Port: Explicitly allocate realpath() resolved buffer
[lttng-tools.git] / src / common / utils.c
1 /*
2 * Copyright (C) 2012 - David Goulet <dgoulet@efficios.com>
3 * Copyright (C) 2013 - Raphaël Beamonte <raphael.beamonte@gmail.com>
4 * Copyright (C) 2013 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License, version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
13 * more details.
14 *
15 * You should have received a copy of the GNU General Public License along with
16 * this program; if not, write to the Free Software Foundation, Inc., 51
17 * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
18 */
19
20 #define _LGPL_SOURCE
21 #include <assert.h>
22 #include <ctype.h>
23 #include <fcntl.h>
24 #include <limits.h>
25 #include <stdlib.h>
26 #include <sys/stat.h>
27 #include <sys/types.h>
28 #include <unistd.h>
29 #include <inttypes.h>
30 #include <grp.h>
31 #include <pwd.h>
32 #include <sys/file.h>
33
34 #include <common/common.h>
35 #include <common/runas.h>
36 #include <common/compat/getenv.h>
37 #include <common/compat/string.h>
38 #include <common/compat/dirent.h>
39 #include <lttng/constant.h>
40
41 #include "utils.h"
42 #include "defaults.h"
43
44 /*
45 * Return a partial realpath(3) of the path even if the full path does not
46 * exist. For instance, with /tmp/test1/test2/test3, if test2/ does not exist
47 * but the /tmp/test1 does, the real path for /tmp/test1 is concatened with
48 * /test2/test3 then returned. In normal time, realpath(3) fails if the end
49 * point directory does not exist.
50 * In case resolved_path is NULL, the string returned was allocated in the
51 * function and thus need to be freed by the caller. The size argument allows
52 * to specify the size of the resolved_path argument if given, or the size to
53 * allocate.
54 */
55 LTTNG_HIDDEN
56 char *utils_partial_realpath(const char *path, char *resolved_path, size_t size)
57 {
58 char *cut_path = NULL, *try_path = NULL, *try_path_prev = NULL;
59 const char *next, *prev, *end;
60
61 /* Safety net */
62 if (path == NULL) {
63 goto error;
64 }
65
66 /*
67 * Identify the end of the path, we don't want to treat the
68 * last char if it is a '/', we will just keep it on the side
69 * to be added at the end, and return a value coherent with
70 * the path given as argument
71 */
72 end = path + strlen(path);
73 if (*(end-1) == '/') {
74 end--;
75 }
76
77 /* Initiate the values of the pointers before looping */
78 next = path;
79 prev = next;
80 /* Only to ensure try_path is not NULL to enter the while */
81 try_path = (char *)next;
82
83 /* Resolve the canonical path of the first part of the path */
84 while (try_path != NULL && next != end) {
85 char *try_path_buf = NULL;
86
87 /*
88 * If there is not any '/' left, we want to try with
89 * the full path
90 */
91 next = strpbrk(next + 1, "/");
92 if (next == NULL) {
93 next = end;
94 }
95
96 /* Cut the part we will be trying to resolve */
97 cut_path = lttng_strndup(path, next - path);
98 if (cut_path == NULL) {
99 PERROR("lttng_strndup");
100 goto error;
101 }
102
103 try_path_buf = zmalloc(LTTNG_PATH_MAX);
104 if (!try_path_buf) {
105 PERROR("zmalloc");
106 goto error;
107 }
108
109 /* Try to resolve this part */
110 try_path = realpath((char *)cut_path, try_path_buf);
111 if (try_path == NULL) {
112 free(try_path_buf);
113 /*
114 * There was an error, we just want to be assured it
115 * is linked to an unexistent directory, if it's another
116 * reason, we spawn an error
117 */
118 switch (errno) {
119 case ENOENT:
120 /* Ignore the error */
121 break;
122 default:
123 PERROR("realpath (partial_realpath)");
124 goto error;
125 break;
126 }
127 } else {
128 /* Save the place we are before trying the next step */
129 try_path_buf = NULL;
130 free(try_path_prev);
131 try_path_prev = try_path;
132 prev = next;
133 }
134
135 /* Free the allocated memory */
136 free(cut_path);
137 cut_path = NULL;
138 }
139
140 /* Allocate memory for the resolved path if necessary */
141 if (resolved_path == NULL) {
142 resolved_path = zmalloc(size);
143 if (resolved_path == NULL) {
144 PERROR("zmalloc resolved path");
145 goto error;
146 }
147 }
148
149 /*
150 * If we were able to solve at least partially the path, we can concatenate
151 * what worked and what didn't work
152 */
153 if (try_path_prev != NULL) {
154 /* If we risk to concatenate two '/', we remove one of them */
155 if (try_path_prev[strlen(try_path_prev) - 1] == '/' && prev[0] == '/') {
156 try_path_prev[strlen(try_path_prev) - 1] = '\0';
157 }
158
159 /*
160 * Duplicate the memory used by prev in case resolved_path and
161 * path are pointers for the same memory space
162 */
163 cut_path = strdup(prev);
164 if (cut_path == NULL) {
165 PERROR("strdup");
166 goto error;
167 }
168
169 /* Concatenate the strings */
170 snprintf(resolved_path, size, "%s%s", try_path_prev, cut_path);
171
172 /* Free the allocated memory */
173 free(cut_path);
174 free(try_path_prev);
175 cut_path = NULL;
176 try_path_prev = NULL;
177 /*
178 * Else, we just copy the path in our resolved_path to
179 * return it as is
180 */
181 } else {
182 strncpy(resolved_path, path, size);
183 }
184
185 /* Then we return the 'partially' resolved path */
186 return resolved_path;
187
188 error:
189 free(resolved_path);
190 free(cut_path);
191 return NULL;
192 }
193
194 /*
195 * Make a full resolution of the given path even if it doesn't exist.
