]>
Commit | Line | Data |
---|---|---|
88a6477e KS |
1 | /*** |
2 | This file is part of systemd. | |
3 | ||
4 | Copyright 2008-2012 Kay Sievers <kay@vrfy.org> | |
5 | Copyright 2009 Alan Jenkins <alan-jenkins@tuffmail.co.uk> | |
6 | ||
7 | systemd is free software; you can redistribute it and/or modify it | |
8 | under the terms of the GNU Lesser General Public License as published by | |
9 | the Free Software Foundation; either version 2.1 of the License, or | |
10 | (at your option) any later version. | |
11 | ||
12 | systemd is distributed in the hope that it will be useful, but | |
13 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
15 | Lesser General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU Lesser General Public License | |
18 | along with systemd; If not, see <http://www.gnu.org/licenses/>. | |
19 | ***/ | |
64ccdf82 KS |
20 | |
21 | #include <stdio.h> | |
22 | #include <stdlib.h> | |
23 | #include <stddef.h> | |
24 | #include <unistd.h> | |
25 | #include <errno.h> | |
26 | #include <string.h> | |
27 | #include <dirent.h> | |
28 | #include <fcntl.h> | |
f503f6b2 | 29 | #include <limits.h> |
64ccdf82 KS |
30 | #include <sys/stat.h> |
31 | ||
32 | #include "libudev.h" | |
33 | #include "libudev-private.h" | |
34 | ||
ce1d6d7f KS |
35 | /** |
36 | * SECTION:libudev-queue | |
37 | * @short_description: access to currently active events | |
38 | * | |
a7d29d15 KS |
39 | * The udev daemon processes events asynchronously. All events which do not have |
40 | * interdependencies run in parallel. This exports the current state of the | |
41 | * event processing queue, and the current event sequence numbers from the kernel | |
ce1d6d7f KS |
42 | * and the udev daemon. |
43 | */ | |
44 | ||
45 | /** | |
46 | * udev_queue: | |
47 | * | |
48 | * Opaque object representing the current event queue in the udev daemon. | |
49 | */ | |
64ccdf82 | 50 | struct udev_queue { |
912541b0 KS |
51 | struct udev *udev; |
52 | int refcount; | |
53 | struct udev_list queue_list; | |
64ccdf82 KS |
54 | }; |
55 | ||
8d6bc73a KS |
56 | /** |
57 | * udev_queue_new: | |
58 | * @udev: udev library context | |
59 | * | |
60 | * The initial refcount is 1, and needs to be decremented to | |
61 | * release the resources of the udev queue context. | |
62 | * | |
63 | * Returns: the udev queue context, or #NULL on error. | |
64 | **/ | |
54cf0b7f | 65 | _public_ struct udev_queue *udev_queue_new(struct udev *udev) |
64ccdf82 | 66 | { |
912541b0 KS |
67 | struct udev_queue *udev_queue; |
68 | ||
69 | if (udev == NULL) | |
70 | return NULL; | |
71 | ||
72 | udev_queue = calloc(1, sizeof(struct udev_queue)); | |
73 | if (udev_queue == NULL) | |
74 | return NULL; | |
75 | udev_queue->refcount = 1; | |
76 | udev_queue->udev = udev; | |
77 | udev_list_init(udev, &udev_queue->queue_list, false); | |
78 | return udev_queue; | |
64ccdf82 KS |
79 | } |
80 | ||
8d6bc73a KS |
81 | /** |
82 | * udev_queue_ref: | |
83 | * @udev_queue: udev queue context | |
84 | * | |
85 | * Take a reference of a udev queue context. | |
86 | * | |
87 | * Returns: the same udev queue context. | |
88 | **/ | |
54cf0b7f | 89 | _public_ struct udev_queue *udev_queue_ref(struct udev_queue *udev_queue) |
64ccdf82 | 90 | { |
912541b0 KS |
91 | if (udev_queue == NULL) |
92 | return NULL; | |
93 | udev_queue->refcount++; | |
94 | return udev_queue; | |
64ccdf82 KS |
95 | } |
96 | ||
