extending netfilter...plz help Post: 97538

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Top Forums Programming extending netfilter...plz help Post 97538 by Rakesh Ranjan on Tuesday 31st of January 2006 10:02:10 AM

01-31-2006

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extending netfilter...plz help

Hello friends i'm trying to extend iptables to include a target by which we can change the packet type field of a packet.
For this i created a kernel module and a userspace extension.
Now i face the problem that when i try to invoke iptable with the target i created i get an error message saying that "no match/target/chain by that name" but when i do lsmod to show the modules that are loaded my kernel module is shown (that means it is loaded) i also went through userspace extension in iptables made by me but could not locate any problem.
only thing that i could locate was that the error message was coming from libiptc.c (here strange thing was that in libiptc.c in the function that printed error there was a structure which stored the function name where error originally occured, the error no. and msg. Now in my case the function name was shown as NULL so I can't figure out where the error is actually coming from.)

One more related problem, to debug above, in kernel module i gave some kernel messages (which i obviously thought that would be printed out some where as they will b reached) but i'm not able to figure out where that message is going. I checked system log in /var/log/messages but there i could just find one system message that the module has been loaded but not the customized message that i gave. Can someone help me out with that where is my message going.

Oh sorry! I forgot to tell my system description. I'm running redhat 9.0 (kernel 2.4.20) and using iptables 1.2.7a.

Rakesh Ranjan

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LEARN ABOUT CENTOS

tapset::netfilter

tapset::netfilter(3stap)												  tapset::netfilter(3stap)

NAME

       tapset::netfilter - systemtap netfilter tapset

DESCRIPTION

       netfilter.ip.pre_routing
	      Called before an IP packet is routed

	       See probe::netfilter.ip.pre_routing(3stap)
	       for details.

       netfilter.ip.local_in
	      Called on an incoming IP packet addressed to the local computer

	       See probe::netfilter.ip.local_in(3stap)
	       for details.

       netfilter.ip.forward
	      Called on an incoming IP packet addressed to some other computer

	       See probe::netfilter.ip.forward(3stap)
	       for details.

       netfilter.ip.local_out
	      Called on an outgoing IP packet

	       See probe::netfilter.ip.local_out(3stap)
	       for details.

       netfilter.ip.post_routing
	      Called immediately before an outgoing IP packet leaves the computer

	       See probe::netfilter.ip.post_routing(3stap)
	       for details.

       netfilter.bridge.local_in
	      Called on a bridging packet destined for the local computer

	       See probe::netfilter.bridge.local_in(3stap)
	       for details.

       netfilter.bridge.forward
	      Called on an incoming bridging packet destined for some other computer

	       See probe::netfilter.bridge.forward(3stap)
	       for details.

       netfilter.bridge.local_out
	      Called on a bridging packet coming from a local process

	       See probe::netfilter.bridge.local_out(3stap)
	       for details.

SEE ALSO

	    probe::netfilter.ip.pre_routing(3stap),	     probe::netfilter.ip.local_in(3stap),	   probe::netfilter.ip.forward(3stap),
       probe::netfilter.ip.local_out(3stap),		probe::netfilter.ip.post_routing(3stap),	    probe::netfilter.arp.in(3stap),
       probe::netfilter.arp.out(3stap), 	   probe::netfilter.arp.forward(3stap), 	  probe::netfilter.bridge.pre_routing(3stap),
       probe::netfilter.bridge.local_in(3stap),       probe::netfilter.bridge.forward(3stap),	     probe::netfilter.bridge.local_out(3stap),
       probe::netfilter.bridge.post_routing(3stap),  stap(1), stapprobes(3stap)

IBM
									---						  tapset::netfilter(3stap)