Commit | Line | Data |
---|---|---|
60b6c79c MD |
1 | /* |
2 | * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca> | |
3 | * Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
4 | * | |
d14d33bf AM |
5 | * This program is free software; you can redistribute it and/or modify |
6 | * it under the terms of the GNU General Public License, version 2 only, | |
7 | * as published by the Free Software Foundation. | |
60b6c79c MD |
8 | * |
9 | * This program is distributed in the hope that it will be useful, but WITHOUT | |
10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
d14d33bf | 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for |
60b6c79c MD |
12 | * more details. |
13 | * | |
d14d33bf AM |
14 | * You should have received a copy of the GNU General Public License along |
15 | * with this program; if not, write to the Free Software Foundation, Inc., | |
16 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. | |
60b6c79c MD |
17 | */ |
18 | ||
6c1c0768 | 19 | #define _LGPL_SOURCE |
60b6c79c MD |
20 | #include <errno.h> |
21 | #include <limits.h> | |
22 | #include <stdio.h> | |
23 | #include <stdlib.h> | |
24 | #include <string.h> | |
25 | #include <sys/wait.h> | |
26 | #include <sys/types.h> | |
27 | #include <sys/stat.h> | |
28 | #include <unistd.h> | |
29 | #include <fcntl.h> | |
c2b75c49 | 30 | #include <sched.h> |
0452bf08 | 31 | #include <signal.h> |
749b7a0c | 32 | #include <assert.h> |
e1055edb | 33 | #include <signal.h> |
60b6c79c | 34 | |
0ef03255 | 35 | #include <common/lttng-kernel.h> |
90e535ef | 36 | #include <common/common.h> |
3fd15a74 | 37 | #include <common/utils.h> |
e8fa9fb0 | 38 | #include <common/compat/getenv.h> |
e1055edb | 39 | #include <common/compat/prctl.h> |
2038dd6c JG |
40 | #include <common/unix.h> |
41 | #include <common/defaults.h> | |
241e0a5a FD |
42 | #include <common/lttng-elf.h> |
43 | ||
44 | #include <lttng/constant.h> | |
60b6c79c | 45 | |
0857097f DG |
46 | #include "runas.h" |
47 | ||
7567352f | 48 | struct run_as_data; |
fe9f7760 FD |
49 | struct run_as_ret; |
50 | typedef int (*run_as_fct)(struct run_as_data *data, struct run_as_ret *ret_value); | |
c2b75c49 | 51 | |
e11d277b | 52 | struct run_as_mkdir_data { |
7567352f | 53 | char path[PATH_MAX]; |
60b6c79c MD |
54 | mode_t mode; |
55 | }; | |
56 | ||
e11d277b | 57 | struct run_as_open_data { |
7567352f | 58 | char path[PATH_MAX]; |
60b6c79c MD |
59 | int flags; |
60 | mode_t mode; | |
61 | }; | |
62 | ||
4628484a | 63 | struct run_as_unlink_data { |
7567352f | 64 | char path[PATH_MAX]; |
4628484a MD |
65 | }; |
66 | ||
7567352f MD |
67 | struct run_as_rmdir_recursive_data { |
68 | char path[PATH_MAX]; | |
69 | }; | |
70 | ||
241e0a5a FD |
71 | struct run_as_extract_elf_symbol_offset_data { |
72 | char function[LTTNG_SYMBOL_NAME_LEN]; | |
73 | }; | |
74 | ||
0ef03255 FD |
75 | struct run_as_extract_sdt_probe_offsets_data { |
76 | char probe_name[LTTNG_SYMBOL_NAME_LEN]; | |
77 | char provider_name[LTTNG_SYMBOL_NAME_LEN]; | |
78 | }; | |
79 | ||
fe9f7760 FD |
80 | struct run_as_mkdir_ret { |
81 | int ret; | |
82 | }; | |
83 | ||
84 | struct run_as_open_ret { | |
85 | int ret; | |
86 | }; | |
87 | ||
88 | struct run_as_unlink_ret { | |
89 | int ret; | |
90 | }; | |
91 | ||
92 | struct run_as_rmdir_recursive_ret { | |
93 | int ret; | |
94 | }; | |
95 | ||
241e0a5a FD |
96 | struct run_as_extract_elf_symbol_offset_ret { |
97 | uint64_t offset; | |
98 | }; | |
99 | ||
0ef03255 FD |
100 | struct run_as_extract_sdt_probe_offsets_ret { |
101 | uint32_t num_offset; | |
102 | uint64_t offsets[LTTNG_KERNEL_MAX_UPROBE_NUM]; | |
103 | }; | |
104 | ||
7567352f MD |
105 | enum run_as_cmd { |
106 | RUN_AS_MKDIR, | |
107 | RUN_AS_OPEN, | |
108 | RUN_AS_UNLINK, | |
109 | RUN_AS_RMDIR_RECURSIVE, | |
110 | RUN_AS_MKDIR_RECURSIVE, | |
241e0a5a | 111 | RUN_AS_EXTRACT_ELF_SYMBOL_OFFSET, |
0ef03255 | 112 | RUN_AS_EXTRACT_SDT_PROBE_OFFSETS, |
7567352f MD |
113 | }; |
114 | ||
115 | struct run_as_data { | |
116 | enum run_as_cmd cmd; | |
fe9f7760 | 117 | int fd; |
7567352f MD |
118 | union { |
119 | struct run_as_mkdir_data mkdir; | |
120 | struct run_as_open_data open; | |
121 | struct run_as_unlink_data unlink; | |
122 | struct run_as_rmdir_recursive_data rmdir_recursive; | |
241e0a5a | 123 | struct run_as_extract_elf_symbol_offset_data extract_elf_symbol_offset; |
0ef03255 | 124 | struct run_as_extract_sdt_probe_offsets_data extract_sdt_probe_offsets; |
7567352f MD |
125 | } u; |
126 | uid_t uid; | |
127 | gid_t gid; | |
4628484a MD |
128 | }; |
129 | ||
fe9f7760 FD |
130 | /* |
131 | * The run_as_ret structure holds the returned value and status of the command. | |
132 | * | |
133 | * The `u` union field holds the return value of the command; in most cases it | |
134 | * represents the success or the failure of the command. In more complex | |
135 | * commands, it holds a computed value. | |
136 | * | |
137 | * The _errno field is the errno recorded after the execution of the command. | |
138 | * | |
139 | * The _error fields is used the signify that return status of the command. For | |
140 | * simple commands returning `int` the _error field will be the same as the | |
