xref: /btstack/src/classic/avrcp.c (revision d58a1b5f11ada8ddf896c41fff5a35e7f140c37e)
1 /*
2  * Copyright (C) 2016 BlueKitchen GmbH
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the copyright holders nor the names of
14  *    contributors may be used to endorse or promote products derived
15  *    from this software without specific prior written permission.
16  * 4. Any redistribution, use, or modification is done solely for
17  *    personal benefit and not for any commercial purpose or for
18  *    monetary gain.
19  *
20  * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS
24  * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
27  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
30  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * Please inquire about commercial licensing options at
34  * [email protected]
35  *
36  */
37 
38 #define BTSTACK_FILE__ "avrcp.c"
39 
40 #include <stdint.h>
41 #include <string.h>
42 
43 #include "bluetooth_psm.h"
44 #include "bluetooth_sdp.h"
45 #include "btstack_debug.h"
46 #include "btstack_event.h"
47 #include "btstack_memory.h"
48 #include "classic/sdp_client.h"
49 #include "classic/sdp_util.h"
50 #include "classic/avrcp.h"
51 #include "classic/avrcp_controller.h"
52 
53 static void avrcp_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
54 
55 static const char * default_avrcp_controller_service_name = "BTstack AVRCP Controller Service";
56 static const char * default_avrcp_controller_service_provider_name = "BTstack AVRCP Controller Service Provider";
57 static const char * default_avrcp_target_service_name = "BTstack AVRCP Target Service";
58 static const char * default_avrcp_target_service_provider_name = "BTstack AVRCP Target Service Provider";
59 
60 static uint16_t  avrcp_cid_counter = 0;
61 
62 static avrcp_context_t * sdp_query_context;
63 static uint8_t   attribute_value[1000];
64 static const unsigned int attribute_value_buffer_size = sizeof(attribute_value);
65 
66 static btstack_linked_list_t connections;
67 static btstack_packet_handler_t avrcp_controller_packet_handler;
68 static btstack_packet_handler_t avrcp_target_packet_handler;
69 static int l2cap_service_registered = 0;
70 
71 static const char * avrcp_subunit_type_name[] = {
72     "MONITOR", "AUDIO", "PRINTER", "DISC", "TAPE_RECORDER_PLAYER", "TUNER",
73     "CA", "CAMERA", "RESERVED", "PANEL", "BULLETIN_BOARD", "CAMERA_STORAGE",
74     "VENDOR_UNIQUE", "RESERVED_FOR_ALL_SUBUNIT_TYPES",
75     "EXTENDED_TO_NEXT_BYTE", "UNIT", "ERROR"
76 };
77 
78 const char * avrcp_subunit2str(uint16_t index){
79     if (index <= 11) return avrcp_subunit_type_name[index];
80     if ((index >= 0x1C) && (index <= 0x1F)) return avrcp_subunit_type_name[index - 0x10];
81     return avrcp_subunit_type_name[16];
82 }
83 
84 static const char * avrcp_event_name[] = {
85     "ERROR", "PLAYBACK_STATUS_CHANGED",
86     "TRACK_CHANGED", "TRACK_REACHED_END", "TRACK_REACHED_START",
87     "PLAYBACK_POS_CHANGED", "BATT_STATUS_CHANGED", "SYSTEM_STATUS_CHANGED",
88     "PLAYER_APPLICATION_SETTING_CHANGED", "NOW_PLAYING_CONTENT_CHANGED",
89     "AVAILABLE_PLAYERS_CHANGED", "ADDRESSED_PLAYER_CHANGED", "UIDS_CHANGED", "VOLUME_CHANGED"
90 };
91 const char * avrcp_event2str(uint16_t index){
92     if (index <= 0x0d) return avrcp_event_name[index];
93     return avrcp_event_name[0];
94 }
95 
96 static const char * avrcp_operation_name[] = {
97     "NOT SUPPORTED", // 0x3B
98     "SKIP", "NOT SUPPORTED", "NOT SUPPORTED", "NOT SUPPORTED", "NOT SUPPORTED",
99     "VOLUME_UP", "VOLUME_DOWN", "MUTE", "PLAY", "STOP", "PAUSE", "NOT SUPPORTED",
100     "REWIND", "FAST_FORWARD", "NOT SUPPORTED", "FORWARD", "BACKWARD" // 0x4C
101 };
102 const char * avrcp_operation2str(uint8_t index){
103     if ((index >= 0x3B) && (index <= 0x4C)) return avrcp_operation_name[index - 0x3B];
104     return avrcp_operation_name[0];
105 }
106 
107 static const char * avrcp_media_attribute_id_name[] = {
108     "NONE", "TITLE", "ARTIST", "ALBUM", "TRACK", "TOTAL TRACKS", "GENRE", "SONG LENGTH"
109 };
110 const char * avrcp_attribute2str(uint8_t index){
111     if ((index >= 1) && (index <= 7)) return avrcp_media_attribute_id_name[index];
112     return avrcp_media_attribute_id_name[0];
113 }
114 
115 static const char * avrcp_play_status_name[] = {
116     "STOPPED", "PLAYING", "PAUSED", "FORWARD SEEK", "REVERSE SEEK",
117     "ERROR" // 0xFF
118 };
119 const char * avrcp_play_status2str(uint8_t index){
120     if ((index >= 1) && (index <= 4)) return avrcp_play_status_name[index];
121     return avrcp_play_status_name[5];
122 }
123 
124 static const char * avrcp_ctype_name[] = {
125     "CONTROL",
126     "STATUS",
127     "SPECIFIC_INQUIRY",
128     "NOTIFY",
129     "GENERAL_INQUIRY",
130     "RESERVED5",
131     "RESERVED6",
132     "RESERVED7",
133     "NOT IMPLEMENTED IN REMOTE",
