xref: /btstack/src/classic/avrcp.c (revision b28dc8004dd8d4fb9020a6dcd2bc81f05d36a008)
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 BLUEKITCHEN
24  * GMBH OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
27  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
30  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * Please inquire about commercial licensing options at
34  * [email protected]
35  *
36  */
37 
38 #define BTSTACK_FILE__ "avrcp.c"
39 
40 #include <stdint.h>
41 #include <string.h>
42 // snprintf
43 #include <stdio.h>
44 
45 #include "bluetooth_psm.h"
46 #include "bluetooth_sdp.h"
47 #include "btstack_debug.h"
48 #include "btstack_event.h"
49 #include "btstack_memory.h"
50 #include "classic/sdp_client.h"
51 #include "classic/sdp_util.h"
52 #include "classic/avrcp.h"
53 
54 
55 typedef struct {
56     uint8_t  parse_sdp_record;
57     uint32_t record_id;
58     uint16_t avrcp_cid;
59     uint16_t avrcp_l2cap_psm;
60     uint16_t avrcp_version;
61 
62     uint16_t browsing_l2cap_psm;
63     uint16_t browsing_version;
64 } avrcp_sdp_query_context_t;
65 
66 static void avrcp_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
67 
68 static const char * avrcp_default_controller_service_name = "BTstack AVRCP Controller Service";
69 static const char * avrcp_default_controller_service_provider_name = "BTstack AVRCP Controller Service Provider";
70 static const char * avrcp_defaul_target_service_name = "BTstack AVRCP Target Service";
71 static const char * avrcp_default_target_service_provider_name = "BTstack AVRCP Target Service Provider";
72 
73 static const char * avrcp_subunit_type_name[] = {
74         "MONITOR", "AUDIO", "PRINTER", "DISC", "TAPE_RECORDER_PLAYER", "TUNER",
75         "CA", "CAMERA", "RESERVED", "PANEL", "BULLETIN_BOARD", "CAMERA_STORAGE",
76         "VENDOR_UNIQUE", "RESERVED_FOR_ALL_SUBUNIT_TYPES",
77         "EXTENDED_TO_NEXT_BYTE", "UNIT", "ERROR"
78 };
79 
80 // default subunit info: single PANEL subunit
81 static const uint8_t avrcp_default_subunit_info[] = { AVRCP_SUBUNIT_TYPE_PANEL << 3};
82 
83 // globals
84 static bool avrcp_l2cap_service_registered = false;
85 
86 // connections
87 static uint16_t                 avrcp_cid_counter;
88 static btstack_linked_list_t    avrcp_connections;
89 
90 // higher layer callbacks
91 static btstack_packet_handler_t avrcp_callback;
92 static btstack_packet_handler_t avrcp_controller_packet_handler;
93 static btstack_packet_handler_t avrcp_target_packet_handler;
94 
95 // sdp query
96 static btstack_context_callback_registration_t avrcp_sdp_query_registration;
97 static avrcp_sdp_query_context_t               avrcp_sdp_query_context;
98 static uint8_t                                 avrcp_sdp_query_attribute_value[45];
99 static const unsigned int                      avrcp_sdp_query_attribute_value_buffer_size = sizeof(avrcp_sdp_query_attribute_value);
100 
101 
102 const char * avrcp_subunit2str(uint16_t index){
103     if (index <= 11) return avrcp_subunit_type_name[index];
104     if ((index >= 0x1C) && (index <= 0x1F)) return avrcp_subunit_type_name[index - 0x10];
105     return avrcp_subunit_type_name[16];
106 }
107 
108 static const char * avrcp_event_name[] = {
109     "ERROR", "PLAYBACK_STATUS_CHANGED",
110     "TRACK_CHANGED", "TRACK_REACHED_END", "TRACK_REACHED_START",
111     "PLAYBACK_POS_CHANGED", "BATT_STATUS_CHANGED", "SYSTEM_STATUS_CHANGED",
112     "PLAYER_APPLICATION_SETTING_CHANGED", "NOW_PLAYING_CONTENT_CHANGED",
113     "AVAILABLE_PLAYERS_CHANGED", "ADDRESSED_PLAYER_CHANGED", "UIDS_CHANGED", "VOLUME_CHANGED"
114 };
115 const char * avrcp_event2str(uint16_t index){
116     if (index <= 0x0d) return avrcp_event_name[index];
117     return avrcp_event_name[0];
118 }
119 
120 static const char * avrcp_operation_name[] = {
121     "SKIP", NULL, NULL, NULL, NULL,
122     "VOLUME_UP", "VOLUME_DOWN", "MUTE", "PLAY", "STOP", "PAUSE", NULL,
123     "REWIND", "FAST_FORWARD", NULL, "FORWARD", "BACKWARD" // 0x4C
124 };
125 
126 const char * avrcp_operation2str(uint8_t operation_id){
127     char * name = NULL;
128     if ((operation_id >= AVRCP_OPERATION_ID_SKIP) && (operation_id <= AVRCP_OPERATION_ID_BACKWARD)){
129         name = (char *)avrcp_operation_name[operation_id - AVRCP_OPERATION_ID_SKIP];
130     }
131     if (name == NULL){
132         static char buffer[13];
133         snprintf(buffer, sizeof(buffer), "Unknown 0x%02x", operation_id);
134         buffer[sizeof(buffer)-1] = 0;
135         return buffer;
136     } else {
137         return name;
138     }
139 }
140 
141 static const char * avrcp_media_attribute_id_name[] = {
142     "NONE", "TITLE", "ARTIST", "ALBUM", "TRACK", "TOTAL TRACKS", "GENRE", "SONG LENGTH"
143 };
144 const char * avrcp_attribute2str(uint8_t index){
145     if ((index >= 1) && (index <= 7)) return avrcp_media_attribute_id_name[index];
146     return avrcp_media_attribute_id_name[0];
147 }
148 
149 static const char * avrcp_play_status_name[] = {
150     "STOPPED", "PLAYING", "PAUSED", "FORWARD SEEK", "REVERSE SEEK",
151     "ERROR" // 0xFF
152 };
153 const char * avrcp_play_status2str(uint8_t index){
154     if ((index >= 1) && (index <= 4)) return avrcp_play_status_name[index];
155     return avrcp_play_status_name[5];
156 }
157 
158 static const char * avrcp_ctype_name[] = {
159     "CONTROL",
160     "STATUS",
161     "SPECIFIC_INQUIRY",
162     "NOTIFY",
163     "GENERAL_INQUIRY",
164     "RESERVED5",
165     "RESERVED6",
166     "RESERVED7",
167     "NOT IMPLEMENTED IN REMOTE",
168     "ACCEPTED BY REMOTE",
169     "REJECTED BY REMOTE",
170     "IN_TRANSITION",
171     "IMPLEMENTED_STABLE",
172     "CHANGED_STABLE",
173     "RESERVED",
174     "INTERIM"
175 };
176 const char * avrcp_ctype2str(uint8_t index){
177     if (index < sizeof(avrcp_ctype_name)){
178         return avrcp_ctype_name[index];
179     }
180     return "NONE";
181 }
182 
183 static const char * avrcp_shuffle_mode_name[] = {
184     "SHUFFLE OFF",
185     "SHUFFLE ALL TRACKS",
186     "SHUFFLE GROUP"
187 };
188 
189 const char * avrcp_shuffle2str(uint8_t index){
190     if ((index >= 1) && (index <= 3)) return avrcp_shuffle_mode_name[index-1];
191     return "NONE";
192 }
193 
