xref: /btstack/src/classic/avrcp_controller.c (revision 5d3671d9fbdbeab06c6014bb834d9a2cf92c0117)
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_controller.c"
39 
40 #include <stdint.h>
41 #include <string.h>
42 #include <inttypes.h>
43 
44 #include "classic/avrcp.h"
45 #include "classic/avrcp_controller.h"
46 
47 #include "bluetooth_sdp.h"
48 #include "btstack_debug.h"
49 #include "btstack_event.h"
50 #include "btstack_util.h"
51 #include "l2cap.h"
52 
53 #define AVRCP_MAX_AV_C_MESSAGE_FRAME_SIZE 512
54 
55 // made public in avrcp_controller.h
56 avrcp_context_t avrcp_controller_context;
57 
58 static uint8_t avrcp_controller_calc_next_transaction_label(uint8_t current_transaction_label){
59     current_transaction_label++;
60     if (current_transaction_label == 16){
61         current_transaction_label = 1;
62     }
63     return current_transaction_label;
64 }
65 
66 static uint8_t avrcp_controller_get_next_transaction_label(avrcp_connection_t * connection){
67     connection->transaction_id_counter = avrcp_controller_calc_next_transaction_label(connection->transaction_id_counter);
68     return connection->transaction_id_counter;
69 }
70 
71 static bool avrcp_controller_is_transaction_id_valid(avrcp_connection_t * connection, uint8_t transaction_id){
72     uint8_t delta = ((int8_t) transaction_id - connection->last_confirmed_transaction_id) & 0x0f;
73     return delta < 15;
74 }
75 
76 static uint16_t avrcp_get_max_payload_size_for_avctp_packet_type(avrcp_connection_t * connection, avctp_packet_type_t avctp_packet_type){
77     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);
78 
79     switch (avctp_packet_type){
80         case AVCTP_SINGLE_PACKET:
81             return max_frame_size - 3;
82         case AVCTP_START_PACKET:
83             return max_frame_size - 4;
84         case AVCTP_CONTINUE_PACKET:
85         case AVCTP_END_PACKET:
86             return max_frame_size - 1;
87         default:
88             btstack_assert(false);
89             return 0;
90     }
91 }
92 
93 
94 static void avrcp_custome_command_data_init(avrcp_connection_t * connection,
95     avrcp_command_opcode_t opcode, avrcp_command_type_t command_type,
96     avrcp_subunit_type_t subunit_type, avrcp_subunit_id_t subunit_id,
97     avrcp_pdu_id_t pdu_id, uint32_t company_id){
98 
99     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
100     connection->command_opcode = opcode;
101     connection->command_type = command_type;
102     connection->subunit_type = subunit_type;
103     connection->subunit_id = subunit_id;
104     connection->company_id = company_id << 16;
105     connection->pdu_id = pdu_id;
106     connection->data = NULL;
107     connection->data_offset = 0;
108     connection->data_len = 0;
109 }
110 
111 static void avrcp_vendor_dependent_command_data_init(avrcp_connection_t * connection, avrcp_command_type_t command_type, avrcp_pdu_id_t pdu_id){
112     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
113     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
114     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
115     connection->subunit_id = AVRCP_SUBUNIT_ID;
116     connection->company_id = BT_SIG_COMPANY_ID;
117 
118     connection->command_type = command_type;
119     connection->pdu_id = pdu_id;
120     connection->data = connection->cmd_operands;
121     connection->data_offset = 0;
122     connection->data_len = 0;
123 }
124 
125 static void avrcp_pass_through_command_data_init(avrcp_connection_t * connection, avrcp_operation_id_t opid){
126     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
127     connection->command_opcode =  AVRCP_CMD_OPCODE_PASS_THROUGH;
128     connection->command_type = AVRCP_CTYPE_CONTROL;
129     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
130     connection->subunit_id =   AVRCP_SUBUNIT_ID;
131 
132     connection->company_id = 0;
133     connection->pdu_id = 0;
134     connection->operation_id = opid;
135 
136     connection->data = connection->cmd_operands;
137     connection->data_offset = 0;
138     connection->data_len = 0;
139 }
140 static int avrcp_controller_supports_browsing(uint16_t controller_supported_features){
141     return controller_supported_features & AVRCP_FEATURE_MASK_BROWSING;
142 }
143 
144 static void avrcp_controller_emit_notification_complete(avrcp_connection_t * connection, uint8_t status, uint8_t event_id, bool enabled){
145     uint8_t event[8];
146     uint8_t pos = 0;
147     event[pos++] = HCI_EVENT_AVRCP_META;
148     event[pos++] = sizeof(event) - 2;
149     event[pos++] = AVRCP_SUBEVENT_NOTIFICATION_STATE;
150     little_endian_store_16(event, pos, connection->avrcp_cid);
151     pos += 2;
152     event[pos++] = status;
153     event[pos++] = enabled ? 1 : 0;
154     event[pos++] = event_id;
155     UNUSED(pos);
156     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
157 }
158 
159 static void avrcp_controller_emit_supported_events(avrcp_connection_t * connection){
160     uint8_t ctype = (uint8_t) AVRCP_CTYPE_RESPONSE_CHANGED_STABLE;
161     uint8_t event_id;
162 
163     for (event_id = (uint8_t) AVRCP_NOTIFICATION_EVENT_FIRST_INDEX; event_id < (uint8_t) AVRCP_NOTIFICATION_EVENT_LAST_INDEX; event_id++){
164         if ( (connection->target_supported_notifications & (1<<event_id)) == 0){
165             continue;
166         }
167         uint8_t event[8];
168         uint8_t pos = 0;
169         event[pos++] = HCI_EVENT_AVRCP_META;
170         event[pos++] = sizeof(event) - 2;
171         event[pos++] = AVRCP_SUBEVENT_GET_CAPABILITY_EVENT_ID;
172         little_endian_store_16(event, pos, connection->avrcp_cid);
173         pos += 2;
174         event[pos++] = ctype;
175         event[pos++] = 0;
176         event[pos++] = event_id;
177         UNUSED(pos);
178         (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
179     }
180 
181     uint8_t event[7];
182     uint8_t pos = 0;
183     event[pos++] = HCI_EVENT_AVRCP_META;
184     event[pos++] = sizeof(event) - 2;
185     event[pos++] = AVRCP_SUBEVENT_GET_CAPABILITY_EVENT_ID_DONE;
186     little_endian_store_16(event, pos, connection->avrcp_cid);
187     pos += 2;
188     event[pos++] = ctype;
189     event[pos++] = 0;
190     UNUSED(pos);
191     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
192 }
193 
194 static void avrcp_controller_emit_notification_for_event_id(uint16_t avrcp_cid, avrcp_notification_event_id_t event_id,
195                                                             avrcp_command_type_t ctype, const uint8_t *payload,
196                                                             uint16_t size) {
197     switch (event_id){
198         case AVRCP_NOTIFICATION_EVENT_PLAYBACK_POS_CHANGED:{
199             if (size < 4) break;
200             uint32_t song_position = big_endian_read_32(payload, 0);
201             uint16_t offset = 0;
202             uint8_t event[10];
203             event[offset++] = HCI_EVENT_AVRCP_META;
204             event[offset++] = sizeof(event) - 2;
205             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_PLAYBACK_POS_CHANGED;
206             little_endian_store_16(event, offset, avrcp_cid);
207             offset += 2;
208             event[offset++] = ctype;
209             little_endian_store_32(event, offset, song_position);
210             offset += 4;
211             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
212             break;
213         }
214         case AVRCP_NOTIFICATION_EVENT_PLAYBACK_STATUS_CHANGED:{
215             if (size < 1) break;
216             uint16_t offset = 0;
217             uint8_t event[7];
218             event[offset++] = HCI_EVENT_AVRCP_META;
219             event[offset++] = sizeof(event) - 2;
220             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_PLAYBACK_STATUS_CHANGED;
221             little_endian_store_16(event, offset, avrcp_cid);
222             offset += 2;
223             event[offset++] = ctype;
224             event[offset++] = payload[0];
225             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
226             break;
227         }
228         case AVRCP_NOTIFICATION_EVENT_TRACK_CHANGED:{
229             uint16_t offset = 0;
230             uint8_t event[6];
231             event[offset++] = HCI_EVENT_AVRCP_META;
232             event[offset++] = sizeof(event) - 2;
233             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_TRACK_CHANGED;
234             little_endian_store_16(event, offset, avrcp_cid);
235             offset += 2;
236             event[offset++] = ctype;
237             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
238             break;
239         }
240         case AVRCP_NOTIFICATION_EVENT_NOW_PLAYING_CONTENT_CHANGED:{
241             uint16_t offset = 0;
242             uint8_t event[6];
243             event[offset++] = HCI_EVENT_AVRCP_META;
244             event[offset++] = sizeof(event) - 2;
245             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_NOW_PLAYING_CONTENT_CHANGED;
246             little_endian_store_16(event, offset, avrcp_cid);
247             offset += 2;
248             event[offset++] = ctype;
249             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
250             break;
251         }
252         case AVRCP_NOTIFICATION_EVENT_AVAILABLE_PLAYERS_CHANGED:{
253             uint16_t offset = 0;
254             uint8_t event[6];
255             event[offset++] = HCI_EVENT_AVRCP_META;
256             event[offset++] = sizeof(event) - 2;
257             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_AVAILABLE_PLAYERS_CHANGED;
258             little_endian_store_16(event, offset, avrcp_cid);
259             offset += 2;
260             event[offset++] = ctype;
261             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
262             break;
263         }
264         case AVRCP_NOTIFICATION_EVENT_VOLUME_CHANGED:{
265             if (size < 1) break;
266             uint16_t offset = 0;
267             uint8_t event[7];
268             event[offset++] = HCI_EVENT_AVRCP_META;
