Remote Assistance on Chrome OS Part III - NativeMessageHost

chrome/browser/extensions/api/messaging/native_message_host_chromeos.cc

+// Copyright 2014 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 "extensions/browser/api/messaging/native_message_host.h"
+
+#include <string>
+
+#include "base/bind.h"
+#include "base/bind_helpers.h"
+#include "base/command_line.h"
+#include "base/json/json_reader.h"
+#include "base/json/json_writer.h"
+#include "base/location.h"
+#include "base/macros.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/message_loop/message_loop_proxy.h"
+#include "base/values.h"
+#include "chrome/browser/extensions/api/messaging/native_messaging_test_util.h"
+#include "extensions/common/constants.h"
+#include "extensions/common/url_pattern.h"
+#include "ui/gfx/native_widget_types.h"
+#include "url/gurl.h"
+
+namespace extensions {
+
+namespace {
+
+// A simple NativeMesageHost that echoes the received message. It is currently
+// used for testing.
+// TODO(kelvinp): Replace this class once Remote Assistance in process host
+// is implemented.
+
+const char* const kEchoHostOrigins[] = {
+    // ScopedTestNativeMessagingHost::kExtensionId
+    "chrome-extension://knldjmfmopnpolahpmmgbagdohdnhkik/"};
+
+class EchoHost : public NativeMessageHost {
+ public:
+  static scoped_ptr<NativeMessageHost> Create() {
+    return scoped_ptr<NativeMessageHost>(new EchoHost());
+  }
+
+  EchoHost() : message_number_(0), client_(NULL) {}
+
+  virtual void Start(Client* client) OVERRIDE {
+    client_ = client;
+  }
+
+  virtual void OnMessage(const std::string& request_string) OVERRIDE {
+    scoped_ptr<base::Value> request_value(
+        base::JSONReader::Read(request_string));
+    scoped_ptr<base::DictionaryValue> request(
+      static_cast<base::DictionaryValue*>(request_value.release()));
+    if (request_string.find("stopHostTest") != std::string::npos) {
+      client_->CloseChannel(kNativeHostExited);
+    } else if (request_string.find("bigMessageTest") != std::string::npos) {
+      client_->CloseChannel(kHostInputOuputError);
+    } else {
+      ProcessEcho(*request);
+    }
+  };
+
+  virtual scoped_refptr<base::SingleThreadTaskRunner> task_runner()
+      const OVERRIDE {
+    return base::MessageLoopProxy::current();
+  };
+
+ private:
+  void ProcessEcho(const base::DictionaryValue& request) {
+    scoped_ptr<base::DictionaryValue> response(new base::DictionaryValue());
+    response->SetInteger("id", ++message_number_);
+    response->Set("echo", request.DeepCopy());
+    response->SetString("caller_url", kEchoHostOrigins[0]);
+    std::string response_string;
+    base::JSONWriter::Write(response.get(), &response_string);
+    client_->PostMessageFromNativeHost(response_string);
+  }
+
+  int message_number_;
+  Client* client_;
+
+  DISALLOW_COPY_AND_ASSIGN(EchoHost);
+};
+
+struct BuiltInHost {
+  const char* const name;
+  const char* const* const allowed_origins;
+  int allowed_origins_count;
+  scoped_ptr<NativeMessageHost>(*create_function)();
+};
+
+// If you modify the list of allowed_origins, don't forget to update
+// remoting/host/it2me/com.google.chrome.remote_assistance.json.jinja2
+// to keep the two lists in sync.
+// TODO(kelvinp): Load the native messaging manifest as a resource file into
+// chrome and fetch the list of allowed_origins from the manifest.
+/*const char* const kRemotingIt2MeOrigins[] = {
+    "chrome-extension://ljacajndfccfgnfohlgkdphmbnpkjflk/",
+    "chrome-extension://gbchcmhmhahfdphkhkmpfmihenigjmpp/",
+    "chrome-extension://kgngmbheleoaphbjbaiobfdepmghbfah/",
+    "chrome-extension://odkaodonbgfohohmklejpjiejmcipmib/",
+    "chrome-extension://dokpleeekgeeiehdhmdkeimnkmoifgdd/",
+    "chrome-extension://ajoainacpilcemgiakehflpbkbfipojk/",
+    "chrome-extension://hmboipgjngjoiaeicfdifdoeacilalgc/"};*/
+
+static const BuiltInHost kBuiltInHost[] = {
+    {"com.google.chrome.test.echo", // ScopedTestNativeMessagingHost::kHostName
+     kEchoHostOrigins,
+     arraysize(kEchoHostOrigins),
+     &EchoHost::Create},
+};
+
+bool MatchesSecurityOrigin(const BuiltInHost& host,
+                           const std::string& extension_id) {
+  GURL origin(std::string(kExtensionScheme) + "://" + extension_id);
+  for (int i = 0; i < host.allowed_origins_count; i++) {
+    URLPattern allowed_origin(URLPattern::SCHEME_ALL, host.allowed_origins[i]);
+    if (allowed_origin.MatchesSecurityOrigin(origin)) {
+      return true;
+    }
+  }
+  return false;
+}
+
+}  // namespace
+
+scoped_ptr<NativeMessageHost> NativeMessageHost::Create(
+    gfx::NativeView native_view,
+    const std::string& source_extension_id,
+    const std::string& native_host_name,
+    bool allow_user_level,
+    std::string* error) {
+  for (unsigned int i = 0; i < arraysize(kBuiltInHost); i++) {
+    const BuiltInHost& host = kBuiltInHost[i];
+    std::string name(host.name);
+    if (name == native_host_name) {
+      if (MatchesSecurityOrigin(host, source_extension_id)) {
+        return (*host.create_function)();
+      }
+      *error = kForbiddenError;
+      return nullptr;
+    }
+  }
+  *error = kNotFoundError;
+  return nullptr;
+}
+
+}  // namespace extensions