Add FileTransferMessageHandlerFactory and file transfer capability

Bug: 
Change-Id: Iff14def9c9e2e8920ce9b13f1ec17dc50d1a4a86
Reviewed-on: https://chromium-review.googlesource.com/596614
Commit-Queue: Joseph Arhar <jarhar@google.com>
Reviewed-by: Joe Downing <joedow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#491609}

remoting/host/BUILD.gn

@@ -137,6 +137,8 @@ static_library("host") {
     "dns_blackhole_checker.h",
     "evaluate_capability.cc",
     "evaluate_capability.h",
+    "file_transfer_message_handler_factory.cc",
+    "file_transfer_message_handler_factory.h",
     "forward_process_stats_agent.cc",
     "forward_process_stats_agent.h",
     "gcd_rest_client.cc",
@@ -536,16 +538,20 @@ source_set("unit_tests") {
   }
 
   if (enable_me2me_host) {
-    sources += [
-      "evaluate_capability_unittest.cc",
-    ]
+    sources += [ "evaluate_capability_unittest.cc" ]
 
     if (is_win) {
-      data_deps = [ "//remoting/host/win:remoting_me2me_host" ]
+      data_deps = [
+        "//remoting/host/win:remoting_me2me_host",
+      ]
     } else if (is_mac) {
-      data_deps = [ "//remoting/host/mac:remoting_me2me_host" ]
+      data_deps = [
+        "//remoting/host/mac:remoting_me2me_host",
+      ]
     } else {
-      data_deps = [ ":remoting_me2me_host" ]
+      data_deps = [
+        ":remoting_me2me_host",
+      ]
     }
   }
 }

remoting/host/client_session.cc

@@ -25,6 +25,7 @@
 #include "remoting/proto/control.pb.h"
 #include "remoting/proto/event.pb.h"
 #include "remoting/protocol/audio_stream.h"
+#include "remoting/protocol/capability_names.h"
 #include "remoting/protocol/client_stub.h"
 #include "remoting/protocol/clipboard_thread_proxy.h"
 #include "remoting/protocol/pairing_registry.h"
@@ -181,6 +182,13 @@ void ClientSession::SetCapabilities(
   extension_manager_->OnNegotiatedCapabilities(
       connection_->client_stub(), capabilities_);
 
+  if (HasCapability(capabilities_, protocol::kFileTransferCapability)) {
+    data_channel_manager_.RegisterCreateHandlerCallback(
+        kFileTransferDataChannelPrefix,
+        base::Bind(&FileTransferMessageHandlerFactory::CreateDataChannelHandler,
+                   base::Unretained(&file_transfer_message_handler_factory_)));
+  }
+
   VLOG(1) << "Client capabilities: " << *client_capabilities_;
 
   desktop_environment_->SetCapabilities(capabilities_);

remoting/host/client_session.h

@@ -19,6 +19,7 @@
 #include "remoting/host/client_session_control.h"
 #include "remoting/host/client_session_details.h"
 #include "remoting/host/desktop_environment_options.h"
+#include "remoting/host/file_transfer_message_handler_factory.h"
 #include "remoting/host/host_experiment_session_plugin.h"
 #include "remoting/host/host_extension_session_manager.h"
 #include "remoting/host/remote_input_filter.h"
@@ -240,6 +241,9 @@ class ClientSession : public protocol::HostStub,
   // Used to dispatch new data channels to factory methods.
   protocol::DataChannelManager data_channel_manager_;
 
+  // Used to handle file transfer data channels.
+  FileTransferMessageHandlerFactory file_transfer_message_handler_factory_;
+
   // Set to true if the client was authenticated successfully.
   bool is_authenticated_ = false;
 

remoting/host/file_transfer_message_handler_factory.cc

+// Copyright 2017 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 "remoting/host/file_transfer_message_handler_factory.h"
+
+namespace remoting {
+
+FileTransferMessageHandlerFactory::FileTransferMessageHandlerFactory() =
+    default;
+FileTransferMessageHandlerFactory::~FileTransferMessageHandlerFactory() =
+    default;
+
+void FileTransferMessageHandlerFactory::CreateDataChannelHandler(
+    const std::string& channel_name,
+    std::unique_ptr<protocol::MessagePipe> pipe) {
+  // TODO(jarhar): Implement FileTransferMessageHandler and pass pipe to it.
+}
+
+}  // namespace remoting

remoting/host/file_transfer_message_handler_factory.h

+// Copyright 2017 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.
+
+#ifndef REMOTING_HOST_FILE_TRANSFER_MESSAGE_HANDLER_FACTORY_H_
+#define REMOTING_HOST_FILE_TRANSFER_MESSAGE_HANDLER_FACTORY_H_
+
+#include <memory>
+#include <string>
+
+#include "remoting/protocol/message_pipe.h"
+
+namespace remoting {
+
+constexpr char kFileTransferDataChannelPrefix[] = "filetransfer-";
+
+class FileTransferMessageHandlerFactory final {
+ public:
+  FileTransferMessageHandlerFactory();
+  ~FileTransferMessageHandlerFactory();
+
+  void CreateDataChannelHandler(const std::string& channel_name,
+                                std::unique_ptr<protocol::MessagePipe> pipe);
+};
+
+}  // namespace remoting
+
+#endif  // REMOTING_HOST_FILE_TRANSFER_MESSAGE_HANDLER_FACTORY_H_

remoting/host/me2me_desktop_environment.cc

@@ -56,6 +56,14 @@ std::string Me2MeDesktopEnvironment::GetCapabilities() const {
     capabilities += " ";
     capabilities += protocol::kTouchEventsCapability;
   }
+
+// TODO(jarhar): Replace this ifdef with settings in DesktopEnvironmentOptions,
+//               and then a chrome policy.
+#ifdef CHROME_REMOTE_DESKTOP_FILE_TRANSFER_ENABLED
+  capabilities += " ";
+  capabilities += protocol::kFileTransferCapability;
+#endif
+
   return capabilities;
 }
 

remoting/protocol/capability_names.h

@@ -14,6 +14,8 @@ const char kTouchEventsCapability[] = "touchEvents";
 const char kSendInitialResolution[] = "sendInitialResolution";
 const char kRateLimitResizeRequests[] = "rateLimitResizeRequests";
 
+const char kFileTransferCapability[] = "fileTransfer";
+
 }  // namespace protocol
 }  // namespace remoting