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9eb977db KS |
1 | /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ |
2 | ||
3 | /*** | |
4 | This file is part of systemd. | |
5 | ||
6 | Copyright 2010-2012 Lennart Poettering | |
7 | ||
8 | systemd is free software; you can redistribute it and/or modify it | |
9 | under the terms of the GNU Lesser General Public License as published by | |
10 | the Free Software Foundation; either version 2.1 of the License, or | |
11 | (at your option) any later version. | |
12 | ||
13 | systemd is distributed in the hope that it will be useful, but | |
14 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
16 | Lesser General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU Lesser General Public License | |
19 | along with systemd; If not, see <http://www.gnu.org/licenses/>. | |
20 | ***/ | |
21 | ||
22 | #include <assert.h> | |
23 | #include <string.h> | |
24 | #include <unistd.h> | |
25 | #include <errno.h> | |
26 | #include <stdlib.h> | |
27 | #include <signal.h> | |
28 | #include <stdio.h> | |
29 | #include <fcntl.h> | |
30 | #include <dirent.h> | |
31 | #include <sys/statvfs.h> | |
32 | ||
33 | #include "macro.h" | |
34 | #include "util.h" | |
35 | #include "log.h" | |
36 | #include "strv.h" | |
37 | #include "path-util.h" | |
a8348796 | 38 | #include "missing.h" |
9eb977db KS |
39 | |
40 | bool path_is_absolute(const char *p) { | |
41 | return p[0] == '/'; | |
42 | } | |
43 | ||
44 | bool is_path(const char *p) { | |
45 | return !!strchr(p, '/'); | |
46 | } | |
47 | ||
9eb977db KS |
48 | int path_get_parent(const char *path, char **_r) { |
49 | const char *e, *a = NULL, *b = NULL, *p; | |
50 | char *r; | |
51 | bool slash = false; | |
52 | ||
53 | assert(path); | |
54 | assert(_r); | |
55 | ||
56 | if (!*path) | |
57 | return -EINVAL; | |
58 | ||
59 | for (e = path; *e; e++) { | |
60 | ||
61 | if (!slash && *e == '/') { | |
62 | a = b; | |
63 | b = e; | |
64 | slash = true; | |
65 | } else if (slash && *e != '/') | |
66 | slash = false; | |
67 | } | |
68 | ||
69 | if (*(e-1) == '/') | |
70 | p = a; | |
71 | else | |
72 | p = b; | |
73 | ||
74 | if (!p) | |
75 | return -EINVAL; | |
76 | ||
77 | if (p == path) | |
78 | r = strdup("/"); | |
79 | else | |
80 | r = strndup(path, p-path); | |
81 | ||
82 | if (!r) | |
83 | return -ENOMEM; | |
84 | ||
85 | *_r = r; | |
86 | return 0; | |
87 | } | |
88 | ||
89 | char **path_split_and_make_absolute(const char *p) { | |
90 | char **l; | |
91 | assert(p); | |
92 | ||
116cc028 ZJS |
93 | l = strv_split(p, ":"); |
94 | if (!l) | |
9eb977db KS |
95 | return NULL; |
96 | ||
97 | if (!path_strv_make_absolute_cwd(l)) { | |
98 | strv_free(l); | |
99 | return NULL; | |
100 | } | |
101 | ||
102 | return l; | |
103 | } | |
104 | ||
105 | char *path_make_absolute(const char *p, const char *prefix) { | |
106 | assert(p); | |
107 | ||
108 | /* Makes every item in the list an absolute path by prepending | |
109 | * the prefix, if specified and necessary */ | |
110 | ||
111 | if (path_is_absolute(p) || !prefix) | |
112 | return strdup(p); | |
113 | ||
b7def684 | 114 | return strjoin(prefix, "/", p, NULL); |
9eb977db KS |
115 | } |
116 | ||
117 | char *path_make_absolute_cwd(const char *p) { | |
116cc028 | 118 | _cleanup_free_ char *cwd = NULL; |
9eb977db KS |
119 | |
120 | assert(p); | |
121 | ||
122 | /* Similar to path_make_absolute(), but prefixes with the | |
123 | * current working directory. */ | |
124 | ||
125 | if (path_is_absolute(p)) | |
126 | return strdup(p); | |