196 * This function uses the utils_partial_realpath function to resolve
197 * symlinks and relatives paths at the start of the string, and
198 * implements functionnalities to resolve the './' and '../' strings
199 * in the middle of a path. This function is only necessary because
200 * realpath(3) does not accept to resolve unexistent paths.
201 * The returned string was allocated in the function, it is thus of
202 * the responsibility of the caller to free this memory.
203 */
204 LTTNG_HIDDEN
205 char *utils_expand_path(const char *path)
206 {
207 char *next, *previous, *slash, *start_path, *absolute_path = NULL;
208 char *last_token;
209 int is_dot, is_dotdot;
210
211 /* Safety net */
212 if (path == NULL) {
213 goto error;
214 }
215
216 /* Allocate memory for the absolute_path */
217 absolute_path = zmalloc(PATH_MAX);
218 if (absolute_path == NULL) {
219 PERROR("zmalloc expand path");
220 goto error;
221 }
222
223 /*
224 * If the path is not already absolute nor explicitly relative,
225 * consider we're in the current directory
226 */
227 if (*path != '/' && strncmp(path, "./", 2) != 0 &&
228 strncmp(path, "../", 3) != 0) {
229 snprintf(absolute_path, PATH_MAX, "./%s", path);
230 /* Else, we just copy the path */
231 } else {
232 strncpy(absolute_path, path, PATH_MAX);
233 }
234
235 /* Resolve partially our path */
236 absolute_path = utils_partial_realpath(absolute_path,
237 absolute_path, PATH_MAX);
238
239 /* As long as we find '/./' in the working_path string */
240 while ((next = strstr(absolute_path, "/./"))) {
241
242 /* We prepare the start_path not containing it */
243 start_path = lttng_strndup(absolute_path, next - absolute_path);
244 if (!start_path) {
245 PERROR("lttng_strndup");
246 goto error;
247 }
248 /* And we concatenate it with the part after this string */
249 snprintf(absolute_path, PATH_MAX, "%s%s", start_path, next + 2);
250
251 free(start_path);
252 }
253
254 /* As long as we find '/../' in the working_path string */
255 while ((next = strstr(absolute_path, "/../"))) {
256 /* We find the last level of directory */
257 previous = absolute_path;
258 while ((slash = strpbrk(previous, "/")) && slash != next) {
259 previous = slash + 1;
260 }
261
262 /* Then we prepare the start_path not containing it */
263 start_path = lttng_strndup(absolute_path, previous - absolute_path);
264 if (!start_path) {
265 PERROR("lttng_strndup");
266 goto error;
267 }
268
269 /* And we concatenate it with the part after the '/../' */
270 snprintf(absolute_path, PATH_MAX, "%s%s", start_path, next + 4);
271
272 /* We can free the memory used for the start path*/
273 free(start_path);
274
275 /* Then we verify for symlinks using partial_realpath */
276 absolute_path = utils_partial_realpath(absolute_path,
277 absolute_path, PATH_MAX);
278 }
279
280 /* Identify the last token */
281 last_token = strrchr(absolute_path, '/');
282
283 /* Verify that this token is not a relative path */
284 is_dotdot = (strcmp(last_token, "/..") == 0);
285 is_dot = (strcmp(last_token, "/.") == 0);
286
287 /* If it is, take action */
288 if (is_dot || is_dotdot) {
289 /* For both, remove this token */
290 *last_token = '\0';
291
292 /* If it was a reference to parent directory, go back one more time */
293 if (is_dotdot) {
294 last_token = strrchr(absolute_path, '/');
295
296 /* If there was only one level left, we keep the first '/' */
297 if (last_token == absolute_path) {
298 last_token++;
299 }
300
301 *last_token = '\0';
302 }
303 }
304
305 return absolute_path;
306
307 error:
308 free(absolute_path);
309 return NULL;
310 }
311
312 /*
313 * Create a pipe in dst.
