xref: /btstack/src/classic/avdtp.c (revision f751daa3e83b8c78f824b3d6cfa8412a4f191539)
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__ "avdtp.c"
39 
40 
41 #include <stdint.h>
42 #include <string.h>
43 
44 #include "bluetooth_psm.h"
45 #include "bluetooth_sdp.h"
46 #include "btstack_debug.h"
47 #include "btstack_event.h"
48 #include "btstack_memory.h"
49 #include "classic/avdtp.h"
50 #include "classic/avdtp_acceptor.h"
51 #include "classic/avdtp_initiator.h"
52 #include "classic/avdtp_util.h"
53 #include "classic/sdp_client.h"
54 #include "classic/sdp_util.h"
55 
56 avdtp_context_t * avdtp_source_context = NULL;
57 avdtp_context_t * avdtp_sink_context = NULL;
58 
59 btstack_linked_list_t stream_endpoints;
60 
61 static btstack_packet_handler_t avdtp_source_callback;
62 static btstack_packet_handler_t avdtp_sink_callback;
63 
64 static uint16_t sdp_query_context_avdtp_cid = 0;
65 
66 static uint16_t stream_endpoints_id_counter = 0;
67 
68 static btstack_linked_list_t connections;
69 static uint16_t initiator_transaction_id_counter = 0;
70 
71 static int record_id = -1;
72 static uint8_t   attribute_value[45];
73 static const unsigned int attribute_value_buffer_size = sizeof(attribute_value);
74 
75 static void (*avdtp_sink_handle_media_data)(uint8_t local_seid, uint8_t *packet, uint16_t size);
76 
77 static uint16_t avdtp_cid_counter = 0;
78 
79 static void avdtp_handle_sdp_client_query_result(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
80 
81 btstack_packet_handler_t
82 avdtp_packet_handler_for_stream_endpoint(const avdtp_stream_endpoint_t *stream_endpoint) {
83     return (stream_endpoint->sep.type == AVDTP_SOURCE) ? avdtp_source_callback : avdtp_sink_callback;
84 }
85 
86 static void avdtp_streaming_emit_connection_established(avdtp_stream_endpoint_t *stream_endpoint, uint8_t status) {
87     uint8_t event[14];
88     int pos = 0;
89     event[pos++] = HCI_EVENT_AVDTP_META;
90     event[pos++] = sizeof(event) - 2;
91     event[pos++] = AVDTP_SUBEVENT_STREAMING_CONNECTION_ESTABLISHED;
92     little_endian_store_16(event, pos, stream_endpoint->connection->avdtp_cid);
93     pos += 2;
94     reverse_bd_addr(stream_endpoint->connection->remote_addr, &event[pos]);
95     pos += 6;
96     event[pos++] = avdtp_local_seid(stream_endpoint);
97     event[pos++] = avdtp_remote_seid(stream_endpoint);
98     event[pos++] = status;
99 
100     btstack_packet_handler_t packet_handler = avdtp_packet_handler_for_stream_endpoint(stream_endpoint);
101     (*packet_handler)(HCI_EVENT_PACKET, 0, event, sizeof(event));
102 }
103 
104 static void avdtp_streaming_emit_connection_released(avdtp_stream_endpoint_t *stream_endpoint, uint16_t avdtp_cid, uint8_t local_seid) {
105     uint8_t event[6];
106     int pos = 0;
107     event[pos++] = HCI_EVENT_AVDTP_META;
108     event[pos++] = sizeof(event) - 2;
109     event[pos++] = AVDTP_SUBEVENT_STREAMING_CONNECTION_RELEASED;
110     little_endian_store_16(event, pos, avdtp_cid);
111     pos += 2;
112     event[pos++] = local_seid;
113 
114     btstack_packet_handler_t packet_handler = avdtp_packet_handler_for_stream_endpoint(stream_endpoint);
115     (*packet_handler)(HCI_EVENT_PACKET, 0, event, sizeof(event));
116 }
117 
118 void avdtp_streaming_emit_can_send_media_packet_now(avdtp_stream_endpoint_t *stream_endpoint, uint16_t sequence_number) {
119     uint8_t event[8];
120     int pos = 0;
121     event[pos++] = HCI_EVENT_AVDTP_META;
122     event[pos++] = sizeof(event) - 2;
123     event[pos++] = AVDTP_SUBEVENT_STREAMING_CAN_SEND_MEDIA_PACKET_NOW;
124     little_endian_store_16(event, pos, stream_endpoint->connection->avdtp_cid);
125     pos += 2;
126     event[pos++] = avdtp_local_seid(stream_endpoint);
127     little_endian_store_16(event, pos, sequence_number);
128     pos += 2;
129 
130     btstack_packet_handler_t packet_handler = avdtp_packet_handler_for_stream_endpoint(stream_endpoint);
131     (*packet_handler)(HCI_EVENT_PACKET, 0, event, sizeof(event));
132 }
133 
134 btstack_linked_list_t * avdtp_get_stream_endpoints(void){
135     return &stream_endpoints;
136 }
137 
138 static avdtp_connection_t * avdtp_get_connection_for_bd_addr(bd_addr_t addr){
139     btstack_linked_list_iterator_t it;
140     btstack_linked_list_iterator_init(&it, &connections);
141     while (btstack_linked_list_iterator_has_next(&it)){
142         avdtp_connection_t * connection = (avdtp_connection_t *)btstack_linked_list_iterator_next(&it);
143         if (memcmp(addr, connection->remote_addr, 6) != 0) continue;
144         return connection;
145     }
146     return NULL;
147 }
148 
149  avdtp_connection_t * avdtp_get_connection_for_avdtp_cid(uint16_t avdtp_cid){
150     btstack_linked_list_iterator_t it;
151     btstack_linked_list_iterator_init(&it, &connections);
152     while (btstack_linked_list_iterator_has_next(&it)){
153         avdtp_connection_t * connection = (avdtp_connection_t *)btstack_linked_list_iterator_next(&it);
154         if (connection->avdtp_cid != avdtp_cid) continue;
155         return connection;
156     }
157     return NULL;
158 }
159 
160 
161 avdtp_stream_endpoint_t * avdtp_get_stream_endpoint_for_seid(uint16_t seid){
162     btstack_linked_list_iterator_t it;
163     btstack_linked_list_iterator_init(&it, avdtp_get_stream_endpoints());
164     while (btstack_linked_list_iterator_has_next(&it)){
165         avdtp_stream_endpoint_t * stream_endpoint = (avdtp_stream_endpoint_t *)btstack_linked_list_iterator_next(&it);
166         if (stream_endpoint->sep.seid == seid){
167             return stream_endpoint;
168         }
169     }
170     return NULL;
171 }
172 
173 avdtp_connection_t * avdtp_get_connection_for_l2cap_signaling_cid(uint16_t l2cap_cid){
174     btstack_linked_list_iterator_t it;
175     btstack_linked_list_iterator_init(&it, &connections);
176     while (btstack_linked_list_iterator_has_next(&it)){
177         avdtp_connection_t * connection = (avdtp_connection_t *)btstack_linked_list_iterator_next(&it);
178         if (connection->l2cap_signaling_cid != l2cap_cid) continue;
179         return connection;
180     }
181     return NULL;
182 }
183 
184 static avdtp_stream_endpoint_t * avdtp_get_stream_endpoint_for_l2cap_cid(uint16_t l2cap_cid){
185     btstack_linked_list_iterator_t it;
186     btstack_linked_list_iterator_init(&it, avdtp_get_stream_endpoints());
187     while (btstack_linked_list_iterator_has_next(&it)){
188         avdtp_stream_endpoint_t * stream_endpoint = (avdtp_stream_endpoint_t *)btstack_linked_list_iterator_next(&it);
189         if (stream_endpoint->l2cap_media_cid == l2cap_cid){
190             return stream_endpoint;
191         }
192         if (stream_endpoint->l2cap_reporting_cid == l2cap_cid){
193             return stream_endpoint;
194         }
195         if (stream_endpoint->l2cap_recovery_cid == l2cap_cid){
196             return stream_endpoint;
197         }
198     }
199     return NULL;
200 }
201 
202 static avdtp_stream_endpoint_t * avdtp_get_stream_endpoint_for_signaling_cid(uint16_t l2cap_cid){
203     btstack_linked_list_iterator_t it;
204     btstack_linked_list_iterator_init(&it, avdtp_get_stream_endpoints());
205     while (btstack_linked_list_iterator_has_next(&it)){
206         avdtp_stream_endpoint_t * stream_endpoint = (avdtp_stream_endpoint_t *)btstack_linked_list_iterator_next(&it);
207         if (stream_endpoint->connection){
208             if (stream_endpoint->connection->l2cap_signaling_cid == l2cap_cid){
209                 return stream_endpoint;
210             }
211         }
212     }
213     return NULL;
214 }
215 
216 avdtp_stream_endpoint_t * avdtp_get_stream_endpoint_with_seid(uint8_t seid){
217     btstack_linked_list_iterator_t it;
218     btstack_linked_list_iterator_init(&it, avdtp_get_stream_endpoints());
219     while (btstack_linked_list_iterator_has_next(&it)){
220         avdtp_stream_endpoint_t * stream_endpoint = (avdtp_stream_endpoint_t *)btstack_linked_list_iterator_next(&it);
221         if (stream_endpoint->sep.seid == seid){
222             return stream_endpoint;
223         }
224     }
225     return NULL;
226 }
227 
228 avdtp_stream_endpoint_t * avdtp_get_stream_endpoint_associated_with_acp_seid(uint16_t acp_seid){
229     btstack_linked_list_iterator_t it;
230     btstack_linked_list_iterator_init(&it, avdtp_get_stream_endpoints());
231     while (btstack_linked_list_iterator_has_next(&it)){
232         avdtp_stream_endpoint_t * stream_endpoint = (avdtp_stream_endpoint_t *)btstack_linked_list_iterator_next(&it);
233         if (stream_endpoint->remote_sep.seid == acp_seid){
234             return stream_endpoint;
235         }
236     }
237     return NULL;
238 }
239 
240 static uint16_t avdtp_get_next_initiator_transaction_label(void){
