xref: /btstack/src/ble/gatt-service/hids_client.c (revision 835a13f1ce0229519cd8ee0d0c65924ab20e68cf)
1 /*
2  * Copyright (C) 2021 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__ "hids_client.c"
39 
40 #include "btstack_config.h"
41 
42 #ifdef ENABLE_TESTING_SUPPORT
43 #include <stdio.h>
44 #endif
45 
46 #include <stdint.h>
47 #include <string.h>
48 
49 #include "ble/gatt-service/hids_client.h"
50 
51 #include "btstack_memory.h"
52 #include "ble/att_db.h"
53 #include "ble/core.h"
54 #include "ble/gatt_client.h"
55 #include "ble/sm.h"
56 #include "bluetooth_gatt.h"
57 #include "btstack_debug.h"
58 #include "btstack_event.h"
59 #include "btstack_run_loop.h"
60 #include "gap.h"
61 
62 #define HID_REPORT_MODE_REPORT_ID               3
63 #define HID_REPORT_MODE_REPORT_MAP_ID           4
64 #define HID_REPORT_MODE_HID_INFORMATION_ID      5
65 #define HID_REPORT_MODE_HID_CONTROL_POINT_ID    6
66 
67 static btstack_linked_list_t clients;
68 static uint16_t hids_cid_counter = 0;
69 
70 static uint8_t * hids_client_descriptor_storage;
71 static uint16_t  hids_client_descriptor_storage_len;
72 
73 static void handle_gatt_client_event(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
74 
75 #ifdef ENABLE_TESTING_SUPPORT
76 static char * hid_characteristic_name(uint16_t uuid){
77     switch (uuid){
78         case ORG_BLUETOOTH_CHARACTERISTIC_PROTOCOL_MODE:
79             return "PROTOCOL_MODE";
80 
81         case ORG_BLUETOOTH_CHARACTERISTIC_BOOT_KEYBOARD_INPUT_REPORT:
82             return "BOOT_KEYBOARD_INPUT_REPORT";
83 
84         case ORG_BLUETOOTH_CHARACTERISTIC_BOOT_MOUSE_INPUT_REPORT:
85             return "BOOT_MOUSE_INPUT_REPORT";
86 
87         case ORG_BLUETOOTH_CHARACTERISTIC_BOOT_KEYBOARD_OUTPUT_REPORT:
88             return "BOOT_KEYBOARD_OUTPUT_REPORT";
89 
90         case ORG_BLUETOOTH_CHARACTERISTIC_REPORT:
91             return "REPORT";
92 
93         case ORG_BLUETOOTH_CHARACTERISTIC_REPORT_MAP:
94             return "REPORT_MAP";
95 
96         case ORG_BLUETOOTH_CHARACTERISTIC_HID_INFORMATION:
97             return "HID_INFORMATION";
98 
99         case ORG_BLUETOOTH_CHARACTERISTIC_HID_CONTROL_POINT:
100             return "HID_CONTROL_POINT";
101         default:
102             return "UKNOWN";
103     }
104 }
105 #endif
106 
107 static hids_client_t * hids_get_client_for_con_handle(hci_con_handle_t con_handle){
108     btstack_linked_list_iterator_t it;
109     btstack_linked_list_iterator_init(&it, &clients);
110     while (btstack_linked_list_iterator_has_next(&it)){
111         hids_client_t * client = (hids_client_t *)btstack_linked_list_iterator_next(&it);
112         if (client->con_handle != con_handle) continue;
113         return client;
114     }
115     return NULL;
116 }
117 
118 static hids_client_t * hids_get_client_for_cid(uint16_t hids_cid){
119     btstack_linked_list_iterator_t it;
120     btstack_linked_list_iterator_init(&it, &clients);
121     while (btstack_linked_list_iterator_has_next(&it)){
122         hids_client_t * client = (hids_client_t *)btstack_linked_list_iterator_next(&it);
123         if (client->cid != hids_cid) continue;
124         return client;
125     }
126     return NULL;
127 }
128 
129 
130 // START Descriptor Storage Util
131 
132 static uint16_t hids_client_descriptor_storage_get_available_space(void){
133     // assumes all descriptors are back to back
134     uint16_t free_space = hids_client_descriptor_storage_len;
135     uint8_t i;
136 
137     btstack_linked_list_iterator_t it;
138     btstack_linked_list_iterator_init(&it, &clients);
139     while (btstack_linked_list_iterator_has_next(&it)){
140         hids_client_t * client = (hids_client_t *)btstack_linked_list_iterator_next(&it);
141         for (i = 0; i < client->num_instances; i++){
142             free_space -= client->services[i].hid_descriptor_len;
143         }
144     }
145     return free_space;
146 }
147 
148 static void hids_client_descriptor_storage_init(hids_client_t * client, uint8_t service_index){
149     client->services[service_index].hid_descriptor_len = 0;
150     client->services[service_index].hid_descriptor_max_len = hids_client_descriptor_storage_get_available_space();
151     client->services[service_index].hid_descriptor_offset = hids_client_descriptor_storage_len - client->services[service_index].hid_descriptor_max_len;
152 }
153 
154 static bool hids_client_descriptor_storage_store(hids_client_t * client, uint8_t service_index, uint8_t byte){
155     if (client->services[service_index].hid_descriptor_len >= client->services[service_index].hid_descriptor_max_len) return false;
156 
157     hids_client_descriptor_storage[client->services[service_index].hid_descriptor_offset + client->services[service_index].hid_descriptor_len] = byte;
158     client->services[service_index].hid_descriptor_len++;
159     return true;
160 }
161 
162 static void hids_client_descriptor_storage_delete(hids_client_t * client){
163     uint8_t service_index = 0;
164     uint16_t next_offset = 0;
165 
166     for (service_index = 0; service_index < client->num_instances; service_index++){
167         next_offset += client->services[service_index].hid_descriptor_offset + client->services[service_index].hid_descriptor_len;
168         client->services[service_index].hid_descriptor_len = 0;
169         client->services[service_index].hid_descriptor_offset = 0;
170     }
171 
172     memmove(&hids_client_descriptor_storage[client->services[0].hid_descriptor_offset],
173             &hids_client_descriptor_storage[next_offset],
174             hids_client_descriptor_storage_len - next_offset);
175 
176     uint8_t i;
177     btstack_linked_list_iterator_t it;
178     btstack_linked_list_iterator_init(&it, &clients);
179     while (btstack_linked_list_iterator_has_next(&it)){
180         hids_client_t * conn = (hids_client_t *)btstack_linked_list_iterator_next(&it);
181         for (i = 0; i < client->num_instances; i++){
182             if (conn->services[i].hid_descriptor_offset >= next_offset){
183                 conn->services[i].hid_descriptor_offset = next_offset;
184                 next_offset += conn->services[service_index].hid_descriptor_len;
185             }
186         }
187     }
188 }
189 
190 const uint8_t * hids_client_descriptor_storage_get_descriptor_data(uint16_t hids_cid, uint8_t service_index){
191     hids_client_t * client = hids_get_client_for_cid(hids_cid);
192     if (client == NULL){
193         return NULL;
194     }
195     if (service_index >= client->num_instances){
196         return NULL;
197     }
198     return &hids_client_descriptor_storage[client->services[service_index].hid_descriptor_offset];
199 }
200 
201 uint16_t hids_client_descriptor_storage_get_descriptor_len(uint16_t hids_cid, uint8_t service_index){
202     hids_client_t * client = hids_get_client_for_cid(hids_cid);
203     if (client == NULL){
204         return 0;
205     }
206     if (service_index >= client->num_instances){
207         return 0;
208     }
209     return client->services[service_index].hid_descriptor_len;
210 }
211 
212 // END Descriptor Storage Util
213 
214 static uint16_t hids_get_next_cid(void){
215     if (hids_cid_counter == 0xffff) {
216         hids_cid_counter = 1;
217     } else {
218         hids_cid_counter++;
219     }
220     return hids_cid_counter;
221 }
222 
223 static uint8_t find_report_index_for_value_handle(hids_client_t * client, uint16_t value_handle){
224     uint8_t i;
225     for (i = 0; i < client->num_reports; i++){
226         if (client->reports[i].value_handle == value_handle){
