Rather than deleting the NSE from memory, we simply mark it as non-persistent.
This makes sure that there are no invalid references (e.g. from gbprox_peer)
to the gprs_nsvc structure, but at the same time ensures it will no longer
be stored as part of writing the config file.
Using "end" you can always return to the "enable" level, and from
there the "show" commands are available. So no more need for
exit/exit/exit/exit/disable.
In the previous code we used a static fake_nsvc structure in
case we needed to send a message to an unknown NSVC for which
we don't have a real 'struct nsvc'. However, since we now have
a rate_ctr_group hanging off the nsvc, the fake structure didn't
have that.
So now we keep a nsi->unknown_nsvc around to be used whenever
we need a nsvc but don't have a real one. The gprs_ns_vty.c
code explicitly does not list that NSVC in 'show ns'
Every NS-VC now has a set of counters for incoming and outgoing
number of packets and bytes.
We also split the VTY part of the gprs_ns.c implementation into gprs_ns_vty.c
to make sure the protocol can actually be used without the VTY code being
present.
Harald Welte