xref: /btstack/src/classic/avrcp_target.c (revision a06bcae0f7f63d9d69b2f846d04300ea7058ea66)
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_target.c"
39 
40 #include <stdint.h>
41 #include <stdio.h>
42 #include <stdlib.h>
43 #include <string.h>
44 #include <inttypes.h>
45 
46 #include "btstack.h"
47 #include "classic/avrcp.h"
48 
49 static avrcp_context_t avrcp_target_context;
50 
51 void avrcp_target_create_sdp_record(uint8_t * service, uint32_t service_record_handle, uint8_t browsing, uint16_t supported_features, const char * service_name, const char * service_provider_name){
52     avrcp_create_sdp_record(0, service, service_record_handle, browsing, supported_features, service_name, service_provider_name);
53 }
54 
55 static void avrcp_target_emit_operation(btstack_packet_handler_t callback, uint16_t avrcp_cid, avrcp_operation_id_t operation_id, uint8_t operands_length, uint8_t operand){
56     if (!callback) return;
57     uint8_t event[8];
58     int pos = 0;
59     event[pos++] = HCI_EVENT_AVRCP_META;
60     event[pos++] = sizeof(event) - 2;
61     event[pos++] = AVRCP_SUBEVENT_OPERATION;
62     little_endian_store_16(event, pos, avrcp_cid);
63     pos += 2;
64     event[pos++] = operation_id;
65     event[pos++] = operands_length;
66     event[pos++] = operand;
67     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
68 }
69 
70 static void avrcp_target_emit_respond_query(btstack_packet_handler_t callback, uint16_t avrcp_cid, uint8_t subeventID){
71     if (!callback) return;
72     uint8_t event[5];
73     int pos = 0;
74     event[pos++] = HCI_EVENT_AVRCP_META;
75     event[pos++] = sizeof(event) - 2;
76     event[pos++] = subeventID;
77     little_endian_store_16(event, pos, avrcp_cid);
78     pos += 2;
79     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
80 }
81 
82 static void avrcp_target_emit_respond_subunit_info_query(btstack_packet_handler_t callback, uint16_t avrcp_cid, uint8_t offset){
83     if (!callback) return;
84     uint8_t event[6];
85     int pos = 0;
86     event[pos++] = HCI_EVENT_AVRCP_META;
87     event[pos++] = sizeof(event) - 2;
88     event[pos++] = AVRCP_SUBEVENT_SUBUNIT_INFO_QUERY;
89     little_endian_store_16(event, pos, avrcp_cid);
90     pos += 2;
91     event[pos++] = offset;
92     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
93 }
94 
95 static void avrcp_target_emit_respond_vendor_dependent_query(btstack_packet_handler_t callback, uint16_t avrcp_cid, uint8_t subevent_id){
96     if (!callback) return;
97     uint8_t event[5];
98     int pos = 0;
99     event[pos++] = HCI_EVENT_AVRCP_META;
100     event[pos++] = sizeof(event) - 2;
101     event[pos++] = subevent_id;
102     little_endian_store_16(event, pos, avrcp_cid);
103     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
104 }
105 
106 static uint16_t avrcp_target_pack_single_element_attribute_number(uint8_t * packet, uint16_t size, uint16_t pos, avrcp_media_attribute_id_t attr_id, uint32_t value){
107     UNUSED(size);
108     if ((attr_id < 1) || (attr_id > AVRCP_MEDIA_ATTR_COUNT)) return 0;
109     uint16_t attr_value_length = sprintf((char *)(packet+pos+8), "%0" PRIu32, value);
110     big_endian_store_32(packet, pos, attr_id);
111     pos += 4;
112     big_endian_store_16(packet, pos, UTF8);
113     pos += 2;
114     big_endian_store_16(packet, pos, attr_value_length);
115     pos += 2;
116     return 8 + attr_value_length;
117 }
118 
119 static uint16_t avrcp_target_pack_single_element_attribute_string(uint8_t * packet, uint16_t size, uint16_t pos, rfc2978_charset_mib_enumid_t mib_enumid, avrcp_media_attribute_id_t attr_id, uint8_t * attr_value, uint16_t attr_value_length){
120     UNUSED(size);
121     if (attr_value_length == 0) return 0;
122     if ((attr_id < 1) || (attr_id > AVRCP_MEDIA_ATTR_COUNT)) return 0;
123     big_endian_store_32(packet, pos, attr_id);
124     pos += 4;
125     big_endian_store_16(packet, pos, mib_enumid);
126     pos += 2;
127     big_endian_store_16(packet, pos, attr_value_length);
128     pos += 2;
129     memcpy(packet+pos, attr_value, attr_value_length);
130     pos += attr_value_length;
131     return 8 + attr_value_length;
132 }
133 
134 static int avrcp_target_send_now_playing_info(uint16_t cid, avrcp_connection_t * connection){