141 | * ret_int field. In complex commands, it signify the success or failure of the | |
142 | * command. | |
143 | * | |
144 | */ | |
df5b86c8 | 145 | struct run_as_ret { |
fe9f7760 FD |
146 | int fd; |
147 | union { | |
148 | struct run_as_mkdir_ret mkdir; | |
149 | struct run_as_open_ret open; | |
150 | struct run_as_unlink_ret unlink; | |
151 | struct run_as_rmdir_recursive_ret rmdir_recursive; | |
241e0a5a | 152 | struct run_as_extract_elf_symbol_offset_ret extract_elf_symbol_offset; |
0ef03255 | 153 | struct run_as_extract_sdt_probe_offsets_ret extract_sdt_probe_offsets; |
fe9f7760 | 154 | } u; |
df5b86c8 | 155 | int _errno; |
fe9f7760 | 156 | bool _error; |
df5b86c8 MD |
157 | }; |
158 | ||
7567352f MD |
159 | struct run_as_worker { |
160 | pid_t pid; /* Worker PID. */ | |
161 | int sockpair[2]; | |
162 | char *procname; | |
163 | }; | |
164 | ||
165 | /* Single global worker per process (for now). */ | |
166 | static struct run_as_worker *global_worker; | |
167 | /* Lock protecting the worker. */ | |
168 | static pthread_mutex_t worker_lock = PTHREAD_MUTEX_INITIALIZER; | |
169 | ||
8f0044bf MD |
170 | #ifdef VALGRIND |
171 | static | |
172 | int use_clone(void) | |
173 | { | |
174 | return 0; | |
175 | } | |
176 | #else | |
177 | static | |
178 | int use_clone(void) | |
179 | { | |
e8fa9fb0 | 180 | return !lttng_secure_getenv("LTTNG_DEBUG_NOCLONE"); |
8f0044bf MD |
181 | } |
182 | #endif | |
183 | ||
d77dded2 JG |
184 | LTTNG_HIDDEN |
185 | int _utils_mkdir_recursive_unsafe(const char *path, mode_t mode); | |
186 | ||
60b6c79c MD |
187 | /* |
188 | * Create recursively directory using the FULL path. | |
189 | */ | |
190 | static | |
fe9f7760 | 191 | int _mkdir_recursive(struct run_as_data *data, struct run_as_ret *ret_value) |
60b6c79c | 192 | { |
60b6c79c | 193 | const char *path; |
60b6c79c | 194 | mode_t mode; |
60b6c79c | 195 | |
7567352f MD |
196 | path = data->u.mkdir.path; |
197 | mode = data->u.mkdir.mode; | |
60b6c79c | 198 | |
d77dded2 | 199 | /* Safe to call as we have transitioned to the requested uid/gid. */ |
fe9f7760 FD |
200 | ret_value->u.mkdir.ret = _utils_mkdir_recursive_unsafe(path, mode); |
201 | ret_value->_errno = errno; | |
202 | ret_value->_error = (ret_value->u.mkdir.ret) ? true : false; | |
203 | return ret_value->u.mkdir.ret; | |
60b6c79c MD |
204 | } |
205 | ||
206 | static | |
fe9f7760 | 207 | int _mkdir(struct run_as_data *data, struct run_as_ret *ret_value) |
60b6c79c | 208 | { |
fe9f7760 FD |
209 | ret_value->u.mkdir.ret = mkdir(data->u.mkdir.path, data->u.mkdir.mode); |
210 | ret_value->_errno = errno; | |
211 | ret_value->_error = (ret_value->u.mkdir.ret) ? true : false; | |
212 | return ret_value->u.mkdir.ret; | |
7567352f | 213 | } |
7ce36756 | 214 | |
7567352f | 215 | static |
fe9f7760 | 216 | int _open(struct run_as_data *data, struct run_as_ret *ret_value) |
7567352f | 217 | { |
fe9f7760 FD |
218 | ret_value->u.open.ret = open(data->u.open.path, data->u.open.flags, data->u.open.mode); |
219 | ret_value->fd = ret_value->u.open.ret; | |
220 | ret_value->_errno = errno; | |
221 | ret_value->_error = (ret_value->u.open.ret) ? true : false; | |
222 | return ret_value->u.open.ret; | |
7567352f MD |
223 | } |
224 | ||
225 | static | |
fe9f7760 | 226 | int _unlink(struct run_as_data *data, struct run_as_ret *ret_value) |
7567352f | 227 | { |
fe9f7760 FD |
228 | ret_value->u.unlink.ret = unlink(data->u.unlink.path); |
229 | ret_value->_errno = errno; | |
230 | ret_value->_error = (ret_value->u.unlink.ret) ? true : false; | |
231 | return ret_value->u.unlink.ret; | |
60b6c79c MD |
232 | } |
233 | ||
234 | static | |
fe9f7760 | 235 | int _rmdir_recursive(struct run_as_data *data, struct run_as_ret *ret_value) |
60b6c79c | 236 | { |
fe9f7760 FD |
237 | ret_value->u.rmdir_recursive.ret = utils_recursive_rmdir(data->u.rmdir_recursive.path); |
238 | ret_value->_errno = errno; | |
239 | ret_value->_error = (ret_value->u.rmdir_recursive.ret) ? true : false; | |
240 | return ret_value->u.rmdir_recursive.ret; | |
7567352f | 241 | } |
df5b86c8 | 242 | |
241e0a5a FD |
243 | static |
244 | int _extract_elf_symbol_offset(struct run_as_data *data, | |
245 | struct run_as_ret *ret_value) | |
246 | { | |
247 | int ret = 0; | |
248 | ret_value->_error = false; | |
249 | ||
250 | ret = lttng_elf_get_symbol_offset(data->fd, | |
251 | data->u.extract_elf_symbol_offset.function, | |
252 | &ret_value->u.extract_elf_symbol_offset.offset); | |
253 | if (ret) { | |
254 | DBG("Failed to extract ELF function offset"); | |
255 | ret_value->_error = true; | |
256 | } | |
257 | ||
258 | return ret; | |
259 | } | |
260 | ||
0ef03255 FD |
261 | static |
262 | int _extract_sdt_probe_offsets(struct run_as_data *data, | |
263 | struct run_as_ret *ret_value) | |
264 | { | |
265 | int ret = 0; | |
266 | uint64_t *offsets = NULL; | |
267 | uint32_t num_offset; | |
268 | ||
269 | ret_value->_error = false; | |
270 | ||
271 | /* On success, this call allocates the offsets paramater. */ | |
272 | ret = lttng_elf_get_sdt_probe_offsets(data->fd, | |
273 | data->u.extract_sdt_probe_offsets.provider_name, | |