314 */
315 LTTNG_HIDDEN
316 int utils_create_pipe(int *dst)
317 {
318 int ret;
319
320 if (dst == NULL) {
321 return -1;
322 }
323
324 ret = pipe(dst);
325 if (ret < 0) {
326 PERROR("create pipe");
327 }
328
329 return ret;
330 }
331
332 /*
333 * Create pipe and set CLOEXEC flag to both fd.
334 *
335 * Make sure the pipe opened by this function are closed at some point. Use
336 * utils_close_pipe().
337 */
338 LTTNG_HIDDEN
339 int utils_create_pipe_cloexec(int *dst)
340 {
341 int ret, i;
342
343 if (dst == NULL) {
344 return -1;
345 }
346
347 ret = utils_create_pipe(dst);
348 if (ret < 0) {
349 goto error;
350 }
351
352 for (i = 0; i < 2; i++) {
353 ret = fcntl(dst[i], F_SETFD, FD_CLOEXEC);
354 if (ret < 0) {
355 PERROR("fcntl pipe cloexec");
356 goto error;
357 }
358 }
359
360 error:
361 return ret;
362 }
363
364 /*
365 * Create pipe and set fd flags to FD_CLOEXEC and O_NONBLOCK.
366 *
367 * Make sure the pipe opened by this function are closed at some point. Use
368 * utils_close_pipe(). Using pipe() and fcntl rather than pipe2() to
369 * support OSes other than Linux 2.6.23+.
370 */
371 LTTNG_HIDDEN
372 int utils_create_pipe_cloexec_nonblock(int *dst)
373 {
374 int ret, i;
375
376 if (dst == NULL) {
377 return -1;
378 }
379
380 ret = utils_create_pipe(dst);
381 if (ret < 0) {
382 goto error;
383 }
384
385 for (i = 0; i < 2; i++) {
386 ret = fcntl(dst[i], F_SETFD, FD_CLOEXEC);
387 if (ret < 0) {
388 PERROR("fcntl pipe cloexec");
389 goto error;
390 }
391 /*
392 * Note: we override any flag that could have been
393 * previously set on the fd.
394 */
395 ret = fcntl(dst[i], F_SETFL, O_NONBLOCK);
396 if (ret < 0) {
397 PERROR("fcntl pipe nonblock");
398 goto error;
399 }
400 }
401
402 error:
403 return ret;
404 }
405
406 /*
407 * Close both read and write side of the pipe.
408 */
409 LTTNG_HIDDEN
410 void utils_close_pipe(int *src)
411 {
412 int i, ret;
413
414 if (src == NULL) {
415 return;
416 }
417
418 for (i = 0; i < 2; i++) {
419 /* Safety check */
420 if (src[i] < 0) {
421 continue;
422 }
423
424 ret = close(src[i]);
425 if (ret) {
426 PERROR("close pipe");
427 }
428 }
429 }
430
431 /*
432 * Create a new string using two strings range.
433 */
434 LTTNG_HIDDEN
435 char *utils_strdupdelim(const char *begin, const char *end)
436 {
437 char *str;
438
439 str = zmalloc(end - begin + 1);
440 if (str == NULL) {
441 PERROR("zmalloc strdupdelim");
442 goto error;
443 }
444
445 memcpy(str, begin, end - begin);
446 str[end - begin] = '\0';
447
448 error:
449 return str;
450 }
451
452 /*
453 * Set CLOEXEC flag to the give file descriptor.
454 */
455 LTTNG_HIDDEN
456 int utils_set_fd_cloexec(int fd)
457 {
458 int ret;
459
460 if (fd < 0) {
461 ret = -EINVAL;
462 goto end;
463 }
464
465 ret = fcntl(fd, F_SETFD, FD_CLOEXEC);
466 if (ret < 0) {
467 PERROR("fcntl cloexec");
468 ret = -errno;
469 }
470
471 end:
472 return ret;
473 }
474
475 /*
476 * Create pid file to the given path and filename.
477 */
478 LTTNG_HIDDEN
479 int utils_create_pid_file(pid_t pid, const char *filepath)
480 {
481 int ret;
482 FILE *fp;
483
484 assert(filepath);
485
486 fp = fopen(filepath, "w");
487 if (fp == NULL) {
488 PERROR("open pid file %s", filepath);
489 ret = -1;
490 goto error;
491 }
492
493 ret = fprintf(fp, "%d\n", (int) pid);
494 if (ret < 0) {
495 PERROR("fprintf pid file");
496 goto error;
497 }
498
499 if (fclose(fp)) {
500 PERROR("fclose");
501 }
502 DBG("Pid %d written in file %s", (int) pid, filepath);
503 ret = 0;
504 error:
505 return ret;
506 }
507
508 /*
509 * Create lock file to the given path and filename.
