namedev.c

   1 /*
   2  * namedev.c
   3  *
   4  * Userspace devfs
   5  *
   6  * Copyright (C) 2003 Greg Kroah-Hartman <greg@kroah.com>
   7  *
   8  *
   9  *      This program is free software; you can redistribute it and/or modify it
  10  *      under the terms of the GNU General Public License as published by the
  11  *      Free Software Foundation version 2 of the License.
  12  *
  13  *      This program is distributed in the hope that it will be useful, but
  14  *      WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  *      General Public License for more details.
  17  *
  18  *      You should have received a copy of the GNU General Public License along
  19  *      with this program; if not, write to the Free Software Foundation, Inc.,
  20  *      675 Mass Ave, Cambridge, MA 02139, USA.
  21  *
  22  */
  23
  24 #include <stddef.h>
  25 #include <stdlib.h>
  26 #include <string.h>
  27 #include <stdio.h>
  28 #include <fcntl.h>
  29 #include <ctype.h>
  30 #include <unistd.h>
  31 #include <errno.h>
  32 #include <sys/wait.h>
  33 #include <sys/stat.h>
  34
  35 #include "libsysfs/sysfs/libsysfs.h"
  36 #include "list.h"
  37 #include "udev.h"
  38 #include "udev_utils.h"
  39 #include "udev_version.h"
  40 #include "logging.h"
  41 #include "namedev.h"
  42 #include "udev_db.h"
  43
  44 static struct sysfs_attribute *find_sysfs_attribute(struct sysfs_class_device *class_dev, struct sysfs_device *sysfs_device, char *attr);
  45
  46 /* compare string with pattern (supports * ? [0-9] [!A-Z]) */
  47 static int strcmp_pattern(const char *p, const char *s)
  48 {
  49         if (s[0] == '\0') {
  50                 while (p[0] == '*')
  51                         p++;
  52                 return (p[0] != '\0');
  53         }
  54         switch (p[0]) {
  55         case '[':
  56                 {
  57                         int not = 0;
  58                         p++;
  59                         if (p[0] == '!') {
  60                                 not = 1;
  61                                 p++;
  62                         }
  63                         while ((p[0] != '\0') && (p[0] != ']')) {
  64                                 int match = 0;
  65                                 if (p[1] == '-') {
  66                                         if ((s[0] >= p[0]) && (s[0] <= p[2]))
  67                                                 match = 1;
  68                                         p += 3;
  69                                 } else {
  70                                         match = (p[0] == s[0]);
  71                                         p++;
  72                                 }
  73                                 if (match ^ not) {
  74                                         while ((p[0] != '\0') && (p[0] != ']'))
  75                                                 p++;
  76                                         if (p[0] == ']')
  77                                                 return strcmp_pattern(p+1, s+1);
  78                                 }
  79                         }
  80                 }
  81                 break;
  82         case '*':
  83                 if (strcmp_pattern(p, s+1))
  84                         return strcmp_pattern(p+1, s);
  85                 return 0;
  86         case '\0':
  87                 if (s[0] == '\0') {
  88                         return 0;
  89                 }
  90                 break;
  91         default:
  92                 if ((p[0] == s[0]) || (p[0] == '?'))
  93                         return strcmp_pattern(p+1, s+1);
  94                 break;
  95         }
  96         return 1;
  97 }
  98
  99 /* extract possible {attr} and move str behind it */
 100 static char *get_format_attribute(char **str)
 101 {
 102         char *pos;
 103         char *attr = NULL;
 104
 105         if (*str[0] == '{') {
 106                 pos = strchr(*str, '}');
 107                 if (pos == NULL) {
 108                         dbg("missing closing brace for format");
 109                         return NULL;
 110                 }
 111                 pos[0] = '\0';
 112                 attr = *str+1;
 113                 *str = pos+1;
 114                 dbg("attribute='%s', str='%s'", attr, *str);
 115         }
 116         return attr;
 117 }
 118
 119 /* extract possible format length and move str behind it*/
 120 static int get_format_len(char **str)
 121 {
 122         int num;
 123         char *tail;
 124
 125         if (isdigit(*str[0])) {
 126                 num = (int) strtoul(*str, &tail, 10);
 127                 if (num > 0) {
 128                         *str = tail;
 129                         dbg("format length=%i", num);
 130                         return num;
 131                 } else {
 132                         dbg("format parsing error '%s'", *str);
 133                 }
 134         }
 135         return -1;
 136 }
 137
 138 /** Finds the lowest positive N such that <name>N isn't present in
 139  *  $(udevroot) either as a file or a symlink.
