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