From 0d01e8a4eb784f2ac3431ec046776052ddda18d4 Mon Sep 17 00:00:00 2001
From: nadoo <287492+nadoo@users.noreply.github.com>
Date: Sun, 16 Jul 2017 12:16:50 +0800
Subject: [PATCH] fixed a bug in strategy.go which may leads to infinite
 recursion in the condition of all remote proxy disabled.

---
 README.md   |  5 -----
 dnstun.go   | 11 +++++------
 http.go     |  1 +
 proxy.go    |  9 +++++----
 strategy.go | 14 +++++++++++---
 5 files changed, 22 insertions(+), 18 deletions(-)

diff --git a/README.md b/README.md
index 453da30..6d0a37c 100644
--- a/README.md
+++ b/README.md
@@ -5,11 +5,6 @@ glider is a forward proxy with several protocols support.
 
 	go get -u github.com/nadoo/glider
 
-## Build
-
-	cd $GOPATH/src/github.com/nadoo/glider
-	go build
-
 ## Usage
 ```bash
 glider v0.1 usage:
diff --git a/dnstun.go b/dnstun.go
index f966878..8fa4594 100644
--- a/dnstun.go
+++ b/dnstun.go
@@ -23,19 +23,18 @@ func DNSTunProxy(addr, raddr string, upProxy Proxy) (Proxy, error) {
 	return s, nil
 }
 
-// ListenAndServe redirected requests as a server.
+// ListenAndServe .
 func (s *dnstun) ListenAndServe() {
 	l, err := net.ListenPacket("udp", s.addr)
 	if err != nil {
 		logf("failed to listen on %s: %v", s.addr, err)
 		return
 	}
+	defer l.Close()
 
 	logf("listening UDP on %s", s.addr)
 
 	for {
-		defer l.Close()
-
 		data := make([]byte, 512)
 		n, clientAddr, err := l.ReadFrom(data)
 		if err != nil {
@@ -60,7 +59,7 @@ func (s *dnstun) ListenAndServe() {
 			rc.Write(length)
 			rc.Write(data)
 
-			buf, err := ioutil.ReadAll(rc)
+			resp, err := ioutil.ReadAll(rc)
 			if err != nil {
 				logf("error in ioutil.ReadAll: %s\n", err)
 				return
@@ -68,8 +67,8 @@ func (s *dnstun) ListenAndServe() {
 
 			// length is not needed in udp dns response. (2 bytes)
 			// SEE RFC1035, section 4.2.2 TCP: The message is prefixed with a two byte length field which gives the message length, excluding the two byte length field.
-			if len(buf) > 2 {
-				msg := buf[2:]
+			if len(resp) > 2 {
+				msg := resp[2:]
 				_, err = l.WriteTo(msg, clientAddr)
 				if err != nil {
 					logf("error in local write: %s\n", err)
diff --git a/http.go b/http.go
index d7134b0..b42766d 100644
--- a/http.go
+++ b/http.go
@@ -38,6 +38,7 @@ func (s *httpproxy) ListenAndServe() {
 		logf("failed to listen on %s: %v", s.addr, err)
 		return
 	}
+	defer l.Close()
 
 	logf("listening TCP on %s", s.addr)
 
diff --git a/proxy.go b/proxy.go
index ba30ca9..c9983c5 100644
--- a/proxy.go
+++ b/proxy.go
@@ -141,14 +141,15 @@ func check(p Proxy, target string, duration int) {
 		startTime := time.Now()
 		c, err := p.Dial("tcp", target)
 		if err != nil {
-			logf("proxy-check %s -> %s, error: %s, set to disabled.", p.Addr(), config.CheckSite, err)
+			logf("proxy-check %s -> %s, set to DISABLED. error: %s", p.Addr(), config.CheckSite, err)
 			p.SetEnable(false)
 			continue
 		}
-		dialTime := time.Since(startTime)
 		c.Close()
-
 		p.SetEnable(true)
-		logf("proxy-check: %s -> %s, connect time: %d", p.Addr(), config.CheckSite, dialTime)
+
+		// TODO: choose the fastest proxy.
+		dialTime := time.Since(startTime)
+		logf("proxy-check: %s -> %s, connect time: %s", p.Addr(), config.CheckSite, dialTime.String())
 	}
 }
diff --git a/strategy.go b/strategy.go
index e09541e..aa8eaa7 100644
--- a/strategy.go
+++ b/strategy.go
@@ -38,9 +38,17 @@ func (p *strategyProxy) NextProxy() Proxy {
 		return p.forwarders[0]
 	}
 
-	p.idx = (p.idx + 1) % n
-	if !p.forwarders[p.idx].Enabled() {
-		return p.NextProxy()
+	found := false
+	for i := 0; i < n; i++ {
+		p.idx = (p.idx + 1) % n
+		if p.forwarders[p.idx].Enabled() {
+			found = true
+			break
+		}
+	}
+
+	if !found {
+		logf("NO AVALIABLE PROXY FOUND! please check your network or proxy server settings.")
 	}
 
 	return p.forwarders[p.idx]