8d6bc73a KS |
97 | /** |
98 | * udev_queue_unref: | |
99 | * @udev_queue: udev queue context | |
100 | * | |
101 | * Drop a reference of a udev queue context. If the refcount reaches zero, | |
102 | * the resources of the queue context will be released. | |
c1959569 KS |
103 | * |
104 | * Returns: the passed queue context if it has still an active reference, or #NULL otherwise. | |
8d6bc73a | 105 | **/ |
20bbd54f | 106 | _public_ struct udev_queue *udev_queue_unref(struct udev_queue *udev_queue) |
64ccdf82 | 107 | { |
912541b0 | 108 | if (udev_queue == NULL) |
20bbd54f | 109 | return NULL; |
912541b0 KS |
110 | udev_queue->refcount--; |
111 | if (udev_queue->refcount > 0) | |
20bbd54f | 112 | return udev_queue; |
912541b0 KS |
113 | udev_list_cleanup(&udev_queue->queue_list); |
114 | free(udev_queue); | |
20bbd54f | 115 | return NULL; |
64ccdf82 KS |
116 | } |
117 | ||
8d6bc73a KS |
118 | /** |
119 | * udev_queue_get_udev: | |
120 | * @udev_queue: udev queue context | |
121 | * | |
122 | * Retrieve the udev library context the queue context was created with. | |
123 | * | |
124 | * Returns: the udev library context. | |
125 | **/ | |
54cf0b7f | 126 | _public_ struct udev *udev_queue_get_udev(struct udev_queue *udev_queue) |
64ccdf82 | 127 | { |
912541b0 KS |
128 | if (udev_queue == NULL) |
129 | return NULL; | |
130 | return udev_queue->udev; | |
64ccdf82 KS |
131 | } |
132 | ||
f503f6b2 | 133 | unsigned long long int udev_get_kernel_seqnum(struct udev *udev) |
64ccdf82 | 134 | { |
912541b0 KS |
135 | unsigned long long int seqnum; |
136 | int fd; | |
137 | char buf[32]; | |
138 | ssize_t len; | |
139 | ||
6ada823a | 140 | fd = open("/sys/kernel/uevent_seqnum", O_RDONLY|O_CLOEXEC); |
912541b0 KS |
141 | if (fd < 0) |
142 | return 0; | |
143 | len = read(fd, buf, sizeof(buf)); | |
144 | close(fd); | |
145 | if (len <= 2) | |
146 | return 0; | |
147 | buf[len-1] = '\0'; | |
148 | seqnum = strtoull(buf, NULL, 10); | |
149 | return seqnum; | |
64ccdf82 KS |
150 | } |
151 | ||
8d6bc73a KS |
152 | /** |
153 | * udev_queue_get_kernel_seqnum: | |
154 | * @udev_queue: udev queue context | |
155 | * | |
21dbe43a KS |
156 | * Get the current kernel event sequence number. |
157 | * | |
158 | * Returns: the sequence number. | |
8d6bc73a | 159 | **/ |
54cf0b7f | 160 | _public_ unsigned long long int udev_queue_get_kernel_seqnum(struct udev_queue *udev_queue) |
64ccdf82 | 161 | { |
912541b0 | 162 | unsigned long long int seqnum; |
64ccdf82 | 163 | |
912541b0 KS |
164 | if (udev_queue == NULL) |
165 | return -EINVAL; | |
f503f6b2 | 166 | |
912541b0 | 167 | seqnum = udev_get_kernel_seqnum(udev_queue->udev); |
912541b0 | 168 | return seqnum; |
64ccdf82 KS |
169 | } |
170 | ||
f503f6b2 AJ |
171 | int udev_queue_read_seqnum(FILE *queue_file, unsigned long long int *seqnum) |
172 | { | |
912541b0 KS |
173 | if (fread(seqnum, sizeof(unsigned long long int), 1, queue_file) != 1) |
174 | return -1; | |
f503f6b2 | 175 | |
912541b0 | 176 | return 0; |
f503f6b2 AJ |
177 | } |
178 | ||
179 | ssize_t udev_queue_skip_devpath(FILE *queue_file) | |
180 | { | |
912541b0 | 181 | unsigned short int len; |
f503f6b2 | 182 | |
912541b0 | 183 | if (fread(&len, sizeof(unsigned short int), 1, queue_file) == 1) { |
fc863dea | 184 | char *devpath = alloca(len); |
f503f6b2 | 185 | |
912541b0 KS |
186 | /* use fread to skip, fseek might drop buffered data */ |
