xref: /btstack/src/classic/avrcp.c (revision b45b7749fd0a3efec18073ae84f893078d0216d0)
1 /*
2  * Copyright (C) 2016 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__ "avrcp.c"
39 
40 #include <stdint.h>
41 #include <string.h>
42 
43 #include "bluetooth_psm.h"
44 #include "bluetooth_sdp.h"
45 #include "btstack_debug.h"
46 #include "btstack_event.h"
47 #include "btstack_memory.h"
48 #include "classic/sdp_client.h"
49 #include "classic/sdp_util.h"
50 #include "classic/avrcp.h"
51 
52 
53 typedef struct {
54     uint8_t  parse_sdp_record;
55     uint32_t record_id;
56     uint16_t avrcp_cid;
57     uint16_t avrcp_l2cap_psm;
58     uint16_t avrcp_version;
59 
60     uint16_t browsing_l2cap_psm;
61     uint16_t browsing_version;
62 } avrcp_sdp_query_context_t;
63 
64 
65 static void avrcp_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
66 
67 static const char * default_avrcp_controller_service_name = "BTstack AVRCP Controller Service";
68 static const char * default_avrcp_controller_service_provider_name = "BTstack AVRCP Controller Service Provider";
69 static const char * default_avrcp_target_service_name = "BTstack AVRCP Target Service";
70 static const char * default_avrcp_target_service_provider_name = "BTstack AVRCP Target Service Provider";
71 
72 static uint16_t  avrcp_cid_counter;
73 
74 static btstack_context_callback_registration_t avrcp_handle_sdp_client_query_request;
75 
76 static avrcp_sdp_query_context_t sdp_query_context;
77 
78 static btstack_packet_handler_t avrcp_callback;
79 
80 static uint8_t   attribute_value[45];
81 static const unsigned int attribute_value_buffer_size = sizeof(attribute_value);
82 
83 static btstack_linked_list_t connections;
84 static btstack_packet_handler_t avrcp_controller_packet_handler;
85 static btstack_packet_handler_t avrcp_target_packet_handler;
86 static bool l2cap_service_registered = false;
87 
88 static const char * avrcp_subunit_type_name[] = {
89     "MONITOR", "AUDIO", "PRINTER", "DISC", "TAPE_RECORDER_PLAYER", "TUNER",
90     "CA", "CAMERA", "RESERVED", "PANEL", "BULLETIN_BOARD", "CAMERA_STORAGE",
91     "VENDOR_UNIQUE", "RESERVED_FOR_ALL_SUBUNIT_TYPES",
92     "EXTENDED_TO_NEXT_BYTE", "UNIT", "ERROR"
93 };
94 
95 const char * avrcp_subunit2str(uint16_t index){
96     if (index <= 11) return avrcp_subunit_type_name[index];
97     if ((index >= 0x1C) && (index <= 0x1F)) return avrcp_subunit_type_name[index - 0x10];
98     return avrcp_subunit_type_name[16];
99 }
100 
101 static const char * avrcp_event_name[] = {
102     "ERROR", "PLAYBACK_STATUS_CHANGED",
103     "TRACK_CHANGED", "TRACK_REACHED_END", "TRACK_REACHED_START",
104     "PLAYBACK_POS_CHANGED", "BATT_STATUS_CHANGED", "SYSTEM_STATUS_CHANGED",
105     "PLAYER_APPLICATION_SETTING_CHANGED", "NOW_PLAYING_CONTENT_CHANGED",
106     "AVAILABLE_PLAYERS_CHANGED", "ADDRESSED_PLAYER_CHANGED", "UIDS_CHANGED", "VOLUME_CHANGED"
107 };
108 const char * avrcp_event2str(uint16_t index){
109     if (index <= 0x0d) return avrcp_event_name[index];
110     return avrcp_event_name[0];
111 }
112 
113 static const char * avrcp_operation_name[] = {
114     "SKIP", NULL, NULL, NULL, NULL,
115     "VOLUME_UP", "VOLUME_DOWN", "MUTE", "PLAY", "STOP", "PAUSE", NULL,
116     "REWIND", "FAST_FORWARD", NULL, "FORWARD", "BACKWARD" // 0x4C
117 };
118 
119 const char * avrcp_operation2str(uint8_t operation_id){
120     char * name = NULL;
121     if ((operation_id >= AVRCP_OPERATION_ID_SKIP) && (operation_id <= AVRCP_OPERATION_ID_BACKWARD)){
122         name = (char *)avrcp_operation_name[operation_id - AVRCP_OPERATION_ID_SKIP];
123     }
124     if (name == NULL){
125         static char buffer[13];
126         snprintf(buffer, sizeof(buffer), "Unknown 0x%02x", operation_id);
127         buffer[sizeof(buffer)-1] = 0;
128         return buffer;
129     } else {
130         return name;
131     }
132 }
133 
134 static const char * avrcp_media_attribute_id_name[] = {
135     "NONE", "TITLE", "ARTIST", "ALBUM", "TRACK", "TOTAL TRACKS", "GENRE", "SONG LENGTH"
136 };
137 const char * avrcp_attribute2str(uint8_t index){
138     if ((index >= 1) && (index <= 7)) return avrcp_media_attribute_id_name[index];
139     return avrcp_media_attribute_id_name[0];
140 }
141 
142 static const char * avrcp_play_status_name[] = {
143     "STOPPED", "PLAYING", "PAUSED", "FORWARD SEEK", "REVERSE SEEK",
144     "ERROR" // 0xFF
145 };
146 const char * avrcp_play_status2str(uint8_t index){
147     if ((index >= 1) && (index <= 4)) return avrcp_play_status_name[index];
148     return avrcp_play_status_name[5];
149 }
150 
151 static const char * avrcp_ctype_name[] = {
152     "CONTROL",
153     "STATUS",
154     "SPECIFIC_INQUIRY",
155     "NOTIFY",
156     "GENERAL_INQUIRY",
157     "RESERVED5",
158     "RESERVED6",
159     "RESERVED7",
160     "NOT IMPLEMENTED IN REMOTE",
161     "ACCEPTED BY REMOTE",
162     "REJECTED BY REMOTE",
163     "IN_TRANSITION",
164     "IMPLEMENTED_STABLE",
165     "CHANGED_STABLE",
166     "RESERVED",
167     "INTERIM"
168 };
169 const char * avrcp_ctype2str(uint8_t index){
170     if (index < sizeof(avrcp_ctype_name)){
171         return avrcp_ctype_name[index];
172     }
173     return "NONE";
174 }
175 
176 static const char * avrcp_shuffle_mode_name[] = {
177     "SHUFFLE OFF",
178     "SHUFFLE ALL TRACKS",
179     "SHUFFLE GROUP"
180 };
181 
182 const char * avrcp_shuffle2str(uint8_t index){
183     if ((index >= 1) && (index <= 3)) return avrcp_shuffle_mode_name[index-1];
184     return "NONE";
185 }
186 
187 static const char * avrcp_repeat_mode_name[] = {
188     "REPEAT OFF",
189     "REPEAT SINGLE TRACK",
190     "REPEAT ALL TRACKS",
191     "REPEAT GROUP"
192 };
193 
194 const char * avrcp_repeat2str(uint8_t index){
195     if ((index >= 1) && (index <= 4)) return avrcp_repeat_mode_name[index-1];
196     return "NONE";
197 }
198 
199 btstack_linked_list_t avrcp_get_connections(void){
200     return connections;
201 }
202 
203 uint8_t avrcp_cmd_opcode(uint8_t *packet, uint16_t size){
204     uint8_t cmd_opcode_index = 5;
