xref: /btstack/src/ble/gatt_client.c (revision 5cf1669fe0f2ef3981ac99d7386adf79b7ff9acf)
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 MATTHIAS
24  * RINGWALD 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 #define BTSTACK_FILE__ "gatt_client.c"
39 
40 #include <stdint.h>
41 #include <string.h>
42 
43 #include "btstack_config.h"
44 
45 #include "att_dispatch.h"
46 #include "ad_parser.h"
47 #include "ble/att_db.h"
48 #include "ble/core.h"
49 #include "ble/gatt_client.h"
50 #include "ble/le_device_db.h"
51 #include "ble/sm.h"
52 #include "btstack_debug.h"
53 #include "btstack_event.h"
54 #include "btstack_memory.h"
55 #include "btstack_run_loop.h"
56 #include "btstack_util.h"
57 #include "classic/sdp_util.h"
58 #include "hci.h"
59 #include "hci_cmd.h"
60 #include "hci_dump.h"
61 #include "l2cap.h"
62 
63 static btstack_linked_list_t gatt_client_connections;
64 static btstack_linked_list_t gatt_client_value_listeners;
65 static btstack_packet_callback_registration_t hci_event_callback_registration;
66 
67 #if defined(ENABLE_GATT_CLIENT_PAIRING) || defined (ENABLE_LE_SIGNED_WRITE)
68 static btstack_packet_callback_registration_t sm_event_callback_registration;
69 #endif
70 
71 static uint8_t mtu_exchange_enabled;
72 
73 static void gatt_client_att_packet_handler(uint8_t packet_type, uint16_t handle, uint8_t *packet, uint16_t size);
74 static void gatt_client_event_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
75 static void gatt_client_report_error_if_pending(gatt_client_t *gatt_client, uint8_t att_error_code);
76 
77 #ifdef ENABLE_LE_SIGNED_WRITE
78 static void att_signed_write_handle_cmac_result(uint8_t hash[8]);
79 #endif
80 
81 static uint16_t gatt_client_mtu(gatt_client_t *gatt_client){
82     if (gatt_client->mtu > l2cap_max_le_mtu()){
83         log_error("Remote MTU is not initialized");
84         return l2cap_max_le_mtu();
85     }
86     return gatt_client->mtu;
87 }
88 
89 void gatt_client_init(void){
90     gatt_client_connections = NULL;
91     mtu_exchange_enabled = 1;
92 
93     // regsister for HCI Events
94     hci_event_callback_registration.callback = &gatt_client_event_packet_handler;
95     hci_add_event_handler(&hci_event_callback_registration);
96 
97 #if defined(ENABLE_GATT_CLIENT_PAIRING) || defined (ENABLE_LE_SIGNED_WRITE)
98     // register for SM Events
99     sm_event_callback_registration.callback = &gatt_client_event_packet_handler;
100     sm_add_event_handler(&sm_event_callback_registration);
101 #endif
102 
103     // and ATT Client PDUs
104     att_dispatch_register_client(gatt_client_att_packet_handler);
105 }
106 
107 static gatt_client_t * gatt_client_for_timer(btstack_timer_source_t * ts){
108     btstack_linked_list_iterator_t it;
109     btstack_linked_list_iterator_init(&it, &gatt_client_connections);
110     while (btstack_linked_list_iterator_has_next(&it)){
111         gatt_client_t * gatt_client = (gatt_client_t *) btstack_linked_list_iterator_next(&it);
112         if (&gatt_client->gc_timeout == ts) {
113             return gatt_client;
114         }
115     }
116     return NULL;
117 }
118 
119 static void gatt_client_timeout_handler(btstack_timer_source_t * timer){
120     gatt_client_t * gatt_client = gatt_client_for_timer(timer);
121     if (gatt_client == NULL) return;
122     log_info("GATT client timeout handle, handle 0x%02x", gatt_client->con_handle);
123     gatt_client_report_error_if_pending(gatt_client, ATT_ERROR_TIMEOUT);
124 }
125 
126 static void gatt_client_timeout_start(gatt_client_t * gatt_client){
127     log_info("GATT client timeout start, handle 0x%02x", gatt_client->con_handle);
128     btstack_run_loop_remove_timer(&gatt_client->gc_timeout);
129     btstack_run_loop_set_timer_handler(&gatt_client->gc_timeout, gatt_client_timeout_handler);
130     btstack_run_loop_set_timer(&gatt_client->gc_timeout, 30000); // 30 seconds sm timeout
131     btstack_run_loop_add_timer(&gatt_client->gc_timeout);
132 }
133 
134 static void gatt_client_timeout_stop(gatt_client_t * gatt_client){
135     log_info("GATT client timeout stop, handle 0x%02x", gatt_client->con_handle);
136     btstack_run_loop_remove_timer(&gatt_client->gc_timeout);
137 }
138 
139 static gatt_client_t * gatt_client_get_context_for_handle(uint16_t handle){
140     btstack_linked_item_t *it;
141     for (it = (btstack_linked_item_t *) gatt_client_connections; it != NULL; it = it->next){
142         gatt_client_t * gatt_client = (gatt_client_t *) it;
143         if (gatt_client->con_handle == handle){
144             return gatt_client;
145         }
146     }
147     return NULL;
148 }
149 
150 
151 // @returns gatt_client context
152 // returns existing one, or tries to setup new one
153 static gatt_client_t * gatt_client_provide_context_for_handle(hci_con_handle_t con_handle){
154     gatt_client_t * gatt_client = gatt_client_get_context_for_handle(con_handle);
155     if (gatt_client) return gatt_client;
156 
157     // bail if no such hci connection
158     if (!hci_connection_for_handle(con_handle)){
159         log_error("No connection for handle 0x%04x", con_handle);
160         return NULL;
161     }
162     gatt_client = btstack_memory_gatt_client_get();
163     if (!gatt_client) return NULL;
164     // init state
165     gatt_client->con_handle = con_handle;
166     gatt_client->mtu = ATT_DEFAULT_MTU;
167     if (mtu_exchange_enabled){
168         gatt_client->mtu_state = SEND_MTU_EXCHANGE;
169     } else {
170         gatt_client->mtu_state = MTU_AUTO_EXCHANGE_DISABLED;
171     }
172     gatt_client->gatt_client_state = P_READY;
173     btstack_linked_list_add(&gatt_client_connections, (btstack_linked_item_t*)gatt_client);
174     return gatt_client;
175 }
176 
177 static gatt_client_t * gatt_client_provide_context_for_handle_and_start_timer(hci_con_handle_t con_handle){
178     gatt_client_t * gatt_client = gatt_client_provide_context_for_handle(con_handle);
179     if (gatt_client == NULL) return NULL;
180     gatt_client_timeout_start(gatt_client);
181     return gatt_client;
182 }
183 
184 static int is_ready(gatt_client_t * gatt_client){
185     return gatt_client->gatt_client_state == P_READY;
186 }
187 
188 int gatt_client_is_ready(hci_con_handle_t con_handle){
189     gatt_client_t * gatt_client = gatt_client_provide_context_for_handle(con_handle);
190     if (gatt_client == NULL) return 0;
191     return is_ready(gatt_client);
192 }
193 
194 void gatt_client_mtu_enable_auto_negotiation(uint8_t enabled){
195     mtu_exchange_enabled = enabled;
196 }
197 
198 uint8_t gatt_client_get_mtu(hci_con_handle_t con_handle, uint16_t * mtu){
199     gatt_client_t * gatt_client = gatt_client_provide_context_for_handle(con_handle);
200     if (gatt_client == NULL) return BTSTACK_MEMORY_ALLOC_FAILED;
201 
202     if ((gatt_client->mtu_state == MTU_EXCHANGED) || (gatt_client->mtu_state == MTU_AUTO_EXCHANGE_DISABLED)){
203         *mtu = gatt_client->mtu;
204         return ERROR_CODE_SUCCESS;
205     }
206     *mtu = ATT_DEFAULT_MTU;
207     return GATT_CLIENT_IN_WRONG_STATE;
208 }
209 
210 // precondition: can_send_packet_now == TRUE
211 static uint8_t att_confirmation(uint16_t con_handle){
212     l2cap_reserve_packet_buffer();
213     uint8_t * request = l2cap_get_outgoing_buffer();
214     request[0] = ATT_HANDLE_VALUE_CONFIRMATION;
215 
216     return l2cap_send_prepared_connectionless(con_handle, L2CAP_CID_ATTRIBUTE_PROTOCOL, 1);
217 }
218 
219 // precondition: can_send_packet_now == TRUE
220 static uint8_t att_find_information_request(uint16_t request_type, uint16_t con_handle, uint16_t start_handle, uint16_t end_handle){
221     l2cap_reserve_packet_buffer();
222     uint8_t * request = l2cap_get_outgoing_buffer();
223     request[0] = request_type;
224     little_endian_store_16(request, 1, start_handle);
225     little_endian_store_16(request, 3, end_handle);
226 
227     return l2cap_send_prepared_connectionless(con_handle, L2CAP_CID_ATTRIBUTE_PROTOCOL, 5);
228 }
229 
230 // precondition: can_send_packet_now == TRUE
231 static uint8_t att_find_by_type_value_request(uint16_t request_type, uint16_t attribute_group_type, uint16_t con_handle, uint16_t start_handle, uint16_t end_handle, uint8_t * value, uint16_t value_size){
232     l2cap_reserve_packet_buffer();
233     uint8_t * request = l2cap_get_outgoing_buffer();
234 
235     request[0] = request_type;
236     little_endian_store_16(request, 1, start_handle);
237     little_endian_store_16(request, 3, end_handle);
238     little_endian_store_16(request, 5, attribute_group_type);
239     (void)memcpy(&request[7], value, value_size);
240 
241     return l2cap_send_prepared_connectionless(con_handle, L2CAP_CID_ATTRIBUTE_PROTOCOL, 7u + value_size);
242 }
243 
244 // precondition: can_send_packet_now == TRUE
245 static uint8_t att_read_by_type_or_group_request_for_uuid16(uint16_t request_type, uint16_t uuid16, uint16_t con_handle, uint16_t start_handle, uint16_t end_handle){
246     l2cap_reserve_packet_buffer();
247     uint8_t * request = l2cap_get_outgoing_buffer();
248     request[0] = request_type;
249     little_endian_store_16(request, 1, start_handle);
250     little_endian_store_16(request, 3, end_handle);
251     little_endian_store_16(request, 5, uuid16);
252 
253     return l2cap_send_prepared_connectionless(con_handle, L2CAP_CID_ATTRIBUTE_PROTOCOL, 7);
254 }
255 
256 // precondition: can_send_packet_now == TRUE
257 static uint8_t att_read_by_type_or_group_request_for_uuid128(uint16_t request_type, uint8_t * uuid128, uint16_t con_handle, uint16_t start_handle, uint16_t end_handle){
258     l2cap_reserve_packet_buffer();
259     uint8_t * request = l2cap_get_outgoing_buffer();
260     request[0] = request_type;
261     little_endian_store_16(request, 1, start_handle);
262     little_endian_store_16(request, 3, end_handle);
263     reverse_128(uuid128, &request[5]);
264 
265     return l2cap_send_prepared_connectionless(con_handle, L2CAP_CID_ATTRIBUTE_PROTOCOL, 21);
266 }
267 
268 // precondition: can_send_packet_now == TRUE
269 static uint8_t att_read_request(uint16_t request_type, uint16_t con_handle, uint16_t attribute_handle){
270     l2cap_reserve_packet_buffer();
271     uint8_t * request = l2cap_get_outgoing_buffer();
272     request[0] = request_type;
273     little_endian_store_16(request, 1, attribute_handle);
274 
275     return l2cap_send_prepared_connectionless(con_handle, L2CAP_CID_ATTRIBUTE_PROTOCOL, 3);
276 }
277 
278 // precondition: can_send_packet_now == TRUE
279 static uint8_t att_read_blob_request(uint16_t request_type, uint16_t con_handle, uint16_t attribute_handle, uint16_t value_offset){
280     l2cap_reserve_packet_buffer();
281     uint8_t * request = l2cap_get_outgoing_buffer();
282     request[0] = request_type;
283     little_endian_store_16(request, 1, attribute_handle);
284     little_endian_store_16(request, 3, value_offset);
285 
286     return l2cap_send_prepared_connectionless(con_handle, L2CAP_CID_ATTRIBUTE_PROTOCOL, 5);
287 }
288 
289 static uint8_t att_read_multiple_request(uint16_t con_handle, uint16_t num_value_handles, uint16_t * value_handles){
290     l2cap_reserve_packet_buffer();
291     uint8_t * request = l2cap_get_outgoing_buffer();
292     request[0] = ATT_READ_MULTIPLE_REQUEST;
293     int i;
294     int offset = 1;
295     for (i=0;i<num_value_handles;i++){
296         little_endian_store_16(request, offset, value_handles[i]);
297         offset += 2;
298     }
299 
300     return l2cap_send_prepared_connectionless(con_handle, L2CAP_CID_ATTRIBUTE_PROTOCOL, offset);
301 }
302 
303 #ifdef ENABLE_LE_SIGNED_WRITE
304 // precondition: can_send_packet_now == TRUE
305 static uint8_t att_signed_write_request(uint16_t request_type, uint16_t con_handle, uint16_t attribute_handle, uint16_t value_length, uint8_t * value, uint32_t sign_counter, uint8_t sgn[8]){
306     l2cap_reserve_packet_buffer();
307     uint8_t * request = l2cap_get_outgoing_buffer();
308     request[0] = request_type;
309     little_endian_store_16(request, 1, attribute_handle);
310     (void)memcpy(&request[3], value, value_length);
311     little_endian_store_32(request, 3 + value_length, sign_counter);
312     reverse_64(sgn, &request[3 + value_length + 4]);
313 
314     return l2cap_send_prepared_connectionless(con_handle, L2CAP_CID_ATTRIBUTE_PROTOCOL, 3 + value_length + 12);
315 }
316 #endif
317 
318 // precondition: can_send_packet_now == TRUE
319 static uint8_t att_write_request(uint16_t request_type, uint16_t con_handle, uint16_t attribute_handle, uint16_t value_length, uint8_t * value){
320     l2cap_reserve_packet_buffer();
321     uint8_t * request = l2cap_get_outgoing_buffer();
322     request[0] = request_type;
323     little_endian_store_16(request, 1, attribute_handle);
324     (void)memcpy(&request[3], value, value_length);
325 
326     return l2cap_send_prepared_connectionless(con_handle, L2CAP_CID_ATTRIBUTE_PROTOCOL, 3u + value_length);
