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1 /* SPDX-License-Identifier: LGPL-2.1+ */
2 /***
3 This file is part of systemd.
4
5 Copyright 2010 Lennart Poettering
6
7 systemd is free software; you can redistribute it and/or modify it
8 under the terms of the GNU Lesser General Public License as published by
9 the Free Software Foundation; either version 2.1 of the License, or
10 (at your option) any later version.
11
12 systemd is distributed in the hope that it will be useful, but
13 WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 Lesser General Public License for more details.
16
17 You should have received a copy of the GNU Lesser General Public License
18 along with systemd; If not, see <http://www.gnu.org/licenses/>.
19 ***/
20
21 #if HAVE_BLKID
22 #include <blkid.h>
23 #endif
24 #include <errno.h>
25 #include <getopt.h>
26 #include <grp.h>
27 #include <linux/loop.h>
28 #include <pwd.h>
29 #include <sched.h>
30 #if HAVE_SELINUX
31 #include <selinux/selinux.h>
32 #endif
33 #include <signal.h>
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <string.h>
37 #include <sys/file.h>
38 #include <sys/mount.h>
39 #include <sys/personality.h>
40 #include <sys/prctl.h>
41 #include <sys/types.h>
42 #include <sys/wait.h>
43 #include <unistd.h>
44
45 #include "sd-bus.h"
46 #include "sd-daemon.h"
47 #include "sd-id128.h"
48
49 #include "alloc-util.h"
50 #include "barrier.h"
51 #include "base-filesystem.h"
52 #include "blkid-util.h"
53 #include "btrfs-util.h"
54 #include "bus-util.h"
55 #include "cap-list.h"
56 #include "capability-util.h"
57 #include "cgroup-util.h"
58 #include "copy.h"
59 #include "dev-setup.h"
60 #include "dissect-image.h"
61 #include "env-util.h"
62 #include "fd-util.h"
63 #include "fdset.h"
64 #include "fileio.h"
65 #include "format-util.h"
66 #include "fs-util.h"
67 #include "gpt.h"
68 #include "hexdecoct.h"
69 #include "hostname-util.h"
70 #include "id128-util.h"
71 #include "log.h"
72 #include "loop-util.h"
73 #include "loopback-setup.h"
74 #include "machine-image.h"
75 #include "macro.h"
76 #include "missing.h"
77 #include "mkdir.h"
78 #include "mount-util.h"
79 #include "netlink-util.h"
80 #include "nspawn-cgroup.h"
81 #include "nspawn-def.h"
82 #include "nspawn-expose-ports.h"
83 #include "nspawn-mount.h"
84 #include "nspawn-network.h"
85 #include "nspawn-patch-uid.h"
86 #include "nspawn-register.h"
87 #include "nspawn-seccomp.h"
88 #include "nspawn-settings.h"
89 #include "nspawn-setuid.h"
90 #include "nspawn-stub-pid1.h"
91 #include "parse-util.h"
92 #include "path-util.h"
93 #include "process-util.h"
94 #include "ptyfwd.h"
95 #include "random-util.h"
96 #include "raw-clone.h"
97 #include "rm-rf.h"
98 #include "selinux-util.h"
99 #include "signal-util.h"
100 #include "socket-util.h"
101 #include "stat-util.h"
102 #include "stdio-util.h"
103 #include "string-util.h"
104 #include "strv.h"
105 #include "terminal-util.h"
106 #include "udev-util.h"
107 #include "umask-util.h"
108 #include "user-util.h"
109 #include "util.h"
110
111 #if HAVE_SPLIT_USR
112 #define STATIC_RESOLV_CONF "/lib/systemd/resolv.conf"
113 #else
114 #define STATIC_RESOLV_CONF "/usr/lib/systemd/resolv.conf"
115 #endif
116
117 /* nspawn is listening on the socket at the path in the constant nspawn_notify_socket_path
118 * nspawn_notify_socket_path is relative to the container
119 * the init process in the container pid can send messages to nspawn following the sd_notify(3) protocol */
120 #define NSPAWN_NOTIFY_SOCKET_PATH "/run/systemd/nspawn/notify"
121
122 #define EXIT_FORCE_RESTART 133
123
124 typedef enum ContainerStatus {
125 CONTAINER_TERMINATED,
126 CONTAINER_REBOOTED
127 } ContainerStatus;
128
129 typedef enum LinkJournal {
130 LINK_NO,
131 LINK_AUTO,
132 LINK_HOST,
133 LINK_GUEST
134 } LinkJournal;
135
136 static char *arg_directory = NULL;
137 static char *arg_template = NULL;
138 static char *arg_chdir = NULL;
139 static char *arg_pivot_root_new = NULL;
140 static char *arg_pivot_root_old = NULL;
141 static char *arg_user = NULL;
142 static sd_id128_t arg_uuid = {};
143 static char *arg_machine = NULL;
144 static const char *arg_selinux_context = NULL;
145 static const char *arg_selinux_apifs_context = NULL;
146 static const char *arg_slice = NULL;
147 static bool arg_private_network = false;
148 static bool arg_read_only = false;
149 static StartMode arg_start_mode = START_PID1;
150 static bool arg_ephemeral = false;
151 static LinkJournal arg_link_journal = LINK_AUTO;
152 static bool arg_link_journal_try = false;
153 static uint64_t arg_caps_retain =
154 (1ULL << CAP_AUDIT_CONTROL) |
155 (1ULL << CAP_AUDIT_WRITE) |
156 (1ULL << CAP_CHOWN) |
157 (1ULL << CAP_DAC_OVERRIDE) |
158 (1ULL << CAP_DAC_READ_SEARCH) |
159 (1ULL << CAP_FOWNER) |
160 (1ULL << CAP_FSETID) |
161 (1ULL << CAP_IPC_OWNER) |
162 (1ULL << CAP_KILL) |
163 (1ULL << CAP_LEASE) |
164 (1ULL << CAP_LINUX_IMMUTABLE) |
165 (1ULL << CAP_MKNOD) |
166 (1ULL << CAP_NET_BIND_SERVICE) |
167 (1ULL << CAP_NET_BROADCAST) |
168 (1ULL << CAP_NET_RAW) |
169 (1ULL << CAP_SETFCAP) |
170 (1ULL << CAP_SETGID) |
171 (1ULL << CAP_SETPCAP) |
172 (1ULL << CAP_SETUID) |
173 (1ULL << CAP_SYS_ADMIN) |
174 (1ULL << CAP_SYS_BOOT) |
175 (1ULL << CAP_SYS_CHROOT) |
176 (1ULL << CAP_SYS_NICE) |
177 (1ULL << CAP_SYS_PTRACE) |
178 (1ULL << CAP_SYS_RESOURCE) |
179 (1ULL << CAP_SYS_TTY_CONFIG);
180 static CustomMount *arg_custom_mounts = NULL;
181 static unsigned arg_n_custom_mounts = 0;
182 static char **arg_setenv = NULL;
183 static bool arg_quiet = false;
184 static bool arg_register = true;
185 static bool arg_keep_unit = false;
186 static char **arg_network_interfaces = NULL;
187 static char **arg_network_macvlan = NULL;
188 static char **arg_network_ipvlan = NULL;
189 static bool arg_network_veth = false;
190 static char **arg_network_veth_extra = NULL;
191 static char *arg_network_bridge = NULL;
192 static char *arg_network_zone = NULL;
193 static char *arg_network_namespace_path = NULL;
194 static unsigned long arg_personality = PERSONALITY_INVALID;
195 static char *arg_image = NULL;
196 static VolatileMode arg_volatile_mode = VOLATILE_NO;
197 static ExposePort *arg_expose_ports = NULL;
198 static char **arg_property = NULL;
199 static UserNamespaceMode arg_userns_mode = USER_NAMESPACE_NO;
200 static uid_t arg_uid_shift = UID_INVALID, arg_uid_range = 0x10000U;
201 static bool arg_userns_chown = false;
202 static int arg_kill_signal = 0;
203 static CGroupUnified arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_UNKNOWN;
204 static SettingsMask arg_settings_mask = 0;
205 static int arg_settings_trusted = -1;
206 static char **arg_parameters = NULL;
207 static const char *arg_container_service_name = "systemd-nspawn";
208 static bool arg_notify_ready = false;
209 static bool arg_use_cgns = true;
210 static unsigned long arg_clone_ns_flags = CLONE_NEWIPC|CLONE_NEWPID|CLONE_NEWUTS;
211 static MountSettingsMask arg_mount_settings = MOUNT_APPLY_APIVFS_RO;
212 static void *arg_root_hash = NULL;
213 static size_t arg_root_hash_size = 0;
214 static char **arg_syscall_whitelist = NULL;
215 static char **arg_syscall_blacklist = NULL;
216
217 static void help(void) {
218 printf("%s [OPTIONS...] [PATH] [ARGUMENTS...]\n\n"
219 "Spawn a minimal namespace container for debugging, testing and building.\n\n"
220 " -h --help Show this help\n"
221 " --version Print version string\n"
222 " -q --quiet Do not show status information\n"
223 " -D --directory=PATH Root directory for the container\n"
224 " --template=PATH Initialize root directory from template directory,\n"
225 " if missing\n"
226 " -x --ephemeral Run container with snapshot of root directory, and\n"
227 " remove it after exit\n"
228 " -i --image=PATH File system device or disk image for the container\n"
229 " --root-hash=HASH Specify verity root hash\n"
230 " -a --as-pid2 Maintain a stub init as PID1, invoke binary as PID2\n"
231 " -b --boot Boot up full system (i.e. invoke init)\n"
232 " --chdir=PATH Set working directory in the container\n"
233 " --pivot-root=PATH[:PATH]\n"
234 " Pivot root to given directory in the container\n"
235 " -u --user=USER Run the command under specified user or uid\n"
236 " -M --machine=NAME Set the machine name for the container\n"
237 " --uuid=UUID Set a specific machine UUID for the container\n"
238 " -S --slice=SLICE Place the container in the specified slice\n"
239 " --property=NAME=VALUE Set scope unit property\n"
240 " -U --private-users=pick Run within user namespace, autoselect UID/GID range\n"
241 " --private-users[=UIDBASE[:NUIDS]]\n"
242 " Similar, but with user configured UID/GID range\n"
243 " --private-users-chown Adjust OS tree ownership to private UID/GID range\n"
244 " --private-network Disable network in container\n"
245 " --network-interface=INTERFACE\n"
246 " Assign an existing network interface to the\n"
247 " container\n"
248 " --network-macvlan=INTERFACE\n"
249 " Create a macvlan network interface based on an\n"
250 " existing network interface to the container\n"
251 " --network-ipvlan=INTERFACE\n"
252 " Create a ipvlan network interface based on an\n"
253 " existing network interface to the container\n"
254 " -n --network-veth Add a virtual Ethernet connection between host\n"
255 " and container\n"
256 " --network-veth-extra=HOSTIF[:CONTAINERIF]\n"
257 " Add an additional virtual Ethernet link between\n"
258 " host and container\n"
259 " --network-bridge=INTERFACE\n"
260 " Add a virtual Ethernet connection to the container\n"
261 " and attach it to an existing bridge on the host\n"
262 " --network-zone=NAME Similar, but attach the new interface to an\n"
263 " an automatically managed bridge interface\n"
264 " --network-namespace-path=PATH\n"
265 " Set network namespace to the one represented by\n"
266 " the specified kernel namespace file node\n"
267 " -p --port=[PROTOCOL:]HOSTPORT[:CONTAINERPORT]\n"
268 " Expose a container IP port on the host\n"
269 " -Z --selinux-context=SECLABEL\n"
270 " Set the SELinux security context to be used by\n"
271 " processes in the container\n"
272 " -L --selinux-apifs-context=SECLABEL\n"
273 " Set the SELinux security context to be used by\n"
274 " API/tmpfs file systems in the container\n"
275 " --capability=CAP In addition to the default, retain specified\n"
276 " capability\n"
277 " --drop-capability=CAP Drop the specified capability from the default set\n"
278 " --system-call-filter=LIST|~LIST\n"
279 " Permit/prohibit specific system calls\n"
280 " --kill-signal=SIGNAL Select signal to use for shutting down PID 1\n"
281 " --link-journal=MODE Link up guest journal, one of no, auto, guest, \n"
282 " host, try-guest, try-host\n"
283 " -j Equivalent to --link-journal=try-guest\n"
284 " --read-only Mount the root directory read-only\n"
285 " --bind=PATH[:PATH[:OPTIONS]]\n"
286 " Bind mount a file or directory from the host into\n"
287 " the container\n"
288 " --bind-ro=PATH[:PATH[:OPTIONS]\n"
289 " Similar, but creates a read-only bind mount\n"
290 " --tmpfs=PATH:[OPTIONS] Mount an empty tmpfs to the specified directory\n"
291 " --overlay=PATH[:PATH...]:PATH\n"
292 " Create an overlay mount from the host to \n"
293 " the container\n"
294 " --overlay-ro=PATH[:PATH...]:PATH\n"
295 " Similar, but creates a read-only overlay mount\n"
296 " -E --setenv=NAME=VALUE Pass an environment variable to PID 1\n"
297 " --register=BOOLEAN Register container as machine\n"
298 " --keep-unit Do not register a scope for the machine, reuse\n"
299 " the service unit nspawn is running in\n"
300 " --volatile[=MODE] Run the system in volatile mode\n"
301 " --settings=BOOLEAN Load additional settings from .nspawn file\n"
302 " --notify-ready=BOOLEAN Receive notifications from the child init process\n"
303 , program_invocation_short_name);
304 }
305
306 static int custom_mount_check_all(void) {
307 unsigned i;
308
309 for (i = 0; i < arg_n_custom_mounts; i++) {
310 CustomMount *m = &arg_custom_mounts[i];
311
312 if (path_equal(m->destination, "/") && arg_userns_mode != USER_NAMESPACE_NO) {
313
314 if (arg_userns_chown) {
315 log_error("--private-users-chown may not be combined with custom root mounts.");
316 return -EINVAL;
317 } else if (arg_uid_shift == UID_INVALID) {
318 log_error("--private-users with automatic UID shift may not be combined with custom root mounts.");
319 return -EINVAL;
320 }
321 }
322 }
323
324 return 0;
325 }
326
327 static int detect_unified_cgroup_hierarchy_from_environment(void) {
328 const char *e;
329 int r;
330
331 /* Allow the user to control whether the unified hierarchy is used */
332 e = getenv("UNIFIED_CGROUP_HIERARCHY");
333 if (e) {
334 r = parse_boolean(e);
335 if (r < 0)
336 return log_error_errno(r, "Failed to parse $UNIFIED_CGROUP_HIERARCHY.");
337 if (r > 0)
338 arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_ALL;
339 else
340 arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_NONE;
341 }
342
343 return 0;
344 }
345
346 static int detect_unified_cgroup_hierarchy_from_image(const char *directory) {
347 int r;
348
349 /* Let's inherit the mode to use from the host system, but let's take into consideration what systemd in the
350 * image actually supports. */
351 r = cg_all_unified();
352 if (r < 0)
353 return log_error_errno(r, "Failed to determine whether we are in all unified mode.");
354 if (r > 0) {
355 /* Unified cgroup hierarchy support was added in 230. Unfortunately the detection
356 * routine only detects 231, so we'll have a false negative here for 230. */
357 r = systemd_installation_has_version(directory, 230);
358 if (r < 0)
359 return log_error_errno(r, "Failed to determine systemd version in container: %m");
360 if (r > 0)
361 arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_ALL;
362 else
363 arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_NONE;
364 } else if (cg_unified_controller(SYSTEMD_CGROUP_CONTROLLER) > 0) {
365 /* Mixed cgroup hierarchy support was added in 233 */
366 r = systemd_installation_has_version(directory, 233);
367 if (r < 0)
368 return log_error_errno(r, "Failed to determine systemd version in container: %m");
369 if (r > 0)
370 arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_SYSTEMD;
371 else
372 arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_NONE;
373 } else
374 arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_NONE;
375
376 log_debug("Using %s hierarchy for container.",
377 arg_unified_cgroup_hierarchy == CGROUP_UNIFIED_NONE ? "legacy" :
378 arg_unified_cgroup_hierarchy == CGROUP_UNIFIED_SYSTEMD ? "hybrid" : "unified");
379
380 return 0;
381 }
382
383 static void parse_share_ns_env(const char *name, unsigned long ns_flag) {
384 int r;
385
386 r = getenv_bool(name);
387 if (r == -ENXIO)
388 return;
389 if (r < 0)
390 log_warning_errno(r, "Failed to parse %s from environment, defaulting to false.", name);
391 arg_clone_ns_flags = (arg_clone_ns_flags & ~ns_flag) | (r > 0 ? 0 : ns_flag);
392 }
393
394 static void parse_mount_settings_env(void) {
395 int r;
396 const char *e;
397
398 e = getenv("SYSTEMD_NSPAWN_API_VFS_WRITABLE");
399 if (!e)
400 return;
401
402 if (streq(e, "network")) {
403 arg_mount_settings |= MOUNT_APPLY_APIVFS_RO|MOUNT_APPLY_APIVFS_NETNS;
404 return;
405 }
406
407 r = parse_boolean(e);
408 if (r < 0) {
409 log_warning_errno(r, "Failed to parse SYSTEMD_NSPAWN_API_VFS_WRITABLE from environment, ignoring.");
410 return;
411 }
412
413 SET_FLAG(arg_mount_settings, MOUNT_APPLY_APIVFS_RO, r == 0);
414 SET_FLAG(arg_mount_settings, MOUNT_APPLY_APIVFS_NETNS, false);
415 }
416
417 static int parse_argv(int argc, char *argv[]) {
418
419 enum {
420 ARG_VERSION = 0x100,
421 ARG_PRIVATE_NETWORK,
422 ARG_UUID,
423 ARG_READ_ONLY,
424 ARG_CAPABILITY,
425 ARG_DROP_CAPABILITY,
426 ARG_LINK_JOURNAL,
427 ARG_BIND,
428 ARG_BIND_RO,
429 ARG_TMPFS,
430 ARG_OVERLAY,
431 ARG_OVERLAY_RO,
432 ARG_SHARE_SYSTEM,
433 ARG_REGISTER,
434 ARG_KEEP_UNIT,
435 ARG_NETWORK_INTERFACE,
436 ARG_NETWORK_MACVLAN,
437 ARG_NETWORK_IPVLAN,
438 ARG_NETWORK_BRIDGE,
439 ARG_NETWORK_ZONE,
440 ARG_NETWORK_VETH_EXTRA,
441 ARG_NETWORK_NAMESPACE_PATH,
442 ARG_PERSONALITY,
443 ARG_VOLATILE,
444 ARG_TEMPLATE,
445 ARG_PROPERTY,
446 ARG_PRIVATE_USERS,
447 ARG_KILL_SIGNAL,
448 ARG_SETTINGS,
449 ARG_CHDIR,
450 ARG_PIVOT_ROOT,
451 ARG_PRIVATE_USERS_CHOWN,
452 ARG_NOTIFY_READY,
453 ARG_ROOT_HASH,
454 ARG_SYSTEM_CALL_FILTER,
455 };
456
457 static const struct option options[] = {
458 { "help", no_argument, NULL, 'h' },
459 { "version", no_argument, NULL, ARG_VERSION },
460 { "directory", required_argument, NULL, 'D' },
461 { "template", required_argument, NULL, ARG_TEMPLATE },
462 { "ephemeral", no_argument, NULL, 'x' },
463 { "user", required_argument, NULL, 'u' },
464 { "private-network", no_argument, NULL, ARG_PRIVATE_NETWORK },
465 { "as-pid2", no_argument, NULL, 'a' },
466 { "boot", no_argument, NULL, 'b' },
467 { "uuid", required_argument, NULL, ARG_UUID },
468 { "read-only", no_argument, NULL, ARG_READ_ONLY },
469 { "capability", required_argument, NULL, ARG_CAPABILITY },
470 { "drop-capability", required_argument, NULL, ARG_DROP_CAPABILITY },
471 { "link-journal", required_argument, NULL, ARG_LINK_JOURNAL },
472 { "bind", required_argument, NULL, ARG_BIND },
473 { "bind-ro", required_argument, NULL, ARG_BIND_RO },
474 { "tmpfs", required_argument, NULL, ARG_TMPFS },
475 { "overlay", required_argument, NULL, ARG_OVERLAY },
476 { "overlay-ro", required_argument, NULL, ARG_OVERLAY_RO },
477 { "machine", required_argument, NULL, 'M' },
478 { "slice", required_argument, NULL, 'S' },
479 { "setenv", required_argument, NULL, 'E' },
480 { "selinux-context", required_argument, NULL, 'Z' },
481 { "selinux-apifs-context", required_argument, NULL, 'L' },
482 { "quiet", no_argument, NULL, 'q' },
483 { "share-system", no_argument, NULL, ARG_SHARE_SYSTEM }, /* not documented */
484 { "register", required_argument, NULL, ARG_REGISTER },
485 { "keep-unit", no_argument, NULL, ARG_KEEP_UNIT },
486 { "network-interface", required_argument, NULL, ARG_NETWORK_INTERFACE },
