b1a4b4836a63324b246940fb02f2727a1be90c05
[lttng-tools.git] / src / common / runas.c
1 /*
2 * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca>
3 * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
4 * Copyright (C) 2019 Jérémie Galarneau <jeremie.galarneau@efficios.com>
5 *
6 * SPDX-License-Identifier: GPL-2.0-only
7 *
8 */
9
10 #define _LGPL_SOURCE
11 #include <errno.h>
12 #include <limits.h>
13 #include <stdio.h>
14 #include <stdlib.h>
15 #include <string.h>
16 #include <sys/wait.h>
17 #include <sys/types.h>
18 #include <sys/stat.h>
19 #include <unistd.h>
20 #include <fcntl.h>
21 #include <sched.h>
22 #include <signal.h>
23 #include <assert.h>
24 #include <signal.h>
25
26 #include <common/lttng-kernel.h>
27 #include <common/common.h>
28 #include <common/utils.h>
29 #include <common/compat/getenv.h>
30 #include <common/unix.h>
31 #include <common/defaults.h>
32 #include <common/lttng-elf.h>
33 #include <common/thread.h>
34
35 #include <lttng/constant.h>
36
37 #include "runas.h"
38
39 struct run_as_data;
40 struct run_as_ret;
41 typedef int (*run_as_fct)(struct run_as_data *data, struct run_as_ret *ret_value);
42
43 enum run_as_cmd {
44 RUN_AS_MKDIR,
45 RUN_AS_MKDIRAT,
46 RUN_AS_MKDIR_RECURSIVE,
47 RUN_AS_MKDIRAT_RECURSIVE,
48 RUN_AS_OPEN,
49 RUN_AS_OPENAT,
50 RUN_AS_UNLINK,
51 RUN_AS_UNLINKAT,
52 RUN_AS_RMDIR,
53 RUN_AS_RMDIRAT,
54 RUN_AS_RMDIR_RECURSIVE,
55 RUN_AS_RMDIRAT_RECURSIVE,
56 RUN_AS_RENAME,
57 RUN_AS_RENAMEAT,
58 RUN_AS_EXTRACT_ELF_SYMBOL_OFFSET,
59 RUN_AS_EXTRACT_SDT_PROBE_OFFSETS,
60 };
61
62 struct run_as_mkdir_data {
63 int dirfd;
64 char path[LTTNG_PATH_MAX];
65 mode_t mode;
66 } LTTNG_PACKED;
67
68 struct run_as_open_data {
69 int dirfd;
70 char path[LTTNG_PATH_MAX];
71 int flags;
72 mode_t mode;
73 } LTTNG_PACKED;
74
75 struct run_as_unlink_data {
76 int dirfd;
77 char path[LTTNG_PATH_MAX];
78 } LTTNG_PACKED;
79
80 struct run_as_rmdir_data {
81 int dirfd;
82 char path[LTTNG_PATH_MAX];
83 int flags; /* enum lttng_directory_handle_rmdir_recursive_flags */
84 } LTTNG_PACKED;
85
86 struct run_as_extract_elf_symbol_offset_data {
87 int fd;
88 char function[LTTNG_SYMBOL_NAME_LEN];
89 } LTTNG_PACKED;
90
91 struct run_as_extract_sdt_probe_offsets_data {
92 int fd;
93 char probe_name[LTTNG_SYMBOL_NAME_LEN];
94 char provider_name[LTTNG_SYMBOL_NAME_LEN];
95 } LTTNG_PACKED;
96
97 struct run_as_rename_data {
98 /*
99 * [0] = old_dirfd
100 * [1] = new_dirfd
101 */
102 int dirfds[2];
103 char old_path[LTTNG_PATH_MAX];
104 char new_path[LTTNG_PATH_MAX];
105 } LTTNG_PACKED;
106
107 struct run_as_open_ret {
108 int fd;
109 } LTTNG_PACKED;
110
111 struct run_as_extract_elf_symbol_offset_ret {
112 uint64_t offset;
113 } LTTNG_PACKED;
114
115 struct run_as_extract_sdt_probe_offsets_ret {
116 uint32_t num_offset;
117 uint64_t offsets[LTTNG_KERNEL_MAX_UPROBE_NUM];
118 } LTTNG_PACKED;
119
120 struct run_as_data {
121 enum run_as_cmd cmd;
122 union {
123 struct run_as_mkdir_data mkdir;
124 struct run_as_open_data open;
125 struct run_as_unlink_data unlink;
126 struct run_as_rmdir_data rmdir;
127 struct run_as_rename_data rename;
128 struct run_as_extract_elf_symbol_offset_data extract_elf_symbol_offset;
129 struct run_as_extract_sdt_probe_offsets_data extract_sdt_probe_offsets;
130 } u;
131 uid_t uid;
132 gid_t gid;
133 } LTTNG_PACKED;
134
135 /*
136 * The run_as_ret structure holds the returned value and status of the command.
137 *
138 * The `u` union field holds the return value of the command; in most cases it
139 * represents the success or the failure of the command. In more complex
140 * commands, it holds a computed value.
141 *
142 * The _errno field is the errno recorded after the execution of the command.
143 *
144 * The _error fields is used the signify that return status of the command. For
145 * simple commands returning `int` the _error field will be the same as the
146 * ret_int field. In complex commands, it signify the success or failure of the
147 * command.
148 *
149 */
150 struct run_as_ret {
151 union {
152 int ret;
153 struct run_as_open_ret open;
154 struct run_as_extract_elf_symbol_offset_ret extract_elf_symbol_offset;
155 struct run_as_extract_sdt_probe_offsets_ret extract_sdt_probe_offsets;
156 } u;
157 int _errno;
158 bool _error;
159 } LTTNG_PACKED;
160
161 #define COMMAND_IN_FDS(data_ptr) ({ \
162 int *fds = NULL; \
163 if (command_properties[data_ptr->cmd].in_fds_offset != -1) { \
164 fds = (int *) ((char *) data_ptr + command_properties[data_ptr->cmd].in_fds_offset); \
165 } \
166 fds; \
167 })
168
169 #define COMMAND_OUT_FDS(cmd, ret_ptr) ({ \
170 int *fds = NULL; \
171 if (command_properties[cmd].out_fds_offset != -1) { \
172 fds = (int *) ((char *) ret_ptr + command_properties[cmd].out_fds_offset); \
173 } \
174 fds; \
175 })
176
177 #define COMMAND_IN_FD_COUNT(data_ptr) ({ \
178 command_properties[data_ptr->cmd].in_fd_count; \
179 })
180
181 #define COMMAND_OUT_FD_COUNT(cmd) ({ \
182 command_properties[cmd].out_fd_count; \
183 })
184
185 #define COMMAND_USE_CWD_FD(data_ptr) command_properties[data_ptr->cmd].use_cwd_fd
186
187 struct run_as_command_properties {
188 /* Set to -1 when not applicable. */
189 ptrdiff_t in_fds_offset, out_fds_offset;
190 unsigned int in_fd_count, out_fd_count;
191 bool use_cwd_fd;
192 };
193
194 static const struct run_as_command_properties command_properties[] = {
195 [RUN_AS_MKDIR] = {
196 .in_fds_offset = offsetof(struct run_as_data, u.mkdir.dirfd),
197 .in_fd_count = 1,
198 .out_fds_offset = -1,
199 .out_fd_count = 0,
200 .use_cwd_fd = true,
201 },
202 [RUN_AS_MKDIRAT] = {
203 .in_fds_offset = offsetof(struct run_as_data, u.mkdir.dirfd),
204 .in_fd_count = 1,
205 .out_fds_offset = -1,
206 .out_fd_count = 0,
207 .use_cwd_fd = false,
208 },
209 [RUN_AS_MKDIR_RECURSIVE] = {
210 .in_fds_offset = offsetof(struct run_as_data, u.mkdir.dirfd),
211 .in_fd_count = 1,
212 .out_fds_offset = -1,
213 .out_fd_count = 0,
214 .use_cwd_fd = true,
215 },
