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
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
|
/*
* Copyright (C) 2004-2008 Kay Sievers <kay.sievers@vrfy.org>
* Copyright (C) 2004 Chris Friesen <chris_friesen@sympatico.ca>
*
* 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 <stddef.h>
#include <signal.h>
#include <unistd.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <fcntl.h>
#include <time.h>
#include <getopt.h>
#include <sys/select.h>
#include <sys/wait.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#ifdef HAVE_INOTIFY
#include <sys/inotify.h>
#endif
#include "udev.h"
#include "udev-rules.h"
#define UDEVD_PRIORITY -4
#define UDEV_PRIORITY -2
/* maximum limit of forked childs */
#define UDEVD_MAX_CHILDS 256
static int debug;
static void log_fn(struct udev *udev, int priority,
const char *file, int line, const char *fn,
const char *format, va_list args)
{
if (debug) {
fprintf(stderr, "[%d] %s: ", (int) getpid(), fn);
vfprintf(stderr, format, args);
} else {
vsyslog(priority, format, args);
}
}
static int debug_trace;
static struct udev_rules rules;
static struct udev_ctrl *udev_ctrl;
static struct udev_monitor *kernel_monitor;
static int inotify_fd = -1;
static int signal_pipe[2] = {-1, -1};
static volatile int sigchilds_waiting;
static volatile int udev_exit;
static volatile int reload_config;
static int run_exec_q;
static int stop_exec_q;
static int max_childs;
static LIST_HEAD(exec_list);
static LIST_HEAD(running_list);
enum event_state {
EVENT_QUEUED,
EVENT_FINISHED,
EVENT_FAILED,
};
static void export_event_state(struct udev_event *event, enum event_state state)
{
char filename[UTIL_PATH_SIZE];
char filename_failed[UTIL_PATH_SIZE];
size_t start;
/* location of queue file */
snprintf(filename, sizeof(filename), "%s/.udev/queue/%llu",
udev_get_dev_path(event->udev), udev_device_get_seqnum(event->dev));
/* location of failed file */
util_strlcpy(filename_failed, udev_get_dev_path(event->udev), sizeof(filename_failed));
util_strlcat(filename_failed, "/", sizeof(filename_failed));
start = util_strlcat(filename_failed, ".udev/failed/", sizeof(filename_failed));
util_strlcat(filename_failed, udev_device_get_devpath(event->dev), sizeof(filename_failed));
util_path_encode(&filename_failed[start], sizeof(filename_failed) - start);
switch (state) {
case EVENT_QUEUED:
unlink(filename_failed);
delete_path(event->udev, filename_failed);
create_path(event->udev, filename);
udev_selinux_setfscreatecon(event->udev, filename, S_IFLNK);
symlink(udev_device_get_devpath(event->dev), filename);
udev_selinux_resetfscreatecon(event->udev);
break;
case EVENT_FINISHED:
if (udev_device_get_devpath_old(event->dev) != NULL) {
/* "move" event - rename failed file to current name, do not delete failed */
char filename_failed_old[UTIL_PATH_SIZE];
util_strlcpy(filename_failed_old, udev_get_dev_path(event->udev), sizeof(filename_failed_old));
util_strlcat(filename_failed_old, "/", sizeof(filename_failed_old));
start = util_strlcat(filename_failed_old, ".udev/failed/", sizeof(filename_failed_old));
util_strlcat(filename_failed_old, udev_device_get_devpath_old(event->dev), sizeof(filename_failed_old));
util_path_encode(&filename_failed_old[start], sizeof(filename) - start);
if (rename(filename_failed_old, filename_failed) == 0)
info(event->udev, "renamed devpath, moved failed state of '%s' to %s'\n",
udev_device_get_devpath_old(event->dev), udev_device_get_devpath(event->dev));
