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 *new_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, new_rule, sizeof(*tmp_rule));
  50         list_add_tail(&tmp_rule->node, &udev_rule_list);
  51         udev_rule_dump(tmp_rule);
  52
  53         return 0;
  54 }
  55
  56 void udev_rule_dump(struct udev_rule *rule)
  57 {
  58         dbg("name='%s', symlink='%s', bus='%s', id='%s', "
  59             "sysfs_file[0]='%s', sysfs_value[0]='%s', "
  60             "kernel='%s', program='%s', result='%s'"
  61             "owner='%s', group='%s', mode=%#o",
  62             rule->name, rule->symlink, rule->bus, rule->id,
  63             rule->sysfs_pair[0].file, rule->sysfs_pair[0].value,
  64             rule->kernel, rule->program, rule->result,
  65             rule->owner, rule->group, rule->mode);
  66 }
  67
  68 void udev_rule_list_dump(void)
  69 {
  70         struct udev_rule *rule;
  71
  72         list_for_each_entry(rule, &udev_rule_list, node)
  73                 udev_rule_dump(rule);
  74 }
  75
  76 /* extract possible KEY{attr} */
  77 static char *get_key_attribute(char *str)
  78 {
  79         char *pos;
  80         char *attr;
  81
  82         attr = strchr(str, '{');
  83         if (attr != NULL) {
  84                 attr++;
  85                 pos = strchr(attr, '}');
  86                 if (pos == NULL) {
  87                         dbg("missing closing brace for format");
  88                         return NULL;
  89                 }
  90                 pos[0] = '\0';
  91                 dbg("attribute='%s'", attr);
  92                 return attr;
  93         }
  94
  95         return NULL;
  96 }
  97
  98 static int rules_parse(struct udevice *udev, const char *filename)
  99 {
 100         char line[LINE_SIZE];
 101         char *bufline;
 102         int lineno;
 103         char *temp;
 104         char *temp2;
 105         char *temp3;
 106         char *attr;
 107         char *buf;
 108         size_t bufsize;
 109         size_t cur;
 110         size_t count;
 111         int program_given = 0;
 112         int valid;
 113         int retval = 0;
 114         struct udev_rule rule;
 115
 116         if (file_map(filename, &buf, &bufsize) == 0) {
 117                 dbg("reading '%s' as rules file", filename);
 118         } else {
 119                 dbg("can't open '%s' as rules file", filename);
 120                 return -1;
 121         }
 122
 123         /* loop through the whole file */
 124         cur = 0;
 125         lineno = 0;
 126         while (cur < bufsize) {
 127                 unsigned int i, j;
 128
 129                 count = buf_get_line(buf, bufsize, cur);
 130                 bufline = &buf[cur];
 131                 cur += count+1;
 132                 lineno++;
 133
 134                 if (count >= sizeof(line)) {
 135                         info("line too long, rule skipped %s, line %d", filename, lineno);
 136                         continue;
 137                 }
 138
 139                 /* eat the whitespace */
 140                 while ((count > 0) && isspace(bufline[0])) {
 141                         bufline++;
 142                         count--;
 143                 }
 144                 if (count == 0)
 145                         continue;
 146
 147                 /* see if this is a comment */
 148                 if (bufline[0] == COMMENT_CHARACTER)
 149                         continue;
 150
 151                 /* skip backslash and newline from multi line rules */
 152                 for (i = j = 0; i < count; i++) {
 153                         if (bufline[i] == '\\' && bufline[i+1] == '\n')
 154                                 continue;
 155
 156                         line[j++] = bufline[i];
 157                 }
 158                 line[j] = '\0';
 159                 dbg("read '%s'", line);
 160
 161                 /* get all known keys */
 162                 memset(&rule, 0x00, sizeof(struct udev_rule));
 163                 temp = line;
 164                 valid = 0;
 165
 166                 while (1) {
 167                         retval = parse_get_pair(&temp, &temp2, &temp3);
 168                         if (retval)
 169                                 break;
 170
 171                         if (strcasecmp(temp2, FIELD_KERNEL) == 0) {
 172                                 strlcpy(rule.kernel, temp3, sizeof(rule.kernel));
 173                                 valid = 1;
 174                                 continue;
 175                         }
 176
 177                         if (strcasecmp(temp2, FIELD_SUBSYSTEM) == 0) {
 178                                 strlcpy(rule.subsystem, temp3, sizeof(rule.subsystem));
