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>

4 files changed, 14 insertions, 33 deletions

diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h
index 35f6c1b562c4..a80a63cfb70c 100644
--- a/include/linux/ipv6.h
+++ b/include/linux/ipv6.h
@@ -115,16 +115,8 @@ static inline int inet6_iif(const struct sk_buff *skb)
 	return IP6CB(skb)->iif;
 }
 
-struct inet6_request_sock {
-	struct in6_addr		loc_addr;
-	struct in6_addr		rmt_addr;
-	struct sk_buff		*pktopts;
-	int			iif;
-};
-
 struct tcp6_request_sock {
 	struct tcp_request_sock	  tcp6rsk_tcp;
-	struct inet6_request_sock tcp6rsk_inet6;
 };
 
 struct ipv6_mc_socklist;
@@ -264,26 +256,12 @@ static inline struct ipv6_pinfo * inet6_sk(const struct sock *__sk)
 	return inet_sk(__sk)->pinet6;
 }
 
-static inline struct inet6_request_sock *
-			inet6_rsk(const struct request_sock *rsk)
-{
-	return (struct inet6_request_sock *)(((u8 *)rsk) +
-					     inet_rsk(rsk)->inet6_rsk_offset);
-}
-
-static inline u32 inet6_rsk_offset(struct request_sock *rsk)
-{
-	return rsk->rsk_ops->obj_size - sizeof(struct inet6_request_sock);
-}
-
 static inline struct request_sock *inet6_reqsk_alloc(struct request_sock_ops *ops)
 {
 	struct request_sock *req = reqsk_alloc(ops);
 
-	if (req != NULL) {
-		inet_rsk(req)->inet6_rsk_offset = inet6_rsk_offset(req);
-		inet6_rsk(req)->pktopts = NULL;
-	}
+	if (req)
+		inet_rsk(req)->pktopts = NULL;
 
 	return req;
 }
diff --git a/include/net/inet_sock.h b/include/net/inet_sock.h
index 6d9a7e6eb5a4..f91204442efa 100644
--- a/include/net/inet_sock.h
+++ b/include/net/inet_sock.h
@@ -70,13 +70,14 @@ struct ip_options_data {
 
 struct inet_request_sock {
 	struct request_sock	req;
-#if IS_ENABLED(CONFIG_IPV6)
-	u16			inet6_rsk_offset;
-#endif
-	__be16			loc_port;
-	__be32			loc_addr;
-	__be32			rmt_addr;
-	__be16			rmt_port;
+#define ir_loc_addr		req.__req_common.skc_rcv_saddr
+#define ir_rmt_addr		req.__req_common.skc_daddr
+#define ir_loc_port		req.__req_common.skc_num
+#define ir_rmt_port		req.__req_common.skc_dport
+#define ir_v6_rmt_addr		req.__req_common.skc_v6_daddr
+#define ir_v6_loc_addr		req.__req_common.skc_v6_rcv_saddr
+#define ir_iif			req.__req_common.skc_bound_dev_if
+
 	kmemcheck_bitfield_begin(flags);
 	u16			snd_wscale : 4,
 				rcv_wscale : 4,
@@ -88,6 +89,7 @@ struct inet_request_sock {
 				no_srccheck: 1;
 	kmemcheck_bitfield_end(flags);
 	struct ip_options_rcu	*opt;
+	struct sk_buff		*pktopts;
 };
 
 static inline struct inet_request_sock *inet_rsk(const struct request_sock *sk)
diff --git a/include/net/request_sock.h b/include/net/request_sock.h
index 65c3e5164a5c..7f830ff67f08 100644
--- a/include/net/request_sock.h
+++ b/include/net/request_sock.h
@@ -48,6 +48,7 @@ int inet_rtx_syn_ack(struct sock *parent, struct request_sock *req);
 /* struct request_sock - mini sock to represent a connection request
  */
 struct request_sock {
+	struct sock_common		__req_common;
 	struct request_sock		*dl_next;
 	u16				mss;
 	u8				num_retrans; /* number of retransmits */
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 39bbfa1602b2..24a06161d174 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -1109,8 +1109,8 @@ static inline void tcp_openreq_init(struct request_sock *req,
 	ireq->wscale_ok = rx_opt->wscale_ok;
 	ireq->acked = 0;
 	ireq->ecn_ok = 0;
-	ireq->rmt_port = tcp_hdr(skb)->source;
-	ireq->loc_port = tcp_hdr(skb)->dest;
+	ireq->ir_rmt_port = tcp_hdr(skb)->source;
+	ireq->ir_loc_port = tcp_hdr(skb)->dest;
 }
 
 void tcp_enter_memory_pressure(struct sock *sk);