1 /* $NetBSD: libdm-common.c,v 1.5 2009/12/05 11:42:24 haad Exp $ */
2
3 /*
4 * Copyright (C) 2001-2004 Sistina Software, Inc. All rights reserved.
5 * Copyright (C) 2004-2007 Red Hat, Inc. All rights reserved.
6 *
7 * This file is part of the device-mapper userspace tools.
8 *
9 * This copyrighted material is made available to anyone wishing to use,
10 * modify, copy, or redistribute it subject to the terms and conditions
11 * of the GNU Lesser General Public License v.2.1.
12 *
13 * You should have received a copy of the GNU Lesser General Public License
14 * along with this program; if not, write to the Free Software Foundation,
15 * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
16 */
17
18 #include "dmlib.h"
19 #include "libdm-targets.h"
20 #include "libdm-common.h"
21 #ifdef linux
22 #include "kdev_t.h"
23 #endif
24 #include "dm-ioctl.h"
25
26 #include <stdarg.h>
27 #include <sys/param.h>
28 #include <sys/ioctl.h>
29 #include <fcntl.h>
30 #include <dirent.h>
31
32 #ifdef UDEV_SYNC_SUPPORT
33 # include <sys/types.h>
34 # include <sys/ipc.h>
35 # include <sys/sem.h>
36 #ifdef HAVE_UDEV_QUEUE_GET_UDEV_IS_ACTIVE
37 # define LIBUDEV_I_KNOW_THE_API_IS_SUBJECT_TO_CHANGE
38 # include <libudev.h>
39 #endif
40 #endif
41
42 #ifdef linux
43 # include <linux/fs.h>
44 #endif
45
46 #ifdef HAVE_SELINUX
47 # include <selinux/selinux.h>
48 #endif
49
50 #if defined(__NetBSD__) || defined(__DragonFly__)
51 #include "libdm-netbsd.h"
52 #endif
53
54 #define DEV_DIR "/dev/"
55
56 static char _dm_dir[PATH_MAX] = DEV_DIR DM_DIR;
57
58 static int _verbose = 0;
59
60 #ifdef UDEV_SYNC_SUPPORT
61 static int _udev_running = -1;
62 static int _sync_with_udev = 1;
63 #endif
64
65 /*
66 * Library users can provide their own logging
67 * function.
68 */
69
_default_log_line(int level,const char * file __attribute ((unused)),int line __attribute ((unused)),int dm_errno,const char * f,va_list ap)70 static void _default_log_line(int level,
71 const char *file __attribute((unused)),
72 int line __attribute((unused)), int dm_errno,
73 const char *f, va_list ap)
74 {
75 int use_stderr = level & _LOG_STDERR;
76
77 level &= ~_LOG_STDERR;
78
79 if (level > _LOG_WARN && !_verbose)
80 return;
81
82 if (level < _LOG_WARN)
83 vfprintf(stderr, f, ap);
84 else
85 vfprintf(use_stderr ? stderr : stdout, f, ap);
86
87 if (level < _LOG_WARN)
88 fprintf(stderr, "\n");
89 else
90 fprintf(use_stderr ? stderr : stdout, "\n");
91 }
92
_default_log_with_errno(int level,const char * file __attribute ((unused)),int line __attribute ((unused)),int dm_errno,const char * f,...)93 static void _default_log_with_errno(int level,
94 const char *file __attribute((unused)),
95 int line __attribute((unused)), int dm_errno,
96 const char *f, ...)
97 {
98 va_list ap;
99
100 va_start(ap, f);
101 _default_log_line(level, file, line, dm_errno, f, ap);
102 va_end(ap);
103 }
104
_default_log(int level,const char * file,int line,const char * f,...)105 static void _default_log(int level, const char *file,
106 int line, const char *f, ...)
107 {
108 va_list ap;
109
110 va_start(ap, f);
111 _default_log_line(level, file, line, 0, f, ap);
112 va_end(ap);
113 }
114
115 dm_log_fn dm_log = _default_log;
116 dm_log_with_errno_fn dm_log_with_errno = _default_log_with_errno;
117
dm_log_init(dm_log_fn fn)118 void dm_log_init(dm_log_fn fn)
119 {
120 if (fn)
121 dm_log = fn;
122 else
123 dm_log = _default_log;
124
125 dm_log_with_errno = _default_log_with_errno;
126 }
127
dm_log_is_non_default(void)128 int dm_log_is_non_default(void)
129 {
130 return (dm_log == _default_log) ? 0 : 1;
131 }
132
dm_log_with_errno_init(dm_log_with_errno_fn fn)133 void dm_log_with_errno_init(dm_log_with_errno_fn fn)
134 {
135 if (fn)
136 dm_log_with_errno = fn;
137 else
138 dm_log_with_errno = _default_log_with_errno;
139
140 dm_log = _default_log;
141 }
142
dm_log_init_verbose(int level)143 void dm_log_init_verbose(int level)
144 {
145 _verbose = level;
146 }
147
_build_dev_path(char * buffer,size_t len,const char * dev_name)148 static void _build_dev_path(char *buffer, size_t len, const char *dev_name)
149 {
150 /* If there's a /, assume caller knows what they're doing */
151 if (strchr(dev_name, '/'))
152 snprintf(buffer, len, "%s", dev_name);
153 else
154 snprintf(buffer, len, "%s/%s", _dm_dir, dev_name);
155 }
156
dm_get_library_version(char * version,size_t size)157 int dm_get_library_version(char *version, size_t size)
158 {
159 strncpy(version, DM_LIB_VERSION, size);
160 return 1;
161 }
162
dm_task_create(int type)163 struct dm_task *dm_task_create(int type)
164 {
165 struct dm_task *dmt = dm_malloc(sizeof(*dmt));
166
167 if (!dmt) {
168 log_error("dm_task_create: malloc(%" PRIsize_t ") failed",
169 sizeof(*dmt));
170 return NULL;
171 }
172
173 if (!dm_check_version()) {
174 dm_free(dmt);
175 return NULL;
176 }
177
178 memset(dmt, 0, sizeof(*dmt));
179
180 dmt->type = type;
181 dmt->minor = -1;
182 dmt->major = -1;
183 dmt->allow_default_major_fallback = 1;
184 dmt->uid = DM_DEVICE_UID;
185 dmt->gid = DM_DEVICE_GID;
186 dmt->mode = DM_DEVICE_MODE;
187 dmt->no_open_count = 0;
188 dmt->read_ahead = DM_READ_AHEAD_AUTO;
189 dmt->read_ahead_flags = 0;
190 dmt->event_nr = 0;
191 dmt->cookie_set = 0;
192 dmt->query_inactive_table = 0;
193
194 return dmt;
195 }
196
197 /*
198 * Find the name associated with a given device number by scanning _dm_dir.