135     uint16_t pos = 0;
136     l2cap_reserve_packet_buffer();
137     uint8_t * packet = l2cap_get_outgoing_buffer();
138     uint16_t  size   = l2cap_get_remote_mtu_for_local_cid(connection->l2cap_signaling_cid);
139 
140     packet[pos++] = (connection->transaction_label << 4) | (AVRCP_SINGLE_PACKET << 2) | (AVRCP_RESPONSE_FRAME << 1) | 0;
141     // Profile IDentifier (PID)
142     packet[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL >> 8;
143     packet[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL & 0x00FF;
144 
145     // command_type
146     packet[pos++] = connection->command_type;
147     // subunit_type | subunit ID
148     packet[pos++] = (connection->subunit_type << 3) | connection->subunit_id;
149     // opcode
150     packet[pos++] = (uint8_t)connection->command_opcode;
151 
152     // company id is 3 bytes long
153     big_endian_store_24(packet, pos, BT_SIG_COMPANY_ID);
154     pos += 3;
155 
156     packet[pos++] = AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES;
157     packet[pos++] = 0;
158 
159     // num_attrs
160     int i;
161 
162     uint16_t playing_info_buffer_len = 1;
163     uint16_t playing_info_buffer_len_position = pos;
164 
165     uint8_t  media_attr_count = 0;
166     uint16_t media_attr_count_position = pos + 2;
167     pos += 3;
168 
169     for (i = 0; i < AVRCP_MEDIA_ATTR_COUNT; i++){
170         int attr_id = i+1;
171         int attr_len;
172         switch (attr_id){
173             case AVRCP_MEDIA_ATTR_TRACK:
174                 attr_len = avrcp_target_pack_single_element_attribute_number(packet, size, pos, attr_id, connection->track_nr);
175                 break;
176             case AVRCP_MEDIA_ATTR_TOTAL_TRACKS:
177                 attr_len = avrcp_target_pack_single_element_attribute_number(packet, size, pos, attr_id, connection->total_tracks);
178                 break;
179             case AVRCP_MEDIA_ATTR_SONG_LENGTH:
180                 attr_len = avrcp_target_pack_single_element_attribute_number(packet, size, pos, attr_id, connection->song_length_ms);
181                 break;
182             default:
183                 attr_len = avrcp_target_pack_single_element_attribute_string(packet, size, pos, UTF8, attr_id, connection->now_playing_info[i].value, connection->now_playing_info[i].len);
184                 break;
185         }
186         if (attr_len > 0) {
187             pos += attr_len;
188             playing_info_buffer_len += attr_len;
189             media_attr_count++;
190         }
191     }
192     big_endian_store_16(packet, playing_info_buffer_len_position, playing_info_buffer_len);
193     packet[media_attr_count_position] = media_attr_count;
194 
195     // TODO fragmentation
196     if (playing_info_buffer_len + pos > l2cap_get_remote_mtu_for_local_cid(connection->l2cap_signaling_cid)) {
197         return ERROR_CODE_MEMORY_CAPACITY_EXCEEDED;
198     }
199 
200     connection->wait_to_send = 0;
201     return l2cap_send_prepared(cid, pos);
202 }
203 
204 static int avrcp_target_send_response(uint16_t cid, avrcp_connection_t * connection){
205     int pos = 0;
206     l2cap_reserve_packet_buffer();
207     uint8_t * packet = l2cap_get_outgoing_buffer();
208 
209     // transport header
210     // Transaction label | Packet_type | C/R | IPID (1 == invalid profile identifier)
211     packet[pos++] = (connection->transaction_label << 4) | (AVRCP_SINGLE_PACKET << 2) | (AVRCP_RESPONSE_FRAME << 1) | 0;
212     // Profile IDentifier (PID)
213     packet[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL >> 8;
214     packet[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL & 0x00FF;
215 
216     // command_type
217     packet[pos++] = connection->command_type;
218     // subunit_type | subunit ID
219     packet[pos++] = (connection->subunit_type << 3) | connection->subunit_id;
220     // opcode
221     packet[pos++] = (uint8_t)connection->command_opcode;
222     // operands
223     memcpy(packet+pos, connection->cmd_operands, connection->cmd_operands_length);
224     // printf_hexdump(packet+pos, connection->cmd_operands_length);
225 
226     pos += connection->cmd_operands_length;
227     connection->wait_to_send = 0;
228     return l2cap_send_prepared(cid, pos);