 140  *
 141  *  @param  name                Name to check for
 142  *  @return                     0 if <name> didn't exist and N otherwise.
 143  */
 144 static int find_free_number(struct udevice *udev, const char *name)
 145 {
 146         char filename[NAME_SIZE];
 147         int num = 0;
 148         struct udevice db_udev;
 149
 150         strfieldcpy(filename, name);
 151         while (1) {
 152                 dbg("look for existing node '%s'", filename);
 153                 memset(&db_udev, 0x00, sizeof(struct udevice));
 154                 if (udev_db_get_device_byname(&db_udev, filename) != 0) {
 155                         dbg("free num=%d", num);
 156                         return num;
 157                 }
 158
 159                 num++;
 160                 if (num > 1000) {
 161                         info("find_free_number gone crazy (num=%d), aborted", num);
 162                         return -1;
 163                 }
 164                 snprintf(filename, NAME_SIZE, "%s%d", name, num);
 165                 filename[NAME_SIZE-1] = '\0';
 166         }
 167 }
 168
 169 static void apply_format(struct udevice *udev, char *string, size_t maxsize,
 170                          struct sysfs_class_device *class_dev,
 171                          struct sysfs_device *sysfs_device)
 172 {
 173         char temp[NAME_SIZE];
 174         char temp2[NAME_SIZE];
 175         char *tail;
 176         char *pos;
 177         char *attr;
 178         int len;
 179         int i;
 180         char c;
 181         char *spos;
 182         char *rest;
 183         int slen;
 184         struct sysfs_attribute *tmpattr;
 185         unsigned int next_free_number;
 186
 187         pos = string;
 188         while (1) {
 189                 pos = strchr(pos, '%');
 190                 if (pos == NULL)
 191                         break;
 192
 193                 pos[0] = '\0';
 194                 tail = pos+1;
 195                 len = get_format_len(&tail);
 196                 c = tail[0];
 197                 strfieldcpy(temp, tail+1);
 198                 tail = temp;
 199                 dbg("format=%c, string='%s', tail='%s'",c , string, tail);
 200                 attr = get_format_attribute(&tail);
 201
 202
 203                 switch (c) {
 204                 case 'b':
 205                         if (strlen(udev->bus_id) == 0)
 206                                 break;
 207                         strfieldcatmax(string, udev->bus_id, maxsize);
 208                         dbg("substitute bus_id '%s'", udev->bus_id);
 209                         break;
 210                 case 'k':
 211                         if (strlen(udev->kernel_name) == 0)
 212                                 break;
 213                         strfieldcatmax(string, udev->kernel_name, maxsize);
 214                         dbg("substitute kernel name '%s'", udev->kernel_name);
 215                         break;
 216                 case 'n':
 217                         if (strlen(udev->kernel_number) == 0)
 218                                 break;
 219                         strfieldcatmax(string, udev->kernel_number, maxsize);
 220                         dbg("substitute kernel number '%s'", udev->kernel_number);
 221                                 break;
 222                 case 'm':
 223                         strintcatmax(string, udev->minor, maxsize);
 224                         dbg("substitute minor number '%u'", udev->minor);
 225                         break;
 226                 case 'M':
 227                         strintcatmax(string, udev->major, maxsize);
 228                         dbg("substitute major number '%u'", udev->major);
 229                         break;
 230                 case 'c':
 231                         if (strlen(udev->program_result) == 0)
 232                                 break;
 233                         /* get part part of the result string */
 234                         i = 0;
 235                         if (attr != NULL)
 236                                 i = strtoul(attr, &rest, 10);