269             event[offset++] = sizeof(event) - 2;
270             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_VOLUME_CHANGED;
271             little_endian_store_16(event, offset, avrcp_cid);
272             offset += 2;
273             event[offset++] = ctype;
274             event[offset++] = payload[0] & 0x7F;
275             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
276             break;
277         }
278         case AVRCP_NOTIFICATION_EVENT_UIDS_CHANGED:{
279             if (size < 2) break;
280             uint8_t event[8];
281             uint16_t offset = 0;
282             uint16_t uuid = big_endian_read_16(payload, 0);
283             event[offset++] = HCI_EVENT_AVRCP_META;
284             event[offset++] = sizeof(event) - 2;
285             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_EVENT_UIDS_CHANGED;
286             little_endian_store_16(event, offset, avrcp_cid);
287             offset += 2;
288             event[offset++] = ctype;
289             little_endian_store_16(event, offset, uuid);
290             offset += 2;
291             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
292             break;
293         }
294 
295         case AVRCP_NOTIFICATION_EVENT_TRACK_REACHED_END:{
296             uint16_t offset = 0;
297             uint8_t event[6];
298             event[offset++] = HCI_EVENT_AVRCP_META;
299             event[offset++] = sizeof(event) - 2;
300             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_EVENT_TRACK_REACHED_END;
301             little_endian_store_16(event, offset, avrcp_cid);
302             offset += 2;
303             event[offset++] = ctype;
304             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
305             break;
306         }
307         case AVRCP_NOTIFICATION_EVENT_TRACK_REACHED_START:{
308             uint16_t offset = 0;
309             uint8_t event[6];
310             event[offset++] = HCI_EVENT_AVRCP_META;
311             event[offset++] = sizeof(event) - 2;
312             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_EVENT_TRACK_REACHED_START;
313             little_endian_store_16(event, offset, avrcp_cid);
314             offset += 2;
315             event[offset++] = ctype;
316             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
317             break;
318         }
319         case AVRCP_NOTIFICATION_EVENT_BATT_STATUS_CHANGED:{
320             if (size < 1) break;
321             uint16_t offset = 0;
322             uint8_t event[7];
323             event[offset++] = HCI_EVENT_AVRCP_META;
324             event[offset++] = sizeof(event) - 2;
325             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_EVENT_BATT_STATUS_CHANGED;
326             little_endian_store_16(event, offset, avrcp_cid);
327             offset += 2;
328             event[offset++] = ctype;
329             event[offset++] = payload[0];
330             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
331             break;
332         }
333 
334         case AVRCP_NOTIFICATION_EVENT_SYSTEM_STATUS_CHANGED:{
335             if (size < 1) break;
336             uint16_t offset = 0;
337             uint8_t event[7];
338             event[offset++] = HCI_EVENT_AVRCP_META;
339             event[offset++] = sizeof(event) - 2;
340             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_EVENT_SYSTEM_STATUS_CHANGED;
341             little_endian_store_16(event, offset, avrcp_cid);
342             offset += 2;
343             event[offset++] = ctype;
344             event[offset++] = payload[0];
345             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
346             break;
347         }
348 
349         case AVRCP_NOTIFICATION_EVENT_PLAYER_APPLICATION_SETTING_CHANGED:
350         default:
351             log_info("avrcp: not implemented");
352             break;
353     }
354 }
355 
356 static void avrcp_controller_emit_repeat_and_shuffle_mode(btstack_packet_handler_t callback, uint16_t avrcp_cid, uint8_t ctype, avrcp_repeat_mode_t repeat_mode, avrcp_shuffle_mode_t shuffle_mode){
357     btstack_assert(callback != NULL);
358 
359     uint8_t event[8];
360     int pos = 0;
361     event[pos++] = HCI_EVENT_AVRCP_META;
362     event[pos++] = sizeof(event) - 2;
363     event[pos++] = AVRCP_SUBEVENT_SHUFFLE_AND_REPEAT_MODE;
364     little_endian_store_16(event, pos, avrcp_cid);
365     pos += 2;
366     event[pos++] = ctype;
367     event[pos++] = repeat_mode;
368     event[pos++] = shuffle_mode;
369     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
370 }
371 
372 static void avrcp_controller_emit_now_playing_info_event_done(btstack_packet_handler_t callback, uint16_t avrcp_cid, uint8_t ctype, uint8_t status){
373     uint8_t event[7];
374     int pos = 0;
375     event[pos++] = HCI_EVENT_AVRCP_META;
376     event[pos++] = sizeof(event) - 2;
377     event[pos++] = AVRCP_SUBEVENT_NOW_PLAYING_INFO_DONE;
378     little_endian_store_16(event, pos, avrcp_cid);
379     pos += 2;
380     event[pos++] = ctype;
381     event[pos++] = status;
382     (*callback)(HCI_EVENT_PACKET, 0, event, pos);
383 }
384 
385 static void avrcp_controller_emit_now_playing_info_event(btstack_packet_handler_t callback, uint16_t avrcp_cid, uint8_t ctype, avrcp_media_attribute_id_t attr_id, uint8_t * value, uint16_t value_len){
386     uint8_t event[HCI_EVENT_BUFFER_SIZE];
387     int pos = 0;
388     event[pos++] = HCI_EVENT_AVRCP_META;
389     // reserve one byte for subevent type and data len
390     int data_len_pos = pos;
391     pos++;
392     int subevent_type_pos = pos;
393     pos++;
394     little_endian_store_16(event, pos, avrcp_cid);
395     pos += 2;
396     event[pos++] = ctype;
397 
398     switch (attr_id){
399         case AVRCP_MEDIA_ATTR_TITLE:
400             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_TITLE_INFO;
401             event[pos++] = value_len;
402             (void)memcpy(event + pos, value, value_len);
403             break;
404         case AVRCP_MEDIA_ATTR_ARTIST:
405             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_ARTIST_INFO;
406             event[pos++] = value_len;
407             (void)memcpy(event + pos, value, value_len);
408             break;
409         case AVRCP_MEDIA_ATTR_ALBUM:
410             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_ALBUM_INFO;
411             event[pos++] = value_len;
412             (void)memcpy(event + pos, value, value_len);
413             break;
414         case AVRCP_MEDIA_ATTR_GENRE:
415             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_GENRE_INFO;
416             event[pos++] = value_len;
417             (void)memcpy(event + pos, value, value_len);
418             break;
419         case AVRCP_MEDIA_ATTR_SONG_LENGTH_MS:
420             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_SONG_LENGTH_MS_INFO;
421             if (value){
422                 little_endian_store_32(event, pos, btstack_atoi((char *)value));
423             } else {
424                 little_endian_store_32(event, pos, 0);
425             }
426             pos += 4;
427             break;
428         case AVRCP_MEDIA_ATTR_TRACK:
429             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_TRACK_INFO;
430             if (value){
431                 event[pos++] = btstack_atoi((char *)value);
432             } else {
433                 event[pos++] = 0;
434             }
435             break;
436         case AVRCP_MEDIA_ATTR_TOTAL_NUM_ITEMS:
437             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_TOTAL_TRACKS_INFO;
438             if (value){
439                 event[pos++] = btstack_atoi((char *)value);
440             } else {
441                 event[pos++] = 0;
442             }
443             break;
444         default:
445             break;
446     }
447     event[data_len_pos] = pos - 2;
448     (*callback)(HCI_EVENT_PACKET, 0, event, pos);
449 }
450 
451 static void avrcp_controller_emit_operation_status(btstack_packet_handler_t callback, uint8_t subevent, uint16_t avrcp_cid, uint8_t ctype, uint8_t operation_id){
452     btstack_assert(callback != NULL);
453 
454     uint8_t event[7];
455     int pos = 0;
456     event[pos++] = HCI_EVENT_AVRCP_META;
457     event[pos++] = sizeof(event) - 2;
458     event[pos++] = subevent;
459     little_endian_store_16(event, pos, avrcp_cid);
460     pos += 2;
461     event[pos++] = ctype;
462     event[pos++] = operation_id;
463     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
464 }
465 
466 static void avrcp_parser_reset(avrcp_connection_t * connection){
467     connection->list_offset = 0;
468     connection->num_attributes = 0;
469     connection->num_parsed_attributes = 0;
470     connection->parser_attribute_header_pos = 0;
471     connection->num_received_fragments = 0;
472     connection->parser_state = AVRCP_PARSER_GET_ATTRIBUTE_HEADER;
473 }
474 
475 static void avrcp_parser_process_byte(uint8_t byte, avrcp_connection_t * connection, avrcp_command_type_t ctype){
476     uint16_t attribute_total_value_len;
477     uint32_t attribute_id;
478     switch(connection->parser_state){
479         case AVRCP_PARSER_GET_ATTRIBUTE_HEADER:
480             connection->parser_attribute_header[connection->parser_attribute_header_pos++] = byte;
481             connection->list_offset++;
482 
483             if (connection->parser_attribute_header_pos < AVRCP_ATTRIBUTE_HEADER_LEN) return;
484 
485             attribute_total_value_len = big_endian_read_16(connection->parser_attribute_header, 6);
486             connection->attribute_value_len = btstack_min(attribute_total_value_len, AVRCP_MAX_ATTRIBUTTE_SIZE);
487             if (connection->attribute_value_len > 0){
488                 // get ready for attribute value
489                 connection->parser_state = AVRCP_PARSER_GET_ATTRIBUTE_VALUE;
490                 return;
491             }
492 
493             // emit empty attribute
494             attribute_id = big_endian_read_32(connection->parser_attribute_header, 0);
