chiark / gitweb /
[PATCH] namedev: if SUBSYSTEM or KERNEL key doesn't match, give up immediately
[elogind.git] / 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         struct sysfs_class_device *class_dev_parent;
187
188         pos = string;
189         while (1) {
190                 pos = strchr(pos, '%');
191                 if (pos == NULL)
192                         break;
193
194                 pos[0] = '\0';
195                 tail = pos+1;
196                 len = get_format_len(&tail);
197                 c = tail[0];
198                 strfieldcpy(temp, tail+1);
199                 tail = temp;
200                 dbg("format=%c, string='%s', tail='%s'",c , string, tail);
201                 attr = get_format_attribute(&tail);
202
203
204                 switch (c) {
205                 case 'p':
206                         if (strlen(udev->devpath) == 0)
207                                 break;
208                         strfieldcatmax(string, udev->devpath, maxsize);
209                         dbg("substitute kernel name '%s'", udev->kernel_name);
210                         break;
211                 case 'b':
212                         if (strlen(udev->bus_id) == 0)
213                                 break;
214                         strfieldcatmax(string, udev->bus_id, maxsize);
215                         dbg("substitute bus_id '%s'", udev->bus_id);
216                         break;
217                 case 'k':
218                         if (strlen(udev->kernel_name) == 0)
219                                 break;
220                         strfieldcatmax(string, udev->kernel_name, maxsize);
221                         dbg("substitute kernel name '%s'", udev->kernel_name);
222                         break;
223                 case 'n':
224                         if (strlen(udev->kernel_number) == 0)
225                                 break;
226                         strfieldcatmax(string, udev->kernel_number, maxsize);
227                         dbg("substitute kernel number '%s'", udev->kernel_number);
228                                 break;
229                 case 'm':
230                         strintcatmax(string, udev->minor, maxsize);
231                         dbg("substitute minor number '%u'", udev->minor);
232                         break;
233                 case 'M':
234                         strintcatmax(string, udev->major, maxsize);
235                         dbg("substitute major number '%u'", udev->major);
236                         break;
237                 case 'c':
238                         if (strlen(udev->program_result) == 0)
239                                 break;
240                         /* get part part of the result string */
241                         i = 0;
242                         if (attr != NULL)
243                                 i = strtoul(attr, &rest, 10);
244                         if (i > 0) {
245                                 foreach_strpart(udev->program_result, " \n\r", spos, slen) {
246                                         i--;
247                                         if (i == 0)
248                                                 break;
249                                 }
250                                 if (i > 0) {
251                                         dbg("requested part of result string not found");
252                                         break;
253                                 }
254                                 if (rest[0] == '+')
255                                         strfieldcpy(temp2, spos);
256                                 else
257                                         strfieldcpymax(temp2, spos, slen+1);
258                                 strfieldcatmax(string, temp2, maxsize);
259                                 dbg("substitute part of result string '%s'", temp2);
260                         } else {
261                                 strfieldcatmax(string, udev->program_result, maxsize);
262                                 dbg("substitute result string '%s'", udev->program_result);
263                         }
264                         break;
265                 case 's':
266                         if (attr != NULL) {
267                                 tmpattr = find_sysfs_attribute(class_dev, sysfs_device, attr);
268                                 if (tmpattr == NULL) {
269                                         dbg("sysfa attribute '%s' not found", attr);
270                                         break;
271                                 }
272                                 /* strip trailing whitespace of matching value */
273                                 if (isspace(tmpattr->value[strlen(tmpattr->value)-1])) {
274                                         i = len = strlen(tmpattr->value);
