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Commit | Line | Data |
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e0732705 CS |
1 | /* |
2 | * lxc: linux Container library | |
3 | * | |
4 | * (C) Copyright IBM Corp. 2007, 2008 | |
5 | * | |
6 | * Authors: | |
9afe19d6 | 7 | * Daniel Lezcano <daniel.lezcano at free.fr> |
e0732705 CS |
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 | |
250b1eec | 21 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
e0732705 CS |
22 | */ |
23 | ||
24 | #define _GNU_SOURCE | |
e0732705 CS |
25 | #include <errno.h> |
26 | #include <fcntl.h> | |
c476bdce | 27 | #include <grp.h> |
6f4f1937 CB |
28 | #include <pwd.h> |
29 | #include <signal.h> | |
30 | #include <stdio.h> | |
31 | #include <stdlib.h> | |
32 | #include <string.h> | |
33 | #include <unistd.h> | |
34 | #include <linux/unistd.h> | |
35 | #include <sys/mount.h> | |
e0732705 CS |
36 | #include <sys/param.h> |
37 | #include <sys/prctl.h> | |
5ec27989 | 38 | #include <sys/socket.h> |
1ba0013f | 39 | #include <sys/syscall.h> |
905022f7 | 40 | #include <sys/wait.h> |
6f4f1937 CB |
41 | |
42 | #include <lxc/lxccontainer.h> | |
e0732705 | 43 | |
955e2a02 | 44 | #ifndef HAVE_DECL_PR_CAPBSET_DROP |
e0732705 CS |
45 | #define PR_CAPBSET_DROP 24 |
46 | #endif | |
47 | ||
955e2a02 CB |
48 | #ifndef HAVE_DECL_PR_SET_NO_NEW_PRIVS |
49 | #define PR_SET_NO_NEW_PRIVS 38 | |
50 | #endif | |
51 | ||
52 | #ifndef HAVE_DECL_PR_GET_NO_NEW_PRIVS | |
53 | #define PR_GET_NO_NEW_PRIVS 39 | |
54 | #endif | |
55 | ||
81f466d0 | 56 | #include "af_unix.h" |
e0732705 CS |
57 | #include "attach.h" |
58 | #include "caps.h" | |
9c4693b8 | 59 | #include "cgroup.h" |
6f4f1937 | 60 | #include "commands.h" |
2c4ea790 | 61 | #include "conf.h" |
6f4f1937 | 62 | #include "config.h" |
9b8e3c96 | 63 | #include "confile.h" |
b75c344c | 64 | #include "console.h" |
6f4f1937 CB |
65 | #include "log.h" |
66 | #include "lsm/lsm.h" | |
67 | #include "lxclock.h" | |
68 | #include "lxcseccomp.h" | |
ba2be1a8 | 69 | #include "mainloop.h" |
6f4f1937 CB |
70 | #include "namespace.h" |
71 | #include "utils.h" | |
9c4693b8 CS |
72 | |
73 | #if HAVE_SYS_PERSONALITY_H | |
74 | #include <sys/personality.h> | |
75 | #endif | |
e0732705 | 76 | |
a3da2f3b | 77 | #ifndef SOCK_CLOEXEC |
6f4f1937 | 78 | #define SOCK_CLOEXEC 02000000 |
a3da2f3b SG |
79 | #endif |
80 | ||
d6a3c917 SG |
81 | #ifndef MS_REC |
82 | #define MS_REC 16384 | |
83 | #endif | |
84 | ||
85 | #ifndef MS_SLAVE | |
6f4f1937 | 86 | #define MS_SLAVE (1 << 19) |
d6a3c917 SG |
87 | #endif |
88 | ||
e0732705 CS |
89 | lxc_log_define(lxc_attach, lxc); |
90 | ||
8ce83369 | 91 | /* /proc/pid-to-str/status\0 = (5 + 21 + 7 + 1) */ |
eab15c1e | 92 | #define __PROC_STATUS_LEN (5 + (LXC_NUMSTRLEN64) + 7 + 1) |
74a3920a | 93 | static struct lxc_proc_context_info *lxc_proc_get_context_info(pid_t pid) |
e0732705 | 94 | { |
6f4f1937 CB |
95 | int ret; |
96 | bool found; | |
e0732705 | 97 | FILE *proc_file; |
8ce83369 | 98 | char proc_fn[__PROC_STATUS_LEN]; |
e0732705 | 99 | size_t line_bufsz = 0; |
6f4f1937 | 100 | char *line = NULL; |
8ce83369 | 101 | struct lxc_proc_context_info *info = NULL; |
e0732705 | 102 | |
8ce83369 CB |
103 | /* Read capabilities. */ |
104 | ret = snprintf(proc_fn, __PROC_STATUS_LEN, "/proc/%d/status", pid); | |
105 | if (ret < 0 || ret >= __PROC_STATUS_LEN) | |
106 | goto on_error; | |
e0732705 CS |
107 | |
108 | proc_file = fopen(proc_fn, "r"); | |
109 | if (!proc_file) { | |
8ce83369 CB |
110 | SYSERROR("Could not open %s.", proc_fn); |
111 | goto on_error; | |
e0732705 CS |
112 | } |
113 | ||
8ce83369 CB |
114 | info = calloc(1, sizeof(*info)); |
115 | if (!info) { | |
116 | SYSERROR("Could not allocate memory."); | |
17ac5301 | 117 | fclose(proc_file); |
8ce83369 CB |
118 | return NULL; |
119 | } | |
120 | ||
121 | found = false; | |
e0732705 CS |
122 | while (getline(&line, &line_bufsz, proc_file) != -1) { |
123 | ret = sscanf(line, "CapBnd: %llx", &info->capability_mask); | |
8ce83369 CB |
124 | if (ret != EOF && ret == 1) { |
125 | found = true; | |
e0732705 CS |
126 | break; |
127 | } | |
128 | } | |
129 | ||
f10fad2f | 130 | free(line); |
e0732705 CS |
131 | fclose(proc_file); |
132 | ||
133 | if (!found) { | |
6f4f1937 CB |
134 | SYSERROR("Could not read capability bounding set from %s.", |
135 | proc_fn); | |
e0732705 | 136 | errno = ENOENT; |
8ce83369 | 137 | goto on_error; |
e0732705 CS |
138 | } |
139 | ||
fe4de9a6 | 140 | info->lsm_label = lsm_process_label_get(pid); |
877f3a04 CB |
141 | info->ns_inherited = 0; |
142 | memset(info->ns_fd, -1, sizeof(int) * LXC_NS_MAX); | |
e0732705 | 143 | |
e0732705 CS |
144 | return info; |
145 | ||
8ce83369 | 146 | on_error: |
460a1cf0 | 147 | free(info); |
e0732705 CS |
148 | return NULL; |
149 | } | |
150 | ||
877f3a04 CB |
151 | static inline void lxc_proc_close_ns_fd(struct lxc_proc_context_info *ctx) |
152 | { | |
153 | int i; | |
154 | ||
155 | for (i = 0; i < LXC_NS_MAX; i++) { | |
156 | if (ctx->ns_fd[i] < 0) | |
157 | continue; | |
158 | close(ctx->ns_fd[i]); | |
159 | ctx->ns_fd[i] = -EBADF; | |
160 | } | |
161 | } | |
162 | ||
fe4de9a6 DE |
163 | static void lxc_proc_put_context_info(struct lxc_proc_context_info *ctx) |
164 | { | |
f10fad2f | 165 | free(ctx->lsm_label); |
08ea9270 CB |
166 | ctx->lsm_label = NULL; |
167 | ||
168 | if (ctx->container) { | |
2c4ea790 | 169 | lxc_container_put(ctx->container); |
08ea9270 CB |
170 | ctx->container = NULL; |
171 | } | |
172 | ||
877f3a04 | 173 | lxc_proc_close_ns_fd(ctx); |
fe4de9a6 | 174 | free(ctx); |
08ea9270 | 175 | ctx = NULL; |
fe4de9a6 DE |
176 | } |
177 | ||
299d1198 CB |
178 | /** |
179 | * in_same_namespace - Check whether two processes are in the same namespace. | |
180 | * @pid1 - PID of the first process. | |
181 | * @pid2 - PID of the second process. | |
182 | * @ns - Name of the namespace to check. Must correspond to one of the names | |
183 | * for the namespaces as shown in /proc/<pid/ns/ | |
184 | * | |
185 | * If the two processes are not in the same namespace returns an fd to the | |
186 | * namespace of the second process identified by @pid2. If the two processes are | |
187 | * in the same namespace returns -EINVAL, -1 if an error occurred. | |
188 | */ | |
189 | static int in_same_namespace(pid_t pid1, pid_t pid2, const char *ns) | |
190 | { | |
191 | int ns_fd1 = -1, ns_fd2 = -1, ret = -1; | |
192 | struct stat ns_st1, ns_st2; | |
193 | ||
194 | ns_fd1 = lxc_preserve_ns(pid1, ns); | |
134284c3 CB |
195 | if (ns_fd1 < 0) { |
196 | /* The kernel does not support this namespace. This is not an | |
197 | * error. | |
198 | */ | |
199 | if (errno == ENOENT) | |
200 | return -EINVAL; | |
201 | ||
299d1198 | 202 | goto out; |
134284c3 | 203 | } |
299d1198 CB |
204 | |
205 | ns_fd2 = lxc_preserve_ns(pid2, ns); | |
206 | if (ns_fd2 < 0) | |
207 | goto out; | |
208 | ||
209 | ret = fstat(ns_fd1, &ns_st1); | |
210 | if (ret < 0) | |
211 | goto out; | |
212 | ||
213 | ret = fstat(ns_fd2, &ns_st2); | |
214 | if (ret < 0) | |
215 | goto out; | |
216 | ||
217 | /* processes are in the same namespace */ | |