216 [RUN_AS_MKDIRAT_RECURSIVE] = {
217 .in_fds_offset = offsetof(struct run_as_data, u.mkdir.dirfd),
218 .in_fd_count = 1,
219 .out_fds_offset = -1,
220 .out_fd_count = 0,
221 .use_cwd_fd = false,
222 },
223 [RUN_AS_OPEN] = {
224 .in_fds_offset = offsetof(struct run_as_data, u.open.dirfd),
225 .in_fd_count = 1,
226 .out_fds_offset = offsetof(struct run_as_ret, u.open.fd),
227 .out_fd_count = 1,
228 .use_cwd_fd = true,
229 },
230 [RUN_AS_OPENAT] = {
231 .in_fds_offset = offsetof(struct run_as_data, u.open.dirfd),
232 .in_fd_count = 1,
233 .out_fds_offset = offsetof(struct run_as_ret, u.open.fd),
234 .out_fd_count = 1,
235 .use_cwd_fd = false,
236 },
237 [RUN_AS_UNLINK] = {
238 .in_fds_offset = offsetof(struct run_as_data, u.unlink.dirfd),
239 .in_fd_count = 1,
240 .out_fds_offset = -1,
241 .out_fd_count = 0,
242 .use_cwd_fd = true,
243 },
244 [RUN_AS_UNLINKAT] = {
245 .in_fds_offset = offsetof(struct run_as_data, u.unlink.dirfd),
246 .in_fd_count = 1,
247 .out_fds_offset = -1,
248 .out_fd_count = 0,
249 .use_cwd_fd = false,
250 },
251 [RUN_AS_RMDIR_RECURSIVE] = {
252 .in_fds_offset = offsetof(struct run_as_data, u.rmdir.dirfd),
253 .in_fd_count = 1,
254 .out_fds_offset = -1,
255 .out_fd_count = 0,
256 .use_cwd_fd = true,
257 },
258 [RUN_AS_RMDIRAT_RECURSIVE] = {
259 .in_fds_offset = offsetof(struct run_as_data, u.rmdir.dirfd),
260 .in_fd_count = 1,
261 .out_fds_offset = -1,
262 .out_fd_count = 0,
263 .use_cwd_fd = false,
264 },
265 [RUN_AS_RMDIR] = {
266 .in_fds_offset = offsetof(struct run_as_data, u.rmdir.dirfd),
267 .in_fd_count = 1,
268 .out_fds_offset = -1,
269 .out_fd_count = 0,
270 .use_cwd_fd = true,
271 },
272 [RUN_AS_RMDIRAT] = {
273 .in_fds_offset = offsetof(struct run_as_data, u.rmdir.dirfd),
274 .in_fd_count = 1,
275 .out_fds_offset = -1,
276 .out_fd_count = 0,
277 .use_cwd_fd = false,
278 },
279 [RUN_AS_RENAME] = {
280 .in_fds_offset = offsetof(struct run_as_data, u.rename.dirfds),
281 .in_fd_count = 2,
282 .out_fds_offset = -1,
283 .out_fd_count = 0,
284 .use_cwd_fd = true,
285 },
286 [RUN_AS_RENAMEAT] = {
287 .in_fds_offset = offsetof(struct run_as_data, u.rename.dirfds),
288 .in_fd_count = 2,
289 .out_fds_offset = -1,
290 .out_fd_count = 0,
291 .use_cwd_fd = false,
292 },
293 [RUN_AS_EXTRACT_ELF_SYMBOL_OFFSET] = {
294 .in_fds_offset = offsetof(struct run_as_data,
295 u.extract_elf_symbol_offset.fd),
296 .in_fd_count = 1,
297 .out_fds_offset = -1,
298 .out_fd_count = 0,
299 .use_cwd_fd = false,
300 },
301 [RUN_AS_EXTRACT_SDT_PROBE_OFFSETS] = {
302 .in_fds_offset = offsetof(struct run_as_data,
303 u.extract_sdt_probe_offsets.fd),
304 .in_fd_count = 1,
305 .out_fds_offset = -1,
306 .out_fd_count = 0,
307 .use_cwd_fd = false,
308 },
309 };
310
311 struct run_as_worker {
312 pid_t pid; /* Worker PID. */
313 int sockpair[2];
314 char *procname;
315 };
316
317 /* Single global worker per process (for now). */
318 static struct run_as_worker *global_worker;
319 /* Lock protecting the worker. */
320 static pthread_mutex_t worker_lock = PTHREAD_MUTEX_INITIALIZER;
321
322 #ifdef VALGRIND
323 static
324 int use_clone(void)
325 {
326 return 0;
327 }
328 #else
329 static
330 int use_clone(void)
331 {
332 return !lttng_secure_getenv("LTTNG_DEBUG_NOCLONE");
333 }
334 #endif
335
336 /*
337 * Create recursively directory using the FULL path.
338 */
339 static
340 int _mkdirat_recursive(struct run_as_data *data, struct run_as_ret *ret_value)
341 {
342 const char *path;
343 mode_t mode;
344 struct lttng_directory_handle *handle;
345
346 path = data->u.mkdir.path;
347 mode = data->u.mkdir.mode;
348
349 handle = lttng_directory_handle_create_from_dirfd(data->u.mkdir.dirfd);
350 if (!handle) {
351 ret_value->_errno = errno;
352 ret_value->_error = true;
353 ret_value->u.ret = -1;
354 goto end;
355 }
356 /* Ownership of dirfd is transferred to the handle. */
357 data->u.mkdir.dirfd = -1;
358 /* Safe to call as we have transitioned to the requested uid/gid. */
359 ret_value->u.ret = lttng_directory_handle_create_subdirectory_recursive(
360 handle, path, mode);
361 ret_value->_errno = errno;
362 ret_value->_error = (ret_value->u.ret) ? true : false;
363 lttng_directory_handle_put(handle);
364 end:
365 return ret_value->u.ret;
366 }
367
368 static
369 int _mkdirat(struct run_as_data *data, struct run_as_ret *ret_value)
370 {
371 const char *path;
372 mode_t mode;
373 struct lttng_directory_handle *handle;
374
375 path = data->u.mkdir.path;
376 mode = data->u.mkdir.mode;
377
378 handle = lttng_directory_handle_create_from_dirfd(data->u.mkdir.dirfd);
379 if (!handle) {
380 ret_value->u.ret = -1;
381 ret_value->_errno = errno;
382 ret_value->_error = true;
383 goto end;
384 }
385 /* Ownership of dirfd is transferred to the handle. */
386 data->u.mkdir.dirfd = -1;
387 /* Safe to call as we have transitioned to the requested uid/gid. */
388 ret_value->u.ret = lttng_directory_handle_create_subdirectory(
389 handle, path, mode);
390 ret_value->_errno = errno;
391 ret_value->_error = (ret_value->u.ret) ? true : false;
392 lttng_directory_handle_put(handle);
393 end:
394 return ret_value->u.ret;
395 }
396
397 static
398 int _open(struct run_as_data *data, struct run_as_ret *ret_value)
399 {
400 int fd;
401 struct lttng_directory_handle *handle;
402
403 handle = lttng_directory_handle_create_from_dirfd(data->u.open.dirfd);
404 if (!handle) {
405 ret_value->_errno = errno;
406 ret_value->_error = true;
407 ret_value->u.ret = -1;
408 goto end;
409 }
410 /* Ownership of dirfd is transferred to the handle. */
411 data->u.open.dirfd = -1;
412
413 fd = lttng_directory_handle_open_file(handle,
414 data->u.open.path, data->u.open.flags,
415 data->u.open.mode);
416 if (fd < 0) {
417 ret_value->u.ret = -1;
418 ret_value->u.open.fd = -1;
419 } else {
420 ret_value->u.ret = 0;
421 ret_value->u.open.fd = fd;
422 }
423
424 ret_value->_errno = errno;
425 ret_value->_error = fd < 0;
426 lttng_directory_handle_put(handle);
427 end:
428 return ret_value->u.ret;
