xref: /btstack/src/ble/gatt_client.h (revision a94d23eaebfede58bf9fb58975795b387dd511df)
1 /*
2  * Copyright (C) 2014 BlueKitchen GmbH
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the copyright holders nor the names of
14  *    contributors may be used to endorse or promote products derived
15  *    from this software without specific prior written permission.
16  * 4. Any redistribution, use, or modification is done solely for
17  *    personal benefit and not for any commercial purpose or for
18  *    monetary gain.
19  *
20  * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL BLUEKITCHEN
24  * GMBH OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
27  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
30  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * Please inquire about commercial licensing options at
34  * [email protected]
35  *
36  */
37 
38 /**
39  * @title GATT Client
40  *
41  */
42 
43 #ifndef btstack_gatt_client_h
44 #define btstack_gatt_client_h
45 
46 #include "hci.h"
47 
48 // spec defines 100 ms, PTS might indicate an error if we sent after 100 ms
49 #define GATT_CLIENT_COLLISION_BACKOFF_MS 150
50 #if defined __cplusplus
51 extern "C" {
52 #endif
53 
54 typedef enum {
55     P_READY,
56     P_W2_EMIT_QUERY_COMPLETE_EVENT,
57     P_W2_SEND_SERVICE_QUERY,
58     P_W4_SERVICE_QUERY_RESULT,
59     P_W2_SEND_SERVICE_WITH_UUID_QUERY,
60     P_W4_SERVICE_WITH_UUID_RESULT,
61 
62     P_W2_SEND_ALL_CHARACTERISTICS_OF_SERVICE_QUERY,
63     P_W4_ALL_CHARACTERISTICS_OF_SERVICE_QUERY_RESULT,
64     P_W2_SEND_CHARACTERISTIC_WITH_UUID_QUERY,
65     P_W4_CHARACTERISTIC_WITH_UUID_QUERY_RESULT,
66 
67     P_W2_SEND_ALL_CHARACTERISTIC_DESCRIPTORS_QUERY,
68     P_W4_ALL_CHARACTERISTIC_DESCRIPTORS_QUERY_RESULT,
69 
70     P_W2_SEND_INCLUDED_SERVICE_QUERY,
71     P_W4_INCLUDED_SERVICE_QUERY_RESULT,
72     P_W2_SEND_INCLUDED_SERVICE_WITH_UUID_QUERY,
73     P_W4_INCLUDED_SERVICE_UUID_WITH_QUERY_RESULT,
74 
75     P_W2_SEND_READ_CHARACTERISTIC_VALUE_QUERY,
76     P_W4_READ_CHARACTERISTIC_VALUE_RESULT,
77 
78     P_W2_SEND_READ_BLOB_QUERY,
79     P_W4_READ_BLOB_RESULT,
80 
81     P_W2_SEND_READ_BY_TYPE_REQUEST,
82     P_W4_READ_BY_TYPE_RESPONSE,
83 
84     P_W2_SEND_READ_MULTIPLE_REQUEST,
85     P_W4_READ_MULTIPLE_RESPONSE,
86 
87     P_W2_SEND_READ_MULTIPLE_VARIABLE_REQUEST,
88     P_W4_READ_MULTIPLE_VARIABLE_RESPONSE,
89 
90     P_W2_SEND_WRITE_CHARACTERISTIC_VALUE,
91     P_W4_WRITE_CHARACTERISTIC_VALUE_RESULT,
92 
93     P_W2_PREPARE_WRITE,
94     P_W4_PREPARE_WRITE_RESULT,
95     P_W2_PREPARE_RELIABLE_WRITE,
96     P_W4_PREPARE_RELIABLE_WRITE_RESULT,
97 
98     P_W2_EXECUTE_PREPARED_WRITE,
99     P_W4_EXECUTE_PREPARED_WRITE_RESULT,
100     P_W2_CANCEL_PREPARED_WRITE,
101     P_W4_CANCEL_PREPARED_WRITE_RESULT,
102     P_W2_CANCEL_PREPARED_WRITE_DATA_MISMATCH,
103     P_W4_CANCEL_PREPARED_WRITE_DATA_MISMATCH_RESULT,
104 
105 #ifdef ENABLE_GATT_FIND_INFORMATION_FOR_CCC_DISCOVERY
106     P_W2_SEND_FIND_CLIENT_CHARACTERISTIC_CONFIGURATION_QUERY,
107     P_W4_FIND_CLIENT_CHARACTERISTIC_CONFIGURATION_QUERY_RESULT,
108 #else
109     P_W2_SEND_READ_CLIENT_CHARACTERISTIC_CONFIGURATION_QUERY,
110     P_W4_READ_CLIENT_CHARACTERISTIC_CONFIGURATION_QUERY_RESULT,
111 #endif
112     P_W2_WRITE_CLIENT_CHARACTERISTIC_CONFIGURATION,
113     P_W4_CLIENT_CHARACTERISTIC_CONFIGURATION_RESULT,
114 
115     P_W2_SEND_READ_CHARACTERISTIC_DESCRIPTOR_QUERY,
116     P_W4_READ_CHARACTERISTIC_DESCRIPTOR_RESULT,
117 
118     P_W2_SEND_READ_BLOB_CHARACTERISTIC_DESCRIPTOR_QUERY,
119     P_W4_READ_BLOB_CHARACTERISTIC_DESCRIPTOR_RESULT,
120 
121     P_W2_SEND_WRITE_CHARACTERISTIC_DESCRIPTOR,
122     P_W4_WRITE_CHARACTERISTIC_DESCRIPTOR_RESULT,
123 
124     // all long writes use this
125     P_W2_PREPARE_WRITE_CHARACTERISTIC_DESCRIPTOR,
126     P_W4_PREPARE_WRITE_CHARACTERISTIC_DESCRIPTOR_RESULT,
127     P_W2_EXECUTE_PREPARED_WRITE_CHARACTERISTIC_DESCRIPTOR,
128     P_W4_EXECUTE_PREPARED_WRITE_CHARACTERISTIC_DESCRIPTOR_RESULT,
129 
130     // gatt reliable write API use this (manual version of the above)
131     P_W2_PREPARE_WRITE_SINGLE,
132     P_W4_PREPARE_WRITE_SINGLE_RESULT,
133 
134     P_W4_IDENTITY_RESOLVING,
135     P_W4_CMAC_READY,
136     P_W4_CMAC_RESULT,
137     P_W2_SEND_SIGNED_WRITE,
138     P_W4_SEND_SIGNED_WRITE_DONE,
139 
140     P_W2_SDP_QUERY,
141     P_W4_SDP_QUERY,
142     P_W2_L2CAP_CONNECT,
143     P_W4_L2CAP_CONNECTION,
144     P_W2_EMIT_CONNECTED,
145     P_L2CAP_CLOSED,
146 } gatt_client_state_t;
147 
148 
149 typedef enum{
150     SEND_MTU_EXCHANGE,
151     SENT_MTU_EXCHANGE,
152     MTU_EXCHANGED,
153     MTU_AUTO_EXCHANGE_DISABLED
154 } gatt_client_mtu_t;
155 
156 typedef enum {
157     GATT_CLIENT_SERVICE_DISCOVER_W2_SEND,
158     GATT_CLIENT_SERVICE_DISCOVER_W4_DONE,
159     GATT_CLIENT_SERVICE_DISCOVER_CHARACTERISTICS_W2_SEND,
160     GATT_CLIENT_SERVICE_DISCOVER_CHARACTERISTICS_W4_DONE,
161     GATT_CLIENT_SERVICE_SERVICE_CHANGED_WRITE_CCCD_W2_SEND,
162     GATT_CLIENT_SERVICE_SERVICE_CHANGED_WRITE_CCCD_W4_DONE,
163     GATT_CLIENT_SERVICE_DATABASE_HASH_READ_W2_SEND,
164     GATT_CLIENT_SERVICE_DATABASE_HASH_READ_W4_DONE,
165     GATT_CLIENT_SERVICE_DATABASE_HASH_WRITE_CCCD_W2_SEND,
166     GATT_CLIENT_SERVICE_DATABASE_HASH_WRITE_CCCD_W4_DONE,
167     GATT_CLIENT_SERVICE_DONE,
168 } gatt_client_service_state_t;
169 
170 #ifdef ENABLE_GATT_OVER_EATT
171 typedef enum {
172     GATT_CLIENT_EATT_IDLE,
173     GATT_CLIENT_EATT_DISCOVER_GATT_SERVICE_W2_SEND,
174     GATT_CLIENT_EATT_DISCOVER_GATT_SERVICE_W4_DONE,
175     GATT_CLIENT_EATT_READ_SERVER_SUPPORTED_FEATURES_W2_SEND,
176     GATT_CLIENT_EATT_READ_SERVER_SUPPORTED_FEATURES_W4_DONE,
177     GATT_CLIENT_EATT_FIND_CLIENT_SUPPORTED_FEATURES_W2_SEND,
178     GATT_CLIENT_EATT_FIND_CLIENT_SUPPORTED_FEATURES_W4_DONE,
179     GATT_CLIENT_EATT_WRITE_ClIENT_SUPPORTED_FEATURES_W2_SEND,
180     GATT_CLIENT_EATT_WRITE_ClIENT_SUPPORTED_FEATURES_W4_DONE,
181     GATT_CLIENT_EATT_L2CAP_SETUP,
182     GATT_CLIENT_EATT_READY,
183 } gatt_client_eatt_state_t;
184 #endif
185 
186 typedef struct gatt_client{
187     btstack_linked_item_t    item;
188 
189     gatt_client_state_t state;
190 
191     // user callback
192     btstack_packet_handler_t callback;
193 
194     // can write without response callback
195     btstack_packet_handler_t write_without_response_callback;
196 
197     // can write without response requests