194 static const char * avrcp_repeat_mode_name[] = {
195     "REPEAT OFF",
196     "REPEAT SINGLE TRACK",
197     "REPEAT ALL TRACKS",
198     "REPEAT GROUP"
199 };
200 
201 const char * avrcp_repeat2str(uint8_t index){
202     if ((index >= 1) && (index <= 4)) return avrcp_repeat_mode_name[index-1];
203     return "NONE";
204 }
205 
206 btstack_linked_list_t avrcp_get_connections(void){
207     return avrcp_connections;
208 }
209 
210 uint8_t avrcp_cmd_opcode(uint8_t *packet, uint16_t size){
211     uint8_t cmd_opcode_index = 5;
212     if (cmd_opcode_index > size) return AVRCP_CMD_OPCODE_UNDEFINED;
213     return packet[cmd_opcode_index];
214 }
215 
216 void avrcp_create_sdp_record(uint8_t controller, uint8_t * service, uint32_t service_record_handle, uint8_t browsing, uint16_t supported_features,
217     const char * service_name, const char * service_provider_name){
218     uint8_t* attribute;
219     de_create_sequence(service);
220 
221     // 0x0000 "Service Record Handle"
222     de_add_number(service, DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_SERVICE_RECORD_HANDLE);
223     de_add_number(service, DE_UINT, DE_SIZE_32, service_record_handle);
224 
225     // 0x0001 "Service Class ID List"
226     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_SERVICE_CLASS_ID_LIST);
227     attribute = de_push_sequence(service);
228     {
229         if (controller){
230             de_add_number(attribute, DE_UUID, DE_SIZE_16, BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL);
231             de_add_number(attribute, DE_UUID, DE_SIZE_16, BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL_CONTROLLER);
232         } else {
233             de_add_number(attribute, DE_UUID, DE_SIZE_16, BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL_TARGET);
234         }
235     }
236     de_pop_sequence(service, attribute);
237 
238     // 0x0004 "Protocol Descriptor List"
239     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_PROTOCOL_DESCRIPTOR_LIST);
240     attribute = de_push_sequence(service);
241     {
242         uint8_t* l2cpProtocol = de_push_sequence(attribute);
243         {
244             de_add_number(l2cpProtocol,  DE_UUID, DE_SIZE_16, BLUETOOTH_PROTOCOL_L2CAP);
245             de_add_number(l2cpProtocol,  DE_UINT, DE_SIZE_16, BLUETOOTH_PSM_AVCTP);
246         }
247         de_pop_sequence(attribute, l2cpProtocol);
248 
249         uint8_t* avctpProtocol = de_push_sequence(attribute);
250         {
251             de_add_number(avctpProtocol,  DE_UUID, DE_SIZE_16, BLUETOOTH_PROTOCOL_AVCTP);  // avctpProtocol_service
252             de_add_number(avctpProtocol,  DE_UINT, DE_SIZE_16,  0x0104);    // version
253         }
254         de_pop_sequence(attribute, avctpProtocol);
255     }
256     de_pop_sequence(service, attribute);
257 
258     // 0x0005 "Public Browse Group"
259     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_BROWSE_GROUP_LIST); // public browse group
260     attribute = de_push_sequence(service);
261     {
262         de_add_number(attribute,  DE_UUID, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_PUBLIC_BROWSE_ROOT);
263     }
264     de_pop_sequence(service, attribute);
265 
266     // 0x0009 "Bluetooth Profile Descriptor List"
267     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_BLUETOOTH_PROFILE_DESCRIPTOR_LIST);
268     attribute = de_push_sequence(service);
269     {
270         uint8_t *avrcProfile = de_push_sequence(attribute);
271         {
272             de_add_number(avrcProfile,  DE_UUID, DE_SIZE_16, BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL);
273             de_add_number(avrcProfile,  DE_UINT, DE_SIZE_16, 0x0106);
274         }
275         de_pop_sequence(attribute, avrcProfile);
276     }
277     de_pop_sequence(service, attribute);
278 
279     // 0x000d "Additional Bluetooth Profile Descriptor List"
280     if (browsing){
281         de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_ADDITIONAL_PROTOCOL_DESCRIPTOR_LISTS);
282         attribute = de_push_sequence(service);
283         {
284             uint8_t * des = de_push_sequence(attribute);
285             {
286                 uint8_t* browsing_l2cpProtocol = de_push_sequence(des);
287                 {
288                     de_add_number(browsing_l2cpProtocol,  DE_UUID, DE_SIZE_16, BLUETOOTH_PROTOCOL_L2CAP);
289                     de_add_number(browsing_l2cpProtocol,  DE_UINT, DE_SIZE_16, BLUETOOTH_PSM_AVCTP_BROWSING);
290                 }
291                 de_pop_sequence(des, browsing_l2cpProtocol);
292 
293                 uint8_t* browsing_avctpProtocol = de_push_sequence(des);
294                 {
295                     de_add_number(browsing_avctpProtocol,  DE_UUID, DE_SIZE_16, BLUETOOTH_PROTOCOL_AVCTP);  // browsing_avctpProtocol_service
296                     de_add_number(browsing_avctpProtocol,  DE_UINT, DE_SIZE_16, 0x0104);                   // version
297                 }
298                 de_pop_sequence(des, browsing_avctpProtocol);
299             }
300             de_pop_sequence(attribute, des);
301         }
302         de_pop_sequence(service, attribute);
303     }
304 
305 
306     // 0x0100 "Service Name"
307     de_add_number(service,  DE_UINT, DE_SIZE_16, 0x0100);
308     if (service_name){
309         de_add_data(service,  DE_STRING, strlen(service_name), (uint8_t *) service_name);
310     } else {
311         if (controller){
312             de_add_data(service, DE_STRING, strlen(avrcp_default_controller_service_name), (uint8_t *) avrcp_default_controller_service_name);
313         } else {
314             de_add_data(service, DE_STRING, strlen(avrcp_defaul_target_service_name), (uint8_t *) avrcp_defaul_target_service_name);
315         }
316     }
317 
318     // 0x0100 "Provider Name"
319     de_add_number(service,  DE_UINT, DE_SIZE_16, 0x0102);
320     if (service_provider_name){
321         de_add_data(service,  DE_STRING, strlen(service_provider_name), (uint8_t *) service_provider_name);
322     } else {
323         if (controller){
324             de_add_data(service, DE_STRING, strlen(avrcp_default_controller_service_provider_name), (uint8_t *) avrcp_default_controller_service_provider_name);