495             avrcp_controller_emit_now_playing_info_event(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, (avrcp_media_attribute_id_t) attribute_id, connection->attribute_value, connection->attribute_value_len);
496 
497             // done, see below
498             break;
499 
500         case AVRCP_PARSER_GET_ATTRIBUTE_VALUE:
501             connection->attribute_value[connection->attribute_value_offset++] = byte;
502             connection->list_offset++;
503 
504             if (connection->attribute_value_offset < connection->attribute_value_len) return;
505 
506             // emit (potentially partial) attribute
507             attribute_id = big_endian_read_32(connection->parser_attribute_header, 0);
508             avrcp_controller_emit_now_playing_info_event(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, (avrcp_media_attribute_id_t) attribute_id, connection->attribute_value, connection->attribute_value_len);
509 
510             attribute_total_value_len = big_endian_read_16(connection->parser_attribute_header, 6);
511             if (connection->attribute_value_offset < attribute_total_value_len){
512                 // ignore rest of attribute
513                 connection->parser_state = AVRCP_PARSER_IGNORE_REST_OF_ATTRIBUTE_VALUE;
514                 return;
515             }
516 
517             // done, see below
518             break;
519 
520         case AVRCP_PARSER_IGNORE_REST_OF_ATTRIBUTE_VALUE:
521             connection->attribute_value_offset++;
522             connection->list_offset++;
523 
524             attribute_total_value_len = big_endian_read_16(connection->parser_attribute_header, 6);
525             if (connection->attribute_value_offset < attribute_total_value_len) return;
526 
527             // done, see below
528             break;
529 
530         default:
531             return;
532     }
533 
534     // attribute fully read, check if more to come
535     if (connection->list_offset < connection->list_size){
536         // more to come, reset parser
537         connection->parser_state = AVRCP_PARSER_GET_ATTRIBUTE_HEADER;
538         connection->parser_attribute_header_pos = 0;
539         connection->attribute_value_offset = 0;
540     } else {
541         // fully done
542         avrcp_parser_reset(connection);
543         avrcp_controller_emit_now_playing_info_event_done(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, 0);
544     }
545 }
546 
547 static void avrcp_controller_parse_and_emit_element_attrs(uint8_t * packet, uint16_t num_bytes_to_read, avrcp_connection_t * connection, avrcp_command_type_t ctype){
548     int i;
549     for (i=0;i<num_bytes_to_read;i++){
550         avrcp_parser_process_byte(packet[i], connection, ctype);
551     }
552 }
553 
554 
555 static int avrcp_send_cmd_with_avctp_fragmentation(avrcp_connection_t * connection, avctp_packet_type_t avctp_packet_type){
556     l2cap_reserve_packet_buffer();
557     uint8_t * command = l2cap_get_outgoing_buffer();
558     uint16_t pos = 0;
559     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);
560 
561     // non-fragmented: transport header (1) + PID (2)
562     // fragmented:     transport header (1) + num packets (1) + PID (2)
563 
564     // transport header : transaction label | Packet_type | C/R | IPID (1 == invalid profile identifier)
565     command[pos++] = (connection->transaction_id << 4) | (avctp_packet_type << 2) | (AVRCP_COMMAND_FRAME << 1) | 0;
566 
567     if (avctp_packet_type == AVCTP_START_PACKET){
568         // num packets: (3 bytes overhead (PID, num packets) + command) / (MTU - transport header).
569         // to get number of packets using integer division, we subtract 1 from the data e.g. len = 5, packet size 5 => need 1 packet
570         command[pos++] = ((connection->cmd_operands_fragmented_len + 3 - 1) / (max_frame_size - 1)) + 1;
571     }
572 
573     if ((avctp_packet_type == AVCTP_START_PACKET) || (avctp_packet_type == AVCTP_START_PACKET)){
574         // Profile IDentifier (PID)
575         command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL >> 8;
576         command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL & 0x00FF;
577 
578         // command_type
579         command[pos++] = connection->command_type;
580         // subunit_type | subunit ID
581         command[pos++] = (connection->subunit_type << 3) | connection->subunit_id;
582         // opcode
583         command[pos++] = (uint8_t)connection->command_opcode;
584     }
585 
586     if (avctp_packet_type == AVCTP_SINGLE_PACKET){
587         // operands
588         (void)memcpy(command + pos, connection->cmd_operands,
589                      connection->cmd_operands_length);
590         pos += connection->cmd_operands_length;
591     } else {
592         uint16_t bytes_free = max_frame_size - pos;
593         uint16_t bytes_to_store = connection->cmd_operands_fragmented_len-connection->cmd_operands_fragmented_pos;
594         uint16_t bytes_to_copy = btstack_min(bytes_to_store, bytes_free);
595         (void)memcpy(command + pos,
596                      &connection->cmd_operands_fragmented_buffer[connection->cmd_operands_fragmented_pos],
597                      bytes_to_copy);
598         pos += bytes_to_copy;
599         connection->cmd_operands_fragmented_pos += bytes_to_copy;
600     }
601 
602     return l2cap_send_prepared(connection->l2cap_signaling_cid, pos);
603 }
604 
605 static int avrcp_send_register_notification(avrcp_connection_t * connection, uint8_t event_id){
606     uint8_t command[18];
607     uint16_t pos = 0;
608     // transport header : transaction label | Packet_type | C/R | IPID (1 == invalid profile identifier)
609     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
610     command[pos++] = (connection->transaction_id << 4) | (AVRCP_SINGLE_PACKET << 2) | (AVRCP_COMMAND_FRAME << 1) | 0;
611 
612     command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL >> 8;
613     command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL & 0x00FF;
614     command[pos++] = AVRCP_CTYPE_NOTIFY;
615     command[pos++] = (AVRCP_SUBUNIT_TYPE_PANEL << 3) | AVRCP_SUBUNIT_ID;
616     command[pos++] = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
617 
618     big_endian_store_24(command, pos, BT_SIG_COMPANY_ID);
619     pos += 3;
620     command[pos++] = AVRCP_PDU_ID_REGISTER_NOTIFICATION;
621     command[pos++] = 0;                       // reserved(upper 6) | packet_type -> 0
622     big_endian_store_16(command, pos, 5);     // parameter length
623     pos += 2;
624     command[pos++] = event_id;
625     big_endian_store_32(command, pos, 1);     // send notification on playback position every second, for other notifications it is ignored
626     pos += 4;
627     return l2cap_send(connection->l2cap_signaling_cid, command, pos);
628 }
629 
630 static void avrcp_press_and_hold_timeout_handler(btstack_timer_source_t * timer){
631     UNUSED(timer);
632     avrcp_connection_t * connection = (avrcp_connection_t*) btstack_run_loop_get_timer_context(timer);
633     btstack_run_loop_set_timer(&connection->press_and_hold_cmd_timer, 2000); // 2 seconds timeout
634     btstack_run_loop_add_timer(&connection->press_and_hold_cmd_timer);
635     connection->state = AVCTP_W2_SEND_PRESS_COMMAND;
636     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
637 }
638 
639 static void avrcp_press_and_hold_timer_start(avrcp_connection_t * connection){
640     btstack_run_loop_remove_timer(&connection->press_and_hold_cmd_timer);
641     btstack_run_loop_set_timer_handler(&connection->press_and_hold_cmd_timer, avrcp_press_and_hold_timeout_handler);
642     btstack_run_loop_set_timer_context(&connection->press_and_hold_cmd_timer, connection);
643     btstack_run_loop_set_timer(&connection->press_and_hold_cmd_timer, 2000); // 2 seconds timeout
644     btstack_run_loop_add_timer(&connection->press_and_hold_cmd_timer);
645 }
646 
647 static void avrcp_press_and_hold_timer_stop(avrcp_connection_t * connection){
648     connection->press_and_hold_cmd_active = false;
649     btstack_run_loop_remove_timer(&connection->press_and_hold_cmd_timer);
650 }
651 
652 
653 static uint8_t avrcp_controller_request_pass_through_release_control_cmd(avrcp_connection_t * connection){
654     connection->state = AVCTP_W2_SEND_RELEASE_COMMAND;
655     if (connection->press_and_hold_cmd_active){
656         avrcp_press_and_hold_timer_stop(connection);
657     }
658     connection->operation_id = 0x80 | connection->operation_id;
659     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
660     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
661     return ERROR_CODE_SUCCESS;
662 }
663 
664 static uint8_t avrcp_controller_request_pass_through_press_control_cmd(uint16_t avrcp_cid, avrcp_operation_id_t opid, uint16_t playback_speed, bool continuous_cmd){
665     log_info("Send command %d", opid);
666     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
667     if (!connection){
668         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
669     }
670 
671     if (connection->state != AVCTP_CONNECTION_OPENED){
672         log_error("Connection in wrong state %d, expected %d. avrcp cid 0x%02x", connection->state, AVCTP_CONNECTION_OPENED, avrcp_cid);
673         return ERROR_CODE_COMMAND_DISALLOWED;
674     }
675     connection->state = AVCTP_W2_SEND_PRESS_COMMAND;
676     avrcp_pass_through_command_data_init(connection, opid);
677 
678     if (playback_speed > 0){
679         connection->data[0] = playback_speed;
680         connection->data_len = 1;
681     }
682 
683     connection->press_and_hold_cmd_active = continuous_cmd;
684     if (connection->press_and_hold_cmd_active){
685         avrcp_press_and_hold_timer_start(connection);
686     }
687 
688     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
689     return ERROR_CODE_SUCCESS;
690 }
691 
692 static uint8_t request_single_pass_through_press_control_cmd(uint16_t avrcp_cid, avrcp_operation_id_t opid, uint16_t playback_speed){
693     return avrcp_controller_request_pass_through_press_control_cmd(avrcp_cid, opid, playback_speed, false);