241     initiator_transaction_id_counter++;
242     if (initiator_transaction_id_counter == 0){
243         initiator_transaction_id_counter = 1;
244     }
245     return initiator_transaction_id_counter;
246 }
247 
248 static avdtp_connection_t * avdtp_create_connection(bd_addr_t remote_addr, uint16_t cid){
249     avdtp_connection_t * connection = btstack_memory_avdtp_connection_get();
250     if (!connection){
251         log_error("Not enough memory to create connection");
252         return NULL;
253     }
254     connection->state = AVDTP_SIGNALING_CONNECTION_IDLE;
255     connection->initiator_transaction_label = avdtp_get_next_initiator_transaction_label();
256     connection->configuration_state = AVDTP_CONFIGURATION_STATE_IDLE;
257     connection->avdtp_cid = cid;
258     (void)memcpy(connection->remote_addr, remote_addr, 6);
259 
260     btstack_linked_list_add(&connections, (btstack_linked_item_t *) connection);
261     return connection;
262 }
263 
264 static uint16_t avdtp_get_next_cid(void){
265     if (avdtp_cid_counter == 0xffff) {
266         avdtp_cid_counter = 1;
267     } else {
268         avdtp_cid_counter++;
269     }
270     return avdtp_cid_counter;
271 }
272 
273 static uint16_t avdtp_get_next_local_seid(void){
274     if (stream_endpoints_id_counter == 0xffff) {
275         stream_endpoints_id_counter = 1;
276     } else {
277         stream_endpoints_id_counter++;
278     }
279     return stream_endpoints_id_counter;
280 }
281 
282 static uint8_t avdtp_start_sdp_query(btstack_packet_handler_t packet_handler, avdtp_connection_t * connection) {
283     connection->avdtp_l2cap_psm = 0;
284     connection->avdtp_version  = 0;
285     connection->sink_supported = false;
286     connection->source_supported = false;
287     sdp_query_context_avdtp_cid = connection->avdtp_cid;
288 
289     return sdp_client_query_uuid16(packet_handler, (uint8_t *) connection->remote_addr, BLUETOOTH_PROTOCOL_AVDTP);
290 }
291 
292 uint8_t avdtp_connect(bd_addr_t remote, avdtp_role_t role, uint16_t * avdtp_cid){
293     // TODO: implement delayed SDP query
294     if (sdp_client_ready() == 0){
295         return ERROR_CODE_COMMAND_DISALLOWED;
296     }
297 
298     avdtp_connection_t * connection = avdtp_get_connection_for_bd_addr(remote);
299     if (connection){
300         return ERROR_CODE_COMMAND_DISALLOWED;
301     }
302 
303     uint16_t cid = avdtp_get_next_cid();
304     if (avdtp_cid != NULL) {
305         *avdtp_cid = cid;
306     }
307 
308     connection = avdtp_create_connection(remote, cid);
309     if (!connection) return BTSTACK_MEMORY_ALLOC_FAILED;
310 
311     connection->avdtp_cid = cid;
312 
313     switch (role){
314         case AVDTP_ROLE_SOURCE:
315             connection->state = AVDTP_SIGNALING_W4_SDP_QUERY_FOR_REMOTE_SINK_COMPLETE;
316             break;
317         case AVDTP_ROLE_SINK:
318             connection->state = AVDTP_SIGNALING_W4_SDP_QUERY_FOR_REMOTE_SOURCE_COMPLETE;
319             break;
320         default:
321             return ERROR_CODE_COMMAND_DISALLOWED;
322     }
323     return avdtp_start_sdp_query(&avdtp_handle_sdp_client_query_result, connection);
324 }
325 
326 
327 void avdtp_register_sink_packet_handler(btstack_packet_handler_t callback){
328     btstack_assert(callback != NULL);
329     avdtp_sink_callback = callback;
330 }
331 
332 void avdtp_register_source_packet_handler(btstack_packet_handler_t callback){
333     btstack_assert(callback != NULL);
334     avdtp_source_callback = callback;
335 }
336 
337 void avdtp_register_media_transport_category(avdtp_stream_endpoint_t * stream_endpoint){
338     if (!stream_endpoint){
339         log_error("Stream endpoint with given seid is not registered.");
340         return;
341     }
342     uint16_t bitmap = store_bit16(stream_endpoint->sep.registered_service_categories, AVDTP_MEDIA_TRANSPORT, 1);
343     stream_endpoint->sep.registered_service_categories = bitmap;
344 }
345 
346 void avdtp_register_reporting_category(avdtp_stream_endpoint_t * stream_endpoint){
347     if (!stream_endpoint){
348         log_error("Stream endpoint with given seid is not registered.");
349         return;
350     }
351     uint16_t bitmap = store_bit16(stream_endpoint->sep.registered_service_categories, AVDTP_REPORTING, 1);
352     stream_endpoint->sep.registered_service_categories = bitmap;
353 }
354 
355 void avdtp_register_delay_reporting_category(avdtp_stream_endpoint_t * stream_endpoint){
356     if (!stream_endpoint){
357         log_error("Stream endpoint with given seid is not registered.");
358         return;
359     }
360     uint16_t bitmap = store_bit16(stream_endpoint->sep.registered_service_categories, AVDTP_DELAY_REPORTING, 1);
361     stream_endpoint->sep.registered_service_categories = bitmap;
362 }
363 
364 void avdtp_register_recovery_category(avdtp_stream_endpoint_t * stream_endpoint, uint8_t maximum_recovery_window_size, uint8_t maximum_number_media_packets){
365     if (!stream_endpoint){
366         log_error("Stream endpoint with given seid is not registered.");
367         return;
368     }
369     uint16_t bitmap = store_bit16(stream_endpoint->sep.registered_service_categories, AVDTP_RECOVERY, 1);
370     stream_endpoint->sep.registered_service_categories = bitmap;
371     stream_endpoint->sep.capabilities.recovery.recovery_type = 0x01; // 0x01 = RFC2733
372     stream_endpoint->sep.capabilities.recovery.maximum_recovery_window_size = maximum_recovery_window_size;
373     stream_endpoint->sep.capabilities.recovery.maximum_number_media_packets = maximum_number_media_packets;
374 }
375 
376 void avdtp_register_content_protection_category(avdtp_stream_endpoint_t * stream_endpoint, uint16_t cp_type, const uint8_t * cp_type_value, uint8_t cp_type_value_len){
377     if (!stream_endpoint){
378         log_error("Stream endpoint with given seid is not registered.");
379         return;
380     }
381     uint16_t bitmap = store_bit16(stream_endpoint->sep.registered_service_categories, AVDTP_CONTENT_PROTECTION, 1);
382     stream_endpoint->sep.registered_service_categories = bitmap;
383     stream_endpoint->sep.capabilities.content_protection.cp_type = cp_type;
384     (void)memcpy(stream_endpoint->sep.capabilities.content_protection.cp_type_value,
385                  cp_type_value,
386                  btstack_min(cp_type_value_len, AVDTP_MAX_CONTENT_PROTECTION_TYPE_VALUE_LEN));
387     stream_endpoint->sep.capabilities.content_protection.cp_type_value_len = btstack_min(cp_type_value_len, AVDTP_MAX_CONTENT_PROTECTION_TYPE_VALUE_LEN);
388 }
389 
390 void avdtp_register_header_compression_category(avdtp_stream_endpoint_t * stream_endpoint, uint8_t back_ch, uint8_t media, uint8_t recovery){
391     if (!stream_endpoint){
392         log_error("Stream endpoint with given seid is not registered.");
393         return;
394     }
395     uint16_t bitmap = store_bit16(stream_endpoint->sep.registered_service_categories, AVDTP_HEADER_COMPRESSION, 1);
396     stream_endpoint->sep.registered_service_categories = bitmap;
397     stream_endpoint->sep.capabilities.header_compression.back_ch = back_ch;
398     stream_endpoint->sep.capabilities.header_compression.media = media;
399     stream_endpoint->sep.capabilities.header_compression.recovery = recovery;
400 }
401 
402 void avdtp_register_media_codec_category(avdtp_stream_endpoint_t * stream_endpoint, avdtp_media_type_t media_type, avdtp_media_codec_type_t media_codec_type, uint8_t * media_codec_info, uint16_t media_codec_info_len){
403     if (!stream_endpoint){
404         log_error("Stream endpoint with given seid is not registered.");
405         return;
406     }
407     uint16_t bitmap = store_bit16(stream_endpoint->sep.registered_service_categories, AVDTP_MEDIA_CODEC, 1);
408     stream_endpoint->sep.registered_service_categories = bitmap;
409     stream_endpoint->sep.capabilities.media_codec.media_type = media_type;
410     stream_endpoint->sep.capabilities.media_codec.media_codec_type = media_codec_type;
411     stream_endpoint->sep.capabilities.media_codec.media_codec_information = media_codec_info;
412     stream_endpoint->sep.capabilities.media_codec.media_codec_information_len = media_codec_info_len;
413 }
414 
415 void avdtp_register_multiplexing_category(avdtp_stream_endpoint_t * stream_endpoint, uint8_t fragmentation){
416     if (!stream_endpoint){
417         log_error("Stream endpoint with given seid is not registered.");
418         return;
419     }
420     uint16_t bitmap = store_bit16(stream_endpoint->sep.registered_service_categories, AVDTP_MULTIPLEXING, 1);
421     stream_endpoint->sep.registered_service_categories = bitmap;
422     stream_endpoint->sep.capabilities.multiplexing_mode.fragmentation = fragmentation;
423 }
424 
