xref: /btstack/src/classic/avrcp_browsing_controller.c (revision 881a49d59a07b24d6e642b29c1b67e7e92358514)
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_browsing_controller.c"
39 
40 #include <stdint.h>
41 #include <stdio.h>
42 #include <stdlib.h>
43 #include <string.h>
44 #include <inttypes.h>
45 #include "btstack.h"
46 #include "classic/avrcp.h"
47 #include "classic/avrcp_browsing_controller.h"
48 
49 #define PSM_AVCTP_BROWSING              0x001b
50 
51 static void avrcp_browser_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size, avrcp_context_t * context);
52 static void avrcp_browsing_controller_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
53 
54 static avrcp_connection_t * get_avrcp_connection_for_browsing_cid(uint16_t browsing_cid, avrcp_context_t * context){
55     btstack_linked_list_iterator_t it;
56     btstack_linked_list_iterator_init(&it, (btstack_linked_list_t *)  &context->connections);
57     while (btstack_linked_list_iterator_has_next(&it)){
58         avrcp_connection_t * connection = (avrcp_connection_t *)btstack_linked_list_iterator_next(&it);
59         if (connection->avrcp_browsing_cid != browsing_cid) continue;
60         return connection;
61     }
62     return NULL;
63 }
64 
65 static avrcp_connection_t * get_avrcp_connection_for_browsing_l2cap_cid(uint16_t browsing_l2cap_cid, avrcp_context_t * context){
66     btstack_linked_list_iterator_t it;
67     btstack_linked_list_iterator_init(&it, (btstack_linked_list_t *)  &context->connections);
68     while (btstack_linked_list_iterator_has_next(&it)){
69         avrcp_connection_t * connection = (avrcp_connection_t *)btstack_linked_list_iterator_next(&it);
70         if (connection->browsing_connection &&  connection->browsing_connection->l2cap_browsing_cid != browsing_l2cap_cid) continue;
71         return connection;
72     }
73     return NULL;
74 }
75 
76 static avrcp_browsing_connection_t * get_avrcp_browsing_connection_for_l2cap_cid(uint16_t l2cap_cid, avrcp_context_t * context){
77     btstack_linked_list_iterator_t it;
78     btstack_linked_list_iterator_init(&it, (btstack_linked_list_t *)  &context->connections);
79     while (btstack_linked_list_iterator_has_next(&it)){
80         avrcp_connection_t * connection = (avrcp_connection_t *)btstack_linked_list_iterator_next(&it);
81         if (connection->browsing_connection && connection->browsing_connection->l2cap_browsing_cid != l2cap_cid) continue;
82         return connection->browsing_connection;
83     }
84     return NULL;
85 }
86 
87 static void avrcp_emit_browsing_connection_established(btstack_packet_handler_t callback, uint16_t browsing_cid, bd_addr_t addr, uint8_t status){
88     if (!callback) return;
89     uint8_t event[12];
90     int pos = 0;
91     event[pos++] = HCI_EVENT_AVRCP_META;
92     event[pos++] = sizeof(event) - 2;
93     event[pos++] = AVRCP_SUBEVENT_BROWSING_CONNECTION_ESTABLISHED;
94     event[pos++] = status;
95     reverse_bd_addr(addr,&event[pos]);
96     pos += 6;
97     little_endian_store_16(event, pos, browsing_cid);
98     pos += 2;
99     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
100 }
101 
102 static void avrcp_emit_incoming_browsing_connection(btstack_packet_handler_t callback, uint16_t browsing_cid, bd_addr_t addr){
103     if (!callback) return;
104     uint8_t event[11];
105     int pos = 0;
106     event[pos++] = HCI_EVENT_AVRCP_META;
107     event[pos++] = sizeof(event) - 2;
108     event[pos++] = AVRCP_SUBEVENT_INCOMING_BROWSING_CONNECTION;
109     reverse_bd_addr(addr,&event[pos]);
110     pos += 6;
111     little_endian_store_16(event, pos, browsing_cid);
112     pos += 2;
113     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
114 }
115 
116 static void avrcp_emit_browsing_connection_closed(btstack_packet_handler_t callback, uint16_t browsing_cid){
117     if (!callback) return;
118     uint8_t event[5];
119     int pos = 0;
120     event[pos++] = HCI_EVENT_AVRCP_META;
121     event[pos++] = sizeof(event) - 2;
122     event[pos++] = AVRCP_SUBEVENT_BROWSING_CONNECTION_RELEASED;
123     little_endian_store_16(event, pos, browsing_cid);
124     pos += 2;
125     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
126 }
127 
128 static avrcp_browsing_connection_t * avrcp_browsing_create_connection(avrcp_connection_t * avrcp_connection){
129     avrcp_browsing_connection_t * connection = btstack_memory_avrcp_browsing_connection_get();
130     memset(connection, 0, sizeof(avrcp_browsing_connection_t));
131     connection->state = AVCTP_CONNECTION_IDLE;
132     connection->transaction_label = 0xFF;
133     avrcp_connection->avrcp_browsing_cid = avrcp_get_next_cid();
134     avrcp_connection->browsing_connection = connection;
135     return connection;
136 }
137 
138 static uint8_t avrcp_browsing_connect(bd_addr_t remote_addr, avrcp_context_t * context, uint8_t * ertm_buffer, uint32_t size, l2cap_ertm_config_t * ertm_config, uint16_t * browsing_cid){
139     avrcp_connection_t * avrcp_connection = get_avrcp_connection_for_bd_addr(remote_addr, context);
140 
141     if (!avrcp_connection){
142         log_error("avrcp: there is no previously established AVRCP controller connection.");
143         return ERROR_CODE_COMMAND_DISALLOWED;
144     }
145 
146     avrcp_browsing_connection_t * connection = avrcp_connection->browsing_connection;
147     if (connection){
148         log_error(" avrcp_browsing_connect connection exists.");
149         return ERROR_CODE_SUCCESS;
150     }
151 
152     connection = avrcp_browsing_create_connection(avrcp_connection);
153     if (!connection){
154         log_error("avrcp: could not allocate connection struct.");
155         return BTSTACK_MEMORY_ALLOC_FAILED;
156     }
157 
158     if (!browsing_cid) return L2CAP_LOCAL_CID_DOES_NOT_EXIST;
159 
160     *browsing_cid = avrcp_connection->avrcp_browsing_cid;
161     connection->ertm_buffer = ertm_buffer;
162     connection->ertm_buffer_size = size;
163     avrcp_connection->browsing_connection = connection;
164 
165     memcpy(&connection->ertm_config, ertm_config, sizeof(l2cap_ertm_config_t));
166 
167     return l2cap_create_ertm_channel(avrcp_browsing_controller_packet_handler, remote_addr, avrcp_connection->browsing_l2cap_psm,
168                     &connection->ertm_config, connection->ertm_buffer, connection->ertm_buffer_size, NULL);
