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
5 #ifndef MOJO_CORE_BROKER_MESSAGES_H_
6 #define MOJO_CORE_BROKER_MESSAGES_H_
7
8 #include "build/build_config.h"
9 #include "mojo/core/channel.h"
10
11 namespace mojo {
12 namespace core {
13
14 #pragma pack(push, 1)
15
16 enum BrokerMessageType : uint32_t {
17 INIT,
18 BUFFER_REQUEST,
19 BUFFER_RESPONSE,
20 };
21
22 struct BrokerMessageHeader {
23 BrokerMessageType type;
24 uint32_t padding;
25 };
26
27 static_assert(IsAlignedForChannelMessage(sizeof(BrokerMessageHeader)),
28 "Invalid header size.");
29
30 struct BufferRequestData {
31 uint32_t size;
32 };
33
34 struct BufferResponseData {
35 uint64_t guid_high;
36 uint64_t guid_low;
37 };
38
39 #if defined(OS_WIN)
40 struct InitData {
41 // NOTE: InitData in the payload is followed by string16 data with exactly
42 // |pipe_name_length| wide characters (i.e., |pipe_name_length|*2 bytes.)
43 // This applies to Windows only.
44 uint32_t pipe_name_length;
45 };
46 #endif
47
48 #pragma pack(pop)
49
50 template <typename T>
GetBrokerMessageData(Channel::Message * message,T ** out_data)51 inline bool GetBrokerMessageData(Channel::Message* message, T** out_data) {
52 const size_t required_size = sizeof(BrokerMessageHeader) + sizeof(T);
53 if (message->payload_size() < required_size)
54 return false;
55
56 auto* header = static_cast<BrokerMessageHeader*>(message->mutable_payload());
57 *out_data = reinterpret_cast<T*>(header + 1);
58 return true;
59 }
60
61 template <typename T>
62 inline Channel::MessagePtr CreateBrokerMessage(
63 BrokerMessageType type,
64 size_t num_handles,
65 size_t extra_data_size,
66 T** out_message_data,
67 void** out_extra_data = nullptr) {
68 const size_t message_size = sizeof(BrokerMessageHeader) +
69 sizeof(**out_message_data) + extra_data_size;
70 Channel::MessagePtr message(new Channel::Message(message_size, num_handles));
71 BrokerMessageHeader* header =
72 reinterpret_cast<BrokerMessageHeader*>(message->mutable_payload());
73 header->type = type;
74 header->padding = 0;
75 *out_message_data = reinterpret_cast<T*>(header + 1);
76 if (out_extra_data)
77 *out_extra_data = *out_message_data + 1;
78 return message;
79 }
80
CreateBrokerMessage(BrokerMessageType type,size_t num_handles,std::nullptr_t ** dummy_out_data)81 inline Channel::MessagePtr CreateBrokerMessage(
82 BrokerMessageType type,
83 size_t num_handles,
84 std::nullptr_t** dummy_out_data) {
85 Channel::MessagePtr message(
86 new Channel::Message(sizeof(BrokerMessageHeader), num_handles));
87 BrokerMessageHeader* header =
88 reinterpret_cast<BrokerMessageHeader*>(message->mutable_payload());
89 header->type = type;
90 header->padding = 0;
91 return message;
92 }
93
94 } // namespace core
95 } // namespace mojo
96
97 #endif // MOJO_CORE_BROKER_MESSAGES_H_
98