xref: /btstack/src/classic/avrcp_browsing_target.c (revision ef99ca1e18fa86d74ebb7bf7ffc865e3be4f6feb)
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_browsing_target.c"
39 
40 #include <stdint.h>
41 #include <string.h>
42 #include <inttypes.h>
43 #include "classic/avrcp.h"
44 #include "classic/avrcp_browsing.h"
45 #include "classic/avrcp_browsing_target.h"
46 #include "classic/avrcp_target.h"
47 #include "classic/avrcp_controller.h"
48 
49 #include "bluetooth_sdp.h"
50 #include "btstack_debug.h"
51 #include "btstack_event.h"
52 
53 static void avrcp_browsing_target_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
54 
55 static int avrcp_browsing_target_handle_can_send_now(avrcp_browsing_connection_t * connection){
56     int pos = 0;
57 
58     // l2cap_reserve_packet_buffer();
59     // uint8_t * packet = l2cap_get_outgoing_buffer();
60     uint8_t packet[400];
61     connection->packet_type = AVRCP_SINGLE_PACKET;
62 
63     packet[pos++] = (connection->transaction_label << 4) | (connection->packet_type << 2) | (AVRCP_RESPONSE_FRAME << 1) | 0;
64     // Profile IDentifier (PID)
65     packet[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL >> 8;
66     packet[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL & 0x00FF;
67     (void)memcpy(packet + pos, connection->cmd_operands,
68                  connection->cmd_operands_length);
69 
70     pos += connection->cmd_operands_length;
71     connection->wait_to_send = false;
72     // return l2cap_send_prepared(connection->l2cap_browsing_cid, pos);
73     return l2cap_send(connection->l2cap_browsing_cid, packet, pos);
74 }
75 
76 
77 static uint8_t avrcp_browsing_target_response_general_reject(avrcp_browsing_connection_t * connection, avrcp_status_code_t status){
78     // AVRCP_CTYPE_RESPONSE_REJECTED
79     int pos = 0;
80     connection->cmd_operands[pos++] = AVRCP_PDU_ID_GENERAL_REJECT;
81     // connection->message_body[pos++] = 0;
82     // param length
83     big_endian_store_16(connection->cmd_operands, pos, 1);
84     pos += 2;
85     connection->cmd_operands[pos++] = status;
86     connection->cmd_operands_length = 4;
87     connection->state = AVCTP_W2_SEND_RESPONSE;
88     avrcp_browsing_request_can_send_now(connection, connection->l2cap_browsing_cid);
89     return ERROR_CODE_SUCCESS;
90 }
91 
92 static void avrcp_browsing_target_emit_get_folder_items(btstack_packet_handler_t callback, uint16_t browsing_cid, avrcp_browsing_connection_t * connection){
93     btstack_assert(callback != NULL);
94 
95     uint8_t event[18];
96     int pos = 0;
97     event[pos++] = HCI_EVENT_AVRCP_META;
98     event[pos++] = sizeof(event) - 2;
99     event[pos++] = AVRCP_SUBEVENT_BROWSING_GET_FOLDER_ITEMS;
100     little_endian_store_16(event, pos, browsing_cid);
101     pos += 2;
102     event[pos++] = connection->scope;
103     big_endian_store_32(event, pos, connection->start_item);
104     pos += 4;
105     big_endian_store_32(event, pos, connection->end_item);
106     pos += 4;
107     big_endian_store_32(event, pos, connection->attr_bitmap);
108     pos += 4;
109     (*callback)(HCI_EVENT_PACKET, 0, event, pos);
110 }
111 
112 static void avrcp_browsing_target_emit_get_total_num_items(btstack_packet_handler_t callback, uint16_t browsing_cid, avrcp_browsing_connection_t * connection){
113     btstack_assert(callback != NULL);
114 
115     uint8_t event[10];
116     int pos = 0;
117     event[pos++] = HCI_EVENT_AVRCP_META;
118     event[pos++] = sizeof(event) - 2;
119     event[pos++] = AVRCP_SUBEVENT_BROWSING_GET_TOTAL_NUM_ITEMS;
120     little_endian_store_16(event, pos, browsing_cid);
121     pos += 2;
122     event[pos++] = connection->scope;
123     (*callback)(HCI_EVENT_PACKET, 0, event, pos);
124 }
125 
126 static void avrcp_browsing_target_emit_set_browsed_player(btstack_packet_handler_t callback, uint16_t browsing_cid, uint16_t browsed_player_id){