218 | ret = -EINVAL; | |
219 | if ((ns_st1.st_dev == ns_st2.st_dev ) && (ns_st1.st_ino == ns_st2.st_ino)) | |
220 | goto out; | |
221 | ||
222 | /* processes are in different namespaces */ | |
223 | ret = ns_fd2; | |
224 | ns_fd2 = -1; | |
225 | ||
226 | out: | |
227 | ||
228 | if (ns_fd1 >= 0) | |
229 | close(ns_fd1); | |
230 | if (ns_fd2 >= 0) | |
231 | close(ns_fd2); | |
232 | ||
233 | return ret; | |
234 | } | |
235 | ||
877f3a04 | 236 | static int lxc_attach_to_ns(pid_t pid, struct lxc_proc_context_info *ctx) |
99d50954 | 237 | { |
877f3a04 | 238 | int i, ret; |
99d50954 | 239 | |
26818618 | 240 | for (i = 0; i < LXC_NS_MAX; i++) { |
877f3a04 | 241 | if (ctx->ns_fd[i] < 0) |
26818618 CB |
242 | continue; |
243 | ||
877f3a04 CB |
244 | ret = setns(ctx->ns_fd[i], ns_info[i].clone_flag); |
245 | if (ret < 0) { | |
299d1198 CB |
246 | SYSERROR("Failed to attach to %s namespace of %d", |
247 | ns_info[i].proc_name, pid); | |
99d50954 CS |
248 | return -1; |
249 | } | |
250 | ||
299d1198 | 251 | DEBUG("Attached to %s namespace of %d", ns_info[i].proc_name, pid); |
99d50954 CS |
252 | } |
253 | ||
254 | return 0; | |
255 | } | |
256 | ||
74a3920a | 257 | static int lxc_attach_remount_sys_proc(void) |
7a0b0b56 CS |
258 | { |
259 | int ret; | |
260 | ||
261 | ret = unshare(CLONE_NEWNS); | |
262 | if (ret < 0) { | |
8ce83369 | 263 | SYSERROR("Failed to unshare mount namespace."); |
7a0b0b56 CS |
264 | return -1; |
265 | } | |
266 | ||
2c6f3fc9 | 267 | if (detect_shared_rootfs()) { |
6f4f1937 | 268 | if (mount(NULL, "/", NULL, MS_SLAVE | MS_REC, NULL)) { |
8ce83369 | 269 | SYSERROR("Failed to make / rslave."); |
2c6f3fc9 SH |
270 | ERROR("Continuing..."); |
271 | } | |
272 | } | |
273 | ||
8ce83369 | 274 | /* Assume /proc is always mounted, so remount it. */ |
7a0b0b56 CS |
275 | ret = umount2("/proc", MNT_DETACH); |
276 | if (ret < 0) { | |
8ce83369 | 277 | SYSERROR("Failed to unmount /proc."); |
7a0b0b56 CS |
278 | return -1; |
279 | } | |
280 | ||
281 | ret = mount("none", "/proc", "proc", 0, NULL); | |
282 | if (ret < 0) { | |
8ce83369 | 283 | SYSERROR("Failed to remount /proc."); |
7a0b0b56 CS |
284 | return -1; |
285 | } | |
286 | ||
8ce83369 CB |
287 | /* Try to umount /sys. If it's not a mount point, we'll get EINVAL, then |
288 | * we ignore it because it may not have been mounted in the first place. | |
7a0b0b56 CS |
289 | */ |
290 | ret = umount2("/sys", MNT_DETACH); | |
291 | if (ret < 0 && errno != EINVAL) { | |
8ce83369 | 292 | SYSERROR("Failed to unmount /sys."); |
7a0b0b56 CS |
293 | return -1; |
294 | } else if (ret == 0) { | |
8ce83369 | 295 | /* Remount it. */ |
7a0b0b56 CS |
296 | ret = mount("none", "/sys", "sysfs", 0, NULL); |
297 | if (ret < 0) { | |
8ce83369 | 298 | SYSERROR("Failed to remount /sys."); |
7a0b0b56 CS |
299 | return -1; |
300 | } | |
301 | } | |
302 | ||
303 | return 0; | |
304 | } | |
305 | ||
74a3920a | 306 | static int lxc_attach_drop_privs(struct lxc_proc_context_info *ctx) |
e0732705 | 307 | { |
6f4f1937 | 308 | int cap, last_cap; |
e0732705 | 309 | |
6f4f1937 | 310 | last_cap = lxc_caps_last_cap(); |
e0732705 CS |
311 | for (cap = 0; cap <= last_cap; cap++) { |
312 | if (ctx->capability_mask & (1LL << cap)) | |
313 | continue; | |
314 | ||
315 | if (prctl(PR_CAPBSET_DROP, cap, 0, 0, 0)) { | |
94ac256f | 316 | SYSERROR("Failed to drop capability %d", cap); |
e0732705 CS |
317 | return -1; |
318 | } | |
94ac256f | 319 | TRACE("Dropped capability %d", cap); |
e0732705 CS |
320 | } |
321 | ||
322 | return 0; | |
323 | } | |
905022f7 | 324 | |
7385273f | 325 | static int lxc_attach_set_environment(struct lxc_proc_context_info *init_ctx, |
326 | enum lxc_attach_env_policy_t policy, | |
6f4f1937 | 327 | char **extra_env, char **extra_keep) |
b3a39ba6 | 328 | { |
7385273f | 329 | struct lxc_list *iterator; |
330 | ||
799f96fd | 331 | if (policy == LXC_ATTACH_CLEAR_ENV) { |
3d5e9f48 | 332 | int path_kept = 0; |
6f4f1937 | 333 | char **extra_keep_store = NULL; |
3d5e9f48 CS |
334 | |
335 | if (extra_keep) { | |
336 | size_t count, i; | |
337 | ||
338 | for (count = 0; extra_keep[count]; count++); | |
339 | ||
340 | extra_keep_store = calloc(count, sizeof(char *)); | |
341 | if (!extra_keep_store) { | |
8ce83369 CB |
342 | SYSERROR("Failed to allocate memory for storing current " |
343 | "environment variable values that will be kept."); | |
3d5e9f48 CS |
344 | return -1; |
345 | } | |
346 | for (i = 0; i < count; i++) { | |
347 | char *v = getenv(extra_keep[i]); | |
348 | if (v) { | |
349 | extra_keep_store[i] = strdup(v); | |
350 | if (!extra_keep_store[i]) { | |
8ce83369 CB |
351 | SYSERROR("Failed to allocate memory for storing current " |
352 | "environment variable values that will be kept."); | |
3d5e9f48 CS |
353 | while (i > 0) |
354 | free(extra_keep_store[--i]); | |
355 | free(extra_keep_store); | |
356 | return -1; | |
357 | } | |
358 | if (strcmp(extra_keep[i], "PATH") == 0) | |
359 | path_kept = 1; | |
360 | } | |
8ce83369 CB |
361 | /* Calloc sets entire array to zero, so we don't |
362 | * need an else. | |
363 | */ | |
3d5e9f48 CS |
364 | } |
365 | } | |
366 | ||
799f96fd | 367 | if (clearenv()) { |
a9cab7e3 | 368 | char **p; |
6f4f1937 | 369 | |
8ce83369 | 370 | SYSERROR("Failed to clear environment."); |
a9cab7e3 CS |
371 | if (extra_keep_store) { |
372 | for (p = extra_keep_store; *p; p++) | |
373 | free(*p); | |
374 | free(extra_keep_store); | |
375 | } | |
3d5e9f48 CS |
376 | return -1; |
377 | } | |
378 | ||
379 | if (extra_keep_store) { | |
380 | size_t i; | |
6f4f1937 | 381 | |
3d5e9f48 | 382 | for (i = 0; extra_keep[i]; i++) { |
acd4922e SG |
383 | if (extra_keep_store[i]) { |
384 | if (setenv(extra_keep[i], extra_keep_store[i], 1) < 0) | |
8ce83369 | 385 | SYSERROR("Unable to set environment variable."); |
acd4922e | 386 | } |
3d5e9f48 CS |
387 | free(extra_keep_store[i]); |
388 | } | |
389 | free(extra_keep_store); | |
390 | } | |
391 | ||
8ce83369 CB |
392 | /* Always set a default path; shells and execlp tend to be fine |
393 | * without it, but there is a disturbing number of C programs | |
394 | * out there that just assume that getenv("PATH") is never NULL | |
395 | * and then die a painful segfault death. | |
396 | */ | |
cfa70b88 | 397 | if (!path_kept) |
511a6936 | 398 | setenv("PATH", "/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin", 1); |
b3a39ba6 DW |
399 | } |
400 | ||
401 | if (putenv("container=lxc")) { | |
8ce83369 | 402 | SYSERROR("Failed to set environment variable."); |
b3a39ba6 DW |
403 | return -1; |
404 | } | |
405 | ||
7385273f | 406 | /* Set container environment variables.*/ |
407 | if (init_ctx && init_ctx->container && init_ctx->container->lxc_conf) { | |
408 | lxc_list_for_each(iterator, &init_ctx->container->lxc_conf->environment) { | |
409 | char *env_tmp = strdup((char *)iterator->elem); | |
410 | if (!env_tmp) { | |
411 | SYSERROR("Failed to allocate memory for container environment " | |
412 | "variables."); | |
413 | return -1; | |
414 | } | |
415 | ||
416 | if (putenv(env_tmp)) { | |
417 | SYSERROR("Failed to set environment variable: %s.", (char *)iterator->elem); | |
