tcp: Refactor pingpong code

Instead of using pingpong as a single bit information, we refactor the
code to treat it as a counter. When interactive session is detected,
we set pingpong count to TCP_PINGPONG_THRESH. And when pingpong count
is >= TCP_PINGPONG_THRESH, we consider the session in pingpong mode.

This patch is a pure refactor and sets foundation for the next patch.
This patch itself does not change any pingpong logic.

Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 4 deletions

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 76858b14ebe9..7a027dec649b 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -221,7 +221,7 @@ void tcp_enter_quickack_mode(struct sock *sk, unsigned int max_quickacks)
         struct inet_connection_sock *icsk = inet_csk(sk);
 
         tcp_incr_quickack(sk, max_quickacks);
-        icsk->icsk_ack.pingpong = 0;
+        inet_csk_exit_pingpong_mode(sk);
         icsk->icsk_ack.ato = TCP_ATO_MIN;
 }
 EXPORT_SYMBOL(tcp_enter_quickack_mode);
@@ -236,7 +236,7 @@ static bool tcp_in_quickack_mode(struct sock *sk)
         const struct dst_entry *dst = __sk_dst_get(sk);
 
         return (dst && dst_metric(dst, RTAX_QUICKACK)) ||
-                (icsk->icsk_ack.quick && !icsk->icsk_ack.pingpong);
+                (icsk->icsk_ack.quick && !inet_csk_in_pingpong_mode(sk));
 }
 
 static void tcp_ecn_queue_cwr(struct tcp_sock *tp)
@@ -4094,7 +4094,7 @@ void tcp_fin(struct sock *sk)
         case TCP_ESTABLISHED:
                 /* Move to CLOSE_WAIT */
                 tcp_set_state(sk, TCP_CLOSE_WAIT);
-                inet_csk(sk)->icsk_ack.pingpong = 1;
+                inet_csk_enter_pingpong_mode(sk);
                 break;
 
         case TCP_CLOSE_WAIT:
@@ -5889,7 +5889,7 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb,
                         return -1;
                 if (sk->sk_write_pending ||
                     icsk->icsk_accept_queue.rskq_defer_accept ||
-                    icsk->icsk_ack.pingpong) {
+                    inet_csk_in_pingpong_mode(sk)) {
                         /* Save one ACK. Data will be ready after
                          * several ticks, if write_pending is set.
                          *