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[Firewall] PCC internals

Posted: Mon Feb 21, 2011 10:46 pm
by exa
Hello,

is there some good documentation about the PCC classifier? I'd like to tune it a little, and probably be able to understand completely how it works (what is the hash function, to be exact), so any documentation on given topic would be great. Is there at least some simple info how is PCC match rewritten into underlying linux matches?

Thanks
-mk

Re: [Firewall] PCC internals

Posted: Mon Feb 21, 2011 10:58 pm
by Feklar

Re: [Firewall] PCC internals

Posted: Tue Feb 22, 2011 10:13 am
by exa
Well, the first document actually lists the hash function as simple |-ing the fields together. I wonder what the | operation is? to me it seems like XOR, but that wouldn't actually be 'hashing', afaik..

Thanks
-mk

Re: [Firewall] PCC internals

Posted: Tue Feb 22, 2011 4:03 pm
by fewi
The | in that case is manual notation. The algorithm is unknown. It is known that it also includes a random seed generated at boot time, so different values are generated after each boot given the same input. I strongly suspect only the official support channel can tell you the answer you are after.

Re: [Firewall] PCC internals

Posted: Tue Feb 22, 2011 8:42 pm
by exa
Yeah, I was kindof afraid of that. Gonna try it though, knowing the exact function would spare me a whole lot of work.