udev_device.c

   1 /*
   2  * udev_utils.c - generic stuff used by udev
   3  *
   4  * Copyright (C) 2004, 2005 Kay Sievers <kay.sievers@vrfy.org>
   5  *
   6  *      This program is free software; you can redistribute it and/or modify it
   7  *      under the terms of the GNU General Public License as published by the
   8  *      Free Software Foundation version 2 of the License.
   9  *
  10  *      This program is distributed in the hope that it will be useful, but
  11  *      WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  *      General Public License for more details.
  14  *
  15  *      You should have received a copy of the GNU General Public License along
  16  *      with this program; if not, write to the Free Software Foundation, Inc.,
  17  *      675 Mass Ave, Cambridge, MA 02139, USA.
  18  *
  19  */
  20
  21
  22 #include <stdlib.h>
  23 #include <stdio.h>
  24 #include <stddef.h>
  25 #include <unistd.h>
  26 #include <fcntl.h>
  27 #include <errno.h>
  28 #include <ctype.h>
  29
  30 #include "udev.h"
  31 #include "udev_rules.h"
  32
  33
  34 struct udevice *udev_device_init(void)
  35 {
  36         struct udevice *udev;
  37
  38         udev = malloc(sizeof(struct udevice));
  39         if (udev == NULL)
  40                 return NULL;
  41         memset(udev, 0x00, sizeof(struct udevice));
  42
  43         INIT_LIST_HEAD(&udev->symlink_list);
  44         INIT_LIST_HEAD(&udev->run_list);
  45         INIT_LIST_HEAD(&udev->env_list);
  46
  47         /* set sysfs device to local storage, can be overridden if needed */
  48         udev->dev = &udev->dev_local;
  49
  50         /* default node permissions */
  51         udev->mode = 0660;
  52         strcpy(udev->owner, "root");
  53         strcpy(udev->group, "root");
  54
  55         return udev;
  56 }
  57
  58 void udev_device_cleanup(struct udevice *udev)
  59 {
  60         name_list_cleanup(&udev->symlink_list);
  61         name_list_cleanup(&udev->run_list);
  62         name_list_cleanup(&udev->env_list);
  63         free(udev);
  64 }
  65
  66 dev_t udev_device_get_devt(struct udevice *udev)
  67 {
  68         const char *attr;
  69         unsigned int major, minor;
  70
  71         /* read it from sysfs  */
  72         attr = sysfs_attr_get_value(udev->dev->devpath, "dev");
  73         if (attr != NULL) {
  74                 if (sscanf(attr, "%u:%u", &major, &minor) == 2)
  75                         return makedev(major, minor);
  76         }
  77         return makedev(0, 0);
  78 }
  79
  80 int udev_device_event(struct udev_rules *rules, struct udevice *udev)
  81 {
  82         int retval = 0;
  83
  84         /* device node or netif */
  85         if ((major(udev->devt) != 0 || strcmp(udev->dev->subsystem, "net") == 0) &&
  86             strcmp(udev->action, "add") == 0) {
  87                 dbg("device node or netif add '%s'", udev->dev->devpath);
  88                 udev_rules_get_name(rules, udev);
  89                 if (udev->ignore_device) {
  90                         info("device event will be ignored");
  91                         return 0;
  92                 }
  93                 /* create node, store in db */
  94                 if (udev->name[0] != '\0')
  95                         retval = udev_add_device(udev);
  96                 else
  97                         info("device node creation supressed");
  98                 return retval;
  99         }
 100
 101         if (major(udev->devt) != 0 && strcmp(udev->action, "remove") == 0) {
 102                 struct name_entry *name_loop;
 103
 104                 udev_rules_get_run(rules, udev);
 105                 if (udev->ignore_device) {
 106                         info("device event will be ignored");
 107                         return 0;
 108                 }
 109                 /* get data from db, remove db-entry, delete node */
 110                 retval = udev_remove_device(udev);
 111
 112                 /* restore stored persistent data */
 113                 list_for_each_entry(name_loop, &udev->env_list, node)
 114                         putenv(name_loop->name);
 115                 return retval;
 116         }
 117
 118         /* default devices without a node */
 119         udev_rules_get_run(rules, udev);
 120         if (udev->ignore_device)
 121                 info("device event will be ignored");
 122
 123         return retval;
 124 }