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]

Date:	Fri, 14 Feb 2014 15:00:42 +0000
From:	David Howells <dhowells@...hat.com>
To:	Hannes Frederic Sowa <hannes@...essinduktion.org>
Cc:	dhowells@...hat.com, netdev@...r.kernel.org
Subject: Re: Does ICMP_FRAG_NEEDED automatically update the routing cache?

Hannes Frederic Sowa <hannes@...essinduktion.org> wrote:

> 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).

Sounds good.  Does this work even if the socket is not connected (ie. the UDP
packets are being routed by the address fields in struct msghdr)?

David
--
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