127     btstack_assert(callback != NULL);
128 
129     uint8_t event[10];
130     int pos = 0;
131     event[pos++] = HCI_EVENT_AVRCP_META;
132     event[pos++] = sizeof(event) - 2;
133     event[pos++] = AVRCP_SUBEVENT_BROWSING_SET_BROWSED_PLAYER;
134     little_endian_store_16(event, pos, browsing_cid);
135     pos += 2;
136     little_endian_store_16(event, pos, browsed_player_id);
137     pos += 2;
138     (*callback)(HCI_EVENT_PACKET, 0, event, pos);
139 }
140 
141 static void avrcp_browsing_target_emit_change_path(btstack_packet_handler_t callback, uint16_t browsing_cid, uint16_t uid_counter, avrcp_browsing_direction_t direction, uint8_t * item_id){
142     btstack_assert(callback != NULL);
143 
144     uint8_t event[19];
145     int pos = 0;
146     event[pos++] = HCI_EVENT_AVRCP_META;
147     event[pos++] = sizeof(event) - 2;
148     event[pos++] = AVRCP_SUBEVENT_BROWSING_CHANGE_PATH;
149     little_endian_store_16(event, pos, browsing_cid);
150     pos += 2;
151     little_endian_store_16(event, pos, uid_counter);
152     pos += 2;
153     event[pos++] = direction;
154     memcpy(&event[pos], item_id, 8);
155     pos += 8;
156     (*callback)(HCI_EVENT_PACKET, 0, event, pos);
157 }
158 
159 static void avrcp_browsing_target_emit_get_item_attributes(btstack_packet_handler_t callback, uint16_t browsing_cid, uint16_t uid_counter, uint8_t scope, uint8_t * item_id, uint8_t attr_num, uint8_t * attr_list){
160     btstack_assert(callback != NULL);
161     btstack_assert(attr_num <= AVRCP_MEDIA_ATTR_NUM);
162 
163     uint8_t event[19 + 4 * AVRCP_MEDIA_ATTR_NUM];
164     int pos = 0;
165     event[pos++] = HCI_EVENT_AVRCP_META;
166     event[pos++] = sizeof(event) - 2;
167     event[pos++] = AVRCP_SUBEVENT_BROWSING_GET_ITEM_ATTRIBUTES;
168     little_endian_store_16(event, pos, browsing_cid);
169     pos += 2;
170     little_endian_store_16(event, pos, uid_counter);
171     pos += 2;
172     event[pos++] = scope;
173     memcpy(&event[pos], item_id, 8);
174     pos += 8;
175     uint16_t attr_len = attr_num * 4;
176     little_endian_store_16(event, pos, attr_len);
177     pos += 2;
178 
179     memcpy(&event[pos], attr_list, attr_len);
180     pos += attr_len;
181     (*callback)(HCI_EVENT_PACKET, 0, event, pos);
182 }
183 
184 static void avrcp_browsing_target_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
185     UNUSED(size);
186     avrcp_browsing_connection_t * browsing_connection;
187     avrcp_browsing_direction_t direction;
188     uint16_t uid_counter;
189     uint8_t * item_id;
190 
191     switch (packet_type) {
192         case L2CAP_DATA_PACKET:{
193             browsing_connection = avrcp_get_browsing_connection_for_l2cap_cid_for_role(AVRCP_TARGET, channel);
194             if (!browsing_connection) break;
195             int pos = 0;
196             uint8_t transport_header = packet[pos++];
197             // Transaction label | Packet_type | C/R | IPID (1 == invalid profile identifier)
198             browsing_connection->transaction_label = transport_header >> 4;
199             avctp_packet_type_t avctp_packet_type = (avctp_packet_type_t)((transport_header & 0x0F) >> 2);
200             switch (avctp_packet_type){
201                 case AVCTP_SINGLE_PACKET:
202                 case AVCTP_START_PACKET:
203                     browsing_connection->subunit_type = packet[pos++] >> 2;
204                     browsing_connection->subunit_id = 0;
205                     browsing_connection->command_opcode = packet[pos++];
206                     browsing_connection->num_packets = 1;
207                     if (avctp_packet_type == AVCTP_START_PACKET){
208                         browsing_connection->num_packets = packet[pos++];
209                     }
