Line data Source code
1 : /* SPDX-License-Identifier: LGPL-2.1+ */
2 :
3 : #include <errno.h>
4 : #include <stddef.h>
5 : #include <stdio.h>
6 : #include <stdlib.h>
7 : #include <string.h>
8 : #include <sys/stat.h>
9 : #include <linux/falloc.h>
10 : #include <linux/magic.h>
11 : #include <time.h>
12 : #include <unistd.h>
13 :
14 : #include "alloc-util.h"
15 : #include "dirent-util.h"
16 : #include "fd-util.h"
17 : #include "fs-util.h"
18 : #include "locale-util.h"
19 : #include "log.h"
20 : #include "macro.h"
21 : #include "missing.h"
22 : #include "mkdir.h"
23 : #include "parse-util.h"
24 : #include "path-util.h"
25 : #include "process-util.h"
26 : #include "stat-util.h"
27 : #include "stdio-util.h"
28 : #include "string-util.h"
29 : #include "strv.h"
30 : #include "time-util.h"
31 : #include "tmpfile-util.h"
32 : #include "user-util.h"
33 : #include "util.h"
34 :
35 55 : int unlink_noerrno(const char *path) {
36 55 : PROTECT_ERRNO;
37 : int r;
38 :
39 55 : r = unlink(path);
40 55 : if (r < 0)
41 2 : return -errno;
42 :
43 53 : return 0;
44 : }
45 :
46 20 : int rmdir_parents(const char *path, const char *stop) {
47 : size_t l;
48 20 : int r = 0;
49 :
50 20 : assert(path);
51 20 : assert(stop);
52 :
53 20 : l = strlen(path);
54 :
55 : /* Skip trailing slashes */
56 20 : while (l > 0 && path[l-1] == '/')
57 0 : l--;
58 :
59 25 : while (l > 0) {
60 : char *t;
61 :
62 : /* Skip last component */
63 490 : while (l > 0 && path[l-1] != '/')
64 465 : l--;
65 :
66 : /* Skip trailing slashes */
67 50 : while (l > 0 && path[l-1] == '/')
68 25 : l--;
69 :
70 25 : if (l <= 0)
71 0 : break;
72 :
73 25 : t = strndup(path, l);
74 25 : if (!t)
75 0 : return -ENOMEM;
76 :
77 25 : if (path_startswith(stop, t)) {
78 10 : free(t);
79 10 : return 0;
80 : }
81 :
82 15 : r = rmdir(t);
83 15 : free(t);
84 :
85 15 : if (r < 0)
86 10 : if (errno != ENOENT)
87 10 : return -errno;
88 : }
89 :
90 0 : return 0;
91 : }
92 :
93 8 : int rename_noreplace(int olddirfd, const char *oldpath, int newdirfd, const char *newpath) {
94 : int r;
95 :
96 : /* Try the ideal approach first */
97 8 : if (renameat2(olddirfd, oldpath, newdirfd, newpath, RENAME_NOREPLACE) >= 0)
98 8 : return 0;
99 :
100 : /* renameat2() exists since Linux 3.15, btrfs and FAT added support for it later. If it is not implemented,
101 : * fall back to a different method. */
102 0 : if (!IN_SET(errno, EINVAL, ENOSYS, ENOTTY))
103 0 : return -errno;
104 :
105 : /* Let's try to use linkat()+unlinkat() as fallback. This doesn't work on directories and on some file systems
106 : * that do not support hard links (such as FAT, most prominently), but for files it's pretty close to what we
107 : * want â though not atomic (i.e. for a short period both the new and the old filename will exist). */
108 0 : if (linkat(olddirfd, oldpath, newdirfd, newpath, 0) >= 0) {
109 :
110 0 : if (unlinkat(olddirfd, oldpath, 0) < 0) {
111 0 : r = -errno; /* Backup errno before the following unlinkat() alters it */
112 0 : (void) unlinkat(newdirfd, newpath, 0);
113 0 : return r;
114 : }
115 :
116 0 : return 0;
117 : }
118 :
119 0 : if (!IN_SET(errno, EINVAL, ENOSYS, ENOTTY, EPERM)) /* FAT returns EPERM on link()âĻ */
120 0 : return -errno;
121 :
122 : /* OK, neither RENAME_NOREPLACE nor linkat()+unlinkat() worked. Let's then fallback to the racy TOCTOU
123 : * vulnerable accessat(F_OK) check followed by classic, replacing renameat(), we have nothing better. */
124 :
125 0 : if (faccessat(newdirfd, newpath, F_OK, AT_SYMLINK_NOFOLLOW) >= 0)
126 0 : return -EEXIST;
127 0 : if (errno != ENOENT)
128 0 : return -errno;
129 :
130 0 : if (renameat(olddirfd, oldpath, newdirfd, newpath) < 0)
131 0 : return -errno;
132 :
133 0 : return 0;
134 : }
135 :
136 173706 : int readlinkat_malloc(int fd, const char *p, char **ret) {
137 173706 : size_t l = FILENAME_MAX+1;
138 : int r;
139 :
140 173706 : assert(p);
141 173706 : assert(ret);
142 :
143 0 : for (;;) {
144 : char *c;
145 : ssize_t n;
146 :
147 173706 : c = new(char, l);
148 173706 : if (!c)
149 0 : return -ENOMEM;
150 :
151 173706 : n = readlinkat(fd, p, c, l-1);
152 173706 : if (n < 0) {
153 2489 : r = -errno;
154 2489 : free(c);
155 2489 : return r;
156 : }
157 :
158 171217 : if ((size_t) n < l-1) {
159 171217 : c[n] = 0;
160 171217 : *ret = c;
161 171217 : return 0;
162 : }
163 :
164 0 : free(c);
165 0 : l *= 2;
166 : }
167 : }
168 :
169 168234 : int readlink_malloc(const char *p, char **ret) {
170 168234 : return readlinkat_malloc(AT_FDCWD, p, ret);
171 : }
172 :
173 8982 : int readlink_value(const char *p, char **ret) {
174 8982 : _cleanup_free_ char *link = NULL;
175 : char *value;
176 : int r;
177 :
178 8982 : r = readlink_malloc(p, &link);
179 8982 : if (r < 0)
180 2210 : return r;
181 :
182 6772 : value = basename(link);
183 6772 : if (!value)
184 0 : return -ENOENT;
185 :
186 6772 : value = strdup(value);
187 6772 : if (!value)
188 0 : return -ENOMEM;
189 :
190 6772 : *ret = value;
191 :
192 6772 : return 0;
193 : }
194 :
195 11 : int readlink_and_make_absolute(const char *p, char **r) {
196 11 : _cleanup_free_ char *target = NULL;
197 : char *k;
198 : int j;
199 :
200 11 : assert(p);
201 11 : assert(r);
202 :
203 11 : j = readlink_malloc(p, &target);
204 11 : if (j < 0)
205 0 : return j;
206 :
207 11 : k = file_in_same_dir(p, target);
208 11 : if (!k)
209 0 : return -ENOMEM;
210 :
211 11 : *r = k;
212 11 : return 0;
213 : }
214 :
215 1 : int chmod_and_chown(const char *path, mode_t mode, uid_t uid, gid_t gid) {
216 1 : _cleanup_close_ int fd = -1;
217 :
218 1 : assert(path);
219 :
220 1 : fd = open(path, O_PATH|O_CLOEXEC|O_NOFOLLOW); /* Let's acquire an O_PATH fd, as precaution to change
221 : * mode/owner on the same file */
222 1 : if (fd < 0)
223 0 : return -errno;
224 :
225 1 : return fchmod_and_chown(fd, mode, uid, gid);
226 : }
227 :
228 33139 : int fchmod_and_chown(int fd, mode_t mode, uid_t uid, gid_t gid) {
229 : bool do_chown, do_chmod;
230 : struct stat st;
231 :
232 : /* Change ownership and access mode of the specified fd. Tries to do so safely, ensuring that at no
233 : * point in time the access mode is above the old access mode under the old ownership or the new
234 : * access mode under the new ownership. Note: this call tries hard to leave the access mode
235 : * unaffected if the uid/gid is changed, i.e. it undoes implicit suid/sgid dropping the kernel does
236 : * on chown().