134     "ACCEPTED BY REMOTE",
135     "REJECTED BY REMOTE",
136     "IN_TRANSITION",
137     "IMPLEMENTED_STABLE",
138     "CHANGED_STABLE",
139     "RESERVED",
140     "INTERIM"
141 };
142 const char * avrcp_ctype2str(uint8_t index){
143     if (index < sizeof(avrcp_ctype_name)){
144         return avrcp_ctype_name[index];
145     }
146     return "NONE";
147 }
148 
149 static const char * avrcp_shuffle_mode_name[] = {
150     "SHUFFLE OFF",
151     "SHUFFLE ALL TRACKS",
152     "SHUFFLE GROUP"
153 };
154 
155 const char * avrcp_shuffle2str(uint8_t index){
156     if ((index >= 1) && (index <= 3)) return avrcp_shuffle_mode_name[index-1];
157     return "NONE";
158 }
159 
160 static const char * avrcp_repeat_mode_name[] = {
161     "REPEAT OFF",
162     "REPEAT SINGLE TRACK",
163     "REPEAT ALL TRACKS",
164     "REPEAT GROUP"
165 };
166 
167 const char * avrcp_repeat2str(uint8_t index){
168     if ((index >= 1) && (index <= 4)) return avrcp_repeat_mode_name[index-1];
169     return "NONE";
170 }
171 
172 uint8_t avrcp_cmd_opcode(uint8_t *packet, uint16_t size){
173     uint8_t cmd_opcode_index = 5;
174     if (cmd_opcode_index > size) return AVRCP_CMD_OPCODE_UNDEFINED;
175     return packet[cmd_opcode_index];
176 }
177 
178 void avrcp_create_sdp_record(uint8_t controller, uint8_t * service, uint32_t service_record_handle, uint8_t browsing, uint16_t supported_features,
179     const char * service_name, const char * service_provider_name){
180     uint8_t* attribute;
181     de_create_sequence(service);
182 
183     // 0x0000 "Service Record Handle"
184     de_add_number(service, DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_SERVICE_RECORD_HANDLE);
185     de_add_number(service, DE_UINT, DE_SIZE_32, service_record_handle);
186 
187     // 0x0001 "Service Class ID List"
188     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_SERVICE_CLASS_ID_LIST);
189     attribute = de_push_sequence(service);
190     {
191         if (controller){
192             de_add_number(attribute, DE_UUID, DE_SIZE_16, BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL);
193             de_add_number(attribute, DE_UUID, DE_SIZE_16, BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL_CONTROLLER);
194         } else {
195             de_add_number(attribute, DE_UUID, DE_SIZE_16, BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL_TARGET);
196         }
197     }
198     de_pop_sequence(service, attribute);
199 
200     // 0x0004 "Protocol Descriptor List"
201     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_PROTOCOL_DESCRIPTOR_LIST);
202     attribute = de_push_sequence(service);
203     {
204         uint8_t* l2cpProtocol = de_push_sequence(attribute);
205         {
206             de_add_number(l2cpProtocol,  DE_UUID, DE_SIZE_16, BLUETOOTH_PROTOCOL_L2CAP);
207             de_add_number(l2cpProtocol,  DE_UINT, DE_SIZE_16, BLUETOOTH_PSM_AVCTP);
208         }
209         de_pop_sequence(attribute, l2cpProtocol);
210 
211         uint8_t* avctpProtocol = de_push_sequence(attribute);
212         {
213             de_add_number(avctpProtocol,  DE_UUID, DE_SIZE_16, BLUETOOTH_PROTOCOL_AVCTP);  // avctpProtocol_service
214             de_add_number(avctpProtocol,  DE_UINT, DE_SIZE_16,  0x0103);    // version
215         }
216         de_pop_sequence(attribute, avctpProtocol);
217     }
218     de_pop_sequence(service, attribute);
219 
220     // 0x0005 "Public Browse Group"
221     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_BROWSE_GROUP_LIST); // public browse group
222     attribute = de_push_sequence(service);
223     {
224         de_add_number(attribute,  DE_UUID, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_PUBLIC_BROWSE_ROOT);
225     }
226     de_pop_sequence(service, attribute);
227 
228     // 0x0009 "Bluetooth Profile Descriptor List"
229     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_BLUETOOTH_PROFILE_DESCRIPTOR_LIST);
230     attribute = de_push_sequence(service);
231     {
232         uint8_t *avrcProfile = de_push_sequence(attribute);
233         {
234             de_add_number(avrcProfile,  DE_UUID, DE_SIZE_16, BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL);
235             de_add_number(avrcProfile,  DE_UINT, DE_SIZE_16, 0x0105);
236         }
237         de_pop_sequence(attribute, avrcProfile);
238     }
239     de_pop_sequence(service, attribute);
240 
241     // 0x000d "Additional Bluetooth Profile Descriptor List"
242     if (browsing){
243         de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_ADDITIONAL_PROTOCOL_DESCRIPTOR_LISTS);
244         attribute = de_push_sequence(service);
245         {
246             uint8_t * des = de_push_sequence(attribute);
247             {
248                 uint8_t* browsing_l2cpProtocol = de_push_sequence(des);
249                 {
