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freman · May 18, 2016 · 8a7f999 · 8a7f999
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diff --git a/README.md b/README.md
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+# TestTerminal
+
+Proof of concept terminal.
+
+This is a small component of a much larger system including authentication, access control and security - do not use it.
+
+## Getting
+
+```
+go get github.com/freman/goterm
+```
+
+## Running
+
+Not included is https://github.com/sourcelair/xterm.js
+
+```
+cd src/github.com/freman/goterm/assets
+git clone https://github.com/sourcelair/xterm.js
+$GOPATH/bin/goterm -assets `pwd`
+```
diff --git a/assets/index.html b/assets/index.html
@@ -0,0 +1,66 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+	<title>Xterm</title>
+	<link rel="stylesheet" href="/main.css" />
+	<link rel="stylesheet" href="/xterm.js/src/xterm.css" />
+	<link rel="stylesheet" href="/xterm.js/addons/fullscreen/fullscreen.css" />
+</head>
+<body>
+	<div id="xterm"></div>
+
+	<script src="/xterm.js/src/xterm.js" ></script>
+	<script src="/xterm.js/addons/fit/fit.js" ></script>
+	<script src="/xterm.js/addons/fullscreen/fullscreen.js" ></script>
+	<script>
+	var term;
+	var websocket = new WebSocket("ws://" + window.location.hostname + ":" + window.location.port + "/term");
+	websocket.binaryType = "arraybuffer";
+
+	function ab2str(buf) {
+		return String.fromCharCode.apply(null, new Uint8Array(buf));
+	}
+
+	websocket.onopen = function(evt) {
+		term = new Terminal({
+			screenKeys: true,
+			useStyle: true,
+			cursorBlink: true,
+		});
+
+		term.on('data', function(data) {
+			websocket.send(new TextEncoder().encode("\x00" + data));
+		});
+
+		term.on('resize', function(evt) {
+			websocket.send(new TextEncoder().encode("\x01" + JSON.stringify({cols: evt.cols, rows: evt.rows})))
+		});
+
+		term.on('title', function(title) {
+			document.title = title;
+		});
+
+		term.open(document.getElementById('xterm'));
+			term.fit();
+			websocket.onmessage = function(evt) {
+			if (evt.data instanceof ArrayBuffer) {
+				term.write(ab2str(evt.data));
+			} else {
+				alert(evt.data)
+			}
+		}
+
+		websocket.onclose = function(evt) {
+			term.write("Session terminated");
+			term.destroy();
+		}
+
+		websocket.onerror = function(evt) {
+			if (typeof console.log == "function") {
+				console.log(evt)
+			}
+		}
+	}
+	</script>
+</body>
+</html>
diff --git a/assets/main.css b/assets/main.css
@@ -0,0 +1,29 @@
+body {
+    font-family: helvetica, sans-serif, arial;
+    font-size: 1em;
+    color: #111;
+}
+
+#terminal-container {
+    width: 960px;
+    height: 600px;
+    margin: 0 auto;
+    padding: 2px;
+}
+
+#terminal-container .terminal {
+    background-color: #111;
+    color: #fafafa;
+    padding: 2px;
+}
+
+#terminal-container .terminal .terminal-cursor {
+    background-color: #fafafa;
+}
+
+/*
+.xterm-rows div {
+    height: 16px;
+}
+
+*/
diff --git a/main.go b/main.go
@@ -0,0 +1,143 @@
+package main
+
+import (
+	"encoding/json"
+	"flag"
+	"io"
+	"net/http"
+	"os"
+	"os/exec"
+	"strings"
+	"syscall"
+	"unsafe"
+
+	log "github.com/Sirupsen/logrus"
+	"github.com/gorilla/mux"
+	"github.com/gorilla/websocket"
+	"github.com/kr/pty"
+)
+
+type windowSize struct {
+	Rows uint16 `json:"rows"`
+	Cols uint16 `json:"cols"`
+	X    uint16
+	Y    uint16
+}
+
+var upgrader = websocket.Upgrader{
+	ReadBufferSize:  1024,
+	WriteBufferSize: 1024,