325         } else {
326             de_add_data(service, DE_STRING, strlen(avrcp_default_target_service_provider_name), (uint8_t *) avrcp_default_target_service_provider_name);
327         }
328     }
329 
330     // 0x0311 "Supported Features"
331     de_add_number(service, DE_UINT, DE_SIZE_16, 0x0311);
332     de_add_number(service, DE_UINT, DE_SIZE_16, supported_features);
333 }
334 
335 avrcp_connection_t * avrcp_get_connection_for_bd_addr_for_role(avrcp_role_t role, bd_addr_t addr){
336     btstack_linked_list_iterator_t it;
337     btstack_linked_list_iterator_init(&it, (btstack_linked_list_t *) &avrcp_connections);
338     while (btstack_linked_list_iterator_has_next(&it)){
339         avrcp_connection_t * connection = (avrcp_connection_t *)btstack_linked_list_iterator_next(&it);
340         if (connection->role != role) continue;
341         if (memcmp(addr, connection->remote_addr, 6) != 0) continue;
342         return connection;
343     }
344     return NULL;
345 }
346 
347 avrcp_connection_t * avrcp_get_connection_for_l2cap_signaling_cid_for_role(avrcp_role_t role, uint16_t l2cap_cid){
348     btstack_linked_list_iterator_t it;
349     btstack_linked_list_iterator_init(&it, (btstack_linked_list_t *) &avrcp_connections);
350     while (btstack_linked_list_iterator_has_next(&it)){
351         avrcp_connection_t * connection = (avrcp_connection_t *)btstack_linked_list_iterator_next(&it);
352         if (connection->role != role) continue;
353         if (connection->l2cap_signaling_cid != l2cap_cid) continue;
354         return connection;
355     }
356     return NULL;
357 }
358 
359 avrcp_connection_t * avrcp_get_connection_for_avrcp_cid_for_role(avrcp_role_t role, uint16_t avrcp_cid){
360     btstack_linked_list_iterator_t it;
361     btstack_linked_list_iterator_init(&it, (btstack_linked_list_t *) &avrcp_connections);
362     while (btstack_linked_list_iterator_has_next(&it)){
363         avrcp_connection_t * connection = (avrcp_connection_t *)btstack_linked_list_iterator_next(&it);
364         if (connection->role != role) continue;
365         if (connection->avrcp_cid != avrcp_cid) continue;
366         return connection;
367     }
368     return NULL;
369 }
370 
371 avrcp_connection_t * avrcp_get_connection_for_browsing_cid_for_role(avrcp_role_t role, uint16_t browsing_cid){
372     btstack_linked_list_iterator_t it;
373     btstack_linked_list_iterator_init(&it, (btstack_linked_list_t *) &avrcp_connections);
374     while (btstack_linked_list_iterator_has_next(&it)){
375         avrcp_connection_t * connection = (avrcp_connection_t *)btstack_linked_list_iterator_next(&it);
376         if (connection->role != role) continue;
377         if (connection->avrcp_browsing_cid != browsing_cid) continue;
378         return connection;
379     }
380     return NULL;
381 }
382 
383 avrcp_connection_t * avrcp_get_connection_for_browsing_l2cap_cid_for_role(avrcp_role_t role, uint16_t browsing_l2cap_cid){
384     btstack_linked_list_iterator_t it;
385     btstack_linked_list_iterator_init(&it, (btstack_linked_list_t *) &avrcp_connections);
386     while (btstack_linked_list_iterator_has_next(&it)){
387         avrcp_connection_t * connection = (avrcp_connection_t *)btstack_linked_list_iterator_next(&it);
388         if (connection->role != role) continue;
389         if (connection->browsing_connection &&  (connection->browsing_connection->l2cap_browsing_cid != browsing_l2cap_cid)) continue;
390         return connection;
391     }
392     return NULL;
393 }
394 
395 avrcp_browsing_connection_t * avrcp_get_browsing_connection_for_l2cap_cid_for_role(avrcp_role_t role, uint16_t l2cap_cid){
396     btstack_linked_list_iterator_t it;
397     btstack_linked_list_iterator_init(&it, (btstack_linked_list_t *) &avrcp_connections);
398     while (btstack_linked_list_iterator_has_next(&it)){
399         avrcp_connection_t * connection = (avrcp_connection_t *)btstack_linked_list_iterator_next(&it);
400         if (connection->role != role) continue;
401         if (connection->browsing_connection && (connection->browsing_connection->l2cap_browsing_cid != l2cap_cid)) continue;
402         return connection->browsing_connection;
403     }
404     return NULL;
405 }
406 
407 void avrcp_request_can_send_now(avrcp_connection_t * connection, uint16_t l2cap_cid){
408     connection->wait_to_send = true;
409     l2cap_request_can_send_now_event(l2cap_cid);
410 }
411 
412 uint16_t avrcp_get_next_cid(avrcp_role_t role){
413     do {
414         if (avrcp_cid_counter == 0xffff) {
415             avrcp_cid_counter = 1;
416         } else {
417             avrcp_cid_counter++;
418         }
419     } while (avrcp_get_connection_for_avrcp_cid_for_role(role, avrcp_cid_counter) !=  NULL) ;
420     return avrcp_cid_counter;
421 }
422 
423 static avrcp_connection_t * avrcp_create_connection(avrcp_role_t role, bd_addr_t remote_addr){
424     avrcp_connection_t * connection = btstack_memory_avrcp_connection_get();
425     if (!connection){
426         log_error("Not enough memory to create connection for role %d", role);
427         return NULL;
428     }
429 
430     connection->state = AVCTP_CONNECTION_IDLE;
431     connection->role = role;
432 
433     connection->transaction_id = 0xFF;
434     connection->transaction_id_counter = 0;
435 
436     connection->max_num_fragments = 0xFF;
437 
438     // setup default unit / subunit info
439     connection->company_id = 0xffffff;
440     connection->unit_type = AVRCP_SUBUNIT_TYPE_PANEL;
441     connection->subunit_info_data_size = sizeof(avrcp_default_subunit_info);
442     connection->subunit_info_data = avrcp_default_subunit_info;
443 
444     log_info("avrcp_create_connection, role %d", role);
445     (void)memcpy(connection->remote_addr, remote_addr, 6);
446     btstack_linked_list_add(&avrcp_connections, (btstack_linked_item_t *) connection);
447     return connection;
448 }
449 
450 static void avrcp_finalize_connection(avrcp_connection_t * connection){
451     btstack_run_loop_remove_timer(&connection->retry_timer);
452     btstack_linked_list_remove(&avrcp_connections, (btstack_linked_item_t*) connection);
453     btstack_memory_avrcp_connection_free(connection);
