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Commit | Line | Data |
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cc73685d | 1 | /* SPDX-License-Identifier: LGPL-2.1+ */ |
e0732705 | 2 | |
d38dd64a CB |
3 | #ifndef _GNU_SOURCE |
4 | #define _GNU_SOURCE 1 | |
5 | #endif | |
e0732705 CS |
6 | #include <errno.h> |
7 | #include <fcntl.h> | |
c476bdce | 8 | #include <grp.h> |
604ca1c0 | 9 | #include <linux/unistd.h> |
6f4f1937 | 10 | #include <pwd.h> |
0bece477 | 11 | #include <pthread.h> |
6f4f1937 CB |
12 | #include <signal.h> |
13 | #include <stdio.h> | |
14 | #include <stdlib.h> | |
15 | #include <string.h> | |
6f4f1937 | 16 | #include <sys/mount.h> |
e0732705 CS |
17 | #include <sys/param.h> |
18 | #include <sys/prctl.h> | |
5ec27989 | 19 | #include <sys/socket.h> |
1ba0013f | 20 | #include <sys/syscall.h> |
905022f7 | 21 | #include <sys/wait.h> |
604ca1c0 CB |
22 | #include <termios.h> |
23 | #include <unistd.h> | |
6f4f1937 CB |
24 | |
25 | #include <lxc/lxccontainer.h> | |
e0732705 | 26 | |
81f466d0 | 27 | #include "af_unix.h" |
e0732705 CS |
28 | #include "attach.h" |
29 | #include "caps.h" | |
9c4693b8 | 30 | #include "cgroup.h" |
6f4f1937 | 31 | #include "commands.h" |
2c4ea790 | 32 | #include "conf.h" |
6f4f1937 | 33 | #include "config.h" |
9b8e3c96 | 34 | #include "confile.h" |
6f4f1937 CB |
35 | #include "log.h" |
36 | #include "lsm/lsm.h" | |
37 | #include "lxclock.h" | |
38 | #include "lxcseccomp.h" | |
604ca1c0 | 39 | #include "macro.h" |
ba2be1a8 | 40 | #include "mainloop.h" |
cd8f5663 | 41 | #include "memory_utils.h" |
657256e0 | 42 | #include "mount_utils.h" |
6f4f1937 | 43 | #include "namespace.h" |
f40988c7 | 44 | #include "process_utils.h" |
59524108 | 45 | #include "syscall_wrappers.h" |
0ed9b1bc | 46 | #include "terminal.h" |
6f4f1937 | 47 | #include "utils.h" |
9c4693b8 CS |
48 | |
49 | #if HAVE_SYS_PERSONALITY_H | |
50 | #include <sys/personality.h> | |
51 | #endif | |
e0732705 | 52 | |
ac2cecc4 | 53 | lxc_log_define(attach, lxc); |
e0732705 | 54 | |
ef05d368 CB |
55 | /* Define default options if no options are supplied by the user. */ |
56 | static lxc_attach_options_t attach_static_default_options = LXC_ATTACH_OPTIONS_DEFAULT; | |
57 | ||
ab919e5f | 58 | struct attach_context { |
0e304baa CB |
59 | char *lsm_label; |
60 | struct lxc_container *container; | |
61 | signed long personality; | |
62 | unsigned long long capability_mask; | |
63 | int ns_inherited; | |
64 | int ns_fd[LXC_NS_MAX]; | |
65 | struct lsm_ops *lsm_ops; | |
66 | }; | |
67 | ||
dd53c8af | 68 | static struct attach_context *get_attach_context(pid_t pid) |
e0732705 | 69 | { |
cd8f5663 CB |
70 | __do_free char *line = NULL; |
71 | __do_fclose FILE *proc_file = NULL; | |
ab919e5f | 72 | __do_free struct attach_context *info = NULL; |
6f4f1937 CB |
73 | int ret; |
74 | bool found; | |
604ca1c0 | 75 | char proc_fn[LXC_PROC_STATUS_LEN]; |
e0732705 | 76 | size_t line_bufsz = 0; |
e0732705 | 77 | |
8ce83369 | 78 | /* Read capabilities. */ |
604ca1c0 CB |
79 | ret = snprintf(proc_fn, LXC_PROC_STATUS_LEN, "/proc/%d/status", pid); |
80 | if (ret < 0 || ret >= LXC_PROC_STATUS_LEN) | |
cd8f5663 | 81 | return NULL; |
e0732705 | 82 | |
ffeeed8b CB |
83 | proc_file = fopen(proc_fn, "re"); |
84 | if (!proc_file) | |
85 | return log_error_errno(NULL, errno, "Failed to open %s", proc_fn); | |
e0732705 | 86 | |
89b7bfe3 | 87 | info = zalloc(sizeof(*info)); |
cd8f5663 | 88 | if (!info) |
8ce83369 | 89 | return NULL; |
8ce83369 CB |
90 | |
91 | found = false; | |
ea918412 | 92 | |
e0732705 CS |
93 | while (getline(&line, &line_bufsz, proc_file) != -1) { |
94 | ret = sscanf(line, "CapBnd: %llx", &info->capability_mask); | |
8ce83369 CB |
95 | if (ret != EOF && ret == 1) { |
96 | found = true; | |
e0732705 CS |
97 | break; |
98 | } | |
99 | } | |
100 | ||
ffeeed8b CB |
101 | if (!found) |
102 | return log_error_errno(NULL, ENOENT, "Failed to read capability bounding set from %s", proc_fn); | |
e0732705 | 103 | |
d701d729 CB |
104 | info->lsm_ops = lsm_init(); |
105 | ||
af04d847 | 106 | info->lsm_label = info->lsm_ops->process_label_get(info->lsm_ops, pid); |
877f3a04 | 107 | info->ns_inherited = 0; |
b87ee312 CB |
108 | for (int i = 0; i < LXC_NS_MAX; i++) |
109 | info->ns_fd[i] = -EBADF; | |
e0732705 | 110 | |
ffeeed8b | 111 | return move_ptr(info); |
e0732705 CS |
112 | } |
113 | ||
ab919e5f | 114 | static inline void lxc_proc_close_ns_fd(struct attach_context *ctx) |
877f3a04 | 115 | { |
81102768 CB |
116 | for (int i = 0; i < LXC_NS_MAX; i++) |
117 | close_prot_errno_disarm(ctx->ns_fd[i]); | |
877f3a04 CB |
118 | } |
119 | ||
dd53c8af | 120 | static void put_attach_context(struct attach_context *ctx) |
fe4de9a6 | 121 | { |
7444657c | 122 | free_disarm(ctx->lsm_label); |
08ea9270 CB |
123 | |
124 | if (ctx->container) { | |
2c4ea790 | 125 | lxc_container_put(ctx->container); |
08ea9270 CB |
126 | ctx->container = NULL; |
127 | } | |
128 | ||
877f3a04 | 129 | lxc_proc_close_ns_fd(ctx); |
fe4de9a6 DE |
130 | free(ctx); |
131 | } | |
132 | ||
299d1198 CB |
133 | /** |
134 | * in_same_namespace - Check whether two processes are in the same namespace. | |
135 | * @pid1 - PID of the first process. | |
136 | * @pid2 - PID of the second process. | |
137 | * @ns - Name of the namespace to check. Must correspond to one of the names | |
138 | * for the namespaces as shown in /proc/<pid/ns/ | |
139 | * | |
140 | * If the two processes are not in the same namespace returns an fd to the | |
141 | * namespace of the second process identified by @pid2. If the two processes are | |
142 | * in the same namespace returns -EINVAL, -1 if an error occurred. | |
143 | */ | |
144 | static int in_same_namespace(pid_t pid1, pid_t pid2, const char *ns) | |
145 | { | |
644e7393 | 146 | __do_close int ns_fd1 = -EBADF, ns_fd2 = -EBADF; |
3cc629fe | 147 | int ret = -1; |
299d1198 CB |
148 | struct stat ns_st1, ns_st2; |
149 | ||
150 | ns_fd1 = lxc_preserve_ns(pid1, ns); | |
134284c3 CB |
151 | if (ns_fd1 < 0) { |
152 | /* The kernel does not support this namespace. This is not an | |
153 | * error. | |
154 | */ | |
155 | if (errno == ENOENT) | |
156 | return -EINVAL; | |
157 | ||
3cc629fe | 158 | return -1; |
134284c3 | 159 | } |
299d1198 CB |
160 | |
161 | ns_fd2 = lxc_preserve_ns(pid2, ns); | |
21d0acc2 | 162 | if (ns_fd2 < 0) |
3cc629fe | 163 | return -1; |
299d1198 CB |
164 | |
165 | ret = fstat(ns_fd1, &ns_st1); | |
21d0acc2 | 166 | if (ret < 0) |
3cc629fe | 167 | return -1; |
299d1198 CB |
168 | |
169 | ret = fstat(ns_fd2, &ns_st2); | |
21d0acc2 | 170 | if (ret < 0) |
3cc629fe | 171 | return -1; |
299d1198 CB |
172 | |
173 | /* processes are in the same namespace */ | |
3cc629fe CB |
174 | if ((ns_st1.st_dev == ns_st2.st_dev) && (ns_st1.st_ino == ns_st2.st_ino)) |
175 | return -EINVAL; | |
299d1198 CB |
176 | |
177 | /* processes are in different namespaces */ | |
3cc629fe | 178 | return move_fd(ns_fd2); |
299d1198 CB |
179 | } |
180 | ||
ab919e5f | 181 | static int lxc_attach_to_ns(pid_t pid, struct attach_context *ctx) |
99d50954 | 182 | { |
ffeeed8b CB |
183 | for (int i = 0; i < LXC_NS_MAX; i++) { |
184 | int ret; | |
99d50954 | 185 | |
877f3a04 | 186 | if (ctx->ns_fd[i] < 0) |
26818618 CB |
187 | continue; |
188 | ||
21d0acc2 | 189 | ret = setns(ctx->ns_fd[i], ns_info[i].clone_flag); |
ffeeed8b CB |
190 | if (ret < 0) |
191 | return log_error_errno(-1, | |
192 | errno, "Failed to attach to %s namespace of %d", | |
193 | ns_info[i].proc_name, pid); | |
99d50954 | 194 | |