229 }
230 
231 static uint8_t avrcp_target_response_reject(avrcp_connection_t * connection, avrcp_subunit_type_t subunit_type, avrcp_subunit_id_t subunit_id, avrcp_command_opcode_t opcode, avrcp_pdu_id_t pdu_id, avrcp_status_code_t status){
232     // AVRCP_CTYPE_RESPONSE_REJECTED
233     connection->command_type = AVRCP_CTYPE_RESPONSE_REJECTED;
234     connection->subunit_type = subunit_type;
235     connection->subunit_id =   subunit_id;
236     connection->command_opcode = opcode;
237 
238     // company id is 3 bytes long
239     int pos = connection->cmd_operands_length;
240     connection->cmd_operands[pos++] = pdu_id;
241     connection->cmd_operands[pos++] = 0;
242     // param length
243     big_endian_store_16(connection->cmd_operands, pos, 1);
244     pos += 2;
245     connection->cmd_operands[pos++] = status;
246     connection->cmd_operands_length = pos;
247 
248     connection->state = AVCTP_W2_SEND_RESPONSE;
249     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
250     return ERROR_CODE_SUCCESS;
251 }
252 
253 static uint8_t avrcp_target_pass_through_response(uint16_t avrcp_cid, avrcp_command_type_t cmd_type, avrcp_operation_id_t opid, uint8_t operands_length, uint8_t operand){
254     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_target_context);
255     if (!connection){
256         log_error("avrcp_target_operation_reject: could not find a connection.");
257         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
258     }
259     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
260     printf("avrcp_target_pass_through_response: operation 0x%02x, operands length %d\n", opid, operands_length);
261 
262     connection->command_type = cmd_type;
263     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
264     connection->subunit_id =   AVRCP_SUBUNIT_ID;
265     connection->command_opcode = AVRCP_CMD_OPCODE_PASS_THROUGH;
266 
267     int pos = 0;
268     connection->cmd_operands[pos++] = opid;
269     connection->cmd_operands[pos++] = operands_length;
270     if (operands_length == 1){
271         connection->cmd_operands[pos++] = operand;
272     }
273     connection->cmd_operands_length = pos;
274 
275     connection->state = AVCTP_W2_SEND_RESPONSE;
276     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
277     return ERROR_CODE_SUCCESS;
278 }
279 
280 uint8_t avrcp_target_operation_rejected(uint16_t avrcp_cid, avrcp_operation_id_t opid, uint8_t operands_length, uint8_t operand){
281     return avrcp_target_pass_through_response(avrcp_cid, AVRCP_CTYPE_RESPONSE_REJECTED, opid, operands_length, operand);
282 }
283 
284 uint8_t avrcp_target_operation_accepted(uint16_t avrcp_cid, avrcp_operation_id_t opid, uint8_t operands_length, uint8_t operand){
285     return avrcp_target_pass_through_response(avrcp_cid, AVRCP_CTYPE_RESPONSE_ACCEPTED, opid, operands_length, operand);
286 }
287 
288 uint8_t avrcp_target_operation_not_implemented(uint16_t avrcp_cid, avrcp_operation_id_t opid, uint8_t operands_length, uint8_t operand){
289     return avrcp_target_pass_through_response(avrcp_cid, AVRCP_CTYPE_RESPONSE_ACCEPTED, opid, operands_length, operand);
290 }
291 
292 uint8_t avrcp_target_unit_info(uint16_t avrcp_cid, avrcp_subunit_type_t unit_type, uint32_t company_id){
293     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_target_context);
294     if (!connection){
295         log_error("avrcp_unit_info: could not find a connection.");
296         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
297     }
298     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
299 
300     uint8_t unit = 0;
301     connection->command_type = AVRCP_CTYPE_RESPONSE_IMPLEMENTED_STABLE;
302     connection->subunit_type = AVRCP_SUBUNIT_TYPE_UNIT; //vendor unique
303     connection->subunit_id =   AVRCP_SUBUNIT_ID_IGNORE;
304     connection->command_opcode = AVRCP_CMD_OPCODE_UNIT_INFO;
305 
306     connection->cmd_operands_length = 5;
307     connection->cmd_operands[0] = 0x07;
308     connection->cmd_operands[1] = (unit_type << 4) | unit;
309     // company id is 3 bytes long
310     big_endian_store_32(connection->cmd_operands, 2, company_id);
311 
312     connection->state = AVCTP_W2_SEND_RESPONSE;
313     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