418 | return -1; | |
419 | } | |
420 | } | |
421 | } | |
422 | ||
8ce83369 | 423 | /* Set extra environment variables. */ |
3d5e9f48 CS |
424 | if (extra_env) { |
425 | for (; *extra_env; extra_env++) { | |
8ce83369 CB |
426 | /* Duplicate the string, just to be on the safe side, |
427 | * because putenv does not do it for us. | |
428 | */ | |
3d5e9f48 | 429 | char *p = strdup(*extra_env); |
8ce83369 CB |
430 | /* We just assume the user knows what they are doing, so |
431 | * we don't do any checks. | |
432 | */ | |
3d5e9f48 | 433 | if (!p) { |
8ce83369 CB |
434 | SYSERROR("Failed to allocate memory for additional environment " |
435 | "variables."); | |
3d5e9f48 CS |
436 | return -1; |
437 | } | |
438 | putenv(p); | |
439 | } | |
440 | } | |
441 | ||
b3a39ba6 DW |
442 | return 0; |
443 | } | |
444 | ||
74a3920a | 445 | static char *lxc_attach_getpwshell(uid_t uid) |
905022f7 | 446 | { |
6f4f1937 | 447 | int fd, ret; |
905022f7 CS |
448 | pid_t pid; |
449 | int pipes[2]; | |
905022f7 CS |
450 | char *result = NULL; |
451 | ||
8ce83369 CB |
452 | /* We need to fork off a process that runs the getent program, and we |
453 | * need to capture its output, so we use a pipe for that purpose. | |
905022f7 CS |
454 | */ |
455 | ret = pipe(pipes); | |
456 | if (ret < 0) | |
457 | return NULL; | |
458 | ||
459 | pid = fork(); | |
460 | if (pid < 0) { | |
461 | close(pipes[0]); | |
462 | close(pipes[1]); | |
463 | return NULL; | |
464 | } | |
465 | ||
466 | if (pid) { | |
6f4f1937 | 467 | int status; |
905022f7 | 468 | FILE *pipe_f; |
905022f7 | 469 | int found = 0; |
6f4f1937 CB |
470 | size_t line_bufsz = 0; |
471 | char *line = NULL; | |
905022f7 CS |
472 | |
473 | close(pipes[1]); | |
474 | ||
475 | pipe_f = fdopen(pipes[0], "r"); | |
476 | while (getline(&line, &line_bufsz, pipe_f) != -1) { | |
905022f7 | 477 | int i; |
6f4f1937 CB |
478 | long value; |
479 | char *token; | |
480 | char *endptr = NULL, *saveptr = NULL; | |
905022f7 | 481 | |
8ce83369 CB |
482 | /* If we already found something, just continue to read |
483 | * until the pipe doesn't deliver any more data, but | |
484 | * don't modify the existing data structure. | |
905022f7 CS |
485 | */ |
486 | if (found) | |
487 | continue; | |
488 | ||
8ce83369 | 489 | /* Trim line on the right hand side. */ |
bbb8a488 | 490 | for (i = strlen(line); i > 0 && (line[i - 1] == '\n' || line[i - 1] == '\r'); --i) |
905022f7 CS |
491 | line[i - 1] = '\0'; |
492 | ||
8ce83369 | 493 | /* Split into tokens: first: user name. */ |
905022f7 CS |
494 | token = strtok_r(line, ":", &saveptr); |
495 | if (!token) | |
496 | continue; | |
497 | /* next: dummy password field */ | |
498 | token = strtok_r(NULL, ":", &saveptr); | |
499 | if (!token) | |
500 | continue; | |
501 | /* next: user id */ | |
502 | token = strtok_r(NULL, ":", &saveptr); | |
503 | value = token ? strtol(token, &endptr, 10) : 0; | |
504 | if (!token || !endptr || *endptr || value == LONG_MIN || value == LONG_MAX) | |
505 | continue; | |
506 | /* dummy sanity check: user id matches */ | |
507 | if ((uid_t) value != uid) | |
508 | continue; | |
509 | /* skip fields: gid, gecos, dir, go to next field 'shell' */ | |
510 | for (i = 0; i < 4; i++) { | |
511 | token = strtok_r(NULL, ":", &saveptr); | |
512 | if (!token) | |
513 | break; | |
514 | } | |
515 | if (!token) | |
516 | continue; | |
f10fad2f | 517 | free(result); |
905022f7 CS |
518 | result = strdup(token); |
519 | ||
8ce83369 | 520 | /* Sanity check that there are no fields after that. */ |
905022f7 CS |
521 | token = strtok_r(NULL, ":", &saveptr); |
522 | if (token) | |
523 | continue; | |
524 | ||
525 | found = 1; | |
526 | } | |
527 | ||
528 | free(line); | |
529 | fclose(pipe_f); | |
530 | again: | |
531 | if (waitpid(pid, &status, 0) < 0) { | |
532 | if (errno == EINTR) | |
533 | goto again; | |
f4e1fa60 | 534 | free(result); |
905022f7 CS |
535 | return NULL; |
536 | } | |
537 | ||
8ce83369 CB |
538 | /* Some sanity checks. If anything even hinted at going wrong, |
539 | * we can't be sure we have a valid result, so we assume we | |
540 | * don't. | |
905022f7 CS |
541 | */ |
542 | ||
f4e1fa60 CB |
543 | if (!WIFEXITED(status)) { |
544 | free(result); | |
905022f7 | 545 | return NULL; |
f4e1fa60 | 546 | } |
905022f7 | 547 | |
f4e1fa60 CB |
548 | if (WEXITSTATUS(status) != 0) { |
549 | free(result); | |
905022f7 | 550 | return NULL; |
f4e1fa60 | 551 | } |
905022f7 | 552 | |
f4e1fa60 CB |
553 | if (!found) { |
554 | free(result); | |
905022f7 | 555 | return NULL; |
f4e1fa60 | 556 | } |
905022f7 CS |
557 | |
558 | return result; | |
559 | } else { | |
905022f7 CS |
560 | char uid_buf[32]; |
561 | char *arguments[] = { | |
562 | "getent", | |
563 | "passwd", | |
564 | uid_buf, | |
565 | NULL | |
566 | }; | |
567 | ||
568 | close(pipes[0]); | |
569 | ||
8ce83369 | 570 | /* We want to capture stdout. */ |
905022f7 CS |
571 | dup2(pipes[1], 1); |
572 | close(pipes[1]); | |
573 | ||
8ce83369 CB |
574 | /* Get rid of stdin/stderr, so we try to associate it with |
575 | * /dev/null. | |
905022f7 CS |
576 | */ |
577 | fd = open("/dev/null", O_RDWR); | |
578 | if (fd < 0) { | |
579 | close(0); | |
580 | close(2); | |
581 | } else { | |
582 | dup2(fd, 0); | |
583 | dup2(fd, 2); | |
584 | close(fd); | |
585 | } | |
586 | ||
8ce83369 | 587 | /* Finish argument list. */ |
905022f7 CS |
588 | ret = snprintf(uid_buf, sizeof(uid_buf), "%ld", (long) uid); |
589 | if (ret <= 0) | |
590 | exit(-1); | |
591 | ||
8ce83369 | 592 | /* Try to run getent program. */ |
905022f7 CS |
593 | (void) execvp("getent", arguments); |
594 | exit(-1); | |
595 | } | |
596 | } | |
cb3e61fa | 597 | |
6f4f1937 | 598 | static void lxc_attach_get_init_uidgid(uid_t *init_uid, gid_t *init_gid) |
cb3e61fa CS |
599 | { |
600 | FILE *proc_file; | |
8ce83369 CB |
601 | char proc_fn[__PROC_STATUS_LEN]; |
602 | int ret; | |
cb3e61fa CS |
603 | char *line = NULL; |
604 | size_t line_bufsz = 0; | |
cb3e61fa CS |
605 | long value = -1; |
606 | uid_t uid = (uid_t)-1; | |
607 | gid_t gid = (gid_t)-1; | |
608 | ||
8ce83369 CB |
609 | /* Read capabilities. */ |
610 | snprintf(proc_fn, __PROC_STATUS_LEN, "/proc/%d/status", 1); | |
cb3e61fa CS |
611 | |
612 | proc_file = fopen(proc_fn, "r"); | |
613 | if (!proc_file) | |
614 | return; | |
615 | ||
616 | while (getline(&line, &line_bufsz, proc_file) != -1) { | |
8ce83369 CB |
617 | /* Format is: real, effective, saved set user, fs we only care |
618 | * about real uid. | |
cb3e61fa CS |
619 | */ |
620 | ret = sscanf(line, "Uid: %ld", &value); | |
8ce83369 | 621 | if (ret != EOF && ret == 1) { |
6f4f1937 | 622 | uid = (uid_t)value; |
cb3e61fa CS |
623 | } else { |
624 | ret = sscanf(line, "Gid: %ld", &value); | |
8ce83369 | 625 | if (ret != EOF && ret == 1) |
6f4f1937 | 626 | gid = (gid_t)value; |
cb3e61fa CS |
627 | } |
628 | if (uid != (uid_t)-1 && gid != (gid_t)-1) | |
629 | break; | |
630 | } | |
631 | ||
632 | fclose(proc_file); | |
633 | free(line); | |
634 | ||
8ce83369 | 635 | /* Only override arguments if we found something. */ |
cb3e61fa CS |
636 | if (uid != (uid_t)-1) |
637 | *init_uid = uid; | |