127 | ||
91a6489d LP |
128 | cwd = get_current_dir_name(); |
129 | if (!cwd) | |
9eb977db KS |
130 | return NULL; |
131 | ||
116cc028 | 132 | return path_make_absolute(p, cwd); |
9eb977db KS |
133 | } |
134 | ||
7cb9c51c TK |
135 | int path_make_relative(const char *from_dir, const char *to_path, char **_r) { |
136 | char *r, *p; | |
137 | unsigned n_parents; | |
138 | size_t to_path_len; | |
139 | ||
140 | assert(from_dir); | |
141 | assert(to_path); | |
142 | assert(_r); | |
143 | ||
144 | /* Strips the common part, and adds ".." elements as necessary. */ | |
145 | ||
146 | if (!path_is_absolute(from_dir)) | |
147 | return -EINVAL; | |
148 | ||
149 | if (!path_is_absolute(to_path)) | |
150 | return -EINVAL; | |
151 | ||
152 | /* Skip the common part. */ | |
153 | for (;;) { | |
154 | size_t a; | |
155 | size_t b; | |
156 | ||
157 | from_dir += strspn(from_dir, "/"); | |
158 | to_path += strspn(to_path, "/"); | |
159 | ||
160 | if (!*from_dir) { | |
161 | if (!*to_path) | |
162 | /* from_dir equals to_path. */ | |
163 | r = strdup("."); | |
164 | else | |
165 | /* from_dir is a parent directory of to_path. */ | |
166 | r = strdup(to_path); | |
167 | ||
168 | if (!r) | |
169 | return -ENOMEM; | |
170 | ||
171 | *_r = r; | |
172 | return 0; | |
173 | } | |
174 | ||
175 | if (!*to_path) | |
176 | break; | |
177 | ||
178 | a = strcspn(from_dir, "/"); | |
179 | b = strcspn(to_path, "/"); | |
180 | ||
181 | if (a != b) | |
182 | break; | |
183 | ||
184 | if (memcmp(from_dir, to_path, a) != 0) | |
185 | break; | |
186 | ||
187 | from_dir += a; | |
188 | to_path += b; | |
189 | } | |
190 | ||
191 | /* If we're here, then "from_dir" has one or more elements that need to | |
192 | * be replaced with "..". */ | |
193 | ||
194 | /* Count the number of necessary ".." elements. */ | |
195 | for (n_parents = 0;;) { | |
196 | from_dir += strspn(from_dir, "/"); | |
197 | ||
198 | if (!*from_dir) | |
199 | break; | |
200 | ||
201 | from_dir += strcspn(from_dir, "/"); | |
202 | n_parents++; | |
203 | } | |
204 | ||
205 | to_path_len = strlen(to_path); | |
206 | ||
207 | r = malloc(n_parents * 3 + to_path_len); | |
208 | if (!r) | |
209 | return -ENOMEM; | |
210 | ||
211 | for (p = r; n_parents > 0; n_parents--, p += 3) | |
212 | memcpy(p, "../", 3); | |
213 | ||
214 | if (to_path_len > 0) | |
215 | memcpy(p, to_path, to_path_len); | |
216 | else | |
217 | /* "to_path" is a parent directory of "from_dir". Let's remove | |
218 | * the redundant slash from the end of the result. */ | |
219 | *(p - 1) = 0; | |
220 | ||
221 | *_r = r; | |
222 | return 0; | |
223 | } | |
224 | ||
9eb977db KS |
225 | char **path_strv_make_absolute_cwd(char **l) { |
226 | char **s; | |
227 | ||
228 | /* Goes through every item in the string list and makes it | |
229 | * absolute. This works in place and won't rollback any | |
230 | * changes on failure. */ | |
231 | ||
232 | STRV_FOREACH(s, l) { | |
233 | char *t; | |
234 | ||
116cc028 ZJS |
235 | t = path_make_absolute_cwd(*s); |
236 | if (!t) | |
9eb977db KS |
237 | return NULL; |
238 | ||
239 | free(*s); | |
240 | *s = t; | |
241 | } | |
242 | ||
243 | return l; | |
244 | } | |
245 | ||
112cfb18 | 246 | char **path_strv_canonicalize_absolute(char **l, const char *prefix) { |
9eb977db KS |
247 | char **s; |
248 | unsigned k = 0; | |
249 | bool enomem = false; | |
250 | ||
251 | if (strv_isempty(l)) | |
252 | return l; | |
253 | ||
254 | /* Goes through every item in the string list and canonicalize | |
