resolved: remove configuration knobs for mDNS until it's ready These bits were intenionally left out while mDNS is under development. Remove the exposed knobs and man page entries again until this is settled.

resolved,networkd: add a per-interface DNSSEC setting This adds a DNSSEC= setting to .network files, and makes resolved honour them.

resolved: make MulticastDNS support configurable in resolved.conf The option is already there, but wasn't exported in the configuration file so far. Fix that.

resolved,networkd: unify ResolveSupport enum networkd previously knew an enum "ResolveSupport" for configuring per-interface LLMNR support, resolved had a similar enum just called "Support", with the same value and similar pasers. Unify this, call the enum ResolveSupport, and port both daemons to it.

resolved: introduce a dnssec_mode setting per scope The setting controls which kind of DNSSEC validation is done: none at all, trusting the AD bit, or client-side validation. For now, no validation is implemented, hence the setting doesn't do much yet, except of toggling the CD bit in the generated messages if full client-side validation is requested.

resolved: add a generic DnsSearchDomain concept With this change, we add a new object to resolved, "DnsSearchDomain=" which wraps a search domain. This is then used to introduce a global search domain list, in addition to the existing per-link search domain list which is reword to make use of this new object too. This is preparation for implement proper unicast DNS search domain support.

resolved: unify code for parsing dns server information Let's use the same parser when parsing dns server information from /etc/resolv.conf and our native configuration file. Also, move all code that manages lists of dns servers to a single place. resolved-dns-server.c

resolved: beef up DNS server configuration logic We now maintain two lists of DNS servers: system servers and fallback servers. system servers are used in combination with any per-link servers. fallback servers are only used if there are no system servers or per-link servers configured. The system server list is supposed to be populated from a foreign tool's /etc/resolv.conf (not implemented yet). Also adds a configuration switch for LLMNR, that allows configuring whether LLMNR shall be used simply for resolving or also for responding.

resolved: add a DNS client stub resolver Let's turn resolved into a something truly useful: a fully asynchronous DNS stub resolver that subscribes to network changes. (More to come: caching, LLMNR, mDNS/DNS-SD, DNSSEC, IDN, NSS module)

resolved: add daemon to manage resolv.conf Also remove the equivalent functionality from networkd.