327 }
328 
329 // precondition: can_send_packet_now == TRUE
330 static uint8_t att_execute_write_request(uint16_t request_type, uint16_t con_handle, uint8_t execute_write){
331     l2cap_reserve_packet_buffer();
332     uint8_t * request = l2cap_get_outgoing_buffer();
333     request[0] = request_type;
334     request[1] = execute_write;
335 
336     return l2cap_send_prepared_connectionless(con_handle, L2CAP_CID_ATTRIBUTE_PROTOCOL, 2);
337 }
338 
339 // precondition: can_send_packet_now == TRUE
340 static uint8_t att_prepare_write_request(uint16_t request_type, uint16_t con_handle, uint16_t attribute_handle, uint16_t value_offset, uint16_t blob_length, uint8_t * value){
341     l2cap_reserve_packet_buffer();
342     uint8_t * request = l2cap_get_outgoing_buffer();
343     request[0] = request_type;
344     little_endian_store_16(request, 1, attribute_handle);
345     little_endian_store_16(request, 3, value_offset);
346     (void)memcpy(&request[5], &value[value_offset], blob_length);
347 
348     return l2cap_send_prepared_connectionless(con_handle, L2CAP_CID_ATTRIBUTE_PROTOCOL, 5u + blob_length);
349 }
350 
351 static uint8_t att_exchange_mtu_request(uint16_t con_handle){
352     uint16_t mtu = l2cap_max_le_mtu();
353     l2cap_reserve_packet_buffer();
354     uint8_t * request = l2cap_get_outgoing_buffer();
355     request[0] = ATT_EXCHANGE_MTU_REQUEST;
356     little_endian_store_16(request, 1, mtu);
357 
358     return l2cap_send_prepared_connectionless(con_handle, L2CAP_CID_ATTRIBUTE_PROTOCOL, 3);
359 }
360 
361 static uint16_t write_blob_length(gatt_client_t * gatt_client){
362     uint16_t max_blob_length = gatt_client_mtu(gatt_client) - 5u;
363     if (gatt_client->attribute_offset >= gatt_client->attribute_length) {
364         return 0;
365     }
366     uint16_t rest_length = gatt_client->attribute_length - gatt_client->attribute_offset;
367     if (max_blob_length > rest_length){
368         return rest_length;
369     }
370     return max_blob_length;
371 }
372 
373 static void send_gatt_services_request(gatt_client_t *gatt_client){
374     att_read_by_type_or_group_request_for_uuid16(ATT_READ_BY_GROUP_TYPE_REQUEST, GATT_PRIMARY_SERVICE_UUID, gatt_client->con_handle, gatt_client->start_group_handle, gatt_client->end_group_handle);
375 }
376 
377 static void send_gatt_by_uuid_request(gatt_client_t *gatt_client, uint16_t attribute_group_type){
378     if (gatt_client->uuid16){
379         uint8_t uuid16[2];
380         little_endian_store_16(uuid16, 0, gatt_client->uuid16);
381         att_find_by_type_value_request(ATT_FIND_BY_TYPE_VALUE_REQUEST, attribute_group_type, gatt_client->con_handle, gatt_client->start_group_handle, gatt_client->end_group_handle, uuid16, 2);
382         return;
383     }
384     uint8_t uuid128[16];
385     reverse_128(gatt_client->uuid128, uuid128);
386     att_find_by_type_value_request(ATT_FIND_BY_TYPE_VALUE_REQUEST, attribute_group_type, gatt_client->con_handle, gatt_client->start_group_handle, gatt_client->end_group_handle, uuid128, 16);
387 }
388 
389 static void send_gatt_services_by_uuid_request(gatt_client_t *gatt_client){
390     send_gatt_by_uuid_request(gatt_client, GATT_PRIMARY_SERVICE_UUID);
391 }
392 
393 static void send_gatt_included_service_uuid_request(gatt_client_t *gatt_client){
394     att_read_request(ATT_READ_REQUEST, gatt_client->con_handle, gatt_client->query_start_handle);
395 }
396 
397 static void send_gatt_included_service_request(gatt_client_t *gatt_client){
398     att_read_by_type_or_group_request_for_uuid16(ATT_READ_BY_TYPE_REQUEST, GATT_INCLUDE_SERVICE_UUID, gatt_client->con_handle, gatt_client->start_group_handle, gatt_client->end_group_handle);
399 }
400 
401 static void send_gatt_characteristic_request(gatt_client_t *gatt_client){
402     att_read_by_type_or_group_request_for_uuid16(ATT_READ_BY_TYPE_REQUEST, GATT_CHARACTERISTICS_UUID, gatt_client->con_handle, gatt_client->start_group_handle, gatt_client->end_group_handle);
403 }
404 
405 static void send_gatt_characteristic_descriptor_request(gatt_client_t *gatt_client){
406     att_find_information_request(ATT_FIND_INFORMATION_REQUEST, gatt_client->con_handle, gatt_client->start_group_handle, gatt_client->end_group_handle);
407 }
408 
409 static void send_gatt_read_characteristic_value_request(gatt_client_t *gatt_client){
410     att_read_request(ATT_READ_REQUEST, gatt_client->con_handle, gatt_client->attribute_handle);
411 }
412 
413 static void send_gatt_read_by_type_request(gatt_client_t * gatt_client){
414     if (gatt_client->uuid16){
415         att_read_by_type_or_group_request_for_uuid16(ATT_READ_BY_TYPE_REQUEST, gatt_client->uuid16, gatt_client->con_handle, gatt_client->start_group_handle, gatt_client->end_group_handle);
416     } else {
417         att_read_by_type_or_group_request_for_uuid128(ATT_READ_BY_TYPE_REQUEST, gatt_client->uuid128, gatt_client->con_handle, gatt_client->start_group_handle, gatt_client->end_group_handle);
418     }
419 }
420 
421 static void send_gatt_read_blob_request(gatt_client_t *gatt_client){
422     att_read_blob_request(ATT_READ_BLOB_REQUEST, gatt_client->con_handle, gatt_client->attribute_handle, gatt_client->attribute_offset);
423 }
424 
425 static void send_gatt_read_multiple_request(gatt_client_t * gatt_client){
426     att_read_multiple_request(gatt_client->con_handle, gatt_client->read_multiple_handle_count, gatt_client->read_multiple_handles);
427 }
428 
429 static void send_gatt_write_attribute_value_request(gatt_client_t * gatt_client){
430     att_write_request(ATT_WRITE_REQUEST, gatt_client->con_handle, gatt_client->attribute_handle, gatt_client->attribute_length, gatt_client->attribute_value);
431 }
432 
433 static void send_gatt_write_client_characteristic_configuration_request(gatt_client_t * gatt_client){
434     att_write_request(ATT_WRITE_REQUEST, gatt_client->con_handle, gatt_client->client_characteristic_configuration_handle, 2, gatt_client->client_characteristic_configuration_value);
435 }
436 
437 static void send_gatt_prepare_write_request(gatt_client_t * gatt_client){
438     att_prepare_write_request(ATT_PREPARE_WRITE_REQUEST, gatt_client->con_handle, gatt_client->attribute_handle, gatt_client->attribute_offset, write_blob_length(gatt_client), gatt_client->attribute_value);
439 }
440 
441 static void send_gatt_execute_write_request(gatt_client_t * gatt_client){
442     att_execute_write_request(ATT_EXECUTE_WRITE_REQUEST, gatt_client->con_handle, 1);
443 }
444 
445 static void send_gatt_cancel_prepared_write_request(gatt_client_t * gatt_client){
446     att_execute_write_request(ATT_EXECUTE_WRITE_REQUEST, gatt_client->con_handle, 0);
447 }
448 
449 #ifndef ENABLE_GATT_FIND_INFORMATION_FOR_CCC_DISCOVERY
450 static void send_gatt_read_client_characteristic_configuration_request(gatt_client_t * gatt_client){
451     att_read_by_type_or_group_request_for_uuid16(ATT_READ_BY_TYPE_REQUEST, GATT_CLIENT_CHARACTERISTICS_CONFIGURATION, gatt_client->con_handle, gatt_client->start_group_handle, gatt_client->end_group_handle);
452 }
453 #endif
454 
455 static void send_gatt_read_characteristic_descriptor_request(gatt_client_t * gatt_client){
456     att_read_request(ATT_READ_REQUEST, gatt_client->con_handle, gatt_client->attribute_handle);
457 }
458 
459 #ifdef ENABLE_LE_SIGNED_WRITE
460 static void send_gatt_signed_write_request(gatt_client_t * gatt_client, uint32_t sign_counter){
461     att_signed_write_request(ATT_SIGNED_WRITE_COMMAND, gatt_client->con_handle, gatt_client->attribute_handle, gatt_client->attribute_length, gatt_client->attribute_value, sign_counter, gatt_client->cmac);
462 }
463 #endif
464 
465 static uint16_t get_last_result_handle_from_service_list(uint8_t * packet, uint16_t size){
466     uint8_t attr_length = packet[1];
467     return little_endian_read_16(packet, size - attr_length + 2u);
468 }
469 
470 static uint16_t get_last_result_handle_from_characteristics_list(uint8_t * packet, uint16_t size){
471     uint8_t attr_length = packet[1];
472     return little_endian_read_16(packet, size - attr_length + 3u);
473 }
474 
475 static uint16_t get_last_result_handle_from_included_services_list(uint8_t * packet, uint16_t size){
476     uint8_t attr_length = packet[1];
477     return little_endian_read_16(packet, size - attr_length);
478 }
479 
480 static void gatt_client_handle_transaction_complete(gatt_client_t * gatt_client){
481     gatt_client->gatt_client_state = P_READY;
482     gatt_client_timeout_stop(gatt_client);
483 }
484 
485 static void emit_event_new(btstack_packet_handler_t callback, uint8_t * packet, uint16_t size){
486     if (!callback) return;
487     hci_dump_packet(HCI_EVENT_PACKET, 0, packet, size);
488     (*callback)(HCI_EVENT_PACKET, 0, packet, size);
489 }
490 
491 void gatt_client_listen_for_characteristic_value_updates(gatt_client_notification_t * notification, btstack_packet_handler_t packet_handler, hci_con_handle_t con_handle, gatt_client_characteristic_t * characteristic){
492     notification->callback = packet_handler;
493     notification->con_handle = con_handle;
494     if (characteristic == NULL){
495         notification->attribute_handle = GATT_CLIENT_ANY_VALUE_HANDLE;
496     } else {
497         notification->attribute_handle = characteristic->value_handle;
498     }
499     btstack_linked_list_add(&gatt_client_value_listeners, (btstack_linked_item_t*) notification);
500 }
501 
502 void gatt_client_stop_listening_for_characteristic_value_updates(gatt_client_notification_t * notification){
503     btstack_linked_list_remove(&gatt_client_value_listeners, (btstack_linked_item_t*) notification);
504 }
505 
506 static void emit_event_to_registered_listeners(hci_con_handle_t con_handle, uint16_t attribute_handle, uint8_t * packet, uint16_t size){
507     btstack_linked_list_iterator_t it;
508     btstack_linked_list_iterator_init(&it, &gatt_client_value_listeners);
509     while (btstack_linked_list_iterator_has_next(&it)){
510         gatt_client_notification_t * notification = (gatt_client_notification_t*) btstack_linked_list_iterator_next(&it);
511         if ((notification->con_handle       != GATT_CLIENT_ANY_CONNECTION)   && (notification->con_handle       != con_handle)) continue;
512         if ((notification->attribute_handle != GATT_CLIENT_ANY_VALUE_HANDLE) && (notification->attribute_handle != attribute_handle)) continue;
513         (*notification->callback)(HCI_EVENT_PACKET, 0, packet, size);
514     }
515 }
516 
517 static void emit_gatt_complete_event(gatt_client_t * gatt_client, uint8_t att_status){
518     // @format H1
519     uint8_t packet[5];
520     packet[0] = GATT_EVENT_QUERY_COMPLETE;
521     packet[1] = 3;
522     little_endian_store_16(packet, 2, gatt_client->con_handle);
523     packet[4] = att_status;
524     emit_event_new(gatt_client->callback, packet, sizeof(packet));
525 }
526 
527 static void emit_gatt_service_query_result_event(gatt_client_t * gatt_client, uint16_t start_group_handle, uint16_t end_group_handle, uint8_t * uuid128){
528     // @format HX
529     uint8_t packet[24];
530     packet[0] = GATT_EVENT_SERVICE_QUERY_RESULT;
531     packet[1] = sizeof(packet) - 2u;
532     little_endian_store_16(packet, 2, gatt_client->con_handle);
533     ///
534     little_endian_store_16(packet, 4, start_group_handle);
535     little_endian_store_16(packet, 6, end_group_handle);
536     reverse_128(uuid128, &packet[8]);
537     emit_event_new(gatt_client->callback, packet, sizeof(packet));
538 }
539 
540 static void emit_gatt_included_service_query_result_event(gatt_client_t * gatt_client, uint16_t include_handle, uint16_t start_group_handle, uint16_t end_group_handle, uint8_t * uuid128){
541     // @format HX
542     uint8_t packet[26];
543     packet[0] = GATT_EVENT_INCLUDED_SERVICE_QUERY_RESULT;
544     packet[1] = sizeof(packet) - 2u;
545     little_endian_store_16(packet, 2, gatt_client->con_handle);
546     ///
547     little_endian_store_16(packet, 4, include_handle);
548     //
549     little_endian_store_16(packet, 6, start_group_handle);
550     little_endian_store_16(packet, 8, end_group_handle);
551     reverse_128(uuid128, &packet[10]);
552     emit_event_new(gatt_client->callback, packet, sizeof(packet));
553 }
554 
555 static void emit_gatt_characteristic_query_result_event(gatt_client_t * gatt_client, uint16_t start_handle, uint16_t value_handle, uint16_t end_handle,
556                                                         uint16_t properties, uint8_t * uuid128){
557     // @format HY
558     uint8_t packet[28];
559     packet[0] = GATT_EVENT_CHARACTERISTIC_QUERY_RESULT;
560     packet[1] = sizeof(packet) - 2u;
561     little_endian_store_16(packet, 2, gatt_client->con_handle);
562     ///
563     little_endian_store_16(packet, 4,  start_handle);
564     little_endian_store_16(packet, 6,  value_handle);
565     little_endian_store_16(packet, 8,  end_handle);
