From 6224877b2ca4be5de96270a8ae490fe2ba11b0e0 Mon Sep 17 00:00:00 2001 From: Gerrit Renker Date: Thu, 4 Sep 2008 07:30:19 +0200 Subject: tcp/dccp: Consolidate common code for RFC 3390 conversion This patch consolidates the code common to TCP and CCID-2: * TCP uses RFC 3390 in a packet-oriented manner (tcp_input.c) and * CCID-2 uses RFC 3390 in packet-oriented manner (RFC 4341). Signed-off-by: Gerrit Renker --- net/dccp/ccids/ccid2.c | 8 ++------ net/ipv4/tcp_input.c | 17 ++--------------- 2 files changed, 4 insertions(+), 21 deletions(-) (limited to 'net') diff --git a/net/dccp/ccids/ccid2.c b/net/dccp/ccids/ccid2.c index c539f79..fa71322 100644 --- a/net/dccp/ccids/ccid2.c +++ b/net/dccp/ccids/ccid2.c @@ -596,12 +596,8 @@ static int ccid2_hc_tx_init(struct ccid *ccid, struct sock *sk) /* RFC 4341, 5: initialise ssthresh to arbitrarily high (max) value */ hctx->ssthresh = ~0U; - /* - * RFC 4341, 5: "The cwnd parameter is initialized to at most four - * packets for new connections, following the rules from [RFC3390]". - * We need to convert the bytes of RFC3390 into the packets of RFC 4341. - */ - hctx->cwnd = clamp(4380U / dp->dccps_mss_cache, 2U, 4U); + /* Use larger initial windows (RFC 3390, rfc2581bis) */ + hctx->cwnd = rfc3390_bytes_to_packets(dp->dccps_mss_cache); /* Make sure that Ack Ratio is enabled and within bounds. */ max_ratio = DIV_ROUND_UP(hctx->cwnd, 2); diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 67ccce2..16d0040 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -811,25 +811,12 @@ 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) { - if (tp->mss_cache > 1460) - cwnd = 2; - else - cwnd = (tp->mss_cache > 1095) ? 3 : 4; - } + if (!cwnd) + cwnd = rfc3390_bytes_to_packets(tp->mss_cache); return min_t(__u32, cwnd, tp->snd_cwnd_clamp); } -- cgit v1.1