454 }
455 
456 static void avrcp_emit_connection_established(uint16_t avrcp_cid, bd_addr_t addr, hci_con_handle_t con_handle, uint8_t status){
457     btstack_assert(avrcp_callback != NULL);
458 
459     uint8_t event[14];
460     int pos = 0;
461     event[pos++] = HCI_EVENT_AVRCP_META;
462     event[pos++] = sizeof(event) - 2;
463     event[pos++] = AVRCP_SUBEVENT_CONNECTION_ESTABLISHED;
464     event[pos++] = status;
465     little_endian_store_16(event, pos, avrcp_cid);
466     pos += 2;
467     reverse_bd_addr(addr,&event[pos]);
468     pos += 6;
469     little_endian_store_16(event, pos, con_handle);
470     pos += 2;
471     (*avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
472 }
473 
474 static void avrcp_emit_connection_closed(uint16_t avrcp_cid){
475     btstack_assert(avrcp_callback != NULL);
476 
477     uint8_t event[5];
478     int pos = 0;
479     event[pos++] = HCI_EVENT_AVRCP_META;
480     event[pos++] = sizeof(event) - 2;
481     event[pos++] = AVRCP_SUBEVENT_CONNECTION_RELEASED;
482     little_endian_store_16(event, pos, avrcp_cid);
483     pos += 2;
484     (*avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
485 }
486 
487 uint16_t avrcp_sdp_query_browsing_l2cap_psm(void){
488     return avrcp_sdp_query_context.browsing_l2cap_psm;
489 }
490 
491 void avrcp_handle_sdp_client_query_attribute_value(uint8_t *packet){
492     des_iterator_t des_list_it;
493     des_iterator_t prot_it;
494 
495     // Handle new SDP record
496     if (sdp_event_query_attribute_byte_get_record_id(packet) != avrcp_sdp_query_context.record_id) {
497         avrcp_sdp_query_context.record_id = sdp_event_query_attribute_byte_get_record_id(packet);
498         avrcp_sdp_query_context.parse_sdp_record = 0;
499         // log_info("SDP Record: Nr: %d", record_id);
500     }
501 
502     if (sdp_event_query_attribute_byte_get_attribute_length(packet) <= avrcp_sdp_query_attribute_value_buffer_size) {
503         avrcp_sdp_query_attribute_value[sdp_event_query_attribute_byte_get_data_offset(packet)] = sdp_event_query_attribute_byte_get_data(packet);
504 
505         if ((uint16_t)(sdp_event_query_attribute_byte_get_data_offset(packet)+1) == sdp_event_query_attribute_byte_get_attribute_length(packet)) {
506             switch(sdp_event_query_attribute_byte_get_attribute_id(packet)) {
507                 case BLUETOOTH_ATTRIBUTE_SERVICE_CLASS_ID_LIST:
508                     if (de_get_element_type(avrcp_sdp_query_attribute_value) != DE_DES) break;
509                     for (des_iterator_init(&des_list_it, avrcp_sdp_query_attribute_value); des_iterator_has_more(&des_list_it); des_iterator_next(&des_list_it)) {
510                         uint8_t * element = des_iterator_get_element(&des_list_it);
511                         if (de_get_element_type(element) != DE_UUID) continue;
512                         uint32_t uuid = de_get_uuid32(element);
513                         switch (uuid){
514                             case BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL_TARGET:
515                             case BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL:
516                             case BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL_CONTROLLER:
517                                 avrcp_sdp_query_context.parse_sdp_record = 1;
518                                 break;
519                             default:
520                                 break;
521                         }
522                     }
523                     break;
524 
525                 case BLUETOOTH_ATTRIBUTE_PROTOCOL_DESCRIPTOR_LIST: {
526                     if (!avrcp_sdp_query_context.parse_sdp_record) break;
527                     // log_info("SDP Attribute: 0x%04x", sdp_event_query_attribute_byte_get_attribute_id(packet));
528                     for (des_iterator_init(&des_list_it, avrcp_sdp_query_attribute_value); des_iterator_has_more(&des_list_it); des_iterator_next(&des_list_it)) {
529                         uint8_t       *des_element;
530                         uint8_t       *element;
531                         uint32_t       uuid;
532 
533                         if (des_iterator_get_type(&des_list_it) != DE_DES) continue;
534 
535                         des_element = des_iterator_get_element(&des_list_it);
536                         des_iterator_init(&prot_it, des_element);
537                         element = des_iterator_get_element(&prot_it);
538 
539                         if (de_get_element_type(element) != DE_UUID) continue;
540 
541                         uuid = de_get_uuid32(element);
542                         des_iterator_next(&prot_it);
543                         switch (uuid){
544                             case BLUETOOTH_PROTOCOL_L2CAP:
545                                 if (!des_iterator_has_more(&prot_it)) continue;
546                                 de_element_get_uint16(des_iterator_get_element(&prot_it), &avrcp_sdp_query_context.avrcp_l2cap_psm);
547                                 break;
548                             case BLUETOOTH_PROTOCOL_AVCTP:
549                                 if (!des_iterator_has_more(&prot_it)) continue;
550                                 de_element_get_uint16(des_iterator_get_element(&prot_it), &avrcp_sdp_query_context.avrcp_version);
551                                 break;
552                             default:
553                                 break;
554                         }
555                     }
556                 }
557                     break;
558                 case BLUETOOTH_ATTRIBUTE_ADDITIONAL_PROTOCOL_DESCRIPTOR_LISTS: {
559                     // log_info("SDP Attribute: 0x%04x", sdp_event_query_attribute_byte_get_attribute_id(packet));
560                     if (!avrcp_sdp_query_context.parse_sdp_record) break;
561                     if (de_get_element_type(avrcp_sdp_query_attribute_value) != DE_DES) break;
562 
563                     des_iterator_t des_list_0_it;
564                     uint8_t       *element_0;
565 
566                     des_iterator_init(&des_list_0_it, avrcp_sdp_query_attribute_value);
567                     element_0 = des_iterator_get_element(&des_list_0_it);
