udev_rules_parse.c

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