Re: Packet Injection within netfilter module

[Ben Gardiner <bengardiner@nanometrics.ca>]

On Tue, Apr 13, 2010 at 4:13 AM, Ali Hamidi <ali.hamidi759@gmail.com> wrote:
> Is there any way to inject a newly created packet based on the
> captured packet inside a netfilter hook call back function?
> My Goal is to capture a packet change compress its tcp payload and
> send it. i read ipcomp.c and i used its source. when i change skb size
> (like len) and tail pointer kernel hangs. maybe the way to do, is to
> create a new packet based on captured packet and ask kernel to send
> it. I just don't know how to ask kernel to send a newly created
> packet?

I'm not sure this will work -- it's just an idea that comes to mind.
Perhaps you could use TUN to inject a newly created packet from a
userspace application?

packet ---> netfilter rule with userspace target ---> userspace
payload compressor ---> /dev/tunX

-- 
Ben Gardiner
Nanometrics Inc.
+1 (613) 592-6776 x239
http://www.nanometrics.ca