566     little_endian_store_16(packet, 10, properties);
567     reverse_128(uuid128, &packet[12]);
568     emit_event_new(gatt_client->callback, packet, sizeof(packet));
569 }
570 
571 static void emit_gatt_all_characteristic_descriptors_result_event(
572         gatt_client_t * gatt_client, uint16_t descriptor_handle, uint8_t * uuid128){
573     // @format HZ
574     uint8_t packet[22];
575     packet[0] = GATT_EVENT_ALL_CHARACTERISTIC_DESCRIPTORS_QUERY_RESULT;
576     packet[1] = sizeof(packet) - 2u;
577     little_endian_store_16(packet, 2, gatt_client->con_handle);
578     ///
579     little_endian_store_16(packet, 4,  descriptor_handle);
580     reverse_128(uuid128, &packet[6]);
581     emit_event_new(gatt_client->callback, packet, sizeof(packet));
582 }
583 
584 static void emit_gatt_mtu_exchanged_result_event(gatt_client_t * gatt_client, uint16_t new_mtu){
585     // @format H2
586     uint8_t packet[6];
587     packet[0] = GATT_EVENT_MTU;
588     packet[1] = sizeof(packet) - 2u;
589     little_endian_store_16(packet, 2, gatt_client->con_handle);
590     little_endian_store_16(packet, 4, new_mtu);
591     att_dispatch_client_mtu_exchanged(gatt_client->con_handle, new_mtu);
592     emit_event_new(gatt_client->callback, packet, sizeof(packet));
593 }
594 ///
595 static void report_gatt_services(gatt_client_t * gatt_client, uint8_t * packet, uint16_t size){
596     uint8_t attr_length = packet[1];
597     uint8_t uuid_length = attr_length - 4u;
598 
599     int i;
600     for (i = 2; i < size; i += attr_length){
601         uint16_t start_group_handle = little_endian_read_16(packet,i);
602         uint16_t end_group_handle   = little_endian_read_16(packet,i+2);
603         uint8_t  uuid128[16];
604         uint16_t uuid16 = 0;
605 
606         if (uuid_length == 2u){
607             uuid16 = little_endian_read_16(packet, i+4);
608             uuid_add_bluetooth_prefix((uint8_t*) &uuid128, uuid16);
609         } else {
610             reverse_128(&packet[i+4], uuid128);
611         }
612         emit_gatt_service_query_result_event(gatt_client, start_group_handle, end_group_handle, uuid128);
613     }
614 }
615 
616 // helper
617 static void characteristic_start_found(gatt_client_t * gatt_client, uint16_t start_handle, uint8_t properties, uint16_t value_handle, uint8_t * uuid, uint16_t uuid_length){
618     uint8_t uuid128[16];
619     uint16_t uuid16 = 0;
620     if (uuid_length == 2u){
621         uuid16 = little_endian_read_16(uuid, 0);
622         uuid_add_bluetooth_prefix((uint8_t*) uuid128, uuid16);
623     } else if (uuid_length == 16u){
624         reverse_128(uuid, uuid128);
625     } else {
626         return;
627     }
628 
629     if (gatt_client->filter_with_uuid && (memcmp(gatt_client->uuid128, uuid128, 16) != 0)) return;
630 
631     gatt_client->characteristic_properties = properties;
632     gatt_client->characteristic_start_handle = start_handle;
633     gatt_client->attribute_handle = value_handle;
634 
635     if (gatt_client->filter_with_uuid) return;
636 
637     gatt_client->uuid16 = uuid16;
638     (void)memcpy(gatt_client->uuid128, uuid128, 16);
639 }
640 
641 static void characteristic_end_found(gatt_client_t * gatt_client, uint16_t end_handle){
642     // TODO: stop searching if filter and uuid found
643 
644     if (!gatt_client->characteristic_start_handle) return;
645 
646     emit_gatt_characteristic_query_result_event(gatt_client, gatt_client->characteristic_start_handle, gatt_client->attribute_handle,
647                                                 end_handle, gatt_client->characteristic_properties, gatt_client->uuid128);
648 
649     gatt_client->characteristic_start_handle = 0;
650 }
651 
652 static void report_gatt_characteristics(gatt_client_t * gatt_client, uint8_t * packet, uint16_t size){
653     if (size < 2u) return;
654     uint8_t attr_length = packet[1];
655     if ((attr_length != 7u) && (attr_length != 21u)) return;
656     uint8_t uuid_length = attr_length - 5u;
657     int i;
658     for (i = 2u; (i + attr_length) <= size; i += attr_length){
659         uint16_t start_handle = little_endian_read_16(packet, i);
660         uint8_t  properties = packet[i+2];
661         uint16_t value_handle = little_endian_read_16(packet, i+3);
662         characteristic_end_found(gatt_client, start_handle - 1u);
663         characteristic_start_found(gatt_client, start_handle, properties, value_handle, &packet[i + 5], uuid_length);
664     }
665 }
666 
667 static void report_gatt_included_service_uuid16(gatt_client_t * gatt_client, uint16_t include_handle, uint16_t uuid16){
668     uint8_t normalized_uuid128[16];
669     uuid_add_bluetooth_prefix(normalized_uuid128, uuid16);
670     emit_gatt_included_service_query_result_event(gatt_client, include_handle, gatt_client->query_start_handle,
671                                                   gatt_client->query_end_handle, normalized_uuid128);
672 }
673 
674 static void report_gatt_included_service_uuid128(gatt_client_t * gatt_client, uint16_t include_handle, uint8_t *uuid128){
675     emit_gatt_included_service_query_result_event(gatt_client, include_handle, gatt_client->query_start_handle,
676                                                   gatt_client->query_end_handle, uuid128);
677 }
678 
679 // @returns packet pointer
680 // @note assume that value is part of an l2cap buffer - overwrite HCI + L2CAP packet headers
681 static const int characteristic_value_event_header_size = 8;
682 static uint8_t * setup_characteristic_value_packet(uint8_t type, hci_con_handle_t con_handle, uint16_t attribute_handle, uint8_t * value, uint16_t length){
683 #ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
684     // avoid using pre ATT headers.
685     return NULL;
686 #endif
687     // before the value inside the ATT PDU
688     uint8_t * packet = value - characteristic_value_event_header_size;
689     packet[0] = type;
690     packet[1] = characteristic_value_event_header_size - 2 + length;
691     little_endian_store_16(packet, 2, con_handle);
692     little_endian_store_16(packet, 4, attribute_handle);
693     little_endian_store_16(packet, 6, length);
694     return packet;
695 }
696 
697 // @returns packet pointer
698 // @note assume that value is part of an l2cap buffer - overwrite parts of the HCI/L2CAP/ATT packet (4/4/3) bytes
699 static const int long_characteristic_value_event_header_size = 10;
700 static uint8_t * setup_long_characteristic_value_packet(uint8_t type, hci_con_handle_t con_handle, uint16_t attribute_handle, uint16_t offset, uint8_t * value, uint16_t length){
701 #ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
702     // avoid using pre ATT headers.
703     return NULL;
704 #endif
705 #if defined(HCI_INCOMING_PRE_BUFFER_SIZE) && (HCI_INCOMING_PRE_BUFFER_SIZE >= 10 - 8) // L2CAP Header (4) - ACL Header (4)
706     // before the value inside the ATT PDU
707     uint8_t * packet = value - long_characteristic_value_event_header_size;
708     packet[0] = type;
709     packet[1] = long_characteristic_value_event_header_size - 2 + length;
710     little_endian_store_16(packet, 2, con_handle);
711     little_endian_store_16(packet, 4, attribute_handle);
712     little_endian_store_16(packet, 6, offset);
713     little_endian_store_16(packet, 8, length);
714     return packet;
715 #else
716     log_error("HCI_INCOMING_PRE_BUFFER_SIZE >= 2 required for long characteristic reads");
717     return NULL;
718 #endif
719 }
720 
721 
722 // @note assume that value is part of an l2cap buffer - overwrite parts of the HCI/L2CAP/ATT packet (4/4/3) bytes
723 static void report_gatt_notification(hci_con_handle_t con_handle, uint16_t value_handle, uint8_t * value, int length){
724     uint8_t * packet = setup_characteristic_value_packet(GATT_EVENT_NOTIFICATION, con_handle, value_handle, value, length);
725     emit_event_to_registered_listeners(con_handle, value_handle, packet, characteristic_value_event_header_size + length);
726 }
727 
728 // @note assume that value is part of an l2cap buffer - overwrite parts of the HCI/L2CAP/ATT packet (4/4/3) bytes
729 static void report_gatt_indication(hci_con_handle_t con_handle, uint16_t value_handle, uint8_t * value, int length){
730     uint8_t * packet = setup_characteristic_value_packet(GATT_EVENT_INDICATION, con_handle, value_handle, value, length);
731     emit_event_to_registered_listeners(con_handle, value_handle, packet, characteristic_value_event_header_size + length);
732 }
733 
734 // @note assume that value is part of an l2cap buffer - overwrite parts of the HCI/L2CAP/ATT packet (4/4/3) bytes
735 static void report_gatt_characteristic_value(gatt_client_t * gatt_client, uint16_t attribute_handle, uint8_t * value, uint16_t length){
736     uint8_t * packet = setup_characteristic_value_packet(GATT_EVENT_CHARACTERISTIC_VALUE_QUERY_RESULT, gatt_client->con_handle, attribute_handle, value, length);
737     emit_event_new(gatt_client->callback, packet, characteristic_value_event_header_size + length);
738 }
739 
740 // @note assume that value is part of an l2cap buffer - overwrite parts of the HCI/L2CAP/ATT packet (4/4/3) bytes
741 static void report_gatt_long_characteristic_value_blob(gatt_client_t * gatt_client, uint16_t attribute_handle, uint8_t * blob, uint16_t blob_length, int value_offset){
742     uint8_t * packet = setup_long_characteristic_value_packet(GATT_EVENT_LONG_CHARACTERISTIC_VALUE_QUERY_RESULT, gatt_client->con_handle, attribute_handle, value_offset, blob, blob_length);
743     if (!packet) return;
744     emit_event_new(gatt_client->callback, packet, blob_length + long_characteristic_value_event_header_size);
745 }
746 
747 static void report_gatt_characteristic_descriptor(gatt_client_t * gatt_client, uint16_t descriptor_handle, uint8_t *value, uint16_t value_length, uint16_t value_offset){
748     UNUSED(value_offset);
749     uint8_t * packet = setup_characteristic_value_packet(GATT_EVENT_CHARACTERISTIC_DESCRIPTOR_QUERY_RESULT, gatt_client->con_handle, descriptor_handle, value, value_length);
750     emit_event_new(gatt_client->callback, packet, value_length + 8u);
751 }
752 
753 static void report_gatt_long_characteristic_descriptor(gatt_client_t * gatt_client, uint16_t descriptor_handle, uint8_t *blob, uint16_t blob_length, uint16_t value_offset){
754     uint8_t * packet = setup_long_characteristic_value_packet(GATT_EVENT_LONG_CHARACTERISTIC_DESCRIPTOR_QUERY_RESULT, gatt_client->con_handle, descriptor_handle, value_offset, blob, blob_length);
755     if (!packet) return;
756     emit_event_new(gatt_client->callback, packet, blob_length + long_characteristic_value_event_header_size);
757 }
758 
759 static void report_gatt_all_characteristic_descriptors(gatt_client_t * gatt_client, uint8_t * packet, uint16_t size, uint16_t pair_size){
760     int i;
761     for (i = 0u; (i + pair_size) <= size; i += pair_size){
762         uint16_t descriptor_handle = little_endian_read_16(packet,i);
763         uint8_t uuid128[16];
764         uint16_t uuid16 = 0;
765         if (pair_size == 4u){
766             uuid16 = little_endian_read_16(packet,i+2);
767             uuid_add_bluetooth_prefix(uuid128, uuid16);
768         } else {
769             reverse_128(&packet[i+2], uuid128);
770         }
771         emit_gatt_all_characteristic_descriptors_result_event(gatt_client, descriptor_handle, uuid128);
772     }
773 
774 }
775 
776 static int is_query_done(gatt_client_t * gatt_client, uint16_t last_result_handle){
777     return last_result_handle >= gatt_client->end_group_handle;
778 }
779 
780 static void trigger_next_query(gatt_client_t * gatt_client, uint16_t last_result_handle, gatt_client_state_t next_query_state){
781     if (is_query_done(gatt_client, last_result_handle)){
782         gatt_client_handle_transaction_complete(gatt_client);
783         emit_gatt_complete_event(gatt_client, ATT_ERROR_SUCCESS);
784         return;
785     }
786     // next
787     gatt_client->start_group_handle = last_result_handle + 1u;
788     gatt_client->gatt_client_state = next_query_state;
789 }
790 
791 static void trigger_next_included_service_query(gatt_client_t * gatt_client, uint16_t last_result_handle){
792     trigger_next_query(gatt_client, last_result_handle, P_W2_SEND_INCLUDED_SERVICE_QUERY);
793 }
794 
795 static void trigger_next_service_query(gatt_client_t * gatt_client, uint16_t last_result_handle){
796     trigger_next_query(gatt_client, last_result_handle, P_W2_SEND_SERVICE_QUERY);
797 }
798 
799 static void trigger_next_service_by_uuid_query(gatt_client_t * gatt_client, uint16_t last_result_handle){
800     trigger_next_query(gatt_client, last_result_handle, P_W2_SEND_SERVICE_WITH_UUID_QUERY);
801 }
802 
803 static void trigger_next_characteristic_query(gatt_client_t * gatt_client, uint16_t last_result_handle){
804     if (is_query_done(gatt_client, last_result_handle)){
805         // report last characteristic
