Commit bef5767f authored by Yuchung Cheng's avatar Yuchung Cheng Committed by David S. Miller

tcp: better delivery accounting for SYN-ACK and SYN-data

the tcp_sock:delivered has inconsistent accounting for SYN and FIN.
1. it counts pure FIN
2. it counts pure SYN
3. it counts SYN-data twice
4. it does not count SYN-ACK

For congestion control perspective it does not matter much as C.C. only
cares about the difference not the aboslute value. But the next patch
would export this field to user-space so it's better to report the absolute
value w/o these caveats.

This patch counts SYN, SYN-ACK, or SYN-data delivery once always in
the "delivered" field.
Signed-off-by: default avatarYuchung Cheng <ycheng@google.com>
Reviewed-by: default avatarNeal Cardwell <ncardwell@google.com>
Reviewed-by: default avatarSoheil Hassas Yeganeh <soheil@google.com>
Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 415787d7
...@@ -5567,9 +5567,12 @@ static bool tcp_rcv_fastopen_synack(struct sock *sk, struct sk_buff *synack, ...@@ -5567,9 +5567,12 @@ static bool tcp_rcv_fastopen_synack(struct sock *sk, struct sk_buff *synack,
return true; return true;
} }
tp->syn_data_acked = tp->syn_data; tp->syn_data_acked = tp->syn_data;
if (tp->syn_data_acked) if (tp->syn_data_acked) {
NET_INC_STATS(sock_net(sk), NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPFASTOPENACTIVE);
LINUX_MIB_TCPFASTOPENACTIVE); /* SYN-data is counted as two separate packets in tcp_ack() */
if (tp->delivered > 1)
--tp->delivered;
}
tcp_fastopen_add_skb(sk, synack); tcp_fastopen_add_skb(sk, synack);
...@@ -5901,6 +5904,7 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb) ...@@ -5901,6 +5904,7 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb)
} }
switch (sk->sk_state) { switch (sk->sk_state) {
case TCP_SYN_RECV: case TCP_SYN_RECV:
tp->delivered++; /* SYN-ACK delivery isn't tracked in tcp_ack */
if (!tp->srtt_us) if (!tp->srtt_us)
tcp_synack_rtt_meas(sk, req); tcp_synack_rtt_meas(sk, req);
......
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