this implements the server part of mschapv2 with the new
authserver changes.
we also provide AuthInfo for the client now with the
MPPE secret and the authenticator.
this adds new rpc for mschapv2 authentication (21)
deliver the MPPE secret not after the ticket/authenticator
response as cheartext, but include it in the first 128 bit
of the ticket key. and the authenticator in the first 160 bit
of the authenticator random field.
the ::/0 route has the bad side effect of breaking v4 connections
when theres no default route due to v6 mapped v4 addresses. this
might be temporary measure.
windows 7 just drops the default router when it tries to
probe for router reachability but gets a neighbor avertisement
from the router with the router bit clear.
so set the R-flag when sendra is active, which implies that
we are a router.
use OCHAPREPLYLEN instead of sizeof(reply) (no padding).
exit after sending ticket response to force eof as factotum
unconditionally reads tailing secret hash (as of mschap).
the driver doesnt implement multicast filter, but just turns
on promiscuous mode when a multicast address is added. but this
breaks when one actually enables and then disables promiscuous
mode with say, running snoopy.
we have to keep promisc mode active as long as multicast table
is not empty.
broadcast traffic was received back on the wire causing
duplicate address detection to break with dmat proy as
the rewritten broadcasts where observable.
the fix is to just ignore packets from ourselfs received
from the air. devether already handles loopback.
when kernel memory is exhausted, rtl8169replenish() can fail
to plant more receive descriptors and rtl8169receive() would
run over the receive tail and crash on the nil ctlr->rb[x].
rtl8169receive() is called on "Receive Descriptor Unavailable"
and "Packet Underrun" so we will try to replenish descriptors
in the beginning first in case memory was exhausted and memory
is available again and make sure not to run over the tail.
