// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package dns

import (
	"inet.af/netaddr"
)

// Config is a DNS configuration.
type Config struct {
	// DefaultResolvers are the DNS resolvers to use for DNS names
	// which aren't covered by more specific per-domain routes below.
	// If empty, the OS's default resolvers (the ones that predate
	// Tailscale altering the configuration) are used.
	DefaultResolvers []netaddr.IPPort
	// Routes maps a DNS suffix to the resolvers that should be used
	// for queries that fall within that suffix.
	// If a query doesn't match any entry in Routes, the
	// DefaultResolvers are used.
	Routes map[string][]netaddr.IPPort
	// SearchDomains are DNS suffixes to try when expanding
	// single-label queries.
	SearchDomains []string
	// Hosts maps DNS FQDNs to their IPs, which can be a mix of IPv4
	// and IPv6.
	// Queries matching entries in Hosts are resolved locally without
	// recursing off-machine.
	Hosts map[string][]netaddr.IP
	// AuthoritativeSuffixes is a list of fully-qualified DNS suffixes
	// for which the in-process Tailscale resolver is authoritative.
	// Queries for names within AuthoritativeSuffixes can only be
	// fulfilled by entries in Hosts. Queries with no match in Hosts
	// return NXDOMAIN.
	AuthoritativeSuffixes []string
}