* Bugfix: ftp source was not calling back on error

* Refactored ftp source
* ftp source will not consider 6xx as errors (which is more compliant with return code specifications)

lib/sources/ftp.js

@@ -4,36 +4,54 @@
 
 var net = require('net');
 
-var Ftp = function (service, stream) {
+var Ftp = function (service, stream, callback) {
   this.service = service;
   this.stream = stream;
-};
 
-Ftp.prototype.error = function(status, message) {
-  this.service.status = "down";
-  this.service.statusCode = status;
-  this.service.message = message;
-  callback(this.service.status, this.service);
+  /**
+    Actually required to get the SERVER READY out of the way
+    I am also assuming this might catch potential
+    on-connection ftp error
+    codes...
+  */
+  this.command('', callback);
 };
 
 Ftp.prototype.command = function(command, callback) {
 
-  var self = this;
   this.stream.write(command + '\r\n');
 
-  var dataCallback = function(data) {
-    self.stream.removeListener('data', dataCallback);
+  this.stream.once('data', function(data) {
 
     var status = data.toString().match(/^\d\d\d/);
 
-    if (parseInt(status[0], 10) > 399) {
-      ftp.error(self.service, status[0], data.toString());
-    } else {
-      return callback(data);
+    status = status[0] ? parseInt(status[0], 10) : 0;
+
+    /**
+      TODO?
+
+      4xx and 5xx should be treated differently. 4xx should be critical,
+      while 5xx should be (potentially) considered as down
+
+      Removed 600 from potential error responses
+    */
+    if ((status > 399 && status < 600) || status > 999) {
+      return callback(status, data.toString());
     }
-  };
 
-  self.stream.addListener('data', dataCallback);
+    return callback(null, data.toString());
+  });
+};
+
+Ftp.prototype.returnServiceStatus = function(service, status, statusCode, message, callback) {
+  service.status = status;
+  service.statusCode = statusCode;
+  service.message = message;
+
+  this.stream.end();
+  this.stream.destroy();
+
+  callback(service.status, service);
 };
 
 exports.check = function(serviceDefinition, service, callback) {
@@ -45,22 +63,35 @@ exports.check = function(serviceDefinition, service, callback) {
   var stream = net.createConnection(serviceDefinition.port, serviceDefinition.host);
 
   stream.addListener('connect', function () {
-    var ftp = new Ftp(service, stream);
-
-    ftp.command('USER ' + service.username, function(data) {
-      ftp.command('PASS ' + service.password, function(data) {
-        service.status = "up";
-        service.statusCode = 0;
-        service.message = "";
-        callback(service.status, service);
+
+    var ftp = new Ftp(service, stream, function (err, data) {
+
+      if (err) {
+        return ftp.returnServiceStatus(service, 'down', err, data, callback);
+      }
+
+      ftp.command('USER ' + serviceDefinition.username, function(err, data) {
+
+        if (err) {
+          return ftp.returnServiceStatus(service, 'critical', err, data, callback);
+        }
+
+        ftp.command('PASS ' + serviceDefinition.password, function(err, data) {
+          if (err) {
+            return ftp.returnServiceStatus(service, 'critical', err, data, callback);
+          }
+
+          return ftp.returnServiceStatus(service, 'up', 0, '', callback);
+        });
       });
     });
   });
 
   stream.addListener('error', function (e) {
-    service.status = "down";
+    service.status = 'down';
     service.statusCode = 0;
     service.message = e.message;
-    callback(service.status, service);
+
+    return callback(service.status, service);
   });
 };