} else {
unlink(filename_failed);
delete_path(event->udev, filename_failed);
}
unlink(filename);
delete_path(event->udev, filename);
break;
case EVENT_FAILED:
/* move failed event to the failed directory */
create_path(event->udev, filename_failed);
rename(filename, filename_failed);
/* clean up possibly empty queue directory */
delete_path(event->udev, filename);
break;
}
return;
}
static void event_queue_delete(struct udev_event *event)
{
list_del(&event->node);
/* mark as failed, if "add" event returns non-zero */
if (event->exitstatus && strcmp(udev_device_get_action(event->dev), "add") == 0)
export_event_state(event, EVENT_FAILED);
else
export_event_state(event, EVENT_FINISHED);
udev_device_unref(event->dev);
udev_event_unref(event);
}
static void asmlinkage event_sig_handler(int signum)
{
if (signum == SIGALRM)
exit(1);
}
static void event_fork(struct udev_event *event)
{
pid_t pid;
struct sigaction act;
int err;
pid = fork();
switch (pid) {
case 0:
/* child */
udev_monitor_unref(kernel_monitor);
udev_ctrl_unref(udev_ctrl);
if (inotify_fd >= 0)
close(inotify_fd);
close(signal_pipe[READ_END]);
close(signal_pipe[WRITE_END]);
logging_close();
logging_init("udevd-event");
setpriority(PRIO_PROCESS, 0, UDEV_PRIORITY);
/* set signal handlers */
memset(&act, 0x00, sizeof(act));
act.sa_handler = (void (*)(int)) event_sig_handler;
sigemptyset (&act.sa_mask);
act.sa_flags = 0;
sigaction(SIGALRM, &act, NULL);
/* reset to default */
act.sa_handler = SIG_DFL;
sigaction(SIGINT, &act, NULL);
sigaction(SIGTERM, &act, NULL);
sigaction(SIGCHLD, &act, NULL);
sigaction(SIGHUP, &act, NULL);
/* set timeout to prevent hanging processes */
alarm(UDEV_EVENT_TIMEOUT);
/* apply rules, create node, symlinks */
err = udev_event_run(event, &rules);
/* rules may change/disable the timeout */
if (udev_device_get_event_timeout(event->dev) >= 0)
alarm(udev_device_get_event_timeout(event->dev));
/* execute RUN= */
if (err == 0 && !event->ignore_device && udev_get_run(event->udev))
udev_rules_run(event);
info(event->udev, "seq %llu exit with %i\n", udev_device_get_seqnum(event->dev), err);
logging_close();
if (err != 0)
exit(1);
exit(0);
case -1:
err(event->udev, "fork of child failed: %m\n");
event_queue_delete(event);
break;
default:
/* get SIGCHLD in main loop */
info(event->udev, "seq %llu forked, pid [%d], '%s' '%s', %ld seconds old\n",
udev_device_get_seqnum(event->dev),
pid,
udev_device_get_action(event->dev),
udev_device_get_subsystem(event->dev),
time(NULL) - event->queue_time);
event->pid = pid;
}
}
static void event_queue_insert(struct udev_event *event)
{
char filename[UTIL_PATH_SIZE];
int fd;
event->queue_time = time(NULL);
export_event_state(event, EVENT_QUEUED);
info(event->udev, "seq %llu queued, '%s' '%s'\n", udev_device_get_seqnum(event->dev),
udev_device_get_action(event->dev), udev_device_get_subsystem(event->dev));
util_strlcpy(filename, udev_get_dev_path(event->udev), sizeof(filename));
util_strlcat(filename, "/.udev/uevent_seqnum", sizeof(filename));
fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0644);
if (fd >= 0) {
char str[32];
int len;
len = sprintf(str, "%llu\n", udev_device_get_seqnum(event->dev));
write(fd, str, len);
close(fd);
}
/* run one event after the other in debug mode */
if (debug_trace) {
list_add_tail(&event->node, &running_list);
event_fork(event);
waitpid(event->pid, NULL, 0);
event_queue_delete(event);