199 */
_find_dm_name_of_device(dev_t st_rdev)200 static char *_find_dm_name_of_device(dev_t st_rdev)
201 {
202 const char *name;
203 char path[PATH_MAX];
204 struct dirent *dirent;
205 DIR *d;
206 struct stat buf;
207 char *new_name = NULL;
208
209 if (!(d = opendir(_dm_dir))) {
210 log_sys_error("opendir", _dm_dir);
211 return NULL;
212 }
213
214 while ((dirent = readdir(d))) {
215 name = dirent->d_name;
216
217 if (!strcmp(name, ".") || !strcmp(name, ".."))
218 continue;
219
220 if (dm_snprintf(path, sizeof(path), "%s/%s", _dm_dir,
221 name) == -1) {
222 log_error("Couldn't create path for %s", name);
223 continue;
224 }
225
226 if (stat(path, &buf))
227 continue;
228
229 if (buf.st_rdev == st_rdev) {
230 if (!(new_name = dm_strdup(name)))
231 log_error("dm_task_set_name: strdup(%s) failed",
232 name);
233 break;
234 }
235 }
236
237 if (closedir(d))
238 log_sys_error("closedir", _dm_dir);
239
240 return new_name;
241 }
242
dm_task_set_name(struct dm_task * dmt,const char * name)243 int dm_task_set_name(struct dm_task *dmt, const char *name)
244 {
245 char *pos;
246 char *new_name = NULL;
247 char path[PATH_MAX];
248 struct stat st1, st2;
249
250 if (dmt->dev_name) {
251 dm_free(dmt->dev_name);
252 dmt->dev_name = NULL;
253 }
254
255 /*
256 * Path supplied for existing device?
257 */
258 if ((pos = strrchr(name, '/'))) {
259 if (dmt->type == DM_DEVICE_CREATE) {
260 log_error("Name \"%s\" invalid. It contains \"/\".", name);
261 return 0;
262 }
263
264 if (stat(name, &st1)) {
265 log_error("Device %s not found", name);
266 return 0;
267 }
268
269 /*
270 * If supplied path points to same device as last component
271 * under /dev/mapper, use that name directly. Otherwise call
272 * _find_dm_name_of_device() to scan _dm_dir for a match.
273 */
274 if (dm_snprintf(path, sizeof(path), "%s/%s", _dm_dir,
275 pos + 1) == -1) {
276 log_error("Couldn't create path for %s", pos + 1);
277 return 0;
278 }
279
280 if (!stat(path, &st2) && (st1.st_rdev == st2.st_rdev))
281 name = pos + 1;
282 else if ((new_name = _find_dm_name_of_device(st1.st_rdev)))
283 name = new_name;
284 else {
285 log_error("Device %s not found", name);
286 return 0;
287 }
288 }
289
290 if (strlen(name) >= DM_NAME_LEN) {
291 log_error("Name \"%s\" too long", name);
292 if (new_name)
293 dm_free(new_name);
294 return 0;
295 }
296
297 if (new_name)
298 dmt->dev_name = new_name;
299 else if (!(dmt->dev_name = dm_strdup(name))) {
300 log_error("dm_task_set_name: strdup(%s) failed", name);
301 return 0;
302 }
303
304 return 1;
305 }
306
dm_task_set_uuid(struct dm_task * dmt,const char * uuid)307 int dm_task_set_uuid(struct dm_task *dmt, const char *uuid)
308 {
309 if (dmt->uuid) {
310 dm_free(dmt->uuid);
311 dmt->uuid = NULL;
312 }
313
314 if (!(dmt->uuid = dm_strdup(uuid))) {
315 log_error("dm_task_set_uuid: strdup(%s) failed", uuid);
316 return 0;
317 }
318
319 return 1;
320 }
321
dm_task_set_major(struct dm_task * dmt,int major)322 int dm_task_set_major(struct dm_task *dmt, int major)
323 {
324 dmt->major = major;
325 dmt->allow_default_major_fallback = 0;
326
327 return 1;
328 }
329
dm_task_set_minor(struct dm_task * dmt,int minor)330 int dm_task_set_minor(struct dm_task *dmt, int minor)
331 {
332 dmt->minor = minor;
333
334 return 1;
335 }
336
dm_task_set_major_minor(struct dm_task * dmt,int major,int minor,int allow_default_major_fallback)337 int dm_task_set_major_minor(struct dm_task *dmt, int major, int minor,
338 int allow_default_major_fallback)
339 {
340 dmt->major = major;
341 dmt->minor = minor;
342 dmt->allow_default_major_fallback = allow_default_major_fallback;
343
344 return 1;
345 }
346
dm_task_set_uid(struct dm_task * dmt,uid_t uid)347 int dm_task_set_uid(struct dm_task *dmt, uid_t uid)
348 {
349 dmt->uid = uid;
350
351 return 1;
352 }
353
dm_task_set_gid(struct dm_task * dmt,gid_t gid)354 int dm_task_set_gid(struct dm_task *dmt, gid_t gid)
355 {
356 dmt->gid = gid;
357
358 return 1;
359 }
360
dm_task_set_mode(struct dm_task * dmt,mode_t mode)361 int dm_task_set_mode(struct dm_task *dmt, mode_t mode)
362 {
363 dmt->mode = mode;
364
365 return 1;
366 }
367
dm_task_add_target(struct dm_task * dmt,uint64_t start,uint64_t size,const char * ttype,const char * params)368 int dm_task_add_target(struct dm_task *dmt, uint64_t start, uint64_t size,
369 const char *ttype, const char *params)
370 {
371 struct target *t = create_target(start, size, ttype, params);
372
373 if (!t)
