we now update /net/ndb with the following information gathered
from router advertisements (rfc6106 and plan9 specific options):
- recursive dns servers (option 25, ndb: dns=)
- dns search list (option 31, ndb: dnsdomain=)
- plan9 fileserver (option 250, ndb: fs=)
- plan9 authserver (option 251, ndb: auth=)
note the plan9 specific options can be disabled with the -G flag.
for ndbconfig (-N flag), we now collect all ip addresses in ndb
belonging to the devices mac address and configue them all. v6
addresses are getting added when a link local address exists
or the -6 flag has been specified to automatically configure one.
move the dhcp code in its own dhcp.c file and make symbols static
that are not used across modules.
we have to maintain the ->line chain for ndbreorder() to work, so add
a little helper: ndbline() which replicates the ->entry chain and links
the last tuple to the first; makeing the whole list into a single line.
there appears to be confusion about the refresh flag of arpenter().
when we get an arp reply, it makes more sense to just refresh
waiting/existing entries instead creating a new one as we do not
know if we are going to communicate with the remote host in the future.
when we see an arp request for ourselfs however, we want to always
enter the senders address into the arp cache as it is likely the sender
attempts to communicate with us and with the arp entry, we can reply
immidiately.
reject senders from multicast/broadcast mac addresses. thats just silly.
we can get rid of the multicast/broadcast ip checks in ethermedium and
do it in arpenter() instead, checking the route type for the target to
see if its a non unicast target.
enforce strict separation of interface's arp entries by passing a
rlock'd ifc explicitely to arpenter, which we compare against the route
target interface. this makes sure arp/ndp replies only affect entries for
the receiving interface.
handle neighbor solicitation retransmission in nbsendsol() only. that is,
both ethermedium and the rxmitproc just call nbsendsol() which maintains
the timers and counters and handles the rotation on the re-transmission
chain.
no need to rlock ifc in targetttype() as we are called from icmpiput6(),
which the ifc rlocked.
for icmpadvise, the lport, destination *AND* source have to match.
a connection gets a packet when the packets destination matches the source
*OR* the packets source matches the destination.
v4lookup() and v6lookup() do not acquire the routelock, so it is
possible to hit routes that are on the freelist. to detect these,
we set ref to 0 and check for this case, avoiding overriding the ifc.
re-evaluate routes when the ifcid on the route hint doesnt match.
