]>
Commit | Line | Data |
---|---|---|
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 | #define _GNU_SOURCE | |
25 | #include "config.h" | |
26 | ||
27 | #include <alloca.h> | |
28 | #include <dirent.h> | |
29 | #include <errno.h> | |
30 | #include <fcntl.h> | |
31 | #include <grp.h> | |
32 | #include <poll.h> | |
33 | #include <signal.h> | |
34 | #include <stdio.h> | |
35 | #include <stdlib.h> | |
36 | #include <string.h> | |
37 | #include <unistd.h> | |
38 | #include <sys/file.h> | |
39 | #include <sys/mount.h> | |
40 | #include <sys/param.h> | |
41 | #include <sys/prctl.h> | |
42 | #include <sys/socket.h> | |
43 | #include <sys/stat.h> | |
44 | #include <sys/syscall.h> | |
45 | #include <sys/types.h> | |
46 | #include <sys/un.h> | |
47 | #include <sys/wait.h> | |
48 | ||
49 | #if HAVE_SYS_CAPABILITY_H | |
50 | #include <sys/capability.h> | |
51 | #endif | |
52 | ||
53 | #if !HAVE_DECL_PR_CAPBSET_DROP | |
54 | #define PR_CAPBSET_DROP 24 | |
55 | #endif | |
56 | ||
57 | #include "af_unix.h" | |
58 | #include "caps.h" | |
59 | #include "cgroup.h" | |
60 | #include "commands.h" | |
61 | #include "conf.h" | |
62 | #include "console.h" | |
63 | #include "error.h" | |
64 | #include "log.h" | |
65 | #include "lxclock.h" | |
66 | #include "lxcseccomp.h" | |
67 | #include "lxcutmp.h" | |
68 | #include "mainloop.h" | |
69 | #include "monitor.h" | |
70 | #include "namespace.h" | |
71 | #include "start.h" | |
72 | #include "sync.h" | |
73 | #include "utils.h" | |
74 | #include "bdev/bdev.h" | |
75 | #include "lsm/lsm.h" | |
76 | ||
77 | lxc_log_define(lxc_start, lxc); | |
78 | ||
79 | const struct ns_info ns_info[LXC_NS_MAX] = { | |
80 | [LXC_NS_MNT] = {"mnt", CLONE_NEWNS}, | |
81 | [LXC_NS_PID] = {"pid", CLONE_NEWPID}, | |
82 | [LXC_NS_UTS] = {"uts", CLONE_NEWUTS}, | |
83 | [LXC_NS_IPC] = {"ipc", CLONE_NEWIPC}, | |
84 | [LXC_NS_USER] = {"user", CLONE_NEWUSER}, | |
85 | [LXC_NS_NET] = {"net", CLONE_NEWNET} | |
86 | }; | |
87 | ||
88 | extern void mod_all_rdeps(struct lxc_container *c, bool inc); | |
89 | static bool do_destroy_container(struct lxc_conf *conf); | |
90 | static int lxc_rmdir_onedev_wrapper(void *data); | |
91 | static void lxc_destroy_container_on_signal(struct lxc_handler *handler, | |
92 | const char *name); | |
93 | ||
94 | static void print_top_failing_dir(const char *path) | |
95 | { | |
96 | size_t len = strlen(path); | |
97 | char *copy = alloca(len + 1), *p, *e, saved; | |
98 | strcpy(copy, path); | |
99 | ||
100 | p = copy; | |
101 | e = copy + len; | |
102 | while (p < e) { | |
103 | while (p < e && *p == '/') | |
104 | p++; | |
105 | while (p < e && *p != '/') | |
106 | p++; | |
107 | saved = *p; | |
108 | *p = '\0'; | |
109 | if (access(copy, X_OK)) { | |
110 | SYSERROR("could not access %s. Please grant it 'x' " \ | |
111 | "access, or add an ACL for the container root.", | |
112 | copy); | |
113 | return; | |
114 | } | |
115 | *p = saved; | |
116 | } | |
117 | } | |
118 | ||
119 | static void close_ns(int ns_fd[LXC_NS_MAX]) { | |
120 | int i; | |
121 | ||
122 | for (i = 0; i < LXC_NS_MAX; i++) { | |
123 | if (ns_fd[i] > -1) { | |
124 | close(ns_fd[i]); | |
125 | ns_fd[i] = -1; | |
126 | } | |
127 | } | |
128 | } | |
129 | ||
130 | /* | |
131 | * preserve_ns: open /proc/@pid/ns/@ns for each namespace specified | |
132 | * in clone_flags. | |
133 | * Return true on success, false on failure. On failure, leave an error | |
134 | * message in *errmsg, which caller must free. | |
135 | */ | |
136 | static bool preserve_ns(int ns_fd[LXC_NS_MAX], int clone_flags, pid_t pid, | |
137 | char **errmsg) | |
138 | { | |
139 | int i, ret; | |
140 | char path[MAXPATHLEN]; | |
141 | ||
142 | for (i = 0; i < LXC_NS_MAX; i++) | |
143 | ns_fd[i] = -1; | |
144 | ||
145 | snprintf(path, MAXPATHLEN, "/proc/%d/ns", pid); | |
146 | if (access(path, X_OK)) { | |
147 | if (asprintf(errmsg, "Kernel does not support setns.") == -1) | |
148 | *errmsg = NULL; | |
149 | return false; | |
150 | } | |
151 | ||
152 | for (i = 0; i < LXC_NS_MAX; i++) { | |
153 | if ((clone_flags & ns_info[i].clone_flag) == 0) | |
154 | continue; | |
155 | snprintf(path, MAXPATHLEN, "/proc/%d/ns/%s", pid, | |
156 | ns_info[i].proc_name); | |
157 | ns_fd[i] = open(path, O_RDONLY | O_CLOEXEC); | |
158 | if (ns_fd[i] < 0) | |
159 | goto error; | |
160 | } | |
161 | ||
162 | return true; | |
163 | ||
164 | error: | |
165 | if (errno == ENOENT) { | |
166 | ret = asprintf(errmsg, "Kernel does not support setns for %s", | |
167 | ns_info[i].proc_name); | |
168 | } else { | |
169 | ret = asprintf(errmsg, "Failed to open %s: %s", | |
170 | path, strerror(errno)); | |
171 | } | |
172 | if (ret == -1) | |
173 | *errmsg = NULL; | |
174 | close_ns(ns_fd); | |
175 | return false; | |
176 | } | |
177 | ||
178 | static int attach_ns(const int ns_fd[LXC_NS_MAX]) { | |
179 | int i; | |
180 | ||
181 | for (i = 0; i < LXC_NS_MAX; i++) { | |
182 | if (ns_fd[i] < 0) | |
183 | continue; | |
184 | ||
185 | if (setns(ns_fd[i], 0) != 0) | |
186 | goto error; | |
187 | } | |
188 | return 0; | |
189 | ||
190 | error: | |
191 | SYSERROR("failed to set namespace '%s'", ns_info[i].proc_name); | |
192 | return -1; | |
193 | } | |
194 | ||
195 | static int match_fd(int fd) | |
196 | { | |
197 | return (fd == 0 || fd == 1 || fd == 2); | |
198 | } | |
199 | ||
200 | /* | |
201 | * Check for any fds we need to close | |
202 | * * if fd_to_ignore != -1, then if we find that fd open we will ignore it. | |
203 | * * By default we warn about open fds we find. | |
204 | * * If closeall is true, we will close open fds. | |
205 | * * If lxc-start was passed "-C", then conf->close_all_fds will be true, | |
206 | * in which case we also close all open fds. | |
207 | * * A daemonized container will always pass closeall=true. | |
208 | */ | |
209 | int lxc_check_inherited(struct lxc_conf *conf, bool closeall, int fd_to_ignore) | |
210 | { | |
211 | struct dirent dirent, *direntp; | |
212 | int fd, fddir; | |
213 | DIR *dir; | |
214 | ||
215 | if (conf && conf->close_all_fds) | |
216 | closeall = true; | |
217 | ||
218 | restart: | |
219 | dir = opendir("/proc/self/fd"); | |
220 | if (!dir) { | |
221 | WARN("failed to open directory: %m"); | |
222 | return -1; | |
223 | } | |
224 | ||