314     return ERROR_CODE_SUCCESS;
315 }
316 
317 uint8_t avrcp_target_subunit_info(uint16_t avrcp_cid, avrcp_subunit_type_t subunit_type, uint8_t offset, uint8_t * subunit_info_data){
318     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_target_context);
319     if (!connection){
320         log_error("avrcp_unit_info: could not find a connection.");
321         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
322     }
323     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
324 
325     connection->command_opcode = AVRCP_CMD_OPCODE_SUBUNIT_INFO;
326     connection->command_type = AVRCP_CTYPE_RESPONSE_IMPLEMENTED_STABLE;
327     connection->subunit_type = subunit_type; //vendor unique
328     connection->subunit_id =   AVRCP_SUBUNIT_ID_IGNORE;
329 
330     uint8_t page = offset / 4;
331     uint8_t extension_code = 7;
332     connection->cmd_operands_length = 5;
333     connection->cmd_operands[0] = (page << 4) | extension_code;
334     memcpy(connection->cmd_operands+1, subunit_info_data + offset, 4);
335 
336     connection->state = AVCTP_W2_SEND_RESPONSE;
337     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
338     return ERROR_CODE_SUCCESS;
339 }
340 
341 static inline uint8_t avrcp_prepare_vendor_dependent_response(uint16_t avrcp_cid, avrcp_connection_t ** out_connection, avrcp_pdu_id_t pdu_id, uint16_t param_length){
342     *out_connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_target_context);
343     if (!*out_connection){
344         log_error("avrcp tartget: could not find a connection.");
345         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
346     }
347 
348     if ((*out_connection)->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
349     (*out_connection)->command_opcode  = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
350     (*out_connection)->command_type    = AVRCP_CTYPE_RESPONSE_IMPLEMENTED_STABLE;
351     (*out_connection)->subunit_type    = AVRCP_SUBUNIT_TYPE_PANEL;
352     (*out_connection)->subunit_id      = AVRCP_SUBUNIT_ID;
353 
354     (*out_connection)->cmd_operands[(*out_connection)->cmd_operands_length++] = pdu_id;
355     // reserved
356     (*out_connection)->cmd_operands[(*out_connection)->cmd_operands_length++] = 0;
357     // param length
358     big_endian_store_16((*out_connection)->cmd_operands, (*out_connection)->cmd_operands_length, param_length);
359     (*out_connection)->cmd_operands_length += 2;
360     return ERROR_CODE_SUCCESS;
361 }
362 
363 static uint8_t avrcp_target_capability(uint16_t avrcp_cid, avrcp_capability_id_t capability_id, uint8_t capabilities_num, uint8_t * capabilities, uint8_t size){
364     avrcp_connection_t * connection = NULL;
365     uint8_t status = avrcp_prepare_vendor_dependent_response(avrcp_cid, &connection, AVRCP_PDU_ID_GET_CAPABILITIES, 2+size);
366     if (status != ERROR_CODE_SUCCESS) return status;
367 
368     connection->cmd_operands[connection->cmd_operands_length++] = capability_id;
369     connection->cmd_operands[connection->cmd_operands_length++] = capabilities_num;
370     memcpy(connection->cmd_operands+connection->cmd_operands_length, capabilities, size);
371     connection->cmd_operands_length += size;
372 
373     connection->state = AVCTP_W2_SEND_RESPONSE;
374     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
375     return ERROR_CODE_SUCCESS;
376 }
377 
378 uint8_t avrcp_target_supported_events(uint16_t avrcp_cid, uint8_t capabilities_num, uint8_t * capabilities, uint8_t size){
379     return avrcp_target_capability(avrcp_cid, AVRCP_CAPABILITY_ID_EVENT, capabilities_num, capabilities, size);
380 }
381 
382 uint8_t avrcp_target_supported_companies(uint16_t avrcp_cid, uint8_t capabilities_num, uint8_t * capabilities, uint8_t size ){
383     return avrcp_target_capability(avrcp_cid, AVRCP_CAPABILITY_ID_COMPANY, capabilities_num, capabilities, size);
384 }
385 
386 uint8_t avrcp_target_play_status(uint16_t avrcp_cid, uint32_t song_length_ms, uint32_t song_position_ms, avrcp_play_status_t play_status){
387     avrcp_connection_t * connection = NULL;
388     uint8_t status = avrcp_prepare_vendor_dependent_response(avrcp_cid, &connection, AVRCP_PDU_ID_GET_PLAY_STATUS, 11);
389     if (status != ERROR_CODE_SUCCESS) return status;
