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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" |
6f4f1937 | 42 | #include "namespace.h" |
f40988c7 | 43 | #include "process_utils.h" |
59524108 | 44 | #include "syscall_wrappers.h" |
0ed9b1bc | 45 | #include "terminal.h" |
6f4f1937 | 46 | #include "utils.h" |
9c4693b8 CS |
47 | |
48 | #if HAVE_SYS_PERSONALITY_H | |
49 | #include <sys/personality.h> | |
50 | #endif | |
e0732705 | 51 | |
ac2cecc4 | 52 | lxc_log_define(attach, lxc); |
e0732705 | 53 | |
ef05d368 CB |
54 | /* Define default options if no options are supplied by the user. */ |
55 | static lxc_attach_options_t attach_static_default_options = LXC_ATTACH_OPTIONS_DEFAULT; | |
56 | ||
74a3920a | 57 | static struct lxc_proc_context_info *lxc_proc_get_context_info(pid_t pid) |
e0732705 | 58 | { |
cd8f5663 CB |
59 | __do_free char *line = NULL; |
60 | __do_fclose FILE *proc_file = NULL; | |
ffeeed8b | 61 | __do_free struct lxc_proc_context_info *info = NULL; |
6f4f1937 CB |
62 | int ret; |
63 | bool found; | |
604ca1c0 | 64 | char proc_fn[LXC_PROC_STATUS_LEN]; |
e0732705 | 65 | size_t line_bufsz = 0; |
e0732705 | 66 | |
8ce83369 | 67 | /* Read capabilities. */ |
604ca1c0 CB |
68 | ret = snprintf(proc_fn, LXC_PROC_STATUS_LEN, "/proc/%d/status", pid); |
69 | if (ret < 0 || ret >= LXC_PROC_STATUS_LEN) | |
cd8f5663 | 70 | return NULL; |
e0732705 | 71 | |
ffeeed8b CB |
72 | proc_file = fopen(proc_fn, "re"); |
73 | if (!proc_file) | |
74 | return log_error_errno(NULL, errno, "Failed to open %s", proc_fn); | |
e0732705 | 75 | |
8ce83369 | 76 | info = calloc(1, sizeof(*info)); |
cd8f5663 | 77 | if (!info) |
8ce83369 | 78 | return NULL; |
8ce83369 CB |
79 | |
80 | found = false; | |
ea918412 | 81 | |
e0732705 CS |
82 | while (getline(&line, &line_bufsz, proc_file) != -1) { |
83 | ret = sscanf(line, "CapBnd: %llx", &info->capability_mask); | |
8ce83369 CB |
84 | if (ret != EOF && ret == 1) { |
85 | found = true; | |
e0732705 CS |
86 | break; |
87 | } | |
88 | } | |
89 | ||
ffeeed8b CB |
90 | if (!found) |
91 | return log_error_errno(NULL, ENOENT, "Failed to read capability bounding set from %s", proc_fn); | |
e0732705 | 92 | |
fe4de9a6 | 93 | info->lsm_label = lsm_process_label_get(pid); |
877f3a04 | 94 | info->ns_inherited = 0; |
b87ee312 CB |
95 | for (int i = 0; i < LXC_NS_MAX; i++) |
96 | info->ns_fd[i] = -EBADF; | |
e0732705 | 97 | |
ffeeed8b | 98 | return move_ptr(info); |
e0732705 CS |
99 | } |
100 | ||
877f3a04 CB |
101 | static inline void lxc_proc_close_ns_fd(struct lxc_proc_context_info *ctx) |
102 | { | |
81102768 CB |
103 | for (int i = 0; i < LXC_NS_MAX; i++) |
104 | close_prot_errno_disarm(ctx->ns_fd[i]); | |
877f3a04 CB |
105 | } |
106 | ||
fe4de9a6 DE |
107 | static void lxc_proc_put_context_info(struct lxc_proc_context_info *ctx) |
108 | { | |
f10fad2f | 109 | free(ctx->lsm_label); |
08ea9270 CB |
110 | ctx->lsm_label = NULL; |
111 | ||
112 | if (ctx->container) { | |
2c4ea790 | 113 | lxc_container_put(ctx->container); |
08ea9270 CB |
114 | ctx->container = NULL; |
115 | } | |
116 | ||
877f3a04 | 117 | lxc_proc_close_ns_fd(ctx); |
fe4de9a6 DE |
118 | free(ctx); |
119 | } | |
120 | ||
299d1198 CB |
121 | /** |
122 | * in_same_namespace - Check whether two processes are in the same namespace. | |
123 | * @pid1 - PID of the first process. | |
124 | * @pid2 - PID of the second process. | |
125 | * @ns - Name of the namespace to check. Must correspond to one of the names | |
126 | * for the namespaces as shown in /proc/<pid/ns/ | |
127 | * | |
128 | * If the two processes are not in the same namespace returns an fd to the | |
129 | * namespace of the second process identified by @pid2. If the two processes are | |
130 | * in the same namespace returns -EINVAL, -1 if an error occurred. | |
131 | */ | |
132 | static int in_same_namespace(pid_t pid1, pid_t pid2, const char *ns) | |
133 | { | |
644e7393 | 134 | __do_close int ns_fd1 = -EBADF, ns_fd2 = -EBADF; |
3cc629fe | 135 | int ret = -1; |
299d1198 CB |
136 | struct stat ns_st1, ns_st2; |
137 | ||
138 | ns_fd1 = lxc_preserve_ns(pid1, ns); | |
134284c3 CB |
139 | if (ns_fd1 < 0) { |
140 | /* The kernel does not support this namespace. This is not an | |
141 | * error. | |
142 | */ | |
143 | if (errno == ENOENT) | |
144 | return -EINVAL; | |
145 | ||
3cc629fe | 146 | return -1; |
134284c3 | 147 | } |
299d1198 CB |
148 | |
149 | ns_fd2 = lxc_preserve_ns(pid2, ns); | |
21d0acc2 | 150 | if (ns_fd2 < 0) |
3cc629fe | 151 | return -1; |
299d1198 CB |
152 | |
153 | ret = fstat(ns_fd1, &ns_st1); | |
21d0acc2 | 154 | if (ret < 0) |
3cc629fe | 155 | return -1; |
299d1198 CB |
156 | |
157 | ret = fstat(ns_fd2, &ns_st2); | |
21d0acc2 | 158 | if (ret < 0) |
3cc629fe | 159 | return -1; |
299d1198 CB |
160 | |
161 | /* processes are in the same namespace */ | |
3cc629fe CB |
162 | if ((ns_st1.st_dev == ns_st2.st_dev) && (ns_st1.st_ino == ns_st2.st_ino)) |
163 | return -EINVAL; | |
299d1198 CB |
164 | |
165 | /* processes are in different namespaces */ | |
3cc629fe | 166 | return move_fd(ns_fd2); |
299d1198 CB |
167 | } |
168 | ||
877f3a04 | 169 | static int lxc_attach_to_ns(pid_t pid, struct lxc_proc_context_info *ctx) |
99d50954 | 170 | { |
ffeeed8b CB |
171 | for (int i = 0; i < LXC_NS_MAX; i++) { |
172 | int ret; | |
99d50954 | 173 | |
877f3a04 | 174 | if (ctx->ns_fd[i] < 0) |
26818618 CB |
175 | continue; |
176 | ||
21d0acc2 | 177 | ret = setns(ctx->ns_fd[i], ns_info[i].clone_flag); |
ffeeed8b CB |
178 | if (ret < 0) |
179 | return log_error_errno(-1, | |
180 | errno, "Failed to attach to %s namespace of %d", | |
181 | ns_info[i].proc_name, pid); | |
99d50954 | 182 | |
299d1198 | 183 | DEBUG("Attached to %s namespace of %d", ns_info[i].proc_name, pid); |
99d50954 CS |
184 | } |
185 | ||
186 | return 0; | |
187 | } | |
188 | ||
e4103cf6 | 189 | int lxc_attach_remount_sys_proc(void) |
7a0b0b56 CS |
190 | { |
191 | int ret; | |
192 | ||
193 | ret = unshare(CLONE_NEWNS); | |
ffeeed8b CB |
194 | if (ret < 0) |
195 | return log_error_errno(-1, errno, "Failed to unshare mount namespace"); | |
7a0b0b56 | 196 | |
2c6f3fc9 | 197 | if (detect_shared_rootfs()) { |
6f4f1937 | 198 | if (mount(NULL, "/", NULL, MS_SLAVE | MS_REC, NULL)) { |
ea918412 | 199 | SYSERROR("Failed to make / rslave"); |
2c6f3fc9 SH |
200 | ERROR("Continuing..."); |
201 | } | |
202 | } | |
203 | ||
8ce83369 | 204 | /* Assume /proc is always mounted, so remount it. */ |
7a0b0b56 | 205 | ret = umount2("/proc", MNT_DETACH); |
ffeeed8b CB |
206 | if (ret < 0) |
207 | return log_error_errno(-1, errno, "Failed to unmount /proc"); | |
7a0b0b56 CS |
208 | |
209 | ret = mount("none", "/proc", "proc", 0, NULL); | |
ffeeed8b CB |
210 | if (ret < 0) |
211 | return log_error_errno(-1, errno, "Failed to remount /proc"); | |
7a0b0b56 | 212 | |
ffeeed8b CB |
213 | /* |
214 | * Try to umount /sys. If it's not a mount point, we'll get EINVAL, then | |
8ce83369 | 215 | * we ignore it because it may not have been mounted in the first place. |
7a0b0b56 CS |
216 | */ |
217 | ret = umount2("/sys", MNT_DETACH); | |
ffeeed8b CB |
218 | if (ret < 0 && errno != EINVAL) |
