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Merge pull request #3476 from brauner/2020-07-05/fixes
[mirror_lxc.git] / src / lxc / conf.c
... / ...
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1/* SPDX-License-Identifier: LGPL-2.1+ */
2
3#ifndef _GNU_SOURCE
4#define _GNU_SOURCE 1
5#endif
6#include <arpa/inet.h>
7#include <dirent.h>
8#include <errno.h>
9#include <fcntl.h>
10#include <grp.h>
11#include <inttypes.h>
12#include <libgen.h>
13#include <linux/loop.h>
14#include <net/if.h>
15#include <netinet/in.h>
16#include <pwd.h>
17#include <stdarg.h>
18#include <stdio.h>
19#include <stdlib.h>
20#include <string.h>
21#include <sys/mman.h>
22#include <sys/mount.h>
23#include <sys/param.h>
24#include <sys/prctl.h>
25#include <sys/sendfile.h>
26#include <sys/socket.h>
27#include <sys/stat.h>
28#include <sys/syscall.h>
29#include <sys/sysmacros.h>
30#include <sys/types.h>
31#include <sys/utsname.h>
32#include <sys/wait.h>
33#include <time.h>
34#include <unistd.h>
35
36#include "af_unix.h"
37#include "caps.h"
38#include "cgroup.h"
39#include "cgroup2_devices.h"
40#include "conf.h"
41#include "config.h"
42#include "confile.h"
43#include "confile_utils.h"
44#include "error.h"
45#include "log.h"
46#include "lsm/lsm.h"
47#include "lxclock.h"
48#include "lxcseccomp.h"
49#include "macro.h"
50#include "memory_utils.h"
51#include "namespace.h"
52#include "network.h"
53#include "parse.h"
54#include "process_utils.h"
55#include "ringbuf.h"
56#include "start.h"
57#include "storage.h"
58#include "storage/overlay.h"
59#include "syscall_wrappers.h"
60#include "terminal.h"
61#include "utils.h"
62#include "uuid.h"
63
64#ifdef MAJOR_IN_MKDEV
65#include <sys/mkdev.h>
66#endif
67
68#ifdef HAVE_STATVFS
69#include <sys/statvfs.h>
70#endif
71
72#if HAVE_PTY_H
73#include <pty.h>
74#else
75#include <../include/openpty.h>
76#endif
77
78#if HAVE_LIBCAP
79#include <sys/capability.h>
80#endif
81
82#if HAVE_SYS_PERSONALITY_H
83#include <sys/personality.h>
84#endif
85
86#ifndef HAVE_STRLCAT
87#include "include/strlcat.h"
88#endif
89
90#if IS_BIONIC
91#include <../include/lxcmntent.h>
92#else
93#include <mntent.h>
94#endif
95
96#if !defined(HAVE_PRLIMIT) && defined(HAVE_PRLIMIT64)
97#include <../include/prlimit.h>
98#endif
99
100lxc_log_define(conf, lxc);
101
102/* The lxc_conf of the container currently being worked on in an API call.
103 * This is used in the error calls.
104 */
105#ifdef HAVE_TLS
106thread_local struct lxc_conf *current_config;
107#else
108struct lxc_conf *current_config;
109#endif
110
111char *lxchook_names[NUM_LXC_HOOKS] = {
112 "pre-start",
113 "pre-mount",
114 "mount",
115 "autodev",
116 "start",
117 "stop",
118 "post-stop",
119 "clone",
120 "destroy",
121 "start-host"
122};
123
124struct mount_opt {
125 char *name;
126 int clear;
127 int flag;
128};
129
130struct caps_opt {
131 char *name;
132 int value;
133};
134
135struct limit_opt {
136 char *name;
137 int value;
138};
139
140static struct mount_opt mount_opt[] = {
141 { "async", 1, MS_SYNCHRONOUS },
142 { "atime", 1, MS_NOATIME },
143 { "bind", 0, MS_BIND },
144 { "defaults", 0, 0 },
145 { "dev", 1, MS_NODEV },
146 { "diratime", 1, MS_NODIRATIME },
147 { "dirsync", 0, MS_DIRSYNC },
148 { "exec", 1, MS_NOEXEC },
149 { "lazytime", 0, MS_LAZYTIME },
150 { "mand", 0, MS_MANDLOCK },
151 { "noatime", 0, MS_NOATIME },
152 { "nodev", 0, MS_NODEV },
153 { "nodiratime", 0, MS_NODIRATIME },
154 { "noexec", 0, MS_NOEXEC },
155 { "nomand", 1, MS_MANDLOCK },
156 { "norelatime", 1, MS_RELATIME },
157 { "nostrictatime", 1, MS_STRICTATIME },
158 { "nosuid", 0, MS_NOSUID },
159 { "rbind", 0, MS_BIND|MS_REC },
160 { "relatime", 0, MS_RELATIME },
161 { "remount", 0, MS_REMOUNT },
162 { "ro", 0, MS_RDONLY },
163 { "rw", 1, MS_RDONLY },
164 { "strictatime", 0, MS_STRICTATIME },
165 { "suid", 1, MS_NOSUID },
166 { "sync", 0, MS_SYNCHRONOUS },
167 { NULL, 0, 0 },
168};
169
170static struct mount_opt propagation_opt[] = {
171 { "private", 0, MS_PRIVATE },
172 { "shared", 0, MS_SHARED },
173 { "slave", 0, MS_SLAVE },
174 { "unbindable", 0, MS_UNBINDABLE },
175 { "rprivate", 0, MS_PRIVATE|MS_REC },
176 { "rshared", 0, MS_SHARED|MS_REC },
177 { "rslave", 0, MS_SLAVE|MS_REC },
178 { "runbindable", 0, MS_UNBINDABLE|MS_REC },
179 { NULL, 0, 0 },
180};
181
182static struct caps_opt caps_opt[] = {
183#if HAVE_LIBCAP
184 { "chown", CAP_CHOWN },
185 { "dac_override", CAP_DAC_OVERRIDE },
186 { "dac_read_search", CAP_DAC_READ_SEARCH },
187 { "fowner", CAP_FOWNER },
188 { "fsetid", CAP_FSETID },
189 { "kill", CAP_KILL },
190 { "setgid", CAP_SETGID },
191 { "setuid", CAP_SETUID },
192 { "setpcap", CAP_SETPCAP },
193 { "linux_immutable", CAP_LINUX_IMMUTABLE },
194 { "net_bind_service", CAP_NET_BIND_SERVICE },
195 { "net_broadcast", CAP_NET_BROADCAST },
196 { "net_admin", CAP_NET_ADMIN },
197 { "net_raw", CAP_NET_RAW },
198 { "ipc_lock", CAP_IPC_LOCK },
199 { "ipc_owner", CAP_IPC_OWNER },
200 { "sys_module", CAP_SYS_MODULE },
201 { "sys_rawio", CAP_SYS_RAWIO },
202 { "sys_chroot", CAP_SYS_CHROOT },
203 { "sys_ptrace", CAP_SYS_PTRACE },
204 { "sys_pacct", CAP_SYS_PACCT },
205 { "sys_admin", CAP_SYS_ADMIN },
206 { "sys_boot", CAP_SYS_BOOT },
207 { "sys_nice", CAP_SYS_NICE },
208 { "sys_resource", CAP_SYS_RESOURCE },
209 { "sys_time", CAP_SYS_TIME },
210 { "sys_tty_config", CAP_SYS_TTY_CONFIG },
211 { "mknod", CAP_MKNOD },
212 { "lease", CAP_LEASE },
213#ifdef CAP_AUDIT_READ
214 { "audit_read", CAP_AUDIT_READ },
215#endif
216#ifdef CAP_AUDIT_WRITE
217 { "audit_write", CAP_AUDIT_WRITE },
218#endif
219#ifdef CAP_AUDIT_CONTROL
220 { "audit_control", CAP_AUDIT_CONTROL },
221#endif
222 { "setfcap", CAP_SETFCAP },
223 { "mac_override", CAP_MAC_OVERRIDE },
224 { "mac_admin", CAP_MAC_ADMIN },
225#ifdef CAP_SYSLOG
226 { "syslog", CAP_SYSLOG },
227#endif
228#ifdef CAP_WAKE_ALARM
229 { "wake_alarm", CAP_WAKE_ALARM },
230#endif
231#ifdef CAP_BLOCK_SUSPEND
232 { "block_suspend", CAP_BLOCK_SUSPEND },
233#endif
234#endif
235};
236
237static struct limit_opt limit_opt[] = {
238#ifdef RLIMIT_AS
239 { "as", RLIMIT_AS },
240#endif
241#ifdef RLIMIT_CORE
242 { "core", RLIMIT_CORE },
243#endif
244#ifdef RLIMIT_CPU
245 { "cpu", RLIMIT_CPU },
246#endif
247#ifdef RLIMIT_DATA
248 { "data", RLIMIT_DATA },
249#endif
250#ifdef RLIMIT_FSIZE
251 { "fsize", RLIMIT_FSIZE },
252#endif
253#ifdef RLIMIT_LOCKS
254 { "locks", RLIMIT_LOCKS },
255#endif
256#ifdef RLIMIT_MEMLOCK
257 { "memlock", RLIMIT_MEMLOCK },
258#endif
259#ifdef RLIMIT_MSGQUEUE
260 { "msgqueue", RLIMIT_MSGQUEUE },
261#endif
262#ifdef RLIMIT_NICE
263 { "nice", RLIMIT_NICE },
264#endif
265#ifdef RLIMIT_NOFILE
266 { "nofile", RLIMIT_NOFILE },
267#endif
268#ifdef RLIMIT_NPROC
269 { "nproc", RLIMIT_NPROC },
270#endif
271#ifdef RLIMIT_RSS
272 { "rss", RLIMIT_RSS },
273#endif
274#ifdef RLIMIT_RTPRIO
275 { "rtprio", RLIMIT_RTPRIO },
276#endif
277#ifdef RLIMIT_RTTIME
278 { "rttime", RLIMIT_RTTIME },
279#endif
280#ifdef RLIMIT_SIGPENDING
281 { "sigpending", RLIMIT_SIGPENDING },
282#endif
283#ifdef RLIMIT_STACK
284 { "stack", RLIMIT_STACK },
285#endif
286};
287
288static int run_buffer(char *buffer)
289{
290 __do_free char *output = NULL;
291 __do_lxc_pclose struct lxc_popen_FILE *f = NULL;
292 int fd, ret;
293
294 f = lxc_popen(buffer);
295 if (!f)
296 return log_error_errno(-1, errno, "Failed to popen() %s", buffer);
297
298 output = malloc(LXC_LOG_BUFFER_SIZE);
299 if (!output)
300 return log_error_errno(-1, ENOMEM, "Failed to allocate memory for %s", buffer);
301
302 fd = fileno(f->f);
303 if (fd < 0)
304 return log_error_errno(-1, errno, "Failed to retrieve underlying file descriptor");
305
306 for (int i = 0; i < 10; i++) {
307 ssize_t bytes_read;
308
309 bytes_read = lxc_read_nointr(fd, output, LXC_LOG_BUFFER_SIZE - 1);
310 if (bytes_read > 0) {
311 output[bytes_read] = '\0';
312 DEBUG("Script %s produced output: %s", buffer, output);
313 continue;
314 }
315
316 break;
317 }
318
319 ret = lxc_pclose(move_ptr(f));
320 if (ret == -1)
321 return log_error_errno(-1, errno, "Script exited with error");
322 else if (WIFEXITED(ret) && WEXITSTATUS(ret) != 0)
323 return log_error(-1, "Script exited with status %d", WEXITSTATUS(ret));
324 else if (WIFSIGNALED(ret))
325 return log_error(-1, "Script terminated by signal %d", WTERMSIG(ret));
326
327 return 0;
328}
329
330int run_script_argv(const char *name, unsigned int hook_version,
331 const char *section, const char *script,
332 const char *hookname, char **argv)
333{
334 __do_free char *buffer = NULL;
335 int buf_pos, i, ret;
336 size_t size = 0;
337
338 if (hook_version == 0)
339 INFO("Executing script \"%s\" for container \"%s\", config section \"%s\"",
340 script, name, section);
341 else
342 INFO("Executing script \"%s\" for container \"%s\"", script, name);
343
344 for (i = 0; argv && argv[i]; i++)
345 size += strlen(argv[i]) + 1;
346
347 size += STRLITERALLEN("exec");
348 size++;
349 size += strlen(script);
350 size++;
351
352 if (size > INT_MAX)
353 return -EFBIG;
354
355 if (hook_version == 0) {
356 size += strlen(hookname);
357 size++;
358
359 size += strlen(name);
360 size++;
361
362 size += strlen(section);
363 size++;
364
365 if (size > INT_MAX)
366 return -EFBIG;
367 }
368
369 buffer = malloc(size);
370 if (!buffer)
371 return -ENOMEM;
372
373 if (hook_version == 0)
374 buf_pos = snprintf(buffer, size, "exec %s %s %s %s", script, name, section, hookname);
375 else
376 buf_pos = snprintf(buffer, size, "exec %s", script);
377 if (buf_pos < 0 || (size_t)buf_pos >= size)
378 return log_error_errno(-1, errno, "Failed to create command line for script \"%s\"", script);
379
380 if (hook_version == 1) {
381 ret = setenv("LXC_HOOK_TYPE", hookname, 1);
382 if (ret < 0) {
383 return log_error_errno(-1, errno, "Failed to set environment variable: LXC_HOOK_TYPE=%s", hookname);
384 }
385 TRACE("Set environment variable: LXC_HOOK_TYPE=%s", hookname);
386
387 ret = setenv("LXC_HOOK_SECTION", section, 1);
388 if (ret < 0)
389 return log_error_errno(-1, errno, "Failed to set environment variable: LXC_HOOK_SECTION=%s", section);
390 TRACE("Set environment variable: LXC_HOOK_SECTION=%s", section);
391
392 if (strcmp(section, "net") == 0) {
393 char *parent;
394
395 if (!argv || !argv[0])
396 return -1;
397
398 ret = setenv("LXC_NET_TYPE", argv[0], 1);
399 if (ret < 0)
400 return log_error_errno(-1, errno, "Failed to set environment variable: LXC_NET_TYPE=%s", argv[0]);
401 TRACE("Set environment variable: LXC_NET_TYPE=%s", argv[0]);
402
403 parent = argv[1] ? argv[1] : "";
404
405 if (strcmp(argv[0], "macvlan") == 0) {
406 ret = setenv("LXC_NET_PARENT", parent, 1);
407 if (ret < 0)
408 return log_error_errno(-1, errno, "Failed to set environment variable: LXC_NET_PARENT=%s", parent);
409 TRACE("Set environment variable: LXC_NET_PARENT=%s", parent);
410 } else if (strcmp(argv[0], "phys") == 0) {
411 ret = setenv("LXC_NET_PARENT", parent, 1);
412 if (ret < 0)
413 return log_error_errno(-1, errno, "Failed to set environment variable: LXC_NET_PARENT=%s", parent);
414 TRACE("Set environment variable: LXC_NET_PARENT=%s", parent);
415 } else if (strcmp(argv[0], "veth") == 0) {
416 char *peer = argv[2] ? argv[2] : "";
417
418 ret = setenv("LXC_NET_PEER", peer, 1);
419 if (ret < 0)
420 return log_error_errno(-1, errno, "Failed to set environment variable: LXC_NET_PEER=%s", peer);
421 TRACE("Set environment variable: LXC_NET_PEER=%s", peer);
422
423 ret = setenv("LXC_NET_PARENT", parent, 1);
424 if (ret < 0)
425 return log_error_errno(-1, errno, "Failed to set environment variable: LXC_NET_PARENT=%s", parent);
426 TRACE("Set environment variable: LXC_NET_PARENT=%s", parent);
427 }
428 }
429 }
430
431 for (i = 0; argv && argv[i]; i++) {
432 size_t len = size - buf_pos;
433
434 ret = snprintf(buffer + buf_pos, len, " %s", argv[i]);
435 if (ret < 0 || (size_t)ret >= len)
436 return log_error_errno(-1, errno, "Failed to create command line for script \"%s\"", script);
437 buf_pos += ret;
438 }
439
440 return run_buffer(buffer);
441}
442
443int run_script(const char *name, const char *section, const char *script, ...)
444{
445 __do_free char *buffer = NULL;
446 int ret;
447 char *p;
448 va_list ap;
449 size_t size = 0;
450
451 INFO("Executing script \"%s\" for container \"%s\", config section \"%s\"",
452 script, name, section);
453
454 va_start(ap, script);
455 while ((p = va_arg(ap, char *)))
456 size += strlen(p) + 1;
457 va_end(ap);
458
459 size += STRLITERALLEN("exec");
460 size += strlen(script);
461 size += strlen(name);
462 size += strlen(section);
463 size += 4;
464
465 if (size > INT_MAX)
466 return -1;
467
468 buffer = must_realloc(NULL, size);
469 ret = snprintf(buffer, size, "exec %s %s %s", script, name, section);
470 if (ret < 0 || ret >= size)
471 return -1;
472
473 va_start(ap, script);
474 while ((p = va_arg(ap, char *))) {
475 int len = size - ret;
476 int rc;
477 rc = snprintf(buffer + ret, len, " %s", p);
478 if (rc < 0 || rc >= len) {
479 va_end(ap);
480 return -1;
481 }
482 ret += rc;
483 }
484 va_end(ap);
485
486 return run_buffer(buffer);
487}
488
489/* pin_rootfs
490 * if rootfs is a directory, then open ${rootfs}/.lxc-keep for writing for
491 * the duration of the container run, to prevent the container from marking
492 * the underlying fs readonly on shutdown. unlink the file immediately so
493 * no name pollution is happens.
494 * don't unlink on NFS to avoid random named stale handles.
495 * return -1 on error.
496 * return -2 if nothing needed to be pinned.
497 * return an open fd (>=0) if we pinned it.
498 */
499int pin_rootfs(const char *rootfs)
500{
501 __do_free char *absrootfs = NULL;
502 int fd, ret;
503 char absrootfspin[PATH_MAX];
504 struct stat s;
505 struct statfs sfs;
506
507 if (rootfs == NULL || strlen(rootfs) == 0)
508 return -2;
509
510 absrootfs = realpath(rootfs, NULL);
511 if (!absrootfs)
512 return -2;
513
514 ret = stat(absrootfs, &s);
515 if (ret < 0)
516 return -1;
517
518 if (!S_ISDIR(s.st_mode))
519 return -2;
520
521 ret = snprintf(absrootfspin, sizeof(absrootfspin), "%s/.lxc-keep", absrootfs);
522 if (ret < 0 || (size_t)ret >= sizeof(absrootfspin))
523 return -1;
524
525 fd = open(absrootfspin, O_CREAT | O_RDWR, S_IWUSR | S_IRUSR | O_CLOEXEC);
526 if (fd < 0)
527 return fd;
528
529 ret = fstatfs (fd, &sfs);
530 if (ret < 0)
531 return fd;
532
533 if (sfs.f_type == NFS_SUPER_MAGIC)
534 return log_debug(fd, "Rootfs on NFS, not unlinking pin file \"%s\"", absrootfspin);
535
536 (void)unlink(absrootfspin);
537
538 return fd;
539}
540
541/* If we are asking to remount something, make sure that any NOEXEC etc are
542 * honored.
543 */
544unsigned long add_required_remount_flags(const char *s, const char *d,
545 unsigned long flags)
546{
547#ifdef HAVE_STATVFS
548 int ret;
549 struct statvfs sb;
550 unsigned long required_flags = 0;
551
552 if (!s)
553 s = d;
554
555 if (!s)
556 return flags;
557
558 ret = statvfs(s, &sb);
559 if (ret < 0)
560 return flags;
561
562 if (flags & MS_REMOUNT) {
563 if (sb.f_flag & MS_NOSUID)
564 required_flags |= MS_NOSUID;
565 if (sb.f_flag & MS_NODEV)
566 required_flags |= MS_NODEV;
567 if (sb.f_flag & MS_RDONLY)
568 required_flags |= MS_RDONLY;
569 if (sb.f_flag & MS_NOEXEC)
570 required_flags |= MS_NOEXEC;
571 }
572
573 if (sb.f_flag & MS_NOATIME)
574 required_flags |= MS_NOATIME;
575 if (sb.f_flag & MS_NODIRATIME)
576 required_flags |= MS_NODIRATIME;
577 if (sb.f_flag & MS_LAZYTIME)
578 required_flags |= MS_LAZYTIME;
579 if (sb.f_flag & MS_RELATIME)
580 required_flags |= MS_RELATIME;
581 if (sb.f_flag & MS_STRICTATIME)
582 required_flags |= MS_STRICTATIME;
583
584 return flags | required_flags;
585#else
586 return flags;
587#endif
588}
589
590static int add_shmount_to_list(struct lxc_conf *conf)
591{
592 char new_mount[PATH_MAX];
593 /* Offset for the leading '/' since the path_cont
594 * is absolute inside the container.
595 */
596 int offset = 1, ret = -1;
597
598 ret = snprintf(new_mount, sizeof(new_mount),
599 "%s %s none bind,create=dir 0 0", conf->shmount.path_host,
600 conf->shmount.path_cont + offset);
601 if (ret < 0 || (size_t)ret >= sizeof(new_mount))
602 return -1;
603
604 return add_elem_to_mount_list(new_mount, conf);
605}
606
607static int lxc_mount_auto_mounts(struct lxc_conf *conf, int flags, struct lxc_handler *handler)
608{
609 int i, r;
610 static struct {
611 int match_mask;
612 int match_flag;
613 const char *source;
614 const char *destination;
615 const char *fstype;
616 unsigned long flags;
617 const char *options;
618 } default_mounts[] = {
619 /* Read-only bind-mounting... In older kernels, doing that
620 * required to do one MS_BIND mount and then
621 * MS_REMOUNT|MS_RDONLY the same one. According to mount(2)
622 * manpage, MS_BIND honors MS_RDONLY from kernel 2.6.26
623 * onwards. However, this apparently does not work on kernel
624 * 3.8. Unfortunately, on that very same kernel, doing the same
625 * trick as above doesn't seem to work either, there one needs
626 * to ALSO specify MS_BIND for the remount, otherwise the
627 * entire fs is remounted read-only or the mount fails because
628 * it's busy... MS_REMOUNT|MS_BIND|MS_RDONLY seems to work for
629 * kernels as low as 2.6.32...
