Date: Fri, 7 Dec 2001 19:44:49 +0100
From: salinarl <Lanfranco.Salinari@icn.siemens.it>
To: linux-kernel@vger.kernel.org
Subject: Question about sniffers and linux
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Sender: linux-kernel-owner@vger.kernel.org

Hello to everyone,
I am new to kernel internals, and I would like to know how can a sniffer
read whole packets, I mean including the link layer header. In the receive
path, this happens, I think,  in the net_rx_action(), but in the transmit
path?
I know that there is a function called dev_queue_xmit_nit() for this, but
how can a driver add a link layer header to a packet before this function
gets called? The hard_start_xmit() of the driver is, in fact, called after
the dev_queue_xmit_nit(), (in the function dev_queue_xmit() ).
I think I'm missing something important about the subject, but I hope someone 
will answer me, anyway.
Thank you in advance,

Lanfranco

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