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1 | /* | |
2 | * lxc: linux Container library | |
3 | * | |
4 | * (C) Copyright IBM Corp. 2007, 2008 | |
5 | * | |
6 | * Authors: | |
7 | * Daniel Lezcano <daniel.lezcano at free.fr> | |
8 | * | |
9 | * This library is free software; you can redistribute it and/or | |
10 | * modify it under the terms of the GNU Lesser General Public | |
11 | * License as published by the Free Software Foundation; either | |
12 | * version 2.1 of the License, or (at your option) any later version. | |
13 | * | |
14 | * This library is distributed in the hope that it will be useful, | |
15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
17 | * Lesser General Public License for more details. | |
18 | * | |
19 | * You should have received a copy of the GNU Lesser General Public | |
20 | * License along with this library; if not, write to the Free Software | |
21 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
22 | */ | |
23 | ||
24 | #ifndef _GNU_SOURCE | |
25 | #define _GNU_SOURCE 1 | |
26 | #endif | |
27 | #include <arpa/inet.h> | |
28 | #include <dirent.h> | |
29 | #include <errno.h> | |
30 | #include <fcntl.h> | |
31 | #include <grp.h> | |
32 | #include <inttypes.h> | |
33 | #include <libgen.h> | |
34 | #include <linux/loop.h> | |
35 | #include <net/if.h> | |
36 | #include <netinet/in.h> | |
37 | #include <pwd.h> | |
38 | #include <stdarg.h> | |
39 | #include <stdio.h> | |
40 | #include <stdlib.h> | |
41 | #include <string.h> | |
42 | #include <sys/mman.h> | |
43 | #include <sys/mount.h> | |
44 | #include <sys/param.h> | |
45 | #include <sys/prctl.h> | |
46 | #include <sys/sendfile.h> | |
47 | #include <sys/socket.h> | |
48 | #include <sys/stat.h> | |
49 | #include <sys/syscall.h> | |
50 | #include <sys/sysmacros.h> | |
51 | #include <sys/types.h> | |
52 | #include <sys/utsname.h> | |
53 | #include <sys/wait.h> | |
54 | #include <time.h> | |
55 | #include <unistd.h> | |
56 | ||
57 | #include "af_unix.h" | |
58 | #include "caps.h" | |
59 | #include "cgroup.h" | |
60 | #include "conf.h" | |
61 | #include "config.h" | |
62 | #include "confile.h" | |
63 | #include "confile_utils.h" | |
64 | #include "error.h" | |
65 | #include "log.h" | |
66 | #include "lsm/lsm.h" | |
67 | #include "lxclock.h" | |
68 | #include "lxcseccomp.h" | |
69 | #include "macro.h" | |
70 | #include "namespace.h" | |
71 | #include "network.h" | |
72 | #include "parse.h" | |
73 | #include "raw_syscalls.h" | |
74 | #include "ringbuf.h" | |
75 | #include "start.h" | |
76 | #include "storage.h" | |
77 | #include "storage/overlay.h" | |
78 | #include "syscall_wrappers.h" | |
79 | #include "terminal.h" | |
80 | #include "utils.h" | |
81 | ||
82 | #ifdef MAJOR_IN_MKDEV | |
83 | #include <sys/mkdev.h> | |
84 | #endif | |
85 | ||
86 | #ifdef HAVE_STATVFS | |
87 | #include <sys/statvfs.h> | |
88 | #endif | |
89 | ||
90 | #if HAVE_PTY_H | |
91 | #include <pty.h> | |
92 | #else | |
93 | #include <../include/openpty.h> | |
94 | #endif | |
95 | ||
96 | #if HAVE_LIBCAP | |
97 | #include <sys/capability.h> | |
98 | #endif | |
99 | ||
100 | #if HAVE_SYS_PERSONALITY_H | |
101 | #include <sys/personality.h> | |
102 | #endif | |
103 | ||
104 | #ifndef HAVE_STRLCAT | |
105 | #include "include/strlcat.h" | |
106 | #endif | |
107 | ||
108 | #if IS_BIONIC | |
109 | #include <../include/lxcmntent.h> | |
110 | #else | |
111 | #include <mntent.h> | |
112 | #endif | |
113 | ||
114 | #if !defined(HAVE_PRLIMIT) && defined(HAVE_PRLIMIT64) | |
115 | #include <../include/prlimit.h> | |
116 | #endif | |
117 | ||
118 | lxc_log_define(conf, lxc); | |
119 | ||
120 | /* The lxc_conf of the container currently being worked on in an API call. | |
121 | * This is used in the error calls. | |
122 | */ | |
123 | #ifdef HAVE_TLS | |
124 | thread_local struct lxc_conf *current_config; | |
125 | #else | |
126 | struct lxc_conf *current_config; | |
127 | #endif | |
128 | ||
129 | char *lxchook_names[NUM_LXC_HOOKS] = { | |
130 | "pre-start", | |
131 | "pre-mount", | |
132 | "mount", | |
133 | "autodev", | |
134 | "start", | |
135 | "stop", | |
136 | "post-stop", | |
137 | "clone", | |
138 | "destroy", | |
139 | "start-host" | |
140 | }; | |
141 | ||
142 | struct mount_opt { | |
143 | char *name; | |
144 | int clear; | |
145 | int flag; | |
146 | }; | |
147 | ||
148 | struct caps_opt { | |
149 | char *name; | |
150 | int value; | |
151 | }; | |
152 | ||
153 | struct limit_opt { | |
154 | char *name; | |
155 | int value; | |
156 | }; | |
157 | ||
158 | static struct mount_opt mount_opt[] = { | |
159 | { "async", 1, MS_SYNCHRONOUS }, | |
160 | { "atime", 1, MS_NOATIME }, | |
161 | { "bind", 0, MS_BIND }, | |
162 | { "defaults", 0, 0 }, | |
163 | { "dev", 1, MS_NODEV }, | |
164 | { "diratime", 1, MS_NODIRATIME }, | |
165 | { "dirsync", 0, MS_DIRSYNC }, | |
166 | { "exec", 1, MS_NOEXEC }, | |
167 | { "lazytime", 0, MS_LAZYTIME }, | |
168 | { "mand", 0, MS_MANDLOCK }, | |
169 | { "noatime", 0, MS_NOATIME }, | |
170 | { "nodev", 0, MS_NODEV }, | |
171 | { "nodiratime", 0, MS_NODIRATIME }, | |
172 | { "noexec", 0, MS_NOEXEC }, | |
173 | { "nomand", 1, MS_MANDLOCK }, | |
174 | { "norelatime", 1, MS_RELATIME }, | |
175 | { "nostrictatime", 1, MS_STRICTATIME }, | |
176 | { "nosuid", 0, MS_NOSUID }, | |
177 | { "rbind", 0, MS_BIND|MS_REC }, | |
178 | { "relatime", 0, MS_RELATIME }, | |
179 | { "remount", 0, MS_REMOUNT }, | |
180 | { "ro", 0, MS_RDONLY }, | |
181 | { "rw", 1, MS_RDONLY }, | |
182 | { "strictatime", 0, MS_STRICTATIME }, | |
183 | { "suid", 1, MS_NOSUID }, | |
184 | { "sync", 0, MS_SYNCHRONOUS }, | |
185 | { NULL, 0, 0 }, | |
186 | }; | |
187 | ||
188 | static struct mount_opt propagation_opt[] = { | |
189 | { "private", 0, MS_PRIVATE }, | |
190 | { "shared", 0, MS_SHARED }, | |
191 | { "slave", 0, MS_SLAVE }, | |
192 | { "unbindable", 0, MS_UNBINDABLE }, | |
193 | { "rprivate", 0, MS_PRIVATE|MS_REC }, | |
194 | { "rshared", 0, MS_SHARED|MS_REC }, | |
195 | { "rslave", 0, MS_SLAVE|MS_REC }, | |
196 | { "runbindable", 0, MS_UNBINDABLE|MS_REC }, | |
197 | { NULL, 0, 0 }, | |
198 | }; | |
199 | ||
200 | static struct caps_opt caps_opt[] = { | |
201 | #if HAVE_LIBCAP | |
202 | { "chown", CAP_CHOWN }, | |
203 | { "dac_override", CAP_DAC_OVERRIDE }, | |
204 | { "dac_read_search", CAP_DAC_READ_SEARCH }, | |
205 | { "fowner", CAP_FOWNER }, | |
206 | { "fsetid", CAP_FSETID }, | |
207 | { "kill", CAP_KILL }, | |
208 | { "setgid", CAP_SETGID }, | |
209 | { "setuid", CAP_SETUID }, | |
210 | { "setpcap", CAP_SETPCAP }, | |
211 | { "linux_immutable", CAP_LINUX_IMMUTABLE }, | |
212 | { "net_bind_service", CAP_NET_BIND_SERVICE }, | |
213 | { "net_broadcast", CAP_NET_BROADCAST }, | |
214 | { "net_admin", CAP_NET_ADMIN }, | |
215 | { "net_raw", CAP_NET_RAW }, | |
216 | { "ipc_lock", CAP_IPC_LOCK }, | |
217 | { "ipc_owner", CAP_IPC_OWNER }, | |
218 | { "sys_module", CAP_SYS_MODULE }, | |
219 | { "sys_rawio", CAP_SYS_RAWIO }, | |
220 | { "sys_chroot", CAP_SYS_CHROOT }, | |
221 | { "sys_ptrace", CAP_SYS_PTRACE }, | |
222 | { "sys_pacct", CAP_SYS_PACCT }, | |
223 | { "sys_admin", CAP_SYS_ADMIN }, | |
224 | { "sys_boot", CAP_SYS_BOOT }, | |
225 | { "sys_nice", CAP_SYS_NICE }, | |
226 | { "sys_resource", CAP_SYS_RESOURCE }, | |
227 | { "sys_time", CAP_SYS_TIME }, | |
228 | { "sys_tty_config", CAP_SYS_TTY_CONFIG }, | |
229 | { "mknod", CAP_MKNOD }, | |
230 | { "lease", CAP_LEASE }, | |
231 | #ifdef CAP_AUDIT_READ | |
232 | { "audit_read", CAP_AUDIT_READ }, | |
233 | #endif | |
234 | #ifdef CAP_AUDIT_WRITE | |
235 | { "audit_write", CAP_AUDIT_WRITE }, | |
236 | #endif | |
237 | #ifdef CAP_AUDIT_CONTROL | |
238 | { "audit_control", CAP_AUDIT_CONTROL }, | |
239 | #endif | |
240 | { "setfcap", CAP_SETFCAP }, | |
241 | { "mac_override", CAP_MAC_OVERRIDE }, | |
242 | { "mac_admin", CAP_MAC_ADMIN }, | |
243 | #ifdef CAP_SYSLOG | |
244 | { "syslog", CAP_SYSLOG }, | |
245 | #endif | |
246 | #ifdef CAP_WAKE_ALARM | |
247 | { "wake_alarm", CAP_WAKE_ALARM }, | |
248 | #endif | |
249 | #ifdef CAP_BLOCK_SUSPEND | |
250 | { "block_suspend", CAP_BLOCK_SUSPEND }, | |
251 | #endif | |
252 | #endif | |
253 | }; | |
254 | ||
255 | static struct limit_opt limit_opt[] = { | |
256 | #ifdef RLIMIT_AS | |
257 | { "as", RLIMIT_AS }, | |
258 | #endif | |
259 | #ifdef RLIMIT_CORE | |
260 | { "core", RLIMIT_CORE }, | |
261 | #endif | |
262 | #ifdef RLIMIT_CPU | |
263 | { "cpu", RLIMIT_CPU }, | |
264 | #endif | |
265 | #ifdef RLIMIT_DATA | |
266 | { "data", RLIMIT_DATA }, | |
267 | #endif | |
268 | #ifdef RLIMIT_FSIZE | |
269 | { "fsize", RLIMIT_FSIZE }, | |
270 | #endif | |
271 | #ifdef RLIMIT_LOCKS | |
272 | { "locks", RLIMIT_LOCKS }, | |
273 | #endif | |
274 | #ifdef RLIMIT_MEMLOCK | |
275 | { "memlock", RLIMIT_MEMLOCK }, | |
276 | #endif | |
277 | #ifdef RLIMIT_MSGQUEUE | |
278 | { "msgqueue", RLIMIT_MSGQUEUE }, | |
279 | #endif | |
280 | #ifdef RLIMIT_NICE | |
281 | { "nice", RLIMIT_NICE }, | |
282 | #endif | |
283 | #ifdef RLIMIT_NOFILE | |
284 | { "nofile", RLIMIT_NOFILE }, | |
285 | #endif | |
286 | #ifdef RLIMIT_NPROC | |
287 | { "nproc", RLIMIT_NPROC }, | |
288 | #endif | |
289 | #ifdef RLIMIT_RSS | |
290 | { "rss", RLIMIT_RSS }, | |
291 | #endif | |
292 | #ifdef RLIMIT_RTPRIO | |
293 | { "rtprio", RLIMIT_RTPRIO }, | |
294 | #endif | |
295 | #ifdef RLIMIT_RTTIME | |
296 | { "rttime", RLIMIT_RTTIME }, | |
297 | #endif | |
298 | #ifdef RLIMIT_SIGPENDING | |
299 | { "sigpending", RLIMIT_SIGPENDING }, | |
300 | #endif | |
301 | #ifdef RLIMIT_STACK | |
302 | { "stack", RLIMIT_STACK }, | |
303 | #endif | |
304 | }; | |
305 | ||
306 | static int run_buffer(char *buffer) | |
307 | { | |
308 | int ret; | |
309 | char *output; | |
310 | struct lxc_popen_FILE *f; | |
311 | ||
312 | f = lxc_popen(buffer); | |
313 | if (!f) { | |
314 | SYSERROR("Failed to popen() %s", buffer); | |
315 | return -1; | |
316 | } | |
317 | ||
318 | output = malloc(LXC_LOG_BUFFER_SIZE); | |
319 | if (!output) { | |
320 | ERROR("Failed to allocate memory for %s", buffer); | |
321 | lxc_pclose(f); | |
322 | return -1; | |
323 | } | |
324 | ||
325 | while (fgets(output, LXC_LOG_BUFFER_SIZE, f->f)) | |
326 | DEBUG("Script %s with output: %s", buffer, output); | |
327 | ||
328 | free(output); | |
329 | ||
330 | ret = lxc_pclose(f); | |
331 | if (ret == -1) { | |
332 | SYSERROR("Script exited with error"); | |
333 | return -1; | |
334 | } else if (WIFEXITED(ret) && WEXITSTATUS(ret) != 0) { | |
335 | ERROR("Script exited with status %d", WEXITSTATUS(ret)); | |
336 | return -1; | |
337 | } else if (WIFSIGNALED(ret)) { | |
338 | ERROR("Script terminated by signal %d", WTERMSIG(ret)); | |
339 | return -1; | |
340 | } | |
341 | ||
342 | return 0; | |
343 | } | |
344 | ||
345 | int run_script_argv(const char *name, unsigned int hook_version, | |
346 | const char *section, const char *script, | |
347 | const char *hookname, char **argv) | |
348 | { | |
349 | int buf_pos, i, ret; | |
350 | char *buffer; | |
351 | int fret = -1; | |
352 | size_t size = 0; | |
353 | ||
354 | if (hook_version == 0) | |
355 | INFO("Executing script \"%s\" for container \"%s\", config " | |
356 | "section \"%s\"", script, name, section); | |
357 | else | |
358 | INFO("Executing script \"%s\" for container \"%s\"", script, name); | |
359 | ||
360 | for (i = 0; argv && argv[i]; i++) | |
361 | size += strlen(argv[i]) + 1; | |
362 | ||
363 | size += STRLITERALLEN("exec"); | |
364 | size++; | |
365 | size += strlen(script); | |
366 | size++; | |
367 | ||
368 | if (size > INT_MAX) | |
369 | return -EFBIG; | |
370 | ||
371 | if (hook_version == 0) { | |
372 | size += strlen(hookname); | |
373 | size++; | |
374 | ||
375 | size += strlen(name); | |
376 | size++; | |
377 | ||
378 | size += strlen(section); | |
379 | size++; | |
380 | ||
381 | if (size > INT_MAX) | |
382 | return -EFBIG; | |
383 | } | |
384 | ||
385 | buffer = malloc(size); | |
386 | if (!buffer) | |
387 | return -ENOMEM; | |
388 | ||
389 | if (hook_version == 0) | |
390 | buf_pos = snprintf(buffer, size, "exec %s %s %s %s", script, name, section, hookname); | |
391 | else | |
392 | buf_pos = snprintf(buffer, size, "exec %s", script); | |
393 | if (buf_pos < 0 || (size_t)buf_pos >= size) { | |
394 | ERROR("Failed to create command line for script \"%s\"", script); | |
395 | goto on_error; | |
396 | } | |
397 | ||
398 | if (hook_version == 1) { | |
399 | ret = setenv("LXC_HOOK_TYPE", hookname, 1); | |
400 | if (ret < 0) { | |
401 | SYSERROR("Failed to set environment variable: " | |
402 | "LXC_HOOK_TYPE=%s", hookname); | |
403 | goto on_error; | |
404 | } | |
405 | TRACE("Set environment variable: LXC_HOOK_TYPE=%s", hookname); | |
406 | ||
407 | ret = setenv("LXC_HOOK_SECTION", section, 1); | |
408 | if (ret < 0) { | |
409 | SYSERROR("Failed to set environment variable: " | |
410 | "LXC_HOOK_SECTION=%s", section); | |
411 | goto on_error; | |
412 | } | |
413 | TRACE("Set environment variable: LXC_HOOK_SECTION=%s", section); | |
414 | ||
415 | if (strcmp(section, "net") == 0) { | |
416 | char *parent; | |
417 | ||
418 | if (!argv || !argv[0]) | |
419 | goto on_error; | |
420 | ||
421 | ret = setenv("LXC_NET_TYPE", argv[0], 1); | |
422 | if (ret < 0) { | |
423 | SYSERROR("Failed to set environment variable: " | |
424 | "LXC_NET_TYPE=%s", argv[0]); | |
425 | goto on_error; | |
426 | } | |
427 | TRACE("Set environment variable: LXC_NET_TYPE=%s", argv[0]); | |
428 | ||
429 | parent = argv[1] ? argv[1] : ""; | |
430 | ||
431 | if (strcmp(argv[0], "macvlan") == 0) { | |
432 | ret = setenv("LXC_NET_PARENT", parent, 1); | |
433 | if (ret < 0) { | |
434 | SYSERROR("Failed to set environment " | |
435 | "variable: LXC_NET_PARENT=%s", parent); | |
436 | goto on_error; | |
437 | } | |
438 | TRACE("Set environment variable: LXC_NET_PARENT=%s", parent); | |
439 | } else if (strcmp(argv[0], "phys") == 0) { | |
440 | ret = setenv("LXC_NET_PARENT", parent, 1); | |
441 | if (ret < 0) { | |
442 | SYSERROR("Failed to set environment " | |
443 | "variable: LXC_NET_PARENT=%s", parent); | |
444 | goto on_error; | |
445 | } | |
446 | TRACE("Set environment variable: LXC_NET_PARENT=%s", parent); | |
447 | } else if (strcmp(argv[0], "veth") == 0) { | |
448 | char *peer = argv[2] ? argv[2] : ""; | |
449 | ||
450 | ret = setenv("LXC_NET_PEER", peer, 1); | |
451 | if (ret < 0) { | |
452 | SYSERROR("Failed to set environment " | |
453 | "variable: LXC_NET_PEER=%s", peer); | |
454 | goto on_error; | |
455 | } | |
456 | TRACE("Set environment variable: LXC_NET_PEER=%s", peer); | |
457 | ||
458 | ret = setenv("LXC_NET_PARENT", parent, 1); | |
459 | if (ret < 0) { | |
460 | SYSERROR("Failed to set environment " | |
461 | "variable: LXC_NET_PARENT=%s", parent); | |
462 | goto on_error; | |
463 | } | |
464 | TRACE("Set environment variable: LXC_NET_PARENT=%s", parent); | |
465 | } | |
466 | } | |
467 | } | |
468 | ||
469 | for (i = 0; argv && argv[i]; i++) { | |
470 | size_t len = size - buf_pos; | |
471 | ||
472 | ret = snprintf(buffer + buf_pos, len, " %s", argv[i]); | |
473 | if (ret < 0 || (size_t)ret >= len) { | |
474 | ERROR("Failed to create command line for script \"%s\"", script); | |
475 | goto on_error; | |
476 | } | |
477 | buf_pos += ret; | |
478 | } | |
479 | ||
480 | fret = run_buffer(buffer); | |
481 | ||
482 | on_error: | |
483 | free(buffer); | |
484 | return fret; | |
485 | } | |
486 | ||
487 | int run_script(const char *name, const char *section, const char *script, ...) | |
488 | { | |
489 | int ret; | |
490 | char *buffer, *p; | |
491 | va_list ap; | |
492 | size_t size = 0; | |
493 | ||
494 | INFO("Executing script \"%s\" for container \"%s\", config section \"%s\"", | |
495 | script, name, section); | |
496 | ||
497 | va_start(ap, script); | |
498 | while ((p = va_arg(ap, char *))) | |
499 | size += strlen(p) + 1; | |
500 | va_end(ap); | |
501 | ||
502 | size += STRLITERALLEN("exec"); | |
503 | size += strlen(script); | |
504 | size += strlen(name); | |
505 | size += strlen(section); | |
506 | size += 4; | |
507 | ||
508 | if (size > INT_MAX) | |
509 | return -1; | |
510 | ||
511 | buffer = alloca(size); | |
512 | ret = snprintf(buffer, size, "exec %s %s %s", script, name, section); | |
513 | if (ret < 0 || ret >= size) | |
514 | return -1; | |
515 | ||
516 | va_start(ap, script); | |
517 | while ((p = va_arg(ap, char *))) { | |
518 | int len = size - ret; | |
519 | int rc; | |
520 | rc = snprintf(buffer + ret, len, " %s", p); | |
521 | if (rc < 0 || rc >= len) { | |
522 | va_end(ap); | |
523 | return -1; | |
524 | } | |
525 | ret += rc; | |
526 | } | |
527 | va_end(ap); | |
528 | ||
529 | return run_buffer(buffer); | |
530 | } | |
531 | ||
532 | /* pin_rootfs | |
533 | * if rootfs is a directory, then open ${rootfs}/.lxc-keep for writing for | |
534 | * the duration of the container run, to prevent the container from marking | |
535 | * the underlying fs readonly on shutdown. unlink the file immediately so | |
536 | * no name pollution is happens. | |
537 | * don't unlink on NFS to avoid random named stale handles. | |
538 | * return -1 on error. | |
539 | * return -2 if nothing needed to be pinned. | |
540 | * return an open fd (>=0) if we pinned it. | |
541 | */ | |
542 | int pin_rootfs(const char *rootfs) | |
543 | { | |
544 | int fd, ret; | |
545 | char absrootfspin[PATH_MAX]; | |
546 | char *absrootfs; | |
547 | struct stat s; | |
548 | struct statfs sfs; | |
549 | ||
550 | if (rootfs == NULL || strlen(rootfs) == 0) | |
551 | return -2; | |
552 | ||
553 | absrootfs = realpath(rootfs, NULL); | |
554 | if (!absrootfs) | |
555 | return -2; | |
556 | ||
557 | ret = stat(absrootfs, &s); | |
558 | if (ret < 0) { | |
559 | free(absrootfs); | |
560 | return -1; | |
561 | } | |
562 | ||
563 | if (!S_ISDIR(s.st_mode)) { | |
564 | free(absrootfs); | |
565 | return -2; | |
566 | } | |
567 | ||
568 | ret = snprintf(absrootfspin, PATH_MAX, "%s/.lxc-keep", absrootfs); | |
569 | free(absrootfs); | |
570 | if (ret < 0 || ret >= PATH_MAX) | |
571 | return -1; | |
572 | ||
573 | fd = open(absrootfspin, O_CREAT | O_RDWR, S_IWUSR | S_IRUSR); | |
574 | if (fd < 0) | |
575 | return fd; | |
576 | ||
577 | ret = fstatfs (fd, &sfs); | |
578 | if (ret < 0) | |
579 | return fd; | |
580 | ||
581 | if (sfs.f_type == NFS_SUPER_MAGIC) { | |
582 | DEBUG("Rootfs on NFS, not unlinking pin file \"%s\"", absrootfspin); | |
583 | return fd; | |
584 | } | |
585 | ||
586 | (void)unlink(absrootfspin); | |
587 | ||
588 | return fd; | |
589 | } | |
590 | ||
591 | /* If we are asking to remount something, make sure that any NOEXEC etc are | |
592 | * honored. | |
593 | */ | |
594 | unsigned long add_required_remount_flags(const char *s, const char *d, | |
595 | unsigned long flags) | |
596 | { | |
597 | #ifdef HAVE_STATVFS | |
598 | int ret; | |
599 | struct statvfs sb; | |
600 | unsigned long required_flags = 0; | |
601 | ||
602 | if (!s) | |
603 | s = d; | |
604 | ||
605 | if (!s) | |
606 | return flags; | |
607 | ||
608 | ret = statvfs(s, &sb); | |
609 | if (ret < 0) | |
610 | return flags; | |
611 | ||
612 | if (flags & MS_REMOUNT) { | |
613 | if (sb.f_flag & MS_NOSUID) | |
614 | required_flags |= MS_NOSUID; | |
615 | if (sb.f_flag & MS_NODEV) | |
616 | required_flags |= MS_NODEV; | |
617 | if (sb.f_flag & MS_RDONLY) | |
618 | required_flags |= MS_RDONLY; | |
619 | if (sb.f_flag & MS_NOEXEC) | |
620 | required_flags |= MS_NOEXEC; | |
621 | } | |
622 | ||
623 | if (sb.f_flag & MS_NOATIME) | |
624 | required_flags |= MS_NOATIME; | |
625 | if (sb.f_flag & MS_NODIRATIME) | |
626 | required_flags |= MS_NODIRATIME; | |
627 | if (sb.f_flag & MS_LAZYTIME) | |
628 | required_flags |= MS_LAZYTIME; | |
629 | if (sb.f_flag & MS_RELATIME) | |
630 | required_flags |= MS_RELATIME; | |
631 | if (sb.f_flag & MS_STRICTATIME) | |
632 | required_flags |= MS_STRICTATIME; | |
633 | ||
634 | return flags | required_flags; | |
635 | #else | |
636 | return flags; | |
637 | #endif | |
638 | } | |
639 | ||
640 | static int add_shmount_to_list(struct lxc_conf *conf) | |
