net: Do delayed neigh confirmation.

[mirror_ubuntu-zesty-kernel.git] / net / ipv4 / tcp_input.c

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index b224eb8bce8b3c6644eb003fd1346dde30e77c83..ca0d0e7c977879023ba8c4151e3f33d0c55985a0 100644 (file)
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -740,13 +740,13 @@ void tcp_update_metrics(struct sock *sk)
        if (sysctl_tcp_nometrics_save)
                return;
 
-       dst_confirm(dst);
-
        if (dst && (dst->flags & DST_HOST)) {
                const struct inet_connection_sock *icsk = inet_csk(sk);
                int m;
                unsigned long rtt;
 
+               dst_confirm(dst);
+
                if (icsk->icsk_backoff || !tp->srtt) {
                        /* This session failed to estimate rtt. Why?
                         * Probably, no packets returned in time.
@@ -3869,9 +3869,11 @@ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag)
                        tcp_cong_avoid(sk, ack, prior_in_flight);
        }
 
-       if ((flag & FLAG_FORWARD_PROGRESS) || !(flag & FLAG_NOT_DUP))
-               dst_confirm(__sk_dst_get(sk));
-
+       if ((flag & FLAG_FORWARD_PROGRESS) || !(flag & FLAG_NOT_DUP)) {
+               struct dst_entry *dst = __sk_dst_get(sk);
+               if (dst)
+                       dst_confirm(dst);
+       }
        return 1;
 
 no_queue:
@@ -5518,6 +5520,18 @@ int tcp_rcv_established(struct sock *sk, struct sk_buff *skb,
        struct tcp_sock *tp = tcp_sk(sk);
        int res;
 
+       if (sk->sk_rx_dst) {
+               struct dst_entry *dst = sk->sk_rx_dst;
+               if (unlikely(dst->obsolete)) {
+                       if (dst->ops->check(dst, 0) == NULL) {
+                               dst_release(dst);
+                               sk->sk_rx_dst = NULL;
+                       }
+               }
+       }
+       if (unlikely(sk->sk_rx_dst == NULL))
+               sk->sk_rx_dst = dst_clone(skb_dst(skb));
+
        /*
         *      Header prediction.
         *      The code loosely follows the one in the famous
@@ -5729,8 +5743,10 @@ void tcp_finish_connect(struct sock *sk, struct sk_buff *skb)
 
        tcp_set_state(sk, TCP_ESTABLISHED);
 
-       if (skb != NULL)
+       if (skb != NULL) {
+               sk->sk_rx_dst = dst_clone(skb_dst(skb));
                security_inet_conn_established(sk, skb);
+       }
 
        /* Make sure socket is routed, for correct metrics.  */
        icsk->icsk_af_ops->rebuild_header(sk);
@@ -6126,9 +6142,14 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
 
                case TCP_FIN_WAIT1:
                        if (tp->snd_una == tp->write_seq) {
+                               struct dst_entry *dst;
+
                                tcp_set_state(sk, TCP_FIN_WAIT2);
                                sk->sk_shutdown |= SEND_SHUTDOWN;
-                               dst_confirm(__sk_dst_get(sk));
+
+                               dst = __sk_dst_get(sk);
+                               if (dst)
+                                       dst_confirm(dst);
 
                                if (!sock_flag(sk, SOCK_DEAD))
                                        /* Wake up lingering close() */