From 5f8800d643f05462c8a790f19f7d095f4c0ee536 Mon Sep 17 00:00:00 2001
From: xiaolunzhou <51695571+JayL-zxl@users.noreply.github.com>
Date: Mon, 7 Dec 2020 19:51:02 +0800
Subject: [PATCH] Update client.go

---
 dns/client.go | 15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/dns/client.go b/dns/client.go
index 0d11fe9..9f7eb8e 100644
--- a/dns/client.go
+++ b/dns/client.go
@@ -5,7 +5,6 @@ import (
 	"encoding/base64"
 	"encoding/binary"
 	"errors"
-	"fmt"
 	"io"
 	"io/ioutil"
 	"net"
@@ -156,7 +155,6 @@ func (c *Client) extractAnswer(resp *Message) ([]string, int) {
 func (c *Client) exchange(qname string, reqBytes []byte, preferTCP bool) (
 	server, network, dialerAddr string, respBytes []byte, err error) {
 	ups := c.UpStream(qname)
-	fmt.Println(ups)
 	network = "tcp"
 	dialer := c.proxy.NextDialer(qname + ":53")
 	// if we are resolving the dialer's domain, then use Direct to avoid denpency loop
@@ -191,11 +189,9 @@ func (c *Client) exchange(qname string, reqBytes []byte, preferTCP bool) (
 			network = "udp"
 			rc, err = dialer.Dial(network, server)
 		case "dot":
-			network="tcp"
-			rc,err=tls.Dial(network,server,&tls.Config{InsecureSkipVerify: false,})
+			rc,err=tls.Dial("tcp",server,&tls.Config{InsecureSkipVerify: false,})
 		case "doh":
 			net.DefaultResolver=&net.Resolver{}
-			network="doh"
 		default:
 			break
 		}
@@ -207,14 +203,16 @@ func (c *Client) exchange(qname string, reqBytes []byte, preferTCP bool) (
 			continue
 		}
 		//TODO: if we use DOH (network=="doh") we don't need close connection
-		if network!="doh" {defer rc.Close()}
+		if network!="doh"{
+			defer rc.Close()
+		}
 
 		// TODO: support timeout setting for different upstream server
 		if c.config.Timeout > 0 && network!="doh" {
 			rc.SetDeadline(time.Now().Add(time.Duration(c.config.Timeout) * time.Second))
 		}
 
-		switch network {
+		switch op {
 		case "tcp","dot":
 			respBytes, err = c.exchangeTCP(rc, reqBytes)
 		case "udp":
@@ -222,7 +220,6 @@ func (c *Client) exchange(qname string, reqBytes []byte, preferTCP bool) (
 		case "doh":
 			respBytes, err = c.exchangeHTTPS(server, reqBytes)
 		}
-
 		if err == nil {
 			break
 		}
@@ -239,7 +236,7 @@ func (c *Client) exchange(qname string, reqBytes []byte, preferTCP bool) (
 		c.proxy.Record(dialer, false)
 	}
 
-	return server, network, dialer.Addr(), respBytes, err
+	return server, op, dialer.Addr(), respBytes, err
 }
 //exchangeHTTP exchange with server over https
 func (c*Client) exchangeHTTPS(server string,reqBytes[]byte)(body[]byte,err error){