255 | * the path. This works in place and won't rollback any | |
256 | * changes on failure. */ | |
257 | ||
258 | STRV_FOREACH(s, l) { | |
259 | char *t, *u; | |
12ed81d9 | 260 | _cleanup_free_ char *orig = NULL; |
9eb977db | 261 | |
12ed81d9 ZJS |
262 | if (!path_is_absolute(*s)) { |
263 | free(*s); | |
9eb977db | 264 | continue; |
12ed81d9 | 265 | } |
112cfb18 MM |
266 | |
267 | if (prefix) { | |
12ed81d9 ZJS |
268 | orig = *s; |
269 | t = strappend(prefix, orig); | |
112cfb18 MM |
270 | if (!t) { |
271 | enomem = true; | |
272 | continue; | |
273 | } | |
12ed81d9 | 274 | } else |
112cfb18 | 275 | t = *s; |
9eb977db KS |
276 | |
277 | errno = 0; | |
278 | u = canonicalize_file_name(t); | |
9eb977db | 279 | if (!u) { |
12ed81d9 ZJS |
280 | if (errno == ENOENT) { |
281 | if (prefix) { | |
282 | u = orig; | |
283 | orig = NULL; | |
284 | free(t); | |
285 | } else | |
286 | u = t; | |
287 | } else { | |
874310b7 | 288 | free(t); |
112cfb18 | 289 | if (errno == ENOMEM || errno == 0) |
874310b7 ZJS |
290 | enomem = true; |
291 | ||
292 | continue; | |
293 | } | |
12ed81d9 ZJS |
294 | } else if (prefix) { |
295 | char *x; | |
296 | ||
297 | free(t); | |
298 | x = path_startswith(u, prefix); | |
299 | if (x) { | |
300 | /* restore the slash if it was lost */ | |
301 | if (!startswith(x, "/")) | |
302 | *(--x) = '/'; | |
303 | ||
304 | t = strdup(x); | |
305 | free(u); | |
306 | if (!t) { | |
307 | enomem = true; | |
308 | continue; | |
309 | } | |
310 | u = t; | |
311 | } else { | |
312 | /* canonicalized path goes outside of | |
313 | * prefix, keep the original path instead */ | |
314 | u = orig; | |
315 | orig = NULL; | |
316 | } | |
91a6489d LP |
317 | } else |
318 | free(t); | |
9eb977db KS |
319 | |
320 | l[k++] = u; | |
321 | } | |
322 | ||
323 | l[k] = NULL; | |
324 | ||
325 | if (enomem) | |
326 | return NULL; | |
327 | ||
328 | return l; | |
329 | } | |
330 | ||
112cfb18 MM |
331 | char **path_strv_canonicalize_absolute_uniq(char **l, const char *prefix) { |
332 | ||
fabe5c0e LP |
333 | if (strv_isempty(l)) |
334 | return l; | |
335 | ||
112cfb18 | 336 | if (!path_strv_canonicalize_absolute(l, prefix)) |
fabe5c0e LP |
337 | return NULL; |
338 | ||
339 | return strv_uniq(l); | |
340 | } | |
341 | ||
9eb977db KS |
342 | char *path_kill_slashes(char *path) { |
343 | char *f, *t; | |
344 | bool slash = false; | |
345 | ||
346 | /* Removes redundant inner and trailing slashes. Modifies the | |
347 | * passed string in-place. | |
348 | * | |
349 | * ///foo///bar/ becomes /foo/bar | |
350 | */ | |
351 | ||
352 | for (f = path, t = path; *f; f++) { | |
353 | ||
354 | if (*f == '/') { | |
355 | slash = true; | |
356 | continue; | |
357 | } | |
358 | ||
359 | if (slash) { | |
360 | slash = false; | |
361 | *(t++) = '/'; | |
362 | } | |
363 | ||
364 | *(t++) = *f; | |
365 | } | |
366 | ||
367 | /* Special rule, if we are talking of the root directory, a | |
368 | trailing slash is good */ | |
369 | ||
370 | if (t == path && slash) | |
371 | *(t++) = '/'; | |
372 | ||
373 | *t = 0; | |
374 | return path; | |
375 | } | |
376 | ||
424a19f8 | 377 | char* path_startswith(const char *path, const char *prefix) { |
9eb977db KS |
378 | assert(path); |
379 | assert(prefix); | |
380 | ||
381 | if ((path[0] == '/') != (prefix[0] == '/')) | |
424a19f8 | 382 | return NULL; |
9eb977db KS |
383 | |
384 | for (;;) { | |
385 | size_t a, b; | |
386 | ||
387 | path += strspn(path, "/"); | |
388 | prefix += strspn(prefix, "/"); | |
389 | ||
390 | if (*prefix == 0) | |
424a19f8 | 391 | return (char*) path; |
