Commit | Line | Data |
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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 | ||
eb95dccf JG |
405 | if (fd < 0) { |
406 | goto end; | |
407 | } | |
fe9f7760 FD |
408 | ret_close = close(fd); |
409 | if (ret_close < 0) { | |
410 | PERROR("close"); | |
411 | } | |
eb95dccf | 412 | end: |
fe9f7760 FD |
413 | return ret; |
414 | } | |
415 | ||
416 | static | |
417 | int recv_fd_from_worker(struct run_as_worker *worker, enum run_as_cmd cmd, int *fd) | |
418 | { | |
419 | int ret = 0; | |
420 | ||
421 | switch (cmd) { | |
422 | case RUN_AS_OPEN: | |
423 | break; | |
424 | default: | |
425 | return 0; | |
426 | } | |
427 | ||
428 | ret = do_recv_fd(worker->sockpair[0], fd); | |
429 | if (ret < 0) { | |
430 | PERROR("do_recv_fd error"); | |
431 | ret = -1; | |
432 | } | |
433 | ||
434 | return ret; | |
435 | } | |
436 | ||
437 | static | |
438 | int recv_fd_from_master(struct run_as_worker *worker, enum run_as_cmd cmd, int *fd) | |
439 | { | |
440 | int ret = 0; | |
441 | ||
442 | switch (cmd) { | |
241e0a5a | 443 | case RUN_AS_EXTRACT_ELF_SYMBOL_OFFSET: |
0ef03255 | 444 | case RUN_AS_EXTRACT_SDT_PROBE_OFFSETS: |
241e0a5a | 445 | break; |
fe9f7760 FD |
446 | default: |
447 | return 0; | |
448 | } | |
449 | ||
450 | ret = do_recv_fd(worker->sockpair[1], fd); | |
451 | if (ret < 0) { | |
452 | PERROR("do_recv_fd error"); | |
453 | ret = -1; | |
454 | } | |
455 | ||
456 | return ret; | |
457 | } | |
458 | ||
459 | static | |
460 | int cleanup_received_fd(enum run_as_cmd cmd, int fd) | |
461 | { | |
462 | int ret = 0; | |
463 | ||
464 | switch (cmd) { | |
241e0a5a | 465 | case RUN_AS_EXTRACT_ELF_SYMBOL_OFFSET: |
0ef03255 | 466 | case RUN_AS_EXTRACT_SDT_PROBE_OFFSETS: |
241e0a5a | 467 | break; |
fe9f7760 FD |
468 | default: |
469 | return 0; | |
470 | } | |
471 | ||
9abb7e4a JG |
472 | if (fd < 0) { |
473 | return 0; | |
474 | } | |
fe9f7760 FD |
475 | ret = close(fd); |
476 | if (ret < 0) { | |
477 | PERROR("close error"); | |
478 | ret = -1; | |
479 | } | |
480 | ||
481 | return ret; | |
482 | } | |
0ef03255 | 483 | |
7567352f MD |
484 | /* |
485 | * Return < 0 on error, 0 if OK, 1 on hangup. | |
486 | */ | |
c2b75c49 | 487 | static |
7567352f | 488 | int handle_one_cmd(struct run_as_worker *worker) |
c2b75c49 | 489 | { |
7567352f MD |
490 | int ret = 0; |
491 | struct run_as_data data; | |
492 | ssize_t readlen, writelen; | |
df5b86c8 | 493 | struct run_as_ret sendret; |
7567352f MD |
494 | run_as_fct cmd; |
495 | uid_t prev_euid; | |
496 | ||
ee5fcf1d JG |
497 | memset(&sendret, 0, sizeof(sendret)); |
498 | sendret.fd = -1; | |
499 | ||
fe9f7760 FD |
500 | /* |
501 | * Stage 1: Receive run_as_data struct from the master. | |
502 | * The structure contains the command type and all the parameters needed for | |
503 | * its execution | |
504 | */ | |
7567352f MD |
505 | readlen = lttcomm_recv_unix_sock(worker->sockpair[1], &data, |
506 | sizeof(data)); | |
507 | if (readlen == 0) { | |
508 | /* hang up */ | |
509 | ret = 1; | |
510 | goto end; | |
511 | } | |
512 | if (readlen < sizeof(data)) { | |
513 | PERROR("lttcomm_recv_unix_sock error"); | |
514 | ret = -1; | |
515 | goto end; | |
516 | } | |
c2b75c49 | 517 | |
7567352f MD |
518 | cmd = run_as_enum_to_fct(data.cmd); |
519 | if (!cmd) { | |
520 | ret = -1; | |
521 | goto end; | |
522 | } | |
523 | ||
fe9f7760 FD |
524 | /* |
525 | * Stage 2: Receive file descriptor from master. | |
