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Commit | Line | Data |
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db9ecf05 | 1 | /* SPDX-License-Identifier: LGPL-2.1-or-later */ |
f4f15635 | 2 | |
11c3a366 TA |
3 | #include <errno.h> |
4 | #include <stddef.h> | |
11c3a366 | 5 | #include <stdlib.h> |
1c73b069 | 6 | #include <linux/falloc.h> |
655f2da0 | 7 | #include <linux/magic.h> |
11c3a366 TA |
8 | #include <unistd.h> |
9 | ||
b5efdb8a | 10 | #include "alloc-util.h" |
ed9c0851 | 11 | #include "blockdev-util.h" |
f4f15635 LP |
12 | #include "dirent-util.h" |
13 | #include "fd-util.h" | |
ed9c0851 | 14 | #include "fileio.h" |
f4f15635 | 15 | #include "fs-util.h" |
fd74c6f3 | 16 | #include "locale-util.h" |
11c3a366 TA |
17 | #include "log.h" |
18 | #include "macro.h" | |
0499585f | 19 | #include "missing_fcntl.h" |
f5947a5e YW |
20 | #include "missing_fs.h" |
21 | #include "missing_syscall.h" | |
93cc7779 TA |
22 | #include "mkdir.h" |
23 | #include "parse-util.h" | |
24 | #include "path-util.h" | |
dccca82b | 25 | #include "process-util.h" |
053e0626 | 26 | #include "random-util.h" |
34a8f081 | 27 | #include "stat-util.h" |
430fbf8e | 28 | #include "stdio-util.h" |
f4f15635 LP |
29 | #include "string-util.h" |
30 | #include "strv.h" | |
93cc7779 | 31 | #include "time-util.h" |
e4de7287 | 32 | #include "tmpfile-util.h" |
ee104e11 | 33 | #include "user-util.h" |
f4f15635 LP |
34 | #include "util.h" |
35 | ||
36 | int unlink_noerrno(const char *path) { | |
37 | PROTECT_ERRNO; | |
38 | int r; | |
39 | ||
40 | r = unlink(path); | |
41 | if (r < 0) | |
42 | return -errno; | |
43 | ||
44 | return 0; | |
45 | } | |
46 | ||
47 | int rmdir_parents(const char *path, const char *stop) { | |
48 | size_t l; | |
49 | int r = 0; | |
50 | ||
51 | assert(path); | |
52 | assert(stop); | |
53 | ||
54 | l = strlen(path); | |
55 | ||
56 | /* Skip trailing slashes */ | |
57 | while (l > 0 && path[l-1] == '/') | |
58 | l--; | |
59 | ||
60 | while (l > 0) { | |
61 | char *t; | |
62 | ||
63 | /* Skip last component */ | |
64 | while (l > 0 && path[l-1] != '/') | |
65 | l--; | |
66 | ||
67 | /* Skip trailing slashes */ | |
68 | while (l > 0 && path[l-1] == '/') | |
69 | l--; | |
70 | ||
71 | if (l <= 0) | |
72 | break; | |
73 | ||
74 | t = strndup(path, l); | |
75 | if (!t) | |
76 | return -ENOMEM; | |
77 | ||
78 | if (path_startswith(stop, t)) { | |
79 | free(t); | |
80 | return 0; | |
81 | } | |
82 | ||
83 | r = rmdir(t); | |
84 | free(t); | |
85 | ||
86 | if (r < 0) | |
87 | if (errno != ENOENT) | |
88 | return -errno; | |
89 | } | |
90 | ||
91 | return 0; | |
92 | } | |
93 | ||
f4f15635 | 94 | int rename_noreplace(int olddirfd, const char *oldpath, int newdirfd, const char *newpath) { |
2f15b625 | 95 | int r; |
f4f15635 | 96 | |
2f15b625 LP |
97 | /* Try the ideal approach first */ |
98 | if (renameat2(olddirfd, oldpath, newdirfd, newpath, RENAME_NOREPLACE) >= 0) | |
f4f15635 LP |
99 | return 0; |
100 | ||
2f15b625 LP |
101 | /* renameat2() exists since Linux 3.15, btrfs and FAT added support for it later. If it is not implemented, |
102 | * fall back to a different method. */ | |
103 | if (!IN_SET(errno, EINVAL, ENOSYS, ENOTTY)) | |
f4f15635 LP |
104 | return -errno; |
105 | ||
2f15b625 LP |
106 | /* Let's try to use linkat()+unlinkat() as fallback. This doesn't work on directories and on some file systems |
107 | * that do not support hard links (such as FAT, most prominently), but for files it's pretty close to what we | |
108 | * want — though not atomic (i.e. for a short period both the new and the old filename will exist). */ | |
109 | if (linkat(olddirfd, oldpath, newdirfd, newpath, 0) >= 0) { | |
110 | ||
111 | if (unlinkat(olddirfd, oldpath, 0) < 0) { | |
112 | r = -errno; /* Backup errno before the following unlinkat() alters it */ | |
113 | (void) unlinkat(newdirfd, newpath, 0); | |
114 | return r; | |
115 | } | |
116 | ||
117 | return 0; | |
f4f15635 LP |
118 | } |
119 | ||
2f15b625 | 120 | if (!IN_SET(errno, EINVAL, ENOSYS, ENOTTY, EPERM)) /* FAT returns EPERM on link()… */ |
f4f15635 LP |
121 | return -errno; |
122 | ||
2aed63f4 | 123 | /* OK, neither RENAME_NOREPLACE nor linkat()+unlinkat() worked. Let's then fall back to the racy TOCTOU |
2f15b625 LP |
124 | * vulnerable accessat(F_OK) check followed by classic, replacing renameat(), we have nothing better. */ |
125 | ||
126 | if (faccessat(newdirfd, newpath, F_OK, AT_SYMLINK_NOFOLLOW) >= 0) | |
127 | return -EEXIST; | |
128 | if (errno != ENOENT) | |
129 | return -errno; | |
130 | ||
131 | if (renameat(olddirfd, oldpath, newdirfd, newpath) < 0) | |
f4f15635 | 132 | return -errno; |
f4f15635 LP |
133 | |
134 | return 0; | |
135 | } | |
136 | ||
137 | int readlinkat_malloc(int fd, const char *p, char **ret) { | |
8e060ec2 | 138 | size_t l = FILENAME_MAX+1; |
f4f15635 LP |
139 | int r; |
140 | ||
141 | assert(p); | |
142 | assert(ret); | |
143 | ||
144 | for (;;) { | |
145 | char *c; | |
146 | ssize_t n; | |
147 | ||
148 | c = new(char, l); | |
149 | if (!c) | |
150 | return -ENOMEM; | |
151 | ||
152 | n = readlinkat(fd, p, c, l-1); | |
153 | if (n < 0) { | |
154 | r = -errno; | |
155 | free(c); | |
156 | return r; | |
157 | } | |
158 | ||
159 | if ((size_t) n < l-1) { | |
160 | c[n] = 0; | |
161 | *ret = c; | |
162 | return 0; | |
163 | } | |
164 | ||
165 | free(c); | |
166 | l *= 2; | |
167 | } | |
168 | } | |
169 | ||
170 | int readlink_malloc(const char *p, char **ret) { | |
171 | return readlinkat_malloc(AT_FDCWD, p, ret); | |
172 | } | |
173 | ||
174 | int readlink_value(const char *p, char **ret) { | |
175 | _cleanup_free_ char *link = NULL; | |
176 | char *value; | |
177 | int r; | |
178 | ||
179 | r = readlink_malloc(p, &link); | |
180 | if (r < 0) | |
181 | return r; | |
182 | ||
183 | value = basename(link); | |
184 | if (!value) | |
185 | return -ENOENT; | |
186 | ||
187 | value = strdup(value); | |
188 | if (!value) | |
189 | return -ENOMEM; | |
190 | ||
191 | *ret = value; | |
192 | ||
193 | return 0; | |
194 | } | |
195 | ||
196 | int readlink_and_make_absolute(const char *p, char **r) { | |
197 | _cleanup_free_ char *target = NULL; | |
198 | char *k; | |
199 | int j; | |
200 | ||
201 | assert(p); | |
202 | assert(r); | |
203 | ||
204 | j = readlink_malloc(p, &target); | |
205 | if (j < 0) | |
206 | return j; | |
207 | ||
208 | k = file_in_same_dir(p, target); | |
209 | if (!k) | |
210 | return -ENOMEM; | |
211 | ||
212 | *r = k; | |
213 | return 0; | |
214 | } | |
215 | ||
f4f15635 | 216 | int chmod_and_chown(const char *path, mode_t mode, uid_t uid, gid_t gid) { |
de321f52 | 217 | _cleanup_close_ int fd = -1; |
30ff18d8 | 218 | |
f4f15635 LP |
219 | assert(path); |
220 | ||
30ff18d8 LP |
221 | fd = open(path, O_PATH|O_CLOEXEC|O_NOFOLLOW); /* Let's acquire an O_PATH fd, as precaution to change |
222 | * mode/owner on the same file */ | |
de321f52 LP |
223 | if (fd < 0) |
224 | return -errno; | |
225 | ||
2dbb7e94 | 226 | return fchmod_and_chown(fd, mode, uid, gid); |
b8da477e YW |
227 | } |
228 | ||
229 | int fchmod_and_chown(int fd, mode_t mode, uid_t uid, gid_t gid) { | |
2dbb7e94 | 230 | bool do_chown, do_chmod; |
30ff18d8 | 231 | struct stat st; |
dee00c19 | 232 | int r; |
30ff18d8 | 233 | |
2dbb7e94 LP |
234 | /* Change ownership and access mode of the specified fd. Tries to do so safely, ensuring that at no |
235 | * point in time the access mode is above the old access mode under the old ownership or the new | |
236 | * access mode under the new ownership. Note: this call tries hard to leave the access mode | |
237 | * unaffected if the uid/gid is changed, i.e. it undoes implicit suid/sgid dropping the kernel does | |
238 | * on chown(). | |
239 | * | |
71ec74d1 | 240 | * This call is happy with O_PATH fds. */ |
b8da477e | 241 | |
71ec74d1 | 242 | if (fstat(fd, &st) < 0) |
2dbb7e94 | 243 | return -errno; |
de321f52 | 244 | |
2dbb7e94 LP |