487 { "network-macvlan", required_argument, NULL, ARG_NETWORK_MACVLAN },
488 { "network-ipvlan", required_argument, NULL, ARG_NETWORK_IPVLAN },
489 { "network-veth", no_argument, NULL, 'n' },
490 { "network-veth-extra", required_argument, NULL, ARG_NETWORK_VETH_EXTRA },
491 { "network-bridge", required_argument, NULL, ARG_NETWORK_BRIDGE },
492 { "network-zone", required_argument, NULL, ARG_NETWORK_ZONE },
493 { "network-namespace-path", required_argument, NULL, ARG_NETWORK_NAMESPACE_PATH },
494 { "personality", required_argument, NULL, ARG_PERSONALITY },
495 { "image", required_argument, NULL, 'i' },
496 { "volatile", optional_argument, NULL, ARG_VOLATILE },
497 { "port", required_argument, NULL, 'p' },
498 { "property", required_argument, NULL, ARG_PROPERTY },
499 { "private-users", optional_argument, NULL, ARG_PRIVATE_USERS },
500 { "private-users-chown", optional_argument, NULL, ARG_PRIVATE_USERS_CHOWN },
501 { "kill-signal", required_argument, NULL, ARG_KILL_SIGNAL },
502 { "settings", required_argument, NULL, ARG_SETTINGS },
503 { "chdir", required_argument, NULL, ARG_CHDIR },
504 { "pivot-root", required_argument, NULL, ARG_PIVOT_ROOT },
505 { "notify-ready", required_argument, NULL, ARG_NOTIFY_READY },
506 { "root-hash", required_argument, NULL, ARG_ROOT_HASH },
507 { "system-call-filter", required_argument, NULL, ARG_SYSTEM_CALL_FILTER },
508 {}
509 };
510
511 int c, r;
512 const char *p, *e;
513 uint64_t plus = 0, minus = 0;
514 bool mask_all_settings = false, mask_no_settings = false;
515
516 assert(argc >= 0);
517 assert(argv);
518
519 while ((c = getopt_long(argc, argv, "+hD:u:abL:M:jS:Z:qi:xp:nUE:", options, NULL)) >= 0)
520
521 switch (c) {
522
523 case 'h':
524 help();
525 return 0;
526
527 case ARG_VERSION:
528 return version();
529
530 case 'D':
531 r = parse_path_argument_and_warn(optarg, false, &arg_directory);
532 if (r < 0)
533 return r;
534 break;
535
536 case ARG_TEMPLATE:
537 r = parse_path_argument_and_warn(optarg, false, &arg_template);
538 if (r < 0)
539 return r;
540 break;
541
542 case 'i':
543 r = parse_path_argument_and_warn(optarg, false, &arg_image);
544 if (r < 0)
545 return r;
546 break;
547
548 case 'x':
549 arg_ephemeral = true;
550 break;
551
552 case 'u':
553 r = free_and_strdup(&arg_user, optarg);
554 if (r < 0)
555 return log_oom();
556
557 arg_settings_mask |= SETTING_USER;
558 break;
559
560 case ARG_NETWORK_ZONE: {
561 char *j;
562
563 j = strappend("vz-", optarg);
564 if (!j)
565 return log_oom();
566
567 if (!ifname_valid(j)) {
568 log_error("Network zone name not valid: %s", j);
569 free(j);
570 return -EINVAL;
571 }
572
573 free(arg_network_zone);
574 arg_network_zone = j;
575
576 arg_network_veth = true;
577 arg_private_network = true;
578 arg_settings_mask |= SETTING_NETWORK;
579 break;
580 }
581
582 case ARG_NETWORK_BRIDGE:
583
584 if (!ifname_valid(optarg)) {
585 log_error("Bridge interface name not valid: %s", optarg);
586 return -EINVAL;
587 }
588
589 r = free_and_strdup(&arg_network_bridge, optarg);
590 if (r < 0)
591 return log_oom();
592
593 _fallthrough_;
594 case 'n':
595 arg_network_veth = true;
596 arg_private_network = true;
597 arg_settings_mask |= SETTING_NETWORK;
598 break;
599
600 case ARG_NETWORK_VETH_EXTRA:
601 r = veth_extra_parse(&arg_network_veth_extra, optarg);
602 if (r < 0)
603 return log_error_errno(r, "Failed to parse --network-veth-extra= parameter: %s", optarg);
604
605 arg_private_network = true;
606 arg_settings_mask |= SETTING_NETWORK;
607 break;
608
609 case ARG_NETWORK_INTERFACE:
610
611 if (!ifname_valid(optarg)) {
612 log_error("Network interface name not valid: %s", optarg);
613 return -EINVAL;
614 }
615
616 if (strv_extend(&arg_network_interfaces, optarg) < 0)
617 return log_oom();
618
619 arg_private_network = true;
620 arg_settings_mask |= SETTING_NETWORK;
621 break;
622
623 case ARG_NETWORK_MACVLAN:
624
625 if (!ifname_valid(optarg)) {
626 log_error("MACVLAN network interface name not valid: %s", optarg);
627 return -EINVAL;
628 }
629
630 if (strv_extend(&arg_network_macvlan, optarg) < 0)
631 return log_oom();
632
633 arg_private_network = true;
634 arg_settings_mask |= SETTING_NETWORK;
635 break;
636
637 case ARG_NETWORK_IPVLAN:
638
639 if (!ifname_valid(optarg)) {
640 log_error("IPVLAN network interface name not valid: %s", optarg);
641 return -EINVAL;
642 }
643
644 if (strv_extend(&arg_network_ipvlan, optarg) < 0)
645 return log_oom();
646
647 _fallthrough_;
648 case ARG_PRIVATE_NETWORK:
649 arg_private_network = true;
650 arg_settings_mask |= SETTING_NETWORK;
651 break;
652
653 case ARG_NETWORK_NAMESPACE_PATH:
654 r = parse_path_argument_and_warn(optarg, false, &arg_network_namespace_path);
655 if (r < 0)
656 return r;
657
658 break;
659
660 case 'b':
661 if (arg_start_mode == START_PID2) {
662 log_error("--boot and --as-pid2 may not be combined.");
663 return -EINVAL;
664 }
665
666 arg_start_mode = START_BOOT;
667 arg_settings_mask |= SETTING_START_MODE;
668 break;
669
670 case 'a':
671 if (arg_start_mode == START_BOOT) {
672 log_error("--boot and --as-pid2 may not be combined.");
673 return -EINVAL;
674 }
675
676 arg_start_mode = START_PID2;
677 arg_settings_mask |= SETTING_START_MODE;
678 break;
679
680 case ARG_UUID:
681 r = sd_id128_from_string(optarg, &arg_uuid);
682 if (r < 0)
683 return log_error_errno(r, "Invalid UUID: %s", optarg);
684
685 if (sd_id128_is_null(arg_uuid)) {
686 log_error("Machine UUID may not be all zeroes.");
687 return -EINVAL;
688 }
689
690 arg_settings_mask |= SETTING_MACHINE_ID;
691 break;
692
693 case 'S':
694 arg_slice = optarg;
695 break;
696
697 case 'M':
698 if (isempty(optarg))
699 arg_machine = mfree(arg_machine);
700 else {
701 if (!machine_name_is_valid(optarg)) {
702 log_error("Invalid machine name: %s", optarg);
703 return -EINVAL;
704 }
705
706 r = free_and_strdup(&arg_machine, optarg);
707 if (r < 0)
708 return log_oom();
709 }
710 break;
711
712 case 'Z':
713 arg_selinux_context = optarg;
714 break;
715
716 case 'L':
717 arg_selinux_apifs_context = optarg;
718 break;
719
720 case ARG_READ_ONLY:
721 arg_read_only = true;
722 arg_settings_mask |= SETTING_READ_ONLY;
723 break;
724
725 case ARG_CAPABILITY:
726 case ARG_DROP_CAPABILITY: {
727 p = optarg;
728 for (;;) {
729 _cleanup_free_ char *t = NULL;
730
731 r = extract_first_word(&p, &t, ",", 0);
732 if (r < 0)
733 return log_error_errno(r, "Failed to parse capability %s.", t);
734
735 if (r == 0)
736 break;
737
738 if (streq(t, "all")) {
739 if (c == ARG_CAPABILITY)
740 plus = (uint64_t) -1;
741 else
742 minus = (uint64_t) -1;
743 } else {
744 int cap;
745
746 cap = capability_from_name(t);
747 if (cap < 0) {
748 log_error("Failed to parse capability %s.", t);
749 return -EINVAL;
750 }
751
752 if (c == ARG_CAPABILITY)
753 plus |= 1ULL << (uint64_t) cap;
754 else
755 minus |= 1ULL << (uint64_t) cap;
756 }
757 }
758
759 arg_settings_mask |= SETTING_CAPABILITY;
760 break;
761 }
762
763 case 'j':
764 arg_link_journal = LINK_GUEST;
765 arg_link_journal_try = true;
766 break;
767
768 case ARG_LINK_JOURNAL:
769 if (streq(optarg, "auto")) {
770 arg_link_journal = LINK_AUTO;
771 arg_link_journal_try = false;
772 } else if (streq(optarg, "no")) {
773 arg_link_journal = LINK_NO;
774 arg_link_journal_try = false;
775 } else if (streq(optarg, "guest")) {
776 arg_link_journal = LINK_GUEST;
777 arg_link_journal_try = false;
778 } else if (streq(optarg, "host")) {
779 arg_link_journal = LINK_HOST;
780 arg_link_journal_try = false;
781 } else if (streq(optarg, "try-guest")) {
782 arg_link_journal = LINK_GUEST;
783 arg_link_journal_try = true;
784 } else if (streq(optarg, "try-host")) {
785 arg_link_journal = LINK_HOST;
786 arg_link_journal_try = true;
787 } else {
788 log_error("Failed to parse link journal mode %s", optarg);
789 return -EINVAL;
790 }
791
792 break;
793
794 case ARG_BIND:
795 case ARG_BIND_RO:
796 r = bind_mount_parse(&arg_custom_mounts, &arg_n_custom_mounts, optarg, c == ARG_BIND_RO);
797 if (r < 0)
798 return log_error_errno(r, "Failed to parse --bind(-ro)= argument %s: %m", optarg);
799
800 arg_settings_mask |= SETTING_CUSTOM_MOUNTS;
801 break;
802
803 case ARG_TMPFS:
804 r = tmpfs_mount_parse(&arg_custom_mounts, &arg_n_custom_mounts, optarg);
805 if (r < 0)
806 return log_error_errno(r, "Failed to parse --tmpfs= argument %s: %m", optarg);
807
808 arg_settings_mask |= SETTING_CUSTOM_MOUNTS;
809 break;
810
811 case ARG_OVERLAY:
812 case ARG_OVERLAY_RO:
813 r = overlay_mount_parse(&arg_custom_mounts, &arg_n_custom_mounts, optarg, c == ARG_OVERLAY_RO);
814 if (r == -EADDRNOTAVAIL)
815 return log_error_errno(r, "--overlay(-ro)= needs at least two colon-separated directories specified.");
816 if (r < 0)
817 return log_error_errno(r, "Failed to parse --overlay(-ro)= argument %s: %m", optarg);
818
819 arg_settings_mask |= SETTING_CUSTOM_MOUNTS;
820 break;
821
822 case 'E': {
823 char **n;
824
825 if (!env_assignment_is_valid(optarg)) {
826 log_error("Environment variable assignment '%s' is not valid.", optarg);
827 return -EINVAL;
828 }
829
830 n = strv_env_set(arg_setenv, optarg);
831 if (!n)
832 return log_oom();
833
834 strv_free(arg_setenv);
835 arg_setenv = n;
836
837 arg_settings_mask |= SETTING_ENVIRONMENT;
838 break;
839 }
840
841 case 'q':
842 arg_quiet = true;
843 break;
844
845 case ARG_SHARE_SYSTEM:
846 /* We don't officially support this anymore, except for compat reasons. People should use the
847 * $SYSTEMD_NSPAWN_SHARE_* environment variables instead. */
848 arg_clone_ns_flags = 0;
849 break;
850
851 case ARG_REGISTER:
852 r = parse_boolean(optarg);
853 if (r < 0) {
854 log_error("Failed to parse --register= argument: %s", optarg);
855 return r;
856 }
857
858 arg_register = r;
859 break;
860
861 case ARG_KEEP_UNIT:
862 arg_keep_unit = true;
863 break;
864
865 case ARG_PERSONALITY:
866
867 arg_personality = personality_from_string(optarg);
868 if (arg_personality == PERSONALITY_INVALID) {
869 log_error("Unknown or unsupported personality '%s'.", optarg);
870 return -EINVAL;
871 }
872
873 arg_settings_mask |= SETTING_PERSONALITY;
874 break;
875
876 case ARG_VOLATILE:
877
878 if (!optarg)
879 arg_volatile_mode = VOLATILE_YES;
880 else {
881 VolatileMode m;
882
883 m = volatile_mode_from_string(optarg);
884 if (m < 0) {
885 log_error("Failed to parse --volatile= argument: %s", optarg);
886 return -EINVAL;
887 } else
888 arg_volatile_mode = m;
889 }
890
891 arg_settings_mask |= SETTING_VOLATILE_MODE;
892 break;
893
894 case 'p':
895 r = expose_port_parse(&arg_expose_ports, optarg);
896 if (r == -EEXIST)
897 return log_error_errno(r, "Duplicate port specification: %s", optarg);
898 if (r < 0)
899 return log_error_errno(r, "Failed to parse host port %s: %m", optarg);
900
901 arg_settings_mask |= SETTING_EXPOSE_PORTS;
902 break;
903
904 case ARG_PROPERTY:
905 if (strv_extend(&arg_property, optarg) < 0)
906 return log_oom();
907
908 break;
909
910 case ARG_PRIVATE_USERS: {
911 int boolean = -1;
912
913 if (!optarg)
914 boolean = true;
915 else if (!in_charset(optarg, DIGITS))
916 /* do *not* parse numbers as booleans */
917 boolean = parse_boolean(optarg);
918
919 if (boolean == false) {
920 /* no: User namespacing off */
921 arg_userns_mode = USER_NAMESPACE_NO;
922 arg_uid_shift = UID_INVALID;
923 arg_uid_range = UINT32_C(0x10000);
924 } else if (boolean == true) {
925 /* yes: User namespacing on, UID range is read from root dir */
926 arg_userns_mode = USER_NAMESPACE_FIXED;
927 arg_uid_shift = UID_INVALID;
928 arg_uid_range = UINT32_C(0x10000);
929 } else if (streq(optarg, "pick")) {
930 /* pick: User namespacing on, UID range is picked randomly */
931 arg_userns_mode = USER_NAMESPACE_PICK;
932 arg_uid_shift = UID_INVALID;
933 arg_uid_range = UINT32_C(0x10000);
934 } else {
935 _cleanup_free_ char *buffer = NULL;
936 const char *range, *shift;
937
938 /* anything else: User namespacing on, UID range is explicitly configured */
939
940 range = strchr(optarg, ':');
941 if (range) {
942 buffer = strndup(optarg, range - optarg);
943 if (!buffer)
944 return log_oom();
945 shift = buffer;
946
947 range++;
948 r = safe_atou32(range, &arg_uid_range);
949 if (r < 0)
950 return log_error_errno(r, "Failed to parse UID range \"%s\": %m", range);
951 } else
952 shift = optarg;
953
954 r = parse_uid(shift, &arg_uid_shift);
955 if (r < 0)
956 return log_error_errno(r, "Failed to parse UID \"%s\": %m", optarg);
957
958 arg_userns_mode = USER_NAMESPACE_FIXED;
959 }
960
961 if (arg_uid_range <= 0) {
962 log_error("UID range cannot be 0.");
963 return -EINVAL;
964 }
965
966 arg_settings_mask |= SETTING_USERNS;
967 break;
968 }
969
970 case 'U':
971 if (userns_supported()) {
972 arg_userns_mode = USER_NAMESPACE_PICK;
973 arg_uid_shift = UID_INVALID;
974 arg_uid_range = UINT32_C(0x10000);
975
976 arg_settings_mask |= SETTING_USERNS;
977 }
978
979 break;
980
981 case ARG_PRIVATE_USERS_CHOWN:
982 arg_userns_chown = true;
983
984 arg_settings_mask |= SETTING_USERNS;
985 break;
986
987 case ARG_KILL_SIGNAL:
988 arg_kill_signal = signal_from_string_try_harder(optarg);
989 if (arg_kill_signal < 0) {
990 log_error("Cannot parse signal: %s", optarg);
991 return -EINVAL;
992 }
993
994 arg_settings_mask |= SETTING_KILL_SIGNAL;
995 break;
996
997 case ARG_SETTINGS:
998
999 /* no → do not read files
1000 * yes → read files, do not override cmdline, trust only subset
1001 * override → read files, override cmdline, trust only subset
1002 * trusted → read files, do not override cmdline, trust all
1003 */
1004
1005 r = parse_boolean(optarg);
1006 if (r < 0) {
1007 if (streq(optarg, "trusted")) {
1008 mask_all_settings = false;
1009 mask_no_settings = false;
1010 arg_settings_trusted = true;
1011
1012 } else if (streq(optarg, "override")) {
1013 mask_all_settings = false;
1014 mask_no_settings = true;
1015 arg_settings_trusted = -1;
1016 } else
1017 return log_error_errno(r, "Failed to parse --settings= argument: %s", optarg);
1018 } else if (r > 0) {
1019 /* yes */
1020 mask_all_settings = false;
1021 mask_no_settings = false;
1022 arg_settings_trusted = -1;
1023 } else {
1024 /* no */
1025 mask_all_settings = true;
1026 mask_no_settings = false;
1027 arg_settings_trusted = false;
1028 }
1029
1030 break;
1031
1032 case ARG_CHDIR:
1033 if (!path_is_absolute(optarg)) {
1034 log_error("Working directory %s is not an absolute path.", optarg);
1035 return -EINVAL;
1036 }
1037
1038 r = free_and_strdup(&arg_chdir, optarg);
1039 if (r < 0)
1040 return log_oom();
1041
1042 arg_settings_mask |= SETTING_WORKING_DIRECTORY;
1043 break;
1044
1045 case ARG_PIVOT_ROOT:
1046 r = pivot_root_parse(&arg_pivot_root_new, &arg_pivot_root_old, optarg);
1047 if (r < 0)
1048 return log_error_errno(r, "Failed to parse --pivot-root= argument %s: %m", optarg);
1049
1050 arg_settings_mask |= SETTING_PIVOT_ROOT;
1051 break;
1052
1053 case ARG_NOTIFY_READY:
1054 r = parse_boolean(optarg);
1055 if (r < 0) {
1056 log_error("%s is not a valid notify mode. Valid modes are: yes, no, and ready.", optarg);
1057 return -EINVAL;
1058 }
1059 arg_notify_ready = r;
1060 arg_settings_mask |= SETTING_NOTIFY_READY;
1061 break;
1062
1063 case ARG_ROOT_HASH: {
1064 void *k;
1065 size_t l;
1066
1067 r = unhexmem(optarg, strlen(optarg), &k, &l);
1068 if (r < 0)
1069 return log_error_errno(r, "Failed to parse root hash: %s", optarg);
1070 if (l < sizeof(sd_id128_t)) {
1071 log_error("Root hash must be at least 128bit long: %s", optarg);
1072 free(k);
1073 return -EINVAL;
1074 }
1075
1076 free(arg_root_hash);
1077 arg_root_hash = k;
1078 arg_root_hash_size = l;
1079 break;
1080 }
1081
1082 case ARG_SYSTEM_CALL_FILTER: {
1083 bool negative;
1084 const char *items;
1085
1086 negative = optarg[0] == '~';
1087 items = negative ? optarg + 1 : optarg;
1088
1089 for (;;) {
1090 _cleanup_free_ char *word = NULL;
1091
1092 r = extract_first_word(&items, &word, NULL, 0);
1093 if (r == 0)
1094 break;
1095 if (r == -ENOMEM)
1096 return log_oom();
1097 if (r < 0)
1098 return log_error_errno(r, "Failed to parse system call filter: %m");
1099
1100 if (negative)
1101 r = strv_extend(&arg_syscall_blacklist, word);
1102 else
1103 r = strv_extend(&arg_syscall_whitelist, word);
1104 if (r < 0)
1105 return log_oom();
1106 }
1107
1108 arg_settings_mask |= SETTING_SYSCALL_FILTER;
1109 break;
1110 }
1111
1112 case '?':
1113 return -EINVAL;
1114
1115 default:
1116 assert_not_reached("Unhandled option");
1117 }
1118
1119 /* If --network-namespace-path is given with any other network-related option,
1120 * we need to error out, to avoid conflicts between different network options. */
1121 if (arg_network_namespace_path &&
1122 (arg_network_interfaces || arg_network_macvlan ||
1123 arg_network_ipvlan || arg_network_veth_extra ||
1124 arg_network_bridge || arg_network_zone ||
1125 arg_network_veth || arg_private_network)) {
1126 log_error("--network-namespace-path cannot be combined with other network options.");
1127 return -EINVAL;
1128 }
1129
1130 parse_share_ns_env("SYSTEMD_NSPAWN_SHARE_NS_IPC", CLONE_NEWIPC);
1131 parse_share_ns_env("SYSTEMD_NSPAWN_SHARE_NS_PID", CLONE_NEWPID);
1132 parse_share_ns_env("SYSTEMD_NSPAWN_SHARE_NS_UTS", CLONE_NEWUTS);
1133 parse_share_ns_env("SYSTEMD_NSPAWN_SHARE_SYSTEM", CLONE_NEWIPC|CLONE_NEWPID|CLONE_NEWUTS);
1134
1135 if (arg_userns_mode != USER_NAMESPACE_NO)
1136 arg_mount_settings |= MOUNT_USE_USERNS;
1137
1138 if (arg_private_network)
1139 arg_mount_settings |= MOUNT_APPLY_APIVFS_NETNS;
1140
1141 parse_mount_settings_env();
1142
1143 if (!(arg_clone_ns_flags & CLONE_NEWPID) ||
1144 !(arg_clone_ns_flags & CLONE_NEWUTS)) {
1145 arg_register = false;
1146 if (arg_start_mode != START_PID1) {
1147 log_error("--boot cannot be used without namespacing.");
1148 return -EINVAL;
1149 }
1150 }
1151
1152 if (arg_userns_mode == USER_NAMESPACE_PICK)
1153 arg_userns_chown = true;
1154
1155 if (arg_keep_unit && arg_register && cg_pid_get_owner_uid(0, NULL) >= 0) {
1156 /* Save the user from accidentally registering either user-$SESSION.scope or user@.service.
