udev_device.c

   1 /*
   2  * udev_device.c - main udev data object
   3  *
   4  * Copyright (C) 2004-2006 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 <stropts.h>
  30 #include <net/if.h>
  31 #include <linux/sockios.h>
  32
  33 #include "udev.h"
  34 #include "udev_rules.h"
  35
  36
  37 struct udevice *udev_device_init(void)
  38 {
  39         struct udevice *udev;
  40
  41         udev = malloc(sizeof(struct udevice));
  42         if (udev == NULL)
  43                 return NULL;
  44         memset(udev, 0x00, sizeof(struct udevice));
  45
  46         INIT_LIST_HEAD(&udev->symlink_list);
  47         INIT_LIST_HEAD(&udev->run_list);
  48         INIT_LIST_HEAD(&udev->env_list);
  49
  50         /* set sysfs device to local storage, can be overridden if needed */
  51         udev->dev = &udev->dev_local;
  52
  53         /* default node permissions */
  54         udev->mode = 0660;
  55         strcpy(udev->owner, "root");
  56         strcpy(udev->group, "root");
  57
  58         return udev;
  59 }
  60
  61 void udev_device_cleanup(struct udevice *udev)
  62 {
  63         name_list_cleanup(&udev->symlink_list);
  64         name_list_cleanup(&udev->run_list);
  65         name_list_cleanup(&udev->env_list);
  66         free(udev);
  67 }
  68
  69 dev_t udev_device_get_devt(struct udevice *udev)
  70 {
  71         const char *attr;
  72         unsigned int major, minor;
  73
  74         /* read it from sysfs  */
  75         attr = sysfs_attr_get_value(udev->dev->devpath, "dev");
  76         if (attr != NULL) {
  77                 if (sscanf(attr, "%u:%u", &major, &minor) == 2)
  78                         return makedev(major, minor);
  79         }
  80         return makedev(0, 0);
  81 }
  82
  83 static int rename_net_if(struct udevice *udev)
  84 {
  85         int sk;
  86         struct ifreq ifr;
  87         int retval;
  88
  89         info("changing net interface name from '%s' to '%s'", udev->dev->kernel_name, udev->name);
  90         if (udev->test_run)
  91                 return 0;
  92
  93         sk = socket(PF_INET, SOCK_DGRAM, 0);
  94         if (sk < 0) {
  95                 err("error opening socket: %s", strerror(errno));
  96                 return -1;
  97         }
  98
  99         memset(&ifr, 0x00, sizeof(struct ifreq));
 100         strlcpy(ifr.ifr_name, udev->dev->kernel_name, IFNAMSIZ);
 101         strlcpy(ifr.ifr_newname, udev->name, IFNAMSIZ);
 102
 103         retval = ioctl(sk, SIOCSIFNAME, &ifr);
 104         if (retval != 0)
 105                 err("error changing net interface name: %s", strerror(errno));
 106         close(sk);
 107
 108         return retval;
 109 }
 110
 111 int udev_device_event(struct udev_rules *rules, struct udevice *udev)
 112 {
 113         int retval = 0;
 114
 115         /* add device node */
 116         if (major(udev->devt) != 0 && strcmp(udev->action, "add") == 0) {
 117                 struct udevice *udev_old;
 118
 119                 dbg("device node add '%s'", udev->dev->devpath);
 120
 121                 udev_rules_get_name(rules, udev);
 122                 if (udev->ignore_device) {
 123                         info("device event will be ignored");
 124                         goto exit;
 125                 }
 126                 if (udev->name[0] == '\0') {
 127                         info("device node creation supressed");
 128                         goto exit;
 129                 }
 130
 131                 /* read current database entry, we may want to cleanup symlinks */
 132                 udev_old = udev_device_init();
 133                 if (udev_old != NULL) {
 134                         if (udev_db_get_device(udev_old, udev->dev->devpath) == 0) {
 135                                 info("device '%s' already known, remove possible symlinks", udev->dev->devpath);
 136                                 udev_node_remove_symlinks(udev_old);
 137                         }
 138                         udev_device_cleanup(udev_old);
 139                 }
 140
 141                 /* create node and symlinks, store record in database */
 142                 retval = udev_node_add(udev, udev_old);
 143                 if (retval == 0)
 144                         udev_db_add_device(udev);
 145                 goto exit;
 146         }
 147
 148         /* add netif */
 149         if (strcmp(udev->dev->subsystem, "net") == 0 && strcmp(udev->action, "add") == 0) {
 150                 dbg("netif add '%s'", udev->dev->devpath);
 151                 udev_rules_get_name(rules, udev);
 152                 if (udev->ignore_device) {
 153                         info("device event will be ignored");
 154                         goto exit;
 155                 }
 156
 157                 /* look if we want to change the name of the netif */
 158                 if (strcmp(udev->name, udev->dev->kernel_name) != 0) {
 159                         char *pos;
 160
 161                         retval = rename_net_if(udev);
 162                         if (retval != 0)
 163                                 goto exit;
 164                         info("renamed netif to '%s'", udev->name);
 165
 166                         /* export old name */
 167                         setenv("INTERFACE_OLD", udev->dev->kernel_name, 1);
 168
 169                         /* now fake the devpath, because the kernel name changed silently */
 170                         pos = strrchr(udev->dev->devpath, '/');
 171                         if (pos != NULL) {
 172                                 pos[1] = '\0';
 173                                 strlcat(udev->dev->devpath, udev->name, sizeof(udev->dev->devpath));
 174                                 strlcpy(udev->dev->kernel_name, udev->name, sizeof(udev->dev->kernel_name));
 175                                 setenv("DEVPATH", udev->dev->devpath, 1);
 176                                 setenv("INTERFACE", udev->name, 1);
 177                         }
 178                 }
 179                 goto exit;
 180         }
 181
 182         /* remove device node */
 183         if (major(udev->devt) != 0 && strcmp(udev->action, "remove") == 0) {
 184                 struct name_entry *name_loop;
 185
 186                 /* import and delete database entry */
 187                 if (udev_db_get_device(udev, udev->dev->devpath) == 0) {
 188                         udev_db_delete_device(udev);
 189                         if (udev->ignore_remove) {
 190                                 dbg("remove event for '%s' requested to be ignored by rule", udev->name);
 191                                 return 0;
 192                         }
 193                         /* restore stored persistent data */
 194                         list_for_each_entry(name_loop, &udev->env_list, node)
 195                                 putenv(name_loop->name);
 196                 } else {
 197                         dbg("'%s' not found in database, using kernel name '%s'", udev->dev->devpath, udev->dev->kernel_name);
 198                         strlcpy(udev->name, udev->dev->kernel_name, sizeof(udev->name));
 199                 }
 200
 201                 udev_rules_get_run(rules, udev);
 202                 if (udev->ignore_device) {
 203                         info("device event will be ignored");
 204                         goto exit;
 205                 }
 206
 207                 retval = udev_node_remove(udev);
 208                 goto exit;
 209         }
 210
 211         /* default devices */
 212         udev_rules_get_run(rules, udev);
 213         if (udev->ignore_device)
 214                 info("device event will be ignored");
 215
 216 exit:
 217         return retval;
 218 }