From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Frederic Sowa Subject: Re: Does ICMP_FRAG_NEEDED automatically update the routing cache? Date: Fri, 14 Feb 2014 15:44:12 +0100 Message-ID: <20140214144412.GA27343@order.stressinduktion.org> References: <26474.1392388608@warthog.procyon.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Cc: netdev@vger.kernel.org To: David Howells Return-path: Received: from order.stressinduktion.org ([87.106.68.36]:54990 "EHLO order.stressinduktion.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751059AbaBNOoN (ORCPT ); Fri, 14 Feb 2014 09:44:13 -0500 Content-Disposition: inline In-Reply-To: <26474.1392388608@warthog.procyon.org.uk> Sender: netdev-owner@vger.kernel.org List-ID: 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