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_libc_wrapper.h"
  32 #include "udev.h"
  33 #include "udev_utils.h"
  34 #include "logging.h"
  35 #include "udev_rules.h"
  36
  37
  38 void udev_rules_iter_init(struct udev_rules *rules)
  39 {
  40         dbg("bufsize=%zi", rules->bufsize);
  41         rules->current = 0;
  42 }
  43
  44 struct udev_rule *udev_rules_iter_next(struct udev_rules *rules)
  45 {
  46         static struct udev_rule *rule;
  47
  48         if (!rules)
  49                 return NULL;
  50
  51         dbg("current=%zi", rules->current);
  52         if (rules->current >= rules->bufsize) {
  53                 dbg("no more rules");
  54                 return NULL;
  55         }
  56
  57         /* get next rule */
  58         rule = (struct udev_rule *) (rules->buf + rules->current);
  59         rules->current += sizeof(struct udev_rule) + rule->bufsize;
  60
  61         return rule;
  62 }
  63
  64 struct udev_rule *udev_rules_iter_label(struct udev_rules *rules, const char *label)
  65 {
  66         static struct udev_rule *rule;
  67
  68 next:
  69         dbg("current=%zi", rules->current);
  70         if (rules->current >= rules->bufsize) {
  71                 dbg("no more rules");
  72                 return NULL;
  73         }
  74         rule = (struct udev_rule *) (rules->buf + rules->current);
  75
  76         if (strcmp(&rule->buf[rule->label.val_off], label) != 0) {
  77                 dbg("moving forward, looking for label '%s'", label);
  78                 rules->current += sizeof(struct udev_rule) + rule->bufsize;
  79                 goto next;
  80         }
  81
  82         dbg("found label '%s'", label);
  83         return rule;
  84 }
  85
  86 static int get_key(char **line, char **key, enum key_operation *operation, char **value)
  87 {
  88         char *linepos;
  89         char *temp;
  90
  91         linepos = *line;
  92         if (!linepos)
  93                 return -1;
  94
  95         /* skip whitespace */
  96         while (isspace(linepos[0]) || linepos[0] == ',')
  97                 linepos++;
  98
  99         /* get the key */
 100         *key = linepos;
 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
 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
 156         /* get the value*/
 157         if (linepos[0] == '"')
 158                 linepos++;
 159         else
 160                 return -1;
 161         *value = linepos;
 162
 163         temp = strchr(linepos, '"');
 164         if (!temp)
 165                 return -1;
 166         temp[0] = '\0';
 167         temp++;
 168         dbg("value='%s'", *value);
 169
 170         /* move line to next key */
 171         *line = temp;
 172
 173         return 0;
 174 }
 175
 176 /* extract possible KEY{attr} */
 177 static char *get_key_attribute(char *str)
 178 {
 179         char *pos;
 180         char *attr;
 181
 182         attr = strchr(str, '{');
 183         if (attr != NULL) {
 184                 attr++;
 185                 pos = strchr(attr, '}');
 186                 if (pos == NULL) {
 187                         err("missing closing brace for format");
 188                         return NULL;
 189                 }
 190                 pos[0] = '\0';
 191                 dbg("attribute='%s'", attr);
 192                 return attr;
 193         }
 194
 195         return NULL;
 196 }
 197
 198 static int add_rule_key(struct udev_rule *rule, struct key *key,
 199                         enum key_operation operation, const char *value)
 200 {
 201         size_t val_len = strnlen(value, PATH_SIZE);
 202
 203         key->operation = operation;
 204
 205         key->val_off = rule->bufsize;
 206         strlcpy(rule->buf + rule->bufsize, value, val_len+1);
 207         rule->bufsize += val_len+1;
 208
 209         return 0;
 210 }
 211
 212 static int add_rule_key_pair(struct udev_rule *rule, struct key_pairs *pairs,
 213                              enum key_operation operation, const char *key, const char *value)
 214 {
 215         size_t key_len = strnlen(key, PATH_SIZE);
 216
 217         if (pairs->count >= PAIRS_MAX) {
 218                 err("skip, too many keys in a single rule");
 219                 return -1;
 220         }
 221
 222         add_rule_key(rule, &pairs->keys[pairs->count].key, operation, value);
 223
 224         /* add the key-name of the pair */
 225         pairs->keys[pairs->count].key_name_off = rule->bufsize;
 226         strlcpy(rule->buf + rule->bufsize, key, key_len+1);
 227         rule->bufsize += key_len+1;