169 
170 }
171 
172 static void avrcp_browser_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size, avrcp_context_t * context){
173     UNUSED(channel);
174     UNUSED(size);
175     bd_addr_t event_addr;
176     uint16_t local_cid;
177     uint8_t  status;
178     avrcp_browsing_connection_t * browsing_connection = NULL;
179     avrcp_connection_t * avrcp_connection = NULL;
180 
181     if (packet_type != HCI_EVENT_PACKET) return;
182 
183     switch (hci_event_packet_get_type(packet)) {
184         case HCI_EVENT_DISCONNECTION_COMPLETE:
185             avrcp_emit_browsing_connection_closed(context->browsing_avrcp_callback, 0);
186             break;
187         case L2CAP_EVENT_INCOMING_CONNECTION:
188             l2cap_event_incoming_connection_get_address(packet, event_addr);
189             local_cid = l2cap_event_incoming_connection_get_local_cid(packet);
190             avrcp_connection = get_avrcp_connection_for_bd_addr(event_addr, context);
191             if (!avrcp_connection) {
192                 log_error("No previously created AVRCP controller connections");
193                 l2cap_decline_connection(local_cid);
194                 break;
195             }
196             browsing_connection = avrcp_browsing_create_connection(avrcp_connection);
197             browsing_connection->l2cap_browsing_cid = local_cid;
198             browsing_connection->state = AVCTP_CONNECTION_W4_ERTM_CONFIGURATION;
199             log_info("Emit AVRCP_SUBEVENT_INCOMING_BROWSING_CONNECTION browsing_cid 0x%02x, l2cap_signaling_cid 0x%02x\n", avrcp_connection->avrcp_browsing_cid, browsing_connection->l2cap_browsing_cid);
200             avrcp_emit_incoming_browsing_connection(context->browsing_avrcp_callback, avrcp_connection->avrcp_browsing_cid, event_addr);
201             break;
202 
203         case L2CAP_EVENT_CHANNEL_OPENED:
204             l2cap_event_channel_opened_get_address(packet, event_addr);
205             status = l2cap_event_channel_opened_get_status(packet);
206             local_cid = l2cap_event_channel_opened_get_local_cid(packet);
207 
208             avrcp_connection = get_avrcp_connection_for_bd_addr(event_addr, context);
209             if (!avrcp_connection){
210                 log_error("Failed to find AVRCP connection for bd_addr %s", bd_addr_to_str(event_addr));
211                 avrcp_emit_browsing_connection_established(context->browsing_avrcp_callback, local_cid, event_addr, L2CAP_LOCAL_CID_DOES_NOT_EXIST);
212                 l2cap_disconnect(local_cid, 0); // reason isn't used
213                 break;
214             }
215 
216             browsing_connection = avrcp_connection->browsing_connection;
217             if (status != ERROR_CODE_SUCCESS){
218                 log_info("L2CAP connection to connection %s failed. status code 0x%02x", bd_addr_to_str(event_addr), status);
219                 avrcp_emit_browsing_connection_established(context->browsing_avrcp_callback, avrcp_connection->avrcp_browsing_cid, event_addr, status);
220                 btstack_memory_avrcp_browsing_connection_free(browsing_connection);
221                 avrcp_connection->browsing_connection = NULL;
222                 break;
223             }
224             if (browsing_connection->state != AVCTP_CONNECTION_W4_L2CAP_CONNECTED) break;
225 
226             browsing_connection->l2cap_browsing_cid = local_cid;
227 
228             log_info("L2CAP_EVENT_CHANNEL_OPENED browsing cid 0x%02x, l2cap cid 0x%02x", avrcp_connection->avrcp_browsing_cid, browsing_connection->l2cap_browsing_cid);
229             browsing_connection->state = AVCTP_CONNECTION_OPENED;
230             avrcp_emit_browsing_connection_established(context->browsing_avrcp_callback, avrcp_connection->avrcp_browsing_cid, event_addr, ERROR_CODE_SUCCESS);
231             break;
232 
233         case L2CAP_EVENT_CHANNEL_CLOSED:
234             // data: event (8), len(8), channel (16)
235             local_cid = l2cap_event_channel_closed_get_local_cid(packet);
236             avrcp_connection = get_avrcp_connection_for_browsing_l2cap_cid(local_cid, context);
237 
238             if (avrcp_connection && avrcp_connection->browsing_connection){
239                 avrcp_emit_browsing_connection_closed(context->browsing_avrcp_callback, avrcp_connection->avrcp_browsing_cid);
240                 // free connection
241                 btstack_memory_avrcp_browsing_connection_free(avrcp_connection->browsing_connection);
242                 avrcp_connection->browsing_connection = NULL;
243                 break;
244             }
245             break;
246         default:
247             break;
248     }
249 }
250 
251 static int avrcp_browsing_controller_send_get_folder_items_cmd(uint16_t cid, avrcp_browsing_connection_t * connection){
252     uint8_t command[100];
253     int pos = 0;
254 
255     // // if (connection->cmd_operands[3] == AVRCP_PDU_ID_GET_CAPABILITIES){
256     //     printf("cheet\n");
257     //     uint8_t buffer[] = {0xB0, 0x11, 0x0E, 0xFF, 0x00, 0x02, 0xFF, 0xFF};
258     //     memcpy(command, buffer, sizeof(buffer));
259     //     pos =  sizeof(buffer);
260     //     return l2cap_send(cid, command, pos);
261     // // }
262 
263     // transport header
264     // Transaction label | Packet_type | C/R | IPID (1 == invalid profile identifier)
265     command[pos++] = (connection->transaction_label << 4) | (AVRCP_SINGLE_PACKET << 2) | (AVRCP_COMMAND_FRAME << 1) | 0;
266     // Profile IDentifier (PID)
267     command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL >> 8;
268     command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL & 0x00FF;
269     command[pos++] = AVRCP_PDU_ID_GET_FOLDER_ITEMS;
270 
271     uint32_t attribute_count = 0;
272     uint32_t attributes_to_copy = 0;
273 
274     switch (connection->attr_bitmap){
275         case AVRCP_MEDIA_ATTR_NONE:
276             attribute_count = AVRCP_MEDIA_ATTR_NONE; // 0xFFFFFFFF
277             break;
278         case AVRCP_MEDIA_ATTR_ALL:
279             attribute_count = AVRCP_MEDIA_ATTR_ALL;  // 0
280             break;
281         default:
282             attribute_count = count_set_bits_uint32(connection->attr_bitmap & 0xff);
283             attributes_to_copy = attribute_count;
284             break;
285     }
286 
287     big_endian_store_16(command, pos, 9 + attribute_count*4);
