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/stat.h>
  32
  33 #include "libsysfs/sysfs/libsysfs.h"
  34 #include "udev_libc_wrapper.h"
  35 #include "udev.h"
  36 #include "logging.h"
  37 #include "udev_rules.h"
  38 #include "udev_utils.h"
  39 #include "list.h"
  40
  41
  42 dev_t get_devt(struct sysfs_class_device *class_dev)
  43 {
  44         struct sysfs_attribute *attr = NULL;
  45         unsigned int major, minor;
  46         char *maj, *min;
  47
  48         maj = getenv("MAJOR");
  49         min = getenv("MINOR");
  50
  51         if (maj && min) {
  52                 major = atoi(maj);
  53                 minor = atoi(min);
  54         } else {
  55                 attr = sysfs_get_classdev_attr(class_dev, "dev");
  56                 if (attr == NULL)
  57                         return 0;
  58                 dbg("dev='%s'", attr->value);
  59
  60                 if (sscanf(attr->value, "%u:%u", &major, &minor) != 2)
  61                         return 0;
  62         }
  63
  64         dbg("found major=%d, minor=%d", major, minor);
  65         return makedev(major, minor);
  66 }
  67
  68 int udev_process_event(struct udev_rules *rules, struct udevice *udev)
  69 {
  70         int retval;
  71         char path[PATH_SIZE];
  72
  73         if (udev->type == DEV_BLOCK || udev->type == DEV_CLASS || udev->type == DEV_NET) {
  74                 /* handle device node */
  75                 if (strcmp(udev->action, "add") == 0) {
  76                         struct sysfs_class_device *class_dev;
  77
  78                         dbg("node add");
  79                         snprintf(path, sizeof(path), "%s%s", sysfs_path, udev->devpath);
  80                         path[sizeof(path)-1] = '\0';
  81                         class_dev = sysfs_open_class_device_path(path);
  82                         if (class_dev == NULL) {
  83                                 dbg("open class device failed");
  84                                 return 0;
  85                         }
  86                         dbg("opened class_dev->name='%s'", class_dev->name);
  87
  88                         /* get major/minor */
  89                         if (udev->type == DEV_BLOCK || udev->type == DEV_CLASS)
  90                                 udev->devt = get_devt(class_dev);
  91
  92                         if (udev->type == DEV_NET || udev->devt) {
  93                                 /* name device */
  94                                 udev_rules_get_name(rules, udev, class_dev);
  95                                 if (udev->ignore_device) {
  96                                         info("device event will be ignored");
  97                                         sysfs_close_class_device(class_dev);
  98                                         return 0;
  99                                 }
 100                                 if (udev->name[0] != '\0') {
 101                                         /* create node, store in db */
 102                                         retval = udev_add_device(udev, class_dev);
 103                                 } else {
 104                                         info("device node creation supressed");
 105                                 }
 106                         } else {
 107                                 dbg("no dev-file found");
 108                                 udev_rules_get_run(rules, udev, class_dev, NULL);
 109                                 if (udev->ignore_device) {
 110                                         info("device event will be ignored");
 111                                         sysfs_close_class_device(class_dev);
 112                                         return 0;
 113                                 }
 114                         }
 115                         sysfs_close_class_device(class_dev);
 116                 } else if (strcmp(udev->action, "remove") == 0) {
 117                         struct name_entry *name_loop;
 118
 119                         /* get data from db, remove db-entry, delete node */
 120                         dbg("node remove");
 121                         retval = udev_remove_device(udev);
 122
 123                         /* restore stored persistent data */
 124                         list_for_each_entry(name_loop, &udev->env_list, node)
 125                                 putenv(name_loop->name);
 126
 127                         udev_rules_get_run(rules, udev, NULL, NULL);
 128                         if (udev->ignore_device) {
 129                                 dbg("device event will be ignored");
 130                                 return 0;
 131                         }
 132                 }
 133
 134                 /* export name of device node or netif */
 135                 if (udev->devname[0] != '\0')
 136                         setenv("DEVNAME", udev->devname, 1);
 137         } else if (udev->type == DEV_DEVICE && strcmp(udev->action, "add") == 0) {
 138                 struct sysfs_device *devices_dev;
 139
 140                 dbg("devices add");
 141                 snprintf(path, sizeof(path), "%s%s", sysfs_path, udev->devpath);
 142                 path[sizeof(path)-1] = '\0';
 143                 devices_dev = sysfs_open_device_path(path);
 144                 if (!devices_dev) {
 145                         dbg("devices device unavailable (probably remove has beaten us)");
 146                         return 0;
 147                 }
 148
 149                 dbg("devices device opened '%s'", path);
 150                 udev_rules_get_run(rules, udev, NULL, devices_dev);
 151                 sysfs_close_device(devices_dev);
 152                 if (udev->ignore_device) {
 153                         info("device event will be ignored");
 154                         return 0;
 155                 }
 156         } else {
 157                 dbg("default handling");
 158                 udev_rules_get_run(rules, udev, NULL, NULL);
 159                 if (udev->ignore_device) {
 160                         info("device event will be ignored");
 161                         return 0;
 162                 }
 163         }
 164         return 0;
 165 }