274 | data->u.extract_sdt_probe_offsets.probe_name, | |
275 | &offsets, &num_offset); | |
276 | ||
277 | if (ret) { | |
278 | DBG("Failed to extract SDT probe offsets"); | |
279 | ret_value->_error = true; | |
280 | goto end; | |
281 | } | |
282 | ||
283 | if (num_offset <= 0 || num_offset > LTTNG_KERNEL_MAX_UPROBE_NUM) { | |
284 | DBG("Wrong number of probes."); | |
285 | ret = -1; | |
286 | ret_value->_error = true; | |
287 | goto free_offset; | |
288 | } | |
289 | ||
290 | /* Copy the content of the offsets array to the ret struct. */ | |
291 | memcpy(ret_value->u.extract_sdt_probe_offsets.offsets, | |
292 | offsets, num_offset * sizeof(uint64_t)); | |
293 | ||
294 | ret_value->u.extract_sdt_probe_offsets.num_offset = num_offset; | |
295 | ||
296 | free_offset: | |
297 | free(offsets); | |
298 | end: | |
299 | return ret; | |
300 | } | |
241e0a5a | 301 | |
7567352f MD |
302 | static |
303 | run_as_fct run_as_enum_to_fct(enum run_as_cmd cmd) | |
304 | { | |
305 | switch (cmd) { | |
306 | case RUN_AS_MKDIR: | |
307 | return _mkdir; | |
308 | case RUN_AS_OPEN: | |
309 | return _open; | |
310 | case RUN_AS_UNLINK: | |
311 | return _unlink; | |
312 | case RUN_AS_RMDIR_RECURSIVE: | |
313 | return _rmdir_recursive; | |
314 | case RUN_AS_MKDIR_RECURSIVE: | |
315 | return _mkdir_recursive; | |
241e0a5a FD |
316 | case RUN_AS_EXTRACT_ELF_SYMBOL_OFFSET: |
317 | return _extract_elf_symbol_offset; | |
0ef03255 FD |
318 | case RUN_AS_EXTRACT_SDT_PROBE_OFFSETS: |
319 | return _extract_sdt_probe_offsets; | |
7567352f | 320 | default: |
62a7b8ed | 321 | ERR("Unknown command %d", (int) cmd); |
7567352f MD |
322 | return NULL; |
323 | } | |
60b6c79c MD |
324 | } |
325 | ||
4628484a | 326 | static |
fe9f7760 | 327 | int do_send_fd(int sock, int fd) |
4628484a | 328 | { |
7567352f | 329 | ssize_t len; |
4628484a | 330 | |
7567352f | 331 | if (fd < 0) { |
fe9f7760 | 332 | ERR("Invalid file description"); |
7567352f MD |
333 | return 0; |
334 | } | |
fe9f7760 FD |
335 | |
336 | len = lttcomm_send_fds_unix_sock(sock, &fd, 1); | |
7567352f MD |
337 | if (len < 0) { |
338 | PERROR("lttcomm_send_fds_unix_sock"); | |
339 | return -1; | |
340 | } | |
7567352f | 341 | return 0; |
4628484a MD |
342 | } |
343 | ||
344 | static | |
fe9f7760 | 345 | int do_recv_fd(int sock, int *fd) |
4628484a | 346 | { |
7567352f | 347 | ssize_t len; |
4628484a | 348 | |
7567352f | 349 | if (*fd < 0) { |
fe9f7760 | 350 | ERR("Invalid file description"); |
7567352f MD |
351 | return 0; |
352 | } | |
fe9f7760 FD |
353 | |
354 | len = lttcomm_recv_fds_unix_sock(sock, fd, 1); | |
355 | ||
da9ee832 JG |
356 | if (!len) { |
357 | return -1; | |
358 | } else if (len < 0) { | |
7567352f MD |
359 | PERROR("lttcomm_recv_fds_unix_sock"); |
360 | return -1; | |
361 | } | |
362 | return 0; | |
4628484a MD |
363 | } |
364 | ||
fe9f7760 FD |
365 | static |
366 | int send_fd_to_worker(struct run_as_worker *worker, enum run_as_cmd cmd, int fd) | |
367 | { | |
368 | int ret = 0; | |
369 | ||
370 | switch (cmd) { | |
241e0a5a | 371 | case RUN_AS_EXTRACT_ELF_SYMBOL_OFFSET: |
0ef03255 | 372 | case RUN_AS_EXTRACT_SDT_PROBE_OFFSETS: |
241e0a5a | 373 | break; |
fe9f7760 FD |
374 | default: |
375 | return 0; | |
376 | } | |
377 | ||
378 | ret = do_send_fd(worker->sockpair[0], fd); | |
379 | if (ret < 0) { | |
380 | PERROR("do_send_fd"); | |
381 | ret = -1; | |
382 | } | |
383 | ||
384 | return ret; | |
385 | } | |
386 | ||
387 | static | |
388 | int send_fd_to_master(struct run_as_worker *worker, enum run_as_cmd cmd, int fd) | |
389 | { | |
390 | int ret = 0, ret_close = 0; | |
391 | ||
392 | switch (cmd) { | |
393 | case RUN_AS_OPEN: | |
394 | break; | |
395 | default: | |
396 | return 0; | |
397 | } | |
398 | ||
399 | ret = do_send_fd(worker->sockpair[1], fd); | |
400 | if (ret < 0) { | |
401 | PERROR("do_send_fd error"); | |
402 | ret = -1; | |
403 | } | |
404 | ||
405 | ret_close = close(fd); | |
406 | if (ret_close < 0) { | |
407 | PERROR("close"); | |
408 | } | |
409 | ||
410 | return ret; | |
411 | } | |
412 | ||
413 | static | |
414 | int recv_fd_from_worker(struct run_as_worker *worker, enum run_as_cmd cmd, int *fd) | |
415 | { | |
416 | int ret = 0; | |
417 | ||
418 | switch (cmd) { | |
419 | case RUN_AS_OPEN: | |
420 | break; | |
421 | default: | |
422 | return 0; | |
423 | } | |
424 | ||
425 | ret = do_recv_fd(worker->sockpair[0], fd); | |
426 | if (ret < 0) { | |
427 | PERROR("do_recv_fd error"); | |
428 | ret = -1; | |
429 | } | |
430 | ||
431 | return ret; | |
432 | } | |
433 | ||
434 | static | |
435 | int recv_fd_from_master(struct run_as_worker *worker, enum run_as_cmd cmd, int *fd) | |
436 | { | |
437 | int ret = 0; | |
438 | ||
439 | switch (cmd) { | |
241e0a5a | 440 | case RUN_AS_EXTRACT_ELF_SYMBOL_OFFSET: |
0ef03255 | 441 | case RUN_AS_EXTRACT_SDT_PROBE_OFFSETS: |
241e0a5a | 442 | break; |
fe9f7760 FD |
443 | default: |
444 | return 0; | |
445 | } | |
446 | ||
447 | ret = do_recv_fd(worker->sockpair[1], fd); | |
448 | if (ret < 0) { | |
449 | PERROR("do_recv_fd error"); | |
450 | ret = -1; | |
451 | } | |
452 | ||
453 | return ret; | |
454 | } | |
455 | ||
456 | static | |
457 | int cleanup_received_fd(enum run_as_cmd cmd, int fd) | |
