Re: [PATCH 8/8] [NETFILTER]: xt_length match, revision 1

[Patrick McHardy <kaber@trash.net>]

Jan Engelhardt wrote:
> On Tuesday 2008-04-08 17:28, Patrick McHardy wrote:
>> Jan Engelhardt wrote:
>>> Introduce xt_length match revision 1. It adds support for layer-4,
>>> layer-5 and layer-7 length matching. It is much easier than writing
>>> up the according xt_u32 magic.
>>>
>>> This can be used for packet scheduling; specific example are online
>>> games where all data is transferred over the same port, but the
>>> regular gameplay has a characteristically lower packet size than bulk
>>> downloads of game maps. (Tested with Unreal Tournament 99.)
>> I'll let this sit on the list for a few more days in case
>> someone else has comments. I'm personally not a huge fan
>> of bloating this length module like this. Perhaps something
>> more minimalistic would also do the trick?
> 
> Have something special in mind?
> 

In my opinion all the kernel should needs to be able to do
is to deal with variable length headers, everything else can
be calculated by userspace(/the user).

So for example if you can match on the IP payload length,
you *know* the UDP data length is that value - 8.

Whats that SCTP thing about?