 228
 229         pairs->count++;
 230
 231         return 0;
 232 }
 233
 234 static int add_to_rules(struct udev_rules *rules, char *line)
 235 {
 236         struct udev_rule *rule;
 237         size_t rule_size;
 238         int valid;
 239         char *linepos;
 240         char *attr;
 241         size_t padding;
 242         int retval;
 243
 244         /* get all the keys */
 245         rule = calloc(1, sizeof (struct udev_rule) + LINE_SIZE);
 246         if (!rule) {
 247                 err("malloc failed");
 248                 return -1;
 249         }
 250         linepos = line;
 251         valid = 0;
 252
 253         while (1) {
 254                 char *key;
 255                 char *value;
 256                 enum key_operation operation = KEY_OP_UNSET;
 257
 258                 retval = get_key(&linepos, &key, &operation, &value);
 259                 if (retval)
 260                         break;
 261
 262                 if (strcasecmp(key, "LABEL") == 0) {
 263                         add_rule_key(rule, &rule->label, operation, value);
 264                         valid = 1;
 265                         continue;
 266                 }
 267
 268                 if (strcasecmp(key, "GOTO") == 0) {
 269                         add_rule_key(rule, &rule->goto_label, operation, value);
 270                         valid = 1;
 271                         continue;
 272                 }
 273
 274                 if (strcasecmp(key, "KERNEL") == 0) {
 275                         add_rule_key(rule, &rule->kernel_name, operation, value);
 276                         valid = 1;
 277                         continue;
 278                 }
 279
 280                 if (strcasecmp(key, "SUBSYSTEM") == 0) {
 281                         add_rule_key(rule, &rule->subsystem, operation, value);
 282                         valid = 1;
 283                         continue;
 284                 }
 285
 286                 if (strcasecmp(key, "ACTION") == 0) {
 287                         add_rule_key(rule, &rule->action, operation, value);
 288                         valid = 1;
 289                         continue;
 290                 }
 291
 292                 if (strcasecmp(key, "DEVPATH") == 0) {
 293                         add_rule_key(rule, &rule->devpath, operation, value);
 294                         valid = 1;
 295                         continue;
 296                 }
 297
 298                 if (strcasecmp(key, "BUS") == 0) {
 299                         add_rule_key(rule, &rule->bus, operation, value);
 300                         valid = 1;
 301                         continue;
 302                 }
 303
 304                 if (strcasecmp(key, "ID") == 0) {
 305                         add_rule_key(rule, &rule->id, operation, value);
 306                         valid = 1;
 307                         continue;
 308                 }
 309
 310                 if (strncasecmp(key, "SYSFS", sizeof("SYSFS")-1) == 0) {
 311                         attr = get_key_attribute(key + sizeof("SYSFS")-1);
 312                         if (attr == NULL) {
 313                                 err("error parsing SYSFS attribute in '%s'", line);
 314                                 continue;
 315                         }
 316                         add_rule_key_pair(rule, &rule->sysfs, operation, attr, value);
 317                         valid = 1;
 318                         continue;
 319                 }
 320
 321                 if (strcasecmp(key, "WAIT_FOR_SYSFS") == 0) {
 322                         add_rule_key(rule, &rule->wait_for_sysfs, operation, value);
 323                         valid = 1;
 324                         continue;
 325                 }
 326
 327                 if (strncasecmp(key, "ENV", sizeof("ENV")-1) == 0) {
 328                         attr = get_key_attribute(key + sizeof("ENV")-1);
 329                         if (attr == NULL) {
 330                                 err("error parsing ENV attribute");
 331                                 continue;
 332                         }
 333                         add_rule_key_pair(rule, &rule->env, operation, attr, value);
 334                         valid = 1;
 335                         continue;
 336                 }
 337
 338                 if (strcasecmp(key, "MODALIAS") == 0) {
 339                         add_rule_key(rule, &rule->modalias, operation, value);
 340                         valid = 1;
 341                         continue;
 342                 }
 343
