1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
|
/*
* libudev - interface to udev device information
*
* Copyright (C) 2008 Kay Sievers <kay.sievers@vrfy.org>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <dirent.h>
#include <fcntl.h>
#include <sys/stat.h>
#include "libudev.h"
#include "libudev-private.h"
struct udev_device {
int refcount;
struct udev *udev;
struct udev_device *parent_device;
char *syspath;
const char *devpath;
const char *sysname;
char *devname;
char *subsystem;
struct list_head link_list;
struct list_head env_list;
char *action;
char *driver;
char *devpath_old;
char *physdevpath;
int timeout;
dev_t devnum;
unsigned long long int seqnum;
int num_fake_partitions;
int devlink_priority;
int ignore_remove;
struct list_head attr_list;
};
static size_t syspath_to_db_path(struct udev_device *udev_device, char *filename, size_t len)
{
size_t start;
/* translate to location of db file */
util_strlcpy(filename, udev_get_dev_path(udev_device->udev), len);
start = util_strlcat(filename, "/.udev/db/", len);
util_strlcat(filename, udev_device->devpath, len);
return util_path_encode(&filename[start], len - start);
}
static int device_read_db(struct udev_device *udev_device)
{
struct stat stats;
char filename[UTIL_PATH_SIZE];
char line[UTIL_LINE_SIZE];
FILE *f;
int rc = 0;
syspath_to_db_path(udev_device, filename, sizeof(filename));
if (lstat(filename, &stats) != 0) {
info(udev_device->udev, "no db file to read %s: %s\n", filename, strerror(errno));
return -1;
}
if ((stats.st_mode & S_IFMT) == S_IFLNK) {
char target[UTIL_PATH_SIZE];
int target_len;
info(udev_device->udev, "found a symlink as db file\n");
target_len = readlink(filename, target, sizeof(target));
if (target_len > 0)
target[target_len] = '\0';
else {
info(udev_device->udev, "error reading db link %s: %s\n", filename, strerror(errno));
return -1;
}
dbg(udev_device->udev, "db link points to '%s'\n", target);
if (asprintf(&udev_device->devname, "%s/%s", udev_get_dev_path(udev_device->udev), target) < 0)
return -ENOMEM;
return 0;
}
f = fopen(filename, "r");
if (f == NULL) {
info(udev_device->udev, "error reading db file %s: %s\n", filename, strerror(errno));
return -1;
}
while (fgets(line, sizeof(line), f)) {
ssize_t len;
const char *val;
unsigned int maj, min;
len = strlen(line);
if (len < 4)
break;
line[len-1] = '\0';
val = &line[2];
switch(line[0]) {
case 'N':
asprintf(&udev_device->devname, "%s/%s", udev_get_dev_path(udev_device->udev), val);
break;
case 'M':
sscanf(val, "%u:%u", &maj, &min);
device_set_devnum(udev_device, makedev(maj, min));
break;
case 'S':
util_strlcpy(filename, udev_get_dev_path(udev_device->udev), sizeof(filename));
util_strlcat(filename, "/", sizeof(filename));
util_strlcat(filename, val, sizeof(filename));
device_add_devlink(udev_device, filename);
break;
case 'L':
device_set_devlink_priority(udev_device, atoi(val));
break;
case 'T':
device_set_timeout(udev_device, atoi(val));
break;
case 'A':
device_set_num_fake_partitions(udev_device, atoi(val));
break;
case 'R':
device_set_ignore_remove(udev_device, atoi(val));
break;
case 'E':
device_add_property_from_string(udev_device, val);
break;
}
}
fclose(f);
return rc;
}
struct udev_device *device_init(struct udev *udev)
{
struct udev_device *udev_device;
if (udev == NULL)
return NULL;
udev_device = malloc(sizeof(struct udev_device));
if (udev_device == NULL)
return NULL;
memset(udev_device, 0x00, sizeof(struct udev_device));
udev_device->refcount = 1;
udev_device->udev = udev;
INIT_LIST_HEAD(&udev_device->link_list);
INIT_LIST_HEAD(&udev_device->env_list);
INIT_LIST_HEAD(&udev_device->attr_list);
info(udev_device->udev, "udev_device: %p created\n", udev_device);
return udev_device;
}
/**
* udev_device_new_from_syspath:
* @udev: udev library context
* @syspath: sys device path including sys directory
*
* Create new udev device, and fill in information from the sys
* device and the udev database entry. The sypath is the absolute
* path to the device, including the sys mount point.
