Re: [RFC] ematch API, u32 ematch, nbyte ematch, basic classifier
From: jamal <hidden>
Date: 2005-01-05 03:12:08
On Tue, 2005-01-04 at 17:36, Thomas Graf wrote:
* TCF_EM_SIMPLE flag which marks an ematch config as simple, meaning that the data consists of a u32 value.
This is 1 of 2 parts i think thats still an issue; otherwise looks very good. Why do i need to signal something as simple? AND why does it have to be 32 bit type - what edge does that give you? I should be able to specify a struct with two 32 bits and encap it in a TLV and the classifier can treat it the same way - it knows the type and length - thats sufficient to create, destroy and dump. The other issue is still on the ematch/match interleaving i.e i should be able to say something along the lines: //simple slammer-worm or code-red ACL detector rule //using u32 classifier and ematches (match ip protocol udp port 1434 AND ematch packetlen minsize 404 maxsize 404) OR (match ip protocol tcp http AND ematch urlscanner "*.ida") action ipt -j ULOG "Virus detected and dropped" action drop Not a very good example - but you can see how powerfull this is when you can quickly use a string scanner such as the one you have as an ematch while maintaining u32 as is. cheers, jamal