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Commit | Line | Data |
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f4f15635 LP |
1 | /*** |
2 | This file is part of systemd. | |
3 | ||
4 | Copyright 2010 Lennart Poettering | |
5 | ||
6 | systemd is free software; you can redistribute it and/or modify it | |
7 | under the terms of the GNU Lesser General Public License as published by | |
8 | the Free Software Foundation; either version 2.1 of the License, or | |
9 | (at your option) any later version. | |
10 | ||
11 | systemd is distributed in the hope that it will be useful, but | |
12 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
14 | Lesser General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU Lesser General Public License | |
17 | along with systemd; If not, see <http://www.gnu.org/licenses/>. | |
18 | ***/ | |
19 | ||
11c3a366 TA |
20 | #include <dirent.h> |
21 | #include <errno.h> | |
22 | #include <stddef.h> | |
23 | #include <stdio.h> | |
24 | #include <stdlib.h> | |
25 | #include <string.h> | |
26 | #include <sys/stat.h> | |
27 | #include <time.h> | |
28 | #include <unistd.h> | |
29 | ||
b5efdb8a | 30 | #include "alloc-util.h" |
f4f15635 LP |
31 | #include "dirent-util.h" |
32 | #include "fd-util.h" | |
33 | #include "fileio.h" | |
34 | #include "fs-util.h" | |
11c3a366 TA |
35 | #include "log.h" |
36 | #include "macro.h" | |
37 | #include "missing.h" | |
93cc7779 TA |
38 | #include "mkdir.h" |
39 | #include "parse-util.h" | |
40 | #include "path-util.h" | |
34a8f081 | 41 | #include "stat-util.h" |
430fbf8e | 42 | #include "stdio-util.h" |
f4f15635 LP |
43 | #include "string-util.h" |
44 | #include "strv.h" | |
93cc7779 | 45 | #include "time-util.h" |
ee104e11 | 46 | #include "user-util.h" |
f4f15635 LP |
47 | #include "util.h" |
48 | ||
49 | int unlink_noerrno(const char *path) { | |
50 | PROTECT_ERRNO; | |
51 | int r; | |
52 | ||
53 | r = unlink(path); | |
54 | if (r < 0) | |
55 | return -errno; | |
56 | ||
57 | return 0; | |
58 | } | |
59 | ||
60 | int rmdir_parents(const char *path, const char *stop) { | |
61 | size_t l; | |
62 | int r = 0; | |
63 | ||
64 | assert(path); | |
65 | assert(stop); | |
66 | ||
67 | l = strlen(path); | |
68 | ||
69 | /* Skip trailing slashes */ | |
70 | while (l > 0 && path[l-1] == '/') | |
71 | l--; | |
72 | ||
73 | while (l > 0) { | |
74 | char *t; | |
75 | ||
76 | /* Skip last component */ | |
77 | while (l > 0 && path[l-1] != '/') | |
78 | l--; | |
79 | ||
80 | /* Skip trailing slashes */ | |
81 | while (l > 0 && path[l-1] == '/') | |
82 | l--; | |
83 | ||
84 | if (l <= 0) | |
85 | break; | |
86 | ||
87 | t = strndup(path, l); | |
88 | if (!t) | |
89 | return -ENOMEM; | |
90 | ||
91 | if (path_startswith(stop, t)) { | |
92 | free(t); | |
93 | return 0; | |
94 | } | |
95 | ||
96 | r = rmdir(t); | |
97 | free(t); | |
98 | ||
99 | if (r < 0) | |
100 | if (errno != ENOENT) | |
101 | return -errno; | |
102 | } | |
103 | ||
104 | return 0; | |
105 | } | |
106 | ||
107 | ||
108 | int rename_noreplace(int olddirfd, const char *oldpath, int newdirfd, const char *newpath) { | |
109 | struct stat buf; | |
110 | int ret; | |
111 | ||
112 | ret = renameat2(olddirfd, oldpath, newdirfd, newpath, RENAME_NOREPLACE); | |
113 | if (ret >= 0) | |
114 | return 0; | |
115 | ||
116 | /* renameat2() exists since Linux 3.15, btrfs added support for it later. | |
