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 == NULL && linepos[0] == '\0')
  93                 return -1;
  94
  95         /* skip whitespace */
  96         while (isspace(linepos[0]) || linepos[0] == ',')
  97                 linepos++;
  98
  99         /* get the key */
 100         if (linepos[0] == '\0')
 101                 return -1;
 102         *key = linepos;
 103
 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         if (linepos[0] == '\0')
 127                 return -1;
 128
 129         /* get operation type */
 130         if (linepos[0] == '=' && linepos[1] == '=') {
 131                 *operation = KEY_OP_MATCH;
 132                 linepos += 2;
 133                 dbg("operator=match");
 134         } else if (linepos[0] == '!' && linepos[1] == '=') {
 135                 *operation = KEY_OP_NOMATCH;
 136                 linepos += 2;
 137                 dbg("operator=nomatch");
 138         } else if (linepos[0] == '+' && linepos[1] == '=') {
 139                 *operation = KEY_OP_ADD;
 140                 linepos += 2;
 141                 dbg("operator=add");
 142         } else if (linepos[0] == '=') {
 143                 *operation = KEY_OP_ASSIGN;
 144                 linepos++;
 145                 dbg("operator=assign");
 146         } else if (linepos[0] == ':' && linepos[1] == '=') {
 147                 *operation = KEY_OP_ASSIGN_FINAL;
 148                 linepos += 2;
 149                 dbg("operator=assign_final");
 150         } else
 151                 return -1;
 152
 153         /* terminate key */
 154         temp[0] = '\0';
 155         dbg("key='%s'", *key);
 156
 157         /* skip whitespace after operator */
 158         while (isspace(linepos[0]))
 159                 linepos++;
 160         if (linepos[0] == '\0')
 161                 return -1;
 162
 163         /* get the value*/
 164         if (linepos[0] == '"')
 165                 linepos++;
 166         else
 167                 return -1;
 168         *value = linepos;
 169
 170         temp = strchr(linepos, '"');
 171         if (!temp)
 172                 return -1;
 173         temp[0] = '\0';
 174         temp++;
 175         dbg("value='%s'", *value);
 176
 177         /* move line to next key */
 178         *line = temp;
 179
 180         return 0;
 181 }
 182
 183 /* extract possible KEY{attr} */
 184 static char *get_key_attribute(char *str)
 185 {
 186         char *pos;
 187         char *attr;
 188
 189         attr = strchr(str, '{');
 190         if (attr != NULL) {
 191                 attr++;
 192                 pos = strchr(attr, '}');
 193                 if (pos == NULL) {
 194                         err("missing closing brace for format");
 195                         return NULL;
 196                 }
 197                 pos[0] = '\0';
 198                 dbg("attribute='%s'", attr);
 199                 return attr;
 200         }
 201
 202         return NULL;
 203 }
 204
 205 static int add_rule_key(struct udev_rule *rule, struct key *key,
 206                         enum key_operation operation, const char *value)
 207 {
 208         size_t val_len = strnlen(value, PATH_SIZE);
 209
 210         key->operation = operation;
 211
 212         key->val_off = rule->bufsize;
 213         strlcpy(rule->buf + rule->bufsize, value, val_len+1);
 214         rule->bufsize += val_len+1;
 215
 216         return 0;
 217 }
 218
 219 static int add_rule_key_pair(struct udev_rule *rule, struct key_pairs *pairs,
 220                              enum key_operation operation, const char *key, const char *value)
 221 {
 222         size_t key_len = strnlen(key, PATH_SIZE);
 223
 224         if (pairs->count >= PAIRS_MAX) {
 225                 err("skip, too many keys in a single rule");
 226                 return -1;
 227         }
 228
 229         add_rule_key(rule, &pairs->keys[pairs->count].key, operation, value);
 230
 231         /* add the key-name of the pair */
 232         pairs->keys[pairs->count].key_name_off = rule->bufsize;
 233         strlcpy(rule->buf + rule->bufsize, key, key_len+1);
 234         rule->bufsize += key_len+1;
 235
 236         pairs->count++;
 237
 238         return 0;
 239 }
 240
 241 static int add_to_rules(struct udev_rules *rules, char *line)
 242 {
 243         struct udev_rule *rule;
 244         size_t rule_size;
 245         int valid;
 246         char *linepos;
 247         char *attr;
 248         size_t padding;
 249         int retval;
 250
 251         /* get all the keys */
 252         rule = calloc(1, sizeof (struct udev_rule) + LINE_SIZE);
 253         if (!rule) {
