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
  35 static void kernel_log(struct ifreq ifr)
  36 {
  37         int klog;
  38         FILE *f;
  39
  40         klog = open("/dev/kmsg", O_WRONLY);
  41         if (klog < 0)
  42                 return;
  43
  44         f = fdopen(klog, "w");
  45         if (f == NULL) {
  46                 close(klog);
  47                 return;
  48         }
  49
  50         fprintf(f, "<6>udev: renamed network interface %s to %s\n",
  51                 ifr.ifr_name, ifr.ifr_newname);
  52         fclose(f);
  53 }
  54
  55 static int rename_netif(struct udevice *udevice)
  56 {
  57         int sk;
  58         struct ifreq ifr;
  59         int retval;
  60
  61         info(udevice->udev, "changing net interface name from '%s' to '%s'\n", udevice->dev->kernel, udevice->name);
  62         if (udevice->test_run)
  63                 return 0;
  64
  65         sk = socket(PF_INET, SOCK_DGRAM, 0);
  66         if (sk < 0) {
  67                 err(udevice->udev, "error opening socket: %s\n", strerror(errno));
  68                 return -1;
  69         }
  70
  71         memset(&ifr, 0x00, sizeof(struct ifreq));
  72         strlcpy(ifr.ifr_name, udevice->dev->kernel, IFNAMSIZ);
  73         strlcpy(ifr.ifr_newname, udevice->name, IFNAMSIZ);
  74         retval = ioctl(sk, SIOCSIFNAME, &ifr);
  75         if (retval == 0)
  76                 kernel_log(ifr);
  77         else {
  78                 int loop;
  79
  80                 /* see if the destination interface name already exists */
  81                 if (errno != EEXIST) {
  82                         err(udevice->udev, "error changing netif name %s to %s: %s\n", ifr.ifr_name, ifr.ifr_newname, strerror(errno));
  83                         goto exit;
  84                 }
  85
  86                 /* free our own name, another process may wait for us */
  87                 strlcpy(ifr.ifr_newname, udevice->dev->kernel, IFNAMSIZ);
  88                 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: %s\n", ifr.ifr_name, ifr.ifr_newname, strerror(errno));
  92                         goto exit;
  93                 }
  94
  95                 /* wait 30 seconds for our target to become available */
  96                 strlcpy(ifr.ifr_name, ifr.ifr_newname, IFNAMSIZ);
  97                 strlcpy(ifr.ifr_newname, udevice->name, IFNAMSIZ);
  98                 loop = 30 * 20;
  99                 while (loop--) {
 100                         retval = ioctl(sk, SIOCSIFNAME, &ifr);
 101                         if (retval == 0) {
 102                                 kernel_log(ifr);
 103                                 break;
 104                         }
 105
 106                         if (errno != EEXIST) {
 107                                 err(udevice->udev, "error changing net interface name %s to %s: %s\n",
 108                                     ifr.ifr_name, ifr.ifr_newname, strerror(errno));
 109                                 break;
 110                         }
 111                         dbg(udevice->udev, "wait for netif '%s' to become free, loop=%i\n", udevice->name, (30 * 20) - loop);
 112                         usleep(1000 * 1000 / 20);
 113                 }
 114         }
 115
 116 exit:
 117         close(sk);
 118         return retval;
 119 }
 120
 121 int udev_device_event(struct udev_rules *rules, struct udevice *udevice)
 122 {
 123         int retval = 0;
 124
 125         if (udevice->devpath_old != NULL)
 126                 if (udev_db_rename(udevice->udev, udevice->devpath_old, udevice->dev->devpath) == 0)
 127                         info(udevice->udev, "moved database from '%s' to '%s'\n", udevice->devpath_old, udevice->dev->devpath);
 128
 129         /* add device node */
 130         if (major(udevice->devt) != 0 &&
 131             (strcmp(udevice->action, "add") == 0 || strcmp(udevice->action, "change") == 0)) {
 132                 struct udevice *udevice_old;
 133
 134                 dbg(udevice->udev, "device node add '%s'\n", udevice->dev->devpath);
 135
 136                 udev_rules_get_name(rules, udevice);
 137                 if (udevice->ignore_device) {
 138                         info(udevice->udev, "device event will be ignored\n");
 139                         goto exit;
 140                 }
 141                 if (udevice->name[0] == '\0') {
 142                         info(udevice->udev, "device node creation supressed\n");
 143                         goto exit;
 144                 }
 145
 146                 /* read current database entry; cleanup, if it is known device */
 147                 udevice_old = udev_device_init(udevice->udev);
 148                 if (udevice_old != NULL) {
 149                         udevice_old->test_run = udevice->test_run;
 150                         if (udev_db_get_device(udevice_old, udevice->dev->devpath) == 0) {
 151                                 info(udevice->udev, "device '%s' already in database, cleanup\n", udevice->dev->devpath);
