error handling fixups

added some additional error handing functions and debugging points
- `DEBUG=ssh` will put the ssh2 module into debug mode
- `debug=WebSSH2` will output additional debug messages for functions
and events in the application (not including the ssh2 module debug)
- created socket/index.js to start the process of separating out app
functions, just holds error logging function at this point
- corrected some events on public/client.js so the primary error cause
is not overwritten
- ensure that ssh connection is terminated when websocked is
disconnected by the client

index.js

@@ -11,7 +11,9 @@ var path = require('path')
 var SSH = require('ssh2').Client
 var config = require('read-config')(path.join(__dirname, 'config.json'))
 var debug = require('debug')
+var debugWebSSH2 = debug('WebSSH2')
 var util = require('./util')
+var SocketUtil = require('./socket')
 var session = require('express-session')({
   secret: config.session.secret,
   name: config.session.name,
@@ -22,17 +24,7 @@ var termCols, termRows, myError
 // var LogPrefix
 // var dataBuffer = ''
 
-var expressOptions = {
+// server
-  dotfiles: 'ignore',
-  etag: false,
-  extensions: ['htm', 'html'],
-  index: false,
-  maxAge: '1s',
-  redirect: false,
-  setHeaders: function (res, path, stat) {
-    res.set('x-timestamp', Date.now())
-  }
-}
 
 server.listen({
   host: config.listen.ip,
@@ -51,17 +43,22 @@ server.on('error', function (err) {
   }
 })
 
+// express
+var expressOptions = {
+  dotfiles: 'ignore',
+  etag: false,
+  extensions: ['htm', 'html'],
+  index: false,
+  maxAge: '1s',
+  redirect: false,
+  setHeaders: function (res, path, stat) {
+    res.set('x-timestamp', Date.now())
+  }
+}
+
 app.use(session)
 app.use(util.basicAuth)
 
-io.use(function (socket, next) {
-  if (socket.request.res) {
-    session(socket.request, socket.request.res, next)
-  } else {
-    next()
-  }
-})
-
 app.disable('x-powered-by')
 
 app.use(express.static(path.join(__dirname, 'public'), expressOptions))
@@ -85,13 +82,32 @@ app.use('/src', express.static(path.join(__dirname, 'node_modules', 'xterm', 'di
 
 app.use('/addons', express.static(path.join(__dirname, 'node_modules', 'xterm', 'dist', 'addons')))
 
+app.use(function (req, res, next) {
+  res.status(404).send("Sorry can't find that!")
+})
+
+app.use(function (err, req, res, next) {
+  console.error(err.stack)
+  res.status(500).send('Something broke!')
+})
+
+// socket.io
+
+io.use(function (socket, next) {
+  if (socket.request.res) {
+    session(socket.request, socket.request.res, next)
+  } else {
+    next()
+  }
+})
+
 io.on('connection', function (socket) {
   // if websocket connection arrives without an express session, kill it
   if (!socket.request.session) {
     socket.disconnect(true)
     return
   }
-
+  var socketutil = new SocketUtil(socket, io)
   var conn = new SSH()
   socket.on('geometry', function (cols, rows) {
     termCols = cols
@@ -119,12 +135,9 @@ io.on('connection', function (socket) {
       rows: termRows
     }, function (err, stream) {
       if (err) {
-        console.log(err.message)
+        socketutil.SSHerror('EXEC ERROR' + err)
-        myError = err.message
+        conn.end()
-        socket.emit('status', 'SSH EXEC ERROR: ' + err.message)
+        return
-        socket.emit('statusBackground', 'red')
-        console.log('conn.shell err: ' + err.message)
-        return socket.close(true)
       }
       socket.on('data', function (data) {
         stream.write(data)
@@ -145,15 +158,24 @@ io.on('connection', function (socket) {
             console.log('controlData: ' + controlData)
         }
       })
+      
+      socket.on('disconnecting', function (reason) { debugWebSSH2('SOCKET DISCONNECTING: ' + reason) })
 
-      stream.on('data', function (d) {
+      socket.on('disconnect', function (reason) {
-        socket.emit('data', d.toString('binary'))
+        debugWebSSH2('SOCKET DISCONNECT: ' + reason)
+        err = { message: reason }
+        socketutil.SSHerror ('CLIENT SOCKET DISCONNECT', err)
+        conn.end()
       })
 
+      socket.on('error', function (error) { debugWebSSH2('SOCKET ERROR: ' + JSON.stringify(error)) })
+
+      stream.on('data', function (d) { socket.emit('data', d.toString('binary')) })
+
       stream.on('close', function (code, signal) {
-        console.log('Stream :: close :: code: ' + code + ', signal: ' + signal)
+        err = { message: ((code||signal) ? (((code)? 'CODE: ' + code: '') + ((code&&signal)? ' ':'') +  ((signal)? 'SIGNAL: ' + signal : '')) : undefined) }
+        socketutil.SSHerror('STREAM CLOSE', err)
         conn.end()
-        socket.disconnect()
       })
 
       stream.stderr.on('data', function (data) {
@@ -162,27 +184,12 @@ io.on('connection', function (socket) {
     })
   })
 