374 return 0;
375
376 if (!dmt->head)
377 dmt->head = dmt->tail = t;
378 else {
379 dmt->tail->next = t;
380 dmt->tail = t;
381 }
382
383 return 1;
384 }
385
dm_set_selinux_context(const char * path,mode_t mode)386 int dm_set_selinux_context(const char *path, mode_t mode)
387 {
388 #ifdef HAVE_SELINUX
389 security_context_t scontext;
390
391 if (is_selinux_enabled() <= 0)
392 return 1;
393
394 if (matchpathcon(path, mode, &scontext) < 0) {
395 log_error("%s: matchpathcon %07o failed: %s", path, mode,
396 strerror(errno));
397 return 0;
398 }
399
400 log_debug("Setting SELinux context for %s to %s.", path, scontext);
401
402 if ((lsetfilecon(path, scontext) < 0) && (errno != ENOTSUP)) {
403 log_sys_error("lsetfilecon", path);
404 freecon(scontext);
405 return 0;
406 }
407
408 freecon(scontext);
409 #endif
410 return 1;
411 }
412
_add_dev_node(const char * dev_name,uint32_t major,uint32_t minor,uid_t uid,gid_t gid,mode_t mode,int check_udev)413 static int _add_dev_node(const char *dev_name, uint32_t major, uint32_t minor,
414 uid_t uid, gid_t gid, mode_t mode, int check_udev)
415 {
416 char path[PATH_MAX];
417 struct stat info;
418 dev_t dev = MKDEV(major, minor);
419 mode_t old_mask;
420
421 #ifdef __NetBSD__
422 char rpath[PATH_MAX];
423 uint32_t raw_major;
424 dev_t rdev;
425 char raw_devname[DM_NAME_LEN+1]; /* r + other device name */
426
427 nbsd_get_dm_major(&raw_major,DM_CHAR_MAJOR);
428 rdev = MKDEV(raw_major,minor);
429
430 snprintf(raw_devname,sizeof(raw_devname),"r%s",dev_name);
431
432 _build_dev_path(rpath, sizeof(rpath), raw_devname);
433
434 if (stat(rpath, &info) >= 0) {
435 if (!S_ISCHR(info.st_mode)) {
436 log_error("A non-raw device file at '%s' "
437 "is already present", rpath);
438 return 0;
439 }
440
441 /* If right inode already exists we don't touch uid etc. */
442 if (info.st_rdev == rdev)
443 return 1;
444
445 if (unlink(rpath) < 0) {
446 log_error("Unable to unlink device node for '%s'",
447 raw_devname);
448 return 0;
449 }
450 }
451
452 old_mask = umask(0);
453
454 if (mknod(rpath, S_IFCHR | mode, rdev) < 0) {
455 log_error("Unable to make device node for '%s'", raw_devname);
456 return 0;
457 }
458 #elif defined(__DragonFly__)
459 _build_dev_path(path, sizeof(path), dev_name);
460 log_error("Skipping all sanity checks here");
461 return 1;
462 #endif
463
464 _build_dev_path(path, sizeof(path), dev_name);
465
466 if (stat(path, &info) >= 0) {
467 if (!S_ISBLK(info.st_mode)) {
468 log_error("A non-block device file at '%s' "
469 "is already present", path);
470 return 0;
471 }
472
473 /* If right inode already exists we don't touch uid etc. */
474 if (info.st_rdev == dev)
475 return 1;
476
477 if (unlink(path) < 0) {
478 log_error("Unable to unlink device node for '%s'",
479 dev_name);
480 return 0;
481 }
482 } else if (dm_udev_get_sync_support() && check_udev)
483 log_warn("%s not set up by udev: Falling back to direct "
484 "node creation.", path);
485
486 old_mask = umask(0);
487 if (mknod(path, S_IFBLK | mode, dev) < 0) {
488 umask(old_mask);
489 log_error("Unable to make device node for '%s'", dev_name);
490 return 0;
491 }
492 umask(old_mask);
493
494 if (chown(path, uid, gid) < 0) {
495 log_sys_error("chown", path);
496 return 0;
497 }
498
499 log_debug("Created %s", path);
500
501 if (!dm_set_selinux_context(path, S_IFBLK))
502 return 0;
503
504 return 1;
505 }
506
_rm_dev_node(const char * dev_name,int check_udev)507 static int _rm_dev_node(const char *dev_name, int check_udev)
508 {
509 char path[PATH_MAX];
510 struct stat info;
511
512 #ifdef __NetBSD__
513 char rpath[PATH_MAX];
514 char raw_devname[DM_NAME_LEN+1]; /* r + other device name */
515
516 snprintf(raw_devname,sizeof(raw_devname),"r%s",dev_name);
517
518 _build_dev_path(rpath, sizeof(rpath), raw_devname);
519
520 if (stat(rpath, &info) < 0)
521 return 1;
522
523 if (unlink(rpath) < 0) {
524 log_error("Unable to unlink device node for '%s'", raw_devname);
525 return 0;
526 }
527
528 log_debug("Removed %s", rpath);
529 #endif
530
531 _build_dev_path(path, sizeof(path), dev_name);
532
533 if (stat(path, &info) < 0)
534 return 1;
535 else if (dm_udev_get_sync_support() && check_udev)
536 log_warn("Node %s was not removed by udev. "
537 "Falling back to direct node removal.", path);
538
539 if (unlink(path) < 0) {
540 log_error("Unable to unlink device node for '%s'", dev_name);
541 return 0;
542 }
543
544 log_debug("Removed %s", path);