205     if (cmd_opcode_index > size) return AVRCP_CMD_OPCODE_UNDEFINED;
206     return packet[cmd_opcode_index];
207 }
208 
209 void avrcp_create_sdp_record(uint8_t controller, uint8_t * service, uint32_t service_record_handle, uint8_t browsing, uint16_t supported_features,
210     const char * service_name, const char * service_provider_name){
211     uint8_t* attribute;
212     de_create_sequence(service);
213 
214     // 0x0000 "Service Record Handle"
215     de_add_number(service, DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_SERVICE_RECORD_HANDLE);
216     de_add_number(service, DE_UINT, DE_SIZE_32, service_record_handle);
217 
218     // 0x0001 "Service Class ID List"
219     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_SERVICE_CLASS_ID_LIST);
220     attribute = de_push_sequence(service);
221     {
222         if (controller){
223             de_add_number(attribute, DE_UUID, DE_SIZE_16, BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL);
224             de_add_number(attribute, DE_UUID, DE_SIZE_16, BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL_CONTROLLER);
225         } else {
226             de_add_number(attribute, DE_UUID, DE_SIZE_16, BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL_TARGET);
227         }
228     }
229     de_pop_sequence(service, attribute);
230 
231     // 0x0004 "Protocol Descriptor List"
232     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_PROTOCOL_DESCRIPTOR_LIST);
233     attribute = de_push_sequence(service);
234     {
235         uint8_t* l2cpProtocol = de_push_sequence(attribute);
236         {
237             de_add_number(l2cpProtocol,  DE_UUID, DE_SIZE_16, BLUETOOTH_PROTOCOL_L2CAP);
238             de_add_number(l2cpProtocol,  DE_UINT, DE_SIZE_16, BLUETOOTH_PSM_AVCTP);
239         }
240         de_pop_sequence(attribute, l2cpProtocol);
241 
242         uint8_t* avctpProtocol = de_push_sequence(attribute);
243         {
244             de_add_number(avctpProtocol,  DE_UUID, DE_SIZE_16, BLUETOOTH_PROTOCOL_AVCTP);  // avctpProtocol_service
245             de_add_number(avctpProtocol,  DE_UINT, DE_SIZE_16,  0x0104);    // version
246         }
247         de_pop_sequence(attribute, avctpProtocol);
248     }
249     de_pop_sequence(service, attribute);
250 
251     // 0x0005 "Public Browse Group"
252     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_BROWSE_GROUP_LIST); // public browse group
253     attribute = de_push_sequence(service);
254     {
255         de_add_number(attribute,  DE_UUID, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_PUBLIC_BROWSE_ROOT);
256     }
257     de_pop_sequence(service, attribute);
258 
259     // 0x0009 "Bluetooth Profile Descriptor List"
260     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_BLUETOOTH_PROFILE_DESCRIPTOR_LIST);
261     attribute = de_push_sequence(service);
262     {
263         uint8_t *avrcProfile = de_push_sequence(attribute);
264         {
265             de_add_number(avrcProfile,  DE_UUID, DE_SIZE_16, BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL);
266             de_add_number(avrcProfile,  DE_UINT, DE_SIZE_16, 0x0106);
267         }
268         de_pop_sequence(attribute, avrcProfile);
269     }
270     de_pop_sequence(service, attribute);
271 
272     // 0x000d "Additional Bluetooth Profile Descriptor List"
273     if (browsing){
274         de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_ADDITIONAL_PROTOCOL_DESCRIPTOR_LISTS);
275         attribute = de_push_sequence(service);
276         {
277             uint8_t * des = de_push_sequence(attribute);
278             {
279                 uint8_t* browsing_l2cpProtocol = de_push_sequence(des);
280                 {
281                     de_add_number(browsing_l2cpProtocol,  DE_UUID, DE_SIZE_16, BLUETOOTH_PROTOCOL_L2CAP);
282                     de_add_number(browsing_l2cpProtocol,  DE_UINT, DE_SIZE_16, BLUETOOTH_PSM_AVCTP_BROWSING);
283                 }
284                 de_pop_sequence(des, browsing_l2cpProtocol);
285 
286                 uint8_t* browsing_avctpProtocol = de_push_sequence(des);
287                 {
288                     de_add_number(browsing_avctpProtocol,  DE_UUID, DE_SIZE_16, BLUETOOTH_PROTOCOL_AVCTP);  // browsing_avctpProtocol_service
289                     de_add_number(browsing_avctpProtocol,  DE_UINT, DE_SIZE_16, 0x0104);                   // version
290                 }
291                 de_pop_sequence(des, browsing_avctpProtocol);
292             }
293             de_pop_sequence(attribute, des);
294         }
295         de_pop_sequence(service, attribute);
296     }
297 
298 
299     // 0x0100 "Service Name"
300     de_add_number(service,  DE_UINT, DE_SIZE_16, 0x0100);
301     if (service_name){
302         de_add_data(service,  DE_STRING, strlen(service_name), (uint8_t *) service_name);
303     } else {
304         if (controller){
305             de_add_data(service,  DE_STRING, strlen(default_avrcp_controller_service_name), (uint8_t *) default_avrcp_controller_service_name);
306         } else {
307             de_add_data(service,  DE_STRING, strlen(default_avrcp_target_service_name), (uint8_t *) default_avrcp_target_service_name);
308         }
309     }
310 
311     // 0x0100 "Provider Name"
312     de_add_number(service,  DE_UINT, DE_SIZE_16, 0x0102);
313     if (service_provider_name){
314         de_add_data(service,  DE_STRING, strlen(service_provider_name), (uint8_t *) service_provider_name);
315     } else {
316         if (controller){
317             de_add_data(service,  DE_STRING, strlen(default_avrcp_controller_service_provider_name), (uint8_t *) default_avrcp_controller_service_provider_name);
318         } else {
319             de_add_data(service,  DE_STRING, strlen(default_avrcp_target_service_provider_name), (uint8_t *) default_avrcp_target_service_provider_name);
320         }
321     }
322 
323     // 0x0311 "Supported Features"
324     de_add_number(service, DE_UINT, DE_SIZE_16, 0x0311);
325     de_add_number(service, DE_UINT, DE_SIZE_16, supported_features);
326 }
327 
