Merge branch 'master' of github.com:DNSCrypt/dnscrypt-proxy

* 'master' of github.com:DNSCrypt/dnscrypt-proxy:
  add timeout for udp and tcp dialer
  Use blocking channel instead of looping sleep for less CPU usage

dnscrypt-proxy/coldstart.go

@@ -17,14 +17,13 @@ type CaptivePortalMap map[string]CaptivePortalEntryIPs
 type CaptivePortalHandler struct {
 	cancelChannel chan struct{}
 	countChannel  chan struct{}
+	waitChannel   chan struct{}
 	channelCount  int
 }
 
 func (captivePortalHandler *CaptivePortalHandler) Stop() {
 	close(captivePortalHandler.cancelChannel)
-	for len(captivePortalHandler.countChannel) < captivePortalHandler.channelCount {
-		time.Sleep(10 * time.Millisecond)
-	}
+	<-captivePortalHandler.waitChannel
 	close(captivePortalHandler.countChannel)
 }
 
@@ -138,6 +137,9 @@ func addColdStartListener(
 		}
 		clientPc.Close()
 		captivePortalHandler.countChannel <- struct{}{}
+		if len(captivePortalHandler.countChannel) == captivePortalHandler.channelCount {
+			close(captivePortalHandler.waitChannel)
+		}
 	}()
 	return nil
 }
@@ -186,6 +188,7 @@ func ColdStart(proxy *Proxy) (*CaptivePortalHandler, error) {
 	captivePortalHandler := CaptivePortalHandler{
 		cancelChannel: make(chan struct{}),
 		countChannel:  make(chan struct{}, len(listenAddrStrs)),
+		waitChannel:   make(chan struct{}),
 		channelCount:  0,
 	}
 	for _, listenAddrStr := range listenAddrStrs {

dnscrypt-proxy/proxy.go

@@ -517,7 +517,7 @@ func (proxy *Proxy) exchangeWithUDPServer(
 	var pc net.Conn
 	proxyDialer := proxy.xTransport.proxyDialer
 	if proxyDialer == nil {
-		pc, err = net.DialUDP("udp", nil, upstreamAddr)
+		pc, err = net.DialTimeout("udp", upstreamAddr.String(), serverInfo.Timeout)
 	} else {
 		pc, err = (*proxyDialer).Dial("udp", upstreamAddr.String())
 	}
@@ -560,7 +560,7 @@ func (proxy *Proxy) exchangeWithTCPServer(
 	var pc net.Conn
 	proxyDialer := proxy.xTransport.proxyDialer
 	if proxyDialer == nil {
-		pc, err = net.DialTCP("tcp", nil, upstreamAddr)
+		pc, err = net.DialTimeout("tcp", upstreamAddr.String(), serverInfo.Timeout)
 	} else {
 		pc, err = (*proxyDialer).Dial("tcp", upstreamAddr.String())
 	}