225 | fddir = dirfd(dir); | |
226 | ||
227 | while (!readdir_r(dir, &dirent, &direntp)) { | |
228 | if (!direntp) | |
229 | break; | |
230 | ||
231 | if (!strcmp(direntp->d_name, ".")) | |
232 | continue; | |
233 | ||
234 | if (!strcmp(direntp->d_name, "..")) | |
235 | continue; | |
236 | ||
237 | fd = atoi(direntp->d_name); | |
238 | ||
239 | if (fd == fddir || fd == lxc_log_fd || fd == fd_to_ignore) | |
240 | continue; | |
241 | ||
242 | if (current_config && fd == current_config->logfd) | |
243 | continue; | |
244 | ||
245 | if (match_fd(fd)) | |
246 | continue; | |
247 | ||
248 | if (closeall) { | |
249 | close(fd); | |
250 | closedir(dir); | |
251 | INFO("closed inherited fd %d", fd); | |
252 | goto restart; | |
253 | } | |
254 | WARN("inherited fd %d", fd); | |
255 | } | |
256 | ||
257 | closedir(dir); /* cannot fail */ | |
258 | return 0; | |
259 | } | |
260 | ||
261 | static int setup_signal_fd(sigset_t *oldmask) | |
262 | { | |
263 | sigset_t mask; | |
264 | int fd; | |
265 | ||
266 | /* Block everything except serious error signals */ | |
267 | if (sigfillset(&mask) || | |
268 | sigdelset(&mask, SIGILL) || | |
269 | sigdelset(&mask, SIGSEGV) || | |
270 | sigdelset(&mask, SIGBUS) || | |
271 | sigdelset(&mask, SIGWINCH) || | |
272 | sigprocmask(SIG_BLOCK, &mask, oldmask)) { | |
273 | SYSERROR("failed to set signal mask"); | |
274 | return -1; | |
275 | } | |
276 | ||
277 | fd = signalfd(-1, &mask, 0); | |
278 | if (fd < 0) { | |
279 | SYSERROR("failed to create the signal fd"); | |
280 | return -1; | |
281 | } | |
282 | ||
283 | if (fcntl(fd, F_SETFD, FD_CLOEXEC)) { | |
284 | SYSERROR("failed to set sigfd to close-on-exec"); | |
285 | close(fd); | |
286 | return -1; | |
287 | } | |
288 | ||
289 | DEBUG("sigchild handler set"); | |
290 | ||
291 | return fd; | |
292 | } | |
293 | ||
294 | static int signal_handler(int fd, uint32_t events, void *data, | |
295 | struct lxc_epoll_descr *descr) | |
296 | { | |
297 | struct signalfd_siginfo siginfo; | |
298 | siginfo_t info; | |
299 | int ret; | |
300 | pid_t *pid = data; | |
301 | bool init_died = false; | |
302 | ||
303 | ret = read(fd, &siginfo, sizeof(siginfo)); | |
304 | if (ret < 0) { | |
305 | ERROR("failed to read signal info"); | |
306 | return -1; | |
307 | } | |
308 | ||
309 | if (ret != sizeof(siginfo)) { | |
310 | ERROR("unexpected siginfo size"); | |
311 | return -1; | |
312 | } | |
313 | ||
314 | // check whether init is running | |
315 | info.si_pid = 0; | |
316 | ret = waitid(P_PID, *pid, &info, WEXITED | WNOWAIT | WNOHANG); | |
317 | if (ret == 0 && info.si_pid == *pid) { | |
318 | init_died = true; | |
319 | } | |
320 | ||
321 | if (siginfo.ssi_signo != SIGCHLD) { | |
322 | kill(*pid, siginfo.ssi_signo); | |
323 | INFO("forwarded signal %d to pid %d", siginfo.ssi_signo, *pid); | |
324 | return init_died ? 1 : 0; | |
325 | } | |
326 | ||
327 | if (siginfo.ssi_code == CLD_STOPPED || | |
328 | siginfo.ssi_code == CLD_CONTINUED) { | |
329 | INFO("container init process was stopped/continued"); | |
330 | return init_died ? 1 : 0; | |
331 | } | |
332 | ||
333 | /* more robustness, protect ourself from a SIGCHLD sent | |
334 | * by a process different from the container init | |
335 | */ | |
336 | if (siginfo.ssi_pid != *pid) { | |
337 | WARN("invalid pid for SIGCHLD"); | |
338 | return init_died ? 1 : 0; | |
339 | } | |
340 | ||
341 | DEBUG("container init process exited"); | |
342 | return 1; | |
343 | } | |
344 | ||
345 | int lxc_set_state(const char *name, struct lxc_handler *handler, lxc_state_t state) | |
346 | { | |
347 | handler->state = state; | |
348 | lxc_monitor_send_state(name, state, handler->lxcpath); | |
349 | return 0; | |
350 | } | |
351 | ||
352 | int lxc_poll(const char *name, struct lxc_handler *handler) | |
353 | { | |
354 | int sigfd = handler->sigfd; | |
355 | int pid = handler->pid; | |
356 | struct lxc_epoll_descr descr; | |
357 | ||
358 | if (lxc_mainloop_open(&descr)) { | |
359 | ERROR("failed to create mainloop"); | |
360 | goto out_sigfd; | |
361 | } | |
362 | ||
363 | if (lxc_mainloop_add_handler(&descr, sigfd, signal_handler, &pid)) { | |
364 | ERROR("failed to add handler for the signal"); | |
365 | goto out_mainloop_open; | |
366 | } | |
367 | ||
368 | if (lxc_console_mainloop_add(&descr, handler->conf)) { | |
369 | ERROR("failed to add console handler to mainloop"); | |
370 | goto out_mainloop_open; | |
371 | } | |
372 | ||
373 | if (lxc_cmd_mainloop_add(name, &descr, handler)) { | |
374 | ERROR("failed to add command handler to mainloop"); | |
375 | goto out_mainloop_open; | |
376 | } | |
377 | ||
378 | if (handler->conf->need_utmp_watch) { | |
379 | #if HAVE_SYS_CAPABILITY_H | |
380 | if (lxc_utmp_mainloop_add(&descr, handler)) { | |
381 | ERROR("failed to add utmp handler to mainloop"); | |
382 | goto out_mainloop_open; | |
383 | } | |
384 | #else | |
385 | DEBUG("not starting utmp handler as cap_sys_boot cannot be dropped without capabilities support"); | |
386 | #endif | |
387 | } | |
388 | ||
389 | return lxc_mainloop(&descr, -1); | |
390 | ||
391 | out_mainloop_open: | |
392 | lxc_mainloop_close(&descr); | |
393 | out_sigfd: | |
394 | close(sigfd); | |
395 | return -1; | |
396 | } | |
397 | ||
398 | struct lxc_handler *lxc_init(const char *name, struct lxc_conf *conf, const char *lxcpath) | |
399 | { | |
400 | int i; | |
401 | struct lxc_handler *handler; | |
402 | ||
403 | handler = malloc(sizeof(*handler)); | |
404 | if (!handler) | |
405 | return NULL; | |
406 | ||
407 | memset(handler, 0, sizeof(*handler)); | |
408 | ||
409 | handler->ttysock[0] = handler->ttysock[1] = -1; | |
410 | handler->conf = conf; | |
411 | handler->lxcpath = lxcpath; | |
412 | handler->pinfd = -1; | |
413 | ||
414 | for (i = 0; i < LXC_NS_MAX; i++) | |
415 | handler->nsfd[i] = -1; | |
416 | ||
417 | lsm_init(); | |
418 | ||
419 | handler->name = strdup(name); | |
420 | if (!handler->name) { | |
421 | ERROR("failed to allocate memory"); | |
422 | goto out_free; | |
423 | } | |
424 | ||
425 | if (lxc_cmd_init(name, handler, lxcpath)) | |
426 | goto out_free_name; | |
427 | ||
428 | if (lxc_read_seccomp_config(conf) != 0) { | |
429 | ERROR("failed loading seccomp policy"); | |
430 | goto out_close_maincmd_fd; | |
431 | } | |
432 | ||