630 */
631 { LXC_AUTO_PROC_MASK, LXC_AUTO_PROC_MIXED, "proc", "%r/proc", "proc", MS_NODEV|MS_NOEXEC|MS_NOSUID, NULL },
632 /* proc/tty is used as a temporary placeholder for proc/sys/net which we'll move back in a few steps */
633 { LXC_AUTO_PROC_MASK, LXC_AUTO_PROC_MIXED, "%r/proc/sys/net", "%r/proc/tty", NULL, MS_BIND, NULL },
634 { LXC_AUTO_PROC_MASK, LXC_AUTO_PROC_MIXED, "%r/proc/sys", "%r/proc/sys", NULL, MS_BIND, NULL },
635 { LXC_AUTO_PROC_MASK, LXC_AUTO_PROC_MIXED, NULL, "%r/proc/sys", NULL, MS_REMOUNT|MS_BIND|MS_RDONLY, NULL },
636 { LXC_AUTO_PROC_MASK, LXC_AUTO_PROC_MIXED, "%r/proc/tty", "%r/proc/sys/net", NULL, MS_MOVE, NULL },
637 { LXC_AUTO_PROC_MASK, LXC_AUTO_PROC_MIXED, "%r/proc/sysrq-trigger", "%r/proc/sysrq-trigger", NULL, MS_BIND, NULL },
638 { LXC_AUTO_PROC_MASK, LXC_AUTO_PROC_MIXED, NULL, "%r/proc/sysrq-trigger", NULL, MS_REMOUNT|MS_BIND|MS_RDONLY, NULL },
639 { LXC_AUTO_PROC_MASK, LXC_AUTO_PROC_RW, "proc", "%r/proc", "proc", MS_NODEV|MS_NOEXEC|MS_NOSUID, NULL },
640 { LXC_AUTO_SYS_MASK, LXC_AUTO_SYS_RW, "sysfs", "%r/sys", "sysfs", 0, NULL },
641 { LXC_AUTO_SYS_MASK, LXC_AUTO_SYS_RO, "sysfs", "%r/sys", "sysfs", MS_RDONLY, NULL },
642 { LXC_AUTO_SYS_MASK, LXC_AUTO_SYS_MIXED, "sysfs", "%r/sys", "sysfs", MS_NODEV|MS_NOEXEC|MS_NOSUID, NULL },
643 { LXC_AUTO_SYS_MASK, LXC_AUTO_SYS_MIXED, "%r/sys", "%r/sys", NULL, MS_BIND, NULL },
644 { LXC_AUTO_SYS_MASK, LXC_AUTO_SYS_MIXED, NULL, "%r/sys", NULL, MS_REMOUNT|MS_BIND|MS_RDONLY, NULL },
645 { LXC_AUTO_SYS_MASK, LXC_AUTO_SYS_MIXED, "sysfs", "%r/sys/devices/virtual/net", "sysfs", 0, NULL },
646 { LXC_AUTO_SYS_MASK, LXC_AUTO_SYS_MIXED, "%r/sys/devices/virtual/net/devices/virtual/net", "%r/sys/devices/virtual/net", NULL, MS_BIND, NULL },
647 { LXC_AUTO_SYS_MASK, LXC_AUTO_SYS_MIXED, NULL, "%r/sys/devices/virtual/net", NULL, MS_REMOUNT|MS_BIND|MS_NOSUID|MS_NODEV|MS_NOEXEC, NULL },
648 { 0, 0, NULL, NULL, NULL, 0, NULL }
649 };
650
651 for (i = 0; default_mounts[i].match_mask; i++) {
652 __do_free char *destination = NULL, *source = NULL;
653 int saved_errno;
654 unsigned long mflags;
655 if ((flags & default_mounts[i].match_mask) != default_mounts[i].match_flag)
656 continue;
657
658 if (default_mounts[i].source) {
659 /* will act like strdup if %r is not present */
660 source = lxc_string_replace("%r", conf->rootfs.path ? conf->rootfs.mount : "", default_mounts[i].source);
661 if (!source)
662 return -1;
663 }
664
665 if (!default_mounts[i].destination)
666 return log_error(-1, "BUG: auto mounts destination %d was NULL", i);
667
668 /* will act like strdup if %r is not present */
669 destination = lxc_string_replace("%r", conf->rootfs.path ? conf->rootfs.mount : "", default_mounts[i].destination);
670 if (!destination)
671 return -1;
672
673 mflags = add_required_remount_flags(source, destination,
674 default_mounts[i].flags);
675 r = safe_mount(source, destination, default_mounts[i].fstype,
676 mflags, default_mounts[i].options,
677 conf->rootfs.path ? conf->rootfs.mount : NULL);
678 saved_errno = errno;
679 if (r < 0 && errno == ENOENT) {
680 INFO("Mount source or target for \"%s\" on \"%s\" does not exist. Skipping", source, destination);
681 r = 0;
682 } else if (r < 0) {
683 SYSERROR("Failed to mount \"%s\" on \"%s\" with flags %lu", source, destination, mflags);
684 }
685
686 if (r < 0) {
687 errno = saved_errno;
688 return -1;
689 }
690 }
691
692 if (flags & LXC_AUTO_CGROUP_MASK) {
693 int cg_flags;
694
695 cg_flags = flags & (LXC_AUTO_CGROUP_MASK & ~LXC_AUTO_CGROUP_FORCE);
696 /* If the type of cgroup mount was not specified, it depends on
697 * the container's capabilities as to what makes sense: if we
698 * have CAP_SYS_ADMIN, the read-only part can be remounted
699 * read-write anyway, so we may as well default to read-write;
700 * then the admin will not be given a false sense of security.
701 * (And if they really want mixed r/o r/w, then they can
702 * explicitly specify :mixed.) OTOH, if the container lacks
703 * CAP_SYS_ADMIN, do only default to :mixed, because then the
704 * container can't remount it read-write.
705 */
706 if (cg_flags == LXC_AUTO_CGROUP_NOSPEC || cg_flags == LXC_AUTO_CGROUP_FULL_NOSPEC) {
707 int has_sys_admin = 0;
708
709 if (!lxc_list_empty(&conf->keepcaps))
710 has_sys_admin = in_caplist(CAP_SYS_ADMIN, &conf->keepcaps);
711 else
712 has_sys_admin = !in_caplist(CAP_SYS_ADMIN, &conf->caps);
713
714 if (cg_flags == LXC_AUTO_CGROUP_NOSPEC)
715 cg_flags = has_sys_admin ? LXC_AUTO_CGROUP_RW : LXC_AUTO_CGROUP_MIXED;
716 else
717 cg_flags = has_sys_admin ? LXC_AUTO_CGROUP_FULL_RW : LXC_AUTO_CGROUP_FULL_MIXED;
718 }
719
720 if (flags & LXC_AUTO_CGROUP_FORCE)
721 cg_flags |= LXC_AUTO_CGROUP_FORCE;
722
723 if (!handler->cgroup_ops->mount(handler->cgroup_ops,
724 handler,
725 conf->rootfs.path ? conf->rootfs.mount : "",
726 cg_flags))
727 return log_error_errno(-1, errno, "Failed to mount \"/sys/fs/cgroup\"");
728 }
729
730 if (flags & LXC_AUTO_SHMOUNTS_MASK) {
731 int ret = add_shmount_to_list(conf);
732 if (ret < 0)
733 return log_error(-1, "Failed to add shmount entry to container config");
734 }
735
736 return 0;
737}
738
739static int setup_utsname(struct utsname *utsname)
740{
741 int ret;
742
743 if (!utsname)
744 return 0;
745
746 ret = sethostname(utsname->nodename, strlen(utsname->nodename));
747 if (ret < 0)
748 return log_error_errno(-1, errno, "Failed to set the hostname to \"%s\"",
749 utsname->nodename);
750
751 INFO("Set hostname to \"%s\"", utsname->nodename);
752
753 return 0;
754}
755
756struct dev_symlinks {
757 const char *oldpath;
758 const char *name;
759};
760
761static const struct dev_symlinks dev_symlinks[] = {
762 { "/proc/self/fd", "fd" },
763 { "/proc/self/fd/0", "stdin" },
764 { "/proc/self/fd/1", "stdout" },
765 { "/proc/self/fd/2", "stderr" },
766};
767
768static int lxc_setup_dev_symlinks(const struct lxc_rootfs *rootfs)
769{
770 int i, ret;
771 char path[PATH_MAX];
772 struct stat s;
773
774 for (i = 0; i < sizeof(dev_symlinks) / sizeof(dev_symlinks[0]); i++) {
775 const struct dev_symlinks *d = &dev_symlinks[i];
776
777 ret = snprintf(path, sizeof(path), "%s/dev/%s",
778 rootfs->path ? rootfs->mount : "", d->name);
779 if (ret < 0 || (size_t)ret >= sizeof(path))
780 return -1;
781
782 /* Stat the path first. If we don't get an error accept it as
783 * is and don't try to create it
784 */
785 ret = stat(path, &s);
786 if (ret == 0)
787 continue;
788
789 ret = symlink(d->oldpath, path);
790 if (ret && errno != EEXIST) {
791 if (errno == EROFS)
792 WARN("Failed to create \"%s\". Read-only filesystem", path);
793 else
794 return log_error_errno(-1, errno, "Failed to create \"%s\"", path);
795 }
796 }
797
798 return 0;
799}
800
801/* Build a space-separate list of ptys to pass to systemd. */
802static bool append_ttyname(char **pp, char *name)
803{
804 char *p;
805 size_t size;
806
807 if (!*pp) {
808 *pp = malloc(strlen(name) + strlen("container_ttys=") + 1);
809 if (!*pp)
810 return false;
811
812 sprintf(*pp, "container_ttys=%s", name);
813 return true;
814 }
815
816 size = strlen(*pp) + strlen(name) + 2;
817 p = realloc(*pp, size);
818 if (!p)
819 return false;
820
821 *pp = p;
822 (void)strlcat(p, " ", size);
823 (void)strlcat(p, name, size);
824
825 return true;
826}
827
828static int lxc_setup_ttys(struct lxc_conf *conf)
829{
830 int i, ret;
831 const struct lxc_tty_info *ttys = &conf->ttys;
832 char *ttydir = ttys->dir;
833 char path[PATH_MAX], lxcpath[PATH_MAX];
834
835 if (!conf->rootfs.path)
836 return 0;
837
838 for (i = 0; i < ttys->max; i++) {
839 struct lxc_terminal_info *tty = &ttys->tty[i];
840
841 ret = snprintf(path, sizeof(path), "/dev/tty%d", i + 1);
842 if (ret < 0 || (size_t)ret >= sizeof(path))
843 return -1;
844
845 if (ttydir) {
846 /* create dev/lxc/tty%d" */
847 ret = snprintf(lxcpath, sizeof(lxcpath),
848 "/dev/%s/tty%d", ttydir, i + 1);
849 if (ret < 0 || (size_t)ret >= sizeof(lxcpath))
850 return -1;
851
852 ret = mknod(lxcpath, S_IFREG | 0000, 0);
853 if (ret < 0 && errno != EEXIST) {
854 SYSERROR("Failed to create \"%s\"", lxcpath);
855 return -1;
856 }
857
858 ret = unlink(path);
859 if (ret < 0 && errno != ENOENT) {
860 SYSERROR("Failed to unlink \"%s\"", path);
861 return -1;
862 }
863
864 ret = mount(tty->name, lxcpath, "none", MS_BIND, 0);
865 if (ret < 0) {
866 SYSWARN("Failed to bind mount \"%s\" onto \"%s\"", tty->name, lxcpath);
867 continue;
868 }
869 DEBUG("Bind mounted \"%s\" onto \"%s\"", tty->name, lxcpath);
870
871 ret = snprintf(lxcpath, sizeof(lxcpath), "%s/tty%d",
872 ttydir, i + 1);
873 if (ret < 0 || (size_t)ret >= sizeof(lxcpath))
874 return -1;
875
876 ret = symlink(lxcpath, path);
877 if (ret < 0)
878 return log_error_errno(-1, errno, "Failed to create symlink \"%s\" -> \"%s\"", path, lxcpath);
879 } else {
880 /* If we populated /dev, then we need to create
881 * /dev/ttyN
882 */
883 ret = mknod(path, S_IFREG | 0000, 0);
884 if (ret < 0) /* this isn't fatal, continue */
885 SYSERROR("Failed to create \"%s\"", path);
886
887 ret = mount(tty->name, path, "none", MS_BIND, 0);
888 if (ret < 0) {
889 SYSERROR("Failed to mount '%s'->'%s'", tty->name, path);
890 continue;
891 }
892
893 DEBUG("Bind mounted \"%s\" onto \"%s\"", tty->name, path);
894 }
895
896 if (!append_ttyname(&conf->ttys.tty_names, tty->name))
897 return log_error(-1, "Error setting up container_ttys string");
898 }
899
900 INFO("Finished setting up %zu /dev/tty<N> device(s)", ttys->max);
901 return 0;
902}
903
904define_cleanup_function(struct lxc_tty_info *, lxc_delete_tty);
905
906int lxc_allocate_ttys(struct lxc_conf *conf)
907{
908 struct lxc_terminal_info *tty_new = NULL;
909 int ret;
910 call_cleaner(lxc_delete_tty) struct lxc_tty_info *ttys = &conf->ttys;
911
912 /* no tty in the configuration */
913 if (ttys->max == 0)
914 return 0;
915
916 tty_new = malloc(sizeof(struct lxc_terminal_info) * ttys->max);
917 if (!tty_new)
918 return -ENOMEM;
919 ttys->tty = tty_new;
920
921 for (size_t i = 0; i < ttys->max; i++) {
922 struct lxc_terminal_info *tty = &ttys->tty[i];
923
924 tty->ptmx = -EBADF;
925 tty->pts = -EBADF;
926 ret = openpty(&tty->ptmx, &tty->pts, NULL, NULL, NULL);
927 if (ret < 0) {
928 ttys->max = i;
929 return log_error_errno(-ENOTTY, ENOTTY, "Failed to create tty %zu", i);
930 }
931
932 ret = ttyname_r(tty->pts, tty->name, sizeof(tty->name));
933 if (ret < 0) {
934 ttys->max = i;
935 return log_error_errno(-ENOTTY, ENOTTY, "Failed to retrieve name of tty %zu pts", i);
936 }
937
938 DEBUG("Created tty \"%s\" with ptmx fd %d and pts fd %d",
939 tty->name, tty->ptmx, tty->pts);
940
941 /* Prevent leaking the file descriptors to the container */
942 ret = fd_cloexec(tty->ptmx, true);
943 if (ret < 0)
944 SYSWARN("Failed to set FD_CLOEXEC flag on ptmx fd %d of tty device \"%s\"",
945 tty->ptmx, tty->name);
946
947 ret = fd_cloexec(tty->pts, true);
948 if (ret < 0)
949 SYSWARN("Failed to set FD_CLOEXEC flag on pts fd %d of tty device \"%s\"",
950 tty->pts, tty->name);
951
952 tty->busy = -1;
953 }
954
955 INFO("Finished creating %zu tty devices", ttys->max);
956 move_ptr(ttys);
957 return 0;
958}
959
960void lxc_delete_tty(struct lxc_tty_info *ttys)
961{
962 if (!ttys->tty)
963 return;
964
965 for (int i = 0; i < ttys->max; i++) {
966 struct lxc_terminal_info *tty = &ttys->tty[i];
967 close_prot_errno_disarm(tty->ptmx);
968 close_prot_errno_disarm(tty->pts);
969 }
970
971 free_disarm(ttys->tty);
972}
973
974static int lxc_send_ttys_to_parent(struct lxc_handler *handler)
975{
976 int i;
977 int ret = -1;
978 struct lxc_conf *conf = handler->conf;
979 struct lxc_tty_info *ttys = &conf->ttys;
980 int sock = handler->data_sock[0];
981
982 if (ttys->max == 0)
983 return 0;
984
985 for (i = 0; i < ttys->max; i++) {
986 int ttyfds[2];
987 struct lxc_terminal_info *tty = &ttys->tty[i];
988
989 ttyfds[0] = tty->ptmx;
990 ttyfds[1] = tty->pts;
991
992 ret = lxc_abstract_unix_send_fds(sock, ttyfds, 2, NULL, 0);
993 if (ret < 0)
994 break;
995
996 TRACE("Sent tty \"%s\" with ptmx fd %d and pts fd %d to parent",
997 tty->name, tty->ptmx, tty->pts);
998 }
999
1000 if (ret < 0)
1001 SYSERROR("Failed to send %zu ttys to parent", ttys->max);
1002 else
1003 TRACE("Sent %zu ttys to parent", ttys->max);
1004
1005 return ret;
1006}
1007
1008static int lxc_create_ttys(struct lxc_handler *handler)
1009{
1010 int ret = -1;
1011 struct lxc_conf *conf = handler->conf;
1012
1013 ret = lxc_allocate_ttys(conf);
1014 if (ret < 0) {
1015 ERROR("Failed to allocate ttys");
1016 goto on_error;
1017 }
1018
1019 ret = lxc_send_ttys_to_parent(handler);
1020 if (ret < 0) {
1021 ERROR("Failed to send ttys to parent");
1022 goto on_error;
1023 }
1024
1025 if (!conf->is_execute) {
1026 ret = lxc_setup_ttys(conf);
1027 if (ret < 0) {
1028 ERROR("Failed to setup ttys");
1029 goto on_error;
1030 }
1031 }
1032
1033 if (conf->ttys.tty_names) {
1034 ret = setenv("container_ttys", conf->ttys.tty_names, 1);
1035 if (ret < 0)
1036 SYSERROR("Failed to set \"container_ttys=%s\"", conf->ttys.tty_names);
1037 }
1038
1039 ret = 0;
1040
1041on_error:
1042 lxc_delete_tty(&conf->ttys);
1043
1044 return ret;
1045}
1046
1047/* Just create a path for /dev under $lxcpath/$name and in rootfs If we hit an
1048 * error, log it but don't fail yet.
1049 */
1050static int mount_autodev(const char *name, const struct lxc_rootfs *rootfs,
1051 int autodevtmpfssize, const char *lxcpath)
1052{
1053 __do_free char *path = NULL;
1054 int ret;
1055 size_t clen;
1056 mode_t cur_mask;
1057 char mount_options[128];
1058
1059 INFO("Preparing \"/dev\"");
1060
1061 /* $(rootfs->mount) + "/dev/pts" + '\0' */
1062 clen = (rootfs->path ? strlen(rootfs->mount) : 0) + 9;
1063 path = must_realloc(NULL, clen);
1064 sprintf(mount_options, "size=%d,mode=755", (autodevtmpfssize != 0) ? autodevtmpfssize : 500000);
1065 DEBUG("Using mount options: %s", mount_options);
1066
1067 ret = snprintf(path, clen, "%s/dev", rootfs->path ? rootfs->mount : "");
1068 if (ret < 0 || (size_t)ret >= clen)
1069 return -1;
1070
1071 cur_mask = umask(S_IXUSR | S_IXGRP | S_IXOTH);
1072 ret = mkdir(path, S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH);
1073 if (ret < 0 && errno != EEXIST) {
1074 SYSERROR("Failed to create \"/dev\" directory");
1075 ret = -errno;
1076 goto reset_umask;
1077 }
1078
1079 ret = safe_mount("none", path, "tmpfs", 0, mount_options,
1080 rootfs->path ? rootfs->mount : NULL );
1081 if (ret < 0) {
1082 SYSERROR("Failed to mount tmpfs on \"%s\"", path);
1083 goto reset_umask;
1084 }
1085 TRACE("Mounted tmpfs on \"%s\"", path);
1086
1087 ret = snprintf(path, clen, "%s/dev/pts", rootfs->path ? rootfs->mount : "");
1088 if (ret < 0 || (size_t)ret >= clen) {
1089 ret = -1;
1090 goto reset_umask;
1091 }
1092
1093 /* If we are running on a devtmpfs mapping, dev/pts may already exist.
1094 * If not, then create it and exit if that fails...
1095 */
1096 ret = mkdir(path, S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH);
1097 if (ret < 0 && errno != EEXIST) {
1098 SYSERROR("Failed to create directory \"%s\"", path);
1099 ret = -errno;
1100 goto reset_umask;
1101 }
1102
1103 ret = 0;
1104
1105reset_umask:
1106 (void)umask(cur_mask);
1107
1108 INFO("Prepared \"/dev\"");
1109 return ret;
1110}
1111
1112struct lxc_device_node {
1113 const char *name;
1114 const mode_t mode;
1115 const int maj;
1116 const int min;
1117};
1118
1119static const struct lxc_device_node lxc_devices[] = {
1120 { "full", S_IFCHR | S_IRWXU | S_IRWXG | S_IRWXO, 1, 7 },
1121 { "null", S_IFCHR | S_IRWXU | S_IRWXG | S_IRWXO, 1, 3 },
1122 { "random", S_IFCHR | S_IRWXU | S_IRWXG | S_IRWXO, 1, 8 },
1123 { "tty", S_IFCHR | S_IRWXU | S_IRWXG | S_IRWXO, 5, 0 },
1124 { "urandom", S_IFCHR | S_IRWXU | S_IRWXG | S_IRWXO, 1, 9 },
1125 { "zero", S_IFCHR | S_IRWXU | S_IRWXG | S_IRWXO, 1, 5 },
1126};
1127
1128
1129enum {
1130 LXC_DEVNODE_BIND,
1131 LXC_DEVNODE_MKNOD,
1132 LXC_DEVNODE_PARTIAL,
1133 LXC_DEVNODE_OPEN,
1134};
1135
1136static int lxc_fill_autodev(const struct lxc_rootfs *rootfs)
1137{
1138 int i, ret;
1139 char path[PATH_MAX];
1140 mode_t cmask;
1141 int use_mknod = LXC_DEVNODE_MKNOD;
1142
1143 ret = snprintf(path, PATH_MAX, "%s/dev",
1144 rootfs->path ? rootfs->mount : "");
1145 if (ret < 0 || ret >= PATH_MAX)
1146 return -1;
1147
1148 /* ignore, just don't try to fill in */
1149 if (!dir_exists(path))
1150 return 0;
1151
1152 INFO("Populating \"/dev\"");
1153
1154 cmask = umask(S_IXUSR | S_IXGRP | S_IXOTH);
1155 for (i = 0; i < sizeof(lxc_devices) / sizeof(lxc_devices[0]); i++) {
1156 char hostpath[PATH_MAX];
1157 const struct lxc_device_node *device = &lxc_devices[i];
1158
1159 ret = snprintf(path, PATH_MAX, "%s/dev/%s",
1160 rootfs->path ? rootfs->mount : "", device->name);
1161 if (ret < 0 || ret >= PATH_MAX)
1162 return -1;
1163
1164 if (use_mknod >= LXC_DEVNODE_MKNOD) {
1165 ret = mknod(path, device->mode, makedev(device->maj, device->min));
1166 if (ret == 0 || (ret < 0 && errno == EEXIST)) {
1167 DEBUG("Created device node \"%s\"", path);
1168 } else if (ret < 0) {
1169 if (errno != EPERM)
1170 return log_error_errno(-1, errno, "Failed to create device node \"%s\"", path);
1171
1172 use_mknod = LXC_DEVNODE_BIND;
1173 }
1174
1175 /* Device nodes are fully useable. */
1176 if (use_mknod == LXC_DEVNODE_OPEN)
1177 continue;
1178
1179 if (use_mknod == LXC_DEVNODE_MKNOD) {
1180 /* See
1181 * - https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=55956b59df336f6738da916dbb520b6e37df9fbd
1182 * - https://lists.linuxfoundation.org/pipermail/containers/2018-June/039176.html
1183 */
1184 ret = open(path, O_RDONLY | O_CLOEXEC);
1185 if (ret >= 0) {
1186 close_prot_errno_disarm(ret);
1187 /* Device nodes are fully useable. */
1188 use_mknod = LXC_DEVNODE_OPEN;
1189 continue;
1190 }
1191
1192 SYSTRACE("Failed to open \"%s\" device", path);
1193 /* Device nodes are only partially useable. */
1194 use_mknod = LXC_DEVNODE_PARTIAL;
1195 }
1196 }
1197
1198 if (use_mknod != LXC_DEVNODE_PARTIAL) {
1199 /* If we are dealing with partially functional device
1200 * nodes the prio mknod() call will have created the
1201 * device node so we can use it as a bind-mount target.
