FreeLists / openbeosnetteam / [openbeosnetteam] Re: PPP API

["Philippe Houdoin" <philippe.houdoin@xxxxxxx>]

Nathan wrote:
> What happens is that you declare yourself, say, ppp/ethernet. The net 
> stack, which keeps a register of all active layers, then tries to 
> attach all ethernet/* devices underneath you, and to attach you to 
> all 
> */ppp devices. In the case of PPP, since the ppp protocol does things 
> itself, pppoe would be something like ppptransport/ethernet, and PPP 
> would be ppp/ppptransport. 

Oh, I see now.
Don't ask, but first time I saw the layer names, I thought of MIME 
string :-)

So, for a TCP connection sent over an ethernet card /dev/net/vt86c100/0 
(that's an example fitting well my home system :-) ) it will give these 
down linked layers:

1) socket[able]/tcp
2) tcp/ip
3) ip/ethernet
4) ethernet/vt86c100(/0?)

where:

1) implement the TCP datagram(s) building and handling
2) implement the TCP datagram encapsulation into a IP frame (and handle 
fragmentation, retries, etc?)
3) implement ethernet framing of a ip datagram
4) implement an ethernet type interface link
 
Am I right?

For input, the Net::Layer::ParentType() give the layer name from which 
we accept (or is it only "expect" here?)
input, like in your sample ppp/pppoe layer, which return ParentType() 
of "ethernet/*"?

Overall, I like this way of auto-assembly of network layers, which 
suppress the protocols/interfaces classic split too.

-Philippe

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