198     btstack_linked_list_t write_without_response_requests;
199 
200     // regular gatt query requests
201     btstack_linked_list_t query_requests;
202 
203     hci_con_handle_t con_handle;
204 
205     att_bearer_type_t bearer_type;
206 
207 #if defined(ENABLE_GATT_OVER_CLASSIC) || defined(ENABLE_GATT_OVER_EATT)
208     uint16_t  l2cap_cid;
209     bd_addr_t addr;
210     bd_addr_type_t  addr_type;
211 #endif
212 
213 #ifdef ENABLE_GATT_OVER_CLASSIC
214     uint16_t  l2cap_psm;
215     btstack_context_callback_registration_t callback_request;
216 #endif
217 
218 #ifdef ENABLE_GATT_OVER_EATT
219     gatt_client_eatt_state_t eatt_state;
220     btstack_linked_list_t eatt_clients;
221     uint8_t * eatt_storage_buffer;
222     uint16_t eatt_storage_size;
223     uint8_t  eatt_num_clients;
224     uint8_t  gatt_server_supported_features;
225     uint16_t gatt_client_supported_features_handle;
226 #endif
227 
228     uint16_t          mtu;
229     gatt_client_mtu_t mtu_state;
230 
231     uint16_t uuid16;
232     uint8_t  uuid128[16];
233 
234     uint16_t start_group_handle;
235     uint16_t end_group_handle;
236 
237     uint16_t query_start_handle;
238     uint16_t query_end_handle;
239 
240     uint8_t  characteristic_properties;
241     uint16_t characteristic_start_handle;
242 
243     uint16_t attribute_handle;
244     uint16_t attribute_offset;
245     uint16_t attribute_length;
246     uint8_t* attribute_value;
247 
248     // read multiple characteristic values
249     uint16_t    read_multiple_handle_count;
250     uint16_t  * read_multiple_handles;
251 
252     uint16_t client_characteristic_configuration_handle;
253     uint8_t  client_characteristic_configuration_value[2];
254 
255     bool     filter_with_uuid;
256     bool     send_confirmation;
257 
258     int      le_device_index;
259     uint8_t  cmac[8];
260 
261     btstack_timer_source_t gc_timeout;
262 
263     uint8_t  security_counter;
264     bool     wait_for_authentication_complete;
265     uint8_t  pending_error_code;
266 
267     bool     reencryption_active;
268     uint8_t  reencryption_result;
269 
270     gap_security_level_t security_level;
271 
272     // Context
273     uint16_t service_id;
274     uint16_t connection_id;
275 
276     // GATT Service Changes
277     gatt_client_service_state_t gatt_service_state;
278     uint16_t                    gatt_service_start_group_handle;
279     uint16_t                    gatt_service_end_group_handle;
280     // - Service Changed
281     uint16_t                    gatt_service_changed_value_handle;
282     uint16_t                    gatt_service_changed_cccd_handle;
283     uint16_t                    gatt_service_changed_end_handle;
284     // - Database Hash
285     uint16_t                    gatt_service_database_hash_value_handle;
286     uint16_t                    gatt_service_database_hash_cccd_handle;
287     uint16_t                    gatt_service_database_hash_end_handle;
288 
289 } gatt_client_t;
290 
291 typedef struct gatt_client_notification {
292     btstack_linked_item_t    item;
293     btstack_packet_handler_t callback;
294     hci_con_handle_t con_handle;
295     uint16_t attribute_handle;
296 } gatt_client_notification_t;
297 
298 /* API_START */
299 
300 typedef struct {
301     uint16_t start_group_handle;
302     uint16_t end_group_handle;
303     uint16_t uuid16;
304     uint8_t  uuid128[16];
305 } gatt_client_service_t;
306 
307 typedef struct {
308     uint16_t start_handle;
309     uint16_t value_handle;
310     uint16_t end_handle;
311     uint16_t properties;
312     uint16_t uuid16;
313     uint8_t  uuid128[16];
314 } gatt_client_characteristic_t;
315 
316 typedef struct {
317     uint16_t handle;
318     uint16_t uuid16;
319     uint8_t  uuid128[16];
320 } gatt_client_characteristic_descriptor_t;
321 
322 /**
323  * @brief Set up GATT client.
324  */
325 void gatt_client_init(void);
326 
327 /**
328  * @brief Set minimum required security level for GATT Client
329  * @note  The Bluetooth specification makes the GATT Server responsible to check for security.
330  *        This allows an attacker to spoof an existing device with a GATT Servers, but skip the authentication part.
331  *        If your application is exchanging sensitive data with a remote device, you would need to manually check
332  *        the security level before sending/receive such data.
333  *        With level > 0, the GATT Client triggers authentication for all GATT Requests and defers any exchange
334  *        until the required security level is established.
335  *        gatt_client_request_can_write_without_response_event does not trigger authentication
336  *        gatt_client_request_to_write_without_response does not trigger authentication
337  *  @pram level, default LEVEL_0 (no encryption required)
338  */
339 void gatt_client_set_required_security_level(gap_security_level_t level);
340 
341 /**
342  * @brief Connect to remote GATT Server over Classic (BR/EDR) Connection
343  *        GATT_EVENT_CONNECTED with status and con_handle for other API functions
344  *        is emitted on connection complete.
345  * @note requires ENABLE_GATT_OVER_CLASSIC.
346  * @param addr
347  * @return status
348  */
349 uint8_t gatt_client_classic_connect(btstack_packet_handler_t callback, bd_addr_t addr);
350 
351 /**
352  * @brief Disconnect o Classic (BR/EDR) connection to a remote GATT Server
353  * @note requires ENABLE_GATT_OVER_CLASSIC
354  * @param con_handle
355  * @return status
356  */
357 uint8_t gatt_client_classic_disconnect(btstack_packet_handler_t callback, hci_con_handle_t con_handle);
358 
359 /**
360  * @brief Setup Enhanced LE Bearer with up to 5 channels on existing LE connection
361  * @param callback for GATT_EVENT_CONNECTED and GATT_EVENT_DISCONNECTED events
362  * @param con_handle
363  * @param num_channels
364  * @param storage_buffer for L2CAP connection
365  * @param storage_size - each channel requires (2 * ATT MTU) + 10 bytes
366  * @return
367  */
368 uint8_t gatt_client_le_enhanced_connect(btstack_packet_handler_t callback, hci_con_handle_t con_handle, uint8_t num_channels, uint8_t * storage_buffer, uint16_t storage_size);
369 
370 /**
371  * @brief MTU is available after the first query has completed. If status is equal to ERROR_CODE_SUCCESS, it returns the real value,
372  * otherwise the default value ATT_DEFAULT_MTU (see bluetooth.h).