117 | * If it is not implemented, fallback to another method. */ | |
118 | if (!IN_SET(errno, EINVAL, ENOSYS)) | |
119 | return -errno; | |
120 | ||
121 | /* The link()/unlink() fallback does not work on directories. But | |
122 | * renameat() without RENAME_NOREPLACE gives the same semantics on | |
123 | * directories, except when newpath is an *empty* directory. This is | |
124 | * good enough. */ | |
125 | ret = fstatat(olddirfd, oldpath, &buf, AT_SYMLINK_NOFOLLOW); | |
126 | if (ret >= 0 && S_ISDIR(buf.st_mode)) { | |
127 | ret = renameat(olddirfd, oldpath, newdirfd, newpath); | |
128 | return ret >= 0 ? 0 : -errno; | |
129 | } | |
130 | ||
131 | /* If it is not a directory, use the link()/unlink() fallback. */ | |
132 | ret = linkat(olddirfd, oldpath, newdirfd, newpath, 0); | |
133 | if (ret < 0) | |
134 | return -errno; | |
135 | ||
136 | ret = unlinkat(olddirfd, oldpath, 0); | |
137 | if (ret < 0) { | |
138 | /* backup errno before the following unlinkat() alters it */ | |
139 | ret = errno; | |
140 | (void) unlinkat(newdirfd, newpath, 0); | |
141 | errno = ret; | |
142 | return -errno; | |
143 | } | |
144 | ||
145 | return 0; | |
146 | } | |
147 | ||
148 | int readlinkat_malloc(int fd, const char *p, char **ret) { | |
149 | size_t l = 100; | |
150 | int r; | |
151 | ||
152 | assert(p); | |
153 | assert(ret); | |
154 | ||
155 | for (;;) { | |
156 | char *c; | |
157 | ssize_t n; | |
158 | ||
159 | c = new(char, l); | |
160 | if (!c) | |
161 | return -ENOMEM; | |
162 | ||
163 | n = readlinkat(fd, p, c, l-1); | |
164 | if (n < 0) { | |
165 | r = -errno; | |
166 | free(c); | |
167 | return r; | |
168 | } | |
169 | ||
170 | if ((size_t) n < l-1) { | |
171 | c[n] = 0; | |
172 | *ret = c; | |
173 | return 0; | |
174 | } | |
175 | ||
176 | free(c); | |
177 | l *= 2; | |
178 | } | |
179 | } | |
180 | ||
181 | int readlink_malloc(const char *p, char **ret) { | |
182 | return readlinkat_malloc(AT_FDCWD, p, ret); | |
183 | } | |
184 | ||
185 | int readlink_value(const char *p, char **ret) { | |
186 | _cleanup_free_ char *link = NULL; | |
187 | char *value; | |
188 | int r; | |
189 | ||
190 | r = readlink_malloc(p, &link); | |
191 | if (r < 0) | |
192 | return r; | |
193 | ||
194 | value = basename(link); | |
195 | if (!value) | |
196 | return -ENOENT; | |
197 | ||
198 | value = strdup(value); | |
199 | if (!value) | |
200 | return -ENOMEM; | |
201 | ||
202 | *ret = value; | |
203 | ||
204 | return 0; | |
205 | } | |
206 | ||
207 | int readlink_and_make_absolute(const char *p, char **r) { | |
208 | _cleanup_free_ char *target = NULL; | |
209 | char *k; | |
210 | int j; | |
211 | ||
212 | assert(p); | |
213 | assert(r); | |
214 | ||
215 | j = readlink_malloc(p, &target); | |
216 | if (j < 0) | |
217 | return j; | |
218 | ||
219 | k = file_in_same_dir(p, target); | |
220 | if (!k) | |
221 | return -ENOMEM; | |
222 | ||
223 | *r = k; | |
224 | return 0; | |
225 | } | |
226 | ||
227 | int readlink_and_canonicalize(const char *p, char **r) { | |
228 | char *t, *s; | |
229 | int j; | |
230 | ||
231 | assert(p); | |
232 | assert(r); | |
233 | ||
234 | j = readlink_and_make_absolute(p, &t); | |
235 | if (j < 0) | |
236 | return j; | |
237 | ||
238 | s = canonicalize_file_name(t); | |
239 | if (s) { | |
240 | free(t); | |
241 | *r = s; | |
242 | } else | |
243 | *r = t; | |
244 | ||
245 | path_kill_slashes(*r); | |
246 | ||
