diff options
Diffstat (limited to 'net/ipv4/tcp_input.c')
| -rw-r--r-- | net/ipv4/tcp_input.c | 17 |
1 files changed, 15 insertions, 2 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 9da9f19ece8a..f79a51607292 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -811,12 +811,25 @@ void tcp_update_metrics(struct sock *sk) } } +/* Numbers are taken from RFC3390. + * + * John Heffner states: + * + * The RFC specifies a window of no more than 4380 bytes + * unless 2*MSS > 4380. Reading the pseudocode in the RFC + * is a bit misleading because they use a clamp at 4380 bytes + * rather than use a multiplier in the relevant range. + */ __u32 tcp_init_cwnd(struct tcp_sock *tp, struct dst_entry *dst) { __u32 cwnd = (dst ? dst_metric(dst, RTAX_INITCWND) : 0); - if (!cwnd) - cwnd = rfc3390_bytes_to_packets(tp->mss_cache); + if (!cwnd) { + if (tp->mss_cache > 1460) + cwnd = 2; + else + cwnd = (tp->mss_cache > 1095) ? 3 : 4; + } return min_t(__u32, cwnd, tp->snd_cwnd_clamp); } |