1202 */
1203 ret = mknod(path, S_IFREG | 0000, 0);
1204 if (ret < 0 && errno != EEXIST)
1205 return log_error_errno(-1, errno, "Failed to create file \"%s\"", path);
1206 }
1207
1208 /* Fallback to bind-mounting the device from the host. */
1209 ret = snprintf(hostpath, PATH_MAX, "/dev/%s", device->name);
1210 if (ret < 0 || ret >= PATH_MAX)
1211 return -1;
1212
1213 ret = safe_mount(hostpath, path, 0, MS_BIND, NULL,
1214 rootfs->path ? rootfs->mount : NULL);
1215 if (ret < 0)
1216 return log_error_errno(-1, errno, "Failed to bind mount host device node \"%s\" onto \"%s\"",
1217 hostpath, path);
1218 DEBUG("Bind mounted host device node \"%s\" onto \"%s\"", hostpath, path);
1219 }
1220 (void)umask(cmask);
1221
1222 INFO("Populated \"/dev\"");
1223 return 0;
1224}
1225
1226static int lxc_mount_rootfs(struct lxc_conf *conf)
1227{
1228 int ret;
1229 struct lxc_storage *bdev;
1230 const struct lxc_rootfs *rootfs = &conf->rootfs;
1231
1232 if (!rootfs->path) {
1233 ret = mount("", "/", NULL, MS_SLAVE | MS_REC, 0);
1234 if (ret < 0)
1235 return log_error_errno(-1, errno, "Failed to recursively turn root mount tree into dependent mount");
1236
1237 return 0;
1238 }
1239
1240 ret = access(rootfs->mount, F_OK);
1241 if (ret != 0)
1242 return log_error_errno(-1, errno, "Failed to access to \"%s\". Check it is present",
1243 rootfs->mount);
1244
1245 bdev = storage_init(conf);
1246 if (!bdev)
1247 return log_error(-1, "Failed to mount rootfs \"%s\" onto \"%s\" with options \"%s\"",
1248 rootfs->path, rootfs->mount,
1249 rootfs->options ? rootfs->options : "(null)");
1250
1251 ret = bdev->ops->mount(bdev);
1252 storage_put(bdev);
1253 if (ret < 0)
1254 return log_error(-1, "Failed to mount rootfs \"%s\" onto \"%s\" with options \"%s\"",
1255 rootfs->path, rootfs->mount,
1256 rootfs->options ? rootfs->options : "(null)");
1257
1258 DEBUG("Mounted rootfs \"%s\" onto \"%s\" with options \"%s\"",
1259 rootfs->path, rootfs->mount,
1260 rootfs->options ? rootfs->options : "(null)");
1261
1262 return 0;
1263}
1264
1265int lxc_chroot(const struct lxc_rootfs *rootfs)
1266{
1267 __do_free char *nroot = NULL;
1268 int i, ret;
1269 char *root = rootfs->mount;
1270
1271 nroot = realpath(root, NULL);
1272 if (!nroot)
1273 return log_error_errno(-1, errno, "Failed to resolve \"%s\"", root);
1274
1275 ret = chdir("/");
1276 if (ret < 0)
1277 return -1;
1278
1279 /* We could use here MS_MOVE, but in userns this mount is locked and
1280 * can't be moved.
1281 */
1282 ret = mount(nroot, "/", NULL, MS_REC | MS_BIND, NULL);
1283 if (ret < 0)
1284 return log_error_errno(-1, errno, "Failed to mount \"%s\" onto \"/\" as MS_REC | MS_BIND", nroot);
1285
1286 ret = mount(NULL, "/", NULL, MS_REC | MS_PRIVATE, NULL);
1287 if (ret < 0)
1288 return log_error_errno(-1, errno, "Failed to remount \"/\"");
1289
1290 /* The following code cleans up inherited mounts which are not required
1291 * for CT.
1292 *
1293 * The mountinfo file shows not all mounts, if a few points have been
1294 * unmounted between read operations from the mountinfo. So we need to
1295 * read mountinfo a few times.
1296 *
1297 * This loop can be skipped if a container uses userns, because all
1298 * inherited mounts are locked and we should live with all this trash.
1299 */
1300 for (;;) {
1301 __do_fclose FILE *f = NULL;
1302 __do_free char *line = NULL;
1303 char *slider1, *slider2;
1304 int progress = 0;
1305 size_t len = 0;
1306
1307 f = fopen("./proc/self/mountinfo", "re");
1308 if (!f)
1309 return log_error_errno(-1, errno, "Failed to open \"/proc/self/mountinfo\"");
1310
1311 while (getline(&line, &len, f) > 0) {
1312 for (slider1 = line, i = 0; slider1 && i < 4; i++)
1313 slider1 = strchr(slider1 + 1, ' ');
1314
1315 if (!slider1)
1316 continue;
1317
1318 slider2 = strchr(slider1 + 1, ' ');
1319 if (!slider2)
1320 continue;
1321
1322 *slider2 = '\0';
1323 *slider1 = '.';
1324
1325 if (strcmp(slider1 + 1, "/") == 0)
1326 continue;
1327
1328 if (strcmp(slider1 + 1, "/proc") == 0)
1329 continue;
1330
1331 ret = umount2(slider1, MNT_DETACH);
1332 if (ret == 0)
1333 progress++;
1334 }
1335
1336 if (!progress)
1337 break;
1338 }
1339
1340 /* This also can be skipped if a container uses userns. */
1341 (void)umount2("./proc", MNT_DETACH);
1342
1343 /* It is weird, but chdir("..") moves us in a new root */
1344 ret = chdir("..");
1345 if (ret < 0)
1346 return log_error_errno(-1, errno, "Failed to chdir(\"..\")");
1347
1348 ret = chroot(".");
1349 if (ret < 0)
1350 return log_error_errno(-1, errno, "Failed to chroot(\".\")");
1351
1352 return 0;
1353}
1354
1355/* (The following explanation is copied verbatim from the kernel.)
1356 *
1357 * pivot_root Semantics:
1358 * Moves the root file system of the current process to the directory put_old,
1359 * makes new_root as the new root file system of the current process, and sets
1360 * root/cwd of all processes which had them on the current root to new_root.
1361 *
1362 * Restrictions:
1363 * The new_root and put_old must be directories, and must not be on the
1364 * same file system as the current process root. The put_old must be
1365 * underneath new_root, i.e. adding a non-zero number of /.. to the string
1366 * pointed to by put_old must yield the same directory as new_root. No other
1367 * file system may be mounted on put_old. After all, new_root is a mountpoint.
1368 *
1369 * Also, the current root cannot be on the 'rootfs' (initial ramfs) filesystem.
1370 * See Documentation/filesystems/ramfs-rootfs-initramfs.txt for alternatives
1371 * in this situation.
1372 *
1373 * Notes:
1374 * - we don't move root/cwd if they are not at the root (reason: if something
1375 * cared enough to change them, it's probably wrong to force them elsewhere)
1376 * - it's okay to pick a root that isn't the root of a file system, e.g.
1377 * /nfs/my_root where /nfs is the mount point. It must be a mountpoint,
1378 * though, so you may need to say mount --bind /nfs/my_root /nfs/my_root
1379 * first.
1380 */
1381static int lxc_pivot_root(const char *rootfs)
1382{
1383 __do_close int oldroot = -EBADF, newroot = -EBADF;
1384 int ret;
1385
1386 oldroot = open("/", O_DIRECTORY | O_RDONLY | O_CLOEXEC);
1387 if (oldroot < 0)
1388 return log_error_errno(-1, errno, "Failed to open old root directory");
1389
1390 newroot = open(rootfs, O_DIRECTORY | O_RDONLY | O_CLOEXEC);
1391 if (newroot < 0)
1392 return log_error_errno(-1, errno, "Failed to open new root directory");
1393
1394 /* change into new root fs */
1395 ret = fchdir(newroot);
1396 if (ret < 0)
1397 return log_error_errno(-1, errno, "Failed to change to new rootfs \"%s\"", rootfs);
1398
1399 /* pivot_root into our new root fs */
1400 ret = pivot_root(".", ".");
1401 if (ret < 0)
1402 return log_error_errno(-1, errno, "Failed to pivot_root()");
1403
1404 /* At this point the old-root is mounted on top of our new-root. To
1405 * unmounted it we must not be chdir'd into it, so escape back to
1406 * old-root.
1407 */
1408 ret = fchdir(oldroot);
1409 if (ret < 0)
1410 return log_error_errno(-1, errno, "Failed to enter old root directory");
1411
1412 /* Make oldroot a depedent mount to make sure our umounts don't propagate to the
1413 * host.
1414 */
1415 ret = mount("", ".", "", MS_SLAVE | MS_REC, NULL);
1416 if (ret < 0)
1417 return log_error_errno(-1, errno, "Failed to recursively turn old root mount tree into dependent mount");
1418
1419 ret = umount2(".", MNT_DETACH);
1420 if (ret < 0)
1421 return log_error_errno(-1, errno, "Failed to detach old root directory");
1422
1423 ret = fchdir(newroot);
1424 if (ret < 0)
1425 return log_error_errno(-1, errno, "Failed to re-enter new root directory");
1426
1427 TRACE("pivot_root(\"%s\") successful", rootfs);
1428
1429 return 0;
1430}
1431
1432static int lxc_setup_rootfs_switch_root(const struct lxc_rootfs *rootfs)
1433{
1434 if (!rootfs->path)
1435 return log_debug(0, "Container does not have a rootfs");
1436
1437 if (detect_ramfs_rootfs())
1438 return lxc_chroot(rootfs);
1439
1440 return lxc_pivot_root(rootfs->mount);
1441}
1442
1443static const struct id_map *find_mapped_nsid_entry(const struct lxc_conf *conf,
1444 unsigned id,
1445 enum idtype idtype)
1446{
1447 struct lxc_list *it;
1448 struct id_map *map;
1449 struct id_map *retmap = NULL;
1450
1451 /* Shortcut for container's root mappings. */
1452 if (id == 0) {
1453 if (idtype == ID_TYPE_UID)
1454 return conf->root_nsuid_map;
1455
1456 if (idtype == ID_TYPE_GID)
1457 return conf->root_nsgid_map;
1458 }
1459
1460 lxc_list_for_each(it, &conf->id_map) {
1461 map = it->elem;
1462 if (map->idtype != idtype)
1463 continue;
1464
1465 if (id >= map->nsid && id < map->nsid + map->range) {
1466 retmap = map;
1467 break;
1468 }
1469 }
1470
1471 return retmap;
1472}
1473
1474static int lxc_setup_devpts(struct lxc_conf *conf)
1475{
1476 int ret;
1477 char **opts;
1478 char devpts_mntopts[256];
1479 char *mntopt_sets[5];
1480 char default_devpts_mntopts[256] = "gid=5,newinstance,ptmxmode=0666,mode=0620";
1481
1482 if (conf->pty_max <= 0)
1483 return log_debug(0, "No new devpts instance will be mounted since no pts devices are requested");
1484
1485 ret = snprintf(devpts_mntopts, sizeof(devpts_mntopts), "%s,max=%zu",
1486 default_devpts_mntopts, conf->pty_max);
1487 if (ret < 0 || (size_t)ret >= sizeof(devpts_mntopts))
1488 return -1;
1489
1490 (void)umount2("/dev/pts", MNT_DETACH);
1491
1492 /* Create mountpoint for devpts instance. */
1493 ret = mkdir("/dev/pts", 0755);
1494 if (ret < 0 && errno != EEXIST)
1495 return log_error_errno(-1, errno, "Failed to create \"/dev/pts\" directory");
1496
1497 /* gid=5 && max= */
1498 mntopt_sets[0] = devpts_mntopts;
1499
1500 /* !gid=5 && max= */
1501 mntopt_sets[1] = devpts_mntopts + STRLITERALLEN("gid=5") + 1;
1502
1503 /* gid=5 && !max= */
1504 mntopt_sets[2] = default_devpts_mntopts;
1505
1506 /* !gid=5 && !max= */
1507 mntopt_sets[3] = default_devpts_mntopts + STRLITERALLEN("gid=5") + 1;
1508
1509 /* end */
1510 mntopt_sets[4] = NULL;
1511
1512 for (ret = -1, opts = mntopt_sets; opts && *opts; opts++) {
1513 /* mount new devpts instance */
1514 ret = mount("devpts", "/dev/pts", "devpts", MS_NOSUID | MS_NOEXEC, *opts);
1515 if (ret == 0)
1516 break;
1517 }
1518
1519 if (ret < 0)
1520 return log_error_errno(-1, errno, "Failed to mount new devpts instance");
1521 DEBUG("Mount new devpts instance with options \"%s\"", *opts);
1522
1523 /* Remove any pre-existing /dev/ptmx file. */
1524 ret = remove("/dev/ptmx");
1525 if (ret < 0) {
1526 if (errno != ENOENT)
1527 return log_error_errno(-1, errno, "Failed to remove existing \"/dev/ptmx\" file");
1528 } else {
1529 DEBUG("Removed existing \"/dev/ptmx\" file");
1530 }
1531
1532 /* Create dummy /dev/ptmx file as bind mountpoint for /dev/pts/ptmx. */
1533 ret = mknod("/dev/ptmx", S_IFREG | 0000, 0);
1534 if (ret < 0 && errno != EEXIST)
1535 return log_error_errno(-1, errno, "Failed to create dummy \"/dev/ptmx\" file as bind mount target");
1536 DEBUG("Created dummy \"/dev/ptmx\" file as bind mount target");
1537
1538 /* Fallback option: create symlink /dev/ptmx -> /dev/pts/ptmx */
1539 ret = mount("/dev/pts/ptmx", "/dev/ptmx", NULL, MS_BIND, NULL);
1540 if (!ret)
1541 return log_debug(0, "Bind mounted \"/dev/pts/ptmx\" to \"/dev/ptmx\"");
1542 else
1543 /* Fallthrough and try to create a symlink. */
1544 ERROR("Failed to bind mount \"/dev/pts/ptmx\" to \"/dev/ptmx\"");
1545
1546 /* Remove the dummy /dev/ptmx file we created above. */
1547 ret = remove("/dev/ptmx");
1548 if (ret < 0)
1549 return log_error_errno(-1, errno, "Failed to remove existing \"/dev/ptmx\"");
1550
1551 /* Fallback option: Create symlink /dev/ptmx -> /dev/pts/ptmx. */
1552 ret = symlink("/dev/pts/ptmx", "/dev/ptmx");
1553 if (ret < 0)
1554 return log_error_errno(-1, errno, "Failed to create symlink from \"/dev/ptmx\" to \"/dev/pts/ptmx\"");
1555 DEBUG("Created symlink from \"/dev/ptmx\" to \"/dev/pts/ptmx\"");
1556
1557 return 0;
1558}
1559
1560static int setup_personality(int persona)
1561{
1562 int ret;
1563
1564#if HAVE_SYS_PERSONALITY_H
1565 if (persona == -1)
1566 return 0;
1567
1568 ret = personality(persona);
1569 if (ret < 0)
1570 return log_error_errno(-1, errno, "Failed to set personality to \"0x%x\"", persona);
1571
1572 INFO("Set personality to \"0x%x\"", persona);
1573#endif
1574
1575 return 0;
1576}
1577
1578static inline bool wants_console(const struct lxc_terminal *terminal)
1579{
1580 return !terminal->path || strcmp(terminal->path, "none");
1581}
1582
1583static int lxc_setup_dev_console(const struct lxc_rootfs *rootfs,
1584 const struct lxc_terminal *console,
1585 int pts_mnt_fd)
1586{
1587 int ret;
1588 char path[PATH_MAX];
1589 char *rootfs_path = rootfs->path ? rootfs->mount : "";
1590
1591 if (!wants_console(console))
1592 return 0;
1593
1594 ret = snprintf(path, sizeof(path), "%s/dev/console", rootfs_path);
1595 if (ret < 0 || (size_t)ret >= sizeof(path))
1596 return -1;
1597
1598 /*
1599 * When we are asked to setup a console we remove any previous
1600 * /dev/console bind-mounts.
1601 */
1602 if (file_exists(path)) {
1603 ret = lxc_unstack_mountpoint(path, false);
1604 if (ret < 0)
1605 return log_error_errno(-ret, errno, "Failed to unmount \"%s\"", path);
1606 else
1607 DEBUG("Cleared all (%d) mounts from \"%s\"", ret, path);
1608 }
1609
1610 /*
1611 * For unprivileged containers autodev or automounts will already have
1612 * taken care of creating /dev/console.
1613 */
1614 ret = mknod(path, S_IFREG | 0000, 0);
1615 if (ret < 0 && errno != EEXIST)
1616 return log_error_errno(-errno, errno, "Failed to create console");
1617
1618 ret = fchmod(console->pts, S_IXUSR | S_IXGRP);
1619 if (ret < 0)
1620 return log_error_errno(-errno, errno, "Failed to set mode \"0%o\" to \"%s\"", S_IXUSR | S_IXGRP, console->name);
1621
1622 if (pts_mnt_fd >= 0) {
1623 ret = move_mount(pts_mnt_fd, "", -EBADF, path, MOVE_MOUNT_F_EMPTY_PATH);
1624 if (!ret) {
1625 DEBUG("Moved mount \"%s\" onto \"%s\"", console->name, path);
1626 goto finish;
1627 }
1628
1629 if (ret && errno != ENOSYS)
1630 return log_error_errno(-1, errno,
1631 "Failed to mount %d(%s) on \"%s\"",
1632 pts_mnt_fd, console->name, path);
1633 }
1634
1635 ret = safe_mount(console->name, path, "none", MS_BIND, 0, rootfs_path);
1636 if (ret < 0)
1637 return log_error_errno(-1, errno, "Failed to mount %d(%s) on \"%s\"", pts_mnt_fd, console->name, path);
1638
1639finish:
1640 DEBUG("Mounted pts device %d(%s) onto \"%s\"", pts_mnt_fd, console->name, path);
1641 return 0;
1642}
1643
1644static int lxc_setup_ttydir_console(const struct lxc_rootfs *rootfs,
1645 const struct lxc_terminal *console,
1646 char *ttydir, int pts_mnt_fd)
1647{
1648 int ret;
1649 char path[PATH_MAX], lxcpath[PATH_MAX];
1650 char *rootfs_path = rootfs->path ? rootfs->mount : "";
1651
1652 if (!wants_console(console))
1653 return 0;
1654
1655 /* create rootfs/dev/<ttydir> directory */
1656 ret = snprintf(path, sizeof(path), "%s/dev/%s", rootfs_path, ttydir);
1657 if (ret < 0 || (size_t)ret >= sizeof(path))
1658 return -1;
1659
1660 ret = mkdir(path, 0755);
1661 if (ret && errno != EEXIST)
1662 return log_error_errno(-errno, errno, "Failed to create \"%s\"", path);
1663 DEBUG("Created directory for console and tty devices at \"%s\"", path);
1664
1665 ret = snprintf(lxcpath, sizeof(lxcpath), "%s/dev/%s/console", rootfs_path, ttydir);
1666 if (ret < 0 || (size_t)ret >= sizeof(lxcpath))
1667 return -1;
1668
1669 ret = mknod(lxcpath, S_IFREG | 0000, 0);
1670 if (ret < 0 && errno != EEXIST)
1671 return log_error_errno(-errno, errno, "Failed to create \"%s\"", lxcpath);
1672
1673 ret = snprintf(path, sizeof(path), "%s/dev/console", rootfs_path);
1674 if (ret < 0 || (size_t)ret >= sizeof(path))
1675 return -1;
1676
1677 if (file_exists(path)) {
1678 ret = lxc_unstack_mountpoint(path, false);
1679 if (ret < 0)
1680 return log_error_errno(-ret, errno, "Failed to unmount \"%s\"", path);
1681 else
1682 DEBUG("Cleared all (%d) mounts from \"%s\"", ret, path);
1683 }
1684
1685 ret = mknod(path, S_IFREG | 0000, 0);
1686 if (ret < 0 && errno != EEXIST)
1687 return log_error_errno(-errno, errno, "Failed to create console");
1688
1689 ret = fchmod(console->pts, S_IXUSR | S_IXGRP);
1690 if (ret < 0)
1691 return log_error_errno(-errno, errno, "Failed to set mode \"0%o\" to \"%s\"", S_IXUSR | S_IXGRP, console->name);
1692
1693 /* bind mount console->name to '/dev/<ttydir>/console' */
1694 if (pts_mnt_fd >= 0) {
1695 ret = move_mount(pts_mnt_fd, "", -EBADF, lxcpath, MOVE_MOUNT_F_EMPTY_PATH);
1696 if (!ret) {
1697 DEBUG("Moved mount \"%s\" onto \"%s\"", console->name, lxcpath);
1698 goto finish;
1699 }
1700
1701 if (ret && errno != ENOSYS)
1702 return log_error_errno(-1, errno,
1703 "Failed to mount %d(%s) on \"%s\"",
1704 pts_mnt_fd, console->name, lxcpath);
1705 }
1706
1707 ret = safe_mount(console->name, lxcpath, "none", MS_BIND, 0, rootfs_path);
1708 if (ret < 0)
1709 return log_error_errno(-1, errno, "Failed to mount %d(%s) on \"%s\"", pts_mnt_fd, console->name, lxcpath);
1710 DEBUG("Mounted \"%s\" onto \"%s\"", console->name, lxcpath);
1711
1712finish:
1713 /* bind mount '/dev/<ttydir>/console' to '/dev/console' */
1714 ret = safe_mount(lxcpath, path, "none", MS_BIND, 0, rootfs_path);
1715 if (ret < 0)
1716 return log_error_errno(-1, errno, "Failed to mount \"%s\" on \"%s\"", console->name, lxcpath);
1717 DEBUG("Mounted \"%s\" onto \"%s\"", console->name, lxcpath);
1718
1719 DEBUG("Console has been setup under \"%s\" and mounted to \"%s\"", lxcpath, path);
1720 return 0;
1721}
1722
1723static int lxc_setup_console(const struct lxc_rootfs *rootfs,
1724 const struct lxc_terminal *console, char *ttydir,
1725 int pts_mnt_fd)
1726{
1727
1728 if (!ttydir)
1729 return lxc_setup_dev_console(rootfs, console, pts_mnt_fd);
1730
1731 return lxc_setup_ttydir_console(rootfs, console, ttydir, pts_mnt_fd);
1732}
1733
1734static int parse_mntopt(char *opt, unsigned long *flags, char **data, size_t size)
1735{
1736 ssize_t ret;
1737
1738 /* If '=' is contained in opt, the option must go into data. */
1739 if (!strchr(opt, '=')) {
1740 /*
1741 * If opt is found in mount_opt, set or clear flags.