545
546 return 1;
547 }
548
_rename_dev_node(const char * old_name,const char * new_name,int check_udev)549 static int _rename_dev_node(const char *old_name, const char *new_name,
550 int check_udev)
551 {
552 char oldpath[PATH_MAX];
553 char newpath[PATH_MAX];
554 struct stat info;
555
556 #ifdef __NetBSD__
557 char rpath[PATH_MAX];
558 char nrpath[PATH_MAX];
559 char raw_devname[DM_NAME_LEN+1]; /* r + other device name */
560 char nraw_devname[DM_NAME_LEN+1]; /* r + other device name */
561
562 snprintf(nraw_devname,sizeof(raw_devname),"r%s",new_name);
563 snprintf(raw_devname,sizeof(raw_devname),"r%s",old_name);
564
565 _build_dev_path(nrpath, sizeof(nrpath), nraw_devname);
566 _build_dev_path(rpath, sizeof(rpath), raw_devname);
567
568 if (stat(nrpath, &info) == 0) {
569 if (S_ISBLK(info.st_mode)) {
570 log_error("A block device file at '%s' "
571 "is present where raw device should be.", newpath);
572 return 0;
573 }
574
575 if (unlink(nrpath) < 0) {
576 log_error("Unable to unlink device node for '%s'",
577 nraw_devname);
578 return 0;
579 }
580 }
581
582 if (rename(rpath, nrpath) < 0) {
583 log_error("Unable to rename device node from '%s' to '%s'",
584 raw_devname, nraw_devname);
585 return 0;
586 }
587
588 log_debug("Renamed %s to %s", rpath, nrpath);
589
590 #endif
591
592 _build_dev_path(oldpath, sizeof(oldpath), old_name);
593 _build_dev_path(newpath, sizeof(newpath), new_name);
594
595 if (stat(newpath, &info) == 0) {
596 if (!S_ISBLK(info.st_mode)) {
597 log_error("A non-block device file at '%s' "
598 "is already present", newpath);
599 return 0;
600 }
601 else if (dm_udev_get_sync_support() && check_udev) {
602 if (stat(oldpath, &info) < 0 &&
603 errno == ENOENT)
604 /* assume udev already deleted this */
605 return 1;
606 else {
607 log_warn("The node %s should have been renamed to %s "
608 "by udev but old node is still present. "
609 "Falling back to direct old node removal.",
610 oldpath, newpath);
611 return _rm_dev_node(old_name, 0);
612 }
613 }
614
615 if (unlink(newpath) < 0) {
616 if (errno == EPERM) {
617 /* devfs, entry has already been renamed */
618 return 1;
619 }
620 log_error("Unable to unlink device node for '%s'",
621 new_name);
622 return 0;
623 }
624 }
625 else if (dm_udev_get_sync_support() && check_udev)
626 log_warn("The node %s should have been renamed to %s "
627 "by udev but new node is not present. "
628 "Falling back to direct node rename.",
629 oldpath, newpath);
630
631 if (rename(oldpath, newpath) < 0) {
632 log_error("Unable to rename device node from '%s' to '%s'",
633 old_name, new_name);
634 return 0;
635 }
636
637 log_debug("Renamed %s to %s", oldpath, newpath);
638
639 return 1;
640 }
641
642 #ifdef linux
_open_dev_node(const char * dev_name)643 static int _open_dev_node(const char *dev_name)
644 {
645 int fd = -1;
646 char path[PATH_MAX];
647
648 _build_dev_path(path, sizeof(path), dev_name);
649
650 if ((fd = open(path, O_RDONLY, 0)) < 0)
651 log_sys_error("open", path);
652
653 return fd;
654 }
655
get_dev_node_read_ahead(const char * dev_name,uint32_t * read_ahead)656 int get_dev_node_read_ahead(const char *dev_name, uint32_t *read_ahead)
657 {
658 int r = 1;
659 int fd;
660 long read_ahead_long;
661
662 if (!*dev_name) {
663 log_error("Empty device name passed to BLKRAGET");
664 return 0;
665 }
666
667 if ((fd = _open_dev_node(dev_name)) < 0)
668 return_0;
669
670 if (ioctl(fd, BLKRAGET, &read_ahead_long)) {
671 log_sys_error("BLKRAGET", dev_name);
672 *read_ahead = 0;
673 r = 0;
674 } else {
675 *read_ahead = (uint32_t) read_ahead_long;
676 log_debug("%s: read ahead is %" PRIu32, dev_name, *read_ahead);
677 }
678
679 if (close(fd))
680 stack;
681
682 return r;
683 }
684
_set_read_ahead(const char * dev_name,uint32_t read_ahead)685 static int _set_read_ahead(const char *dev_name, uint32_t read_ahead)
686 {
687 int r = 1;
688 int fd;
689 long read_ahead_long = (long) read_ahead;
690
691 if (!*dev_name) {
692 log_error("Empty device name passed to BLKRAGET");
693 return 0;
694 }
695
696 if ((fd = _open_dev_node(dev_name)) < 0)
697 return_0;
698
699 log_debug("%s: Setting read ahead to %" PRIu32, dev_name, read_ahead);
700
701 if (ioctl(fd, BLKRASET, read_ahead_long)) {
702 log_sys_error("BLKRASET", dev_name);
703 r = 0;
704 }
705
706 if (close(fd))
707 stack;
708
709 return r;
710 }
711
_set_dev_node_read_ahead(const char * dev_name,uint32_t read_ahead,uint32_t read_ahead_flags)712 static int _set_dev_node_read_ahead(const char *dev_name, uint32_t read_ahead,
