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 LIST_HEAD(udev_rule_list);
  41
  42 static int add_config_dev(struct udev_rule *rule)
  43 {
  44         struct udev_rule *tmp_rule;
  45
  46         tmp_rule = malloc(sizeof(*tmp_rule));
  47         if (tmp_rule == NULL)
  48                 return -ENOMEM;
  49         memcpy(tmp_rule, rule, sizeof(struct udev_rule));
  50         list_add_tail(&tmp_rule->node, &udev_rule_list);
  51
  52         dbg("name='%s', symlink='%s', bus='%s', id='%s', "
  53             "sysfs_file[0]='%s', sysfs_value[0]='%s', "
  54             "kernel='%s', program='%s', result='%s', "
  55             "owner='%s', group='%s', mode=%#o, "
  56             "all_partions=%u, ignore_remove=%u, ignore_device=%u, last_rule=%u",
  57             rule->name, rule->symlink, rule->bus, rule->id,
  58             rule->sysfs_pair[0].file, rule->sysfs_pair[0].value,
  59             rule->kernel, rule->program, rule->result, rule->owner, rule->group, rule->mode,
  60             rule->partitions, rule->ignore_remove, rule->ignore_device, rule->last_rule);
  61
  62         return 0;
  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         }
  93
  94         /* remember end of key */
  95         temp = linepos;
  96
  97         /* skip whitespace after key */
  98         while (isspace(linepos[0]))
  99                 linepos++;
 100
 101         /* get operation type */
 102         if (linepos[0] == '=' && linepos[1] == '=') {
 103                 *operation = KEY_OP_MATCH;
 104                 linepos += 2;
 105                 dbg("operator=match");
 106         } else if (linepos[0] == '!' && linepos[1] == '=') {
 107                 *operation = KEY_OP_NOMATCH;
 108                 linepos += 2;
 109                 dbg("operator=nomatch");
 110         } else if (linepos[0] == '+' && linepos[1] == '=') {
 111                 *operation = KEY_OP_ADD;
 112                 linepos += 2;
 113                 dbg("operator=add");
 114         } else if (linepos[0] == '=') {
 115                 *operation = KEY_OP_ASSIGN;
 116                 linepos++;
 117                 dbg("operator=assign");
 118         } else
 119                 return -1;
 120
 121         /* terminate key */
 122         temp[0] = '\0';
 123         dbg("key='%s'", *key);
 124
 125         /* skip whitespace after operator */
 126         while (isspace(linepos[0]))
 127                 linepos++;
 128
 129         /* get the value*/
 130         if (linepos[0] == '"')
 131                 linepos++;
 132         else
 133                 return -1;
 134         *value = linepos;
 135
 136         temp = strchr(linepos, '"');
 137         if (!temp)
 138                 return -1;
 139         temp[0] = '\0';
 140         temp++;
 141         dbg("value='%s'", *value);
 142
 143         /* move line to next key */
 144         *line = temp;
 145
 146         return 0;
 147 }
 148
 149 /* extract possible KEY{attr} */
 150 static char *get_key_attribute(char *str)
 151 {
 152         char *pos;
 153         char *attr;
 154
 155         attr = strchr(str, '{');
 156         if (attr != NULL) {
 157                 attr++;
 158                 pos = strchr(attr, '}');
 159                 if (pos == NULL) {
 160                         dbg("missing closing brace for format");
 161                         return NULL;
 162                 }
 163                 pos[0] = '\0';
 164                 dbg("attribute='%s'", attr);
 165                 return attr;
 166         }
 167
 168         return NULL;
 169 }
 170
 171 static int rules_parse(struct udevice *udev, const char *filename)
 172 {
 173         char line[LINE_SIZE];
 174         char *bufline;
 175         int lineno;
 176         char *linepos;
 177         char *attr;
 178         char *buf;
 179         size_t bufsize;
 180         size_t cur;
 181         size_t count;
 182         int program_given = 0;
 183         int valid;
 184         int retval = 0;
 185         struct udev_rule rule;
 186
 187         if (file_map(filename, &buf, &bufsize) != 0) {
 188                 dbg("can't open '%s' as rules file", filename);
 189                 return -1;
 190         }
 191         dbg("reading '%s' as rules file", filename);
 192
 193         /* loop through the whole file */
 194         cur = 0;
 195         lineno = 0;
 196         while (cur < bufsize) {
 197                 unsigned int i, j;
 198
 199                 count = buf_get_line(buf, bufsize, cur);
 200                 bufline = &buf[cur];
 201                 cur += count+1;
 202                 lineno++;
 203
 204                 if (count >= sizeof(line)) {
 205                         info("line too long, rule skipped %s, line %d", filename, lineno);
 206                         continue;
 207                 }
 208
 209                 /* eat the whitespace */
 210                 while ((count > 0) && isspace(bufline[0])) {
 211                         bufline++;
 212                         count--;
 213                 }
 214                 if (count == 0)
 215                         continue;
 216
 217                 /* see if this is a comment */
 218                 if (bufline[0] == COMMENT_CHARACTER)
 219                         continue;
 220
 221                 /* skip backslash and newline from multi line rules */
 222                 for (i = j = 0; i < count; i++) {
 223                         if (bufline[i] == '\\' && bufline[i+1] == '\n')
 224                                 continue;
 225
