xref: /btstack/src/classic/avrcp.c (revision 66b242bbd9ba4c4f1e5a61cd1a7e41aa511e6eb8)
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 static uint16_t avrcp_get_max_payload_size_for_avctp_packet_type(avrcp_connection_t * connection, avctp_packet_type_t avctp_packet_type){
336     uint16_t max_frame_size = btstack_min(l2cap_get_remote_mtu_for_local_cid(connection->l2cap_signaling_cid), AVRCP_MAX_AV_C_MESSAGE_FRAME_SIZE);
337 
338     switch (avctp_packet_type){
339         case AVCTP_SINGLE_PACKET:
340             return max_frame_size - 3;
341         case AVCTP_START_PACKET:
342             return max_frame_size - 4;
343         case AVCTP_CONTINUE_PACKET:
344         case AVCTP_END_PACKET:
345             return max_frame_size - 1;
346         default:
347             btstack_assert(false);
348             return 0;
349     }
350 }
351 
352 avctp_packet_type_t avrcp_get_avctp_packet_type(avrcp_connection_t * connection){
353     if (connection->data_offset == 0){
354         if (avrcp_get_max_payload_size_for_avctp_packet_type(connection, AVCTP_SINGLE_PACKET) >= connection->data_len){
355             return AVCTP_SINGLE_PACKET;
356         } else {
357             return AVCTP_START_PACKET;
358         }
359 
360     } else {
361         if ((connection->data_len - connection->data_offset) > avrcp_get_max_payload_size_for_avctp_packet_type(connection, AVCTP_CONTINUE_PACKET)){
362              return AVCTP_CONTINUE_PACKET;
363          } else {
364             return AVCTP_END_PACKET;
365          }
366     }
367 }
368 
369 avrcp_connection_t * avrcp_get_connection_for_bd_addr_for_role(avrcp_role_t role, bd_addr_t addr){
370     btstack_linked_list_iterator_t it;
371     btstack_linked_list_iterator_init(&it, (btstack_linked_list_t *) &avrcp_connections);
372     while (btstack_linked_list_iterator_has_next(&it)){
373         avrcp_connection_t * connection = (avrcp_connection_t *)btstack_linked_list_iterator_next(&it);
374         if (connection->role != role) continue;
375         if (memcmp(addr, connection->remote_addr, 6) != 0) continue;
376         return connection;
377     }
378     return NULL;
379 }
380 
381 avrcp_connection_t * avrcp_get_connection_for_l2cap_signaling_cid_for_role(avrcp_role_t role, uint16_t l2cap_cid){
382     btstack_linked_list_iterator_t it;
383     btstack_linked_list_iterator_init(&it, (btstack_linked_list_t *) &avrcp_connections);
384     while (btstack_linked_list_iterator_has_next(&it)){
385         avrcp_connection_t * connection = (avrcp_connection_t *)btstack_linked_list_iterator_next(&it);
386         if (connection->role != role) continue;
387         if (connection->l2cap_signaling_cid != l2cap_cid) continue;
388         return connection;
389     }
390     return NULL;
391 }
392 
393 avrcp_connection_t * avrcp_get_connection_for_avrcp_cid_for_role(avrcp_role_t role, uint16_t avrcp_cid){
394     btstack_linked_list_iterator_t it;
395     btstack_linked_list_iterator_init(&it, (btstack_linked_list_t *) &avrcp_connections);
396     while (btstack_linked_list_iterator_has_next(&it)){
397         avrcp_connection_t * connection = (avrcp_connection_t *)btstack_linked_list_iterator_next(&it);
398         if (connection->role != role) continue;
399         if (connection->avrcp_cid != avrcp_cid) continue;
400         return connection;
401     }
402     return NULL;
403 }
404 
405 avrcp_connection_t * avrcp_get_connection_for_browsing_cid_for_role(avrcp_role_t role, uint16_t browsing_cid){
406     btstack_linked_list_iterator_t it;
407     btstack_linked_list_iterator_init(&it, (btstack_linked_list_t *) &avrcp_connections);
408     while (btstack_linked_list_iterator_has_next(&it)){
409         avrcp_connection_t * connection = (avrcp_connection_t *)btstack_linked_list_iterator_next(&it);
410         if (connection->role != role) continue;
411         if (connection->avrcp_browsing_cid != browsing_cid) continue;
412         return connection;
413     }
414     return NULL;
415 }
416 
417 avrcp_connection_t * avrcp_get_connection_for_browsing_l2cap_cid_for_role(avrcp_role_t role, uint16_t browsing_l2cap_cid){
418     btstack_linked_list_iterator_t it;
419     btstack_linked_list_iterator_init(&it, (btstack_linked_list_t *) &avrcp_connections);
420     while (btstack_linked_list_iterator_has_next(&it)){
421         avrcp_connection_t * connection = (avrcp_connection_t *)btstack_linked_list_iterator_next(&it);
422         if (connection->role != role) continue;
423         if (connection->browsing_connection &&  (connection->browsing_connection->l2cap_browsing_cid != browsing_l2cap_cid)) continue;
424         return connection;
425     }
426     return NULL;
427 }
428 
429 avrcp_browsing_connection_t * avrcp_get_browsing_connection_for_l2cap_cid_for_role(avrcp_role_t role, uint16_t l2cap_cid){