1742 * Otherwise append it to data.
1743 */
1744 size_t opt_len = strlen(opt);
1745 for (struct mount_opt *mo = &mount_opt[0]; mo->name != NULL; mo++) {
1746 size_t mo_name_len = strlen(mo->name);
1747
1748 if (opt_len == mo_name_len && strncmp(opt, mo->name, mo_name_len) == 0) {
1749 if (mo->clear)
1750 *flags &= ~mo->flag;
1751 else
1752 *flags |= mo->flag;
1753 return 0;
1754 }
1755 }
1756 }
1757
1758 if (strlen(*data)) {
1759 ret = strlcat(*data, ",", size);
1760 if (ret < 0)
1761 return log_error_errno(ret, errno, "Failed to append \",\" to %s", *data);
1762 }
1763
1764 ret = strlcat(*data, opt, size);
1765 if (ret < 0)
1766 return log_error_errno(ret, errno, "Failed to append \"%s\" to %s", opt, *data);
1767
1768 return 0;
1769}
1770
1771int parse_mntopts(const char *mntopts, unsigned long *mntflags, char **mntdata)
1772{
1773 __do_free char *mntopts_new = NULL, *mntopts_dup = NULL;
1774 char *mntopt_cur = NULL;
1775 size_t size;
1776
1777 if (*mntdata || *mntflags)
1778 return ret_errno(EINVAL);
1779
1780 if (!mntopts)
1781 return 0;
1782
1783 mntopts_dup = strdup(mntopts);
1784 if (!mntopts_dup)
1785 return ret_errno(ENOMEM);
1786
1787 size = strlen(mntopts_dup) + 1;
1788 mntopts_new = zalloc(size);
1789 if (!mntopts_new)
1790 return ret_errno(ENOMEM);
1791
1792 lxc_iterate_parts(mntopt_cur, mntopts_dup, ",")
1793 if (parse_mntopt(mntopt_cur, mntflags, &mntopts_new, size) < 0)
1794 return ret_errno(EINVAL);
1795
1796 if (*mntopts_new)
1797 *mntdata = move_ptr(mntopts_new);
1798
1799 return 0;
1800}
1801
1802static void parse_propagationopt(char *opt, unsigned long *flags)
1803{
1804 struct mount_opt *mo;
1805
1806 /* If opt is found in propagation_opt, set or clear flags. */
1807 for (mo = &propagation_opt[0]; mo->name != NULL; mo++) {
1808 if (strncmp(opt, mo->name, strlen(mo->name)) != 0)
1809 continue;
1810
1811 if (mo->clear)
1812 *flags &= ~mo->flag;
1813 else
1814 *flags |= mo->flag;
1815
1816 return;
1817 }
1818}
1819
1820int parse_propagationopts(const char *mntopts, unsigned long *pflags)
1821{
1822 __do_free char *s = NULL;
1823 char *p;
1824
1825 if (!mntopts)
1826 return 0;
1827
1828 s = strdup(mntopts);
1829 if (!s)
1830 return log_error_errno(-ENOMEM, errno, "Failed to allocate memory");
1831
1832 *pflags = 0L;
1833 lxc_iterate_parts(p, s, ",")
1834 parse_propagationopt(p, pflags);
1835
1836 return 0;
1837}
1838
1839static void null_endofword(char *word)
1840{
1841 while (*word && *word != ' ' && *word != '\t')
1842 word++;
1843 *word = '\0';
1844}
1845
1846/* skip @nfields spaces in @src */
1847static char *get_field(char *src, int nfields)
1848{
1849 int i;
1850 char *p = src;
1851
1852 for (i = 0; i < nfields; i++) {
1853 while (*p && *p != ' ' && *p != '\t')
1854 p++;
1855
1856 if (!*p)
1857 break;
1858
1859 p++;
1860 }
1861
1862 return p;
1863}
1864
1865static int mount_entry(const char *fsname, const char *target,
1866 const char *fstype, unsigned long mountflags,
1867 unsigned long pflags, const char *data, bool optional,
1868 bool dev, bool relative, const char *rootfs)
1869{
1870 int ret;
1871 char srcbuf[PATH_MAX];
1872 const char *srcpath = fsname;
1873#ifdef HAVE_STATVFS
1874 struct statvfs sb;
1875#endif
1876
1877 if (relative) {
1878 ret = snprintf(srcbuf, sizeof(srcbuf), "%s/%s", rootfs ? rootfs : "/", fsname ? fsname : "");
1879 if (ret < 0 || ret >= sizeof(srcbuf))
1880 return log_error_errno(-1, errno, "source path is too long");
1881 srcpath = srcbuf;
1882 }
1883
1884 ret = safe_mount(srcpath, target, fstype, mountflags & ~MS_REMOUNT, data,
1885 rootfs);
1886 if (ret < 0) {
1887 if (optional)
1888 return log_info_errno(0, errno, "Failed to mount \"%s\" on \"%s\" (optional)",
1889 srcpath ? srcpath : "(null)", target);
1890
1891 return log_error_errno(-1, errno, "Failed to mount \"%s\" on \"%s\"",
1892 srcpath ? srcpath : "(null)", target);
1893 }
1894
1895 if ((mountflags & MS_REMOUNT) || (mountflags & MS_BIND)) {
1896
1897 DEBUG("Remounting \"%s\" on \"%s\" to respect bind or remount options",
1898 srcpath ? srcpath : "(none)", target ? target : "(none)");
1899
1900#ifdef HAVE_STATVFS
1901 if (srcpath && statvfs(srcpath, &sb) == 0) {
1902 unsigned long required_flags = 0;
1903
1904 if (sb.f_flag & MS_NOSUID)
1905 required_flags |= MS_NOSUID;
1906
1907 if (sb.f_flag & MS_NODEV && !dev)
1908 required_flags |= MS_NODEV;
1909
1910 if (sb.f_flag & MS_RDONLY)
1911 required_flags |= MS_RDONLY;
1912
1913 if (sb.f_flag & MS_NOEXEC)
1914 required_flags |= MS_NOEXEC;
1915
1916 DEBUG("Flags for \"%s\" were %lu, required extra flags are %lu",
1917 srcpath, sb.f_flag, required_flags);
1918
1919 /* If this was a bind mount request, and required_flags
1920 * does not have any flags which are not already in
1921 * mountflags, then skip the remount.
1922 */
1923 if (!(mountflags & MS_REMOUNT) &&
1924 (!(required_flags & ~mountflags) && !(mountflags & MS_RDONLY))) {
1925 DEBUG("Mountflags already were %lu, skipping remount", mountflags);
1926 goto skipremount;
1927 }
1928
1929 mountflags |= required_flags;
1930 }
1931#endif
1932
1933 ret = mount(srcpath, target, fstype, mountflags | MS_REMOUNT, data);
1934 if (ret < 0) {
1935 if (optional)
1936 return log_info_errno(0, errno, "Failed to mount \"%s\" on \"%s\" (optional)",
1937 srcpath ? srcpath : "(null)",
1938 target);
1939
1940 return log_error_errno(-1, errno, "Failed to mount \"%s\" on \"%s\"",
1941 srcpath ? srcpath : "(null)",
1942 target);
1943 }
1944 }
1945
1946#ifdef HAVE_STATVFS
1947skipremount:
1948#endif
1949 if (pflags) {
1950 ret = mount(NULL, target, NULL, pflags, NULL);
1951 if (ret < 0) {
1952 if (optional)
1953 return log_info_errno(0, errno, "Failed to change mount propagation for \"%s\" (optional)", target);
1954 else
1955 return log_error_errno(-1, errno, "Failed to change mount propagation for \"%s\" (optional)", target);
1956 }
1957 DEBUG("Changed mount propagation for \"%s\"", target);
1958 }
1959
1960 DEBUG("Mounted \"%s\" on \"%s\" with filesystem type \"%s\"",
1961 srcpath ? srcpath : "(null)", target, fstype);
1962
1963 return 0;
1964}
1965
1966/* Remove "optional", "create=dir", and "create=file" from mntopt */
1967static void cull_mntent_opt(struct mntent *mntent)
1968{
1969 int i;
1970 char *list[] = {
1971 "create=dir",
1972 "create=file",
1973 "optional",
1974 "relative",
1975 NULL
1976 };
1977
1978 for (i = 0; list[i]; i++) {
1979 char *p, *p2;
1980
1981 p = strstr(mntent->mnt_opts, list[i]);
1982 if (!p)
1983 continue;
1984
1985 p2 = strchr(p, ',');
1986 if (!p2) {
1987 /* no more mntopts, so just chop it here */
1988 *p = '\0';
1989 continue;
1990 }
1991
1992 memmove(p, p2 + 1, strlen(p2 + 1) + 1);
1993 }
1994}
1995
1996static int mount_entry_create_dir_file(const struct mntent *mntent,
1997 const char *path,
1998 const struct lxc_rootfs *rootfs,
1999 const char *lxc_name, const char *lxc_path)
2000{
2001 __do_free char *p1 = NULL;
2002 int ret;
2003 char *p2;
2004
2005 if (strncmp(mntent->mnt_type, "overlay", 7) == 0) {
2006 ret = ovl_mkdir(mntent, rootfs, lxc_name, lxc_path);
2007 if (ret < 0)
2008 return -1;
2009 }
2010
2011 if (hasmntopt(mntent, "create=dir")) {
2012 ret = mkdir_p(path, 0755);
2013 if (ret < 0 && errno != EEXIST)
2014 return log_error_errno(-1, errno, "Failed to create directory \"%s\"", path);
2015 }
2016
2017 if (!hasmntopt(mntent, "create=file"))
2018 return 0;
2019
2020 ret = access(path, F_OK);
2021 if (ret == 0)
2022 return 0;
2023
2024 p1 = strdup(path);
2025 if (!p1)
2026 return -1;
2027
2028 p2 = dirname(p1);
2029
2030 ret = mkdir_p(p2, 0755);
2031 if (ret < 0 && errno != EEXIST)
2032 return log_error_errno(-1, errno, "Failed to create directory \"%s\"", path);
2033
2034 ret = mknod(path, S_IFREG | 0000, 0);
2035 if (ret < 0 && errno != EEXIST)
2036 return -errno;
2037
2038 return 0;
2039}
2040
2041/* rootfs, lxc_name, and lxc_path can be NULL when the container is created
2042 * without a rootfs. */
2043static inline int mount_entry_on_generic(struct mntent *mntent,
2044 const char *path,
2045 const struct lxc_rootfs *rootfs,
2046 const char *lxc_name,
2047 const char *lxc_path)
2048{
2049 __do_free char *mntdata = NULL;
2050 unsigned long mntflags = 0, pflags = 0;
2051 char *rootfs_path = NULL;
2052 int ret;
2053 bool dev, optional, relative;
2054
2055 optional = hasmntopt(mntent, "optional") != NULL;
2056 dev = hasmntopt(mntent, "dev") != NULL;
2057 relative = hasmntopt(mntent, "relative") != NULL;
2058
2059 if (rootfs && rootfs->path)
2060 rootfs_path = rootfs->mount;
2061
2062 ret = mount_entry_create_dir_file(mntent, path, rootfs, lxc_name,
2063 lxc_path);
2064 if (ret < 0) {
2065 if (optional)
2066 return 0;
2067
2068 return -1;
2069 }
2070 cull_mntent_opt(mntent);
2071
2072 ret = parse_propagationopts(mntent->mnt_opts, &pflags);
2073 if (ret < 0)
2074 return -1;
2075
2076 ret = parse_mntopts(mntent->mnt_opts, &mntflags, &mntdata);
2077 if (ret < 0)
2078 return ret;
2079
2080 ret = mount_entry(mntent->mnt_fsname, path, mntent->mnt_type, mntflags,
2081 pflags, mntdata, optional, dev, relative, rootfs_path);
2082
2083 return ret;
2084}
2085
2086static inline int mount_entry_on_systemfs(struct mntent *mntent)
2087{
2088 int ret;
2089 char path[PATH_MAX];
2090
2091 /* For containers created without a rootfs all mounts are treated as
2092 * absolute paths starting at / on the host.
2093 */
2094 if (mntent->mnt_dir[0] != '/')
2095 ret = snprintf(path, sizeof(path), "/%s", mntent->mnt_dir);
2096 else
2097 ret = snprintf(path, sizeof(path), "%s", mntent->mnt_dir);
2098 if (ret < 0 || ret >= sizeof(path))
2099 return -1;
2100
2101 return mount_entry_on_generic(mntent, path, NULL, NULL, NULL);
2102}
2103
2104static int mount_entry_on_absolute_rootfs(struct mntent *mntent,
2105 const struct lxc_rootfs *rootfs,
2106 const char *lxc_name,
2107 const char *lxc_path)
2108{
2109 int offset;
2110 char *aux;
2111 const char *lxcpath;
2112 char path[PATH_MAX];
2113 int ret = 0;
2114
2115 lxcpath = lxc_global_config_value("lxc.lxcpath");
2116 if (!lxcpath)
2117 return -1;
2118
2119 /* If rootfs->path is a blockdev path, allow container fstab to use
2120 * <lxcpath>/<name>/rootfs" as the target prefix.
2121 */
2122 ret = snprintf(path, PATH_MAX, "%s/%s/rootfs", lxcpath, lxc_name);
2123 if (ret < 0 || ret >= PATH_MAX)
2124 goto skipvarlib;
2125
2126 aux = strstr(mntent->mnt_dir, path);
2127 if (aux) {
2128 offset = strlen(path);
2129 goto skipabs;
2130 }
2131
2132skipvarlib:
2133 aux = strstr(mntent->mnt_dir, rootfs->path);
2134 if (!aux)
2135 return log_warn(ret, "Ignoring mount point \"%s\"", mntent->mnt_dir);
2136 offset = strlen(rootfs->path);
2137
2138skipabs:
2139 ret = snprintf(path, PATH_MAX, "%s/%s", rootfs->mount, aux + offset);
2140 if (ret < 0 || ret >= PATH_MAX)
2141 return -1;
2142
2143 return mount_entry_on_generic(mntent, path, rootfs, lxc_name, lxc_path);
2144}
2145
2146static int mount_entry_on_relative_rootfs(struct mntent *mntent,
2147 const struct lxc_rootfs *rootfs,
2148 const char *lxc_name,
2149 const char *lxc_path)
2150{
2151 int ret;
2152 char path[PATH_MAX];
2153
2154 /* relative to root mount point */
2155 ret = snprintf(path, sizeof(path), "%s/%s", rootfs->mount, mntent->mnt_dir);
2156 if (ret < 0 || (size_t)ret >= sizeof(path))
2157 return -1;
2158
2159 return mount_entry_on_generic(mntent, path, rootfs, lxc_name, lxc_path);
2160}
2161
2162static int mount_file_entries(const struct lxc_conf *conf,
2163 const struct lxc_rootfs *rootfs, FILE *file,
2164 const char *lxc_name, const char *lxc_path)
2165{
2166 char buf[PATH_MAX];
2167 struct mntent mntent;
2168
2169 while (getmntent_r(file, &mntent, buf, sizeof(buf))) {
2170 int ret;
2171
2172 if (!rootfs->path)
2173 ret = mount_entry_on_systemfs(&mntent);
2174 else if (mntent.mnt_dir[0] != '/')
2175 ret = mount_entry_on_relative_rootfs(&mntent, rootfs,
2176 lxc_name, lxc_path);
2177 else
2178 ret = mount_entry_on_absolute_rootfs(&mntent, rootfs,
2179 lxc_name, lxc_path);
2180 if (ret < 0)
2181 return -1;
2182 }
2183
2184 if (!feof(file) || ferror(file))
2185 return log_error(-1, "Failed to parse mount entries");
2186
2187 return 0;
2188}
2189
2190static inline void __auto_endmntent__(FILE **f)
2191{
2192 if (*f)
2193 endmntent(*f);
2194}
2195
2196#define __do_endmntent __attribute__((__cleanup__(__auto_endmntent__)))
2197
2198static int setup_mount(const struct lxc_conf *conf,
2199 const struct lxc_rootfs *rootfs, const char *fstab,
2200 const char *lxc_name, const char *lxc_path)
2201{
2202 __do_endmntent FILE *f = NULL;
2203 int ret;
2204
2205 if (!fstab)
2206 return 0;
2207
2208 f = setmntent(fstab, "re");
2209 if (!f)
2210 return log_error_errno(-1, errno, "Failed to open \"%s\"", fstab);
2211
2212 ret = mount_file_entries(conf, rootfs, f, lxc_name, lxc_path);
2213 if (ret < 0)
2214 ERROR("Failed to set up mount entries");
2215
2216 return ret;
2217}
2218
2219/*
2220 * In order for nested containers to be able to mount /proc and /sys they need
2221 * to see a "pure" proc and sysfs mount points with nothing mounted on top
2222 * (like lxcfs).
2223 * For this we provide proc and sysfs in /dev/.lxc/{proc,sys} while using an
2224 * apparmor rule to deny access to them. This is mostly for convenience: The
2225 * container's root user can mount them anyway and thus has access to the two
2226 * file systems. But a non-root user in the container should not be allowed to
2227 * access them as a side effect without explicitly allowing it.
2228 */
2229static const char nesting_helpers[] =
2230"proc dev/.lxc/proc proc create=dir,optional 0 0\n"
2231"sys dev/.lxc/sys sysfs create=dir,optional 0 0\n";
2232
2233FILE *make_anonymous_mount_file(struct lxc_list *mount,
2234 bool include_nesting_helpers)
2235{
2236 __do_close int fd = -EBADF;
2237 FILE *f;
2238 int ret;
2239 char *mount_entry;
2240 struct lxc_list *iterator;
2241
2242 fd = memfd_create(".lxc_mount_file", MFD_CLOEXEC);
2243 if (fd < 0) {
2244 char template[] = P_tmpdir "/.lxc_mount_file_XXXXXX";
2245
2246 if (errno != ENOSYS)
2247 return NULL;
2248
2249 fd = lxc_make_tmpfile(template, true);
2250 if (fd < 0)
2251 return log_error_errno(NULL, errno, "Could not create temporary mount file");
2252
2253 TRACE("Created temporary mount file");
2254 }
2255
2256 lxc_list_for_each (iterator, mount) {
2257 size_t len;
2258
2259 mount_entry = iterator->elem;
2260 len = strlen(mount_entry);
2261
2262 ret = lxc_write_nointr(fd, mount_entry, len);
2263 if (ret != len)
2264 return NULL;
2265
2266 ret = lxc_write_nointr(fd, "\n", 1);
2267 if (ret != 1)
2268 return NULL;
2269 }
2270
2271 if (include_nesting_helpers) {
2272 ret = lxc_write_nointr(fd, nesting_helpers,
2273 STRARRAYLEN(nesting_helpers));
2274 if (ret != STRARRAYLEN(nesting_helpers))
2275 return NULL;
2276 }
2277
2278 ret = lseek(fd, 0, SEEK_SET);
2279 if (ret < 0)
2280 return NULL;
2281
2282 f = fdopen(fd, "re+");
2283 if (f)
2284 move_fd(fd); /* Transfer ownership of fd. */
2285 return f;
2286}
2287
2288static int setup_mount_entries(const struct lxc_conf *conf,
2289 const struct lxc_rootfs *rootfs,
2290 struct lxc_list *mount, const char *lxc_name,
2291 const char *lxc_path)
2292{
2293 __do_fclose FILE *f = NULL;
2294
2295 f = make_anonymous_mount_file(mount, conf->lsm_aa_allow_nesting);
2296 if (!f)
2297 return -1;
2298
2299 return mount_file_entries(conf, rootfs, f, lxc_name, lxc_path);
2300}
2301
2302static int parse_cap(const char *cap)
2303{
2304 size_t i;
2305 int capid = -1;
2306 size_t end = sizeof(caps_opt) / sizeof(caps_opt[0]);
2307 char *ptr = NULL;
2308
2309 if (strcmp(cap, "none") == 0)
2310 return -2;
2311
2312 for (i = 0; i < end; i++) {
2313 if (strcmp(cap, caps_opt[i].name))
2314 continue;
2315
2316 capid = caps_opt[i].value;
2317 break;
2318 }
2319
2320 if (capid < 0) {
2321 /* Try to see if it's numeric, so the user may specify
2322 * capabilities that the running kernel knows about but we
2323 * don't
2324 */
2325 errno = 0;
2326 capid = strtol(cap, &ptr, 10);
2327 if (!ptr || *ptr != '\0' || errno != 0)
2328 /* not a valid number */
2329 capid = -1;
2330 else if (capid > lxc_caps_last_cap())
2331 /* we have a number but it's not a valid
2332 * capability */
2333 capid = -1;
2334 }
2335
2336 return capid;
2337}
2338
2339int in_caplist(int cap, struct lxc_list *caps)
2340{
2341 int capid;
2342 struct lxc_list *iterator;
2343
2344 lxc_list_for_each (iterator, caps) {
2345 capid = parse_cap(iterator->elem);
2346 if (capid == cap)
2347 return 1;
2348 }
2349
2350 return 0;
2351}
2352
2353static int setup_caps(struct lxc_list *caps)
2354{
2355 int capid;
2356 char *drop_entry;
2357 struct lxc_list *iterator;
2358
2359 lxc_list_for_each (iterator, caps) {
2360 int ret;
2361
2362 drop_entry = iterator->elem;
2363
2364 capid = parse_cap(drop_entry);
2365 if (capid < 0)
2366 return log_error(-1, "unknown capability %s", drop_entry);
2367
2368 ret = prctl(PR_CAPBSET_DROP, prctl_arg(capid), prctl_arg(0),
2369 prctl_arg(0), prctl_arg(0));
2370 if (ret < 0)
2371 return log_error_errno(-1, errno, "Failed to remove %s capability", drop_entry);
2372 DEBUG("Dropped %s (%d) capability", drop_entry, capid);
2373 }
2374
2375 DEBUG("Capabilities have been setup");
2376 return 0;
2377}
2378
2379static int dropcaps_except(struct lxc_list *caps)
2380{
2381 __do_free int *caplist = NULL;
2382 int i, capid, numcaps;
2383 char *keep_entry;
2384 struct lxc_list *iterator;
2385
2386 numcaps = lxc_caps_last_cap() + 1;
2387 if (numcaps <= 0 || numcaps > 200)
2388 return -1;
2389 TRACE("Found %d capabilities", numcaps);
2390
2391 /* caplist[i] is 1 if we keep capability i */
2392 caplist = must_realloc(NULL, numcaps * sizeof(int));
2393 memset(caplist, 0, numcaps * sizeof(int));
2394
2395 lxc_list_for_each (iterator, caps) {
2396 keep_entry = iterator->elem;
2397
2398 capid = parse_cap(keep_entry);
2399 if (capid == -2)
2400 continue;
2401
2402 if (capid < 0)
2403 return log_error(-1, "Unknown capability %s", keep_entry);
2404
2405 DEBUG("Keep capability %s (%d)", keep_entry, capid);
2406 caplist[capid] = 1;
2407 }
2408
2409 for (i = 0; i < numcaps; i++) {
2410 int ret;
2411
2412 if (caplist[i])
2413 continue;
2414
2415 ret = prctl(PR_CAPBSET_DROP, prctl_arg(i), prctl_arg(0),
2416 prctl_arg(0), prctl_arg(0));
2417 if (ret < 0)
2418 return log_error_errno(-1, errno, "Failed to remove capability %d", i);
2419 }
2420
2421 DEBUG("Capabilities have been setup");
2422 return 0;
2423}
2424
2425static int parse_resource(const char *res)
2426{
2427 int ret;
2428 size_t i;
2429 int resid = -1;
2430
2431 for (i = 0; i < sizeof(limit_opt) / sizeof(limit_opt[0]); ++i)
2432 if (strcmp(res, limit_opt[i].name) == 0)
2433 return limit_opt[i].value;
2434
2435 /* Try to see if it's numeric, so the user may specify
2436 * resources that the running kernel knows about but
2437 * we don't.
