chiark / gitweb /
8ef5ffee46431dd3e60510240eeb851d39e0af73
[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                         add_rule_key(rule, &rule->driver, operation, value);
316                         valid = 1;
317                         continue;
318                 }
319
320                 if (strncasecmp(key, "ATTR{", sizeof("ATTR{")-1) == 0) {
321                         attr = get_key_attribute(key + sizeof("ATTR")-1);
322                         if (attr == NULL) {
323                                 err("error parsing ATTR attribute");
324                                 goto invalid;
325                         }
326                         if (add_rule_key_pair(rule, &rule->attr, operation, attr, value) != 0)
327                                 goto invalid;
328                         valid = 1;
329                         continue;
330                 }
331
332                 if (strcasecmp(key, "KERNELS") == 0 ||
333                     strcasecmp(key, "ID") == 0) {
334                         if (operation != KEY_OP_MATCH &&
335                             operation != KEY_OP_NOMATCH) {
336                                 err("invalid KERNELS operation");
337                                 goto invalid;
338                         }
339                         add_rule_key(rule, &rule->kernels, operation, value);
340                         valid = 1;
341                         continue;
342                 }
343
344                 if (strcasecmp(key, "SUBSYSTEMS") == 0 ||
345                     strcasecmp(key, "BUS") == 0) {
346                         if (operation != KEY_OP_MATCH &&
347                             operation != KEY_OP_NOMATCH) {
348                                 err("invalid SUBSYSTEMS operation");
349                                 goto invalid;
350                         }
351                         add_rule_key(rule, &rule->subsystems, operation, value);
352                         valid = 1;
353                         continue;
354                 }
355
356                 if (strcasecmp(key, "DRIVERS") == 0) {
357                         if (operation != KEY_OP_MATCH &&
358                             operation != KEY_OP_NOMATCH) {
359                                 err("invalid DRIVERS operation");
360                                 goto invalid;
361                         }
362                         add_rule_key(rule, &rule->drivers, operation, value);
363                         valid = 1;
364                         continue;
365                 }
366
367                 if (strncasecmp(key, "ATTRS{", sizeof("ATTRS{")-1) == 0 ||
368                     strncasecmp(key, "SYSFS{", sizeof("SYSFS{")-1) == 0) {
369                         if (operation != KEY_OP_MATCH &&
370                             operation != KEY_OP_NOMATCH) {
371                                 err("invalid ATTRS operation");
372                                 goto invalid;
373                         }
374                         attr = get_key_attribute(key + sizeof("ATTRS")-1);
375                         if (attr == NULL) {
376                                 err("error parsing ATTRS attribute");
377                                 goto invalid;
378                         }
379                         if (strncmp(attr, "device/", 7) == 0)
380                                 err("the 'device' link is deprecated and will be removed from a future kernel, "
381                                     "please fix it in %s:%u", filename, lineno);
382                         else if (strchr(attr, '/') != NULL)
383                                 err("do not reference parent sysfs directories directly, that may break with a future kernel, "
384                                     "please fix it in %s:%u", filename, lineno);
385                         if (add_rule_key_pair(rule, &rule->attrs, operation, attr, value) != 0)
386                                 goto invalid;
387                         valid = 1;
388                         continue;
389                 }
390
391                 if (strncasecmp(key, "ENV{", sizeof("ENV{")-1) == 0) {
392                         attr = get_key_attribute(key + sizeof("ENV")-1);
393                         if (attr == NULL) {
394                                 err("error parsing ENV attribute");
395                                 goto invalid;
396                         }
397                         if (strncmp(attr, "PHYSDEV", 7) == 0)
398                                 physdev = 1;
399                         if (add_rule_key_pair(rule, &rule->env, operation, attr, value) != 0)
400                                 goto invalid;
401                         valid = 1;
402                         continue;
403                 }
404
405                 if (strcasecmp(key, "PROGRAM") == 0) {
406                         add_rule_key(rule, &rule->program, operation, value);
407                         valid = 1;
408                         continue;
409                 }
410
411                 if (strcasecmp(key, "RESULT") == 0) {
412                         if (operation != KEY_OP_MATCH &&
413                             operation != KEY_OP_NOMATCH) {
414                                 err("invalid RESULT operation");
415                                 goto invalid;
416                         }
417                         add_rule_key(rule, &rule->result, operation, value);
418                         valid = 1;
419                         continue;
420                 }
421
422                 if (strncasecmp(key, "IMPORT", sizeof("IMPORT")-1) == 0) {
423                         attr = get_key_attribute(key + sizeof("IMPORT")-1);
424                         if (attr && strstr(attr, "program")) {
425                                 dbg("IMPORT will be executed");
426                                 rule->import_type  = IMPORT_PROGRAM;
427                         } else if (attr && strstr(attr, "file")) {
428                                 dbg("IMPORT will be included as file");
429                                 rule->import_type  = IMPORT_FILE;
430                         } else if (attr && strstr(attr, "parent")) {
431                                 dbg("IMPORT will include the parent values");
432                                 rule->import_type = IMPORT_PARENT;
433                         } else {
434                                 /* figure it out if it is executable */
