1 /*
2  *  Copyright (c) 2016, 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:
7  *  1. Redistributions of source code must retain the above copyright
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
19  *  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
20  *  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23  *  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24  *  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25  *  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26  *  POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 /**
30  * @file
31  * @brief
32  *  This file defines the top-level OpenThread APIs related to message buffer and queues.
33  */
34 
35 #ifndef OPENTHREAD_MESSAGE_H_
36 #define OPENTHREAD_MESSAGE_H_
37 
38 #include <openthread/instance.h>
39 #include <openthread/platform/toolchain.h>
40 
41 #ifdef __cplusplus
42 extern "C" {
43 #endif
44 
45 /**
46  * @addtogroup api-message
47  *
48  * @brief
49  *   This module includes functions that manipulate OpenThread message buffers.
50  *
51  * @{
52  *
53  */
54 
55 /**
56  * An opaque representation of an OpenThread message buffer.
57  *
58  */
59 typedef struct otMessage otMessage;
60 
61 /**
62  * Defines the OpenThread message priority levels.
63  *
64  */
65 typedef enum otMessagePriority
66 {
67     OT_MESSAGE_PRIORITY_LOW    = 0, ///< Low priority level.
68     OT_MESSAGE_PRIORITY_NORMAL = 1, ///< Normal priority level.
69     OT_MESSAGE_PRIORITY_HIGH   = 2, ///< High priority level.
70 } otMessagePriority;
71 
72 /**
73  * Represents a message settings.
74  *
75  */
76 typedef struct otMessageSettings
77 {
78     bool    mLinkSecurityEnabled; ///< TRUE if the message should be secured at Layer 2.
79     uint8_t mPriority;            ///< Priority level (MUST be a `OT_MESSAGE_PRIORITY_*` from `otMessagePriority`).
80 } otMessageSettings;
81 
82 /**
83  * Free an allocated message buffer.
84  *
85  * @param[in]  aMessage  A pointer to a message buffer.
86  *
87  * @sa otMessageAppend
88  * @sa otMessageGetLength
89  * @sa otMessageSetLength
90  * @sa otMessageGetOffset
91  * @sa otMessageSetOffset
92  * @sa otMessageRead
93  * @sa otMessageWrite
94  *
95  */
96 void otMessageFree(otMessage *aMessage);
97 
98 /**
99  * Get the message length in bytes.
100  *
101  * @param[in]  aMessage  A pointer to a message buffer.
102  *
103  * @returns The message length in bytes.
104  *
105  * @sa otMessageFree
106  * @sa otMessageAppend
107  * @sa otMessageSetLength
108  * @sa otMessageGetOffset
109  * @sa otMessageSetOffset
110  * @sa otMessageRead
111  * @sa otMessageWrite
112  * @sa otMessageSetLength
113  *
114  */
115 uint16_t otMessageGetLength(const otMessage *aMessage);
116 
117 /**
118  * Set the message length in bytes.
119  *
120  * @param[in]  aMessage  A pointer to a message buffer.
121  * @param[in]  aLength   A length in bytes.
122  *
123  * @retval OT_ERROR_NONE     Successfully set the message length.
124  * @retval OT_ERROR_NO_BUFS  No available buffers to grow the message.
125  *
126  * @sa otMessageFree
127  * @sa otMessageAppend
128  * @sa otMessageGetLength
129  * @sa otMessageGetOffset
130  * @sa otMessageSetOffset
131  * @sa otMessageRead
132  * @sa otMessageWrite
133  *
134  */
135 otError otMessageSetLength(otMessage *aMessage, uint16_t aLength);
136 
137 /**
138  * Get the message offset in bytes.
139  *
140  * @param[in]  aMessage  A pointer to a message buffer.
141  *
142  * @returns The message offset value.
143  *
144  * @sa otMessageFree
145  * @sa otMessageAppend
146  * @sa otMessageGetLength
147  * @sa otMessageSetLength
148  * @sa otMessageSetOffset
149  * @sa otMessageRead
150  * @sa otMessageWrite
151  *
152  */
153 uint16_t otMessageGetOffset(const otMessage *aMessage);
154 
155 /**
156  * Set the message offset in bytes.
157  *
158  * @param[in]  aMessage  A pointer to a message buffer.
159  * @param[in]  aOffset   An offset in bytes.
