chiark / gitweb /
udevd: init signal pipe before daemonizing
[elogind.git] / udev_rules_parse.c
1 /*
2  * Copyright (C) 2003,2004 Greg Kroah-Hartman <greg@kroah.com>
3  * Copyright (C) 2003-2006 Kay Sievers <kay.sievers@vrfy.org>
4  *
5  *      This program is free software; you can redistribute it and/or modify it
6  *      under the terms of the GNU General Public License as published by the
7  *      Free Software Foundation version 2 of the License.
8  * 
9  *      This program is distributed in the hope that it will be useful, but
10  *      WITHOUT ANY WARRANTY; without even the implied warranty of
11  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12  *      General Public License for more details.
13  * 
14  *      You should have received a copy of the GNU General Public License along
15  *      with this program; if not, write to the Free Software Foundation, Inc.,
16  *      51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
17  *
18  */
19
20 #include <stddef.h>
21 #include <stdlib.h>
22 #include <string.h>
23 #include <stdio.h>
24 #include <ctype.h>
25 #include <unistd.h>
26 #include <sys/stat.h>
27 #include <errno.h>
28
29 #include "udev.h"
30 #include "udev_rules.h"
31
32
33 void udev_rules_iter_init(struct udev_rules *rules)
34 {
35         dbg("bufsize=%zi", rules->bufsize);
36         rules->current = 0;
37 }
38
39 struct udev_rule *udev_rules_iter_next(struct udev_rules *rules)
40 {
41         static struct udev_rule *rule;
42
43         if (!rules)
44                 return NULL;
45
46         dbg("current=%zi", rules->current);
47         if (rules->current >= rules->bufsize) {
48                 dbg("no more rules");
49                 return NULL;
50         }
51
52         /* get next rule */
53         rule = (struct udev_rule *) (rules->buf + rules->current);
54         rules->current += sizeof(struct udev_rule) + rule->bufsize;
55
56         return rule;
57 }
58
59 struct udev_rule *udev_rules_iter_label(struct udev_rules *rules, const char *label)
60 {
61         static struct udev_rule *rule;
62
63 next:
64         dbg("current=%zi", rules->current);
65         if (rules->current >= rules->bufsize) {
66                 dbg("no more rules");
67                 return NULL;
68         }
69         rule = (struct udev_rule *) (rules->buf + rules->current);
70
71         if (strcmp(&rule->buf[rule->label.val_off], label) != 0) {
72                 dbg("moving forward, looking for label '%s'", label);
73                 rules->current += sizeof(struct udev_rule) + rule->bufsize;
74                 goto next;
75         }
76
77         dbg("found label '%s'", label);
78         return rule;
79 }
80
81 static int get_key(char **line, char **key, enum key_operation *operation, char **value)
82 {
83         char *linepos;
84         char *temp;
85
86         linepos = *line;
87         if (linepos == NULL && linepos[0] == '\0')
88                 return -1;
89
90         /* skip whitespace */
91         while (isspace(linepos[0]) || linepos[0] == ',')
92                 linepos++;
93
94         /* get the key */
95         if (linepos[0] == '\0')
96                 return -1;
97         *key = linepos;
98
99         while (1) {
100                 linepos++;
101                 if (linepos[0] == '\0')
102                         return -1;
103                 if (isspace(linepos[0]))
104                         break;
105                 if (linepos[0] == '=')
106                         break;
107                 if (linepos[0] == '+')
108                         break;
109                 if (linepos[0] == '!')