1157 * The latter is not technically a user session, but we don't need to labour the point. */
1158 log_error("--keep-unit --register=yes may not be used when invoked from a user session.");
1159 return -EINVAL;
1160 }
1161
1162 if (arg_directory && arg_image) {
1163 log_error("--directory= and --image= may not be combined.");
1164 return -EINVAL;
1165 }
1166
1167 if (arg_template && arg_image) {
1168 log_error("--template= and --image= may not be combined.");
1169 return -EINVAL;
1170 }
1171
1172 if (arg_ephemeral && arg_template && !arg_directory) {
1173 /* User asked for ephemeral execution but specified --template= instead of --directory=. Semantically
1174 * such an invocation makes some sense, see https://github.com/systemd/systemd/issues/3667. Let's
1175 * accept this here, and silently make "--ephemeral --template=" equivalent to "--ephemeral
1176 * --directory=". */
1177
1178 arg_directory = TAKE_PTR(arg_template);
1179 }
1180
1181 if (arg_template && !(arg_directory || arg_machine)) {
1182 log_error("--template= needs --directory= or --machine=.");
1183 return -EINVAL;
1184 }
1185
1186 if (arg_ephemeral && arg_template) {
1187 log_error("--ephemeral and --template= may not be combined.");
1188 return -EINVAL;
1189 }
1190
1191 if (arg_ephemeral && !IN_SET(arg_link_journal, LINK_NO, LINK_AUTO)) {
1192 log_error("--ephemeral and --link-journal= may not be combined.");
1193 return -EINVAL;
1194 }
1195
1196 if (arg_userns_mode != USER_NAMESPACE_NO && !userns_supported()) {
1197 log_error("--private-users= is not supported, kernel compiled without user namespace support.");
1198 return -EOPNOTSUPP;
1199 }
1200
1201 if (arg_userns_chown && arg_read_only) {
1202 log_error("--read-only and --private-users-chown may not be combined.");
1203 return -EINVAL;
1204 }
1205
1206 if (arg_network_bridge && arg_network_zone) {
1207 log_error("--network-bridge= and --network-zone= may not be combined.");
1208 return -EINVAL;
1209 }
1210
1211 if (argc > optind) {
1212 arg_parameters = strv_copy(argv + optind);
1213 if (!arg_parameters)
1214 return log_oom();
1215
1216 arg_settings_mask |= SETTING_START_MODE;
1217 }
1218
1219 /* Load all settings from .nspawn files */
1220 if (mask_no_settings)
1221 arg_settings_mask = 0;
1222
1223 /* Don't load any settings from .nspawn files */
1224 if (mask_all_settings)
1225 arg_settings_mask = _SETTINGS_MASK_ALL;
1226
1227 arg_caps_retain = (arg_caps_retain | plus | (arg_private_network ? 1ULL << CAP_NET_ADMIN : 0)) & ~minus;
1228
1229 r = cg_unified_flush();
1230 if (r < 0)
1231 return log_error_errno(r, "Failed to determine whether the unified cgroups hierarchy is used: %m");
1232
1233 e = getenv("SYSTEMD_NSPAWN_CONTAINER_SERVICE");
1234 if (e)
1235 arg_container_service_name = e;
1236
1237 r = getenv_bool("SYSTEMD_NSPAWN_USE_CGNS");
1238 if (r < 0)
1239 arg_use_cgns = cg_ns_supported();
1240 else
1241 arg_use_cgns = r;
1242
1243 r = custom_mount_check_all();
1244 if (r < 0)
1245 return r;
1246
1247 return 1;
1248 }
1249
1250 static int verify_arguments(void) {
1251 if (arg_userns_mode != USER_NAMESPACE_NO && (arg_mount_settings & MOUNT_APPLY_APIVFS_NETNS) && !arg_private_network) {
1252 log_error("Invalid namespacing settings. Mounting sysfs with --private-users requires --private-network.");
1253 return -EINVAL;
1254 }
1255
1256 if (arg_userns_mode != USER_NAMESPACE_NO && !(arg_mount_settings & MOUNT_APPLY_APIVFS_RO)) {
1257 log_error("Cannot combine --private-users with read-write mounts.");
1258 return -EINVAL;
1259 }
1260
1261 if (arg_volatile_mode != VOLATILE_NO && arg_read_only) {
1262 log_error("Cannot combine --read-only with --volatile. Note that --volatile already implies a read-only base hierarchy.");
1263 return -EINVAL;
1264 }
1265
1266 if (arg_expose_ports && !arg_private_network) {
1267 log_error("Cannot use --port= without private networking.");
1268 return -EINVAL;
1269 }
1270
1271 #if ! HAVE_LIBIPTC
1272 if (arg_expose_ports) {
1273 log_error("--port= is not supported, compiled without libiptc support.");
1274 return -EOPNOTSUPP;
1275 }
1276 #endif
1277
1278 if (arg_start_mode == START_BOOT && arg_kill_signal <= 0)
1279 arg_kill_signal = SIGRTMIN+3;
1280
1281 return 0;
1282 }
1283
1284 static int userns_lchown(const char *p, uid_t uid, gid_t gid) {
1285 assert(p);
1286
1287 if (arg_userns_mode == USER_NAMESPACE_NO)
1288 return 0;
1289
1290 if (uid == UID_INVALID && gid == GID_INVALID)
1291 return 0;
1292
1293 if (uid != UID_INVALID) {
1294 uid += arg_uid_shift;
1295
1296 if (uid < arg_uid_shift || uid >= arg_uid_shift + arg_uid_range)
1297 return -EOVERFLOW;
1298 }
1299
1300 if (gid != GID_INVALID) {
1301 gid += (gid_t) arg_uid_shift;
1302
1303 if (gid < (gid_t) arg_uid_shift || gid >= (gid_t) (arg_uid_shift + arg_uid_range))
1304 return -EOVERFLOW;
1305 }
1306
1307 if (lchown(p, uid, gid) < 0)
1308 return -errno;
1309
1310 return 0;
1311 }
1312
1313 static int userns_mkdir(const char *root, const char *path, mode_t mode, uid_t uid, gid_t gid) {
1314 const char *q;
1315 int r;
1316
1317 q = prefix_roota(root, path);
1318 r = mkdir_errno_wrapper(q, mode);
1319 if (r == -EEXIST)
1320 return 0;
1321 if (r < 0)
1322 return r;
1323
1324 return userns_lchown(q, uid, gid);
1325 }
1326
1327 static int setup_timezone(const char *dest) {
1328 _cleanup_free_ char *p = NULL, *q = NULL;
1329 const char *where, *check, *what;
1330 char *z, *y;
1331 int r;
1332
1333 assert(dest);
1334
1335 /* Fix the timezone, if possible */
1336 r = readlink_malloc("/etc/localtime", &p);
1337 if (r < 0) {
1338 log_warning("host's /etc/localtime is not a symlink, not updating container timezone.");
1339 /* to handle warning, delete /etc/localtime and replace it
1340 * with a symbolic link to a time zone data file.
1341 *
1342 * Example:
1343 * ln -s /usr/share/zoneinfo/UTC /etc/localtime
1344 */
1345 return 0;
1346 }
1347
1348 z = path_startswith(p, "../usr/share/zoneinfo/");
1349 if (!z)
1350 z = path_startswith(p, "/usr/share/zoneinfo/");
1351 if (!z) {
1352 log_warning("/etc/localtime does not point into /usr/share/zoneinfo/, not updating container timezone.");
1353 return 0;
1354 }
1355
1356 where = prefix_roota(dest, "/etc/localtime");
1357 r = readlink_malloc(where, &q);
1358 if (r >= 0) {
1359 y = path_startswith(q, "../usr/share/zoneinfo/");
1360 if (!y)
1361 y = path_startswith(q, "/usr/share/zoneinfo/");
1362
1363 /* Already pointing to the right place? Then do nothing .. */
1364 if (y && streq(y, z))
1365 return 0;
1366 }
1367
1368 check = strjoina("/usr/share/zoneinfo/", z);
1369 check = prefix_roota(dest, check);
1370 if (laccess(check, F_OK) < 0) {
1371 log_warning("Timezone %s does not exist in container, not updating container timezone.", z);
1372 return 0;
1373 }
1374
1375 if (unlink(where) < 0 && errno != ENOENT) {
1376 log_full_errno(IN_SET(errno, EROFS, EACCES, EPERM) ? LOG_DEBUG : LOG_WARNING, /* Don't complain on read-only images */
1377 errno,
1378 "Failed to remove existing timezone info %s in container, ignoring: %m", where);
1379 return 0;
1380 }
1381
1382 what = strjoina("../usr/share/zoneinfo/", z);
1383 if (symlink(what, where) < 0) {
1384 log_full_errno(IN_SET(errno, EROFS, EACCES, EPERM) ? LOG_DEBUG : LOG_WARNING,
1385 errno,
1386 "Failed to correct timezone of container, ignoring: %m");
1387 return 0;
1388 }
1389
1390 r = userns_lchown(where, 0, 0);
1391 if (r < 0)
1392 return log_warning_errno(r, "Failed to chown /etc/localtime: %m");
1393
1394 return 0;
1395 }
1396
1397 static int resolved_listening(void) {
1398 _cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL;
1399 _cleanup_free_ char *dns_stub_listener_mode = NULL;
1400 int r;
1401
1402 /* Check if resolved is listening */
1403
1404 r = sd_bus_open_system(&bus);
1405 if (r < 0)
1406 return r;
1407
1408 r = bus_name_has_owner(bus, "org.freedesktop.resolve1", NULL);
1409 if (r <= 0)
1410 return r;
1411
1412 r = sd_bus_get_property_string(bus,
1413 "org.freedesktop.resolve1",
1414 "/org/freedesktop/resolve1",
1415 "org.freedesktop.resolve1.Manager",
1416 "DNSStubListener",
1417 NULL,
1418 &dns_stub_listener_mode);
1419 if (r < 0)
1420 return r;
1421
1422 return STR_IN_SET(dns_stub_listener_mode, "udp", "yes");
1423 }
1424
1425 static int setup_resolv_conf(const char *dest) {
1426 _cleanup_free_ char *resolved = NULL, *etc = NULL;
1427 const char *where;
1428 int r, found;
1429
1430 assert(dest);
1431
1432 if (arg_private_network)
1433 return 0;
1434
1435 r = chase_symlinks("/etc", dest, CHASE_PREFIX_ROOT, &etc);
1436 if (r < 0) {
1437 log_warning_errno(r, "Failed to resolve /etc path in container, ignoring: %m");
1438 return 0;
1439 }
1440
1441 where = strjoina(etc, "/resolv.conf");
1442 found = chase_symlinks(where, dest, CHASE_NONEXISTENT, &resolved);
1443 if (found < 0) {
1444 log_warning_errno(found, "Failed to resolve /etc/resolv.conf path in container, ignoring: %m");
1445 return 0;
1446 }
1447
1448 if (access(STATIC_RESOLV_CONF, F_OK) >= 0 &&
1449 resolved_listening() > 0) {
1450
1451 /* resolved is enabled on the host. In this, case bind mount its static resolv.conf file into the
1452 * container, so that the container can use the host's resolver. Given that network namespacing is
1453 * disabled it's only natural of the container also uses the host's resolver. It also has the big
1454 * advantage that the container will be able to follow the host's DNS server configuration changes
1455 * transparently. */
1456
1457 if (found == 0) /* missing? */
1458 (void) touch(resolved);
1459
1460 r = mount_verbose(LOG_DEBUG, STATIC_RESOLV_CONF, resolved, NULL, MS_BIND, NULL);
1461 if (r >= 0)
1462 return mount_verbose(LOG_ERR, NULL, resolved, NULL, MS_BIND|MS_REMOUNT|MS_RDONLY|MS_NOSUID|MS_NODEV, NULL);
1463 }
1464
1465 /* If that didn't work, let's copy the file */
1466 r = copy_file("/etc/resolv.conf", where, O_TRUNC|O_NOFOLLOW, 0644, 0, COPY_REFLINK);
1467 if (r < 0) {
1468 /* If the file already exists as symlink, let's suppress the warning, under the assumption that
1469 * resolved or something similar runs inside and the symlink points there.
1470 *
1471 * If the disk image is read-only, there's also no point in complaining.
