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