 344                 if (strncasecmp(key, "IMPORT", sizeof("IMPORT")-1) == 0) {
 345                         attr = get_key_attribute(key + sizeof("IMPORT")-1);
 346                         if (attr && strstr(attr, "program")) {
 347                                 dbg("IMPORT will be executed");
 348                                 rule->import_type  = IMPORT_PROGRAM;
 349                         } else if (attr && strstr(attr, "file")) {
 350                                 dbg("IMPORT will be included as file");
 351                                 rule->import_type  = IMPORT_FILE;
 352                         } else if (attr && strstr(attr, "parent")) {
 353                                 dbg("IMPORT will include the parent values");
 354                                 rule->import_type = IMPORT_PARENT;
 355                         } else {
 356                                 /* figure it out if it is executable */
 357                                 char file[PATH_SIZE];
 358                                 char *pos;
 359                                 struct stat stats;
 360
 361                                 strlcpy(file, value, sizeof(file));
 362                                 pos = strchr(file, ' ');
 363                                 if (pos)
 364                                         pos[0] = '\0';
 365                                 dbg("IMPORT auto mode for '%s'", file);
 366                                 if (!lstat(file, &stats) && (stats.st_mode & S_IXUSR)) {
 367                                         dbg("IMPORT is executable, will be executed (autotype)");
 368                                         rule->import_type  = IMPORT_PROGRAM;
 369                                 } else {
 370                                         dbg("IMPORT is not executable, will be included as file (autotype)");
 371                                         rule->import_type  = IMPORT_FILE;
 372                                 }
 373                         }
 374                         add_rule_key(rule, &rule->import, operation, value);
 375                         valid = 1;
 376                         continue;
 377                 }
 378
 379                 if (strcasecmp(key, "DRIVER") == 0) {
 380                         add_rule_key(rule, &rule->driver, operation, value);
 381                         valid = 1;
 382                         continue;
 383                 }
 384
 385                 if (strcasecmp(key, "RESULT") == 0) {
 386                         add_rule_key(rule, &rule->result, operation, value);
 387                         valid = 1;
 388                         continue;
 389                 }
 390
 391                 if (strcasecmp(key, "PROGRAM") == 0) {
 392                         add_rule_key(rule, &rule->program, operation, value);
 393                         valid = 1;
 394                         continue;
 395                 }
 396
 397                 if (strncasecmp(key, "NAME", sizeof("NAME")-1) == 0) {
 398                         attr = get_key_attribute(key + sizeof("NAME")-1);
 399                         if (attr != NULL) {
 400                                 if (strstr(attr, "all_partitions") != NULL) {
 401                                         dbg("creation of partition nodes requested");
 402                                         rule->partitions = DEFAULT_PARTITIONS_COUNT;
 403                                 }
 404                                 if (strstr(attr, "ignore_remove") != NULL) {
 405                                         dbg("remove event should be ignored");
 406                                         rule->ignore_remove = 1;
 407                                 }
 408                         }
 409                         if (value[0] == '\0') {
 410                                 dbg("name empty device should be ignored");
 411                                 rule->name.operation = operation;
 412                                 rule->ignore_device = 1;
 413                         } else
 414                                 add_rule_key(rule, &rule->name, operation, value);
 415                         continue;
 416                 }
 417
 418                 if (strcasecmp(key, "SYMLINK") == 0) {
 419                         add_rule_key(rule, &rule->symlink, operation, value);
 420                         valid = 1;
 421                         continue;
 422                 }
 423
 424                 if (strcasecmp(key, "OWNER") == 0) {
 425                         valid = 1;
