xref: /btstack/src/classic/avrcp.c (revision 1b2596b5303dd8caeea8565532c93cca8dab8cc4)
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 <stdio.h>
42 #include <stdlib.h>
43 #include <string.h>
44 
45 #include "btstack.h"
46 #include "classic/avrcp.h"
47 #include "classic/avrcp_controller.h"
48 
49 #define PSM_AVCTP                       BLUETOOTH_PROTOCOL_AVCTP
50 #define PSM_AVCTP_BROWSING              0x001b
51 
52 /*
53 Category 1: Player/Recorder
54 Category 2: Monitor/Amplifier
55 Category 3: Tuner
56 Category 4: Menu
57 */
58 
59 /* controller supported features
60 Bit 0 = Category 1
61 Bit 1 = Category 2
62 Bit 2 = Category 3
63 Bit 3 = Category 4
64 Bit 4-5 = RFA
65 Bit 6 = Supports browsing
66 Bit 7-15 = RFA
67 The bits for supported categories are set to 1. Others are set to 0.
68 */
69 
70 /* target supported features
71 Bit 0 = Category 1
72 Bit 1 = Category 2
73 Bit 2 = Category 3
74 Bit 3 = Category 4
75 Bit 4 = Player Application Settings. Bit 0 should be set for this bit to be set.
76 Bit 5 = Group Navigation. Bit 0 should be set for this bit to be set.
77 Bit 6 = Supports browsing*4
78 Bit 7 = Supports multiple media player applications
79 Bit 8-15 = RFA
80 The bits for supported categories are set to 1. Others are set to 0.
81 */
82 
83 static const char * default_avrcp_controller_service_name = "BTstack AVRCP Controller Service";
84 static const char * default_avrcp_controller_service_provider_name = "BTstack AVRCP Controller Service Provider";
85 static const char * default_avrcp_target_service_name = "BTstack AVRCP Target Service";
86 static const char * default_avrcp_target_service_provider_name = "BTstack AVRCP Target Service Provider";
87 
88 static uint16_t  avrcp_cid_counter = 0;
89 
90 static avrcp_context_t * sdp_query_context;
91 static int record_id = -1;
92 static uint8_t   attribute_value[1000];
93 static const unsigned int attribute_value_buffer_size = sizeof(attribute_value);
94 
95 static void avrcp_handle_sdp_client_query_result(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
96 
97 static const char * avrcp_subunit_type_name[] = {
98     "MONITOR", "AUDIO", "PRINTER", "DISC", "TAPE_RECORDER_PLAYER", "TUNER",
99     "CA", "CAMERA", "RESERVED", "PANEL", "BULLETIN_BOARD", "CAMERA_STORAGE",
100     "VENDOR_UNIQUE", "RESERVED_FOR_ALL_SUBUNIT_TYPES",
101     "EXTENDED_TO_NEXT_BYTE", "UNIT", "ERROR"
102 };
103 
104 const char * avrcp_subunit2str(uint16_t index){
105     if (index <= 11) return avrcp_subunit_type_name[index];
106     if (index >= 0x1C && index <= 0x1F) return avrcp_subunit_type_name[index - 0x10];
107     return avrcp_subunit_type_name[16];
108 }
109 
110 static const char * avrcp_event_name[] = {
111     "ERROR", "PLAYBACK_STATUS_CHANGED",
112     "TRACK_CHANGED", "TRACK_REACHED_END", "TRACK_REACHED_START",
113     "PLAYBACK_POS_CHANGED", "BATT_STATUS_CHANGED", "SYSTEM_STATUS_CHANGED",
114     "PLAYER_APPLICATION_SETTING_CHANGED", "NOW_PLAYING_CONTENT_CHANGED",
115     "AVAILABLE_PLAYERS_CHANGED", "ADDRESSED_PLAYER_CHANGED", "UIDS_CHANGED", "VOLUME_CHANGED"
116 };
117 const char * avrcp_event2str(uint16_t index){
118     if (index <= 0x0d) return avrcp_event_name[index];
119     return avrcp_event_name[0];
120 }
121 
122 static const char * avrcp_operation_name[] = {
123     "NOT SUPPORTED", // 0x3B
124     "SKIP", "NOT SUPPORTED", "NOT SUPPORTED", "NOT SUPPORTED", "NOT SUPPORTED",
125     "VOLUME_UP", "VOLUME_DOWN", "MUTE", "PLAY", "STOP", "PAUSE", "NOT SUPPORTED",
126     "REWIND", "FAST_FORWARD", "NOT SUPPORTED", "FORWARD", "BACKWARD" // 0x4C
127 };
128 const char * avrcp_operation2str(uint8_t index){
129     if (index >= 0x3B && index <= 0x4C) return avrcp_operation_name[index - 0x3B];
130     return avrcp_operation_name[0];
131 }
132 
133 static const char * avrcp_media_attribute_id_name[] = {
134     "NONE", "TITLE", "ARTIST", "ALBUM", "TRACK", "TOTAL TRACKS", "GENRE", "SONG LENGTH"
135 };
136 const char * avrcp_attribute2str(uint8_t index){
137     if (index >= 1 && index <= 7) return avrcp_media_attribute_id_name[index];
138     return avrcp_media_attribute_id_name[0];
139 }
140 
141 static const char * avrcp_play_status_name[] = {
142     "STOPPED", "PLAYING", "PAUSED", "FORWARD SEEK", "REVERSE SEEK",
143     "ERROR" // 0xFF
144 };
