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consistent key naming to match only the event device or include all parent devices
[thirdparty/systemd.git] / udev_rules_parse.c
1 /*
2 * udev_rules_parse.c
3 *
4 * Copyright (C) 2003,2004 Greg Kroah-Hartman <greg@kroah.com>
5 * Copyright (C) 2003-2005 Kay Sievers <kay.sievers@vrfy.org>
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License as published by the
9 * Free Software Foundation version 2 of the License.
10 *
11 * This program is distributed in the hope that it will be useful, but
12 * WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License along
17 * with this program; if not, write to the Free Software Foundation, Inc.,
18 * 675 Mass Ave, Cambridge, MA 02139, USA.
19 *
20 */
21
22 #include <stddef.h>
23 #include <stdlib.h>
24 #include <string.h>
25 #include <stdio.h>
26 #include <ctype.h>
27 #include <unistd.h>
28 #include <sys/stat.h>
29 #include <errno.h>
30
31 #include "udev.h"
32 #include "udev_rules.h"
33
34
35 void udev_rules_iter_init(struct udev_rules *rules)
36 {
37 dbg("bufsize=%zi", rules->bufsize);
38 rules->current = 0;
39 }
40
41 struct udev_rule *udev_rules_iter_next(struct udev_rules *rules)
42 {
43 static struct udev_rule *rule;
44
45 if (!rules)
46 return NULL;
47
48 dbg("current=%zi", rules->current);
49 if (rules->current >= rules->bufsize) {
50 dbg("no more rules");
51 return NULL;
52 }
53
54 /* get next rule */
55 rule = (struct udev_rule *) (rules->buf + rules->current);
56 rules->current += sizeof(struct udev_rule) + rule->bufsize;
57
58 return rule;
59 }
60
61 struct udev_rule *udev_rules_iter_label(struct udev_rules *rules, const char *label)
62 {
63 static struct udev_rule *rule;
64
65 next:
66 dbg("current=%zi", rules->current);
67 if (rules->current >= rules->bufsize) {
68 dbg("no more rules");
69 return NULL;
70 }
71 rule = (struct udev_rule *) (rules->buf + rules->current);
72
73 if (strcmp(&rule->buf[rule->label.val_off], label) != 0) {
74 dbg("moving forward, looking for label '%s'", label);
75 rules->current += sizeof(struct udev_rule) + rule->bufsize;
76 goto next;
77 }
78
79 dbg("found label '%s'", label);
80 return rule;
81 }
82
83 static int get_key(char **line, char **key, enum key_operation *operation, char **value)
84 {
85 char *linepos;
86 char *temp;
87
88 linepos = *line;
89 if (linepos == NULL && linepos[0] == '\0')
90 return -1;
91
92 /* skip whitespace */
93 while (isspace(linepos[0]) || linepos[0] == ',')
94 linepos++;
95
96 /* get the key */
97 if (linepos[0] == '\0')
98 return -1;
99 *key = linepos;
100
101 while (1) {
102 linepos++;
103 if (linepos[0] == '\0')
104 return -1;
105 if (isspace(linepos[0]))
106 break;
107 if (linepos[0] == '=')
108 break;
109 if (linepos[0] == '+')
110 break;
111 if (linepos[0] == '!')
