(where, dest, CHASE_NONEXISTENT, &resolved);
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_verbose(LOG_WARNING, what, resolved, NULL, MS_BIND, NULL);
if (r >= 0)
return mount_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 */
r = copy_file(what, where, O_TRUNC|O_NOFOLLOW, 0644, 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) && 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(NULL, "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_verbose(LOG_ERR, from, to, NULL, MS_BIND, NULL);
if (r < 0)
return r;
return mount_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";
const char *d;
int r = 0;
_cleanup_umask_ mode_t u;
assert(dest);
u = umask(0000);
/* Create /dev/net, so that we can create /dev/net/tun in it */
if (userns_mkdir(dest, "/dev/net", 0755, 0, 0) < 0)
return log_error_errno(r, "Failed to create /dev/net directory: %m");
NULSTR_FOREACH(d, devnodes) {
_cleanup_free_ char *from = NULL, *to = NULL;
struct stat st;
from = strappend("/dev/", d);
if (!from)
return log_oom();
to = prefix_root(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)) {
log_error("%s is not a char or block device, cannot copy.", from);
return -EIO;
} 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_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 = strjoin("/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 = prefix_root(dest, sl);
if (!prefixed)
return log_oom();
t = strjoin("../", 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 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_verbose(LOG_ERR, "devpts", p, "devpts", MS_NOSUID|MS_NOEXEC, options);
if (r < 0)
return r;
r = userns_lchown(p, 0, 0);
if (r < 0)
return log_error_errno(r, "Failed to chown /dev/pts: %m");
/* Create /dev/ptmx symlink */
p = prefix_roota(dest, "/dev/ptmx");
if (symlink("pts/ptmx", p) < 0)
return log_error_errno(errno, "Failed to create /dev/ptmx symlink: %m");
r = userns_lchown(p, 0, 0);
if (r < 0)
return log_error_errno(r, "Failed to chown /dev/ptmx: %m");
/* And fix /dev/pts/ptmx ownership */
p = prefix_roota(dest, "/dev/pts/ptmx");
r = userns_lchown(p, 0, 0);
if (r < 0)
return log_error_errno(r, "Failed to chown /dev/pts/ptmx: %m");
return 0;
}
static int setup_dev_console(const char *dest, const char *console) {
_cleanup_umask_ mode_t u;
const char *to;
int r;
assert(dest);
assert(console);
u = umask(0000);
r = chmod_and_chown(console, 0600, arg_uid_shift, arg_uid_shift);
if (r < 0)
return log_error_errno(r, "Failed to correct access mode for TTY: %m");
/* We need to bind mount the right tty to /dev/console since
* ptys can only exist on pts file systems. To have something
* to bind mount things on we create a empty regular file. */
to = prefix_roota(dest, "/dev/console");
r = touch(to);
if (r < 0)
return log_error_errno(r, "touch() for /dev/console failed: %m");
return mount_verbose(LOG_ERR, console, to, NULL, MS_BIND, NULL);
}
static int setup_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 whitelist
* 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 (IN_SET(errno, EACCES, EPERM))
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_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;
const char *to;
int r;
assert(kmsg_socket >= 0);
u = umask(0000);
/* We create the kmsg FIFO as as temporary file in /tmp, 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(NULL, "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);
to = "/proc/kmsg";
r = mount_verbose(LOG_ERR, from, to, 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) {
sd_id128_t this_id;
_cleanup_free_ char *d = NULL;
const char *p, *q;
bool try;
char id[33];
int r;
/* Don't link journals in ephemeral mode */
if (arg_ephemeral)
return 0;
if (arg_link_journal == LINK_NO)
return 0;
try = arg_link_journal_try || arg_link_journal == LINK_AUTO;
r = sd_id128_get_machine(&this_id);
if (r < 0)
return log_error_errno(r, "Failed to retrieve machine ID: %m");
if (sd_id128_equal(arg_uuid, this_id)) {