568 
569                     for (des_iterator_init(&des_list_it, element_0); des_iterator_has_more(&des_list_it); des_iterator_next(&des_list_it)) {
570                         uint8_t       *des_element;
571                         uint8_t       *element;
572                         uint32_t       uuid;
573 
574                         if (des_iterator_get_type(&des_list_it) != DE_DES) continue;
575 
576                         des_element = des_iterator_get_element(&des_list_it);
577                         des_iterator_init(&prot_it, des_element);
578                         element = des_iterator_get_element(&prot_it);
579 
580                         if (de_get_element_type(element) != DE_UUID) continue;
581 
582                         uuid = de_get_uuid32(element);
583                         des_iterator_next(&prot_it);
584                         switch (uuid){
585                             case BLUETOOTH_PROTOCOL_L2CAP:
586                                 if (!des_iterator_has_more(&prot_it)) continue;
587                                 de_element_get_uint16(des_iterator_get_element(&prot_it), &avrcp_sdp_query_context.browsing_l2cap_psm);
588                                 break;
589                             case BLUETOOTH_PROTOCOL_AVCTP:
590                                 if (!des_iterator_has_more(&prot_it)) continue;
591                                 de_element_get_uint16(des_iterator_get_element(&prot_it), &avrcp_sdp_query_context.browsing_version);
592                                 break;
593                             default:
594                                 break;
595                         }
596                     }
597                 }
598                     break;
599                 default:
600                     break;
601             }
602         }
603     } else {
604         log_error("SDP attribute value buffer size exceeded: available %d, required %d", avrcp_sdp_query_attribute_value_buffer_size, sdp_event_query_attribute_byte_get_attribute_length(packet));
605     }
606 }
607 
608 static void avrcp_handle_sdp_query_failed(avrcp_connection_t * connection, uint8_t status){
609     if (connection == NULL) return;
610     log_info("AVRCP: SDP query failed with status 0x%02x.", status);
611     avrcp_emit_connection_established(connection->avrcp_cid, connection->remote_addr, connection->con_handle, status);
612     avrcp_finalize_connection(connection);
613 }
614 
615 static void avrcp_handle_sdp_query_succeeded(avrcp_connection_t * connection){
616     if (connection == NULL) return;
617     connection->state = AVCTP_CONNECTION_W4_L2CAP_CONNECTED;
618     connection->avrcp_l2cap_psm = avrcp_sdp_query_context.avrcp_l2cap_psm;
619     connection->browsing_version = avrcp_sdp_query_context.browsing_version;
620     connection->browsing_l2cap_psm = avrcp_sdp_query_context.browsing_l2cap_psm;
621 }
622 
623 static void avrcp_handle_sdp_client_query_result(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
624     UNUSED(packet_type);
625     UNUSED(channel);
626     UNUSED(size);
627 
628     bool state_ok = true;
629     avrcp_connection_t * avrcp_target_connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_TARGET, avrcp_sdp_query_context.avrcp_cid);
630     if (!avrcp_target_connection || avrcp_target_connection->state != AVCTP_CONNECTION_W4_SDP_QUERY_COMPLETE) {
631         state_ok = false;
632     }
633     avrcp_connection_t * avrcp_controller_connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_sdp_query_context.avrcp_cid);
634     if (!avrcp_controller_connection || avrcp_controller_connection->state != AVCTP_CONNECTION_W4_SDP_QUERY_COMPLETE) {
635         state_ok = false;
636     }
637     if (!state_ok){
638         // something wrong, nevertheless, start next sdp query if this one is complete
639         if (hci_event_packet_get_type(packet) == SDP_EVENT_QUERY_COMPLETE){
640             (void) sdp_client_register_query_callback(&avrcp_sdp_query_registration);
641         }
642         return;
643     }
644 
645     uint8_t status;
646 
647     switch (hci_event_packet_get_type(packet)){
648         case SDP_EVENT_QUERY_ATTRIBUTE_VALUE:
649             avrcp_handle_sdp_client_query_attribute_value(packet);
650             return;
651 
652         case SDP_EVENT_QUERY_COMPLETE:
653             status = sdp_event_query_complete_get_status(packet);
654 
655             if (status != ERROR_CODE_SUCCESS){
656                 avrcp_handle_sdp_query_failed(avrcp_controller_connection, status);
657                 avrcp_handle_sdp_query_failed(avrcp_target_connection, status);
658                 break;
659             }
660 
661             if (!avrcp_sdp_query_context.avrcp_l2cap_psm){
662                 avrcp_handle_sdp_query_failed(avrcp_controller_connection, SDP_SERVICE_NOT_FOUND);
663                 avrcp_handle_sdp_query_failed(avrcp_target_connection, SDP_SERVICE_NOT_FOUND);
664                 break;
665             }
666 
667             avrcp_handle_sdp_query_succeeded(avrcp_controller_connection);
668             avrcp_handle_sdp_query_succeeded(avrcp_target_connection);
669 
670             l2cap_create_channel(&avrcp_packet_handler, avrcp_target_connection->remote_addr, avrcp_sdp_query_context.avrcp_l2cap_psm, l2cap_max_mtu(), NULL);
671             break;
672 
673         default:
674             return;
675     }
676 
677     // register the SDP Query request to check if there is another connection waiting for the query
678     // ignore ERROR_CODE_COMMAND_DISALLOWED because in that case, we already have requested an SDP callback
679     (void) sdp_client_register_query_callback(&avrcp_sdp_query_registration);
680 }
681 
682 
683 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){
684     if (connection == NULL){
685         connection = avrcp_create_connection(role, event_addr);
686     }
687     if (connection) {
688         connection->state = AVCTP_CONNECTION_W4_L2CAP_CONNECTED;
689         connection->l2cap_signaling_cid = local_cid;
690         connection->avrcp_cid = avrcp_cid;
691         connection->con_handle = con_handle;
692         btstack_run_loop_remove_timer(&connection->retry_timer);