429 }
430
431 static
432 int _unlink(struct run_as_data *data, struct run_as_ret *ret_value)
433 {
434 struct lttng_directory_handle *handle;
435
436 handle = lttng_directory_handle_create_from_dirfd(data->u.unlink.dirfd);
437 if (!handle) {
438 ret_value->u.ret = -1;
439 ret_value->_errno = errno;
440 ret_value->_error = true;
441 goto end;
442 }
443
444 /* Ownership of dirfd is transferred to the handle. */
445 data->u.unlink.dirfd = -1;
446
447 ret_value->u.ret = lttng_directory_handle_unlink_file(handle,
448 data->u.unlink.path);
449 ret_value->_errno = errno;
450 ret_value->_error = (ret_value->u.ret) ? true : false;
451 lttng_directory_handle_put(handle);
452 end:
453 return ret_value->u.ret;
454 }
455
456 static
457 int _rmdir(struct run_as_data *data, struct run_as_ret *ret_value)
458 {
459 struct lttng_directory_handle *handle;
460
461 handle = lttng_directory_handle_create_from_dirfd(data->u.rmdir.dirfd);
462 if (!handle) {
463 ret_value->u.ret = -1;
464 ret_value->_errno = errno;
465 ret_value->_error = true;
466 goto end;
467 }
468
469 /* Ownership of dirfd is transferred to the handle. */
470 data->u.rmdir.dirfd = -1;
471
472 ret_value->u.ret = lttng_directory_handle_remove_subdirectory(
473 handle, data->u.rmdir.path);
474 ret_value->_errno = errno;
475 ret_value->_error = (ret_value->u.ret) ? true : false;
476 lttng_directory_handle_put(handle);
477 end:
478 return ret_value->u.ret;
479 }
480
481 static
482 int _rmdir_recursive(struct run_as_data *data, struct run_as_ret *ret_value)
483 {
484 struct lttng_directory_handle *handle;
485
486 handle = lttng_directory_handle_create_from_dirfd(data->u.rmdir.dirfd);
487 if (!handle) {
488 ret_value->u.ret = -1;
489 ret_value->_errno = errno;
490 ret_value->_error = true;
491 goto end;
492 }
493
494 /* Ownership of dirfd is transferred to the handle. */
495 data->u.rmdir.dirfd = -1;
496
497 ret_value->u.ret = lttng_directory_handle_remove_subdirectory_recursive(
498 handle, data->u.rmdir.path, data->u.rmdir.flags);
499 ret_value->_errno = errno;
500 ret_value->_error = (ret_value->u.ret) ? true : false;
501 lttng_directory_handle_put(handle);
502 end:
503 return ret_value->u.ret;
504 }
505
506 static
507 int _rename(struct run_as_data *data, struct run_as_ret *ret_value)
508 {
509 const char *old_path, *new_path;
510 struct lttng_directory_handle *old_handle = NULL, *new_handle = NULL;
511
512 old_path = data->u.rename.old_path;
513 new_path = data->u.rename.new_path;
514
515 old_handle = lttng_directory_handle_create_from_dirfd(
516 data->u.rename.dirfds[0]);
517 if (!old_handle) {
518 ret_value->u.ret = -1;
519 goto end;
520 }
521 new_handle = lttng_directory_handle_create_from_dirfd(
522 data->u.rename.dirfds[1]);
523 if (!new_handle) {
524 ret_value->u.ret = -1;
525 goto end;
526 }
527
528 /* Ownership of dirfds are transferred to the handles. */
529 data->u.rename.dirfds[0] = data->u.rename.dirfds[1] = -1;
530
531 /* Safe to call as we have transitioned to the requested uid/gid. */
532 ret_value->u.ret = lttng_directory_handle_rename(
533 old_handle, old_path, new_handle, new_path);
534 end:
535 lttng_directory_handle_put(old_handle);
536 lttng_directory_handle_put(new_handle);
537 ret_value->_errno = errno;
538 ret_value->_error = (ret_value->u.ret) ? true : false;
539 return ret_value->u.ret;
540 }
541
542 #ifdef HAVE_ELF_H
543 static
544 int _extract_elf_symbol_offset(struct run_as_data *data,
545 struct run_as_ret *ret_value)
546 {
547 int ret = 0;
548 uint64_t offset;
549
550 ret_value->_error = false;
551 ret = lttng_elf_get_symbol_offset(data->u.extract_elf_symbol_offset.fd,
552 data->u.extract_elf_symbol_offset.function,
553 &offset);
554 if (ret) {
555 DBG("Failed to extract ELF function offset");
556 ret_value->_error = true;
557 }
558 ret_value->u.extract_elf_symbol_offset.offset = offset;
559
560 return ret;
561 }
562
563 static
564 int _extract_sdt_probe_offsets(struct run_as_data *data,
565 struct run_as_ret *ret_value)
566 {
567 int ret = 0;
568 uint64_t *offsets = NULL;
569 uint32_t num_offset;
570
571 ret_value->_error = false;
572
573 /* On success, this call allocates the offsets paramater. */
574 ret = lttng_elf_get_sdt_probe_offsets(
575 data->u.extract_sdt_probe_offsets.fd,
576 data->u.extract_sdt_probe_offsets.provider_name,
577 data->u.extract_sdt_probe_offsets.probe_name,
578 &offsets, &num_offset);
579
580 if (ret) {
581 DBG("Failed to extract SDT probe offsets");
582 ret_value->_error = true;
583 goto end;
584 }
585
586 if (num_offset <= 0 || num_offset > LTTNG_KERNEL_MAX_UPROBE_NUM) {
587 DBG("Wrong number of probes.");
588 ret = -1;
589 ret_value->_error = true;
590 goto free_offset;
591 }
592
593 /* Copy the content of the offsets array to the ret struct. */
594 memcpy(ret_value->u.extract_sdt_probe_offsets.offsets,
595 offsets, num_offset * sizeof(uint64_t));
596
597 ret_value->u.extract_sdt_probe_offsets.num_offset = num_offset;
598
599 free_offset:
600 free(offsets);
601 end:
602 return ret;
603 }
604 #else
605 static
606 int _extract_elf_symbol_offset(struct run_as_data *data,
607 struct run_as_ret *ret_value)
608 {
609 ERR("Unimplemented runas command RUN_AS_EXTRACT_ELF_SYMBOL_OFFSET");
610 return -1;
611 }
612
613 static
614 int _extract_sdt_probe_offsets(struct run_as_data *data,
615 struct run_as_ret *ret_value)
616 {
617 ERR("Unimplemented runas command RUN_AS_EXTRACT_SDT_PROBE_OFFSETS");
618 return -1;
619 }
620 #endif
621
622 static
623 run_as_fct run_as_enum_to_fct(enum run_as_cmd cmd)
624 {
625 switch (cmd) {
626 case RUN_AS_MKDIR:
627 case RUN_AS_MKDIRAT:
628 return _mkdirat;
629 case RUN_AS_MKDIR_RECURSIVE:
630 case RUN_AS_MKDIRAT_RECURSIVE:
631 return _mkdirat_recursive;
632 case RUN_AS_OPEN:
633 case RUN_AS_OPENAT:
634 return _open;
635 case RUN_AS_UNLINK:
636 case RUN_AS_UNLINKAT:
637 return _unlink;
638 case RUN_AS_RMDIR:
639 case RUN_AS_RMDIRAT:
640 return _rmdir;
641 case RUN_AS_RMDIR_RECURSIVE:
642 case RUN_AS_RMDIRAT_RECURSIVE:
643 return _rmdir_recursive;
644 case RUN_AS_RENAME:
645 case RUN_AS_RENAMEAT:
646 return _rename;
647 case RUN_AS_EXTRACT_ELF_SYMBOL_OFFSET:
648 return _extract_elf_symbol_offset;
649 case RUN_AS_EXTRACT_SDT_PROBE_OFFSETS:
650 return _extract_sdt_probe_offsets;
651 default:
652 ERR("Unknown command %d", (int) cmd);
653 return NULL;
654 }
655 }
656
657 static
658 int do_send_fds(int sock, const int *fds, unsigned int fd_count)
659 {
660 ssize_t len;
661 unsigned int i;
662
663 for (i = 0; i < fd_count; i++) {
664 if (fds[i] < 0) {
665 ERR("Attempt to send invalid file descriptor to master (fd = %i)",
666 fds[i]);
667 /* Return 0 as this is not a fatal error. */
668 return 0;
669 }
670 }
671
672 len = lttcomm_send_fds_unix_sock(sock, fds, fd_count);
673 return len < 0 ? -1 : 0;
674 }
675
676 static
677 int do_recv_fds(int sock, int *fds, unsigned int fd_count)
678 {
679 int ret = 0;
680 unsigned int i;
681 ssize_t len;
682
683 len = lttcomm_recv_fds_unix_sock(sock, fds, fd_count);
684 if (len == 0) {
685 ret = -1;
686 goto end;
687 } else if (len < 0) {
688 PERROR("Failed to receive file descriptors from socket");
689 ret = -1;
690 goto end;
691 }
692
693 for (i = 0; i < fd_count; i++) {
694 if (fds[i] < 0) {
695 ERR("Invalid file descriptor received from worker (fd = %i)", fds[i]);
696 /* Return 0 as this is not a fatal error. */
697 }
698 }
699 end:
700 return ret;
701 }
702
703 static
704 int send_fds_to_worker(const struct run_as_worker *worker,
705 const struct run_as_data *data)
706 {
707 int ret = 0;
708 unsigned int i;
709
710 if (COMMAND_USE_CWD_FD(data) || COMMAND_IN_FD_COUNT(data) == 0) {
711 goto end;
712 }
713
714 for (i = 0; i < COMMAND_IN_FD_COUNT(data); i++) {
715 if (COMMAND_IN_FDS(data)[i] < 0) {
716 ERR("Refusing to send invalid fd to worker (fd = %i)",
717 COMMAND_IN_FDS(data)[i]);
718 ret = -1;
719 goto end;
720 }
721 }
722
723 ret = do_send_fds(worker->sockpair[0], COMMAND_IN_FDS(data),
724 COMMAND_IN_FD_COUNT(data));
725 if (ret < 0) {
726 PERROR("Failed to send file descriptor to run-as worker");
727 ret = -1;
728 goto end;
729 }
730 end:
731 return ret;
732 }
733
734 static
735 int send_fds_to_master(struct run_as_worker *worker, enum run_as_cmd cmd,
736 struct run_as_ret *run_as_ret)
737 {
738 int ret = 0;
739 unsigned int i;
740
741 if (COMMAND_OUT_FD_COUNT(cmd) == 0) {
742 goto end;
743 }
744
745 ret = do_send_fds(worker->sockpair[1], COMMAND_OUT_FDS(cmd, run_as_ret),
746 COMMAND_OUT_FD_COUNT(cmd));
747 if (ret < 0) {
748 PERROR("Failed to send file descriptor to master process");
749 goto end;
750 }
751
752 for (i = 0; i < COMMAND_OUT_FD_COUNT(cmd); i++) {
753 int ret_close = close(COMMAND_OUT_FDS(cmd, run_as_ret)[i]);
754
755 if (ret_close < 0) {
756 PERROR("Failed to close result file descriptor");
757 }
758 }
759 end:
760 return ret;
761 }
762
763 static
764 int recv_fds_from_worker(const struct run_as_worker *worker, enum run_as_cmd cmd,
765 struct run_as_ret *run_as_ret)
766 {
767 int ret = 0;
768
769 if (COMMAND_OUT_FD_COUNT(cmd) == 0) {
770 goto end;
771 }
772
773 ret = do_recv_fds(worker->sockpair[0], COMMAND_OUT_FDS(cmd, run_as_ret),
774 COMMAND_OUT_FD_COUNT(cmd));
775 if (ret < 0) {
776 PERROR("Failed to receive file descriptor from run-as worker");
777 ret = -1;
778 }
779 end:
780 return ret;
781 }
782
783 static
784 int recv_fds_from_master(struct run_as_worker *worker, struct run_as_data *data)
785 {
786 int ret = 0;
787
788 if (COMMAND_USE_CWD_FD(data)) {
789 unsigned int i;
790
791 for (i = 0; i < COMMAND_IN_FD_COUNT(data); i++) {
792 COMMAND_IN_FDS(data)[i] = AT_FDCWD;
793 }
794 goto end;
795 }
796
797 ret = do_recv_fds(worker->sockpair[1], COMMAND_IN_FDS(data),
798 COMMAND_IN_FD_COUNT(data));
799 if (ret < 0) {
800 PERROR("Failed to receive file descriptors from master process");
801 ret = -1;
802 }
803 end:
804 return ret;
805 }
806
807 static
808 int cleanup_received_fds(struct run_as_data *data)
809 {
810 int ret = 0, i;
811
812 for (i = 0; i < COMMAND_IN_FD_COUNT(data); i++) {
813 if (COMMAND_IN_FDS(data)[i] == -1) {
814 continue;
815 }
816 ret = close(COMMAND_IN_FDS(data)[i]);
817 if (ret) {
818 PERROR("Failed to close file descriptor received fd in run-as worker");
819 goto end;
820 }
821 }
822 end:
823 return ret;
824 }
825
826 /*
827 * Return < 0 on error, 0 if OK, 1 on hangup.
828 */
829 static
830 int handle_one_cmd(struct run_as_worker *worker)
831 {
832 int ret = 0;
833 struct run_as_data data = {};
834 ssize_t readlen, writelen;
835 struct run_as_ret sendret = {};
836 run_as_fct cmd;
837 uid_t prev_euid;
838
839 /*
840 * Stage 1: Receive run_as_data struct from the master.
841 * The structure contains the command type and all the parameters needed for
842 * its execution
843 */
844 readlen = lttcomm_recv_unix_sock(worker->sockpair[1], &data,
845 sizeof(data));
846 if (readlen == 0) {
847 /* hang up */
848 ret = 1;
849 goto end;
850 }
851 if (readlen < sizeof(data)) {
852 PERROR("lttcomm_recv_unix_sock error");
853 ret = -1;
854 goto end;
855 }
856
857 cmd = run_as_enum_to_fct(data.cmd);
858 if (!cmd) {
859 ret = -1;
860 goto end;
861 }
862
863 /*
864 * Stage 2: Receive file descriptor from master.
865 * Some commands need a file descriptor as input so if it's needed we
866 * receive the fd using the Unix socket.
867 */
868 ret = recv_fds_from_master(worker, &data);
869 if (ret < 0) {
870 PERROR("recv_fd_from_master error");
871 ret = -1;
872 goto end;
873 }
874
875 prev_euid = getuid();
876 if (data.gid != getegid()) {
877 ret = setegid(data.gid);
878 if (ret < 0) {
879 sendret._error = true;
880 sendret._errno = errno;
881 PERROR("setegid");
882 goto write_return;
883 }
884 }
885 if (data.uid != prev_euid) {
886 ret = seteuid(data.uid);
887 if (ret < 0) {
888 sendret._error = true;
889 sendret._errno = errno;
890 PERROR("seteuid");
891 goto write_return;
892 }
893 }
894
895 /*
896 * Also set umask to 0 for mkdir executable bit.
