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 struct udev_event *udev_event_new(struct udev_device *dev)
  35 {
  36         struct udev_event *event;
  37
  38         event = malloc(sizeof(struct udev_event));
  39         if (event == NULL)
  40                 return NULL;
  41         memset(event, 0x00, sizeof(struct udev_event));
  42
  43         event->dev = dev;
  44         event->udev = udev_device_get_udev(dev);
  45         udev_list_init(&event->run_list);
  46         event->mode = 0660;
  47         util_strlcpy(event->owner, "0", sizeof(event->owner));
  48         util_strlcpy(event->group, "0", sizeof(event->group));
  49
  50         dbg(event->udev, "allocated event %p\n", event);
  51         return event;
  52 }
  53
  54 void udev_event_unref(struct udev_event *event)
  55 {
  56         udev_list_cleanup(event->udev, &event->run_list);
  57         dbg(event->udev, "free event %p\n", event);
  58         free(event);
  59 }
  60
  61 static void kernel_log(struct ifreq ifr)
  62 {
  63         int klog;
  64         FILE *f;
  65
  66         klog = open("/dev/kmsg", O_WRONLY);
  67         if (klog < 0)
  68                 return;
  69
  70         f = fdopen(klog, "w");
  71         if (f == NULL) {
  72                 close(klog);
  73                 return;
  74         }
  75
  76         fprintf(f, "<6>udev: renamed network interface %s to %s\n",
  77                 ifr.ifr_name, ifr.ifr_newname);
  78         fclose(f);
  79 }
  80
  81 static int rename_netif(struct udev_event *event)
  82 {
  83         struct udev_device *dev = event->dev;
  84         int sk;
  85         struct ifreq ifr;
  86         int err;
  87
  88         info(event->udev, "changing net interface name from '%s' to '%s'\n",
  89              udev_device_get_sysname(dev), event->name);
  90         if (event->test)
  91                 return 0;
  92
  93         sk = socket(PF_INET, SOCK_DGRAM, 0);
  94         if (sk < 0) {
  95                 err(event->udev, "error opening socket: %m\n");
  96                 return -1;
  97         }
  98
  99         memset(&ifr, 0x00, sizeof(struct ifreq));
 100         util_strlcpy(ifr.ifr_name, udev_device_get_sysname(dev), IFNAMSIZ);
 101         util_strlcpy(ifr.ifr_newname, event->name, IFNAMSIZ);
 102         err = ioctl(sk, SIOCSIFNAME, &ifr);
 103         if (err == 0)
 104                 kernel_log(ifr);
 105         else {
 106                 int loop;
 107
 108                 /* see if the destination interface name already exists */
 109                 if (errno != EEXIST) {
 110                         err(event->udev, "error changing netif name %s to %s: %m\n",
 111                             ifr.ifr_name, ifr.ifr_newname);
 112                         goto exit;
 113                 }
 114
 115                 /* free our own name, another process may wait for us */
 116                 util_strlcpy(ifr.ifr_newname, udev_device_get_sysname(dev), IFNAMSIZ);
 117                 util_strlcat(ifr.ifr_newname, "_rename", IFNAMSIZ);
 118                 err = ioctl(sk, SIOCSIFNAME, &ifr);
 119                 if (err != 0) {
 120                         err(event->udev, "error changing netif name %s to %s: %m\n",
 121                             ifr.ifr_name, ifr.ifr_newname);
 122                         goto exit;
 123                 }
 124
 125                 /* wait 30 seconds for our target to become available */
 126                 util_strlcpy(ifr.ifr_name, ifr.ifr_newname, IFNAMSIZ);
 127                 util_strlcpy(ifr.ifr_newname, udev_device_get_devnode(dev), IFNAMSIZ);
 128                 loop = 30 * 20;
 129                 while (loop--) {
 130                         err = ioctl(sk, SIOCSIFNAME, &ifr);
 131                         if (err == 0) {
 132                                 kernel_log(ifr);
 133                                 break;
 134                         }
 135
 136                         if (errno != EEXIST) {
 137                                 err(event->udev, "error changing net interface name %s to %s: %m\n",
 138                                     ifr.ifr_name, ifr.ifr_newname);
 139                                 break;
 140                         }
 141                         dbg(event->udev, "wait for netif '%s' to become free, loop=%i\n",
 142                             udev_device_get_devnode(dev), (30 * 20) - loop);
 143                         usleep(1000 * 1000 / 20);
 144                 }
 145         }
 146
 147 exit:
 148         close(sk);
 149         return err;
 150 }
 151
 152 int udev_event_run(struct udev_event *event, struct udev_rules *rules)
 153 {
 154         struct udev_device *dev = event->dev;
 155         int err = 0;
 156
 157         if (udev_device_get_devpath_old(dev) != NULL) {
 158                 if (udev_device_rename_db(dev, udev_device_get_devpath(dev)) == 0)
 159                         info(event->udev, "moved database from '%s' to '%s'\n",
 160                              udev_device_get_devpath_old(dev), udev_device_get_devpath(dev));
 161         }
 162
 163         /* add device node */
 164         if (major(udev_device_get_devnum(dev)) != 0 &&
 165             (strcmp(udev_device_get_action(dev), "add") == 0 || strcmp(udev_device_get_action(dev), "change") == 0)) {
 166                 char filename[UTIL_PATH_SIZE];
 167                 struct udev_device *dev_old;
 168
 169                 dbg(event->udev, "device node add '%s'\n", udev_device_get_devpath(dev));
 170
 171                 udev_rules_get_name(rules, event);
 172                 if (event->ignore_device) {
