From mboxrd@z Thu Jan 1 00:00:00 1970 From: bert hubert Subject: ip6sec MTU/fragmentation issue / Was: Re: [PATCH] Fix ip6_build_xmit bug Date: Sat, 22 Mar 2003 20:26:04 +0100 Sender: netdev-bounce@oss.sgi.com Message-ID: <20030322192604.GA3011@outpost.ds9a.nl> References: <3E7BAC7E.AEC59251@us.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: "linux-net@vger.kernel.org" , "netdev@oss.sgi.com" Return-path: To: Jon Grimm Content-Disposition: inline In-Reply-To: <3E7BAC7E.AEC59251@us.ibm.com> Errors-to: netdev-bounce@oss.sgi.com List-Id: netdev.vger.kernel.org On Fri, Mar 21, 2003 at 06:21:18PM -0600, Jon Grimm wrote: > Wanting to play a bit with v6 fragmentation I started using ping6 to > send various message sizes. Noticed that messages of sizes just under > where fragmentation would kick in, segfaulted in ip6_build_xmit(). Thanks, this fixes an observed issue here with segfaults in ping6, as you described. I run 2.5.65. There is another problem with ip6sec however where fragmentation fails. Setting up an ip6sec connection and then sending bulk data freezes up a connection. ping6 -s 1500 deef.ds9a.nl -n leads to: 20:16:18.125073 2001:888:1036:0:2a0:ccff:fec8:f25c > 2001:888:1036:0:2e0:18ff:fe23:cece: AH(spi=0x00003d54,sumlen=16,seq=0xbe): ESP(spi=0x00003d55,seq=0xbe) (len 1504, hlim 64) 20:16:18.125129 2001:888:1036:0:2a0:ccff:fec8:f25c > 2001:888:1036:0:2e0:18ff:fe23:cece: AH(spi=0x00003d54,sumlen=16,seq=0xbf): ESP(spi=0x00003d55,seq=0xbf) (len 112, hlim 64) and a reply: 20:16:18.125474 2001:888:1036:0:2e0:18ff:fe23:cece > 2001:888:1036:0:2a0:ccff:fec8:f25c: AH(spi=0x00005fb4,sumlen=16,seq=0x82): ESP(spi=0x00005fb5,seq=0x82) [hlim 0] (len 160) The reply appears to be a bit short and is possibly an ICMP error. When I configure ip6sec only in one way, I get this reply to fragmented ICMP echo requests: 20:22:24.445157 2001:888:1036:0:2e0:18ff:fe23:cece > 2001:888:1036:0:2a0:ccff:fec8:f25c: icmp6: parameter problem next header - octet 6 (len 116, hlim 64) This is probably the same packet as we see encrypted above. Working ping6, -s 1400, looks like this: 20:18:56.820699 2001:888:1036:0:2a0:ccff:fec8:f25c > 2001:888:1036:0:2e0:18ff:fe23:cece: AH(spi=0x00003d54,sumlen=16,seq=0x142): ESP(spi=0x00003d55,seq=0x142) (len 1456, hlim 64) 20:18:56.821912 2001:888:1036:0:2e0:18ff:fe23:cece > 2001:888:1036:0:2a0:ccff:fec8:f25c: AH(spi=0x00005fb4,sumlen=16,seq=0xce): ESP(spi=0x00005fb5,seq=0xce) [hlim 0] (len 1456) Both of these hosts have your patch applied. So it seems that ip6sec fragmentation has some issues. Thanks. -- http://www.PowerDNS.com Open source, database driven DNS Software http://lartc.org Linux Advanced Routing & Traffic Control HOWTO http://netherlabs.nl Consulting