1472 */
1473 log_full_errno(IN_SET(r, -ELOOP, -EROFS, -EACCES, -EPERM) ? LOG_DEBUG : LOG_WARNING, r,
1474 "Failed to copy /etc/resolv.conf to %s, ignoring: %m", where);
1475 return 0;
1476 }
1477
1478 r = userns_lchown(where, 0, 0);
1479 if (r < 0)
1480 log_warning_errno(r, "Failed to chown /etc/resolv.conf, ignoring: %m");
1481
1482 return 0;
1483 }
1484
1485 static int setup_boot_id(const char *dest) {
1486 sd_id128_t rnd = SD_ID128_NULL;
1487 const char *from, *to;
1488 int r;
1489
1490 /* Generate a new randomized boot ID, so that each boot-up of
1491 * the container gets a new one */
1492
1493 from = prefix_roota(dest, "/run/proc-sys-kernel-random-boot-id");
1494 to = prefix_roota(dest, "/proc/sys/kernel/random/boot_id");
1495
1496 r = sd_id128_randomize(&rnd);
1497 if (r < 0)
1498 return log_error_errno(r, "Failed to generate random boot id: %m");
1499
1500 r = id128_write(from, ID128_UUID, rnd, false);
1501 if (r < 0)
1502 return log_error_errno(r, "Failed to write boot id: %m");
1503
1504 r = mount_verbose(LOG_ERR, from, to, NULL, MS_BIND, NULL);
1505 if (r >= 0)
1506 r = mount_verbose(LOG_ERR, NULL, to, NULL,
1507 MS_BIND|MS_REMOUNT|MS_RDONLY|MS_NOSUID|MS_NODEV, NULL);
1508
1509 (void) unlink(from);
1510 return r;
1511 }
1512
1513 static int copy_devnodes(const char *dest) {
1514
1515 static const char devnodes[] =
1516 "null\0"
1517 "zero\0"
1518 "full\0"
1519 "random\0"
1520 "urandom\0"
1521 "tty\0"
1522 "net/tun\0";
1523
1524 const char *d;
1525 int r = 0;
1526 _cleanup_umask_ mode_t u;
1527
1528 assert(dest);
1529
1530 u = umask(0000);
1531
1532 /* Create /dev/net, so that we can create /dev/net/tun in it */
1533 if (userns_mkdir(dest, "/dev/net", 0755, 0, 0) < 0)
1534 return log_error_errno(r, "Failed to create /dev/net directory: %m");
1535
1536 NULSTR_FOREACH(d, devnodes) {
1537 _cleanup_free_ char *from = NULL, *to = NULL;
1538 struct stat st;
1539
1540 from = strappend("/dev/", d);
1541 to = prefix_root(dest, from);
1542
1543 if (stat(from, &st) < 0) {
1544
1545 if (errno != ENOENT)
1546 return log_error_errno(errno, "Failed to stat %s: %m", from);
1547
1548 } else if (!S_ISCHR(st.st_mode) && !S_ISBLK(st.st_mode)) {
1549
1550 log_error("%s is not a char or block device, cannot copy.", from);
1551 return -EIO;
1552
1553 } else {
1554 if (mknod(to, st.st_mode, st.st_rdev) < 0) {
1555 /* Explicitly warn the user when /dev is already populated. */
1556 if (errno == EEXIST)
1557 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);
1558 if (errno != EPERM)
1559 return log_error_errno(errno, "mknod(%s) failed: %m", to);
1560
1561 /* Some systems abusively restrict mknod but
1562 * allow bind mounts. */
1563 r = touch(to);
1564 if (r < 0)
1565 return log_error_errno(r, "touch (%s) failed: %m", to);
1566 r = mount_verbose(LOG_DEBUG, from, to, NULL, MS_BIND, NULL);
1567 if (r < 0)
1568 return log_error_errno(r, "Both mknod and bind mount (%s) failed: %m", to);
1569 }
1570
1571 r = userns_lchown(to, 0, 0);
1572 if (r < 0)
1573 return log_error_errno(r, "chown() of device node %s failed: %m", to);
1574 }
1575 }
1576
1577 return r;
1578 }
1579
1580 static int setup_pts(const char *dest) {
1581 _cleanup_free_ char *options = NULL;
1582 const char *p;
1583 int r;
1584
1585 #if HAVE_SELINUX
1586 if (arg_selinux_apifs_context)
1587 (void) asprintf(&options,
1588 "newinstance,ptmxmode=0666,mode=620,gid=" GID_FMT ",context=\"%s\"",
1589 arg_uid_shift + TTY_GID,
1590 arg_selinux_apifs_context);
1591 else
1592 #endif
1593 (void) asprintf(&options,
1594 "newinstance,ptmxmode=0666,mode=620,gid=" GID_FMT,
1595 arg_uid_shift + TTY_GID);
1596
1597 if (!options)
1598 return log_oom();
1599
1600 /* Mount /dev/pts itself */
1601 p = prefix_roota(dest, "/dev/pts");
1602 r = mkdir_errno_wrapper(p, 0755);
1603 if (r < 0)
1604 return log_error_errno(r, "Failed to create /dev/pts: %m");
1605
1606 r = mount_verbose(LOG_ERR, "devpts", p, "devpts", MS_NOSUID|MS_NOEXEC, options);
1607 if (r < 0)
1608 return r;
1609 r = userns_lchown(p, 0, 0);
1610 if (r < 0)
1611 return log_error_errno(r, "Failed to chown /dev/pts: %m");
1612
1613 /* Create /dev/ptmx symlink */
1614 p = prefix_roota(dest, "/dev/ptmx");
1615 if (symlink("pts/ptmx", p) < 0)
1616 return log_error_errno(errno, "Failed to create /dev/ptmx symlink: %m");
1617 r = userns_lchown(p, 0, 0);
1618 if (r < 0)
1619 return log_error_errno(r, "Failed to chown /dev/ptmx: %m");
1620
1621 /* And fix /dev/pts/ptmx ownership */
1622 p = prefix_roota(dest, "/dev/pts/ptmx");
1623 r = userns_lchown(p, 0, 0);
1624 if (r < 0)
1625 return log_error_errno(r, "Failed to chown /dev/pts/ptmx: %m");
1626
1627 return 0;
1628 }
1629
1630 static int setup_dev_console(const char *dest, const char *console) {
1631 _cleanup_umask_ mode_t u;
1632 const char *to;
1633 int r;
1634
1635 assert(dest);
1636 assert(console);
1637
1638 u = umask(0000);
1639
1640 r = chmod_and_chown(console, 0600, arg_uid_shift, arg_uid_shift);
1641 if (r < 0)
1642 return log_error_errno(r, "Failed to correct access mode for TTY: %m");
1643
1644 /* We need to bind mount the right tty to /dev/console since
1645 * ptys can only exist on pts file systems. To have something
1646 * to bind mount things on we create a empty regular file. */
1647
1648 to = prefix_roota(dest, "/dev/console");
1649 r = touch(to);
1650 if (r < 0)
1651 return log_error_errno(r, "touch() for /dev/console failed: %m");
1652
1653 return mount_verbose(LOG_ERR, console, to, NULL, MS_BIND, NULL);
1654 }
1655
1656 static int setup_keyring(void) {
1657 key_serial_t keyring;
1658
1659 /* Allocate a new session keyring for the container. This makes sure the keyring of the session systemd-nspawn
1660 * was invoked from doesn't leak into the container. Note that by default we block keyctl() and request_key()
1661 * anyway via seccomp so doing this operation isn't strictly necessary, but in case people explicitly whitelist
1662 * these system calls let's make sure we don't leak anything into the container. */
1663
1664 keyring = keyctl(KEYCTL_JOIN_SESSION_KEYRING, 0, 0, 0, 0);
1665 if (keyring == -1) {
1666 if (errno == ENOSYS)
1667 log_debug_errno(errno, "Kernel keyring not supported, ignoring.");
1668 else if (IN_SET(errno, EACCES, EPERM))
1669 log_debug_errno(errno, "Kernel keyring access prohibited, ignoring.");
1670 else
1671 return log_error_errno(errno, "Setting up kernel keyring failed: %m");
1672 }
1673
1674 return 0;
1675 }
1676
1677 static int setup_kmsg(const char *dest, int kmsg_socket) {
1678 const char *from, *to;
1679 _cleanup_umask_ mode_t u;
1680 int fd, r;
1681
1682 assert(kmsg_socket >= 0);
1683
1684 u = umask(0000);
1685
1686 /* We create the kmsg FIFO as /run/kmsg, but immediately
1687 * delete it after bind mounting it to /proc/kmsg. While FIFOs
1688 * on the reading side behave very similar to /proc/kmsg,
1689 * their writing side behaves differently from /dev/kmsg in
1690 * that writing blocks when nothing is reading. In order to
1691 * avoid any problems with containers deadlocking due to this
1692 * we simply make /dev/kmsg unavailable to the container. */
1693 from = prefix_roota(dest, "/run/kmsg");
1694 to = prefix_roota(dest, "/proc/kmsg");
1695
1696 if (mkfifo(from, 0600) < 0)
1697 return log_error_errno(errno, "mkfifo() for /run/kmsg failed: %m");
1698 r = mount_verbose(LOG_ERR, from, to, NULL, MS_BIND, NULL);
1699 if (r < 0)
1700 return r;
1701
1702 fd = open(from, O_RDWR|O_NDELAY|O_CLOEXEC);
1703 if (fd < 0)
1704 return log_error_errno(errno, "Failed to open fifo: %m");
1705
1706 /* Store away the fd in the socket, so that it stays open as
1707 * long as we run the child */
1708 r = send_one_fd(kmsg_socket, fd, 0);
1709 safe_close(fd);
1710
1711 if (r < 0)
1712 return log_error_errno(r, "Failed to send FIFO fd: %m");
1713
1714 /* And now make the FIFO unavailable as /run/kmsg... */
1715 (void) unlink(from);
1716
1717 return 0;
1718 }
1719
1720 static int on_address_change(sd_netlink *rtnl, sd_netlink_message *m, void *userdata) {
1721 union in_addr_union *exposed = userdata;
1722
1723 assert(rtnl);
1724 assert(m);
1725 assert(exposed);
1726
1727 expose_port_execute(rtnl, arg_expose_ports, exposed);
1728 return 0;
1729 }
1730
1731 static int setup_hostname(void) {
1732
1733 if ((arg_clone_ns_flags & CLONE_NEWUTS) == 0)
1734 return 0;
1735
1736 if (sethostname_idempotent(arg_machine) < 0)
1737 return -errno;
1738
1739 return 0;
1740 }
1741
1742 static int setup_journal(const char *directory) {
1743 sd_id128_t this_id;
1744 _cleanup_free_ char *d = NULL;
1745 const char *p, *q;
1746 bool try;
1747 char id[33];
1748 int r;
1749
1750 /* Don't link journals in ephemeral mode */
1751 if (arg_ephemeral)
1752 return 0;
1753
1754 if (arg_link_journal == LINK_NO)
1755 return 0;
1756
1757 try = arg_link_journal_try || arg_link_journal == LINK_AUTO;
1758
1759 r = sd_id128_get_machine(&this_id);
1760 if (r < 0)
1761 return log_error_errno(r, "Failed to retrieve machine ID: %m");
1762
1763 if (sd_id128_equal(arg_uuid, this_id)) {
1764 log_full(try ? LOG_WARNING : LOG_ERR,
1765 "Host and machine ids are equal (%s): refusing to link journals", sd_id128_to_string(arg_uuid, id));
1766 if (try)
1767 return 0;
1768 return -EEXIST;
1769 }
1770
1771 r = userns_mkdir(directory, "/var", 0755, 0, 0);
1772 if (r < 0)
1773 return log_error_errno(r, "Failed to create /var: %m");
1774
1775 r = userns_mkdir(directory, "/var/log", 0755, 0, 0);
1776 if (r < 0)
1777 return log_error_errno(r, "Failed to create /var/log: %m");
1778
1779 r = userns_mkdir(directory, "/var/log/journal", 0755, 0, 0);
1780 if (r < 0)
1781 return log_error_errno(r, "Failed to create /var/log/journal: %m");
1782
1783 (void) sd_id128_to_string(arg_uuid, id);
1784
1785 p = strjoina("/var/log/journal/", id);
1786 q = prefix_roota(directory, p);
1787
1788 if (path_is_mount_point(p, NULL, 0) > 0) {
1789 if (try)
1790 return 0;
1791
1792 log_error("%s: already a mount point, refusing to use for journal", p);
1793 return -EEXIST;
1794 }
1795
1796 if (path_is_mount_point(q, NULL, 0) > 0) {
1797 if (try)
1798 return 0;
1799
1800 log_error("%s: already a mount point, refusing to use for journal", q);
1801 return -EEXIST;
1802 }
1803
1804 r = readlink_and_make_absolute(p, &d);
1805 if (r >= 0) {
1806 if (IN_SET(arg_link_journal, LINK_GUEST, LINK_AUTO) &&
1807 path_equal(d, q)) {
1808
1809 r = userns_mkdir(directory, p, 0755, 0, 0);
1810 if (r < 0)
1811 log_warning_errno(r, "Failed to create directory %s: %m", q);
1812 return 0;
1813 }
1814
1815 if (unlink(p) < 0)
1816 return log_error_errno(errno, "Failed to remove symlink %s: %m", p);
1817 } else if (r == -EINVAL) {
1818
1819 if (arg_link_journal == LINK_GUEST &&
1820 rmdir(p) < 0) {
1821
1822 if (errno == ENOTDIR) {
1823 log_error("%s already exists and is neither a symlink nor a directory", p);
1824 return r;
1825 } else
1826 return log_error_errno(errno, "Failed to remove %s: %m", p);
1827 }
1828 } else if (r != -ENOENT)
1829 return log_error_errno(r, "readlink(%s) failed: %m", p);
1830
1831 if (arg_link_journal == LINK_GUEST) {
1832
1833 if (symlink(q, p) < 0) {
1834 if (try) {
1835 log_debug_errno(errno, "Failed to symlink %s to %s, skipping journal setup: %m", q, p);
1836 return 0;
1837 } else
1838 return log_error_errno(errno, "Failed to symlink %s to %s: %m", q, p);
1839 }
1840
1841 r = userns_mkdir(directory, p, 0755, 0, 0);
1842 if (r < 0)
1843 log_warning_errno(r, "Failed to create directory %s: %m", q);
1844 return 0;
1845 }
1846
1847 if (arg_link_journal == LINK_HOST) {
1848 /* don't create parents here — if the host doesn't have
1849 * permanent journal set up, don't force it here */
1850
1851 r = mkdir_errno_wrapper(p, 0755);
1852 if (r < 0 && r != -EEXIST) {
1853 if (try) {
1854 log_debug_errno(r, "Failed to create %s, skipping journal setup: %m", p);
1855 return 0;
1856 } else
1857 return log_error_errno(r, "Failed to create %s: %m", p);
1858 }
1859
1860 } else if (access(p, F_OK) < 0)
1861 return 0;
1862
1863 if (dir_is_empty(q) == 0)
1864 log_warning("%s is not empty, proceeding anyway.", q);
1865
1866 r = userns_mkdir(directory, p, 0755, 0, 0);
1867 if (r < 0)
1868 return log_error_errno(r, "Failed to create %s: %m", q);
1869
1870 r = mount_verbose(LOG_DEBUG, p, q, NULL, MS_BIND, NULL);
1871 if (r < 0)
1872 return log_error_errno(errno, "Failed to bind mount journal from host into guest: %m");
1873
1874 return 0;
1875 }
1876
1877 static int drop_capabilities(void) {
1878 return capability_bounding_set_drop(arg_caps_retain, false);
1879 }
1880
1881 static int reset_audit_loginuid(void) {
1882 _cleanup_free_ char *p = NULL;
1883 int r;
1884
1885 if ((arg_clone_ns_flags & CLONE_NEWPID) == 0)
1886 return 0;
1887
1888 r = read_one_line_file("/proc/self/loginuid", &p);
1889 if (r == -ENOENT)
1890 return 0;
1891 if (r < 0)
1892 return log_error_errno(r, "Failed to read /proc/self/loginuid: %m");
1893
1894 /* Already reset? */
1895 if (streq(p, "4294967295"))
1896 return 0;
1897
1898 r = write_string_file("/proc/self/loginuid", "4294967295", 0);
1899 if (r < 0) {
1900 log_error_errno(r,
1901 "Failed to reset audit login UID. This probably means that your kernel is too\n"
1902 "old and you have audit enabled. Note that the auditing subsystem is known to\n"
1903 "be incompatible with containers on old kernels. Please make sure to upgrade\n"
1904 "your kernel or to off auditing with 'audit=0' on the kernel command line before\n"
1905 "using systemd-nspawn. Sleeping for 5s... (%m)");
1906
1907 sleep(5);
1908 }
1909
1910 return 0;
1911 }
1912
1913
1914 static int setup_propagate(const char *root) {
1915 const char *p, *q;
1916 int r;
1917
1918 (void) mkdir_p("/run/systemd/nspawn/", 0755);
1919 (void) mkdir_p("/run/systemd/nspawn/propagate", 0600);
1920 p = strjoina("/run/systemd/nspawn/propagate/", arg_machine);
1921 (void) mkdir_p(p, 0600);
1922
1923 r = userns_mkdir(root, "/run/systemd", 0755, 0, 0);
1924 if (r < 0)
1925 return log_error_errno(r, "Failed to create /run/systemd: %m");
1926
1927 r = userns_mkdir(root, "/run/systemd/nspawn", 0755, 0, 0);
1928 if (r < 0)
1929 return log_error_errno(r, "Failed to create /run/systemd/nspawn: %m");
1930
1931 r = userns_mkdir(root, "/run/systemd/nspawn/incoming", 0600, 0, 0);
1932 if (r < 0)
1933 return log_error_errno(r, "Failed to create /run/systemd/nspawn/incoming: %m");
1934
1935 q = prefix_roota(root, "/run/systemd/nspawn/incoming");
1936 r = mount_verbose(LOG_ERR, p, q, NULL, MS_BIND, NULL);
1937 if (r < 0)
1938 return r;
1939
1940 r = mount_verbose(LOG_ERR, NULL, q, NULL, MS_BIND|MS_REMOUNT|MS_RDONLY, NULL);
1941 if (r < 0)
1942 return r;
1943
1944 /* machined will MS_MOVE into that directory, and that's only
1945 * supported for non-shared mounts. */
1946 return mount_verbose(LOG_ERR, NULL, q, NULL, MS_SLAVE, NULL);
1947 }
1948
1949 static int setup_machine_id(const char *directory) {
1950 const char *etc_machine_id;
1951 sd_id128_t id;
1952 int r;
1953
1954 /* If the UUID in the container is already set, then that's what counts, and we use. If it isn't set, and the
1955 * caller passed --uuid=, then we'll pass it in the $container_uuid env var to PID 1 of the container. The
1956 * assumption is that PID 1 will then write it to /etc/machine-id to make it persistent. If --uuid= is not
1957 * passed we generate a random UUID, and pass it via $container_uuid. In effect this means that /etc/machine-id
1958 * in the container and our idea of the container UUID will always be in sync (at least if PID 1 in the
1959 * container behaves nicely). */
1960
1961 etc_machine_id = prefix_roota(directory, "/etc/machine-id");
1962
1963 r = id128_read(etc_machine_id, ID128_PLAIN, &id);
1964 if (r < 0) {
1965 if (!IN_SET(r, -ENOENT, -ENOMEDIUM)) /* If the file is missing or empty, we don't mind */
1966 return log_error_errno(r, "Failed to read machine ID from container image: %m");
1967
1968 if (sd_id128_is_null(arg_uuid)) {
1969 r = sd_id128_randomize(&arg_uuid);
1970 if (r < 0)
1971 return log_error_errno(r, "Failed to acquire randomized machine UUID: %m");
1972 }
1973 } else {
1974 if (sd_id128_is_null(id)) {
1975 log_error("Machine ID in container image is zero, refusing.");
1976 return -EINVAL;
1977 }
1978
1979 arg_uuid = id;
1980 }
1981
1982 return 0;
1983 }
1984
1985 static int recursive_chown(const char *directory, uid_t shift, uid_t range) {
1986 int r;
1987
1988 assert(directory);
1989
1990 if (arg_userns_mode == USER_NAMESPACE_NO || !arg_userns_chown)
1991 return 0;
1992
1993 r = path_patch_uid(directory, arg_uid_shift, arg_uid_range);
1994 if (r == -EOPNOTSUPP)
1995 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.");
1996 if (r == -EBADE)
1997 return log_error_errno(r, "Upper 16 bits of root directory UID and GID do not match.");
1998 if (r < 0)
1999 return log_error_errno(r, "Failed to adjust UID/GID shift of OS tree: %m");
2000 if (r == 0)
2001 log_debug("Root directory of image is already owned by the right UID/GID range, skipping recursive chown operation.");
2002 else
2003 log_debug("Patched directory tree to match UID/GID range.");
2004
2005 return r;
2006 }
2007
2008 /*
2009 * Return values:
2010 * < 0 : wait_for_terminate() failed to get the state of the
2011 * container, the container was terminated by a signal, or
2012 * failed for an unknown reason. No change is made to the
2013 * container argument.
2014 * > 0 : The program executed in the container terminated with an
2015 * error. The exit code of the program executed in the
2016 * container is returned. The container argument has been set
2017 * to CONTAINER_TERMINATED.
2018 * 0 : The container is being rebooted, has been shut down or exited
2019 * successfully. The container argument has been set to either
2020 * CONTAINER_TERMINATED or CONTAINER_REBOOTED.
2021 *
2022 * That is, success is indicated by a return value of zero, and an
2023 * error is indicated by a non-zero value.