247 | return 0; | |
248 | } | |
249 | ||
0ec0deaa LP |
250 | int readlink_and_make_absolute_root(const char *root, const char *path, char **ret) { |
251 | _cleanup_free_ char *target = NULL, *t = NULL; | |
252 | const char *full; | |
253 | int r; | |
254 | ||
255 | full = prefix_roota(root, path); | |
256 | r = readlink_malloc(full, &target); | |
257 | if (r < 0) | |
258 | return r; | |
259 | ||
260 | t = file_in_same_dir(path, target); | |
261 | if (!t) | |
262 | return -ENOMEM; | |
263 | ||
264 | *ret = t; | |
265 | t = NULL; | |
266 | ||
267 | return 0; | |
268 | } | |
269 | ||
f4f15635 LP |
270 | int chmod_and_chown(const char *path, mode_t mode, uid_t uid, gid_t gid) { |
271 | assert(path); | |
272 | ||
273 | /* Under the assumption that we are running privileged we | |
274 | * first change the access mode and only then hand out | |
275 | * ownership to avoid a window where access is too open. */ | |
276 | ||
277 | if (mode != MODE_INVALID) | |
278 | if (chmod(path, mode) < 0) | |
279 | return -errno; | |
280 | ||
281 | if (uid != UID_INVALID || gid != GID_INVALID) | |
282 | if (chown(path, uid, gid) < 0) | |
283 | return -errno; | |
284 | ||
285 | return 0; | |
286 | } | |
287 | ||
f4f15635 LP |
288 | int fchmod_umask(int fd, mode_t m) { |
289 | mode_t u; | |
290 | int r; | |
291 | ||
292 | u = umask(0777); | |
293 | r = fchmod(fd, m & (~u)) < 0 ? -errno : 0; | |
294 | umask(u); | |
295 | ||
296 | return r; | |
297 | } | |
298 | ||
299 | int fd_warn_permissions(const char *path, int fd) { | |
300 | struct stat st; | |
301 | ||
302 | if (fstat(fd, &st) < 0) | |
303 | return -errno; | |
304 | ||
305 | if (st.st_mode & 0111) | |
306 | log_warning("Configuration file %s is marked executable. Please remove executable permission bits. Proceeding anyway.", path); | |
307 | ||
308 | if (st.st_mode & 0002) | |
309 | log_warning("Configuration file %s is marked world-writable. Please remove world writability permission bits. Proceeding anyway.", path); | |
310 | ||
311 | if (getpid() == 1 && (st.st_mode & 0044) != 0044) | |
312 | log_warning("Configuration file %s is marked world-inaccessible. This has no effect as configuration data is accessible via APIs without restrictions. Proceeding anyway.", path); | |
313 | ||
314 | return 0; | |
315 | } | |
316 | ||
317 | int touch_file(const char *path, bool parents, usec_t stamp, uid_t uid, gid_t gid, mode_t mode) { | |
318 | _cleanup_close_ int fd; | |
319 | int r; | |
320 | ||
321 | assert(path); | |
322 | ||
323 | if (parents) | |
324 | mkdir_parents(path, 0755); | |
325 | ||
06eeacb6 MM |
326 | fd = open(path, O_WRONLY|O_CREAT|O_CLOEXEC|O_NOCTTY, |
327 | (mode == 0 || mode == MODE_INVALID) ? 0644 : mode); | |
f4f15635 LP |
328 | if (fd < 0) |
329 | return -errno; | |
330 | ||
ee735086 | 331 | if (mode != MODE_INVALID) { |
f4f15635 LP |
332 | r = fchmod(fd, mode); |
333 | if (r < 0) | |
334 | return -errno; | |
335 | } | |
336 | ||
337 | if (uid != UID_INVALID || gid != GID_INVALID) { | |
338 | r = fchown(fd, uid, gid); | |
339 | if (r < 0) | |
340 | return -errno; | |
341 | } | |
342 | ||
343 | if (stamp != USEC_INFINITY) { | |
344 | struct timespec ts[2]; | |
345 | ||
346 | timespec_store(&ts[0], stamp); | |
347 | ts[1] = ts[0]; | |
348 | r = futimens(fd, ts); | |
349 | } else | |
350 | r = futimens(fd, NULL); | |
351 | if (r < 0) | |
352 | return -errno; | |
353 | ||
