how to delay and drop the packet

sonika_singhi · 03-30-2005, 01:25 PM

i want to manipulate some of the fields of the packet at ip-layer at Gateway machine and want to send the manipulated packet to the
destination lying in some other network

so i want to delay and drop those packets.
could anyone tell pls, how to do that through C program
using any inbuilt functions

-----------thanx--------------------------------

fr_laz · 03-30-2005, 02:51 PM

Hi,

I've never done networking through C programmation... but I've just seen an iptables target that could help if you agree to do a part of this in shell script.

There's a target called u32 which seems to enable you to match packets given any bit pattern in the header (http://www.netfilter.org/documentat...ions-HOWTO.html)... thus you should be able redirect the packets you've previously modified.

cereal83 · 03-30-2005, 02:52 PM

Bad link, fr_laz

sonika_singhi · 04-02-2005, 11:50 AM

seriously i need some accurate soluttion for my previous
problem,
the link is not working.
If anyone know any c code for delaying and dropping packets at gateway
pls let me know

fr_laz · 04-02-2005, 04:55 PM

Sorry ! Here it is :
http://www.netfilter.org/documentati...ons-HOWTO.html

but u32 filters may only solve a part of your problem : I don't think you can modify packets, only match them