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[thirdparty/systemd.git] / src / nspawn / nspawn.c
1 /* SPDX-License-Identifier: LGPL-2.1+ */
2
3 #if HAVE_BLKID
4 #endif
5 #include <errno.h>
6 #include <getopt.h>
7 #include <linux/fs.h>
8 #include <linux/loop.h>
9 #if HAVE_SELINUX
10 #include <selinux/selinux.h>
11 #endif
12 #include <stdlib.h>
13 #include <sys/file.h>
14 #include <sys/personality.h>
15 #include <sys/prctl.h>
16 #include <sys/types.h>
17 #include <sys/wait.h>
18 #include <unistd.h>
19
20 #include "sd-bus.h"
21 #include "sd-daemon.h"
22 #include "sd-id128.h"
23
24 #include "alloc-util.h"
25 #include "barrier.h"
26 #include "base-filesystem.h"
27 #include "blkid-util.h"
28 #include "btrfs-util.h"
29 #include "bus-error.h"
30 #include "bus-util.h"
31 #include "cap-list.h"
32 #include "capability-util.h"
33 #include "cgroup-util.h"
34 #include "copy.h"
35 #include "cpu-set-util.h"
36 #include "dev-setup.h"
37 #include "dissect-image.h"
38 #include "env-util.h"
39 #include "fd-util.h"
40 #include "fdset.h"
41 #include "fileio.h"
42 #include "format-util.h"
43 #include "fs-util.h"
44 #include "gpt.h"
45 #include "hexdecoct.h"
46 #include "hostname-util.h"
47 #include "id128-util.h"
48 #include "log.h"
49 #include "loop-util.h"
50 #include "loopback-setup.h"
51 #include "machine-image.h"
52 #include "macro.h"
53 #include "main-func.h"
54 #include "missing_sched.h"
55 #include "mkdir.h"
56 #include "mount-util.h"
57 #include "mountpoint-util.h"
58 #include "namespace-util.h"
59 #include "netlink-util.h"
60 #include "nspawn-cgroup.h"
61 #include "nspawn-def.h"
62 #include "nspawn-expose-ports.h"
63 #include "nspawn-mount.h"
64 #include "nspawn-network.h"
65 #include "nspawn-oci.h"
66 #include "nspawn-patch-uid.h"
67 #include "nspawn-register.h"
68 #include "nspawn-seccomp.h"
69 #include "nspawn-settings.h"
70 #include "nspawn-setuid.h"
71 #include "nspawn-stub-pid1.h"
72 #include "nulstr-util.h"
73 #include "os-util.h"
74 #include "pager.h"
75 #include "parse-util.h"
76 #include "path-util.h"
77 #include "pretty-print.h"
78 #include "process-util.h"
79 #include "ptyfwd.h"
80 #include "random-util.h"
81 #include "raw-clone.h"
82 #include "resolve-util.h"
83 #include "rlimit-util.h"
84 #include "rm-rf.h"
85 #if HAVE_SECCOMP
86 #include "seccomp-util.h"
87 #endif
88 #include "selinux-util.h"
89 #include "signal-util.h"
90 #include "socket-util.h"
91 #include "stat-util.h"
92 #include "stdio-util.h"
93 #include "string-table.h"
94 #include "string-util.h"
95 #include "strv.h"
96 #include "sysctl-util.h"
97 #include "terminal-util.h"
98 #include "tmpfile-util.h"
99 #include "umask-util.h"
100 #include "unit-name.h"
101 #include "user-util.h"
102 #include "util.h"
103
104 /* nspawn is listening on the socket at the path in the constant nspawn_notify_socket_path
105 * nspawn_notify_socket_path is relative to the container
106 * the init process in the container pid can send messages to nspawn following the sd_notify(3) protocol */
107 #define NSPAWN_NOTIFY_SOCKET_PATH "/run/systemd/nspawn/notify"
108
109 #define EXIT_FORCE_RESTART 133
110
111 typedef enum ContainerStatus {
112 CONTAINER_TERMINATED,
113 CONTAINER_REBOOTED,
114 } ContainerStatus;
115
116 static char *arg_directory = NULL;
117 static char *arg_template = NULL;
118 static char *arg_chdir = NULL;
119 static char *arg_pivot_root_new = NULL;
120 static char *arg_pivot_root_old = NULL;
121 static char *arg_user = NULL;
122 static uid_t arg_uid = UID_INVALID;
123 static gid_t arg_gid = GID_INVALID;
124 static gid_t* arg_supplementary_gids = NULL;
125 static size_t arg_n_supplementary_gids = 0;
126 static sd_id128_t arg_uuid = {};
127 static char *arg_machine = NULL; /* The name used by the host to refer to this */
128 static char *arg_hostname = NULL; /* The name the payload sees by default */
129 static const char *arg_selinux_context = NULL;
130 static const char *arg_selinux_apifs_context = NULL;
131 static char *arg_slice = NULL;
132 static bool arg_private_network = false;
133 static bool arg_read_only = false;
134 static StartMode arg_start_mode = START_PID1;
135 static bool arg_ephemeral = false;
136 static LinkJournal arg_link_journal = LINK_AUTO;
137 static bool arg_link_journal_try = false;
138 static uint64_t arg_caps_retain =
139 (1ULL << CAP_AUDIT_CONTROL) |
140 (1ULL << CAP_AUDIT_WRITE) |
141 (1ULL << CAP_CHOWN) |
142 (1ULL << CAP_DAC_OVERRIDE) |
143 (1ULL << CAP_DAC_READ_SEARCH) |
144 (1ULL << CAP_FOWNER) |
145 (1ULL << CAP_FSETID) |
146 (1ULL << CAP_IPC_OWNER) |
147 (1ULL << CAP_KILL) |
148 (1ULL << CAP_LEASE) |
149 (1ULL << CAP_LINUX_IMMUTABLE) |
150 (1ULL << CAP_MKNOD) |
151 (1ULL << CAP_NET_BIND_SERVICE) |
152 (1ULL << CAP_NET_BROADCAST) |
153 (1ULL << CAP_NET_RAW) |
154 (1ULL << CAP_SETFCAP) |
155 (1ULL << CAP_SETGID) |
156 (1ULL << CAP_SETPCAP) |
157 (1ULL << CAP_SETUID) |
158 (1ULL << CAP_SYS_ADMIN) |
159 (1ULL << CAP_SYS_BOOT) |
160 (1ULL << CAP_SYS_CHROOT) |
161 (1ULL << CAP_SYS_NICE) |
162 (1ULL << CAP_SYS_PTRACE) |
163 (1ULL << CAP_SYS_RESOURCE) |
164 (1ULL << CAP_SYS_TTY_CONFIG);
165 static CapabilityQuintet arg_full_capabilities = CAPABILITY_QUINTET_NULL;
166 static CustomMount *arg_custom_mounts = NULL;
167 static size_t arg_n_custom_mounts = 0;
168 static char **arg_setenv = NULL;
169 static bool arg_quiet = false;
170 static bool arg_register = true;
171 static bool arg_keep_unit = false;
172 static char **arg_network_interfaces = NULL;
173 static char **arg_network_macvlan = NULL;
174 static char **arg_network_ipvlan = NULL;
175 static bool arg_network_veth = false;
176 static char **arg_network_veth_extra = NULL;
177 static char *arg_network_bridge = NULL;
178 static char *arg_network_zone = NULL;
179 static char *arg_network_namespace_path = NULL;
180 static PagerFlags arg_pager_flags = 0;
181 static unsigned long arg_personality = PERSONALITY_INVALID;
182 static char *arg_image = NULL;
183 static char *arg_oci_bundle = NULL;
184 static VolatileMode arg_volatile_mode = VOLATILE_NO;
185 static ExposePort *arg_expose_ports = NULL;
186 static char **arg_property = NULL;
187 static sd_bus_message *arg_property_message = NULL;
188 static UserNamespaceMode arg_userns_mode = USER_NAMESPACE_NO;
189 static uid_t arg_uid_shift = UID_INVALID, arg_uid_range = 0x10000U;
190 static bool arg_userns_chown = false;
191 static int arg_kill_signal = 0;
192 static CGroupUnified arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_UNKNOWN;
193 static SettingsMask arg_settings_mask = 0;
194 static int arg_settings_trusted = -1;
195 static char **arg_parameters = NULL;
196 static const char *arg_container_service_name = "systemd-nspawn";
197 static bool arg_notify_ready = false;
198 static bool arg_use_cgns = true;
199 static unsigned long arg_clone_ns_flags = CLONE_NEWIPC|CLONE_NEWPID|CLONE_NEWUTS;
200 static MountSettingsMask arg_mount_settings = MOUNT_APPLY_APIVFS_RO|MOUNT_APPLY_TMPFS_TMP;
201 static void *arg_root_hash = NULL;
202 static size_t arg_root_hash_size = 0;
203 static char **arg_syscall_whitelist = NULL;
204 static char **arg_syscall_blacklist = NULL;
205 #if HAVE_SECCOMP
206 static scmp_filter_ctx arg_seccomp = NULL;
207 #endif
208 static struct rlimit *arg_rlimit[_RLIMIT_MAX] = {};
209 static bool arg_no_new_privileges = false;
210 static int arg_oom_score_adjust = 0;
211 static bool arg_oom_score_adjust_set = false;
212 static CPUSet arg_cpu_set = {};
213 static ResolvConfMode arg_resolv_conf = RESOLV_CONF_AUTO;
214 static TimezoneMode arg_timezone = TIMEZONE_AUTO;
215 static unsigned arg_console_width = (unsigned) -1, arg_console_height = (unsigned) -1;
216 static DeviceNode* arg_extra_nodes = NULL;
217 static size_t arg_n_extra_nodes = 0;
218 static char **arg_sysctl = NULL;
219 static ConsoleMode arg_console_mode = _CONSOLE_MODE_INVALID;
220
221 STATIC_DESTRUCTOR_REGISTER(arg_directory, freep);
222 STATIC_DESTRUCTOR_REGISTER(arg_template, freep);
223 STATIC_DESTRUCTOR_REGISTER(arg_chdir, freep);
224 STATIC_DESTRUCTOR_REGISTER(arg_pivot_root_new, freep);
225 STATIC_DESTRUCTOR_REGISTER(arg_pivot_root_old, freep);
226 STATIC_DESTRUCTOR_REGISTER(arg_user, freep);
227 STATIC_DESTRUCTOR_REGISTER(arg_supplementary_gids, freep);
228 STATIC_DESTRUCTOR_REGISTER(arg_machine, freep);
229 STATIC_DESTRUCTOR_REGISTER(arg_hostname, freep);
230 STATIC_DESTRUCTOR_REGISTER(arg_slice, freep);
231 STATIC_DESTRUCTOR_REGISTER(arg_setenv, strv_freep);
232 STATIC_DESTRUCTOR_REGISTER(arg_network_interfaces, strv_freep);
233 STATIC_DESTRUCTOR_REGISTER(arg_network_macvlan, strv_freep);
234 STATIC_DESTRUCTOR_REGISTER(arg_network_ipvlan, strv_freep);
235 STATIC_DESTRUCTOR_REGISTER(arg_network_veth_extra, strv_freep);
236 STATIC_DESTRUCTOR_REGISTER(arg_network_bridge, freep);
237 STATIC_DESTRUCTOR_REGISTER(arg_network_zone, freep);
238 STATIC_DESTRUCTOR_REGISTER(arg_network_namespace_path, freep);
239 STATIC_DESTRUCTOR_REGISTER(arg_image, freep);
240 STATIC_DESTRUCTOR_REGISTER(arg_oci_bundle, freep);
241 STATIC_DESTRUCTOR_REGISTER(arg_property, strv_freep);
242 STATIC_DESTRUCTOR_REGISTER(arg_property_message, sd_bus_message_unrefp);
243 STATIC_DESTRUCTOR_REGISTER(arg_parameters, strv_freep);
244 STATIC_DESTRUCTOR_REGISTER(arg_root_hash, freep);
245 STATIC_DESTRUCTOR_REGISTER(arg_syscall_whitelist, strv_freep);
246 STATIC_DESTRUCTOR_REGISTER(arg_syscall_blacklist, strv_freep);
247 #if HAVE_SECCOMP
248 STATIC_DESTRUCTOR_REGISTER(arg_seccomp, seccomp_releasep);
249 #endif
250 STATIC_DESTRUCTOR_REGISTER(arg_cpu_set, cpu_set_reset);
251 STATIC_DESTRUCTOR_REGISTER(arg_sysctl, strv_freep);
252
253 static int handle_arg_console(const char *arg) {
254 if (streq(arg, "help")) {
255 puts("interactive\n"
256 "read-only\n"
257 "passive\n"
258 "pipe");
259 return 0;
260 }
261
262 if (streq(arg, "interactive"))
263 arg_console_mode = CONSOLE_INTERACTIVE;
264 else if (streq(arg, "read-only"))
265 arg_console_mode = CONSOLE_READ_ONLY;
266 else if (streq(arg, "passive"))
267 arg_console_mode = CONSOLE_PASSIVE;
268 else if (streq(arg, "pipe"))
269 arg_console_mode = CONSOLE_PIPE;
270 else
271 return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Unknown console mode: %s", optarg);
272
273 arg_settings_mask |= SETTING_CONSOLE_MODE;
274 return 1;
275 }
276
277 static int help(void) {
278 _cleanup_free_ char *link = NULL;
279 int r;
280
281 (void) pager_open(arg_pager_flags);
282
283 r = terminal_urlify_man("systemd-nspawn", "1", &link);
284 if (r < 0)
285 return log_oom();
286
287 printf("%1$s [OPTIONS...] [PATH] [ARGUMENTS...]\n\n"
288 "%5$sSpawn a command or OS in a light-weight container.%6$s\n\n"
289 " -h --help Show this help\n"
290 " --version Print version string\n"
291 " -q --quiet Do not show status information\n"
292 " --no-pager Do not pipe output into a pager\n"
293 " --settings=BOOLEAN Load additional settings from .nspawn file\n\n"
294 "%3$sImage:%4$s\n"
295 " -D --directory=PATH Root directory for the container\n"
296 " --template=PATH Initialize root directory from template directory,\n"
297 " if missing\n"
298 " -x --ephemeral Run container with snapshot of root directory, and\n"
299 " remove it after exit\n"
300 " -i --image=PATH Root file system disk image (or device node) for\n"
301 " the container\n"
302 " --oci-bundle=PATH OCI bundle directory\n"
303 " --read-only Mount the root directory read-only\n"
304 " --volatile[=MODE] Run the system in volatile mode\n"
305 " --root-hash=HASH Specify verity root hash for root disk image\n"
306 " --pivot-root=PATH[:PATH]\n"
307 " Pivot root to given directory in the container\n\n"
308 "%3$sExecution:%4$s\n"
309 " -a --as-pid2 Maintain a stub init as PID1, invoke binary as PID2\n"
310 " -b --boot Boot up full system (i.e. invoke init)\n"
311 " --chdir=PATH Set working directory in the container\n"
312 " -E --setenv=NAME=VALUE Pass an environment variable to PID 1\n"
313 " -u --user=USER Run the command under specified user or UID\n"
314 " --kill-signal=SIGNAL Select signal to use for shutting down PID 1\n"
315 " --notify-ready=BOOLEAN Receive notifications from the child init process\n\n"
316 "%3$sSystem Identity:%4$s\n"
317 " -M --machine=NAME Set the machine name for the container\n"
318 " --hostname=NAME Override the hostname for the container\n"
319 " --uuid=UUID Set a specific machine UUID for the container\n\n"
320 "%3$sProperties:%4$s\n"
321 " -S --slice=SLICE Place the container in the specified slice\n"
322 " --property=NAME=VALUE Set scope unit property\n"
323 " --register=BOOLEAN Register container as machine\n"
324 " --keep-unit Do not register a scope for the machine, reuse\n"
325 " the service unit nspawn is running in\n\n"
326 "%3$sUser Namespacing:%4$s\n"
327 " -U --private-users=pick Run within user namespace, autoselect UID/GID range\n"
328 " --private-users[=UIDBASE[:NUIDS]]\n"
329 " Similar, but with user configured UID/GID range\n"
330 " --private-users-chown Adjust OS tree ownership to private UID/GID range\n\n"
331 "%3$sNetworking:%4$s\n"
332 " --private-network Disable network in container\n"
333 " --network-interface=INTERFACE\n"
334 " Assign an existing network interface to the\n"
335 " container\n"
336 " --network-macvlan=INTERFACE\n"
337 " Create a macvlan network interface based on an\n"
338 " existing network interface to the container\n"
339 " --network-ipvlan=INTERFACE\n"
340 " Create a ipvlan network interface based on an\n"
341 " existing network interface to the container\n"
342 " -n --network-veth Add a virtual Ethernet connection between host\n"
343 " and container\n"
344 " --network-veth-extra=HOSTIF[:CONTAINERIF]\n"
345 " Add an additional virtual Ethernet link between\n"
346 " host and container\n"
347 " --network-bridge=INTERFACE\n"
348 " Add a virtual Ethernet connection to the container\n"
349 " and attach it to an existing bridge on the host\n"
350 " --network-zone=NAME Similar, but attach the new interface to an\n"
351 " an automatically managed bridge interface\n"
352 " --network-namespace-path=PATH\n"
353 " Set network namespace to the one represented by\n"
354 " the specified kernel namespace file node\n"
355 " -p --port=[PROTOCOL:]HOSTPORT[:CONTAINERPORT]\n"
356 " Expose a container IP port on the host\n\n"
357 "%3$sSecurity:%4$s\n"
358 " --capability=CAP In addition to the default, retain specified\n"
359 " capability\n"
360 " --drop-capability=CAP Drop the specified capability from the default set\n"
361 " --no-new-privileges Set PR_SET_NO_NEW_PRIVS flag for container payload\n"
362 " --system-call-filter=LIST|~LIST\n"
363 " Permit/prohibit specific system calls\n"
364 " -Z --selinux-context=SECLABEL\n"
365 " Set the SELinux security context to be used by\n"
366 " processes in the container\n"
367 " -L --selinux-apifs-context=SECLABEL\n"
368 " Set the SELinux security context to be used by\n"
369 " API/tmpfs file systems in the container\n\n"
370 "%3$sResources:%4$s\n"
371 " --rlimit=NAME=LIMIT Set a resource limit for the payload\n"
372 " --oom-score-adjust=VALUE\n"
373 " Adjust the OOM score value for the payload\n"
374 " --cpu-affinity=CPUS Adjust the CPU affinity of the container\n"
375 " --personality=ARCH Pick personality for this container\n\n"
376 "%3$sIntegration:%4$s\n"
377 " --resolv-conf=MODE Select mode of /etc/resolv.conf initialization\n"
378 " --timezone=MODE Select mode of /etc/localtime initialization\n"
379 " --link-journal=MODE Link up guest journal, one of no, auto, guest, \n"
380 " host, try-guest, try-host\n"
381 " -j Equivalent to --link-journal=try-guest\n\n"
382 "%3$sMounts:%4$s\n"
383 " --bind=PATH[:PATH[:OPTIONS]]\n"
384 " Bind mount a file or directory from the host into\n"
385 " the container\n"
386 " --bind-ro=PATH[:PATH[:OPTIONS]\n"
387 " Similar, but creates a read-only bind mount\n"
388 " --inaccessible=PATH Over-mount file node with inaccessible node to mask\n"
389 " it\n"
390 " --tmpfs=PATH:[OPTIONS] Mount an empty tmpfs to the specified directory\n"
391 " --overlay=PATH[:PATH...]:PATH\n"
392 " Create an overlay mount from the host to \n"
393 " the container\n"
394 " --overlay-ro=PATH[:PATH...]:PATH\n"
395 " Similar, but creates a read-only overlay mount\n\n"
396 "%3$sInput/Output:%4$s\n"
397 " --console=MODE Select how stdin/stdout/stderr and /dev/console are\n"
398 " set up for the container.\n"
399 " -P --pipe Equivalent to --console=pipe\n"
400 "\nSee the %2$s for details.\n"
401 , program_invocation_short_name
402 , link
403 , ansi_underline(), ansi_normal()
404 , ansi_highlight(), ansi_normal()
405 );
406
407 return 0;
408 }
409
410 static int custom_mount_check_all(void) {
411 size_t i;
412
413 for (i = 0; i < arg_n_custom_mounts; i++) {
414 CustomMount *m = &arg_custom_mounts[i];
415
416 if (path_equal(m->destination, "/") && arg_userns_mode != USER_NAMESPACE_NO) {
417 if (arg_userns_chown)
418 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
419 "--private-users-chown may not be combined with custom root mounts.");
420 else if (arg_uid_shift == UID_INVALID)
421 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
422 "--private-users with automatic UID shift may not be combined with custom root mounts.");
423 }
424 }
425
426 return 0;
427 }
428
429 static int detect_unified_cgroup_hierarchy_from_environment(void) {
430 const char *e, *var = "SYSTEMD_NSPAWN_UNIFIED_HIERARCHY";
431 int r;
432
433 /* Allow the user to control whether the unified hierarchy is used */
434
435 e = getenv(var);
436 if (!e) {
437 /* $UNIFIED_CGROUP_HIERARCHY has been renamed to $SYSTEMD_NSPAWN_UNIFIED_HIERARCHY. */
438 var = "UNIFIED_CGROUP_HIERARCHY";
439 e = getenv(var);
440 }
441
442 if (!isempty(e)) {
443 r = parse_boolean(e);
444 if (r < 0)
445 return log_error_errno(r, "Failed to parse $%s: %m", var);
446 if (r > 0)
447 arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_ALL;
448 else
449 arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_NONE;
450 }
451
452 return 0;
453 }
454
455 static int detect_unified_cgroup_hierarchy_from_image(const char *directory) {
456 int r;
457
458 /* Let's inherit the mode to use from the host system, but let's take into consideration what systemd
459 * in the image actually supports. */
460 r = cg_all_unified();
461 if (r < 0)
462 return log_error_errno(r, "Failed to determine whether we are in all unified mode.");
463 if (r > 0) {
464 /* Unified cgroup hierarchy support was added in 230. Unfortunately the detection
465 * routine only detects 231, so we'll have a false negative here for 230. */
466 r = systemd_installation_has_version(directory, 230);
467 if (r < 0)
468 return log_error_errno(r, "Failed to determine systemd version in container: %m");
469 if (r > 0)
470 arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_ALL;
471 else
472 arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_NONE;
473 } else if (cg_unified_controller(SYSTEMD_CGROUP_CONTROLLER) > 0) {
474 /* Mixed cgroup hierarchy support was added in 233 */
475 r = systemd_installation_has_version(directory, 233);
476 if (r < 0)
477 return log_error_errno(r, "Failed to determine systemd version in container: %m");
478 if (r > 0)
479 arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_SYSTEMD;
480 else
481 arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_NONE;
482 } else
483 arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_NONE;
484
485 log_debug("Using %s hierarchy for container.",
486 arg_unified_cgroup_hierarchy == CGROUP_UNIFIED_NONE ? "legacy" :
487 arg_unified_cgroup_hierarchy == CGROUP_UNIFIED_SYSTEMD ? "hybrid" : "unified");
488
489 return 0;
490 }
491
492 static int parse_capability_spec(const char *spec, uint64_t *ret_mask) {
493 uint64_t mask = 0;
494 int r;
495
496 for (;;) {
497 _cleanup_free_ char *t = NULL;
498
499 r = extract_first_word(&spec, &t, ",", 0);
500 if (r < 0)
501 return log_error_errno(r, "Failed to parse capability %s.", t);
502 if (r == 0)
503 break;
504
505 if (streq(t, "help")) {
506 for (int i = 0; i < capability_list_length(); i++) {
507 const char *name;
508
509 name = capability_to_name(i);
510 if (name)
511 puts(name);
512 }
513
514 return 0; /* quit */
515 }
516
517 if (streq(t, "all"))
518 mask = (uint64_t) -1;
519 else {
520 r = capability_from_name(t);
521 if (r < 0)
522 return log_error_errno(r, "Failed to parse capability %s.", t);
523
524 mask |= 1ULL << r;
525 }
526 }
527
528 *ret_mask = mask;
529 return 1; /* continue */
530 }
531
532 static int parse_share_ns_env(const char *name, unsigned long ns_flag) {
533 int r;
534
535 r = getenv_bool(name);
536 if (r == -ENXIO)
537 return 0;
538 if (r < 0)
539 return log_error_errno(r, "Failed to parse $%s: %m", name);
540
541 arg_clone_ns_flags = (arg_clone_ns_flags & ~ns_flag) | (r > 0 ? 0 : ns_flag);
542 arg_settings_mask |= SETTING_CLONE_NS_FLAGS;
543 return 0;
544 }
545
546 static int parse_mount_settings_env(void) {
547 const char *e;
548 int r;
549
550 r = getenv_bool("SYSTEMD_NSPAWN_TMPFS_TMP");
551 if (r < 0 && r != -ENXIO)
552 return log_error_errno(r, "Failed to parse $SYSTEMD_NSPAWN_TMPFS_TMP: %m");
553 if (r >= 0)
554 SET_FLAG(arg_mount_settings, MOUNT_APPLY_TMPFS_TMP, r > 0);
555
556 e = getenv("SYSTEMD_NSPAWN_API_VFS_WRITABLE");
557 if (streq_ptr(e, "network"))
558 arg_mount_settings |= MOUNT_APPLY_APIVFS_RO|MOUNT_APPLY_APIVFS_NETNS;
559
560 else if (e) {
561 r = parse_boolean(e);
562 if (r < 0)
563 return log_error_errno(r, "Failed to parse $SYSTEMD_NSPAWN_API_VFS_WRITABLE: %m");
564
565 SET_FLAG(arg_mount_settings, MOUNT_APPLY_APIVFS_RO, r == 0);
566 SET_FLAG(arg_mount_settings, MOUNT_APPLY_APIVFS_NETNS, false);
567 }
568
569 return 0;
570 }
571
572 static int parse_environment(void) {
573 const char *e;
574 int r;
575
576 r = parse_share_ns_env("SYSTEMD_NSPAWN_SHARE_NS_IPC", CLONE_NEWIPC);
577 if (r < 0)
578 return r;
579 r = parse_share_ns_env("SYSTEMD_NSPAWN_SHARE_NS_PID", CLONE_NEWPID);
580 if (r < 0)
581 return r;
582 r = parse_share_ns_env("SYSTEMD_NSPAWN_SHARE_NS_UTS", CLONE_NEWUTS);
583 if (r < 0)
584 return r;
585 r = parse_share_ns_env("SYSTEMD_NSPAWN_SHARE_SYSTEM", CLONE_NEWIPC|CLONE_NEWPID|CLONE_NEWUTS);
586 if (r < 0)
587 return r;
588
589 r = parse_mount_settings_env();
590 if (r < 0)
591 return r;
592
593 /* SYSTEMD_NSPAWN_USE_CGNS=0 can be used to disable CLONE_NEWCGROUP use,
594 * even if it is supported. If not supported, it has no effect. */
595 if (!cg_ns_supported())
596 arg_use_cgns = false;
597 else {
598 r = getenv_bool("SYSTEMD_NSPAWN_USE_CGNS");
599 if (r < 0) {
600 if (r != -ENXIO)
601 return log_error_errno(r, "Failed to parse $SYSTEMD_NSPAWN_USE_CGNS: %m");
602
603 arg_use_cgns = true;
604 } else {
605 arg_use_cgns = r > 0;
606 arg_settings_mask |= SETTING_USE_CGNS;
607 }
608 }
609
610 e = getenv("SYSTEMD_NSPAWN_CONTAINER_SERVICE");
611 if (e)
612 arg_container_service_name = e;
613
614 return detect_unified_cgroup_hierarchy_from_environment();
615 }
616
617 static int parse_argv(int argc, char *argv[]) {
618 enum {
619 ARG_VERSION = 0x100,
620 ARG_PRIVATE_NETWORK,
621 ARG_UUID,
622 ARG_READ_ONLY,
623 ARG_CAPABILITY,
624 ARG_DROP_CAPABILITY,
625 ARG_LINK_JOURNAL,
626 ARG_BIND,
627 ARG_BIND_RO,
628 ARG_TMPFS,
629 ARG_OVERLAY,
630 ARG_OVERLAY_RO,
631 ARG_INACCESSIBLE,
632 ARG_SHARE_SYSTEM,
633 ARG_REGISTER,
634 ARG_KEEP_UNIT,
635 ARG_NETWORK_INTERFACE,
636 ARG_NETWORK_MACVLAN,
637 ARG_NETWORK_IPVLAN,
638 ARG_NETWORK_BRIDGE,
639 ARG_NETWORK_ZONE,
640 ARG_NETWORK_VETH_EXTRA,
641 ARG_NETWORK_NAMESPACE_PATH,
642 ARG_PERSONALITY,
643 ARG_VOLATILE,
644 ARG_TEMPLATE,
645 ARG_PROPERTY,
646 ARG_PRIVATE_USERS,
647 ARG_KILL_SIGNAL,
648 ARG_SETTINGS,
649 ARG_CHDIR,
650 ARG_PIVOT_ROOT,
651 ARG_PRIVATE_USERS_CHOWN,
652 ARG_NOTIFY_READY,
653 ARG_ROOT_HASH,
654 ARG_SYSTEM_CALL_FILTER,
655 ARG_RLIMIT,
656 ARG_HOSTNAME,
657 ARG_NO_NEW_PRIVILEGES,
658 ARG_OOM_SCORE_ADJUST,
659 ARG_CPU_AFFINITY,
660 ARG_RESOLV_CONF,
661 ARG_TIMEZONE,
662 ARG_CONSOLE,
663 ARG_PIPE,
664 ARG_OCI_BUNDLE,
665 ARG_NO_PAGER,
666 };
667
668 static const struct option options[] = {
669 { "help", no_argument, NULL, 'h' },
670 { "version", no_argument, NULL, ARG_VERSION },
671 { "directory", required_argument, NULL, 'D' },
672 { "template", required_argument, NULL, ARG_TEMPLATE },
673 { "ephemeral", no_argument, NULL, 'x' },
674 { "user", required_argument, NULL, 'u' },
675 { "private-network", no_argument, NULL, ARG_PRIVATE_NETWORK },
676 { "as-pid2", no_argument, NULL, 'a' },
677 { "boot", no_argument, NULL, 'b' },
