Subject: Re: dev->hard_header ?

From: Ben Greear <[email-masked]>
Date: Tue, 19 Nov 2002 21:06:01 -0800

Seong Moon wrote:
> In Layer 3 Protocols(eg. IP, IPv6, ...),
> they calls dev_queue_xmit() to send their data.
> 
> Before calling dev_queue_xmit(),
> does the layer 3 protocols always call dev->hard_header ?
> 
> Actually, I'm not sure when dev->hard_header is called.
> 
> I think dev->hard_start_xmit can include the part of dev->hard_header.
> Why did the developer seperate the header building and sending frame
> fucntion ?

It's not always called, this way user-space (or other parts of the kernel)
can build the headers if desired.  This at least works for ethernet and
VLAN interfaces.

Ben

> thanks in advance.

-- 
Ben Greear <[email-masked]>       <Ben_Greear AT excite.com>
President of Candela Technologies Inc      http://www.candelatech.com
ScryMUD:  http://scry.wanfear.com     http://scry.wanfear.com/~greear