210                     browsing_connection->pdu_id = packet[pos++];
211                     uint16_t parameter_length = big_endian_read_16(packet, pos);
212                     pos += 2;
213 
214                     switch(browsing_connection->pdu_id){
215                         case AVRCP_PDU_ID_GET_FOLDER_ITEMS:
216                             if (parameter_length < 10){
217                                 avrcp_browsing_target_response_general_reject(browsing_connection, AVRCP_STATUS_INVALID_COMMAND);
218                                 break;
219                             }
220 
221                             browsing_connection->scope = packet[pos++];
222                             browsing_connection->start_item = big_endian_read_32(packet, pos);
223                             pos += 4;
224                             browsing_connection->end_item = big_endian_read_32(packet, pos);
225                             pos += 4;
226                             uint8_t attr_count = packet[pos++];
227                             browsing_connection->attr_bitmap = 0;
228 
229                             while (attr_count){
230                                 uint32_t attr_id = big_endian_read_32(packet, pos);
231                                 pos += 4;
232                                 browsing_connection->attr_bitmap |= (1 << attr_id);
233                                 attr_count--;
234                             }
235                             avrcp_browsing_target_emit_get_folder_items(avrcp_target_context.browsing_avrcp_callback, channel, browsing_connection);
236                             break;
237 
238                         case AVRCP_PDU_ID_GET_TOTAL_NUMBER_OF_ITEMS:{
239                             // send total num items
240                             if (parameter_length != 1){
241                                 avrcp_browsing_target_response_general_reject(browsing_connection, AVRCP_STATUS_INVALID_SCOPE);
242                                 break;
243                             }
244 
245                             browsing_connection->scope = packet[pos++];
246                             avrcp_browsing_target_emit_get_total_num_items(avrcp_target_context.browsing_avrcp_callback, channel, browsing_connection);
247                             break;
248                         }
249                         case AVRCP_PDU_ID_SET_BROWSED_PLAYER:
250                             // player_id (2)
251                             if (parameter_length != 2){
252                                 avrcp_browsing_target_response_general_reject(browsing_connection, AVRCP_STATUS_INVALID_COMMAND);
253                                 break;
254                             }
255                             if ( (pos + 2) > size ){
256                                 avrcp_browsing_target_response_general_reject(browsing_connection, AVRCP_STATUS_INVALID_PLAYER_ID);
257                                 break;
258                             }
259                             avrcp_browsing_target_emit_set_browsed_player(avrcp_target_context.browsing_avrcp_callback, channel, big_endian_read_16(packet, pos));
260                             break;
261 
262                         case AVRCP_PDU_ID_CHANGE_PATH:
263                             // one level up or down in the virtual filesystem
264                             if (parameter_length != 11){
265                                 avrcp_browsing_target_response_general_reject(browsing_connection, AVRCP_STATUS_INVALID_COMMAND);
266                                 break;
267                             }
268                             uid_counter = big_endian_read_16(packet, pos);
269                             pos += 2;
270                             direction = (avrcp_browsing_direction_t)packet[pos++];
