From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nandita Dukkipati Subject: [PATCH 1/1] TCP: Bug fix in initialization of receive window. Date: Fri, 3 Dec 2010 15:33:44 -0800 Message-ID: <1291419224-20853-1-git-send-email-nanditad@google.com> Cc: Laurent Chavey , Yuchung Cheng , netdev@vger.kernel.org, Nandita Dukkipati To: "David S. Miller" Return-path: Received: from smtp-out.google.com ([216.239.44.51]:39000 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753896Ab0LCXeL (ORCPT ); Fri, 3 Dec 2010 18:34:11 -0500 Sender: netdev-owner@vger.kernel.org List-ID: 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 --- net/ipv4/tcp_output.c | 9 ++++----- 1 files changed, 4 insertions(+), 5 deletions(-) diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 749b649..31fd0bd 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -231,11 +231,10 @@ void tcp_select_initial_window(int __space, __u32 mss, /* 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 */ -- 1.7.3.1