694 }
695 
696 static uint8_t request_continuous_pass_through_press_control_cmd(uint16_t avrcp_cid, avrcp_operation_id_t opid, uint16_t playback_speed){
697     return avrcp_controller_request_pass_through_press_control_cmd(avrcp_cid, opid, playback_speed, true);
698 }
699 
700 static void avrcp_controller_get_capabilities_for_connection(avrcp_connection_t * connection, uint8_t capability_id){
701     connection->state = AVCTP_W2_SEND_COMMAND;
702     avrcp_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_STATUS, AVRCP_PDU_ID_GET_CAPABILITIES);
703 
704     // Parameter Length
705     connection->data_len = 1;
706     connection->data[0] = capability_id;  // capability ID
707 
708     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
709 }
710 
711 static uint8_t avrcp_controller_register_notification(avrcp_connection_t * connection, avrcp_notification_event_id_t event_id){
712     if (connection->target_supported_notifications_queried && (connection->target_supported_notifications & (1 << event_id)) == 0){
713         return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
714     }
715     if ( (connection->notifications_to_deregister & (1 << event_id)) != 0){
716         return ERROR_CODE_COMMAND_DISALLOWED;
717     }
718     if ( (connection->notifications_enabled & (1 << event_id)) != 0){
719         return ERROR_CODE_SUCCESS;
720     }
721     connection->notifications_to_register |= (1 << event_id);
722 
723     if (!connection->target_supported_notifications_queried){
724         connection->target_supported_notifications_suppress_emit_result = true;
725         avrcp_controller_get_capabilities_for_connection(connection, AVRCP_CAPABILITY_ID_EVENT);
726         return ERROR_CODE_SUCCESS;
727     }
728     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
729     return ERROR_CODE_SUCCESS;
730 }
731 
732 static uint8_t avrcp_controller_request_continuation(avrcp_connection_t * connection, avrcp_pdu_id_t pdu_id){
733     connection->state = AVCTP_W2_SEND_COMMAND;
734     avrcp_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_CONTROL, pdu_id);
735 
736     // Parameter Length
737     connection->data_len = 3;
738     big_endian_store_16(connection->data, 0, 1);
739     connection->data[2] = AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES;
740 
741     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
742     return ERROR_CODE_SUCCESS;
743 }
744 
745 static uint8_t avrcp_controller_request_abort_continuation(avrcp_connection_t * connection){
746     return avrcp_controller_request_continuation(connection, AVRCP_PDU_ID_REQUEST_ABORT_CONTINUING_RESPONSE);
747 }
748 
749 static uint8_t avrcp_controller_request_continue_response(avrcp_connection_t * connection){
750     return avrcp_controller_request_continuation(connection, AVRCP_PDU_ID_REQUEST_CONTINUING_RESPONSE);
751 }
752 
753 static void avrcp_controller_handle_notification(avrcp_connection_t *connection, avrcp_command_type_t ctype, uint8_t *payload, uint16_t size) {
754     if (size < 1) return;
755     uint16_t pos = 0;
756     avrcp_notification_event_id_t event_id = (avrcp_notification_event_id_t) payload[pos++];
757     if ( (event_id < AVRCP_NOTIFICATION_EVENT_FIRST_INDEX) || (event_id > AVRCP_NOTIFICATION_EVENT_LAST_INDEX)){
758         return;
759     }
760 
761     uint16_t event_mask = (1 << event_id);
762     uint16_t reset_event_mask = ~event_mask;
763 
764     switch (ctype){
765         case AVRCP_CTYPE_RESPONSE_REJECTED:
766             connection->notifications_to_deregister &= reset_event_mask;
767             connection->notifications_to_register   &= reset_event_mask;
768             connection->initial_status_reported     &= reset_event_mask;
769             avrcp_controller_emit_notification_complete(connection, ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE, event_id, false);
770             return;
771 
772         case AVRCP_CTYPE_RESPONSE_INTERIM:
773             // register as enabled
774             connection->notifications_enabled |= event_mask;
775 
776             // check if initial value is already sent
777             if ( (connection->initial_status_reported & event_mask) != 0 ){
778                 return;
779             }
780             // emit event only once, initially
781             avrcp_controller_emit_notification_complete(connection, ERROR_CODE_SUCCESS, event_id, true);
782             connection->initial_status_reported |= event_mask;
783             // emit initial value after this switch
784             break;
785 
786         case AVRCP_CTYPE_RESPONSE_CHANGED_STABLE:
787             // received change, event is considered de-registered
788             // we are re-enabling it automatically, if it is not
789             // explicitly disabled
790             connection->notifications_enabled &= reset_event_mask;
791             if ((connection->notifications_to_deregister & event_mask) == 0){
792                 avrcp_controller_register_notification(connection, event_id);
793             } else {
794                 connection->notifications_to_deregister &= reset_event_mask;
795                 connection->notifications_to_register   &= reset_event_mask;
796                 connection->initial_status_reported     &= reset_event_mask;
797                 avrcp_controller_emit_notification_complete(connection, ERROR_CODE_SUCCESS, event_id, false);
798             }
799             break;
800 
801         default:
802             return;
803     }
804 
805     avrcp_controller_emit_notification_for_event_id(connection->avrcp_cid, event_id, ctype, payload + pos, size - pos);
806 }
807 
808 #ifdef ENABLE_AVCTP_FRAGMENTATION
809 static void avctp_reassemble_message(avrcp_connection_t * connection, avctp_packet_type_t packet_type, uint8_t *packet, uint16_t size){
810     // after header (transaction label and packet type)
811     uint16_t pos;
812     uint16_t bytes_to_store;
813 
814     switch (packet_type){
815         case AVCTP_START_PACKET:
816             if (size < 2) return;
817 
818             // store header
819             pos = 0;
820             connection->avctp_reassembly_buffer[pos] = packet[pos];
821             pos++;
822             connection->avctp_reassembly_size = pos;
823 
824             // NOTE: num packets not needed for reassembly, ignoring it does not pose security risk -> no need to store it
825             pos++;
826 
827             // PID in reassembled packet is at offset 1, it will be read later after the avctp_reassemble_message with AVCTP_END_PACKET is called
828 
829             bytes_to_store = btstack_min(size - pos, sizeof(connection->avctp_reassembly_buffer) - connection->avctp_reassembly_size);
830             memcpy(&connection->avctp_reassembly_buffer[connection->avctp_reassembly_size], &packet[pos], bytes_to_store);
831             connection->avctp_reassembly_size += bytes_to_store;
832             break;
833 
834         case AVCTP_CONTINUE_PACKET:
835         case AVCTP_END_PACKET:
836             if (size < 1) return;
837 
838             // store remaining data, ignore header
839             pos = 1;
840             bytes_to_store = btstack_min(size - pos, sizeof(connection->avctp_reassembly_buffer) - connection->avctp_reassembly_size);
841             memcpy(&connection->avctp_reassembly_buffer[connection->avctp_reassembly_size], &packet[pos], bytes_to_store);
842             connection->avctp_reassembly_size += bytes_to_store;
843             break;
844 
845         default:
846             return;
847     }
848 }
849 #endif
850 
851 static void avrcp_handle_l2cap_data_packet_for_signaling_connection(avrcp_connection_t * connection, uint8_t *packet, uint16_t size){
852     if (size < 6u) return;
853     uint8_t  pdu_id;
854     avrcp_packet_type_t  vendor_dependent_packet_type;
855 
856     uint16_t pos = 0;
857     connection->last_confirmed_transaction_id = packet[pos] >> 4;
858     avrcp_frame_type_t  frame_type =  (avrcp_frame_type_t)((packet[pos] >> 1) & 0x01);
859     avctp_packet_type_t packet_type = (avctp_packet_type_t)((packet[pos] >> 2) & 0x03);
860     pos++;
861 
862     if (frame_type != AVRCP_RESPONSE_FRAME) return;
863 
864     switch (packet_type){
865         case AVCTP_SINGLE_PACKET:
866             break;
867 
868 #ifdef ENABLE_AVCTP_FRAGMENTATION
869         case AVCTP_START_PACKET:
870         case AVCTP_CONTINUE_PACKET:
871             avctp_reassemble_message(connection, packet_type, packet, size);
872             return;
873 
874         case AVCTP_END_PACKET:
875             avctp_reassemble_message(connection, packet_type, packet, size);
876 
877             packet = connection->avctp_reassembly_buffer;
878             size   = connection->avctp_reassembly_size;
879             break;
880 #endif
881 
882         default:
883             return;
884     }
885 
886     pos += 2; // PID
887 
888     avrcp_command_type_t ctype = (avrcp_command_type_t) packet[pos++];
889 
890 #ifdef ENABLE_LOG_INFO
891     uint8_t byte_value = packet[pos];
892     avrcp_subunit_type_t subunit_type = (avrcp_subunit_type_t) (byte_value >> 3);
893     avrcp_subunit_type_t subunit_id   = (avrcp_subunit_type_t) (byte_value & 0x07);
894 #endif
895     pos++;
896 
897     uint8_t opcode = packet[pos++];
898     uint16_t param_length;
899 
900     switch (opcode){
901         case AVRCP_CMD_OPCODE_SUBUNIT_INFO:{
902             if (connection->state != AVCTP_W2_RECEIVE_RESPONSE) return;
903             connection->state = AVCTP_CONNECTION_OPENED;
904 
905 #ifdef ENABLE_LOG_INFO
906             // page, extension code (1)
907             pos++;
908             uint8_t unit_type = packet[pos] >> 3;
909             uint8_t max_subunit_ID = packet[pos] & 0x07;
910             log_info("SUBUNIT INFO response: ctype 0x%02x (0C), subunit_type 0x%02x (1F), subunit_id 0x%02x (07), opcode 0x%02x (30), unit_type 0x%02x, max_subunit_ID %d", ctype, subunit_type, subunit_id, opcode, unit_type, max_subunit_ID);
911 #endif
912             break;
913         }
914         case AVRCP_CMD_OPCODE_UNIT_INFO:{