373  * @param  con_handle
374  * @param  mtu
375  * @return status ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER                  if no HCI connection for con_handle is found
376  *                BTSTACK_MEMORY_ALLOC_FAILED                               if no GATT client for con_handle could be allocated
377  *                GATT_CLIENT_IN_WRONG_STATE                                if MTU is not exchanged and MTU auto-exchange is disabled
378  *                ERROR_CODE_SUCCESS                                        if query is successfully registered
379  */
380 uint8_t gatt_client_get_mtu(hci_con_handle_t con_handle, uint16_t * mtu);
381 
382 /**
383  * @brief Sets whether a MTU Exchange Request shall be automatically send before the
384  * first attribute read request is send. Default is enabled.
385  * @param enabled
386  */
387 void gatt_client_mtu_enable_auto_negotiation(uint8_t enabled);
388 
389 /**
390  * @brief Sends a MTU Exchange Request, this allows for the client to exchange MTU
391  * when gatt_client_mtu_enable_auto_negotiation is disabled.
392  * @param  callback
393  * @param  con_handle
394  */
395 void gatt_client_send_mtu_negotiation(btstack_packet_handler_t callback, hci_con_handle_t con_handle);
396 
397 /**
398  * @brief Returns 1 if the GATT client is ready to receive a query. It is used with daemon.
399  * @param  con_handle
400  * @return is_ready_status     0 - if no GATT client for con_handle is found, or is not ready, otherwise 1
401  */
402 int gatt_client_is_ready(hci_con_handle_t con_handle);
403 
404 /**
405  * @brief Discovers all primary services.
406  * For each found service a GATT_EVENT_SERVICE_QUERY_RESULT event will be emitted.
407  * The GATT_EVENT_QUERY_COMPLETE event marks the end of discovery.
408  * @param  callback
409  * @param  con_handle
410  * @return status BTSTACK_MEMORY_ALLOC_FAILED, if no GATT client for con_handle is found
411  *                GATT_CLIENT_IN_WRONG_STATE , if GATT client is not ready
412  *                ERROR_CODE_SUCCESS         , if query is successfully registered
413  */
414 uint8_t gatt_client_discover_primary_services(btstack_packet_handler_t callback, hci_con_handle_t con_handle);
415 
416 /**
417  * @brief Discovers all secondary services.
418  * For each found service a GATT_EVENT_SERVICE_QUERY_RESULT event will be emitted.
419  * The GATT_EVENT_QUERY_COMPLETE event marks the end of discovery.
420  * @param  callback
421  * @param  con_handle
422  * @return status BTSTACK_MEMORY_ALLOC_FAILED, if no GATT client for con_handle is found
423  *                GATT_CLIENT_IN_WRONG_STATE , if GATT client is not ready
424  *                ERROR_CODE_SUCCESS         , if query is successfully registered
425  */
426 uint8_t gatt_client_discover_secondary_services(btstack_packet_handler_t callback, hci_con_handle_t con_handle);
427 
428 /**
429  * @brief Discovers a specific primary service given its UUID. This service may exist multiple times.
430  * For each found service a GATT_EVENT_SERVICE_QUERY_RESULT event will be emitted.
431  * The GATT_EVENT_QUERY_COMPLETE event marks the end of discovery.
432  * @param callback
433  * @param con_handle
434  * @param uuid16
435  * @return status BTSTACK_MEMORY_ALLOC_FAILED, if no GATT client for con_handle is found
436  *                GATT_CLIENT_IN_WRONG_STATE , if GATT client is not ready
437  *                ERROR_CODE_SUCCESS         , if query is successfully registered
438  */
439 uint8_t gatt_client_discover_primary_services_by_uuid16(btstack_packet_handler_t callback, hci_con_handle_t con_handle, uint16_t uuid16);
440 
441 /**
442  * @brief Discovers a specific primary service given its UUID. This service may exist multiple times.
443  * For each found service a GATT_EVENT_SERVICE_QUERY_RESULT event will be emitted.
444  * The GATT_EVENT_QUERY_COMPLETE event marks the end of discovery.
445  * @param callback
446  * @param con_handle
447  * @param uuid16
448  * @param service_id    - context provided to callback in events
449  * @param connection_id - contest provided to callback in events
450  * @return status BTSTACK_MEMORY_ALLOC_FAILED, if no GATT client for con_handle is found
451  *                GATT_CLIENT_IN_WRONG_STATE , if GATT client is not ready
452  *                ERROR_CODE_SUCCESS         , if query is successfully registered
453  */
454 uint8_t gatt_client_discover_primary_services_by_uuid16_with_context(btstack_packet_handler_t callback, hci_con_handle_t con_handle,
455                                                                      uint16_t uuid16, uint16_t service_id, uint16_t connection_id);
456 
457 /**
458  * @brief Discovers a specific primary service given its UUID. This service may exist multiple times.
459  * For each found service a GATT_EVENT_SERVICE_QUERY_RESULT event will be emitted.
460  * The GATT_EVENT_QUERY_COMPLETE event marks the end of discovery.
461  * @param  callback
462  * @param  con_handle
463  * @param  uuid128
464  * @return status BTSTACK_MEMORY_ALLOC_FAILED, if no GATT client for con_handle is found
465  *                GATT_CLIENT_IN_WRONG_STATE , if GATT client is not ready
466  *                ERROR_CODE_SUCCESS         , if query is successfully registered
467  */
468 uint8_t gatt_client_discover_primary_services_by_uuid128(btstack_packet_handler_t callback, hci_con_handle_t con_handle, const uint8_t * uuid128);
469 
470 /**
471  * @brief Finds included services within the specified service.
472  * For each found included service a GATT_EVENT_INCLUDED_SERVICE_QUERY_RESULT event will be emitted.
473  * The GATT_EVENT_QUERY_COMPLETE event marks the end of discovery.
474  * Information about included service type (primary/secondary) can be retrieved either by sending
475  * an ATT find information request for the returned start group handle
476  * (returning the handle and the UUID for primary or secondary service) or by comparing the service
477  * to the list of all primary services.
478  * @param  callback
479  * @param  con_handle
480  * @param  service
481  * @return status BTSTACK_MEMORY_ALLOC_FAILED, if no GATT client for con_handle is found
482  *                GATT_CLIENT_IN_WRONG_STATE , if GATT client is not ready
483  *                ERROR_CODE_SUCCESS         , if query is successfully registered
484  */
485 uint8_t gatt_client_find_included_services_for_service(btstack_packet_handler_t callback, hci_con_handle_t con_handle, gatt_client_service_t * service);
486 
487 /**
488  * @brief Finds included services within the specified service.
489  * For each found included service a GATT_EVENT_INCLUDED_SERVICE_QUERY_RESULT event will be emitted.
490  * The GATT_EVENT_QUERY_COMPLETE event marks the end of discovery.
491  * Information about included service type (primary/secondary) can be retrieved either by sending
492  * an ATT find information request for the returned start group handle
493  * (returning the handle and the UUID for primary or secondary service) or by comparing the service
494  * to the list of all primary services.
495  * @param  callback
496  * @param  con_handle
497  * @param  service_id    - context provided to callback in events
498  * @param  connection_id - contest provided to callback in events
499  * @param  service_id
500  * @return status BTSTACK_MEMORY_ALLOC_FAILED, if no GATT client for con_handle is found
501  *                GATT_CLIENT_IN_WRONG_STATE , if GATT client is not ready
502  *                ERROR_CODE_SUCCESS         , if query is successfully registered
503  */
504 uint8_t gatt_client_find_included_services_for_service_with_context(btstack_packet_handler_t callback, hci_con_handle_t con_handle,
505                                                                     gatt_client_service_t * service, uint16_t service_id, uint16_t connection_id);
506 
507 /**
508  * @brief Discovers all characteristics within the specified service.
509  * For each found characteristic a GATT_EVENT_CHARACTERISTIC_QUERY_RESULT event will be emited.
