diff --git a/include/linux/rtnetlink.h b/include/linux/rtnetlink.h index c91476ce314a..dff3192374f8 100644 --- a/include/linux/rtnetlink.h +++ b/include/linux/rtnetlink.h @@ -351,6 +351,8 @@ enum #define RTAX_INITCWND RTAX_INITCWND RTAX_FEATURES, #define RTAX_FEATURES RTAX_FEATURES + RTAX_RTO_MIN, +#define RTAX_RTO_MIN RTAX_RTO_MIN __RTAX_MAX }; diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 9785df37a65f..1ee72127462b 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -555,6 +555,16 @@ static void tcp_event_data_recv(struct sock *sk, struct sk_buff *skb) tcp_grow_window(sk, skb); } +static u32 tcp_rto_min(struct sock *sk) +{ + struct dst_entry *dst = __sk_dst_get(sk); + u32 rto_min = TCP_RTO_MIN; + + if (dst_metric_locked(dst, RTAX_RTO_MIN)) + rto_min = dst->metrics[RTAX_RTO_MIN-1]; + return rto_min; +} + /* Called to compute a smoothed rtt estimate. The data fed to this * routine either comes from timestamps, or from segments that were * known _not_ to have been retransmitted [see Karn/Partridge @@ -616,13 +626,13 @@ static void tcp_rtt_estimator(struct sock *sk, const __u32 mrtt) if (tp->mdev_max < tp->rttvar) tp->rttvar -= (tp->rttvar-tp->mdev_max)>>2; tp->rtt_seq = tp->snd_nxt; - tp->mdev_max = TCP_RTO_MIN; + tp->mdev_max = tcp_rto_min(sk); } } else { /* no previous measure. */ tp->srtt = m<<3; /* take the measured time to be rtt */ tp->mdev = m<<1; /* make sure rto = 3*rtt */ - tp->mdev_max = tp->rttvar = max(tp->mdev, TCP_RTO_MIN); + tp->mdev_max = tp->rttvar = max(tp->mdev, tcp_rto_min(sk)); tp->rtt_seq = tp->snd_nxt; } }