udev_device_event.c revision 44aff4cd6d74d230e4a97f8d59f780472b7cad6e
/*
* Copyright (C) 2004-2006 Kay Sievers <kay.sievers@vrfy.org>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation version 2 of the License.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
*/
#include <stdlib.h>
#include <stdio.h>
#include <stddef.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <ctype.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <net/if.h>
#include <linux/sockios.h>
#include "udev.h"
#include "udev_rules.h"
static void kernel_log(struct ifreq ifr)
{
int klog;
FILE *f;
klog = open("/dev/kmsg", O_WRONLY);
if (klog < 0)
return;
f = fdopen(klog, "w");
if (f == NULL) {
close(klog);
return;
}
fprintf(f, "<6>udev: renamed network interface %s to %s\n",
ifr.ifr_name, ifr.ifr_newname);
fclose(f);
}
static int rename_netif(struct udevice *udev)
{
int sk;
struct ifreq ifr;
int retval;
info("changing net interface name from '%s' to '%s'\n", udev->dev->kernel, udev->name);
if (udev->test_run)
return 0;
sk = socket(PF_INET, SOCK_DGRAM, 0);
if (sk < 0) {
err("error opening socket: %s\n", strerror(errno));
return -1;
}
memset(&ifr, 0x00, sizeof(struct ifreq));
strlcpy(ifr.ifr_name, udev->dev->kernel, IFNAMSIZ);
strlcpy(ifr.ifr_newname, udev->name, IFNAMSIZ);
retval = ioctl(sk, SIOCSIFNAME, &ifr);
if (retval == 0)
kernel_log(ifr);
else {
int loop;
/* see if the destination interface name already exists */
if (errno != EEXIST) {
err("error changing netif name %s to %s: %s\n", ifr.ifr_name, ifr.ifr_newname, strerror(errno));
goto exit;
}
/* free our own name, another process may wait for us */
strlcpy(ifr.ifr_newname, udev->dev->kernel, IFNAMSIZ);
strlcat(ifr.ifr_newname, "_rename", IFNAMSIZ);
retval = ioctl(sk, SIOCSIFNAME, &ifr);
if (retval != 0) {
err("error changing netif name %s to %s: %s\n", ifr.ifr_name, ifr.ifr_newname, strerror(errno));
goto exit;
}
/* wait 30 seconds for our target to become available */
strlcpy(ifr.ifr_name, ifr.ifr_newname, IFNAMSIZ);
strlcpy(ifr.ifr_newname, udev->name, IFNAMSIZ);
loop = 30 * 20;
while (loop--) {
retval = ioctl(sk, SIOCSIFNAME, &ifr);
if (retval == 0) {
kernel_log(ifr);
break;
}
if (errno != EEXIST) {
err("error changing net interface name %s to %s: %s\n",
ifr.ifr_name, ifr.ifr_newname, strerror(errno));
break;
}
dbg("wait for netif '%s' to become free, loop=%i\n", udev->name, (30 * 20) - loop);
usleep(1000 * 1000 / 20);
}
}
exit:
close(sk);
return retval;
}
int udev_device_event(struct udev_rules *rules, struct udevice *udev)
{
int retval = 0;
if (udev->devpath_old != NULL)
if (udev_db_rename(udev->devpath_old, udev->dev->devpath) == 0)
info("moved database from '%s' to '%s'\n", udev->devpath_old, udev->dev->devpath);
/* add device node */
if (major(udev->devt) != 0 &&
(strcmp(udev->action, "add") == 0 || strcmp(udev->action, "change") == 0)) {
struct udevice *udev_old;
dbg("device node add '%s'\n", udev->dev->devpath);
udev_rules_get_name(rules, udev);
if (udev->ignore_device) {
info("device event will be ignored\n");
goto exit;
}
if (udev->name[0] == '\0') {
info("device node creation supressed\n");
goto exit;
}
/* read current database entry; cleanup, if it is known device */
udev_old = udev_device_init();
if (udev_old != NULL) {
udev_old->test_run = udev->test_run;
if (udev_db_get_device(udev_old, udev->dev->devpath) == 0) {
info("device '%s' already in database, cleanup\n", udev->dev->devpath);
udev_db_delete_device(udev_old);
} else {
udev_device_cleanup(udev_old);
udev_old = NULL;
}
}
/* create node */
retval = udev_node_add(udev);
if (retval != 0)
goto exit;
/* store in database */
udev_db_add_device(udev);
/* create, replace, delete symlinks according to priority */
udev_node_update_symlinks(udev, udev_old);
if (udev_old != NULL)
udev_device_cleanup(udev_old);
goto exit;
}
/* add netif */
if (strcmp(udev->dev->subsystem, "net") == 0 && strcmp(udev->action, "add") == 0) {
dbg("netif add '%s'\n", udev->dev->devpath);
udev_rules_get_name(rules, udev);
if (udev->ignore_device) {
info("device event will be ignored\n");
goto exit;
}
if (udev->name[0] == '\0') {
info("device renaming supressed\n");
goto exit;
}
/* look if we want to change the name of the netif */
if (strcmp(udev->name, udev->dev->kernel) != 0) {
char devpath[PATH_MAX];
char *pos;
retval = rename_netif(udev);
if (retval != 0)
goto exit;
info("renamed netif to '%s'\n", udev->name);
/* export old name */
setenv("INTERFACE_OLD", udev->dev->kernel, 1);
/* now change the devpath, because the kernel device name has changed */
strlcpy(devpath, udev->dev->devpath, sizeof(devpath));
pos = strrchr(devpath, '/');
if (pos != NULL) {
pos[1] = '\0';
strlcat(devpath, udev->name, sizeof(devpath));
sysfs_device_set_values(udev->dev, devpath, NULL, NULL);
setenv("DEVPATH", udev->dev->devpath, 1);
setenv("INTERFACE", udev->name, 1);
info("changed devpath to '%s'\n", udev->dev->devpath);
}
}
goto exit;
}
/* remove device node */
if (major(udev->devt) != 0 && strcmp(udev->action, "remove") == 0) {
struct name_entry *name_loop;
/* import database entry, and delete it */
if (udev_db_get_device(udev, udev->dev->devpath) == 0) {
udev_db_delete_device(udev);
/* restore stored persistent data */
list_for_each_entry(name_loop, &udev->env_list, node)
putenv(name_loop->name);
} else {
dbg("'%s' not found in database, using kernel name '%s'\n",
udev->dev->devpath, udev->dev->kernel);
strlcpy(udev->name, udev->dev->kernel, sizeof(udev->name));
}
udev_rules_get_run(rules, udev);
if (udev->ignore_device) {
info("device event will be ignored\n");
goto exit;
}
if (udev->ignore_remove) {
info("ignore_remove for '%s'\n", udev->name);
goto exit;
}
/* remove the node */
retval = udev_node_remove(udev);
/* delete or restore symlinks according to priority */
udev_node_update_symlinks(udev, NULL);
goto exit;
}
/* default devices */
udev_rules_get_run(rules, udev);
if (udev->ignore_device)
info("device event will be ignored\n");
exit:
return retval;
}