112 break;
113 if (linepos[0] == ':')
114 break;
115 }
116
117 /* remember end of key */
118 temp = linepos;
119
120 /* skip whitespace after key */
121 while (isspace(linepos[0]))
122 linepos++;
123 if (linepos[0] == '\0')
124 return -1;
125
126 /* get operation type */
127 if (linepos[0] == '=' && linepos[1] == '=') {
128 *operation = KEY_OP_MATCH;
129 linepos += 2;
130 dbg("operator=match");
131 } else if (linepos[0] == '!' && linepos[1] == '=') {
132 *operation = KEY_OP_NOMATCH;
133 linepos += 2;
134 dbg("operator=nomatch");
135 } else if (linepos[0] == '+' && linepos[1] == '=') {
136 *operation = KEY_OP_ADD;
137 linepos += 2;
138 dbg("operator=add");
139 } else if (linepos[0] == '=') {
140 *operation = KEY_OP_ASSIGN;
141 linepos++;
142 dbg("operator=assign");
143 } else if (linepos[0] == ':' && linepos[1] == '=') {
144 *operation = KEY_OP_ASSIGN_FINAL;
145 linepos += 2;
146 dbg("operator=assign_final");
147 } else
148 return -1;
149
150 /* terminate key */
151 temp[0] = '\0';
152 dbg("key='%s'", *key);
153
154 /* skip whitespace after operator */
155 while (isspace(linepos[0]))
156 linepos++;
157 if (linepos[0] == '\0')
158 return -1;
159
160 /* get the value*/
161 if (linepos[0] == '"')
162 linepos++;
163 else
164 return -1;
165 *value = linepos;
166
167 temp = strchr(linepos, '"');
168 if (!temp)
169 return -1;
170 temp[0] = '\0';
171 temp++;
172 dbg("value='%s'", *value);
173
174 /* move line to next key */
175 *line = temp;
176
177 return 0;
178 }
179
180 /* extract possible KEY{attr} */
181 static char *get_key_attribute(char *str)
182 {
183 char *pos;
184 char *attr;
185
186 attr = strchr(str, '{');
187 if (attr != NULL) {
188 attr++;
189 pos = strchr(attr, '}');
190 if (pos == NULL) {
191 err("missing closing brace for format");
192 return NULL;
193 }
194 pos[0] = '\0';
195 dbg("attribute='%s'", attr);
196 return attr;
197 }
198
199 return NULL;
200 }
201
202 static int add_rule_key(struct udev_rule *rule, struct key *key,
203 enum key_operation operation, const char *value)
204 {
205 size_t val_len = strnlen(value, PATH_SIZE);
206
207 key->operation = operation;
208
209 key->val_off = rule->bufsize;
210 strlcpy(rule->buf + rule->bufsize, value, val_len+1);
211 rule->bufsize += val_len+1;
212
213 return 0;
214 }
215
216 static int add_rule_key_pair(struct udev_rule *rule, struct key_pairs *pairs,
217 enum key_operation operation, const char *key, const char *value)
218 {
219 size_t key_len = strnlen(key, PATH_SIZE);
220
221 if (pairs->count >= PAIRS_MAX) {
222 err("skip, too many keys in a single rule");
223 return -1;
224 }
225
226 add_rule_key(rule, &pairs->keys[pairs->count].key, operation, value);
227
228 /* add the key-name of the pair */
229 pairs->keys[pairs->count].key_name_off = rule->bufsize;
230 strlcpy(rule->buf + rule->bufsize, key, key_len+1);
231 rule->bufsize += key_len+1;
232
233 pairs->count++;
234
235 return 0;
236 }
237
238 static int add_to_rules(struct udev_rules *rules, char *line, const char *filename, unsigned int lineno)
239 {
240 struct udev_rule *rule;
241 size_t rule_size;
242 int valid;
243 char *linepos;
244 char *attr;
245 size_t padding;
246 int retval;