219 | return log_error_errno(-1, errno, "Failed to unmount /sys"); | |
220 | ||
221 | /* Remount it. */ | |
222 | if (ret == 0 && mount("none", "/sys", "sysfs", 0, NULL)) | |
223 | return log_error_errno(-1, errno, "Failed to remount /sys"); | |
7a0b0b56 CS |
224 | |
225 | return 0; | |
226 | } | |
227 | ||
74a3920a | 228 | static int lxc_attach_drop_privs(struct lxc_proc_context_info *ctx) |
e0732705 | 229 | { |
ffeeed8b | 230 | int last_cap; |
e0732705 | 231 | |
6f4f1937 | 232 | last_cap = lxc_caps_last_cap(); |
ffeeed8b | 233 | for (int cap = 0; cap <= last_cap; cap++) { |
e0732705 CS |
234 | if (ctx->capability_mask & (1LL << cap)) |
235 | continue; | |
236 | ||
b81689a1 | 237 | if (prctl(PR_CAPBSET_DROP, prctl_arg(cap), prctl_arg(0), |
ffeeed8b CB |
238 | prctl_arg(0), prctl_arg(0))) |
239 | return log_error_errno(-1, errno, "Failed to drop capability %d", cap); | |
ea918412 | 240 | |
94ac256f | 241 | TRACE("Dropped capability %d", cap); |
e0732705 CS |
242 | } |
243 | ||
244 | return 0; | |
245 | } | |
905022f7 | 246 | |
7385273f | 247 | static int lxc_attach_set_environment(struct lxc_proc_context_info *init_ctx, |
248 | enum lxc_attach_env_policy_t policy, | |
6f4f1937 | 249 | char **extra_env, char **extra_keep) |
b3a39ba6 | 250 | { |
3d55242a | 251 | int ret; |
7385273f | 252 | struct lxc_list *iterator; |
253 | ||
799f96fd | 254 | if (policy == LXC_ATTACH_CLEAR_ENV) { |
3d5e9f48 | 255 | int path_kept = 0; |
6f4f1937 | 256 | char **extra_keep_store = NULL; |
3d5e9f48 CS |
257 | |
258 | if (extra_keep) { | |
259 | size_t count, i; | |
260 | ||
3d55242a CB |
261 | for (count = 0; extra_keep[count]; count++) |
262 | ; | |
3d5e9f48 CS |
263 | |
264 | extra_keep_store = calloc(count, sizeof(char *)); | |
3d55242a | 265 | if (!extra_keep_store) |
3d5e9f48 | 266 | return -1; |
3d55242a | 267 | |
3d5e9f48 CS |
268 | for (i = 0; i < count; i++) { |
269 | char *v = getenv(extra_keep[i]); | |
270 | if (v) { | |
271 | extra_keep_store[i] = strdup(v); | |
272 | if (!extra_keep_store[i]) { | |
3d5e9f48 CS |
273 | while (i > 0) |
274 | free(extra_keep_store[--i]); | |
ea918412 | 275 | |
3d5e9f48 CS |
276 | free(extra_keep_store); |
277 | return -1; | |
278 | } | |
3d55242a | 279 | |
3d5e9f48 CS |
280 | if (strcmp(extra_keep[i], "PATH") == 0) |
281 | path_kept = 1; | |
282 | } | |
3d5e9f48 CS |
283 | } |
284 | } | |
285 | ||
799f96fd | 286 | if (clearenv()) { |
a9cab7e3 | 287 | if (extra_keep_store) { |
3d55242a CB |
288 | char **p; |
289 | ||
a9cab7e3 CS |
290 | for (p = extra_keep_store; *p; p++) |
291 | free(*p); | |
3d55242a | 292 | |
a9cab7e3 CS |
293 | free(extra_keep_store); |
294 | } | |
3d55242a | 295 | |
ffeeed8b | 296 | return log_error(-1, "Failed to clear environment"); |
3d5e9f48 CS |
297 | } |
298 | ||
299 | if (extra_keep_store) { | |
300 | size_t i; | |
6f4f1937 | 301 | |
3d5e9f48 | 302 | for (i = 0; extra_keep[i]; i++) { |
acd4922e | 303 | if (extra_keep_store[i]) { |
3d55242a CB |
304 | ret = setenv(extra_keep[i], extra_keep_store[i], 1); |
305 | if (ret < 0) | |
a24c5678 | 306 | SYSWARN("Failed to set environment variable"); |
acd4922e | 307 | } |
ea918412 | 308 | |
3d5e9f48 CS |
309 | free(extra_keep_store[i]); |
310 | } | |
ea918412 | 311 | |
3d5e9f48 CS |
312 | free(extra_keep_store); |
313 | } | |
314 | ||
8ce83369 CB |
315 | /* Always set a default path; shells and execlp tend to be fine |
316 | * without it, but there is a disturbing number of C programs | |
317 | * out there that just assume that getenv("PATH") is never NULL | |
318 | * and then die a painful segfault death. | |
319 | */ | |
3d55242a CB |
320 | if (!path_kept) { |
321 | ret = setenv("PATH", "/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin", 1); | |
322 | if (ret < 0) | |
a24c5678 | 323 | SYSWARN("Failed to set environment variable"); |
3d55242a | 324 | } |
b3a39ba6 DW |
325 | } |
326 | ||
3d55242a | 327 | ret = putenv("container=lxc"); |
ffeeed8b | 328 | if (ret < 0) |
818a57fc | 329 | return log_warn(-1, "Failed to set environment variable"); |
b3a39ba6 | 330 | |
7385273f | 331 | /* Set container environment variables.*/ |
332 | if (init_ctx && init_ctx->container && init_ctx->container->lxc_conf) { | |
333 | lxc_list_for_each(iterator, &init_ctx->container->lxc_conf->environment) { | |
3d55242a CB |
334 | char *env_tmp; |
335 | ||
336 | env_tmp = strdup((char *)iterator->elem); | |
337 | if (!env_tmp) | |
7385273f | 338 | return -1; |
7385273f | 339 | |
3d55242a | 340 | ret = putenv(env_tmp); |
ffeeed8b CB |
341 | if (ret < 0) |
342 | return log_error_errno(-1, errno, "Failed to set environment variable: %s", (char *)iterator->elem); | |
7385273f | 343 | } |
344 | } | |
345 | ||
8ce83369 | 346 | /* Set extra environment variables. */ |
3d5e9f48 CS |
347 | if (extra_env) { |
348 | for (; *extra_env; extra_env++) { | |
3d55242a | 349 | char *p; |
ea918412 | 350 | |
8ce83369 CB |
351 | /* We just assume the user knows what they are doing, so |
352 | * we don't do any checks. | |
353 | */ | |
3d55242a CB |
354 | p = strdup(*extra_env); |
355 | if (!p) | |
3d5e9f48 | 356 | return -1; |
3d55242a CB |
357 | |
358 | ret = putenv(p); | |
359 | if (ret < 0) | |
a24c5678 | 360 | SYSWARN("Failed to set environment variable"); |
3d5e9f48 CS |
361 | } |
362 | } | |
363 | ||
b3a39ba6 DW |
364 | return 0; |
365 | } | |
366 | ||
74a3920a | 367 | static char *lxc_attach_getpwshell(uid_t uid) |
905022f7 | 368 | { |
1b9c9f5b | 369 | __do_free char *line = NULL, *result = NULL; |
cd8f5663 | 370 | __do_fclose FILE *pipe_f = NULL; |
6f4f1937 | 371 | int fd, ret; |
905022f7 CS |
372 | pid_t pid; |
373 | int pipes[2]; | |
3fa23ac3 CB |
374 | bool found = false; |
375 | size_t line_bufsz = 0; | |
905022f7 | 376 | |
8ce83369 CB |
377 | /* We need to fork off a process that runs the getent program, and we |
378 | * need to capture its output, so we use a pipe for that purpose. | |
905022f7 | 379 | */ |
3fa23ac3 | 380 | ret = pipe2(pipes, O_CLOEXEC); |
905022f7 CS |
381 | if (ret < 0) |
382 | return NULL; | |
383 | ||
384 | pid = fork(); | |
385 | if (pid < 0) { | |
386 | close(pipes[0]); | |
387 | close(pipes[1]); | |
388 | return NULL; | |
389 | } | |
390 | ||
3fa23ac3 | 391 | if (!pid) { |
905022f7 CS |
392 | char uid_buf[32]; |
393 | char *arguments[] = { | |
394 | "getent", | |
395 | "passwd", | |
396 | uid_buf, | |
397 | NULL | |
398 | }; | |
399 | ||
400 | close(pipes[0]); | |
401 | ||
8ce83369 | 402 | /* We want to capture stdout. */ |
3fa23ac3 | 403 | ret = dup2(pipes[1], STDOUT_FILENO); |
905022f7 | 404 | close(pipes[1]); |
3fa23ac3 | 405 | if (ret < 0) |
ea918412 | 406 | _exit(EXIT_FAILURE); |
905022f7 | 407 | |
8ce83369 CB |
408 | /* Get rid of stdin/stderr, so we try to associate it with |
409 | * /dev/null. | |
905022f7 | 410 | */ |
3fa23ac3 | 411 | fd = open_devnull(); |
905022f7 | 412 | if (fd < 0) { |
3fa23ac3 CB |
413 | close(STDIN_FILENO); |
414 | close(STDERR_FILENO); | |
905022f7 | 415 | } else { |
3fa23ac3 | 416 | (void)dup3(fd, STDIN_FILENO, O_CLOEXEC); |
59f0e209 | 417 | (void)dup3(fd, STDERR_FILENO, O_CLOEXEC); |
905022f7 CS |
418 | close(fd); |