160  *
161  * @sa otMessageFree
162  * @sa otMessageAppend
163  * @sa otMessageGetLength
164  * @sa otMessageSetLength
165  * @sa otMessageGetOffset
166  * @sa otMessageRead
167  * @sa otMessageWrite
168  *
169  */
170 void otMessageSetOffset(otMessage *aMessage, uint16_t aOffset);
171 
172 /**
173  * Indicates whether or not link security is enabled for the message.
174  *
175  * @param[in]  aMessage  A pointer to a message buffer.
176  *
177  * @retval TRUE   If link security is enabled.
178  * @retval FALSE  If link security is not enabled.
179  *
180  */
181 bool otMessageIsLinkSecurityEnabled(const otMessage *aMessage);
182 
183 /**
184  * Sets/forces the message to be forwarded using direct transmission.
185  * Default setting for a new message is `false`.
186  *
187  * @param[in]  aMessage  A pointer to a message buffer.
188  * @param[in]  aEnabled  If `true`, the message is forced to use direct transmission. If `false`, the message follows
189  *                       the normal procedure.
190  *
191  */
192 void otMessageSetDirectTransmission(otMessage *aMessage, bool aEnabled);
193 
194 /**
195  * Returns the average RSS (received signal strength) associated with the message.
196  *
197  * @returns The average RSS value (in dBm) or OT_RADIO_RSSI_INVALID if no average RSS is available.
198  *
199  */
200 int8_t otMessageGetRss(const otMessage *aMessage);
201 
202 /**
203  * Append bytes to a message.
204  *
205  * @param[in]  aMessage  A pointer to a message buffer.
206  * @param[in]  aBuf      A pointer to the data to append.
207  * @param[in]  aLength   Number of bytes to append.
208  *
209  * @retval OT_ERROR_NONE     Successfully appended to the message
210  * @retval OT_ERROR_NO_BUFS  No available buffers to grow the message.
211  *
212  * @sa otMessageFree
213  * @sa otMessageGetLength
214  * @sa otMessageSetLength
215  * @sa otMessageGetOffset
216  * @sa otMessageSetOffset
217  * @sa otMessageRead
218  * @sa otMessageWrite
219  *
220  */
221 otError otMessageAppend(otMessage *aMessage, const void *aBuf, uint16_t aLength);
222 
223 /**
224  * Read bytes from a message.
225  *
226  * @param[in]  aMessage  A pointer to a message buffer.
227  * @param[in]  aOffset   An offset in bytes.
228  * @param[in]  aBuf      A pointer to a buffer that message bytes are read to.
229  * @param[in]  aLength   Number of bytes to read.
230  *
231  * @returns The number of bytes read.
232  *
233  * @sa otMessageFree
234  * @sa otMessageAppend
235  * @sa otMessageGetLength
236  * @sa otMessageSetLength
237  * @sa otMessageGetOffset
238  * @sa otMessageSetOffset
239  * @sa otMessageWrite
240  *
241  */
242 uint16_t otMessageRead(const otMessage *aMessage, uint16_t aOffset, void *aBuf, uint16_t aLength);
243 
244 /**
245  * Write bytes to a message.
246  *
247  * @param[in]  aMessage  A pointer to a message buffer.
248  * @param[in]  aOffset   An offset in bytes.
249  * @param[in]  aBuf      A pointer to a buffer that message bytes are written from.
250  * @param[in]  aLength   Number of bytes to write.
251  *
252  * @returns The number of bytes written.
253  *
254  * @sa otMessageFree
255  * @sa otMessageAppend
256  * @sa otMessageGetLength
257  * @sa otMessageSetLength
258  * @sa otMessageGetOffset
259  * @sa otMessageSetOffset
260  * @sa otMessageRead
261  *
262  */
263 int otMessageWrite(otMessage *aMessage, uint16_t aOffset, const void *aBuf, uint16_t aLength);
264 
265 /**
266  * Represents an OpenThread message queue.
267  */
268 typedef struct
269 {
270     void *mData; ///< Opaque data used by the implementation.
271 } otMessageQueue;
272 
273 /**
274  * Represents information about a message queue.
275  *
276  */
277 typedef struct otMessageQueueInfo
278 {
279     uint16_t mNumMessages; ///< Number of messages in the queue.
280     uint16_t mNumBuffers;  ///< Number of data buffers used by messages in the queue.
281     uint32_t mTotalBytes;  ///< Total number of bytes used by all messages in the queue.
282 } otMessageQueueInfo;
283 
284 /**
285  * Represents the message buffer information for different queues used by OpenThread stack.
