[TCP]: Add H-TCP congestion control module.

H-TCP is a congestion control algorithm developed at the Hamilton Institute, by
Douglas Leith and Robert Shorten. It is extending the standard Reno algorithm
with mode switching is thus a relatively simple modification.

H-TCP is defined in a layered manner as it is still a research platform. The
basic form includes the modification of beta according to the ratio of maxRTT
to min RTT and the alpha=2*factor*(1-beta) relation, where factor is dependant
on the time since last congestion.

The other layers improve convergence by adding appropriate factors to alpha.

The following patch implements the H-TCP algorithm in it's basic form.

Signed-Off-By: Baruch Even <baruch@ev-en.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/Kconfig

@@ -467,6 +467,18 @@ config TCP_CONG_WESTWOOD
 	TCP Westwood+ significantly increases fairness wrt TCP Reno in
 	wired networks and throughput over wireless links.
 
+config TCP_CONG_HTCP
+        tristate "H-TCP"
+	depends on INET
+        default m
+	---help---
+	H-TCP is a send-side only modifications of the TCP Reno
+	protocol stack that optimizes the performance of TCP
+	congestion control for high speed network links. It uses a
+	modeswitch to change the alpha and beta parameters of TCP Reno
+	based on network conditions and in a way so as to be fair with
+	other Reno and H-TCP flows.
+
 config TCP_CONG_HSTCP
 	tristate "High Speed TCP"
 	depends on INET && EXPERIMENTAL
@@ -499,6 +511,7 @@ config TCP_CONG_VEGAS
 	window. TCP Vegas should provide less packet loss, but it is
 	not as aggressive as TCP Reno.
 
+
 endmenu
 
 source "net/ipv4/ipvs/Kconfig"