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authorYuchung Cheng <ycheng@google.com>2018-05-16 16:40:11 -0700
committerDavid S. Miller <davem@davemloft.net>2018-05-17 15:41:28 -0400
commitb38a51fec1c1f693f03b1aa19d0622123634d4b7 (patch)
tree2dfede58dae59faf7da205143e3e00e1833e4bc7 /net/ipv4
parent20b654dfe1beaca60ab51894ff405a049248433d (diff)
tcp: disable RFC6675 loss detection
This patch disables RFC6675 loss detection and make sysctl net.ipv4.tcp_recovery = 1 controls a binary choice between RACK (1) or RFC6675 (0). Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Soheil Hassas Yeganeh <soheil@google.com> Reviewed-by: Priyaranjan Jha <priyarjha@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4')
-rw-r--r--net/ipv4/tcp_input.c12
1 files changed, 8 insertions, 4 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index b188e0d75edd..ccbe04f80040 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -2035,6 +2035,11 @@ static inline int tcp_dupack_heuristics(const struct tcp_sock *tp)
return tp->sacked_out + 1;
}
+static bool tcp_is_rack(const struct sock *sk)
+{
+ return sock_net(sk)->ipv4.sysctl_tcp_recovery & TCP_RACK_LOSS_DETECTION;
+}
+
/* Linux NewReno/SACK/ECN state machine.
* --------------------------------------
*
@@ -2141,7 +2146,7 @@ static bool tcp_time_to_recover(struct sock *sk, int flag)
return true;
/* Not-A-Trick#2 : Classic rule... */
- if (tcp_dupack_heuristics(tp) > tp->reordering)
+ if (!tcp_is_rack(sk) && tcp_dupack_heuristics(tp) > tp->reordering)
return true;
return false;
@@ -2722,8 +2727,7 @@ static void tcp_rack_identify_loss(struct sock *sk, int *ack_flag)
{
struct tcp_sock *tp = tcp_sk(sk);
- /* Use RACK to detect loss */
- if (sock_net(sk)->ipv4.sysctl_tcp_recovery & TCP_RACK_LOSS_DETECTION) {
+ if (tcp_is_rack(sk)) {
u32 prior_retrans = tp->retrans_out;
tcp_rack_mark_lost(sk);
@@ -2862,7 +2866,7 @@ static void tcp_fastretrans_alert(struct sock *sk, const u32 prior_snd_una,
fast_rexmit = 1;
}
- if (do_lost)
+ if (!tcp_is_rack(sk) && do_lost)
tcp_update_scoreboard(sk, fast_rexmit);
*rexmit = REXMIT_LOST;
}