Intercepting a packet, changing it and re-injecting into the network

[Fabrício Barros Cabral]

Hello everybody!

I'm developing a network application which needs *to intercept* a packet
(not just *copy* a packet, like libpcap does), move this packet into my
application (userland), do some checking in the packet and according
with some heuristics, the application may change the payload and
re-inject the modified packet into the network. Note that sometimes,
I'll change the payload, drop the packet or just let it go.

So, how can a I do that in FreeBSD? I can use 6.1, 7.1, any version.

Thanks in advance,

--fx


		
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