638 | if (gid != (gid_t)-1) | |
639 | *init_gid = gid; | |
640 | ||
641 | /* TODO: we should also parse supplementary groups and use | |
8ce83369 CB |
642 | * setgroups() to set them. |
643 | */ | |
cb3e61fa | 644 | } |
9c4693b8 | 645 | |
8ce83369 | 646 | /* Help the optimizer along if it doesn't know that exit always exits. */ |
6f4f1937 CB |
647 | #define rexit(c) \ |
648 | do { \ | |
649 | int __c = (c); \ | |
650 | _exit(__c); \ | |
651 | return __c; \ | |
652 | } while (0) | |
9c4693b8 | 653 | |
8ce83369 | 654 | /* Define default options if no options are supplied by the user. */ |
9c4693b8 CS |
655 | static lxc_attach_options_t attach_static_default_options = LXC_ATTACH_OPTIONS_DEFAULT; |
656 | ||
bd4307f0 | 657 | static bool fetch_seccomp(struct lxc_container *c, |
ff07d7bb | 658 | lxc_attach_options_t *options) |
2c4ea790 | 659 | { |
bd7b4e28 | 660 | char *path; |
2eef2bda | 661 | |
6f4f1937 CB |
662 | if (!(options->namespaces & CLONE_NEWNS) || |
663 | !(options->attach_flags & LXC_ATTACH_LSM)) { | |
bd4307f0 CB |
664 | free(c->lxc_conf->seccomp); |
665 | c->lxc_conf->seccomp = NULL; | |
2c4ea790 | 666 | return true; |
bd4307f0 | 667 | } |
bd7b4e28 | 668 | |
2e812c16 | 669 | /* Remove current setting. */ |
0b427da0 CB |
670 | if (!c->set_config_item(c, "lxc.seccomp", "") && |
671 | !c->set_config_item(c, "lxc.seccomp.profile", "")) { | |
2c4ea790 | 672 | return false; |
bd7b4e28 SG |
673 | } |
674 | ||
8ce83369 | 675 | /* Fetch the current profile path over the cmd interface. */ |
0b427da0 | 676 | path = c->get_running_config_item(c, "lxc.seccomp.profile"); |
bd7b4e28 | 677 | if (!path) { |
0b427da0 CB |
678 | INFO("Failed to get running config item for lxc.seccomp.profile"); |
679 | path = c->get_running_config_item(c, "lxc.seccomp"); | |
680 | } | |
681 | if (!path) { | |
682 | INFO("Failed to get running config item for lxc.seccomp"); | |
bd7b4e28 SG |
683 | return true; |
684 | } | |
685 | ||
8ce83369 | 686 | /* Copy the value into the new lxc_conf. */ |
0b427da0 | 687 | if (!c->set_config_item(c, "lxc.seccomp.profile", path)) { |
bd7b4e28 SG |
688 | free(path); |
689 | return false; | |
690 | } | |
691 | free(path); | |
692 | ||
8ce83369 | 693 | /* Attempt to parse the resulting config. */ |
2c4ea790 | 694 | if (lxc_read_seccomp_config(c->lxc_conf) < 0) { |
8ce83369 | 695 | ERROR("Error reading seccomp policy."); |
2c4ea790 SH |
696 | return false; |
697 | } | |
698 | ||
2e812c16 CB |
699 | INFO("Retrieved seccomp policy."); |
700 | return true; | |
701 | } | |
702 | ||
6f4f1937 | 703 | static bool no_new_privs(struct lxc_container *c, lxc_attach_options_t *options) |
2e812c16 | 704 | { |
2e812c16 CB |
705 | char *val; |
706 | ||
2e812c16 | 707 | /* Remove current setting. */ |
6f4f1937 | 708 | if (!c->set_config_item(c, "lxc.no_new_privs", "")) |
2e812c16 | 709 | return false; |
2e812c16 CB |
710 | |
711 | /* Retrieve currently active setting. */ | |
712 | val = c->get_running_config_item(c, "lxc.no_new_privs"); | |
713 | if (!val) { | |
714 | INFO("Failed to get running config item for lxc.no_new_privs."); | |
715 | return false; | |
716 | } | |
717 | ||
718 | /* Set currently active setting. */ | |
719 | if (!c->set_config_item(c, "lxc.no_new_privs", val)) { | |
720 | free(val); | |
721 | return false; | |
722 | } | |
723 | free(val); | |
724 | ||
2c4ea790 SH |
725 | return true; |
726 | } | |
727 | ||
9b8e3c96 SH |
728 | static signed long get_personality(const char *name, const char *lxcpath) |
729 | { | |
6f4f1937 | 730 | char *p; |
9b8e3c96 SH |
731 | signed long ret; |
732 | ||
6f4f1937 | 733 | p = lxc_cmd_get_config_item(name, "lxc.arch", lxcpath); |
9b8e3c96 SH |
734 | if (!p) |
735 | return -1; | |
6f4f1937 | 736 | |
9b8e3c96 SH |
737 | ret = lxc_config_parse_arch(p); |
738 | free(p); | |
6f4f1937 | 739 | |
9b8e3c96 SH |
740 | return ret; |
741 | } | |
742 | ||
a998454a CB |
743 | struct attach_clone_payload { |
744 | int ipc_socket; | |
ba2be1a8 | 745 | int pty_fd; |
a998454a CB |
746 | lxc_attach_options_t *options; |
747 | struct lxc_proc_context_info *init_ctx; | |
748 | lxc_attach_exec_t exec_function; | |
749 | void *exec_payload; | |
750 | }; | |
751 | ||
ba2be1a8 CB |
752 | static void lxc_put_attach_clone_payload(struct attach_clone_payload *p) |
753 | { | |
754 | if (p->ipc_socket >= 0) { | |
755 | shutdown(p->ipc_socket, SHUT_RDWR); | |
756 | close(p->ipc_socket); | |
757 | p->ipc_socket = -EBADF; | |
758 | } | |
759 | ||
760 | if (p->pty_fd >= 0) { | |
761 | close(p->pty_fd); | |
762 | p->pty_fd = -EBADF; | |
763 | } | |
764 | ||
b21da190 | 765 | if (p->init_ctx) { |
ba2be1a8 | 766 | lxc_proc_put_context_info(p->init_ctx); |
b21da190 CB |
767 | p->init_ctx = NULL; |
768 | } | |
ba2be1a8 CB |
769 | } |
770 | ||
a998454a CB |
771 | static int attach_child_main(struct attach_clone_payload *payload) |
772 | { | |
57de839f | 773 | int fd, lsm_fd, ret; |
a998454a CB |
774 | uid_t new_uid; |
775 | gid_t new_gid; | |
a998454a CB |
776 | lxc_attach_options_t* options = payload->options; |
777 | struct lxc_proc_context_info* init_ctx = payload->init_ctx; | |
57de839f CB |
778 | bool needs_lsm = (options->namespaces & CLONE_NEWNS) && |
779 | (options->attach_flags & LXC_ATTACH_LSM) && | |
780 | init_ctx->lsm_label; | |
a998454a CB |
781 | |
782 | /* A description of the purpose of this functionality is provided in the | |
783 | * lxc-attach(1) manual page. We have to remount here and not in the | |
784 | * parent process, otherwise /proc may not properly reflect the new pid | |
785 | * namespace. | |
786 | */ | |
787 | if (!(options->namespaces & CLONE_NEWNS) && | |
788 | (options->attach_flags & LXC_ATTACH_REMOUNT_PROC_SYS)) { | |
789 | ret = lxc_attach_remount_sys_proc(); | |
b75c344c CB |
790 | if (ret < 0) |
791 | goto on_error; | |
792 | TRACE("Remounted \"/proc\" and \"/sys\""); | |
a998454a CB |
793 | } |
794 | ||
b75c344c | 795 | /* Now perform additional attachments. */ |
a998454a | 796 | #if HAVE_SYS_PERSONALITY_H |
a998454a | 797 | if (options->attach_flags & LXC_ATTACH_SET_PERSONALITY) { |
b75c344c CB |
798 | long new_personality; |
799 | ||
800 | if (options->personality < 0) | |
801 | new_personality = init_ctx->personality; | |
802 | else | |
803 | new_personality = options->personality; | |
a998454a | 804 | ret = personality(new_personality); |
b75c344c CB |
805 | if (ret < 0) |
806 | goto on_error; | |
807 | TRACE("Set new personality"); | |
a998454a CB |
808 | } |
809 | #endif | |
810 | ||
811 | if (options->attach_flags & LXC_ATTACH_DROP_CAPABILITIES) { | |
812 | ret = lxc_attach_drop_privs(init_ctx); | |
b75c344c CB |
813 | if (ret < 0) |
814 | goto on_error; | |
815 | TRACE("Dropped capabilities"); | |
a998454a CB |
816 | } |
817 | ||
818 | /* Always set the environment (specify (LXC_ATTACH_KEEP_ENV, NULL, NULL) | |
819 | * if you want this to be a no-op). | |
820 | */ | |
7385273f | 821 | ret = lxc_attach_set_environment(init_ctx, |
822 | options->env_policy, | |
a998454a CB |
823 | options->extra_env_vars, |
824 | options->extra_keep_env); | |
b75c344c CB |
825 | if (ret < 0) |
826 | goto on_error; | |