806         characteristic_end_found(gatt_client, gatt_client->end_group_handle);
807     }
808     trigger_next_query(gatt_client, last_result_handle, P_W2_SEND_ALL_CHARACTERISTICS_OF_SERVICE_QUERY);
809 }
810 
811 static void trigger_next_characteristic_descriptor_query(gatt_client_t * gatt_client, uint16_t last_result_handle){
812     trigger_next_query(gatt_client, last_result_handle, P_W2_SEND_ALL_CHARACTERISTIC_DESCRIPTORS_QUERY);
813 }
814 
815 static void trigger_next_read_by_type_query(gatt_client_t * gatt_client, uint16_t last_result_handle){
816     trigger_next_query(gatt_client, last_result_handle, P_W2_SEND_READ_BY_TYPE_REQUEST);
817 }
818 
819 static void trigger_next_prepare_write_query(gatt_client_t * gatt_client, gatt_client_state_t next_query_state, gatt_client_state_t done_state){
820     gatt_client->attribute_offset += write_blob_length(gatt_client);
821     uint16_t next_blob_length =  write_blob_length(gatt_client);
822 
823     if (next_blob_length == 0u){
824         gatt_client->gatt_client_state = done_state;
825         return;
826     }
827     gatt_client->gatt_client_state = next_query_state;
828 }
829 
830 static void trigger_next_blob_query(gatt_client_t * gatt_client, gatt_client_state_t next_query_state, uint16_t received_blob_length){
831 
832     uint16_t max_blob_length = gatt_client_mtu(gatt_client) - 1u;
833     if (received_blob_length < max_blob_length){
834         gatt_client_handle_transaction_complete(gatt_client);
835         emit_gatt_complete_event(gatt_client, ATT_ERROR_SUCCESS);
836         return;
837     }
838 
839     gatt_client->attribute_offset += received_blob_length;
840     gatt_client->gatt_client_state = next_query_state;
841 }
842 
843 
844 static int is_value_valid(gatt_client_t *gatt_client, uint8_t *packet, uint16_t size){
845     uint16_t attribute_handle = little_endian_read_16(packet, 1);
846     uint16_t value_offset = little_endian_read_16(packet, 3);
847 
848     if (gatt_client->attribute_handle != attribute_handle) return 0;
849     if (gatt_client->attribute_offset != value_offset) return 0;
850     return memcmp(&gatt_client->attribute_value[gatt_client->attribute_offset], &packet[5], size - 5u) == 0u;
851 }
852 
853 // returns 1 if packet was sent
854 static int gatt_client_run_for_gatt_client(gatt_client_t * gatt_client){
855 
856     // wait until re-encryption as central is complete
857     if (gap_reconnect_security_setup_active(gatt_client->con_handle)) return 0;
858 
859 #ifdef ENABLE_GATT_CLIENT_PAIRING
860     // wait until pairing complete
861     if (gatt_client->wait_for_pairing_complete) return 0;
862 #endif
863 
864     switch (gatt_client->mtu_state) {
865         case SEND_MTU_EXCHANGE:
866             gatt_client->mtu_state = SENT_MTU_EXCHANGE;
867             att_exchange_mtu_request(gatt_client->con_handle);
868             return 1;
869         case SENT_MTU_EXCHANGE:
870             return 0;
871         default:
872             break;
873     }
874 
875     if (gatt_client->send_confirmation){
876         gatt_client->send_confirmation = 0;
877         att_confirmation(gatt_client->con_handle);
878         return 1;
879     }
880 
881     // check MTU for writes
882     switch (gatt_client->gatt_client_state){
883         case P_W2_SEND_WRITE_CHARACTERISTIC_VALUE:
884         case P_W2_SEND_WRITE_CHARACTERISTIC_DESCRIPTOR:
885             if (gatt_client->attribute_length <= (gatt_client_mtu(gatt_client) - 3u)) break;
886             log_error("gatt_client_run: value len %u > MTU %u - 3\n", gatt_client->attribute_length,
887                       gatt_client_mtu(gatt_client));
888             gatt_client_handle_transaction_complete(gatt_client);
889             emit_gatt_complete_event(gatt_client, ATT_ERROR_INVALID_ATTRIBUTE_VALUE_LENGTH);
890             return 0;
891         default:
892             break;
893     }
894 
895     switch (gatt_client->gatt_client_state){
896         case P_W2_SEND_SERVICE_QUERY:
897             gatt_client->gatt_client_state = P_W4_SERVICE_QUERY_RESULT;
898             send_gatt_services_request(gatt_client);
899             return 1;
900 
901         case P_W2_SEND_SERVICE_WITH_UUID_QUERY:
902             gatt_client->gatt_client_state = P_W4_SERVICE_WITH_UUID_RESULT;
903             send_gatt_services_by_uuid_request(gatt_client);
904             return 1;
905 
906         case P_W2_SEND_ALL_CHARACTERISTICS_OF_SERVICE_QUERY:
907             gatt_client->gatt_client_state = P_W4_ALL_CHARACTERISTICS_OF_SERVICE_QUERY_RESULT;
908             send_gatt_characteristic_request(gatt_client);
909             return 1;
910 
911         case P_W2_SEND_CHARACTERISTIC_WITH_UUID_QUERY:
912             gatt_client->gatt_client_state = P_W4_CHARACTERISTIC_WITH_UUID_QUERY_RESULT;
913             send_gatt_characteristic_request(gatt_client);
914             return 1;
915 
916         case P_W2_SEND_ALL_CHARACTERISTIC_DESCRIPTORS_QUERY:
917             gatt_client->gatt_client_state = P_W4_CHARACTERISTIC_WITH_UUID_QUERY_RESULT;
918             send_gatt_characteristic_descriptor_request(gatt_client);
919             return 1;
920 
921         case P_W2_SEND_INCLUDED_SERVICE_QUERY:
922             gatt_client->gatt_client_state = P_W4_INCLUDED_SERVICE_QUERY_RESULT;
923             send_gatt_included_service_request(gatt_client);
924             return 1;
925 
926         case P_W2_SEND_INCLUDED_SERVICE_WITH_UUID_QUERY:
927             gatt_client->gatt_client_state = P_W4_INCLUDED_SERVICE_UUID_WITH_QUERY_RESULT;
928             send_gatt_included_service_uuid_request(gatt_client);
929             return 1;
930 
931         case P_W2_SEND_READ_CHARACTERISTIC_VALUE_QUERY:
932             gatt_client->gatt_client_state = P_W4_READ_CHARACTERISTIC_VALUE_RESULT;
933             send_gatt_read_characteristic_value_request(gatt_client);
934             return 1;
935 
936         case P_W2_SEND_READ_BLOB_QUERY:
937             gatt_client->gatt_client_state = P_W4_READ_BLOB_RESULT;
938             send_gatt_read_blob_request(gatt_client);
939             return 1;
940 
941         case P_W2_SEND_READ_BY_TYPE_REQUEST:
942             gatt_client->gatt_client_state = P_W4_READ_BY_TYPE_RESPONSE;
943             send_gatt_read_by_type_request(gatt_client);
944             return 1;
945 
946         case P_W2_SEND_READ_MULTIPLE_REQUEST:
947             gatt_client->gatt_client_state = P_W4_READ_MULTIPLE_RESPONSE;
948             send_gatt_read_multiple_request(gatt_client);
949             return 1;
950 
951         case P_W2_SEND_WRITE_CHARACTERISTIC_VALUE:
952             gatt_client->gatt_client_state = P_W4_WRITE_CHARACTERISTIC_VALUE_RESULT;
953             send_gatt_write_attribute_value_request(gatt_client);
954             return 1;
955 
956         case P_W2_PREPARE_WRITE:
957             gatt_client->gatt_client_state = P_W4_PREPARE_WRITE_RESULT;
958             send_gatt_prepare_write_request(gatt_client);
959             return 1;
960 
961         case P_W2_PREPARE_WRITE_SINGLE:
962             gatt_client->gatt_client_state = P_W4_PREPARE_WRITE_SINGLE_RESULT;
963             send_gatt_prepare_write_request(gatt_client);
964             return 1;
965 
966         case P_W2_PREPARE_RELIABLE_WRITE:
967             gatt_client->gatt_client_state = P_W4_PREPARE_RELIABLE_WRITE_RESULT;
968             send_gatt_prepare_write_request(gatt_client);
969             return 1;
970 
971         case P_W2_EXECUTE_PREPARED_WRITE:
972             gatt_client->gatt_client_state = P_W4_EXECUTE_PREPARED_WRITE_RESULT;
973             send_gatt_execute_write_request(gatt_client);
974             return 1;
975 
976         case P_W2_CANCEL_PREPARED_WRITE:
977             gatt_client->gatt_client_state = P_W4_CANCEL_PREPARED_WRITE_RESULT;
978             send_gatt_cancel_prepared_write_request(gatt_client);
979             return 1;
980 
981         case P_W2_CANCEL_PREPARED_WRITE_DATA_MISMATCH:
982             gatt_client->gatt_client_state = P_W4_CANCEL_PREPARED_WRITE_DATA_MISMATCH_RESULT;
983             send_gatt_cancel_prepared_write_request(gatt_client);
984             return 1;
985 
986 #ifdef ENABLE_GATT_FIND_INFORMATION_FOR_CCC_DISCOVERY
987         case P_W2_SEND_FIND_CLIENT_CHARACTERISTIC_CONFIGURATION_QUERY:
988             // use Find Information
989             gatt_client->gatt_client_state = P_W4_FIND_CLIENT_CHARACTERISTIC_CONFIGURATION_QUERY_RESULT;
990             send_gatt_characteristic_descriptor_request(gatt_client);
991 #else
992         case P_W2_SEND_READ_CLIENT_CHARACTERISTIC_CONFIGURATION_QUERY:
993             // Use Read By Type
994             gatt_client->gatt_client_state = P_W4_READ_CLIENT_CHARACTERISTIC_CONFIGURATION_QUERY_RESULT;
995             send_gatt_read_client_characteristic_configuration_request(gatt_client);
996 #endif
997             return 1;
998 
999         case P_W2_SEND_READ_CHARACTERISTIC_DESCRIPTOR_QUERY:
1000             gatt_client->gatt_client_state = P_W4_READ_CHARACTERISTIC_DESCRIPTOR_RESULT;
1001             send_gatt_read_characteristic_descriptor_request(gatt_client);
1002             return 1;
1003 
1004         case P_W2_SEND_READ_BLOB_CHARACTERISTIC_DESCRIPTOR_QUERY:
1005             gatt_client->gatt_client_state = P_W4_READ_BLOB_CHARACTERISTIC_DESCRIPTOR_RESULT;
1006             send_gatt_read_blob_request(gatt_client);
1007             return 1;
1008 
1009         case P_W2_SEND_WRITE_CHARACTERISTIC_DESCRIPTOR:
1010             gatt_client->gatt_client_state = P_W4_WRITE_CHARACTERISTIC_DESCRIPTOR_RESULT;
1011             send_gatt_write_attribute_value_request(gatt_client);
1012             return 1;
1013 
1014         case P_W2_WRITE_CLIENT_CHARACTERISTIC_CONFIGURATION:
1015             gatt_client->gatt_client_state = P_W4_CLIENT_CHARACTERISTIC_CONFIGURATION_RESULT;
1016             send_gatt_write_client_characteristic_configuration_request(gatt_client);
1017             return 1;
1018 
1019         case P_W2_PREPARE_WRITE_CHARACTERISTIC_DESCRIPTOR:
1020             gatt_client->gatt_client_state = P_W4_PREPARE_WRITE_CHARACTERISTIC_DESCRIPTOR_RESULT;
1021             send_gatt_prepare_write_request(gatt_client);
1022             return 1;
1023 
1024         case P_W2_EXECUTE_PREPARED_WRITE_CHARACTERISTIC_DESCRIPTOR:
1025             gatt_client->gatt_client_state = P_W4_EXECUTE_PREPARED_WRITE_CHARACTERISTIC_DESCRIPTOR_RESULT;
1026             send_gatt_execute_write_request(gatt_client);
1027             return 1;
1028 
1029 #ifdef ENABLE_LE_SIGNED_WRITE
1030         case P_W4_IDENTITY_RESOLVING:
1031             log_info("P_W4_IDENTITY_RESOLVING - state %x", sm_identity_resolving_state(gatt_client->con_handle));
1032             switch (sm_identity_resolving_state(gatt_client->con_handle)){
1033                 case IRK_LOOKUP_SUCCEEDED:
1034                     gatt_client->le_device_index = sm_le_device_index(gatt_client->con_handle);
1035                     gatt_client->gatt_client_state = P_W4_CMAC_READY;
1036                     break;
1037                 case IRK_LOOKUP_FAILED:
1038                     gatt_client_handle_transaction_complete(gatt_client);
1039                     emit_gatt_complete_event(gatt_client, ATT_ERROR_BONDING_INFORMATION_MISSING);
1040                     return 0;
1041                 default:
1042                     return 0;
1043             }
1044 
1045             /* Fall through */
1046 
1047         case P_W4_CMAC_READY:
1048             if (sm_cmac_ready()){
1049                 sm_key_t csrk;
1050                 le_device_db_local_csrk_get(gatt_client->le_device_index, csrk);
1051                 uint32_t sign_counter = le_device_db_local_counter_get(gatt_client->le_device_index);
1052                 gatt_client->gatt_client_state = P_W4_CMAC_RESULT;
1053                 sm_cmac_signed_write_start(csrk, ATT_SIGNED_WRITE_COMMAND, gatt_client->attribute_handle, gatt_client->attribute_length, gatt_client->attribute_value, sign_counter, att_signed_write_handle_cmac_result);
1054             }
1055             return 0;
1056 
1057         case P_W2_SEND_SIGNED_WRITE: {
1058             gatt_client->gatt_client_state = P_W4_SEND_SINGED_WRITE_DONE;
1059             // bump local signing counter
1060             uint32_t sign_counter = le_device_db_local_counter_get(gatt_client->le_device_index);
1061             le_device_db_local_counter_set(gatt_client->le_device_index, sign_counter + 1);
1062             // send signed write command
1063             send_gatt_signed_write_request(gatt_client, sign_counter);
1064             // finally, notifiy client that write is complete
1065             gatt_client_handle_transaction_complete(gatt_client);
1066             emit_gatt_complete_event(gatt_client, ATT_ERROR_SUCCESS);
1067             return 1;
1068         }
1069 #endif
1070         default:
1071             break;
1072     }
1073 
1074     // requested can send snow?