678 { "uuid", required_argument, NULL, ARG_UUID },
679 { "read-only", no_argument, NULL, ARG_READ_ONLY },
680 { "capability", required_argument, NULL, ARG_CAPABILITY },
681 { "drop-capability", required_argument, NULL, ARG_DROP_CAPABILITY },
682 { "no-new-privileges", required_argument, NULL, ARG_NO_NEW_PRIVILEGES },
683 { "link-journal", required_argument, NULL, ARG_LINK_JOURNAL },
684 { "bind", required_argument, NULL, ARG_BIND },
685 { "bind-ro", required_argument, NULL, ARG_BIND_RO },
686 { "tmpfs", required_argument, NULL, ARG_TMPFS },
687 { "overlay", required_argument, NULL, ARG_OVERLAY },
688 { "overlay-ro", required_argument, NULL, ARG_OVERLAY_RO },
689 { "inaccessible", required_argument, NULL, ARG_INACCESSIBLE },
690 { "machine", required_argument, NULL, 'M' },
691 { "hostname", required_argument, NULL, ARG_HOSTNAME },
692 { "slice", required_argument, NULL, 'S' },
693 { "setenv", required_argument, NULL, 'E' },
694 { "selinux-context", required_argument, NULL, 'Z' },
695 { "selinux-apifs-context", required_argument, NULL, 'L' },
696 { "quiet", no_argument, NULL, 'q' },
697 { "share-system", no_argument, NULL, ARG_SHARE_SYSTEM }, /* not documented */
698 { "register", required_argument, NULL, ARG_REGISTER },
699 { "keep-unit", no_argument, NULL, ARG_KEEP_UNIT },
700 { "network-interface", required_argument, NULL, ARG_NETWORK_INTERFACE },
701 { "network-macvlan", required_argument, NULL, ARG_NETWORK_MACVLAN },
702 { "network-ipvlan", required_argument, NULL, ARG_NETWORK_IPVLAN },
703 { "network-veth", no_argument, NULL, 'n' },
704 { "network-veth-extra", required_argument, NULL, ARG_NETWORK_VETH_EXTRA },
705 { "network-bridge", required_argument, NULL, ARG_NETWORK_BRIDGE },
706 { "network-zone", required_argument, NULL, ARG_NETWORK_ZONE },
707 { "network-namespace-path", required_argument, NULL, ARG_NETWORK_NAMESPACE_PATH },
708 { "personality", required_argument, NULL, ARG_PERSONALITY },
709 { "image", required_argument, NULL, 'i' },
710 { "volatile", optional_argument, NULL, ARG_VOLATILE },
711 { "port", required_argument, NULL, 'p' },
712 { "property", required_argument, NULL, ARG_PROPERTY },
713 { "private-users", optional_argument, NULL, ARG_PRIVATE_USERS },
714 { "private-users-chown", optional_argument, NULL, ARG_PRIVATE_USERS_CHOWN },
715 { "kill-signal", required_argument, NULL, ARG_KILL_SIGNAL },
716 { "settings", required_argument, NULL, ARG_SETTINGS },
717 { "chdir", required_argument, NULL, ARG_CHDIR },
718 { "pivot-root", required_argument, NULL, ARG_PIVOT_ROOT },
719 { "notify-ready", required_argument, NULL, ARG_NOTIFY_READY },
720 { "root-hash", required_argument, NULL, ARG_ROOT_HASH },
721 { "system-call-filter", required_argument, NULL, ARG_SYSTEM_CALL_FILTER },
722 { "rlimit", required_argument, NULL, ARG_RLIMIT },
723 { "oom-score-adjust", required_argument, NULL, ARG_OOM_SCORE_ADJUST },
724 { "cpu-affinity", required_argument, NULL, ARG_CPU_AFFINITY },
725 { "resolv-conf", required_argument, NULL, ARG_RESOLV_CONF },
726 { "timezone", required_argument, NULL, ARG_TIMEZONE },
727 { "console", required_argument, NULL, ARG_CONSOLE },
728 { "pipe", no_argument, NULL, ARG_PIPE },
729 { "oci-bundle", required_argument, NULL, ARG_OCI_BUNDLE },
730 { "no-pager", no_argument, NULL, ARG_NO_PAGER },
731 {}
732 };
733
734 int c, r;
735 uint64_t plus = 0, minus = 0;
736 bool mask_all_settings = false, mask_no_settings = false;
737
738 assert(argc >= 0);
739 assert(argv);
740
741 while ((c = getopt_long(argc, argv, "+hD:u:abL:M:jS:Z:qi:xp:nUE:P", options, NULL)) >= 0)
742 switch (c) {
743
744 case 'h':
745 return help();
746
747 case ARG_VERSION:
748 return version();
749
750 case 'D':
751 r = parse_path_argument_and_warn(optarg, false, &arg_directory);
752 if (r < 0)
753 return r;
754
755 arg_settings_mask |= SETTING_DIRECTORY;
756 break;
757
758 case ARG_TEMPLATE:
759 r = parse_path_argument_and_warn(optarg, false, &arg_template);
760 if (r < 0)
761 return r;
762
763 arg_settings_mask |= SETTING_DIRECTORY;
764 break;
765
766 case 'i':
767 r = parse_path_argument_and_warn(optarg, false, &arg_image);
768 if (r < 0)
769 return r;
770
771 arg_settings_mask |= SETTING_DIRECTORY;
772 break;
773
774 case ARG_OCI_BUNDLE:
775 r = parse_path_argument_and_warn(optarg, false, &arg_oci_bundle);
776 if (r < 0)
777 return r;
778
779 break;
780
781 case 'x':
782 arg_ephemeral = true;
783 arg_settings_mask |= SETTING_EPHEMERAL;
784 break;
785
786 case 'u':
787 r = free_and_strdup(&arg_user, optarg);
788 if (r < 0)
789 return log_oom();
790
791 arg_settings_mask |= SETTING_USER;
792 break;
793
794 case ARG_NETWORK_ZONE: {
795 char *j;
796
797 j = strjoin("vz-", optarg);
798 if (!j)
799 return log_oom();
800
801 if (!ifname_valid(j)) {
802 log_error("Network zone name not valid: %s", j);
803 free(j);
804 return -EINVAL;
805 }
806
807 free_and_replace(arg_network_zone, j);
808
809 arg_network_veth = true;
810 arg_private_network = true;
811 arg_settings_mask |= SETTING_NETWORK;
812 break;
813 }
814
815 case ARG_NETWORK_BRIDGE:
816
817 if (!ifname_valid(optarg))
818 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
819 "Bridge interface name not valid: %s", optarg);
820
821 r = free_and_strdup(&arg_network_bridge, optarg);
822 if (r < 0)
823 return log_oom();
824
825 _fallthrough_;
826 case 'n':
827 arg_network_veth = true;
828 arg_private_network = true;
829 arg_settings_mask |= SETTING_NETWORK;
830 break;
831
832 case ARG_NETWORK_VETH_EXTRA:
833 r = veth_extra_parse(&arg_network_veth_extra, optarg);
834 if (r < 0)
835 return log_error_errno(r, "Failed to parse --network-veth-extra= parameter: %s", optarg);
836
837 arg_private_network = true;
838 arg_settings_mask |= SETTING_NETWORK;
839 break;
840
841 case ARG_NETWORK_INTERFACE:
842 if (!ifname_valid(optarg))
843 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
844 "Network interface name not valid: %s", optarg);
845
846 r = test_network_interface_initialized(optarg);
847 if (r < 0)
848 return r;
849
850 if (strv_extend(&arg_network_interfaces, optarg) < 0)
851 return log_oom();
852
853 arg_private_network = true;
854 arg_settings_mask |= SETTING_NETWORK;
855 break;
856
857 case ARG_NETWORK_MACVLAN:
858
859 if (!ifname_valid(optarg))
860 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
861 "MACVLAN network interface name not valid: %s", optarg);
862
863 r = test_network_interface_initialized(optarg);
864 if (r < 0)
865 return r;
866
867 if (strv_extend(&arg_network_macvlan, optarg) < 0)
868 return log_oom();
869
870 arg_private_network = true;
871 arg_settings_mask |= SETTING_NETWORK;
872 break;
873
874 case ARG_NETWORK_IPVLAN:
875
876 if (!ifname_valid(optarg))
877 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
878 "IPVLAN network interface name not valid: %s", optarg);
879
880 r = test_network_interface_initialized(optarg);
881 if (r < 0)
882 return r;
883
884 if (strv_extend(&arg_network_ipvlan, optarg) < 0)
885 return log_oom();
886
887 _fallthrough_;
888 case ARG_PRIVATE_NETWORK:
889 arg_private_network = true;
890 arg_settings_mask |= SETTING_NETWORK;
891 break;
892
893 case ARG_NETWORK_NAMESPACE_PATH:
894 r = parse_path_argument_and_warn(optarg, false, &arg_network_namespace_path);
895 if (r < 0)
896 return r;
897
898 arg_settings_mask |= SETTING_NETWORK;
899 break;
900
901 case 'b':
902 if (arg_start_mode == START_PID2)
903 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
904 "--boot and --as-pid2 may not be combined.");
905
906 arg_start_mode = START_BOOT;
907 arg_settings_mask |= SETTING_START_MODE;
908 break;
909
910 case 'a':
911 if (arg_start_mode == START_BOOT)
912 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
913 "--boot and --as-pid2 may not be combined.");
914
915 arg_start_mode = START_PID2;
916 arg_settings_mask |= SETTING_START_MODE;
917 break;
918
919 case ARG_UUID:
920 r = sd_id128_from_string(optarg, &arg_uuid);
921 if (r < 0)
922 return log_error_errno(r, "Invalid UUID: %s", optarg);
923
924 if (sd_id128_is_null(arg_uuid))
925 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
926 "Machine UUID may not be all zeroes.");
927
928 arg_settings_mask |= SETTING_MACHINE_ID;
929 break;
930
931 case 'S': {
932 _cleanup_free_ char *mangled = NULL;
933
934 r = unit_name_mangle_with_suffix(optarg, NULL, UNIT_NAME_MANGLE_WARN, ".slice", &mangled);
935 if (r < 0)
936 return log_oom();
937
938 free_and_replace(arg_slice, mangled);
939 arg_settings_mask |= SETTING_SLICE;
940 break;
941 }
942
943 case 'M':
944 if (isempty(optarg))
945 arg_machine = mfree(arg_machine);
946 else {
947 if (!machine_name_is_valid(optarg))
948 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
949 "Invalid machine name: %s", optarg);
950
951 r = free_and_strdup(&arg_machine, optarg);
952 if (r < 0)
953 return log_oom();
954 }
955 break;
956
957 case ARG_HOSTNAME:
958 if (isempty(optarg))
959 arg_hostname = mfree(arg_hostname);
960 else {
961 if (!hostname_is_valid(optarg, false))
962 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
963 "Invalid hostname: %s", optarg);
964
965 r = free_and_strdup(&arg_hostname, optarg);
966 if (r < 0)
967 return log_oom();
968 }
969
970 arg_settings_mask |= SETTING_HOSTNAME;
971 break;
972
973 case 'Z':
974 arg_selinux_context = optarg;
975 break;
976
977 case 'L':
978 arg_selinux_apifs_context = optarg;
979 break;
980
981 case ARG_READ_ONLY:
982 arg_read_only = true;
983 arg_settings_mask |= SETTING_READ_ONLY;
984 break;
985
986 case ARG_CAPABILITY:
987 case ARG_DROP_CAPABILITY: {
988 uint64_t m;
989 r = parse_capability_spec(optarg, &m);
990 if (r <= 0)
991 return r;
992
993 if (c == ARG_CAPABILITY)
994 plus |= m;
995 else
996 minus |= m;
997 arg_settings_mask |= SETTING_CAPABILITY;
998 break;
999 }
1000 case ARG_NO_NEW_PRIVILEGES:
1001 r = parse_boolean(optarg);
1002 if (r < 0)
1003 return log_error_errno(r, "Failed to parse --no-new-privileges= argument: %s", optarg);
1004
1005 arg_no_new_privileges = r;
1006 arg_settings_mask |= SETTING_NO_NEW_PRIVILEGES;
1007 break;
1008
1009 case 'j':
1010 arg_link_journal = LINK_GUEST;
1011 arg_link_journal_try = true;
1012 arg_settings_mask |= SETTING_LINK_JOURNAL;
1013 break;
1014
1015 case ARG_LINK_JOURNAL:
1016 r = parse_link_journal(optarg, &arg_link_journal, &arg_link_journal_try);
1017 if (r < 0)
1018 return log_error_errno(r, "Failed to parse link journal mode %s", optarg);
1019
1020 arg_settings_mask |= SETTING_LINK_JOURNAL;
1021 break;
1022
1023 case ARG_BIND:
1024 case ARG_BIND_RO:
1025 r = bind_mount_parse(&arg_custom_mounts, &arg_n_custom_mounts, optarg, c == ARG_BIND_RO);
1026 if (r < 0)
1027 return log_error_errno(r, "Failed to parse --bind(-ro)= argument %s: %m", optarg);
1028
1029 arg_settings_mask |= SETTING_CUSTOM_MOUNTS;
1030 break;
1031
1032 case ARG_TMPFS:
1033 r = tmpfs_mount_parse(&arg_custom_mounts, &arg_n_custom_mounts, optarg);
1034 if (r < 0)
1035 return log_error_errno(r, "Failed to parse --tmpfs= argument %s: %m", optarg);
1036
1037 arg_settings_mask |= SETTING_CUSTOM_MOUNTS;
1038 break;
1039
1040 case ARG_OVERLAY:
1041 case ARG_OVERLAY_RO:
1042 r = overlay_mount_parse(&arg_custom_mounts, &arg_n_custom_mounts, optarg, c == ARG_OVERLAY_RO);
1043 if (r == -EADDRNOTAVAIL)
1044 return log_error_errno(r, "--overlay(-ro)= needs at least two colon-separated directories specified.");
1045 if (r < 0)
1046 return log_error_errno(r, "Failed to parse --overlay(-ro)= argument %s: %m", optarg);
1047
1048 arg_settings_mask |= SETTING_CUSTOM_MOUNTS;
1049 break;
1050
1051 case ARG_INACCESSIBLE:
1052 r = inaccessible_mount_parse(&arg_custom_mounts, &arg_n_custom_mounts, optarg);
1053 if (r < 0)
1054 return log_error_errno(r, "Failed to parse --inaccessible= argument %s: %m", optarg);
1055
1056 arg_settings_mask |= SETTING_CUSTOM_MOUNTS;
1057 break;
1058
1059 case 'E': {
1060 char **n;
1061
1062 if (!env_assignment_is_valid(optarg))
1063 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
1064 "Environment variable assignment '%s' is not valid.", optarg);
1065
1066 n = strv_env_set(arg_setenv, optarg);
1067 if (!n)
1068 return log_oom();
1069
1070 strv_free_and_replace(arg_setenv, n);
1071 arg_settings_mask |= SETTING_ENVIRONMENT;
1072 break;
1073 }
1074
1075 case 'q':
1076 arg_quiet = true;
1077 break;
1078
1079 case ARG_SHARE_SYSTEM:
1080 /* We don't officially support this anymore, except for compat reasons. People should use the
1081 * $SYSTEMD_NSPAWN_SHARE_* environment variables instead. */
1082 log_warning("Please do not use --share-system anymore, use $SYSTEMD_NSPAWN_SHARE_* instead.");
1083 arg_clone_ns_flags = 0;
1084 break;
1085
1086 case ARG_REGISTER:
1087 r = parse_boolean(optarg);
1088 if (r < 0) {
1089 log_error("Failed to parse --register= argument: %s", optarg);
1090 return r;
1091 }
1092
1093 arg_register = r;
1094 break;
1095
1096 case ARG_KEEP_UNIT:
1097 arg_keep_unit = true;
1098 break;
1099
1100 case ARG_PERSONALITY:
1101
1102 arg_personality = personality_from_string(optarg);
1103 if (arg_personality == PERSONALITY_INVALID)
1104 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
1105 "Unknown or unsupported personality '%s'.", optarg);
1106
1107 arg_settings_mask |= SETTING_PERSONALITY;
1108 break;
1109
1110 case ARG_VOLATILE:
1111
1112 if (!optarg)
1113 arg_volatile_mode = VOLATILE_YES;
1114 else if (streq(optarg, "help")) {
1115 DUMP_STRING_TABLE(volatile_mode, VolatileMode, _VOLATILE_MODE_MAX);
1116 return 0;
1117 } else {
1118 VolatileMode m;
1119
1120 m = volatile_mode_from_string(optarg);
1121 if (m < 0)
1122 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
1123 "Failed to parse --volatile= argument: %s", optarg);
1124 else
1125 arg_volatile_mode = m;
1126 }
1127
1128 arg_settings_mask |= SETTING_VOLATILE_MODE;
1129 break;
1130
1131 case 'p':
1132 r = expose_port_parse(&arg_expose_ports, optarg);
1133 if (r == -EEXIST)
1134 return log_error_errno(r, "Duplicate port specification: %s", optarg);
1135 if (r < 0)
1136 return log_error_errno(r, "Failed to parse host port %s: %m", optarg);
1137
1138 arg_settings_mask |= SETTING_EXPOSE_PORTS;
1139 break;
1140
1141 case ARG_PROPERTY:
1142 if (strv_extend(&arg_property, optarg) < 0)
1143 return log_oom();
1144
1145 break;
1146
1147 case ARG_PRIVATE_USERS: {
1148 int boolean = -1;
1149
1150 if (!optarg)
1151 boolean = true;
1152 else if (!in_charset(optarg, DIGITS))
1153 /* do *not* parse numbers as booleans */
1154 boolean = parse_boolean(optarg);
1155
1156 if (boolean == false) {
1157 /* no: User namespacing off */
1158 arg_userns_mode = USER_NAMESPACE_NO;
1159 arg_uid_shift = UID_INVALID;
1160 arg_uid_range = UINT32_C(0x10000);
1161 } else if (boolean == true) {
1162 /* yes: User namespacing on, UID range is read from root dir */
1163 arg_userns_mode = USER_NAMESPACE_FIXED;
1164 arg_uid_shift = UID_INVALID;
1165 arg_uid_range = UINT32_C(0x10000);
1166 } else if (streq(optarg, "pick")) {
1167 /* pick: User namespacing on, UID range is picked randomly */
1168 arg_userns_mode = USER_NAMESPACE_PICK;
1169 arg_uid_shift = UID_INVALID;
1170 arg_uid_range = UINT32_C(0x10000);
1171 } else {
1172 _cleanup_free_ char *buffer = NULL;
1173 const char *range, *shift;
1174
1175 /* anything else: User namespacing on, UID range is explicitly configured */
1176
1177 range = strchr(optarg, ':');
1178 if (range) {
1179 buffer = strndup(optarg, range - optarg);
1180 if (!buffer)
1181 return log_oom();
1182 shift = buffer;
1183
1184 range++;
1185 r = safe_atou32(range, &arg_uid_range);
1186 if (r < 0)
1187 return log_error_errno(r, "Failed to parse UID range \"%s\": %m", range);
1188 } else
1189 shift = optarg;
1190
1191 r = parse_uid(shift, &arg_uid_shift);
1192 if (r < 0)
1193 return log_error_errno(r, "Failed to parse UID \"%s\": %m", optarg);
1194
1195 arg_userns_mode = USER_NAMESPACE_FIXED;
1196 }
1197
1198 if (arg_uid_range <= 0)
1199 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
1200 "UID range cannot be 0.");
1201
1202 arg_settings_mask |= SETTING_USERNS;
1203 break;
1204 }
1205
1206 case 'U':
1207 if (userns_supported()) {
1208 arg_userns_mode = USER_NAMESPACE_PICK;
1209 arg_uid_shift = UID_INVALID;
1210 arg_uid_range = UINT32_C(0x10000);
1211
1212 arg_settings_mask |= SETTING_USERNS;
1213 }
1214
1215 break;
1216
1217 case ARG_PRIVATE_USERS_CHOWN:
1218 arg_userns_chown = true;
1219
1220 arg_settings_mask |= SETTING_USERNS;
1221 break;
1222
1223 case ARG_KILL_SIGNAL:
1224 if (streq(optarg, "help")) {
1225 DUMP_STRING_TABLE(signal, int, _NSIG);
1226 return 0;
1227 }
1228
1229 arg_kill_signal = signal_from_string(optarg);
1230 if (arg_kill_signal < 0)
1231 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
1232 "Cannot parse signal: %s", optarg);
1233
1234 arg_settings_mask |= SETTING_KILL_SIGNAL;
1235 break;
1236
1237 case ARG_SETTINGS:
1238
1239 /* no → do not read files
1240 * yes → read files, do not override cmdline, trust only subset
1241 * override → read files, override cmdline, trust only subset
1242 * trusted → read files, do not override cmdline, trust all
1243 */
1244
1245 r = parse_boolean(optarg);
1246 if (r < 0) {
1247 if (streq(optarg, "trusted")) {
1248 mask_all_settings = false;
1249 mask_no_settings = false;
1250 arg_settings_trusted = true;
1251
1252 } else if (streq(optarg, "override")) {
1253 mask_all_settings = false;
1254 mask_no_settings = true;
1255 arg_settings_trusted = -1;
1256 } else
1257 return log_error_errno(r, "Failed to parse --settings= argument: %s", optarg);
1258 } else if (r > 0) {
1259 /* yes */
1260 mask_all_settings = false;
1261 mask_no_settings = false;
1262 arg_settings_trusted = -1;
1263 } else {
1264 /* no */
1265 mask_all_settings = true;
1266 mask_no_settings = false;
1267 arg_settings_trusted = false;
1268 }
1269
1270 break;
1271
1272 case ARG_CHDIR:
1273 if (!path_is_absolute(optarg))
1274 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
1275 "Working directory %s is not an absolute path.", optarg);
1276
1277 r = free_and_strdup(&arg_chdir, optarg);
1278 if (r < 0)
1279 return log_oom();
1280
1281 arg_settings_mask |= SETTING_WORKING_DIRECTORY;
1282 break;
1283
1284 case ARG_PIVOT_ROOT:
1285 r = pivot_root_parse(&arg_pivot_root_new, &arg_pivot_root_old, optarg);
1286 if (r < 0)
1287 return log_error_errno(r, "Failed to parse --pivot-root= argument %s: %m", optarg);
1288
1289 arg_settings_mask |= SETTING_PIVOT_ROOT;
1290 break;
1291
1292 case ARG_NOTIFY_READY:
1293 r = parse_boolean(optarg);
1294 if (r < 0)
1295 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
1296 "%s is not a valid notify mode. Valid modes are: yes, no, and ready.", optarg);
1297 arg_notify_ready = r;
1298 arg_settings_mask |= SETTING_NOTIFY_READY;
1299 break;
1300
1301 case ARG_ROOT_HASH: {
1302 void *k;
1303 size_t l;
1304
1305 r = unhexmem(optarg, strlen(optarg), &k, &l);
1306 if (r < 0)
1307 return log_error_errno(r, "Failed to parse root hash: %s", optarg);
1308 if (l < sizeof(sd_id128_t)) {
1309 free(k);
1310 return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Root hash must be at least 128bit long: %s", optarg);
1311 }
1312
1313 free(arg_root_hash);
1314 arg_root_hash = k;
1315 arg_root_hash_size = l;
1316 break;
1317 }
1318
1319 case ARG_SYSTEM_CALL_FILTER: {
1320 bool negative;
1321 const char *items;
1322
1323 negative = optarg[0] == '~';
1324 items = negative ? optarg + 1 : optarg;
1325
1326 for (;;) {
1327 _cleanup_free_ char *word = NULL;
1328
1329 r = extract_first_word(&items, &word, NULL, 0);
1330 if (r == 0)
1331 break;
1332 if (r == -ENOMEM)
1333 return log_oom();
1334 if (r < 0)
1335 return log_error_errno(r, "Failed to parse system call filter: %m");
1336
1337 if (negative)
1338 r = strv_extend(&arg_syscall_blacklist, word);
1339 else
1340 r = strv_extend(&arg_syscall_whitelist, word);
1341 if (r < 0)
1342 return log_oom();
1343 }
1344
1345 arg_settings_mask |= SETTING_SYSCALL_FILTER;
1346 break;
1347 }
1348
1349 case ARG_RLIMIT: {
1350 const char *eq;
1351 _cleanup_free_ char *name = NULL;
1352 int rl;
1353
1354 if (streq(optarg, "help")) {
1355 DUMP_STRING_TABLE(rlimit, int, _RLIMIT_MAX);
1356 return 0;
1357 }
1358
1359 eq = strchr(optarg, '=');
1360 if (!eq)
1361 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
1362 "--rlimit= expects an '=' assignment.");
1363
1364 name = strndup(optarg, eq - optarg);
1365 if (!name)
1366 return log_oom();
1367
1368 rl = rlimit_from_string_harder(name);
1369 if (rl < 0)
1370 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
1371 "Unknown resource limit: %s", name);
1372
1373 if (!arg_rlimit[rl]) {
1374 arg_rlimit[rl] = new0(struct rlimit, 1);
1375 if (!arg_rlimit[rl])
1376 return log_oom();
1377 }
1378
1379 r = rlimit_parse(rl, eq + 1, arg_rlimit[rl]);
1380 if (r < 0)
1381 return log_error_errno(r, "Failed to parse resource limit: %s", eq + 1);
1382
1383 arg_settings_mask |= SETTING_RLIMIT_FIRST << rl;
1384 break;
1385 }
1386
1387 case ARG_OOM_SCORE_ADJUST:
1388 r = parse_oom_score_adjust(optarg, &arg_oom_score_adjust);
1389 if (r < 0)
1390 return log_error_errno(r, "Failed to parse --oom-score-adjust= parameter: %s", optarg);
1391
1392 arg_oom_score_adjust_set = true;
1393 arg_settings_mask |= SETTING_OOM_SCORE_ADJUST;
1394 break;
1395
1396 case ARG_CPU_AFFINITY: {
1397 CPUSet cpuset;
1398
1399 r = parse_cpu_set(optarg, &cpuset);
1400 if (r < 0)
1401 return log_error_errno(r, "Failed to parse CPU affinity mask %s: %m", optarg);
1402
1403 cpu_set_reset(&arg_cpu_set);
1404 arg_cpu_set = cpuset;
1405 arg_settings_mask |= SETTING_CPU_AFFINITY;
1406 break;
1407 }
1408
1409 case ARG_RESOLV_CONF:
1410 if (streq(optarg, "help")) {
1411 DUMP_STRING_TABLE(resolv_conf_mode, ResolvConfMode, _RESOLV_CONF_MODE_MAX);
1412 return 0;
1413 }
1414
1415 arg_resolv_conf = resolv_conf_mode_from_string(optarg);
1416 if (arg_resolv_conf < 0)
1417 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
1418 "Failed to parse /etc/resolv.conf mode: %s", optarg);
1419
1420 arg_settings_mask |= SETTING_RESOLV_CONF;
1421 break;
1422
1423 case ARG_TIMEZONE:
1424 if (streq(optarg, "help")) {
1425 DUMP_STRING_TABLE(timezone_mode, TimezoneMode, _TIMEZONE_MODE_MAX);
1426 return 0;
1427 }
1428
1429 arg_timezone = timezone_mode_from_string(optarg);
1430 if (arg_timezone < 0)
1431 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
1432 "Failed to parse /etc/localtime mode: %s", optarg);
1433
1434 arg_settings_mask |= SETTING_TIMEZONE;
1435 break;
1436
1437 case ARG_CONSOLE:
1438 r = handle_arg_console(optarg);
1439 if (r <= 0)
1440 return r;
1441 break;
1442
1443 case 'P':
1444 case ARG_PIPE:
1445 r = handle_arg_console("pipe");
1446 if (r <= 0)
1447 return r;
1448 break;
1449
1450 case ARG_NO_PAGER:
1451 arg_pager_flags |= PAGER_DISABLE;
1452 break;
1453
1454 case '?':
1455 return -EINVAL;
1456
1457 default:
1458 assert_not_reached("Unhandled option");
1459 }
1460
1461 if (argc > optind) {
1462 strv_free(arg_parameters);
1463 arg_parameters = strv_copy(argv + optind);
1464 if (!arg_parameters)
1465 return log_oom();
1466
1467 arg_settings_mask |= SETTING_START_MODE;
1468 }
1469
1470 if (arg_ephemeral && arg_template && !arg_directory)
1471 /* User asked for ephemeral execution but specified --template= instead of --directory=. Semantically
1472 * such an invocation makes some sense, see https://github.com/systemd/systemd/issues/3667. Let's
1473 * accept this here, and silently make "--ephemeral --template=" equivalent to "--ephemeral
1474 * --directory=". */
1475 arg_directory = TAKE_PTR(arg_template);
1476
1477 arg_caps_retain = (arg_caps_retain | plus | (arg_private_network ? UINT64_C(1) << CAP_NET_ADMIN : 0)) & ~minus;
1478
1479 /* Make sure to parse environment before we reset the settings mask below */
1480 r = parse_environment();
1481 if (r < 0)
1482 return r;
1483
1484 /* Load all settings from .nspawn files */
1485 if (mask_no_settings)
1486 arg_settings_mask = 0;
1487
1488 /* Don't load any settings from .nspawn files */
1489 if (mask_all_settings)
1490 arg_settings_mask = _SETTINGS_MASK_ALL;
1491
1492 return 1;
1493 }
1494
1495 static int verify_arguments(void) {
1496 int r;
1497
1498 if (arg_start_mode == START_PID2 && arg_unified_cgroup_hierarchy == CGROUP_UNIFIED_UNKNOWN) {
1499 /* If we are running the stub init in the container, we don't need to look at what the init
1500 * in the container supports, because we are not using it. Let's immediately pick the right
1501 * setting based on the host system configuration.