827 | TRACE("Set up environment"); | |
a998454a | 828 | |
57de839f CB |
829 | /* This remark only affects fully unprivileged containers: |
830 | * Receive fd for LSM security module before we set{g,u}id(). The reason | |
831 | * is that on set{g,u}id() the kernel will a) make us undumpable and b) | |
832 | * we will change our effective uid. This means our effective uid will | |
833 | * be different from the effective uid of the process that created us | |
834 | * which means that this processs no longer has capabilities in our | |
835 | * namespace including CAP_SYS_PTRACE. This means we will not be able to | |
836 | * read and /proc/<pid> files for the process anymore when /proc is | |
837 | * mounted with hidepid={1,2}. So let's get the lsm label fd before the | |
838 | * set{g,u}id(). | |
839 | */ | |
840 | if (needs_lsm) { | |
b75c344c CB |
841 | ret = lxc_abstract_unix_recv_fds(payload->ipc_socket, &lsm_fd, 1, NULL, 0); |
842 | if (ret <= 0) | |
843 | goto on_error; | |
57de839f CB |
844 | TRACE("Received LSM label file descriptor %d from parent", lsm_fd); |
845 | } | |
846 | ||
08ea9270 CB |
847 | if (options->stdin_fd > 0 && isatty(options->stdin_fd)) { |
848 | ret = lxc_make_controlling_pty(options->stdin_fd); | |
849 | if (ret < 0) | |
850 | goto on_error; | |
851 | } | |
852 | ||
a998454a CB |
853 | /* Set {u,g}id. */ |
854 | new_uid = 0; | |
855 | new_gid = 0; | |
856 | /* Ignore errors, we will fall back to root in that case (/proc was not | |
857 | * mounted etc.). | |
858 | */ | |
859 | if (options->namespaces & CLONE_NEWUSER) | |
860 | lxc_attach_get_init_uidgid(&new_uid, &new_gid); | |
861 | ||
862 | if (options->uid != (uid_t)-1) | |
863 | new_uid = options->uid; | |
864 | if (options->gid != (gid_t)-1) | |
865 | new_gid = options->gid; | |
866 | ||
a998454a | 867 | /* Try to set the {u,g}id combination. */ |
b75c344c CB |
868 | if (new_uid != 0 || new_gid != 0 || options->namespaces & CLONE_NEWUSER) { |
869 | ret = lxc_switch_uid_gid(new_uid, new_gid); | |
870 | if (ret < 0) | |
871 | goto on_error; | |
872 | ||
873 | ret = lxc_setgroups(0, NULL); | |
874 | if (ret < 0) | |
875 | goto on_error; | |
a998454a CB |
876 | } |
877 | ||
878 | if ((init_ctx->container && init_ctx->container->lxc_conf && | |
879 | init_ctx->container->lxc_conf->no_new_privs) || | |
880 | (options->attach_flags & LXC_ATTACH_NO_NEW_PRIVS)) { | |
b75c344c CB |
881 | ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); |
882 | if (ret < 0) | |
883 | goto on_error; | |
884 | TRACE("Set PR_SET_NO_NEW_PRIVS"); | |
a998454a CB |
885 | } |
886 | ||
57de839f | 887 | if (needs_lsm) { |
d3ba7c98 | 888 | bool on_exec; |
a998454a CB |
889 | |
890 | /* Change into our new LSM profile. */ | |
d3ba7c98 CB |
891 | on_exec = options->attach_flags & LXC_ATTACH_LSM_EXEC ? true : false; |
892 | ret = lsm_process_label_set_at(lsm_fd, init_ctx->lsm_label, on_exec); | |
57de839f | 893 | close(lsm_fd); |
b75c344c CB |
894 | if (ret < 0) |
895 | goto on_error; | |
d3ba7c98 | 896 | TRACE("Set %s LSM label to \"%s\"", lsm_name(), init_ctx->lsm_label); |
a998454a CB |
897 | } |
898 | ||
899 | if (init_ctx->container && init_ctx->container->lxc_conf && | |
b75c344c CB |
900 | init_ctx->container->lxc_conf->seccomp) { |
901 | ret = lxc_seccomp_load(init_ctx->container->lxc_conf); | |
902 | if (ret < 0) | |
903 | goto on_error; | |
904 | TRACE("Loaded seccomp profile"); | |
a998454a | 905 | } |
b75c344c CB |
906 | shutdown(payload->ipc_socket, SHUT_RDWR); |
907 | close(payload->ipc_socket); | |
ba2be1a8 CB |
908 | payload->ipc_socket = -EBADF; |
909 | lxc_proc_put_context_info(init_ctx); | |
a998454a CB |
910 | |
911 | /* The following is done after the communication socket is shut down. | |
912 | * That way, all errors that might (though unlikely) occur up until this | |
913 | * point will have their messages printed to the original stderr (if | |
914 | * logging is so configured) and not the fd the user supplied, if any. | |
915 | */ | |
916 | ||
917 | /* Fd handling for stdin, stdout and stderr; ignore errors here, user | |
918 | * may want to make sure the fds are closed, for example. | |
919 | */ | |
08ea9270 CB |
920 | if (options->stdin_fd >= 0 && options->stdin_fd != STDIN_FILENO) |
921 | dup2(options->stdin_fd, STDIN_FILENO); | |
922 | ||
923 | if (options->stdout_fd >= 0 && options->stdout_fd != STDOUT_FILENO) | |
924 | dup2(options->stdout_fd, STDOUT_FILENO); | |
925 | ||
926 | if (options->stderr_fd >= 0 && options->stderr_fd != STDERR_FILENO) | |
927 | dup2(options->stderr_fd, STDERR_FILENO); | |
a998454a CB |
928 | |
929 | /* close the old fds */ | |
08ea9270 | 930 | if (options->stdin_fd > STDERR_FILENO) |
a998454a | 931 | close(options->stdin_fd); |
08ea9270 CB |
932 | |
933 | if (options->stdout_fd > STDERR_FILENO) | |
a998454a | 934 | close(options->stdout_fd); |
08ea9270 CB |
935 | |
936 | if (options->stderr_fd > STDERR_FILENO) | |
a998454a CB |
937 | close(options->stderr_fd); |
938 | ||
939 | /* Try to remove FD_CLOEXEC flag from stdin/stdout/stderr, but also | |
940 | * here, ignore errors. | |
941 | */ | |
b75c344c CB |
942 | for (fd = STDIN_FILENO; fd <= STDERR_FILENO; fd++) { |
943 | int flags; | |
944 | ||
a998454a CB |
945 | flags = fcntl(fd, F_GETFL); |
946 | if (flags < 0) | |
947 | continue; | |
b75c344c CB |
948 | |
949 | if ((flags & FD_CLOEXEC) == 0) | |
950 | continue; | |
951 | ||
952 | ret = fcntl(fd, F_SETFL, flags & ~FD_CLOEXEC); | |
953 | if (ret < 0) { | |
954 | SYSERROR("Failed to clear FD_CLOEXEC from file descriptor %d", fd); | |
955 | goto on_error; | |
956 | } | |
a998454a CB |
957 | } |
958 | ||
ba2be1a8 CB |
959 | if (options->attach_flags & LXC_ATTACH_ALLOCATE_PTY) { |
960 | ret = lxc_login_pty(payload->pty_fd); | |
961 | if (ret < 0) { | |
962 | SYSERROR("Failed to prepare pty file descriptor %d", payload->pty_fd); | |
963 | goto on_error; | |
964 | } | |
965 | TRACE("Prepared pty file descriptor %d", payload->pty_fd); | |
966 | } | |
967 | ||
a998454a CB |
968 | /* We're done, so we can now do whatever the user intended us to do. */ |
969 | rexit(payload->exec_function(payload->exec_payload)); | |
b75c344c CB |
970 | |
971 | on_error: | |
ba2be1a8 | 972 | lxc_put_attach_clone_payload(payload); |
b75c344c | 973 | rexit(EXIT_FAILURE); |
a998454a CB |
974 | } |
975 | ||
ba2be1a8 CB |
976 | static int lxc_attach_pty(struct lxc_conf *conf, struct lxc_console *pty) |
977 | { | |
978 | int ret; | |
979 | ||
980 | lxc_pty_init(pty); | |
981 | ||
982 | ret = lxc_pty_create(pty); | |
983 | if (ret < 0) { | |
984 | SYSERROR("Failed to create pty"); | |
985 | return -1; | |
986 | } | |
987 | ||
988 | /* Shift ttys to container. */ | |
989 | ret = lxc_pty_map_ids(conf, pty); | |
990 | if (ret < 0) { | |
991 | ERROR("Failed to shift pty"); | |
992 | goto on_error; | |
993 | } | |
994 | ||
995 | return 0; | |
996 | ||
997 | on_error: | |
998 | lxc_console_delete(pty); | |
999 | lxc_pty_conf_free(pty); | |
1000 | return -1; | |
1001 | } | |
1002 | ||
1003 | static int lxc_attach_pty_mainloop_init(struct lxc_console *pty, | |
1004 | struct lxc_epoll_descr *descr) | |
1005 | { | |