145 const char * avrcp_play_status2str(uint8_t index){
146     if (index >= 1 && index <= 4) return avrcp_play_status_name[index];
147     return avrcp_play_status_name[5];
148 }
149 
150 static const char * avrcp_ctype_name[] = {
151     "CONTROL",
152     "STATUS",
153     "SPECIFIC_INQUIRY",
154     "NOTIFY",
155     "GENERAL_INQUIRY",
156     "RESERVED5",
157     "RESERVED6",
158     "RESERVED7",
159     "NOT IMPLEMENTED IN REMOTE",
160     "ACCEPTED BY REMOTE",
161     "REJECTED BY REMOTE",
162     "IN_TRANSITION",
163     "IMPLEMENTED_STABLE",
164     "CHANGED_STABLE",
165     "RESERVED",
166     "INTERIM"
167 };
168 const char * avrcp_ctype2str(uint8_t index){
169     if (index < sizeof(avrcp_ctype_name)){
170         return avrcp_ctype_name[index];
171     }
172     return "NONE";
173 }
174 
175 static const char * avrcp_shuffle_mode_name[] = {
176     "SHUFFLE OFF",
177     "SHUFFLE ALL TRACKS",
178     "SHUFFLE GROUP"
179 };
180 
181 const char * avrcp_shuffle2str(uint8_t index){
182     if (index >= 1 && index <= 3) return avrcp_shuffle_mode_name[index-1];
183     return "NONE";
184 }
185 
186 static const char * avrcp_repeat_mode_name[] = {
187     "REPEAT OFF",
188     "REPEAT SINGLE TRACK",
189     "REPEAT ALL TRACKS",
190     "REPEAT GROUP"
191 };
192 
193 const char * avrcp_repeat2str(uint8_t index){
194     if (index >= 1 && index <= 4) return avrcp_repeat_mode_name[index-1];
195     return "NONE";
196 }
197 
198 void avrcp_create_sdp_record(uint8_t controller, uint8_t * service, uint32_t service_record_handle, uint8_t browsing, uint16_t supported_features, const char * service_name, const char * service_provider_name){
199     uint8_t* attribute;
200     de_create_sequence(service);
201 
202     // 0x0000 "Service Record Handle"
203     de_add_number(service, DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_SERVICE_RECORD_HANDLE);
204     de_add_number(service, DE_UINT, DE_SIZE_32, service_record_handle);
205 
206     // 0x0001 "Service Class ID List"
207     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_SERVICE_CLASS_ID_LIST);
208     attribute = de_push_sequence(service);
209     {
210         if (controller){
211             de_add_number(attribute, DE_UUID, DE_SIZE_16, BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL);
212             de_add_number(attribute, DE_UUID, DE_SIZE_16, BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL_CONTROLLER);
213         } else {
214             de_add_number(attribute, DE_UUID, DE_SIZE_16, BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL_TARGET);
215         }
216     }
217     de_pop_sequence(service, attribute);
218 
219     // 0x0004 "Protocol Descriptor List"
220     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_PROTOCOL_DESCRIPTOR_LIST);
221     attribute = de_push_sequence(service);
222     {
223         uint8_t* l2cpProtocol = de_push_sequence(attribute);
224         {
225             de_add_number(l2cpProtocol,  DE_UUID, DE_SIZE_16, BLUETOOTH_PROTOCOL_L2CAP);
226             de_add_number(l2cpProtocol,  DE_UINT, DE_SIZE_16, BLUETOOTH_PROTOCOL_AVCTP);
227         }
228         de_pop_sequence(attribute, l2cpProtocol);
229 
230         uint8_t* avctpProtocol = de_push_sequence(attribute);
231         {
232             de_add_number(avctpProtocol,  DE_UUID, DE_SIZE_16, BLUETOOTH_PROTOCOL_AVCTP);  // avctpProtocol_service
233             de_add_number(avctpProtocol,  DE_UINT, DE_SIZE_16,  0x0103);    // version
234         }
235         de_pop_sequence(attribute, avctpProtocol);
236     }
237     de_pop_sequence(service, attribute);
238 
239     // 0x0005 "Public Browse Group"
240     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_BROWSE_GROUP_LIST); // public browse group
241     attribute = de_push_sequence(service);
242     {
243         de_add_number(attribute,  DE_UUID, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_PUBLIC_BROWSE_ROOT);
244     }
245     de_pop_sequence(service, attribute);
246 
247     // 0x0009 "Bluetooth Profile Descriptor List"
248     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_BLUETOOTH_PROFILE_DESCRIPTOR_LIST);
249     attribute = de_push_sequence(service);
250     {
251         uint8_t *avrcProfile = de_push_sequence(attribute);
252         {