return;
}
/* run all events with a timeout set immediately */
if (udev_device_get_timeout(event->dev) > 0) {
list_add_tail(&event->node, &running_list);
event_fork(event);
return;
}
list_add_tail(&event->node, &exec_list);
run_exec_q = 1;
}
static int mem_size_mb(void)
{
FILE* f;
char buf[4096];
long int memsize = -1;
f = fopen("/proc/meminfo", "r");
if (f == NULL)
return -1;
while (fgets(buf, sizeof(buf), f) != NULL) {
long int value;
if (sscanf(buf, "MemTotal: %ld kB", &value) == 1) {
memsize = value / 1024;
break;
}
}
fclose(f);
return memsize;
}
static int compare_devpath(const char *running, const char *waiting)
{
int i;
for (i = 0; i < UTIL_PATH_SIZE; i++) {
/* identical device event found */
if (running[i] == '\0' && waiting[i] == '\0')
return 1;
/* parent device event found */
if (running[i] == '\0' && waiting[i] == '/')
return 2;
/* child device event found */
if (running[i] == '/' && waiting[i] == '\0')
return 3;
/* no matching event */
if (running[i] != waiting[i])
break;
}
return 0;
}
/* lookup event for identical, parent, child, or physical device */
static int devpath_busy(struct udev_event *event, int limit)
{
struct udev_event *loop_event;
int childs_count = 0;
/* check exec-queue which may still contain delayed events we depend on */
list_for_each_entry(loop_event, &exec_list, node) {
/* skip ourself and all later events */
if (udev_device_get_seqnum(loop_event->dev) >= udev_device_get_seqnum(event->dev))
break;
/* check our old name */
if (udev_device_get_devpath_old(event->dev) != NULL)
if (strcmp(udev_device_get_devpath(loop_event->dev), udev_device_get_devpath_old(event->dev)) == 0)
return 2;
/* check identical, parent, or child device event */
if (compare_devpath(udev_device_get_devpath(loop_event->dev), udev_device_get_devpath(event->dev)) != 0) {
dbg(event->udev, "%llu, device event still pending %llu (%s)\n",
udev_device_get_seqnum(event->dev),
udev_device_get_seqnum(loop_event->dev),
udev_device_get_devpath(loop_event->dev));
return 3;
}
/* check for our major:minor number */
if (major(udev_device_get_devnum(event->dev)) > 0 &&
udev_device_get_devnum(loop_event->dev) == udev_device_get_devnum(event->dev) &&
strcmp(udev_device_get_subsystem(event->dev), udev_device_get_subsystem(loop_event->dev)) == 0) {
dbg(event->udev, "%llu, device event still pending %llu (%d:%d)\n",
udev_device_get_seqnum(event->dev),
udev_device_get_seqnum(loop_event->dev),
major(udev_device_get_devnum(loop_event->dev)), minor(udev_device_get_devnum(loop_event->dev)));
return 4;
}
/* check physical device event (special case of parent) */
if (udev_device_get_physdevpath(event->dev) != NULL &&
strcmp(udev_device_get_action(event->dev), "add") == 0)
if (compare_devpath(udev_device_get_devpath(loop_event->dev),
udev_device_get_physdevpath(event->dev)) != 0) {
dbg(event->udev, "%llu, physical device event still pending %llu (%s)\n",
udev_device_get_seqnum(event->dev),
udev_device_get_seqnum(loop_event->dev),
udev_device_get_devpath(loop_event->dev));
return 5;
}
}
/* check run queue for still running events */
list_for_each_entry(loop_event, &running_list, node) {
childs_count++;
if (childs_count++ >= limit) {
info(event->udev, "%llu, maximum number (%i) of childs reached\n",
udev_device_get_seqnum(event->dev), childs_count);
return 1;
}
/* check our old name */
if (udev_device_get_devpath_old(event->dev) != NULL)