2438 */
2439 ret = lxc_safe_int(res, &resid);
2440 if (ret < 0)
2441 return -1;
2442
2443 return resid;
2444}
2445
2446int setup_resource_limits(struct lxc_list *limits, pid_t pid)
2447{
2448 int resid;
2449 struct lxc_list *it;
2450 struct lxc_limit *lim;
2451
2452 lxc_list_for_each (it, limits) {
2453 lim = it->elem;
2454
2455 resid = parse_resource(lim->resource);
2456 if (resid < 0)
2457 return log_error(-1, "Unknown resource %s", lim->resource);
2458
2459#if HAVE_PRLIMIT || HAVE_PRLIMIT64
2460 if (prlimit(pid, resid, &lim->limit, NULL) != 0)
2461 return log_error_errno(-1, errno, "Failed to set limit %s", lim->resource);
2462
2463 TRACE("Setup \"%s\" limit", lim->resource);
2464#else
2465 return log_error(-1, "Cannot set limit \"%s\" as prlimit is missing", lim->resource);
2466#endif
2467 }
2468
2469 return 0;
2470}
2471
2472int setup_sysctl_parameters(struct lxc_list *sysctls)
2473{
2474 __do_free char *tmp = NULL;
2475 struct lxc_list *it;
2476 struct lxc_sysctl *elem;
2477 int ret = 0;
2478 char filename[PATH_MAX] = {0};
2479
2480 lxc_list_for_each (it, sysctls) {
2481 elem = it->elem;
2482 tmp = lxc_string_replace(".", "/", elem->key);
2483 if (!tmp)
2484 return log_error(-1, "Failed to replace key %s", elem->key);
2485
2486 ret = snprintf(filename, sizeof(filename), "/proc/sys/%s", tmp);
2487 if (ret < 0 || (size_t)ret >= sizeof(filename))
2488 return log_error(-1, "Error setting up sysctl parameters path");
2489
2490 ret = lxc_write_to_file(filename, elem->value,
2491 strlen(elem->value), false, 0666);
2492 if (ret < 0)
2493 return log_error_errno(-1, errno, "Failed to setup sysctl parameters %s to %s",
2494 elem->key, elem->value);
2495 }
2496
2497 return 0;
2498}
2499
2500int setup_proc_filesystem(struct lxc_list *procs, pid_t pid)
2501{
2502 __do_free char *tmp = NULL;
2503 struct lxc_list *it;
2504 struct lxc_proc *elem;
2505 int ret = 0;
2506 char filename[PATH_MAX] = {0};
2507
2508 lxc_list_for_each (it, procs) {
2509 elem = it->elem;
2510 tmp = lxc_string_replace(".", "/", elem->filename);
2511 if (!tmp)
2512 return log_error(-1, "Failed to replace key %s", elem->filename);
2513
2514 ret = snprintf(filename, sizeof(filename), "/proc/%d/%s", pid, tmp);
2515 if (ret < 0 || (size_t)ret >= sizeof(filename))
2516 return log_error(-1, "Error setting up proc filesystem path");
2517
2518 ret = lxc_write_to_file(filename, elem->value,
2519 strlen(elem->value), false, 0666);
2520 if (ret < 0)
2521 return log_error_errno(-1, errno, "Failed to setup proc filesystem %s to %s", elem->filename, elem->value);
2522 }
2523
2524 return 0;
2525}
2526
2527static char *default_rootfs_mount = LXCROOTFSMOUNT;
2528
2529struct lxc_conf *lxc_conf_init(void)
2530{
2531 int i;
2532 struct lxc_conf *new;
2533
2534 new = malloc(sizeof(*new));
2535 if (!new)
2536 return NULL;
2537 memset(new, 0, sizeof(*new));
2538
2539 new->loglevel = LXC_LOG_LEVEL_NOTSET;
2540 new->personality = -1;
2541 new->autodev = 1;
2542 new->console.buffer_size = 0;
2543 new->console.log_path = NULL;
2544 new->console.log_fd = -1;
2545 new->console.log_size = 0;
2546 new->console.path = NULL;
2547 new->console.peer = -1;
2548 new->console.proxy.busy = -1;
2549 new->console.proxy.ptmx = -1;
2550 new->console.proxy.pts = -1;
2551 new->console.ptmx = -1;
2552 new->console.pts = -1;
2553 new->console.name[0] = '\0';
2554 memset(&new->console.ringbuf, 0, sizeof(struct lxc_ringbuf));
2555 new->maincmd_fd = -1;
2556 new->monitor_signal_pdeath = SIGKILL;
2557 new->nbd_idx = -1;
2558 new->rootfs.mount = strdup(default_rootfs_mount);
2559 if (!new->rootfs.mount) {
2560 free(new);
2561 return NULL;
2562 }
2563 new->rootfs.managed = true;
2564 new->logfd = -1;
2565 lxc_list_init(&new->cgroup);
2566 lxc_list_init(&new->cgroup2);
2567 lxc_list_init(&new->devices);
2568 lxc_list_init(&new->network);
2569 lxc_list_init(&new->mount_list);
2570 lxc_list_init(&new->caps);
2571 lxc_list_init(&new->keepcaps);
2572 lxc_list_init(&new->id_map);
2573 new->root_nsuid_map = NULL;
2574 new->root_nsgid_map = NULL;
2575 lxc_list_init(&new->includes);
2576 lxc_list_init(&new->aliens);
2577 lxc_list_init(&new->environment);
2578 lxc_list_init(&new->limits);
2579 lxc_list_init(&new->sysctls);
2580 lxc_list_init(&new->procs);
2581 new->hooks_version = 0;
2582 for (i = 0; i < NUM_LXC_HOOKS; i++)
2583 lxc_list_init(&new->hooks[i]);
2584 lxc_list_init(&new->groups);
2585 lxc_list_init(&new->state_clients);
2586 new->lsm_aa_profile = NULL;
2587 lxc_list_init(&new->lsm_aa_raw);
2588 new->lsm_se_context = NULL;
2589 new->lsm_se_keyring_context = NULL;
2590 new->keyring_disable_session = false;
2591 new->tmp_umount_proc = false;
2592 new->tmp_umount_proc = 0;
2593 new->shmount.path_host = NULL;
2594 new->shmount.path_cont = NULL;
2595
2596 /* if running in a new user namespace, init and COMMAND
2597 * default to running as UID/GID 0 when using lxc-execute */
2598 new->init_uid = 0;
2599 new->init_gid = 0;
2600 memset(&new->cgroup_meta, 0, sizeof(struct lxc_cgroup));
2601 memset(&new->ns_share, 0, sizeof(char *) * LXC_NS_MAX);
2602 memset(&new->timens, 0, sizeof(struct timens_offsets));
2603 seccomp_conf_init(new);
2604
2605 return new;
2606}
2607
2608int write_id_mapping(enum idtype idtype, pid_t pid, const char *buf,
2609 size_t buf_size)
2610{
2611 __do_close int fd = -EBADF;
2612 int ret;
2613 char path[PATH_MAX];
2614
2615 if (geteuid() != 0 && idtype == ID_TYPE_GID) {
2616 __do_close int setgroups_fd = -EBADF;
2617
2618 ret = snprintf(path, PATH_MAX, "/proc/%d/setgroups", pid);
2619 if (ret < 0 || ret >= PATH_MAX)
2620 return -E2BIG;
2621
2622 setgroups_fd = open(path, O_WRONLY);
2623 if (setgroups_fd < 0 && errno != ENOENT)
2624 return log_error_errno(-1, errno, "Failed to open \"%s\"", path);
2625
2626 if (setgroups_fd >= 0) {
2627 ret = lxc_write_nointr(setgroups_fd, "deny\n",
2628 STRLITERALLEN("deny\n"));
2629 if (ret != STRLITERALLEN("deny\n"))
2630 return log_error_errno(-1, errno, "Failed to write \"deny\" to \"/proc/%d/setgroups\"", pid);
2631 TRACE("Wrote \"deny\" to \"/proc/%d/setgroups\"", pid);
2632 }
2633 }
2634
2635 ret = snprintf(path, PATH_MAX, "/proc/%d/%cid_map", pid,
2636 idtype == ID_TYPE_UID ? 'u' : 'g');
2637 if (ret < 0 || ret >= PATH_MAX)
2638 return -E2BIG;
2639
2640 fd = open(path, O_WRONLY | O_CLOEXEC);
2641 if (fd < 0)
2642 return log_error_errno(-1, errno, "Failed to open \"%s\"", path);
2643
2644 ret = lxc_write_nointr(fd, buf, buf_size);
2645 if (ret != buf_size)
2646 return log_error_errno(-1, errno, "Failed to write %cid mapping to \"%s\"",
2647 idtype == ID_TYPE_UID ? 'u' : 'g', path);
2648
2649 return 0;
2650}
2651
2652/* Check whether a binary exist and has either CAP_SETUID, CAP_SETGID or both.
2653 *
2654 * @return 1 if functional binary was found
2655 * @return 0 if binary exists but is lacking privilege
2656 * @return -ENOENT if binary does not exist
2657 * @return -EINVAL if cap to check is neither CAP_SETUID nor CAP_SETGID
2658 */
2659static int idmaptool_on_path_and_privileged(const char *binary, cap_value_t cap)
2660{
2661 __do_free char *path = NULL;
2662 int ret;
2663 struct stat st;
2664
2665 errno = EINVAL;
2666 if (cap != CAP_SETUID && cap != CAP_SETGID)
2667 return -1;
2668
2669 errno = ENOENT;
2670 path = on_path(binary, NULL);
2671 if (!path)
2672 return -1;
2673
2674 ret = stat(path, &st);
2675 if (ret < 0)
2676 return -1;
2677
2678 /* Check if the binary is setuid. */
2679 if (st.st_mode & S_ISUID)
2680 return log_debug(1, "The binary \"%s\" does have the setuid bit set", path);
2681
2682#if HAVE_LIBCAP && LIBCAP_SUPPORTS_FILE_CAPABILITIES
2683 /* Check if it has the CAP_SETUID capability. */
2684 if ((cap & CAP_SETUID) &&
2685 lxc_file_cap_is_set(path, CAP_SETUID, CAP_EFFECTIVE) &&
2686 lxc_file_cap_is_set(path, CAP_SETUID, CAP_PERMITTED))
2687 return log_debug(1, "The binary \"%s\" has CAP_SETUID in its CAP_EFFECTIVE and CAP_PERMITTED sets", path);
2688
2689 /* Check if it has the CAP_SETGID capability. */
2690 if ((cap & CAP_SETGID) &&
2691 lxc_file_cap_is_set(path, CAP_SETGID, CAP_EFFECTIVE) &&
2692 lxc_file_cap_is_set(path, CAP_SETGID, CAP_PERMITTED))
2693 return log_debug(1, "The binary \"%s\" has CAP_SETGID in its CAP_EFFECTIVE and CAP_PERMITTED sets", path);
2694#else
2695 /* If we cannot check for file capabilities we need to give the benefit
2696 * of the doubt. Otherwise we might fail even though all the necessary
2697 * file capabilities are set.
2698 */
2699 DEBUG("Cannot check for file capabilities as full capability support is missing. Manual intervention needed");
2700#endif
2701
2702 return 1;
2703}
2704
2705int lxc_map_ids_exec_wrapper(void *args)
2706{
2707 execl("/bin/sh", "sh", "-c", (char *)args, (char *)NULL);
2708 return -1;
2709}
2710
2711int lxc_map_ids(struct lxc_list *idmap, pid_t pid)
2712{
2713 int fill, left;
2714 char u_or_g;
2715 char *pos;
2716 char cmd_output[PATH_MAX];
2717 struct id_map *map;
2718 struct lxc_list *iterator;
2719 enum idtype type;
2720 int ret = 0, gidmap = 0, uidmap = 0;
2721 char mapbuf[STRLITERALLEN("new@idmap") + STRLITERALLEN(" ") +
2722 INTTYPE_TO_STRLEN(pid_t) + STRLITERALLEN(" ") +
2723 LXC_IDMAPLEN] = {0};
2724 bool had_entry = false, use_shadow = false;
2725 int hostuid, hostgid;
2726
2727 hostuid = geteuid();
2728 hostgid = getegid();
2729
2730 /* If new{g,u}idmap exists, that is, if shadow is handing out subuid
2731 * ranges, then insist that root also reserve ranges in subuid. This
2732 * will protected it by preventing another user from being handed the
2733 * range by shadow.
2734 */
2735 uidmap = idmaptool_on_path_and_privileged("newuidmap", CAP_SETUID);
2736 if (uidmap == -ENOENT)
2737 WARN("newuidmap binary is missing");
2738 else if (!uidmap)
2739 WARN("newuidmap is lacking necessary privileges");
2740
2741 gidmap = idmaptool_on_path_and_privileged("newgidmap", CAP_SETGID);
2742 if (gidmap == -ENOENT)
2743 WARN("newgidmap binary is missing");
2744 else if (!gidmap)
2745 WARN("newgidmap is lacking necessary privileges");
2746
2747 if (uidmap > 0 && gidmap > 0) {
2748 DEBUG("Functional newuidmap and newgidmap binary found");
2749 use_shadow = true;
2750 } else {
2751 /* In case unprivileged users run application containers via
2752 * execute() or a start*() there are valid cases where they may
2753 * only want to map their own {g,u}id. Let's not block them from
2754 * doing so by requiring geteuid() == 0.
2755 */
2756 DEBUG("No newuidmap and newgidmap binary found. Trying to "
2757 "write directly with euid %d", hostuid);
2758 }
2759
2760 /* Check if we really need to use newuidmap and newgidmap.
2761 * If the user is only remapping his own {g,u}id, we don't need it.
2762 */
2763 if (use_shadow && lxc_list_len(idmap) == 2) {
2764 use_shadow = false;
2765 lxc_list_for_each(iterator, idmap) {
2766 map = iterator->elem;
2767 if (map->idtype == ID_TYPE_UID && map->range == 1 &&
2768 map->nsid == hostuid && map->hostid == hostuid)
2769 continue;
2770 if (map->idtype == ID_TYPE_GID && map->range == 1 &&
2771 map->nsid == hostgid && map->hostid == hostgid)
2772 continue;
2773 use_shadow = true;
2774 break;
2775 }
2776 }
2777
2778 for (type = ID_TYPE_UID, u_or_g = 'u'; type <= ID_TYPE_GID;
2779 type++, u_or_g = 'g') {
2780 pos = mapbuf;
2781
2782 if (use_shadow)
2783 pos += sprintf(mapbuf, "new%cidmap %d", u_or_g, pid);
2784
2785 lxc_list_for_each(iterator, idmap) {
2786 map = iterator->elem;
2787 if (map->idtype != type)
2788 continue;
2789
2790 had_entry = true;
2791
2792 left = LXC_IDMAPLEN - (pos - mapbuf);
2793 fill = snprintf(pos, left, "%s%lu %lu %lu%s",
2794 use_shadow ? " " : "", map->nsid,
2795 map->hostid, map->range,
2796 use_shadow ? "" : "\n");
2797 /*
2798 * The kernel only takes <= 4k for writes to
2799 * /proc/<pid>/{g,u}id_map
2800 */
2801 if (fill <= 0 || fill >= left)
2802 return log_error_errno(-1, errno, "Too many %cid mappings defined", u_or_g);
2803
2804 pos += fill;
2805 }
2806 if (!had_entry)
2807 continue;
2808
2809 /* Try to catch the output of new{g,u}idmap to make debugging
2810 * easier.
2811 */
2812 if (use_shadow) {
2813 ret = run_command(cmd_output, sizeof(cmd_output),
2814 lxc_map_ids_exec_wrapper,
2815 (void *)mapbuf);
2816 if (ret < 0)
2817 return log_error(-1, "new%cidmap failed to write mapping \"%s\": %s", u_or_g, cmd_output, mapbuf);
2818 TRACE("new%cidmap wrote mapping \"%s\"", u_or_g, mapbuf);
2819 } else {
2820 ret = write_id_mapping(type, pid, mapbuf, pos - mapbuf);
2821 if (ret < 0)
2822 return log_error(-1, "Failed to write mapping: %s", mapbuf);
2823 TRACE("Wrote mapping \"%s\"", mapbuf);
2824 }
2825
2826 memset(mapbuf, 0, sizeof(mapbuf));
2827 }
2828
2829 return 0;
2830}
2831
2832/*
2833 * Return the host uid/gid to which the container root is mapped in val.
2834 * Return true if id was found, false otherwise.
2835 */
2836static id_t get_mapped_rootid(const struct lxc_conf *conf, enum idtype idtype)
2837{
2838 unsigned nsid;
2839 struct id_map *map;
2840 struct lxc_list *it;
2841
2842 if (idtype == ID_TYPE_UID)
2843 nsid = (conf->root_nsuid_map != NULL) ? 0 : conf->init_uid;
2844 else
2845 nsid = (conf->root_nsgid_map != NULL) ? 0 : conf->init_gid;
2846
2847 lxc_list_for_each (it, &conf->id_map) {
2848 map = it->elem;
2849 if (map->idtype != idtype)
2850 continue;
2851 if (map->nsid != nsid)
2852 continue;
2853 return map->hostid;
2854 }
2855
2856 if (idtype == ID_TYPE_UID)
2857 return LXC_INVALID_UID;
2858
2859 return LXC_INVALID_GID;
2860}
2861
2862int mapped_hostid(unsigned id, const struct lxc_conf *conf, enum idtype idtype)
2863{
2864 struct id_map *map;
2865 struct lxc_list *it;
2866
2867 lxc_list_for_each (it, &conf->id_map) {
2868 map = it->elem;
2869 if (map->idtype != idtype)
2870 continue;
2871
2872 if (id >= map->hostid && id < map->hostid + map->range)
2873 return (id - map->hostid) + map->nsid;
2874 }
2875
2876 return -1;
2877}
2878
2879int find_unmapped_nsid(const struct lxc_conf *conf, enum idtype idtype)
2880{
2881 struct id_map *map;
2882 struct lxc_list *it;
2883 unsigned int freeid = 0;
2884
2885again:
2886 lxc_list_for_each (it, &conf->id_map) {
2887 map = it->elem;
2888 if (map->idtype != idtype)
2889 continue;
2890
2891 if (freeid >= map->nsid && freeid < map->nsid + map->range) {
2892 freeid = map->nsid + map->range;
2893 goto again;
2894 }
2895 }
2896
2897 return freeid;
2898}
2899
2900/* NOTE: Must not be called from inside the container namespace! */
2901int lxc_create_tmp_proc_mount(struct lxc_conf *conf)
2902{
2903 int mounted;
2904
2905 mounted = lxc_mount_proc_if_needed(conf->rootfs.path ? conf->rootfs.mount : "");
2906 if (mounted == -1) {
2907 SYSERROR("Failed to mount proc in the container");
2908 /* continue only if there is no rootfs */
2909 if (conf->rootfs.path)
2910 return -1;
2911 } else if (mounted == 1) {
2912 conf->tmp_umount_proc = true;
2913 }
2914
2915 return 0;
2916}
2917
2918void tmp_proc_unmount(struct lxc_conf *lxc_conf)
2919{
2920 if (!lxc_conf->tmp_umount_proc)
2921 return;
2922
2923 (void)umount2("/proc", MNT_DETACH);
2924 lxc_conf->tmp_umount_proc = false;
2925}
2926
2927/* Walk /proc/mounts and change any shared entries to dependent mounts. */
2928void turn_into_dependent_mounts(void)
2929{
2930 __do_free char *line = NULL;
2931 __do_fclose FILE *f = NULL;
2932 __do_close int memfd = -EBADF, mntinfo_fd = -EBADF;
2933 int ret;
2934 ssize_t copied;
2935 size_t len = 0;
2936
2937 mntinfo_fd = open("/proc/self/mountinfo", O_RDONLY | O_CLOEXEC);
2938 if (mntinfo_fd < 0) {
2939 SYSERROR("Failed to open \"/proc/self/mountinfo\"");
2940 return;
2941 }
2942
2943 memfd = memfd_create(".lxc_mountinfo", MFD_CLOEXEC);
2944 if (memfd < 0) {
2945 char template[] = P_tmpdir "/.lxc_mountinfo_XXXXXX";
2946
2947 if (errno != ENOSYS) {
2948 SYSERROR("Failed to create temporary in-memory file");
2949 return;
2950 }
2951
2952 memfd = lxc_make_tmpfile(template, true);
2953 if (memfd < 0) {
2954 WARN("Failed to create temporary file");
2955 return;
2956 }
2957 }
2958
2959again:
2960 copied = lxc_sendfile_nointr(memfd, mntinfo_fd, NULL, LXC_SENDFILE_MAX);
2961 if (copied < 0) {
2962 if (errno == EINTR)
2963 goto again;
2964
2965 SYSERROR("Failed to copy \"/proc/self/mountinfo\"");
2966 return;
2967 }
2968
2969 ret = lseek(memfd, 0, SEEK_SET);
2970 if (ret < 0) {
2971 SYSERROR("Failed to reset file descriptor offset");
2972 return;
2973 }
2974
2975 f = fdopen(memfd, "re");
2976 if (!f) {
2977 SYSERROR("Failed to open copy of \"/proc/self/mountinfo\" to mark all shared. Continuing");
2978 return;
2979 }
2980
2981 /*
2982 * After a successful fdopen() memfd will be closed when calling
2983 * fclose(f). Calling close(memfd) afterwards is undefined.
