Websockets support

pkg/web/websocket.go

@@ -0,0 +1,67 @@
+// Copyright (c) 2018 The Grumble Authors
+// The use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE-file.
+
+package web
+
+import (
+	"bytes"
+	"io"
+	"net"
+	"time"
+
+	"github.com/gorilla/websocket"
+)
+
+type conn struct {
+	ws     *websocket.Conn
+	msgbuf bytes.Buffer
+}
+
+func (c *conn) Read(b []byte) (n int, err error) {
+	if c.msgbuf.Len() == 0 {
+		_, r, err := c.ws.NextReader()
+		if err != nil {
+			if _, ok := err.(*websocket.CloseError); ok {
+				return 0, io.EOF
+			}
+			return 0, err
+		}
+		if _, err := c.msgbuf.ReadFrom(r); err != nil {
+			return 0, err
+		}
+	}
+	// Impossible to read over message boundaries - will generate EOF
+	return c.msgbuf.Read(b)
+}
+
+func (c *conn) Write(b []byte) (n int, err error) {
+	return len(b), c.ws.WriteMessage(websocket.BinaryMessage, b)
+}
+
+func (c *conn) Close() error {
+	return c.ws.Close()
+}
+
+func (c *conn) LocalAddr() net.Addr {
+	return c.ws.LocalAddr()
+}
+
+func (c *conn) RemoteAddr() net.Addr {
+	return c.ws.RemoteAddr()
+}
+
+func (c *conn) SetDeadline(t time.Time) (err error) {
+	if err = c.ws.SetReadDeadline(t); err != nil {
+		return err
+	}
+	return c.ws.SetWriteDeadline(t)
+}
+
+func (c *conn) SetReadDeadline(t time.Time) error {
+	return c.ws.SetReadDeadline(t)
+}
+
+func (c *conn) SetWriteDeadline(t time.Time) error {
+	return c.ws.SetWriteDeadline(t)
+}

pkg/web/wslisten.go

@@ -0,0 +1,79 @@
+// Copyright (c) 2018 The Grumble Authors
+// The use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE-file.
+
+package web
+
+import (
+	"fmt"
+	"log"
+	"net"
+	"net/http"
+	"sync/atomic"
+	"time"
+
+	"github.com/gorilla/websocket"
+)
+
+var upgrader = websocket.Upgrader{
+	HandshakeTimeout: 20 * time.Second,
+	Subprotocols:     []string{"mumble", "binary"},
+	CheckOrigin: func(r *http.Request) bool {
+		return true
+	},
+}
+
+type Listener struct {
+	sockets chan *conn
+	done    chan struct{}
+	addr    net.Addr
+	closed  int32
+	logger  *log.Logger
+}
+
+func NewListener(laddr net.Addr, logger *log.Logger) *Listener {
+	return &Listener{
+		sockets: make(chan *conn),
+		done:    make(chan struct{}),
+		addr:    laddr,
+		logger:  logger,
+	}
+}
+
+func (l *Listener) Accept() (net.Conn, error) {
+	if atomic.LoadInt32(&l.closed) != 0 {
+		return nil, fmt.Errorf("accept ws %v: use of closed websocket listener", l.addr)
+	}
+	select {
+	case ws := <-l.sockets:
+		return ws, nil
+	case <-l.done:
+		return nil, fmt.Errorf("accept ws %v: use of closed websocket listener", l.addr)
+	}
+}
+
+func (l *Listener) Close() error {
+	if !atomic.CompareAndSwapInt32(&l.closed, 0, 1) {
+		return fmt.Errorf("close ws %v: use of closed websocket listener", l.addr)
+	}
+	close(l.done)
+	return nil
+}
+
+func (l *Listener) Addr() net.Addr {
+	return l.addr
+}
+
+func (l *Listener) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	if atomic.LoadInt32(&l.closed) != 0 {
+		http.Error(w, http.StatusText(http.StatusServiceUnavailable), http.StatusServiceUnavailable)
+		return
+	}
+	l.logger.Printf("Upgrading web connection from: %v", r.RemoteAddr)
+	ws, err := upgrader.Upgrade(w, r, nil)
+	if err != nil {
+		l.logger.Printf("Failed upgrade: %v", err)
+		return
+	}
+	l.sockets <- &conn{ws: ws}
+}