110                         break;
111                 if (linepos[0] == ':')
112                         break;
113         }
114
115         /* remember end of key */
116         temp = linepos;
117
118         /* skip whitespace after key */
119         while (isspace(linepos[0]))
120                 linepos++;
121         if (linepos[0] == '\0')
122                 return -1;
123
124         /* get operation type */
125         if (linepos[0] == '=' && linepos[1] == '=') {
126                 *operation = KEY_OP_MATCH;
127                 linepos += 2;
128                 dbg("operator=match");
129         } else if (linepos[0] == '!' && linepos[1] == '=') {
130                 *operation = KEY_OP_NOMATCH;
131                 linepos += 2;
132                 dbg("operator=nomatch");
133         } else if (linepos[0] == '+' && linepos[1] == '=') {
134                 *operation = KEY_OP_ADD;
135                 linepos += 2;
136                 dbg("operator=add");
137         } else if (linepos[0] == '=') {
138                 *operation = KEY_OP_ASSIGN;
139                 linepos++;
140                 dbg("operator=assign");
141         } else if (linepos[0] == ':' && linepos[1] == '=') {
142                 *operation = KEY_OP_ASSIGN_FINAL;
143                 linepos += 2;
144                 dbg("operator=assign_final");
145         } else
146                 return -1;
147
148         /* terminate key */
149         temp[0] = '\0';
150         dbg("key='%s'", *key);
151
152         /* skip whitespace after operator */
153         while (isspace(linepos[0]))
154                 linepos++;
155         if (linepos[0] == '\0')
156                 return -1;
157
158         /* get the value*/
159         if (linepos[0] == '"')
160                 linepos++;
161         else
162                 return -1;
163         *value = linepos;
164
165         temp = strchr(linepos, '"');
166         if (!temp)
167                 return -1;
168         temp[0] = '\0';
169         temp++;
170         dbg("value='%s'", *value);
171
172         /* move line to next key */
173         *line = temp;
174
175         return 0;
176 }
177
178 /* extract possible KEY{attr} */
179 static char *get_key_attribute(char *str)
180 {
181         char *pos;
182         char *attr;
183
184         attr = strchr(str, '{');
185         if (attr != NULL) {
186                 attr++;
187                 pos = strchr(attr, '}');
188                 if (pos == NULL) {
189                         err("missing closing brace for format");
190                         return NULL;
191                 }
192                 pos[0] = '\0';
193                 dbg("attribute='%s'", attr);
194                 return attr;
195         }
196
197         return NULL;
198 }
199
200 static int add_rule_key(struct udev_rule *rule, struct key *key,
201                         enum key_operation operation, const char *value)
202 {
203         size_t val_len = strnlen(value, PATH_SIZE);
204
205         key->operation = operation;
206
207         key->val_off = rule->bufsize;
208         strlcpy(rule->buf + rule->bufsize, value, val_len+1);
209         rule->bufsize += val_len+1;
210
211         return 0;
212 }
213
214 static int add_rule_key_pair(struct udev_rule *rule, struct key_pairs *pairs,
215                              enum key_operation operation, const char *key, const char *value)
216 {
217         size_t key_len = strnlen(key, PATH_SIZE);
218
219         if (pairs->count >= PAIRS_MAX) {
220                 err("skip, too many keys of the same type in a single rule");
221                 return -1;
222         }
223
224         add_rule_key(rule, &pairs->keys[pairs->count].key, operation, value);
225
226         /* add the key-name of the pair */
227         pairs->keys[pairs->count].key_name_off = rule->bufsize;
228         strlcpy(rule->buf + rule->bufsize, key, key_len+1);
229         rule->bufsize += key_len+1;
230
231         pairs->count++;
232
233         return 0;
234 }
235
236 static int add_to_rules(struct udev_rules *rules, char *line, const char *filename, unsigned int lineno)
237 {
238         struct udev_rule *rule;
239         size_t rule_size;
240         int valid;
241         char *linepos;
242         char *attr;
243         size_t padding;
244         int physdev = 0;
245         int retval;
246
247         /* get all the keys */
248         rule = calloc(1, sizeof (struct udev_rule) + LINE_SIZE);
249         if (!rule) {
250                 err("malloc failed");
251                 return -1;
252         }
253         linepos = line;
254         valid = 0;
255
256         while (1) {
257                 char *key;
258                 char *value;
259                 enum key_operation operation = KEY_OP_UNSET;
260
261                 retval = get_key(&linepos, &key, &operation, &value);
262                 if (retval)
263                         break;
264
265                 if (strcasecmp(key, "ACTION") == 0) {
266                         if (operation != KEY_OP_MATCH &&
267                             operation != KEY_OP_NOMATCH) {
268                                 err("invalid ACTION operation");
269                                 goto invalid;
270                         }
271                         add_rule_key(rule, &rule->action, operation, value);
272                         valid = 1;
273                         continue;
274                 }
275
276                 if (strcasecmp(key, "DEVPATH") == 0) {
277                         if (operation != KEY_OP_MATCH &&
278                             operation != KEY_OP_NOMATCH) {
279                                 err("invalid DEVPATH operation");