915             if (connection->state != AVCTP_W2_RECEIVE_RESPONSE) return;
916             connection->state = AVCTP_CONNECTION_OPENED;
917 
918 #ifdef ENABLE_LOG_INFO
919             // byte value 7 (1)
920             pos++;
921             uint8_t unit_type = packet[pos] >> 3;
922             uint8_t unit = packet[pos] & 0x07;
923             pos++;
924             uint32_t company_id = big_endian_read_24(packet, pos);
925             log_info("UNIT INFO response: ctype 0x%02x (0C), subunit_type 0x%02x (1F), subunit_id 0x%02x (07), opcode 0x%02x (30), unit_type 0x%02x, unit %d, company_id 0x%06" PRIx32,
926                 ctype, subunit_type, subunit_id, opcode, unit_type, unit, company_id);
927 #endif
928             break;
929         }
930         case AVRCP_CMD_OPCODE_VENDOR_DEPENDENT:
931 
932             if ((size - pos) < 7) return;
933 
934             // Company ID (3)
935             pos += 3;
936             pdu_id = packet[pos++];
937             vendor_dependent_packet_type = (avrcp_packet_type_t)(packet[pos++] & 0x03);
938             param_length = big_endian_read_16(packet, pos);
939             pos += 2;
940 
941             if ((size - pos) < param_length) return;
942 
943             // handle asynchronous notifications, without changing state
944             if (pdu_id == AVRCP_PDU_ID_REGISTER_NOTIFICATION){
945                 avrcp_controller_handle_notification(connection, ctype, packet + pos, size - pos);
946                 break;
947             }
948 
949             if (connection->state != AVCTP_W2_RECEIVE_RESPONSE){
950                 log_info("AVRCP_CMD_OPCODE_VENDOR_DEPENDENT state %d", connection->state);
951                 return;
952             }
953             connection->state = AVCTP_CONNECTION_OPENED;
954 
955             log_info("VENDOR DEPENDENT response: pdu id 0x%02x, param_length %d, status %s", pdu_id, param_length, avrcp_ctype2str(ctype));
956             switch (pdu_id){
957                 case AVRCP_PDU_ID_GET_CURRENT_PLAYER_APPLICATION_SETTING_VALUE:{
958                     uint8_t num_attributes = packet[pos++];
959                     int i;
960                     avrcp_repeat_mode_t  repeat_mode =  AVRCP_REPEAT_MODE_INVALID;
961                     avrcp_shuffle_mode_t shuffle_mode = AVRCP_SHUFFLE_MODE_INVALID;
962                     for (i = 0; i < num_attributes; i++){
963                         uint8_t attribute_id    = packet[pos++];
964                         uint8_t value = packet[pos++];
965                         switch (attribute_id){
966                             case 0x02:
967                                 repeat_mode = (avrcp_repeat_mode_t) value;
968                                 break;
969                             case 0x03:
970                                 shuffle_mode = (avrcp_shuffle_mode_t) value;
971                                 break;
972                             default:
973                                 break;
974                         }
975                     }
976                     avrcp_controller_emit_repeat_and_shuffle_mode(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, repeat_mode, shuffle_mode);
977                     break;
978                 }
979 
980                 case AVRCP_PDU_ID_SET_PLAYER_APPLICATION_SETTING_VALUE:{
981                     uint16_t offset = 0;
982                     uint8_t event[6];
983                     event[offset++] = HCI_EVENT_AVRCP_META;
984                     event[offset++] = sizeof(event) - 2;
985                     event[offset++] = AVRCP_SUBEVENT_PLAYER_APPLICATION_VALUE_RESPONSE;
986                     little_endian_store_16(event, offset, connection->avrcp_cid);
987                     offset += 2;
988                     event[offset++] = ctype;
989                     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
990                     break;
991                 }
992 
993                 case AVRCP_PDU_ID_SET_ABSOLUTE_VOLUME:{
994                     uint16_t offset = 0;
995                     uint8_t event[7];
996                     event[offset++] = HCI_EVENT_AVRCP_META;
997                     event[offset++] = sizeof(event) - 2;
998                     event[offset++] = AVRCP_SUBEVENT_SET_ABSOLUTE_VOLUME_RESPONSE;
999                     little_endian_store_16(event, offset, connection->avrcp_cid);
1000                     offset += 2;
1001                     event[offset++] = ctype;
1002                     event[offset++] = packet[pos++];
1003                     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
1004                     break;
1005                 }
1006 
1007                 case AVRCP_PDU_ID_GET_CAPABILITIES:{
1008                     avrcp_capability_id_t capability_id = (avrcp_capability_id_t) packet[pos++];
1009                     uint8_t capability_count = 0;
1010                     if (param_length > 1){
1011                         capability_count = packet[pos++];
1012                     }
1013                     uint16_t i;
1014                     uint16_t offset = 0;
1015                     uint8_t event[10];
1016 
1017                     switch (capability_id){
1018 
1019                         case AVRCP_CAPABILITY_ID_COMPANY:
1020                             for (i = 0; (i < capability_count) && ((size - pos) >= 3); i++){
1021                                 uint32_t company_id = big_endian_read_24(packet, pos);
1022                                 pos += 3;
1023                                 log_info("  0x%06" PRIx32 ", ", company_id);
1024 
1025                                 offset = 0;
1026                                 event[offset++] = HCI_EVENT_AVRCP_META;
1027                                 event[offset++] = sizeof(event) - 2;
1028                                 event[offset++] = AVRCP_SUBEVENT_GET_CAPABILITY_COMPANY_ID;
1029                                 little_endian_store_16(event, offset, connection->avrcp_cid);
1030                                 offset += 2;
1031                                 event[offset++] = ctype;
1032                                 event[offset++] = 0;
1033                                 little_endian_store_24(event, offset, company_id);
1034                                 offset += 3;
1035                                 (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, offset);
1036                             }
1037 
1038                             offset = 0;
1039                             event[offset++] = HCI_EVENT_AVRCP_META;
1040                             event[offset++] = sizeof(event) - 2;
1041                             event[offset++] = AVRCP_SUBEVENT_GET_CAPABILITY_COMPANY_ID_DONE;
1042                             little_endian_store_16(event, offset, connection->avrcp_cid);
1043                             offset += 2;
1044                             event[offset++] = ctype;
1045                             event[offset++] = 0;
1046                             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, offset);
1047                             break;
1048 
1049                         case AVRCP_CAPABILITY_ID_EVENT:
1050                             for (i = 0; (i < capability_count) && ((size - pos) >= 1); i++){
1051                                 uint8_t event_id = packet[pos++];
1052                                 connection->target_supported_notifications |= (1 << event_id);
1053                             }
1054 
1055                             // if the get supported events query is triggered by avrcp_controller_enable_notification call,
1056                             // avrcp_controller_emit_supported_events should be suppressed
1057                             if (connection->target_supported_notifications_suppress_emit_result){
1058                                 connection->target_supported_notifications_suppress_emit_result = false;
1059                                 // also, notification might not be supported
1060                                 // if so, emit AVRCP_SUBEVENT_ENABLE_NOTIFICATION_COMPLETE event to app,
1061                                 // and update notifications_to_register bitmap
1062                                 for (i = (uint8_t)AVRCP_NOTIFICATION_EVENT_FIRST_INDEX; i < (uint8_t) AVRCP_NOTIFICATION_EVENT_LAST_INDEX; i++){
1063                                     if ((connection->notifications_to_register & (1<<i)) != 0){
1064                                         if ((connection->target_supported_notifications & (1<<i)) == 0){
1065                                             avrcp_controller_emit_notification_complete(connection, ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE, i, false);
1066                                             connection->notifications_to_register &= ~(1 << i);
1067                                         }
1068                                     }
1069                                 }
1070                                 break;
1071                             }
1072                             // supported events are emitted only if the get supported events query
1073                             // is triggered by avrcp_controller_get_supported_events call
1074                             avrcp_controller_emit_supported_events(connection);
1075                             break;
1076 
1077                         default:
1078                             // ignore
1079                             break;
1080                     }
1081                     break;
1082                 }
1083 
1084                 case AVRCP_PDU_ID_GET_PLAY_STATUS:{
1085                     uint32_t song_length = big_endian_read_32(packet, pos);
1086                     pos += 4;
1087                     uint32_t song_position = big_endian_read_32(packet, pos);
1088                     pos += 4;
1089                     uint8_t play_status = packet[pos];
1090 
1091                     uint8_t event[15];
1092                     int offset = 0;
1093                     event[offset++] = HCI_EVENT_AVRCP_META;