1075     if (gatt_client->write_without_response_callback){
1076         btstack_packet_handler_t packet_handler = gatt_client->write_without_response_callback;
1077         gatt_client->write_without_response_callback = NULL;
1078         uint8_t event[4];
1079         event[0] = GATT_EVENT_CAN_WRITE_WITHOUT_RESPONSE;
1080         event[1] = sizeof(event) - 2u;
1081         little_endian_store_16(event, 2, gatt_client->con_handle);
1082         packet_handler(HCI_EVENT_PACKET, gatt_client->con_handle, event, sizeof(event));
1083         return 1; // to trigger requeueing (even if higher layer didn't sent)
1084     }
1085 
1086     return 0;
1087 }
1088 
1089 static void gatt_client_run(void){
1090     btstack_linked_item_t *it;
1091     for (it = (btstack_linked_item_t *) gatt_client_connections; it != NULL; it = it->next){
1092         gatt_client_t * gatt_client = (gatt_client_t *) it;
1093         if (!att_dispatch_client_can_send_now(gatt_client->con_handle)) {
1094             att_dispatch_client_request_can_send_now_event(gatt_client->con_handle);
1095             return;
1096         }
1097         int packet_sent = gatt_client_run_for_gatt_client(gatt_client);
1098         if (packet_sent){
1099             // request new permission
1100             att_dispatch_client_request_can_send_now_event(gatt_client->con_handle);
1101             // requeue client for fairness and exit
1102             // note: iterator has become invalid
1103             btstack_linked_list_remove(&gatt_client_connections, (btstack_linked_item_t *) gatt_client);
1104             btstack_linked_list_add_tail(&gatt_client_connections, (btstack_linked_item_t *) gatt_client);
1105             return;
1106         }
1107     }
1108 }
1109 
1110 static void gatt_client_report_error_if_pending(gatt_client_t *gatt_client, uint8_t att_error_code) {
1111     if (is_ready(gatt_client) == 1) return;
1112     gatt_client_handle_transaction_complete(gatt_client);
1113     emit_gatt_complete_event(gatt_client, att_error_code);
1114 }
1115 
1116 static void gatt_client_event_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
1117     UNUSED(channel);    // ok: handling own l2cap events
1118     UNUSED(size);       // ok: there is no channel
1119 
1120     if (packet_type != HCI_EVENT_PACKET) return;
1121 
1122     hci_con_handle_t con_handle;
1123     gatt_client_t * gatt_client;
1124     switch (hci_event_packet_get_type(packet)) {
1125         case HCI_EVENT_DISCONNECTION_COMPLETE:
1126             log_info("GATT Client: HCI_EVENT_DISCONNECTION_COMPLETE");
1127             con_handle = little_endian_read_16(packet,3);
1128             gatt_client = gatt_client_get_context_for_handle(con_handle);
1129             if (gatt_client == NULL) break;
1130 
1131             gatt_client_report_error_if_pending(gatt_client, ATT_ERROR_HCI_DISCONNECT_RECEIVED);
1132             gatt_client_timeout_stop(gatt_client);
1133             btstack_linked_list_remove(&gatt_client_connections, (btstack_linked_item_t *) gatt_client);
1134             btstack_memory_gatt_client_free(gatt_client);
1135             break;
1136 
1137 #ifdef ENABLE_GATT_CLIENT_PAIRING
1138         // Pairing complete (with/without bonding=storing of pairing information)
1139         case SM_EVENT_PAIRING_COMPLETE:
1140             con_handle = sm_event_pairing_complete_get_handle(packet);
1141             gatt_client = gatt_client_get_context_for_handle(con_handle);
1142             if (gatt_client == NULL) break;
1143 
1144             if (gatt_client->wait_for_pairing_complete){
1145                 gatt_client->wait_for_pairing_complete = 0;
1146                 if (sm_event_pairing_complete_get_status(packet)){
1147                     log_info("pairing failed, report previous error 0x%x", gatt_client->pending_error_code);
1148                     gatt_client_handle_transaction_complete(gatt_client);
1149                     emit_gatt_complete_event(gatt_client, gatt_client->pending_error_code);
1150                 } else {
1151                     log_info("pairing success, retry operation");
1152                 }
1153             }
1154             break;
1155 #endif
1156 #ifdef ENABLE_LE_SIGNED_WRITE
1157         // Identity Resolving completed (no code, gatt_client_run will continue)
1158         case SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED:
1159         case SM_EVENT_IDENTITY_RESOLVING_FAILED:
1160             break;
1161 #endif
1162 
1163         default:
1164             break;
1165     }
1166 
1167     gatt_client_run();
1168 }
1169 
1170 static void gatt_client_att_packet_handler(uint8_t packet_type, uint16_t handle, uint8_t *packet, uint16_t size){
1171     gatt_client_t * gatt_client;
1172     if (size < 1u) return;
1173 
1174     if (packet_type == HCI_EVENT_PACKET) {
1175         switch (packet[0]){
1176             case L2CAP_EVENT_CAN_SEND_NOW:
1177                 gatt_client_run();
1178                 break;
1179             // att_server has negotiated the mtu for this connection, cache if context exists
1180             case ATT_EVENT_MTU_EXCHANGE_COMPLETE:
1181                 if (size < 6u) break;
1182                 gatt_client = gatt_client_get_context_for_handle(handle);
1183                 if (gatt_client == NULL) break;
1184                 gatt_client->mtu = little_endian_read_16(packet, 4);
1185                 break;
1186             default:
1187                 break;
1188         }
1189         return;
1190     }
1191 
1192     if (packet_type != ATT_DATA_PACKET) return;
1193 
1194     // special cases: notifications don't need a context while indications motivate creating one
1195     switch (packet[0]){
1196         case ATT_HANDLE_VALUE_NOTIFICATION:
1197             if (size < 3u) return;
1198             report_gatt_notification(handle, little_endian_read_16(packet,1u), &packet[3], size-3u);
1199             return;
1200         case ATT_HANDLE_VALUE_INDICATION:
1201             gatt_client = gatt_client_provide_context_for_handle(handle);
1202             break;
1203         default:
1204             gatt_client = gatt_client_get_context_for_handle(handle);
1205             break;
1206     }
1207 
1208     if (gatt_client == NULL) return;
1209 
1210     switch (packet[0]){
1211         case ATT_EXCHANGE_MTU_RESPONSE:
1212         {
1213             if (size < 3u) break;
1214             uint16_t remote_rx_mtu = little_endian_read_16(packet, 1);
1215             uint16_t local_rx_mtu = l2cap_max_le_mtu();
1216             gatt_client->mtu = (remote_rx_mtu < local_rx_mtu) ? remote_rx_mtu : local_rx_mtu;
1217             gatt_client->mtu_state = MTU_EXCHANGED;
1218             emit_gatt_mtu_exchanged_result_event(gatt_client, gatt_client->mtu);
1219             break;
1220         }
1221         case ATT_READ_BY_GROUP_TYPE_RESPONSE:
1222             switch(gatt_client->gatt_client_state){
1223                 case P_W4_SERVICE_QUERY_RESULT:
1224                     report_gatt_services(gatt_client, packet, size);
1225                     trigger_next_service_query(gatt_client, get_last_result_handle_from_service_list(packet, size));
1226                     // GATT_EVENT_QUERY_COMPLETE is emitted by trigger_next_xxx when done
1227                     break;
1228                 default:
1229                     break;
1230             }
1231             break;
1232         case ATT_HANDLE_VALUE_INDICATION:
1233             if (size < 3u) break;
1234             report_gatt_indication(handle, little_endian_read_16(packet,1u), &packet[3], size-3u);
1235             gatt_client->send_confirmation = 1;
1236             break;
1237 
1238         case ATT_READ_BY_TYPE_RESPONSE:
1239             switch (gatt_client->gatt_client_state){
1240                 case P_W4_ALL_CHARACTERISTICS_OF_SERVICE_QUERY_RESULT:
1241                     report_gatt_characteristics(gatt_client, packet, size);
1242                     trigger_next_characteristic_query(gatt_client, get_last_result_handle_from_characteristics_list(packet, size));
1243                     // GATT_EVENT_QUERY_COMPLETE is emitted by trigger_next_xxx when done, or by ATT_ERROR
1244                     break;
1245                 case P_W4_CHARACTERISTIC_WITH_UUID_QUERY_RESULT:
1246                     report_gatt_characteristics(gatt_client, packet, size);
1247                     trigger_next_characteristic_query(gatt_client, get_last_result_handle_from_characteristics_list(packet, size));
1248                     // GATT_EVENT_QUERY_COMPLETE is emitted by trigger_next_xxx when done, or by ATT_ERROR
1249                     break;
1250                 case P_W4_INCLUDED_SERVICE_QUERY_RESULT:
1251                 {
1252                     if (size < 2u) break;
1253                     uint16_t uuid16 = 0;
1254                     uint16_t pair_size = packet[1];
1255 
1256                     if (pair_size == 6u){
1257                         if (size < 8u) break;
1258                         // UUIDs not available, query first included service
1259                         gatt_client->start_group_handle = little_endian_read_16(packet, 2); // ready for next query
1260                         gatt_client->query_start_handle = little_endian_read_16(packet, 4);
1261                         gatt_client->query_end_handle = little_endian_read_16(packet, 6);
1262                         gatt_client->gatt_client_state = P_W2_SEND_INCLUDED_SERVICE_WITH_UUID_QUERY;
1263                         break;
1264                     }
1265 
1266                     if (pair_size != 8u) break;
1267 
1268                     // UUIDs included, report all of them
1269                     uint16_t offset;
1270                     for (offset = 2u; (offset + 8u) <= size; offset += pair_size){
1271                         uint16_t include_handle = little_endian_read_16(packet, offset);
1272                         gatt_client->query_start_handle = little_endian_read_16(packet, offset + 2u);
1273                         gatt_client->query_end_handle = little_endian_read_16(packet, offset + 4u);
1274                         uuid16 = little_endian_read_16(packet, offset+6u);
1275                         report_gatt_included_service_uuid16(gatt_client, include_handle, uuid16);
1276                     }
1277 
1278                     trigger_next_included_service_query(gatt_client, get_last_result_handle_from_included_services_list(packet, size));
1279                     // GATT_EVENT_QUERY_COMPLETE is emitted by trigger_next_xxx when done
1280                     break;
1281                 }
1282 #ifndef ENABLE_GATT_FIND_INFORMATION_FOR_CCC_DISCOVERY
1283                 case P_W4_READ_CLIENT_CHARACTERISTIC_CONFIGURATION_QUERY_RESULT:
1284                     gatt_client->client_characteristic_configuration_handle = little_endian_read_16(packet, 2);
1285                     gatt_client->gatt_client_state = P_W2_WRITE_CLIENT_CHARACTERISTIC_CONFIGURATION;
1286                     break;
1287 #endif
1288                 case P_W4_READ_BY_TYPE_RESPONSE: {
1289                     uint16_t pair_size = packet[1];
1290                     uint16_t offset;
1291                     uint16_t last_result_handle = 0;
1292                     for (offset = 2; offset < size ; offset += pair_size){
1293                         uint16_t value_handle = little_endian_read_16(packet, offset);
1294                         report_gatt_characteristic_value(gatt_client, value_handle, &packet[offset + 2u], pair_size - 2u);
1295                         last_result_handle = value_handle;
1296                     }
1297                     trigger_next_read_by_type_query(gatt_client, last_result_handle);
1298                     break;
1299                 }
1300                 default:
1301                     break;
1302             }
1303             break;
1304         case ATT_READ_RESPONSE:
1305             switch (gatt_client->gatt_client_state){
1306                 case P_W4_INCLUDED_SERVICE_UUID_WITH_QUERY_RESULT: {
1307                     uint8_t uuid128[16];
1308                     reverse_128(&packet[1], uuid128);
1309                     report_gatt_included_service_uuid128(gatt_client, gatt_client->start_group_handle, uuid128);
1310                     trigger_next_included_service_query(gatt_client, gatt_client->start_group_handle);
1311                     // GATT_EVENT_QUERY_COMPLETE is emitted by trigger_next_xxx when done
1312                     break;
1313                 }
1314                 case P_W4_READ_CHARACTERISTIC_VALUE_RESULT:
1315                     gatt_client_handle_transaction_complete(gatt_client);
1316                     report_gatt_characteristic_value(gatt_client, gatt_client->attribute_handle, &packet[1], size - 1u);
1317                     emit_gatt_complete_event(gatt_client, ATT_ERROR_SUCCESS);
1318                     break;
1319 
1320                 case P_W4_READ_CHARACTERISTIC_DESCRIPTOR_RESULT:{
1321                     gatt_client_handle_transaction_complete(gatt_client);
1322                     report_gatt_characteristic_descriptor(gatt_client, gatt_client->attribute_handle, &packet[1], size - 1u, 0u);
1323                     emit_gatt_complete_event(gatt_client, ATT_ERROR_SUCCESS);
1324                     break;
1325                 }
1326                 default:
1327                     break;
1328             }
1329             break;
1330 
1331         case ATT_FIND_BY_TYPE_VALUE_RESPONSE:
1332         {
1333             uint8_t pair_size = 4;
1334             int i;
1335             uint16_t start_group_handle;
1336             uint16_t   end_group_handle= 0xffff; // asserts GATT_EVENT_QUERY_COMPLETE is emitted if no results
1337             for (i = 1u; (i + pair_size) <= size; i += pair_size){
1338                 start_group_handle = little_endian_read_16(packet,i);
1339                 end_group_handle = little_endian_read_16(packet,i+2);
1340                 emit_gatt_service_query_result_event(gatt_client, start_group_handle, end_group_handle, gatt_client->uuid128);
1341             }
1342             trigger_next_service_by_uuid_query(gatt_client, end_group_handle);
1343             // GATT_EVENT_QUERY_COMPLETE is emitted by trigger_next_xxx when done
1344             break;
1345         }
1346         case ATT_FIND_INFORMATION_REPLY:
1347         {
1348             if (size < 2u) break;
1349 
1350             uint8_t pair_size = 4;
1351             if (packet[1u] == 2u){
1352                 pair_size = 18;
1353             }
1354             uint16_t offset = 2;
1355 
1356             if (size < (pair_size + offset)) break;
