>>>>> "Andrew" == Andrew Brown <atatat@atatdot.net> writes:
    >> As for the ether_input() interface, what you really want is something
    >> tun(4)-like but that works at the Ethernet level rather than the IP
    >> level.  You could probably start by copying if_tun.c and hacking on it
    >> to use ether_input rather than enqueueing stuff on ipintrq....

    Andrew> take a look at tap(4) under freebsd.  it's incredibly similar to
    Andrew> tun(4), but does "ethernet stuff" in a way that i have i've not yet
    Andrew> seen to be useful.  maybe it will do what you want.  ought to be
    Andrew> pretty easy to port over as well.

  It becomes useful when you start building various kinds of virtual machines 
or virtual network stacks in userspace.

  One example that I hope we might eventually emulate is "user-mode-linux" -
one compiles the kernel to run as a series of processes. This has major win
for doing network protocol work... Much lighter weight than Vmware type
things.
  (I want to do this both for doing NetBSD protocol work and for doing Linux
protocol work on my Netbsd notebook...)

]       ON HUMILITY: to err is human. To moo, bovine.           |  firewalls  [
]   Michael Richardson, Sandelman Software Works, Ottawa, ON    |net architect[
] mcr@sandelman.ottawa.on.ca http://www.sandelman.ottawa.on.ca/ |device driver[
] panic("Just another NetBSD/notebook using, kernel hacking, security guy");  [