275                                         while (i > 0 &&  isspace(tmpattr->value[i-1]))
276                                                 i--;
277                                         if (i < len) {
278                                                 tmpattr->value[i] = '\0';
279                                                 dbg("remove %i trailing whitespace chars from '%s'",
280                                                          len - i, tmpattr->value);
281                                         }
282                                 }
283                                 strfieldcatmax(string, tmpattr->value, maxsize);
284                                 dbg("substitute sysfs value '%s'", tmpattr->value);
285                         } else {
286                                 dbg("missing attribute");
287                         }
288                         break;
289                 case '%':
290                         strfieldcatmax(string, "%", maxsize);
291                         pos++;
292                         break;
293                 case 'e':
294                         next_free_number = find_free_number(udev, string);
295                         if (next_free_number > 0) {
296                                 sprintf(temp2, "%d", next_free_number);
297                                 strfieldcatmax(string, temp2, maxsize);
298                         }
299                         break;
300                 case 'P':
301                         class_dev_parent = sysfs_get_classdev_parent(class_dev);
302                         if (class_dev_parent != NULL) {
303                                 struct udevice udev_parent;
304
305                                 dbg("found parent '%s', get the node name", class_dev_parent->path);
306                                 memset(&udev_parent, 0x00, sizeof(struct udevice));
307                                 /* lookup the name in the udev_db with the DEVPATH of the parent */
308                                 strfieldcpy(udev_parent.devpath, &class_dev_parent->path[strlen(sysfs_path)]);
309                                 if (udev_db_get_device(&udev_parent) == 0) {
310                                         strfieldcatmax(string, udev_parent.name, maxsize);
311                                         dbg("substitute parent node name'%s'", udev_parent.name);
312                                 } else
313                                         dbg("parent not found in database");
314                         }
315                         break;
316                 case 'N':
317                         if (udev->tmp_node[0] == '\0') {
318                                 dbg("create temporary device node for callout");
319                                 snprintf(udev->tmp_node, NAME_SIZE-1, "%s/.tmp-%u-%u", udev_root, udev->major, udev->minor);
320                                 udev_make_node(udev, udev->tmp_node, udev->major, udev->minor, 0600, 0, 0);
321                         }
322                         strfieldcatmax(string, udev->tmp_node, maxsize);
323                         dbg("substitute temporary device node name '%s'", udev->tmp_node);
324                         break;
325                 case 'r':
326                         strfieldcatmax(string, udev_root, maxsize);
327                         dbg("substitute udev_root '%s'", udev_root);
328                         break;
329                 default:
330                         dbg("unknown substitution type '%%%c'", c);
331                         break;
332                 }
333                 /* truncate to specified length */
334                 if (len > 0)
335                         pos[len] = '\0';
336
337                 strfieldcatmax(string, tail, maxsize);
338         }
339 }
340
341 static void fix_kernel_name(struct udevice *udev)
342 {
343         char *temp = udev->kernel_name;
344
345         while (*temp != 0x00) {
346                 /* Some block devices have a ! in their name, 
347                  * we need to change that to / */
348                 if (*temp == '!')
349                         *temp = '/';
350                 ++temp;
351         }
352 }
353
354 static int execute_program(struct udevice *udev, const char *path, char *value, int len)
355 {
356         int retval;
357         int count;
358         int status;
359         int fds[2];
360         pid_t pid;
361         char *pos;
362         char arg[PROGRAM_SIZE];
363         char *argv[(PROGRAM_SIZE / 2) + 1];
364         int i;
365
366         strfieldcpy(arg, path);
367         i = 0;
368         if (strchr(path, ' ')) {
369                 pos = arg;
370                 while (pos != NULL) {
371                         if (pos[0] == '\'') {
372                                 /* don't separate if in apostrophes */
373                                 pos++;
374                                 argv[i] = strsep(&pos, "\'");