299d1198 | 195 | DEBUG("Attached to %s namespace of %d", ns_info[i].proc_name, pid); |
99d50954 CS |
196 | } |
197 | ||
198 | return 0; | |
199 | } | |
200 | ||
e4103cf6 | 201 | int lxc_attach_remount_sys_proc(void) |
7a0b0b56 CS |
202 | { |
203 | int ret; | |
204 | ||
205 | ret = unshare(CLONE_NEWNS); | |
ffeeed8b CB |
206 | if (ret < 0) |
207 | return log_error_errno(-1, errno, "Failed to unshare mount namespace"); | |
7a0b0b56 | 208 | |
9e61fb1f CB |
209 | if (detect_shared_rootfs() && mount(NULL, "/", NULL, MS_SLAVE | MS_REC, NULL)) |
210 | SYSERROR("Failed to recursively turn root mount tree into dependent mount. Continuing..."); | |
2c6f3fc9 | 211 | |
8ce83369 | 212 | /* Assume /proc is always mounted, so remount it. */ |
7a0b0b56 | 213 | ret = umount2("/proc", MNT_DETACH); |
ffeeed8b CB |
214 | if (ret < 0) |
215 | return log_error_errno(-1, errno, "Failed to unmount /proc"); | |
7a0b0b56 | 216 | |
657256e0 | 217 | ret = mount_filesystem("proc", "/proc", 0); |
ffeeed8b CB |
218 | if (ret < 0) |
219 | return log_error_errno(-1, errno, "Failed to remount /proc"); | |
7a0b0b56 | 220 | |
ffeeed8b CB |
221 | /* |
222 | * Try to umount /sys. If it's not a mount point, we'll get EINVAL, then | |
8ce83369 | 223 | * we ignore it because it may not have been mounted in the first place. |
7a0b0b56 CS |
224 | */ |
225 | ret = umount2("/sys", MNT_DETACH); | |
ffeeed8b CB |
226 | if (ret < 0 && errno != EINVAL) |
227 | return log_error_errno(-1, errno, "Failed to unmount /sys"); | |
228 | ||
229 | /* Remount it. */ | |
657256e0 | 230 | if (ret == 0 && mount_filesystem("sysfs", "/sys", 0)) |
ffeeed8b | 231 | return log_error_errno(-1, errno, "Failed to remount /sys"); |
7a0b0b56 CS |
232 | |
233 | return 0; | |
234 | } | |
235 | ||
ab919e5f | 236 | static int lxc_attach_drop_privs(struct attach_context *ctx) |
e0732705 | 237 | { |
ffeeed8b | 238 | int last_cap; |
e0732705 | 239 | |
6f4f1937 | 240 | last_cap = lxc_caps_last_cap(); |
ffeeed8b | 241 | for (int cap = 0; cap <= last_cap; cap++) { |
e0732705 CS |
242 | if (ctx->capability_mask & (1LL << cap)) |
243 | continue; | |
244 | ||
b81689a1 | 245 | if (prctl(PR_CAPBSET_DROP, prctl_arg(cap), prctl_arg(0), |
ffeeed8b CB |
246 | prctl_arg(0), prctl_arg(0))) |
247 | return log_error_errno(-1, errno, "Failed to drop capability %d", cap); | |
ea918412 | 248 | |
94ac256f | 249 | TRACE("Dropped capability %d", cap); |
e0732705 CS |
250 | } |
251 | ||
252 | return 0; | |
253 | } | |
905022f7 | 254 | |
ab919e5f | 255 | static int lxc_attach_set_environment(struct attach_context *ctx, |
7385273f | 256 | enum lxc_attach_env_policy_t policy, |
6f4f1937 | 257 | char **extra_env, char **extra_keep) |
b3a39ba6 | 258 | { |
3d55242a | 259 | int ret; |
7385273f | 260 | struct lxc_list *iterator; |
261 | ||
799f96fd | 262 | if (policy == LXC_ATTACH_CLEAR_ENV) { |
3d5e9f48 | 263 | int path_kept = 0; |
6f4f1937 | 264 | char **extra_keep_store = NULL; |
3d5e9f48 CS |
265 | |
266 | if (extra_keep) { | |
267 | size_t count, i; | |
268 | ||
3d55242a CB |
269 | for (count = 0; extra_keep[count]; count++) |
270 | ; | |
3d5e9f48 | 271 | |
89b7bfe3 | 272 | extra_keep_store = zalloc(count * sizeof(char *)); |
3d55242a | 273 | if (!extra_keep_store) |
3d5e9f48 | 274 | return -1; |
3d55242a | 275 | |
3d5e9f48 CS |
276 | for (i = 0; i < count; i++) { |
277 | char *v = getenv(extra_keep[i]); | |
278 | if (v) { | |
279 | extra_keep_store[i] = strdup(v); | |
280 | if (!extra_keep_store[i]) { | |
3d5e9f48 CS |
281 | while (i > 0) |
282 | free(extra_keep_store[--i]); | |
ea918412 | 283 | |
3d5e9f48 CS |
284 | free(extra_keep_store); |
285 | return -1; | |
286 | } | |
3d55242a | 287 | |
3d5e9f48 CS |
288 | if (strcmp(extra_keep[i], "PATH") == 0) |
289 | path_kept = 1; | |
290 | } | |
3d5e9f48 CS |
291 | } |
292 | } | |
293 | ||
799f96fd | 294 | if (clearenv()) { |
a9cab7e3 | 295 | if (extra_keep_store) { |
3d55242a CB |
296 | char **p; |
297 | ||
a9cab7e3 CS |
298 | for (p = extra_keep_store; *p; p++) |
299 | free(*p); | |
3d55242a | 300 | |
a9cab7e3 CS |
301 | free(extra_keep_store); |
302 | } | |
3d55242a | 303 | |
ffeeed8b | 304 | return log_error(-1, "Failed to clear environment"); |
3d5e9f48 CS |
305 | } |
306 | ||
307 | if (extra_keep_store) { | |
308 | size_t i; | |
6f4f1937 | 309 | |
3d5e9f48 | 310 | for (i = 0; extra_keep[i]; i++) { |
acd4922e | 311 | if (extra_keep_store[i]) { |
3d55242a CB |
312 | ret = setenv(extra_keep[i], extra_keep_store[i], 1); |
313 | if (ret < 0) | |
a24c5678 | 314 | SYSWARN("Failed to set environment variable"); |
acd4922e | 315 | } |
ea918412 | 316 | |
3d5e9f48 CS |
317 | free(extra_keep_store[i]); |
318 | } | |
ea918412 | 319 | |
3d5e9f48 CS |
320 | free(extra_keep_store); |
321 | } | |
322 | ||
8ce83369 CB |
323 | /* Always set a default path; shells and execlp tend to be fine |
324 | * without it, but there is a disturbing number of C programs | |
325 | * out there that just assume that getenv("PATH") is never NULL | |
326 | * and then die a painful segfault death. | |
327 | */ | |
3d55242a CB |
328 | if (!path_kept) { |
329 | ret = setenv("PATH", "/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin", 1); | |
330 | if (ret < 0) | |
a24c5678 | 331 | SYSWARN("Failed to set environment variable"); |
3d55242a | 332 | } |
b3a39ba6 DW |
333 | } |
334 | ||
3d55242a | 335 | ret = putenv("container=lxc"); |
ffeeed8b | 336 | if (ret < 0) |
818a57fc | 337 | return log_warn(-1, "Failed to set environment variable"); |
b3a39ba6 | 338 | |
7385273f | 339 | /* Set container environment variables.*/ |
ab919e5f CB |
340 | if (ctx && ctx->container && ctx->container->lxc_conf) { |
341 | lxc_list_for_each(iterator, &ctx->container->lxc_conf->environment) { | |
3d55242a CB |
342 | char *env_tmp; |
343 | ||
344 | env_tmp = strdup((char *)iterator->elem); | |
345 | if (!env_tmp) | |
7385273f | 346 | return -1; |
7385273f | 347 | |
3d55242a | 348 | ret = putenv(env_tmp); |
ffeeed8b CB |
349 | if (ret < 0) |
350 | return log_error_errno(-1, errno, "Failed to set environment variable: %s", (char *)iterator->elem); | |
7385273f | 351 | } |
352 | } | |
353 | ||
8ce83369 | 354 | /* Set extra environment variables. */ |
3d5e9f48 CS |
355 | if (extra_env) { |
356 | for (; *extra_env; extra_env++) { | |
3d55242a | 357 | char *p; |
ea918412 | 358 | |
8ce83369 CB |
359 | /* We just assume the user knows what they are doing, so |
360 | * we don't do any checks. | |
361 | */ | |
3d55242a CB |
362 | p = strdup(*extra_env); |
363 | if (!p) | |
3d5e9f48 | 364 | return -1; |
3d55242a CB |
365 | |
366 | ret = putenv(p); | |
367 | if (ret < 0) | |
a24c5678 | 368 | SYSWARN("Failed to set environment variable"); |
3d5e9f48 CS |
369 | } |
370 | } | |
371 | ||
b3a39ba6 DW |
372 | return 0; |
373 | } | |
374 | ||
74a3920a | 375 | static char *lxc_attach_getpwshell(uid_t uid) |
905022f7 | 376 | { |
1b9c9f5b | 377 | __do_free char *line = NULL, *result = NULL; |
cd8f5663 | 378 | __do_fclose FILE *pipe_f = NULL; |
6f4f1937 | 379 | int fd, ret; |
905022f7 CS |
380 | pid_t pid; |
381 | int pipes[2]; | |
3fa23ac3 CB |
382 | bool found = false; |
383 | size_t line_bufsz = 0; | |
905022f7 | 384 | |
8ce83369 CB |
385 | /* We need to fork off a process that runs the getent program, and we |
386 | * need to capture its output, so we use a pipe for that purpose. | |
905022f7 | 387 | */ |
3fa23ac3 | 388 | ret = pipe2(pipes, O_CLOEXEC); |
905022f7 CS |
389 | if (ret < 0) |
390 | return NULL; | |
391 | ||
392 | pid = fork(); | |
393 | if (pid < 0) { | |
394 | close(pipes[0]); | |