 237                         if (i > 0) {
 238                                 foreach_strpart(udev->program_result, " \n\r", spos, slen) {
 239                                         i--;
 240                                         if (i == 0)
 241                                                 break;
 242                                 }
 243                                 if (i > 0) {
 244                                         dbg("requested part of result string not found");
 245                                         break;
 246                                 }
 247                                 if (rest[0] == '+')
 248                                         strfieldcpy(temp2, spos);
 249                                 else
 250                                         strfieldcpymax(temp2, spos, slen+1);
 251                                 strfieldcatmax(string, temp2, maxsize);
 252                                 dbg("substitute part of result string '%s'", temp2);
 253                         } else {
 254                                 strfieldcatmax(string, udev->program_result, maxsize);
 255                                 dbg("substitute result string '%s'", udev->program_result);
 256                         }
 257                         break;
 258                 case 's':
 259                         if (attr != NULL) {
 260                                 tmpattr = find_sysfs_attribute(class_dev, sysfs_device, attr);
 261                                 if (tmpattr == NULL) {
 262                                         dbg("sysfa attribute '%s' not found", attr);
 263                                         break;
 264                                 }
 265                                 /* strip trailing whitespace of matching value */
 266                                 if (isspace(tmpattr->value[strlen(tmpattr->value)-1])) {
 267                                         i = len = strlen(tmpattr->value);
 268                                         while (i > 0 &&  isspace(tmpattr->value[i-1]))
 269                                                 i--;
 270                                         if (i < len) {
 271                                                 tmpattr->value[i] = '\0';
 272                                                 dbg("remove %i trailing whitespace chars from '%s'",
 273                                                          len - i, tmpattr->value);
 274                                         }
 275                                 }
 276                                 strfieldcatmax(string, tmpattr->value, maxsize);
 277                                 dbg("substitute sysfs value '%s'", tmpattr->value);
 278                         } else {
 279                                 dbg("missing attribute");
 280                         }
 281                         break;
 282                 case '%':
 283                         strfieldcatmax(string, "%", maxsize);
 284                         pos++;
 285                         break;
 286                 case 'e':
 287                         next_free_number = find_free_number(udev, string);
 288                         if (next_free_number > 0) {
 289                                 sprintf(temp2, "%d", next_free_number);
 290                                 strfieldcatmax(string, temp2, maxsize);
 291                         }
 292                         break;
 293                 default:
 294                         dbg("unknown substitution type '%%%c'", c);
 295                         break;
 296                 }
 297                 /* truncate to specified length */
 298                 if (len > 0)
 299                         pos[len] = '\0';
 300
 301                 strfieldcatmax(string, tail, maxsize);
 302         }
 303 }
 304
 305 static void fix_kernel_name(struct udevice *udev)
 306 {
 307         char *temp = udev->kernel_name;
 308
 309         while (*temp != 0x00) {
 310                 /* Some block devices have a ! in their name,
 311                  * we need to change that to / */
 312                 if (*temp == '!')
