udev_device.c

   1 /*
   2  * Copyright (C) 2004-2006 Kay Sievers <kay.sievers@vrfy.org>
   3  *
   4  *      This program is free software; you can redistribute it and/or modify it
   5  *      under the terms of the GNU General Public License as published by the
   6  *      Free Software Foundation version 2 of the License.
   7  *
   8  *      This program is distributed in the hope that it will be useful, but
   9  *      WITHOUT ANY WARRANTY; without even the implied warranty of
  10  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  *      General Public License for more details.
  12  *
  13  *      You should have received a copy of the GNU General Public License along
  14  *      with this program; if not, write to the Free Software Foundation, Inc.,
  15  *      51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  16  *
  17  */
  18
  19
  20 #include <stdlib.h>
  21 #include <stdio.h>
  22 #include <stddef.h>
  23 #include <unistd.h>
  24 #include <fcntl.h>
  25 #include <errno.h>
  26 #include <ctype.h>
  27 #include <sys/ioctl.h>
  28 #include <sys/socket.h>
  29 #include <net/if.h>
  30 #include <linux/sockios.h>
  31
  32 #include "udev.h"
  33 #include "udev_rules.h"
  34
  35
  36 struct udevice *udev_device_init(struct udevice *udev)
  37 {
  38         if (udev == NULL)
  39                 udev = malloc(sizeof(struct udevice));
  40         if (udev == NULL)
  41                 return NULL;
  42         memset(udev, 0x00, sizeof(struct udevice));
  43
  44         INIT_LIST_HEAD(&udev->symlink_list);
  45         INIT_LIST_HEAD(&udev->run_list);
  46         INIT_LIST_HEAD(&udev->env_list);
  47
  48         /* set sysfs device to local storage, can be overridden if needed */
  49         udev->dev = &udev->dev_local;
  50
  51         /* default node permissions */
  52         udev->mode = 0660;
  53         strcpy(udev->owner, "root");
  54         strcpy(udev->group, "root");
  55
  56         return udev;
  57 }
  58
  59 void udev_device_cleanup(struct udevice *udev)
  60 {
  61         name_list_cleanup(&udev->symlink_list);
  62         name_list_cleanup(&udev->run_list);
  63         name_list_cleanup(&udev->env_list);
  64         free(udev);
  65 }
  66
  67 dev_t udev_device_get_devt(struct udevice *udev)
  68 {
  69         const char *attr;
  70         unsigned int maj, min;
  71
  72         /* read it from sysfs  */
  73         attr = sysfs_attr_get_value(udev->dev->devpath, "dev");
  74         if (attr != NULL) {
  75                 if (sscanf(attr, "%u:%u", &maj, &min) == 2)
  76                         return makedev(maj, min);
  77         }
  78         return makedev(0, 0);
  79 }
  80
  81 static int rename_netif(struct udevice *udev)
  82 {
  83         int sk;
  84         struct ifreq ifr;
  85         int retval;
  86
  87         info("changing net interface name from '%s' to '%s'", udev->dev->kernel, udev->name);
  88         if (udev->test_run)
  89                 return 0;
  90
  91         sk = socket(PF_INET, SOCK_DGRAM, 0);
  92         if (sk < 0) {
  93                 err("error opening socket: %s", strerror(errno));
  94                 return -1;
  95         }
  96
  97         memset(&ifr, 0x00, sizeof(struct ifreq));
  98         strlcpy(ifr.ifr_name, udev->dev->kernel, IFNAMSIZ);
  99         strlcpy(ifr.ifr_newname, udev->name, IFNAMSIZ);
 100         retval = ioctl(sk, SIOCSIFNAME, &ifr);
 101         if (retval != 0) {
 102                 int loop;
 103
 104                 /* see if the destination interface name already exists */
 105                 if (errno != EEXIST) {
 106                         err("error changing netif name %s to %s: %s", ifr.ifr_name, ifr.ifr_newname, strerror(errno));
 107                         goto exit;
 108                 }
 109
 110                 /* free our own name, another process may wait for us */
 111                 strlcpy(ifr.ifr_newname, udev->dev->kernel, IFNAMSIZ);
 112                 strlcat(ifr.ifr_newname, "_rename", IFNAMSIZ);
 113                 retval = ioctl(sk, SIOCSIFNAME, &ifr);
 114                 if (retval != 0) {
 115                         err("error changing netif name %s to %s: %s", ifr.ifr_name, ifr.ifr_newname, strerror(errno));
 116                         goto exit;
 117                 }
 118
 119                 /* wait 30 seconds for our target to become available */
 120                 strlcpy(ifr.ifr_name, ifr.ifr_newname, IFNAMSIZ);
 121                 strlcpy(ifr.ifr_newname, udev->name, IFNAMSIZ);
 122                 loop = 30 * 20;
 123                 while (loop--) {
 124                         retval = ioctl(sk, SIOCSIFNAME, &ifr);
 125                         if (retval == 0)
 126                                 break;
 127
 128                         if (errno != EEXIST) {
 129                                 err("error changing net interface name %s to %s: %s",
 130                                     ifr.ifr_name, ifr.ifr_newname, strerror(errno));
 131                                 break;
 132                         }
 133                         dbg("wait for netif '%s' to become free, loop=%i", udev->name, (30 * 20) - loop);
 134                         usleep(1000 * 1000 / 20);
 135                 }
 136         }
 137
 138 exit:
 139         close(sk);
 140         return retval;
 141 }
 142
 143 int udev_device_event(struct udev_rules *rules, struct udevice *udev)
 144 {
 145         int retval = 0;
 146
 147         /* add device node */
 148         if (major(udev->devt) != 0 &&
 149             (strcmp(udev->action, "add") == 0 || strcmp(udev->action, "change") == 0)) {
 150                 struct udevice *udev_old;
 151
 152                 dbg("device node add '%s'", udev->dev->devpath);
 153
 154                 udev_rules_get_name(rules, udev);
 155                 if (udev->ignore_device) {
 156                         info("device event will be ignored");
