sctp: process sk_reuseport in sctp_get_port_local

When socks' sk_reuseport is set, the same port and address are allowed
to be bound into these socks who have the same uid.

Note that the difference from sk_reuse is that it allows multiple socks
to listen on the same port and address.

Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index 15d017f..af9d494 100644
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -96,7 +96,9 @@ struct sctp_stream;
 
 struct sctp_bind_bucket {
 	unsigned short	port;
-	unsigned short	fastreuse;
+	signed char	fastreuse;
+	signed char	fastreuseport;
+	kuid_t		fastuid;
 	struct hlist_node	node;
 	struct hlist_head	owner;
 	struct net	*net;