2984 */
2985 move_fd(memfd);
2986
2987 while (getline(&line, &len, f) != -1) {
2988 char *opts, *target;
2989
2990 target = get_field(line, 4);
2991 if (!target)
2992 continue;
2993
2994 opts = get_field(target, 2);
2995 if (!opts)
2996 continue;
2997
2998 null_endofword(opts);
2999 if (!strstr(opts, "shared"))
3000 continue;
3001
3002 null_endofword(target);
3003 ret = mount(NULL, target, NULL, MS_SLAVE, NULL);
3004 if (ret < 0) {
3005 SYSERROR("Failed to recursively turn old root mount tree into dependent mount. Continuing...");
3006 continue;
3007 }
3008 TRACE("Recursively turned old root mount tree into dependent mount");
3009 }
3010 TRACE("Turned all mount table entries into dependent mount");
3011}
3012
3013static int lxc_execute_bind_init(struct lxc_handler *handler)
3014{
3015 int ret;
3016 char *p;
3017 char path[PATH_MAX], destpath[PATH_MAX];
3018 struct lxc_conf *conf = handler->conf;
3019
3020 /* If init exists in the container, don't bind mount a static one */
3021 p = choose_init(conf->rootfs.mount);
3022 if (p) {
3023 __do_free char *old = p;
3024
3025 p = strdup(old + strlen(conf->rootfs.mount));
3026 if (!p)
3027 return -ENOMEM;
3028
3029 INFO("Found existing init at \"%s\"", p);
3030 goto out;
3031 }
3032
3033 ret = snprintf(path, PATH_MAX, SBINDIR "/init.lxc.static");
3034 if (ret < 0 || ret >= PATH_MAX)
3035 return -1;
3036
3037 if (!file_exists(path))
3038 return log_error_errno(-1, errno, "The file \"%s\" does not exist on host", path);
3039
3040 ret = snprintf(destpath, PATH_MAX, "%s" P_tmpdir "%s", conf->rootfs.mount, "/.lxc-init");
3041 if (ret < 0 || ret >= PATH_MAX)
3042 return -1;
3043
3044 if (!file_exists(destpath)) {
3045 ret = mknod(destpath, S_IFREG | 0000, 0);
3046 if (ret < 0 && errno != EEXIST)
3047 return log_error_errno(-1, errno, "Failed to create dummy \"%s\" file as bind mount target", destpath);
3048 }
3049
3050 ret = safe_mount(path, destpath, "none", MS_BIND, NULL, conf->rootfs.mount);
3051 if (ret < 0)
3052 return log_error_errno(-1, errno, "Failed to bind mount lxc.init.static into container");
3053
3054 p = strdup(destpath + strlen(conf->rootfs.mount));
3055 if (!p)
3056 return -ENOMEM;
3057
3058 INFO("Bind mounted lxc.init.static into container at \"%s\"", path);
3059out:
3060 ((struct execute_args *)handler->data)->init_fd = -1;
3061 ((struct execute_args *)handler->data)->init_path = p;
3062 return 0;
3063}
3064
3065/* This does the work of remounting / if it is shared, calling the container
3066 * pre-mount hooks, and mounting the rootfs.
3067 */
3068int lxc_setup_rootfs_prepare_root(struct lxc_conf *conf, const char *name,
3069 const char *lxcpath)
3070{
3071 int ret;
3072
3073 if (conf->rootfs_setup) {
3074 const char *path = conf->rootfs.mount;
3075
3076 /* The rootfs was set up in another namespace. bind-mount it to
3077 * give us a mount in our own ns so we can pivot_root to it
3078 */
3079 ret = mount(path, path, "rootfs", MS_BIND, NULL);
3080 if (ret < 0)
3081 return log_error(-1, "Failed to bind mount container / onto itself");
3082
3083 return log_trace(0, "Bind mounted container / onto itself");
3084 }
3085
3086 turn_into_dependent_mounts();
3087
3088 ret = run_lxc_hooks(name, "pre-mount", conf, NULL);
3089 if (ret < 0)
3090 return log_error(-1, "Failed to run pre-mount hooks");
3091
3092 ret = lxc_mount_rootfs(conf);
3093 if (ret < 0)
3094 return log_error(-1, "Failed to setup rootfs for");
3095
3096 conf->rootfs_setup = true;
3097 return 0;
3098}
3099
3100static bool verify_start_hooks(struct lxc_conf *conf)
3101{
3102 char path[PATH_MAX];
3103 struct lxc_list *it;
3104
3105 lxc_list_for_each (it, &conf->hooks[LXCHOOK_START]) {
3106 int ret;
3107 char *hookname = it->elem;
3108
3109 ret = snprintf(path, PATH_MAX, "%s%s",
3110 conf->rootfs.path ? conf->rootfs.mount : "",
3111 hookname);
3112 if (ret < 0 || ret >= PATH_MAX)
3113 return false;
3114
3115 ret = access(path, X_OK);
3116 if (ret < 0)
3117 return log_error_errno(false, errno, "Start hook \"%s\" not found in container", hookname);
3118
3119 return true;
3120 }
3121
3122 return true;
3123}
3124
3125static bool execveat_supported(void)
3126{
3127 execveat(-1, "", NULL, NULL, AT_EMPTY_PATH);
3128 if (errno == ENOSYS)
3129 return false;
3130
3131 return true;
3132}
3133
3134static int lxc_setup_boot_id(void)
3135{
3136 int ret;
3137 const char *boot_id_path = "/proc/sys/kernel/random/boot_id";
3138 const char *mock_boot_id_path = "/dev/.lxc-boot-id";
3139 lxc_id128_t n;
3140
3141 if (access(boot_id_path, F_OK))
3142 return 0;
3143
3144 memset(&n, 0, sizeof(n));
3145 if (lxc_id128_randomize(&n)) {
3146 SYSERROR("Failed to generate random data for uuid");
3147 return -1;
3148 }
3149
3150 ret = lxc_id128_write(mock_boot_id_path, n);
3151 if (ret < 0) {
3152 SYSERROR("Failed to write uuid to %s", mock_boot_id_path);
3153 return -1;
3154 }
3155
3156 ret = chmod(mock_boot_id_path, 0444);
3157 if (ret < 0) {
3158 SYSERROR("Failed to chown %s", mock_boot_id_path);
3159 (void)unlink(mock_boot_id_path);
3160 return -1;
3161 }
3162
3163 ret = mount(mock_boot_id_path, boot_id_path, NULL, MS_BIND, NULL);
3164 if (ret < 0) {
3165 SYSERROR("Failed to mount %s to %s", mock_boot_id_path,
3166 boot_id_path);
3167 (void)unlink(mock_boot_id_path);
3168 return -1;
3169 }
3170
3171 ret = mount(NULL, boot_id_path, NULL,
3172 (MS_BIND | MS_REMOUNT | MS_RDONLY | MS_NOSUID | MS_NOEXEC |
3173 MS_NODEV),
3174 NULL);
3175 if (ret < 0) {
3176 SYSERROR("Failed to remount %s read-only", boot_id_path);
3177 (void)unlink(mock_boot_id_path);
3178 return -1;
3179 }
3180
3181 return 0;
3182}
3183
3184int lxc_setup(struct lxc_handler *handler)
3185{
3186 __do_close int pts_mnt_fd = -EBADF;
3187 int ret;
3188 const char *lxcpath = handler->lxcpath, *name = handler->name;
3189 struct lxc_conf *lxc_conf = handler->conf;
3190 char *keyring_context = NULL;
3191
3192 ret = lxc_setup_rootfs_prepare_root(lxc_conf, name, lxcpath);
3193 if (ret < 0)
3194 return log_error(-1, "Failed to setup rootfs");
3195
3196 if (handler->nsfd[LXC_NS_UTS] == -EBADF) {
3197 ret = setup_utsname(lxc_conf->utsname);
3198 if (ret < 0)
3199 return log_error(-1, "Failed to setup the utsname %s", name);
3200 }
3201
3202 if (!lxc_conf->keyring_disable_session) {
3203 if (lxc_conf->lsm_se_keyring_context) {
3204 keyring_context = lxc_conf->lsm_se_keyring_context;
3205 } else if (lxc_conf->lsm_se_context) {
3206 keyring_context = lxc_conf->lsm_se_context;
3207 }
3208
3209 ret = lxc_setup_keyring(keyring_context);
3210 if (ret < 0)
3211 return -1;
3212 }
3213
3214 if (handler->ns_clone_flags & CLONE_NEWNET) {
3215 ret = lxc_setup_network_in_child_namespaces(lxc_conf,
3216 &lxc_conf->network);
3217 if (ret < 0)
3218 return log_error(-1, "Failed to setup network");
3219
3220 ret = lxc_network_send_name_and_ifindex_to_parent(handler);
3221 if (ret < 0)
3222 return log_error(-1, "Failed to send network device names and ifindices to parent");
3223 }
3224
3225 if (wants_console(&lxc_conf->console)) {
3226 pts_mnt_fd = open_tree(-EBADF, lxc_conf->console.name,
3227 OPEN_TREE_CLONE | OPEN_TREE_CLOEXEC | AT_EMPTY_PATH);
3228 if (pts_mnt_fd < 0)
3229 SYSTRACE("Failed to create detached mount for container's console \"%s\"",
3230 lxc_conf->console.name);
3231 else
3232 TRACE("Created detached mount for container's console \"%s\"",
3233 lxc_conf->console.name);
3234 }
3235
3236 if (lxc_conf->autodev > 0) {
3237 ret = mount_autodev(name, &lxc_conf->rootfs, lxc_conf->autodevtmpfssize, lxcpath);
3238 if (ret < 0)
3239 return log_error(-1, "Failed to mount \"/dev\"");
3240 }
3241
3242 /* Do automatic mounts (mainly /proc and /sys), but exclude those that
3243 * need to wait until other stuff has finished.
3244 */
3245 ret = lxc_mount_auto_mounts(lxc_conf, lxc_conf->auto_mounts & ~LXC_AUTO_CGROUP_MASK, handler);
3246 if (ret < 0)
3247 return log_error(-1, "Failed to setup first automatic mounts");
3248
3249 ret = setup_mount(lxc_conf, &lxc_conf->rootfs, lxc_conf->fstab, name, lxcpath);
3250 if (ret < 0)
3251 return log_error(-1, "Failed to setup mounts");
3252
3253 if (!lxc_list_empty(&lxc_conf->mount_list)) {
3254 ret = setup_mount_entries(lxc_conf, &lxc_conf->rootfs,
3255 &lxc_conf->mount_list, name, lxcpath);
3256 if (ret < 0)
3257 return log_error(-1, "Failed to setup mount entries");
3258 }
3259
3260 if (lxc_conf->is_execute) {
3261 if (execveat_supported()) {
3262 int fd;
3263 char path[PATH_MAX];
3264
3265 ret = snprintf(path, PATH_MAX, SBINDIR "/init.lxc.static");
3266 if (ret < 0 || ret >= PATH_MAX)
3267 return log_error(-1, "Path to init.lxc.static too long");
3268
3269 fd = open(path, O_PATH | O_CLOEXEC);
3270 if (fd < 0)
3271 return log_error_errno(-1, errno, "Unable to open lxc.init.static");
3272
3273 ((struct execute_args *)handler->data)->init_fd = fd;
3274 ((struct execute_args *)handler->data)->init_path = NULL;
3275 } else {
3276 ret = lxc_execute_bind_init(handler);
3277 if (ret < 0)
3278 return log_error(-1, "Failed to bind-mount the lxc init system");
3279 }
3280 }
3281
3282 /* Now mount only cgroups, if wanted. Before, /sys could not have been
3283 * mounted. It is guaranteed to be mounted now either through
3284 * automatically or via fstab entries.
3285 */
3286 ret = lxc_mount_auto_mounts(lxc_conf, lxc_conf->auto_mounts & LXC_AUTO_CGROUP_MASK, handler);
3287 if (ret < 0)
3288 return log_error(-1, "Failed to setup remaining automatic mounts");
3289
3290 ret = run_lxc_hooks(name, "mount", lxc_conf, NULL);
3291 if (ret < 0)
3292 return log_error(-1, "Failed to run mount hooks");
3293
3294 if (lxc_conf->autodev > 0) {
3295 ret = run_lxc_hooks(name, "autodev", lxc_conf, NULL);
3296 if (ret < 0)
3297 return log_error(-1, "Failed to run autodev hooks");
3298
3299 ret = lxc_fill_autodev(&lxc_conf->rootfs);
3300 if (ret < 0)
3301 return log_error(-1, "Failed to populate \"/dev\"");
3302 }
3303
3304 /* Make sure any start hooks are in the container */
3305 if (!verify_start_hooks(lxc_conf))
3306 return log_error(-1, "Failed to verify start hooks");
3307
3308 ret = lxc_create_tmp_proc_mount(lxc_conf);
3309 if (ret < 0)
3310 return log_error(-1, "Failed to \"/proc\" LSMs");
3311
3312 ret = lxc_setup_console(&lxc_conf->rootfs, &lxc_conf->console,
3313 lxc_conf->ttys.dir, pts_mnt_fd);
3314 if (ret < 0)
3315 return log_error(-1, "Failed to setup console");
3316
3317 ret = lxc_setup_dev_symlinks(&lxc_conf->rootfs);
3318 if (ret < 0)
3319 return log_error(-1, "Failed to setup \"/dev\" symlinks");
3320
3321 ret = lxc_setup_rootfs_switch_root(&lxc_conf->rootfs);
3322 if (ret < 0)
3323 return log_error(-1, "Failed to pivot root into rootfs");
3324
3325 /* Setting the boot-id is best-effort for now. */
3326 if (lxc_conf->autodev > 0)
3327 (void)lxc_setup_boot_id();
3328
3329 ret = lxc_setup_devpts(lxc_conf);
3330 if (ret < 0)
3331 return log_error(-1, "Failed to setup new devpts instance");
3332
3333 ret = lxc_create_ttys(handler);
3334 if (ret < 0)
3335 return -1;
3336
3337 ret = setup_personality(lxc_conf->personality);
3338 if (ret < 0)
3339 return log_error(-1, "Failed to set personality");
3340
3341 /* Set sysctl value to a path under /proc/sys as determined from the
3342 * key. For e.g. net.ipv4.ip_forward translated to
3343 * /proc/sys/net/ipv4/ip_forward.
