When avahi-daemon is avaibale, reading data from its cache help ctrld
populate the mdns data with already known services within local network,
allowing discover client info more quickly.
The default gateway is usually the DNS server in normal home network
setup for most users. However, there's case that it is not, causing
discover ptr failed.
This commit add discover_ptr_endpoints config parameter, so users can
define what DNS nameservers will be used.
So it won't spam ctrld log unnecessary, prevent confusion. While at it,
also change the log level from Warn to Info, since this error is not
actionable by the user.
VPN clients often have empty MAC address, because they come from virtual
network interface. However, there's other setup/devices also create
virtual interface, but is not VPN.
Changing source of those clients to empty to prevent confustion in
clients list command output.
In case the resolver could not reach nameserver, ptr discover should
only print error message once, then stop doing the query until the
nameserver is reachable. This would prevent ptr discover from flooding
ctrld log with a lot of duplicated messages.
So ctrld can record the raw/original client IP instead of looking up
from MAC to IP, which may not the right choice in some network setup
like using wireguard/vpn on Merlin router.
The only reason that forces ctrld to depend on vyatta-dhcpd service on
EdgeOS is allowing ctrld to watch lease files properly, because those
files may not be created at the time client info table initialized.
However, on some EdgeOS version, vyatta-dhcpd could not start with an
empty config file, causing restart loop itself, flooding systemd log,
making the router run out of memory.
To fix this, instead of depending on vyatta-dhcpd, we should just watch
for lease files creation, then adding them to watch list.
While at it, also making ctrld starts after nss-lookup, ensuring we have
a working DNS before starting ctrld.
- Watch more events for lease file changes
- Improving network up detection by using bootstrap IPv6 along side
IPv4 one.
- Emitting log to notice user that ctrld is starting.
- Using systemd wrapper to provide correct status.
- Restoring DNS on stop on Windows.