419 | } | |
420 | ||
8ce83369 | 421 | /* Finish argument list. */ |
3fa23ac3 CB |
422 | ret = snprintf(uid_buf, sizeof(uid_buf), "%ld", (long)uid); |
423 | if (ret <= 0 || ret >= sizeof(uid_buf)) | |
ea918412 | 424 | _exit(EXIT_FAILURE); |
905022f7 | 425 | |
8ce83369 | 426 | /* Try to run getent program. */ |
3fa23ac3 | 427 | (void)execvp("getent", arguments); |
ea918412 | 428 | _exit(EXIT_FAILURE); |
905022f7 | 429 | } |
3fa23ac3 CB |
430 | |
431 | close(pipes[1]); | |
432 | ||
4110345b | 433 | pipe_f = fdopen(pipes[0], "re"); |
cf4026f1 CB |
434 | if (!pipe_f) { |
435 | close(pipes[0]); | |
436 | goto reap_child; | |
437 | } | |
438 | /* Transfer ownership of pipes[0] to pipe_f. */ | |
439 | move_fd(pipes[0]); | |
440 | ||
3fa23ac3 CB |
441 | while (getline(&line, &line_bufsz, pipe_f) != -1) { |
442 | int i; | |
443 | long value; | |
444 | char *token; | |
445 | char *endptr = NULL, *saveptr = NULL; | |
446 | ||
447 | /* If we already found something, just continue to read | |
448 | * until the pipe doesn't deliver any more data, but | |
449 | * don't modify the existing data structure. | |
450 | */ | |
451 | if (found) | |
452 | continue; | |
453 | ||
18d4ffde | 454 | if (!line) |
455 | continue; | |
456 | ||
3fa23ac3 CB |
457 | /* Trim line on the right hand side. */ |
458 | for (i = strlen(line); i > 0 && (line[i - 1] == '\n' || line[i - 1] == '\r'); --i) | |
459 | line[i - 1] = '\0'; | |
460 | ||
461 | /* Split into tokens: first: user name. */ | |
462 | token = strtok_r(line, ":", &saveptr); | |
463 | if (!token) | |
464 | continue; | |
465 | ||
466 | /* next: dummy password field */ | |
467 | token = strtok_r(NULL, ":", &saveptr); | |
468 | if (!token) | |
469 | continue; | |
470 | ||
471 | /* next: user id */ | |
472 | token = strtok_r(NULL, ":", &saveptr); | |
473 | value = token ? strtol(token, &endptr, 10) : 0; | |
474 | if (!token || !endptr || *endptr || value == LONG_MIN || | |
ea918412 | 475 | value == LONG_MAX) |
3fa23ac3 CB |
476 | continue; |
477 | ||
478 | /* dummy sanity check: user id matches */ | |
479 | if ((uid_t)value != uid) | |
480 | continue; | |
481 | ||
482 | /* skip fields: gid, gecos, dir, go to next field 'shell' */ | |
483 | for (i = 0; i < 4; i++) { | |
484 | token = strtok_r(NULL, ":", &saveptr); | |
485 | if (!token) | |
486 | continue; | |
487 | } | |
ea918412 | 488 | |
3fa23ac3 CB |
489 | if (!token) |
490 | continue; | |
ea918412 | 491 | |
1b9c9f5b | 492 | free_disarm(result); |
3fa23ac3 CB |
493 | result = strdup(token); |
494 | ||
495 | /* Sanity check that there are no fields after that. */ | |
496 | token = strtok_r(NULL, ":", &saveptr); | |
497 | if (token) | |
498 | continue; | |
499 | ||
500 | found = true; | |
501 | } | |
ea918412 | 502 | |
cf4026f1 | 503 | reap_child: |
3fa23ac3 | 504 | ret = wait_for_pid(pid); |
1b9c9f5b | 505 | if (ret < 0) |
3fa23ac3 | 506 | return NULL; |
3fa23ac3 | 507 | |
1b9c9f5b | 508 | if (!found) |
3fa23ac3 | 509 | return NULL; |
3fa23ac3 | 510 | |
1b9c9f5b | 511 | return move_ptr(result); |
905022f7 | 512 | } |
cb3e61fa | 513 | |
6f4f1937 | 514 | static void lxc_attach_get_init_uidgid(uid_t *init_uid, gid_t *init_gid) |
cb3e61fa | 515 | { |
cd8f5663 CB |
516 | __do_free char *line = NULL; |
517 | __do_fclose FILE *proc_file = NULL; | |
604ca1c0 | 518 | char proc_fn[LXC_PROC_STATUS_LEN]; |
8ce83369 | 519 | int ret; |
cb3e61fa | 520 | size_t line_bufsz = 0; |
cb3e61fa | 521 | long value = -1; |
a5d657d3 CB |
522 | uid_t uid = LXC_INVALID_UID; |
523 | gid_t gid = LXC_INVALID_GID; | |
cb3e61fa | 524 | |
604ca1c0 CB |
525 | ret = snprintf(proc_fn, LXC_PROC_STATUS_LEN, "/proc/%d/status", 1); |
526 | if (ret < 0 || ret >= LXC_PROC_STATUS_LEN) | |
7fb45c93 | 527 | return; |
cb3e61fa | 528 | |
4110345b | 529 | proc_file = fopen(proc_fn, "re"); |
cb3e61fa CS |
530 | if (!proc_file) |
531 | return; | |
532 | ||
533 | while (getline(&line, &line_bufsz, proc_file) != -1) { | |
8ce83369 CB |
534 | /* Format is: real, effective, saved set user, fs we only care |
535 | * about real uid. | |
cb3e61fa CS |
536 | */ |
537 | ret = sscanf(line, "Uid: %ld", &value); | |
8ce83369 | 538 | if (ret != EOF && ret == 1) { |
6f4f1937 | 539 | uid = (uid_t)value; |
cb3e61fa CS |
540 | } else { |
541 | ret = sscanf(line, "Gid: %ld", &value); | |
8ce83369 | 542 | if (ret != EOF && ret == 1) |
6f4f1937 | 543 | gid = (gid_t)value; |
cb3e61fa | 544 | } |
ea918412 | 545 | |
a5d657d3 | 546 | if (uid != LXC_INVALID_UID && gid != LXC_INVALID_GID) |
cb3e61fa CS |
547 | break; |
548 | } | |
549 | ||
8ce83369 | 550 | /* Only override arguments if we found something. */ |
a5d657d3 | 551 | if (uid != LXC_INVALID_UID) |
cb3e61fa | 552 | *init_uid = uid; |
ea918412 | 553 | |
a5d657d3 | 554 | if (gid != LXC_INVALID_GID) |
cb3e61fa CS |
555 | *init_gid = gid; |
556 | ||
557 | /* TODO: we should also parse supplementary groups and use | |
8ce83369 CB |
558 | * setgroups() to set them. |
559 | */ | |
cb3e61fa | 560 | } |
9c4693b8 | 561 | |
d4db3d14 | 562 | static bool fetch_seccomp(struct lxc_container *c, lxc_attach_options_t *options) |
2c4ea790 | 563 | { |
cd8f5663 | 564 | __do_free char *path = NULL; |
d4db3d14 CB |
565 | int ret; |
566 | bool bret; | |
2eef2bda | 567 | |
6f4f1937 CB |
568 | if (!(options->namespaces & CLONE_NEWNS) || |
569 | !(options->attach_flags & LXC_ATTACH_LSM)) { | |
cca66e06 | 570 | free_disarm(c->lxc_conf->seccomp.seccomp); |
2c4ea790 | 571 | return true; |
bd4307f0 | 572 | } |
bd7b4e28 | 573 | |
2e812c16 | 574 | /* Remove current setting. */ |
d4db3d14 | 575 | if (!c->set_config_item(c, "lxc.seccomp.profile", "") && |
ea918412 | 576 | !c->set_config_item(c, "lxc.seccomp", "")) |
2c4ea790 | 577 | return false; |
bd7b4e28 | 578 | |
8ce83369 | 579 | /* Fetch the current profile path over the cmd interface. */ |
0b427da0 | 580 | path = c->get_running_config_item(c, "lxc.seccomp.profile"); |
bd7b4e28 | 581 | if (!path) { |
d4db3d14 | 582 | INFO("Failed to retrieve lxc.seccomp.profile"); |
ea918412 | 583 | |
0b427da0 | 584 | path = c->get_running_config_item(c, "lxc.seccomp"); |
cca66e06 CB |
585 | if (!path) |
586 | return log_info(true, "Failed to retrieve lxc.seccomp"); | |
bd7b4e28 SG |
587 | } |
588 | ||
8ce83369 | 589 | /* Copy the value into the new lxc_conf. */ |
d4db3d14 | 590 | bret = c->set_config_item(c, "lxc.seccomp.profile", path); |
d4db3d14 CB |
591 | if (!bret) |
592 | return false; | |
bd7b4e28 | 593 | |
8ce83369 | 594 | /* Attempt to parse the resulting config. */ |
d4db3d14 | 595 | ret = lxc_read_seccomp_config(c->lxc_conf); |
cca66e06 CB |
596 | if (ret < 0) |
597 | return log_error(false, "Failed to retrieve seccomp policy"); | |
2c4ea790 | 598 | |
cca66e06 | 599 | return log_info(true, "Retrieved seccomp policy"); |
2e812c16 CB |
600 | } |
601 | ||
6f4f1937 | 602 | static bool no_new_privs(struct lxc_container *c, lxc_attach_options_t *options) |
2e812c16 | 603 | { |
cd8f5663 | 604 | __do_free char *val = NULL; |
2e812c16 | 605 | |
2e812c16 | 606 | /* Remove current setting. */ |
02d3b72b CB |
607 | if (!c->set_config_item(c, "lxc.no_new_privs", "")) |