if (strcmp(udev_device_get_devpath(loop_event->dev), udev_device_get_devpath_old(event->dev)) == 0)
return 2;
/* check identical, parent, or child device event */
if (compare_devpath(udev_device_get_devpath(loop_event->dev), udev_device_get_devpath(event->dev)) != 0) {
dbg(event->udev, "%llu, device event still running %llu (%s)\n",
udev_device_get_seqnum(event->dev),
udev_device_get_seqnum(loop_event->dev),
udev_device_get_devpath(loop_event->dev));
return 3;
}
/* check for our major:minor number */
if (major(udev_device_get_devnum(event->dev)) > 0 &&
udev_device_get_devnum(loop_event->dev) == udev_device_get_devnum(event->dev) &&
strcmp(udev_device_get_subsystem(event->dev), udev_device_get_subsystem(loop_event->dev)) == 0) {
dbg(event->udev, "%llu, device event still pending %llu (%d:%d)\n",
udev_device_get_seqnum(event->dev),
udev_device_get_seqnum(loop_event->dev),
major(udev_device_get_devnum(loop_event->dev)), minor(udev_device_get_devnum(loop_event->dev)));
return 4;
}
/* check physical device event (special case of parent) */
if (udev_device_get_physdevpath(event->dev) != NULL &&
strcmp(udev_device_get_action(event->dev), "add") == 0)
if (compare_devpath(udev_device_get_devpath(loop_event->dev),
udev_device_get_physdevpath(event->dev)) != 0) {
dbg(event->udev, "%llu, physical device event still pending %llu (%s)\n",
udev_device_get_seqnum(event->dev),
udev_device_get_seqnum(loop_event->dev),
udev_device_get_devpath(loop_event->dev));
return 5;
}
}
return 0;
}
/* serializes events for the identical and parent and child devices */
static void event_queue_manager(struct udev *udev)
{
struct udev_event *loop_event;
struct udev_event *tmp_event;
if (list_empty(&exec_list))
return;
list_for_each_entry_safe(loop_event, tmp_event, &exec_list, node) {
/* serialize and wait for parent or child events */
if (devpath_busy(loop_event, max_childs) != 0) {
dbg(udev, "delay seq %llu (%s)\n",
udev_device_get_seqnum(loop_event->dev),
udev_device_get_devpath(loop_event->dev));
continue;
}
/* move event to run list */
list_move_tail(&loop_event->node, &running_list);
event_fork(loop_event);
dbg(udev, "moved seq %llu to running list\n", udev_device_get_seqnum(loop_event->dev));
}
}
/* receive the udevd message from userspace */
static void handle_ctrl_msg(struct udev_ctrl *uctrl)
{
struct udev *udev = udev_ctrl_get_udev(uctrl);
struct udev_ctrl_msg *ctrl_msg;
const char *str;
int i;
ctrl_msg = udev_ctrl_receive_msg(uctrl);
if (ctrl_msg == NULL)
return;
i = udev_ctrl_get_set_log_level(ctrl_msg);
if (i >= 0) {
info(udev, "udevd message (SET_LOG_PRIORITY) received, log_priority=%i\n", i);
udev_set_log_priority(udev, i);
}
if (udev_ctrl_get_stop_exec_queue(ctrl_msg) > 0) {
info(udev, "udevd message (STOP_EXEC_QUEUE) received\n");
stop_exec_q = 1;
}
if (udev_ctrl_get_start_exec_queue(ctrl_msg) > 0) {
info(udev, "udevd message (START_EXEC_QUEUE) received\n");
stop_exec_q = 0;
event_queue_manager(udev);
}
if (udev_ctrl_get_reload_rules(ctrl_msg) > 0) {
info(udev, "udevd message (RELOAD_RULES) received\n");
reload_config = 1;
}
str = udev_ctrl_get_set_env(ctrl_msg);
if (str != NULL) {
char *key;
key = strdup(str);
if (key != NULL) {
char *val;
val = strchr(key, '=');
if (val != NULL) {
val[0] = '\0';
val = &val[1];
if (val[0] == '\0') {
info(udev, "udevd message (ENV) received, unset '%s'\n", key);
udev_add_property(udev, key, NULL);
} else {
info(udev, "udevd message (ENV) received, set '%s=%s'\n", key, val);
