I've just completed porting my IP packet filter which was originally
written for SunOS4 to NetBSD-current.  It is (or should be!) architecture
independant, but before it will load, requires the provided patches be
applied to /usr/src/sys/netinet/ip_{in,out}put.c.  It comes complete with
man pages and docs on how to (ab)use it.

I'm not sure if it was just me or not, but does modload _really_ look for
_xxxinit() or is this a NetBSD-sparc peculiarity ? (Note that on SunOS4.1.x,
xxxinit() is required in the module for it to load).

Anyway, it does the same stuff for loading into NetBSD (ie creates its own
device in /dev - so MAKEDEV isn't required - and allocates its own cdevsw
slot) as it does for SunOS4 now.

If you'd like to check it out, you can ftp as:

coombs.anu.edu.au:/pub/net/kernel/ip_fil2.5b.tar.Z

(still beta)

Although this isn't suitable as a simple example of a LKM device, does
anyone have one that could slot in under /usr/share/lkm or want to write
one that does ?

darren