237 : *
238 : * This call is happy with O_PATH fds. */
239 :
240 33139 : if (fstat(fd, &st) < 0)
241 0 : return -errno;
242 :
243 33139 : do_chown =
244 33145 : (uid != UID_INVALID && st.st_uid != uid) ||
245 6 : (gid != GID_INVALID && st.st_gid != gid);
246 :
247 33139 : do_chmod =
248 66277 : !S_ISLNK(st.st_mode) && /* chmod is not defined on symlinks */
249 33138 : ((mode != MODE_INVALID && ((st.st_mode ^ mode) & 07777) != 0) ||
250 : do_chown); /* If we change ownership, make sure we reset the mode afterwards, since chown()
251 : * modifies the access mode too */
252 :
253 33139 : if (mode == MODE_INVALID)
254 33133 : mode = st.st_mode; /* If we only shall do a chown(), save original mode, since chown() might break it. */
255 6 : else if ((mode & S_IFMT) != 0 && ((mode ^ st.st_mode) & S_IFMT) != 0)
256 0 : return -EINVAL; /* insist on the right file type if it was specified */
257 :
258 33139 : if (do_chown && do_chmod) {
259 0 : mode_t minimal = st.st_mode & mode; /* the subset of the old and the new mask */
260 :
261 0 : if (((minimal ^ st.st_mode) & 07777) != 0)
262 0 : if (fchmod_opath(fd, minimal & 07777) < 0)
263 0 : return -errno;
264 : }
265 :
266 33139 : if (do_chown)
267 0 : if (fchownat(fd, "", uid, gid, AT_EMPTY_PATH) < 0)
268 0 : return -errno;
269 :
270 33139 : if (do_chmod)
271 3 : if (fchmod_opath(fd, mode & 07777) < 0)
272 0 : return -errno;
273 :
274 33139 : return do_chown || do_chmod;
275 : }
276 :
277 2 : int fchmod_umask(int fd, mode_t m) {
278 : mode_t u;
279 : int r;
280 :
281 2 : u = umask(0777);
282 2 : r = fchmod(fd, m & (~u)) < 0 ? -errno : 0;
283 2 : umask(u);
284 :
285 2 : return r;
286 : }
287 :
288 3 : int fchmod_opath(int fd, mode_t m) {
289 : char procfs_path[STRLEN("/proc/self/fd/") + DECIMAL_STR_MAX(int)];
290 :
291 : /* This function operates also on fd that might have been opened with
292 : * O_PATH. Indeed fchmodat() doesn't have the AT_EMPTY_PATH flag like
293 : * fchownat() does. */
294 :
295 3 : xsprintf(procfs_path, "/proc/self/fd/%i", fd);
296 3 : if (chmod(procfs_path, m) < 0)
297 0 : return -errno;
298 :
299 3 : return 0;
300 : }
301 :
302 849 : int fd_warn_permissions(const char *path, int fd) {
303 : struct stat st;
304 :
305 849 : if (fstat(fd, &st) < 0)
306 0 : return -errno;
307 :
308 : /* Don't complain if we are reading something that is not a file, for example /dev/null */
309 849 : if (!S_ISREG(st.st_mode))
310 0 : return 0;
311 :
312 849 : if (st.st_mode & 0111)
313 0 : log_warning("Configuration file %s is marked executable. Please remove executable permission bits. Proceeding anyway.", path);
314 :
315 849 : if (st.st_mode & 0002)
316 0 : log_warning("Configuration file %s is marked world-writable. Please remove world writability permission bits. Proceeding anyway.", path);
317 :
318 849 : if (getpid_cached() == 1 && (st.st_mode & 0044) != 0044)
319 0 : 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);
320 :
321 849 : return 0;
322 : }
323 :
324 33138 : int touch_file(const char *path, bool parents, usec_t stamp, uid_t uid, gid_t gid, mode_t mode) {
325 : char fdpath[STRLEN("/proc/self/fd/") + DECIMAL_STR_MAX(int)];
326 33138 : _cleanup_close_ int fd = -1;
327 33138 : int r, ret = 0;
328 :
329 33138 : assert(path);
330 :
331 : /* Note that touch_file() does not follow symlinks: if invoked on an existing symlink, then it is the symlink
332 : * itself which is updated, not its target
333 : *
334 : * Returns the first error we encounter, but tries to apply as much as possible. */
335 :
336 33138 : if (parents)
337 0 : (void) mkdir_parents(path, 0755);
338 :
339 : /* Initially, we try to open the node with O_PATH, so that we get a reference to the node. This is useful in
340 : * case the path refers to an existing device or socket node, as we can open it successfully in all cases, and
341 : * won't trigger any driver magic or so. */
342 33138 : fd = open(path, O_PATH|O_CLOEXEC|O_NOFOLLOW);
343 33138 : if (fd < 0) {
344 33120 : if (errno != ENOENT)
345 0 : return -errno;
346 :
347 : /* if the node doesn't exist yet, we create it, but with O_EXCL, so that we only create a regular file
348 : * here, and nothing else */
349 33120 : fd = open(path, O_WRONLY|O_CREAT|O_EXCL|O_CLOEXEC, IN_SET(mode, 0, MODE_INVALID) ? 0644 : mode);
350 33120 : if (fd < 0)
351 0 : return -errno;
352 : }
353 :
354 : /* Let's make a path from the fd, and operate on that. With this logic, we can adjust the access mode,
355 : * ownership and time of the file node in all cases, even if the fd refers to an O_PATH object â which is
356 : * something fchown(), fchmod(), futimensat() don't allow. */
357 33138 : xsprintf(fdpath, "/proc/self/fd/%i", fd);
358 :
359 33138 : ret = fchmod_and_chown(fd, mode, uid, gid);
360 :
361 33138 : if (stamp != USEC_INFINITY) {
362 : struct timespec ts[2];
363 :
364 5 : timespec_store(&ts[0], stamp);
365 5 : ts[1] = ts[0];
366 5 : r = utimensat(AT_FDCWD, fdpath, ts, 0);
367 : } else
368 33133 : r = utimensat(AT_FDCWD, fdpath, NULL, 0);
369 33138 : if (r < 0 && ret >= 0)
370 0 : return -errno;
371 :
372 33138 : return ret;
373 : }
374 :
375 33133 : int touch(const char *path) {
376 33133 : return touch_file(path, false, USEC_INFINITY, UID_INVALID, GID_INVALID, MODE_INVALID);
