udev/udev_device_event.c

   1 /*
   2  * Copyright (C) 2004-2008 Kay Sievers <kay.sievers@vrfy.org>
   3  *
   4  * This program is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include <stdlib.h>
  19 #include <stdio.h>
  20 #include <stddef.h>
  21 #include <unistd.h>
  22 #include <fcntl.h>
  23 #include <errno.h>
  24 #include <ctype.h>
  25 #include <string.h>
  26 #include <sys/ioctl.h>
  27 #include <sys/socket.h>
  28 #include <net/if.h>
  29 #include <linux/sockios.h>
  30
  31 #include "udev.h"
  32 #include "udev_rules.h"
  33
  34 static void kernel_log(struct ifreq ifr)
  35 {
  36         int klog;
  37         FILE *f;
  38
  39         klog = open("/dev/kmsg", O_WRONLY);
  40         if (klog < 0)
  41                 return;
  42
  43         f = fdopen(klog, "w");
  44         if (f == NULL) {
  45                 close(klog);
  46                 return;
  47         }
  48
  49         fprintf(f, "<6>udev: renamed network interface %s to %s\n",
  50                 ifr.ifr_name, ifr.ifr_newname);
  51         fclose(f);
  52 }
  53
  54 static int rename_netif(struct udevice *udevice)
  55 {
  56         int sk;
  57         struct ifreq ifr;
  58         int retval;
  59
  60         info(udevice->udev, "changing net interface name from '%s' to '%s'\n", udevice->dev->kernel, udevice->name);
  61         if (udevice->test_run)
  62                 return 0;
  63
  64         sk = socket(PF_INET, SOCK_DGRAM, 0);
  65         if (sk < 0) {
  66                 err(udevice->udev, "error opening socket: %m\n");
  67                 return -1;
  68         }
  69
  70         memset(&ifr, 0x00, sizeof(struct ifreq));
  71         util_strlcpy(ifr.ifr_name, udevice->dev->kernel, IFNAMSIZ);
  72         util_strlcpy(ifr.ifr_newname, udevice->name, IFNAMSIZ);
  73         retval = ioctl(sk, SIOCSIFNAME, &ifr);
  74         if (retval == 0)
  75                 kernel_log(ifr);
  76         else {
  77                 int loop;
  78
  79                 /* see if the destination interface name already exists */
  80                 if (errno != EEXIST) {
  81                         err(udevice->udev, "error changing netif name %s to %s: %m\n",
  82                             ifr.ifr_name, ifr.ifr_newname);
  83                         goto exit;
  84                 }
  85
  86                 /* free our own name, another process may wait for us */
  87                 util_strlcpy(ifr.ifr_newname, udevice->dev->kernel, IFNAMSIZ);
  88                 util_strlcat(ifr.ifr_newname, "_rename", IFNAMSIZ);
  89                 retval = ioctl(sk, SIOCSIFNAME, &ifr);
  90                 if (retval != 0) {
  91                         err(udevice->udev, "error changing netif name %s to %s: %m\n",
  92                             ifr.ifr_name, ifr.ifr_newname);
  93                         goto exit;
  94                 }
  95
  96                 /* wait 30 seconds for our target to become available */
  97                 util_strlcpy(ifr.ifr_name, ifr.ifr_newname, IFNAMSIZ);
  98                 util_strlcpy(ifr.ifr_newname, udevice->name, IFNAMSIZ);
  99                 loop = 30 * 20;
 100                 while (loop--) {
 101                         retval = ioctl(sk, SIOCSIFNAME, &ifr);
 102                         if (retval == 0) {
 103                                 kernel_log(ifr);
 104                                 break;
 105                         }
 106
 107                         if (errno != EEXIST) {
 108                                 err(udevice->udev, "error changing net interface name %s to %s: %m\n",
 109                                     ifr.ifr_name, ifr.ifr_newname);
 110                                 break;
 111                         }
 112                         dbg(udevice->udev, "wait for netif '%s' to become free, loop=%i\n",
 113                             udevice->name, (30 * 20) - loop);
 114                         usleep(1000 * 1000 / 20);
 115                 }
 116         }
 117
 118 exit:
 119         close(sk);
 120         return retval;
 121 }
 122
 123 int udev_device_event(struct udev_rules *rules, struct udevice *udevice)
 124 {
 125         int retval = 0;
 126
 127         if (udevice->devpath_old != NULL)
 128                 if (udev_db_rename(udevice->udev, udevice->devpath_old, udevice->dev->devpath) == 0)
 129                         info(udevice->udev, "moved database from '%s' to '%s'\n", udevice->devpath_old, udevice->dev->devpath);
 130
 131         /* add device node */
 132         if (major(udevice->devt) != 0 &&
 133             (strcmp(udevice->action, "add") == 0 || strcmp(udevice->action, "change") == 0)) {
 134                 struct udevice *udevice_old;
 135
 136                 dbg(udevice->udev, "device node add '%s'\n", udevice->dev->devpath);
 137
 138                 udev_rules_get_name(rules, udevice);
 139                 if (udevice->ignore_device) {
 140                         info(udevice->udev, "device event will be ignored\n");
 141                         goto exit;
 142                 }
 143                 if (udevice->name[0] == '\0') {
 144                         info(udevice->udev, "device node creation supressed\n");
 145                         goto exit;
 146                 }
 147
 148                 /* read current database entry; cleanup, if it is known device */
 149                 udevice_old = udev_device_init(udevice->udev);
