From 616cf118800f10217ce515a76f65dfa63fff30ae Mon Sep 17 00:00:00 2001
From: ilanyu <lanyu19950316@gmail.com>
Date: Mon, 16 Apr 2018 19:47:33 +0800
Subject: [PATCH] change dns server

---
 cmd.go    |  2 ++
 handle.go | 19 +++++++++----------
 main.go   |  3 ++-
 3 files changed, 13 insertions(+), 11 deletions(-)

diff --git a/cmd.go b/cmd.go
index 125673f..479bbd9 100644
--- a/cmd.go
+++ b/cmd.go
@@ -5,12 +5,14 @@ import "flag"
 type Cmd struct {
 	bind string
 	remote string
+	ip string
 }
 
 func parseCmd() Cmd {
 	var cmd Cmd
 	flag.StringVar(&cmd.bind, "l", "0.0.0.0:8888", "listen on ip:port")
 	flag.StringVar(&cmd.remote, "r", "http://idea.lanyus.com:80", "reverse proxy addr")
+	flag.StringVar(&cmd.ip, "ip", "", "reverse proxy addr server ip")
 	flag.Parse()
 	return cmd
 }
\ No newline at end of file
diff --git a/handle.go b/handle.go
index 8b477c4..f9326d5 100644
--- a/handle.go
+++ b/handle.go
@@ -7,8 +7,9 @@ import (
 	"log"
 	"net"
 	"time"
-	"io/ioutil"
 	"context"
+	"github.com/bogdanovich/dns_resolver"
+	"strings"
 )
 
 type handle struct {
@@ -27,19 +28,17 @@ func (this *handle) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		DualStack: true,
 	}
 	http.DefaultTransport.(*http.Transport).DialContext = func(ctx context.Context, network, addr string) (net.Conn, error) {
-		if addr == "idea.lanyus.com:80" {
-			resp, err := http.Get("http://119.29.29.29/d?dn=idea.lanyus.com")
+		remote := strings.Split(addr, ":")
+		if cmd.ip == "" {
+			resolver := dns_resolver.New([]string{"114.114.114.114", "114.114.115.115", "119.29.29.29", "223.5.5.5", "8.8.8.8", "208.67.222.222", "208.67.220.220"})
+			resolver.RetryTimes = 5
+			ip, err := resolver.LookupHost(remote[0])
 			if err != nil {
 				log.Println(err)
 			}
-			defer resp.Body.Close()
-			res, err := ioutil.ReadAll(resp.Body)
-			if err != nil {
-				log.Println(err)
-			}
-			addr = string(res) + ":80"
+			cmd.ip = ip[0].String()
 		}
-
+		addr = cmd.ip + ":" + remote[1]
 		return dialer.DialContext(ctx, network, addr)
 	}
 	proxy := httputil.NewSingleHostReverseProxy(remote)
diff --git a/main.go b/main.go
index 025bf77..05c1f68 100644
--- a/main.go
+++ b/main.go
@@ -5,6 +5,7 @@ import (
 	"log"
 )
 
+var cmd Cmd
 var srv http.Server
 
 func StartServer(bind string, remote string)  {
@@ -26,6 +27,6 @@ func StopServer()  {
 }
 
 func main() {
-	cmd := parseCmd()
+	cmd = parseCmd()
 	StartServer(cmd.bind, cmd.remote)
 }