328 avrcp_connection_t * avrcp_get_connection_for_bd_addr_for_role(avrcp_role_t role, bd_addr_t addr){
329     btstack_linked_list_iterator_t it;
330     btstack_linked_list_iterator_init(&it, (btstack_linked_list_t *) &connections);
331     while (btstack_linked_list_iterator_has_next(&it)){
332         avrcp_connection_t * connection = (avrcp_connection_t *)btstack_linked_list_iterator_next(&it);
333         if (connection->role != role) continue;
334         if (memcmp(addr, connection->remote_addr, 6) != 0) continue;
335         return connection;
336     }
337     return NULL;
338 }
339 
340 avrcp_connection_t * avrcp_get_connection_for_l2cap_signaling_cid_for_role(avrcp_role_t role, uint16_t l2cap_cid){
341     btstack_linked_list_iterator_t it;
342     btstack_linked_list_iterator_init(&it, (btstack_linked_list_t *) &connections);
343     while (btstack_linked_list_iterator_has_next(&it)){
344         avrcp_connection_t * connection = (avrcp_connection_t *)btstack_linked_list_iterator_next(&it);
345         if (connection->role != role) continue;
346         if (connection->l2cap_signaling_cid != l2cap_cid) continue;
347         return connection;
348     }
349     return NULL;
350 }
351 
352 avrcp_connection_t * avrcp_get_connection_for_avrcp_cid_for_role(avrcp_role_t role, uint16_t avrcp_cid){
353     btstack_linked_list_iterator_t it;
354     btstack_linked_list_iterator_init(&it, (btstack_linked_list_t *) &connections);
355     while (btstack_linked_list_iterator_has_next(&it)){
356         avrcp_connection_t * connection = (avrcp_connection_t *)btstack_linked_list_iterator_next(&it);
357         if (connection->role != role) continue;
358         if (connection->avrcp_cid != avrcp_cid) continue;
359         return connection;
360     }
361     return NULL;
362 }
363 
364 avrcp_connection_t * avrcp_get_connection_for_browsing_cid_for_role(avrcp_role_t role, uint16_t browsing_cid){
365     btstack_linked_list_iterator_t it;
366     btstack_linked_list_iterator_init(&it, (btstack_linked_list_t *) &connections);
367     while (btstack_linked_list_iterator_has_next(&it)){
368         avrcp_connection_t * connection = (avrcp_connection_t *)btstack_linked_list_iterator_next(&it);
369         if (connection->role != role) continue;
370         if (connection->avrcp_browsing_cid != browsing_cid) continue;
371         return connection;
372     }
373     return NULL;
374 }
375 
376 avrcp_connection_t * avrcp_get_connection_for_browsing_l2cap_cid_for_role(avrcp_role_t role, uint16_t browsing_l2cap_cid){
377     btstack_linked_list_iterator_t it;
378     btstack_linked_list_iterator_init(&it, (btstack_linked_list_t *) &connections);
379     while (btstack_linked_list_iterator_has_next(&it)){
380         avrcp_connection_t * connection = (avrcp_connection_t *)btstack_linked_list_iterator_next(&it);
381         if (connection->role != role) continue;
382         if (connection->browsing_connection &&  (connection->browsing_connection->l2cap_browsing_cid != browsing_l2cap_cid)) continue;
383         return connection;
384     }
385     return NULL;
386 }
387 
388 avrcp_browsing_connection_t * avrcp_get_browsing_connection_for_l2cap_cid_for_role(avrcp_role_t role, uint16_t l2cap_cid){
389     btstack_linked_list_iterator_t it;
390     btstack_linked_list_iterator_init(&it, (btstack_linked_list_t *) &connections);
391     while (btstack_linked_list_iterator_has_next(&it)){
392         avrcp_connection_t * connection = (avrcp_connection_t *)btstack_linked_list_iterator_next(&it);
393         if (connection->role != role) continue;
394         if (connection->browsing_connection && (connection->browsing_connection->l2cap_browsing_cid != l2cap_cid)) continue;
395         return connection->browsing_connection;
396     }
397     return NULL;
398 }
399 
400 void avrcp_request_can_send_now(avrcp_connection_t * connection, uint16_t l2cap_cid){
401     connection->wait_to_send = true;
402     l2cap_request_can_send_now_event(l2cap_cid);
403 }
404 
405 uint16_t avrcp_get_next_cid(avrcp_role_t role){
406     do {
407         if (avrcp_cid_counter == 0xffff) {
408             avrcp_cid_counter = 1;
409         } else {
410             avrcp_cid_counter++;
411         }
412     } while (avrcp_get_connection_for_avrcp_cid_for_role(role, avrcp_cid_counter) !=  NULL) ;
413     return avrcp_cid_counter;
414 }
415 
416 
417 static avrcp_connection_t * avrcp_create_connection(avrcp_role_t role, bd_addr_t remote_addr){
418     avrcp_connection_t * connection = btstack_memory_avrcp_connection_get();
419     if (!connection){
420         log_error("Not enough memory to create connection for role %d", role);
421         return NULL;
422     }
423 
424     connection->state = AVCTP_CONNECTION_IDLE;
425     connection->role = role;
426 
427     connection->transaction_id = 0xFF;
428     connection->transaction_id_counter = 0;
429 
430     connection->max_num_fragments = 0xFF;
431     log_info("avrcp_create_connection, role %d", role);
432     (void)memcpy(connection->remote_addr, remote_addr, 6);
433     btstack_linked_list_add(&connections, (btstack_linked_item_t *) connection);
434     return connection;
435 }
436 
437 static void avrcp_finalize_connection(avrcp_connection_t * connection){
438     btstack_run_loop_remove_timer(&connection->retry_timer);
439     btstack_linked_list_remove(&connections, (btstack_linked_item_t*) connection);
440     btstack_memory_avrcp_connection_free(connection);
441 }
442 
443 static void avrcp_emit_connection_established(uint16_t avrcp_cid, bd_addr_t addr, hci_con_handle_t con_handle, uint8_t status){
444     btstack_assert(avrcp_callback != NULL);
445 
446     uint8_t event[14];
447     int pos = 0;
448     event[pos++] = HCI_EVENT_AVRCP_META;
449     event[pos++] = sizeof(event) - 2;
450     event[pos++] = AVRCP_SUBEVENT_CONNECTION_ESTABLISHED;
451     event[pos++] = status;
452     little_endian_store_16(event, pos, avrcp_cid);
453     pos += 2;
454     reverse_bd_addr(addr,&event[pos]);
455     pos += 6;
456     little_endian_store_16(event, pos, con_handle);