430     btstack_linked_list_iterator_t it;
431     btstack_linked_list_iterator_init(&it, (btstack_linked_list_t *) &avrcp_connections);
432     while (btstack_linked_list_iterator_has_next(&it)){
433         avrcp_connection_t * connection = (avrcp_connection_t *)btstack_linked_list_iterator_next(&it);
434         if (connection->role != role) continue;
435         if (connection->browsing_connection && (connection->browsing_connection->l2cap_browsing_cid != l2cap_cid)) continue;
436         return connection->browsing_connection;
437     }
438     return NULL;
439 }
440 
441 void avrcp_request_can_send_now(avrcp_connection_t * connection, uint16_t l2cap_cid){
442     connection->wait_to_send = true;
443     l2cap_request_can_send_now_event(l2cap_cid);
444 }
445 
446 uint16_t avrcp_get_next_cid(avrcp_role_t role){
447     do {
448         if (avrcp_cid_counter == 0xffff) {
449             avrcp_cid_counter = 1;
450         } else {
451             avrcp_cid_counter++;
452         }
453     } while (avrcp_get_connection_for_avrcp_cid_for_role(role, avrcp_cid_counter) !=  NULL) ;
454     return avrcp_cid_counter;
455 }
456 
457 static avrcp_connection_t * avrcp_create_connection(avrcp_role_t role, bd_addr_t remote_addr){
458     avrcp_connection_t * connection = btstack_memory_avrcp_connection_get();
459     if (!connection){
460         log_error("Not enough memory to create connection for role %d", role);
461         return NULL;
462     }
463 
464     connection->state = AVCTP_CONNECTION_IDLE;
465     connection->role = role;
466 
467     connection->transaction_id = 0xFF;
468     connection->transaction_id_counter = 0;
469 
470     connection->max_num_fragments = 0xFF;
471 
472     // setup default unit / subunit info
473     connection->company_id = 0xffffff;
474     connection->unit_type = AVRCP_SUBUNIT_TYPE_PANEL;
475     connection->subunit_info_data_size = sizeof(avrcp_default_subunit_info);
476     connection->subunit_info_data = avrcp_default_subunit_info;
477 
478     log_info("avrcp_create_connection, role %d", role);
479     (void)memcpy(connection->remote_addr, remote_addr, 6);
480     btstack_linked_list_add(&avrcp_connections, (btstack_linked_item_t *) connection);
481     return connection;
482 }
483 
484 static void avrcp_finalize_connection(avrcp_connection_t * connection){
485     btstack_run_loop_remove_timer(&connection->retry_timer);
486     btstack_linked_list_remove(&avrcp_connections, (btstack_linked_item_t*) connection);
487     btstack_memory_avrcp_connection_free(connection);
488 }
489 
490 static void avrcp_emit_connection_established(uint16_t avrcp_cid, bd_addr_t addr, hci_con_handle_t con_handle, uint8_t status){
491     btstack_assert(avrcp_callback != NULL);
492 
493     uint8_t event[14];
494     int pos = 0;
495     event[pos++] = HCI_EVENT_AVRCP_META;
496     event[pos++] = sizeof(event) - 2;
497     event[pos++] = AVRCP_SUBEVENT_CONNECTION_ESTABLISHED;
498     event[pos++] = status;
499     little_endian_store_16(event, pos, avrcp_cid);
500     pos += 2;
501     reverse_bd_addr(addr,&event[pos]);
502     pos += 6;
503     little_endian_store_16(event, pos, con_handle);
504     pos += 2;
505     (*avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
506 }
507 
508 static void avrcp_emit_connection_closed(uint16_t avrcp_cid){
509     btstack_assert(avrcp_callback != NULL);
510 
511     uint8_t event[5];
512     int pos = 0;
513     event[pos++] = HCI_EVENT_AVRCP_META;
514     event[pos++] = sizeof(event) - 2;
515     event[pos++] = AVRCP_SUBEVENT_CONNECTION_RELEASED;
516     little_endian_store_16(event, pos, avrcp_cid);
517     pos += 2;
518     (*avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
519 }
520 
521 uint16_t avrcp_sdp_query_browsing_l2cap_psm(void){
522     return avrcp_sdp_query_context.browsing_l2cap_psm;
523 }
524 
525 void avrcp_handle_sdp_client_query_attribute_value(uint8_t *packet){
526     des_iterator_t des_list_it;
527     des_iterator_t prot_it;
528 
529     // Handle new SDP record
530     if (sdp_event_query_attribute_byte_get_record_id(packet) != avrcp_sdp_query_context.record_id) {
531         avrcp_sdp_query_context.record_id = sdp_event_query_attribute_byte_get_record_id(packet);
532         avrcp_sdp_query_context.parse_sdp_record = 0;
533         // log_info("SDP Record: Nr: %d", record_id);
534     }
535 
536     if (sdp_event_query_attribute_byte_get_attribute_length(packet) <= avrcp_sdp_query_attribute_value_buffer_size) {
537         avrcp_sdp_query_attribute_value[sdp_event_query_attribute_byte_get_data_offset(packet)] = sdp_event_query_attribute_byte_get_data(packet);
538 