udev_add_property(udev, key, val);
}
} else {
err(udev, "wrong key format '%s'\n", key);
}
free(key);
}
}
i = udev_ctrl_get_set_max_childs(ctrl_msg);
if (i >= 0) {
info(udev, "udevd message (SET_MAX_CHILDS) received, max_childs=%i\n", i);
max_childs = i;
}
udev_ctrl_msg_unref(ctrl_msg);
}
static void asmlinkage sig_handler(int signum)
{
switch (signum) {
case SIGINT:
case SIGTERM:
udev_exit = 1;
break;
case SIGCHLD:
/* set flag, then write to pipe if needed */
sigchilds_waiting = 1;
break;
case SIGHUP:
reload_config = 1;
break;
}
/* write to pipe, which will wakeup select() in our mainloop */
write(signal_pipe[WRITE_END], "", 1);
}
static void udev_done(int pid, int exitstatus)
{
/* find event associated with pid and delete it */
struct udev_event *event;
list_for_each_entry(event, &running_list, node) {
if (event->pid == pid) {
info(event->udev, "seq %llu cleanup, pid [%d], status %i, %ld seconds old\n",
udev_device_get_seqnum(event->dev), event->pid,
exitstatus, time(NULL) - event->queue_time);
event->exitstatus = exitstatus;
event_queue_delete(event);
/* there may be events waiting with the same devpath */
run_exec_q = 1;
return;
}
}
}
static void reap_sigchilds(void)
{
pid_t pid;
int status;
while (1) {
pid = waitpid(-1, &status, WNOHANG);
if (pid <= 0)
break;
if (WIFEXITED(status))
status = WEXITSTATUS(status);
else if (WIFSIGNALED(status))
status = WTERMSIG(status) + 128;
else
status = 0;
udev_done(pid, status);
}
}
static void export_initial_seqnum(struct udev *udev)
{
char filename[UTIL_PATH_SIZE];
int fd;
char seqnum[32];
ssize_t len = 0;
util_strlcpy(filename, udev_get_sys_path(udev), sizeof(filename));
util_strlcat(filename, "/kernel/uevent_seqnum", sizeof(filename));
fd = open(filename, O_RDONLY);
if (fd >= 0) {
len = read(fd, seqnum, sizeof(seqnum)-1);
close(fd);
}
if (len <= 0) {
strcpy(seqnum, "0\n");
len = 3;
}
util_strlcpy(filename, udev_get_dev_path(udev), sizeof(filename));
util_strlcat(filename, "/.udev/uevent_seqnum", sizeof(filename));
create_path(udev, filename);
fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0644);
if (fd >= 0) {
write(fd, seqnum, len);
close(fd);
}
}
int main(int argc, char *argv[])
{
struct udev *udev;
int err;
int fd;
struct sigaction act;
fd_set readfds;
const char *value;
int daemonize = 0;
static const struct option options[] = {
{ "daemon", no_argument, NULL, 'd' },
{ "debug-trace", no_argument, NULL, 't' },
{ "debug", no_argument, NULL, 'D' },
{ "help", no_argument, NULL, 'h' },
{ "version", no_argument, NULL, 'V' },
{}
};
int rc = 1;
int maxfd;
udev = udev_new();
if (udev == NULL)
goto exit;
logging_init("udevd");
udev_set_log_fn(udev, log_fn);
info(udev, "version %s\n", VERSION);
selinux_init(udev);
while (1) {
int option;
option = getopt_long(argc, argv, "dDthV", options, NULL);
if (option == -1)
break;
switch (option) {
case 'd':
daemonize = 1;
break;
case 't':
debug_trace = 1;
break;
case 'D':
debug = 1;
if (udev_get_log_priority(udev) < LOG_INFO)
udev_set_log_priority(udev, LOG_INFO);
break;
case 'h':
printf("Usage: udevd [--help] [--daemon] [--debug-trace] [--debug] [--version]\n");
goto exit;
case 'V':
printf("%s\n", VERSION);
goto exit;
default:
goto exit;
}
}
if (getuid() != 0) {
fprintf(stderr, "root privileges required\n");
err(udev, "root privileges required\n");
goto exit;
}
/* make sure std{in,out,err} fd's are in a sane state */
fd = open("/dev/null", O_RDWR);
if (fd < 0) {