1502 *
1503 * We only do this, if the user didn't use an environment variable to override the detection.
1504 */
1505
1506 r = cg_all_unified();
1507 if (r < 0)
1508 return log_error_errno(r, "Failed to determine whether we are in all unified mode.");
1509 if (r > 0)
1510 arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_ALL;
1511 else if (cg_unified_controller(SYSTEMD_CGROUP_CONTROLLER) > 0)
1512 arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_SYSTEMD;
1513 else
1514 arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_NONE;
1515 }
1516
1517 if (arg_userns_mode != USER_NAMESPACE_NO)
1518 arg_mount_settings |= MOUNT_USE_USERNS;
1519
1520 if (arg_private_network)
1521 arg_mount_settings |= MOUNT_APPLY_APIVFS_NETNS;
1522
1523 if (!(arg_clone_ns_flags & CLONE_NEWPID) ||
1524 !(arg_clone_ns_flags & CLONE_NEWUTS)) {
1525 arg_register = false;
1526 if (arg_start_mode != START_PID1)
1527 return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "--boot cannot be used without namespacing.");
1528 }
1529
1530 if (arg_userns_mode == USER_NAMESPACE_PICK)
1531 arg_userns_chown = true;
1532
1533 if (arg_start_mode == START_BOOT && arg_kill_signal <= 0)
1534 arg_kill_signal = SIGRTMIN+3;
1535
1536 if (arg_volatile_mode != VOLATILE_NO) /* Make sure all file systems contained in the image are mounted read-only if we are in volatile mode */
1537 arg_read_only = true;
1538
1539 if (has_custom_root_mount(arg_custom_mounts, arg_n_custom_mounts))
1540 arg_read_only = true;
1541
1542 if (arg_keep_unit && arg_register && cg_pid_get_owner_uid(0, NULL) >= 0)
1543 /* Save the user from accidentally registering either user-$SESSION.scope or user@.service.
1544 * The latter is not technically a user session, but we don't need to labour the point. */
1545 return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "--keep-unit --register=yes may not be used when invoked from a user session.");
1546
1547 if (arg_directory && arg_image)
1548 return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "--directory= and --image= may not be combined.");
1549
1550 if (arg_template && arg_image)
1551 return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "--template= and --image= may not be combined.");
1552
1553 if (arg_template && !(arg_directory || arg_machine))
1554 return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "--template= needs --directory= or --machine=.");
1555
1556 if (arg_ephemeral && arg_template)
1557 return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "--ephemeral and --template= may not be combined.");
1558
1559 if (arg_ephemeral && !IN_SET(arg_link_journal, LINK_NO, LINK_AUTO))
1560 return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "--ephemeral and --link-journal= may not be combined.");
1561
1562 if (arg_userns_mode != USER_NAMESPACE_NO && !userns_supported())
1563 return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "--private-users= is not supported, kernel compiled without user namespace support.");
1564
1565 if (arg_userns_chown && arg_read_only)
1566 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
1567 "--read-only and --private-users-chown may not be combined.");
1568
1569 /* We don't support --private-users-chown together with any of the volatile modes since we couldn't
1570 * change the read-only part of the tree (i.e. /usr) anyway, or because it would trigger a massive
1571 * copy-up (in case of overlay) making the entire exercise pointless. */
1572 if (arg_userns_chown && arg_volatile_mode != VOLATILE_NO)
1573 return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "--volatile= and --private-users-chown may not be combined.");
1574
1575 /* If --network-namespace-path is given with any other network-related option (except --private-network),
1576 * we need to error out, to avoid conflicts between different network options. */
1577 if (arg_network_namespace_path &&
1578 (arg_network_interfaces || arg_network_macvlan ||
1579 arg_network_ipvlan || arg_network_veth_extra ||
1580 arg_network_bridge || arg_network_zone ||
1581 arg_network_veth))
1582 return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "--network-namespace-path= cannot be combined with other network options.");
1583
1584 if (arg_network_bridge && arg_network_zone)
1585 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
1586 "--network-bridge= and --network-zone= may not be combined.");
1587
1588 if (arg_userns_mode != USER_NAMESPACE_NO && (arg_mount_settings & MOUNT_APPLY_APIVFS_NETNS) && !arg_private_network)
1589 return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Invalid namespacing settings. Mounting sysfs with --private-users requires --private-network.");
1590
1591 if (arg_userns_mode != USER_NAMESPACE_NO && !(arg_mount_settings & MOUNT_APPLY_APIVFS_RO))
1592 return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Cannot combine --private-users with read-write mounts.");
1593
1594 if (arg_expose_ports && !arg_private_network)
1595 return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Cannot use --port= without private networking.");
1596
1597 #if ! HAVE_LIBIPTC
1598 if (arg_expose_ports)
1599 return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "--port= is not supported, compiled without libiptc support.");
1600 #endif
1601
1602 r = custom_mount_check_all();
1603 if (r < 0)
1604 return r;
1605
1606 return 0;
1607 }
1608
1609 static int userns_lchown(const char *p, uid_t uid, gid_t gid) {
1610 assert(p);
1611
1612 if (arg_userns_mode == USER_NAMESPACE_NO)
1613 return 0;
1614
1615 if (uid == UID_INVALID && gid == GID_INVALID)
1616 return 0;
1617
1618 if (uid != UID_INVALID) {
1619 uid += arg_uid_shift;
1620
1621 if (uid < arg_uid_shift || uid >= arg_uid_shift + arg_uid_range)
1622 return -EOVERFLOW;
1623 }
1624
1625 if (gid != GID_INVALID) {
1626 gid += (gid_t) arg_uid_shift;
1627
1628 if (gid < (gid_t) arg_uid_shift || gid >= (gid_t) (arg_uid_shift + arg_uid_range))
1629 return -EOVERFLOW;
1630 }
1631
1632 if (lchown(p, uid, gid) < 0)
1633 return -errno;
1634
1635 return 0;
1636 }
1637
1638 static int userns_mkdir(const char *root, const char *path, mode_t mode, uid_t uid, gid_t gid) {
1639 const char *q;
1640 int r;
1641
1642 q = prefix_roota(root, path);
1643 r = mkdir_errno_wrapper(q, mode);
1644 if (r == -EEXIST)
1645 return 0;
1646 if (r < 0)
1647 return r;
1648
1649 return userns_lchown(q, uid, gid);
1650 }
1651
1652 static const char *timezone_from_path(const char *path) {
1653 return PATH_STARTSWITH_SET(
1654 path,
1655 "../usr/share/zoneinfo/",
1656 "/usr/share/zoneinfo/");
1657 }
1658
1659 static bool etc_writable(void) {
1660 return !arg_read_only || IN_SET(arg_volatile_mode, VOLATILE_YES, VOLATILE_OVERLAY);
1661 }
1662
1663 static int setup_timezone(const char *dest) {
1664 _cleanup_free_ char *p = NULL, *etc = NULL;
1665 const char *where, *check;
1666 TimezoneMode m;
1667 int r;
1668
1669 assert(dest);
1670
1671 if (IN_SET(arg_timezone, TIMEZONE_AUTO, TIMEZONE_SYMLINK)) {
1672 r = readlink_malloc("/etc/localtime", &p);
1673 if (r == -ENOENT && arg_timezone == TIMEZONE_AUTO)
1674 m = etc_writable() ? TIMEZONE_DELETE : TIMEZONE_OFF;
1675 else if (r == -EINVAL && arg_timezone == TIMEZONE_AUTO) /* regular file? */
1676 m = etc_writable() ? TIMEZONE_COPY : TIMEZONE_BIND;
1677 else if (r < 0) {
1678 log_warning_errno(r, "Failed to read host's /etc/localtime symlink, not updating container timezone: %m");
1679 /* To handle warning, delete /etc/localtime and replace it with a symbolic link to a time zone data
1680 * file.
1681 *
1682 * Example:
1683 * ln -s /usr/share/zoneinfo/UTC /etc/localtime
1684 */
1685 return 0;
1686 } else if (arg_timezone == TIMEZONE_AUTO)
1687 m = etc_writable() ? TIMEZONE_SYMLINK : TIMEZONE_BIND;
1688 else
1689 m = arg_timezone;
1690 } else
1691 m = arg_timezone;
1692
1693 if (m == TIMEZONE_OFF)
1694 return 0;
1695
1696 r = chase_symlinks("/etc", dest, CHASE_PREFIX_ROOT, &etc, NULL);
1697 if (r < 0) {
1698 log_warning_errno(r, "Failed to resolve /etc path in container, ignoring: %m");
1699 return 0;
1700 }
1701
1702 where = strjoina(etc, "/localtime");
1703
1704 switch (m) {
1705
1706 case TIMEZONE_DELETE:
1707 if (unlink(where) < 0)
1708 log_full_errno(errno == ENOENT ? LOG_DEBUG : LOG_WARNING, errno, "Failed to remove '%s', ignoring: %m", where);
1709
1710 return 0;
1711
1712 case TIMEZONE_SYMLINK: {
1713 _cleanup_free_ char *q = NULL;
1714 const char *z, *what;
1715
1716 z = timezone_from_path(p);
1717 if (!z) {
1718 log_warning("/etc/localtime does not point into /usr/share/zoneinfo/, not updating container timezone.");
1719 return 0;
1720 }
1721
1722 r = readlink_malloc(where, &q);
1723 if (r >= 0 && streq_ptr(timezone_from_path(q), z))
1724 return 0; /* Already pointing to the right place? Then do nothing .. */
1725
1726 check = strjoina(dest, "/usr/share/zoneinfo/", z);
1727 r = chase_symlinks(check, dest, 0, NULL, NULL);
1728 if (r < 0)
1729 log_debug_errno(r, "Timezone %s does not exist (or is not accessible) in container, not creating symlink: %m", z);
1730 else {
1731 if (unlink(where) < 0 && errno != ENOENT) {
1732 log_full_errno(IN_SET(errno, EROFS, EACCES, EPERM) ? LOG_DEBUG : LOG_WARNING, /* Don't complain on read-only images */
1733 errno, "Failed to remove existing timezone info %s in container, ignoring: %m", where);
1734 return 0;
1735 }
1736
1737 what = strjoina("../usr/share/zoneinfo/", z);
1738 if (symlink(what, where) < 0) {
1739 log_full_errno(IN_SET(errno, EROFS, EACCES, EPERM) ? LOG_DEBUG : LOG_WARNING,
1740 errno, "Failed to correct timezone of container, ignoring: %m");
1741 return 0;
1742 }
1743
1744 break;
1745 }
1746
1747 _fallthrough_;
1748 }
1749
1750 case TIMEZONE_BIND: {
1751 _cleanup_free_ char *resolved = NULL;
1752 int found;
1753
1754 found = chase_symlinks(where, dest, CHASE_NONEXISTENT, &resolved, NULL);
1755 if (found < 0) {
1756 log_warning_errno(found, "Failed to resolve /etc/localtime path in container, ignoring: %m");
1757 return 0;
1758 }
1759
1760 if (found == 0) /* missing? */
1761 (void) touch(resolved);
1762
1763 r = mount_verbose(LOG_WARNING, "/etc/localtime", resolved, NULL, MS_BIND, NULL);
1764 if (r >= 0)
1765 return mount_verbose(LOG_ERR, NULL, resolved, NULL, MS_BIND|MS_REMOUNT|MS_RDONLY|MS_NOSUID|MS_NODEV, NULL);
1766
1767 _fallthrough_;
1768 }
1769
1770 case TIMEZONE_COPY:
1771 /* If mounting failed, try to copy */
1772 r = copy_file_atomic("/etc/localtime", where, 0644, 0, 0, COPY_REFLINK|COPY_REPLACE);
1773 if (r < 0) {
1774 log_full_errno(IN_SET(r, -EROFS, -EACCES, -EPERM) ? LOG_DEBUG : LOG_WARNING, r,
1775 "Failed to copy /etc/localtime to %s, ignoring: %m", where);
1776 return 0;
1777 }
1778
1779 break;
1780
1781 default:
1782 assert_not_reached("unexpected mode");
1783 }
1784
1785 /* Fix permissions of the symlink or file copy we just created */
1786 r = userns_lchown(where, 0, 0);
1787 if (r < 0)
1788 log_warning_errno(r, "Failed to chown /etc/localtime, ignoring: %m");
1789
1790 return 0;
1791 }
1792
1793 static int have_resolv_conf(const char *path) {
1794 assert(path);
1795
1796 if (access(path, F_OK) < 0) {
1797 if (errno == ENOENT)
1798 return 0;
1799
1800 return log_debug_errno(errno, "Failed to determine whether '%s' is available: %m", path);
1801 }
1802
1803 return 1;
1804 }
1805
1806 static int resolved_listening(void) {
1807 _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
1808 _cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL;
1809 _cleanup_free_ char *dns_stub_listener_mode = NULL;
1810 int r;
1811
1812 /* Check if resolved is listening */
1813
1814 r = sd_bus_open_system(&bus);
1815 if (r < 0)
1816 return log_debug_errno(r, "Failed to open system bus: %m");
1817
1818 r = bus_name_has_owner(bus, "org.freedesktop.resolve1", NULL);
1819 if (r < 0)
1820 return log_debug_errno(r, "Failed to check whether the 'org.freedesktop.resolve1' bus name is taken: %m");
1821 if (r == 0)
1822 return 0;
1823
1824 r = sd_bus_get_property_string(bus,
1825 "org.freedesktop.resolve1",
1826 "/org/freedesktop/resolve1",
1827 "org.freedesktop.resolve1.Manager",
1828 "DNSStubListener",
1829 &error,
1830 &dns_stub_listener_mode);
1831 if (r < 0)
1832 return log_debug_errno(r, "Failed to query DNSStubListener property: %s", bus_error_message(&error, r));
1833
1834 return STR_IN_SET(dns_stub_listener_mode, "udp", "yes");
1835 }
1836
1837 static int setup_resolv_conf(const char *dest) {
1838 _cleanup_free_ char *etc = NULL;
1839 const char *where, *what;
1840 ResolvConfMode m;
1841 int r;
1842
1843 assert(dest);
1844
1845 if (arg_resolv_conf == RESOLV_CONF_AUTO) {
1846 if (arg_private_network)
1847 m = RESOLV_CONF_OFF;
1848 else if (have_resolv_conf(PRIVATE_STUB_RESOLV_CONF) > 0 && resolved_listening() > 0)
1849 m = etc_writable() ? RESOLV_CONF_COPY_STUB : RESOLV_CONF_BIND_STUB;
1850 else if (have_resolv_conf("/etc/resolv.conf") > 0)
1851 m = etc_writable() ? RESOLV_CONF_COPY_HOST : RESOLV_CONF_BIND_HOST;
1852 else
1853 m = etc_writable() ? RESOLV_CONF_DELETE : RESOLV_CONF_OFF;
1854
1855 } else
1856 m = arg_resolv_conf;
1857
1858 if (m == RESOLV_CONF_OFF)
1859 return 0;
1860
1861 r = chase_symlinks("/etc", dest, CHASE_PREFIX_ROOT, &etc, NULL);
1862 if (r < 0) {
1863 log_warning_errno(r, "Failed to resolve /etc path in container, ignoring: %m");
1864 return 0;
1865 }
1866
1867 where = strjoina(etc, "/resolv.conf");
1868
1869 if (m == RESOLV_CONF_DELETE) {
1870 if (unlink(where) < 0)
1871 log_full_errno(errno == ENOENT ? LOG_DEBUG : LOG_WARNING, errno, "Failed to remove '%s', ignoring: %m", where);
1872
1873 return 0;
1874 }
1875
1876 if (IN_SET(m, RESOLV_CONF_BIND_STATIC, RESOLV_CONF_REPLACE_STATIC, RESOLV_CONF_COPY_STATIC))
1877 what = PRIVATE_STATIC_RESOLV_CONF;
1878 else if (IN_SET(m, RESOLV_CONF_BIND_UPLINK, RESOLV_CONF_REPLACE_UPLINK, RESOLV_CONF_COPY_UPLINK))
1879 what = PRIVATE_UPLINK_RESOLV_CONF;
1880 else if (IN_SET(m, RESOLV_CONF_BIND_STUB, RESOLV_CONF_REPLACE_STUB, RESOLV_CONF_COPY_STUB))
1881 what = PRIVATE_STUB_RESOLV_CONF;
1882 else
1883 what = "/etc/resolv.conf";
1884
1885 if (IN_SET(m, RESOLV_CONF_BIND_HOST, RESOLV_CONF_BIND_STATIC, RESOLV_CONF_BIND_UPLINK, RESOLV_CONF_BIND_STUB)) {
1886 _cleanup_free_ char *resolved = NULL;
1887 int found;
1888
1889 found = chase_symlinks(where, dest, CHASE_NONEXISTENT, &resolved, NULL);
1890 if (found < 0) {
1891 log_warning_errno(found, "Failed to resolve /etc/resolv.conf path in container, ignoring: %m");
1892 return 0;
1893 }
1894
1895 if (found == 0) /* missing? */
1896 (void) touch(resolved);
1897
1898 r = mount_verbose(LOG_WARNING, what, resolved, NULL, MS_BIND, NULL);
1899 if (r >= 0)
1900 return mount_verbose(LOG_ERR, NULL, resolved, NULL, MS_BIND|MS_REMOUNT|MS_RDONLY|MS_NOSUID|MS_NODEV, NULL);
1901
1902 /* If that didn't work, let's copy the file */
1903 }
1904
1905 if (IN_SET(m, RESOLV_CONF_REPLACE_HOST, RESOLV_CONF_REPLACE_STATIC, RESOLV_CONF_REPLACE_UPLINK, RESOLV_CONF_REPLACE_STUB))
1906 r = copy_file_atomic(what, where, 0644, 0, 0, COPY_REFLINK|COPY_REPLACE);
1907 else
1908 r = copy_file(what, where, O_TRUNC|O_NOFOLLOW, 0644, 0, 0, COPY_REFLINK);
1909 if (r < 0) {
1910 /* If the file already exists as symlink, let's suppress the warning, under the assumption that
1911 * resolved or something similar runs inside and the symlink points there.
1912 *
1913 * If the disk image is read-only, there's also no point in complaining.