510  * The GATT_EVENT_QUERY_COMPLETE event marks the end of discovery.
511  * @param  callback
512  * @param  con_handle
513  * @param  service
514  * @return status BTSTACK_MEMORY_ALLOC_FAILED, if no GATT client for con_handle is found
515  *                GATT_CLIENT_IN_WRONG_STATE , if GATT client is not ready
516  *                ERROR_CODE_SUCCESS         , if query is successfully registered
517  */
518 uint8_t gatt_client_discover_characteristics_for_service(btstack_packet_handler_t callback, hci_con_handle_t con_handle, gatt_client_service_t * service);
519 
520 /**
521  * @brief Discovers all characteristics within the specified service.
522  * For each found characteristic a GATT_EVENT_CHARACTERISTIC_QUERY_RESULT event will be emited.
523  * The GATT_EVENT_QUERY_COMPLETE event marks the end of discovery.
524  * @param  callback
525  * @param  con_handle
526  * @param  service
527  * @param  service_id    - context provided to callback in events
528  * @param  connection_id - contest provided to callback in events
529  * @return status BTSTACK_MEMORY_ALLOC_FAILED, if no GATT client for con_handle is found
530  *                GATT_CLIENT_IN_WRONG_STATE , if GATT client is not ready
531  *                ERROR_CODE_SUCCESS         , if query is successfully registered
532  */
533 uint8_t gatt_client_discover_characteristics_for_service_with_context(btstack_packet_handler_t callback, hci_con_handle_t con_handle, gatt_client_service_t * service,
534                                                                       uint16_t service_id, uint16_t connection_id);
535 
536 /**
537  * @brief The following four functions are used to discover all characteristics within
538  * the specified service or handle range, and return those that match the given UUID.
539  *
540  * For each found characteristic a GATT_EVENT_CHARACTERISTIC_QUERY_RESULT event will emitted.
541  * The GATT_EVENT_QUERY_COMPLETE event marks the end of discovery.
542  * @param  callback
543  * @param  con_handle
544  * @param  start_handle
545  * @param  end_handle
546  * @param  uuid16
547  * @return status BTSTACK_MEMORY_ALLOC_FAILED, if no GATT client for con_handle is found
548  *                GATT_CLIENT_IN_WRONG_STATE , if GATT client is not ready
549  *                ERROR_CODE_SUCCESS         , if query is successfully registered
550  */
551 uint8_t gatt_client_discover_characteristics_for_handle_range_by_uuid16(btstack_packet_handler_t callback, hci_con_handle_t con_handle, uint16_t start_handle, uint16_t end_handle, uint16_t uuid16);
552 
553 /**
554  * @brief The following four functions are used to discover all characteristics within the
555  * specified service or handle range, and return those that match the given UUID.
556  * For each found characteristic a GATT_EVENT_CHARACTERISTIC_QUERY_RESULT event will emitted.
557  * The GATT_EVENT_QUERY_COMPLETE event marks the end of discovery.
558  * @param  callback
559  * @param  con_handle
560  * @param  start_handle
561  * @param  end_handle
562  * @param  uuid128
563  * @return status BTSTACK_MEMORY_ALLOC_FAILED, if no GATT client for con_handle is found
564  *                GATT_CLIENT_IN_WRONG_STATE , if GATT client is not ready
565  *                ERROR_CODE_SUCCESS         , if query is successfully registered
566  */
567 uint8_t gatt_client_discover_characteristics_for_handle_range_by_uuid128(btstack_packet_handler_t callback, hci_con_handle_t con_handle, uint16_t start_handle, uint16_t end_handle, const uint8_t * uuid128);
568 
569 /**
570  * @brief The following four functions are used to discover all characteristics within the
571  * specified service or handle range, and return those that match the given UUID.
572  * For each found characteristic a GATT_EVENT_CHARACTERISTIC_QUERY_RESULT event will emitted.
573  * The GATT_EVENT_QUERY_COMPLETE event marks the end of discovery.
574  * @param  callback
575  * @param  con_handle
576  * @param  service
577  * @param  uuid16
578  * @return status BTSTACK_MEMORY_ALLOC_FAILED, if no GATT client for con_handle is found
579  *                GATT_CLIENT_IN_WRONG_STATE , if GATT client is not ready
580  *                ERROR_CODE_SUCCESS         , if query is successfully registered
581  */
582 uint8_t gatt_client_discover_characteristics_for_service_by_uuid16(btstack_packet_handler_t callback, hci_con_handle_t con_handle, gatt_client_service_t * service, uint16_t uuid16);
583 
584 /**
585  * @brief The following four functions are used to discover all characteristics within the
586  * specified service or handle range, and return those that match the given UUID.
587  * For each found characteristic a GATT_EVENT_CHARACTERISTIC_QUERY_RESULT event will emitted.
588  * The GATT_EVENT_QUERY_COMPLETE event marks the end of discovery.
589  * @param  callback
590  * @param  con_handle
591  * @param  service
592  * @param  uuid128
593  * @return status BTSTACK_MEMORY_ALLOC_FAILED, if no GATT client for con_handle is found
594  *                GATT_CLIENT_IN_WRONG_STATE , if GATT client is not ready
595  *                ERROR_CODE_SUCCESS         , if query is successfully registered
596  */
597 uint8_t gatt_client_discover_characteristics_for_service_by_uuid128(btstack_packet_handler_t callback, hci_con_handle_t con_handle, gatt_client_service_t * service, const uint8_t * uuid128);
598 
599 /**
600  * @brief Discovers attribute handle and UUID of a characteristic descriptor within the specified characteristic.
601  * For each found descriptor a GATT_EVENT_ALL_CHARACTERISTIC_DESCRIPTORS_QUERY_RESULT event will be emitted.
602  *
603  * The GATT_EVENT_QUERY_COMPLETE event marks the end of discovery.
604  * @param  callback
605  * @param  con_handle
606  * @param  characteristic
607  * @return status BTSTACK_MEMORY_ALLOC_FAILED, if no GATT client for con_handle is found
608  *                GATT_CLIENT_IN_WRONG_STATE , if GATT client is not ready
609  *                ERROR_CODE_SUCCESS         , if query is successfully registered
610  */
611 uint8_t gatt_client_discover_characteristic_descriptors(btstack_packet_handler_t callback, hci_con_handle_t con_handle, gatt_client_characteristic_t * characteristic);
612 
613 
614 /**
615  * @brief Discovers attribute handle and UUID of a characteristic descriptor within the specified characteristic.
616  * For each found descriptor a GATT_EVENT_ALL_CHARACTERISTIC_DESCRIPTORS_QUERY_RESULT event will be emitted.
617  *
618  * The GATT_EVENT_QUERY_COMPLETE event marks the end of discovery.
619  * @param  callback
620  * @param  con_handle
621  * @param  characteristic
622  * @param  service_id    - context provided to callback in events
623  * @param  connection_id - contest provided to callback in events
624  * @return status BTSTACK_MEMORY_ALLOC_FAILED, if no GATT client for con_handle is found
625  *                GATT_CLIENT_IN_WRONG_STATE , if GATT client is not ready
626  *                ERROR_CODE_SUCCESS         , if query is successfully registered
627  */
628 uint8_t gatt_client_discover_characteristic_descriptors_with_context(btstack_packet_handler_t callback, hci_con_handle_t con_handle,
629                                                                      gatt_client_characteristic_t * characteristic, uint16_t service_id, uint16_t connection_it);
630 
631 /**
632  * @brief Reads the characteristic value using the characteristic's value handle.
633  * If the characteristic value is found a GATT_EVENT_CHARACTERISTIC_VALUE_QUERY_RESULT event will be emitted.
634  * The GATT_EVENT_QUERY_COMPLETE event marks the end of read.
635  * @param  callback
636  * @param  con_handle
637  * @param  characteristic
638  * @return status BTSTACK_MEMORY_ALLOC_FAILED, if no GATT client for con_handle is found
639  *                GATT_CLIENT_IN_WRONG_STATE , if GATT client is not ready
640  *                ERROR_CODE_SUCCESS         , if query is successfully registered
641  */
642 uint8_t gatt_client_read_value_of_characteristic(btstack_packet_handler_t callback, hci_con_handle_t con_handle, gatt_client_characteristic_t * characteristic);
643 
644 /**
645  * @brief Reads the characteristic value using the characteristic's value handle.