1094                     event[offset++] = sizeof(event) - 2;
1095                     event[offset++] = AVRCP_SUBEVENT_PLAY_STATUS;
1096                     little_endian_store_16(event, offset, connection->avrcp_cid);
1097                     offset += 2;
1098                     event[offset++] = ctype;
1099                     little_endian_store_32(event, offset, song_length);
1100                     offset += 4;
1101                     little_endian_store_32(event, offset, song_position);
1102                     offset += 4;
1103                     event[offset++] = play_status;
1104                     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
1105                     break;
1106                 }
1107 
1108                 case AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES:{
1109                     switch (vendor_dependent_packet_type){
1110                         case AVRCP_START_PACKET:
1111                         case AVRCP_SINGLE_PACKET:
1112                             avrcp_parser_reset(connection);
1113                             connection->list_size = param_length;
1114                             connection->num_attributes = packet[pos++];
1115 
1116                             avrcp_controller_parse_and_emit_element_attrs(packet+pos, size-pos, connection, ctype);
1117                             if (vendor_dependent_packet_type == AVRCP_START_PACKET){
1118                                 avrcp_controller_request_continue_response(connection);
1119                             }
1120                             break;
1121                         case AVRCP_CONTINUE_PACKET:
1122                         case AVRCP_END_PACKET:
1123                             connection->num_received_fragments++;
1124 
1125                             if (connection->num_received_fragments < connection->max_num_fragments){
1126                                 avrcp_controller_parse_and_emit_element_attrs(packet+pos, size-pos, connection, ctype);
1127 
1128                                 if (vendor_dependent_packet_type == AVRCP_CONTINUE_PACKET){
1129                                     avrcp_controller_request_continue_response(connection);
1130                                 }
1131                             } else {
1132                                 avrcp_controller_emit_now_playing_info_event_done(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, 1);
1133                                 avrcp_parser_reset(connection);
1134                                 avrcp_controller_request_abort_continuation(connection);
1135                             }
1136                             break;
1137                         default:
1138                             // TODO check
1139                             btstack_assert(false);
1140                             break;
1141                     }
1142                 }
1143                 default:
1144                     break;
1145             }
1146             break;
1147         case AVRCP_CMD_OPCODE_PASS_THROUGH:{
1148             if ((size - pos) < 1) return;
1149             uint8_t operation_id = packet[pos++];
1150             switch (connection->state){
1151                 case AVCTP_W2_RECEIVE_PRESS_RESPONSE:
1152                     // trigger release for simple command:
1153                     if (!connection->press_and_hold_cmd_active){
1154                         connection->state = AVCTP_W2_SEND_RELEASE_COMMAND;
1155                         break;
1156                     }
1157                     // for press and hold, send release if it just has been requested, otherwise, wait for next repeat
1158                     if (connection->press_and_hold_cmd_release){
1159                         connection->press_and_hold_cmd_release = false;
1160                         connection->state = AVCTP_W2_SEND_RELEASE_COMMAND;
1161                     } else {
1162                         connection->state = AVCTP_W4_STOP;
1163                     }
1164                     break;
1165                 case AVCTP_W2_RECEIVE_RESPONSE:
1166                     connection->state = AVCTP_CONNECTION_OPENED;
1167                     break;
1168                 default:
1169                     break;
1170             }
1171             if (connection->state == AVCTP_W4_STOP){
1172                 avrcp_controller_emit_operation_status(avrcp_controller_context.avrcp_callback, AVRCP_SUBEVENT_OPERATION_START, connection->avrcp_cid, ctype, operation_id);
1173             }
1174             if (connection->state == AVCTP_CONNECTION_OPENED) {
1175                 // RELEASE response
1176                 operation_id = operation_id & 0x7F;
1177                 avrcp_controller_emit_operation_status(avrcp_controller_context.avrcp_callback, AVRCP_SUBEVENT_OPERATION_COMPLETE, connection->avrcp_cid, ctype, operation_id);
1178             }
1179             if (connection->state == AVCTP_W2_SEND_RELEASE_COMMAND){
1180                 // PRESS response
1181                 avrcp_controller_request_pass_through_release_control_cmd(connection);
1182             }
1183             break;
1184         }
1185         default:
1186             break;
1187     }
1188 
1189     // trigger pending notification reqistrations
1190     if ((connection->state == AVCTP_CONNECTION_OPENED) && connection->notifications_to_register){
1191         avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1192     }
1193 }
1194 
1195 static void avrcp_controller_handle_can_send_now(avrcp_connection_t * connection){
1196     switch (connection->state){
1197         case AVCTP_W2_SEND_PRESS_COMMAND:
1198             connection->state = AVCTP_W2_RECEIVE_PRESS_RESPONSE;
1199             avrcp_send_cmd_with_avctp_fragmentation(connection, AVCTP_SINGLE_PACKET);
1200             return;
1201         case AVCTP_W2_SEND_COMMAND:
1202         case AVCTP_W2_SEND_RELEASE_COMMAND:
1203             connection->state = AVCTP_W2_RECEIVE_RESPONSE;
1204             avrcp_send_cmd_with_avctp_fragmentation(connection, AVCTP_SINGLE_PACKET);
1205             return;
1206         case AVCTP_W2_SEND_AVCTP_FRAGMENTED_MESSAGE:
1207             if (connection->cmd_operands_fragmented_pos == 0){
1208                  avrcp_send_cmd_with_avctp_fragmentation(connection, AVCTP_START_PACKET);
1209                  avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1210             } else {
1211                 if ((connection->cmd_operands_fragmented_len - connection->cmd_operands_fragmented_pos) > avrcp_get_max_payload_size_for_avctp_packet_type(connection, AVCTP_CONTINUE_PACKET)){
1212                      avrcp_send_cmd_with_avctp_fragmentation(connection, AVCTP_CONTINUE_PACKET);
1213                      avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1214                  } else {
1215                     connection->state = AVCTP_W2_RECEIVE_RESPONSE;
1216                     avrcp_send_cmd_with_avctp_fragmentation(connection, AVCTP_END_PACKET);
1217                  }
1218             }
1219             return;
1220         default:
1221             break;
1222     }
1223     // send register notification if queued
1224     if (connection->notifications_to_register != 0){
1225         uint8_t event_id;
1226         for (event_id = (uint8_t)AVRCP_NOTIFICATION_EVENT_FIRST_INDEX; event_id < (uint8_t)AVRCP_NOTIFICATION_EVENT_LAST_INDEX; event_id++){
1227             if (connection->notifications_to_register & (1<<event_id)){
1228                 connection->notifications_to_register &= ~ (1 << event_id);
1229                 avrcp_send_register_notification(connection, event_id);
1230                 return;
1231             }
1232         }
1233     }
1234 }
1235 
1236 static void avrcp_controller_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
1237     avrcp_connection_t * connection;
1238 
1239     switch (packet_type) {
1240         case L2CAP_DATA_PACKET:
1241             connection = avrcp_get_connection_for_l2cap_signaling_cid_for_role(AVRCP_CONTROLLER, channel);
1242             avrcp_handle_l2cap_data_packet_for_signaling_connection(connection, packet, size);
1243             break;
1244 
1245         case HCI_EVENT_PACKET:
1246             switch (hci_event_packet_get_type(packet)){
1247                 case L2CAP_EVENT_CAN_SEND_NOW:
1248                     connection = avrcp_get_connection_for_l2cap_signaling_cid_for_role(AVRCP_CONTROLLER, channel);
1249                     avrcp_controller_handle_can_send_now(connection);
1250                     break;
1251             default:
1252                 break;
1253         }
1254         default:
1255             break;
1256     }
1257 }
1258 
1259 void avrcp_controller_create_sdp_record(uint8_t * service, uint32_t service_record_handle, uint16_t supported_features, const char * service_name, const char * service_provider_name){
1260     avrcp_create_sdp_record(1, service, service_record_handle, avrcp_controller_supports_browsing(supported_features), supported_features, service_name, service_provider_name);
1261 }
1262 
1263 void avrcp_controller_init(void){
1264     avrcp_controller_context.role = AVRCP_CONTROLLER;
1265     avrcp_controller_context.packet_handler = avrcp_controller_packet_handler;
1266     avrcp_register_controller_packet_handler(&avrcp_controller_packet_handler);
1267 }
1268 
1269 void avrcp_controller_deinit(void){
1270     memset(&avrcp_controller_context, 0, sizeof(avrcp_context_t));
1271 }
1272 
1273 void avrcp_controller_register_packet_handler(btstack_packet_handler_t callback){
1274     btstack_assert(callback != NULL);
1275     avrcp_controller_context.avrcp_callback = callback;
1276 }
1277 
1278 
1279 uint8_t avrcp_controller_play(uint16_t avrcp_cid){
1280     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PLAY, 0);
1281 }
1282 
1283 uint8_t avrcp_controller_stop(uint16_t avrcp_cid){
1284     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_STOP, 0);
1285 }
1286 
1287 uint8_t avrcp_controller_pause(uint16_t avrcp_cid){
1288     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PAUSE, 0);
1289 }