*
* The initial refcount is 1, and needs to be decremented to
* release the ressources of the udev device.
*
* Returns: a new udev device, or #NULL, if it does not exist
**/
struct udev_device *udev_device_new_from_syspath(struct udev *udev, const char *syspath)
{
char path[UTIL_PATH_SIZE];
struct stat statbuf;
struct udev_device *udev_device;
if (udev == NULL)
return NULL;
if (syspath == NULL)
return NULL;
util_strlcpy(path, syspath, sizeof(path));
util_strlcat(path, "/uevent", sizeof(path));
if (stat(path, &statbuf) != 0) {
info(udev, "not a device :%s\n", syspath);
return NULL;
}
udev_device = device_init(udev);
if (udev_device == NULL)
return NULL;
/* resolve possible symlink to real path */
util_strlcpy(path, syspath, sizeof(path));
util_resolve_sys_link(udev, path, sizeof(path));
device_set_syspath(udev_device, path);
info(udev, "device %p has devpath '%s'\n", udev_device, udev_device_get_devpath(udev_device));
if (device_read_db(udev_device) >= 0)
info(udev, "device %p filled with udev database data\n", udev_device);
return udev_device;
}
static struct udev_device *device_new_from_parent(struct udev_device *udev_device)
{
struct udev_device *udev_device_parent = NULL;
char path[UTIL_PATH_SIZE];
char *pos;
if (udev_device == NULL)
return NULL;
util_strlcpy(path, udev_device->syspath, sizeof(path));
while (1) {
pos = strrchr(path, '/');
if (pos == path || pos == NULL)
break;
pos[0] = '\0';
udev_device_parent = udev_device_new_from_syspath(udev_device->udev, path);
if (udev_device_parent != NULL)
return udev_device_parent;
}
/* follow "device" link in deprecated sys /sys/class/ layout */
if (strncmp(udev_device->devpath, "/class/", 7) == 0) {
util_strlcpy(path, udev_device->syspath, sizeof(path));
util_strlcat(path, "/device", sizeof(path));
if (util_resolve_sys_link(udev_device->udev, path, sizeof(path)) == 0) {
udev_device_parent = udev_device_new_from_syspath(udev_device->udev, path);
if (udev_device_parent != NULL)
return udev_device_parent;
}
}
return NULL;
}
struct udev_device *udev_device_get_parent(struct udev_device *udev_device)
{
if (udev_device->parent_device != NULL) {
info(udev_device->udev, "returning existing parent %p\n", udev_device->parent_device);
return udev_device->parent_device;
}
udev_device->parent_device = device_new_from_parent(udev_device);
return udev_device->parent_device;
}
/**
* udev_device_get_udev:
* @udev_device: udev device
*
* Retrieve the udev library context the device was created with.
*
* Returns: the udev library context
**/
struct udev *udev_device_get_udev(struct udev_device *udev_device)
{
if (udev_device == NULL)
return NULL;
return udev_device->udev;
}
/**
* udev_device_ref:
* @udev_device: udev device
*
* Take a reference of a udev device.
*
* Returns: the passed udev device
**/
struct udev_device *udev_device_ref(struct udev_device *udev_device)
{
if (udev_device == NULL)
return NULL;
udev_device->refcount++;
return udev_device;
}
/**
* udev_device_unref:
* @udev_device: udev device
*
* Drop a reference of a udev device. If the refcount reaches zero,
* the ressources of the device will be released.