1914 */
1915 log_full_errno(!IN_SET(RESOLV_CONF_COPY_HOST, RESOLV_CONF_COPY_STATIC, RESOLV_CONF_COPY_UPLINK, RESOLV_CONF_COPY_STUB) &&
1916 IN_SET(r, -ELOOP, -EROFS, -EACCES, -EPERM) ? LOG_DEBUG : LOG_WARNING, r,
1917 "Failed to copy /etc/resolv.conf to %s, ignoring: %m", where);
1918 return 0;
1919 }
1920
1921 r = userns_lchown(where, 0, 0);
1922 if (r < 0)
1923 log_warning_errno(r, "Failed to chown /etc/resolv.conf, ignoring: %m");
1924
1925 return 0;
1926 }
1927
1928 static int setup_boot_id(void) {
1929 _cleanup_(unlink_and_freep) char *from = NULL;
1930 _cleanup_free_ char *path = NULL;
1931 sd_id128_t rnd = SD_ID128_NULL;
1932 const char *to;
1933 int r;
1934
1935 /* Generate a new randomized boot ID, so that each boot-up of the container gets a new one */
1936
1937 r = tempfn_random_child("/run", "proc-sys-kernel-random-boot-id", &path);
1938 if (r < 0)
1939 return log_error_errno(r, "Failed to generate random boot ID path: %m");
1940
1941 r = sd_id128_randomize(&rnd);
1942 if (r < 0)
1943 return log_error_errno(r, "Failed to generate random boot id: %m");
1944
1945 r = id128_write(path, ID128_UUID, rnd, false);
1946 if (r < 0)
1947 return log_error_errno(r, "Failed to write boot id: %m");
1948
1949 from = TAKE_PTR(path);
1950 to = "/proc/sys/kernel/random/boot_id";
1951
1952 r = mount_verbose(LOG_ERR, from, to, NULL, MS_BIND, NULL);
1953 if (r < 0)
1954 return r;
1955
1956 return mount_verbose(LOG_ERR, NULL, to, NULL, MS_BIND|MS_REMOUNT|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV, NULL);
1957 }
1958
1959 static int copy_devnodes(const char *dest) {
1960 static const char devnodes[] =
1961 "null\0"
1962 "zero\0"
1963 "full\0"
1964 "random\0"
1965 "urandom\0"
1966 "tty\0"
1967 "net/tun\0";
1968
1969 _cleanup_umask_ mode_t u;
1970 const char *d;
1971 int r = 0;
1972
1973 assert(dest);
1974
1975 u = umask(0000);
1976
1977 /* Create /dev/net, so that we can create /dev/net/tun in it */
1978 if (userns_mkdir(dest, "/dev/net", 0755, 0, 0) < 0)
1979 return log_error_errno(r, "Failed to create /dev/net directory: %m");
1980
1981 NULSTR_FOREACH(d, devnodes) {
1982 _cleanup_free_ char *from = NULL, *to = NULL;
1983 struct stat st;
1984
1985 from = path_join("/dev/", d);
1986 if (!from)
1987 return log_oom();
1988
1989 to = path_join(dest, from);
1990 if (!to)
1991 return log_oom();
1992
1993 if (stat(from, &st) < 0) {
1994
1995 if (errno != ENOENT)
1996 return log_error_errno(errno, "Failed to stat %s: %m", from);
1997
1998 } else if (!S_ISCHR(st.st_mode) && !S_ISBLK(st.st_mode))
1999 return log_error_errno(SYNTHETIC_ERRNO(EIO),
2000 "%s is not a char or block device, cannot copy.", from);
2001 else {
2002 _cleanup_free_ char *sl = NULL, *prefixed = NULL, *dn = NULL, *t = NULL;
2003
2004 if (mknod(to, st.st_mode, st.st_rdev) < 0) {
2005 /* Explicitly warn the user when /dev is already populated. */
2006 if (errno == EEXIST)
2007 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);
2008 if (errno != EPERM)
2009 return log_error_errno(errno, "mknod(%s) failed: %m", to);
2010
2011 /* Some systems abusively restrict mknod but allow bind mounts. */
2012 r = touch(to);
2013 if (r < 0)
2014 return log_error_errno(r, "touch (%s) failed: %m", to);
2015 r = mount_verbose(LOG_DEBUG, from, to, NULL, MS_BIND, NULL);
2016 if (r < 0)
2017 return log_error_errno(r, "Both mknod and bind mount (%s) failed: %m", to);
2018 }
2019
2020 r = userns_lchown(to, 0, 0);
2021 if (r < 0)
2022 return log_error_errno(r, "chown() of device node %s failed: %m", to);
2023
2024 dn = path_join("/dev", S_ISCHR(st.st_mode) ? "char" : "block");
2025 if (!dn)
2026 return log_oom();
2027
2028 r = userns_mkdir(dest, dn, 0755, 0, 0);
2029 if (r < 0)
2030 return log_error_errno(r, "Failed to create '%s': %m", dn);
2031
2032 if (asprintf(&sl, "%s/%u:%u", dn, major(st.st_rdev), minor(st.st_rdev)) < 0)
2033 return log_oom();
2034
2035 prefixed = path_join(dest, sl);
2036 if (!prefixed)
2037 return log_oom();
2038
2039 t = path_join("..", d);
2040 if (!t)
2041 return log_oom();
2042
2043 if (symlink(t, prefixed) < 0)
2044 log_debug_errno(errno, "Failed to symlink '%s' to '%s': %m", t, prefixed);
2045 }
2046 }
2047
2048 return r;
2049 }
2050
2051 static int make_extra_nodes(const char *dest) {
2052 _cleanup_umask_ mode_t u;
2053 size_t i;
2054 int r;
2055
2056 u = umask(0000);
2057
2058 for (i = 0; i < arg_n_extra_nodes; i++) {
2059 _cleanup_free_ char *path = NULL;
2060 DeviceNode *n = arg_extra_nodes + i;
2061
2062 path = path_join(dest, n->path);
2063 if (!path)
2064 return log_oom();
2065
2066 if (mknod(path, n->mode, S_ISCHR(n->mode) || S_ISBLK(n->mode) ? makedev(n->major, n->minor) : 0) < 0)
2067 return log_error_errno(errno, "Failed to create device node '%s': %m", path);
2068
2069 r = chmod_and_chown(path, n->mode, n->uid, n->gid);
2070 if (r < 0)
2071 return log_error_errno(r, "Failed to adjust device node ownership of '%s': %m", path);
2072 }
2073
2074 return 0;
2075 }
2076
2077 static int setup_pts(const char *dest) {
2078 _cleanup_free_ char *options = NULL;
2079 const char *p;
2080 int r;
2081
2082 #if HAVE_SELINUX
2083 if (arg_selinux_apifs_context)
2084 (void) asprintf(&options,
2085 "newinstance,ptmxmode=0666,mode=620,gid=" GID_FMT ",context=\"%s\"",
2086 arg_uid_shift + TTY_GID,
2087 arg_selinux_apifs_context);
2088 else
2089 #endif
2090 (void) asprintf(&options,
2091 "newinstance,ptmxmode=0666,mode=620,gid=" GID_FMT,
2092 arg_uid_shift + TTY_GID);
2093
2094 if (!options)
2095 return log_oom();
2096
2097 /* Mount /dev/pts itself */
2098 p = prefix_roota(dest, "/dev/pts");
2099 r = mkdir_errno_wrapper(p, 0755);
2100 if (r < 0)
2101 return log_error_errno(r, "Failed to create /dev/pts: %m");
2102
2103 r = mount_verbose(LOG_ERR, "devpts", p, "devpts", MS_NOSUID|MS_NOEXEC, options);
2104 if (r < 0)
2105 return r;
2106 r = userns_lchown(p, 0, 0);
2107 if (r < 0)
2108 return log_error_errno(r, "Failed to chown /dev/pts: %m");
2109
2110 /* Create /dev/ptmx symlink */
2111 p = prefix_roota(dest, "/dev/ptmx");
2112 if (symlink("pts/ptmx", p) < 0)
2113 return log_error_errno(errno, "Failed to create /dev/ptmx symlink: %m");
2114 r = userns_lchown(p, 0, 0);
2115 if (r < 0)
2116 return log_error_errno(r, "Failed to chown /dev/ptmx: %m");
2117
2118 /* And fix /dev/pts/ptmx ownership */
2119 p = prefix_roota(dest, "/dev/pts/ptmx");
2120 r = userns_lchown(p, 0, 0);
2121 if (r < 0)
2122 return log_error_errno(r, "Failed to chown /dev/pts/ptmx: %m");
2123
2124 return 0;
2125 }
2126
2127 static int setup_stdio_as_dev_console(void) {
2128 int terminal;
2129 int r;
2130
2131 terminal = open_terminal("/dev/console", O_RDWR);
2132 if (terminal < 0)
2133 return log_error_errno(terminal, "Failed to open console: %m");
2134
2135 /* Make sure we can continue logging to the original stderr, even if
2136 * stderr points elsewhere now */
2137 r = log_dup_console();
2138 if (r < 0)
2139 return log_error_errno(r, "Failed to duplicate stderr: %m");
2140
2141 /* invalidates 'terminal' on success and failure */
2142 r = rearrange_stdio(terminal, terminal, terminal);
2143 if (r < 0)
2144 return log_error_errno(r, "Failed to move console to stdin/stdout/stderr: %m");
2145
2146 return 0;
2147 }
2148
2149 static int setup_dev_console(const char *console) {
2150 _cleanup_free_ char *p = NULL;
2151 int r;
2152
2153 /* Create /dev/console symlink */
2154 r = path_make_relative("/dev", console, &p);
2155 if (r < 0)
2156 return log_error_errno(r, "Failed to create relative path: %m");
2157
2158 if (symlink(p, "/dev/console") < 0)
2159 return log_error_errno(errno, "Failed to create /dev/console symlink: %m");
2160
2161 return 0;
2162 }
2163
2164 static int setup_keyring(void) {
2165 key_serial_t keyring;
2166
2167 /* Allocate a new session keyring for the container. This makes sure the keyring of the session systemd-nspawn
2168 * was invoked from doesn't leak into the container. Note that by default we block keyctl() and request_key()
2169 * anyway via seccomp so doing this operation isn't strictly necessary, but in case people explicitly whitelist
2170 * these system calls let's make sure we don't leak anything into the container. */
2171
2172 keyring = keyctl(KEYCTL_JOIN_SESSION_KEYRING, 0, 0, 0, 0);
2173 if (keyring == -1) {
2174 if (errno == ENOSYS)
2175 log_debug_errno(errno, "Kernel keyring not supported, ignoring.");
2176 else if (IN_SET(errno, EACCES, EPERM))
2177 log_debug_errno(errno, "Kernel keyring access prohibited, ignoring.");
2178 else
2179 return log_error_errno(errno, "Setting up kernel keyring failed: %m");
2180 }
2181
2182 return 0;
2183 }
2184
2185 static int setup_kmsg(int kmsg_socket) {
2186 _cleanup_(unlink_and_freep) char *from = NULL;
2187 _cleanup_free_ char *fifo = NULL;
2188 _cleanup_close_ int fd = -1;
2189 _cleanup_umask_ mode_t u;
2190 int r;
2191
2192 assert(kmsg_socket >= 0);
2193
2194 u = umask(0000);
2195
2196 /* We create the kmsg FIFO as as temporary file in /run, but immediately delete it after bind mounting it to
2197 * /proc/kmsg. While FIFOs on the reading side behave very similar to /proc/kmsg, their writing side behaves
2198 * differently from /dev/kmsg in that writing blocks when nothing is reading. In order to avoid any problems
2199 * with containers deadlocking due to this we simply make /dev/kmsg unavailable to the container. */
2200
2201 r = tempfn_random_child("/run", "proc-kmsg", &fifo);
2202 if (r < 0)
2203 return log_error_errno(r, "Failed to generate kmsg path: %m");
2204
2205 if (mkfifo(fifo, 0600) < 0)
2206 return log_error_errno(errno, "mkfifo() for /run/kmsg failed: %m");
2207
2208 from = TAKE_PTR(fifo);
2209
2210 r = mount_verbose(LOG_ERR, from, "/proc/kmsg", NULL, MS_BIND, NULL);
2211 if (r < 0)
2212 return r;
2213
2214 fd = open(from, O_RDWR|O_NONBLOCK|O_CLOEXEC);
2215 if (fd < 0)
2216 return log_error_errno(errno, "Failed to open fifo: %m");
2217
2218 /* Store away the fd in the socket, so that it stays open as long as we run the child */
2219 r = send_one_fd(kmsg_socket, fd, 0);
2220 if (r < 0)
2221 return log_error_errno(r, "Failed to send FIFO fd: %m");
2222
2223 return 0;
2224 }
2225
2226 static int on_address_change(sd_netlink *rtnl, sd_netlink_message *m, void *userdata) {
2227 union in_addr_union *exposed = userdata;
2228
2229 assert(rtnl);
2230 assert(m);
2231 assert(exposed);
2232
2233 expose_port_execute(rtnl, arg_expose_ports, exposed);
2234 return 0;
2235 }
2236
2237 static int setup_hostname(void) {
2238 int r;
2239
2240 if ((arg_clone_ns_flags & CLONE_NEWUTS) == 0)
2241 return 0;
2242
2243 r = sethostname_idempotent(arg_hostname ?: arg_machine);
2244 if (r < 0)
2245 return log_error_errno(r, "Failed to set hostname: %m");
2246
2247 return 0;
2248 }
2249
2250 static int setup_journal(const char *directory) {
2251 _cleanup_free_ char *d = NULL;
2252 char id[SD_ID128_STRING_MAX];
2253 const char *dirname, *p, *q;
2254 sd_id128_t this_id;
2255 bool try;
2256 int r;
2257
2258 /* Don't link journals in ephemeral mode */
2259 if (arg_ephemeral)
2260 return 0;
2261
2262 if (arg_link_journal == LINK_NO)
2263 return 0;
2264
2265 try = arg_link_journal_try || arg_link_journal == LINK_AUTO;
2266
2267 r = sd_id128_get_machine(&this_id);
2268 if (r < 0)
2269 return log_error_errno(r, "Failed to retrieve machine ID: %m");
2270
2271 if (sd_id128_equal(arg_uuid, this_id)) {
2272 log_full(try ? LOG_WARNING : LOG_ERR,
2273 "Host and machine ids are equal (%s): refusing to link journals", sd_id128_to_string(arg_uuid, id));
2274 if (try)
2275 return 0;
2276 return -EEXIST;
2277 }
2278
2279 FOREACH_STRING(dirname, "/var", "/var/log", "/var/log/journal") {
2280 r = userns_mkdir(directory, dirname, 0755, 0, 0);
2281 if (r < 0) {
2282 bool ignore = r == -EROFS && try;
2283 log_full_errno(ignore ? LOG_DEBUG : LOG_ERR, r,
2284 "Failed to create %s%s: %m", dirname, ignore ? ", ignoring" : "");
2285 return ignore ? 0 : r;
2286 }
2287 }
2288
2289 (void) sd_id128_to_string(arg_uuid, id);
2290
2291 p = strjoina("/var/log/journal/", id);
2292 q = prefix_roota(directory, p);
2293
2294 if (path_is_mount_point(p, NULL, 0) > 0) {
2295 if (try)
2296 return 0;
2297
2298 return log_error_errno(SYNTHETIC_ERRNO(EEXIST),
2299 "%s: already a mount point, refusing to use for journal", p);
2300 }
2301
2302 if (path_is_mount_point(q, NULL, 0) > 0) {
2303 if (try)
2304 return 0;
2305
2306 return log_error_errno(SYNTHETIC_ERRNO(EEXIST),
2307 "%s: already a mount point, refusing to use for journal", q);
2308 }
2309
2310 r = readlink_and_make_absolute(p, &d);
2311 if (r >= 0) {
2312 if (IN_SET(arg_link_journal, LINK_GUEST, LINK_AUTO) &&
2313 path_equal(d, q)) {
2314
2315 r = userns_mkdir(directory, p, 0755, 0, 0);
2316 if (r < 0)
2317 log_warning_errno(r, "Failed to create directory %s: %m", q);
2318 return 0;
2319 }
2320
2321 if (unlink(p) < 0)
2322 return log_error_errno(errno, "Failed to remove symlink %s: %m", p);
2323 } else if (r == -EINVAL) {
2324
2325 if (arg_link_journal == LINK_GUEST &&
2326 rmdir(p) < 0) {
2327
2328 if (errno == ENOTDIR) {
2329 log_error("%s already exists and is neither a symlink nor a directory", p);
2330 return r;
2331 } else
2332 return log_error_errno(errno, "Failed to remove %s: %m", p);
2333 }
2334 } else if (r != -ENOENT)
2335 return log_error_errno(r, "readlink(%s) failed: %m", p);
2336
2337 if (arg_link_journal == LINK_GUEST) {
2338
2339 if (symlink(q, p) < 0) {
2340 if (try) {
2341 log_debug_errno(errno, "Failed to symlink %s to %s, skipping journal setup: %m", q, p);
2342 return 0;
2343 } else
2344 return log_error_errno(errno, "Failed to symlink %s to %s: %m", q, p);
2345 }
2346
2347 r = userns_mkdir(directory, p, 0755, 0, 0);
2348 if (r < 0)
2349 log_warning_errno(r, "Failed to create directory %s: %m", q);
2350 return 0;
2351 }
2352
2353 if (arg_link_journal == LINK_HOST) {
2354 /* don't create parents here — if the host doesn't have
2355 * permanent journal set up, don't force it here */
2356
2357 r = mkdir_errno_wrapper(p, 0755);
2358 if (r < 0 && r != -EEXIST) {
2359 if (try) {
2360 log_debug_errno(r, "Failed to create %s, skipping journal setup: %m", p);
2361 return 0;
2362 } else
2363 return log_error_errno(r, "Failed to create %s: %m", p);
2364 }
2365
2366 } else if (access(p, F_OK) < 0)
2367 return 0;
2368
2369 if (dir_is_empty(q) == 0)
2370 log_warning("%s is not empty, proceeding anyway.", q);
2371
2372 r = userns_mkdir(directory, p, 0755, 0, 0);
2373 if (r < 0)
2374 return log_error_errno(r, "Failed to create %s: %m", q);
2375
2376 r = mount_verbose(LOG_DEBUG, p, q, NULL, MS_BIND, NULL);
2377 if (r < 0)
2378 return log_error_errno(errno, "Failed to bind mount journal from host into guest: %m");
2379
2380 return 0;
2381 }
2382
2383 static int drop_capabilities(uid_t uid) {
2384 CapabilityQuintet q;
2385
2386 /* Let's initialize all five capability sets to something valid. If the quintet was configured via
2387 * OCI use that, but fill in missing bits. If it wasn't then derive the quintet in full from
2388 * arg_caps_retain. */
2389
2390 if (capability_quintet_is_set(&arg_full_capabilities)) {
2391 q = arg_full_capabilities;
2392
2393 if (q.bounding == (uint64_t) -1)
2394 q.bounding = uid == 0 ? arg_caps_retain : 0;
2395
2396 if (q.effective == (uint64_t) -1)
2397 q.effective = uid == 0 ? q.bounding : 0;
2398
2399 if (q.inheritable == (uint64_t) -1)
2400 q.inheritable = uid == 0 ? q.bounding : 0;
2401
2402 if (q.permitted == (uint64_t) -1)
2403 q.permitted = uid == 0 ? q.bounding : 0;
2404
2405 if (q.ambient == (uint64_t) -1 && ambient_capabilities_supported())
2406 q.ambient = 0;
2407
2408 if (capability_quintet_mangle(&q))
2409 return log_error_errno(SYNTHETIC_ERRNO(EPERM), "Cannot set capabilities that are not in the current bounding set.");
2410
2411 } else {
2412 q = (CapabilityQuintet) {
2413 .bounding = arg_caps_retain,
2414 .effective = uid == 0 ? arg_caps_retain : 0,
2415 .inheritable = uid == 0 ? arg_caps_retain : 0,
2416 .permitted = uid == 0 ? arg_caps_retain : 0,
2417 .ambient = ambient_capabilities_supported() ? 0 : (uint64_t) -1,
2418 };
2419
2420 /* If we're not using OCI, proceed with mangled capabilities (so we don't error out)
2421 * in order to maintain the same behavior as systemd < 242. */
2422 if (capability_quintet_mangle(&q))
2423 log_full(arg_quiet ? LOG_DEBUG : LOG_WARNING,
2424 "Some capabilities will not be set because they are not in the current bounding set.");
2425
2426 }
2427
2428 return capability_quintet_enforce(&q);
2429 }
2430
2431 static int reset_audit_loginuid(void) {
2432 _cleanup_free_ char *p = NULL;
2433 int r;
2434
2435 if ((arg_clone_ns_flags & CLONE_NEWPID) == 0)
2436 return 0;
2437
2438 r = read_one_line_file("/proc/self/loginuid", &p);
2439 if (r == -ENOENT)
2440 return 0;
2441 if (r < 0)
2442 return log_error_errno(r, "Failed to read /proc/self/loginuid: %m");
2443
2444 /* Already reset? */
2445 if (streq(p, "4294967295"))
2446 return 0;
2447
2448 r = write_string_file("/proc/self/loginuid", "4294967295", WRITE_STRING_FILE_DISABLE_BUFFER);
2449 if (r < 0) {
2450 log_error_errno(r,
2451 "Failed to reset audit login UID. This probably means that your kernel is too\n"
2452 "old and you have audit enabled. Note that the auditing subsystem is known to\n"
2453 "be incompatible with containers on old kernels. Please make sure to upgrade\n"
2454 "your kernel or to off auditing with 'audit=0' on the kernel command line before\n"
2455 "using systemd-nspawn. Sleeping for 5s... (%m)");
2456
2457 sleep(5);
2458 }
2459
2460 return 0;
2461 }
2462
2463 static int setup_propagate(const char *root) {
2464 const char *p, *q;
2465 int r;
2466
2467 (void) mkdir_p("/run/systemd/nspawn/", 0755);
2468 (void) mkdir_p("/run/systemd/nspawn/propagate", 0600);
2469 p = strjoina("/run/systemd/nspawn/propagate/", arg_machine);
2470 (void) mkdir_p(p, 0600);
2471
2472 r = userns_mkdir(root, "/run/systemd", 0755, 0, 0);
2473 if (r < 0)
2474 return log_error_errno(r, "Failed to create /run/systemd: %m");
2475
2476 r = userns_mkdir(root, "/run/systemd/nspawn", 0755, 0, 0);
2477 if (r < 0)
2478 return log_error_errno(r, "Failed to create /run/systemd/nspawn: %m");
2479
2480 r = userns_mkdir(root, "/run/systemd/nspawn/incoming", 0600, 0, 0);
2481 if (r < 0)
2482 return log_error_errno(r, "Failed to create /run/systemd/nspawn/incoming: %m");
2483
2484 q = prefix_roota(root, "/run/systemd/nspawn/incoming");
2485 r = mount_verbose(LOG_ERR, p, q, NULL, MS_BIND, NULL);
2486 if (r < 0)
2487 return r;
2488
2489 r = mount_verbose(LOG_ERR, NULL, q, NULL, MS_BIND|MS_REMOUNT|MS_RDONLY, NULL);
2490 if (r < 0)
2491 return r;
2492
2493 /* machined will MS_MOVE into that directory, and that's only
2494 * supported for non-shared mounts. */
2495 return mount_verbose(LOG_ERR, NULL, q, NULL, MS_SLAVE, NULL);
2496 }
2497
2498 static int setup_machine_id(const char *directory) {
2499 const char *etc_machine_id;
2500 sd_id128_t id;
2501 int r;
2502
2503 /* If the UUID in the container is already set, then that's what counts, and we use. If it isn't set, and the
2504 * caller passed --uuid=, then we'll pass it in the $container_uuid env var to PID 1 of the container. The
2505 * assumption is that PID 1 will then write it to /etc/machine-id to make it persistent. If --uuid= is not
2506 * passed we generate a random UUID, and pass it via $container_uuid. In effect this means that /etc/machine-id
2507 * in the container and our idea of the container UUID will always be in sync (at least if PID 1 in the
2508 * container behaves nicely). */
2509
2510 etc_machine_id = prefix_roota(directory, "/etc/machine-id");
2511
2512 r = id128_read(etc_machine_id, ID128_PLAIN, &id);
2513 if (r < 0) {
2514 if (!IN_SET(r, -ENOENT, -ENOMEDIUM)) /* If the file is missing or empty, we don't mind */
2515 return log_error_errno(r, "Failed to read machine ID from container image: %m");
2516
2517 if (sd_id128_is_null(arg_uuid)) {
2518 r = sd_id128_randomize(&arg_uuid);
2519 if (r < 0)
2520 return log_error_errno(r, "Failed to acquire randomized machine UUID: %m");
2521 }
2522 } else {
2523 if (sd_id128_is_null(id))
2524 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
2525 "Machine ID in container image is zero, refusing.");
2526
2527 arg_uuid = id;
2528 }
2529
2530 return 0;
2531 }
2532
2533 static int recursive_chown(const char *directory, uid_t shift, uid_t range) {
2534 int r;
2535
2536 assert(directory);
2537
2538 if (arg_userns_mode == USER_NAMESPACE_NO || !arg_userns_chown)
2539 return 0;
2540
2541 r = path_patch_uid(directory, arg_uid_shift, arg_uid_range);
2542 if (r == -EOPNOTSUPP)
2543 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.");
2544 if (r == -EBADE)
2545 return log_error_errno(r, "Upper 16 bits of root directory UID and GID do not match.");
2546 if (r < 0)
2547 return log_error_errno(r, "Failed to adjust UID/GID shift of OS tree: %m");
2548 if (r == 0)
2549 log_debug("Root directory of image is already owned by the right UID/GID range, skipping recursive chown operation.");
2550 else
2551 log_debug("Patched directory tree to match UID/GID range.");
2552
2553 return r;
2554 }
2555
2556 /*
2557 * Return values:
2558 * < 0 : wait_for_terminate() failed to get the state of the
2559 * container, the container was terminated by a signal, or
2560 * failed for an unknown reason. No change is made to the
2561 * container argument.
2562 * > 0 : The program executed in the container terminated with an
2563 * error. The exit code of the program executed in the
2564 * container is returned. The container argument has been set
2565 * to CONTAINER_TERMINATED.
2566 * 0 : The container is being rebooted, has been shut down or exited
2567 * successfully. The container argument has been set to either
2568 * CONTAINER_TERMINATED or CONTAINER_REBOOTED.
2569 *
2570 * That is, success is indicated by a return value of zero, and an
2571 * error is indicated by a non-zero value.