271 
272                             if (direction > AVRCP_BROWSING_DIRECTION_FOLDER_RFU){
273                                 avrcp_browsing_target_response_general_reject(browsing_connection, AVRCP_STATUS_INVALID_DIRECTION);
274                                 break;
275                             }
276                             item_id = &packet[pos];
277                             avrcp_browsing_target_emit_change_path(avrcp_target_context.browsing_avrcp_callback, channel, uid_counter, direction, item_id);
278                             break;
279 
280                         case AVRCP_PDU_ID_GET_ITEM_ATTRIBUTES:{
281                             if (parameter_length < 12){
282                                 avrcp_browsing_target_response_general_reject(browsing_connection, AVRCP_STATUS_INVALID_COMMAND);
283                                 break;
284                             }
285 
286                             uint8_t scope = packet[pos++];
287                             item_id = &packet[pos];
288                             pos += 8;
289                             uid_counter = big_endian_read_16(packet, pos);
290                             pos += 2;
291                             uint8_t attr_num = packet[pos++];
292 
293                             uint8_t * attr_list = &packet[pos];
294                             avrcp_browsing_target_emit_get_item_attributes(avrcp_target_context.browsing_avrcp_callback, channel, uid_counter, scope, item_id, attr_num, attr_list);
295                             break;
296                         }
297 
298                         default:
299                             avrcp_browsing_target_response_general_reject(browsing_connection, AVRCP_STATUS_INVALID_COMMAND);
300                             log_info("not parsed pdu ID 0x%02x", browsing_connection->pdu_id);
301                             break;
302                     }
303                     browsing_connection->state = AVCTP_CONNECTION_OPENED;
304                     break;
305 
306                 default:
307                     break;
308             }
309             break;
310         }
311 
312         case HCI_EVENT_PACKET:
313             switch (hci_event_packet_get_type(packet)){
314                 case L2CAP_EVENT_CAN_SEND_NOW:
315                     browsing_connection = avrcp_get_browsing_connection_for_l2cap_cid_for_role(AVRCP_TARGET, channel);
316                     if (browsing_connection->state != AVCTP_W2_SEND_RESPONSE) return;
317                     browsing_connection->state = AVCTP_CONNECTION_OPENED;
318                     avrcp_browsing_target_handle_can_send_now(browsing_connection);
319                     break;
320                 default:
321                     break;
322             }
323             break;
324 
325         default:
326             break;
327     }
328 }
329 
330 void avrcp_browsing_target_init(void){
331     avrcp_target_context.browsing_packet_handler = avrcp_browsing_target_packet_handler;
332     avrcp_browsing_register_target_packet_handler(avrcp_browsing_target_packet_handler);
333 }
334 
335 void avrcp_browsing_target_deinit(void){
336     avrcp_controller_context.browsing_packet_handler = NULL;
337 }
338 
339 void avrcp_browsing_target_register_packet_handler(btstack_packet_handler_t callback){
340     btstack_assert(callback != NULL);
341     avrcp_target_context.browsing_avrcp_callback = callback;
342 }
343 
344 uint8_t avrcp_browsing_target_send_get_folder_items_response(uint16_t avrcp_browsing_cid, uint16_t uid_counter, uint8_t * attr_list, uint16_t attr_list_size, uint16_t num_items){
345     avrcp_connection_t * avrcp_connection = avrcp_get_connection_for_browsing_cid_for_role(AVRCP_TARGET, avrcp_browsing_cid);
346     if (!avrcp_connection){
