From: Harald Hoyer <harald@redhat.com>
Date: Tue, 10 Aug 2010 14:41:24 +0000 (+0200)
Subject: udev-event.c: rename interface to <src>-<dest>, if <dest> taken
X-Git-Tag: 174~382
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=commitdiff_plain;h=09c03103028011935044bbade29a602925898f27;p=elogind.git

udev-event.c: rename interface to <src>-<dest>, if <dest> taken

e.g. if eth0 should be eth3 and eth3 is waiting to be renamed,
eth0 was renamed to eth0_rename. The kernel would take eth0 as the name
for a new interface and this new eth0 could also become eth0_rename, if
the target name is also taken. To prevent this name clash, the
interfaces are now renamed to <src>-<dest> and the rename is logged.
---

diff --git a/udev/udev-event.c b/udev/udev-event.c
index 7591d5e31..7785ad892 100644
--- a/udev/udev-event.c
+++ b/udev/udev-event.c
@@ -465,6 +465,7 @@ static int rename_netif(struct udev_event *event)
 	int sk;
 	struct ifreq ifr;
 	int err;
+	char *newdup;
 
 	info(event->udev, "changing net interface name from '%s' to '%s'\n",
 	     udev_device_get_sysname(dev), event->name);
@@ -492,13 +493,16 @@ static int rename_netif(struct udev_event *event)
 		}
 
 		/* free our own name, another process may wait for us */
-		util_strscpyl(ifr.ifr_newname, IFNAMSIZ, udev_device_get_sysname(dev), "_rename", NULL);
+		newdup = strdup(ifr.ifr_newname);
+		util_strscpyl(ifr.ifr_newname, IFNAMSIZ, udev_device_get_sysname(dev), "-", newdup, NULL);
+		free(newdup);
 		err = ioctl(sk, SIOCSIFNAME, &ifr);
 		if (err != 0) {
 			err(event->udev, "error changing netif name %s to %s: %m\n",
 			    ifr.ifr_name, ifr.ifr_newname);
 			goto exit;
 		}
+		rename_netif_kernel_log(ifr);
 
 		/* wait 90 seconds for our target to become available */
 		util_strscpy(ifr.ifr_name, IFNAMSIZ, ifr.ifr_newname);