chiark / gitweb /
consistent key naming to match only the event device or include all parent devices
[elogind.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 }