ipc/attachment_broker_unprivileged_mac.cc

// Copyright 2015 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 "ipc/attachment_broker_unprivileged_mac.h"

#include <mach/mach.h>

#include "base/mac/mach_port_util.h"
#include "base/mac/scoped_mach_port.h"
#include "base/process/process.h"
#include "ipc/attachment_broker_messages.h"
#include "ipc/brokerable_attachment.h"
#include "ipc/ipc_sender.h"
#include "ipc/mach_port_attachment_mac.h"

namespace IPC {

AttachmentBrokerUnprivilegedMac::AttachmentBrokerUnprivilegedMac() {}

AttachmentBrokerUnprivilegedMac::~AttachmentBrokerUnprivilegedMac() {}

bool AttachmentBrokerUnprivilegedMac::SendAttachmentToProcess(
    const scoped_refptr<IPC::BrokerableAttachment>& attachment,
    base::ProcessId destination_process) {
  switch (attachment->GetBrokerableType()) {
    case BrokerableAttachment::MACH_PORT: {
      internal::MachPortAttachmentMac* mach_port_attachment =
          static_cast<internal::MachPortAttachmentMac*>(attachment.get());
      internal::MachPortAttachmentMac::WireFormat format =
          mach_port_attachment->GetWireFormat(destination_process);
      bool success =
          get_sender()->Send(new AttachmentBrokerMsg_DuplicateMachPort(format));
      if (success)
        mach_port_attachment->reset_mach_port_ownership();
      return success;
    }
    default:
      NOTREACHED();
      return false;
  }
  return false;
}

bool AttachmentBrokerUnprivilegedMac::OnMessageReceived(const Message& msg) {
  bool handled = true;
  IPC_BEGIN_MESSAGE_MAP(AttachmentBrokerUnprivilegedMac, msg)
    IPC_MESSAGE_HANDLER(AttachmentBrokerMsg_MachPortHasBeenDuplicated,
                        OnMachPortHasBeenDuplicated)
    IPC_MESSAGE_UNHANDLED(handled = false)
  IPC_END_MESSAGE_MAP()
  return handled;
}

void AttachmentBrokerUnprivilegedMac::OnMachPortHasBeenDuplicated(
    const IPC::internal::MachPortAttachmentMac::WireFormat& wire_format) {
  // The IPC message was intended for a different process. Ignore it.
  if (wire_format.destination_process != base::Process::Current().Pid()) {
    // If everything is functioning correctly, this path should not be taken.
    // However, it's still important to validate all fields of the IPC message.
    LogError(WRONG_DESTINATION);
    return;
  }

  base::mac::ScopedMachReceiveRight message_port(wire_format.mach_port);
  base::mac::ScopedMachSendRight memory_object(
      base::ReceiveMachPort(message_port.get()));

  LogError(memory_object.get() == MACH_PORT_NULL ? ERR_RECEIVE_MACH_MESSAGE
                                                 : SUCCESS);

  IPC::internal::MachPortAttachmentMac::WireFormat translated_wire_format(
      memory_object.release(), wire_format.destination_process,
      wire_format.attachment_id);

  scoped_refptr<BrokerableAttachment> attachment(
      new IPC::internal::MachPortAttachmentMac(translated_wire_format));
  HandleReceivedAttachment(attachment);
}

}  // namespace IPC