Jan Engelhardt wrote:
> On Dec 19 2006 12:51, Patrick McHardy wrote:
>
>>>Reusing code is a good idea, and I would like to do so from my
>>>match modules. netfilter already provides a xt_request_find_target() but
>>>an xt_request_find_match() does not yet exist. This patch adds it.
>>
>>Why does your match module needs to lookup other matches?
>
>
> To use them?
>
> I did not want to write
>
>
> some_xt_target() {
> if(skb->nh.iph->protocol == IPPROTO_TCP)
> do_this();
> else
> do_that();
> }
I don't think
xt_request_find_match(match->family, "tcp", 0)->match(lots of arguments)
is better than a simple comparison. Besides that the tcp match itself
expects that the protocol match already checked for IPPROTO_TCP, so
you'd still have to do it.
> since the xt_tcpudp module provides far more checks than just the protocol
> (TCP/UDP), like
>
> /* To quote Alan:
>
> Don't allow a fragment of TCP 8 bytes in. Nobody normal
> causes this. Its a cracker trying to break in by doing a
> flag overwrite to pass the direction checks.
> */
This check makes sure the flags are not overwritten _after you
matched on them_. It doesn't matter at all if you're only
interested in the protocol since the user didn't tell you to care.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