433 | /* Begin by setting the state to STARTING */ | |
434 | if (lxc_set_state(name, handler, STARTING)) { | |
435 | ERROR("failed to set state '%s'", lxc_state2str(STARTING)); | |
436 | goto out_close_maincmd_fd; | |
437 | } | |
438 | ||
439 | /* Start of environment variable setup for hooks */ | |
440 | if (name && setenv("LXC_NAME", name, 1)) { | |
441 | SYSERROR("failed to set environment variable for container name"); | |
442 | } | |
443 | if (conf->rcfile && setenv("LXC_CONFIG_FILE", conf->rcfile, 1)) { | |
444 | SYSERROR("failed to set environment variable for config path"); | |
445 | } | |
446 | if (conf->rootfs.mount && setenv("LXC_ROOTFS_MOUNT", conf->rootfs.mount, 1)) { | |
447 | SYSERROR("failed to set environment variable for rootfs mount"); | |
448 | } | |
449 | if (conf->rootfs.path && setenv("LXC_ROOTFS_PATH", conf->rootfs.path, 1)) { | |
450 | SYSERROR("failed to set environment variable for rootfs mount"); | |
451 | } | |
452 | if (conf->console.path && setenv("LXC_CONSOLE", conf->console.path, 1)) { | |
453 | SYSERROR("failed to set environment variable for console path"); | |
454 | } | |
455 | if (conf->console.log_path && setenv("LXC_CONSOLE_LOGPATH", conf->console.log_path, 1)) { | |
456 | SYSERROR("failed to set environment variable for console log"); | |
457 | } | |
458 | if (setenv("LXC_CGNS_AWARE", "1", 1)) { | |
459 | SYSERROR("failed to set LXC_CGNS_AWARE environment variable"); | |
460 | } | |
461 | /* End of environment variable setup for hooks */ | |
462 | ||
463 | if (run_lxc_hooks(name, "pre-start", conf, handler->lxcpath, NULL)) { | |
464 | ERROR("failed to run pre-start hooks for container '%s'.", name); | |
465 | goto out_aborting; | |
466 | } | |
467 | ||
468 | /* the signal fd has to be created before forking otherwise | |
469 | * if the child process exits before we setup the signal fd, | |
470 | * the event will be lost and the command will be stuck */ | |
471 | handler->sigfd = setup_signal_fd(&handler->oldmask); | |
472 | if (handler->sigfd < 0) { | |
473 | ERROR("failed to set sigchild fd handler"); | |
474 | goto out_delete_tty; | |
475 | } | |
476 | ||
477 | /* do this after setting up signals since it might unblock SIGWINCH */ | |
478 | if (lxc_console_create(conf)) { | |
479 | ERROR("failed to create console"); | |
480 | goto out_restore_sigmask; | |
481 | } | |
482 | ||
483 | if (ttys_shift_ids(conf) < 0) { | |
484 | ERROR("Failed to shift tty into container"); | |
485 | goto out_restore_sigmask; | |
486 | } | |
487 | ||
488 | INFO("'%s' is initialized", name); | |
489 | return handler; | |
490 | ||
491 | out_restore_sigmask: | |
492 | sigprocmask(SIG_SETMASK, &handler->oldmask, NULL); | |
493 | out_delete_tty: | |
494 | lxc_delete_tty(&conf->tty_info); | |
495 | out_aborting: | |
496 | lxc_set_state(name, handler, ABORTING); | |
497 | out_close_maincmd_fd: | |
498 | close(conf->maincmd_fd); | |
499 | conf->maincmd_fd = -1; | |
500 | out_free_name: | |
501 | free(handler->name); | |
502 | handler->name = NULL; | |
503 | out_free: | |
504 | free(handler); | |
505 | return NULL; | |
506 | } | |
507 | ||
508 | void lxc_fini(const char *name, struct lxc_handler *handler) | |
509 | { | |
510 | int i, rc; | |
511 | pid_t self = getpid(); | |
512 | char *namespaces[LXC_NS_MAX+1]; | |
513 | size_t namespace_count = 0; | |
514 | ||
515 | /* The STOPPING state is there for future cleanup code | |
516 | * which can take awhile | |
517 | */ | |
518 | lxc_set_state(name, handler, STOPPING); | |
519 | ||
520 | for (i = 0; i < LXC_NS_MAX; i++) { | |
521 | if (handler->nsfd[i] != -1) { | |
522 | rc = asprintf(&namespaces[namespace_count], "%s:/proc/%d/fd/%d", | |
523 | ns_info[i].proc_name, self, handler->nsfd[i]); | |
524 | if (rc == -1) { | |
525 | SYSERROR("failed to allocate memory"); | |
526 | break; | |
527 | } | |
528 | ++namespace_count; | |
529 | } | |
530 | } | |
531 | namespaces[namespace_count] = NULL; | |
532 | ||
533 | if (handler->conf->reboot && setenv("LXC_TARGET", "reboot", 1)) { | |
534 | SYSERROR("failed to set environment variable for stop target"); | |
535 | } | |
536 | if (!handler->conf->reboot && setenv("LXC_TARGET", "stop", 1)) { | |
537 | SYSERROR("failed to set environment variable for stop target"); | |
538 | } | |
539 | ||
540 | if (run_lxc_hooks(name, "stop", handler->conf, handler->lxcpath, namespaces)) | |
541 | ERROR("failed to run stop hooks for container '%s'.", name); | |
542 | ||
543 | while (namespace_count--) | |
544 | free(namespaces[namespace_count]); | |
545 | for (i = 0; i < LXC_NS_MAX; i++) { | |
546 | if (handler->nsfd[i] != -1) { | |
547 | close(handler->nsfd[i]); | |
548 | handler->nsfd[i] = -1; | |
549 | } | |
550 | } | |
551 | lxc_set_state(name, handler, STOPPED); | |
552 | ||
553 | if (run_lxc_hooks(name, "post-stop", handler->conf, handler->lxcpath, NULL)) { | |
554 | ERROR("failed to run post-stop hooks for container '%s'.", name); | |
555 | if (handler->conf->reboot) { | |
556 | WARN("Container will be stopped instead of rebooted."); | |
557 | handler->conf->reboot = 0; | |
558 | setenv("LXC_TARGET", "stop", 1); | |
559 | } | |
560 | } | |
561 | ||
562 | /* reset mask set by setup_signal_fd */ | |
563 | if (sigprocmask(SIG_SETMASK, &handler->oldmask, NULL)) | |
564 | WARN("failed to restore sigprocmask"); | |
565 | ||
566 | lxc_console_delete(&handler->conf->console); | |
567 | lxc_delete_tty(&handler->conf->tty_info); | |
568 | close(handler->conf->maincmd_fd); | |
569 | handler->conf->maincmd_fd = -1; | |
570 | free(handler->name); | |
571 | if (handler->ttysock[0] != -1) { | |
572 | close(handler->ttysock[0]); | |
573 | close(handler->ttysock[1]); | |
574 | } | |
575 | ||
576 | if (handler->conf->ephemeral == 1 && handler->conf->reboot != 1) | |
577 | lxc_destroy_container_on_signal(handler, name); | |
578 | ||
579 | cgroup_destroy(handler); | |
580 | free(handler); | |
581 | } | |
582 | ||
583 | void lxc_abort(const char *name, struct lxc_handler *handler) | |
584 | { | |
585 | int ret, status; | |
586 | ||
587 | lxc_set_state(name, handler, ABORTING); | |
588 | if (handler->pid > 0) | |
589 | kill(handler->pid, SIGKILL); | |
590 | while ((ret = waitpid(-1, &status, 0)) > 0) ; | |
591 | } | |
592 | ||
593 | #include <sys/reboot.h> | |
