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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 | * Serge Hallyn <serge@hallyn.com> | |
9 | * Christian Brauner <christian.brauner@ubuntu.com> | |
10 | * | |
11 | * This library is free software; you can redistribute it and/or | |
12 | * modify it under the terms of the GNU Lesser General Public | |
13 | * License as published by the Free Software Foundation; either | |
14 | * version 2.1 of the License, or (at your option) any later version. | |
15 | * | |
16 | * This library is distributed in the hope that it will be useful, | |
17 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
18 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
19 | * Lesser General Public License for more details. | |
20 | * | |
21 | * You should have received a copy of the GNU Lesser General Public | |
22 | * License along with this library; if not, write to the Free Software | |
23 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
24 | */ | |
25 | ||
26 | #define _GNU_SOURCE | |
27 | #include "config.h" | |
28 | ||
29 | #include <alloca.h> | |
30 | #include <dirent.h> | |
31 | #include <errno.h> | |
32 | #include <fcntl.h> | |
33 | #include <grp.h> | |
34 | #include <poll.h> | |
35 | #include <signal.h> | |
36 | #include <stdio.h> | |
37 | #include <stdlib.h> | |
38 | #include <string.h> | |
39 | #include <unistd.h> | |
40 | #include <sys/file.h> | |
41 | #include <sys/mount.h> | |
42 | #include <sys/param.h> | |
43 | #include <sys/prctl.h> | |
44 | #include <sys/socket.h> | |
45 | #include <sys/stat.h> | |
46 | #include <sys/syscall.h> | |
47 | #include <sys/types.h> | |
48 | #include <sys/un.h> | |
49 | #include <sys/wait.h> | |
50 | ||
51 | #if HAVE_LIBCAP | |
52 | #include <sys/capability.h> | |
53 | #endif | |
54 | ||
55 | #if !HAVE_DECL_PR_CAPBSET_DROP | |
56 | #define PR_CAPBSET_DROP 24 | |
57 | #endif | |
58 | ||
59 | #if !HAVE_DECL_PR_SET_NO_NEW_PRIVS | |
60 | #define PR_SET_NO_NEW_PRIVS 38 | |
61 | #endif | |
62 | ||
63 | #if !HAVE_DECL_PR_GET_NO_NEW_PRIVS | |
64 | #define PR_GET_NO_NEW_PRIVS 39 | |
65 | #endif | |
66 | ||
67 | #include "af_unix.h" | |
68 | #include "caps.h" | |
69 | #include "cgroup.h" | |
70 | #include "commands.h" | |
71 | #include "commands_utils.h" | |
72 | #include "conf.h" | |
73 | #include "confile_utils.h" | |
74 | #include "console.h" | |
75 | #include "error.h" | |
76 | #include "log.h" | |
77 | #include "lxccontainer.h" | |
78 | #include "lxclock.h" | |
79 | #include "lxcseccomp.h" | |
80 | #include "mainloop.h" | |
81 | #include "monitor.h" | |
82 | #include "namespace.h" | |
83 | #include "network.h" | |
84 | #include "start.h" | |
85 | #include "storage.h" | |
86 | #include "storage_utils.h" | |
87 | #include "sync.h" | |
88 | #include "utils.h" | |
89 | #include "lsm/lsm.h" | |
90 | ||
91 | lxc_log_define(lxc_start, lxc); | |
92 | ||
93 | extern void mod_all_rdeps(struct lxc_container *c, bool inc); | |
94 | static bool do_destroy_container(struct lxc_handler *handler); | |
95 | static int lxc_rmdir_onedev_wrapper(void *data); | |
96 | static void lxc_destroy_container_on_signal(struct lxc_handler *handler, | |
97 | const char *name); | |
98 | ||
99 | static void print_top_failing_dir(const char *path) | |
100 | { | |
101 | size_t len = strlen(path); | |
102 | char *copy = alloca(len + 1), *p, *e, saved; | |
103 | strcpy(copy, path); | |
104 | ||
105 | p = copy; | |
106 | e = copy + len; | |
107 | while (p < e) { | |
108 | while (p < e && *p == '/') | |
109 | p++; | |
110 | while (p < e && *p != '/') | |
111 | p++; | |
112 | saved = *p; | |
113 | *p = '\0'; | |
114 | if (access(copy, X_OK)) { | |
115 | SYSERROR("Could not access %s. Please grant it x " | |
116 | "access, or add an ACL for the container " | |
117 | "root.", copy); | |
118 | return; | |
119 | } | |
120 | *p = saved; | |
121 | } | |
122 | } | |
123 | ||
124 | static void close_ns(int ns_fd[LXC_NS_MAX]) | |
125 | { | |
126 | int i; | |
127 | ||
128 | for (i = 0; i < LXC_NS_MAX; i++) { | |
129 | if (ns_fd[i] > -1) { | |
130 | close(ns_fd[i]); | |
131 | ns_fd[i] = -1; | |
132 | } | |
133 | } | |
134 | } | |
135 | ||
136 | /* preserve_ns: open /proc/@pid/ns/@ns for each namespace specified | |
137 | * in clone_flags. | |
138 | * Return true on success, false on failure. | |
139 | */ | |
140 | static bool preserve_ns(int ns_fd[LXC_NS_MAX], int clone_flags, pid_t pid) | |
141 | { | |
142 | int i, ret; | |
143 | ||
144 | for (i = 0; i < LXC_NS_MAX; i++) | |
145 | ns_fd[i] = -1; | |
146 | ||
147 | ret = lxc_preserve_ns(pid, ""); | |
148 | if (ret < 0) { | |
149 | SYSERROR("Kernel does not support attaching to namespaces."); | |
150 | return false; | |
151 | } else { | |
152 | close(ret); | |
153 | } | |
154 | ||
155 | for (i = 0; i < LXC_NS_MAX; i++) { | |
156 | if ((clone_flags & ns_info[i].clone_flag) == 0) | |
157 | continue; | |
158 | ||
159 | ns_fd[i] = lxc_preserve_ns(pid, ns_info[i].proc_name); | |
160 | if (ns_fd[i] < 0) | |
161 | goto error; | |
162 | ||
163 | DEBUG("Preserved %s namespace via fd %d", ns_info[i].proc_name, ns_fd[i]); | |
164 | } | |
165 | ||
166 | return true; | |
167 | ||
168 | error: | |
169 | if (errno == ENOENT) | |
170 | SYSERROR("Kernel does not support attaching to %s namespaces.", ns_info[i].proc_name); | |
171 | else | |
172 | SYSERROR("Failed to open file descriptor for %s namespace: %s.", ns_info[i].proc_name, strerror(errno)); | |
173 | close_ns(ns_fd); | |
174 | return false; | |
175 | } | |
176 | ||
177 | static int match_fd(int fd) | |
178 | { | |
179 | return (fd == 0 || fd == 1 || fd == 2); | |
180 | } | |
181 | ||
182 | int lxc_check_inherited(struct lxc_conf *conf, bool closeall, | |
183 | int *fds_to_ignore, size_t len_fds) | |
184 | { | |
185 | struct dirent *direntp; | |
186 | int fd, fddir; | |
187 | size_t i; | |
188 | DIR *dir; | |
189 | ||
190 | if (conf && conf->close_all_fds) | |
191 | closeall = true; | |
192 | ||
193 | restart: | |
194 | dir = opendir("/proc/self/fd"); | |
195 | if (!dir) { | |
196 | WARN("Failed to open directory: %s.", strerror(errno)); | |
197 | return -1; | |
198 | } | |
199 | ||
200 | fddir = dirfd(dir); | |
201 | ||
202 | while ((direntp = readdir(dir))) { | |
203 | struct lxc_list *cur; | |
204 | bool matched = false; | |
205 | ||
206 | if (!direntp) | |
207 | break; | |
208 | ||
209 | if (!strcmp(direntp->d_name, ".")) | |
210 | continue; | |
211 | ||
212 | if (!strcmp(direntp->d_name, "..")) | |
213 | continue; | |
214 | ||
215 | if (lxc_safe_int(direntp->d_name, &fd) < 0) { | |
216 | INFO("Could not parse file descriptor for: %s", direntp->d_name); | |
217 | continue; | |
218 | } | |
219 | ||
220 | for (i = 0; i < len_fds; i++) | |
221 | if (fds_to_ignore[i] == fd) | |
222 | break; | |
223 | ||
224 | if (fd == fddir || fd == lxc_log_fd || | |
225 | (i < len_fds && fd == fds_to_ignore[i])) | |
226 | continue; | |
227 | ||
228 | /* Keep state clients that wait on reboots. */ | |
229 | if (conf) { | |
230 | lxc_list_for_each(cur, &conf->state_clients) { | |
231 | struct lxc_state_client *client = cur->elem; | |
232 | ||
233 | if (client->clientfd != fd) | |
234 | continue; | |
235 | ||
236 | matched = true; | |
237 | break; | |
238 | } | |
239 | } | |
240 | ||
241 | if (matched) | |
242 | continue; | |
243 | ||
244 | if (current_config && fd == current_config->logfd) | |
245 | continue; | |
246 | ||
247 | if (match_fd(fd)) | |
248 | continue; | |
249 | ||
250 | if (closeall) { | |