253             de_add_number(avrcProfile,  DE_UUID, DE_SIZE_16, BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL);
254             de_add_number(avrcProfile,  DE_UINT, DE_SIZE_16, 0x0105);
255         }
256         de_pop_sequence(attribute, avrcProfile);
257     }
258     de_pop_sequence(service, attribute);
259 
260     // 0x000d "Additional Bluetooth Profile Descriptor List"
261     if (browsing){
262         de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_ADDITIONAL_PROTOCOL_DESCRIPTOR_LISTS);
263         attribute = de_push_sequence(service);
264         {
265             uint8_t * des = de_push_sequence(attribute);
266             {
267                 uint8_t* browsing_l2cpProtocol = de_push_sequence(des);
268                 {
269                     de_add_number(browsing_l2cpProtocol,  DE_UUID, DE_SIZE_16, BLUETOOTH_PROTOCOL_L2CAP);
270                     de_add_number(browsing_l2cpProtocol,  DE_UINT, DE_SIZE_16, PSM_AVCTP_BROWSING);
271                 }
272                 de_pop_sequence(des, browsing_l2cpProtocol);
273 
274                 uint8_t* browsing_avctpProtocol = de_push_sequence(des);
275                 {
276                     de_add_number(browsing_avctpProtocol,  DE_UUID, DE_SIZE_16, BLUETOOTH_PROTOCOL_AVCTP);  // browsing_avctpProtocol_service
277                     de_add_number(browsing_avctpProtocol,  DE_UINT, DE_SIZE_16,  0x0103);    // version
278                 }
279                 de_pop_sequence(des, browsing_avctpProtocol);
280             }
281             de_pop_sequence(attribute, des);
282         }
283         de_pop_sequence(service, attribute);
284     }
285 
286 
287     // 0x0100 "Service Name"
288     de_add_number(service,  DE_UINT, DE_SIZE_16, 0x0100);
289     if (service_name){
290         de_add_data(service,  DE_STRING, strlen(service_name), (uint8_t *) service_name);
291     } else {
292         if (controller){
293             de_add_data(service,  DE_STRING, strlen(default_avrcp_controller_service_name), (uint8_t *) default_avrcp_controller_service_name);
294         } else {
295             de_add_data(service,  DE_STRING, strlen(default_avrcp_target_service_name), (uint8_t *) default_avrcp_target_service_name);
296         }
297     }
298 
299     // 0x0100 "Provider Name"
300     de_add_number(service,  DE_UINT, DE_SIZE_16, 0x0102);
301     if (service_provider_name){
302         de_add_data(service,  DE_STRING, strlen(service_provider_name), (uint8_t *) service_provider_name);
303     } else {
304         if (controller){
305             de_add_data(service,  DE_STRING, strlen(default_avrcp_controller_service_provider_name), (uint8_t *) default_avrcp_controller_service_provider_name);
306         } else {
307             de_add_data(service,  DE_STRING, strlen(default_avrcp_target_service_provider_name), (uint8_t *) default_avrcp_target_service_provider_name);
308         }
309     }
310 
311     // 0x0311 "Supported Features"
312     de_add_number(service, DE_UINT, DE_SIZE_16, 0x0311);
313     de_add_number(service, DE_UINT, DE_SIZE_16, supported_features);
314 }
315 
316 static avrcp_connection_t * get_avrcp_connection_for_bd_addr(bd_addr_t addr, avrcp_context_t * context){
317     btstack_linked_list_iterator_t it;
318     btstack_linked_list_iterator_init(&it, (btstack_linked_list_t *) &context->connections);
319     while (btstack_linked_list_iterator_has_next(&it)){
320         avrcp_connection_t * connection = (avrcp_connection_t *)btstack_linked_list_iterator_next(&it);
321         if (memcmp(addr, connection->remote_addr, 6) != 0) continue;
322         return connection;
323     }
324     return NULL;
325 }
326 
327 avrcp_connection_t * get_avrcp_connection_for_l2cap_signaling_cid(uint16_t l2cap_cid, avrcp_context_t * context){
328     btstack_linked_list_iterator_t it;
329     btstack_linked_list_iterator_init(&it, (btstack_linked_list_t *)  &context->connections);
330     while (btstack_linked_list_iterator_has_next(&it)){
331         avrcp_connection_t * connection = (avrcp_connection_t *)btstack_linked_list_iterator_next(&it);
332         if (connection->l2cap_signaling_cid != l2cap_cid) continue;
333         return connection;
334     }
335     return NULL;
336 }
337 
338 avrcp_connection_t * get_avrcp_connection_for_avrcp_cid(uint16_t avrcp_cid, avrcp_context_t * context){