510 * Returns the associated file descriptor, -1 on error.
511 */
512 LTTNG_HIDDEN
513 int utils_create_lock_file(const char *filepath)
514 {
515 int ret;
516 int fd;
517 struct flock lock;
518
519 assert(filepath);
520
521 memset(&lock, 0, sizeof(lock));
522 fd = open(filepath, O_CREAT | O_WRONLY, S_IRUSR | S_IWUSR |
523 S_IRGRP | S_IWGRP);
524 if (fd < 0) {
525 PERROR("open lock file %s", filepath);
526 ret = -1;
527 goto error;
528 }
529
530 /*
531 * Attempt to lock the file. If this fails, there is
532 * already a process using the same lock file running
533 * and we should exit.
534 */
535 lock.l_whence = SEEK_SET;
536 lock.l_type = F_WRLCK;
537
538 ret = fcntl(fd, F_SETLK, &lock);
539 if (ret == -1) {
540 PERROR("fcntl lock file");
541 ERR("Could not get lock file %s, another instance is running.",
542 filepath);
543 if (close(fd)) {
544 PERROR("close lock file");
545 }
546 fd = ret;
547 goto error;
548 }
549
550 error:
551 return fd;
552 }
553
554 /*
555 * Create directory using the given path and mode.
556 *
557 * On success, return 0 else a negative error code.
558 */
559 LTTNG_HIDDEN
560 int utils_mkdir(const char *path, mode_t mode, int uid, int gid)
561 {
562 int ret;
563
564 if (uid < 0 || gid < 0) {
565 ret = mkdir(path, mode);
566 } else {
567 ret = run_as_mkdir(path, mode, uid, gid);
568 }
569 if (ret < 0) {
570 if (errno != EEXIST) {
571 PERROR("mkdir %s, uid %d, gid %d", path ? path : "NULL",
572 uid, gid);
573 } else {
574 ret = 0;
575 }
576 }
577
578 return ret;
579 }
580
581 /*
582 * Internal version of mkdir_recursive. Runs as the current user.
583 * Don't call directly; use utils_mkdir_recursive().
584 *
585 * This function is ominously marked as "unsafe" since it should only
586 * be called by a caller that has transitioned to the uid and gid under which
587 * the directory creation should occur.
588 */
589 LTTNG_HIDDEN
590 int _utils_mkdir_recursive_unsafe(const char *path, mode_t mode)
591 {
592 char *p, tmp[PATH_MAX];
593 size_t len;
594 int ret;
595
596 assert(path);
597
598 ret = snprintf(tmp, sizeof(tmp), "%s", path);
599 if (ret < 0) {
600 PERROR("snprintf mkdir");
601 goto error;
602 }
603
604 len = ret;
605 if (tmp[len - 1] == '/') {
606 tmp[len - 1] = 0;
607 }
608
609 for (p = tmp + 1; *p; p++) {
610 if (*p == '/') {
611 *p = 0;
612 if (tmp[strlen(tmp) - 1] == '.' &&
613 tmp[strlen(tmp) - 2] == '.' &&
614 tmp[strlen(tmp) - 3] == '/') {
615 ERR("Using '/../' is not permitted in the trace path (%s)",
616 tmp);
617 ret = -1;
618 goto error;
619 }
620 ret = mkdir(tmp, mode);
621 if (ret < 0) {
622 if (errno != EEXIST) {
623 PERROR("mkdir recursive");
624 ret = -errno;
625 goto error;
626 }
627 }
628 *p = '/';
629 }
630 }
631
632 ret = mkdir(tmp, mode);
633 if (ret < 0) {
634 if (errno != EEXIST) {
635 PERROR("mkdir recursive last element");
636 ret = -errno;
637 } else {
638 ret = 0;
639 }
640 }
641
642 error:
643 return ret;
644 }
645
646 /*
647 * Recursively create directory using the given path and mode, under the
648 * provided uid and gid.
649 *
650 * On success, return 0 else a negative error code.
651 */
652 LTTNG_HIDDEN
653 int utils_mkdir_recursive(const char *path, mode_t mode, int uid, int gid)
654 {
655 int ret;
656
657 if (uid < 0 || gid < 0) {
658 /* Run as current user. */
659 ret = _utils_mkdir_recursive_unsafe(path, mode);
660 } else {
661 ret = run_as_mkdir_recursive(path, mode, uid, gid);
662 }
663 if (ret < 0) {
664 PERROR("mkdir %s, uid %d, gid %d", path ? path : "NULL",
665 uid, gid);
666 }
667
668 return ret;
669 }
670
671 /*
672 * path is the output parameter. It needs to be PATH_MAX len.
