udev/udev-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
  33 struct udev_event *udev_event_new(struct udev_device *dev)
  34 {
  35         struct udev_event *event;
  36
  37         event = malloc(sizeof(struct udev_event));
  38         if (event == NULL)
  39                 return NULL;
  40         memset(event, 0x00, sizeof(struct udev_event));
  41
  42         event->dev = dev;
  43         event->udev = udev_device_get_udev(dev);
  44         udev_list_init(&event->run_list);
  45         event->mode = 0660;
  46         util_strlcpy(event->owner, "0", sizeof(event->owner));
  47         util_strlcpy(event->group, "0", sizeof(event->group));
  48
  49         dbg(event->udev, "allocated event %p\n", event);
  50         return event;
  51 }
  52
  53 void udev_event_unref(struct udev_event *event)
  54 {
  55         udev_list_cleanup(event->udev, &event->run_list);
  56         dbg(event->udev, "free event %p\n", event);
  57         free(event);
  58 }
  59
  60 static void kernel_log(struct ifreq ifr)
  61 {
  62         int klog;
  63         FILE *f;
  64
  65         klog = open("/dev/kmsg", O_WRONLY);
  66         if (klog < 0)
  67                 return;
  68
  69         f = fdopen(klog, "w");
  70         if (f == NULL) {
  71                 close(klog);
  72                 return;
  73         }
  74
  75         fprintf(f, "<6>udev: renamed network interface %s to %s\n",
  76                 ifr.ifr_name, ifr.ifr_newname);
  77         fclose(f);
  78 }
  79
  80 static int rename_netif(struct udev_event *event)
  81 {
  82         struct udev_device *dev = event->dev;
  83         int sk;
  84         struct ifreq ifr;
  85         int err;
  86
  87         info(event->udev, "changing net interface name from '%s' to '%s'\n",
  88              udev_device_get_sysname(dev), event->name);
  89         if (event->test)
  90                 return 0;
  91
  92         sk = socket(PF_INET, SOCK_DGRAM, 0);
  93         if (sk < 0) {
  94                 err(event->udev, "error opening socket: %m\n");
  95                 return -1;
  96         }
  97
  98         memset(&ifr, 0x00, sizeof(struct ifreq));
  99         util_strlcpy(ifr.ifr_name, udev_device_get_sysname(dev), IFNAMSIZ);
 100         util_strlcpy(ifr.ifr_newname, event->name, IFNAMSIZ);
 101         err = ioctl(sk, SIOCSIFNAME, &ifr);
 102         if (err == 0)
 103                 kernel_log(ifr);
 104         else {
 105                 int loop;
 106
 107                 /* see if the destination interface name already exists */
 108                 if (errno != EEXIST) {
 109                         err(event->udev, "error changing netif name %s to %s: %m\n",
 110                             ifr.ifr_name, ifr.ifr_newname);
 111                         goto exit;
 112                 }
 113
 114                 /* free our own name, another process may wait for us */
 115                 util_strlcpy(ifr.ifr_newname, udev_device_get_sysname(dev), IFNAMSIZ);
 116                 util_strlcat(ifr.ifr_newname, "_rename", IFNAMSIZ);
 117                 err = ioctl(sk, SIOCSIFNAME, &ifr);
 118                 if (err != 0) {
 119                         err(event->udev, "error changing netif name %s to %s: %m\n",
 120                             ifr.ifr_name, ifr.ifr_newname);
 121                         goto exit;
 122                 }
 123
 124                 /* wait 30 seconds for our target to become available */
 125                 util_strlcpy(ifr.ifr_name, ifr.ifr_newname, IFNAMSIZ);
 126                 util_strlcpy(ifr.ifr_newname, udev_device_get_devnode(dev), IFNAMSIZ);
 127                 loop = 30 * 20;
 128                 while (loop--) {
 129                         err = ioctl(sk, SIOCSIFNAME, &ifr);
 130                         if (err == 0) {
 131                                 kernel_log(ifr);
 132                                 break;
 133                         }
 134
 135                         if (errno != EEXIST) {
 136                                 err(event->udev, "error changing net interface name %s to %s: %m\n",
 137                                     ifr.ifr_name, ifr.ifr_newname);
 138                                 break;
 139                         }
 140                         dbg(event->udev, "wait for netif '%s' to become free, loop=%i\n",
 141                             udev_device_get_devnode(dev), (30 * 20) - loop);
 142                         usleep(1000 * 1000 / 20);
 143                 }
 144         }
 145 exit:
 146         close(sk);
 147         return err;
 148 }
 149
 150 int udev_event_execute_rules(struct udev_event *event, struct udev_rules *rules)
 151 {
 152         struct udev_device *dev = event->dev;
 153         int err = 0;
 154
 155         if (udev_device_get_devpath_old(dev) != NULL) {
 156                 if (udev_device_rename_db(dev, udev_device_get_devpath(dev)) == 0)
 157                         info(event->udev, "moved database from '%s' to '%s'\n",
 158                              udev_device_get_devpath_old(dev), udev_device_get_devpath(dev));
 159         }
 160
 161         /* add device node */
 162         if (major(udev_device_get_devnum(dev)) != 0 &&
 163             (strcmp(udev_device_get_action(dev), "add") == 0 || strcmp(udev_device_get_action(dev), "change") == 0)) {
 164                 char filename[UTIL_PATH_SIZE];
 165                 struct udev_device *dev_old;
 166
 167                 dbg(event->udev, "device node add '%s'\n", udev_device_get_devpath(dev));
 168
 169                 udev_rules_get_name(rules, event);
 170                 if (event->ignore_device) {