247
248 /* get all the keys */
249 rule = calloc(1, sizeof (struct udev_rule) + LINE_SIZE);
250 if (!rule) {
251 err("malloc failed");
252 return -1;
253 }
254 linepos = line;
255 valid = 0;
256
257 while (1) {
258 char *key;
259 char *value;
260 enum key_operation operation = KEY_OP_UNSET;
261
262 retval = get_key(&linepos, &key, &operation, &value);
263 if (retval)
264 break;
265
266 if (strcasecmp(key, "ACTION") == 0) {
267 if (operation != KEY_OP_MATCH &&
268 operation != KEY_OP_NOMATCH) {
269 err("invalid ACTION operation");
270 goto invalid;
271 }
272 add_rule_key(rule, &rule->action, operation, value);
273 valid = 1;
274 continue;
275 }
276
277 if (strcasecmp(key, "DEVPATH") == 0) {
278 if (operation != KEY_OP_MATCH &&
279 operation != KEY_OP_NOMATCH) {
280 err("invalid DEVPATH operation");
281 goto invalid;
282 }
283 add_rule_key(rule, &rule->devpath, operation, value);
284 valid = 1;
285 continue;
286 }
287
288 if (strcasecmp(key, "KERNEL") == 0) {
289 if (operation != KEY_OP_MATCH &&
290 operation != KEY_OP_NOMATCH) {
291 err("invalid KERNEL operation");
292 goto invalid;
293 }
294 add_rule_key(rule, &rule->kernel, operation, value);
295 valid = 1;
296 continue;
297 }
298
299 if (strcasecmp(key, "SUBSYSTEM") == 0) {
300 if (operation != KEY_OP_MATCH &&
301 operation != KEY_OP_NOMATCH) {
302 err("invalid SUBSYSTEM operation");
303 goto invalid;
304 }
305 add_rule_key(rule, &rule->subsystem, operation, value);
306 valid = 1;
307 continue;
308 }
309
310 if (strcasecmp(key, "DRIVER") == 0) {
311 if (operation != KEY_OP_MATCH &&
312 operation != KEY_OP_NOMATCH) {
313 err("invalid DRIVER operation");
314 goto invalid;
315 }
316 err("DRIVER== will change in a future relase, "
317 "please use DRIVERS== in %s:%u", filename, lineno);
318 /* FIXME: this should be rule->driver to match only the event device */
319 add_rule_key(rule, &rule->drivers, operation, value);
320 valid = 1;
321 continue;
322 }
323
324 if (strncasecmp(key, "ATTR", sizeof("ATTR")-1) == 0) {
325 if (operation != KEY_OP_MATCH &&
326 operation != KEY_OP_NOMATCH) {
327 err("invalid ATTR operation");
328 goto invalid;
329 }
330 attr = get_key_attribute(key + sizeof("ATTR")-1);
331 if (attr == NULL) {
332 err("error parsing ATTR attribute in '%s'", line);
333 continue;
334 }
335 add_rule_key_pair(rule, &rule->attr, operation, attr, value);
336 valid = 1;
337 continue;
338 }
339
340 if (strcasecmp(key, "KERNELS") == 0 ||
341 strcasecmp(key, "ID") == 0) {
342 if (operation != KEY_OP_MATCH &&
343 operation != KEY_OP_NOMATCH) {
344 err("invalid KERNELS operation");
345 goto invalid;
346 }
347 add_rule_key(rule, &rule->kernels, operation, value);
348 valid = 1;
349 continue;
350 }
351
352 if (strcasecmp(key, "SUBSYTEMS") == 0 ||
353 strcasecmp(key, "BUS") == 0) {
354 if (operation != KEY_OP_MATCH &&
355 operation != KEY_OP_NOMATCH) {
356 err("invalid SUBSYSTEMS operation");
357 goto invalid;
358 }
359 add_rule_key(rule, &rule->subsystems, operation, value);
360 valid = 1;
361 continue;
362 }
363
364 if (strcasecmp(key, "DRIVERS") == 0) {
365 if (operation != KEY_OP_MATCH &&
366 operation != KEY_OP_NOMATCH) {
367 err("invalid DRIVERS operation");