673 *
674 * Return 0 on success or else a negative value.
675 */
676 static int utils_stream_file_name(char *path,
677 const char *path_name, const char *file_name,
678 uint64_t size, uint64_t count,
679 const char *suffix)
680 {
681 int ret;
682 char full_path[PATH_MAX];
683 char *path_name_suffix = NULL;
684 char *extra = NULL;
685
686 ret = snprintf(full_path, sizeof(full_path), "%s/%s",
687 path_name, file_name);
688 if (ret < 0) {
689 PERROR("snprintf create output file");
690 goto error;
691 }
692
693 /* Setup extra string if suffix or/and a count is needed. */
694 if (size > 0 && suffix) {
695 ret = asprintf(&extra, "_%" PRIu64 "%s", count, suffix);
696 } else if (size > 0) {
697 ret = asprintf(&extra, "_%" PRIu64, count);
698 } else if (suffix) {
699 ret = asprintf(&extra, "%s", suffix);
700 }
701 if (ret < 0) {
702 PERROR("Allocating extra string to name");
703 goto error;
704 }
705
706 /*
707 * If we split the trace in multiple files, we have to add the count at
708 * the end of the tracefile name.
709 */
710 if (extra) {
711 ret = asprintf(&path_name_suffix, "%s%s", full_path, extra);
712 if (ret < 0) {
713 PERROR("Allocating path name with extra string");
714 goto error_free_suffix;
715 }
716 strncpy(path, path_name_suffix, PATH_MAX - 1);
717 path[PATH_MAX - 1] = '\0';
718 } else {
719 strncpy(path, full_path, PATH_MAX - 1);
720 }
721 path[PATH_MAX - 1] = '\0';
722 ret = 0;
723
724 free(path_name_suffix);
725 error_free_suffix:
726 free(extra);
727 error:
728 return ret;
729 }
730
731 /*
732 * Create the stream file on disk.
733 *
734 * Return 0 on success or else a negative value.
735 */
736 LTTNG_HIDDEN
737 int utils_create_stream_file(const char *path_name, char *file_name, uint64_t size,
738 uint64_t count, int uid, int gid, char *suffix)
739 {
740 int ret, flags, mode;
741 char path[PATH_MAX];
742
743 ret = utils_stream_file_name(path, path_name, file_name,
744 size, count, suffix);
745 if (ret < 0) {
746 goto error;
747 }
748
749 flags = O_WRONLY | O_CREAT | O_TRUNC;
750 /* Open with 660 mode */
751 mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP;
752
753 if (uid < 0 || gid < 0) {
754 ret = open(path, flags, mode);
755 } else {
756 ret = run_as_open(path, flags, mode, uid, gid);
757 }
758 if (ret < 0) {
759 PERROR("open stream path %s", path);
760 }
761 error:
762 return ret;
763 }
764
765 /*
766 * Unlink the stream tracefile from disk.
767 *
768 * Return 0 on success or else a negative value.
769 */
770 LTTNG_HIDDEN
771 int utils_unlink_stream_file(const char *path_name, char *file_name, uint64_t size,
772 uint64_t count, int uid, int gid, char *suffix)
773 {
774 int ret;
775 char path[PATH_MAX];
776
777 ret = utils_stream_file_name(path, path_name, file_name,
778 size, count, suffix);
779 if (ret < 0) {
780 goto error;
781 }
782 if (uid < 0 || gid < 0) {
783 ret = unlink(path);
784 } else {
785 ret = run_as_unlink(path, uid, gid);
786 }
787 if (ret < 0) {
788 goto error;
789 }
790 error:
791 DBG("utils_unlink_stream_file %s returns %d", path, ret);
792 return ret;
793 }
794
795 /*
796 * Change the output tracefile according to the given size and count The
797 * new_count pointer is set during this operation.
798 *
799 * From the consumer, the stream lock MUST be held before calling this function
800 * because we are modifying the stream status.
801 *
802 * Return 0 on success or else a negative value.
803 */
804 LTTNG_HIDDEN
805 int utils_rotate_stream_file(char *path_name, char *file_name, uint64_t size,
806 uint64_t count, int uid, int gid, int out_fd, uint64_t *new_count,
807 int *stream_fd)
808 {
809 int ret;
810
811 assert(new_count);
812 assert(stream_fd);
813
814 ret = close(out_fd);
815 if (ret < 0) {
816 PERROR("Closing tracefile");
817 goto error;
818 }
819
820 if (count > 0) {
821 /*
822 * In tracefile rotation, for the relay daemon we need
823 * to unlink the old file if present, because it may
824 * still be open in reading by the live thread, and we
825 * need to ensure that we do not overwrite the content
826 * between get_index and get_packet. Since we have no
827 * way to verify integrity of the data content compared
828 * to the associated index, we need to ensure the reader
829 * has exclusive access to the file content, and that
830 * the open of the data file is performed in get_index.
