mojo/dbus/dbus_external_service.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "mojo/dbus/dbus_external_service.h"
   6
   7 #include "base/bind.h"
   8 #include "base/callback.h"
   9 #include "base/logging.h"
  10 #include "base/memory/scoped_ptr.h"
  11 #include "base/message_loop/message_loop_proxy.h"
  12 #include "dbus/bus.h"
  13 #include "dbus/exported_object.h"
  14 #include "dbus/file_descriptor.h"
  15 #include "dbus/message.h"
  16 #include "dbus/object_path.h"
  17 #include "mojo/embedder/channel_init.h"
  18 #include "mojo/public/cpp/bindings/error_handler.h"
  19 #include "mojo/shell/external_service.mojom.h"
  20
  21 namespace mojo {
  22
  23 DBusExternalServiceBase::DBusExternalServiceBase(
  24     const std::string& service_name)
  25     : service_name_(service_name),
  26       exported_object_(NULL) {
  27 }
  28 DBusExternalServiceBase::~DBusExternalServiceBase() {}
  29
  30 void DBusExternalServiceBase::Start() {
  31   InitializeDBus();
  32   ExportMethods();
  33   TakeDBusServiceOwnership();
  34   DVLOG(1) << "External service started";
  35 }
  36
  37 void DBusExternalServiceBase::ConnectChannel(
  38     dbus::MethodCall* method_call,
  39     dbus::ExportedObject::ResponseSender sender) {
  40   dbus::MessageReader reader(method_call);
  41   dbus::FileDescriptor wrapped_fd;
  42   if (!reader.PopFileDescriptor(&wrapped_fd)) {
  43     sender.Run(
  44         dbus::ErrorResponse::FromMethodCall(
  45             method_call,
  46             "org.chromium.Mojo.BadHandle",
  47             "Invalid FD.").PassAs<dbus::Response>());
  48     return;
  49   }
  50   wrapped_fd.CheckValidity();
  51   channel_init_.reset(new mojo::embedder::ChannelInit);
  52   mojo::ScopedMessagePipeHandle message_pipe =
  53       channel_init_->Init(wrapped_fd.TakeValue(),
  54                           base::MessageLoopProxy::current());
  55   CHECK(message_pipe.is_valid());
  56
  57   Connect(message_pipe.Pass());
  58   sender.Run(dbus::Response::FromMethodCall(method_call));
  59 }
  60
  61 void DBusExternalServiceBase::ExportMethods() {
  62   CHECK(exported_object_);
  63   CHECK(exported_object_->ExportMethodAndBlock(
  64       kMojoDBusInterface, kMojoDBusConnectMethod,
  65       base::Bind(&DBusExternalServiceBase::ConnectChannel,
  66                  base::Unretained(this))));
  67 }
  68
  69 void DBusExternalServiceBase::InitializeDBus() {
  70   CHECK(!bus_.get());
  71   dbus::Bus::Options options;
  72   options.bus_type = dbus::Bus::SESSION;
  73   bus_ = new dbus::Bus(options);
  74   CHECK(bus_->Connect());
  75   CHECK(bus_->SetUpAsyncOperations());
  76
  77   exported_object_ =
  78       bus_->GetExportedObject(dbus::ObjectPath(kMojoDBusImplPath));
  79 }
  80
  81 void DBusExternalServiceBase::TakeDBusServiceOwnership() {
  82   CHECK(bus_->RequestOwnershipAndBlock(
  83       service_name_,
  84       dbus::Bus::REQUIRE_PRIMARY_ALLOW_REPLACEMENT))
  85       << "Unable to take ownership of " << service_name_;
  86 }
  87
  88 }  // namespace mojo