xref: /btstack/src/ble/gatt_client.h (revision e8b7768f4320b89e088aeff6b8ffd5c9b51f3338)
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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_SEND_SERVICE_QUERY,
57     P_W4_SERVICE_QUERY_RESULT,
58     P_W2_SEND_SERVICE_WITH_UUID_QUERY,
59     P_W4_SERVICE_WITH_UUID_RESULT,
60 
61     P_W2_SEND_ALL_CHARACTERISTICS_OF_SERVICE_QUERY,
62     P_W4_ALL_CHARACTERISTICS_OF_SERVICE_QUERY_RESULT,
63     P_W2_SEND_CHARACTERISTIC_WITH_UUID_QUERY,
64     P_W4_CHARACTERISTIC_WITH_UUID_QUERY_RESULT,
65 
66     P_W2_SEND_ALL_CHARACTERISTIC_DESCRIPTORS_QUERY,
67     P_W4_ALL_CHARACTERISTIC_DESCRIPTORS_QUERY_RESULT,
68 
69     P_W2_SEND_INCLUDED_SERVICE_QUERY,
70     P_W4_INCLUDED_SERVICE_QUERY_RESULT,
71     P_W2_SEND_INCLUDED_SERVICE_WITH_UUID_QUERY,
72     P_W4_INCLUDED_SERVICE_UUID_WITH_QUERY_RESULT,
73 
74     P_W2_SEND_READ_CHARACTERISTIC_VALUE_QUERY,
75     P_W4_READ_CHARACTERISTIC_VALUE_RESULT,
76 
77     P_W2_SEND_READ_BLOB_QUERY,
78     P_W4_READ_BLOB_RESULT,
79 
80     P_W2_SEND_READ_BY_TYPE_REQUEST,
81     P_W4_READ_BY_TYPE_RESPONSE,
82 
83     P_W2_SEND_READ_MULTIPLE_REQUEST,
84     P_W4_READ_MULTIPLE_RESPONSE,
85 
86     P_W2_SEND_READ_MULTIPLE_VARIABLE_REQUEST,
87     P_W4_READ_MULTIPLE_VARIABLE_RESPONSE,
88 
89     P_W2_SEND_WRITE_CHARACTERISTIC_VALUE,
90     P_W4_WRITE_CHARACTERISTIC_VALUE_RESULT,
91 
92     P_W2_PREPARE_WRITE,
93     P_W4_PREPARE_WRITE_RESULT,
94     P_W2_PREPARE_RELIABLE_WRITE,
95     P_W4_PREPARE_RELIABLE_WRITE_RESULT,
96 
97     P_W2_EXECUTE_PREPARED_WRITE,
98     P_W4_EXECUTE_PREPARED_WRITE_RESULT,
99     P_W2_CANCEL_PREPARED_WRITE,
100     P_W4_CANCEL_PREPARED_WRITE_RESULT,
101     P_W2_CANCEL_PREPARED_WRITE_DATA_MISMATCH,
102     P_W4_CANCEL_PREPARED_WRITE_DATA_MISMATCH_RESULT,
103 
104 #ifdef ENABLE_GATT_FIND_INFORMATION_FOR_CCC_DISCOVERY
105     P_W2_SEND_FIND_CLIENT_CHARACTERISTIC_CONFIGURATION_QUERY,
106     P_W4_FIND_CLIENT_CHARACTERISTIC_CONFIGURATION_QUERY_RESULT,
107 #else
108     P_W2_SEND_READ_CLIENT_CHARACTERISTIC_CONFIGURATION_QUERY,
109     P_W4_READ_CLIENT_CHARACTERISTIC_CONFIGURATION_QUERY_RESULT,
110 #endif
111     P_W2_WRITE_CLIENT_CHARACTERISTIC_CONFIGURATION,
112     P_W4_CLIENT_CHARACTERISTIC_CONFIGURATION_RESULT,
113 
114     P_W2_SEND_READ_CHARACTERISTIC_DESCRIPTOR_QUERY,
115     P_W4_READ_CHARACTERISTIC_DESCRIPTOR_RESULT,
116 
117     P_W2_SEND_READ_BLOB_CHARACTERISTIC_DESCRIPTOR_QUERY,
118     P_W4_READ_BLOB_CHARACTERISTIC_DESCRIPTOR_RESULT,
119 
120     P_W2_SEND_WRITE_CHARACTERISTIC_DESCRIPTOR,
121     P_W4_WRITE_CHARACTERISTIC_DESCRIPTOR_RESULT,
122 
123     // all long writes use this
124     P_W2_PREPARE_WRITE_CHARACTERISTIC_DESCRIPTOR,
125     P_W4_PREPARE_WRITE_CHARACTERISTIC_DESCRIPTOR_RESULT,
126     P_W2_EXECUTE_PREPARED_WRITE_CHARACTERISTIC_DESCRIPTOR,
127     P_W4_EXECUTE_PREPARED_WRITE_CHARACTERISTIC_DESCRIPTOR_RESULT,
128 
129     // gatt reliable write API use this (manual version of the above)
130     P_W2_PREPARE_WRITE_SINGLE,
131     P_W4_PREPARE_WRITE_SINGLE_RESULT,
132 
133     P_W4_IDENTITY_RESOLVING,
134     P_W4_CMAC_READY,
135     P_W4_CMAC_RESULT,
136     P_W2_SEND_SIGNED_WRITE,
137     P_W4_SEND_SINGED_WRITE_DONE,
138 
139     P_W2_SDP_QUERY,
140     P_W4_SDP_QUERY,
141     P_W2_L2CAP_CONNECT,
142     P_W4_L2CAP_CONNECTION,
143     P_W2_EMIT_CONNECTED,
144     P_L2CAP_CLOSED,
145 } gatt_client_state_t;
146 
147 
148 typedef enum{
149     SEND_MTU_EXCHANGE,
150     SENT_MTU_EXCHANGE,
151     MTU_EXCHANGED,
152     MTU_AUTO_EXCHANGE_DISABLED
153 } gatt_client_mtu_t;
154 
155 #ifdef ENABLE_GATT_OVER_EATT
156 typedef enum {
157     GATT_CLIENT_EATT_IDLE,
158     GATT_CLIENT_EATT_DISCOVER_GATT_SERVICE_W2_SEND,
159     GATT_CLIENT_EATT_DISCOVER_GATT_SERVICE_W4_DONE,
160     GATT_CLIENT_EATT_READ_SERVER_SUPPORTED_FEATURES_W2_SEND,
161     GATT_CLIENT_EATT_READ_SERVER_SUPPORTED_FEATURES_W4_DONE,
162     GATT_CLIENT_EATT_FIND_CLIENT_SUPPORTED_FEATURES_W2_SEND,
163     GATT_CLIENT_EATT_FIND_CLIENT_SUPPORTED_FEATURES_W4_DONE,
164     GATT_CLIENT_EATT_WRITE_ClIENT_SUPPORTED_FEATURES_W2_SEND,
165     GATT_CLIENT_EATT_WRITE_ClIENT_SUPPORTED_FEATURES_W4_DONE,
166     GATT_CLIENT_EATT_L2CAP_SETUP,
167     GATT_CLIENT_EATT_READY,
168 } gatt_client_eatt_state_t;
169 #endif
170 
171 typedef struct gatt_client{
172     btstack_linked_item_t    item;
173     // TODO: rename gatt_client_state -> state
174     gatt_client_state_t state;
175 
176     // user callback
177     btstack_packet_handler_t callback;
178 