713 uint32_t read_ahead_flags)
714 {
715 uint32_t current_read_ahead;
716
717 if (read_ahead == DM_READ_AHEAD_AUTO)
718 return 1;
719
720 if (read_ahead == DM_READ_AHEAD_NONE)
721 read_ahead = 0;
722
723 if (read_ahead_flags & DM_READ_AHEAD_MINIMUM_FLAG) {
724 if (!get_dev_node_read_ahead(dev_name, ¤t_read_ahead))
725 return_0;
726
727 if (current_read_ahead > read_ahead) {
728 log_debug("%s: retaining kernel read ahead of %" PRIu32
729 " (requested %" PRIu32 ")",
730 dev_name, current_read_ahead, read_ahead);
731 return 1;
732 }
733 }
734
735 return _set_read_ahead(dev_name, read_ahead);
736 }
737
738 #else
739
get_dev_node_read_ahead(const char * dev_name,uint32_t * read_ahead)740 int get_dev_node_read_ahead(const char *dev_name, uint32_t *read_ahead)
741 {
742 *read_ahead = 0;
743
744 return 1;
745 }
746
_set_dev_node_read_ahead(const char * dev_name,uint32_t read_ahead,uint32_t read_ahead_flags)747 static int _set_dev_node_read_ahead(const char *dev_name, uint32_t read_ahead,
748 uint32_t read_ahead_flags)
749 {
750 return 1;
751 }
752 #endif
753
754 typedef enum {
755 NODE_ADD,
756 NODE_DEL,
757 NODE_RENAME,
758 NODE_READ_AHEAD
759 } node_op_t;
760
_do_node_op(node_op_t type,const char * dev_name,uint32_t major,uint32_t minor,uid_t uid,gid_t gid,mode_t mode,const char * old_name,uint32_t read_ahead,uint32_t read_ahead_flags,int check_udev)761 static int _do_node_op(node_op_t type, const char *dev_name, uint32_t major,
762 uint32_t minor, uid_t uid, gid_t gid, mode_t mode,
763 const char *old_name, uint32_t read_ahead,
764 uint32_t read_ahead_flags, int check_udev)
765 {
766 switch (type) {
767 case NODE_ADD:
768 return _add_dev_node(dev_name, major, minor, uid, gid,
769 mode, check_udev);
770 case NODE_DEL:
771 return _rm_dev_node(dev_name, check_udev);
772 case NODE_RENAME:
773 return _rename_dev_node(old_name, dev_name, check_udev);
774 case NODE_READ_AHEAD:
775 return _set_dev_node_read_ahead(dev_name, read_ahead,
776 read_ahead_flags);
777 }
778
779 return 1;
780 }
781
782 static DM_LIST_INIT(_node_ops);
783
784 struct node_op_parms {
785 struct dm_list list;
786 node_op_t type;
787 char *dev_name;
788 uint32_t major;
789 uint32_t minor;
790 uid_t uid;
791 gid_t gid;
792 mode_t mode;
793 uint32_t read_ahead;
794 uint32_t read_ahead_flags;
795 char *old_name;
796 int check_udev;
797 char names[0];
798 };
799
_store_str(char ** pos,char ** ptr,const char * str)800 static void _store_str(char **pos, char **ptr, const char *str)
801 {
802 strcpy(*pos, str);
803 *ptr = *pos;
804 *pos += strlen(*ptr) + 1;
805 }
806
_stack_node_op(node_op_t type,const char * dev_name,uint32_t major,uint32_t minor,uid_t uid,gid_t gid,mode_t mode,const char * old_name,uint32_t read_ahead,uint32_t read_ahead_flags,int check_udev)807 static int _stack_node_op(node_op_t type, const char *dev_name, uint32_t major,
808 uint32_t minor, uid_t uid, gid_t gid, mode_t mode,
809 const char *old_name, uint32_t read_ahead,
810 uint32_t read_ahead_flags, int check_udev)
811 {
812 struct node_op_parms *nop;
813 struct dm_list *noph, *nopht;
814 size_t len = strlen(dev_name) + strlen(old_name) + 2;
815 char *pos;
816
817 /*
818 * Ignore any outstanding operations on the node if deleting it
819 */
820 if (type == NODE_DEL) {
821 dm_list_iterate_safe(noph, nopht, &_node_ops) {
822 nop = dm_list_item(noph, struct node_op_parms);
823 if (!strcmp(dev_name, nop->dev_name)) {
824 dm_list_del(&nop->list);
825 dm_free(nop);
826 }
827 }
828 }
829
830 if (!(nop = dm_malloc(sizeof(*nop) + len))) {
831 log_error("Insufficient memory to stack mknod operation");
832 return 0;
833 }
834
835 pos = nop->names;
836 nop->type = type;
837 nop->major = major;
838 nop->minor = minor;
839 nop->uid = uid;
840 nop->gid = gid;
841 nop->mode = mode;
842 nop->read_ahead = read_ahead;
843 nop->read_ahead_flags = read_ahead_flags;
844 nop->check_udev = check_udev;
845
846 _store_str(&pos, &nop->dev_name, dev_name);
847 _store_str(&pos, &nop->old_name, old_name);
848
849 dm_list_add(&_node_ops, &nop->list);
850
851 return 1;
852 }
853
_pop_node_ops(void)854 static void _pop_node_ops(void)
855 {
856 struct dm_list *noph, *nopht;
857 struct node_op_parms *nop;
858
859 dm_list_iterate_safe(noph, nopht, &_node_ops) {
860 nop = dm_list_item(noph, struct node_op_parms);
861 _do_node_op(nop->type, nop->dev_name, nop->major, nop->minor,