 150                 if (udevice_old != NULL) {
 151                         udevice_old->test_run = udevice->test_run;
 152                         if (udev_db_get_device(udevice_old, udevice->dev->devpath) == 0) {
 153                                 info(udevice->udev, "device '%s' already in database, cleanup\n", udevice->dev->devpath);
 154                                 udev_db_delete_device(udevice_old);
 155                         } else {
 156                                 udev_device_cleanup(udevice_old);
 157                                 udevice_old = NULL;
 158                         }
 159                 }
 160
 161                 /* create node */
 162                 retval = udev_node_add(udevice);
 163                 if (retval != 0)
 164                         goto exit;
 165
 166                 /* store in database */
 167                 udev_db_add_device(udevice);
 168
 169                 /* create, replace, delete symlinks according to priority */
 170                 udev_node_update_symlinks(udevice, udevice_old);
 171
 172                 if (udevice_old != NULL)
 173                         udev_device_cleanup(udevice_old);
 174                 goto exit;
 175         }
 176
 177         /* add netif */
 178         if (strcmp(udevice->dev->subsystem, "net") == 0 && strcmp(udevice->action, "add") == 0) {
 179                 dbg(udevice->udev, "netif add '%s'\n", udevice->dev->devpath);
 180                 udev_rules_get_name(rules, udevice);
 181                 if (udevice->ignore_device) {
 182                         info(udevice->udev, "device event will be ignored\n");
 183                         goto exit;
 184                 }
 185                 if (udevice->name[0] == '\0') {
 186                         info(udevice->udev, "device renaming supressed\n");
 187                         goto exit;
 188                 }
 189
 190                 /* look if we want to change the name of the netif */
 191                 if (strcmp(udevice->name, udevice->dev->kernel) != 0) {
 192                         char devpath[PATH_MAX];
 193                         char *pos;
 194
 195                         retval = rename_netif(udevice);
 196                         if (retval != 0)
 197                                 goto exit;
 198                         info(udevice->udev, "renamed netif to '%s'\n", udevice->name);
 199
 200                         /* export old name */
 201                         setenv("INTERFACE_OLD", udevice->dev->kernel, 1);
 202
 203                         /* now change the devpath, because the kernel device name has changed */
 204                         util_strlcpy(devpath, udevice->dev->devpath, sizeof(devpath));
 205                         pos = strrchr(devpath, '/');
 206                         if (pos != NULL) {
 207                                 pos[1] = '\0';
 208                                 util_strlcat(devpath, udevice->name, sizeof(devpath));
 209                                 sysfs_device_set_values(udevice->udev, udevice->dev, devpath, NULL, NULL);
 210                                 setenv("DEVPATH", udevice->dev->devpath, 1);
 211                                 setenv("INTERFACE", udevice->name, 1);
 212                                 info(udevice->udev, "changed devpath to '%s'\n", udevice->dev->devpath);
 213                         }
 214                 }
 215                 goto exit;
 216         }
 217
 218         /* remove device node */
 219         if (major(udevice->devt) != 0 && strcmp(udevice->action, "remove") == 0) {
 220                 struct name_entry *name_loop;
 221
 222                 /* import database entry, and delete it */
 223                 if (udev_db_get_device(udevice, udevice->dev->devpath) == 0) {
 224                         udev_db_delete_device(udevice);
 225                         /* restore stored persistent data */
 226                         list_for_each_entry(name_loop, &udevice->env_list, node)
 227                                 putenv(name_loop->name);
 228                 } else {
 229                         dbg(udevice->udev, "'%s' not found in database, using kernel name '%s'\n",
 230                             udevice->dev->devpath, udevice->dev->kernel);
 231                         util_strlcpy(udevice->name, udevice->dev->kernel, sizeof(udevice->name));
 232                 }
 233
 234                 udev_rules_get_run(rules, udevice);
 235                 if (udevice->ignore_device) {
 236                         info(udevice->udev, "device event will be ignored\n");
 237                         goto exit;
 238                 }
 239
 240                 if (udevice->ignore_remove) {
 241                         info(udevice->udev, "ignore_remove for '%s'\n", udevice->name);
 242                         goto exit;
 243                 }
 244                 /* remove the node */
 245                 retval = udev_node_remove(udevice);
 246
 247                 /* delete or restore symlinks according to priority */
 248                 udev_node_update_symlinks(udevice, NULL);
 249                 goto exit;
 250         }
 251
 252         /* default devices */
 253         udev_rules_get_run(rules, udevice);
 254         if (udevice->ignore_device)
 255                 info(udevice->udev, "device event will be ignored\n");
 256
 257 exit:
 258         return retval;
 259 }