280                                 goto invalid;
281                         }
282                         add_rule_key(rule, &rule->devpath, operation, value);
283                         valid = 1;
284                         continue;
285                 }
286
287                 if (strcasecmp(key, "KERNEL") == 0) {
288                         if (operation != KEY_OP_MATCH &&
289                             operation != KEY_OP_NOMATCH) {
290                                 err("invalid KERNEL operation");
291                                 goto invalid;
292                         }
293                         add_rule_key(rule, &rule->kernel, operation, value);
294                         valid = 1;
295                         continue;
296                 }
297
298                 if (strcasecmp(key, "SUBSYSTEM") == 0) {
299                         if (operation != KEY_OP_MATCH &&
300                             operation != KEY_OP_NOMATCH) {
301                                 err("invalid SUBSYSTEM operation");
302                                 goto invalid;
303                         }
304                         add_rule_key(rule, &rule->subsystem, operation, value);
305                         valid = 1;
306                         continue;
307                 }
308
309                 if (strcasecmp(key, "DRIVER") == 0) {
310                         if (operation != KEY_OP_MATCH &&
311                             operation != KEY_OP_NOMATCH) {
312                                 err("invalid DRIVER operation");
313                                 goto invalid;
314                         }
315                         err("DRIVER== will change in a future relase, "
316                             "please use DRIVERS== in %s:%u", filename, lineno);
317                         /* FIXME: this should be rule->driver to match only the event device */
318                         add_rule_key(rule, &rule->drivers, operation, value);
319                         valid = 1;
320                         continue;
321                 }
322
323                 if (strncasecmp(key, "ATTR{", sizeof("ATTR{")-1) == 0) {
324                         attr = get_key_attribute(key + sizeof("ATTR")-1);
325                         if (attr == NULL) {
326                                 err("error parsing ATTR attribute");
327                                 goto invalid;
328                         }
329                         if (add_rule_key_pair(rule, &rule->attr, operation, attr, value) != 0)
330                                 goto invalid;
331                         valid = 1;
332                         continue;
333                 }
334
335                 if (strcasecmp(key, "KERNELS") == 0 ||
336                     strcasecmp(key, "ID") == 0) {
337                         if (operation != KEY_OP_MATCH &&
338                             operation != KEY_OP_NOMATCH) {
339                                 err("invalid KERNELS operation");
340                                 goto invalid;
341                         }
342                         add_rule_key(rule, &rule->kernels, operation, value);
343                         valid = 1;
344                         continue;
345                 }
346
347                 if (strcasecmp(key, "SUBSYSTEMS") == 0 ||
348                     strcasecmp(key, "BUS") == 0) {
349                         if (operation != KEY_OP_MATCH &&
350                             operation != KEY_OP_NOMATCH) {
351                                 err("invalid SUBSYSTEMS operation");
352                                 goto invalid;
353                         }
354                         add_rule_key(rule, &rule->subsystems, operation, value);
355                         valid = 1;
356                         continue;
357                 }
358
359                 if (strcasecmp(key, "DRIVERS") == 0) {
360                         if (operation != KEY_OP_MATCH &&
361                             operation != KEY_OP_NOMATCH) {
362                                 err("invalid DRIVERS operation");
363                                 goto invalid;
364                         }
365                         add_rule_key(rule, &rule->drivers, operation, value);
366                         valid = 1;
367                         continue;
368                 }
369
370                 if (strncasecmp(key, "ATTRS{", sizeof("ATTRS{")-1) == 0 ||
371                     strncasecmp(key, "SYSFS{", sizeof("SYSFS{")-1) == 0) {
372                         attr = get_key_attribute(key + sizeof("ATTRS")-1);
373                         if (attr == NULL) {
374                                 err("error parsing ATTRS attribute");
375                                 goto invalid;
376                         }
377                         if (strncmp(attr, "device/", 7) == 0)
378                                 err("the 'device' link is deprecated and will be removed from a future kernel, "
379                                     "please fix it in %s:%u", filename, lineno);
380                         else if (strchr(attr, '/') != NULL)
381                                 err("do not reference parent sysfs directories directly, that may break with a future kernel, "
382                                     "please fix it in %s:%u", filename, lineno);
383                         if (add_rule_key_pair(rule, &rule->attrs, operation, attr, value) != 0)
384                                 goto invalid;
385                         valid = 1;
386                         continue;
387                 }
388
389                 if (strncasecmp(key, "ENV{", sizeof("ENV{")-1) == 0) {
390                         attr = get_key_attribute(key + sizeof("ENV")-1);
