bpf: Support for per connection SYN/SYN-ACK RTOs

This patch adds support for setting a per connection SYN and
SYN_ACK RTOs from within a BPF_SOCK_OPS program. For example,
to set small RTOs when it is known both hosts are within a
datacenter.

Signed-off-by: Lawrence Brakmo <brakmo@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 3 insertions, 2 deletions

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 2ab7e2fa9bb9..bcc96654cd7e 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -6406,7 +6406,8 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops,
         } else {
                 tcp_rsk(req)->tfo_listener = false;
                 if (!want_cookie)
-                        inet_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
+                        inet_csk_reqsk_queue_hash_add(sk, req,
+                                tcp_timeout_init((struct sock *)req));
                 af_ops->send_synack(sk, dst, &fl, req, &foc,
                                     !want_cookie ? TCP_SYNACK_NORMAL :
                                                    TCP_SYNACK_COOKIE);
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 1d79137f3795..47fe0759a877 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -3326,7 +3326,7 @@ static void tcp_connect_init(struct sock *sk)
         tp->rcv_wup = tp->rcv_nxt;
         tp->copied_seq = tp->rcv_nxt;
 
-        inet_csk(sk)->icsk_rto = TCP_TIMEOUT_INIT;
+        inet_csk(sk)->icsk_rto = tcp_timeout_init(sk);
         inet_csk(sk)->icsk_retransmits = 0;
         tcp_clear_retrans(tp);
 }