539         if ((uint16_t)(sdp_event_query_attribute_byte_get_data_offset(packet)+1) == sdp_event_query_attribute_byte_get_attribute_length(packet)) {
540             switch(sdp_event_query_attribute_byte_get_attribute_id(packet)) {
541                 case BLUETOOTH_ATTRIBUTE_SERVICE_CLASS_ID_LIST:
542                     if (de_get_element_type(avrcp_sdp_query_attribute_value) != DE_DES) break;
543                     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)) {
544                         uint8_t * element = des_iterator_get_element(&des_list_it);
545                         if (de_get_element_type(element) != DE_UUID) continue;
546                         uint32_t uuid = de_get_uuid32(element);
547                         switch (uuid){
548                             case BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL_TARGET:
549                             case BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL:
550                             case BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL_CONTROLLER:
551                                 avrcp_sdp_query_context.parse_sdp_record = 1;
552                                 break;
553                             default:
554                                 break;
555                         }
556                     }
557                     break;
558 
559                 case BLUETOOTH_ATTRIBUTE_PROTOCOL_DESCRIPTOR_LIST: {
560                     if (!avrcp_sdp_query_context.parse_sdp_record) break;
561                     // log_info("SDP Attribute: 0x%04x", sdp_event_query_attribute_byte_get_attribute_id(packet));
562                     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)) {
563                         uint8_t       *des_element;
564                         uint8_t       *element;
565                         uint32_t       uuid;
566 
567                         if (des_iterator_get_type(&des_list_it) != DE_DES) continue;
568 
569                         des_element = des_iterator_get_element(&des_list_it);
570                         des_iterator_init(&prot_it, des_element);
571                         element = des_iterator_get_element(&prot_it);
572 
573                         if (de_get_element_type(element) != DE_UUID) continue;
574 
575                         uuid = de_get_uuid32(element);
576                         des_iterator_next(&prot_it);
577                         switch (uuid){
578                             case BLUETOOTH_PROTOCOL_L2CAP:
579                                 if (!des_iterator_has_more(&prot_it)) continue;
580                                 de_element_get_uint16(des_iterator_get_element(&prot_it), &avrcp_sdp_query_context.avrcp_l2cap_psm);
581                                 break;
582                             case BLUETOOTH_PROTOCOL_AVCTP:
583                                 if (!des_iterator_has_more(&prot_it)) continue;
584                                 de_element_get_uint16(des_iterator_get_element(&prot_it), &avrcp_sdp_query_context.avrcp_version);
585                                 break;
586                             default:
587                                 break;
588                         }
589                     }
590                 }
591                     break;
592                 case BLUETOOTH_ATTRIBUTE_ADDITIONAL_PROTOCOL_DESCRIPTOR_LISTS: {
593                     // log_info("SDP Attribute: 0x%04x", sdp_event_query_attribute_byte_get_attribute_id(packet));
594                     if (!avrcp_sdp_query_context.parse_sdp_record) break;
595                     if (de_get_element_type(avrcp_sdp_query_attribute_value) != DE_DES) break;
596 
597                     des_iterator_t des_list_0_it;
598                     uint8_t       *element_0;
599 
600                     des_iterator_init(&des_list_0_it, avrcp_sdp_query_attribute_value);
601                     element_0 = des_iterator_get_element(&des_list_0_it);
602 
603                     for (des_iterator_init(&des_list_it, element_0); des_iterator_has_more(&des_list_it); des_iterator_next(&des_list_it)) {
604                         uint8_t       *des_element;
605                         uint8_t       *element;
606                         uint32_t       uuid;
607 
608                         if (des_iterator_get_type(&des_list_it) != DE_DES) continue;
609 
610                         des_element = des_iterator_get_element(&des_list_it);
611                         des_iterator_init(&prot_it, des_element);
612                         element = des_iterator_get_element(&prot_it);
613 
614                         if (de_get_element_type(element) != DE_UUID) continue;
615 
616                         uuid = de_get_uuid32(element);
617                         des_iterator_next(&prot_it);
618                         switch (uuid){
