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         size_t padding;
 245         int retval;
 246
 247         /* get all the keys */
 248         rule = calloc(1, sizeof (struct udev_rule) + LINE_SIZE);
 249         if (!rule) {
 250                 err("malloc failed");
 251                 return -1;
 252         }
 253         linepos = line;
 254         valid = 0;
 255
 256         while (1) {
 257                 char *key;
 258                 char *value;
 259                 enum key_operation operation = KEY_OP_UNSET;
 260
 261                 retval = get_key(&linepos, &key, &operation, &value);
 262                 if (retval)
 263                         break;
 264
 265                 if (strcasecmp(key, "LABEL") == 0) {
 266                         add_rule_key(rule, &rule->label, operation, value);
 267                         valid = 1;
 268                         continue;
 269                 }
 270
 271                 if (strcasecmp(key, "GOTO") == 0) {
 272                         add_rule_key(rule, &rule->goto_label, operation, value);
 273                         valid = 1;
 274                         continue;
 275                 }
 276
 277                 if (strcasecmp(key, "KERNEL") == 0) {
 278                         add_rule_key(rule, &rule->kernel_name, operation, value);
 279                         valid = 1;
 280                         continue;
 281                 }
 282
 283                 if (strcasecmp(key, "SUBSYSTEM") == 0) {
 284                         add_rule_key(rule, &rule->subsystem, operation, value);
 285                         valid = 1;
 286                         continue;
 287                 }
 288
 289                 if (strcasecmp(key, "ACTION") == 0) {
 290                         add_rule_key(rule, &rule->action, operation, value);
 291                         valid = 1;
 292                         continue;
 293                 }
 294
 295                 if (strcasecmp(key, "DEVPATH") == 0) {
 296                         add_rule_key(rule, &rule->devpath, operation, value);
 297                         valid = 1;
 298                         continue;
 299                 }
 300
 301                 if (strcasecmp(key, "BUS") == 0) {
 302                         add_rule_key(rule, &rule->bus, operation, value);
 303                         valid = 1;
 304                         continue;
 305                 }
 306
 307                 if (strcasecmp(key, "ID") == 0) {
 308                         add_rule_key(rule, &rule->id, operation, value);
 309                         valid = 1;
 310                         continue;
 311                 }
 312
 313                 if (strncasecmp(key, "SYSFS", sizeof("SYSFS")-1) == 0) {
 314                         attr = get_key_attribute(key + sizeof("SYSFS")-1);
 315                         if (attr == NULL) {
 316                                 err("error parsing SYSFS attribute in '%s'", line);
 317                                 continue;
 318                         }
 319                         add_rule_key_pair(rule, &rule->sysfs, operation, attr, value);
 320                         valid = 1;
 321                         continue;
 322                 }
 323
 324                 if (strcasecmp(key, "WAIT_FOR_SYSFS") == 0) {
 325                         add_rule_key(rule, &rule->wait_for_sysfs, operation, value);
 326                         valid = 1;
 327                         continue;
 328                 }
 329
 330                 if (strncasecmp(key, "ENV", sizeof("ENV")-1) == 0) {
 331                         attr = get_key_attribute(key + sizeof("ENV")-1);
 332                         if (attr == NULL) {
 333                                 err("error parsing ENV attribute");
 334                                 continue;
 335                         }
 336                         add_rule_key_pair(rule, &rule->env, operation, attr, value);
 337                         valid = 1;
 338                         continue;
 339                 }
 340
 341                 if (strcasecmp(key, "MODALIAS") == 0) {
 342                         add_rule_key(rule, &rule->modalias, operation, value);
 343                         valid = 1;
 344                         continue;
 345                 }
 346
 347                 if (strncasecmp(key, "IMPORT", sizeof("IMPORT")-1) == 0) {
 348                         attr = get_key_attribute(key + sizeof("IMPORT")-1);
 349                         if (attr && strstr(attr, "program")) {
 350                                 dbg("IMPORT will be executed");
 351                                 rule->import_type  = IMPORT_PROGRAM;
 352                         } else if (attr && strstr(attr, "file")) {
 353                                 dbg("IMPORT will be included as file");
 354                                 rule->import_type  = IMPORT_FILE;
 355                         } else if (attr && strstr(attr, "parent")) {
 356                                 dbg("IMPORT will include the parent values");
 357                                 rule->import_type = IMPORT_PARENT;
 358                         } else {
 359                                 /* figure it out if it is executable */
 360                                 char file[PATH_SIZE];
 361                                 char *pos;
 362                                 struct stat stats;
 363
 364                                 strlcpy(file, value, sizeof(file));
 365                                 pos = strchr(file, ' ');
 366                                 if (pos)
 367                                         pos[0] = '\0';
 368                                 dbg("IMPORT auto mode for '%s'", file);
 369                                 if (!lstat(file, &stats) && (stats.st_mode & S_IXUSR)) {
 370                                         dbg("IMPORT is executable, will be executed (autotype)");
 371                                         rule->import_type  = IMPORT_PROGRAM;