250                     de_add_number(browsing_l2cpProtocol,  DE_UUID, DE_SIZE_16, BLUETOOTH_PROTOCOL_L2CAP);
251                     de_add_number(browsing_l2cpProtocol,  DE_UINT, DE_SIZE_16, BLUETOOTH_PSM_AVCTP_BROWSING);
252                 }
253                 de_pop_sequence(des, browsing_l2cpProtocol);
254 
255                 uint8_t* browsing_avctpProtocol = de_push_sequence(des);
256                 {
257                     de_add_number(browsing_avctpProtocol,  DE_UUID, DE_SIZE_16, BLUETOOTH_PROTOCOL_AVCTP);  // browsing_avctpProtocol_service
258                     de_add_number(browsing_avctpProtocol,  DE_UINT, DE_SIZE_16,  0x0103);    // version
259                 }
260                 de_pop_sequence(des, browsing_avctpProtocol);
261             }
262             de_pop_sequence(attribute, des);
263         }
264         de_pop_sequence(service, attribute);
265     }
266 
267 
268     // 0x0100 "Service Name"
269     de_add_number(service,  DE_UINT, DE_SIZE_16, 0x0100);
270     if (service_name){
271         de_add_data(service,  DE_STRING, strlen(service_name), (uint8_t *) service_name);
272     } else {
273         if (controller){
274             de_add_data(service,  DE_STRING, strlen(default_avrcp_controller_service_name), (uint8_t *) default_avrcp_controller_service_name);
275         } else {
276             de_add_data(service,  DE_STRING, strlen(default_avrcp_target_service_name), (uint8_t *) default_avrcp_target_service_name);
277         }
278     }
279 
280     // 0x0100 "Provider Name"
281     de_add_number(service,  DE_UINT, DE_SIZE_16, 0x0102);
282     if (service_provider_name){
283         de_add_data(service,  DE_STRING, strlen(service_provider_name), (uint8_t *) service_provider_name);
284     } else {
285         if (controller){
286             de_add_data(service,  DE_STRING, strlen(default_avrcp_controller_service_provider_name), (uint8_t *) default_avrcp_controller_service_provider_name);
287         } else {
288             de_add_data(service,  DE_STRING, strlen(default_avrcp_target_service_provider_name), (uint8_t *) default_avrcp_target_service_provider_name);
289         }
290     }
291 
292     // 0x0311 "Supported Features"
293     de_add_number(service, DE_UINT, DE_SIZE_16, 0x0311);
294     de_add_number(service, DE_UINT, DE_SIZE_16, supported_features);
295 }
296 
297 avrcp_connection_t * get_avrcp_connection_for_bd_addr(avrcp_role_t role, bd_addr_t addr){
298     btstack_linked_list_iterator_t it;
299     btstack_linked_list_iterator_init(&it, (btstack_linked_list_t *) &connections);
300     while (btstack_linked_list_iterator_has_next(&it)){
301         avrcp_connection_t * connection = (avrcp_connection_t *)btstack_linked_list_iterator_next(&it);
302         if (connection->role != role) continue;
303         if (memcmp(addr, connection->remote_addr, 6) != 0) continue;
304         return connection;
305     }
306     return NULL;
307 }
308 
309 avrcp_connection_t * get_avrcp_connection_for_l2cap_signaling_cid(avrcp_role_t role, uint16_t l2cap_cid){
310     btstack_linked_list_iterator_t it;
311     btstack_linked_list_iterator_init(&it, (btstack_linked_list_t *) &connections);
312     while (btstack_linked_list_iterator_has_next(&it)){
313         avrcp_connection_t * connection = (avrcp_connection_t *)btstack_linked_list_iterator_next(&it);
314         if (connection->role != role) continue;
315         if (connection->l2cap_signaling_cid != l2cap_cid) continue;
316         return connection;
317     }
318     return NULL;
319 }
320 
321 avrcp_connection_t * get_avrcp_connection_for_avrcp_cid(avrcp_role_t role, uint16_t avrcp_cid){
322     btstack_linked_list_iterator_t it;
323     btstack_linked_list_iterator_init(&it, (btstack_linked_list_t *) &connections);
324     while (btstack_linked_list_iterator_has_next(&it)){
325         avrcp_connection_t * connection = (avrcp_connection_t *)btstack_linked_list_iterator_next(&it);
326         if (connection->role != role) continue;
327         if (connection->avrcp_cid != avrcp_cid) continue;
328         return connection;
329     }
330     return NULL;
331 }
332 
333 avrcp_connection_t * get_avrcp_connection_for_browsing_cid(avrcp_role_t role, uint16_t browsing_cid){
334     btstack_linked_list_iterator_t it;
335     btstack_linked_list_iterator_init(&it, (btstack_linked_list_t *) &connections);
336     while (btstack_linked_list_iterator_has_next(&it)){
337         avrcp_connection_t * connection = (avrcp_connection_t *)btstack_linked_list_iterator_next(&it);
338         if (connection->role != role) continue;
339         if (connection->avrcp_browsing_cid != browsing_cid) continue;
340         return connection;
341     }
342     return NULL;
343 }
344 
345 avrcp_connection_t * get_avrcp_connection_for_browsing_l2cap_cid(avrcp_role_t role, uint16_t browsing_l2cap_cid){
346     btstack_linked_list_iterator_t it;