646  * If the characteristic value is found a GATT_EVENT_CHARACTERISTIC_VALUE_QUERY_RESULT event will be emitted.
647  * The GATT_EVENT_QUERY_COMPLETE event marks the end of read.
648  * @param  callback
649  * @param  con_handle
650  * @param  value_handle
651  * @return status BTSTACK_MEMORY_ALLOC_FAILED, if no GATT client for con_handle is found
652  *                GATT_CLIENT_IN_WRONG_STATE , if GATT client is not ready
653  *                ERROR_CODE_SUCCESS         , if query is successfully registered
654  */
655 uint8_t gatt_client_read_value_of_characteristic_using_value_handle(btstack_packet_handler_t callback, hci_con_handle_t con_handle, uint16_t value_handle);
656 
657 /**
658  * @brief Reads the characteric value of all characteristics with the uuid.
659  * For each characteristic value found a GATT_EVENT_CHARACTERISTIC_VALUE_QUERY_RESULT event will be emitted.
660  * The GATT_EVENT_QUERY_COMPLETE event marks the end of read.
661  * @param  callback
662  * @param  con_handle
663  * @param  start_handle
664  * @param  end_handle
665  * @param  uuid16
666  * @return status BTSTACK_MEMORY_ALLOC_FAILED, if no GATT client for con_handle is found
667  *                GATT_CLIENT_IN_WRONG_STATE , if GATT client is not ready
668  *                ERROR_CODE_SUCCESS         , if query is successfully registered
669  */
670 uint8_t gatt_client_read_value_of_characteristics_by_uuid16(btstack_packet_handler_t callback, hci_con_handle_t con_handle, uint16_t start_handle, uint16_t end_handle, uint16_t uuid16);
671 
672 /**
673  * @brief Reads the characteric value of all characteristics with the uuid.
674  * For each characteristic value found a GATT_EVENT_CHARACTERISTIC_VALUE_QUERY_RESULT event will be emitted.
675  * The GATT_EVENT_QUERY_COMPLETE event marks the end of read.
676  * @param  callback
677  * @param  con_handle
678  * @param  start_handle
679  * @param  end_handle
680  * @param  uuid128
681  * @return status BTSTACK_MEMORY_ALLOC_FAILED, if no GATT client for con_handle is found
682  *                GATT_CLIENT_IN_WRONG_STATE , if GATT client is not ready
683  *                ERROR_CODE_SUCCESS         , if query is successfully registered
684  */
685 uint8_t gatt_client_read_value_of_characteristics_by_uuid128(btstack_packet_handler_t callback, hci_con_handle_t con_handle, uint16_t start_handle, uint16_t end_handle, const uint8_t * uuid128);
686 
687 /**
688  * @brief Reads the long characteristic value using the characteristic's value handle.
689  * The value will be returned in several blobs.
690  * For each blob, a GATT_EVENT_LONG_CHARACTERISTIC_VALUE_QUERY_RESULT event with updated value offset will be emitted.
691  * The GATT_EVENT_QUERY_COMPLETE event marks the end of read.
692  * @param  callback
693  * @param  con_handle
694  * @param  characteristic
695  * @return status BTSTACK_MEMORY_ALLOC_FAILED, if no GATT client for con_handle is found
696  *                GATT_CLIENT_IN_WRONG_STATE , if GATT client is not ready
697  *                ERROR_CODE_SUCCESS         , if query is successfully registered
698  */
699 uint8_t gatt_client_read_long_value_of_characteristic(btstack_packet_handler_t callback, hci_con_handle_t con_handle, gatt_client_characteristic_t * characteristic);
700 
701 /**
702  * @brief Reads the long characteristic value using the characteristic's value handle.
703  * The value will be returned in several blobs.
704  * For each blob, a GATT_EVENT_LONG_CHARACTERISTIC_VALUE_QUERY_RESULT event with updated value offset will be emitted.
705  * The GATT_EVENT_QUERY_COMPLETE event marks the end of read.
706  * @param  callback
707  * @param  con_handle
708  * @param  value_handle
709  * @return status BTSTACK_MEMORY_ALLOC_FAILED, if no GATT client for con_handle is found
710  *                GATT_CLIENT_IN_WRONG_STATE , if GATT client is not ready
711  *                ERROR_CODE_SUCCESS         , if query is successfully registered
712  */
713 uint8_t gatt_client_read_long_value_of_characteristic_using_value_handle(btstack_packet_handler_t callback, hci_con_handle_t con_handle, uint16_t value_handle);
714 
715 /**
716  * @brief Reads the long characteristic value using the characteristic's value handle.
717  * The value will be returned in several blobs.
718  * For each blob, a GATT_EVENT_LONG_CHARACTERISTIC_VALUE_QUERY_RESULT event with updated value offset will be emitted.
719  * The GATT_EVENT_QUERY_COMPLETE event marks the end of read.
720  * @param  callback
721  * @param  con_handle
722  * @param  value_handle
723  * @param  offset
724  * @return status BTSTACK_MEMORY_ALLOC_FAILED, if no GATT client for con_handle is found
725  *                GATT_CLIENT_IN_WRONG_STATE , if GATT client is not ready
726  *                ERROR_CODE_SUCCESS         , if query is successfully registered
727  */
728 uint8_t gatt_client_read_long_value_of_characteristic_using_value_handle_with_offset(btstack_packet_handler_t callback, hci_con_handle_t con_handle, uint16_t value_handle, uint16_t offset);
729 
730 /*
731  * @brief Read multiple characteristic values.
732  * The all results are emitted via single GATT_EVENT_CHARACTERISTIC_VALUE_QUERY_RESULT event,
733  * followed by the GATT_EVENT_QUERY_COMPLETE event, which marks the end of read.
734  * @param  callback
735  * @param  con_handle
736  * @param  num_value_handles
737  * @param  value_handles list of handles
738  * @return status BTSTACK_MEMORY_ALLOC_FAILED, if no GATT client for con_handle is found
739  *                GATT_CLIENT_IN_WRONG_STATE , if GATT client is not ready
740  *                ERROR_CODE_SUCCESS         , if query is successfully registered
741  */
742 uint8_t gatt_client_read_multiple_characteristic_values(btstack_packet_handler_t callback, hci_con_handle_t con_handle, int num_value_handles, uint16_t * value_handles);
743 
744 /*
745  * @brief Read multiple varaible characteristic values. Only supported over LE Enhanced Bearer
746  * The all results are emitted via single GATT_EVENT_CHARACTERISTIC_VALUE_QUERY_RESULT event,
747  * followed by the GATT_EVENT_QUERY_COMPLETE event, which marks the end of read.
748  * @param  callback
749  * @param  con_handle
750  * @param  num_value_handles
751  * @param  value_handles list of handles
752  * @return status BTSTACK_MEMORY_ALLOC_FAILED, if no GATT client for con_handle is found
753  *                GATT_CLIENT_IN_WRONG_STATE , if GATT client is not ready
754  *                ERROR_CODE_SUCCESS         , if query is successfully registered
755  */
756 uint8_t gatt_client_read_multiple_variable_characteristic_values(btstack_packet_handler_t callback, hci_con_handle_t con_handle, int num_value_handles, uint16_t * value_handles);
757 
758 /**
759  * @brief Writes the characteristic value using the characteristic's value handle without
760  * an acknowledgment that the write was successfully performed.
761  * @param  con_handle
762  * @param  value_handle
763  * @param  value_length
764  * @param  value is copied on success and does not need to be retained
765  * @return status BTSTACK_MEMORY_ALLOC_FAILED, if no GATT client for con_handle is found
766  *                GATT_CLIENT_IN_WRONG_STATE , if GATT client is not ready
767  *                BTSTACK_ACL_BUFFERS_FULL   , if L2CAP cannot send, there are no free ACL slots
768  *                ERROR_CODE_SUCCESS         , if query is successfully registered
769  */
770 uint8_t gatt_client_write_value_of_characteristic_without_response(hci_con_handle_t con_handle, uint16_t value_handle, uint16_t value_length, uint8_t * value);
771 
772 /**
773  * @brief Writes the authenticated characteristic value using the characteristic's value handle
774  * without an acknowledgment that the write was successfully performed.