641 | { | |
642 | char new_mount[PATH_MAX]; | |
643 | /* Offset for the leading '/' since the path_cont | |
644 | * is absolute inside the container. | |
645 | */ | |
646 | int offset = 1, ret = -1; | |
647 | ||
648 | ret = snprintf(new_mount, sizeof(new_mount), | |
649 | "%s %s none bind,create=dir 0 0", conf->shmount.path_host, | |
650 | conf->shmount.path_cont + offset); | |
651 | if (ret < 0 || (size_t)ret >= sizeof(new_mount)) | |
652 | return -1; | |
653 | ||
654 | return add_elem_to_mount_list(new_mount, conf); | |
655 | } | |
656 | ||
657 | static int lxc_mount_auto_mounts(struct lxc_conf *conf, int flags, struct lxc_handler *handler) | |
658 | { | |
659 | int i, r; | |
660 | static struct { | |
661 | int match_mask; | |
662 | int match_flag; | |
663 | const char *source; | |
664 | const char *destination; | |
665 | const char *fstype; | |
666 | unsigned long flags; | |
667 | const char *options; | |
668 | } default_mounts[] = { | |
669 | /* Read-only bind-mounting... In older kernels, doing that | |
670 | * required to do one MS_BIND mount and then | |
671 | * MS_REMOUNT|MS_RDONLY the same one. According to mount(2) | |
672 | * manpage, MS_BIND honors MS_RDONLY from kernel 2.6.26 | |
673 | * onwards. However, this apparently does not work on kernel | |
674 | * 3.8. Unfortunately, on that very same kernel, doing the same | |
675 | * trick as above doesn't seem to work either, there one needs | |
676 | * to ALSO specify MS_BIND for the remount, otherwise the | |
677 | * entire fs is remounted read-only or the mount fails because | |
678 | * it's busy... MS_REMOUNT|MS_BIND|MS_RDONLY seems to work for | |
679 | * kernels as low as 2.6.32... | |
680 | */ | |
681 | { LXC_AUTO_PROC_MASK, LXC_AUTO_PROC_MIXED, "proc", "%r/proc", "proc", MS_NODEV|MS_NOEXEC|MS_NOSUID, NULL }, | |
682 | /* proc/tty is used as a temporary placeholder for proc/sys/net which we'll move back in a few steps */ | |
683 | { LXC_AUTO_PROC_MASK, LXC_AUTO_PROC_MIXED, "%r/proc/sys/net", "%r/proc/tty", NULL, MS_BIND, NULL }, | |
684 | { LXC_AUTO_PROC_MASK, LXC_AUTO_PROC_MIXED, "%r/proc/sys", "%r/proc/sys", NULL, MS_BIND, NULL }, | |
685 | { LXC_AUTO_PROC_MASK, LXC_AUTO_PROC_MIXED, NULL, "%r/proc/sys", NULL, MS_REMOUNT|MS_BIND|MS_RDONLY, NULL }, | |
686 | { LXC_AUTO_PROC_MASK, LXC_AUTO_PROC_MIXED, "%r/proc/tty", "%r/proc/sys/net", NULL, MS_MOVE, NULL }, | |
687 | { LXC_AUTO_PROC_MASK, LXC_AUTO_PROC_MIXED, "%r/proc/sysrq-trigger", "%r/proc/sysrq-trigger", NULL, MS_BIND, NULL }, | |
688 | { LXC_AUTO_PROC_MASK, LXC_AUTO_PROC_MIXED, NULL, "%r/proc/sysrq-trigger", NULL, MS_REMOUNT|MS_BIND|MS_RDONLY, NULL }, | |
689 | { LXC_AUTO_PROC_MASK, LXC_AUTO_PROC_RW, "proc", "%r/proc", "proc", MS_NODEV|MS_NOEXEC|MS_NOSUID, NULL }, | |
690 | { LXC_AUTO_SYS_MASK, LXC_AUTO_SYS_RW, "sysfs", "%r/sys", "sysfs", 0, NULL }, | |
691 | { LXC_AUTO_SYS_MASK, LXC_AUTO_SYS_RO, "sysfs", "%r/sys", "sysfs", MS_RDONLY, NULL }, | |
692 | { LXC_AUTO_SYS_MASK, LXC_AUTO_SYS_MIXED, "sysfs", "%r/sys", "sysfs", MS_NODEV|MS_NOEXEC|MS_NOSUID, NULL }, | |
693 | { LXC_AUTO_SYS_MASK, LXC_AUTO_SYS_MIXED, NULL, "%r/sys", NULL, MS_REMOUNT|MS_BIND|MS_RDONLY, NULL }, | |
694 | { LXC_AUTO_SYS_MASK, LXC_AUTO_SYS_MIXED, "sysfs", "%r/sys/devices/virtual/net", "sysfs", 0, NULL }, | |
695 | { 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 }, | |
696 | { 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 }, | |
697 | { 0, 0, NULL, NULL, NULL, 0, NULL } | |
698 | }; | |
699 | ||
700 | for (i = 0; default_mounts[i].match_mask; i++) { | |
701 | int saved_errno; | |
702 | unsigned long mflags; | |
703 | char *destination = NULL; | |
704 | char *source = NULL; | |
705 | if ((flags & default_mounts[i].match_mask) != default_mounts[i].match_flag) | |
706 | continue; | |
707 | ||
708 | if (default_mounts[i].source) { | |
709 | /* will act like strdup if %r is not present */ | |
710 | source = lxc_string_replace("%r", conf->rootfs.path ? conf->rootfs.mount : "", default_mounts[i].source); | |
711 | if (!source) | |
712 | return -1; | |
713 | } | |
714 | ||
715 | if (!default_mounts[i].destination) { | |
716 | ERROR("BUG: auto mounts destination %d was NULL", i); | |
717 | free(source); | |
718 | return -1; | |
719 | } | |
720 | ||
721 | /* will act like strdup if %r is not present */ | |
722 | destination = lxc_string_replace("%r", conf->rootfs.path ? conf->rootfs.mount : "", default_mounts[i].destination); | |
723 | if (!destination) { | |
724 | saved_errno = errno; | |
725 | free(source); | |
726 | errno = saved_errno; | |
727 | return -1; | |
728 | } | |
729 | ||
730 | mflags = add_required_remount_flags(source, destination, | |
731 | default_mounts[i].flags); | |
732 | r = safe_mount(source, destination, default_mounts[i].fstype, | |
733 | mflags, default_mounts[i].options, | |
734 | conf->rootfs.path ? conf->rootfs.mount : NULL); | |
735 | saved_errno = errno; | |
736 | if (r < 0 && errno == ENOENT) { | |
737 | INFO("Mount source or target for \"%s\" on \"%s\" does " | |
738 | "not exist. Skipping", source, destination); | |
739 | r = 0; | |
740 | } else if (r < 0) { | |
741 | SYSERROR("Failed to mount \"%s\" on \"%s\" with flags %lu", source, destination, mflags); | |
742 | } | |
743 | ||
744 | free(source); | |
745 | free(destination); | |
746 | if (r < 0) { | |
747 | errno = saved_errno; | |
748 | return -1; | |
749 | } | |
750 | } | |
751 | ||
752 | if (flags & LXC_AUTO_CGROUP_MASK) { | |
753 | int cg_flags; | |
754 | ||
755 | cg_flags = flags & (LXC_AUTO_CGROUP_MASK & ~LXC_AUTO_CGROUP_FORCE); | |
756 | /* If the type of cgroup mount was not specified, it depends on | |
757 | * the container's capabilities as to what makes sense: if we | |
758 | * have CAP_SYS_ADMIN, the read-only part can be remounted | |
759 | * read-write anyway, so we may as well default to read-write; | |
760 | * then the admin will not be given a false sense of security. | |
761 | * (And if they really want mixed r/o r/w, then they can | |
762 | * explicitly specify :mixed.) OTOH, if the container lacks | |
763 | * CAP_SYS_ADMIN, do only default to :mixed, because then the | |
764 | * container can't remount it read-write. | |
765 | */ | |
766 | if (cg_flags == LXC_AUTO_CGROUP_NOSPEC || cg_flags == LXC_AUTO_CGROUP_FULL_NOSPEC) { | |
767 | int has_sys_admin = 0; | |
768 | ||
769 | if (!lxc_list_empty(&conf->keepcaps)) | |
770 | has_sys_admin = in_caplist(CAP_SYS_ADMIN, &conf->keepcaps); | |
771 | else | |
772 | has_sys_admin = !in_caplist(CAP_SYS_ADMIN, &conf->caps); | |
773 | ||
774 | if (cg_flags == LXC_AUTO_CGROUP_NOSPEC) | |
775 | cg_flags = has_sys_admin ? LXC_AUTO_CGROUP_RW : LXC_AUTO_CGROUP_MIXED; | |
776 | else | |
777 | cg_flags = has_sys_admin ? LXC_AUTO_CGROUP_FULL_RW : LXC_AUTO_CGROUP_FULL_MIXED; | |
778 | } | |
779 | ||
780 | if (flags & LXC_AUTO_CGROUP_FORCE) | |
781 | cg_flags |= LXC_AUTO_CGROUP_FORCE; | |
782 | ||
783 | if (!handler->cgroup_ops->mount(handler->cgroup_ops, | |
784 | handler, | |
785 | conf->rootfs.path ? conf->rootfs.mount : "", | |
786 | cg_flags)) { | |
787 | SYSERROR("Failed to mount \"/sys/fs/cgroup\""); | |
788 | return -1; | |
789 | } | |
790 | } | |
791 | ||
792 | if (flags & LXC_AUTO_SHMOUNTS_MASK) { | |
793 | int ret = add_shmount_to_list(conf); | |
794 | if (ret < 0) { | |
795 | ERROR("Failed to add shmount entry to container config"); | |
796 | return -1; | |
797 | } | |
798 | } | |
799 | ||
800 | return 0; | |
801 | } | |
802 | ||
803 | static int setup_utsname(struct utsname *utsname) | |
804 | { | |
805 | int ret; | |
806 | ||
807 | if (!utsname) | |
808 | return 0; | |
809 | ||
810 | ret = sethostname(utsname->nodename, strlen(utsname->nodename)); | |
811 | if (ret < 0) { | |
812 | SYSERROR("Failed to set the hostname to \"%s\"", utsname->nodename); | |
813 | return -1; | |
814 | } | |
815 | ||
816 | INFO("Set hostname to \"%s\"", utsname->nodename); | |
817 | ||
818 | return 0; | |
819 | } | |
820 | ||
821 | struct dev_symlinks { | |
822 | const char *oldpath; | |
823 | const char *name; | |
824 | }; | |
825 | ||
826 | static const struct dev_symlinks dev_symlinks[] = { | |
827 | { "/proc/self/fd", "fd" }, | |
828 | { "/proc/self/fd/0", "stdin" }, | |
829 | { "/proc/self/fd/1", "stdout" }, | |
830 | { "/proc/self/fd/2", "stderr" }, | |
831 | }; | |
832 | ||
833 | static int lxc_setup_dev_symlinks(const struct lxc_rootfs *rootfs) | |
834 | { | |
835 | int i, ret; | |
836 | char path[PATH_MAX]; | |
837 | struct stat s; | |
838 | ||
839 | for (i = 0; i < sizeof(dev_symlinks) / sizeof(dev_symlinks[0]); i++) { | |
840 | const struct dev_symlinks *d = &dev_symlinks[i]; | |
841 | ||
842 | ret = snprintf(path, sizeof(path), "%s/dev/%s", | |
843 | rootfs->path ? rootfs->mount : "", d->name); | |
844 | if (ret < 0 || ret >= PATH_MAX) | |
845 | return -1; | |
846 | ||
847 | /* Stat the path first. If we don't get an error accept it as | |
848 | * is and don't try to create it | |
849 | */ | |
850 | ret = stat(path, &s); | |
851 | if (ret == 0) | |
852 | continue; | |
853 | ||
854 | ret = symlink(d->oldpath, path); | |
855 | if (ret && errno != EEXIST) { | |
856 | if (errno == EROFS) { | |
857 | WARN("Failed to create \"%s\". Read-only filesystem", path); | |
858 | } else { | |
859 | SYSERROR("Failed to create \"%s\"", path); | |
860 | return -1; | |
861 | } | |
862 | } | |
863 | } | |
864 | ||
865 | return 0; | |
866 | } | |
867 | ||
868 | /* Build a space-separate list of ptys to pass to systemd. */ | |
869 | static bool append_ttyname(char **pp, char *name) | |
870 | { | |
871 | char *p; | |
872 | size_t size; | |
873 | ||
874 | if (!*pp) { | |
875 | *pp = malloc(strlen(name) + strlen("container_ttys=") + 1); | |
876 | if (!*pp) | |
877 | return false; | |
878 | ||
879 | sprintf(*pp, "container_ttys=%s", name); | |
880 | return true; | |
881 | } | |
882 | ||
883 | size = strlen(*pp) + strlen(name) + 2; | |
884 | p = realloc(*pp, size); | |
885 | if (!p) | |
886 | return false; | |
887 | ||
888 | *pp = p; | |
889 | (void)strlcat(p, " ", size); | |
890 | (void)strlcat(p, name, size); | |
891 | ||
892 | return true; | |
893 | } | |
894 | ||
895 | static int lxc_setup_ttys(struct lxc_conf *conf) | |
896 | { | |
897 | int i, ret; | |
898 | const struct lxc_tty_info *ttys = &conf->ttys; | |
899 | char *ttydir = ttys->dir; | |
900 | char path[PATH_MAX], lxcpath[PATH_MAX]; | |
901 | ||
902 | if (!conf->rootfs.path) | |
903 | return 0; | |
904 | ||
905 | for (i = 0; i < ttys->max; i++) { | |
906 | struct lxc_terminal_info *tty = &ttys->tty[i]; | |
907 | ||
908 | ret = snprintf(path, sizeof(path), "/dev/tty%d", i + 1); | |
909 | if (ret < 0 || (size_t)ret >= sizeof(path)) | |
910 | return -1; | |
911 | ||
912 | if (ttydir) { | |
913 | /* create dev/lxc/tty%d" */ | |
914 | ret = snprintf(lxcpath, sizeof(lxcpath), | |
915 | "/dev/%s/tty%d", ttydir, i + 1); | |
916 | if (ret < 0 || (size_t)ret >= sizeof(lxcpath)) | |
917 | return -1; | |
918 | ||
919 | ret = mknod(lxcpath, S_IFREG | 0000, 0); | |
920 | if (ret < 0 && errno != EEXIST) { | |
921 | SYSERROR("Failed to create \"%s\"", lxcpath); | |
922 | return -1; | |
923 | } | |
924 | ||
925 | ret = unlink(path); | |
926 | if (ret < 0 && errno != ENOENT) { | |
927 | SYSERROR("Failed to unlink \"%s\"", path); | |
928 | return -1; | |
929 | } | |
930 | ||
931 | ret = mount(tty->name, lxcpath, "none", MS_BIND, 0); | |
932 | if (ret < 0) { | |
933 | SYSWARN("Failed to bind mount \"%s\" onto \"%s\"", | |
934 | tty->name, lxcpath); | |
935 | continue; | |
936 | } | |
937 | DEBUG("Bind mounted \"%s\" onto \"%s\"", tty->name, | |
938 | lxcpath); | |
939 | ||
940 | ret = snprintf(lxcpath, sizeof(lxcpath), "%s/tty%d", | |
941 | ttydir, i + 1); | |
942 | if (ret < 0 || (size_t)ret >= sizeof(lxcpath)) | |
943 | return -1; | |
944 | ||
945 | ret = symlink(lxcpath, path); | |
946 | if (ret < 0) { | |
947 | SYSERROR("Failed to create symlink \"%s\" -> \"%s\"", | |
948 | path, lxcpath); | |
949 | return -1; | |
950 | } | |
951 | } else { | |
952 | /* If we populated /dev, then we need to create | |
953 | * /dev/ttyN | |
954 | */ | |
955 | ret = mknod(path, S_IFREG | 0000, 0); | |
956 | if (ret < 0) /* this isn't fatal, continue */ | |
957 | SYSERROR("Failed to create \"%s\"", path); | |
958 | ||
959 | ret = mount(tty->name, path, "none", MS_BIND, 0); | |
960 | if (ret < 0) { | |
961 | SYSERROR("Failed to mount '%s'->'%s'", tty->name, path); | |
962 | continue; | |
963 | } | |
964 | ||
965 | DEBUG("Bind mounted \"%s\" onto \"%s\"", tty->name, path); | |
966 | } | |
967 | ||
968 | if (!append_ttyname(&conf->ttys.tty_names, tty->name)) { | |
969 | ERROR("Error setting up container_ttys string"); | |
970 | return -1; | |
971 | } | |
972 | } | |
973 | ||
974 | INFO("Finished setting up %zu /dev/tty<N> device(s)", ttys->max); | |
975 | return 0; | |
976 | } | |
977 | ||
978 | int lxc_allocate_ttys(struct lxc_conf *conf) | |
979 | { | |
980 | size_t i; | |
981 | int ret; | |
982 | struct lxc_tty_info *ttys = &conf->ttys; | |
983 | ||
984 | /* no tty in the configuration */ | |
985 | if (ttys->max == 0) | |
986 | return 0; | |
987 | ||
988 | ttys->tty = malloc(sizeof(*ttys->tty) * ttys->max); | |
989 | if (!ttys->tty) | |
990 | return -ENOMEM; | |
991 | ||
992 | for (i = 0; i < ttys->max; i++) { | |
993 | struct lxc_terminal_info *tty = &ttys->tty[i]; | |
994 | ||
995 | tty->master = -EBADF; | |
996 | tty->slave = -EBADF; | |
997 | ret = openpty(&tty->master, &tty->slave, NULL, NULL, NULL); | |
998 | if (ret < 0) { | |
999 | SYSERROR("Failed to create tty %zu", i); | |
1000 | ttys->max = i; | |
1001 | lxc_delete_tty(ttys); | |
1002 | return -ENOTTY; | |
1003 | } | |
1004 | ||
1005 | ret = ttyname_r(tty->slave, tty->name, sizeof(tty->name)); | |
1006 | if (ret < 0) { | |
1007 | SYSERROR("Failed to retrieve name of tty %zu slave", i); | |
1008 | ttys->max = i; | |
1009 | lxc_delete_tty(ttys); | |
1010 | return -ENOTTY; | |
1011 | } | |
1012 | ||
1013 | DEBUG("Created tty \"%s\" with master fd %d and slave fd %d", | |
1014 | tty->name, tty->master, tty->slave); | |
1015 | ||
1016 | /* Prevent leaking the file descriptors to the container */ | |
1017 | ret = fd_cloexec(tty->master, true); | |
1018 | if (ret < 0) | |
1019 | SYSWARN("Failed to set FD_CLOEXEC flag on master fd %d of " | |
1020 | "tty device \"%s\"", tty->master, tty->name); | |
1021 | ||
1022 | ret = fd_cloexec(tty->slave, true); | |
1023 | if (ret < 0) | |
1024 | SYSWARN("Failed to set FD_CLOEXEC flag on slave fd %d of " | |
1025 | "tty device \"%s\"", tty->slave, tty->name); | |
1026 | ||
1027 | tty->busy = 0; | |
1028 | } | |
1029 | ||
1030 | INFO("Finished creating %zu tty devices", ttys->max); | |
1031 | return 0; | |
1032 | } | |
1033 | ||
1034 | void lxc_delete_tty(struct lxc_tty_info *ttys) | |
1035 | { | |
1036 | int i; | |
1037 | ||
1038 | if (!ttys->tty) | |
1039 | return; | |
1040 | ||
1041 | for (i = 0; i < ttys->max; i++) { | |
1042 | struct lxc_terminal_info *tty = &ttys->tty[i]; | |
1043 | ||
1044 | if (tty->master >= 0) { | |
1045 | close(tty->master); | |
1046 | tty->master = -EBADF; | |
1047 | } | |
1048 | ||
1049 | if (tty->slave >= 0) { | |
1050 | close(tty->slave); | |
1051 | tty->slave = -EBADF; | |
1052 | } | |
1053 | } | |
1054 | ||
1055 | free(ttys->tty); | |
1056 | ttys->tty = NULL; | |
1057 | } | |
1058 | ||
1059 | static int lxc_send_ttys_to_parent(struct lxc_handler *handler) | |
1060 | { | |
1061 | int i; | |
1062 | int ret = -1; | |
1063 | struct lxc_conf *conf = handler->conf; | |
1064 | struct lxc_tty_info *ttys = &conf->ttys; | |
1065 | int sock = handler->data_sock[0]; | |
1066 | ||
1067 | if (ttys->max == 0) | |
1068 | return 0; | |
1069 | ||
1070 | for (i = 0; i < ttys->max; i++) { | |
1071 | int ttyfds[2]; | |
1072 | struct lxc_terminal_info *tty = &ttys->tty[i]; | |
1073 | ||
1074 | ttyfds[0] = tty->master; | |
1075 | ttyfds[1] = tty->slave; | |
1076 | ||
1077 | ret = lxc_abstract_unix_send_fds(sock, ttyfds, 2, NULL, 0); | |
1078 | if (ret < 0) | |
1079 | break; | |
1080 | ||
1081 | TRACE("Sent ty \"%s\" with master fd %d and slave fd %d to " | |
1082 | "parent", tty->name, tty->master, tty->slave); | |
1083 | } | |
1084 | ||
1085 | if (ret < 0) | |
1086 | SYSERROR("Failed to send %zu ttys to parent", ttys->max); | |
1087 | else | |
1088 | TRACE("Sent %zu ttys to parent", ttys->max); | |
1089 | ||
1090 | return ret; | |
1091 | } | |
1092 | ||
1093 | static int lxc_create_ttys(struct lxc_handler *handler) | |
1094 | { | |
1095 | int ret = -1; | |
1096 | struct lxc_conf *conf = handler->conf; | |
1097 | ||
1098 | ret = lxc_allocate_ttys(conf); | |
1099 | if (ret < 0) { | |
1100 | ERROR("Failed to allocate ttys"); | |
1101 | goto on_error; | |
1102 | } | |
1103 | ||
1104 | ret = lxc_send_ttys_to_parent(handler); | |
1105 | if (ret < 0) { | |
1106 | ERROR("Failed to send ttys to parent"); | |
1107 | goto on_error; | |
1108 | } | |
1109 | ||
1110 | if (!conf->is_execute) { | |
1111 | ret = lxc_setup_ttys(conf); | |
1112 | if (ret < 0) { | |
1113 | ERROR("Failed to setup ttys"); | |
1114 | goto on_error; | |
1115 | } | |
1116 | } | |
1117 | ||
1118 | if (conf->ttys.tty_names) { | |
1119 | ret = setenv("container_ttys", conf->ttys.tty_names, 1); | |
1120 | if (ret < 0) | |
1121 | SYSERROR("Failed to set \"container_ttys=%s\"", conf->ttys.tty_names); | |
1122 | } | |
1123 | ||
1124 | ret = 0; | |
1125 | ||
1126 | on_error: | |
1127 | lxc_delete_tty(&conf->ttys); | |
1128 | ||
1129 | return ret; | |
1130 | } | |
1131 | ||
1132 | /* Just create a path for /dev under $lxcpath/$name and in rootfs If we hit an | |
1133 | * error, log it but don't fail yet. | |
1134 | */ | |
1135 | static int mount_autodev(const char *name, const struct lxc_rootfs *rootfs, | |
1136 | const char *lxcpath) | |
1137 | { | |
1138 | int ret; | |
1139 | size_t clen; | |
1140 | char *path; | |
1141 | mode_t cur_mask; | |
1142 | ||
1143 | INFO("Preparing \"/dev\""); | |
1144 | ||
1145 | /* $(rootfs->mount) + "/dev/pts" + '\0' */ | |
1146 | clen = (rootfs->path ? strlen(rootfs->mount) : 0) + 9; | |
1147 | path = alloca(clen); | |
1148 | ||
1149 | ret = snprintf(path, clen, "%s/dev", rootfs->path ? rootfs->mount : ""); | |
1150 | if (ret < 0 || (size_t)ret >= clen) | |
1151 | return -1; | |
1152 | ||
1153 | cur_mask = umask(S_IXUSR | S_IXGRP | S_IXOTH); | |
1154 | ret = mkdir(path, S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH); | |
1155 | if (ret < 0 && errno != EEXIST) { | |
1156 | SYSERROR("Failed to create \"/dev\" directory"); | |
1157 | ret = -errno; | |
1158 | goto reset_umask; | |
1159 | } | |
1160 | ||
1161 | ret = safe_mount("none", path, "tmpfs", 0, "size=500000,mode=755", | |
1162 | rootfs->path ? rootfs->mount : NULL); | |
1163 | if (ret < 0) { | |
1164 | SYSERROR("Failed to mount tmpfs on \"%s\"", path); | |
1165 | goto reset_umask; | |
1166 | } | |
1167 | TRACE("Mounted tmpfs on \"%s\"", path); | |
1168 | ||
1169 | ret = snprintf(path, clen, "%s/dev/pts", rootfs->path ? rootfs->mount : ""); | |
1170 | if (ret < 0 || (size_t)ret >= clen) { | |
1171 | ret = -1; | |
1172 | goto reset_umask; | |
1173 | } | |
1174 | ||
1175 | /* If we are running on a devtmpfs mapping, dev/pts may already exist. | |
1176 | * If not, then create it and exit if that fails... | |
1177 | */ | |
1178 | ret = mkdir(path, S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH); | |
1179 | if (ret < 0 && errno != EEXIST) { | |
1180 | SYSERROR("Failed to create directory \"%s\"", path); | |
1181 | ret = -errno; | |
1182 | goto reset_umask; | |
1183 | } | |
1184 | ||
1185 | ret = 0; | |
1186 | ||
1187 | reset_umask: | |
1188 | (void)umask(cur_mask); | |
1189 | ||
1190 | INFO("Prepared \"/dev\""); | |
1191 | return ret; | |
1192 | } | |
1193 | ||
1194 | struct lxc_device_node { | |
1195 | const char *name; | |
1196 | const mode_t mode; | |
1197 | const int maj; | |
1198 | const int min; | |
1199 | }; | |
1200 | ||
1201 | static const struct lxc_device_node lxc_devices[] = { | |