831 * Unlinking the old file rather than overwriting it
832 * achieves this.
833 */
834 *new_count = (*new_count + 1) % count;
835 ret = utils_unlink_stream_file(path_name, file_name,
836 size, *new_count, uid, gid, 0);
837 if (ret < 0 && errno != ENOENT) {
838 goto error;
839 }
840 } else {
841 (*new_count)++;
842 }
843
844 ret = utils_create_stream_file(path_name, file_name, size, *new_count,
845 uid, gid, 0);
846 if (ret < 0) {
847 goto error;
848 }
849 *stream_fd = ret;
850
851 /* Success. */
852 ret = 0;
853
854 error:
855 return ret;
856 }
857
858
859 /**
860 * Parse a string that represents a size in human readable format. It
861 * supports decimal integers suffixed by 'k', 'K', 'M' or 'G'.
862 *
863 * The suffix multiply the integer by:
864 * 'k': 1024
865 * 'M': 1024^2
866 * 'G': 1024^3
867 *
868 * @param str The string to parse.
869 * @param size Pointer to a uint64_t that will be filled with the
870 * resulting size.
871 *
872 * @return 0 on success, -1 on failure.
873 */
874 LTTNG_HIDDEN
875 int utils_parse_size_suffix(const char * const str, uint64_t * const size)
876 {
877 int ret;
878 uint64_t base_size;
879 long shift = 0;
880 const char *str_end;
881 char *num_end;
882
883 if (!str) {
884 DBG("utils_parse_size_suffix: received a NULL string.");
885 ret = -1;
886 goto end;
887 }
888
889 /* strtoull will accept a negative number, but we don't want to. */
890 if (strchr(str, '-') != NULL) {
891 DBG("utils_parse_size_suffix: invalid size string, should not contain '-'.");
892 ret = -1;
893 goto end;
894 }
895
896 /* str_end will point to the \0 */
897 str_end = str + strlen(str);
898 errno = 0;
899 base_size = strtoull(str, &num_end, 0);
900 if (errno != 0) {
901 PERROR("utils_parse_size_suffix strtoull");
902 ret = -1;
903 goto end;
904 }
905
906 if (num_end == str) {
907 /* strtoull parsed nothing, not good. */
908 DBG("utils_parse_size_suffix: strtoull had nothing good to parse.");
909 ret = -1;
910 goto end;
911 }
912
913 /* Check if a prefix is present. */
914 switch (*num_end) {
915 case 'G':
916 shift = GIBI_LOG2;
917 num_end++;
918 break;
919 case 'M': /* */
920 shift = MEBI_LOG2;
921 num_end++;
922 break;
923 case 'K':
924 case 'k':
925 shift = KIBI_LOG2;
926 num_end++;
927 break;
928 case '\0':
929 break;
930 default:
931 DBG("utils_parse_size_suffix: invalid suffix.");
932 ret = -1;
933 goto end;
934 }
935
936 /* Check for garbage after the valid input. */
937 if (num_end != str_end) {
938 DBG("utils_parse_size_suffix: Garbage after size string.");
939 ret = -1;
940 goto end;
941 }
942
943 *size = base_size << shift;
944
945 /* Check for overflow */
946 if ((*size >> shift) != base_size) {
947 DBG("utils_parse_size_suffix: oops, overflow detected.");
948 ret = -1;
949 goto end;
950 }
951
952 ret = 0;
953 end:
954 return ret;
955 }
956
957 /*
958 * fls: returns the position of the most significant bit.
959 * Returns 0 if no bit is set, else returns the position of the most
960 * significant bit (from 1 to 32 on 32-bit, from 1 to 64 on 64-bit).