897 */
898 umask(0);
899
900 /*
901 * Stage 3: Execute the command
902 */
903 ret = (*cmd)(&data, &sendret);
904 if (ret < 0) {
905 DBG("Execution of command returned an error");
906 }
907
908 write_return:
909 ret = cleanup_received_fds(&data);
910 if (ret < 0) {
911 ERR("Error cleaning up FD");
912 goto end;
913 }
914
915 /*
916 * Stage 4: Send run_as_ret structure to the master.
917 * This structure contain the return value of the command and the errno.
918 */
919 writelen = lttcomm_send_unix_sock(worker->sockpair[1], &sendret,
920 sizeof(sendret));
921 if (writelen < sizeof(sendret)) {
922 PERROR("lttcomm_send_unix_sock error");
923 ret = -1;
924 goto end;
925 }
926
927 /*
928 * Stage 5: Send resulting file descriptors to the master.
929 */
930 ret = send_fds_to_master(worker, data.cmd, &sendret);
931 if (ret < 0) {
932 DBG("Sending FD to master returned an error");
933 goto end;
934 }
935
936 if (seteuid(prev_euid) < 0) {
937 PERROR("seteuid");
938 ret = -1;
939 goto end;
940 }
941 ret = 0;
942 end:
943 return ret;
944 }
945
946 static
947 int run_as_worker(struct run_as_worker *worker)
948 {
949 int ret;
950 ssize_t writelen;
951 struct run_as_ret sendret;
952 size_t proc_orig_len;
953
954 /*
955 * Initialize worker. Set a different process cmdline.
956 */
957 proc_orig_len = strlen(worker->procname);
958 memset(worker->procname, 0, proc_orig_len);
959 strncpy(worker->procname, DEFAULT_RUN_AS_WORKER_NAME, proc_orig_len);
960
961 ret = lttng_thread_setname(DEFAULT_RUN_AS_WORKER_NAME);
962 if (ret && ret != -ENOSYS) {
963 /* Don't fail as this is not essential. */
964 DBG("Failed to set pthread name attribute");
965 }
966
967 memset(&sendret, 0, sizeof(sendret));
968
969 writelen = lttcomm_send_unix_sock(worker->sockpair[1], &sendret,
970 sizeof(sendret));
971 if (writelen < sizeof(sendret)) {
972 PERROR("lttcomm_send_unix_sock error");
973 ret = EXIT_FAILURE;
974 goto end;
975 }
976
977 for (;;) {
978 ret = handle_one_cmd(worker);
979 if (ret < 0) {
980 ret = EXIT_FAILURE;
981 goto end;
982 } else if (ret > 0) {
983 break;
984 } else {
985 continue; /* Next command. */
986 }
987 }
988 ret = EXIT_SUCCESS;
989 end:
990 return ret;
991 }
992
993 static
994 int run_as_cmd(struct run_as_worker *worker,
995 enum run_as_cmd cmd,
996 struct run_as_data *data,
997 struct run_as_ret *ret_value,
998 uid_t uid, gid_t gid)
999 {
1000 int ret = 0;
1001 ssize_t readlen, writelen;
1002
1003 /*
1004 * If we are non-root, we can only deal with our own uid.
1005 */
1006 if (geteuid() != 0) {
1007 if (uid != geteuid()) {
1008 ret = -1;
1009 ret_value->_errno = EPERM;
1010 ERR("Client (%d)/Server (%d) UID mismatch (and sessiond is not root)",
1011 (int) uid, (int) geteuid());
1012 goto end;
1013 }
1014 }
1015
1016 data->cmd = cmd;
1017 data->uid = uid;
1018 data->gid = gid;
1019
1020 /*
1021 * Stage 1: Send the run_as_data struct to the worker process
1022 */
1023 writelen = lttcomm_send_unix_sock(worker->sockpair[0], data,
1024 sizeof(*data));
1025 if (writelen < sizeof(*data)) {
1026 PERROR("Error writing message to run_as");
1027 ret = -1;
1028 ret_value->_errno = EIO;
1029 goto end;
1030 }
1031
1032 /*
1033 * Stage 2: Send file descriptor to the worker process if needed
1034 */
1035 ret = send_fds_to_worker(worker, data);
1036 if (ret) {
1037 PERROR("do_send_fd error");
1038 ret = -1;
1039 ret_value->_errno = EIO;
1040 goto end;
1041 }
1042
1043 /*
1044 * Stage 3: Wait for the execution of the command
1045 */
1046
1047 /*
1048 * Stage 4: Receive the run_as_ret struct containing the return value and
1049 * errno
1050 */
1051 readlen = lttcomm_recv_unix_sock(worker->sockpair[0], ret_value,
1052 sizeof(*ret_value));
1053 if (!readlen) {
1054 ERR("Run-as worker has hung-up during run_as_cmd");
1055 ret = -1;
1056 ret_value->_errno = EIO;
1057 goto end;
1058 } else if (readlen < sizeof(*ret_value)) {
1059 PERROR("Error reading response from run_as");
1060 ret = -1;
1061 ret_value->_errno = errno;
1062 goto end;
1063 }
1064
1065 if (ret_value->_error) {
1066 /* Skip stage 5 on error as there will be no fd to receive. */
1067 goto end;
1068 }
1069
1070 /*
1071 * Stage 5: Receive file descriptor if needed
1072 */
1073 ret = recv_fds_from_worker(worker, cmd, ret_value);
1074 if (ret < 0) {
1075 ERR("Error receiving fd");
1076 ret = -1;
1077 ret_value->_errno = EIO;
1078 }
1079
1080 end:
1081 return ret;
1082 }
1083
1084 /*
1085 * This is for debugging ONLY and should not be considered secure.
1086 */
1087 static
1088 int run_as_noworker(enum run_as_cmd cmd,
1089 struct run_as_data *data, struct run_as_ret *ret_value,
1090 uid_t uid, gid_t gid)
1091 {
1092 int ret, saved_errno;
1093 mode_t old_mask;
1094 run_as_fct fct;
1095
1096 fct = run_as_enum_to_fct(cmd);
1097 if (!fct) {
1098 errno = -ENOSYS;
1099 ret = -1;
1100 goto end;
1101 }
1102 old_mask = umask(0);
1103 ret = fct(data, ret_value);
1104 saved_errno = ret_value->_errno;
1105 umask(old_mask);
1106 errno = saved_errno;
1107 end:
1108 return ret;
1109 }
1110
1111 static
1112 int reset_sighandler(void)
1113 {
1114 int sig;
1115
1116 DBG("Resetting run_as worker signal handlers to default");
1117 for (sig = 1; sig <= 31; sig++) {
1118 (void) signal(sig, SIG_DFL);
1119 }
1120 return 0;
1121 }
1122
1123 static
1124 void worker_sighandler(int sig)
1125 {
1126 const char *signame;
1127
1128 /*
1129 * The worker will inherit its parent's signals since they are part of
1130 * the same process group. However, in the case of SIGINT and SIGTERM,
1131 * we want to give the worker a chance to teardown gracefully when its
1132 * parent closes the command socket.