458 | { | |
459 | int ret = 0; | |
460 | ||
461 | switch (cmd) { | |
241e0a5a | 462 | case RUN_AS_EXTRACT_ELF_SYMBOL_OFFSET: |
0ef03255 | 463 | case RUN_AS_EXTRACT_SDT_PROBE_OFFSETS: |
241e0a5a | 464 | break; |
fe9f7760 FD |
465 | default: |
466 | return 0; | |
467 | } | |
468 | ||
469 | ret = close(fd); | |
470 | if (ret < 0) { | |
471 | PERROR("close error"); | |
472 | ret = -1; | |
473 | } | |
474 | ||
475 | return ret; | |
476 | } | |
0ef03255 | 477 | |
7567352f MD |
478 | /* |
479 | * Return < 0 on error, 0 if OK, 1 on hangup. | |
480 | */ | |
c2b75c49 | 481 | static |
7567352f | 482 | int handle_one_cmd(struct run_as_worker *worker) |
c2b75c49 | 483 | { |
7567352f MD |
484 | int ret = 0; |
485 | struct run_as_data data; | |
486 | ssize_t readlen, writelen; | |
df5b86c8 | 487 | struct run_as_ret sendret; |
7567352f MD |
488 | run_as_fct cmd; |
489 | uid_t prev_euid; | |
490 | ||
fe9f7760 FD |
491 | /* |
492 | * Stage 1: Receive run_as_data struct from the master. | |
493 | * The structure contains the command type and all the parameters needed for | |
494 | * its execution | |
495 | */ | |
7567352f MD |
496 | readlen = lttcomm_recv_unix_sock(worker->sockpair[1], &data, |
497 | sizeof(data)); | |
498 | if (readlen == 0) { | |
499 | /* hang up */ | |
500 | ret = 1; | |
501 | goto end; | |
502 | } | |
503 | if (readlen < sizeof(data)) { | |
504 | PERROR("lttcomm_recv_unix_sock error"); | |
505 | ret = -1; | |
506 | goto end; | |
507 | } | |
c2b75c49 | 508 | |
7567352f MD |
509 | cmd = run_as_enum_to_fct(data.cmd); |
510 | if (!cmd) { | |
511 | ret = -1; | |
512 | goto end; | |
513 | } | |
514 | ||
fe9f7760 FD |
515 | /* |
516 | * Stage 2: Receive file descriptor from master. | |
517 | * Some commands need a file descriptor as input so if it's needed we | |
518 | * receive the fd using the Unix socket. | |
519 | */ | |
520 | ret = recv_fd_from_master(worker, data.cmd, &data.fd); | |
521 | if (ret < 0) { | |
522 | PERROR("recv_fd_from_master error"); | |
523 | ret = -1; | |
524 | goto end; | |
525 | } | |
526 | ||
7567352f MD |
527 | prev_euid = getuid(); |
528 | if (data.gid != getegid()) { | |
529 | ret = setegid(data.gid); | |
1576d582 | 530 | if (ret < 0) { |
561f5f2c JG |
531 | sendret._error = true; |
532 | sendret._errno = errno; | |
4c462e79 | 533 | PERROR("setegid"); |
6d73c4ef | 534 | goto write_return; |
1576d582 | 535 | } |
c2b75c49 | 536 | } |
7567352f MD |
537 | if (data.uid != prev_euid) { |
538 | ret = seteuid(data.uid); | |
1576d582 | 539 | if (ret < 0) { |
561f5f2c JG |
540 | sendret._error = true; |
541 | sendret._errno = errno; | |
4c462e79 | 542 | PERROR("seteuid"); |
6d73c4ef | 543 | goto write_return; |
1576d582 | 544 | } |
c2b75c49 | 545 | } |
fe9f7760 | 546 | |
c2b75c49 MD |
547 | /* |
548 | * Also set umask to 0 for mkdir executable bit. | |
549 | */ | |
550 | umask(0); | |
fe9f7760 FD |
551 | |
552 | /* | |
553 | * Stage 3: Execute the command | |
554 | */ | |
555 | ret = (*cmd)(&data, &sendret); | |
556 | if (ret < 0) { | |
557 | DBG("Execution of command returned an error"); | |
558 | } | |
6d73c4ef MD |
559 | |
560 | write_return: | |
fe9f7760 FD |
561 | ret = cleanup_received_fd(data.cmd, data.fd); |
562 | if (ret < 0) { | |
563 | ERR("Error cleaning up FD"); | |
564 | goto end; | |
565 | } | |
566 | ||
567 | /* | |
568 | * Stage 4: Send run_as_ret structure to the master. | |
569 | * This structure contain the return value of the command and the errno. | |
570 | */ | |
7567352f MD |
571 | writelen = lttcomm_send_unix_sock(worker->sockpair[1], &sendret, |
572 | sizeof(sendret)); | |
6cd525e8 | 573 | if (writelen < sizeof(sendret)) { |
7567352f MD |
574 | PERROR("lttcomm_send_unix_sock error"); |
575 | ret = -1; | |
576 | goto end; | |
577 | } | |
fe9f7760 FD |
578 | |
579 | /* | |
580 | * Stage 5: Send file descriptor to the master | |
581 | * Some commands return a file descriptor so if it's needed we pass it back | |
582 | * to the master using the Unix socket. | |
583 | */ | |
584 | ret = send_fd_to_master(worker, data.cmd, sendret.fd); | |
585 | if (ret < 0) { | |
586 | DBG("Sending FD to master returned an error"); | |
7567352f MD |
587 | goto end; |
588 | } | |
fe9f7760 | 589 | |
7567352f MD |
590 | if (seteuid(prev_euid) < 0) { |
591 | PERROR("seteuid"); | |
592 | ret = -1; | |
593 | goto end; | |
594 | } | |
595 | ret = 0; | |
596 | end: | |
597 | return ret; | |
598 | } | |
599 | ||
600 | static | |
601 | int run_as_worker(struct run_as_worker *worker) | |
602 | { | |
603 | int ret; | |
604 | ssize_t writelen; | |
605 | struct run_as_ret sendret; | |
606 | size_t proc_orig_len; | |
607 | ||
608 | /* | |
609 | * Initialize worker. Set a different process cmdline. | |
610 | */ | |
611 | proc_orig_len = strlen(worker->procname); | |
612 | memset(worker->procname, 0, proc_orig_len); | |
613 | strncpy(worker->procname, DEFAULT_RUN_AS_WORKER_NAME, proc_orig_len); | |
614 | ||
e1055edb JG |
615 | ret = lttng_prctl(PR_SET_NAME, |
616 | (unsigned long) DEFAULT_RUN_AS_WORKER_NAME, 0, 0, 0); | |
617 | if (ret && ret != -ENOSYS) { | |
b8090274 JG |
618 | /* Don't fail as this is not essential. */ |
