[PATCH 13/46] Driver core: notify userspace of network device renames

Greg Kroah-Hartman
2007-04-27T19:14:22Z

From: Jean Tourrilhes <jt@hpl.hp.com>

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 | 30 ++++++++++++++++++++++++++++++
net/core/net-sysfs.c | 11 +++++++++++
2 files changed, 41 insertions(+), 0 deletions(-)

diff --git a/lib/kobject.c b/lib/kobject.c
index bbbfab4..db1d237 100644
--- a/lib/kobject.c
+++ b/lib/kobject.c
@@ -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;
diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index 221a64a..e441ec7 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -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;
}
--
1.5.1.2