 313                         *temp = '/';
 314                 ++temp;
 315         }
 316 }
 317
 318 static int execute_program(struct udevice *udev, const char *path, char *value, int len)
 319 {
 320         int retval;
 321         int count;
 322         int status;
 323         int fds[2];
 324         pid_t pid;
 325         char *pos;
 326         char arg[PROGRAM_SIZE];
 327         char *argv[(PROGRAM_SIZE / 2) + 1];
 328         int i;
 329
 330         strfieldcpy(arg, path);
 331         i = 0;
 332         if (strchr(path, ' ')) {
 333                 pos = arg;
 334                 while (pos != NULL) {
 335                         if (pos[0] == '\'') {
 336                                 /* don't separate if in apostrophes */
 337                                 pos++;
 338                                 argv[i] = strsep(&pos, "\'");
 339                                 while (pos && pos[0] == ' ')
 340                                         pos++;
 341                         } else {
 342                                 argv[i] = strsep(&pos, " ");
 343                         }
 344                         dbg("arg[%i] '%s'", i, argv[i]);
 345                         i++;
 346                 }
 347                 argv[i] =  NULL;
 348                 dbg("execute '%s' with parsed arguments", arg);
 349         } else {
 350                 argv[0] = arg;
 351                 argv[1] = udev->subsystem;
 352                 argv[2] = NULL;
 353                 dbg("execute '%s' with subsystem '%s' argument", arg, argv[1]);
 354         }
 355
 356         retval = pipe(fds);
 357         if (retval != 0) {
 358                 dbg("pipe failed");
 359                 return -1;
 360         }
 361
 362         pid = fork();
 363         switch(pid) {
 364         case 0:
 365                 /* child */
 366                 /* dup2 write side of pipe to STDOUT */
 367                 dup2(fds[1], STDOUT_FILENO);
 368                 retval = execv(arg, argv);
 369
 370                 info(FIELD_PROGRAM " execution of '%s' failed", path);
 371                 exit(1);
 372         case -1:
 373                 dbg("fork failed");
 374                 return -1;
 375         default:
 376                 /* parent reads from fds[0] */
 377                 close(fds[1]);
 378                 retval = 0;
 379                 i = 0;
 380                 while (1) {
 381                         count = read(fds[0], value + i, len - i-1);
 382                         if (count <= 0)
 383                                 break;
 384
 385                         i += count;
 386                         if (i >= len-1) {
 387                                 dbg("result len %d too short", len);
 388                                 retval = -1;
 389                                 break;
 390                         }
 391                 }
 392
 393                 if (count < 0) {
 394                         dbg("read failed with '%s'", strerror(errno));
 395                         retval = -1;
 396                 }
 397
 398                 if (i > 0 && value[i-1] == '\n')
 399                         i--;
 400                 value[i] = '\0';
 401                 dbg("result is '%s'", value);
 402
 403                 close(fds[0]);
 404                 waitpid(pid, &status, 0);
 405
 406                 if (!WIFEXITED(status) || (WEXITSTATUS(status) != 0)) {
 407                         dbg("exec program status 0x%x", status);
 408                         retval = -1;
 409                 }
 410         }
 411         return retval;
 412 }
 413
 414 static struct sysfs_attribute *find_sysfs_attribute(struct sysfs_class_device *class_dev, struct sysfs_device *sysfs_device, char *attr)
 415 {
 416         struct sysfs_attribute *tmpattr = NULL;
 417         char *c;
 418
 419         dbg("look for device attribute '%s'", attr);
 420         /* try to find the attribute in the class device directory */
 421         tmpattr = sysfs_get_classdev_attr(class_dev, attr);
 422         if (tmpattr)
 423                 goto attr_found;
 424
 425         /* look in the class device directory if present */
 426         if (sysfs_device) {
 427                 tmpattr = sysfs_get_device_attr(sysfs_device, attr);
 428                 if (tmpattr)
 429                         goto attr_found;
 430         }
 431
 432         return NULL;
 433
 434 attr_found:
 435         c = strchr(tmpattr->value, '\n');
 436         if (c != NULL)