619                             case BLUETOOTH_PROTOCOL_L2CAP:
620                                 if (!des_iterator_has_more(&prot_it)) continue;
621                                 de_element_get_uint16(des_iterator_get_element(&prot_it), &avrcp_sdp_query_context.browsing_l2cap_psm);
622                                 break;
623                             case BLUETOOTH_PROTOCOL_AVCTP:
624                                 if (!des_iterator_has_more(&prot_it)) continue;
625                                 de_element_get_uint16(des_iterator_get_element(&prot_it), &avrcp_sdp_query_context.browsing_version);
626                                 break;
627                             default:
628                                 break;
629                         }
630                     }
631                 }
632                     break;
633                 default:
634                     break;
635             }
636         }
637     } else {
638         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));
639     }
640 }
641 
642 static void avrcp_handle_sdp_query_failed(avrcp_connection_t * connection, uint8_t status){
643     if (connection == NULL) return;
644     log_info("AVRCP: SDP query failed with status 0x%02x.", status);
645     avrcp_emit_connection_established(connection->avrcp_cid, connection->remote_addr, connection->con_handle, status);
646     avrcp_finalize_connection(connection);
647 }
648 
649 static void avrcp_handle_sdp_query_succeeded(avrcp_connection_t * connection){
650     if (connection == NULL) return;
651     connection->state = AVCTP_CONNECTION_W4_L2CAP_CONNECTED;
652     connection->avrcp_l2cap_psm = avrcp_sdp_query_context.avrcp_l2cap_psm;
653     connection->browsing_version = avrcp_sdp_query_context.browsing_version;
654     connection->browsing_l2cap_psm = avrcp_sdp_query_context.browsing_l2cap_psm;
655 }
656 
657 static void avrcp_handle_sdp_client_query_result(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
658     UNUSED(packet_type);
659     UNUSED(channel);
660     UNUSED(size);
661 
662     bool state_ok = true;
663     avrcp_connection_t * avrcp_target_connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_TARGET, avrcp_sdp_query_context.avrcp_cid);
664     if (!avrcp_target_connection || avrcp_target_connection->state != AVCTP_CONNECTION_W4_SDP_QUERY_COMPLETE) {
665         state_ok = false;
666     }
667     avrcp_connection_t * avrcp_controller_connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_sdp_query_context.avrcp_cid);
668     if (!avrcp_controller_connection || avrcp_controller_connection->state != AVCTP_CONNECTION_W4_SDP_QUERY_COMPLETE) {
669         state_ok = false;
670     }
671     if (!state_ok){
672         // something wrong, nevertheless, start next sdp query if this one is complete
673         if (hci_event_packet_get_type(packet) == SDP_EVENT_QUERY_COMPLETE){
674             (void) sdp_client_register_query_callback(&avrcp_sdp_query_registration);
675         }
676         return;
677     }
678 
679     uint8_t status;
680 
681     switch (hci_event_packet_get_type(packet)){
682         case SDP_EVENT_QUERY_ATTRIBUTE_VALUE:
683             avrcp_handle_sdp_client_query_attribute_value(packet);
684             return;
685 
686         case SDP_EVENT_QUERY_COMPLETE:
687             status = sdp_event_query_complete_get_status(packet);
688 
689             if (status != ERROR_CODE_SUCCESS){
690                 avrcp_handle_sdp_query_failed(avrcp_controller_connection, status);
691                 avrcp_handle_sdp_query_failed(avrcp_target_connection, status);
692                 break;
693             }
694 
695             if (!avrcp_sdp_query_context.avrcp_l2cap_psm){
696                 avrcp_handle_sdp_query_failed(avrcp_controller_connection, SDP_SERVICE_NOT_FOUND);
697                 avrcp_handle_sdp_query_failed(avrcp_target_connection, SDP_SERVICE_NOT_FOUND);
698                 break;
699             }
700 
701             avrcp_handle_sdp_query_succeeded(avrcp_controller_connection);
702             avrcp_handle_sdp_query_succeeded(avrcp_target_connection);
703 
704             l2cap_create_channel(&avrcp_packet_handler, avrcp_target_connection->remote_addr, avrcp_sdp_query_context.avrcp_l2cap_psm, l2cap_max_mtu(), NULL);
705             break;
706 
707         default:
708             return;
709     }
710 
711     // register the SDP Query request to check if there is another connection waiting for the query
712     // ignore ERROR_CODE_COMMAND_DISALLOWED because in that case, we already have requested an SDP callback
713     (void) sdp_client_register_query_callback(&avrcp_sdp_query_registration);
714 }
715 
716 
717 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){