9eb977db KS |
392 | |
393 | if (*path == 0) | |
424a19f8 | 394 | return NULL; |
9eb977db KS |
395 | |
396 | a = strcspn(path, "/"); | |
397 | b = strcspn(prefix, "/"); | |
398 | ||
399 | if (a != b) | |
424a19f8 | 400 | return NULL; |
9eb977db KS |
401 | |
402 | if (memcmp(path, prefix, a) != 0) | |
424a19f8 | 403 | return NULL; |
9eb977db KS |
404 | |
405 | path += a; | |
406 | prefix += b; | |
407 | } | |
408 | } | |
409 | ||
410 | bool path_equal(const char *a, const char *b) { | |
411 | assert(a); | |
412 | assert(b); | |
413 | ||
414 | if ((a[0] == '/') != (b[0] == '/')) | |
415 | return false; | |
416 | ||
417 | for (;;) { | |
418 | size_t j, k; | |
419 | ||
420 | a += strspn(a, "/"); | |
421 | b += strspn(b, "/"); | |
422 | ||
423 | if (*a == 0 && *b == 0) | |
424 | return true; | |
425 | ||
426 | if (*a == 0 || *b == 0) | |
427 | return false; | |
428 | ||
429 | j = strcspn(a, "/"); | |
430 | k = strcspn(b, "/"); | |
431 | ||
432 | if (j != k) | |
433 | return false; | |
434 | ||
435 | if (memcmp(a, b, j) != 0) | |
436 | return false; | |
437 | ||
438 | a += j; | |
439 | b += k; | |
440 | } | |
441 | } | |
442 | ||
443 | int path_is_mount_point(const char *t, bool allow_symlink) { | |
21749924 LP |
444 | |
445 | union file_handle_union h = { | |
446 | .handle.handle_bytes = MAX_HANDLE_SZ | |
447 | }; | |
448 | ||
cde9cb34 | 449 | int mount_id, mount_id_parent; |
21749924 | 450 | char *parent; |
1640a0b6 | 451 | struct stat a, b; |
21749924 | 452 | int r; |
9eb977db | 453 | |
cde9cb34 LP |
454 | /* We are not actually interested in the file handles, but |
455 | * name_to_handle_at() also passes us the mount ID, hence use | |
456 | * it but throw the handle away */ | |
457 | ||
458 | if (path_equal(t, "/")) | |
459 | return 1; | |
9eb977db | 460 | |
21749924 | 461 | r = name_to_handle_at(AT_FDCWD, t, &h.handle, &mount_id, allow_symlink ? AT_SYMLINK_FOLLOW : 0); |
9eb977db | 462 | if (r < 0) { |
21749924 | 463 | if (IN_SET(errno, ENOSYS, EOPNOTSUPP)) |
fa125f4e | 464 | /* This kernel or file system does not support |
1640a0b6 LP |
465 | * name_to_handle_at(), hence fallback to the |
466 | * traditional stat() logic */ | |
467 | goto fallback; | |
468 | ||
9eb977db KS |
469 | if (errno == ENOENT) |
470 | return 0; | |
471 | ||
472 | return -errno; | |
473 | } | |
474 | ||
475 | r = path_get_parent(t, &parent); | |
476 | if (r < 0) | |
477 | return r; | |
478 | ||
21749924 LP |
479 | h.handle.handle_bytes = MAX_HANDLE_SZ; |
480 | r = name_to_handle_at(AT_FDCWD, parent, &h.handle, &mount_id_parent, 0); | |
9eb977db | 481 | free(parent); |
1640a0b6 LP |
482 | if (r < 0) { |
483 | /* The parent can't do name_to_handle_at() but the | |
484 | * directory we are interested in can? If so, it must | |
485 | * be a mount point */ | |
21749924 | 486 | if (errno == EOPNOTSUPP) |
1640a0b6 LP |
487 | return 1; |
488 | ||
489 | return -errno; | |
490 | } | |
491 | ||
492 | return mount_id != mount_id_parent; | |
493 | ||
494 | fallback: | |
495 | if (allow_symlink) | |
496 | r = stat(t, &a); | |
497 | else | |
f408b8f1 | 498 | r = lstat(t, &a); |
1640a0b6 | 499 | |
8ac75493 MM |
500 | if (r < 0) { |
501 | if (errno == ENOENT) | |
502 | return 0; | |
503 | ||
9eb977db | 504 | return -errno; |
8ac75493 | 505 | } |
9eb977db | 506 | |
1640a0b6 LP |
507 | r = path_get_parent(t, &parent); |
508 | if (r < 0) | |
509 | return r; | |
cde9cb34 | 510 | |
1640a0b6 LP |
511 | r = lstat(parent, &b); |
512 | free(parent); | |
1640a0b6 LP |
513 | if (r < 0) |