251 | close(fd); | |
252 | closedir(dir); | |
253 | INFO("Closed inherited fd %d", fd); | |
254 | goto restart; | |
255 | } | |
256 | WARN("Inherited fd %d", fd); | |
257 | } | |
258 | ||
259 | /* Only enable syslog at this point to avoid the above logging function | |
260 | * to open a new fd and make the check_inherited function enter an | |
261 | * infinite loop. | |
262 | */ | |
263 | lxc_log_enable_syslog(); | |
264 | ||
265 | closedir(dir); /* cannot fail */ | |
266 | return 0; | |
267 | } | |
268 | ||
269 | static int setup_signal_fd(sigset_t *oldmask) | |
270 | { | |
271 | sigset_t mask; | |
272 | int fd; | |
273 | ||
274 | /* Block everything except serious error signals. */ | |
275 | if (sigfillset(&mask) || | |
276 | sigdelset(&mask, SIGILL) || | |
277 | sigdelset(&mask, SIGSEGV) || | |
278 | sigdelset(&mask, SIGBUS) || | |
279 | sigdelset(&mask, SIGWINCH) || | |
280 | sigprocmask(SIG_BLOCK, &mask, oldmask)) { | |
281 | SYSERROR("Failed to set signal mask."); | |
282 | return -1; | |
283 | } | |
284 | ||
285 | fd = signalfd(-1, &mask, 0); | |
286 | if (fd < 0) { | |
287 | SYSERROR("Failed to create signal file descriptor."); | |
288 | return -1; | |
289 | } | |
290 | ||
291 | if (fcntl(fd, F_SETFD, FD_CLOEXEC)) { | |
292 | SYSERROR("Failed to set FD_CLOEXEC on the signal file descriptor: %d.", fd); | |
293 | close(fd); | |
294 | return -1; | |
295 | } | |
296 | ||
297 | DEBUG("Set SIGCHLD handler with file descriptor: %d.", fd); | |
298 | ||
299 | return fd; | |
300 | } | |
301 | ||
302 | static int signal_handler(int fd, uint32_t events, void *data, | |
303 | struct lxc_epoll_descr *descr) | |
304 | { | |
305 | struct signalfd_siginfo siginfo; | |
306 | siginfo_t info; | |
307 | int ret; | |
308 | pid_t *pid = data; | |
309 | bool init_died = false; | |
310 | ||
311 | ret = read(fd, &siginfo, sizeof(siginfo)); | |
312 | if (ret < 0) { | |
313 | ERROR("Failed to read signal info from signal file descriptor: %d.", fd); | |
314 | return -1; | |
315 | } | |
316 | ||
317 | if (ret != sizeof(siginfo)) { | |
318 | ERROR("Unexpected size for siginfo struct."); | |
319 | return -1; | |
320 | } | |
321 | ||
322 | /* Check whether init is running. */ | |
323 | info.si_pid = 0; | |
324 | ret = waitid(P_PID, *pid, &info, WEXITED | WNOWAIT | WNOHANG); | |
325 | if (ret == 0 && info.si_pid == *pid) | |
326 | init_died = true; | |
327 | ||
328 | if (siginfo.ssi_signo != SIGCHLD) { | |
329 | kill(*pid, siginfo.ssi_signo); | |
330 | INFO("Forwarded signal %d to pid %d.", siginfo.ssi_signo, *pid); | |
331 | return init_died ? 1 : 0; | |
332 | } | |
333 | ||
334 | if (siginfo.ssi_code == CLD_STOPPED) { | |
335 | INFO("Container init process was stopped."); | |
336 | return init_died ? 1 : 0; | |
337 | } else if (siginfo.ssi_code == CLD_CONTINUED) { | |
338 | INFO("Container init process was continued."); | |
339 | return init_died ? 1 : 0; | |
340 | } | |
341 | ||
342 | /* More robustness, protect ourself from a SIGCHLD sent | |
343 | * by a process different from the container init. | |
344 | */ | |
345 | if (siginfo.ssi_pid != *pid) { | |
346 | NOTICE("Received SIGCHLD from pid %d instead of container init %d.", siginfo.ssi_pid, *pid); | |
347 | return init_died ? 1 : 0; | |
348 | } | |
349 | ||
350 | DEBUG("Container init process %d exited.", *pid); | |
351 | return 1; | |
352 | } | |
353 | ||
354 | static int lxc_serve_state_clients(const char *name, | |
355 | struct lxc_handler *handler, | |
356 | lxc_state_t state) | |
357 | { | |
358 | ssize_t ret; | |
359 | struct lxc_list *cur, *next; | |
360 | struct lxc_state_client *client; | |
361 | struct lxc_msg msg = {.type = lxc_msg_state, .value = state}; | |
362 | ||
363 | process_lock(); | |
364 | handler->state = state; | |
365 | TRACE("Set container state to %s", lxc_state2str(state)); | |
366 | ||
367 | if (lxc_list_empty(&handler->conf->state_clients)) { | |
368 | TRACE("No state clients registered"); | |
369 | process_unlock(); | |
370 | lxc_monitor_send_state(name, state, handler->lxcpath); | |
371 | return 0; | |
372 | } | |
373 | ||
374 | strncpy(msg.name, name, sizeof(msg.name)); | |
375 | msg.name[sizeof(msg.name) - 1] = 0; | |
376 | ||
377 | lxc_list_for_each_safe(cur, &handler->conf->state_clients, next) { | |
378 | client = cur->elem; | |
379 | ||
380 | if (client->states[state] == 0) { | |
381 | TRACE("State %s not registered for state client %d", | |
382 | lxc_state2str(state), client->clientfd); | |
383 | continue; | |
384 | } | |
385 | ||
386 | TRACE("Sending state %s to state client %d", | |
387 | lxc_state2str(state), client->clientfd); | |
388 | ||
389 | again: | |
390 | ret = send(client->clientfd, &msg, sizeof(msg), 0); | |
391 | if (ret <= 0) { | |
392 | if (errno == EINTR) { | |
393 | TRACE("Caught EINTR; retrying"); | |
394 | goto again; | |
395 | } | |
396 | ||
397 | ERROR("%s - Failed to send message to client", | |
398 | strerror(errno)); | |
399 | } | |
400 | ||
401 | /* kick client from list */ | |
402 | close(client->clientfd); | |
403 | lxc_list_del(cur); | |
404 | free(cur->elem); | |
405 | free(cur); | |
406 | } | |
407 | process_unlock(); | |
408 | ||
409 | return 0; | |
410 | } | |
411 | ||
412 | static int lxc_serve_state_socket_pair(const char *name, | |
413 | struct lxc_handler *handler, | |
414 | lxc_state_t state) | |
415 | { | |
416 | ssize_t ret; | |
417 | ||
418 | if (!handler->backgrounded || | |
419 | handler->state_socket_pair[1] < 0 || | |
420 | state == STARTING) | |
421 | return 0; | |
422 | ||
423 | /* Close read end of the socket pair. */ | |
424 | close(handler->state_socket_pair[0]); | |
425 | handler->state_socket_pair[0] = -1; | |
426 | ||
427 | again: | |
428 | ret = lxc_abstract_unix_send_credential(handler->state_socket_pair[1], | |
429 | &(int){state}, sizeof(int)); | |
430 | if (ret != sizeof(int)) { | |
431 | if (errno == EINTR) | |
432 | goto again; | |
433 | SYSERROR("Failed to send state to %d", | |
434 | handler->state_socket_pair[1]); | |
435 | return -1; | |
436 | } | |
437 | ||
438 | TRACE("Sent container state \"%s\" to %d", lxc_state2str(state), | |
439 | handler->state_socket_pair[1]); | |
440 | ||
441 | /* Close write end of the socket pair. */ | |
442 | close(handler->state_socket_pair[1]); | |
443 | handler->state_socket_pair[1] = -1; | |
444 | ||
445 | return 0; | |
446 | } | |
447 | ||
448 | int lxc_set_state(const char *name, struct lxc_handler *handler, | |
449 | lxc_state_t state) | |
450 | { | |
451 | int ret; | |
452 | ||
453 | ret = lxc_serve_state_socket_pair(name, handler, state); | |
454 | if (ret < 0) { | |
455 | ERROR("Failed to synchronize via anonymous pair of unix sockets"); | |
456 | return -1; | |
457 | } | |
458 | ||
459 | ret = lxc_serve_state_clients(name, handler, state); | |
460 | if (ret < 0) | |
461 | return -1; | |
462 | ||
463 | /* This function will try to connect to the legacy lxc-monitord state | |
464 | * server and only exists for backwards compatibility. | |
465 | */ | |
466 | lxc_monitor_send_state(name, state, handler->lxcpath); | |
467 | ||
468 | return 0; | |
469 | } | |
470 | ||
471 | int lxc_poll(const char *name, struct lxc_handler *handler) | |
472 | { | |
473 | int sigfd = handler->sigfd; | |
474 | int pid = handler->pid; | |
475 | struct lxc_epoll_descr descr; | |
476 | ||
477 | if (lxc_mainloop_open(&descr)) { | |
478 | ERROR("Failed to create LXC mainloop."); | |
479 | goto out_sigfd; | |
480 | } | |
481 | ||
482 | if (lxc_mainloop_add_handler(&descr, sigfd, signal_handler, &pid)) { | |
