rtnetlink: rtnl_link_register() sanity test
Before adding a struct rtnl_link_ops into link_ops list, check it doesnt
clash with a prior one.
Based on a previous patch from Alexander Smirnov
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 9083e82..dbf2dda 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -273,6 +273,17 @@
static LIST_HEAD(link_ops);
+static const struct rtnl_link_ops *rtnl_link_ops_get(const char *kind)
+{
+ const struct rtnl_link_ops *ops;
+
+ list_for_each_entry(ops, &link_ops, list) {
+ if (!strcmp(ops->kind, kind))
+ return ops;
+ }
+ return NULL;
+}
+
/**
* __rtnl_link_register - Register rtnl_link_ops with rtnetlink.
* @ops: struct rtnl_link_ops * to register
@@ -285,6 +296,9 @@
*/
int __rtnl_link_register(struct rtnl_link_ops *ops)
{
+ if (rtnl_link_ops_get(ops->kind))
+ return -EEXIST;
+
if (!ops->dellink)
ops->dellink = unregister_netdevice_queue;
@@ -351,17 +365,6 @@
}
EXPORT_SYMBOL_GPL(rtnl_link_unregister);
-static const struct rtnl_link_ops *rtnl_link_ops_get(const char *kind)
-{
- const struct rtnl_link_ops *ops;
-
- list_for_each_entry(ops, &link_ops, list) {
- if (!strcmp(ops->kind, kind))
- return ops;
- }
- return NULL;
-}
-
static size_t rtnl_link_get_size(const struct net_device *dev)
{
const struct rtnl_link_ops *ops = dev->rtnl_link_ops;