457     pos += 2;
458     (*avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
459 }
460 
461 static void avrcp_emit_connection_closed(uint16_t avrcp_cid){
462     btstack_assert(avrcp_callback != NULL);
463 
464     uint8_t event[5];
465     int pos = 0;
466     event[pos++] = HCI_EVENT_AVRCP_META;
467     event[pos++] = sizeof(event) - 2;
468     event[pos++] = AVRCP_SUBEVENT_CONNECTION_RELEASED;
469     little_endian_store_16(event, pos, avrcp_cid);
470     pos += 2;
471     (*avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
472 }
473 
474 uint16_t avrcp_sdp_query_browsing_l2cap_psm(void){
475     return sdp_query_context.browsing_l2cap_psm;
476 }
477 
478 void avrcp_handle_sdp_client_query_attribute_value(uint8_t *packet){
479     des_iterator_t des_list_it;
480     des_iterator_t prot_it;
481 
482     // Handle new SDP record
483     if (sdp_event_query_attribute_byte_get_record_id(packet) != sdp_query_context.record_id) {
484         sdp_query_context.record_id = sdp_event_query_attribute_byte_get_record_id(packet);
485         sdp_query_context.parse_sdp_record = 0;
486         // log_info("SDP Record: Nr: %d", record_id);
487     }
488 
489     if (sdp_event_query_attribute_byte_get_attribute_length(packet) <= attribute_value_buffer_size) {
490         attribute_value[sdp_event_query_attribute_byte_get_data_offset(packet)] = sdp_event_query_attribute_byte_get_data(packet);
491 
492         if ((uint16_t)(sdp_event_query_attribute_byte_get_data_offset(packet)+1) == sdp_event_query_attribute_byte_get_attribute_length(packet)) {
493             switch(sdp_event_query_attribute_byte_get_attribute_id(packet)) {
494                 case BLUETOOTH_ATTRIBUTE_SERVICE_CLASS_ID_LIST:
495                     if (de_get_element_type(attribute_value) != DE_DES) break;
496                     for (des_iterator_init(&des_list_it, attribute_value); des_iterator_has_more(&des_list_it); des_iterator_next(&des_list_it)) {
497                         uint8_t * element = des_iterator_get_element(&des_list_it);
498                         if (de_get_element_type(element) != DE_UUID) continue;
499                         uint32_t uuid = de_get_uuid32(element);
500                         switch (uuid){
501                             case BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL_TARGET:
502                             case BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL:
503                             case BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL_CONTROLLER:
504                                 sdp_query_context.parse_sdp_record = 1;
505                                 break;
506                             default:
507                                 break;
508                         }
509                     }
510                     break;
511 
512                 case BLUETOOTH_ATTRIBUTE_PROTOCOL_DESCRIPTOR_LIST: {
513                     if (!sdp_query_context.parse_sdp_record) break;
514                     // log_info("SDP Attribute: 0x%04x", sdp_event_query_attribute_byte_get_attribute_id(packet));
515                     for (des_iterator_init(&des_list_it, attribute_value); des_iterator_has_more(&des_list_it); des_iterator_next(&des_list_it)) {
516                         uint8_t       *des_element;
517                         uint8_t       *element;
518                         uint32_t       uuid;
519 
520                         if (des_iterator_get_type(&des_list_it) != DE_DES) continue;
521 
522                         des_element = des_iterator_get_element(&des_list_it);
523                         des_iterator_init(&prot_it, des_element);
524                         element = des_iterator_get_element(&prot_it);
525 
526                         if (de_get_element_type(element) != DE_UUID) continue;
527 
528                         uuid = de_get_uuid32(element);
529                         des_iterator_next(&prot_it);
530                         switch (uuid){
531                             case BLUETOOTH_PROTOCOL_L2CAP:
532                                 if (!des_iterator_has_more(&prot_it)) continue;
533                                 de_element_get_uint16(des_iterator_get_element(&prot_it), &sdp_query_context.avrcp_l2cap_psm);
534                                 break;
535                             case BLUETOOTH_PROTOCOL_AVCTP:
536                                 if (!des_iterator_has_more(&prot_it)) continue;
537                                 de_element_get_uint16(des_iterator_get_element(&prot_it), &sdp_query_context.avrcp_version);
538                                 break;
539                             default:
540                                 break;
541                         }
542                     }
543                 }
544                     break;
545                 case BLUETOOTH_ATTRIBUTE_ADDITIONAL_PROTOCOL_DESCRIPTOR_LISTS: {
546                     // log_info("SDP Attribute: 0x%04x", sdp_event_query_attribute_byte_get_attribute_id(packet));
547                     if (!sdp_query_context.parse_sdp_record) break;
548                     if (de_get_element_type(attribute_value) != DE_DES) break;
549 
550                     des_iterator_t des_list_0_it;
551                     uint8_t       *element_0;
552 
553                     des_iterator_init(&des_list_0_it, attribute_value);
554                     element_0 = des_iterator_get_element(&des_list_0_it);
555 
556                     for (des_iterator_init(&des_list_it, element_0); des_iterator_has_more(&des_list_it); des_iterator_next(&des_list_it)) {
557                         uint8_t       *des_element;
558                         uint8_t       *element;
559                         uint32_t       uuid;
560 
561                         if (des_iterator_get_type(&des_list_it) != DE_DES) continue;
562 
563                         des_element = des_iterator_get_element(&des_list_it);
564                         des_iterator_init(&prot_it, des_element);
565                         element = des_iterator_get_element(&prot_it);