1133 */
1134 switch (sig) {
1135 case SIGINT:
1136 signame = "SIGINT";
1137 break;
1138 case SIGTERM:
1139 signame = "SIGTERM";
1140 break;
1141 default:
1142 signame = NULL;
1143 }
1144
1145 if (signame) {
1146 DBG("run_as worker received signal %s", signame);
1147 } else {
1148 DBG("run_as_worker received signal %d", sig);
1149 }
1150 }
1151
1152 static
1153 int set_worker_sighandlers(void)
1154 {
1155 int ret = 0;
1156 sigset_t sigset;
1157 struct sigaction sa;
1158
1159 if ((ret = sigemptyset(&sigset)) < 0) {
1160 PERROR("sigemptyset");
1161 goto end;
1162 }
1163
1164 sa.sa_handler = worker_sighandler;
1165 sa.sa_mask = sigset;
1166 sa.sa_flags = 0;
1167 if ((ret = sigaction(SIGINT, &sa, NULL)) < 0) {
1168 PERROR("sigaction SIGINT");
1169 goto end;
1170 }
1171
1172 if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) {
1173 PERROR("sigaction SIGTERM");
1174 goto end;
1175 }
1176
1177 DBG("run_as signal handler set for SIGTERM and SIGINT");
1178 end:
1179 return ret;
1180 }
1181
1182 static
1183 int run_as_create_worker_no_lock(const char *procname,
1184 post_fork_cleanup_cb clean_up_func,
1185 void *clean_up_user_data)
1186 {
1187 pid_t pid;
1188 int i, ret = 0;
1189 ssize_t readlen;
1190 struct run_as_ret recvret;
1191 struct run_as_worker *worker;
1192
1193 assert(!global_worker);
1194 if (!use_clone()) {
1195 /*
1196 * Don't initialize a worker, all run_as tasks will be performed
1197 * in the current process.
1198 */
1199 ret = 0;
1200 goto end;
1201 }
1202 worker = zmalloc(sizeof(*worker));
1203 if (!worker) {
1204 ret = -ENOMEM;
1205 goto end;
1206 }
1207 worker->procname = strdup(procname);
1208 if (!worker->procname) {
1209 ret = -ENOMEM;
1210 goto error_procname_alloc;
1211 }
1212 /* Create unix socket. */
1213 if (lttcomm_create_anon_unix_socketpair(worker->sockpair) < 0) {
1214 ret = -1;
1215 goto error_sock;
1216 }
1217
1218 /* Fork worker. */
1219 pid = fork();
1220 if (pid < 0) {
1221 PERROR("fork");
1222 ret = -1;
1223 goto error_fork;
1224 } else if (pid == 0) {
1225 /* Child */
1226
1227 reset_sighandler();
1228
1229 set_worker_sighandlers();
1230 if (clean_up_func) {
1231 if (clean_up_func(clean_up_user_data) < 0) {
1232 ERR("Run-as post-fork clean-up failed, exiting.");
1233 exit(EXIT_FAILURE);
1234 }
1235 }
1236
1237 /* Just close, no shutdown. */
1238 if (close(worker->sockpair[0])) {
1239 PERROR("close");
1240 exit(EXIT_FAILURE);
1241 }
1242
1243 /*
1244 * Close all FDs aside from STDIN, STDOUT, STDERR and sockpair[1]
1245 * Sockpair[1] is used as a control channel with the master
1246 */
1247 for (i = 3; i < sysconf(_SC_OPEN_MAX); i++) {
1248 if (i != worker->sockpair[1]) {
1249 (void) close(i);
1250 }
1251 }
1252
1253 worker->sockpair[0] = -1;
1254 ret = run_as_worker(worker);
1255 if (lttcomm_close_unix_sock(worker->sockpair[1])) {
1256 PERROR("close");
1257 ret = -1;
1258 }
1259 worker->sockpair[1] = -1;
1260 free(worker->procname);
1261 free(worker);
1262 LOG(ret ? PRINT_ERR : PRINT_DBG, "run_as worker exiting (ret = %d)", ret);
1263 exit(ret ? EXIT_FAILURE : EXIT_SUCCESS);
1264 } else {
1265 /* Parent */
1266
1267 /* Just close, no shutdown. */
1268 if (close(worker->sockpair[1])) {
1269 PERROR("close");
1270 ret = -1;
1271 goto error_fork;
1272 }
1273 worker->sockpair[1] = -1;
1274 worker->pid = pid;
1275 /* Wait for worker to become ready. */
1276 readlen = lttcomm_recv_unix_sock(worker->sockpair[0],
1277 &recvret, sizeof(recvret));
1278 if (readlen < sizeof(recvret)) {
1279 ERR("readlen: %zd", readlen);
1280 PERROR("Error reading response from run_as at creation");
1281 ret = -1;
1282 goto error_fork;
1283 }
1284 global_worker = worker;
1285 }
1286 end:
1287 return ret;
1288
1289 /* Error handling. */
1290 error_fork:
1291 for (i = 0; i < 2; i++) {
1292 if (worker->sockpair[i] < 0) {
1293 continue;
1294 }
1295 if (lttcomm_close_unix_sock(worker->sockpair[i])) {
1296 PERROR("close");
1297 }
1298 worker->sockpair[i] = -1;
1299 }
1300 error_sock:
1301 free(worker->procname);
1302 error_procname_alloc:
1303 free(worker);
1304 return ret;
1305 }
1306
1307 static
1308 void run_as_destroy_worker_no_lock(void)
1309 {
1310 struct run_as_worker *worker = global_worker;
1311
1312 DBG("Destroying run_as worker");
1313 if (!worker) {
1314 return;
1315 }
1316 /* Close unix socket */
1317 DBG("Closing run_as worker socket");
1318 if (lttcomm_close_unix_sock(worker->sockpair[0])) {
1319 PERROR("close");
1320 }
1321 worker->sockpair[0] = -1;
1322 /* Wait for worker. */
1323 for (;;) {
1324 int status;
1325 pid_t wait_ret;
1326
1327 wait_ret = waitpid(worker->pid, &status, 0);
1328 if (wait_ret < 0) {
1329 if (errno == EINTR) {
1330 continue;
1331 }
1332 PERROR("waitpid");
1333 break;
1334 }
1335
1336 if (WIFEXITED(status)) {
1337 LOG(WEXITSTATUS(status) == 0 ? PRINT_DBG : PRINT_ERR,
1338 DEFAULT_RUN_AS_WORKER_NAME " terminated with status code %d",
1339 WEXITSTATUS(status));
1340 break;
1341 } else if (WIFSIGNALED(status)) {
1342 ERR(DEFAULT_RUN_AS_WORKER_NAME " was killed by signal %d",
1343 WTERMSIG(status));
1344 break;
1345 }
1346 }
1347 free(worker->procname);
1348 free(worker);
1349 global_worker = NULL;
1350 }
1351
1352 static
1353 int run_as_restart_worker(struct run_as_worker *worker)
1354 {
1355 int ret = 0;
1356 char *procname = NULL;
1357
1358 procname = worker->procname;
1359
1360 /* Close socket to run_as worker process and clean up the zombie process */
1361 run_as_destroy_worker_no_lock();
1362
1363 /* Create a new run_as worker process*/
1364 ret = run_as_create_worker_no_lock(procname, NULL, NULL);
1365 if (ret < 0 ) {
1366 ERR("Restarting the worker process failed");
1367 ret = -1;
1368 goto err;
1369 }
1370 err:
1371 return ret;
1372 }
1373
1374 static
1375 int run_as(enum run_as_cmd cmd, struct run_as_data *data,
1376 struct run_as_ret *ret_value, uid_t uid, gid_t gid)
1377 {
1378 int ret, saved_errno;
1379
1380 pthread_mutex_lock(&worker_lock);
1381 if (use_clone()) {
1382 DBG("Using run_as worker");
1383
1384 assert(global_worker);
1385
1386 ret = run_as_cmd(global_worker, cmd, data, ret_value, uid, gid);
1387 saved_errno = ret_value->_errno;
1388
1389 /*
1390 * If the worker thread crashed the errno is set to EIO. we log
1391 * the error and start a new worker process.
