Merge branch 'l2tp-module-autoloading'

Stephen Hemminger says:

====================
l2tp: module autoloading

With L2TP it was necessary to manually load modules
which is a nuisance and not required with other tunneling
protocols. This set of patches adds the aliases and module
load hook to get rid of the necessity of modprobing.
====================
Acked-By: NJames Chapman <jchapman@katalix.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Documentation/networking/l2tp.txt

@@ -213,15 +213,12 @@ To create an L2TPv3 ethernet pseudowire between local host 192.168.1.1
 and peer 192.168.1.2, using IP addresses 10.5.1.1 and 10.5.1.2 for the
 tunnel endpoints:-
 
-# modprobe l2tp_eth
-# modprobe l2tp_netlink
-
 # ip l2tp add tunnel tunnel_id 1 peer_tunnel_id 1 udp_sport 5000 \
   udp_dport 5000 encap udp local 192.168.1.1 remote 192.168.1.2
 # ip l2tp add session tunnel_id 1 session_id 1 peer_session_id 1
-# ifconfig -a
+# ip -s -d show dev l2tpeth0
 # ip addr add 10.5.1.2/32 peer 10.5.1.1/32 dev l2tpeth0
-# ifconfig l2tpeth0 up
+# ip li set dev l2tpeth0 up
 
 Choose IP addresses to be the address of a local IP interface and that
 of the remote system. The IP addresses of the l2tpeth0 interface can be

net/l2tp/l2tp_core.h

@@ -321,4 +321,7 @@ do {									\
 #define l2tp_dbg(ptr, type, fmt, ...)					\
 	l2tp_printk(ptr, type, pr_debug, fmt, ##__VA_ARGS__)
 
+#define MODULE_ALIAS_L2TP_PWTYPE(type) \
+	MODULE_ALIAS("net-l2tp-type-" __stringify(type))
+
 #endif /* _L2TP_CORE_H_ */

net/l2tp/l2tp_eth.c

@@ -358,3 +358,4 @@ MODULE_LICENSE("GPL");
 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
 MODULE_DESCRIPTION("L2TP ethernet pseudowire driver");
 MODULE_VERSION("1.0");
+MODULE_ALIAS_L2TP_PWTYPE(5);

net/l2tp/l2tp_ip.c

@@ -655,3 +655,4 @@ MODULE_VERSION("1.0");
  * enums
  */
 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET, 2, IPPROTO_L2TP);
+MODULE_ALIAS_NET_PF_PROTO(PF_INET, IPPROTO_L2TP);

net/l2tp/l2tp_ip6.c

@@ -801,3 +801,4 @@ MODULE_VERSION("1.0");
  * enums
  */
 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 2, IPPROTO_L2TP);
+MODULE_ALIAS_NET_PF_PROTO(PF_INET6, IPPROTO_L2TP);

net/l2tp/l2tp_netlink.c

@@ -576,6 +576,13 @@ static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *inf
 	if (info->attrs[L2TP_ATTR_MRU])
 		cfg.mru = nla_get_u16(info->attrs[L2TP_ATTR_MRU]);
 
+#ifdef CONFIG_MODULES
+	if (l2tp_nl_cmd_ops[cfg.pw_type] == NULL) {
+		genl_unlock();
+		request_module("net-l2tp-type-%u", cfg.pw_type);
+		genl_lock();
+	}
+#endif
 	if ((l2tp_nl_cmd_ops[cfg.pw_type] == NULL) ||
 	    (l2tp_nl_cmd_ops[cfg.pw_type]->session_create == NULL)) {
 		ret = -EPROTONOSUPPORT;

net/l2tp/l2tp_ppp.c

@@ -1863,3 +1863,4 @@ MODULE_DESCRIPTION("PPP over L2TP over UDP");
 MODULE_LICENSE("GPL");
 MODULE_VERSION(PPPOL2TP_DRV_VERSION);
 MODULE_ALIAS("pppox-proto-" __stringify(PX_PROTO_OL2TP));
+MODULE_ALIAS_L2TP_PWTYPE(11);