 254                 err("malloc failed");
 255                 return -1;
 256         }
 257         linepos = line;
 258         valid = 0;
 259
 260         while (1) {
 261                 char *key;
 262                 char *value;
 263                 enum key_operation operation = KEY_OP_UNSET;
 264
 265                 retval = get_key(&linepos, &key, &operation, &value);
 266                 if (retval)
 267                         break;
 268
 269                 if (strcasecmp(key, "LABEL") == 0) {
 270                         add_rule_key(rule, &rule->label, operation, value);
 271                         valid = 1;
 272                         continue;
 273                 }
 274
 275                 if (strcasecmp(key, "GOTO") == 0) {
 276                         add_rule_key(rule, &rule->goto_label, operation, value);
 277                         valid = 1;
 278                         continue;
 279                 }
 280
 281                 if (strcasecmp(key, "KERNEL") == 0) {
 282                         add_rule_key(rule, &rule->kernel_name, operation, value);
 283                         valid = 1;
 284                         continue;
 285                 }
 286
 287                 if (strcasecmp(key, "SUBSYSTEM") == 0) {
 288                         add_rule_key(rule, &rule->subsystem, operation, value);
 289                         valid = 1;
 290                         continue;
 291                 }
 292
 293                 if (strcasecmp(key, "ACTION") == 0) {
 294                         add_rule_key(rule, &rule->action, operation, value);
 295                         valid = 1;
 296                         continue;
 297                 }
 298
 299                 if (strcasecmp(key, "DEVPATH") == 0) {
 300                         add_rule_key(rule, &rule->devpath, operation, value);
 301                         valid = 1;
 302                         continue;
 303                 }
 304
 305                 if (strcasecmp(key, "BUS") == 0) {
 306                         add_rule_key(rule, &rule->bus, operation, value);
 307                         valid = 1;
 308                         continue;
 309                 }
 310
 311                 if (strcasecmp(key, "ID") == 0) {
 312                         add_rule_key(rule, &rule->id, operation, value);
 313                         valid = 1;
 314                         continue;
 315                 }
 316
 317                 if (strncasecmp(key, "SYSFS", sizeof("SYSFS")-1) == 0) {
 318                         attr = get_key_attribute(key + sizeof("SYSFS")-1);
 319                         if (attr == NULL) {
 320                                 err("error parsing SYSFS attribute in '%s'", line);
 321                                 continue;
 322                         }
 323                         add_rule_key_pair(rule, &rule->sysfs, operation, attr, value);
 324                         valid = 1;
 325                         continue;
 326                 }
 327
 328                 if (strcasecmp(key, "WAIT_FOR_SYSFS") == 0) {
 329                         add_rule_key(rule, &rule->wait_for_sysfs, operation, value);
 330                         valid = 1;
 331                         continue;
 332                 }
 333
 334                 if (strncasecmp(key, "ENV", sizeof("ENV")-1) == 0) {
 335                         attr = get_key_attribute(key + sizeof("ENV")-1);
 336                         if (attr == NULL) {
 337                                 err("error parsing ENV attribute");
 338                                 continue;
 339                         }
 340                         add_rule_key_pair(rule, &rule->env, operation, attr, value);
 341                         valid = 1;
 342                         continue;
 343                 }
 344
 345                 if (strcasecmp(key, "MODALIAS") == 0) {
 346                         add_rule_key(rule, &rule->modalias, operation, value);
 347                         valid = 1;
 348                         continue;
 349                 }
 350
 351                 if (strncasecmp(key, "IMPORT", sizeof("IMPORT")-1) == 0) {
 352                         attr = get_key_attribute(key + sizeof("IMPORT")-1);
 353                         if (attr && strstr(attr, "program")) {
 354                                 dbg("IMPORT will be executed");
 355                                 rule->import_type  = IMPORT_PROGRAM;
 356                         } else if (attr && strstr(attr, "file")) {
 357                                 dbg("IMPORT will be included as file");
 358                                 rule->import_type  = IMPORT_FILE;
