From: Brian Haley <brian.haley@hp.com>
To: Al Viro <viro@ftp.linux.org.uk>
Cc: David Miller <davem@davemloft.net>, netdev@vger.kernel.org
Subject: Re: [PATCH] IPv6: optimize echo reply checksum calculation
Date: Fri, 10 Nov 2006 12:51:19 -0500 [thread overview]
Message-ID: <4554BC17.8020809@hp.com> (raw)
In-Reply-To: <20061110173422.GM29920@ftp.linux.org.uk>
Al Viro wrote:
> On Fri, Nov 10, 2006 at 11:25:53AM -0500, Brian Haley wrote:
>> Since the only difference between echo requests and echo replies is the
>> ICMPv6 type value (which is a difference of 1), just subtracting one
>> from the request checksum will result in the correct checksum for the reply.
>
> Um, no. That will *not* result in correct checksum. Please, RTFRFC 1071.
I verified this works for echo request/reply on my IA64 box,
double-checked with ethereal/wireshark. Is there something specific in
RFC 1071 that I should be looking for?
-Brian
next prev parent reply other threads:[~2006-11-10 17:51 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-11-08 22:13 why do we mangle checksums for v6 ICMP? Al Viro
2006-11-08 22:28 ` Al Viro
2006-11-09 17:32 ` Brian Haley
2006-11-09 23:14 ` David Miller
2006-11-10 16:24 ` [PATCH] IPv6: only modify checksum for UDP Brian Haley
2006-11-10 17:54 ` David Stevens
2006-11-14 0:50 ` David Miller
2006-11-14 1:18 ` Al Viro
2006-11-14 1:44 ` David Stevens
2006-11-14 1:52 ` Al Viro
2006-11-10 22:55 ` David Miller
2006-11-10 23:17 ` Nivedita Singhvi
2006-11-10 23:26 ` David Miller
2006-11-10 23:36 ` Nivedita Singhvi
2006-11-12 1:30 ` Brian Haley
2006-11-10 16:25 ` [PATCH] IPv6: optimize echo reply checksum calculation Brian Haley
2006-11-10 17:34 ` Al Viro
2006-11-10 17:51 ` Brian Haley [this message]
2006-11-10 18:05 ` Al Viro
2006-11-10 18:20 ` Al Viro
2006-11-10 19:04 ` Brian Haley
2006-11-10 19:17 ` Al Viro
2006-11-10 21:06 ` Brian Haley
2006-11-11 1:45 ` Al Viro
2006-11-11 18:07 ` why do we mangle checksums for v6 ICMP? Bill Fink
2006-11-13 7:04 ` David Miller
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