log_full(try ? LOG_WARNING : LOG_ERR,
"Host and machine ids are equal (%s): refusing to link journals", sd_id128_to_string(arg_uuid, id));
if (try)
return 0;
return -EEXIST;
}
r = userns_mkdir(directory, "/var", 0755, 0, 0);
if (r < 0)
return log_error_errno(r, "Failed to create /var: %m");
r = userns_mkdir(directory, "/var/log", 0755, 0, 0);
if (r < 0)
return log_error_errno(r, "Failed to create /var/log: %m");
r = userns_mkdir(directory, "/var/log/journal", 0755, 0, 0);
if (r < 0)
return log_error_errno(r, "Failed to create /var/log/journal: %m");
(void) sd_id128_to_string(arg_uuid, id);
p = strjoina("/var/log/journal/", id);
q = prefix_roota(directory, p);
if (path_is_mount_point(p, NULL, 0) > 0) {
if (try)
return 0;
log_error("%s: already a mount point, refusing to use for journal", p);
return -EEXIST;
}
if (path_is_mount_point(q, NULL, 0) > 0) {
if (try)
return 0;
log_error("%s: already a mount point, refusing to use for journal", q);
return -EEXIST;
}
r = readlink_and_make_absolute(p, &d);
if (r >= 0) {
if (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 β€” 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_verbose(LOG_DEBUG, p, q, NULL, MS_BIND, NULL);
if (r < 0)
return log_error_errno(errno, "Failed to bind mount journal from host into guest: %m");
return 0;
}
static int drop_capabilities(void) {
return capability_bounding_set_drop(arg_caps_retain, false);
}
static int reset_audit_loginuid(void) {
_cleanup_free_ char *p = NULL;
int r;
if ((arg_clone_ns_flags & CLONE_NEWPID) == 0)
return 0;
r = read_one_line_file("/proc/self/loginuid", &p);
if (r == -ENOENT)
return 0;
if (r < 0)
return log_error_errno(r, "Failed to read /proc/self/loginuid: %m");
/* Already reset? */
if (streq(p, "4294967295"))
return 0;
r = write_string_file("/proc/self/loginuid", "4294967295", 0);
if (r < 0) {
log_error_errno(r,
"Failed to reset audit login UID. This probably means that your kernel is too\n"
"old and you have audit enabled. Note that the auditing subsystem is known to\n"
"be incompatible with containers on old kernels. Please make sure to upgrade\n"
"your kernel or to off auditing with 'audit=0' on the kernel command line before\n"
"using systemd-nspawn. Sleeping for 5s... (%m)");
sleep(5);
}
return 0;
}
static int setup_propagate(const char *root) {
const char *p, *q;
int r;
(void) mkdir_p("/run/systemd/nspawn/", 0755);
(void) mkdir_p("/run/systemd/nspawn/propagate", 0600);
p = strjoina("/run/systemd/nspawn/propagate/", arg_machine);
(void) mkdir_p(p, 0600);
r = userns_mkdir(root, "/run/systemd", 0755, 0, 0);
if (r < 0)
return log_error_errno(r, "Failed to create /run/systemd: %m");
r = userns_mkdir(root, "/run/systemd/nspawn", 0755, 0, 0);
if (r < 0)
return log_error_errno(r, "Failed to create /run/systemd/nspawn: %m");
r = userns_mkdir(root, "/run/systemd/nspawn/incoming", 0600, 0, 0);
if (r < 0)
return log_error_errno(r, "Failed to create /run/systemd/nspawn/incoming: %m");
q = prefix_roota(root, "/run/systemd/nspawn/incoming");
r = mount_verbose(LOG_ERR, p, q, NULL, MS_BIND, NULL);
if (r < 0)
return r;
r = mount_verbose(LOG_ERR, NULL, q, NULL, MS_BIND|MS_REMOUNT|MS_RDONLY, NULL);
if (r < 0)
return r;
/* machined will MS_MOVE into that directory, and that's only
* supported for non-shared mounts. */
return mount_verbose(LOG_ERR, NULL, q, NULL, MS_SLAVE, NULL);
}
static int setup_machine_id(const char *directory) {
const char *etc_machine_id;
sd_id128_t id;
int r;
/* If the UUID in the container is already set, then that's what counts, and we use. If it isn't set, and the
* caller passed --uuid=, then we'll pass it in the $container_uuid env var to PID 1 of the container. The
* assumption is that PID 1 will then write it to /etc/machine-id to make it persistent. If --uuid= is not
* passed we generate a random UUID, and pass it via $container_uuid. In effect this means that /etc/machine-id
* in the container and our idea of the container UUID will always be in sync (at least if PID 1 in the