288     pos += 2;
289     command[pos++] = connection->scope;
290     big_endian_store_32(command, pos, connection->start_item);
291     pos += 4;
292     big_endian_store_32(command, pos, connection->end_item);
293     pos += 4;
294     command[pos++] = attribute_count;
295 
296     int bit_position = 1;
297     while (attributes_to_copy){
298         if (connection->attr_bitmap & (1 << bit_position)){
299             big_endian_store_32(command, pos, bit_position);
300             pos += 4;
301             attributes_to_copy--;
302         }
303         bit_position++;
304     }
305 
306 
307     return l2cap_send(cid, command, pos);
308 }
309 
310 
311 static int avrcp_browsing_controller_send_get_item_attributes_cmd(uint16_t cid, avrcp_browsing_connection_t * connection){
312     uint8_t command[100];
313     int pos = 0;
314     // transport header
315     // Transaction label | Packet_type | C/R | IPID (1 == invalid profile identifier)
316     command[pos++] = (connection->transaction_label << 4) | (AVRCP_SINGLE_PACKET << 2) | (AVRCP_COMMAND_FRAME << 1) | 0;
317     // Profile IDentifier (PID)
318     command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL >> 8;
319     command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL & 0x00FF;
320     command[pos++] = AVRCP_PDU_ID_GET_ITEM_ATTRIBUTES;
321 
322     uint32_t attribute_count = 0;
323     uint32_t attributes_to_copy = 0;
324 
325     switch (connection->attr_bitmap){
326         case AVRCP_MEDIA_ATTR_NONE:
327             attribute_count = AVRCP_MEDIA_ATTR_NONE; // 0xFFFFFFFF
328             break;
329         case AVRCP_MEDIA_ATTR_ALL:
330             attribute_count = AVRCP_MEDIA_ATTR_ALL;  // 0
331             break;
332         default:
333             attribute_count = count_set_bits_uint32(connection->attr_bitmap & 0xff);
334             attributes_to_copy = attribute_count;
335             break;
336     }
337 
338     big_endian_store_16(command, pos, 12 + attribute_count*4);
339     pos += 2;
340 
341     command[pos++] = connection->scope;
342     memcpy(command+pos, connection->folder_uid, 8);
343     pos += 8;
344     big_endian_store_16(command, pos, connection->uid_counter);
345     pos += 2;
346     command[pos++] = attribute_count;
347 
348     int bit_position = 1;
349     while (attributes_to_copy){
350         if (connection->attr_bitmap & (1 << bit_position)){
351             big_endian_store_32(command, pos, bit_position);
352             pos += 4;
353             attributes_to_copy--;
354         }
355         bit_position++;
356     }
357 
358     return l2cap_send(cid, command, pos);
359 }
360 
361 
362 static int avrcp_browsing_controller_send_change_path_cmd(uint16_t cid, avrcp_browsing_connection_t * connection){
363     uint8_t command[100];
364     int pos = 0;
365     // transport header
366     // Transaction label | Packet_type | C/R | IPID (1 == invalid profile identifier)
367     command[pos++] = (connection->transaction_label << 4) | (AVRCP_SINGLE_PACKET << 2) | (AVRCP_COMMAND_FRAME << 1) | 0;
368     // Profile IDentifier (PID)
369     command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL >> 8;
370     command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL & 0x00FF;
371     command[pos++] = AVRCP_PDU_ID_CHANGE_PATH;
372 
373     big_endian_store_16(command, pos, 11);
374     pos += 2;
375     pos += 2;
376     command[pos++] = connection->direction;
377     memcpy(command+pos, connection->folder_uid, 8);
378     pos += 8;
379     return l2cap_send(cid, command, pos);
380 }
381 
382 static int avrcp_browsing_controller_send_search_cmd(uint16_t cid, avrcp_browsing_connection_t * connection){
383     uint8_t command[100];
384     int pos = 0;
385     // transport header
386     // Transaction label | Packet_type | C/R | IPID (1 == invalid profile identifier)
387     command[pos++] = (connection->transaction_label << 4) | (AVRCP_SINGLE_PACKET << 2) | (AVRCP_COMMAND_FRAME << 1) | 0;
388     // Profile IDentifier (PID)
389     command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL >> 8;
390     command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL & 0x00FF;
391     command[pos++] = AVRCP_PDU_ID_SEARCH;
392 
393     big_endian_store_16(command, pos, 4 + connection->search_str_len);
394     pos += 2;
395 
396     big_endian_store_16(command, pos, 0x006A);
397     pos += 2;
398     big_endian_store_16(command, pos, connection->search_str_len);
399     pos += 2;
400 
401     memcpy(command+pos,connection->search_str, connection->search_str_len);
402     pos += connection->search_str_len;
403     return l2cap_send(cid, command, pos);
404 }
405 
406 static int avrcp_browsing_controller_send_set_browsed_player_cmd(uint16_t cid, avrcp_browsing_connection_t * connection){
407     uint8_t command[100];
408     int pos = 0;
409     // transport header
410     // Transaction label | Packet_type | C/R | IPID (1 == invalid profile identifier)
411     command[pos++] = (connection->transaction_label << 4) | (AVRCP_SINGLE_PACKET << 2) | (AVRCP_COMMAND_FRAME << 1) | 0;
412     // Profile IDentifier (PID)
413     command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL >> 8;
414     command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL & 0x00FF;
415     command[pos++] = AVRCP_PDU_ID_SET_BROWSED_PLAYER;
416 
417     big_endian_store_16(command, pos, 2);
418     pos += 2;
419     big_endian_store_16(command, pos, connection->browsed_player_id);
420     pos += 2;
421     return l2cap_send(cid, command, pos);
422 }
423 
424 static int avrcp_browsing_controller_send_get_total_nr_items_cmd(uint16_t cid, avrcp_browsing_connection_t * connection){
425     uint8_t command[7];
426     int pos = 0;
427     // transport header
428     // Transaction label | Packet_type | C/R | IPID (1 == invalid profile identifier)
429     command[pos++] = (connection->transaction_label << 4) | (AVRCP_SINGLE_PACKET << 2) | (AVRCP_COMMAND_FRAME << 1) | 0;
430     // Profile IDentifier (PID)
431     command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL >> 8;
432     command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL & 0x00FF;
433     command[pos++] = AVRCP_PDU_ID_GET_TOTAL_NUMBER_OF_ITEMS;
434 
435     big_endian_store_16(command, pos, 1);
436     pos += 2;
437     command[pos++] = connection->get_total_nr_items_scope;
