entd: require a per-entd-invocation session id in every request

callback_server.h

 // Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // The callback server listens for http connections on port 5199 (by default),
 // and dispatches valid requests to javascript function registered by the
 // policy.
 //
 // The incoming request must be an HTTP POST (libevent doesn't have an https
 // server) to the uri "/dispatch".  It must have a content-type of
@@ skipping 37 matching lines @@
   static void SetTemplateBindings(
       v8::Handle<v8::ObjectTemplate> template_object);
 
   // Initialize the CallbackServer instance.  Must be called before any
   // other method.
   virtual bool Initialize() {
     JSObjectWrapper<CallbackServer>::Initialize();
     return true;
   }
 
-  virtual std::string request_header_value() {
-    return request_header_value_;
-  }
-
-  virtual void set_request_header_value(std::string value) {
-    request_header_value_ = value;
-  }
-
   // Start the callback server with a particular set of callbacks and
   // on a given port number.
   virtual bool Start(v8::Handle<v8::Object> callbacks, int port);
 
   // Stop the server.
   virtual void Stop();
 
   // Return true if the callback server has been started.
   virtual bool IsRunning();
 
   // Dispatch a given http request.
   virtual void OnRequest(struct evhttp_request* request);
 
   // Sets whether or not the server is busy.  While busy, it cannot be stopped.
   // This should only matter when someone attempts to stop the server from
   // script during a callback.  In other cases, the single threadedness of
   // entd should keep us from ever trying to stop while busy.  This is not
   // nestable.
   virtual void SetBusy(bool state) {
     if (state == busy_)
       LOG(WARNING) << "Busy status is already " << (state ? "set" : "clear");
     busy_ = state;
   };
   virtual bool IsBusy() { return busy_; }
 
+  static void set_session_id(const std::string& session_id) {
+    session_id_ = session_id;
+  }
+
+  static std::string session_id() {
+    return session_id_;
+  }
+
   static std::string required_origin;
 
  private:
   // State for SetBusy/IsBusy.
   bool busy_;
 
   // Parent entd object.
   Entd* entd_;
 
   // JS Object containing the callback functions we might dispatch to.
   v8::Persistent<v8::Object> callbacks_;
 
-  // The value required in the X-Entd-Request header.
-  std::string request_header_value_;
+  // X-Entd-Session-Id that must come in every request.
+  static std::string session_id_;
 
   // Non-null if the server is running.
   struct evhttp* evhttp_;
 
   // Port we're listening on, or 0 if not running.
   int port_;
 
   DISALLOW_COPY_AND_ASSIGN(CallbackServer);
 };
 
 }  // namespace entd
 
 #endif  // ENTD_CALLBACK_SERVER_H_