245 | do_chown = |
246 | (uid != UID_INVALID && st.st_uid != uid) || | |
247 | (gid != GID_INVALID && st.st_gid != gid); | |
de321f52 | 248 | |
2dbb7e94 LP |
249 | do_chmod = |
250 | !S_ISLNK(st.st_mode) && /* chmod is not defined on symlinks */ | |
251 | ((mode != MODE_INVALID && ((st.st_mode ^ mode) & 07777) != 0) || | |
252 | do_chown); /* If we change ownership, make sure we reset the mode afterwards, since chown() | |
253 | * modifies the access mode too */ | |
30ff18d8 | 254 | |
2dbb7e94 LP |
255 | if (mode == MODE_INVALID) |
256 | mode = st.st_mode; /* If we only shall do a chown(), save original mode, since chown() might break it. */ | |
257 | else if ((mode & S_IFMT) != 0 && ((mode ^ st.st_mode) & S_IFMT) != 0) | |
258 | return -EINVAL; /* insist on the right file type if it was specified */ | |
de321f52 | 259 | |
2dbb7e94 LP |
260 | if (do_chown && do_chmod) { |
261 | mode_t minimal = st.st_mode & mode; /* the subset of the old and the new mask */ | |
30ff18d8 | 262 | |
dee00c19 LP |
263 | if (((minimal ^ st.st_mode) & 07777) != 0) { |
264 | r = fchmod_opath(fd, minimal & 07777); | |
265 | if (r < 0) | |
266 | return r; | |
267 | } | |
de321f52 | 268 | } |
b8da477e | 269 | |
2dbb7e94 | 270 | if (do_chown) |
71ec74d1 | 271 | if (fchownat(fd, "", uid, gid, AT_EMPTY_PATH) < 0) |
2dbb7e94 | 272 | return -errno; |
30ff18d8 | 273 | |
dee00c19 LP |
274 | if (do_chmod) { |
275 | r = fchmod_opath(fd, mode & 07777); | |
276 | if (r < 0) | |
277 | return r; | |
278 | } | |
30ff18d8 | 279 | |
2dbb7e94 | 280 | return do_chown || do_chmod; |
f4f15635 LP |
281 | } |
282 | ||
f4f15635 LP |
283 | int fchmod_umask(int fd, mode_t m) { |
284 | mode_t u; | |
285 | int r; | |
286 | ||
287 | u = umask(0777); | |
288 | r = fchmod(fd, m & (~u)) < 0 ? -errno : 0; | |
289 | umask(u); | |
290 | ||
291 | return r; | |
292 | } | |
293 | ||
4dfaa528 | 294 | int fchmod_opath(int fd, mode_t m) { |
22dd8d35 | 295 | char procfs_path[STRLEN("/proc/self/fd/") + DECIMAL_STR_MAX(int)]; |
4dfaa528 FB |
296 | |
297 | /* This function operates also on fd that might have been opened with | |
298 | * O_PATH. Indeed fchmodat() doesn't have the AT_EMPTY_PATH flag like | |
299 | * fchownat() does. */ | |
300 | ||
301 | xsprintf(procfs_path, "/proc/self/fd/%i", fd); | |
f8606626 LP |
302 | if (chmod(procfs_path, m) < 0) { |
303 | if (errno != ENOENT) | |
304 | return -errno; | |
305 | ||
306 | if (proc_mounted() == 0) | |
307 | return -ENOSYS; /* if we have no /proc/, the concept is not implementable */ | |
308 | ||
309 | return -ENOENT; | |
310 | } | |
4dfaa528 FB |
311 | |
312 | return 0; | |
313 | } | |
314 | ||
f25bff5e LP |
315 | int futimens_opath(int fd, const struct timespec ts[2]) { |
316 | char procfs_path[STRLEN("/proc/self/fd/") + DECIMAL_STR_MAX(int)]; | |
317 | ||
318 | /* Similar to fchmod_path() but for futimens() */ | |
319 | ||
320 | xsprintf(procfs_path, "/proc/self/fd/%i", fd); | |
321 | if (utimensat(AT_FDCWD, procfs_path, ts, 0) < 0) { | |
322 | if (errno != ENOENT) | |
323 | return -errno; | |
324 | ||
325 | if (proc_mounted() == 0) | |
326 | return -ENOSYS; /* if we have no /proc/, the concept is not implementable */ | |
327 | ||
328 | return -ENOENT; | |
329 | } | |
330 | ||
331 | return 0; | |
332 | } | |
333 | ||
22ed4a6d LP |
334 | int stat_warn_permissions(const char *path, const struct stat *st) { |
335 | assert(path); | |
336 | assert(st); | |
f4f15635 | 337 | |
b6cceaae | 338 | /* Don't complain if we are reading something that is not a file, for example /dev/null */ |
22ed4a6d | 339 | if (!S_ISREG(st->st_mode)) |
b6cceaae LP |
340 | return 0; |
341 | ||
22ed4a6d | 342 | if (st->st_mode & 0111) |
f4f15635 LP |
343 | log_warning("Configuration file %s is marked executable. Please remove executable permission bits. Proceeding anyway.", path); |
344 | ||
22ed4a6d | 345 | if (st->st_mode & 0002) |
f4f15635 LP |
346 | log_warning("Configuration file %s is marked world-writable. Please remove world writability permission bits. Proceeding anyway.", path); |
347 | ||
22ed4a6d | 348 | if (getpid_cached() == 1 && (st->st_mode & 0044) != 0044) |
f4f15635 LP |
349 | 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); |
350 | ||
351 | return 0; | |
352 | } | |
353 | ||
22ed4a6d LP |
354 | int fd_warn_permissions(const char *path, int fd) { |
355 | struct stat st; | |
356 | ||
357 | assert(path); | |
358 | assert(fd >= 0); | |
359 | ||
360 | if (fstat(fd, &st) < 0) | |
361 | return -errno; | |
362 | ||
363 | return stat_warn_permissions(path, &st); | |
364 | } | |
365 | ||
f4f15635 | 366 | int touch_file(const char *path, bool parents, usec_t stamp, uid_t uid, gid_t gid, mode_t mode) { |
9e3fa6e8 LP |
367 | char fdpath[STRLEN("/proc/self/fd/") + DECIMAL_STR_MAX(int)]; |
368 | _cleanup_close_ int fd = -1; | |
369 | int r, ret = 0; | |
f4f15635 LP |
370 | |
371 | assert(path); | |
372 | ||
9e3fa6e8 LP |
373 | /* Note that touch_file() does not follow symlinks: if invoked on an existing symlink, then it is the symlink |
374 | * itself which is updated, not its target | |
375 | * | |
376 | * Returns the first error we encounter, but tries to apply as much as possible. */ | |
f4f15635 | 377 | |
9e3fa6e8 LP |
378 | if (parents) |
379 | (void) mkdir_parents(path, 0755); | |
380 | ||
381 | /* Initially, we try to open the node with O_PATH, so that we get a reference to the node. This is useful in | |
382 | * case the path refers to an existing device or socket node, as we can open it successfully in all cases, and | |
383 | * won't trigger any driver magic or so. */ | |
384 | fd = open(path, O_PATH|O_CLOEXEC|O_NOFOLLOW); | |
385 | if (fd < 0) { | |
386 | if (errno != ENOENT) | |
f4f15635 | 387 | return -errno; |
f4f15635 | 388 | |
9e3fa6e8 LP |
389 | /* if the node doesn't exist yet, we create it, but with O_EXCL, so that we only create a regular file |
390 | * here, and nothing else */ | |
391 | fd = open(path, O_WRONLY|O_CREAT|O_EXCL|O_CLOEXEC, IN_SET(mode, 0, MODE_INVALID) ? 0644 : mode); | |
392 | if (fd < 0) | |
f4f15635 LP |
393 | return -errno; |
394 | } | |
395 | ||
9e3fa6e8 LP |
396 | /* Let's make a path from the fd, and operate on that. With this logic, we can adjust the access mode, |
397 | * ownership and time of the file node in all cases, even if the fd refers to an O_PATH object — which is | |
398 | * something fchown(), fchmod(), futimensat() don't allow. */ | |
399 | xsprintf(fdpath, "/proc/self/fd/%i", fd); | |
400 | ||
4b3b5bc7 | 401 | ret = fchmod_and_chown(fd, mode, uid, gid); |
9e3fa6e8 | 402 | |
f4f15635 LP |
403 | if (stamp != USEC_INFINITY) { |
404 | struct timespec ts[2]; | |
405 | ||
406 | timespec_store(&ts[0], stamp); | |
407 | ts[1] = ts[0]; | |
9e3fa6e8 | 408 | r = utimensat(AT_FDCWD, fdpath, ts, 0); |
f4f15635 | 409 | } else |
9e3fa6e8 LP |
410 | r = utimensat(AT_FDCWD, fdpath, NULL, 0); |
411 | if (r < 0 && ret >= 0) | |
f4f15635 LP |
412 | return -errno; |
413 | ||
9e3fa6e8 | 414 | return ret; |
f4f15635 LP |
415 | } |
416 | ||
417 | int touch(const char *path) { | |
ee735086 | 418 | return touch_file(path, false, USEC_INFINITY, UID_INVALID, GID_INVALID, MODE_INVALID); |
f4f15635 LP |
419 | } |
420 | ||
6c9c51e5 YW |
421 | int symlink_idempotent(const char *from, const char *to, bool make_relative) { |
422 | _cleanup_free_ char *relpath = NULL; | |
f4f15635 LP |
423 | int r; |
424 | ||
425 | assert(from); | |
426 | assert(to); | |
427 | ||
6c9c51e5 YW |
428 | if (make_relative) { |
429 | _cleanup_free_ char *parent = NULL; | |
430 | ||
431 | parent = dirname_malloc(to); | |
432 | if (!parent) | |
433 | return -ENOMEM; | |
434 | ||
435 | r = path_make_relative(parent, from, &relpath); | |
436 | if (r < 0) | |
437 | return r; | |
438 | ||
439 | from = relpath; | |
440 | } | |
441 | ||
f4f15635 | 442 | if (symlink(from, to) < 0) { |
77b79723 LP |
443 | _cleanup_free_ char *p = NULL; |
444 | ||
f4f15635 LP |