2572 */
2573 static int wait_for_container(pid_t pid, ContainerStatus *container) {
2574 siginfo_t status;
2575 int r;
2576
2577 r = wait_for_terminate(pid, &status);
2578 if (r < 0)
2579 return log_warning_errno(r, "Failed to wait for container: %m");
2580
2581 switch (status.si_code) {
2582
2583 case CLD_EXITED:
2584 if (status.si_status == 0)
2585 log_full(arg_quiet ? LOG_DEBUG : LOG_INFO, "Container %s exited successfully.", arg_machine);
2586 else
2587 log_full(arg_quiet ? LOG_DEBUG : LOG_INFO, "Container %s failed with error code %i.", arg_machine, status.si_status);
2588
2589 *container = CONTAINER_TERMINATED;
2590 return status.si_status;
2591
2592 case CLD_KILLED:
2593 if (status.si_status == SIGINT) {
2594 log_full(arg_quiet ? LOG_DEBUG : LOG_INFO, "Container %s has been shut down.", arg_machine);
2595 *container = CONTAINER_TERMINATED;
2596 return 0;
2597
2598 } else if (status.si_status == SIGHUP) {
2599 log_full(arg_quiet ? LOG_DEBUG : LOG_INFO, "Container %s is being rebooted.", arg_machine);
2600 *container = CONTAINER_REBOOTED;
2601 return 0;
2602 }
2603
2604 _fallthrough_;
2605 case CLD_DUMPED:
2606 return log_error_errno(SYNTHETIC_ERRNO(EIO),
2607 "Container %s terminated by signal %s.", arg_machine, signal_to_string(status.si_status));
2608
2609 default:
2610 return log_error_errno(SYNTHETIC_ERRNO(EIO),
2611 "Container %s failed due to unknown reason.", arg_machine);
2612 }
2613 }
2614
2615 static int on_orderly_shutdown(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) {
2616 pid_t pid;
2617
2618 pid = PTR_TO_PID(userdata);
2619 if (pid > 0) {
2620 if (kill(pid, arg_kill_signal) >= 0) {
2621 log_info("Trying to halt container. Send SIGTERM again to trigger immediate termination.");
2622 sd_event_source_set_userdata(s, NULL);
2623 return 0;
2624 }
2625 }
2626
2627 sd_event_exit(sd_event_source_get_event(s), 0);
2628 return 0;
2629 }
2630
2631 static int on_sigchld(sd_event_source *s, const struct signalfd_siginfo *ssi, void *userdata) {
2632 pid_t pid;
2633
2634 assert(s);
2635 assert(ssi);
2636
2637 pid = PTR_TO_PID(userdata);
2638
2639 for (;;) {
2640 siginfo_t si = {};
2641
2642 if (waitid(P_ALL, 0, &si, WNOHANG|WNOWAIT|WEXITED) < 0)
2643 return log_error_errno(errno, "Failed to waitid(): %m");
2644 if (si.si_pid == 0) /* No pending children. */
2645 break;
2646 if (si.si_pid == pid) {
2647 /* The main process we care for has exited. Return from
2648 * signal handler but leave the zombie. */
2649 sd_event_exit(sd_event_source_get_event(s), 0);
2650 break;
2651 }
2652
2653 /* Reap all other children. */
2654 (void) waitid(P_PID, si.si_pid, &si, WNOHANG|WEXITED);
2655 }
2656
2657 return 0;
2658 }
2659
2660 static int on_request_stop(sd_bus_message *m, void *userdata, sd_bus_error *error) {
2661 pid_t pid;
2662
2663 assert(m);
2664
2665 pid = PTR_TO_PID(userdata);
2666
2667 if (arg_kill_signal > 0) {
2668 log_info("Container termination requested. Attempting to halt container.");
2669 (void) kill(pid, arg_kill_signal);
2670 } else {
2671 log_info("Container termination requested. Exiting.");
2672 sd_event_exit(sd_bus_get_event(sd_bus_message_get_bus(m)), 0);
2673 }
2674
2675 return 0;
2676 }
2677
2678 static int determine_names(void) {
2679 int r;
2680
2681 if (arg_template && !arg_directory && arg_machine) {
2682
2683 /* If --template= was specified then we should not
2684 * search for a machine, but instead create a new one
2685 * in /var/lib/machine. */
2686
2687 arg_directory = path_join("/var/lib/machines", arg_machine);
2688 if (!arg_directory)
2689 return log_oom();
2690 }
2691
2692 if (!arg_image && !arg_directory) {
2693 if (arg_machine) {
2694 _cleanup_(image_unrefp) Image *i = NULL;
2695
2696 r = image_find(IMAGE_MACHINE, arg_machine, &i);
2697 if (r == -ENOENT)
2698 return log_error_errno(r, "No image for machine '%s'.", arg_machine);
2699 if (r < 0)
2700 return log_error_errno(r, "Failed to find image for machine '%s': %m", arg_machine);
2701
2702 if (IN_SET(i->type, IMAGE_RAW, IMAGE_BLOCK))
2703 r = free_and_strdup(&arg_image, i->path);
2704 else
2705 r = free_and_strdup(&arg_directory, i->path);
2706 if (r < 0)
2707 return log_oom();
2708
2709 if (!arg_ephemeral)
2710 arg_read_only = arg_read_only || i->read_only;
2711 } else {
2712 r = safe_getcwd(&arg_directory);
2713 if (r < 0)
2714 return log_error_errno(r, "Failed to determine current directory: %m");
2715 }
2716
2717 if (!arg_directory && !arg_image)
2718 return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to determine path, please use -D or -i.");
2719 }
2720
2721 if (!arg_machine) {
2722 if (arg_directory && path_equal(arg_directory, "/"))
2723 arg_machine = gethostname_malloc();
2724 else {
2725 if (arg_image) {
2726 char *e;
2727
2728 arg_machine = strdup(basename(arg_image));
2729
2730 /* Truncate suffix if there is one */
2731 e = endswith(arg_machine, ".raw");
2732 if (e)
2733 *e = 0;
2734 } else
2735 arg_machine = strdup(basename(arg_directory));
2736 }
2737 if (!arg_machine)
2738 return log_oom();
2739
2740 hostname_cleanup(arg_machine);
2741 if (!machine_name_is_valid(arg_machine))
2742 return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to determine machine name automatically, please use -M.");
2743
2744 if (arg_ephemeral) {
2745 char *b;
2746
2747 /* Add a random suffix when this is an
2748 * ephemeral machine, so that we can run many
2749 * instances at once without manually having
2750 * to specify -M each time. */
2751
2752 if (asprintf(&b, "%s-%016" PRIx64, arg_machine, random_u64()) < 0)
2753 return log_oom();
2754
2755 free(arg_machine);
2756 arg_machine = b;
2757 }
2758 }
2759
2760 return 0;
2761 }
2762
2763 static int chase_symlinks_and_update(char **p, unsigned flags) {
2764 char *chased;
2765 int r;
2766
2767 assert(p);
2768
2769 if (!*p)
2770 return 0;
2771
2772 r = chase_symlinks(*p, NULL, flags, &chased, NULL);
2773 if (r < 0)
2774 return log_error_errno(r, "Failed to resolve path %s: %m", *p);
2775
2776 return free_and_replace(*p, chased);
2777 }
2778
2779 static int determine_uid_shift(const char *directory) {
2780 int r;
2781
2782 if (arg_userns_mode == USER_NAMESPACE_NO) {
2783 arg_uid_shift = 0;
2784 return 0;
2785 }
2786
2787 if (arg_uid_shift == UID_INVALID) {
2788 struct stat st;
2789
2790 r = stat(directory, &st);
2791 if (r < 0)
2792 return log_error_errno(errno, "Failed to determine UID base of %s: %m", directory);
2793
2794 arg_uid_shift = st.st_uid & UINT32_C(0xffff0000);
2795
2796 if (arg_uid_shift != (st.st_gid & UINT32_C(0xffff0000)))
2797 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
2798 "UID and GID base of %s don't match.", directory);
2799
2800 arg_uid_range = UINT32_C(0x10000);
2801 }
2802
2803 if (arg_uid_shift > (uid_t) -1 - arg_uid_range)
2804 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
2805 "UID base too high for UID range.");
2806
2807 return 0;
2808 }
2809
2810 static unsigned long effective_clone_ns_flags(void) {
2811 unsigned long flags = arg_clone_ns_flags;
2812
2813 if (arg_private_network)
2814 flags |= CLONE_NEWNET;
2815 if (arg_use_cgns)
2816 flags |= CLONE_NEWCGROUP;
2817 if (arg_userns_mode != USER_NAMESPACE_NO)
2818 flags |= CLONE_NEWUSER;
2819
2820 return flags;
2821 }
2822
2823 static int patch_sysctl(void) {
2824
2825 /* This table is inspired by runc's sysctl() function */
2826 static const struct {
2827 const char *key;
2828 bool prefix;
2829 unsigned long clone_flags;
2830 } safe_sysctl[] = {
2831 { "kernel.hostname", false, CLONE_NEWUTS },
2832 { "kernel.domainname", false, CLONE_NEWUTS },
2833 { "kernel.msgmax", false, CLONE_NEWIPC },
2834 { "kernel.msgmnb", false, CLONE_NEWIPC },
2835 { "kernel.msgmni", false, CLONE_NEWIPC },
2836 { "kernel.sem", false, CLONE_NEWIPC },
2837 { "kernel.shmall", false, CLONE_NEWIPC },
2838 { "kernel.shmmax", false, CLONE_NEWIPC },
2839 { "kernel.shmmni", false, CLONE_NEWIPC },
2840 { "fs.mqueue.", true, CLONE_NEWIPC },
2841 { "net.", true, CLONE_NEWNET },
2842 };
2843
2844 unsigned long flags;
2845 char **k, **v;
2846 int r;
2847
2848 flags = effective_clone_ns_flags();
2849
2850 STRV_FOREACH_PAIR(k, v, arg_sysctl) {
2851 bool good = false;
2852 size_t i;
2853
2854 for (i = 0; i < ELEMENTSOF(safe_sysctl); i++) {
2855
2856 if (!FLAGS_SET(flags, safe_sysctl[i].clone_flags))
2857 continue;
2858
2859 if (safe_sysctl[i].prefix)
2860 good = startswith(*k, safe_sysctl[i].key);
2861 else
2862 good = streq(*k, safe_sysctl[i].key);
2863
2864 if (good)
2865 break;
2866 }
2867
2868 if (!good)
2869 return log_error_errno(SYNTHETIC_ERRNO(EPERM), "Refusing to write to sysctl '%s', as it is not safe in the selected namespaces.", *k);
2870
2871 r = sysctl_write(*k, *v);
2872 if (r < 0)
2873 return log_error_errno(r, "Failed to write sysctl '%s': %m", *k);
2874 }
2875
2876 return 0;
2877 }
2878
2879 static int inner_child(
2880 Barrier *barrier,
2881 const char *directory,
2882 bool secondary,
2883 int kmsg_socket,
2884 int rtnl_socket,
2885 int master_pty_socket,
2886 FDSet *fds) {
2887
2888 _cleanup_free_ char *home = NULL;
2889 char as_uuid[ID128_UUID_STRING_MAX];
2890 size_t n_env = 1;
2891 const char *envp[] = {
2892 "PATH=" DEFAULT_PATH_COMPAT,
2893 NULL, /* container */
2894 NULL, /* TERM */
2895 NULL, /* HOME */
2896 NULL, /* USER */
2897 NULL, /* LOGNAME */
2898 NULL, /* container_uuid */
2899 NULL, /* LISTEN_FDS */
2900 NULL, /* LISTEN_PID */
2901 NULL, /* NOTIFY_SOCKET */
2902 NULL
2903 };
2904 const char *exec_target;
2905 _cleanup_strv_free_ char **env_use = NULL;
2906 int r, which_failed;
2907
2908 /* This is the "inner" child process, i.e. the one forked off by the "outer" child process, which is the one
2909 * the container manager itself forked off. At the time of clone() it gained its own CLONE_NEWNS, CLONE_NEWPID,
2910 * CLONE_NEWUTS, CLONE_NEWIPC, CLONE_NEWUSER namespaces. Note that it has its own CLONE_NEWNS namespace,
2911 * separate from the CLONE_NEWNS created for the "outer" child, and also separate from the host's CLONE_NEWNS
2912 * namespace. The reason for having two levels of CLONE_NEWNS namespaces is that the "inner" one is owned by
2913 * the CLONE_NEWUSER namespace of the container, while the "outer" one is owned by the host's CLONE_NEWUSER
2914 * namespace.
2915 *
2916 * Note at this point we have no CLONE_NEWNET namespace yet. We'll acquire that one later through
2917 * unshare(). See below. */
2918
2919 assert(barrier);
2920 assert(directory);
2921 assert(kmsg_socket >= 0);
2922
2923 log_debug("Inner child is initializing.");
2924
2925 if (arg_userns_mode != USER_NAMESPACE_NO) {
2926 /* Tell the parent, that it now can write the UID map. */
2927 (void) barrier_place(barrier); /* #1 */
2928
2929 /* Wait until the parent wrote the UID map */
2930 if (!barrier_place_and_sync(barrier)) /* #2 */
2931 return log_error_errno(SYNTHETIC_ERRNO(ESRCH),
2932 "Parent died too early");
2933 }
2934
2935 r = reset_uid_gid();
2936 if (r < 0)
2937 return log_error_errno(r, "Couldn't become new root: %m");
2938
2939 r = mount_all(NULL,
2940 arg_mount_settings | MOUNT_IN_USERNS,
2941 arg_uid_shift,
2942 arg_selinux_apifs_context);
2943 if (r < 0)
2944 return r;
2945
2946 if (!arg_network_namespace_path && arg_private_network) {
2947 r = unshare(CLONE_NEWNET);
2948 if (r < 0)
2949 return log_error_errno(errno, "Failed to unshare network namespace: %m");
2950
2951 /* Tell the parent that it can setup network interfaces. */
2952 (void) barrier_place(barrier); /* #3 */
2953 }
2954
2955 r = mount_sysfs(NULL, arg_mount_settings);
2956 if (r < 0)
2957 return r;
2958
2959 /* Wait until we are cgroup-ified, so that we
2960 * can mount the right cgroup path writable */
2961 if (!barrier_place_and_sync(barrier)) /* #4 */
2962 return log_error_errno(SYNTHETIC_ERRNO(ESRCH),
2963 "Parent died too early");
2964
2965 if (arg_use_cgns) {
2966 r = unshare(CLONE_NEWCGROUP);
2967 if (r < 0)
2968 return log_error_errno(errno, "Failed to unshare cgroup namespace: %m");
2969 r = mount_cgroups(
2970 "",
2971 arg_unified_cgroup_hierarchy,
2972 arg_userns_mode != USER_NAMESPACE_NO,
2973 arg_uid_shift,
2974 arg_uid_range,
2975 arg_selinux_apifs_context,
2976 true);
2977 } else
2978 r = mount_systemd_cgroup_writable("", arg_unified_cgroup_hierarchy);
2979 if (r < 0)
2980 return r;
2981
2982 r = setup_boot_id();
2983 if (r < 0)
2984 return r;
2985
2986 r = setup_kmsg(kmsg_socket);
2987 if (r < 0)
2988 return r;
2989 kmsg_socket = safe_close(kmsg_socket);
2990
2991 r = mount_custom(
2992 "/",
2993 arg_custom_mounts,
2994 arg_n_custom_mounts,
2995 0,
2996 arg_selinux_apifs_context,
2997 MOUNT_NON_ROOT_ONLY | MOUNT_IN_USERNS);
2998 if (r < 0)
2999 return r;
3000
3001 if (setsid() < 0)
3002 return log_error_errno(errno, "setsid() failed: %m");
3003
3004 if (arg_private_network)
3005 (void) loopback_setup();
3006
3007 if (arg_expose_ports) {
3008 r = expose_port_send_rtnl(rtnl_socket);
3009 if (r < 0)
3010 return r;
3011 rtnl_socket = safe_close(rtnl_socket);
3012 }
3013
3014 if (arg_console_mode != CONSOLE_PIPE) {
3015 _cleanup_close_ int master = -1;
3016 _cleanup_free_ char *console = NULL;
3017
3018 /* Allocate a pty and make it available as /dev/console. */
3019 master = openpt_allocate(O_RDWR|O_NONBLOCK, &console);
3020 if (master < 0)
3021 return log_error_errno(master, "Failed to allocate a pty: %m");
3022
3023 r = setup_dev_console(console);
3024 if (r < 0)
3025 return log_error_errno(r, "Failed to set up /dev/console: %m");
3026
3027 r = send_one_fd(master_pty_socket, master, 0);
3028 if (r < 0)
3029 return log_error_errno(r, "Failed to send master fd: %m");
3030 master_pty_socket = safe_close(master_pty_socket);
3031
3032 r = setup_stdio_as_dev_console();
3033 if (r < 0)
3034 return r;
3035 }
3036
3037 r = patch_sysctl();
3038 if (r < 0)
3039 return r;
3040
3041 if (arg_oom_score_adjust_set) {
3042 r = set_oom_score_adjust(arg_oom_score_adjust);
3043 if (r < 0)
3044 return log_error_errno(r, "Failed to adjust OOM score: %m");
3045 }
3046
3047 if (arg_cpu_set.set)
3048 if (sched_setaffinity(0, arg_cpu_set.allocated, arg_cpu_set.set) < 0)
3049 return log_error_errno(errno, "Failed to set CPU affinity: %m");
3050
3051 (void) setup_hostname();
3052
3053 if (arg_personality != PERSONALITY_INVALID) {
3054 r = safe_personality(arg_personality);
3055 if (r < 0)
3056 return log_error_errno(r, "personality() failed: %m");
3057 } else if (secondary) {
3058 r = safe_personality(PER_LINUX32);
3059 if (r < 0)
3060 return log_error_errno(r, "personality() failed: %m");
3061 }
3062
3063 r = setrlimit_closest_all((const struct rlimit *const*) arg_rlimit, &which_failed);
3064 if (r < 0)
3065 return log_error_errno(r, "Failed to apply resource limit RLIMIT_%s: %m", rlimit_to_string(which_failed));
3066
3067 #if HAVE_SECCOMP
3068 if (arg_seccomp) {
3069
3070 if (is_seccomp_available()) {
3071
3072 r = seccomp_load(arg_seccomp);
3073 if (ERRNO_IS_SECCOMP_FATAL(r))
3074 return log_error_errno(r, "Failed to install seccomp filter: %m");
3075 if (r < 0)
3076 log_debug_errno(r, "Failed to install seccomp filter: %m");
3077 }
3078 } else
3079 #endif
3080 {
3081 r = setup_seccomp(arg_caps_retain, arg_syscall_whitelist, arg_syscall_blacklist);
3082 if (r < 0)
3083 return r;
3084 }
3085
3086 #if HAVE_SELINUX
3087 if (arg_selinux_context)
3088 if (setexeccon(arg_selinux_context) < 0)
3089 return log_error_errno(errno, "setexeccon(\"%s\") failed: %m", arg_selinux_context);
3090 #endif
3091
3092 /* Make sure we keep the caps across the uid/gid dropping, so that we can retain some selected caps
3093 * if we need to later on. */
3094 if (prctl(PR_SET_KEEPCAPS, 1) < 0)
3095 return log_error_errno(errno, "Failed to set PR_SET_KEEPCAPS: %m");
3096
3097 if (uid_is_valid(arg_uid) || gid_is_valid(arg_gid))
3098 r = change_uid_gid_raw(arg_uid, arg_gid, arg_supplementary_gids, arg_n_supplementary_gids);
3099 else
3100 r = change_uid_gid(arg_user, &home);
3101 if (r < 0)
3102 return r;
3103
3104 r = drop_capabilities(getuid());
3105 if (r < 0)
3106 return log_error_errno(r, "Dropping capabilities failed: %m");
3107
3108 if (arg_no_new_privileges)
3109 if (prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0) < 0)
3110 return log_error_errno(errno, "Failed to disable new privileges: %m");
3111
3112 /* LXC sets container=lxc, so follow the scheme here */
3113 envp[n_env++] = strjoina("container=", arg_container_service_name);
3114
3115 envp[n_env] = strv_find_prefix(environ, "TERM=");
3116 if (envp[n_env])
3117 n_env++;
3118
3119 if (home || !uid_is_valid(arg_uid) || arg_uid == 0)
3120 if (asprintf((char**)(envp + n_env++), "HOME=%s", home ?: "/root") < 0)
3121 return log_oom();
3122
3123 if (arg_user || !uid_is_valid(arg_uid) || arg_uid == 0)
3124 if (asprintf((char**)(envp + n_env++), "USER=%s", arg_user ?: "root") < 0 ||
3125 asprintf((char**)(envp + n_env++), "LOGNAME=%s", arg_user ? arg_user : "root") < 0)
3126 return log_oom();
3127
3128 assert(!sd_id128_is_null(arg_uuid));
3129
3130 if (asprintf((char**)(envp + n_env++), "container_uuid=%s", id128_to_uuid_string(arg_uuid, as_uuid)) < 0)
3131 return log_oom();
3132
3133 if (fdset_size(fds) > 0) {
3134 r = fdset_cloexec(fds, false);
3135 if (r < 0)
3136 return log_error_errno(r, "Failed to unset O_CLOEXEC for file descriptors.");
3137
3138 if ((asprintf((char **)(envp + n_env++), "LISTEN_FDS=%u", fdset_size(fds)) < 0) ||
3139 (asprintf((char **)(envp + n_env++), "LISTEN_PID=1") < 0))
3140 return log_oom();
3141 }
3142 if (asprintf((char **)(envp + n_env++), "NOTIFY_SOCKET=%s", NSPAWN_NOTIFY_SOCKET_PATH) < 0)
3143 return log_oom();
3144
3145 env_use = strv_env_merge(2, envp, arg_setenv);
3146 if (!env_use)
3147 return log_oom();
3148
3149 /* Let the parent know that we are ready and
3150 * wait until the parent is ready with the
3151 * setup, too... */
3152 if (!barrier_place_and_sync(barrier)) /* #5 */
3153 return log_error_errno(SYNTHETIC_ERRNO(ESRCH),
3154 "Parent died too early");
3155
3156 if (arg_chdir)
3157 if (chdir(arg_chdir) < 0)
3158 return log_error_errno(errno, "Failed to change to specified working directory %s: %m", arg_chdir);
3159
3160 if (arg_start_mode == START_PID2) {
3161 r = stub_pid1(arg_uuid);
3162 if (r < 0)
3163 return r;
3164 }
3165
3166 log_debug("Inner child completed, invoking payload.");
3167
3168 /* Now, explicitly close the log, so that we then can close all remaining fds. Closing the log explicitly first
3169 * has the benefit that the logging subsystem knows about it, and is thus ready to be reopened should we need
3170 * it again. Note that the other fds closed here are at least the locking and barrier fds. */
3171 log_close();
3172 log_set_open_when_needed(true);
3173
3174 (void) fdset_close_others(fds);
3175
3176 if (arg_start_mode == START_BOOT) {
3177 char **a;
3178 size_t m;
3179
3180 /* Automatically search for the init system */
3181
3182 m = strv_length(arg_parameters);
3183 a = newa(char*, m + 2);
3184 memcpy_safe(a + 1, arg_parameters, m * sizeof(char*));
3185 a[1 + m] = NULL;
3186
3187 a[0] = (char*) "/usr/lib/systemd/systemd";
3188 execve(a[0], a, env_use);
3189
3190 a[0] = (char*) "/lib/systemd/systemd";
3191 execve(a[0], a, env_use);
3192
3193 a[0] = (char*) "/sbin/init";
3194 execve(a[0], a, env_use);
3195
3196 exec_target = "/usr/lib/systemd/systemd, /lib/systemd/systemd, /sbin/init";
3197 } else if (!strv_isempty(arg_parameters)) {
3198 const char *dollar_path;
3199
3200 exec_target = arg_parameters[0];
3201
3202 /* Use the user supplied search $PATH if there is one, or DEFAULT_PATH_COMPAT if not to search the
3203 * binary. */
3204 dollar_path = strv_env_get(env_use, "PATH");
3205 if (dollar_path) {
3206 if (putenv((char*) dollar_path) != 0)
3207 return log_error_errno(errno, "Failed to update $PATH: %m");
3208 }
3209
3210 execvpe(arg_parameters[0], arg_parameters, env_use);
3211 } else {
3212 if (!arg_chdir)
3213 /* If we cannot change the directory, we'll end up in /, that is expected. */
3214 (void) chdir(home ?: "/root");
3215
3216 execle("/bin/bash", "-bash", NULL, env_use);
3217 execle("/bin/sh", "-sh", NULL, env_use);
3218
3219 exec_target = "/bin/bash, /bin/sh";
3220 }
3221
3222 return log_error_errno(errno, "execv(%s) failed: %m", exec_target);
3223 }
3224
3225 static int setup_sd_notify_child(void) {
3226 _cleanup_close_ int fd = -1;
3227 union sockaddr_union sa = {
3228 .un.sun_family = AF_UNIX,
3229 .un.sun_path = NSPAWN_NOTIFY_SOCKET_PATH,
3230 };
3231 int r;
3232
3233 fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
3234 if (fd < 0)
3235 return log_error_errno(errno, "Failed to allocate notification socket: %m");
3236
3237 (void) mkdir_parents(NSPAWN_NOTIFY_SOCKET_PATH, 0755);
3238 (void) sockaddr_un_unlink(&sa.un);
3239
3240 r = bind(fd, &sa.sa, SOCKADDR_UN_LEN(sa.un));
3241 if (r < 0)
3242 return log_error_errno(errno, "bind(" NSPAWN_NOTIFY_SOCKET_PATH ") failed: %m");
3243
3244 r = userns_lchown(NSPAWN_NOTIFY_SOCKET_PATH, 0, 0);
3245 if (r < 0)
3246 return log_error_errno(r, "Failed to chown " NSPAWN_NOTIFY_SOCKET_PATH ": %m");
3247
3248 r = setsockopt_int(fd, SOL_SOCKET, SO_PASSCRED, true);
3249 if (r < 0)
3250 return log_error_errno(r, "SO_PASSCRED failed: %m");
3251
3252 return TAKE_FD(fd);
3253 }
3254
3255 static int outer_child(
3256 Barrier *barrier,
3257 const char *directory,
3258 DissectedImage *dissected_image,
3259 bool secondary,
3260 int pid_socket,
3261 int uuid_socket,
3262 int notify_socket,
3263 int kmsg_socket,
3264 int rtnl_socket,
3265 int uid_shift_socket,
3266 int master_pty_socket,
3267 int unified_cgroup_hierarchy_socket,
3268 FDSet *fds,
3269 int netns_fd) {
3270
3271 _cleanup_close_ int fd = -1;
3272 const char *p;
3273 pid_t pid;
3274 ssize_t l;
3275 int r;
3276
3277 /* This is the "outer" child process, i.e the one forked off by the container manager itself. It already has
3278 * its own CLONE_NEWNS namespace (which was created by the clone()). It still lives in the host's CLONE_NEWPID,
3279 * CLONE_NEWUTS, CLONE_NEWIPC, CLONE_NEWUSER and CLONE_NEWNET namespaces. After it completed a number of
3280 * initializations a second child (the "inner" one) is forked off it, and it exits. */
3281
3282 assert(barrier);
3283 assert(directory);
3284 assert(pid_socket >= 0);
3285 assert(uuid_socket >= 0);
3286 assert(notify_socket >= 0);
3287 assert(master_pty_socket >= 0);
3288 assert(kmsg_socket >= 0);
3289
3290 log_debug("Outer child is initializing.");
3291
3292 if (prctl(PR_SET_PDEATHSIG, SIGKILL) < 0)
3293 return log_error_errno(errno, "PR_SET_PDEATHSIG failed: %m");
3294
3295 r = reset_audit_loginuid();
3296 if (r < 0)
3297 return r;
3298
3299 /* Mark everything as slave, so that we still
3300 * receive mounts from the real root, but don't
3301 * propagate mounts to the real root. */
3302 r = mount_verbose(LOG_ERR, NULL, "/", NULL, MS_SLAVE|MS_REC, NULL);
3303 if (r < 0)
3304 return r;
3305
3306 if (dissected_image) {
3307 /* If we are operating on a disk image, then mount its root directory now, but leave out the rest. We
3308 * can read the UID shift from it if we need to. Further down we'll mount the rest, but then with the
3309 * uid shift known. That way we can mount VFAT file systems shifted to the right place right away. This
3310 * makes sure ESP partitions and userns are compatible. */
3311
3312 r = dissected_image_mount(dissected_image, directory, arg_uid_shift,
3313 DISSECT_IMAGE_MOUNT_ROOT_ONLY|DISSECT_IMAGE_DISCARD_ON_LOOP|
3314 (arg_read_only ? DISSECT_IMAGE_READ_ONLY : DISSECT_IMAGE_FSCK)|
3315 (arg_start_mode == START_BOOT ? DISSECT_IMAGE_VALIDATE_OS : 0));
3316 if (r == -EUCLEAN)
3317 return log_error_errno(r, "File system check for image failed: %m");
3318 if (r < 0)
3319 return log_error_errno(r, "Failed to mount image root file system: %m");
3320 }
3321
3322 r = determine_uid_shift(directory);
3323 if (r < 0)
3324 return r;
3325
3326 if (arg_userns_mode != USER_NAMESPACE_NO) {
3327 /* Let the parent know which UID shift we read from the image */
3328 l = send(uid_shift_socket, &arg_uid_shift, sizeof(arg_uid_shift), MSG_NOSIGNAL);
3329 if (l < 0)
3330 return log_error_errno(errno, "Failed to send UID shift: %m");
3331 if (l != sizeof(arg_uid_shift))
3332 return log_error_errno(SYNTHETIC_ERRNO(EIO),
3333 "Short write while sending UID shift.");
3334
3335 if (arg_userns_mode == USER_NAMESPACE_PICK) {
3336 /* When we are supposed to pick the UID shift, the parent will check now whether the UID shift
3337 * we just read from the image is available. If yes, it will send the UID shift back to us, if
3338 * not it will pick a different one, and send it back to us. */
3339
3340 l = recv(uid_shift_socket, &arg_uid_shift, sizeof(arg_uid_shift), 0);
3341 if (l < 0)
3342 return log_error_errno(errno, "Failed to recv UID shift: %m");
3343 if (l != sizeof(arg_uid_shift))
3344 return log_error_errno(SYNTHETIC_ERRNO(EIO),
3345 "Short read while receiving UID shift.");
3346 }
3347
3348 log_full(arg_quiet ? LOG_DEBUG : LOG_INFO,
3349 "Selected user namespace base " UID_FMT " and range " UID_FMT ".", arg_uid_shift, arg_uid_range);
3350 }
3351
3352 if (path_equal(directory, "/")) {
3353 /* If the directory we shall boot is the host, let's operate on a bind mount at a different
3354 * place, so that we can make changes to its mount structure (for example, to implement
3355 * --volatile=) without this interfering with our ability to access files such as
3356 * /etc/localtime to copy into the container. Note that we use a fixed place for this
3357 * (instead of a temporary directory, since we are living in our own mount namspace here
3358 * already, and thus don't need to be afraid of colliding with anyone else's mounts).*/
3359 (void) mkdir_p("/run/systemd/nspawn-root", 0755);
3360
3361 r = mount_verbose(LOG_ERR, "/", "/run/systemd/nspawn-root", NULL, MS_BIND|MS_REC, NULL);
3362 if (r < 0)
3363 return r;
3364
3365 directory = "/run/systemd/nspawn-root";
3366 }
3367
3368 r = setup_pivot_root(
3369 directory,
3370 arg_pivot_root_new,
3371 arg_pivot_root_old);
3372 if (r < 0)
3373 return r;
3374
3375 r = setup_volatile_mode(
3376 directory,
3377 arg_volatile_mode,
3378 arg_uid_shift,
3379 arg_selinux_apifs_context);
3380 if (r < 0)
3381 return r;
3382
3383 r = mount_custom(
3384 directory,
3385 arg_custom_mounts,
3386 arg_n_custom_mounts,
3387 arg_uid_shift,
3388 arg_selinux_apifs_context,
3389 MOUNT_ROOT_ONLY);
3390 if (r < 0)
3391 return r;
3392
3393 /* Make sure we always have a mount that we can move to root later on. */
3394 if (!path_is_mount_point(directory, NULL, 0)) {
3395 r = mount_verbose(LOG_ERR, directory, directory, NULL, MS_BIND|MS_REC, NULL);
3396 if (r < 0)
3397 return r;
3398 }
3399
3400 if (dissected_image) {
3401 /* Now we know the uid shift, let's now mount everything else that might be in the image. */
3402 r = dissected_image_mount(dissected_image, directory, arg_uid_shift,
3403 DISSECT_IMAGE_MOUNT_NON_ROOT_ONLY|DISSECT_IMAGE_DISCARD_ON_LOOP|(arg_read_only ? DISSECT_IMAGE_READ_ONLY : DISSECT_IMAGE_FSCK));
3404 if (r == -EUCLEAN)
3405 return log_error_errno(r, "File system check for image failed: %m");
3406 if (r < 0)
3407 return log_error_errno(r, "Failed to mount image file system: %m");
3408 }
3409
3410 if (arg_unified_cgroup_hierarchy == CGROUP_UNIFIED_UNKNOWN) {
3411 /* OK, we don't know yet which cgroup mode to use yet. Let's figure it out, and tell the parent. */
3412
3413 r = detect_unified_cgroup_hierarchy_from_image(directory);
3414 if (r < 0)
3415 return r;
3416
3417 l = send(unified_cgroup_hierarchy_socket, &arg_unified_cgroup_hierarchy, sizeof(arg_unified_cgroup_hierarchy), MSG_NOSIGNAL);
3418 if (l < 0)
3419 return log_error_errno(errno, "Failed to send cgroup mode: %m");
3420 if (l != sizeof(arg_unified_cgroup_hierarchy))
3421 return log_error_errno(SYNTHETIC_ERRNO(EIO),
3422 "Short write while sending cgroup mode.");
3423
3424 unified_cgroup_hierarchy_socket = safe_close(unified_cgroup_hierarchy_socket);
3425 }
3426
3427 /* Mark everything as shared so our mounts get propagated down. This is
3428 * required to make new bind mounts available in systemd services
3429 * inside the container that create a new mount namespace.