391                         if (attr == NULL) {
392                                 err("error parsing ENV attribute");
393                                 goto invalid;
394                         }
395                         if (strncmp(attr, "PHYSDEV", 7) == 0)
396                                 physdev = 1;
397                         if (add_rule_key_pair(rule, &rule->env, operation, attr, value) != 0)
398                                 goto invalid;
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         if (physdev && rule->wait_for_sysfs.operation == KEY_OP_UNSET)
583                 err("PHYSDEV* values are deprecated and will be removed from a future kernel, "
584                     "please fix it in %s:%u", filename, lineno);
585
586         /* skip line if not any valid key was found */
587         if (!valid)
588                 goto invalid;
589
590         /* grow buffer and add rule */
591         rule_size = sizeof(struct udev_rule) + rule->bufsize;
592         padding = (sizeof(size_t) - rule_size % sizeof(size_t)) % sizeof(size_t);
593         dbg("add %zi padding bytes", padding);
594         rule_size += padding;
595         rule->bufsize += padding;
596
597         rules->buf = realloc(rules->buf, rules->bufsize + rule_size);
598         if (!rules->buf) {
599                 err("realloc failed");
600                 goto exit;
601         }
602         dbg("adding rule to offset %zi", rules->bufsize);
603         memcpy(rules->buf + rules->bufsize, rule, rule_size);
604         rules->bufsize += rule_size;
605 exit:
606         free(rule);
607         return 0;
608
609 invalid:
610         free(rule);
611         err("invalid rule '%s:%u'", filename, lineno);
612         return -1;
613 }
614
615 static int parse_file(struct udev_rules *rules, const char *filename)
616 {
617         char line[LINE_SIZE];
618         char *bufline;
619         unsigned int lineno;
620         char *buf;
621         size_t bufsize;
622         size_t cur;
623         size_t count;
624         int retval = 0;
625
626         if (file_map(filename, &buf, &bufsize) != 0) {
627                 err("can't open '%s' as rules file: %s", filename, strerror(errno));
628                 return -1;
629         }
630         info("reading '%s' as rules file", filename);
631
632         /* loop through the whole file */
633         cur = 0;
634         lineno = 0;
635         while (cur < bufsize) {
636                 unsigned int i, j;
637
638                 count = buf_get_line(buf, bufsize, cur);
639                 bufline = &buf[cur];
640                 cur += count+1;
641                 lineno++;
642
643                 /* eat the whitespace */
644                 while ((count > 0) && isspace(bufline[0])) {
645                         bufline++;
646                         count--;
647                 }
648                 if (count == 0)
649                         continue;
650
651                 /* see if this is a comment */
652                 if (bufline[0] == COMMENT_CHARACTER)
653                         continue;
654
655                 if (count >= sizeof(line)) {
656                         err("line too long, rule skipped '%s:%u'", filename, lineno);
657                         continue;
658                 }
659
660                 /* skip backslash and newline from multiline rules */
661                 for (i = j = 0; i < count; i++) {
662                         if (bufline[i] == '\\' && bufline[i+1] == '\n')
663                                 continue;
664
665                         line[j++] = bufline[i];
666                 }
667                 line[j] = '\0';
668
669                 dbg("read '%s'", line);
670                 add_to_rules(rules, line, filename, lineno);
671         }
672
673         file_unmap(buf, bufsize);
674         return retval;
675 }
676
677 int udev_rules_init(struct udev_rules *rules, int resolve_names)
678 {
679         struct stat stats;
680         int retval;
681
682         memset(rules, 0x00, sizeof(struct udev_rules));
683         rules->resolve_names = resolve_names;
684
685         /* parse rules file or all matching files in directory */
686         if (stat(udev_rules_dir, &stats) != 0)
687                 return -1;
688
689         if ((stats.st_mode & S_IFMT) != S_IFDIR) {
690                 dbg("parse single rules file '%s'", udev_rules_dir);
691                 retval = parse_file(rules, udev_rules_dir);
692         } else {
693                 struct name_entry *name_loop, *name_tmp;
694                 LIST_HEAD(name_list);
695
696                 dbg("parse rules directory '%s'", udev_rules_dir);
697                 retval = add_matching_files(&name_list, udev_rules_dir, RULESFILE_SUFFIX);
698
699                 list_for_each_entry_safe(name_loop, name_tmp, &name_list, node) {
700                         if (stat(name_loop->name, &stats) == 0) {
701                                 if (stats.st_size)
702                                         parse_file(rules, name_loop->name);
703                                 else
704                                         dbg("empty rules file '%s'", name_loop->name);
705                         } else
706                                 err("could not read '%s': %s", name_loop->name, strerror(errno));
707                         list_del(&name_loop->node);
708                         free(name_loop);
709                 }
710         }
711
712         return retval;
713 }
714
715 void udev_rules_cleanup(struct udev_rules *rules)
716 {
717         if (rules->buf) {
718                 free(rules->buf);
719                 rules->buf = NULL;
720         }
721 }