775  * @note GATT_EVENT_QUERY_COMPLETE is emitted with ATT_ERROR_SUCCESS for success,
776  * or ATT_ERROR_BONDING_INFORMATION_MISSING if there is no bonding information stored.
777  * @param  callback
778  * @param  con_handle
779  * @param  value_handle
780  * @param  message_len
781  * @param  message is not copied, make sure memory is accessible until write is done
782  * @return status ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER                  if no HCI connection for con_handle is found
783  *                BTSTACK_MEMORY_ALLOC_FAILED                               if no GATT client for con_handle could be allocated
784  *                GATT_CLIENT_IN_WRONG_STATE                                if GATT client is not ready
785  *                ERROR_CODE_SUCCESS                                        if query is successfully registered
786  */
787 uint8_t gatt_client_signed_write_without_response(btstack_packet_handler_t callback, hci_con_handle_t con_handle, uint16_t value_handle, uint16_t message_len, uint8_t * message);
788 
789 /**
790  * @brief Writes the characteristic value using the characteristic's value handle.
791  * The GATT_EVENT_QUERY_COMPLETE event marks the end of write.
792  * The write is successfully performed, if the event's att_status field is set to
793  * ATT_ERROR_SUCCESS (see bluetooth.h for ATT_ERROR codes).
794  * @param  callback
795  * @param  con_handle
796  * @param  value_handle
797  * @param  value_length
798  * @param  value is not copied, make sure memory is accessible until write is done, i.e. GATT_EVENT_QUERY_COMPLETE is received
799  * @return status ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER                  if no HCI connection for con_handle is found
800  *                BTSTACK_MEMORY_ALLOC_FAILED                               if no GATT client for con_handle could be allocated
801  *                GATT_CLIENT_IN_WRONG_STATE                                if GATT client is not ready
802  *                ERROR_CODE_SUCCESS                                        if query is successfully registered
803  */
804 uint8_t gatt_client_write_value_of_characteristic(btstack_packet_handler_t callback, hci_con_handle_t con_handle, uint16_t value_handle, uint16_t value_length, uint8_t * value);
805 
806 /**
807  * @brief Writes the characteristic value using the characteristic's value handle.
808  * The GATT_EVENT_QUERY_COMPLETE event marks the end of write.
809  * The write is successfully performed if the event's att_status field is set to ATT_ERROR_SUCCESS (see bluetooth.h for ATT_ERROR codes).
810  * @param  callback
811  * @param  con_handle
812  * @param  value_handle
813  * @param  value_length
814  * @param  value is not copied, make sure memory is accessible until write is done, i.e. GATT_EVENT_QUERY_COMPLETE is received
815  * @return status ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER                  if no HCI connection for con_handle is found
816  *                BTSTACK_MEMORY_ALLOC_FAILED                               if no GATT client for con_handle could be allocated
817  *                GATT_CLIENT_IN_WRONG_STATE                                if GATT client is not ready
818  *                ERROR_CODE_SUCCESS                                        if query is successfully registered
819  */
820 uint8_t gatt_client_write_long_value_of_characteristic(btstack_packet_handler_t callback, hci_con_handle_t con_handle, uint16_t value_handle, uint16_t value_length, uint8_t * value);
821 
822 /**
823  * @brief Writes the characteristic value using the characteristic's value handle.
824  * The GATT_EVENT_QUERY_COMPLETE event marks the end of write.
825  * The write is successfully performed if the event's att_status field is set to ATT_ERROR_SUCCESS (see bluetooth.h for ATT_ERROR codes).
826  * @param  callback
827  * @param  con_handle
828  * @param  value_handle
829  * @param  offset of value
830  * @param  value_length
831  * @param  value is not copied, make sure memory is accessible until write is done, i.e. GATT_EVENT_QUERY_COMPLETE is received
832  * @return status ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER                  if no HCI connection for con_handle is found
833  *                BTSTACK_MEMORY_ALLOC_FAILED                               if no GATT client for con_handle could be allocated
834  *                GATT_CLIENT_IN_WRONG_STATE                                if GATT client is not ready
835  *                ERROR_CODE_SUCCESS                                        if query is successfully registered
836  */
837 uint8_t gatt_client_write_long_value_of_characteristic_with_offset(btstack_packet_handler_t callback, hci_con_handle_t con_handle, uint16_t value_handle, uint16_t offset, uint16_t value_length, uint8_t * value);
838 
839 /**
840  * @brief Writes of the long characteristic value using the characteristic's value handle.
841  * It uses server response to validate that the write was correctly received.
842  * The GATT_EVENT_QUERY_COMPLETE EVENT marks the end of write.
843  * The write is successfully performed, if the event's att_status field is set to ATT_ERROR_SUCCESS (see bluetooth.h for ATT_ERROR codes).
844  * @param  callback
845  * @param  con_handle
846  * @param  value_handle
847  * @param  value_length
848  * @param  value is not copied, make sure memory is accessible until write is done, i.e. GATT_EVENT_QUERY_COMPLETE is received
849  * @return status ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER                  if no HCI connection for con_handle is found
850  *                BTSTACK_MEMORY_ALLOC_FAILED                               if no GATT client for con_handle could be allocated
851  *                GATT_CLIENT_IN_WRONG_STATE                                if GATT client is not ready
852  *                ERROR_CODE_SUCCESS                                        if query is successfully registered
853  */
854 uint8_t gatt_client_reliable_write_long_value_of_characteristic(btstack_packet_handler_t callback, hci_con_handle_t con_handle, uint16_t value_handle, uint16_t value_length, uint8_t * value);
855 
856 /**
857  * @brief Reads the characteristic descriptor using its handle.
858  * If the characteristic descriptor is found, a GATT_EVENT_CHARACTERISTIC_DESCRIPTOR_QUERY_RESULT event will be emitted.
859  * The GATT_EVENT_QUERY_COMPLETE event marks the end of read.
860  * @param  callback
861  * @param  con_handle
862  * @param  descriptor
863  * @return status ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER                  if no HCI connection for con_handle is found
864  *                BTSTACK_MEMORY_ALLOC_FAILED                               if no GATT client for con_handle could be allocated
865  *                GATT_CLIENT_IN_WRONG_STATE                                if GATT client is not ready
866  *                ERROR_CODE_SUCCESS                                        if query is successfully registered
867  */
868 uint8_t gatt_client_read_characteristic_descriptor(btstack_packet_handler_t callback, hci_con_handle_t con_handle, gatt_client_characteristic_descriptor_t * descriptor);
869 
870 /**
871  * @brief Reads the characteristic descriptor using its handle.
872  * If the characteristic descriptor is found, a GATT_EVENT_CHARACTERISTIC_DESCRIPTOR_QUERY_RESULT event will be emitted.
873  * The GATT_EVENT_QUERY_COMPLETE event marks the end of read.
874  * @param  callback
875  * @param  con_handle
876  * @param  descriptor
877  * @return status ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER                  if no HCI connection for con_handle is found
878  *                BTSTACK_MEMORY_ALLOC_FAILED                               if no GATT client for con_handle could be allocated
879  *                GATT_CLIENT_IN_WRONG_STATE                                if GATT client is not ready
880  *                ERROR_CODE_SUCCESS                                        if query is successfully registered
881  */
882 uint8_t gatt_client_read_characteristic_descriptor_using_descriptor_handle(btstack_packet_handler_t callback, hci_con_handle_t con_handle, uint16_t descriptor_handle);
883 
884 /**
885  * @brief Reads the long characteristic descriptor using its handle. It will be returned in several blobs.
886  * For each blob, a GATT_EVENT_CHARACTERISTIC_DESCRIPTOR_QUERY_RESULT event will be emitted.
887  * The GATT_EVENT_QUERY_COMPLETE event marks the end of read.
