Fwd: tcp seq nr wrapping bug + patch

Fwd: tcp seq nr wrapping bug + patch

[Ulrik De Bie]

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Hello,

I resend this patch which fixes a stupid mistake in the tcp sequence number in the 2.2 kernel.

Kind regards,
Ulrik De Bie

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From: "Ulrik De Bie" <ulrik.debie@newtec.be>
To: <alan.cox@linux.org>,<a@oo.ms>
Subject: tcp seq nr wrapping bug + patch
Date: Wed, 11 Sep 2002 17:36:27 +0200

When the sequence number in a tcp session is about to wrap for packets
leaving the system, a problem arises:

When the system call writev is called, with a count of 5 for instance, and the
second iov entry makes the sequence number wrap, then the other 3 will be
sent in separate packets, because the comparison will be wrong.

before() fixes this problem.

Sorry that I'm sending from a windows machine at the moment, I don't have
a linux mail machine available at the very moment.

Kind regards,
Ulrik De Bie
udb@newtec.be




--- linux-2.2.21/net/ipv4/tcp.c	Wed Sep 11 11:03:10 2002
+++ linux/net/ipv4/tcp.c	Wed Sep 11 17:27:53 2002
@@ -823,7 +823,7 @@
 				 */
 				if (skb_tailroom(skb) > 0 &&
 				    (mss_now - copy) > 0 &&
-				    tp->snd_nxt < TCP_SKB_CB(skb)->end_seq) {
+				    before(tp->snd_nxt , TCP_SKB_CB(skb)->end_seq)) {
 					int last_byte_was_odd = (copy % 4);
 
 					/* 

Re: Fwd: tcp seq nr wrapping bug + patch

[James Morris]

On Mon, 10 Mar 2003, Ulrik De Bie wrote:

> I resend this patch which fixes a stupid mistake in the tcp sequence
> number in the 2.2 kernel.

This looks good, thanks.

Alan, please apply.


- James
-- 
James Morris
<jmorris@intercode.com.au>


diff -urN -X dontdiff linux-2.2.24.orig/net/ipv4/tcp.c linux-2.2.24.w1/net/ipv4/tcp.c
--- linux-2.2.24.orig/net/ipv4/tcp.c	Wed Sep 25 00:06:26 2002
+++ linux-2.2.24.w1/net/ipv4/tcp.c	Tue Mar 11 23:26:00 2003
@@ -823,7 +823,7 @@
 				 */
 				if (skb_tailroom(skb) > 0 &&
 				    (mss_now - copy) > 0 &&
-				    tp->snd_nxt < TCP_SKB_CB(skb)->end_seq) {
+				    before(tp->snd_nxt, TCP_SKB_CB(skb)->end_seq)) {
 					int last_byte_was_odd = (copy % 4);
 
 					/*