354 | return 0; | |
355 | } | |
356 | ||
357 | int touch(const char *path) { | |
ee735086 | 358 | return touch_file(path, false, USEC_INFINITY, UID_INVALID, GID_INVALID, MODE_INVALID); |
f4f15635 LP |
359 | } |
360 | ||
361 | int symlink_idempotent(const char *from, const char *to) { | |
362 | _cleanup_free_ char *p = NULL; | |
363 | int r; | |
364 | ||
365 | assert(from); | |
366 | assert(to); | |
367 | ||
368 | if (symlink(from, to) < 0) { | |
369 | if (errno != EEXIST) | |
370 | return -errno; | |
371 | ||
372 | r = readlink_malloc(to, &p); | |
373 | if (r < 0) | |
374 | return r; | |
375 | ||
376 | if (!streq(p, from)) | |
377 | return -EINVAL; | |
378 | } | |
379 | ||
380 | return 0; | |
381 | } | |
382 | ||
383 | int symlink_atomic(const char *from, const char *to) { | |
384 | _cleanup_free_ char *t = NULL; | |
385 | int r; | |
386 | ||
387 | assert(from); | |
388 | assert(to); | |
389 | ||
390 | r = tempfn_random(to, NULL, &t); | |
391 | if (r < 0) | |
392 | return r; | |
393 | ||
394 | if (symlink(from, t) < 0) | |
395 | return -errno; | |
396 | ||
397 | if (rename(t, to) < 0) { | |
398 | unlink_noerrno(t); | |
399 | return -errno; | |
400 | } | |
401 | ||
402 | return 0; | |
403 | } | |
404 | ||
405 | int mknod_atomic(const char *path, mode_t mode, dev_t dev) { | |
406 | _cleanup_free_ char *t = NULL; | |
407 | int r; | |
408 | ||
409 | assert(path); | |
410 | ||
411 | r = tempfn_random(path, NULL, &t); | |
412 | if (r < 0) | |
413 | return r; | |
414 | ||
415 | if (mknod(t, mode, dev) < 0) | |
416 | return -errno; | |
417 | ||
418 | if (rename(t, path) < 0) { | |
419 | unlink_noerrno(t); | |
420 | return -errno; | |
421 | } | |
422 | ||
423 | return 0; | |
424 | } | |
425 | ||
426 | int mkfifo_atomic(const char *path, mode_t mode) { | |
427 | _cleanup_free_ char *t = NULL; | |
428 | int r; | |
429 | ||
430 | assert(path); | |
431 | ||
432 | r = tempfn_random(path, NULL, &t); | |
433 | if (r < 0) | |
434 | return r; | |
435 | ||
436 | if (mkfifo(t, mode) < 0) | |
437 | return -errno; | |
438 | ||
439 | if (rename(t, path) < 0) { | |
440 | unlink_noerrno(t); | |
441 | return -errno; | |
442 | } | |
443 | ||
444 | return 0; | |
445 | } | |
446 | ||
447 | int get_files_in_directory(const char *path, char ***list) { | |
448 | _cleanup_closedir_ DIR *d = NULL; | |
449 | size_t bufsize = 0, n = 0; | |
450 | _cleanup_strv_free_ char **l = NULL; | |
451 | ||
452 | assert(path); | |
453 | ||
454 | /* Returns all files in a directory in *list, and the number | |
455 | * of files as return value. If list is NULL returns only the | |
456 | * number. */ | |
457 | ||
458 | d = opendir(path); | |
459 | if (!d) | |
460 | return -errno; | |
461 | ||
462 | for (;;) { | |
463 | struct dirent *de; | |
464 | ||
465 | errno = 0; | |
466 | de = readdir(d); | |
b3267152 | 467 | if (!de && errno > 0) |
f4f15635 LP |
468 | return -errno; |
469 | if (!de) | |
470 | break; | |
471 | ||
472 | dirent_ensure_type(d, de); | |
473 | ||
474 | if (!dirent_is_file(de)) | |
475 | continue; | |
476 | ||
477 | if (list) { | |
478 | /* one extra slot is needed for the terminating NULL */ | |
479 | if (!GREEDY_REALLOC(l, bufsize, n + 2)) | |
480 | return -ENOMEM; | |
481 | ||
482 | l[n] = strdup(de->d_name); | |
483 | if (!l[n]) | |
484 | return -ENOMEM; | |
485 | ||
486 | l[++n] = NULL; | |
487 | } else | |
488 | n++; | |
489 | } | |
490 | ||
