udev_event.c

   1 /*
   2  * udev_event.c - udev event process
   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 #include <dirent.h>
  30 #include <syslog.h>
  31
  32 #include "udev_libc_wrapper.h"
  33 #include "udev.h"
  34 #include "logging.h"
  35 #include "udev_rules.h"
  36 #include "udev_utils.h"
  37 #include "udev_sysfs.h"
  38 #include "list.h"
  39
  40
  41 int udev_process_event(struct udev_rules *rules, struct udevice *udev)
  42 {
  43         int retval;
  44         char path[PATH_SIZE];
  45         const char *error;
  46
  47         if (udev->type == DEV_BLOCK || udev->type == DEV_CLASS || udev->type == DEV_NET) {
  48                 /* handle device node */
  49                 if (strcmp(udev->action, "add") == 0) {
  50                         struct sysfs_class_device *class_dev;
  51
  52                         /* wait for sysfs of /sys/class /sys/block */
  53                         dbg("node add");
  54                         snprintf(path, sizeof(path), "%s%s", sysfs_path, udev->devpath);
  55                         path[sizeof(path)-1] = '\0';
  56                         class_dev = wait_class_device_open(path);
  57                         if (class_dev == NULL) {
  58                                 dbg("open class device failed");
  59                                 return 0;
  60                         }
  61                         dbg("opened class_dev->name='%s'", class_dev->name);
  62                         wait_for_class_device(class_dev, &error);
  63
  64                         /* get major/minor */
  65                         if (udev->type == DEV_BLOCK || udev->type == DEV_CLASS)
  66                                 udev->devt = get_devt(class_dev);
  67
  68                         if (udev->type == DEV_NET || udev->devt) {
  69                                 /* name device */
  70                                 udev_rules_get_name(rules, udev, class_dev);
  71                                 if (udev->ignore_device) {
  72                                         info("device event will be ignored");
  73                                         sysfs_close_class_device(class_dev);
  74                                         return -1;
  75                                 }
  76                                 if (udev->name[0] == '\0') {
  77                                         info("device node creation supressed");
  78                                         sysfs_close_class_device(class_dev);
  79                                         return -1;
  80                                 }
  81                                 /* create node, store in db */
  82                                 retval = udev_add_device(udev, class_dev);
  83                         } else {
  84                                 dbg("no dev-file found");
  85                                 udev_rules_get_run(rules, udev, class_dev, NULL);
  86                                 if (udev->ignore_device) {
  87                                         info("device event will be ignored");
  88                                         sysfs_close_class_device(class_dev);
  89                                         return -1;
  90                                 }
  91                         }
  92                         sysfs_close_class_device(class_dev);
  93                 } else if (strcmp(udev->action, "remove") == 0) {
  94                         dbg("node remove");
  95                         udev_rules_get_run(rules, udev, NULL, NULL);
  96                         if (udev->ignore_device) {
  97                                 dbg("device event will be ignored");
  98                                 return -1;
  99                         }
 100
 101                         /* get name from db, remove db-entry, delete node */
 102                         retval = udev_remove_device(udev);
 103                 }
 104
 105                 /* export name of device node or netif */
 106                 if (udev->devname[0] != '\0')
 107                         setenv("DEVNAME", udev->devname, 1);
 108         } else if (udev->type == DEV_DEVICE && strcmp(udev->action, "add") == 0) {
 109                 struct sysfs_device *devices_dev;
 110
 111                 /* wait for sysfs of /sys/devices/ */
 112                 dbg("devices add");
 113                 snprintf(path, sizeof(path), "%s%s", sysfs_path, udev->devpath);
 114                 path[sizeof(path)-1] = '\0';
 115                 devices_dev = wait_devices_device_open(path);
 116                 if (!devices_dev) {
 117                         dbg("devices device unavailable (probably remove has beaten us)");
 118                         return 0;
 119                 }
 120                 dbg("devices device opened '%s'", path);
 121                 wait_for_devices_device(devices_dev, &error);
 122                 udev_rules_get_run(rules, udev, NULL, devices_dev);
 123                 sysfs_close_device(devices_dev);
 124                 if (udev->ignore_device) {
 125                         info("device event will be ignored");
 126                         return -1;
 127                 }
 128         } else {
 129                 dbg("default handling");
 130                 udev_rules_get_run(rules, udev, NULL, NULL);
 131                 if (udev->ignore_device) {
 132                         info("device event will be ignored");
 133                         return -1;
 134                 }
 135         }
 136         return 0;
 137 }