3344 */
3345 if (!lxc_list_empty(&lxc_conf->sysctls)) {
3346 ret = setup_sysctl_parameters(&lxc_conf->sysctls);
3347 if (ret < 0)
3348 return log_error(-1, "Failed to setup sysctl parameters");
3349 }
3350
3351 if (!lxc_list_empty(&lxc_conf->keepcaps)) {
3352 if (!lxc_list_empty(&lxc_conf->caps))
3353 return log_error(-1, "Container requests lxc.cap.drop and lxc.cap.keep: either use lxc.cap.drop or lxc.cap.keep, not both");
3354
3355 if (dropcaps_except(&lxc_conf->keepcaps))
3356 return log_error(-1, "Failed to keep capabilities");
3357 } else if (setup_caps(&lxc_conf->caps)) {
3358 return log_error(-1, "Failed to drop capabilities");
3359 }
3360
3361 NOTICE("The container \"%s\" is set up", name);
3362
3363 return 0;
3364}
3365
3366int run_lxc_hooks(const char *name, char *hookname, struct lxc_conf *conf,
3367 char *argv[])
3368{
3369 struct lxc_list *it;
3370 int which;
3371
3372 for (which = 0; which < NUM_LXC_HOOKS; which ++) {
3373 if (strcmp(hookname, lxchook_names[which]) == 0)
3374 break;
3375 }
3376
3377 if (which >= NUM_LXC_HOOKS)
3378 return -1;
3379
3380 lxc_list_for_each (it, &conf->hooks[which]) {
3381 int ret;
3382 char *hook = it->elem;
3383
3384 ret = run_script_argv(name, conf->hooks_version, "lxc", hook,
3385 hookname, argv);
3386 if (ret < 0)
3387 return -1;
3388 }
3389
3390 return 0;
3391}
3392
3393int lxc_clear_config_caps(struct lxc_conf *c)
3394{
3395 struct lxc_list *it, *next;
3396
3397 lxc_list_for_each_safe (it, &c->caps, next) {
3398 lxc_list_del(it);
3399 free(it->elem);
3400 free(it);
3401 }
3402
3403 return 0;
3404}
3405
3406static int lxc_free_idmap(struct lxc_list *id_map)
3407{
3408 struct lxc_list *it, *next;
3409
3410 lxc_list_for_each_safe(it, id_map, next) {
3411 lxc_list_del(it);
3412 free(it->elem);
3413 free(it);
3414 }
3415
3416 return 0;
3417}
3418define_cleanup_function(struct lxc_list *, lxc_free_idmap);
3419
3420int lxc_clear_idmaps(struct lxc_conf *c)
3421{
3422 return lxc_free_idmap(&c->id_map);
3423}
3424
3425int lxc_clear_config_keepcaps(struct lxc_conf *c)
3426{
3427 struct lxc_list *it, *next;
3428
3429 lxc_list_for_each_safe (it, &c->keepcaps, next) {
3430 lxc_list_del(it);
3431 free(it->elem);
3432 free(it);
3433 }
3434
3435 return 0;
3436}
3437
3438int lxc_clear_namespace(struct lxc_conf *c)
3439{
3440 int i;
3441 for (i = 0; i < LXC_NS_MAX; i++) {
3442 free(c->ns_share[i]);
3443 c->ns_share[i] = NULL;
3444 }
3445 return 0;
3446}
3447
3448int lxc_clear_cgroups(struct lxc_conf *c, const char *key, int version)
3449{
3450 char *global_token, *namespaced_token;
3451 size_t namespaced_token_len;
3452 struct lxc_list *it, *next, *list;
3453 const char *k = key;
3454 bool all = false;
3455
3456 if (version == CGROUP2_SUPER_MAGIC) {
3457 global_token = "lxc.cgroup2";
3458 namespaced_token = "lxc.cgroup2.";
3459 namespaced_token_len = STRLITERALLEN("lxc.cgroup2.");
3460 list = &c->cgroup2;
3461 } else if (version == CGROUP_SUPER_MAGIC) {
3462 global_token = "lxc.cgroup";
3463 namespaced_token = "lxc.cgroup.";
3464 namespaced_token_len = STRLITERALLEN("lxc.cgroup.");
3465 list = &c->cgroup;
3466 } else {
3467 return -EINVAL;
3468 }
3469
3470 if (strcmp(key, global_token) == 0)
3471 all = true;
3472 else if (strncmp(key, namespaced_token, namespaced_token_len) == 0)
3473 k += namespaced_token_len;
3474 else
3475 return -EINVAL;
3476
3477 lxc_list_for_each_safe (it, list, next) {
3478 struct lxc_cgroup *cg = it->elem;
3479
3480 if (!all && strcmp(cg->subsystem, k) != 0)
3481 continue;
3482
3483 lxc_list_del(it);
3484 free(cg->subsystem);
3485 free(cg->value);
3486 free(cg);
3487 free(it);
3488 }
3489
3490 return 0;
3491}
3492
3493static void lxc_clear_devices(struct lxc_conf *conf)
3494{
3495 struct lxc_list *list = &conf->devices;
3496 struct lxc_list *it, *next;
3497
3498 lxc_list_for_each_safe(it, list, next) {
3499 lxc_list_del(it);
3500 free(it);
3501 }
3502}
3503
3504int lxc_clear_limits(struct lxc_conf *c, const char *key)
3505{
3506 struct lxc_list *it, *next;
3507 const char *k = NULL;
3508 bool all = false;
3509
3510 if (strcmp(key, "lxc.limit") == 0 || strcmp(key, "lxc.prlimit") == 0)
3511 all = true;
3512 else if (strncmp(key, "lxc.limit.", STRLITERALLEN("lxc.limit.")) == 0)
3513 k = key + STRLITERALLEN("lxc.limit.");
3514 else if (strncmp(key, "lxc.prlimit.", STRLITERALLEN("lxc.prlimit.")) == 0)
3515 k = key + STRLITERALLEN("lxc.prlimit.");
3516 else
3517 return -1;
3518
3519 lxc_list_for_each_safe (it, &c->limits, next) {
3520 struct lxc_limit *lim = it->elem;
3521
3522 if (!all && strcmp(lim->resource, k) != 0)
3523 continue;
3524
3525 lxc_list_del(it);
3526 free(lim->resource);
3527 free(lim);
3528 free(it);
3529 }
3530
3531 return 0;
3532}
3533
3534int lxc_clear_sysctls(struct lxc_conf *c, const char *key)
3535{
3536 struct lxc_list *it, *next;
3537 const char *k = NULL;
3538 bool all = false;
3539
3540 if (strcmp(key, "lxc.sysctl") == 0)
3541 all = true;
3542 else if (strncmp(key, "lxc.sysctl.", STRLITERALLEN("lxc.sysctl.")) == 0)
3543 k = key + STRLITERALLEN("lxc.sysctl.");
3544 else
3545 return -1;
3546
3547 lxc_list_for_each_safe (it, &c->sysctls, next) {
3548 struct lxc_sysctl *elem = it->elem;
3549
3550 if (!all && strcmp(elem->key, k) != 0)
3551 continue;
3552
3553 lxc_list_del(it);
3554 free(elem->key);
3555 free(elem->value);
3556 free(elem);
3557 free(it);
3558 }
3559
3560 return 0;
3561}
3562
3563int lxc_clear_procs(struct lxc_conf *c, const char *key)
3564{
3565 struct lxc_list *it, *next;
3566 const char *k = NULL;
3567 bool all = false;
3568
3569 if (strcmp(key, "lxc.proc") == 0)
3570 all = true;
3571 else if (strncmp(key, "lxc.proc.", STRLITERALLEN("lxc.proc.")) == 0)
3572 k = key + STRLITERALLEN("lxc.proc.");
3573 else
3574 return -1;
3575
3576 lxc_list_for_each_safe (it, &c->procs, next) {
3577 struct lxc_proc *proc = it->elem;
3578
3579 if (!all && strcmp(proc->filename, k) != 0)
3580 continue;
3581
3582 lxc_list_del(it);
3583 free(proc->filename);
3584 free(proc->value);
3585 free(proc);
3586 free(it);
3587 }
3588
3589 return 0;
3590}
3591
3592int lxc_clear_groups(struct lxc_conf *c)
3593{
3594 struct lxc_list *it, *next;
3595
3596 lxc_list_for_each_safe (it, &c->groups, next) {
3597 lxc_list_del(it);
3598 free(it->elem);
3599 free(it);
3600 }
3601
3602 return 0;
3603}
3604
3605int lxc_clear_environment(struct lxc_conf *c)
3606{
3607 struct lxc_list *it, *next;
3608
3609 lxc_list_for_each_safe (it, &c->environment, next) {
3610 lxc_list_del(it);
3611 free(it->elem);
3612 free(it);
3613 }
3614
3615 return 0;
3616}
3617
3618int lxc_clear_mount_entries(struct lxc_conf *c)
3619{
3620 struct lxc_list *it, *next;
3621
3622 lxc_list_for_each_safe (it, &c->mount_list, next) {
3623 lxc_list_del(it);
3624 free(it->elem);
3625 free(it);
3626 }
3627
3628 return 0;
3629}
3630
3631int lxc_clear_automounts(struct lxc_conf *c)
3632{
3633 c->auto_mounts = 0;
3634 return 0;
3635}
3636
3637int lxc_clear_hooks(struct lxc_conf *c, const char *key)
3638{
3639 int i;
3640 struct lxc_list *it, *next;
3641 const char *k = NULL;
3642 bool all = false, done = false;
3643
3644 if (strcmp(key, "lxc.hook") == 0)
3645 all = true;
3646 else if (strncmp(key, "lxc.hook.", STRLITERALLEN("lxc.hook.")) == 0)
3647 k = key + STRLITERALLEN("lxc.hook.");
3648 else
3649 return -1;
3650
3651 for (i = 0; i < NUM_LXC_HOOKS; i++) {
3652 if (all || strcmp(k, lxchook_names[i]) == 0) {
3653 lxc_list_for_each_safe (it, &c->hooks[i], next) {
3654 lxc_list_del(it);
3655 free(it->elem);
3656 free(it);
3657 }
3658
3659 done = true;
3660 }
3661 }
3662
3663 if (!done)
3664 return log_error(-1, "Invalid hook key: %s", key);
3665
3666 return 0;
3667}
3668
3669static inline void lxc_clear_aliens(struct lxc_conf *conf)
3670{
3671 struct lxc_list *it, *next;
3672
3673 lxc_list_for_each_safe (it, &conf->aliens, next) {
3674 lxc_list_del(it);
3675 free(it->elem);
3676 free(it);
3677 }
3678}
3679
3680void lxc_clear_includes(struct lxc_conf *conf)
3681{
3682 struct lxc_list *it, *next;
3683
3684 lxc_list_for_each_safe (it, &conf->includes, next) {
3685 lxc_list_del(it);
3686 free(it->elem);
3687 free(it);
3688 }
3689}
3690
3691int lxc_clear_apparmor_raw(struct lxc_conf *c)
3692{
3693 struct lxc_list *it, *next;
3694
3695 lxc_list_for_each_safe (it, &c->lsm_aa_raw, next) {
3696 lxc_list_del(it);
3697 free(it->elem);
3698 free(it);
3699 }
3700
3701 return 0;
3702}
3703
3704void lxc_conf_free(struct lxc_conf *conf)
3705{
3706 if (!conf)
3707 return;
3708
3709 if (current_config == conf)
3710 current_config = NULL;
3711 lxc_terminal_conf_free(&conf->console);
3712 free(conf->rootfs.mount);
3713 free(conf->rootfs.bdev_type);
3714 free(conf->rootfs.options);
3715 free(conf->rootfs.path);
3716 free(conf->rootfs.data);
3717 free(conf->logfile);
3718 if (conf->logfd != -1)
3719 close(conf->logfd);
3720 free(conf->utsname);
3721 free(conf->ttys.dir);
3722 free(conf->ttys.tty_names);
3723 free(conf->fstab);
3724 free(conf->rcfile);
3725 free(conf->execute_cmd);
3726 free(conf->init_cmd);
3727 free(conf->init_cwd);
3728 free(conf->unexpanded_config);
3729 free(conf->syslog);
3730 lxc_free_networks(&conf->network);
3731 free(conf->lsm_aa_profile);
3732 free(conf->lsm_aa_profile_computed);
3733 free(conf->lsm_se_context);
3734 lxc_seccomp_free(&conf->seccomp);
3735 lxc_clear_config_caps(conf);
3736 lxc_clear_config_keepcaps(conf);
3737 lxc_clear_cgroups(conf, "lxc.cgroup", CGROUP_SUPER_MAGIC);
3738 lxc_clear_cgroups(conf, "lxc.cgroup2", CGROUP2_SUPER_MAGIC);
3739 lxc_clear_devices(conf);
3740 lxc_clear_cgroup2_devices(conf);
3741 lxc_clear_hooks(conf, "lxc.hook");
3742 lxc_clear_mount_entries(conf);
3743 lxc_clear_idmaps(conf);
3744 lxc_clear_groups(conf);
3745 lxc_clear_includes(conf);
3746 lxc_clear_aliens(conf);
3747 lxc_clear_environment(conf);
3748 lxc_clear_limits(conf, "lxc.prlimit");
3749 lxc_clear_sysctls(conf, "lxc.sysctl");
3750 lxc_clear_procs(conf, "lxc.proc");
3751 lxc_clear_apparmor_raw(conf);
3752 lxc_clear_namespace(conf);
3753 free(conf->cgroup_meta.dir);
3754 free(conf->cgroup_meta.monitor_dir);
3755 free(conf->cgroup_meta.container_dir);
3756 free(conf->cgroup_meta.namespace_dir);
3757 free(conf->cgroup_meta.controllers);
3758 free(conf->shmount.path_host);
3759 free(conf->shmount.path_cont);
3760 free(conf);
3761}
3762
3763struct userns_fn_data {
3764 int (*fn)(void *);
3765 const char *fn_name;
3766 void *arg;
3767 int p[2];
3768};
3769
3770static int run_userns_fn(void *data)
3771{
3772 struct userns_fn_data *d = data;
3773 int ret;
3774 char c;
3775
3776 close_prot_errno_disarm(d->p[1]);
3777
3778 /*
3779 * Wait for parent to finish establishing a new mapping in the user
3780 * namespace we are executing in.
3781 */
3782 ret = lxc_read_nointr(d->p[0], &c, 1);
3783 close_prot_errno_disarm(d->p[0]);
3784 if (ret != 1)
3785 return -1;
3786
3787 if (d->fn_name)
3788 TRACE("Calling function \"%s\"", d->fn_name);
3789
3790 /* Call function to run. */
3791 return d->fn(d->arg);
3792}
3793
3794static struct id_map *mapped_nsid_add(const struct lxc_conf *conf, unsigned id,
3795 enum idtype idtype)
3796{
3797 const struct id_map *map;
3798 struct id_map *retmap;
3799
3800 map = find_mapped_nsid_entry(conf, id, idtype);
3801 if (!map)
3802 return NULL;
3803
3804 retmap = malloc(sizeof(*retmap));
3805 if (!retmap)
3806 return NULL;
3807
3808 memcpy(retmap, map, sizeof(*retmap));
3809 return retmap;
3810}
3811
3812static struct id_map *find_mapped_hostid_entry(const struct lxc_conf *conf,
3813 unsigned id, enum idtype idtype)
3814{
3815 struct id_map *map;
3816 struct lxc_list *it;
3817 struct id_map *retmap = NULL;
3818
3819 lxc_list_for_each (it, &conf->id_map) {
3820 map = it->elem;
3821 if (map->idtype != idtype)
3822 continue;
3823
3824 if (id >= map->hostid && id < map->hostid + map->range) {
3825 retmap = map;
3826 break;
3827 }
3828 }
3829
3830 return retmap;
3831}
3832
3833/* Allocate a new {g,u}id mapping for the given {g,u}id. Re-use an already
3834 * existing one or establish a new one.
3835 */
3836static struct id_map *mapped_hostid_add(const struct lxc_conf *conf, uid_t id,
3837 enum idtype type)
3838{
3839 __do_free struct id_map *entry = NULL;
3840 int hostid_mapped;
3841 struct id_map *tmp = NULL;
3842
3843 entry = malloc(sizeof(*entry));
3844 if (!entry)
3845 return NULL;
3846
3847 /* Reuse existing mapping. */
3848 tmp = find_mapped_hostid_entry(conf, id, type);
3849 if (tmp) {
3850 memcpy(entry, tmp, sizeof(*entry));
3851 } else {
3852 /* Find new mapping. */
3853 hostid_mapped = find_unmapped_nsid(conf, type);
3854 if (hostid_mapped < 0)
3855 return log_debug(NULL, "Failed to find free mapping for id %d", id);
3856
3857 entry->idtype = type;
3858 entry->nsid = hostid_mapped;
3859 entry->hostid = (unsigned long)id;
3860 entry->range = 1;
3861 }
3862
3863 return move_ptr(entry);
3864}
3865
3866static struct lxc_list *get_minimal_idmap(const struct lxc_conf *conf,
3867 uid_t *resuid, gid_t *resgid)
3868{
3869 __do_free struct id_map *container_root_uid = NULL,
3870 *container_root_gid = NULL,
3871 *host_uid_map = NULL, *host_gid_map = NULL;
3872 __do_free struct lxc_list *idmap = NULL;
3873 uid_t euid, egid;
3874 uid_t nsuid = (conf->root_nsuid_map != NULL) ? 0 : conf->init_uid;
3875 gid_t nsgid = (conf->root_nsgid_map != NULL) ? 0 : conf->init_gid;
3876 struct lxc_list *tmplist = NULL;
3877
3878 /* Find container root mappings. */
3879 container_root_uid = mapped_nsid_add(conf, nsuid, ID_TYPE_UID);
3880 if (!container_root_uid)
3881 return log_debug(NULL, "Failed to find mapping for namespace uid %d", 0);
3882 euid = geteuid();
3883 if (euid >= container_root_uid->hostid &&
3884 euid < (container_root_uid->hostid + container_root_uid->range))
3885 host_uid_map = move_ptr(container_root_uid);
3886
3887 container_root_gid = mapped_nsid_add(conf, nsgid, ID_TYPE_GID);
3888 if (!container_root_gid)
3889 return log_debug(NULL, "Failed to find mapping for namespace gid %d", 0);
3890 egid = getegid();
3891 if (egid >= container_root_gid->hostid &&
3892 egid < (container_root_gid->hostid + container_root_gid->range))
3893 host_gid_map = move_ptr(container_root_gid);
3894
3895 /* Check whether the {g,u}id of the user has a mapping. */
3896 if (!host_uid_map)
3897 host_uid_map = mapped_hostid_add(conf, euid, ID_TYPE_UID);
3898 if (!host_uid_map)
3899 return log_debug(NULL, "Failed to find mapping for uid %d", euid);
3900
3901 if (!host_gid_map)
3902 host_gid_map = mapped_hostid_add(conf, egid, ID_TYPE_GID);
3903 if (!host_gid_map)
3904 return log_debug(NULL, "Failed to find mapping for gid %d", egid);
3905
3906 /* Allocate new {g,u}id map list. */
3907 idmap = malloc(sizeof(*idmap));
3908 if (!idmap)
3909 return NULL;
3910 lxc_list_init(idmap);
3911
3912 /* Add container root to the map. */
3913 tmplist = malloc(sizeof(*tmplist));
3914 if (!tmplist)
3915 return NULL;
3916 /* idmap will now keep track of that memory. */
3917 lxc_list_add_elem(tmplist, move_ptr(host_uid_map));
3918 lxc_list_add_tail(idmap, tmplist);
3919
3920 if (container_root_uid) {
3921 /* Add container root to the map. */
3922 tmplist = malloc(sizeof(*tmplist));
3923 if (!tmplist)
3924 return NULL;
3925 /* idmap will now keep track of that memory. */
3926 lxc_list_add_elem(tmplist, move_ptr(container_root_uid));
3927 lxc_list_add_tail(idmap, tmplist);
3928 }
3929
3930 tmplist = malloc(sizeof(*tmplist));
3931 if (!tmplist)
3932 return NULL;
3933 /* idmap will now keep track of that memory. */
3934 lxc_list_add_elem(tmplist, move_ptr(host_gid_map));
3935 lxc_list_add_tail(idmap, tmplist);
3936
3937 if (container_root_gid) {
3938 tmplist = malloc(sizeof(*tmplist));
3939 if (!tmplist)
3940 return NULL;
3941 /* idmap will now keep track of that memory. */
3942 lxc_list_add_elem(tmplist, move_ptr(container_root_gid));
3943 lxc_list_add_tail(idmap, tmplist);
3944 }
3945
3946 TRACE("Allocated minimal idmapping for ns uid %d and ns gid %d", nsuid, nsgid);
3947
3948 if (resuid)
3949 *resuid = nsuid;
3950 if (resgid)
3951 *resgid = nsgid;
3952 return move_ptr(idmap);
3953}
3954
3955/*
3956 * Run a function in a new user namespace.
3957 * The caller's euid/egid will be mapped if it is not already.
3958 * Afaict, userns_exec_1() is only used to operate based on privileges for the
3959 * user's own {g,u}id on the host and for the container root's unmapped {g,u}id.
3960 * This means we require only to establish a mapping from:
3961 * - the container root {g,u}id as seen from the host > user's host {g,u}id
3962 * - the container root -> some sub{g,u}id
3963 * The former we add, if the user did not specify a mapping. The latter we
3964 * retrieve from the container's configured {g,u}id mappings as it must have been
3965 * there to start the container in the first place.
3966 */
3967int userns_exec_1(const struct lxc_conf *conf, int (*fn)(void *), void *data,
3968 const char *fn_name)
3969{
3970 call_cleaner(lxc_free_idmap) struct lxc_list *idmap = NULL;
3971 int ret = -1, status = -1;
3972 char c = '1';
3973 struct userns_fn_data d = {
3974 .arg = data,
3975 .fn = fn,
3976 .fn_name = fn_name,
3977 };
3978 pid_t pid;
3979 int pipe_fds[2];
3980
3981 if (!conf)
3982 return -EINVAL;
3983
3984 idmap = get_minimal_idmap(conf, NULL, NULL);
3985 if (!idmap)
3986 return ret_errno(ENOENT);
3987
3988 ret = pipe2(pipe_fds, O_CLOEXEC);
3989 if (ret < 0)
3990 return -errno;
3991
3992 d.p[0] = pipe_fds[0];
3993 d.p[1] = pipe_fds[1];
3994
3995 /* Clone child in new user namespace. */
3996 pid = lxc_raw_clone_cb(run_userns_fn, &d, CLONE_NEWUSER, NULL);
3997 if (pid < 0) {
3998 ERROR("Failed to clone process in new user namespace");
3999 goto on_error;
4000 }
4001
4002 close_prot_errno_disarm(pipe_fds[0]);
4003
4004 if (lxc_log_get_level() == LXC_LOG_LEVEL_TRACE ||
4005 conf->loglevel == LXC_LOG_LEVEL_TRACE) {
4006 struct id_map *map;
4007 struct lxc_list *it;
4008
4009 lxc_list_for_each(it, idmap) {
4010 map = it->elem;
4011 TRACE("Establishing %cid mapping for \"%d\" in new user namespace: nsuid %lu - hostid %lu - range %lu",
4012 (map->idtype == ID_TYPE_UID) ? 'u' : 'g', pid, map->nsid, map->hostid, map->range);
4013 }
4014 }
4015
4016 /* Set up {g,u}id mapping for user namespace of child process. */
4017 ret = lxc_map_ids(idmap, pid);
4018 if (ret < 0) {
4019 ERROR("Error setting up {g,u}id mappings for child process \"%d\"", pid);
4020 goto on_error;
4021 }
4022
4023 /* Tell child to proceed. */
4024 if (lxc_write_nointr(pipe_fds[1], &c, 1) != 1) {
4025 SYSERROR("Failed telling child process \"%d\" to proceed", pid);
4026 goto on_error;
4027 }
4028
4029on_error:
4030 close_prot_errno_disarm(pipe_fds[0]);
4031 close_prot_errno_disarm(pipe_fds[1]);
4032
4033 /* Wait for child to finish. */
4034 if (pid > 0)
4035 status = wait_for_pid(pid);
4036
4037 if (status < 0)
4038 ret = -1;
4039
4040 return ret;
4041}
4042
4043int userns_exec_minimal(const struct lxc_conf *conf,
4044 int (*fn_parent)(void *), void *fn_parent_data,
4045 int (*fn_child)(void *), void *fn_child_data)
4046{
4047 call_cleaner(lxc_free_idmap) struct lxc_list *idmap = NULL;
4048 uid_t resuid = LXC_INVALID_UID;
4049 gid_t resgid = LXC_INVALID_GID;
4050 char c = '1';
4051 ssize_t ret;
4052 pid_t pid;
4053 int sock_fds[2];
4054
4055 if (!conf || !fn_child)
4056 return ret_errno(EINVAL);
4057
4058 idmap = get_minimal_idmap(conf, &resuid, &resgid);
4059 if (!idmap)
4060 return ret_errno(ENOENT);
4061
4062 ret = socketpair(PF_LOCAL, SOCK_STREAM | SOCK_CLOEXEC, 0, sock_fds);
4063 if (ret < 0)
4064 return -errno;
4065
4066 pid = fork();
4067 if (pid < 0) {
4068 SYSERROR("Failed to create new process");
4069 goto on_error;
4070 }
4071
4072 if (pid == 0) {
4073 close_prot_errno_disarm(sock_fds[1]);
4074
4075 ret = unshare(CLONE_NEWUSER);