179     // can write without response callback
180     btstack_packet_handler_t write_without_response_callback;
181 
182     // can write without response requests
183     btstack_linked_list_t write_without_response_requests;
184 
185     // regular gatt query requests
186     btstack_linked_list_t query_requests;
187 
188     hci_con_handle_t con_handle;
189 
190     att_bearer_type_t bearer_type;
191 
192 #ifdef ENABLE_GATT_OVER_CLASSIC
193     bd_addr_t addr;
194     uint16_t  l2cap_psm;
195     uint16_t  l2cap_cid;
196     btstack_context_callback_registration_t callback_request;
197 #endif
198 
199 #ifdef ENABLE_GATT_OVER_EATT
200     gatt_client_eatt_state_t eatt_state;
201     btstack_linked_list_t eatt_clients;
202     uint8_t * eatt_storage_buffer;
203     uint16_t eatt_storage_size;
204     uint8_t  eatt_num_clients;
205     uint8_t  gatt_server_supported_features;
206     uint16_t gatt_service_start_group_handle;
207     uint16_t gatt_service_end_group_handle;
208     uint16_t gatt_client_supported_features_handle;
209 #endif
210 
211     uint16_t          mtu;
212     gatt_client_mtu_t mtu_state;
213 
214     uint16_t uuid16;
215     uint8_t  uuid128[16];
216 
217     uint16_t start_group_handle;
218     uint16_t end_group_handle;
219 
220     uint16_t query_start_handle;
221     uint16_t query_end_handle;
222 
223     uint8_t  characteristic_properties;
224     uint16_t characteristic_start_handle;
225 
226     uint16_t attribute_handle;
227     uint16_t attribute_offset;
228     uint16_t attribute_length;
229     uint8_t* attribute_value;
230 
231     // read multiple characteristic values
232     uint16_t    read_multiple_handle_count;
233     uint16_t  * read_multiple_handles;
234 
235     uint16_t client_characteristic_configuration_handle;
236     uint8_t  client_characteristic_configuration_value[2];
237 
238     uint8_t  filter_with_uuid;
239     uint8_t  send_confirmation;
240 
241     int      le_device_index;
242     uint8_t  cmac[8];
243 
244     btstack_timer_source_t gc_timeout;
245 
246     uint8_t  security_counter;
247     uint8_t  wait_for_authentication_complete;
248     uint8_t  pending_error_code;
249 
250     bool     reencryption_active;
251     uint8_t  reencryption_result;
252 
253     gap_security_level_t security_level;
254 
255 } gatt_client_t;
256 
257 typedef struct gatt_client_notification {
258     btstack_linked_item_t    item;
259     btstack_packet_handler_t callback;
260     hci_con_handle_t con_handle;
261     uint16_t attribute_handle;
262 } gatt_client_notification_t;
263 
264 /* API_START */
265 
266 typedef struct {
267     uint16_t start_group_handle;
268     uint16_t end_group_handle;
269     uint16_t uuid16;
270     uint8_t  uuid128[16];
271 } gatt_client_service_t;
272 
273 typedef struct {
274     uint16_t start_handle;
275     uint16_t value_handle;
276     uint16_t end_handle;
277     uint16_t properties;
278     uint16_t uuid16;
279     uint8_t  uuid128[16];
280 } gatt_client_characteristic_t;
281 
282 typedef struct {
283     uint16_t handle;
284     uint16_t uuid16;
285     uint8_t  uuid128[16];
286 } gatt_client_characteristic_descriptor_t;
287 
288 /**
289  * @brief Set up GATT client.
290  */
291 void gatt_client_init(void);
292 
293 /**
294  * @brief Set minimum required security level for GATT Client
295  * @note  The Bluetooth specification makes the GATT Server responsible to check for security.
296  *        This allows an attacker to spoof an existing device with a GATT Servers, but skip the authentication part.
297  *        If your application is exchanging sensitive data with a remote device, you would need to manually check
298  *        the security level before sending/receive such data.
299  *        With level > 0, the GATT Client triggers authentication for all GATT Requests and defers any exchange
300  *        until the required security level is established.
301  *        gatt_client_request_can_write_without_response_event does not trigger authentication
302  *        gatt_client_request_to_write_without_response does not trigger authentication
303  *  @pram level, default LEVEL_0 (no encryption required)
304  */
305 void gatt_client_set_required_security_level(gap_security_level_t level);
306 
307 /**
308  * @brief Connect to remote GATT Server over Classic (BR/EDR) Connection
309  *        GATT_EVENT_CONNECTED with status and con_handle for other API functions
310  *        is emitted on connection complete.
311  * @note requires ENABLE_GATT_OVER_CLASSIC.