227             return i;
228         }
229     }
230     return HIDS_CLIENT_INVALID_REPORT_INDEX;
231 }
232 
233 static uint8_t find_external_report_index_for_value_handle(hids_client_t * client, uint16_t value_handle){
234     uint8_t i;
235     for (i = 0; i < client->num_external_reports; i++){
236         if (client->external_reports[i].value_handle == value_handle){
237             return i;
238         }
239     }
240     return HIDS_CLIENT_INVALID_REPORT_INDEX;
241 }
242 
243 static bool external_report_index_for_uuid_exists(hids_client_t * client, uint16_t uuid16){
244     uint8_t i;
245     for (i = 0; i < client->num_external_reports; i++){
246         if (client->external_reports[i].external_report_reference_uuid == uuid16){
247             return true;
248         }
249     }
250     return false;
251 }
252 
253 static uint8_t find_report_index_for_report_id(hids_client_t * client, uint8_t report_id){
254     uint8_t i;
255 
256     switch (client->protocol_mode){
257         case HID_PROTOCOL_MODE_BOOT:
258             for (i = 0; i < client->num_reports; i++){
259                 if (!client->reports[i].boot_report){
260                     continue;
261                 }
262                 if (client->reports[i].report_id == report_id){
263                     return i;
264                 }
265             }
266             break;
267 
268         default:
269             for (i = 0; i < client->num_reports; i++){
270                 if (client->reports[i].boot_report){
271                     continue;
272                 }
273                 if (client->reports[i].report_id == report_id){
274                     return i;
275                 }
276             }
277             break;
278     }
279     return HIDS_CLIENT_INVALID_REPORT_INDEX;
280 }
281 
282 
283 static uint8_t find_report_index_for_report_id_and_type(hids_client_t * client, uint8_t report_id, hid_report_type_t report_type){
284     uint8_t i;
285     switch (client->protocol_mode){
286         case HID_PROTOCOL_MODE_BOOT:
287             for (i = 0; i < client->num_reports; i++){
288                 if (!client->reports[i].boot_report){
289                     continue;
290                 }
291                 if ((client->reports[i].report_id == report_id) && (client->reports[i].report_type == report_type)){
292                     return i;
293                 }
294             }
295             break;
296 
297         default:
298             for (i = 0; i < client->num_reports; i++){
299                 if (client->reports[i].boot_report){
300                     continue;
301                 }
302                 if ((client->reports[i].report_id == report_id) && (client->reports[i].report_type == report_type)){
303                     return i;
304                 }
305             }
306             break;
307     }
308     return HIDS_CLIENT_INVALID_REPORT_INDEX;
309 }
310 
311 static uint8_t hids_client_add_characteristic(hids_client_t * client, gatt_client_characteristic_t * characteristic, uint8_t report_id, hid_report_type_t report_type, bool boot_report){
312 
313     uint8_t report_index = find_external_report_index_for_value_handle(client, characteristic->value_handle);
314     if (report_index != HIDS_CLIENT_INVALID_REPORT_INDEX){
315         return report_index;
316     }
317     report_index = client->num_reports;
318 
319     if (report_index < HIDS_CLIENT_NUM_REPORTS) {
320         client->reports[report_index].value_handle = characteristic->value_handle;
321         client->reports[report_index].end_handle = characteristic->end_handle;
322         client->reports[report_index].properties = characteristic->properties;
323 
324         client->reports[report_index].service_index = client->service_index;
325         client->reports[report_index].report_id = report_id;
326         client->reports[report_index].report_type = report_type;
327         client->reports[report_index].boot_report = boot_report;
328 
329         log_info("add index %d, id %d, type %d, value handle 0x%02x, properties 0x%02x", report_index, report_id, report_type, characteristic->value_handle, characteristic->properties);
330         client->num_reports++;
331         return report_index;
332     } else {
333         log_info("not enough storage, increase HIDS_CLIENT_NUM_REPORTS");
334         return HIDS_CLIENT_INVALID_REPORT_INDEX;
335     }
336 }
337 
338 static uint8_t hids_client_add_external_report(hids_client_t * client, gatt_client_characteristic_descriptor_t * characteristic_descriptor){
339     uint8_t report_index = client->num_external_reports;
340 
341     if (report_index < HIDS_CLIENT_NUM_REPORTS) {
342         client->external_reports[report_index].value_handle = characteristic_descriptor->handle;
343         client->external_reports[report_index].service_index = client->service_index;
344 
345         client->num_external_reports++;
346         log_info("add external index %d [%d], value handle 0x%02x", report_index, client->num_external_reports, characteristic_descriptor->handle);
347         return report_index;
348     } else {
349         log_info("not enough storage, increase HIDS_CLIENT_NUM_REPORTS");
350         return HIDS_CLIENT_INVALID_REPORT_INDEX;
351     }
352 }
353 
354 
355 static bool hid_clients_has_reports_in_report_mode(hids_client_t * client){
356     uint8_t i;
357     for (i = 0; i < client->num_reports; i++){
358         if (!client->reports[i].boot_report){
359             return true;
360         }
361     }
362     return false;
363 }
364 
365 static bool hid_clients_has_reports_in_boot_mode(hids_client_t * client){
366     uint8_t i;
367     for (i = 0; i < client->num_reports; i++){
368         if (client->reports[i].boot_report){
369             return true;
370         }
371     }
372     return false;
373 }
374 
375 static uint8_t hids_client_get_next_active_report_map_index(hids_client_t * client){
376     uint8_t i;
377     for (i = client->service_index; i < client->num_instances; i++){
378         if (client->services[i].report_map_value_handle != 0){
379             return i;
380         }
381     }
382     client->service_index = HIDS_CLIENT_INVALID_REPORT_INDEX;
383     return HIDS_CLIENT_INVALID_REPORT_INDEX;
384 }
385 
386 static bool hids_client_report_query_next_report_map(hids_client_t * client){
387     client->service_index++;
388     if (hids_client_get_next_active_report_map_index(client) != HIDS_CLIENT_INVALID_REPORT_INDEX){
389         client->state = HIDS_CLIENT_STATE_W2_READ_REPORT_MAP_HID_DESCRIPTOR;
390         return true;
391     }
392     return false;
393 }
394 
395 static bool hids_client_report_map_query_init(hids_client_t * client){
396     client->service_index = 0;
397 
398     if (hids_client_get_next_active_report_map_index(client) != HIDS_CLIENT_INVALID_REPORT_INDEX){
399         client->state = HIDS_CLIENT_STATE_W2_READ_REPORT_MAP_HID_DESCRIPTOR;
400         return true;
401     }
402     return false;
403 }
404 
405 static bool hids_client_report_query_next_report_map_uuid(hids_client_t * client){
406     client->report_index++;
407     if (client->report_index < client->num_external_reports){
408         client->state = HIDS_CLIENT_STATE_W2_REPORT_MAP_READ_EXTERNAL_REPORT_REFERENCE_UUID;
409         return true;
410     }
411     return false;
412 }
413 
414 static bool hids_client_report_map_uuid_query_init(hids_client_t * client){
415     client->report_index = 0;
416     if (client->num_external_reports > 0){
417         client->state = HIDS_CLIENT_STATE_W2_REPORT_MAP_READ_EXTERNAL_REPORT_REFERENCE_UUID;