693     }
694     return connection;
695 }
696 
697 static void avrcp_handle_open_connection(avrcp_connection_t * connection, hci_con_handle_t con_handle, uint16_t local_cid, uint16_t l2cap_mtu){
698     connection->l2cap_signaling_cid = local_cid;
699     connection->l2cap_mtu = l2cap_mtu;
700     connection->con_handle = con_handle;
701     connection->incoming_declined = false;
702     connection->song_length_ms = 0xFFFFFFFF;
703     connection->song_position_ms = 0xFFFFFFFF;
704     connection->playback_status = AVRCP_PLAYBACK_STATUS_STOPPED;
705     connection->state = AVCTP_CONNECTION_OPENED;
706 
707     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);
708 }
709 
710 static void avrcp_retry_timer_timeout_handler(btstack_timer_source_t * timer){
711     uint16_t avrcp_cid = (uint16_t)(uintptr_t) btstack_run_loop_get_timer_context(timer);
712     avrcp_connection_t * connection_controller = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
713     if (connection_controller == NULL) return;
714     avrcp_connection_t * connection_target = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_TARGET, avrcp_cid);
715     if (connection_target == NULL) return;
716 
717     if (connection_controller->state == AVCTP_CONNECTION_W2_L2CAP_RETRY){
718         connection_controller->state = AVCTP_CONNECTION_W4_L2CAP_CONNECTED;
719         connection_target->state = AVCTP_CONNECTION_W4_L2CAP_CONNECTED;
720         l2cap_create_channel(&avrcp_packet_handler, connection_controller->remote_addr, connection_controller->avrcp_l2cap_psm, l2cap_max_mtu(), NULL);
721     }
722 }
723 
724 static void avrcp_retry_timer_start(avrcp_connection_t * connection){
725     btstack_run_loop_set_timer_handler(&connection->retry_timer, avrcp_retry_timer_timeout_handler);
726     btstack_run_loop_set_timer_context(&connection->retry_timer, (void *)(uintptr_t)connection->avrcp_cid);
727 
728     // add some jitter/randomness to reconnect delay
729     uint32_t timeout = 100 + (btstack_run_loop_get_time_ms() & 0x7F);
730     btstack_run_loop_set_timer(&connection->retry_timer, timeout);
731 
732     btstack_run_loop_add_timer(&connection->retry_timer);
733 }
734 
735 static avrcp_frame_type_t avrcp_get_frame_type(uint8_t header){
736     return (avrcp_frame_type_t)((header & 0x02) >> 1);
737 }
738 
739 static void avrcp_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
740     UNUSED(channel);
741     UNUSED(size);
742     bd_addr_t event_addr;
743     uint16_t local_cid;
744     uint16_t l2cap_mtu;
745     uint8_t  status;
746     bool decline_connection;
747     bool outoing_active;
748     hci_con_handle_t con_handle;
749 
750     avrcp_connection_t * connection_controller;
751     avrcp_connection_t * connection_target;
752     bool can_send;
753 
754     switch (packet_type) {
755         case HCI_EVENT_PACKET:
756             switch (hci_event_packet_get_type(packet)) {
757 
758                 case L2CAP_EVENT_INCOMING_CONNECTION:
759                     btstack_assert(avrcp_controller_packet_handler != NULL);
760                     btstack_assert(avrcp_target_packet_handler != NULL);
761 
762                     l2cap_event_incoming_connection_get_address(packet, event_addr);
763                     local_cid = l2cap_event_incoming_connection_get_local_cid(packet);
764                     con_handle = l2cap_event_incoming_connection_get_handle(packet);
765 
766                     outoing_active = false;
767                     connection_target = avrcp_get_connection_for_bd_addr_for_role(AVRCP_TARGET, event_addr);
768                     if (connection_target != NULL){
769                         if (connection_target->state == AVCTP_CONNECTION_W4_L2CAP_CONNECTED){
770                             outoing_active = true;
771                             connection_target->incoming_declined = true;
772                         }
773                     }
774 
775                     connection_controller = avrcp_get_connection_for_bd_addr_for_role(AVRCP_CONTROLLER, event_addr);
776                     if (connection_controller != NULL){
777                         if (connection_controller->state == AVCTP_CONNECTION_W4_L2CAP_CONNECTED) {
778                             outoing_active = true;
779                             connection_controller->incoming_declined = true;
780                         }
781                     }
782 
783                     decline_connection = outoing_active;
784                     if (decline_connection == false){
785                         uint16_t avrcp_cid;
786                         if ((connection_controller == NULL) || (connection_target == NULL)){
787                             avrcp_cid = avrcp_get_next_cid(AVRCP_CONTROLLER);
788                         } else {
789                             avrcp_cid = connection_controller->avrcp_cid;
790                         }
791                         // create two connection objects (both)
792                         connection_target     = avrcp_handle_incoming_connection_for_role(AVRCP_TARGET, connection_target, event_addr, con_handle, local_cid, avrcp_cid);
793                         connection_controller = avrcp_handle_incoming_connection_for_role(AVRCP_CONTROLLER, connection_controller, event_addr, con_handle, local_cid, avrcp_cid);
794                         if ((connection_target == NULL) || (connection_controller == NULL)){
795                             decline_connection = true;
796                             if (connection_target) {
797                                 avrcp_finalize_connection(connection_target);
798                             }
799                             if (connection_controller) {
800                                 avrcp_finalize_connection(connection_controller);
801                             }
802                         }
803                     }
804                     if (decline_connection){
805                         l2cap_decline_connection(local_cid);
806                     } else {
807                         log_info("AVRCP: L2CAP_EVENT_INCOMING_CONNECTION local cid 0x%02x, state %d", local_cid, connection_controller->state);