862 nop->uid, nop->gid, nop->mode, nop->old_name,
863 nop->read_ahead, nop->read_ahead_flags,
864 nop->check_udev);
865 dm_list_del(&nop->list);
866 dm_free(nop);
867 }
868 }
869
add_dev_node(const char * dev_name,uint32_t major,uint32_t minor,uid_t uid,gid_t gid,mode_t mode,int check_udev)870 int add_dev_node(const char *dev_name, uint32_t major, uint32_t minor,
871 uid_t uid, gid_t gid, mode_t mode, int check_udev)
872 {
873 log_debug("%s: Stacking NODE_ADD (%" PRIu32 ",%" PRIu32 ") %u:%u 0%o",
874 dev_name, major, minor, uid, gid, mode);
875
876 return _stack_node_op(NODE_ADD, dev_name, major, minor, uid,
877 gid, mode, "", 0, 0, check_udev);
878 }
879
rename_dev_node(const char * old_name,const char * new_name,int check_udev)880 int rename_dev_node(const char *old_name, const char *new_name, int check_udev)
881 {
882 log_debug("%s: Stacking NODE_RENAME to %s", old_name, new_name);
883
884 return _stack_node_op(NODE_RENAME, new_name, 0, 0, 0,
885 0, 0, old_name, 0, 0, check_udev);
886 }
887
rm_dev_node(const char * dev_name,int check_udev)888 int rm_dev_node(const char *dev_name, int check_udev)
889 {
890 log_debug("%s: Stacking NODE_DEL (replaces other stacked ops)", dev_name);
891
892 return _stack_node_op(NODE_DEL, dev_name, 0, 0, 0,
893 0, 0, "", 0, 0, check_udev);
894 }
895
set_dev_node_read_ahead(const char * dev_name,uint32_t read_ahead,uint32_t read_ahead_flags)896 int set_dev_node_read_ahead(const char *dev_name, uint32_t read_ahead,
897 uint32_t read_ahead_flags)
898 {
899 if (read_ahead == DM_READ_AHEAD_AUTO)
900 return 1;
901
902 log_debug("%s: Stacking NODE_READ_AHEAD %" PRIu32 " (flags=%" PRIu32
903 ")", dev_name, read_ahead, read_ahead_flags);
904
905 return _stack_node_op(NODE_READ_AHEAD, dev_name, 0, 0, 0, 0,
906 0, "", read_ahead, read_ahead_flags, 0);
907 }
908
update_devs(void)909 void update_devs(void)
910 {
911 _pop_node_ops();
912 }
913
dm_set_dev_dir(const char * dev_dir)914 int dm_set_dev_dir(const char *dev_dir)
915 {
916 size_t len;
917 const char *slash;
918 if (*dev_dir != '/') {
919 log_debug("Invalid dev_dir value, %s: "
920 "not an absolute name.", dev_dir);
921 return 0;
922 }
923
924 len = strlen(dev_dir);
925 slash = dev_dir[len-1] == '/' ? "" : "/";
926
927 if (snprintf(_dm_dir, sizeof _dm_dir, "%s%s%s", dev_dir, slash, DM_DIR)
928 >= sizeof _dm_dir) {
929 log_debug("Invalid dev_dir value, %s: name too long.", dev_dir);
930 return 0;
931 }
932
933 return 1;
934 }
935
dm_dir(void)936 const char *dm_dir(void)
937 {
938 return _dm_dir;
939 }
940
dm_mknodes(const char * name)941 int dm_mknodes(const char *name)
942 {
943 struct dm_task *dmt;
944 int r = 0;
945
946 if (!(dmt = dm_task_create(DM_DEVICE_MKNODES)))
947 return 0;
948
949 if (name && !dm_task_set_name(dmt, name))
950 goto out;
951
952 if (!dm_task_no_open_count(dmt))
953 goto out;
954
955 r = dm_task_run(dmt);
956
957 out:
958 dm_task_destroy(dmt);
959 return r;
960 }
961
dm_driver_version(char * version,size_t size)962 int dm_driver_version(char *version, size_t size)
963 {
964 struct dm_task *dmt;
965 int r = 0;
966
967 if (!(dmt = dm_task_create(DM_DEVICE_VERSION)))
968 return 0;
969
970 if (!dm_task_run(dmt))
971 log_error("Failed to get driver version");
972
973 if (!dm_task_get_driver_version(dmt, version, size))
974 goto out;
975
976 r = 1;
977
978 out:
979 dm_task_destroy(dmt);
980 return r;
981 }
982
983 #ifndef UDEV_SYNC_SUPPORT
dm_udev_set_sync_support(int sync_with_udev)984 void dm_udev_set_sync_support(int sync_with_udev)
985 {
986 }
987
dm_udev_get_sync_support(void)988 int dm_udev_get_sync_support(void)
989 {
990 return 0;
991 }
992
dm_task_set_cookie(struct dm_task * dmt,uint32_t * cookie,uint16_t flags)993 int dm_task_set_cookie(struct dm_task *dmt, uint32_t *cookie, uint16_t flags)
994 {
995 if (dm_cookie_supported())
996 dmt->event_nr = flags << DM_UDEV_FLAGS_SHIFT;
997 *cookie = 0;
998
999 return 1;
1000 }
1001
dm_udev_complete(uint32_t cookie)1002 int dm_udev_complete(uint32_t cookie)
1003 {
1004 return 1;
1005 }
1006
dm_udev_wait(uint32_t cookie)1007 int dm_udev_wait(uint32_t cookie)
1008 {
1009 return 1;
1010 }
1011
1012 #else /* UDEV_SYNC_SUPPORT */
1013
1014
_check_udev_is_running(void)1015 static int _check_udev_is_running(void)
1016 {
1017
1018 # ifndef HAVE_UDEV_QUEUE_GET_UDEV_IS_ACTIVE
1019
1020 log_debug("Could not get udev state because libudev library "
1021 "was not found and it was not compiled in. "