1202 | { "full", S_IFCHR | S_IRWXU | S_IRWXG | S_IRWXO, 1, 7 }, | |
1203 | { "null", S_IFCHR | S_IRWXU | S_IRWXG | S_IRWXO, 1, 3 }, | |
1204 | { "random", S_IFCHR | S_IRWXU | S_IRWXG | S_IRWXO, 1, 8 }, | |
1205 | { "tty", S_IFCHR | S_IRWXU | S_IRWXG | S_IRWXO, 5, 0 }, | |
1206 | { "urandom", S_IFCHR | S_IRWXU | S_IRWXG | S_IRWXO, 1, 9 }, | |
1207 | { "zero", S_IFCHR | S_IRWXU | S_IRWXG | S_IRWXO, 1, 5 }, | |
1208 | }; | |
1209 | ||
1210 | ||
1211 | enum { | |
1212 | LXC_DEVNODE_BIND, | |
1213 | LXC_DEVNODE_MKNOD, | |
1214 | LXC_DEVNODE_PARTIAL, | |
1215 | LXC_DEVNODE_OPEN, | |
1216 | }; | |
1217 | ||
1218 | static int lxc_fill_autodev(const struct lxc_rootfs *rootfs) | |
1219 | { | |
1220 | int i, ret; | |
1221 | char path[PATH_MAX]; | |
1222 | mode_t cmask; | |
1223 | int use_mknod = LXC_DEVNODE_MKNOD; | |
1224 | ||
1225 | ret = snprintf(path, PATH_MAX, "%s/dev", | |
1226 | rootfs->path ? rootfs->mount : ""); | |
1227 | if (ret < 0 || ret >= PATH_MAX) | |
1228 | return -1; | |
1229 | ||
1230 | /* ignore, just don't try to fill in */ | |
1231 | if (!dir_exists(path)) | |
1232 | return 0; | |
1233 | ||
1234 | INFO("Populating \"/dev\""); | |
1235 | ||
1236 | cmask = umask(S_IXUSR | S_IXGRP | S_IXOTH); | |
1237 | for (i = 0; i < sizeof(lxc_devices) / sizeof(lxc_devices[0]); i++) { | |
1238 | char hostpath[PATH_MAX]; | |
1239 | const struct lxc_device_node *device = &lxc_devices[i]; | |
1240 | ||
1241 | ret = snprintf(path, PATH_MAX, "%s/dev/%s", | |
1242 | rootfs->path ? rootfs->mount : "", device->name); | |
1243 | if (ret < 0 || ret >= PATH_MAX) | |
1244 | return -1; | |
1245 | ||
1246 | if (use_mknod >= LXC_DEVNODE_MKNOD) { | |
1247 | ret = mknod(path, device->mode, makedev(device->maj, device->min)); | |
1248 | if (ret == 0 || (ret < 0 && errno == EEXIST)) { | |
1249 | DEBUG("Created device node \"%s\"", path); | |
1250 | } else if (ret < 0) { | |
1251 | if (errno != EPERM) { | |
1252 | SYSERROR("Failed to create device node \"%s\"", path); | |
1253 | return -1; | |
1254 | } | |
1255 | ||
1256 | use_mknod = LXC_DEVNODE_BIND; | |
1257 | } | |
1258 | ||
1259 | /* Device nodes are fully useable. */ | |
1260 | if (use_mknod == LXC_DEVNODE_OPEN) | |
1261 | continue; | |
1262 | ||
1263 | if (use_mknod == LXC_DEVNODE_MKNOD) { | |
1264 | /* See | |
1265 | * - https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=55956b59df336f6738da916dbb520b6e37df9fbd | |
1266 | * - https://lists.linuxfoundation.org/pipermail/containers/2018-June/039176.html | |
1267 | */ | |
1268 | ret = open(path, O_RDONLY | O_CLOEXEC); | |
1269 | if (ret >= 0) { | |
1270 | close(ret); | |
1271 | /* Device nodes are fully useable. */ | |
1272 | use_mknod = LXC_DEVNODE_OPEN; | |
1273 | continue; | |
1274 | } | |
1275 | ||
1276 | SYSTRACE("Failed to open \"%s\" device", path); | |
1277 | /* Device nodes are only partially useable. */ | |
1278 | use_mknod = LXC_DEVNODE_PARTIAL; | |
1279 | } | |
1280 | } | |
1281 | ||
1282 | if (use_mknod != LXC_DEVNODE_PARTIAL) { | |
1283 | /* If we are dealing with partially functional device | |
1284 | * nodes the prio mknod() call will have created the | |
1285 | * device node so we can use it as a bind-mount target. | |
1286 | */ | |
1287 | ret = mknod(path, S_IFREG | 0000, 0); | |
1288 | if (ret < 0 && errno != EEXIST) { | |
1289 | SYSERROR("Failed to create file \"%s\"", path); | |
1290 | return -1; | |
1291 | } | |
1292 | } | |
1293 | ||
1294 | /* Fallback to bind-mounting the device from the host. */ | |
1295 | ret = snprintf(hostpath, PATH_MAX, "/dev/%s", device->name); | |
1296 | if (ret < 0 || ret >= PATH_MAX) | |
1297 | return -1; | |
1298 | ||
1299 | ret = safe_mount(hostpath, path, 0, MS_BIND, NULL, | |
1300 | rootfs->path ? rootfs->mount : NULL); | |
1301 | if (ret < 0) { | |
1302 | SYSERROR("Failed to bind mount host device node \"%s\" " | |
1303 | "onto \"%s\"", hostpath, path); | |
1304 | return -1; | |
1305 | } | |
1306 | DEBUG("Bind mounted host device node \"%s\" onto \"%s\"", | |
1307 | hostpath, path); | |
1308 | } | |
1309 | (void)umask(cmask); | |
1310 | ||
1311 | INFO("Populated \"/dev\""); | |
1312 | return 0; | |
1313 | } | |
1314 | ||
1315 | static int lxc_mount_rootfs(struct lxc_conf *conf) | |
1316 | { | |
1317 | int ret; | |
1318 | struct lxc_storage *bdev; | |
1319 | const struct lxc_rootfs *rootfs = &conf->rootfs; | |
1320 | ||
1321 | if (!rootfs->path) { | |
1322 | ret = mount("", "/", NULL, MS_SLAVE | MS_REC, 0); | |
1323 | if (ret < 0) { | |
1324 | SYSERROR("Failed to remount \"/\" MS_REC | MS_SLAVE"); | |
1325 | return -1; | |
1326 | } | |
1327 | ||
1328 | return 0; | |
1329 | } | |
1330 | ||
1331 | ret = access(rootfs->mount, F_OK); | |
1332 | if (ret != 0) { | |
1333 | SYSERROR("Failed to access to \"%s\". Check it is present", | |
1334 | rootfs->mount); | |
1335 | return -1; | |
1336 | } | |
1337 | ||
1338 | bdev = storage_init(conf); | |
1339 | if (!bdev) { | |
1340 | ERROR("Failed to mount rootfs \"%s\" onto \"%s\" with options \"%s\"", | |
1341 | rootfs->path, rootfs->mount, | |
1342 | rootfs->options ? rootfs->options : "(null)"); | |
1343 | return -1; | |
1344 | } | |
1345 | ||
1346 | ret = bdev->ops->mount(bdev); | |
1347 | storage_put(bdev); | |
1348 | if (ret < 0) { | |
1349 | ERROR("Failed to mount rootfs \"%s\" onto \"%s\" with options \"%s\"", | |
1350 | rootfs->path, rootfs->mount, | |
1351 | rootfs->options ? rootfs->options : "(null)"); | |
1352 | return -1; | |
1353 | } | |
1354 | ||
1355 | DEBUG("Mounted rootfs \"%s\" onto \"%s\" with options \"%s\"", | |
1356 | rootfs->path, rootfs->mount, | |
1357 | rootfs->options ? rootfs->options : "(null)"); | |
1358 | ||
1359 | return 0; | |
1360 | } | |
1361 | ||
1362 | int lxc_chroot(const struct lxc_rootfs *rootfs) | |
1363 | { | |
1364 | int i, ret; | |
1365 | char *p, *p2; | |
1366 | char buf[LXC_LINELEN]; | |
1367 | char *nroot; | |
1368 | FILE *f; | |
1369 | char *root = rootfs->mount; | |
1370 | ||
1371 | nroot = realpath(root, NULL); | |
1372 | if (!nroot) { | |
1373 | SYSERROR("Failed to resolve \"%s\"", root); | |
1374 | return -1; | |
1375 | } | |
1376 | ||
1377 | ret = chdir("/"); | |
1378 | if (ret < 0) { | |
1379 | free(nroot); | |
1380 | return -1; | |
1381 | } | |
1382 | ||
1383 | /* We could use here MS_MOVE, but in userns this mount is locked and | |
1384 | * can't be moved. | |
1385 | */ | |
1386 | ret = mount(nroot, "/", NULL, MS_REC | MS_BIND, NULL); | |
1387 | if (ret < 0) { | |
1388 | SYSERROR("Failed to mount \"%s\" onto \"/\" as MS_REC | MS_BIND", nroot); | |
1389 | free(nroot); | |
1390 | return -1; | |
1391 | } | |
1392 | free(nroot); | |
1393 | ||
1394 | ret = mount(NULL, "/", NULL, MS_REC | MS_PRIVATE, NULL); | |
1395 | if (ret < 0) { | |
1396 | SYSERROR("Failed to remount \"/\""); | |
1397 | return -1; | |
1398 | } | |
1399 | ||
1400 | /* The following code cleans up inhereted mounts which are not required | |
1401 | * for CT. | |
1402 | * | |
1403 | * The mountinfo file shows not all mounts, if a few points have been | |
1404 | * unmounted between read operations from the mountinfo. So we need to | |
1405 | * read mountinfo a few times. | |
1406 | * | |
1407 | * This loop can be skipped if a container uses unserns, because all | |
1408 | * inherited mounts are locked and we should live with all this trash. | |
1409 | */ | |
1410 | for (;;) { | |
1411 | int progress = 0; | |
1412 | ||
1413 | f = fopen("./proc/self/mountinfo", "r"); | |
1414 | if (!f) { | |
1415 | SYSERROR("Failed to open \"/proc/self/mountinfo\""); | |
1416 | return -1; | |
1417 | } | |
1418 | ||
1419 | while (fgets(buf, LXC_LINELEN, f)) { | |
1420 | for (p = buf, i=0; p && i < 4; i++) | |
1421 | p = strchr(p+1, ' '); | |
1422 | ||
1423 | if (!p) | |
1424 | continue; | |
1425 | ||
1426 | p2 = strchr(p+1, ' '); | |
1427 | if (!p2) | |
1428 | continue; | |
1429 | ||
1430 | *p2 = '\0'; | |
1431 | *p = '.'; | |
1432 | ||
1433 | if (strcmp(p + 1, "/") == 0) | |
1434 | continue; | |
1435 | ||
1436 | if (strcmp(p + 1, "/proc") == 0) | |
1437 | continue; | |
1438 | ||
1439 | ret = umount2(p, MNT_DETACH); | |
1440 | if (ret == 0) | |
1441 | progress++; | |
1442 | } | |
1443 | ||
1444 | fclose(f); | |
1445 | ||
1446 | if (!progress) | |
1447 | break; | |
1448 | } | |
1449 | ||
1450 | /* This also can be skipped if a container uses unserns. */ | |
1451 | (void)umount2("./proc", MNT_DETACH); | |
1452 | ||
1453 | /* It is weird, but chdir("..") moves us in a new root */ | |
1454 | ret = chdir(".."); | |
1455 | if (ret < 0) { | |
1456 | SYSERROR("Failed to chdir(\"..\")"); | |
1457 | return -1; | |
1458 | } | |
1459 | ||
1460 | ret = chroot("."); | |
1461 | if (ret < 0) { | |
1462 | SYSERROR("Failed to chroot(\".\")"); | |
1463 | return -1; | |
1464 | } | |
1465 | ||
1466 | return 0; | |
1467 | } | |
1468 | ||
1469 | /* (The following explanation is copied verbatim from the kernel.) | |
1470 | * | |
1471 | * pivot_root Semantics: | |
1472 | * Moves the root file system of the current process to the directory put_old, | |
1473 | * makes new_root as the new root file system of the current process, and sets | |
1474 | * root/cwd of all processes which had them on the current root to new_root. | |
1475 | * | |
1476 | * Restrictions: | |
1477 | * The new_root and put_old must be directories, and must not be on the | |
1478 | * same file system as the current process root. The put_old must be | |
1479 | * underneath new_root, i.e. adding a non-zero number of /.. to the string | |
1480 | * pointed to by put_old must yield the same directory as new_root. No other | |
1481 | * file system may be mounted on put_old. After all, new_root is a mountpoint. | |
1482 | * | |
1483 | * Also, the current root cannot be on the 'rootfs' (initial ramfs) filesystem. | |
1484 | * See Documentation/filesystems/ramfs-rootfs-initramfs.txt for alternatives | |
1485 | * in this situation. | |
1486 | * | |
1487 | * Notes: | |
1488 | * - we don't move root/cwd if they are not at the root (reason: if something | |
1489 | * cared enough to change them, it's probably wrong to force them elsewhere) | |
1490 | * - it's okay to pick a root that isn't the root of a file system, e.g. | |
1491 | * /nfs/my_root where /nfs is the mount point. It must be a mountpoint, | |
1492 | * though, so you may need to say mount --bind /nfs/my_root /nfs/my_root | |
1493 | * first. | |
1494 | */ | |
1495 | static int lxc_pivot_root(const char *rootfs) | |
1496 | { | |
1497 | int oldroot; | |
1498 | int newroot = -1, ret = -1; | |
1499 | ||
1500 | oldroot = open("/", O_DIRECTORY | O_RDONLY | O_CLOEXEC); | |
1501 | if (oldroot < 0) { | |
1502 | SYSERROR("Failed to open old root directory"); | |
1503 | return -1; | |
1504 | } | |
1505 | ||
1506 | newroot = open(rootfs, O_DIRECTORY | O_RDONLY | O_CLOEXEC); | |
1507 | if (newroot < 0) { | |
1508 | SYSERROR("Failed to open new root directory"); | |
1509 | goto on_error; | |
1510 | } | |
1511 | ||
1512 | /* change into new root fs */ | |
1513 | ret = fchdir(newroot); | |
1514 | if (ret < 0) { | |
1515 | ret = -1; | |
1516 | SYSERROR("Failed to change to new rootfs \"%s\"", rootfs); | |
1517 | goto on_error; | |
1518 | } | |
1519 | ||
1520 | /* pivot_root into our new root fs */ | |
1521 | ret = pivot_root(".", "."); | |
1522 | if (ret < 0) { | |
1523 | ret = -1; | |
1524 | SYSERROR("Failed to pivot_root()"); | |
1525 | goto on_error; | |
1526 | } | |
1527 | ||
1528 | /* At this point the old-root is mounted on top of our new-root. To | |
1529 | * unmounted it we must not be chdir'd into it, so escape back to | |
1530 | * old-root. | |
1531 | */ | |
1532 | ret = fchdir(oldroot); | |
1533 | if (ret < 0) { | |
1534 | ret = -1; | |
1535 | SYSERROR("Failed to enter old root directory"); | |
1536 | goto on_error; | |
1537 | } | |
1538 | ||
1539 | /* Make oldroot rslave to make sure our umounts don't propagate to the | |
1540 | * host. | |
1541 | */ | |
1542 | ret = mount("", ".", "", MS_SLAVE | MS_REC, NULL); | |
1543 | if (ret < 0) { | |
1544 | ret = -1; | |
1545 | SYSERROR("Failed to make oldroot rslave"); | |
1546 | goto on_error; | |
1547 | } | |
1548 | ||
1549 | ret = umount2(".", MNT_DETACH); | |
1550 | if (ret < 0) { | |
1551 | ret = -1; | |
1552 | SYSERROR("Failed to detach old root directory"); | |
1553 | goto on_error; | |
1554 | } | |
1555 | ||
1556 | ret = fchdir(newroot); | |
1557 | if (ret < 0) { | |
1558 | ret = -1; | |
1559 | SYSERROR("Failed to re-enter new root directory"); | |
1560 | goto on_error; | |
1561 | } | |
1562 | ||
1563 | ret = 0; | |
1564 | ||
1565 | TRACE("pivot_root(\"%s\") successful", rootfs); | |
1566 | ||
1567 | on_error: | |
1568 | close(oldroot); | |
1569 | ||
1570 | if (newroot >= 0) | |
1571 | close(newroot); | |
1572 | ||
1573 | return ret; | |
1574 | } | |
1575 | ||
1576 | static int lxc_setup_rootfs_switch_root(const struct lxc_rootfs *rootfs) | |
1577 | { | |
1578 | if (!rootfs->path) { | |
1579 | DEBUG("Container does not have a rootfs"); | |
1580 | return 0; | |
1581 | } | |
1582 | ||
1583 | if (detect_ramfs_rootfs()) | |
1584 | return lxc_chroot(rootfs); | |
1585 | ||
1586 | return lxc_pivot_root(rootfs->mount); | |
1587 | } | |
1588 | ||
1589 | static const struct id_map *find_mapped_nsid_entry(struct lxc_conf *conf, | |
1590 | unsigned id, | |
1591 | enum idtype idtype) | |
1592 | { | |
1593 | struct lxc_list *it; | |
1594 | struct id_map *map; | |
1595 | struct id_map *retmap = NULL; | |
1596 | ||
1597 | /* Shortcut for container's root mappings. */ | |
1598 | if (id == 0) { | |
1599 | if (idtype == ID_TYPE_UID) | |
1600 | return conf->root_nsuid_map; | |
1601 | ||
1602 | if (idtype == ID_TYPE_GID) | |
1603 | return conf->root_nsgid_map; | |
1604 | } | |
1605 | ||
1606 | lxc_list_for_each(it, &conf->id_map) { | |
1607 | map = it->elem; | |
1608 | if (map->idtype != idtype) | |
1609 | continue; | |
1610 | ||
1611 | if (id >= map->nsid && id < map->nsid + map->range) { | |
1612 | retmap = map; | |
1613 | break; | |
1614 | } | |
1615 | } | |
1616 | ||
1617 | return retmap; | |
1618 | } | |
1619 | ||
1620 | static int lxc_setup_devpts(struct lxc_conf *conf) | |
1621 | { | |
1622 | int ret; | |
1623 | char **opts; | |
1624 | char devpts_mntopts[256]; | |
1625 | char *mntopt_sets[5]; | |
1626 | char default_devpts_mntopts[256] = "gid=5,newinstance,ptmxmode=0666,mode=0620"; | |
1627 | ||
1628 | if (conf->pty_max <= 0) { | |
1629 | DEBUG("No new devpts instance will be mounted since no pts " | |
1630 | "devices are requested"); | |
1631 | return 0; | |
1632 | } | |
1633 | ||
1634 | ret = snprintf(devpts_mntopts, sizeof(devpts_mntopts), "%s,max=%zu", | |
1635 | default_devpts_mntopts, conf->pty_max); | |
1636 | if (ret < 0 || (size_t)ret >= sizeof(devpts_mntopts)) | |
1637 | return -1; | |
1638 | ||
1639 | ret = umount2("/dev/pts", MNT_DETACH); | |
1640 | if (ret < 0) | |
1641 | SYSWARN("Failed to unmount old devpts instance"); | |
1642 | else | |
1643 | DEBUG("Unmounted old devpts instance"); | |
1644 | ||
1645 | /* Create mountpoint for devpts instance. */ | |
1646 | ret = mkdir("/dev/pts", 0755); | |
1647 | if (ret < 0 && errno != EEXIST) { | |
1648 | SYSERROR("Failed to create \"/dev/pts\" directory"); | |
1649 | return -1; | |
1650 | } | |
1651 | ||
1652 | /* gid=5 && max= */ | |
1653 | mntopt_sets[0] = devpts_mntopts; | |
1654 | ||
1655 | /* !gid=5 && max= */ | |
1656 | mntopt_sets[1] = devpts_mntopts + STRLITERALLEN("gid=5") + 1; | |
1657 | ||
1658 | /* gid=5 && !max= */ | |
1659 | mntopt_sets[2] = default_devpts_mntopts; | |
1660 | ||
1661 | /* !gid=5 && !max= */ | |
1662 | mntopt_sets[3] = default_devpts_mntopts + STRLITERALLEN("gid=5") + 1; | |
1663 | ||
1664 | /* end */ | |
1665 | mntopt_sets[4] = NULL; | |
1666 | ||
1667 | for (ret = -1, opts = mntopt_sets; opts && *opts; opts++) { | |
1668 | /* mount new devpts instance */ | |
1669 | ret = mount("devpts", "/dev/pts", "devpts", MS_NOSUID | MS_NOEXEC, *opts); | |
1670 | if (ret == 0) | |
1671 | break; | |
1672 | } | |
1673 | ||
1674 | if (ret < 0) { | |
1675 | SYSERROR("Failed to mount new devpts instance"); | |
1676 | return -1; | |
1677 | } | |
1678 | DEBUG("Mount new devpts instance with options \"%s\"", *opts); | |
1679 | ||
1680 | /* Remove any pre-existing /dev/ptmx file. */ | |
1681 | ret = remove("/dev/ptmx"); | |
1682 | if (ret < 0) { | |
1683 | if (errno != ENOENT) { | |
1684 | SYSERROR("Failed to remove existing \"/dev/ptmx\" file"); | |
1685 | return -1; | |
1686 | } | |
1687 | } else { | |
1688 | DEBUG("Removed existing \"/dev/ptmx\" file"); | |
1689 | } | |
1690 | ||
1691 | /* Create dummy /dev/ptmx file as bind mountpoint for /dev/pts/ptmx. */ | |
1692 | ret = mknod("/dev/ptmx", S_IFREG | 0000, 0); | |
1693 | if (ret < 0 && errno != EEXIST) { | |
1694 | SYSERROR("Failed to create dummy \"/dev/ptmx\" file as bind mount target"); | |
1695 | return -1; | |
1696 | } | |
1697 | DEBUG("Created dummy \"/dev/ptmx\" file as bind mount target"); | |
1698 | ||
1699 | /* Fallback option: create symlink /dev/ptmx -> /dev/pts/ptmx */ | |
1700 | ret = mount("/dev/pts/ptmx", "/dev/ptmx", NULL, MS_BIND, NULL); | |
1701 | if (!ret) { | |
1702 | DEBUG("Bind mounted \"/dev/pts/ptmx\" to \"/dev/ptmx\""); | |
1703 | return 0; | |
1704 | } else { | |
1705 | /* Fallthrough and try to create a symlink. */ | |
1706 | ERROR("Failed to bind mount \"/dev/pts/ptmx\" to \"/dev/ptmx\""); | |
1707 | } | |
1708 | ||
1709 | /* Remove the dummy /dev/ptmx file we created above. */ | |
1710 | ret = remove("/dev/ptmx"); | |
1711 | if (ret < 0) { | |
1712 | SYSERROR("Failed to remove existing \"/dev/ptmx\""); | |
1713 | return -1; | |
1714 | } | |
1715 | ||
1716 | /* Fallback option: Create symlink /dev/ptmx -> /dev/pts/ptmx. */ | |
1717 | ret = symlink("/dev/pts/ptmx", "/dev/ptmx"); | |
1718 | if (ret < 0) { | |
1719 | SYSERROR("Failed to create symlink from \"/dev/ptmx\" to \"/dev/pts/ptmx\""); | |
1720 | return -1; | |
1721 | } | |
1722 | DEBUG("Created symlink from \"/dev/ptmx\" to \"/dev/pts/ptmx\""); | |
1723 | ||
1724 | return 0; | |
1725 | } | |
1726 | ||
1727 | static int setup_personality(int persona) | |
1728 | { | |
1729 | int ret; | |
1730 | ||
1731 | #if HAVE_SYS_PERSONALITY_H | |
1732 | if (persona == -1) | |
1733 | return 0; | |
1734 | ||
1735 | ret = personality(persona); | |
1736 | if (ret < 0) { | |
1737 | SYSERROR("Failed to set personality to \"0x%x\"", persona); | |
1738 | return -1; | |
1739 | } | |
1740 | ||
1741 | INFO("Set personality to \"0x%x\"", persona); | |
1742 | #endif | |
1743 | ||
1744 | return 0; | |
1745 | } | |
1746 | ||
1747 | static int lxc_setup_dev_console(const struct lxc_rootfs *rootfs, | |
1748 | const struct lxc_terminal *console) | |
1749 | { | |
1750 | int ret; | |
1751 | char path[PATH_MAX]; | |
1752 | char *rootfs_path = rootfs->path ? rootfs->mount : ""; | |
1753 | ||
1754 | if (console->path && !strcmp(console->path, "none")) | |
1755 | return 0; | |
1756 | ||
1757 | ret = snprintf(path, sizeof(path), "%s/dev/console", rootfs_path); | |
1758 | if (ret < 0 || (size_t)ret >= sizeof(path)) | |
1759 | return -1; | |
1760 | ||
1761 | /* When we are asked to setup a console we remove any previous | |
1762 | * /dev/console bind-mounts. | |
1763 | */ | |
1764 | if (file_exists(path)) { | |
1765 | ret = lxc_unstack_mountpoint(path, false); | |
1766 | if (ret < 0) { | |
1767 | SYSERROR("Failed to unmount \"%s\"", path); | |
1768 | return -ret; | |
1769 | } else { | |
1770 | DEBUG("Cleared all (%d) mounts from \"%s\"", ret, path); | |
1771 | } | |
1772 | } | |
1773 | ||
1774 | /* For unprivileged containers autodev or automounts will already have | |
1775 | * taken care of creating /dev/console. | |
1776 | */ | |
1777 | ret = mknod(path, S_IFREG | 0000, 0); | |
1778 | if (ret < 0 && errno != EEXIST) { | |
1779 | SYSERROR("Failed to create console"); | |
1780 | return -errno; | |
1781 | } | |
1782 | ||
1783 | ret = fchmod(console->slave, S_IXUSR | S_IXGRP); | |
1784 | if (ret < 0) { | |
1785 | SYSERROR("Failed to set mode \"0%o\" to \"%s\"", | |
