Bug: If DHCPv4 MAC are used to infer SLAAC and the forth position of
the subnet /64 is 0 (X:X:X:0::/64), then DNS records where malformed.

Signed-off-by: Eric Luehrsen <ericluehrsen@hotmail.com>

- Add domain_forward to permit designated domains to forward instead
  of recurse as listed in resolve.conf.auto from DHCP WAN client
- Update rebind_protection and add rebind_interface to protect IP6
  GLA locally just like RFC 1918 protection
- Rename trigger to trigger_interface with backwards compatability
- Update odhcpd script for efficiency handling many clients

Signed-off-by: Eric Luehrsen <ericluehrsen@hotmail.com>

When using the configuration under "Unbound and odhcpd" in the package's
README.md, the scripts generated a malformed config file for unbound, due
to an "ip route" command giving extra output lines with the string
"anycast" where the awk script expects an address. These are now filtered.

Signed-off-by: Daniel Gimpelevich <daniel@gimpelevich.san-francisco.ca.us>

Enhance the 'control' option to allow using SSL
to connect to the server. Add the 'extended_stats'
option to match 'extended-statistics: yes.'
Document the 'extended_luci' option; it does not
control Unbound, but changes the LuCI tabs.

Signed-off-by: Eric Luehrsen <ericluehrsen@hotmail.com>

procd interface triggers may be busy. Unbound hard restarts will
flush the cache. This might happen frequently depending on how
interface triggers occur.

Change the procd trigger to reduce occurences. Load this trigger
prior to netifd (START=20), but only truly start Unbound from
the trigger rather than immediately in init. Clean up log entries
in scripts after Unbound, NTP, and DNSSEC are established.

Signed-off-by: Eric Luehrsen <ericluehrsen@hotmail.com>

When for example 'package/net/adblock' and DNSSEC vs NTP robustness
is enabled, significant restart thrashing can occur at boot up. DHCP
lease triggers may be occuring at the same time. Unbounds DNS-DHCP
may be incomplete until new DHCP solicit events. Solve this by
leaving a passive but complete host conf file during lease trigger.

Signed-off-by: Eric Luehrsen <ericluehrsen@hotmail.com>

Bug fix dhcp4_slaac6 option was adding to all IP6 routes.
Filtering was added to this process to only include addresses
served from "this dhcp interface."

adblock 2.3.0 file output is now detected and automatically
integrated into Unbound local-zones. adblock deposites its
block site zone-files into /var/lib/unbound. If this is not
desired, then disable adblock or reconfigure to avoid Unbound.

Signed-off-by: Eric Luehrsen <ericluehrsen@hotmail.com>

The UCI for Unbound already links to dnsmasq, but what
if with Unbound, we want to configure a plain dhcp server.
Most servers can call a script for lease events. That
script can then formulate DNS records and load them
with unbound-control (dependency).

The files added here work with OpenWRT/LEDE odhcpd, such
that it can be run alone. They can be used as examples
for any dhcp server. 'odhcpd.sh' is to be called by
odhcpd when a lease event occurs. 'odhcpd.awk' is called
internal to the shell script. The awk script handles
any tricky reformating that may be required.

/etc/config/dhcp
config odhcpd 'odhcpd'
  option leasetrigger '/usr/lib/unbound/odhcpd.sh'

Signed-off-by: Eric Luehrsen <ericluehrsen@hotmail.com>