483 | ERROR("Failed to add signal handler with file descriptor %d to LXC mainloop.", sigfd); | |
484 | goto out_mainloop_open; | |
485 | } | |
486 | ||
487 | if (lxc_console_mainloop_add(&descr, handler->conf)) { | |
488 | ERROR("Failed to add console handler to LXC mainloop."); | |
489 | goto out_mainloop_open; | |
490 | } | |
491 | ||
492 | if (lxc_cmd_mainloop_add(name, &descr, handler)) { | |
493 | ERROR("Failed to add command handler to LXC mainloop."); | |
494 | goto out_mainloop_open; | |
495 | } | |
496 | ||
497 | TRACE("lxc mainloop is ready"); | |
498 | ||
499 | return lxc_mainloop(&descr, -1); | |
500 | ||
501 | out_mainloop_open: | |
502 | lxc_mainloop_close(&descr); | |
503 | ||
504 | out_sigfd: | |
505 | close(sigfd); | |
506 | ||
507 | return -1; | |
508 | } | |
509 | ||
510 | void lxc_free_handler(struct lxc_handler *handler) | |
511 | { | |
512 | if (handler->conf && handler->conf->maincmd_fd) | |
513 | close(handler->conf->maincmd_fd); | |
514 | ||
515 | if (handler->state_socket_pair[0] >= 0) | |
516 | close(handler->state_socket_pair[0]); | |
517 | ||
518 | if (handler->state_socket_pair[1] >= 0) | |
519 | close(handler->state_socket_pair[1]); | |
520 | ||
521 | handler->conf = NULL; | |
522 | free(handler); | |
523 | } | |
524 | ||
525 | struct lxc_handler *lxc_init_handler(const char *name, struct lxc_conf *conf, | |
526 | const char *lxcpath, bool daemonize) | |
527 | { | |
528 | int i, ret; | |
529 | struct lxc_handler *handler; | |
530 | ||
531 | handler = malloc(sizeof(*handler)); | |
532 | if (!handler) { | |
533 | ERROR("failed to allocate memory"); | |
534 | return NULL; | |
535 | } | |
536 | ||
537 | memset(handler, 0, sizeof(*handler)); | |
538 | ||
539 | /* Note that am_unpriv() checks the effective uid. We probably don't | |
540 | * care if we are real root only if we are running as root so this | |
541 | * should be fine. | |
542 | */ | |
543 | handler->am_root = !am_unpriv(); | |
544 | handler->data_sock[0] = handler->data_sock[1] = -1; | |
545 | handler->conf = conf; | |
546 | handler->lxcpath = lxcpath; | |
547 | handler->pinfd = -1; | |
548 | handler->state_socket_pair[0] = handler->state_socket_pair[1] = -1; | |
549 | if (handler->conf->reboot == 0) | |
550 | lxc_list_init(&handler->conf->state_clients); | |
551 | ||
552 | for (i = 0; i < LXC_NS_MAX; i++) | |
553 | handler->nsfd[i] = -1; | |
554 | ||
555 | handler->name = name; | |
556 | ||
557 | if (daemonize && !handler->conf->reboot) { | |
558 | /* Create socketpair() to synchronize on daemonized startup. | |
559 | * When the container reboots we don't need to synchronize again | |
560 | * currently so don't open another socketpair(). | |
561 | */ | |
562 | ret = socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0, | |
563 | handler->state_socket_pair); | |
564 | if (ret < 0) { | |
565 | ERROR("Failed to create anonymous pair of unix sockets"); | |
566 | goto on_error; | |
567 | } | |
568 | TRACE("Created anonymous pair {%d,%d} of unix sockets", | |
569 | handler->state_socket_pair[0], | |
570 | handler->state_socket_pair[1]); | |
571 | } | |
572 | ||
573 | if (handler->conf->reboot == 0) { | |
574 | handler->conf->maincmd_fd = lxc_cmd_init(name, lxcpath, "command"); | |
575 | if (handler->conf->maincmd_fd < 0) { | |
576 | ERROR("Failed to set up command socket"); | |
577 | goto on_error; | |
578 | } | |
579 | } | |
580 | TRACE("Unix domain socket %d for command server is ready", | |
581 | handler->conf->maincmd_fd); | |
582 | ||
583 | return handler; | |
584 | ||
585 | on_error: | |
586 | lxc_free_handler(handler); | |
587 | ||
588 | return NULL; | |
589 | } | |
590 | ||
591 | int lxc_init(const char *name, struct lxc_handler *handler) | |
592 | { | |
593 | const char *loglevel; | |
594 | struct lxc_conf *conf = handler->conf; | |
595 | ||
596 | lsm_init(); | |
597 | TRACE("initialized LSM"); | |
598 | ||
599 | if (lxc_read_seccomp_config(conf) != 0) { | |
600 | ERROR("Failed loading seccomp policy."); | |
601 | goto out_close_maincmd_fd; | |
602 | } | |
603 | TRACE("read seccomp policy"); | |
604 | ||
605 | /* Begin by setting the state to STARTING. */ | |
606 | if (lxc_set_state(name, handler, STARTING)) { | |
607 | ERROR("Failed to set state for container \"%s\" to \"%s\".", name, lxc_state2str(STARTING)); | |
608 | goto out_close_maincmd_fd; | |
609 | } | |
610 | TRACE("set container state to \"STARTING\""); | |
611 | ||
612 | /* Start of environment variable setup for hooks. */ | |
613 | if (name && setenv("LXC_NAME", name, 1)) | |
614 | SYSERROR("Failed to set environment variable: LXC_NAME=%s.", name); | |
615 | ||
616 | if (conf->rcfile && setenv("LXC_CONFIG_FILE", conf->rcfile, 1)) | |
617 | SYSERROR("Failed to set environment variable: LXC_CONFIG_FILE=%s.", conf->rcfile); | |
618 | ||
619 | if (conf->rootfs.mount && setenv("LXC_ROOTFS_MOUNT", conf->rootfs.mount, 1)) | |
620 | SYSERROR("Failed to set environment variable: LXC_ROOTFS_MOUNT=%s.", conf->rootfs.mount); | |
621 | ||
622 | if (conf->rootfs.path && setenv("LXC_ROOTFS_PATH", conf->rootfs.path, 1)) | |
623 | SYSERROR("Failed to set environment variable: LXC_ROOTFS_PATH=%s.", conf->rootfs.path); | |
624 | ||
625 | if (conf->console.path && setenv("LXC_CONSOLE", conf->console.path, 1)) | |
626 | SYSERROR("Failed to set environment variable: LXC_CONSOLE=%s.", conf->console.path); | |
627 | ||
628 | if (conf->console.log_path && setenv("LXC_CONSOLE_LOGPATH", conf->console.log_path, 1)) | |
629 | SYSERROR("Failed to set environment variable: LXC_CONSOLE_LOGPATH=%s.", conf->console.log_path); | |
630 | ||
631 | if (setenv("LXC_CGNS_AWARE", "1", 1)) | |
632 | SYSERROR("Failed to set environment variable LXC_CGNS_AWARE=1."); | |
633 | ||
634 | loglevel = lxc_log_priority_to_string(lxc_log_get_level()); | |
635 | if (setenv("LXC_LOG_LEVEL", loglevel, 1)) | |
636 | SYSERROR("Failed to set environment variable LXC_LOG_LEVEL=%s", loglevel); | |
637 | /* End of environment variable setup for hooks. */ | |
638 | ||
639 | TRACE("set environment variables"); | |
640 | ||
641 | if (run_lxc_hooks(name, "pre-start", conf, handler->lxcpath, NULL)) { | |
642 | ERROR("Failed to run lxc.hook.pre-start for container \"%s\".", name); | |
643 | goto out_aborting; | |
644 | } | |
645 | TRACE("ran pre-start hooks"); | |
646 | ||
647 | /* The signal fd has to be created before forking otherwise if the child | |
648 | * process exits before we setup the signal fd, the event will be lost | |
649 | * and the command will be stuck. | |
650 | */ | |
651 | handler->sigfd = setup_signal_fd(&handler->oldmask); | |
652 | if (handler->sigfd < 0) { | |
653 | ERROR("Failed to setup SIGCHLD fd handler."); | |
654 | goto out_delete_tty; | |
655 | } | |
656 | TRACE("set up signal fd"); | |
657 | ||
658 | /* Do this after setting up signals since it might unblock SIGWINCH. */ | |
659 | if (lxc_console_create(conf)) { | |
660 | ERROR("Failed to create console for container \"%s\".", name); | |
661 | goto out_restore_sigmask; | |
662 | } | |
663 | TRACE("created console"); | |
664 | ||
665 | if (lxc_ttys_shift_ids(conf) < 0) { | |
666 | ERROR("Failed to shift tty into container."); | |
667 | goto out_restore_sigmask; | |
668 | } | |
669 | TRACE("shifted tty ids"); | |
670 | ||
671 | INFO("container \"%s\" is initialized", name); | |
672 | return 0; | |
673 | ||
674 | out_restore_sigmask: | |
675 | sigprocmask(SIG_SETMASK, &handler->oldmask, NULL); | |
