xref: /btstack/src/classic/avrcp_browsing_controller.c (revision 89d1b08950ee63cdc89180b93e8c22cb3a8d7c05)
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 
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 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 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     // transport header
255     // Transaction label | Packet_type | C/R | IPID (1 == invalid profile identifier)
256     command[pos++] = (connection->transaction_label << 4) | (AVRCP_SINGLE_PACKET << 2) | (AVRCP_COMMAND_FRAME << 1) | 0;
257     // Profile IDentifier (PID)
258     command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL >> 8;
259     command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL & 0x00FF;
260     command[pos++] = AVRCP_PDU_ID_GET_FOLDER_ITEMS;
261 
262     uint32_t attribute_count = 0;
263     uint32_t attributes_to_copy = 0;
264 
265     switch (connection->attr_bitmap){
266         case AVRCP_MEDIA_ATTR_NONE:
267             attribute_count = AVRCP_MEDIA_ATTR_NONE; // 0xFFFFFFFF
268             break;
269         case AVRCP_MEDIA_ATTR_ALL:
270             attribute_count = AVRCP_MEDIA_ATTR_ALL;  // 0
271             break;
272         default:
273             attribute_count = count_set_bits_uint32(connection->attr_bitmap & 0xff);
274             attributes_to_copy = attribute_count;
275             break;
276     }
277 
278     big_endian_store_16(command, pos, 10 + attribute_count);
279     pos += 2;
280     command[pos++] = connection->scope;
281     big_endian_store_32(command, pos, connection->start_item);
282     pos += 4;
283     big_endian_store_32(command, pos, connection->end_item);
284     pos += 4;
285     command[pos++] = attribute_count;
286 
287     int bit_position = 1;
288     while (attributes_to_copy){
289         if (connection->attr_bitmap & (1 << bit_position)){
290             big_endian_store_32(command, pos, bit_position);
291             pos += 4;
292             attributes_to_copy--;
293         }
294         bit_position++;
295     }
296 
297     return l2cap_send(cid, command, pos);
298 }
299 
300 static int avrcp_browsing_controller_send_change_path_cmd(uint16_t cid, avrcp_browsing_connection_t * connection){
301     uint8_t command[100];
302     int pos = 0;
303     // transport header
304     // Transaction label | Packet_type | C/R | IPID (1 == invalid profile identifier)
305     command[pos++] = (connection->transaction_label << 4) | (AVRCP_SINGLE_PACKET << 2) | (AVRCP_COMMAND_FRAME << 1) | 0;
306     // Profile IDentifier (PID)
307     command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL >> 8;
308     command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL & 0x00FF;
309     command[pos++] = AVRCP_PDU_ID_CHANGE_PATH;
310 
311     big_endian_store_16(command, pos, 11);
312     pos += 2;
313     pos += 2;
314     command[pos++] = connection->direction;
315     memcpy(command+pos, connection->folder_uid, 8);
316     pos += 8;
317     return l2cap_send(cid, command, pos);
318 }
319 
320 static int avrcp_browsing_controller_send_search_cmd(uint16_t cid, avrcp_browsing_connection_t * connection){
321     uint8_t command[100];
322     int pos = 0;
323     // transport header
324     // Transaction label | Packet_type | C/R | IPID (1 == invalid profile identifier)
325     command[pos++] = (connection->transaction_label << 4) | (AVRCP_SINGLE_PACKET << 2) | (AVRCP_COMMAND_FRAME << 1) | 0;
326     // Profile IDentifier (PID)
327     command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL >> 8;
328     command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL & 0x00FF;
329     command[pos++] = AVRCP_PDU_ID_SEARCH;
330 
331     big_endian_store_16(command, pos, 4 + connection->search_str_len);
332     pos += 2;
333 
334     big_endian_store_16(command, pos, 0x006A);
335     pos += 2;
336     big_endian_store_16(command, pos, connection->search_str_len);
337     pos += 2;
338 
339     memcpy(command+pos,connection->search_str, connection->search_str_len);
340     pos += connection->search_str_len;
341     return l2cap_send(cid, command, pos);
342 }
343 
344 static int avrcp_browsing_controller_send_set_browsed_player_cmd(uint16_t cid, avrcp_browsing_connection_t * connection){
345     uint8_t command[100];
346     int pos = 0;
347     // transport header
348     // Transaction label | Packet_type | C/R | IPID (1 == invalid profile identifier)
349     command[pos++] = (connection->transaction_label << 4) | (AVRCP_SINGLE_PACKET << 2) | (AVRCP_COMMAND_FRAME << 1) | 0;
350     // Profile IDentifier (PID)
351     command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL >> 8;