375                                 while (pos && pos[0] == ' ')
376                                         pos++;
377                         } else {
378                                 argv[i] = strsep(&pos, " ");
379                         }
380                         dbg("arg[%i] '%s'", i, argv[i]);
381                         i++;
382                 }
383                 argv[i] =  NULL;
384                 dbg("execute '%s' with parsed arguments", arg);
385         } else {
386                 argv[0] = arg;
387                 argv[1] = udev->subsystem;
388                 argv[2] = NULL;
389                 dbg("execute '%s' with subsystem '%s' argument", arg, argv[1]);
390         }
391
392         retval = pipe(fds);
393         if (retval != 0) {
394                 dbg("pipe failed");
395                 return -1;
396         }
397
398         pid = fork();
399         switch(pid) {
400         case 0:
401                 /* child */
402                 /* dup2 write side of pipe to STDOUT */
403                 dup2(fds[1], STDOUT_FILENO);
404                 retval = execv(arg, argv);
405
406                 info(FIELD_PROGRAM " execution of '%s' failed", path);
407                 exit(1);
408         case -1:
409                 dbg("fork failed");
410                 return -1;
411         default:
412                 /* parent reads from fds[0] */
413                 close(fds[1]);
414                 retval = 0;
415                 i = 0;
416                 while (1) {
417                         count = read(fds[0], value + i, len - i-1);
418                         if (count <= 0)
419                                 break;
420
421                         i += count;
422                         if (i >= len-1) {
423                                 dbg("result len %d too short", len);
424                                 retval = -1;
425                                 break;
426                         }
427                 }
428
429                 if (count < 0) {
430                         dbg("read failed with '%s'", strerror(errno));
431                         retval = -1;
432                 }
433
434                 if (i > 0 && value[i-1] == '\n')
435                         i--;
436                 value[i] = '\0';
437                 dbg("result is '%s'", value);
438
439                 close(fds[0]);
440                 waitpid(pid, &status, 0);
441
442                 if (!WIFEXITED(status) || (WEXITSTATUS(status) != 0)) {
443                         dbg("exec program status 0x%x", status);
444                         retval = -1;
445                 }
446         }
447         return retval;
448 }
449
450 static struct sysfs_attribute *find_sysfs_attribute(struct sysfs_class_device *class_dev, struct sysfs_device *sysfs_device, char *attr)
451 {
452         struct sysfs_attribute *tmpattr = NULL;
453         char *c;
454
455         dbg("look for device attribute '%s'", attr);
456         /* try to find the attribute in the class device directory */
457         tmpattr = sysfs_get_classdev_attr(class_dev, attr);
458         if (tmpattr)
459                 goto attr_found;
460
461         /* look in the class device directory if present */
462         if (sysfs_device) {
463                 tmpattr = sysfs_get_device_attr(sysfs_device, attr);
464                 if (tmpattr)
465                         goto attr_found;
466         }
467
468         return NULL;
469
470 attr_found:
471         c = strchr(tmpattr->value, '\n');
472         if (c != NULL)
473                 c[0] = '\0';
474
475         dbg("found attribute '%s'", tmpattr->path);
476         return tmpattr;
477 }
478
479 static int compare_sysfs_attribute(struct sysfs_class_device *class_dev, struct sysfs_device *sysfs_device, struct sysfs_pair *pair)
480 {
481         struct sysfs_attribute *tmpattr;
482         int i;
483         int len;
484
485         if ((pair == NULL) || (pair->file[0] == '\0') || (pair->value == '\0'))
486                 return -ENODEV;
487
488         tmpattr = find_sysfs_attribute(class_dev, sysfs_device, pair->file);
489         if (tmpattr == NULL)
490                 return -ENODEV;
491
492         /* strip trailing whitespace of value, if not asked to match for it */
493         if (! isspace(pair->value[strlen(pair->value)-1])) {
494                 i = len = strlen(tmpattr->value);
495                 while (i > 0 &&  isspace(tmpattr->value[i-1]))
496                         i--;
497                 if (i < len) {
498                         tmpattr->value[i] = '\0';
499                         dbg("remove %i trailing whitespace chars from '%s'",
500                             len - i, tmpattr->value);
501                 }
502         }
503
504         dbg("compare attribute '%s' value '%s' with '%s'",
505                   pair->file, tmpattr->value, pair->value);