566 
567                         if (de_get_element_type(element) != DE_UUID) continue;
568 
569                         uuid = de_get_uuid32(element);
570                         des_iterator_next(&prot_it);
571                         switch (uuid){
572                             case BLUETOOTH_PROTOCOL_L2CAP:
573                                 if (!des_iterator_has_more(&prot_it)) continue;
574                                 de_element_get_uint16(des_iterator_get_element(&prot_it), &sdp_query_context.browsing_l2cap_psm);
575                                 break;
576                             case BLUETOOTH_PROTOCOL_AVCTP:
577                                 if (!des_iterator_has_more(&prot_it)) continue;
578                                 de_element_get_uint16(des_iterator_get_element(&prot_it), &sdp_query_context.browsing_version);
579                                 break;
580                             default:
581                                 break;
582                         }
583                     }
584                 }
585                     break;
586                 default:
587                     break;
588             }
589         }
590     } else {
591         log_error("SDP attribute value buffer size exceeded: available %d, required %d", attribute_value_buffer_size, sdp_event_query_attribute_byte_get_attribute_length(packet));
592     }
593 }
594 
595 static void avrcp_handle_sdp_query_failed(avrcp_connection_t * connection, uint8_t status){
596     if (connection == NULL) return;
597     log_info("AVRCP: SDP query failed with status 0x%02x.", status);
598     avrcp_emit_connection_established(connection->avrcp_cid, connection->remote_addr, connection->con_handle, status);
599     avrcp_finalize_connection(connection);
600 }
601 
602 static void avrcp_handle_sdp_query_succeeded(avrcp_connection_t * connection){
603     if (connection == NULL) return;
604     connection->state = AVCTP_CONNECTION_W4_L2CAP_CONNECTED;
605     connection->avrcp_l2cap_psm = sdp_query_context.avrcp_l2cap_psm;
606     connection->browsing_version = sdp_query_context.browsing_version;
607     connection->browsing_l2cap_psm = sdp_query_context.browsing_l2cap_psm;
608 }
609 
610 static void avrcp_handle_sdp_client_query_result(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
611     UNUSED(packet_type);
612     UNUSED(channel);
613     UNUSED(size);
614 
615     bool state_ok = true;
616     avrcp_connection_t * avrcp_target_connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_TARGET, sdp_query_context.avrcp_cid);
617     if (!avrcp_target_connection || avrcp_target_connection->state != AVCTP_CONNECTION_W4_SDP_QUERY_COMPLETE) {
618         state_ok = false;
619     }
620     avrcp_connection_t * avrcp_controller_connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, sdp_query_context.avrcp_cid);
621     if (!avrcp_controller_connection || avrcp_controller_connection->state != AVCTP_CONNECTION_W4_SDP_QUERY_COMPLETE) {
622         state_ok = false;
623     }
624     if (!state_ok){
625         // something wrong, nevertheless, start next sdp query if this one is complete
626         if (hci_event_packet_get_type(packet) == SDP_EVENT_QUERY_COMPLETE){
627             (void) sdp_client_register_query_callback(&avrcp_handle_sdp_client_query_request);
628         }
629         return;
630     }
631 
632     uint8_t status;
633 
634     switch (hci_event_packet_get_type(packet)){
635         case SDP_EVENT_QUERY_ATTRIBUTE_VALUE:
636             avrcp_handle_sdp_client_query_attribute_value(packet);
637             return;
638 
639         case SDP_EVENT_QUERY_COMPLETE:
640             status = sdp_event_query_complete_get_status(packet);
641 
642             if (status != ERROR_CODE_SUCCESS){
643                 avrcp_handle_sdp_query_failed(avrcp_controller_connection, status);
644                 avrcp_handle_sdp_query_failed(avrcp_target_connection, status);
645                 break;
646             }
647 
648             if (!sdp_query_context.avrcp_l2cap_psm){
649                 avrcp_handle_sdp_query_failed(avrcp_controller_connection, SDP_SERVICE_NOT_FOUND);
650                 avrcp_handle_sdp_query_failed(avrcp_target_connection, SDP_SERVICE_NOT_FOUND);
651                 break;
652             }
653 
654             avrcp_handle_sdp_query_succeeded(avrcp_controller_connection);
655             avrcp_handle_sdp_query_succeeded(avrcp_target_connection);
656 
657             l2cap_create_channel(&avrcp_packet_handler, avrcp_target_connection->remote_addr, sdp_query_context.avrcp_l2cap_psm, l2cap_max_mtu(), NULL);
658             break;
659 
660         default:
661             return;
662     }
663 
664     // register the SDP Query request to check if there is another connection waiting for the query
665     // ignore ERROR_CODE_COMMAND_DISALLOWED because in that case, we already have requested an SDP callback
666     (void) sdp_client_register_query_callback(&avrcp_handle_sdp_client_query_request);
667 }
668 
669 
670 static avrcp_connection_t * avrcp_handle_incoming_connection_for_role(avrcp_role_t role, avrcp_connection_t * connection, bd_addr_t event_addr, hci_con_handle_t con_handle, uint16_t local_cid, uint16_t avrcp_cid){
671     if (connection == NULL){
672         connection = avrcp_create_connection(role, event_addr);
673     }
674     if (connection) {
675         connection->state = AVCTP_CONNECTION_W4_L2CAP_CONNECTED;
676         connection->l2cap_signaling_cid = local_cid;
677         connection->avrcp_cid = avrcp_cid;
678         connection->con_handle = con_handle;
679         btstack_run_loop_remove_timer(&connection->retry_timer);
680     }
681     return connection;
682 }
683 
684 static void avrcp_handle_open_connection(avrcp_connection_t * connection, hci_con_handle_t con_handle, uint16_t local_cid, uint16_t l2cap_mtu){
685     connection->l2cap_signaling_cid = local_cid;
686     connection->l2cap_mtu = l2cap_mtu;
687     connection->con_handle = con_handle;