368 goto invalid;
369 }
370 add_rule_key(rule, &rule->drivers, operation, value);
371 valid = 1;
372 continue;
373 }
374
375 if (strncasecmp(key, "ATTRS", sizeof("ATTRS")-1) == 0 ||
376 strncasecmp(key, "SYSFS", sizeof("SYSFS")-1) == 0) {
377 if (operation != KEY_OP_MATCH &&
378 operation != KEY_OP_NOMATCH) {
379 err("invalid ATTRSS operation");
380 goto invalid;
381 }
382 attr = get_key_attribute(key + sizeof("ATTRS")-1);
383 if (attr == NULL) {
384 err("error parsing ATTRS attribute in '%s'", line);
385 continue;
386 }
387 add_rule_key_pair(rule, &rule->attrs, operation, attr, value);
388 valid = 1;
389 continue;
390 }
391
392 if (strncasecmp(key, "ENV", sizeof("ENV")-1) == 0) {
393 attr = get_key_attribute(key + sizeof("ENV")-1);
394 if (attr == NULL) {
395 err("error parsing ENV attribute");
396 continue;
397 }
398 add_rule_key_pair(rule, &rule->env, operation, attr, value);
399 valid = 1;
400 continue;
401 }
402
403 if (strcasecmp(key, "PROGRAM") == 0) {
404 add_rule_key(rule, &rule->program, operation, value);
405 valid = 1;
406 continue;
407 }
408
409 if (strcasecmp(key, "RESULT") == 0) {
410 if (operation != KEY_OP_MATCH &&
411 operation != KEY_OP_NOMATCH) {
412 err("invalid RESULT operation");
413 goto invalid;
414 }
415 add_rule_key(rule, &rule->result, operation, value);
416 valid = 1;
417 continue;
418 }
419
420 if (strncasecmp(key, "IMPORT", sizeof("IMPORT")-1) == 0) {
421 attr = get_key_attribute(key + sizeof("IMPORT")-1);
422 if (attr && strstr(attr, "program")) {
423 dbg("IMPORT will be executed");
424 rule->import_type = IMPORT_PROGRAM;
425 } else if (attr && strstr(attr, "file")) {
426 dbg("IMPORT will be included as file");
427 rule->import_type = IMPORT_FILE;
428 } else if (attr && strstr(attr, "parent")) {
429 dbg("IMPORT will include the parent values");
430 rule->import_type = IMPORT_PARENT;
431 } else {
432 /* figure it out if it is executable */
433 char file[PATH_SIZE];
434 char *pos;
435 struct stat stats;
436
437 strlcpy(file, value, sizeof(file));
438 pos = strchr(file, ' ');
439 if (pos)
440 pos[0] = '\0';
441
442 /* allow programs in /lib/udev called without the path */
443 if (strchr(file, '/') == NULL) {
444 strlcpy(file, "/lib/udev/", sizeof(file));
445 strlcat(file, value, sizeof(file));
446 pos = strchr(file, ' ');
447 if (pos)
448 pos[0] = '\0';
449 }
450
451 dbg("IMPORT auto mode for '%s'", file);
452 if (!lstat(file, &stats) && (stats.st_mode & S_IXUSR)) {
453 dbg("IMPORT is executable, will be executed (autotype)");
454 rule->import_type = IMPORT_PROGRAM;
455 } else {
456 dbg("IMPORT is not executable, will be included as file (autotype)");
457 rule->import_type = IMPORT_FILE;
458 }
459 }
460 add_rule_key(rule, &rule->import, operation, value);
461 valid = 1;
462 continue;
463 }
464
465 if (strcasecmp(key, "RUN") == 0) {
466 add_rule_key(rule, &rule->run, operation, value);
467 valid = 1;
468 continue;
469 }
470
471 if (strcasecmp(key, "WAIT_FOR_SYSFS") == 0) {
472 add_rule_key(rule, &rule->wait_for_sysfs, operation, value);
473 valid = 1;
474 continue;
475 }
476
477 if (strcasecmp(key, "LABEL") == 0) {
478 add_rule_key(rule, &rule->label, operation, value);