619 | PERROR("prctl PR_SET_NAME"); | |
6cd525e8 | 620 | } |
7567352f | 621 | |
fe9f7760 FD |
622 | memset(&sendret, 0, sizeof(sendret)); |
623 | ||
7567352f MD |
624 | writelen = lttcomm_send_unix_sock(worker->sockpair[1], &sendret, |
625 | sizeof(sendret)); | |
626 | if (writelen < sizeof(sendret)) { | |
627 | PERROR("lttcomm_send_unix_sock error"); | |
628 | ret = EXIT_FAILURE; | |
629 | goto end; | |
630 | } | |
631 | ||
632 | for (;;) { | |
633 | ret = handle_one_cmd(worker); | |
634 | if (ret < 0) { | |
635 | ret = EXIT_FAILURE; | |
636 | goto end; | |
637 | } else if (ret > 0) { | |
638 | break; | |
639 | } else { | |
640 | continue; /* Next command. */ | |
641 | } | |
642 | } | |
643 | ret = EXIT_SUCCESS; | |
644 | end: | |
645 | return ret; | |
c2b75c49 MD |
646 | } |
647 | ||
60b6c79c | 648 | static |
7567352f MD |
649 | int run_as_cmd(struct run_as_worker *worker, |
650 | enum run_as_cmd cmd, | |
651 | struct run_as_data *data, | |
fe9f7760 | 652 | struct run_as_ret *ret_value, |
7567352f | 653 | uid_t uid, gid_t gid) |
60b6c79c | 654 | { |
fe9f7760 | 655 | int ret = 0; |
7567352f | 656 | ssize_t readlen, writelen; |
60b6c79c MD |
657 | |
658 | /* | |
659 | * If we are non-root, we can only deal with our own uid. | |
660 | */ | |
661 | if (geteuid() != 0) { | |
662 | if (uid != geteuid()) { | |
fe9f7760 FD |
663 | ret = -1; |
664 | ret_value->_errno = EPERM; | |
60b6c79c | 665 | ERR("Client (%d)/Server (%d) UID mismatch (and sessiond is not root)", |
08797918 | 666 | (int) uid, (int) geteuid()); |
df5b86c8 | 667 | goto end; |
60b6c79c | 668 | } |
60b6c79c MD |
669 | } |
670 | ||
7567352f MD |
671 | data->cmd = cmd; |
672 | data->uid = uid; | |
673 | data->gid = gid; | |
674 | ||
fe9f7760 FD |
675 | /* |
676 | * Stage 1: Send the run_as_data struct to the worker process | |
677 | */ | |
7567352f MD |
678 | writelen = lttcomm_send_unix_sock(worker->sockpair[0], data, |
679 | sizeof(*data)); | |
680 | if (writelen < sizeof(*data)) { | |
681 | PERROR("Error writing message to run_as"); | |
fe9f7760 FD |
682 | ret = -1; |
683 | ret_value->_errno = EIO; | |
60b6c79c | 684 | goto end; |
c2b75c49 | 685 | } |
7567352f | 686 | |
fe9f7760 FD |
687 | /* |
688 | * Stage 2: Send file descriptor to the worker process if needed | |
689 | */ | |
690 | ret = send_fd_to_worker(worker, data->cmd, data->fd); | |
691 | if (ret) { | |
692 | PERROR("do_send_fd error"); | |
693 | ret = -1; | |
694 | ret_value->_errno = EIO; | |
695 | goto end; | |
696 | } | |
697 | ||
698 | /* | |
699 | * Stage 3: Wait for the execution of the command | |
700 | */ | |
701 | ||
702 | /* | |
703 | * Stage 4: Receive the run_as_ret struct containing the return value and | |
704 | * errno | |
705 | */ | |
706 | readlen = lttcomm_recv_unix_sock(worker->sockpair[0], ret_value, | |
707 | sizeof(*ret_value)); | |
da9ee832 JG |
708 | if (!readlen) { |
709 | ERR("Run-as worker has hung-up during run_as_cmd"); | |
fe9f7760 FD |
710 | ret = -1; |
711 | ret_value->_errno = EIO; | |
da9ee832 | 712 | goto end; |
fe9f7760 | 713 | } else if (readlen < sizeof(*ret_value)) { |
7567352f | 714 | PERROR("Error reading response from run_as"); |
fe9f7760 FD |
715 | ret = -1; |
716 | ret_value->_errno = errno; | |
033b58a7 | 717 | goto end; |
6cd525e8 | 718 | } |
fe9f7760 FD |
719 | |
720 | /* | |
721 | * Stage 5: Receive file descriptor if needed | |
722 | */ | |
723 | ret = recv_fd_from_worker(worker, data->cmd, &ret_value->fd); | |
724 | if (ret < 0) { | |
725 | ERR("Error receiving fd"); | |
726 | ret = -1; | |
727 | ret_value->_errno = EIO; | |
4c462e79 | 728 | } |
7567352f | 729 | |
60b6c79c | 730 | end: |
fe9f7760 | 731 | return ret; |
60b6c79c MD |
732 | } |
733 | ||
2d85a600 | 734 | /* |
7567352f | 735 | * This is for debugging ONLY and should not be considered secure. |
2d85a600 MD |
736 | */ |
737 | static | |
fe9f7760 FD |
738 | int run_as_noworker(enum run_as_cmd cmd, |
739 | struct run_as_data *data, struct run_as_ret *ret_value, | |
740 | uid_t uid, gid_t gid) | |
2d85a600 | 741 | { |
df5b86c8 | 742 | int ret, saved_errno; |
5b73926f | 743 | mode_t old_mask; |
7567352f | 744 | run_as_fct fct; |
5b73926f | 745 | |
7567352f MD |
746 | fct = run_as_enum_to_fct(cmd); |
747 | if (!fct) { | |
748 | errno = -ENOSYS; | |
749 | ret = -1; | |
750 | goto end; | |
751 | } | |
5b73926f | 752 | old_mask = umask(0); |
fe9f7760 FD |
753 | ret = fct(data, ret_value); |
754 | saved_errno = ret_value->_errno; | |
5b73926f | 755 | umask(old_mask); |
df5b86c8 | 756 | errno = saved_errno; |
7567352f | 757 | end: |
5b73926f | 758 | return ret; |
2d85a600 MD |
759 | } |
760 | ||
761 | static | |
fe9f7760 | 762 | int run_as_restart_worker(struct run_as_worker *worker) |
2d85a600 | 763 | { |
fe9f7760 FD |
764 | int ret = 0; |
765 | char *procname = NULL; | |
766 | ||
767 | procname = worker->procname; | |
768 | ||
769 | /* Close socket to run_as worker process and clean up the zombie process */ | |
770 | run_as_destroy_worker(); | |
771 | ||
772 | /* Create a new run_as worker process*/ | |
773 | ret = run_as_create_worker(procname); | |
774 | if (ret < 0 ) { | |
775 | ERR("Restarting the worker process failed"); | |
