tcp/dccp: Consolidate common code for RFC 3390 conversion
This patch consolidates initial-window 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 <gerrit@erg.abdn.ac.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/dccp/ccids/ccid2.c b/net/dccp/ccids/ccid2.c
index 8c95813..b9c942a 100644
--- a/net/dccp/ccids/ccid2.c
+++ b/net/dccp/ccids/ccid2.c
@@ -641,12 +641,8 @@
/* RFC 4341, 5: initialise ssthresh to arbitrarily high (max) value */
hc->tx_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.
- */
- hc->tx_cwnd = clamp(4380U / dp->dccps_mss_cache, 2U, 4U);
+ /* Use larger initial windows (RFC 4341, section 5). */
+ hc->tx_cwnd = rfc3390_bytes_to_packets(dp->dccps_mss_cache);
/* Make sure that Ack Ratio is enabled and within bounds. */
max_ratio = DIV_ROUND_UP(hc->tx_cwnd, 2);
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index e663b78..1bc87a05 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -805,25 +805,12 @@
}
}
-/* 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);
}