 437                 c[0] = '\0';
 438
 439         dbg("found attribute '%s'", tmpattr->path);
 440         return tmpattr;
 441 }
 442
 443 static int compare_sysfs_attribute(struct sysfs_class_device *class_dev, struct sysfs_device *sysfs_device, struct sysfs_pair *pair)
 444 {
 445         struct sysfs_attribute *tmpattr;
 446         int i;
 447         int len;
 448
 449         if ((pair == NULL) || (pair->file[0] == '\0') || (pair->value == '\0'))
 450                 return -ENODEV;
 451
 452         tmpattr = find_sysfs_attribute(class_dev, sysfs_device, pair->file);
 453         if (tmpattr == NULL)
 454                 return -ENODEV;
 455
 456         /* strip trailing whitespace of value, if not asked to match for it */
 457         if (! isspace(pair->value[strlen(pair->value)-1])) {
 458                 i = len = strlen(tmpattr->value);
 459                 while (i > 0 &&  isspace(tmpattr->value[i-1]))
 460                         i--;
 461                 if (i < len) {
 462                         tmpattr->value[i] = '\0';
 463                         dbg("remove %i trailing whitespace chars from '%s'",
 464                             len - i, tmpattr->value);
 465                 }
 466         }
 467
 468         dbg("compare attribute '%s' value '%s' with '%s'",
 469                   pair->file, tmpattr->value, pair->value);
 470         if (strcmp_pattern(pair->value, tmpattr->value) != 0)
 471                 return -ENODEV;
 472
 473         dbg("found matching attribute '%s' with value '%s'",
 474             pair->file, pair->value);
 475         return 0;
 476 }
 477
 478 static int match_sysfs_pairs(struct config_device *dev, struct sysfs_class_device *class_dev, struct sysfs_device *sysfs_device)
 479 {
 480         struct sysfs_pair *pair;
 481         int i;
 482
 483         for (i = 0; i < MAX_SYSFS_PAIRS; ++i) {
 484                 pair = &dev->sysfs_pair[i];
 485                 if ((pair->file[0] == '\0') || (pair->value[0] == '\0'))
 486                         break;
 487                 if (compare_sysfs_attribute(class_dev, sysfs_device, pair) != 0) {
 488                         dbg("sysfs attribute doesn't match");
 489                         return -ENODEV;
 490                 }
 491         }
 492
 493         return 0;
 494 }
 495
 496 static int match_id(struct config_device *dev, struct sysfs_class_device *class_dev, struct sysfs_device *sysfs_device)
 497 {
 498         char path[SYSFS_PATH_MAX];
 499         char *temp = NULL;
 500
 501         /* we have to have a sysfs device for ID to work */
 502         if (!sysfs_device)
 503                 return -ENODEV;
 504
 505         strfieldcpy(path, sysfs_device->path);
 506         temp = strrchr(path, '/');
 507         temp++;
 508         dbg("search '%s' in '%s', path='%s'", dev->id, temp, path);
 509         if (strcmp_pattern(dev->id, temp) != 0)
 510                 return -ENODEV;
 511         else
 512                 return 0;
 513 }
 514
 515 static int match_place(struct config_device *dev, struct sysfs_class_device *class_dev, struct sysfs_device *sysfs_device)
 516 {
 517         char path[SYSFS_PATH_MAX];
 518         int found;
 519         char *temp = NULL;
 520
 521         /* we have to have a sysfs device for PLACE to work */
 522         if (!sysfs_device)
 523                 return -ENODEV;
 524
 525         found = 0;
 526         strfieldcpy(path, sysfs_device->path);
 527         temp = strrchr(path, '/');
 528         dbg("search '%s' in '%s', path='%s'", dev->place, temp, path);
 529         if (strstr(temp, dev->place) != NULL) {
 530                 found = 1;
 531         } else {
 532                 *temp = 0x00;
 533                 temp = strrchr(path, '/');
 534                 dbg("search '%s' in '%s', path='%s'", dev->place, temp, path);
 535                 if (strstr(temp, dev->place) != NULL)
 536                         found = 1;
 537         }
 538         if (!found) {
 539                 dbg("place doesn't match");
 540                 return -ENODEV;
 541         }
 542
 543         return 0;
 544 }
 545
 546 static int match_rule(struct udevice *udev, struct config_device *dev,
 547                       struct sysfs_class_device *class_dev, struct sysfs_device *sysfs_device)
 548 {
 549         while (1) {
 550                 /* check for matching bus value */
 551                 if (dev->bus[0] != '\0') {
 552                         if (sysfs_device == NULL) {