425 void avdtp_register_media_handler(void (*callback)(uint8_t local_seid, uint8_t *packet, uint16_t size)){
426     avdtp_sink_handle_media_data = callback;
427 }
428 
429 /* START: tracking can send now requests pro l2cap cid */
430 void avdtp_handle_can_send_now(avdtp_connection_t * connection, uint16_t l2cap_cid, avdtp_context_t * context){
431     if (connection->wait_to_send_acceptor){
432         log_debug("call avdtp_acceptor_stream_config_subsm_run");
433         connection->wait_to_send_acceptor = 0;
434         avdtp_acceptor_stream_config_subsm_run(connection, context);
435     } else if (connection->wait_to_send_initiator){
436         log_debug("call avdtp_initiator_stream_config_subsm_run");
437         connection->wait_to_send_initiator = 0;
438         avdtp_initiator_stream_config_subsm_run(connection, context);
439     }
440 
441     // re-register
442     bool more_to_send = connection->wait_to_send_acceptor || connection->wait_to_send_initiator;
443     log_debug("ask for more to send %d: acc-%d, ini-%d",  more_to_send, connection->wait_to_send_acceptor, connection->wait_to_send_initiator);
444 
445     if (more_to_send){
446         l2cap_request_can_send_now_event(l2cap_cid);
447     }
448 }
449 /* END: tracking can send now requests pro l2cap cid */
450 
451 
452 avdtp_stream_endpoint_t * avdtp_create_stream_endpoint(avdtp_sep_type_t sep_type, avdtp_media_type_t media_type){
453     avdtp_stream_endpoint_t * stream_endpoint = btstack_memory_avdtp_stream_endpoint_get();
454     if (!stream_endpoint){
455         log_error("Not enough memory to create stream endpoint");
456         return NULL;
457     }
458     stream_endpoint->sep.seid = avdtp_get_next_local_seid();
459     stream_endpoint->sep.media_type = media_type;
460     stream_endpoint->sep.type = sep_type;
461     btstack_linked_list_add(avdtp_get_stream_endpoints(), (btstack_linked_item_t *) stream_endpoint);
462     return stream_endpoint;
463 }
464 
465 static void handle_l2cap_data_packet_for_signaling_connection(avdtp_connection_t * connection, uint8_t *packet, uint16_t size, avdtp_context_t * context){
466     if (size < 2) return;
467 
468     uint16_t offset;
469     avdtp_message_type_t message_type = avdtp_get_signaling_packet_type(packet);
470     switch (message_type){
471         case AVDTP_CMD_MSG:
472             offset = avdtp_read_signaling_header(&connection->acceptor_signaling_packet, packet, size);
473             avdtp_acceptor_stream_config_subsm(connection, packet, size, offset, context);
474             break;
475         default:
476             offset = avdtp_read_signaling_header(&connection->initiator_signaling_packet, packet, size);
477             avdtp_initiator_stream_config_subsm(connection, packet, size, offset, context);
478             break;
479     }
480 }
481 
482 static void avdtp_handle_sdp_client_query_attribute_value(avdtp_connection_t * connection, uint8_t *packet){
483     des_iterator_t des_list_it;
484     des_iterator_t prot_it;
485 
486     // Handle new SDP record
487     if (sdp_event_query_attribute_byte_get_record_id(packet) != record_id) {
488         record_id = sdp_event_query_attribute_byte_get_record_id(packet);
489         // log_info("SDP Record: Nr: %d", record_id);
490     }
491 
492     if (sdp_event_query_attribute_byte_get_attribute_length(packet) <= attribute_value_buffer_size) {
493         attribute_value[sdp_event_query_attribute_byte_get_data_offset(packet)] = sdp_event_query_attribute_byte_get_data(packet);
494 
495         if ((uint16_t)(sdp_event_query_attribute_byte_get_data_offset(packet)+1) == sdp_event_query_attribute_byte_get_attribute_length(packet)) {
496 
497             switch(sdp_event_query_attribute_byte_get_attribute_id(packet)) {
498 
499                 case BLUETOOTH_ATTRIBUTE_SERVICE_CLASS_ID_LIST:
500                     if (de_get_element_type(attribute_value) != DE_DES) break;
501                     for (des_iterator_init(&des_list_it, attribute_value); des_iterator_has_more(&des_list_it); des_iterator_next(&des_list_it)) {
502                         uint8_t * element = des_iterator_get_element(&des_list_it);
503                         if (de_get_element_type(element) != DE_UUID) continue;
504                         uint32_t uuid = de_get_uuid32(element);
505                         switch (uuid){
506                             case BLUETOOTH_SERVICE_CLASS_AUDIO_SOURCE:
507                                 connection->source_supported = true;
508                                 log_info("source_supported");
509                                 break;
510                             case BLUETOOTH_SERVICE_CLASS_AUDIO_SINK:
511                                 connection->sink_supported = true;
512                                 log_info("sink_supported");
513                                 break;
514                             default:
515                                 break;
516                         }
517                     }
518                     break;
519 
520                 case BLUETOOTH_ATTRIBUTE_PROTOCOL_DESCRIPTOR_LIST:
521                     // log_info("SDP Attribute: 0x%04x", sdp_event_query_attribute_byte_get_attribute_id(packet));
522                     for (des_iterator_init(&des_list_it, attribute_value); des_iterator_has_more(&des_list_it); des_iterator_next(&des_list_it)) {
523                         uint8_t       *des_element;
524                         uint8_t       *element;
525                         uint32_t       uuid;
526 
527                         if (des_iterator_get_type(&des_list_it) != DE_DES) continue;
528 
529                         des_element = des_iterator_get_element(&des_list_it);
530                         des_iterator_init(&prot_it, des_element);
531                         element = des_iterator_get_element(&prot_it);
532 
533                         if (de_get_element_type(element) != DE_UUID) continue;
534 
535                         uuid = de_get_uuid32(element);
536                         des_iterator_next(&prot_it);
537                         // we assume that the even if there are both roles supported, remote device uses the same psm and avdtp version for both
538                         switch (uuid){
539                             case BLUETOOTH_PROTOCOL_L2CAP:
540                                 if (!des_iterator_has_more(&prot_it)) continue;
541                                 de_element_get_uint16(des_iterator_get_element(&prot_it), &connection->avdtp_l2cap_psm);
542                                 break;
543                             case BLUETOOTH_PROTOCOL_AVDTP:
544                                 if (!des_iterator_has_more(&prot_it)) continue;
545                                 de_element_get_uint16(des_iterator_get_element(&prot_it), &connection->avdtp_version);
546                                 break;
547                             default:
548                                 break;
549                         }
550                     }
551                     break;
552 
553                 default:
554                     break;
555             }
556         }
557     } else {
558         log_error("SDP attribute value buffer size exceeded: available %d, required %d", attribute_value_buffer_size, sdp_event_query_attribute_byte_get_attribute_length(packet));
559     }
560 
561 }
562 
563 static void avdtp_finalize_connection(avdtp_connection_t * connection){
564     btstack_run_loop_remove_timer(&connection->retry_timer);
565     btstack_linked_list_remove(&connections, (btstack_linked_item_t*) connection);
566     btstack_memory_avdtp_connection_free(connection);
567 }
568 
569 static void avdtp_handle_sdp_query_failed(avdtp_connection_t * connection, uint8_t status){
570     printf("avdtp_handle_sdp_query_failed \n");
571     switch (connection->state){
572         case AVDTP_SIGNALING_W4_SDP_QUERY_FOR_REMOTE_SINK_COMPLETE:
573             avdtp_signaling_emit_connection_established(avdtp_source_callback, connection->avdtp_cid, connection->remote_addr, status);
574             break;
575         case AVDTP_SIGNALING_W4_SDP_QUERY_FOR_REMOTE_SOURCE_COMPLETE:
576             avdtp_signaling_emit_connection_established(avdtp_sink_callback, connection->avdtp_cid, connection->remote_addr, status);
577             break;
578         default:
579             return;
580     }
581     avdtp_finalize_connection(connection);
582     sdp_query_context_avdtp_cid = 0;
583     log_info("SDP query failed with status 0x%02x.", status);
584 }
585 
586 static void avdtp_handle_sdp_query_succeeded(avdtp_connection_t * connection){
587     printf("avdtp_handle_sdp_query_succeeded \n");
588     connection->state = AVDTP_SIGNALING_CONNECTION_W4_L2CAP_CONNECTED;