3430 * See https://github.com/systemd/systemd/issues/3860
3431 * Further submounts (such as /dev) done after this will inherit the
3432 * shared propagation mode.
3433 *
3434 * IMPORTANT: Do not overmount the root directory anymore from now on to
3435 * enable moving the root directory mount to root later on.
3436 * https://github.com/systemd/systemd/issues/3847#issuecomment-562735251
3437 */
3438 r = mount_verbose(LOG_ERR, NULL, directory, NULL, MS_SHARED|MS_REC, NULL);
3439 if (r < 0)
3440 return r;
3441
3442 r = recursive_chown(directory, arg_uid_shift, arg_uid_range);
3443 if (r < 0)
3444 return r;
3445
3446 r = base_filesystem_create(directory, arg_uid_shift, (gid_t) arg_uid_shift);
3447 if (r < 0)
3448 return r;
3449
3450 if (arg_read_only && arg_volatile_mode == VOLATILE_NO &&
3451 !has_custom_root_mount(arg_custom_mounts, arg_n_custom_mounts)) {
3452 r = bind_remount_recursive(directory, MS_RDONLY, MS_RDONLY, NULL);
3453 if (r < 0)
3454 return log_error_errno(r, "Failed to make tree read-only: %m");
3455 }
3456
3457 r = mount_all(directory,
3458 arg_mount_settings,
3459 arg_uid_shift,
3460 arg_selinux_apifs_context);
3461 if (r < 0)
3462 return r;
3463
3464 r = copy_devnodes(directory);
3465 if (r < 0)
3466 return r;
3467
3468 r = make_extra_nodes(directory);
3469 if (r < 0)
3470 return r;
3471
3472 (void) dev_setup(directory, arg_uid_shift, arg_uid_shift);
3473
3474 p = prefix_roota(directory, "/run/systemd");
3475 (void) make_inaccessible_nodes(p, arg_uid_shift, arg_uid_shift);
3476
3477 r = setup_pts(directory);
3478 if (r < 0)
3479 return r;
3480
3481 r = setup_propagate(directory);
3482 if (r < 0)
3483 return r;
3484
3485 r = setup_keyring();
3486 if (r < 0)
3487 return r;
3488
3489 r = mount_custom(
3490 directory,
3491 arg_custom_mounts,
3492 arg_n_custom_mounts,
3493 arg_uid_shift,
3494 arg_selinux_apifs_context,
3495 MOUNT_NON_ROOT_ONLY);
3496 if (r < 0)
3497 return r;
3498
3499 r = setup_timezone(directory);
3500 if (r < 0)
3501 return r;
3502
3503 r = setup_resolv_conf(directory);
3504 if (r < 0)
3505 return r;
3506
3507 r = setup_machine_id(directory);
3508 if (r < 0)
3509 return r;
3510
3511 r = setup_journal(directory);
3512 if (r < 0)
3513 return r;
3514
3515 if (!arg_use_cgns) {
3516 r = mount_cgroups(
3517 directory,
3518 arg_unified_cgroup_hierarchy,
3519 arg_userns_mode != USER_NAMESPACE_NO,
3520 arg_uid_shift,
3521 arg_uid_range,
3522 arg_selinux_apifs_context,
3523 false);
3524 if (r < 0)
3525 return r;
3526 }
3527
3528 r = mount_move_root(directory);
3529 if (r < 0)
3530 return log_error_errno(r, "Failed to move root directory: %m");
3531
3532 fd = setup_sd_notify_child();
3533 if (fd < 0)
3534 return fd;
3535
3536 pid = raw_clone(SIGCHLD|CLONE_NEWNS|
3537 arg_clone_ns_flags |
3538 (arg_userns_mode != USER_NAMESPACE_NO ? CLONE_NEWUSER : 0));
3539 if (pid < 0)
3540 return log_error_errno(errno, "Failed to fork inner child: %m");
3541 if (pid == 0) {
3542 pid_socket = safe_close(pid_socket);
3543 uuid_socket = safe_close(uuid_socket);
3544 notify_socket = safe_close(notify_socket);
3545 uid_shift_socket = safe_close(uid_shift_socket);
3546
3547 /* The inner child has all namespaces that are
3548 * requested, so that we all are owned by the user if
3549 * user namespaces are turned on. */
3550
3551 if (arg_network_namespace_path) {
3552 r = namespace_enter(-1, -1, netns_fd, -1, -1);
3553 if (r < 0)
3554 return log_error_errno(r, "Failed to join network namespace: %m");
3555 }
3556
3557 r = inner_child(barrier, directory, secondary, kmsg_socket, rtnl_socket, master_pty_socket, fds);
3558 if (r < 0)
3559 _exit(EXIT_FAILURE);
3560
3561 _exit(EXIT_SUCCESS);
3562 }
3563
3564 l = send(pid_socket, &pid, sizeof(pid), MSG_NOSIGNAL);
3565 if (l < 0)
3566 return log_error_errno(errno, "Failed to send PID: %m");
3567 if (l != sizeof(pid))
3568 return log_error_errno(SYNTHETIC_ERRNO(EIO),
3569 "Short write while sending PID.");
3570
3571 l = send(uuid_socket, &arg_uuid, sizeof(arg_uuid), MSG_NOSIGNAL);
3572 if (l < 0)
3573 return log_error_errno(errno, "Failed to send machine ID: %m");
3574 if (l != sizeof(arg_uuid))
3575 return log_error_errno(SYNTHETIC_ERRNO(EIO),
3576 "Short write while sending machine ID.");
3577
3578 l = send_one_fd(notify_socket, fd, 0);
3579 if (l < 0)
3580 return log_error_errno(l, "Failed to send notify fd: %m");
3581
3582 pid_socket = safe_close(pid_socket);
3583 uuid_socket = safe_close(uuid_socket);
3584 notify_socket = safe_close(notify_socket);
3585 master_pty_socket = safe_close(master_pty_socket);
3586 kmsg_socket = safe_close(kmsg_socket);
3587 rtnl_socket = safe_close(rtnl_socket);
3588 netns_fd = safe_close(netns_fd);
3589
3590 return 0;
3591 }
3592
3593 static int uid_shift_pick(uid_t *shift, LockFile *ret_lock_file) {
3594 bool tried_hashed = false;
3595 unsigned n_tries = 100;
3596 uid_t candidate;
3597 int r;
3598
3599 assert(shift);
3600 assert(ret_lock_file);
3601 assert(arg_userns_mode == USER_NAMESPACE_PICK);
3602 assert(arg_uid_range == 0x10000U);
3603
3604 candidate = *shift;
3605
3606 (void) mkdir("/run/systemd/nspawn-uid", 0755);
3607
3608 for (;;) {
3609 char lock_path[STRLEN("/run/systemd/nspawn-uid/") + DECIMAL_STR_MAX(uid_t) + 1];
3610 _cleanup_(release_lock_file) LockFile lf = LOCK_FILE_INIT;
3611
3612 if (--n_tries <= 0)
3613 return -EBUSY;
3614
3615 if (candidate < CONTAINER_UID_BASE_MIN || candidate > CONTAINER_UID_BASE_MAX)
3616 goto next;
3617 if ((candidate & UINT32_C(0xFFFF)) != 0)
3618 goto next;
3619
3620 xsprintf(lock_path, "/run/systemd/nspawn-uid/" UID_FMT, candidate);
3621 r = make_lock_file(lock_path, LOCK_EX|LOCK_NB, &lf);
3622 if (r == -EBUSY) /* Range already taken by another nspawn instance */
3623 goto next;
3624 if (r < 0)
3625 return r;
3626
3627 /* Make some superficial checks whether the range is currently known in the user database */
3628 if (getpwuid(candidate))
3629 goto next;
3630 if (getpwuid(candidate + UINT32_C(0xFFFE)))
3631 goto next;
3632 if (getgrgid(candidate))
3633 goto next;
3634 if (getgrgid(candidate + UINT32_C(0xFFFE)))
3635 goto next;
3636
3637 *ret_lock_file = lf;
3638 lf = (struct LockFile) LOCK_FILE_INIT;
3639 *shift = candidate;
3640 return 0;
3641
3642 next:
3643 if (arg_machine && !tried_hashed) {
3644 /* Try to hash the base from the container name */
3645
3646 static const uint8_t hash_key[] = {
3647 0xe1, 0x56, 0xe0, 0xf0, 0x4a, 0xf0, 0x41, 0xaf,
3648 0x96, 0x41, 0xcf, 0x41, 0x33, 0x94, 0xff, 0x72
3649 };
3650
3651 candidate = (uid_t) siphash24(arg_machine, strlen(arg_machine), hash_key);
3652
3653 tried_hashed = true;
3654 } else
3655 random_bytes(&candidate, sizeof(candidate));
3656
3657 candidate = (candidate % (CONTAINER_UID_BASE_MAX - CONTAINER_UID_BASE_MIN)) + CONTAINER_UID_BASE_MIN;
3658 candidate &= (uid_t) UINT32_C(0xFFFF0000);
3659 }
3660 }
3661
3662 static int setup_uid_map(pid_t pid) {
3663 char uid_map[STRLEN("/proc//uid_map") + DECIMAL_STR_MAX(uid_t) + 1], line[DECIMAL_STR_MAX(uid_t)*3+3+1];
3664 int r;
3665
3666 assert(pid > 1);
3667
3668 xsprintf(uid_map, "/proc/" PID_FMT "/uid_map", pid);
3669 xsprintf(line, UID_FMT " " UID_FMT " " UID_FMT "\n", 0, arg_uid_shift, arg_uid_range);
3670 r = write_string_file(uid_map, line, WRITE_STRING_FILE_DISABLE_BUFFER);
3671 if (r < 0)
3672 return log_error_errno(r, "Failed to write UID map: %m");
3673
3674 /* We always assign the same UID and GID ranges */
3675 xsprintf(uid_map, "/proc/" PID_FMT "/gid_map", pid);
3676 r = write_string_file(uid_map, line, WRITE_STRING_FILE_DISABLE_BUFFER);
3677 if (r < 0)
3678 return log_error_errno(r, "Failed to write GID map: %m");
3679
3680 return 0;
3681 }
3682
3683 static int nspawn_dispatch_notify_fd(sd_event_source *source, int fd, uint32_t revents, void *userdata) {
3684 char buf[NOTIFY_BUFFER_MAX+1];
3685 char *p = NULL;
3686 struct iovec iovec = {
3687 .iov_base = buf,
3688 .iov_len = sizeof(buf)-1,
3689 };
3690 CMSG_BUFFER_TYPE(CMSG_SPACE(sizeof(struct ucred)) +
3691 CMSG_SPACE(sizeof(int) * NOTIFY_FD_MAX)) control;
3692 struct msghdr msghdr = {
3693 .msg_iov = &iovec,
3694 .msg_iovlen = 1,
3695 .msg_control = &control,
3696 .msg_controllen = sizeof(control),
3697 };
3698 struct ucred *ucred;
3699 ssize_t n;
3700 pid_t inner_child_pid;
3701 _cleanup_strv_free_ char **tags = NULL;
3702
3703 assert(userdata);
3704
3705 inner_child_pid = PTR_TO_PID(userdata);
3706
3707 if (revents != EPOLLIN) {
3708 log_warning("Got unexpected poll event for notify fd.");
3709 return 0;
3710 }
3711
3712 n = recvmsg_safe(fd, &msghdr, MSG_DONTWAIT|MSG_CMSG_CLOEXEC);
3713 if (IN_SET(n, -EAGAIN, -EINTR))
3714 return 0;
3715 if (n < 0)
3716 return log_warning_errno(n, "Couldn't read notification socket: %m");
3717
3718 cmsg_close_all(&msghdr);
3719
3720 ucred = CMSG_FIND_DATA(&msghdr, SOL_SOCKET, SCM_CREDENTIALS, struct ucred);
3721 if (!ucred || ucred->pid != inner_child_pid) {
3722 log_debug("Received notify message without valid credentials. Ignoring.");
3723 return 0;
3724 }
3725
3726 if ((size_t) n >= sizeof(buf)) {
3727 log_warning("Received notify message exceeded maximum size. Ignoring.");
3728 return 0;
3729 }
3730
3731 buf[n] = 0;
3732 tags = strv_split(buf, "\n\r");
3733 if (!tags)
3734 return log_oom();
3735
3736 if (strv_find(tags, "READY=1"))
3737 (void) sd_notifyf(false, "READY=1\n");
3738
3739 p = strv_find_startswith(tags, "STATUS=");
3740 if (p)
3741 (void) sd_notifyf(false, "STATUS=Container running: %s", p);
3742
3743 return 0;
3744 }
3745
3746 static int setup_sd_notify_parent(sd_event *event, int fd, pid_t *inner_child_pid, sd_event_source **notify_event_source) {
3747 int r;
3748
3749 r = sd_event_add_io(event, notify_event_source, fd, EPOLLIN, nspawn_dispatch_notify_fd, inner_child_pid);
3750 if (r < 0)
3751 return log_error_errno(r, "Failed to allocate notify event source: %m");
3752
3753 (void) sd_event_source_set_description(*notify_event_source, "nspawn-notify");
3754
3755 return 0;
3756 }
3757
3758 static int merge_settings(Settings *settings, const char *path) {
3759 int rl;
3760
3761 assert(settings);
3762 assert(path);
3763
3764 /* Copy over bits from the settings, unless they have been explicitly masked by command line switches. Note
3765 * that this steals the fields of the Settings* structure, and hence modifies it. */
3766
3767 if ((arg_settings_mask & SETTING_START_MODE) == 0 &&
3768 settings->start_mode >= 0) {
3769 arg_start_mode = settings->start_mode;
3770 strv_free_and_replace(arg_parameters, settings->parameters);
3771 }
3772
3773 if ((arg_settings_mask & SETTING_EPHEMERAL) == 0)
3774 arg_ephemeral = settings->ephemeral;
3775
3776 if ((arg_settings_mask & SETTING_DIRECTORY) == 0 &&
3777 settings->root) {
3778
3779 if (!arg_settings_trusted)
3780 log_warning("Ignoring root directory setting, file %s is not trusted.", path);
3781 else
3782 free_and_replace(arg_directory, settings->root);
3783 }
3784
3785 if ((arg_settings_mask & SETTING_PIVOT_ROOT) == 0 &&
3786 settings->pivot_root_new) {
3787 free_and_replace(arg_pivot_root_new, settings->pivot_root_new);
3788 free_and_replace(arg_pivot_root_old, settings->pivot_root_old);
3789 }
3790
3791 if ((arg_settings_mask & SETTING_WORKING_DIRECTORY) == 0 &&
3792 settings->working_directory)
3793 free_and_replace(arg_chdir, settings->working_directory);
3794
3795 if ((arg_settings_mask & SETTING_ENVIRONMENT) == 0 &&
3796 settings->environment)
3797 strv_free_and_replace(arg_setenv, settings->environment);
3798
3799 if ((arg_settings_mask & SETTING_USER) == 0) {
3800
3801 if (settings->user)
3802 free_and_replace(arg_user, settings->user);
3803
3804 if (uid_is_valid(settings->uid))
3805 arg_uid = settings->uid;
3806 if (gid_is_valid(settings->gid))
3807 arg_gid = settings->gid;
3808 if (settings->n_supplementary_gids > 0) {
3809 free_and_replace(arg_supplementary_gids, settings->supplementary_gids);
3810 arg_n_supplementary_gids = settings->n_supplementary_gids;
3811 }
3812 }
3813
3814 if ((arg_settings_mask & SETTING_CAPABILITY) == 0) {
3815 uint64_t plus, minus;
3816 uint64_t network_minus = 0;
3817
3818 /* Note that we copy both the simple plus/minus caps here, and the full quintet from the
3819 * Settings structure */
3820
3821 plus = settings->capability;
3822 minus = settings->drop_capability;
3823
3824 if ((arg_settings_mask & SETTING_NETWORK) == 0) {
3825 if (settings_private_network(settings))
3826 plus |= UINT64_C(1) << CAP_NET_ADMIN;
3827 else
3828 network_minus |= UINT64_C(1) << CAP_NET_ADMIN;
3829 }
3830
3831 if (!arg_settings_trusted && plus != 0) {
3832 if (settings->capability != 0)
3833 log_warning("Ignoring Capability= setting, file %s is not trusted.", path);
3834 } else {
3835 arg_caps_retain &= ~network_minus;
3836 arg_caps_retain |= plus;
3837 }
3838
3839 arg_caps_retain &= ~minus;
3840
3841 /* Copy the full capabilities over too */
3842 if (capability_quintet_is_set(&settings->full_capabilities)) {
3843 if (!arg_settings_trusted)
3844 log_warning("Ignoring capability settings, file %s is not trusted.", path);
3845 else
3846 arg_full_capabilities = settings->full_capabilities;
3847 }
3848 }
3849
3850 if ((arg_settings_mask & SETTING_KILL_SIGNAL) == 0 &&
3851 settings->kill_signal > 0)
3852 arg_kill_signal = settings->kill_signal;
3853
3854 if ((arg_settings_mask & SETTING_PERSONALITY) == 0 &&
3855 settings->personality != PERSONALITY_INVALID)
3856 arg_personality = settings->personality;
3857
3858 if ((arg_settings_mask & SETTING_MACHINE_ID) == 0 &&
3859 !sd_id128_is_null(settings->machine_id)) {
3860
3861 if (!arg_settings_trusted)
3862 log_warning("Ignoring MachineID= setting, file %s is not trusted.", path);
3863 else
3864 arg_uuid = settings->machine_id;
3865 }
3866
3867 if ((arg_settings_mask & SETTING_READ_ONLY) == 0 &&
3868 settings->read_only >= 0)
3869 arg_read_only = settings->read_only;
3870
3871 if ((arg_settings_mask & SETTING_VOLATILE_MODE) == 0 &&
3872 settings->volatile_mode != _VOLATILE_MODE_INVALID)
3873 arg_volatile_mode = settings->volatile_mode;
3874
3875 if ((arg_settings_mask & SETTING_CUSTOM_MOUNTS) == 0 &&
3876 settings->n_custom_mounts > 0) {
3877
3878 if (!arg_settings_trusted)
3879 log_warning("Ignoring TemporaryFileSystem=, Bind= and BindReadOnly= settings, file %s is not trusted.", path);
3880 else {
3881 custom_mount_free_all(arg_custom_mounts, arg_n_custom_mounts);
3882 arg_custom_mounts = TAKE_PTR(settings->custom_mounts);
3883 arg_n_custom_mounts = settings->n_custom_mounts;
3884 settings->n_custom_mounts = 0;
3885 }
3886 }
3887
3888 if ((arg_settings_mask & SETTING_NETWORK) == 0 &&
3889 (settings->private_network >= 0 ||
3890 settings->network_veth >= 0 ||
3891 settings->network_bridge ||
3892 settings->network_zone ||
3893 settings->network_interfaces ||
3894 settings->network_macvlan ||
3895 settings->network_ipvlan ||
3896 settings->network_veth_extra ||
3897 settings->network_namespace_path)) {
3898
3899 if (!arg_settings_trusted)
3900 log_warning("Ignoring network settings, file %s is not trusted.", path);
3901 else {
3902 arg_network_veth = settings_network_veth(settings);
3903 arg_private_network = settings_private_network(settings);
3904
3905 strv_free_and_replace(arg_network_interfaces, settings->network_interfaces);
3906 strv_free_and_replace(arg_network_macvlan, settings->network_macvlan);
3907 strv_free_and_replace(arg_network_ipvlan, settings->network_ipvlan);
3908 strv_free_and_replace(arg_network_veth_extra, settings->network_veth_extra);
3909
3910 free_and_replace(arg_network_bridge, settings->network_bridge);
3911 free_and_replace(arg_network_zone, settings->network_zone);
3912
3913 free_and_replace(arg_network_namespace_path, settings->network_namespace_path);
3914 }
3915 }
3916
3917 if ((arg_settings_mask & SETTING_EXPOSE_PORTS) == 0 &&
3918 settings->expose_ports) {
3919
3920 if (!arg_settings_trusted)
3921 log_warning("Ignoring Port= setting, file %s is not trusted.", path);
3922 else {
3923 expose_port_free_all(arg_expose_ports);
3924 arg_expose_ports = TAKE_PTR(settings->expose_ports);
3925 }
3926 }
3927
3928 if ((arg_settings_mask & SETTING_USERNS) == 0 &&
3929 settings->userns_mode != _USER_NAMESPACE_MODE_INVALID) {
3930
3931 if (!arg_settings_trusted)
3932 log_warning("Ignoring PrivateUsers= and PrivateUsersChown= settings, file %s is not trusted.", path);
3933 else {
3934 arg_userns_mode = settings->userns_mode;
3935 arg_uid_shift = settings->uid_shift;
3936 arg_uid_range = settings->uid_range;
3937 arg_userns_chown = settings->userns_chown;
3938 }
3939 }
3940
3941 if ((arg_settings_mask & SETTING_NOTIFY_READY) == 0)
3942 arg_notify_ready = settings->notify_ready;
3943
3944 if ((arg_settings_mask & SETTING_SYSCALL_FILTER) == 0) {
3945
3946 if (!arg_settings_trusted && !strv_isempty(settings->syscall_whitelist))
3947 log_warning("Ignoring SystemCallFilter= settings, file %s is not trusted.", path);
3948 else {
3949 strv_free_and_replace(arg_syscall_whitelist, settings->syscall_whitelist);
3950 strv_free_and_replace(arg_syscall_blacklist, settings->syscall_blacklist);
3951 }
3952
3953 #if HAVE_SECCOMP
3954 if (!arg_settings_trusted && settings->seccomp)
3955 log_warning("Ignoring SECCOMP filter, file %s is not trusted.", path);
3956 else {
3957 seccomp_release(arg_seccomp);
3958 arg_seccomp = TAKE_PTR(settings->seccomp);
3959 }
3960 #endif
3961 }
3962
3963 for (rl = 0; rl < _RLIMIT_MAX; rl ++) {
3964 if ((arg_settings_mask & (SETTING_RLIMIT_FIRST << rl)))
3965 continue;
3966
3967 if (!settings->rlimit[rl])
3968 continue;
3969
3970 if (!arg_settings_trusted) {
3971 log_warning("Ignoring Limit%s= setting, file '%s' is not trusted.", rlimit_to_string(rl), path);
3972 continue;
3973 }
3974
3975 free_and_replace(arg_rlimit[rl], settings->rlimit[rl]);
3976 }
3977
3978 if ((arg_settings_mask & SETTING_HOSTNAME) == 0 &&
3979 settings->hostname)
3980 free_and_replace(arg_hostname, settings->hostname);
3981
3982 if ((arg_settings_mask & SETTING_NO_NEW_PRIVILEGES) == 0 &&
3983 settings->no_new_privileges >= 0)
3984 arg_no_new_privileges = settings->no_new_privileges;
3985
3986 if ((arg_settings_mask & SETTING_OOM_SCORE_ADJUST) == 0 &&
3987 settings->oom_score_adjust_set) {
3988
3989 if (!arg_settings_trusted)
3990 log_warning("Ignoring OOMScoreAdjust= setting, file '%s' is not trusted.", path);
3991 else {
3992 arg_oom_score_adjust = settings->oom_score_adjust;
3993 arg_oom_score_adjust_set = true;
3994 }
3995 }
3996
3997 if ((arg_settings_mask & SETTING_CPU_AFFINITY) == 0 &&
3998 settings->cpu_set.set) {
3999
4000 if (!arg_settings_trusted)
4001 log_warning("Ignoring CPUAffinity= setting, file '%s' is not trusted.", path);
4002 else {
4003 cpu_set_reset(&arg_cpu_set);
4004 arg_cpu_set = settings->cpu_set;
4005 settings->cpu_set = (CPUSet) {};
4006 }
4007 }
4008
4009 if ((arg_settings_mask & SETTING_RESOLV_CONF) == 0 &&
4010 settings->resolv_conf != _RESOLV_CONF_MODE_INVALID)
4011 arg_resolv_conf = settings->resolv_conf;
4012
4013 if ((arg_settings_mask & SETTING_LINK_JOURNAL) == 0 &&
4014 settings->link_journal != _LINK_JOURNAL_INVALID) {
4015
4016 if (!arg_settings_trusted)
4017 log_warning("Ignoring journal link setting, file '%s' is not trusted.", path);
4018 else {
4019 arg_link_journal = settings->link_journal;
4020 arg_link_journal_try = settings->link_journal_try;
4021 }
4022 }
4023
4024 if ((arg_settings_mask & SETTING_TIMEZONE) == 0 &&
4025 settings->timezone != _TIMEZONE_MODE_INVALID)
4026 arg_timezone = settings->timezone;
4027
4028 if ((arg_settings_mask & SETTING_SLICE) == 0 &&
4029 settings->slice) {
4030
4031 if (!arg_settings_trusted)
4032 log_warning("Ignoring slice setting, file '%s' is not trusted.", path);
4033 else
4034 free_and_replace(arg_slice, settings->slice);
4035 }
4036
4037 if ((arg_settings_mask & SETTING_USE_CGNS) == 0 &&
4038 settings->use_cgns >= 0) {
4039
4040 if (!arg_settings_trusted)
4041 log_warning("Ignoring cgroup namespace setting, file '%s' is not trusted.", path);
4042 else
4043 arg_use_cgns = settings->use_cgns;
4044 }
4045
4046 if ((arg_settings_mask & SETTING_CLONE_NS_FLAGS) == 0 &&
4047 settings->clone_ns_flags != (unsigned long) -1) {
4048
4049 if (!arg_settings_trusted)
4050 log_warning("Ignoring namespace setting, file '%s' is not trusted.", path);
4051 else
4052 arg_clone_ns_flags = settings->clone_ns_flags;
4053 }
4054
4055 if ((arg_settings_mask & SETTING_CONSOLE_MODE) == 0 &&
4056 settings->console_mode >= 0) {
4057
4058 if (!arg_settings_trusted)
4059 log_warning("Ignoring console mode setting, file '%s' is not trusted.", path);
4060 else
4061 arg_console_mode = settings->console_mode;
4062 }
4063
4064 /* The following properties can only be set through the OCI settings logic, not from the command line, hence we
4065 * don't consult arg_settings_mask for them. */
4066
4067 sd_bus_message_unref(arg_property_message);
4068 arg_property_message = TAKE_PTR(settings->properties);
4069
4070 arg_console_width = settings->console_width;
4071 arg_console_height = settings->console_height;
4072
4073 device_node_array_free(arg_extra_nodes, arg_n_extra_nodes);
4074 arg_extra_nodes = TAKE_PTR(settings->extra_nodes);
4075 arg_n_extra_nodes = settings->n_extra_nodes;
4076
4077 return 0;
4078 }
4079
4080 static int load_settings(void) {
4081 _cleanup_(settings_freep) Settings *settings = NULL;
4082 _cleanup_fclose_ FILE *f = NULL;
4083 _cleanup_free_ char *p = NULL;
4084 const char *fn, *i;
4085 int r;
4086
4087 if (arg_oci_bundle)
4088 return 0;
4089
4090 /* If all settings are masked, there's no point in looking for
4091 * the settings file */
4092 if ((arg_settings_mask & _SETTINGS_MASK_ALL) == _SETTINGS_MASK_ALL)
4093 return 0;
4094
4095 fn = strjoina(arg_machine, ".nspawn");
4096
4097 /* We first look in the admin's directories in /etc and /run */
4098 FOREACH_STRING(i, "/etc/systemd/nspawn", "/run/systemd/nspawn") {
4099 _cleanup_free_ char *j = NULL;
4100
4101 j = path_join(i, fn);
4102 if (!j)
4103 return log_oom();
4104
4105 f = fopen(j, "re");
4106 if (f) {
4107 p = TAKE_PTR(j);
4108
4109 /* By default, we trust configuration from /etc and /run */
4110 if (arg_settings_trusted < 0)
4111 arg_settings_trusted = true;
4112
