Add port in Proxy to avoid re-calc in PAC.

pac.go

@@ -101,8 +101,7 @@ func genPAC(c *clientConn) []byte {
 	buf := new(bytes.Buffer)
 
 	host, _ := splitHostPort(c.LocalAddr().String())
-	_, port := splitHostPort(c.proxy.addr)
-	proxyAddr := net.JoinHostPort(host, port)
+	proxyAddr := net.JoinHostPort(host, c.proxy.port)
 
 	if *pac.directList == "" {
 		// Empty direct domain list

proxy.go

@@ -30,7 +30,8 @@ const sslLeastDuration = time.Second
 // Some code are learnt from the http package
 
 type Proxy struct {
-	addr string // listen address
+	addr string // listen address, contains port
+	port string
 }
 
 type connType byte
@@ -125,7 +126,8 @@ var (
 )
 
 func NewProxy(addr string) *Proxy {
-	return &Proxy{addr: addr}
+	_, port := splitHostPort(addr)
+	return &Proxy{addr: addr, port: port}
 }
 
 func (py *Proxy) Serve(done chan byte) {