347         log_error("Could not find an AVRCP Target connection for browsing_cid 0x%02x.", avrcp_browsing_cid);
348         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
349     }
350 
351     avrcp_browsing_connection_t * connection = avrcp_connection->browsing_connection;
352     if (!connection){
353         log_info("Could not find a browsing connection.");
354         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
355     }
356     if (connection->state != AVCTP_CONNECTION_OPENED){
357         return ERROR_CODE_COMMAND_DISALLOWED;
358     }
359 
360     // TODO: handle response to SetAddressedPlayer
361 
362     uint16_t pos = 0;
363     connection->cmd_operands[pos++] = AVRCP_PDU_ID_GET_FOLDER_ITEMS;
364     uint8_t param_length = 5;
365     uint8_t param_length_pos = pos;
366     pos += 2;
367 
368     avrcp_status_code_t status = AVRCP_STATUS_SUCCESS;
369     uint8_t status_pos = pos;
370     pos++;
371 
372     big_endian_store_16(connection->cmd_operands, pos, uid_counter);
373     pos += 2;
374 
375     // TODO: fragmentation
376     if (attr_list_size >  sizeof(connection->cmd_operands)){
377         connection->attr_list = attr_list;
378         connection->attr_list_size = attr_list_size;
379         log_info(" todo: list too big, invoke fragmentation");
380         return 1;
381     }
382 
383     uint16_t items_byte_len = 0;
384     if (connection->start_item < num_items) {
385         if (connection->end_item < num_items) {
386             items_byte_len =  connection->end_item - connection->start_item + 1;
387         } else {
388             items_byte_len = num_items - connection->start_item;
389         }
390 
391     } else {
392         big_endian_store_16(connection->cmd_operands, pos, 0);
393         pos += 2;
394     }
395     big_endian_store_16(connection->cmd_operands, pos, items_byte_len);
396     pos += 2;
397     param_length += items_byte_len;
398 
399     if (items_byte_len > 0){
400         (void)memcpy(&connection->cmd_operands[pos], attr_list, attr_list_size);
401         pos += attr_list_size;
402     } else {
403         status = AVRCP_STATUS_RANGE_OUT_OF_BOUNDS;
404     }
405 
406     big_endian_store_16(connection->cmd_operands, param_length_pos, param_length);
407     connection->cmd_operands[status_pos] = status;
408 
409     btstack_assert(pos <= 400);
410     connection->cmd_operands_length = pos;
411 
412     connection->state = AVCTP_W2_SEND_RESPONSE;
413     avrcp_browsing_request_can_send_now(connection, connection->l2cap_browsing_cid);
414     return ERROR_CODE_SUCCESS;
415 }
416 
417 uint8_t avrcp_browsing_target_send_change_path_response(uint16_t avrcp_browsing_cid, uint16_t uid_counter, avrcp_status_code_t status, uint32_t num_items){
418     avrcp_connection_t * avrcp_connection = avrcp_get_connection_for_browsing_cid_for_role(AVRCP_TARGET, avrcp_browsing_cid);
419     if (!avrcp_connection){
420         log_error("Could not find an AVRCP Target connection for browsing_cid 0x%02x.", avrcp_browsing_cid);
421         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
422     }
423 
424     avrcp_browsing_connection_t * connection = avrcp_connection->browsing_connection;
425     if (!connection){
426         log_info("Could not find a browsing connection.");
427         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
428     }
429     if (connection->state != AVCTP_CONNECTION_OPENED){
430         return ERROR_CODE_COMMAND_DISALLOWED;
431     }
432 
433     uint16_t pos = 0;
434     connection->cmd_operands[pos++] = AVRCP_PDU_ID_CHANGE_PATH;
435     // Param length
436     big_endian_store_16(connection->cmd_operands, pos, 5);
437     pos += 2;
438     connection->cmd_operands[pos++] = status;
439     big_endian_store_32(connection->cmd_operands, pos, num_items);
440     pos += 4;
441 
442     connection->cmd_operands_length = pos;