* container behaves nicely). */
etc_machine_id = prefix_roota(directory, "/etc/machine-id");
r = id128_read(etc_machine_id, ID128_PLAIN, &id);
if (r < 0) {
if (!IN_SET(r, -ENOENT, -ENOMEDIUM)) /* If the file is missing or empty, we don't mind */
return log_error_errno(r, "Failed to read machine ID from container image: %m");
if (sd_id128_is_null(arg_uuid)) {
r = sd_id128_randomize(&arg_uuid);
if (r < 0)
return log_error_errno(r, "Failed to acquire randomized machine UUID: %m");
}
} else {
if (sd_id128_is_null(id)) {
log_error("Machine ID in container image is zero, refusing.");
return -EINVAL;
}
arg_uuid = id;
}
return 0;
}
static int recursive_chown(const char *directory, uid_t shift, uid_t range) {
int r;
assert(directory);
if (arg_userns_mode == USER_NAMESPACE_NO || !arg_userns_chown)
return 0;
r = path_patch_uid(directory, arg_uid_shift, arg_uid_range);
if (r == -EOPNOTSUPP)
return log_error_errno(r, "Automatic UID/GID adjusting is only supported for UID/GID ranges starting at multiples of 2^16 with a range of 2^16.");
if (r == -EBADE)
return log_error_errno(r, "Upper 16 bits of root directory UID and GID do not match.");
if (r < 0)
return log_error_errno(r, "Failed to adjust UID/GID shift of OS tree: %m");
if (r == 0)
log_debug("Root directory of image is already owned by the right UID/GID range, skipping recursive chown operation.");
else
log_debug("Patched directory tree to match UID/GID range.");
return r;
}
/*
* 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:
log_error("Container %s terminated by signal %s.", arg_machine, signal_to_string(status.si_status));
return -EIO;
default:
log_error("Container %s failed due to unknown reason.", arg_machine);
return -EIO;
}
}
static int on_orderly_shutdown(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) {
pid_t pid;
pid = PTR_TO_PID(userdata);
if (pid > 0) {
if (kill(pid, arg_kill_signal) >= 0) {
log_info("Trying to halt container. Send SIGTERM again to trigger immediate termination.");
sd_event_source_set_userdata(s, NULL);
return 0;
}
}
sd_event_exit(sd_event_source_get_event(s), 0);
return 0;
}
static int 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 = strjoin("/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) {
log_error("Failed to determine path, please use -D or -i.");
return -EINVAL;
}
}
if (!arg_machine) {
if (arg_directory && path_equal(arg_directory, "/"))
arg_machine = gethostname_malloc();
else {
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)) {
log_error("Failed to determine machine name automatically, please use -M.");
return -EINVAL;
}
if (arg_ephemeral) {
char *b;
/* Add a random suffix when this is an
* ephemeral machine, so that we can run many
* instances at once without manually having
* to specify -M each time. */
if (asprintf(&b, "%s-%016" PRIx64, arg_machine, random_u64()) < 0)
return log_oom();
free(arg_machine);
arg_machine = b;
}
}
return 0;
}
static int 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);
if (r < 0)
return log_error_errno(r, "Failed to resolve path %s: %m", *p);
free_and_replace(*p, chased);
return r; /* r might be an fd here in case we ever use CHASE_OPEN in flags */
}
static int determine_uid_shift(const char *directory) {
int r;
if (arg_userns_mode == USER_NAMESPACE_NO) {
arg_uid_shift = 0;
return 0;
}
if (arg_uid_shift == UID_INVALID) {
struct stat st;
r = stat(directory, &st);
if (r < 0)
return log_error_errno(errno, "Failed to determine UID base of %s: %m", directory);
arg_uid_shift = st.st_uid & UINT32_C(0xffff0000);
if (arg_uid_shift != (st.st_gid & UINT32_C(0xffff0000))) {
log_error("UID and GID base of %s don't match.", directory);
return -EINVAL;
}
arg_uid_range = UINT32_C(0x10000);
}
if (arg_uid_shift > (uid_t) -1 - arg_uid_range) {
log_error("UID base too high for UID range.");
return -EINVAL;
}
return 0;
}
static int inner_child(
Barrier *barrier,
const char *directory,
bool secondary,
int kmsg_socket,