506         if (strcmp_pattern(pair->value, tmpattr->value) != 0)
507                 return -ENODEV;
508
509         dbg("found matching attribute '%s' with value '%s'",
510             pair->file, pair->value);
511         return 0;
512 }
513
514 static int match_sysfs_pairs(struct config_device *dev, struct sysfs_class_device *class_dev, struct sysfs_device *sysfs_device)
515 {
516         struct sysfs_pair *pair;
517         int i;
518
519         for (i = 0; i < MAX_SYSFS_PAIRS; ++i) {
520                 pair = &dev->sysfs_pair[i];
521                 if ((pair->file[0] == '\0') || (pair->value[0] == '\0'))
522                         break;
523                 if (compare_sysfs_attribute(class_dev, sysfs_device, pair) != 0) {
524                         dbg("sysfs attribute doesn't match");
525                         return -ENODEV;
526                 }
527         }
528
529         return 0;
530 }
531
532 static int match_id(struct config_device *dev, struct sysfs_class_device *class_dev, struct sysfs_device *sysfs_device)
533 {
534         char path[SYSFS_PATH_MAX];
535         char *temp = NULL;
536
537         /* we have to have a sysfs device for ID to work */
538         if (!sysfs_device)
539                 return -ENODEV;
540
541         strfieldcpy(path, sysfs_device->path);
542         temp = strrchr(path, '/');
543         temp++;
544         dbg("search '%s' in '%s', path='%s'", dev->id, temp, path);
545         if (strcmp_pattern(dev->id, temp) != 0)
546                 return -ENODEV;
547         else
548                 return 0;
549 }
550
551 static int match_place(struct config_device *dev, struct sysfs_class_device *class_dev, struct sysfs_device *sysfs_device)
552 {
553         char path[SYSFS_PATH_MAX];
554         int found;
555         char *temp = NULL;
556
557         /* we have to have a sysfs device for PLACE to work */
558         if (!sysfs_device)
559                 return -ENODEV;
560
561         found = 0;
562         strfieldcpy(path, sysfs_device->path);
563         temp = strrchr(path, '/');
564         dbg("search '%s' in '%s', path='%s'", dev->place, temp, path);
565         if (strstr(temp, dev->place) != NULL) {
566                 found = 1;
567         } else {
568                 *temp = 0x00;
569                 temp = strrchr(path, '/');
570                 dbg("search '%s' in '%s', path='%s'", dev->place, temp, path);
571                 if (strstr(temp, dev->place) != NULL)
572                         found = 1;
573         }
574         if (!found) {
575                 dbg("place doesn't match");
576                 return -ENODEV;
577         }
578
579         return 0;
580 }
581
582 static int match_rule(struct udevice *udev, struct config_device *dev,
583                       struct sysfs_class_device *class_dev, struct sysfs_device *sysfs_device)
584 {
585         while (1) {
586                 /* check for matching kernel name */
587                 if (dev->kernel[0] != '\0') {
588                         dbg("check for " FIELD_KERNEL " dev->kernel='%s' class_dev->name='%s'",
589                             dev->kernel, class_dev->name);
590                         if (strcmp_pattern(dev->kernel, class_dev->name) != 0) {
591                                 dbg(FIELD_KERNEL " is not matching");
592                                 goto exit;
593                         }
594                         dbg(FIELD_KERNEL " matches");
595                 }
596
597                 /* check for matching subsystem */
598                 if (dev->subsystem[0] != '\0') {
599                         dbg("check for " FIELD_SUBSYSTEM " dev->subsystem='%s' class_dev->name='%s'",
600                             dev->subsystem, class_dev->name);
601                         if (strcmp_pattern(dev->subsystem, udev->subsystem) != 0) {
602                                 dbg(FIELD_SUBSYSTEM " is not matching");
603                                 goto exit;
604                         }
605                         dbg(FIELD_SUBSYSTEM " matches");
606                 }
607
608                 /* check for matching driver */
609                 if (dev->driver[0] != '\0') {
610                         dbg("check for " FIELD_DRIVER " dev->driver='%s' sysfs_device->driver_name='%s'",
611                             dev->driver, sysfs_device->driver_name);
612                         if (strcmp_pattern(dev->driver, sysfs_device->driver_name) != 0) {
613                                 dbg(FIELD_DRIVER " is not matching");
614                                 goto try_parent;
615                         } else {
616                                 dbg(FIELD_DRIVER " matches");
617                         }
618                 }
619
620                 /* check for matching bus value */
621                 if (dev->bus[0] != '\0') {