479 valid = 1;
480 continue;
481 }
482
483 if (strcasecmp(key, "GOTO") == 0) {
484 add_rule_key(rule, &rule->goto_label, operation, value);
485 valid = 1;
486 continue;
487 }
488
489 if (strncasecmp(key, "NAME", sizeof("NAME")-1) == 0) {
490 attr = get_key_attribute(key + sizeof("NAME")-1);
491 if (attr != NULL) {
492 if (strstr(attr, "all_partitions") != NULL) {
493 dbg("creation of partition nodes requested");
494 rule->partitions = DEFAULT_PARTITIONS_COUNT;
495 }
496 if (strstr(attr, "ignore_remove") != NULL) {
497 dbg("remove event should be ignored");
498 rule->ignore_remove = 1;
499 }
500 }
501 if (value[0] == '\0')
502 dbg("name empty, node creation supressed");
503 add_rule_key(rule, &rule->name, operation, value);
504 continue;
505 }
506
507 if (strcasecmp(key, "SYMLINK") == 0) {
508 add_rule_key(rule, &rule->symlink, operation, value);
509 valid = 1;
510 continue;
511 }
512
513 if (strcasecmp(key, "OWNER") == 0) {
514 valid = 1;
515 if (rules->resolve_names && (!strchr(value, '$') && !strchr(value, '%'))) {
516 char *endptr;
517 strtoul(value, &endptr, 10);
518 if (endptr[0] != '\0') {
519 char owner[32];
520 uid_t uid = lookup_user(value);
521 dbg("replacing username='%s' by id=%i", value, uid);
522 sprintf(owner, "%u", (unsigned int) uid);
523 add_rule_key(rule, &rule->owner, operation, owner);
524 continue;
525 }
526 }
527
528 add_rule_key(rule, &rule->owner, operation, value);
529 continue;
530 }
531
532 if (strcasecmp(key, "GROUP") == 0) {
533 valid = 1;
534 if (rules->resolve_names && (!strchr(value, '$') && !strchr(value, '%'))) {
535 char *endptr;
536 strtoul(value, &endptr, 10);
537 if (endptr[0] != '\0') {
538 char group[32];
539 gid_t gid = lookup_group(value);
540 dbg("replacing groupname='%s' by id=%i", value, gid);
541 sprintf(group, "%u", (unsigned int) gid);
542 add_rule_key(rule, &rule->group, operation, group);
543 continue;
544 }
545 }
546
547 add_rule_key(rule, &rule->group, operation, value);
548 continue;
549 }
550
551 if (strcasecmp(key, "MODE") == 0) {
552 rule->mode = strtol(value, NULL, 8);
553 rule->mode_operation = operation;
554 valid = 1;
555 continue;
556 }
557
558 if (strcasecmp(key, "OPTIONS") == 0) {
559 if (strstr(value, "last_rule") != NULL) {
560 dbg("last rule to be applied");
561 rule->last_rule = 1;
562 }
563 if (strstr(value, "ignore_device") != NULL) {
564 dbg("device should be ignored");
565 rule->ignore_device = 1;
566 }
567 if (strstr(value, "ignore_remove") != NULL) {
568 dbg("remove event should be ignored");
569 rule->ignore_remove = 1;
570 }
571 if (strstr(value, "all_partitions") != NULL) {
572 dbg("creation of partition nodes requested");
573 rule->partitions = DEFAULT_PARTITIONS_COUNT;
574 }
575 valid = 1;
576 continue;
577 }
578
579 err("unknown key '%s' in %s:%u", key, filename, lineno);
580 }
581
582 /* skip line if not any valid key was found */
583 if (!valid)
584 goto invalid;
585
586 /* grow buffer and add rule */
587 rule_size = sizeof(struct udev_rule) + rule->bufsize;
588 padding = (sizeof(size_t) - rule_size % sizeof(size_t)) % sizeof(size_t);
589 dbg("add %zi padding bytes", padding);
590 rule_size += padding;