589 }
590 
591 static void avdtp_handle_sdp_client_query_result(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
592     UNUSED(packet_type);
593     UNUSED(channel);
594     UNUSED(size);
595 
596     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(sdp_query_context_avdtp_cid);
597     if (!connection) {
598         log_error("SDP query, connection with 0x%02x cid not found", sdp_query_context_avdtp_cid);
599         return;
600     }
601 
602     uint8_t status;
603     bool query_succeded = false;
604 
605     switch (connection->state){
606         case AVDTP_SIGNALING_W4_SDP_QUERY_FOR_REMOTE_SINK_COMPLETE:
607             switch (hci_event_packet_get_type(packet)){
608                 case SDP_EVENT_QUERY_ATTRIBUTE_VALUE:
609                     avdtp_handle_sdp_client_query_attribute_value(connection, packet);
610                     return;
611                 case SDP_EVENT_QUERY_COMPLETE:
612                     status = sdp_event_query_complete_get_status(packet);
613                     if (status != ERROR_CODE_SUCCESS) break;
614                     if (!connection->sink_supported) break;
615                     if (connection->avdtp_l2cap_psm == 0) break;
616                     query_succeded = true;
617                     break;
618                 default:
619                     btstack_assert(false);
620                     break;
621             }
622             break;
623         case AVDTP_SIGNALING_W4_SDP_QUERY_FOR_REMOTE_SOURCE_COMPLETE:
624             switch (hci_event_packet_get_type(packet)){
625                 case SDP_EVENT_QUERY_ATTRIBUTE_VALUE:
626                     avdtp_handle_sdp_client_query_attribute_value(connection, packet);
627                     return;
628                 case SDP_EVENT_QUERY_COMPLETE:
629                     status = sdp_event_query_complete_get_status(packet);
630                     if (status != ERROR_CODE_SUCCESS) break;
631                     if (!connection->source_supported) break;
632                     if (connection->avdtp_l2cap_psm == 0) break;
633                     query_succeded = true;
634                     break;
635                 default:
636                     btstack_assert(false);
637                     break;
638             }
639             break;
640         default:
641             // bail out, we must have had an incoming connection in the meantime;
642             return;
643     }
644 
645     if (query_succeded){
646         avdtp_handle_sdp_query_succeeded(connection);
647         l2cap_create_channel(avdtp_packet_handler, connection->remote_addr, connection->avdtp_l2cap_psm, l2cap_max_mtu(), NULL);
648     } else {
649         avdtp_handle_sdp_query_failed(connection, status);
650     }
651 }
652 
653 static avdtp_connection_t * avdtp_handle_incoming_connection(avdtp_connection_t * connection, bd_addr_t event_addr, uint16_t local_cid){
654     if (connection == NULL){
655         uint16_t cid = avdtp_get_next_cid();
656         connection = avdtp_create_connection(event_addr, cid);
657     }
658 
659     if (connection) {
660         connection->state = AVDTP_SIGNALING_CONNECTION_W4_L2CAP_CONNECTED;
661         connection->l2cap_signaling_cid = local_cid;
662         btstack_run_loop_remove_timer(&connection->retry_timer);
663     }
664     return connection;
665 }
666 
667 static avdtp_context_t * avdtp_get_active_contex(void){
668     // assume only one context is active
669     avdtp_context_t * context = NULL;
670     if (avdtp_sink_context != NULL){
671         context = avdtp_sink_context;
672     } else {
673         context = avdtp_source_context;
674     }
675     btstack_assert(context != NULL);
676     return context;
677 }
678 
679 static void avdtp_retry_timer_timeout_handler(btstack_timer_source_t * timer){
680     uint16_t avdtp_cid = (uint16_t)(uintptr_t) btstack_run_loop_get_timer_context(timer);
681 
682     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
683     if (connection == NULL) return;
684 
685     if (connection->state == AVDTP_SIGNALING_CONNECTION_W2_L2CAP_RETRY){
686         connection->state = AVDTP_SIGNALING_CONNECTION_W4_L2CAP_CONNECTED;
687         l2cap_create_channel(&avdtp_packet_handler, connection->remote_addr, connection->avdtp_l2cap_psm, l2cap_max_mtu(), NULL);
688     }
689 }
690 
691 static void avdtp_retry_timer_start(avdtp_connection_t * connection){
692     btstack_run_loop_set_timer_handler(&connection->retry_timer, avdtp_retry_timer_timeout_handler);
693     btstack_run_loop_set_timer_context(&connection->retry_timer, (void *)(uintptr_t)connection->avdtp_cid);
694 
695     // add some jitter/randomness to reconnect delay
696     uint32_t timeout = 100 + (btstack_run_loop_get_time_ms() & 0x7F);
697     btstack_run_loop_set_timer(&connection->retry_timer, timeout);
698     btstack_run_loop_add_timer(&connection->retry_timer);
699 }
700 
701 
702 void avdtp_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
703     bd_addr_t event_addr;
704     uint16_t psm;
705     uint16_t local_cid;
706     uint8_t  status;
707     uint16_t l2cap_mtu;
708 
709     bool accept_streaming_connection;
710     bool outoing_signaling_active;
711     bool decline_connection;
712 
713     avdtp_stream_endpoint_t * stream_endpoint = NULL;
714     avdtp_connection_t * connection = NULL;
715 
716     avdtp_context_t * context = avdtp_get_active_contex();
717 
718     switch (packet_type) {
719         case L2CAP_DATA_PACKET:
720             connection = avdtp_get_connection_for_l2cap_signaling_cid(channel);
721             if (connection){
722                 handle_l2cap_data_packet_for_signaling_connection(connection, packet, size, context);
723                 break;
724             }
725 
726             stream_endpoint = avdtp_get_stream_endpoint_for_l2cap_cid(channel);
727             if (!stream_endpoint){
728                 if (!connection) break;
729                 handle_l2cap_data_packet_for_signaling_connection(connection, packet, size, context);
730                 break;
731             }
732 
733             if (stream_endpoint->connection){
734                 if (channel == stream_endpoint->connection->l2cap_signaling_cid){
735                     handle_l2cap_data_packet_for_signaling_connection(stream_endpoint->connection, packet, size, context);
736                     break;
737                 }
738             }
739 
740             if (channel == stream_endpoint->l2cap_media_cid){
741                 btstack_assert(avdtp_sink_handle_media_data);
742                 (*avdtp_sink_handle_media_data)(avdtp_local_seid(stream_endpoint), packet, size);
743                 break;
744             }
745 
746             if (channel == stream_endpoint->l2cap_reporting_cid){
747                 log_info("L2CAP_DATA_PACKET for reporting: NOT IMPLEMENTED");
748             } else if (channel == stream_endpoint->l2cap_recovery_cid){
749                 log_info("L2CAP_DATA_PACKET for recovery: NOT IMPLEMENTED");
750             } else {
751                 log_error("avdtp packet handler L2CAP_DATA_PACKET: local cid 0x%02x not found", channel);
752             }
753             break;
754 
755         case HCI_EVENT_PACKET:
756             switch (hci_event_packet_get_type(packet)) {
757 
758                 case L2CAP_EVENT_INCOMING_CONNECTION:
759                     l2cap_event_incoming_connection_get_address(packet, event_addr);
760                     local_cid = l2cap_event_incoming_connection_get_local_cid(packet);
761 
762                     outoing_signaling_active = false;
763                     accept_streaming_connection = false;
764 
765                     connection = avdtp_get_connection_for_bd_addr(event_addr);
766                     if (connection != NULL){
767                         switch (connection->state){
768                             case AVDTP_SIGNALING_CONNECTION_W4_L2CAP_DISCONNECTED:
769                             case AVDTP_SIGNALING_CONNECTION_W4_L2CAP_CONNECTED:
770                                 outoing_signaling_active = true;
771                                 connection->incoming_declined = true;
772                                 break;
773                             case AVDTP_SIGNALING_CONNECTION_OPENED:
774                                 outoing_signaling_active = true;
775                                 accept_streaming_connection = true;
776                                 break;
777                             default:
778                                 break;
779                         }
780                     }
781                     log_info("incoming: %s, outoing_signaling_active %d, accept_streaming_connection %d",
