Re: POSTROUTING hooks

[Patrick McHardy <kaber@trash.net>]

Eliot, Wireless and Server Administrator, Great Lakes Internet wrote:
> Where in the kernel's packet delivery process does the POSTROUTING chain
> hook in? 
> 
> I'm trying to figure out how to write a module to allow matching on the
> destination MAC address. From what I have been able to figure out so
> far, it looks like the destination MAC is not actually set until right
> before the packet goes out of the interface. Now, I have not been able
> to find the code that would confirm this, so if anyone can point me to
> the exact position where the destination MAC address is set, that would
> be helpful. However, from what I have been able to observe with logging
> and some quick and dirty modifications to a couple of modules to print
> out some extra debugging info, this appears to be the case. 
> 
> What would it take to modify the Netfilter code to make the POSTROUTING
> chain hook in AFTER the destination MAC is set, but BEFORE it gets sent
> out the interface? 

Still doesn't help, ARP resolution happens after that.