187 | if (fread(devpath, 1, len, queue_file) == len) | |
188 | return len; | |
189 | } | |
f503f6b2 | 190 | |
912541b0 | 191 | return -1; |
f503f6b2 AJ |
192 | } |
193 | ||
194 | ssize_t udev_queue_read_devpath(FILE *queue_file, char *devpath, size_t size) | |
195 | { | |
912541b0 KS |
196 | unsigned short int read_bytes = 0; |
197 | unsigned short int len; | |
f503f6b2 | 198 | |
912541b0 KS |
199 | if (fread(&len, sizeof(unsigned short int), 1, queue_file) != 1) |
200 | return -1; | |
f503f6b2 | 201 | |
912541b0 KS |
202 | read_bytes = (len < size - 1) ? len : size - 1; |
203 | if (fread(devpath, 1, read_bytes, queue_file) != read_bytes) | |
204 | return -1; | |
205 | devpath[read_bytes] = '\0'; | |
f503f6b2 | 206 | |
912541b0 KS |
207 | /* if devpath was too long, skip unread characters */ |
208 | if (read_bytes != len) { | |
209 | unsigned short int skip_bytes = len - read_bytes; | |
fc863dea | 210 | char *buf = alloca(skip_bytes); |
f503f6b2 | 211 | |
912541b0 KS |
212 | if (fread(buf, 1, skip_bytes, queue_file) != skip_bytes) |
213 | return -1; | |
214 | } | |
f503f6b2 | 215 | |
912541b0 | 216 | return read_bytes; |
f503f6b2 AJ |
217 | } |
218 | ||
219 | static FILE *open_queue_file(struct udev_queue *udev_queue, unsigned long long int *seqnum_start) | |
11d5eec2 | 220 | { |
912541b0 | 221 | FILE *queue_file; |
11d5eec2 | 222 | |
a267bebf | 223 | queue_file = fopen("/run/udev/queue.bin", "re"); |
912541b0 KS |
224 | if (queue_file == NULL) |
225 | return NULL; | |
f503f6b2 | 226 | |
912541b0 | 227 | if (udev_queue_read_seqnum(queue_file, seqnum_start) < 0) { |
c8f8394a | 228 | udev_err(udev_queue->udev, "corrupt queue file\n"); |
912541b0 KS |
229 | fclose(queue_file); |
230 | return NULL; | |
231 | } | |
f503f6b2 | 232 | |
912541b0 | 233 | return queue_file; |
f503f6b2 AJ |
234 | } |
235 | ||
8d6bc73a KS |
236 | /** |
237 | * udev_queue_get_udev_seqnum: | |
238 | * @udev_queue: udev queue context | |
239 | * | |
21dbe43a KS |
240 | * Get the last known udev event sequence number. |
241 | * | |
242 | * Returns: the sequence number. | |
8d6bc73a | 243 | **/ |
54cf0b7f | 244 | _public_ unsigned long long int udev_queue_get_udev_seqnum(struct udev_queue *udev_queue) |
f503f6b2 | 245 | { |
912541b0 KS |
246 | unsigned long long int seqnum_udev; |
247 | FILE *queue_file; | |
248 | ||
249 | queue_file = open_queue_file(udev_queue, &seqnum_udev); | |
250 | if (queue_file == NULL) | |
251 | return 0; | |
252 | ||
253 | for (;;) { | |
254 | unsigned long long int seqnum; | |
255 | ssize_t devpath_len; | |
256 | ||
257 | if (udev_queue_read_seqnum(queue_file, &seqnum) < 0) | |
258 | break; | |
259 | devpath_len = udev_queue_skip_devpath(queue_file); | |
260 | if (devpath_len < 0) | |
261 | break; | |
262 | if (devpath_len > 0) | |
263 | seqnum_udev = seqnum; | |
264 | } | |
265 | ||
266 | fclose(queue_file); | |
267 | return seqnum_udev; | |
f503f6b2 AJ |
268 | } |
269 | ||
8d6bc73a KS |
270 | /** |
271 | * udev_queue_get_udev_is_active: | |
272 | * @udev_queue: udev queue context | |
273 | * | |
21dbe43a KS |
274 | * Check if udev is active on the system. |
275 | * | |
8d6bc73a KS |
276 | * Returns: a flag indicating if udev is active. |
277 | **/ | |
54cf0b7f | 278 | _public_ int udev_queue_get_udev_is_active(struct udev_queue *udev_queue) |
f503f6b2 | 279 | { |
912541b0 KS |
280 | unsigned long long int seqnum_start; |
281 | FILE *queue_file; | |