445 | if (errno != EEXIST) |
446 | return -errno; | |
447 | ||
448 | r = readlink_malloc(to, &p); | |
77b79723 LP |
449 | if (r == -EINVAL) /* Not a symlink? In that case return the original error we encountered: -EEXIST */ |
450 | return -EEXIST; | |
451 | if (r < 0) /* Any other error? In that case propagate it as is */ | |
f4f15635 LP |
452 | return r; |
453 | ||
77b79723 LP |
454 | if (!streq(p, from)) /* Not the symlink we want it to be? In that case, propagate the original -EEXIST */ |
455 | return -EEXIST; | |
f4f15635 LP |
456 | } |
457 | ||
458 | return 0; | |
459 | } | |
460 | ||
461 | int symlink_atomic(const char *from, const char *to) { | |
462 | _cleanup_free_ char *t = NULL; | |
463 | int r; | |
464 | ||
465 | assert(from); | |
466 | assert(to); | |
467 | ||
468 | r = tempfn_random(to, NULL, &t); | |
469 | if (r < 0) | |
470 | return r; | |
471 | ||
472 | if (symlink(from, t) < 0) | |
473 | return -errno; | |
474 | ||
475 | if (rename(t, to) < 0) { | |
476 | unlink_noerrno(t); | |
477 | return -errno; | |
478 | } | |
479 | ||
480 | return 0; | |
481 | } | |
482 | ||
483 | int mknod_atomic(const char *path, mode_t mode, dev_t dev) { | |
484 | _cleanup_free_ char *t = NULL; | |
485 | int r; | |
486 | ||
487 | assert(path); | |
488 | ||
489 | r = tempfn_random(path, NULL, &t); | |
490 | if (r < 0) | |
491 | return r; | |
492 | ||
493 | if (mknod(t, mode, dev) < 0) | |
494 | return -errno; | |
495 | ||
496 | if (rename(t, path) < 0) { | |
497 | unlink_noerrno(t); | |
498 | return -errno; | |
499 | } | |
500 | ||
501 | return 0; | |
502 | } | |
503 | ||
504 | int mkfifo_atomic(const char *path, mode_t mode) { | |
505 | _cleanup_free_ char *t = NULL; | |
506 | int r; | |
507 | ||
508 | assert(path); | |
509 | ||
510 | r = tempfn_random(path, NULL, &t); | |
511 | if (r < 0) | |
512 | return r; | |
513 | ||
514 | if (mkfifo(t, mode) < 0) | |
515 | return -errno; | |
516 | ||
517 | if (rename(t, path) < 0) { | |
4fe3828c FB |
518 | unlink_noerrno(t); |
519 | return -errno; | |
520 | } | |
521 | ||
522 | return 0; | |
523 | } | |
524 | ||
525 | int mkfifoat_atomic(int dirfd, const char *path, mode_t mode) { | |
526 | _cleanup_free_ char *t = NULL; | |
527 | int r; | |
528 | ||
529 | assert(path); | |
530 | ||
531 | if (path_is_absolute(path)) | |
532 | return mkfifo_atomic(path, mode); | |
533 | ||
534 | /* We're only interested in the (random) filename. */ | |
535 | r = tempfn_random_child("", NULL, &t); | |
536 | if (r < 0) | |
537 | return r; | |
538 | ||
539 | if (mkfifoat(dirfd, t, mode) < 0) | |
540 | return -errno; | |
541 | ||
542 | if (renameat(dirfd, t, dirfd, path) < 0) { | |
f4f15635 LP |
543 | unlink_noerrno(t); |
544 | return -errno; | |
545 | } | |
546 | ||
547 | return 0; | |
548 | } | |
549 | ||
550 | int get_files_in_directory(const char *path, char ***list) { | |
551 | _cleanup_closedir_ DIR *d = NULL; | |
8fb3f009 | 552 | struct dirent *de; |
f4f15635 LP |
553 | size_t bufsize = 0, n = 0; |
554 | _cleanup_strv_free_ char **l = NULL; | |
555 | ||
556 | assert(path); | |
557 | ||
558 | /* Returns all files in a directory in *list, and the number | |
559 | * of files as return value. If list is NULL returns only the | |
560 | * number. */ | |
561 | ||
562 | d = opendir(path); | |
563 | if (!d) | |
564 | return -errno; | |
565 | ||
8fb3f009 | 566 | FOREACH_DIRENT_ALL(de, d, return -errno) { |
f4f15635 LP |
567 | dirent_ensure_type(d, de); |
568 | ||
569 | if (!dirent_is_file(de)) | |
570 | continue; | |
571 | ||
572 | if (list) { | |
573 | /* one extra slot is needed for the terminating NULL */ | |
574 | if (!GREEDY_REALLOC(l, bufsize, n + 2)) | |
575 | return -ENOMEM; | |
576 | ||
577 | l[n] = strdup(de->d_name); | |
578 | if (!l[n]) | |
579 | return -ENOMEM; | |
580 | ||
581 | l[++n] = NULL; | |
582 | } else | |
583 | n++; | |
584 | } | |
585 | ||
ae2a15bc LP |
586 | if (list) |
587 | *list = TAKE_PTR(l); | |
f4f15635 LP |
588 | |
589 | return n; | |
590 | } | |
430fbf8e | 591 | |
992e8f22 LP |
592 | static int getenv_tmp_dir(const char **ret_path) { |
593 | const char *n; | |
594 | int r, ret = 0; | |
34a8f081 | 595 | |
992e8f22 | 596 | assert(ret_path); |
34a8f081 | 597 | |
992e8f22 LP |
598 | /* We use the same order of environment variables python uses in tempfile.gettempdir(): |
599 | * https://docs.python.org/3/library/tempfile.html#tempfile.gettempdir */ | |
600 | FOREACH_STRING(n, "TMPDIR", "TEMP", "TMP") { | |
601 | const char *e; | |
602 | ||
603 | e = secure_getenv(n); | |
604 | if (!e) | |
605 | continue; | |
606 | if (!path_is_absolute(e)) { | |
607 | r = -ENOTDIR; | |
608 | goto next; | |
609 | } | |
99be45a4 | 610 | if (!path_is_normalized(e)) { |
992e8f22 LP |
611 | r = -EPERM; |
612 | goto next; | |
613 | } | |
614 | ||
615 | r = is_dir(e, true); | |
616 | if (r < 0) | |
617 | goto next; | |
618 | if (r == 0) { | |
619 | r = -ENOTDIR; | |
620 | goto next; | |
621 | } | |
622 | ||
623 | *ret_path = e; | |
624 | return 1; | |
625 | ||
626 | next: | |
627 | /* Remember first error, to make this more debuggable */ | |
628 | if (ret >= 0) | |
629 | ret = r; | |
34a8f081 OW |
630 | } |
631 | ||
992e8f22 LP |
632 | if (ret < 0) |
633 | return ret; | |
34a8f081 | 634 | |
992e8f22 LP |
635 | *ret_path = NULL; |
636 | return ret; | |
637 | } | |
34a8f081 | 638 | |
992e8f22 LP |
639 | static int tmp_dir_internal(const char *def, const char **ret) { |
640 | const char *e; | |
641 | int r, k; | |
642 | ||
643 | assert(def); | |
644 | assert(ret); | |
645 | ||
646 | r = getenv_tmp_dir(&e); | |
647 | if (r > 0) { | |
648 | *ret = e; | |
649 | return 0; | |
650 | } | |
651 | ||
652 | k = is_dir(def, true); | |
653 | if (k == 0) | |
654 | k = -ENOTDIR; | |
655 | if (k < 0) | |
656 | return r < 0 ? r : k; | |
657 | ||
658 | *ret = def; | |
34a8f081 OW |
659 | return 0; |
660 | } | |
661 | ||
992e8f22 LP |
662 | int var_tmp_dir(const char **ret) { |
663 | ||
664 | /* Returns the location for "larger" temporary files, that is backed by physical storage if available, and thus | |
665 | * even might survive a boot: /var/tmp. If $TMPDIR (or related environment variables) are set, its value is | |
666 | * returned preferably however. Note that both this function and tmp_dir() below are affected by $TMPDIR, | |
667 | * making it a variable that overrides all temporary file storage locations. */ | |
668 | ||
669 | return tmp_dir_internal("/var/tmp", ret); | |
670 | } | |
671 | ||
672 | int tmp_dir(const char **ret) { | |
673 | ||
674 | /* Similar to var_tmp_dir() above, but returns the location for "smaller" temporary files, which is usually | |
675 | * backed by an in-memory file system: /tmp. */ | |
676 | ||
677 | return tmp_dir_internal("/tmp", ret); | |
678 | } | |
679 | ||
af229d7a ZJS |
680 | int unlink_or_warn(const char *filename) { |
681 | if (unlink(filename) < 0 && errno != ENOENT) | |
682 | /* If the file doesn't exist and the fs simply was read-only (in which | |
683 | * case unlink() returns EROFS even if the file doesn't exist), don't | |
684 | * complain */ | |
685 | if (errno != EROFS || access(filename, F_OK) >= 0) | |
686 | return log_error_errno(errno, "Failed to remove \"%s\": %m", filename); | |
687 | ||
688 | return 0; | |
689 | } | |
690 | ||
430fbf8e | 691 | int inotify_add_watch_fd(int fd, int what, uint32_t mask) { |
fbd0b64f | 692 | char path[STRLEN("/proc/self/fd/") + DECIMAL_STR_MAX(int) + 1]; |
f6f4f5fe | 693 | int wd; |
430fbf8e LP |
694 | |
695 | /* This is like inotify_add_watch(), except that the file to watch is not referenced by a path, but by an fd */ | |
696 | xsprintf(path, "/proc/self/fd/%i", what); | |
697 | ||
f6f4f5fe BP |
698 | wd = inotify_add_watch(fd, path, mask); |
699 | if (wd < 0) | |
430fbf8e LP |
700 | return -errno; |
701 | ||
f6f4f5fe | 702 | return wd; |
430fbf8e | 703 | } |
d944dc95 | 704 | |
27c3112d | 705 | int inotify_add_watch_and_warn(int fd, const char *pathname, uint32_t mask) { |
