liransgarage at gmail
Jul 22, 2007, 5:02 AM
Post #3 of 3
Re: An ip_conntrack / nat problem with kernel 2.4.17_mvl21
[In reply to]
Thanks for your attention and reply.
I haven't checked 2.4.17 but I doubt it's an actual problem with that
kernel version as this error is a show stopper and I doubt it would
have been released and so the only conclusion I have right now is that
TI guys have modified some code there
and screwed up things in the middle.
I have tried disabling some config options regarding their changes and other
things but still not much luck.
I really need something to go with here...
If you can help in any way I'd very much appreciate that.
On 7/20/07, Yasuyuki KOZAKAI <yasuyuki.kozakai [at] toshiba> wrote:
> From: "liran tal" <liransgarage [at] gmail>
> Date: Fri, 20 Jul 2007 10:50:24 +0200
> > Hey everyone,
> > I'm using a version of the 2.4.17_mvl21 kernel (from MontaVista
> > originally) which was modified by Texas Instruments for their
> > additions of some hardware.
> > The problem I'm facing is this:
> > [computer A: 172.16.0.33] --> [LAN IP: 172.16.0.1 ...linuxbox... WAN
> > IP 172.17.1.4] -->[computer B: 172.17.1.44]
> > The situation is that a computer on the LAN side of the linux box
> > running that kernel with
> > an IP of say 172.16.0.33 (computer A) pings a computer behind the WAN
> > IP, say computer B with IP of 172.17.1.44
> > isn't getting an reply.
> > When I started wireshark on computer B to see what's going on I saw
> > that it receives icmp echo requests
> > from the IP address 172.16.0.33 and tries to reply back which is
> > ofcourse totally wrong as it's
> > unreachable and what should've happened is that it was supposed to see
> > a request from the WAN IP
> > 172.17.1.4 and reply to that.
> > I can say that anything related to the actual configuration of the
> > NAT/Masquerading information
> > is irrelevant since it is working with a previous kernel version just fine.
> > That previous version we had of this kernel had a problem with
> > ip_conntrack or basically a nat problem and the guy who was dealing
> > with it before me "solved" it by overwriting some files from kernel
> > 2.4.20 vanilla. Files like net/ipv4/netfilter/*
> > include/linux/netfilter_arp/* and include/linux/netfilter_ipv4 if I
> > can remember correctly.
> > Anyway, I can not do the same procedure with this new version of the
> > kernel they gave us because the guys at TI inserted some of their own
> > code into the networking stack which seems about dealing with qos and
> > some files have includes to ti_qos.h etc
> > I'm really looking for a lead on which files to look at exactly and what
> > should I be exactly looking for?
> > If anyone has any idea how to approach this or any leads
> > I'll appreciate that very much.
> I have no idea. But if I was you, I would try main line kernel 2.4.17 on
> other machine if thre is no difference between them (maybe what you should
> see are ip_conntrack_*.c and ip_nat_*.c in net/ipv4/netfilter), look for
> changes at following if the kernel 2.4.17 has same problem,
> and try related fix. If the recent kernel (2.4.33) had same
> problem, I would make a patch to fix or report it on this list.
> We don't usually take care of distro's customized kernel, so I recommend
> to ask Montavista guys or TI guys about details.
> -- Yasuyuki Kozakai