* nsupdate: support server FQDN
Right now, the server has to be specified as an IPv4/IPv6 address. This
adds support for specifing the server as a FQDN as well.
* nsupdate: support GSS-TSIG/Kerberos
Add support for GSS-TSIG (Kerberos) keys to nsupdate. This makes life
easier when working with Windows DNS servers or Bind in a Kerberos
environment.
Inspiration taken from here:
https://github.com/rthalley/dnspython/pull/530#issuecomment-1363265732Closes: #5730
* nsupdate: introduce query helper function
This simplifies the code by moving the protocol checks, etc, into a
single place.
* nsupdate: try all server IP addresses
Change resolve_server() to generate a list of IPv[46] addresses, then
try all of them in a round-robin fashion in query().
* nsupdate: some more cleanups
As suggested in the PR review.
* nsupdate: apply suggestions from code review
Co-authored-by: Felix Fontein <felix@fontein.de>
---------
Co-authored-by: Felix Fontein <felix@fontein.de>