622                         if (sysfs_device == NULL) {
623                                 dbg("device has no bus");
624                                 goto try_parent;
625                         }
626                         dbg("check for " FIELD_BUS " dev->bus='%s' sysfs_device->bus='%s'",
627                             dev->bus, sysfs_device->bus);
628                         if (strcmp_pattern(dev->bus, sysfs_device->bus) != 0) {
629                                 dbg(FIELD_BUS " is not matching");
630                                 goto try_parent;
631                         }
632                         dbg(FIELD_BUS " matches");
633                 }
634
635                 /* check for matching bus id */
636                 if (dev->id[0] != '\0') {
637                         dbg("check " FIELD_ID);
638                         if (match_id(dev, class_dev, sysfs_device) != 0) {
639                                 dbg(FIELD_ID " is not matching");
640                                 goto try_parent;
641                         } else {
642                                 dbg(FIELD_ID " matches");
643                         }
644                 }
645
646                 /* check for matching place of device */
647                 if (dev->place[0] != '\0') {
648                         dbg("check " FIELD_PLACE);
649                         if (match_place(dev, class_dev, sysfs_device) != 0) {
650                                 dbg(FIELD_PLACE " is not matching");
651                                 goto try_parent;
652                         } else {
653                                 dbg(FIELD_PLACE " matches");
654                         }
655                 }
656
657                 /* check for matching sysfs pairs */
658                 if (dev->sysfs_pair[0].file[0] != '\0') {
659                         dbg("check " FIELD_SYSFS " pairs");
660                         if (match_sysfs_pairs(dev, class_dev, sysfs_device) != 0) {
661                                 dbg(FIELD_SYSFS " is not matching");
662                                 goto try_parent;
663                         } else {
664                                 dbg(FIELD_SYSFS " matches");
665                         }
666                 }
667
668                 /* execute external program */
669                 if (dev->program[0] != '\0') {
670                         char program[PROGRAM_SIZE];
671
672                         dbg("check " FIELD_PROGRAM);
673                         strfieldcpy(program, dev->program);
674                         apply_format(udev, program, sizeof(program), class_dev, sysfs_device);
675                         if (execute_program(udev, program, udev->program_result, NAME_SIZE) != 0) {
676                                 dbg(FIELD_PROGRAM " returned nonzero");
677                                 goto try_parent;
678                         } else {
679                                 dbg(FIELD_PROGRAM " returned successful");
680                         }
681                 }
682
683                 /* check for matching result of external program */
684                 if (dev->result[0] != '\0') {
685                         dbg("check for " FIELD_RESULT " dev->result='%s', udev->program_result='%s'",
686                             dev->result, udev->program_result);
687                         if (strcmp_pattern(dev->result, udev->program_result) != 0) {
688                                 dbg(FIELD_RESULT " is not matching");
689                                 goto try_parent;
690                         } else {
691                                 dbg(FIELD_RESULT " matches");
692                         }
693                 }
694
695                 /* we matched */
696                 return 0;
697
698 try_parent:
699                 dbg("try parent sysfs device");
700                 sysfs_device = sysfs_get_device_parent(sysfs_device);
701                 if (sysfs_device == NULL)
702                         goto exit;
703                 dbg("sysfs_device->path='%s'", sysfs_device->path);
704                 dbg("sysfs_device->bus_id='%s'", sysfs_device->bus_id);
705         }
706
707 exit:
708         return -1;
709 }
710
711 int namedev_name_device(struct udevice *udev, struct sysfs_class_device *class_dev)
712 {
713         struct sysfs_class_device *class_dev_parent;
714         struct sysfs_device *sysfs_device = NULL;
715         struct config_device *dev;
716         char *pos;
717
718         dbg("class_dev->name='%s'", class_dev->name);
719
720         /* Figure out where the "device"-symlink is at.  For char devices this will
721          * always be in the class_dev->path.  On block devices, only the main block
722          * device will have the device symlink in it's path. All partition devices
723          * need to look at the symlink in its parent directory.