526 | * Some commands need a file descriptor as input so if it's needed we | |
527 | * receive the fd using the Unix socket. | |
528 | */ | |
529 | ret = recv_fd_from_master(worker, data.cmd, &data.fd); | |
530 | if (ret < 0) { | |
531 | PERROR("recv_fd_from_master error"); | |
532 | ret = -1; | |
533 | goto end; | |
534 | } | |
535 | ||
7567352f MD |
536 | prev_euid = getuid(); |
537 | if (data.gid != getegid()) { | |
538 | ret = setegid(data.gid); | |
1576d582 | 539 | if (ret < 0) { |
561f5f2c JG |
540 | sendret._error = true; |
541 | sendret._errno = errno; | |
4c462e79 | 542 | PERROR("setegid"); |
6d73c4ef | 543 | goto write_return; |
1576d582 | 544 | } |
c2b75c49 | 545 | } |
7567352f MD |
546 | if (data.uid != prev_euid) { |
547 | ret = seteuid(data.uid); | |
1576d582 | 548 | if (ret < 0) { |
561f5f2c JG |
549 | sendret._error = true; |
550 | sendret._errno = errno; | |
4c462e79 | 551 | PERROR("seteuid"); |
6d73c4ef | 552 | goto write_return; |
1576d582 | 553 | } |
c2b75c49 | 554 | } |
fe9f7760 | 555 | |
c2b75c49 MD |
556 | /* |
557 | * Also set umask to 0 for mkdir executable bit. | |
558 | */ | |
559 | umask(0); | |
fe9f7760 FD |
560 | |
561 | /* | |
562 | * Stage 3: Execute the command | |
563 | */ | |
564 | ret = (*cmd)(&data, &sendret); | |
565 | if (ret < 0) { | |
566 | DBG("Execution of command returned an error"); | |
567 | } | |
6d73c4ef MD |
568 | |
569 | write_return: | |
fe9f7760 FD |
570 | ret = cleanup_received_fd(data.cmd, data.fd); |
571 | if (ret < 0) { | |
572 | ERR("Error cleaning up FD"); | |
573 | goto end; | |
574 | } | |
575 | ||
576 | /* | |
577 | * Stage 4: Send run_as_ret structure to the master. | |
578 | * This structure contain the return value of the command and the errno. | |
579 | */ | |
7567352f MD |
580 | writelen = lttcomm_send_unix_sock(worker->sockpair[1], &sendret, |
581 | sizeof(sendret)); | |
6cd525e8 | 582 | if (writelen < sizeof(sendret)) { |
7567352f MD |
583 | PERROR("lttcomm_send_unix_sock error"); |
584 | ret = -1; | |
585 | goto end; | |
586 | } | |
fe9f7760 FD |
587 | |
588 | /* | |
589 | * Stage 5: Send file descriptor to the master | |
590 | * Some commands return a file descriptor so if it's needed we pass it back | |
591 | * to the master using the Unix socket. | |
592 | */ | |
593 | ret = send_fd_to_master(worker, data.cmd, sendret.fd); | |
594 | if (ret < 0) { | |
595 | DBG("Sending FD to master returned an error"); | |
7567352f MD |
596 | goto end; |
597 | } | |
fe9f7760 | 598 | |
7567352f MD |
599 | if (seteuid(prev_euid) < 0) { |
600 | PERROR("seteuid"); | |
601 | ret = -1; | |
602 | goto end; | |
603 | } | |
604 | ret = 0; | |
605 | end: | |
606 | return ret; | |
607 | } | |
608 | ||
609 | static | |
610 | int run_as_worker(struct run_as_worker *worker) | |
611 | { | |
612 | int ret; | |
613 | ssize_t writelen; | |
614 | struct run_as_ret sendret; | |
615 | size_t proc_orig_len; | |
616 | ||
617 | /* | |
618 | * Initialize worker. Set a different process cmdline. | |
619 | */ | |
620 | proc_orig_len = strlen(worker->procname); | |
621 | memset(worker->procname, 0, proc_orig_len); | |
622 | strncpy(worker->procname, DEFAULT_RUN_AS_WORKER_NAME, proc_orig_len); | |
623 | ||
e1055edb JG |
624 | ret = lttng_prctl(PR_SET_NAME, |
625 | (unsigned long) DEFAULT_RUN_AS_WORKER_NAME, 0, 0, 0); | |
626 | if (ret && ret != -ENOSYS) { | |
b8090274 JG |
627 | /* Don't fail as this is not essential. */ |
628 | PERROR("prctl PR_SET_NAME"); | |
6cd525e8 | 629 | } |
