Driver core: notify userspace of network device renames
Jean Tourrilhes [Wed, 7 Mar 2007 18:49:30 +0000 (10:49 -0800)]
Provide rename event for when we rename network devices.

Signed-off-by: Jean Tourrilhes <jt@hpl.hp.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

lib/kobject.c
net/core/net-sysfs.c

index bbbfab4..db1d237 100644 (file)
@@ -311,13 +311,43 @@ EXPORT_SYMBOL(kobject_set_name);
 int kobject_rename(struct kobject * kobj, const char *new_name)
 {
        int error = 0;
+       const char *devpath = NULL;
+       char *devpath_string = NULL;
+       char *envp[2];
 
        kobj = kobject_get(kobj);
        if (!kobj)
                return -EINVAL;
        if (!kobj->parent)
                return -EINVAL;
+
+       devpath = kobject_get_path(kobj, GFP_KERNEL);
+       if (!devpath) {
+               error = -ENOMEM;
+               goto out;
+       }
+       devpath_string = kmalloc(strlen(devpath) + 15, GFP_KERNEL);
+       if (!devpath_string) {
+               error = -ENOMEM;
+               goto out;
+       }
+       sprintf(devpath_string, "DEVPATH_OLD=%s", devpath);
+       envp[0] = devpath_string;
+       envp[1] = NULL;
+       /* Note : if we want to send the new name alone, not the full path,
+        * we could probably use kobject_name(kobj); */
+
        error = sysfs_rename_dir(kobj, kobj->parent->dentry, new_name);
+
+       /* This function is mostly/only used for network interface.
+        * Some hotplug package track interfaces by their name and
+        * therefore want to know when the name is changed by the user. */
+       if (!error)
+               kobject_uevent_env(kobj, KOBJ_MOVE, envp);
+
+out:
+       kfree(devpath_string);
+       kfree(devpath);
        kobject_put(kobj);
 
        return error;
index 221a64a..e441ec7 100644 (file)
@@ -424,6 +424,17 @@ static int netdev_uevent(struct device *d, char **envp,
        if ((size <= 0) || (i >= num_envp))
                return -ENOMEM;
 
+       /* pass ifindex to uevent.
+        * ifindex is useful as it won't change (interface name may change)
+        * and is what RtNetlink uses natively. */
+       envp[i++] = buf;
+       n = snprintf(buf, size, "IFINDEX=%d", dev->ifindex) + 1;
+       buf += n;
+       size -= n;
+
+       if ((size <= 0) || (i >= num_envp))
+               return -ENOMEM;
+
        envp[i] = NULL;
        return 0;
 }