f6f4f5fe | 706 | int wd; |
27c3112d | 707 | |
f6f4f5fe BP |
708 | wd = inotify_add_watch(fd, pathname, mask); |
709 | if (wd < 0) { | |
27c3112d | 710 | if (errno == ENOSPC) |
fe573a79 | 711 | return log_error_errno(errno, "Failed to add a watch for %s: inotify watch limit reached", pathname); |
27c3112d | 712 | |
fe573a79 | 713 | return log_error_errno(errno, "Failed to add a watch for %s: %m", pathname); |
27c3112d FB |
714 | } |
715 | ||
f6f4f5fe | 716 | return wd; |
27c3112d FB |
717 | } |
718 | ||
b85ee2ec | 719 | static bool unsafe_transition(const struct stat *a, const struct stat *b) { |
f14f1806 LP |
720 | /* Returns true if the transition from a to b is safe, i.e. that we never transition from unprivileged to |
721 | * privileged files or directories. Why bother? So that unprivileged code can't symlink to privileged files | |
722 | * making us believe we read something safe even though it isn't safe in the specific context we open it in. */ | |
723 | ||
724 | if (a->st_uid == 0) /* Transitioning from privileged to unprivileged is always fine */ | |
b85ee2ec | 725 | return false; |
f14f1806 | 726 | |
b85ee2ec | 727 | return a->st_uid != b->st_uid; /* Otherwise we need to stay within the same UID */ |
f14f1806 LP |
728 | } |
729 | ||
fd74c6f3 FB |
730 | static int log_unsafe_transition(int a, int b, const char *path, unsigned flags) { |
731 | _cleanup_free_ char *n1 = NULL, *n2 = NULL; | |
732 | ||
733 | if (!FLAGS_SET(flags, CHASE_WARN)) | |
36c97dec | 734 | return -ENOLINK; |
fd74c6f3 FB |
735 | |
736 | (void) fd_get_path(a, &n1); | |
737 | (void) fd_get_path(b, &n2); | |
738 | ||
36c97dec | 739 | return log_warning_errno(SYNTHETIC_ERRNO(ENOLINK), |
fd74c6f3 | 740 | "Detected unsafe path transition %s %s %s during canonicalization of %s.", |
48d837cd | 741 | strna(n1), special_glyph(SPECIAL_GLYPH_ARROW), strna(n2), path); |
fd74c6f3 FB |
742 | } |
743 | ||
145b8d0f FB |
744 | static int log_autofs_mount_point(int fd, const char *path, unsigned flags) { |
745 | _cleanup_free_ char *n1 = NULL; | |
746 | ||
747 | if (!FLAGS_SET(flags, CHASE_WARN)) | |
748 | return -EREMOTE; | |
749 | ||
750 | (void) fd_get_path(fd, &n1); | |
751 | ||
752 | return log_warning_errno(SYNTHETIC_ERRNO(EREMOTE), | |
753 | "Detected autofs mount point %s during canonicalization of %s.", | |
48d837cd | 754 | strna(n1), path); |
f14f1806 LP |
755 | } |
756 | ||
a5648b80 | 757 | int chase_symlinks(const char *path, const char *original_root, unsigned flags, char **ret_path, int *ret_fd) { |
d944dc95 LP |
758 | _cleanup_free_ char *buffer = NULL, *done = NULL, *root = NULL; |
759 | _cleanup_close_ int fd = -1; | |
f10f4215 | 760 | unsigned max_follow = CHASE_SYMLINKS_MAX; /* how many symlinks to follow before giving up and returning ELOOP */ |
f14f1806 | 761 | struct stat previous_stat; |
a9fb0867 | 762 | bool exists = true; |
d944dc95 LP |
763 | char *todo; |
764 | int r; | |
765 | ||
766 | assert(path); | |
767 | ||
1ed34d75 | 768 | /* Either the file may be missing, or we return an fd to the final object, but both make no sense */ |
a5648b80 | 769 | if ((flags & CHASE_NONEXISTENT) && ret_fd) |
1ed34d75 LP |
770 | return -EINVAL; |
771 | ||
a5648b80 | 772 | if ((flags & CHASE_STEP) && ret_fd) |
49eb3659 LP |
773 | return -EINVAL; |
774 | ||
a49424af LP |
775 | if (isempty(path)) |
776 | return -EINVAL; | |
777 | ||
d944dc95 LP |
778 | /* This is a lot like canonicalize_file_name(), but takes an additional "root" parameter, that allows following |
779 | * symlinks relative to a root directory, instead of the root of the host. | |
780 | * | |
fc4b68e5 | 781 | * Note that "root" primarily matters if we encounter an absolute symlink. It is also used when following |
c4f4fce7 LP |
782 | * relative symlinks to ensure they cannot be used to "escape" the root directory. The path parameter passed is |
783 | * assumed to be already prefixed by it, except if the CHASE_PREFIX_ROOT flag is set, in which case it is first | |
784 | * prefixed accordingly. | |
d944dc95 LP |
785 | * |
786 | * Algorithmically this operates on two path buffers: "done" are the components of the path we already | |
787 | * processed and resolved symlinks, "." and ".." of. "todo" are the components of the path we still need to | |
788 | * process. On each iteration, we move one component from "todo" to "done", processing it's special meaning | |
789 | * each time. The "todo" path always starts with at least one slash, the "done" path always ends in no | |
790 | * slash. We always keep an O_PATH fd to the component we are currently processing, thus keeping lookup races | |
4293c32b | 791 | * to a minimum. |
fc4b68e5 LP |
792 | * |
793 | * Suggested usage: whenever you want to canonicalize a path, use this function. Pass the absolute path you got | |
794 | * as-is: fully qualified and relative to your host's root. Optionally, specify the root parameter to tell this | |
795 | * function what to do when encountering a symlink with an absolute path as directory: prefix it by the | |
49eb3659 LP |
796 | * specified path. |
797 | * | |
a5648b80 | 798 | * There are five ways to invoke this function: |
49eb3659 | 799 | * |
a5648b80 ZJS |
800 | * 1. Without CHASE_STEP or ret_fd: in this case the path is resolved and the normalized path is |
801 | * returned in `ret_path`. The return value is < 0 on error. If CHASE_NONEXISTENT is also set, 0 | |
802 | * is returned if the file doesn't exist, > 0 otherwise. If CHASE_NONEXISTENT is not set, >= 0 is | |
803 | * returned if the destination was found, -ENOENT if it wasn't. | |
49eb3659 | 804 | * |
a5648b80 | 805 | * 2. With ret_fd: in this case the destination is opened after chasing it as O_PATH and this file |
49eb3659 LP |
806 | * descriptor is returned as return value. This is useful to open files relative to some root |
807 | * directory. Note that the returned O_PATH file descriptors must be converted into a regular one (using | |
a5648b80 | 808 | * fd_reopen() or such) before it can be used for reading/writing. ret_fd may not be combined with |
49eb3659 LP |
809 | * CHASE_NONEXISTENT. |
810 | * | |
811 | * 3. With CHASE_STEP: in this case only a single step of the normalization is executed, i.e. only the first | |
812 | * symlink or ".." component of the path is resolved, and the resulting path is returned. This is useful if | |
d51c4fca | 813 | * a caller wants to trace the path through the file system verbosely. Returns < 0 on error, > 0 if the |
49eb3659 LP |
814 | * path is fully normalized, and == 0 for each normalization step. This may be combined with |
815 | * CHASE_NONEXISTENT, in which case 1 is returned when a component is not found. | |
816 | * | |
36c97dec FB |
817 | * 4. With CHASE_SAFE: in this case the path must not contain unsafe transitions, i.e. transitions from |
818 | * unprivileged to privileged files or directories. In such cases the return value is -ENOLINK. If | |
4293c32b | 819 | * CHASE_WARN is also set, a warning describing the unsafe transition is emitted. |
36c97dec | 820 | * |
4293c32b ZJS |
821 | * 5. With CHASE_NO_AUTOFS: in this case if an autofs mount point is encountered, path normalization |
822 | * is aborted and -EREMOTE is returned. If CHASE_WARN is also set, a warning showing the path of | |
823 | * the mount point is emitted. | |
4293c32b | 824 | */ |
d944dc95 | 825 | |
22bc57c5 | 826 | /* A root directory of "/" or "" is identical to none */ |
57ea45e1 | 827 | if (empty_or_root(original_root)) |
22bc57c5 | 828 | original_root = NULL; |
b1bfb848 | 829 | |
a5648b80 ZJS |
830 | if (!original_root && !ret_path && !(flags & (CHASE_NONEXISTENT|CHASE_NO_AUTOFS|CHASE_SAFE|CHASE_STEP)) && ret_fd) { |
831 | /* Shortcut the ret_fd case if the caller isn't interested in the actual path and has no root set | |
244d2f07 | 832 | * and doesn't care about any of the other special features we provide either. */ |