f503f6b2 | 282 | |
912541b0 KS |
283 | queue_file = open_queue_file(udev_queue, &seqnum_start); |
284 | if (queue_file == NULL) | |
285 | return 0; | |
f503f6b2 | 286 | |
912541b0 KS |
287 | fclose(queue_file); |
288 | return 1; | |
11d5eec2 KS |
289 | } |
290 | ||
8d6bc73a KS |
291 | /** |
292 | * udev_queue_get_queue_is_empty: | |
293 | * @udev_queue: udev queue context | |
294 | * | |
21dbe43a KS |
295 | * Check if udev is currently processing any events. |
296 | * | |
8d6bc73a KS |
297 | * Returns: a flag indicating if udev is currently handling events. |
298 | **/ | |
54cf0b7f | 299 | _public_ int udev_queue_get_queue_is_empty(struct udev_queue *udev_queue) |
64ccdf82 | 300 | { |
912541b0 KS |
301 | unsigned long long int seqnum_kernel; |
302 | unsigned long long int seqnum_udev = 0; | |
303 | int queued = 0; | |
304 | int is_empty = 0; | |
305 | FILE *queue_file; | |
306 | ||
307 | if (udev_queue == NULL) | |
308 | return -EINVAL; | |
309 | queue_file = open_queue_file(udev_queue, &seqnum_udev); | |
310 | if (queue_file == NULL) | |
311 | return 1; | |
312 | ||
313 | for (;;) { | |
314 | unsigned long long int seqnum; | |
315 | ssize_t devpath_len; | |
316 | ||
317 | if (udev_queue_read_seqnum(queue_file, &seqnum) < 0) | |
318 | break; | |
319 | devpath_len = udev_queue_skip_devpath(queue_file); | |
320 | if (devpath_len < 0) | |
321 | break; | |
322 | ||
323 | if (devpath_len > 0) { | |
324 | queued++; | |
325 | seqnum_udev = seqnum; | |
326 | } else { | |
327 | queued--; | |
328 | } | |
329 | } | |
330 | ||
baa30fbc | 331 | if (queued > 0) |
912541b0 | 332 | goto out; |
912541b0 KS |
333 | |
334 | seqnum_kernel = udev_queue_get_kernel_seqnum(udev_queue); | |
baa30fbc | 335 | if (seqnum_udev < seqnum_kernel) |
912541b0 | 336 | goto out; |
912541b0 | 337 | |
912541b0 | 338 | is_empty = 1; |
f503f6b2 AJ |
339 | |
340 | out: | |
912541b0 KS |
341 | fclose(queue_file); |
342 | return is_empty; | |
64ccdf82 KS |
343 | } |
344 | ||
8d6bc73a KS |
345 | /** |
346 | * udev_queue_get_seqnum_sequence_is_finished: | |
347 | * @udev_queue: udev queue context | |
348 | * @start: first event sequence number | |
349 | * @end: last event sequence number | |
350 | * | |
21dbe43a KS |
351 | * Check if udev is currently processing any events in a given sequence number range. |
352 | * | |
2906cbba | 353 | * Returns: a flag indicating if any of the sequence numbers in the given range is currently active. |
8d6bc73a | 354 | **/ |
54cf0b7f | 355 | _public_ int udev_queue_get_seqnum_sequence_is_finished(struct udev_queue *udev_queue, |
912541b0 | 356 | unsigned long long int start, unsigned long long int end) |
64ccdf82 | 357 | { |
912541b0 KS |
358 | unsigned long long int seqnum; |
359 | ssize_t devpath_len; | |
360 | int unfinished; | |
361 | FILE *queue_file; | |
362 | ||
363 | if (udev_queue == NULL) | |
364 | return -EINVAL; | |
365 | queue_file = open_queue_file(udev_queue, &seqnum); | |
366 | if (queue_file == NULL) | |
367 | return 1; | |
368 | if (start < seqnum) | |
369 | start = seqnum; | |
370 | if (start > end) { | |
371 | fclose(queue_file); | |
372 | return 1; | |
373 | } | |
374 | if (end - start > INT_MAX - 1) { | |
375 | fclose(queue_file); | |
376 | return -EOVERFLOW; | |
377 | } | |
378 | ||
379 | /* | |
380 | * we might start with 0, and handle the initial seqnum | |
381 | * only when we find an entry in the queue file | |