339     btstack_linked_list_iterator_t it;
340     btstack_linked_list_iterator_init(&it, (btstack_linked_list_t *)  &context->connections);
341     while (btstack_linked_list_iterator_has_next(&it)){
342         avrcp_connection_t * connection = (avrcp_connection_t *)btstack_linked_list_iterator_next(&it);
343         if (connection->avrcp_cid != avrcp_cid) continue;
344         return connection;
345     }
346     return NULL;
347 }
348 
349 void avrcp_request_can_send_now(avrcp_connection_t * connection, uint16_t l2cap_cid){
350     connection->wait_to_send = 1;
351     l2cap_request_can_send_now_event(l2cap_cid);
352 }
353 
354 
355 static uint16_t avdtp_get_next_avrcp_cid(void){
356     avrcp_cid_counter++;
357     if (avrcp_cid_counter == 0){
358         avrcp_cid_counter = 1;
359     }
360     return avrcp_cid_counter;
361 }
362 
363 static avrcp_connection_t * avrcp_create_connection(bd_addr_t remote_addr, avrcp_context_t * context){
364     avrcp_connection_t * connection = btstack_memory_avrcp_connection_get();
365     memset(connection, 0, sizeof(avrcp_connection_t));
366     connection->state = AVCTP_CONNECTION_IDLE;
367     connection->transaction_label = 0xFF;
368     connection->avrcp_cid = avdtp_get_next_avrcp_cid();
369     memcpy(connection->remote_addr, remote_addr, 6);
370     btstack_linked_list_add(&context->connections, (btstack_linked_item_t *) connection);
371     return connection;
372 }
373 
374 
375 void avrcp_emit_connection_established(btstack_packet_handler_t callback, uint16_t avrcp_cid, bd_addr_t addr, uint8_t status){
376     if (!callback) return;
377     uint8_t event[12];
378     int pos = 0;
379     event[pos++] = HCI_EVENT_AVRCP_META;
380     event[pos++] = sizeof(event) - 2;
381     event[pos++] = AVRCP_SUBEVENT_CONNECTION_ESTABLISHED;
382     event[pos++] = status;
383     reverse_bd_addr(addr,&event[pos]);
384     pos += 6;
385     little_endian_store_16(event, pos, avrcp_cid);
386     pos += 2;
387     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
388 }
389 
390 void avrcp_emit_connection_closed(btstack_packet_handler_t callback, uint16_t avrcp_cid){
391     if (!callback) return;
392     uint8_t event[5];
393     int pos = 0;
394     event[pos++] = HCI_EVENT_AVRCP_META;
395     event[pos++] = sizeof(event) - 2;
396     event[pos++] = AVRCP_SUBEVENT_CONNECTION_RELEASED;
397     little_endian_store_16(event, pos, avrcp_cid);
398     pos += 2;
399     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
400 }
401 
402 static void avrcp_handle_sdp_client_query_result(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
403     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(sdp_query_context->avrcp_cid, sdp_query_context);
404     if (!connection) return;
405     if (connection->state != AVCTP_SIGNALING_W4_SDP_QUERY_COMPLETE) return;
406     UNUSED(packet_type);
407     UNUSED(channel);
408     UNUSED(size);
409 
410     des_iterator_t des_list_it;
411     des_iterator_t prot_it;
412     // uint32_t avdtp_remote_uuid    = 0;
413 
414     switch (hci_event_packet_get_type(packet)){
415         case SDP_EVENT_QUERY_ATTRIBUTE_VALUE:
416             // Handle new SDP record
417             if (sdp_event_query_attribute_byte_get_record_id(packet) != record_id) {
418                 record_id = sdp_event_query_attribute_byte_get_record_id(packet);
419                 // log_info("SDP Record: Nr: %d", record_id);
420             }
421 
422             if (sdp_event_query_attribute_byte_get_attribute_length(packet) <= attribute_value_buffer_size) {
423                 attribute_value[sdp_event_query_attribute_byte_get_data_offset(packet)] = sdp_event_query_attribute_byte_get_data(packet);
424 
425                 if ((uint16_t)(sdp_event_query_attribute_byte_get_data_offset(packet)+1) == sdp_event_query_attribute_byte_get_attribute_length(packet)) {
426                     switch(sdp_event_query_attribute_byte_get_attribute_id(packet)) {
427                         case BLUETOOTH_ATTRIBUTE_SERVICE_CLASS_ID_LIST:
428                             if (de_get_element_type(attribute_value) != DE_DES) break;
429                             for (des_iterator_init(&des_list_it, attribute_value); des_iterator_has_more(&des_list_it); des_iterator_next(&des_list_it)) {