377 : }
378 :
379 0 : int symlink_idempotent(const char *from, const char *to, bool make_relative) {
380 0 : _cleanup_free_ char *relpath = NULL;
381 : int r;
382 :
383 0 : assert(from);
384 0 : assert(to);
385 :
386 0 : if (make_relative) {
387 0 : _cleanup_free_ char *parent = NULL;
388 :
389 0 : parent = dirname_malloc(to);
390 0 : if (!parent)
391 0 : return -ENOMEM;
392 :
393 0 : r = path_make_relative(parent, from, &relpath);
394 0 : if (r < 0)
395 0 : return r;
396 :
397 0 : from = relpath;
398 : }
399 :
400 0 : if (symlink(from, to) < 0) {
401 0 : _cleanup_free_ char *p = NULL;
402 :
403 0 : if (errno != EEXIST)
404 0 : return -errno;
405 :
406 0 : r = readlink_malloc(to, &p);
407 0 : if (r == -EINVAL) /* Not a symlink? In that case return the original error we encountered: -EEXIST */
408 0 : return -EEXIST;
409 0 : if (r < 0) /* Any other error? In that case propagate it as is */
410 0 : return r;
411 :
412 0 : if (!streq(p, from)) /* Not the symlink we want it to be? In that case, propagate the original -EEXIST */
413 0 : return -EEXIST;
414 : }
415 :
416 0 : return 0;
417 : }
418 :
419 0 : int symlink_atomic(const char *from, const char *to) {
420 0 : _cleanup_free_ char *t = NULL;
421 : int r;
422 :
423 0 : assert(from);
424 0 : assert(to);
425 :
426 0 : r = tempfn_random(to, NULL, &t);
427 0 : if (r < 0)
428 0 : return r;
429 :
430 0 : if (symlink(from, t) < 0)
431 0 : return -errno;
432 :
433 0 : if (rename(t, to) < 0) {
434 0 : unlink_noerrno(t);
435 0 : return -errno;
436 : }
437 :
438 0 : return 0;
439 : }
440 :
441 0 : int mknod_atomic(const char *path, mode_t mode, dev_t dev) {
442 0 : _cleanup_free_ char *t = NULL;
443 : int r;
444 :
445 0 : assert(path);
446 :
447 0 : r = tempfn_random(path, NULL, &t);
448 0 : if (r < 0)
449 0 : return r;
450 :
451 0 : if (mknod(t, mode, dev) < 0)
452 0 : return -errno;
453 :
454 0 : if (rename(t, path) < 0) {
455 0 : unlink_noerrno(t);
456 0 : return -errno;
457 : }
458 :
459 0 : return 0;
460 : }
461 :
462 0 : int mkfifo_atomic(const char *path, mode_t mode) {
463 0 : _cleanup_free_ char *t = NULL;
464 : int r;
465 :
466 0 : assert(path);
467 :
468 0 : r = tempfn_random(path, NULL, &t);
469 0 : if (r < 0)
470 0 : return r;
471 :
472 0 : if (mkfifo(t, mode) < 0)
473 0 : return -errno;
474 :
475 0 : if (rename(t, path) < 0) {
476 0 : unlink_noerrno(t);
477 0 : return -errno;
478 : }
479 :
480 0 : return 0;
481 : }
482 :
483 0 : int mkfifoat_atomic(int dirfd, const char *path, mode_t mode) {
484 0 : _cleanup_free_ char *t = NULL;
485 : int r;
486 :
487 0 : assert(path);
488 :
489 0 : if (path_is_absolute(path))
490 0 : return mkfifo_atomic(path, mode);
491 :
492 : /* We're only interested in the (random) filename. */
493 0 : r = tempfn_random_child("", NULL, &t);
494 0 : if (r < 0)
495 0 : return r;
496 :
497 0 : if (mkfifoat(dirfd, t, mode) < 0)
498 0 : return -errno;
499 :
500 0 : if (renameat(dirfd, t, dirfd, path) < 0) {
501 0 : unlink_noerrno(t);
502 0 : return -errno;
503 : }
504 :
505 0 : return 0;
506 : }
507 :
508 11 : int get_files_in_directory(const char *path, char ***list) {
509 11 : _cleanup_closedir_ DIR *d = NULL;
510 : struct dirent *de;
511 11 : size_t bufsize = 0, n = 0;
512 11 : _cleanup_strv_free_ char **l = NULL;
513 :
514 11 : assert(path);
515 :
516 : /* Returns all files in a directory in *list, and the number
517 : * of files as return value. If list is NULL returns only the
518 : * number. */
519 :
520 11 : d = opendir(path);
521 11 : if (!d)
522 1 : return -errno;
523 :
524 1625 : FOREACH_DIRENT_ALL(de, d, return -errno) {
525 1615 : dirent_ensure_type(d, de);
526 :
527 1615 : if (!dirent_is_file(de))
528 811 : continue;
529 :
530 804 : if (list) {
531 : /* one extra slot is needed for the terminating NULL */
532 429 : if (!GREEDY_REALLOC(l, bufsize, n + 2))
533 0 : return -ENOMEM;
534 :
535 429 : l[n] = strdup(de->d_name);
536 429 : if (!l[n])
537 0 : return -ENOMEM;
538 :
539 429 : l[++n] = NULL;
540 : } else
541 375 : n++;
542 : }
543 :
544 10 : if (list)
545 7 : *list = TAKE_PTR(l);
546 :
547 10 : return n;
548 : }
549 :
550 12 : static int getenv_tmp_dir(const char **ret_path) {
551 : const char *n;
552 12 : int r, ret = 0;
553 :
554 12 : assert(ret_path);
555 :
556 : /* We use the same order of environment variables python uses in tempfile.gettempdir():
557 : * https://docs.python.org/3/library/tempfile.html#tempfile.gettempdir */
558 45 : FOREACH_STRING(n, "TMPDIR", "TEMP", "TMP") {
559 : const char *e;
560 :
561 34 : e = secure_getenv(n);
562 34 : if (!e)
563 29 : continue;
564 5 : if (!path_is_absolute(e)) {
565 0 : r = -ENOTDIR;
566 0 : goto next;
567 : }
568 5 : if (!path_is_normalized(e)) {
569 0 : r = -EPERM;
570 0 : goto next;
571 : }
572 :
573 5 : r = is_dir(e, true);
574 5 : if (r < 0)
575 4 : goto next;
576 1 : if (r == 0) {
577 0 : r = -ENOTDIR;
578 0 : goto next;
579 : }
580 :
581 1 : *ret_path = e;
582 1 : return 1;
583 :
584 4 : next:
585 : /* Remember first error, to make this more debuggable */
586 4 : if (ret >= 0)
587 4 : ret = r;
588 : }
589 :
590 11 : if (ret < 0)
591 4 : return ret;
592 :
593 7 : *ret_path = NULL;
594 7 : return ret;
595 : }
596 :