 553                                 dbg("device has no bus");
 554                                 goto try_parent;
 555                         }
 556                         dbg("check for " FIELD_BUS " dev->bus='%s' sysfs_device->bus='%s'",
 557                             dev->bus, sysfs_device->bus);
 558                         if (strcmp_pattern(dev->bus, sysfs_device->bus) != 0) {
 559                                 dbg(FIELD_BUS " is not matching");
 560                                 goto try_parent;
 561                         } else {
 562                                 dbg(FIELD_BUS " matches");
 563                         }
 564                 }
 565
 566                 /* check for matching kernel name */
 567                 if (dev->kernel[0] != '\0') {
 568                         dbg("check for " FIELD_KERNEL " dev->kernel='%s' class_dev->name='%s'",
 569                             dev->kernel, class_dev->name);
 570                         if (strcmp_pattern(dev->kernel, class_dev->name) != 0) {
 571                                 dbg(FIELD_KERNEL " is not matching");
 572                                 goto try_parent;
 573                         } else {
 574                                 dbg(FIELD_KERNEL " matches");
 575                         }
 576                 }
 577
 578                 /* check for matching subsystem */
 579                 if (dev->subsystem[0] != '\0') {
 580                         dbg("check for " FIELD_SUBSYSTEM " dev->subsystem='%s' class_dev->name='%s'",
 581                             dev->subsystem, class_dev->name);
 582                         if (strcmp_pattern(dev->subsystem, udev->subsystem) != 0) {
 583                                 dbg(FIELD_SUBSYSTEM " is not matching");
 584                                 goto try_parent;
 585                         } else {
 586                                 dbg(FIELD_SUBSYSTEM " matches");
 587                         }
 588                 }
 589
 590                 /* check for matching driver */
 591                 if (dev->driver[0] != '\0') {
 592                         dbg("check for " FIELD_DRIVER " dev->driver='%s' sysfs_device->driver_name='%s'",
 593                             dev->driver, sysfs_device->driver_name);
 594                         if (strcmp_pattern(dev->driver, sysfs_device->driver_name) != 0) {
 595                                 dbg(FIELD_DRIVER " is not matching");
 596                                 goto try_parent;
 597                         } else {
 598                                 dbg(FIELD_DRIVER " matches");
 599                         }
 600                 }
 601
 602                 /* check for matching bus id */
 603                 if (dev->id[0] != '\0') {
 604                         dbg("check " FIELD_ID);
 605                         if (match_id(dev, class_dev, sysfs_device) != 0) {
 606                                 dbg(FIELD_ID " is not matching");
 607                                 goto try_parent;
 608                         } else {
 609                                 dbg(FIELD_ID " matches");
 610                         }
 611                 }
 612
 613                 /* check for matching place of device */
 614                 if (dev->place[0] != '\0') {
 615                         dbg("check " FIELD_PLACE);
 616                         if (match_place(dev, class_dev, sysfs_device) != 0) {
 617                                 dbg(FIELD_PLACE " is not matching");
 618                                 goto try_parent;
 619                         } else {
 620                                 dbg(FIELD_PLACE " matches");
 621                         }
 622                 }
 623
 624                 /* check for matching sysfs pairs */
 625                 if (dev->sysfs_pair[0].file[0] != '\0') {
 626                         dbg("check " FIELD_SYSFS " pairs");
 627                         if (match_sysfs_pairs(dev, class_dev, sysfs_device) != 0) {
 628                                 dbg(FIELD_SYSFS " is not matching");
 629                                 goto try_parent;
 630                         } else {
 631                                 dbg(FIELD_SYSFS " matches");
 632                         }
 633                 }
 634
 635                 /* execute external program */
 636                 if (dev->program[0] != '\0') {
 637                         char program[PROGRAM_SIZE];
 638
 639                         dbg("check " FIELD_PROGRAM);
