[SOCK]: Introduce sk_setup_caps

From tcp_v4_setup_caps, that always is preceded by a call to
__sk_dst_set, so coalesce this sequence into sk_setup_caps, removing
one call to a TCP function in the IP layer.
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/sock.h

@@ -1025,6 +1025,16 @@ sk_dst_check(struct sock *sk, u32 cookie)
 	return dst;
 }
 
+static inline void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
+{
+	__sk_dst_set(sk, dst);
+	sk->sk_route_caps = dst->dev->features;
+	if (sk->sk_route_caps & NETIF_F_TSO) {
+		if (sock_flag(sk, SOCK_NO_LARGESEND) || dst->header_len)
+			sk->sk_route_caps &= ~NETIF_F_TSO;
+	}
+}
+
 static inline void sk_charge_skb(struct sock *sk, struct sk_buff *skb)
 {
 	sk->sk_wmem_queued   += skb->truesize;

include/net/tcp.h

@@ -1658,15 +1658,6 @@ static inline int tcp_paws_check(const struct tcp_options_received *rx_opt, int
 	return 1;
 }
 
-static inline void tcp_v4_setup_caps(struct sock *sk, struct dst_entry *dst)
-{
-	sk->sk_route_caps = dst->dev->features;
-	if (sk->sk_route_caps & NETIF_F_TSO) {
-		if (sock_flag(sk, SOCK_NO_LARGESEND) || dst->header_len)
-			sk->sk_route_caps &= ~NETIF_F_TSO;
-	}
-}
-
 #define TCP_CHECK_TIMER(sk) do { } while (0)
 
 static inline int tcp_use_frto(const struct sock *sk)

net/ipv4/ip_output.c

@@ -69,13 +69,10 @@
 #include <net/ip.h>
 #include <net/protocol.h>
 #include <net/route.h>
-#include <net/tcp.h>
-#include <net/udp.h>
 #include <linux/skbuff.h>
 #include <net/sock.h>
 #include <net/arp.h>
 #include <net/icmp.h>
-#include <net/raw.h>
 #include <net/checksum.h>
 #include <net/inetpeer.h>
 #include <net/checksum.h>
@@ -84,6 +81,7 @@
 #include <linux/netfilter_bridge.h>
 #include <linux/mroute.h>
 #include <linux/netlink.h>
+#include <linux/tcp.h>
 
 /*
  *      Shall we try to damage output packets if routing dev changes?
@@ -329,8 +327,7 @@ int ip_queue_xmit(struct sk_buff *skb, int ipfragok)
 			if (ip_route_output_flow(&rt, &fl, sk, 0))
 				goto no_route;
 		}
-		__sk_dst_set(sk, &rt->u.dst);
-		tcp_v4_setup_caps(sk, &rt->u.dst);
+		sk_setup_caps(sk, &rt->u.dst);
 	}
 	skb->dst = dst_clone(&rt->u.dst);
 

net/ipv4/tcp_ipv4.c

@@ -837,8 +837,7 @@ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 		goto failure;
 
 	/* OK, now commit destination to socket.  */
-	__sk_dst_set(sk, &rt->u.dst);
-	tcp_v4_setup_caps(sk, &rt->u.dst);
+	sk_setup_caps(sk, &rt->u.dst);
 
 	if (!tp->write_seq)
 		tp->write_seq = secure_tcp_sequence_number(inet->saddr,
@@ -1553,8 +1552,7 @@ struct sock *tcp_v4_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
 	if (!newsk)
 		goto exit;
 
-	newsk->sk_dst_cache = dst;
-	tcp_v4_setup_caps(newsk, dst);
+	sk_setup_caps(newsk, dst);
 
 	newtp		      = tcp_sk(newsk);
 	newinet		      = inet_sk(newsk);
@@ -1855,8 +1853,7 @@ static int tcp_v4_reselect_saddr(struct sock *sk)
 	if (err)
 		return err;
 
-	__sk_dst_set(sk, &rt->u.dst);
-	tcp_v4_setup_caps(sk, &rt->u.dst);
+	sk_setup_caps(sk, &rt->u.dst);
 
 	new_saddr = rt->rt_src;
 
@@ -1914,8 +1911,7 @@ int tcp_v4_rebuild_header(struct sock *sk)
 		err = ip_route_output_flow(&rt, &fl, sk, 0);
 	}
 	if (!err) {
-		__sk_dst_set(sk, &rt->u.dst);
-		tcp_v4_setup_caps(sk, &rt->u.dst);
+		sk_setup_caps(sk, &rt->u.dst);
 		return 0;
 	}
 

net/ipv4/tcp_minisocks.c

@@ -711,6 +711,7 @@ struct sock *tcp_create_openreq_child(struct sock *sk, struct request_sock *req,
 		bh_lock_sock(newsk);
 
 		rwlock_init(&newsk->sk_dst_lock);
+		newsk->sk_dst_cache = NULL;
 		atomic_set(&newsk->sk_rmem_alloc, 0);
 		skb_queue_head_init(&newsk->sk_receive_queue);
 		atomic_set(&newsk->sk_wmem_alloc, 0);