676 | out_delete_tty: | |
677 | lxc_delete_tty(&conf->tty_info); | |
678 | out_aborting: | |
679 | lxc_set_state(name, handler, ABORTING); | |
680 | out_close_maincmd_fd: | |
681 | close(conf->maincmd_fd); | |
682 | conf->maincmd_fd = -1; | |
683 | return -1; | |
684 | } | |
685 | ||
686 | void lxc_fini(const char *name, struct lxc_handler *handler) | |
687 | { | |
688 | int i, rc; | |
689 | struct lxc_list *cur, *next; | |
690 | pid_t self = getpid(); | |
691 | char *namespaces[LXC_NS_MAX + 1]; | |
692 | size_t namespace_count = 0; | |
693 | ||
694 | /* The STOPPING state is there for future cleanup code which can take | |
695 | * awhile. | |
696 | */ | |
697 | lxc_set_state(name, handler, STOPPING); | |
698 | ||
699 | for (i = 0; i < LXC_NS_MAX; i++) { | |
700 | if (handler->nsfd[i] != -1) { | |
701 | rc = asprintf(&namespaces[namespace_count], "%s:/proc/%d/fd/%d", | |
702 | ns_info[i].proc_name, self, handler->nsfd[i]); | |
703 | if (rc == -1) { | |
704 | SYSERROR("Failed to allocate memory."); | |
705 | break; | |
706 | } | |
707 | ++namespace_count; | |
708 | } | |
709 | } | |
710 | namespaces[namespace_count] = NULL; | |
711 | ||
712 | if (handler->conf->reboot && setenv("LXC_TARGET", "reboot", 1)) | |
713 | SYSERROR("Failed to set environment variable: LXC_TARGET=reboot."); | |
714 | ||
715 | if (!handler->conf->reboot && setenv("LXC_TARGET", "stop", 1)) | |
716 | SYSERROR("Failed to set environment variable: LXC_TARGET=stop."); | |
717 | ||
718 | if (run_lxc_hooks(name, "stop", handler->conf, handler->lxcpath, namespaces)) | |
719 | ERROR("Failed to run lxc.hook.stop for container \"%s\".", name); | |
720 | ||
721 | while (namespace_count--) | |
722 | free(namespaces[namespace_count]); | |
723 | ||
724 | for (i = 0; i < LXC_NS_MAX; i++) { | |
725 | if (handler->nsfd[i] < 0) | |
726 | continue; | |
727 | ||
728 | close(handler->nsfd[i]); | |
729 | handler->nsfd[i] = -1; | |
730 | } | |
731 | ||
732 | cgroup_destroy(handler); | |
733 | ||
734 | lxc_set_state(name, handler, STOPPED); | |
735 | ||
736 | if (handler->conf->reboot == 0) { | |
737 | /* close command socket */ | |
738 | close(handler->conf->maincmd_fd); | |
739 | handler->conf->maincmd_fd = -1; | |
740 | } | |
741 | ||
742 | if (run_lxc_hooks(name, "post-stop", handler->conf, handler->lxcpath, NULL)) { | |
743 | ERROR("Failed to run lxc.hook.post-stop for container \"%s\".", name); | |
744 | if (handler->conf->reboot) { | |
745 | WARN("Container will be stopped instead of rebooted."); | |
746 | handler->conf->reboot = 0; | |
747 | if (setenv("LXC_TARGET", "stop", 1)) | |
748 | WARN("Failed to set environment variable: LXC_TARGET=stop."); | |
749 | } | |
750 | } | |
751 | ||
752 | /* Reset mask set by setup_signal_fd. */ | |
753 | if (sigprocmask(SIG_SETMASK, &handler->oldmask, NULL)) | |
754 | WARN("Failed to restore signal mask."); | |
755 | ||
756 | lxc_console_delete(&handler->conf->console); | |
757 | lxc_delete_tty(&handler->conf->tty_info); | |
758 | ||
759 | /* The command socket is now closed, no more state clients can register | |
760 | * themselves from now on. So free the list of state clients. | |
761 | */ | |
762 | lxc_list_for_each_safe(cur, &handler->conf->state_clients, next) { | |
763 | struct lxc_state_client *client = cur->elem; | |
764 | ||
765 | /* Keep state clients that want to be notified about reboots. */ | |
766 | if ((handler->conf->reboot > 0) && (client->states[RUNNING] == 2)) | |
767 | continue; | |
768 | ||
769 | /* close state client socket */ | |
770 | close(client->clientfd); | |
771 | lxc_list_del(cur); | |
772 | free(cur->elem); | |
773 | free(cur); | |
774 | } | |
775 | ||
776 | if (handler->data_sock[0] != -1) { | |
777 | close(handler->data_sock[0]); | |
778 | close(handler->data_sock[1]); | |
779 | } | |
780 | ||
781 | if (handler->conf->ephemeral == 1 && handler->conf->reboot != 1) | |
782 | lxc_destroy_container_on_signal(handler, name); | |
783 | ||
784 | free(handler); | |
785 | } | |
786 | ||
787 | void lxc_abort(const char *name, struct lxc_handler *handler) | |
788 | { | |
789 | int ret, status; | |
790 | ||
791 | lxc_set_state(name, handler, ABORTING); | |
792 | if (handler->pid > 0) | |
793 | kill(handler->pid, SIGKILL); | |
794 | while ((ret = waitpid(-1, &status, 0)) > 0) { | |
795 | ; | |
796 | } | |
797 | } | |
798 | ||
799 | static int do_start(void *data) | |
800 | { | |
801 | int ret; | |
802 | struct lxc_list *iterator; | |
803 | char path[PATH_MAX]; | |
804 | int devnull_fd = -1; | |
805 | struct lxc_handler *handler = data; | |
806 | bool have_cap_setgid; | |
807 | uid_t new_uid; | |
808 | gid_t new_gid; | |
809 | ||
810 | if (sigprocmask(SIG_SETMASK, &handler->oldmask, NULL)) { | |
811 | SYSERROR("Failed to set signal mask."); | |
812 | return -1; | |
813 | } | |
814 | ||
815 | /* This prctl must be before the synchro, so if the parent dies before | |
816 | * we set the parent death signal, we will detect its death with the | |
817 | * synchro right after, otherwise we have a window where the parent can | |
818 | * exit before we set the pdeath signal leading to a unsupervized | |
819 | * container. | |
820 | */ | |
821 | if (prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0)) { | |
822 | SYSERROR("Failed to set PR_SET_PDEATHSIG to SIGKILL."); | |
823 | return -1; | |
824 | } | |
825 | ||
826 | lxc_sync_fini_parent(handler); | |
827 | ||
828 | /* Don't leak the pinfd to the container. */ | |
829 | if (handler->pinfd >= 0) | |
830 | close(handler->pinfd); | |
831 | ||
832 | if (lxc_sync_wait_parent(handler, LXC_SYNC_STARTUP)) | |
833 | return -1; | |
834 | ||
835 | /* Unshare CLONE_NEWNET after CLONE_NEWUSER. See | |
836 | * https://github.com/lxc/lxd/issues/1978. | |
837 | */ | |
838 | if ((handler->clone_flags & (CLONE_NEWNET | CLONE_NEWUSER)) == | |
839 | (CLONE_NEWNET | CLONE_NEWUSER)) { | |
840 | ret = unshare(CLONE_NEWNET); | |
841 | if (ret < 0) { | |
842 | SYSERROR("Failed to unshare CLONE_NEWNET."); | |
843 | goto out_warn_father; | |
844 | } | |
845 | INFO("Unshared CLONE_NEWNET."); | |
846 | } | |
847 | ||
848 | /* Tell the parent task it can begin to configure the container and wait | |
849 | * for it to finish. | |
850 | */ | |
851 | if (lxc_sync_barrier_parent(handler, LXC_SYNC_CONFIGURE)) | |
852 | return -1; | |
853 | ||
854 | if (lxc_network_recv_veth_names_from_parent(handler) < 0) { | |
855 | ERROR("Failed to receive veth names from parent"); | |
856 | goto out_warn_father; | |
857 | } | |
858 | ||
859 | /* If we are in a new user namespace, become root there to have | |
860 | * privilege over our namespace. | |
861 | */ | |
862 | if (!lxc_list_empty(&handler->conf->id_map)) { | |
863 | if (lxc_switch_uid_gid(0, 0) < 0) | |
864 | goto out_warn_father; | |
865 | ||
866 | /* Drop groups only after we switched to a valid gid in the new | |
867 | * user namespace. | |
868 | */ | |
869 | if (lxc_setgroups(0, NULL) < 0) | |
870 | goto out_warn_father; | |
871 | } | |
872 | ||
873 | if (access(handler->lxcpath, X_OK)) { | |
874 | print_top_failing_dir(handler->lxcpath); | |
875 | goto out_warn_father; | |
876 | } | |
877 | ||
878 | ret = snprintf(path, sizeof(path), "%s/dev/null", handler->conf->rootfs.mount); | |
879 | if (ret < 0 || ret >= sizeof(path)) | |
880 | goto out_warn_father; | |
881 | ||
882 | /* In order to checkpoint restore, we need to have everything in the | |
883 | * same mount namespace. However, some containers may not have a | |