395 | close(pipes[1]); | |
396 | return NULL; | |
397 | } | |
398 | ||
3fa23ac3 | 399 | if (!pid) { |
905022f7 CS |
400 | char uid_buf[32]; |
401 | char *arguments[] = { | |
402 | "getent", | |
403 | "passwd", | |
404 | uid_buf, | |
405 | NULL | |
406 | }; | |
407 | ||
408 | close(pipes[0]); | |
409 | ||
8ce83369 | 410 | /* We want to capture stdout. */ |
3fa23ac3 | 411 | ret = dup2(pipes[1], STDOUT_FILENO); |
905022f7 | 412 | close(pipes[1]); |
3fa23ac3 | 413 | if (ret < 0) |
ea918412 | 414 | _exit(EXIT_FAILURE); |
905022f7 | 415 | |
8ce83369 CB |
416 | /* Get rid of stdin/stderr, so we try to associate it with |
417 | * /dev/null. | |
905022f7 | 418 | */ |
3fa23ac3 | 419 | fd = open_devnull(); |
905022f7 | 420 | if (fd < 0) { |
3fa23ac3 CB |
421 | close(STDIN_FILENO); |
422 | close(STDERR_FILENO); | |
905022f7 | 423 | } else { |
3fa23ac3 | 424 | (void)dup3(fd, STDIN_FILENO, O_CLOEXEC); |
59f0e209 | 425 | (void)dup3(fd, STDERR_FILENO, O_CLOEXEC); |
905022f7 CS |
426 | close(fd); |
427 | } | |
428 | ||
8ce83369 | 429 | /* Finish argument list. */ |
3fa23ac3 CB |
430 | ret = snprintf(uid_buf, sizeof(uid_buf), "%ld", (long)uid); |
431 | if (ret <= 0 || ret >= sizeof(uid_buf)) | |
ea918412 | 432 | _exit(EXIT_FAILURE); |
905022f7 | 433 | |
8ce83369 | 434 | /* Try to run getent program. */ |
3fa23ac3 | 435 | (void)execvp("getent", arguments); |
ea918412 | 436 | _exit(EXIT_FAILURE); |
905022f7 | 437 | } |
3fa23ac3 CB |
438 | |
439 | close(pipes[1]); | |
440 | ||
4110345b | 441 | pipe_f = fdopen(pipes[0], "re"); |
cf4026f1 CB |
442 | if (!pipe_f) { |
443 | close(pipes[0]); | |
444 | goto reap_child; | |
445 | } | |
446 | /* Transfer ownership of pipes[0] to pipe_f. */ | |
447 | move_fd(pipes[0]); | |
448 | ||
3fa23ac3 CB |
449 | while (getline(&line, &line_bufsz, pipe_f) != -1) { |
450 | int i; | |
451 | long value; | |
452 | char *token; | |
453 | char *endptr = NULL, *saveptr = NULL; | |
454 | ||
455 | /* If we already found something, just continue to read | |
456 | * until the pipe doesn't deliver any more data, but | |
457 | * don't modify the existing data structure. | |
458 | */ | |
459 | if (found) | |
460 | continue; | |
461 | ||
18d4ffde | 462 | if (!line) |
463 | continue; | |
464 | ||
3fa23ac3 CB |
465 | /* Trim line on the right hand side. */ |
466 | for (i = strlen(line); i > 0 && (line[i - 1] == '\n' || line[i - 1] == '\r'); --i) | |
467 | line[i - 1] = '\0'; | |
468 | ||
469 | /* Split into tokens: first: user name. */ | |
470 | token = strtok_r(line, ":", &saveptr); | |
471 | if (!token) | |
472 | continue; | |
473 | ||
474 | /* next: dummy password field */ | |
475 | token = strtok_r(NULL, ":", &saveptr); | |
476 | if (!token) | |
477 | continue; | |
478 | ||
479 | /* next: user id */ | |
480 | token = strtok_r(NULL, ":", &saveptr); | |
481 | value = token ? strtol(token, &endptr, 10) : 0; | |
482 | if (!token || !endptr || *endptr || value == LONG_MIN || | |
ea918412 | 483 | value == LONG_MAX) |
3fa23ac3 CB |
484 | continue; |
485 | ||
486 | /* dummy sanity check: user id matches */ | |
487 | if ((uid_t)value != uid) | |
488 | continue; | |
489 | ||
490 | /* skip fields: gid, gecos, dir, go to next field 'shell' */ | |
491 | for (i = 0; i < 4; i++) { | |
492 | token = strtok_r(NULL, ":", &saveptr); | |
493 | if (!token) | |
494 | continue; | |
495 | } | |
ea918412 | 496 | |
3fa23ac3 CB |
497 | if (!token) |
498 | continue; | |
ea918412 | 499 | |
1b9c9f5b | 500 | free_disarm(result); |
3fa23ac3 CB |
501 | result = strdup(token); |
502 | ||
503 | /* Sanity check that there are no fields after that. */ | |
504 | token = strtok_r(NULL, ":", &saveptr); | |
505 | if (token) | |
506 | continue; | |
507 | ||
508 | found = true; | |
509 | } | |
ea918412 | 510 | |
cf4026f1 | 511 | reap_child: |
3fa23ac3 | 512 | ret = wait_for_pid(pid); |
1b9c9f5b | 513 | if (ret < 0) |
3fa23ac3 | 514 | return NULL; |
3fa23ac3 | 515 | |
1b9c9f5b | 516 | if (!found) |
3fa23ac3 | 517 | return NULL; |
3fa23ac3 | 518 | |
1b9c9f5b | 519 | return move_ptr(result); |
905022f7 | 520 | } |
cb3e61fa | 521 | |
6f4f1937 | 522 | static void lxc_attach_get_init_uidgid(uid_t *init_uid, gid_t *init_gid) |
cb3e61fa | 523 | { |
cd8f5663 CB |
524 | __do_free char *line = NULL; |
525 | __do_fclose FILE *proc_file = NULL; | |
604ca1c0 | 526 | char proc_fn[LXC_PROC_STATUS_LEN]; |
8ce83369 | 527 | int ret; |
cb3e61fa | 528 | size_t line_bufsz = 0; |
cb3e61fa | 529 | long value = -1; |
a5d657d3 CB |
530 | uid_t uid = LXC_INVALID_UID; |
531 | gid_t gid = LXC_INVALID_GID; | |
cb3e61fa | 532 | |
604ca1c0 CB |
533 | ret = snprintf(proc_fn, LXC_PROC_STATUS_LEN, "/proc/%d/status", 1); |
534 | if (ret < 0 || ret >= LXC_PROC_STATUS_LEN) | |
7fb45c93 | 535 | return; |
cb3e61fa | 536 | |
4110345b | 537 | proc_file = fopen(proc_fn, "re"); |
cb3e61fa CS |
538 | if (!proc_file) |
539 | return; | |
540 | ||
541 | while (getline(&line, &line_bufsz, proc_file) != -1) { | |
8ce83369 CB |
542 | /* Format is: real, effective, saved set user, fs we only care |
543 | * about real uid. | |
cb3e61fa CS |
544 | */ |
545 | ret = sscanf(line, "Uid: %ld", &value); | |
8ce83369 | 546 | if (ret != EOF && ret == 1) { |
6f4f1937 | 547 | uid = (uid_t)value; |
cb3e61fa CS |
548 | } else { |
549 | ret = sscanf(line, "Gid: %ld", &value); | |
8ce83369 | 550 | if (ret != EOF && ret == 1) |
6f4f1937 | 551 | gid = (gid_t)value; |
cb3e61fa | 552 | } |
ea918412 | 553 | |
a5d657d3 | 554 | if (uid != LXC_INVALID_UID && gid != LXC_INVALID_GID) |
cb3e61fa CS |
555 | break; |
556 | } | |
557 | ||
8ce83369 | 558 | /* Only override arguments if we found something. */ |
a5d657d3 | 559 | if (uid != LXC_INVALID_UID) |
cb3e61fa | 560 | *init_uid = uid; |
ea918412 | 561 | |
a5d657d3 | 562 | if (gid != LXC_INVALID_GID) |
cb3e61fa CS |
563 | *init_gid = gid; |
564 | ||
565 | /* TODO: we should also parse supplementary groups and use | |
8ce83369 CB |
566 | * setgroups() to set them. |
567 | */ | |
cb3e61fa | 568 | } |
9c4693b8 | 569 | |
d4db3d14 | 570 | static bool fetch_seccomp(struct lxc_container *c, lxc_attach_options_t *options) |
2c4ea790 | 571 | { |
cd8f5663 | 572 | __do_free char *path = NULL; |
d4db3d14 CB |
573 | int ret; |
574 | bool bret; | |
2eef2bda | 575 | |
6f4f1937 CB |
576 | if (!(options->namespaces & CLONE_NEWNS) || |
577 | !(options->attach_flags & LXC_ATTACH_LSM)) { | |
cca66e06 | 578 | free_disarm(c->lxc_conf->seccomp.seccomp); |
2c4ea790 | 579 | return true; |
bd4307f0 | 580 | } |
bd7b4e28 | 581 | |
2e812c16 | 582 | /* Remove current setting. */ |
d4db3d14 | 583 | if (!c->set_config_item(c, "lxc.seccomp.profile", "") && |
ea918412 | 584 | !c->set_config_item(c, "lxc.seccomp", "")) |
2c4ea790 | 585 | return false; |
bd7b4e28 | 586 | |
8ce83369 | 587 | /* Fetch the current profile path over the cmd interface. */ |
0b427da0 | 588 | path = c->get_running_config_item(c, "lxc.seccomp.profile"); |
bd7b4e28 | 589 | if (!path) { |
d4db3d14 | 590 | INFO("Failed to retrieve lxc.seccomp.profile"); |
ea918412 | 591 | |
0b427da0 | 592 | path = c->get_running_config_item(c, "lxc.seccomp"); |
cca66e06 CB |
593 | if (!path) |
594 | return log_info(true, "Failed to retrieve lxc.seccomp"); | |
bd7b4e28 SG |
595 | } |
596 | ||
8ce83369 | 597 | /* Copy the value into the new lxc_conf. */ |
d4db3d14 | 598 | bret = c->set_config_item(c, "lxc.seccomp.profile", path); |
d4db3d14 CB |
599 | if (!bret) |
600 | return false; | |
bd7b4e28 | 601 | |
8ce83369 | 602 | /* Attempt to parse the resulting config. */ |