312  * @param addr
313  * @return status
314  */
315 uint8_t gatt_client_classic_connect(btstack_packet_handler_t callback, bd_addr_t addr);
316 
317 /**
318  * @brief Disconnect o Classic (BR/EDR) connection to a remote GATT Server
319  * @note requires ENABLE_GATT_OVER_CLASSIC
320  * @param con_handle
321  * @return status
322  */
323 uint8_t gatt_client_classic_disconnect(btstack_packet_handler_t callback, hci_con_handle_t con_handle);
324 
325 /**
326  * @brief Setup Enhanced LE Bearer with up to 5 channels on existing LE connection
327  * @param callback for GATT_EVENT_CONNECTED and GATT_EVENT_DISCONNECTED events
328  * @param con_handle
329  * @param num_channels
330  * @param storage_buffer for L2CAP connection
331  * @param storage_size - each channel requires (2 * ATT MTU) + 10 bytes
332  * @return
333  */
334 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);
335 
336 /**
337  * @brief MTU is available after the first query has completed. If status is equal to ERROR_CODE_SUCCESS, it returns the real value,
338  * otherwise the default value ATT_DEFAULT_MTU (see bluetooth.h).
339  * @param  con_handle
340  * @param  mtu
341  * @return status ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER                  if no HCI connection for con_handle is found
342  *                BTSTACK_MEMORY_ALLOC_FAILED                               if no GATT client for con_handle could be allocated
343  *                GATT_CLIENT_IN_WRONG_STATE                                if MTU is not exchanged and MTU auto-exchange is disabled
344  *                ERROR_CODE_SUCCESS                                        if query is successfully registered
345  */
346 uint8_t gatt_client_get_mtu(hci_con_handle_t con_handle, uint16_t * mtu);
347 
348 /**
349  * @brief Sets whether a MTU Exchange Request shall be automatically send before the
350  * first attribute read request is send. Default is enabled.
351  * @param enabled
352  */
353 void gatt_client_mtu_enable_auto_negotiation(uint8_t enabled);
354 
355 /**
356  * @brief Sends a MTU Exchange Request, this allows for the client to exchange MTU
357  * when gatt_client_mtu_enable_auto_negotiation is disabled.
358  * @param  callback
359  * @param  con_handle
360  */
361 void gatt_client_send_mtu_negotiation(btstack_packet_handler_t callback, hci_con_handle_t con_handle);
362 
363 /**
364  * @brief Returns 1 if the GATT client is ready to receive a query. It is used with daemon.
365  * @param  con_handle
366  * @return is_ready_status     0 - if no GATT client for con_handle is found, or is not ready, otherwise 1
367  */
368 int gatt_client_is_ready(hci_con_handle_t con_handle);
369 
370 /**
371  * @brief Discovers all primary services.
372  * For each found service a GATT_EVENT_SERVICE_QUERY_RESULT event will be emitted.
373  * The GATT_EVENT_QUERY_COMPLETE event marks the end of discovery.
374  * @param  callback
375  * @param  con_handle
376  * @return status BTSTACK_MEMORY_ALLOC_FAILED, if no GATT client for con_handle is found
377  *                GATT_CLIENT_IN_WRONG_STATE , if GATT client is not ready
378  *                ERROR_CODE_SUCCESS         , if query is successfully registered
379  */
380 uint8_t gatt_client_discover_primary_services(btstack_packet_handler_t callback, hci_con_handle_t con_handle);
381 
382 /**
383  * @brief Discovers all secondary services.
384  * For each found service a GATT_EVENT_SERVICE_QUERY_RESULT event will be emitted.
385  * The GATT_EVENT_QUERY_COMPLETE event marks the end of discovery.
386  * @param  callback
387  * @param  con_handle
388  * @return status BTSTACK_MEMORY_ALLOC_FAILED, if no GATT client for con_handle is found
389  *                GATT_CLIENT_IN_WRONG_STATE , if GATT client is not ready
390  *                ERROR_CODE_SUCCESS         , if query is successfully registered
391  */
392 uint8_t gatt_client_discover_secondary_services(btstack_packet_handler_t callback, hci_con_handle_t con_handle);
393 
394 /**
395  * @brief Discovers a specific primary service given its UUID. This service may exist multiple times.
396  * For each found service a GATT_EVENT_SERVICE_QUERY_RESULT event will be emitted.
397  * The GATT_EVENT_QUERY_COMPLETE event marks the end of discovery.
398  * @param callback
399  * @param con_handle
400  * @param uuid16
401  * @return status BTSTACK_MEMORY_ALLOC_FAILED, if no GATT client for con_handle is found
402  *                GATT_CLIENT_IN_WRONG_STATE , if GATT client is not ready
403  *                ERROR_CODE_SUCCESS         , if query is successfully registered
404  */
405 uint8_t gatt_client_discover_primary_services_by_uuid16(btstack_packet_handler_t callback, hci_con_handle_t con_handle, uint16_t uuid16);
406 
407 /**
408  * @brief Discovers a specific primary service given its UUID. This service may exist multiple times.
409  * For each found service a GATT_EVENT_SERVICE_QUERY_RESULT event will be emitted.
410  * The GATT_EVENT_QUERY_COMPLETE event marks the end of discovery.
411  * @param  callback
412  * @param  con_handle
413  * @param  uuid128
414  * @return status BTSTACK_MEMORY_ALLOC_FAILED, if no GATT client for con_handle is found
415  *                GATT_CLIENT_IN_WRONG_STATE , if GATT client is not ready
416  *                ERROR_CODE_SUCCESS         , if query is successfully registered
417  */
418 uint8_t gatt_client_discover_primary_services_by_uuid128(btstack_packet_handler_t callback, hci_con_handle_t con_handle, const uint8_t * uuid128);
419 
420 /**
421  * @brief Finds included services within the specified service.
422  * For each found included service a GATT_EVENT_INCLUDED_SERVICE_QUERY_RESULT event will be emitted.
423  * The GATT_EVENT_QUERY_COMPLETE event marks the end of discovery.