597 12 : static int tmp_dir_internal(const char *def, const char **ret) {
598 : const char *e;
599 : int r, k;
600 :
601 12 : assert(def);
602 12 : assert(ret);
603 :
604 12 : r = getenv_tmp_dir(&e);
605 12 : if (r > 0) {
606 1 : *ret = e;
607 1 : return 0;
608 : }
609 :
610 11 : k = is_dir(def, true);
611 11 : if (k == 0)
612 0 : k = -ENOTDIR;
613 11 : if (k < 0)
614 0 : return r < 0 ? r : k;
615 :
616 11 : *ret = def;
617 11 : return 0;
618 : }
619 :
620 5 : int var_tmp_dir(const char **ret) {
621 :
622 : /* Returns the location for "larger" temporary files, that is backed by physical storage if available, and thus
623 : * even might survive a boot: /var/tmp. If $TMPDIR (or related environment variables) are set, its value is
624 : * returned preferably however. Note that both this function and tmp_dir() below are affected by $TMPDIR,
625 : * making it a variable that overrides all temporary file storage locations. */
626 :
627 5 : return tmp_dir_internal("/var/tmp", ret);
628 : }
629 :
630 7 : int tmp_dir(const char **ret) {
631 :
632 : /* Similar to var_tmp_dir() above, but returns the location for "smaller" temporary files, which is usually
633 : * backed by an in-memory file system: /tmp. */
634 :
635 7 : return tmp_dir_internal("/tmp", ret);
636 : }
637 :
638 0 : int unlink_or_warn(const char *filename) {
639 0 : if (unlink(filename) < 0 && errno != ENOENT)
640 : /* If the file doesn't exist and the fs simply was read-only (in which
641 : * case unlink() returns EROFS even if the file doesn't exist), don't
642 : * complain */
643 0 : if (errno != EROFS || access(filename, F_OK) >= 0)
644 0 : return log_error_errno(errno, "Failed to remove \"%s\": %m", filename);
645 :
646 0 : return 0;
647 : }
648 :
649 10 : int inotify_add_watch_fd(int fd, int what, uint32_t mask) {
650 : char path[STRLEN("/proc/self/fd/") + DECIMAL_STR_MAX(int) + 1];
651 : int r;
652 :
653 : /* This is like inotify_add_watch(), except that the file to watch is not referenced by a path, but by an fd */
654 10 : xsprintf(path, "/proc/self/fd/%i", what);
655 :
656 10 : r = inotify_add_watch(fd, path, mask);
657 10 : if (r < 0)
658 0 : return -errno;
659 :
660 10 : return r;
661 : }
662 :
663 54 : static bool unsafe_transition(const struct stat *a, const struct stat *b) {
664 : /* Returns true if the transition from a to b is safe, i.e. that we never transition from unprivileged to
665 : * privileged files or directories. Why bother? So that unprivileged code can't symlink to privileged files
666 : * making us believe we read something safe even though it isn't safe in the specific context we open it in. */
667 :
668 54 : if (a->st_uid == 0) /* Transitioning from privileged to unprivileged is always fine */
669 54 : return false;
670 :
671 0 : return a->st_uid != b->st_uid; /* Otherwise we need to stay within the same UID */
672 : }
673 :
674 0 : static int log_unsafe_transition(int a, int b, const char *path, unsigned flags) {
675 0 : _cleanup_free_ char *n1 = NULL, *n2 = NULL;
676 :
677 0 : if (!FLAGS_SET(flags, CHASE_WARN))
678 0 : return -ENOLINK;
679 :
680 0 : (void) fd_get_path(a, &n1);
681 0 : (void) fd_get_path(b, &n2);
682 :
683 0 : return log_warning_errno(SYNTHETIC_ERRNO(ENOLINK),
684 : "Detected unsafe path transition %s %s %s during canonicalization of %s.",
685 : n1, special_glyph(SPECIAL_GLYPH_ARROW), n2, path);
686 : }
687 :
688 0 : static int log_autofs_mount_point(int fd, const char *path, unsigned flags) {
689 0 : _cleanup_free_ char *n1 = NULL;
690 :
691 0 : if (!FLAGS_SET(flags, CHASE_WARN))
692 0 : return -EREMOTE;
693 :
694 0 : (void) fd_get_path(fd, &n1);
695 :
696 0 : return log_warning_errno(SYNTHETIC_ERRNO(EREMOTE),
697 : "Detected autofs mount point %s during canonicalization of %s.",
698 : n1, path);
699 : }
700 :
701 20289 : int chase_symlinks(const char *path, const char *original_root, unsigned flags, char **ret) {
702 20289 : _cleanup_free_ char *buffer = NULL, *done = NULL, *root = NULL;
703 20289 : _cleanup_close_ int fd = -1;
704 20289 : unsigned max_follow = CHASE_SYMLINKS_MAX; /* how many symlinks to follow before giving up and returning ELOOP */
705 : struct stat previous_stat;
706 20289 : bool exists = true;
707 : char *todo;
708 : int r;
709 :
710 20289 : assert(path);
711 :
712 : /* Either the file may be missing, or we return an fd to the final object, but both make no sense */
713 20289 : if (FLAGS_SET(flags, CHASE_NONEXISTENT | CHASE_OPEN))
714 0 : return -EINVAL;
715 :
716 20289 : if (FLAGS_SET(flags, CHASE_STEP | CHASE_OPEN))
717 0 : return -EINVAL;
718 :
719 20289 : if (isempty(path))
720 0 : return -EINVAL;
721 :
722 : /* This is a lot like canonicalize_file_name(), but takes an additional "root" parameter, that allows following
723 : * symlinks relative to a root directory, instead of the root of the host.
724 : *
725 : * Note that "root" primarily matters if we encounter an absolute symlink. It is also used when following
726 : * relative symlinks to ensure they cannot be used to "escape" the root directory. The path parameter passed is
727 : * assumed to be already prefixed by it, except if the CHASE_PREFIX_ROOT flag is set, in which case it is first
728 : * prefixed accordingly.