594 | #include <linux/reboot.h> | |
595 | ||
596 | /* | |
597 | * reboot(LINUX_REBOOT_CMD_CAD_ON) will return -EINVAL | |
598 | * in a child pid namespace if container reboot support exists. | |
599 | * Otherwise, it will either succeed or return -EPERM. | |
600 | */ | |
601 | static int container_reboot_supported(void *arg) | |
602 | { | |
603 | int *cmd = arg; | |
604 | int ret; | |
605 | ||
606 | ret = reboot(*cmd); | |
607 | if (ret == -1 && errno == EINVAL) | |
608 | return 1; | |
609 | return 0; | |
610 | } | |
611 | ||
612 | static int must_drop_cap_sys_boot(struct lxc_conf *conf) | |
613 | { | |
614 | FILE *f; | |
615 | int ret, cmd, v, flags; | |
616 | long stack_size = 4096; | |
617 | void *stack = alloca(stack_size); | |
618 | int status; | |
619 | pid_t pid; | |
620 | ||
621 | f = fopen("/proc/sys/kernel/ctrl-alt-del", "r"); | |
622 | if (!f) { | |
623 | DEBUG("failed to open /proc/sys/kernel/ctrl-alt-del"); | |
624 | return 1; | |
625 | } | |
626 | ||
627 | ret = fscanf(f, "%d", &v); | |
628 | fclose(f); | |
629 | if (ret != 1) { | |
630 | DEBUG("Failed to read /proc/sys/kernel/ctrl-alt-del"); | |
631 | return 1; | |
632 | } | |
633 | cmd = v ? LINUX_REBOOT_CMD_CAD_ON : LINUX_REBOOT_CMD_CAD_OFF; | |
634 | ||
635 | flags = CLONE_NEWPID | SIGCHLD; | |
636 | if (!lxc_list_empty(&conf->id_map)) | |
637 | flags |= CLONE_NEWUSER; | |
638 | ||
639 | #ifdef __ia64__ | |
640 | pid = __clone2(container_reboot_supported, stack, stack_size, flags, &cmd); | |
641 | #else | |
642 | stack += stack_size; | |
643 | pid = clone(container_reboot_supported, stack, flags, &cmd); | |
644 | #endif | |
645 | if (pid < 0) { | |
646 | if (flags & CLONE_NEWUSER) | |
647 | ERROR("failed to clone (%#x): %s (includes CLONE_NEWUSER)", flags, strerror(errno)); | |
648 | else | |
649 | ERROR("failed to clone (%#x): %s", flags, strerror(errno)); | |
650 | return -1; | |
651 | } | |
652 | if (wait(&status) < 0) { | |
653 | SYSERROR("unexpected wait error: %m"); | |
654 | return -1; | |
655 | } | |
656 | ||
657 | if (WEXITSTATUS(status) != 1) | |
658 | return 1; | |
659 | ||
660 | return 0; | |
661 | } | |
662 | ||
663 | /* | |
664 | * netpipe is used in the unprivileged case to transfer the ifindexes | |
665 | * from parent to child | |
666 | */ | |
667 | static int netpipe = -1; | |
668 | ||
669 | static inline int count_veths(struct lxc_list *network) | |
670 | { | |
671 | struct lxc_list *iterator; | |
672 | struct lxc_netdev *netdev; | |
673 | int count = 0; | |
674 | ||
675 | lxc_list_for_each(iterator, network) { | |
676 | netdev = iterator->elem; | |
677 | if (netdev->type != LXC_NET_VETH) | |
678 | continue; | |
679 | count++; | |
680 | } | |
681 | return count; | |
682 | } | |
683 | ||
684 | static int read_unpriv_netifindex(struct lxc_list *network) | |
685 | { | |
686 | struct lxc_list *iterator; | |
687 | struct lxc_netdev *netdev; | |
688 | ||
689 | if (netpipe == -1) | |
690 | return 0; | |
691 | lxc_list_for_each(iterator, network) { | |
692 | netdev = iterator->elem; | |
693 | if (netdev->type != LXC_NET_VETH) | |
694 | continue; | |
695 | if (!(netdev->name = malloc(IFNAMSIZ))) { | |
696 | ERROR("Out of memory"); | |
697 | close(netpipe); | |
698 | return -1; | |
699 | } | |
700 | if (read(netpipe, netdev->name, IFNAMSIZ) != IFNAMSIZ) { | |
701 | close(netpipe); | |
702 | return -1; | |
703 | } | |
704 | } | |
705 | close(netpipe); | |
706 | return 0; | |
707 | } | |
708 | ||
709 | static int do_start(void *data) | |
710 | { | |
711 | struct lxc_list *iterator; | |
712 | struct lxc_handler *handler = data; | |
713 | int devnull_fd = -1, ret; | |
714 | char path[PATH_MAX]; | |
715 | ||
716 | if (sigprocmask(SIG_SETMASK, &handler->oldmask, NULL)) { | |
717 | SYSERROR("failed to set sigprocmask"); | |
718 | return -1; | |
719 | } | |
720 | ||
721 | /* This prctl must be before the synchro, so if the parent | |
722 | * dies before we set the parent death signal, we will detect | |
723 | * its death with the synchro right after, otherwise we have | |
724 | * a window where the parent can exit before we set the pdeath | |
725 | * signal leading to a unsupervized container. | |
726 | */ | |
727 | if (prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0)) { | |
728 | SYSERROR("failed to set pdeath signal"); | |
729 | return -1; | |
730 | } | |
731 | ||
732 | lxc_sync_fini_parent(handler); | |
733 | ||
734 | /* don't leak the pinfd to the container */ | |
735 | if (handler->pinfd >= 0) { | |
736 | close(handler->pinfd); | |
737 | } | |
738 | ||
739 | /* Tell the parent task it can begin to configure the | |
740 | * container and wait for it to finish | |
741 | */ | |
742 | if (lxc_sync_barrier_parent(handler, LXC_SYNC_CONFIGURE)) | |
743 | return -1; | |
744 | ||
745 | if (read_unpriv_netifindex(&handler->conf->network) < 0) | |
746 | goto out_warn_father; | |
747 | ||
748 | /* | |
749 | * if we are in a new user namespace, become root there to have | |
750 | * privilege over our namespace. When using lxc-execute we default to root, | |
751 | * but this can be overriden using the lxc.init_uid and lxc.init_gid | |
752 | * configuration options. | |
753 | */ | |
754 | if (!lxc_list_empty(&handler->conf->id_map)) { | |
755 | gid_t new_gid = 0; | |
756 | if (handler->conf->is_execute && handler->conf->init_gid) | |
757 | new_gid = handler->conf->init_gid; | |
758 | ||
759 | uid_t new_uid = 0; | |
760 | if (handler->conf->is_execute && handler->conf->init_uid) | |
761 | new_uid = handler->conf->init_uid; | |
762 | ||
763 | NOTICE("switching to gid/uid %d/%d in new user namespace", new_gid, new_uid); | |
764 | if (setgid(new_gid)) { | |
765 | SYSERROR("setgid"); | |
766 | goto out_warn_father; | |
767 | } | |
768 | if (setuid(new_uid)) { | |
769 | SYSERROR("setuid"); | |
770 | goto out_warn_father; | |
771 | } | |
772 | if (setgroups(0, NULL)) { | |
773 | SYSERROR("setgroups"); | |
774 | goto out_warn_father; | |
775 | } | |
776 | } | |
777 | ||
778 | if (access(handler->lxcpath, X_OK)) { | |
779 | print_top_failing_dir(handler->lxcpath); | |
780 | goto out_warn_father; | |
781 | } | |
782 | ||
783 | #if HAVE_SYS_CAPABILITY_H | |
784 | if (handler->conf->need_utmp_watch) { | |
785 | if (prctl(PR_CAPBSET_DROP, CAP_SYS_BOOT, 0, 0, 0)) { | |