286  *
287  */
288 typedef struct otBufferInfo
289 {
290     uint16_t mTotalBuffers; ///< The total number of buffers in the messages pool (0xffff if unknown).
291     uint16_t mFreeBuffers;  ///< The number of free buffers (0xffff if unknown).
292 
293     /**
294      * The maximum number of used buffers at the same time since OT stack initialization or last call to
295      * `otMessageResetBufferInfo()`.
296      *
297      */
298     uint16_t mMaxUsedBuffers;
299 
300     otMessageQueueInfo m6loSendQueue;         ///< Info about 6LoWPAN send queue.
301     otMessageQueueInfo m6loReassemblyQueue;   ///< Info about 6LoWPAN reassembly queue.
302     otMessageQueueInfo mIp6Queue;             ///< Info about IPv6 send queue.
303     otMessageQueueInfo mMplQueue;             ///< Info about MPL send queue.
304     otMessageQueueInfo mMleQueue;             ///< Info about MLE delayed message queue.
305     otMessageQueueInfo mCoapQueue;            ///< Info about CoAP/TMF send queue.
306     otMessageQueueInfo mCoapSecureQueue;      ///< Info about CoAP secure send queue.
307     otMessageQueueInfo mApplicationCoapQueue; ///< Info about application CoAP send queue.
308 } otBufferInfo;
309 
310 /**
311  * Initialize the message queue.
312  *
313  * MUST be called once and only once for a `otMessageQueue` instance before any other `otMessageQueue`
314  * functions. The behavior is undefined if other queue APIs are used with an `otMessageQueue` before it being
315  * initialized or if it is initialized more than once.
316  *
317  * @param[in]  aQueue     A pointer to a message queue.
318  *
319  */
320 void otMessageQueueInit(otMessageQueue *aQueue);
321 
322 /**
323  * Adds a message to the end of the given message queue.
324  *
325  * @param[in]  aQueue    A pointer to the message queue.
326  * @param[in]  aMessage  The message to add.
327  *
328  */
329 void otMessageQueueEnqueue(otMessageQueue *aQueue, otMessage *aMessage);
330 
331 /**
332  * Adds a message at the head/front of the given message queue.
333  *
334  * @param[in]  aQueue    A pointer to the message queue.
335  * @param[in]  aMessage  The message to add.
336  *
337  */
338 void otMessageQueueEnqueueAtHead(otMessageQueue *aQueue, otMessage *aMessage);
339 
340 /**
341  * Removes a message from the given message queue.
342  *
343  * @param[in]  aQueue    A pointer to the message queue.
344  * @param[in]  aMessage  The message to remove.
345  *
346  */
347 void otMessageQueueDequeue(otMessageQueue *aQueue, otMessage *aMessage);
348 
349 /**
350  * Returns a pointer to the message at the head of the queue.
351  *
352  * @param[in]  aQueue    A pointer to a message queue.
353  *
354  * @returns  A pointer to the message at the head of queue or NULL if queue is empty.
355  *
356  */
357 otMessage *otMessageQueueGetHead(otMessageQueue *aQueue);
358 
359 /**
360  * Returns a pointer to the next message in the queue by iterating forward (from head to tail).
361  *
362  * @param[in]  aQueue    A pointer to a message queue.
363  * @param[in]  aMessage  A pointer to current message buffer.
364  *
365  * @returns  A pointer to the next message in the queue after `aMessage` or NULL if `aMessage is the tail of queue.
366  *           NULL is returned if `aMessage` is not in the queue `aQueue`.
367  *
368  */
369 otMessage *otMessageQueueGetNext(otMessageQueue *aQueue, const otMessage *aMessage);
370 
371 /**
372  * Get the Message Buffer information.
373  *
374  * @param[in]   aInstance    A pointer to the OpenThread instance.
375  * @param[out]  aBufferInfo  A pointer where the message buffer information is written.
376  *
377  */
378 void otMessageGetBufferInfo(otInstance *aInstance, otBufferInfo *aBufferInfo);
379 
380 /**
381  * Reset the Message Buffer information counter tracking the maximum number buffers in use at the same time.
382  *
383  * This resets `mMaxUsedBuffers` in `otBufferInfo`.
384  *
385  * @param[in]   aInstance    A pointer to the OpenThread instance.
386  *
387  */
388 void otMessageResetBufferInfo(otInstance *aInstance);
389 
390 /**
391  * @}
392  *
393  */
394 
395 #ifdef __cplusplus
396 } // extern "C"
397 #endif
398 
399 #endif // OPENTHREAD_MESSAGE_H_
400