int rtnl_socket,
FDSet *fds) {
_cleanup_free_ char *home = NULL;
char as_uuid[37];
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
};
const char *exec_target;
_cleanup_strv_free_ char **env_use = NULL;
int r;
assert(barrier);
assert(directory);
assert(kmsg_socket >= 0);
if (arg_userns_mode != USER_NAMESPACE_NO) {
/* Tell the parent, that it now can write the UID map. */
(void) barrier_place(barrier); /* #1 */
/* Wait until the parent wrote the UID map */
if (!barrier_place_and_sync(barrier)) { /* #2 */
log_error("Parent died too early");
return -ESRCH;
}
}
r = reset_uid_gid();
if (r < 0)
return log_error_errno(r, "Couldn't become new root: %m");
r = mount_all(NULL,
arg_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 */
log_error("Parent died too early");
return -ESRCH;
}
if (arg_use_cgns && cg_ns_supported()) {
r = unshare(CLONE_NEWCGROUP);
if (r < 0)
return log_error_errno(errno, "Failed to unshare cgroup namespace: %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);
if (r < 0)
return r;
} 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);
if (setsid() < 0)
return log_error_errno(errno, "setsid() failed: %m");
if (arg_private_network)
loopback_setup();
if (arg_expose_ports) {
r = expose_port_send_rtnl(rtnl_socket);
if (r < 0)
return r;
rtnl_socket = safe_close(rtnl_socket);
}
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_cpuset)
if (sched_setaffinity(0, CPU_ALLOC_SIZE(arg_cpuset_ncpus), arg_cpuset) < 0)
return log_error_errno(errno, "Failed to set CPU affinity: %m");
r = drop_capabilities();
if (r < 0)
return log_error_errno(r, "drop_capabilities() failed: %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");
}
#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
r = change_uid_gid(arg_user, &home);
if (r < 0)
return r;
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 ((asprintf((char**)(envp + n_env++), "HOME=%s", home ? home: "/root") < 0) ||
(asprintf((char**)(envp + n_env++), "USER=%s", arg_user ? arg_user : "root") < 0) ||
(asprintf((char**)(envp + n_env++), "LOGNAME=%s", arg_user ? arg_user : "root") < 0))
return log_oom();
assert(!sd_id128_is_null(arg_uuid));
if (asprintf((char**)(envp + n_env++), "container_uuid=%s", id128_to_uuid_string(arg_uuid, as_uuid)) < 0)
return log_oom();
if (fdset_size(fds) > 0) {
r = fdset_cloexec(fds, false);
if (r < 0)
return log_error_errno(r, "Failed to unset O_CLOEXEC for file descriptors.");
if ((asprintf((char **)(envp + n_env++), "LISTEN_FDS=%u", fdset_size(fds)) < 0) ||
(asprintf((char **)(envp + n_env++), "LISTEN_PID=1") < 0))
return log_oom();
}
if (asprintf((char **)(envp + n_env++), "NOTIFY_SOCKET=%s", NSPAWN_NOTIFY_SOCKET_PATH) < 0)
return log_oom();
env_use = strv_env_merge(2, envp, arg_setenv);
if (!env_use)
return log_oom();
/* Let the parent know that we are ready and
* wait until the parent is ready with the
* setup, too... */
if (!barrier_place_and_sync(barrier)) { /* #5 */
log_error("Parent died too early");
return -ESRCH;
}
if (arg_chdir)
if (chdir(arg_chdir) < 0)
return log_error_errno(errno, "Failed to change to specified working directory %s: %m", arg_chdir);
if (arg_start_mode == START_PID2) {
r = stub_pid1(arg_uuid);
if (r < 0)
return r;
}
/* Now, explicitly close the log, so that we then can close all remaining fds. Closing the log explicitly first
* has the benefit that the logging subsystem knows about it, and is thus ready to be reopened should we need
* it again. Note that the other fds closed here are at least the locking and barrier fds. */
log_close();
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)) {
exec_target = arg_parameters[0];
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_sd_notify_child(void) {
static const int one = 1;
int fd = -1;
union sockaddr_union sa = {
.sa.sa_family = AF_UNIX,
};
int r;
fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
if (fd < 0)
return log_error_errno(errno, "Failed to allocate notification socket: %m");