1357             uint16_t last_descriptor_handle = little_endian_read_16(packet, size - pair_size);
1358 
1359 #ifdef ENABLE_GATT_FIND_INFORMATION_FOR_CCC_DISCOVERY
1360             log_info("ENABLE_GATT_FIND_INFORMATION_FOR_CCC_DISCOVERY, state %x", gatt_client->gatt_client_state);
1361             if (gatt_client->gatt_client_state == P_W4_FIND_CLIENT_CHARACTERISTIC_CONFIGURATION_QUERY_RESULT){
1362                 // iterate over descriptors looking for CCC
1363                 if (pair_size == 4){
1364                     while ((offset + 4) <= size){
1365                         uint16_t uuid16 = little_endian_read_16(packet, offset + 2);
1366                         if (uuid16 == GATT_CLIENT_CHARACTERISTICS_CONFIGURATION){
1367                             gatt_client->client_characteristic_configuration_handle = little_endian_read_16(packet, offset);
1368                             gatt_client->gatt_client_state = P_W2_WRITE_CLIENT_CHARACTERISTIC_CONFIGURATION;
1369                             log_info("CCC found %x", gatt_client->client_characteristic_configuration_handle);
1370                             break;
1371                         }
1372                         offset += pair_size;
1373                     }
1374                 }
1375                 if (is_query_done(gatt_client, last_descriptor_handle)){
1376 
1377                 } else {
1378                     // next
1379                     gatt_client->start_group_handle = last_descriptor_handle + 1;
1380                     gatt_client->gatt_client_state = P_W2_SEND_FIND_CLIENT_CHARACTERISTIC_CONFIGURATION_QUERY;
1381                 }
1382                 break;
1383             }
1384 #endif
1385             report_gatt_all_characteristic_descriptors(gatt_client, &packet[2], size - 2u, pair_size);
1386             trigger_next_characteristic_descriptor_query(gatt_client, last_descriptor_handle);
1387             // GATT_EVENT_QUERY_COMPLETE is emitted by trigger_next_xxx when done
1388             break;
1389         }
1390 
1391         case ATT_WRITE_RESPONSE:
1392             switch (gatt_client->gatt_client_state){
1393                 case P_W4_WRITE_CHARACTERISTIC_VALUE_RESULT:
1394                     gatt_client_handle_transaction_complete(gatt_client);
1395                     emit_gatt_complete_event(gatt_client, ATT_ERROR_SUCCESS);
1396                     break;
1397                 case P_W4_CLIENT_CHARACTERISTIC_CONFIGURATION_RESULT:
1398                     gatt_client_handle_transaction_complete(gatt_client);
1399                     emit_gatt_complete_event(gatt_client, ATT_ERROR_SUCCESS);
1400                     break;
1401                 case P_W4_WRITE_CHARACTERISTIC_DESCRIPTOR_RESULT:
1402                     gatt_client_handle_transaction_complete(gatt_client);
1403                     emit_gatt_complete_event(gatt_client, ATT_ERROR_SUCCESS);
1404                     break;
1405                 default:
1406                     break;
1407             }
1408             break;
1409 
1410         case ATT_READ_BLOB_RESPONSE:{
1411             uint16_t received_blob_length = size-1u;
1412             switch(gatt_client->gatt_client_state){
1413                 case P_W4_READ_BLOB_RESULT:
1414                     report_gatt_long_characteristic_value_blob(gatt_client, gatt_client->attribute_handle, &packet[1], received_blob_length, gatt_client->attribute_offset);
1415                     trigger_next_blob_query(gatt_client, P_W2_SEND_READ_BLOB_QUERY, received_blob_length);
1416                     // GATT_EVENT_QUERY_COMPLETE is emitted by trigger_next_xxx when done
1417                     break;
1418                 case P_W4_READ_BLOB_CHARACTERISTIC_DESCRIPTOR_RESULT:
1419                     report_gatt_long_characteristic_descriptor(gatt_client, gatt_client->attribute_handle,
1420                                                                &packet[1], received_blob_length,
1421                                                                gatt_client->attribute_offset);
1422                     trigger_next_blob_query(gatt_client, P_W2_SEND_READ_BLOB_CHARACTERISTIC_DESCRIPTOR_QUERY, received_blob_length);
1423                     // GATT_EVENT_QUERY_COMPLETE is emitted by trigger_next_xxx when done
1424                     break;
1425                 default:
1426                     break;
1427             }
1428             break;
1429         }
1430         case ATT_PREPARE_WRITE_RESPONSE:
1431             switch (gatt_client->gatt_client_state){
1432                 case P_W4_PREPARE_WRITE_SINGLE_RESULT:
1433                     gatt_client_handle_transaction_complete(gatt_client);
1434                     if (is_value_valid(gatt_client, packet, size)){
1435                         emit_gatt_complete_event(gatt_client, ATT_ERROR_SUCCESS);
1436                     } else {
1437                         emit_gatt_complete_event(gatt_client, ATT_ERROR_DATA_MISMATCH);
1438                     }
1439                     break;
1440 
1441                 case P_W4_PREPARE_WRITE_RESULT:{
1442                     gatt_client->attribute_offset = little_endian_read_16(packet, 3);
1443                     trigger_next_prepare_write_query(gatt_client, P_W2_PREPARE_WRITE, P_W2_EXECUTE_PREPARED_WRITE);
1444                     // GATT_EVENT_QUERY_COMPLETE is emitted by trigger_next_xxx when done
1445                     break;
1446                 }
1447                 case P_W4_PREPARE_WRITE_CHARACTERISTIC_DESCRIPTOR_RESULT:{
1448                     gatt_client->attribute_offset = little_endian_read_16(packet, 3);
1449                     trigger_next_prepare_write_query(gatt_client, P_W2_PREPARE_WRITE_CHARACTERISTIC_DESCRIPTOR, P_W2_EXECUTE_PREPARED_WRITE_CHARACTERISTIC_DESCRIPTOR);
1450                     // GATT_EVENT_QUERY_COMPLETE is emitted by trigger_next_xxx when done
1451                     break;
1452                 }
1453                 case P_W4_PREPARE_RELIABLE_WRITE_RESULT:{
1454                     if (is_value_valid(gatt_client, packet, size)){
1455                         gatt_client->attribute_offset = little_endian_read_16(packet, 3);
1456                         trigger_next_prepare_write_query(gatt_client, P_W2_PREPARE_RELIABLE_WRITE, P_W2_EXECUTE_PREPARED_WRITE);
1457                         // GATT_EVENT_QUERY_COMPLETE is emitted by trigger_next_xxx when done
1458                         break;
1459                     }
1460                     gatt_client->gatt_client_state = P_W2_CANCEL_PREPARED_WRITE_DATA_MISMATCH;
1461                     break;
1462                 }
1463                 default:
1464                     break;
1465             }
1466             break;
1467 
1468         case ATT_EXECUTE_WRITE_RESPONSE:
1469             switch (gatt_client->gatt_client_state){
1470                 case P_W4_EXECUTE_PREPARED_WRITE_RESULT:
1471                     gatt_client_handle_transaction_complete(gatt_client);
1472                     emit_gatt_complete_event(gatt_client, ATT_ERROR_SUCCESS);
1473                     break;
1474                 case P_W4_CANCEL_PREPARED_WRITE_RESULT:
1475                     gatt_client_handle_transaction_complete(gatt_client);
1476                     emit_gatt_complete_event(gatt_client, ATT_ERROR_SUCCESS);
1477                     break;
1478                 case P_W4_CANCEL_PREPARED_WRITE_DATA_MISMATCH_RESULT:
1479                     gatt_client_handle_transaction_complete(gatt_client);
1480                     emit_gatt_complete_event(gatt_client, ATT_ERROR_DATA_MISMATCH);
1481                     break;
1482                 case P_W4_EXECUTE_PREPARED_WRITE_CHARACTERISTIC_DESCRIPTOR_RESULT:
1483                     gatt_client_handle_transaction_complete(gatt_client);
1484                     emit_gatt_complete_event(gatt_client, ATT_ERROR_SUCCESS);
1485                     break;
1486                 default:
1487                     break;
1488 
1489             }
1490             break;
1491 
1492         case ATT_READ_MULTIPLE_RESPONSE:
1493             switch(gatt_client->gatt_client_state){
1494                 case P_W4_READ_MULTIPLE_RESPONSE:
1495                     report_gatt_characteristic_value(gatt_client, 0u, &packet[1], size - 1u);
1496                     gatt_client_handle_transaction_complete(gatt_client);
1497                     emit_gatt_complete_event(gatt_client, ATT_ERROR_SUCCESS);
1498                     break;
1499                 default:
1500                     break;
1501             }
1502             break;
1503 
1504         case ATT_ERROR_RESPONSE:
1505             if (size < 5u) return;
1506             switch (packet[4]){
1507                 case ATT_ERROR_ATTRIBUTE_NOT_FOUND: {
1508                     switch(gatt_client->gatt_client_state){
1509                         case P_W4_SERVICE_QUERY_RESULT:
1510                         case P_W4_SERVICE_WITH_UUID_RESULT:
1511                         case P_W4_INCLUDED_SERVICE_QUERY_RESULT:
1512                         case P_W4_ALL_CHARACTERISTIC_DESCRIPTORS_QUERY_RESULT:
1513                             gatt_client_handle_transaction_complete(gatt_client);
1514                             emit_gatt_complete_event(gatt_client, ATT_ERROR_SUCCESS);
1515                             break;
1516                         case P_W4_ALL_CHARACTERISTICS_OF_SERVICE_QUERY_RESULT:
1517                         case P_W4_CHARACTERISTIC_WITH_UUID_QUERY_RESULT:
1518                             characteristic_end_found(gatt_client, gatt_client->end_group_handle);
1519                             gatt_client_handle_transaction_complete(gatt_client);
1520                             emit_gatt_complete_event(gatt_client, ATT_ERROR_SUCCESS);
1521                             break;
1522                         case P_W4_READ_BY_TYPE_RESPONSE:
1523                             gatt_client_handle_transaction_complete(gatt_client);
1524                             if (gatt_client->start_group_handle == gatt_client->query_start_handle){
1525                                 emit_gatt_complete_event(gatt_client, ATT_ERROR_ATTRIBUTE_NOT_FOUND);
1526                             } else {
1527                                 emit_gatt_complete_event(gatt_client, ATT_ERROR_SUCCESS);
1528                             }
1529                             break;
1530                         default:
1531                             gatt_client_report_error_if_pending(gatt_client, packet[4]);
1532                             break;
1533                     }
1534                     break;
1535                 }
1536 
1537 #ifdef ENABLE_GATT_CLIENT_PAIRING
1538 
1539                 case ATT_ERROR_INSUFFICIENT_AUTHENTICATION:
1540                 case ATT_ERROR_INSUFFICIENT_ENCRYPTION_KEY_SIZE:
1541                 case ATT_ERROR_INSUFFICIENT_ENCRYPTION: {
1542 
1543                     // security too low
1544                     if (gatt_client->security_counter > 0) {
1545                         gatt_client_report_error_if_pending(gatt_client, packet[4]);
1546                         break;
1547                     }
1548                     // start security
1549                     gatt_client->security_counter++;
1550 
1551                     // setup action
1552                     int retry = 1;
1553                     switch (gatt_client->gatt_client_state){
1554                         case P_W4_READ_CHARACTERISTIC_VALUE_RESULT:
1555                             gatt_client->gatt_client_state = P_W2_SEND_READ_CHARACTERISTIC_VALUE_QUERY ;
1556                             break;
1557                         case P_W4_READ_BLOB_RESULT:
1558                             gatt_client->gatt_client_state = P_W2_SEND_READ_BLOB_QUERY;
1559                             break;
1560                         case P_W4_READ_BY_TYPE_RESPONSE:
1561                             gatt_client->gatt_client_state = P_W2_SEND_READ_BY_TYPE_REQUEST;
1562                             break;
1563                         case P_W4_READ_MULTIPLE_RESPONSE:
1564                             gatt_client->gatt_client_state = P_W2_SEND_READ_MULTIPLE_REQUEST;
1565                             break;
1566                         case P_W4_WRITE_CHARACTERISTIC_VALUE_RESULT:
1567                             gatt_client->gatt_client_state = P_W2_SEND_WRITE_CHARACTERISTIC_VALUE;
1568                             break;
1569                         case P_W4_PREPARE_WRITE_RESULT:
1570                             gatt_client->gatt_client_state = P_W2_PREPARE_WRITE;
1571                             break;
1572                         case P_W4_PREPARE_WRITE_SINGLE_RESULT:
1573                             gatt_client->gatt_client_state = P_W2_PREPARE_WRITE_SINGLE;
1574                             break;
1575                         case P_W4_PREPARE_RELIABLE_WRITE_RESULT:
1576                             gatt_client->gatt_client_state = P_W2_PREPARE_RELIABLE_WRITE;
1577                             break;
1578                         case P_W4_EXECUTE_PREPARED_WRITE_RESULT:
1579                             gatt_client->gatt_client_state = P_W2_EXECUTE_PREPARED_WRITE;
1580                             break;
1581                         case P_W4_CANCEL_PREPARED_WRITE_RESULT:
1582                             gatt_client->gatt_client_state = P_W2_CANCEL_PREPARED_WRITE;
1583                             break;
1584                         case P_W4_CANCEL_PREPARED_WRITE_DATA_MISMATCH_RESULT:
1585                             gatt_client->gatt_client_state = P_W2_CANCEL_PREPARED_WRITE_DATA_MISMATCH;
1586                             break;
1587                         case P_W4_READ_CHARACTERISTIC_DESCRIPTOR_RESULT:
1588                             gatt_client->gatt_client_state = P_W2_SEND_READ_CHARACTERISTIC_DESCRIPTOR_QUERY;
1589                             break;
1590                         case P_W4_READ_BLOB_CHARACTERISTIC_DESCRIPTOR_RESULT:
1591                             gatt_client->gatt_client_state = P_W2_SEND_READ_BLOB_CHARACTERISTIC_DESCRIPTOR_QUERY;
1592                             break;
1593                         case P_W4_WRITE_CHARACTERISTIC_DESCRIPTOR_RESULT:
1594                             gatt_client->gatt_client_state = P_W2_SEND_WRITE_CHARACTERISTIC_DESCRIPTOR;
1595                             break;
1596                         case P_W4_CLIENT_CHARACTERISTIC_CONFIGURATION_RESULT:
1597                             gatt_client->gatt_client_state = P_W2_WRITE_CLIENT_CHARACTERISTIC_CONFIGURATION;
1598                             break;