418         return true;
419     }
420     return false;
421 }
422 
423 static uint8_t hids_client_get_next_report_index(hids_client_t * client){
424     uint8_t i;
425     uint8_t index = HIDS_CLIENT_INVALID_REPORT_INDEX;
426     switch (client->protocol_mode){
427         case HID_PROTOCOL_MODE_REPORT:
428             for (i = client->report_index; i < client->num_reports && (index == HIDS_CLIENT_INVALID_REPORT_INDEX); i++){
429                 hids_client_report_t report = client->reports[i];
430                 if (report.report_type == HID_REPORT_TYPE_RESERVED && report.report_id == HID_REPORT_MODE_REPORT_ID){
431                     index = i;
432                     client->service_index = report.service_index;
433                 }
434             }
435             break;
436         case HID_PROTOCOL_MODE_BOOT:
437             for (i = client->report_index; i < client->num_reports && (index == HIDS_CLIENT_INVALID_REPORT_INDEX); i++){
438                 hids_client_report_t report = client->reports[i];
439                 if (report.boot_report){
440                     index = i;
441                     client->service_index = report.service_index;
442                 }
443             }
444             break;
445         default:
446             break;
447     }
448 
449     client->report_index = index;
450     return index;
451 }
452 
453 static bool hids_client_report_query_next_report(hids_client_t * client){
454     client->report_index++;
455     if (hids_client_get_next_report_index(client) != HIDS_CLIENT_INVALID_REPORT_INDEX){
456         client->state = HIDS_CLIENT_STATE_W2_FIND_REPORT;
457         return true;
458     }
459     return false;
460 }
461 
462 static bool hids_client_report_query_init(hids_client_t * client){
463     client->report_index = 0;
464 
465     if (hids_client_get_next_report_index(client) != HIDS_CLIENT_INVALID_REPORT_INDEX){
466         client->state = HIDS_CLIENT_STATE_W2_FIND_REPORT;
467         return true;
468     }
469     return false;
470 }
471 
472 static uint8_t hids_client_get_next_notification_report_index(hids_client_t * client){
473     uint8_t i;
474     uint8_t index = HIDS_CLIENT_INVALID_REPORT_INDEX;
475 
476     switch (client->protocol_mode){
477         case HID_PROTOCOL_MODE_REPORT:
478             for (i = client->report_index; i < client->num_reports && (index == HIDS_CLIENT_INVALID_REPORT_INDEX); i++){
479                 hids_client_report_t report = client->reports[i];
480                 if (report.report_type != HID_REPORT_TYPE_INPUT){
481                     continue;
482                 }
483                 if (!report.boot_report){
484                     index = i;
485                 }
486             }
487             break;
488 
489         case HID_PROTOCOL_MODE_BOOT:
490             for (i = client->report_index; i < client->num_reports && (index == HIDS_CLIENT_INVALID_REPORT_INDEX); i++){
491                 hids_client_report_t report = client->reports[i];
492                 if (report.report_type != HID_REPORT_TYPE_INPUT){
493                     continue;
494                 }
495                 if (report.boot_report){
496                     index = i;
497                 }
498             }
499             break;
500 
501         default:
502             break;
503     }
504 
505     client->report_index = index;
506     return index;
507 }
508 
509 static bool hids_client_report_next_notification_report_index(hids_client_t * client){
510     client->report_index++;
511     if (hids_client_get_next_notification_report_index(client) != HIDS_CLIENT_INVALID_REPORT_INDEX){
512         client->state = HIDS_CLIENT_STATE_W2_ENABLE_INPUT_REPORTS;
513         return true;
514     }
515     return false;
516 }
517 
518 static bool hids_client_report_notifications_init(hids_client_t * client){
519     client->report_index = 0;
520 
521     if (hids_client_get_next_notification_report_index(client) != HIDS_CLIENT_INVALID_REPORT_INDEX){
522         client->state = HIDS_CLIENT_STATE_W2_ENABLE_INPUT_REPORTS;
523         return true;
524     }
525     return false;
526 }
527 
528 static hids_client_t * hids_create_client(hci_con_handle_t con_handle, uint16_t cid){
529     hids_client_t * client = btstack_memory_hids_client_get();
530     if (!client){
531         log_error("Not enough memory to create client");
532         return NULL;
533     }
534     client->state = HIDS_CLIENT_STATE_IDLE;
535     client->cid = cid;
536     client->con_handle = con_handle;
537 
538     btstack_linked_list_add(&clients, (btstack_linked_item_t *) client);
539     return client;
540 }
541 
542 static void hids_finalize_client(hids_client_t * client){
543     // stop listening
544     uint8_t i;
545     for (i = 0; i < client->num_reports; i++){
546         gatt_client_stop_listening_for_characteristic_value_updates(&client->reports[i].notification_listener);
547     }
548 
549     hids_client_descriptor_storage_delete(client);
550     btstack_linked_list_remove(&clients, (btstack_linked_item_t *) client);
551     btstack_memory_hids_client_free(client);
552 }
553 
554 
555 static void hids_emit_connection_established(hids_client_t * client, uint8_t status){
556     uint8_t event[8];
557     int pos = 0;
558     event[pos++] = HCI_EVENT_GATTSERVICE_META;
559     event[pos++] = sizeof(event) - 2;
560     event[pos++] = GATTSERVICE_SUBEVENT_HID_SERVICE_CONNECTED;
561     little_endian_store_16(event, pos, client->cid);
562     pos += 2;
563     event[pos++] = status;
564     event[pos++] = client->protocol_mode;
565     event[pos++] = client->num_instances;
566     (*client->client_handler)(HCI_EVENT_PACKET, 0, event, sizeof(event));
567 }
568 
569 static void hids_client_setup_report_event(hids_client_t * client, uint8_t report_index, uint8_t *buffer, uint16_t report_len){
570     uint16_t pos = 0;
571     buffer[pos++] = HCI_EVENT_GATTSERVICE_META;
572     pos++;  // skip len
573     buffer[pos++] = GATTSERVICE_SUBEVENT_HID_REPORT;
574     little_endian_store_16(buffer, pos, client->cid);
575     pos += 2;
576     buffer[pos++] = client->reports[report_index].service_index;
577     buffer[pos++] = client->reports[report_index].report_id;
578     little_endian_store_16(buffer, pos, report_len + 1);
579     pos += 2;
580     buffer[pos++] = client->reports[report_index].report_id;
581     buffer[1] = pos + (report_len + 1) - 2;
582 
583 }
584 
585 static void handle_notification_event(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size) {
586     UNUSED(packet_type);
587     UNUSED(channel);
588 
589     if (hci_event_packet_get_type(packet) != GATT_EVENT_NOTIFICATION) return;
590 
591     hids_client_t * client = hids_get_client_for_con_handle(gatt_event_notification_get_handle(packet));
592     btstack_assert(client != NULL);
593 
594     uint8_t report_index = find_report_index_for_value_handle(client, gatt_event_notification_get_value_handle(packet));
595     if (report_index == HIDS_CLIENT_INVALID_REPORT_INDEX){
596         return;
597     }
598 
599     uint8_t * in_place_event = &packet[-2];
600     hids_client_setup_report_event(client, report_index, in_place_event, gatt_event_notification_get_value_length(packet));
601     (*client->client_handler)(HCI_EVENT_GATTSERVICE_META, client->cid, in_place_event, size + 2);
602 }
603 
604 static void handle_report_event(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size) {
605     UNUSED(packet_type);
606     UNUSED(channel);
607 
608     if (hci_event_packet_get_type(packet) != GATT_EVENT_CHARACTERISTIC_VALUE_QUERY_RESULT) return;