1392 */
1393 if (ret == -1 && saved_errno == EIO) {
1394 DBG("Socket closed unexpectedly... "
1395 "Restarting the worker process");
1396 ret = run_as_restart_worker(global_worker);
1397 if (ret == -1) {
1398 ERR("Failed to restart worker process.");
1399 goto err;
1400 }
1401 }
1402 } else {
1403 DBG("Using run_as without worker");
1404 ret = run_as_noworker(cmd, data, ret_value, uid, gid);
1405 }
1406 err:
1407 pthread_mutex_unlock(&worker_lock);
1408 return ret;
1409 }
1410
1411 LTTNG_HIDDEN
1412 int run_as_mkdir_recursive(const char *path, mode_t mode, uid_t uid, gid_t gid)
1413 {
1414 return run_as_mkdirat_recursive(AT_FDCWD, path, mode, uid, gid);
1415 }
1416
1417 LTTNG_HIDDEN
1418 int run_as_mkdirat_recursive(int dirfd, const char *path, mode_t mode,
1419 uid_t uid, gid_t gid)
1420 {
1421 int ret;
1422 struct run_as_data data = {};
1423 struct run_as_ret run_as_ret = {};
1424
1425 DBG3("mkdirat() recursive fd = %d%s, path = %s, mode = %d, uid = %d, gid = %d",
1426 dirfd, dirfd == AT_FDCWD ? " (AT_FDCWD)" : "",
1427 path, (int) mode, (int) uid, (int) gid);
1428 ret = lttng_strncpy(data.u.mkdir.path, path,
1429 sizeof(data.u.mkdir.path));
1430 if (ret) {
1431 ERR("Failed to copy path argument of mkdirat recursive command");
1432 goto error;
1433 }
1434 data.u.mkdir.path[sizeof(data.u.mkdir.path) - 1] = '\0';
1435 data.u.mkdir.mode = mode;
1436 data.u.mkdir.dirfd = dirfd;
1437 run_as(dirfd == AT_FDCWD ? RUN_AS_MKDIR_RECURSIVE : RUN_AS_MKDIRAT_RECURSIVE,
1438 &data, &run_as_ret, uid, gid);
1439 errno = run_as_ret._errno;
1440 ret = run_as_ret.u.ret;
1441 error:
1442 return ret;
1443 }
1444
1445 LTTNG_HIDDEN
1446 int run_as_mkdir(const char *path, mode_t mode, uid_t uid, gid_t gid)
1447 {
1448 return run_as_mkdirat(AT_FDCWD, path, mode, uid, gid);
1449 }
1450
1451 LTTNG_HIDDEN
1452 int run_as_mkdirat(int dirfd, const char *path, mode_t mode,
1453 uid_t uid, gid_t gid)
1454 {
1455 int ret;
1456 struct run_as_data data = {};
1457 struct run_as_ret run_as_ret = {};
1458
1459 DBG3("mkdirat() recursive fd = %d%s, path = %s, mode = %d, uid = %d, gid = %d",
1460 dirfd, dirfd == AT_FDCWD ? " (AT_FDCWD)" : "",
1461 path, (int) mode, (int) uid, (int) gid);
1462 ret = lttng_strncpy(data.u.mkdir.path, path,
1463 sizeof(data.u.mkdir.path));
1464 if (ret) {
1465 ERR("Failed to copy path argument of mkdirat command");
1466 goto error;
1467 }
1468 data.u.mkdir.path[sizeof(data.u.mkdir.path) - 1] = '\0';
1469 data.u.mkdir.mode = mode;
1470 data.u.mkdir.dirfd = dirfd;
1471 run_as(dirfd == AT_FDCWD ? RUN_AS_MKDIR : RUN_AS_MKDIRAT,
1472 &data, &run_as_ret, uid, gid);
1473 errno = run_as_ret._errno;
1474 ret = run_as_ret.u.ret;
1475 error:
1476 return ret;
1477 }
1478
1479 LTTNG_HIDDEN
1480 int run_as_open(const char *path, int flags, mode_t mode, uid_t uid,
1481 gid_t gid)
1482 {
1483 return run_as_openat(AT_FDCWD, path, flags, mode, uid, gid);
1484 }
1485
1486 LTTNG_HIDDEN
1487 int run_as_openat(int dirfd, const char *path, int flags, mode_t mode,
1488 uid_t uid, gid_t gid)
1489 {
1490 int ret;
1491 struct run_as_data data = {};
1492 struct run_as_ret run_as_ret = {};
1493
1494 DBG3("openat() fd = %d%s, path = %s, flags = %X, mode = %d, uid %d, gid %d",
1495 dirfd, dirfd == AT_FDCWD ? " (AT_FDCWD)" : "",
1496 path, flags, (int) mode, (int) uid, (int) gid);
1497 ret = lttng_strncpy(data.u.open.path, path, sizeof(data.u.open.path));
1498 if (ret) {
1499 ERR("Failed to copy path argument of open command");
1500 goto error;
1501 }
1502 data.u.open.flags = flags;
1503 data.u.open.mode = mode;
1504 data.u.open.dirfd = dirfd;
1505 run_as(dirfd == AT_FDCWD ? RUN_AS_OPEN : RUN_AS_OPENAT,
1506 &data, &run_as_ret, uid, gid);
1507 errno = run_as_ret._errno;
1508 ret = run_as_ret.u.ret < 0 ? run_as_ret.u.ret :
1509 run_as_ret.u.open.fd;
1510 error:
1511 return ret;
1512 }
1513
1514 LTTNG_HIDDEN
1515 int run_as_unlink(const char *path, uid_t uid, gid_t gid)
1516 {
1517 return run_as_unlinkat(AT_FDCWD, path, uid, gid);
1518 }
1519
1520 LTTNG_HIDDEN
1521 int run_as_unlinkat(int dirfd, const char *path, uid_t uid, gid_t gid)
1522 {
1523 int ret;
1524 struct run_as_data data = {};
1525 struct run_as_ret run_as_ret = {};
1526
1527 DBG3("unlinkat() fd = %d%s, path = %s, uid = %d, gid = %d",
1528 dirfd, dirfd == AT_FDCWD ? " (AT_FDCWD)" : "",
1529 path, (int) uid, (int) gid);
1530 ret = lttng_strncpy(data.u.unlink.path, path,
1531 sizeof(data.u.unlink.path));
1532 if (ret) {
1533 goto error;
1534 }
1535 data.u.unlink.dirfd = dirfd;
1536 run_as(dirfd == AT_FDCWD ? RUN_AS_UNLINK : RUN_AS_UNLINKAT, &data,
1537 &run_as_ret, uid, gid);
1538 errno = run_as_ret._errno;
1539 ret = run_as_ret.u.ret;
1540 error:
1541 return ret;
1542 }
1543
1544 LTTNG_HIDDEN
1545 int run_as_rmdir(const char *path, uid_t uid, gid_t gid)
1546 {
1547 return run_as_rmdirat(AT_FDCWD, path, uid, gid);
1548 }
1549
1550 LTTNG_HIDDEN
1551 int run_as_rmdirat(int dirfd, const char *path, uid_t uid, gid_t gid)
1552 {
1553 int ret;
1554 struct run_as_data data = {};
1555 struct run_as_ret run_as_ret = {};
1556
1557 DBG3("rmdirat() fd = %d%s, path = %s, uid = %d, gid = %d",
1558 dirfd, dirfd == AT_FDCWD ? " (AT_FDCWD)" : "",
1559 path, (int) uid, (int) gid);
1560 ret = lttng_strncpy(data.u.rmdir.path, path,
1561 sizeof(data.u.rmdir.path));
1562 if (ret) {
1563 goto error;
1564 }
1565 data.u.rmdir.dirfd = dirfd;
1566 run_as(dirfd == AT_FDCWD ? RUN_AS_RMDIR : RUN_AS_RMDIRAT, &data,
1567 &run_as_ret, uid, gid);
1568 errno = run_as_ret._errno;
1569 ret = run_as_ret.u.ret;