729 : *
730 : * Algorithmically this operates on two path buffers: "done" are the components of the path we already
731 : * processed and resolved symlinks, "." and ".." of. "todo" are the components of the path we still need to
732 : * process. On each iteration, we move one component from "todo" to "done", processing it's special meaning
733 : * each time. The "todo" path always starts with at least one slash, the "done" path always ends in no
734 : * slash. We always keep an O_PATH fd to the component we are currently processing, thus keeping lookup races
735 : * to a minimum.
736 : *
737 : * Suggested usage: whenever you want to canonicalize a path, use this function. Pass the absolute path you got
738 : * as-is: fully qualified and relative to your host's root. Optionally, specify the root parameter to tell this
739 : * function what to do when encountering a symlink with an absolute path as directory: prefix it by the
740 : * specified path.
741 : *
742 : * There are three ways to invoke this function:
743 : *
744 : * 1. Without CHASE_STEP or CHASE_OPEN: in this case the path is resolved and the normalized path is returned
745 : * in `ret`. The return value is < 0 on error. If CHASE_NONEXISTENT is also set, 0 is returned if the file
746 : * doesn't exist, > 0 otherwise. If CHASE_NONEXISTENT is not set, >= 0 is returned if the destination was
747 : * found, -ENOENT if it wasn't.
748 : *
749 : * 2. With CHASE_OPEN: in this case the destination is opened after chasing it as O_PATH and this file
750 : * descriptor is returned as return value. This is useful to open files relative to some root
751 : * directory. Note that the returned O_PATH file descriptors must be converted into a regular one (using
752 : * fd_reopen() or such) before it can be used for reading/writing. CHASE_OPEN may not be combined with
753 : * CHASE_NONEXISTENT.
754 : *
755 : * 3. With CHASE_STEP: in this case only a single step of the normalization is executed, i.e. only the first
756 : * symlink or ".." component of the path is resolved, and the resulting path is returned. This is useful if
757 : * a caller wants to trace the a path through the file system verbosely. Returns < 0 on error, > 0 if the
758 : * path is fully normalized, and == 0 for each normalization step. This may be combined with
759 : * CHASE_NONEXISTENT, in which case 1 is returned when a component is not found.
760 : *
761 : * 4. With CHASE_SAFE: in this case the path must not contain unsafe transitions, i.e. transitions from
762 : * unprivileged to privileged files or directories. In such cases the return value is -ENOLINK. If
763 : * CHASE_WARN is also set, a warning describing the unsafe transition is emitted.
764 : *
765 : * 5. With CHASE_NO_AUTOFS: in this case if an autofs mount point is encountered, path normalization
766 : * is aborted and -EREMOTE is returned. If CHASE_WARN is also set, a warning showing the path of
767 : * the mount point is emitted.
768 : *
769 : */
770 :
771 : /* A root directory of "/" or "" is identical to none */
772 20289 : if (empty_or_root(original_root))
773 20212 : original_root = NULL;
774 :
775 20289 : if (!original_root && !ret && (flags & (CHASE_NONEXISTENT|CHASE_NO_AUTOFS|CHASE_SAFE|CHASE_OPEN|CHASE_STEP)) == CHASE_OPEN) {
776 : /* Shortcut the CHASE_OPEN case if the caller isn't interested in the actual path and has no root set
777 : * and doesn't care about any of the other special features we provide either. */
778 1 : r = open(path, O_PATH|O_CLOEXEC|((flags & CHASE_NOFOLLOW) ? O_NOFOLLOW : 0));
779 1 : if (r < 0)
780 0 : return -errno;
781 :
782 1 : return r;
783 : }
784 :
785 20288 : if (original_root) {
786 77 : r = path_make_absolute_cwd(original_root, &root);
787 77 : if (r < 0)
788 0 : return r;
789 :
790 77 : if (flags & CHASE_PREFIX_ROOT) {
791 :
792 : /* We don't support relative paths in combination with a root directory */
793 2 : if (!path_is_absolute(path))
794 0 : return -EINVAL;
795 :
796 2 : path = prefix_roota(root, path);
797 : }
798 : }
799 :
800 20288 : r = path_make_absolute_cwd(path, &buffer);
801 20288 : if (r < 0)
802 0 : return r;
803 :
804 20288 : fd = open("/", O_CLOEXEC|O_NOFOLLOW|O_PATH);
805 20288 : if (fd < 0)
806 0 : return -errno;
807 :
808 20288 : if (flags & CHASE_SAFE) {
809 27 : if (fstat(fd, &previous_stat) < 0)
810 0 : return -errno;
811 : }
812 :
813 20288 : todo = buffer;
814 117559 : for (;;) {
815 137847 : _cleanup_free_ char *first = NULL;
816 137847 : _cleanup_close_ int child = -1;
817 : struct stat st;
818 : size_t n, m;
819 :
820 : /* Determine length of first component in the path */
821 137847 : n = strspn(todo, "/"); /* The slashes */
822 137847 : m = n + strcspn(todo + n, "/"); /* The entire length of the component */
823 :
824 : /* Extract the first component. */
825 137847 : first = strndup(todo, m);
826 137847 : if (!first)
827 0 : return -ENOMEM;
828 :
829 137847 : todo += m;
830 :
831 : /* Empty? Then we reached the end. */
832 137847 : if (isempty(first))
833 8291 : break;
834 :
835 : /* Just a single slash? Then we reached the end. */
836 129556 : if (path_equal(first, "/")) {
837 : /* Preserve the trailing slash */
838 :
839 11 : if (flags & CHASE_TRAIL_SLASH)
840 3 : if (!strextend(&done, "/", NULL))
841 0 : return -ENOMEM;
842 :
843 11 : break;
844 : }
845 :
846 : /* Just a dot? Then let's eat this up. */
847 129545 : if (path_equal(first, "/."))
