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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 | |
5 #ifndef COMPONENTS_PROXIMITY_AUTH_BLE_BLUETOOTH_LOW_ENERGY_WEAVE_PACKET_RECEIVER
_H_ | |
6 #define COMPONENTS_PROXIMITY_AUTH_BLE_BLUETOOTH_LOW_ENERGY_WEAVE_PACKET_RECEIVER
_H_ | |
7 | |
8 #include <stdint.h> | |
9 | |
10 #include <memory> | |
11 #include <string> | |
12 #include <vector> | |
13 | |
14 #include "build/build_config.h" | |
15 #include "components/proximity_auth/ble/bluetooth_low_energy_weave_defines.h" | |
16 | |
17 namespace proximity_auth { | |
18 namespace weave { | |
19 | |
20 // Receive the messages sent with uWeave protocol. | |
21 // Example Usage: | |
22 // State state = ReceivePacket(packet); | |
23 // switch (state) { | |
24 // case ReceiverState::DATA_READY: | |
25 // OnBytesReceived(GetDataMessage()); | |
26 // break; | |
27 // case ReceiverState::CONNECTION_CLOSED: | |
28 // Disconnect(GetReasonForClose()); | |
29 // break; | |
30 // case ReceiverState::ERROR: | |
31 // HandleError(GetReasonToClose()); | |
32 // break; | |
33 // case ReceiverState::CONNECTING: | |
34 // case ReceiverState::WAITING: | |
35 // case ReceiverState::RECEIVING_DATA: | |
36 // break; | |
37 // default: | |
38 // FoundABugInReceiver(); | |
39 // break; | |
40 // } | |
41 class BluetoothLowEnergyWeavePacketReceiver { | |
42 public: | |
43 enum ReceiverType { CLIENT, SERVER }; | |
44 | |
45 // CONNECTING: | |
46 // The connection hasn't been estabalished. Accept a CONNECTION_REQUEST if | |
47 // the receiver is a SERVER. Accept a CONNECTION_RESPONSE if the receiver is | |
48 // a CLIENT. All other packets cause the receiver to move into ERROR state. | |
49 // The state will transition to WAITING after a request/response if they | |
50 // do not have extra data. The state will transition to DATA_READY if the | |
51 // request/response have extra data since the extra data is treated as a | |
52 // complete data message. This state is never reentered. | |
53 // WAITING: | |
54 // The reciever is ready but doesn't have any data. It's waiting for packet | |
55 // to arrive. Will accept all but connection request/response packets. The | |
56 // first data packet will move the receiver to the RECEIVING_DATA state. A | |
57 // connection close packet will move the receiver to the CONNECTION_CLOSED | |
58 // state. This state is also never reentered. | |
59 // RECEIVING_DATA: | |
60 // The receiver is in middle of receiving a data message consisted of | |
61 // multiple packets. Will receive only data packets. The last data packet | |
62 // will move the receiver into DATA_READY state. This state can be entered | |
63 // once from WAITING and unlimited number of times from DATA_READY. | |
64 // DATA_READY: | |
65 // The data message is ready to be retrieved. If the data is not retrieved | |
66 // before the next packet which will cause a transition, the data will be | |
67 // lost. Move to RECEIVING_DATA on receiving first data packet. Move to | |
68 // CONNECTION_CLOSED on receiving close. This state can be entered once from | |
69 // CONNECTING and unlimited number of times from RECEIVING_DATA. | |
70 // CONNECTION_CLOSED: | |
71 // The connection is closed. Refuse any further messages. Allow the reason | |
72 // for close to be retrieved. | |
73 // ERROR: | |
74 // Something bad happened along the way. Allow a reason to close be | |
75 // retrieved. The reason to close tells the receiver's user what reason to | |
76 // close the connection in case the user wants to send a CONNECTION_CLOSE. | |
77 enum State { | |
78 CONNECTING = 0x00, | |
79 WAITING = 0x01, | |
80 RECEIVING_DATA = 0x02, | |
81 DATA_READY = 0x03, | |
82 CONNECTION_CLOSED = 0x04, | |
83 ERROR_DETECTED = 0x05 | |
84 }; | |
85 | |
86 // The specific error that caused the receiver to move to ERROR state. | |
87 enum ReceiverError { | |
88 NO_ERROR_DETECTED, | |
89 EMPTY_PACKET, | |
90 RECEIVED_PACKET_IN_CONNECTION_CLOSED, | |
91 RECEIVED_DATA_IN_CONNECTING, | |
92 SERVER_RECEIVED_CONNECTION_RESPONSE, | |
93 CLIENT_RECEIVED_CONNECTION_REQUEST, | |
94 RECEIVED_CONNECTION_CLOSE_IN_CONNECTING, | |
95 UNRECOGNIZED_CONTROL_COMMAND, | |
96 INVALID_CONTROL_COMMAND_IN_DATA_TRANSACTION, | |
97 INVALID_DATA_PACKET_SIZE, | |
98 DATA_HEADER_LOW_BITS_NOT_CLEARED, | |
99 INCORRECT_DATA_FIRST_BIT, | |
100 INVALID_CONNECTION_REQUEST_SIZE, | |
101 INVALID_REQUESTED_MAX_PACKET_SIZE, | |
102 NOT_SUPPORTED_REQUESTED_VERSION, | |
103 INVALID_CONNECTION_RESPONSE_SIZE, | |
104 INVALID_SELECTED_MAX_PACKET_SIZE, | |
105 NOT_SUPPORTED_SELECTED_VERSION, | |
106 INVALID_CONNECTION_CLOSE_SIZE, | |
107 UNRECOGNIZED_REASON_FOR_CLOSE, | |
108 PACKET_OUT_OF_SEQUENCE | |