 179                                 valid = 1;
 180                                 continue;
 181                         }
 182
 183                         if (strcasecmp(temp2, FIELD_BUS) == 0) {
 184                                 strlcpy(rule.bus, temp3, sizeof(rule.bus));
 185                                 valid = 1;
 186                                 continue;
 187                         }
 188
 189                         if (strcasecmp(temp2, FIELD_ID) == 0) {
 190                                 strlcpy(rule.id, temp3, sizeof(rule.id));
 191                                 valid = 1;
 192                                 continue;
 193                         }
 194
 195                         if (strncasecmp(temp2, FIELD_SYSFS, sizeof(FIELD_SYSFS)-1) == 0) {
 196                                 struct sysfs_pair *pair = &rule.sysfs_pair[0];
 197                                 int sysfs_pair_num = 0;
 198
 199                                 /* find first unused pair */
 200                                 while (pair->file[0] != '\0') {
 201                                         ++sysfs_pair_num;
 202                                         if (sysfs_pair_num >= MAX_SYSFS_PAIRS) {
 203                                                 pair = NULL;
 204                                                 break;
 205                                         }
 206                                         ++pair;
 207                                 }
 208                                 if (pair) {
 209                                         attr = get_key_attribute(temp2 + sizeof(FIELD_SYSFS)-1);
 210                                         if (attr == NULL) {
 211                                                 dbg("error parsing " FIELD_SYSFS " attribute");
 212                                                 continue;
 213                                         }
 214                                         strlcpy(pair->file, attr, sizeof(pair->file));
 215                                         strlcpy(pair->value, temp3, sizeof(pair->value));
 216                                         valid = 1;
 217                                 }
 218                                 continue;
 219                         }
 220
 221                         if (strcasecmp(temp2, FIELD_DRIVER) == 0) {
 222                                 strlcpy(rule.driver, temp3, sizeof(rule.driver));
 223                                 valid = 1;
 224                                 continue;
 225                         }
 226
 227                         if (strcasecmp(temp2, FIELD_PROGRAM) == 0) {
 228                                 program_given = 1;
 229                                 strlcpy(rule.program, temp3, sizeof(rule.program));
 230                                 valid = 1;
 231                                 continue;
 232                         }
 233
 234                         if (strcasecmp(temp2, FIELD_RESULT) == 0) {
 235                                 strlcpy(rule.result, temp3, sizeof(rule.result));
 236                                 valid = 1;
 237                                 continue;
 238                         }
 239
 240                         if (strncasecmp(temp2, FIELD_NAME, sizeof(FIELD_NAME)-1) == 0) {
 241                                 attr = get_key_attribute(temp2 + sizeof(FIELD_NAME)-1);
 242                                 /* FIXME: remove old style options and make OPTIONS= mandatory */
 243                                 if (attr != NULL) {
 244                                         if (strstr(attr, OPTION_PARTITIONS) != NULL) {
 245                                                 dbg("creation of partition nodes requested");
 246                                                 rule.partitions = DEFAULT_PARTITIONS_COUNT;
 247                                         }
 248                                         if (strstr(attr, OPTION_IGNORE_REMOVE) != NULL) {
 249                                                 dbg("remove event should be ignored");
 250                                                 rule.ignore_remove = 1;
 251                                         }
 252                                 }
 253                                 if (temp3[0] != '\0')
 254                                         strlcpy(rule.name, temp3, sizeof(rule.name));
 255                                 else
 256                                         rule.ignore_device = 1;
 257                                 valid = 1;
 258                                 continue;
 259                         }
 260
 261                         if (strcasecmp(temp2, FIELD_SYMLINK) == 0) {