d4db3d14 | 603 | ret = lxc_read_seccomp_config(c->lxc_conf); |
cca66e06 CB |
604 | if (ret < 0) |
605 | return log_error(false, "Failed to retrieve seccomp policy"); | |
2c4ea790 | 606 | |
cca66e06 | 607 | return log_info(true, "Retrieved seccomp policy"); |
2e812c16 CB |
608 | } |
609 | ||
6f4f1937 | 610 | static bool no_new_privs(struct lxc_container *c, lxc_attach_options_t *options) |
2e812c16 | 611 | { |
cd8f5663 | 612 | __do_free char *val = NULL; |
2e812c16 | 613 | |
2e812c16 | 614 | /* Remove current setting. */ |
02d3b72b CB |
615 | if (!c->set_config_item(c, "lxc.no_new_privs", "")) |
616 | return log_info(false, "Failed to unset lxc.no_new_privs"); | |
2e812c16 CB |
617 | |
618 | /* Retrieve currently active setting. */ | |
619 | val = c->get_running_config_item(c, "lxc.no_new_privs"); | |
02d3b72b CB |
620 | if (!val) |
621 | return log_info(false, "Failed to retrieve lxc.no_new_privs"); | |
2e812c16 CB |
622 | |
623 | /* Set currently active setting. */ | |
cd8f5663 | 624 | return c->set_config_item(c, "lxc.no_new_privs", val); |
2c4ea790 SH |
625 | } |
626 | ||
9b8e3c96 SH |
627 | static signed long get_personality(const char *name, const char *lxcpath) |
628 | { | |
7c737378 | 629 | __do_free char *p = NULL; |
9b8e3c96 | 630 | |
6f4f1937 | 631 | p = lxc_cmd_get_config_item(name, "lxc.arch", lxcpath); |
9b8e3c96 SH |
632 | if (!p) |
633 | return -1; | |
6f4f1937 | 634 | |
cd8f5663 | 635 | return lxc_config_parse_arch(p); |
9b8e3c96 SH |
636 | } |
637 | ||
a998454a CB |
638 | struct attach_clone_payload { |
639 | int ipc_socket; | |
cecf3e83 | 640 | int terminal_pts_fd; |
a998454a | 641 | lxc_attach_options_t *options; |
ab919e5f | 642 | struct attach_context *ctx; |
a998454a CB |
643 | lxc_attach_exec_t exec_function; |
644 | void *exec_payload; | |
645 | }; | |
646 | ||
ba2be1a8 CB |
647 | static void lxc_put_attach_clone_payload(struct attach_clone_payload *p) |
648 | { | |
81102768 | 649 | close_prot_errno_disarm(p->ipc_socket); |
cecf3e83 | 650 | close_prot_errno_disarm(p->terminal_pts_fd); |
ab919e5f | 651 | if (p->ctx) { |
dd53c8af | 652 | put_attach_context(p->ctx); |
ab919e5f | 653 | p->ctx = NULL; |
b21da190 | 654 | } |
ba2be1a8 CB |
655 | } |
656 | ||
dab02267 | 657 | __noreturn static void do_attach(struct attach_clone_payload *payload) |
a998454a | 658 | { |
427a8067 | 659 | int lsm_fd, ret; |
a998454a CB |
660 | uid_t new_uid; |
661 | gid_t new_gid; | |
936efc72 CB |
662 | uid_t ns_root_uid = 0; |
663 | gid_t ns_root_gid = 0; | |
a998454a | 664 | lxc_attach_options_t* options = payload->options; |
ab919e5f CB |
665 | struct attach_context *ctx = payload->ctx; |
666 | struct lxc_conf *conf = ctx->container->lxc_conf; | |
57de839f CB |
667 | bool needs_lsm = (options->namespaces & CLONE_NEWNS) && |
668 | (options->attach_flags & LXC_ATTACH_LSM) && | |
ab919e5f | 669 | ctx->lsm_label; |
8455e39e | 670 | char *lsm_label = NULL; |
a998454a CB |
671 | |
672 | /* A description of the purpose of this functionality is provided in the | |
673 | * lxc-attach(1) manual page. We have to remount here and not in the | |
674 | * parent process, otherwise /proc may not properly reflect the new pid | |
675 | * namespace. | |
676 | */ | |
677 | if (!(options->namespaces & CLONE_NEWNS) && | |
678 | (options->attach_flags & LXC_ATTACH_REMOUNT_PROC_SYS)) { | |
679 | ret = lxc_attach_remount_sys_proc(); | |
b75c344c CB |
680 | if (ret < 0) |
681 | goto on_error; | |
ea918412 | 682 | |
b75c344c | 683 | TRACE("Remounted \"/proc\" and \"/sys\""); |
a998454a CB |
684 | } |
685 | ||
5b514ce3 | 686 | /* Now perform additional attachments. */ |
a998454a | 687 | #if HAVE_SYS_PERSONALITY_H |
a998454a | 688 | if (options->attach_flags & LXC_ATTACH_SET_PERSONALITY) { |
b75c344c CB |
689 | long new_personality; |
690 | ||
691 | if (options->personality < 0) | |
ab919e5f | 692 | new_personality = ctx->personality; |
b75c344c CB |
693 | else |
694 | new_personality = options->personality; | |
ea918412 | 695 | |
a998454a | 696 | ret = personality(new_personality); |
b75c344c CB |
697 | if (ret < 0) |
698 | goto on_error; | |
ea918412 | 699 | |
b75c344c | 700 | TRACE("Set new personality"); |
a998454a CB |
701 | } |
702 | #endif | |
703 | ||
704 | if (options->attach_flags & LXC_ATTACH_DROP_CAPABILITIES) { | |
ab919e5f | 705 | ret = lxc_attach_drop_privs(ctx); |
b75c344c CB |
706 | if (ret < 0) |
707 | goto on_error; | |
ea918412 | 708 | |
b75c344c | 709 | TRACE("Dropped capabilities"); |
a998454a CB |
710 | } |
711 | ||
712 | /* Always set the environment (specify (LXC_ATTACH_KEEP_ENV, NULL, NULL) | |
713 | * if you want this to be a no-op). | |
714 | */ | |
ab919e5f | 715 | ret = lxc_attach_set_environment(ctx, |
7385273f | 716 | options->env_policy, |
a998454a CB |
717 | options->extra_env_vars, |
718 | options->extra_keep_env); | |
b75c344c CB |
719 | if (ret < 0) |
720 | goto on_error; | |
ea918412 | 721 | |
b75c344c | 722 | TRACE("Set up environment"); |
a998454a | 723 | |
57de839f CB |
724 | /* This remark only affects fully unprivileged containers: |
725 | * Receive fd for LSM security module before we set{g,u}id(). The reason | |
726 | * is that on set{g,u}id() the kernel will a) make us undumpable and b) | |
727 | * we will change our effective uid. This means our effective uid will | |
728 | * be different from the effective uid of the process that created us | |
729 | * which means that this processs no longer has capabilities in our | |
730 | * namespace including CAP_SYS_PTRACE. This means we will not be able to | |
731 | * read and /proc/<pid> files for the process anymore when /proc is | |
732 | * mounted with hidepid={1,2}. So let's get the lsm label fd before the | |
733 | * set{g,u}id(). | |
734 | */ | |
735 | if (needs_lsm) { | |
b75c344c | 736 | ret = lxc_abstract_unix_recv_fds(payload->ipc_socket, &lsm_fd, 1, NULL, 0); |
9044b79e | 737 | if (ret <= 0) { |
738 | if (ret < 0) | |
739 | SYSERROR("Failed to receive lsm label fd"); | |
740 | ||
b75c344c | 741 | goto on_error; |
9044b79e | 742 | } |
743 | ||
57de839f CB |
744 | TRACE("Received LSM label file descriptor %d from parent", lsm_fd); |
745 | } | |
746 | ||
08ea9270 | 747 | if (options->stdin_fd > 0 && isatty(options->stdin_fd)) { |
cd0a2b2f | 748 | ret = lxc_make_controlling_terminal(options->stdin_fd); |
08ea9270 CB |
749 | if (ret < 0) |
750 | goto on_error; | |
751 | } | |
752 | ||
b58214ac CB |
753 | if (!lxc_setgroups(0, NULL) && errno != EPERM) |
754 | goto on_error; | |
755 | ||
936efc72 CB |
756 | if (options->namespaces & CLONE_NEWUSER) { |
757 | /* Check whether nsuid 0 has a mapping. */ | |
758 | ns_root_uid = get_ns_uid(0); | |
ea918412 | 759 | |
936efc72 CB |
760 | /* Check whether nsgid 0 has a mapping. */ |
761 | ns_root_gid = get_ns_gid(0); | |
a998454a | 762 | |
936efc72 CB |
763 | /* If there's no mapping for nsuid 0 try to retrieve the nsuid |
764 | * init was started with. | |
765 | */ | |
766 | if (ns_root_uid == LXC_INVALID_UID) | |
767 | lxc_attach_get_init_uidgid(&ns_root_uid, &ns_root_gid); | |
ea918412 | 768 | |
936efc72 CB |
769 | if (ns_root_uid == LXC_INVALID_UID) |
770 | goto on_error; | |
a998454a | 771 | |
464c4611 | 772 | if (!lxc_switch_uid_gid(ns_root_uid, ns_root_gid)) |
b75c344c | 773 | goto on_error; |
a998454a CB |
774 | } |
775 | ||
936efc72 CB |
776 | /* Set {u,g}id. */ |
777 | if (options->uid != LXC_INVALID_UID) | |
778 | new_uid = options->uid; | |
779 | else | |
780 | new_uid = ns_root_uid; | |
781 | ||
782 | if (options->gid != LXC_INVALID_GID) | |
783 | new_gid = options->gid; | |