109 }; | |
110 | |
111 class Factory { | |
112 public: | |
113 static std::unique_ptr<BluetoothLowEnergyWeavePacketReceiver> NewInstance( | |
114 ReceiverType receiver_type); | |
115 | |
116 // Exposed for testing. | |
117 static void SetInstanceForTesting(std::shared_ptr<Factory> factory); | |
118 | |
119 protected: | |
120 // Exposed for testing. | |
121 virtual std::unique_ptr<BluetoothLowEnergyWeavePacketReceiver> | |
122 BuildInstance(ReceiverType receiver_type); | |
123 | |
124 private: | |
125 static std::shared_ptr<Factory> factory_instance_; | |
126 }; | |
127 | |
128 ~BluetoothLowEnergyWeavePacketReceiver(); | |
129 | |
130 typedef std::vector<uint8_t> Packet; | |
131 | |
132 // Get the receiver’s state. | |
133 virtual State GetState(); | |
134 | |
135 // Return the packet size that the receiver parsed out of request/response. | |
136 virtual uint16_t GetMaxPacketSize(); | |
137 | |
138 // Get the reason that receiver received in a connection close packet. | |
139 // It's only defined in CONNECTION_CLOSED state. | |
140 // Will crash unless receiver is in State::CONNECTION_CLOSED. | |
141 virtual ReasonForClose GetReasonForClose(); | |
142 | |
143 // The reason that the receiver decided to enter the ERROR state. | |
144 // This would be the reason that the receiver's want to send a connection | |
145 // close to the other side of the connection. | |
146 // Will crash unless receiver is in State::ERROR. | |
147 virtual ReasonForClose GetReasonToClose(); | |
148 | |
149 // Get a complete data message that's yet received. | |
150 // Will crash unless receiver is in State::DATA_READY. | |
151 // NOTE: if this function is not called in DATA_READY state and the receiver | |
152 // transitions out of that state, the data will be gone! | |
153 virtual std::string GetDataMessage(); | |
154 | |
155 // Get the specific error that caused the receiver to jump into ERROR state. | |
156 // Can be called from any state. Will return NO_ERROR if no error occurred. | |
157 virtual ReceiverError GetReceiverError(); | |
158 | |
159 // Add a packet that's just been received over Connection to the receiver. | |
160 virtual State ReceivePacket(const Packet& packet); | |
161 | |
162 protected: | |
163 explicit BluetoothLowEnergyWeavePacketReceiver(ReceiverType receiver_type); | |
164 | |
165 private: | |
166 void ReceiveFirstPacket(const Packet& packet); | |
167 void ReceiveNonFirstPacket(const Packet& packet); | |
168 | |
169 void ReceiveConnectionRequest(const Packet& packet); | |
170 void ReceiveConnectionResponse(const Packet& packet); | |
171 void ReceiveConnectionClose(const Packet& packet); | |
172 void AppendData(const Packet& packet, uint32_t byte_offset); | |
173 | |
174 uint16_t GetShortField(const Packet& packet, uint32_t byte_offset); | |
175 uint8_t GetPacketType(const Packet& packet); | |
176 uint8_t GetControlCommand(const Packet& packet); | |
177 void VerifyPacketCounter(const Packet& packet); | |
178 bool IsFirstDataPacket(const Packet& packet); | |
179 bool IsLastDataPacket(const Packet& packet); | |
180 bool AreLowerTwoBitsCleared(const Packet& packet); | |
181 | |
182 void MoveToErrorState(ReasonForClose reason_to_close, | |
183 ReceiverError receiver_error); | |
184 | |
185 void SetMaxPacketSize(uint16_t packet_size); | |
186 uint16_t GetConceptualMaxPacketSize(); | |
187 | |
188 // Identify whether the receiver is for a client or a server. | |
189 ReceiverType receiver_type_; | |
190 | |
191 // Max packet size of the connection. | |
192 // Default is 0 which means the server will determine the size by observing | |
193 // ATT_MTU of the client. | |
194 uint16_t max_packet_size_; | |
195 | |
196 // Expected counter of the next packet received, starting at 0. | |
197 uint8_t next_packet_counter_; | |
198 | |
199 // Current state of the receiver. | |
200 // Certain functions will only return valid value if the receiver is in the | |
201 // appropriate state. | |
202 State state_; | |
203 | |
204 // The reason why the connection was closed by the sender if any. | |
205 ReasonForClose reason_for_close_; | |
206 | |
207 // The reason why the receiver is in an erronous state if any. | |
208 ReasonForClose reason_to_close_; | |
209 | |
210 // The data message if there is one. | |
211 Packet data_message_; | |
212 | |
213 // The error the receiver encountered while processing packets. | |
214 // Used for debugging purproses. | |
215 ReceiverError receiver_error_; | |
216 }; | |
217 | |
218 } // namespace weave | |
219 | |
220 } // namespace proximity_auth | |
221 | |
222 #endif // COMPONENTS_PROXIMITY_AUTH_BLE_BLUETOOTH_LOW_ENERGY_WEAVE_PACKET_RECEI
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