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         udev->event_timeout = -1;
  57
  58         return udev;
  59 }
  60
  61 void udev_device_cleanup(struct udevice *udev)
  62 {
  63         name_list_cleanup(&udev->symlink_list);
  64         name_list_cleanup(&udev->run_list);
  65         name_list_cleanup(&udev->env_list);
  66         free(udev);
  67 }
  68
  69 dev_t udev_device_get_devt(struct udevice *udev)
  70 {
  71         const char *attr;
  72         unsigned int maj, min;
  73
  74         /* read it from sysfs  */
  75         attr = sysfs_attr_get_value(udev->dev->devpath, "dev");
  76         if (attr != NULL) {
  77                 if (sscanf(attr, "%u:%u", &maj, &min) == 2)
  78                         return makedev(maj, min);
  79         }
  80         return makedev(0, 0);
  81 }
  82
  83 static void kernel_log(struct ifreq ifr)
  84 {
  85         int klog;
  86         FILE *f;
  87
  88         klog = open("/dev/kmsg", O_WRONLY);
  89         if (klog < 0)
  90                 return;
  91
  92         f = fdopen(klog, "w");
  93         if (f == NULL) {
  94                 close(klog);
  95                 return;
  96         }
  97
  98         fprintf(f, "<6>udev: renamed network interface %s to %s\n",
  99                 ifr.ifr_name, ifr.ifr_newname);
 100         fclose(f);
 101 }
 102
 103 static int rename_netif(struct udevice *udev)
 104 {
 105         int sk;
 106         struct ifreq ifr;
 107         int retval;
 108
 109         info("changing net interface name from '%s' to '%s'\n", udev->dev->kernel, udev->name);
 110         if (udev->test_run)
 111                 return 0;
 112
 113         sk = socket(PF_INET, SOCK_DGRAM, 0);
 114         if (sk < 0) {
 115                 err("error opening socket: %s\n", strerror(errno));
 116                 return -1;
 117         }
 118
 119         memset(&ifr, 0x00, sizeof(struct ifreq));
 120         strlcpy(ifr.ifr_name, udev->dev->kernel, IFNAMSIZ);
 121         strlcpy(ifr.ifr_newname, udev->name, IFNAMSIZ);
 122         retval = ioctl(sk, SIOCSIFNAME, &ifr);
 123         if (retval == 0)
 124                 kernel_log(ifr);
 125         else {
 126                 int loop;
 127
 128                 /* see if the destination interface name already exists */
 129                 if (errno != EEXIST) {
 130                         err("error changing netif name %s to %s: %s\n", ifr.ifr_name, ifr.ifr_newname, strerror(errno));
 131                         goto exit;
 132                 }
 133
 134                 /* free our own name, another process may wait for us */
 135                 strlcpy(ifr.ifr_newname, udev->dev->kernel, IFNAMSIZ);
 136                 strlcat(ifr.ifr_newname, "_rename", IFNAMSIZ);
 137                 retval = ioctl(sk, SIOCSIFNAME, &ifr);
 138                 if (retval != 0) {
 139                         err("error changing netif name %s to %s: %s\n", ifr.ifr_name, ifr.ifr_newname, strerror(errno));
 140                         goto exit;
 141                 }
 142
 143                 /* wait 30 seconds for our target to become available */
 144                 strlcpy(ifr.ifr_name, ifr.ifr_newname, IFNAMSIZ);
 145                 strlcpy(ifr.ifr_newname, udev->name, IFNAMSIZ);
 146                 loop = 30 * 20;
 147                 while (loop--) {
 148                         retval = ioctl(sk, SIOCSIFNAME, &ifr);
 149                         if (retval == 0) {
 150                                 kernel_log(ifr);
 151                                 break;
 152                         }
 153
 154                         if (errno != EEXIST) {
 155                                 err("error changing net interface name %s to %s: %s\n",
 156                                     ifr.ifr_name, ifr.ifr_newname, strerror(errno));
 157                                 break;
 158                         }
 159                         dbg("wait for netif '%s' to become free, loop=%i\n", udev->name, (30 * 20) - loop);
 160                         usleep(1000 * 1000 / 20);
 161                 }
 162         }
 163
 164 exit:
 165         close(sk);
 166         return retval;
 167 }
 168
 169 int udev_device_event(struct udev_rules *rules, struct udevice *udev)
 170 {
 171         int retval = 0;
 172
 173         if (udev->devpath_old != NULL)
 174                 if (udev_db_rename(udev->devpath_old, udev->dev->devpath) == 0)
 175                         info("moved database from '%s' to '%s'\n", udev->devpath_old, udev->dev->devpath);
 176
 177         /* add device node */
 178         if (major(udev->devt) != 0 &&
 179             (strcmp(udev->action, "add") == 0 || strcmp(udev->action, "change") == 0)) {
 180                 struct udevice *udev_old;
 181
 182                 dbg("device node add '%s'\n", udev->dev->devpath);
 183
 184                 udev_rules_get_name(rules, udev);
 185                 if (udev->ignore_device) {
 186                         info("device event will be ignored\n");
 187                         goto exit;
 188                 }
 189                 if (udev->name[0] == '\0') {
 190                         info("device node creation supressed\n");
 191                         goto exit;