608 | return log_info(false, "Failed to unset lxc.no_new_privs"); | |
2e812c16 CB |
609 | |
610 | /* Retrieve currently active setting. */ | |
611 | val = c->get_running_config_item(c, "lxc.no_new_privs"); | |
02d3b72b CB |
612 | if (!val) |
613 | return log_info(false, "Failed to retrieve lxc.no_new_privs"); | |
2e812c16 CB |
614 | |
615 | /* Set currently active setting. */ | |
cd8f5663 | 616 | return c->set_config_item(c, "lxc.no_new_privs", val); |
2c4ea790 SH |
617 | } |
618 | ||
9b8e3c96 SH |
619 | static signed long get_personality(const char *name, const char *lxcpath) |
620 | { | |
7c737378 | 621 | __do_free char *p = NULL; |
9b8e3c96 | 622 | |
6f4f1937 | 623 | p = lxc_cmd_get_config_item(name, "lxc.arch", lxcpath); |
9b8e3c96 SH |
624 | if (!p) |
625 | return -1; | |
6f4f1937 | 626 | |
cd8f5663 | 627 | return lxc_config_parse_arch(p); |
9b8e3c96 SH |
628 | } |
629 | ||
a998454a CB |
630 | struct attach_clone_payload { |
631 | int ipc_socket; | |
cecf3e83 | 632 | int terminal_pts_fd; |
a998454a CB |
633 | lxc_attach_options_t *options; |
634 | struct lxc_proc_context_info *init_ctx; | |
635 | lxc_attach_exec_t exec_function; | |
636 | void *exec_payload; | |
637 | }; | |
638 | ||
ba2be1a8 CB |
639 | static void lxc_put_attach_clone_payload(struct attach_clone_payload *p) |
640 | { | |
81102768 | 641 | close_prot_errno_disarm(p->ipc_socket); |
cecf3e83 | 642 | close_prot_errno_disarm(p->terminal_pts_fd); |
b21da190 | 643 | if (p->init_ctx) { |
ba2be1a8 | 644 | lxc_proc_put_context_info(p->init_ctx); |
b21da190 CB |
645 | p->init_ctx = NULL; |
646 | } | |
ba2be1a8 CB |
647 | } |
648 | ||
a998454a CB |
649 | static int attach_child_main(struct attach_clone_payload *payload) |
650 | { | |
427a8067 | 651 | int lsm_fd, ret; |
a998454a CB |
652 | uid_t new_uid; |
653 | gid_t new_gid; | |
936efc72 CB |
654 | uid_t ns_root_uid = 0; |
655 | gid_t ns_root_gid = 0; | |
a998454a CB |
656 | lxc_attach_options_t* options = payload->options; |
657 | struct lxc_proc_context_info* init_ctx = payload->init_ctx; | |
57de839f CB |
658 | bool needs_lsm = (options->namespaces & CLONE_NEWNS) && |
659 | (options->attach_flags & LXC_ATTACH_LSM) && | |
660 | init_ctx->lsm_label; | |
a998454a CB |
661 | |
662 | /* A description of the purpose of this functionality is provided in the | |
663 | * lxc-attach(1) manual page. We have to remount here and not in the | |
664 | * parent process, otherwise /proc may not properly reflect the new pid | |
665 | * namespace. | |
666 | */ | |
667 | if (!(options->namespaces & CLONE_NEWNS) && | |
668 | (options->attach_flags & LXC_ATTACH_REMOUNT_PROC_SYS)) { | |
669 | ret = lxc_attach_remount_sys_proc(); | |
b75c344c CB |
670 | if (ret < 0) |
671 | goto on_error; | |
ea918412 | 672 | |
b75c344c | 673 | TRACE("Remounted \"/proc\" and \"/sys\""); |
a998454a CB |
674 | } |
675 | ||
b75c344c | 676 | /* Now perform additional attachments. */ |
a998454a | 677 | #if HAVE_SYS_PERSONALITY_H |
a998454a | 678 | if (options->attach_flags & LXC_ATTACH_SET_PERSONALITY) { |
b75c344c CB |
679 | long new_personality; |
680 | ||
681 | if (options->personality < 0) | |
682 | new_personality = init_ctx->personality; | |
683 | else | |
684 | new_personality = options->personality; | |
ea918412 | 685 | |
a998454a | 686 | ret = personality(new_personality); |
b75c344c CB |
687 | if (ret < 0) |
688 | goto on_error; | |
ea918412 | 689 | |
b75c344c | 690 | TRACE("Set new personality"); |
a998454a CB |
691 | } |
692 | #endif | |
693 | ||
694 | if (options->attach_flags & LXC_ATTACH_DROP_CAPABILITIES) { | |
695 | ret = lxc_attach_drop_privs(init_ctx); | |
b75c344c CB |
696 | if (ret < 0) |
697 | goto on_error; | |
ea918412 | 698 | |
b75c344c | 699 | TRACE("Dropped capabilities"); |
a998454a CB |
700 | } |
701 | ||
702 | /* Always set the environment (specify (LXC_ATTACH_KEEP_ENV, NULL, NULL) | |
703 | * if you want this to be a no-op). | |
704 | */ | |
7385273f | 705 | ret = lxc_attach_set_environment(init_ctx, |
706 | options->env_policy, | |
a998454a CB |
707 | options->extra_env_vars, |
708 | options->extra_keep_env); | |
b75c344c CB |
709 | if (ret < 0) |
710 | goto on_error; | |
ea918412 | 711 | |
b75c344c | 712 | TRACE("Set up environment"); |
a998454a | 713 | |
57de839f CB |
714 | /* This remark only affects fully unprivileged containers: |
715 | * Receive fd for LSM security module before we set{g,u}id(). The reason | |
716 | * is that on set{g,u}id() the kernel will a) make us undumpable and b) | |
717 | * we will change our effective uid. This means our effective uid will | |
718 | * be different from the effective uid of the process that created us | |
719 | * which means that this processs no longer has capabilities in our | |
720 | * namespace including CAP_SYS_PTRACE. This means we will not be able to | |
721 | * read and /proc/<pid> files for the process anymore when /proc is | |
722 | * mounted with hidepid={1,2}. So let's get the lsm label fd before the | |
723 | * set{g,u}id(). | |
724 | */ | |
725 | if (needs_lsm) { | |
b75c344c | 726 | ret = lxc_abstract_unix_recv_fds(payload->ipc_socket, &lsm_fd, 1, NULL, 0); |
9044b79e | 727 | if (ret <= 0) { |
728 | if (ret < 0) | |
729 | SYSERROR("Failed to receive lsm label fd"); | |
730 | ||
b75c344c | 731 | goto on_error; |
9044b79e | 732 | } |
733 | ||
57de839f CB |
734 | TRACE("Received LSM label file descriptor %d from parent", lsm_fd); |
735 | } | |
736 | ||
08ea9270 | 737 | if (options->stdin_fd > 0 && isatty(options->stdin_fd)) { |
cd0a2b2f | 738 | ret = lxc_make_controlling_terminal(options->stdin_fd); |
08ea9270 CB |
739 | if (ret < 0) |
740 | goto on_error; | |
741 | } | |
742 | ||
b58214ac CB |
743 | if (!lxc_setgroups(0, NULL) && errno != EPERM) |
744 | goto on_error; | |
745 | ||
936efc72 CB |
746 | if (options->namespaces & CLONE_NEWUSER) { |
747 | /* Check whether nsuid 0 has a mapping. */ | |
748 | ns_root_uid = get_ns_uid(0); | |
ea918412 | 749 | |
936efc72 CB |
750 | /* Check whether nsgid 0 has a mapping. */ |
751 | ns_root_gid = get_ns_gid(0); | |
a998454a | 752 | |
936efc72 CB |
753 | /* If there's no mapping for nsuid 0 try to retrieve the nsuid |
754 | * init was started with. | |
755 | */ | |
756 | if (ns_root_uid == LXC_INVALID_UID) | |
757 | lxc_attach_get_init_uidgid(&ns_root_uid, &ns_root_gid); | |
ea918412 | 758 | |
936efc72 CB |
759 | if (ns_root_uid == LXC_INVALID_UID) |
760 | goto on_error; | |
a998454a | 761 | |
464c4611 | 762 | if (!lxc_switch_uid_gid(ns_root_uid, ns_root_gid)) |
b75c344c | 763 | goto on_error; |
a998454a CB |
764 | } |
765 | ||
936efc72 CB |
766 | /* Set {u,g}id. */ |
767 | if (options->uid != LXC_INVALID_UID) | |
768 | new_uid = options->uid; | |
769 | else | |
770 | new_uid = ns_root_uid; | |
771 | ||
772 | if (options->gid != LXC_INVALID_GID) | |
773 | new_gid = options->gid; | |
774 | else | |
775 | new_gid = ns_root_gid; | |
776 | ||
a998454a CB |
777 | if ((init_ctx->container && init_ctx->container->lxc_conf && |
778 | init_ctx->container->lxc_conf->no_new_privs) || | |
779 | (options->attach_flags & LXC_ATTACH_NO_NEW_PRIVS)) { | |
b81689a1 CB |
