From 18ab4520fd46404b67d415045ee5d9c4535eaacb Mon Sep 17 00:00:00 2001
From: Nandita Dukkipati <nanditad@google.com>
Date: Fri, 3 Dec 2010 13:33:44 +0000
Subject: tcp: Bug fix in initialization of receive window.


From: Nandita Dukkipati <nanditad@google.com>

[ Upstream commit b1afde60f2b9ee8444fba4e012dc99a3b28d224d ]

The bug has to do with boundary checks on the initial receive window.
If the initial receive window falls between init_cwnd and the
receive window specified by the user, the initial window is incorrectly
brought down to init_cwnd. The correct behavior is to allow it to
remain unchanged.

Signed-off-by: Nandita Dukkipati <nanditad@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
 net/ipv4/tcp_output.c |    9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -237,11 +237,10 @@ void tcp_select_initial_window(int __spa
 		/* when initializing use the value from init_rcv_wnd
 		 * rather than the default from above
 		 */
-		if (init_rcv_wnd &&
-		    (*rcv_wnd > init_rcv_wnd * mss))
-			*rcv_wnd = init_rcv_wnd * mss;
-		else if (*rcv_wnd > init_cwnd * mss)
-			*rcv_wnd = init_cwnd * mss;
+		if (init_rcv_wnd)
+			*rcv_wnd = min(*rcv_wnd, init_rcv_wnd * mss);
+		else
+			*rcv_wnd = min(*rcv_wnd, init_cwnd * mss);
 	}
 
 	/* Set the clamp no higher than max representable value */