514 | return -errno; | |
515 | ||
516 | return a.st_dev != b.st_dev; | |
9eb977db KS |
517 | } |
518 | ||
519 | int path_is_read_only_fs(const char *path) { | |
520 | struct statvfs st; | |
521 | ||
522 | assert(path); | |
523 | ||
524 | if (statvfs(path, &st) < 0) | |
525 | return -errno; | |
526 | ||
527 | return !!(st.f_flag & ST_RDONLY); | |
528 | } | |
66060897 LP |
529 | |
530 | int path_is_os_tree(const char *path) { | |
531 | char *p; | |
532 | int r; | |
533 | ||
534 | /* We use /etc/os-release as flag file if something is an OS */ | |
535 | ||
536 | p = strappenda(path, "/etc/os-release"); | |
537 | r = access(p, F_OK); | |
538 | ||
539 | return r < 0 ? 0 : 1; | |
540 | } | |
c9d954b2 ZJS |
541 | |
542 | int find_binary(const char *name, char **filename) { | |
543 | assert(name); | |
4087cb9e | 544 | |
c9d954b2 | 545 | if (strchr(name, '/')) { |
b972115c ZJS |
546 | if (access(name, X_OK) < 0) |
547 | return -errno; | |
548 | ||
eb66db55 MG |
549 | if (filename) { |
550 | char *p; | |
c9d954b2 | 551 | |
b972115c | 552 | p = path_make_absolute_cwd(name); |
eb66db55 MG |
553 | if (!p) |
554 | return -ENOMEM; | |
b972115c | 555 | |
eb66db55 MG |
556 | *filename = p; |
557 | } | |
c9d954b2 | 558 | |
c9d954b2 ZJS |
559 | return 0; |
560 | } else { | |
561 | const char *path; | |
562 | char *state, *w; | |
563 | size_t l; | |
564 | ||
565 | /** | |
566 | * Plain getenv, not secure_getenv, because we want | |
567 | * to actually allow the user to pick the binary. | |
568 | */ | |
569 | path = getenv("PATH"); | |
570 | if (!path) | |
571 | path = DEFAULT_PATH; | |
572 | ||
573 | FOREACH_WORD_SEPARATOR(w, l, path, ":", state) { | |
eb66db55 | 574 | _cleanup_free_ char *p = NULL; |
c9d954b2 | 575 | |
4bcc8c3c | 576 | if (asprintf(&p, "%.*s/%s", (int) l, w, name) < 0) |
c9d954b2 ZJS |
577 | return -ENOMEM; |
578 | ||
eb66db55 | 579 | if (access(p, X_OK) < 0) |
c9d954b2 | 580 | continue; |
c9d954b2 | 581 | |
eb66db55 | 582 | if (filename) { |
dbb9401d | 583 | *filename = path_kill_slashes(p); |
eb66db55 MG |
584 | p = NULL; |
585 | } | |
c9d954b2 ZJS |
586 | |
587 | return 0; | |
588 | } | |
589 | ||
590 | return -ENOENT; | |
591 | } | |
592 | } | |
8e184852 | 593 | |
2ad8416d | 594 | bool paths_check_timestamp(const char* const* paths, usec_t *timestamp, bool update) { |
8e184852 | 595 | bool changed = false; |
2ad8416d | 596 | const char* const* i; |
8e184852 | 597 | |
97f2d76d TG |
598 | assert(timestamp); |
599 | ||
8e184852 | 600 | if (paths == NULL) |
4087cb9e | 601 | return false; |
8e184852 | 602 | |
4087cb9e | 603 | STRV_FOREACH(i, paths) { |
8e184852 | 604 | struct stat stats; |
4087cb9e | 605 | usec_t u; |
8e184852 | 606 | |
4087cb9e | 607 | if (stat(*i, &stats) < 0) |
8e184852 TG |
608 | continue; |
609 | ||
4087cb9e LP |
610 | u = timespec_load(&stats.st_mtim); |
611 | ||
97f2d76d | 612 | /* first check */ |
4087cb9e | 613 | if (*timestamp >= u) |
8e184852 TG |
614 | continue; |
615 | ||
9f6445e3 | 616 | log_debug("timestamp of '%s' changed", *i); |
8e184852 TG |
617 | |
618 | /* update timestamp */ | |
4087cb9e LP |
619 | if (update) { |
620 | *timestamp = u; | |
621 | changed = true; | |
622 | } else | |
623 | return true; | |
8e184852 | 624 | } |
4087cb9e | 625 | |
8e184852 TG |
626 | return changed; |
627 | } | |
eb66db55 MG |
628 | |
629 | int fsck_exists(const char *fstype) { | |
630 | const char *checker; | |
631 | ||
632 | checker = strappenda("fsck.", fstype); | |
633 | return find_binary(checker, NULL); | |
634 | } |