780 | ret = prctl(PR_SET_NO_NEW_PRIVS, prctl_arg(1), prctl_arg(0), |
781 | prctl_arg(0), prctl_arg(0)); | |
b75c344c CB |
782 | if (ret < 0) |
783 | goto on_error; | |
ea918412 | 784 | |
b75c344c | 785 | TRACE("Set PR_SET_NO_NEW_PRIVS"); |
a998454a CB |
786 | } |
787 | ||
57de839f | 788 | if (needs_lsm) { |
d3ba7c98 | 789 | bool on_exec; |
a998454a CB |
790 | |
791 | /* Change into our new LSM profile. */ | |
d3ba7c98 | 792 | on_exec = options->attach_flags & LXC_ATTACH_LSM_EXEC ? true : false; |
ea918412 | 793 | |
d3ba7c98 | 794 | ret = lsm_process_label_set_at(lsm_fd, init_ctx->lsm_label, on_exec); |
57de839f | 795 | close(lsm_fd); |
b75c344c CB |
796 | if (ret < 0) |
797 | goto on_error; | |
ea918412 | 798 | |
d3ba7c98 | 799 | TRACE("Set %s LSM label to \"%s\"", lsm_name(), init_ctx->lsm_label); |
a998454a CB |
800 | } |
801 | ||
802 | if (init_ctx->container && init_ctx->container->lxc_conf && | |
c3e3c21a | 803 | init_ctx->container->lxc_conf->seccomp.seccomp) { |
cdb2a47f CB |
804 | struct lxc_conf *conf = init_ctx->container->lxc_conf; |
805 | ||
806 | ret = lxc_seccomp_load(conf); | |
b75c344c CB |
807 | if (ret < 0) |
808 | goto on_error; | |
ea918412 | 809 | |
b75c344c | 810 | TRACE("Loaded seccomp profile"); |
cdb2a47f | 811 | |
c3e3c21a CB |
812 | ret = lxc_seccomp_send_notifier_fd(&conf->seccomp, payload->ipc_socket); |
813 | if (ret < 0) | |
814 | goto on_error; | |
a998454a | 815 | } |
ea918412 | 816 | |
b75c344c | 817 | close(payload->ipc_socket); |
ba2be1a8 CB |
818 | payload->ipc_socket = -EBADF; |
819 | lxc_proc_put_context_info(init_ctx); | |
d35b372a | 820 | payload->init_ctx = NULL; |
a998454a CB |
821 | |
822 | /* The following is done after the communication socket is shut down. | |
823 | * That way, all errors that might (though unlikely) occur up until this | |
824 | * point will have their messages printed to the original stderr (if | |
825 | * logging is so configured) and not the fd the user supplied, if any. | |
826 | */ | |
827 | ||
828 | /* Fd handling for stdin, stdout and stderr; ignore errors here, user | |
829 | * may want to make sure the fds are closed, for example. | |
830 | */ | |
08ea9270 | 831 | if (options->stdin_fd >= 0 && options->stdin_fd != STDIN_FILENO) |
00c72a93 | 832 | (void)dup2(options->stdin_fd, STDIN_FILENO); |
08ea9270 CB |
833 | |
834 | if (options->stdout_fd >= 0 && options->stdout_fd != STDOUT_FILENO) | |
00c72a93 | 835 | (void)dup2(options->stdout_fd, STDOUT_FILENO); |
08ea9270 CB |
836 | |
837 | if (options->stderr_fd >= 0 && options->stderr_fd != STDERR_FILENO) | |
00c72a93 | 838 | (void)dup2(options->stderr_fd, STDERR_FILENO); |
a998454a CB |
839 | |
840 | /* close the old fds */ | |
08ea9270 | 841 | if (options->stdin_fd > STDERR_FILENO) |
a998454a | 842 | close(options->stdin_fd); |
08ea9270 CB |
843 | |
844 | if (options->stdout_fd > STDERR_FILENO) | |
a998454a | 845 | close(options->stdout_fd); |
08ea9270 CB |
846 | |
847 | if (options->stderr_fd > STDERR_FILENO) | |
a998454a CB |
848 | close(options->stderr_fd); |
849 | ||
427a8067 CB |
850 | /* |
851 | * Try to remove FD_CLOEXEC flag from stdin/stdout/stderr, but also | |
a998454a CB |
852 | * here, ignore errors. |
853 | */ | |
427a8067 | 854 | for (int fd = STDIN_FILENO; fd <= STDERR_FILENO; fd++) { |
3f62938a | 855 | ret = fd_cloexec(fd, false); |
b75c344c CB |
856 | if (ret < 0) { |
857 | SYSERROR("Failed to clear FD_CLOEXEC from file descriptor %d", fd); | |
858 | goto on_error; | |
859 | } | |
a998454a CB |
860 | } |
861 | ||
9e84479f | 862 | if (options->attach_flags & LXC_ATTACH_TERMINAL) { |
cecf3e83 | 863 | ret = lxc_terminal_prepare_login(payload->terminal_pts_fd); |
ba2be1a8 | 864 | if (ret < 0) { |
cecf3e83 | 865 | SYSERROR("Failed to prepare terminal file descriptor %d", payload->terminal_pts_fd); |
ba2be1a8 CB |
866 | goto on_error; |
867 | } | |
ea918412 | 868 | |
cecf3e83 | 869 | TRACE("Prepared terminal file descriptor %d", payload->terminal_pts_fd); |
ba2be1a8 CB |
870 | } |
871 | ||
936efc72 CB |
872 | /* Avoid unnecessary syscalls. */ |
873 | if (new_uid == ns_root_uid) | |
874 | new_uid = LXC_INVALID_UID; | |
875 | ||
876 | if (new_gid == ns_root_gid) | |
877 | new_gid = LXC_INVALID_GID; | |
c353b0b9 | 878 | |
6aff5157 | 879 | /* Make sure that the processes STDIO is correctly owned by the user that we are switching to */ |
c353b0b9 CB |
880 | ret = fix_stdio_permissions(new_uid); |
881 | if (ret) | |
882 | WARN("Failed to ajust stdio permissions"); | |
936efc72 | 883 | |
464c4611 | 884 | if (!lxc_switch_uid_gid(new_uid, new_gid)) |
936efc72 CB |
885 | goto on_error; |
886 | ||
a998454a | 887 | /* We're done, so we can now do whatever the user intended us to do. */ |
c7ac2e1c | 888 | _exit(payload->exec_function(payload->exec_payload)); |
b75c344c CB |
889 | |
890 | on_error: | |
ba2be1a8 | 891 | lxc_put_attach_clone_payload(payload); |
c7ac2e1c | 892 | _exit(EXIT_FAILURE); |
a998454a CB |
893 | } |
894 | ||
9e84479f CB |
895 | static int lxc_attach_terminal(struct lxc_conf *conf, |
896 | struct lxc_terminal *terminal) | |
ba2be1a8 CB |
897 | { |
898 | int ret; | |
899 | ||
9e84479f | 900 | lxc_terminal_init(terminal); |
ba2be1a8 | 901 | |
9e84479f | 902 | ret = lxc_terminal_create(terminal); |
c2af3a15 CB |
903 | if (ret < 0) |
904 | return log_error(-1, "Failed to create terminal"); | |
ba2be1a8 CB |
905 | |
906 | /* Shift ttys to container. */ | |
9e84479f | 907 | ret = lxc_terminal_map_ids(conf, terminal); |
ba2be1a8 | 908 | if (ret < 0) { |
9e84479f | 909 | ERROR("Failed to chown terminal"); |
ba2be1a8 CB |
910 | goto on_error; |
911 | } | |
912 | ||
913 | return 0; | |
914 | ||
915 | on_error: | |
9e84479f CB |
916 | lxc_terminal_delete(terminal); |
917 | lxc_terminal_conf_free(terminal); | |
ba2be1a8 CB |
918 | return -1; |
919 | } | |
920 | ||
9e84479f CB |
921 | static int lxc_attach_terminal_mainloop_init(struct lxc_terminal *terminal, |
922 | struct lxc_epoll_descr *descr) | |
ba2be1a8 CB |
923 | { |
924 | int ret; | |
925 | ||
926 | ret = lxc_mainloop_open(descr); | |
c2af3a15 CB |
927 | if (ret < 0) |
928 | return log_error(-1, "Failed to create mainloop"); | |
ba2be1a8 | 929 | |
9e84479f | 930 | ret = lxc_terminal_mainloop_add(descr, terminal); |
ba2be1a8 | 931 | if (ret < 0) { |
ba2be1a8 | 932 | lxc_mainloop_close(descr); |
c2af3a15 | 933 | return log_error(-1, "Failed to add handlers to mainloop"); |
ba2be1a8 CB |
934 | } |
935 | ||
936 | return 0; | |
937 | } | |
938 | ||
cecf3e83 | 939 | static inline void lxc_attach_terminal_close_ptmx(struct lxc_terminal *terminal) |
ba2be1a8 | 940 | { |
cecf3e83 | 941 | close_prot_errno_disarm(terminal->ptmx); |
ba2be1a8 CB |
942 | } |
943 | ||
cecf3e83 | 944 | static inline void lxc_attach_terminal_close_pts(struct lxc_terminal *terminal) |
ba2be1a8 | 945 | { |
cecf3e83 | 946 | close_prot_errno_disarm(terminal->pts); |
ba2be1a8 CB |
947 | } |
948 | ||
9e84479f | 949 | static inline void lxc_attach_terminal_close_peer(struct lxc_terminal *terminal) |
ba2be1a8 | 950 | { |
19a3e906 | 951 | close_prot_errno_disarm(terminal->peer); |
ba2be1a8 CB |
952 | } |
953 | ||