(void) mkdir_parents(NSPAWN_NOTIFY_SOCKET_PATH, 0755);
(void) unlink(NSPAWN_NOTIFY_SOCKET_PATH);
strncpy(sa.un.sun_path, NSPAWN_NOTIFY_SOCKET_PATH, sizeof(sa.un.sun_path)-1);
r = bind(fd, &sa.sa, SOCKADDR_UN_LEN(sa.un));
if (r < 0) {
safe_close(fd);
return log_error_errno(errno, "bind(%s) failed: %m", sa.un.sun_path);
}
r = userns_lchown(NSPAWN_NOTIFY_SOCKET_PATH, 0, 0);
if (r < 0) {
safe_close(fd);
return log_error_errno(r, "Failed to chown " NSPAWN_NOTIFY_SOCKET_PATH ": %m");
}
r = setsockopt(fd, SOL_SOCKET, SO_PASSCRED, &one, sizeof(one));
if (r < 0) {
safe_close(fd);
return log_error_errno(errno, "SO_PASSCRED failed: %m");
}
return fd;
}
static int outer_child(
Barrier *barrier,
const char *directory,
const char *console,
DissectedImage *dissected_image,
bool interactive,
bool secondary,
int pid_socket,
int uuid_socket,
int notify_socket,
int kmsg_socket,
int rtnl_socket,
int uid_shift_socket,
int unified_cgroup_hierarchy_socket,
FDSet *fds,
int netns_fd) {
_cleanup_close_ int fd = -1;
int r, which_failed;
pid_t pid;
ssize_t l;
assert(barrier);
assert(directory);
assert(console);
assert(pid_socket >= 0);
assert(uuid_socket >= 0);
assert(notify_socket >= 0);
assert(kmsg_socket >= 0);
if (prctl(PR_SET_PDEATHSIG, SIGKILL) < 0)
return log_error_errno(errno, "PR_SET_PDEATHSIG failed: %m");
if (interactive) {
int terminal;
terminal = open_terminal(console, O_RDWR);
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");
r = rearrange_stdio(terminal, terminal, terminal); /* invalidates 'terminal' on success and failure */
if (r < 0)
return log_error_errno(r, "Failed to move console to stdin/stdout/stderr: %m");
}
r = reset_audit_loginuid();
if (r < 0)
return r;
/* Mark everything as slave, so that we still
* receive mounts from the real root, but don't
* propagate mounts to the real root. */
r = mount_verbose(LOG_ERR, NULL, "/", NULL, MS_SLAVE|MS_REC, NULL);
if (r < 0)
return r;
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(dissected_image, directory, arg_uid_shift,
DISSECT_IMAGE_MOUNT_ROOT_ONLY|DISSECT_IMAGE_DISCARD_ON_LOOP|
(arg_read_only ? DISSECT_IMAGE_READ_ONLY : 0)|
(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)) {
log_error("Short write while sending UID shift.");
return -EIO;
}
if (arg_userns_mode == USER_NAMESPACE_PICK) {
/* When we are supposed to pick the UID shift, the parent will check now whether the UID shift
* we just read from the image is available. If yes, it will send the UID shift back to us, if
* not it will pick a different one, and send it back to us. */
l = recv(uid_shift_socket, &arg_uid_shift, sizeof(arg_uid_shift), 0);
if (l < 0)
return log_error_errno(errno, "Failed to recv UID shift: %m");
if (l != sizeof(arg_uid_shift)) {
log_error("Short read while receiving UID shift.");
return -EIO;
}
}
if (!arg_quiet)
log_info("Selected user namespace base " UID_FMT " and range " UID_FMT ".", arg_uid_shift, arg_uid_range);
}
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 : 0));
if (r < 0)
return r;
}
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)) {
log_error("Short write while sending cgroup mode.");
return -EIO;
}
unified_cgroup_hierarchy_socket = safe_close(unified_cgroup_hierarchy_socket);
}
/* Turn directory into bind mount */
r = mount_verbose(LOG_ERR, directory, directory, NULL, MS_BIND|MS_REC, NULL);
if (r < 0)
return r;
r = setup_pivot_root(
directory,
arg_pivot_root_new,
arg_pivot_root_old);
if (r < 0)
return r;
r = setup_volatile(
directory,
arg_volatile_mode,
arg_userns_mode != USER_NAMESPACE_NO,
arg_uid_shift,
arg_uid_range,
arg_selinux_context);
if (r < 0)
return r;
r = setup_volatile_state(
directory,
arg_volatile_mode,
arg_userns_mode != USER_NAMESPACE_NO,
arg_uid_shift,
arg_uid_range,
arg_selinux_context);
if (r < 0)
return r;
/* Mark everything as shared so our mounts get propagated down. This is
* required to make new bind mounts available in systemd services
* inside the containter that create a new mount namespace.