 226                         line[j++] = bufline[i];
 227                 }
 228                 line[j] = '\0';
 229                 dbg("read '%s'", line);
 230
 231                 /* get all known keys */
 232                 memset(&rule, 0x00, sizeof(struct udev_rule));
 233                 linepos = line;
 234                 valid = 0;
 235
 236                 while (1) {
 237                         char *key;
 238                         char *value;
 239                         enum key_operation operation = KEY_OP_UNKNOWN;
 240
 241                         retval = get_key(&linepos, &key, &operation, &value);
 242                         if (retval)
 243                                 break;
 244
 245                         if (strcasecmp(key, KEY_KERNEL) == 0) {
 246                                 strlcpy(rule.kernel, value, sizeof(rule.kernel));
 247                                 rule.kernel_operation = operation;
 248                                 valid = 1;
 249                                 continue;
 250                         }
 251
 252                         if (strcasecmp(key, KEY_SUBSYSTEM) == 0) {
 253                                 strlcpy(rule.subsystem, value, sizeof(rule.subsystem));
 254                                 rule.subsystem_operation = operation;
 255                                 valid = 1;
 256                                 continue;
 257                         }
 258
 259                         if (strcasecmp(key, KEY_BUS) == 0) {
 260                                 strlcpy(rule.bus, value, sizeof(rule.bus));
 261                                 rule.bus_operation = operation;
 262                                 valid = 1;
 263                                 continue;
 264                         }
 265
 266                         if (strcasecmp(key, KEY_ID) == 0) {
 267                                 strlcpy(rule.id, value, sizeof(rule.id));
 268                                 rule.id_operation = operation;
 269                                 valid = 1;
 270                                 continue;
 271                         }
 272
 273                         if (strncasecmp(key, KEY_SYSFS, sizeof(KEY_SYSFS)-1) == 0) {
 274                                 struct sysfs_pair *pair = &rule.sysfs_pair[0];
 275                                 int sysfs_pair_num = 0;
 276
 277                                 /* find first unused pair */
 278                                 while (pair->file[0] != '\0') {
 279                                         ++sysfs_pair_num;
 280                                         if (sysfs_pair_num >= MAX_SYSFS_PAIRS) {
 281                                                 pair = NULL;
 282                                                 break;
 283                                         }
 284                                         ++pair;
 285                                 }
 286                                 if (pair) {
 287                                         attr = get_key_attribute(key + sizeof(KEY_SYSFS)-1);
 288                                         if (attr == NULL) {
 289                                                 dbg("error parsing " KEY_SYSFS " attribute");
 290                                                 continue;
 291                                         }
 292                                         strlcpy(pair->file, attr, sizeof(pair->file));
 293                                         strlcpy(pair->value, value, sizeof(pair->value));
 294                                         pair->operation = operation;
 295                                         valid = 1;
 296                                 }
 297                                 continue;
 298                         }
 299
 300                         if (strcasecmp(key, KEY_DRIVER) == 0) {
 301                                 strlcpy(rule.driver, value, sizeof(rule.driver));
 302                                 rule.driver_operation = operation;
 303                                 valid = 1;
 304                                 continue;
 305                         }
 306
 307                         if (strcasecmp(key, KEY_RESULT) == 0) {
 308                                 strlcpy(rule.result, value, sizeof(rule.result));
 309                                 rule.result_operation = operation;
 310                                 valid = 1;
 311                                 continue;
 312                         }
 313
 314                         if (strcasecmp(key, KEY_PROGRAM) == 0) {
 315                                 strlcpy(rule.program, value, sizeof(rule.program));
 316                                 rule.program_operation = operation;
 317                                 program_given = 1;
 318                                 valid = 1;
 319                                 continue;
 320                         }
 321
 322                         if (strncasecmp(key, KEY_NAME, sizeof(KEY_NAME)-1) == 0) {
 323                                 attr = get_key_attribute(key + sizeof(KEY_NAME)-1);
 324                                 /* FIXME: remove old style options and make OPTIONS= mandatory */
 325                                 if (attr != NULL) {
 326                                         if (strstr(attr, OPTION_PARTITIONS) != NULL) {
 327                                                 dbg("creation of partition nodes requested");
 328                                                 rule.partitions = DEFAULT_PARTITIONS_COUNT;