609 
610     hids_client_t * client = hids_get_client_for_con_handle(gatt_event_characteristic_value_query_result_get_handle(packet));
611     btstack_assert(client != NULL);
612 
613     if (client->state != HIDS_CLIENT_W4_GET_REPORT_RESULT){
614         return;
615     }
616     client->state = HIDS_CLIENT_STATE_CONNECTED;
617 
618     uint8_t report_index = find_report_index_for_value_handle(client, gatt_event_characteristic_value_query_result_get_value_handle(packet));
619     if (report_index == HIDS_CLIENT_INVALID_REPORT_INDEX){
620         return;
621     }
622 
623     uint8_t * in_place_event = &packet[-2];
624     hids_client_setup_report_event(client, report_index, in_place_event, gatt_event_characteristic_value_query_result_get_value_length(packet));
625     (*client->client_handler)(HCI_EVENT_GATTSERVICE_META, client->cid, in_place_event, size + 2);
626 }
627 
628 static void hids_run_for_client(hids_client_t * client){
629     uint8_t att_status;
630     gatt_client_service_t service;
631     gatt_client_characteristic_t characteristic;
632 
633     switch (client->state){
634         case HIDS_CLIENT_STATE_W2_QUERY_SERVICE:
635 #ifdef ENABLE_TESTING_SUPPORT
636             printf("\n\nQuery Services:\n");
637 #endif
638             client->state = HIDS_CLIENT_STATE_W4_SERVICE_RESULT;
639 
640             // result in GATT_EVENT_SERVICE_QUERY_RESULT
641             att_status = gatt_client_discover_primary_services_by_uuid16(handle_gatt_client_event, client->con_handle, ORG_BLUETOOTH_SERVICE_HUMAN_INTERFACE_DEVICE);
642             UNUSED(att_status);
643             break;
644 
645         case HIDS_CLIENT_STATE_W2_QUERY_CHARACTERISTIC:
646 #ifdef ENABLE_TESTING_SUPPORT
647             printf("\n\nQuery Characteristics of service %d:\n", client->service_index);
648 #endif
649             client->state = HIDS_CLIENT_STATE_W4_CHARACTERISTIC_RESULT;
650 
651             service.start_group_handle = client->services[client->service_index].start_handle;
652             service.end_group_handle = client->services[client->service_index].end_handle;
653 
654             // result in GATT_EVENT_CHARACTERISTIC_QUERY_RESULT
655             att_status = gatt_client_discover_characteristics_for_service(&handle_gatt_client_event, client->con_handle, &service);
656 
657             UNUSED(att_status);
658             break;
659 
660         case HIDS_CLIENT_STATE_W2_SET_BOOT_PROTOCOL_MODE:
661             att_status = gatt_client_write_value_of_characteristic_without_response(client->con_handle, client->protocol_mode_value_handle, 1, (uint8_t *)&client->required_protocol_mode);
662             UNUSED(att_status);
663 
664             client->protocol_mode = client->required_protocol_mode;
665             if (hids_client_report_query_init(client)){
666                 break;
667             }
668 
669             hids_emit_connection_established(client, ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE);
670             hids_finalize_client(client);
671             break;
672 
673         case HIDS_CLIENT_STATE_W2_READ_REPORT_MAP_HID_DESCRIPTOR:
674 #ifdef ENABLE_TESTING_SUPPORT
675             printf("\n\nRead REPORT_MAP (Handle 0x%04X) HID Descriptor of service %d:\n", client->services[client->service_index].report_map_value_handle, client->service_index);
676 #endif
677             client->state = HIDS_CLIENT_STATE_W4_REPORT_MAP_HID_DESCRIPTOR;
678 
679             // result in GATT_EVENT_LONG_CHARACTERISTIC_VALUE_QUERY_RESULT
680             att_status = gatt_client_read_long_value_of_characteristic_using_value_handle(&handle_gatt_client_event, client->con_handle, client->services[client->service_index].report_map_value_handle);
681             UNUSED(att_status);
682             break;
683 
684         case HIDS_CLIENT_STATE_W2_REPORT_MAP_DISCOVER_CHARACTERISTIC_DESCRIPTORS:
685 #ifdef ENABLE_TESTING_SUPPORT
686             printf("\nDiscover REPORT_MAP (Handle 0x%04X) Characteristic Descriptors of service %d:\n", client->services[client->service_index].report_map_value_handle, client->service_index);
687 #endif
688             client->state = HIDS_CLIENT_STATE_W4_REPORT_MAP_CHARACTERISTIC_DESCRIPTORS_RESULT;
689 
690             characteristic.value_handle = client->services[client->service_index].report_map_value_handle;
691             characteristic.end_handle = client->services[client->service_index].report_map_end_handle;
692 
693             // result in GATT_EVENT_ALL_CHARACTERISTIC_DESCRIPTORS_QUERY_RESULT
694             att_status = gatt_client_discover_characteristic_descriptors(&handle_gatt_client_event, client->con_handle, &characteristic);
695             UNUSED(att_status);
696             break;
697 
698         case HIDS_CLIENT_STATE_W2_REPORT_MAP_READ_EXTERNAL_REPORT_REFERENCE_UUID:
699 #ifdef ENABLE_TESTING_SUPPORT
700             printf("\nRead external chr UUID (Handle 0x%04X) Characteristic Descriptors, service index %d:\n", client->external_reports[client->report_index].value_handle, client->service_index);
701 #endif
702             client->state = HIDS_CLIENT_STATE_W4_REPORT_MAP_EXTERNAL_REPORT_REFERENCE_UUID;
703 
704             // result in GATT_EVENT_CHARACTERISTIC_DESCRIPTOR_QUERY_RESULT
705             att_status = gatt_client_read_characteristic_descriptor_using_descriptor_handle(&handle_gatt_client_event, client->con_handle, client->external_reports[client->report_index].value_handle);
706             UNUSED(att_status);
707             break;
708 
709         case HIDS_CLIENT_STATE_W2_DISCOVER_EXTERNAL_REPORT_CHARACTERISTIC:
710  #ifdef ENABLE_TESTING_SUPPORT
711             printf("\nDiscover External Report Characteristic:\n");
712 #endif
713             client->state = HIDS_CLIENT_STATE_W4_EXTERNAL_REPORT_CHARACTERISTIC_RESULT;
714 
715             service.start_group_handle = 0x0001;
716             service.end_group_handle = 0xffff;
717 
718             // Result in GATT_EVENT_CHARACTERISTIC_QUERY_RESULT
719             att_status = gatt_client_discover_characteristics_for_service(&handle_gatt_client_event, client->con_handle, &service);
720             UNUSED(att_status);
721             break;
722 
723         case HIDS_CLIENT_STATE_W2_FIND_REPORT:
724 #ifdef ENABLE_TESTING_SUPPORT
725             printf("\nQuery Report Characteristic Descriptors [%d, %d, 0x%04X]:\n",
726                 client->report_index,
727                 client->reports[client->report_index].service_index,
728                 client->reports[client->report_index].value_handle);
729 #endif
730             client->state = HIDS_CLIENT_STATE_W4_REPORT_FOUND;
731             client->descriptor_handle = 0;
732 
733             characteristic.value_handle = client->reports[client->report_index].value_handle;
734             characteristic.end_handle = client->reports[client->report_index].end_handle;
735             characteristic.properties = client->reports[client->report_index].properties;
736 
737             // result in GATT_EVENT_ALL_CHARACTERISTIC_DESCRIPTORS_QUERY_RESULT
738             att_status = gatt_client_discover_characteristic_descriptors(&handle_gatt_client_event, client->con_handle, &characteristic);
739             UNUSED(att_status);
740             break;
741 
742         case HIDS_CLIENT_STATE_W2_READ_REPORT_ID_AND_TYPE:
743             client->state = HIDS_CLIENT_STATE_W4_REPORT_ID_AND_TYPE;
744 
745             // result in GATT_EVENT_CHARACTERISTIC_DESCRIPTOR_QUERY_RESULT