782                         bd_addr_to_str(event_addr), outoing_signaling_active, accept_streaming_connection);
783 
784                     decline_connection = outoing_signaling_active && !accept_streaming_connection;
785                     if (outoing_signaling_active == false){
786                         connection = avdtp_handle_incoming_connection(connection, event_addr, local_cid);
787                         if (connection == NULL){
788                             decline_connection = true;
789                         }
790                     } else if (accept_streaming_connection){
791                         if ((connection == NULL) || (connection->configuration_state != AVDTP_CONFIGURATION_STATE_REMOTE_CONFIGURED)) {
792                             decline_connection = true;
793                         } else {
794                             // now, we're only dealing with media connections that are created by remote side - we're acceptor here
795                             stream_endpoint = avdtp_get_stream_endpoint_with_seid(connection->acceptor_local_seid);
796                             if ((stream_endpoint == NULL) || (stream_endpoint->l2cap_media_cid != 0) ) {
797                                 decline_connection = true;
798                             }
799                         }
800                     }
801 
802                     if (decline_connection){
803                         l2cap_decline_connection(local_cid);
804                     } else {
805                         l2cap_accept_connection(local_cid);
806                     }
807                     break;
808 
809                 case L2CAP_EVENT_CHANNEL_OPENED:
810                     btstack_assert(context != NULL);
811 
812                     psm = l2cap_event_channel_opened_get_psm(packet);
813                     if (psm != BLUETOOTH_PSM_AVDTP){
814                         log_info("Unexpected PSM - Not implemented yet, avdtp sink: L2CAP_EVENT_CHANNEL_OPENED ");
815                         return;
816                     }
817 
818                     status = l2cap_event_channel_opened_get_status(packet);
819                     // inform about new l2cap connection
820                     l2cap_event_channel_opened_get_address(packet, event_addr);
821                     local_cid = l2cap_event_channel_opened_get_local_cid(packet);
822                     l2cap_mtu = l2cap_event_channel_opened_get_remote_mtu(packet);
823                     connection = avdtp_get_connection_for_bd_addr(event_addr);
824                     if (connection == NULL){
825                         log_info("L2CAP_EVENT_CHANNEL_OPENED: no connection found for %s", bd_addr_to_str(event_addr));
826                         break;
827                     }
828 
829                     switch (connection->state){
830                         case AVDTP_SIGNALING_CONNECTION_W4_L2CAP_CONNECTED:
831                             switch (status){
832                                 case ERROR_CODE_SUCCESS:
833                                     connection->l2cap_signaling_cid = local_cid;
834                                     connection->incoming_declined = false;
835                                     connection->l2cap_mtu = l2cap_mtu;
836                                     connection->state = AVDTP_SIGNALING_CONNECTION_OPENED;
837                                     log_info("Connection opened l2cap_signaling_cid 0x%02x, avdtp_cid 0x%02x", connection->l2cap_signaling_cid, connection->avdtp_cid);
838                                     avdtp_signaling_emit_connection_established(context->avdtp_callback, connection->avdtp_cid, event_addr, status);
839                                     return;
840                                 case L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_RESOURCES:
841                                     if (connection->incoming_declined == true) {
842                                         log_info("Connection was declined, and the outgoing failed");
843                                         connection->state = AVDTP_SIGNALING_CONNECTION_W2_L2CAP_RETRY;
844                                         connection->incoming_declined = false;
845                                         avdtp_retry_timer_start(connection);
846                                         return;
847                                     }
848                                     break;
849                                 default:
850                                     log_info("Connection to %s failed. status code 0x%02x", bd_addr_to_str(event_addr), status);
851                                     break;
852                             }
853                             avdtp_finalize_connection(connection);
854                             avdtp_signaling_emit_connection_established(context->avdtp_callback, connection->avdtp_cid, event_addr, status);
855                             break;
856 
857                         case AVDTP_SIGNALING_CONNECTION_OPENED:
858                             stream_endpoint = avdtp_get_stream_endpoint_for_signaling_cid(connection->l2cap_signaling_cid);
859                             if (!stream_endpoint){
860                                 log_info("L2CAP_EVENT_CHANNEL_OPENED: stream_endpoint not found for signaling cid 0x%02x", connection->l2cap_signaling_cid);
861                                 return;
862                             }
863                             if (status != ERROR_CODE_SUCCESS){
864                                 log_info("AVDTP_STREAM_ENDPOINT_OPENED failed with status %d, avdtp cid 0x%02x, l2cap_media_cid 0x%02x, local seid %d, remote seid %d", status, connection->avdtp_cid, stream_endpoint->l2cap_media_cid, avdtp_local_seid(stream_endpoint), avdtp_remote_seid(stream_endpoint));
865                                 stream_endpoint->state = AVDTP_STREAM_ENDPOINT_IDLE;
866                                 avdtp_streaming_emit_connection_established(stream_endpoint, status);
867                                 break;
868                             }
869                             switch (stream_endpoint->state){
870                                 case AVDTP_STREAM_ENDPOINT_W4_L2CAP_FOR_MEDIA_CONNECTED:
871                                     stream_endpoint->state = AVDTP_STREAM_ENDPOINT_OPENED;
872                                     stream_endpoint->l2cap_media_cid = l2cap_event_channel_opened_get_local_cid(packet);
873                                     stream_endpoint->media_con_handle = l2cap_event_channel_opened_get_handle(packet);
874 
875                                     log_info("AVDTP_STREAM_ENDPOINT_OPENED, avdtp cid 0x%02x, l2cap_media_cid 0x%02x, local seid %d, remote seid %d", connection->avdtp_cid, stream_endpoint->l2cap_media_cid, avdtp_local_seid(stream_endpoint), avdtp_remote_seid(stream_endpoint));
876                                     avdtp_streaming_emit_connection_established(stream_endpoint, ERROR_CODE_SUCCESS);
877                                     break;
878                                 default:
879                                     log_info("AVDTP_STREAM_ENDPOINT_OPENED failed - stream endpoint in wrong state %d, avdtp cid 0x%02x, l2cap_media_cid 0x%02x, local seid %d, remote seid %d", stream_endpoint->state, connection->avdtp_cid, stream_endpoint->l2cap_media_cid, avdtp_local_seid(stream_endpoint), avdtp_remote_seid(stream_endpoint));
880                                     avdtp_streaming_emit_connection_established(stream_endpoint, AVDTP_STREAM_ENDPOINT_IN_WRONG_STATE);
881                                     break;
882                             }
883                             break;
884 
885                         default:
886                             log_info("L2CAP connection to %s ignored: status code 0x%02x, connection state %d", bd_addr_to_str(event_addr), status, connection->state);
887                             break;
888                     }
889                     break;
890 
891                 case L2CAP_EVENT_CHANNEL_CLOSED:
892                     local_cid = l2cap_event_channel_closed_get_local_cid(packet);
893                     stream_endpoint = avdtp_get_stream_endpoint_for_l2cap_cid(local_cid);
894                     connection = avdtp_get_connection_for_l2cap_signaling_cid(local_cid);
895 
896                     log_info("Received L2CAP_EVENT_CHANNEL_CLOSED, cid 0x%2x, connection %p, stream_endpoint %p", local_cid, connection, stream_endpoint);
897 
898                     if (stream_endpoint){
899                         if (stream_endpoint->l2cap_media_cid == local_cid){
900                             connection = stream_endpoint->connection;
901                             if (connection) {