1f56e4ce | 833 | r = open(path, O_PATH|O_CLOEXEC|((flags & CHASE_NOFOLLOW) ? O_NOFOLLOW : 0)); |
244d2f07 LP |
834 | if (r < 0) |
835 | return -errno; | |
836 | ||
a5648b80 ZJS |
837 | *ret_fd = r; |
838 | return 0; | |
244d2f07 LP |
839 | } |
840 | ||
c4f4fce7 LP |
841 | if (original_root) { |
842 | r = path_make_absolute_cwd(original_root, &root); | |
d944dc95 LP |
843 | if (r < 0) |
844 | return r; | |
c4f4fce7 | 845 | |
47d7ab72 LP |
846 | /* Simplify the root directory, so that it has no duplicate slashes and nothing at the |
847 | * end. While we won't resolve the root path we still simplify it. Note that dropping the | |
848 | * trailing slash should not change behaviour, since when opening it we specify O_DIRECTORY | |
849 | * anyway. Moreover at the end of this function after processing everything we'll always turn | |
850 | * the empty string back to "/". */ | |
851 | delete_trailing_chars(root, "/"); | |
852 | path_simplify(root, true); | |
853 | ||
382a5078 | 854 | if (flags & CHASE_PREFIX_ROOT) { |
382a5078 LP |
855 | /* We don't support relative paths in combination with a root directory */ |
856 | if (!path_is_absolute(path)) | |
857 | return -EINVAL; | |
858 | ||
c4f4fce7 | 859 | path = prefix_roota(root, path); |
382a5078 | 860 | } |
d944dc95 LP |
861 | } |
862 | ||
c4f4fce7 LP |
863 | r = path_make_absolute_cwd(path, &buffer); |
864 | if (r < 0) | |
865 | return r; | |
866 | ||
c2595d3b | 867 | fd = open(root ?: "/", O_CLOEXEC|O_DIRECTORY|O_PATH); |
d944dc95 LP |
868 | if (fd < 0) |
869 | return -errno; | |
870 | ||
f14f1806 LP |
871 | if (flags & CHASE_SAFE) { |
872 | if (fstat(fd, &previous_stat) < 0) | |
873 | return -errno; | |
874 | } | |
875 | ||
c2595d3b LP |
876 | if (root) { |
877 | _cleanup_free_ char *absolute = NULL; | |
878 | const char *e; | |
879 | ||
880 | /* If we are operating on a root directory, let's take the root directory as it is. */ | |
881 | ||
882 | e = path_startswith(buffer, root); | |
883 | if (!e) | |
884 | return log_full_errno(flags & CHASE_WARN ? LOG_WARNING : LOG_DEBUG, | |
885 | SYNTHETIC_ERRNO(ECHRNG), | |
886 | "Specified path '%s' is outside of specified root directory '%s', refusing to resolve.", | |
887 | path, root); | |
888 | ||
c2595d3b LP |
889 | done = strdup(root); |
890 | if (!done) | |
891 | return -ENOMEM; | |
c2595d3b LP |
892 | |
893 | /* Make sure "todo" starts with a slash */ | |
894 | absolute = strjoin("/", e); | |
895 | if (!absolute) | |
896 | return -ENOMEM; | |
897 | ||
898 | free_and_replace(buffer, absolute); | |
899 | } | |
900 | ||
d944dc95 LP |
901 | todo = buffer; |
902 | for (;;) { | |
903 | _cleanup_free_ char *first = NULL; | |
904 | _cleanup_close_ int child = -1; | |
905 | struct stat st; | |
906 | size_t n, m; | |
907 | ||
908 | /* Determine length of first component in the path */ | |
909 | n = strspn(todo, "/"); /* The slashes */ | |
47d7ab72 LP |
910 | |
911 | if (n > 1) { | |
912 | /* If we are looking at more than a single slash then skip all but one, so that when | |
913 | * we are done with everything we have a normalized path with only single slashes | |
914 | * separating the path components. */ | |
915 | todo += n - 1; | |
916 | n = 1; | |
917 | } | |
918 | ||
d944dc95 LP |
919 | m = n + strcspn(todo + n, "/"); /* The entire length of the component */ |
920 | ||
921 | /* Extract the first component. */ | |
922 | first = strndup(todo, m); | |
923 | if (!first) | |
924 | return -ENOMEM; | |
925 | ||
926 | todo += m; | |
927 | ||
b12d25a8 ZJS |
928 | /* Empty? Then we reached the end. */ |
929 | if (isempty(first)) | |
930 | break; | |
931 | ||
d944dc95 | 932 | /* Just a single slash? Then we reached the end. */ |
b12d25a8 ZJS |
933 | if (path_equal(first, "/")) { |
934 | /* Preserve the trailing slash */ | |
62570f6f LP |
935 | |
936 | if (flags & CHASE_TRAIL_SLASH) | |
c2bc710b | 937 | if (!strextend(&done, "/")) |
62570f6f | 938 | return -ENOMEM; |
b12d25a8 | 939 | |
d944dc95 | 940 | break; |
b12d25a8 | 941 | } |
d944dc95 LP |
942 | |
943 | /* Just a dot? Then let's eat this up. */ | |
944 | if (path_equal(first, "/.")) | |
945 | continue; | |
946 | ||
947 | /* Two dots? Then chop off the last bit of what we already found out. */ | |
948 | if (path_equal(first, "/..")) { | |
949 | _cleanup_free_ char *parent = NULL; | |
2b6d2dda | 950 | _cleanup_close_ int fd_parent = -1; |
d944dc95 | 951 | |
a4eaf3cf LP |
952 | /* If we already are at the top, then going up will not change anything. This is in-line with |
953 | * how the kernel handles this. */ | |
57ea45e1 | 954 | if (empty_or_root(done)) |
a4eaf3cf | 955 | continue; |
d944dc95 LP |
956 | |
957 | parent = dirname_malloc(done); | |
958 | if (!parent) | |
959 | return -ENOMEM; | |
960 | ||
a4eaf3cf | 961 | /* Don't allow this to leave the root dir. */ |
d944dc95 LP |
962 | if (root && |
963 | path_startswith(done, root) && | |
964 | !path_startswith(parent, root)) | |
a4eaf3cf | 965 | continue; |
d944dc95 | 966 | |
3b319885 | 967 | free_and_replace(done, parent); |
d944dc95 | 968 | |
49eb3659 LP |
969 | if (flags & CHASE_STEP) |
970 | goto chased_one; | |
971 | ||
d944dc95 LP |
972 | fd_parent = openat(fd, "..", O_CLOEXEC|O_NOFOLLOW|O_PATH); |
973 | if (fd_parent < 0) | |
974 | return -errno; | |
975 | ||
f14f1806 LP |
976 | if (flags & CHASE_SAFE) { |
977 | if (fstat(fd_parent, &st) < 0) | |
978 | return -errno; | |
979 | ||
b85ee2ec | 980 | if (unsafe_transition(&previous_stat, &st)) |
fd74c6f3 | 981 | return log_unsafe_transition(fd, fd_parent, path, flags); |
f14f1806 LP |
982 | |
983 | previous_stat = st; | |
984 | } | |
985 | ||
d944dc95 | 986 | safe_close(fd); |
c10d6bdb | 987 | fd = TAKE_FD(fd_parent); |
d944dc95 LP |
988 | |
989 | continue; | |
990 | } | |
991 | ||
992 | /* Otherwise let's see what this is. */ | |
993 | child = openat(fd, first + n, O_CLOEXEC|O_NOFOLLOW|O_PATH); | |
a9fb0867 LP |
994 | if (child < 0) { |
995 | ||
996 | if (errno == ENOENT && | |
cb638b5e | 997 | (flags & CHASE_NONEXISTENT) && |
99be45a4 | 998 | (isempty(todo) || path_is_normalized(todo))) { |
a9fb0867 | 999 | |
cb638b5e | 1000 | /* If CHASE_NONEXISTENT is set, and the path does not exist, then that's OK, return |
a9fb0867 LP |
1001 | * what we got so far. But don't allow this if the remaining path contains "../ or "./" |
1002 | * or something else weird. */ | |
1003 | ||
a1904a46 YW |
1004 | /* If done is "/", as first also contains slash at the head, then remove this redundant slash. */ |
1005 | if (streq_ptr(done, "/")) | |
1006 | *done = '\0'; | |
1007 | ||
c2bc710b | 1008 | if (!strextend(&done, first, todo)) |
a9fb0867 LP |
1009 | return -ENOMEM; |
1010 | ||
1011 | exists = false; | |
1012 | break; | |
1013 | } | |
1014 | ||
d944dc95 | 1015 | return -errno; |
a9fb0867 | 1016 | } |
d944dc95 LP |
1017 | |
1018 | if (fstat(child, &st) < 0) | |
1019 | return -errno; | |
f14f1806 | 1020 | if ((flags & CHASE_SAFE) && |
b85ee2ec | 1021 | unsafe_transition(&previous_stat, &st)) |
fd74c6f3 | 1022 | return log_unsafe_transition(fd, child, path, flags); |
f14f1806 LP |
1023 | |
1024 | previous_stat = st; | |
1025 | ||
655f2da0 | 1026 | if ((flags & CHASE_NO_AUTOFS) && |
a66fee2e | 1027 | fd_is_fs_type(child, AUTOFS_SUPER_MAGIC) > 0) |
145b8d0f | 1028 | return log_autofs_mount_point(child, path, flags); |
d944dc95 | 1029 | |
1f56e4ce | 1030 | if (S_ISLNK(st.st_mode) && !((flags & CHASE_NOFOLLOW) && isempty(todo))) { |
877777d7 | 1031 | char *joined; |
d944dc95 LP |
1032 | _cleanup_free_ char *destination = NULL; |
1033 | ||
1034 | /* This is a symlink, in this case read the destination. But let's make sure we don't follow | |
1035 | * symlinks without bounds. */ | |
1036 | if (--max_follow <= 0) | |
1037 | return -ELOOP; | |
1038 | ||
1039 | r = readlinkat_malloc(fd, first + n, &destination); | |
1040 | if (r < 0) | |
1041 | return r; | |
1042 | if (isempty(destination)) | |