1786 | S_IXUSR | S_IXGRP, console->name); | |
1787 | return -errno; | |
1788 | } | |
1789 | ||
1790 | ret = safe_mount(console->name, path, "none", MS_BIND, 0, rootfs_path); | |
1791 | if (ret < 0) { | |
1792 | ERROR("Failed to mount \"%s\" on \"%s\"", console->name, path); | |
1793 | return -1; | |
1794 | } | |
1795 | ||
1796 | DEBUG("Mounted pts device \"%s\" onto \"%s\"", console->name, path); | |
1797 | return 0; | |
1798 | } | |
1799 | ||
1800 | static int lxc_setup_ttydir_console(const struct lxc_rootfs *rootfs, | |
1801 | const struct lxc_terminal *console, | |
1802 | char *ttydir) | |
1803 | { | |
1804 | int ret; | |
1805 | char path[PATH_MAX], lxcpath[PATH_MAX]; | |
1806 | char *rootfs_path = rootfs->path ? rootfs->mount : ""; | |
1807 | ||
1808 | if (console->path && !strcmp(console->path, "none")) | |
1809 | return 0; | |
1810 | ||
1811 | /* create rootfs/dev/<ttydir> directory */ | |
1812 | ret = snprintf(path, sizeof(path), "%s/dev/%s", rootfs_path, ttydir); | |
1813 | if (ret < 0 || (size_t)ret >= sizeof(path)) | |
1814 | return -1; | |
1815 | ||
1816 | ret = mkdir(path, 0755); | |
1817 | if (ret && errno != EEXIST) { | |
1818 | SYSERROR("Failed to create \"%s\"", path); | |
1819 | return -errno; | |
1820 | } | |
1821 | DEBUG("Created directory for console and tty devices at \"%s\"", path); | |
1822 | ||
1823 | ret = snprintf(lxcpath, sizeof(lxcpath), "%s/dev/%s/console", rootfs_path, ttydir); | |
1824 | if (ret < 0 || (size_t)ret >= sizeof(lxcpath)) | |
1825 | return -1; | |
1826 | ||
1827 | ret = mknod(lxcpath, S_IFREG | 0000, 0); | |
1828 | if (ret < 0 && errno != EEXIST) { | |
1829 | SYSERROR("Failed to create \"%s\"", lxcpath); | |
1830 | return -errno; | |
1831 | } | |
1832 | ||
1833 | ret = snprintf(path, sizeof(path), "%s/dev/console", rootfs_path); | |
1834 | if (ret < 0 || (size_t)ret >= sizeof(path)) | |
1835 | return -1; | |
1836 | ||
1837 | if (file_exists(path)) { | |
1838 | ret = lxc_unstack_mountpoint(path, false); | |
1839 | if (ret < 0) { | |
1840 | SYSERROR("Failed to unmount \"%s\"", path); | |
1841 | return -ret; | |
1842 | } else { | |
1843 | DEBUG("Cleared all (%d) mounts from \"%s\"", ret, path); | |
1844 | } | |
1845 | } | |
1846 | ||
1847 | ret = mknod(path, S_IFREG | 0000, 0); | |
1848 | if (ret < 0 && errno != EEXIST) { | |
1849 | SYSERROR("Failed to create console"); | |
1850 | return -errno; | |
1851 | } | |
1852 | ||
1853 | ret = fchmod(console->slave, S_IXUSR | S_IXGRP); | |
1854 | if (ret < 0) { | |
1855 | SYSERROR("Failed to set mode \"0%o\" to \"%s\"", | |
1856 | S_IXUSR | S_IXGRP, console->name); | |
1857 | return -errno; | |
1858 | } | |
1859 | ||
1860 | /* bind mount console->name to '/dev/<ttydir>/console' */ | |
1861 | ret = safe_mount(console->name, lxcpath, "none", MS_BIND, 0, rootfs_path); | |
1862 | if (ret < 0) { | |
1863 | ERROR("Failed to mount \"%s\" on \"%s\"", console->name, lxcpath); | |
1864 | return -1; | |
1865 | } | |
1866 | DEBUG("Mounted \"%s\" onto \"%s\"", console->name, lxcpath); | |
1867 | ||
1868 | /* bind mount '/dev/<ttydir>/console' to '/dev/console' */ | |
1869 | ret = safe_mount(lxcpath, path, "none", MS_BIND, 0, rootfs_path); | |
1870 | if (ret < 0) { | |
1871 | ERROR("Failed to mount \"%s\" on \"%s\"", console->name, lxcpath); | |
1872 | return -1; | |
1873 | } | |
1874 | DEBUG("Mounted \"%s\" onto \"%s\"", console->name, lxcpath); | |
1875 | ||
1876 | DEBUG("Console has been setup under \"%s\" and mounted to \"%s\"", lxcpath, path); | |
1877 | return 0; | |
1878 | } | |
1879 | ||
1880 | static int lxc_setup_console(const struct lxc_rootfs *rootfs, | |
1881 | const struct lxc_terminal *console, char *ttydir) | |
1882 | { | |
1883 | ||
1884 | if (!ttydir) | |
1885 | return lxc_setup_dev_console(rootfs, console); | |
1886 | ||
1887 | return lxc_setup_ttydir_console(rootfs, console, ttydir); | |
1888 | } | |
1889 | ||
1890 | static void parse_mntopt(char *opt, unsigned long *flags, char **data, size_t size) | |
1891 | { | |
1892 | struct mount_opt *mo; | |
1893 | ||
1894 | /* If opt is found in mount_opt, set or clear flags. | |
1895 | * Otherwise append it to data. */ | |
1896 | ||
1897 | for (mo = &mount_opt[0]; mo->name != NULL; mo++) { | |
1898 | if (strncmp(opt, mo->name, strlen(mo->name)) == 0) { | |
1899 | if (mo->clear) | |
1900 | *flags &= ~mo->flag; | |
1901 | else | |
1902 | *flags |= mo->flag; | |
1903 | return; | |
1904 | } | |
1905 | } | |
1906 | ||
1907 | if (strlen(*data)) | |
1908 | (void)strlcat(*data, ",", size); | |
1909 | ||
1910 | (void)strlcat(*data, opt, size); | |
1911 | } | |
1912 | ||
1913 | int parse_mntopts(const char *mntopts, unsigned long *mntflags, char **mntdata) | |
1914 | { | |
1915 | char *data, *p, *s; | |
1916 | size_t size; | |
1917 | ||
1918 | *mntdata = NULL; | |
1919 | *mntflags = 0L; | |
1920 | ||
1921 | if (!mntopts) | |
1922 | return 0; | |
1923 | ||
1924 | s = strdup(mntopts); | |
1925 | if (!s) | |
1926 | return -1; | |
1927 | ||
1928 | size = strlen(s) + 1; | |
1929 | data = malloc(size); | |
1930 | if (!data) { | |
1931 | free(s); | |
1932 | return -1; | |
1933 | } | |
1934 | *data = 0; | |
1935 | ||
1936 | lxc_iterate_parts(p, s, ",") | |
1937 | parse_mntopt(p, mntflags, &data, size); | |
1938 | ||
1939 | if (*data) | |
1940 | *mntdata = data; | |
1941 | else | |
1942 | free(data); | |
1943 | free(s); | |
1944 | ||
1945 | return 0; | |
1946 | } | |
1947 | ||
1948 | static void parse_propagationopt(char *opt, unsigned long *flags) | |
1949 | { | |
1950 | struct mount_opt *mo; | |
1951 | ||
1952 | /* If opt is found in propagation_opt, set or clear flags. */ | |
1953 | for (mo = &propagation_opt[0]; mo->name != NULL; mo++) { | |
1954 | if (strncmp(opt, mo->name, strlen(mo->name)) != 0) | |
1955 | continue; | |
1956 | ||
1957 | if (mo->clear) | |
1958 | *flags &= ~mo->flag; | |
1959 | else | |
1960 | *flags |= mo->flag; | |
1961 | ||
1962 | return; | |
1963 | } | |
1964 | } | |
1965 | ||
1966 | int parse_propagationopts(const char *mntopts, unsigned long *pflags) | |
1967 | { | |
1968 | char *p, *s; | |
1969 | ||
1970 | if (!mntopts) | |
1971 | return 0; | |
1972 | ||
1973 | s = strdup(mntopts); | |
1974 | if (!s) { | |
1975 | SYSERROR("Failed to allocate memory"); | |
1976 | return -ENOMEM; | |
1977 | } | |
1978 | ||
1979 | *pflags = 0L; | |
1980 | lxc_iterate_parts(p, s, ",") | |
1981 | parse_propagationopt(p, pflags); | |
1982 | free(s); | |
1983 | ||
1984 | return 0; | |
1985 | } | |
1986 | ||
1987 | static void null_endofword(char *word) | |
1988 | { | |
1989 | while (*word && *word != ' ' && *word != '\t') | |
1990 | word++; | |
1991 | *word = '\0'; | |
1992 | } | |
1993 | ||
1994 | /* skip @nfields spaces in @src */ | |
1995 | static char *get_field(char *src, int nfields) | |
1996 | { | |
1997 | int i; | |
1998 | char *p = src; | |
1999 | ||
2000 | for (i = 0; i < nfields; i++) { | |
2001 | while (*p && *p != ' ' && *p != '\t') | |
2002 | p++; | |
2003 | ||
2004 | if (!*p) | |
2005 | break; | |
2006 | ||
2007 | p++; | |
2008 | } | |
2009 | ||
2010 | return p; | |
2011 | } | |
2012 | ||
2013 | static int mount_entry(const char *fsname, const char *target, | |
2014 | const char *fstype, unsigned long mountflags, | |
2015 | unsigned long pflags, const char *data, bool optional, | |
2016 | bool dev, bool relative, const char *rootfs) | |
2017 | { | |
2018 | int ret; | |
2019 | char srcbuf[PATH_MAX]; | |
2020 | const char *srcpath = fsname; | |
2021 | #ifdef HAVE_STATVFS | |
2022 | struct statvfs sb; | |
2023 | #endif | |
2024 | ||
2025 | if (relative) { | |
2026 | ret = snprintf(srcbuf, PATH_MAX, "%s/%s", rootfs ? rootfs : "/", fsname ? fsname : ""); | |
2027 | if (ret < 0 || ret >= PATH_MAX) { | |
2028 | ERROR("source path is too long"); | |
2029 | return -1; | |
2030 | } | |
2031 | srcpath = srcbuf; | |
2032 | } | |
2033 | ||
2034 | ret = safe_mount(srcpath, target, fstype, mountflags & ~MS_REMOUNT, data, | |
2035 | rootfs); | |
2036 | if (ret < 0) { | |
2037 | if (optional) { | |
2038 | SYSINFO("Failed to mount \"%s\" on \"%s\" (optional)", | |
2039 | srcpath ? srcpath : "(null)", target); | |
2040 | return 0; | |
2041 | } | |
2042 | ||
2043 | SYSERROR("Failed to mount \"%s\" on \"%s\"", | |
2044 | srcpath ? srcpath : "(null)", target); | |
2045 | return -1; | |
2046 | } | |
2047 | ||
2048 | if ((mountflags & MS_REMOUNT) || (mountflags & MS_BIND)) { | |
2049 | unsigned long rqd_flags = 0; | |
2050 | ||
2051 | DEBUG("Remounting \"%s\" on \"%s\" to respect bind or remount " | |
2052 | "options", srcpath ? srcpath : "(none)", target ? target : "(none)"); | |
2053 | ||
2054 | if (mountflags & MS_RDONLY) | |
2055 | rqd_flags |= MS_RDONLY; | |
2056 | #ifdef HAVE_STATVFS | |
2057 | if (srcpath && statvfs(srcpath, &sb) == 0) { | |
2058 | unsigned long required_flags = rqd_flags; | |
2059 | ||
2060 | if (sb.f_flag & MS_NOSUID) | |
2061 | required_flags |= MS_NOSUID; | |
2062 | ||
2063 | if (sb.f_flag & MS_NODEV && !dev) | |
2064 | required_flags |= MS_NODEV; | |
2065 | ||
2066 | if (sb.f_flag & MS_RDONLY) | |
2067 | required_flags |= MS_RDONLY; | |
2068 | ||
2069 | if (sb.f_flag & MS_NOEXEC) | |
2070 | required_flags |= MS_NOEXEC; | |
2071 | ||
2072 | DEBUG("Flags for \"%s\" were %lu, required extra flags " | |
2073 | "are %lu", srcpath, sb.f_flag, required_flags); | |
2074 | ||
2075 | /* If this was a bind mount request, and required_flags | |
2076 | * does not have any flags which are not already in | |
2077 | * mountflags, then skip the remount. | |
2078 | */ | |
2079 | if (!(mountflags & MS_REMOUNT)) { | |
2080 | if (!(required_flags & ~mountflags) && | |
2081 | rqd_flags == 0) { | |
2082 | DEBUG("Mountflags already were %lu, " | |
2083 | "skipping remount", mountflags); | |
2084 | goto skipremount; | |
2085 | } | |
2086 | } | |
2087 | ||
2088 | mountflags |= required_flags; | |
2089 | } | |
2090 | #endif | |
2091 | ||
2092 | ret = mount(srcpath, target, fstype, mountflags | MS_REMOUNT, data); | |
2093 | if (ret < 0) { | |
2094 | if (optional) { | |
2095 | SYSINFO("Failed to mount \"%s\" on \"%s\" (optional)", | |
2096 | srcpath ? srcpath : "(null)", target); | |
2097 | return 0; | |
2098 | } | |
2099 | ||
2100 | SYSERROR("Failed to mount \"%s\" on \"%s\"", | |
2101 | srcpath ? srcpath : "(null)", target); | |
2102 | return -1; | |
2103 | } | |
2104 | } | |
2105 | ||
2106 | if (pflags) { | |
2107 | ret = mount(NULL, target, NULL, pflags, NULL); | |
2108 | if (ret < 0) { | |
2109 | if (optional) { | |
2110 | SYSINFO("Failed to change mount propagation " | |
2111 | "for \"%s\" (optional)", target); | |
2112 | return 0; | |
2113 | } else { | |
2114 | SYSERROR("Failed to change mount propagation " | |
2115 | "for \"%s\" (optional)", target); | |
2116 | return -1; | |
2117 | } | |
2118 | } | |
2119 | DEBUG("Changed mount propagation for \"%s\"", target); | |
2120 | } | |
2121 | ||
2122 | ||
2123 | #ifdef HAVE_STATVFS | |
2124 | skipremount: | |
2125 | #endif | |
2126 | DEBUG("Mounted \"%s\" on \"%s\" with filesystem type \"%s\"", | |
2127 | srcpath ? srcpath : "(null)", target, fstype); | |
2128 | ||
2129 | return 0; | |
2130 | } | |
2131 | ||
2132 | /* Remove "optional", "create=dir", and "create=file" from mntopt */ | |
2133 | static void cull_mntent_opt(struct mntent *mntent) | |
2134 | { | |
2135 | int i; | |
2136 | char *list[] = { | |
2137 | "create=dir", | |
2138 | "create=file", | |
2139 | "optional", | |
2140 | "relative", | |
2141 | NULL | |
2142 | }; | |
2143 | ||
2144 | for (i = 0; list[i]; i++) { | |
2145 | char *p, *p2; | |
2146 | ||
2147 | p = strstr(mntent->mnt_opts, list[i]); | |
2148 | if (!p) | |
2149 | continue; | |
2150 | ||
2151 | p2 = strchr(p, ','); | |
2152 | if (!p2) { | |
2153 | /* no more mntopts, so just chop it here */ | |
2154 | *p = '\0'; | |
2155 | continue; | |
2156 | } | |
2157 | ||
2158 | memmove(p, p2 + 1, strlen(p2 + 1) + 1); | |
2159 | } | |
2160 | } | |
2161 | ||
2162 | static int mount_entry_create_dir_file(const struct mntent *mntent, | |
2163 | const char *path, | |
2164 | const struct lxc_rootfs *rootfs, | |
2165 | const char *lxc_name, const char *lxc_path) | |
2166 | { | |
2167 | int ret; | |
2168 | char *p1, *p2; | |
2169 | ||
2170 | if (strncmp(mntent->mnt_type, "overlay", 7) == 0) { | |
2171 | ret = ovl_mkdir(mntent, rootfs, lxc_name, lxc_path); | |
2172 | if (ret < 0) | |
2173 | return -1; | |
2174 | } | |
2175 | ||
2176 | if (hasmntopt(mntent, "create=dir")) { | |
2177 | ret = mkdir_p(path, 0755); | |
2178 | if (ret < 0 && errno != EEXIST) { | |
2179 | SYSERROR("Failed to create directory \"%s\"", path); | |
2180 | return -1; | |
2181 | } | |
2182 | } | |
2183 | ||
2184 | if (!hasmntopt(mntent, "create=file")) | |
2185 | return 0; | |
2186 | ||
2187 | ret = access(path, F_OK); | |
2188 | if (ret == 0) | |
2189 | return 0; | |
2190 | ||
2191 | p1 = strdup(path); | |
2192 | if (!p1) | |
2193 | return -1; | |
2194 | ||
2195 | p2 = dirname(p1); | |
2196 | ||
2197 | ret = mkdir_p(p2, 0755); | |
2198 | free(p1); | |
2199 | if (ret < 0 && errno != EEXIST) { | |
2200 | SYSERROR("Failed to create directory \"%s\"", path); | |
2201 | return -1; | |
2202 | } | |
2203 | ||
2204 | ret = mknod(path, S_IFREG | 0000, 0); | |
2205 | if (ret < 0 && errno != EEXIST) | |
2206 | return -errno; | |
2207 | ||
2208 | return 0; | |
2209 | } | |
2210 | ||
2211 | /* rootfs, lxc_name, and lxc_path can be NULL when the container is created | |
2212 | * without a rootfs. */ | |
2213 | static inline int mount_entry_on_generic(struct mntent *mntent, | |
2214 | const char *path, | |
2215 | const struct lxc_rootfs *rootfs, | |
2216 | const char *lxc_name, | |
2217 | const char *lxc_path) | |
2218 | { | |
2219 | int ret; | |
2220 | unsigned long mntflags; | |
2221 | char *mntdata; | |
2222 | bool dev, optional, relative; | |
2223 | unsigned long pflags = 0; | |
2224 | char *rootfs_path = NULL; | |
2225 | ||
2226 | optional = hasmntopt(mntent, "optional") != NULL; | |
2227 | dev = hasmntopt(mntent, "dev") != NULL; | |
2228 | relative = hasmntopt(mntent, "relative") != NULL; | |
2229 | ||
2230 | if (rootfs && rootfs->path) | |
2231 | rootfs_path = rootfs->mount; | |
2232 | ||
2233 | ret = mount_entry_create_dir_file(mntent, path, rootfs, lxc_name, | |
2234 | lxc_path); | |
2235 | if (ret < 0) { | |
2236 | if (optional) | |
2237 | return 0; | |
2238 | ||
2239 | return -1; | |
2240 | } | |
2241 | cull_mntent_opt(mntent); | |
2242 | ||
2243 | ret = parse_propagationopts(mntent->mnt_opts, &pflags); | |
2244 | if (ret < 0) | |
2245 | return -1; | |
2246 | ||
2247 | ret = parse_mntopts(mntent->mnt_opts, &mntflags, &mntdata); | |
2248 | if (ret < 0) | |
2249 | return -1; | |
2250 | ||
2251 | ret = mount_entry(mntent->mnt_fsname, path, mntent->mnt_type, mntflags, | |
2252 | pflags, mntdata, optional, dev, relative, rootfs_path); | |
2253 | ||
2254 | free(mntdata); | |
2255 | return ret; | |
2256 | } | |
2257 | ||
2258 | static inline int mount_entry_on_systemfs(struct mntent *mntent) | |
2259 | { | |
2260 | int ret; | |
2261 | char path[PATH_MAX]; | |
2262 | ||
2263 | /* For containers created without a rootfs all mounts are treated as | |
2264 | * absolute paths starting at / on the host. | |
2265 | */ | |
2266 | if (mntent->mnt_dir[0] != '/') | |
2267 | ret = snprintf(path, sizeof(path), "/%s", mntent->mnt_dir); | |
2268 | else | |
2269 | ret = snprintf(path, sizeof(path), "%s", mntent->mnt_dir); | |
2270 | if (ret < 0 || ret >= sizeof(path)) | |
2271 | return -1; | |
2272 | ||
2273 | return mount_entry_on_generic(mntent, path, NULL, NULL, NULL); | |
2274 | } | |
2275 | ||
2276 | static int mount_entry_on_absolute_rootfs(struct mntent *mntent, | |
2277 | const struct lxc_rootfs *rootfs, | |
2278 | const char *lxc_name, | |
2279 | const char *lxc_path) | |
2280 | { | |
2281 | int offset; | |
2282 | char *aux; | |
2283 | const char *lxcpath; | |
2284 | char path[PATH_MAX]; | |
2285 | int ret = 0; | |
2286 | ||
2287 | lxcpath = lxc_global_config_value("lxc.lxcpath"); | |
2288 | if (!lxcpath) | |
2289 | return -1; | |
2290 | ||
2291 | /* If rootfs->path is a blockdev path, allow container fstab to use | |
2292 | * <lxcpath>/<name>/rootfs" as the target prefix. | |
2293 | */ | |
2294 | ret = snprintf(path, PATH_MAX, "%s/%s/rootfs", lxcpath, lxc_name); | |
2295 | if (ret < 0 || ret >= PATH_MAX) | |
2296 | goto skipvarlib; | |
2297 | ||
2298 | aux = strstr(mntent->mnt_dir, path); | |
2299 | if (aux) { | |
2300 | offset = strlen(path); | |
2301 | goto skipabs; | |
2302 | } | |
2303 | ||
2304 | skipvarlib: | |
2305 | aux = strstr(mntent->mnt_dir, rootfs->path); | |
2306 | if (!aux) { | |
2307 | WARN("Ignoring mount point \"%s\"", mntent->mnt_dir); | |
2308 | return ret; | |
2309 | } | |
2310 | offset = strlen(rootfs->path); | |
2311 | ||
2312 | skipabs: | |
2313 | ret = snprintf(path, PATH_MAX, "%s/%s", rootfs->mount, aux + offset); | |
2314 | if (ret < 0 || ret >= PATH_MAX) | |
2315 | return -1; | |
2316 | ||
2317 | return mount_entry_on_generic(mntent, path, rootfs, lxc_name, lxc_path); | |
2318 | } | |
2319 | ||
2320 | static int mount_entry_on_relative_rootfs(struct mntent *mntent, | |
2321 | const struct lxc_rootfs *rootfs, | |
2322 | const char *lxc_name, | |
2323 | const char *lxc_path) | |
2324 | { | |
2325 | int ret; | |
2326 | char path[PATH_MAX]; | |
2327 | ||
2328 | /* relative to root mount point */ | |
2329 | ret = snprintf(path, sizeof(path), "%s/%s", rootfs->mount, mntent->mnt_dir); | |
2330 | if (ret < 0 || (size_t)ret >= sizeof(path)) | |
2331 | return -1; | |
2332 | ||
2333 | return mount_entry_on_generic(mntent, path, rootfs, lxc_name, lxc_path); | |
2334 | } | |
2335 | ||
2336 | static int mount_file_entries(const struct lxc_conf *conf, | |
2337 | const struct lxc_rootfs *rootfs, FILE *file, | |
2338 | const char *lxc_name, const char *lxc_path) | |
2339 | { | |
2340 | char buf[4096]; | |
2341 | struct mntent mntent; | |
2342 | int ret = -1; | |
2343 | ||
2344 | while (getmntent_r(file, &mntent, buf, sizeof(buf))) { | |
2345 | if (!rootfs->path) | |
2346 | ret = mount_entry_on_systemfs(&mntent); | |
2347 | else if (mntent.mnt_dir[0] != '/') | |
2348 | ret = mount_entry_on_relative_rootfs(&mntent, rootfs, | |
2349 | lxc_name, lxc_path); | |
2350 | else | |
2351 | ret = mount_entry_on_absolute_rootfs(&mntent, rootfs, | |
2352 | lxc_name, lxc_path); | |
2353 | if (ret < 0) | |
2354 | return -1; | |
2355 | } | |
2356 | ret = 0; | |
2357 | ||
2358 | INFO("Finished setting up mounts"); | |
2359 | return ret; | |
2360 | } | |
2361 | ||
2362 | static int setup_mount(const struct lxc_conf *conf, | |
2363 | const struct lxc_rootfs *rootfs, const char *fstab, | |
2364 | const char *lxc_name, const char *lxc_path) | |
2365 | { | |
2366 | FILE *f; | |
2367 | int ret; | |
2368 | ||
2369 | if (!fstab) | |
2370 | return 0; | |
2371 | ||
2372 | f = setmntent(fstab, "r"); | |
2373 | if (!f) { | |
2374 | SYSERROR("Failed to open \"%s\"", fstab); | |
2375 | return -1; | |
2376 | } | |
2377 | ||
2378 | ret = mount_file_entries(conf, rootfs, f, lxc_name, lxc_path); | |
2379 | if (ret < 0) | |
2380 | ERROR("Failed to set up mount entries"); | |
2381 | ||
2382 | endmntent(f); | |
2383 | return ret; | |
2384 | } | |
2385 | ||
2386 | /* | |
2387 | * In order for nested containers to be able to mount /proc and /sys they need | |
2388 | * to see a "pure" proc and sysfs mount points with nothing mounted on top | |
2389 | * (like lxcfs). | |
2390 | * For this we provide proc and sysfs in /dev/.lxc/{proc,sys} while using an | |
2391 | * apparmor rule to deny access to them. This is mostly for convenience: The | |
2392 | * container's root user can mount them anyway and thus has access to the two | |
2393 | * file systems. But a non-root user in the container should not be allowed to | |
2394 | * access them as a side effect without explicitly allowing it. | |
2395 | */ | |
2396 | static const char nesting_helpers[] = | |
2397 | "proc dev/.lxc/proc proc create=dir,optional\n" | |
