inet: includes a sock_common in request_sock

TCP listener refactoring, part 5 :

We want to be able to insert request sockets (SYN_RECV) into main
ehash table instead of the per listener hash table to allow RCU
lookups and remove listener lock contention.

This patch includes the needed struct sock_common in front
of struct request_sock

This means there is no more inet6_request_sock IPv6 specific
structure.

Following inet_request_sock fields were renamed as they became
macros to reference fields from struct sock_common.
Prefix ir_ was chosen to avoid name collisions.

loc_port   -> ir_loc_port
loc_addr   -> ir_loc_addr
rmt_addr   -> ir_rmt_addr
rmt_port   -> ir_rmt_port
iif        -> ir_iif

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/inet6_connection_sock.c b/net/ipv6/inet6_connection_sock.c
index b7400b4..1317c56 100644
--- a/net/ipv6/inet6_connection_sock.c
+++ b/net/ipv6/inet6_connection_sock.c
@@ -70,20 +70,20 @@
 				      struct flowi6 *fl6,
 				      const struct request_sock *req)
 {
-	struct inet6_request_sock *treq = inet6_rsk(req);
+	struct inet_request_sock *ireq = inet_rsk(req);
 	struct ipv6_pinfo *np = inet6_sk(sk);
 	struct in6_addr *final_p, final;
 	struct dst_entry *dst;
 
 	memset(fl6, 0, sizeof(*fl6));
 	fl6->flowi6_proto = IPPROTO_TCP;
-	fl6->daddr = treq->rmt_addr;
+	fl6->daddr = ireq->ir_v6_rmt_addr;
 	final_p = fl6_update_dst(fl6, np->opt, &final);
-	fl6->saddr = treq->loc_addr;
-	fl6->flowi6_oif = treq->iif;
+	fl6->saddr = ireq->ir_v6_loc_addr;
+	fl6->flowi6_oif = ireq->ir_iif;
 	fl6->flowi6_mark = sk->sk_mark;
-	fl6->fl6_dport = inet_rsk(req)->rmt_port;
-	fl6->fl6_sport = inet_rsk(req)->loc_port;
+	fl6->fl6_dport = ireq->ir_rmt_port;
+	fl6->fl6_sport = ireq->ir_loc_port;
 	security_req_classify_flow(req, flowi6_to_flowi(fl6));
 
 	dst = ip6_dst_lookup_flow(sk, fl6, final_p, false);
@@ -129,13 +129,13 @@
 						     lopt->nr_table_entries)];
 	     (req = *prev) != NULL;
 	     prev = &req->dl_next) {
-		const struct inet6_request_sock *treq = inet6_rsk(req);
+		const struct inet_request_sock *ireq = inet_rsk(req);
 
-		if (inet_rsk(req)->rmt_port == rport &&
+		if (ireq->ir_rmt_port == rport &&
 		    req->rsk_ops->family == AF_INET6 &&
-		    ipv6_addr_equal(&treq->rmt_addr, raddr) &&
-		    ipv6_addr_equal(&treq->loc_addr, laddr) &&
-		    (!treq->iif || treq->iif == iif)) {
+		    ipv6_addr_equal(&ireq->ir_v6_rmt_addr, raddr) &&
+		    ipv6_addr_equal(&ireq->ir_v6_loc_addr, laddr) &&
+		    (!ireq->ir_iif || ireq->ir_iif == iif)) {
 			WARN_ON(req->sk != NULL);
 			*prevp = prev;
 			return req;
@@ -153,8 +153,8 @@
 {
 	struct inet_connection_sock *icsk = inet_csk(sk);
 	struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
-	const u32 h = inet6_synq_hash(&inet6_rsk(req)->rmt_addr,
-				      inet_rsk(req)->rmt_port,
+	const u32 h = inet6_synq_hash(&inet_rsk(req)->ir_v6_rmt_addr,
+				      inet_rsk(req)->ir_rmt_port,
 				      lopt->hash_rnd, lopt->nr_table_entries);
 
 	reqsk_queue_hash_req(&icsk->icsk_accept_queue, h, req, timeout);