776 | ret = -1; | |
777 | goto err; | |
778 | } | |
779 | err: | |
780 | return ret; | |
781 | } | |
782 | ||
783 | static | |
784 | int run_as(enum run_as_cmd cmd, struct run_as_data *data, | |
785 | struct run_as_ret *ret_value, uid_t uid, gid_t gid) | |
786 | { | |
787 | int ret, saved_errno; | |
7567352f | 788 | |
749b7a0c | 789 | if (use_clone()) { |
7567352f | 790 | DBG("Using run_as worker"); |
749b7a0c JG |
791 | pthread_mutex_lock(&worker_lock); |
792 | assert(global_worker); | |
749b7a0c | 793 | |
fe9f7760 FD |
794 | ret = run_as_cmd(global_worker, cmd, data, ret_value, uid, gid); |
795 | saved_errno = ret_value->_errno; | |
796 | ||
797 | pthread_mutex_unlock(&worker_lock); | |
798 | /* | |
799 | * If the worker thread crashed the errno is set to EIO. we log | |
800 | * the error and start a new worker process. | |
801 | */ | |
802 | if (ret == -1 && saved_errno == EIO) { | |
803 | DBG("Socket closed unexpectedly... " | |
804 | "Restarting the worker process"); | |
805 | ret = run_as_restart_worker(global_worker); | |
806 | ||
807 | if (ret == -1) { | |
808 | ERR("Failed to restart worker process."); | |
809 | goto err; | |
810 | } | |
811 | } | |
2d85a600 | 812 | } else { |
7567352f | 813 | DBG("Using run_as without worker"); |
fe9f7760 | 814 | ret = run_as_noworker(cmd, data, ret_value, uid, gid); |
2d85a600 | 815 | } |
fe9f7760 | 816 | err: |
7567352f | 817 | return ret; |
2d85a600 MD |
818 | } |
819 | ||
90e535ef | 820 | LTTNG_HIDDEN |
e11d277b | 821 | int run_as_mkdir_recursive(const char *path, mode_t mode, uid_t uid, gid_t gid) |
60b6c79c | 822 | { |
7567352f | 823 | struct run_as_data data; |
fe9f7760 | 824 | struct run_as_ret ret; |
60b6c79c | 825 | |
8446e5eb | 826 | memset(&data, 0, sizeof(data)); |
fe9f7760 | 827 | memset(&ret, 0, sizeof(ret)); |
60b6c79c | 828 | DBG3("mkdir() recursive %s with mode %d for uid %d and gid %d", |
08797918 | 829 | path, (int) mode, (int) uid, (int) gid); |
7567352f MD |
830 | strncpy(data.u.mkdir.path, path, PATH_MAX - 1); |
831 | data.u.mkdir.path[PATH_MAX - 1] = '\0'; | |
832 | data.u.mkdir.mode = mode; | |
fe9f7760 FD |
833 | |
834 | run_as(RUN_AS_MKDIR_RECURSIVE, &data, &ret, uid, gid); | |
835 | errno = ret._errno; | |
836 | return ret.u.mkdir.ret; | |
60b6c79c MD |
837 | } |
838 | ||
90e535ef | 839 | LTTNG_HIDDEN |
e11d277b | 840 | int run_as_mkdir(const char *path, mode_t mode, uid_t uid, gid_t gid) |
60b6c79c | 841 | { |
7567352f | 842 | struct run_as_data data; |
fe9f7760 | 843 | struct run_as_ret ret; |
60b6c79c | 844 | |
8446e5eb | 845 | memset(&data, 0, sizeof(data)); |
fe9f7760 FD |
846 | memset(&ret, 0, sizeof(ret)); |
847 | ||
60b6c79c | 848 | DBG3("mkdir() %s with mode %d for uid %d and gid %d", |
08797918 | 849 | path, (int) mode, (int) uid, (int) gid); |
7567352f MD |
850 | strncpy(data.u.mkdir.path, path, PATH_MAX - 1); |
851 | data.u.mkdir.path[PATH_MAX - 1] = '\0'; | |
852 | data.u.mkdir.mode = mode; | |
fe9f7760 FD |
853 | run_as(RUN_AS_MKDIR, &data, &ret, uid, gid); |
854 | errno = ret._errno; | |
855 | return ret.u.mkdir.ret; | |
60b6c79c MD |
856 | } |
857 | ||
90e535ef | 858 | LTTNG_HIDDEN |
e11d277b | 859 | int run_as_open(const char *path, int flags, mode_t mode, uid_t uid, gid_t gid) |
60b6c79c | 860 | { |
7567352f | 861 | struct run_as_data data; |
fe9f7760 | 862 | struct run_as_ret ret; |
c2b75c49 | 863 | |
8446e5eb | 864 | memset(&data, 0, sizeof(data)); |
fe9f7760 FD |
865 | memset(&ret, 0, sizeof(ret)); |
866 | ||
47fb7563 | 867 | DBG3("open() %s with flags %X mode %d for uid %d and gid %d", |
08797918 | 868 | path, flags, (int) mode, (int) uid, (int) gid); |
7567352f MD |
869 | strncpy(data.u.open.path, path, PATH_MAX - 1); |
870 | data.u.open.path[PATH_MAX - 1] = '\0'; | |
871 | data.u.open.flags = flags; | |
872 | data.u.open.mode = mode; | |
fe9f7760 FD |
873 | run_as(RUN_AS_OPEN, &data, &ret, uid, gid); |
874 | errno = ret._errno; | |
875 | ret.u.open.ret = ret.fd; | |
876 | return ret.u.open.ret; | |
60b6c79c | 877 | } |
4628484a MD |
878 | |
879 | LTTNG_HIDDEN | |
880 | int run_as_unlink(const char *path, uid_t uid, gid_t gid) | |
881 | { | |
7567352f | 882 | struct run_as_data data; |
fe9f7760 | 883 | struct run_as_ret ret; |
4628484a | 884 | |
8446e5eb | 885 | memset(&data, 0, sizeof(data)); |
fe9f7760 FD |
886 | memset(&ret, 0, sizeof(ret)); |
887 | ||
4628484a | 888 | DBG3("unlink() %s with for uid %d and gid %d", |
08797918 | 889 | path, (int) uid, (int) gid); |
7567352f MD |
890 | strncpy(data.u.unlink.path, path, PATH_MAX - 1); |
891 | data.u.unlink.path[PATH_MAX - 1] = '\0'; | |
fe9f7760 FD |
892 | run_as(RUN_AS_UNLINK, &data, &ret, uid, gid); |
893 | errno = ret._errno; | |
894 | return ret.u.unlink.ret; | |
4628484a MD |
895 | } |
896 | ||
897 | LTTNG_HIDDEN | |
7567352f | 898 | int run_as_rmdir_recursive(const char *path, uid_t uid, gid_t gid) |
4628484a | 899 | { |
7567352f | 900 | struct run_as_data data; |
fe9f7760 FD |
901 | struct run_as_ret ret; |
902 | ||
903 | memset(&data, 0, sizeof(data)); | |
904 | memset(&ret, 0, sizeof(ret)); | |
4628484a | 905 | |
7567352f | 906 | DBG3("rmdir_recursive() %s with for uid %d and gid %d", |