1290 
1291 uint8_t avrcp_controller_forward(uint16_t avrcp_cid){
1292     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FORWARD, 0);
1293 }
1294 
1295 uint8_t avrcp_controller_backward(uint16_t avrcp_cid){
1296     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_BACKWARD, 0);
1297 }
1298 
1299 uint8_t avrcp_controller_volume_up(uint16_t avrcp_cid){
1300     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_UP, 0);
1301 }
1302 
1303 uint8_t avrcp_controller_volume_down(uint16_t avrcp_cid){
1304     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_DOWN, 0);
1305 }
1306 
1307 uint8_t avrcp_controller_mute(uint16_t avrcp_cid){
1308     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_MUTE, 0);
1309 }
1310 
1311 uint8_t avrcp_controller_skip(uint16_t avrcp_cid){
1312     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_SKIP, 0);
1313 }
1314 
1315 uint8_t avrcp_controller_fast_forward(uint16_t avrcp_cid){
1316     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FAST_FORWARD, 0);
1317 }
1318 
1319 uint8_t avrcp_controller_rewind(uint16_t avrcp_cid){
1320     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_REWIND, 0);
1321 }
1322 
1323 /* start continuous cmds */
1324 
1325 uint8_t avrcp_controller_start_press_and_hold_cmd(uint16_t avrcp_cid, avrcp_operation_id_t operation_id){
1326     return request_continuous_pass_through_press_control_cmd(avrcp_cid, operation_id, 0);
1327 }
1328 
1329 uint8_t avrcp_controller_press_and_hold_play(uint16_t avrcp_cid){
1330     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PLAY, 0);
1331 }
1332 uint8_t avrcp_controller_press_and_hold_stop(uint16_t avrcp_cid){
1333     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_STOP, 0);
1334 }
1335 uint8_t avrcp_controller_press_and_hold_pause(uint16_t avrcp_cid){
1336     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PAUSE, 0);
1337 }
1338 uint8_t avrcp_controller_press_and_hold_forward(uint16_t avrcp_cid){
1339     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FORWARD, 0);
1340 }
1341 uint8_t avrcp_controller_press_and_hold_backward(uint16_t avrcp_cid){
1342     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_BACKWARD, 0);
1343 }
1344 uint8_t avrcp_controller_press_and_hold_fast_forward(uint16_t avrcp_cid){
1345     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FAST_FORWARD, 0);
1346 }
1347 uint8_t avrcp_controller_press_and_hold_rewind(uint16_t avrcp_cid){
1348     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_REWIND, 0);
1349 }
1350 uint8_t avrcp_controller_press_and_hold_volume_up(uint16_t avrcp_cid){
1351     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_UP, 0);
1352 }
1353 uint8_t avrcp_controller_press_and_hold_volume_down(uint16_t avrcp_cid){
1354     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_DOWN, 0);
1355 }
1356 uint8_t avrcp_controller_press_and_hold_mute(uint16_t avrcp_cid){
1357     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_MUTE, 0);
1358 }
1359 
1360 /* stop continuous cmds */
1361 uint8_t avrcp_controller_release_press_and_hold_cmd(uint16_t avrcp_cid){
1362     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1363     if (!connection){
1364         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1365     }
1366 
1367     switch (connection->state){
1368         // respond when we receive response for (repeated) press command
1369         case AVCTP_W2_RECEIVE_PRESS_RESPONSE:
1370             connection->press_and_hold_cmd_release = true;
1371             break;
1372 
1373         // release already sent or on the way, nothing to do
1374         case AVCTP_W2_RECEIVE_RESPONSE:
1375         case AVCTP_W2_SEND_RELEASE_COMMAND:
1376             break;
1377 
1378         // about to send next repeated press command or wait for it -> release right away
1379         case AVCTP_W2_SEND_PRESS_COMMAND:
1380         case AVCTP_W4_STOP:
1381             return avrcp_controller_request_pass_through_release_control_cmd(connection);
1382 
1383         // otherwise reject request
1384         default:
1385             return ERROR_CODE_COMMAND_DISALLOWED;
1386     }
1387     return ERROR_CODE_SUCCESS;
1388 }
1389 
1390 uint8_t avrcp_controller_enable_notification(uint16_t avrcp_cid, avrcp_notification_event_id_t event_id){
1391     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1392     if (!connection){
1393         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1394     }
1395     return avrcp_controller_register_notification(connection, event_id);
1396 }
1397 
1398 uint8_t avrcp_controller_disable_notification(uint16_t avrcp_cid, avrcp_notification_event_id_t event_id){
1399     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1400     if (!connection){
1401         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1402     }
1403     if (!connection->target_supported_notifications_queried){
1404         return ERROR_CODE_COMMAND_DISALLOWED;
1405     }
1406 
1407     if ((connection->target_supported_notifications & (1 << event_id)) == 0){
1408         return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
1409     }
1410 
1411     if ((connection->notifications_enabled & (1 << event_id)) == 0){
1412         return ERROR_CODE_SUCCESS;
1413     }
1414 
1415     connection->notifications_to_deregister |= (1 << event_id);
1416     return ERROR_CODE_SUCCESS;
1417 }
1418 
1419 uint8_t avrcp_controller_unit_info(uint16_t avrcp_cid){
1420     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1421     if (!connection){
1422         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1423     }
1424     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1425 
1426     connection->state = AVCTP_W2_SEND_COMMAND;
1427     avrcp_custome_command_data_init(connection, AVRCP_CMD_OPCODE_UNIT_INFO, AVRCP_CTYPE_STATUS, AVRCP_SUBUNIT_TYPE_UNIT, AVRCP_SUBUNIT_ID_IGNORE, 0, 0);
1428 
1429     memset(connection->data, 0xFF, 5);
1430     connection->data_len = 5;
1431     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1432     return ERROR_CODE_SUCCESS;
1433 }
1434 
1435 uint8_t avrcp_controller_subunit_info(uint16_t avrcp_cid){
1436     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1437     if (!connection){
1438         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1439     }
1440     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1441 
1442     connection->state = AVCTP_W2_SEND_COMMAND;
1443     avrcp_custome_command_data_init(connection, AVRCP_CMD_OPCODE_SUBUNIT_INFO, AVRCP_CTYPE_STATUS, AVRCP_SUBUNIT_TYPE_UNIT, AVRCP_SUBUNIT_ID_IGNORE, 0, 0);
1444 
1445     memset(connection->data, 0xFF, 5);
1446     connection->data[0] = 7; // page: 0, extention_code: 7
1447     connection->data_len = 5;
1448     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1449     return ERROR_CODE_SUCCESS;
1450 }
1451 
1452 uint8_t avrcp_controller_get_supported_company_ids(uint16_t avrcp_cid){
1453     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1454     if (!connection){
1455         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1456     }
1457     if (connection->state != AVCTP_CONNECTION_OPENED){
1458         return ERROR_CODE_COMMAND_DISALLOWED;
1459     }
1460     avrcp_controller_get_capabilities_for_connection(connection, AVRCP_CAPABILITY_ID_COMPANY);
1461     return ERROR_CODE_SUCCESS;
1462 }
1463 
1464 uint8_t avrcp_controller_get_supported_events(uint16_t avrcp_cid){
1465     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1466     if (!connection){
1467         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1468     }
1469     if (connection->state != AVCTP_CONNECTION_OPENED){
1470         return ERROR_CODE_COMMAND_DISALLOWED;
1471     }
1472 
1473     if (!connection->target_supported_notifications_queried){
1474         connection->target_supported_notifications_queried = true;
1475         avrcp_controller_get_capabilities_for_connection(connection, AVRCP_CAPABILITY_ID_EVENT);
1476         return ERROR_CODE_SUCCESS;
1477     }
1478 
1479     avrcp_controller_emit_supported_events(connection);
1480     return ERROR_CODE_SUCCESS;
1481 }
1482 
1483 uint8_t avrcp_controller_get_play_status(uint16_t avrcp_cid){
1484     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1485     if (!connection){
1486         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1487     }
1488     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1489 
1490     connection->state = AVCTP_W2_SEND_COMMAND;
1491     avrcp_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_STATUS, AVRCP_PDU_ID_GET_PLAY_STATUS);
1492 
1493     connection->data_len = 0;
1494     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1495     return ERROR_CODE_SUCCESS;
1496 }
1497 
1498 uint8_t avrcp_controller_set_addressed_player(uint16_t avrcp_cid, uint16_t addressed_player_id){
1499     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1500     if (!connection){
1501         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1502     }
1503     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1504 
1505     connection->state = AVCTP_W2_SEND_COMMAND;
1506     avrcp_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_CONTROL, AVRCP_PDU_ID_SET_ADDRESSED_PLAYER);
1507 
1508     connection->data_len = 2;
1509     big_endian_store_16(connection->data, 0, addressed_player_id);
1510 
1511     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1512     return ERROR_CODE_SUCCESS;
1513 }
1514 
1515 uint8_t avrcp_controller_get_element_attributes(uint16_t avrcp_cid, uint8_t num_attributes, avrcp_media_attribute_id_t * attributes){
1516     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1517     if (!connection){
1518         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1519     }
1520 
1521     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1522 
1523     if (num_attributes >= AVRCP_MEDIA_ATTR_RESERVED) {
1524         return ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS;
1525     }
1526 
1527     connection->state = AVCTP_W2_SEND_COMMAND;
