diff options
| author | Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> | 2008-09-20 21:21:54 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2008-09-20 21:21:54 -0700 |
| commit | b5afe7bc71a1689376c9b547376d17568469f3b3 (patch) | |
| tree | 30a790da358ea20c790e16f87a4dcddc83cdb316 | |
| parent | 184d68b2b0b836587f92887b14baea41033ffeef (diff) | |
tcp: add tcp_can_forward_retransmit
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/ipv4/tcp_output.c | 46 |
1 files changed, 28 insertions, 18 deletions
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index cfae61b40c44..957c4e3d2176 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -1992,6 +1992,33 @@ int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb) return err; } +static int tcp_can_forward_retransmit(struct sock *sk) +{ + const struct inet_connection_sock *icsk = inet_csk(sk); + struct tcp_sock *tp = tcp_sk(sk); + + /* Forward retransmissions are possible only during Recovery. */ + if (icsk->icsk_ca_state != TCP_CA_Recovery) + return 0; + + /* No forward retransmissions in Reno are possible. */ + if (tcp_is_reno(tp)) + return 0; + + /* Yeah, we have to make difficult choice between forward transmission + * and retransmission... Both ways have their merits... + * + * For now we do not retransmit anything, while we have some new + * segments to send. In the other cases, follow rule 3 for + * NextSeg() specified in RFC3517. + */ + + if (tcp_may_send_now(sk)) + return 0; + + return 1; +} + /* This gets called after a retransmit timeout, and the initially * retransmitted data is acknowledged. It tries to continue * resending the rest of the retransmit queue, until either @@ -2057,24 +2084,7 @@ void tcp_xmit_retransmit_queue(struct sock *sk) } /* OK, demanded retransmission is finished. */ - - /* Forward retransmissions are possible only during Recovery. */ - if (icsk->icsk_ca_state != TCP_CA_Recovery) - return; - - /* No forward retransmissions in Reno are possible. */ - if (tcp_is_reno(tp)) - return; - - /* Yeah, we have to make difficult choice between forward transmission - * and retransmission... Both ways have their merits... - * - * For now we do not retransmit anything, while we have some new - * segments to send. In the other cases, follow rule 3 for - * NextSeg() specified in RFC3517. - */ - - if (tcp_may_send_now(sk)) + if (!tcp_can_forward_retransmit(sk)) return; /* If nothing is SACKed, highest_sack in the loop won't be valid */ |