724          */
725         class_dev_parent = sysfs_get_classdev_parent(class_dev);
726         if (class_dev_parent != NULL) {
727                 dbg("given class device has a parent, use this instead");
728                 sysfs_device = sysfs_get_classdev_device(class_dev_parent);
729         } else {
730                 sysfs_device = sysfs_get_classdev_device(class_dev);
731         }
732
733         if (sysfs_device) {
734                 dbg("found devices device: path='%s', bus_id='%s', bus='%s'",
735                     sysfs_device->path, sysfs_device->bus_id, sysfs_device->bus);
736                 strfieldcpy(udev->bus_id, sysfs_device->bus_id);
737         }
738
739         strfieldcpy(udev->kernel_name, class_dev->name);
740         fix_kernel_name(udev);
741         dbg("udev->kernel_name = '%s'", udev->kernel_name);
742
743         /* get kernel number */
744         pos = class_dev->name + strlen(class_dev->name);
745         while (isdigit(*(pos-1)))
746                 pos--;
747         strfieldcpy(udev->kernel_number, pos);
748         dbg("kernel_number='%s'", udev->kernel_number);
749
750         /* look for a matching rule to apply */
751         list_for_each_entry(dev, &config_device_list, node) {
752                 dbg("process rule");
753                 if (match_rule(udev, dev, class_dev, sysfs_device) == 0) {
754
755                         /* empty name, symlink and perms will not create any node */
756                         if (dev->name[0] == '\0' && dev->symlink[0] == '\0' &&
757                             dev->mode == 0000 && dev->owner[0] == '\0' && dev->group[0] == '\0') {
758                                 info("configured rule in '%s[%i]' applied, '%s' is ignored",
759                                      dev->config_file, dev->config_line, udev->kernel_name);
760                                 return -1;
761                         }
762
763                         /* apply permissions */
764                         if (dev->mode != 0000) {
765                                 udev->mode = dev->mode;
766                                 dbg("applied mode=%#o to '%s'", udev->mode, udev->kernel_name);
767                         }
768                         if (dev->owner[0] != '\0') {
769                                 strfieldcpy(udev->owner, dev->owner);
770                                 apply_format(udev, udev->owner, sizeof(udev->owner), class_dev, sysfs_device);
771                                 dbg("applied owner='%s' to '%s'", udev->owner, udev->kernel_name);
772                         }
773                         if (dev->group[0] != '\0') {
774                                 strfieldcpy(udev->group, dev->group);
775                                 apply_format(udev, udev->group, sizeof(udev->group), class_dev, sysfs_device);
776                                 dbg("applied group='%s' to '%s'", udev->group, udev->kernel_name);
777                         }
778
779                         /* collect symlinks for this or the final matching rule */
780                         if (dev->symlink[0] != '\0') {
781                                 char temp[NAME_SIZE];
782
783                                 info("configured rule in '%s[%i]' applied, added symlink '%s'",
784                                      dev->config_file, dev->config_line, dev->symlink);
785                                 strfieldcpy(temp, dev->symlink);
786                                 apply_format(udev, temp, sizeof(temp), class_dev, sysfs_device);
787                                 if (udev->symlink[0] != '\0')
788                                         strfieldcat(udev->symlink, " ");
789                                 strfieldcat(udev->symlink, temp);
790                         }
791
792                         /* rule matches */
793                         if (dev->name[0] != '\0') {
794                                 /* apply all_partitions flag only at a main block device */
795                                 if (dev->partitions > 0 &&
796                                     (udev->type != 'b' || udev->kernel_number[0] != '\0'))
797                                         continue;
798
799                                 info("configured rule in '%s[%i]' applied, '%s' becomes '%s'",
800                                      dev->config_file, dev->config_line, udev->kernel_name, dev->name);
801
802                                 strfieldcpy(udev->name, dev->name);
803                                 apply_format(udev, udev->name, sizeof(udev->name), class_dev, sysfs_device);
804                                 strfieldcpy(udev->config_file, dev->config_file);
805                                 udev->config_line = dev->config_line;
806                                 udev->ignore_remove = dev->ignore_remove;
807
808                                 if (udev->type == 'n')
809                                         goto exit;
810
811                                 udev->partitions = dev->partitions;
812
813                                 dbg("name, '%s' is going to have owner='%s', group='%s', mode=%#o partitions=%i",
814                                     udev->name, udev->owner, udev->group, udev->mode, udev->partitions);
815
816                                 goto exit;
817                         }
818                 }
819         }
820
821         /* no rule matched, so we use the kernel name */
822         strfieldcpy(udev->name, udev->kernel_name);
823         dbg("no rule found, use kernel name '%s'", udev->name);
824
825 exit:
826         if (udev->tmp_node[0] != '\0') {
827                 dbg("removing temporary device node");
828                 unlink_secure(udev->tmp_node);
829                 udev->tmp_node[0] = '\0';
830         }
831
832         return 0;
833 }