746             att_status = gatt_client_read_characteristic_descriptor_using_descriptor_handle(&handle_gatt_client_event, client->con_handle, client->descriptor_handle);
747             client->descriptor_handle = 0;
748             UNUSED(att_status);
749             break;
750 
751         case HIDS_CLIENT_STATE_W2_ENABLE_INPUT_REPORTS:
752             client->state = HIDS_CLIENT_STATE_W4_INPUT_REPORTS_ENABLED;
753 
754             characteristic.value_handle = client->reports[client->report_index].value_handle;
755             characteristic.end_handle = client->reports[client->report_index].end_handle;
756             characteristic.properties = client->reports[client->report_index].properties;
757 
758             // end of write marked in GATT_EVENT_QUERY_COMPLETE
759             att_status = gatt_client_write_client_characteristic_configuration(&handle_gatt_client_event, client->con_handle, &characteristic, GATT_CLIENT_CHARACTERISTICS_CONFIGURATION_NOTIFICATION);
760 
761             if (att_status != ERROR_CODE_SUCCESS){
762                 if (hids_client_report_next_notification_report_index(client)){
763                     hids_run_for_client(client);
764                     break;
765                 }
766                 client->state = HIDS_CLIENT_STATE_CONNECTED;
767                 hids_emit_connection_established(client, ERROR_CODE_SUCCESS);
768             } else {
769                 gatt_client_listen_for_characteristic_value_updates(
770                     &client->reports[client->report_index].notification_listener,
771                     &handle_notification_event, client->con_handle, &characteristic);
772 
773                 client->state = HIDS_CLIENT_STATE_CONNECTED;
774                 hids_emit_connection_established(client, ERROR_CODE_SUCCESS);
775             }
776             UNUSED(att_status);
777             break;
778 
779 
780         case HIDS_CLIENT_W2_SEND_REPORT:
781 
782 #ifdef ENABLE_TESTING_SUPPORT
783             printf("    Send report [%d, %d, 0x%04X]:\n",
784                 client->report_index,
785                 client->reports[client->report_index].service_index, client->reports[client->report_index].value_handle);
786 #endif
787 
788             client->state = HIDS_CLIENT_STATE_CONNECTED;
789 
790             att_status = gatt_client_write_value_of_characteristic_without_response(client->con_handle,
791                 client->reports[client->report_index].value_handle,
792                 client->report_len, (uint8_t *)client->report);
793             UNUSED(att_status);
794             break;
795 
796         case HIDS_CLIENT_W2_SEND_GET_REPORT:
797 #ifdef ENABLE_TESTING_SUPPORT
798             printf("    Get report [ID %d, Service %d, handle 0x%04X]:\n",
799                 client->reports[client->report_index].report_id,
800                 client->reports[client->report_index].service_index, client->reports[client->report_index].value_handle);
801 #endif
802 
803             client->state = HIDS_CLIENT_W4_GET_REPORT_RESULT;
804 
805             att_status = gatt_client_read_value_of_characteristic_using_value_handle(
806                 &handle_report_event,
807                 client->con_handle,
808                 client->reports[client->report_index].value_handle);
809             UNUSED(att_status);
810             break;
811 
812 #ifdef ENABLE_TESTING_SUPPORT
813         case HIDS_CLIENT_W2_READ_CHARACTERISTIC_CONFIGURATION:
814             client->state = HIDS_CLIENT_W4_CHARACTERISTIC_CONFIGURATION_RESULT;
815 
816             // end of write marked in GATT_EVENT_QUERY_COMPLETE
817             att_status = gatt_client_read_value_of_characteristic_using_value_handle(
818                 &handle_gatt_client_event,
819                 client->con_handle,
820                 client->reports[client->report_index].ccc_handle);
821 
822             break;
823 #endif
824 
825         default:
826             break;
827     }
828 }
829 
830 static void handle_gatt_client_event(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
831     UNUSED(packet_type);
832     UNUSED(channel);
833     UNUSED(size);
834 
835     hids_client_t * client = NULL;
836     uint8_t att_status;
837     gatt_client_service_t service;
838     gatt_client_characteristic_t characteristic;
839     gatt_client_characteristic_descriptor_t characteristic_descriptor;
840 
841     // hids_client_report_t * boot_keyboard_report;
842     // hids_client_report_t * boot_mouse_report;
843     const uint8_t * characteristic_descriptor_value;
844     uint8_t i;
845     uint8_t report_index;
846 
847     const uint8_t * descriptor_value;
848     uint16_t descriptor_value_len;
849 
850     switch(hci_event_packet_get_type(packet)){
851         case GATT_EVENT_SERVICE_QUERY_RESULT:
852             client = hids_get_client_for_con_handle(gatt_event_service_query_result_get_handle(packet));
853             btstack_assert(client != NULL);
854 
855             if (client->state != HIDS_CLIENT_STATE_W4_SERVICE_RESULT) {
856                 hids_emit_connection_established(client, GATT_CLIENT_IN_WRONG_STATE);
857                 hids_finalize_client(client);
858                 break;
859             }
860 
861             if (client->num_instances < MAX_NUM_HID_SERVICES){
862                 uint8_t index = client->num_instances;
863                 gatt_event_service_query_result_get_service(packet, &service);
864                 client->services[index].start_handle = service.start_group_handle;
865                 client->services[index].end_handle = service.end_group_handle;
866                 client->num_instances++;
867 
868 #ifdef ENABLE_TESTING_SUPPORT
869                 printf("HID Service: start handle 0x%04X, end handle 0x%04X\n", client->services[index].start_handle, client->services[index].end_handle);
870 #endif
871                 hids_client_descriptor_storage_init(client, index);
872             }  else {
873                 log_info("%d hid services found, only first %d can be stored, increase MAX_NUM_HID_SERVICES", client->num_instances + 1, MAX_NUM_HID_SERVICES);
874             }
875             break;
876 
877         case GATT_EVENT_CHARACTERISTIC_QUERY_RESULT:
878             client = hids_get_client_for_con_handle(gatt_event_characteristic_query_result_get_handle(packet));
879             btstack_assert(client != NULL);
880             gatt_event_characteristic_query_result_get_characteristic(packet, &characteristic);
881 
882             report_index = HIDS_CLIENT_INVALID_REPORT_INDEX;
883             if (client->state == HIDS_CLIENT_STATE_W4_EXTERNAL_REPORT_CHARACTERISTIC_RESULT){
884                 if (!external_report_index_for_uuid_exists(client, characteristic.uuid16)){
885                     break;
886                 }
887             }
888 
889             switch (characteristic.uuid16){
890                 case ORG_BLUETOOTH_CHARACTERISTIC_PROTOCOL_MODE:
891                     client->protocol_mode_value_handle = characteristic.value_handle;
892                     break;
893 
894                 case ORG_BLUETOOTH_CHARACTERISTIC_BOOT_KEYBOARD_INPUT_REPORT:
895                     report_index = hids_client_add_characteristic(client, &characteristic, HID_BOOT_MODE_KEYBOARD_ID, HID_REPORT_TYPE_INPUT, true);
896                     break;
897 
898                 case ORG_BLUETOOTH_CHARACTERISTIC_BOOT_MOUSE_INPUT_REPORT:
899                     report_index = hids_client_add_characteristic(client, &characteristic, HID_BOOT_MODE_MOUSE_ID, HID_REPORT_TYPE_INPUT, true);
900                     break;
901 
902                 case ORG_BLUETOOTH_CHARACTERISTIC_BOOT_KEYBOARD_OUTPUT_REPORT:
903                     report_index = hids_client_add_characteristic(client, &characteristic, HID_BOOT_MODE_KEYBOARD_ID, HID_REPORT_TYPE_OUTPUT, false);
904                     break;
905 
906                 case ORG_BLUETOOTH_CHARACTERISTIC_REPORT:
907                     report_index = hids_client_add_characteristic(client, &characteristic, HID_REPORT_MODE_REPORT_ID, HID_REPORT_TYPE_RESERVED, false);
908                     break;
909 
910                 case ORG_BLUETOOTH_CHARACTERISTIC_REPORT_MAP:
911                     client->services[client->service_index].report_map_value_handle = characteristic.value_handle;
912                     client->services[client->service_index].report_map_end_handle = characteristic.end_handle;
913                     break;
914 
915                 case ORG_BLUETOOTH_CHARACTERISTIC_HID_INFORMATION:
916                     break;
917 
918                 case ORG_BLUETOOTH_CHARACTERISTIC_HID_CONTROL_POINT:
919                     break;
920 
921                 default:
922 #ifdef ENABLE_TESTING_SUPPORT
923                     printf("    TODO: Found external characteristic 0x%04X\n", characteristic.uuid16);
924 #endif
925                     return;
926             }
927 
928 #ifdef ENABLE_TESTING_SUPPORT
929             printf("HID Characteristic %s:  \n    Attribute Handle 0x%04X, Properties 0x%02X, Handle 0x%04X, UUID 0x%04X, service %d",
930                 hid_characteristic_name(characteristic.uuid16),
931                 characteristic.start_handle,
932                 characteristic.properties,
933                 characteristic.value_handle, characteristic.uuid16,
934                 client->service_index);
935 
936             if (report_index != HIDS_CLIENT_INVALID_REPORT_INDEX){
937                 printf(", report index 0x%02X", report_index);
938             }
939             printf("\n");
940 #endif
941             break;
942 
943         case GATT_EVENT_LONG_CHARACTERISTIC_VALUE_QUERY_RESULT:
944             // Map Report characteristic value == HID Descriptor
945             client = hids_get_client_for_con_handle(gatt_event_long_characteristic_value_query_result_get_handle(packet));
946             btstack_assert(client != NULL);
947 
948             descriptor_value = gatt_event_long_characteristic_value_query_result_get_value(packet);
949             descriptor_value_len = gatt_event_long_characteristic_value_query_result_get_value_length(packet);
950 
951 #ifdef ENABLE_TESTING_SUPPORT
952             // printf("Report Map HID Desc [%d] for service %d\n", descriptor_len, client->service_index);
953             printf_hexdump(descriptor_value, descriptor_value_len);
954 #endif
955             for (i = 0; i < descriptor_value_len; i++){
956                 bool stored = hids_client_descriptor_storage_store(client, client->service_index, descriptor_value[i]);
957                 if (!stored){
958                     client->services[client->service_index].hid_descriptor_status = ERROR_CODE_MEMORY_CAPACITY_EXCEEDED;
959                     break;
960                 }
961             }
962             break;
963 
964         case GATT_EVENT_ALL_CHARACTERISTIC_DESCRIPTORS_QUERY_RESULT:
965             client = hids_get_client_for_con_handle(gatt_event_all_characteristic_descriptors_query_result_get_handle(packet));
966             btstack_assert(client != NULL);
967             gatt_event_all_characteristic_descriptors_query_result_get_characteristic_descriptor(packet, &characteristic_descriptor);
968 
969             switch (client->state) {
970                 case HIDS_CLIENT_STATE_W4_REPORT_MAP_CHARACTERISTIC_DESCRIPTORS_RESULT:
971                     // setup for descriptor value query
972                     if (characteristic_descriptor.uuid16 == ORG_BLUETOOTH_DESCRIPTOR_EXTERNAL_REPORT_REFERENCE){
973                         report_index = hids_client_add_external_report(client, &characteristic_descriptor);
974 
975 #ifdef ENABLE_TESTING_SUPPORT
976                         if (report_index != HIDS_CLIENT_INVALID_REPORT_INDEX){
977                             printf("    External Report Reference Characteristic Descriptor: Handle 0x%04X, UUID 0x%04X, service %d, report index 0x%02X\n",
978                                 characteristic_descriptor.handle,
979                                 characteristic_descriptor.uuid16,
980                                 client->service_index, report_index);
981                         }
982 #endif
983                     }
984                     break;
985                 case HIDS_CLIENT_STATE_W4_REPORT_FOUND:
986                     // setup for descriptor value query
987                     if (characteristic_descriptor.uuid16 == ORG_BLUETOOTH_DESCRIPTOR_REPORT_REFERENCE){
988                         client->descriptor_handle = characteristic_descriptor.handle;
989 #ifdef ENABLE_TESTING_SUPPORT
990                         printf("    Report Characteristic Report Reference Characteristic Descriptor:  Handle 0x%04X, UUID 0x%04X\n",
991                             characteristic_descriptor.handle,
992                             characteristic_descriptor.uuid16);
993 #endif
994                     }
995 
996 #ifdef ENABLE_TESTING_SUPPORT
997                     if (characteristic_descriptor.uuid16 == ORG_BLUETOOTH_DESCRIPTOR_GATT_CLIENT_CHARACTERISTIC_CONFIGURATION){
998                         client->reports[client->report_index].ccc_handle = characteristic_descriptor.handle;
999                         printf("    Report Client Characteristic Configuration Descriptor: Handle 0x%04X, UUID 0x%04X\n",
1000                             characteristic_descriptor.handle,
1001                             characteristic_descriptor.uuid16);
1002                     }
1003 #endif
1004                     break;
1005 
1006                 default:
1007                     break;
1008             }
1009             break;
1010 
1011 #ifdef ENABLE_TESTING_SUPPORT
1012         case GATT_EVENT_CHARACTERISTIC_VALUE_QUERY_RESULT:
1013             client = hids_get_client_for_con_handle(gatt_event_characteristic_value_query_result_get_handle(packet));
1014             btstack_assert(client != NULL);
1015 
1016             printf("    Received CCC value: ");
1017             printf_hexdump(gatt_event_characteristic_value_query_result_get_value(packet),  gatt_event_characteristic_value_query_result_get_value_length(packet));
1018             break;
1019 #endif
1020 
1021         case GATT_EVENT_CHARACTERISTIC_DESCRIPTOR_QUERY_RESULT:
1022             client = hids_get_client_for_con_handle(gatt_event_characteristic_descriptor_query_result_get_handle(packet));
1023             btstack_assert(client != NULL);
1024 
1025             if (gatt_event_characteristic_descriptor_query_result_get_descriptor_length(packet) != 2){
1026                 break;
1027             }
1028 
1029             characteristic_descriptor_value = gatt_event_characteristic_descriptor_query_result_get_descriptor(packet);
1030             switch (client->state) {
1031                 case HIDS_CLIENT_STATE_W4_REPORT_MAP_EXTERNAL_REPORT_REFERENCE_UUID:
1032                     // get external report characteristic uuid
1033                     report_index = find_external_report_index_for_value_handle(client, gatt_event_characteristic_descriptor_query_result_get_descriptor_handle(packet));
1034                     if (report_index != HIDS_CLIENT_INVALID_REPORT_INDEX){
1035                         client->external_reports[report_index].external_report_reference_uuid = little_endian_read_16(characteristic_descriptor_value, 0);