438     return l2cap_send(cid, command, pos);
439 }
440 
441 static void avrcp_browsing_controller_handle_can_send_now(avrcp_browsing_connection_t * connection){
442     switch (connection->state){
443         case AVCTP_CONNECTION_OPENED:
444             if (connection->set_browsed_player_id){
445                 connection->state = AVCTP_W2_RECEIVE_RESPONSE;
446                 connection->set_browsed_player_id = 0;
447                 avrcp_browsing_controller_send_set_browsed_player_cmd(connection->l2cap_browsing_cid, connection);
448                 break;
449             }
450 
451             if (connection->get_total_nr_items){
452                 connection->state = AVCTP_W2_RECEIVE_RESPONSE;
453                 connection->get_total_nr_items = 0;
454                 avrcp_browsing_controller_send_get_total_nr_items_cmd(connection->l2cap_browsing_cid, connection);
455                 break;
456             }
457 
458             if (connection->get_folder_items){
459                 connection->state = AVCTP_W2_RECEIVE_RESPONSE;
460                 connection->get_folder_items = 0;
461                 avrcp_browsing_controller_send_get_folder_items_cmd(connection->l2cap_browsing_cid, connection);
462                 break;
463             }
464 
465             if (connection->get_item_attributes){
466                 connection->state = AVCTP_W2_RECEIVE_RESPONSE;
467                 connection->get_item_attributes = 0;
468                 avrcp_browsing_controller_send_get_item_attributes_cmd(connection->l2cap_browsing_cid, connection);
469                 break;
470             }
471 
472             if (connection->change_path){
473                 connection->state = AVCTP_W2_RECEIVE_RESPONSE;
474                 connection->change_path = 0;
475                 avrcp_browsing_controller_send_change_path_cmd(connection->l2cap_browsing_cid, connection);
476                 break;
477             }
478 
479             if (connection->search){
480                 connection->state = AVCTP_W2_RECEIVE_RESPONSE;
481                 connection->search = 0;
482                 avrcp_browsing_controller_send_search_cmd(connection->l2cap_browsing_cid, connection);
483                 break;
484             }
485             break;
486         default:
487             return;
488     }
489 }
490 
491 
492 static void avrcp_browsing_controller_emit_done_with_uid_counter(btstack_packet_handler_t callback, uint16_t browsing_cid, uint16_t uid_counter, uint8_t browsing_status, uint8_t bluetooth_status){
493     if (!callback) return;
494     uint8_t event[9];
495     int pos = 0;
496     event[pos++] = HCI_EVENT_AVRCP_META;
497     event[pos++] = sizeof(event) - 2;
498     event[pos++] = AVRCP_SUBEVENT_BROWSING_DONE;
499     little_endian_store_16(event, pos, browsing_cid);
500     pos += 2;
501     little_endian_store_16(event, pos, uid_counter);
502     pos += 2;
503     event[pos++] = browsing_status;
504     event[pos++] = bluetooth_status;
505     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
506 }
507 
508 static void avrcp_parser_reset(avrcp_browsing_connection_t * connection){
509     connection->parser_attribute_header_pos = 0;
510     connection->parsed_attribute_value_offset = 0;
511     connection->parsed_num_attributes = 0;
512     connection->parser_state = AVRCP_PARSER_GET_ATTRIBUTE_HEADER;
513 }
514 
515 
516 static void avrcp_browsing_parser_process_byte(uint8_t byte, avrcp_browsing_connection_t * connection){
517     uint8_t prepended_header_size = 1;
518     switch(connection->parser_state){
519         case AVRCP_PARSER_GET_ATTRIBUTE_HEADER:{
520             connection->parser_attribute_header[connection->parser_attribute_header_pos++] = byte;
521             if (connection->parser_attribute_header_pos < AVRCP_BROWSING_ITEM_HEADER_LEN) break;
522 
523             uint16_t attribute_total_value_len = big_endian_read_16(connection->parser_attribute_header, 1);
524             connection->parsed_attribute_value[connection->parsed_attribute_value_offset++] = connection->parser_attribute_header[0];   // prepend with item type
525             connection->parsed_attribute_value_len = btstack_min(attribute_total_value_len, AVRCP_MAX_ATTRIBUTTE_SIZE - prepended_header_size);                 // reduce AVRCP_MAX_ATTRIBUTTE_SIZE for the size ot item type
526             connection->parser_state = AVRCP_PARSER_GET_ATTRIBUTE_VALUE;
527             // printf("AVRCP_PARSER_GET_ATTRIBUTE_HEADER value len %d, to parse %d, offset %d\n", attribute_total_value_len, connection->parsed_attribute_value_len, connection->parsed_attribute_value_offset);
528             break;
529         }
530         case AVRCP_PARSER_GET_ATTRIBUTE_VALUE:{
531             connection->parsed_attribute_value[connection->parsed_attribute_value_offset++] = byte;
532             if (connection->parsed_attribute_value_offset < connection->parsed_attribute_value_len + prepended_header_size){
533                 break;
534             }
535             if (connection->parsed_attribute_value_offset < big_endian_read_16(connection->parser_attribute_header, 1)){
536                 connection->parser_state = AVRCP_PARSER_IGNORE_REST_OF_ATTRIBUTE_VALUE;
537                 break;
538             }
539             connection->parser_state = AVRCP_PARSER_GET_ATTRIBUTE_HEADER;
540             (*avrcp_controller_context.browsing_avrcp_callback)(AVRCP_BROWSING_DATA_PACKET, connection->l2cap_browsing_cid, &connection->parsed_attribute_value[0], connection->parsed_attribute_value_offset);
541             connection->parsed_num_attributes++;
542             connection->parsed_attribute_value_offset = 0;
543             connection->parser_attribute_header_pos = 0;
544 
545             if (connection->parsed_num_attributes == connection->num_items){
546                 avrcp_parser_reset(connection);
547                 break;
548             }
549             break;
550         }
551         case AVRCP_PARSER_IGNORE_REST_OF_ATTRIBUTE_VALUE:
552             connection->parsed_attribute_value_offset++;
553             if (connection->parsed_attribute_value_offset < big_endian_read_16(connection->parser_attribute_header, 1) + prepended_header_size){
554                 break;
555             }
556             connection->parser_state = AVRCP_PARSER_GET_ATTRIBUTE_HEADER;
