diff options
| author | Yuchung Cheng <ycheng@google.com> | 2014-05-12 07:22:11 +0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2014-05-14 01:53:02 +0400 |
| commit | 843f4a55e336e6d0c7bb92e7f9621535bc8d5fcd (patch) | |
| tree | 17010fcb1b56174476b471758c3ca4f825ccbe7f /net/ipv4/tcp_minisocks.c | |
| parent | 89278c9dc922272df921042aafa18311f3398c6c (diff) | |
| download | linux-843f4a55e336e6d0c7bb92e7f9621535bc8d5fcd.tar.xz | |
tcp: use tcp_v4_send_synack on first SYN-ACK
To avoid large code duplication in IPv6, we need to first simplify
the complicate SYN-ACK sending code in tcp_v4_conn_request().
To use tcp_v4(6)_send_synack() to send all SYN-ACKs, we need to
initialize the mini socket's receive window before trying to
create the child socket and/or building the SYN-ACK packet. So we move
that initialization from tcp_make_synack() to tcp_v4_conn_request()
as a new function tcp_openreq_init_req_rwin().
After this refactoring the SYN-ACK sending code is simpler and easier
to implement Fast Open for IPv6.
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Daniel Lee <longinus00@gmail.com>
Signed-off-by: Jerry Chu <hkchu@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp_minisocks.c')
| -rw-r--r-- | net/ipv4/tcp_minisocks.c | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c index 05c1b155251d..e68e0d4af6c9 100644 --- a/net/ipv4/tcp_minisocks.c +++ b/net/ipv4/tcp_minisocks.c @@ -362,6 +362,37 @@ void tcp_twsk_destructor(struct sock *sk) } EXPORT_SYMBOL_GPL(tcp_twsk_destructor); +void tcp_openreq_init_rwin(struct request_sock *req, + struct sock *sk, struct dst_entry *dst) +{ + struct inet_request_sock *ireq = inet_rsk(req); + struct tcp_sock *tp = tcp_sk(sk); + __u8 rcv_wscale; + int mss = dst_metric_advmss(dst); + + if (tp->rx_opt.user_mss && tp->rx_opt.user_mss < mss) + mss = tp->rx_opt.user_mss; + + /* Set this up on the first call only */ + req->window_clamp = tp->window_clamp ? : dst_metric(dst, RTAX_WINDOW); + + /* limit the window selection if the user enforce a smaller rx buffer */ + if (sk->sk_userlocks & SOCK_RCVBUF_LOCK && + (req->window_clamp > tcp_full_space(sk) || req->window_clamp == 0)) + req->window_clamp = tcp_full_space(sk); + + /* tcp_full_space because it is guaranteed to be the first packet */ + tcp_select_initial_window(tcp_full_space(sk), + mss - (ireq->tstamp_ok ? TCPOLEN_TSTAMP_ALIGNED : 0), + &req->rcv_wnd, + &req->window_clamp, + ireq->wscale_ok, + &rcv_wscale, + dst_metric(dst, RTAX_INITRWND)); + ireq->rcv_wscale = rcv_wscale; +} +EXPORT_SYMBOL(tcp_openreq_init_rwin); + static inline void TCP_ECN_openreq_child(struct tcp_sock *tp, struct request_sock *req) { |