4076 if (ret < 0) {
4077 SYSERROR("Failed to unshare new user namespace");
4078 _exit(EXIT_FAILURE);
4079 }
4080
4081 ret = lxc_write_nointr(sock_fds[0], &c, 1);
4082 if (ret != 1)
4083 _exit(EXIT_FAILURE);
4084
4085 ret = lxc_read_nointr(sock_fds[0], &c, 1);
4086 if (ret != 1)
4087 _exit(EXIT_FAILURE);
4088
4089 close_prot_errno_disarm(sock_fds[0]);
4090
4091 if (!lxc_setgroups(0, NULL) && errno != EPERM)
4092 _exit(EXIT_FAILURE);
4093
4094 ret = setresgid(resgid, resgid, resgid);
4095 if (ret < 0) {
4096 SYSERROR("Failed to setresgid(%d, %d, %d)",
4097 resgid, resgid, resgid);
4098 _exit(EXIT_FAILURE);
4099 }
4100
4101 ret = setresuid(resuid, resuid, resuid);
4102 if (ret < 0) {
4103 SYSERROR("Failed to setresuid(%d, %d, %d)",
4104 resuid, resuid, resuid);
4105 _exit(EXIT_FAILURE);
4106 }
4107
4108 ret = fn_child(fn_child_data);
4109 if (ret) {
4110 SYSERROR("Running function in new user namespace failed");
4111 _exit(EXIT_FAILURE);
4112 }
4113
4114 _exit(EXIT_SUCCESS);
4115 }
4116
4117 close_prot_errno_disarm(sock_fds[0]);
4118
4119 if (lxc_log_get_level() == LXC_LOG_LEVEL_TRACE ||
4120 conf->loglevel == LXC_LOG_LEVEL_TRACE) {
4121 struct id_map *map;
4122 struct lxc_list *it;
4123
4124 lxc_list_for_each(it, idmap) {
4125 map = it->elem;
4126 TRACE("Establishing %cid mapping for \"%d\" in new user namespace: nsuid %lu - hostid %lu - range %lu",
4127 (map->idtype == ID_TYPE_UID) ? 'u' : 'g', pid, map->nsid, map->hostid, map->range);
4128 }
4129 }
4130
4131 ret = lxc_read_nointr(sock_fds[1], &c, 1);
4132 if (ret != 1) {
4133 SYSERROR("Failed waiting for child process %d\" to tell us to proceed", pid);
4134 goto on_error;
4135 }
4136
4137 /* Set up {g,u}id mapping for user namespace of child process. */
4138 ret = lxc_map_ids(idmap, pid);
4139 if (ret < 0) {
4140 ERROR("Error setting up {g,u}id mappings for child process \"%d\"", pid);
4141 goto on_error;
4142 }
4143
4144 /* Tell child to proceed. */
4145 ret = lxc_write_nointr(sock_fds[1], &c, 1);
4146 if (ret != 1) {
4147 SYSERROR("Failed telling child process \"%d\" to proceed", pid);
4148 goto on_error;
4149 }
4150
4151 if (fn_parent && fn_parent(fn_parent_data)) {
4152 SYSERROR("Running parent function failed");
4153 _exit(EXIT_FAILURE);
4154 }
4155
4156on_error:
4157 close_prot_errno_disarm(sock_fds[0]);
4158 close_prot_errno_disarm(sock_fds[1]);
4159
4160 /* Wait for child to finish. */
4161 if (pid < 0)
4162 return -1;
4163
4164 return wait_for_pid(pid);
4165}
4166
4167int userns_exec_full(struct lxc_conf *conf, int (*fn)(void *), void *data,
4168 const char *fn_name)
4169{
4170 pid_t pid;
4171 uid_t euid, egid;
4172 int p[2];
4173 struct id_map *map;
4174 struct lxc_list *cur;
4175 struct userns_fn_data d;
4176 int ret = -1;
4177 char c = '1';
4178 struct lxc_list *idmap = NULL, *tmplist = NULL;
4179 struct id_map *container_root_uid = NULL, *container_root_gid = NULL,
4180 *host_uid_map = NULL, *host_gid_map = NULL;
4181
4182 if (!conf)
4183 return -EINVAL;
4184
4185 ret = pipe2(p, O_CLOEXEC);
4186 if (ret < 0) {
4187 SYSERROR("opening pipe");
4188 return -1;
4189 }
4190 d.fn = fn;
4191 d.fn_name = fn_name;
4192 d.arg = data;
4193 d.p[0] = p[0];
4194 d.p[1] = p[1];
4195
4196 /* Clone child in new user namespace. */
4197 pid = lxc_clone(run_userns_fn, &d, CLONE_NEWUSER, NULL);
4198 if (pid < 0) {
4199 ERROR("Failed to clone process in new user namespace");
4200 goto on_error;
4201 }
4202
4203 close(p[0]);
4204 p[0] = -1;
4205
4206 euid = geteuid();
4207 egid = getegid();
4208
4209 /* Allocate new {g,u}id map list. */
4210 idmap = malloc(sizeof(*idmap));
4211 if (!idmap)
4212 goto on_error;
4213 lxc_list_init(idmap);
4214
4215 /* Find container root. */
4216 lxc_list_for_each (cur, &conf->id_map) {
4217 struct id_map *tmpmap;
4218
4219 tmplist = malloc(sizeof(*tmplist));
4220 if (!tmplist)
4221 goto on_error;
4222
4223 tmpmap = malloc(sizeof(*tmpmap));
4224 if (!tmpmap) {
4225 free(tmplist);
4226 goto on_error;
4227 }
4228
4229 memset(tmpmap, 0, sizeof(*tmpmap));
4230 memcpy(tmpmap, cur->elem, sizeof(*tmpmap));
4231 tmplist->elem = tmpmap;
4232
4233 lxc_list_add_tail(idmap, tmplist);
4234
4235 map = cur->elem;
4236
4237 if (map->idtype == ID_TYPE_UID)
4238 if (euid >= map->hostid && euid < map->hostid + map->range)
4239 host_uid_map = map;
4240
4241 if (map->idtype == ID_TYPE_GID)
4242 if (egid >= map->hostid && egid < map->hostid + map->range)
4243 host_gid_map = map;
4244
4245 if (map->nsid != 0)
4246 continue;
4247
4248 if (map->idtype == ID_TYPE_UID)
4249 if (container_root_uid == NULL)
4250 container_root_uid = map;
4251
4252 if (map->idtype == ID_TYPE_GID)
4253 if (container_root_gid == NULL)
4254 container_root_gid = map;
4255 }
4256
4257 if (!container_root_uid || !container_root_gid) {
4258 ERROR("No mapping for container root found");
4259 goto on_error;
4260 }
4261
4262 /* Check whether the {g,u}id of the user has a mapping. */
4263 if (!host_uid_map)
4264 host_uid_map = mapped_hostid_add(conf, euid, ID_TYPE_UID);
4265 else
4266 host_uid_map = container_root_uid;
4267
4268 if (!host_gid_map)
4269 host_gid_map = mapped_hostid_add(conf, egid, ID_TYPE_GID);
4270 else
4271 host_gid_map = container_root_gid;
4272
4273 if (!host_uid_map) {
4274 DEBUG("Failed to find mapping for uid %d", euid);
4275 goto on_error;
4276 }
4277
4278 if (!host_gid_map) {
4279 DEBUG("Failed to find mapping for gid %d", egid);
4280 goto on_error;
4281 }
4282
4283 if (host_uid_map && (host_uid_map != container_root_uid)) {
4284 /* Add container root to the map. */
4285 tmplist = malloc(sizeof(*tmplist));
4286 if (!tmplist)
4287 goto on_error;
4288 lxc_list_add_elem(tmplist, host_uid_map);
4289 lxc_list_add_tail(idmap, tmplist);
4290 }
4291 /* idmap will now keep track of that memory. */
4292 host_uid_map = NULL;
4293
4294 if (host_gid_map && (host_gid_map != container_root_gid)) {
4295 tmplist = malloc(sizeof(*tmplist));
4296 if (!tmplist)
4297 goto on_error;
4298 lxc_list_add_elem(tmplist, host_gid_map);
4299 lxc_list_add_tail(idmap, tmplist);
4300 }
4301 /* idmap will now keep track of that memory. */
4302 host_gid_map = NULL;
4303
4304 if (lxc_log_get_level() == LXC_LOG_LEVEL_TRACE ||
4305 conf->loglevel == LXC_LOG_LEVEL_TRACE) {
4306 lxc_list_for_each (cur, idmap) {
4307 map = cur->elem;
4308 TRACE("establishing %cid mapping for \"%d\" in new "
4309 "user namespace: nsuid %lu - hostid %lu - range "
4310 "%lu",
4311 (map->idtype == ID_TYPE_UID) ? 'u' : 'g', pid,
4312 map->nsid, map->hostid, map->range);
4313 }
4314 }
4315
4316 /* Set up {g,u}id mapping for user namespace of child process. */
4317 ret = lxc_map_ids(idmap, pid);
4318 if (ret < 0) {
4319 ERROR("error setting up {g,u}id mappings for child process \"%d\"", pid);
4320 goto on_error;
4321 }
4322
4323 /* Tell child to proceed. */
4324 if (lxc_write_nointr(p[1], &c, 1) != 1) {
4325 SYSERROR("Failed telling child process \"%d\" to proceed", pid);
4326 goto on_error;
4327 }
4328
4329on_error:
4330 if (p[0] != -1)
4331 close(p[0]);
4332 close(p[1]);
4333
4334 /* Wait for child to finish. */
4335 if (pid > 0)
4336 ret = wait_for_pid(pid);
4337
4338 if (idmap) {
4339 lxc_free_idmap(idmap);
4340 free(idmap);
4341 }
4342
4343 if (host_uid_map && (host_uid_map != container_root_uid))
4344 free(host_uid_map);
4345 if (host_gid_map && (host_gid_map != container_root_gid))
4346 free(host_gid_map);
4347
4348 return ret;
4349}
4350
4351static int add_idmap_entry(struct lxc_list *idmap, enum idtype idtype,
4352 unsigned long nsid, unsigned long hostid,
4353 unsigned long range)
4354{
4355 __do_free struct id_map *new_idmap = NULL;
4356 __do_free struct lxc_list *new_list = NULL;
4357
4358 new_idmap = zalloc(sizeof(*new_idmap));
4359 if (!new_idmap)
4360 return ret_errno(ENOMEM);
4361
4362 new_idmap->idtype = idtype;
4363 new_idmap->hostid = hostid;
4364 new_idmap->nsid = nsid;
4365 new_idmap->range = range;
4366
4367 new_list = zalloc(sizeof(*new_list));
4368 if (!new_list)
4369 return ret_errno(ENOMEM);
4370
4371 new_list->elem = move_ptr(new_idmap);
4372 lxc_list_add_tail(idmap, move_ptr(new_list));
4373
4374 INFO("Adding id map: type %c nsid %lu hostid %lu range %lu",
4375 idtype == ID_TYPE_UID ? 'u' : 'g', nsid, hostid, range);
4376 return 0;
4377}
4378
4379int userns_exec_mapped_root(const char *path, int path_fd,
4380 const struct lxc_conf *conf)
4381{
4382 call_cleaner(lxc_free_idmap) struct lxc_list *idmap = NULL;
4383 __do_close int fd = -EBADF;
4384 int target_fd = -EBADF;
4385 char c = '1';
4386 ssize_t ret;
4387 pid_t pid;
4388 int sock_fds[2];
4389 uid_t container_host_uid, hostuid;
4390 gid_t container_host_gid, hostgid;
4391 struct stat st;
4392
4393 if (!conf || (!path && path_fd < 0))
4394 return ret_errno(EINVAL);
4395
4396 if (!path)
4397 path = "(null)";
4398
4399 container_host_uid = get_mapped_rootid(conf, ID_TYPE_UID);
4400 if (!uid_valid(container_host_uid))
4401 return log_error(-1, "No uid mapping for container root");
4402
4403 container_host_gid = get_mapped_rootid(conf, ID_TYPE_GID);
4404 if (!gid_valid(container_host_gid))
4405 return log_error(-1, "No gid mapping for container root");
4406
4407 if (path_fd < 0) {
4408 fd = open(path, O_CLOEXEC | O_NOCTTY);
4409 if (fd < 0)
4410 return log_error_errno(-errno, errno, "Failed to open \"%s\"", path);
4411 target_fd = fd;
4412 } else {
4413 target_fd = path_fd;
4414 }
4415
4416 hostuid = geteuid();
4417 /* We are root so chown directly. */
4418 if (hostuid == 0) {
4419 ret = fchown(target_fd, container_host_uid, container_host_gid);
4420 if (ret)
4421 return log_error_errno(-errno, errno,
4422 "Failed to fchown(%d(%s), %d, %d)",
4423 target_fd, path, container_host_uid,
4424 container_host_gid);
4425 return log_trace(0, "Chowned %d(%s) to uid %d and %d", target_fd, path,
4426 container_host_uid, container_host_gid);
4427 }
4428
4429 /* The container's root host id matches */
4430 if (container_host_uid == hostuid)
4431 return log_info(0, "Container root id is mapped to our uid");
4432
4433 /* Get the current ids of our target. */
4434 ret = fstat(target_fd, &st);
4435 if (ret)
4436 return log_error_errno(-errno, errno, "Failed to stat \"%s\"", path);
4437
4438 hostgid = getegid();
4439 if (st.st_uid == hostuid && mapped_hostid(st.st_gid, conf, ID_TYPE_GID) < 0) {
4440 ret = fchown(target_fd, -1, hostgid);
4441 if (ret)
4442 return log_error_errno(-errno, errno,
4443 "Failed to fchown(%d(%s), -1, %d)",
4444 target_fd, path, hostgid);
4445 TRACE("Chowned %d(%s) to -1:%d", target_fd, path, hostgid);
4446 }
4447
4448 idmap = malloc(sizeof(*idmap));
4449 if (!idmap)
4450 return -ENOMEM;
4451 lxc_list_init(idmap);
4452
4453 /* "u:0:rootuid:1" */
4454 ret = add_idmap_entry(idmap, ID_TYPE_UID, 0, container_host_uid, 1);
4455 if (ret < 0)
4456 return log_error_errno(ret, -ret, "Failed to add idmap entry");
4457
4458 /* "u:hostuid:hostuid:1" */
4459 ret = add_idmap_entry(idmap, ID_TYPE_UID, hostuid, hostuid, 1);
4460 if (ret < 0)
4461 return log_error_errno(ret, -ret, "Failed to add idmap entry");
4462
4463 /* "g:0:rootgid:1" */
4464 ret = add_idmap_entry(idmap, ID_TYPE_GID, 0, container_host_gid, 1);
4465 if (ret < 0)
4466 return log_error_errno(ret, -ret, "Failed to add idmap entry");
4467
4468 /* "g:hostgid:hostgid:1" */
4469 ret = add_idmap_entry(idmap, ID_TYPE_GID, hostgid, hostgid, 1);
4470 if (ret < 0)
4471 return log_error_errno(ret, -ret, "Failed to add idmap entry");
4472
4473 if (hostgid != st.st_gid) {
4474 /* "g:pathgid:rootgid+pathgid:1" */
4475 ret = add_idmap_entry(idmap, ID_TYPE_GID, st.st_gid,
4476 container_host_gid + (gid_t)st.st_gid, 1);
4477 if (ret < 0)
4478 return log_error_errno(ret, -ret, "Failed to add idmap entry");
4479 }
4480
4481 ret = socketpair(PF_LOCAL, SOCK_STREAM | SOCK_CLOEXEC, 0, sock_fds);
4482 if (ret < 0)
4483 return -errno;
4484
4485 pid = fork();
4486 if (pid < 0) {
4487 SYSERROR("Failed to create new process");
4488 goto on_error;
4489 }
4490
4491 if (pid == 0) {
4492 close_prot_errno_disarm(sock_fds[1]);
4493
4494 ret = unshare(CLONE_NEWUSER);
4495 if (ret < 0) {
4496 SYSERROR("Failed to unshare new user namespace");
4497 _exit(EXIT_FAILURE);
4498 }
4499
4500 ret = lxc_write_nointr(sock_fds[0], &c, 1);
4501 if (ret != 1)
4502 _exit(EXIT_FAILURE);
4503
4504 ret = lxc_read_nointr(sock_fds[0], &c, 1);
4505 if (ret != 1)
4506 _exit(EXIT_FAILURE);
4507
4508 close_prot_errno_disarm(sock_fds[0]);
4509
4510 if (!lxc_switch_uid_gid(0, 0))
4511 _exit(EXIT_FAILURE);
4512
4513 if (!lxc_setgroups(0, NULL))
4514 _exit(EXIT_FAILURE);
4515
4516 ret = fchown(target_fd, 0, st.st_gid);
4517 if (ret) {
4518 SYSERROR("Failed to chown %d(%s) to -1:%d", target_fd, path, st.st_gid);
4519 _exit(EXIT_FAILURE);
4520 }
4521
4522 TRACE("Chowned %d(%s) to 0:%d", target_fd, path, st.st_gid);
4523 _exit(EXIT_SUCCESS);
4524 }
4525
4526 close_prot_errno_disarm(sock_fds[0]);
4527
4528 if (lxc_log_get_level() == LXC_LOG_LEVEL_TRACE ||
4529 conf->loglevel == LXC_LOG_LEVEL_TRACE) {
4530 struct id_map *map;
4531 struct lxc_list *it;
4532
4533 lxc_list_for_each(it, idmap) {
4534 map = it->elem;
4535 TRACE("Establishing %cid mapping for \"%d\" in new user namespace: nsuid %lu - hostid %lu - range %lu",
4536 (map->idtype == ID_TYPE_UID) ? 'u' : 'g', pid, map->nsid, map->hostid, map->range);
4537 }
4538 }
4539
4540 ret = lxc_read_nointr(sock_fds[1], &c, 1);
4541 if (ret != 1) {
4542 SYSERROR("Failed waiting for child process %d\" to tell us to proceed", pid);
4543 goto on_error;
4544 }
4545
4546 /* Set up {g,u}id mapping for user namespace of child process. */
4547 ret = lxc_map_ids(idmap, pid);
4548 if (ret < 0) {
4549 ERROR("Error setting up {g,u}id mappings for child process \"%d\"", pid);
4550 goto on_error;
4551 }
4552
4553 /* Tell child to proceed. */
4554 ret = lxc_write_nointr(sock_fds[1], &c, 1);
4555 if (ret != 1) {
4556 SYSERROR("Failed telling child process \"%d\" to proceed", pid);
4557 goto on_error;
4558 }
4559
4560on_error:
4561 close_prot_errno_disarm(sock_fds[0]);
4562 close_prot_errno_disarm(sock_fds[1]);
4563
4564 /* Wait for child to finish. */
4565 if (pid < 0)
4566 return -1;
4567
4568 return wait_for_pid(pid);
4569}
4570
4571/* not thread-safe, do not use from api without first forking */
4572static char *getuname(void)
4573{
4574 __do_free char *buf = NULL;
4575 struct passwd pwent;
4576 struct passwd *pwentp = NULL;
4577 size_t bufsize;
4578 int ret;
4579
4580 bufsize = sysconf(_SC_GETPW_R_SIZE_MAX);
4581 if (bufsize == -1)
4582 bufsize = 1024;
4583
4584 buf = malloc(bufsize);
4585 if (!buf)
4586 return NULL;
4587
4588 ret = getpwuid_r(geteuid(), &pwent, buf, bufsize, &pwentp);
4589 if (!pwentp) {
4590 if (ret == 0)
4591 WARN("Could not find matched password record.");
4592
4593 return log_error(NULL, "Failed to get password record - %u", geteuid());
4594 }
4595
4596 return strdup(pwent.pw_name);
4597}
4598
4599/* not thread-safe, do not use from api without first forking */
4600static char *getgname(void)
4601{
4602 __do_free char *buf = NULL;
4603 struct group grent;
4604 struct group *grentp = NULL;
4605 size_t bufsize;
4606 int ret;
4607
4608 bufsize = sysconf(_SC_GETGR_R_SIZE_MAX);
4609 if (bufsize == -1)
4610 bufsize = 1024;
4611
4612 buf = malloc(bufsize);
4613 if (!buf)
4614 return NULL;
4615
4616 ret = getgrgid_r(getegid(), &grent, buf, bufsize, &grentp);
4617 if (!grentp) {
4618 if (ret == 0)
4619 WARN("Could not find matched group record");
4620
4621 return log_error(NULL, "Failed to get group record - %u", getegid());
4622 }
4623
4624 return strdup(grent.gr_name);
4625}
4626
4627/* not thread-safe, do not use from api without first forking */
4628void suggest_default_idmap(void)
4629{
4630 __do_free char *gname = NULL, *line = NULL, *uname = NULL;
4631 __do_fclose FILE *subuid_f = NULL, *subgid_f = NULL;
4632 unsigned int uid = 0, urange = 0, gid = 0, grange = 0;
4633 size_t len = 0;
4634
4635 uname = getuname();
4636 if (!uname)
4637 return;
4638
4639 gname = getgname();
4640 if (!gname)
4641 return;
4642
4643 subuid_f = fopen(subuidfile, "re");
4644 if (!subuid_f) {
4645 ERROR("Your system is not configured with subuids");
4646 return;
4647 }
4648
4649 while (getline(&line, &len, subuid_f) != -1) {
4650 char *p, *p2;
4651 size_t no_newline = 0;
4652
4653 p = strchr(line, ':');
4654 if (*line == '#')
4655 continue;
4656 if (!p)
4657 continue;
4658 *p = '\0';
4659 p++;
4660
4661 if (strcmp(line, uname))
4662 continue;
4663
4664 p2 = strchr(p, ':');
4665 if (!p2)
4666 continue;
4667 *p2 = '\0';
4668 p2++;
4669 if (!*p2)
4670 continue;
4671 no_newline = strcspn(p2, "\n");
4672 p2[no_newline] = '\0';
4673
4674 if (lxc_safe_uint(p, &uid) < 0)
4675 WARN("Could not parse UID");
4676 if (lxc_safe_uint(p2, &urange) < 0)
4677 WARN("Could not parse UID range");
4678 }
4679
4680 subgid_f = fopen(subgidfile, "re");
4681 if (!subgid_f) {
4682 ERROR("Your system is not configured with subgids");
4683 return;
4684 }
4685
4686 while (getline(&line, &len, subgid_f) != -1) {
4687 char *p, *p2;
4688 size_t no_newline = 0;
4689
4690 p = strchr(line, ':');
4691 if (*line == '#')
4692 continue;
4693 if (!p)
4694 continue;
4695 *p = '\0';
4696 p++;
4697
4698 if (strcmp(line, uname))
4699 continue;
4700
4701 p2 = strchr(p, ':');
4702 if (!p2)
4703 continue;
4704 *p2 = '\0';
4705 p2++;
4706 if (!*p2)
4707 continue;
4708 no_newline = strcspn(p2, "\n");
4709 p2[no_newline] = '\0';
4710
4711 if (lxc_safe_uint(p, &gid) < 0)
4712 WARN("Could not parse GID");
4713 if (lxc_safe_uint(p2, &grange) < 0)
4714 WARN("Could not parse GID range");
4715 }
4716
4717 if (!urange || !grange) {
4718 ERROR("You do not have subuids or subgids allocated");
4719 ERROR("Unprivileged containers require subuids and subgids");
4720 return;
4721 }
4722
4723 ERROR("You must either run as root, or define uid mappings");
4724 ERROR("To pass uid mappings to lxc-create, you could create");
4725 ERROR("~/.config/lxc/default.conf:");
4726 ERROR("lxc.include = %s", LXC_DEFAULT_CONFIG);
4727 ERROR("lxc.idmap = u 0 %u %u", uid, urange);
4728 ERROR("lxc.idmap = g 0 %u %u", gid, grange);
4729}
4730
4731static void free_cgroup_settings(struct lxc_list *result)
4732{
4733 struct lxc_list *iterator, *next;
4734
4735 lxc_list_for_each_safe (iterator, result, next) {
4736 lxc_list_del(iterator);
4737 free_disarm(iterator);
4738 }
4739 free_disarm(result);
4740}
4741
4742/* Return the list of cgroup_settings sorted according to the following rules
4743 * 1. Put memory.limit_in_bytes before memory.memsw.limit_in_bytes
4744 */
4745struct lxc_list *sort_cgroup_settings(struct lxc_list *cgroup_settings)
4746{
4747 struct lxc_list *result;
4748 struct lxc_cgroup *cg = NULL;
4749 struct lxc_list *it = NULL, *item = NULL, *memsw_limit = NULL;
4750
4751 result = malloc(sizeof(*result));
4752 if (!result)
4753 return NULL;
4754 lxc_list_init(result);
4755
4756 /* Iterate over the cgroup settings and copy them to the output list. */
4757 lxc_list_for_each (it, cgroup_settings) {
4758 item = malloc(sizeof(*item));
4759 if (!item) {
4760 free_cgroup_settings(result);
4761 return NULL;
4762 }
4763
4764 item->elem = it->elem;
4765 cg = it->elem;
4766 if (strcmp(cg->subsystem, "memory.memsw.limit_in_bytes") == 0) {
4767 /* Store the memsw_limit location */
4768 memsw_limit = item;
4769 } else if (strcmp(cg->subsystem, "memory.limit_in_bytes") == 0 &&
4770 memsw_limit != NULL) {
4771 /* lxc.cgroup.memory.memsw.limit_in_bytes is found
4772 * before lxc.cgroup.memory.limit_in_bytes, swap these
4773 * two items */
4774 item->elem = memsw_limit->elem;
4775 memsw_limit->elem = it->elem;
4776 }
4777 lxc_list_add_tail(result, item);
4778 }
4779
4780 return result;
4781}
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