2398 | "sys dev/.lxc/sys sysfs create=dir,optional\n"; | |
2399 | ||
2400 | FILE *make_anonymous_mount_file(struct lxc_list *mount, | |
2401 | bool include_nesting_helpers) | |
2402 | { | |
2403 | int ret; | |
2404 | char *mount_entry; | |
2405 | struct lxc_list *iterator; | |
2406 | int fd = -1; | |
2407 | ||
2408 | fd = memfd_create(".lxc_mount_file", MFD_CLOEXEC); | |
2409 | if (fd < 0) { | |
2410 | char template[] = P_tmpdir "/.lxc_mount_file_XXXXXX"; | |
2411 | ||
2412 | if (errno != ENOSYS) | |
2413 | return NULL; | |
2414 | ||
2415 | fd = lxc_make_tmpfile(template, true); | |
2416 | if (fd < 0) { | |
2417 | SYSERROR("Could not create temporary mount file"); | |
2418 | return NULL; | |
2419 | } | |
2420 | ||
2421 | TRACE("Created temporary mount file"); | |
2422 | } | |
2423 | ||
2424 | lxc_list_for_each (iterator, mount) { | |
2425 | size_t len; | |
2426 | ||
2427 | mount_entry = iterator->elem; | |
2428 | len = strlen(mount_entry); | |
2429 | ||
2430 | ret = lxc_write_nointr(fd, mount_entry, len); | |
2431 | if (ret != len) | |
2432 | goto on_error; | |
2433 | ||
2434 | ret = lxc_write_nointr(fd, "\n", 1); | |
2435 | if (ret != 1) | |
2436 | goto on_error; | |
2437 | } | |
2438 | ||
2439 | if (include_nesting_helpers) { | |
2440 | ret = lxc_write_nointr(fd, nesting_helpers, | |
2441 | STRARRAYLEN(nesting_helpers)); | |
2442 | if (ret != STRARRAYLEN(nesting_helpers)) | |
2443 | goto on_error; | |
2444 | } | |
2445 | ||
2446 | ret = lseek(fd, 0, SEEK_SET); | |
2447 | if (ret < 0) | |
2448 | goto on_error; | |
2449 | ||
2450 | return fdopen(fd, "r+"); | |
2451 | ||
2452 | on_error: | |
2453 | SYSERROR("Failed to write mount entry to temporary mount file"); | |
2454 | close(fd); | |
2455 | return NULL; | |
2456 | } | |
2457 | ||
2458 | static int setup_mount_entries(const struct lxc_conf *conf, | |
2459 | const struct lxc_rootfs *rootfs, | |
2460 | struct lxc_list *mount, const char *lxc_name, | |
2461 | const char *lxc_path) | |
2462 | { | |
2463 | int ret; | |
2464 | FILE *f; | |
2465 | ||
2466 | f = make_anonymous_mount_file(mount, conf->lsm_aa_allow_nesting); | |
2467 | if (!f) | |
2468 | return -1; | |
2469 | ||
2470 | ret = mount_file_entries(conf, rootfs, f, lxc_name, lxc_path); | |
2471 | fclose(f); | |
2472 | ||
2473 | return ret; | |
2474 | } | |
2475 | ||
2476 | static int parse_cap(const char *cap) | |
2477 | { | |
2478 | size_t i; | |
2479 | int capid = -1; | |
2480 | size_t end = sizeof(caps_opt) / sizeof(caps_opt[0]); | |
2481 | char *ptr = NULL; | |
2482 | ||
2483 | if (strcmp(cap, "none") == 0) | |
2484 | return -2; | |
2485 | ||
2486 | for (i = 0; i < end; i++) { | |
2487 | if (strcmp(cap, caps_opt[i].name)) | |
2488 | continue; | |
2489 | ||
2490 | capid = caps_opt[i].value; | |
2491 | break; | |
2492 | } | |
2493 | ||
2494 | if (capid < 0) { | |
2495 | /* Try to see if it's numeric, so the user may specify | |
2496 | * capabilities that the running kernel knows about but we | |
2497 | * don't | |
2498 | */ | |
2499 | errno = 0; | |
2500 | capid = strtol(cap, &ptr, 10); | |
2501 | if (!ptr || *ptr != '\0' || errno != 0) | |
2502 | /* not a valid number */ | |
2503 | capid = -1; | |
2504 | else if (capid > lxc_caps_last_cap()) | |
2505 | /* we have a number but it's not a valid | |
2506 | * capability */ | |
2507 | capid = -1; | |
2508 | } | |
2509 | ||
2510 | return capid; | |
2511 | } | |
2512 | ||
2513 | int in_caplist(int cap, struct lxc_list *caps) | |
2514 | { | |
2515 | int capid; | |
2516 | struct lxc_list *iterator; | |
2517 | ||
2518 | lxc_list_for_each (iterator, caps) { | |
2519 | capid = parse_cap(iterator->elem); | |
2520 | if (capid == cap) | |
2521 | return 1; | |
2522 | } | |
2523 | ||
2524 | return 0; | |
2525 | } | |
2526 | ||
2527 | static int setup_caps(struct lxc_list *caps) | |
2528 | { | |
2529 | int capid; | |
2530 | char *drop_entry; | |
2531 | struct lxc_list *iterator; | |
2532 | ||
2533 | lxc_list_for_each (iterator, caps) { | |
2534 | int ret; | |
2535 | ||
2536 | drop_entry = iterator->elem; | |
2537 | ||
2538 | capid = parse_cap(drop_entry); | |
2539 | if (capid < 0) { | |
2540 | ERROR("unknown capability %s", drop_entry); | |
2541 | return -1; | |
2542 | } | |
2543 | ||
2544 | ret = prctl(PR_CAPBSET_DROP, prctl_arg(capid), prctl_arg(0), | |
2545 | prctl_arg(0), prctl_arg(0)); | |
2546 | if (ret < 0) { | |
2547 | SYSERROR("Failed to remove %s capability", drop_entry); | |
2548 | return -1; | |
2549 | } | |
2550 | DEBUG("Dropped %s (%d) capability", drop_entry, capid); | |
2551 | } | |
2552 | ||
2553 | DEBUG("Capabilities have been setup"); | |
2554 | return 0; | |
2555 | } | |
2556 | ||
2557 | static int dropcaps_except(struct lxc_list *caps) | |
2558 | { | |
2559 | int i, capid, numcaps; | |
2560 | char *keep_entry; | |
2561 | struct lxc_list *iterator; | |
2562 | ||
2563 | numcaps = lxc_caps_last_cap() + 1; | |
2564 | if (numcaps <= 0 || numcaps > 200) | |
2565 | return -1; | |
2566 | TRACE("Found %d capabilities", numcaps); | |
2567 | ||
2568 | /* caplist[i] is 1 if we keep capability i */ | |
2569 | int *caplist = alloca(numcaps * sizeof(int)); | |
2570 | memset(caplist, 0, numcaps * sizeof(int)); | |
2571 | ||
2572 | lxc_list_for_each (iterator, caps) { | |
2573 | keep_entry = iterator->elem; | |
2574 | ||
2575 | capid = parse_cap(keep_entry); | |
2576 | if (capid == -2) | |
2577 | continue; | |
2578 | ||
2579 | if (capid < 0) { | |
2580 | ERROR("Unknown capability %s", keep_entry); | |
2581 | return -1; | |
2582 | } | |
2583 | ||
2584 | DEBUG("Keep capability %s (%d)", keep_entry, capid); | |
2585 | caplist[capid] = 1; | |
2586 | } | |
2587 | ||
2588 | for (i = 0; i < numcaps; i++) { | |
2589 | int ret; | |
2590 | ||
2591 | if (caplist[i]) | |
2592 | continue; | |
2593 | ||
2594 | ret = prctl(PR_CAPBSET_DROP, prctl_arg(i), prctl_arg(0), | |
2595 | prctl_arg(0), prctl_arg(0)); | |
2596 | if (ret < 0) { | |
2597 | SYSERROR("Failed to remove capability %d", i); | |
2598 | return -1; | |
2599 | } | |
2600 | } | |
2601 | ||
2602 | DEBUG("Capabilities have been setup"); | |
2603 | return 0; | |
2604 | } | |
2605 | ||
2606 | static int parse_resource(const char *res) | |
2607 | { | |
2608 | int ret; | |
2609 | size_t i; | |
2610 | int resid = -1; | |
2611 | ||
2612 | for (i = 0; i < sizeof(limit_opt) / sizeof(limit_opt[0]); ++i) | |
2613 | if (strcmp(res, limit_opt[i].name) == 0) | |
2614 | return limit_opt[i].value; | |
2615 | ||
2616 | /* Try to see if it's numeric, so the user may specify | |
2617 | * resources that the running kernel knows about but | |
2618 | * we don't. | |
2619 | */ | |
2620 | ret = lxc_safe_int(res, &resid); | |
2621 | if (ret < 0) | |
2622 | return -1; | |
2623 | ||
2624 | return resid; | |
2625 | } | |
2626 | ||
2627 | int setup_resource_limits(struct lxc_list *limits, pid_t pid) | |
2628 | { | |
2629 | int resid; | |
2630 | struct lxc_list *it; | |
2631 | struct lxc_limit *lim; | |
2632 | ||
2633 | lxc_list_for_each (it, limits) { | |
2634 | lim = it->elem; | |
2635 | ||
2636 | resid = parse_resource(lim->resource); | |
2637 | if (resid < 0) { | |
2638 | ERROR("Unknown resource %s", lim->resource); | |
2639 | return -1; | |
2640 | } | |
2641 | ||
2642 | #if HAVE_PRLIMIT || HAVE_PRLIMIT64 | |
2643 | if (prlimit(pid, resid, &lim->limit, NULL) != 0) { | |
2644 | SYSERROR("Failed to set limit %s", lim->resource); | |
2645 | return -1; | |
2646 | } | |
2647 | ||
2648 | TRACE("Setup \"%s\" limit", lim->resource); | |
2649 | #else | |
2650 | ERROR("Cannot set limit \"%s\" as prlimit is missing", lim->resource); | |
2651 | return -1; | |
2652 | #endif | |
2653 | } | |
2654 | ||
2655 | return 0; | |
2656 | } | |
2657 | ||
2658 | int setup_sysctl_parameters(struct lxc_list *sysctls) | |
2659 | { | |
2660 | struct lxc_list *it; | |
2661 | struct lxc_sysctl *elem; | |
2662 | int ret = 0; | |
2663 | char *tmp = NULL; | |
2664 | char filename[PATH_MAX] = {0}; | |
2665 | ||
2666 | lxc_list_for_each (it, sysctls) { | |
2667 | elem = it->elem; | |
2668 | tmp = lxc_string_replace(".", "/", elem->key); | |
2669 | if (!tmp) { | |
2670 | ERROR("Failed to replace key %s", elem->key); | |
2671 | return -1; | |
2672 | } | |
2673 | ||
2674 | ret = snprintf(filename, sizeof(filename), "/proc/sys/%s", tmp); | |
2675 | free(tmp); | |
2676 | if (ret < 0 || (size_t)ret >= sizeof(filename)) { | |
2677 | ERROR("Error setting up sysctl parameters path"); | |
2678 | return -1; | |
2679 | } | |
2680 | ||
2681 | ret = lxc_write_to_file(filename, elem->value, | |
2682 | strlen(elem->value), false, 0666); | |
2683 | if (ret < 0) { | |
2684 | ERROR("Failed to setup sysctl parameters %s to %s", | |
2685 | elem->key, elem->value); | |
2686 | return -1; | |
2687 | } | |
2688 | } | |
2689 | ||
2690 | return 0; | |
2691 | } | |
2692 | ||
2693 | int setup_proc_filesystem(struct lxc_list *procs, pid_t pid) | |
2694 | { | |
2695 | struct lxc_list *it; | |
2696 | struct lxc_proc *elem; | |
2697 | int ret = 0; | |
2698 | char *tmp = NULL; | |
2699 | char filename[PATH_MAX] = {0}; | |
2700 | ||
2701 | lxc_list_for_each (it, procs) { | |
2702 | elem = it->elem; | |
2703 | tmp = lxc_string_replace(".", "/", elem->filename); | |
2704 | if (!tmp) { | |
2705 | ERROR("Failed to replace key %s", elem->filename); | |
2706 | return -1; | |
2707 | } | |
2708 | ||
2709 | ret = snprintf(filename, sizeof(filename), "/proc/%d/%s", pid, tmp); | |
2710 | free(tmp); | |
2711 | if (ret < 0 || (size_t)ret >= sizeof(filename)) { | |
2712 | ERROR("Error setting up proc filesystem path"); | |
2713 | return -1; | |
2714 | } | |
2715 | ||
2716 | ret = lxc_write_to_file(filename, elem->value, | |
2717 | strlen(elem->value), false, 0666); | |
2718 | if (ret < 0) { | |
2719 | ERROR("Failed to setup proc filesystem %s to %s", | |
2720 | elem->filename, elem->value); | |
2721 | return -1; | |
2722 | } | |
2723 | } | |
2724 | ||
2725 | return 0; | |
2726 | } | |
2727 | ||
2728 | static char *default_rootfs_mount = LXCROOTFSMOUNT; | |
2729 | ||
2730 | struct lxc_conf *lxc_conf_init(void) | |
2731 | { | |
2732 | int i; | |
2733 | struct lxc_conf *new; | |
2734 | ||
2735 | new = malloc(sizeof(*new)); | |
2736 | if (!new) | |
2737 | return NULL; | |
2738 | memset(new, 0, sizeof(*new)); | |
2739 | ||
2740 | new->loglevel = LXC_LOG_LEVEL_NOTSET; | |
2741 | new->personality = -1; | |
2742 | new->autodev = 1; | |
2743 | new->console.buffer_size = 0; | |
2744 | new->console.log_path = NULL; | |
2745 | new->console.log_fd = -1; | |
2746 | new->console.log_size = 0; | |
2747 | new->console.path = NULL; | |
2748 | new->console.peer = -1; | |
2749 | new->console.proxy.busy = -1; | |
2750 | new->console.proxy.master = -1; | |
2751 | new->console.proxy.slave = -1; | |
2752 | new->console.master = -1; | |
2753 | new->console.slave = -1; | |
2754 | new->console.name[0] = '\0'; | |
2755 | memset(&new->console.ringbuf, 0, sizeof(struct lxc_ringbuf)); | |
2756 | new->maincmd_fd = -1; | |
2757 | new->monitor_signal_pdeath = SIGKILL; | |
2758 | new->nbd_idx = -1; | |
2759 | new->rootfs.mount = strdup(default_rootfs_mount); | |
2760 | if (!new->rootfs.mount) { | |
2761 | free(new); | |
2762 | return NULL; | |
2763 | } | |
2764 | new->rootfs.managed = true; | |
2765 | new->logfd = -1; | |
2766 | lxc_list_init(&new->cgroup); | |
2767 | lxc_list_init(&new->cgroup2); | |
2768 | lxc_list_init(&new->network); | |
2769 | lxc_list_init(&new->mount_list); | |
2770 | lxc_list_init(&new->caps); | |
2771 | lxc_list_init(&new->keepcaps); | |
2772 | lxc_list_init(&new->id_map); | |
2773 | new->root_nsuid_map = NULL; | |
2774 | new->root_nsgid_map = NULL; | |
2775 | lxc_list_init(&new->includes); | |
2776 | lxc_list_init(&new->aliens); | |
2777 | lxc_list_init(&new->environment); | |
2778 | lxc_list_init(&new->limits); | |
2779 | lxc_list_init(&new->sysctls); | |
2780 | lxc_list_init(&new->procs); | |
2781 | new->hooks_version = 0; | |
2782 | for (i = 0; i < NUM_LXC_HOOKS; i++) | |
2783 | lxc_list_init(&new->hooks[i]); | |
2784 | lxc_list_init(&new->groups); | |
2785 | lxc_list_init(&new->state_clients); | |
2786 | new->lsm_aa_profile = NULL; | |
2787 | lxc_list_init(&new->lsm_aa_raw); | |
2788 | new->lsm_se_context = NULL; | |
2789 | new->tmp_umount_proc = false; | |
2790 | new->tmp_umount_proc = 0; | |
2791 | new->shmount.path_host = NULL; | |
2792 | new->shmount.path_cont = NULL; | |
2793 | ||
2794 | /* if running in a new user namespace, init and COMMAND | |
2795 | * default to running as UID/GID 0 when using lxc-execute */ | |
2796 | new->init_uid = 0; | |
2797 | new->init_gid = 0; | |
2798 | memset(&new->cgroup_meta, 0, sizeof(struct lxc_cgroup)); | |
2799 | memset(&new->ns_share, 0, sizeof(char *) * LXC_NS_MAX); | |
2800 | ||
2801 | return new; | |
2802 | } | |
2803 | ||
2804 | int write_id_mapping(enum idtype idtype, pid_t pid, const char *buf, | |
2805 | size_t buf_size) | |
2806 | { | |
2807 | int fd, ret; | |
2808 | char path[PATH_MAX]; | |
2809 | ||
2810 | if (geteuid() != 0 && idtype == ID_TYPE_GID) { | |
2811 | size_t buflen; | |
2812 | ||
2813 | ret = snprintf(path, PATH_MAX, "/proc/%d/setgroups", pid); | |
2814 | if (ret < 0 || ret >= PATH_MAX) | |
2815 | return -E2BIG; | |
2816 | ||
2817 | fd = open(path, O_WRONLY); | |
2818 | if (fd < 0 && errno != ENOENT) { | |
2819 | SYSERROR("Failed to open \"%s\"", path); | |
2820 | return -1; | |
2821 | } | |
2822 | ||
2823 | if (fd >= 0) { | |
2824 | buflen = STRLITERALLEN("deny\n"); | |
2825 | errno = 0; | |
2826 | ret = lxc_write_nointr(fd, "deny\n", buflen); | |
2827 | close(fd); | |
2828 | if (ret != buflen) { | |
2829 | SYSERROR("Failed to write \"deny\" to " | |
2830 | "\"/proc/%d/setgroups\"", pid); | |
2831 | return -1; | |
2832 | } | |
2833 | TRACE("Wrote \"deny\" to \"/proc/%d/setgroups\"", pid); | |
2834 | } | |
2835 | } | |
2836 | ||
2837 | ret = snprintf(path, PATH_MAX, "/proc/%d/%cid_map", pid, | |
2838 | idtype == ID_TYPE_UID ? 'u' : 'g'); | |
2839 | if (ret < 0 || ret >= PATH_MAX) | |
2840 | return -E2BIG; | |
2841 | ||
2842 | fd = open(path, O_WRONLY); | |
2843 | if (fd < 0) { | |
2844 | SYSERROR("Failed to open \"%s\"", path); | |
2845 | return -1; | |
2846 | } | |
2847 | ||
2848 | errno = 0; | |
2849 | ret = lxc_write_nointr(fd, buf, buf_size); | |
2850 | close(fd); | |
2851 | if (ret != buf_size) { | |
2852 | SYSERROR("Failed to write %cid mapping to \"%s\"", | |
2853 | idtype == ID_TYPE_UID ? 'u' : 'g', path); | |
2854 | return -1; | |
2855 | } | |
2856 | ||
2857 | return 0; | |
2858 | } | |
2859 | ||
2860 | /* Check whether a binary exist and has either CAP_SETUID, CAP_SETGID or both. | |
2861 | * | |
2862 | * @return 1 if functional binary was found | |
2863 | * @return 0 if binary exists but is lacking privilege | |
2864 | * @return -ENOENT if binary does not exist | |
2865 | * @return -EINVAL if cap to check is neither CAP_SETUID nor CAP_SETGID | |
2866 | */ | |
2867 | static int idmaptool_on_path_and_privileged(const char *binary, cap_value_t cap) | |
2868 | { | |
2869 | char *path; | |
2870 | int ret; | |
2871 | struct stat st; | |
2872 | int fret = 0; | |
2873 | ||
2874 | if (cap != CAP_SETUID && cap != CAP_SETGID) | |
2875 | return -EINVAL; | |
2876 | ||
2877 | path = on_path(binary, NULL); | |
2878 | if (!path) | |
2879 | return -ENOENT; | |
2880 | ||
2881 | ret = stat(path, &st); | |
2882 | if (ret < 0) { | |
2883 | fret = -errno; | |
2884 | goto cleanup; | |
2885 | } | |
2886 | ||
2887 | /* Check if the binary is setuid. */ | |
2888 | if (st.st_mode & S_ISUID) { | |
2889 | DEBUG("The binary \"%s\" does have the setuid bit set", path); | |
2890 | fret = 1; | |
2891 | goto cleanup; | |
2892 | } | |
2893 | ||
2894 | #if HAVE_LIBCAP && LIBCAP_SUPPORTS_FILE_CAPABILITIES | |
2895 | /* Check if it has the CAP_SETUID capability. */ | |
2896 | if ((cap & CAP_SETUID) && | |
2897 | lxc_file_cap_is_set(path, CAP_SETUID, CAP_EFFECTIVE) && | |
2898 | lxc_file_cap_is_set(path, CAP_SETUID, CAP_PERMITTED)) { | |
2899 | DEBUG("The binary \"%s\" has CAP_SETUID in its CAP_EFFECTIVE " | |
2900 | "and CAP_PERMITTED sets", path); | |
2901 | fret = 1; | |
2902 | goto cleanup; | |
2903 | } | |
2904 | ||
2905 | /* Check if it has the CAP_SETGID capability. */ | |
2906 | if ((cap & CAP_SETGID) && | |
2907 | lxc_file_cap_is_set(path, CAP_SETGID, CAP_EFFECTIVE) && | |
2908 | lxc_file_cap_is_set(path, CAP_SETGID, CAP_PERMITTED)) { | |
2909 | DEBUG("The binary \"%s\" has CAP_SETGID in its CAP_EFFECTIVE " | |
2910 | "and CAP_PERMITTED sets", path); | |
2911 | fret = 1; | |
2912 | goto cleanup; | |
2913 | } | |
2914 | #else | |
2915 | /* If we cannot check for file capabilities we need to give the benefit | |
2916 | * of the doubt. Otherwise we might fail even though all the necessary | |
2917 | * file capabilities are set. | |
2918 | */ | |
2919 | DEBUG("Cannot check for file capabilities as full capability support is " | |
2920 | "missing. Manual intervention needed"); | |
2921 | fret = 1; | |
2922 | #endif | |
2923 | ||
2924 | cleanup: | |
2925 | free(path); | |
2926 | return fret; | |
2927 | } | |
2928 | ||
2929 | int lxc_map_ids_exec_wrapper(void *args) | |
2930 | { | |
2931 | execl("/bin/sh", "sh", "-c", (char *)args, (char *)NULL); | |
2932 | return -1; | |
2933 | } | |
2934 | ||
2935 | int lxc_map_ids(struct lxc_list *idmap, pid_t pid) | |
2936 | { | |
2937 | int fill, left; | |
2938 | char u_or_g; | |
2939 | char *pos; | |
2940 | char cmd_output[PATH_MAX]; | |
2941 | struct id_map *map; | |
2942 | struct lxc_list *iterator; | |
2943 | enum idtype type; | |
2944 | /* strlen("new@idmap") = 9 | |
2945 | * + | |
2946 | * strlen(" ") = 1 | |
2947 | * + | |
2948 | * INTTYPE_TO_STRLEN(uint32_t) | |
2949 | * + | |
2950 | * strlen(" ") = 1 | |
2951 | * | |
2952 | * We add some additional space to make sure that we really have | |
2953 | * LXC_IDMAPLEN bytes available for our the {g,u]id mapping. | |
2954 | */ | |
2955 | int ret = 0, gidmap = 0, uidmap = 0; | |
2956 | char mapbuf[9 + 1 + INTTYPE_TO_STRLEN(uint32_t) + 1 + LXC_IDMAPLEN] = {0}; | |
2957 | bool had_entry = false, use_shadow = false; | |
2958 | int hostuid, hostgid; | |
2959 | ||
2960 | hostuid = geteuid(); | |
2961 | hostgid = getegid(); | |
2962 | ||
2963 | /* If new{g,u}idmap exists, that is, if shadow is handing out subuid | |
2964 | * ranges, then insist that root also reserve ranges in subuid. This | |
2965 | * will protected it by preventing another user from being handed the | |
2966 | * range by shadow. | |
2967 | */ | |
2968 | uidmap = idmaptool_on_path_and_privileged("newuidmap", CAP_SETUID); | |
2969 | if (uidmap == -ENOENT) | |
2970 | WARN("newuidmap binary is missing"); | |
2971 | else if (!uidmap) | |
2972 | WARN("newuidmap is lacking necessary privileges"); | |
2973 | ||
2974 | gidmap = idmaptool_on_path_and_privileged("newgidmap", CAP_SETGID); | |
2975 | if (gidmap == -ENOENT) | |
2976 | WARN("newgidmap binary is missing"); | |
2977 | else if (!gidmap) | |
2978 | WARN("newgidmap is lacking necessary privileges"); | |
2979 | ||
2980 | if (uidmap > 0 && gidmap > 0) { | |
2981 | DEBUG("Functional newuidmap and newgidmap binary found"); | |
2982 | use_shadow = true; | |
2983 | } else { | |
2984 | /* In case unprivileged users run application containers via | |
2985 | * execute() or a start*() there are valid cases where they may | |
2986 | * only want to map their own {g,u}id. Let's not block them from | |
2987 | * doing so by requiring geteuid() == 0. | |
2988 | */ | |
2989 | DEBUG("No newuidmap and newgidmap binary found. Trying to " | |
2990 | "write directly with euid %d", hostuid); | |
2991 | } | |
2992 | ||
2993 | /* Check if we really need to use newuidmap and newgidmap. | |
2994 | * If the user is only remapping his own {g,u}id, we don't need it. | |
2995 | */ | |
2996 | if (use_shadow && lxc_list_len(idmap) == 2) { | |
2997 | use_shadow = false; | |
2998 | lxc_list_for_each(iterator, idmap) { | |
2999 | map = iterator->elem; | |
3000 | if (map->idtype == ID_TYPE_UID && map->range == 1 && | |