961 */
962 #if defined(__i386) || defined(__x86_64)
963 static inline unsigned int fls_u32(uint32_t x)
964 {
965 int r;
966
967 asm("bsrl %1,%0\n\t"
968 "jnz 1f\n\t"
969 "movl $-1,%0\n\t"
970 "1:\n\t"
971 : "=r" (r) : "rm" (x));
972 return r + 1;
973 }
974 #define HAS_FLS_U32
975 #endif
976
977 #ifndef HAS_FLS_U32
978 static __attribute__((unused)) unsigned int fls_u32(uint32_t x)
979 {
980 unsigned int r = 32;
981
982 if (!x) {
983 return 0;
984 }
985 if (!(x & 0xFFFF0000U)) {
986 x <<= 16;
987 r -= 16;
988 }
989 if (!(x & 0xFF000000U)) {
990 x <<= 8;
991 r -= 8;
992 }
993 if (!(x & 0xF0000000U)) {
994 x <<= 4;
995 r -= 4;
996 }
997 if (!(x & 0xC0000000U)) {
998 x <<= 2;
999 r -= 2;
1000 }
1001 if (!(x & 0x80000000U)) {
1002 x <<= 1;
1003 r -= 1;
1004 }
1005 return r;
1006 }
1007 #endif
1008
1009 /*
1010 * Return the minimum order for which x <= (1UL << order).
1011 * Return -1 if x is 0.
1012 */
1013 LTTNG_HIDDEN
1014 int utils_get_count_order_u32(uint32_t x)
1015 {
1016 if (!x) {
1017 return -1;
1018 }
1019
1020 return fls_u32(x - 1);
1021 }
1022
1023 /**
1024 * Obtain the value of LTTNG_HOME environment variable, if exists.
1025 * Otherwise returns the value of HOME.
1026 */
1027 LTTNG_HIDDEN
1028 char *utils_get_home_dir(void)
1029 {
1030 char *val = NULL;
1031 struct passwd *pwd;
1032
1033 val = lttng_secure_getenv(DEFAULT_LTTNG_HOME_ENV_VAR);
1034 if (val != NULL) {
1035 goto end;
1036 }
1037 val = lttng_secure_getenv(DEFAULT_LTTNG_FALLBACK_HOME_ENV_VAR);
1038 if (val != NULL) {
1039 goto end;
1040 }
1041
1042 /* Fallback on the password file entry. */
1043 pwd = getpwuid(getuid());
1044 if (!pwd) {
1045 goto end;
1046 }
1047 val = pwd->pw_dir;
1048
1049 DBG3("Home directory is '%s'", val);
1050
1051 end:
1052 return val;
1053 }
1054
1055 /**
1056 * Get user's home directory. Dynamically allocated, must be freed
1057 * by the caller.
1058 */
1059 LTTNG_HIDDEN
1060 char *utils_get_user_home_dir(uid_t uid)
1061 {
1062 struct passwd pwd;
1063 struct passwd *result;
1064 char *home_dir = NULL;
1065 char *buf = NULL;
1066 long buflen;
1067 int ret;
1068
1069 buflen = sysconf(_SC_GETPW_R_SIZE_MAX);
1070 if (buflen == -1) {
1071 goto end;
1072 }
1073 retry:
1074 buf = zmalloc(buflen);
1075 if (!buf) {
1076 goto end;
1077 }
1078
1079 ret = getpwuid_r(uid, &pwd, buf, buflen, &result);
1080 if (ret || !result) {
1081 if (ret == ERANGE) {
1082 free(buf);
1083 buflen *= 2;
1084 goto retry;
1085 }
1086 goto end;
1087 }
1088
1089 home_dir = strdup(pwd.pw_dir);
1090 end:
1091 free(buf);
1092 return home_dir;
1093 }
1094
1095 /*
1096 * Obtain the value of LTTNG_KMOD_PROBES environment variable, if exists.
1097 * Otherwise returns NULL.
1098 */
1099 LTTNG_HIDDEN
1100 char *utils_get_kmod_probes_list(void)
1101 {
1102 return lttng_secure_getenv(DEFAULT_LTTNG_KMOD_PROBES);
1103 }
1104
1105 /*
1106 * Obtain the value of LTTNG_EXTRA_KMOD_PROBES environment variable, if
1107 * exists. Otherwise returns NULL.
1108 */
1109 LTTNG_HIDDEN
1110 char *utils_get_extra_kmod_probes_list(void)
1111 {
1112 return lttng_secure_getenv(DEFAULT_LTTNG_EXTRA_KMOD_PROBES);
1113 }
1114
1115 /*
1116 * With the given format, fill dst with the time of len maximum siz.
1117 *
1118 * Return amount of bytes set in the buffer or else 0 on error.
1119 */
1120 LTTNG_HIDDEN
1121 size_t utils_get_current_time_str(const char *format, char *dst, size_t len)
1122 {
1123 size_t ret;
1124 time_t rawtime;
1125 struct tm *timeinfo;
1126
1127 assert(format);
1128 assert(dst);
1129
1130 /* Get date and time for session path */
1131 time(&rawtime);
1132 timeinfo = localtime(&rawtime);
1133 ret = strftime(dst, len, format, timeinfo);
1134 if (ret == 0) {
1135 ERR("Unable to strftime with format %s at dst %p of len %zu", format,
1136 dst, len);
1137 }
1138
1139 return ret;
1140 }
1141
1142 /*
1143 * Return the group ID matching name, else 0 if it cannot be found.
