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>

1 files changed, 2 insertions, 15 deletions

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index e663b78a2ef6..1bc87a05c734 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -805,25 +805,12 @@ 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);
 }