 262                                 strlcpy(rule.symlink, temp3, sizeof(rule.symlink));
 263                                 valid = 1;
 264                                 continue;
 265                         }
 266
 267                         if (strcasecmp(temp2, FIELD_OWNER) == 0) {
 268                                 strlcpy(rule.owner, temp3, sizeof(rule.owner));
 269                                 valid = 1;
 270                                 continue;
 271                         }
 272
 273                         if (strcasecmp(temp2, FIELD_GROUP) == 0) {
 274                                 strlcpy(rule.group, temp3, sizeof(rule.group));
 275                                 valid = 1;
 276                                 continue;
 277                         }
 278
 279                         if (strcasecmp(temp2, FIELD_MODE) == 0) {
 280                                 rule.mode = strtol(temp3, NULL, 8);
 281                                 valid = 1;
 282                                 continue;
 283                         }
 284
 285                         if (strcasecmp(temp2, FIELD_OPTIONS) == 0) {
 286                                 if (strstr(temp3, OPTION_LAST_RULE) != NULL) {
 287                                         dbg("last rule to be applied");
 288                                         rule.last_rule = 1;
 289                                 }
 290                                 if (strstr(temp3, OPTION_IGNORE_DEVICE) != NULL) {
 291                                         dbg("device should be ignored");
 292                                         rule.ignore_device = 1;
 293                                 }
 294                                 if (strstr(temp3, OPTION_IGNORE_REMOVE) != NULL) {
 295                                         dbg("remove event should be ignored");
 296                                         rule.ignore_remove = 1;
 297                                 }
 298                                 if (strstr(temp3, OPTION_PARTITIONS) != NULL) {
 299                                         dbg("creation of partition nodes requested");
 300                                         rule.partitions = DEFAULT_PARTITIONS_COUNT;
 301                                 }
 302                                 valid = 1;
 303                                 continue;
 304                         }
 305
 306                         dbg("unknown type of field '%s'", temp2);
 307                         goto error;
 308                 }
 309
 310                 /* skip line if not any valid key was found */
 311                 if (!valid)
 312                         goto error;
 313
 314                 /* simple plausibility checks for given keys */
 315                 if ((rule.sysfs_pair[0].file[0] == '\0') ^
 316                     (rule.sysfs_pair[0].value[0] == '\0')) {
 317                         info("inconsistency in " FIELD_SYSFS " key");
 318                         goto error;
 319                 }
 320
 321                 if ((rule.result[0] != '\0') && (program_given == 0)) {
 322                         info(FIELD_RESULT " is only useful when "
 323                              FIELD_PROGRAM " is called in any rule before");
 324                         goto error;
 325                 }
 326
 327                 rule.config_line = lineno;
 328                 strlcpy(rule.config_file, filename, sizeof(rule.config_file));
 329                 retval = add_config_dev(&rule);
 330                 if (retval) {
 331                         dbg("add_config_dev returned with error %d", retval);
 332                         continue;
 333 error:
 334                         info("parse error %s, line %d:%d, rule skipped",
 335                              filename, lineno, (int) (temp - line));
 336                 }
 337         }
 338
 339         file_unmap(buf, bufsize);
 340         return retval;
 341 }
 342
 343 int udev_rules_init(void)
 344 {
 345         struct stat stats;
 346         int retval;
 347
 348         if (stat(udev_rules_filename, &stats) != 0)
 349                 return -1;
 350
 351         if ((stats.st_mode & S_IFMT) != S_IFDIR)
 352                 retval = rules_parse(NULL, udev_rules_filename);
 353         else
 354                 retval = call_foreach_file(rules_parse, NULL, udev_rules_filename, RULEFILE_SUFFIX);
 355
 356         return retval;
 357 }
 358
 359 void udev_rules_close(void)
 360 {
 361         struct udev_rule *rule;
 362         struct udev_rule *temp_rule;
 363
 364         list_for_each_entry_safe(rule, temp_rule, &udev_rule_list, node) {
 365                 list_del(&rule->node);
 366                 free(rule);
 367         }
 368 }
 369