fix dns resolver

chain.go

@@ -128,8 +128,14 @@ func (c *Chain) dial(addr string) (net.Conn, error) {
 	if c != nil && c.Resolver != nil {
 		host, port, err := net.SplitHostPort(addr)
 		if err == nil {
-			addrs, _ := c.Resolver.Resolve(host)
-			log.Log(addr, addrs)
+			addrs, er := c.Resolver.Resolve(host)
+			if er != nil {
+				log.Logf("[resolver] %s: %v", addr, er)
+				return nil, er
+			}
+			if Debug {
+				log.Logf("[resolver] %s %v", addr, addrs)
+			}
 			if len(addrs) > 0 {
 				addr = net.JoinHostPort(addrs[0].IP.String(), port)
 			}

cmd/gost/cfg.go

@@ -265,6 +265,9 @@ func parseResolver(cfg string) gost.Resolver {
 	if cfg == "" {
 		return nil
 	}
+	timeout := 30 * time.Second
+	var nss []gost.NameServer
+
 	f, err := os.Open(cfg)
 	if err != nil {
 		for _, s := range strings.Split(cfg, ",") {
@@ -272,13 +275,22 @@ func parseResolver(cfg string) gost.Resolver {
 			if s == "" {
 				continue
 			}
+			ss := strings.Split(s, "/")
+			if len(ss) == 1 {
+				nss = append(nss, gost.NameServer{
+					Addr: ss[0],
+				})
+			}
+			if len(ss) == 2 {
+				nss = append(nss, gost.NameServer{
+					Addr:     ss[0],
+					Protocol: ss[1],
+				})
 			}
-		// return gost.NewBypass(matchers, reversed)
+		}
+		return gost.NewResolver(nss, timeout)
 	}
 
-	timeout := 30 * time.Second
-
-	var nss []gost.NameServer
 	scanner := bufio.NewScanner(f)
 	for scanner.Scan() {
 		line := scanner.Text()
@@ -310,14 +322,13 @@ func parseResolver(cfg string) gost.Resolver {
 		}
 
 		var ns gost.NameServer
-		if len(ss) == 1 {
+		switch len(ss) {
+		case 1:
 			ns.Addr = ss[0]
-		}
-		if len(ss) == 2 {
+		case 2:
 			ns.Addr = ss[0]
 			ns.Protocol = ss[1]
-		}
-		if len(ss) == 3 {
+		default:
 			ns.Addr = ss[0]
 			ns.Protocol = ss[1]
 			ns.Hostname = ss[2]

cmd/gost/dns.txt

-# ip[:port]  [protocol]  [hostname]
-
-# resolver timeout
+# resolver timeout, default 30s.
 timeout     10
 
+# ip[:port]  [protocol]  [hostname]
+
 1.1.1.1:853 tls     cloudflare-dns.com
 8.8.8.8
 8.8.8.8     tcp

cmd/gost/main.go

@@ -506,7 +506,6 @@ func (r *route) serve() error {
 		)
 
 		chain.Resolver = parseResolver(node.Get("dns"))
-		log.Log(chain.Resolver)
 
 		go srv.Serve(handler)
 	}

gost.go

@@ -44,19 +44,19 @@ var (
 )
 
 var (
-	// DefaultTLSConfig is a default TLS config for internal use
+	// DefaultTLSConfig is a default TLS config for internal use.
 	DefaultTLSConfig *tls.Config
 
-	// DefaultUserAgent is the default HTTP User-Agent header used by HTTP and websocket
+	// DefaultUserAgent is the default HTTP User-Agent header used by HTTP and websocket.
 	DefaultUserAgent = "Chrome/60.0.3112.90"
 )
 
-// SetLogger sets a new logger for internal log system
+// SetLogger sets a new logger for internal log system.
 func SetLogger(logger log.Logger) {
 	log.DefaultLogger = logger
 }
 
-// GenCertificate generates a random TLS certificate
+// GenCertificate generates a random TLS certificate.
 func GenCertificate() (cert tls.Certificate, err error) {
 	rawCert, rawKey, err := generateKeyPair()
 	if err != nil {

resolver.go

@@ -6,7 +6,10 @@ import (
 	"crypto/tls"
 	"fmt"
 	"net"
+	"strings"
 	"time"
+
+	"github.com/go-log/log"
 )
 
 var (
@@ -29,6 +32,19 @@ type NameServer struct {
 	Hostname string // for TLS handshake verification
 }
 
+func (ns *NameServer) String() string {
+	addr := ns.Addr
+	prot := ns.Protocol
+	host := ns.Hostname
+	if !strings.Contains(addr, ":") {
+		addr += ":53"
+	}
+	if prot == "" {
+		prot = "udp"
+	}
+	return fmt.Sprintf("%s/%s %s", addr, prot, host)
+}
+
 type resolver struct {
 	Resolver *net.Resolver
 	Servers  []NameServer
@@ -54,6 +70,7 @@ func (r *resolver) init() {
 				if err == nil {
 					break
 				}
+				log.Logf("[resolver] %s : %s", ns, err)
 			}
 			return
 		},
@@ -63,11 +80,15 @@ func (r *resolver) init() {
 func (r *resolver) dial(ctx context.Context, ns NameServer) (net.Conn, error) {
 	var d net.Dialer
 
-	switch ns.Protocol {
+	addr := ns.Addr
+	if !strings.Contains(addr, ":") {
+		addr += ":53"
+	}
+	switch strings.ToLower(ns.Protocol) {
 	case "tcp":
-		return d.DialContext(ctx, "tcp", ns.Addr)
+		return d.DialContext(ctx, "tcp", addr)
 	case "tls":
-		conn, err := d.DialContext(ctx, "tcp", ns.Addr)
+		conn, err := d.DialContext(ctx, "tcp", addr)
 		if err != nil {
 			return nil, err
 		}
@@ -81,7 +102,7 @@ func (r *resolver) dial(ctx context.Context, ns NameServer) (net.Conn, error) {
 	case "udp":
 		fallthrough
 	default:
-		return d.DialContext(ctx, "udp", ns.Addr)
+		return d.DialContext(ctx, "udp", addr)
 	}
 }
 
@@ -104,7 +125,7 @@ func (r *resolver) String() string {
 	b := &bytes.Buffer{}
 	fmt.Fprintf(b, "timeout %v\n", r.Timeout)
 	for i := range r.Servers {
-		fmt.Fprintf(b, "%s/%s %s\n", r.Servers[i].Addr, r.Servers[i].Protocol, r.Servers[i].Hostname)
+		fmt.Fprintln(b, r.Servers[i])
 	}
 	return b.String()
 }