347     btstack_linked_list_iterator_init(&it, (btstack_linked_list_t *) &connections);
348     while (btstack_linked_list_iterator_has_next(&it)){
349         avrcp_connection_t * connection = (avrcp_connection_t *)btstack_linked_list_iterator_next(&it);
350         if (connection->role != role) continue;
351         if (connection->browsing_connection &&  (connection->browsing_connection->l2cap_browsing_cid != browsing_l2cap_cid)) continue;
352         return connection;
353     }
354     return NULL;
355 }
356 
357 avrcp_browsing_connection_t * get_avrcp_browsing_connection_for_l2cap_cid(avrcp_role_t role, uint16_t l2cap_cid){
358     btstack_linked_list_iterator_t it;
359     btstack_linked_list_iterator_init(&it, (btstack_linked_list_t *) &connections);
360     while (btstack_linked_list_iterator_has_next(&it)){
361         avrcp_connection_t * connection = (avrcp_connection_t *)btstack_linked_list_iterator_next(&it);
362         if (connection->role != role) continue;
363         if (connection->browsing_connection && (connection->browsing_connection->l2cap_browsing_cid != l2cap_cid)) continue;
364         return connection->browsing_connection;
365     }
366     return NULL;
367 }
368 
369 void avrcp_request_can_send_now(avrcp_connection_t * connection, uint16_t l2cap_cid){
370     // printf("AVRCP: avrcp_request_can_send_now, role %d\n", connection->role);
371     connection->wait_to_send = 1;
372     l2cap_request_can_send_now_event(l2cap_cid);
373 }
374 
375 
376 uint16_t avrcp_get_next_cid(avrcp_role_t role){
377     do {
378         if (avrcp_cid_counter == 0xffff) {
379             avrcp_cid_counter = 1;
380         } else {
381             avrcp_cid_counter++;
382         }
383     } while (get_avrcp_connection_for_avrcp_cid(role, avrcp_cid_counter) !=  NULL) ;
384     return avrcp_cid_counter;
385 }
386 
387 
388 static avrcp_connection_t * avrcp_create_connection(avrcp_role_t role, bd_addr_t remote_addr){
389     avrcp_connection_t * connection = btstack_memory_avrcp_connection_get();
390     if (!connection){
391         log_error("Not enough memory to create connection for role %d", role);
392         return NULL;
393     }
394 
395     connection->state = AVCTP_CONNECTION_IDLE;
396     connection->role = role;
397     connection->transaction_label = 0xFF;
398     connection->max_num_fragments = 0xFF;
399     connection->avrcp_cid = avrcp_get_next_cid(role);
400     log_info("avrcp_create_connection, role %d, avrcp cid 0x%02x", role, connection->avrcp_cid);
401     memcpy(connection->remote_addr, remote_addr, 6);
402     btstack_linked_list_add(&connections, (btstack_linked_item_t *) connection);
403     return connection;
404 }
405 
406 static void avrcp_finalize_connection(avrcp_connection_t * connection){
407     btstack_linked_list_remove(&connections, (btstack_linked_item_t*) connection);
408     btstack_memory_avrcp_connection_free(connection);
409 }
410 
411 void avrcp_emit_connection_established(btstack_packet_handler_t callback, uint16_t avrcp_cid, bd_addr_t addr, uint8_t status){
412     if (!callback) return;
413     uint8_t event[12];
414     int pos = 0;
415     event[pos++] = HCI_EVENT_AVRCP_META;
416     event[pos++] = sizeof(event) - 2;
417     event[pos++] = AVRCP_SUBEVENT_CONNECTION_ESTABLISHED;
418     event[pos++] = status;
419     reverse_bd_addr(addr,&event[pos]);
420     pos += 6;
421     little_endian_store_16(event, pos, avrcp_cid);
422     pos += 2;
423     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
424 }
425 
426 void avrcp_emit_connection_closed(btstack_packet_handler_t callback, uint16_t avrcp_cid){
427     if (!callback) return;
428     uint8_t event[5];
429     int pos = 0;
430     event[pos++] = HCI_EVENT_AVRCP_META;
431     event[pos++] = sizeof(event) - 2;
432     event[pos++] = AVRCP_SUBEVENT_CONNECTION_RELEASED;
433     little_endian_store_16(event, pos, avrcp_cid);
434     pos += 2;
435     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
436 }
437 
438 void avrcp_handle_sdp_client_query_result(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
439     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(sdp_query_context->role, sdp_query_context->avrcp_cid);
440     if (!connection) return;
441     if (connection->state != AVCTP_CONNECTION_W4_SDP_QUERY_COMPLETE) return;
442 
443     UNUSED(packet_type);
444     UNUSED(channel);
445     UNUSED(size);
446     uint8_t status;
447     des_iterator_t des_list_it;
448     des_iterator_t prot_it;
449     // uint32_t avdtp_remote_uuid    = 0;
450 
451     switch (hci_event_packet_get_type(packet)){
452         case SDP_EVENT_QUERY_ATTRIBUTE_VALUE:
453             // Handle new SDP record
454             if (sdp_event_query_attribute_byte_get_record_id(packet) != sdp_query_context->record_id) {
455                 sdp_query_context->record_id = sdp_event_query_attribute_byte_get_record_id(packet);