 152                                 udev_db_delete_device(udevice_old);
 153                         } else {
 154                                 udev_device_cleanup(udevice_old);
 155                                 udevice_old = NULL;
 156                         }
 157                 }
 158
 159                 /* create node */
 160                 retval = udev_node_add(udevice);
 161                 if (retval != 0)
 162                         goto exit;
 163
 164                 /* store in database */
 165                 udev_db_add_device(udevice);
 166
 167                 /* create, replace, delete symlinks according to priority */
 168                 udev_node_update_symlinks(udevice, udevice_old);
 169
 170                 if (udevice_old != NULL)
 171                         udev_device_cleanup(udevice_old);
 172                 goto exit;
 173         }
 174
 175         /* add netif */
 176         if (strcmp(udevice->dev->subsystem, "net") == 0 && strcmp(udevice->action, "add") == 0) {
 177                 dbg(udevice->udev, "netif add '%s'\n", udevice->dev->devpath);
 178                 udev_rules_get_name(rules, udevice);
 179                 if (udevice->ignore_device) {
 180                         info(udevice->udev, "device event will be ignored\n");
 181                         goto exit;
 182                 }
 183                 if (udevice->name[0] == '\0') {
 184                         info(udevice->udev, "device renaming supressed\n");
 185                         goto exit;
 186                 }
 187
 188                 /* look if we want to change the name of the netif */
 189                 if (strcmp(udevice->name, udevice->dev->kernel) != 0) {
 190                         char devpath[PATH_MAX];
 191                         char *pos;
 192
 193                         retval = rename_netif(udevice);
 194                         if (retval != 0)
 195                                 goto exit;
 196                         info(udevice->udev, "renamed netif to '%s'\n", udevice->name);
 197
 198                         /* export old name */
 199                         setenv("INTERFACE_OLD", udevice->dev->kernel, 1);
 200
 201                         /* now change the devpath, because the kernel device name has changed */
 202                         strlcpy(devpath, udevice->dev->devpath, sizeof(devpath));
 203                         pos = strrchr(devpath, '/');
 204                         if (pos != NULL) {
 205                                 pos[1] = '\0';
 206                                 strlcat(devpath, udevice->name, sizeof(devpath));
 207                                 sysfs_device_set_values(udevice->udev, udevice->dev, devpath, NULL, NULL);
 208                                 setenv("DEVPATH", udevice->dev->devpath, 1);
 209                                 setenv("INTERFACE", udevice->name, 1);
 210                                 info(udevice->udev, "changed devpath to '%s'\n", udevice->dev->devpath);
 211                         }
 212                 }
 213                 goto exit;
 214         }
 215
 216         /* remove device node */
 217         if (major(udevice->devt) != 0 && strcmp(udevice->action, "remove") == 0) {
 218                 struct name_entry *name_loop;
 219
 220                 /* import database entry, and delete it */
 221                 if (udev_db_get_device(udevice, udevice->dev->devpath) == 0) {
 222                         udev_db_delete_device(udevice);
 223                         /* restore stored persistent data */
 224                         list_for_each_entry(name_loop, &udevice->env_list, node)
 225                                 putenv(name_loop->name);
 226                 } else {
 227                         dbg(udevice->udev, "'%s' not found in database, using kernel name '%s'\n",
 228                             udevice->dev->devpath, udevice->dev->kernel);
 229                         strlcpy(udevice->name, udevice->dev->kernel, sizeof(udevice->name));
 230                 }
 231
 232                 udev_rules_get_run(rules, udevice);
 233                 if (udevice->ignore_device) {
 234                         info(udevice->udev, "device event will be ignored\n");
 235                         goto exit;
 236                 }
 237
 238                 if (udevice->ignore_remove) {
 239                         info(udevice->udev, "ignore_remove for '%s'\n", udevice->name);
 240                         goto exit;
 241                 }
 242                 /* remove the node */
 243                 retval = udev_node_remove(udevice);
 244
 245                 /* delete or restore symlinks according to priority */
 246                 udev_node_update_symlinks(udevice, NULL);
 247                 goto exit;
 248         }
 249
 250         /* default devices */
 251         udev_rules_get_run(rules, udevice);
 252         if (udevice->ignore_device)
 253                 info(udevice->udev, "device event will be ignored\n");
 254
 255 exit:
 256         return retval;
 257 }