Re: dev->hard_header ?

[Ben Greear <greearb@xxxxxxxxxxxxxxx>]

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 <greearb@xxxxxxxxxxxxxxx>       <Ben_Greear AT excite.com>
President of Candela Technologies Inc      http://www.candelatech.com
ScryMUD:  http://scry.wanfear.com     http://scry.wanfear.com/~greear