688     connection->incoming_declined = false;
689     connection->song_length_ms = 0xFFFFFFFF;
690     connection->song_position_ms = 0xFFFFFFFF;
691     connection->playback_status = AVRCP_PLAYBACK_STATUS_ERROR;
692     connection->state = AVCTP_CONNECTION_OPENED;
693 
694     log_info("L2CAP_EVENT_CHANNEL_OPENED avrcp_cid 0x%02x, l2cap_signaling_cid 0x%02x, role %d, state %d", connection->avrcp_cid, connection->l2cap_signaling_cid, connection->role, connection->state);
695 }
696 
697 static void avrcp_retry_timer_timeout_handler(btstack_timer_source_t * timer){
698     uint16_t avrcp_cid = (uint16_t)(uintptr_t) btstack_run_loop_get_timer_context(timer);
699     avrcp_connection_t * connection_controller = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
700     if (connection_controller == NULL) return;
701     avrcp_connection_t * connection_target = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_TARGET, avrcp_cid);
702     if (connection_target == NULL) return;
703 
704     if (connection_controller->state == AVCTP_CONNECTION_W2_L2CAP_RETRY){
705         connection_controller->state = AVCTP_CONNECTION_W4_L2CAP_CONNECTED;
706         connection_target->state = AVCTP_CONNECTION_W4_L2CAP_CONNECTED;
707         l2cap_create_channel(&avrcp_packet_handler, connection_controller->remote_addr, connection_controller->avrcp_l2cap_psm, l2cap_max_mtu(), NULL);
708     }
709 }
710 
711 static void avrcp_retry_timer_start(avrcp_connection_t * connection){
712     btstack_run_loop_set_timer_handler(&connection->retry_timer, avrcp_retry_timer_timeout_handler);
713     btstack_run_loop_set_timer_context(&connection->retry_timer, (void *)(uintptr_t)connection->avrcp_cid);
714 
715     // add some jitter/randomness to reconnect delay
716     uint32_t timeout = 100 + (btstack_run_loop_get_time_ms() & 0x7F);
717     btstack_run_loop_set_timer(&connection->retry_timer, timeout);
718 
719     btstack_run_loop_add_timer(&connection->retry_timer);
720 }
721 
722 static avrcp_frame_type_t avrcp_get_frame_type(uint8_t header){
723     return (avrcp_frame_type_t)((header & 0x02) >> 1);
724 }
725 
726 static void avrcp_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
727     UNUSED(channel);
728     UNUSED(size);
729     bd_addr_t event_addr;
730     uint16_t local_cid;
731     uint16_t l2cap_mtu;
732     uint8_t  status;
733     bool decline_connection;
734     bool outoing_active;
735     hci_con_handle_t con_handle;
736 
737     avrcp_connection_t * connection_controller;
738     avrcp_connection_t * connection_target;
739     bool can_send;
740 
741     switch (packet_type) {
742         case HCI_EVENT_PACKET:
743             switch (hci_event_packet_get_type(packet)) {
744 
745                 case L2CAP_EVENT_INCOMING_CONNECTION:
746                     btstack_assert(avrcp_controller_packet_handler != NULL);
747                     btstack_assert(avrcp_target_packet_handler != NULL);
748 
749                     l2cap_event_incoming_connection_get_address(packet, event_addr);
750                     local_cid = l2cap_event_incoming_connection_get_local_cid(packet);
751                     con_handle = l2cap_event_incoming_connection_get_handle(packet);
752 
753                     outoing_active = false;
754                     connection_target = avrcp_get_connection_for_bd_addr_for_role(AVRCP_TARGET, event_addr);
755                     if (connection_target != NULL){
756                         if (connection_target->state == AVCTP_CONNECTION_W4_L2CAP_CONNECTED){
757                             outoing_active = true;
758                             connection_target->incoming_declined = true;
759                         }
760                     }
761 
762                     connection_controller = avrcp_get_connection_for_bd_addr_for_role(AVRCP_CONTROLLER, event_addr);
763                     if (connection_controller != NULL){
764                         if (connection_controller->state == AVCTP_CONNECTION_W4_L2CAP_CONNECTED) {
765                             outoing_active = true;
766                             connection_controller->incoming_declined = true;
767                         }
768                     }
769 
770                     decline_connection = outoing_active;
771                     if (decline_connection == false){
772                         uint16_t avrcp_cid;
773                         if ((connection_controller == NULL) || (connection_target == NULL)){
774                             avrcp_cid = avrcp_get_next_cid(AVRCP_CONTROLLER);
775                         } else {
776                             avrcp_cid = connection_controller->avrcp_cid;
777                         }
778                         // create two connection objects (both)
779                         connection_target     = avrcp_handle_incoming_connection_for_role(AVRCP_TARGET, connection_target, event_addr, con_handle, local_cid, avrcp_cid);
780                         connection_controller = avrcp_handle_incoming_connection_for_role(AVRCP_CONTROLLER, connection_controller, event_addr, con_handle, local_cid, avrcp_cid);
781                         if ((connection_target == NULL) || (connection_controller == NULL)){
782                             decline_connection = true;
783                             if (connection_target) {
784                                 avrcp_finalize_connection(connection_target);
785                             }
786                             if (connection_controller) {
787                                 avrcp_finalize_connection(connection_controller);
788                             }
789                         }
790                     }
791                     if (decline_connection){
792                         l2cap_decline_connection(local_cid);
793                     } else {
794                         log_info("AVRCP: L2CAP_EVENT_INCOMING_CONNECTION local cid 0x%02x, state %d", local_cid, connection_controller->state);
795                         l2cap_accept_connection(local_cid);
796                     }