2024 */
2025 static int wait_for_container(pid_t pid, ContainerStatus *container) {
2026 siginfo_t status;
2027 int r;
2028
2029 r = wait_for_terminate(pid, &status);
2030 if (r < 0)
2031 return log_warning_errno(r, "Failed to wait for container: %m");
2032
2033 switch (status.si_code) {
2034
2035 case CLD_EXITED:
2036 if (status.si_status == 0)
2037 log_full(arg_quiet ? LOG_DEBUG : LOG_INFO, "Container %s exited successfully.", arg_machine);
2038 else
2039 log_full(arg_quiet ? LOG_DEBUG : LOG_INFO, "Container %s failed with error code %i.", arg_machine, status.si_status);
2040
2041 *container = CONTAINER_TERMINATED;
2042 return status.si_status;
2043
2044 case CLD_KILLED:
2045 if (status.si_status == SIGINT) {
2046 log_full(arg_quiet ? LOG_DEBUG : LOG_INFO, "Container %s has been shut down.", arg_machine);
2047 *container = CONTAINER_TERMINATED;
2048 return 0;
2049
2050 } else if (status.si_status == SIGHUP) {
2051 log_full(arg_quiet ? LOG_DEBUG : LOG_INFO, "Container %s is being rebooted.", arg_machine);
2052 *container = CONTAINER_REBOOTED;
2053 return 0;
2054 }
2055
2056 _fallthrough_;
2057 case CLD_DUMPED:
2058 log_error("Container %s terminated by signal %s.", arg_machine, signal_to_string(status.si_status));
2059 return -EIO;
2060
2061 default:
2062 log_error("Container %s failed due to unknown reason.", arg_machine);
2063 return -EIO;
2064 }
2065 }
2066
2067 static int on_orderly_shutdown(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) {
2068 pid_t pid;
2069
2070 pid = PTR_TO_PID(userdata);
2071 if (pid > 0) {
2072 if (kill(pid, arg_kill_signal) >= 0) {
2073 log_info("Trying to halt container. Send SIGTERM again to trigger immediate termination.");
2074 sd_event_source_set_userdata(s, NULL);
2075 return 0;
2076 }
2077 }
2078
2079 sd_event_exit(sd_event_source_get_event(s), 0);
2080 return 0;
2081 }
2082
2083 static int on_sigchld(sd_event_source *s, const struct signalfd_siginfo *ssi, void *userdata) {
2084 pid_t pid;
2085
2086 assert(s);
2087 assert(ssi);
2088
2089 pid = PTR_TO_PID(userdata);
2090
2091 for (;;) {
2092 siginfo_t si = {};
2093
2094 if (waitid(P_ALL, 0, &si, WNOHANG|WNOWAIT|WEXITED) < 0)
2095 return log_error_errno(errno, "Failed to waitid(): %m");
2096 if (si.si_pid == 0) /* No pending children. */
2097 break;
2098 if (si.si_pid == pid) {
2099 /* The main process we care for has exited. Return from
2100 * signal handler but leave the zombie. */
2101 sd_event_exit(sd_event_source_get_event(s), 0);
2102 break;
2103 }
2104
2105 /* Reap all other children. */
2106 (void) waitid(P_PID, si.si_pid, &si, WNOHANG|WEXITED);
2107 }
2108
2109 return 0;
2110 }
2111
2112 static int on_request_stop(sd_bus_message *m, void *userdata, sd_bus_error *error) {
2113 pid_t pid;
2114
2115 assert(m);
2116
2117 pid = PTR_TO_PID(userdata);
2118
2119 if (arg_kill_signal > 0) {
2120 log_info("Container termination requested. Attempting to halt container.");
2121 (void) kill(pid, arg_kill_signal);
2122 } else {
2123 log_info("Container termination requested. Exiting.");
2124 sd_event_exit(sd_bus_get_event(sd_bus_message_get_bus(m)), 0);
2125 }
2126
2127 return 0;
2128 }
2129
2130 static int determine_names(void) {
2131 int r;
2132
2133 if (arg_template && !arg_directory && arg_machine) {
2134
2135 /* If --template= was specified then we should not
2136 * search for a machine, but instead create a new one
2137 * in /var/lib/machine. */
2138
2139 arg_directory = strjoin("/var/lib/machines/", arg_machine);
2140 if (!arg_directory)
2141 return log_oom();
2142 }
2143
2144 if (!arg_image && !arg_directory) {
2145 if (arg_machine) {
2146 _cleanup_(image_unrefp) Image *i = NULL;
2147
2148 r = image_find(arg_machine, &i);
2149 if (r < 0)
2150 return log_error_errno(r, "Failed to find image for machine '%s': %m", arg_machine);
2151 if (r == 0) {
2152 log_error("No image for machine '%s'.", arg_machine);
2153 return -ENOENT;
2154 }
2155
2156 if (IN_SET(i->type, IMAGE_RAW, IMAGE_BLOCK))
2157 r = free_and_strdup(&arg_image, i->path);
2158 else
2159 r = free_and_strdup(&arg_directory, i->path);
2160 if (r < 0)
2161 return log_oom();
2162
2163 if (!arg_ephemeral)
2164 arg_read_only = arg_read_only || i->read_only;
2165 } else {
2166 r = safe_getcwd(&arg_directory);
2167 if (r < 0)
2168 return log_error_errno(r, "Failed to determine current directory: %m");
2169 }
2170
2171 if (!arg_directory && !arg_image) {
2172 log_error("Failed to determine path, please use -D or -i.");
2173 return -EINVAL;
2174 }
2175 }
2176
2177 if (!arg_machine) {
2178
2179 if (arg_directory && path_equal(arg_directory, "/"))
2180 arg_machine = gethostname_malloc();
2181 else {
2182 if (arg_image) {
2183 char *e;
2184
2185 arg_machine = strdup(basename(arg_image));
2186
2187 /* Truncate suffix if there is one */
2188 e = endswith(arg_machine, ".raw");
2189 if (e)
2190 *e = 0;
2191 } else
2192 arg_machine = strdup(basename(arg_directory));
2193 }
2194 if (!arg_machine)
2195 return log_oom();
2196
2197 hostname_cleanup(arg_machine);
2198 if (!machine_name_is_valid(arg_machine)) {
2199 log_error("Failed to determine machine name automatically, please use -M.");
2200 return -EINVAL;
2201 }
2202
2203 if (arg_ephemeral) {
2204 char *b;
2205
2206 /* Add a random suffix when this is an
2207 * ephemeral machine, so that we can run many
2208 * instances at once without manually having
2209 * to specify -M each time. */
2210
2211 if (asprintf(&b, "%s-%016" PRIx64, arg_machine, random_u64()) < 0)
2212 return log_oom();
2213
2214 free(arg_machine);
2215 arg_machine = b;
2216 }
2217 }
2218
2219 return 0;
2220 }
2221
2222 static int chase_symlinks_and_update(char **p, unsigned flags) {
2223 char *chased;
2224 int r;
2225
2226 assert(p);
2227
2228 if (!*p)
2229 return 0;
2230
2231 r = chase_symlinks(*p, NULL, flags, &chased);
2232 if (r < 0)
2233 return log_error_errno(r, "Failed to resolve path %s: %m", *p);
2234
2235 free_and_replace(*p, chased);
2236 return r; /* r might be an fd here in case we ever use CHASE_OPEN in flags */
2237 }
2238
2239 static int determine_uid_shift(const char *directory) {
2240 int r;
2241
2242 if (arg_userns_mode == USER_NAMESPACE_NO) {
2243 arg_uid_shift = 0;
2244 return 0;
2245 }
2246
2247 if (arg_uid_shift == UID_INVALID) {
2248 struct stat st;
2249
2250 r = stat(directory, &st);
2251 if (r < 0)
2252 return log_error_errno(errno, "Failed to determine UID base of %s: %m", directory);
2253
2254 arg_uid_shift = st.st_uid & UINT32_C(0xffff0000);
2255
2256 if (arg_uid_shift != (st.st_gid & UINT32_C(0xffff0000))) {
2257 log_error("UID and GID base of %s don't match.", directory);
2258 return -EINVAL;
2259 }
2260
2261 arg_uid_range = UINT32_C(0x10000);
2262 }
2263
2264 if (arg_uid_shift > (uid_t) -1 - arg_uid_range) {
2265 log_error("UID base too high for UID range.");
2266 return -EINVAL;
2267 }
2268
2269 return 0;
2270 }
2271
2272 static int inner_child(
2273 Barrier *barrier,
2274 const char *directory,
2275 bool secondary,
2276 int kmsg_socket,
2277 int rtnl_socket,
2278 FDSet *fds) {
2279
2280 _cleanup_free_ char *home = NULL;
2281 char as_uuid[37];
2282 unsigned n_env = 1;
2283 const char *envp[] = {
2284 "PATH=" DEFAULT_PATH_SPLIT_USR,
2285 NULL, /* container */
2286 NULL, /* TERM */
2287 NULL, /* HOME */
2288 NULL, /* USER */
2289 NULL, /* LOGNAME */
2290 NULL, /* container_uuid */
2291 NULL, /* LISTEN_FDS */
2292 NULL, /* LISTEN_PID */
2293 NULL, /* NOTIFY_SOCKET */
2294 NULL
2295 };
2296 const char *exec_target;
2297
2298 _cleanup_strv_free_ char **env_use = NULL;
2299 int r;
2300
2301 assert(barrier);
2302 assert(directory);
2303 assert(kmsg_socket >= 0);
2304
2305 if (arg_userns_mode != USER_NAMESPACE_NO) {
2306 /* Tell the parent, that it now can write the UID map. */
2307 (void) barrier_place(barrier); /* #1 */
2308
2309 /* Wait until the parent wrote the UID map */
2310 if (!barrier_place_and_sync(barrier)) { /* #2 */
2311 log_error("Parent died too early");
2312 return -ESRCH;
2313 }
2314 }
2315
2316 r = reset_uid_gid();
2317 if (r < 0)
2318 return log_error_errno(r, "Couldn't become new root: %m");
2319
2320 r = mount_all(NULL,
2321 arg_mount_settings | MOUNT_IN_USERNS,
2322 arg_uid_shift,
2323 arg_uid_range,
2324 arg_selinux_apifs_context);
2325 if (r < 0)
2326 return r;
2327
2328 if (!arg_network_namespace_path && arg_private_network) {
2329 r = unshare(CLONE_NEWNET);
2330 if (r < 0)
2331 return log_error_errno(errno, "Failed to unshare network namespace: %m");
2332 }
2333
2334 r = mount_sysfs(NULL, arg_mount_settings);
2335 if (r < 0)
2336 return r;
2337
2338 /* Wait until we are cgroup-ified, so that we
2339 * can mount the right cgroup path writable */
2340 if (!barrier_place_and_sync(barrier)) { /* #3 */
2341 log_error("Parent died too early");
2342 return -ESRCH;
2343 }
2344
2345 if (arg_use_cgns && cg_ns_supported()) {
2346 r = unshare(CLONE_NEWCGROUP);
2347 if (r < 0)
2348 return log_error_errno(errno, "Failed to unshare cgroup namespace: %m");
2349 r = mount_cgroups(
2350 "",
2351 arg_unified_cgroup_hierarchy,
2352 arg_userns_mode != USER_NAMESPACE_NO,
2353 arg_uid_shift,
2354 arg_uid_range,
2355 arg_selinux_apifs_context,
2356 true);
2357 if (r < 0)
2358 return r;
2359 } else {
2360 r = mount_systemd_cgroup_writable("", arg_unified_cgroup_hierarchy);
2361 if (r < 0)
2362 return r;
2363 }
2364
2365 r = setup_boot_id(NULL);
2366 if (r < 0)
2367 return r;
2368
2369 r = setup_kmsg(NULL, kmsg_socket);
2370 if (r < 0)
2371 return r;
2372 kmsg_socket = safe_close(kmsg_socket);
2373
2374 umask(0022);
2375
2376 if (setsid() < 0)
2377 return log_error_errno(errno, "setsid() failed: %m");
2378
2379 if (arg_private_network)
2380 loopback_setup();
2381
2382 if (arg_expose_ports) {
2383 r = expose_port_send_rtnl(rtnl_socket);
2384 if (r < 0)
2385 return r;
2386 rtnl_socket = safe_close(rtnl_socket);
2387 }
2388
2389 r = drop_capabilities();
2390 if (r < 0)
2391 return log_error_errno(r, "drop_capabilities() failed: %m");
2392
2393 setup_hostname();
2394
2395 if (arg_personality != PERSONALITY_INVALID) {
2396 r = safe_personality(arg_personality);
2397 if (r < 0)
2398 return log_error_errno(r, "personality() failed: %m");
2399 } else if (secondary) {
2400 r = safe_personality(PER_LINUX32);
2401 if (r < 0)
2402 return log_error_errno(r, "personality() failed: %m");
2403 }
2404
2405 #if HAVE_SELINUX
2406 if (arg_selinux_context)
2407 if (setexeccon(arg_selinux_context) < 0)
2408 return log_error_errno(errno, "setexeccon(\"%s\") failed: %m", arg_selinux_context);
2409 #endif
2410
2411 r = change_uid_gid(arg_user, &home);
2412 if (r < 0)
2413 return r;
2414
2415 /* LXC sets container=lxc, so follow the scheme here */
2416 envp[n_env++] = strjoina("container=", arg_container_service_name);
2417
2418 envp[n_env] = strv_find_prefix(environ, "TERM=");
2419 if (envp[n_env])
2420 n_env++;
2421
2422 if ((asprintf((char**)(envp + n_env++), "HOME=%s", home ? home: "/root") < 0) ||
2423 (asprintf((char**)(envp + n_env++), "USER=%s", arg_user ? arg_user : "root") < 0) ||
2424 (asprintf((char**)(envp + n_env++), "LOGNAME=%s", arg_user ? arg_user : "root") < 0))
2425 return log_oom();
2426
2427 assert(!sd_id128_is_null(arg_uuid));
2428
2429 if (asprintf((char**)(envp + n_env++), "container_uuid=%s", id128_to_uuid_string(arg_uuid, as_uuid)) < 0)
2430 return log_oom();
2431
2432 if (fdset_size(fds) > 0) {
2433 r = fdset_cloexec(fds, false);
2434 if (r < 0)
2435 return log_error_errno(r, "Failed to unset O_CLOEXEC for file descriptors.");
2436
2437 if ((asprintf((char **)(envp + n_env++), "LISTEN_FDS=%u", fdset_size(fds)) < 0) ||
2438 (asprintf((char **)(envp + n_env++), "LISTEN_PID=1") < 0))
2439 return log_oom();
2440 }
2441 if (asprintf((char **)(envp + n_env++), "NOTIFY_SOCKET=%s", NSPAWN_NOTIFY_SOCKET_PATH) < 0)
2442 return log_oom();
2443
2444 env_use = strv_env_merge(2, envp, arg_setenv);
2445 if (!env_use)
2446 return log_oom();
2447
2448 /* Let the parent know that we are ready and
2449 * wait until the parent is ready with the
2450 * setup, too... */
2451 if (!barrier_place_and_sync(barrier)) { /* #4 */
2452 log_error("Parent died too early");
2453 return -ESRCH;
2454 }
2455
2456 if (arg_chdir)
2457 if (chdir(arg_chdir) < 0)
2458 return log_error_errno(errno, "Failed to change to specified working directory %s: %m", arg_chdir);
2459
2460 if (arg_start_mode == START_PID2) {
2461 r = stub_pid1(arg_uuid);
2462 if (r < 0)
2463 return r;
2464 }
2465
2466 /* Now, explicitly close the log, so that we
2467 * then can close all remaining fds. Closing
2468 * the log explicitly first has the benefit
2469 * that the logging subsystem knows about it,
2470 * and is thus ready to be reopened should we
2471 * need it again. Note that the other fds
2472 * closed here are at least the locking and
2473 * barrier fds. */
2474 log_close();
2475 (void) fdset_close_others(fds);
2476
2477 if (arg_start_mode == START_BOOT) {
2478 char **a;
2479 size_t m;
2480
2481 /* Automatically search for the init system */
2482
2483 m = strv_length(arg_parameters);
2484 a = newa(char*, m + 2);
2485 memcpy_safe(a + 1, arg_parameters, m * sizeof(char*));
2486 a[1 + m] = NULL;
2487
2488 a[0] = (char*) "/usr/lib/systemd/systemd";
2489 execve(a[0], a, env_use);
2490
2491 a[0] = (char*) "/lib/systemd/systemd";
2492 execve(a[0], a, env_use);
2493
2494 a[0] = (char*) "/sbin/init";
2495 execve(a[0], a, env_use);
2496
2497 exec_target = "/usr/lib/systemd/systemd, /lib/systemd/systemd, /sbin/init";
2498 } else if (!strv_isempty(arg_parameters)) {
2499 exec_target = arg_parameters[0];
2500 execvpe(arg_parameters[0], arg_parameters, env_use);
2501 } else {
2502 if (!arg_chdir)
2503 /* If we cannot change the directory, we'll end up in /, that is expected. */
2504 (void) chdir(home ?: "/root");
2505
2506 execle("/bin/bash", "-bash", NULL, env_use);
2507 execle("/bin/sh", "-sh", NULL, env_use);
2508
2509 exec_target = "/bin/bash, /bin/sh";
2510 }
2511
2512 r = -errno;
2513 (void) log_open();
2514 return log_error_errno(r, "execv(%s) failed: %m", exec_target);
2515 }
2516
2517 static int setup_sd_notify_child(void) {
2518 static const int one = 1;
2519 int fd = -1;
2520 union sockaddr_union sa = {
2521 .sa.sa_family = AF_UNIX,
2522 };
2523 int r;
2524
2525 fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
2526 if (fd < 0)
2527 return log_error_errno(errno, "Failed to allocate notification socket: %m");
2528
2529 (void) mkdir_parents(NSPAWN_NOTIFY_SOCKET_PATH, 0755);
2530 (void) unlink(NSPAWN_NOTIFY_SOCKET_PATH);
2531
2532 strncpy(sa.un.sun_path, NSPAWN_NOTIFY_SOCKET_PATH, sizeof(sa.un.sun_path)-1);
2533 r = bind(fd, &sa.sa, SOCKADDR_UN_LEN(sa.un));
2534 if (r < 0) {
2535 safe_close(fd);
2536 return log_error_errno(errno, "bind(%s) failed: %m", sa.un.sun_path);
2537 }
2538
2539 r = userns_lchown(NSPAWN_NOTIFY_SOCKET_PATH, 0, 0);
2540 if (r < 0) {
2541 safe_close(fd);
2542 return log_error_errno(r, "Failed to chown " NSPAWN_NOTIFY_SOCKET_PATH ": %m");
2543 }
2544
2545 r = setsockopt(fd, SOL_SOCKET, SO_PASSCRED, &one, sizeof(one));
2546 if (r < 0) {
2547 safe_close(fd);
2548 return log_error_errno(errno, "SO_PASSCRED failed: %m");
2549 }
2550
2551 return fd;
2552 }
2553
2554 static int outer_child(
2555 Barrier *barrier,
2556 const char *directory,
2557 const char *console,
2558 DissectedImage *dissected_image,
2559 bool interactive,
2560 bool secondary,
2561 int pid_socket,
2562 int uuid_socket,
2563 int notify_socket,
2564 int kmsg_socket,
2565 int rtnl_socket,
2566 int uid_shift_socket,
2567 int unified_cgroup_hierarchy_socket,
2568 FDSet *fds,
2569 int netns_fd) {
2570
2571 pid_t pid;
2572 ssize_t l;
2573 int r;
2574 _cleanup_close_ int fd = -1;
2575
2576 assert(barrier);
2577 assert(directory);
2578 assert(console);
2579 assert(pid_socket >= 0);
2580 assert(uuid_socket >= 0);
2581 assert(notify_socket >= 0);
2582 assert(kmsg_socket >= 0);
2583
2584 if (prctl(PR_SET_PDEATHSIG, SIGKILL) < 0)
2585 return log_error_errno(errno, "PR_SET_PDEATHSIG failed: %m");
2586
2587 if (interactive) {
2588 int terminal;
2589
2590 terminal = open_terminal(console, O_RDWR);
2591 if (terminal < 0)
2592 return log_error_errno(terminal, "Failed to open console: %m");
2593
2594 r = rearrange_stdio(terminal, terminal, terminal); /* invalidates 'terminal' on success and failure */
2595 if (r < 0)
2596 return log_error_errno(r, "Failed to move console to stdin/stdout/stderr: %m");
2597 }
2598
2599 r = reset_audit_loginuid();
2600 if (r < 0)
2601 return r;
2602
2603 /* Mark everything as slave, so that we still
2604 * receive mounts from the real root, but don't
2605 * propagate mounts to the real root. */
2606 r = mount_verbose(LOG_ERR, NULL, "/", NULL, MS_SLAVE|MS_REC, NULL);
2607 if (r < 0)
2608 return r;
2609
2610 if (dissected_image) {
2611 /* If we are operating on a disk image, then mount its root directory now, but leave out the rest. We
2612 * can read the UID shift from it if we need to. Further down we'll mount the rest, but then with the
2613 * uid shift known. That way we can mount VFAT file systems shifted to the right place right away. This
2614 * makes sure ESP partitions and userns are compatible. */
2615
2616 r = dissected_image_mount(dissected_image, directory, arg_uid_shift,
2617 DISSECT_IMAGE_MOUNT_ROOT_ONLY|DISSECT_IMAGE_DISCARD_ON_LOOP|(arg_read_only ? DISSECT_IMAGE_READ_ONLY : 0));
2618 if (r < 0)
2619 return r;
2620 }
2621
2622 r = determine_uid_shift(directory);
2623 if (r < 0)
2624 return r;
2625
2626 if (arg_userns_mode != USER_NAMESPACE_NO) {
2627 /* Let the parent know which UID shift we read from the image */
2628 l = send(uid_shift_socket, &arg_uid_shift, sizeof(arg_uid_shift), MSG_NOSIGNAL);
2629 if (l < 0)
2630 return log_error_errno(errno, "Failed to send UID shift: %m");
2631 if (l != sizeof(arg_uid_shift)) {
2632 log_error("Short write while sending UID shift.");
2633 return -EIO;
2634 }
2635
2636 if (arg_userns_mode == USER_NAMESPACE_PICK) {
2637 /* When we are supposed to pick the UID shift, the parent will check now whether the UID shift
2638 * we just read from the image is available. If yes, it will send the UID shift back to us, if
2639 * not it will pick a different one, and send it back to us. */
2640
2641 l = recv(uid_shift_socket, &arg_uid_shift, sizeof(arg_uid_shift), 0);
2642 if (l < 0)
2643 return log_error_errno(errno, "Failed to recv UID shift: %m");
2644 if (l != sizeof(arg_uid_shift)) {
2645 log_error("Short read while receiving UID shift.");
2646 return -EIO;
2647 }
2648 }
2649
2650 log_info("Selected user namespace base " UID_FMT " and range " UID_FMT ".", arg_uid_shift, arg_uid_range);
2651 }
2652
2653 if (dissected_image) {
2654 /* Now we know the uid shift, let's now mount everything else that might be in the image. */
2655 r = dissected_image_mount(dissected_image, directory, arg_uid_shift,
2656 DISSECT_IMAGE_MOUNT_NON_ROOT_ONLY|DISSECT_IMAGE_DISCARD_ON_LOOP|(arg_read_only ? DISSECT_IMAGE_READ_ONLY : 0));
2657 if (r < 0)
2658 return r;
2659 }
2660
2661 if (arg_unified_cgroup_hierarchy == CGROUP_UNIFIED_UNKNOWN) {
2662 /* OK, we don't know yet which cgroup mode to use yet. Let's figure it out, and tell the parent. */
2663
2664 r = detect_unified_cgroup_hierarchy_from_image(directory);
2665 if (r < 0)
2666 return r;
2667
2668 l = send(unified_cgroup_hierarchy_socket, &arg_unified_cgroup_hierarchy, sizeof(arg_unified_cgroup_hierarchy), MSG_NOSIGNAL);
2669 if (l < 0)
2670 return log_error_errno(errno, "Failed to send cgroup mode: %m");
2671 if (l != sizeof(arg_unified_cgroup_hierarchy)) {
2672 log_error("Short write while sending cgroup mode: %m");
2673 return -EIO;
2674 }
2675
2676 unified_cgroup_hierarchy_socket = safe_close(unified_cgroup_hierarchy_socket);
2677 }
2678
2679 /* Turn directory into bind mount */
2680 r = mount_verbose(LOG_ERR, directory, directory, NULL, MS_BIND|MS_REC, NULL);
2681 if (r < 0)
2682 return r;
2683
2684 r = setup_pivot_root(
2685 directory,
2686 arg_pivot_root_new,
2687 arg_pivot_root_old);
2688 if (r < 0)
2689 return r;
2690
2691 r = setup_volatile(
2692 directory,
2693 arg_volatile_mode,
2694 arg_userns_mode != USER_NAMESPACE_NO,
2695 arg_uid_shift,
2696 arg_uid_range,
2697 arg_selinux_context);
2698 if (r < 0)
2699 return r;
2700
2701 r = setup_volatile_state(
2702 directory,
2703 arg_volatile_mode,
2704 arg_userns_mode != USER_NAMESPACE_NO,
2705 arg_uid_shift,
2706 arg_uid_range,
2707 arg_selinux_context);
2708 if (r < 0)
2709 return r;
2710
2711 /* Mark everything as shared so our mounts get propagated down. This is
2712 * required to make new bind mounts available in systemd services
2713 * inside the containter that create a new mount namespace.