848 18 : continue;
849 :
850 : /* Two dots? Then chop off the last bit of what we already found out. */
851 129527 : if (path_equal(first, "/..")) {
852 12922 : _cleanup_free_ char *parent = NULL;
853 12922 : _cleanup_close_ int fd_parent = -1;
854 :
855 : /* If we already are at the top, then going up will not change anything. This is in-line with
856 : * how the kernel handles this. */
857 12922 : if (empty_or_root(done))
858 16 : continue;
859 :
860 12906 : parent = dirname_malloc(done);
861 12906 : if (!parent)
862 0 : return -ENOMEM;
863 :
864 : /* Don't allow this to leave the root dir. */
865 12906 : if (root &&
866 17 : path_startswith(done, root) &&
867 17 : !path_startswith(parent, root))
868 10 : continue;
869 :
870 12896 : free_and_replace(done, parent);
871 :
872 12896 : if (flags & CHASE_STEP)
873 1 : goto chased_one;
874 :
875 12895 : fd_parent = openat(fd, "..", O_CLOEXEC|O_NOFOLLOW|O_PATH);
876 12895 : if (fd_parent < 0)
877 0 : return -errno;
878 :
879 12895 : if (flags & CHASE_SAFE) {
880 0 : if (fstat(fd_parent, &st) < 0)
881 0 : return -errno;
882 :
883 0 : if (unsafe_transition(&previous_stat, &st))
884 0 : return log_unsafe_transition(fd, fd_parent, path, flags);
885 :
886 0 : previous_stat = st;
887 : }
888 :
889 12895 : safe_close(fd);
890 12895 : fd = TAKE_FD(fd_parent);
891 :
892 12895 : continue;
893 : }
894 :
895 : /* Otherwise let's see what this is. */
896 116605 : child = openat(fd, first + n, O_CLOEXEC|O_NOFOLLOW|O_PATH);
897 116605 : if (child < 0) {
898 :
899 11979 : if (errno == ENOENT &&
900 11985 : (flags & CHASE_NONEXISTENT) &&
901 10 : (isempty(todo) || path_is_normalized(todo))) {
902 :
903 : /* If CHASE_NONEXISTENT is set, and the path does not exist, then that's OK, return
904 : * what we got so far. But don't allow this if the remaining path contains "../ or "./"
905 : * or something else weird. */
906 :
907 : /* If done is "/", as first also contains slash at the head, then remove this redundant slash. */
908 6 : if (streq_ptr(done, "/"))
909 0 : *done = '\0';
910 :
911 6 : if (!strextend(&done, first, todo, NULL))
912 0 : return -ENOMEM;
913 :
914 6 : exists = false;
915 6 : break;
916 : }
917 :
918 11973 : return -errno;
919 : }
920 :
921 104626 : if (fstat(child, &st) < 0)
922 0 : return -errno;
923 104680 : if ((flags & CHASE_SAFE) &&
924 108 : (empty_or_root(root) || (size_t)(todo - buffer) > strlen(root)) &&
925 54 : unsafe_transition(&previous_stat, &st))
926 0 : return log_unsafe_transition(fd, child, path, flags);
927 :
928 104626 : previous_stat = st;
929 :
930 104680 : if ((flags & CHASE_NO_AUTOFS) &&
931 54 : fd_is_fs_type(child, AUTOFS_SUPER_MAGIC) > 0)
932 0 : return log_autofs_mount_point(child, path, flags);
933 :
934 104626 : if (S_ISLNK(st.st_mode) && !((flags & CHASE_NOFOLLOW) && isempty(todo))) {
935 : char *joined;
936 :
937 5339 : _cleanup_free_ char *destination = NULL;
938 :
939 : /* This is a symlink, in this case read the destination. But let's make sure we don't follow
940 : * symlinks without bounds. */
941 5339 : if (--max_follow <= 0)
942 1 : return -ELOOP;
943 :
944 5338 : r = readlinkat_malloc(fd, first + n, &destination);
945 5338 : if (r < 0)
946 0 : return r;
947 5338 : if (isempty(destination))
948 0 : return -EINVAL;
949 :
950 5338 : if (path_is_absolute(destination)) {
951 :
952 : /* An absolute destination. Start the loop from the beginning, but use the root
953 : * directory as base. */
954 :
955 18 : safe_close(fd);
956 18 : fd = open(root ?: "/", O_CLOEXEC|O_NOFOLLOW|O_PATH);
957 18 : if (fd < 0)
958 0 : return -errno;
959 :
960 18 : if (flags & CHASE_SAFE) {
961 0 : if (fstat(fd, &st) < 0)
962 0 : return -errno;
963 :
964 0 : if (unsafe_transition(&previous_stat, &st))
965 0 : return log_unsafe_transition(child, fd, path, flags);
966 :
967 0 : previous_stat = st;
968 : }
969 :
970 18 : free(done);
971 :
972 : /* Note that we do not revalidate the root, we take it as is. */
973 18 : if (isempty(root))
974 8 : done = NULL;
975 : else {
976 10 : done = strdup(root);
977 10 : if (!done)
978 0 : return -ENOMEM;
979 : }
980 :
981 : /* Prefix what's left to do with what we just read, and start the loop again, but
982 : * remain in the current directory. */
983 18 : joined = path_join(destination, todo);
984 : } else
985 5320 : joined = path_join("/", destination, todo);
986 5338 : if (!joined)
987 0 : return -ENOMEM;
988 :
989 5338 : free(buffer);
990 5338 : todo = buffer = joined;
991 :
992 5338 : if (flags & CHASE_STEP)
993 5 : goto chased_one;
994 :
995 5333 : continue;
996 : }
997 :
998 : /* If this is not a symlink, then let's just add the name we read to what we already verified. */
999 99287 : if (!done)
1000 20292 : done = TAKE_PTR(first);
1001 : else {
1002 : /* If done is "/", as first also contains slash at the head, then remove this redundant slash. */
1003 78995 : if (streq(done, "/"))
1004 3 : *done = '\0';
1005 :
1006 78995 : if (!strextend(&done, first, NULL))
1007 0 : return -ENOMEM;
1008 : }
1009 :
1010 : /* And iterate again, but go one directory further down. */
1011 99287 : safe_close(fd);
1012 99287 : fd = TAKE_FD(child);
1013 : }
1014 :
1015 8308 : if (!done) {
1016 : /* Special case, turn the empty string into "/", to indicate the root directory. */
1017 1 : done = strdup("/");
1018 1 : if (!done)
1019 0 : return -ENOMEM;
1020 : }
1021 :
1022 8308 : if (ret)
1023 8256 : *ret = TAKE_PTR(done);
1024 :
1025 8308 : if (flags & CHASE_OPEN) {
1026 : /* Return the O_PATH fd we currently are looking to the caller. It can translate it to a proper fd by
1027 : * opening /proc/self/fd/xyz. */
1028 :
1029 53 : assert(fd >= 0);
1030 53 : return TAKE_FD(fd);
1031 : }
1032 :
1033 8255 : if (flags & CHASE_STEP)
1034 1 : return 1;
1035 :
1036 8254 : return exists;