888  * @param  callback
889  * @param  con_handle
890  * @param  descriptor
891  * @return status ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER                  if no HCI connection for con_handle is found
892  *                BTSTACK_MEMORY_ALLOC_FAILED                               if no GATT client for con_handle could be allocated
893  *                GATT_CLIENT_IN_WRONG_STATE                                if GATT client is not ready
894  *                ERROR_CODE_SUCCESS                                        if query is successfully registered
895  */
896 uint8_t gatt_client_read_long_characteristic_descriptor(btstack_packet_handler_t callback, hci_con_handle_t con_handle, gatt_client_characteristic_descriptor_t * descriptor);
897 
898 /**
899  * @brief Reads the long characteristic descriptor using its handle. It will be returned in several blobs.
900  * For each blob, a GATT_EVENT_CHARACTERISTIC_DESCRIPTOR_QUERY_RESULT event will be emitted.
901  * The GATT_EVENT_QUERY_COMPLETE event marks the end of read.
902  * @param  callback
903  * @param  con_handle
904  * @param  descriptor_handle
905  * @return status ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER                  if no HCI connection for con_handle is found
906  *                BTSTACK_MEMORY_ALLOC_FAILED                               if no GATT client for con_handle could be allocated
907  *                GATT_CLIENT_IN_WRONG_STATE                                if GATT client is not ready
908  *                ERROR_CODE_SUCCESS                                        if query is successfully registered
909  */
910 uint8_t gatt_client_read_long_characteristic_descriptor_using_descriptor_handle(btstack_packet_handler_t callback, hci_con_handle_t con_handle, uint16_t descriptor_handle);
911 
912 /**
913  * @brief Reads the long characteristic descriptor using its handle. It will be returned in several blobs.
914  * For each blob, a GATT_EVENT_CHARACTERISTIC_DESCRIPTOR_QUERY_RESULT event will be emitted.
915  * The GATT_EVENT_QUERY_COMPLETE event marks the end of read.
916  * @param  callback
917  * @param  con_handle
918  * @param  descriptor_handle
919  * @param  offset
920  * @return status ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER                  if no HCI connection for con_handle is found
921  *                BTSTACK_MEMORY_ALLOC_FAILED                               if no GATT client for con_handle could be allocated
922  *                GATT_CLIENT_IN_WRONG_STATE                                if GATT client is not ready
923  *                ERROR_CODE_SUCCESS                                        if query is successfully registered
924  */
925 uint8_t gatt_client_read_long_characteristic_descriptor_using_descriptor_handle_with_offset(btstack_packet_handler_t callback, hci_con_handle_t con_handle, uint16_t descriptor_handle, uint16_t offset);
926 
927 /**
928  * @brief Writes the characteristic descriptor using its handle.
929  * The GATT_EVENT_QUERY_COMPLETE event marks the end of write.
930  * The write is successfully performed if the event's att_status field is set to ATT_ERROR_SUCCESS (see bluetooth.h for ATT_ERROR codes).
931  * @param  callback
932  * @param  con_handle
933  * @param  descriptor
934  * @param  value_length
935  * @param  value is not copied, make sure memory is accessible until write is done, i.e. GATT_EVENT_QUERY_COMPLETE is received
936  * @return status ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER                  if no HCI connection for con_handle is found
937  *                BTSTACK_MEMORY_ALLOC_FAILED                               if no GATT client for con_handle could be allocated
938  *                GATT_CLIENT_IN_WRONG_STATE                                if GATT client is not ready
939  *                ERROR_CODE_SUCCESS                                        if query is successfully registered
940  */
941 uint8_t gatt_client_write_characteristic_descriptor(btstack_packet_handler_t callback, hci_con_handle_t con_handle, gatt_client_characteristic_descriptor_t * descriptor, uint16_t value_length, uint8_t * value);
942 
943 /**
944  * @brief Writes the characteristic descriptor using its handle.
945  * The GATT_EVENT_QUERY_COMPLETE event marks the end of write.
946  * The write is successfully performed if the event's att_status field is set to ATT_ERROR_SUCCESS (see bluetooth.h for ATT_ERROR codes).
947  * @param  callback
948  * @param  con_handle
949  * @param  descriptor_handle
950  * @param  value_length
951  * @param  value is not copied, make sure memory is accessible until write is done, i.e. GATT_EVENT_QUERY_COMPLETE is received
952  * @return status ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER                  if no HCI connection for con_handle is found
953  *                BTSTACK_MEMORY_ALLOC_FAILED                               if no GATT client for con_handle could be allocated
954  *                GATT_CLIENT_IN_WRONG_STATE                                if GATT client is not ready
955  *                ERROR_CODE_SUCCESS                                        if query is successfully registered
956  */
957 uint8_t gatt_client_write_characteristic_descriptor_using_descriptor_handle(btstack_packet_handler_t callback, hci_con_handle_t con_handle, uint16_t descriptor_handle, uint16_t value_length, uint8_t * value);
958 
959 /**
960  * @brief Writes the characteristic descriptor using its handle.
961  * The GATT_EVENT_QUERY_COMPLETE event marks the end of write.
962  * The write is successfully performed if the event's att_status field is set to ATT_ERROR_SUCCESS (see bluetooth.h for ATT_ERROR codes).
963  * @param  callback
964  * @param  con_handle
965  * @param  descriptor
966  * @param  value_length
967  * @param  value is not copied, make sure memory is accessible until write is done, i.e. GATT_EVENT_QUERY_COMPLETE is received
968  * @return status ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER                  if no HCI connection for con_handle is found
969  *                BTSTACK_MEMORY_ALLOC_FAILED                               if no GATT client for con_handle could be allocated
970  *                GATT_CLIENT_IN_WRONG_STATE                                if GATT client is not ready
971  *                ERROR_CODE_SUCCESS                                        if query is successfully registered
972  */
973 uint8_t gatt_client_write_long_characteristic_descriptor(btstack_packet_handler_t callback, hci_con_handle_t con_handle, gatt_client_characteristic_descriptor_t * descriptor, uint16_t value_length, uint8_t * value);
974 
975 /**
976  * @brief Writes the characteristic descriptor using its handle.
977  * The GATT_EVENT_QUERY_COMPLETE event marks the end of write.
978  * The write is successfully performed if the event's att_status field is set to ATT_ERROR_SUCCESS (see bluetooth.h for ATT_ERROR codes).
979  * @param  callback
980  * @param  con_handle
981  * @param  descriptor_handle
982  * @param  value_length
983  * @param  value is not copied, make sure memory is accessible until write is done, i.e. GATT_EVENT_QUERY_COMPLETE is received
984  * @return status ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER                  if no HCI connection for con_handle is found
985  *                BTSTACK_MEMORY_ALLOC_FAILED                               if no GATT client for con_handle could be allocated
986  *                GATT_CLIENT_IN_WRONG_STATE                                if GATT client is not ready
987  *                ERROR_CODE_SUCCESS                                        if query is successfully registered
988  */
989 uint8_t gatt_client_write_long_characteristic_descriptor_using_descriptor_handle(btstack_packet_handler_t callback, hci_con_handle_t con_handle, uint16_t descriptor_handle, uint16_t value_length, uint8_t * value);
990 
991 /**
992  * @brief Writes the characteristic descriptor using its handle.
993  * The GATT_EVENT_QUERY_COMPLETE event marks the end of write.
994  * The write is successfully performed if the event's att_status field is set to ATT_ERROR_SUCCESS (see bluetooth.h for ATT_ERROR codes).
995  * @param  callback
996  * @param  con_handle
997  * @param  descriptor_handle
998  * @param  offset of value
999  * @param  value_length
1000  * @param  value is not copied, make sure memory is accessible until write is done, i.e. GATT_EVENT_QUERY_COMPLETE is received
1001  * @return status ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER                  if no HCI connection for con_handle is found
1002  *                BTSTACK_MEMORY_ALLOC_FAILED                               if no GATT client for con_handle could be allocated
1003  *                GATT_CLIENT_IN_WRONG_STATE                                if GATT client is not ready
1004  *                ERROR_CODE_SUCCESS                                        if query is successfully registered
1005  */
1006 uint8_t gatt_client_write_long_characteristic_descriptor_using_descriptor_handle_with_offset(btstack_packet_handler_t callback, hci_con_handle_t con_handle, uint16_t descriptor_handle, uint16_t offset, uint16_t value_length, uint8_t * value);
1007 
1008 /**
1009  * @brief Writes the client characteristic configuration of the specified characteristic.
