ppapi: PPB_VpnProvider: Add a simple NaCl SDK example.

native_client_sdk/src/examples/api/vpn_provider/vpn_provider.cc

Index: native_client_sdk/src/examples/api/vpn_provider/vpn_provider.cc
diff --git a/native_client_sdk/src/examples/api/vpn_provider/vpn_provider.cc b/native_client_sdk/src/examples/api/vpn_provider/vpn_provider.cc
new file mode 100644
index 0000000000000000000000000000000000000000..88e5aaa3d70b6df1530aec8baf06e7b6423099ce
--- /dev/null
+++ b/native_client_sdk/src/examples/api/vpn_provider/vpn_provider.cc
@@ -0,0 +1,137 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <queue>
+#include <sstream>
+#include <string>
+
+#include "ppapi/cpp/instance.h"
+#include "ppapi/cpp/module.h"
+#include "ppapi/cpp/var.h"
+#include "ppapi/cpp/var_dictionary.h"
+
+#include "vpn_provider_helper.h"
+
+class VpnProviderInstance : public pp::Instance {
+ public:
+  explicit VpnProviderInstance(PP_Instance instance)
+      : pp::Instance(instance), vpn_provider_helper_(this) {
+    vpn_provider_helper_.Init();
+  }
+
+  virtual ~VpnProviderInstance() {}
+
+  // Handles messages from Javascript
+  virtual void HandleMessage(const pp::Var& message) {
+    // Expecting only dictionary messages from JS.
+    if (!message.is_dictionary()) {
+      PostMessage(
+          "NaCl: VpnProviderInstance::HandleMessage: "
+          "Unexpected message. Not a dictionary.");
+      return;
+    }
+
+    // Message type defined by 'cmd' key.
+    pp::VarDictionary dict(message);
+
+    std::string command;
+    if (!GetStringFromMessage(dict, "cmd", &command)) {
+      return;
+    }
+    if (command == "bind") {
+      std::string name, id;
+      if (!GetStringFromMessage(dict, "name", &name) ||
+          !GetStringFromMessage(dict, "id", &id)) {
+        return;
+      }
+      PostMessage(
+          "NaCl: VpnProviderInstance::HandleMessage: "
+          "Bind request.");
+      vpn_provider_helper_.Bind(name, id);
+      return;
+    }
+
+    if (command == "connected") {
+      PostMessage(
+          "NaCl: VpnProviderInstance::HandleMessage: "
+          "Connect request.");
+
+      /* This is the place where the developer would establing the VPN
+       * connection. The response would usually contain configuration details
+       * for the tunnel obtained from the VPN implementation.
+       *
+       * Currently just signaling that is was executed succesfuly.
+       */
+
+      pp::VarDictionary dict;
+      dict.Set("cmd", "setParameters");
+      PostMessage(dict);
+      return;
+    }
+
+    if (command == "disconnected") {
+      PostMessage(
+          "NaCl: VpnProviderInstance::HandleMessage: "
+          "Disconnect request.");
+
+      /* This is the place where the developer would disconnect from the VPN
+       * connection.
+       */
+
+      return;
+    }
+
+    PostMessage(
+        "NaCl: VpnProviderInstance::HandleMessage: "
+        "Unexpected command.");
+  }
+
+ private:
+  // Helper function for HandleMessage
+  bool GetStringFromMessage(const pp::VarDictionary& dict,
+                            const char* key,
+                            std::string* value) {
+    if (!value)
+      return false;
+
+    pp::Var val = dict.Get(key);
+    if (val.is_undefined()) {
+      std::stringstream ss;
+      ss << "NaCl: VpnProviderInstance::HandleMessage: Malformed message. No '"
+         << key << "' key.";
+      PostMessage(ss.str());
+      return false;
+    }
+    if (!val.is_string()) {
+      std::stringstream ss;
+      ss << "NaCl: VpnProviderInstance::HandleMessage: Malformed message. ";
+      ss << "Type for key '" << key << "' is not string";
+      PostMessage(ss.str());
+      return false;
+    }
+
+    *value = val.AsString();
+    return true;
+  }
+
+  VpnProviderHelper vpn_provider_helper_;
+};
+
+class VpnProviderModule : public pp::Module {
+ public:
+  VpnProviderModule() : pp::Module() {}
+  virtual ~VpnProviderModule() {}
+
+  virtual pp::Instance* CreateInstance(PP_Instance instance) {
+    return new VpnProviderInstance(instance);
+  }
+};
+
+namespace pp {
+
+Module* CreateModule() {
+  return new VpnProviderModule();
+}
+
+}  // namespace pp