352     command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL & 0x00FF;
353     command[pos++] = AVRCP_PDU_ID_SET_BROWSED_PLAYER;
354 
355     big_endian_store_16(command, pos, 2);
356     pos += 2;
357     big_endian_store_16(command, pos, connection->browsed_player_id);
358     pos += 2;
359     return l2cap_send(cid, command, pos);
360 }
361 
362 static int avrcp_browsing_controller_send_get_total_nr_items_cmd(uint16_t cid, avrcp_browsing_connection_t * connection){
363     uint8_t command[7];
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_GET_TOTAL_NUMBER_OF_ITEMS;
372 
373     big_endian_store_16(command, pos, 1);
374     pos += 2;
375     command[pos++] = connection->get_total_nr_items_scope;
376     return l2cap_send(cid, command, pos);
377 }
378 
379 static void avrcp_browsing_controller_handle_can_send_now(avrcp_browsing_connection_t * connection){
380     switch (connection->state){
381         case AVCTP_CONNECTION_OPENED:
382             if (connection->set_browsed_player_id){
383                 connection->state = AVCTP_W2_RECEIVE_RESPONSE;
384                 connection->set_browsed_player_id = 0;
385                 avrcp_browsing_controller_send_set_browsed_player_cmd(connection->l2cap_browsing_cid, connection);
386                 break;
387             }
388 
389             if (connection->get_total_nr_items){
390                 connection->state = AVCTP_W2_RECEIVE_RESPONSE;
391                 connection->get_total_nr_items = 0;
392                 avrcp_browsing_controller_send_get_total_nr_items_cmd(connection->l2cap_browsing_cid, connection);
393                 break;
394             }
395 
396             if (connection->get_folder_item){
397                 connection->state = AVCTP_W2_RECEIVE_RESPONSE;
398                 connection->get_folder_item = 0;
399                 avrcp_browsing_controller_send_get_folder_items_cmd(connection->l2cap_browsing_cid, connection);
400                 break;
401             }
402             if (connection->change_path){
403                 connection->state = AVCTP_W2_RECEIVE_RESPONSE;
404                 connection->change_path = 0;
405                 avrcp_browsing_controller_send_change_path_cmd(connection->l2cap_browsing_cid, connection);
406                 break;
407             }
408             if (connection->search){
409                 connection->state = AVCTP_W2_RECEIVE_RESPONSE;
410                 connection->search = 0;
411                 avrcp_browsing_controller_send_search_cmd(connection->l2cap_browsing_cid, connection);
412                 break;
413             }
414             break;
415         default:
416             return;
417     }
418 }
419 
420 
421 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){
422     if (!callback) return;
423     uint8_t event[9];
424     int pos = 0;
425     event[pos++] = HCI_EVENT_AVRCP_META;
426     event[pos++] = sizeof(event) - 2;
427     event[pos++] = AVRCP_SUBEVENT_BROWSING_DONE;
428     little_endian_store_16(event, pos, browsing_cid);
429     pos += 2;
430     little_endian_store_16(event, pos, uid_counter);
431     pos += 2;
432     event[pos++] = browsing_status;
433     event[pos++] = bluetooth_status;
434     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
435 }
436 
437 static void avrcp_parser_reset(avrcp_browsing_connection_t * connection){
438     connection->parser_attribute_header_pos = 0;
439     connection->parsed_attribute_value_offset = 0;
440     connection->parsed_num_attributes = 0;
441     connection->parser_state = AVRCP_PARSER_GET_ATTRIBUTE_HEADER;
442 }
443 
444 
445 static void avrcp_browsing_parser_process_byte(uint8_t byte, avrcp_browsing_connection_t * connection){
446     uint8_t prepended_header_size = 1;
447     switch(connection->parser_state){
448         case AVRCP_PARSER_GET_ATTRIBUTE_HEADER:{
449             connection->parser_attribute_header[connection->parser_attribute_header_pos++] = byte;
450             if (connection->parser_attribute_header_pos < AVRCP_BROWSING_ITEM_HEADER_LEN) break;
451 
452             uint16_t attribute_total_value_len = big_endian_read_16(connection->parser_attribute_header, 1);
453             connection->parsed_attribute_value[connection->parsed_attribute_value_offset++] = connection->parser_attribute_header[0];   // prepend with item type
454             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
455             connection->parser_state = AVRCP_PARSER_GET_ATTRIBUTE_VALUE;
456             // 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);
457             break;
458         }
459         case AVRCP_PARSER_GET_ATTRIBUTE_VALUE:{