1006 | int ret; | |
1007 | ||
1008 | ret = lxc_mainloop_open(descr); | |
1009 | if (ret < 0) { | |
1010 | ERROR("Failed to create mainloop"); | |
1011 | return -1; | |
1012 | } | |
1013 | ||
1014 | ret = lxc_console_mainloop_add(descr, pty); | |
1015 | if (ret < 0) { | |
1016 | ERROR("Failed to add handlers to mainloop"); | |
1017 | lxc_mainloop_close(descr); | |
1018 | return -1; | |
1019 | } | |
1020 | ||
1021 | return 0; | |
1022 | } | |
1023 | ||
1024 | static inline void lxc_attach_pty_close_master(struct lxc_console *pty) | |
1025 | { | |
1026 | if (pty->master < 0) | |
1027 | return; | |
1028 | ||
1029 | close(pty->master); | |
1030 | pty->master = -EBADF; | |
1031 | } | |
1032 | ||
1033 | static inline void lxc_attach_pty_close_slave(struct lxc_console *pty) | |
1034 | { | |
1035 | if (pty->slave < 0) | |
1036 | return; | |
1037 | ||
1038 | close(pty->slave); | |
1039 | pty->slave = -EBADF; | |
1040 | } | |
1041 | ||
1042 | static inline void lxc_attach_pty_close_peer(struct lxc_console *pty) | |
1043 | { | |
1044 | if (pty->peer < 0) | |
1045 | return; | |
1046 | ||
1047 | close(pty->peer); | |
1048 | pty->peer = -EBADF; | |
1049 | } | |
1050 | ||
1051 | static inline void lxc_attach_pty_close_log(struct lxc_console *pty) | |
1052 | { | |
1053 | if (pty->log_fd < 0) | |
1054 | return; | |
1055 | ||
1056 | close(pty->log_fd); | |
1057 | pty->log_fd = -EBADF; | |
1058 | } | |
1059 | ||
6f4f1937 CB |
1060 | int lxc_attach(const char *name, const char *lxcpath, |
1061 | lxc_attach_exec_t exec_function, void *exec_payload, | |
1062 | lxc_attach_options_t *options, pid_t *attached_process) | |
9c4693b8 | 1063 | { |
877f3a04 | 1064 | int i, ret, status; |
9c4693b8 | 1065 | int ipc_sockets[2]; |
6f4f1937 | 1066 | char *cwd, *new_cwd; |
9b8e3c96 | 1067 | signed long personality; |
ba2be1a8 | 1068 | pid_t attached_pid, init_pid, pid; |
6f4f1937 | 1069 | struct lxc_proc_context_info *init_ctx; |
ba2be1a8 | 1070 | struct lxc_console pty; |
1cce35e6 | 1071 | struct lxc_conf *conf; |
a998454a | 1072 | struct attach_clone_payload payload = {0}; |
9c4693b8 | 1073 | |
877f3a04 CB |
1074 | ret = access("/proc/self/ns", X_OK); |
1075 | if (ret) { | |
1076 | ERROR("Does this kernel version support namespaces?"); | |
1077 | return -1; | |
1078 | } | |
1079 | ||
9c4693b8 CS |
1080 | if (!options) |
1081 | options = &attach_static_default_options; | |
1082 | ||
1083 | init_pid = lxc_cmd_get_init_pid(name, lxcpath); | |
1084 | if (init_pid < 0) { | |
8ce83369 | 1085 | ERROR("Failed to get init pid."); |
9c4693b8 CS |
1086 | return -1; |
1087 | } | |
1088 | ||
1089 | init_ctx = lxc_proc_get_context_info(init_pid); | |
1090 | if (!init_ctx) { | |
6f4f1937 | 1091 | ERROR("Failed to get context of init process: %ld", (long)init_pid); |
9c4693b8 CS |
1092 | return -1; |
1093 | } | |
1094 | ||
9b8e3c96 SH |
1095 | personality = get_personality(name, lxcpath); |
1096 | if (init_ctx->personality < 0) { | |
6f4f1937 | 1097 | ERROR("Failed to get personality of the container"); |
9b8e3c96 SH |
1098 | lxc_proc_put_context_info(init_ctx); |
1099 | return -1; | |
1100 | } | |
1101 | init_ctx->personality = personality; | |
1102 | ||
ff07d7bb | 1103 | init_ctx->container = lxc_container_new(name, lxcpath); |
62de1db6 CB |
1104 | if (!init_ctx->container) { |
1105 | lxc_proc_put_context_info(init_ctx); | |
ff07d7bb | 1106 | return -1; |
62de1db6 | 1107 | } |
ff07d7bb | 1108 | |
ba773996 CB |
1109 | if (!init_ctx->container->lxc_conf) { |
1110 | init_ctx->container->lxc_conf = lxc_conf_init(); | |
62de1db6 CB |
1111 | if (!init_ctx->container->lxc_conf) { |
1112 | lxc_proc_put_context_info(init_ctx); | |
ba773996 | 1113 | return -ENOMEM; |
62de1db6 | 1114 | } |
ba773996 | 1115 | } |
1cce35e6 | 1116 | conf = init_ctx->container->lxc_conf; |
ba773996 | 1117 | |
bd4307f0 | 1118 | if (!fetch_seccomp(init_ctx->container, options)) |
8ce83369 | 1119 | WARN("Failed to get seccomp policy."); |
2c4ea790 | 1120 | |
bd4307f0 | 1121 | if (!no_new_privs(init_ctx->container, options)) |
2e812c16 CB |
1122 | WARN("Could not determine whether PR_SET_NO_NEW_PRIVS is set."); |
1123 | ||
9c4693b8 CS |
1124 | cwd = getcwd(NULL, 0); |
1125 | ||
8ce83369 CB |
1126 | /* Determine which namespaces the container was created with |
1127 | * by asking lxc-start, if necessary. | |
9c4693b8 CS |
1128 | */ |
1129 | if (options->namespaces == -1) { | |
1130 | options->namespaces = lxc_cmd_get_clone_flags(name, lxcpath); | |
1131 | /* call failed */ | |
1132 | if (options->namespaces == -1) { | |
8ce83369 | 1133 | ERROR("Failed to automatically determine the " |
877f3a04 | 1134 | "namespaces which the container uses"); |
9c4693b8 | 1135 | free(cwd); |
fe4de9a6 | 1136 | lxc_proc_put_context_info(init_ctx); |
9c4693b8 CS |
1137 | return -1; |
1138 | } | |
877f3a04 CB |
1139 | |
1140 | for (i = 0; i < LXC_NS_MAX; i++) { | |
1141 | if (ns_info[i].clone_flag & CLONE_NEWCGROUP) | |
1142 | if (!(options->attach_flags & LXC_ATTACH_MOVE_TO_CGROUP) || | |
1143 | !cgns_supported()) | |
1144 | continue; | |
1145 | ||
1146 | if (ns_info[i].clone_flag & options->namespaces) | |
1147 | continue; | |
1148 | ||
1149 | init_ctx->ns_inherited |= ns_info[i].clone_flag; | |
1150 | } | |
1151 | } | |
1152 | ||
0059379f | 1153 | pid = lxc_raw_getpid(); |
877f3a04 CB |
1154 | for (i = 0; i < LXC_NS_MAX; i++) { |
1155 | int j, saved_errno; | |
1156 | ||
1157 | if (options->namespaces & ns_info[i].clone_flag) | |
1158 | init_ctx->ns_fd[i] = lxc_preserve_ns(init_pid, ns_info[i].proc_name); | |
1159 | else if (init_ctx->ns_inherited & ns_info[i].clone_flag) | |
1160 | init_ctx->ns_fd[i] = in_same_namespace(pid, init_pid, ns_info[i].proc_name); | |
1161 | else | |
1162 | continue; | |
1163 | if (init_ctx->ns_fd[i] >= 0) | |
1164 | continue; | |
1165 | ||
1166 | if (init_ctx->ns_fd[i] == -EINVAL) { | |
1167 | DEBUG("Inheriting %s namespace from %d", | |
1168 | ns_info[i].proc_name, pid); | |
1169 | init_ctx->ns_inherited &= ~ns_info[i].clone_flag; | |
1170 | continue; | |
1171 | } | |
1172 | ||
1173 | /* We failed to preserve the namespace. */ | |
1174 | saved_errno = errno; | |
1175 | /* Close all already opened file descriptors before we return an | |
1176 | * error, so we don't leak them. | |
1177 | */ | |
1178 | for (j = 0; j < i; j++) | |
1179 | close(init_ctx->ns_fd[j]); | |
1180 | ||
1181 | errno = saved_errno; | |
1182 | SYSERROR("Failed to attach to %s namespace of %d", | |
1183 | ns_info[i].proc_name, pid); | |
1184 | free(cwd); | |
1185 | lxc_proc_put_context_info(init_ctx); | |
1186 | return -1; | |
9c4693b8 CS |
1187 | } |
1188 | ||
ba2be1a8 | 1189 | if (options->attach_flags & LXC_ATTACH_ALLOCATE_PTY) { |
1cce35e6 | 1190 | ret = lxc_attach_pty(conf, &pty); |
ba2be1a8 CB |
1191 | if (ret < 0) { |
1192 | ERROR("Failed to allocate pty"); | |
1193 | free(cwd); | |
1194 | lxc_proc_put_context_info(init_ctx); | |
1195 | return -1; | |
1196 | } | |
1197 | ||
1198 | pty.log_fd = options->log_fd; | |
c948657b CB |
1199 | } else { |
1200 | lxc_pty_init(&pty); | |
ba2be1a8 CB |
1201 | } |
1202 | ||
8ce83369 CB |