9e84479f | 954 | static inline void lxc_attach_terminal_close_log(struct lxc_terminal *terminal) |
ba2be1a8 | 955 | { |
19a3e906 | 956 | close_prot_errno_disarm(terminal->log_fd); |
ba2be1a8 CB |
957 | } |
958 | ||
908fbc1a CB |
959 | int lxc_attach(struct lxc_container *container, lxc_attach_exec_t exec_function, |
960 | void *exec_payload, lxc_attach_options_t *options, | |
961 | pid_t *attached_process) | |
9c4693b8 | 962 | { |
877f3a04 | 963 | int i, ret, status; |
9c4693b8 | 964 | int ipc_sockets[2]; |
6f4f1937 | 965 | char *cwd, *new_cwd; |
9b8e3c96 | 966 | signed long personality; |
ba2be1a8 | 967 | pid_t attached_pid, init_pid, pid; |
6f4f1937 | 968 | struct lxc_proc_context_info *init_ctx; |
9e84479f | 969 | struct lxc_terminal terminal; |
1cce35e6 | 970 | struct lxc_conf *conf; |
908fbc1a | 971 | char *name, *lxcpath; |
a998454a | 972 | struct attach_clone_payload payload = {0}; |
9c4693b8 | 973 | |
877f3a04 | 974 | ret = access("/proc/self/ns", X_OK); |
c2af3a15 CB |
975 | if (ret) |
976 | return log_error_errno(-1, errno, "Does this kernel version support namespaces?"); | |
877f3a04 | 977 | |
908fbc1a | 978 | if (!container) |
540a2f70 | 979 | return ret_set_errno(-1, EINVAL); |
908fbc1a CB |
980 | |
981 | if (!lxc_container_get(container)) | |
540a2f70 | 982 | return ret_set_errno(-1, EINVAL); |
908fbc1a CB |
983 | |
984 | name = container->name; | |
985 | lxcpath = container->config_path; | |
986 | ||
9c4693b8 CS |
987 | if (!options) |
988 | options = &attach_static_default_options; | |
989 | ||
990 | init_pid = lxc_cmd_get_init_pid(name, lxcpath); | |
991 | if (init_pid < 0) { | |
908fbc1a | 992 | lxc_container_put(container); |
c2af3a15 | 993 | return log_error(-1, "Failed to get init pid"); |
9c4693b8 CS |
994 | } |
995 | ||
996 | init_ctx = lxc_proc_get_context_info(init_pid); | |
997 | if (!init_ctx) { | |
6f4f1937 | 998 | ERROR("Failed to get context of init process: %ld", (long)init_pid); |
908fbc1a | 999 | lxc_container_put(container); |
9c4693b8 CS |
1000 | return -1; |
1001 | } | |
1002 | ||
908fbc1a CB |
1003 | init_ctx->container = container; |
1004 | ||
9b8e3c96 SH |
1005 | personality = get_personality(name, lxcpath); |
1006 | if (init_ctx->personality < 0) { | |
6f4f1937 | 1007 | ERROR("Failed to get personality of the container"); |
9b8e3c96 SH |
1008 | lxc_proc_put_context_info(init_ctx); |
1009 | return -1; | |
1010 | } | |
1011 | init_ctx->personality = personality; | |
1012 | ||
ba773996 CB |
1013 | if (!init_ctx->container->lxc_conf) { |
1014 | init_ctx->container->lxc_conf = lxc_conf_init(); | |
62de1db6 CB |
1015 | if (!init_ctx->container->lxc_conf) { |
1016 | lxc_proc_put_context_info(init_ctx); | |
ea918412 | 1017 | return -1; |
62de1db6 | 1018 | } |
ba773996 | 1019 | } |
1cce35e6 | 1020 | conf = init_ctx->container->lxc_conf; |
a9909116 CB |
1021 | if (!conf) |
1022 | return log_error_errno(-EINVAL, EINVAL, "Missing container confifg"); | |
ba773996 | 1023 | |
bd4307f0 | 1024 | if (!fetch_seccomp(init_ctx->container, options)) |
ae026f55 | 1025 | WARN("Failed to get seccomp policy"); |
2c4ea790 | 1026 | |
bd4307f0 | 1027 | if (!no_new_privs(init_ctx->container, options)) |
ae026f55 | 1028 | WARN("Could not determine whether PR_SET_NO_NEW_PRIVS is set"); |
2e812c16 | 1029 | |
9c4693b8 CS |
1030 | cwd = getcwd(NULL, 0); |
1031 | ||
8ce83369 CB |
1032 | /* Determine which namespaces the container was created with |
1033 | * by asking lxc-start, if necessary. | |
9c4693b8 CS |
1034 | */ |
1035 | if (options->namespaces == -1) { | |
1036 | options->namespaces = lxc_cmd_get_clone_flags(name, lxcpath); | |
1037 | /* call failed */ | |
1038 | if (options->namespaces == -1) { | |
8ce83369 | 1039 | ERROR("Failed to automatically determine the " |
877f3a04 | 1040 | "namespaces which the container uses"); |
9c4693b8 | 1041 | free(cwd); |
fe4de9a6 | 1042 | lxc_proc_put_context_info(init_ctx); |
9c4693b8 CS |
1043 | return -1; |
1044 | } | |
877f3a04 CB |
1045 | |
1046 | for (i = 0; i < LXC_NS_MAX; i++) { | |
1047 | if (ns_info[i].clone_flag & CLONE_NEWCGROUP) | |
1048 | if (!(options->attach_flags & LXC_ATTACH_MOVE_TO_CGROUP) || | |
1049 | !cgns_supported()) | |
1050 | continue; | |
1051 | ||
1052 | if (ns_info[i].clone_flag & options->namespaces) | |
1053 | continue; | |
1054 | ||
1055 | init_ctx->ns_inherited |= ns_info[i].clone_flag; | |
1056 | } | |
1057 | } | |
1058 | ||
0059379f | 1059 | pid = lxc_raw_getpid(); |
ea918412 | 1060 | |
877f3a04 | 1061 | for (i = 0; i < LXC_NS_MAX; i++) { |
ea918412 | 1062 | int j; |
877f3a04 CB |
1063 | |
1064 | if (options->namespaces & ns_info[i].clone_flag) | |
1065 | init_ctx->ns_fd[i] = lxc_preserve_ns(init_pid, ns_info[i].proc_name); | |
1066 | else if (init_ctx->ns_inherited & ns_info[i].clone_flag) | |
1067 | init_ctx->ns_fd[i] = in_same_namespace(pid, init_pid, ns_info[i].proc_name); | |
1068 | else | |
1069 | continue; | |
ea918412 | 1070 | |
877f3a04 CB |
1071 | if (init_ctx->ns_fd[i] >= 0) |
1072 | continue; | |
1073 | ||
1074 | if (init_ctx->ns_fd[i] == -EINVAL) { | |
1075 | DEBUG("Inheriting %s namespace from %d", | |
1076 | ns_info[i].proc_name, pid); | |
1077 | init_ctx->ns_inherited &= ~ns_info[i].clone_flag; | |
1078 | continue; | |
1079 | } | |
1080 | ||
1081 | /* We failed to preserve the namespace. */ | |
ea918412 | 1082 | SYSERROR("Failed to attach to %s namespace of %d", |
1083 | ns_info[i].proc_name, pid); | |
1084 | ||
877f3a04 CB |
1085 | /* Close all already opened file descriptors before we return an |
1086 | * error, so we don't leak them. | |
1087 | */ | |
1088 | for (j = 0; j < i; j++) | |
1089 | close(init_ctx->ns_fd[j]); | |
1090 | ||
877f3a04 CB |
1091 | free(cwd); |
1092 | lxc_proc_put_context_info(init_ctx); | |
1093 | return -1; | |
9c4693b8 CS |
1094 | } |
1095 | ||
9e84479f CB |
1096 | if (options->attach_flags & LXC_ATTACH_TERMINAL) { |
1097 | ret = lxc_attach_terminal(conf, &terminal); | |
ba2be1a8 | 1098 | if (ret < 0) { |
9e84479f | 1099 | ERROR("Failed to setup new terminal"); |
ba2be1a8 CB |
1100 | free(cwd); |
1101 | lxc_proc_put_context_info(init_ctx); | |
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"); |
9c4693b8 | 1146 | free(cwd); |
fe4de9a6 | 1147 | lxc_proc_put_context_info(init_ctx); |
9c4693b8 CS |
1148 | return -1; |
1149 | } | |
1150 | ||
e3f0e436 CB |
1151 | /* Create intermediate subprocess, two reasons: |
1152 | * 1. We can't setns() in the child itself, since we want to make | |
8ce83369 | 1153 | * sure we are properly attached to the pidns. |
e3f0e436 | 1154 | * 2. Also, the initial thread has to put the attached process |
8ce83369 CB |
1155 | * into the cgroup, which we can only do if we didn't already |
1156 | * setns() (otherwise, user namespaces will hate us). | |
9c4693b8 CS |
1157 | */ |
1158 | pid = fork(); | |
9c4693b8 | 1159 | if (pid < 0) { |
ae026f55 | 1160 | SYSERROR("Failed to create first subprocess"); |
9c4693b8 | 1161 | free(cwd); |
fe4de9a6 | 1162 | lxc_proc_put_context_info(init_ctx); |
9c4693b8 CS |
1163 | return -1; |
1164 | } | |
1165 | ||
1166 | if (pid) { | |
ba2be1a8 | 1167 | int ret_parent = -1; |