 372                                 } else {
 373                                         dbg("IMPORT is not executable, will be included as file (autotype)");
 374                                         rule->import_type  = IMPORT_FILE;
 375                                 }
 376                         }
 377                         add_rule_key(rule, &rule->import, operation, value);
 378                         valid = 1;
 379                         continue;
 380                 }
 381
 382                 if (strcasecmp(key, "DRIVER") == 0) {
 383                         add_rule_key(rule, &rule->driver, operation, value);
 384                         valid = 1;
 385                         continue;
 386                 }
 387
 388                 if (strcasecmp(key, "RESULT") == 0) {
 389                         add_rule_key(rule, &rule->result, operation, value);
 390                         valid = 1;
 391                         continue;
 392                 }
 393
 394                 if (strcasecmp(key, "PROGRAM") == 0) {
 395                         add_rule_key(rule, &rule->program, operation, value);
 396                         valid = 1;
 397                         continue;
 398                 }
 399
 400                 if (strncasecmp(key, "NAME", sizeof("NAME")-1) == 0) {
 401                         attr = get_key_attribute(key + sizeof("NAME")-1);
 402                         if (attr != NULL) {
 403                                 if (strstr(attr, "all_partitions") != NULL) {
 404                                         dbg("creation of partition nodes requested");
 405                                         rule->partitions = DEFAULT_PARTITIONS_COUNT;
 406                                 }
 407                                 if (strstr(attr, "ignore_remove") != NULL) {
 408                                         dbg("remove event should be ignored");
 409                                         rule->ignore_remove = 1;
 410                                 }
 411                         }
 412                         if (value[0] == '\0') {
 413                                 dbg("name empty device should be ignored");
 414                                 rule->name.operation = operation;
 415                                 rule->ignore_device = 1;
 416                         } else
 417                                 add_rule_key(rule, &rule->name, operation, value);
 418                         continue;
 419                 }
 420
 421                 if (strcasecmp(key, "SYMLINK") == 0) {
 422                         add_rule_key(rule, &rule->symlink, operation, value);
 423                         valid = 1;
 424                         continue;
 425                 }
 426
 427                 if (strcasecmp(key, "OWNER") == 0) {
 428                         valid = 1;
 429                         if (rules->resolve_names && (!strchr(value, '$') && !strchr(value, '%'))) {
 430                                 char *endptr;
 431                                 strtoul(value, &endptr, 10);
 432                                 if (endptr[0] != '\0') {
 433                                         char owner[32];
 434                                         uid_t uid = lookup_user(value);
 435                                         dbg("replacing username='%s' by id=%i", value, uid);
 436                                         sprintf(owner, "%li", uid);
 437                                         add_rule_key(rule, &rule->owner, operation, owner);
 438                                         continue;
 439                                 }
 440                         }
 441
 442                         add_rule_key(rule, &rule->owner, operation, value);
 443                         continue;
 444                 }
 445
 446                 if (strcasecmp(key, "GROUP") == 0) {
 447                         valid = 1;
 448                         if (rules->resolve_names && (!strchr(value, '$') && !strchr(value, '%'))) {
 449                                 char *endptr;
 450                                 strtoul(value, &endptr, 10);
 451                                 if (endptr[0] != '\0') {
 452                                         char group[32];
 453                                         gid_t gid = lookup_group(value);
 454                                         dbg("replacing groupname='%s' by id=%i", value, gid);
 455                                         sprintf(group, "%li", gid);
 456                                         add_rule_key(rule, &rule->group, operation, group);
 457                                         continue;
 458                                 }
 459                         }
 460
 461                         add_rule_key(rule, &rule->group, operation, value);
 462                         continue;
 463                 }
 464
 465                 if (strcasecmp(key, "MODE") == 0) {
 466                         rule->mode = strtol(value, NULL, 8);
 467                         rule->mode_operation = operation;
 468                         valid = 1;
 469                         continue;
 470                 }
 471
 472                 if (strcasecmp(key, "RUN") == 0) {
 473                         add_rule_key(rule, &rule->run, operation, value);
 474                         valid = 1;
 475                         continue;
 476                 }
 477
 478                 if (strcasecmp(key, "OPTIONS") == 0) {
 479                         if (strstr(value, "last_rule") != NULL) {
 480                                 dbg("last rule to be applied");
 481                                 rule->last_rule = 1;
 482                         }
 483                         if (strstr(value, "ignore_device") != NULL) {
 484                                 dbg("device should be ignored");
 485                                 rule->ignore_device = 1;
 486                         }
 487                         if (strstr(value, "ignore_remove") != NULL) {
