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_netif(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, 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, IFNAMSIZ);
 102         strlcpy(ifr.ifr_newname, udev->name, IFNAMSIZ);
 103         retval = ioctl(sk, SIOCSIFNAME, &ifr);
 104         if (retval != 0) {
 105                 int loop;
 106
 107                 /* see if the destination interface name already exists */
 108                 if (errno != EEXIST) {
 109                         err("error changing netif name %s to %s: %s", ifr.ifr_name, ifr.ifr_newname, strerror(errno));
 110                         goto exit;
 111                 }
 112
 113                 /* free our own name, another process may wait for us */
 114                 strlcpy(ifr.ifr_newname, udev->dev->kernel, IFNAMSIZ);
 115                 strlcat(ifr.ifr_newname, "_rename", IFNAMSIZ);
 116                 retval = ioctl(sk, SIOCSIFNAME, &ifr);
 117                 if (retval != 0) {
 118                         err("error changing netif name %s to %s: %s", ifr.ifr_name, ifr.ifr_newname, strerror(errno));
 119                         goto exit;
 120                 }
 121
 122                 /* wait 30 seconds for our target to become available */
 123                 strlcpy(ifr.ifr_name, ifr.ifr_newname, IFNAMSIZ);
 124                 strlcpy(ifr.ifr_newname, udev->name, IFNAMSIZ);
 125                 loop = 30 * 20;
 126                 while (loop--) {
 127                         retval = ioctl(sk, SIOCSIFNAME, &ifr);
 128                         if (retval != 0) {
 129                                 if (errno != EEXIST) {
 130                                         err("error changing net interface name %s to %s: %s",
 131                                             ifr.ifr_name, ifr.ifr_newname, strerror(errno));
 132                                         break;
 133                                 }
 134                                 dbg("wait for netif '%s' to become free, loop=%i", udev->name, (30 * 20) - loop);
 135                                 usleep(1000 * 1000 / 20);
 136                         }
 137                 }
 138         }
 139
 140 exit:
 141         close(sk);
 142         return retval;
 143 }
 144
 145 int udev_device_event(struct udev_rules *rules, struct udevice *udev)
 146 {
 147         int retval = 0;
 148
 149         /* add device node */
 150         if (major(udev->devt) != 0 &&
 151             (strcmp(udev->action, "add") == 0 || strcmp(udev->action, "change") == 0)) {
 152                 struct udevice *udev_old;
 153
 154                 dbg("device node add '%s'", udev->dev->devpath);
 155
 156                 udev_rules_get_name(rules, udev);
 157                 if (udev->ignore_device) {
 158                         info("device event will be ignored");
 159                         goto exit;
 160                 }
 161                 if (udev->name[0] == '\0') {
 162                         info("device node creation supressed");
 163                         goto exit;
 164                 }
 165
 166                 /* read current database entry, we may want to cleanup symlinks */
 167                 udev_old = udev_device_init();
 168                 if (udev_old != NULL) {
 169                         if (udev_db_get_device(udev_old, udev->dev->devpath) != 0) {
 170                                 udev_device_cleanup(udev_old);
 171                                 udev_old = NULL;
 172                         } else
 173                                 info("device '%s' already in database, validate currently present symlinks",
 174                                      udev->dev->devpath);
 175                 }
 176
 177                 /* create node and symlinks */
 178                 retval = udev_node_add(udev, udev_old);
 179                 if (retval == 0) {
 180                         /* store record in database */
 181                         udev_db_add_device(udev);
 182
 183                         /* remove possibly left-over symlinks */
 184                         if (udev_old != NULL) {
 185                                 struct name_entry *link_loop;
 186                                 struct name_entry *link_old_loop;
 187                                 struct name_entry *link_old_tmp_loop;
 188
 189                                 /* remove still valid symlinks from old list */
 190                                 list_for_each_entry_safe(link_old_loop, link_old_tmp_loop, &udev_old->symlink_list, node)
 191                                         list_for_each_entry(link_loop, &udev->symlink_list, node)
 192                                                 if (strcmp(link_old_loop->name, link_loop->name) == 0) {
 193                                                         dbg("symlink '%s' still valid, keep it", link_old_loop->name);
 194                                                         list_del(&link_old_loop->node);
 195                                                         free(link_old_loop);
 196                                                 }
 197                                 udev_node_remove_symlinks(udev_old);
 198                                 udev_device_cleanup(udev_old);
 199                         }
 200                 }
 201                 goto exit;
 202         }
 203
 204         /* add netif */
 205         if (strcmp(udev->dev->subsystem, "net") == 0 && strcmp(udev->action, "add") == 0) {
 206                 dbg("netif add '%s'", udev->dev->devpath);
 207                 udev_rules_get_name(rules, udev);
 208                 if (udev->ignore_device) {
 209                         info("device event will be ignored");
 210                         goto exit;
 211                 }
 212
 213                 /* look if we want to change the name of the netif */
 214                 if (strcmp(udev->name, udev->dev->kernel) != 0) {
 215                         char *pos;
 216
 217                         retval = rename_netif(udev);
 218                         if (retval != 0)
 219                                 goto exit;
 220                         info("renamed netif to '%s'", udev->name);
 221
 222                         /* export old name */
 223                         setenv("INTERFACE_OLD", udev->dev->kernel, 1);
 224
 225                         /* now fake the devpath, because the kernel name changed silently */
 226                         pos = strrchr(udev->dev->devpath, '/');
 227                         if (pos != NULL) {
 228                                 pos[1] = '\0';
 229                                 strlcat(udev->dev->devpath, udev->name, sizeof(udev->dev->devpath));
 230                                 strlcpy(udev->dev->kernel, udev->name, sizeof(udev->dev->kernel));
 231                                 setenv("DEVPATH", udev->dev->devpath, 1);
 232                                 setenv("INTERFACE", udev->name, 1);
 233                         }
 234                 }
 235                 goto exit;
 236         }
 237
 238         /* remove device node */
 239         if (major(udev->devt) != 0 && strcmp(udev->action, "remove") == 0) {
 240                 struct name_entry *name_loop;
 241
 242                 /* import and delete database entry */
 243                 if (udev_db_get_device(udev, udev->dev->devpath) == 0) {
 244                         udev_db_delete_device(udev);
 245                         if (udev->ignore_remove) {
 246                                 dbg("remove event for '%s' requested to be ignored by rule", udev->name);
 247                                 return 0;
 248                         }
 249                         /* restore stored persistent data */
 250                         list_for_each_entry(name_loop, &udev->env_list, node)
 251                                 putenv(name_loop->name);
 252                 } else {
 253                         dbg("'%s' not found in database, using kernel name '%s'", udev->dev->devpath, udev->dev->kernel);
 254                         strlcpy(udev->name, udev->dev->kernel, sizeof(udev->name));
 255                 }
 256
 257                 udev_rules_get_run(rules, udev);
 258                 if (udev->ignore_device) {
 259                         info("device event will be ignored");
 260                         goto exit;
 261                 }
 262
 263                 retval = udev_node_remove(udev);
 264                 goto exit;
 265         }
 266
 267         /* default devices */
 268         udev_rules_get_run(rules, udev);
 269         if (udev->ignore_device)
 270                 info("device event will be ignored");
 271
 272 exit:
 273         return retval;
 274 }