2714 * See https://github.com/systemd/systemd/issues/3860
2715 * Further submounts (such as /dev) done after this will inherit the
2716 * shared propagation mode. */
2717 r = mount_verbose(LOG_ERR, NULL, directory, NULL, MS_SHARED|MS_REC, NULL);
2718 if (r < 0)
2719 return r;
2720
2721 r = recursive_chown(directory, arg_uid_shift, arg_uid_range);
2722 if (r < 0)
2723 return r;
2724
2725 r = base_filesystem_create(directory, arg_uid_shift, (gid_t) arg_uid_shift);
2726 if (r < 0)
2727 return r;
2728
2729 if (arg_read_only) {
2730 r = bind_remount_recursive(directory, true, NULL);
2731 if (r < 0)
2732 return log_error_errno(r, "Failed to make tree read-only: %m");
2733 }
2734
2735 r = mount_all(directory,
2736 arg_mount_settings,
2737 arg_uid_shift,
2738 arg_uid_range,
2739 arg_selinux_apifs_context);
2740 if (r < 0)
2741 return r;
2742
2743 r = copy_devnodes(directory);
2744 if (r < 0)
2745 return r;
2746
2747 dev_setup(directory, arg_uid_shift, arg_uid_shift);
2748
2749 r = setup_pts(directory);
2750 if (r < 0)
2751 return r;
2752
2753 r = setup_propagate(directory);
2754 if (r < 0)
2755 return r;
2756
2757 r = setup_dev_console(directory, console);
2758 if (r < 0)
2759 return r;
2760
2761 r = setup_keyring();
2762 if (r < 0)
2763 return r;
2764
2765 r = setup_seccomp(arg_caps_retain, arg_syscall_whitelist, arg_syscall_blacklist);
2766 if (r < 0)
2767 return r;
2768
2769 r = setup_timezone(directory);
2770 if (r < 0)
2771 return r;
2772
2773 r = setup_resolv_conf(directory);
2774 if (r < 0)
2775 return r;
2776
2777 r = setup_machine_id(directory);
2778 if (r < 0)
2779 return r;
2780
2781 r = setup_journal(directory);
2782 if (r < 0)
2783 return r;
2784
2785 r = mount_custom(
2786 directory,
2787 arg_custom_mounts,
2788 arg_n_custom_mounts,
2789 arg_userns_mode != USER_NAMESPACE_NO,
2790 arg_uid_shift,
2791 arg_uid_range,
2792 arg_selinux_apifs_context);
2793 if (r < 0)
2794 return r;
2795
2796 if (!arg_use_cgns || !cg_ns_supported()) {
2797 r = mount_cgroups(
2798 directory,
2799 arg_unified_cgroup_hierarchy,
2800 arg_userns_mode != USER_NAMESPACE_NO,
2801 arg_uid_shift,
2802 arg_uid_range,
2803 arg_selinux_apifs_context,
2804 false);
2805 if (r < 0)
2806 return r;
2807 }
2808
2809 r = mount_move_root(directory);
2810 if (r < 0)
2811 return log_error_errno(r, "Failed to move root directory: %m");
2812
2813 fd = setup_sd_notify_child();
2814 if (fd < 0)
2815 return fd;
2816
2817 pid = raw_clone(SIGCHLD|CLONE_NEWNS|
2818 arg_clone_ns_flags |
2819 (arg_userns_mode != USER_NAMESPACE_NO ? CLONE_NEWUSER : 0));
2820 if (pid < 0)
2821 return log_error_errno(errno, "Failed to fork inner child: %m");
2822 if (pid == 0) {
2823 pid_socket = safe_close(pid_socket);
2824 uuid_socket = safe_close(uuid_socket);
2825 notify_socket = safe_close(notify_socket);
2826 uid_shift_socket = safe_close(uid_shift_socket);
2827
2828 /* The inner child has all namespaces that are
2829 * requested, so that we all are owned by the user if
2830 * user namespaces are turned on. */
2831
2832 if (arg_network_namespace_path) {
2833 r = namespace_enter(-1, -1, netns_fd, -1, -1);
2834 if (r < 0)
2835 return r;
2836 }
2837
2838 r = inner_child(barrier, directory, secondary, kmsg_socket, rtnl_socket, fds);
2839 if (r < 0)
2840 _exit(EXIT_FAILURE);
2841
2842 _exit(EXIT_SUCCESS);
2843 }
2844
2845 l = send(pid_socket, &pid, sizeof(pid), MSG_NOSIGNAL);
2846 if (l < 0)
2847 return log_error_errno(errno, "Failed to send PID: %m");
2848 if (l != sizeof(pid)) {
2849 log_error("Short write while sending PID.");
2850 return -EIO;
2851 }
2852
2853 l = send(uuid_socket, &arg_uuid, sizeof(arg_uuid), MSG_NOSIGNAL);
2854 if (l < 0)
2855 return log_error_errno(errno, "Failed to send machine ID: %m");
2856 if (l != sizeof(arg_uuid)) {
2857 log_error("Short write while sending machine ID.");
2858 return -EIO;
2859 }
2860
2861 l = send_one_fd(notify_socket, fd, 0);
2862 if (l < 0)
2863 return log_error_errno(errno, "Failed to send notify fd: %m");
2864
2865 pid_socket = safe_close(pid_socket);
2866 uuid_socket = safe_close(uuid_socket);
2867 notify_socket = safe_close(notify_socket);
2868 kmsg_socket = safe_close(kmsg_socket);
2869 rtnl_socket = safe_close(rtnl_socket);
2870 netns_fd = safe_close(netns_fd);
2871
2872 return 0;
2873 }
2874
2875 static int uid_shift_pick(uid_t *shift, LockFile *ret_lock_file) {
2876 bool tried_hashed = false;
2877 unsigned n_tries = 100;
2878 uid_t candidate;
2879 int r;
2880
2881 assert(shift);
2882 assert(ret_lock_file);
2883 assert(arg_userns_mode == USER_NAMESPACE_PICK);
2884 assert(arg_uid_range == 0x10000U);
2885
2886 candidate = *shift;
2887
2888 (void) mkdir("/run/systemd/nspawn-uid", 0755);
2889
2890 for (;;) {
2891 char lock_path[STRLEN("/run/systemd/nspawn-uid/") + DECIMAL_STR_MAX(uid_t) + 1];
2892 _cleanup_release_lock_file_ LockFile lf = LOCK_FILE_INIT;
2893
2894 if (--n_tries <= 0)
2895 return -EBUSY;
2896
2897 if (candidate < CONTAINER_UID_BASE_MIN || candidate > CONTAINER_UID_BASE_MAX)
2898 goto next;
2899 if ((candidate & UINT32_C(0xFFFF)) != 0)
2900 goto next;
2901
2902 xsprintf(lock_path, "/run/systemd/nspawn-uid/" UID_FMT, candidate);
2903 r = make_lock_file(lock_path, LOCK_EX|LOCK_NB, &lf);
2904 if (r == -EBUSY) /* Range already taken by another nspawn instance */
2905 goto next;
2906 if (r < 0)
2907 return r;
2908
2909 /* Make some superficial checks whether the range is currently known in the user database */
2910 if (getpwuid(candidate))
2911 goto next;
2912 if (getpwuid(candidate + UINT32_C(0xFFFE)))
2913 goto next;
2914 if (getgrgid(candidate))
2915 goto next;
2916 if (getgrgid(candidate + UINT32_C(0xFFFE)))
2917 goto next;
2918
2919 *ret_lock_file = lf;
2920 lf = (struct LockFile) LOCK_FILE_INIT;
2921 *shift = candidate;
2922 return 0;
2923
2924 next:
2925 if (arg_machine && !tried_hashed) {
2926 /* Try to hash the base from the container name */
2927
2928 static const uint8_t hash_key[] = {
2929 0xe1, 0x56, 0xe0, 0xf0, 0x4a, 0xf0, 0x41, 0xaf,
2930 0x96, 0x41, 0xcf, 0x41, 0x33, 0x94, 0xff, 0x72
2931 };
2932
2933 candidate = (uid_t) siphash24(arg_machine, strlen(arg_machine), hash_key);
2934
2935 tried_hashed = true;
2936 } else
2937 random_bytes(&candidate, sizeof(candidate));
2938
2939 candidate = (candidate % (CONTAINER_UID_BASE_MAX - CONTAINER_UID_BASE_MIN)) + CONTAINER_UID_BASE_MIN;
2940 candidate &= (uid_t) UINT32_C(0xFFFF0000);
2941 }
2942 }
2943
2944 static int setup_uid_map(pid_t pid) {
2945 char uid_map[STRLEN("/proc//uid_map") + DECIMAL_STR_MAX(uid_t) + 1], line[DECIMAL_STR_MAX(uid_t)*3+3+1];
2946 int r;
2947
2948 assert(pid > 1);
2949
2950 xsprintf(uid_map, "/proc/" PID_FMT "/uid_map", pid);
2951 xsprintf(line, UID_FMT " " UID_FMT " " UID_FMT "\n", 0, arg_uid_shift, arg_uid_range);
2952 r = write_string_file(uid_map, line, 0);
2953 if (r < 0)
2954 return log_error_errno(r, "Failed to write UID map: %m");
2955
2956 /* We always assign the same UID and GID ranges */
2957 xsprintf(uid_map, "/proc/" PID_FMT "/gid_map", pid);
2958 r = write_string_file(uid_map, line, 0);
2959 if (r < 0)
2960 return log_error_errno(r, "Failed to write GID map: %m");
2961
2962 return 0;
2963 }
2964
2965 static int nspawn_dispatch_notify_fd(sd_event_source *source, int fd, uint32_t revents, void *userdata) {
2966 char buf[NOTIFY_BUFFER_MAX+1];
2967 char *p = NULL;
2968 struct iovec iovec = {
2969 .iov_base = buf,
2970 .iov_len = sizeof(buf)-1,
2971 };
2972 union {
2973 struct cmsghdr cmsghdr;
2974 uint8_t buf[CMSG_SPACE(sizeof(struct ucred)) +
2975 CMSG_SPACE(sizeof(int) * NOTIFY_FD_MAX)];
2976 } control = {};
2977 struct msghdr msghdr = {
2978 .msg_iov = &iovec,
2979 .msg_iovlen = 1,
2980 .msg_control = &control,
2981 .msg_controllen = sizeof(control),
2982 };
2983 struct cmsghdr *cmsg;
2984 struct ucred *ucred = NULL;
2985 ssize_t n;
2986 pid_t inner_child_pid;
2987 _cleanup_strv_free_ char **tags = NULL;
2988
2989 assert(userdata);
2990
2991 inner_child_pid = PTR_TO_PID(userdata);
2992
2993 if (revents != EPOLLIN) {
2994 log_warning("Got unexpected poll event for notify fd.");
2995 return 0;
2996 }
2997
2998 n = recvmsg(fd, &msghdr, MSG_DONTWAIT|MSG_CMSG_CLOEXEC);
2999 if (n < 0) {
3000 if (IN_SET(errno, EAGAIN, EINTR))
3001 return 0;
3002
3003 return log_warning_errno(errno, "Couldn't read notification socket: %m");
3004 }
3005 cmsg_close_all(&msghdr);
3006
3007 CMSG_FOREACH(cmsg, &msghdr) {
3008 if (cmsg->cmsg_level == SOL_SOCKET &&
3009 cmsg->cmsg_type == SCM_CREDENTIALS &&
3010 cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred))) {
3011
3012 ucred = (struct ucred*) CMSG_DATA(cmsg);
3013 }
3014 }
3015
3016 if (!ucred || ucred->pid != inner_child_pid) {
3017 log_debug("Received notify message without valid credentials. Ignoring.");
3018 return 0;
3019 }
3020
3021 if ((size_t) n >= sizeof(buf)) {
3022 log_warning("Received notify message exceeded maximum size. Ignoring.");
3023 return 0;
3024 }
3025
3026 buf[n] = 0;
3027 tags = strv_split(buf, "\n\r");
3028 if (!tags)
3029 return log_oom();
3030
3031 if (strv_find(tags, "READY=1"))
3032 sd_notifyf(false, "READY=1\n");
3033
3034 p = strv_find_startswith(tags, "STATUS=");
3035 if (p)
3036 sd_notifyf(false, "STATUS=Container running: %s", p);
3037
3038 return 0;
3039 }
3040
3041 static int setup_sd_notify_parent(sd_event *event, int fd, pid_t *inner_child_pid, sd_event_source **notify_event_source) {
3042 int r;
3043
3044 r = sd_event_add_io(event, notify_event_source, fd, EPOLLIN, nspawn_dispatch_notify_fd, inner_child_pid);
3045 if (r < 0)
3046 return log_error_errno(r, "Failed to allocate notify event source: %m");
3047
3048 (void) sd_event_source_set_description(*notify_event_source, "nspawn-notify");
3049
3050 return 0;
3051 }
3052
3053 static int load_settings(void) {
3054 _cleanup_(settings_freep) Settings *settings = NULL;
3055 _cleanup_fclose_ FILE *f = NULL;
3056 _cleanup_free_ char *p = NULL;
3057 const char *fn, *i;
3058 int r;
3059
3060 /* If all settings are masked, there's no point in looking for
3061 * the settings file */
3062 if ((arg_settings_mask & _SETTINGS_MASK_ALL) == _SETTINGS_MASK_ALL)
3063 return 0;
3064
3065 fn = strjoina(arg_machine, ".nspawn");
3066
3067 /* We first look in the admin's directories in /etc and /run */
3068 FOREACH_STRING(i, "/etc/systemd/nspawn", "/run/systemd/nspawn") {
3069 _cleanup_free_ char *j = NULL;
3070
3071 j = strjoin(i, "/", fn);
3072 if (!j)
3073 return log_oom();
3074
3075 f = fopen(j, "re");
3076 if (f) {
3077 p = TAKE_PTR(j);
3078
3079 /* By default, we trust configuration from /etc and /run */
3080 if (arg_settings_trusted < 0)
3081 arg_settings_trusted = true;
3082
3083 break;
3084 }
3085
3086 if (errno != ENOENT)
3087 return log_error_errno(errno, "Failed to open %s: %m", j);
3088 }
3089
3090 if (!f) {
3091 /* After that, let's look for a file next to the
3092 * actual image we shall boot. */
3093
3094 if (arg_image) {
3095 p = file_in_same_dir(arg_image, fn);
3096 if (!p)
3097 return log_oom();
3098 } else if (arg_directory) {
3099 p = file_in_same_dir(arg_directory, fn);
3100 if (!p)
3101 return log_oom();
3102 }
3103
3104 if (p) {
3105 f = fopen(p, "re");
3106 if (!f && errno != ENOENT)
3107 return log_error_errno(errno, "Failed to open %s: %m", p);
3108
3109 /* By default, we do not trust configuration from /var/lib/machines */
3110 if (arg_settings_trusted < 0)
3111 arg_settings_trusted = false;
3112 }
3113 }
3114
3115 if (!f)
3116 return 0;
3117
3118 log_debug("Settings are trusted: %s", yes_no(arg_settings_trusted));
3119
3120 r = settings_load(f, p, &settings);
3121 if (r < 0)
3122 return r;
3123
3124 /* Copy over bits from the settings, unless they have been
3125 * explicitly masked by command line switches. */
3126
3127 if ((arg_settings_mask & SETTING_START_MODE) == 0 &&
3128 settings->start_mode >= 0) {
3129 arg_start_mode = settings->start_mode;
3130
3131 strv_free(arg_parameters);
3132 arg_parameters = TAKE_PTR(settings->parameters);
3133 }
3134
3135 if ((arg_settings_mask & SETTING_PIVOT_ROOT) == 0 &&
3136 settings->pivot_root_new) {
3137 free_and_replace(arg_pivot_root_new, settings->pivot_root_new);
3138 free_and_replace(arg_pivot_root_old, settings->pivot_root_old);
3139 }
3140
3141 if ((arg_settings_mask & SETTING_WORKING_DIRECTORY) == 0 &&
3142 settings->working_directory)
3143 free_and_replace(arg_chdir, settings->working_directory);
3144
3145 if ((arg_settings_mask & SETTING_ENVIRONMENT) == 0 &&
3146 settings->environment) {
3147 strv_free(arg_setenv);
3148 arg_setenv = TAKE_PTR(settings->environment);
3149 }
3150
3151 if ((arg_settings_mask & SETTING_USER) == 0 &&
3152 settings->user)
3153 free_and_replace(arg_user, settings->user);
3154
3155 if ((arg_settings_mask & SETTING_CAPABILITY) == 0) {
3156 uint64_t plus;
3157
3158 plus = settings->capability;
3159 if (settings_private_network(settings))
3160 plus |= (1ULL << CAP_NET_ADMIN);
3161
3162 if (!arg_settings_trusted && plus != 0) {
3163 if (settings->capability != 0)
3164 log_warning("Ignoring Capability= setting, file %s is not trusted.", p);
3165 } else
3166 arg_caps_retain |= plus;
3167
3168 arg_caps_retain &= ~settings->drop_capability;
3169 }
3170
3171 if ((arg_settings_mask & SETTING_KILL_SIGNAL) == 0 &&
3172 settings->kill_signal > 0)
3173 arg_kill_signal = settings->kill_signal;
3174
3175 if ((arg_settings_mask & SETTING_PERSONALITY) == 0 &&
3176 settings->personality != PERSONALITY_INVALID)
3177 arg_personality = settings->personality;
3178
3179 if ((arg_settings_mask & SETTING_MACHINE_ID) == 0 &&
3180 !sd_id128_is_null(settings->machine_id)) {
3181
3182 if (!arg_settings_trusted)
3183 log_warning("Ignoring MachineID= setting, file %s is not trusted.", p);
3184 else
3185 arg_uuid = settings->machine_id;
3186 }
3187
3188 if ((arg_settings_mask & SETTING_READ_ONLY) == 0 &&
3189 settings->read_only >= 0)
3190 arg_read_only = settings->read_only;
3191
3192 if ((arg_settings_mask & SETTING_VOLATILE_MODE) == 0 &&
3193 settings->volatile_mode != _VOLATILE_MODE_INVALID)
3194 arg_volatile_mode = settings->volatile_mode;
3195
3196 if ((arg_settings_mask & SETTING_CUSTOM_MOUNTS) == 0 &&
3197 settings->n_custom_mounts > 0) {
3198
3199 if (!arg_settings_trusted)
3200 log_warning("Ignoring TemporaryFileSystem=, Bind= and BindReadOnly= settings, file %s is not trusted.", p);
3201 else {
3202 custom_mount_free_all(arg_custom_mounts, arg_n_custom_mounts);
3203 arg_custom_mounts = TAKE_PTR(settings->custom_mounts);
3204 arg_n_custom_mounts = settings->n_custom_mounts;
3205 settings->n_custom_mounts = 0;
3206 }
3207 }
3208
3209 if ((arg_settings_mask & SETTING_NETWORK) == 0 &&
3210 (settings->private_network >= 0 ||
3211 settings->network_veth >= 0 ||
3212 settings->network_bridge ||
3213 settings->network_zone ||
3214 settings->network_interfaces ||
3215 settings->network_macvlan ||
3216 settings->network_ipvlan ||
3217 settings->network_veth_extra)) {
3218
3219 if (!arg_settings_trusted)
3220 log_warning("Ignoring network settings, file %s is not trusted.", p);
3221 else {
3222 arg_network_veth = settings_network_veth(settings);
3223 arg_private_network = settings_private_network(settings);
3224
3225 strv_free(arg_network_interfaces);
3226 arg_network_interfaces = TAKE_PTR(settings->network_interfaces);
3227
3228 strv_free(arg_network_macvlan);
3229 arg_network_macvlan = TAKE_PTR(settings->network_macvlan);
3230
3231 strv_free(arg_network_ipvlan);
3232 arg_network_ipvlan = TAKE_PTR(settings->network_ipvlan);
3233
3234 strv_free(arg_network_veth_extra);