fprintf(stderr, "cannot open /dev/null\n");
err(udev, "cannot open /dev/null\n");
}
if (fd > STDIN_FILENO)
dup2(fd, STDIN_FILENO);
if (write(STDOUT_FILENO, 0, 0) < 0)
dup2(fd, STDOUT_FILENO);
if (write(STDERR_FILENO, 0, 0) < 0)
dup2(fd, STDERR_FILENO);
/* init control socket, bind() ensures, that only one udevd instance is running */
udev_ctrl = udev_ctrl_new_from_socket(udev, UDEV_CTRL_SOCK_PATH);
if (udev_ctrl == NULL) {
fprintf(stderr, "error initializing control socket");
err(udev, "error initializing udevd socket");
rc = 1;
goto exit;
}
if (udev_ctrl_enable_receiving(udev_ctrl) < 0) {
fprintf(stderr, "error binding control socket, seems udevd is already running\n");
err(udev, "error binding control socket, seems udevd is already running\n");
rc = 1;
goto exit;
}
kernel_monitor = udev_monitor_new_from_netlink(udev);
if (kernel_monitor == NULL || udev_monitor_enable_receiving(kernel_monitor) < 0) {
fprintf(stderr, "error initializing netlink socket\n");
err(udev, "error initializing netlink socket\n");
rc = 3;
goto exit;
}
udev_monitor_set_receive_buffer_size(kernel_monitor, 128*1024*1024);
err = pipe(signal_pipe);
if (err < 0) {
err(udev, "error getting pipes: %m\n");
goto exit;
}
err = fcntl(signal_pipe[READ_END], F_GETFL, 0);
if (err < 0) {
err(udev, "error fcntl on read pipe: %m\n");
goto exit;
}
err = fcntl(signal_pipe[READ_END], F_SETFL, err | O_NONBLOCK);
if (err < 0) {
err(udev, "error fcntl on read pipe: %m\n");
goto exit;
}
err = fcntl(signal_pipe[WRITE_END], F_GETFL, 0);
if (err < 0) {
err(udev, "error fcntl on write pipe: %m\n");
goto exit;
}
err = fcntl(signal_pipe[WRITE_END], F_SETFL, err | O_NONBLOCK);
if (err < 0) {
err(udev, "error fcntl on write pipe: %m\n");
goto exit;
}
udev_rules_init(udev, &rules, 1);
export_initial_seqnum(udev);
if (daemonize) {
pid_t pid;
pid = fork();
switch (pid) {
case 0:
dbg(udev, "daemonized fork running\n");
break;
case -1:
err(udev, "fork of daemon failed: %m\n");
rc = 4;
goto exit;
default:
dbg(udev, "child [%u] running, parent exits\n", pid);
rc = 0;
goto exit;
}
}
/* redirect std{out,err} */
if (!debug) {
dup2(fd, STDOUT_FILENO);
dup2(fd, STDERR_FILENO);
}
if (fd > STDERR_FILENO)
close(fd);
/* set scheduling priority for the daemon */
setpriority(PRIO_PROCESS, 0, UDEVD_PRIORITY);
chdir("/");
umask(022);
setsid();
/* OOM_DISABLE == -17 */
fd = open("/proc/self/oom_adj", O_RDWR);
if (fd < 0)
err(udev, "error disabling OOM: %m\n");
else {
write(fd, "-17", 3);
close(fd);
}
fd = open("/dev/kmsg", O_WRONLY);
if (fd > 0) {
const char *ver_str = "<6>udev: starting version " VERSION "\n";
char path[UTIL_PATH_SIZE];
struct stat statbuf;
write(fd, ver_str, strlen(ver_str));
util_strlcpy(path, udev_get_sys_path(udev), sizeof(path));
util_strlcat(path, "/class/mem/null", sizeof(path));
if (lstat(path, &statbuf) == 0) {
if (S_ISDIR(statbuf.st_mode)) {
const char *depr_str = "<6>udev: deprecated sysfs layout (kernel too old, "
"or CONFIG_SYSFS_DEPRECATED) is unsupported, some "
"udev features may fail\n";
write(fd, depr_str, strlen(depr_str));
}
}
close(fd);
}
/* set signal handlers */
memset(&act, 0x00, sizeof(struct sigaction));
act.sa_handler = (void (*)(int)) sig_handler;
sigemptyset(&act.sa_mask);
act.sa_flags = SA_RESTART;
sigaction(SIGINT, &act, NULL);
sigaction(SIGTERM, &act, NULL);
sigaction(SIGCHLD, &act, NULL);
sigaction(SIGHUP, &act, NULL);
/* watch rules directory */
inotify_fd = inotify_init();
if (inotify_fd >= 0) {