491 | if (list) { | |
492 | *list = l; | |
493 | l = NULL; /* avoid freeing */ | |
494 | } | |
495 | ||
496 | return n; | |
497 | } | |
430fbf8e | 498 | |
992e8f22 LP |
499 | static int getenv_tmp_dir(const char **ret_path) { |
500 | const char *n; | |
501 | int r, ret = 0; | |
34a8f081 | 502 | |
992e8f22 | 503 | assert(ret_path); |
34a8f081 | 504 | |
992e8f22 LP |
505 | /* We use the same order of environment variables python uses in tempfile.gettempdir(): |
506 | * https://docs.python.org/3/library/tempfile.html#tempfile.gettempdir */ | |
507 | FOREACH_STRING(n, "TMPDIR", "TEMP", "TMP") { | |
508 | const char *e; | |
509 | ||
510 | e = secure_getenv(n); | |
511 | if (!e) | |
512 | continue; | |
513 | if (!path_is_absolute(e)) { | |
514 | r = -ENOTDIR; | |
515 | goto next; | |
516 | } | |
517 | if (!path_is_safe(e)) { | |
518 | r = -EPERM; | |
519 | goto next; | |
520 | } | |
521 | ||
522 | r = is_dir(e, true); | |
523 | if (r < 0) | |
524 | goto next; | |
525 | if (r == 0) { | |
526 | r = -ENOTDIR; | |
527 | goto next; | |
528 | } | |
529 | ||
530 | *ret_path = e; | |
531 | return 1; | |
532 | ||
533 | next: | |
534 | /* Remember first error, to make this more debuggable */ | |
535 | if (ret >= 0) | |
536 | ret = r; | |
34a8f081 OW |
537 | } |
538 | ||
992e8f22 LP |
539 | if (ret < 0) |
540 | return ret; | |
34a8f081 | 541 | |
992e8f22 LP |
542 | *ret_path = NULL; |
543 | return ret; | |
544 | } | |
34a8f081 | 545 | |
992e8f22 LP |
546 | static int tmp_dir_internal(const char *def, const char **ret) { |
547 | const char *e; | |
548 | int r, k; | |
549 | ||
550 | assert(def); | |
551 | assert(ret); | |
552 | ||
553 | r = getenv_tmp_dir(&e); | |
554 | if (r > 0) { | |
555 | *ret = e; | |
556 | return 0; | |
557 | } | |
558 | ||
559 | k = is_dir(def, true); | |
560 | if (k == 0) | |
561 | k = -ENOTDIR; | |
562 | if (k < 0) | |
563 | return r < 0 ? r : k; | |
564 | ||
565 | *ret = def; | |
34a8f081 OW |
566 | return 0; |
567 | } | |
568 | ||
992e8f22 LP |
569 | int var_tmp_dir(const char **ret) { |
570 | ||
571 | /* Returns the location for "larger" temporary files, that is backed by physical storage if available, and thus | |
572 | * even might survive a boot: /var/tmp. If $TMPDIR (or related environment variables) are set, its value is | |
573 | * returned preferably however. Note that both this function and tmp_dir() below are affected by $TMPDIR, | |
574 | * making it a variable that overrides all temporary file storage locations. */ | |
575 | ||
576 | return tmp_dir_internal("/var/tmp", ret); | |
577 | } | |
578 | ||
579 | int tmp_dir(const char **ret) { | |
580 | ||
581 | /* Similar to var_tmp_dir() above, but returns the location for "smaller" temporary files, which is usually | |
582 | * backed by an in-memory file system: /tmp. */ | |
583 | ||
584 | return tmp_dir_internal("/tmp", ret); | |
585 | } | |
586 | ||
430fbf8e LP |
587 | int inotify_add_watch_fd(int fd, int what, uint32_t mask) { |
588 | char path[strlen("/proc/self/fd/") + DECIMAL_STR_MAX(int) + 1]; | |
589 | int r; | |
590 | ||
591 | /* This is like inotify_add_watch(), except that the file to watch is not referenced by a path, but by an fd */ | |
592 | xsprintf(path, "/proc/self/fd/%i", what); | |
593 | ||
594 | r = inotify_add_watch(fd, path, mask); | |
595 | if (r < 0) | |
596 | return -errno; | |
597 | ||
598 | return r; | |
599 | } |