update IPToHost func

common/dns/dns.go

@@ -11,7 +11,7 @@ type FakeDns interface {
 	// GenerateFakeResponse(request []byte) ([]byte, error)
 
 	// IPToHost returns the corresponding domain for the given IP.
-	IPToHost(ip net.IP) string
+	IPToHost(ip net.IP) (string, bool)
 
 	// IsFakeIP checks if the given ip is a fake IP.
 	// IsFakeIP(ip net.IP) bool

common/dns/fakedns/server.go

@@ -57,13 +57,13 @@ func (s *Server) StartServer(addr string) error {
 	return nil
 }
 
-func (s *Server) IPToHost(ip net.IP) string {
+func (s *Server) IPToHost(ip net.IP) (string, bool) {
 	c := s.c.Get(ip.String())
 	if c == nil {
-		return ""
+		return "", false
 	}
 	fqdn := c.(*D.Msg).Question[0].Name
-	return strings.TrimRight(fqdn, ".")
+	return strings.TrimRight(fqdn, "."), true
 }
 
 func NewServer(fakeIPRange, hostsLine string) (*Server, error) {

proxy/dnsfallback/udp.go

@@ -28,14 +28,14 @@ func NewUDPHandler() core.UDPConnHandler {
 
 func (h *udpHandler) Connect(conn core.UDPConn, udpAddr *net.UDPAddr) error {
 	if udpAddr.Port != dns.CommonDnsPort {
-		return errors.New("Cannot handle non-DNS packet")
+		return errors.New("cannot handle non-DNS packet")
 	}
 	return nil
 }
 
 func (h *udpHandler) ReceiveTo(conn core.UDPConn, data []byte, addr *net.UDPAddr) error {
 	if len(data) < dnsHeaderLength {
-		return errors.New("Received malformed DNS query")
+		return errors.New("received malformed DNS query")
 	}
 	//  DNS Header
 	//  0  1  2  3  4  5  6  7  0  1  2  3  4  5  6  7

proxy/socks/tcp.go

@@ -150,8 +150,8 @@ func (h *tcpHandler) Handle(conn net.Conn, target *net.TCPAddr) error {
 	// Replace with a domain name if target address IP is a fake IP.
 	var targetHost = target.IP.String()
 	if h.fakeDns != nil {
-		if t := h.fakeDns.IPToHost(target.IP); t != "" {
-			targetHost = t
+		if host, exist := h.fakeDns.IPToHost(target.IP); exist {
+			targetHost = host
 		}
 	}
 

proxy/socks/udp.go

@@ -108,8 +108,8 @@ func (h *udpHandler) Connect(conn core.UDPConn, target *net.UDPAddr) error {
 				return nil // skip dns
 			}
 		*/
-		if t := h.fakeDns.IPToHost(target.IP); t != "" {
-			targetHost = t
+		if host, exist := h.fakeDns.IPToHost(target.IP); exist {
+			targetHost = host
 		}
 	}
 	dest := net.JoinHostPort(targetHost, strconv.Itoa(target.Port))
@@ -213,8 +213,8 @@ func (h *udpHandler) ReceiveTo(conn core.UDPConn, data []byte, addr *net.UDPAddr
 	if ok1 && ok2 {
 		var targetHost = addr.IP.String()
 		if h.fakeDns != nil {
-			if t := h.fakeDns.IPToHost(addr.IP); t != "" {
-				targetHost = t
+			if host, exist := h.fakeDns.IPToHost(addr.IP); exist {
+				targetHost = host
 			}
 		}