1022 "Assuming udev is not running.");
1023 return 0;
1024
1025 # else /* HAVE_UDEV_QUEUE_GET_UDEV_IS_ACTIVE */
1026
1027 struct udev *udev;
1028 struct udev_queue *udev_queue;
1029 int r;
1030
1031 if (!(udev = udev_new()))
1032 goto_bad;
1033
1034 if (!(udev_queue = udev_queue_new(udev))) {
1035 udev_unref(udev);
1036 goto_bad;
1037 }
1038
1039 if (!(r = udev_queue_get_udev_is_active(udev_queue)))
1040 log_debug("Udev is not running. "
1041 "Not using udev synchronisation code.");
1042
1043 udev_queue_unref(udev_queue);
1044 udev_unref(udev);
1045
1046 return r;
1047
1048 bad:
1049 log_error("Could not get udev state. Assuming udev is not running.");
1050 return 0;
1051
1052 # endif /* HAVE_UDEV_QUEUE_GET_UDEV_IS_ACTIVE */
1053
1054 }
1055
dm_udev_set_sync_support(int sync_with_udev)1056 void dm_udev_set_sync_support(int sync_with_udev)
1057 {
1058 if (_udev_running < 0)
1059 _udev_running = _check_udev_is_running();
1060
1061 _sync_with_udev = sync_with_udev;
1062 }
1063
dm_udev_get_sync_support(void)1064 int dm_udev_get_sync_support(void)
1065 {
1066 if (_udev_running < 0)
1067 _udev_running = _check_udev_is_running();
1068
1069 return dm_cookie_supported() && _udev_running && _sync_with_udev;
1070 }
1071
_get_cookie_sem(uint32_t cookie,int * semid)1072 static int _get_cookie_sem(uint32_t cookie, int *semid)
1073 {
1074 if (cookie >> 16 != DM_COOKIE_MAGIC) {
1075 log_error("Could not continue to access notification "
1076 "semaphore identified by cookie value %"
1077 PRIu32 " (0x%x). Incorrect cookie prefix.",
1078 cookie, cookie);
1079 return 0;
1080 }
1081
1082 if ((*semid = semget((key_t) cookie, 1, 0)) >= 0)
1083 return 1;
1084
1085 switch (errno) {
1086 case ENOENT:
1087 log_error("Could not find notification "
1088 "semaphore identified by cookie "
1089 "value %" PRIu32 " (0x%x)",
1090 cookie, cookie);
1091 break;
1092 case EACCES:
1093 log_error("No permission to access "
1094 "notificaton semaphore identified "
1095 "by cookie value %" PRIu32 " (0x%x)",
1096 cookie, cookie);
1097 break;
1098 default:
1099 log_error("Failed to access notification "
1100 "semaphore identified by cookie "
1101 "value %" PRIu32 " (0x%x): %s",
1102 cookie, cookie, strerror(errno));
1103 break;
1104 }
1105
1106 return 0;
1107 }
1108
_udev_notify_sem_inc(uint32_t cookie,int semid)1109 static int _udev_notify_sem_inc(uint32_t cookie, int semid)
1110 {
1111 struct sembuf sb = {0, 1, 0};
1112
1113 if (semop(semid, &sb, 1) < 0) {
1114 log_error("semid %d: semop failed for cookie 0x%" PRIx32 ": %s",
1115 semid, cookie, strerror(errno));
1116 return 0;
1117 }
1118
1119 log_debug("Udev cookie 0x%" PRIx32 " (semid %d) incremented",
1120 cookie, semid);
1121
1122 return 1;
1123 }
1124
_udev_notify_sem_dec(uint32_t cookie,int semid)1125 static int _udev_notify_sem_dec(uint32_t cookie, int semid)
1126 {
1127 struct sembuf sb = {0, -1, IPC_NOWAIT};
1128
1129 if (semop(semid, &sb, 1) < 0) {
1130 switch (errno) {
1131 case EAGAIN:
1132 log_error("semid %d: semop failed for cookie "
1133 "0x%" PRIx32 ": "
1134 "incorrect semaphore state",
1135 semid, cookie);
1136 break;
1137 default:
1138 log_error("semid %d: semop failed for cookie "
1139 "0x%" PRIx32 ": %s",
1140 semid, cookie, strerror(errno));
1141 break;
1142 }
1143 return 0;
1144 }
1145
1146 log_debug("Udev cookie 0x%" PRIx32 " (semid %d) decremented",
1147 cookie, semid);
1148
1149 return 1;
1150 }
1151
_udev_notify_sem_destroy(uint32_t cookie,int semid)1152 static int _udev_notify_sem_destroy(uint32_t cookie, int semid)
1153 {
1154 if (semctl(semid, 0, IPC_RMID, 0) < 0) {
1155 log_error("Could not cleanup notification semaphore "
1156 "identified by cookie value %" PRIu32 " (0x%x): %s",
1157 cookie, cookie, strerror(errno));
1158 return 0;
1159 }
1160
1161 log_debug("Udev cookie 0x%" PRIx32 " (semid %d) destroyed", cookie,
1162 semid);
1163
1164 return 1;
1165 }
1166
_udev_notify_sem_create(uint32_t * cookie,int * semid)1167 static int _udev_notify_sem_create(uint32_t *cookie, int *semid)
1168 {
1169 int fd;
1170 int gen_semid;
1171 uint16_t base_cookie;
1172 uint32_t gen_cookie;
1173
1174 if ((fd = open("/dev/urandom", O_RDONLY)) < 0) {
1175 log_error("Failed to open /dev/urandom "
1176 "to create random cookie value");
1177 *cookie = 0;
1178 return 0;
1179 }
1180
1181 /* Generate random cookie value. Be sure it is unique and non-zero. */
1182 do {
1183 /* FIXME Handle non-error returns from read(). Move _io() into libdm? */