 426                         if (rules->resolve_names && (!strchr(value, '$') && !strchr(value, '%'))) {
 427                                 char *endptr;
 428                                 strtoul(value, &endptr, 10);
 429                                 if (endptr[0] != '\0') {
 430                                         char owner[32];
 431                                         uid_t uid = lookup_user(value);
 432                                         dbg("replacing username='%s' by id=%i", value, uid);
 433                                         sprintf(owner, "%li", uid);
 434                                         add_rule_key(rule, &rule->owner, operation, owner);
 435                                         continue;
 436                                 }
 437                         }
 438
 439                         add_rule_key(rule, &rule->owner, operation, value);
 440                         continue;
 441                 }
 442
 443                 if (strcasecmp(key, "GROUP") == 0) {
 444                         valid = 1;
 445                         if (rules->resolve_names && (!strchr(value, '$') && !strchr(value, '%'))) {
 446                                 char *endptr;
 447                                 strtoul(value, &endptr, 10);
 448                                 if (endptr[0] != '\0') {
 449                                         char group[32];
 450                                         gid_t gid = lookup_group(value);
 451                                         dbg("replacing groupname='%s' by id=%i", value, gid);
 452                                         sprintf(group, "%li", gid);
 453                                         add_rule_key(rule, &rule->group, operation, group);
 454                                         continue;
 455                                 }
 456                         }
 457
 458                         add_rule_key(rule, &rule->group, operation, value);
 459                         continue;
 460                 }
 461
 462                 if (strcasecmp(key, "MODE") == 0) {
 463                         rule->mode = strtol(value, NULL, 8);
 464                         rule->mode_operation = operation;
 465                         valid = 1;
 466                         continue;
 467                 }
 468
 469                 if (strcasecmp(key, "RUN") == 0) {
 470                         add_rule_key(rule, &rule->run, operation, value);
 471                         valid = 1;
 472                         continue;
 473                 }
 474
 475                 if (strcasecmp(key, "OPTIONS") == 0) {
 476                         if (strstr(value, "last_rule") != NULL) {
 477                                 dbg("last rule to be applied");
 478                                 rule->last_rule = 1;
 479                         }
 480                         if (strstr(value, "ignore_device") != NULL) {
 481                                 dbg("device should be ignored");
 482                                 rule->ignore_device = 1;
 483                         }
 484                         if (strstr(value, "ignore_remove") != NULL) {
 485                                 dbg("remove event should be ignored");
 486                                 rule->ignore_remove = 1;
 487                         }
 488                         if (strstr(value, "all_partitions") != NULL) {
 489                                 dbg("creation of partition nodes requested");
 490                                 rule->partitions = DEFAULT_PARTITIONS_COUNT;
 491                         }
 492                         valid = 1;
 493                         continue;
 494                 }
 495
 496                 err("unknown key '%s', in '%s'", key, line);
 497         }
 498
 499         /* skip line if not any valid key was found */
 500         if (!valid) {
 501                 err("invalid rule '%s'", line);
 502                 goto exit;
 503         }
 504
 505         /* grow buffer and add rule */
 506         rule_size = sizeof(struct udev_rule) + rule->bufsize;
 507         padding = (sizeof(size_t) - rule_size % sizeof(size_t)) % sizeof(size_t);
 508         dbg("add %zi padding bytes", padding);
 509         rule_size += padding;
 510         rule->bufsize += padding;
 511
 512         rules->buf = realloc(rules->buf, rules->bufsize + rule_size);
 513         if (!rules->buf) {
 514                 err("realloc failed");
 515                 goto exit;
 516         }
 517         dbg("adding rule to offset %zi", rules->bufsize);
 518         memcpy(rules->buf + rules->bufsize, rule, rule_size);