460             connection->parsed_attribute_value[connection->parsed_attribute_value_offset++] = byte;
461             if (connection->parsed_attribute_value_offset < connection->parsed_attribute_value_len + prepended_header_size){
462                 break;
463             }
464             if (connection->parsed_attribute_value_offset < big_endian_read_16(connection->parser_attribute_header, 1)){
465                 connection->parser_state = AVRCP_PARSER_IGNORE_REST_OF_ATTRIBUTE_VALUE;
466                 break;
467             }
468             connection->parser_state = AVRCP_PARSER_GET_ATTRIBUTE_HEADER;
469             (*avrcp_controller_context.browsing_avrcp_callback)(AVRCP_BROWSING_DATA_PACKET, connection->l2cap_browsing_cid, &connection->parsed_attribute_value[0], connection->parsed_attribute_value_offset);
470             connection->parsed_num_attributes++;
471             connection->parsed_attribute_value_offset = 0;
472             connection->parser_attribute_header_pos = 0;
473 
474             if (connection->parsed_num_attributes == connection->num_items){
475                 avrcp_parser_reset(connection);
476                 break;
477             }
478             break;
479         }
480         case AVRCP_PARSER_IGNORE_REST_OF_ATTRIBUTE_VALUE:
481             connection->parsed_attribute_value_offset++;
482             if (connection->parsed_attribute_value_offset < big_endian_read_16(connection->parser_attribute_header, 1) + prepended_header_size){
483                 break;
484             }
485             connection->parser_state = AVRCP_PARSER_GET_ATTRIBUTE_HEADER;
486             (*avrcp_controller_context.browsing_avrcp_callback)(AVRCP_BROWSING_DATA_PACKET, connection->l2cap_browsing_cid, &connection->parsed_attribute_value[0], connection->parsed_attribute_value_offset);
487             connection->parsed_num_attributes++;
488             connection->parsed_attribute_value_offset = 0;
489             connection->parser_attribute_header_pos = 0;
490 
491             if (connection->parsed_num_attributes == connection->num_items){
492                 avrcp_parser_reset(connection);
493                 break;
494             }
495             break;
496         default:
497             break;
498     }
499 }
500 
501 static void avrcp_browsing_parse_and_emit_element_attrs(uint8_t * packet, uint16_t num_bytes_to_read, avrcp_browsing_connection_t * connection){
502     int i;
503     for (i=0;i<num_bytes_to_read;i++){
504         avrcp_browsing_parser_process_byte(packet[i], connection);
505     }
506 }
507 
508 static void avrcp_browsing_controller_emit_done(btstack_packet_handler_t callback, uint16_t browsing_cid, uint8_t browsing_status, uint8_t bluetooth_status){
509     avrcp_browsing_controller_emit_done_with_uid_counter(callback, browsing_cid, 0, browsing_status, bluetooth_status);
510 }
511 
512 
513 static void avrcp_browsing_controller_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
514     avrcp_browsing_connection_t * browsing_connection;
515 
516     switch (packet_type) {
517         case L2CAP_DATA_PACKET:{
518             browsing_connection = get_avrcp_browsing_connection_for_l2cap_cid(channel, &avrcp_controller_context);
519             if (!browsing_connection) break;
520             int pos = 0;
521             uint8_t transport_header = packet[pos++];
522             // Transaction label | Packet_type | C/R | IPID (1 == invalid profile identifier)
523             // uint8_t transaction_label = transport_header >> 4;
524             avrcp_packet_type_t avctp_packet_type = (transport_header & 0x0F) >> 2;
525             // printf("L2CAP_DATA_PACKET, packet type \n");
526             switch (avctp_packet_type){
527                 case AVRCP_SINGLE_PACKET:
528                 case AVRCP_START_PACKET:
529                     // uint8_t frame_type = (transport_header & 0x03) >> 1;
530                     // uint8_t ipid = transport_header & 0x01;
531                     pos += 2;
532                     browsing_connection->num_packets = 1;
533                     if (avctp_packet_type == AVRCP_START_PACKET){
534                         browsing_connection->num_packets = packet[pos++];
535                     }
536                     if (pos + 4 > size){
537                         avrcp_browsing_controller_emit_done(avrcp_controller_context.browsing_avrcp_callback, channel, AVRCP_BROWSING_ERROR_CODE_INVALID_COMMAND, ERROR_CODE_SUCCESS);
538                         return;
539                     }
540                     browsing_connection->pdu_id = packet[pos++];
541                     // uint16_t length = big_endian_read_16(packet, pos);
542                     pos += 2;