 640                         strfieldcpy(program, dev->program);
 641                         apply_format(udev, program, sizeof(program), class_dev, sysfs_device);
 642                         if (execute_program(udev, program, udev->program_result, NAME_SIZE) != 0) {
 643                                 dbg(FIELD_PROGRAM " returned nonzero");
 644                                 goto try_parent;
 645                         } else {
 646                                 dbg(FIELD_PROGRAM " returned successful");
 647                         }
 648                 }
 649
 650                 /* check for matching result of external program */
 651                 if (dev->result[0] != '\0') {
 652                         dbg("check for " FIELD_RESULT " dev->result='%s', udev->program_result='%s'",
 653                             dev->result, udev->program_result);
 654                         if (strcmp_pattern(dev->result, udev->program_result) != 0) {
 655                                 dbg(FIELD_RESULT " is not matching");
 656                                 goto try_parent;
 657                         } else {
 658                                 dbg(FIELD_RESULT " matches");
 659                         }
 660                 }
 661
 662                 /* Yeah, we matched! */
 663                 return 0;
 664
 665 try_parent:
 666                 dbg("try parent sysfs device");
 667                 sysfs_device = sysfs_get_device_parent(sysfs_device);
 668                 if (sysfs_device == NULL)
 669                         return -ENODEV;
 670                 dbg("sysfs_device->path='%s'", sysfs_device->path);
 671                 dbg("sysfs_device->bus_id='%s'", sysfs_device->bus_id);
 672         }
 673
 674 }
 675
 676 int namedev_name_device(struct udevice *udev, struct sysfs_class_device *class_dev)
 677 {
 678         struct sysfs_class_device *class_dev_parent;
 679         struct sysfs_device *sysfs_device = NULL;
 680         struct config_device *dev;
 681         char *pos;
 682
 683         dbg("class_dev->name='%s'", class_dev->name);
 684
 685         /* Figure out where the "device"-symlink is at.  For char devices this will
 686          * always be in the class_dev->path.  On block devices, only the main block
 687          * device will have the device symlink in it's path. All partition devices
 688          * need to look at the symlink in its parent directory.
 689          */
 690         class_dev_parent = sysfs_get_classdev_parent(class_dev);
 691         if (class_dev_parent != NULL) {
 692                 dbg("given class device has a parent, use this instead");
 693                 sysfs_device = sysfs_get_classdev_device(class_dev_parent);
 694         } else {
 695                 sysfs_device = sysfs_get_classdev_device(class_dev);
 696         }
 697
 698         if (sysfs_device) {
 699                 dbg("found devices device: path='%s', bus_id='%s', bus='%s'",
 700                     sysfs_device->path, sysfs_device->bus_id, sysfs_device->bus);
 701                 strfieldcpy(udev->bus_id, sysfs_device->bus_id);
 702         }
 703
 704         strfieldcpy(udev->kernel_name, class_dev->name);
 705         fix_kernel_name(udev);
 706         dbg("udev->kernel_name = '%s'", udev->kernel_name);
 707
 708         /* get kernel number */
 709         pos = class_dev->name + strlen(class_dev->name);
 710         while (isdigit(*(pos-1)))
 711                 pos--;
 712         strfieldcpy(udev->kernel_number, pos);
 713         dbg("kernel_number='%s'", udev->kernel_number);
 714
 715         /* look for a matching rule to apply */
 716         list_for_each_entry(dev, &config_device_list, node) {
 717                 dbg("process rule");
 718                 if (match_rule(udev, dev, class_dev, sysfs_device) == 0) {
 719                         if (dev->name[0] == '\0' && dev->symlink[0] == '\0') {
 720                                 /* empty name, symlink, perms will not create any node */
 721                                 if (dev->mode == 0000 && dev->owner[0] == '\0' && dev->group[0] == '\0') {
 722                                         info("configured rule in '%s[%i]' applied, '%s' is ignored",
 723                                              dev->config_file, dev->config_line, udev->kernel_name);
 724                                         return -1;
 725                                 }
 726
 727                                 /* apply permissions only rule values */
 728                                 if (dev->mode != 0000) {
