add bindAddr for darwin

transport/internet/sockopt_darwin.go

@@ -165,7 +165,7 @@ func applyInboundSocketOptions(network string, fd uintptr, config *SocketConfig)
 				}
 			}
 		}
-		
+
 		if config.TcpKeepAliveIdle > 0 || config.TcpKeepAliveInterval > 0 {
 			if config.TcpKeepAliveIdle > 0 {
 				if err := unix.SetsockoptInt(int(fd), unix.IPPROTO_TCP, unix.TCP_KEEPALIVE, int(config.TcpKeepAliveInterval)); err != nil {
@@ -191,14 +191,42 @@ func applyInboundSocketOptions(network string, fd uintptr, config *SocketConfig)
 }
 
 func bindAddr(fd uintptr, address []byte, port uint32) error {
-	return nil
+	setReuseAddr(fd)
+	setReusePort(fd)
+
+	var sockaddr unix.Sockaddr
+
+	switch len(address) {
+	case net.IPv4len:
+		a4 := &unix.SockaddrInet4{
+			Port: int(port),
+		}
+		copy(a4.Addr[:], address)
+		sockaddr = a4
+	case net.IPv6len:
+		a6 := &unix.SockaddrInet6{
+			Port: int(port),
+		}
+		copy(a6.Addr[:], address)
+		sockaddr = a6
+	default:
+		return newError("unexpected length of ip")
+	}
+
+	return unix.Bind(int(fd), sockaddr)
 }
 
 func setReuseAddr(fd uintptr) error {
+	if err := unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, unix.SO_REUSEADDR, 1); err != nil {
+		return newError("failed to set SO_REUSEADDR").Base(err).AtWarning()
+	}
 	return nil
 }
 
 func setReusePort(fd uintptr) error {
+	if err := unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, unix.SO_REUSEPORT, 1); err != nil {
+		return newError("failed to set SO_REUSEPORT").Base(err).AtWarning()
+	}
 	return nil
 }
 func getInterfaceIndexByName(name string) int {