557             (*avrcp_controller_context.browsing_avrcp_callback)(AVRCP_BROWSING_DATA_PACKET, connection->l2cap_browsing_cid, &connection->parsed_attribute_value[0], connection->parsed_attribute_value_offset);
558             connection->parsed_num_attributes++;
559             connection->parsed_attribute_value_offset = 0;
560             connection->parser_attribute_header_pos = 0;
561 
562             if (connection->parsed_num_attributes == connection->num_items){
563                 avrcp_parser_reset(connection);
564                 break;
565             }
566             break;
567         default:
568             break;
569     }
570 }
571 
572 static void avrcp_browsing_parse_and_emit_element_attrs(uint8_t * packet, uint16_t num_bytes_to_read, avrcp_browsing_connection_t * connection){
573     int i;
574     for (i=0;i<num_bytes_to_read;i++){
575         avrcp_browsing_parser_process_byte(packet[i], connection);
576     }
577 }
578 
579 static void avrcp_browsing_controller_emit_failed(btstack_packet_handler_t callback, uint16_t browsing_cid, uint8_t browsing_status, uint8_t bluetooth_status){
580     avrcp_browsing_controller_emit_done_with_uid_counter(callback, browsing_cid, 0, browsing_status, bluetooth_status);
581 }
582 
583 
584 static void avrcp_browsing_controller_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
585     avrcp_browsing_connection_t * browsing_connection;
586 
587     switch (packet_type) {
588         case L2CAP_DATA_PACKET:{
589             browsing_connection = get_avrcp_browsing_connection_for_l2cap_cid(channel, &avrcp_controller_context);
590             if (!browsing_connection) break;
591             // printf("received \n");
592             // printf_hexdump(packet,size);
593             int pos = 0;
594             uint8_t transport_header = packet[pos++];
595             // Transaction label | Packet_type | C/R | IPID (1 == invalid profile identifier)
596             browsing_connection->transaction_label = transport_header >> 4;
597             avrcp_packet_type_t avctp_packet_type = (transport_header & 0x0F) >> 2;
598             // printf("L2CAP_DATA_PACKET, packet type %d\n", avctp_packet_type);
599             switch (avctp_packet_type){
600                 case AVRCP_SINGLE_PACKET:
601                 case AVRCP_START_PACKET:
602                     // uint8_t frame_type = (transport_header & 0x03) >> 1;
603                     // uint8_t ipid = transport_header & 0x01;
604                     pos += 2;
605                     browsing_connection->num_packets = 1;
606                     if (avctp_packet_type == AVRCP_START_PACKET){
607                         browsing_connection->num_packets = packet[pos++];
608                     }
609                     if (pos + 4 > size){
610                         browsing_connection->state = AVCTP_CONNECTION_OPENED;
611                         avrcp_browsing_controller_emit_failed(avrcp_controller_context.browsing_avrcp_callback, channel, AVRCP_BROWSING_ERROR_CODE_INVALID_COMMAND, ERROR_CODE_SUCCESS);
612                         return;
613                     }
614                     browsing_connection->pdu_id = packet[pos++];
615                     // uint16_t length = big_endian_read_16(packet, pos);
616                     pos += 2;
617                     browsing_connection->browsing_status = packet[pos++];
618                     if (browsing_connection->browsing_status != AVRCP_BROWSING_ERROR_CODE_SUCCESS){
619                         browsing_connection->state = AVCTP_CONNECTION_OPENED;
620                         avrcp_browsing_controller_emit_failed(avrcp_controller_context.browsing_avrcp_callback, channel, browsing_connection->browsing_status, ERROR_CODE_SUCCESS);
621                         return;
622                     }
623                     break;
624                 default:
625                     break;
626             }
627 
628             uint32_t i;
629             switch(browsing_connection->pdu_id){
630                 case AVRCP_PDU_ID_CHANGE_PATH:
631                     // printf("AVRCP_PDU_ID_CHANGE_PATH \n");
632                     break;
633                 case AVRCP_PDU_ID_SET_ADDRESSED_PLAYER:
634                     // printf("AVRCP_PDU_ID_SET_ADDRESSED_PLAYER \n");
635                     break;
636                 case AVRCP_PDU_ID_GET_TOTAL_NUMBER_OF_ITEMS:{
637                     // uint32_t num_items = big_endian_read_32(packet, pos);
638                     // pos += 4;
639                     // printf("TODO: send event, uid_counter %d, num_items %d\n", browsing_connection->uid_counter, num_items);
640                     break;
641                 }
642                 case AVRCP_PDU_ID_SET_BROWSED_PLAYER:{
643                     browsing_connection->uid_counter =  big_endian_read_16(packet, pos);
644                     pos += 2;
645                     // uint32_t num_items = big_endian_read_32(packet, pos);
646                     pos += 4;
647                     // uint16_t charset = big_endian_read_16(packet, pos);
648                     pos += 2;
649                     uint8_t folder_depth = packet[pos++];
650 
651                     for (i = 0; i < folder_depth; i++){
652                         uint16_t folder_name_length = big_endian_read_16(packet, pos);
653                         pos += 2;
654                         // reuse packet and add data type as a header
655                         packet[pos-1] = AVRCP_BROWSING_MEDIA_ROOT_FOLDER;
656                         (*avrcp_controller_context.browsing_avrcp_callback)(AVRCP_BROWSING_DATA_PACKET, channel, packet+pos-1, folder_name_length+1);
657                         pos += folder_name_length;
658                     }
659                     break;
660                 }
661 
662                 case AVRCP_PDU_ID_GET_FOLDER_ITEMS:{
663                     switch (avctp_packet_type){
664                         case AVRCP_SINGLE_PACKET:
665                         case AVRCP_START_PACKET:
666                             avrcp_parser_reset(browsing_connection);
667                             browsing_connection->uid_counter =  big_endian_read_16(packet, pos);
668                             pos += 2;
669                             browsing_connection->num_items = big_endian_read_16(packet, pos); //num_items