3001 | map->nsid == hostuid && map->hostid == hostuid) | |
3002 | continue; | |
3003 | if (map->idtype == ID_TYPE_GID && map->range == 1 && | |
3004 | map->nsid == hostgid && map->hostid == hostgid) | |
3005 | continue; | |
3006 | use_shadow = true; | |
3007 | break; | |
3008 | } | |
3009 | } | |
3010 | ||
3011 | for (type = ID_TYPE_UID, u_or_g = 'u'; type <= ID_TYPE_GID; | |
3012 | type++, u_or_g = 'g') { | |
3013 | pos = mapbuf; | |
3014 | ||
3015 | if (use_shadow) | |
3016 | pos += sprintf(mapbuf, "new%cidmap %d", u_or_g, pid); | |
3017 | ||
3018 | lxc_list_for_each(iterator, idmap) { | |
3019 | map = iterator->elem; | |
3020 | if (map->idtype != type) | |
3021 | continue; | |
3022 | ||
3023 | had_entry = true; | |
3024 | ||
3025 | left = LXC_IDMAPLEN - (pos - mapbuf); | |
3026 | fill = snprintf(pos, left, "%s%lu %lu %lu%s", | |
3027 | use_shadow ? " " : "", map->nsid, | |
3028 | map->hostid, map->range, | |
3029 | use_shadow ? "" : "\n"); | |
3030 | if (fill <= 0 || fill >= left) { | |
3031 | /* The kernel only takes <= 4k for writes to | |
3032 | * /proc/<pid>/{g,u}id_map | |
3033 | */ | |
3034 | SYSERROR("Too many %cid mappings defined", u_or_g); | |
3035 | return -1; | |
3036 | } | |
3037 | ||
3038 | pos += fill; | |
3039 | } | |
3040 | if (!had_entry) | |
3041 | continue; | |
3042 | ||
3043 | /* Try to catch the ouput of new{g,u}idmap to make debugging | |
3044 | * easier. | |
3045 | */ | |
3046 | if (use_shadow) { | |
3047 | ret = run_command(cmd_output, sizeof(cmd_output), | |
3048 | lxc_map_ids_exec_wrapper, | |
3049 | (void *)mapbuf); | |
3050 | if (ret < 0) { | |
3051 | ERROR("new%cidmap failed to write mapping \"%s\": %s", | |
3052 | u_or_g, cmd_output, mapbuf); | |
3053 | return -1; | |
3054 | } | |
3055 | TRACE("new%cidmap wrote mapping \"%s\"", u_or_g, mapbuf); | |
3056 | } else { | |
3057 | ret = write_id_mapping(type, pid, mapbuf, pos - mapbuf); | |
3058 | if (ret < 0) { | |
3059 | ERROR("Failed to write mapping: %s", mapbuf); | |
3060 | return -1; | |
3061 | } | |
3062 | TRACE("Wrote mapping \"%s\"", mapbuf); | |
3063 | } | |
3064 | ||
3065 | memset(mapbuf, 0, sizeof(mapbuf)); | |
3066 | } | |
3067 | ||
3068 | return 0; | |
3069 | } | |
3070 | ||
3071 | /* Return the host uid/gid to which the container root is mapped in val. | |
3072 | * Return true if id was found, false otherwise. | |
3073 | */ | |
3074 | bool get_mapped_rootid(struct lxc_conf *conf, enum idtype idtype, | |
3075 | unsigned long *val) | |
3076 | { | |
3077 | unsigned nsid; | |
3078 | struct id_map *map; | |
3079 | struct lxc_list *it; | |
3080 | ||
3081 | if (idtype == ID_TYPE_UID) | |
3082 | nsid = (conf->root_nsuid_map != NULL) ? 0 : conf->init_uid; | |
3083 | else | |
3084 | nsid = (conf->root_nsgid_map != NULL) ? 0 : conf->init_gid; | |
3085 | ||
3086 | lxc_list_for_each (it, &conf->id_map) { | |
3087 | map = it->elem; | |
3088 | if (map->idtype != idtype) | |
3089 | continue; | |
3090 | if (map->nsid != nsid) | |
3091 | continue; | |
3092 | *val = map->hostid; | |
3093 | return true; | |
3094 | } | |
3095 | ||
3096 | return false; | |
3097 | } | |
3098 | ||
3099 | int mapped_hostid(unsigned id, struct lxc_conf *conf, enum idtype idtype) | |
3100 | { | |
3101 | struct id_map *map; | |
3102 | struct lxc_list *it; | |
3103 | ||
3104 | lxc_list_for_each (it, &conf->id_map) { | |
3105 | map = it->elem; | |
3106 | if (map->idtype != idtype) | |
3107 | continue; | |
3108 | ||
3109 | if (id >= map->hostid && id < map->hostid + map->range) | |
3110 | return (id - map->hostid) + map->nsid; | |
3111 | } | |
3112 | ||
3113 | return -1; | |
3114 | } | |
3115 | ||
3116 | int find_unmapped_nsid(struct lxc_conf *conf, enum idtype idtype) | |
3117 | { | |
3118 | struct id_map *map; | |
3119 | struct lxc_list *it; | |
3120 | unsigned int freeid = 0; | |
3121 | ||
3122 | again: | |
3123 | lxc_list_for_each (it, &conf->id_map) { | |
3124 | map = it->elem; | |
3125 | if (map->idtype != idtype) | |
3126 | continue; | |
3127 | ||
3128 | if (freeid >= map->nsid && freeid < map->nsid + map->range) { | |
3129 | freeid = map->nsid + map->range; | |
3130 | goto again; | |
3131 | } | |
3132 | } | |
3133 | ||
3134 | return freeid; | |
3135 | } | |
3136 | ||
3137 | int chown_mapped_root_exec_wrapper(void *args) | |
3138 | { | |
3139 | execvp("lxc-usernsexec", args); | |
3140 | return -1; | |
3141 | } | |
3142 | ||
3143 | /* chown_mapped_root: for an unprivileged user with uid/gid X to | |
3144 | * chown a dir to subuid/subgid Y, he needs to run chown as root | |
3145 | * in a userns where nsid 0 is mapped to hostuid/hostgid Y, and | |
3146 | * nsid Y is mapped to hostuid/hostgid X. That way, the container | |
3147 | * root is privileged with respect to hostuid/hostgid X, allowing | |
3148 | * him to do the chown. | |
3149 | */ | |
3150 | int chown_mapped_root(const char *path, struct lxc_conf *conf) | |
3151 | { | |
3152 | uid_t rootuid, rootgid; | |
3153 | unsigned long val; | |
3154 | int hostuid, hostgid, ret; | |
3155 | struct stat sb; | |
3156 | char map1[100], map2[100], map3[100], map4[100], map5[100]; | |
3157 | char ugid[100]; | |
3158 | const char *args1[] = {"lxc-usernsexec", | |
3159 | "-m", map1, | |
3160 | "-m", map2, | |
3161 | "-m", map3, | |
3162 | "-m", map5, | |
3163 | "--", "chown", ugid, path, | |
3164 | NULL}; | |
3165 | const char *args2[] = {"lxc-usernsexec", | |
3166 | "-m", map1, | |
3167 | "-m", map2, | |
3168 | "-m", map3, | |
3169 | "-m", map4, | |
3170 | "-m", map5, | |
3171 | "--", "chown", ugid, path, | |
3172 | NULL}; | |
3173 | char cmd_output[PATH_MAX]; | |
3174 | ||
3175 | hostuid = geteuid(); | |
3176 | hostgid = getegid(); | |
3177 | ||
3178 | if (!get_mapped_rootid(conf, ID_TYPE_UID, &val)) { | |
3179 | ERROR("No uid mapping for container root"); | |
3180 | return -1; | |
3181 | } | |
3182 | rootuid = (uid_t)val; | |
3183 | ||
3184 | if (!get_mapped_rootid(conf, ID_TYPE_GID, &val)) { | |
3185 | ERROR("No gid mapping for container root"); | |
3186 | return -1; | |
3187 | } | |
3188 | rootgid = (gid_t)val; | |
3189 | ||
3190 | if (hostuid == 0) { | |
3191 | if (chown(path, rootuid, rootgid) < 0) { | |
3192 | ERROR("Error chowning %s", path); | |
3193 | return -1; | |
3194 | } | |
3195 | ||
3196 | return 0; | |
3197 | } | |
3198 | ||
3199 | if (rootuid == hostuid) { | |
3200 | /* nothing to do */ | |
3201 | INFO("Container root is our uid; no need to chown"); | |
3202 | return 0; | |
3203 | } | |
3204 | ||
3205 | /* save the current gid of "path" */ | |
3206 | if (stat(path, &sb) < 0) { | |
3207 | ERROR("Error stat %s", path); | |
3208 | return -1; | |
3209 | } | |
3210 | ||
3211 | /* Update the path argument in case this was overlayfs. */ | |
3212 | args1[sizeof(args1) / sizeof(args1[0]) - 2] = path; | |
3213 | args2[sizeof(args2) / sizeof(args2[0]) - 2] = path; | |
3214 | ||
3215 | /* | |
3216 | * A file has to be group-owned by a gid mapped into the | |
3217 | * container, or the container won't be privileged over it. | |
3218 | */ | |
3219 | DEBUG("trying to chown \"%s\" to %d", path, hostgid); | |
3220 | if (sb.st_uid == hostuid && | |
3221 | mapped_hostid(sb.st_gid, conf, ID_TYPE_GID) < 0 && | |
3222 | chown(path, -1, hostgid) < 0) { | |
3223 | ERROR("Failed chgrping %s", path); | |
3224 | return -1; | |
3225 | } | |
3226 | ||
3227 | /* "u:0:rootuid:1" */ | |
3228 | ret = snprintf(map1, 100, "u:0:%d:1", rootuid); | |
3229 | if (ret < 0 || ret >= 100) { | |
3230 | ERROR("Error uid printing map string"); | |
3231 | return -1; | |
3232 | } | |
3233 | ||
3234 | /* "u:hostuid:hostuid:1" */ | |
3235 | ret = snprintf(map2, 100, "u:%d:%d:1", hostuid, hostuid); | |
3236 | if (ret < 0 || ret >= 100) { | |
3237 | ERROR("Error uid printing map string"); | |
3238 | return -1; | |
3239 | } | |
3240 | ||
3241 | /* "g:0:rootgid:1" */ | |
3242 | ret = snprintf(map3, 100, "g:0:%d:1", rootgid); | |
3243 | if (ret < 0 || ret >= 100) { | |
3244 | ERROR("Error gid printing map string"); | |
3245 | return -1; | |
3246 | } | |
3247 | ||
3248 | /* "g:pathgid:rootgid+pathgid:1" */ | |
3249 | ret = snprintf(map4, 100, "g:%d:%d:1", (gid_t)sb.st_gid, | |
3250 | rootgid + (gid_t)sb.st_gid); | |
3251 | if (ret < 0 || ret >= 100) { | |
3252 | ERROR("Error gid printing map string"); | |
3253 | return -1; | |
3254 | } | |
3255 | ||
3256 | /* "g:hostgid:hostgid:1" */ | |
3257 | ret = snprintf(map5, 100, "g:%d:%d:1", hostgid, hostgid); | |
3258 | if (ret < 0 || ret >= 100) { | |
3259 | ERROR("Error gid printing map string"); | |
3260 | return -1; | |
3261 | } | |
3262 | ||
3263 | /* "0:pathgid" (chown) */ | |
3264 | ret = snprintf(ugid, 100, "0:%d", (gid_t)sb.st_gid); | |
3265 | if (ret < 0 || ret >= 100) { | |
3266 | ERROR("Error owner printing format string for chown"); | |
3267 | return -1; | |
3268 | } | |
3269 | ||
3270 | if (hostgid == sb.st_gid) | |
3271 | ret = run_command(cmd_output, sizeof(cmd_output), | |
3272 | chown_mapped_root_exec_wrapper, | |
3273 | (void *)args1); | |
3274 | else | |
3275 | ret = run_command(cmd_output, sizeof(cmd_output), | |
3276 | chown_mapped_root_exec_wrapper, | |
3277 | (void *)args2); | |
3278 | if (ret < 0) | |
3279 | ERROR("lxc-usernsexec failed: %s", cmd_output); | |
3280 | ||
3281 | return ret; | |
3282 | } | |
3283 | ||
3284 | /* NOTE: Must not be called from inside the container namespace! */ | |
3285 | int lxc_create_tmp_proc_mount(struct lxc_conf *conf) | |
3286 | { | |
3287 | int mounted; | |
3288 | ||
3289 | mounted = lxc_mount_proc_if_needed(conf->rootfs.path ? conf->rootfs.mount : ""); | |
3290 | if (mounted == -1) { | |
3291 | SYSERROR("Failed to mount proc in the container"); | |
3292 | /* continue only if there is no rootfs */ | |
3293 | if (conf->rootfs.path) | |
3294 | return -1; | |
3295 | } else if (mounted == 1) { | |
3296 | conf->tmp_umount_proc = true; | |
3297 | } | |
3298 | ||
3299 | return 0; | |
3300 | } | |
3301 | ||
3302 | void tmp_proc_unmount(struct lxc_conf *lxc_conf) | |
3303 | { | |
3304 | if (!lxc_conf->tmp_umount_proc) | |
3305 | return; | |
3306 | ||
3307 | (void)umount2("/proc", MNT_DETACH); | |
3308 | lxc_conf->tmp_umount_proc = false; | |
3309 | } | |
3310 | ||
3311 | /* Walk /proc/mounts and change any shared entries to slave. */ | |
3312 | void remount_all_slave(void) | |
3313 | { | |
3314 | int memfd, mntinfo_fd, ret; | |
3315 | ssize_t copied; | |
3316 | FILE *f; | |
3317 | size_t len = 0; | |
3318 | char *line = NULL; | |
3319 | ||
3320 | mntinfo_fd = open("/proc/self/mountinfo", O_RDONLY | O_CLOEXEC); | |
3321 | if (mntinfo_fd < 0) { | |
3322 | SYSERROR("Failed to open \"/proc/self/mountinfo\""); | |
3323 | return; | |
3324 | } | |
3325 | ||
3326 | memfd = memfd_create(".lxc_mountinfo", MFD_CLOEXEC); | |
3327 | if (memfd < 0) { | |
3328 | char template[] = P_tmpdir "/.lxc_mountinfo_XXXXXX"; | |
3329 | ||
3330 | if (errno != ENOSYS) { | |
3331 | SYSERROR("Failed to create temporary in-memory file"); | |
3332 | close(mntinfo_fd); | |
3333 | return; | |
3334 | } | |
3335 | ||
3336 | memfd = lxc_make_tmpfile(template, true); | |
3337 | if (memfd < 0) { | |
3338 | close(mntinfo_fd); | |
3339 | WARN("Failed to create temporary file"); | |
3340 | return; | |
3341 | } | |
3342 | } | |
3343 | ||
3344 | again: | |
3345 | copied = lxc_sendfile_nointr(memfd, mntinfo_fd, NULL, LXC_SENDFILE_MAX); | |
3346 | if (copied < 0) { | |
3347 | if (errno == EINTR) | |
3348 | goto again; | |
3349 | ||
3350 | SYSERROR("Failed to copy \"/proc/self/mountinfo\""); | |
3351 | close(mntinfo_fd); | |
3352 | close(memfd); | |
3353 | return; | |
3354 | } | |
3355 | close(mntinfo_fd); | |
3356 | ||
3357 | /* After a successful fdopen() memfd will be closed when calling | |
3358 | * fclose(f). Calling close(memfd) afterwards is undefined. | |
3359 | */ | |
3360 | ret = lseek(memfd, 0, SEEK_SET); | |
3361 | if (ret < 0) { | |
3362 | SYSERROR("Failed to reset file descriptor offset"); | |
3363 | close(memfd); | |
3364 | return; | |
3365 | } | |
3366 | ||
3367 | f = fdopen(memfd, "r"); | |
3368 | if (!f) { | |
3369 | SYSERROR("Failed to open copy of \"/proc/self/mountinfo\" to mark " | |
3370 | "all shared. Continuing"); | |
3371 | close(memfd); | |
3372 | return; | |
3373 | } | |
3374 | ||
3375 | while (getline(&line, &len, f) != -1) { | |
3376 | int ret; | |
3377 | char *opts, *target; | |
3378 | ||
3379 | target = get_field(line, 4); | |
3380 | if (!target) | |
3381 | continue; | |
3382 | ||
3383 | opts = get_field(target, 2); | |
3384 | if (!opts) | |
3385 | continue; | |
3386 | ||
3387 | null_endofword(opts); | |
3388 | if (!strstr(opts, "shared")) | |
3389 | continue; | |
3390 | ||
3391 | null_endofword(target); | |
3392 | ret = mount(NULL, target, NULL, MS_SLAVE, NULL); | |
3393 | if (ret < 0) { | |
3394 | SYSERROR("Failed to make \"%s\" MS_SLAVE", target); | |
3395 | ERROR("Continuing..."); | |
3396 | continue; | |
3397 | } | |
3398 | TRACE("Remounted \"%s\" as MS_SLAVE", target); | |
3399 | } | |
3400 | fclose(f); | |
3401 | free(line); | |
3402 | TRACE("Remounted all mount table entries as MS_SLAVE"); | |
3403 | } | |
3404 | ||
3405 | static int lxc_execute_bind_init(struct lxc_handler *handler) | |
3406 | { | |
3407 | int ret; | |
3408 | char *p; | |
3409 | char path[PATH_MAX], destpath[PATH_MAX]; | |
3410 | struct lxc_conf *conf = handler->conf; | |
3411 | ||
3412 | /* If init exists in the container, don't bind mount a static one */ | |
3413 | p = choose_init(conf->rootfs.mount); | |
3414 | if (p) { | |
3415 | char *old = p; | |
3416 | ||
3417 | p = strdup(old + strlen(conf->rootfs.mount)); | |
3418 | free(old); | |
3419 | if (!p) | |
3420 | return -ENOMEM; | |
3421 | ||
3422 | INFO("Found existing init at \"%s\"", p); | |
3423 | goto out; | |
3424 | } | |
3425 | ||
3426 | ret = snprintf(path, PATH_MAX, SBINDIR "/init.lxc.static"); | |
3427 | if (ret < 0 || ret >= PATH_MAX) | |
3428 | return -1; | |
3429 | ||
3430 | if (!file_exists(path)) { | |
3431 | ERROR("The file \"%s\" does not exist on host", path); | |
3432 | return -1; | |
3433 | } | |
3434 | ||
3435 | ret = snprintf(destpath, PATH_MAX, "%s" P_tmpdir "%s", conf->rootfs.mount, "/.lxc-init"); | |
3436 | if (ret < 0 || ret >= PATH_MAX) | |
3437 | return -1; | |
3438 | ||
3439 | if (!file_exists(destpath)) { | |
3440 | ret = mknod(destpath, S_IFREG | 0000, 0); | |
3441 | if (ret < 0 && errno != EEXIST) { | |
3442 | SYSERROR("Failed to create dummy \"%s\" file as bind mount target", destpath); | |
3443 | return -1; | |
3444 | } | |
3445 | } | |
3446 | ||
3447 | ret = safe_mount(path, destpath, "none", MS_BIND, NULL, conf->rootfs.mount); | |
3448 | if (ret < 0) { | |
3449 | SYSERROR("Failed to bind mount lxc.init.static into container"); | |
3450 | return -1; | |
3451 | } | |
3452 | ||
3453 | p = strdup(destpath + strlen(conf->rootfs.mount)); | |
3454 | if (!p) | |
3455 | return -ENOMEM; | |
3456 | ||
3457 | INFO("Bind mounted lxc.init.static into container at \"%s\"", path); | |
3458 | out: | |
3459 | ((struct execute_args *)handler->data)->init_fd = -1; | |
3460 | ((struct execute_args *)handler->data)->init_path = p; | |
3461 | return 0; | |
3462 | } | |
3463 | ||
3464 | /* This does the work of remounting / if it is shared, calling the container | |
3465 | * pre-mount hooks, and mounting the rootfs. | |
3466 | */ | |
3467 | int lxc_setup_rootfs_prepare_root(struct lxc_conf *conf, const char *name, | |
3468 | const char *lxcpath) | |
3469 | { | |
3470 | int ret; | |
3471 | ||
3472 | if (conf->rootfs_setup) { | |
3473 | const char *path = conf->rootfs.mount; | |
3474 | ||
3475 | /* The rootfs was set up in another namespace. bind-mount it to | |
3476 | * give us a mount in our own ns so we can pivot_root to it | |
3477 | */ | |
3478 | ret = mount(path, path, "rootfs", MS_BIND, NULL); | |
3479 | if (ret < 0) { | |
3480 | ERROR("Failed to bind mount container / onto itself"); | |
3481 | return -1; | |
3482 | } | |
3483 | ||
3484 | TRACE("Bind mounted container / onto itself"); | |
3485 | return 0; | |
3486 | } | |
3487 | ||
3488 | remount_all_slave(); | |
3489 | ||
3490 | ret = run_lxc_hooks(name, "pre-mount", conf, NULL); | |
3491 | if (ret < 0) { | |
3492 | ERROR("Failed to run pre-mount hooks"); | |
3493 | return -1; | |
3494 | } | |
3495 | ||
3496 | ret = lxc_mount_rootfs(conf); | |
3497 | if (ret < 0) { | |
3498 | ERROR("Failed to setup rootfs for"); | |
3499 | return -1; | |
3500 | } | |
3501 | ||
3502 | conf->rootfs_setup = true; | |
3503 | return 0; | |
3504 | } | |
3505 | ||
3506 | static bool verify_start_hooks(struct lxc_conf *conf) | |
3507 | { | |
3508 | char path[PATH_MAX]; | |
3509 | struct lxc_list *it; | |
3510 | ||
3511 | lxc_list_for_each (it, &conf->hooks[LXCHOOK_START]) { | |
3512 | int ret; | |
3513 | char *hookname = it->elem; | |
3514 | ||
3515 | ret = snprintf(path, PATH_MAX, "%s%s", | |
3516 | conf->rootfs.path ? conf->rootfs.mount : "", | |
3517 | hookname); | |
3518 | if (ret < 0 || ret >= PATH_MAX) | |
3519 | return false; | |
3520 | ||
3521 | ret = access(path, X_OK); | |
3522 | if (ret < 0) { | |
3523 | SYSERROR("Start hook \"%s\" not found in container", | |
3524 | hookname); | |
3525 | return false; | |
3526 | } | |
3527 | ||
3528 | return true; | |
3529 | } | |
3530 | ||
3531 | return true; | |
3532 | } | |
3533 | ||
3534 | static bool execveat_supported(void) | |
3535 | { | |
3536 | lxc_raw_execveat(-1, "", NULL, NULL, AT_EMPTY_PATH); | |
3537 | if (errno == ENOSYS) | |
3538 | return false; | |
3539 | ||
3540 | return true; | |
3541 | } | |
3542 | ||
3543 | int lxc_setup(struct lxc_handler *handler) | |
3544 | { | |
3545 | int ret; | |
3546 | const char *lxcpath = handler->lxcpath, *name = handler->name; | |
3547 | struct lxc_conf *lxc_conf = handler->conf; | |
3548 | ||
3549 | ret = lxc_setup_rootfs_prepare_root(lxc_conf, name, lxcpath); | |
3550 | if (ret < 0) { | |
3551 | ERROR("Failed to setup rootfs"); | |
3552 | return -1; | |
3553 | } | |
3554 | ||
3555 | if (handler->nsfd[LXC_NS_UTS] == -1) { | |
3556 | ret = setup_utsname(lxc_conf->utsname); | |
3557 | if (ret < 0) { | |
3558 | ERROR("Failed to setup the utsname %s", name); | |
3559 | return -1; | |
3560 | } | |
3561 | } | |
3562 | ||
3563 | ret = lxc_setup_keyring(); | |
3564 | if (ret < 0) | |
3565 | return -1; | |
3566 | ||
3567 | ret = lxc_setup_network_in_child_namespaces(lxc_conf, &lxc_conf->network); | |
3568 | if (ret < 0) { | |
3569 | ERROR("Failed to setup network"); | |
3570 | return -1; | |
3571 | } | |
3572 | ||
3573 | ret = lxc_network_send_name_and_ifindex_to_parent(handler); | |
3574 | if (ret < 0) { | |
3575 | ERROR("Failed to send network device names and ifindices to parent"); | |
3576 | return -1; | |
3577 | } | |
3578 | ||
3579 | if (lxc_conf->autodev > 0) { | |
3580 | ret = mount_autodev(name, &lxc_conf->rootfs, lxcpath); | |
3581 | if (ret < 0) { | |
3582 | ERROR("Failed to mount \"/dev\""); | |
3583 | return -1; | |
3584 | } | |
3585 | } | |
3586 | ||
3587 | /* Do automatic mounts (mainly /proc and /sys), but exclude those that | |
3588 | * need to wait until other stuff has finished. | |
3589 | */ | |
3590 | ret = lxc_mount_auto_mounts(lxc_conf, lxc_conf->auto_mounts & ~LXC_AUTO_CGROUP_MASK, handler); | |
3591 | if (ret < 0) { | |
3592 | ERROR("Failed to setup first automatic mounts"); | |
3593 | return -1; | |
3594 | } | |
3595 | ||
3596 | ret = setup_mount(lxc_conf, &lxc_conf->rootfs, lxc_conf->fstab, name, lxcpath); | |
3597 | if (ret < 0) { | |
3598 | ERROR("Failed to setup mounts"); | |
3599 | return -1; | |
3600 | } | |
3601 | ||
3602 | if (lxc_conf->is_execute) { | |
3603 | if (execveat_supported()) { | |
3604 | int fd; | |
3605 | char path[PATH_MAX]; | |
3606 | ||
3607 | ret = snprintf(path, PATH_MAX, SBINDIR "/init.lxc.static"); | |
3608 | if (ret < 0 || ret >= PATH_MAX) { | |
3609 | ERROR("Path to init.lxc.static too long"); | |
3610 | return -1; | |
3611 | } | |
3612 | ||
3613 | fd = open(path, O_PATH | O_CLOEXEC); | |
3614 | if (fd < 0) { | |
3615 | SYSERROR("Unable to open lxc.init.static"); | |