-  conn.on('end', function () {
+  conn.on('end', function (err) { socketutil.SSHerror('CONN END BY HOST', err) })
-    socket.emit('status', 'SSH CONNECTION CLOSED BY HOST ' + myError)
+  conn.on('close', function (err) { socketutil.SSHerror('CONN CLOSE', err) })
-    socket.emit('statusBackground', 'red')
+  conn.on('error', function (err) { socketutil.SSHerror('CONN ERROR', err ) })
-    socket.disconnect()
-  })
-
-  conn.on('close', function () {
-    socket.emit('status', 'SSH CONNECTION CLOSE ' + myError)
-    socket.emit('statusBackground', 'red')
-    socket.disconnect()
-  })
-
-  conn.on('error', function (err) {
-    myError = err
-    socket.emit('status', 'SSH CONNECTION ERROR ' + myError)
-    socket.emit('statusBackground', 'red')
-    console.error('conn.on(\'error\'): ' + myError)
-  })
 
   conn.on('keyboard-interactive', function (name, instructions, instructionsLang, prompts, finish) {
-    console.log('Connection :: keyboard-interactive')
+    debugWebSSH2('Connection :: keyboard-interactive')
     finish([socket.request.session.userpassword])
   })
   if (socket.request.session.username && socket.request.session.userpassword) {
@@ -197,7 +204,7 @@ io.on('connection', function (socket) {
         'cipher': ['aes128-cbc', '3des-cbc', 'aes256-cbc', 'aes128-ctr', 'aes192-ctr', 'aes256-ctr'],
         'hmac': ['hmac-sha1', 'hmac-sha1-96', 'hmac-md5-96']
       },
-      debug: debug('WebSSH2:debug')
+      debug: debug('ssh2')
     })
   } else {
     console.warn('Attempt to connect without session.username/password defined, potentially previously abandoned client session. disconnecting websocket client.\r\nHandshake information: \r\n  ' + JSON.stringify(socket.handshake))

public/client.js

@@ -1,5 +1,5 @@
 var sessionLogEnable = false
-var sessionLog, sessionFooter, logDate, currentDate, myFile
+var sessionLog, sessionFooter, logDate, currentDate, myFile, errorExists
 
 // replay password to server, requires
 function replayCredentials () {
@@ -84,6 +84,10 @@ socket.on('connect', function () {
     document.title = data
   }).on('status', function (data) {
     document.getElementById('status').innerHTML = data
+  }).on('ssherror', function (data) {
+    document.getElementById('status').innerHTML = data
+    document.getElementById('status').style.backgroundColor = 'red'
+    errorExists = true
   }).on('headerBackground', function (data) {
     document.getElementById('header').style.backgroundColor = data
   }).on('header', function (data) {
@@ -105,12 +109,16 @@ socket.on('connect', function () {
     if (sessionLogEnable) {
       sessionLog = sessionLog + data
     }
-  })// .on('disconnect', function (err) {
+  }).on('disconnect', function (err) {
-    // document.getElementById('status').style.backgroundColor = 'red'
+    if (!errorExists) {
-    // document.getElementById('status').innerHTML = 'WEBSOCKET SERVER DISCONNECTED' + err
+      document.getElementById('status').style.backgroundColor = 'red'
-    // socket.io.reconnection(false)
+      document.getElementById('status').innerHTML = 'WEBSOCKET SERVER DISCONNECTED: ' + err
-  // })//.on('error', function (err) {
+    }
-    // document.getElementById('status').style.backgroundColor = 'red'
+    socket.io.reconnection(false)
-    // document.getElementById('status').innerHTML = 'ERROR ' + err
+  }).on('error', function (err) {
-  // })
+    if (!errorExists) {
+      document.getElementById('status').style.backgroundColor = 'red'
+      document.getElementById('status').innerHTML = 'ERROR: ' + err
+    }
+  })
 })

socket/index.js

@@ -0,0 +1,11 @@
+var myError = myError
+
+module.exports = function (socket, io) {
+  this.SSHerror = function (myFunc, err) {
+    myError = (myError) ? myError : ((err) ? err.message:undefined)
+    thisError = (myError) ? ': ' + myError : ''
+    console.error('SSH ' + myFunc + thisError)
+   	socket.emit('ssherror', 'SSH ' + myFunc + thisError)
+   	socket.disconnect(true)
+  }
+}