[TEST/REVIEW] ng_ipfw: node to glue together ipfw(4) and netgraph(4)

[Brooks Davis]

On Thu, Jan 20, 2005 at 04:45:53PM +0300, Gleb Smirnoff wrote:
>   Julian,
> 
> On Wed, Jan 19, 2005 at 01:32:35AM -0800, Julian Elischer wrote:
> J> I'm not sure they do two different things..  Each represents a place to 
> J> send packets.
> J> If each active divert socket number had a pointer to the module to which it
> J> was attached then  you could divert to either in-kernel netgraph targets or
> J> to userland socket based targets.  Currently of you divert to a divert
> J> 'port number' and nothing is attached to it, the packet is dropped.
> J> If a divert socket is attached to it, it is sent ot teh socket.
> J> I would just suggest that is not a great leap of imagination that
> J> attaching to a hook named 3245 would attach a netgrpah hook to the ipfw
> J> code in the sam enamespace as the divert portnumber, and that a
> J> subsequent attempt to attach a divert socket to that port number woild
> J> fail. The packets diverted there would simply go to the netgraph hook
> J> instead of going to a socket or being dropped.
> 
> Well, I've considered this. We are going to have these negatives with this change:
> 
> 1) require divert loaded/compiled, when we are going to work with a completely
>    different thing.
> 2) Acquire & drop lock on divert pcb info for each packet going into netgraph.
> 3) Extensively hack divert_packet()... Let me explain. The place where we can tell
> whether we have a socket diversion or a netgraph diversion, is at the very end
> of divert_packet(). Before this place many things are done, which does not apply
> to a netgraph diversion.
> This hacking may bring bugs into divert infrastructure, and add extra CPU cycles
> for case of netgraph forwarding. I think saving one keyword for ipfw2 doesn't
> worth this hacks.

I think the code should be committed more or less as is.  I think the
netgraph and divert features are relatively orthogonal.

-- Brooks

-- 
Any statement of the form "X is the one, true Y" is FALSE.
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