1036 #ifdef ENABLE_TESTING_SUPPORT
1037                         printf("    Update external_report_reference_uuid of report index 0x%02X, service index 0x%02X, UUID 0x%02X\n",
1038                             report_index, client->service_index, client->external_reports[report_index].external_report_reference_uuid);
1039 #endif
1040                     }
1041                     break;
1042 
1043                 case HIDS_CLIENT_STATE_W4_REPORT_ID_AND_TYPE:
1044 
1045                     if (client->report_index != HIDS_CLIENT_INVALID_REPORT_INDEX){
1046                         client->reports[client->report_index].report_id = characteristic_descriptor_value[0];
1047                         client->reports[client->report_index].report_type = (hid_report_type_t)characteristic_descriptor_value[1];
1048     #ifdef ENABLE_TESTING_SUPPORT
1049                         printf("    Update report ID and type [%d, %d] of report index 0x%02X, service index 0x%02X\n",
1050                             client->reports[client->report_index].report_id,
1051                             client->reports[client->report_index].report_type,
1052                             client->report_index, client->service_index);
1053     #endif
1054                     }
1055                     break;
1056 
1057                 default:
1058                     break;
1059             }
1060             break;
1061 
1062         case GATT_EVENT_QUERY_COMPLETE:
1063             client = hids_get_client_for_con_handle(gatt_event_query_complete_get_handle(packet));
1064             btstack_assert(client != NULL);
1065 
1066             att_status = gatt_event_query_complete_get_att_status(packet);
1067 
1068             switch (client->state){
1069                 case HIDS_CLIENT_STATE_W4_SERVICE_RESULT:
1070                     if (att_status != ATT_ERROR_SUCCESS){
1071                         hids_emit_connection_established(client, att_status);
1072                         hids_finalize_client(client);
1073                         break;
1074                     }
1075 
1076                     if (client->num_instances == 0){
1077                         hids_emit_connection_established(client, ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE);
1078                         hids_finalize_client(client);
1079                         break;
1080                     }
1081 
1082                     client->service_index = 0;
1083                     client->state = HIDS_CLIENT_STATE_W2_QUERY_CHARACTERISTIC;
1084                     break;
1085 
1086                 case HIDS_CLIENT_STATE_W4_CHARACTERISTIC_RESULT:
1087                     if (att_status != ATT_ERROR_SUCCESS){
1088                         hids_emit_connection_established(client, att_status);
1089                         hids_finalize_client(client);
1090                         break;
1091                     }
1092 
1093                     if ((client->service_index + 1) < client->num_instances){
1094                         // discover characteristics of next service
1095                         client->service_index++;
1096                         client->state = HIDS_CLIENT_STATE_W2_QUERY_CHARACTERISTIC;
1097                         break;
1098                     }
1099 
1100                     switch (client->required_protocol_mode){
1101                         case HID_PROTOCOL_MODE_REPORT:
1102                             client->protocol_mode = HID_PROTOCOL_MODE_REPORT;
1103                             if (hid_clients_has_reports_in_report_mode(client)){
1104                                 client->protocol_mode = HID_PROTOCOL_MODE_REPORT;
1105                                 break;
1106                             }
1107                             hids_emit_connection_established(client, att_status);
1108                             hids_finalize_client(client);
1109                             return;
1110 
1111                         case HID_PROTOCOL_MODE_REPORT_WITH_FALLBACK_TO_BOOT:
1112                             if (hid_clients_has_reports_in_report_mode(client)){
1113                                 client->protocol_mode = HID_PROTOCOL_MODE_REPORT;
1114                                 break;
1115                             }
1116                             if (hid_clients_has_reports_in_boot_mode(client)){
1117                                 if (client->protocol_mode_value_handle != 0){
1118                                     client->state = HIDS_CLIENT_STATE_W2_SET_BOOT_PROTOCOL_MODE;
1119                                     break;
1120                                 }
1121                                 hids_emit_connection_established(client, att_status);
1122                                 hids_finalize_client(client);
1123                                 return;
1124                             }
1125                             break;
1126                         default:
1127                             if (hid_clients_has_reports_in_boot_mode(client)){
1128                                 if (client->protocol_mode_value_handle != 0){
1129                                     client->state = HIDS_CLIENT_STATE_W2_SET_BOOT_PROTOCOL_MODE;
1130                                     break;
1131                                 }
1132                                 hids_emit_connection_established(client, att_status);
1133                                 hids_finalize_client(client);
1134                                 return;
1135                             }
1136                             break;
1137                     }
1138 
1139                     if (client->state == HIDS_CLIENT_STATE_W2_SET_BOOT_PROTOCOL_MODE){
1140                         break;
1141                     }
1142 
1143                     // 1. we need to get HID Descriptor and
1144                     // 2. get external Report characteristics if referenced from Report Map
1145                     if (hids_client_report_map_query_init(client)){
1146                         break;
1147                     }
1148                     hids_emit_connection_established(client, ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE);
1149                     hids_finalize_client(client);
1150                     break;
1151 
1152 
1153                 // HID descriptor found
1154                 case HIDS_CLIENT_STATE_W4_REPORT_MAP_HID_DESCRIPTOR:
1155                     if (att_status != ATT_ERROR_SUCCESS){
1156                         hids_emit_connection_established(client, att_status);
1157                         hids_finalize_client(client);
1158                         break;
1159                     }
1160                     client->state = HIDS_CLIENT_STATE_W2_REPORT_MAP_DISCOVER_CHARACTERISTIC_DESCRIPTORS;
1161                     break;
1162 
1163                 // found all descriptors, check if there is one with EXTERNAL_REPORT_REFERENCE
1164                 case HIDS_CLIENT_STATE_W4_REPORT_MAP_CHARACTERISTIC_DESCRIPTORS_RESULT:
1165                     // go for next report map
1166                     if (hids_client_report_query_next_report_map(client)){
1167                         break;
1168                     }
1169 
1170                     // read UUIDS for external characteristics
1171                     if (hids_client_report_map_uuid_query_init(client)){
1172                         break;
1173                     }
1174 
1175                     // discover characteristic descriptor for all Report characteristics,
