Subject: Re: How to fix packet destination address before RFC1122 dropping
To: Paulo Matias <syscoder@gmail.com>
From: Darren Reed <darrenr@netbsd.org>
List: tech-net
Date: 07/07/2007 01:56:12
Paulo Matias wrote:
>>
>> I just think it would be difficult to convince anyone that such
>> a change is suitable for all.
>
> Sure. It's the reason I asked if there was a solution that could be
> done without changing the code.
>
> So I think the best solution will be to develop a little program for
> capturing the packets via bpf, modifying them, and sending them to a
> TUN interface.
>
> Unfortunately, changing the kernel code is not a good choice in my
> case, because I'm developing a set of scripts for helping users of
> these mobile phones under BSD and Linux, and I must make it the
> simplest possible to the end-user.
>
> Thanks, now I know the solution I thought about (using bpf) was not a
> hack, but the way out for doing it under BSD solid TCP/IP stack.

There was one other change that crossed my mind:
introduce a sysctl to turn off loopback filtering at that point,
something like a
net.inet.ip.dropforeignloopback
which defaults to 1 but i'm not sure it is really that attractive.

Darren