884 | * reasonable /dev (in particular, they may not have /dev/null), so we | |
885 | * can't set init's std fds to /dev/null by opening it from inside the | |
886 | * container. | |
887 | * | |
888 | * If that's the case, fall back to using the host's /dev/null. This | |
889 | * means that migration won't work, but at least we won't spew output | |
890 | * where it isn't wanted. | |
891 | */ | |
892 | if (handler->backgrounded && !handler->conf->autodev && access(path, F_OK) < 0) { | |
893 | devnull_fd = open_devnull(); | |
894 | ||
895 | if (devnull_fd < 0) | |
896 | goto out_warn_father; | |
897 | WARN("Using /dev/null from the host for container init's " | |
898 | "standard file descriptors. Migration will not work."); | |
899 | } | |
900 | ||
901 | /* Ask father to setup cgroups and wait for him to finish. */ | |
902 | if (lxc_sync_barrier_parent(handler, LXC_SYNC_CGROUP)) | |
903 | goto out_error; | |
904 | ||
905 | /* Unshare cgroup namespace after we have setup our cgroups. If we do it | |
906 | * earlier we end up with a wrong view of /proc/self/cgroup. For | |
907 | * example, assume we unshare(CLONE_NEWCGROUP) first, and then create | |
908 | * the cgroup for the container, say /sys/fs/cgroup/cpuset/lxc/c, then | |
909 | * /proc/self/cgroup would show us: | |
910 | * | |
911 | * 8:cpuset:/lxc/c | |
912 | * | |
913 | * whereas it should actually show | |
914 | * | |
915 | * 8:cpuset:/ | |
916 | */ | |
917 | if (cgns_supported()) { | |
918 | if (unshare(CLONE_NEWCGROUP) < 0) { | |
919 | INFO("Failed to unshare CLONE_NEWCGROUP."); | |
920 | goto out_warn_father; | |
921 | } | |
922 | INFO("Unshared CLONE_NEWCGROUP."); | |
923 | } | |
924 | ||
925 | /* Add the requested environment variables to the current environment to | |
926 | * allow them to be used by the various hooks, such as the start hook | |
927 | * above. | |
928 | */ | |
929 | lxc_list_for_each(iterator, &handler->conf->environment) { | |
930 | if (putenv((char *)iterator->elem)) { | |
931 | SYSERROR("Failed to set environment variable: %s.", (char *)iterator->elem); | |
932 | goto out_warn_father; | |
933 | } | |
934 | } | |
935 | ||
936 | /* Setup the container, ip, names, utsname, ... */ | |
937 | ret = lxc_setup(handler); | |
938 | close(handler->data_sock[0]); | |
939 | close(handler->data_sock[1]); | |
940 | if (ret < 0) { | |
941 | ERROR("Failed to setup container \"%s\".", handler->name); | |
942 | goto out_warn_father; | |
943 | } | |
944 | ||
945 | /* Set the label to change to when we exec(2) the container's init. */ | |
946 | if (lsm_process_label_set(NULL, handler->conf, 1, 1) < 0) | |
947 | goto out_warn_father; | |
948 | ||
949 | /* Set PR_SET_NO_NEW_PRIVS after we changed the lsm label. If we do it | |
950 | * before we aren't allowed anymore. | |
951 | */ | |
952 | if (handler->conf->no_new_privs) { | |
953 | if (prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0) < 0) { | |
954 | SYSERROR("Could not set PR_SET_NO_NEW_PRIVS to block execve() gainable privileges."); | |
955 | goto out_warn_father; | |
956 | } | |
957 | DEBUG("Set PR_SET_NO_NEW_PRIVS to block execve() gainable privileges."); | |
958 | } | |
959 | ||
960 | /* Some init's such as busybox will set sane tty settings on stdin, | |
961 | * stdout, stderr which it thinks is the console. We already set them | |
962 | * the way we wanted on the real terminal, and we want init to do its | |
963 | * setup on its console ie. the pty allocated in lxc_console_create() so | |
964 | * make sure that that pty is stdin,stdout,stderr. | |
965 | */ | |
966 | if (handler->conf->console.slave >= 0) | |
967 | if (set_stdfds(handler->conf->console.slave) < 0) { | |
968 | ERROR("Failed to redirect std{in,out,err} to pty file " | |
969 | "descriptor %d", | |
970 | handler->conf->console.slave); | |
971 | goto out_warn_father; | |
972 | } | |
973 | ||
974 | /* If we mounted a temporary proc, then unmount it now. */ | |
975 | tmp_proc_unmount(handler->conf); | |
976 | ||
977 | if (lxc_seccomp_load(handler->conf) != 0) | |
978 | goto out_warn_father; | |
979 | ||
980 | if (run_lxc_hooks(handler->name, "start", handler->conf, handler->lxcpath, NULL)) { | |
981 | ERROR("Failed to run lxc.hook.start for container \"%s\".", handler->name); | |
982 | goto out_warn_father; | |
983 | } | |
984 | ||
985 | close(handler->sigfd); | |
986 | ||
987 | if (devnull_fd < 0) { | |
988 | devnull_fd = open_devnull(); | |
989 | ||
990 | if (devnull_fd < 0) | |
991 | goto out_warn_father; | |
992 | } | |
993 | ||
994 | if (handler->conf->console.slave < 0 && handler->backgrounded) | |
995 | if (set_stdfds(devnull_fd) < 0) { | |
996 | ERROR("Failed to redirect std{in,out,err} to " | |
997 | "\"/dev/null\""); | |
998 | goto out_warn_father; | |
999 | } | |
1000 | ||
1001 | if (devnull_fd >= 0) { | |
1002 | close(devnull_fd); | |
1003 | devnull_fd = -1; | |
1004 | } | |
1005 | ||
1006 | setsid(); | |
1007 | ||
1008 | if (handler->conf->init_cwd && chdir(handler->conf->init_cwd)) { | |
1009 | SYSERROR("Could not change directory to \"%s\"", handler->conf->init_cwd); | |
1010 | goto out_warn_father; | |
1011 | } | |
1012 | ||
1013 | if (lxc_sync_barrier_parent(handler, LXC_SYNC_CGROUP_LIMITS)) | |
1014 | goto out_warn_father; | |
1015 | ||
1016 | /* Reset the environment variables the user requested in a clear | |
1017 | * environment. | |
1018 | */ | |
1019 | if (clearenv()) { | |
1020 | SYSERROR("Failed to clear environment."); | |
1021 | /* Don't error out though. */ | |
1022 | } | |
1023 | ||
1024 | lxc_list_for_each(iterator, &handler->conf->environment) { | |
1025 | if (putenv((char *)iterator->elem)) { | |
1026 | SYSERROR("Failed to set environment variable: %s.", (char *)iterator->elem); | |
1027 | goto out_warn_father; | |
1028 | } | |
1029 | } | |
1030 | ||
1031 | if (putenv("container=lxc")) { | |
1032 | SYSERROR("Failed to set environment variable: container=lxc."); | |
1033 | goto out_warn_father; | |
1034 | } | |
1035 | ||
1036 | if (handler->conf->pty_names) { | |
1037 | if (putenv(handler->conf->pty_names)) { | |
1038 | SYSERROR("Failed to set environment variable for container ptys."); | |
1039 | goto out_warn_father; | |
1040 | } | |
1041 | } | |
1042 | ||
1043 | /* The container has been setup. We can now switch to an unprivileged | |
1044 | * uid/gid. | |
1045 | */ | |
1046 | new_uid = handler->conf->init_uid; | |
1047 | new_gid = handler->conf->init_gid; | |
1048 | ||
1049 | /* If we are in a new user namespace we already dropped all | |
1050 | * groups when we switched to root in the new user namespace | |
1051 | * further above. Only drop groups if we can, so ensure that we | |
1052 | * have necessary privilege. | |
1053 | */ | |
1054 | #if HAVE_LIBCAP | |
1055 | have_cap_setgid = lxc_proc_cap_is_set(CAP_SETGID, CAP_EFFECTIVE); | |
1056 | #else | |
1057 | have_cap_setgid = false; | |
1058 | #endif | |
1059 | if (lxc_list_empty(&handler->conf->id_map) && have_cap_setgid) { | |
1060 | if (lxc_setgroups(0, NULL) < 0) | |
1061 | goto out_warn_father; | |
1062 | } | |
1063 | ||
1064 | if (lxc_switch_uid_gid(new_uid, new_gid) < 0) | |
1065 | goto out_warn_father; | |
1066 | ||
1067 | /* After this call, we are in error because this ops should not return | |
1068 | * as it execs. | |
1069 | */ | |
1070 | handler->ops->start(handler, handler->data); | |
1071 | ||
1072 | out_warn_father: | |
1073 | /* We want the parent to know something went wrong, so we return a | |
1074 | * special error code. | |
1075 | */ | |
