tcp: make tcp_rcv_state_process() drop monitor friendly

tcp_rcv_state_process() incorrectly drops packets
instead of consuming it, making drop monitor very noisy,
if not unusable.

Calling tcp_time_wait() or tcp_done() is part
of standard behavior, packets triggering these actions
were not dropped.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 9a1cb3f48c3fb26beac4283001d38828ca15a4d9..f95a8368981d319400d0f46b81ced954d941f718 100644 (file)
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -6580,7 +6580,7 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb)
                        inet_csk_reset_keepalive_timer(sk, tmo);
                } else {
                        tcp_time_wait(sk, TCP_FIN_WAIT2, tmo);
-                       goto discard;
+                       goto consume;
                }
                break;
        }
@@ -6588,7 +6588,7 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb)
        case TCP_CLOSING:
                if (tp->snd_una == tp->write_seq) {
                        tcp_time_wait(sk, TCP_TIME_WAIT, 0);
-                       goto discard;
+                       goto consume;
                }
                break;
 
@@ -6596,7 +6596,7 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb)
                if (tp->snd_una == tp->write_seq) {
                        tcp_update_metrics(sk);
                        tcp_done(sk);
-                       goto discard;
+                       goto consume;
                }
                break;
        }
@@ -6650,6 +6650,10 @@ discard:
                tcp_drop(sk, skb);
        }
        return 0;
+
+consume:
+       __kfree_skb(skb);
+       return 0;
 }
 EXPORT_SYMBOL(tcp_rcv_state_process);