786 | SYSERROR("failed to remove CAP_SYS_BOOT capability"); | |
787 | goto out_warn_father; | |
788 | } | |
789 | DEBUG("Dropped cap_sys_boot"); | |
790 | } | |
791 | #endif | |
792 | ||
793 | ret = snprintf(path, sizeof(path), "%s/dev/null", handler->conf->rootfs.mount); | |
794 | if (ret < 0 || ret >= sizeof(path)) { | |
795 | SYSERROR("sprintf'd too many chars"); | |
796 | goto out_warn_father; | |
797 | } | |
798 | ||
799 | /* In order to checkpoint restore, we need to have everything in the | |
800 | * same mount namespace. However, some containers may not have a | |
801 | * reasonable /dev (in particular, they may not have /dev/null), so we | |
802 | * can't set init's std fds to /dev/null by opening it from inside the | |
803 | * container. | |
804 | * | |
805 | * If that's the case, fall back to using the host's /dev/null. This | |
806 | * means that migration won't work, but at least we won't spew output | |
807 | * where it isn't wanted. | |
808 | */ | |
809 | if (handler->backgrounded && !handler->conf->autodev && access(path, F_OK) < 0) { | |
810 | devnull_fd = open_devnull(); | |
811 | ||
812 | if (devnull_fd < 0) | |
813 | goto out_warn_father; | |
814 | WARN("using host's /dev/null for container init's std fds, migraiton won't work"); | |
815 | } | |
816 | ||
817 | /* Setup the container, ip, names, utsname, ... */ | |
818 | if (lxc_setup(handler)) { | |
819 | ERROR("failed to setup the container"); | |
820 | goto out_warn_father; | |
821 | } | |
822 | ||
823 | /* ask father to setup cgroups and wait for him to finish */ | |
824 | if (lxc_sync_barrier_parent(handler, LXC_SYNC_CGROUP)) | |
825 | goto out_error; | |
826 | ||
827 | /* Set the label to change to when we exec(2) the container's init */ | |
828 | if (lsm_process_label_set(NULL, handler->conf, 1, 1) < 0) | |
829 | goto out_warn_father; | |
830 | ||
831 | /* Some init's such as busybox will set sane tty settings on stdin, | |
832 | * stdout, stderr which it thinks is the console. We already set them | |
833 | * the way we wanted on the real terminal, and we want init to do its | |
834 | * setup on its console ie. the pty allocated in lxc_console_create() | |
835 | * so make sure that that pty is stdin,stdout,stderr. | |
836 | */ | |
837 | if (lxc_console_set_stdfds(handler->conf->console.slave) < 0) | |
838 | goto out_warn_father; | |
839 | ||
840 | /* If we mounted a temporary proc, then unmount it now */ | |
841 | tmp_proc_unmount(handler->conf); | |
842 | ||
843 | if (lxc_seccomp_load(handler->conf) != 0) | |
844 | goto out_warn_father; | |
845 | ||
846 | if (run_lxc_hooks(handler->name, "start", handler->conf, handler->lxcpath, NULL)) { | |
847 | ERROR("failed to run start hooks for container '%s'.", handler->name); | |
848 | goto out_warn_father; | |
849 | } | |
850 | ||
851 | /* The clearenv() and putenv() calls have been moved here | |
852 | * to allow us to use environment variables passed to the various | |
853 | * hooks, such as the start hook above. Not all of the | |
854 | * variables like CONFIG_PATH or ROOTFS are valid in this | |
855 | * context but others are. */ | |
856 | if (clearenv()) { | |
857 | SYSERROR("failed to clear environment"); | |
858 | /* don't error out though */ | |
859 | } | |
860 | ||
861 | lxc_list_for_each(iterator, &handler->conf->environment) { | |
862 | if (putenv((char *)iterator->elem)) { | |
863 | SYSERROR("failed to set environment variable '%s'", (char *)iterator->elem); | |
864 | goto out_warn_father; | |
865 | } | |
866 | } | |
867 | ||
868 | if (putenv("container=lxc")) { | |
869 | SYSERROR("failed to set environment variable 'container=lxc'"); | |
870 | goto out_warn_father; | |
871 | } | |
872 | ||
873 | if (handler->conf->pty_names) { | |
874 | if (putenv(handler->conf->pty_names)) { | |
875 | SYSERROR("failed to set environment variable for container ptys"); | |
876 | goto out_warn_father; | |
877 | } | |
878 | } | |
879 | ||
880 | close(handler->sigfd); | |
881 | ||
882 | if (devnull_fd < 0) { | |
883 | devnull_fd = open_devnull(); | |
884 | ||
885 | if (devnull_fd < 0) | |
886 | goto out_warn_father; | |
887 | } | |
888 | ||
889 | if (handler->backgrounded && set_stdfds(devnull_fd)) | |
890 | goto out_warn_father; | |
891 | ||
892 | if (devnull_fd >= 0) { | |
893 | close(devnull_fd); | |
894 | devnull_fd = -1; | |
895 | } | |
896 | ||
897 | if (cgns_supported() && unshare(CLONE_NEWCGROUP) != 0) { | |
898 | SYSERROR("Failed to unshare cgroup namespace"); | |
899 | goto out_warn_father; | |
900 | } | |
901 | ||
902 | setsid(); | |
903 | ||
904 | /* after this call, we are in error because this | |
905 | * ops should not return as it execs */ | |
906 | handler->ops->start(handler, handler->data); | |
907 | ||
908 | out_warn_father: | |
909 | /* we want the parent to know something went wrong, so we return a special | |
910 | * error code. */ | |
911 | lxc_sync_wake_parent(handler, LXC_SYNC_ERROR); | |
912 | ||
913 | out_error: | |
914 | if (devnull_fd >= 0) | |
915 | close(devnull_fd); | |
916 | ||
917 | return -1; | |
918 | } | |
919 | ||
920 | static int save_phys_nics(struct lxc_conf *conf) | |
921 | { | |
922 | struct lxc_list *iterator; | |
923 | int am_root = (getuid() == 0); | |
924 | ||
925 | if (!am_root) | |
926 | return 0; | |
927 | ||
928 | lxc_list_for_each(iterator, &conf->network) { | |
929 | struct lxc_netdev *netdev = iterator->elem; | |
930 | ||
931 | if (netdev->type != LXC_NET_PHYS) | |
932 | continue; | |
933 | conf->saved_nics = realloc(conf->saved_nics, | |
934 | (conf->num_savednics+1)*sizeof(struct saved_nic)); | |
935 | if (!conf->saved_nics) { | |
936 | SYSERROR("failed to allocate memory"); | |
937 | return -1; | |
938 | } | |
939 | conf->saved_nics[conf->num_savednics].ifindex = netdev->ifindex; | |
940 | conf->saved_nics[conf->num_savednics].orig_name = strdup(netdev->link); | |
941 | if (!conf->saved_nics[conf->num_savednics].orig_name) { | |
942 | SYSERROR("failed to allocate memory"); | |
943 | return -1; | |
944 | } | |
945 | INFO("stored saved_nic #%d idx %d name %s", conf->num_savednics, | |
946 | conf->saved_nics[conf->num_savednics].ifindex, | |
947 | conf->saved_nics[conf->num_savednics].orig_name); | |
948 | conf->num_savednics++; | |
949 | } | |
950 | ||