718     if (connection == NULL){
719         connection = avrcp_create_connection(role, event_addr);
720     }
721     if (connection) {
722         connection->state = AVCTP_CONNECTION_W4_L2CAP_CONNECTED;
723         connection->l2cap_signaling_cid = local_cid;
724         connection->avrcp_cid = avrcp_cid;
725         connection->con_handle = con_handle;
726         btstack_run_loop_remove_timer(&connection->retry_timer);
727     }
728     return connection;
729 }
730 
731 static void avrcp_handle_open_connection(avrcp_connection_t * connection, hci_con_handle_t con_handle, uint16_t local_cid, uint16_t l2cap_mtu){
732     connection->l2cap_signaling_cid = local_cid;
733     connection->l2cap_mtu = l2cap_mtu;
734     connection->con_handle = con_handle;
735     connection->incoming_declined = false;
736     connection->song_length_ms = 0xFFFFFFFF;
737     connection->song_position_ms = 0xFFFFFFFF;
738     connection->playback_status = AVRCP_PLAYBACK_STATUS_STOPPED;
739     connection->state = AVCTP_CONNECTION_OPENED;
740 
741     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);
742 }
743 
744 static void avrcp_retry_timer_timeout_handler(btstack_timer_source_t * timer){
745     uint16_t avrcp_cid = (uint16_t)(uintptr_t) btstack_run_loop_get_timer_context(timer);
746     avrcp_connection_t * connection_controller = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
747     if (connection_controller == NULL) return;
748     avrcp_connection_t * connection_target = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_TARGET, avrcp_cid);
749     if (connection_target == NULL) return;
750 
751     if (connection_controller->state == AVCTP_CONNECTION_W2_L2CAP_RETRY){
752         connection_controller->state = AVCTP_CONNECTION_W4_L2CAP_CONNECTED;
753         connection_target->state = AVCTP_CONNECTION_W4_L2CAP_CONNECTED;
754         l2cap_create_channel(&avrcp_packet_handler, connection_controller->remote_addr, connection_controller->avrcp_l2cap_psm, l2cap_max_mtu(), NULL);
755     }
756 }
757 
758 static void avrcp_retry_timer_start(avrcp_connection_t * connection){
759     btstack_run_loop_set_timer_handler(&connection->retry_timer, avrcp_retry_timer_timeout_handler);
760     btstack_run_loop_set_timer_context(&connection->retry_timer, (void *)(uintptr_t)connection->avrcp_cid);
761 
762     // add some jitter/randomness to reconnect delay
763     uint32_t timeout = 100 + (btstack_run_loop_get_time_ms() & 0x7F);
764     btstack_run_loop_set_timer(&connection->retry_timer, timeout);
765 
766     btstack_run_loop_add_timer(&connection->retry_timer);
767 }
768 
769 static avrcp_frame_type_t avrcp_get_frame_type(uint8_t header){
770     return (avrcp_frame_type_t)((header & 0x02) >> 1);
771 }
772 
773 static void avrcp_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
774     UNUSED(channel);
775     UNUSED(size);
776     bd_addr_t event_addr;
777     uint16_t local_cid;
778     uint16_t l2cap_mtu;
779     uint8_t  status;
780     bool decline_connection;
781     bool outoing_active;
782     hci_con_handle_t con_handle;
783 
784     avrcp_connection_t * connection_controller;
785     avrcp_connection_t * connection_target;
786     bool can_send;
787 
788     switch (packet_type) {
789         case HCI_EVENT_PACKET:
790             switch (hci_event_packet_get_type(packet)) {
791 
792                 case L2CAP_EVENT_INCOMING_CONNECTION:
793                     btstack_assert(avrcp_controller_packet_handler != NULL);
794                     btstack_assert(avrcp_target_packet_handler != NULL);
795 
796                     l2cap_event_incoming_connection_get_address(packet, event_addr);
797                     local_cid = l2cap_event_incoming_connection_get_local_cid(packet);
798                     con_handle = l2cap_event_incoming_connection_get_handle(packet);
799 
800                     outoing_active = false;
801                     connection_target = avrcp_get_connection_for_bd_addr_for_role(AVRCP_TARGET, event_addr);
802                     if (connection_target != NULL){
803                         if (connection_target->state == AVCTP_CONNECTION_W4_L2CAP_CONNECTED){
804                             outoing_active = true;
805                             connection_target->incoming_declined = true;
806                         }
807                     }
808 
809                     connection_controller = avrcp_get_connection_for_bd_addr_for_role(AVRCP_CONTROLLER, event_addr);
810                     if (connection_controller != NULL){
811                         if (connection_controller->state == AVCTP_CONNECTION_W4_L2CAP_CONNECTED) {
812                             outoing_active = true;
813                             connection_controller->incoming_declined = true;