456                 sdp_query_context->parse_sdp_record = 0;
457                 // log_info("SDP Record: Nr: %d", record_id);
458             }
459 
460             if (sdp_event_query_attribute_byte_get_attribute_length(packet) <= attribute_value_buffer_size) {
461                 attribute_value[sdp_event_query_attribute_byte_get_data_offset(packet)] = sdp_event_query_attribute_byte_get_data(packet);
462 
463                 if ((uint16_t)(sdp_event_query_attribute_byte_get_data_offset(packet)+1) == sdp_event_query_attribute_byte_get_attribute_length(packet)) {
464                     switch(sdp_event_query_attribute_byte_get_attribute_id(packet)) {
465                         case BLUETOOTH_ATTRIBUTE_SERVICE_CLASS_ID_LIST:
466                             if (de_get_element_type(attribute_value) != DE_DES) break;
467                             for (des_iterator_init(&des_list_it, attribute_value); des_iterator_has_more(&des_list_it); des_iterator_next(&des_list_it)) {
468                                 uint8_t * element = des_iterator_get_element(&des_list_it);
469                                 if (de_get_element_type(element) != DE_UUID) continue;
470                                 uint32_t uuid = de_get_uuid32(element);
471                                 switch (uuid){
472                                     case BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL_TARGET:
473                                         if (sdp_query_context->role == AVRCP_CONTROLLER) {
474                                             sdp_query_context->parse_sdp_record = 1;
475                                             break;
476                                         }
477                                         break;
478                                     case BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL:
479                                     case BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL_CONTROLLER:
480                                         if (sdp_query_context->role == AVRCP_TARGET) {
481                                             sdp_query_context->parse_sdp_record = 1;
482                                             break;
483                                         }
484                                         break;
485                                     default:
486                                         break;
487                                 }
488                             }
489                             break;
490 
491                         case BLUETOOTH_ATTRIBUTE_PROTOCOL_DESCRIPTOR_LIST: {
492                                 if (!sdp_query_context->parse_sdp_record) break;
493                                 // log_info("SDP Attribute: 0x%04x", sdp_event_query_attribute_byte_get_attribute_id(packet));
494                                 for (des_iterator_init(&des_list_it, attribute_value); des_iterator_has_more(&des_list_it); des_iterator_next(&des_list_it)) {
495                                     uint8_t       *des_element;
496                                     uint8_t       *element;
497                                     uint32_t       uuid;
498 
499                                     if (des_iterator_get_type(&des_list_it) != DE_DES) continue;
500 
501                                     des_element = des_iterator_get_element(&des_list_it);
502                                     des_iterator_init(&prot_it, des_element);
503                                     element = des_iterator_get_element(&prot_it);
504 
505                                     if (de_get_element_type(element) != DE_UUID) continue;
506 
507                                     uuid = de_get_uuid32(element);
508                                     des_iterator_next(&prot_it);
509                                     switch (uuid){
510                                         case BLUETOOTH_PROTOCOL_L2CAP:
511                                             if (!des_iterator_has_more(&prot_it)) continue;
512                                             de_element_get_uint16(des_iterator_get_element(&prot_it), &sdp_query_context->avrcp_l2cap_psm);
513                                             break;
514                                         case BLUETOOTH_PROTOCOL_AVCTP:
515                                             if (!des_iterator_has_more(&prot_it)) continue;
516                                             de_element_get_uint16(des_iterator_get_element(&prot_it), &sdp_query_context->avrcp_version);
517                                             break;
518                                         default:
519                                             break;
520                                     }
521                                 }
522                             }
