Domain lookups, using mDNS

Added DomainLookup* to the Zone interface

nameserver/zone.go

@@ -48,6 +48,10 @@ type Zone interface {
 	DeleteRecord(ident string, ip net.IP) error
 	// Delete all records for an ident in the local database
 	DeleteRecordsFor(ident string) error
+	// Lookup for a name in the whole domain
+	DomainLookupName(name string) ([]ZoneRecord, error)
+	// Lookup for an address in the whole domain
+	DomainLookupInaddr(inaddr string) ([]ZoneRecord, error)
 	// Return a status string
 	Status() string
 }

nameserver/zone_lookup.go

@@ -28,6 +28,67 @@ func (zone *zoneDb) LookupName(name string) (res []ZoneRecord, err error) {
 	return
 }
 
+// Perform a lookup for a name in the zone
+// The name can be resolved locally with the local database or with some other resolution method (eg, a mDNS query)
+func (zone *zoneDb) DomainLookupName(name string) (res []ZoneRecord, err error) {
+	name = dns.Fqdn(name)
+	Debug.Printf("[zonedb] Looking for name '%s' in local(&remote) database", name)
+
+	zone.mx.RLock()
+	now := zone.clock.Now()
+	for identName, nameset := range zone.idents {
+		for _, ze := range nameset.getEntriesForName(name) {
+			// filter the entries with expired TTL
+			// locally introduced entries are nver expired as the always have TTL=0
+			if ze.hasExpired(now) {
+				Debug.Printf("[zonedb] '%s': expired entry '%s' ignored: removing", name, ze)
+				nameset.deleteName(name)
+			} else {
+				res = append(res, ze)
+			}
+		}
+		if identName != defaultRemoteIdent {
+			nameset.touchName(name, now)
+		}
+	}
+	zone.mx.RUnlock()
+
+	if len(res) > 0 {
+		Debug.Printf("[zonedb] '%s' resolved in local database", name)
+	} else {
+		// no local results have been obtained in the local database: try with a mDNS query
+		// (this request is not a background query, so we cannot delay the response)
+		Debug.Printf("[zonedb] name '%s' not in local database: trying with mDNS", name)
+		ips, err := zone.mdnsCli.LookupName(name)
+		if err != nil {
+			Debug.Printf("[zonedb] mDNS lookup error for '%s': %s", name, err)
+			return nil, err
+		}
+
+		// if the request has been successful, save the IP in the local database and return the corresponding ZoneRecord
+		// (we do not get the remote ident in the mDNS reply, so we save it in a "remote" ident)
+		Debug.Printf("[zonedb] adding '%s' (obtained with mDNS) to '%s'", ips, name)
+		res = make([]ZoneRecord, len(ips))
+		zone.mx.Lock()
+		now = zone.clock.Now()
+		for i, zr := range ips {
+			res[i], err = zone.getNamesSet(defaultRemoteIdent).addIPToName(zr, now)
+			if err != nil {
+				zone.mx.Unlock()
+				Warning.Printf("[zonedb] IP [%s] insertion for '%s' failed: %s", ips, name, err)
+				return nil, err
+			}
+		}
+		zone.mx.Unlock()
+	}
+
+	if len(res) > 0 {
+		return res, nil
+	}
+
+	return nil, LookupError(name)
+}
+
 // Perform a lookup for a IP address in the zone
 // The address can be resolved locally with the local database
 func (zone *zoneDb) LookupInaddr(inaddr string) (res []ZoneRecord, err error) {
@@ -53,3 +114,70 @@ func (zone *zoneDb) LookupInaddr(inaddr string) (res []ZoneRecord, err error) {
 	}
 	return
 }
+
+// Perform a lookup for a IP address in the zone
+// The address can be resolved either with the local database or
+// with some other resolution method (eg, a mDNS query)
+func (zone *zoneDb) DomainLookupInaddr(inaddr string) (res []ZoneRecord, err error) {
+	revIPv4, err := raddrToIPv4(inaddr)
+	if err != nil {
+		return nil, newParseError("lookup address", inaddr)
+	}
+
+	Debug.Printf("[zonedb] Looking for address in local(&remote) database: '%s' (%s)", revIPv4, inaddr)
+
+	zone.mx.RLock()
+	now := zone.clock.Now()
+	for identName, nameset := range zone.idents {
+		for _, ze := range nameset.getEntriesForIP(revIPv4) {
+			// filter the entries with expired TTL
+			// locally introduced entries are nver expired as the always have TTL=0
+			if ze.hasExpired(now) {
+				Debug.Printf("[zonedb] '%s': expired entry '%s' ignored: removing", revIPv4, ze)
+				nameset.deleteIP(revIPv4)
+			} else {
+				res = append(res, ZoneRecord(ze))
+				if identName != defaultRemoteIdent {
+					nameset.touchName(ze.Name(), now)
+				}
+			}
+		}
+	}
+	zone.mx.RUnlock()
+
+	if len(res) > 0 {
+		Debug.Printf("[zonedb] '%s' resolved in local database", inaddr)
+	} else {
+		// no local results have been obtained in the local database: try with a mDNS query
+		Debug.Printf("[zonedb] '%s'(%+v) not in local database... trying with mDNS", inaddr, revIPv4)
+		names, err := zone.mdnsCli.LookupInaddr(inaddr)
+		if err != nil {
+			Debug.Printf("[zonedb] mDNS lookup error for '%s': %s", inaddr, err)
+			return nil, err
+		}
+
+		// if the request has been successful, save the IP in the local database and return the corresponding ZoneRecord
+		// (we do not get the remote ident in the mDNS reply, so we save it in a "remote" ident)
+		Debug.Printf("[zonedb] adding '%s' (obtained with mDNS) to '%s'", names, revIPv4)
+		res = make([]ZoneRecord, len(names))
+		zone.mx.Lock()
+		now = zone.clock.Now()
+		for i, name := range names {
+			res[i], err = zone.getNamesSet(defaultRemoteIdent).addIPToName(name, now)
+			if err != nil {
+				zone.mx.Unlock()
+				Warning.Printf("[zonedb] Name '%s' insertion for %s failed: %s", name.Name(), revIPv4, err)
+				return nil, err
+			}
+		}
+		zone.mx.Unlock()
+	}
+
+	if len(res) > 0 {
+		return res, nil
+	}
+
+	return nil, LookupError(inaddr)
+
+}
+