814                         }
815                     }
816 
817                     decline_connection = outoing_active;
818                     if (decline_connection == false){
819                         uint16_t avrcp_cid;
820                         if ((connection_controller == NULL) || (connection_target == NULL)){
821                             avrcp_cid = avrcp_get_next_cid(AVRCP_CONTROLLER);
822                         } else {
823                             avrcp_cid = connection_controller->avrcp_cid;
824                         }
825                         // create two connection objects (both)
826                         connection_target     = avrcp_handle_incoming_connection_for_role(AVRCP_TARGET, connection_target, event_addr, con_handle, local_cid, avrcp_cid);
827                         connection_controller = avrcp_handle_incoming_connection_for_role(AVRCP_CONTROLLER, connection_controller, event_addr, con_handle, local_cid, avrcp_cid);
828                         if ((connection_target == NULL) || (connection_controller == NULL)){
829                             decline_connection = true;
830                             if (connection_target) {
831                                 avrcp_finalize_connection(connection_target);
832                             }
833                             if (connection_controller) {
834                                 avrcp_finalize_connection(connection_controller);
835                             }
836                         }
837                     }
838                     if (decline_connection){
839                         l2cap_decline_connection(local_cid);
840                     } else {
841                         log_info("AVRCP: L2CAP_EVENT_INCOMING_CONNECTION local cid 0x%02x, state %d", local_cid, connection_controller->state);
842                         l2cap_accept_connection(local_cid);
843                     }
844                     break;
845 
846                 case L2CAP_EVENT_CHANNEL_OPENED:
847                     l2cap_event_channel_opened_get_address(packet, event_addr);
848                     status = l2cap_event_channel_opened_get_status(packet);
849                     local_cid = l2cap_event_channel_opened_get_local_cid(packet);
850                     l2cap_mtu = l2cap_event_channel_opened_get_remote_mtu(packet);
851                     con_handle = l2cap_event_channel_opened_get_handle(packet);
852 
853                     connection_controller = avrcp_get_connection_for_bd_addr_for_role(AVRCP_CONTROLLER, event_addr);
854                     connection_target = avrcp_get_connection_for_bd_addr_for_role(AVRCP_TARGET, event_addr);
855 
856                     // incoming: structs are already created in L2CAP_EVENT_INCOMING_CONNECTION
857                     // outgoing: structs are cteated in avrcp_connect()
858                     if ((connection_controller == NULL) || (connection_target == NULL)) {
859                         break;
860                     }
861 
862                     switch (status){
863                         case ERROR_CODE_SUCCESS:
864                             avrcp_handle_open_connection(connection_target, con_handle, local_cid, l2cap_mtu);
865                             avrcp_handle_open_connection(connection_controller, con_handle, local_cid, l2cap_mtu);
866                             avrcp_emit_connection_established(connection_controller->avrcp_cid, event_addr, con_handle, status);
867                             return;
868                         case L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_RESOURCES:
869                             if (connection_controller->incoming_declined == true){
870                                 log_info("Incoming connection was declined, and the outgoing failed");
871                                 connection_controller->state = AVCTP_CONNECTION_W2_L2CAP_RETRY;
872                                 connection_controller->incoming_declined = false;
873                                 connection_target->state = AVCTP_CONNECTION_W2_L2CAP_RETRY;
874                                 connection_target->incoming_declined = false;
875                                 avrcp_retry_timer_start(connection_controller);
876                                 return;
877                             }
878                             break;
879                         default:
880                             break;
881                     }
882                     log_info("L2CAP connection to connection %s failed. status code 0x%02x", bd_addr_to_str(event_addr), status);
883                     avrcp_emit_connection_established(connection_controller->avrcp_cid, event_addr, con_handle, status);