1599                         case P_W4_PREPARE_WRITE_CHARACTERISTIC_DESCRIPTOR_RESULT:
1600                             gatt_client->gatt_client_state = P_W2_PREPARE_WRITE_CHARACTERISTIC_DESCRIPTOR;
1601                             break;
1602                         case P_W4_EXECUTE_PREPARED_WRITE_CHARACTERISTIC_DESCRIPTOR_RESULT:
1603                             gatt_client->gatt_client_state = P_W2_EXECUTE_PREPARED_WRITE_CHARACTERISTIC_DESCRIPTOR;
1604                             break;
1605 #ifdef ENABLE_LE_SIGNED_WRITE
1606                         case P_W4_SEND_SINGED_WRITE_DONE:
1607                             gatt_client->gatt_client_state = P_W2_SEND_SIGNED_WRITE;
1608                             break;
1609 #endif
1610                         default:
1611                             log_info("retry not supported for state %x", gatt_client->gatt_client_state);
1612                             retry = 0;
1613                             break;
1614                     }
1615 
1616                     if (!retry) {
1617                         gatt_client_report_error_if_pending(gatt_client, packet[4]);
1618                         break;
1619                     }
1620 
1621                     log_info("security error, start pairing");
1622 
1623                     // requrest pairing
1624                     gatt_client->wait_for_pairing_complete = 1;
1625                     gatt_client->pending_error_code = packet[4];
1626                     sm_request_pairing(gatt_client->con_handle);
1627                     break;
1628                 }
1629 #endif
1630 
1631                 // nothing we can do about that
1632                 case ATT_ERROR_INSUFFICIENT_AUTHORIZATION:
1633                 default:
1634                     gatt_client_report_error_if_pending(gatt_client, packet[4]);
1635                     break;
1636             }
1637             break;
1638 
1639         default:
1640             log_info("ATT Handler, unhandled response type 0x%02x", packet[0]);
1641             break;
1642     }
1643     gatt_client_run();
1644 }
1645 
1646 #ifdef ENABLE_LE_SIGNED_WRITE
1647 static void att_signed_write_handle_cmac_result(uint8_t hash[8]){
1648     btstack_linked_list_iterator_t it;
1649     btstack_linked_list_iterator_init(&it, &gatt_client_connections);
1650     while (btstack_linked_list_iterator_has_next(&it)){
1651         gatt_client_t * gatt_client = (gatt_client_t *) btstack_linked_list_iterator_next(&it);
1652         if (gatt_client->gatt_client_state == P_W4_CMAC_RESULT){
1653             // store result
1654             (void)memcpy(gatt_client->cmac, hash, 8);
1655             // reverse_64(hash, gatt_client->cmac);
1656             gatt_client->gatt_client_state = P_W2_SEND_SIGNED_WRITE;
1657             gatt_client_run();
1658             return;
1659         }
1660     }
1661 }
1662 
1663 uint8_t gatt_client_signed_write_without_response(btstack_packet_handler_t callback, hci_con_handle_t con_handle, uint16_t handle, uint16_t message_len, uint8_t * message){
1664     gatt_client_t * gatt_client = gatt_client_provide_context_for_handle(con_handle);
1665     if (gatt_client == NULL) return BTSTACK_MEMORY_ALLOC_FAILED;
1666     if (is_ready(gatt_client) == 0) return GATT_CLIENT_IN_WRONG_STATE;
1667 
1668     gatt_client->callback = callback;
1669     gatt_client->attribute_handle = handle;
1670     gatt_client->attribute_length = message_len;
1671     gatt_client->attribute_value = message;
1672     gatt_client->gatt_client_state = P_W4_IDENTITY_RESOLVING;
1673     gatt_client_run();
1674     return ERROR_CODE_SUCCESS;
1675 }
1676 #endif
1677 
1678 uint8_t gatt_client_discover_primary_services(btstack_packet_handler_t callback, hci_con_handle_t con_handle){
1679     gatt_client_t * gatt_client = gatt_client_provide_context_for_handle_and_start_timer(con_handle);
1680     if (gatt_client == NULL) return BTSTACK_MEMORY_ALLOC_FAILED;
1681     if (is_ready(gatt_client) == 0) return GATT_CLIENT_IN_WRONG_STATE;
1682 
1683     gatt_client->callback = callback;
1684     gatt_client->start_group_handle = 0x0001;
1685     gatt_client->end_group_handle   = 0xffff;
1686     gatt_client->gatt_client_state = P_W2_SEND_SERVICE_QUERY;
1687     gatt_client->uuid16 = 0;
1688     gatt_client_run();
1689     return ERROR_CODE_SUCCESS;
1690 }
1691 
1692 
1693 uint8_t gatt_client_discover_primary_services_by_uuid16(btstack_packet_handler_t callback, hci_con_handle_t con_handle, uint16_t uuid16){
1694     gatt_client_t * gatt_client = gatt_client_provide_context_for_handle_and_start_timer(con_handle);
1695     if (gatt_client == NULL) return BTSTACK_MEMORY_ALLOC_FAILED;
1696     if (is_ready(gatt_client) == 0) return GATT_CLIENT_IN_WRONG_STATE;
1697 
1698     gatt_client->callback = callback;
1699     gatt_client->start_group_handle = 0x0001;
1700     gatt_client->end_group_handle   = 0xffff;
1701     gatt_client->gatt_client_state = P_W2_SEND_SERVICE_WITH_UUID_QUERY;
1702     gatt_client->uuid16 = uuid16;
1703     uuid_add_bluetooth_prefix((uint8_t*) &(gatt_client->uuid128), gatt_client->uuid16);
1704     gatt_client_run();
1705     return ERROR_CODE_SUCCESS;
1706 }
1707 
1708 uint8_t gatt_client_discover_primary_services_by_uuid128(btstack_packet_handler_t callback, hci_con_handle_t con_handle, const uint8_t * uuid128){
1709     gatt_client_t * gatt_client = gatt_client_provide_context_for_handle_and_start_timer(con_handle);
1710     if (gatt_client == NULL) return BTSTACK_MEMORY_ALLOC_FAILED;
1711     if (is_ready(gatt_client) == 0) return GATT_CLIENT_IN_WRONG_STATE;
1712 
1713     gatt_client->callback = callback;
1714     gatt_client->start_group_handle = 0x0001;
1715     gatt_client->end_group_handle   = 0xffff;
1716     gatt_client->uuid16 = 0;
1717     (void)memcpy(gatt_client->uuid128, uuid128, 16);
1718     gatt_client->gatt_client_state = P_W2_SEND_SERVICE_WITH_UUID_QUERY;
1719     gatt_client_run();
1720     return ERROR_CODE_SUCCESS;
1721 }
1722 
1723 uint8_t gatt_client_discover_characteristics_for_service(btstack_packet_handler_t callback, hci_con_handle_t con_handle, gatt_client_service_t *service){
1724     gatt_client_t * gatt_client = gatt_client_provide_context_for_handle_and_start_timer(con_handle);
1725     if (gatt_client == NULL) return BTSTACK_MEMORY_ALLOC_FAILED;
1726     if (is_ready(gatt_client) == 0) return GATT_CLIENT_IN_WRONG_STATE;
1727 
1728     gatt_client->callback = callback;
1729     gatt_client->start_group_handle = service->start_group_handle;
1730     gatt_client->end_group_handle   = service->end_group_handle;
1731     gatt_client->filter_with_uuid = 0;
1732     gatt_client->characteristic_start_handle = 0;
1733     gatt_client->gatt_client_state = P_W2_SEND_ALL_CHARACTERISTICS_OF_SERVICE_QUERY;
1734     gatt_client_run();
1735     return ERROR_CODE_SUCCESS;
1736 }
1737 
1738 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){
1739     gatt_client_t * gatt_client = gatt_client_provide_context_for_handle_and_start_timer(con_handle);
1740     if (gatt_client == NULL) return BTSTACK_MEMORY_ALLOC_FAILED;
1741     if (is_ready(gatt_client) == 0) return GATT_CLIENT_IN_WRONG_STATE;
1742     gatt_client->callback = callback;
1743     gatt_client->start_group_handle = service->start_group_handle;
1744     gatt_client->end_group_handle   = service->end_group_handle;
1745     gatt_client->gatt_client_state = P_W2_SEND_INCLUDED_SERVICE_QUERY;
1746 
1747     gatt_client_run();
1748     return ERROR_CODE_SUCCESS;
1749 }
1750 
1751 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){
1752     gatt_client_t * gatt_client = gatt_client_provide_context_for_handle_and_start_timer(con_handle);
1753     if (gatt_client == NULL) return BTSTACK_MEMORY_ALLOC_FAILED;
1754     if (is_ready(gatt_client) == 0) return GATT_CLIENT_IN_WRONG_STATE;
1755 
1756     gatt_client->callback = callback;
1757     gatt_client->start_group_handle = start_handle;
1758     gatt_client->end_group_handle   = end_handle;
1759     gatt_client->filter_with_uuid = 1;
1760     gatt_client->uuid16 = uuid16;
1761     uuid_add_bluetooth_prefix((uint8_t*) &(gatt_client->uuid128), uuid16);
1762     gatt_client->characteristic_start_handle = 0;
1763     gatt_client->gatt_client_state = P_W2_SEND_CHARACTERISTIC_WITH_UUID_QUERY;
1764     gatt_client_run();
1765     return ERROR_CODE_SUCCESS;
1766 }
1767 
1768 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, uint8_t * uuid128){
1769     gatt_client_t * gatt_client = gatt_client_provide_context_for_handle_and_start_timer(con_handle);
1770     if (gatt_client == NULL) return BTSTACK_MEMORY_ALLOC_FAILED;
1771     if (is_ready(gatt_client) == 0) return GATT_CLIENT_IN_WRONG_STATE;
1772 
1773     gatt_client->callback = callback;
1774     gatt_client->start_group_handle = start_handle;
1775     gatt_client->end_group_handle   = end_handle;
1776     gatt_client->filter_with_uuid = 1;
1777     gatt_client->uuid16 = 0;
1778     (void)memcpy(gatt_client->uuid128, uuid128, 16);
1779     gatt_client->characteristic_start_handle = 0;
1780     gatt_client->gatt_client_state = P_W2_SEND_CHARACTERISTIC_WITH_UUID_QUERY;
1781     gatt_client_run();
1782     return ERROR_CODE_SUCCESS;
1783 }
1784 
1785 
1786 uint8_t gatt_client_discover_characteristics_for_service_by_uuid16(btstack_packet_handler_t callback, uint16_t handle, gatt_client_service_t *service, uint16_t  uuid16){
1787     return gatt_client_discover_characteristics_for_handle_range_by_uuid16(callback, handle, service->start_group_handle, service->end_group_handle, uuid16);
1788 }
1789 
1790 uint8_t gatt_client_discover_characteristics_for_service_by_uuid128(btstack_packet_handler_t callback, uint16_t handle, gatt_client_service_t *service, uint8_t * uuid128){
1791     return gatt_client_discover_characteristics_for_handle_range_by_uuid128(callback, handle, service->start_group_handle, service->end_group_handle, uuid128);
1792 }
1793 
1794 uint8_t gatt_client_discover_characteristic_descriptors(btstack_packet_handler_t callback, hci_con_handle_t con_handle, gatt_client_characteristic_t *characteristic){
1795     gatt_client_t * gatt_client = gatt_client_provide_context_for_handle_and_start_timer(con_handle);
1796     if (gatt_client == NULL) return BTSTACK_MEMORY_ALLOC_FAILED;
1797     if (is_ready(gatt_client) == 0) return GATT_CLIENT_IN_WRONG_STATE;
1798 
1799     if (characteristic->value_handle == characteristic->end_handle){
1800         emit_gatt_complete_event(gatt_client, ATT_ERROR_SUCCESS);
1801         return ERROR_CODE_SUCCESS;
1802     }
1803     gatt_client->callback = callback;
1804     gatt_client->start_group_handle = characteristic->value_handle + 1u;
1805     gatt_client->end_group_handle   = characteristic->end_handle;
1806     gatt_client->gatt_client_state = P_W2_SEND_ALL_CHARACTERISTIC_DESCRIPTORS_QUERY;
1807     gatt_client_run();
1808     return ERROR_CODE_SUCCESS;
1809 }
1810 
1811 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){
1812     gatt_client_t * gatt_client = gatt_client_provide_context_for_handle_and_start_timer(con_handle);
1813     if (gatt_client == NULL) return BTSTACK_MEMORY_ALLOC_FAILED;
1814     if (is_ready(gatt_client) == 0) return GATT_CLIENT_IN_WRONG_STATE;
1815 
1816     gatt_client->callback = callback;
1817     gatt_client->attribute_handle = value_handle;
1818     gatt_client->attribute_offset = 0;
1819     gatt_client->gatt_client_state = P_W2_SEND_READ_CHARACTERISTIC_VALUE_QUERY;
1820     gatt_client_run();
1821     return ERROR_CODE_SUCCESS;
1822 }
1823 
1824 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){
1825     gatt_client_t * gatt_client = gatt_client_provide_context_for_handle_and_start_timer(con_handle);
1826     if (gatt_client == NULL) return BTSTACK_MEMORY_ALLOC_FAILED;
1827     if (is_ready(gatt_client) == 0) return GATT_CLIENT_IN_WRONG_STATE;
1828 
1829     gatt_client->callback = callback;
1830     gatt_client->start_group_handle = start_handle;
1831     gatt_client->end_group_handle = end_handle;
1832     gatt_client->query_start_handle = start_handle;
1833     gatt_client->query_end_handle = end_handle;
1834     gatt_client->uuid16 = uuid16;
1835     uuid_add_bluetooth_prefix((uint8_t*) &(gatt_client->uuid128), uuid16);
1836     gatt_client->gatt_client_state = P_W2_SEND_READ_BY_TYPE_REQUEST;
1837     gatt_client_run();
1838     return ERROR_CODE_SUCCESS;
1839 }
1840 
1841 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, uint8_t * uuid128){
1842     gatt_client_t * gatt_client = gatt_client_provide_context_for_handle_and_start_timer(con_handle);
1843     if (gatt_client == NULL) return BTSTACK_MEMORY_ALLOC_FAILED;
1844     if (is_ready(gatt_client) == 0) return GATT_CLIENT_IN_WRONG_STATE;
1845 
1846     gatt_client->callback = callback;
1847     gatt_client->start_group_handle = start_handle;
1848     gatt_client->end_group_handle = end_handle;
1849     gatt_client->query_start_handle = start_handle;
1850     gatt_client->query_end_handle = end_handle;
1851     gatt_client->uuid16 = 0;
1852     (void)memcpy(gatt_client->uuid128, uuid128, 16);
1853     gatt_client->gatt_client_state = P_W2_SEND_READ_BY_TYPE_REQUEST;
1854     gatt_client_run();
1855     return ERROR_CODE_SUCCESS;
1856 }
1857 
1858 
1859 uint8_t gatt_client_read_value_of_characteristic(btstack_packet_handler_t callback, uint16_t handle, gatt_client_characteristic_t *characteristic){
1860     return gatt_client_read_value_of_characteristic_using_value_handle(callback, handle, characteristic->value_handle);
1861 }
1862 
1863 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 characteristic_value_handle, uint16_t offset){
1864     gatt_client_t * gatt_client = gatt_client_provide_context_for_handle_and_start_timer(con_handle);
1865     if (gatt_client == NULL) return BTSTACK_MEMORY_ALLOC_FAILED;
1866     if (is_ready(gatt_client) == 0) return GATT_CLIENT_IN_WRONG_STATE;
1867 
1868     gatt_client->callback = callback;
1869     gatt_client->attribute_handle = characteristic_value_handle;
1870     gatt_client->attribute_offset = offset;
1871     gatt_client->gatt_client_state = P_W2_SEND_READ_BLOB_QUERY;
1872     gatt_client_run();
1873     return ERROR_CODE_SUCCESS;
1874 }
1875 
1876 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 characteristic_value_handle){
1877     return gatt_client_read_long_value_of_characteristic_using_value_handle_with_offset(callback, con_handle, characteristic_value_handle, 0);
1878 }
1879 
1880 uint8_t gatt_client_read_long_value_of_characteristic(btstack_packet_handler_t callback, uint16_t handle, gatt_client_characteristic_t *characteristic){
1881     return gatt_client_read_long_value_of_characteristic_using_value_handle(callback, handle, characteristic->value_handle);
