+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'", 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", 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", 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", 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",
+ ifr.ifr_name, ifr.ifr_newname, strerror(errno));
+ break;
+ }
+ dbg("wait for netif '%s' to become free, loop=%i", udev->name, (30 * 20) - loop);
+ usleep(1000 * 1000 / 20);
+ }
+ }
+
+exit:
+ close(sk);
+ return retval;
+}
+