902                                 avdtp_streaming_emit_connection_released(stream_endpoint,
903                                                                          connection->avdtp_cid,
904                                                                          avdtp_local_seid(stream_endpoint));
905                             }
906                             avdtp_reset_stream_endpoint(stream_endpoint);
907                             break;
908                         }
909                         if (stream_endpoint->l2cap_recovery_cid == local_cid){
910                             log_info("L2CAP_EVENT_CHANNEL_CLOSED recovery cid 0x%0x", local_cid);
911                             stream_endpoint->l2cap_recovery_cid = 0;
912                             break;
913                         }
914 
915                         if (stream_endpoint->l2cap_reporting_cid == local_cid){
916                             log_info("L2CAP_EVENT_CHANNEL_CLOSED reporting cid 0x%0x", local_cid);
917                             stream_endpoint->l2cap_reporting_cid = 0;
918                             break;
919                         }
920                     }
921 
922                     if (connection){
923                         btstack_linked_list_iterator_t it;
924                         btstack_linked_list_iterator_init(&it, avdtp_get_stream_endpoints());
925                         while (btstack_linked_list_iterator_has_next(&it)){
926                             stream_endpoint = (avdtp_stream_endpoint_t *)btstack_linked_list_iterator_next(&it);
927                             if (stream_endpoint->connection == connection){
928                                 avdtp_reset_stream_endpoint(stream_endpoint);
929                             }
930                         }
931                         avdtp_signaling_emit_connection_released(context->avdtp_callback, connection->avdtp_cid);
932                         avdtp_finalize_connection(connection);
933                         break;
934                     }
935 
936                     break;
937 
938                 case HCI_EVENT_DISCONNECTION_COMPLETE:
939                     break;
940 
941                 case L2CAP_EVENT_CAN_SEND_NOW:
942                     log_debug("avdtp_packet_handler, L2CAP_EVENT_CAN_SEND_NOW l2cap_cid 0x%02x", channel);
943                     connection = avdtp_get_connection_for_l2cap_signaling_cid(channel);
944                     if (!connection) {
945                         stream_endpoint = avdtp_get_stream_endpoint_for_l2cap_cid(channel);
946                         if (!stream_endpoint->connection) break;
947                         connection = stream_endpoint->connection;
948                     }
949                     avdtp_handle_can_send_now(connection, channel, context);
950                     break;
951                 default:
952                     log_info("Unknown HCI event type %02x", hci_event_packet_get_type(packet));
953                     break;
954             }
955             break;
956 
957         default:
958             // other packet type
959             break;
960     }
961 }
962 
963 uint8_t avdtp_disconnect(uint16_t avdtp_cid){
964     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
965     if (!connection) return AVDTP_CONNECTION_DOES_NOT_EXIST;
966 
967     if (connection->state == AVDTP_SIGNALING_CONNECTION_W4_L2CAP_DISCONNECTED) return ERROR_CODE_SUCCESS;
968 
969     btstack_linked_list_iterator_t it;
970     btstack_linked_list_iterator_init(&it, avdtp_get_stream_endpoints());
971 
972     while (btstack_linked_list_iterator_has_next(&it)){
973         avdtp_stream_endpoint_t * stream_endpoint = (avdtp_stream_endpoint_t *)btstack_linked_list_iterator_next(&it);
974         if (stream_endpoint->connection != connection) continue;
975 
976         switch (stream_endpoint->state){
977             case AVDTP_STREAM_ENDPOINT_OPENED:
978             case AVDTP_STREAM_ENDPOINT_STREAMING:
979                 stream_endpoint->state = AVDTP_STREAM_ENDPOINT_W4_L2CAP_FOR_MEDIA_DISCONNECTED;
980                 l2cap_disconnect(stream_endpoint->l2cap_media_cid, 0);
981                 break;
982             default:
983                 break;
984         }
985     }
986 
987     connection->state = AVDTP_SIGNALING_CONNECTION_W4_L2CAP_DISCONNECTED;
988     l2cap_disconnect(connection->l2cap_signaling_cid, 0);
989     return ERROR_CODE_SUCCESS;
990 }
991 
992 uint8_t avdtp_open_stream(uint16_t avdtp_cid, uint8_t local_seid, uint8_t remote_seid){
993     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
994     if (!connection){
995         log_error("avdtp_media_connect: no connection for signaling cid 0x%02x found", avdtp_cid);
996         return AVDTP_CONNECTION_DOES_NOT_EXIST;
997     }
998 
999     if (connection->state != AVDTP_SIGNALING_CONNECTION_OPENED) {
1000         log_error("avdtp_media_connect: wrong connection state %d", connection->state);
1001         return AVDTP_CONNECTION_IN_WRONG_STATE;
1002     }
1003 
1004     avdtp_stream_endpoint_t * stream_endpoint = avdtp_get_stream_endpoint_with_seid(local_seid);
1005     if (!stream_endpoint) {
1006         log_error("avdtp_media_connect: no stream_endpoint with seid %d found", local_seid);
1007         return AVDTP_SEID_DOES_NOT_EXIST;
1008     }
1009 
1010     if (stream_endpoint->remote_sep.seid != remote_seid){
1011         log_error("avdtp_media_connect: no remote sep with seid %d registered with the stream endpoint", remote_seid);
1012         return AVDTP_SEID_DOES_NOT_EXIST;
1013     }
1014 
1015     if (stream_endpoint->state < AVDTP_STREAM_ENDPOINT_CONFIGURED) return AVDTP_STREAM_ENDPOINT_IN_WRONG_STATE;
1016 
1017     connection->initiator_transaction_label++;
1018     connection->initiator_remote_seid = remote_seid;
1019     connection->initiator_local_seid = local_seid;
1020     stream_endpoint->initiator_config_state = AVDTP_INITIATOR_W2_OPEN_STREAM;
1021     stream_endpoint->state = AVDTP_STREAM_ENDPOINT_W2_REQUEST_OPEN_STREAM;
1022     avdtp_request_can_send_now_initiator(connection, connection->l2cap_signaling_cid);
1023     return ERROR_CODE_SUCCESS;
1024 }
1025 
1026 uint8_t avdtp_start_stream(uint16_t avdtp_cid, uint8_t local_seid){
1027     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
1028     if (!connection){
1029         log_error("avdtp_start_stream: no connection for signaling cid 0x%02x found", avdtp_cid);
1030         return AVDTP_CONNECTION_DOES_NOT_EXIST;
1031     }
1032 
1033     avdtp_stream_endpoint_t * stream_endpoint = avdtp_get_stream_endpoint_with_seid(local_seid);
1034     if (!stream_endpoint) {
1035         log_error("avdtp_start_stream: no stream_endpoint with seid %d found", local_seid);
1036         return AVDTP_SEID_DOES_NOT_EXIST;
1037     }
1038 
1039     if (stream_endpoint->l2cap_media_cid == 0){
1040         log_error("avdtp_start_stream: no media connection for stream_endpoint with seid %d found", local_seid);
1041         return AVDTP_MEDIA_CONNECTION_DOES_NOT_EXIST;
1042     }
1043 
1044     if (!is_avdtp_remote_seid_registered(stream_endpoint)){
1045         log_error("avdtp_media_connect: no remote sep registered with the stream endpoint");
1046         return AVDTP_SEID_DOES_NOT_EXIST;
1047     }
1048 
1049     if (!is_avdtp_remote_seid_registered(stream_endpoint) || stream_endpoint->start_stream == 1){
1050         return ERROR_CODE_COMMAND_DISALLOWED;
1051     }
1052 
1053     stream_endpoint->start_stream = 1;
1054     connection->initiator_local_seid = local_seid;
1055     connection->initiator_remote_seid = stream_endpoint->remote_sep.seid;
1056     avdtp_request_can_send_now_initiator(connection, connection->l2cap_signaling_cid);
1057     return ERROR_CODE_SUCCESS;
1058 }
1059 
1060 uint8_t avdtp_stop_stream(uint16_t avdtp_cid, uint8_t local_seid){
1061     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
1062     if (!connection){
1063         log_error("avdtp_stop_stream: no connection for signaling cid 0x%02x found", avdtp_cid);
1064         return AVDTP_CONNECTION_DOES_NOT_EXIST;
1065     }
1066 
1067     avdtp_stream_endpoint_t * stream_endpoint = avdtp_get_stream_endpoint_with_seid(local_seid);
1068     if (!stream_endpoint) {
1069         log_error("avdtp_stop_stream: no stream_endpoint with seid %d found", local_seid);
1070         return AVDTP_SEID_DOES_NOT_EXIST;
1071     }
1072 
1073     if (stream_endpoint->l2cap_media_cid == 0){
1074         log_error("avdtp_stop_stream: no media connection for stream_endpoint with seid %d found", local_seid);
1075         return AVDTP_MEDIA_CONNECTION_DOES_NOT_EXIST;
1076     }
1077 
1078     if (!is_avdtp_remote_seid_registered(stream_endpoint) || stream_endpoint->stop_stream){
1079         return ERROR_CODE_COMMAND_DISALLOWED;
