HEADSUP: OpenBSD dhclient incoming

I'm about to start importing the OpenBSD dhclient and required
support in /etc.  I will unhook dhclient from the build while I work so
there shouldn't be much breakage for most people.

The OpenBSD version is a cut down version of the ISC client.  The major
changes are that there is one process per interface (actually two since
it does priv-sep) and that the processes automatically exit when the link
goes down.  This means that dhclient needs to be started when the
interface gets carrier.  In OpenBSD this is handled by ifstated.  I've
chosen to advertise link state events to devd and handle it there
instead.

Since the interface configuration process had to change to accommodate
this, I've taken the opportunity to streamline it.  There are now less
paths by which and interface will be configured.  First,
/etc/rc.d/dhclient is no longer a start script and simply exists to
start and stop individual dhclients.  Second, /etc/rc.d/netif now
handles both DHCP and non-DHCP interfaces.  As a bonus, it can handle
interface which are both so the following is a valid configuration:

ifconfig_fxp0="DHCP media 100baseTX"

The final big change is the deletion of most of /etc/pccard_ether.  It
now calls /etc/rc.d/netif start <if> to handle 90% of it's work.  Some
ipv6 and routing configuration for non-DHCP interfaces is still there,
but most of the code that duplicated code in /etc/network.subr is gone.
In the process a few things have changed.  First, extra arguments are
now an error and are not passed to ifconfig.  Second the pccard_ifconfig
variable is only used as a default value for interfaces that are
on the removable_interfaces list, but do not have an ifconfig_<if>
variable.  Third, interfaces must be on the removable_interfaces list
for pccard_ether to work.

Partial support for WPA is included and I'm working with Sam to finish
it for the release.

I'll send an all clear once I'm fairly confident things are working
again.

-- Brooks

-- 
Any statement of the form "X is the one, true Y" is FALSE.
PGP fingerprint 655D 519C 26A7 82E7 2529  9BF0 5D8E 8BE9 F238 1AD4