951 | return 0; | |
952 | } | |
953 | ||
954 | static int recv_fd(int sock, int *fd) | |
955 | { | |
956 | if (lxc_abstract_unix_recv_fd(sock, fd, NULL, 0) < 0) { | |
957 | SYSERROR("Error receiving tty fd from child"); | |
958 | return -1; | |
959 | } | |
960 | if (*fd == -1) | |
961 | return -1; | |
962 | return 0; | |
963 | } | |
964 | ||
965 | static int recv_ttys_from_child(struct lxc_handler *handler) | |
966 | { | |
967 | struct lxc_conf *conf = handler->conf; | |
968 | int i, sock = handler->ttysock[1]; | |
969 | struct lxc_tty_info *tty_info = &conf->tty_info; | |
970 | ||
971 | if (!conf->tty) | |
972 | return 0; | |
973 | ||
974 | tty_info->pty_info = malloc(sizeof(*tty_info->pty_info)*conf->tty); | |
975 | if (!tty_info->pty_info) { | |
976 | SYSERROR("failed to allocate pty_info"); | |
977 | return -1; | |
978 | } | |
979 | ||
980 | for (i = 0; i < conf->tty; i++) { | |
981 | struct lxc_pty_info *pty_info = &tty_info->pty_info[i]; | |
982 | pty_info->busy = 0; | |
983 | if (recv_fd(sock, &pty_info->slave) < 0 || | |
984 | recv_fd(sock, &pty_info->master) < 0) { | |
985 | ERROR("Error receiving tty info from child"); | |
986 | return -1; | |
987 | } | |
988 | } | |
989 | tty_info->nbtty = conf->tty; | |
990 | ||
991 | return 0; | |
992 | } | |
993 | ||
994 | void resolve_clone_flags(struct lxc_handler *handler) | |
995 | { | |
996 | handler->clone_flags = CLONE_NEWPID | CLONE_NEWNS; | |
997 | ||
998 | if (!lxc_list_empty(&handler->conf->id_map)) { | |
999 | INFO("Cloning a new user namespace"); | |
1000 | handler->clone_flags |= CLONE_NEWUSER; | |
1001 | } | |
1002 | ||
1003 | if (handler->conf->inherit_ns_fd[LXC_NS_NET] == -1) { | |
1004 | if (!lxc_requests_empty_network(handler)) | |
1005 | handler->clone_flags |= CLONE_NEWNET; | |
1006 | } else { | |
1007 | INFO("Inheriting a net namespace"); | |
1008 | } | |
1009 | ||
1010 | if (handler->conf->inherit_ns_fd[LXC_NS_IPC] == -1) { | |
1011 | handler->clone_flags |= CLONE_NEWIPC; | |
1012 | } else { | |
1013 | INFO("Inheriting an IPC namespace"); | |
1014 | } | |
1015 | ||
1016 | if (handler->conf->inherit_ns_fd[LXC_NS_UTS] == -1) { | |
1017 | handler->clone_flags |= CLONE_NEWUTS; | |
1018 | } else { | |
1019 | INFO("Inheriting a UTS namespace"); | |
1020 | } | |
1021 | } | |
1022 | ||
1023 | static int lxc_spawn(struct lxc_handler *handler) | |
1024 | { | |
1025 | int failed_before_rename = 0; | |
1026 | const char *name = handler->name; | |
1027 | char *errmsg = NULL; | |
1028 | bool cgroups_connected = false; | |
1029 | int saved_ns_fd[LXC_NS_MAX]; | |
1030 | int preserve_mask = 0, i; | |
1031 | int netpipepair[2], nveths; | |
1032 | ||
1033 | netpipe = -1; | |
1034 | ||
1035 | for (i = 0; i < LXC_NS_MAX; i++) | |
1036 | if (handler->conf->inherit_ns_fd[i] != -1) | |
1037 | preserve_mask |= ns_info[i].clone_flag; | |
1038 | ||
1039 | if (lxc_sync_init(handler)) | |
1040 | return -1; | |
1041 | ||
1042 | if (socketpair(AF_UNIX, SOCK_DGRAM, 0, handler->ttysock) < 0) { | |
1043 | lxc_sync_fini(handler); | |
1044 | return -1; | |
1045 | } | |
1046 | ||
1047 | resolve_clone_flags(handler); | |
1048 | ||
1049 | if (handler->clone_flags & CLONE_NEWNET) { | |
1050 | if (!lxc_list_empty(&handler->conf->network)) { | |
1051 | ||
1052 | /* Find gateway addresses from the link device, which is | |
1053 | * no longer accessible inside the container. Do this | |
1054 | * before creating network interfaces, since goto | |
1055 | * out_delete_net does not work before lxc_clone. */ | |
1056 | if (lxc_find_gateway_addresses(handler)) { | |
1057 | ERROR("failed to find gateway addresses"); | |
1058 | lxc_sync_fini(handler); | |
1059 | return -1; | |
1060 | } | |
1061 | ||
1062 | /* that should be done before the clone because we will | |
1063 | * fill the netdev index and use them in the child | |
1064 | */ | |
1065 | if (lxc_create_network(handler)) { | |
1066 | ERROR("failed to create the network"); | |
1067 | lxc_sync_fini(handler); | |
1068 | return -1; | |
1069 | } | |
1070 | } | |
1071 | ||
1072 | if (save_phys_nics(handler->conf)) { | |
1073 | ERROR("failed to save physical nic info"); | |
1074 | goto out_abort; | |
1075 | } | |
1076 | } | |
1077 | ||
1078 | if (!cgroup_init(handler)) { | |
1079 | ERROR("failed initializing cgroup support"); | |
1080 | goto out_delete_net; | |
1081 | } | |
1082 | ||
1083 | cgroups_connected = true; | |
1084 | ||
1085 | if (!cgroup_create(handler)) { | |
1086 | ERROR("failed creating cgroups"); | |
1087 | goto out_delete_net; | |
1088 | } | |
1089 | ||
1090 | /* | |
1091 | * if the rootfs is not a blockdev, prevent the container from | |
1092 | * marking it readonly. | |
1093 | * | |
1094 | * if the container is unprivileged then skip rootfs pinning | |
1095 | */ | |
1096 | if (lxc_list_empty(&handler->conf->id_map)) { | |
1097 | handler->pinfd = pin_rootfs(handler->conf->rootfs.path); | |
1098 | if (handler->pinfd == -1) | |
1099 | INFO("failed to pin the container's rootfs"); | |
1100 | } | |
1101 | ||
1102 | if (!preserve_ns(saved_ns_fd, preserve_mask, getpid(), &errmsg)) { | |
1103 | SYSERROR("Failed to preserve requested namespaces: %s", | |
1104 | errmsg ? errmsg : "(Out of memory)"); | |
1105 | free(errmsg); | |
1106 | goto out_delete_net; | |
1107 | } | |
1108 | if (attach_ns(handler->conf->inherit_ns_fd) < 0) | |
1109 | goto out_delete_net; | |
1110 | ||
1111 | if (am_unpriv() && (nveths = count_veths(&handler->conf->network))) { | |
1112 | if (pipe(netpipepair) < 0) { | |
1113 | SYSERROR("Error creating pipe"); | |
1114 | goto out_delete_net; | |
1115 | } | |
1116 | /* store netpipe in the global var for do_start's use */ | |
1117 | netpipe = netpipepair[0]; | |
1118 | } | |
1119 | ||
1120 | /* Create a process in a new set of namespaces */ | |
1121 | handler->pid = lxc_clone(do_start, handler, handler->clone_flags); | |
1122 | if (handler->pid < 0) { | |
1123 | SYSERROR("failed to fork into a new namespace"); | |
1124 | goto out_delete_net; | |
1125 | } | |
1126 | ||
1127 | if (!preserve_ns(handler->nsfd, handler->clone_flags | preserve_mask, handler->pid, &errmsg)) { | |
1128 | INFO("Failed to store namespace references for stop hook: %s", | |
1129 | errmsg ? errmsg : "(Out of memory)"); | |
1130 | free(errmsg); | |
