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 <sys/ioctl.h>
  30 #include <sys/socket.h>
  31 #include <net/if.h>
  32 #include <linux/sockios.h>
  33
  34 #include "udev.h"
  35 #include "udev_rules.h"
  36
  37
  38 struct udevice *udev_device_init(void)
  39 {
  40         struct udevice *udev;
  41
  42         udev = malloc(sizeof(struct udevice));
  43         if (udev == NULL)
  44                 return NULL;
  45         memset(udev, 0x00, sizeof(struct udevice));
  46
  47         INIT_LIST_HEAD(&udev->symlink_list);
  48         INIT_LIST_HEAD(&udev->run_list);
  49         INIT_LIST_HEAD(&udev->env_list);
  50
  51         /* set sysfs device to local storage, can be overridden if needed */
  52         udev->dev = &udev->dev_local;
  53
  54         /* default node permissions */
  55         udev->mode = 0660;
  56         strcpy(udev->owner, "root");
  57         strcpy(udev->group, "root");
  58
  59         return udev;
  60 }
  61
  62 void udev_device_cleanup(struct udevice *udev)
  63 {
  64         name_list_cleanup(&udev->symlink_list);
  65         name_list_cleanup(&udev->run_list);
  66         name_list_cleanup(&udev->env_list);
  67         free(udev);
  68 }
  69
  70 dev_t udev_device_get_devt(struct udevice *udev)
  71 {
  72         const char *attr;
  73         unsigned int major, minor;
  74
  75         /* read it from sysfs  */
  76         attr = sysfs_attr_get_value(udev->dev->devpath, "dev");
  77         if (attr != NULL) {
  78                 if (sscanf(attr, "%u:%u", &major, &minor) == 2)
  79                         return makedev(major, minor);
  80         }
  81         return makedev(0, 0);
  82 }
  83
  84 static int rename_net_if(struct udevice *udev)
  85 {
  86         int sk;
  87         struct ifreq ifr;
  88         int retval;
  89
  90         info("changing net interface name from '%s' to '%s'", udev->dev->kernel_name, udev->name);
  91         if (udev->test_run)
  92                 return 0;
  93
  94         sk = socket(PF_INET, SOCK_DGRAM, 0);
  95         if (sk < 0) {
  96                 err("error opening socket: %s", strerror(errno));
  97                 return -1;
  98         }
  99
 100         memset(&ifr, 0x00, sizeof(struct ifreq));
 101         strlcpy(ifr.ifr_name, udev->dev->kernel_name, IFNAMSIZ);
 102         strlcpy(ifr.ifr_newname, udev->name, IFNAMSIZ);
 103
 104         retval = ioctl(sk, SIOCSIFNAME, &ifr);
 105         if (retval != 0)
 106                 err("error changing net interface name: %s", strerror(errno));
 107         close(sk);
 108
 109         return retval;
 110 }
 111
 112 int udev_device_event(struct udev_rules *rules, struct udevice *udev)
 113 {
 114         int retval = 0;
 115
 116         /* add device node */
 117         if (major(udev->devt) != 0 && strcmp(udev->action, "add") == 0) {
 118                 struct udevice *udev_old;
 119
 120                 dbg("device node add '%s'", udev->dev->devpath);
 121
 122                 udev_rules_get_name(rules, udev);
 123                 if (udev->ignore_device) {
 124                         info("device event will be ignored");
 125                         goto exit;
 126                 }
 127                 if (udev->name[0] == '\0') {
 128                         info("device node creation supressed");
 129                         goto exit;
 130                 }
 131
 132                 /* read current database entry, we may want to cleanup symlinks */
 133                 udev_old = udev_device_init();
 134                 if (udev_old != NULL) {
 135                         if (udev_db_get_device(udev_old, udev->dev->devpath) != 0) {
 136                                 udev_device_cleanup(udev_old);
 137                                 udev_old = NULL;
 138                         } else
 139                                 info("device '%s' already in database, validate currently present symlinks",
 140                                      udev->dev->devpath);
 141                 }
 142
 143                 /* create node and symlinks */
 144                 retval = udev_node_add(udev, udev_old);
 145                 if (retval == 0) {
 146                         /* store record in database */
 147                         udev_db_add_device(udev);
 148
 149                         /* remove possibly left-over symlinks */
 150                         if (udev_old != NULL) {
 151                                 struct name_entry *link_loop;
 152                                 struct name_entry *link_old_loop;
