Skip site navigation (1)Skip section navigation (2)
Date:      Wed, 19 Mar 2008 08:50:03 GMT
From:      Vadim Goncharov <vadim_nuclight@mail.ru>
To:        freebsd-ipfw@FreeBSD.org
Subject:   Re: kern/121807: Sugestion: TCP and UDP port_table in ipfw
Message-ID:  <200803190850.m2J8o3Pw081587@freefall.freebsd.org>

Next in thread | Raw E-Mail | Index | Archive | Help
The following reply was made to PR kern/121807; it has been noted by GNATS.

From: Vadim Goncharov <vadim_nuclight@mail.ru>
To: Joao Rocha Braga Filho <goffredo@gmail.com>
Cc: bug-followup@freebsd.org
Subject: Re: kern/121807: Sugestion: TCP and UDP port_table in ipfw
Date: Wed, 19 Mar 2008 14:47:01 +0600

 Hi Joao Rocha Braga Filho! 
 
 On Mon, 17 Mar 2008 20:15:12 GMT; Joao Rocha Braga Filho <goffredo@gmail.com> wrote:
 
 > Why not exist a TCP/UDP port_table for IPFW? It can solve 30 itens limit in ipfw rule. It is good to use in QoS.
 > Example
 > ipfw add allow { tcp or udp } from any port_table(10) to any
 > ipfw port_table 10 add 20,21,25,110,443,993,995,1025-65535
 > # Deny bad ports
 > ipfw add deny { tcp or udp } from any to any port_table(11)
 > ipfw port_table 11 add 135,137-139,445
 > ipfw add queue 100 udp from any port_table(20) to any
 > ipfw port_table(20) add 123,53
 
 For what puprose should it _really_ serve? Limit-upping? Per-packet speed
 optimisation? More handy config preapring? Should that tables serve as
 a collection-only, or do have tableargs, and for what practical purpose that
 tableargs would be useful?
 
 If it is simply annoying to put long list in config several times, then it is
 correctly solved by shell vars:
 good_ports="20,21,25,110,443,993,995,1025-65535"
 
 ipfw add allow { tcp or udp } from any $good_ports to any
 ipfw add allow { tcp or udp } from ant to $my_server $good_ports
 
 If you care about both value-repeating, limit of 30 items and slightly about
 speed of packet processing, then you'd better classify your traffic with
 or-blocks on start of ruleset with tags:
 
 ipfw add 1 count tag 1 { src-port 20,21,25,110,443,993,995,1025-65535  \
      or src-port 1,2,3,4,5,6,7,8,9,10,11,12,13,...long-list2...,29,30  \
      or src-port ...list3... } // can have up to 8 full 30-port blocks per rule
 ipfw add 2 count tag 2 dst-port 135,137-139,445 // and so on
 
 Packet can have more than one tag at a time, so then you can write like:
 
 ipfw add queue 100 udp from any to any tagged 3
 ipfw add allow { tcp or udp } from any to any tagged 1,2
 
 
 And if your suggested port table is concerned on a per-packet performance, like
 our IP tables do, then how do you suggest it to be implemented in-kernel?
 Current tables for IP are radix trees, they consume a lot of kernel memory
 (which is a scarce resource) and process in term of mask - but it is not
 handy to specify ports in form like "128/8". And any form of tree will consume
 to a lot of memory per entry.
 
 It can be thought as a bit set, one bit for every port, very fast, but will
 consume 8K per one table - 1 meg for 128 such tables, unacceptable, again.
 
 So, I think it is best to use tags for your purposes.
 
 -- 
 WBR, Vadim Goncharov. ICQ#166852181       mailto:vadim_nuclight@mail.ru
 [Moderator of RU.ANTI-ECOLOGY][FreeBSD][http://antigreen.org][LJ:/nuclight]



Want to link to this message? Use this URL: <http://docs.FreeBSD.org/cgi/mid.cgi?200803190850.m2J8o3Pw081587>