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| author | Yuchung Cheng <ycheng@google.com> | 2012-07-19 06:43:08 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2012-07-19 11:02:03 -0700 |
| commit | 8e4178c1c7b52f7c99f5fd22ef7af6b2bff409e3 (patch) | |
| tree | 101ec972d397346ea603ee2a08b8320f1ed690eb /net/ipv4 | |
| parent | 783237e8daf13481ee234997cbbbb823872ac388 (diff) | |
| download | linux-8e4178c1c7b52f7c99f5fd22ef7af6b2bff409e3.tar.gz linux-8e4178c1c7b52f7c99f5fd22ef7af6b2bff409e3.tar.bz2 linux-8e4178c1c7b52f7c99f5fd22ef7af6b2bff409e3.zip | |
net-tcp: Fast Open client - receiving SYN-ACK
On receiving the SYN-ACK after SYN-data, the client needs to
a) update the cached MSS and cookie (if included in SYN-ACK)
b) retransmit the data not yet acknowledged by the SYN-ACK in the final ACK of
the handshake.
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4')
| -rw-r--r-- | net/ipv4/tcp_input.c | 40 |
1 files changed, 35 insertions, 5 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index a06bb8959e7e..38b6a811edfc 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -5646,6 +5646,34 @@ void tcp_finish_connect(struct sock *sk, struct sk_buff *skb) } } +static bool tcp_rcv_fastopen_synack(struct sock *sk, struct sk_buff *synack, + struct tcp_fastopen_cookie *cookie) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct sk_buff *data = tcp_write_queue_head(sk); + u16 mss = tp->rx_opt.mss_clamp; + + if (mss == tp->rx_opt.user_mss) { + struct tcp_options_received opt; + const u8 *hash_location; + + /* Get original SYNACK MSS value if user MSS sets mss_clamp */ + tcp_clear_options(&opt); + opt.user_mss = opt.mss_clamp = 0; + tcp_parse_options(synack, &opt, &hash_location, 0, NULL); + mss = opt.mss_clamp; + } + + tcp_fastopen_cache_set(sk, mss, cookie); + + if (data) { /* Retransmit unacked data in SYN */ + tcp_retransmit_skb(sk, data); + tcp_rearm_rto(sk); + return true; + } + return false; +} + static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb, const struct tcphdr *th, unsigned int len) { @@ -5653,9 +5681,10 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb, struct inet_connection_sock *icsk = inet_csk(sk); struct tcp_sock *tp = tcp_sk(sk); struct tcp_cookie_values *cvp = tp->cookie_values; + struct tcp_fastopen_cookie foc = { .len = -1 }; int saved_clamp = tp->rx_opt.mss_clamp; - tcp_parse_options(skb, &tp->rx_opt, &hash_location, 0, NULL); + tcp_parse_options(skb, &tp->rx_opt, &hash_location, 0, &foc); if (th->ack) { /* rfc793: @@ -5665,11 +5694,9 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb, * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send * a reset (unless the RST bit is set, if so drop * the segment and return)" - * - * We do not send data with SYN, so that RFC-correct - * test reduces to: */ - if (TCP_SKB_CB(skb)->ack_seq != tp->snd_nxt) + if (!after(TCP_SKB_CB(skb)->ack_seq, tp->snd_una) || + after(TCP_SKB_CB(skb)->ack_seq, tp->snd_nxt)) goto reset_and_undo; if (tp->rx_opt.saw_tstamp && tp->rx_opt.rcv_tsecr && @@ -5781,6 +5808,9 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb, tcp_finish_connect(sk, skb); + if (tp->syn_fastopen && tcp_rcv_fastopen_synack(sk, skb, &foc)) + return -1; + if (sk->sk_write_pending || icsk->icsk_accept_queue.rskq_defer_accept || icsk->icsk_ack.pingpong) { |