RE: How to take over TCP connection from userspace process?

["yangrunhua" <yangrunhua@njupt.edu.cn>]

But sendfile() system call could not support copying from socket to socket, and only transfer in one direction.

What I need is: after I authenticated TCP connection A(host A connected to me) and TCP connection B(host B connected to me), then let what host A send (through TCP connection A)directly forward to host B(through TCP connection B) in the kernel ,meanwhile, what host B send directly forward to host A in the kernel.

That's much like MSN Messenger Server's relaying webcam video stream between two peers after authenticated them. I want to do this relay in kernel space and auth in the userspace. It's much like NGN softswitch's theory: control and auth separate from transfer.

That's much useful functionality. Can netfilter/iptables help this? done this by writing a new target or something?

Thanks,
	Runhua Yang


-----Original Message-----
From: Harald Welte [mailto:laforge@netfilter.org] 
Sent: Tuesday, October 21, 2003 9:47 PM
To: yangrunhua
Cc: netfilter-devel@lists.netfilter.org
Subject: Re: How to take over TCP connection from userspace process?

On Tue, Oct 21, 2003 at 03:33:22PM +0800, yangrunhua wrote:
> Hi all,
> 	With the help of netfilter/iptables, is there any way to high-speed forwarding between 2 already-connected TCP connections in the kernel?

I don't see how this could be related to netfilter/iptables at all.
The normal sendfile() systemcall may be helpful to you.

> 	Thanks,
> 				Runhua Yang

-- 
- Harald Welte <laforge@netfilter.org>             http://www.netfilter.org/
============================================================================
  "Fragmentation is like classful addressing -- an interesting early
   architectural error that shows how much experimentation was going
   on while IP was being designed."                    -- Paul Vixie