9c4693b8 | 1168 | pid_t to_cleanup_pid = pid; |
ba2be1a8 | 1169 | struct lxc_epoll_descr descr = {0}; |
9c4693b8 | 1170 | |
ba2be1a8 | 1171 | /* close unneeded file descriptors */ |
9c4693b8 CS |
1172 | close(ipc_sockets[1]); |
1173 | free(cwd); | |
ba2be1a8 | 1174 | lxc_proc_close_ns_fd(init_ctx); |
9e84479f | 1175 | if (options->attach_flags & LXC_ATTACH_TERMINAL) |
cecf3e83 | 1176 | lxc_attach_terminal_close_pts(&terminal); |
9c4693b8 | 1177 | |
8ce83369 | 1178 | /* Attach to cgroup, if requested. */ |
f4364484 | 1179 | if (options->attach_flags & LXC_ATTACH_MOVE_TO_CGROUP) { |
900b6606 CB |
1180 | /* |
1181 | * If this is the unified hierarchy cgroup_attach() is | |
1182 | * enough. | |
1183 | */ | |
7581a82f | 1184 | ret = cgroup_attach(conf, name, lxcpath, pid); |
900b6606 | 1185 | if (ret) { |
5a076633 | 1186 | call_cleaner(cgroup_exit) struct cgroup_ops *cgroup_ops = NULL; |
2202afc9 | 1187 | |
900b6606 CB |
1188 | cgroup_ops = cgroup_init(conf); |
1189 | if (!cgroup_ops) | |
1190 | goto on_error; | |
2202afc9 | 1191 | |
7581a82f | 1192 | if (!cgroup_ops->attach(cgroup_ops, conf, name, lxcpath, pid)) |
900b6606 CB |
1193 | goto on_error; |
1194 | } | |
2202afc9 | 1195 | TRACE("Moved intermediate process %d into container's cgroups", pid); |
f4364484 SG |
1196 | } |
1197 | ||
bb2ada6f | 1198 | /* Setup /proc limits */ |
1cce35e6 CB |
1199 | if (!lxc_list_empty(&conf->procs)) { |
1200 | ret = setup_proc_filesystem(&conf->procs, pid); | |
bb2ada6f CB |
1201 | if (ret < 0) |
1202 | goto on_error; | |
1203 | } | |
1204 | ||
c6d09e15 | 1205 | /* Setup resource limits */ |
1cce35e6 CB |
1206 | if (!lxc_list_empty(&conf->limits)) { |
1207 | ret = setup_resource_limits(&conf->limits, pid); | |
ba2be1a8 CB |
1208 | if (ret < 0) |
1209 | goto on_error; | |
1210 | } | |
1211 | ||
9e84479f CB |
1212 | if (options->attach_flags & LXC_ATTACH_TERMINAL) { |
1213 | ret = lxc_attach_terminal_mainloop_init(&terminal, &descr); | |
ba2be1a8 | 1214 | if (ret < 0) |
6f4f1937 | 1215 | goto on_error; |
ea918412 | 1216 | |
9e84479f | 1217 | TRACE("Initialized terminal mainloop"); |
ba2be1a8 | 1218 | } |
c6d09e15 | 1219 | |
8ce83369 | 1220 | /* Let the child process know to go ahead. */ |
f4364484 SG |
1221 | status = 0; |
1222 | ret = lxc_write_nointr(ipc_sockets[0], &status, sizeof(status)); | |
94ac256f | 1223 | if (ret != sizeof(status)) |
ba2be1a8 | 1224 | goto close_mainloop; |
ea918412 | 1225 | |
94ac256f | 1226 | TRACE("Told intermediate process to start initializing"); |
f4364484 | 1227 | |
8ce83369 | 1228 | /* Get pid of attached process from intermediate process. */ |
94ac256f CB |
1229 | ret = lxc_read_nointr(ipc_sockets[0], &attached_pid, sizeof(attached_pid)); |
1230 | if (ret != sizeof(attached_pid)) | |
ba2be1a8 | 1231 | goto close_mainloop; |
ea918412 | 1232 | |
94ac256f | 1233 | TRACE("Received pid %d of attached process in parent pid namespace", attached_pid); |
9c4693b8 | 1234 | |
8ce83369 | 1235 | /* Ignore SIGKILL (CTRL-C) and SIGQUIT (CTRL-\) - issue #313. */ |
62183f1a SH |
1236 | if (options->stdin_fd == 0) { |
1237 | signal(SIGINT, SIG_IGN); | |
1238 | signal(SIGQUIT, SIG_IGN); | |
1239 | } | |
2eef2bda | 1240 | |
8ce83369 | 1241 | /* Reap intermediate process. */ |
9c4693b8 CS |
1242 | ret = wait_for_pid(pid); |
1243 | if (ret < 0) | |
ba2be1a8 | 1244 | goto close_mainloop; |
ea918412 | 1245 | |
94ac256f | 1246 | TRACE("Intermediate process %d exited", pid); |
9c4693b8 | 1247 | |
8ce83369 | 1248 | /* We will always have to reap the attached process now. */ |
9c4693b8 CS |
1249 | to_cleanup_pid = attached_pid; |
1250 | ||
81f466d0 | 1251 | /* Open LSM fd and send it to child. */ |
6f4f1937 CB |
1252 | if ((options->namespaces & CLONE_NEWNS) && |
1253 | (options->attach_flags & LXC_ATTACH_LSM) && | |
1254 | init_ctx->lsm_label) { | |
47ce2cb7 CB |
1255 | int labelfd; |
1256 | bool on_exec; | |
6f4f1937 | 1257 | |
a7547c5c | 1258 | ret = -1; |
47ce2cb7 CB |
1259 | on_exec = options->attach_flags & LXC_ATTACH_LSM_EXEC ? true : false; |
1260 | labelfd = lsm_process_label_fd_get(attached_pid, on_exec); | |
81f466d0 | 1261 | if (labelfd < 0) |
ba2be1a8 | 1262 | goto close_mainloop; |
ea918412 | 1263 | |
94ac256f | 1264 | TRACE("Opened LSM label file descriptor %d", labelfd); |
81f466d0 CB |
1265 | |
1266 | /* Send child fd of the LSM security module to write to. */ | |
ae467c54 | 1267 | ret = lxc_abstract_unix_send_fds(ipc_sockets[0], &labelfd, 1, NULL, 0); |
81f466d0 | 1268 | if (ret <= 0) { |
9044b79e | 1269 | if (ret < 0) |
1270 | SYSERROR("Failed to send lsm label fd"); | |
1271 | ||
1272 | close(labelfd); | |
ba2be1a8 | 1273 | goto close_mainloop; |
81f466d0 | 1274 | } |
9044b79e | 1275 | |
1276 | close(labelfd); | |
94ac256f | 1277 | TRACE("Sent LSM label file descriptor %d to child", labelfd); |
81f466d0 CB |
1278 | } |
1279 | ||
a9909116 | 1280 | if (conf->seccomp.seccomp) { |
2ac0f627 CB |
1281 | ret = lxc_seccomp_recv_notifier_fd(&conf->seccomp, ipc_sockets[0]); |
1282 | if (ret < 0) | |
1283 | goto close_mainloop; | |
cdb2a47f | 1284 | |
2ac0f627 CB |
1285 | ret = lxc_seccomp_add_notifier(name, lxcpath, &conf->seccomp); |
1286 | if (ret < 0) | |
1287 | goto close_mainloop; | |
1288 | } | |
cdb2a47f | 1289 | |
8ce83369 CB |
1290 | /* We're done, the child process should now execute whatever it |
1291 | * is that the user requested. The parent can now track it with | |
1292 | * waitpid() or similar. | |
9c4693b8 CS |
1293 | */ |
1294 | ||
1295 | *attached_process = attached_pid; | |
9c4693b8 | 1296 | |
ba2be1a8 | 1297 | /* Now shut down communication with child, we're done. */ |
9c4693b8 CS |
1298 | shutdown(ipc_sockets[0], SHUT_RDWR); |
1299 | close(ipc_sockets[0]); | |
ba2be1a8 CB |
1300 | ipc_sockets[0] = -1; |
1301 | ||
1302 | ret_parent = 0; | |
1303 | to_cleanup_pid = -1; | |
ea918412 | 1304 | |
9e84479f | 1305 | if (options->attach_flags & LXC_ATTACH_TERMINAL) { |
ba2be1a8 CB |
1306 | ret = lxc_mainloop(&descr, -1); |
1307 | if (ret < 0) { | |
1308 | ret_parent = -1; | |
1309 | to_cleanup_pid = attached_pid; | |
1310 | } | |
1311 | } | |
1312 | ||
1313 | close_mainloop: | |
9e84479f | 1314 | if (options->attach_flags & LXC_ATTACH_TERMINAL) |
ba2be1a8 CB |
1315 | lxc_mainloop_close(&descr); |
1316 | ||
1317 | on_error: | |
1318 | if (ipc_sockets[0] >= 0) { | |
1319 | shutdown(ipc_sockets[0], SHUT_RDWR); | |
1320 | close(ipc_sockets[0]); | |
1321 | } | |
1322 | ||
1323 | if (to_cleanup_pid > 0) | |
6f4f1937 | 1324 | (void)wait_for_pid(to_cleanup_pid); |
ba2be1a8 | 1325 | |
9e84479f CB |
1326 | if (options->attach_flags & LXC_ATTACH_TERMINAL) { |
1327 | lxc_terminal_delete(&terminal); | |
1328 | lxc_terminal_conf_free(&terminal); | |
ba2be1a8 | 1329 | } |
ea918412 | 1330 | |
fe4de9a6 | 1331 | lxc_proc_put_context_info(init_ctx); |
ba2be1a8 | 1332 | return ret_parent; |
9c4693b8 CS |
1333 | } |
1334 | ||
ba2be1a8 | 1335 | /* close unneeded file descriptors */ |
8bc2b675 | 1336 | close_prot_errno_disarm(ipc_sockets[0]); |
ea918412 | 1337 | |
9e84479f | 1338 | if (options->attach_flags & LXC_ATTACH_TERMINAL) { |