1131 | } | |
1132 | ||
1133 | if (attach_ns(saved_ns_fd)) | |
1134 | WARN("failed to restore saved namespaces"); | |
1135 | ||
1136 | lxc_sync_fini_child(handler); | |
1137 | ||
1138 | if (lxc_sync_wait_child(handler, LXC_SYNC_CONFIGURE)) | |
1139 | failed_before_rename = 1; | |
1140 | ||
1141 | if (!cgroup_create_legacy(handler)) { | |
1142 | ERROR("failed to setup the legacy cgroups for %s", name); | |
1143 | goto out_delete_net; | |
1144 | } | |
1145 | if (!cgroup_setup_limits(handler, false)) { | |
1146 | ERROR("failed to setup the cgroup limits for '%s'", name); | |
1147 | goto out_delete_net; | |
1148 | } | |
1149 | ||
1150 | if (!cgroup_enter(handler)) | |
1151 | goto out_delete_net; | |
1152 | ||
1153 | if (!cgroup_chown(handler)) | |
1154 | goto out_delete_net; | |
1155 | ||
1156 | if (failed_before_rename) | |
1157 | goto out_delete_net; | |
1158 | ||
1159 | /* Create the network configuration */ | |
1160 | if (handler->clone_flags & CLONE_NEWNET) { | |
1161 | if (lxc_assign_network(handler->lxcpath, handler->name, | |
1162 | &handler->conf->network, handler->pid)) { | |
1163 | ERROR("failed to create the configured network"); | |
1164 | goto out_delete_net; | |
1165 | } | |
1166 | } | |
1167 | ||
1168 | if (netpipe != -1) { | |
1169 | struct lxc_list *iterator; | |
1170 | struct lxc_netdev *netdev; | |
1171 | ||
1172 | close(netpipe); | |
1173 | lxc_list_for_each(iterator, &handler->conf->network) { | |
1174 | netdev = iterator->elem; | |
1175 | if (netdev->type != LXC_NET_VETH) | |
1176 | continue; | |
1177 | if (write(netpipepair[1], netdev->name, IFNAMSIZ) != IFNAMSIZ) { | |
1178 | ERROR("Error writing veth name to container"); | |
1179 | goto out_delete_net; | |
1180 | } | |
1181 | } | |
1182 | close(netpipepair[1]); | |
1183 | } | |
1184 | ||
1185 | /* map the container uids - the container became an invalid | |
1186 | * userid the moment it was cloned with CLONE_NEWUSER - this | |
1187 | * call doesn't change anything immediately, but allows the | |
1188 | * container to setuid(0) (0 being mapped to something else on | |
1189 | * the host) later to become a valid uid again */ | |
1190 | if (lxc_map_ids(&handler->conf->id_map, handler->pid)) { | |
1191 | ERROR("failed to set up id mapping"); | |
1192 | goto out_delete_net; | |
1193 | } | |
1194 | ||
1195 | /* Tell the child to continue its initialization. we'll get | |
1196 | * LXC_SYNC_CGROUP when it is ready for us to setup cgroups | |
1197 | */ | |
1198 | if (lxc_sync_barrier_child(handler, LXC_SYNC_POST_CONFIGURE)) | |
1199 | goto out_delete_net; | |
1200 | ||
1201 | if (!cgroup_setup_limits(handler, true)) { | |
1202 | ERROR("failed to setup the devices cgroup for '%s'", name); | |
1203 | goto out_delete_net; | |
1204 | } | |
1205 | ||
1206 | cgroup_disconnect(); | |
1207 | cgroups_connected = false; | |
1208 | ||
1209 | /* read tty fds allocated by child */ | |
1210 | if (recv_ttys_from_child(handler) < 0) { | |
1211 | ERROR("failed to receive tty info from child"); | |
1212 | goto out_delete_net; | |
1213 | } | |
1214 | ||
1215 | /* Tell the child to complete its initialization and wait for | |
1216 | * it to exec or return an error. (the child will never | |
1217 | * return LXC_SYNC_POST_CGROUP+1. It will either close the | |
1218 | * sync pipe, causing lxc_sync_barrier_child to return | |
1219 | * success, or return a different value, causing us to error | |
1220 | * out). | |
1221 | */ | |
1222 | if (lxc_sync_barrier_child(handler, LXC_SYNC_POST_CGROUP)) | |
1223 | return -1; | |
1224 | ||
1225 | if (detect_shared_rootfs()) | |
1226 | umount2(handler->conf->rootfs.mount, MNT_DETACH); | |
1227 | ||
1228 | if (handler->ops->post_start(handler, handler->data)) | |
1229 | goto out_abort; | |
1230 | ||
1231 | if (lxc_set_state(name, handler, RUNNING)) { | |
1232 | ERROR("failed to set state to %s", | |
1233 | lxc_state2str(RUNNING)); | |
1234 | goto out_abort; | |
1235 | } | |
1236 | ||
1237 | lxc_sync_fini(handler); | |
1238 | ||
1239 | return 0; | |
1240 | ||
1241 | out_delete_net: | |
1242 | if (cgroups_connected) | |
1243 | cgroup_disconnect(); | |
1244 | if (handler->clone_flags & CLONE_NEWNET) | |
1245 | lxc_delete_network(handler); | |
1246 | out_abort: | |
1247 | lxc_abort(name, handler); | |
1248 | lxc_sync_fini(handler); | |
1249 | if (handler->pinfd >= 0) { | |
1250 | close(handler->pinfd); | |
1251 | handler->pinfd = -1; | |
1252 | } | |
1253 | ||
1254 | return -1; | |
1255 | } | |
1256 | ||
1257 | int get_netns_fd(int pid) | |
1258 | { | |
1259 | char path[MAXPATHLEN]; | |
1260 | int ret, fd; | |
1261 | ||
1262 | ret = snprintf(path, MAXPATHLEN, "/proc/%d/ns/net", pid); | |
1263 | if (ret < 0 || ret >= MAXPATHLEN) { | |
1264 | WARN("Failed to pin netns file for pid %d", pid); | |
1265 | return -1; | |
1266 | } | |
1267 | ||
1268 | fd = open(path, O_RDONLY); | |
1269 | if (fd < 0) { | |
1270 | WARN("Failed to pin netns file %s for pid %d: %s", | |
1271 | path, pid, strerror(errno)); | |
1272 | return -1; | |
1273 | } | |
1274 | return fd; | |
1275 | } | |
1276 | ||
1277 | int __lxc_start(const char *name, struct lxc_conf *conf, | |
1278 | struct lxc_operations* ops, void *data, const char *lxcpath, | |
1279 | bool backgrounded) | |
1280 | { | |
1281 | struct lxc_handler *handler; | |
1282 | int err = -1; | |
1283 | int status; | |
1284 | int netnsfd = -1; | |
1285 | ||
1286 | handler = lxc_init(name, conf, lxcpath); | |
1287 | if (!handler) { | |
1288 | ERROR("failed to initialize the container"); | |
1289 | return -1; | |
1290 | } | |
1291 | handler->ops = ops; | |
1292 | handler->data = data; | |
1293 | handler->backgrounded = backgrounded; | |
1294 | ||
1295 | if (must_drop_cap_sys_boot(handler->conf)) { | |
1296 | #if HAVE_SYS_CAPABILITY_H | |
1297 | DEBUG("Dropping cap_sys_boot"); | |
1298 | #else | |
1299 | DEBUG("Can't drop cap_sys_boot as capabilities aren't supported"); | |
1300 | #endif | |
1301 | } else { | |
1302 | DEBUG("Not dropping cap_sys_boot or watching utmp"); | |
1303 | handler->conf->need_utmp_watch = 0; | |
1304 | } | |
1305 | ||
1306 | if (!attach_block_device(handler->conf)) { | |
1307 | ERROR("Failure attaching block device"); | |
1308 | goto out_fini_nonet; | |
1309 | } | |
1310 | ||