if (udev_get_rules_path(udev) != NULL) {
inotify_add_watch(inotify_fd, udev_get_rules_path(udev),
IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
} else {
char filename[PATH_MAX];
inotify_add_watch(inotify_fd, UDEV_PREFIX "/lib/udev/rules.d",
IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
inotify_add_watch(inotify_fd, SYSCONFDIR "/udev/rules.d",
IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
/* watch dynamic rules directory */
util_strlcpy(filename, udev_get_dev_path(udev), sizeof(filename));
util_strlcat(filename, "/.udev/rules.d", sizeof(filename));
inotify_add_watch(inotify_fd, filename,
IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
}
} else if (errno == ENOSYS)
err(udev, "the kernel does not support inotify, udevd can't monitor rules file changes\n");
else
err(udev, "inotify_init failed: %m\n");
/* maximum limit of forked childs */
value = getenv("UDEVD_MAX_CHILDS");
if (value)
max_childs = strtoul(value, NULL, 10);
else {
int memsize = mem_size_mb();
if (memsize > 0)
max_childs = 128 + (memsize / 4);
else
max_childs = UDEVD_MAX_CHILDS;
}
info(udev, "initialize max_childs to %u\n", max_childs);
maxfd = udev_ctrl_get_fd(udev_ctrl);
maxfd = UDEV_MAX(maxfd, udev_monitor_get_fd(kernel_monitor));
maxfd = UDEV_MAX(maxfd, signal_pipe[READ_END]);
maxfd = UDEV_MAX(maxfd, inotify_fd);
while (!udev_exit) {
int fdcount;
FD_ZERO(&readfds);
FD_SET(signal_pipe[READ_END], &readfds);
FD_SET(udev_ctrl_get_fd(udev_ctrl), &readfds);
FD_SET(udev_monitor_get_fd(kernel_monitor), &readfds);
if (inotify_fd >= 0)
FD_SET(inotify_fd, &readfds);
fdcount = select(maxfd+1, &readfds, NULL, NULL, NULL);
if (fdcount < 0) {
if (errno != EINTR)
err(udev, "error in select: %m\n");
continue;
}
/* get control message */
if (FD_ISSET(udev_ctrl_get_fd(udev_ctrl), &readfds))
handle_ctrl_msg(udev_ctrl);
/* get kernel uevent */
if (FD_ISSET(udev_monitor_get_fd(kernel_monitor), &readfds)) {
struct udev_device *dev;
dev = udev_monitor_receive_device(kernel_monitor);
if (dev != NULL) {
struct udev_event *event;
event = udev_event_new(dev);
if (event != NULL)
event_queue_insert(event);
else
udev_device_unref(dev);
}
}
/* received a signal, clear our notification pipe */
if (FD_ISSET(signal_pipe[READ_END], &readfds)) {
char buf[256];
read(signal_pipe[READ_END], &buf, sizeof(buf));
}
/* rules directory inotify watch */
if ((inotify_fd >= 0) && FD_ISSET(inotify_fd, &readfds)) {
int nbytes;
/* discard all possible events, we can just reload the config */
if ((ioctl(inotify_fd, FIONREAD, &nbytes) == 0) && nbytes > 0) {
char *buf;
reload_config = 1;
buf = malloc(nbytes);
if (buf == NULL) {
err(udev, "error getting buffer for inotify, disable watching\n");
close(inotify_fd);
inotify_fd = -1;
}
read(inotify_fd, buf, nbytes);
free(buf);
}
}
/* rules changed, set by inotify or a HUP signal */
if (reload_config) {
reload_config = 0;
udev_rules_cleanup(&rules);
udev_rules_init(udev, &rules, 1);
}
if (sigchilds_waiting) {
sigchilds_waiting = 0;
reap_sigchilds();
}
if (run_exec_q) {
run_exec_q = 0;
if (!stop_exec_q)
event_queue_manager(udev);
}
}
rc = 0;
exit:
udev_rules_cleanup(&rules);
if (signal_pipe[READ_END] >= 0)
close(signal_pipe[READ_END]);
if (signal_pipe[WRITE_END] >= 0)
close(signal_pipe[WRITE_END]);
udev_ctrl_unref(udev_ctrl);
if (inotify_fd >= 0)
close(inotify_fd);
udev_monitor_unref(kernel_monitor);
selinux_exit(udev);
udev_unref(udev);
logging_close();
return rc;
}
|