1144 */
1145 LTTNG_HIDDEN
1146 gid_t utils_get_group_id(const char *name)
1147 {
1148 struct group *grp;
1149
1150 grp = getgrnam(name);
1151 if (!grp) {
1152 static volatile int warn_once;
1153
1154 if (!warn_once) {
1155 WARN("No tracing group detected");
1156 warn_once = 1;
1157 }
1158 return 0;
1159 }
1160 return grp->gr_gid;
1161 }
1162
1163 /*
1164 * Return a newly allocated option string. This string is to be used as the
1165 * optstring argument of getopt_long(), see GETOPT(3). opt_count is the number
1166 * of elements in the long_options array. Returns NULL if the string's
1167 * allocation fails.
1168 */
1169 LTTNG_HIDDEN
1170 char *utils_generate_optstring(const struct option *long_options,
1171 size_t opt_count)
1172 {
1173 int i;
1174 size_t string_len = opt_count, str_pos = 0;
1175 char *optstring;
1176
1177 /*
1178 * Compute the necessary string length. One letter per option, two when an
1179 * argument is necessary, and a trailing NULL.
1180 */
1181 for (i = 0; i < opt_count; i++) {
1182 string_len += long_options[i].has_arg ? 1 : 0;
1183 }
1184
1185 optstring = zmalloc(string_len);
1186 if (!optstring) {
1187 goto end;
1188 }
1189
1190 for (i = 0; i < opt_count; i++) {
1191 if (!long_options[i].name) {
1192 /* Got to the trailing NULL element */
1193 break;
1194 }
1195
1196 if (long_options[i].val != '\0') {
1197 optstring[str_pos++] = (char) long_options[i].val;
1198 if (long_options[i].has_arg) {
1199 optstring[str_pos++] = ':';
1200 }
1201 }
1202 }
1203
1204 end:
1205 return optstring;
1206 }
1207
1208 /*
1209 * Try to remove a hierarchy of empty directories, recursively. Don't unlink
1210 * any file. Try to rmdir any empty directory within the hierarchy.
1211 */
1212 LTTNG_HIDDEN
1213 int utils_recursive_rmdir(const char *path)
1214 {
1215 DIR *dir;
1216 size_t path_len;
1217 int dir_fd, ret = 0, closeret, is_empty = 1;
1218 struct dirent *entry;
1219
1220 /* Open directory */
1221 dir = opendir(path);
1222 if (!dir) {
1223 PERROR("Cannot open '%s' path", path);
1224 return -1;
1225 }
1226 dir_fd = lttng_dirfd(dir);
1227 if (dir_fd < 0) {
1228 PERROR("lttng_dirfd");
1229 return -1;
1230 }
1231
1232 path_len = strlen(path);
1233 while ((entry = readdir(dir))) {
1234 if (!strcmp(entry->d_name, ".")
1235 || !strcmp(entry->d_name, ".."))
1236 continue;
1237
1238 struct stat st;
1239 size_t name_len;
1240 char filename[PATH_MAX];
1241
1242 name_len = strlen(entry->d_name);
1243 if (path_len + name_len + 2 > sizeof(filename)) {
1244 ERR("Failed to remove file: path name too long (%s/%s)",
1245 path, entry->d_name);
1246 continue;
1247 }
1248 if (snprintf(filename, sizeof(filename), "%s/%s",
1249 path, entry->d_name) < 0) {
1250 ERR("Failed to format path.");
1251 continue;
1252 }
1253
1254 if (stat(filename, &st)) {
1255 PERROR("stat");
1256 continue;
1257 }
1258
1259 if (S_ISDIR(st.st_mode)) {
1260 char subpath[PATH_MAX];
1261
1262 strncpy(subpath, path, PATH_MAX);
1263 subpath[PATH_MAX - 1] = '\0';
1264 strncat(subpath, "/",
1265 PATH_MAX - strlen(subpath) - 1);
1266 strncat(subpath, entry->d_name,
1267 PATH_MAX - strlen(subpath) - 1);
1268 if (utils_recursive_rmdir(subpath)) {
1269 is_empty = 0;
1270 }
1271 } else if (S_ISREG(st.st_mode)) {
1272 is_empty = 0;
1273 } else {
1274 ret = -EINVAL;
1275 goto end;
1276 }
1277 }
1278 end:
1279 closeret = closedir(dir);
1280 if (closeret) {
1281 PERROR("closedir");
1282 }
1283 if (is_empty) {
1284 DBG3("Attempting rmdir %s", path);
1285 ret = rmdir(path);
1286 }
1287 return ret;
1288 }
This page took 0.13493 seconds and 4 git commands to generate.