424  * Information about included service type (primary/secondary) can be retrieved either by sending
425  * an ATT find information request for the returned start group handle
426  * (returning the handle and the UUID for primary or secondary service) or by comparing the service
427  * to the list of all primary services.
428  * @param  callback
429  * @param  con_handle
430  * @param  service
431  * @return status BTSTACK_MEMORY_ALLOC_FAILED, if no GATT client for con_handle is found
432  *                GATT_CLIENT_IN_WRONG_STATE , if GATT client is not ready
433  *                ERROR_CODE_SUCCESS         , if query is successfully registered
434  */
435 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);
436 
437 /**
438  * @brief Discovers all characteristics within the specified service.
439  * For each found characteristic a GATT_EVENT_CHARACTERISTIC_QUERY_RESULT event will be emited.
440  * The GATT_EVENT_QUERY_COMPLETE event marks the end of discovery.
441  * @param  callback
442  * @param  con_handle
443  * @param  service
444  * @return status BTSTACK_MEMORY_ALLOC_FAILED, if no GATT client for con_handle is found
445  *                GATT_CLIENT_IN_WRONG_STATE , if GATT client is not ready
446  *                ERROR_CODE_SUCCESS         , if query is successfully registered
447  */
448 uint8_t gatt_client_discover_characteristics_for_service(btstack_packet_handler_t callback, hci_con_handle_t con_handle, gatt_client_service_t * service);
449 
450 /**
451  * @brief The following four functions are used to discover all characteristics within
452  * the specified service or handle range, and return those that match the given UUID.
453  *
454  * For each found characteristic a GATT_EVENT_CHARACTERISTIC_QUERY_RESULT event will emitted.
455  * The GATT_EVENT_QUERY_COMPLETE event marks the end of discovery.
456  * @param  callback
457  * @param  con_handle
458  * @param  start_handle
459  * @param  end_handle
460  * @param  uuid16
461  * @return status BTSTACK_MEMORY_ALLOC_FAILED, if no GATT client for con_handle is found
462  *                GATT_CLIENT_IN_WRONG_STATE , if GATT client is not ready
463  *                ERROR_CODE_SUCCESS         , if query is successfully registered
464  */
465 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);
466 
467 /**
468  * @brief The following four functions are used to discover all characteristics within the
469  * specified service or handle range, and return those that match the given UUID.
470  * For each found characteristic a GATT_EVENT_CHARACTERISTIC_QUERY_RESULT event will emitted.
471  * The GATT_EVENT_QUERY_COMPLETE event marks the end of discovery.
472  * @param  callback
473  * @param  con_handle
474  * @param  start_handle
475  * @param  end_handle
476  * @param  uuid128
477  * @return status BTSTACK_MEMORY_ALLOC_FAILED, if no GATT client for con_handle is found
478  *                GATT_CLIENT_IN_WRONG_STATE , if GATT client is not ready
479  *                ERROR_CODE_SUCCESS         , if query is successfully registered
480  */
481 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);
482 
483 /**
484  * @brief The following four functions are used to discover all characteristics within the
485  * specified service or handle range, and return those that match the given UUID.
486  * For each found characteristic a GATT_EVENT_CHARACTERISTIC_QUERY_RESULT event will emitted.
487  * The GATT_EVENT_QUERY_COMPLETE event marks the end of discovery.
488  * @param  callback
489  * @param  con_handle
490  * @param  service
491  * @param  uuid16
492  * @return status BTSTACK_MEMORY_ALLOC_FAILED, if no GATT client for con_handle is found
493  *                GATT_CLIENT_IN_WRONG_STATE , if GATT client is not ready
494  *                ERROR_CODE_SUCCESS         , if query is successfully registered
495  */
496 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);
497 
498 /**
499  * @brief The following four functions are used to discover all characteristics within the
500  * specified service or handle range, and return those that match the given UUID.
501  * For each found characteristic a GATT_EVENT_CHARACTERISTIC_QUERY_RESULT event will emitted.
502  * The GATT_EVENT_QUERY_COMPLETE event marks the end of discovery.
503  * @param  callback
504  * @param  con_handle
505  * @param  service
506  * @param  uuid128
507  * @return status BTSTACK_MEMORY_ALLOC_FAILED, if no GATT client for con_handle is found
508  *                GATT_CLIENT_IN_WRONG_STATE , if GATT client is not ready
509  *                ERROR_CODE_SUCCESS         , if query is successfully registered
510  */
511 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);
512 
513 /**
514  * @brief Discovers attribute handle and UUID of a characteristic descriptor within the specified characteristic.
515  * For each found descriptor a GATT_EVENT_ALL_CHARACTERISTIC_DESCRIPTORS_QUERY_RESULT event will be emitted.
516  *
517  * The GATT_EVENT_QUERY_COMPLETE event marks the end of discovery.
518  * @param  callback
519  * @param  con_handle
520  * @param  characteristic
521  * @return status BTSTACK_MEMORY_ALLOC_FAILED, if no GATT client for con_handle is found
522  *                GATT_CLIENT_IN_WRONG_STATE , if GATT client is not ready
523  *                ERROR_CODE_SUCCESS         , if query is successfully registered
524  */
525 uint8_t gatt_client_discover_characteristic_descriptors(btstack_packet_handler_t callback, hci_con_handle_t con_handle, gatt_client_characteristic_t * characteristic);
526 
527 /**
528  * @brief Reads the characteristic value using the characteristic's value handle.
529  * If the characteristic value is found a GATT_EVENT_CHARACTERISTIC_VALUE_QUERY_RESULT event will be emitted.
530  * The GATT_EVENT_QUERY_COMPLETE event marks the end of read.
531  * @param  callback
532  * @param  con_handle
533  * @param  characteristic
534  * @return status BTSTACK_MEMORY_ALLOC_FAILED, if no GATT client for con_handle is found
535  *                GATT_CLIENT_IN_WRONG_STATE , if GATT client is not ready
536  *                ERROR_CODE_SUCCESS         , if query is successfully registered
537  */
538 uint8_t gatt_client_read_value_of_characteristic(btstack_packet_handler_t callback, hci_con_handle_t con_handle, gatt_client_characteristic_t * characteristic);
539 
540 /**
541  * @brief Reads the characteristic value using the characteristic's value handle.
