WebSocket support

irc/websocket.go

@@ -0,0 +1,70 @@
+package irc
+
+import (
+	"bytes"
+	"errors"
+	"github.com/gorilla/websocket"
+	"net/http"
+	"time"
+	"unicode/utf8"
+)
+
+var wsUpgrader = websocket.Upgrader{
+	ReadBufferSize:  2 * 1024,
+	WriteBufferSize: 2 * 1024,
+	// If a WS session contains sensitive information, and you choose to use
+	// cookies for authentication (during the HTTP(S) upgrade request), then
+	// you should check that Origin is a domain under your control. If it
+	// isn't, then it is possible for users of your site, visiting a naughty
+	// Origin, to have a WS opened using their credentials. See
+	// http://www.christian-schneider.net/CrossSiteWebSocketHijacking.html#main.
+	// We don't care about Origin because the (IRC) authentication is contained
+	// in the WS stream -- the WS session is not privileged when it is opened.
+	CheckOrigin: func(r *http.Request) bool { return true },
+}
+
+// WSContainer wraps a WebSocket connection so that it implements net.Conn
+// entirely.
+type WSContainer struct {
+	*websocket.Conn
+}
+
+func (ws WSContainer) Read(b []byte) (n int, err error) {
+	var messageType int
+	var bytes []byte
+
+	for {
+		messageType, bytes, err = ws.ReadMessage()
+		if messageType == websocket.TextMessage {
+			n = copy(b, bytes)
+			return
+		}
+		if len(bytes) == 0 {
+			return 0, nil
+		}
+		// Throw other kind of messages away.
+	}
+	// We don't want to return (0, nil) here because that would mean the
+	// connection is closed (Read calls must block until data is received).
+}
+
+func (ws WSContainer) Write(b []byte) (n int, err error) {
+	if !utf8.Valid(b) {
+		return 0, errors.New("outgoing WebSocket message isn't valid UTF-8")
+	}
+
+	b = bytes.TrimSuffix(b, []byte("\r\n"))
+	n = len(b)
+	err = ws.WriteMessage(websocket.TextMessage, b)
+	return
+}
+
+// SetDeadline is part of the net.Conn interface.
+func (ws WSContainer) SetDeadline(t time.Time) (err error) {
+	err = ws.SetWriteDeadline(t)
+	if err != nil {
+		return
+	}
+	err = ws.SetReadDeadline(t)
+	return
+}