808                         l2cap_accept_connection(local_cid);
809                     }
810                     break;
811 
812                 case L2CAP_EVENT_CHANNEL_OPENED:
813                     l2cap_event_channel_opened_get_address(packet, event_addr);
814                     status = l2cap_event_channel_opened_get_status(packet);
815                     local_cid = l2cap_event_channel_opened_get_local_cid(packet);
816                     l2cap_mtu = l2cap_event_channel_opened_get_remote_mtu(packet);
817                     con_handle = l2cap_event_channel_opened_get_handle(packet);
818 
819                     connection_controller = avrcp_get_connection_for_bd_addr_for_role(AVRCP_CONTROLLER, event_addr);
820                     connection_target = avrcp_get_connection_for_bd_addr_for_role(AVRCP_TARGET, event_addr);
821 
822                     // incoming: structs are already created in L2CAP_EVENT_INCOMING_CONNECTION
823                     // outgoing: structs are cteated in avrcp_connect()
824                     if ((connection_controller == NULL) || (connection_target == NULL)) {
825                         break;
826                     }
827 
828                     switch (status){
829                         case ERROR_CODE_SUCCESS:
830                             avrcp_handle_open_connection(connection_target, con_handle, local_cid, l2cap_mtu);
831                             avrcp_handle_open_connection(connection_controller, con_handle, local_cid, l2cap_mtu);
832                             avrcp_emit_connection_established(connection_controller->avrcp_cid, event_addr, con_handle, status);
833                             return;
834                         case L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_RESOURCES:
835                             if (connection_controller->incoming_declined == true){
836                                 log_info("Incoming connection was declined, and the outgoing failed");
837                                 connection_controller->state = AVCTP_CONNECTION_W2_L2CAP_RETRY;
838                                 connection_controller->incoming_declined = false;
839                                 connection_target->state = AVCTP_CONNECTION_W2_L2CAP_RETRY;
840                                 connection_target->incoming_declined = false;
841                                 avrcp_retry_timer_start(connection_controller);
842                                 return;
843                             }
844                             break;
845                         default:
846                             break;
847                     }
848                     log_info("L2CAP connection to connection %s failed. status code 0x%02x", bd_addr_to_str(event_addr), status);
849                     avrcp_emit_connection_established(connection_controller->avrcp_cid, event_addr, con_handle, status);
850                     avrcp_finalize_connection(connection_controller);
851                     avrcp_finalize_connection(connection_target);
852 
853                     break;
854 
855                 case L2CAP_EVENT_CHANNEL_CLOSED:
856                     local_cid = l2cap_event_channel_closed_get_local_cid(packet);
857 
858                     connection_controller = avrcp_get_connection_for_l2cap_signaling_cid_for_role(AVRCP_CONTROLLER, local_cid);
859                     connection_target = avrcp_get_connection_for_l2cap_signaling_cid_for_role(AVRCP_TARGET, local_cid);
860                     if ((connection_controller == NULL) || (connection_target == NULL)) {
861                         break;
862                     }
863                     avrcp_emit_connection_closed(connection_controller->avrcp_cid);
864                     avrcp_finalize_connection(connection_controller);
865                     avrcp_finalize_connection(connection_target);
866                     break;
867 
868                 case L2CAP_EVENT_CAN_SEND_NOW:
869                     local_cid = l2cap_event_can_send_now_get_local_cid(packet);
870                     can_send = true;
871 
872                     connection_target = avrcp_get_connection_for_l2cap_signaling_cid_for_role(AVRCP_TARGET, local_cid);
873                     if ((connection_target != NULL) && connection_target->wait_to_send){
874                         connection_target->wait_to_send = false;
875                         (*avrcp_target_packet_handler)(HCI_EVENT_PACKET, channel, packet, size);
876                         can_send = false;
877                     }
878 
879                     connection_controller = avrcp_get_connection_for_l2cap_signaling_cid_for_role(AVRCP_CONTROLLER, local_cid);
880                     if ((connection_controller != NULL) && connection_controller->wait_to_send){
881                         if (can_send){
882                             connection_controller->wait_to_send = false;
883                             (*avrcp_controller_packet_handler)(HCI_EVENT_PACKET, channel, packet, size);
884                         } else {
885                             l2cap_request_can_send_now_event(local_cid);
886                         }
887                     }
888                     break;
889 
890                 default:
891                     break;
892             }
893             break;
894 
895         case L2CAP_DATA_PACKET:
896             switch (avrcp_get_frame_type(packet[0])){
897                 case AVRCP_RESPONSE_FRAME:
898                     (*avrcp_controller_packet_handler)(packet_type, channel, packet, size);
899                     break;
900                 case AVRCP_COMMAND_FRAME:
901                 default:    // make compiler happy
902                     (*avrcp_target_packet_handler)(packet_type, channel, packet, size);
903                     break;
904             }
905             break;
906 
907         default:
908             break;
909     }
910 }
911 
912 uint8_t avrcp_disconnect(uint16_t avrcp_cid){
913     avrcp_connection_t * connection_controller = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
914     if (!connection_controller){
915         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
916     }