 192                 }
 193
 194                 /* read current database entry; cleanup, if it is known device */
 195                 udev_old = udev_device_init(NULL);
 196                 if (udev_old != NULL) {
 197                         udev_old->test_run = udev->test_run;
 198                         if (udev_db_get_device(udev_old, udev->dev->devpath) == 0) {
 199                                 info("device '%s' already in database, cleanup\n", udev->dev->devpath);
 200                                 udev_db_delete_device(udev_old);
 201                         } else {
 202                                 udev_device_cleanup(udev_old);
 203                                 udev_old = NULL;
 204                         }
 205                 }
 206
 207                 /* create node */
 208                 retval = udev_node_add(udev);
 209                 if (retval != 0)
 210                         goto exit;
 211
 212                 /* store in database */
 213                 udev_db_add_device(udev);
 214
 215                 /* create, replace, delete symlinks according to priority */
 216                 udev_node_update_symlinks(udev, udev_old);
 217
 218                 if (udev_old != NULL)
 219                         udev_device_cleanup(udev_old);
 220                 goto exit;
 221         }
 222
 223         /* add netif */
 224         if (strcmp(udev->dev->subsystem, "net") == 0 && strcmp(udev->action, "add") == 0) {
 225                 dbg("netif add '%s'\n", udev->dev->devpath);
 226                 udev_rules_get_name(rules, udev);
 227                 if (udev->ignore_device) {
 228                         info("device event will be ignored\n");
 229                         goto exit;
 230                 }
 231                 if (udev->name[0] == '\0') {
 232                         info("device renaming supressed\n");
 233                         goto exit;
 234                 }
 235
 236                 /* look if we want to change the name of the netif */
 237                 if (strcmp(udev->name, udev->dev->kernel) != 0) {
 238                         char devpath[PATH_MAX];
 239                         char *pos;
 240
 241                         retval = rename_netif(udev);
 242                         if (retval != 0)
 243                                 goto exit;
 244                         info("renamed netif to '%s'\n", udev->name);
 245
 246                         /* export old name */
 247                         setenv("INTERFACE_OLD", udev->dev->kernel, 1);
 248
 249                         /* now change the devpath, because the kernel device name has changed */
 250                         strlcpy(devpath, udev->dev->devpath, sizeof(devpath));
 251                         pos = strrchr(devpath, '/');
 252                         if (pos != NULL) {
 253                                 pos[1] = '\0';
 254                                 strlcat(devpath, udev->name, sizeof(devpath));
 255                                 sysfs_device_set_values(udev->dev, devpath, NULL, NULL);
 256                                 setenv("DEVPATH", udev->dev->devpath, 1);
 257                                 setenv("INTERFACE", udev->name, 1);
 258                                 info("changed devpath to '%s'\n", udev->dev->devpath);
 259                         }
 260                 }
 261                 goto exit;
 262         }
 263
 264         /* remove device node */
 265         if (major(udev->devt) != 0 && strcmp(udev->action, "remove") == 0) {
 266                 struct name_entry *name_loop;
 267
 268                 /* import database entry, and delete it */
 269                 if (udev_db_get_device(udev, udev->dev->devpath) == 0) {
 270                         udev_db_delete_device(udev);
 271                         /* restore stored persistent data */
 272                         list_for_each_entry(name_loop, &udev->env_list, node)
 273                                 putenv(name_loop->name);
 274                 } else {
 275                         dbg("'%s' not found in database, using kernel name '%s'\n",
 276                             udev->dev->devpath, udev->dev->kernel);
 277                         strlcpy(udev->name, udev->dev->kernel, sizeof(udev->name));
 278                 }
 279
 280                 udev_rules_get_run(rules, udev);
 281                 if (udev->ignore_device) {
 282                         info("device event will be ignored\n");
 283                         goto exit;
 284                 }
 285
 286                 if (udev->ignore_remove) {
 287                         info("ignore_remove for '%s'\n", udev->name);
 288                         goto exit;
 289                 }
 290                 /* remove the node */
 291                 retval = udev_node_remove(udev);
 292
 293                 /* delete or restore symlinks according to priority */
 294                 udev_node_update_symlinks(udev, NULL);
 295                 goto exit;
 296         }
 297
 298         /* default devices */
 299         udev_rules_get_run(rules, udev);
 300         if (udev->ignore_device)
 301                 info("device event will be ignored\n");
 302
 303 exit:
 304         return retval;
 305 }