382 | **/ | |
383 | unfinished = end - start; | |
384 | ||
385 | do { | |
386 | if (udev_queue_read_seqnum(queue_file, &seqnum) < 0) | |
387 | break; | |
388 | devpath_len = udev_queue_skip_devpath(queue_file); | |
389 | if (devpath_len < 0) | |
390 | break; | |
391 | ||
392 | /* | |
393 | * we might start with an empty or re-build queue file, where | |
394 | * the initial seqnum is not recorded as finished | |
395 | */ | |
396 | if (start == seqnum && devpath_len > 0) | |
397 | unfinished++; | |
398 | ||
399 | if (devpath_len == 0) { | |
400 | if (seqnum >= start && seqnum <= end) | |
401 | unfinished--; | |
402 | } | |
403 | } while (unfinished > 0); | |
404 | ||
405 | fclose(queue_file); | |
406 | ||
407 | return (unfinished == 0); | |
f503f6b2 AJ |
408 | } |
409 | ||
8d6bc73a KS |
410 | /** |
411 | * udev_queue_get_seqnum_is_finished: | |
412 | * @udev_queue: udev queue context | |
413 | * @seqnum: sequence number | |
414 | * | |
21dbe43a KS |
415 | * Check if udev is currently processing a given sequence number. |
416 | * | |
2906cbba | 417 | * Returns: a flag indicating if the given sequence number is currently active. |
8d6bc73a | 418 | **/ |
54cf0b7f | 419 | _public_ int udev_queue_get_seqnum_is_finished(struct udev_queue *udev_queue, unsigned long long int seqnum) |
f503f6b2 | 420 | { |
912541b0 KS |
421 | if (!udev_queue_get_seqnum_sequence_is_finished(udev_queue, seqnum, seqnum)) |
422 | return 0; | |
f503f6b2 | 423 | |
912541b0 | 424 | return 1; |
64ccdf82 KS |
425 | } |
426 | ||
8d6bc73a KS |
427 | /** |
428 | * udev_queue_get_queued_list_entry: | |
429 | * @udev_queue: udev queue context | |
430 | * | |
21dbe43a KS |
431 | * Get the first entry of the list of queued events. |
432 | * | |
433 | * Returns: a udev_list_entry. | |
8d6bc73a | 434 | **/ |
54cf0b7f | 435 | _public_ struct udev_list_entry *udev_queue_get_queued_list_entry(struct udev_queue *udev_queue) |
64ccdf82 | 436 | { |
912541b0 KS |
437 | unsigned long long int seqnum; |
438 | FILE *queue_file; | |
439 | ||
440 | if (udev_queue == NULL) | |
441 | return NULL; | |
442 | udev_list_cleanup(&udev_queue->queue_list); | |
443 | ||
444 | queue_file = open_queue_file(udev_queue, &seqnum); | |
445 | if (queue_file == NULL) | |
446 | return NULL; | |
447 | ||
448 | for (;;) { | |
449 | char syspath[UTIL_PATH_SIZE]; | |
450 | char *s; | |
451 | size_t l; | |
452 | ssize_t len; | |
453 | char seqnum_str[32]; | |
454 | struct udev_list_entry *list_entry; | |
455 | ||
456 | if (udev_queue_read_seqnum(queue_file, &seqnum) < 0) | |
457 | break; | |
458 | snprintf(seqnum_str, sizeof(seqnum_str), "%llu", seqnum); | |
459 | ||
460 | s = syspath; | |
d5a89d7d | 461 | l = strpcpy(&s, sizeof(syspath), "/sys"); |
912541b0 KS |
462 | len = udev_queue_read_devpath(queue_file, s, l); |
463 | if (len < 0) | |
464 | break; | |
465 | ||
466 | if (len > 0) { | |
467 | udev_list_entry_add(&udev_queue->queue_list, syspath, seqnum_str); | |
468 | } else { | |
469 | udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_queue->queue_list)) { | |
090be865 | 470 | if (streq(seqnum_str, udev_list_entry_get_value(list_entry))) { |
912541b0 KS |
471 | udev_list_entry_delete(list_entry); |
472 | break; | |
473 | } | |
474 | } | |
475 | } | |
476 | } | |
477 | fclose(queue_file); | |
478 | ||
479 | return udev_list_get_entry(&udev_queue->queue_list); | |
64ccdf82 | 480 | } |