1043 | return -EINVAL; | |
1044 | ||
1045 | if (path_is_absolute(destination)) { | |
1046 | ||
1047 | /* An absolute destination. Start the loop from the beginning, but use the root | |
1048 | * directory as base. */ | |
1049 | ||
1050 | safe_close(fd); | |
c2595d3b | 1051 | fd = open(root ?: "/", O_CLOEXEC|O_DIRECTORY|O_PATH); |
d944dc95 LP |
1052 | if (fd < 0) |
1053 | return -errno; | |
1054 | ||
f14f1806 LP |
1055 | if (flags & CHASE_SAFE) { |
1056 | if (fstat(fd, &st) < 0) | |
1057 | return -errno; | |
1058 | ||
b85ee2ec | 1059 | if (unsafe_transition(&previous_stat, &st)) |
fd74c6f3 | 1060 | return log_unsafe_transition(child, fd, path, flags); |
f14f1806 LP |
1061 | |
1062 | previous_stat = st; | |
1063 | } | |
1064 | ||
b539437a YW |
1065 | free(done); |
1066 | ||
d944dc95 LP |
1067 | /* Note that we do not revalidate the root, we take it as is. */ |
1068 | if (isempty(root)) | |
1069 | done = NULL; | |
1070 | else { | |
1071 | done = strdup(root); | |
1072 | if (!done) | |
1073 | return -ENOMEM; | |
1074 | } | |
1075 | ||
8c4a8ea2 LP |
1076 | /* Prefix what's left to do with what we just read, and start the loop again, but |
1077 | * remain in the current directory. */ | |
2d9b74ba | 1078 | joined = path_join(destination, todo); |
8c4a8ea2 | 1079 | } else |
2d9b74ba | 1080 | joined = path_join("/", destination, todo); |
877777d7 CCW |
1081 | if (!joined) |
1082 | return -ENOMEM; | |
d944dc95 | 1083 | |
877777d7 CCW |
1084 | free(buffer); |
1085 | todo = buffer = joined; | |
d944dc95 | 1086 | |
49eb3659 LP |
1087 | if (flags & CHASE_STEP) |
1088 | goto chased_one; | |
1089 | ||
d944dc95 LP |
1090 | continue; |
1091 | } | |
1092 | ||
1093 | /* If this is not a symlink, then let's just add the name we read to what we already verified. */ | |
ae2a15bc LP |
1094 | if (!done) |
1095 | done = TAKE_PTR(first); | |
1096 | else { | |
a1904a46 YW |
1097 | /* If done is "/", as first also contains slash at the head, then remove this redundant slash. */ |
1098 | if (streq(done, "/")) | |
1099 | *done = '\0'; | |
1100 | ||
c2bc710b | 1101 | if (!strextend(&done, first)) |
d944dc95 LP |
1102 | return -ENOMEM; |
1103 | } | |
1104 | ||
1105 | /* And iterate again, but go one directory further down. */ | |
1106 | safe_close(fd); | |
c10d6bdb | 1107 | fd = TAKE_FD(child); |
d944dc95 LP |
1108 | } |
1109 | ||
1110 | if (!done) { | |
1111 | /* Special case, turn the empty string into "/", to indicate the root directory. */ | |
1112 | done = strdup("/"); | |
1113 | if (!done) | |
1114 | return -ENOMEM; | |
1115 | } | |
1116 | ||
a5648b80 ZJS |
1117 | if (ret_path) |
1118 | *ret_path = TAKE_PTR(done); | |
d944dc95 | 1119 | |
a5648b80 ZJS |
1120 | if (ret_fd) { |
1121 | /* Return the O_PATH fd we currently are looking to the caller. It can translate it to a | |
1122 | * proper fd by opening /proc/self/fd/xyz. */ | |
1ed34d75 LP |
1123 | |
1124 | assert(fd >= 0); | |
a5648b80 | 1125 | *ret_fd = TAKE_FD(fd); |
1ed34d75 LP |
1126 | } |
1127 | ||
49eb3659 LP |
1128 | if (flags & CHASE_STEP) |
1129 | return 1; | |
1130 | ||
a9fb0867 | 1131 | return exists; |
49eb3659 LP |
1132 | |
1133 | chased_one: | |
a5648b80 | 1134 | if (ret_path) { |
49eb3659 LP |
1135 | char *c; |
1136 | ||
027cc9c9 ZJS |
1137 | c = strjoin(strempty(done), todo); |
1138 | if (!c) | |
1139 | return -ENOMEM; | |
49eb3659 | 1140 | |
a5648b80 | 1141 | *ret_path = c; |
49eb3659 LP |
1142 | } |
1143 | ||
1144 | return 0; | |
d944dc95 | 1145 | } |
57a4359e | 1146 | |
21c692e9 LP |
1147 | int chase_symlinks_and_open( |
1148 | const char *path, | |
1149 | const char *root, | |
1150 | unsigned chase_flags, | |
1151 | int open_flags, | |
1152 | char **ret_path) { | |
1153 | ||
1154 | _cleanup_close_ int path_fd = -1; | |
1155 | _cleanup_free_ char *p = NULL; | |
1156 | int r; | |
1157 | ||
1158 | if (chase_flags & CHASE_NONEXISTENT) | |
1159 | return -EINVAL; | |
1160 | ||
57ea45e1 | 1161 | if (empty_or_root(root) && !ret_path && (chase_flags & (CHASE_NO_AUTOFS|CHASE_SAFE)) == 0) { |
21c692e9 LP |
1162 | /* Shortcut this call if none of the special features of this call are requested */ |
1163 | r = open(path, open_flags); | |
1164 | if (r < 0) | |
1165 | return -errno; | |
1166 | ||
1167 | return r; | |
1168 | } | |
1169 | ||
a5648b80 ZJS |
1170 | r = chase_symlinks(path, root, chase_flags, ret_path ? &p : NULL, &path_fd); |
1171 | if (r < 0) | |
1172 | return r; | |
1173 | assert(path_fd >= 0); | |
21c692e9 LP |
1174 | |
1175 | r = fd_reopen(path_fd, open_flags); | |
1176 | if (r < 0) | |
1177 | return r; | |
1178 | ||
1179 | if (ret_path) | |
1180 | *ret_path = TAKE_PTR(p); | |
1181 | ||
1182 | return r; | |
1183 | } | |
1184 | ||
1185 | int chase_symlinks_and_opendir( | |
1186 | const char *path, | |
1187 | const char *root, | |
1188 | unsigned chase_flags, | |
1189 | char **ret_path, | |
1190 | DIR **ret_dir) { | |
1191 | ||
1192 | char procfs_path[STRLEN("/proc/self/fd/") + DECIMAL_STR_MAX(int)]; | |
1193 | _cleanup_close_ int path_fd = -1; | |
1194 | _cleanup_free_ char *p = NULL; | |
1195 | DIR *d; | |
a5648b80 | 1196 | int r; |
21c692e9 LP |
1197 | |
1198 | if (!ret_dir) | |
1199 | return -EINVAL; | |
1200 | if (chase_flags & CHASE_NONEXISTENT) | |
1201 | return -EINVAL; | |
1202 | ||
57ea45e1 | 1203 | if (empty_or_root(root) && !ret_path && (chase_flags & (CHASE_NO_AUTOFS|CHASE_SAFE)) == 0) { |
21c692e9 LP |
1204 | /* Shortcut this call if none of the special features of this call are requested */ |
1205 | d = opendir(path); | |
1206 | if (!d) | |
1207 | return -errno; | |
1208 | ||
1209 | *ret_dir = d; | |
1210 | return 0; | |
1211 | } | |
1212 | ||
a5648b80 ZJS |
1213 | r = chase_symlinks(path, root, chase_flags, ret_path ? &p : NULL, &path_fd); |
1214 | if (r < 0) | |
1215 | return r; | |
1216 | assert(path_fd >= 0); | |
21c692e9 LP |
1217 | |
1218 | xsprintf(procfs_path, "/proc/self/fd/%i", path_fd); | |
1219 | d = opendir(procfs_path); | |
1220 | if (!d) | |
1221 | return -errno; | |
1222 | ||
1223 | if (ret_path) | |
1224 | *ret_path = TAKE_PTR(p); | |
1225 | ||
1226 | *ret_dir = d; | |
1227 | return 0; | |
1228 | } | |
1229 | ||
d2bcd0ba LP |
1230 | int chase_symlinks_and_stat( |
1231 | const char *path, | |
1232 | const char *root, | |
1233 | unsigned chase_flags, | |
1234 | char **ret_path, | |
a5648b80 ZJS |
1235 | struct stat *ret_stat, |
1236 | int *ret_fd) { | |
d2bcd0ba LP |
1237 | |
1238 | _cleanup_close_ int path_fd = -1; | |
1239 | _cleanup_free_ char *p = NULL; | |
a5648b80 | 1240 | int r; |
d2bcd0ba LP |
1241 | |
1242 | assert(path); | |
1243 | assert(ret_stat); | |
1244 | ||
1245 | if (chase_flags & CHASE_NONEXISTENT) | |
1246 | return -EINVAL; | |
1247 | ||
1248 | if (empty_or_root(root) && !ret_path && (chase_flags & (CHASE_NO_AUTOFS|CHASE_SAFE)) == 0) { | |
1249 | /* Shortcut this call if none of the special features of this call are requested */ | |
1250 | if (stat(path, ret_stat) < 0) | |
1251 | return -errno; | |
1252 | ||
1253 | return 1; | |
1254 | } | |
1255 | ||
a5648b80 ZJS |
1256 | r = chase_symlinks(path, root, chase_flags, ret_path ? &p : NULL, &path_fd); |
1257 | if (r < 0) | |
1258 | return r; | |
1259 | assert(path_fd >= 0); | |
d2bcd0ba LP |
1260 | |
1261 | if (fstat(path_fd, ret_stat) < 0) | |
1262 | return -errno; | |
1263 | ||
1264 | if (ret_path) | |
1265 | *ret_path = TAKE_PTR(p); | |
a5648b80 ZJS |
1266 | if (ret_fd) |
1267 | *ret_fd = TAKE_FD(path_fd); | |
d2bcd0ba LP |
1268 | |
1269 | return 1; | |
1270 | } | |
1271 | ||
57a4359e | 1272 | int access_fd(int fd, int mode) { |
fbd0b64f | 1273 | char p[STRLEN("/proc/self/fd/") + DECIMAL_STR_MAX(fd) + 1]; |
57a4359e LP |
1274 | |
1275 | /* Like access() but operates on an already open fd */ | |
1276 | ||
1277 | xsprintf(p, "/proc/self/fd/%i", fd); | |
4265a66a LP |
1278 | if (access(p, mode) < 0) { |
1279 | if (errno != ENOENT) | |
1280 | return -errno; | |
57a4359e | 1281 | |