4113 break;
4114 }
4115
4116 if (errno != ENOENT)
4117 return log_error_errno(errno, "Failed to open %s: %m", j);
4118 }
4119
4120 if (!f) {
4121 /* After that, let's look for a file next to the
4122 * actual image we shall boot. */
4123
4124 if (arg_image) {
4125 p = file_in_same_dir(arg_image, fn);
4126 if (!p)
4127 return log_oom();
4128 } else if (arg_directory && !path_equal(arg_directory, "/")) {
4129 p = file_in_same_dir(arg_directory, fn);
4130 if (!p)
4131 return log_oom();
4132 }
4133
4134 if (p) {
4135 f = fopen(p, "re");
4136 if (!f && errno != ENOENT)
4137 return log_error_errno(errno, "Failed to open %s: %m", p);
4138
4139 /* By default, we do not trust configuration from /var/lib/machines */
4140 if (arg_settings_trusted < 0)
4141 arg_settings_trusted = false;
4142 }
4143 }
4144
4145 if (!f)
4146 return 0;
4147
4148 log_debug("Settings are trusted: %s", yes_no(arg_settings_trusted));
4149
4150 r = settings_load(f, p, &settings);
4151 if (r < 0)
4152 return r;
4153
4154 return merge_settings(settings, p);
4155 }
4156
4157 static int load_oci_bundle(void) {
4158 _cleanup_(settings_freep) Settings *settings = NULL;
4159 int r;
4160
4161 if (!arg_oci_bundle)
4162 return 0;
4163
4164 /* By default let's trust OCI bundles */
4165 if (arg_settings_trusted < 0)
4166 arg_settings_trusted = true;
4167
4168 r = oci_load(NULL, arg_oci_bundle, &settings);
4169 if (r < 0)
4170 return r;
4171
4172 return merge_settings(settings, arg_oci_bundle);
4173 }
4174
4175 static int run_container(
4176 DissectedImage *dissected_image,
4177 bool secondary,
4178 FDSet *fds,
4179 char veth_name[IFNAMSIZ], bool *veth_created,
4180 union in_addr_union *exposed,
4181 int *master, pid_t *pid, int *ret) {
4182
4183 static const struct sigaction sa = {
4184 .sa_handler = nop_signal_handler,
4185 .sa_flags = SA_NOCLDSTOP|SA_RESTART,
4186 };
4187
4188 _cleanup_(release_lock_file) LockFile uid_shift_lock = LOCK_FILE_INIT;
4189 _cleanup_close_ int etc_passwd_lock = -1;
4190 _cleanup_close_pair_ int
4191 kmsg_socket_pair[2] = { -1, -1 },
4192 rtnl_socket_pair[2] = { -1, -1 },
4193 pid_socket_pair[2] = { -1, -1 },
4194 uuid_socket_pair[2] = { -1, -1 },
4195 notify_socket_pair[2] = { -1, -1 },
4196 uid_shift_socket_pair[2] = { -1, -1 },
4197 master_pty_socket_pair[2] = { -1, -1 },
4198 unified_cgroup_hierarchy_socket_pair[2] = { -1, -1};
4199
4200 _cleanup_close_ int notify_socket = -1;
4201 _cleanup_(barrier_destroy) Barrier barrier = BARRIER_NULL;
4202 _cleanup_(sd_event_source_unrefp) sd_event_source *notify_event_source = NULL;
4203 _cleanup_(sd_event_unrefp) sd_event *event = NULL;
4204 _cleanup_(pty_forward_freep) PTYForward *forward = NULL;
4205 _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL;
4206 _cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL;
4207 ContainerStatus container_status = 0;
4208 int ifi = 0, r;
4209 ssize_t l;
4210 sigset_t mask_chld;
4211 _cleanup_close_ int child_netns_fd = -1;
4212
4213 assert_se(sigemptyset(&mask_chld) == 0);
4214 assert_se(sigaddset(&mask_chld, SIGCHLD) == 0);
4215
4216 if (arg_userns_mode == USER_NAMESPACE_PICK) {
4217 /* When we shall pick the UID/GID range, let's first lock /etc/passwd, so that we can safely
4218 * check with getpwuid() if the specific user already exists. Note that /etc might be
4219 * read-only, in which case this will fail with EROFS. But that's really OK, as in that case we
4220 * can be reasonably sure that no users are going to be added. Note that getpwuid() checks are
4221 * really just an extra safety net. We kinda assume that the UID range we allocate from is
4222 * really ours. */
4223
4224 etc_passwd_lock = take_etc_passwd_lock(NULL);
4225 if (etc_passwd_lock < 0 && etc_passwd_lock != -EROFS)
4226 return log_error_errno(etc_passwd_lock, "Failed to take /etc/passwd lock: %m");
4227 }
4228
4229 r = barrier_create(&barrier);
4230 if (r < 0)
4231 return log_error_errno(r, "Cannot initialize IPC barrier: %m");
4232
4233 if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, kmsg_socket_pair) < 0)
4234 return log_error_errno(errno, "Failed to create kmsg socket pair: %m");
4235
4236 if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, rtnl_socket_pair) < 0)
4237 return log_error_errno(errno, "Failed to create rtnl socket pair: %m");
4238
4239 if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, pid_socket_pair) < 0)
4240 return log_error_errno(errno, "Failed to create pid socket pair: %m");
4241
4242 if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, uuid_socket_pair) < 0)
4243 return log_error_errno(errno, "Failed to create id socket pair: %m");
4244
4245 if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, notify_socket_pair) < 0)
4246 return log_error_errno(errno, "Failed to create notify socket pair: %m");
4247
4248 if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, master_pty_socket_pair) < 0)
4249 return log_error_errno(errno, "Failed to create console socket pair: %m");
4250
4251 if (arg_userns_mode != USER_NAMESPACE_NO)
4252 if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, uid_shift_socket_pair) < 0)
4253 return log_error_errno(errno, "Failed to create uid shift socket pair: %m");
4254
4255 if (arg_unified_cgroup_hierarchy == CGROUP_UNIFIED_UNKNOWN)
4256 if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, unified_cgroup_hierarchy_socket_pair) < 0)
4257 return log_error_errno(errno, "Failed to create unified cgroup socket pair: %m");
4258
4259 /* Child can be killed before execv(), so handle SIGCHLD in order to interrupt
4260 * parent's blocking calls and give it a chance to call wait() and terminate. */
4261 r = sigprocmask(SIG_UNBLOCK, &mask_chld, NULL);
4262 if (r < 0)
4263 return log_error_errno(errno, "Failed to change the signal mask: %m");
4264
4265 r = sigaction(SIGCHLD, &sa, NULL);
4266 if (r < 0)
4267 return log_error_errno(errno, "Failed to install SIGCHLD handler: %m");
4268
4269 if (arg_network_namespace_path) {
4270 child_netns_fd = open(arg_network_namespace_path, O_RDONLY|O_NOCTTY|O_CLOEXEC);
4271 if (child_netns_fd < 0)
4272 return log_error_errno(errno, "Cannot open file %s: %m", arg_network_namespace_path);
4273
4274 r = fd_is_network_ns(child_netns_fd);
4275 if (r == -EUCLEAN)
4276 log_debug_errno(r, "Cannot determine if passed network namespace path '%s' really refers to a network namespace, assuming it does.", arg_network_namespace_path);
4277 else if (r < 0)
4278 return log_error_errno(r, "Failed to check %s fs type: %m", arg_network_namespace_path);
4279 else if (r == 0)
4280 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
4281 "Path %s doesn't refer to a network namespace, refusing.", arg_network_namespace_path);
4282 }
4283
4284 *pid = raw_clone(SIGCHLD|CLONE_NEWNS);
4285 if (*pid < 0)
4286 return log_error_errno(errno, "clone() failed%s: %m",
4287 errno == EINVAL ?
4288 ", do you have namespace support enabled in your kernel? (You need UTS, IPC, PID and NET namespacing built in)" : "");
4289
4290 if (*pid == 0) {
4291 /* The outer child only has a file system namespace. */
4292 barrier_set_role(&barrier, BARRIER_CHILD);
4293
4294 kmsg_socket_pair[0] = safe_close(kmsg_socket_pair[0]);
4295 rtnl_socket_pair[0] = safe_close(rtnl_socket_pair[0]);
4296 pid_socket_pair[0] = safe_close(pid_socket_pair[0]);
4297 uuid_socket_pair[0] = safe_close(uuid_socket_pair[0]);
4298 notify_socket_pair[0] = safe_close(notify_socket_pair[0]);
4299 master_pty_socket_pair[0] = safe_close(master_pty_socket_pair[0]);
4300 uid_shift_socket_pair[0] = safe_close(uid_shift_socket_pair[0]);
4301 unified_cgroup_hierarchy_socket_pair[0] = safe_close(unified_cgroup_hierarchy_socket_pair[0]);
4302
4303 (void) reset_all_signal_handlers();
4304 (void) reset_signal_mask();
4305
4306 r = outer_child(&barrier,
4307 arg_directory,
4308 dissected_image,
4309 secondary,
4310 pid_socket_pair[1],
4311 uuid_socket_pair[1],
4312 notify_socket_pair[1],
4313 kmsg_socket_pair[1],
4314 rtnl_socket_pair[1],
4315 uid_shift_socket_pair[1],
4316 master_pty_socket_pair[1],
4317 unified_cgroup_hierarchy_socket_pair[1],
4318 fds,
4319 child_netns_fd);
4320 if (r < 0)
4321 _exit(EXIT_FAILURE);
4322
4323 _exit(EXIT_SUCCESS);
4324 }
4325
4326 barrier_set_role(&barrier, BARRIER_PARENT);
4327
4328 fdset_close(fds);
4329
4330 kmsg_socket_pair[1] = safe_close(kmsg_socket_pair[1]);
4331 rtnl_socket_pair[1] = safe_close(rtnl_socket_pair[1]);
4332 pid_socket_pair[1] = safe_close(pid_socket_pair[1]);
4333 uuid_socket_pair[1] = safe_close(uuid_socket_pair[1]);
4334 notify_socket_pair[1] = safe_close(notify_socket_pair[1]);
4335 master_pty_socket_pair[1] = safe_close(master_pty_socket_pair[1]);
4336 uid_shift_socket_pair[1] = safe_close(uid_shift_socket_pair[1]);
4337 unified_cgroup_hierarchy_socket_pair[1] = safe_close(unified_cgroup_hierarchy_socket_pair[1]);
4338
4339 if (arg_userns_mode != USER_NAMESPACE_NO) {
4340 /* The child just let us know the UID shift it might have read from the image. */
4341 l = recv(uid_shift_socket_pair[0], &arg_uid_shift, sizeof arg_uid_shift, 0);
4342 if (l < 0)
4343 return log_error_errno(errno, "Failed to read UID shift: %m");
4344 if (l != sizeof arg_uid_shift)
4345 return log_error_errno(SYNTHETIC_ERRNO(EIO), "Short read while reading UID shift.");
4346
4347 if (arg_userns_mode == USER_NAMESPACE_PICK) {
4348 /* If we are supposed to pick the UID shift, let's try to use the shift read from the
4349 * image, but if that's already in use, pick a new one, and report back to the child,
4350 * which one we now picked. */
4351
4352 r = uid_shift_pick(&arg_uid_shift, &uid_shift_lock);
4353 if (r < 0)
4354 return log_error_errno(r, "Failed to pick suitable UID/GID range: %m");
4355
4356 l = send(uid_shift_socket_pair[0], &arg_uid_shift, sizeof arg_uid_shift, MSG_NOSIGNAL);
4357 if (l < 0)
4358 return log_error_errno(errno, "Failed to send UID shift: %m");
4359 if (l != sizeof arg_uid_shift)
4360 return log_error_errno(SYNTHETIC_ERRNO(EIO), "Short write while writing UID shift.");
4361 }
4362 }
4363
4364 if (arg_unified_cgroup_hierarchy == CGROUP_UNIFIED_UNKNOWN) {
4365 /* The child let us know the support cgroup mode it might have read from the image. */
4366 l = recv(unified_cgroup_hierarchy_socket_pair[0], &arg_unified_cgroup_hierarchy, sizeof(arg_unified_cgroup_hierarchy), 0);
4367 if (l < 0)
4368 return log_error_errno(errno, "Failed to read cgroup mode: %m");
4369 if (l != sizeof(arg_unified_cgroup_hierarchy))
4370 return log_error_errno(SYNTHETIC_ERRNO(EIO), "Short read while reading cgroup mode (%zu bytes).%s",
4371 l, l == 0 ? " The child is most likely dead." : "");
4372 }
4373
4374 /* Wait for the outer child. */
4375 r = wait_for_terminate_and_check("(sd-namespace)", *pid, WAIT_LOG_ABNORMAL);
4376 if (r < 0)
4377 return r;
4378 if (r != EXIT_SUCCESS)
4379 return -EIO;
4380
4381 /* And now retrieve the PID of the inner child. */
4382 l = recv(pid_socket_pair[0], pid, sizeof *pid, 0);
4383 if (l < 0)
4384 return log_error_errno(errno, "Failed to read inner child PID: %m");
4385 if (l != sizeof *pid)
4386 return log_error_errno(SYNTHETIC_ERRNO(EIO), "Short read while reading inner child PID.");
4387
4388 /* We also retrieve container UUID in case it was generated by outer child */
4389 l = recv(uuid_socket_pair[0], &arg_uuid, sizeof arg_uuid, 0);
4390 if (l < 0)
4391 return log_error_errno(errno, "Failed to read container machine ID: %m");
4392 if (l != sizeof(arg_uuid))
4393 return log_error_errno(SYNTHETIC_ERRNO(EIO), "Short read while reading container machined ID.");
4394
4395 /* We also retrieve the socket used for notifications generated by outer child */
4396 notify_socket = receive_one_fd(notify_socket_pair[0], 0);
4397 if (notify_socket < 0)
4398 return log_error_errno(notify_socket,
4399 "Failed to receive notification socket from the outer child: %m");
4400
4401 log_debug("Init process invoked as PID "PID_FMT, *pid);
4402
4403 if (arg_userns_mode != USER_NAMESPACE_NO) {
4404 if (!barrier_place_and_sync(&barrier)) /* #1 */
4405 return log_error_errno(SYNTHETIC_ERRNO(ESRCH), "Child died too early.");
4406
4407 r = setup_uid_map(*pid);
4408 if (r < 0)
4409 return r;
4410
4411 (void) barrier_place(&barrier); /* #2 */
4412 }
4413
4414 if (arg_private_network) {
4415 if (!arg_network_namespace_path) {
4416 /* Wait until the child has unshared its network namespace. */
4417 if (!barrier_place_and_sync(&barrier)) /* #3 */
4418 return log_error_errno(SYNTHETIC_ERRNO(ESRCH), "Child died too early");
4419 }
4420
4421 if (child_netns_fd < 0) {
4422 /* Make sure we have an open file descriptor to the child's network
4423 * namespace so it stays alive even if the child exits. */
4424 r = namespace_open(*pid, NULL, NULL, &child_netns_fd, NULL, NULL);
4425 if (r < 0)
4426 return log_error_errno(r, "Failed to open child network namespace: %m");
4427 }
4428
4429 r = move_network_interfaces(child_netns_fd, arg_network_interfaces);
4430 if (r < 0)
4431 return r;
4432
4433 if (arg_network_veth) {
4434 r = setup_veth(arg_machine, *pid, veth_name,
4435 arg_network_bridge || arg_network_zone);
4436 if (r < 0)
4437 return r;
4438 else if (r > 0)
4439 ifi = r;
4440
4441 if (arg_network_bridge) {
4442 /* Add the interface to a bridge */
4443 r = setup_bridge(veth_name, arg_network_bridge, false);
4444 if (r < 0)
4445 return r;
4446 if (r > 0)
4447 ifi = r;
4448 } else if (arg_network_zone) {
4449 /* Add the interface to a bridge, possibly creating it */
4450 r = setup_bridge(veth_name, arg_network_zone, true);
4451 if (r < 0)
4452 return r;
4453 if (r > 0)
4454 ifi = r;
4455 }
4456 }
4457
4458 r = setup_veth_extra(arg_machine, *pid, arg_network_veth_extra);
4459 if (r < 0)
4460 return r;
4461
4462 /* We created the primary and extra veth links now; let's remember this, so that we know to
4463 remove them later on. Note that we don't bother with removing veth links that were created
4464 here when their setup failed half-way, because in that case the kernel should be able to
4465 remove them on its own, since they cannot be referenced by anything yet. */
4466 *veth_created = true;
4467
4468 r = setup_macvlan(arg_machine, *pid, arg_network_macvlan);
4469 if (r < 0)
4470 return r;
4471
4472 r = setup_ipvlan(arg_machine, *pid, arg_network_ipvlan);
4473 if (r < 0)
4474 return r;
4475 }
4476
4477 if (arg_register || !arg_keep_unit) {
4478 r = sd_bus_default_system(&bus);
4479 if (r < 0)
4480 return log_error_errno(r, "Failed to open system bus: %m");
4481
4482 r = sd_bus_set_close_on_exit(bus, false);
4483 if (r < 0)
4484 return log_error_errno(r, "Failed to disable close-on-exit behaviour: %m");
4485 }
4486
4487 if (!arg_keep_unit) {
4488 /* When a new scope is created for this container, then we'll be registered as its controller, in which
4489 * case PID 1 will send us a friendly RequestStop signal, when it is asked to terminate the
4490 * scope. Let's hook into that, and cleanly shut down the container, and print a friendly message. */
4491
4492 r = sd_bus_match_signal_async(
4493 bus,
4494 NULL,
4495 "org.freedesktop.systemd1",
4496 NULL,
4497 "org.freedesktop.systemd1.Scope",
4498 "RequestStop",
4499 on_request_stop, NULL, PID_TO_PTR(*pid));
4500 if (r < 0)
4501 return log_error_errno(r, "Failed to request RequestStop match: %m");
4502 }
4503
4504 if (arg_register) {
4505 r = register_machine(
4506 bus,
4507 arg_machine,
4508 *pid,
4509 arg_directory,
4510 arg_uuid,
4511 ifi,
4512 arg_slice,
4513 arg_custom_mounts, arg_n_custom_mounts,
4514 arg_kill_signal,
4515 arg_property,
4516 arg_property_message,
4517 arg_keep_unit,
4518 arg_container_service_name);
4519 if (r < 0)
4520 return r;
4521
4522 } else if (!arg_keep_unit) {
4523 r = allocate_scope(
4524 bus,
4525 arg_machine,
4526 *pid,
4527 arg_slice,
4528 arg_custom_mounts, arg_n_custom_mounts,
4529 arg_kill_signal,
4530 arg_property,
4531 arg_property_message);
4532 if (r < 0)
4533 return r;
4534
4535 } else if (arg_slice || arg_property)
4536 log_notice("Machine and scope registration turned off, --slice= and --property= settings will have no effect.");
4537
4538 r = create_subcgroup(*pid, arg_keep_unit, arg_unified_cgroup_hierarchy);
4539 if (r < 0)
4540 return r;
4541
4542 r = sync_cgroup(*pid, arg_unified_cgroup_hierarchy, arg_uid_shift);
4543 if (r < 0)
4544 return r;
4545
4546 r = chown_cgroup(*pid, arg_unified_cgroup_hierarchy, arg_uid_shift);
4547 if (r < 0)
4548 return r;
4549
4550 /* Notify the child that the parent is ready with all
4551 * its setup (including cgroup-ification), and that
4552 * the child can now hand over control to the code to
4553 * run inside the container. */
4554 (void) barrier_place(&barrier); /* #4 */
4555
4556 /* Block SIGCHLD here, before notifying child.
4557 * process_pty() will handle it with the other signals. */
4558 assert_se(sigprocmask(SIG_BLOCK, &mask_chld, NULL) >= 0);
4559
4560 /* Reset signal to default */
4561 r = default_signals(SIGCHLD, -1);
4562 if (r < 0)
4563 return log_error_errno(r, "Failed to reset SIGCHLD: %m");
4564
4565 r = sd_event_new(&event);
4566 if (r < 0)
4567 return log_error_errno(r, "Failed to get default event source: %m");
4568
4569 (void) sd_event_set_watchdog(event, true);
4570
4571 if (bus) {
4572 r = sd_bus_attach_event(bus, event, 0);
4573 if (r < 0)
4574 return log_error_errno(r, "Failed to attach bus to event loop: %m");
4575 }
4576
4577 r = setup_sd_notify_parent(event, notify_socket, PID_TO_PTR(*pid), &notify_event_source);
4578 if (r < 0)
4579 return r;
4580
4581 /* Let the child know that we are ready and wait that the child is completely ready now. */
4582 if (!barrier_place_and_sync(&barrier)) /* #5 */
4583 return log_error_errno(SYNTHETIC_ERRNO(ESRCH), "Child died too early.");
4584
4585 /* At this point we have made use of the UID we picked, and thus nss-mymachines
4586 * will make them appear in getpwuid(), thus we can release the /etc/passwd lock. */
4587 etc_passwd_lock = safe_close(etc_passwd_lock);
4588
4589 (void) sd_notifyf(false,
4590 "STATUS=Container running.\n"
4591 "X_NSPAWN_LEADER_PID=" PID_FMT, *pid);
4592 if (!arg_notify_ready)
4593 (void) sd_notify(false, "READY=1\n");
4594
4595 if (arg_kill_signal > 0) {
4596 /* Try to kill the init system on SIGINT or SIGTERM */
4597 (void) sd_event_add_signal(event, NULL, SIGINT, on_orderly_shutdown, PID_TO_PTR(*pid));
4598 (void) sd_event_add_signal(event, NULL, SIGTERM, on_orderly_shutdown, PID_TO_PTR(*pid));
4599 } else {
4600 /* Immediately exit */
4601 (void) sd_event_add_signal(event, NULL, SIGINT, NULL, NULL);
4602 (void) sd_event_add_signal(event, NULL, SIGTERM, NULL, NULL);
4603 }
4604
4605 /* Exit when the child exits */
4606 (void) sd_event_add_signal(event, NULL, SIGCHLD, on_sigchld, PID_TO_PTR(*pid));
4607
4608 if (arg_expose_ports) {
4609 r = expose_port_watch_rtnl(event, rtnl_socket_pair[0], on_address_change, exposed, &rtnl);
4610 if (r < 0)
4611 return r;
4612
4613 (void) expose_port_execute(rtnl, arg_expose_ports, exposed);
4614 }
4615
4616 rtnl_socket_pair[0] = safe_close(rtnl_socket_pair[0]);
4617
4618 if (arg_console_mode != CONSOLE_PIPE) {
4619 _cleanup_close_ int fd = -1;
4620 PTYForwardFlags flags = 0;
4621
4622 /* Retrieve the master pty allocated by inner child */
4623 fd = receive_one_fd(master_pty_socket_pair[0], 0);
4624 if (fd < 0)
4625 return log_error_errno(fd, "Failed to receive master pty from the inner child: %m");
4626
4627 switch (arg_console_mode) {
4628
4629 case CONSOLE_READ_ONLY:
4630 flags |= PTY_FORWARD_READ_ONLY;
4631
4632 _fallthrough_;
4633
4634 case CONSOLE_INTERACTIVE:
4635 flags |= PTY_FORWARD_IGNORE_VHANGUP;
4636
4637 r = pty_forward_new(event, fd, flags, &forward);
4638 if (r < 0)
4639 return log_error_errno(r, "Failed to create PTY forwarder: %m");
4640
4641 if (arg_console_width != (unsigned) -1 || arg_console_height != (unsigned) -1)
4642 (void) pty_forward_set_width_height(forward,
4643 arg_console_width,
4644 arg_console_height);
4645 break;
4646
4647 default:
4648 assert(arg_console_mode == CONSOLE_PASSIVE);
4649 }
4650
4651 *master = TAKE_FD(fd);
4652 }
4653
4654 r = sd_event_loop(event);
4655 if (r < 0)
4656 return log_error_errno(r, "Failed to run event loop: %m");
4657
4658 if (forward) {
4659 char last_char = 0;
4660
4661 (void) pty_forward_get_last_char(forward, &last_char);
4662 forward = pty_forward_free(forward);
4663
4664 if (!arg_quiet && last_char != '\n')
4665 putc('\n', stdout);
4666 }
4667
4668 /* Kill if it is not dead yet anyway */
4669 if (!arg_register && !arg_keep_unit && bus)
4670 terminate_scope(bus, arg_machine);
4671
4672 /* Normally redundant, but better safe than sorry */
4673 (void) kill(*pid, SIGKILL);
4674
4675 if (arg_private_network) {
4676 /* Move network interfaces back to the parent network namespace. We use `safe_fork`
4677 * to avoid having to move the parent to the child network namespace. */
4678 r = safe_fork(NULL, FORK_RESET_SIGNALS|FORK_DEATHSIG|FORK_WAIT|FORK_LOG, NULL);
4679 if (r < 0)
4680 return r;
4681
4682 if (r == 0) {
4683 _cleanup_close_ int parent_netns_fd = -1;
4684
4685 r = namespace_open(getpid(), NULL, NULL, &parent_netns_fd, NULL, NULL);
4686 if (r < 0) {
4687 log_error_errno(r, "Failed to open parent network namespace: %m");
4688 _exit(EXIT_FAILURE);
4689 }
4690
4691 r = namespace_enter(-1, -1, child_netns_fd, -1, -1);
4692 if (r < 0) {
4693 log_error_errno(r, "Failed to enter child network namespace: %m");
4694 _exit(EXIT_FAILURE);
4695 }
4696
4697 r = move_network_interfaces(parent_netns_fd, arg_network_interfaces);
4698 if (r < 0)
4699 log_error_errno(r, "Failed to move network interfaces back to parent network namespace: %m");
4700
4701 _exit(r < 0 ? EXIT_FAILURE : EXIT_SUCCESS);
4702 }
4703 }
4704
4705 r = wait_for_container(*pid, &container_status);
4706 *pid = 0;
4707
4708 /* Tell machined that we are gone. */
4709 if (bus)
4710 (void) unregister_machine(bus, arg_machine);
4711
4712 if (r < 0)
4713 /* We failed to wait for the container, or the container exited abnormally. */
4714 return r;
4715 if (r > 0 || container_status == CONTAINER_TERMINATED) {
4716 /* r > 0 → The container exited with a non-zero status.