+}
+
+func handleWebsocket(w http.ResponseWriter, r *http.Request) {
+	l := log.WithField("remoteaddr", r.RemoteAddr)
+	conn, err := upgrader.Upgrade(w, r, nil)
+	if err != nil {
+		l.WithError(err).Error("Unable to upgrade connection")
+		return
+	}
+
+	cmd := exec.Command("/bin/bash", "-l")
+	cmd.Env = append(os.Environ(), "TERM=xterm")
+
+	tty, err := pty.Start(cmd)
+	if err != nil {
+		l.WithError(err).Error("Unable to start pty/cmd")
+		conn.WriteMessage(websocket.TextMessage, []byte(err.Error()))
+		return
+	}
+	defer tty.Close()
+
+	go func() {
+		defer conn.Close()
+		for {
+			buf := make([]byte, 1024)
+			read, err := tty.Read(buf)
+			if err != nil {
+				conn.WriteMessage(websocket.TextMessage, []byte(err.Error()))
+				l.WithError(err).Error("Unable to read from pty/cmd")
+				return
+			}
+			conn.WriteMessage(websocket.BinaryMessage, buf[:read])
+		}
+	}()
+
+	for {
+		messageType, reader, err := conn.NextReader()
+		if err != nil {
+			l.WithError(err).Error("Unable to grab next reader")
+			conn.WriteMessage(websocket.TextMessage, []byte(err.Error()))
+			return
+		}
+
+		if messageType == websocket.TextMessage {
+			l.Warn("Unexpected text message")
+			conn.WriteMessage(websocket.TextMessage, []byte("Unexpected text message"))
+			continue
+		}
+
+		dataTypeBuf := make([]byte, 1)
+		read, err := reader.Read(dataTypeBuf)
+		if err != nil {
+			l.WithError(err).Error("Unable to read message type from reader")
+			conn.WriteMessage(websocket.TextMessage, []byte("Unable to read message type from reader"))
+			return
+		}
+
+		if read != 1 {
+			l.WithField("bytes", read).Error("Unexpected number of bytes read")
+			return
+		}
+
+		switch dataTypeBuf[0] {
+		case 0:
+			copied, err := io.Copy(tty, reader)
+			if err != nil {
+				l.WithError(err).Errorf("Error after copying %d bytes", copied)
+			}
+		case 1:
+			decoder := json.NewDecoder(reader)
+			resizeMessage := windowSize{}
+			err := decoder.Decode(&resizeMessage)
+			if err != nil {
+				conn.WriteMessage(websocket.TextMessage, []byte("Error decoding resize message: "+err.Error()))
+				continue
+			}
+			log.WithField("resizeMessage", resizeMessage).Info("Resizing terminal")
+			_, _, errno := syscall.Syscall(
+				syscall.SYS_IOCTL,
+				tty.Fd(),
+				syscall.TIOCSWINSZ,
+				uintptr(unsafe.Pointer(&resizeMessage)),
+			)
+			if errno != 0 {
+				l.WithError(syscall.Errno(errno)).Error("Unable to resize terminal")
+			}
+		default:
+			l.WithField("dataType", dataTypeBuf[0]).Error("Unknown data type")
+		}
+	}
+}
+
+func main() {
+	var listen = flag.String("listen", "127.0.0.1:3000", "Host:port to listen on")
+	var assetsPath = flag.String("assets", "./assets", "Path to assets")
+
+	flag.Parse()
+
+	r := mux.NewRouter()
+
+	r.HandleFunc("/term", handleWebsocket)
+	r.PathPrefix("/").Handler(http.FileServer(http.Dir(*assetsPath)))
+
+	log.Info("Demo Websocket/Xterm terminal")
+	log.Warn("Warning, this is a completely insecure daemon that permits anyone to connect and control your computer, please don't run this anywhere")
+
+	if !(strings.HasPrefix(*listen, "127.0.0.1") || strings.HasPrefix(*listen, "localhost")) {
+		log.Warn("Danger Will Robinson - This program has no security built in and should not be exposed beyond localhost, you've been warned")
+	}
+
+	if err := http.ListenAndServe(*listen, r); err != nil {
+		log.WithError(err).Fatal("Something went wrong with the webserver")
+	}
+}