netdev - Re: IPsec PMTUD problem

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:	Thu, 05 Apr 2007 14:09:20 +0200
From:	Patrick McHardy <kaber@...sh.net>
To:	Herbert Xu <herbert@...dor.apana.org.au>
CC:	Linux Netdev List <netdev@...r.kernel.org>
Subject: Re: IPsec PMTUD problem

Herbert Xu wrote:
> On Tue, Apr 03, 2007 at 06:32:07PM +0200, Patrick McHardy wrote:
> 
>>I'm not sure I understand how this would work, the ICMP message
>>looks the same in both cases. Or are you suggesting to
>>differentiate based on the source of the ICMP message?
> 
> 
> Actually you're right, this can't work in the general case.  Even
> if we had real devices for IPsec tunnels, there is still no way to
> reliably figure out which device we should attribute a given MTU
> event to if the same address appears on more than one device.
> 
> 
>>Yes, that would work as a workaround, but it still seems like
>>something worth fixing.
> 
> 
> One possible solution is to not send MTU errors to ourselves since
> we it wouldn't give us any new information.  We'd need to audit the
> users of icmp_send to make sure that there isn't a legitimate case
> where we'd want to do that.


One such case is delivery of errors to sockets. We'd need to make
sure the errors are delivered some other way.
-
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