1080     }
1081 
1082     stream_endpoint->stop_stream = 1;
1083     connection->initiator_local_seid = local_seid;
1084     connection->initiator_remote_seid = stream_endpoint->remote_sep.seid;
1085     avdtp_request_can_send_now_initiator(connection, connection->l2cap_signaling_cid);
1086     return ERROR_CODE_SUCCESS;
1087 }
1088 
1089 uint8_t avdtp_abort_stream(uint16_t avdtp_cid, uint8_t local_seid){
1090     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
1091     if (!connection){
1092         log_error("avdtp_abort_stream: no connection for signaling cid 0x%02x found", avdtp_cid);
1093         return AVDTP_CONNECTION_DOES_NOT_EXIST;
1094     }
1095 
1096     avdtp_stream_endpoint_t * stream_endpoint = avdtp_get_stream_endpoint_with_seid(local_seid);
1097     if (!stream_endpoint) {
1098         log_error("avdtp_abort_stream: no stream_endpoint with seid %d found", local_seid);
1099         return AVDTP_SEID_DOES_NOT_EXIST;
1100     }
1101 
1102     if (stream_endpoint->l2cap_media_cid == 0){
1103         log_error("avdtp_abort_stream: no media connection for stream_endpoint with seid %d found", local_seid);
1104         return AVDTP_MEDIA_CONNECTION_DOES_NOT_EXIST;
1105     }
1106 
1107     if (!is_avdtp_remote_seid_registered(stream_endpoint) || stream_endpoint->abort_stream){
1108         return ERROR_CODE_COMMAND_DISALLOWED;
1109     }
1110 
1111     stream_endpoint->abort_stream = 1;
1112     connection->initiator_local_seid = local_seid;
1113     connection->initiator_remote_seid = stream_endpoint->remote_sep.seid;
1114     avdtp_request_can_send_now_initiator(connection, connection->l2cap_signaling_cid);
1115     return ERROR_CODE_SUCCESS;
1116 }
1117 
1118 uint8_t avdtp_suspend_stream(uint16_t avdtp_cid, uint8_t local_seid){
1119     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
1120     if (!connection){
1121         log_error("avdtp_suspend_stream: no connection for signaling cid 0x%02x found", avdtp_cid);
1122         return AVDTP_CONNECTION_DOES_NOT_EXIST;
1123     }
1124     avdtp_stream_endpoint_t * stream_endpoint = avdtp_get_stream_endpoint_with_seid(local_seid);
1125     if (!stream_endpoint) {
1126         log_error("avdtp_suspend_stream: no stream_endpoint with seid %d found", local_seid);
1127         return AVDTP_SEID_DOES_NOT_EXIST;
1128     }
1129 
1130     if (stream_endpoint->l2cap_media_cid == 0){
1131         log_error("avdtp_suspend_stream: no media connection for stream_endpoint with seid %d found", local_seid);
1132         return AVDTP_MEDIA_CONNECTION_DOES_NOT_EXIST;
1133     }
1134 
1135     if (!is_avdtp_remote_seid_registered(stream_endpoint) || stream_endpoint->suspend_stream){
1136         return ERROR_CODE_COMMAND_DISALLOWED;
1137     }
1138 
1139     stream_endpoint->suspend_stream = 1;
1140     connection->initiator_local_seid = local_seid;
1141     connection->initiator_remote_seid = stream_endpoint->remote_sep.seid;
1142     avdtp_request_can_send_now_initiator(connection, connection->l2cap_signaling_cid);
1143     return ERROR_CODE_SUCCESS;
1144 }
1145 
1146 uint8_t avdtp_discover_stream_endpoints(uint16_t avdtp_cid){
1147     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
1148     if (!connection){
1149         log_error("avdtp_discover_stream_endpoints: no connection for signaling cid 0x%02x found", avdtp_cid);
1150         return AVDTP_CONNECTION_DOES_NOT_EXIST;
1151     }
1152     if ((connection->state != AVDTP_SIGNALING_CONNECTION_OPENED) ||
1153         (connection->initiator_connection_state != AVDTP_SIGNALING_CONNECTION_INITIATOR_IDLE)) {
1154         return AVDTP_CONNECTION_IN_WRONG_STATE;
1155     }
1156 
1157     connection->initiator_transaction_label++;
1158     connection->initiator_connection_state = AVDTP_SIGNALING_CONNECTION_INITIATOR_W2_DISCOVER_SEPS;
1159     return avdtp_request_can_send_now_initiator(connection, connection->l2cap_signaling_cid);
1160 }
1161 
1162 
1163 uint8_t avdtp_get_capabilities(uint16_t avdtp_cid, uint8_t remote_seid){
1164     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
1165     if (!connection){
1166         log_error("No connection for AVDTP cid 0x%02x found", avdtp_cid);
1167         return AVDTP_CONNECTION_DOES_NOT_EXIST;
1168     }
1169     if ((connection->state != AVDTP_SIGNALING_CONNECTION_OPENED) ||
1170         (connection->initiator_connection_state != AVDTP_SIGNALING_CONNECTION_INITIATOR_IDLE)) {
1171         return AVDTP_CONNECTION_IN_WRONG_STATE;
1172     }
1173 
1174     connection->initiator_transaction_label++;
1175     connection->initiator_connection_state = AVDTP_SIGNALING_CONNECTION_INITIATOR_W2_GET_CAPABILITIES;
1176     connection->initiator_remote_seid = remote_seid;
1177     return avdtp_request_can_send_now_initiator(connection, connection->l2cap_signaling_cid);
1178 }
1179 
1180 
1181 uint8_t avdtp_get_all_capabilities(uint16_t avdtp_cid, uint8_t remote_seid){
1182     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
1183     if (!connection){
1184         log_error("No connection for AVDTP cid 0x%02x found", avdtp_cid);
1185         return AVDTP_CONNECTION_DOES_NOT_EXIST;
1186     }
1187     if ((connection->state != AVDTP_SIGNALING_CONNECTION_OPENED) ||
1188         (connection->initiator_connection_state != AVDTP_SIGNALING_CONNECTION_INITIATOR_IDLE)) {
1189         return AVDTP_CONNECTION_IN_WRONG_STATE;
1190     }
1191 
1192     connection->initiator_transaction_label++;
1193     connection->initiator_connection_state = AVDTP_SIGNALING_CONNECTION_INITIATOR_W2_GET_ALL_CAPABILITIES;
1194     connection->initiator_remote_seid = remote_seid;
1195     return avdtp_request_can_send_now_initiator(connection, connection->l2cap_signaling_cid);
1196 }
1197 
1198 uint8_t avdtp_get_configuration(uint16_t avdtp_cid, uint8_t remote_seid){
1199     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
1200     if (!connection){
1201         log_error("No connection for AVDTP cid 0x%02x found", avdtp_cid);
1202         return AVDTP_CONNECTION_DOES_NOT_EXIST;
1203     }
1204     if ((connection->state != AVDTP_SIGNALING_CONNECTION_OPENED) ||
1205         (connection->initiator_connection_state != AVDTP_SIGNALING_CONNECTION_INITIATOR_IDLE)) {
1206         return AVDTP_CONNECTION_IN_WRONG_STATE;
1207     }
1208 
1209     connection->initiator_transaction_label++;
1210     connection->initiator_connection_state = AVDTP_SIGNALING_CONNECTION_INITIATOR_W2_GET_CONFIGURATION;
1211     connection->initiator_remote_seid = remote_seid;
1212     return avdtp_request_can_send_now_initiator(connection, connection->l2cap_signaling_cid);
1213 }
1214 
1215 uint8_t avdtp_set_configuration(uint16_t avdtp_cid, uint8_t local_seid, uint8_t remote_seid, uint16_t configured_services_bitmap, avdtp_capabilities_t configuration){
1216     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
1217     if (!connection){
1218         log_error("No connection for AVDTP cid 0x%02x found", avdtp_cid);
1219         return AVDTP_CONNECTION_DOES_NOT_EXIST;
1220     }
1221     if ((connection->state != AVDTP_SIGNALING_CONNECTION_OPENED) ||
1222         (connection->initiator_connection_state != AVDTP_SIGNALING_CONNECTION_INITIATOR_IDLE)) {
1223         log_error("connection in wrong state, %d, initiator state %d", connection->state, connection->initiator_connection_state);
1224         return AVDTP_CONNECTION_IN_WRONG_STATE;
1225     }
1226     if (connection->configuration_state != AVDTP_CONFIGURATION_STATE_IDLE){
1227         log_info("configuration already started, config state %u", connection->configuration_state);
1228         return AVDTP_CONNECTION_IN_WRONG_STATE;
1229     }
1230 
1231     avdtp_stream_endpoint_t * stream_endpoint = avdtp_get_stream_endpoint_for_seid(local_seid);
1232     if (!stream_endpoint) {
1233         log_error("No initiator stream endpoint for seid %d", local_seid);
1234         return AVDTP_STREAM_ENDPOINT_DOES_NOT_EXIST;
1235     }
1236     if (stream_endpoint->state >= AVDTP_STREAM_ENDPOINT_CONFIGURED){
1237         log_error("Stream endpoint seid %d in wrong state %d", local_seid, stream_endpoint->state);
1238         return AVDTP_STREAM_ENDPOINT_IN_WRONG_STATE;
1239     }
1240 
1241     connection->active_stream_endpoint = (void*) stream_endpoint;
1242     connection->configuration_state = AVDTP_CONFIGURATION_STATE_LOCAL_INITIATED;
1243 
1244     connection->initiator_transaction_label++;
1245     connection->initiator_remote_seid = remote_seid;
1246     connection->initiator_local_seid = local_seid;
1247     stream_endpoint->remote_configuration_bitmap = configured_services_bitmap;
1248     stream_endpoint->remote_configuration = configuration;
1249     stream_endpoint->initiator_config_state = AVDTP_INITIATOR_W2_SET_CONFIGURATION;
1250 
