ng_one2many(4) improvement.

Hello.

I've added new link failure detection algorithm.
It works by scanning connected interfaces: if interface is up, it will be
used and if it is down it will be ignored.
Still link 'one' have to be always active.

It can be configured in this way:

	ngctl msg fxp0:upper setconfig "{ xmitAlg=1 failAlg=2 timeout=5 }"

where fxp0 is our 'one' interface.
5 seconds interval will be used to scan interfaces.

Patch is avaliable at:

	http://garage.freebsd.pl/patches/netgraph_one2many.patch

-- 
Pawel Jakub Dawidek                       pawel_at_dawidek.net
UNIX Systems Programmer/Administrator     http://garage.freebsd.pl
Am I Evil? Yes, I Am!                     http://cerber.sourceforge.net