443     connection->state = AVCTP_W2_SEND_RESPONSE;
444     avrcp_browsing_request_can_send_now(connection, connection->l2cap_browsing_cid);
445     return ERROR_CODE_SUCCESS;
446 }
447 
448 uint8_t avrcp_browsing_target_send_get_item_attributes_response(uint16_t avrcp_browsing_cid, avrcp_status_code_t status, uint8_t * attr_list, uint16_t attr_list_size, uint8_t num_items){
449     avrcp_connection_t * avrcp_connection = avrcp_get_connection_for_browsing_cid_for_role(AVRCP_TARGET, avrcp_browsing_cid);
450     if (!avrcp_connection){
451         log_error("Could not find an AVRCP Target connection for browsing_cid 0x%02x.", avrcp_browsing_cid);
452         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
453     }
454 
455     avrcp_browsing_connection_t * connection = avrcp_connection->browsing_connection;
456     if (!connection){
457         log_info("Could not find a browsing connection.");
458         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
459     }
460     if (connection->state != AVCTP_CONNECTION_OPENED){
461         return ERROR_CODE_COMMAND_DISALLOWED;
462     }
463 
464     // TODO: fragmentation
465     if (attr_list_size >  (sizeof(connection->cmd_operands) - 5)){
466         connection->attr_list = attr_list;
467         connection->attr_list_size = attr_list_size;
468         log_info(" todo: list too big, invoke fragmentation");
469         return 1;
470     }
471 
472     uint16_t pos = 0;
473     connection->cmd_operands[pos++] = AVRCP_PDU_ID_GET_ITEM_ATTRIBUTES;
474 
475     uint8_t param_length_pos = pos;
476     big_endian_store_16(connection->cmd_operands, pos, 1);
477     pos += 2;
478     connection->cmd_operands[pos++] = status;
479 
480     if (status != AVRCP_STATUS_SUCCESS){
481         connection->cmd_operands_length = pos;
482         connection->state = AVCTP_W2_SEND_RESPONSE;
483         avrcp_browsing_request_can_send_now(connection, connection->l2cap_browsing_cid);
484         return ERROR_CODE_SUCCESS;
485     }
486 
487     connection->cmd_operands[pos++] = num_items;
488     (void)memcpy(&connection->cmd_operands[pos], attr_list, attr_list_size);
489     pos += attr_list_size;
490 
491     big_endian_store_16(connection->cmd_operands, param_length_pos, pos - 3);
492     connection->cmd_operands_length = pos;
493     connection->state = AVCTP_W2_SEND_RESPONSE;
494     avrcp_browsing_request_can_send_now(connection, connection->l2cap_browsing_cid);
495     return ERROR_CODE_SUCCESS;
496 }
497 
498 uint8_t avrcp_browsing_target_send_accept_set_browsed_player(uint16_t avrcp_browsing_cid, uint16_t uid_counter, uint16_t browsed_player_id, uint8_t * response, uint16_t response_size){
499     avrcp_connection_t * avrcp_connection = avrcp_get_connection_for_browsing_cid_for_role(AVRCP_TARGET, avrcp_browsing_cid);
500     if (!avrcp_connection){
501         log_error("Could not find an AVRCP Target connection for browsing_cid 0x%02x.", avrcp_browsing_cid);
502         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
503     }
504 
505     avrcp_browsing_connection_t * connection = avrcp_connection->browsing_connection;
506     if (!connection){
507         log_info("Could not find a browsing connection.");
508         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
509     }
510 
511     if (connection->state != AVCTP_CONNECTION_OPENED) {
512         log_info("Browsing connection wrong state.");
513         return ERROR_CODE_COMMAND_DISALLOWED;
514     }
515 
516     connection->browsed_player_id = browsed_player_id;
517 
518     uint16_t pos = 0;
519     connection->cmd_operands[pos++] = AVRCP_PDU_ID_SET_BROWSED_PLAYER;
520     big_endian_store_16(connection->cmd_operands, pos, response_size + 2 + 1); // uuid counter + status
521     pos += 2;
522 
523     connection->cmd_operands[pos++] = AVRCP_STATUS_SUCCESS;
