Re: Generating pseudo-packets with netfilter

[Dai MIKURUBE <dmikurube@acm.org>]

Hi,

I make a supplementary explanation.


Finally, my purpose is to make "Pseudo 3-Way Handshake".

At first, a user process create a socket (with socket())
and make it TCP_LISTEN (with listen()).

Next, I'd like to make it's status CONNECTED without any
external computers for some reason. In order to do this,
it's necessary that the Linux Kernel believes a SYN packet
has come. So, of cource, to handle a SYN+ACK pakcet and to
reply an ACK packet are required.


If netfilter cannot generate packets out of nothing,
I think to take the following way:

1. My module call netif_receive_skb() directly to send a SYN packet.
2. Kernel replys a SYN+ACK packet,
     and my module catches it with netfilter.
3. My module DROPs the packet,
     and my module replys an ACK packet with netif_receive_skb().

But it seems to be a little hard. I'm happy if it can be done
with netfilter.

-- 
Dai MIKURUBE
    dmikurube@acm.org