1311 | if (geteuid() == 0 && !lxc_list_empty(&conf->id_map)) { | |
1312 | /* if the backing store is a device, mount it here and now */ | |
1313 | if (rootfs_is_blockdev(conf)) { | |
1314 | if (unshare(CLONE_NEWNS) < 0) { | |
1315 | ERROR("Error unsharing mounts"); | |
1316 | goto out_fini_nonet; | |
1317 | } | |
1318 | remount_all_slave(); | |
1319 | if (do_rootfs_setup(conf, name, lxcpath) < 0) { | |
1320 | ERROR("Error setting up rootfs mount as root before spawn"); | |
1321 | goto out_fini_nonet; | |
1322 | } | |
1323 | INFO("Set up container rootfs as host root"); | |
1324 | } | |
1325 | } | |
1326 | ||
1327 | err = lxc_spawn(handler); | |
1328 | if (err) { | |
1329 | ERROR("failed to spawn '%s'", name); | |
1330 | goto out_detach_blockdev; | |
1331 | } | |
1332 | ||
1333 | handler->conf->reboot = 0; | |
1334 | ||
1335 | netnsfd = get_netns_fd(handler->pid); | |
1336 | ||
1337 | err = lxc_poll(name, handler); | |
1338 | if (err) { | |
1339 | ERROR("mainloop exited with an error"); | |
1340 | if (netnsfd >= 0) | |
1341 | close(netnsfd); | |
1342 | goto out_abort; | |
1343 | } | |
1344 | ||
1345 | while (waitpid(handler->pid, &status, 0) < 0 && errno == EINTR) | |
1346 | continue; | |
1347 | ||
1348 | /* | |
1349 | * If the child process exited but was not signaled, | |
1350 | * it didn't call reboot. This should mean it was an | |
1351 | * lxc-execute which simply exited. In any case, treat | |
1352 | * it as a 'halt' | |
1353 | */ | |
1354 | if (WIFSIGNALED(status)) { | |
1355 | switch(WTERMSIG(status)) { | |
1356 | case SIGINT: /* halt */ | |
1357 | DEBUG("Container halting"); | |
1358 | break; | |
1359 | case SIGHUP: /* reboot */ | |
1360 | DEBUG("Container rebooting"); | |
1361 | handler->conf->reboot = 1; | |
1362 | break; | |
1363 | case SIGSYS: /* seccomp */ | |
1364 | DEBUG("Container violated its seccomp policy"); | |
1365 | break; | |
1366 | default: | |
1367 | DEBUG("unknown exit status for init: %d", WTERMSIG(status)); | |
1368 | break; | |
1369 | } | |
1370 | } | |
1371 | ||
1372 | DEBUG("Pushing physical nics back to host namespace"); | |
1373 | lxc_rename_phys_nics_on_shutdown(netnsfd, handler->conf); | |
1374 | ||
1375 | DEBUG("Tearing down virtual network devices used by container"); | |
1376 | lxc_delete_network(handler); | |
1377 | ||
1378 | if (netnsfd >= 0) | |
1379 | close(netnsfd); | |
1380 | ||
1381 | if (handler->pinfd >= 0) { | |
1382 | close(handler->pinfd); | |
1383 | handler->pinfd = -1; | |
1384 | } | |
1385 | ||
1386 | lxc_monitor_send_exit_code(name, status, handler->lxcpath); | |
1387 | err = lxc_error_set_and_log(handler->pid, status); | |
1388 | out_fini: | |
1389 | lxc_delete_network(handler); | |
1390 | ||
1391 | out_detach_blockdev: | |
1392 | detach_block_device(handler->conf); | |
1393 | ||
1394 | out_fini_nonet: | |
1395 | lxc_fini(name, handler); | |
1396 | return err; | |
1397 | ||
1398 | out_abort: | |
1399 | lxc_abort(name, handler); | |
1400 | goto out_fini; | |
1401 | } | |
1402 | ||
1403 | struct start_args { | |
1404 | char *const *argv; | |
1405 | }; | |
1406 | ||
1407 | static int start(struct lxc_handler *handler, void* data) | |
1408 | { | |
1409 | struct start_args *arg = data; | |
1410 | ||
1411 | NOTICE("exec'ing '%s'", arg->argv[0]); | |
1412 | ||
1413 | execvp(arg->argv[0], arg->argv); | |
1414 | SYSERROR("failed to exec %s", arg->argv[0]); | |
1415 | return 0; | |
1416 | } | |
1417 | ||
1418 | static int post_start(struct lxc_handler *handler, void* data) | |
1419 | { | |
1420 | struct start_args *arg = data; | |
1421 | ||
1422 | NOTICE("'%s' started with pid '%d'", arg->argv[0], handler->pid); | |
1423 | return 0; | |
1424 | } | |
1425 | ||
1426 | static struct lxc_operations start_ops = { | |
1427 | .start = start, | |
1428 | .post_start = post_start | |
1429 | }; | |
1430 | ||
1431 | int lxc_start(const char *name, char *const argv[], struct lxc_conf *conf, | |
1432 | const char *lxcpath, bool backgrounded) | |
1433 | { | |
1434 | struct start_args start_arg = { | |
1435 | .argv = argv, | |
1436 | }; | |
1437 | ||
1438 | conf->need_utmp_watch = 1; | |
1439 | return __lxc_start(name, conf, &start_ops, &start_arg, lxcpath, backgrounded); | |
1440 | } | |
1441 | ||
1442 | static void lxc_destroy_container_on_signal(struct lxc_handler *handler, | |
1443 | const char *name) | |
1444 | { | |
1445 | char destroy[MAXPATHLEN]; | |
1446 | bool bret = true; | |
1447 | int ret = 0; | |
1448 | struct lxc_container *c; | |
1449 | if (handler->conf->rootfs.path && handler->conf->rootfs.mount) { | |
1450 | bret = do_destroy_container(handler->conf); | |
1451 | if (!bret) { | |
1452 | ERROR("Error destroying rootfs for %s", name); | |
1453 | return; | |
1454 | } | |
1455 | } | |
1456 | INFO("Destroyed rootfs for %s", name); | |
1457 | ||
1458 | ret = snprintf(destroy, MAXPATHLEN, "%s/%s", handler->lxcpath, name); | |
1459 | if (ret < 0 || ret >= MAXPATHLEN) { | |
1460 | ERROR("Error printing path for %s", name); | |
1461 | ERROR("Error destroying directory for %s", name); | |
1462 | return; | |
1463 | } | |
1464 | ||
1465 | c = lxc_container_new(name, handler->lxcpath); | |
1466 | if (c) { | |
1467 | if (container_disk_lock(c)) { | |
1468 | INFO("Could not update lxc_snapshots file"); | |
1469 | lxc_container_put(c); | |
1470 | } else { | |
1471 | mod_all_rdeps(c, false); | |
1472 | container_disk_unlock(c); | |
1473 | lxc_container_put(c); | |
1474 | } | |
1475 | } | |
1476 | ||
1477 | if (am_unpriv()) | |
1478 | ret = userns_exec_1(handler->conf, lxc_rmdir_onedev_wrapper, destroy); | |
1479 | else | |
1480 | ret = lxc_rmdir_onedev(destroy, NULL); | |
1481 | ||
1482 | if (ret < 0) { | |
1483 | ERROR("Error destroying directory for %s", name); | |
1484 | return; | |
1485 | } | |
1486 | INFO("Destroyed directory for %s", name); | |
1487 | } | |
1488 | ||
1489 | static int lxc_rmdir_onedev_wrapper(void *data) | |
1490 | { | |
1491 | char *arg = (char *) data; | |
1492 | return lxc_rmdir_onedev(arg, NULL); | |
1493 | } | |
1494 | ||
1495 | static bool do_destroy_container(struct lxc_conf *conf) { | |
1496 | if (am_unpriv()) { | |
1497 | if (userns_exec_1(conf, bdev_destroy_wrapper, conf) < 0) | |
1498 | return false; | |
1499 | return true; | |
1500 | } | |
1501 | return bdev_destroy(conf); | |
1502 | } |