542  * If the characteristic value is found a GATT_EVENT_CHARACTERISTIC_VALUE_QUERY_RESULT event will be emitted.
543  * The GATT_EVENT_QUERY_COMPLETE event marks the end of read.
544  * @param  callback
545  * @param  con_handle
546  * @param  value_handle
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_read_value_of_characteristic_using_value_handle(btstack_packet_handler_t callback, hci_con_handle_t con_handle, uint16_t value_handle);
552 
553 /**
554  * @brief Reads the characteric value of all characteristics with the uuid.
555  * For each characteristic value found a GATT_EVENT_CHARACTERISTIC_VALUE_QUERY_RESULT event will be emitted.
556  * The GATT_EVENT_QUERY_COMPLETE event marks the end of read.
557  * @param  callback
558  * @param  con_handle
559  * @param  start_handle
560  * @param  end_handle
561  * @param  uuid16
562  * @return status BTSTACK_MEMORY_ALLOC_FAILED, if no GATT client for con_handle is found
563  *                GATT_CLIENT_IN_WRONG_STATE , if GATT client is not ready
564  *                ERROR_CODE_SUCCESS         , if query is successfully registered
565  */
566 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);
567 
568 /**
569  * @brief Reads the characteric value of all characteristics with the uuid.
570  * For each characteristic value found a GATT_EVENT_CHARACTERISTIC_VALUE_QUERY_RESULT event will be emitted.
571  * The GATT_EVENT_QUERY_COMPLETE event marks the end of read.
572  * @param  callback
573  * @param  con_handle
574  * @param  start_handle
575  * @param  end_handle
576  * @param  uuid128
577  * @return status BTSTACK_MEMORY_ALLOC_FAILED, if no GATT client for con_handle is found
578  *                GATT_CLIENT_IN_WRONG_STATE , if GATT client is not ready
579  *                ERROR_CODE_SUCCESS         , if query is successfully registered
580  */
581 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);
582 
583 /**
584  * @brief Reads the long characteristic value using the characteristic's value handle.
585  * The value will be returned in several blobs.
586  * For each blob, a GATT_EVENT_LONG_CHARACTERISTIC_VALUE_QUERY_RESULT event with updated value offset will be emitted.
587  * The GATT_EVENT_QUERY_COMPLETE event marks the end of read.
588  * @param  callback
589  * @param  con_handle
590  * @param  characteristic
591  * @return status BTSTACK_MEMORY_ALLOC_FAILED, if no GATT client for con_handle is found
592  *                GATT_CLIENT_IN_WRONG_STATE , if GATT client is not ready
593  *                ERROR_CODE_SUCCESS         , if query is successfully registered
594  */
595 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);
596 
597 /**
598  * @brief Reads the long characteristic value using the characteristic's value handle.
599  * The value will be returned in several blobs.
600  * For each blob, a GATT_EVENT_LONG_CHARACTERISTIC_VALUE_QUERY_RESULT event with updated value offset will be emitted.
601  * The GATT_EVENT_QUERY_COMPLETE event marks the end of read.
602  * @param  callback
603  * @param  con_handle
604  * @param  value_handle
605  * @return status BTSTACK_MEMORY_ALLOC_FAILED, if no GATT client for con_handle is found
606  *                GATT_CLIENT_IN_WRONG_STATE , if GATT client is not ready
607  *                ERROR_CODE_SUCCESS         , if query is successfully registered
608  */
609 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);
610 
611 /**
612  * @brief Reads the long characteristic value using the characteristic's value handle.
613  * The value will be returned in several blobs.
614  * For each blob, a GATT_EVENT_LONG_CHARACTERISTIC_VALUE_QUERY_RESULT event with updated value offset will be emitted.
615  * The GATT_EVENT_QUERY_COMPLETE event marks the end of read.
616  * @param  callback
617  * @param  con_handle
618  * @param  value_handle
619  * @param  offset
620  * @return status BTSTACK_MEMORY_ALLOC_FAILED, if no GATT client for con_handle is found
621  *                GATT_CLIENT_IN_WRONG_STATE , if GATT client is not ready
622  *                ERROR_CODE_SUCCESS         , if query is successfully registered
623  */
624 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);
625 
626 /*
627  * @brief Read multiple characteristic values.
628  * The all results are emitted via single GATT_EVENT_CHARACTERISTIC_VALUE_QUERY_RESULT event,
629  * followed by the GATT_EVENT_QUERY_COMPLETE event, which marks the end of read.
630  * @param  callback
631  * @param  con_handle
632  * @param  num_value_handles
633  * @param  value_handles list of handles
634  * @return status BTSTACK_MEMORY_ALLOC_FAILED, if no GATT client for con_handle is found
635  *                GATT_CLIENT_IN_WRONG_STATE , if GATT client is not ready
636  *                ERROR_CODE_SUCCESS         , if query is successfully registered
637  */
638 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);
639 
640 /*
641  * @brief Read multiple varaible characteristic values. Only supported over LE Enhanced Bearer
642  * The all results are emitted via single GATT_EVENT_CHARACTERISTIC_VALUE_QUERY_RESULT event,
643  * followed by the GATT_EVENT_QUERY_COMPLETE event, which marks the end of read.
644  * @param  callback
645  * @param  con_handle
646  * @param  num_value_handles
647  * @param  value_handles list of handles
648  * @return status BTSTACK_MEMORY_ALLOC_FAILED, if no GATT client for con_handle is found
649  *                GATT_CLIENT_IN_WRONG_STATE , if GATT client is not ready
650  *                ERROR_CODE_SUCCESS         , if query is successfully registered
651  */
652 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);
653 
654 /**
655  * @brief Writes the characteristic value using the characteristic's value handle without
656  * an acknowledgment that the write was successfully performed.
