Merge pull request #190 from markandrus/crlf-keep-alive

Expand keep-alive support

Author: joseph-onsip

src/Transport.js

@@ -30,6 +30,9 @@ Transport = function(ua, server) {
   this.reconnectTimer = null;
   this.lastTransportError = {};
 
+  this.keepAliveInterval = ua.configuration.keepAliveInterval;
+  this.keepAliveTimer = null;
+
   this.ua.transport = this;
 
   // Connect
@@ -57,6 +60,38 @@ Transport.prototype = {
     }
   },
 
+  /**
+   * Send a keep-alive (a double-CRLF sequence).
+   * @private
+   * @returns {Boolean}
+   */
+  sendKeepAlive: function() {
+    return this.send('\r\n\r\n');
+  },
+
+  /**
+   * Start sending keep-alives.
+   * @private
+   */
+  startSendingKeepAlives: function() {
+    if (this.keepAliveInterval && !this.keepAliveTimer) {
+      this.keepAliveTimer = SIP.Timers.setTimeout(function() {
+        this.sendKeepAlive();
+        this.keepAliveTimer = null;
+        this.startSendingKeepAlives();
+      }.bind(this), computeKeepAliveTimeout(this.keepAliveInterval));
+    }
+  },
+
+  /**
+   * Stop sending keep-alives.
+   * @private
+   */
+  stopSendingKeepAlives: function() {
+    SIP.Timers.clearTimeout(this.keepAliveTimer);
+    this.keepAliveTimer = null;
+  },
+
   /**
   * Disconnect socket.
   */
@@ -65,6 +100,8 @@ Transport.prototype = {
       // Clear reconnectTimer
       SIP.Timers.clearTimeout(this.reconnectTimer);
 
+      this.stopSendingKeepAlives();
+
       this.closed = true;
       this.logger.log('closing WebSocket ' + this.server.ws_uri);
       this.ws.close();
@@ -146,6 +183,8 @@ Transport.prototype = {
     this.closed = false;
     // Trigger onTransportConnected callback
     this.ua.onTransportConnected(this);
+    // Start sending keep-alives
+    this.startSendingKeepAlives();
   },
 
   /**
@@ -158,6 +197,8 @@ Transport.prototype = {
     this.lastTransportError.code = e.code;
     this.lastTransportError.reason = e.reason;
 
+    this.stopSendingKeepAlives();
+
     if (this.reconnection_attempts > 0) {
       this.logger.log('Reconnection attempt ' + this.reconnection_attempts + ' failed (code: ' + e.code + (e.reason? '| reason: ' + e.reason : '') +')');
       this.reconnect();
@@ -302,6 +343,16 @@ Transport.prototype = {
   }
 };
 
+/**
+ * Compute an amount of time in seconds to wait before sending another
+ * keep-alive.
+ * @returns {Number}
+ */
+function computeKeepAliveTimeout(upperBound) {
+  var lowerBound = upperBound * 0.8;
+  return 1000 * (Math.random() * (upperBound - lowerBound) + lowerBound);
+}
+
 Transport.C = C;
 return Transport;
 };

src/UA.js

@@ -884,6 +884,8 @@ UA.prototype.loadConfig = function(configuration) {
       connectionRecoveryMinInterval: 2,
       connectionRecoveryMaxInterval: 30,
 
+      keepAliveInterval: 0,
+
       usePreloadedRoute: false,
 
       //string to be inserted into User-Agent request header
@@ -1114,6 +1116,7 @@ UA.configuration_skeleton = (function() {
       "authorizationUser",
       "connectionRecoveryMaxInterval",
       "connectionRecoveryMinInterval",
+      "keepAliveInterval",
       "displayName",
       "hackViaTcp", // false.
       "hackIpInContact", //false
@@ -1326,6 +1329,16 @@ UA.configuration_check = {
       }
     },
 
+    keepAliveInterval: function(keepAliveInterval) {
+      var value;
+      if (SIP.Utils.isDecimal(keepAliveInterval)) {
+        value = Number(keepAliveInterval);
+        if (value > 0) {
+          return value;
+        }
+      }
+    },
+
     noAnswerTimeout: function(noAnswerTimeout) {
       var value;
       if (SIP.Utils.isDecimal(noAnswerTimeout)) {