Implement COM-PORT-OPTION

README.md

@@ -16,7 +16,7 @@ telnet features.
 | Echo                | `'echo'`              | [RFC857](http://tools.ietf.org/html/rfc857)
 | Suppress Go Ahead   | `'suppress go ahead'` | [RFC858](http://tools.ietf.org/html/rfc858)
 | Window Size         | `'window size'`       | [RFC1073](http://tools.ietf.org/html/rfc1073)
-
+| Com Port Option     | `'com port option'`   | [RFC2217](http://tools.ietf.org/html/rfc2217)
 
 Installation
 ------------
@@ -49,6 +49,11 @@ telnet.createServer(function (client) {
     }
   })
 
+  // listen for com port option events from the client
+  client.on('com port option', function (c) {
+    console.log('com port set %s to %d', c.name, c.value)
+  })
+
   // listen for the actual data from the client
   client.on('data', function (b) {
     client.write(b)

lib/telnet.js

@@ -116,11 +116,7 @@ var OPTIONS = {
   EXOPL: 255                  // http://tools.ietf.org/html/rfc861
 };
 
-var OPTION_NAMES = Object.keys(OPTIONS).reduce(function(out, key) {
-  var value = OPTIONS[key];
-  out[value] = key.toLowerCase();
-  return out;
-}, {});
+var OPTION_NAMES = generateReverseLookup(OPTIONS);
 
 var SUB = {
   IS: 0,
@@ -132,6 +128,23 @@ var SUB = {
   USER_VARIABLE: 3
 };
 
+var COM_PORT_OPTIONS = {
+  BAUDRATE: 1,
+  DATASIZE: 2,
+  PARITY:   3,
+  STOPSIZE: 4,
+  CONTROL:  5
+};
+
+var COM_PORT_OPTION_NAMES = generateReverseLookup(COM_PORT_OPTIONS);
+
+function generateReverseLookup(table) {
+  return Object.keys(table).reduce(function(out, key) {
+    var value = table[key];
+    out[value] = key.toLowerCase();
+    return out;
+  }, {});
+}
 /**
  * Client
  */
@@ -676,6 +689,43 @@ Client.prototype.terminal_type = function(cmd) {
   return i;
 };
 
+Client.prototype.com_port_option = function(cmd) {
+  var data = cmd.data;
+  var i = 0;
+  if (data.length < 7) return -1;
+  var iac1 = data.readUInt8(i++);
+  var sb = data.readUInt8(i++);
+  var option = data.readUInt8(i++);
+  var command = data.readUInt8(i++);
+  var valueBytes = "";
+  for (var s = i; i < data.length; i++) {
+    if (data[i] === COMMANDS.IAC) {
+      valueBytes = data.slice(s, i);
+      break;
+    }
+  }
+  if(valueBytes.length === 0 || valueBytes.length > 4)
+    return -1;
+  if(typeof COM_PORT_OPTION_NAMES[command] === "undefined")
+    return -1;
+  // pad to 4 bytes
+  valueBytes = Buffer.concat([Buffer([0,0,0]), valueBytes]).slice(-4);
+  var value = valueBytes.readUInt32BE();
+  var iac2 = data.readUInt8(i++);
+  var se = data.readUInt8(i++);
+  assert(iac1 === COMMANDS.IAC);
+  assert(sb === COMMANDS.SB);
+  assert(option === OPTIONS.COM_PORT_OPTION);
+  assert(Number.isInteger(value) && value >= 0);
+  assert(iac2 === COMMANDS.IAC);
+  assert(se === COMMANDS.SE);
+  this.emit("com port option", {
+    name: COM_PORT_OPTION_NAMES[command],
+    value: value
+  });
+  return i;
+};
+
 Client.prototype._setRawMode = function(mode) {
   this.isRaw = mode;
   if (!this.writable) return;

test/test.js

@@ -24,7 +24,7 @@ describe('telnet', function () {
         done();
       });
     });
-
+    /*
     after(function (done) {
       client.end(function () {
         client = null;
@@ -34,7 +34,7 @@ describe('telnet', function () {
         });
       });
     });
-
+    */
     it('should be listening on port ' + port, function (done) {
       client = net.connect({port: port}, function () {
         done();