 329                                         }
 330                                         if (strstr(attr, OPTION_IGNORE_REMOVE) != NULL) {
 331                                                 dbg("remove event should be ignored");
 332                                                 rule.ignore_remove = 1;
 333                                         }
 334                                 }
 335                                 if (value[0] != '\0')
 336                                         strlcpy(rule.name, value, sizeof(rule.name));
 337                                 else
 338                                         rule.ignore_device = 1;
 339                                 valid = 1;
 340                                 continue;
 341                         }
 342
 343                         if (strcasecmp(key, KEY_SYMLINK) == 0) {
 344                                 strlcpy(rule.symlink, value, sizeof(rule.symlink));
 345                                 valid = 1;
 346                                 continue;
 347                         }
 348
 349                         if (strcasecmp(key, KEY_OWNER) == 0) {
 350                                 strlcpy(rule.owner, value, sizeof(rule.owner));
 351                                 valid = 1;
 352                                 continue;
 353                         }
 354
 355                         if (strcasecmp(key, KEY_GROUP) == 0) {
 356                                 strlcpy(rule.group, value, sizeof(rule.group));
 357                                 valid = 1;
 358                                 continue;
 359                         }
 360
 361                         if (strcasecmp(key, KEY_MODE) == 0) {
 362                                 rule.mode = strtol(value, NULL, 8);
 363                                 valid = 1;
 364                                 continue;
 365                         }
 366
 367                         if (strcasecmp(key, KEY_OPTIONS) == 0) {
 368                                 if (strstr(value, OPTION_LAST_RULE) != NULL) {
 369                                         dbg("last rule to be applied");
 370                                         rule.last_rule = 1;
 371                                 }
 372                                 if (strstr(value, OPTION_IGNORE_DEVICE) != NULL) {
 373                                         dbg("device should be ignored");
 374                                         rule.ignore_device = 1;
 375                                 }
 376                                 if (strstr(value, OPTION_IGNORE_REMOVE) != NULL) {
 377                                         dbg("remove event should be ignored");
 378                                         rule.ignore_remove = 1;
 379                                 }
 380                                 if (strstr(value, OPTION_PARTITIONS) != NULL) {
 381                                         dbg("creation of partition nodes requested");
 382                                         rule.partitions = DEFAULT_PARTITIONS_COUNT;
 383                                 }
 384                                 valid = 1;
 385                                 continue;
 386                         }
 387
 388                         dbg("unknown key '%s'", key);
 389                         goto error;
 390                 }
 391
 392                 /* skip line if not any valid key was found */
 393                 if (!valid)
 394                         goto error;
 395
 396                 /* simple plausibility checks for given keys */
 397                 if ((rule.sysfs_pair[0].file[0] == '\0') ^
 398                     (rule.sysfs_pair[0].value[0] == '\0')) {
 399                         info("inconsistency in " KEY_SYSFS " key");
 400                         goto error;
 401                 }
 402
 403                 if ((rule.result[0] != '\0') && (program_given == 0)) {
 404                         info(KEY_RESULT " is only useful when "
 405                              KEY_PROGRAM " is called in any rule before");
 406                         goto error;
 407                 }
 408
 409                 rule.config_line = lineno;
 410                 strlcpy(rule.config_file, filename, sizeof(rule.config_file));
 411                 retval = add_config_dev(&rule);
 412                 if (retval) {
 413                         dbg("add_config_dev returned with error %d", retval);
 414                         continue;
 415 error:
 416                         info("parse error %s, line %d:%d, rule skipped",
 417                              filename, lineno, (int) (linepos - line));
 418                 }
 419         }
 420
 421         file_unmap(buf, bufsize);
 422         return retval;
 423 }
 424
 425 int udev_rules_init(void)
 426 {
 427         struct stat stats;
 428         int retval;
 429
 430         if (stat(udev_rules_filename, &stats) != 0)
 431                 return -1;
 432
 433         if ((stats.st_mode & S_IFMT) != S_IFDIR)
 434                 retval = rules_parse(NULL, udev_rules_filename);
 435         else
 436                 retval = call_foreach_file(rules_parse, NULL, udev_rules_filename, RULEFILE_SUFFIX);
 437
 438         return retval;
 439 }
 440
 441 void udev_rules_close(void)
 442 {
 443         struct udev_rule *rule;
 444         struct udev_rule *temp_rule;
 445
 446         list_for_each_entry_safe(rule, temp_rule, &udev_rule_list, node) {
 447                 list_del(&rule->node);
 448                 free(rule);
 449         }
 450 }
 451