08797918 | 907 | path, (int) uid, (int) gid); |
7567352f MD |
908 | strncpy(data.u.rmdir_recursive.path, path, PATH_MAX - 1); |
909 | data.u.rmdir_recursive.path[PATH_MAX - 1] = '\0'; | |
fe9f7760 FD |
910 | run_as(RUN_AS_RMDIR_RECURSIVE, &data, &ret, uid, gid); |
911 | errno = ret._errno; | |
912 | return ret.u.rmdir_recursive.ret; | |
7567352f MD |
913 | } |
914 | ||
241e0a5a FD |
915 | LTTNG_HIDDEN |
916 | int run_as_extract_elf_symbol_offset(int fd, const char* function, | |
917 | uid_t uid, gid_t gid, uint64_t *offset) | |
918 | { | |
919 | struct run_as_data data; | |
920 | struct run_as_ret ret; | |
921 | ||
922 | DBG3("extract_elf_symbol_offset() on fd=%d and function=%s " | |
923 | "with for uid %d and gid %d", fd, function, (int) uid, (int) gid); | |
924 | ||
925 | data.fd = fd; | |
926 | ||
927 | strncpy(data.u.extract_elf_symbol_offset.function, function, LTTNG_SYMBOL_NAME_LEN - 1); | |
928 | ||
929 | data.u.extract_elf_symbol_offset.function[LTTNG_SYMBOL_NAME_LEN - 1] = '\0'; | |
930 | ||
931 | run_as(RUN_AS_EXTRACT_ELF_SYMBOL_OFFSET, &data, &ret, uid, gid); | |
932 | ||
933 | errno = ret._errno; | |
934 | ||
935 | if (ret._error) { | |
936 | return -1; | |
937 | } | |
938 | ||
939 | *offset = ret.u.extract_elf_symbol_offset.offset; | |
940 | return 0; | |
941 | } | |
942 | ||
0ef03255 FD |
943 | LTTNG_HIDDEN |
944 | int run_as_extract_sdt_probe_offsets(int fd, const char* provider_name, | |
945 | const char* probe_name, uid_t uid, gid_t gid, | |
946 | uint64_t **offsets, uint32_t *num_offset) | |
947 | { | |
948 | struct run_as_data data; | |
949 | struct run_as_ret ret; | |
950 | ||
951 | DBG3("extract_sdt_probe_offsets() on fd=%d, probe_name=%s and " | |
952 | "provider_name=%s with for uid %d and gid %d", fd, probe_name, | |
953 | provider_name, (int) uid, (int) gid); | |
954 | ||
955 | data.fd = fd; | |
956 | ||
957 | strncpy(data.u.extract_sdt_probe_offsets.probe_name, probe_name, LTTNG_SYMBOL_NAME_LEN - 1); | |
958 | strncpy(data.u.extract_sdt_probe_offsets.provider_name, provider_name, LTTNG_SYMBOL_NAME_LEN - 1); | |
959 | ||
960 | data.u.extract_sdt_probe_offsets.probe_name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0'; | |
961 | data.u.extract_sdt_probe_offsets.provider_name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0'; | |
962 | ||
963 | run_as(RUN_AS_EXTRACT_SDT_PROBE_OFFSETS, &data, &ret, uid, gid); | |
964 | ||
965 | errno = ret._errno; | |
966 | ||
967 | if (ret._error) { | |
968 | return -1; | |
969 | } | |
970 | ||
971 | *num_offset = ret.u.extract_sdt_probe_offsets.num_offset; | |
972 | ||
973 | *offsets = zmalloc(*num_offset * sizeof(uint64_t)); | |
974 | if (!*offsets) { | |
975 | return -ENOMEM; | |
976 | } | |
977 | ||
978 | memcpy(*offsets, ret.u.extract_sdt_probe_offsets.offsets, *num_offset * sizeof(uint64_t)); | |
979 | return 0; | |
980 | } | |
981 | ||
f8f66d38 | 982 | static |
a80ed305 | 983 | int reset_sighandler(void) |
f8f66d38 | 984 | { |
5b5bb8c8 | 985 | int sig; |
f8f66d38 | 986 | |
978d5d79 | 987 | DBG("Resetting run_as worker signal handlers to default"); |
5b5bb8c8 JG |
988 | for (sig = 1; sig <= 31; sig++) { |
989 | (void) signal(sig, SIG_DFL); | |
f8f66d38 | 990 | } |
5b5bb8c8 | 991 | return 0; |
a80ed305 JG |
992 | } |
993 | ||
994 | static | |
995 | void worker_sighandler(int sig) | |
996 | { | |
997 | const char *signame; | |
998 | ||
999 | /* | |
cd89f030 JG |
1000 | * The worker will inherit its parent's signals since they are part of |
1001 | * the same process group. However, in the case of SIGINT and SIGTERM, | |
1002 | * we want to give the worker a chance to teardown gracefully when its | |
1003 | * parent closes the command socket. | |
a80ed305 JG |
1004 | */ |
1005 | switch (sig) { | |
1006 | case SIGINT: | |
1007 | signame = "SIGINT"; | |
1008 | break; | |
1009 | case SIGTERM: | |
1010 | signame = "SIGTERM"; | |
1011 | break; | |
1012 | default: | |
22d5e48e | 1013 | signame = NULL; |
a80ed305 JG |
1014 | } |
1015 | ||
22d5e48e JG |
1016 | if (signame) { |
1017 | DBG("run_as worker received signal %s", signame); | |
1018 | } else { | |
1019 | DBG("run_as_worker received signal %d", sig); | |
1020 | } | |
a80ed305 JG |
1021 | } |
1022 | ||
1023 | static | |
1024 | int set_worker_sighandlers(void) | |
1025 | { | |
1026 | int ret = 0; | |
1027 | sigset_t sigset; | |
1028 | struct sigaction sa; | |
1029 | ||
1030 | if ((ret = sigemptyset(&sigset)) < 0) { | |
1031 | PERROR("sigemptyset"); | |
1032 | goto end; | |
1033 | } | |
1034 | ||
1035 | sa.sa_handler = worker_sighandler; | |
1036 | sa.sa_mask = sigset; | |
1037 | sa.sa_flags = 0; | |
1038 | if ((ret = sigaction(SIGINT, &sa, NULL)) < 0) { | |
1039 | PERROR("sigaction SIGINT"); | |
1040 | goto end; | |
1041 | } | |
1042 | ||
1043 | if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) { | |
1044 | PERROR("sigaction SIGTERM"); | |
1045 | goto end; | |
1046 | } | |
1047 | ||
1048 | DBG("run_as signal handler set for SIGTERM and SIGINT"); | |
1049 | end: | |
1050 | return ret; | |
f8f66d38 JG |
1051 | } |
1052 | ||
7567352f MD |
1053 | LTTNG_HIDDEN |
1054 | int run_as_create_worker(char *procname) | |
1055 | { | |