523                             break;
524                         case BLUETOOTH_ATTRIBUTE_ADDITIONAL_PROTOCOL_DESCRIPTOR_LISTS: {
525                                 // log_info("SDP Attribute: 0x%04x", sdp_event_query_attribute_byte_get_attribute_id(packet));
526                                 if (!sdp_query_context->parse_sdp_record) break;
527                                 if (de_get_element_type(attribute_value) != DE_DES) break;
528 
529                                 des_iterator_t des_list_0_it;
530                                 uint8_t       *element_0;
531 
532                                 des_iterator_init(&des_list_0_it, attribute_value);
533                                 element_0 = des_iterator_get_element(&des_list_0_it);
534 
535                                 for (des_iterator_init(&des_list_it, element_0); des_iterator_has_more(&des_list_it); des_iterator_next(&des_list_it)) {
536                                     uint8_t       *des_element;
537                                     uint8_t       *element;
538                                     uint32_t       uuid;
539 
540                                     if (des_iterator_get_type(&des_list_it) != DE_DES) continue;
541 
542                                     des_element = des_iterator_get_element(&des_list_it);
543                                     des_iterator_init(&prot_it, des_element);
544                                     element = des_iterator_get_element(&prot_it);
545 
546                                     if (de_get_element_type(element) != DE_UUID) continue;
547 
548                                     uuid = de_get_uuid32(element);
549                                     des_iterator_next(&prot_it);
550                                     switch (uuid){
551                                         case BLUETOOTH_PROTOCOL_L2CAP:
552                                             if (!des_iterator_has_more(&prot_it)) continue;
553                                             de_element_get_uint16(des_iterator_get_element(&prot_it), &connection->browsing_l2cap_psm);
554                                             break;
555                                         case BLUETOOTH_PROTOCOL_AVCTP:
556                                             if (!des_iterator_has_more(&prot_it)) continue;
557                                             de_element_get_uint16(des_iterator_get_element(&prot_it), &connection->browsing_version);
558                                             break;
559                                         default:
560                                             break;
561                                     }
562                                 }
563                             }
564                             break;
565                         default:
566                             break;
567                     }
568                 }
569             } else {
570                 log_error("SDP attribute value buffer size exceeded: available %d, required %d", attribute_value_buffer_size, sdp_event_query_attribute_byte_get_attribute_length(packet));
571             }
572             break;
573 
574         case SDP_EVENT_QUERY_COMPLETE:{
575             status = sdp_event_query_complete_get_status(packet);
576 
577             if (status != ERROR_CODE_SUCCESS){
578                 log_info("AVRCP: SDP query failed with status 0x%02x.", status);
579                 avrcp_emit_connection_established(sdp_query_context->avrcp_callback, connection->avrcp_cid, connection->remote_addr, status);
580                 avrcp_finalize_connection(connection);
581                 break;
582             }
583 
584             if (!sdp_query_context->avrcp_l2cap_psm){
585                 connection->state = AVCTP_CONNECTION_IDLE;
586                 log_info("AVRCP: no suitable service found");
587                 avrcp_emit_connection_established(sdp_query_context->avrcp_callback, connection->avrcp_cid, connection->remote_addr, SDP_SERVICE_NOT_FOUND);
588                 avrcp_finalize_connection(connection);
589                 break;
590             }
591             connection->state = AVCTP_CONNECTION_W4_L2CAP_CONNECTED;
592             l2cap_create_channel(&avrcp_packet_handler, connection->remote_addr, sdp_query_context->avrcp_l2cap_psm, l2cap_max_mtu(), NULL);
593             break;
594         }
595     }
596 }
597 
598 static btstack_packet_handler_t avrcp_packet_handler_for_role(avrcp_role_t role){
599     switch (role){
600         case AVRCP_CONTROLLER:
601             return avrcp_controller_packet_handler;
602         case AVRCP_TARGET:
603             return avrcp_target_packet_handler;
604     }
605     return NULL;
606 }
607 
608 static int avrcp_handle_incoming_connection_for_role(avrcp_role_t role, bd_addr_t event_addr, uint16_t local_cid){
609     if (!avrcp_packet_handler_for_role(role)) {