7567352f | 630 | |
fe9f7760 FD |
631 | memset(&sendret, 0, sizeof(sendret)); |
632 | ||
7567352f MD |
633 | writelen = lttcomm_send_unix_sock(worker->sockpair[1], &sendret, |
634 | sizeof(sendret)); | |
635 | if (writelen < sizeof(sendret)) { | |
636 | PERROR("lttcomm_send_unix_sock error"); | |
637 | ret = EXIT_FAILURE; | |
638 | goto end; | |
639 | } | |
640 | ||
641 | for (;;) { | |
642 | ret = handle_one_cmd(worker); | |
643 | if (ret < 0) { | |
644 | ret = EXIT_FAILURE; | |
645 | goto end; | |
646 | } else if (ret > 0) { | |
647 | break; | |
648 | } else { | |
649 | continue; /* Next command. */ | |
650 | } | |
651 | } | |
652 | ret = EXIT_SUCCESS; | |
653 | end: | |
654 | return ret; | |
c2b75c49 MD |
655 | } |
656 | ||
60b6c79c | 657 | static |
7567352f MD |
658 | int run_as_cmd(struct run_as_worker *worker, |
659 | enum run_as_cmd cmd, | |
660 | struct run_as_data *data, | |
fe9f7760 | 661 | struct run_as_ret *ret_value, |
7567352f | 662 | uid_t uid, gid_t gid) |
60b6c79c | 663 | { |
fe9f7760 | 664 | int ret = 0; |
7567352f | 665 | ssize_t readlen, writelen; |
60b6c79c MD |
666 | |
667 | /* | |
668 | * If we are non-root, we can only deal with our own uid. | |
669 | */ | |
670 | if (geteuid() != 0) { | |
671 | if (uid != geteuid()) { | |
fe9f7760 FD |
672 | ret = -1; |
673 | ret_value->_errno = EPERM; | |
60b6c79c | 674 | ERR("Client (%d)/Server (%d) UID mismatch (and sessiond is not root)", |
08797918 | 675 | (int) uid, (int) geteuid()); |
df5b86c8 | 676 | goto end; |
60b6c79c | 677 | } |
60b6c79c MD |
678 | } |
679 | ||
7567352f MD |
680 | data->cmd = cmd; |
681 | data->uid = uid; | |
682 | data->gid = gid; | |
683 | ||
fe9f7760 FD |
684 | /* |
685 | * Stage 1: Send the run_as_data struct to the worker process | |
686 | */ | |
7567352f MD |
687 | writelen = lttcomm_send_unix_sock(worker->sockpair[0], data, |
688 | sizeof(*data)); | |
689 | if (writelen < sizeof(*data)) { | |
690 | PERROR("Error writing message to run_as"); | |
fe9f7760 FD |
691 | ret = -1; |
692 | ret_value->_errno = EIO; | |
60b6c79c | 693 | goto end; |
c2b75c49 | 694 | } |
7567352f | 695 | |
fe9f7760 FD |
696 | /* |
697 | * Stage 2: Send file descriptor to the worker process if needed | |
698 | */ | |
699 | ret = send_fd_to_worker(worker, data->cmd, data->fd); | |
700 | if (ret) { | |
701 | PERROR("do_send_fd error"); | |
702 | ret = -1; | |
703 | ret_value->_errno = EIO; | |
704 | goto end; | |
705 | } | |
706 | ||
707 | /* | |
708 | * Stage 3: Wait for the execution of the command | |
709 | */ | |
710 | ||
711 | /* | |
712 | * Stage 4: Receive the run_as_ret struct containing the return value and | |
713 | * errno | |
714 | */ | |
715 | readlen = lttcomm_recv_unix_sock(worker->sockpair[0], ret_value, | |
716 | sizeof(*ret_value)); | |
da9ee832 JG |
717 | if (!readlen) { |
718 | ERR("Run-as worker has hung-up during run_as_cmd"); | |
fe9f7760 FD |
719 | ret = -1; |
720 | ret_value->_errno = EIO; | |
da9ee832 | 721 | goto end; |
fe9f7760 | 722 | } else if (readlen < sizeof(*ret_value)) { |
7567352f | 723 | PERROR("Error reading response from run_as"); |
fe9f7760 FD |
724 | ret = -1; |
725 | ret_value->_errno = errno; | |
033b58a7 | 726 | goto end; |
6cd525e8 | 727 | } |
fe9f7760 FD |
728 | |
729 | /* | |
730 | * Stage 5: Receive file descriptor if needed | |
731 | */ | |
732 | ret = recv_fd_from_worker(worker, data->cmd, &ret_value->fd); | |
733 | if (ret < 0) { | |
734 | ERR("Error receiving fd"); | |
735 | ret = -1; | |