390 
391     big_endian_store_32(connection->cmd_operands, connection->cmd_operands_length, song_length_ms);
392     connection->cmd_operands_length += 4;
393     big_endian_store_32(connection->cmd_operands, connection->cmd_operands_length, song_position_ms);
394     connection->cmd_operands_length += 4;
395     connection->cmd_operands[connection->cmd_operands_length++] = play_status;
396 
397     connection->state = AVCTP_W2_SEND_RESPONSE;
398     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
399     return ERROR_CODE_SUCCESS;
400 }
401 
402 uint8_t avrcp_target_now_playing_info(uint16_t avrcp_cid){
403     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_target_context);
404     if (!connection){
405         log_error("avrcp tartget: could not find a connection.");
406         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
407     }
408 
409     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
410     connection->command_opcode  = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
411     connection->command_type    = AVRCP_CTYPE_RESPONSE_IMPLEMENTED_STABLE;
412     connection->subunit_type    = AVRCP_SUBUNIT_TYPE_PANEL;
413     connection->subunit_id      = AVRCP_SUBUNIT_ID;
414 
415     connection->now_playing_info_response = 1;
416     connection->state = AVCTP_W2_SEND_RESPONSE;
417     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
418     return ERROR_CODE_SUCCESS;
419 }
420 
421 static uint8_t avrcp_target_store_media_attr(uint16_t avrcp_cid, avrcp_media_attribute_id_t attr_id, const char * value){
422     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_target_context);
423     if (!connection){
424         log_error("avrcp_unit_info: could not find a connection.");
425         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
426     }
427 
428     int index = attr_id - 1;
429     connection->now_playing_info[index].value = (uint8_t*)value;
430     connection->now_playing_info[index].len   = strlen(value);
431     return ERROR_CODE_SUCCESS;
432 }
433 
434 uint8_t avrcp_target_set_now_playing_title(uint16_t avrcp_cid, const char * title){
435     return avrcp_target_store_media_attr(avrcp_cid, AVRCP_MEDIA_ATTR_TITLE, title);
436 }
437 
438 uint8_t avrcp_target_set_now_playing_artist(uint16_t avrcp_cid, const char * artist){
439     return avrcp_target_store_media_attr(avrcp_cid, AVRCP_MEDIA_ATTR_ARTIST, artist);
440 }
441 
442 uint8_t avrcp_target_set_now_playing_album(uint16_t avrcp_cid, const char * album){
443     return avrcp_target_store_media_attr(avrcp_cid, AVRCP_MEDIA_ATTR_ALBUM, album);
444 }
445 
446 uint8_t avrcp_target_set_now_playing_genre(uint16_t avrcp_cid, const char * genre){
447     return avrcp_target_store_media_attr(avrcp_cid, AVRCP_MEDIA_ATTR_GENRE, genre);
448 }
449 
450 uint8_t avrcp_target_set_now_playing_song_length_ms(uint16_t avrcp_cid, const uint32_t song_length_ms){
451     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_target_context);
452     if (!connection){
453         log_error("avrcp_unit_info: could not find a connection.");
454         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
455     }
456     connection->song_length_ms = song_length_ms;
457     return ERROR_CODE_SUCCESS;
458 }
459 
460 uint8_t avrcp_target_set_now_playing_total_tracks(uint16_t avrcp_cid, const int total_tracks){
461     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_target_context);
462     if (!connection){
463         log_error("avrcp_unit_info: could not find a connection.");
464         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
465     }
466     connection->total_tracks = total_tracks;
467     return ERROR_CODE_SUCCESS;
468 }
469 
470 uint8_t avrcp_target_set_now_playing_track_nr(uint16_t avrcp_cid, const int track_nr){
471     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_target_context);
472     if (!connection){
473         log_error("avrcp_unit_info: could not find a connection.");
474         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
475     }
476     connection->track_nr = track_nr;
477     return ERROR_CODE_SUCCESS;
478 }
479 
480 static uint8_t * avrcp_get_company_id(uint8_t *packet, uint16_t size){
481     UNUSED(size);
482     return packet + 6;
