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 #include <sys/wait.h>
  32 #include <sys/stat.h>
  33 #include <sys/mman.h>
  34 #include <sys/utsname.h>
  35
  36 #include "udev_libc_wrapper.h"
  37 #include "udev.h"
  38 #include "logging.h"
  39 #include "udev_rules.h"
  40 #include "udev_utils.h"
  41 #include "udev_sysfs.h"
  42 #include "list.h"
  43
  44
  45 int udev_process_event(struct udev_rules *rules, struct udevice *udev)
  46 {
  47         int retval;
  48         char path[PATH_SIZE];
  49         const char *error;
  50
  51         if (udev->type == DEV_BLOCK || udev->type == DEV_CLASS || udev->type == DEV_NET) {
  52                 /* handle device node */
  53                 if (strcmp(udev->action, "add") == 0) {
  54                         struct sysfs_class_device *class_dev;
  55
  56                         /* wait for sysfs of /sys/class /sys/block */
  57                         dbg("node add");
  58                         snprintf(path, sizeof(path), "%s%s", sysfs_path, udev->devpath);
  59                         path[sizeof(path)-1] = '\0';
  60                         class_dev = wait_class_device_open(path);
  61                         if (class_dev == NULL) {
  62                                 dbg("open class device failed");
  63                                 return 0;
  64                         }
  65                         dbg("opened class_dev->name='%s'", class_dev->name);
  66                         wait_for_class_device(class_dev, &error);
  67
  68                         /* get major/minor */
  69                         if (udev->type == DEV_BLOCK || udev->type == DEV_CLASS)
  70                                 udev->devt = get_devt(class_dev);
  71
  72                         if (udev->type == DEV_NET || udev->devt) {
  73                                 /* name device */
  74                                 udev_rules_get_name(rules, udev, class_dev);
  75                                 if (udev->ignore_device) {
  76                                         info("device event will be ignored");
  77                                         sysfs_close_class_device(class_dev);
  78                                         return -1;
  79                                 }
  80                                 if (udev->name[0] == '\0') {
  81                                         info("device node creation supressed");
  82                                         sysfs_close_class_device(class_dev);
  83                                         return -1;
  84                                 }
  85                                 /* create node, store in db */
  86                                 retval = udev_add_device(udev, class_dev);
  87                         } else {
  88                                 dbg("no dev-file found");
  89                                 udev_rules_get_run(rules, udev, class_dev, NULL);
  90                                 if (udev->ignore_device) {
  91                                         info("device event will be ignored");
  92                                         sysfs_close_class_device(class_dev);
  93                                         return -1;
  94                                 }
  95                         }
  96                         sysfs_close_class_device(class_dev);
  97                 } else if (strcmp(udev->action, "remove") == 0) {
  98                         dbg("node remove");
  99                         udev_rules_get_run(rules, udev, NULL, NULL);
 100                         if (udev->ignore_device) {
 101                                 dbg("device event will be ignored");
 102                                 return -1;
 103                         }
 104
 105                         /* get name from db, remove db-entry, delete node */
 106                         retval = udev_remove_device(udev);
 107                 }
 108
 109                 /* export name of device node or netif */
 110                 if (udev->devname[0] != '\0')
 111                         setenv("DEVNAME", udev->devname, 1);
 112         } else if (udev->type == DEV_DEVICE && strcmp(udev->action, "add") == 0) {
 113                 struct sysfs_device *devices_dev;
 114
 115                 /* wait for sysfs of /sys/devices/ */
 116                 dbg("devices add");
 117                 snprintf(path, sizeof(path), "%s%s", sysfs_path, udev->devpath);
 118                 path[sizeof(path)-1] = '\0';
 119                 devices_dev = wait_devices_device_open(path);
 120                 if (!devices_dev) {
 121                         dbg("devices device unavailable (probably remove has beaten us)");
 122                         return 0;
 123                 }
 124                 dbg("devices device opened '%s'", path);
 125                 wait_for_devices_device(devices_dev, &error);
 126                 udev_rules_get_run(rules, udev, NULL, devices_dev);
 127                 sysfs_close_device(devices_dev);
 128                 if (udev->ignore_device) {
 129                         info("device event will be ignored");
 130                         return -1;
 131                 }
 132         } else {
 133                 dbg("default handling");
 134                 udev_rules_get_run(rules, udev, NULL, NULL);
 135                 if (udev->ignore_device) {
 136                         info("device event will be ignored");
 137                         return -1;
 138                 }
 139         }
 140         return 0;
 141 }