784 | else | |
785 | new_gid = ns_root_gid; | |
786 | ||
57de839f | 787 | if (needs_lsm) { |
d3ba7c98 | 788 | bool on_exec; |
a998454a CB |
789 | |
790 | /* Change into our new LSM profile. */ | |
d3ba7c98 | 791 | on_exec = options->attach_flags & LXC_ATTACH_LSM_EXEC ? true : false; |
65129087 CB |
792 | if (options->attach_flags & LXC_ATTACH_LSM_LABEL) |
793 | lsm_label = options->lsm_label; | |
794 | if (!lsm_label) | |
ab919e5f CB |
795 | lsm_label = ctx->lsm_label; |
796 | ret = ctx->lsm_ops->process_label_set_at(ctx->lsm_ops, lsm_fd, | |
797 | lsm_label, on_exec); | |
57de839f | 798 | close(lsm_fd); |
b75c344c CB |
799 | if (ret < 0) |
800 | goto on_error; | |
ea918412 | 801 | |
ab919e5f | 802 | TRACE("Set %s LSM label to \"%s\"", ctx->lsm_ops->name, ctx->lsm_label); |
a998454a CB |
803 | } |
804 | ||
ab919e5f | 805 | if ((ctx->container && conf && conf->no_new_privs) || |
6ce8e678 AL |
806 | (options->attach_flags & LXC_ATTACH_NO_NEW_PRIVS)) { |
807 | ret = prctl(PR_SET_NO_NEW_PRIVS, prctl_arg(1), prctl_arg(0), | |
808 | prctl_arg(0), prctl_arg(0)); | |
809 | if (ret < 0) | |
810 | goto on_error; | |
811 | ||
812 | TRACE("Set PR_SET_NO_NEW_PRIVS"); | |
813 | } | |
814 | ||
ab919e5f | 815 | if (ctx->container && conf && conf->seccomp.seccomp) { |
cdb2a47f | 816 | ret = lxc_seccomp_load(conf); |
b75c344c CB |
817 | if (ret < 0) |
818 | goto on_error; | |
ea918412 | 819 | |
b75c344c | 820 | TRACE("Loaded seccomp profile"); |
cdb2a47f | 821 | |
c3e3c21a CB |
822 | ret = lxc_seccomp_send_notifier_fd(&conf->seccomp, payload->ipc_socket); |
823 | if (ret < 0) | |
824 | goto on_error; | |
a998454a | 825 | } |
ea918412 | 826 | |
578d4b62 | 827 | close_prot_errno_disarm(payload->ipc_socket); |
dd53c8af | 828 | put_attach_context(ctx); |
ab919e5f | 829 | payload->ctx = NULL; |
a998454a CB |
830 | |
831 | /* The following is done after the communication socket is shut down. | |
832 | * That way, all errors that might (though unlikely) occur up until this | |
833 | * point will have their messages printed to the original stderr (if | |
834 | * logging is so configured) and not the fd the user supplied, if any. | |
835 | */ | |
836 | ||
837 | /* Fd handling for stdin, stdout and stderr; ignore errors here, user | |
838 | * may want to make sure the fds are closed, for example. | |
839 | */ | |
08ea9270 | 840 | if (options->stdin_fd >= 0 && options->stdin_fd != STDIN_FILENO) |
b4959848 CB |
841 | if (dup2(options->stdin_fd, STDIN_FILENO)) |
842 | DEBUG("Failed to replace stdin with %d", options->stdin_fd); | |
08ea9270 CB |
843 | |
844 | if (options->stdout_fd >= 0 && options->stdout_fd != STDOUT_FILENO) | |
b4959848 CB |
845 | if (dup2(options->stdout_fd, STDOUT_FILENO)) |
846 | DEBUG("Failed to replace stdout with %d", options->stdin_fd); | |
08ea9270 CB |
847 | |
848 | if (options->stderr_fd >= 0 && options->stderr_fd != STDERR_FILENO) | |
b4959848 CB |
849 | if (dup2(options->stderr_fd, STDERR_FILENO)) |
850 | DEBUG("Failed to replace stderr with %d", options->stdin_fd); | |
a998454a CB |
851 | |
852 | /* close the old fds */ | |
08ea9270 | 853 | if (options->stdin_fd > STDERR_FILENO) |
a998454a | 854 | close(options->stdin_fd); |
08ea9270 CB |
855 | |
856 | if (options->stdout_fd > STDERR_FILENO) | |
a998454a | 857 | close(options->stdout_fd); |
08ea9270 CB |
858 | |
859 | if (options->stderr_fd > STDERR_FILENO) | |
a998454a CB |
860 | close(options->stderr_fd); |
861 | ||
427a8067 CB |
862 | /* |
863 | * Try to remove FD_CLOEXEC flag from stdin/stdout/stderr, but also | |
a998454a CB |
864 | * here, ignore errors. |
865 | */ | |
427a8067 | 866 | for (int fd = STDIN_FILENO; fd <= STDERR_FILENO; fd++) { |
3f62938a | 867 | ret = fd_cloexec(fd, false); |
b75c344c CB |
868 | if (ret < 0) { |
869 | SYSERROR("Failed to clear FD_CLOEXEC from file descriptor %d", fd); | |
870 | goto on_error; | |
871 | } | |
a998454a CB |
872 | } |
873 | ||
9e84479f | 874 | if (options->attach_flags & LXC_ATTACH_TERMINAL) { |
cecf3e83 | 875 | ret = lxc_terminal_prepare_login(payload->terminal_pts_fd); |
ba2be1a8 | 876 | if (ret < 0) { |
cecf3e83 | 877 | SYSERROR("Failed to prepare terminal file descriptor %d", payload->terminal_pts_fd); |
ba2be1a8 CB |
878 | goto on_error; |
879 | } | |
ea918412 | 880 | |
cecf3e83 | 881 | TRACE("Prepared terminal file descriptor %d", payload->terminal_pts_fd); |
ba2be1a8 CB |
882 | } |
883 | ||
936efc72 CB |
884 | /* Avoid unnecessary syscalls. */ |
885 | if (new_uid == ns_root_uid) | |
886 | new_uid = LXC_INVALID_UID; | |
887 | ||
888 | if (new_gid == ns_root_gid) | |
889 | new_gid = LXC_INVALID_GID; | |
c353b0b9 | 890 | |
6aff5157 | 891 | /* Make sure that the processes STDIO is correctly owned by the user that we are switching to */ |
c353b0b9 CB |
892 | ret = fix_stdio_permissions(new_uid); |
893 | if (ret) | |
a2c26bef | 894 | INFO("Failed to adjust stdio permissions"); |
936efc72 | 895 | |
464c4611 | 896 | if (!lxc_switch_uid_gid(new_uid, new_gid)) |
936efc72 CB |
897 | goto on_error; |
898 | ||
a998454a | 899 | /* We're done, so we can now do whatever the user intended us to do. */ |
c7ac2e1c | 900 | _exit(payload->exec_function(payload->exec_payload)); |
b75c344c CB |
901 | |
902 | on_error: | |
ba2be1a8 | 903 | lxc_put_attach_clone_payload(payload); |
dab02267 | 904 | ERROR("Failed to attach to container"); |
c7ac2e1c | 905 | _exit(EXIT_FAILURE); |
a998454a CB |
906 | } |
907 | ||
f797f05e | 908 | static int lxc_attach_terminal(const char *name, const char *lxcpath, struct lxc_conf *conf, |
9e84479f | 909 | struct lxc_terminal *terminal) |
ba2be1a8 CB |
910 | { |
911 | int ret; | |
912 | ||
9e84479f | 913 | lxc_terminal_init(terminal); |
ba2be1a8 | 914 | |
8ea93a0f | 915 | ret = lxc_terminal_create(name, lxcpath, conf, terminal); |
c2af3a15 CB |
916 | if (ret < 0) |
917 | return log_error(-1, "Failed to create terminal"); | |
ba2be1a8 | 918 | |
ba2be1a8 | 919 | return 0; |
ba2be1a8 CB |
920 | } |
921 | ||
9e84479f CB |
922 | static int lxc_attach_terminal_mainloop_init(struct lxc_terminal *terminal, |
923 | struct lxc_epoll_descr *descr) | |
ba2be1a8 CB |
924 | { |
925 | int ret; | |
926 | ||
927 | ret = lxc_mainloop_open(descr); | |
c2af3a15 CB |
928 | if (ret < 0) |
929 | return log_error(-1, "Failed to create mainloop"); | |
ba2be1a8 | 930 | |
9e84479f | 931 | ret = lxc_terminal_mainloop_add(descr, terminal); |
ba2be1a8 | 932 | if (ret < 0) { |
ba2be1a8 | 933 | lxc_mainloop_close(descr); |
c2af3a15 | 934 | return log_error(-1, "Failed to add handlers to mainloop"); |
ba2be1a8 CB |
935 | } |
936 | ||
937 | return 0; | |
938 | } | |
939 | ||
36a94ce8 | 940 | static inline void lxc_attach_terminal_close_ptx(struct lxc_terminal *terminal) |
ba2be1a8 | 941 | { |
36a94ce8 | 942 | close_prot_errno_disarm(terminal->ptx); |
ba2be1a8 CB |
943 | } |
944 | ||
cecf3e83 | 945 | static inline void lxc_attach_terminal_close_pts(struct lxc_terminal *terminal) |
ba2be1a8 | 946 | { |
41808e20 | 947 | close_prot_errno_disarm(terminal->pty); |
ba2be1a8 CB |
948 | } |
949 | ||
9e84479f | 950 | static inline void lxc_attach_terminal_close_peer(struct lxc_terminal *terminal) |
ba2be1a8 | 951 | { |
19a3e906 | 952 | close_prot_errno_disarm(terminal->peer); |
ba2be1a8 CB |
953 | } |
954 | ||
9e84479f | 955 | static inline void lxc_attach_terminal_close_log(struct lxc_terminal *terminal) |
ba2be1a8 | 956 | { |
19a3e906 | 957 | close_prot_errno_disarm(terminal->log_fd); |
ba2be1a8 CB |
958 | } |
959 | ||
908fbc1a CB |