3616 | return -1; | |
3617 | } | |
3618 | ||
3619 | ((struct execute_args *)handler->data)->init_fd = fd; | |
3620 | ((struct execute_args *)handler->data)->init_path = NULL; | |
3621 | } else { | |
3622 | ret = lxc_execute_bind_init(handler); | |
3623 | if (ret < 0) { | |
3624 | ERROR("Failed to bind-mount the lxc init system"); | |
3625 | return -1; | |
3626 | } | |
3627 | } | |
3628 | } | |
3629 | ||
3630 | /* Now mount only cgroups, if wanted. Before, /sys could not have been | |
3631 | * mounted. It is guaranteed to be mounted now either through | |
3632 | * automatically or via fstab entries. | |
3633 | */ | |
3634 | ret = lxc_mount_auto_mounts(lxc_conf, lxc_conf->auto_mounts & LXC_AUTO_CGROUP_MASK, handler); | |
3635 | if (ret < 0) { | |
3636 | ERROR("Failed to setup remaining automatic mounts"); | |
3637 | return -1; | |
3638 | } | |
3639 | ||
3640 | ret = run_lxc_hooks(name, "mount", lxc_conf, NULL); | |
3641 | if (ret < 0) { | |
3642 | ERROR("Failed to run mount hooks"); | |
3643 | return -1; | |
3644 | } | |
3645 | ||
3646 | if (lxc_conf->autodev > 0) { | |
3647 | ret = run_lxc_hooks(name, "autodev", lxc_conf, NULL); | |
3648 | if (ret < 0) { | |
3649 | ERROR("Failed to run autodev hooks"); | |
3650 | return -1; | |
3651 | } | |
3652 | ||
3653 | ret = lxc_fill_autodev(&lxc_conf->rootfs); | |
3654 | if (ret < 0) { | |
3655 | ERROR("Failed to populate \"/dev\""); | |
3656 | return -1; | |
3657 | } | |
3658 | } | |
3659 | ||
3660 | if (!lxc_list_empty(&lxc_conf->mount_list)) { | |
3661 | ret = setup_mount_entries(lxc_conf, &lxc_conf->rootfs, | |
3662 | &lxc_conf->mount_list, name, lxcpath); | |
3663 | if (ret < 0) { | |
3664 | ERROR("Failed to setup mount entries"); | |
3665 | return -1; | |
3666 | } | |
3667 | } | |
3668 | ||
3669 | /* Make sure any start hooks are in the container */ | |
3670 | if (!verify_start_hooks(lxc_conf)) { | |
3671 | ERROR("Failed to verify start hooks"); | |
3672 | return -1; | |
3673 | } | |
3674 | ||
3675 | ret = lxc_setup_console(&lxc_conf->rootfs, &lxc_conf->console, | |
3676 | lxc_conf->ttys.dir); | |
3677 | if (ret < 0) { | |
3678 | ERROR("Failed to setup console"); | |
3679 | return -1; | |
3680 | } | |
3681 | ||
3682 | ret = lxc_setup_dev_symlinks(&lxc_conf->rootfs); | |
3683 | if (ret < 0) { | |
3684 | ERROR("Failed to setup \"/dev\" symlinks"); | |
3685 | return -1; | |
3686 | } | |
3687 | ||
3688 | ret = lxc_create_tmp_proc_mount(lxc_conf); | |
3689 | if (ret < 0) { | |
3690 | ERROR("Failed to \"/proc\" LSMs"); | |
3691 | return -1; | |
3692 | } | |
3693 | ||
3694 | ret = lxc_setup_rootfs_switch_root(&lxc_conf->rootfs); | |
3695 | if (ret < 0) { | |
3696 | ERROR("Failed to pivot root into rootfs"); | |
3697 | return -1; | |
3698 | } | |
3699 | ||
3700 | ret = lxc_setup_devpts(lxc_conf); | |
3701 | if (ret < 0) { | |
3702 | ERROR("Failed to setup new devpts instance"); | |
3703 | return -1; | |
3704 | } | |
3705 | ||
3706 | ret = lxc_create_ttys(handler); | |
3707 | if (ret < 0) | |
3708 | return -1; | |
3709 | ||
3710 | ret = setup_personality(lxc_conf->personality); | |
3711 | if (ret < 0) { | |
3712 | ERROR("Failed to set personality"); | |
3713 | return -1; | |
3714 | } | |
3715 | ||
3716 | /* Set sysctl value to a path under /proc/sys as determined from the | |
3717 | * key. For e.g. net.ipv4.ip_forward translated to | |
3718 | * /proc/sys/net/ipv4/ip_forward. | |
3719 | */ | |
3720 | if (!lxc_list_empty(&lxc_conf->sysctls)) { | |
3721 | ret = setup_sysctl_parameters(&lxc_conf->sysctls); | |
3722 | if (ret < 0) { | |
3723 | ERROR("Failed to setup sysctl parameters"); | |
3724 | return -1; | |
3725 | } | |
3726 | } | |
3727 | ||
3728 | if (!lxc_list_empty(&lxc_conf->keepcaps)) { | |
3729 | if (!lxc_list_empty(&lxc_conf->caps)) { | |
3730 | ERROR("Container requests lxc.cap.drop and " | |
3731 | "lxc.cap.keep: either use lxc.cap.drop or " | |
3732 | "lxc.cap.keep, not both"); | |
3733 | return -1; | |
3734 | } | |
3735 | ||
3736 | if (dropcaps_except(&lxc_conf->keepcaps)) { | |
3737 | ERROR("Failed to keep capabilities"); | |
3738 | return -1; | |
3739 | } | |
3740 | } else if (setup_caps(&lxc_conf->caps)) { | |
3741 | ERROR("Failed to drop capabilities"); | |
3742 | return -1; | |
3743 | } | |
3744 | ||
3745 | NOTICE("The container \"%s\" is set up", name); | |
3746 | ||
3747 | return 0; | |
3748 | } | |
3749 | ||
3750 | int run_lxc_hooks(const char *name, char *hookname, struct lxc_conf *conf, | |
3751 | char *argv[]) | |
3752 | { | |
3753 | struct lxc_list *it; | |
3754 | int which = -1; | |
3755 | ||
3756 | if (strcmp(hookname, "pre-start") == 0) | |
3757 | which = LXCHOOK_PRESTART; | |
3758 | else if (strcmp(hookname, "start-host") == 0) | |
3759 | which = LXCHOOK_START_HOST; | |
3760 | else if (strcmp(hookname, "pre-mount") == 0) | |
3761 | which = LXCHOOK_PREMOUNT; | |
3762 | else if (strcmp(hookname, "mount") == 0) | |
3763 | which = LXCHOOK_MOUNT; | |
3764 | else if (strcmp(hookname, "autodev") == 0) | |
3765 | which = LXCHOOK_AUTODEV; | |
3766 | else if (strcmp(hookname, "start") == 0) | |
3767 | which = LXCHOOK_START; | |
3768 | else if (strcmp(hookname, "stop") == 0) | |
3769 | which = LXCHOOK_STOP; | |
3770 | else if (strcmp(hookname, "post-stop") == 0) | |
3771 | which = LXCHOOK_POSTSTOP; | |
3772 | else if (strcmp(hookname, "clone") == 0) | |
3773 | which = LXCHOOK_CLONE; | |
3774 | else if (strcmp(hookname, "destroy") == 0) | |
3775 | which = LXCHOOK_DESTROY; | |
3776 | else | |
3777 | return -1; | |
3778 | ||
3779 | lxc_list_for_each (it, &conf->hooks[which]) { | |
3780 | int ret; | |
3781 | char *hook = it->elem; | |
3782 | ||
3783 | ret = run_script_argv(name, conf->hooks_version, "lxc", hook, | |
3784 | hookname, argv); | |
3785 | if (ret < 0) | |
3786 | return -1; | |
3787 | } | |
3788 | ||
3789 | return 0; | |
3790 | } | |
3791 | ||
3792 | int lxc_clear_config_caps(struct lxc_conf *c) | |
3793 | { | |
3794 | struct lxc_list *it, *next; | |
3795 | ||
3796 | lxc_list_for_each_safe (it, &c->caps, next) { | |
3797 | lxc_list_del(it); | |
3798 | free(it->elem); | |
3799 | free(it); | |
3800 | } | |
3801 | ||
3802 | return 0; | |
3803 | } | |
3804 | ||
3805 | static int lxc_free_idmap(struct lxc_list *id_map) | |
3806 | { | |
3807 | struct lxc_list *it, *next; | |
3808 | ||
3809 | lxc_list_for_each_safe (it, id_map, next) { | |
3810 | lxc_list_del(it); | |
3811 | free(it->elem); | |
3812 | free(it); | |
3813 | } | |
3814 | ||
3815 | return 0; | |
3816 | } | |
3817 | ||
3818 | int lxc_clear_idmaps(struct lxc_conf *c) | |
3819 | { | |
3820 | return lxc_free_idmap(&c->id_map); | |
3821 | } | |
3822 | ||
3823 | int lxc_clear_config_keepcaps(struct lxc_conf *c) | |
3824 | { | |
3825 | struct lxc_list *it, *next; | |
3826 | ||
3827 | lxc_list_for_each_safe (it, &c->keepcaps, next) { | |
3828 | lxc_list_del(it); | |
3829 | free(it->elem); | |
3830 | free(it); | |
3831 | } | |
3832 | ||
3833 | return 0; | |
3834 | } | |
3835 | ||
3836 | int lxc_clear_cgroups(struct lxc_conf *c, const char *key, int version) | |
3837 | { | |
3838 | char *global_token, *namespaced_token; | |
3839 | size_t namespaced_token_len; | |
3840 | struct lxc_list *it, *next, *list; | |
3841 | const char *k = key; | |
3842 | bool all = false; | |
3843 | ||
3844 | if (version == CGROUP2_SUPER_MAGIC) { | |
3845 | global_token = "lxc.cgroup2"; | |
3846 | namespaced_token = "lxc.cgroup2."; | |
3847 | namespaced_token_len = STRLITERALLEN("lxc.cgroup2."); | |
3848 | list = &c->cgroup2; | |
3849 | } else if (version == CGROUP_SUPER_MAGIC) { | |
3850 | global_token = "lxc.cgroup"; | |
3851 | namespaced_token = "lxc.cgroup."; | |
3852 | namespaced_token_len = STRLITERALLEN("lxc.cgroup."); | |
3853 | list = &c->cgroup; | |
3854 | } else { | |
3855 | return -EINVAL; | |
3856 | } | |
3857 | ||
3858 | if (strcmp(key, global_token) == 0) | |
3859 | all = true; | |
3860 | else if (strncmp(key, namespaced_token, namespaced_token_len) == 0) | |
3861 | k += namespaced_token_len; | |
3862 | else | |
3863 | return -EINVAL; | |
3864 | ||
3865 | lxc_list_for_each_safe (it, list, next) { | |
3866 | struct lxc_cgroup *cg = it->elem; | |
3867 | ||
3868 | if (!all && strcmp(cg->subsystem, k) != 0) | |
3869 | continue; | |
3870 | ||
3871 | lxc_list_del(it); | |
3872 | free(cg->subsystem); | |
3873 | free(cg->value); | |
3874 | free(cg); | |
3875 | free(it); | |
3876 | } | |
3877 | ||
3878 | return 0; | |
3879 | } | |
3880 | ||
3881 | int lxc_clear_limits(struct lxc_conf *c, const char *key) | |
3882 | { | |
3883 | struct lxc_list *it, *next; | |
3884 | const char *k = NULL; | |
3885 | bool all = false; | |
3886 | ||
3887 | if (strcmp(key, "lxc.limit") == 0 || strcmp(key, "lxc.prlimit") == 0) | |
3888 | all = true; | |
3889 | else if (strncmp(key, "lxc.limit.", STRLITERALLEN("lxc.limit.")) == 0) | |
3890 | k = key + STRLITERALLEN("lxc.limit."); | |
3891 | else if (strncmp(key, "lxc.prlimit.", STRLITERALLEN("lxc.prlimit.")) == 0) | |
3892 | k = key + STRLITERALLEN("lxc.prlimit."); | |
3893 | else | |
3894 | return -1; | |
3895 | ||
3896 | lxc_list_for_each_safe (it, &c->limits, next) { | |
3897 | struct lxc_limit *lim = it->elem; | |
3898 | ||
3899 | if (!all && strcmp(lim->resource, k) != 0) | |
3900 | continue; | |
3901 | ||
3902 | lxc_list_del(it); | |
3903 | free(lim->resource); | |
3904 | free(lim); | |
3905 | free(it); | |
3906 | } | |
3907 | ||
3908 | return 0; | |
3909 | } | |
3910 | ||
3911 | int lxc_clear_sysctls(struct lxc_conf *c, const char *key) | |
3912 | { | |
3913 | struct lxc_list *it, *next; | |
3914 | const char *k = NULL; | |
3915 | bool all = false; | |
3916 | ||
3917 | if (strcmp(key, "lxc.sysctl") == 0) | |
3918 | all = true; | |
3919 | else if (strncmp(key, "lxc.sysctl.", STRLITERALLEN("lxc.sysctl.")) == 0) | |
3920 | k = key + STRLITERALLEN("lxc.sysctl."); | |
3921 | else | |
3922 | return -1; | |
3923 | ||
3924 | lxc_list_for_each_safe (it, &c->sysctls, next) { | |
3925 | struct lxc_sysctl *elem = it->elem; | |
3926 | ||
3927 | if (!all && strcmp(elem->key, k) != 0) | |
3928 | continue; | |
3929 | ||
3930 | lxc_list_del(it); | |
3931 | free(elem->key); | |
3932 | free(elem->value); | |
3933 | free(elem); | |
3934 | free(it); | |
3935 | } | |
3936 | ||
3937 | return 0; | |
3938 | } | |
3939 | ||
3940 | int lxc_clear_procs(struct lxc_conf *c, const char *key) | |
3941 | { | |
3942 | struct lxc_list *it, *next; | |
3943 | const char *k = NULL; | |
3944 | bool all = false; | |
3945 | ||
3946 | if (strcmp(key, "lxc.proc") == 0) | |
3947 | all = true; | |
3948 | else if (strncmp(key, "lxc.proc.", STRLITERALLEN("lxc.proc.")) == 0) | |
3949 | k = key + STRLITERALLEN("lxc.proc."); | |
3950 | else | |
3951 | return -1; | |
3952 | ||
3953 | lxc_list_for_each_safe (it, &c->procs, next) { | |
3954 | struct lxc_proc *proc = it->elem; | |
3955 | ||
3956 | if (!all && strcmp(proc->filename, k) != 0) | |
3957 | continue; | |
3958 | ||
3959 | lxc_list_del(it); | |
3960 | free(proc->filename); | |
3961 | free(proc->value); | |
3962 | free(proc); | |
3963 | free(it); | |
3964 | } | |
3965 | ||
3966 | return 0; | |
3967 | } | |
3968 | ||
3969 | int lxc_clear_groups(struct lxc_conf *c) | |
3970 | { | |
3971 | struct lxc_list *it, *next; | |
3972 | ||
3973 | lxc_list_for_each_safe (it, &c->groups, next) { | |
3974 | lxc_list_del(it); | |
3975 | free(it->elem); | |
3976 | free(it); | |
3977 | } | |
3978 | ||
3979 | return 0; | |
3980 | } | |
3981 | ||
3982 | int lxc_clear_environment(struct lxc_conf *c) | |
3983 | { | |
3984 | struct lxc_list *it, *next; | |
3985 | ||
3986 | lxc_list_for_each_safe (it, &c->environment, next) { | |
3987 | lxc_list_del(it); | |
3988 | free(it->elem); | |
3989 | free(it); | |
3990 | } | |
3991 | ||
3992 | return 0; | |
3993 | } | |
3994 | ||
3995 | int lxc_clear_mount_entries(struct lxc_conf *c) | |
3996 | { | |
3997 | struct lxc_list *it, *next; | |
3998 | ||
3999 | lxc_list_for_each_safe (it, &c->mount_list, next) { | |
4000 | lxc_list_del(it); | |
4001 | free(it->elem); | |
4002 | free(it); | |
4003 | } | |
4004 | ||
4005 | return 0; | |
4006 | } | |
4007 | ||
4008 | int lxc_clear_automounts(struct lxc_conf *c) | |
4009 | { | |
4010 | c->auto_mounts = 0; | |
4011 | return 0; | |
4012 | } | |
4013 | ||
4014 | int lxc_clear_hooks(struct lxc_conf *c, const char *key) | |
4015 | { | |
4016 | int i; | |
4017 | struct lxc_list *it, *next; | |
4018 | const char *k = NULL; | |
4019 | bool all = false, done = false; | |
4020 | ||
4021 | if (strcmp(key, "lxc.hook") == 0) | |
4022 | all = true; | |
4023 | else if (strncmp(key, "lxc.hook.", STRLITERALLEN("lxc.hook.")) == 0) | |
4024 | k = key + STRLITERALLEN("lxc.hook."); | |
4025 | else | |
4026 | return -1; | |
4027 | ||
4028 | for (i = 0; i < NUM_LXC_HOOKS; i++) { | |
4029 | if (all || strcmp(k, lxchook_names[i]) == 0) { | |
4030 | lxc_list_for_each_safe (it, &c->hooks[i], next) { | |
4031 | lxc_list_del(it); | |
4032 | free(it->elem); | |
4033 | free(it); | |
4034 | } | |
4035 | ||
4036 | done = true; | |
4037 | } | |
4038 | } | |
4039 | ||
4040 | if (!done) { | |
4041 | ERROR("Invalid hook key: %s", key); | |
4042 | return -1; | |
4043 | } | |
4044 | ||
4045 | return 0; | |
4046 | } | |
4047 | ||
4048 | static inline void lxc_clear_aliens(struct lxc_conf *conf) | |
4049 | { | |
4050 | struct lxc_list *it, *next; | |
4051 | ||
4052 | lxc_list_for_each_safe (it, &conf->aliens, next) { | |
4053 | lxc_list_del(it); | |
4054 | free(it->elem); | |
4055 | free(it); | |
4056 | } | |
4057 | } | |
4058 | ||
4059 | void lxc_clear_includes(struct lxc_conf *conf) | |
4060 | { | |
4061 | struct lxc_list *it, *next; | |
4062 | ||
4063 | lxc_list_for_each_safe (it, &conf->includes, next) { | |
4064 | lxc_list_del(it); | |
4065 | free(it->elem); | |
4066 | free(it); | |
4067 | } | |
4068 | } | |
4069 | ||
4070 | int lxc_clear_apparmor_raw(struct lxc_conf *c) | |
4071 | { | |
4072 | struct lxc_list *it, *next; | |
4073 | ||
4074 | lxc_list_for_each_safe (it, &c->lsm_aa_raw, next) { | |
4075 | lxc_list_del(it); | |
4076 | free(it->elem); | |
4077 | free(it); | |
4078 | } | |
4079 | ||
4080 | return 0; | |
4081 | } | |
4082 | ||
4083 | void lxc_conf_free(struct lxc_conf *conf) | |
4084 | { | |
4085 | if (!conf) | |
4086 | return; | |
4087 | ||
4088 | if (current_config == conf) | |
4089 | current_config = NULL; | |
4090 | lxc_terminal_conf_free(&conf->console); | |
4091 | free(conf->rootfs.mount); | |
4092 | free(conf->rootfs.bdev_type); | |
4093 | free(conf->rootfs.options); | |
4094 | free(conf->rootfs.path); | |
4095 | free(conf->logfile); | |
4096 | if (conf->logfd != -1) | |
4097 | close(conf->logfd); | |
4098 | free(conf->utsname); | |
4099 | free(conf->ttys.dir); | |
4100 | free(conf->ttys.tty_names); | |
4101 | free(conf->fstab); | |
4102 | free(conf->rcfile); | |
4103 | free(conf->execute_cmd); | |
4104 | free(conf->init_cmd); | |
4105 | free(conf->init_cwd); | |
4106 | free(conf->unexpanded_config); | |
4107 | free(conf->syslog); | |
4108 | lxc_free_networks(&conf->network); | |
4109 | free(conf->lsm_aa_profile); | |
4110 | free(conf->lsm_aa_profile_computed); | |
4111 | free(conf->lsm_se_context); | |
4112 | lxc_seccomp_free(conf); | |
4113 | lxc_clear_config_caps(conf); | |
4114 | lxc_clear_config_keepcaps(conf); | |
4115 | lxc_clear_cgroups(conf, "lxc.cgroup", CGROUP_SUPER_MAGIC); | |
4116 | lxc_clear_cgroups(conf, "lxc.cgroup2", CGROUP2_SUPER_MAGIC); | |
4117 | lxc_clear_hooks(conf, "lxc.hook"); | |
4118 | lxc_clear_mount_entries(conf); | |
4119 | lxc_clear_idmaps(conf); | |
4120 | lxc_clear_groups(conf); | |
4121 | lxc_clear_includes(conf); | |
4122 | lxc_clear_aliens(conf); | |
4123 | lxc_clear_environment(conf); | |
4124 | lxc_clear_limits(conf, "lxc.prlimit"); | |
4125 | lxc_clear_sysctls(conf, "lxc.sysctl"); | |
4126 | lxc_clear_procs(conf, "lxc.proc"); | |
4127 | lxc_clear_apparmor_raw(conf); | |
4128 | free(conf->cgroup_meta.dir); | |
4129 | free(conf->cgroup_meta.controllers); | |
4130 | free(conf->shmount.path_host); | |
4131 | free(conf->shmount.path_cont); | |
4132 | free(conf); | |
4133 | } | |
4134 | ||
4135 | struct userns_fn_data { | |
4136 | int (*fn)(void *); | |
4137 | const char *fn_name; | |
4138 | void *arg; | |
4139 | int p[2]; | |
4140 | }; | |
4141 | ||
4142 | static int run_userns_fn(void *data) | |
4143 | { | |
4144 | int ret; | |
4145 | char c; | |
4146 | struct userns_fn_data *d = data; | |
4147 | ||
4148 | /* Close write end of the pipe. */ | |
4149 | close(d->p[1]); | |
4150 | ||
4151 | /* Wait for parent to finish establishing a new mapping in the user | |
4152 | * namespace we are executing in. | |
4153 | */ | |
4154 | ret = lxc_read_nointr(d->p[0], &c, 1); | |
4155 | /* Close read end of the pipe. */ | |
4156 | close(d->p[0]); | |
4157 | if (ret != 1) | |
4158 | return -1; | |
4159 | ||
4160 | if (d->fn_name) | |
4161 | TRACE("Calling function \"%s\"", d->fn_name); | |
4162 | ||
4163 | /* Call function to run. */ | |
4164 | return d->fn(d->arg); | |
4165 | } | |
4166 | ||
4167 | static struct id_map *mapped_nsid_add(struct lxc_conf *conf, unsigned id, | |
4168 | enum idtype idtype) | |
4169 | { | |
4170 | const struct id_map *map; | |
4171 | struct id_map *retmap; | |
4172 | ||
4173 | map = find_mapped_nsid_entry(conf, id, idtype); | |
4174 | if (!map) | |
4175 | return NULL; | |
4176 | ||
4177 | retmap = malloc(sizeof(*retmap)); | |
4178 | if (!retmap) | |
4179 | return NULL; | |
4180 | ||
4181 | memcpy(retmap, map, sizeof(*retmap)); | |
4182 | return retmap; | |
4183 | } | |
4184 | ||
4185 | static struct id_map *find_mapped_hostid_entry(struct lxc_conf *conf, | |
4186 | unsigned id, enum idtype idtype) | |
4187 | { | |
4188 | struct id_map *map; | |
4189 | struct lxc_list *it; | |
4190 | struct id_map *retmap = NULL; | |
4191 | ||
4192 | lxc_list_for_each (it, &conf->id_map) { | |
4193 | map = it->elem; | |
4194 | if (map->idtype != idtype) | |
4195 | continue; | |
4196 | ||
4197 | if (id >= map->hostid && id < map->hostid + map->range) { | |
4198 | retmap = map; | |
4199 | break; | |
4200 | } | |
4201 | } | |
4202 | ||
4203 | return retmap; | |
4204 | } | |
4205 | ||
4206 | /* Allocate a new {g,u}id mapping for the given {g,u}id. Re-use an already | |
4207 | * existing one or establish a new one. | |
4208 | */ | |
4209 | static struct id_map *mapped_hostid_add(struct lxc_conf *conf, uid_t id, | |
4210 | enum idtype type) | |
4211 | { | |
4212 | int hostid_mapped; | |
4213 | struct id_map *entry = NULL, *tmp = NULL; | |
4214 | ||
4215 | entry = malloc(sizeof(*entry)); | |
4216 | if (!entry) | |
4217 | return NULL; | |
4218 | ||
4219 | /* Reuse existing mapping. */ | |
4220 | tmp = find_mapped_hostid_entry(conf, id, type); | |
4221 | if (tmp) | |
4222 | return memcpy(entry, tmp, sizeof(*entry)); | |
4223 | ||
4224 | /* Find new mapping. */ | |
4225 | hostid_mapped = find_unmapped_nsid(conf, type); | |
4226 | if (hostid_mapped < 0) { | |
4227 | DEBUG("Failed to find free mapping for id %d", id); | |
4228 | free(entry); | |
4229 | return NULL; | |
4230 | } | |
4231 | ||
4232 | entry->idtype = type; | |
4233 | entry->nsid = hostid_mapped; | |
4234 | entry->hostid = (unsigned long)id; | |
4235 | entry->range = 1; | |
4236 | ||
4237 | return entry; | |
4238 | } | |
4239 | ||
4240 | struct lxc_list *get_minimal_idmap(struct lxc_conf *conf) | |
4241 | { | |
4242 | uid_t euid, egid; | |
4243 | uid_t nsuid = (conf->root_nsuid_map != NULL) ? 0 : conf->init_uid; | |
4244 | gid_t nsgid = (conf->root_nsgid_map != NULL) ? 0 : conf->init_gid; | |
4245 | struct lxc_list *idmap = NULL, *tmplist = NULL; | |
4246 | struct id_map *container_root_uid = NULL, *container_root_gid = NULL, | |
4247 | *host_uid_map = NULL, *host_gid_map = NULL; | |
4248 | ||
4249 | /* Find container root mappings. */ | |
4250 | container_root_uid = mapped_nsid_add(conf, nsuid, ID_TYPE_UID); | |
4251 | if (!container_root_uid) { | |
4252 | DEBUG("Failed to find mapping for namespace uid %d", 0); | |
4253 | goto on_error; | |
