1 /*
2  *  Copyright (c) 2018, The OpenThread Authors.
3  *  All rights reserved.
4  *
5  *  Redistribution and use in source and binary forms, with or without
6  *  modification, are permitted provided that the following conditions are met:
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8  *     notice, this list of conditions and the following disclaimer.
9  *  2. Redistributions in binary form must reproduce the above copyright
10  *     notice, this list of conditions and the following disclaimer in the
11  *     documentation and/or other materials provided with the distribution.
12  *  3. Neither the name of the copyright holder nor the
13  *     names of its contributors may be used to endorse or promote products
14  *     derived from this software without specific prior written permission.
15  *
16  *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
17  *  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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20  *  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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27  */
28 
29 /**
30  * @file
31  *   This file includes definitions for the HDLC interface to radio (RCP).
32  */
33 
34 #ifndef POSIX_APP_HDLC_INTERFACE_HPP_
35 #define POSIX_APP_HDLC_INTERFACE_HPP_
36 
37 #include "openthread-posix-config.h"
38 #include "platform-posix.h"
39 #include "lib/hdlc/hdlc.hpp"
40 #include "lib/spinel/openthread-spinel-config.h"
41 #include "lib/spinel/spinel_interface.hpp"
42 
43 #if OPENTHREAD_POSIX_CONFIG_RCP_BUS == OT_POSIX_RCP_BUS_UART
44 
45 namespace ot {
46 namespace Posix {
47 
48 /**
49  * This class defines an HDLC interface to the Radio Co-processor (RCP)
50  *
51  */
52 class HdlcInterface
53 {
54 public:
55     /**
56      * This constructor initializes the object.
57      *
58      * @param[in] aCallback         Callback on frame received
59      * @param[in] aCallbackContext  Callback context
60      * @param[in] aFrameBuffer      A reference to a `RxFrameBuffer` object.
61      *
62      */
63     HdlcInterface(Spinel::SpinelInterface::ReceiveFrameCallback aCallback,
64                   void *                                        aCallbackContext,
65                   Spinel::SpinelInterface::RxFrameBuffer &      aFrameBuffer);
66 
67     /**
68      * This destructor deinitializes the object.
69      *
70      */
71     ~HdlcInterface(void);
72 
73     /**
74      * This method initializes the interface to the Radio Co-processor (RCP)
75      *
76      * @note This method should be called before reading and sending spinel frames to the interface.
77      *
78      * @param[in]  aRadioUrl          RadioUrl parsed from radio url.
79      *
80      * @retval OT_ERROR_NONE          The interface is initialized successfully
81      * @retval OT_ERROR_ALREADY       The interface is already initialized.
82      * @retval OT_ERROR_INVALID_ARGS  The UART device or executable cannot be found or failed to open/run.
83      *
84      */
85     otError Init(const Url::Url &aRadioUrl);
86 
87     /**
88      * This method deinitializes the interface to the RCP.
89      *
90      */
91     void Deinit(void);
92 
93     /**
94      * This method encodes and sends a spinel frame to Radio Co-processor (RCP) over the socket.
95      *
96      * This is blocking call, i.e., if the socket is not writable, this method waits for it to become writable for
97      * up to `kMaxWaitTime` interval.
98      *
99      * @param[in] aFrame     A pointer to buffer containing the spinel frame to send.
100      * @param[in] aLength    The length (number of bytes) in the frame.
101      *
102      * @retval OT_ERROR_NONE     Successfully encoded and sent the spinel frame.
103      * @retval OT_ERROR_NO_BUFS  Insufficient buffer space available to encode the frame.
104      * @retval OT_ERROR_FAILED   Failed to send due to socket not becoming writable within `kMaxWaitTime`.
105      *
106      */
107     otError SendFrame(const uint8_t *aFrame, uint16_t aLength);
108 
109     /**
110      * This method waits for receiving part or all of spinel frame within specified interval.
111      *
112      * @param[in]  aTimeout  The timeout value in microseconds.
113      *
114      * @retval OT_ERROR_NONE             Part or all of spinel frame is received.
115      * @retval OT_ERROR_RESPONSE_TIMEOUT No spinel frame is received within @p aTimeout.
116      *
117      */
118     otError WaitForFrame(uint64_t aTimeoutUs);
119 
120     /**
121      * This method updates the file descriptor sets with file descriptors used by the radio driver.
122      *
123      * @param[inout]  aReadFdSet   A reference to the read file descriptors.
124      * @param[inout]  aWriteFdSet  A reference to the write file descriptors.
125      * @param[inout]  aMaxFd       A reference to the max file descriptor.
126      * @param[inout]  aTimeout     A reference to the timeout.
127      *
128      */
129     void UpdateFdSet(fd_set &aReadFdSet, fd_set &aWriteFdSet, int &aMaxFd, struct timeval &aTimeout);
130 
131     /**
132      * This method performs radio driver processing.
133      *
134      * @param[in]   aContext        The context containing fd_sets.
135      *
136      */
137     void Process(const RadioProcessContext &aContext);
138 
139 #if OPENTHREAD_POSIX_VIRTUAL_TIME
140     /**
141      * This method process read data (decode the data).
142      *
143      * This method is intended only for virtual time simulation. Its behavior is similar to `Read()` but instead of
144      * reading the data from the radio socket, it uses the given data in @p `aEvent`.