 157                         goto exit;
 158                 }
 159                 if (udev->name[0] == '\0') {
 160                         info("device node creation supressed");
 161                         goto exit;
 162                 }
 163
 164                 /* read current database entry; cleanup, if it is known device */
 165                 udev_old = udev_device_init(NULL);
 166                 if (udev_old != NULL) {
 167                         if (udev_db_get_device(udev_old, udev->dev->devpath) == 0) {
 168                                 info("device '%s' already in database, cleanup", udev->dev->devpath);
 169                                 udev_db_delete_device(udev_old);
 170                         } else {
 171                                 udev_device_cleanup(udev_old);
 172                                 udev_old = NULL;
 173                         }
 174                 }
 175
 176                 /* create node and symlinks */
 177                 retval = udev_node_add(udev, udev_old);
 178                 if (retval == 0)
 179                         udev_db_add_device(udev);
 180
 181                 /* remove possibly left-over symlinks */
 182                 if (udev_old != NULL) {
 183                         struct name_entry *link_loop;
 184                         struct name_entry *link_old_loop;
 185                         struct name_entry *link_old_tmp_loop;
 186
 187                         /* remove still valid symlinks from old list */
 188                         list_for_each_entry_safe(link_old_loop, link_old_tmp_loop, &udev_old->symlink_list, node)
 189                                 list_for_each_entry(link_loop, &udev->symlink_list, node)
 190                                         if (strcmp(link_old_loop->name, link_loop->name) == 0) {
 191                                                 dbg("symlink '%s' still valid, keep it", link_old_loop->name);
 192                                                 list_del(&link_old_loop->node);
 193                                                 free(link_old_loop);
 194                                         }
 195                         udev_node_remove_symlinks(udev_old);
 196                         udev_device_cleanup(udev_old);
 197                 }
 198                 goto exit;
 199         }
 200
 201         /* add netif */
 202         if (strcmp(udev->dev->subsystem, "net") == 0 && strcmp(udev->action, "add") == 0) {
 203                 dbg("netif add '%s'", udev->dev->devpath);
 204                 udev_rules_get_name(rules, udev);
 205                 if (udev->ignore_device) {
 206                         info("device event will be ignored");
 207                         goto exit;
 208                 }
 209                 if (udev->name[0] == '\0') {
 210                         info("device renaming supressed");
 211                         goto exit;
 212                 }
 213
 214                 /* look if we want to change the name of the netif */
 215                 if (strcmp(udev->name, udev->dev->kernel) != 0) {
 216                         char *pos;
 217
 218                         retval = rename_netif(udev);
 219                         if (retval != 0)
 220                                 goto exit;
 221                         info("renamed netif to '%s'", udev->name);
 222
 223                         /* export old name */
 224                         setenv("INTERFACE_OLD", udev->dev->kernel, 1);
 225
 226                         /* now fake the devpath, because the kernel name changed silently */
 227                         pos = strrchr(udev->dev->devpath, '/');
 228                         if (pos != NULL) {
 229                                 pos[1] = '\0';
 230                                 strlcat(udev->dev->devpath, udev->name, sizeof(udev->dev->devpath));
 231                                 strlcpy(udev->dev->kernel, udev->name, sizeof(udev->dev->kernel));
 232                                 setenv("DEVPATH", udev->dev->devpath, 1);
 233                                 setenv("INTERFACE", udev->name, 1);
 234                         }
 235                 }
 236                 goto exit;
 237         }
 238
 239         /* remove device node */
 240         if (major(udev->devt) != 0 && strcmp(udev->action, "remove") == 0) {
 241                 struct name_entry *name_loop;
 242
 243                 /* import database entry, and delete it */
 244                 if (udev_db_get_device(udev, udev->dev->devpath) == 0) {
 245                         udev_db_delete_device(udev);
 246                         if (udev->ignore_remove) {
 247                                 dbg("remove event for '%s' requested to be ignored by rule", udev->name);
 248                                 return 0;
 249                         }
 250                         /* restore stored persistent data */
 251                         list_for_each_entry(name_loop, &udev->env_list, node)
 252                                 putenv(name_loop->name);
 253                 } else {
 254                         dbg("'%s' not found in database, using kernel name '%s'", udev->dev->devpath, udev->dev->kernel);
 255                         strlcpy(udev->name, udev->dev->kernel, sizeof(udev->name));
 256                 }
 257
 258                 udev_rules_get_run(rules, udev);
 259                 if (udev->ignore_device) {
 260                         info("device event will be ignored");
 261                         goto exit;
 262                 }
 263
 264                 retval = udev_node_remove(udev);
 265                 goto exit;
 266         }
 267
 268         /* default devices */
 269         udev_rules_get_run(rules, udev);
 270         if (udev->ignore_device)
 271                 info("device event will be ignored");
 272
 273 exit:
 274         return retval;
 275 }