 359                         } else if (attr && strstr(attr, "parent")) {
 360                                 dbg("IMPORT will include the parent values");
 361                                 rule->import_type = IMPORT_PARENT;
 362                         } else {
 363                                 /* figure it out if it is executable */
 364                                 char file[PATH_SIZE];
 365                                 char *pos;
 366                                 struct stat stats;
 367
 368                                 strlcpy(file, value, sizeof(file));
 369                                 pos = strchr(file, ' ');
 370                                 if (pos)
 371                                         pos[0] = '\0';
 372                                 dbg("IMPORT auto mode for '%s'", file);
 373                                 if (!lstat(file, &stats) && (stats.st_mode & S_IXUSR)) {
 374                                         dbg("IMPORT is executable, will be executed (autotype)");
 375                                         rule->import_type  = IMPORT_PROGRAM;
 376                                 } else {
 377                                         dbg("IMPORT is not executable, will be included as file (autotype)");
 378                                         rule->import_type  = IMPORT_FILE;
 379                                 }
 380                         }
 381                         add_rule_key(rule, &rule->import, operation, value);
 382                         valid = 1;
 383                         continue;
 384                 }
 385
 386                 if (strcasecmp(key, "DRIVER") == 0) {
 387                         add_rule_key(rule, &rule->driver, operation, value);
 388                         valid = 1;
 389                         continue;
 390                 }
 391
 392                 if (strcasecmp(key, "RESULT") == 0) {
 393                         add_rule_key(rule, &rule->result, operation, value);
 394                         valid = 1;
 395                         continue;
 396                 }
 397
 398                 if (strcasecmp(key, "PROGRAM") == 0) {
 399                         add_rule_key(rule, &rule->program, operation, value);
 400                         valid = 1;
 401                         continue;
 402                 }
 403
 404                 if (strncasecmp(key, "NAME", sizeof("NAME")-1) == 0) {
 405                         attr = get_key_attribute(key + sizeof("NAME")-1);
 406                         if (attr != NULL) {
 407                                 if (strstr(attr, "all_partitions") != NULL) {
 408                                         dbg("creation of partition nodes requested");
 409                                         rule->partitions = DEFAULT_PARTITIONS_COUNT;
 410                                 }
 411                                 if (strstr(attr, "ignore_remove") != NULL) {
 412                                         dbg("remove event should be ignored");
 413                                         rule->ignore_remove = 1;
 414                                 }
 415                         }
 416                         if (value[0] == '\0') {
 417                                 dbg("name empty device should be ignored");
 418                                 rule->name.operation = operation;
 419                                 rule->ignore_device = 1;
 420                         } else
 421                                 add_rule_key(rule, &rule->name, operation, value);
 422                         continue;
 423                 }
 424
 425                 if (strcasecmp(key, "SYMLINK") == 0) {
 426                         add_rule_key(rule, &rule->symlink, operation, value);
 427                         valid = 1;
 428                         continue;
 429                 }
 430
 431                 if (strcasecmp(key, "OWNER") == 0) {
 432                         valid = 1;
 433                         if (rules->resolve_names && (!strchr(value, '$') && !strchr(value, '%'))) {
 434                                 char *endptr;
 435                                 strtoul(value, &endptr, 10);
 436                                 if (endptr[0] != '\0') {
 437                                         char owner[32];
 438                                         uid_t uid = lookup_user(value);
 439                                         dbg("replacing username='%s' by id=%i", value, uid);
 440                                         sprintf(owner, "%li", uid);
 441                                         add_rule_key(rule, &rule->owner, operation, owner);