4265a66a LP |
1282 | /* ENOENT can mean two things: that the fd does not exist or that /proc is not mounted. Let's |
1283 | * make things debuggable and distinguish the two. */ | |
1284 | ||
1285 | if (proc_mounted() == 0) | |
1286 | return -ENOSYS; /* /proc is not available or not set up properly, we're most likely in some chroot | |
1287 | * environment. */ | |
1288 | ||
1289 | return -EBADF; /* The directory exists, hence it's the fd that doesn't. */ | |
1290 | } | |
1291 | ||
1292 | return 0; | |
57a4359e | 1293 | } |
43767d9d | 1294 | |
627d2bac ZJS |
1295 | void unlink_tempfilep(char (*p)[]) { |
1296 | /* If the file is created with mkstemp(), it will (almost always) | |
1297 | * change the suffix. Treat this as a sign that the file was | |
1298 | * successfully created. We ignore both the rare case where the | |
1299 | * original suffix is used and unlink failures. */ | |
1300 | if (!endswith(*p, ".XXXXXX")) | |
69821560 | 1301 | (void) unlink_noerrno(*p); |
627d2bac ZJS |
1302 | } |
1303 | ||
053e0626 | 1304 | int unlinkat_deallocate(int fd, const char *name, UnlinkDeallocateFlags flags) { |
43767d9d LP |
1305 | _cleanup_close_ int truncate_fd = -1; |
1306 | struct stat st; | |
1307 | off_t l, bs; | |
1308 | ||
053e0626 LP |
1309 | assert((flags & ~(UNLINK_REMOVEDIR|UNLINK_ERASE)) == 0); |
1310 | ||
43767d9d LP |
1311 | /* Operates like unlinkat() but also deallocates the file contents if it is a regular file and there's no other |
1312 | * link to it. This is useful to ensure that other processes that might have the file open for reading won't be | |
1313 | * able to keep the data pinned on disk forever. This call is particular useful whenever we execute clean-up | |
1314 | * jobs ("vacuuming"), where we want to make sure the data is really gone and the disk space released and | |
1315 | * returned to the free pool. | |
1316 | * | |
1317 | * Deallocation is preferably done by FALLOC_FL_PUNCH_HOLE|FALLOC_FL_KEEP_SIZE (👊) if supported, which means | |
1318 | * the file won't change size. That's a good thing since we shouldn't needlessly trigger SIGBUS in other | |
1319 | * programs that have mmap()ed the file. (The assumption here is that changing file contents to all zeroes | |
1320 | * underneath those programs is the better choice than simply triggering SIGBUS in them which truncation does.) | |
1321 | * However if hole punching is not implemented in the kernel or file system we'll fall back to normal file | |
1322 | * truncation (🔪), as our goal of deallocating the data space trumps our goal of being nice to readers (💐). | |
1323 | * | |
1324 | * Note that we attempt deallocation, but failure to succeed with that is not considered fatal, as long as the | |
1325 | * primary job – to delete the file – is accomplished. */ | |
1326 | ||
053e0626 | 1327 | if (!FLAGS_SET(flags, UNLINK_REMOVEDIR)) { |
43767d9d LP |
1328 | truncate_fd = openat(fd, name, O_WRONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW|O_NONBLOCK); |
1329 | if (truncate_fd < 0) { | |
1330 | ||
1331 | /* If this failed because the file doesn't exist propagate the error right-away. Also, | |
1332 | * AT_REMOVEDIR wasn't set, and we tried to open the file for writing, which means EISDIR is | |
1333 | * returned when this is a directory but we are not supposed to delete those, hence propagate | |
1334 | * the error right-away too. */ | |
1335 | if (IN_SET(errno, ENOENT, EISDIR)) | |
1336 | return -errno; | |
1337 | ||
1338 | if (errno != ELOOP) /* don't complain if this is a symlink */ | |
1339 | log_debug_errno(errno, "Failed to open file '%s' for deallocation, ignoring: %m", name); | |
1340 | } | |
1341 | } | |
1342 | ||
053e0626 | 1343 | if (unlinkat(fd, name, FLAGS_SET(flags, UNLINK_REMOVEDIR) ? AT_REMOVEDIR : 0) < 0) |
43767d9d LP |
1344 | return -errno; |
1345 | ||
1346 | if (truncate_fd < 0) /* Don't have a file handle, can't do more ☹️ */ | |
1347 | return 0; | |
1348 | ||
1349 | if (fstat(truncate_fd, &st) < 0) { | |
011723a4 | 1350 | log_debug_errno(errno, "Failed to stat file '%s' for deallocation, ignoring: %m", name); |
43767d9d LP |
1351 | return 0; |
1352 | } | |
1353 | ||
053e0626 LP |
1354 | if (!S_ISREG(st.st_mode)) |
1355 | return 0; | |
1356 | ||
1357 | if (FLAGS_SET(flags, UNLINK_ERASE) && st.st_size > 0 && st.st_nlink == 0) { | |
1358 | uint64_t left = st.st_size; | |
1359 | char buffer[64 * 1024]; | |
1360 | ||
1361 | /* If erasing is requested, let's overwrite the file with random data once before deleting | |
1362 | * it. This isn't going to give you shred(1) semantics, but hopefully should be good enough | |
1363 | * for stuff backed by tmpfs at least. | |
1364 | * | |
15dd4515 | 1365 | * Note that we only erase like this if the link count of the file is zero. If it is higher it |
053e0626 LP |
1366 | * is still linked by someone else and we'll leave it to them to remove it securely |
1367 | * eventually! */ | |
1368 | ||
1369 | random_bytes(buffer, sizeof(buffer)); | |
1370 | ||
1371 | while (left > 0) { | |
1372 | ssize_t n; | |
1373 | ||
1374 | n = write(truncate_fd, buffer, MIN(sizeof(buffer), left)); | |
1375 | if (n < 0) { | |
1376 | log_debug_errno(errno, "Failed to erase data in file '%s', ignoring.", name); | |
1377 | break; | |
1378 | } | |
1379 | ||
1380 | assert(left >= (size_t) n); | |
1381 | left -= n; | |
1382 | } | |
1383 | ||
1384 | /* Let's refresh metadata */ | |
1385 | if (fstat(truncate_fd, &st) < 0) { | |
1386 | log_debug_errno(errno, "Failed to stat file '%s' for deallocation, ignoring: %m", name); | |
1387 | return 0; | |
1388 | } | |
1389 | } | |
1390 | ||
1391 | /* Don't dallocate if there's nothing to deallocate or if the file is linked elsewhere */ | |
1392 | if (st.st_blocks == 0 || st.st_nlink > 0) | |
43767d9d LP |
1393 | return 0; |
1394 | ||
1395 | /* If this is a regular file, it actually took up space on disk and there are no other links it's time to | |
1396 | * punch-hole/truncate this to release the disk space. */ | |
1397 | ||
1398 | bs = MAX(st.st_blksize, 512); | |
1399 | l = DIV_ROUND_UP(st.st_size, bs) * bs; /* Round up to next block size */ | |
1400 | ||
1401 | if (fallocate(truncate_fd, FALLOC_FL_PUNCH_HOLE|FALLOC_FL_KEEP_SIZE, 0, l) >= 0) | |
1402 | return 0; /* Successfully punched a hole! 😊 */ | |
1403 | ||
1404 | /* Fall back to truncation */ | |
1405 | if (ftruncate(truncate_fd, 0) < 0) { | |
1406 | log_debug_errno(errno, "Failed to truncate file to 0, ignoring: %m"); | |
1407 | return 0; | |
1408 | } | |
1409 | ||
1410 | return 0; | |
1411 | } | |
11b29a96 LP |
1412 | |
1413 | int fsync_directory_of_file(int fd) { | |
0c462ea4 | 1414 | _cleanup_free_ char *path = NULL; |
11b29a96 LP |
1415 | _cleanup_close_ int dfd = -1; |
1416 | int r; | |
1417 | ||
1418 | r = fd_verify_regular(fd); | |
1419 | if (r < 0) | |
1420 | return r; | |
1421 | ||
1422 | r = fd_get_path(fd, &path); | |
3ceae1bc | 1423 | if (r < 0) { |
b8b846d7 LP |
1424 | log_debug_errno(r, "Failed to query /proc/self/fd/%d%s: %m", |
1425 | fd, | |
8fe8f3aa | 1426 | r == -ENOSYS ? ", ignoring" : ""); |
3ceae1bc | 1427 | |
8fe8f3aa | 1428 | if (r == -ENOSYS) |
3ceae1bc ZJS |
1429 | /* If /proc is not available, we're most likely running in some |
1430 | * chroot environment, and syncing the directory is not very | |
1431 | * important in that case. Let's just silently do nothing. */ | |
1432 | return 0; | |
1433 | ||
11b29a96 | 1434 | return r; |
3ceae1bc | 1435 | } |
11b29a96 LP |
1436 | |
1437 | if (!path_is_absolute(path)) | |
1438 | return -EINVAL; | |
1439 | ||
0c462ea4 | 1440 | dfd = open_parent(path, O_CLOEXEC, 0); |
11b29a96 | 1441 | if (dfd < 0) |
0c462ea4 | 1442 | return dfd; |
11b29a96 LP |
1443 | |
1444 | if (fsync(dfd) < 0) | |
1445 | return -errno; | |
1446 | ||
1447 | return 0; | |
1448 | } | |
ef8becfa | 1449 | |
63d59b8d LP |
1450 | int fsync_full(int fd) { |
1451 | int r, q; | |
1452 | ||