1076 | lxc_sync_wake_parent(handler, LXC_SYNC_ERROR); | |
1077 | ||
1078 | out_error: | |
1079 | if (devnull_fd >= 0) | |
1080 | close(devnull_fd); | |
1081 | ||
1082 | return -1; | |
1083 | } | |
1084 | ||
1085 | static int lxc_recv_ttys_from_child(struct lxc_handler *handler) | |
1086 | { | |
1087 | int i; | |
1088 | struct lxc_pty_info *pty_info; | |
1089 | int ret = -1; | |
1090 | int sock = handler->data_sock[1]; | |
1091 | struct lxc_conf *conf = handler->conf; | |
1092 | struct lxc_tty_info *tty_info = &conf->tty_info; | |
1093 | ||
1094 | if (!conf->tty) | |
1095 | return 0; | |
1096 | ||
1097 | tty_info->pty_info = malloc(sizeof(*tty_info->pty_info) * conf->tty); | |
1098 | if (!tty_info->pty_info) | |
1099 | return -1; | |
1100 | ||
1101 | for (i = 0; i < conf->tty; i++) { | |
1102 | int ttyfds[2]; | |
1103 | ||
1104 | ret = lxc_abstract_unix_recv_fds(sock, ttyfds, 2, NULL, 0); | |
1105 | if (ret < 0) | |
1106 | break; | |
1107 | ||
1108 | pty_info = &tty_info->pty_info[i]; | |
1109 | pty_info->busy = 0; | |
1110 | pty_info->master = ttyfds[0]; | |
1111 | pty_info->slave = ttyfds[1]; | |
1112 | TRACE("Received pty with master fd %d and slave fd %d from " | |
1113 | "parent", pty_info->master, pty_info->slave); | |
1114 | } | |
1115 | if (ret < 0) | |
1116 | ERROR("Failed to receive %d ttys from child: %s", conf->tty, | |
1117 | strerror(errno)); | |
1118 | else | |
1119 | TRACE("Received %d ttys from child", conf->tty); | |
1120 | ||
1121 | tty_info->nbtty = conf->tty; | |
1122 | ||
1123 | return ret; | |
1124 | } | |
1125 | ||
1126 | void resolve_clone_flags(struct lxc_handler *handler) | |
1127 | { | |
1128 | handler->clone_flags = CLONE_NEWNS; | |
1129 | ||
1130 | if (!handler->conf->inherit_ns[LXC_NS_USER]) { | |
1131 | if (!lxc_list_empty(&handler->conf->id_map)) | |
1132 | handler->clone_flags |= CLONE_NEWUSER; | |
1133 | } else { | |
1134 | INFO("Inheriting user namespace"); | |
1135 | } | |
1136 | ||
1137 | if (!handler->conf->inherit_ns[LXC_NS_NET]) { | |
1138 | if (!lxc_requests_empty_network(handler)) | |
1139 | handler->clone_flags |= CLONE_NEWNET; | |
1140 | } else { | |
1141 | INFO("Inheriting net namespace"); | |
1142 | } | |
1143 | ||
1144 | if (!handler->conf->inherit_ns[LXC_NS_IPC]) | |
1145 | handler->clone_flags |= CLONE_NEWIPC; | |
1146 | else | |
1147 | INFO("Inheriting ipc namespace"); | |
1148 | ||
1149 | if (!handler->conf->inherit_ns[LXC_NS_UTS]) | |
1150 | handler->clone_flags |= CLONE_NEWUTS; | |
1151 | else | |
1152 | INFO("Inheriting uts namespace"); | |
1153 | ||
1154 | if (!handler->conf->inherit_ns[LXC_NS_PID]) | |
1155 | handler->clone_flags |= CLONE_NEWPID; | |
1156 | else | |
1157 | INFO("Inheriting pid namespace"); | |
1158 | } | |
1159 | ||
1160 | static pid_t lxc_fork_attach_clone(int (*fn)(void *), void *arg, int flags) | |
1161 | { | |
1162 | int i, r, ret; | |
1163 | pid_t pid, init_pid; | |
1164 | struct lxc_handler *handler = arg; | |
1165 | ||
1166 | pid = fork(); | |
1167 | if (pid < 0) | |
1168 | return -1; | |
1169 | ||
1170 | if (!pid) { | |
1171 | for (i = 0; i < LXC_NS_MAX; i++) { | |
1172 | if (handler->nsfd[i] < 0) | |
1173 | continue; | |
1174 | ||
1175 | ret = setns(handler->nsfd[i], 0); | |
1176 | if (ret < 0) | |
1177 | exit(EXIT_FAILURE); | |
1178 | ||
1179 | DEBUG("Inherited %s namespace", ns_info[i].proc_name); | |
1180 | } | |
1181 | ||
1182 | init_pid = lxc_clone(do_start, handler, flags); | |
1183 | ret = lxc_write_nointr(handler->data_sock[1], &init_pid, | |
1184 | sizeof(init_pid)); | |
1185 | if (ret < 0) | |
1186 | exit(EXIT_FAILURE); | |
1187 | ||
1188 | exit(EXIT_SUCCESS); | |
1189 | } | |
1190 | ||
1191 | r = lxc_read_nointr(handler->data_sock[0], &init_pid, sizeof(init_pid)); | |
1192 | ret = wait_for_pid(pid); | |
1193 | if (ret < 0 || r < 0) | |
1194 | return -1; | |
1195 | ||
1196 | return init_pid; | |
1197 | } | |
1198 | ||
1199 | /* lxc_spawn() performs crucial setup tasks and clone()s the new process which | |
1200 | * exec()s the requested container binary. | |
1201 | * Note that lxc_spawn() runs in the parent namespaces. Any operations performed | |
1202 | * right here should be double checked if they'd pose a security risk. (For | |
1203 | * example, any {u}mount() operations performed here will be reflected on the | |
1204 | * host!) | |
1205 | */ | |
1206 | static int lxc_spawn(struct lxc_handler *handler) | |
1207 | { | |
1208 | int i, flags, ret; | |
1209 | char pidstr[20]; | |
1210 | bool wants_to_map_ids; | |
1211 | struct lxc_list *id_map; | |
1212 | const char *name = handler->name; | |
1213 | const char *lxcpath = handler->lxcpath; | |
1214 | bool cgroups_connected = false, fork_before_clone = false; | |
1215 | struct lxc_conf *conf = handler->conf; | |
1216 | ||
1217 | id_map = &conf->id_map; | |
1218 | wants_to_map_ids = !lxc_list_empty(id_map); | |
1219 | ||
1220 | for (i = 0; i < LXC_NS_MAX; i++) { | |
1221 | if (!conf->inherit_ns[i]) | |
1222 | continue; | |
1223 | ||
1224 | handler->nsfd[i] = lxc_inherit_namespace(conf->inherit_ns[i], lxcpath, ns_info[i].proc_name); | |
1225 | if (handler->nsfd[i] < 0) | |
1226 | return -1; | |
1227 | ||
1228 | fork_before_clone = true; | |
1229 | } | |
1230 | ||
1231 | if (lxc_sync_init(handler)) | |
1232 | return -1; | |
1233 | ||
1234 | ret = socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0, | |
1235 | handler->data_sock); | |
1236 | if (ret < 0) { | |
1237 | lxc_sync_fini(handler); | |
1238 | return -1; | |
1239 | } | |
1240 | ||
1241 | resolve_clone_flags(handler); | |
1242 | ||
1243 | if (handler->clone_flags & CLONE_NEWNET) { | |
1244 | if (!lxc_list_empty(&conf->network)) { | |
1245 | ||
1246 | /* Find gateway addresses from the link device, which is | |
1247 | * no longer accessible inside the container. Do this | |
1248 | * before creating network interfaces, since goto | |
1249 | * out_delete_net does not work before lxc_clone. | |
1250 | */ | |
1251 | if (lxc_find_gateway_addresses(handler)) { | |
1252 | ERROR("Failed to find gateway addresses."); | |
1253 | lxc_sync_fini(handler); | |
1254 | return -1; | |
1255 | } | |
1256 | ||
1257 | /* That should be done before the clone because we will | |
1258 | * fill the netdev index and use them in the child. | |
1259 | */ | |
1260 | if (lxc_create_network_priv(handler)) { | |
1261 | ERROR("Failed to create the network."); | |
1262 | lxc_sync_fini(handler); | |
1263 | return -1; | |
1264 | } | |
1265 | } | |
1266 | } | |
1267 | ||
1268 | if (!cgroup_init(handler)) { | |
1269 | ERROR("Failed initializing cgroup support."); | |
1270 | goto out_delete_net; | |
1271 | } | |
1272 | ||
1273 | cgroups_connected = true; | |
1274 | ||
1275 | if (!cgroup_create(handler)) { | |
1276 | ERROR("Failed creating cgroups."); | |
1277 | goto out_delete_net; | |
1278 | } | |
1279 | ||
1280 | /* If the rootfs is not a blockdev, prevent the container from marking | |
1281 | * it readonly. | |
1282 | * If the container is unprivileged then skip rootfs pinning. | |
1283 | */ | |
1284 | if (!wants_to_map_ids) { | |
1285 | handler->pinfd = pin_rootfs(conf->rootfs.path); | |
1286 | if (handler->pinfd == -1) | |
1287 | INFO("Failed to pin the rootfs for container \"%s\".", handler->name); | |
1288 | } | |
1289 | ||
1290 | /* Create a process in a new set of namespaces. */ | |
1291 | flags = handler->clone_flags; | |
1292 | if (handler->clone_flags & CLONE_NEWUSER) { | |
1293 | /* If CLONE_NEWUSER and CLONE_NEWNET was requested, we need to | |