543                     browsing_connection->browsing_status = packet[pos++];
544                     if (browsing_connection->browsing_status != AVRCP_BROWSING_ERROR_CODE_SUCCESS){
545                         avrcp_browsing_controller_emit_done(avrcp_controller_context.browsing_avrcp_callback, channel, browsing_connection->browsing_status, ERROR_CODE_SUCCESS);
546                         return;
547                     }
548                     browsing_connection->uid_counter =  big_endian_read_16(packet, pos);
549                     pos += 2;
550                     break;
551                 default:
552                     break;
553             }
554 
555             uint32_t i;
556             switch(browsing_connection->pdu_id){
557                 case AVRCP_PDU_ID_CHANGE_PATH:
558                     printf("AVRCP_PDU_ID_CHANGE_PATH \n");
559                     break;
560                 case AVRCP_PDU_ID_SET_ADDRESSED_PLAYER:
561                     printf("AVRCP_PDU_ID_SET_ADDRESSED_PLAYER \n");
562                     break;
563                 case AVRCP_PDU_ID_GET_TOTAL_NUMBER_OF_ITEMS:{
564                     uint32_t num_items = big_endian_read_32(packet, pos);
565                     pos += 4;
566                     printf("TDO: send event, uid_counter %d, num_items %d\n", browsing_connection->uid_counter, num_items);
567                     break;
568                 }
569                 case AVRCP_PDU_ID_SET_BROWSED_PLAYER:{
570                     // uint32_t num_items = big_endian_read_32(packet, pos);
571                     pos += 4;
572                     // uint16_t charset = big_endian_read_16(packet, pos);
573                     pos += 2;
574                     uint8_t folder_depth = packet[pos++];
575 
576                     for (i = 0; i < folder_depth; i++){
577                         uint16_t folder_name_length = big_endian_read_16(packet, pos);
578                         pos += 2;
579                         // reuse packet and add data type as a header
580                         packet[pos-1] = AVRCP_BROWSING_MEDIA_ROOT_FOLDER;
581                         (*avrcp_controller_context.browsing_avrcp_callback)(AVRCP_BROWSING_DATA_PACKET, channel, packet+pos-1, folder_name_length+1);
582                         pos += folder_name_length;
583                     }
584                     break;
585                 }
586 
587                 case AVRCP_PDU_ID_GET_FOLDER_ITEMS:{
588                     printf("AVRCP_PDU_ID_GET_FOLDER_ITEMS\n");
589                     switch (avctp_packet_type){
590                         case AVRCP_SINGLE_PACKET:
591                         case AVRCP_START_PACKET:
592                             avrcp_parser_reset(browsing_connection);
593                             browsing_connection->num_items = big_endian_read_16(packet, pos); //num_items
594                             pos += 2;
595                             printf(" num items %d\n", browsing_connection->num_items);
596                             avrcp_browsing_parse_and_emit_element_attrs(packet+pos, size-pos, browsing_connection);
597                             break;
598 
599                         case AVRCP_CONTINUE_PACKET:
600                             avrcp_browsing_parse_and_emit_element_attrs(packet+pos, size-pos, browsing_connection);
601                             break;
602 
603                         case AVRCP_END_PACKET:
604                             avrcp_browsing_parse_and_emit_element_attrs(packet+pos, size-pos, browsing_connection);
605                             avrcp_parser_reset(browsing_connection);
606                             break;
607                     }
608                     break;
609                 }
610 
611                 case AVRCP_PDU_ID_SEARCH:{
612                         uint32_t num_items = big_endian_read_32(packet, pos);
613                         printf("TODO: send as event, search found %d items\n", num_items);
614                         break;
615                     }
616                 default:
617                     break;
618             }
619 
620             switch (avctp_packet_type){
621                 case AVRCP_SINGLE_PACKET:
622                 case AVRCP_END_PACKET:
623                     browsing_connection->state = AVCTP_CONNECTION_OPENED;
624                     avrcp_browsing_controller_emit_done(avrcp_controller_context.browsing_avrcp_callback, channel, browsing_connection->browsing_status, ERROR_CODE_SUCCESS);
625                     break;
626                 default:
627                     break;
628             }
629             break;
630         }