884                     avrcp_finalize_connection(connection_controller);
885                     avrcp_finalize_connection(connection_target);
886 
887                     break;
888 
889                 case L2CAP_EVENT_CHANNEL_CLOSED:
890                     local_cid = l2cap_event_channel_closed_get_local_cid(packet);
891 
892                     connection_controller = avrcp_get_connection_for_l2cap_signaling_cid_for_role(AVRCP_CONTROLLER, local_cid);
893                     connection_target = avrcp_get_connection_for_l2cap_signaling_cid_for_role(AVRCP_TARGET, local_cid);
894                     if ((connection_controller == NULL) || (connection_target == NULL)) {
895                         break;
896                     }
897                     avrcp_emit_connection_closed(connection_controller->avrcp_cid);
898                     avrcp_finalize_connection(connection_controller);
899                     avrcp_finalize_connection(connection_target);
900                     break;
901 
902                 case L2CAP_EVENT_CAN_SEND_NOW:
903                     local_cid = l2cap_event_can_send_now_get_local_cid(packet);
904                     can_send = true;
905 
906                     connection_target = avrcp_get_connection_for_l2cap_signaling_cid_for_role(AVRCP_TARGET, local_cid);
907                     if ((connection_target != NULL) && connection_target->wait_to_send){
908                         connection_target->wait_to_send = false;
909                         (*avrcp_target_packet_handler)(HCI_EVENT_PACKET, channel, packet, size);
910                         can_send = false;
911                     }
912 
913                     connection_controller = avrcp_get_connection_for_l2cap_signaling_cid_for_role(AVRCP_CONTROLLER, local_cid);
914                     if ((connection_controller != NULL) && connection_controller->wait_to_send){
915                         if (can_send){
916                             connection_controller->wait_to_send = false;
917                             (*avrcp_controller_packet_handler)(HCI_EVENT_PACKET, channel, packet, size);
918                         } else {
919                             l2cap_request_can_send_now_event(local_cid);
920                         }
921                     }
922                     break;
923 
924                 default:
925                     break;
926             }
927             break;
928 
929         case L2CAP_DATA_PACKET:
930             switch (avrcp_get_frame_type(packet[0])){
931                 case AVRCP_RESPONSE_FRAME:
932                     (*avrcp_controller_packet_handler)(packet_type, channel, packet, size);
933                     break;
934                 case AVRCP_COMMAND_FRAME:
935                 default:    // make compiler happy
936                     (*avrcp_target_packet_handler)(packet_type, channel, packet, size);
937                     break;
938             }
939             break;
940 
941         default:
942             break;
943     }
944 }
945 
946 uint8_t avrcp_disconnect(uint16_t avrcp_cid){
947     avrcp_connection_t * connection_controller = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
948     if (!connection_controller){
949         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
950     }
951     avrcp_connection_t * connection_target = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_TARGET, avrcp_cid);
952     if (!connection_target){
953         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
954     }
955     if (connection_controller->browsing_connection){
956         l2cap_disconnect(connection_controller->browsing_connection->l2cap_browsing_cid);
957     }
958     l2cap_disconnect(connection_controller->l2cap_signaling_cid);
959     return ERROR_CODE_SUCCESS;
960 }
961 
962 static void avrcp_handle_start_sdp_client_query(void * context){
963     UNUSED(context);
964 
965     btstack_linked_list_iterator_t it;
966     btstack_linked_list_iterator_init(&it, &avrcp_connections);
967     while (btstack_linked_list_iterator_has_next(&it)){
968         avrcp_connection_t * connection = (avrcp_connection_t *)btstack_linked_list_iterator_next(&it);
969 
970         if (connection->state != AVCTP_CONNECTION_W2_SEND_SDP_QUERY) continue;
971         connection->state = AVCTP_CONNECTION_W4_SDP_QUERY_COMPLETE;
972 
973         // prevent triggering SDP query twice (for each role once)
974         avrcp_connection_t * connection_with_opposite_role;
975         switch (connection->role){
976             case AVRCP_CONTROLLER:
977                 connection_with_opposite_role = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_TARGET, connection->avrcp_cid);
978                 break;
979             case AVRCP_TARGET:
980                 connection_with_opposite_role = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, connection->avrcp_cid);
981                 break;
982             default:
983                 btstack_assert(false);
984                 return;
985         }
986         connection_with_opposite_role->state = AVCTP_CONNECTION_W4_SDP_QUERY_COMPLETE;
987 
988         avrcp_sdp_query_context.avrcp_l2cap_psm = 0;
989         avrcp_sdp_query_context.avrcp_version  = 0;
990         avrcp_sdp_query_context.avrcp_cid = connection->avrcp_cid;
991         sdp_client_query_uuid16(&avrcp_handle_sdp_client_query_result, (uint8_t *) connection->remote_addr, BLUETOOTH_PROTOCOL_AVCTP);
992         return;
993     }
994 }
995 
996 uint8_t avrcp_connect(bd_addr_t remote_addr, uint16_t * avrcp_cid){
997     btstack_assert(avrcp_controller_packet_handler != NULL);
998     btstack_assert(avrcp_target_packet_handler != NULL);
999 
1000     avrcp_connection_t * connection_controller = avrcp_get_connection_for_bd_addr_for_role(AVRCP_CONTROLLER, remote_addr);
1001     if (connection_controller){
1002         return ERROR_CODE_COMMAND_DISALLOWED;
1003     }
1004     avrcp_connection_t * connection_target = avrcp_get_connection_for_bd_addr_for_role(AVRCP_TARGET, remote_addr);
1005     if (connection_target){
1006         return ERROR_CODE_COMMAND_DISALLOWED;
1007     }
1008 
1009     uint16_t cid = avrcp_get_next_cid(AVRCP_CONTROLLER);
1010 
1011     connection_controller = avrcp_create_connection(AVRCP_CONTROLLER, remote_addr);
1012     if (!connection_controller) return BTSTACK_MEMORY_ALLOC_FAILED;
1013 
1014     connection_target = avrcp_create_connection(AVRCP_TARGET, remote_addr);
1015     if (!connection_target){
1016         avrcp_finalize_connection(connection_controller);
1017         return BTSTACK_MEMORY_ALLOC_FAILED;
1018     }
1019 
1020     if (avrcp_cid != NULL){
1021         *avrcp_cid = cid;
1022     }
1023 
1024     connection_controller->state = AVCTP_CONNECTION_W2_SEND_SDP_QUERY;
1025     connection_controller->avrcp_cid = cid;
1026 
1027     connection_target->state     = AVCTP_CONNECTION_W2_SEND_SDP_QUERY;
1028     connection_target->avrcp_cid = cid;
1029 
1030     avrcp_sdp_query_registration.callback = &avrcp_handle_start_sdp_client_query;
1031     // ignore ERROR_CODE_COMMAND_DISALLOWED because in that case, we already have requested an SDP callback
1032     (void) sdp_client_register_query_callback(&avrcp_sdp_query_registration);
1033     return ERROR_CODE_SUCCESS;
1034 }
1035 
1036 void avrcp_init(void){
1037     avrcp_connections = NULL;
1038     if (avrcp_l2cap_service_registered) return;
1039 
1040     int status = l2cap_register_service(&avrcp_packet_handler, BLUETOOTH_PSM_AVCTP, 0xffff, gap_get_security_level());
1041     if (status != ERROR_CODE_SUCCESS) return;
1042     avrcp_l2cap_service_registered = true;
1043 }
1044 
1045 void avrcp_deinit(void){
1046     avrcp_l2cap_service_registered = false;
1047 
1048     avrcp_cid_counter = 0;
1049     avrcp_connections = NULL;
1050 
1051     avrcp_callback = NULL;
1052     avrcp_controller_packet_handler = NULL;
1053     avrcp_target_packet_handler = NULL;
1054 
1055     (void) memset(&avrcp_sdp_query_registration, 0, sizeof(avrcp_sdp_query_registration));
1056     (void) memset(&avrcp_sdp_query_context, 0, sizeof(avrcp_sdp_query_context_t));
1057     (void) memset(avrcp_sdp_query_attribute_value, 0, sizeof(avrcp_sdp_query_attribute_value));
1058 }
1059 
1060 void avrcp_register_controller_packet_handler(btstack_packet_handler_t callback){
1061     avrcp_controller_packet_handler = callback;
1062 }
1063 
1064 void avrcp_register_target_packet_handler(btstack_packet_handler_t callback){
1065     avrcp_target_packet_handler = callback;
1066 }
1067 
1068 void avrcp_register_packet_handler(btstack_packet_handler_t callback){
1069     btstack_assert(callback != NULL);
1070     avrcp_callback = callback;
1071 }
1072 
1073 #ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
1074 #define FUZZ_CID 0x44
1075 #define FUZZ_CON_HANDLE 0x0001
1076 static bd_addr_t remote_addr = { 0x33, 0x33, 0x33, 0x33, 0x33, 0x33 };
1077 void avrcp_init_fuzz(void){
1078     // setup avrcp connections for cid
1079     avrcp_connection_t * connection_controller = avrcp_create_connection(AVRCP_CONTROLLER, remote_addr);
1080     avrcp_connection_t * connection_target     = avrcp_create_connection(AVRCP_TARGET, remote_addr);
1081     avrcp_handle_open_connection(connection_controller, FUZZ_CON_HANDLE, FUZZ_CID, 999);
1082     avrcp_handle_open_connection(connection_target, FUZZ_CON_HANDLE, FUZZ_CID, 999);
1083 }
1084 void avrcp_packet_handler_fuzz(uint8_t *packet, uint16_t size){
1085     avrcp_packet_handler(L2CAP_DATA_PACKET, FUZZ_CID, packet, size);
1086 }
1087 #endif