1294 | * clone a new user namespace first and only later unshare our | |
1295 | * network namespace to ensure that network devices ownership is | |
1296 | * set up correctly. | |
1297 | */ | |
1298 | flags &= ~CLONE_NEWNET; | |
1299 | } | |
1300 | ||
1301 | if (fork_before_clone) | |
1302 | handler->pid = lxc_fork_attach_clone(do_start, handler, flags | CLONE_PARENT); | |
1303 | else | |
1304 | handler->pid = lxc_clone(do_start, handler, flags); | |
1305 | if (handler->pid < 0) { | |
1306 | SYSERROR("Failed to clone a new set of namespaces."); | |
1307 | goto out_delete_net; | |
1308 | } | |
1309 | TRACE("Cloned child process %d", handler->pid); | |
1310 | ||
1311 | for (i = 0; i < LXC_NS_MAX; i++) | |
1312 | if (flags & ns_info[i].clone_flag) | |
1313 | INFO("Cloned %s", ns_info[i].flag_name); | |
1314 | ||
1315 | if (!preserve_ns(handler->nsfd, handler->clone_flags & ~CLONE_NEWNET, handler->pid)) { | |
1316 | ERROR("Failed to preserve cloned namespaces for lxc.hook.stop"); | |
1317 | goto out_delete_net; | |
1318 | } | |
1319 | ||
1320 | lxc_sync_fini_child(handler); | |
1321 | ||
1322 | /* Map the container uids. The container became an invalid userid the | |
1323 | * moment it was cloned with CLONE_NEWUSER. This call doesn't change | |
1324 | * anything immediately, but allows the container to setuid(0) (0 being | |
1325 | * mapped to something else on the host.) later to become a valid uid | |
1326 | * again. | |
1327 | */ | |
1328 | if (wants_to_map_ids) { | |
1329 | if (!handler->conf->inherit_ns[LXC_NS_USER]) { | |
1330 | ret = lxc_map_ids(id_map, handler->pid); | |
1331 | if (ret < 0) { | |
1332 | ERROR("Failed to set up id mapping."); | |
1333 | goto out_delete_net; | |
1334 | } | |
1335 | } | |
1336 | } | |
1337 | ||
1338 | if (lxc_sync_wake_child(handler, LXC_SYNC_STARTUP)) | |
1339 | goto out_delete_net; | |
1340 | ||
1341 | if (lxc_sync_wait_child(handler, LXC_SYNC_CONFIGURE)) | |
1342 | goto out_delete_net; | |
1343 | ||
1344 | if (!cgroup_create_legacy(handler)) { | |
1345 | ERROR("Failed to setup legacy cgroups for container \"%s\".", name); | |
1346 | goto out_delete_net; | |
1347 | } | |
1348 | if (!cgroup_setup_limits(handler, false)) { | |
1349 | ERROR("Failed to setup cgroup limits for container \"%s\".", name); | |
1350 | goto out_delete_net; | |
1351 | } | |
1352 | ||
1353 | if (!cgroup_enter(handler)) | |
1354 | goto out_delete_net; | |
1355 | ||
1356 | if (!cgroup_chown(handler)) | |
1357 | goto out_delete_net; | |
1358 | ||
1359 | /* Now we're ready to preserve the network namespace */ | |
1360 | ret = lxc_preserve_ns(handler->pid, "net"); | |
1361 | if (ret < 0) { | |
1362 | ERROR("%s - Failed to preserve net namespace", strerror(errno)); | |
1363 | goto out_delete_net; | |
1364 | } | |
1365 | handler->nsfd[LXC_NS_NET] = ret; | |
1366 | DEBUG("Preserved net namespace via fd %d", ret); | |
1367 | ||
1368 | /* Create the network configuration. */ | |
1369 | if (handler->clone_flags & CLONE_NEWNET) { | |
1370 | if (lxc_network_move_created_netdev_priv(handler->lxcpath, | |
1371 | handler->name, | |
1372 | &conf->network, | |
1373 | handler->pid)) { | |
1374 | ERROR("Failed to create the configured network."); | |
1375 | goto out_delete_net; | |
1376 | } | |
1377 | ||
1378 | if (lxc_create_network_unpriv(handler->lxcpath, handler->name, | |
1379 | &conf->network, | |
1380 | handler->pid)) { | |
1381 | ERROR("Failed to create the configured network."); | |
1382 | goto out_delete_net; | |
1383 | } | |
1384 | } | |
1385 | ||
1386 | if (lxc_network_send_veth_names_to_child(handler) < 0) { | |
1387 | ERROR("Failed to send veth names to child"); | |
1388 | goto out_delete_net; | |
1389 | } | |
1390 | ||
1391 | /* Tell the child to continue its initialization. We'll get | |
1392 | * LXC_SYNC_CGROUP when it is ready for us to setup cgroups. | |
1393 | */ | |
1394 | if (lxc_sync_barrier_child(handler, LXC_SYNC_POST_CONFIGURE)) | |
1395 | goto out_delete_net; | |
1396 | ||
1397 | if (!lxc_list_empty(&conf->limits) && setup_resource_limits(&conf->limits, handler->pid)) { | |
1398 | ERROR("failed to setup resource limits for '%s'", name); | |
1399 | goto out_delete_net; | |
1400 | } | |
1401 | ||
1402 | if (lxc_sync_barrier_child(handler, LXC_SYNC_CGROUP_UNSHARE)) | |
1403 | goto out_delete_net; | |
1404 | ||
1405 | if (!cgroup_setup_limits(handler, true)) { | |
1406 | ERROR("Failed to setup the devices cgroup for container \"%s\".", name); | |
1407 | goto out_delete_net; | |
1408 | } | |
1409 | TRACE("Set up cgroup device limits"); | |
1410 | ||
1411 | cgroup_disconnect(); | |
1412 | cgroups_connected = false; | |
1413 | ||
1414 | snprintf(pidstr, 20, "%d", handler->pid); | |
1415 | if (setenv("LXC_PID", pidstr, 1)) | |
1416 | SYSERROR("Failed to set environment variable: LXC_PID=%s.", pidstr); | |
1417 | ||
1418 | /* Run any host-side start hooks */ | |
1419 | if (run_lxc_hooks(name, "start-host", conf, handler->lxcpath, NULL)) { | |
1420 | ERROR("Failed to run lxc.hook.start-host for container \"%s\".", name); | |
1421 | return -1; | |
1422 | } | |
1423 | ||
1424 | /* Tell the child to complete its initialization and wait for it to exec | |
1425 | * or return an error. (The child will never return | |
1426 | * LXC_SYNC_READY_START+1. It will either close the sync pipe, causing | |
1427 | * lxc_sync_barrier_child to return success, or return a different | |
1428 | * value, causing us to error out). | |
1429 | */ | |
1430 | if (lxc_sync_barrier_child(handler, LXC_SYNC_READY_START)) | |
1431 | return -1; | |
1432 | ||
1433 | if (cgns_supported()) { | |
1434 | ret = lxc_preserve_ns(handler->pid, "cgroup"); | |
1435 | if (ret < 0) { | |
1436 | ERROR("%s - Failed to preserve cgroup namespace", strerror(errno)); | |
1437 | goto out_delete_net; | |
1438 | } | |
1439 | handler->nsfd[LXC_NS_CGROUP] = ret; | |
1440 | DEBUG("Preserved cgroup namespace via fd %d", ret); | |
1441 | } | |
1442 | ||
1443 | if (lxc_network_recv_name_and_ifindex_from_child(handler) < 0) { | |
1444 | ERROR("Failed to receive names and ifindices for network " | |
1445 | "devices from child"); | |
1446 | goto out_delete_net; | |
1447 | } | |
1448 | ||
1449 | /* Now all networks are created, network devices are moved into place, | |
1450 | * and the correct names and ifindeces in the respective namespaces have | |
1451 | * been recorded. The corresponding structs have now all been filled. So | |
1452 | * log them for debugging purposes. | |
1453 | */ | |
1454 | lxc_log_configured_netdevs(conf); | |
1455 | ||
1456 | /* Read tty fds allocated by child. */ | |
1457 | if (lxc_recv_ttys_from_child(handler) < 0) { | |
1458 | ERROR("Failed to receive tty info from child process."); | |
1459 | goto out_delete_net; | |
1460 | } | |
1461 | ||
1462 | if (handler->ops->post_start(handler, handler->data)) | |
1463 | goto out_abort; | |
1464 | ||
1465 | if (lxc_set_state(name, handler, RUNNING)) { | |
1466 | ERROR("Failed to set state for container \"%s\" to \"%s\".", name, | |
1467 | lxc_state2str(RUNNING)); | |
1468 | goto out_abort; | |
1469 | } | |
1470 | ||
1471 | lxc_sync_fini(handler); | |
1472 | ||
1473 | return 0; | |
1474 | ||
1475 | out_delete_net: | |
1476 | if (cgroups_connected) | |
1477 | cgroup_disconnect(); | |
1478 | ||
1479 | if (handler->clone_flags & CLONE_NEWNET) | |
1480 | lxc_delete_network(handler); | |
1481 | ||
1482 | out_abort: | |
1483 | lxc_abort(name, handler); | |
1484 | lxc_sync_fini(handler); | |
1485 | if (handler->pinfd >= 0) { | |