1203 | /* Create a socket pair for IPC communication; set SOCK_CLOEXEC in order |
1204 | * to make sure we don't irritate other threads that want to fork+exec | |
1205 | * away | |
9c4693b8 CS |
1206 | * |
1207 | * IMPORTANT: if the initial process is multithreaded and another call | |
1208 | * just fork()s away without exec'ing directly after, the socket fd will | |
1209 | * exist in the forked process from the other thread and any close() in | |
8ce83369 CB |
1210 | * our own child process will not really cause the socket to close |
1211 | * properly, potentiall causing the parent to hang. | |
9c4693b8 CS |
1212 | * |
1213 | * For this reason, while IPC is still active, we have to use shutdown() | |
8ce83369 CB |
1214 | * if the child exits prematurely in order to signal that the socket is |
1215 | * closed and cannot assume that the child exiting will automatically do | |
1216 | * that. | |
9c4693b8 CS |
1217 | * |
1218 | * IPC mechanism: (X is receiver) | |
1219 | * initial process intermediate attached | |
1220 | * X <--- send pid of | |
1221 | * attached proc, | |
1222 | * then exit | |
1223 | * send 0 ------------------------------------> X | |
1224 | * [do initialization] | |
1225 | * X <------------------------------------ send 1 | |
1226 | * [add to cgroup, ...] | |
1227 | * send 2 ------------------------------------> X | |
81f466d0 CB |
1228 | * [set LXC_ATTACH_NO_NEW_PRIVS] |
1229 | * X <------------------------------------ send 3 | |
1230 | * [open LSM label fd] | |
1231 | * send 4 ------------------------------------> X | |
1232 | * [set LSM label] | |
9c4693b8 CS |
1233 | * close socket close socket |
1234 | * run program | |
1235 | */ | |
1236 | ret = socketpair(PF_LOCAL, SOCK_STREAM | SOCK_CLOEXEC, 0, ipc_sockets); | |
1237 | if (ret < 0) { | |
8ce83369 | 1238 | SYSERROR("Could not set up required IPC mechanism for attaching."); |
9c4693b8 | 1239 | free(cwd); |
fe4de9a6 | 1240 | lxc_proc_put_context_info(init_ctx); |
9c4693b8 CS |
1241 | return -1; |
1242 | } | |
1243 | ||
8ce83369 CB |
1244 | /* Create intermediate subprocess, three reasons: |
1245 | * 1. Runs all pthread_atfork handlers and the child will no | |
1246 | * longer be threaded (we can't properly setns() in a threaded | |
1247 | * process). | |
1248 | * 2. We can't setns() in the child itself, since we want to make | |
1249 | * sure we are properly attached to the pidns. | |
1250 | * 3. Also, the initial thread has to put the attached process | |
1251 | * into the cgroup, which we can only do if we didn't already | |
1252 | * setns() (otherwise, user namespaces will hate us). | |
9c4693b8 CS |
1253 | */ |
1254 | pid = fork(); | |
9c4693b8 | 1255 | if (pid < 0) { |
8ce83369 | 1256 | SYSERROR("Failed to create first subprocess."); |
9c4693b8 | 1257 | free(cwd); |
fe4de9a6 | 1258 | lxc_proc_put_context_info(init_ctx); |
9c4693b8 CS |
1259 | return -1; |
1260 | } | |
1261 | ||
1262 | if (pid) { | |
ba2be1a8 | 1263 | int ret_parent = -1; |
9c4693b8 | 1264 | pid_t to_cleanup_pid = pid; |
ba2be1a8 | 1265 | struct lxc_epoll_descr descr = {0}; |
9c4693b8 | 1266 | |
ba2be1a8 | 1267 | /* close unneeded file descriptors */ |
9c4693b8 CS |
1268 | close(ipc_sockets[1]); |
1269 | free(cwd); | |
ba2be1a8 CB |
1270 | lxc_proc_close_ns_fd(init_ctx); |
1271 | if (options->attach_flags & LXC_ATTACH_ALLOCATE_PTY) | |
1272 | lxc_attach_pty_close_slave(&pty); | |
9c4693b8 | 1273 | |
8ce83369 | 1274 | /* Attach to cgroup, if requested. */ |
f4364484 | 1275 | if (options->attach_flags & LXC_ATTACH_MOVE_TO_CGROUP) { |
4fb3cba5 | 1276 | if (!cgroup_attach(name, lxcpath, pid)) |
8ce83369 | 1277 | goto on_error; |
94ac256f CB |
1278 | TRACE("Moved intermediate process %d into container's " |
1279 | "cgroups", pid); | |
f4364484 SG |
1280 | } |
1281 | ||
bb2ada6f | 1282 | /* Setup /proc limits */ |
1cce35e6 CB |
1283 | if (!lxc_list_empty(&conf->procs)) { |
1284 | ret = setup_proc_filesystem(&conf->procs, pid); | |
bb2ada6f CB |
1285 | if (ret < 0) |
1286 | goto on_error; | |
1287 | } | |
1288 | ||
c6d09e15 | 1289 | /* Setup resource limits */ |
1cce35e6 CB |
1290 | if (!lxc_list_empty(&conf->limits)) { |
1291 | ret = setup_resource_limits(&conf->limits, pid); | |
ba2be1a8 CB |
1292 | if (ret < 0) |
1293 | goto on_error; | |
1294 | } | |
1295 | ||
1296 | if (options->attach_flags & LXC_ATTACH_ALLOCATE_PTY) { | |
1297 | ret = lxc_attach_pty_mainloop_init(&pty, &descr); | |
1298 | if (ret < 0) | |
6f4f1937 | 1299 | goto on_error; |
ba2be1a8 CB |
1300 | TRACE("Initalized pty mainloop"); |
1301 | } | |
c6d09e15 | 1302 | |
8ce83369 | 1303 | /* Let the child process know to go ahead. */ |
f4364484 SG |
1304 | status = 0; |
1305 | ret = lxc_write_nointr(ipc_sockets[0], &status, sizeof(status)); | |
94ac256f | 1306 | if (ret != sizeof(status)) |
ba2be1a8 | 1307 | goto close_mainloop; |
94ac256f | 1308 | TRACE("Told intermediate process to start initializing"); |
f4364484 | 1309 | |
8ce83369 | 1310 | /* Get pid of attached process from intermediate process. */ |
94ac256f CB |
1311 | ret = lxc_read_nointr(ipc_sockets[0], &attached_pid, sizeof(attached_pid)); |
1312 | if (ret != sizeof(attached_pid)) | |
ba2be1a8 | 1313 | goto close_mainloop; |
94ac256f | 1314 | TRACE("Received pid %d of attached process in parent pid namespace", attached_pid); |
9c4693b8 | 1315 | |
8ce83369 | 1316 | /* Ignore SIGKILL (CTRL-C) and SIGQUIT (CTRL-\) - issue #313. */ |
62183f1a SH |
1317 | if (options->stdin_fd == 0) { |
1318 | signal(SIGINT, SIG_IGN); | |
1319 | signal(SIGQUIT, SIG_IGN); | |
1320 | } | |
2eef2bda | 1321 | |
8ce83369 | 1322 | /* Reap intermediate process. */ |
9c4693b8 CS |
1323 | ret = wait_for_pid(pid); |
1324 | if (ret < 0) | |
ba2be1a8 | 1325 | goto close_mainloop; |
94ac256f | 1326 | TRACE("Intermediate process %d exited", pid); |
9c4693b8 | 1327 | |
8ce83369 | 1328 | /* We will always have to reap the attached process now. */ |
9c4693b8 CS |
1329 | to_cleanup_pid = attached_pid; |
1330 | ||
81f466d0 | 1331 | /* Open LSM fd and send it to child. */ |
6f4f1937 CB |
1332 | if ((options->namespaces & CLONE_NEWNS) && |
1333 | (options->attach_flags & LXC_ATTACH_LSM) && | |
1334 | init_ctx->lsm_label) { | |
94ac256f | 1335 | int ret = -1; |
47ce2cb7 CB |
1336 | int labelfd; |
1337 | bool on_exec; | |
6f4f1937 | 1338 | |
47ce2cb7 CB |
1339 | on_exec = options->attach_flags & LXC_ATTACH_LSM_EXEC ? true : false; |
1340 | labelfd = lsm_process_label_fd_get(attached_pid, on_exec); | |
81f466d0 | 1341 | if (labelfd < 0) |
ba2be1a8 | 1342 | goto close_mainloop; |
94ac256f | 1343 | TRACE("Opened LSM label file descriptor %d", labelfd); |
81f466d0 CB |
1344 | |
1345 | /* Send child fd of the LSM security module to write to. */ | |
ae467c54 | 1346 | ret = lxc_abstract_unix_send_fds(ipc_sockets[0], &labelfd, 1, NULL, 0); |
1d8e5ca2 | 1347 | close(labelfd); |
81f466d0 | 1348 | if (ret <= 0) { |
94ac256f | 1349 | SYSERROR("%d", (int)ret); |
ba2be1a8 | 1350 | goto close_mainloop; |
81f466d0 | 1351 | } |
94ac256f | 1352 | TRACE("Sent LSM label file descriptor %d to child", labelfd); |
81f466d0 CB |
1353 | } |
1354 | ||
8ce83369 CB |
1355 | /* We're done, the child process should now execute whatever it |