483 }
484 
485 static uint8_t * avrcp_get_pdu(uint8_t *packet, uint16_t size){
486     UNUSED(size);
487     return packet + 9;
488 }
489 
490 static void avrcp_handle_l2cap_data_packet_for_signaling_connection(avrcp_connection_t * connection, uint8_t *packet, uint16_t size){
491     UNUSED(connection);
492     UNUSED(packet);
493     UNUSED(size);
494 
495     // uint8_t opcode;
496 
497     uint8_t transport_header = packet[0];
498     connection->transaction_label = transport_header >> 4;
499     // uint8_t packet_type = (transport_header & 0x0F) >> 2;
500     // uint8_t frame_type = (transport_header & 0x03) >> 1;
501     // uint8_t ipid = transport_header & 0x01;
502     // uint8_t byte_value = packet[2];
503     // uint16_t pid = (byte_value << 8) | packet[2];
504 
505     // avrcp_command_type_t ctype = (avrcp_command_type_t) packet[3];
506     // uint8_t byte_value = packet[4];
507     avrcp_subunit_type_t subunit_type = (avrcp_subunit_type_t) (packet[4] >> 3);
508     avrcp_subunit_id_t   subunit_id   = (avrcp_subunit_id_t) (packet[4] & 0x07);
509     // opcode = packet[pos++];
510 
511     // printf("    Transport header 0x%02x (transaction_label %d, packet_type %d, frame_type %d, ipid %d), pid 0x%4x\n",
512     //     transport_header, transaction_label, packet_type, frame_type, ipid, pid);
513     // printf_hexdump(packet+pos, size-pos);
514 
515     avrcp_command_opcode_t opcode = avrcp_cmd_opcode(packet,size);
516     uint8_t * company_id = avrcp_get_company_id(packet, size);
517     uint8_t * pdu = avrcp_get_pdu(packet, size);
518     // uint16_t param_length = big_endian_read_16(pdu, 2);
519 
520     int pos = 4;
521     uint8_t   pdu_id;
522     connection->cmd_operands_length = 0;
523 
524     switch (opcode){
525         case AVRCP_CMD_OPCODE_UNIT_INFO:
526             avrcp_target_emit_respond_query(avrcp_target_context.avrcp_callback, connection->avrcp_cid, AVRCP_SUBEVENT_UNIT_INFO_QUERY);
527             break;
528         case AVRCP_CMD_OPCODE_SUBUNIT_INFO:{
529             uint8_t offset =  4 * (packet[pos+2]>>4);
530             avrcp_target_emit_respond_subunit_info_query(avrcp_target_context.avrcp_callback, connection->avrcp_cid, offset);
531             break;
532         }
533         case AVRCP_CMD_OPCODE_PASS_THROUGH:
534             log_info("AVRCP_OPERATION_ID 0x%02x, operands length %d, operand %d", packet[6], packet[7], packet[8]);
535             avrcp_target_emit_operation(avrcp_target_context.avrcp_callback, connection->avrcp_cid, packet[6], packet[7], packet[8]);
536             break;
537         case AVRCP_CMD_OPCODE_VENDOR_DEPENDENT:
538             pdu_id = pdu[0];
539             // 1 - reserved
540             // 2-3 param length,
541             memcpy(connection->cmd_operands, company_id, 3);
542             connection->cmd_operands_length = 3;
543             switch (pdu_id){
544                 case AVRCP_PDU_ID_GET_CAPABILITIES:{
545                     avrcp_capability_id_t capability_id = (avrcp_capability_id_t) pdu[pos];
546                     switch (capability_id){
547                         case AVRCP_CAPABILITY_ID_EVENT:
548                             avrcp_target_emit_respond_vendor_dependent_query(avrcp_target_context.avrcp_callback, connection->avrcp_cid, AVRCP_SUBEVENT_EVENT_IDS_QUERY);
549                             break;
550                         case AVRCP_CAPABILITY_ID_COMPANY:
551                             avrcp_target_emit_respond_vendor_dependent_query(avrcp_target_context.avrcp_callback, connection->avrcp_cid, AVRCP_SUBEVENT_COMPANY_IDS_QUERY);
552                             break;
553                         default:
554                             avrcp_target_response_reject(connection, subunit_type, subunit_id, opcode, pdu_id, AVRCP_STATUS_INVALID_PARAMETER);
555                             break;
556                     }
557                     break;
558                 }
559                 case AVRCP_PDU_ID_GET_PLAY_STATUS:
560                     avrcp_target_emit_respond_vendor_dependent_query(avrcp_target_context.avrcp_callback, connection->avrcp_cid, AVRCP_SUBEVENT_PLAY_STATUS_QUERY);
561                     break;
562                 case AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES:{
