Re: 2.2: skb->mac.ethernet always valid pointer?

kuznet@ms2.inr.ac.ru
Sat, 25 Sep 1999 22:59:58 +0400 (MSK DST)


Hello!

> Someone wants to log mac addresses in ipchains, which makes
> sense.

F.e. me want. 8)

> The problem is that the packet could be a locally generated
> one (output chain): can I simply dump skb->mac.ethernet.h_source or is
> this not always a valid ptr? I don't care about dumping junk, just
> about crashing the kernel.

It is guaranteed. You may just dump all the area between
mac.raw and skb->data, if these pointers do not coincide.
It is not a good idea to parse and interpert it in kernel though.

What's about dumping in output chain... It is non-sense.
I am sorry, it is better not to make this. This area will replicate
addresses of some earlier allocated packet with 100% of probability
and you may difame innocent people.

Alexey

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/