145      *
146      * @param[in] aEvent   The data event.
147      *
148      */
Process(const VirtualTimeEvent & aEvent)149     void Process(const VirtualTimeEvent &aEvent) { Decode(aEvent.mData, aEvent.mDataLength); }
150 #endif
151 
152     /**
153      * This method returns the bus speed between the host and the radio.
154      *
155      * @returns   Bus speed in bits/second.
156      *
157      */
GetBusSpeed(void) const158     uint32_t GetBusSpeed(void) const { return mBaudRate; }
159 
160     /**
161      * This method is called when RCP failure detected and resets internal states of the interface.
162      *
163      */
164     void OnRcpReset(void);
165 
166 #if OPENTHREAD_SPINEL_CONFIG_RESET_CONNECTION
167     /**
168      * This method is called when RCP is reset to recreate the connection with it.
169      *
170      */
171     otError ResetConnection(void);
172 #endif
173 
174 private:
175     /**
176      * This method instructs `HdlcInterface` to read and decode data from radio over the socket.
177      *
178      * If a full HDLC frame is decoded while reading data, this method invokes the `HandleReceivedFrame()` (on the
179      * `aCallback` object from constructor) to pass the received frame to be processed.
180      *
181      */
182     void Read(void);
183 
184     /**
185      * This method waits for the socket file descriptor associated with the HDLC interface to become writable within
186      * `kMaxWaitTime` interval.
187      *
188      * @retval OT_ERROR_NONE   Socket is writable.
189      * @retval OT_ERROR_FAILED Socket did not become writable within `kMaxWaitTime`.
190      *
191      */
192     otError WaitForWritable(void);
193 
194     /**
195      * This method writes a given frame to the socket.
196      *
197      * This is blocking call, i.e., if the socket is not writable, this method waits for it to become writable for
198      * up to `kMaxWaitTime` interval.
199      *
200      * @param[in] aFrame  A pointer to buffer containing the frame to write.
201      * @param[in] aLength The length (number of bytes) in the frame.
202      *
203      * @retval OT_ERROR_NONE    Frame was written successfully.
204      * @retval OT_ERROR_FAILED  Failed to write due to socket not becoming writable within `kMaxWaitTime`.
205      *
206      */
207     otError Write(const uint8_t *aFrame, uint16_t aLength);
208 
209     /**
210      * This method performs HDLC decoding on received data.
211      *
212      * If a full HDLC frame is decoded while reading data, this method invokes the `HandleReceivedFrame()` (on the
213      * `aCallback` object from constructor) to pass the received frame to be processed.
214      *
215      * @param[in] aBuffer  A pointer to buffer containing data.
216      * @param[in] aLength  The length (number of bytes) in the buffer.
217      *
218      */
219     void Decode(const uint8_t *aBuffer, uint16_t aLength);
220 
221     static void HandleHdlcFrame(void *aContext, otError aError);
222     void        HandleHdlcFrame(otError aError);
223 
224     /**
225      * This method opens file specified by aRadioUrl.
226      *
227      * @param[in] aRadioUrl  A reference to object containing path to file and data for configuring
228      *                       the connection with tty type file.
229      *
230      * @retval The file descriptor of newly opened file.
231      */
232     int OpenFile(const Url::Url &aRadioUrl);
233 
234     /**
235      * This method closes file associated with the file descriptor.
236      *
237      */
238     void CloseFile(void);
239 
240 #if OPENTHREAD_SPINEL_CONFIG_RESET_CONNECTION
241     /**
242      * This method waits until enumeration of RCP(USB CDC ACM) device ends.
243      *
244      * This is blocking call, this method waits for up to 10 seconds.
245      *
246      * @param[in] aRadioUrlPath  A path to RCP device.
247      *
248      * @retval OT_ERROR_NONE    The RCP device has been added to the host OS before timeout ends.
249      * @retval OT_ERROR_FAILED  The RCP device has not been added to the host OS before timeout ends.
250      *
251      */
252     otError WaitForUsbDevice(const char *aRadioUrlPath);
253 #endif
254 
255 #if OPENTHREAD_POSIX_CONFIG_RCP_PTY_ENABLE
256     static int ForkPty(const Url::Url &aRadioUrl);
257 #endif
258 
259     enum
260     {
261         kMaxFrameSize = Spinel::SpinelInterface::kMaxFrameSize,
262         kMaxWaitTime  = 2000, ///< Maximum wait time in Milliseconds for socket to become writable (see `SendFrame`).
263     };
264 
265     Spinel::SpinelInterface::ReceiveFrameCallback mReceiveFrameCallback;
266     void *                                        mReceiveFrameContext;
267     Spinel::SpinelInterface::RxFrameBuffer &      mReceiveFrameBuffer;
268 
269     int             mSockFd;
270     uint32_t        mBaudRate;
271     Hdlc::Decoder   mHdlcDecoder;
272     const Url::Url *mRadioUrl;
273 
274     // Non-copyable, intentionally not implemented.
275     HdlcInterface(const HdlcInterface &);
276     HdlcInterface &operator=(const HdlcInterface &);
277 };
278 
279 } // namespace Posix
280 } // namespace ot
281 
282 #endif // OPENTHREAD_POSIX_CONFIG_RCP_BUS == OT_POSIX_RCP_BUS_UART
283 #endif // POSIX_APP_HDLC_INTERFACE_HPP_
284