netlink: Make NETLINK_USERSOCK work again.

Once we started enforcing the a nl_table[] entry exist for
a protocol, NETLINK_USERSOCK stopped working.  Add a dummy
table entry so that it works again.

Reported-by: Thomas Voegtle <tv@lio96.de>
Tested-by: Thomas Voegtle <tv@lio96.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 980fe4a..cd96ed3 100644 (file)
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -2102,6 +2102,26 @@ static void __net_exit netlink_net_exit(struct net *net)
 #endif
 }
 
+static void __init netlink_add_usersock_entry(void)
+{
+       unsigned long *listeners;
+       int groups = 32;
+
+       listeners = kzalloc(NLGRPSZ(groups) + sizeof(struct listeners_rcu_head),
+                           GFP_KERNEL);
+       if (!listeners)
+               panic("netlink_add_usersock_entry: Cannot allocate listneres\n");
+
+       netlink_table_grab();
+
+       nl_table[NETLINK_USERSOCK].groups = groups;
+       nl_table[NETLINK_USERSOCK].listeners = listeners;
+       nl_table[NETLINK_USERSOCK].module = THIS_MODULE;
+       nl_table[NETLINK_USERSOCK].registered = 1;
+
+       netlink_table_ungrab();
+}
+
 static struct pernet_operations __net_initdata netlink_net_ops = {
        .init = netlink_net_init,
        .exit = netlink_net_exit,
@@ -2150,6 +2170,8 @@ static int __init netlink_proto_init(void)
                hash->rehash_time = jiffies;
        }
 
+       netlink_add_usersock_entry();
+
        sock_register(&netlink_family_ops);
        register_pernet_subsys(&netlink_net_ops);
        /* The netlink device handler may be needed early. */