1056 | pid_t pid; | |
1057 | int i, ret = 0; | |
1058 | ssize_t readlen; | |
1059 | struct run_as_ret recvret; | |
1060 | struct run_as_worker *worker; | |
1061 | ||
749b7a0c JG |
1062 | pthread_mutex_lock(&worker_lock); |
1063 | assert(!global_worker); | |
7567352f | 1064 | if (!use_clone()) { |
749b7a0c JG |
1065 | /* |
1066 | * Don't initialize a worker, all run_as tasks will be performed | |
1067 | * in the current process. | |
1068 | */ | |
7567352f MD |
1069 | ret = 0; |
1070 | goto end; | |
1071 | } | |
1072 | worker = zmalloc(sizeof(*worker)); | |
1073 | if (!worker) { | |
1074 | ret = -ENOMEM; | |
1075 | goto end; | |
1076 | } | |
1077 | worker->procname = procname; | |
1078 | /* Create unix socket. */ | |
1079 | if (lttcomm_create_anon_unix_socketpair(worker->sockpair) < 0) { | |
1080 | ret = -1; | |
1081 | goto error_sock; | |
1082 | } | |
fe9f7760 | 1083 | |
7567352f MD |
1084 | /* Fork worker. */ |
1085 | pid = fork(); | |
1086 | if (pid < 0) { | |
1087 | PERROR("fork"); | |
1088 | ret = -1; | |
1089 | goto error_fork; | |
1090 | } else if (pid == 0) { | |
1091 | /* Child */ | |
1092 | ||
f8f66d38 JG |
1093 | reset_sighandler(); |
1094 | ||
a80ed305 JG |
1095 | set_worker_sighandlers(); |
1096 | ||
749b7a0c JG |
1097 | /* The child has no use for this lock. */ |
1098 | pthread_mutex_unlock(&worker_lock); | |
7567352f MD |
1099 | /* Just close, no shutdown. */ |
1100 | if (close(worker->sockpair[0])) { | |
1101 | PERROR("close"); | |
1102 | exit(EXIT_FAILURE); | |
1103 | } | |
fe9f7760 FD |
1104 | |
1105 | /* | |
1106 | * Close all FDs aside from STDIN, STDOUT, STDERR and sockpair[1] | |
1107 | * Sockpair[1] is used as a control channel with the master | |
1108 | */ | |
1109 | for (i = 3; i < sysconf(_SC_OPEN_MAX); i++) { | |
1110 | if (i != worker->sockpair[1]) { | |
1111 | (void) close(i); | |
1112 | } | |
1113 | } | |
1114 | ||
7567352f MD |
1115 | worker->sockpair[0] = -1; |
1116 | ret = run_as_worker(worker); | |
1117 | if (lttcomm_close_unix_sock(worker->sockpair[1])) { | |
1118 | PERROR("close"); | |
1119 | ret = -1; | |
1120 | } | |
1121 | worker->sockpair[1] = -1; | |
978d5d79 | 1122 | LOG(ret ? PRINT_ERR : PRINT_DBG, "run_as worker exiting (ret = %d)", ret); |
7567352f MD |
1123 | exit(ret ? EXIT_FAILURE : EXIT_SUCCESS); |
1124 | } else { | |
1125 | /* Parent */ | |
1126 | ||
1127 | /* Just close, no shutdown. */ | |
1128 | if (close(worker->sockpair[1])) { | |
1129 | PERROR("close"); | |
1130 | ret = -1; | |
1131 | goto error_fork; | |
1132 | } | |
1133 | worker->sockpair[1] = -1; | |
1134 | worker->pid = pid; | |
1135 | /* Wait for worker to become ready. */ | |
1136 | readlen = lttcomm_recv_unix_sock(worker->sockpair[0], | |
1137 | &recvret, sizeof(recvret)); | |
1138 | if (readlen < sizeof(recvret)) { | |
1139 | ERR("readlen: %zd", readlen); | |
1140 | PERROR("Error reading response from run_as at creation"); | |
1141 | ret = -1; | |
1142 | goto error_fork; | |
1143 | } | |
1144 | global_worker = worker; | |
1145 | } | |
1146 | end: | |
749b7a0c | 1147 | pthread_mutex_unlock(&worker_lock); |
7567352f MD |
1148 | return ret; |
1149 | ||
1150 | /* Error handling. */ | |
1151 | error_fork: | |
1152 | for (i = 0; i < 2; i++) { | |
1153 | if (worker->sockpair[i] < 0) { | |
1154 | continue; | |
1155 | } | |
1156 | if (lttcomm_close_unix_sock(worker->sockpair[i])) { | |
1157 | PERROR("close"); | |
1158 | } | |
1159 | worker->sockpair[i] = -1; | |
1160 | } | |
1161 | error_sock: | |
1162 | free(worker); | |
749b7a0c | 1163 | pthread_mutex_unlock(&worker_lock); |
7567352f MD |
1164 | return ret; |
1165 | } | |
1166 | ||
1167 | LTTNG_HIDDEN | |
1168 | void run_as_destroy_worker(void) | |
1169 | { | |
1170 | struct run_as_worker *worker = global_worker; | |
7567352f | 1171 | |
978d5d79 | 1172 | DBG("Destroying run_as worker"); |
749b7a0c | 1173 | pthread_mutex_lock(&worker_lock); |
7567352f | 1174 | if (!worker) { |
749b7a0c | 1175 | goto end; |
7567352f MD |
1176 | } |
1177 | /* Close unix socket */ | |
978d5d79 | 1178 | DBG("Closing run_as worker socket"); |
7567352f MD |
1179 | if (lttcomm_close_unix_sock(worker->sockpair[0])) { |
1180 | PERROR("close"); | |
1181 | } | |
1182 | worker->sockpair[0] = -1; | |
1183 | /* Wait for worker. */ | |
f8f66d38 JG |
1184 | for (;;) { |
1185 | int status; | |
1186 | pid_t wait_ret; | |
1187 | ||
1188 | wait_ret = waitpid(worker->pid, &status, 0); | |
1189 | if (wait_ret < 0) { | |
1190 | if (errno == EINTR) { | |
1191 | continue; | |
1192 | } | |
1193 | PERROR("waitpid"); | |
1194 | break; | |
1195 | } | |
1196 | ||
1197 | if (WIFEXITED(status)) { | |
1198 | LOG(WEXITSTATUS(status) == 0 ? PRINT_DBG : PRINT_ERR, | |
1199 | DEFAULT_RUN_AS_WORKER_NAME " terminated with status code %d", | |
1200 | WEXITSTATUS(status)); | |
1201 | break; | |
1202 | } else if (WIFSIGNALED(status)) { | |
1203 | ERR(DEFAULT_RUN_AS_WORKER_NAME " was killed by signal %d", | |
1204 | WTERMSIG(status)); | |
1205 | break; | |
1206 | } | |
7567352f MD |
1207 | } |
1208 | free(worker); | |
1209 | global_worker = NULL; | |
749b7a0c JG |
1210 | end: |
1211 | pthread_mutex_unlock(&worker_lock); | |
4628484a | 1212 | } |