631         case HCI_EVENT_PACKET:
632             switch (hci_event_packet_get_type(packet)){
633                 case L2CAP_EVENT_CAN_SEND_NOW:
634                     browsing_connection = get_avrcp_browsing_connection_for_l2cap_cid(channel, &avrcp_controller_context);
635                     if (!browsing_connection) break;
636                     avrcp_browsing_controller_handle_can_send_now(browsing_connection);
637                     break;
638             default:
639                 avrcp_browser_packet_handler(packet_type, channel, packet, size, &avrcp_controller_context);
640                 break;
641         }
642         default:
643             break;
644     }
645 }
646 
647 void avrcp_browsing_controller_init(void){
648     avrcp_controller_context.browsing_packet_handler = avrcp_browsing_controller_packet_handler;
649     l2cap_register_service(&avrcp_browsing_controller_packet_handler, PSM_AVCTP_BROWSING, 0xffff, LEVEL_0);
650 }
651 
652 void avrcp_browsing_controller_register_packet_handler(btstack_packet_handler_t callback){
653     if (callback == NULL){
654         log_error("avrcp_browsing_controller_register_packet_handler called with NULL callback");
655         return;
656     }
657     avrcp_controller_context.browsing_avrcp_callback = callback;
658 }
659 
660 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){
661     return avrcp_browsing_connect(bd_addr, &avrcp_controller_context, ertm_buffer, size, ertm_config, avrcp_browsing_cid);
662 }
663 
664 uint8_t avrcp_browsing_controller_disconnect(uint16_t avrcp_browsing_cid){
665     avrcp_connection_t * avrcp_connection = get_avrcp_connection_for_browsing_cid(avrcp_browsing_cid, &avrcp_controller_context);
666     if (!avrcp_connection){
667         log_error("avrcp_browsing_controller_disconnect: could not find a connection.");
668         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
669     }
670     if (avrcp_connection->browsing_connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
671 
672     l2cap_disconnect(avrcp_connection->browsing_connection->l2cap_browsing_cid, 0);
673     return ERROR_CODE_SUCCESS;
674 }
675 
676 uint8_t avrcp_avrcp_browsing_configure_incoming_connection(uint16_t avrcp_browsing_cid, uint8_t * ertm_buffer, uint32_t size, l2cap_ertm_config_t * ertm_config){
677     avrcp_connection_t * avrcp_connection = get_avrcp_connection_for_browsing_cid(avrcp_browsing_cid, &avrcp_controller_context);
678     if (!avrcp_connection){
679         log_error("avrcp_avrcp_browsing_decline_incoming_connection: could not find a connection.");
680         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
681     }
682     if (!avrcp_connection->browsing_connection){
683         log_error("avrcp_avrcp_browsing_decline_incoming_connection: no browsing connection.");
684         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
685     }
686 
687     if (avrcp_connection->browsing_connection->state != AVCTP_CONNECTION_W4_ERTM_CONFIGURATION){
688         log_error("avrcp_avrcp_browsing_decline_incoming_connection: browsing connection in a wrong state.");
689         return ERROR_CODE_COMMAND_DISALLOWED;
690     }
691 
692     avrcp_connection->browsing_connection->state = AVCTP_CONNECTION_W4_L2CAP_CONNECTED;
693     avrcp_connection->browsing_connection->ertm_buffer = ertm_buffer;
694     avrcp_connection->browsing_connection->ertm_buffer_size = size;
695     memcpy(&avrcp_connection->browsing_connection->ertm_config, ertm_config, sizeof(l2cap_ertm_config_t));
696     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);
697     return ERROR_CODE_SUCCESS;
698 }
699 
700 uint8_t avrcp_avrcp_browsing_decline_incoming_connection(uint16_t avrcp_browsing_cid){
701     avrcp_connection_t * avrcp_connection = get_avrcp_connection_for_browsing_cid(avrcp_browsing_cid, &avrcp_controller_context);
702     if (!avrcp_connection){
703         log_error("avrcp_avrcp_browsing_decline_incoming_connection: could not find a connection.");
704         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
705     }
706     if (!avrcp_connection->browsing_connection) return ERROR_CODE_SUCCESS;
707     if (avrcp_connection->browsing_connection->state > AVCTP_CONNECTION_W4_ERTM_CONFIGURATION) return ERROR_CODE_COMMAND_DISALLOWED;
708 
709     l2cap_decline_connection(avrcp_connection->browsing_connection->l2cap_browsing_cid);
710     // free connection
711     btstack_memory_avrcp_browsing_connection_free(avrcp_connection->browsing_connection);
712     avrcp_connection->browsing_connection = NULL;
713     return ERROR_CODE_SUCCESS;
714 }
715 
716 /**
717  * @brief Retrieve a listing of the contents of a folder.