 173                         info(event->udev, "device event will be ignored\n");
 174                         goto exit;
 175                 }
 176
 177                 if (event->name[0] == '\0') {
 178                         info(event->udev, "device node creation supressed\n");
 179                         goto exit;
 180                 }
 181
 182                 /* set device node name */
 183                 util_strlcpy(filename, udev_get_dev_path(event->udev), sizeof(filename));
 184                 util_strlcat(filename, "/", sizeof(filename));
 185                 util_strlcat(filename, event->name, sizeof(filename));
 186                 udev_device_set_devnode(dev, filename);
 187
 188                 /* read current database entry; cleanup, if it is known device */
 189                 dev_old = udev_device_new_from_syspath(event->udev, udev_device_get_syspath(dev));
 190                 if (dev_old != NULL) {
 191                         info(event->udev, "device '%s' already in database, updating\n",
 192                              udev_device_get_devpath(dev));
 193                         udev_node_update_old_links(dev, dev_old, event->test);
 194                         udev_device_unref(dev_old);
 195                 }
 196
 197                 udev_device_update_db(dev);
 198
 199                 err = udev_node_add(dev, event->mode, event->owner, event->group, event->test);
 200                 if (err != 0)
 201                         goto exit;
 202
 203                 goto exit;
 204         }
 205
 206         /* add netif */
 207         if (strcmp(udev_device_get_subsystem(dev), "net") == 0 && strcmp(udev_device_get_action(dev), "add") == 0) {
 208                 dbg(event->udev, "netif add '%s'\n", udev_device_get_devpath(dev));
 209
 210                 udev_rules_get_name(rules, event);
 211                 if (event->ignore_device) {
 212                         info(event->udev, "device event will be ignored\n");
 213                         goto exit;
 214                 }
 215                 if (event->name[0] == '\0') {
 216                         info(event->udev, "device renaming supressed\n");
 217                         goto exit;
 218                 }
 219
 220                 /* look if we want to change the name of the netif */
 221                 if (strcmp(event->name, udev_device_get_sysname(dev)) != 0) {
 222                         char syspath[UTIL_PATH_SIZE];
 223                         char *pos;
 224
 225                         err = rename_netif(event);
 226                         if (err != 0)
 227                                 goto exit;
 228                         info(event->udev, "renamed netif to '%s'\n", event->name);
 229
 230                         /* remember old name */
 231                         udev_device_add_property(dev, "INTERFACE_OLD", udev_device_get_sysname(dev));
 232
 233                         /* now change the devpath, because the kernel device name has changed */
 234                         util_strlcpy(syspath, udev_device_get_syspath(dev), sizeof(syspath));
 235                         pos = strrchr(syspath, '/');
 236                         if (pos != NULL) {
 237                                 pos[1] = '\0';
 238                                 util_strlcat(syspath, event->name, sizeof(syspath));
 239                                 udev_device_set_syspath(event->dev, syspath);
 240                                 udev_device_add_property(dev, "INTERFACE", udev_device_get_sysname(dev));
 241                                 info(event->udev, "changed devpath to '%s'\n", udev_device_get_devpath(dev));
 242                         }
 243                 }
 244                 goto exit;
 245         }
 246
 247         /* remove device node */
 248         if (major(udev_device_get_devnum(dev)) != 0 && strcmp(udev_device_get_action(dev), "remove") == 0) {
 249                 /* import database entry and delete it */
 250                 udev_device_read_db(dev);
 251                 if (!event->test)
 252                         udev_device_delete_db(dev);
 253
 254                 if (udev_device_get_devnode(dev) == NULL) {
 255                         char devnode[UTIL_PATH_SIZE];
 256
 257                         info(event->udev, "'%s' not found in database, using kernel name '%s'\n",
 258                              udev_device_get_syspath(dev), udev_device_get_sysname(dev));
 259                         util_strlcpy(devnode, udev_get_dev_path(event->udev), sizeof(devnode));
 260                         util_strlcat(devnode, "/", sizeof(devnode));
 261                         util_strlcat(devnode, udev_device_get_sysname(dev), sizeof(devnode));
 262                         udev_device_set_devnode(dev, devnode);
 263                 }
 264
 265                 udev_rules_get_run(rules, event);
 266                 if (event->ignore_device) {
 267                         info(event->udev, "device event will be ignored\n");
 268                         goto exit;
 269                 }
 270
 271                 if (udev_device_get_ignore_remove(dev)) {
 272                         info(event->udev, "ignore_remove for '%s'\n", udev_device_get_devnode(dev));
 273                         goto exit;
 274                 }
 275
 276                 err = udev_node_remove(dev, event->test);
 277                 goto exit;
 278         }
 279
 280         /* default devices */
 281         udev_rules_get_run(rules, event);
 282         if (event->ignore_device)
 283                 info(event->udev, "device event will be ignored\n");
 284 exit:
 285         return err;
 286 }