 171                         info(event->udev, "device event will be ignored\n");
 172                         goto exit;
 173                 }
 174
 175                 if (event->name[0] == '\0') {
 176                         info(event->udev, "device node creation supressed\n");
 177                         goto exit;
 178                 }
 179
 180                 /* set device node name */
 181                 util_strlcpy(filename, udev_get_dev_path(event->udev), sizeof(filename));
 182                 util_strlcat(filename, "/", sizeof(filename));
 183                 util_strlcat(filename, event->name, sizeof(filename));
 184                 udev_device_set_devnode(dev, filename);
 185
 186                 /* read current database entry; cleanup, if it is known device */
 187                 dev_old = udev_device_new_from_syspath(event->udev, udev_device_get_syspath(dev));
 188                 if (dev_old != NULL) {
 189                         info(event->udev, "device '%s' already in database, updating\n",
 190                              udev_device_get_devpath(dev));
 191                         udev_node_update_old_links(dev, dev_old, event->test);
 192                         udev_device_unref(dev_old);
 193                 }
 194
 195                 udev_device_update_db(dev);
 196
 197                 err = udev_node_add(dev, event->mode, event->owner, event->group, event->test);
 198                 if (err != 0)
 199                         goto exit;
 200
 201                 goto exit;
 202         }
 203
 204         /* add netif */
 205         if (strcmp(udev_device_get_subsystem(dev), "net") == 0 && strcmp(udev_device_get_action(dev), "add") == 0) {
 206                 dbg(event->udev, "netif add '%s'\n", udev_device_get_devpath(dev));
 207
 208                 udev_rules_get_name(rules, event);
 209                 if (event->ignore_device) {
 210                         info(event->udev, "device event will be ignored\n");
 211                         goto exit;
 212                 }
 213                 if (event->name[0] == '\0') {
 214                         info(event->udev, "device renaming supressed\n");
 215                         goto exit;
 216                 }
 217
 218                 /* look if we want to change the name of the netif */
 219                 if (strcmp(event->name, udev_device_get_sysname(dev)) != 0) {
 220                         char syspath[UTIL_PATH_SIZE];
 221                         char *pos;
 222
 223                         err = rename_netif(event);
 224                         if (err != 0)
 225                                 goto exit;
 226                         info(event->udev, "renamed netif to '%s'\n", event->name);
 227
 228                         /* remember old name */
 229                         udev_device_add_property(dev, "INTERFACE_OLD", udev_device_get_sysname(dev));
 230
 231                         /* now change the devpath, because the kernel device name has changed */
 232                         util_strlcpy(syspath, udev_device_get_syspath(dev), sizeof(syspath));
 233                         pos = strrchr(syspath, '/');
 234                         if (pos != NULL) {
 235                                 pos[1] = '\0';
 236                                 util_strlcat(syspath, event->name, sizeof(syspath));
 237                                 udev_device_set_syspath(event->dev, syspath);
 238                                 udev_device_add_property(dev, "INTERFACE", udev_device_get_sysname(dev));
 239                                 info(event->udev, "changed devpath to '%s'\n", udev_device_get_devpath(dev));
 240                         }
 241                 }
 242                 goto exit;
 243         }
 244
 245         /* remove device node */
 246         if (major(udev_device_get_devnum(dev)) != 0 && strcmp(udev_device_get_action(dev), "remove") == 0) {
 247                 /* import database entry and delete it */
 248                 udev_device_read_db(dev);
 249                 if (!event->test)
 250                         udev_device_delete_db(dev);
 251
 252                 if (udev_device_get_devnode(dev) == NULL) {
 253                         char devnode[UTIL_PATH_SIZE];
 254
 255                         info(event->udev, "'%s' not found in database, using kernel name '%s'\n",
 256                              udev_device_get_syspath(dev), udev_device_get_sysname(dev));
 257                         util_strlcpy(devnode, udev_get_dev_path(event->udev), sizeof(devnode));
 258                         util_strlcat(devnode, "/", sizeof(devnode));
 259                         util_strlcat(devnode, udev_device_get_sysname(dev), sizeof(devnode));
 260                         udev_device_set_devnode(dev, devnode);
 261                 }
 262
 263                 udev_rules_get_run(rules, event);
 264                 if (event->ignore_device) {
 265                         info(event->udev, "device event will be ignored\n");
 266                         goto exit;
 267                 }
 268
 269                 if (udev_device_get_ignore_remove(dev)) {
 270                         info(event->udev, "ignore_remove for '%s'\n", udev_device_get_devnode(dev));
 271                         goto exit;
 272                 }
 273
 274                 err = udev_node_remove(dev, event->test);
 275                 goto exit;
 276         }
 277
 278         /* default devices */
 279         udev_rules_get_run(rules, event);
 280         if (event->ignore_device)
 281                 info(event->udev, "device event will be ignored\n");
 282 exit:
 283         return err;
 284 }