netdev - Re: incorrect cksum with tcp/udp on lo with 2.6.20/2.6.21/2.6.22

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Tue, 2 Oct 2007 18:40:33 +0800
From:	Herbert Xu <herbert@...dor.apana.org.au>
To:	Krzysztof Oledzki <olel@....pl>
Cc:	netdev@...r.kernel.org
Subject: Re: incorrect cksum with tcp/udp on lo with 2.6.20/2.6.21/2.6.22

On Mon, Sep 24, 2007 at 11:44:19AM +0200, Krzysztof Oledzki wrote:
> 
> So, with DR mode, packet goes by the lo device (with bad checksum) and 
> then get redirected outside. Unfortunately, when it leaves host it has bad 
> checksum, too. :(

Did you check this by taking a tcpdump on an external host?
Doing a local tcpdump doesn't work as tcpdump won't show the
correct checksum if checksum offload is enabled.

If it's really sending a bogus checksum then it's a bug in
LVS.

Cheers,
-- 
Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} <herbert@...dor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
-
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html