1528     avrcp_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_STATUS, AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES);
1529 
1530     uint8_t pos = 0;
1531     // write 8 bytes value
1532     memset(connection->data, pos, 8); // identifier: PLAYING
1533     pos += 8;
1534 
1535     uint8_t num_attributes_index = pos;
1536     pos++;
1537 
1538     // If num_attributes is set to zero, all attribute information shall be returned,
1539     // and the AttributeID field is omitted
1540     connection->data[num_attributes_index] = 0;
1541     uint8_t i;
1542     for (i = 0; i < num_attributes; i++){
1543         // ignore invalid attribute ID and "get all attributes"
1544         if (AVRCP_MEDIA_ATTR_ALL > attributes[i] && attributes[i] < AVRCP_MEDIA_ATTR_RESERVED){
1545             // every attribute is 4 bytes long
1546             big_endian_store_32(connection->data, pos, attributes[i]);
1547             pos += 4;
1548             connection->data[num_attributes_index]++;
1549         }
1550     }
1551 
1552     // Parameter Length
1553     connection->data_len = pos;
1554 
1555     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1556     return ERROR_CODE_SUCCESS;
1557 }
1558 
1559 uint8_t avrcp_controller_get_now_playing_info(uint16_t avrcp_cid){
1560     return avrcp_controller_get_element_attributes(avrcp_cid, 0, NULL);
1561 }
1562 
1563 uint8_t avrcp_controller_get_now_playing_info_for_media_attribute_id(uint16_t avrcp_cid, avrcp_media_attribute_id_t media_attribute_id){
1564     if (media_attribute_id == AVRCP_MEDIA_ATTR_ALL){
1565         return avrcp_controller_get_now_playing_info(avrcp_cid);
1566     }
1567     return avrcp_controller_get_element_attributes(avrcp_cid, 1, &media_attribute_id);
1568 }
1569 
1570 uint8_t avrcp_controller_set_absolute_volume(uint16_t avrcp_cid, uint8_t volume){
1571      avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1572     if (!connection){
1573         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1574     }
1575 
1576     //
1577     // allow sending of multiple set abs volume commands without waiting for response
1578     //
1579     uint8_t status = ERROR_CODE_COMMAND_DISALLOWED;
1580     switch (connection->state){
1581         case AVCTP_CONNECTION_OPENED:
1582             status = ERROR_CODE_SUCCESS;
1583             break;
1584         case AVCTP_W2_RECEIVE_RESPONSE:
1585             // - is pending response also set abs volume
1586             if (connection->command_opcode  != AVRCP_CMD_OPCODE_VENDOR_DEPENDENT) break;
1587             if (connection->command_type    != AVRCP_CTYPE_CONTROL)               break;
1588             if (connection->subunit_type    != AVRCP_SUBUNIT_TYPE_PANEL)          break;
1589             if (connection->subunit_id      != AVRCP_SUBUNIT_ID)                  break;
1590             if (connection->pdu_id          != AVRCP_PDU_ID_SET_ABSOLUTE_VOLUME)  break;
1591             // - is next transaction id valid in window
1592             if (avrcp_controller_is_transaction_id_valid(connection, avrcp_controller_calc_next_transaction_label(connection->transaction_id_counter)) == false) break;
1593             status = ERROR_CODE_SUCCESS;
1594             break;
1595         default:
1596             break;
1597     }
1598     if (status != ERROR_CODE_SUCCESS) return status;
1599 
1600     connection->state = AVCTP_W2_SEND_COMMAND;
1601     avrcp_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_CONTROL, AVRCP_PDU_ID_SET_ABSOLUTE_VOLUME);
1602 
1603     // Parameter Length
1604     connection->data_len = 1;
1605     connection->data[0] = volume;
1606 
1607     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1608     return ERROR_CODE_SUCCESS;
1609 }
1610 
1611 uint8_t avrcp_controller_query_shuffle_and_repeat_modes(uint16_t avrcp_cid){
1612     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1613     if (!connection){
1614         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1615     }
1616     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1617 
1618     connection->state = AVCTP_W2_SEND_COMMAND;
1619     avrcp_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_STATUS, AVRCP_PDU_ID_GET_CURRENT_PLAYER_APPLICATION_SETTING_VALUE);
1620 
1621     connection->data_len = 5;
1622     connection->data[0] = 4;                     // NumPlayerApplicationSettingAttributeID
1623     // PlayerApplicationSettingAttributeID1 AVRCP Spec, Appendix F, 133
1624     connection->data[1] = 0x01;   // equalizer  (1-OFF, 2-ON)
1625     connection->data[2] = 0x02;   // repeat     (1-off, 2-single track, 3-all tracks, 4-group repeat)
1626     connection->data[3] = 0x03;   // shuffle    (1-off, 2-all tracks, 3-group shuffle)
1627     connection->data[4] = 0x04;   // scan       (1-off, 2-all tracks, 3-group scan)
1628 
1629     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1630     return ERROR_CODE_SUCCESS;
1631 }
1632 
1633 static uint8_t avrcp_controller_set_current_player_application_setting_value(uint16_t avrcp_cid, uint8_t attr_id, uint8_t attr_value){
1634     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1635     if (!connection){
1636         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1637     }
1638     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1639 
1640     connection->state = AVCTP_W2_SEND_COMMAND;
1641     avrcp_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_CONTROL, AVRCP_PDU_ID_SET_PLAYER_APPLICATION_SETTING_VALUE);
1642 
1643     // Parameter Length
1644     connection->data_len = 3;
1645     connection->data[0]  = 2;
1646     connection->data[1]  = attr_id;
1647     connection->data[2]  = attr_value;
1648 
1649     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1650     return ERROR_CODE_SUCCESS;
1651 }
1652 
1653 uint8_t avrcp_controller_set_shuffle_mode(uint16_t avrcp_cid, avrcp_shuffle_mode_t mode){
1654     if ((mode < AVRCP_SHUFFLE_MODE_OFF) || (mode > AVRCP_SHUFFLE_MODE_GROUP)) return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
1655     return avrcp_controller_set_current_player_application_setting_value(avrcp_cid, 0x03, mode);
1656 }
1657 
1658 uint8_t avrcp_controller_set_repeat_mode(uint16_t avrcp_cid, avrcp_repeat_mode_t mode){
1659     if ((mode < AVRCP_REPEAT_MODE_OFF) || (mode > AVRCP_REPEAT_MODE_GROUP)) return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
1660     return avrcp_controller_set_current_player_application_setting_value(avrcp_cid, 0x02, mode);
1661 }
1662 
1663 uint8_t avrcp_controller_play_item_for_scope(uint16_t avrcp_cid, uint8_t * uid, uint16_t uid_counter, avrcp_browsing_scope_t scope){
1664     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1665     if (!connection){
1666         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1667     }
1668     if (connection->state != AVCTP_CONNECTION_OPENED){
1669         log_error("Connection in wrong state, expected %d, received %d", AVCTP_CONNECTION_OPENED, connection->state);
1670         return ERROR_CODE_COMMAND_DISALLOWED;
1671     }
1672     connection->state = AVCTP_W2_SEND_COMMAND;
1673     avrcp_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_CONTROL, AVRCP_PDU_ID_PLAY_ITEM);
1674 
1675     // Parameter Length
1676     connection->data_len = 11;
1677     connection->data[0]  = scope;
1678     memset(&connection->data[1], 0, 8);
1679     if (uid){
1680         (void)memcpy(&connection->data[1], uid, 8);
1681     }
1682     big_endian_store_16(connection->data, 9, uid_counter);
1683 
1684     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1685     return ERROR_CODE_SUCCESS;
1686 }
1687 
1688 uint8_t avrcp_controller_add_item_from_scope_to_now_playing_list(uint16_t avrcp_cid, uint8_t * uid, uint16_t uid_counter, avrcp_browsing_scope_t scope){
1689     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1690     if (!connection){
1691         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1692     }
1693     if (connection->state != AVCTP_CONNECTION_OPENED){
1694         log_error("Connection in wrong state, expected %d, received %d", AVCTP_CONNECTION_OPENED, connection->state);
1695         return ERROR_CODE_COMMAND_DISALLOWED;
1696     }
1697 
1698     connection->state = AVCTP_W2_SEND_COMMAND;
1699     avrcp_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_CONTROL, AVRCP_PDU_ID_ADD_TO_NOW_PLAYING);
1700 
1701     // Parameter Length
1702     connection->data_len = 11;
1703     connection->data[0]  = scope;
1704     memset(&connection->data[1], 0, 8);
1705     if (uid){
1706         (void)memcpy(&connection->data[1], uid, 8);
1707     }
1708     big_endian_store_16(connection->data, 9, uid_counter);
1709 
1710     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1711     return ERROR_CODE_SUCCESS;
1712 }
1713 
1714 uint8_t avrcp_controller_set_max_num_fragments(uint16_t avrcp_cid, uint8_t max_num_fragments){
1715     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1716     if (!connection){
1717         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1718     }
1719     connection->max_num_fragments = max_num_fragments;
1720     return ERROR_CODE_SUCCESS;
1721 }
1722 
1723 
1724 uint8_t avrcp_controller_send_custom_command(uint16_t avrcp_cid,
1725     avrcp_command_type_t command_type,
1726     avrcp_subunit_type_t subunit_type, avrcp_subunit_id_t subunit_id,
1727     avrcp_pdu_id_t pdu_id, uint32_t company_id,
1728     const uint8_t * data, uint16_t data_len){
1729 
1730     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1731     if (!connection){
1732         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1733     }
1734     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1735 
1736     connection->state = AVCTP_W2_SEND_AVCTP_FRAGMENTED_MESSAGE;
1737     avrcp_custome_command_data_init(connection, AVRCP_CMD_OPCODE_VENDOR_DEPENDENT, command_type, subunit_type, subunit_id, pdu_id, company_id);
1738 
1739     connection->data = (uint8_t *)data;
1740     connection->data_len = data_len;
1741 
1742     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1743     return ERROR_CODE_SUCCESS;
1744 }
1745