*
**/
void udev_device_unref(struct udev_device *udev_device)
{
if (udev_device == NULL)
return;
udev_device->refcount--;
if (udev_device->refcount > 0)
return;
if (udev_device->parent_device != NULL)
udev_device_unref(udev_device->parent_device);
free(udev_device->syspath);
free(udev_device->devname);
free(udev_device->subsystem);
util_name_list_cleanup(udev_device->udev, &udev_device->link_list);
util_name_list_cleanup(udev_device->udev, &udev_device->env_list);
free(udev_device->action);
free(udev_device->driver);
free(udev_device->devpath_old);
free(udev_device->physdevpath);
util_name_list_cleanup(udev_device->udev, &udev_device->attr_list);
info(udev_device->udev, "udev_device: %p released\n", udev_device);
free(udev_device);
}
/**
* udev_device_get_devpath:
* @udev_device: udev device
*
* Retrieve the kernel devpath value of the udev device. The path
* does not contain the sys mount point, and starts with a '/'.
*
* Returns: the devpath of the udev device
**/
const char *udev_device_get_devpath(struct udev_device *udev_device)
{
if (udev_device == NULL)
return NULL;
return udev_device->devpath;
}
/**
* udev_device_get_syspath:
* @udev_device: udev device
*
* Retrieve the sys path of the udev device. The path is an
* absolute path and starts with the sys mount point.
*
* Returns: the sys path of the udev device
**/
const char *udev_device_get_syspath(struct udev_device *udev_device)
{
if (udev_device == NULL)
return NULL;
return udev_device->syspath;
}
const char *udev_device_get_sysname(struct udev_device *udev_device)
{
if (udev_device == NULL)
return NULL;
return udev_device->sysname;
}
/**
* udev_device_get_devname:
* @udev_device: udev device
*
* Retrieve the device node file name belonging to the udev device.
* The path is an absolute path, and starts with the device directory.
*
* Returns: the device node file name of the udev device, or #NULL if no device node exists
**/
const char *udev_device_get_devname(struct udev_device *udev_device)
{
if (udev_device == NULL)
return NULL;
return udev_device->devname;
}
/**
* udev_device_get_subsystem:
* @udev_device: udev device
*
* Retrieve the subsystem string of the udev device. The string does not
* contain any "/".
*
* Returns: the subsystem name of the udev device, or #NULL if it can not be determined
**/
const char *udev_device_get_subsystem(struct udev_device *udev_device)
{
char subsystem[UTIL_NAME_SIZE];
if (udev_device == NULL)
return NULL;
if (udev_device->subsystem != NULL)
return udev_device->subsystem;
/* read "subsytem" link */
if (util_get_sys_subsystem(udev_device->udev, udev_device->syspath, subsystem, sizeof(subsystem)) > 0) {
udev_device->subsystem = strdup(subsystem);
return udev_device->subsystem;
}
/* implicit names */
if (strncmp(udev_device->devpath, "/module/", 8) == 0) {
udev_device->subsystem = strdup("module");
return udev_device->subsystem;
}
if (strstr(udev_device->devpath, "/drivers/") != NULL) {
udev_device->subsystem = strdup("drivers");
return udev_device->subsystem;
}
if (strncmp(udev_device->devpath, "/subsystem/", 11) == 0 ||
strncmp(udev_device->devpath, "/class/", 7) == 0 ||
strncmp(udev_device->devpath, "/bus/", 5) == 0) {
udev_device->subsystem = strdup("subsystem");
return udev_device->subsystem;
}
return NULL;
}
/**
* udev_device_get_devlinks:
* @udev_device: udev device
* @cb: function to be called for every device link found
* @data: data to be passed to the function
*
* Retrieve the device links pointing to the device file of the
* udev device. For every device link, the passed function will be
* called with the device link string.
* The path is an absolute path, and starts with the device directory.
* If the function returns 1, remaning device links will be ignored.
*
* Returns: the number of device links passed to the caller, or a negative value on error
**/
int udev_device_get_devlinks(struct udev_device *udev_device,
int (*cb)(struct udev_device *udev_device, const char *value, void *data),
void *data)
{
struct util_name_entry *name_loop;
int count = 0;
if (udev_device == NULL)
return -1;
list_for_each_entry(name_loop, &udev_device->link_list, node) {
count++;
if (cb(udev_device, name_loop->name, data) != 0)
break;
}
return count;
}
/**
* udev_device_get_properties:
* @udev_device: udev device
* @cb: function to be called for every property found
* @data: data to be passed to the function
*
* Retrieve the property key/value pairs belonging to the
* udev device. For every key/value pair, the passed function will be
* called. If the function returns 1, remaning properties will be
* ignored.