670                             pos += 2;
671                             avrcp_browsing_parse_and_emit_element_attrs(packet+pos, size-pos, browsing_connection);
672                             break;
673 
674                         case AVRCP_CONTINUE_PACKET:
675                             avrcp_browsing_parse_and_emit_element_attrs(packet+pos, size-pos, browsing_connection);
676                             break;
677 
678                         case AVRCP_END_PACKET:
679                             avrcp_browsing_parse_and_emit_element_attrs(packet+pos, size-pos, browsing_connection);
680                             avrcp_parser_reset(browsing_connection);
681                             break;
682                     }
683                     break;
684                 }
685 
686                 case AVRCP_PDU_ID_SEARCH:{
687                     browsing_connection->uid_counter =  big_endian_read_16(packet, pos);
688                     pos += 2;
689                     // uint32_t num_items = big_endian_read_32(packet, pos);
690                     // printf("TODO: send as event, search found %d items\n", num_items);
691                     break;
692                 }
693                 case AVRCP_PDU_ID_GET_ITEM_ATTRIBUTES:
694                     packet[pos-1] = AVRCP_BROWSING_MEDIA_ELEMENT_ITEM_ATTRIBUTE;
695                     (*avrcp_controller_context.browsing_avrcp_callback)(AVRCP_BROWSING_DATA_PACKET, channel, packet+pos-1, size - pos + 1);
696                     break;
697 
698                 default:
699                     log_info(" not parsed pdu ID 0x%02x", browsing_connection->pdu_id);
700                     break;
701             }
702 
703             switch (avctp_packet_type){
704                 case AVRCP_SINGLE_PACKET:
705                 case AVRCP_END_PACKET:
706                     // printf("reset browsing connection state to OPENED\n");
707                     browsing_connection->state = AVCTP_CONNECTION_OPENED;
708                     avrcp_browsing_controller_emit_done_with_uid_counter(avrcp_controller_context.browsing_avrcp_callback, channel, browsing_connection->uid_counter, browsing_connection->browsing_status, ERROR_CODE_SUCCESS);
709                     break;
710                 default:
711                     break;
712             }
713             // printf(" paket done\n");
714             break;
715         }
716         case HCI_EVENT_PACKET:
717             switch (hci_event_packet_get_type(packet)){
718                 case L2CAP_EVENT_CAN_SEND_NOW:
719                     browsing_connection = get_avrcp_browsing_connection_for_l2cap_cid(channel, &avrcp_controller_context);
720                     if (!browsing_connection) break;
721                     avrcp_browsing_controller_handle_can_send_now(browsing_connection);
722                     break;
723                 default:
724                     avrcp_browser_packet_handler(packet_type, channel, packet, size, &avrcp_controller_context);
725                     break;
726             }
727             break;
728 
729         default:
730             break;
731     }
732 }
733 
734 void avrcp_browsing_controller_init(void){
735     avrcp_controller_context.browsing_packet_handler = avrcp_browsing_controller_packet_handler;
736     l2cap_register_service(&avrcp_browsing_controller_packet_handler, PSM_AVCTP_BROWSING, 0xffff, LEVEL_2);
737 }
738 
739 void avrcp_browsing_controller_register_packet_handler(btstack_packet_handler_t callback){
740     if (callback == NULL){
741         log_error("avrcp_browsing_controller_register_packet_handler called with NULL callback");
742         return;
743     }
744     avrcp_controller_context.browsing_avrcp_callback = callback;
745 }
746 
747 uint8_t avrcp_browsing_controller_connect(bd_addr_t bd_addr, uint8_t * ertm_buffer, uint32_t size, l2cap_ertm_config_t * ertm_config, uint16_t * avrcp_browsing_cid){
748     return avrcp_browsing_connect(bd_addr, &avrcp_controller_context, ertm_buffer, size, ertm_config, avrcp_browsing_cid);
749 }
750 
751 uint8_t avrcp_browsing_controller_disconnect(uint16_t avrcp_browsing_cid){
752     avrcp_connection_t * avrcp_connection = get_avrcp_connection_for_browsing_cid(avrcp_browsing_cid, &avrcp_controller_context);
753     if (!avrcp_connection){
754         log_error("avrcp_browsing_controller_disconnect: could not find a connection.");
755         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
756     }
757     if (avrcp_connection->browsing_connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
758 
759     l2cap_disconnect(avrcp_connection->browsing_connection->l2cap_browsing_cid, 0);
760     return ERROR_CODE_SUCCESS;
761 }
762 
763 uint8_t avrcp_browsing_controller_configure_incoming_connection(uint16_t avrcp_browsing_cid, uint8_t * ertm_buffer, uint32_t size, l2cap_ertm_config_t * ertm_config){
764     avrcp_connection_t * avrcp_connection = get_avrcp_connection_for_browsing_cid(avrcp_browsing_cid, &avrcp_controller_context);
765     if (!avrcp_connection){
766         log_error("avrcp_browsing_controller_decline_incoming_connection: could not find a connection.");
767         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
768     }
769     if (!avrcp_connection->browsing_connection){
770         log_error("avrcp_browsing_controller_decline_incoming_connection: no browsing connection.");
771         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
772     }
773 
774     if (avrcp_connection->browsing_connection->state != AVCTP_CONNECTION_W4_ERTM_CONFIGURATION){
775         log_error("avrcp_browsing_controller_decline_incoming_connection: browsing connection in a wrong state.");
776         return ERROR_CODE_COMMAND_DISALLOWED;
777     }
778 
779     avrcp_connection->browsing_connection->state = AVCTP_CONNECTION_W4_L2CAP_CONNECTED;
780     avrcp_connection->browsing_connection->ertm_buffer = ertm_buffer;
781     avrcp_connection->browsing_connection->ertm_buffer_size = size;
782     memcpy(&avrcp_connection->browsing_connection->ertm_config, ertm_config, sizeof(l2cap_ertm_config_t));
783     l2cap_accept_ertm_connection(avrcp_connection->browsing_connection->l2cap_browsing_cid, &avrcp_connection->browsing_connection->ertm_config, avrcp_connection->browsing_connection->ertm_buffer, avrcp_connection->browsing_connection->ertm_buffer_size);