435                                 char file[PATH_SIZE];
436                                 char *pos;
437                                 struct stat stats;
438
439                                 strlcpy(file, value, sizeof(file));
440                                 pos = strchr(file, ' ');
441                                 if (pos)
442                                         pos[0] = '\0';
443
444                                 /* allow programs in /lib/udev called without the path */
445                                 if (strchr(file, '/') == NULL) {
446                                         strlcpy(file, "/lib/udev/", sizeof(file));
447                                         strlcat(file, value, sizeof(file));
448                                         pos = strchr(file, ' ');
449                                         if (pos)
450                                                 pos[0] = '\0';
451                                 }
452
453                                 dbg("IMPORT auto mode for '%s'", file);
454                                 if (!lstat(file, &stats) && (stats.st_mode & S_IXUSR)) {
455                                         dbg("IMPORT is executable, will be executed (autotype)");
456                                         rule->import_type  = IMPORT_PROGRAM;
457                                 } else {
458                                         dbg("IMPORT is not executable, will be included as file (autotype)");
459                                         rule->import_type  = IMPORT_FILE;
460                                 }
461                         }
462                         add_rule_key(rule, &rule->import, operation, value);
463                         valid = 1;
464                         continue;
465                 }
466
467                 if (strcasecmp(key, "RUN") == 0) {
468                         add_rule_key(rule, &rule->run, operation, value);
469                         valid = 1;
470                         continue;
471                 }
472
473                 if (strcasecmp(key, "WAIT_FOR_SYSFS") == 0) {
474                         add_rule_key(rule, &rule->wait_for_sysfs, operation, value);
475                         valid = 1;
476                         continue;
477                 }
478
479                 if (strcasecmp(key, "LABEL") == 0) {
480                         add_rule_key(rule, &rule->label, operation, value);
481                         valid = 1;
482                         continue;
483                 }
484
485                 if (strcasecmp(key, "GOTO") == 0) {
486                         add_rule_key(rule, &rule->goto_label, operation, value);
487                         valid = 1;
488                         continue;
489                 }
490
491                 if (strncasecmp(key, "NAME", sizeof("NAME")-1) == 0) {
492                         attr = get_key_attribute(key + sizeof("NAME")-1);
493                         if (attr != NULL) {
494                                 if (strstr(attr, "all_partitions") != NULL) {
495                                         dbg("creation of partition nodes requested");
496                                         rule->partitions = DEFAULT_PARTITIONS_COUNT;
497                                 }
498                                 if (strstr(attr, "ignore_remove") != NULL) {
499                                         dbg("remove event should be ignored");
500                                         rule->ignore_remove = 1;
501                                 }
502                         }
503                         if (value[0] == '\0')
504                                 dbg("name empty, node creation supressed");
505                         add_rule_key(rule, &rule->name, operation, value);
506                         continue;
507                 }
508
509                 if (strcasecmp(key, "SYMLINK") == 0) {
510                         add_rule_key(rule, &rule->symlink, operation, value);
511                         valid = 1;
512                         continue;
513                 }
514
515                 if (strcasecmp(key, "OWNER") == 0) {
516                         valid = 1;
517                         if (rules->resolve_names && (!strchr(value, '$') && !strchr(value, '%'))) {
518                                 char *endptr;
519                                 strtoul(value, &endptr, 10);
520                                 if (endptr[0] != '\0') {
521                                         char owner[32];
522                                         uid_t uid = lookup_user(value);
523                                         dbg("replacing username='%s' by id=%i", value, uid);
524                                         sprintf(owner, "%u", (unsigned int) uid);
525                                         add_rule_key(rule, &rule->owner, operation, owner);
526                                         continue;
527                                 }
528                         }
529
530                         add_rule_key(rule, &rule->owner, operation, value);
531                         continue;
532                 }
533
534                 if (strcasecmp(key, "GROUP") == 0) {
535                         valid = 1;
536                         if (rules->resolve_names && (!strchr(value, '$') && !strchr(value, '%'))) {
537                                 char *endptr;
538                                 strtoul(value, &endptr, 10);
539                                 if (endptr[0] != '\0') {
540                                         char group[32];
541                                         gid_t gid = lookup_group(value);
542                                         dbg("replacing groupname='%s' by id=%i", value, gid);
543                                         sprintf(group, "%u", (unsigned int) gid);
544                                         add_rule_key(rule, &rule->group, operation, group);
545                                         continue;
546                                 }
547                         }
548
549                         add_rule_key(rule, &rule->group, operation, value);
550                         continue;
551                 }
552
553                 if (strcasecmp(key, "MODE") == 0) {
554                         rule->mode = strtol(value, NULL, 8);
555                         rule->mode_operation = operation;
556                         valid = 1;