 488                                 dbg("remove event should be ignored");
 489                                 rule->ignore_remove = 1;
 490                         }
 491                         if (strstr(value, "all_partitions") != NULL) {
 492                                 dbg("creation of partition nodes requested");
 493                                 rule->partitions = DEFAULT_PARTITIONS_COUNT;
 494                         }
 495                         valid = 1;
 496                         continue;
 497                 }
 498
 499                 err("unknown key '%s', in '%s'", key, line);
 500         }
 501
 502         /* skip line if not any valid key was found */
 503         if (!valid) {
 504                 err("invalid rule '%s'", line);
 505                 goto exit;
 506         }
 507
 508         /* grow buffer and add rule */
 509         rule_size = sizeof(struct udev_rule) + rule->bufsize;
 510         padding = (sizeof(size_t) - rule_size % sizeof(size_t)) % sizeof(size_t);
 511         dbg("add %zi padding bytes", padding);
 512         rule_size += padding;
 513         rule->bufsize += padding;
 514
 515         rules->buf = realloc(rules->buf, rules->bufsize + rule_size);
 516         if (!rules->buf) {
 517                 err("realloc failed");
 518                 goto exit;
 519         }
 520         dbg("adding rule to offset %zi", rules->bufsize);
 521         memcpy(rules->buf + rules->bufsize, rule, rule_size);
 522         rules->bufsize += rule_size;
 523 exit:
 524         free(rule);
 525         return 0;
 526 }
 527
 528 static int parse_file(struct udev_rules *rules, const char *filename)
 529 {
 530         char line[LINE_SIZE];
 531         char *bufline;
 532         int lineno;
 533         char *buf;
 534         size_t bufsize;
 535         size_t cur;
 536         size_t count;
 537         int retval = 0;
 538
 539         if (file_map(filename, &buf, &bufsize) != 0) {
 540                 err("can't open '%s' as rules file", filename);
 541                 return -1;
 542         }
 543         dbg("reading '%s' as rules file", filename);
 544
 545         /* loop through the whole file */
 546         cur = 0;
 547         lineno = 0;
 548         while (cur < bufsize) {
 549                 unsigned int i, j;
 550
 551                 count = buf_get_line(buf, bufsize, cur);
 552                 bufline = &buf[cur];
 553                 cur += count+1;
 554                 lineno++;
 555
 556                 if (count >= sizeof(line)) {
 557                         info("line too long, rule skipped %s, line %d", filename, lineno);
 558                         continue;
 559                 }
 560
 561                 /* eat the whitespace */
 562                 while ((count > 0) && isspace(bufline[0])) {
 563                         bufline++;
 564                         count--;
 565                 }
 566                 if (count == 0)
 567                         continue;
 568
 569                 /* see if this is a comment */
 570                 if (bufline[0] == COMMENT_CHARACTER)
 571                         continue;
 572
 573                 /* skip backslash and newline from multi line rules */
 574                 for (i = j = 0; i < count; i++) {
 575                         if (bufline[i] == '\\' && bufline[i+1] == '\n')
 576                                 continue;
 577
 578                         line[j++] = bufline[i];
 579                 }
 580                 line[j] = '\0';
 581
 582                 dbg("read '%s'", line);
 583                 add_to_rules(rules, line);
 584         }
 585
 586         file_unmap(buf, bufsize);
 587         return retval;
 588 }
 589
 590 static int rules_map(struct udev_rules *rules, const char *filename)
 591 {
 592         if (file_map(filename, &rules->buf, &rules->bufsize)) {
 593                 rules->buf = NULL;
 594                 return -1;
 595         }
 596         if (rules->bufsize == 0) {
 597                 file_unmap(rules->buf, rules->bufsize);
 598                 rules->buf = NULL;
 599                 return -1;
 600         }
 601         rules->mapped = 1;
 602
 603         return 0;
 604 }
 605
 606 int udev_rules_init(struct udev_rules *rules, int resolve_names)
 607 {
 608         char comp[PATH_SIZE];
 609         struct stat stats;
 610         int retval;
 611
 612         memset(rules, 0x00, sizeof(struct udev_rules));
 613         rules->resolve_names = resolve_names;
 614
 615         /* check for precompiled rules */
 616         strlcpy(comp, udev_rules_filename, sizeof(comp));
 617         strlcat(comp, ".compiled", sizeof(comp));
 618         if (stat(comp, &stats) == 0) {
 619                 dbg("map compiled rules '%s'", comp);
 620                 if (rules_map(rules, comp) == 0)
 621                         return 0;
 622         }
 623
 624         if (stat(udev_rules_filename, &stats) != 0)
 625                 return -1;
 626
 627         if ((stats.st_mode & S_IFMT) != S_IFDIR) {
 628                 dbg("parse single rules file '%s'", udev_rules_filename);
 629                 retval = parse_file(rules, udev_rules_filename);
 630         } else {
 631                 struct name_entry *name_loop, *name_tmp;
 632                 LIST_HEAD(name_list);
 633
 634                 dbg("parse rules directory '%s'", udev_rules_filename);
 635                 retval = add_matching_files(&name_list, udev_rules_filename, RULEFILE_SUFFIX);
 636
 637                 list_for_each_entry_safe(name_loop, name_tmp, &name_list, node) {
 638                         parse_file(rules, name_loop->name);
 639                         list_del(&name_loop->node);
 640                 }
 641         }
 642
 643         return retval;
 644 }
 645
 646 void udev_rules_close(struct udev_rules *rules)
 647 {
 648         if (rules->mapped)
 649                 file_unmap(rules->buf, rules->bufsize);
 650         else
 651                 free(rules->buf);
 652
 653         rules->buf = NULL;
 654 }