3235 arg_network_veth_extra = TAKE_PTR(settings->network_veth_extra);
3236
3237 free_and_replace(arg_network_bridge, settings->network_bridge);
3238 free_and_replace(arg_network_zone, settings->network_zone);
3239 }
3240 }
3241
3242 if ((arg_settings_mask & SETTING_EXPOSE_PORTS) == 0 &&
3243 settings->expose_ports) {
3244
3245 if (!arg_settings_trusted)
3246 log_warning("Ignoring Port= setting, file %s is not trusted.", p);
3247 else {
3248 expose_port_free_all(arg_expose_ports);
3249 arg_expose_ports = TAKE_PTR(settings->expose_ports);
3250 }
3251 }
3252
3253 if ((arg_settings_mask & SETTING_USERNS) == 0 &&
3254 settings->userns_mode != _USER_NAMESPACE_MODE_INVALID) {
3255
3256 if (!arg_settings_trusted)
3257 log_warning("Ignoring PrivateUsers= and PrivateUsersChown= settings, file %s is not trusted.", p);
3258 else {
3259 arg_userns_mode = settings->userns_mode;
3260 arg_uid_shift = settings->uid_shift;
3261 arg_uid_range = settings->uid_range;
3262 arg_userns_chown = settings->userns_chown;
3263 }
3264 }
3265
3266 if ((arg_settings_mask & SETTING_NOTIFY_READY) == 0)
3267 arg_notify_ready = settings->notify_ready;
3268
3269 if ((arg_settings_mask & SETTING_SYSCALL_FILTER) == 0) {
3270
3271 if (!arg_settings_trusted && !strv_isempty(arg_syscall_whitelist))
3272 log_warning("Ignoring SystemCallFilter= settings, file %s is not trusted.", p);
3273 else {
3274 strv_free(arg_syscall_whitelist);
3275 strv_free(arg_syscall_blacklist);
3276
3277 arg_syscall_whitelist = TAKE_PTR(settings->syscall_whitelist);
3278 arg_syscall_blacklist = TAKE_PTR(settings->syscall_blacklist);
3279 }
3280 }
3281
3282 return 0;
3283 }
3284
3285 static int run(int master,
3286 const char* console,
3287 DissectedImage *dissected_image,
3288 bool interactive,
3289 bool secondary,
3290 FDSet *fds,
3291 char veth_name[IFNAMSIZ], bool *veth_created,
3292 union in_addr_union *exposed,
3293 pid_t *pid, int *ret) {
3294
3295 static const struct sigaction sa = {
3296 .sa_handler = nop_signal_handler,
3297 .sa_flags = SA_NOCLDSTOP|SA_RESTART,
3298 };
3299
3300 _cleanup_release_lock_file_ LockFile uid_shift_lock = LOCK_FILE_INIT;
3301 _cleanup_close_ int etc_passwd_lock = -1;
3302 _cleanup_close_pair_ int
3303 kmsg_socket_pair[2] = { -1, -1 },
3304 rtnl_socket_pair[2] = { -1, -1 },
3305 pid_socket_pair[2] = { -1, -1 },
3306 uuid_socket_pair[2] = { -1, -1 },
3307 notify_socket_pair[2] = { -1, -1 },
3308 uid_shift_socket_pair[2] = { -1, -1 },
3309 unified_cgroup_hierarchy_socket_pair[2] = { -1, -1};
3310
3311 _cleanup_close_ int notify_socket= -1;
3312 _cleanup_(barrier_destroy) Barrier barrier = BARRIER_NULL;
3313 _cleanup_(sd_event_source_unrefp) sd_event_source *notify_event_source = NULL;
3314 _cleanup_(sd_event_unrefp) sd_event *event = NULL;
3315 _cleanup_(pty_forward_freep) PTYForward *forward = NULL;
3316 _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL;
3317 _cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL;
3318 ContainerStatus container_status = 0;
3319 char last_char = 0;
3320 int ifi = 0, r;
3321 ssize_t l;
3322 sigset_t mask_chld;
3323 _cleanup_close_ int netns_fd = -1;
3324
3325 assert_se(sigemptyset(&mask_chld) == 0);
3326 assert_se(sigaddset(&mask_chld, SIGCHLD) == 0);
3327
3328 if (arg_userns_mode == USER_NAMESPACE_PICK) {
3329 /* When we shall pick the UID/GID range, let's first lock /etc/passwd, so that we can safely
3330 * check with getpwuid() if the specific user already exists. Note that /etc might be
3331 * read-only, in which case this will fail with EROFS. But that's really OK, as in that case we
3332 * can be reasonably sure that no users are going to be added. Note that getpwuid() checks are
3333 * really just an extra safety net. We kinda assume that the UID range we allocate from is
3334 * really ours. */
3335
3336 etc_passwd_lock = take_etc_passwd_lock(NULL);
3337 if (etc_passwd_lock < 0 && etc_passwd_lock != -EROFS)
3338 return log_error_errno(etc_passwd_lock, "Failed to take /etc/passwd lock: %m");
3339 }
3340
3341 r = barrier_create(&barrier);
3342 if (r < 0)
3343 return log_error_errno(r, "Cannot initialize IPC barrier: %m");
3344
3345 if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, kmsg_socket_pair) < 0)
3346 return log_error_errno(errno, "Failed to create kmsg socket pair: %m");
3347
3348 if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, rtnl_socket_pair) < 0)
3349 return log_error_errno(errno, "Failed to create rtnl socket pair: %m");
3350
3351 if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, pid_socket_pair) < 0)
3352 return log_error_errno(errno, "Failed to create pid socket pair: %m");
3353
3354 if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, uuid_socket_pair) < 0)
3355 return log_error_errno(errno, "Failed to create id socket pair: %m");
3356
3357 if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, notify_socket_pair) < 0)
3358 return log_error_errno(errno, "Failed to create notify socket pair: %m");
3359
3360 if (arg_userns_mode != USER_NAMESPACE_NO)
3361 if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, uid_shift_socket_pair) < 0)
3362 return log_error_errno(errno, "Failed to create uid shift socket pair: %m");
3363
3364 if (arg_unified_cgroup_hierarchy == CGROUP_UNIFIED_UNKNOWN)
3365 if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, unified_cgroup_hierarchy_socket_pair) < 0)
3366 return log_error_errno(errno, "Failed to create unified cgroup socket pair: %m");
3367
3368 /* Child can be killed before execv(), so handle SIGCHLD in order to interrupt
3369 * parent's blocking calls and give it a chance to call wait() and terminate. */
3370 r = sigprocmask(SIG_UNBLOCK, &mask_chld, NULL);
3371 if (r < 0)
3372 return log_error_errno(errno, "Failed to change the signal mask: %m");
3373
3374 r = sigaction(SIGCHLD, &sa, NULL);
3375 if (r < 0)
3376 return log_error_errno(errno, "Failed to install SIGCHLD handler: %m");
3377
3378 if (arg_network_namespace_path) {
3379 netns_fd = open(arg_network_namespace_path, O_RDONLY|O_NOCTTY|O_CLOEXEC);
3380 if (netns_fd < 0)
3381 return log_error_errno(errno, "Cannot open file %s: %m", arg_network_namespace_path);
3382
3383 r = fd_is_network_ns(netns_fd);
3384 if (r < 0 && r != -ENOTTY)
3385 return log_error_errno(r, "Failed to check %s fs type: %m", arg_network_namespace_path);
3386 if (r == 0) {
3387 log_error("Path %s doesn't refer to a network namespace", arg_network_namespace_path);
3388 return -EINVAL;
3389 }
3390 }
3391
3392 *pid = raw_clone(SIGCHLD|CLONE_NEWNS);
3393 if (*pid < 0)
3394 return log_error_errno(errno, "clone() failed%s: %m",
3395 errno == EINVAL ?
3396 ", do you have namespace support enabled in your kernel? (You need UTS, IPC, PID and NET namespacing built in)" : "");
3397
3398 if (*pid == 0) {
3399 /* The outer child only has a file system namespace. */
3400 barrier_set_role(&barrier, BARRIER_CHILD);
3401
3402 master = safe_close(master);
3403
3404 kmsg_socket_pair[0] = safe_close(kmsg_socket_pair[0]);
3405 rtnl_socket_pair[0] = safe_close(rtnl_socket_pair[0]);
3406 pid_socket_pair[0] = safe_close(pid_socket_pair[0]);
3407 uuid_socket_pair[0] = safe_close(uuid_socket_pair[0]);
3408 notify_socket_pair[0] = safe_close(notify_socket_pair[0]);
3409 uid_shift_socket_pair[0] = safe_close(uid_shift_socket_pair[0]);
3410 unified_cgroup_hierarchy_socket_pair[0] = safe_close(unified_cgroup_hierarchy_socket_pair[0]);
3411
3412 (void) reset_all_signal_handlers();
3413 (void) reset_signal_mask();
3414
3415 r = outer_child(&barrier,
3416 arg_directory,
3417 console,
3418 dissected_image,
3419 interactive,
3420 secondary,
3421 pid_socket_pair[1],
3422 uuid_socket_pair[1],
3423 notify_socket_pair[1],
3424 kmsg_socket_pair[1],
3425 rtnl_socket_pair[1],
3426 uid_shift_socket_pair[1],
3427 unified_cgroup_hierarchy_socket_pair[1],
3428 fds,
3429 netns_fd);
3430 if (r < 0)
3431 _exit(EXIT_FAILURE);
3432
3433 _exit(EXIT_SUCCESS);
3434 }
3435
3436 barrier_set_role(&barrier, BARRIER_PARENT);
3437
3438 fds = fdset_free(fds);
3439
3440 kmsg_socket_pair[1] = safe_close(kmsg_socket_pair[1]);
3441 rtnl_socket_pair[1] = safe_close(rtnl_socket_pair[1]);
3442 pid_socket_pair[1] = safe_close(pid_socket_pair[1]);
3443 uuid_socket_pair[1] = safe_close(uuid_socket_pair[1]);
3444 notify_socket_pair[1] = safe_close(notify_socket_pair[1]);
3445 uid_shift_socket_pair[1] = safe_close(uid_shift_socket_pair[1]);
3446 unified_cgroup_hierarchy_socket_pair[1] = safe_close(unified_cgroup_hierarchy_socket_pair[1]);
3447
3448 if (arg_userns_mode != USER_NAMESPACE_NO) {
3449 /* The child just let us know the UID shift it might have read from the image. */
3450 l = recv(uid_shift_socket_pair[0], &arg_uid_shift, sizeof arg_uid_shift, 0);
3451 if (l < 0)
3452 return log_error_errno(errno, "Failed to read UID shift: %m");
3453 if (l != sizeof arg_uid_shift) {
3454 log_error("Short read while reading UID shift.");
3455 return -EIO;
3456 }
3457
3458 if (arg_userns_mode == USER_NAMESPACE_PICK) {
3459 /* If we are supposed to pick the UID shift, let's try to use the shift read from the
3460 * image, but if that's already in use, pick a new one, and report back to the child,
3461 * which one we now picked. */
3462
3463 r = uid_shift_pick(&arg_uid_shift, &uid_shift_lock);
3464 if (r < 0)
3465 return log_error_errno(r, "Failed to pick suitable UID/GID range: %m");
3466
3467 l = send(uid_shift_socket_pair[0], &arg_uid_shift, sizeof arg_uid_shift, MSG_NOSIGNAL);
3468 if (l < 0)
3469 return log_error_errno(errno, "Failed to send UID shift: %m");
3470 if (l != sizeof arg_uid_shift) {
3471 log_error("Short write while writing UID shift.");
3472 return -EIO;
3473 }
3474 }
3475 }
3476
3477 if (arg_unified_cgroup_hierarchy == CGROUP_UNIFIED_UNKNOWN) {
3478 /* The child let us know the support cgroup mode it might have read from the image. */
3479 l = recv(unified_cgroup_hierarchy_socket_pair[0], &arg_unified_cgroup_hierarchy, sizeof(arg_unified_cgroup_hierarchy), 0);
3480 if (l < 0)
3481 return log_error_errno(errno, "Failed to read cgroup mode: %m");
3482 if (l != sizeof(arg_unified_cgroup_hierarchy)) {
3483 log_error("Short read while reading cgroup mode.");
3484 return -EIO;
3485 }
3486 }
3487
3488 /* Wait for the outer child. */
3489 r = wait_for_terminate_and_check("(sd-namespace)", *pid, WAIT_LOG_ABNORMAL);
3490 if (r < 0)
3491 return r;
3492 if (r != EXIT_SUCCESS)
3493 return -EIO;
3494
3495 /* And now retrieve the PID of the inner child. */
3496 l = recv(pid_socket_pair[0], pid, sizeof *pid, 0);
3497 if (l < 0)
3498 return log_error_errno(errno, "Failed to read inner child PID: %m");
3499 if (l != sizeof *pid) {
3500 log_error("Short read while reading inner child PID.");
3501 return -EIO;
3502 }
3503
3504 /* We also retrieve container UUID in case it was generated by outer child */
3505 l = recv(uuid_socket_pair[0], &arg_uuid, sizeof arg_uuid, 0);
3506 if (l < 0)
3507 return log_error_errno(errno, "Failed to read container machine ID: %m");
3508 if (l != sizeof(arg_uuid)) {
3509 log_error("Short read while reading container machined ID.");
3510 return -EIO;
3511 }
3512
3513 /* We also retrieve the socket used for notifications generated by outer child */
3514 notify_socket = receive_one_fd(notify_socket_pair[0], 0);
3515 if (notify_socket < 0)
3516 return log_error_errno(notify_socket,
3517 "Failed to receive notification socket from the outer child: %m");
3518
3519 log_debug("Init process invoked as PID "PID_FMT, *pid);
3520
3521 if (arg_userns_mode != USER_NAMESPACE_NO) {
3522 if (!barrier_place_and_sync(&barrier)) { /* #1 */
3523 log_error("Child died too early.");
3524 return -ESRCH;
3525 }
3526
3527 r = setup_uid_map(*pid);
3528 if (r < 0)
3529 return r;
3530
3531 (void) barrier_place(&barrier); /* #2 */
3532 }
3533
3534 if (arg_private_network) {
3535
3536 r = move_network_interfaces(*pid, arg_network_interfaces);
3537 if (r < 0)
3538 return r;
3539
3540 if (arg_network_veth) {
3541 r = setup_veth(arg_machine, *pid, veth_name,
3542 arg_network_bridge || arg_network_zone);
3543 if (r < 0)
3544 return r;
3545 else if (r > 0)
3546 ifi = r;
3547
3548 if (arg_network_bridge) {
3549 /* Add the interface to a bridge */
3550 r = setup_bridge(veth_name, arg_network_bridge, false);
3551 if (r < 0)
3552 return r;
3553 if (r > 0)
3554 ifi = r;
3555 } else if (arg_network_zone) {
3556 /* Add the interface to a bridge, possibly creating it */
3557 r = setup_bridge(veth_name, arg_network_zone, true);
3558 if (r < 0)
3559 return r;
3560 if (r > 0)
3561 ifi = r;
3562 }
3563 }
3564
3565 r = setup_veth_extra(arg_machine, *pid, arg_network_veth_extra);
3566 if (r < 0)
3567 return r;
3568
3569 /* We created the primary and extra veth links now; let's remember this, so that we know to
3570 remove them later on. Note that we don't bother with removing veth links that were created
3571 here when their setup failed half-way, because in that case the kernel should be able to
3572 remove them on its own, since they cannot be referenced by anything yet. */
3573 *veth_created = true;
3574
3575 r = setup_macvlan(arg_machine, *pid, arg_network_macvlan);
3576 if (r < 0)
3577 return r;
3578
3579 r = setup_ipvlan(arg_machine, *pid, arg_network_ipvlan);
3580 if (r < 0)
3581 return r;
3582 }
3583
3584 if (arg_register || !arg_keep_unit) {
3585 r = sd_bus_default_system(&bus);
3586 if (r < 0)
3587 return log_error_errno(r, "Failed to open system bus: %m");
3588 }
3589
3590 if (!arg_keep_unit) {
3591 /* When a new scope is created for this container, then we'll be registered as its controller, in which
3592 * case PID 1 will send us a friendly RequestStop signal, when it is asked to terminate the
3593 * scope. Let's hook into that, and cleanly shut down the container, and print a friendly message. */
3594
3595 r = sd_bus_match_signal_async(
3596 bus,
3597 NULL,
3598 "org.freedesktop.systemd1",
3599 NULL,
3600 "org.freedesktop.systemd1.Scope",
3601 "RequestStop",
3602 on_request_stop, NULL, PID_TO_PTR(*pid));
3603 if (r < 0)
3604 return log_error_errno(r, "Failed to request RequestStop match: %m");
3605 }
3606
3607 if (arg_register) {
3608
3609 r = register_machine(
3610 bus,
3611 arg_machine,
3612 *pid,
3613 arg_directory,
3614 arg_uuid,
3615 ifi,
3616 arg_slice,
3617 arg_custom_mounts, arg_n_custom_mounts,
3618 arg_kill_signal,
3619 arg_property,
3620 arg_keep_unit,
3621 arg_container_service_name);
3622 if (r < 0)
3623 return r;
3624
3625 } else if (!arg_keep_unit) {
3626
3627 r = allocate_scope(
3628 bus,
3629 arg_machine,
3630 *pid,
3631 arg_slice,
3632 arg_custom_mounts, arg_n_custom_mounts,
3633 arg_kill_signal,
3634 arg_property);
3635 if (r < 0)
3636 return r;
3637
3638 } else if (arg_slice || arg_property)
3639 log_notice("Machine and scope registration turned off, --slice= and --property= settings will have no effect.");
3640
3641 r = sync_cgroup(*pid, arg_unified_cgroup_hierarchy, arg_uid_shift);
3642 if (r < 0)
3643 return r;
3644
3645 if (arg_keep_unit) {
3646 r = create_subcgroup(*pid, arg_unified_cgroup_hierarchy);
3647 if (r < 0)
3648 return r;
3649 }
3650
3651 r = chown_cgroup(*pid, arg_unified_cgroup_hierarchy, arg_uid_shift);
3652 if (r < 0)
3653 return r;
3654
3655 /* Notify the child that the parent is ready with all
3656 * its setup (including cgroup-ification), and that
3657 * the child can now hand over control to the code to
3658 * run inside the container. */
3659 (void) barrier_place(&barrier); /* #3 */
3660
3661 /* Block SIGCHLD here, before notifying child.
