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/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index 56e82a4..2ffd931 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -412,8 +412,8 @@
 			   RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
 			   sk->sk_protocol,
 			   flags,
-			   (opt && opt->opt.srr) ? opt->opt.faddr : ireq->rmt_addr,
-			   ireq->loc_addr, ireq->rmt_port, inet_sk(sk)->inet_sport);
+			   (opt && opt->opt.srr) ? opt->opt.faddr : ireq->ir_rmt_addr,
+			   ireq->ir_loc_addr, ireq->ir_rmt_port, inet_sk(sk)->inet_sport);
 	security_req_classify_flow(req, flowi4_to_flowi(fl4));
 	rt = ip_route_output_flow(net, fl4, sk);
 	if (IS_ERR(rt))
@@ -448,8 +448,8 @@
 	flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark,
 			   RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
 			   sk->sk_protocol, inet_sk_flowi_flags(sk),
-			   (opt && opt->opt.srr) ? opt->opt.faddr : ireq->rmt_addr,
-			   ireq->loc_addr, ireq->rmt_port, inet_sk(sk)->inet_sport);
+			   (opt && opt->opt.srr) ? opt->opt.faddr : ireq->ir_rmt_addr,
+			   ireq->ir_loc_addr, ireq->ir_rmt_port, inet_sk(sk)->inet_sport);
 	security_req_classify_flow(req, flowi4_to_flowi(fl4));
 	rt = ip_route_output_flow(net, fl4, sk);
 	if (IS_ERR(rt))
@@ -495,9 +495,9 @@
 	     prev = &req->dl_next) {
 		const struct inet_request_sock *ireq = inet_rsk(req);
 
-		if (ireq->rmt_port == rport &&
-		    ireq->rmt_addr == raddr &&
-		    ireq->loc_addr == laddr &&
+		if (ireq->ir_rmt_port == rport &&
+		    ireq->ir_rmt_addr == raddr &&
+		    ireq->ir_loc_addr == laddr &&
 		    AF_INET_FAMILY(req->rsk_ops->family)) {
 			WARN_ON(req->sk);
 			*prevp = prev;
@@ -514,7 +514,8 @@
 {
 	struct inet_connection_sock *icsk = inet_csk(sk);
 	struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
-	const u32 h = inet_synq_hash(inet_rsk(req)->rmt_addr, inet_rsk(req)->rmt_port,
+	const u32 h = inet_synq_hash(inet_rsk(req)->ir_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);
@@ -674,9 +675,9 @@
 		newsk->sk_state = TCP_SYN_RECV;
 		newicsk->icsk_bind_hash = NULL;
 
-		inet_sk(newsk)->inet_dport = inet_rsk(req)->rmt_port;
-		inet_sk(newsk)->inet_num = ntohs(inet_rsk(req)->loc_port);
-		inet_sk(newsk)->inet_sport = inet_rsk(req)->loc_port;
+		inet_sk(newsk)->inet_dport = inet_rsk(req)->ir_rmt_port;
+		inet_sk(newsk)->inet_num = ntohs(inet_rsk(req)->ir_loc_port);
+		inet_sk(newsk)->inet_sport = inet_rsk(req)->ir_loc_port;
 		newsk->sk_write_space = sk_stream_write_space;
 
 		newicsk->icsk_retransmits = 0;