Re: PROBLEM: IPv6 TCP-Connections resetting

[Hannes Frederic Sowa <hannes@stressinduktion.org>]

[no comments from me - only forwarded to netdev@vger.kernel.org, Duan
Jiong and Steffen Klassert]

On Fri, Apr 05, 2013 at 05:48:28PM +0200, Tetja Rediske wrote:
> Hi,
> 
> [1.] One line summary of the problem:
> 
> IPv6 TCP-Connections resetting 
> 
> [2.] Full description of the problem/report:
> 
> In the last weeks we updated some of our systems to a 3.8.4 Kernel.
> Since then sometimes we can't connect to services running IPv6,
> Apache and Openssh tested. 
> 
> We got this on different machines with x86 and x86_64 Kernels. On
> x86_64 it is more random, but on x86 i can reproduce it permanently
> (Just opening any TCP Connection 1st time or after some short delay).
> Connecting quick after the reset again will work as expected. It will
> also work, if you keep another connection open.
> 
> Before I got to the Kernel, I just kept an strace on an userspace
> process, but it did not notice the connection attempt. After this I
> monitored the connection with tcpdump, but nothing unusual.
> 
> Then I did a rollback to the older Kernel and it worked as expected.
> 
> I tracked it down with 'git bisect' to commit:
> 
>   093d04d42fa094f6740bb188f0ad0c215ff61e2c
> 
> I also tested latest git state available.
> 
> [3.] Keywords (i.e., modules, networking, kernel):
> 
> networking, IPv6
> 
> [4.] Kernel information
> [4.1.] Kernel version (from /proc/version): 
> 
>   since commit: 093d04d42fa094f6740bb188f0ad0c215ff61e2c
> 
> [4.2.] Kernel .config file:
> [5.] Most recent kernel version which did not have the bug:
> 
> none
> 
> [6.] Output of Oops.. message (if applicable) with symbolic information
>      resolved (see Documentation/oops-tracing.txt)
> [7.] A small shell script or example program which triggers the
>      problem (if possible)
> [8.] Environment
> [8.1.] Software (add the output of the ver_linux script here)
> 
> Different systems, mostly reproduced on this one:
> 
> Linux dns03.tetja.de 3.9.0-rc5+ #10 SMP Fri Apr 5 16:55:54 CEST 2013
> i686 AMD Athlon(tm) 64 X2 Dual Core Processor 5600+ AuthenticAMD
> GNU/Linux
> 
> Gnu C                  4.4.5
> Gnu make               3.82
> binutils               2.22
> util-linux             2.22.2
> mount                  debug
> module-init-tools      12
> e2fsprogs              1.42
> jfsutils               1.1.15
> reiserfsprogs          3.6.21
> xfsprogs               3.1.10
> Linux C Library        2.15
> Dynamic linker (ldd)   2.15
> Procps                 3.3.4
> Net-tools              1.60_p20120127084908
> Kbd                    1.15.3wip
> Sh-utils               8.20
> Modules Loaded
> 
> Connections looking like this on booth sites:
> 
> 11:52:04.634315 IP6 2a00:1828:0:1::10.51808 >
> 2a00:1828:1000:1102::2.80: Flags [S], seq 103067898, win 5760, options
> [mss 1440,sackOK,TS val 232579708 ecr 0,nop,wscale 7], length 0
> 
> 11:52:04.634354 IP6 2a00:1828:1000:1102::2.80 >
> 2a00:1828:0:1::10.51808: Flags [S.], seq 3352491415, ack 103067899, win
> 14280, options [mss 1440,sackOK,TS val 174797959 ecr
> 232579708,nop,wscale 7], length 0 
> 
> 11:52:04.634656 IP6 fe80::92e2:baff:fe00:c120 > 2a00:1828:1000:1102::2:
> ICMP6, redirect, 2a00:1828:0:1::10 to 2a00:1828:0:1::10, length 136
> 
> 11:52:04.634715 IP6 2a00:1828:0:1::10.51808 >
> 2a00:1828:1000:1102::2.80: Flags [.], ack 1, win 45, options
> [nop,nop,TS val 232579708 ecr 174797959], length 0
> 
> 11:52:04.634726 IP6 2a00:1828:1000:1102::2.80 >
> 2a00:1828:0:1::10.51808: Flags [R], seq 3352491416, win 0, length 0
> 
> 11:52:04.635027 IP6 2a00:1828:0:1::10.51808 >
> 2a00:1828:1000:1102::2.80: Flags [P.], seq 1:359, ack 1, win 45,
> options [nop,nop,TS val 232579708 ecr 174797959], length 358
> 
> 11:52:04.635037 IP6 2a00:1828:1000:1102::2.80 >
> 2a00:1828:0:1::10.51808: Flags [R], seq 3352491416, win 0, length 0
> 
> 11:52:04.635071 IP6 fe80::92e2:baff:fe00:c120 > 2a00:1828:1000:1102::2:
> ICMP6, redirect, 2a00:1828:0:1::10 to 2a00:1828:0:1::10, length 112
> 
> 11:52:04.635246 IP6 fe80::92e2:baff:fe00:c120 > 2a00:1828:1000:1102::2:
> ICMP6, redirect, 2a00:1828:0:1::10 to 2a00:1828:0:1::10, length 112
> 
> Kind Regards and keep up the good work! :)
> 
> Tetja Rediske