784     return ERROR_CODE_SUCCESS;
785 }
786 
787 uint8_t avrcp_browsing_controller_decline_incoming_connection(uint16_t avrcp_browsing_cid){
788     avrcp_connection_t * avrcp_connection = get_avrcp_connection_for_browsing_cid(avrcp_browsing_cid, &avrcp_controller_context);
789     if (!avrcp_connection){
790         log_error("avrcp_browsing_controller_decline_incoming_connection: could not find a connection.");
791         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
792     }
793     if (!avrcp_connection->browsing_connection) return ERROR_CODE_SUCCESS;
794     if (avrcp_connection->browsing_connection->state > AVCTP_CONNECTION_W4_ERTM_CONFIGURATION) return ERROR_CODE_COMMAND_DISALLOWED;
795 
796     l2cap_decline_connection(avrcp_connection->browsing_connection->l2cap_browsing_cid);
797     // free connection
798     btstack_memory_avrcp_browsing_connection_free(avrcp_connection->browsing_connection);
799     avrcp_connection->browsing_connection = NULL;
800     return ERROR_CODE_SUCCESS;
801 }
802 
803 uint8_t avrcp_browsing_controller_get_item_attributes_for_scope(uint16_t avrcp_browsing_cid, uint8_t * uid, uint16_t uid_counter, uint32_t attr_bitmap, avrcp_browsing_scope_t scope){
804     avrcp_connection_t * avrcp_connection = get_avrcp_connection_for_browsing_cid(avrcp_browsing_cid, &avrcp_controller_context);
805     if (!avrcp_connection){
806         log_error("avrcp_browsing_controller_get_item_attributes: could not find a connection.");
807         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
808     }
809     avrcp_browsing_connection_t * connection = avrcp_connection->browsing_connection;
810     if (connection->state != AVCTP_CONNECTION_OPENED){
811         log_error("avrcp_browsing_controller_get_item_attributes: connection in wrong state %d, expected %d.", connection->state, AVCTP_CONNECTION_OPENED);
812         return ERROR_CODE_COMMAND_DISALLOWED;
813     }
814 
815     connection->get_item_attributes = 1;
816     connection->scope = scope;
817     memcpy(connection->folder_uid, uid, 8);
818     connection->uid_counter = uid_counter;
819     connection->attr_bitmap = attr_bitmap;
820 
821     avrcp_request_can_send_now(avrcp_connection, connection->l2cap_browsing_cid);
822     return ERROR_CODE_SUCCESS;
823 }
824 
825 /**
826  * @brief Retrieve a listing of the contents of a folder.
827  * @param scope    0-player list, 1-virtual file system, 2-search, 3-now playing
828  * @param start_item
829  * @param end_item
830  * @param attribute_count
831  * @param attribute_list
832  **/
833 static uint8_t avrcp_browsing_controller_get_folder_items(uint16_t avrcp_browsing_cid, avrcp_browsing_scope_t scope, uint32_t start_item, uint32_t end_item, uint32_t attr_bitmap){
834     avrcp_connection_t * avrcp_connection = get_avrcp_connection_for_browsing_cid(avrcp_browsing_cid, &avrcp_controller_context);
835     if (!avrcp_connection){
836         log_error("avrcp_browsing_controller_disconnect: could not find a connection.");
837         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
838     }
839     avrcp_browsing_connection_t * connection = avrcp_connection->browsing_connection;
840     if (connection->state != AVCTP_CONNECTION_OPENED) {
841         log_error("avrcp_browsing_controller_get_folder_items: connection in wrong state %d, expected %d.", connection->state, AVCTP_CONNECTION_OPENED);
842         return ERROR_CODE_COMMAND_DISALLOWED;
843     }
844 
845     connection->get_folder_items = 1;
846     connection->scope = scope;
847     connection->start_item = start_item;
848     connection->end_item = end_item;
849     connection->attr_bitmap = attr_bitmap;
850 
851     avrcp_request_can_send_now(avrcp_connection, connection->l2cap_browsing_cid);
852     return ERROR_CODE_SUCCESS;
853 }
854 
855 uint8_t avrcp_browsing_controller_get_media_players(uint16_t avrcp_browsing_cid, uint32_t start_item, uint32_t end_item, uint32_t attr_bitmap){
856     return avrcp_browsing_controller_get_folder_items(avrcp_browsing_cid, AVRCP_BROWSING_MEDIA_PLAYER_LIST, start_item, end_item, attr_bitmap);
857 }
858 
859 uint8_t avrcp_browsing_controller_browse_file_system(uint16_t avrcp_browsing_cid, uint32_t start_item, uint32_t end_item, uint32_t attr_bitmap){
860     // return avrcp_browsing_controller_get_folder_items(avrcp_browsing_cid, 1, 0, 0xFFFFFFFF, attr_bitmap);
861     return avrcp_browsing_controller_get_folder_items(avrcp_browsing_cid, AVRCP_BROWSING_MEDIA_PLAYER_VIRTUAL_FILESYSTEM, start_item, end_item, attr_bitmap);
862 }
863 
864 uint8_t avrcp_browsing_controller_browse_media(uint16_t avrcp_browsing_cid, uint32_t start_item, uint32_t end_item, uint32_t attr_bitmap){
865     // return avrcp_browsing_controller_get_folder_items(avrcp_browsing_cid, 2, 0, 0xFFFFFFFF, 0, NULL);
866     return avrcp_browsing_controller_get_folder_items(avrcp_browsing_cid, AVRCP_BROWSING_SEARCH, start_item, end_item, attr_bitmap);
867 }
868 
869 uint8_t avrcp_browsing_controller_browse_now_playing_list(uint16_t avrcp_browsing_cid, uint32_t start_item, uint32_t end_item, uint32_t attr_bitmap){
870     return avrcp_browsing_controller_get_folder_items(avrcp_browsing_cid, AVRCP_BROWSING_NOW_PLAYING, start_item, end_item, attr_bitmap);
871 }
872 
873 
874 uint8_t avrcp_browsing_controller_set_browsed_player(uint16_t avrcp_browsing_cid, uint16_t browsed_player_id){
875     avrcp_connection_t * avrcp_connection = get_avrcp_connection_for_browsing_cid(avrcp_browsing_cid, &avrcp_controller_context);
876     if (!avrcp_connection){
877         log_error("avrcp_browsing_controller_change_path: could not find a connection.");
878         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
879     }
880 
881     avrcp_browsing_connection_t * connection = avrcp_connection->browsing_connection;
882     if (connection->state != AVCTP_CONNECTION_OPENED){
883         log_error("avrcp_browsing_controller_change_path: connection in wrong state.");
884         return ERROR_CODE_COMMAND_DISALLOWED;
885     }
886 
887     connection->set_browsed_player_id = 1;
888     connection->browsed_player_id = browsed_player_id;
889     avrcp_request_can_send_now(avrcp_connection, connection->l2cap_browsing_cid);
890     return ERROR_CODE_SUCCESS;
891 }
892 
893 /**
894  * @brief Retrieve a listing of the contents of a folder.
