wip: migrate to mono-repo. SPN has already been moved to spn/

service/resolver/resolver-env.go

@@ -0,0 +1,158 @@
+package resolver
+
+import (
+	"context"
+	"fmt"
+	"net"
+	"strings"
+
+	"github.com/miekg/dns"
+
+	"github.com/safing/portbase/log"
+	"github.com/safing/portmaster/service/netenv"
+	"github.com/safing/portmaster/service/network/netutils"
+)
+
+const (
+	// InternalSpecialUseDomain is the domain scope used for internal services.
+	InternalSpecialUseDomain = "portmaster.home.arpa."
+
+	routerDomain        = "router.local." + InternalSpecialUseDomain
+	captivePortalDomain = "captiveportal.local." + InternalSpecialUseDomain
+)
+
+var (
+	envResolver = &Resolver{
+		ConfigURL: ServerSourceEnv,
+		Info: &ResolverInfo{
+			Type:    ServerTypeEnv,
+			Source:  ServerSourceEnv,
+			IPScope: netutils.SiteLocal,
+		},
+		Conn: &envResolverConn{},
+	}
+	envResolvers = []*Resolver{envResolver}
+
+	internalSpecialUseSOA     dns.RR
+	internalSpecialUseComment dns.RR
+)
+
+func prepEnvResolver() (err error) {
+	netenv.SpecialCaptivePortalDomain = captivePortalDomain
+
+	internalSpecialUseSOA, err = dns.NewRR(fmt.Sprintf(
+		"%s 17 IN SOA localhost. none.localhost. 0 0 0 0 0",
+		InternalSpecialUseDomain,
+	))
+	if err != nil {
+		return err
+	}
+
+	internalSpecialUseComment, err = dns.NewRR(fmt.Sprintf(
+		`%s 17 IN TXT "This is a special use TLD of the Portmaster."`,
+		InternalSpecialUseDomain,
+	))
+	return err
+}
+
+type envResolverConn struct{}
+
+func (er *envResolverConn) Query(ctx context.Context, q *Query) (*RRCache, error) {
+	switch uint16(q.QType) {
+	case dns.TypeA, dns.TypeAAAA: // We respond with all IPv4/6 addresses we can find.
+		// Check for exact matches.
+		switch q.FQDN {
+		case captivePortalDomain:
+			// Get IP address of the captive portal.
+			portal := netenv.GetCaptivePortal()
+			portalIP := portal.IP
+			if portalIP == nil {
+				portalIP = netenv.PortalTestIP
+			}
+			// Convert IP to record and respond.
+			records, err := netutils.IPsToRRs(q.FQDN, []net.IP{portalIP})
+			if err != nil {
+				log.Warningf("nameserver: failed to create captive portal response to %s: %s", q.FQDN, err)
+				return er.nxDomain(q), nil
+			}
+			return er.makeRRCache(q, records), nil
+
+		case routerDomain:
+			// Get gateways from netenv system.
+			routers := netenv.Gateways()
+			if len(routers) == 0 {
+				return er.nxDomain(q), nil
+			}
+			// Convert IP to record and respond.
+			records, err := netutils.IPsToRRs(q.FQDN, routers)
+			if err != nil {
+				log.Warningf("nameserver: failed to create gateway response to %s: %s", q.FQDN, err)
+				return er.nxDomain(q), nil
+			}
+			return er.makeRRCache(q, records), nil
+		}
+
+		// Check for suffix matches.
+		if strings.HasSuffix(q.FQDN, CompatDNSCheckInternalDomainScope) {
+			subdomain := strings.TrimSuffix(q.FQDN, CompatDNSCheckInternalDomainScope)
+			respondWith := CompatSubmitDNSCheckDomain(subdomain)
+
+			// We'll get an A record. Only respond if it's an A question.
+			if respondWith != nil && uint16(q.QType) == dns.TypeA {
+				records, err := netutils.IPsToRRs(q.FQDN, []net.IP{respondWith})
+				if err != nil {
+					log.Warningf("nameserver: failed to create dns check response to %s: %s", q.FQDN, err)
+					return er.nxDomain(q), nil
+				}
+				return er.makeRRCache(q, records), nil
+			}
+		}
+	case dns.TypeSOA:
+		// Direct query for the SOA record.
+		if q.FQDN == InternalSpecialUseDomain {
+			return er.makeRRCache(q, []dns.RR{internalSpecialUseSOA}), nil
+		}
+	}
+
+	// No match, reply with NXDOMAIN and SOA record
+	reply := er.nxDomain(q)
+	reply.Ns = []dns.RR{internalSpecialUseSOA}
+	return reply, nil
+}
+
+func (er *envResolverConn) nxDomain(q *Query) *RRCache {
+	return er.makeRRCache(q, nil)
+}
+
+func (er *envResolverConn) makeRRCache(q *Query, answers []dns.RR) *RRCache {
+	// Disable caching, as the env always has the raw data available.
+	q.NoCaching = true
+
+	rrCache := &RRCache{
+		Domain:   q.FQDN,
+		Question: q.QType,
+		RCode:    dns.RcodeSuccess,
+		Answer:   answers,
+		Extra:    []dns.RR{internalSpecialUseComment}, // Always add comment about this TLD.
+		Resolver: envResolver.Info.Copy(),
+	}
+	if len(rrCache.Answer) == 0 {
+		rrCache.RCode = dns.RcodeNameError
+	}
+	return rrCache
+}
+
+func (er *envResolverConn) ReportFailure() {}
+
+func (er *envResolverConn) IsFailing() bool {
+	return false
+}
+
+func (er *envResolverConn) ResetFailure() {}
+
+func (er *envResolverConn) ForceReconnect(_ context.Context) {}
+
+// QueryPortmasterEnv queries the environment resolver directly.
+func QueryPortmasterEnv(ctx context.Context, q *Query) (*RRCache, error) {
+	return envResolver.Conn.Query(ctx, q)
+}