557                         continue;
558                 }
559
560                 if (strcasecmp(key, "OPTIONS") == 0) {
561                         if (strstr(value, "last_rule") != NULL) {
562                                 dbg("last rule to be applied");
563                                 rule->last_rule = 1;
564                         }
565                         if (strstr(value, "ignore_device") != NULL) {
566                                 dbg("device should be ignored");
567                                 rule->ignore_device = 1;
568                         }
569                         if (strstr(value, "ignore_remove") != NULL) {
570                                 dbg("remove event should be ignored");
571                                 rule->ignore_remove = 1;
572                         }
573                         if (strstr(value, "all_partitions") != NULL) {
574                                 dbg("creation of partition nodes requested");
575                                 rule->partitions = DEFAULT_PARTITIONS_COUNT;
576                         }
577                         valid = 1;
578                         continue;
579                 }
580
581                 err("unknown key '%s' in %s:%u", key, filename, lineno);
582         }
583
584         if (physdev && rule->wait_for_sysfs.operation == KEY_OP_UNSET)
585                 err("PHYSDEV* values are deprecated and will be removed from a future kernel, "
586                     "please fix it in %s:%u", filename, lineno);
587
588         /* skip line if not any valid key was found */
589         if (!valid)
590                 goto invalid;
591
592         /* grow buffer and add rule */
593         rule_size = sizeof(struct udev_rule) + rule->bufsize;
594         padding = (sizeof(size_t) - rule_size % sizeof(size_t)) % sizeof(size_t);
595         dbg("add %zi padding bytes", padding);
596         rule_size += padding;
597         rule->bufsize += padding;
598
599         rules->buf = realloc(rules->buf, rules->bufsize + rule_size);
600         if (!rules->buf) {
601                 err("realloc failed");
602                 goto exit;
603         }
604         dbg("adding rule to offset %zi", rules->bufsize);
605         memcpy(rules->buf + rules->bufsize, rule, rule_size);
606         rules->bufsize += rule_size;
607 exit:
608         free(rule);
609         return 0;
610
611 invalid:
612         free(rule);
613         err("invalid rule '%s:%u'", filename, lineno);
614         return -1;
615 }
616
617 static int parse_file(struct udev_rules *rules, const char *filename)
618 {
619         char line[LINE_SIZE];
620         char *bufline;
621         unsigned int lineno;
622         char *buf;
623         size_t bufsize;
624         size_t cur;
625         size_t count;
626         int retval = 0;
627
628         if (file_map(filename, &buf, &bufsize) != 0) {
629                 err("can't open '%s' as rules file: %s", filename, strerror(errno));
630                 return -1;
631         }
632         info("reading '%s' as rules file", filename);
633
634         /* loop through the whole file */
635         cur = 0;
636         lineno = 0;
637         while (cur < bufsize) {
638                 unsigned int i, j;
639
640                 count = buf_get_line(buf, bufsize, cur);
641                 bufline = &buf[cur];
642                 cur += count+1;
643                 lineno++;
644
645                 /* eat the whitespace */
646                 while ((count > 0) && isspace(bufline[0])) {
647                         bufline++;
648                         count--;
649                 }
650                 if (count == 0)
651                         continue;
652
653                 /* see if this is a comment */
654                 if (bufline[0] == COMMENT_CHARACTER)
655                         continue;
656
657                 if (count >= sizeof(line)) {
658                         err("line too long, rule skipped '%s:%u'", filename, lineno);
659                         continue;
660                 }
661
662                 /* skip backslash and newline from multiline rules */
663                 for (i = j = 0; i < count; i++) {
664                         if (bufline[i] == '\\' && bufline[i+1] == '\n')
665                                 continue;
666
667                         line[j++] = bufline[i];
668                 }
669                 line[j] = '\0';
670
671                 dbg("read '%s'", line);
672                 add_to_rules(rules, line, filename, lineno);
673         }
674
675         file_unmap(buf, bufsize);
676         return retval;
677 }
678
679 int udev_rules_init(struct udev_rules *rules, int resolve_names)
680 {
681         struct stat stats;
682         int retval;
683
684         memset(rules, 0x00, sizeof(struct udev_rules));
685         rules->resolve_names = resolve_names;
686
687         /* parse rules file or all matching files in directory */
688         if (stat(udev_rules_dir, &stats) != 0)
689                 return -1;
690
691         if ((stats.st_mode & S_IFMT) != S_IFDIR) {
692                 dbg("parse single rules file '%s'", udev_rules_dir);
693                 retval = parse_file(rules, udev_rules_dir);
694         } else {
695                 struct name_entry *name_loop, *name_tmp;
696                 LIST_HEAD(name_list);
697
698                 dbg("parse rules directory '%s'", udev_rules_dir);
699                 retval = add_matching_files(&name_list, udev_rules_dir, RULESFILE_SUFFIX);
700
701                 list_for_each_entry_safe(name_loop, name_tmp, &name_list, node) {
702                         if (stat(name_loop->name, &stats) == 0) {
703                                 if (stats.st_size)
704                                         parse_file(rules, name_loop->name);
705                                 else
706                                         dbg("empty rules file '%s'", name_loop->name);
707                         } else
708                                 err("could not read '%s': %s", name_loop->name, strerror(errno));
709                         list_del(&name_loop->node);
710                         free(name_loop);
711                 }
712         }
713
714         return retval;
715 }
716
717 void udev_rules_cleanup(struct udev_rules *rules)
718 {
719         if (rules->buf) {
720                 free(rules->buf);
721                 rules->buf = NULL;
722         }
723 }