797                     break;
798 
799                 case L2CAP_EVENT_CHANNEL_OPENED:
800                     l2cap_event_channel_opened_get_address(packet, event_addr);
801                     status = l2cap_event_channel_opened_get_status(packet);
802                     local_cid = l2cap_event_channel_opened_get_local_cid(packet);
803                     l2cap_mtu = l2cap_event_channel_opened_get_remote_mtu(packet);
804                     con_handle = l2cap_event_channel_opened_get_handle(packet);
805 
806                     connection_controller = avrcp_get_connection_for_bd_addr_for_role(AVRCP_CONTROLLER, event_addr);
807                     connection_target = avrcp_get_connection_for_bd_addr_for_role(AVRCP_TARGET, event_addr);
808 
809                     // incoming: structs are already created in L2CAP_EVENT_INCOMING_CONNECTION
810                     // outgoing: structs are cteated in avrcp_connect()
811                     if ((connection_controller == NULL) || (connection_target == NULL)) {
812                         break;
813                     }
814 
815                     switch (status){
816                         case ERROR_CODE_SUCCESS:
817                             avrcp_handle_open_connection(connection_target, con_handle, local_cid, l2cap_mtu);
818                             avrcp_handle_open_connection(connection_controller, con_handle, local_cid, l2cap_mtu);
819                             avrcp_emit_connection_established(connection_controller->avrcp_cid, event_addr, con_handle, status);
820                             return;
821                         case L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_RESOURCES:
822                             if (connection_controller->incoming_declined == true){
823                                 log_info("Incoming connection was declined, and the outgoing failed");
824                                 connection_controller->state = AVCTP_CONNECTION_W2_L2CAP_RETRY;
825                                 connection_controller->incoming_declined = false;
826                                 connection_target->state = AVCTP_CONNECTION_W2_L2CAP_RETRY;
827                                 connection_target->incoming_declined = false;
828                                 avrcp_retry_timer_start(connection_controller);
829                                 return;
830                             }
831                             break;
832                         default:
833                             break;
834                     }
835                     log_info("L2CAP connection to connection %s failed. status code 0x%02x", bd_addr_to_str(event_addr), status);
836                     avrcp_emit_connection_established(connection_controller->avrcp_cid, event_addr, con_handle, status);
837                     avrcp_finalize_connection(connection_controller);
838                     avrcp_finalize_connection(connection_target);
839 
840                     break;
841 
842                 case L2CAP_EVENT_CHANNEL_CLOSED:
843                     local_cid = l2cap_event_channel_closed_get_local_cid(packet);
844 
845                     connection_controller = avrcp_get_connection_for_l2cap_signaling_cid_for_role(AVRCP_CONTROLLER, local_cid);
846                     connection_target = avrcp_get_connection_for_l2cap_signaling_cid_for_role(AVRCP_TARGET, local_cid);
847                     if ((connection_controller == NULL) || (connection_target == NULL)) {
848                         break;
849                     }
850                     avrcp_emit_connection_closed(connection_controller->avrcp_cid);
851                     avrcp_finalize_connection(connection_controller);
852                     avrcp_finalize_connection(connection_target);
853                     break;
854 
855                 case L2CAP_EVENT_CAN_SEND_NOW:
856                     local_cid = l2cap_event_can_send_now_get_local_cid(packet);
857                     can_send = true;
858 
859                     connection_target = avrcp_get_connection_for_l2cap_signaling_cid_for_role(AVRCP_TARGET, local_cid);
860                     if ((connection_target != NULL) && connection_target->wait_to_send){
861                         connection_target->wait_to_send = false;
862                         (*avrcp_target_packet_handler)(HCI_EVENT_PACKET, channel, packet, size);
863                         can_send = false;
864                     }
865 
866                     connection_controller = avrcp_get_connection_for_l2cap_signaling_cid_for_role(AVRCP_CONTROLLER, local_cid);
867                     if ((connection_controller != NULL) && connection_controller->wait_to_send){
868                         if (can_send){
869                             connection_controller->wait_to_send = false;
870                             (*avrcp_controller_packet_handler)(HCI_EVENT_PACKET, channel, packet, size);
871                         } else {
872                             l2cap_request_can_send_now_event(local_cid);
873                         }
874                     }
875                     break;
876 
877                 default:
878                     break;
879             }
880             break;
881 
882         case L2CAP_DATA_PACKET:
883             switch (avrcp_get_frame_type(packet[0])){
884                 case AVRCP_RESPONSE_FRAME:
885                     (*avrcp_controller_packet_handler)(packet_type, channel, packet, size);
886                     break;
887                 case AVRCP_COMMAND_FRAME:
888                 default:    // make compiler happy
889                     (*avrcp_target_packet_handler)(packet_type, channel, packet, size);
890                     break;
891             }
892             break;
893 
894         default:
895             break;
896     }
897 }
898 
899 uint8_t avrcp_disconnect(uint16_t avrcp_cid){
900     avrcp_connection_t * connection_controller = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
901     if (!connection_controller){
902         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