736 | ret_value->_errno = EIO; | |
4c462e79 | 737 | } |
7567352f | 738 | |
60b6c79c | 739 | end: |
fe9f7760 | 740 | return ret; |
60b6c79c MD |
741 | } |
742 | ||
2d85a600 | 743 | /* |
7567352f | 744 | * This is for debugging ONLY and should not be considered secure. |
2d85a600 MD |
745 | */ |
746 | static | |
fe9f7760 FD |
747 | int run_as_noworker(enum run_as_cmd cmd, |
748 | struct run_as_data *data, struct run_as_ret *ret_value, | |
749 | uid_t uid, gid_t gid) | |
2d85a600 | 750 | { |
df5b86c8 | 751 | int ret, saved_errno; |
5b73926f | 752 | mode_t old_mask; |
7567352f | 753 | run_as_fct fct; |
5b73926f | 754 | |
7567352f MD |
755 | fct = run_as_enum_to_fct(cmd); |
756 | if (!fct) { | |
757 | errno = -ENOSYS; | |
758 | ret = -1; | |
759 | goto end; | |
760 | } | |
5b73926f | 761 | old_mask = umask(0); |
fe9f7760 FD |
762 | ret = fct(data, ret_value); |
763 | saved_errno = ret_value->_errno; | |
5b73926f | 764 | umask(old_mask); |
df5b86c8 | 765 | errno = saved_errno; |
7567352f | 766 | end: |
5b73926f | 767 | return ret; |
2d85a600 MD |
768 | } |
769 | ||
770 | static | |
fe9f7760 | 771 | int run_as_restart_worker(struct run_as_worker *worker) |
2d85a600 | 772 | { |
fe9f7760 FD |
773 | int ret = 0; |
774 | char *procname = NULL; | |
775 | ||
776 | procname = worker->procname; | |
777 | ||
778 | /* Close socket to run_as worker process and clean up the zombie process */ | |
779 | run_as_destroy_worker(); | |
780 | ||
781 | /* Create a new run_as worker process*/ | |
782 | ret = run_as_create_worker(procname); | |
783 | if (ret < 0 ) { | |
784 | ERR("Restarting the worker process failed"); | |
785 | ret = -1; | |
786 | goto err; | |
787 | } | |
788 | err: | |
789 | return ret; | |
790 | } | |
791 | ||
792 | static | |
793 | int run_as(enum run_as_cmd cmd, struct run_as_data *data, | |
794 | struct run_as_ret *ret_value, uid_t uid, gid_t gid) | |
795 | { | |
796 | int ret, saved_errno; | |
7567352f | 797 | |
749b7a0c | 798 | if (use_clone()) { |
7567352f | 799 | DBG("Using run_as worker"); |
749b7a0c JG |
800 | pthread_mutex_lock(&worker_lock); |
801 | assert(global_worker); | |
749b7a0c | 802 | |
fe9f7760 FD |
803 | ret = run_as_cmd(global_worker, cmd, data, ret_value, uid, gid); |
804 | saved_errno = ret_value->_errno; | |
805 | ||
806 | pthread_mutex_unlock(&worker_lock); | |
807 | /* | |
808 | * If the worker thread crashed the errno is set to EIO. we log | |
809 | * the error and start a new worker process. | |
810 | */ | |
811 | if (ret == -1 && saved_errno == EIO) { | |
812 | DBG("Socket closed unexpectedly... " | |
813 | "Restarting the worker process"); | |
814 | ret = run_as_restart_worker(global_worker); | |
815 | ||
816 | if (ret == -1) { | |
817 | ERR("Failed to restart worker process."); | |
818 | goto err; | |
819 | } | |
820 | } | |
2d85a600 | 821 | } else { |
7567352f | 822 | DBG("Using run_as without worker"); |
fe9f7760 | 823 | ret = run_as_noworker(cmd, data, ret_value, uid, gid); |
2d85a600 | 824 | } |
fe9f7760 | 825 | err: |
7567352f | 826 | return ret; |
2d85a600 MD |
827 | } |
828 | ||
90e535ef | 829 | LTTNG_HIDDEN |
e11d277b | 830 | int run_as_mkdir_recursive(const char *path, mode_t mode, uid_t uid, gid_t gid) |
60b6c79c | 831 | { |
7567352f | 832 | struct run_as_data data; |
fe9f7760 | 833 | struct run_as_ret ret; |
60b6c79c | 834 | |
8446e5eb | 835 | memset(&data, 0, sizeof(data)); |
fe9f7760 | 836 | memset(&ret, 0, sizeof(ret)); |