 442                                         continue;
 443                                 }
 444                         }
 445
 446                         add_rule_key(rule, &rule->owner, operation, value);
 447                         continue;
 448                 }
 449
 450                 if (strcasecmp(key, "GROUP") == 0) {
 451                         valid = 1;
 452                         if (rules->resolve_names && (!strchr(value, '$') && !strchr(value, '%'))) {
 453                                 char *endptr;
 454                                 strtoul(value, &endptr, 10);
 455                                 if (endptr[0] != '\0') {
 456                                         char group[32];
 457                                         gid_t gid = lookup_group(value);
 458                                         dbg("replacing groupname='%s' by id=%i", value, gid);
 459                                         sprintf(group, "%li", gid);
 460                                         add_rule_key(rule, &rule->group, operation, group);
 461                                         continue;
 462                                 }
 463                         }
 464
 465                         add_rule_key(rule, &rule->group, operation, value);
 466                         continue;
 467                 }
 468
 469                 if (strcasecmp(key, "MODE") == 0) {
 470                         rule->mode = strtol(value, NULL, 8);
 471                         rule->mode_operation = operation;
 472                         valid = 1;
 473                         continue;
 474                 }
 475
 476                 if (strcasecmp(key, "RUN") == 0) {
 477                         add_rule_key(rule, &rule->run, operation, value);
 478                         valid = 1;
 479                         continue;
 480                 }
 481
 482                 if (strcasecmp(key, "OPTIONS") == 0) {
 483                         if (strstr(value, "last_rule") != NULL) {
 484                                 dbg("last rule to be applied");
 485                                 rule->last_rule = 1;
 486                         }
 487                         if (strstr(value, "ignore_device") != NULL) {
 488                                 dbg("device should be ignored");
 489                                 rule->ignore_device = 1;
 490                         }
 491                         if (strstr(value, "ignore_remove") != NULL) {
 492                                 dbg("remove event should be ignored");
 493                                 rule->ignore_remove = 1;
 494                         }
 495                         if (strstr(value, "all_partitions") != NULL) {
 496                                 dbg("creation of partition nodes requested");
 497                                 rule->partitions = DEFAULT_PARTITIONS_COUNT;
 498                         }
 499                         valid = 1;
 500                         continue;
 501                 }
 502
 503                 err("unknown key '%s', in '%s'", key, line);
 504         }
 505
 506         /* skip line if not any valid key was found */
 507         if (!valid) {
 508                 err("invalid rule '%s'", line);
 509                 goto exit;
 510         }
 511
 512         /* grow buffer and add rule */
 513         rule_size = sizeof(struct udev_rule) + rule->bufsize;
 514         padding = (sizeof(size_t) - rule_size % sizeof(size_t)) % sizeof(size_t);
 515         dbg("add %zi padding bytes", padding);
 516         rule_size += padding;
 517         rule->bufsize += padding;
 518
 519         rules->buf = realloc(rules->buf, rules->bufsize + rule_size);
 520         if (!rules->buf) {
 521                 err("realloc failed");
 522                 goto exit;
 523         }
 524         dbg("adding rule to offset %zi", rules->bufsize);
 525         memcpy(rules->buf + rules->bufsize, rule, rule_size);
 526         rules->bufsize += rule_size;
 527 exit:
 528         free(rule);
 529         return 0;
 530 }
 531
 532 static int parse_file(struct udev_rules *rules, const char *filename)
 533 {
 534         char line[LINE_SIZE];
 535         char *bufline;
 536         int lineno;
 537         char *buf;
 538         size_t bufsize;
 539         size_t cur;
 540         size_t count;
 541         int retval = 0;
 542
 543         if (file_map(filename, &buf, &bufsize) != 0) {
 544                 err("can't open '%s' as rules file", filename);
 545                 return -1;
 546         }
 547         dbg("reading '%s' as rules file", filename);
 548