430                                 uint8_t * element = des_iterator_get_element(&des_list_it);
431                                 if (de_get_element_type(element) != DE_UUID) continue;
432                                 uint32_t uuid = de_get_uuid32(element);
433                                 switch (uuid){
434                                     case BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL_TARGET:
435                                         if (sdp_query_context->role == AVRCP_CONTROLLER) {
436                                             sdp_query_context->role_supported = 1;
437                                             break;
438                                         }
439                                         break;
440                                     case BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL:
441                                     case BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL_CONTROLLER:
442                                         if (sdp_query_context->role == AVRCP_TARGET) {
443                                             sdp_query_context->role_supported = 1;
444                                             break;
445                                         }
446                                         break;
447                                     default:
448                                         break;
449                                 }
450                             }
451                             break;
452 
453                         case BLUETOOTH_ATTRIBUTE_PROTOCOL_DESCRIPTOR_LIST: {
454                                 // log_info("SDP Attribute: 0x%04x", sdp_event_query_attribute_byte_get_attribute_id(packet));
455                                 for (des_iterator_init(&des_list_it, attribute_value); des_iterator_has_more(&des_list_it); des_iterator_next(&des_list_it)) {
456                                     uint8_t       *des_element;
457                                     uint8_t       *element;
458                                     uint32_t       uuid;
459 
460                                     if (des_iterator_get_type(&des_list_it) != DE_DES) continue;
461 
462                                     des_element = des_iterator_get_element(&des_list_it);
463                                     des_iterator_init(&prot_it, des_element);
464                                     element = des_iterator_get_element(&prot_it);
465 
466                                     if (de_get_element_type(element) != DE_UUID) continue;
467 
468                                     uuid = de_get_uuid32(element);
469                                     switch (uuid){
470                                         case BLUETOOTH_PROTOCOL_L2CAP:
471                                             if (!des_iterator_has_more(&prot_it)) continue;
472                                             des_iterator_next(&prot_it);
473                                             de_element_get_uint16(des_iterator_get_element(&prot_it), &sdp_query_context->avrcp_l2cap_psm);
474                                             break;
475                                         case BLUETOOTH_PROTOCOL_AVCTP:
476                                             if (!des_iterator_has_more(&prot_it)) continue;
477                                             des_iterator_next(&prot_it);
478                                             de_element_get_uint16(des_iterator_get_element(&prot_it), &sdp_query_context->avrcp_version);
479                                             break;
480                                         default:
481                                             break;
482                                     }
483                                 }
484                             }
485                             break;
486                         case BLUETOOTH_ATTRIBUTE_ADDITIONAL_PROTOCOL_DESCRIPTOR_LISTS: {
487                                 // log_info("SDP Attribute: 0x%04x", sdp_event_query_attribute_byte_get_attribute_id(packet));
488                                 if (de_get_element_type(attribute_value) != DE_DES) break;
489 
490                                 des_iterator_t des_list_0_it;
491                                 uint8_t       *element_0;
492 