1037 :
1038 6 : chased_one:
1039 6 : if (ret) {
1040 : char *c;
1041 :
1042 6 : c = strjoin(strempty(done), todo);
1043 6 : if (!c)
1044 0 : return -ENOMEM;
1045 :
1046 6 : *ret = c;
1047 : }
1048 :
1049 6 : return 0;
1050 : }
1051 :
1052 30 : int chase_symlinks_and_open(
1053 : const char *path,
1054 : const char *root,
1055 : unsigned chase_flags,
1056 : int open_flags,
1057 : char **ret_path) {
1058 :
1059 30 : _cleanup_close_ int path_fd = -1;
1060 30 : _cleanup_free_ char *p = NULL;
1061 : int r;
1062 :
1063 30 : if (chase_flags & CHASE_NONEXISTENT)
1064 0 : return -EINVAL;
1065 :
1066 30 : if (empty_or_root(root) && !ret_path && (chase_flags & (CHASE_NO_AUTOFS|CHASE_SAFE)) == 0) {
1067 : /* Shortcut this call if none of the special features of this call are requested */
1068 6 : r = open(path, open_flags);
1069 6 : if (r < 0)
1070 0 : return -errno;
1071 :
1072 6 : return r;
1073 : }
1074 :
1075 24 : path_fd = chase_symlinks(path, root, chase_flags|CHASE_OPEN, ret_path ? &p : NULL);
1076 24 : if (path_fd < 0)
1077 0 : return path_fd;
1078 :
1079 24 : r = fd_reopen(path_fd, open_flags);
1080 24 : if (r < 0)
1081 0 : return r;
1082 :
1083 24 : if (ret_path)
1084 0 : *ret_path = TAKE_PTR(p);
1085 :
1086 24 : return r;
1087 : }
1088 :
1089 0 : int chase_symlinks_and_opendir(
1090 : const char *path,
1091 : const char *root,
1092 : unsigned chase_flags,
1093 : char **ret_path,
1094 : DIR **ret_dir) {
1095 :
1096 : char procfs_path[STRLEN("/proc/self/fd/") + DECIMAL_STR_MAX(int)];
1097 0 : _cleanup_close_ int path_fd = -1;
1098 0 : _cleanup_free_ char *p = NULL;
1099 : DIR *d;
1100 :
1101 0 : if (!ret_dir)
1102 0 : return -EINVAL;
1103 0 : if (chase_flags & CHASE_NONEXISTENT)
1104 0 : return -EINVAL;
1105 :
1106 0 : if (empty_or_root(root) && !ret_path && (chase_flags & (CHASE_NO_AUTOFS|CHASE_SAFE)) == 0) {
1107 : /* Shortcut this call if none of the special features of this call are requested */
1108 0 : d = opendir(path);
1109 0 : if (!d)
1110 0 : return -errno;
1111 :
1112 0 : *ret_dir = d;
1113 0 : return 0;
1114 : }
1115 :
1116 0 : path_fd = chase_symlinks(path, root, chase_flags|CHASE_OPEN, ret_path ? &p : NULL);
1117 0 : if (path_fd < 0)
1118 0 : return path_fd;
1119 :
1120 0 : xsprintf(procfs_path, "/proc/self/fd/%i", path_fd);
1121 0 : d = opendir(procfs_path);
1122 0 : if (!d)
1123 0 : return -errno;
1124 :
1125 0 : if (ret_path)
1126 0 : *ret_path = TAKE_PTR(p);
1127 :
1128 0 : *ret_dir = d;
1129 0 : return 0;
1130 : }
1131 :
1132 71 : int chase_symlinks_and_stat(
1133 : const char *path,
1134 : const char *root,
1135 : unsigned chase_flags,
1136 : char **ret_path,
1137 : struct stat *ret_stat) {
1138 :
1139 71 : _cleanup_close_ int path_fd = -1;
1140 71 : _cleanup_free_ char *p = NULL;
1141 :
1142 71 : assert(path);
1143 71 : assert(ret_stat);
1144 :
1145 71 : if (chase_flags & CHASE_NONEXISTENT)
1146 0 : return -EINVAL;
1147 :
1148 71 : if (empty_or_root(root) && !ret_path && (chase_flags & (CHASE_NO_AUTOFS|CHASE_SAFE)) == 0) {
1149 : /* Shortcut this call if none of the special features of this call are requested */
1150 71 : if (stat(path, ret_stat) < 0)
1151 47 : return -errno;
1152 :
1153 24 : return 1;
1154 : }
1155 :
1156 0 : path_fd = chase_symlinks(path, root, chase_flags|CHASE_OPEN, ret_path ? &p : NULL);
1157 0 : if (path_fd < 0)
1158 0 : return path_fd;
1159 :
1160 0 : if (fstat(path_fd, ret_stat) < 0)
1161 0 : return -errno;
1162 :
1163 0 : if (ret_path)
1164 0 : *ret_path = TAKE_PTR(p);
1165 :
1166 0 : if (chase_flags & CHASE_OPEN)
1167 0 : return TAKE_FD(path_fd);
1168 :
1169 0 : return 1;
1170 : }
1171 :
1172 6 : int access_fd(int fd, int mode) {
1173 : char p[STRLEN("/proc/self/fd/") + DECIMAL_STR_MAX(fd) + 1];
1174 : int r;
1175 :
1176 : /* Like access() but operates on an already open fd */
1177 :
1178 6 : xsprintf(p, "/proc/self/fd/%i", fd);
1179 6 : r = access(p, mode);
1180 6 : if (r < 0)
1181 2 : return -errno;
1182 :
1183 4 : return r;
1184 : }
1185 :
1186 53 : void unlink_tempfilep(char (*p)[]) {
1187 : /* If the file is created with mkstemp(), it will (almost always)
1188 : * change the suffix. Treat this as a sign that the file was
1189 : * successfully created. We ignore both the rare case where the
1190 : * original suffix is used and unlink failures. */
1191 53 : if (!endswith(*p, ".XXXXXX"))
1192 53 : (void) unlink_noerrno(*p);
1193 53 : }
1194 :
1195 3 : int unlinkat_deallocate(int fd, const char *name, int flags) {
1196 3 : _cleanup_close_ int truncate_fd = -1;
1197 : struct stat st;
1198 : off_t l, bs;
1199 :
1200 : /* Operates like unlinkat() but also deallocates the file contents if it is a regular file and there's no other
1201 : * link to it. This is useful to ensure that other processes that might have the file open for reading won't be
1202 : * able to keep the data pinned on disk forever. This call is particular useful whenever we execute clean-up
1203 : * jobs ("vacuuming"), where we want to make sure the data is really gone and the disk space released and
1204 : * returned to the free pool.
1205 : *
1206 : * Deallocation is preferably done by FALLOC_FL_PUNCH_HOLE|FALLOC_FL_KEEP_SIZE (đ) if supported, which means
1207 : * the file won't change size. That's a good thing since we shouldn't needlessly trigger SIGBUS in other
1208 : * programs that have mmap()ed the file. (The assumption here is that changing file contents to all zeroes
1209 : * underneath those programs is the better choice than simply triggering SIGBUS in them which truncation does.)
1210 : * However if hole punching is not implemented in the kernel or file system we'll fall back to normal file
1211 : * truncation (đĒ), as our goal of deallocating the data space trumps our goal of being nice to readers (đ).