657  * @param  con_handle
658  * @param  value_handle
659  * @param  value_length
660  * @param  value is copied on success and does not need to be retained
661  * @return status BTSTACK_MEMORY_ALLOC_FAILED, if no GATT client for con_handle is found
662  *                GATT_CLIENT_IN_WRONG_STATE , if GATT client is not ready
663  *                BTSTACK_ACL_BUFFERS_FULL   , if L2CAP cannot send, there are no free ACL slots
664  *                ERROR_CODE_SUCCESS         , if query is successfully registered
665  */
666 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);
667 
668 /**
669  * @brief Writes the authenticated characteristic value using the characteristic's value handle
670  * without an acknowledgment that the write was successfully performed.
671  * @note GATT_EVENT_QUERY_COMPLETE is emitted with ATT_ERROR_SUCCESS for success,
672  * or ATT_ERROR_BONDING_INFORMATION_MISSING if there is no bonding information stored.
673  * @param  callback
674  * @param  con_handle
675  * @param  value_handle
676  * @param  message_len
677  * @param  message is not copied, make sure memory is accessible until write is done
678  * @return status ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER                  if no HCI connection for con_handle is found
679  *                BTSTACK_MEMORY_ALLOC_FAILED                               if no GATT client for con_handle could be allocated
680  *                GATT_CLIENT_IN_WRONG_STATE                                if GATT client is not ready
681  *                ERROR_CODE_SUCCESS                                        if query is successfully registered
682  */
683 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);
684 
685 /**
686  * @brief Writes the characteristic value using the characteristic's value handle.
687  * The GATT_EVENT_QUERY_COMPLETE event marks the end of write.
688  * The write is successfully performed, if the event's att_status field is set to
689  * ATT_ERROR_SUCCESS (see bluetooth.h for ATT_ERROR codes).
690  * @param  callback
691  * @param  con_handle
692  * @param  value_handle
693  * @param  value_length
694  * @param  value is not copied, make sure memory is accessible until write is done, i.e. GATT_EVENT_QUERY_COMPLETE is received
695  * @return status ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER                  if no HCI connection for con_handle is found
696  *                BTSTACK_MEMORY_ALLOC_FAILED                               if no GATT client for con_handle could be allocated
697  *                GATT_CLIENT_IN_WRONG_STATE                                if GATT client is not ready
698  *                ERROR_CODE_SUCCESS                                        if query is successfully registered
699  */
700 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);
701 
702 /**
703  * @brief Writes the characteristic value using the characteristic's value handle.
704  * The GATT_EVENT_QUERY_COMPLETE event marks the end of write.
705  * 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).
706  * @param  callback
707  * @param  con_handle
708  * @param  value_handle
709  * @param  value_length
710  * @param  value is not copied, make sure memory is accessible until write is done, i.e. GATT_EVENT_QUERY_COMPLETE is received
711  * @return status ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER                  if no HCI connection for con_handle is found
712  *                BTSTACK_MEMORY_ALLOC_FAILED                               if no GATT client for con_handle could be allocated
713  *                GATT_CLIENT_IN_WRONG_STATE                                if GATT client is not ready
714  *                ERROR_CODE_SUCCESS                                        if query is successfully registered
715  */
716 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);
717 
718 /**
719  * @brief Writes the characteristic value using the characteristic's value handle.
720  * The GATT_EVENT_QUERY_COMPLETE event marks the end of write.
721  * 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).
722  * @param  callback
723  * @param  con_handle
724  * @param  value_handle
725  * @param  offset of value
726  * @param  value_length
727  * @param  value is not copied, make sure memory is accessible until write is done, i.e. GATT_EVENT_QUERY_COMPLETE is received
728  * @return status ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER                  if no HCI connection for con_handle is found
729  *                BTSTACK_MEMORY_ALLOC_FAILED                               if no GATT client for con_handle could be allocated
730  *                GATT_CLIENT_IN_WRONG_STATE                                if GATT client is not ready
731  *                ERROR_CODE_SUCCESS                                        if query is successfully registered
732  */
733 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);
734 
735 /**
736  * @brief Writes of the long characteristic value using the characteristic's value handle.
737  * It uses server response to validate that the write was correctly received.
738  * The GATT_EVENT_QUERY_COMPLETE EVENT marks the end of write.
739  * 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).
740  * @param  callback
741  * @param  con_handle
742  * @param  value_handle
743  * @param  value_length
744  * @param  value is not copied, make sure memory is accessible until write is done, i.e. GATT_EVENT_QUERY_COMPLETE is received
745  * @return status ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER                  if no HCI connection for con_handle is found
746  *                BTSTACK_MEMORY_ALLOC_FAILED                               if no GATT client for con_handle could be allocated
747  *                GATT_CLIENT_IN_WRONG_STATE                                if GATT client is not ready
748  *                ERROR_CODE_SUCCESS                                        if query is successfully registered
749  */
750 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);
751 
752 /**
753  * @brief Reads the characteristic descriptor using its handle.
754  * If the characteristic descriptor is found, a GATT_EVENT_CHARACTERISTIC_DESCRIPTOR_QUERY_RESULT event will be emitted.
755  * The GATT_EVENT_QUERY_COMPLETE event marks the end of read.
756  * @param  callback
757  * @param  con_handle
758  * @param  descriptor
759  * @return status ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER                  if no HCI connection for con_handle is found
760  *                BTSTACK_MEMORY_ALLOC_FAILED                               if no GATT client for con_handle could be allocated
761  *                GATT_CLIENT_IN_WRONG_STATE                                if GATT client is not ready
762  *                ERROR_CODE_SUCCESS                                        if query is successfully registered
763  */
764 uint8_t gatt_client_read_characteristic_descriptor(btstack_packet_handler_t callback, hci_con_handle_t con_handle, gatt_client_characteristic_descriptor_t * descriptor);
765 
766 /**
767  * @brief Reads the characteristic descriptor using its handle.
768  * If the characteristic descriptor is found, a GATT_EVENT_CHARACTERISTIC_DESCRIPTOR_QUERY_RESULT event will be emitted.
769  * The GATT_EVENT_QUERY_COMPLETE event marks the end of read.