960 | int lxc_attach(struct lxc_container *container, lxc_attach_exec_t exec_function, |
961 | void *exec_payload, lxc_attach_options_t *options, | |
962 | pid_t *attached_process) | |
9c4693b8 | 963 | { |
e11f5b8c | 964 | __do_free char *cwd = NULL; |
6f9fe5d0 CB |
965 | int ret_parent = -1; |
966 | struct attach_clone_payload payload = {}; | |
967 | struct lxc_epoll_descr descr = {}; | |
877f3a04 | 968 | int i, ret, status; |
6f9fe5d0 | 969 | char *name, *lxcpath, *new_cwd; |
9c4693b8 | 970 | int ipc_sockets[2]; |
9b8e3c96 | 971 | signed long personality; |
6f9fe5d0 | 972 | pid_t attached_pid, init_pid, pid, to_cleanup_pid; |
ab919e5f | 973 | struct attach_context *ctx; |
9e84479f | 974 | struct lxc_terminal terminal; |
1cce35e6 | 975 | struct lxc_conf *conf; |
9c4693b8 | 976 | |
877f3a04 | 977 | ret = access("/proc/self/ns", X_OK); |
c2af3a15 CB |
978 | if (ret) |
979 | return log_error_errno(-1, errno, "Does this kernel version support namespaces?"); | |
877f3a04 | 980 | |
908fbc1a | 981 | if (!container) |
540a2f70 | 982 | return ret_set_errno(-1, EINVAL); |
908fbc1a CB |
983 | |
984 | if (!lxc_container_get(container)) | |
540a2f70 | 985 | return ret_set_errno(-1, EINVAL); |
908fbc1a CB |
986 | |
987 | name = container->name; | |
988 | lxcpath = container->config_path; | |
989 | ||
9c4693b8 CS |
990 | if (!options) |
991 | options = &attach_static_default_options; | |
992 | ||
993 | init_pid = lxc_cmd_get_init_pid(name, lxcpath); | |
994 | if (init_pid < 0) { | |
908fbc1a | 995 | lxc_container_put(container); |
c2af3a15 | 996 | return log_error(-1, "Failed to get init pid"); |
9c4693b8 CS |
997 | } |
998 | ||
dd53c8af | 999 | ctx = get_attach_context(init_pid); |
ab919e5f | 1000 | if (!ctx) { |
6f4f1937 | 1001 | ERROR("Failed to get context of init process: %ld", (long)init_pid); |
908fbc1a | 1002 | lxc_container_put(container); |
9c4693b8 CS |
1003 | return -1; |
1004 | } | |
1005 | ||
ab919e5f | 1006 | ctx->container = container; |
908fbc1a | 1007 | |
9b8e3c96 | 1008 | personality = get_personality(name, lxcpath); |
ab919e5f | 1009 | if (ctx->personality < 0) { |
6f4f1937 | 1010 | ERROR("Failed to get personality of the container"); |
dd53c8af | 1011 | put_attach_context(ctx); |
9b8e3c96 SH |
1012 | return -1; |
1013 | } | |
ab919e5f | 1014 | ctx->personality = personality; |
9b8e3c96 | 1015 | |
ab919e5f CB |
1016 | if (!ctx->container->lxc_conf) { |
1017 | ctx->container->lxc_conf = lxc_conf_init(); | |
1018 | if (!ctx->container->lxc_conf) { | |
dd53c8af | 1019 | put_attach_context(ctx); |
ea918412 | 1020 | return -1; |
62de1db6 | 1021 | } |
ba773996 | 1022 | } |
ab919e5f | 1023 | conf = ctx->container->lxc_conf; |
a9909116 CB |
1024 | if (!conf) |
1025 | return log_error_errno(-EINVAL, EINVAL, "Missing container confifg"); | |
ba773996 | 1026 | |
ab919e5f | 1027 | if (!fetch_seccomp(ctx->container, options)) |
ae026f55 | 1028 | WARN("Failed to get seccomp policy"); |
2c4ea790 | 1029 | |
ab919e5f | 1030 | if (!no_new_privs(ctx->container, options)) |
ae026f55 | 1031 | WARN("Could not determine whether PR_SET_NO_NEW_PRIVS is set"); |
2e812c16 | 1032 | |
9c4693b8 CS |
1033 | cwd = getcwd(NULL, 0); |
1034 | ||
8ce83369 CB |
1035 | /* Determine which namespaces the container was created with |
1036 | * by asking lxc-start, if necessary. | |
9c4693b8 CS |
1037 | */ |
1038 | if (options->namespaces == -1) { | |
1039 | options->namespaces = lxc_cmd_get_clone_flags(name, lxcpath); | |
1040 | /* call failed */ | |
1041 | if (options->namespaces == -1) { | |
8ce83369 | 1042 | ERROR("Failed to automatically determine the " |
877f3a04 | 1043 | "namespaces which the container uses"); |
dd53c8af | 1044 | put_attach_context(ctx); |
9c4693b8 CS |
1045 | return -1; |
1046 | } | |
877f3a04 CB |
1047 | |
1048 | for (i = 0; i < LXC_NS_MAX; i++) { | |
1049 | if (ns_info[i].clone_flag & CLONE_NEWCGROUP) | |
1050 | if (!(options->attach_flags & LXC_ATTACH_MOVE_TO_CGROUP) || | |
1051 | !cgns_supported()) | |
1052 | continue; | |
1053 | ||
1054 | if (ns_info[i].clone_flag & options->namespaces) | |
1055 | continue; | |
1056 | ||
ab919e5f | 1057 | ctx->ns_inherited |= ns_info[i].clone_flag; |
877f3a04 CB |
1058 | } |
1059 | } | |
1060 | ||
0059379f | 1061 | pid = lxc_raw_getpid(); |
ea918412 | 1062 | |
877f3a04 | 1063 | for (i = 0; i < LXC_NS_MAX; i++) { |
ea918412 | 1064 | int j; |
877f3a04 CB |
1065 | |
1066 | if (options->namespaces & ns_info[i].clone_flag) | |
ab919e5f CB |
1067 | ctx->ns_fd[i] = lxc_preserve_ns(init_pid, ns_info[i].proc_name); |
1068 | else if (ctx->ns_inherited & ns_info[i].clone_flag) | |
1069 | ctx->ns_fd[i] = in_same_namespace(pid, init_pid, ns_info[i].proc_name); | |
877f3a04 CB |
1070 | else |
1071 | continue; | |
ea918412 | 1072 | |
ab919e5f | 1073 | if (ctx->ns_fd[i] >= 0) |
877f3a04 CB |
1074 | continue; |
1075 | ||
ab919e5f | 1076 | if (ctx->ns_fd[i] == -EINVAL) { |
877f3a04 CB |
1077 | DEBUG("Inheriting %s namespace from %d", |
1078 | ns_info[i].proc_name, pid); | |
ab919e5f | 1079 | ctx->ns_inherited &= ~ns_info[i].clone_flag; |
877f3a04 CB |
1080 | continue; |
1081 | } | |
1082 | ||
1083 | /* We failed to preserve the namespace. */ | |
ea918412 | 1084 | SYSERROR("Failed to attach to %s namespace of %d", |
1085 | ns_info[i].proc_name, pid); | |
1086 | ||
877f3a04 CB |
1087 | /* Close all already opened file descriptors before we return an |
1088 | * error, so we don't leak them. | |
1089 | */ | |
1090 | for (j = 0; j < i; j++) | |
ab919e5f | 1091 | close(ctx->ns_fd[j]); |
877f3a04 | 1092 | |
dd53c8af | 1093 | put_attach_context(ctx); |
877f3a04 | 1094 | return -1; |
9c4693b8 CS |
1095 | } |
1096 | ||
9e84479f | 1097 | if (options->attach_flags & LXC_ATTACH_TERMINAL) { |
f797f05e | 1098 | ret = lxc_attach_terminal(name, lxcpath, conf, &terminal); |
ba2be1a8 | 1099 | if (ret < 0) { |
9e84479f | 1100 | ERROR("Failed to setup new terminal"); |
dd53c8af | 1101 | put_attach_context(ctx); |
ba2be1a8 CB |
1102 | return -1; |
1103 | } | |
1104 | ||
9e84479f | 1105 | terminal.log_fd = options->log_fd; |
c948657b | 1106 | } else { |
9e84479f | 1107 | lxc_terminal_init(&terminal); |
ba2be1a8 CB |
1108 | } |
1109 | ||
8ce83369 CB |
1110 | /* Create a socket pair for IPC communication; set SOCK_CLOEXEC in order |
1111 | * to make sure we don't irritate other threads that want to fork+exec | |
1112 | * away | |
9c4693b8 CS |
1113 | * |
1114 | * IMPORTANT: if the initial process is multithreaded and another call | |
1115 | * just fork()s away without exec'ing directly after, the socket fd will | |
1116 | * exist in the forked process from the other thread and any close() in | |
8ce83369 | 1117 | * our own child process will not really cause the socket to close |
1d801260 | 1118 | * properly, potentially causing the parent to hang. |
9c4693b8 CS |
1119 | * |
1120 | * For this reason, while IPC is still active, we have to use shutdown() | |
8ce83369 CB |
1121 | * if the child exits prematurely in order to signal that the socket is |
1122 | * closed and cannot assume that the child exiting will automatically do | |
1123 | * that. | |
9c4693b8 CS |
1124 | * |
1125 | * IPC mechanism: (X is receiver) | |
1126 | * initial process intermediate attached | |
1127 | * X <--- send pid of | |
1128 | * attached proc, | |
1129 | * then exit | |
1130 | * send 0 ------------------------------------> X | |
1131 | * [do initialization] | |
1132 | * X <------------------------------------ send 1 | |
1133 | * [add to cgroup, ...] | |
1134 | * send 2 ------------------------------------> X | |
81f466d0 CB |