591 rule->bufsize += padding;
592
593 rules->buf = realloc(rules->buf, rules->bufsize + rule_size);
594 if (!rules->buf) {
595 err("realloc failed");
596 goto exit;
597 }
598 dbg("adding rule to offset %zi", rules->bufsize);
599 memcpy(rules->buf + rules->bufsize, rule, rule_size);
600 rules->bufsize += rule_size;
601 exit:
602 free(rule);
603 return 0;
604
605 invalid:
606 free(rule);
607 err("invalid rule '%s:%u'", filename, lineno);
608 return -1;
609 }
610
611 static int parse_file(struct udev_rules *rules, const char *filename)
612 {
613 char line[LINE_SIZE];
614 char *bufline;
615 unsigned int lineno;
616 char *buf;
617 size_t bufsize;
618 size_t cur;
619 size_t count;
620 int retval = 0;
621
622 if (file_map(filename, &buf, &bufsize) != 0) {
623 err("can't open '%s' as rules file: %s", filename, strerror(errno));
624 return -1;
625 }
626 dbg("reading '%s' as rules file", filename);
627
628 /* loop through the whole file */
629 cur = 0;
630 lineno = 0;
631 while (cur < bufsize) {
632 unsigned int i, j;
633
634 count = buf_get_line(buf, bufsize, cur);
635 bufline = &buf[cur];
636 cur += count+1;
637 lineno++;
638
639 /* eat the whitespace */
640 while ((count > 0) && isspace(bufline[0])) {
641 bufline++;
642 count--;
643 }
644 if (count == 0)
645 continue;
646
647 /* see if this is a comment */
648 if (bufline[0] == COMMENT_CHARACTER)
649 continue;
650
651 if (count >= sizeof(line)) {
652 err("line too long, rule skipped '%s:%u'", filename, lineno);
653 continue;
654 }
655
656 /* skip backslash and newline from multiline rules */
657 for (i = j = 0; i < count; i++) {
658 if (bufline[i] == '\\' && bufline[i+1] == '\n')
659 continue;
660
661 line[j++] = bufline[i];
662 }
663 line[j] = '\0';
664
665 dbg("read '%s'", line);
666 add_to_rules(rules, line, filename, lineno);
667 }
668
669 file_unmap(buf, bufsize);
670 return retval;
671 }
672
673 int udev_rules_init(struct udev_rules *rules, int resolve_names)
674 {
675 struct stat stats;
676 int retval;
677
678 memset(rules, 0x00, sizeof(struct udev_rules));
679 rules->resolve_names = resolve_names;
680
681 /* parse rules file or all matching files in directory */
682 if (stat(udev_rules_filename, &stats) != 0)
683 return -1;
684
685 if ((stats.st_mode & S_IFMT) != S_IFDIR) {
686 dbg("parse single rules file '%s'", udev_rules_filename);
687 retval = parse_file(rules, udev_rules_filename);
688 } else {
689 struct name_entry *name_loop, *name_tmp;
690 LIST_HEAD(name_list);
691
692 dbg("parse rules directory '%s'", udev_rules_filename);
693 retval = add_matching_files(&name_list, udev_rules_filename, RULEFILE_SUFFIX);
694
695 list_for_each_entry_safe(name_loop, name_tmp, &name_list, node) {
696 if (stat(name_loop->name, &stats) == 0) {
697 if (stats.st_size)
698 parse_file(rules, name_loop->name);
699 else
700 dbg("empty rules file '%s'", name_loop->name);
701 } else
702 err("could not read '%s': %s", name_loop->name, strerror(errno));
703 list_del(&name_loop->node);
704 free(name_loop);
705 }
706 }
707
708 return retval;
709 }
710
711 void udev_rules_cleanup(struct udev_rules *rules)
712 {
713 if (rules->buf) {
714 free(rules->buf);
715 rules->buf = NULL;
716 }
717 }