4717 * As a special case, we need to replace 133 with a different value,
4718 * because 133 is special-cased in the service file to reboot the container.
4719 * otherwise → The container exited with zero status and a reboot was not requested.
4720 */
4721 if (r == EXIT_FORCE_RESTART)
4722 r = EXIT_FAILURE; /* replace 133 with the general failure code */
4723 *ret = r;
4724 return 0; /* finito */
4725 }
4726
4727 /* CONTAINER_REBOOTED, loop again */
4728
4729 if (arg_keep_unit) {
4730 /* Special handling if we are running as a service: instead of simply
4731 * restarting the machine we want to restart the entire service, so let's
4732 * inform systemd about this with the special exit code 133. The service
4733 * file uses RestartForceExitStatus=133 so that this results in a full
4734 * nspawn restart. This is necessary since we might have cgroup parameters
4735 * set we want to have flushed out. */
4736 *ret = EXIT_FORCE_RESTART;
4737 return 0; /* finito */
4738 }
4739
4740 expose_port_flush(arg_expose_ports, exposed);
4741
4742 (void) remove_veth_links(veth_name, arg_network_veth_extra);
4743 *veth_created = false;
4744 return 1; /* loop again */
4745 }
4746
4747 static int initialize_rlimits(void) {
4748 /* The default resource limits the kernel passes to PID 1, as per kernel 4.16. Let's pass our container payload
4749 * the same values as the kernel originally passed to PID 1, in order to minimize differences between host and
4750 * container execution environments. */
4751
4752 static const struct rlimit kernel_defaults[_RLIMIT_MAX] = {
4753 [RLIMIT_AS] = { RLIM_INFINITY, RLIM_INFINITY },
4754 [RLIMIT_CORE] = { 0, RLIM_INFINITY },
4755 [RLIMIT_CPU] = { RLIM_INFINITY, RLIM_INFINITY },
4756 [RLIMIT_DATA] = { RLIM_INFINITY, RLIM_INFINITY },
4757 [RLIMIT_FSIZE] = { RLIM_INFINITY, RLIM_INFINITY },
4758 [RLIMIT_LOCKS] = { RLIM_INFINITY, RLIM_INFINITY },
4759 [RLIMIT_MEMLOCK] = { 65536, 65536 },
4760 [RLIMIT_MSGQUEUE] = { 819200, 819200 },
4761 [RLIMIT_NICE] = { 0, 0 },
4762 [RLIMIT_NOFILE] = { 1024, 4096 },
4763 [RLIMIT_RSS] = { RLIM_INFINITY, RLIM_INFINITY },
4764 [RLIMIT_RTPRIO] = { 0, 0 },
4765 [RLIMIT_RTTIME] = { RLIM_INFINITY, RLIM_INFINITY },
4766 [RLIMIT_STACK] = { 8388608, RLIM_INFINITY },
4767
4768 /* The kernel scales the default for RLIMIT_NPROC and RLIMIT_SIGPENDING based on the system's amount of
4769 * RAM. To provide best compatibility we'll read these limits off PID 1 instead of hardcoding them
4770 * here. This is safe as we know that PID 1 doesn't change these two limits and thus the original
4771 * kernel's initialization should still be valid during runtime — at least if PID 1 is systemd. Note
4772 * that PID 1 changes a number of other resource limits during early initialization which is why we
4773 * don't read the other limits from PID 1 but prefer the static table above. */
4774 };
4775
4776 int rl;
4777
4778 for (rl = 0; rl < _RLIMIT_MAX; rl++) {
4779 /* Let's only fill in what the user hasn't explicitly configured anyway */
4780 if ((arg_settings_mask & (SETTING_RLIMIT_FIRST << rl)) == 0) {
4781 const struct rlimit *v;
4782 struct rlimit buffer;
4783
4784 if (IN_SET(rl, RLIMIT_NPROC, RLIMIT_SIGPENDING)) {
4785 /* For these two let's read the limits off PID 1. See above for an explanation. */
4786
4787 if (prlimit(1, rl, NULL, &buffer) < 0)
4788 return log_error_errno(errno, "Failed to read resource limit RLIMIT_%s of PID 1: %m", rlimit_to_string(rl));
4789
4790 v = &buffer;
4791 } else
4792 v = kernel_defaults + rl;
4793
4794 arg_rlimit[rl] = newdup(struct rlimit, v, 1);
4795 if (!arg_rlimit[rl])
4796 return log_oom();
4797 }
4798
4799 if (DEBUG_LOGGING) {
4800 _cleanup_free_ char *k = NULL;
4801
4802 (void) rlimit_format(arg_rlimit[rl], &k);
4803 log_debug("Setting RLIMIT_%s to %s.", rlimit_to_string(rl), k);
4804 }
4805 }
4806
4807 return 0;
4808 }
4809
4810 static int cant_be_in_netns(void) {
4811 union sockaddr_union sa = {
4812 .un = {
4813 .sun_family = AF_UNIX,
4814 .sun_path = "/run/udev/control",
4815 },
4816 };
4817 char udev_path[STRLEN("/proc//ns/net") + DECIMAL_STR_MAX(pid_t)];
4818 _cleanup_free_ char *udev_ns = NULL, *our_ns = NULL;
4819 _cleanup_close_ int fd = -1;
4820 struct ucred ucred;
4821 int r;
4822
4823 /* Check if we are in the same netns as udev. If we aren't, then device monitoring (and thus waiting
4824 * for loopback block devices) won't work, and we will hang. Detect this case and exit early with a
4825 * nice message. */
4826
4827 if (!arg_image) /* only matters if --image= us used, i.e. we actually need to use loopback devices */
4828 return 0;
4829
4830 fd = socket(AF_UNIX, SOCK_SEQPACKET|SOCK_NONBLOCK|SOCK_CLOEXEC, 0);
4831 if (fd < 0)
4832 return log_error_errno(errno, "Failed to allocate udev control socket: %m");
4833
4834 if (connect(fd, &sa.un, SOCKADDR_UN_LEN(sa.un)) < 0) {
4835
4836 if (errno == ENOENT || ERRNO_IS_DISCONNECT(errno))
4837 return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP),
4838 "Sorry, but --image= requires access to the host's /run/ hierarchy, since we need access to udev.");
4839
4840 return log_error_errno(errno, "Failed to connect socket to udev control socket: %m");
4841 }
4842
4843 r = getpeercred(fd, &ucred);
4844 if (r < 0)
4845 return log_error_errno(r, "Failed to determine peer of udev control socket: %m");
4846
4847 xsprintf(udev_path, "/proc/" PID_FMT "/ns/net", ucred.pid);
4848 r = readlink_malloc(udev_path, &udev_ns);
4849 if (r < 0)
4850 return log_error_errno(r, "Failed to read network namespace of udev: %m");
4851
4852 r = readlink_malloc("/proc/self/ns/net", &our_ns);
4853 if (r < 0)
4854 return log_error_errno(r, "Failed to read our own network namespace: %m");
4855
4856 if (!streq(our_ns, udev_ns))
4857 return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP),
4858 "Sorry, but --image= is only supported in the main network namespace, since we need access to udev/AF_NETLINK.");
4859 return 0;
4860 }
4861
4862 static int run(int argc, char *argv[]) {
4863 bool secondary = false, remove_directory = false, remove_image = false,
4864 veth_created = false, remove_tmprootdir = false;
4865 _cleanup_close_ int master = -1;
4866 _cleanup_fdset_free_ FDSet *fds = NULL;
4867 int r, n_fd_passed, ret = EXIT_SUCCESS;
4868 char veth_name[IFNAMSIZ] = "";
4869 union in_addr_union exposed = {};
4870 _cleanup_(release_lock_file) LockFile tree_global_lock = LOCK_FILE_INIT, tree_local_lock = LOCK_FILE_INIT;
4871 char tmprootdir[] = "/tmp/nspawn-root-XXXXXX";
4872 _cleanup_(loop_device_unrefp) LoopDevice *loop = NULL;
4873 _cleanup_(decrypted_image_unrefp) DecryptedImage *decrypted_image = NULL;
4874 _cleanup_(dissected_image_unrefp) DissectedImage *dissected_image = NULL;
4875 pid_t pid = 0;
4876
4877 log_parse_environment();
4878 log_open();
4879
4880 r = parse_argv(argc, argv);
4881 if (r <= 0)
4882 goto finish;
4883
4884 r = must_be_root();
4885 if (r < 0)
4886 goto finish;
4887
4888 r = cant_be_in_netns();
4889 if (r < 0)
4890 goto finish;
4891
4892 r = initialize_rlimits();
4893 if (r < 0)
4894 goto finish;
4895
4896 r = load_oci_bundle();
4897 if (r < 0)
4898 goto finish;
4899
4900 r = determine_names();
4901 if (r < 0)
4902 goto finish;
4903
4904 r = load_settings();
4905 if (r < 0)
4906 goto finish;
4907
4908 r = cg_unified();
4909 if (r < 0) {
4910 log_error_errno(r, "Failed to determine whether the unified cgroups hierarchy is used: %m");
4911 goto finish;
4912 }
4913
4914 r = verify_arguments();
4915 if (r < 0)
4916 goto finish;
4917
4918 /* Reapply environment settings. */
4919 (void) detect_unified_cgroup_hierarchy_from_environment();
4920
4921 /* Ignore SIGPIPE here, because we use splice() on the ptyfwd stuff and that will generate SIGPIPE if
4922 * the result is closed. Note that the container payload child will reset signal mask+handler anyway,
4923 * so just turning this off here means we only turn it off in nspawn itself, not any children. */
4924 (void) ignore_signals(SIGPIPE, -1);
4925
4926 n_fd_passed = sd_listen_fds(false);
4927 if (n_fd_passed > 0) {
4928 r = fdset_new_listen_fds(&fds, false);
4929 if (r < 0) {
4930 log_error_errno(r, "Failed to collect file descriptors: %m");
4931 goto finish;
4932 }
4933 }
4934
4935 /* The "default" umask. This is appropriate for most file and directory
4936 * operations performed by nspawn, and is the umask that will be used for
4937 * the child. Functions like copy_devnodes() change the umask temporarily. */
4938 umask(0022);
4939
4940 if (arg_directory) {
4941 assert(!arg_image);
4942
4943 /* Safety precaution: let's not allow running images from the live host OS image, as long as
4944 * /var from the host will propagate into container dynamically (because bad things happen if
4945 * two systems write to the same /var). Let's allow it for the special cases where /var is
4946 * either copied (i.e. --ephemeral) or replaced (i.e. --volatile=yes|state). */
4947 if (path_equal(arg_directory, "/") && !(arg_ephemeral || IN_SET(arg_volatile_mode, VOLATILE_YES, VOLATILE_STATE))) {
4948 log_error("Spawning container on root directory is not supported. Consider using --ephemeral, --volatile=yes or --volatile=state.");
4949 r = -EINVAL;
4950 goto finish;
4951 }
4952
4953 if (arg_ephemeral) {
4954 _cleanup_free_ char *np = NULL;
4955
4956 r = chase_symlinks_and_update(&arg_directory, 0);
4957 if (r < 0)
4958 goto finish;
4959
4960 /* If the specified path is a mount point we generate the new snapshot immediately
4961 * inside it under a random name. However if the specified is not a mount point we
4962 * create the new snapshot in the parent directory, just next to it. */
4963 r = path_is_mount_point(arg_directory, NULL, 0);
4964 if (r < 0) {
4965 log_error_errno(r, "Failed to determine whether directory %s is mount point: %m", arg_directory);
4966 goto finish;
4967 }
4968 if (r > 0)
4969 r = tempfn_random_child(arg_directory, "machine.", &np);
4970 else
4971 r = tempfn_random(arg_directory, "machine.", &np);
4972 if (r < 0) {
4973 log_error_errno(r, "Failed to generate name for directory snapshot: %m");
4974 goto finish;
4975 }
4976
4977 /* We take an exclusive lock on this image, since it's our private, ephemeral copy
4978 * only owned by us and no one else. */
4979 r = image_path_lock(np, LOCK_EX|LOCK_NB, &tree_global_lock, &tree_local_lock);
4980 if (r < 0) {
4981 log_error_errno(r, "Failed to lock %s: %m", np);
4982 goto finish;
4983 }
4984
4985 {
4986 BLOCK_SIGNALS(SIGINT);
4987 r = btrfs_subvol_snapshot(arg_directory, np,
4988 (arg_read_only ? BTRFS_SNAPSHOT_READ_ONLY : 0) |
4989 BTRFS_SNAPSHOT_FALLBACK_COPY |
4990 BTRFS_SNAPSHOT_FALLBACK_DIRECTORY |
4991 BTRFS_SNAPSHOT_RECURSIVE |
4992 BTRFS_SNAPSHOT_QUOTA |
4993 BTRFS_SNAPSHOT_SIGINT);
4994 }
4995 if (r == -EINTR) {
4996 log_error_errno(r, "Interrupted while copying file system tree to %s, removed again.", np);
4997 goto finish;
4998 }
4999 if (r < 0) {
5000 log_error_errno(r, "Failed to create snapshot %s from %s: %m", np, arg_directory);
5001 goto finish;
5002 }
5003
5004 free_and_replace(arg_directory, np);
5005 remove_directory = true;
5006 } else {
5007 r = chase_symlinks_and_update(&arg_directory, arg_template ? CHASE_NONEXISTENT : 0);
5008 if (r < 0)
5009 goto finish;
5010
5011 r = image_path_lock(arg_directory, (arg_read_only ? LOCK_SH : LOCK_EX) | LOCK_NB, &tree_global_lock, &tree_local_lock);
5012 if (r == -EBUSY) {
5013 log_error_errno(r, "Directory tree %s is currently busy.", arg_directory);
5014 goto finish;
5015 }
5016 if (r < 0) {
5017 log_error_errno(r, "Failed to lock %s: %m", arg_directory);
5018 goto finish;
5019 }
5020
5021 if (arg_template) {
5022 r = chase_symlinks_and_update(&arg_template, 0);
5023 if (r < 0)
5024 goto finish;
5025
5026 {
5027 BLOCK_SIGNALS(SIGINT);
5028 r = btrfs_subvol_snapshot(arg_template, arg_directory,
5029 (arg_read_only ? BTRFS_SNAPSHOT_READ_ONLY : 0) |
5030 BTRFS_SNAPSHOT_FALLBACK_COPY |
5031 BTRFS_SNAPSHOT_FALLBACK_DIRECTORY |
5032 BTRFS_SNAPSHOT_FALLBACK_IMMUTABLE |
5033 BTRFS_SNAPSHOT_RECURSIVE |
5034 BTRFS_SNAPSHOT_QUOTA |
5035 BTRFS_SNAPSHOT_SIGINT);
5036 }
5037 if (r == -EEXIST)
5038 log_full(arg_quiet ? LOG_DEBUG : LOG_INFO,
5039 "Directory %s already exists, not populating from template %s.", arg_directory, arg_template);
5040 else if (r == -EINTR) {
5041 log_error_errno(r, "Interrupted while copying file system tree to %s, removed again.", arg_directory);
5042 goto finish;
5043 } else if (r < 0) {
5044 log_error_errno(r, "Couldn't create snapshot %s from %s: %m", arg_directory, arg_template);
5045 goto finish;
5046 } else
5047 log_full(arg_quiet ? LOG_DEBUG : LOG_INFO,
5048 "Populated %s from template %s.", arg_directory, arg_template);
5049 }
5050 }
5051
5052 if (arg_start_mode == START_BOOT) {
5053 const char *p;
5054
5055 if (arg_pivot_root_new)
5056 p = prefix_roota(arg_directory, arg_pivot_root_new);
5057 else
5058 p = arg_directory;
5059
5060 if (path_is_os_tree(p) <= 0) {
5061 log_error("Directory %s doesn't look like an OS root directory (os-release file is missing). Refusing.", p);
5062 r = -EINVAL;
5063 goto finish;
5064 }
5065 } else {
5066 const char *p, *q;
5067
5068 if (arg_pivot_root_new)
5069 p = prefix_roota(arg_directory, arg_pivot_root_new);
5070 else
5071 p = arg_directory;
5072
5073 q = strjoina(p, "/usr/");
5074
5075 if (laccess(q, F_OK) < 0) {
5076 log_error("Directory %s doesn't look like it has an OS tree. Refusing.", p);
5077 r = -EINVAL;
5078 goto finish;
5079 }
5080 }
5081
5082 } else {
5083 assert(arg_image);
5084 assert(!arg_template);
5085
5086 r = chase_symlinks_and_update(&arg_image, 0);
5087 if (r < 0)
5088 goto finish;
5089
5090 if (arg_ephemeral) {
5091 _cleanup_free_ char *np = NULL;
5092
5093 r = tempfn_random(arg_image, "machine.", &np);
5094 if (r < 0) {
5095 log_error_errno(r, "Failed to generate name for image snapshot: %m");
5096 goto finish;
5097 }
5098
5099 /* Always take an exclusive lock on our own ephemeral copy. */
5100 r = image_path_lock(np, LOCK_EX|LOCK_NB, &tree_global_lock, &tree_local_lock);
5101 if (r < 0) {
5102 r = log_error_errno(r, "Failed to create image lock: %m");
5103 goto finish;
5104 }
5105
5106 {
5107 BLOCK_SIGNALS(SIGINT);
5108 r = copy_file(arg_image, np, O_EXCL, arg_read_only ? 0400 : 0600, FS_NOCOW_FL, FS_NOCOW_FL, COPY_REFLINK|COPY_CRTIME|COPY_SIGINT);
5109 }
5110 if (r == -EINTR) {
5111 log_error_errno(r, "Interrupted while copying image file to %s, removed again.", np);
5112 goto finish;
5113 }
5114 if (r < 0) {
5115 r = log_error_errno(r, "Failed to copy image file: %m");
5116 goto finish;
5117 }
5118
5119 free_and_replace(arg_image, np);
5120 remove_image = true;
5121 } else {
5122 r = image_path_lock(arg_image, (arg_read_only ? LOCK_SH : LOCK_EX) | LOCK_NB, &tree_global_lock, &tree_local_lock);
5123 if (r == -EBUSY) {
5124 r = log_error_errno(r, "Disk image %s is currently busy.", arg_image);
5125 goto finish;
5126 }
5127 if (r < 0) {
5128 r = log_error_errno(r, "Failed to create image lock: %m");
5129 goto finish;
5130 }
5131
5132 if (!arg_root_hash) {
5133 r = root_hash_load(arg_image, &arg_root_hash, &arg_root_hash_size);
5134 if (r < 0) {
5135 log_error_errno(r, "Failed to load root hash file for %s: %m", arg_image);
5136 goto finish;
5137 }
5138 }
5139 }
5140
5141 if (!mkdtemp(tmprootdir)) {
5142 r = log_error_errno(errno, "Failed to create temporary directory: %m");
5143 goto finish;
5144 }
5145
5146 remove_tmprootdir = true;
5147
5148 arg_directory = strdup(tmprootdir);
5149 if (!arg_directory) {
5150 r = log_oom();
5151 goto finish;
5152 }
5153
5154 r = loop_device_make_by_path(arg_image, arg_read_only ? O_RDONLY : O_RDWR, LO_FLAGS_PARTSCAN, &loop);
5155 if (r < 0) {
5156 log_error_errno(r, "Failed to set up loopback block device: %m");
5157 goto finish;
5158 }
5159
5160 r = dissect_image_and_warn(
5161 loop->fd,
5162 arg_image,
5163 arg_root_hash, arg_root_hash_size,
5164 DISSECT_IMAGE_REQUIRE_ROOT|DISSECT_IMAGE_RELAX_VAR_CHECK,
5165 &dissected_image);
5166 if (r == -ENOPKG) {
5167 /* dissected_image_and_warn() already printed a brief error message. Extend on that with more details */
5168 log_notice("Note that the disk image needs to\n"
5169 " a) either contain only a single MBR partition of type 0x83 that is marked bootable\n"
5170 " b) or contain a single GPT partition of type 0FC63DAF-8483-4772-8E79-3D69D8477DE4\n"
5171 " c) or follow https://systemd.io/DISCOVERABLE_PARTITIONS\n"
5172 " d) or contain a file system without a partition table\n"
5173 "in order to be bootable with systemd-nspawn.");
5174 goto finish;
5175 }
5176 if (r < 0)
5177 goto finish;
5178
5179 if (!arg_root_hash && dissected_image->can_verity)
5180 log_notice("Note: image %s contains verity information, but no root hash specified! Proceeding without integrity checking.", arg_image);
5181
5182 r = dissected_image_decrypt_interactively(dissected_image, NULL, arg_root_hash, arg_root_hash_size, 0, &decrypted_image);
5183 if (r < 0)
5184 goto finish;
5185
5186 /* Now that we mounted the image, let's try to remove it again, if it is ephemeral */
5187 if (remove_image && unlink(arg_image) >= 0)
5188 remove_image = false;
5189 }
5190
5191 r = custom_mount_prepare_all(arg_directory, arg_custom_mounts, arg_n_custom_mounts);
5192 if (r < 0)
5193 goto finish;
5194
5195 if (arg_console_mode < 0)
5196 arg_console_mode =
5197 isatty(STDIN_FILENO) > 0 &&
5198 isatty(STDOUT_FILENO) > 0 ? CONSOLE_INTERACTIVE : CONSOLE_READ_ONLY;
5199
5200 if (arg_console_mode == CONSOLE_PIPE) /* if we pass STDERR on to the container, don't add our own logs into it too */
5201 arg_quiet = true;
5202
5203 if (!arg_quiet)
5204 log_info("Spawning container %s on %s.\nPress ^] three times within 1s to kill container.",
5205 arg_machine, arg_image ?: arg_directory);
5206
5207 assert_se(sigprocmask_many(SIG_BLOCK, NULL, SIGCHLD, SIGWINCH, SIGTERM, SIGINT, -1) >= 0);
5208
5209 if (prctl(PR_SET_CHILD_SUBREAPER, 1, 0, 0, 0) < 0) {
5210 r = log_error_errno(errno, "Failed to become subreaper: %m");
5211 goto finish;
5212 }
5213
5214 for (;;) {
5215 r = run_container(dissected_image,
5216 secondary,
5217 fds,
5218 veth_name, &veth_created,
5219 &exposed, &master,
5220 &pid, &ret);
5221 if (r <= 0)
5222 break;
5223 }
5224
5225 finish:
5226 (void) sd_notify(false,
5227 r == 0 && ret == EXIT_FORCE_RESTART ? "STOPPING=1\nSTATUS=Restarting..." :
5228 "STOPPING=1\nSTATUS=Terminating...");
5229
5230 if (pid > 0)
5231 (void) kill(pid, SIGKILL);
5232
5233 /* Try to flush whatever is still queued in the pty */
5234 if (master >= 0) {
5235 (void) copy_bytes(master, STDOUT_FILENO, (uint64_t) -1, 0);
5236 master = safe_close(master);
5237 }
5238
5239 if (pid > 0)
5240 (void) wait_for_terminate(pid, NULL);
5241
5242 pager_close();
5243
5244 if (remove_directory && arg_directory) {
5245 int k;
5246
5247 k = rm_rf(arg_directory, REMOVE_ROOT|REMOVE_PHYSICAL|REMOVE_SUBVOLUME);
5248 if (k < 0)
5249 log_warning_errno(k, "Cannot remove '%s', ignoring: %m", arg_directory);
5250 }
5251
5252 if (remove_image && arg_image) {
5253 if (unlink(arg_image) < 0)
5254 log_warning_errno(errno, "Can't remove image file '%s', ignoring: %m", arg_image);
5255 }
5256
5257 if (remove_tmprootdir) {
5258 if (rmdir(tmprootdir) < 0)
5259 log_debug_errno(errno, "Can't remove temporary root directory '%s', ignoring: %m", tmprootdir);
5260 }
5261
5262 if (arg_machine) {
5263 const char *p;
5264
5265 p = strjoina("/run/systemd/nspawn/propagate/", arg_machine);
5266 (void) rm_rf(p, REMOVE_ROOT);
5267 }
5268
5269 expose_port_flush(arg_expose_ports, &exposed);
5270
5271 if (veth_created)
5272 (void) remove_veth_links(veth_name, arg_network_veth_extra);
5273 (void) remove_bridge(arg_network_zone);
5274
5275 custom_mount_free_all(arg_custom_mounts, arg_n_custom_mounts);
5276 expose_port_free_all(arg_expose_ports);
5277 rlimit_free_all(arg_rlimit);
5278 device_node_array_free(arg_extra_nodes, arg_n_extra_nodes);
5279
5280 if (r < 0)
5281 return r;
5282
5283 return ret;
5284 }
5285
5286 DEFINE_MAIN_FUNCTION_WITH_POSITIVE_FAILURE(run);
Unnamed repository; edit this file 'description' to name the repository.