 519         rules->bufsize += rule_size;
 520 exit:
 521         free(rule);
 522         return 0;
 523 }
 524
 525 static int parse_file(struct udev_rules *rules, const char *filename)
 526 {
 527         char line[LINE_SIZE];
 528         char *bufline;
 529         int lineno;
 530         char *buf;
 531         size_t bufsize;
 532         size_t cur;
 533         size_t count;
 534         int retval = 0;
 535
 536         if (file_map(filename, &buf, &bufsize) != 0) {
 537                 err("can't open '%s' as rules file", filename);
 538                 return -1;
 539         }
 540         dbg("reading '%s' as rules file", filename);
 541
 542         /* loop through the whole file */
 543         cur = 0;
 544         lineno = 0;
 545         while (cur < bufsize) {
 546                 unsigned int i, j;
 547
 548                 count = buf_get_line(buf, bufsize, cur);
 549                 bufline = &buf[cur];
 550                 cur += count+1;
 551                 lineno++;
 552
 553                 if (count >= sizeof(line)) {
 554                         info("line too long, rule skipped %s, line %d", filename, lineno);
 555                         continue;
 556                 }
 557
 558                 /* eat the whitespace */
 559                 while ((count > 0) && isspace(bufline[0])) {
 560                         bufline++;
 561                         count--;
 562                 }
 563                 if (count == 0)
 564                         continue;
 565
 566                 /* see if this is a comment */
 567                 if (bufline[0] == COMMENT_CHARACTER)
 568                         continue;
 569
 570                 /* skip backslash and newline from multi line rules */
 571                 for (i = j = 0; i < count; i++) {
 572                         if (bufline[i] == '\\' && bufline[i+1] == '\n')
 573                                 continue;
 574
 575                         line[j++] = bufline[i];
 576                 }
 577                 line[j] = '\0';
 578
 579                 dbg("read '%s'", line);
 580                 add_to_rules(rules, line);
 581         }
 582
 583         file_unmap(buf, bufsize);
 584         return retval;
 585 }
 586
 587 static int rules_map(struct udev_rules *rules, const char *filename)
 588 {
 589         if (file_map(filename, &rules->buf, &rules->bufsize)) {
 590                 rules->buf = NULL;
 591                 return -1;
 592         }
 593         if (rules->bufsize == 0) {
 594                 file_unmap(rules->buf, rules->bufsize);
 595                 rules->buf = NULL;
 596                 return -1;
 597         }
 598         rules->mapped = 1;
 599
 600         return 0;
 601 }
 602
 603 int udev_rules_init(struct udev_rules *rules, int resolve_names)
 604 {
 605         char comp[PATH_SIZE];
 606         struct stat stats;
 607         int retval;
 608
 609         memset(rules, 0x00, sizeof(struct udev_rules));
 610         rules->resolve_names = resolve_names;
 611
 612         /* check for precompiled rules */
 613         strlcpy(comp, udev_rules_filename, sizeof(comp));
 614         strlcat(comp, ".compiled", sizeof(comp));
 615         if (stat(comp, &stats) == 0) {
 616                 dbg("map compiled rules '%s'", comp);
 617                 if (rules_map(rules, comp) == 0)
 618                         return 0;
 619         }
 620
 621         if (stat(udev_rules_filename, &stats) != 0)
 622                 return -1;
 623
 624         if ((stats.st_mode & S_IFMT) != S_IFDIR) {
 625                 dbg("parse single rules file '%s'", udev_rules_filename);
 626                 retval = parse_file(rules, udev_rules_filename);
 627         } else {
 628                 struct name_entry *name_loop, *name_tmp;
 629                 LIST_HEAD(name_list);
 630
 631                 dbg("parse rules directory '%s'", udev_rules_filename);
 632                 retval = add_matching_files(&name_list, udev_rules_filename, RULEFILE_SUFFIX);
 633
 634                 list_for_each_entry_safe(name_loop, name_tmp, &name_list, node) {
 635                         parse_file(rules, name_loop->name);
 636                         list_del(&name_loop->node);
 637                 }
 638         }
 639
 640         return retval;
 641 }
 642
 643 void udev_rules_close(struct udev_rules *rules)
 644 {
 645         if (rules->mapped)
 646                 file_unmap(rules->buf, rules->bufsize);
 647         else
 648                 free(rules->buf);
 649
 650         rules->buf = NULL;
 651 }