1184 if (read(fd, &base_cookie, sizeof(base_cookie)) != sizeof(base_cookie)) {
1185 log_error("Failed to initialize notification cookie");
1186 goto bad;
1187 }
1188
1189 gen_cookie = DM_COOKIE_MAGIC << 16 | base_cookie;
1190
1191 if (base_cookie && (gen_semid = semget((key_t) gen_cookie,
1192 1, 0600 | IPC_CREAT | IPC_EXCL)) < 0) {
1193 switch (errno) {
1194 case EEXIST:
1195 /* if the semaphore key exists, we
1196 * simply generate another random one */
1197 base_cookie = 0;
1198 break;
1199 case ENOMEM:
1200 log_error("Not enough memory to create "
1201 "notification semaphore");
1202 goto bad;
1203 case ENOSPC:
1204 log_error("Limit for the maximum number "
1205 "of semaphores reached. You can "
1206 "check and set the limits in "
1207 "/proc/sys/kernel/sem.");
1208 goto bad;
1209 default:
1210 log_error("Failed to create notification "
1211 "semaphore: %s", strerror(errno));
1212 goto bad;
1213 }
1214 }
1215 } while (!base_cookie);
1216
1217 log_debug("Udev cookie 0x%" PRIx32 " (semid %d) created",
1218 gen_cookie, gen_semid);
1219
1220 if (semctl(gen_semid, 0, SETVAL, 1) < 0) {
1221 log_error("semid %d: semctl failed: %s", gen_semid, strerror(errno));
1222 /* We have to destroy just created semaphore
1223 * so it won't stay in the system. */
1224 (void) _udev_notify_sem_destroy(gen_cookie, gen_semid);
1225 goto bad;
1226 }
1227
1228 log_debug("Udev cookie 0x%" PRIx32 " (semid %d) incremented",
1229 gen_cookie, gen_semid);
1230
1231 if (close(fd))
1232 stack;
1233
1234 *semid = gen_semid;
1235 *cookie = gen_cookie;
1236
1237 return 1;
1238
1239 bad:
1240 if (close(fd))
1241 stack;
1242
1243 *cookie = 0;
1244
1245 return 0;
1246 }
1247
dm_task_set_cookie(struct dm_task * dmt,uint32_t * cookie,uint16_t flags)1248 int dm_task_set_cookie(struct dm_task *dmt, uint32_t *cookie, uint16_t flags)
1249 {
1250 int semid;
1251
1252 if (dm_cookie_supported())
1253 dmt->event_nr = flags << DM_UDEV_FLAGS_SHIFT;
1254
1255 if (!dm_udev_get_sync_support()) {
1256 *cookie = 0;
1257 return 1;
1258 }
1259
1260 if (*cookie) {
1261 if (!_get_cookie_sem(*cookie, &semid))
1262 goto_bad;
1263 } else if (!_udev_notify_sem_create(cookie, &semid))
1264 goto_bad;
1265
1266 if (!_udev_notify_sem_inc(*cookie, semid)) {
1267 log_error("Could not set notification semaphore "
1268 "identified by cookie value %" PRIu32 " (0x%x)",
1269 *cookie, *cookie);
1270 goto bad;
1271 }
1272
1273 dmt->event_nr |= ~DM_UDEV_FLAGS_MASK & *cookie;
1274 dmt->cookie_set = 1;
1275
1276 log_debug("Udev cookie 0x%" PRIx32 " (semid %d) assigned to dm_task "
1277 "with flags 0x%" PRIx16, *cookie, semid, flags);
1278
1279 return 1;
1280
1281 bad:
1282 dmt->event_nr = 0;
1283 return 0;
1284 }
1285
dm_udev_complete(uint32_t cookie)1286 int dm_udev_complete(uint32_t cookie)
1287 {
1288 int semid;
1289
1290 if (!cookie || !dm_udev_get_sync_support())
1291 return 1;
1292
1293 if (!_get_cookie_sem(cookie, &semid))
1294 return_0;
1295
1296 if (!_udev_notify_sem_dec(cookie, semid)) {
1297 log_error("Could not signal waiting process using notification "
1298 "semaphore identified by cookie value %" PRIu32 " (0x%x)",
1299 cookie, cookie);
1300 return 0;
1301 }
1302
1303 return 1;
1304 }
1305
dm_udev_wait(uint32_t cookie)1306 int dm_udev_wait(uint32_t cookie)
1307 {
1308 int semid;
1309 struct sembuf sb = {0, 0, 0};
1310
1311 if (!cookie || !dm_udev_get_sync_support())
1312 return 1;
1313
1314 if (!_get_cookie_sem(cookie, &semid))
1315 return_0;
1316
1317 if (!_udev_notify_sem_dec(cookie, semid)) {
1318 log_error("Failed to set a proper state for notification "
1319 "semaphore identified by cookie value %" PRIu32 " (0x%x) "
1320 "to initialize waiting for incoming notifications.",
1321 cookie, cookie);
1322 (void) _udev_notify_sem_destroy(cookie, semid);
1323 return 0;
1324 }
1325
1326 log_debug("Udev cookie 0x%" PRIx32 " (semid %d): Waiting for zero",
1327 cookie, semid);
1328
1329 repeat_wait:
1330 if (semop(semid, &sb, 1) < 0) {
1331 if (errno == EINTR)
1332 goto repeat_wait;
1333 else if (errno == EIDRM)
1334 return 1;
1335
1336 log_error("Could not set wait state for notification semaphore "
1337 "identified by cookie value %" PRIu32 " (0x%x): %s",
1338 cookie, cookie, strerror(errno));
1339 (void) _udev_notify_sem_destroy(cookie, semid);
1340 return 0;
1341 }
1342
1343 return _udev_notify_sem_destroy(cookie, semid);
1344 }
1345
1346 #endif /* UDEV_SYNC_SUPPORT */
1347