*
* Returns: the number of properties passed to the caller, or a negative value on error
**/
int udev_device_get_properties(struct udev_device *udev_device,
int (*cb)(struct udev_device *udev_device, const char *key, const char *value, void *data),
void *data)
{
struct util_name_entry *name_loop;
int count = 0;
if (udev_device == NULL)
return -1;
list_for_each_entry(name_loop, &udev_device->env_list, node) {
count++;
if (cb(udev_device, name_loop->name, name_loop->value, data) != 0)
break;
}
return count;
}
const char *udev_device_get_driver(struct udev_device *udev_device)
{
char driver[UTIL_NAME_SIZE];
if (udev_device == NULL)
return NULL;
if (udev_device->driver != NULL)
return udev_device->driver;
if (util_get_sys_driver(udev_device->udev, udev_device->syspath, driver, sizeof(driver)) < 2)
return NULL;
udev_device->driver = strdup(driver);
return udev_device->driver;
}
dev_t udev_device_get_devnum(struct udev_device *udev_device)
{
if (udev_device == NULL)
return makedev(0, 0);
return udev_device->devnum;
}
const char *udev_device_get_action(struct udev_device *udev_device)
{
if (udev_device == NULL)
return NULL;
return udev_device->action;
}
unsigned long long int udev_device_get_seqnum(struct udev_device *udev_device)
{
if (udev_device == NULL)
return 0;
return udev_device->seqnum;
}
const char *udev_device_get_attr_value(struct udev_device *udev_device, const char *attr)
{
struct util_name_entry *name_loop;
char path[UTIL_PATH_SIZE];
char value[UTIL_NAME_SIZE];
struct stat statbuf;
int fd;
ssize_t size;
const char *val = NULL;
/* look for possibly already cached result */
list_for_each_entry(name_loop, &udev_device->attr_list, node) {
if (strcmp(name_loop->name, attr) == 0) {
info(udev_device->udev, "'%s' in cache '%s'\n", attr, name_loop->value);
return name_loop->value;
}
}
util_strlcpy(path, udev_device_get_syspath(udev_device), sizeof(path));
util_strlcat(path, "/", sizeof(path));
util_strlcat(path, attr, sizeof(path));
if (lstat(path, &statbuf) != 0) {
info(udev_device->udev, "stat '%s' failed: %s\n", path, strerror(errno));
goto out;
}
if (S_ISLNK(statbuf.st_mode)) {
/* links return the last element of the target path */
char target[UTIL_NAME_SIZE];
int len;
char *pos;
len = readlink(path, target, sizeof(target));
if (len > 0) {
target[len] = '\0';
pos = strrchr(target, '/');
if (pos != NULL) {
pos = &pos[1];
info(udev_device->udev, "cache '%s' with link value '%s'\n", attr, pos);
val = util_name_list_add(udev_device->udev, &udev_device->attr_list, attr, pos, 0)->value;
}
}
goto out;
}
/* skip directories */
if (S_ISDIR(statbuf.st_mode))
goto out;
/* skip non-readable files */
if ((statbuf.st_mode & S_IRUSR) == 0)
goto out;
/* read attribute value */
fd = open(path, O_RDONLY);
if (fd < 0) {
info(udev_device->udev, "attribute '%s' can not be opened\n", path);
goto out;
}
size = read(fd, value, sizeof(value));
close(fd);
if (size < 0)
goto out;
if (size == sizeof(value))
goto out;
/* got a valid value, store it in cache and return it */
value[size] = '\0';
util_remove_trailing_chars(value, '\n');
info(udev_device->udev, "'%s' has attribute value '%s'\n", path, value);
val = util_name_list_add(udev_device->udev, &udev_device->attr_list, attr, value, 0)->value;
out:
return val;
}
int device_set_syspath(struct udev_device *udev_device, const char *syspath)
{
const char *pos;
udev_device->syspath = strdup(syspath);
if (udev_device->syspath == NULL)
return -ENOMEM;
udev_device->devpath = &udev_device->syspath[strlen(udev_get_sys_path(udev_device->udev))];
pos = strrchr(udev_device->syspath, '/');