* See https://github.com/systemd/systemd/issues/3860
* Further submounts (such as /dev) done after this will inherit the
* shared propagation mode. */
r = mount_verbose(LOG_ERR, NULL, directory, NULL, MS_SHARED|MS_REC, NULL);
if (r < 0)
return r;
r = recursive_chown(directory, arg_uid_shift, arg_uid_range);
if (r < 0)
return r;
r = base_filesystem_create(directory, arg_uid_shift, (gid_t) arg_uid_shift);
if (r < 0)
return r;
if (arg_read_only) {
r = bind_remount_recursive(directory, true, NULL);
if (r < 0)
return log_error_errno(r, "Failed to make tree read-only: %m");
}
r = mount_all(directory,
arg_mount_settings,
arg_uid_shift,
arg_selinux_apifs_context);
if (r < 0)
return r;
r = copy_devnodes(directory);
if (r < 0)
return r;
dev_setup(directory, arg_uid_shift, arg_uid_shift);
r = setup_pts(directory);
if (r < 0)
return r;
r = setup_propagate(directory);
if (r < 0)
return r;
r = setup_dev_console(directory, console);
if (r < 0)
return r;
r = setup_keyring();
if (r < 0)
return r;
r = setup_seccomp(arg_caps_retain, arg_syscall_whitelist, arg_syscall_blacklist);
if (r < 0)
return r;
r = setup_timezone(directory);
if (r < 0)
return r;
r = setup_resolv_conf(directory);
if (r < 0)
return r;
r = setup_machine_id(directory);
if (r < 0)
return r;
r = setup_journal(directory);
if (r < 0)
return r;
r = mount_custom(
directory,
arg_custom_mounts,
arg_n_custom_mounts,
arg_userns_mode != USER_NAMESPACE_NO,
arg_uid_shift,
arg_uid_range,
arg_selinux_apifs_context);
if (r < 0)
return r;
if (!arg_use_cgns || !cg_ns_supported()) {
r = mount_cgroups(
directory,
arg_unified_cgroup_hierarchy,
arg_userns_mode != USER_NAMESPACE_NO,
arg_uid_shift,
arg_uid_range,
arg_selinux_apifs_context,
false);
if (r < 0)
return r;
}
r = mount_move_root(directory);
if (r < 0)
return log_error_errno(r, "Failed to move root directory: %m");
fd = setup_sd_notify_child();
if (fd < 0)
return fd;
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));
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 r;
}
r = inner_child(barrier, directory, secondary, kmsg_socket, rtnl_socket, fds);
if (r < 0)
_exit(EXIT_FAILURE);
_exit(EXIT_SUCCESS);
}
l = send(pid_socket, &pid, sizeof(pid), MSG_NOSIGNAL);
if (l < 0)
return log_error_errno(errno, "Failed to send PID: %m");
if (l != sizeof(pid)) {
log_error("Short write while sending PID.");
return -EIO;
}
l = send(uuid_socket, &arg_uuid, sizeof(arg_uuid), MSG_NOSIGNAL);
if (l < 0)
return log_error_errno(errno, "Failed to send machine ID: %m");
if (l != sizeof(arg_uuid)) {
log_error("Short write while sending machine ID.");
return -EIO;
}
l = send_one_fd(notify_socket, fd, 0);
if (l < 0)
return log_error_errno(errno, "Failed to send notify fd: %m");
pid_socket = safe_close(pid_socket);
uuid_socket = safe_close(uuid_socket);
notify_socket = safe_close(notify_socket);
kmsg_socket = safe_close(kmsg_socket);
rtnl_socket = safe_close(rtnl_socket);
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, 0);
if (r < 0)
return log_error_errno(r, "Failed to write UID map: %m");
/* We always assign the same UID and GID ranges */
xsprintf(uid_map, "/proc/" PID_FMT "/gid_map", pid);