1486 | close(handler->pinfd); | |
1487 | handler->pinfd = -1; | |
1488 | } | |
1489 | ||
1490 | return -1; | |
1491 | } | |
1492 | ||
1493 | int __lxc_start(const char *name, struct lxc_handler *handler, | |
1494 | struct lxc_operations* ops, void *data, const char *lxcpath, | |
1495 | bool backgrounded) | |
1496 | { | |
1497 | int status; | |
1498 | int err = -1; | |
1499 | struct lxc_conf *conf = handler->conf; | |
1500 | ||
1501 | if (lxc_init(name, handler) < 0) { | |
1502 | ERROR("Failed to initialize container \"%s\".", name); | |
1503 | return -1; | |
1504 | } | |
1505 | handler->ops = ops; | |
1506 | handler->data = data; | |
1507 | handler->backgrounded = backgrounded; | |
1508 | ||
1509 | if (!attach_block_device(handler->conf)) { | |
1510 | ERROR("Failed to attach block device."); | |
1511 | goto out_fini_nonet; | |
1512 | } | |
1513 | ||
1514 | if (geteuid() == 0 && !lxc_list_empty(&conf->id_map)) { | |
1515 | /* If the backing store is a device, mount it here and now. */ | |
1516 | if (rootfs_is_blockdev(conf)) { | |
1517 | if (unshare(CLONE_NEWNS) < 0) { | |
1518 | ERROR("Failed to unshare CLONE_NEWNS."); | |
1519 | goto out_fini_nonet; | |
1520 | } | |
1521 | INFO("Unshared CLONE_NEWNS."); | |
1522 | ||
1523 | remount_all_slave(); | |
1524 | if (do_rootfs_setup(conf, name, lxcpath) < 0) { | |
1525 | ERROR("Error setting up rootfs mount as root before spawn."); | |
1526 | goto out_fini_nonet; | |
1527 | } | |
1528 | INFO("Set up container rootfs as host root."); | |
1529 | } | |
1530 | } | |
1531 | ||
1532 | err = lxc_spawn(handler); | |
1533 | if (err) { | |
1534 | ERROR("Failed to spawn container \"%s\".", name); | |
1535 | goto out_detach_blockdev; | |
1536 | } | |
1537 | /* close parent side of data socket */ | |
1538 | close(handler->data_sock[0]); | |
1539 | handler->data_sock[0] = -1; | |
1540 | close(handler->data_sock[1]); | |
1541 | handler->data_sock[1] = -1; | |
1542 | ||
1543 | handler->conf->reboot = 0; | |
1544 | ||
1545 | err = lxc_poll(name, handler); | |
1546 | if (err) { | |
1547 | ERROR("LXC mainloop exited with error: %d.", err); | |
1548 | goto out_abort; | |
1549 | } | |
1550 | ||
1551 | while (waitpid(handler->pid, &status, 0) < 0 && errno == EINTR) | |
1552 | continue; | |
1553 | ||
1554 | /* If the child process exited but was not signaled, it didn't call | |
1555 | * reboot. This should mean it was an lxc-execute which simply exited. | |
1556 | * In any case, treat it as a 'halt'. | |
1557 | */ | |
1558 | if (WIFSIGNALED(status)) { | |
1559 | switch(WTERMSIG(status)) { | |
1560 | case SIGINT: /* halt */ | |
1561 | DEBUG("Container \"%s\" is halting.", name); | |
1562 | break; | |
1563 | case SIGHUP: /* reboot */ | |
1564 | DEBUG("Container \"%s\" is rebooting.", name); | |
1565 | handler->conf->reboot = 1; | |
1566 | break; | |
1567 | case SIGSYS: /* seccomp */ | |
1568 | DEBUG("Container \"%s\" violated its seccomp policy.", name); | |
1569 | break; | |
1570 | default: | |
1571 | DEBUG("Unknown exit status for container \"%s\" init %d.", name, WTERMSIG(status)); | |
1572 | break; | |
1573 | } | |
1574 | } | |
1575 | ||
1576 | err = lxc_restore_phys_nics_to_netns(handler); | |
1577 | if (err < 0) | |
1578 | ERROR("Failed to move physical network devices back to parent " | |
1579 | "network namespace"); | |
1580 | ||
1581 | if (handler->pinfd >= 0) { | |
1582 | close(handler->pinfd); | |
1583 | handler->pinfd = -1; | |
1584 | } | |
1585 | ||
1586 | lxc_monitor_send_exit_code(name, status, handler->lxcpath); | |
1587 | err = lxc_error_set_and_log(handler->pid, status); | |
1588 | ||
1589 | out_fini: | |
1590 | lxc_delete_network(handler); | |
1591 | ||
1592 | out_detach_blockdev: | |
1593 | detach_block_device(handler->conf); | |
1594 | ||
1595 | out_fini_nonet: | |
1596 | lxc_fini(name, handler); | |
1597 | return err; | |
1598 | ||
1599 | out_abort: | |
1600 | lxc_abort(name, handler); | |
1601 | goto out_fini; | |
1602 | } | |
1603 | ||
1604 | struct start_args { | |
1605 | char *const *argv; | |
1606 | }; | |
1607 | ||
1608 | static int start(struct lxc_handler *handler, void* data) | |
1609 | { | |
1610 | struct start_args *arg = data; | |
1611 | ||
1612 | NOTICE("Exec'ing \"%s\".", arg->argv[0]); | |
1613 | ||
1614 | execvp(arg->argv[0], arg->argv); | |
1615 | SYSERROR("Failed to exec \"%s\".", arg->argv[0]); | |
1616 | return 0; | |
1617 | } | |
1618 | ||
1619 | static int post_start(struct lxc_handler *handler, void* data) | |
1620 | { | |
1621 | struct start_args *arg = data; | |
1622 | ||
1623 | NOTICE("Started \"%s\" with pid \"%d\".", arg->argv[0], handler->pid); | |
1624 | return 0; | |
1625 | } | |
1626 | ||
1627 | static struct lxc_operations start_ops = { | |
1628 | .start = start, | |
1629 | .post_start = post_start | |
1630 | }; | |
1631 | ||
1632 | int lxc_start(const char *name, char *const argv[], struct lxc_handler *handler, | |
1633 | const char *lxcpath, bool backgrounded) | |
1634 | { | |
1635 | struct start_args start_arg = { | |
1636 | .argv = argv, | |
1637 | }; | |
1638 | ||
1639 | return __lxc_start(name, handler, &start_ops, &start_arg, lxcpath, backgrounded); | |
1640 | } | |
1641 | ||
1642 | static void lxc_destroy_container_on_signal(struct lxc_handler *handler, | |
1643 | const char *name) | |
1644 | { | |
1645 | char destroy[MAXPATHLEN]; | |
1646 | bool bret = true; | |
1647 | int ret = 0; | |
1648 | struct lxc_container *c; | |
1649 | if (handler->conf->rootfs.path && handler->conf->rootfs.mount) { | |
1650 | bret = do_destroy_container(handler); | |
1651 | if (!bret) { | |
1652 | ERROR("Error destroying rootfs for container \"%s\".", name); | |
1653 | return; | |
1654 | } | |
1655 | } | |
1656 | INFO("Destroyed rootfs for container \"%s\".", name); | |
1657 | ||
1658 | ret = snprintf(destroy, MAXPATHLEN, "%s/%s", handler->lxcpath, name); | |
1659 | if (ret < 0 || ret >= MAXPATHLEN) { | |
1660 | ERROR("Error destroying directory for container \"%s\".", name); | |
1661 | return; | |
1662 | } | |
1663 | ||
1664 | c = lxc_container_new(name, handler->lxcpath); | |
1665 | if (c) { | |
1666 | if (container_disk_lock(c)) { | |
1667 | INFO("Could not update lxc_snapshots file."); | |
1668 | lxc_container_put(c); | |
1669 | } else { | |
1670 | mod_all_rdeps(c, false); | |
1671 | container_disk_unlock(c); | |
1672 | lxc_container_put(c); | |
1673 | } | |
1674 | } | |
1675 | ||
1676 | if (!handler->am_root) | |
1677 | ret = userns_exec_full(handler->conf, lxc_rmdir_onedev_wrapper, | |
1678 | destroy, "lxc_rmdir_onedev_wrapper"); | |
1679 | else | |
1680 | ret = lxc_rmdir_onedev(destroy, NULL); | |
1681 | ||
1682 | if (ret < 0) { | |
1683 | ERROR("Error destroying directory for container \"%s\".", name); | |
1684 | return; | |
1685 | } | |
1686 | INFO("Destroyed directory for container \"%s\".", name); | |
1687 | } | |
1688 | ||
1689 | static int lxc_rmdir_onedev_wrapper(void *data) | |
1690 | { | |
1691 | char *arg = (char *) data; | |
1692 | return lxc_rmdir_onedev(arg, NULL); | |
1693 | } | |
1694 | ||
1695 | static bool do_destroy_container(struct lxc_handler *handler) { | |
1696 | int ret; | |
1697 | ||
1698 | if (!handler->am_root) { | |
1699 | ret = userns_exec_full(handler->conf, storage_destroy_wrapper, | |
1700 | handler->conf, "storage_destroy_wrapper"); | |
1701 | if (ret < 0) | |
1702 | return false; | |
1703 | ||
1704 | return true; | |
1705 | } | |
1706 | ||
1707 | return storage_destroy(handler->conf); | |
1708 | } |