 153                                 struct name_entry *link_old_tmp_loop;
 154
 155                                 /* remove still valid symlinks from old list */
 156                                 list_for_each_entry_safe(link_old_loop, link_old_tmp_loop, &udev_old->symlink_list, node)
 157                                         list_for_each_entry(link_loop, &udev->symlink_list, node)
 158                                                 if (strcmp(link_old_loop->name, link_loop->name) == 0) {
 159                                                         dbg("symlink '%s' still valid, keep it", link_old_loop->name);
 160                                                         list_del(&link_old_loop->node);
 161                                                         free(link_old_loop);
 162                                                 }
 163                                 udev_node_remove_symlinks(udev_old);
 164                                 udev_device_cleanup(udev_old);
 165                         }
 166                 }
 167                 goto exit;
 168         }
 169
 170         /* add netif */
 171         if (strcmp(udev->dev->subsystem, "net") == 0 && strcmp(udev->action, "add") == 0) {
 172                 dbg("netif add '%s'", udev->dev->devpath);
 173                 udev_rules_get_name(rules, udev);
 174                 if (udev->ignore_device) {
 175                         info("device event will be ignored");
 176                         goto exit;
 177                 }
 178
 179                 /* look if we want to change the name of the netif */
 180                 if (strcmp(udev->name, udev->dev->kernel_name) != 0) {
 181                         char *pos;
 182
 183                         retval = rename_net_if(udev);
 184                         if (retval != 0)
 185                                 goto exit;
 186                         info("renamed netif to '%s'", udev->name);
 187
 188                         /* export old name */
 189                         setenv("INTERFACE_OLD", udev->dev->kernel_name, 1);
 190
 191                         /* now fake the devpath, because the kernel name changed silently */
 192                         pos = strrchr(udev->dev->devpath, '/');
 193                         if (pos != NULL) {
 194                                 pos[1] = '\0';
 195                                 strlcat(udev->dev->devpath, udev->name, sizeof(udev->dev->devpath));
 196                                 strlcpy(udev->dev->kernel_name, udev->name, sizeof(udev->dev->kernel_name));
 197                                 setenv("DEVPATH", udev->dev->devpath, 1);
 198                                 setenv("INTERFACE", udev->name, 1);
 199                         }
 200                 }
 201                 goto exit;
 202         }
 203
 204         /* remove device node */
 205         if (major(udev->devt) != 0 && strcmp(udev->action, "remove") == 0) {
 206                 struct name_entry *name_loop;
 207
 208                 /* import and delete database entry */
 209                 if (udev_db_get_device(udev, udev->dev->devpath) == 0) {
 210                         udev_db_delete_device(udev);
 211                         if (udev->ignore_remove) {
 212                                 dbg("remove event for '%s' requested to be ignored by rule", udev->name);
 213                                 return 0;
 214                         }
 215                         /* restore stored persistent data */
 216                         list_for_each_entry(name_loop, &udev->env_list, node)
 217                                 putenv(name_loop->name);
 218                 } else {
 219                         dbg("'%s' not found in database, using kernel name '%s'", udev->dev->devpath, udev->dev->kernel_name);
 220                         strlcpy(udev->name, udev->dev->kernel_name, sizeof(udev->name));
 221                 }
 222
 223                 udev_rules_get_run(rules, udev);
 224                 if (udev->ignore_device) {
 225                         info("device event will be ignored");
 226                         goto exit;
 227                 }
 228
 229                 retval = udev_node_remove(udev);
 230                 goto exit;
 231         }
 232
 233         /* default devices */
 234         udev_rules_get_run(rules, udev);
 235         if (udev->ignore_device)
 236                 info("device event will be ignored");
 237
 238 exit:
 239         return retval;
 240 }