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, not creation supressed");
 418                         add_rule_key(rule, &rule->name, operation, value);
 419                         continue;
 420                 }
 421
 422                 if (strcasecmp(key, "SYMLINK") == 0) {
 423                         add_rule_key(rule, &rule->symlink, operation, value);
 424                         valid = 1;
 425                         continue;
 426                 }
 427
 428                 if (strcasecmp(key, "OWNER") == 0) {
 429                         valid = 1;
 430                         if (rules->resolve_names && (!strchr(value, '$') && !strchr(value, '%'))) {
 431                                 char *endptr;
 432                                 strtoul(value, &endptr, 10);
 433                                 if (endptr[0] != '\0') {
 434                                         char owner[32];
 435                                         uid_t uid = lookup_user(value);
 436                                         dbg("replacing username='%s' by id=%i", value, uid);
 437                                         sprintf(owner, "%u", (unsigned int) uid);
 438                                         add_rule_key(rule, &rule->owner, operation, owner);
 439                                         continue;
 440                                 }
 441                         }
 442
 443                         add_rule_key(rule, &rule->owner, operation, value);
 444                         continue;
 445                 }
 446
 447                 if (strcasecmp(key, "GROUP") == 0) {
 448                         valid = 1;
 449                         if (rules->resolve_names && (!strchr(value, '$') && !strchr(value, '%'))) {
 450                                 char *endptr;
 451                                 strtoul(value, &endptr, 10);
 452                                 if (endptr[0] != '\0') {
 453                                         char group[32];
 454                                         gid_t gid = lookup_group(value);
 455                                         dbg("replacing groupname='%s' by id=%i", value, gid);
 456                                         sprintf(group, "%u", (unsigned int) gid);
 457                                         add_rule_key(rule, &rule->group, operation, group);
 458                                         continue;
 459                                 }
 460                         }
 461
 462                         add_rule_key(rule, &rule->group, operation, value);
 463                         continue;
 464                 }
 465
 466                 if (strcasecmp(key, "MODE") == 0) {
 467                         rule->mode = strtol(value, NULL, 8);
 468                         rule->mode_operation = operation;
 469                         valid = 1;
 470                         continue;
 471                 }
 472
 473                 if (strcasecmp(key, "RUN") == 0) {
 474                         add_rule_key(rule, &rule->run, operation, value);
 475                         valid = 1;
 476                         continue;
 477                 }
 478
 479                 if (strcasecmp(key, "OPTIONS") == 0) {
 480                         if (strstr(value, "last_rule") != NULL) {
 481                                 dbg("last rule to be applied");
 482                                 rule->last_rule = 1;
 483                         }
 484                         if (strstr(value, "ignore_device") != NULL) {
 485                                 dbg("device should be ignored");
 486                                 rule->ignore_device = 1;
 487                         }
 488                         if (strstr(value, "ignore_remove") != NULL) {
 489                                 dbg("remove event should be ignored");
 490                                 rule->ignore_remove = 1;
 491                         }
 492                         if (strstr(value, "all_partitions") != NULL) {
 493                                 dbg("creation of partition nodes requested");
 494                                 rule->partitions = DEFAULT_PARTITIONS_COUNT;
 495                         }
 496                         valid = 1;
 497                         continue;
 498                 }
 499
 500                 err("unknown key '%s', in '%s'", key, line);
 501         }
 502
 503         /* skip line if not any valid key was found */
 504         if (!valid) {
 505                 err("invalid rule '%s'", line);
 506                 goto exit;
 507         }
 508
 509         /* grow buffer and add rule */
 510         rule_size = sizeof(struct udev_rule) + rule->bufsize;