610         // printf("AVRCP: avrcp_handle_incoming_connection_for_role %d, PH not defined\n", role);
611         return 0;
612     }
613 
614     avrcp_connection_t * connection = avrcp_create_connection(role, event_addr);
615     if (!connection) {
616         // printf("AVRCP: avrcp_handle_incoming_connection_for_role %d, no connection created\n", role);
617         return 0 ;
618     }
619 
620     // printf("AVRCP: AVCTP_CONNECTION_W4_L2CAP_CONNECTED, role %d\n", role);
621     connection->state = AVCTP_CONNECTION_W4_L2CAP_CONNECTED;
622     connection->l2cap_signaling_cid = local_cid;
623     return 1;
624 }
625 
626 static void avrcp_handle_open_connection_for_role(avrcp_role_t role, bd_addr_t event_addr, uint16_t local_cid, uint16_t l2cap_mtu, uint8_t status){
627     // printf("AVRCP: avrcp_handle_open_connection_for_role %d\n", role);
628 
629     btstack_packet_handler_t packet_handler = avrcp_packet_handler_for_role(role);
630     if (!packet_handler) {
631         // printf("AVRCP: avrcp_handle_open_connection_for_role %d, PH not defined\n", role);
632         return;
633     }
634     avrcp_connection_t * connection = get_avrcp_connection_for_bd_addr(role, event_addr);
635     if (!connection) {
636         // printf("AVRCP: avrcp_handle_open_connection_for_role %d, no connection found\n", role);
637         return;
638     }
639 
640     if (connection->state == AVCTP_CONNECTION_OPENED) return;
641 
642     if (status != ERROR_CODE_SUCCESS){
643         log_info("L2CAP connection to connection %s failed. status code 0x%02x", bd_addr_to_str(event_addr), status);
644         avrcp_emit_connection_established(packet_handler, connection->avrcp_cid, event_addr, status);
645         avrcp_finalize_connection(connection);
646         return;
647     }
648 
649     connection->l2cap_signaling_cid = local_cid;
650     connection->l2cap_mtu = l2cap_mtu;
651     connection->song_length_ms = 0xFFFFFFFF;
652     connection->song_position_ms = 0xFFFFFFFF;
653     connection->playback_status = AVRCP_PLAYBACK_STATUS_ERROR;
654 
655     log_info("L2CAP_EVENT_CHANNEL_OPENED avrcp_cid 0x%02x, l2cap_signaling_cid 0x%02x, role %d", connection->avrcp_cid, connection->l2cap_signaling_cid, connection->role);
656     connection->state = AVCTP_CONNECTION_OPENED;
657     // emit twice for each role
658     avrcp_emit_connection_established(packet_handler, connection->avrcp_cid, event_addr, ERROR_CODE_SUCCESS);
659 }
660 
661 static void avrcp_handle_close_connection_for_role(avrcp_role_t role,uint16_t local_cid){
662     // printf("AVRCP: avrcp_handle_close_connection_for_role %d\n", role);
663     btstack_packet_handler_t packet_handler = avrcp_packet_handler_for_role(role);
664     if (!packet_handler) return;
665 
666     avrcp_connection_t * connection = get_avrcp_connection_for_l2cap_signaling_cid(role, local_cid);
667     if (!connection) return;
668 
669     // printf("avrcp_handle_close_connection_for_role avrcp_cid 0x%02x, l2cap_signaling_cid 0x%02x, role %d\n", connection->avrcp_cid, connection->l2cap_signaling_cid, role);
670 
671     avrcp_emit_connection_closed(packet_handler, connection->avrcp_cid);
672     avrcp_finalize_connection(connection);
673 }
674 
675 static avrcp_role_t avrcp_role_from_transport_header(uint8_t transport_header){
676     avrcp_frame_type_t frame_type = (avrcp_frame_type_t)((transport_header & 0x02) >> 1);
677     switch (frame_type){
678         case AVRCP_COMMAND_FRAME:
679             return AVRCP_TARGET;
680         default: // AVRCP_RESPONSE_FRAME - make compiler happy
681             return AVRCP_CONTROLLER;
682     }
683 }
684 
685 static void avrcp_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
686     UNUSED(channel);
687     UNUSED(size);
688     bd_addr_t event_addr;
689     uint16_t local_cid;
690     uint16_t l2cap_mtu;
691     uint8_t  status;
692     avrcp_connection_t * connection = NULL;
693     avrcp_role_t role;
694     btstack_packet_handler_t packet_handler;
695     uint8_t status_target;
696     uint8_t status_controller;
697 
698     switch (packet_type) {
699         case L2CAP_DATA_PACKET:
700             role = avrcp_role_from_transport_header(packet[0]);
701             packet_handler = avrcp_packet_handler_for_role(role);
702             if (!packet_handler) return;
703 
704             (*packet_handler)(packet_type, channel, packet, size);
705             break;
706 
707         case HCI_EVENT_PACKET:
708             switch (hci_event_packet_get_type(packet)) {
709 
710                 case L2CAP_EVENT_INCOMING_CONNECTION:
711                     l2cap_event_incoming_connection_get_address(packet, event_addr);
712                     local_cid = l2cap_event_incoming_connection_get_local_cid(packet);
713                     // create two connection objects (both)