770  * @param  callback
771  * @param  con_handle
772  * @param  descriptor
773  * @return status ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER                  if no HCI connection for con_handle is found
774  *                BTSTACK_MEMORY_ALLOC_FAILED                               if no GATT client for con_handle could be allocated
775  *                GATT_CLIENT_IN_WRONG_STATE                                if GATT client is not ready
776  *                ERROR_CODE_SUCCESS                                        if query is successfully registered
777  */
778 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);
779 
780 /**
781  * @brief Reads the long characteristic descriptor using its handle. It will be returned in several blobs.
782  * For each blob, a GATT_EVENT_CHARACTERISTIC_DESCRIPTOR_QUERY_RESULT event will be emitted.
783  * The GATT_EVENT_QUERY_COMPLETE event marks the end of read.
784  * @param  callback
785  * @param  con_handle
786  * @param  descriptor
787  * @return status ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER                  if no HCI connection for con_handle is found
788  *                BTSTACK_MEMORY_ALLOC_FAILED                               if no GATT client for con_handle could be allocated
789  *                GATT_CLIENT_IN_WRONG_STATE                                if GATT client is not ready
790  *                ERROR_CODE_SUCCESS                                        if query is successfully registered
791  */
792 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);
793 
794 /**
795  * @brief Reads the long characteristic descriptor using its handle. It will be returned in several blobs.
796  * For each blob, a GATT_EVENT_CHARACTERISTIC_DESCRIPTOR_QUERY_RESULT event will be emitted.
797  * The GATT_EVENT_QUERY_COMPLETE event marks the end of read.
798  * @param  callback
799  * @param  con_handle
800  * @param  descriptor_handle
801  * @return status ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER                  if no HCI connection for con_handle is found
802  *                BTSTACK_MEMORY_ALLOC_FAILED                               if no GATT client for con_handle could be allocated
803  *                GATT_CLIENT_IN_WRONG_STATE                                if GATT client is not ready
804  *                ERROR_CODE_SUCCESS                                        if query is successfully registered
805  */
806 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);
807 
808 /**
809  * @brief Reads the long characteristic descriptor using its handle. It will be returned in several blobs.
810  * For each blob, a GATT_EVENT_CHARACTERISTIC_DESCRIPTOR_QUERY_RESULT event will be emitted.
811  * The GATT_EVENT_QUERY_COMPLETE event marks the end of read.
812  * @param  callback
813  * @param  con_handle
814  * @param  descriptor_handle
815  * @param  offset
816  * @return status ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER                  if no HCI connection for con_handle is found
817  *                BTSTACK_MEMORY_ALLOC_FAILED                               if no GATT client for con_handle could be allocated
818  *                GATT_CLIENT_IN_WRONG_STATE                                if GATT client is not ready
819  *                ERROR_CODE_SUCCESS                                        if query is successfully registered
820  */
821 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);
822 
823 /**
824  * @brief Writes the characteristic descriptor using its handle.
825  * The GATT_EVENT_QUERY_COMPLETE event marks the end of write.
826  * 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).
827  * @param  callback
828  * @param  con_handle
829  * @param  descriptor
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_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);
838 
839 /**
840  * @brief Writes the characteristic descriptor using its handle.
841  * The GATT_EVENT_QUERY_COMPLETE event marks the end of write.
842  * 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).
843  * @param  callback
844  * @param  con_handle
845  * @param  descriptor_handle
846  * @param  value_length
847  * @param  value is not copied, make sure memory is accessible until write is done, i.e. GATT_EVENT_QUERY_COMPLETE is received
848  * @return status ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER                  if no HCI connection for con_handle is found
849  *                BTSTACK_MEMORY_ALLOC_FAILED                               if no GATT client for con_handle could be allocated
850  *                GATT_CLIENT_IN_WRONG_STATE                                if GATT client is not ready
851  *                ERROR_CODE_SUCCESS                                        if query is successfully registered
852  */
853 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);
854 
855 /**
856  * @brief Writes the characteristic descriptor using its handle.
857  * The GATT_EVENT_QUERY_COMPLETE event marks the end of write.
858  * 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).
859  * @param  callback
860  * @param  con_handle
861  * @param  descriptor
862  * @param  value_length
863  * @param  value is not copied, make sure memory is accessible until write is done, i.e. GATT_EVENT_QUERY_COMPLETE is received
864  * @return status ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER                  if no HCI connection for con_handle is found
865  *                BTSTACK_MEMORY_ALLOC_FAILED                               if no GATT client for con_handle could be allocated
866  *                GATT_CLIENT_IN_WRONG_STATE                                if GATT client is not ready
867  *                ERROR_CODE_SUCCESS                                        if query is successfully registered
868  */
869 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);
870 
871 /**
872  * @brief Writes the characteristic descriptor using its handle.
873  * The GATT_EVENT_QUERY_COMPLETE event marks the end of write.
874  * 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).
875  * @param  callback
876  * @param  con_handle
877  * @param  descriptor_handle
878  * @param  value_length
879  * @param  value is not copied, make sure memory is accessible until write is done, i.e. GATT_EVENT_QUERY_COMPLETE is received
880  * @return status ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER                  if no HCI connection for con_handle is found
881  *                BTSTACK_MEMORY_ALLOC_FAILED                               if no GATT client for con_handle could be allocated
882  *                GATT_CLIENT_IN_WRONG_STATE                                if GATT client is not ready
883  *                ERROR_CODE_SUCCESS                                        if query is successfully registered
884  */
885 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);
886 
887 /**
888  * @brief Writes the characteristic descriptor using its handle.
889  * The GATT_EVENT_QUERY_COMPLETE event marks the end of write.
890  * 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).
891  * @param  callback
892  * @param  con_handle
893  * @param  descriptor_handle
894  * @param  offset of value
895  * @param  value_length
896  * @param  value is not copied, make sure memory is accessible until write is done, i.e. GATT_EVENT_QUERY_COMPLETE is received
897  * @return status ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER                  if no HCI connection for con_handle is found
898  *                BTSTACK_MEMORY_ALLOC_FAILED                               if no GATT client for con_handle could be allocated
899  *                GATT_CLIENT_IN_WRONG_STATE                                if GATT client is not ready
900  *                ERROR_CODE_SUCCESS                                        if query is successfully registered
901  */
902 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);
903 
904 /**
905  * @brief Writes the client characteristic configuration of the specified characteristic.