1135 | * [set LXC_ATTACH_NO_NEW_PRIVS] |
1136 | * X <------------------------------------ send 3 | |
1137 | * [open LSM label fd] | |
1138 | * send 4 ------------------------------------> X | |
1139 | * [set LSM label] | |
9c4693b8 CS |
1140 | * close socket close socket |
1141 | * run program | |
1142 | */ | |
1143 | ret = socketpair(PF_LOCAL, SOCK_STREAM | SOCK_CLOEXEC, 0, ipc_sockets); | |
1144 | if (ret < 0) { | |
ae026f55 | 1145 | SYSERROR("Could not set up required IPC mechanism for attaching"); |
dd53c8af | 1146 | put_attach_context(ctx); |
9c4693b8 CS |
1147 | return -1; |
1148 | } | |
1149 | ||
e3f0e436 CB |
1150 | /* Create intermediate subprocess, two reasons: |
1151 | * 1. We can't setns() in the child itself, since we want to make | |
8ce83369 | 1152 | * sure we are properly attached to the pidns. |
e3f0e436 | 1153 | * 2. Also, the initial thread has to put the attached process |
8ce83369 CB |
1154 | * into the cgroup, which we can only do if we didn't already |
1155 | * setns() (otherwise, user namespaces will hate us). | |
9c4693b8 CS |
1156 | */ |
1157 | pid = fork(); | |
9c4693b8 | 1158 | if (pid < 0) { |
ae026f55 | 1159 | SYSERROR("Failed to create first subprocess"); |
dd53c8af | 1160 | put_attach_context(ctx); |
9c4693b8 CS |
1161 | return -1; |
1162 | } | |
1163 | ||
4f25e72f | 1164 | if (pid == 0) { |
ba2be1a8 | 1165 | /* close unneeded file descriptors */ |
4f25e72f | 1166 | close_prot_errno_disarm(ipc_sockets[0]); |
2202afc9 | 1167 | |
4f25e72f CB |
1168 | if (options->attach_flags & LXC_ATTACH_TERMINAL) { |
1169 | lxc_attach_terminal_close_ptx(&terminal); | |
1170 | lxc_attach_terminal_close_peer(&terminal); | |
1171 | lxc_attach_terminal_close_log(&terminal); | |
f4364484 SG |
1172 | } |
1173 | ||
4f25e72f CB |
1174 | /* Wait for the parent to have setup cgroups. */ |
1175 | ret = lxc_read_nointr(ipc_sockets[1], &status, sizeof(status)); | |
1176 | if (ret != sizeof(status)) { | |
1177 | shutdown(ipc_sockets[1], SHUT_RDWR); | |
dd53c8af | 1178 | put_attach_context(ctx); |
4f25e72f | 1179 | _exit(EXIT_FAILURE); |
bb2ada6f CB |
1180 | } |
1181 | ||
4f25e72f CB |
1182 | TRACE("Intermediate process starting to initialize"); |
1183 | ||
1184 | /* Attach now, create another subprocess later, since pid namespaces | |
1185 | * only really affect the children of the current process. | |
1186 | */ | |
ab919e5f | 1187 | ret = lxc_attach_to_ns(init_pid, ctx); |
4f25e72f CB |
1188 | if (ret < 0) { |
1189 | ERROR("Failed to enter namespaces"); | |
1190 | shutdown(ipc_sockets[1], SHUT_RDWR); | |
dd53c8af | 1191 | put_attach_context(ctx); |
4f25e72f | 1192 | _exit(EXIT_FAILURE); |
ba2be1a8 CB |
1193 | } |
1194 | ||
4f25e72f | 1195 | /* close namespace file descriptors */ |
ab919e5f | 1196 | lxc_proc_close_ns_fd(ctx); |
ea918412 | 1197 | |
4f25e72f CB |
1198 | /* Attach succeeded, try to cwd. */ |
1199 | if (options->initial_cwd) | |
1200 | new_cwd = options->initial_cwd; | |
1201 | else | |
1202 | new_cwd = cwd; | |
1203 | if (new_cwd) { | |
1204 | ret = chdir(new_cwd); | |
1205 | if (ret < 0) | |
1206 | WARN("Could not change directory to \"%s\"", new_cwd); | |
ba2be1a8 | 1207 | } |
c6d09e15 | 1208 | |
4f25e72f | 1209 | /* Create attached process. */ |
76783714 CB |
1210 | payload.ipc_socket = ipc_sockets[1]; |
1211 | payload.options = options; | |
ab919e5f | 1212 | payload.ctx = ctx; |
4f25e72f | 1213 | payload.terminal_pts_fd = terminal.pty; |
76783714 CB |
1214 | payload.exec_function = exec_function; |
1215 | payload.exec_payload = exec_payload; | |
4f25e72f CB |
1216 | |
1217 | pid = lxc_raw_clone(CLONE_PARENT, NULL); | |
1218 | if (pid < 0) { | |
1219 | SYSERROR("Failed to clone attached process"); | |
1220 | shutdown(ipc_sockets[1], SHUT_RDWR); | |
dd53c8af | 1221 | put_attach_context(ctx); |
4f25e72f CB |
1222 | _exit(EXIT_FAILURE); |
1223 | } | |
f4364484 | 1224 | |
4f25e72f CB |
1225 | if (pid == 0) { |
1226 | if (options->attach_flags & LXC_ATTACH_TERMINAL) { | |
1227 | ret = lxc_terminal_signal_sigmask_safe_blocked(&terminal); | |
1228 | if (ret < 0) { | |
1229 | SYSERROR("Failed to reset signal mask"); | |
1230 | _exit(EXIT_FAILURE); | |
1231 | } | |
1232 | } | |
ea918412 | 1233 | |
dab02267 | 1234 | do_attach(&payload); |
62183f1a | 1235 | } |
2eef2bda | 1236 | |
4f25e72f CB |
1237 | if (options->attach_flags & LXC_ATTACH_TERMINAL) |
1238 | lxc_attach_terminal_close_pts(&terminal); | |
ea918412 | 1239 | |
4f25e72f CB |
1240 | /* Tell grandparent the pid of the pid of the newly created child. */ |
1241 | ret = lxc_write_nointr(ipc_sockets[1], &pid, sizeof(pid)); | |
1242 | if (ret != sizeof(pid)) { | |
1243 | /* If this really happens here, this is very unfortunate, since | |
1244 | * the parent will not know the pid of the attached process and | |
1245 | * will not be able to wait for it (and we won't either due to | |
1246 | * CLONE_PARENT) so the parent won't be able to reap it and the | |
1247 | * attached process will remain a zombie. | |
1248 | */ | |
1249 | shutdown(ipc_sockets[1], SHUT_RDWR); | |
dd53c8af | 1250 | put_attach_context(ctx); |
4f25e72f CB |
1251 | _exit(EXIT_FAILURE); |
1252 | } | |
9c4693b8 | 1253 | |
4f25e72f | 1254 | TRACE("Sending pid %d of attached process", pid); |
9c4693b8 | 1255 | |
4f25e72f | 1256 | /* The rest is in the hands of the initial and the attached process. */ |
dd53c8af | 1257 | put_attach_context(ctx); |
4f25e72f CB |
1258 | _exit(EXIT_SUCCESS); |
1259 | } | |
6f4f1937 | 1260 | |
4f25e72f | 1261 | to_cleanup_pid = pid; |
ea918412 | 1262 | |
4f25e72f CB |
1263 | /* close unneeded file descriptors */ |
1264 | close(ipc_sockets[1]); | |
e11f5b8c | 1265 | free_disarm(cwd); |
ab919e5f | 1266 | lxc_proc_close_ns_fd(ctx); |
4f25e72f CB |
1267 | if (options->attach_flags & LXC_ATTACH_TERMINAL) |
1268 | lxc_attach_terminal_close_pts(&terminal); | |
81f466d0 | 1269 | |
4f25e72f CB |
1270 | /* Attach to cgroup, if requested. */ |
1271 | if (options->attach_flags & LXC_ATTACH_MOVE_TO_CGROUP) { | |
1272 | /* | |
1273 | * If this is the unified hierarchy cgroup_attach() is | |
1274 | * enough. | |
1275 | */ | |
1276 | ret = cgroup_attach(conf, name, lxcpath, pid); | |
1277 | if (ret) { | |
1278 | call_cleaner(cgroup_exit) struct cgroup_ops *cgroup_ops = NULL; | |
9044b79e | 1279 | |
4f25e72f CB |
1280 | cgroup_ops = cgroup_init(conf); |
1281 | if (!cgroup_ops) | |
1282 | goto on_error; | |
9044b79e | 1283 | |
4f25e72f CB |
1284 | if (!cgroup_ops->attach(cgroup_ops, conf, name, lxcpath, pid)) |
1285 | goto on_error; | |
81f466d0 | 1286 | } |
4f25e72f CB |
1287 | TRACE("Moved intermediate process %d into container's cgroups", pid); |
1288 | } | |
81f466d0 | 1289 | |
4f25e72f CB |
1290 | /* Setup /proc limits */ |
1291 | if (!lxc_list_empty(&conf->procs)) { | |
1292 | ret = setup_proc_filesystem(&conf->procs, pid); | |
1293 | if (ret < 0) | |
1294 | goto on_error; | |
4f3b6a85 CB |
1295 | |
1296 | TRACE("Setup /proc/%d settings", pid); | |
4f25e72f | 1297 | } |
cdb2a47f | 1298 | |
4f25e72f CB |
1299 | /* Setup resource limits */ |
1300 | if (!lxc_list_empty(&conf->limits)) { | |
1301 | ret = setup_resource_limits(&conf->limits, pid); | |
1302 | if (ret < 0) | |
1303 | goto on_error; | |
4f3b6a85 CB |
1304 | |
1305 | TRACE("Setup resource limits"); | |
4f25e72f | 1306 | } |
cdb2a47f | 1307 | |
4f25e72f CB |
1308 | if (options->attach_flags & LXC_ATTACH_TERMINAL) { |
1309 | ret = lxc_attach_terminal_mainloop_init(&terminal, &descr); | |
1310 | if (ret < 0) | |
1311 | goto on_error; | |
9c4693b8 | 1312 | |