563                     uint8_t play_identifier[8];
564                     memset(play_identifier, 0, 8);
565                     if (memcmp(pdu+pos, play_identifier, 8) != 0) {
566                         avrcp_target_response_reject(connection, subunit_type, subunit_id, opcode, pdu_id, AVRCP_STATUS_INVALID_PARAMETER);
567                         return;
568                     }
569                     avrcp_target_emit_respond_vendor_dependent_query(avrcp_target_context.avrcp_callback, connection->avrcp_cid, AVRCP_SUBEVENT_NOW_PLAYING_INFO_QUERY);
570                     break;
571                 }
572                 default:
573                     printf("unhandled pdu id 0x%02x\n", pdu_id);
574                     avrcp_target_response_reject(connection, subunit_type, subunit_id, opcode, pdu_id, AVRCP_STATUS_INVALID_COMMAND);
575                     break;
576             }
577             break;
578         default:
579             printf("AVRCP target: opcode 0x%02x not implemented\n", avrcp_cmd_opcode(packet,size));
580             break;
581     }
582 }
583 
584 static void avrcp_controller_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
585     avrcp_connection_t * connection;
586     switch (packet_type) {
587         case L2CAP_DATA_PACKET:
588             connection = get_avrcp_connection_for_l2cap_signaling_cid(channel, &avrcp_target_context);
589             if (!connection) break;
590             avrcp_handle_l2cap_data_packet_for_signaling_connection(connection, packet, size);
591             break;
592         case HCI_EVENT_PACKET:
593             switch (hci_event_packet_get_type(packet)){
594                 case L2CAP_EVENT_CAN_SEND_NOW:
595                     connection = get_avrcp_connection_for_l2cap_signaling_cid(channel, &avrcp_target_context);
596                     if (!connection) break;
597                     switch (connection->state){
598                         case AVCTP_W2_SEND_RESPONSE:
599                             connection->state = AVCTP_CONNECTION_OPENED;
600                             if (connection->now_playing_info_response){
601                                 printf("now_playing_info_response  \n");
602                                 connection->now_playing_info_response = 0;
603                                 avrcp_target_send_now_playing_info(connection->l2cap_signaling_cid, connection);
604                                 break;
605                             }
606                             avrcp_target_send_response(connection->l2cap_signaling_cid, connection);
607                             break;
608                         default:
609                             return;
610                     }
611                     break;
612             default:
613                 avrcp_packet_handler(packet_type, channel, packet, size, &avrcp_target_context);
614                 break;
615         }
616         default:
617             break;
618     }
619 }
620 
621 void avrcp_target_init(void){
622     avrcp_target_context.role = AVRCP_TARGET;
623     avrcp_target_context.connections = NULL;
624     avrcp_target_context.packet_handler = avrcp_controller_packet_handler;
625     l2cap_register_service(&avrcp_controller_packet_handler, BLUETOOTH_PROTOCOL_AVCTP, 0xffff, LEVEL_0);
626 }
627 
628 void avrcp_target_register_packet_handler(btstack_packet_handler_t callback){
629     if (callback == NULL){
630         log_error("avrcp_register_packet_handler called with NULL callback");
631         return;
632     }
633     avrcp_target_context.avrcp_callback = callback;
634 }
635 
636 uint8_t avrcp_target_connect(bd_addr_t bd_addr, uint16_t * avrcp_cid){
637     return avrcp_connect(bd_addr, &avrcp_target_context, avrcp_cid);
638 }
639 
640 uint8_t avrcp_target_disconnect(uint16_t avrcp_cid){
641     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_target_context);
642     if (!connection){
643         log_error("avrcp_get_capabilities: could not find a connection.");
644         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
645     }
646     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
647     l2cap_disconnect(connection->l2cap_signaling_cid, 0);
648     return ERROR_CODE_SUCCESS;
649 }
650 
651