714                     status_target = avrcp_handle_incoming_connection_for_role(AVRCP_TARGET, event_addr, local_cid);
715                     status_controller = avrcp_handle_incoming_connection_for_role(AVRCP_CONTROLLER, event_addr, local_cid);
716 
717                     if (!status_target && !status_controller){
718                         l2cap_decline_connection(local_cid);
719                         break;
720                     }
721 
722                     log_info("AVRCP: L2CAP_EVENT_INCOMING_CONNECTION avrcp_cid 0x%02x", local_cid);
723                     l2cap_accept_connection(local_cid);
724                     break;
725 
726                 case L2CAP_EVENT_CHANNEL_OPENED:
727                     // printf("AVRCP: L2CAP_EVENT_CHANNEL_OPENED \n");
728                     l2cap_event_channel_opened_get_address(packet, event_addr);
729                     status = l2cap_event_channel_opened_get_status(packet);
730                     local_cid = l2cap_event_channel_opened_get_local_cid(packet);
731                     l2cap_mtu = l2cap_event_channel_opened_get_remote_mtu(packet);
732 
733                     avrcp_handle_open_connection_for_role(AVRCP_TARGET, event_addr, local_cid, l2cap_mtu, status);
734                     avrcp_handle_open_connection_for_role(AVRCP_CONTROLLER, event_addr, local_cid, l2cap_mtu, status);
735                     break;
736 
737                 case L2CAP_EVENT_CHANNEL_CLOSED:
738                     // data: event (8), len(8), channel (16)
739                     local_cid = l2cap_event_channel_closed_get_local_cid(packet);
740                     avrcp_handle_close_connection_for_role(AVRCP_TARGET, local_cid);
741                     avrcp_handle_close_connection_for_role(AVRCP_CONTROLLER, local_cid);
742                     break;
743 
744                 case L2CAP_EVENT_CAN_SEND_NOW:
745                     local_cid = l2cap_event_can_send_now_get_local_cid(packet);
746                     connection = get_avrcp_connection_for_l2cap_signaling_cid(AVRCP_TARGET, local_cid);
747                     if (connection && connection->wait_to_send){
748                         // printf("AVRCP: L2CAP_EVENT_CAN_SEND_NOW target\n");
749                         connection->wait_to_send = 0;
750                         (*avrcp_target_packet_handler)(HCI_EVENT_PACKET, channel, packet, size);
751                         break;
752                     }
753 
754                     connection = get_avrcp_connection_for_l2cap_signaling_cid(AVRCP_CONTROLLER, local_cid);
755                     if (connection && connection->wait_to_send){
756                         // printf("AVRCP: L2CAP_EVENT_CAN_SEND_NOW controller\n");
757                         connection->wait_to_send = 0;
758                         (*avrcp_controller_packet_handler)(HCI_EVENT_PACKET, channel, packet, size);
759                         break;
760                     }
761                     break;
762 
763                 default:
764                     break;
765             }
766             break;
767         default:
768             break;
769     }
770 }
771 
772 uint8_t avrcp_connect(avrcp_role_t role, bd_addr_t bd_addr, avrcp_context_t * context, uint16_t * avrcp_cid){
773     avrcp_connection_t * connection = get_avrcp_connection_for_bd_addr(context->role, bd_addr);
774     if (connection) return ERROR_CODE_COMMAND_DISALLOWED;
775 
776     if (!sdp_client_ready()) return ERROR_CODE_COMMAND_DISALLOWED;
777 
778     btstack_packet_handler_t packet_handler = avrcp_packet_handler_for_role(role);
779     if (!packet_handler) return 0;
780 
781     connection = avrcp_create_connection(role, bd_addr);
782     if (!connection) return BTSTACK_MEMORY_ALLOC_FAILED;
783 
784     if (avrcp_cid){
785         *avrcp_cid = connection->avrcp_cid;
786     }
787     context->avrcp_l2cap_psm = 0;
788     context->avrcp_version = 0;
789     context->avrcp_cid = connection->avrcp_cid;
790     connection->browsing_l2cap_psm = 0;
791     connection->state = AVCTP_CONNECTION_W4_SDP_QUERY_COMPLETE;
792     sdp_query_context = context;
793     sdp_client_query_uuid16(&avrcp_handle_sdp_client_query_result, connection->remote_addr, BLUETOOTH_PROTOCOL_AVCTP);
794     return ERROR_CODE_SUCCESS;
795 }
796 
797 void avrcp_init(void){
798     connections = NULL;
799     if (l2cap_service_registered) return;
800 
801     int status = l2cap_register_service(&avrcp_packet_handler, BLUETOOTH_PSM_AVCTP, 0xffff, LEVEL_2);
802     if (status != ERROR_CODE_SUCCESS) return;
803     l2cap_service_registered = 1;
804 }
805 
806 void avrcp_register_controller_packet_handler(btstack_packet_handler_t callback){
807     avrcp_controller_packet_handler = callback;
808 }
809 
810 void avrcp_register_target_packet_handler(btstack_packet_handler_t callback){
811     avrcp_target_packet_handler = callback;
812 }
813 
814