60b6c79c | 837 | DBG3("mkdir() recursive %s with mode %d for uid %d and gid %d", |
08797918 | 838 | path, (int) mode, (int) uid, (int) gid); |
7567352f MD |
839 | strncpy(data.u.mkdir.path, path, PATH_MAX - 1); |
840 | data.u.mkdir.path[PATH_MAX - 1] = '\0'; | |
841 | data.u.mkdir.mode = mode; | |
fe9f7760 FD |
842 | |
843 | run_as(RUN_AS_MKDIR_RECURSIVE, &data, &ret, uid, gid); | |
844 | errno = ret._errno; | |
845 | return ret.u.mkdir.ret; | |
60b6c79c MD |
846 | } |
847 | ||
90e535ef | 848 | LTTNG_HIDDEN |
e11d277b | 849 | int run_as_mkdir(const char *path, mode_t mode, uid_t uid, gid_t gid) |
60b6c79c | 850 | { |
7567352f | 851 | struct run_as_data data; |
fe9f7760 | 852 | struct run_as_ret ret; |
60b6c79c | 853 | |
8446e5eb | 854 | memset(&data, 0, sizeof(data)); |
fe9f7760 FD |
855 | memset(&ret, 0, sizeof(ret)); |
856 | ||
60b6c79c | 857 | DBG3("mkdir() %s with mode %d for uid %d and gid %d", |
08797918 | 858 | path, (int) mode, (int) uid, (int) gid); |
7567352f MD |
859 | strncpy(data.u.mkdir.path, path, PATH_MAX - 1); |
860 | data.u.mkdir.path[PATH_MAX - 1] = '\0'; | |
861 | data.u.mkdir.mode = mode; | |
fe9f7760 FD |
862 | run_as(RUN_AS_MKDIR, &data, &ret, uid, gid); |
863 | errno = ret._errno; | |
864 | return ret.u.mkdir.ret; | |
60b6c79c MD |
865 | } |
866 | ||
90e535ef | 867 | LTTNG_HIDDEN |
e11d277b | 868 | int run_as_open(const char *path, int flags, mode_t mode, uid_t uid, gid_t gid) |
60b6c79c | 869 | { |
7567352f | 870 | struct run_as_data data; |
fe9f7760 | 871 | struct run_as_ret ret; |
c2b75c49 | 872 | |
8446e5eb | 873 | memset(&data, 0, sizeof(data)); |
fe9f7760 FD |
874 | memset(&ret, 0, sizeof(ret)); |
875 | ||
47fb7563 | 876 | DBG3("open() %s with flags %X mode %d for uid %d and gid %d", |
08797918 | 877 | path, flags, (int) mode, (int) uid, (int) gid); |
7567352f MD |
878 | strncpy(data.u.open.path, path, PATH_MAX - 1); |
879 | data.u.open.path[PATH_MAX - 1] = '\0'; | |
880 | data.u.open.flags = flags; | |
881 | data.u.open.mode = mode; | |
fe9f7760 FD |
882 | run_as(RUN_AS_OPEN, &data, &ret, uid, gid); |
883 | errno = ret._errno; | |
884 | ret.u.open.ret = ret.fd; | |
885 | return ret.u.open.ret; | |
60b6c79c | 886 | } |
4628484a MD |
887 | |
888 | LTTNG_HIDDEN | |
889 | int run_as_unlink(const char *path, uid_t uid, gid_t gid) | |
890 | { | |
7567352f | 891 | struct run_as_data data; |
fe9f7760 | 892 | struct run_as_ret ret; |
4628484a | 893 | |
8446e5eb | 894 | memset(&data, 0, sizeof(data)); |
fe9f7760 FD |
895 | memset(&ret, 0, sizeof(ret)); |
896 | ||
4628484a | 897 | DBG3("unlink() %s with for uid %d and gid %d", |
08797918 | 898 | path, (int) uid, (int) gid); |
7567352f MD |
899 | strncpy(data.u.unlink.path, path, PATH_MAX - 1); |
900 | data.u.unlink.path[PATH_MAX - 1] = '\0'; | |
fe9f7760 FD |
901 | run_as(RUN_AS_UNLINK, &data, &ret, uid, gid); |
902 | errno = ret._errno; | |
903 | return ret.u.unlink.ret; | |
4628484a MD |
904 | } |
905 | ||
906 | LTTNG_HIDDEN | |
7567352f | 907 | int run_as_rmdir_recursive(const char *path, uid_t uid, gid_t gid) |
4628484a | 908 | { |
7567352f | 909 | struct run_as_data data; |
fe9f7760 FD |
910 | struct run_as_ret ret; |
911 | ||
912 | memset(&data, 0, sizeof(data)); | |
913 | memset(&ret, 0, sizeof(ret)); | |
4628484a | 914 | |
7567352f | 915 | DBG3("rmdir_recursive() %s with for uid %d and gid %d", |
08797918 | 916 | path, (int) uid, (int) gid); |
7567352f MD |
917 | strncpy(data.u.rmdir_recursive.path, path, PATH_MAX - 1); |