cecf3e83 | 1339 | lxc_attach_terminal_close_ptmx(&terminal); |
9e84479f CB |
1340 | lxc_attach_terminal_close_peer(&terminal); |
1341 | lxc_attach_terminal_close_log(&terminal); | |
ba2be1a8 | 1342 | } |
9c4693b8 | 1343 | |
8ce83369 | 1344 | /* Wait for the parent to have setup cgroups. */ |
94ac256f | 1345 | ret = lxc_read_nointr(ipc_sockets[1], &status, sizeof(status)); |
ba2be1a8 | 1346 | if (ret != sizeof(status)) { |
f4364484 | 1347 | shutdown(ipc_sockets[1], SHUT_RDWR); |
62de1db6 | 1348 | lxc_proc_put_context_info(init_ctx); |
c7ac2e1c | 1349 | _exit(EXIT_FAILURE); |
f4364484 | 1350 | } |
ea918412 | 1351 | |
94ac256f | 1352 | TRACE("Intermediate process starting to initialize"); |
f4364484 | 1353 | |
8ce83369 CB |
1354 | /* Attach now, create another subprocess later, since pid namespaces |
1355 | * only really affect the children of the current process. | |
9c4693b8 | 1356 | */ |
877f3a04 | 1357 | ret = lxc_attach_to_ns(init_pid, init_ctx); |
9c4693b8 | 1358 | if (ret < 0) { |
94ac256f | 1359 | ERROR("Failed to enter namespaces"); |
9c4693b8 | 1360 | shutdown(ipc_sockets[1], SHUT_RDWR); |
62de1db6 | 1361 | lxc_proc_put_context_info(init_ctx); |
c7ac2e1c | 1362 | _exit(EXIT_FAILURE); |
9c4693b8 | 1363 | } |
ea918412 | 1364 | |
877f3a04 CB |
1365 | /* close namespace file descriptors */ |
1366 | lxc_proc_close_ns_fd(init_ctx); | |
9c4693b8 | 1367 | |
8ce83369 | 1368 | /* Attach succeeded, try to cwd. */ |
9c4693b8 CS |
1369 | if (options->initial_cwd) |
1370 | new_cwd = options->initial_cwd; | |
1371 | else | |
1372 | new_cwd = cwd; | |
d6d979bc CB |
1373 | if (new_cwd) { |
1374 | ret = chdir(new_cwd); | |
1375 | if (ret < 0) | |
1376 | WARN("Could not change directory to \"%s\"", new_cwd); | |
1377 | } | |
9c4693b8 CS |
1378 | free(cwd); |
1379 | ||
a998454a CB |
1380 | /* Create attached process. */ |
1381 | payload.ipc_socket = ipc_sockets[1]; | |
1382 | payload.options = options; | |
1383 | payload.init_ctx = init_ctx; | |
cecf3e83 | 1384 | payload.terminal_pts_fd = terminal.pts; |
a998454a CB |
1385 | payload.exec_function = exec_function; |
1386 | payload.exec_payload = exec_payload; | |
9c4693b8 | 1387 | |
a59440be | 1388 | pid = lxc_raw_clone(CLONE_PARENT, NULL); |
a998454a | 1389 | if (pid < 0) { |
94ac256f | 1390 | SYSERROR("Failed to clone attached process"); |
9c4693b8 | 1391 | shutdown(ipc_sockets[1], SHUT_RDWR); |
62de1db6 | 1392 | lxc_proc_put_context_info(init_ctx); |
c7ac2e1c | 1393 | _exit(EXIT_FAILURE); |
9c4693b8 | 1394 | } |
a998454a CB |
1395 | |
1396 | if (pid == 0) { | |
f157b056 CB |
1397 | if (options->attach_flags & LXC_ATTACH_TERMINAL) { |
1398 | ret = pthread_sigmask(SIG_SETMASK, | |
1399 | &terminal.tty_state->oldmask, NULL); | |
1400 | if (ret < 0) { | |
1401 | SYSERROR("Failed to reset signal mask"); | |
1402 | _exit(EXIT_FAILURE); | |
1403 | } | |
1404 | } | |
1405 | ||
a998454a CB |
1406 | ret = attach_child_main(&payload); |
1407 | if (ret < 0) | |
1408 | ERROR("Failed to exec"); | |
ea918412 | 1409 | |
a998454a CB |
1410 | _exit(EXIT_FAILURE); |
1411 | } | |
ea918412 | 1412 | |
9e84479f | 1413 | if (options->attach_flags & LXC_ATTACH_TERMINAL) |
cecf3e83 | 1414 | lxc_attach_terminal_close_pts(&terminal); |
9c4693b8 | 1415 | |
8ce83369 | 1416 | /* Tell grandparent the pid of the pid of the newly created child. */ |
9c4693b8 CS |
1417 | ret = lxc_write_nointr(ipc_sockets[1], &pid, sizeof(pid)); |
1418 | if (ret != sizeof(pid)) { | |
8ce83369 CB |
1419 | /* If this really happens here, this is very unfortunate, since |
1420 | * the parent will not know the pid of the attached process and | |
1421 | * will not be able to wait for it (and we won't either due to | |
1422 | * CLONE_PARENT) so the parent won't be able to reap it and the | |
1423 | * attached process will remain a zombie. | |
9c4693b8 | 1424 | */ |
9c4693b8 | 1425 | shutdown(ipc_sockets[1], SHUT_RDWR); |
62de1db6 | 1426 | lxc_proc_put_context_info(init_ctx); |
c7ac2e1c | 1427 | _exit(EXIT_FAILURE); |
9c4693b8 | 1428 | } |
ea918412 | 1429 | |
94ac256f | 1430 | TRACE("Sending pid %d of attached process", pid); |
9c4693b8 | 1431 | |
8ce83369 | 1432 | /* The rest is in the hands of the initial and the attached process. */ |
62de1db6 | 1433 | lxc_proc_put_context_info(init_ctx); |
57017714 | 1434 | _exit(EXIT_SUCCESS); |
9c4693b8 CS |
1435 | } |
1436 | ||
06346bb0 | 1437 | int lxc_attach_run_command(void *payload) |
9c4693b8 | 1438 | { |
06346bb0 CB |
1439 | int ret = -1; |
1440 | lxc_attach_command_t *cmd = payload; | |
9c4693b8 | 1441 | |
06346bb0 CB |
1442 | ret = execvp(cmd->program, cmd->argv); |
1443 | if (ret < 0) { | |
1444 | switch (errno) { | |
1445 | case ENOEXEC: | |
1446 | ret = 126; | |
cf0fd972 | 1447 | break; |
06346bb0 CB |
1448 | case ENOENT: |
1449 | ret = 127; | |
cf0fd972 | 1450 | break; |
06346bb0 CB |
1451 | } |
1452 | } | |
ea918412 | 1453 | |
c2af3a15 | 1454 | return log_error_errno(ret, errno, "Failed to exec \"%s\"", cmd->program); |
9c4693b8 CS |
1455 | } |
1456 | ||
1457 | int lxc_attach_run_shell(void* payload) | |
1458 | { | |
cd8f5663 | 1459 | __do_free char *buf = NULL; |
9c4693b8 | 1460 | uid_t uid; |
cb7aa5e8 DJ |
1461 | struct passwd pwent; |
1462 | struct passwd *pwentp = NULL; | |
9c4693b8 | 1463 | char *user_shell; |
cb7aa5e8 DJ |
1464 | size_t bufsize; |
1465 | int ret; | |
9c4693b8 | 1466 | |
8ce83369 | 1467 | /* Ignore payload parameter. */ |
9c4693b8 CS |
1468 | (void)payload; |
1469 | ||
1470 | uid = getuid(); | |
cb7aa5e8 DJ |
1471 | |
1472 | bufsize = sysconf(_SC_GETPW_R_SIZE_MAX); | |
1473 | if (bufsize == -1) | |
1474 | bufsize = 1024; | |
1475 | ||
1476 | buf = malloc(bufsize); | |
1477 | if (buf) { | |
1478 | ret = getpwuid_r(uid, &pwent, buf, bufsize, &pwentp); | |
1479 | if (!pwentp) { | |
1480 | if (ret == 0) | |
ea918412 | 1481 | WARN("Could not find matched password record"); |
cb7aa5e8 DJ |
1482 | |
1483 | WARN("Failed to get password record - %u", uid); | |
1484 | } | |
1485 | } | |
9c4693b8 | 1486 | |
8ce83369 CB |
1487 | /* This probably happens because of incompatible nss implementations in |
1488 | * host and container (remember, this code is still using the host's | |
1489 | * glibc but our mount namespace is in the container) we may try to get | |
1490 | * the information by spawning a [getent passwd uid] process and parsing | |
1491 | * the result. | |
9c4693b8 | 1492 | */ |
cb7aa5e8 | 1493 | if (!pwentp) |
9c4693b8 CS |
1494 | user_shell = lxc_attach_getpwshell(uid); |
1495 | else | |
cb7aa5e8 | 1496 | user_shell = pwent.pw_shell; |
ea918412 | 1497 | |
9c4693b8 | 1498 | if (user_shell) |
acf47e1b | 1499 | execlp(user_shell, user_shell, (char *)NULL); |
9c4693b8 | 1500 | |
8ce83369 CB |
1501 | /* Executed if either no passwd entry or execvp fails, we will fall back |
1502 | * on /bin/sh as a default shell. | |
9c4693b8 | 1503 | */ |
acf47e1b | 1504 | execlp("/bin/sh", "/bin/sh", (char *)NULL); |
ea918412 | 1505 | |
edeb1836 | 1506 | SYSERROR("Failed to execute shell"); |
cb7aa5e8 | 1507 | if (!pwentp) |
edeb1836 | 1508 | free(user_shell); |
ea918412 | 1509 | |
9c4693b8 CS |
1510 | return -1; |
1511 | } |