 729                                         udev->mode = dev->mode;
 730                                         dbg("applied mode=%#o to '%s'", udev->mode, udev->kernel_name);
 731                                 }
 732                                 if (dev->owner[0] != '\0') {
 733                                         strfieldcpy(udev->owner, dev->owner);
 734                                         apply_format(udev, udev->owner, sizeof(udev->owner), class_dev, sysfs_device);
 735                                         dbg("applied owner='%s' to '%s'", udev->owner, udev->kernel_name);
 736                                 }
 737                                 if (dev->group[0] != '\0') {
 738                                         strfieldcpy(udev->group, dev->group);
 739                                         apply_format(udev, udev->group, sizeof(udev->group), class_dev, sysfs_device);
 740                                         dbg("applied group='%s' to '%s'", udev->group, udev->kernel_name);
 741                                 }
 742                         }
 743
 744                         /* collect symlinks for the final matching rule */
 745                         if (dev->symlink[0] != '\0') {
 746                                 char temp[NAME_SIZE];
 747
 748                                 info("configured rule in '%s[%i]' applied, added symlink '%s'",
 749                                      dev->config_file, dev->config_line, dev->symlink);
 750                                 strfieldcpy(temp, dev->symlink);
 751                                 apply_format(udev, temp, sizeof(temp), class_dev, sysfs_device);
 752                                 if (udev->symlink[0] != '\0')
 753                                         strfieldcat(udev->symlink, " ");
 754                                 strfieldcat(udev->symlink, temp);
 755                         }
 756
 757                         /* rule matches */
 758                         if (dev->name[0] != '\0') {
 759                                 /* apply all_partitions flag only at a main block device */
 760                                 if (dev->partitions > 0 &&
 761                                     (udev->type != 'b' || udev->kernel_number[0] != '\0'))
 762                                         continue;
 763
 764                                 info("configured rule in '%s[%i]' applied, '%s' becomes '%s'",
 765                                      dev->config_file, dev->config_line, udev->kernel_name, dev->name);
 766
 767                                 strfieldcpy(udev->name, dev->name);
 768                                 apply_format(udev, udev->name, sizeof(udev->name), class_dev, sysfs_device);
 769                                 strfieldcpy(udev->config_file, dev->config_file);
 770                                 udev->config_line = dev->config_line;
 771                                 udev->ignore_remove = dev->ignore_remove;
 772
 773                                 if (udev->type == 'n')
 774                                         goto exit;
 775
 776                                 udev->partitions = dev->partitions;
 777                                 if (dev->mode != 0000)
 778                                         udev->mode = dev->mode;
 779                                 if (dev->owner[0] != '\0') {
 780                                         strfieldcpy(udev->owner, dev->owner);
 781                                         apply_format(udev, udev->owner, sizeof(udev->owner), class_dev, sysfs_device);
 782                                 }
 783                                 if (dev->group[0] != '\0') {
 784                                         strfieldcpy(udev->group, dev->group);
 785                                         apply_format(udev, udev->group, sizeof(udev->group), class_dev, sysfs_device);
 786                                 }
 787
 788                                 dbg("name, '%s' is going to have owner='%s', group='%s', mode = %#o",
 789                                     udev->name, udev->owner, udev->group, udev->mode);
 790
 791                                 goto exit;
 792                         }
 793                 }
 794         }
 795
 796         /* no rule matched, so we use the kernel name */
 797         strfieldcpy(udev->name, udev->kernel_name);
 798         dbg("no rule found, use kernel name '%s'", udev->name);
 799
 800 exit:
 801         return 0;
 802 }