netdev - Re: [PATCH 1/2] [IPV4] UDP: Always checksum even if without socket filter

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 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:	Thu, 29 Nov 2007 15:55:38 +0800
From:	Wang Chen <wangchen@...fujitsu.com>
To:	David Miller <davem@...emloft.net>
CC:	andi@...stfloor.org, billfink@...dspring.com,
	herbert@...dor.apana.org.au, netdev@...r.kernel.org,
	gerrit@....abdn.ac.uk, bfields@...ldses.org, neilb@...e.de,
	okir@...ad.swb.de, Wang Chen <wangchen@...fujitsu.com>
Subject: Re: [PATCH 1/2] [IPV4] UDP: Always checksum even if without socket
 filter

David Miller said the following on 2007-11-21 9:39:
> From: Andi Kleen <andi@...stfloor.org>
> Date: Tue, 20 Nov 2007 15:05:18 +0100
> 
>> On Tue, Nov 20, 2007 at 12:29:45AM -0500, Bill Fink wrote:
>>> While I agree with your analysis that it could be worked around,
>>> who knows how all the various SNMP monitoring applications out there
>>> would interpret such an unusual event.  I liked Stephen's suggestion
>>> of a deferred decrement that would insure the counter didn't ever
>>> run backwards.  But the best approach seems to be just not to count
>>> it in the first place until tha application has actually received
>>> the packet, since as Herbert pointed out, that's what the RFC
>>> actually specifies for the meaning of the udpInDatagrams counter.
>> Together with another counter that counts "edge datagrams received"
>> that would be an excellent idea.
>>
>> Here's a patch.
> 
> NFS and friends that use the ->data_ready() callback needs to
> be updated as well.  Please fix this and resubmit, thanks.
> 

I tested nfsv3 & nfsv4. It seems that nfs calls recvmsg() like
following:nfsd()->svc_recv()->svc_udp_recvfrom()->udp_recvmsg().
So, I think putting the udpInDatagrams increment in udp_recvmsg()
is enough.

FYI:
http://www.mail-archive.com/netdev@vger.kernel.org/msg13817.html


-
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