918 | data.u.rmdir_recursive.path[PATH_MAX - 1] = '\0'; | |
fe9f7760 FD |
919 | run_as(RUN_AS_RMDIR_RECURSIVE, &data, &ret, uid, gid); |
920 | errno = ret._errno; | |
921 | return ret.u.rmdir_recursive.ret; | |
7567352f MD |
922 | } |
923 | ||
241e0a5a FD |
924 | LTTNG_HIDDEN |
925 | int run_as_extract_elf_symbol_offset(int fd, const char* function, | |
926 | uid_t uid, gid_t gid, uint64_t *offset) | |
927 | { | |
928 | struct run_as_data data; | |
929 | struct run_as_ret ret; | |
930 | ||
f726677b JG |
931 | memset(&data, 0, sizeof(data)); |
932 | memset(&ret, 0, sizeof(ret)); | |
933 | ||
241e0a5a FD |
934 | DBG3("extract_elf_symbol_offset() on fd=%d and function=%s " |
935 | "with for uid %d and gid %d", fd, function, (int) uid, (int) gid); | |
936 | ||
937 | data.fd = fd; | |
938 | ||
939 | strncpy(data.u.extract_elf_symbol_offset.function, function, LTTNG_SYMBOL_NAME_LEN - 1); | |
940 | ||
941 | data.u.extract_elf_symbol_offset.function[LTTNG_SYMBOL_NAME_LEN - 1] = '\0'; | |
942 | ||
943 | run_as(RUN_AS_EXTRACT_ELF_SYMBOL_OFFSET, &data, &ret, uid, gid); | |
944 | ||
945 | errno = ret._errno; | |
946 | ||
947 | if (ret._error) { | |
948 | return -1; | |
949 | } | |
950 | ||
951 | *offset = ret.u.extract_elf_symbol_offset.offset; | |
952 | return 0; | |
953 | } | |
954 | ||
0ef03255 FD |
955 | LTTNG_HIDDEN |
956 | int run_as_extract_sdt_probe_offsets(int fd, const char* provider_name, | |
957 | const char* probe_name, uid_t uid, gid_t gid, | |
958 | uint64_t **offsets, uint32_t *num_offset) | |
959 | { | |
960 | struct run_as_data data; | |
961 | struct run_as_ret ret; | |
962 | ||
f726677b JG |
963 | memset(&data, 0, sizeof(data)); |
964 | memset(&ret, 0, sizeof(ret)); | |
965 | ||
0ef03255 FD |
966 | DBG3("extract_sdt_probe_offsets() on fd=%d, probe_name=%s and " |
967 | "provider_name=%s with for uid %d and gid %d", fd, probe_name, | |
968 | provider_name, (int) uid, (int) gid); | |
969 | ||
970 | data.fd = fd; | |
971 | ||
972 | strncpy(data.u.extract_sdt_probe_offsets.probe_name, probe_name, LTTNG_SYMBOL_NAME_LEN - 1); | |
973 | strncpy(data.u.extract_sdt_probe_offsets.provider_name, provider_name, LTTNG_SYMBOL_NAME_LEN - 1); | |
974 | ||
975 | data.u.extract_sdt_probe_offsets.probe_name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0'; | |
976 | data.u.extract_sdt_probe_offsets.provider_name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0'; | |
977 | ||
978 | run_as(RUN_AS_EXTRACT_SDT_PROBE_OFFSETS, &data, &ret, uid, gid); | |
979 | ||
980 | errno = ret._errno; | |
981 | ||
982 | if (ret._error) { | |
983 | return -1; | |
984 | } | |
985 | ||
986 | *num_offset = ret.u.extract_sdt_probe_offsets.num_offset; | |
987 | ||
988 | *offsets = zmalloc(*num_offset * sizeof(uint64_t)); | |
989 | if (!*offsets) { | |
990 | return -ENOMEM; | |
991 | } | |
992 | ||
993 | memcpy(*offsets, ret.u.extract_sdt_probe_offsets.offsets, *num_offset * sizeof(uint64_t)); | |
994 | return 0; | |
995 | } | |
996 | ||
f8f66d38 | 997 | static |
a80ed305 | 998 | int reset_sighandler(void) |
f8f66d38 | 999 | { |
5b5bb8c8 | 1000 | int sig; |
f8f66d38 | 1001 | |
978d5d79 | 1002 | DBG("Resetting run_as worker signal handlers to default"); |
5b5bb8c8 JG |
1003 | for (sig = 1; sig <= 31; sig++) { |
1004 | (void) signal(sig, SIG_DFL); | |
f8f66d38 | 1005 | } |
5b5bb8c8 | 1006 | return 0; |
a80ed305 JG |
1007 | } |
1008 | ||
1009 | static | |
1010 | void worker_sighandler(int sig) | |
1011 | { | |
1012 | const char *signame; | |
