From: Stephen Hemminger <shemminger@osdl.org>
To: "David S. Miller" <davem@davemloft.net>
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] tcp: limit window scaling if window is clamped
Date: Fri, 18 Aug 2006 10:29:38 -0700 [thread overview]
Message-ID: <20060818102938.5abc1bcf@dxpl.pdx.osdl.net> (raw)
This small change allows for easy per-route workarounds for broken hosts or
middleboxes that are not compliant with TCP standards for window scaling.
Rather than having to turn off window scaling globally. This patch allows
reducing or disabling window scaling if window clamp is present.
Example: Mark Lord reported a problem with 2.6.17 kernel being unable to
access http://www.everymac.com
# ip route add 216.145.246.23/32 via 10.8.0.1 window 65535
I would argue this ought to go in stable kernel as well.
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
--- net-2.6.19.orig/net/ipv4/tcp_output.c
+++ net-2.6.19/net/ipv4/tcp_output.c
@@ -201,6 +201,7 @@ void tcp_select_initial_window(int __spa
* See RFC1323 for an explanation of the limit to 14
*/
space = max_t(u32, sysctl_tcp_rmem[2], sysctl_rmem_max);
+ space = min_t(u32, space, *window_clamp);
while (space > 65535 && (*rcv_wscale) < 14) {
space >>= 1;
(*rcv_wscale)++;
next reply other threads:[~2006-08-18 17:29 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-08-18 17:29 Stephen Hemminger [this message]
2006-08-19 0:00 ` [PATCH] tcp: limit window scaling if window is clamped David Miller
2006-08-19 3:03 ` Stephen Hemminger
2006-08-22 7:07 ` David Miller
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20060818102938.5abc1bcf@dxpl.pdx.osdl.net \
--to=shemminger@osdl.org \
--cc=davem@davemloft.net \
--cc=linux-kernel@vger.kernel.org \
--cc=netdev@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).