[INET]: Let inet_diag and friends autoload

By adding module aliases to inet_diag, tcp_diag and dccp_diag, we let
them load automatically as needed. This makes tools like "ss" run
faster.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c
index 7eb83eb..dc429b6 100644
--- a/net/ipv4/inet_diag.c
+++ b/net/ipv4/inet_diag.c
@@ -815,6 +815,12 @@
 	    nlmsg_len(nlh) < hdrlen)
 		return -EINVAL;
 
+#ifdef CONFIG_KMOD
+	if (inet_diag_table[nlh->nlmsg_type] == NULL)
+		request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
+			       NETLINK_INET_DIAG, nlh->nlmsg_type);
+#endif
+
 	if (inet_diag_table[nlh->nlmsg_type] == NULL)
 		return -ENOENT;
 
@@ -914,3 +920,4 @@
 module_init(inet_diag_init);
 module_exit(inet_diag_exit);
 MODULE_LICENSE("GPL");
+MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_INET_DIAG);