903     }
904     avrcp_connection_t * connection_target = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_TARGET, avrcp_cid);
905     if (!connection_target){
906         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
907     }
908     if (connection_controller->browsing_connection){
909         l2cap_disconnect(connection_controller->browsing_connection->l2cap_browsing_cid, 0);
910     }
911     l2cap_disconnect(connection_controller->l2cap_signaling_cid, 0);
912     return ERROR_CODE_SUCCESS;
913 }
914 
915 static void avrcp_handle_start_sdp_client_query(void * context){
916     UNUSED(context);
917 
918     btstack_linked_list_iterator_t it;
919     btstack_linked_list_iterator_init(&it, &connections);
920     while (btstack_linked_list_iterator_has_next(&it)){
921         avrcp_connection_t * connection = (avrcp_connection_t *)btstack_linked_list_iterator_next(&it);
922 
923         if (connection->state != AVCTP_CONNECTION_W2_SEND_SDP_QUERY) continue;
924         connection->state = AVCTP_CONNECTION_W4_SDP_QUERY_COMPLETE;
925 
926         // prevent triggering SDP query twice (for each role once)
927         avrcp_connection_t * connection_with_opposite_role;
928         switch (connection->role){
929             case AVRCP_CONTROLLER:
930                 connection_with_opposite_role = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_TARGET, connection->avrcp_cid);
931                 break;
932             case AVRCP_TARGET:
933                 connection_with_opposite_role = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, connection->avrcp_cid);
934                 break;
935             default:
936                 btstack_assert(false);
937                 return;
938         }
939         connection_with_opposite_role->state = AVCTP_CONNECTION_W4_SDP_QUERY_COMPLETE;
940 
941         sdp_query_context.avrcp_l2cap_psm = 0;
942         sdp_query_context.avrcp_version  = 0;
943         sdp_query_context.avrcp_cid = connection->avrcp_cid;
944         sdp_client_query_uuid16(&avrcp_handle_sdp_client_query_result, (uint8_t *) connection->remote_addr, BLUETOOTH_PROTOCOL_AVCTP);
945         return;
946     }
947 }
948 
949 uint8_t avrcp_connect(bd_addr_t remote_addr, uint16_t * avrcp_cid){
950     btstack_assert(avrcp_controller_packet_handler != NULL);
951     btstack_assert(avrcp_target_packet_handler != NULL);
952 
953     avrcp_connection_t * connection_controller = avrcp_get_connection_for_bd_addr_for_role(AVRCP_CONTROLLER, remote_addr);
954     if (connection_controller){
955         return ERROR_CODE_COMMAND_DISALLOWED;
956     }
957     avrcp_connection_t * connection_target = avrcp_get_connection_for_bd_addr_for_role(AVRCP_TARGET, remote_addr);
958     if (connection_target){
959         return ERROR_CODE_COMMAND_DISALLOWED;
960     }
961 
962     uint16_t cid = avrcp_get_next_cid(AVRCP_CONTROLLER);
963 
964     connection_controller = avrcp_create_connection(AVRCP_CONTROLLER, remote_addr);
965     if (!connection_controller) return BTSTACK_MEMORY_ALLOC_FAILED;
966 
967     connection_target = avrcp_create_connection(AVRCP_TARGET, remote_addr);
968     if (!connection_target){
969         avrcp_finalize_connection(connection_controller);
970         return BTSTACK_MEMORY_ALLOC_FAILED;
971     }
972 
973     if (avrcp_cid != NULL){
974         *avrcp_cid = cid;
975     }
976 
977     connection_controller->state = AVCTP_CONNECTION_W2_SEND_SDP_QUERY;
978     connection_controller->avrcp_cid = cid;
979 
980     connection_target->state     = AVCTP_CONNECTION_W2_SEND_SDP_QUERY;
981     connection_target->avrcp_cid = cid;
982 
983     avrcp_handle_sdp_client_query_request.callback = &avrcp_handle_start_sdp_client_query;
984     // ignore ERROR_CODE_COMMAND_DISALLOWED because in that case, we already have requested an SDP callback
985     (void) sdp_client_register_query_callback(&avrcp_handle_sdp_client_query_request);
986     return ERROR_CODE_SUCCESS;
987 }
988 
989 void avrcp_init(void){
990     connections = NULL;
991     if (l2cap_service_registered) return;
992 
993     int status = l2cap_register_service(&avrcp_packet_handler, BLUETOOTH_PSM_AVCTP, 0xffff, gap_get_security_level());
994     if (status != ERROR_CODE_SUCCESS) return;
995     l2cap_service_registered = true;
996 }
997 
998 void avrcp_deinit(void){
999     avrcp_cid_counter = 0;
1000     l2cap_service_registered = false;
1001 
1002     (void) memset(&sdp_query_context, 0, sizeof(avrcp_sdp_query_context_t));
1003     (void) memset(attribute_value,0, sizeof(attribute_value));
1004 
1005     avrcp_callback = NULL;
1006     connections = NULL;
1007     avrcp_controller_packet_handler = NULL;
1008     avrcp_target_packet_handler = NULL;
1009 }
1010 
1011 void avrcp_register_controller_packet_handler(btstack_packet_handler_t callback){
1012     avrcp_controller_packet_handler = callback;
1013 }
1014 
1015 void avrcp_register_target_packet_handler(btstack_packet_handler_t callback){
1016     avrcp_target_packet_handler = callback;
1017 }
1018 
1019 void avrcp_register_packet_handler(btstack_packet_handler_t callback){
1020     btstack_assert(callback != NULL);
1021     avrcp_callback = callback;
1022 }
1023 
1024 #ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
1025 #define FUZZ_CID 0x44
1026 #define FUZZ_CON_HANDLE 0x0001
1027 static bd_addr_t remote_addr = { 0x33, 0x33, 0x33, 0x33, 0x33, 0x33 };
1028 void avrcp_init_fuzz(void){
1029     // setup avrcp connections for cid
1030     avrcp_connection_t * connection_controller = avrcp_create_connection(AVRCP_CONTROLLER, remote_addr);
1031     avrcp_connection_t * connection_target     = avrcp_create_connection(AVRCP_TARGET, remote_addr);
1032     avrcp_handle_open_connection(connection_controller, FUZZ_CON_HANDLE, FUZZ_CID, 999);
1033     avrcp_handle_open_connection(connection_target, FUZZ_CON_HANDLE, FUZZ_CID, 999);
1034 }
1035 void avrcp_packet_handler_fuzz(uint8_t *packet, uint16_t size){
1036     avrcp_packet_handler(L2CAP_DATA_PACKET, FUZZ_CID, packet, size);
1037 }
1038 #endif