1176                     // then read value of characteristic descriptor to get Report ID
1177                     if (hids_client_report_query_init(client)){
1178                         break;
1179                     }
1180 
1181                     hids_emit_connection_established(client, ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE);
1182                     hids_finalize_client(client);
1183                     break;
1184 
1185                 case HIDS_CLIENT_STATE_W4_REPORT_MAP_EXTERNAL_REPORT_REFERENCE_UUID:
1186                     // go for next map report
1187                     if (hids_client_report_query_next_report_map_uuid(client)){
1188                         break;
1189                     }
1190 
1191                     // update external characteristics with correct value handle and end handle
1192                     client->state = HIDS_CLIENT_STATE_W2_DISCOVER_EXTERNAL_REPORT_CHARACTERISTIC;
1193                     break;
1194 
1195                 case HIDS_CLIENT_STATE_W4_EXTERNAL_REPORT_CHARACTERISTIC_RESULT:
1196                     // discover characteristic descriptor for all Report characteristics,
1197                     // then read value of characteristic descriptor to get Report ID
1198                     if (hids_client_report_query_init(client)){
1199                         break;
1200                     }
1201 
1202                     hids_emit_connection_established(client, ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE);
1203                     hids_finalize_client(client);
1204                     break;
1205 
1206                 case HIDS_CLIENT_STATE_W4_REPORT_FOUND:
1207                     if (client->descriptor_handle != 0){
1208                         client->state = HIDS_CLIENT_STATE_W2_READ_REPORT_ID_AND_TYPE;
1209                         break;
1210                     }
1211 
1212                     // go for next report
1213                     if (hids_client_report_query_next_report(client)){
1214                         break;
1215                     }
1216                     client->state = HIDS_CLIENT_STATE_CONNECTED;
1217                     hids_emit_connection_established(client, ERROR_CODE_SUCCESS);
1218                     break;
1219 
1220                 case HIDS_CLIENT_STATE_W4_REPORT_ID_AND_TYPE:
1221                     // go for next report
1222                     if (hids_client_report_query_next_report(client)){
1223                         break;
1224                     }
1225                     if (hids_client_report_notifications_init(client)){
1226                         break;
1227                     }
1228                     client->state = HIDS_CLIENT_STATE_CONNECTED;
1229                     hids_emit_connection_established(client, ERROR_CODE_SUCCESS);
1230                     break;
1231 
1232                 case HIDS_CLIENT_STATE_W4_INPUT_REPORTS_ENABLED:
1233                     if (hids_client_report_next_notification_report_index(client)){
1234                         break;
1235                     }
1236                     client->state = HIDS_CLIENT_STATE_CONNECTED;
1237                     hids_emit_connection_established(client, ERROR_CODE_SUCCESS);
1238                     break;
1239 #ifdef ENABLE_TESTING_SUPPORT
1240                 case HIDS_CLIENT_W4_CHARACTERISTIC_CONFIGURATION_RESULT:
1241                     client->state = HIDS_CLIENT_W2_SEND_GET_REPORT;
1242                     break;
1243 #endif
1244                 default:
1245                     break;
1246             }
1247             break;
1248 
1249         default:
1250             break;
1251     }
1252 
1253     if (client != NULL){
1254         hids_run_for_client(client);
1255     }
1256 }
1257 
1258 uint8_t hids_client_connect(hci_con_handle_t con_handle, btstack_packet_handler_t packet_handler, hid_protocol_mode_t protocol_mode, uint16_t * hids_cid){
1259     btstack_assert(packet_handler != NULL);
1260 
1261     hids_client_t * client = hids_get_client_for_con_handle(con_handle);
1262     if (client != NULL){
1263         return ERROR_CODE_COMMAND_DISALLOWED;
1264     }
1265 
1266     uint16_t cid = hids_get_next_cid();
1267     if (hids_cid != NULL) {
1268         *hids_cid = cid;
1269     }
1270 
1271     client = hids_create_client(con_handle, cid);
1272     if (client == NULL) {
1273         return BTSTACK_MEMORY_ALLOC_FAILED;
1274     }
1275 
1276     client->required_protocol_mode = protocol_mode;
1277     client->client_handler = packet_handler;
1278     client->state = HIDS_CLIENT_STATE_W2_QUERY_SERVICE;
1279 
1280     hids_run_for_client(client);
1281     return ERROR_CODE_SUCCESS;
1282 }
1283 
1284 uint8_t hids_client_disconnect(uint16_t hids_cid){
1285     hids_client_t * client = hids_get_client_for_cid(hids_cid);
1286     if (client == NULL){
1287         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1288     }
1289     // finalize connection
1290     hids_finalize_client(client);
1291     return ERROR_CODE_SUCCESS;
1292 }
1293 
1294 uint8_t hids_client_send_report(uint16_t hids_cid, uint8_t report_id, const uint8_t * report, uint8_t report_len){
1295     hids_client_t * client = hids_get_client_for_cid(hids_cid);
1296     if (client == NULL){
1297         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1298     }
1299 
1300     if (client->state != HIDS_CLIENT_STATE_CONNECTED) {
1301         return ERROR_CODE_COMMAND_DISALLOWED;
1302     }
1303 
1304     uint8_t report_index = find_report_index_for_report_id_and_type(client, report_id, HID_REPORT_TYPE_OUTPUT);
1305 
1306     if (report_index == HIDS_CLIENT_INVALID_REPORT_INDEX){
1307         return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
1308     }
1309 
1310     uint16_t mtu;
1311     uint8_t status = gatt_client_get_mtu(client->con_handle, &mtu);
1312 
1313     if (status != ERROR_CODE_SUCCESS){
1314         return status;
1315     }
1316 
1317     if (mtu - 2 < report_len){
1318         return ERROR_CODE_PARAMETER_OUT_OF_MANDATORY_RANGE;
1319     }
1320 
1321     client->state = HIDS_CLIENT_W2_SEND_REPORT;
1322     client->report_index = report_index;
1323     client->report = report;
1324     client->report_len = report_len;
1325 
1326     hids_run_for_client(client);
1327     return ERROR_CODE_SUCCESS;
1328 }
1329 
1330 uint8_t hids_client_send_get_report(uint16_t hids_cid, uint8_t report_id){
1331     hids_client_t * client = hids_get_client_for_cid(hids_cid);
1332     if (client == NULL){
1333         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1334     }
1335 
1336     if (client->state != HIDS_CLIENT_STATE_CONNECTED) {
1337         return ERROR_CODE_COMMAND_DISALLOWED;
1338     }
1339 
1340     uint8_t report_index = find_report_index_for_report_id(client, report_id);
1341     if (report_index == HIDS_CLIENT_INVALID_REPORT_INDEX){
1342         return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
1343     }
1344 
1345     client->report_index = report_index;
1346 
1347 #ifdef ENABLE_TESTING_SUPPORT
1348     client->state = HIDS_CLIENT_W2_READ_CHARACTERISTIC_CONFIGURATION;
1349 #else
1350     client->state = HIDS_CLIENT_W2_SEND_GET_REPORT;
1351 #endif
1352     hids_run_for_client(client);
1353     return ERROR_CODE_SUCCESS;
1354 }
1355 
1356 
1357 void hids_client_init(uint8_t * hid_descriptor_storage, uint16_t hid_descriptor_storage_len){
1358     hids_client_descriptor_storage = hid_descriptor_storage;
1359     hids_client_descriptor_storage_len = hid_descriptor_storage_len;
1360 }
1361 
1362 void hids_client_deinit(void){}
1363