906  * It is used to subscribe for notifications or indications of the characteristic value.
907  * For notifications or indications specify: GATT_CLIENT_CHARACTERISTICS_CONFIGURATION_NOTIFICATION
908  * resp. GATT_CLIENT_CHARACTERISTICS_CONFIGURATION_INDICATION as configuration value.
909  * The GATT_EVENT_QUERY_COMPLETE event marks the end of write.
910  * 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).
911  * @param  callback
912  * @param  con_handle
913  * @param  characteristic
914  * @param  configuration                                                    GATT_CLIENT_CHARACTERISTICS_CONFIGURATION_NOTIFICATION, GATT_CLIENT_CHARACTERISTICS_CONFIGURATION_INDICATION
915  * @return status ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER                  if no HCI connection for con_handle is found
916  *                BTSTACK_MEMORY_ALLOC_FAILED                               if no GATT client for con_handle could be allocated
917  *                GATT_CLIENT_IN_WRONG_STATE                                if GATT client is not ready
918  *                GATT_CLIENT_CHARACTERISTIC_NOTIFICATION_NOT_SUPPORTED     if configuring notification, but characteristic has no notification property set
919  *                GATT_CLIENT_CHARACTERISTIC_INDICATION_NOT_SUPPORTED       if configuring indication, but characteristic has no indication property set
920  *                ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE         if configuration is invalid
921  *                ERROR_CODE_SUCCESS                                        if query is successfully registered
922  */
923 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);
924 
925 /**
926  * @brief Register for notifications and indications of a characteristic enabled by
927  * the gatt_client_write_client_characteristic_configuration function.
928  * @param notification struct used to store registration
929  * @param callback
930  * @param con_handle or GATT_CLIENT_ANY_CONNECTION to receive updates from all connected devices
931  * @param characteristic or NULL to receive updates for all characteristics
932  */
933 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);
934 
935 /**
936  * @brief Stop listening to characteristic value updates registered with
937  * the gatt_client_listen_for_characteristic_value_updates function.
938  * @param notification struct used in gatt_client_listen_for_characteristic_value_updates
939  */
940 void gatt_client_stop_listening_for_characteristic_value_updates(gatt_client_notification_t * notification);
941 
942 /**
943  * @brief Transactional write. It can be called as many times as it is needed to write the characteristics within the same transaction.
944  * Call the gatt_client_execute_write function to commit the transaction.
945  * @param  callback
946  * @param  con_handle
947  * @param  attribute_handle
948  * @param  offset of value
949  * @param  value_length
950  * @param  value is not copied, make sure memory is accessible until write is done, i.e. GATT_EVENT_QUERY_COMPLETE is received
951  */
952 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);
953 
954 /**
955  * @brief Commit transactional write. GATT_EVENT_QUERY_COMPLETE is received.
956  * @param  callback
957  * @param  con_handle
958  * @return status
959  */
960 uint8_t gatt_client_execute_write(btstack_packet_handler_t callback, hci_con_handle_t con_handle);
961 
962 /**
963  * @brief Abort transactional write. GATT_EVENT_QUERY_COMPLETE is received.
964  * @param  callback
965  * @param  con_handle
966  * @return status
967  */
968 uint8_t gatt_client_cancel_write(btstack_packet_handler_t callback, hci_con_handle_t con_handle);
969 
970 /**
971  * @brief Request callback when regular gatt query can be sent
972  * @note callback might happen during call to this function
973  * @param callback_registration to point to callback function and context information
974  * @param con_handle
975  * @return ERROR_CODE_SUCCESS if ok, ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER if handle unknown, and ERROR_CODE_COMMAND_DISALLOWED if callback already registered
976  */
977 uint8_t gatt_client_request_to_send_gatt_query(btstack_context_callback_registration_t * callback_registration, hci_con_handle_t con_handle);
978 
979 /**
980  * @brief Request callback when writing characteristic value without response is possible
981  * @note callback might happen during call to this function
982  * @param callback_registration to point to callback function and context information
983  * @param con_handle
984  * @return ERROR_CODE_SUCCESS if ok, ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER if handle unknown, and ERROR_CODE_COMMAND_DISALLOWED if callback already registered
985  */
986 uint8_t gatt_client_request_to_write_without_response(btstack_context_callback_registration_t * callback_registration, hci_con_handle_t con_handle);
987 
988 
989 // the following functions are marked as deprecated and will be removed eventually
990 /**
991  * @brief Requests GATT_EVENT_CAN_WRITE_WITHOUT_RESPONSE that guarantees
992  * a single successful gatt_client_write_value_of_characteristic_without_response call.
993  * @deprecated please use gatt_client_request_to_write_without_response instead
994  * @param  callback
995  * @param  con_handle
996  * @return status
997  */
998 uint8_t gatt_client_request_can_write_without_response_event(btstack_packet_handler_t callback, hci_con_handle_t con_handle);
999 
1000 
1001 /* API_END */
1002 
1003 // used by generated btstack_event.c
1004 
1005 void gatt_client_deserialize_service(const uint8_t *packet, int offset, gatt_client_service_t * service);
1006 void gatt_client_deserialize_characteristic(const uint8_t * packet, int offset, gatt_client_characteristic_t * characteristic);
1007 void gatt_client_deserialize_characteristic_descriptor(const uint8_t * packet, int offset, gatt_client_characteristic_descriptor_t * descriptor);
1008 
1009 #ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
1010 void gatt_client_att_packet_handler_fuzz(uint8_t packet_type, uint16_t handle, uint8_t *packet, uint16_t size);
1011 uint8_t gatt_client_get_client(hci_con_handle_t con_handle, gatt_client_t ** gatt_client);
1012 #endif
1013 
1014 #if defined __cplusplus
1015 }
1016 #endif
1017 
1018 #endif
1019