4254 | } | |
4255 | euid = geteuid(); | |
4256 | if (euid >= container_root_uid->hostid && | |
4257 | euid < (container_root_uid->hostid + container_root_uid->range)) | |
4258 | host_uid_map = container_root_uid; | |
4259 | ||
4260 | container_root_gid = mapped_nsid_add(conf, nsgid, ID_TYPE_GID); | |
4261 | if (!container_root_gid) { | |
4262 | DEBUG("Failed to find mapping for namespace gid %d", 0); | |
4263 | goto on_error; | |
4264 | } | |
4265 | egid = getegid(); | |
4266 | if (egid >= container_root_gid->hostid && | |
4267 | egid < (container_root_gid->hostid + container_root_gid->range)) | |
4268 | host_gid_map = container_root_gid; | |
4269 | ||
4270 | /* Check whether the {g,u}id of the user has a mapping. */ | |
4271 | if (!host_uid_map) | |
4272 | host_uid_map = mapped_hostid_add(conf, euid, ID_TYPE_UID); | |
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 | host_gid_map = mapped_hostid_add(conf, egid, ID_TYPE_GID); | |
4280 | if (!host_gid_map) { | |
4281 | DEBUG("Failed to find mapping for gid %d", egid); | |
4282 | goto on_error; | |
4283 | } | |
4284 | ||
4285 | /* Allocate new {g,u}id map list. */ | |
4286 | idmap = malloc(sizeof(*idmap)); | |
4287 | if (!idmap) | |
4288 | goto on_error; | |
4289 | lxc_list_init(idmap); | |
4290 | ||
4291 | /* Add container root to the map. */ | |
4292 | tmplist = malloc(sizeof(*tmplist)); | |
4293 | if (!tmplist) | |
4294 | goto on_error; | |
4295 | lxc_list_add_elem(tmplist, container_root_uid); | |
4296 | lxc_list_add_tail(idmap, tmplist); | |
4297 | ||
4298 | if (host_uid_map && (host_uid_map != container_root_uid)) { | |
4299 | /* idmap will now keep track of that memory. */ | |
4300 | container_root_uid = NULL; | |
4301 | ||
4302 | /* Add container root to the map. */ | |
4303 | tmplist = malloc(sizeof(*tmplist)); | |
4304 | if (!tmplist) | |
4305 | goto on_error; | |
4306 | lxc_list_add_elem(tmplist, host_uid_map); | |
4307 | lxc_list_add_tail(idmap, tmplist); | |
4308 | } | |
4309 | /* idmap will now keep track of that memory. */ | |
4310 | container_root_uid = NULL; | |
4311 | /* idmap will now keep track of that memory. */ | |
4312 | host_uid_map = NULL; | |
4313 | ||
4314 | tmplist = malloc(sizeof(*tmplist)); | |
4315 | if (!tmplist) | |
4316 | goto on_error; | |
4317 | lxc_list_add_elem(tmplist, container_root_gid); | |
4318 | lxc_list_add_tail(idmap, tmplist); | |
4319 | ||
4320 | if (host_gid_map && (host_gid_map != container_root_gid)) { | |
4321 | /* idmap will now keep track of that memory. */ | |
4322 | container_root_gid = NULL; | |
4323 | ||
4324 | tmplist = malloc(sizeof(*tmplist)); | |
4325 | if (!tmplist) | |
4326 | goto on_error; | |
4327 | lxc_list_add_elem(tmplist, host_gid_map); | |
4328 | lxc_list_add_tail(idmap, tmplist); | |
4329 | } | |
4330 | /* idmap will now keep track of that memory. */ | |
4331 | container_root_gid = NULL; | |
4332 | /* idmap will now keep track of that memory. */ | |
4333 | host_gid_map = NULL; | |
4334 | ||
4335 | TRACE("Allocated minimal idmapping"); | |
4336 | return idmap; | |
4337 | ||
4338 | on_error: | |
4339 | if (idmap) { | |
4340 | lxc_free_idmap(idmap); | |
4341 | free(idmap); | |
4342 | } | |
4343 | if (container_root_uid) | |
4344 | free(container_root_uid); | |
4345 | if (container_root_gid) | |
4346 | free(container_root_gid); | |
4347 | if (host_uid_map && (host_uid_map != container_root_uid)) | |
4348 | free(host_uid_map); | |
4349 | if (host_gid_map && (host_gid_map != container_root_gid)) | |
4350 | free(host_gid_map); | |
4351 | ||
4352 | return NULL; | |
4353 | } | |
4354 | ||
4355 | /* Run a function in a new user namespace. | |
4356 | * The caller's euid/egid will be mapped if it is not already. | |
4357 | * Afaict, userns_exec_1() is only used to operate based on privileges for the | |
4358 | * user's own {g,u}id on the host and for the container root's unmapped {g,u}id. | |
4359 | * This means we require only to establish a mapping from: | |
4360 | * - the container root {g,u}id as seen from the host > user's host {g,u}id | |
4361 | * - the container root -> some sub{g,u}id | |
4362 | * The former we add, if the user did not specifiy a mapping. The latter we | |
4363 | * retrieve from the container's configured {g,u}id mappings as it must have been | |
4364 | * there to start the container in the first place. | |
4365 | */ | |
4366 | int userns_exec_1(struct lxc_conf *conf, int (*fn)(void *), void *data, | |
4367 | const char *fn_name) | |
4368 | { | |
4369 | pid_t pid; | |
4370 | int p[2]; | |
4371 | struct userns_fn_data d; | |
4372 | struct lxc_list *idmap; | |
4373 | int ret = -1, status = -1; | |
4374 | char c = '1'; | |
4375 | ||
4376 | if (!conf) | |
4377 | return -EINVAL; | |
4378 | ||
4379 | idmap = get_minimal_idmap(conf); | |
4380 | if (!idmap) | |
4381 | return -1; | |
4382 | ||
4383 | ret = pipe2(p, O_CLOEXEC); | |
4384 | if (ret < 0) { | |
4385 | SYSERROR("Failed to create pipe"); | |
4386 | return -1; | |
4387 | } | |
4388 | d.fn = fn; | |
4389 | d.fn_name = fn_name; | |
4390 | d.arg = data; | |
4391 | d.p[0] = p[0]; | |
4392 | d.p[1] = p[1]; | |
4393 | ||
4394 | /* Clone child in new user namespace. */ | |
4395 | pid = lxc_raw_clone_cb(run_userns_fn, &d, CLONE_NEWUSER); | |
4396 | if (pid < 0) { | |
4397 | ERROR("Failed to clone process in new user namespace"); | |
4398 | goto on_error; | |
4399 | } | |
4400 | ||
4401 | close(p[0]); | |
4402 | p[0] = -1; | |
4403 | ||
4404 | if (lxc_log_get_level() == LXC_LOG_LEVEL_TRACE || | |
4405 | conf->loglevel == LXC_LOG_LEVEL_TRACE) { | |
4406 | struct id_map *map; | |
4407 | struct lxc_list *it; | |
4408 | ||
4409 | lxc_list_for_each (it, idmap) { | |
4410 | map = it->elem; | |
4411 | TRACE("Establishing %cid mapping for \"%d\" in new " | |
4412 | "user namespace: nsuid %lu - hostid %lu - range " | |
4413 | "%lu", | |
4414 | (map->idtype == ID_TYPE_UID) ? 'u' : 'g', pid, | |
4415 | map->nsid, map->hostid, map->range); | |
4416 | } | |
4417 | } | |
4418 | ||
4419 | /* Set up {g,u}id mapping for user namespace of child process. */ | |
4420 | ret = lxc_map_ids(idmap, pid); | |
4421 | if (ret < 0) { | |
4422 | ERROR("Error setting up {g,u}id mappings for child process \"%d\"", pid); | |
4423 | goto on_error; | |
4424 | } | |
4425 | ||
4426 | /* Tell child to proceed. */ | |
4427 | if (lxc_write_nointr(p[1], &c, 1) != 1) { | |
4428 | SYSERROR("Failed telling child process \"%d\" to proceed", pid); | |
4429 | goto on_error; | |
4430 | } | |
4431 | ||
4432 | on_error: | |
4433 | if (p[0] != -1) | |
4434 | close(p[0]); | |
4435 | close(p[1]); | |
4436 | ||
4437 | /* Wait for child to finish. */ | |
4438 | if (pid > 0) | |
4439 | status = wait_for_pid(pid); | |
4440 | ||
4441 | if (status < 0) | |
4442 | ret = -1; | |
4443 | ||
4444 | return ret; | |
4445 | } | |
4446 | ||
4447 | int userns_exec_full(struct lxc_conf *conf, int (*fn)(void *), void *data, | |
4448 | const char *fn_name) | |
4449 | { | |
4450 | pid_t pid; | |
4451 | uid_t euid, egid; | |
4452 | int p[2]; | |
4453 | struct id_map *map; | |
4454 | struct lxc_list *cur; | |
4455 | struct userns_fn_data d; | |
4456 | int ret = -1; | |
4457 | char c = '1'; | |
4458 | struct lxc_list *idmap = NULL, *tmplist = NULL; | |
4459 | struct id_map *container_root_uid = NULL, *container_root_gid = NULL, | |
4460 | *host_uid_map = NULL, *host_gid_map = NULL; | |
4461 | ||
4462 | if (!conf) | |
4463 | return -EINVAL; | |
4464 | ||
4465 | ret = pipe2(p, O_CLOEXEC); | |
4466 | if (ret < 0) { | |
4467 | SYSERROR("opening pipe"); | |
4468 | return -1; | |
4469 | } | |
4470 | d.fn = fn; | |
4471 | d.fn_name = fn_name; | |
4472 | d.arg = data; | |
4473 | d.p[0] = p[0]; | |
4474 | d.p[1] = p[1]; | |
4475 | ||
4476 | /* Clone child in new user namespace. */ | |
4477 | pid = lxc_clone(run_userns_fn, &d, CLONE_NEWUSER); | |
4478 | if (pid < 0) { | |
4479 | ERROR("Failed to clone process in new user namespace"); | |
4480 | goto on_error; | |
4481 | } | |
4482 | ||
4483 | close(p[0]); | |
4484 | p[0] = -1; | |
4485 | ||
4486 | euid = geteuid(); | |
4487 | egid = getegid(); | |
4488 | ||
4489 | /* Allocate new {g,u}id map list. */ | |
4490 | idmap = malloc(sizeof(*idmap)); | |
4491 | if (!idmap) | |
4492 | goto on_error; | |
4493 | lxc_list_init(idmap); | |
4494 | ||
4495 | /* Find container root. */ | |
4496 | lxc_list_for_each (cur, &conf->id_map) { | |
4497 | struct id_map *tmpmap; | |
4498 | ||
4499 | tmplist = malloc(sizeof(*tmplist)); | |
4500 | if (!tmplist) | |
4501 | goto on_error; | |
4502 | ||
4503 | tmpmap = malloc(sizeof(*tmpmap)); | |
4504 | if (!tmpmap) { | |
4505 | free(tmplist); | |
4506 | goto on_error; | |
4507 | } | |
4508 | ||
4509 | memset(tmpmap, 0, sizeof(*tmpmap)); | |
4510 | memcpy(tmpmap, cur->elem, sizeof(*tmpmap)); | |
4511 | tmplist->elem = tmpmap; | |
4512 | ||
4513 | lxc_list_add_tail(idmap, tmplist); | |
4514 | ||
4515 | map = cur->elem; | |
4516 | ||
4517 | if (map->idtype == ID_TYPE_UID) | |
4518 | if (euid >= map->hostid && euid < map->hostid + map->range) | |
4519 | host_uid_map = map; | |
4520 | ||
4521 | if (map->idtype == ID_TYPE_GID) | |
4522 | if (egid >= map->hostid && egid < map->hostid + map->range) | |
4523 | host_gid_map = map; | |
4524 | ||
4525 | if (map->nsid != 0) | |
4526 | continue; | |
4527 | ||
4528 | if (map->idtype == ID_TYPE_UID) | |
4529 | if (container_root_uid == NULL) | |
4530 | container_root_uid = map; | |
4531 | ||
4532 | if (map->idtype == ID_TYPE_GID) | |
4533 | if (container_root_gid == NULL) | |
4534 | container_root_gid = map; | |
4535 | } | |
4536 | ||
4537 | if (!container_root_uid || !container_root_gid) { | |
4538 | ERROR("No mapping for container root found"); | |
4539 | goto on_error; | |
4540 | } | |
4541 | ||
4542 | /* Check whether the {g,u}id of the user has a mapping. */ | |
4543 | if (!host_uid_map) | |
4544 | host_uid_map = mapped_hostid_add(conf, euid, ID_TYPE_UID); | |
4545 | else | |
4546 | host_uid_map = container_root_uid; | |
4547 | ||
4548 | if (!host_gid_map) | |
4549 | host_gid_map = mapped_hostid_add(conf, egid, ID_TYPE_GID); | |
4550 | else | |
4551 | host_gid_map = container_root_gid; | |
4552 | ||
4553 | if (!host_uid_map) { | |
4554 | DEBUG("Failed to find mapping for uid %d", euid); | |
4555 | goto on_error; | |
4556 | } | |
4557 | ||
4558 | if (!host_gid_map) { | |
4559 | DEBUG("Failed to find mapping for gid %d", egid); | |
4560 | goto on_error; | |
4561 | } | |
4562 | ||
4563 | if (host_uid_map && (host_uid_map != container_root_uid)) { | |
4564 | /* Add container root to the map. */ | |
4565 | tmplist = malloc(sizeof(*tmplist)); | |
4566 | if (!tmplist) | |
4567 | goto on_error; | |
4568 | lxc_list_add_elem(tmplist, host_uid_map); | |
4569 | lxc_list_add_tail(idmap, tmplist); | |
4570 | } | |
4571 | /* idmap will now keep track of that memory. */ | |
4572 | host_uid_map = NULL; | |
4573 | ||
4574 | if (host_gid_map && (host_gid_map != container_root_gid)) { | |
4575 | tmplist = malloc(sizeof(*tmplist)); | |
4576 | if (!tmplist) | |
4577 | goto on_error; | |
4578 | lxc_list_add_elem(tmplist, host_gid_map); | |
4579 | lxc_list_add_tail(idmap, tmplist); | |
4580 | } | |
4581 | /* idmap will now keep track of that memory. */ | |
4582 | host_gid_map = NULL; | |
4583 | ||
4584 | if (lxc_log_get_level() == LXC_LOG_LEVEL_TRACE || | |
4585 | conf->loglevel == LXC_LOG_LEVEL_TRACE) { | |
4586 | lxc_list_for_each (cur, idmap) { | |
4587 | map = cur->elem; | |
4588 | TRACE("establishing %cid mapping for \"%d\" in new " | |
4589 | "user namespace: nsuid %lu - hostid %lu - range " | |
4590 | "%lu", | |
4591 | (map->idtype == ID_TYPE_UID) ? 'u' : 'g', pid, | |
4592 | map->nsid, map->hostid, map->range); | |
4593 | } | |
4594 | } | |
4595 | ||
4596 | /* Set up {g,u}id mapping for user namespace of child process. */ | |
4597 | ret = lxc_map_ids(idmap, pid); | |
4598 | if (ret < 0) { | |
4599 | ERROR("error setting up {g,u}id mappings for child process \"%d\"", pid); | |
4600 | goto on_error; | |
4601 | } | |
4602 | ||
4603 | /* Tell child to proceed. */ | |
4604 | if (lxc_write_nointr(p[1], &c, 1) != 1) { | |
4605 | SYSERROR("Failed telling child process \"%d\" to proceed", pid); | |
4606 | goto on_error; | |
4607 | } | |
4608 | ||
4609 | on_error: | |
4610 | if (p[0] != -1) | |
4611 | close(p[0]); | |
4612 | close(p[1]); | |
4613 | ||
4614 | /* Wait for child to finish. */ | |
4615 | if (pid > 0) | |
4616 | ret = wait_for_pid(pid); | |
4617 | ||
4618 | if (idmap) { | |
4619 | lxc_free_idmap(idmap); | |
4620 | free(idmap); | |
4621 | } | |
4622 | ||
4623 | if (host_uid_map && (host_uid_map != container_root_uid)) | |
4624 | free(host_uid_map); | |
4625 | if (host_gid_map && (host_gid_map != container_root_gid)) | |
4626 | free(host_gid_map); | |
4627 | ||
4628 | return ret; | |
4629 | } | |
4630 | ||
4631 | /* not thread-safe, do not use from api without first forking */ | |
4632 | static char *getuname(void) | |
4633 | { | |
4634 | struct passwd pwent; | |
4635 | struct passwd *pwentp = NULL; | |
4636 | char *buf; | |
4637 | char *username; | |
4638 | size_t bufsize; | |
4639 | int ret; | |
4640 | ||
4641 | bufsize = sysconf(_SC_GETPW_R_SIZE_MAX); | |
4642 | if (bufsize == -1) | |
4643 | bufsize = 1024; | |
4644 | ||
4645 | buf = malloc(bufsize); | |
4646 | if (!buf) | |
4647 | return NULL; | |
4648 | ||
4649 | ret = getpwuid_r(geteuid(), &pwent, buf, bufsize, &pwentp); | |
4650 | if (!pwentp) { | |
4651 | if (ret == 0) | |
4652 | WARN("Could not find matched password record."); | |
4653 | ||
4654 | ERROR("Failed to get password record - %u", geteuid()); | |
4655 | free(buf); | |
4656 | return NULL; | |
4657 | } | |
4658 | ||
4659 | username = strdup(pwent.pw_name); | |
4660 | free(buf); | |
4661 | ||
4662 | return username; | |
4663 | } | |
4664 | ||
4665 | /* not thread-safe, do not use from api without first forking */ | |
4666 | static char *getgname(void) | |
4667 | { | |
4668 | struct group grent; | |
4669 | struct group *grentp = NULL; | |
4670 | char *buf; | |
4671 | char *grname; | |
4672 | size_t bufsize; | |
4673 | int ret; | |
4674 | ||
4675 | bufsize = sysconf(_SC_GETGR_R_SIZE_MAX); | |
4676 | if (bufsize == -1) | |
4677 | bufsize = 1024; | |
4678 | ||
4679 | buf = malloc(bufsize); | |
4680 | if (!buf) | |
4681 | return NULL; | |
4682 | ||
4683 | ret = getgrgid_r(getegid(), &grent, buf, bufsize, &grentp); | |
4684 | if (!grentp) { | |
4685 | if (ret == 0) | |
4686 | WARN("Could not find matched group record"); | |
4687 | ||
4688 | ERROR("Failed to get group record - %u", getegid()); | |
4689 | free(buf); | |
4690 | return NULL; | |
4691 | } | |
4692 | ||
4693 | grname = strdup(grent.gr_name); | |
4694 | free(buf); | |
4695 | ||
4696 | return grname; | |
4697 | } | |
4698 | ||
4699 | /* not thread-safe, do not use from api without first forking */ | |
4700 | void suggest_default_idmap(void) | |
4701 | { | |
4702 | char *uname, *gname; | |
4703 | FILE *f; | |
4704 | unsigned int uid = 0, urange = 0, gid = 0, grange = 0; | |
4705 | size_t len = 0; | |
4706 | char *line = NULL; | |
4707 | ||
4708 | uname = getuname(); | |
4709 | if (!uname) | |
4710 | return; | |
4711 | ||
4712 | gname = getgname(); | |
4713 | if (!gname) { | |
4714 | free(uname); | |
4715 | return; | |
4716 | } | |
4717 | ||
4718 | f = fopen(subuidfile, "r"); | |
4719 | if (!f) { | |
4720 | ERROR("Your system is not configured with subuids"); | |
4721 | free(gname); | |
4722 | free(uname); | |
4723 | return; | |
4724 | } | |
4725 | ||
4726 | while (getline(&line, &len, f) != -1) { | |
4727 | char *p, *p2; | |
4728 | size_t no_newline = 0; | |
4729 | ||
4730 | p = strchr(line, ':'); | |
4731 | if (*line == '#') | |
4732 | continue; | |
4733 | if (!p) | |
4734 | continue; | |
4735 | *p = '\0'; | |
4736 | p++; | |
4737 | ||
4738 | if (strcmp(line, uname)) | |
4739 | continue; | |
4740 | ||
4741 | p2 = strchr(p, ':'); | |
4742 | if (!p2) | |
4743 | continue; | |
4744 | *p2 = '\0'; | |
4745 | p2++; | |
4746 | if (!*p2) | |
4747 | continue; | |
4748 | no_newline = strcspn(p2, "\n"); | |
4749 | p2[no_newline] = '\0'; | |
4750 | ||
4751 | if (lxc_safe_uint(p, &uid) < 0) | |
4752 | WARN("Could not parse UID"); | |
4753 | if (lxc_safe_uint(p2, &urange) < 0) | |
4754 | WARN("Could not parse UID range"); | |
4755 | } | |
4756 | fclose(f); | |
4757 | ||
4758 | f = fopen(subgidfile, "r"); | |
4759 | if (!f) { | |
4760 | ERROR("Your system is not configured with subgids"); | |
4761 | free(gname); | |
4762 | free(uname); | |
4763 | return; | |
4764 | } | |
4765 | ||
4766 | while (getline(&line, &len, f) != -1) { | |
4767 | char *p, *p2; | |
4768 | size_t no_newline = 0; | |
4769 | ||
4770 | p = strchr(line, ':'); | |
4771 | if (*line == '#') | |
4772 | continue; | |
4773 | if (!p) | |
4774 | continue; | |
4775 | *p = '\0'; | |
4776 | p++; | |
4777 | ||
4778 | if (strcmp(line, uname)) | |
4779 | continue; | |
4780 | ||
4781 | p2 = strchr(p, ':'); | |
4782 | if (!p2) | |
4783 | continue; | |
4784 | *p2 = '\0'; | |
4785 | p2++; | |
4786 | if (!*p2) | |
4787 | continue; | |
4788 | no_newline = strcspn(p2, "\n"); | |
4789 | p2[no_newline] = '\0'; | |
4790 | ||
4791 | if (lxc_safe_uint(p, &gid) < 0) | |
4792 | WARN("Could not parse GID"); | |
4793 | if (lxc_safe_uint(p2, &grange) < 0) | |
4794 | WARN("Could not parse GID range"); | |
4795 | } | |
4796 | fclose(f); | |
4797 | ||
4798 | free(line); | |
4799 | ||
4800 | if (!urange || !grange) { | |
4801 | ERROR("You do not have subuids or subgids allocated"); | |
4802 | ERROR("Unprivileged containers require subuids and subgids"); | |
4803 | free(uname); | |
4804 | free(gname); | |
4805 | return; | |
4806 | } | |
4807 | ||
4808 | ERROR("You must either run as root, or define uid mappings"); | |
4809 | ERROR("To pass uid mappings to lxc-create, you could create"); | |
4810 | ERROR("~/.config/lxc/default.conf:"); | |
4811 | ERROR("lxc.include = %s", LXC_DEFAULT_CONFIG); | |
4812 | ERROR("lxc.idmap = u 0 %u %u", uid, urange); | |
4813 | ERROR("lxc.idmap = g 0 %u %u", gid, grange); | |
4814 | ||
4815 | free(gname); | |
4816 | free(uname); | |
4817 | } | |
4818 | ||
4819 | static void free_cgroup_settings(struct lxc_list *result) | |
4820 | { | |
4821 | struct lxc_list *iterator, *next; | |
4822 | ||
4823 | lxc_list_for_each_safe (iterator, result, next) { | |
4824 | lxc_list_del(iterator); | |
4825 | free(iterator); | |
4826 | } | |
4827 | free(result); | |
4828 | } | |
4829 | ||
4830 | /* Return the list of cgroup_settings sorted according to the following rules | |
4831 | * 1. Put memory.limit_in_bytes before memory.memsw.limit_in_bytes | |
4832 | */ | |
4833 | struct lxc_list *sort_cgroup_settings(struct lxc_list *cgroup_settings) | |
4834 | { | |
4835 | struct lxc_list *result; | |
4836 | struct lxc_cgroup *cg = NULL; | |
4837 | struct lxc_list *it = NULL, *item = NULL, *memsw_limit = NULL; | |
4838 | ||
4839 | result = malloc(sizeof(*result)); | |
4840 | if (!result) | |
4841 | return NULL; | |
4842 | lxc_list_init(result); | |
4843 | ||
4844 | /* Iterate over the cgroup settings and copy them to the output list. */ | |
4845 | lxc_list_for_each (it, cgroup_settings) { | |
4846 | item = malloc(sizeof(*item)); | |
4847 | if (!item) { | |
4848 | free_cgroup_settings(result); | |
4849 | return NULL; | |
4850 | } | |
4851 | ||
4852 | item->elem = it->elem; | |
4853 | cg = it->elem; | |
4854 | if (strcmp(cg->subsystem, "memory.memsw.limit_in_bytes") == 0) { | |
4855 | /* Store the memsw_limit location */ | |
4856 | memsw_limit = item; | |
4857 | } else if (strcmp(cg->subsystem, "memory.limit_in_bytes") == 0 && | |
4858 | memsw_limit != NULL) { | |
4859 | /* lxc.cgroup.memory.memsw.limit_in_bytes is found | |
4860 | * before lxc.cgroup.memory.limit_in_bytes, swap these | |
4861 | * two items */ | |
4862 | item->elem = memsw_limit->elem; | |
4863 | memsw_limit->elem = it->elem; | |
4864 | } | |
4865 | lxc_list_add_tail(result, item); | |
4866 | } | |
4867 | ||
4868 | return result; | |
4869 | } |