1013 | ||
1014 | /* | |
cd89f030 JG |
1015 | * The worker will inherit its parent's signals since they are part of |
1016 | * the same process group. However, in the case of SIGINT and SIGTERM, | |
1017 | * we want to give the worker a chance to teardown gracefully when its | |
1018 | * parent closes the command socket. | |
a80ed305 JG |
1019 | */ |
1020 | switch (sig) { | |
1021 | case SIGINT: | |
1022 | signame = "SIGINT"; | |
1023 | break; | |
1024 | case SIGTERM: | |
1025 | signame = "SIGTERM"; | |
1026 | break; | |
1027 | default: | |
22d5e48e | 1028 | signame = NULL; |
a80ed305 JG |
1029 | } |
1030 | ||
22d5e48e JG |
1031 | if (signame) { |
1032 | DBG("run_as worker received signal %s", signame); | |
1033 | } else { | |
1034 | DBG("run_as_worker received signal %d", sig); | |
1035 | } | |
a80ed305 JG |
1036 | } |
1037 | ||
1038 | static | |
1039 | int set_worker_sighandlers(void) | |
1040 | { | |
1041 | int ret = 0; | |
1042 | sigset_t sigset; | |
1043 | struct sigaction sa; | |
1044 | ||
1045 | if ((ret = sigemptyset(&sigset)) < 0) { | |
1046 | PERROR("sigemptyset"); | |
1047 | goto end; | |
1048 | } | |
1049 | ||
1050 | sa.sa_handler = worker_sighandler; | |
1051 | sa.sa_mask = sigset; | |
1052 | sa.sa_flags = 0; | |
1053 | if ((ret = sigaction(SIGINT, &sa, NULL)) < 0) { | |
1054 | PERROR("sigaction SIGINT"); | |
1055 | goto end; | |
1056 | } | |
1057 | ||
1058 | if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) { | |
1059 | PERROR("sigaction SIGTERM"); | |
1060 | goto end; | |
1061 | } | |
1062 | ||
1063 | DBG("run_as signal handler set for SIGTERM and SIGINT"); | |
1064 | end: | |
1065 | return ret; | |
f8f66d38 JG |
1066 | } |
1067 | ||
7567352f MD |
1068 | LTTNG_HIDDEN |
1069 | int run_as_create_worker(char *procname) | |
1070 | { | |
1071 | pid_t pid; | |
1072 | int i, ret = 0; | |
1073 | ssize_t readlen; | |
1074 | struct run_as_ret recvret; | |
1075 | struct run_as_worker *worker; | |
1076 | ||
749b7a0c JG |
1077 | pthread_mutex_lock(&worker_lock); |
1078 | assert(!global_worker); | |
7567352f | 1079 | if (!use_clone()) { |
749b7a0c JG |
1080 | /* |
1081 | * Don't initialize a worker, all run_as tasks will be performed | |
1082 | * in the current process. | |
1083 | */ | |
7567352f MD |
1084 | ret = 0; |
1085 | goto end; | |
1086 | } | |
1087 | worker = zmalloc(sizeof(*worker)); | |
1088 | if (!worker) { | |
1089 | ret = -ENOMEM; | |
1090 | goto end; | |
1091 | } | |
1092 | worker->procname = procname; | |
1093 | /* Create unix socket. */ | |
1094 | if (lttcomm_create_anon_unix_socketpair(worker->sockpair) < 0) { | |
1095 | ret = -1; | |
1096 | goto error_sock; | |
1097 | } | |
fe9f7760 | 1098 | |
7567352f MD |
1099 | /* Fork worker. */ |
1100 | pid = fork(); | |
1101 | if (pid < 0) { | |
1102 | PERROR("fork"); | |
1103 | ret = -1; | |
1104 | goto error_fork; | |
1105 | } else if (pid == 0) { | |
1106 | /* Child */ | |
1107 | ||
f8f66d38 JG |
1108 | reset_sighandler(); |
1109 | ||
a80ed305 JG |
1110 | set_worker_sighandlers(); |
1111 | ||
749b7a0c JG |
1112 | /* The child has no use for this lock. */ |
1113 | pthread_mutex_unlock(&worker_lock); | |
7567352f MD |
1114 | /* Just close, no shutdown. */ |
1115 | if (close(worker->sockpair[0])) { | |
1116 | PERROR("close"); | |
1117 | exit(EXIT_FAILURE); | |
1118 | } | |
fe9f7760 FD |
1119 | |
1120 | /* | |
1121 | * Close all FDs aside from STDIN, STDOUT, STDERR and sockpair[1] | |
1122 | * Sockpair[1] is used as a control channel with the master | |