1882 }
1883 
1884 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){
1885     gatt_client_t * gatt_client = gatt_client_provide_context_for_handle_and_start_timer(con_handle);
1886     if (gatt_client == NULL) return BTSTACK_MEMORY_ALLOC_FAILED;
1887     if (is_ready(gatt_client) == 0) return GATT_CLIENT_IN_WRONG_STATE;
1888 
1889     gatt_client->callback = callback;
1890     gatt_client->read_multiple_handle_count = num_value_handles;
1891     gatt_client->read_multiple_handles = value_handles;
1892     gatt_client->gatt_client_state = P_W2_SEND_READ_MULTIPLE_REQUEST;
1893     gatt_client_run();
1894     return ERROR_CODE_SUCCESS;
1895 }
1896 
1897 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){
1898     gatt_client_t * gatt_client = gatt_client_provide_context_for_handle(con_handle);
1899     if (gatt_client == NULL) return BTSTACK_MEMORY_ALLOC_FAILED;
1900 
1901     if (value_length > (gatt_client_mtu(gatt_client) - 3u)) return GATT_CLIENT_VALUE_TOO_LONG;
1902     if (!att_dispatch_client_can_send_now(gatt_client->con_handle)) return GATT_CLIENT_BUSY;
1903 
1904     return att_write_request(ATT_WRITE_COMMAND, gatt_client->con_handle, value_handle, value_length, value);
1905 }
1906 
1907 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 * data){
1908     gatt_client_t * gatt_client = gatt_client_provide_context_for_handle_and_start_timer(con_handle);
1909     if (gatt_client == NULL) return BTSTACK_MEMORY_ALLOC_FAILED;
1910     if (is_ready(gatt_client) == 0) return GATT_CLIENT_IN_WRONG_STATE;
1911 
1912     gatt_client->callback = callback;
1913     gatt_client->attribute_handle = value_handle;
1914     gatt_client->attribute_length = value_length;
1915     gatt_client->attribute_value = data;
1916     gatt_client->gatt_client_state = P_W2_SEND_WRITE_CHARACTERISTIC_VALUE;
1917     gatt_client_run();
1918     return ERROR_CODE_SUCCESS;
1919 }
1920 
1921 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  * data){
1922     gatt_client_t * gatt_client = gatt_client_provide_context_for_handle_and_start_timer(con_handle);
1923     if (gatt_client == NULL) return BTSTACK_MEMORY_ALLOC_FAILED;
1924     if (is_ready(gatt_client) == 0) return GATT_CLIENT_IN_WRONG_STATE;
1925 
1926     gatt_client->callback = callback;
1927     gatt_client->attribute_handle = value_handle;
1928     gatt_client->attribute_length = value_length;
1929     gatt_client->attribute_offset = offset;
1930     gatt_client->attribute_value = data;
1931     gatt_client->gatt_client_state = P_W2_PREPARE_WRITE;
1932     gatt_client_run();
1933     return ERROR_CODE_SUCCESS;
1934 }
1935 
1936 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){
1937     return gatt_client_write_long_value_of_characteristic_with_offset(callback, con_handle, value_handle, 0, value_length, value);
1938 }
1939 
1940 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){
1941     gatt_client_t * gatt_client = gatt_client_provide_context_for_handle_and_start_timer(con_handle);
1942     if (gatt_client == NULL) return BTSTACK_MEMORY_ALLOC_FAILED;
1943     if (is_ready(gatt_client) == 0) return GATT_CLIENT_IN_WRONG_STATE;
1944 
1945     gatt_client->callback = callback;
1946     gatt_client->attribute_handle = value_handle;
1947     gatt_client->attribute_length = value_length;
1948     gatt_client->attribute_offset = 0;
1949     gatt_client->attribute_value = value;
1950     gatt_client->gatt_client_state = P_W2_PREPARE_RELIABLE_WRITE;
1951     gatt_client_run();
1952     return ERROR_CODE_SUCCESS;
1953 }
1954 
1955 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){
1956     gatt_client_t * gatt_client = gatt_client_provide_context_for_handle_and_start_timer(con_handle);
1957     if (gatt_client == NULL) return BTSTACK_MEMORY_ALLOC_FAILED;
1958     if (is_ready(gatt_client) == 0) return GATT_CLIENT_IN_WRONG_STATE;
1959 
1960     if ( (configuration & GATT_CLIENT_CHARACTERISTICS_CONFIGURATION_NOTIFICATION) &&
1961         ((characteristic->properties & ATT_PROPERTY_NOTIFY) == 0u)) {
1962         log_info("gatt_client_write_client_characteristic_configuration: GATT_CLIENT_CHARACTERISTIC_NOTIFICATION_NOT_SUPPORTED");
1963         return GATT_CLIENT_CHARACTERISTIC_NOTIFICATION_NOT_SUPPORTED;
1964     } else if ( (configuration & GATT_CLIENT_CHARACTERISTICS_CONFIGURATION_INDICATION) &&
1965                ((characteristic->properties & ATT_PROPERTY_INDICATE) == 0u)){
1966         log_info("gatt_client_write_client_characteristic_configuration: GATT_CLIENT_CHARACTERISTIC_INDICATION_NOT_SUPPORTED");
1967         return GATT_CLIENT_CHARACTERISTIC_INDICATION_NOT_SUPPORTED;
1968     }
1969 
1970     gatt_client->callback = callback;
1971     gatt_client->start_group_handle = characteristic->value_handle;
1972     gatt_client->end_group_handle = characteristic->end_handle;
1973     little_endian_store_16(gatt_client->client_characteristic_configuration_value, 0, configuration);
1974 
1975 #ifdef ENABLE_GATT_FIND_INFORMATION_FOR_CCC_DISCOVERY
1976     gatt_client->gatt_client_state = P_W2_SEND_FIND_CLIENT_CHARACTERISTIC_CONFIGURATION_QUERY;
1977 #else
1978     gatt_client->gatt_client_state = P_W2_SEND_READ_CLIENT_CHARACTERISTIC_CONFIGURATION_QUERY;
1979 #endif
1980     gatt_client_run();
1981     return ERROR_CODE_SUCCESS;
1982 }
1983 
1984 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){
1985     gatt_client_t * gatt_client = gatt_client_provide_context_for_handle_and_start_timer(con_handle);
1986     if (gatt_client == NULL) return BTSTACK_MEMORY_ALLOC_FAILED;
1987     if (is_ready(gatt_client) == 0) return GATT_CLIENT_IN_WRONG_STATE;
1988 
1989     gatt_client->callback = callback;
1990     gatt_client->attribute_handle = descriptor_handle;
1991 
1992     gatt_client->gatt_client_state = P_W2_SEND_READ_CHARACTERISTIC_DESCRIPTOR_QUERY;
1993     gatt_client_run();
1994     return ERROR_CODE_SUCCESS;
1995 }
1996 
1997 uint8_t gatt_client_read_characteristic_descriptor(btstack_packet_handler_t callback, hci_con_handle_t con_handle, gatt_client_characteristic_descriptor_t * descriptor){
1998     return gatt_client_read_characteristic_descriptor_using_descriptor_handle(callback, con_handle, descriptor->handle);
1999 }
2000 
2001 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){
2002     gatt_client_t * gatt_client = gatt_client_provide_context_for_handle_and_start_timer(con_handle);
2003     if (gatt_client == NULL) return BTSTACK_MEMORY_ALLOC_FAILED;
2004     if (is_ready(gatt_client) == 0) return GATT_CLIENT_IN_WRONG_STATE;
2005 
2006     gatt_client->callback = callback;
2007     gatt_client->attribute_handle = descriptor_handle;
2008     gatt_client->attribute_offset = offset;
2009     gatt_client->gatt_client_state = P_W2_SEND_READ_BLOB_CHARACTERISTIC_DESCRIPTOR_QUERY;
2010     gatt_client_run();
2011     return ERROR_CODE_SUCCESS;
2012 }
2013 
2014 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){
2015     return gatt_client_read_long_characteristic_descriptor_using_descriptor_handle_with_offset(callback, con_handle, descriptor_handle, 0);
2016 }
2017 
2018 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){
2019     return gatt_client_read_long_characteristic_descriptor_using_descriptor_handle(callback, con_handle, descriptor->handle);
2020 }
2021 
2022 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 length, uint8_t  * data){
2023     gatt_client_t * gatt_client = gatt_client_provide_context_for_handle_and_start_timer(con_handle);
2024     if (gatt_client == NULL) return BTSTACK_MEMORY_ALLOC_FAILED;
2025     if (is_ready(gatt_client) == 0) return GATT_CLIENT_IN_WRONG_STATE;
2026 
2027     gatt_client->callback = callback;
2028     gatt_client->attribute_handle = descriptor_handle;
2029     gatt_client->attribute_length = length;
2030     gatt_client->attribute_offset = 0;
2031     gatt_client->attribute_value = data;
2032     gatt_client->gatt_client_state = P_W2_SEND_WRITE_CHARACTERISTIC_DESCRIPTOR;
2033     gatt_client_run();
2034     return ERROR_CODE_SUCCESS;
2035 }
2036 
2037 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 length, uint8_t * value){
2038     return gatt_client_write_characteristic_descriptor_using_descriptor_handle(callback, con_handle, descriptor->handle, length, value);
2039 }
2040 
2041 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 length, uint8_t  * data){
2042     gatt_client_t * gatt_client = gatt_client_provide_context_for_handle_and_start_timer(con_handle);
2043     if (gatt_client == NULL) return BTSTACK_MEMORY_ALLOC_FAILED;
2044     if (is_ready(gatt_client) == 0) return GATT_CLIENT_IN_WRONG_STATE;
2045 
2046     gatt_client->callback = callback;
2047     gatt_client->attribute_handle = descriptor_handle;
2048     gatt_client->attribute_length = length;
2049     gatt_client->attribute_offset = offset;
2050     gatt_client->attribute_value = data;
2051     gatt_client->gatt_client_state = P_W2_PREPARE_WRITE_CHARACTERISTIC_DESCRIPTOR;
2052     gatt_client_run();
2053     return ERROR_CODE_SUCCESS;
2054 }
2055 
2056 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 length, uint8_t * data){
2057     return gatt_client_write_long_characteristic_descriptor_using_descriptor_handle_with_offset(callback, con_handle, descriptor_handle, 0, length, data );
2058 }
2059 
2060 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 length, uint8_t * value){
2061     return gatt_client_write_long_characteristic_descriptor_using_descriptor_handle(callback, con_handle, descriptor->handle, length, value);
2062 }
2063 
2064 /**
2065  * @brief -> gatt complete event
2066  */
2067 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 length, uint8_t * data){
2068     gatt_client_t * gatt_client = gatt_client_provide_context_for_handle_and_start_timer(con_handle);
2069     if (gatt_client == NULL) return BTSTACK_MEMORY_ALLOC_FAILED;
2070     if (is_ready(gatt_client) == 0) return GATT_CLIENT_IN_WRONG_STATE;
2071 
2072     gatt_client->callback = callback;
2073     gatt_client->attribute_handle = attribute_handle;
2074     gatt_client->attribute_length = length;
2075     gatt_client->attribute_offset = offset;
2076     gatt_client->attribute_value = data;
2077     gatt_client->gatt_client_state = P_W2_PREPARE_WRITE_SINGLE;
2078     gatt_client_run();
2079     return ERROR_CODE_SUCCESS;
2080 }
2081 
2082 /**
2083  * @brief -> gatt complete event
2084  */
2085 uint8_t gatt_client_execute_write(btstack_packet_handler_t callback, hci_con_handle_t con_handle){
2086     gatt_client_t * gatt_client = gatt_client_provide_context_for_handle_and_start_timer(con_handle);
2087 
2088     if (gatt_client == NULL) return BTSTACK_MEMORY_ALLOC_FAILED;
2089     if (is_ready(gatt_client) == 0) return GATT_CLIENT_IN_WRONG_STATE;
2090 
2091     gatt_client->callback = callback;
2092     gatt_client->gatt_client_state = P_W2_EXECUTE_PREPARED_WRITE;
2093     gatt_client_run();
2094     return ERROR_CODE_SUCCESS;
2095 }
2096 
2097 /**
2098  * @brief -> gatt complete event
2099  */
2100 uint8_t gatt_client_cancel_write(btstack_packet_handler_t callback, hci_con_handle_t con_handle){
2101     gatt_client_t * gatt_client = gatt_client_provide_context_for_handle_and_start_timer(con_handle);
2102     if (gatt_client == NULL) return BTSTACK_MEMORY_ALLOC_FAILED;
2103     if (is_ready(gatt_client) == 0) return GATT_CLIENT_IN_WRONG_STATE;
2104 
2105     gatt_client->callback = callback;
2106     gatt_client->gatt_client_state = P_W2_CANCEL_PREPARED_WRITE;
2107     gatt_client_run();
2108     return ERROR_CODE_SUCCESS;
2109 }
2110 
2111 void gatt_client_deserialize_service(const uint8_t *packet, int offset, gatt_client_service_t *service){
2112     service->start_group_handle = little_endian_read_16(packet, offset);
2113     service->end_group_handle = little_endian_read_16(packet, offset + 2);
2114     reverse_128(&packet[offset + 4], service->uuid128);
2115     if (uuid_has_bluetooth_prefix(service->uuid128)){
2116         service->uuid16 = big_endian_read_32(service->uuid128, 0);
2117     } else {
2118         service->uuid16 = 0;
2119     }
2120 }
2121 
2122 void gatt_client_deserialize_characteristic(const uint8_t * packet, int offset, gatt_client_characteristic_t * characteristic){
2123     characteristic->start_handle = little_endian_read_16(packet, offset);
2124     characteristic->value_handle = little_endian_read_16(packet, offset + 2);
2125     characteristic->end_handle = little_endian_read_16(packet, offset + 4);
2126     characteristic->properties = little_endian_read_16(packet, offset + 6);
2127     reverse_128(&packet[offset+8], characteristic->uuid128);
2128     if (uuid_has_bluetooth_prefix(characteristic->uuid128)){
2129         characteristic->uuid16 = big_endian_read_32(characteristic->uuid128, 0);
2130     } else {
2131         characteristic->uuid16 = 0;
2132     }
2133 }
2134 
2135 void gatt_client_deserialize_characteristic_descriptor(const uint8_t * packet, int offset, gatt_client_characteristic_descriptor_t * descriptor){
2136     descriptor->handle = little_endian_read_16(packet, offset);
2137     reverse_128(&packet[offset+2], descriptor->uuid128);
2138     if (uuid_has_bluetooth_prefix(descriptor->uuid128)){
2139         descriptor->uuid16 = big_endian_read_32(descriptor->uuid128, 0);
2140     } else {
2141         descriptor->uuid16 = 0;
2142     }
2143 }
2144 
2145 void gatt_client_send_mtu_negotiation(btstack_packet_handler_t callback, hci_con_handle_t con_handle){
2146     gatt_client_t * context = gatt_client_provide_context_for_handle(con_handle);
2147     if (context == NULL) return;
2148     if (context->mtu_state == MTU_AUTO_EXCHANGE_DISABLED){
2149         context->callback = callback;
2150         context->mtu_state = SEND_MTU_EXCHANGE;
2151         gatt_client_run();
2152     }
2153 }
2154 
2155 uint8_t gatt_client_request_can_write_without_response_event(btstack_packet_handler_t callback, hci_con_handle_t con_handle){
2156     gatt_client_t * context = gatt_client_provide_context_for_handle(con_handle);
2157     if (context == NULL) return BTSTACK_MEMORY_ALLOC_FAILED;
2158     if (context->write_without_response_callback != NULL) return GATT_CLIENT_IN_WRONG_STATE;
2159     context->write_without_response_callback = callback;
2160     att_dispatch_client_request_can_send_now_event(context->con_handle);
2161     return ERROR_CODE_SUCCESS;
2162 }
2163 
2164 #ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
2165 void gatt_client_att_packet_handler_fuzz(uint8_t packet_type, uint16_t handle, uint8_t *packet, uint16_t size){
2166     gatt_client_att_packet_handler(packet_type, handle, packet, size);
2167 }
2168 #endif
2169