netdev - Re: Does ICMP_FRAG_NEEDED automatically update the routing cache?

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]

Message-ID: <20140214144412.GA27343@order.stressinduktion.org>
Date:	Fri, 14 Feb 2014 15:44:12 +0100
From:	Hannes Frederic Sowa <hannes@...essinduktion.org>
To:	David Howells <dhowells@...hat.com>
Cc:	netdev@...r.kernel.org
Subject: Re: Does ICMP_FRAG_NEEDED automatically update the routing cache?

Hi!

On Fri, Feb 14, 2014 at 02:36:48PM +0000, David Howells wrote:
> Am I reading the ipv4 code right?  If a UDP packet we send results in an
> ICMP_FRAG_NEEDED packet being received, the cached routing information for the
> peer will automatically be updated by __udp4_lib_err()?

A next hop exception will be generated (or reused) which stores the path
mtu towards that target, yes (there is no more routing cache).

Prior to that a validation check happens if the socket really exists (this is
e.g. needed to identify the namespace or routing table the update should occur
on).

> And something similar in __udp6_lib_err()?

Exactly.

Greetings,

  Hannes

--
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