1212 : *
1213 : * Note that we attempt deallocation, but failure to succeed with that is not considered fatal, as long as the
1214 : * primary job â to delete the file â is accomplished. */
1215 :
1216 3 : if ((flags & AT_REMOVEDIR) == 0) {
1217 3 : truncate_fd = openat(fd, name, O_WRONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW|O_NONBLOCK);
1218 3 : if (truncate_fd < 0) {
1219 :
1220 : /* If this failed because the file doesn't exist propagate the error right-away. Also,
1221 : * AT_REMOVEDIR wasn't set, and we tried to open the file for writing, which means EISDIR is
1222 : * returned when this is a directory but we are not supposed to delete those, hence propagate
1223 : * the error right-away too. */
1224 0 : if (IN_SET(errno, ENOENT, EISDIR))
1225 0 : return -errno;
1226 :
1227 0 : if (errno != ELOOP) /* don't complain if this is a symlink */
1228 0 : log_debug_errno(errno, "Failed to open file '%s' for deallocation, ignoring: %m", name);
1229 : }
1230 : }
1231 :
1232 3 : if (unlinkat(fd, name, flags) < 0)
1233 0 : return -errno;
1234 :
1235 3 : if (truncate_fd < 0) /* Don't have a file handle, can't do more âšī¸ */
1236 0 : return 0;
1237 :
1238 3 : if (fstat(truncate_fd, &st) < 0) {
1239 0 : log_debug_errno(errno, "Failed to stat file '%s' for deallocation, ignoring: %m", name);
1240 0 : return 0;
1241 : }
1242 :
1243 3 : if (!S_ISREG(st.st_mode) || st.st_blocks == 0 || st.st_nlink > 0)
1244 0 : return 0;
1245 :
1246 : /* If this is a regular file, it actually took up space on disk and there are no other links it's time to
1247 : * punch-hole/truncate this to release the disk space. */
1248 :
1249 3 : bs = MAX(st.st_blksize, 512);
1250 3 : l = DIV_ROUND_UP(st.st_size, bs) * bs; /* Round up to next block size */
1251 :
1252 3 : if (fallocate(truncate_fd, FALLOC_FL_PUNCH_HOLE|FALLOC_FL_KEEP_SIZE, 0, l) >= 0)
1253 3 : return 0; /* Successfully punched a hole! đ */
1254 :
1255 : /* Fall back to truncation */
1256 0 : if (ftruncate(truncate_fd, 0) < 0) {
1257 0 : log_debug_errno(errno, "Failed to truncate file to 0, ignoring: %m");
1258 0 : return 0;
1259 : }
1260 :
1261 0 : return 0;
1262 : }
1263 :
1264 29 : int fsync_directory_of_file(int fd) {
1265 29 : _cleanup_free_ char *path = NULL;
1266 29 : _cleanup_close_ int dfd = -1;
1267 : int r;
1268 :
1269 29 : r = fd_verify_regular(fd);
1270 29 : if (r < 0)
1271 0 : return r;
1272 :
1273 29 : r = fd_get_path(fd, &path);
1274 29 : if (r < 0) {
1275 0 : log_debug_errno(r, "Failed to query /proc/self/fd/%d%s: %m",
1276 : fd,
1277 : r == -EOPNOTSUPP ? ", ignoring" : "");
1278 :
1279 0 : if (r == -EOPNOTSUPP)
1280 : /* If /proc is not available, we're most likely running in some
1281 : * chroot environment, and syncing the directory is not very
1282 : * important in that case. Let's just silently do nothing. */
1283 0 : return 0;
1284 :
1285 0 : return r;
1286 : }
1287 :
1288 29 : if (!path_is_absolute(path))
1289 0 : return -EINVAL;
1290 :
1291 29 : dfd = open_parent(path, O_CLOEXEC, 0);
1292 29 : if (dfd < 0)
1293 0 : return dfd;
1294 :
1295 29 : if (fsync(dfd) < 0)
1296 0 : return -errno;
1297 :
1298 29 : return 0;
1299 : }
1300 :
1301 0 : int fsync_full(int fd) {
1302 : int r, q;
1303 :
1304 : /* Sync both the file and the directory */
1305 :
1306 0 : r = fsync(fd) < 0 ? -errno : 0;
1307 0 : q = fsync_directory_of_file(fd);
1308 :
1309 0 : return r < 0 ? r : q;
1310 : }
1311 :
1312 0 : int fsync_path_at(int at_fd, const char *path) {
1313 0 : _cleanup_close_ int opened_fd = -1;
1314 : int fd;
1315 :
1316 0 : if (isempty(path)) {
1317 0 : if (at_fd == AT_FDCWD) {
1318 0 : opened_fd = open(".", O_RDONLY|O_DIRECTORY|O_CLOEXEC);
1319 0 : if (opened_fd < 0)
1320 0 : return -errno;
1321 :
1322 0 : fd = opened_fd;
1323 : } else
1324 0 : fd = at_fd;
1325 : } else {
1326 :
1327 0 : opened_fd = openat(at_fd, path, O_RDONLY|O_CLOEXEC);
1328 0 : if (opened_fd < 0)
1329 0 : return -errno;
1330 :
1331 0 : fd = opened_fd;
1332 : }
1333 :
1334 0 : if (fsync(fd) < 0)
1335 0 : return -errno;
1336 :
1337 0 : return 0;
1338 : }
1339 :
1340 0 : int syncfs_path(int atfd, const char *path) {
1341 0 : _cleanup_close_ int fd = -1;
1342 :
1343 0 : assert(path);
1344 :
1345 0 : fd = openat(atfd, path, O_CLOEXEC|O_RDONLY|O_NONBLOCK);
1346 0 : if (fd < 0)
1347 0 : return -errno;
1348 :
1349 0 : if (syncfs(fd) < 0)
1350 0 : return -errno;
1351 :
1352 0 : return 0;
1353 : }
1354 :
1355 60 : int open_parent(const char *path, int flags, mode_t mode) {
1356 60 : _cleanup_free_ char *parent = NULL;
1357 : int fd;
1358 :
1359 60 : if (isempty(path))
1360 0 : return -EINVAL;
1361 60 : if (path_equal(path, "/")) /* requesting the parent of the root dir is fishy, let's prohibit that */
1362 0 : return -EINVAL;
1363 :
1364 60 : parent = dirname_malloc(path);
1365 60 : if (!parent)
1366 0 : return -ENOMEM;
1367 :
1368 : /* Let's insist on O_DIRECTORY since the parent of a file or directory is a directory. Except if we open an
1369 : * O_TMPFILE file, because in that case we are actually create a regular file below the parent directory. */
1370 :
1371 60 : if (FLAGS_SET(flags, O_PATH))
1372 28 : flags |= O_DIRECTORY;
1373 32 : else if (!FLAGS_SET(flags, O_TMPFILE))
1374 29 : flags |= O_DIRECTORY|O_RDONLY;
1375 :
1376 60 : fd = open(parent, flags, mode);
1377 60 : if (fd < 0)
1378 0 : return -errno;
1379 :
1380 60 : return fd;
1381 : }
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