r = write_string_file(uid_map, line, 0);
if (r < 0)
return log_error_errno(r, "Failed to write GID map: %m");
return 0;
}
static int nspawn_dispatch_notify_fd(sd_event_source *source, int fd, uint32_t revents, void *userdata) {
char buf[NOTIFY_BUFFER_MAX+1];
char *p = NULL;
struct iovec iovec = {
.iov_base = buf,
.iov_len = sizeof(buf)-1,
};
union {
struct cmsghdr cmsghdr;
uint8_t buf[CMSG_SPACE(sizeof(struct ucred)) +
CMSG_SPACE(sizeof(int) * NOTIFY_FD_MAX)];
} control = {};
struct msghdr msghdr = {
.msg_iov = &iovec,
.msg_iovlen = 1,
.msg_control = &control,
.msg_controllen = sizeof(control),
};
struct cmsghdr *cmsg;
struct ucred *ucred = NULL;
ssize_t n;
pid_t inner_child_pid;
_cleanup_strv_free_ char **tags = NULL;
assert(userdata);
inner_child_pid = PTR_TO_PID(userdata);
if (revents != EPOLLIN) {
log_warning("Got unexpected poll event for notify fd.");
return 0;
}
n = recvmsg(fd, &msghdr, MSG_DONTWAIT|MSG_CMSG_CLOEXEC);
if (n < 0) {
if (IN_SET(errno, EAGAIN, EINTR))
return 0;
return log_warning_errno(errno, "Couldn't read notification socket: %m");
}
cmsg_close_all(&msghdr);
CMSG_FOREACH(cmsg, &msghdr) {
if (cmsg->cmsg_level == SOL_SOCKET &&
cmsg->cmsg_type == SCM_CREDENTIALS &&
cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred))) {
ucred = (struct ucred*) CMSG_DATA(cmsg);
}
}
if (!ucred || ucred->pid != inner_child_pid) {
log_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"))
sd_notifyf(false, "READY=1\n");
p = strv_find_startswith(tags, "STATUS=");
if (p)
sd_notifyf(false, "STATUS=Container running: %s", p);
return 0;
}
static int setup_sd_notify_parent(sd_event *event, int fd, pid_t *inner_child_pid, 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_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 &&
settings->user)
free_and_replace(arg_user, settings->user);
if ((arg_settings_mask & SETTING_CAPABILITY) == 0) {
uint64_t plus;
plus = settings->capability;
if (settings_private_network(settings))
plus |= (1ULL << CAP_NET_ADMIN);
if (!arg_settings_trusted && plus != 0) {
if (settings->capability != 0)
log_warning("Ignoring Capability= setting, file %s is not trusted.", path);
} else
arg_caps_retain |= plus;
arg_caps_retain &= ~settings->drop_capability;
}
if ((arg_settings_mask & SETTING_KILL_SIGNAL) == 0 &&
settings->kill_signal > 0)
arg_kill_signal = settings->kill_signal;
if ((arg_settings_mask & SETTING_PERSONALITY) == 0 &&
settings->personality != PERSONALITY_INVALID)
arg_personality = settings->personality;
if ((arg_settings_mask & SETTING_MACHINE_ID) == 0 &&
!sd_id128_is_null(settings->machine_id)) {
if (!arg_settings_trusted)
log_warning("Ignoring MachineID= setting, file %s is not trusted.", 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)) {
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);
}
}
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(arg_syscall_whitelist))
log_warning("Ignoring SystemCallFilter= settings, file %s is not trusted.", path);
else {
strv_free_and_replace(arg_syscall_whitelist, settings->syscall_whitelist);
strv_free_and_replace(arg_syscall_blacklist, settings->syscall_blacklist);
}
}