1570 error:
1571 return ret;
1572 }
1573
1574 LTTNG_HIDDEN
1575 int run_as_rmdir_recursive(const char *path, uid_t uid, gid_t gid, int flags)
1576 {
1577 return run_as_rmdirat_recursive(AT_FDCWD, path, uid, gid, flags);
1578 }
1579
1580 LTTNG_HIDDEN
1581 int run_as_rmdirat_recursive(int dirfd, const char *path, uid_t uid, gid_t gid, int flags)
1582 {
1583 int ret;
1584 struct run_as_data data = {};
1585 struct run_as_ret run_as_ret = {};
1586
1587 DBG3("rmdirat() recursive fd = %d%s, path = %s, uid = %d, gid = %d",
1588 dirfd, dirfd == AT_FDCWD ? " (AT_FDCWD)" : "",
1589 path, (int) uid, (int) gid);
1590 ret = lttng_strncpy(data.u.rmdir.path, path,
1591 sizeof(data.u.rmdir.path));
1592 if (ret) {
1593 goto error;
1594 }
1595 data.u.rmdir.dirfd = dirfd;
1596 data.u.rmdir.flags = flags;
1597 run_as(dirfd == AT_FDCWD ? RUN_AS_RMDIR_RECURSIVE : RUN_AS_RMDIRAT_RECURSIVE,
1598 &data, &run_as_ret, uid, gid);
1599 errno = run_as_ret._errno;
1600 ret = run_as_ret.u.ret;
1601 error:
1602 return ret;
1603 }
1604
1605 LTTNG_HIDDEN
1606 int run_as_rename(const char *old, const char *new, uid_t uid, gid_t gid)
1607 {
1608 return run_as_renameat(AT_FDCWD, old, AT_FDCWD, new, uid, gid);
1609 }
1610
1611 LTTNG_HIDDEN
1612 int run_as_renameat(int old_dirfd, const char *old_name,
1613 int new_dirfd, const char *new_name, uid_t uid, gid_t gid)
1614 {
1615 int ret;
1616 struct run_as_data data = {};
1617 struct run_as_ret run_as_ret = {};
1618
1619 DBG3("renameat() old_dirfd = %d%s, old_name = %s, new_dirfd = %d%s, new_name = %s, uid = %d, gid = %d",
1620 old_dirfd, old_dirfd == AT_FDCWD ? " (AT_FDCWD)" : "",
1621 old_name,
1622 new_dirfd, new_dirfd == AT_FDCWD ? " (AT_FDCWD)" : "",
1623 new_name, (int) uid, (int) gid);
1624 ret = lttng_strncpy(data.u.rename.old_path, old_name,
1625 sizeof(data.u.rename.old_path));
1626 if (ret) {
1627 goto error;
1628 }
1629 ret = lttng_strncpy(data.u.rename.new_path, new_name,
1630 sizeof(data.u.rename.new_path));
1631 if (ret) {
1632 goto error;
1633 }
1634
1635 data.u.rename.dirfds[0] = old_dirfd;
1636 data.u.rename.dirfds[1] = new_dirfd;
1637 run_as(old_dirfd == AT_FDCWD && new_dirfd == AT_FDCWD ?
1638 RUN_AS_RENAME : RUN_AS_RENAMEAT,
1639 &data, &run_as_ret, uid, gid);
1640 errno = run_as_ret._errno;
1641 ret = run_as_ret.u.ret;
1642 error:
1643 return ret;
1644 }
1645
1646 LTTNG_HIDDEN
1647 int run_as_extract_elf_symbol_offset(int fd, const char* function,
1648 uid_t uid, gid_t gid, uint64_t *offset)
1649 {
1650 int ret;
1651 struct run_as_data data = {};
1652 struct run_as_ret run_as_ret = {};
1653
1654 DBG3("extract_elf_symbol_offset() on fd=%d and function=%s "
1655 "with for uid %d and gid %d", fd, function,
1656 (int) uid, (int) gid);
1657
1658 data.u.extract_elf_symbol_offset.fd = fd;
1659
1660 strncpy(data.u.extract_elf_symbol_offset.function, function, LTTNG_SYMBOL_NAME_LEN - 1);
1661 data.u.extract_elf_symbol_offset.function[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
1662 ret = lttng_strncpy(data.u.extract_elf_symbol_offset.function,
1663 function,
1664 sizeof(data.u.extract_elf_symbol_offset.function));
1665 if (ret) {
1666 goto error;
1667 }
1668
1669 run_as(RUN_AS_EXTRACT_ELF_SYMBOL_OFFSET, &data, &run_as_ret, uid, gid);
1670 errno = run_as_ret._errno;
1671 if (run_as_ret._error) {
1672 ret = -1;
1673 goto error;
1674 }
1675
1676 *offset = run_as_ret.u.extract_elf_symbol_offset.offset;
1677 error:
1678 return ret;
1679 }
1680
1681 LTTNG_HIDDEN
1682 int run_as_extract_sdt_probe_offsets(int fd, const char* provider_name,
1683 const char* probe_name, uid_t uid, gid_t gid,
1684 uint64_t **offsets, uint32_t *num_offset)
1685 {
1686 int ret;
1687 struct run_as_data data = {};
1688 struct run_as_ret run_as_ret = {};
1689
1690 DBG3("extract_sdt_probe_offsets() on fd=%d, probe_name=%s and "
1691 "provider_name=%s with for uid %d and gid %d", fd,
1692 probe_name, provider_name, (int) uid, (int) gid);
1693
1694 data.u.extract_sdt_probe_offsets.fd = fd;
1695
1696 ret = lttng_strncpy(data.u.extract_sdt_probe_offsets.probe_name, probe_name,
1697 sizeof(data.u.extract_sdt_probe_offsets.probe_name));
1698 if (ret) {
1699 goto error;
1700 }
1701 ret = lttng_strncpy(data.u.extract_sdt_probe_offsets.provider_name,
1702 provider_name,
1703 sizeof(data.u.extract_sdt_probe_offsets.provider_name));
1704 if (ret) {
1705 goto error;
1706 }
1707
1708 run_as(RUN_AS_EXTRACT_SDT_PROBE_OFFSETS, &data, &run_as_ret, uid, gid);
1709 errno = run_as_ret._errno;
1710 if (run_as_ret._error) {
1711 ret = -1;
1712 goto error;
1713 }
1714
1715 *num_offset = run_as_ret.u.extract_sdt_probe_offsets.num_offset;
1716 *offsets = zmalloc(*num_offset * sizeof(uint64_t));
1717 if (!*offsets) {
1718 ret = -ENOMEM;
1719 goto error;
1720 }
1721
1722 memcpy(*offsets, run_as_ret.u.extract_sdt_probe_offsets.offsets,
1723 *num_offset * sizeof(uint64_t));
1724 error:
1725 return ret;
1726 }
1727
1728 LTTNG_HIDDEN
1729 int run_as_create_worker(const char *procname,
1730 post_fork_cleanup_cb clean_up_func,
1731 void *clean_up_user_data)
1732 {
1733 int ret;
1734
1735 pthread_mutex_lock(&worker_lock);
1736 ret = run_as_create_worker_no_lock(procname, clean_up_func,
1737 clean_up_user_data);
1738 pthread_mutex_unlock(&worker_lock);
1739 return ret;
1740 }
1741
1742 LTTNG_HIDDEN
1743 void run_as_destroy_worker(void)
1744 {
1745 pthread_mutex_lock(&worker_lock);
1746 run_as_destroy_worker_no_lock();
1747 pthread_mutex_unlock(&worker_lock);
1748 }
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