493                                 des_iterator_init(&des_list_0_it, attribute_value);
494                                 element_0 = des_iterator_get_element(&des_list_0_it);
495 
496                                 for (des_iterator_init(&des_list_it, element_0); des_iterator_has_more(&des_list_it); des_iterator_next(&des_list_it)) {
497                                     uint8_t       *des_element;
498                                     uint8_t       *element;
499                                     uint32_t       uuid;
500 
501                                     if (des_iterator_get_type(&des_list_it) != DE_DES) continue;
502 
503                                     des_element = des_iterator_get_element(&des_list_it);
504                                     des_iterator_init(&prot_it, des_element);
505                                     element = des_iterator_get_element(&prot_it);
506 
507                                     if (de_get_element_type(element) != DE_UUID) continue;
508 
509                                     uuid = de_get_uuid32(element);
510                                     switch (uuid){
511                                         case BLUETOOTH_PROTOCOL_L2CAP:
512                                             if (!des_iterator_has_more(&prot_it)) continue;
513                                             des_iterator_next(&prot_it);
514                                             de_element_get_uint16(des_iterator_get_element(&prot_it), &sdp_query_context->avrcp_browsing_l2cap_psm);
515                                             break;
516                                         case BLUETOOTH_PROTOCOL_AVCTP:
517                                             if (!des_iterator_has_more(&prot_it)) continue;
518                                             des_iterator_next(&prot_it);
519                                             de_element_get_uint16(des_iterator_get_element(&prot_it), &sdp_query_context->avrcp_browsing_version);
520                                             break;
521                                         default:
522                                             break;
523                                     }
524                                 }
525                             }
526                             break;
527                         default:
528                             break;
529                     }
530                 }
531             } else {
532                 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));
533             }
534             break;
535 
536         case SDP_EVENT_QUERY_COMPLETE:
537             log_info("General query done with status %d, role supported %d.\n", sdp_event_query_complete_get_status(packet), sdp_query_context->role_supported);
538             if (!sdp_query_context->role_supported || !sdp_query_context->avrcp_l2cap_psm){
539                 connection->state = AVCTP_CONNECTION_IDLE;
540                 avrcp_emit_connection_established(sdp_query_context->avrcp_callback, connection->avrcp_cid, connection->remote_addr, SDP_SERVICE_NOT_FOUND);
541                 break;
542             }
543             log_info("AVRCP Control PSM 0x%02x, Browsing PSM 0x%02x", sdp_query_context->avrcp_l2cap_psm, sdp_query_context->avrcp_browsing_l2cap_psm);
544             connection->state = AVCTP_CONNECTION_W4_L2CAP_CONNECTED;
545             l2cap_create_channel(sdp_query_context->packet_handler, connection->remote_addr, sdp_query_context->avrcp_l2cap_psm, l2cap_max_mtu(), NULL);
546             break;
547     }
548 }
549 
550 void avrcp_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size, avrcp_context_t * context){
551     UNUSED(channel);
552     UNUSED(size);
553     bd_addr_t event_addr;
554     uint16_t local_cid;
555     uint8_t  status;
556     avrcp_connection_t * connection = NULL;
557 
558     if (packet_type != HCI_EVENT_PACKET) return;
559 
560     switch (hci_event_packet_get_type(packet)) {
561         case HCI_EVENT_DISCONNECTION_COMPLETE:
562             // connection closed -> quit test app
563             // status = hci_event_disconnection_complete_get_status(packet);
564             avrcp_emit_connection_closed(context->avrcp_callback, 0);
565             break;
566         case L2CAP_EVENT_INCOMING_CONNECTION:
567             l2cap_event_incoming_connection_get_address(packet, event_addr);
568             local_cid = l2cap_event_incoming_connection_get_local_cid(packet);
569             connection = avrcp_create_connection(event_addr, context);
570             if (!connection) {
571                 log_error("Failed to alloc connection structure");
572                 l2cap_decline_connection(local_cid);
573                 break;
574             }
575             connection->state = AVCTP_CONNECTION_W4_L2CAP_CONNECTED;
576             connection->l2cap_signaling_cid = local_cid;
577             log_info("L2CAP_EVENT_INCOMING_CONNECTION avrcp_cid 0x%02x, l2cap_signaling_cid 0x%02x", connection->avrcp_cid, connection->l2cap_signaling_cid);
578             l2cap_accept_connection(local_cid);
579             break;
580 
581         case L2CAP_EVENT_CHANNEL_OPENED:
582             l2cap_event_channel_opened_get_address(packet, event_addr);
583             status = l2cap_event_channel_opened_get_status(packet);
584             local_cid = l2cap_event_channel_opened_get_local_cid(packet);
585 
586             connection = get_avrcp_connection_for_bd_addr(event_addr, context);
587             if (!connection){
588                 log_error("Failed to alloc AVRCP connection structure");
589                 avrcp_emit_connection_established(context->avrcp_callback, connection->avrcp_cid, event_addr, BTSTACK_MEMORY_ALLOC_FAILED);
590                 l2cap_disconnect(local_cid, 0); // reason isn't used
591                 break;
592             }
593             if (status != ERROR_CODE_SUCCESS){
594                 log_info("L2CAP connection to connection %s failed. status code 0x%02x", bd_addr_to_str(event_addr), status);
595                 avrcp_emit_connection_established(context->avrcp_callback, connection->avrcp_cid, event_addr, status);
596                 btstack_linked_list_remove(&context->connections, (btstack_linked_item_t*) connection);
597                 btstack_memory_avrcp_connection_free(connection);
598                 break;
599             }
600             connection->l2cap_signaling_cid = local_cid;
601             log_info("L2CAP_EVENT_CHANNEL_OPENED avrcp_cid 0x%02x, l2cap_signaling_cid 0x%02x", connection->avrcp_cid, connection->l2cap_signaling_cid);
602             connection->state = AVCTP_CONNECTION_OPENED;
603             avrcp_emit_connection_established(context->avrcp_callback, connection->avrcp_cid, event_addr, ERROR_CODE_SUCCESS);
604             break;
605 
606         case L2CAP_EVENT_CHANNEL_CLOSED:
607             // data: event (8), len(8), channel (16)
608             local_cid = l2cap_event_channel_closed_get_local_cid(packet);
609             connection = get_avrcp_connection_for_l2cap_signaling_cid(local_cid, context);
610             if (connection){
611                 avrcp_emit_connection_closed(context->avrcp_callback, connection->avrcp_cid);
612                 // free connection
613                 btstack_linked_list_remove(&context->connections, (btstack_linked_item_t*) connection);
614                 btstack_memory_avrcp_connection_free(connection);
615                 break;
616             }
617             break;
618         default:
619             break;
620     }
621 }
622 
623 uint8_t avrcp_connect(bd_addr_t bd_addr, avrcp_context_t * context, uint16_t * avrcp_cid){
624     avrcp_connection_t * connection = get_avrcp_connection_for_bd_addr(bd_addr, context);
625     if (connection){
626         return ERROR_CODE_COMMAND_DISALLOWED;
627     }
628     connection = avrcp_create_connection(bd_addr, context);
629     if (!connection){
630         log_error("avrcp: could not allocate connection struct.");
631         return BTSTACK_MEMORY_ALLOC_FAILED;
632     }
633 
634     if (!avrcp_cid) return L2CAP_LOCAL_CID_DOES_NOT_EXIST;
635 
636     *avrcp_cid = connection->avrcp_cid;
637     connection->state = AVCTP_SIGNALING_W4_SDP_QUERY_COMPLETE;
638 
639     context->avrcp_l2cap_psm = 0;
640     context->avrcp_version = 0;
641     context->avrcp_cid = connection->avrcp_cid;
642 
643     sdp_query_context = context;
644 
645     sdp_client_query_uuid16(&avrcp_handle_sdp_client_query_result, bd_addr, BLUETOOTH_PROTOCOL_AVCTP);
646     return ERROR_CODE_SUCCESS;
647 }
648