4f25e72f CB |
1313 | TRACE("Initialized terminal mainloop"); |
1314 | } | |
9c4693b8 | 1315 | |
4f25e72f CB |
1316 | /* Let the child process know to go ahead. */ |
1317 | status = 0; | |
1318 | ret = lxc_write_nointr(ipc_sockets[0], &status, sizeof(status)); | |
1319 | if (ret != sizeof(status)) | |
1320 | goto close_mainloop; | |
ba2be1a8 | 1321 | |
4f25e72f | 1322 | TRACE("Told intermediate process to start initializing"); |
ea918412 | 1323 | |
4f25e72f CB |
1324 | /* Get pid of attached process from intermediate process. */ |
1325 | ret = lxc_read_nointr(ipc_sockets[0], &attached_pid, sizeof(attached_pid)); | |
1326 | if (ret != sizeof(attached_pid)) | |
1327 | goto close_mainloop; | |
ba2be1a8 | 1328 | |
4f25e72f | 1329 | TRACE("Received pid %d of attached process in parent pid namespace", attached_pid); |
ba2be1a8 | 1330 | |
4f25e72f CB |
1331 | /* Ignore SIGKILL (CTRL-C) and SIGQUIT (CTRL-\) - issue #313. */ |
1332 | if (options->stdin_fd == 0) { | |
1333 | signal(SIGINT, SIG_IGN); | |
1334 | signal(SIGQUIT, SIG_IGN); | |
1335 | } | |
ba2be1a8 | 1336 | |
4f25e72f CB |
1337 | /* Reap intermediate process. */ |
1338 | ret = wait_for_pid(pid); | |
1339 | if (ret < 0) | |
1340 | goto close_mainloop; | |
ba2be1a8 | 1341 | |
4f25e72f | 1342 | TRACE("Intermediate process %d exited", pid); |
ea918412 | 1343 | |
4f25e72f CB |
1344 | /* We will always have to reap the attached process now. */ |
1345 | to_cleanup_pid = attached_pid; | |
9c4693b8 | 1346 | |
4f25e72f CB |
1347 | /* Open LSM fd and send it to child. */ |
1348 | if ((options->namespaces & CLONE_NEWNS) && | |
ab919e5f | 1349 | (options->attach_flags & LXC_ATTACH_LSM) && ctx->lsm_label) { |
ad001fb6 | 1350 | __do_close int labelfd = -EBADF; |
4f25e72f | 1351 | bool on_exec; |
ea918412 | 1352 | |
4f25e72f CB |
1353 | ret = -1; |
1354 | on_exec = options->attach_flags & LXC_ATTACH_LSM_EXEC ? true : false; | |
ab919e5f CB |
1355 | labelfd = ctx->lsm_ops->process_label_fd_get(ctx->lsm_ops, |
1356 | attached_pid, on_exec); | |
4f25e72f CB |
1357 | if (labelfd < 0) |
1358 | goto close_mainloop; | |
9c4693b8 | 1359 | |
4f25e72f | 1360 | TRACE("Opened LSM label file descriptor %d", labelfd); |
ea918412 | 1361 | |
4f25e72f CB |
1362 | /* Send child fd of the LSM security module to write to. */ |
1363 | ret = lxc_abstract_unix_send_fds(ipc_sockets[0], &labelfd, 1, NULL, 0); | |
1364 | if (ret <= 0) { | |
1365 | if (ret < 0) | |
1366 | SYSERROR("Failed to send lsm label fd"); | |
4f25e72f CB |
1367 | goto close_mainloop; |
1368 | } | |
1369 | ||
4f25e72f | 1370 | TRACE("Sent LSM label file descriptor %d to child", labelfd); |
9c4693b8 | 1371 | } |
ea918412 | 1372 | |
4f25e72f CB |
1373 | if (conf->seccomp.seccomp) { |
1374 | ret = lxc_seccomp_recv_notifier_fd(&conf->seccomp, ipc_sockets[0]); | |
1375 | if (ret < 0) | |
1376 | goto close_mainloop; | |
9c4693b8 | 1377 | |
4f25e72f | 1378 | ret = lxc_seccomp_add_notifier(name, lxcpath, &conf->seccomp); |
d6d979bc | 1379 | if (ret < 0) |
4f25e72f | 1380 | goto close_mainloop; |
d6d979bc | 1381 | } |
9c4693b8 | 1382 | |
4f25e72f CB |
1383 | /* We're done, the child process should now execute whatever it |
1384 | * is that the user requested. The parent can now track it with | |
1385 | * waitpid() or similar. | |
1386 | */ | |
9c4693b8 | 1387 | |
4f25e72f | 1388 | *attached_process = attached_pid; |
a998454a | 1389 | |
4f25e72f CB |
1390 | /* Now shut down communication with child, we're done. */ |
1391 | shutdown(ipc_sockets[0], SHUT_RDWR); | |
1392 | close(ipc_sockets[0]); | |
1393 | ipc_sockets[0] = -1; | |
f157b056 | 1394 | |
4f25e72f CB |
1395 | ret_parent = 0; |
1396 | to_cleanup_pid = -1; | |
ea918412 | 1397 | |
4f25e72f CB |
1398 | if (options->attach_flags & LXC_ATTACH_TERMINAL) { |
1399 | ret = lxc_mainloop(&descr, -1); | |
1400 | if (ret < 0) { | |
1401 | ret_parent = -1; | |
1402 | to_cleanup_pid = attached_pid; | |
1403 | } | |
a998454a | 1404 | } |
ea918412 | 1405 | |
4f25e72f | 1406 | close_mainloop: |
9e84479f | 1407 | if (options->attach_flags & LXC_ATTACH_TERMINAL) |
4f25e72f | 1408 | lxc_mainloop_close(&descr); |
9c4693b8 | 1409 | |
4f25e72f CB |
1410 | on_error: |
1411 | if (ipc_sockets[0] >= 0) { | |
1412 | shutdown(ipc_sockets[0], SHUT_RDWR); | |
1413 | close(ipc_sockets[0]); | |
9c4693b8 | 1414 | } |
ea918412 | 1415 | |
4f25e72f CB |
1416 | if (to_cleanup_pid > 0) |
1417 | (void)wait_for_pid(to_cleanup_pid); | |
1418 | ||
1419 | if (options->attach_flags & LXC_ATTACH_TERMINAL) { | |
1420 | lxc_terminal_delete(&terminal); | |
1421 | lxc_terminal_conf_free(&terminal); | |
1422 | } | |
9c4693b8 | 1423 | |
dd53c8af | 1424 | put_attach_context(ctx); |
4f25e72f | 1425 | return ret_parent; |
9c4693b8 CS |
1426 | } |
1427 | ||
06346bb0 | 1428 | int lxc_attach_run_command(void *payload) |
9c4693b8 | 1429 | { |
06346bb0 CB |
1430 | int ret = -1; |
1431 | lxc_attach_command_t *cmd = payload; | |
9c4693b8 | 1432 | |
06346bb0 CB |
1433 | ret = execvp(cmd->program, cmd->argv); |
1434 | if (ret < 0) { | |
1435 | switch (errno) { | |
1436 | case ENOEXEC: | |
1437 | ret = 126; | |
cf0fd972 | 1438 | break; |
06346bb0 CB |
1439 | case ENOENT: |
1440 | ret = 127; | |
cf0fd972 | 1441 | break; |
06346bb0 CB |
1442 | } |
1443 | } | |
ea918412 | 1444 | |
c2af3a15 | 1445 | return log_error_errno(ret, errno, "Failed to exec \"%s\"", cmd->program); |
9c4693b8 CS |
1446 | } |
1447 | ||
1448 | int lxc_attach_run_shell(void* payload) | |
1449 | { | |
cd8f5663 | 1450 | __do_free char *buf = NULL; |
9c4693b8 | 1451 | uid_t uid; |
cb7aa5e8 DJ |
1452 | struct passwd pwent; |
1453 | struct passwd *pwentp = NULL; | |
9c4693b8 | 1454 | char *user_shell; |
cb7aa5e8 DJ |
1455 | size_t bufsize; |
1456 | int ret; | |
9c4693b8 | 1457 | |
8ce83369 | 1458 | /* Ignore payload parameter. */ |
9c4693b8 CS |
1459 | (void)payload; |
1460 | ||
1461 | uid = getuid(); | |
cb7aa5e8 DJ |
1462 | |
1463 | bufsize = sysconf(_SC_GETPW_R_SIZE_MAX); | |
1464 | if (bufsize == -1) | |
1465 | bufsize = 1024; | |
1466 | ||
1467 | buf = malloc(bufsize); | |
1468 | if (buf) { | |
1469 | ret = getpwuid_r(uid, &pwent, buf, bufsize, &pwentp); | |
1470 | if (!pwentp) { | |
1471 | if (ret == 0) | |
ea918412 | 1472 | WARN("Could not find matched password record"); |
cb7aa5e8 DJ |
1473 | |
1474 | WARN("Failed to get password record - %u", uid); | |
1475 | } | |
1476 | } | |
9c4693b8 | 1477 | |
8ce83369 CB |
1478 | /* This probably happens because of incompatible nss implementations in |
1479 | * host and container (remember, this code is still using the host's | |
1480 | * glibc but our mount namespace is in the container) we may try to get | |
1481 | * the information by spawning a [getent passwd uid] process and parsing | |
1482 | * the result. | |
9c4693b8 | 1483 | */ |
cb7aa5e8 | 1484 | if (!pwentp) |
9c4693b8 CS |
1485 | user_shell = lxc_attach_getpwshell(uid); |
1486 | else | |
cb7aa5e8 | 1487 | user_shell = pwent.pw_shell; |
ea918412 | 1488 | |
9c4693b8 | 1489 | if (user_shell) |
acf47e1b | 1490 | execlp(user_shell, user_shell, (char *)NULL); |
9c4693b8 | 1491 | |
8ce83369 CB |
1492 | /* Executed if either no passwd entry or execvp fails, we will fall back |
1493 | * on /bin/sh as a default shell. | |
9c4693b8 | 1494 | */ |
acf47e1b | 1495 | execlp("/bin/sh", "/bin/sh", (char *)NULL); |
ea918412 | 1496 | |
edeb1836 | 1497 | SYSERROR("Failed to execute shell"); |
cb7aa5e8 | 1498 | if (!pwentp) |
edeb1836 | 1499 | free(user_shell); |
ea918412 | 1500 | |
9c4693b8 CS |
1501 | return -1; |
1502 | } |