917     avrcp_connection_t * connection_target = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_TARGET, avrcp_cid);
918     if (!connection_target){
919         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
920     }
921     if (connection_controller->browsing_connection){
922         l2cap_disconnect(connection_controller->browsing_connection->l2cap_browsing_cid, 0);
923     }
924     l2cap_disconnect(connection_controller->l2cap_signaling_cid, 0);
925     return ERROR_CODE_SUCCESS;
926 }
927 
928 static void avrcp_handle_start_sdp_client_query(void * context){
929     UNUSED(context);
930 
931     btstack_linked_list_iterator_t it;
932     btstack_linked_list_iterator_init(&it, &avrcp_connections);
933     while (btstack_linked_list_iterator_has_next(&it)){
934         avrcp_connection_t * connection = (avrcp_connection_t *)btstack_linked_list_iterator_next(&it);
935 
936         if (connection->state != AVCTP_CONNECTION_W2_SEND_SDP_QUERY) continue;
937         connection->state = AVCTP_CONNECTION_W4_SDP_QUERY_COMPLETE;
938 
939         // prevent triggering SDP query twice (for each role once)
940         avrcp_connection_t * connection_with_opposite_role;
941         switch (connection->role){
942             case AVRCP_CONTROLLER:
943                 connection_with_opposite_role = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_TARGET, connection->avrcp_cid);
944                 break;
945             case AVRCP_TARGET:
946                 connection_with_opposite_role = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, connection->avrcp_cid);
947                 break;
948             default:
949                 btstack_assert(false);
950                 return;
951         }
952         connection_with_opposite_role->state = AVCTP_CONNECTION_W4_SDP_QUERY_COMPLETE;
953 
954         avrcp_sdp_query_context.avrcp_l2cap_psm = 0;
955         avrcp_sdp_query_context.avrcp_version  = 0;
956         avrcp_sdp_query_context.avrcp_cid = connection->avrcp_cid;
957         sdp_client_query_uuid16(&avrcp_handle_sdp_client_query_result, (uint8_t *) connection->remote_addr, BLUETOOTH_PROTOCOL_AVCTP);
958         return;
959     }
960 }
961 
962 uint8_t avrcp_connect(bd_addr_t remote_addr, uint16_t * avrcp_cid){
963     btstack_assert(avrcp_controller_packet_handler != NULL);
964     btstack_assert(avrcp_target_packet_handler != NULL);
965 
966     avrcp_connection_t * connection_controller = avrcp_get_connection_for_bd_addr_for_role(AVRCP_CONTROLLER, remote_addr);
967     if (connection_controller){
968         return ERROR_CODE_COMMAND_DISALLOWED;
969     }
970     avrcp_connection_t * connection_target = avrcp_get_connection_for_bd_addr_for_role(AVRCP_TARGET, remote_addr);
971     if (connection_target){
972         return ERROR_CODE_COMMAND_DISALLOWED;
973     }
974 
975     uint16_t cid = avrcp_get_next_cid(AVRCP_CONTROLLER);
976 
977     connection_controller = avrcp_create_connection(AVRCP_CONTROLLER, remote_addr);
978     if (!connection_controller) return BTSTACK_MEMORY_ALLOC_FAILED;
979 
980     connection_target = avrcp_create_connection(AVRCP_TARGET, remote_addr);
981     if (!connection_target){
982         avrcp_finalize_connection(connection_controller);
983         return BTSTACK_MEMORY_ALLOC_FAILED;
984     }
985 
986     if (avrcp_cid != NULL){
987         *avrcp_cid = cid;
988     }
989 
990     connection_controller->state = AVCTP_CONNECTION_W2_SEND_SDP_QUERY;
991     connection_controller->avrcp_cid = cid;
992 
993     connection_target->state     = AVCTP_CONNECTION_W2_SEND_SDP_QUERY;
994     connection_target->avrcp_cid = cid;
995 
996     avrcp_sdp_query_registration.callback = &avrcp_handle_start_sdp_client_query;
997     // ignore ERROR_CODE_COMMAND_DISALLOWED because in that case, we already have requested an SDP callback
998     (void) sdp_client_register_query_callback(&avrcp_sdp_query_registration);
999     return ERROR_CODE_SUCCESS;
1000 }
1001 
1002 void avrcp_init(void){
1003     avrcp_connections = NULL;
1004     if (avrcp_l2cap_service_registered) return;
1005 
1006     int status = l2cap_register_service(&avrcp_packet_handler, BLUETOOTH_PSM_AVCTP, 0xffff, gap_get_security_level());
1007     if (status != ERROR_CODE_SUCCESS) return;
1008     avrcp_l2cap_service_registered = true;
1009 }
1010 
1011 void avrcp_deinit(void){
1012     avrcp_l2cap_service_registered = false;
1013 
1014     avrcp_cid_counter = 0;
1015     avrcp_connections = NULL;
1016 
1017     avrcp_callback = NULL;
1018     avrcp_controller_packet_handler = NULL;
1019     avrcp_target_packet_handler = NULL;
1020 
1021     (void) memset(&avrcp_sdp_query_registration, 0, sizeof(avrcp_sdp_query_registration));
1022     (void) memset(&avrcp_sdp_query_context, 0, sizeof(avrcp_sdp_query_context_t));
1023     (void) memset(avrcp_sdp_query_attribute_value, 0, sizeof(avrcp_sdp_query_attribute_value));
1024 }
1025 
1026 void avrcp_register_controller_packet_handler(btstack_packet_handler_t callback){
1027     avrcp_controller_packet_handler = callback;
1028 }
1029 
1030 void avrcp_register_target_packet_handler(btstack_packet_handler_t callback){
1031     avrcp_target_packet_handler = callback;
1032 }
1033 
1034 void avrcp_register_packet_handler(btstack_packet_handler_t callback){
1035     btstack_assert(callback != NULL);
1036     avrcp_callback = callback;
1037 }
1038 
1039 #ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
1040 #define FUZZ_CID 0x44
1041 #define FUZZ_CON_HANDLE 0x0001
1042 static bd_addr_t remote_addr = { 0x33, 0x33, 0x33, 0x33, 0x33, 0x33 };
1043 void avrcp_init_fuzz(void){
1044     // setup avrcp connections for cid
1045     avrcp_connection_t * connection_controller = avrcp_create_connection(AVRCP_CONTROLLER, remote_addr);
1046     avrcp_connection_t * connection_target     = avrcp_create_connection(AVRCP_TARGET, remote_addr);
1047     avrcp_handle_open_connection(connection_controller, FUZZ_CON_HANDLE, FUZZ_CID, 999);
1048     avrcp_handle_open_connection(connection_target, FUZZ_CON_HANDLE, FUZZ_CID, 999);
1049 }
1050 void avrcp_packet_handler_fuzz(uint8_t *packet, uint16_t size){
1051     avrcp_packet_handler(L2CAP_DATA_PACKET, FUZZ_CID, packet, size);
1052 }
1053 #endif