if (pos == NULL)
return -EINVAL;
udev_device->sysname = &pos[1];
return 0;
}
int device_set_subsystem(struct udev_device *udev_device, const char *subsystem)
{
udev_device->subsystem = strdup(subsystem);
if (udev_device->subsystem == NULL)
return -1;
return 0;
}
int device_set_devname(struct udev_device *udev_device, const char *devname)
{
udev_device->devname = strdup(devname);
if (udev_device->devname == NULL)
return -ENOMEM;
return 0;
}
int device_add_devlink(struct udev_device *udev_device, const char *devlink)
{
if (util_name_list_add(udev_device->udev, &udev_device->link_list, devlink, NULL, 0) == NULL)
return -ENOMEM;
return 0;
}
int device_add_property(struct udev_device *udev_device, const char *key, const char *value)
{
if (util_name_list_add(udev_device->udev, &udev_device->env_list, key, value, 0) == NULL)
return -ENOMEM;
return 0;
}
int device_add_property_from_string(struct udev_device *udev_device, const char *property)
{
char name[UTIL_PATH_SIZE];
char *val;
strncpy(name, property, sizeof(name));
val = strchr(name, '=');
if (val == NULL)
return -1;
val[0] = '\0';
val = &val[1];
if (val[0] == '\0')
val = NULL;
device_add_property(udev_device, name, val);
return 0;
}
int device_set_action(struct udev_device *udev_device, const char *action)
{
udev_device->action = strdup(action);
if (udev_device->action == NULL)
return -ENOMEM;
return 0;
}
int device_set_driver(struct udev_device *udev_device, const char *driver)
{
udev_device->driver = strdup(driver);
if (udev_device->driver == NULL)
return -ENOMEM;
return 0;
}
const char *device_get_devpath_old(struct udev_device *udev_device)
{
if (udev_device == NULL)
return NULL;
return udev_device->devpath_old;
}
int device_set_devpath_old(struct udev_device *udev_device, const char *devpath_old)
{
udev_device->devpath_old = strdup(devpath_old);
if (udev_device->devpath_old == NULL)
return -ENOMEM;
return 0;
}
const char *device_get_physdevpath(struct udev_device *udev_device)
{
if (udev_device == NULL)
return NULL;
return udev_device->physdevpath;
}
int device_set_physdevpath(struct udev_device *udev_device, const char *physdevpath)
{
udev_device->physdevpath = strdup(physdevpath);
if (udev_device->physdevpath == NULL)
return -ENOMEM;
return 0;
}
int device_get_timeout(struct udev_device *udev_device)
{
if (udev_device == NULL)
return -1;
return udev_device->timeout;
}
int device_set_timeout(struct udev_device *udev_device, int timeout)
{
udev_device->timeout = timeout;
return 0;
}
int device_set_seqnum(struct udev_device *udev_device, unsigned long long int seqnum)
{
udev_device->seqnum = seqnum;
return 0;
}
int device_set_devnum(struct udev_device *udev_device, dev_t devnum)
{
udev_device->devnum = devnum;
return 0;
}
int device_get_num_fake_partitions(struct udev_device *udev_device)
{
if (udev_device == NULL)
return -1;
return udev_device->num_fake_partitions;
}
int device_set_num_fake_partitions(struct udev_device *udev_device, int num)
{
udev_device->num_fake_partitions = num;
return 0;
}
int device_get_devlink_priority(struct udev_device *udev_device)
{
if (udev_device == NULL)
return -1;
return udev_device->devlink_priority;
}
int device_set_devlink_priority(struct udev_device *udev_device, int prio)
{
udev_device->devlink_priority = prio;
return 0;
}
int device_get_ignore_remove(struct udev_device *udev_device)
{
if (udev_device == NULL)
return -1;
return udev_device->ignore_remove;
}
int device_set_ignore_remove(struct udev_device *udev_device, int ignore)
{
udev_device->ignore_remove = ignore;
return 0;
}
|