1010  * It is used to subscribe for notifications or indications of the characteristic value.
1011  * For notifications or indications specify: GATT_CLIENT_CHARACTERISTICS_CONFIGURATION_NOTIFICATION
1012  * resp. GATT_CLIENT_CHARACTERISTICS_CONFIGURATION_INDICATION as configuration value.
1013  * The GATT_EVENT_QUERY_COMPLETE event marks the end of write.
1014  * The write is successfully performed if the event's att_status field is set to ATT_ERROR_SUCCESS (see bluetooth.h for ATT_ERROR codes).
1015  * @param  callback
1016  * @param  con_handle
1017  * @param  characteristic
1018  * @param  configuration                                                    GATT_CLIENT_CHARACTERISTICS_CONFIGURATION_NOTIFICATION, GATT_CLIENT_CHARACTERISTICS_CONFIGURATION_INDICATION
1019  * @return status ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER                  if no HCI connection for con_handle is found
1020  *                BTSTACK_MEMORY_ALLOC_FAILED                               if no GATT client for con_handle could be allocated
1021  *                GATT_CLIENT_IN_WRONG_STATE                                if GATT client is not ready
1022  *                GATT_CLIENT_CHARACTERISTIC_NOTIFICATION_NOT_SUPPORTED     if configuring notification, but characteristic has no notification property set
1023  *                GATT_CLIENT_CHARACTERISTIC_INDICATION_NOT_SUPPORTED       if configuring indication, but characteristic has no indication property set
1024  *                ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE         if configuration is invalid
1025  *                ERROR_CODE_SUCCESS                                        if query is successfully registered
1026  */
1027 uint8_t gatt_client_write_client_characteristic_configuration(btstack_packet_handler_t callback, hci_con_handle_t con_handle, gatt_client_characteristic_t * characteristic, uint16_t configuration);
1028 
1029 /**
1030  * @brief Register for changes to the Service Changed and Database Hash Characteristics of the remote GATT Service
1031  * *
1032  * When configured, GATT_EVENT_QUERY_COMPLETE event is emitted
1033  * If supported, the Database Hash is read as well
1034  *
1035  * Requires ENABLE_GATT_CLIENT_SERVICE_CHANGED
1036  *
1037  * @param callback
1038  */
1039 void gatt_client_add_service_changed_handler(btstack_packet_callback_registration_t * callback);
1040 
1041 /**
1042  * @brief Remove callback for service changes
1043  *
1044  * Requires ENABLE_GATT_CLIENT_SERVICE_CHANGED
1045  *
1046  * @param callback
1047  */
1048 void gatt_client_remove_service_changed_handler(btstack_packet_callback_registration_t * callback);
1049 
1050 /**
1051  * @brief Register for notifications and indications of a characteristic enabled by
1052  * the gatt_client_write_client_characteristic_configuration function.
1053  * @param notification struct used to store registration
1054  * @param callback
1055  * @param con_handle or GATT_CLIENT_ANY_CONNECTION to receive updates from all connected devices
1056  * @param characteristic or NULL to receive updates for all characteristics
1057  */
1058 void gatt_client_listen_for_characteristic_value_updates(gatt_client_notification_t * notification, btstack_packet_handler_t callback, hci_con_handle_t con_handle, gatt_client_characteristic_t * characteristic);
1059 
1060 /**
1061  * @brief Stop listening to characteristic value updates registered with
1062  * the gatt_client_listen_for_characteristic_value_updates function.
1063  * @param notification struct used in gatt_client_listen_for_characteristic_value_updates
1064  */
1065 void gatt_client_stop_listening_for_characteristic_value_updates(gatt_client_notification_t * notification);
1066 
1067 /**
1068  * @brief Transactional write. It can be called as many times as it is needed to write the characteristics within the same transaction.
1069  * Call the gatt_client_execute_write function to commit the transaction.
1070  * @param  callback
1071  * @param  con_handle
1072  * @param  attribute_handle
1073  * @param  offset of value
1074  * @param  value_length
1075  * @param  value is not copied, make sure memory is accessible until write is done, i.e. GATT_EVENT_QUERY_COMPLETE is received
1076  */
1077 uint8_t gatt_client_prepare_write(btstack_packet_handler_t callback, hci_con_handle_t con_handle, uint16_t attribute_handle, uint16_t offset, uint16_t value_length, uint8_t * value);
1078 
1079 /**
1080  * @brief Commit transactional write. GATT_EVENT_QUERY_COMPLETE is received.
1081  * @param  callback
1082  * @param  con_handle
1083  * @return status
1084  */
1085 uint8_t gatt_client_execute_write(btstack_packet_handler_t callback, hci_con_handle_t con_handle);
1086 
1087 /**
1088  * @brief Abort transactional write. GATT_EVENT_QUERY_COMPLETE is received.
1089  * @param  callback
1090  * @param  con_handle
1091  * @return status
1092  */
1093 uint8_t gatt_client_cancel_write(btstack_packet_handler_t callback, hci_con_handle_t con_handle);
1094 
1095 /**
1096  * @brief Request callback when regular gatt query can be sent
1097  * @note callback might happen during call to this function
1098  * @param callback_registration to point to callback function and context information
1099  * @param con_handle
1100  * @return ERROR_CODE_SUCCESS if ok, ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER if handle unknown, and ERROR_CODE_COMMAND_DISALLOWED if callback already registered
1101  */
1102 uint8_t gatt_client_request_to_send_gatt_query(btstack_context_callback_registration_t * callback_registration, hci_con_handle_t con_handle);
1103 
1104 /**
1105  * @brief Remove queued callback for regular gatt queries, to be used on disconnect for example
1106  * @param callback_registration
1107  * @param con_handle
1108  * @return ERROR_CODE_SUCCESS if ok
1109  */
1110 uint8_t gatt_client_remove_gatt_query(btstack_context_callback_registration_t * callback_registration, hci_con_handle_t con_handle);
1111 
1112 /**
1113  * @brief Request callback when writing characteristic value without response is possible
1114  * @note callback might happen during call to this function
1115  * @param callback_registration to point to callback function and context information
1116  * @param con_handle
1117  * @return ERROR_CODE_SUCCESS if ok, ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER if handle unknown, and ERROR_CODE_COMMAND_DISALLOWED if callback already registered
1118  */
1119 uint8_t gatt_client_request_to_write_without_response(btstack_context_callback_registration_t * callback_registration, hci_con_handle_t con_handle);
1120 
1121 
1122 // the following functions are marked as deprecated and will be removed eventually
1123 /**
1124  * @brief Requests GATT_EVENT_CAN_WRITE_WITHOUT_RESPONSE that guarantees
1125  * a single successful gatt_client_write_value_of_characteristic_without_response call.
1126  * @deprecated please use gatt_client_request_to_write_without_response instead
1127  * @param  callback
1128  * @param  con_handle
1129  * @return status
1130  */
1131 uint8_t gatt_client_request_can_write_without_response_event(btstack_packet_handler_t callback, hci_con_handle_t con_handle);
1132 
1133 
1134 /* API_END */
1135 
1136 // used by generated btstack_event.c
1137 
1138 void gatt_client_deserialize_service(const uint8_t *packet, int offset, gatt_client_service_t * service);
1139 void gatt_client_deserialize_characteristic(const uint8_t * packet, int offset, gatt_client_characteristic_t * characteristic);
1140 void gatt_client_deserialize_characteristic_descriptor(const uint8_t * packet, int offset, gatt_client_characteristic_descriptor_t * descriptor);
1141 
1142 #ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
1143 void gatt_client_att_packet_handler_fuzz(uint8_t packet_type, uint16_t handle, uint8_t *packet, uint16_t size);
1144 uint8_t gatt_client_get_client(hci_con_handle_t con_handle, gatt_client_t ** gatt_client);
1145 #endif
1146 
1147 #if defined __cplusplus
1148 }
1149 #endif
1150 
1151 #endif
1152