broker_messages.h 2.6 KB

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  1. // Copyright 2016 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. #ifndef MOJO_CORE_BROKER_MESSAGES_H_
  5. #define MOJO_CORE_BROKER_MESSAGES_H_
  6. #include "build/build_config.h"
  7. #include "mojo/core/channel.h"
  8. namespace mojo {
  9. namespace core {
  10. #pragma pack(push, 1)
  11. enum BrokerMessageType : uint32_t {
  12. INIT,
  13. BUFFER_REQUEST,
  14. BUFFER_RESPONSE,
  15. };
  16. struct BrokerMessageHeader {
  17. BrokerMessageType type;
  18. uint32_t padding;
  19. };
  20. static_assert(IsAlignedForChannelMessage(sizeof(BrokerMessageHeader)),
  21. "Invalid header size.");
  22. struct BufferRequestData {
  23. uint32_t size;
  24. };
  25. struct BufferResponseData {
  26. uint64_t guid_high;
  27. uint64_t guid_low;
  28. };
  29. #if BUILDFLAG(IS_WIN)
  30. struct InitData {
  31. // NOTE: InitData in the payload is followed by string16 data with exactly
  32. // |pipe_name_length| wide characters (i.e., |pipe_name_length|*2 bytes.)
  33. // This applies to Windows only.
  34. uint32_t pipe_name_length;
  35. };
  36. #endif
  37. #pragma pack(pop)
  38. template <typename T>
  39. inline bool GetBrokerMessageData(Channel::Message* message, T** out_data) {
  40. const size_t required_size = sizeof(BrokerMessageHeader) + sizeof(T);
  41. if (message->payload_size() < required_size)
  42. return false;
  43. auto* header = static_cast<BrokerMessageHeader*>(message->mutable_payload());
  44. *out_data = reinterpret_cast<T*>(header + 1);
  45. return true;
  46. }
  47. template <typename T>
  48. inline Channel::MessagePtr CreateBrokerMessage(
  49. BrokerMessageType type,
  50. size_t num_handles,
  51. size_t extra_data_size,
  52. T** out_message_data,
  53. void** out_extra_data = nullptr) {
  54. const size_t message_size = sizeof(BrokerMessageHeader) +
  55. sizeof(**out_message_data) + extra_data_size;
  56. Channel::MessagePtr message =
  57. Channel::Message::CreateMessage(message_size, num_handles);
  58. BrokerMessageHeader* header =
  59. reinterpret_cast<BrokerMessageHeader*>(message->mutable_payload());
  60. header->type = type;
  61. header->padding = 0;
  62. *out_message_data = reinterpret_cast<T*>(header + 1);
  63. if (out_extra_data)
  64. *out_extra_data = *out_message_data + 1;
  65. return message;
  66. }
  67. inline Channel::MessagePtr CreateBrokerMessage(
  68. BrokerMessageType type,
  69. size_t num_handles,
  70. std::nullptr_t** dummy_out_data) {
  71. Channel::MessagePtr message =
  72. Channel::Message::CreateMessage(sizeof(BrokerMessageHeader), num_handles);
  73. BrokerMessageHeader* header =
  74. reinterpret_cast<BrokerMessageHeader*>(message->mutable_payload());
  75. header->type = type;
  76. header->padding = 0;
  77. return message;
  78. }
  79. } // namespace core
  80. } // namespace mojo
  81. #endif // MOJO_CORE_BROKER_MESSAGES_H_