1356 | * is that the user requested. The parent can now track it with | |
1357 | * waitpid() or similar. | |
9c4693b8 CS |
1358 | */ |
1359 | ||
1360 | *attached_process = attached_pid; | |
9c4693b8 | 1361 | |
ba2be1a8 | 1362 | /* Now shut down communication with child, we're done. */ |
9c4693b8 CS |
1363 | shutdown(ipc_sockets[0], SHUT_RDWR); |
1364 | close(ipc_sockets[0]); | |
ba2be1a8 CB |
1365 | ipc_sockets[0] = -1; |
1366 | ||
1367 | ret_parent = 0; | |
1368 | to_cleanup_pid = -1; | |
1369 | if (options->attach_flags & LXC_ATTACH_ALLOCATE_PTY) { | |
1370 | ret = lxc_mainloop(&descr, -1); | |
1371 | if (ret < 0) { | |
1372 | ret_parent = -1; | |
1373 | to_cleanup_pid = attached_pid; | |
1374 | } | |
1375 | } | |
1376 | ||
1377 | close_mainloop: | |
1378 | if (options->attach_flags & LXC_ATTACH_ALLOCATE_PTY) | |
1379 | lxc_mainloop_close(&descr); | |
1380 | ||
1381 | on_error: | |
1382 | if (ipc_sockets[0] >= 0) { | |
1383 | shutdown(ipc_sockets[0], SHUT_RDWR); | |
1384 | close(ipc_sockets[0]); | |
1385 | } | |
1386 | ||
1387 | if (to_cleanup_pid > 0) | |
6f4f1937 | 1388 | (void)wait_for_pid(to_cleanup_pid); |
ba2be1a8 CB |
1389 | |
1390 | if (options->attach_flags & LXC_ATTACH_ALLOCATE_PTY) { | |
1391 | lxc_console_delete(&pty); | |
1392 | lxc_pty_conf_free(&pty); | |
1393 | } | |
fe4de9a6 | 1394 | lxc_proc_put_context_info(init_ctx); |
ba2be1a8 | 1395 | return ret_parent; |
9c4693b8 CS |
1396 | } |
1397 | ||
ba2be1a8 | 1398 | /* close unneeded file descriptors */ |
9c4693b8 | 1399 | close(ipc_sockets[0]); |
ba2be1a8 CB |
1400 | ipc_sockets[0] = -EBADF; |
1401 | if (options->attach_flags & LXC_ATTACH_ALLOCATE_PTY) { | |
1402 | lxc_attach_pty_close_master(&pty); | |
1403 | lxc_attach_pty_close_peer(&pty); | |
1404 | lxc_attach_pty_close_log(&pty); | |
1405 | } | |
9c4693b8 | 1406 | |
8ce83369 | 1407 | /* Wait for the parent to have setup cgroups. */ |
94ac256f | 1408 | ret = lxc_read_nointr(ipc_sockets[1], &status, sizeof(status)); |
ba2be1a8 | 1409 | if (ret != sizeof(status)) { |
f4364484 | 1410 | shutdown(ipc_sockets[1], SHUT_RDWR); |
62de1db6 | 1411 | lxc_proc_put_context_info(init_ctx); |
f4364484 SG |
1412 | rexit(-1); |
1413 | } | |
94ac256f | 1414 | TRACE("Intermediate process starting to initialize"); |
f4364484 | 1415 | |
8ce83369 CB |
1416 | /* Attach now, create another subprocess later, since pid namespaces |
1417 | * only really affect the children of the current process. | |
9c4693b8 | 1418 | */ |
877f3a04 | 1419 | ret = lxc_attach_to_ns(init_pid, init_ctx); |
9c4693b8 | 1420 | if (ret < 0) { |
94ac256f | 1421 | ERROR("Failed to enter namespaces"); |
9c4693b8 | 1422 | shutdown(ipc_sockets[1], SHUT_RDWR); |
62de1db6 | 1423 | lxc_proc_put_context_info(init_ctx); |
9c4693b8 CS |
1424 | rexit(-1); |
1425 | } | |
877f3a04 CB |
1426 | /* close namespace file descriptors */ |
1427 | lxc_proc_close_ns_fd(init_ctx); | |
9c4693b8 | 1428 | |
8ce83369 | 1429 | /* Attach succeeded, try to cwd. */ |
9c4693b8 CS |
1430 | if (options->initial_cwd) |
1431 | new_cwd = options->initial_cwd; | |
1432 | else | |
1433 | new_cwd = cwd; | |
d6d979bc CB |
1434 | if (new_cwd) { |
1435 | ret = chdir(new_cwd); | |
1436 | if (ret < 0) | |
1437 | WARN("Could not change directory to \"%s\"", new_cwd); | |
1438 | } | |
9c4693b8 CS |
1439 | free(cwd); |
1440 | ||
a998454a CB |
1441 | /* Create attached process. */ |
1442 | payload.ipc_socket = ipc_sockets[1]; | |
1443 | payload.options = options; | |
1444 | payload.init_ctx = init_ctx; | |
ba2be1a8 | 1445 | payload.pty_fd = pty.slave; |
a998454a CB |
1446 | payload.exec_function = exec_function; |
1447 | payload.exec_payload = exec_payload; | |
9c4693b8 | 1448 | |
a998454a CB |
1449 | pid = lxc_raw_clone(CLONE_PARENT); |
1450 | if (pid < 0) { | |
94ac256f | 1451 | SYSERROR("Failed to clone attached process"); |
9c4693b8 | 1452 | shutdown(ipc_sockets[1], SHUT_RDWR); |
62de1db6 | 1453 | lxc_proc_put_context_info(init_ctx); |
9c4693b8 CS |
1454 | rexit(-1); |
1455 | } | |
a998454a CB |
1456 | |
1457 | if (pid == 0) { | |
1458 | ret = attach_child_main(&payload); | |
1459 | if (ret < 0) | |
1460 | ERROR("Failed to exec"); | |
1461 | _exit(EXIT_FAILURE); | |
1462 | } | |
ba2be1a8 CB |
1463 | if (options->attach_flags & LXC_ATTACH_ALLOCATE_PTY) |
1464 | lxc_attach_pty_close_slave(&pty); | |
9c4693b8 | 1465 | |
8ce83369 | 1466 | /* Tell grandparent the pid of the pid of the newly created child. */ |
9c4693b8 CS |
1467 | ret = lxc_write_nointr(ipc_sockets[1], &pid, sizeof(pid)); |
1468 | if (ret != sizeof(pid)) { | |
8ce83369 CB |
1469 | /* If this really happens here, this is very unfortunate, since |
1470 | * the parent will not know the pid of the attached process and | |
1471 | * will not be able to wait for it (and we won't either due to | |
1472 | * CLONE_PARENT) so the parent won't be able to reap it and the | |
1473 | * attached process will remain a zombie. | |
9c4693b8 | 1474 | */ |
9c4693b8 | 1475 | shutdown(ipc_sockets[1], SHUT_RDWR); |
62de1db6 | 1476 | lxc_proc_put_context_info(init_ctx); |
9c4693b8 CS |
1477 | rexit(-1); |
1478 | } | |
94ac256f | 1479 | TRACE("Sending pid %d of attached process", pid); |
9c4693b8 | 1480 | |
8ce83369 | 1481 | /* The rest is in the hands of the initial and the attached process. */ |
62de1db6 | 1482 | lxc_proc_put_context_info(init_ctx); |
9c4693b8 CS |
1483 | rexit(0); |
1484 | } | |
1485 | ||
9c4693b8 CS |
1486 | int lxc_attach_run_command(void* payload) |
1487 | { | |
1488 | lxc_attach_command_t* cmd = (lxc_attach_command_t*)payload; | |
1489 | ||
1490 | execvp(cmd->program, cmd->argv); | |
8ce83369 | 1491 | SYSERROR("Failed to exec \"%s\".", cmd->program); |
9c4693b8 CS |
1492 | return -1; |
1493 | } | |
1494 | ||
1495 | int lxc_attach_run_shell(void* payload) | |
1496 | { | |
1497 | uid_t uid; | |
1498 | struct passwd *passwd; | |
1499 | char *user_shell; | |
1500 | ||
8ce83369 | 1501 | /* Ignore payload parameter. */ |
9c4693b8 CS |
1502 | (void)payload; |
1503 | ||
1504 | uid = getuid(); | |
1505 | passwd = getpwuid(uid); | |
1506 | ||
8ce83369 CB |
1507 | /* This probably happens because of incompatible nss implementations in |
1508 | * host and container (remember, this code is still using the host's | |
1509 | * glibc but our mount namespace is in the container) we may try to get | |
1510 | * the information by spawning a [getent passwd uid] process and parsing | |
1511 | * the result. | |
9c4693b8 CS |
1512 | */ |
1513 | if (!passwd) | |
1514 | user_shell = lxc_attach_getpwshell(uid); | |
1515 | else | |
1516 | user_shell = passwd->pw_shell; | |
9c4693b8 | 1517 | if (user_shell) |
acf47e1b | 1518 | execlp(user_shell, user_shell, (char *)NULL); |
9c4693b8 | 1519 | |
8ce83369 CB |
1520 | /* Executed if either no passwd entry or execvp fails, we will fall back |
1521 | * on /bin/sh as a default shell. | |
9c4693b8 | 1522 | */ |
acf47e1b | 1523 | execlp("/bin/sh", "/bin/sh", (char *)NULL); |
edeb1836 CB |
1524 | SYSERROR("Failed to execute shell"); |
1525 | if (!passwd) | |
1526 | free(user_shell); | |
9c4693b8 CS |
1527 | return -1; |
1528 | } |