718  * @param scope    0-player list, 1-virtual file system, 2-search, 3-now playing
719  * @param start_item
720  * @param end_item
721  * @param attribute_count
722  * @param attribute_list
723  **/
724 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){
725     avrcp_connection_t * avrcp_connection = get_avrcp_connection_for_browsing_cid(avrcp_browsing_cid, &avrcp_controller_context);
726     if (!avrcp_connection){
727         log_error("avrcp_browsing_controller_disconnect: could not find a connection.");
728         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
729     }
730     avrcp_browsing_connection_t * connection = avrcp_connection->browsing_connection;
731     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
732 
733     connection->get_folder_item = 1;
734     connection->scope = scope;
735     connection->start_item = start_item;
736     connection->end_item = end_item;
737     connection->attr_bitmap = attr_bitmap;
738 
739     avrcp_request_can_send_now(avrcp_connection, connection->l2cap_browsing_cid);
740     return ERROR_CODE_SUCCESS;
741 }
742 
743 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){
744     return avrcp_browsing_controller_get_folder_items(avrcp_browsing_cid, AVRCP_BROWSING_MEDIA_PLAYER_LIST, start_item, end_item, attr_bitmap);
745 }
746 
747 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){
748     // return avrcp_browsing_controller_get_folder_items(avrcp_browsing_cid, 1, 0, 0xFFFFFFFF, attr_bitmap);
749     return avrcp_browsing_controller_get_folder_items(avrcp_browsing_cid, AVRCP_BROWSING_MEDIA_PLAYER_VIRTUAL_FILESYSTEM, start_item, end_item, attr_bitmap);
750 }
751 
752 uint8_t avrcp_browsing_controller_browse_media(uint16_t avrcp_browsing_cid, uint32_t start_item, uint32_t end_item, uint32_t attr_bitmap){
753     // return avrcp_browsing_controller_get_folder_items(avrcp_browsing_cid, 2, 0, 0xFFFFFFFF, 0, NULL);
754     return avrcp_browsing_controller_get_folder_items(avrcp_browsing_cid, AVRCP_BROWSING_SEARCH, start_item, end_item, attr_bitmap);
755 }
756 
757 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){
758     return avrcp_browsing_controller_get_folder_items(avrcp_browsing_cid, AVRCP_BROWSING_NOW_PLAYING, start_item, end_item, attr_bitmap);
759 }
760 
761 
762 uint8_t avrcp_browsing_controller_set_browsed_player(uint16_t avrcp_browsing_cid, uint16_t browsed_player_id){
763     avrcp_connection_t * avrcp_connection = get_avrcp_connection_for_browsing_cid(avrcp_browsing_cid, &avrcp_controller_context);
764     if (!avrcp_connection){
765         log_error("avrcp_browsing_controller_change_path: could not find a connection.");
766         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
767     }
768 
769     avrcp_browsing_connection_t * connection = avrcp_connection->browsing_connection;
770     if (connection->state != AVCTP_CONNECTION_OPENED){
771         log_error("avrcp_browsing_controller_change_path: connection in wrong state.");
772         return ERROR_CODE_COMMAND_DISALLOWED;
773     }
774 
775     connection->set_browsed_player_id = 1;
776     connection->browsed_player_id = browsed_player_id;
777     avrcp_request_can_send_now(avrcp_connection, connection->l2cap_browsing_cid);
778     return ERROR_CODE_SUCCESS;
779 }
780 
781 /**
782  * @brief Retrieve a listing of the contents of a folder.