1453 | /* Sync both the file and the directory */ | |
1454 | ||
1455 | r = fsync(fd) < 0 ? -errno : 0; | |
1456 | q = fsync_directory_of_file(fd); | |
1457 | ||
1458 | return r < 0 ? r : q; | |
1459 | } | |
1460 | ||
36695e88 LP |
1461 | int fsync_path_at(int at_fd, const char *path) { |
1462 | _cleanup_close_ int opened_fd = -1; | |
1463 | int fd; | |
1464 | ||
1465 | if (isempty(path)) { | |
1466 | if (at_fd == AT_FDCWD) { | |
1467 | opened_fd = open(".", O_RDONLY|O_DIRECTORY|O_CLOEXEC); | |
1468 | if (opened_fd < 0) | |
1469 | return -errno; | |
1470 | ||
1471 | fd = opened_fd; | |
1472 | } else | |
1473 | fd = at_fd; | |
1474 | } else { | |
1475 | ||
1476 | opened_fd = openat(at_fd, path, O_RDONLY|O_CLOEXEC); | |
1477 | if (opened_fd < 0) | |
1478 | return -errno; | |
1479 | ||
1480 | fd = opened_fd; | |
1481 | } | |
1482 | ||
1483 | if (fsync(fd) < 0) | |
1484 | return -errno; | |
1485 | ||
1486 | return 0; | |
1487 | } | |
1488 | ||
71f51416 LP |
1489 | int syncfs_path(int atfd, const char *path) { |
1490 | _cleanup_close_ int fd = -1; | |
1491 | ||
1492 | assert(path); | |
1493 | ||
1494 | fd = openat(atfd, path, O_CLOEXEC|O_RDONLY|O_NONBLOCK); | |
1495 | if (fd < 0) | |
1496 | return -errno; | |
1497 | ||
1498 | if (syncfs(fd) < 0) | |
1499 | return -errno; | |
1500 | ||
1501 | return 0; | |
1502 | } | |
1503 | ||
ef8becfa LP |
1504 | int open_parent(const char *path, int flags, mode_t mode) { |
1505 | _cleanup_free_ char *parent = NULL; | |
1506 | int fd; | |
1507 | ||
1508 | if (isempty(path)) | |
1509 | return -EINVAL; | |
1510 | if (path_equal(path, "/")) /* requesting the parent of the root dir is fishy, let's prohibit that */ | |
1511 | return -EINVAL; | |
1512 | ||
1513 | parent = dirname_malloc(path); | |
1514 | if (!parent) | |
1515 | return -ENOMEM; | |
1516 | ||
1517 | /* Let's insist on O_DIRECTORY since the parent of a file or directory is a directory. Except if we open an | |
1518 | * O_TMPFILE file, because in that case we are actually create a regular file below the parent directory. */ | |
1519 | ||
0c21dafb | 1520 | if (FLAGS_SET(flags, O_PATH)) |
ef8becfa | 1521 | flags |= O_DIRECTORY; |
0c21dafb | 1522 | else if (!FLAGS_SET(flags, O_TMPFILE)) |
ef8becfa LP |
1523 | flags |= O_DIRECTORY|O_RDONLY; |
1524 | ||
1525 | fd = open(parent, flags, mode); | |
1526 | if (fd < 0) | |
1527 | return -errno; | |
1528 | ||
1529 | return fd; | |
1530 | } | |
ed9c0851 | 1531 | |
622e1cdb LP |
1532 | static int blockdev_is_encrypted(const char *sysfs_path, unsigned depth_left) { |
1533 | _cleanup_free_ char *p = NULL, *uuids = NULL; | |
1534 | _cleanup_closedir_ DIR *d = NULL; | |
1535 | int r, found_encrypted = false; | |
1536 | ||
1537 | assert(sysfs_path); | |
1538 | ||
1539 | if (depth_left == 0) | |
1540 | return -EINVAL; | |
1541 | ||
1542 | p = path_join(sysfs_path, "dm/uuid"); | |
1543 | if (!p) | |
1544 | return -ENOMEM; | |
1545 | ||
1546 | r = read_one_line_file(p, &uuids); | |
1547 | if (r != -ENOENT) { | |
1548 | if (r < 0) | |
1549 | return r; | |
1550 | ||
1551 | /* The DM device's uuid attribute is prefixed with "CRYPT-" if this is a dm-crypt device. */ | |
1552 | if (startswith(uuids, "CRYPT-")) | |
1553 | return true; | |
1554 | } | |
1555 | ||
1556 | /* Not a dm-crypt device itself. But maybe it is on top of one? Follow the links in the "slaves/" | |
1557 | * subdir. */ | |
1558 | ||
1559 | p = mfree(p); | |
1560 | p = path_join(sysfs_path, "slaves"); | |
1561 | if (!p) | |
1562 | return -ENOMEM; | |
1563 | ||
1564 | d = opendir(p); | |
1565 | if (!d) { | |
6b000af4 | 1566 | if (errno == ENOENT) /* Doesn't have underlying devices */ |
622e1cdb LP |
1567 | return false; |
1568 | ||
1569 | return -errno; | |
1570 | } | |
1571 | ||
1572 | for (;;) { | |
1573 | _cleanup_free_ char *q = NULL; | |
1574 | struct dirent *de; | |
1575 | ||
1576 | errno = 0; | |
1577 | de = readdir_no_dot(d); | |
1578 | if (!de) { | |
1579 | if (errno != 0) | |
1580 | return -errno; | |
1581 | ||
6b000af4 | 1582 | break; /* No more underlying devices */ |
622e1cdb LP |
1583 | } |
1584 | ||
1585 | q = path_join(p, de->d_name); | |
1586 | if (!q) | |
1587 | return -ENOMEM; | |
1588 | ||
1589 | r = blockdev_is_encrypted(q, depth_left - 1); | |
1590 | if (r < 0) | |
1591 | return r; | |
1592 | if (r == 0) /* we found one that is not encrypted? then propagate that immediately */ | |
1593 | return false; | |
1594 | ||
1595 | found_encrypted = true; | |
1596 | } | |
1597 | ||
1598 | return found_encrypted; | |
1599 | } | |
1600 | ||
ed9c0851 | 1601 | int path_is_encrypted(const char *path) { |
622e1cdb | 1602 | char p[SYS_BLOCK_PATH_MAX(NULL)]; |
ed9c0851 LP |
1603 | dev_t devt; |
1604 | int r; | |
1605 | ||
1606 | r = get_block_device(path, &devt); | |
1607 | if (r < 0) | |
1608 | return r; | |
1609 | if (r == 0) /* doesn't have a block device */ | |
1610 | return false; | |
1611 | ||
622e1cdb | 1612 | xsprintf_sys_block_path(p, NULL, devt); |
ed9c0851 | 1613 | |
622e1cdb | 1614 | return blockdev_is_encrypted(p, 10 /* safety net: maximum recursion depth */); |
ed9c0851 | 1615 | } |
10981424 LP |
1616 | |
1617 | int conservative_rename( | |
1618 | int olddirfd, const char *oldpath, | |
1619 | int newdirfd, const char *newpath) { | |
1620 | ||
1621 | _cleanup_close_ int old_fd = -1, new_fd = -1; | |
1622 | struct stat old_stat, new_stat; | |
1623 | ||
1624 | /* Renames the old path to thew new path, much like renameat() — except if both are regular files and | |
1625 | * have the exact same contents and basic file attributes already. In that case remove the new file | |
1626 | * instead. This call is useful for reducing inotify wakeups on files that are updated but don't | |
1627 | * actually change. This function is written in a style that we rather rename too often than suppress | |
1628 | * too much. i.e. whenever we are in doubt we rather rename than fail. After all reducing inotify | |
1629 | * events is an optimization only, not more. */ | |
1630 | ||
1631 | old_fd = openat(olddirfd, oldpath, O_CLOEXEC|O_RDONLY|O_NOCTTY|O_NOFOLLOW); | |
1632 | if (old_fd < 0) | |
1633 | goto do_rename; | |
1634 | ||
1635 | new_fd = openat(newdirfd, newpath, O_CLOEXEC|O_RDONLY|O_NOCTTY|O_NOFOLLOW); | |
1636 | if (new_fd < 0) | |
1637 | goto do_rename; | |
1638 | ||
1639 | if (fstat(old_fd, &old_stat) < 0) | |
1640 | goto do_rename; | |
1641 | ||
1642 | if (!S_ISREG(old_stat.st_mode)) | |
1643 | goto do_rename; | |
1644 | ||
1645 | if (fstat(new_fd, &new_stat) < 0) | |
1646 | goto do_rename; | |
1647 | ||
1648 | if (new_stat.st_ino == old_stat.st_ino && | |
1649 | new_stat.st_dev == old_stat.st_dev) | |
1650 | goto is_same; | |
1651 | ||
1652 | if (old_stat.st_mode != new_stat.st_mode || | |
1653 | old_stat.st_size != new_stat.st_size || | |
1654 | old_stat.st_uid != new_stat.st_uid || | |
1655 | old_stat.st_gid != new_stat.st_gid) | |
1656 | goto do_rename; | |
1657 | ||
1658 | for (;;) { | |
1659 | char buf1[16*1024]; | |
1660 | char buf2[sizeof(buf1) + 1]; | |
1661 | ssize_t l1, l2; | |
1662 | ||
1663 | l1 = read(old_fd, buf1, sizeof(buf1)); | |
1664 | if (l1 < 0) | |
1665 | goto do_rename; | |
1666 | ||
1667 | l2 = read(new_fd, buf2, l1 + 1); | |
1668 | if (l1 != l2) | |
1669 | goto do_rename; | |
1670 | ||
1671 | if (l1 == 0) /* EOF on both! And everything's the same so far, yay! */ | |
1672 | break; | |
1673 | ||
1674 | if (memcmp(buf1, buf2, l1) != 0) | |
1675 | goto do_rename; | |
1676 | } | |
1677 | ||
1678 | is_same: | |
1679 | /* Everything matches? Then don't rename, instead remove the source file, and leave the existing | |
1680 | * destination in place */ | |
1681 | ||
1682 | if (unlinkat(olddirfd, oldpath, 0) < 0) | |
1683 | goto do_rename; | |
1684 | ||
1685 | return 0; | |
1686 | ||
1687 | do_rename: | |
1688 | if (renameat(olddirfd, oldpath, newdirfd, newpath) < 0) | |
1689 | return -errno; | |
1690 | ||
1691 | return 1; | |
1692 | } |