 549         /* loop through the whole file */
 550         cur = 0;
 551         lineno = 0;
 552         while (cur < bufsize) {
 553                 unsigned int i, j;
 554
 555                 count = buf_get_line(buf, bufsize, cur);
 556                 bufline = &buf[cur];
 557                 cur += count+1;
 558                 lineno++;
 559
 560                 if (count >= sizeof(line)) {
 561                         info("line too long, rule skipped %s, line %d", filename, lineno);
 562                         continue;
 563                 }
 564
 565                 /* eat the whitespace */
 566                 while ((count > 0) && isspace(bufline[0])) {
 567                         bufline++;
 568                         count--;
 569                 }
 570                 if (count == 0)
 571                         continue;
 572
 573                 /* see if this is a comment */
 574                 if (bufline[0] == COMMENT_CHARACTER)
 575                         continue;
 576
 577                 /* skip backslash and newline from multi line rules */
 578                 for (i = j = 0; i < count; i++) {
 579                         if (bufline[i] == '\\' && bufline[i+1] == '\n')
 580                                 continue;
 581
 582                         line[j++] = bufline[i];
 583                 }
 584                 line[j] = '\0';
 585
 586                 dbg("read '%s'", line);
 587                 add_to_rules(rules, line);
 588         }
 589
 590         file_unmap(buf, bufsize);
 591         return retval;
 592 }
 593
 594 static int rules_map(struct udev_rules *rules, const char *filename)
 595 {
 596         if (file_map(filename, &rules->buf, &rules->bufsize)) {
 597                 rules->buf = NULL;
 598                 return -1;
 599         }
 600         if (rules->bufsize == 0) {
 601                 file_unmap(rules->buf, rules->bufsize);
 602                 rules->buf = NULL;
 603                 return -1;
 604         }
 605         rules->mapped = 1;
 606
 607         return 0;
 608 }
 609
 610 int udev_rules_init(struct udev_rules *rules, int read_compiled, int resolve_names)
 611 {
 612         char comp[PATH_SIZE];
 613         struct stat stats;
 614         int retval;
 615
 616         memset(rules, 0x00, sizeof(struct udev_rules));
 617         rules->resolve_names = resolve_names;
 618
 619         /* check for precompiled rules */
 620         if (read_compiled) {
 621                 strlcpy(comp, udev_rules_filename, sizeof(comp));
 622                 strlcat(comp, ".compiled", sizeof(comp));
 623                 if (stat(comp, &stats) == 0) {
 624                         dbg("map compiled rules '%s'", comp);
 625                         if (rules_map(rules, comp) == 0)
 626                                 return 0;
 627                 }
 628         }
 629
 630         /* parse rules file or all matching files in directory */
 631         if (stat(udev_rules_filename, &stats) != 0)
 632                 return -1;
 633
 634         if ((stats.st_mode & S_IFMT) != S_IFDIR) {
 635                 dbg("parse single rules file '%s'", udev_rules_filename);
 636                 retval = parse_file(rules, udev_rules_filename);
 637         } else {
 638                 struct name_entry *name_loop, *name_tmp;
 639                 LIST_HEAD(name_list);
 640
 641                 dbg("parse rules directory '%s'", udev_rules_filename);
 642                 retval = add_matching_files(&name_list, udev_rules_filename, RULEFILE_SUFFIX);
 643
 644                 list_for_each_entry_safe(name_loop, name_tmp, &name_list, node) {
 645                         if (stat(name_loop->name, &stats) == 0) {
 646                                 if (stats.st_size)
 647                                         parse_file(rules, name_loop->name);
 648                                 else
 649                                         dbg("empty rules file '%s'", name_loop->name);
 650                         } else
 651                                 dbg("could not read '%s'", name_loop->name);
 652                         list_del(&name_loop->node);
 653                         free(name_loop);
 654                 }
 655         }
 656
 657         return retval;
 658 }
 659
 660 void udev_rules_close(struct udev_rules *rules)
 661 {
 662         if (rules->buf) {
 663                 if (rules->mapped) {
 664                         rules->mapped = 0;
 665                         file_unmap(rules->buf, rules->bufsize);
 666                 } else
 667                         free(rules->buf);
 668                 rules->buf = NULL;
 669         }
 670 }