3662 * process_pty() will handle it with the other signals. */
3663 assert_se(sigprocmask(SIG_BLOCK, &mask_chld, NULL) >= 0);
3664
3665 /* Reset signal to default */
3666 r = default_signals(SIGCHLD, -1);
3667 if (r < 0)
3668 return log_error_errno(r, "Failed to reset SIGCHLD: %m");
3669
3670 r = sd_event_new(&event);
3671 if (r < 0)
3672 return log_error_errno(r, "Failed to get default event source: %m");
3673
3674 (void) sd_event_set_watchdog(event, true);
3675
3676 if (bus) {
3677 r = sd_bus_attach_event(bus, event, 0);
3678 if (r < 0)
3679 return log_error_errno(r, "Failed to attach bus to event loop: %m");
3680 }
3681
3682 r = setup_sd_notify_parent(event, notify_socket, PID_TO_PTR(*pid), &notify_event_source);
3683 if (r < 0)
3684 return r;
3685
3686 /* Let the child know that we are ready and wait that the child is completely ready now. */
3687 if (!barrier_place_and_sync(&barrier)) { /* #4 */
3688 log_error("Child died too early.");
3689 return -ESRCH;
3690 }
3691
3692 /* At this point we have made use of the UID we picked, and thus nss-mymachines
3693 * will make them appear in getpwuid(), thus we can release the /etc/passwd lock. */
3694 etc_passwd_lock = safe_close(etc_passwd_lock);
3695
3696 sd_notifyf(false,
3697 "STATUS=Container running.\n"
3698 "X_NSPAWN_LEADER_PID=" PID_FMT, *pid);
3699 if (!arg_notify_ready)
3700 sd_notify(false, "READY=1\n");
3701
3702 if (arg_kill_signal > 0) {
3703 /* Try to kill the init system on SIGINT or SIGTERM */
3704 sd_event_add_signal(event, NULL, SIGINT, on_orderly_shutdown, PID_TO_PTR(*pid));
3705 sd_event_add_signal(event, NULL, SIGTERM, on_orderly_shutdown, PID_TO_PTR(*pid));
3706 } else {
3707 /* Immediately exit */
3708 sd_event_add_signal(event, NULL, SIGINT, NULL, NULL);
3709 sd_event_add_signal(event, NULL, SIGTERM, NULL, NULL);
3710 }
3711
3712 /* Exit when the child exits */
3713 sd_event_add_signal(event, NULL, SIGCHLD, on_sigchld, PID_TO_PTR(*pid));
3714
3715 if (arg_expose_ports) {
3716 r = expose_port_watch_rtnl(event, rtnl_socket_pair[0], on_address_change, exposed, &rtnl);
3717 if (r < 0)
3718 return r;
3719
3720 (void) expose_port_execute(rtnl, arg_expose_ports, exposed);
3721 }
3722
3723 rtnl_socket_pair[0] = safe_close(rtnl_socket_pair[0]);
3724
3725 r = pty_forward_new(event, master,
3726 PTY_FORWARD_IGNORE_VHANGUP | (interactive ? 0 : PTY_FORWARD_READ_ONLY),
3727 &forward);
3728 if (r < 0)
3729 return log_error_errno(r, "Failed to create PTY forwarder: %m");
3730
3731 r = sd_event_loop(event);
3732 if (r < 0)
3733 return log_error_errno(r, "Failed to run event loop: %m");
3734
3735 pty_forward_get_last_char(forward, &last_char);
3736
3737 forward = pty_forward_free(forward);
3738
3739 if (!arg_quiet && last_char != '\n')
3740 putc('\n', stdout);
3741
3742 /* Kill if it is not dead yet anyway */
3743 if (arg_register && !arg_keep_unit && bus)
3744 terminate_machine(bus, *pid);
3745
3746 /* Normally redundant, but better safe than sorry */
3747 (void) kill(*pid, SIGKILL);
3748
3749 r = wait_for_container(*pid, &container_status);
3750 *pid = 0;
3751
3752 if (r < 0)
3753 /* We failed to wait for the container, or the container exited abnormally. */
3754 return r;
3755 if (r > 0 || container_status == CONTAINER_TERMINATED) {
3756 /* r > 0 → The container exited with a non-zero status.
3757 * As a special case, we need to replace 133 with a different value,
3758 * because 133 is special-cased in the service file to reboot the container.
3759 * otherwise → The container exited with zero status and a reboot was not requested.
3760 */
3761 if (r == EXIT_FORCE_RESTART)
3762 r = EXIT_FAILURE; /* replace 133 with the general failure code */
3763 *ret = r;
3764 return 0; /* finito */
3765 }
3766
3767 /* CONTAINER_REBOOTED, loop again */
3768
3769 if (arg_keep_unit) {
3770 /* Special handling if we are running as a service: instead of simply
3771 * restarting the machine we want to restart the entire service, so let's
3772 * inform systemd about this with the special exit code 133. The service
3773 * file uses RestartForceExitStatus=133 so that this results in a full
3774 * nspawn restart. This is necessary since we might have cgroup parameters
3775 * set we want to have flushed out. */
3776 *ret = EXIT_FORCE_RESTART;
3777 return 0; /* finito */
3778 }
3779
3780 expose_port_flush(arg_expose_ports, exposed);
3781
3782 (void) remove_veth_links(veth_name, arg_network_veth_extra);
3783 *veth_created = false;
3784 return 1; /* loop again */
3785 }
3786
3787 int main(int argc, char *argv[]) {
3788
3789 _cleanup_free_ char *console = NULL;
3790 _cleanup_close_ int master = -1;
3791 _cleanup_fdset_free_ FDSet *fds = NULL;
3792 int r, n_fd_passed, ret = EXIT_SUCCESS;
3793 char veth_name[IFNAMSIZ] = "";
3794 bool secondary = false, remove_directory = false, remove_image = false;
3795 pid_t pid = 0;
3796 union in_addr_union exposed = {};
3797 _cleanup_release_lock_file_ LockFile tree_global_lock = LOCK_FILE_INIT, tree_local_lock = LOCK_FILE_INIT;
3798 bool interactive, veth_created = false, remove_tmprootdir = false;
3799 char tmprootdir[] = "/tmp/nspawn-root-XXXXXX";
3800 _cleanup_(loop_device_unrefp) LoopDevice *loop = NULL;
3801 _cleanup_(decrypted_image_unrefp) DecryptedImage *decrypted_image = NULL;
3802 _cleanup_(dissected_image_unrefp) DissectedImage *dissected_image = NULL;
3803
3804 log_parse_environment();
3805 log_open();
3806
3807 /* Make sure rename_process() in the stub init process can work */
3808 saved_argv = argv;
3809 saved_argc = argc;
3810
3811 r = parse_argv(argc, argv);
3812 if (r <= 0)
3813 goto finish;
3814
3815 r = must_be_root();
3816 if (r < 0)
3817 goto finish;
3818
3819 r = determine_names();
3820 if (r < 0)
3821 goto finish;
3822
3823 r = load_settings();
3824 if (r < 0)
3825 goto finish;
3826
3827 r = verify_arguments();
3828 if (r < 0)
3829 goto finish;
3830
3831 r = detect_unified_cgroup_hierarchy_from_environment();
3832 if (r < 0)
3833 goto finish;
3834
3835 n_fd_passed = sd_listen_fds(false);
3836 if (n_fd_passed > 0) {
3837 r = fdset_new_listen_fds(&fds, false);
3838 if (r < 0) {
3839 log_error_errno(r, "Failed to collect file descriptors: %m");
3840 goto finish;
3841 }
3842 }
3843
3844 if (arg_directory) {
3845 assert(!arg_image);
3846
3847 if (path_equal(arg_directory, "/") && !arg_ephemeral) {
3848 log_error("Spawning container on root directory is not supported. Consider using --ephemeral.");
3849 r = -EINVAL;
3850 goto finish;
3851 }
3852
3853 if (arg_ephemeral) {
3854 _cleanup_free_ char *np = NULL;
3855
3856 r = chase_symlinks_and_update(&arg_directory, 0);
3857 if (r < 0)
3858 goto finish;
3859
3860 /* If the specified path is a mount point we
3861 * generate the new snapshot immediately
3862 * inside it under a random name. However if
3863 * the specified is not a mount point we
3864 * create the new snapshot in the parent
3865 * directory, just next to it. */
3866 r = path_is_mount_point(arg_directory, NULL, 0);
3867 if (r < 0) {
3868 log_error_errno(r, "Failed to determine whether directory %s is mount point: %m", arg_directory);
3869 goto finish;
3870 }
3871 if (r > 0)
3872 r = tempfn_random_child(arg_directory, "machine.", &np);
3873 else
3874 r = tempfn_random(arg_directory, "machine.", &np);
3875 if (r < 0) {
3876 log_error_errno(r, "Failed to generate name for directory snapshot: %m");
3877 goto finish;
3878 }
3879
3880 r = image_path_lock(np, (arg_read_only ? LOCK_SH : LOCK_EX) | LOCK_NB, &tree_global_lock, &tree_local_lock);
3881 if (r < 0) {
3882 log_error_errno(r, "Failed to lock %s: %m", np);
3883 goto finish;
3884 }
3885
3886 r = btrfs_subvol_snapshot(arg_directory, np,
3887 (arg_read_only ? BTRFS_SNAPSHOT_READ_ONLY : 0) |
3888 BTRFS_SNAPSHOT_FALLBACK_COPY |
3889 BTRFS_SNAPSHOT_FALLBACK_DIRECTORY |
3890 BTRFS_SNAPSHOT_RECURSIVE |
3891 BTRFS_SNAPSHOT_QUOTA);
3892 if (r < 0) {
3893 log_error_errno(r, "Failed to create snapshot %s from %s: %m", np, arg_directory);
3894 goto finish;
3895 }
3896
3897 free_and_replace(arg_directory, np);
3898
3899 remove_directory = true;
3900
3901 } else {
3902 r = chase_symlinks_and_update(&arg_directory, arg_template ? CHASE_NONEXISTENT : 0);
3903 if (r < 0)
3904 goto finish;
3905
3906 r = image_path_lock(arg_directory, (arg_read_only ? LOCK_SH : LOCK_EX) | LOCK_NB, &tree_global_lock, &tree_local_lock);
3907 if (r == -EBUSY) {
3908 log_error_errno(r, "Directory tree %s is currently busy.", arg_directory);
3909 goto finish;
3910 }
3911 if (r < 0) {
3912 log_error_errno(r, "Failed to lock %s: %m", arg_directory);
3913 goto finish;
3914 }
3915
3916 if (arg_template) {
3917 r = chase_symlinks_and_update(&arg_template, 0);
3918 if (r < 0)
3919 goto finish;
3920
3921 r = btrfs_subvol_snapshot(arg_template, arg_directory,
3922 (arg_read_only ? BTRFS_SNAPSHOT_READ_ONLY : 0) |
3923 BTRFS_SNAPSHOT_FALLBACK_COPY |
3924 BTRFS_SNAPSHOT_FALLBACK_DIRECTORY |
3925 BTRFS_SNAPSHOT_FALLBACK_IMMUTABLE |
3926 BTRFS_SNAPSHOT_RECURSIVE |
3927 BTRFS_SNAPSHOT_QUOTA);
3928 if (r == -EEXIST) {
3929 if (!arg_quiet)
3930 log_info("Directory %s already exists, not populating from template %s.", arg_directory, arg_template);
3931 } else if (r < 0) {
3932 log_error_errno(r, "Couldn't create snapshot %s from %s: %m", arg_directory, arg_template);
3933 goto finish;
3934 } else {
3935 if (!arg_quiet)
3936 log_info("Populated %s from template %s.", arg_directory, arg_template);
3937 }
3938 }
3939 }
3940
3941 if (arg_start_mode == START_BOOT) {
3942 if (path_is_os_tree(arg_directory) <= 0) {
3943 log_error("Directory %s doesn't look like an OS root directory (os-release file is missing). Refusing.", arg_directory);
3944 r = -EINVAL;
3945 goto finish;
3946 }
3947 } else {
3948 const char *p;
3949
3950 p = strjoina(arg_directory, "/usr/");
3951 if (laccess(p, F_OK) < 0) {
3952 log_error("Directory %s doesn't look like it has an OS tree. Refusing.", arg_directory);
3953 r = -EINVAL;
3954 goto finish;
3955 }
3956 }
3957
3958 } else {
3959 assert(arg_image);
3960 assert(!arg_template);
3961
3962 r = chase_symlinks_and_update(&arg_image, 0);
3963 if (r < 0)
3964 goto finish;
3965
3966 if (arg_ephemeral) {
3967 _cleanup_free_ char *np = NULL;
3968
3969 r = tempfn_random(arg_image, "machine.", &np);
3970 if (r < 0) {
3971 log_error_errno(r, "Failed to generate name for image snapshot: %m");
3972 goto finish;
3973 }
3974
3975 r = image_path_lock(np, (arg_read_only ? LOCK_SH : LOCK_EX) | LOCK_NB, &tree_global_lock, &tree_local_lock);
3976 if (r < 0) {
3977 r = log_error_errno(r, "Failed to create image lock: %m");
3978 goto finish;
3979 }
3980
3981 r = copy_file(arg_image, np, O_EXCL, arg_read_only ? 0400 : 0600, FS_NOCOW_FL, COPY_REFLINK);
3982 if (r < 0) {
3983 r = log_error_errno(r, "Failed to copy image file: %m");
3984 goto finish;
3985 }
3986
3987 free_and_replace(arg_image, np);
3988
3989 remove_image = true;
3990 } else {
3991 r = image_path_lock(arg_image, (arg_read_only ? LOCK_SH : LOCK_EX) | LOCK_NB, &tree_global_lock, &tree_local_lock);
3992 if (r == -EBUSY) {
3993 r = log_error_errno(r, "Disk image %s is currently busy.", arg_image);
3994 goto finish;
3995 }
3996 if (r < 0) {
3997 r = log_error_errno(r, "Failed to create image lock: %m");
3998 goto finish;
3999 }
4000
4001 if (!arg_root_hash) {
4002 r = root_hash_load(arg_image, &arg_root_hash, &arg_root_hash_size);
4003 if (r < 0) {
4004 log_error_errno(r, "Failed to load root hash file for %s: %m", arg_image);
4005 goto finish;
4006 }
4007 }
4008 }
4009
4010 if (!mkdtemp(tmprootdir)) {
4011 r = log_error_errno(errno, "Failed to create temporary directory: %m");
4012 goto finish;
4013 }
4014
4015 remove_tmprootdir = true;
4016
4017 arg_directory = strdup(tmprootdir);
4018 if (!arg_directory) {
4019 r = log_oom();
4020 goto finish;
4021 }
4022
4023 r = loop_device_make_by_path(arg_image, arg_read_only ? O_RDONLY : O_RDWR, &loop);
4024 if (r < 0) {
4025 log_error_errno(r, "Failed to set up loopback block device: %m");
4026 goto finish;
4027 }
4028
4029 r = dissect_image_and_warn(
4030 loop->fd,
4031 arg_image,
4032 arg_root_hash, arg_root_hash_size,
4033 DISSECT_IMAGE_REQUIRE_ROOT,
4034 &dissected_image);
4035 if (r == -ENOPKG) {
4036 /* dissected_image_and_warn() already printed a brief error message. Extend on that with more details */
4037 log_notice("Note that the disk image needs to\n"
4038 " a) either contain only a single MBR partition of type 0x83 that is marked bootable\n"
4039 " b) or contain a single GPT partition of type 0FC63DAF-8483-4772-8E79-3D69D8477DE4\n"
4040 " c) or follow http://www.freedesktop.org/wiki/Specifications/DiscoverablePartitionsSpec/\n"
4041 " d) or contain a file system without a partition table\n"
4042 "in order to be bootable with systemd-nspawn.");
4043 goto finish;
4044 }
4045 if (r < 0)
4046 goto finish;
4047
4048 if (!arg_root_hash && dissected_image->can_verity)
4049 log_notice("Note: image %s contains verity information, but no root hash specified! Proceeding without integrity checking.", arg_image);
4050
4051 r = dissected_image_decrypt_interactively(dissected_image, NULL, arg_root_hash, arg_root_hash_size, 0, &decrypted_image);
4052 if (r < 0)
4053 goto finish;
4054
4055 /* Now that we mounted the image, let's try to remove it again, if it is ephemeral */
4056 if (remove_image && unlink(arg_image) >= 0)
4057 remove_image = false;
4058 }
4059
4060 r = custom_mount_prepare_all(arg_directory, arg_custom_mounts, arg_n_custom_mounts);
4061 if (r < 0)
4062 goto finish;
4063
4064 interactive =
4065 isatty(STDIN_FILENO) > 0 &&
4066 isatty(STDOUT_FILENO) > 0;
4067
4068 master = posix_openpt(O_RDWR|O_NOCTTY|O_CLOEXEC|O_NDELAY);
4069 if (master < 0) {
4070 r = log_error_errno(errno, "Failed to acquire pseudo tty: %m");
4071 goto finish;
4072 }
4073
4074 r = ptsname_malloc(master, &console);
4075 if (r < 0) {
4076 r = log_error_errno(r, "Failed to determine tty name: %m");
4077 goto finish;
4078 }
4079
4080 if (arg_selinux_apifs_context) {
4081 r = mac_selinux_apply(console, arg_selinux_apifs_context);
4082 if (r < 0)
4083 goto finish;
4084 }
4085
4086 if (unlockpt(master) < 0) {
4087 r = log_error_errno(errno, "Failed to unlock tty: %m");
4088 goto finish;
4089 }
4090
4091 if (!arg_quiet)
4092 log_info("Spawning container %s on %s.\nPress ^] three times within 1s to kill container.",
4093 arg_machine, arg_image ?: arg_directory);
4094
4095 assert_se(sigprocmask_many(SIG_BLOCK, NULL, SIGCHLD, SIGWINCH, SIGTERM, SIGINT, -1) >= 0);
4096
4097 if (prctl(PR_SET_CHILD_SUBREAPER, 1) < 0) {
4098 r = log_error_errno(errno, "Failed to become subreaper: %m");
4099 goto finish;
4100 }
4101
4102 for (;;) {
4103 r = run(master,
4104 console,
4105 dissected_image,
4106 interactive, secondary,
4107 fds,
4108 veth_name, &veth_created,
4109 &exposed,
4110 &pid, &ret);
4111 if (r <= 0)
4112 break;
4113 }
4114
4115 finish:
4116 sd_notify(false,
4117 r == 0 && ret == EXIT_FORCE_RESTART ? "STOPPING=1\nSTATUS=Restarting..." :
4118 "STOPPING=1\nSTATUS=Terminating...");
4119
4120 if (pid > 0)
4121 (void) kill(pid, SIGKILL);
4122
4123 /* Try to flush whatever is still queued in the pty */
4124 if (master >= 0) {
4125 (void) copy_bytes(master, STDOUT_FILENO, (uint64_t) -1, 0);
4126 master = safe_close(master);
4127 }
4128
4129 if (pid > 0)
4130 (void) wait_for_terminate(pid, NULL);
4131
4132 if (remove_directory && arg_directory) {
4133 int k;
4134
4135 k = rm_rf(arg_directory, REMOVE_ROOT|REMOVE_PHYSICAL|REMOVE_SUBVOLUME);
4136 if (k < 0)
4137 log_warning_errno(k, "Cannot remove '%s', ignoring: %m", arg_directory);
4138 }
4139
4140 if (remove_image && arg_image) {
4141 if (unlink(arg_image) < 0)
4142 log_warning_errno(errno, "Can't remove image file '%s', ignoring: %m", arg_image);
4143 }
4144
4145 if (remove_tmprootdir) {
4146 if (rmdir(tmprootdir) < 0)
4147 log_debug_errno(errno, "Can't remove temporary root directory '%s', ignoring: %m", tmprootdir);
4148 }
4149
4150 if (arg_machine) {
4151 const char *p;
4152
4153 p = strjoina("/run/systemd/nspawn/propagate/", arg_machine);
4154 (void) rm_rf(p, REMOVE_ROOT);
4155 }
4156
4157 expose_port_flush(arg_expose_ports, &exposed);
4158
4159 if (veth_created)
4160 (void) remove_veth_links(veth_name, arg_network_veth_extra);
4161 (void) remove_bridge(arg_network_zone);
4162
4163 free(arg_directory);
4164 free(arg_template);
4165 free(arg_image);
4166 free(arg_machine);
4167 free(arg_user);
4168 free(arg_pivot_root_new);
4169 free(arg_pivot_root_old);
4170 free(arg_chdir);
4171 strv_free(arg_setenv);
4172 free(arg_network_bridge);
4173 strv_free(arg_network_interfaces);
4174 strv_free(arg_network_macvlan);
4175 strv_free(arg_network_ipvlan);
4176 strv_free(arg_network_veth_extra);
4177 strv_free(arg_parameters);
4178 custom_mount_free_all(arg_custom_mounts, arg_n_custom_mounts);
4179 expose_port_free_all(arg_expose_ports);
4180 free(arg_root_hash);
4181
4182 return r < 0 ? EXIT_FAILURE : ret;
4183 }
Unnamed repository; edit this file 'description' to name the repository.