1251     // cache media codec information for SBC
1252     stream_endpoint->media_codec_type = configuration.media_codec.media_codec_type;
1253     if (configuration.media_codec.media_codec_type == AVDTP_CODEC_SBC){
1254         stream_endpoint->media_type = configuration.media_codec.media_type;
1255         (void)memcpy(stream_endpoint->media_codec_sbc_info,
1256                      configuration.media_codec.media_codec_information, 4);
1257     }
1258     return avdtp_request_can_send_now_initiator(connection, connection->l2cap_signaling_cid);
1259 }
1260 
1261 uint8_t avdtp_reconfigure(uint16_t avdtp_cid, uint8_t local_seid, uint8_t remote_seid, uint16_t configured_services_bitmap, avdtp_capabilities_t configuration){
1262     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
1263     if (!connection){
1264         log_error("No connection for AVDTP cid 0x%02x found", avdtp_cid);
1265         return AVDTP_CONNECTION_DOES_NOT_EXIST;
1266     }
1267     //TODO: if opened only app capabilities, enable reconfigure for not opened
1268     if ((connection->state != AVDTP_SIGNALING_CONNECTION_OPENED) ||
1269         (connection->initiator_connection_state != AVDTP_SIGNALING_CONNECTION_INITIATOR_IDLE)) {
1270         return AVDTP_CONNECTION_IN_WRONG_STATE;
1271     }
1272 
1273     avdtp_stream_endpoint_t * stream_endpoint = avdtp_get_stream_endpoint_for_seid(local_seid);
1274     if (!stream_endpoint) {
1275         log_error("avdtp_reconfigure: no initiator stream endpoint for seid %d", local_seid);
1276         return AVDTP_STREAM_ENDPOINT_DOES_NOT_EXIST;
1277     }
1278 
1279     if (!is_avdtp_remote_seid_registered(stream_endpoint)){
1280         log_error("avdtp_reconfigure: no associated remote sep");
1281         return AVDTP_STREAM_ENDPOINT_IN_WRONG_STATE;
1282     }
1283 
1284     connection->initiator_transaction_label++;
1285     connection->initiator_remote_seid = remote_seid;
1286     connection->initiator_local_seid = local_seid;
1287     stream_endpoint->remote_configuration_bitmap = configured_services_bitmap;
1288     stream_endpoint->remote_configuration = configuration;
1289     stream_endpoint->initiator_config_state = AVDTP_INITIATOR_W2_RECONFIGURE_STREAM_WITH_SEID;
1290     return avdtp_request_can_send_now_initiator(connection, connection->l2cap_signaling_cid);
1291 }
1292 
1293 void    avdtp_set_preferred_sampling_frequeny(avdtp_stream_endpoint_t * stream_endpoint, uint32_t sampling_frequency){
1294     stream_endpoint->preferred_sampling_frequency = sampling_frequency;
1295 }
1296 
1297 uint8_t avdtp_choose_sbc_channel_mode(avdtp_stream_endpoint_t * stream_endpoint, uint8_t remote_channel_mode_bitmap){
1298     uint8_t * media_codec = stream_endpoint->sep.capabilities.media_codec.media_codec_information;
1299     uint8_t channel_mode_bitmap = (media_codec[0] & 0x0F) & remote_channel_mode_bitmap;
1300 
1301     uint8_t channel_mode = AVDTP_SBC_STEREO;
1302     if (channel_mode_bitmap & AVDTP_SBC_JOINT_STEREO){
1303         channel_mode = AVDTP_SBC_JOINT_STEREO;
1304     } else if (channel_mode_bitmap & AVDTP_SBC_STEREO){
1305         channel_mode = AVDTP_SBC_STEREO;
1306     } else if (channel_mode_bitmap & AVDTP_SBC_DUAL_CHANNEL){
1307         channel_mode = AVDTP_SBC_DUAL_CHANNEL;
1308     } else if (channel_mode_bitmap & AVDTP_SBC_MONO){
1309         channel_mode = AVDTP_SBC_MONO;
1310     }
1311     return channel_mode;
1312 }
1313 
1314 uint8_t avdtp_choose_sbc_allocation_method(avdtp_stream_endpoint_t * stream_endpoint, uint8_t remote_allocation_method_bitmap){
1315     uint8_t * media_codec = stream_endpoint->sep.capabilities.media_codec.media_codec_information;
1316     uint8_t allocation_method_bitmap = (media_codec[1] & 0x03) & remote_allocation_method_bitmap;
1317 
1318     uint8_t allocation_method = AVDTP_SBC_ALLOCATION_METHOD_LOUDNESS;
1319     if (allocation_method_bitmap & AVDTP_SBC_ALLOCATION_METHOD_LOUDNESS){
1320         allocation_method = AVDTP_SBC_ALLOCATION_METHOD_LOUDNESS;
1321     } else if (allocation_method_bitmap & AVDTP_SBC_ALLOCATION_METHOD_SNR){
1322         allocation_method = AVDTP_SBC_ALLOCATION_METHOD_SNR;
1323     }
1324     return allocation_method;
1325 }
1326 
1327 uint8_t avdtp_stream_endpoint_seid(avdtp_stream_endpoint_t * stream_endpoint){
1328     if (!stream_endpoint) return 0;
1329     return stream_endpoint->sep.seid;
1330 }
1331 uint8_t avdtp_choose_sbc_subbands(avdtp_stream_endpoint_t * stream_endpoint, uint8_t remote_subbands_bitmap){
1332     if (!stream_endpoint) return 0;
1333     uint8_t * media_codec = stream_endpoint->sep.capabilities.media_codec.media_codec_information;
1334     uint8_t subbands_bitmap = ((media_codec[1] >> 2) & 0x03) & remote_subbands_bitmap;
1335 
1336     uint8_t subbands = AVDTP_SBC_SUBBANDS_8;
1337     if (subbands_bitmap & AVDTP_SBC_SUBBANDS_8){
1338         subbands = AVDTP_SBC_SUBBANDS_8;
1339     } else if (subbands_bitmap & AVDTP_SBC_SUBBANDS_4){
1340         subbands = AVDTP_SBC_SUBBANDS_4;
1341     }
1342     return subbands;
1343 }
1344 
1345 uint8_t avdtp_choose_sbc_block_length(avdtp_stream_endpoint_t * stream_endpoint, uint8_t remote_block_length_bitmap){
1346     if (!stream_endpoint) return 0;
1347     uint8_t * media_codec = stream_endpoint->sep.capabilities.media_codec.media_codec_information;
1348     uint8_t block_length_bitmap = (media_codec[1] >> 4) & remote_block_length_bitmap;
1349 
1350     uint8_t block_length = AVDTP_SBC_BLOCK_LENGTH_16;
1351     if (block_length_bitmap & AVDTP_SBC_BLOCK_LENGTH_16){
1352         block_length = AVDTP_SBC_BLOCK_LENGTH_16;
1353     } else if (block_length_bitmap & AVDTP_SBC_BLOCK_LENGTH_12){
1354         block_length = AVDTP_SBC_BLOCK_LENGTH_12;
1355     } else if (block_length_bitmap & AVDTP_SBC_BLOCK_LENGTH_8){
1356         block_length = AVDTP_SBC_BLOCK_LENGTH_8;
1357     } else if (block_length_bitmap & AVDTP_SBC_BLOCK_LENGTH_4){
1358         block_length = AVDTP_SBC_BLOCK_LENGTH_4;
1359     }
1360     return block_length;
1361 }
1362 
1363 uint8_t avdtp_choose_sbc_sampling_frequency(avdtp_stream_endpoint_t * stream_endpoint, uint8_t remote_sampling_frequency_bitmap){
1364     if (!stream_endpoint) return 0;
1365     uint8_t * media_codec = stream_endpoint->sep.capabilities.media_codec.media_codec_information;
1366     uint8_t supported_sampling_frequency_bitmap = (media_codec[0] >> 4) & remote_sampling_frequency_bitmap;
1367 
1368     // use preferred sampling frequency if possible
1369     if ((stream_endpoint->preferred_sampling_frequency == 48000) && (supported_sampling_frequency_bitmap & AVDTP_SBC_48000)){
1370         return AVDTP_SBC_48000;
1371     }
1372     if ((stream_endpoint->preferred_sampling_frequency == 44100) && (supported_sampling_frequency_bitmap & AVDTP_SBC_44100)){
1373         return AVDTP_SBC_44100;
1374     }
1375     if ((stream_endpoint->preferred_sampling_frequency == 32000) && (supported_sampling_frequency_bitmap & AVDTP_SBC_32000)){
1376         return AVDTP_SBC_32000;
1377     }
1378     if ((stream_endpoint->preferred_sampling_frequency == 16000) && (supported_sampling_frequency_bitmap & AVDTP_SBC_16000)){
1379         return AVDTP_SBC_16000;
1380     }
1381 
1382     // otherwise, use highest available
1383     if (supported_sampling_frequency_bitmap & AVDTP_SBC_48000){
1384         return AVDTP_SBC_48000;
1385     }
1386     if (supported_sampling_frequency_bitmap & AVDTP_SBC_44100){
1387         return AVDTP_SBC_44100;
1388     }
1389     if (supported_sampling_frequency_bitmap & AVDTP_SBC_32000){
1390         return AVDTP_SBC_32000;
1391     }
1392     if (supported_sampling_frequency_bitmap & AVDTP_SBC_16000){
1393         return AVDTP_SBC_16000;
1394     }
1395     return AVDTP_SBC_44100; // some default
1396 }
1397 
1398 uint8_t avdtp_choose_sbc_max_bitpool_value(avdtp_stream_endpoint_t * stream_endpoint, uint8_t remote_max_bitpool_value){
1399     if (!stream_endpoint) return 0;
1400     uint8_t * media_codec = stream_endpoint->sep.capabilities.media_codec.media_codec_information;
1401     return btstack_min(media_codec[3], remote_max_bitpool_value);
1402 }
1403 
1404 uint8_t avdtp_choose_sbc_min_bitpool_value(avdtp_stream_endpoint_t * stream_endpoint, uint8_t remote_min_bitpool_value){
1405     if (!stream_endpoint) return 0;
1406     uint8_t * media_codec = stream_endpoint->sep.capabilities.media_codec.media_codec_information;
1407     return btstack_max(media_codec[2], remote_min_bitpool_value);
1408 }
1409 
1410 uint8_t is_avdtp_remote_seid_registered(avdtp_stream_endpoint_t * stream_endpoint){
1411     if (!stream_endpoint) return 0;
1412     if (stream_endpoint->remote_sep.seid == 0) return 0;
1413     if (stream_endpoint->remote_sep.seid > 0x3E) return 0;
1414     return 1;
1415 }
1416