783  * @param direction     0-folder up, 1-folder down
784  * @param folder_uid    8 bytes long
785  **/
786 uint8_t avrcp_browsing_controller_change_path(uint16_t avrcp_browsing_cid, uint8_t direction, uint8_t * folder_uid){
787     avrcp_connection_t * avrcp_connection = get_avrcp_connection_for_browsing_cid(avrcp_browsing_cid, &avrcp_controller_context);
788     if (!avrcp_connection){
789         log_error("avrcp_browsing_controller_change_path: could not find a connection.");
790         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
791     }
792 
793     avrcp_browsing_connection_t * connection = avrcp_connection->browsing_connection;
794 
795     if (!connection || connection->state != AVCTP_CONNECTION_OPENED){
796         log_error("avrcp_browsing_controller_change_path: connection in wrong state.");
797         return ERROR_CODE_COMMAND_DISALLOWED;
798     }
799 
800     if (!connection->browsed_player_id){
801         log_error("avrcp_browsing_controller_change_path: no browsed player set.");
802         return ERROR_CODE_COMMAND_DISALLOWED;
803     }
804     printf(" send change path\n");
805     connection->change_path = 1;
806     connection->direction = direction;
807     memset(connection->folder_uid, 0, 8);
808     if (folder_uid){
809         memcpy(connection->folder_uid, folder_uid, 8);
810     }
811 
812     avrcp_request_can_send_now(avrcp_connection, connection->l2cap_browsing_cid);
813     return ERROR_CODE_SUCCESS;
814 }
815 
816 uint8_t avrcp_browsing_controller_go_up_one_level(uint16_t avrcp_browsing_cid){
817     return avrcp_browsing_controller_change_path(avrcp_browsing_cid, 0, NULL);
818 }
819 
820 uint8_t avrcp_browsing_controller_go_down_one_level(uint16_t avrcp_browsing_cid, uint8_t * folder_uid){
821     return avrcp_browsing_controller_change_path(avrcp_browsing_cid, 1, folder_uid);
822 }
823 
824 uint8_t avrcp_browsing_controller_search(uint16_t avrcp_browsing_cid, uint16_t search_str_len, char * search_str){
825     avrcp_connection_t * avrcp_connection = get_avrcp_connection_for_browsing_cid(avrcp_browsing_cid, &avrcp_controller_context);
826     if (!avrcp_connection){
827         log_error("avrcp_browsing_controller_change_path: could not find a connection.");
828         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
829     }
830 
831     avrcp_browsing_connection_t * connection = avrcp_connection->browsing_connection;
832 
833     if (!connection || connection->state != AVCTP_CONNECTION_OPENED){
834         log_error("avrcp_browsing_controller_change_path: connection in wrong state.");
835         return ERROR_CODE_COMMAND_DISALLOWED;
836     }
837 
838     if (!connection->browsed_player_id){
839         log_error("avrcp_browsing_controller_change_path: no browsed player set.");
840         return ERROR_CODE_COMMAND_DISALLOWED;
841     }
842     if (!search_str || search_str_len == 0){
843         return AVRCP_BROWSING_ERROR_CODE_INVALID_COMMAND;
844     }
845 
846     connection->search = 1;
847 
848     connection->search_str_len = btstack_min(search_str_len, sizeof(connection->search_str)-1);
849     memset(connection->search_str, 0, sizeof(connection->search_str));
850     memcpy(connection->search_str, search_str, connection->search_str_len);
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_total_nr_items(uint16_t avrcp_browsing_cid, avrcp_browsing_scope_t scope){
856     avrcp_connection_t * avrcp_connection = get_avrcp_connection_for_browsing_cid(avrcp_browsing_cid, &avrcp_controller_context);
857     if (!avrcp_connection){
858         log_error("avrcp_browsing_controller_change_path: could not find a connection.");
859         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
860     }
861 
862     avrcp_browsing_connection_t * connection = avrcp_connection->browsing_connection;
863 
864     if (!connection || connection->state != AVCTP_CONNECTION_OPENED){
865         log_error("avrcp_browsing_controller_change_path: connection in wrong state.");
866         return ERROR_CODE_COMMAND_DISALLOWED;
867     }
868 
869     if (!connection->browsed_player_id){
870         log_error("avrcp_browsing_controller_change_path: no browsed player set.");
871         return ERROR_CODE_COMMAND_DISALLOWED;
872     }
873     connection->get_total_nr_items = 1;
874     connection->get_total_nr_items_scope = scope;
875     avrcp_request_can_send_now(avrcp_connection, connection->l2cap_browsing_cid);
876     return ERROR_CODE_SUCCESS;
877 }