 511         padding = (sizeof(size_t) - rule_size % sizeof(size_t)) % sizeof(size_t);
 512         dbg("add %zi padding bytes", padding);
 513         rule_size += padding;
 514         rule->bufsize += padding;
 515
 516         rules->buf = realloc(rules->buf, rules->bufsize + rule_size);
 517         if (!rules->buf) {
 518                 err("realloc failed");
 519                 goto exit;
 520         }
 521         dbg("adding rule to offset %zi", rules->bufsize);
 522         memcpy(rules->buf + rules->bufsize, rule, rule_size);
 523         rules->bufsize += rule_size;
 524 exit:
 525         free(rule);
 526         return 0;
 527 }
 528
 529 static int parse_file(struct udev_rules *rules, const char *filename)
 530 {
 531         char line[LINE_SIZE];
 532         char *bufline;
 533         int lineno;
 534         char *buf;
 535         size_t bufsize;
 536         size_t cur;
 537         size_t count;
 538         int retval = 0;
 539
 540         if (file_map(filename, &buf, &bufsize) != 0) {
 541                 err("can't open '%s' as rules file: %s", filename, strerror(errno));
 542                 return -1;
 543         }
 544         dbg("reading '%s' as rules file", filename);
 545
 546         /* loop through the whole file */
 547         cur = 0;
 548         lineno = 0;
 549         while (cur < bufsize) {
 550                 unsigned int i, j;
 551
 552                 count = buf_get_line(buf, bufsize, cur);
 553                 bufline = &buf[cur];
 554                 cur += count+1;
 555                 lineno++;
 556
 557                 if (count >= sizeof(line)) {
 558                         info("line too long, rule skipped %s, line %d", filename, lineno);
 559                         continue;
 560                 }
 561
 562                 /* eat the whitespace */
 563                 while ((count > 0) && isspace(bufline[0])) {
 564                         bufline++;
 565                         count--;
 566                 }
 567                 if (count == 0)
 568                         continue;
 569
 570                 /* see if this is a comment */
 571                 if (bufline[0] == COMMENT_CHARACTER)
 572                         continue;
 573
 574                 /* skip backslash and newline from multi line rules */
 575                 for (i = j = 0; i < count; i++) {
 576                         if (bufline[i] == '\\' && bufline[i+1] == '\n')
 577                                 continue;
 578
 579                         line[j++] = bufline[i];
 580                 }
 581                 line[j] = '\0';
 582
 583                 dbg("read '%s'", line);
 584                 add_to_rules(rules, line);
 585         }
 586
 587         file_unmap(buf, bufsize);
 588         return retval;
 589 }
 590
 591 int udev_rules_init(struct udev_rules *rules, int resolve_names)
 592 {
 593         struct stat stats;
 594         int retval;
 595
 596         memset(rules, 0x00, sizeof(struct udev_rules));
 597         rules->resolve_names = resolve_names;
 598
 599         /* parse rules file or all matching files in directory */
 600         if (stat(udev_rules_filename, &stats) != 0)
 601                 return -1;
 602
 603         if ((stats.st_mode & S_IFMT) != S_IFDIR) {
 604                 dbg("parse single rules file '%s'", udev_rules_filename);
 605                 retval = parse_file(rules, udev_rules_filename);
 606         } else {
 607                 struct name_entry *name_loop, *name_tmp;
 608                 LIST_HEAD(name_list);
 609
 610                 dbg("parse rules directory '%s'", udev_rules_filename);
 611                 retval = add_matching_files(&name_list, udev_rules_filename, RULEFILE_SUFFIX);
 612
 613                 list_for_each_entry_safe(name_loop, name_tmp, &name_list, node) {
 614                         if (stat(name_loop->name, &stats) == 0) {
 615                                 if (stats.st_size)
 616                                         parse_file(rules, name_loop->name);
 617                                 else
 618                                         dbg("empty rules file '%s'", name_loop->name);
 619                         } else
 620                                 err("could not read '%s': %s", name_loop->name, strerror(errno));
 621                         list_del(&name_loop->node);
 622                         free(name_loop);
 623                 }
 624         }
 625
 626         return retval;
 627 }
 628
 629 void udev_rules_close(struct udev_rules *rules)
 630 {
 631         if (rules->buf) {
 632                 free(rules->buf);
 633                 rules->buf = NULL;
 634         }
 635 }