524     big_endian_store_16(connection->cmd_operands, pos, uid_counter);
525     pos += 2;
526 
527     // TODO: fragmentation
528     if (response_size >  sizeof(connection->cmd_operands)){
529         connection->attr_list = response;
530         connection->attr_list_size = response_size;
531         log_info(" todo: list too big, invoke fragmentation");
532         return 1;
533     }
534 
535     (void)memcpy(&connection->cmd_operands[pos], response, response_size);
536     pos += response_size;
537 	btstack_assert(pos <= 255);
538     connection->cmd_operands_length = (uint8_t) pos;
539 
540     connection->state = AVCTP_W2_SEND_RESPONSE;
541     avrcp_browsing_request_can_send_now(connection, connection->l2cap_browsing_cid);
542     return ERROR_CODE_SUCCESS;
543 }
544 
545 uint8_t avrcp_browsing_target_send_reject_set_browsed_player(uint16_t avrcp_browsing_cid, avrcp_status_code_t status){
546     avrcp_connection_t * avrcp_connection = avrcp_get_connection_for_browsing_cid_for_role(AVRCP_TARGET, avrcp_browsing_cid);
547     if (!avrcp_connection){
548         log_error("Could not find an AVRCP Target connection for browsing_cid 0x%02x.", avrcp_browsing_cid);
549         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
550     }
551 
552     avrcp_browsing_connection_t * connection = avrcp_connection->browsing_connection;
553     if (!connection){
554         log_info("Could not find a browsing connection.");
555         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
556     }
557 
558     if (connection->state != AVCTP_CONNECTION_OPENED) {
559         log_info("Browsing connection wrong state.");
560         return ERROR_CODE_COMMAND_DISALLOWED;
561     }
562 
563     int pos = 0;
564     connection->cmd_operands[pos++] = AVRCP_PDU_ID_SET_BROWSED_PLAYER;
565     big_endian_store_16(connection->cmd_operands, pos, 1);
566     pos += 2;
567     connection->cmd_operands[pos++] = status;
568     connection->cmd_operands_length = pos;
569 
570     connection->state = AVCTP_W2_SEND_RESPONSE;
571     avrcp_browsing_request_can_send_now(connection, connection->l2cap_browsing_cid);
572     return ERROR_CODE_SUCCESS;
573 }
574 
575 uint8_t avrcp_browsing_target_send_get_total_num_items_response(uint16_t avrcp_browsing_cid, uint16_t uid_counter, uint32_t total_num_items){
576     avrcp_connection_t * avrcp_connection = avrcp_get_connection_for_browsing_cid_for_role(AVRCP_TARGET, avrcp_browsing_cid);
577     if (!avrcp_connection){
578         log_error("Could not find an AVRCP Target connection for browsing_cid 0x%02x.", avrcp_browsing_cid);
579         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
580     }
581 
582     avrcp_browsing_connection_t * connection = avrcp_connection->browsing_connection;
583     if (!connection){
584         log_info("Could not find a browsing connection.");
585         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
586     }
587 
588     if (connection->state != AVCTP_CONNECTION_OPENED) {
589         log_info("Browsing connection wrong state.");
590         return ERROR_CODE_COMMAND_DISALLOWED;
591     }
592 
593     int pos = 0;
594     connection->cmd_operands[pos++] = AVRCP_PDU_ID_GET_TOTAL_NUMBER_OF_ITEMS;
595     big_endian_store_16(connection->cmd_operands, pos, 7);
596     pos += 2;
597     connection->cmd_operands[pos++] = AVRCP_STATUS_SUCCESS;
598     big_endian_store_16(connection->cmd_operands, pos, uid_counter);
599     pos += 2;
600     big_endian_store_32(connection->cmd_operands, pos, total_num_items);
601     pos += 4;
602     connection->cmd_operands_length = pos;
603 
604     connection->state = AVCTP_W2_SEND_RESPONSE;
605     avrcp_browsing_request_can_send_now(connection, connection->l2cap_browsing_cid);
606     return ERROR_CODE_SUCCESS;
607 }
608 
609