1123 | */ | |
1124 | for (i = 3; i < sysconf(_SC_OPEN_MAX); i++) { | |
1125 | if (i != worker->sockpair[1]) { | |
1126 | (void) close(i); | |
1127 | } | |
1128 | } | |
1129 | ||
7567352f MD |
1130 | worker->sockpair[0] = -1; |
1131 | ret = run_as_worker(worker); | |
1132 | if (lttcomm_close_unix_sock(worker->sockpair[1])) { | |
1133 | PERROR("close"); | |
1134 | ret = -1; | |
1135 | } | |
1136 | worker->sockpair[1] = -1; | |
978d5d79 | 1137 | LOG(ret ? PRINT_ERR : PRINT_DBG, "run_as worker exiting (ret = %d)", ret); |
7567352f MD |
1138 | exit(ret ? EXIT_FAILURE : EXIT_SUCCESS); |
1139 | } else { | |
1140 | /* Parent */ | |
1141 | ||
1142 | /* Just close, no shutdown. */ | |
1143 | if (close(worker->sockpair[1])) { | |
1144 | PERROR("close"); | |
1145 | ret = -1; | |
1146 | goto error_fork; | |
1147 | } | |
1148 | worker->sockpair[1] = -1; | |
1149 | worker->pid = pid; | |
1150 | /* Wait for worker to become ready. */ | |
1151 | readlen = lttcomm_recv_unix_sock(worker->sockpair[0], | |
1152 | &recvret, sizeof(recvret)); | |
1153 | if (readlen < sizeof(recvret)) { | |
1154 | ERR("readlen: %zd", readlen); | |
1155 | PERROR("Error reading response from run_as at creation"); | |
1156 | ret = -1; | |
1157 | goto error_fork; | |
1158 | } | |
1159 | global_worker = worker; | |
1160 | } | |
1161 | end: | |
749b7a0c | 1162 | pthread_mutex_unlock(&worker_lock); |
7567352f MD |
1163 | return ret; |
1164 | ||
1165 | /* Error handling. */ | |
1166 | error_fork: | |
1167 | for (i = 0; i < 2; i++) { | |
1168 | if (worker->sockpair[i] < 0) { | |
1169 | continue; | |
1170 | } | |
1171 | if (lttcomm_close_unix_sock(worker->sockpair[i])) { | |
1172 | PERROR("close"); | |
1173 | } | |
1174 | worker->sockpair[i] = -1; | |
1175 | } | |
1176 | error_sock: | |
1177 | free(worker); | |
749b7a0c | 1178 | pthread_mutex_unlock(&worker_lock); |
7567352f MD |
1179 | return ret; |
1180 | } | |
1181 | ||
1182 | LTTNG_HIDDEN | |
1183 | void run_as_destroy_worker(void) | |
1184 | { | |
1185 | struct run_as_worker *worker = global_worker; | |
7567352f | 1186 | |
978d5d79 | 1187 | DBG("Destroying run_as worker"); |
749b7a0c | 1188 | pthread_mutex_lock(&worker_lock); |
7567352f | 1189 | if (!worker) { |
749b7a0c | 1190 | goto end; |
7567352f MD |
1191 | } |
1192 | /* Close unix socket */ | |
978d5d79 | 1193 | DBG("Closing run_as worker socket"); |
7567352f MD |
1194 | if (lttcomm_close_unix_sock(worker->sockpair[0])) { |
1195 | PERROR("close"); | |
1196 | } | |
1197 | worker->sockpair[0] = -1; | |
1198 | /* Wait for worker. */ | |
f8f66d38 JG |
1199 | for (;;) { |
1200 | int status; | |
1201 | pid_t wait_ret; | |
1202 | ||
1203 | wait_ret = waitpid(worker->pid, &status, 0); | |
1204 | if (wait_ret < 0) { | |
1205 | if (errno == EINTR) { | |
1206 | continue; | |
1207 | } | |
1208 | PERROR("waitpid"); | |
1209 | break; | |
1210 | } | |
1211 | ||
1212 | if (WIFEXITED(status)) { | |
1213 | LOG(WEXITSTATUS(status) == 0 ? PRINT_DBG : PRINT_ERR, | |
1214 | DEFAULT_RUN_AS_WORKER_NAME " terminated with status code %d", | |
1215 | WEXITSTATUS(status)); | |
1216 | break; | |
1217 | } else if (WIFSIGNALED(status)) { | |
1218 | ERR(DEFAULT_RUN_AS_WORKER_NAME " was killed by signal %d", | |
1219 | WTERMSIG(status)); | |
1220 | break; | |
1221 | } | |
7567352f MD |
1222 | } |
1223 | free(worker); | |
1224 | global_worker = NULL; | |
749b7a0c JG |
1225 | end: |
1226 | pthread_mutex_unlock(&worker_lock); | |
4628484a | 1227 | } |