initial commit

listener/dns/server.go

@@ -0,0 +1,110 @@
+package dns
+
+import (
+	"context"
+	"crypto/tls"
+	"errors"
+	"io"
+	"net"
+	"net/http"
+	"time"
+)
+
+type Server interface {
+	ListenAndServe() error
+	Shutdown() error
+}
+
+type dohServer struct {
+	addr      string
+	tlsConfig *tls.Config
+	server    *http.Server
+}
+
+func (s *dohServer) ListenAndServe() error {
+	ln, err := net.Listen("tcp", s.addr)
+	if err != nil {
+		return err
+	}
+	ln = tls.NewListener(ln, s.tlsConfig)
+	return s.server.Serve(ln)
+}
+
+func (s *dohServer) Shutdown() error {
+	return s.server.Shutdown(context.Background())
+}
+
+type ResponseWriter interface {
+	io.Writer
+	RemoteAddr() net.Addr
+}
+
+type dohResponseWriter struct {
+	raddr net.Addr
+	http.ResponseWriter
+}
+
+func (w *dohResponseWriter) RemoteAddr() net.Addr {
+	return w.raddr
+}
+
+type serverConn struct {
+	r      io.Reader
+	w      ResponseWriter
+	laddr  net.Addr
+	closed chan struct{}
+}
+
+func (c *serverConn) Read(b []byte) (n int, err error) {
+	select {
+	case <-c.closed:
+		err = io.ErrClosedPipe
+		return
+	default:
+		return c.r.Read(b)
+	}
+}
+
+func (c *serverConn) Write(b []byte) (n int, err error) {
+	select {
+	case <-c.closed:
+		err = io.ErrClosedPipe
+		return
+	default:
+		return c.w.Write(b)
+	}
+}
+
+func (c *serverConn) Close() error {
+	select {
+	case <-c.closed:
+	default:
+		close(c.closed)
+	}
+	return nil
+}
+
+func (c *serverConn) Wait() error {
+	<-c.closed
+	return nil
+}
+
+func (c *serverConn) LocalAddr() net.Addr {
+	return c.laddr
+}
+
+func (c *serverConn) RemoteAddr() net.Addr {
+	return c.w.RemoteAddr()
+}
+
+func (c *serverConn) SetDeadline(t time.Time) error {
+	return &net.OpError{Op: "set", Net: "dns", Source: nil, Addr: nil, Err: errors.New("deadline not supported")}
+}
+
+func (c *serverConn) SetReadDeadline(t time.Time) error {
+	return &net.OpError{Op: "set", Net: "dns", Source: nil, Addr: nil, Err: errors.New("deadline not supported")}
+}
+
+func (c *serverConn) SetWriteDeadline(t time.Time) error {
+	return &net.OpError{Op: "set", Net: "dns", Source: nil, Addr: nil, Err: errors.New("deadline not supported")}
+}