895  * @param direction     0-folder up, 1-folder down
896  * @param folder_uid    8 bytes long
897  **/
898 uint8_t avrcp_browsing_controller_change_path(uint16_t avrcp_browsing_cid, uint8_t direction, uint8_t * folder_uid){
899     avrcp_connection_t * avrcp_connection = get_avrcp_connection_for_browsing_cid(avrcp_browsing_cid, &avrcp_controller_context);
900     if (!avrcp_connection){
901         log_error("avrcp_browsing_controller_change_path: could not find a connection.");
902         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
903     }
904 
905     avrcp_browsing_connection_t * connection = avrcp_connection->browsing_connection;
906 
907     if (!connection || connection->state != AVCTP_CONNECTION_OPENED){
908         log_error("avrcp_browsing_controller_change_path: connection in wrong state.");
909         return ERROR_CODE_COMMAND_DISALLOWED;
910     }
911 
912     if (!connection->browsed_player_id){
913         log_error("avrcp_browsing_controller_change_path: no browsed player set.");
914         return ERROR_CODE_COMMAND_DISALLOWED;
915     }
916     connection->change_path = 1;
917     connection->direction = direction;
918     memset(connection->folder_uid, 0, 8);
919     if (folder_uid){
920         memcpy(connection->folder_uid, folder_uid, 8);
921     }
922 
923     avrcp_request_can_send_now(avrcp_connection, connection->l2cap_browsing_cid);
924     return ERROR_CODE_SUCCESS;
925 }
926 
927 uint8_t avrcp_browsing_controller_go_up_one_level(uint16_t avrcp_browsing_cid){
928     return avrcp_browsing_controller_change_path(avrcp_browsing_cid, 0, NULL);
929 }
930 
931 uint8_t avrcp_browsing_controller_go_down_one_level(uint16_t avrcp_browsing_cid, uint8_t * folder_uid){
932     return avrcp_browsing_controller_change_path(avrcp_browsing_cid, 1, folder_uid);
933 }
934 
935 uint8_t avrcp_browsing_controller_search(uint16_t avrcp_browsing_cid, uint16_t search_str_len, char * search_str){
936     avrcp_connection_t * avrcp_connection = get_avrcp_connection_for_browsing_cid(avrcp_browsing_cid, &avrcp_controller_context);
937     if (!avrcp_connection){
938         log_error("avrcp_browsing_controller_change_path: could not find a connection.");
939         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
940     }
941 
942     avrcp_browsing_connection_t * connection = avrcp_connection->browsing_connection;
943 
944     if (!connection || connection->state != AVCTP_CONNECTION_OPENED){
945         log_error("avrcp_browsing_controller_change_path: connection in wrong state.");
946         return ERROR_CODE_COMMAND_DISALLOWED;
947     }
948 
949     if (!connection->browsed_player_id){
950         log_error("avrcp_browsing_controller_change_path: no browsed player set.");
951         return ERROR_CODE_COMMAND_DISALLOWED;
952     }
953     if (!search_str || search_str_len == 0){
954         return AVRCP_BROWSING_ERROR_CODE_INVALID_COMMAND;
955     }
956 
957     connection->search = 1;
958 
959     connection->search_str_len = btstack_min(search_str_len, sizeof(connection->search_str)-1);
960     memset(connection->search_str, 0, sizeof(connection->search_str));
961     memcpy(connection->search_str, search_str, connection->search_str_len);
962     avrcp_request_can_send_now(avrcp_connection, connection->l2cap_browsing_cid);
963     return ERROR_CODE_SUCCESS;
964 }
965 
966 uint8_t avrcp_browsing_controller_get_total_nr_items_for_scope(uint16_t avrcp_browsing_cid, avrcp_browsing_scope_t scope){
967     avrcp_connection_t * avrcp_connection = get_avrcp_connection_for_browsing_cid(avrcp_browsing_cid, &avrcp_controller_context);
968     if (!avrcp_connection){
969         log_error("avrcp_browsing_controller_change_path: could not find a connection.");
970         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
971     }
972 
973     avrcp_browsing_connection_t * connection = avrcp_connection->browsing_connection;
974 
975     if (!connection || connection->state != AVCTP_CONNECTION_OPENED){
976         log_error("avrcp_browsing_controller_change_path: connection in wrong state.");
977         return ERROR_CODE_COMMAND_DISALLOWED;
978     }
979 
980     if (!connection->browsed_player_id){
981         log_error("avrcp_browsing_controller_change_path: no browsed player set.");
982         return ERROR_CODE_COMMAND_DISALLOWED;
983     }
984     connection->get_total_nr_items = 1;
985     connection->get_total_nr_items_scope = scope;
986     avrcp_request_can_send_now(avrcp_connection, connection->l2cap_browsing_cid);
987     return ERROR_CODE_SUCCESS;
988 }
989