xref: /btstack/src/classic/avdtp.c (revision 2d9d000f0d11d477d59a9de47a953eafddb31c49)
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 
135 void avdtp_signaling_emit_delay(uint16_t avdtp_cid, uint8_t local_seid, uint16_t delay) {
136     uint8_t event[8];
137     int pos = 0;
138     event[pos++] = HCI_EVENT_AVDTP_META;
139     event[pos++] = sizeof(event) - 2;
140     event[pos++] = AVDTP_SUBEVENT_SIGNALING_DELAY_REPORT;
141     little_endian_store_16(event, pos, avdtp_cid);
142     pos += 2;
143     event[pos++] = local_seid;
144     little_endian_store_16(event, pos, delay);
145     pos += 2;
146     (*avdtp_source_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
147 }
148 
149 btstack_linked_list_t * avdtp_get_stream_endpoints(void){
150     return &stream_endpoints;
151 }
152 
153 static avdtp_connection_t * avdtp_get_connection_for_bd_addr(bd_addr_t addr){
154     btstack_linked_list_iterator_t it;
155     btstack_linked_list_iterator_init(&it, &connections);
156     while (btstack_linked_list_iterator_has_next(&it)){
157         avdtp_connection_t * connection = (avdtp_connection_t *)btstack_linked_list_iterator_next(&it);
158         if (memcmp(addr, connection->remote_addr, 6) != 0) continue;
159         return connection;
160     }
161     return NULL;
162 }
163 
164  avdtp_connection_t * avdtp_get_connection_for_avdtp_cid(uint16_t avdtp_cid){
165     btstack_linked_list_iterator_t it;
166     btstack_linked_list_iterator_init(&it, &connections);
167     while (btstack_linked_list_iterator_has_next(&it)){
168         avdtp_connection_t * connection = (avdtp_connection_t *)btstack_linked_list_iterator_next(&it);
169         if (connection->avdtp_cid != avdtp_cid) continue;
170         return connection;
171     }
172     return NULL;
173 }
174 
175 
176 avdtp_stream_endpoint_t * avdtp_get_stream_endpoint_for_seid(uint16_t seid){
177     btstack_linked_list_iterator_t it;
178     btstack_linked_list_iterator_init(&it, avdtp_get_stream_endpoints());
179     while (btstack_linked_list_iterator_has_next(&it)){
180         avdtp_stream_endpoint_t * stream_endpoint = (avdtp_stream_endpoint_t *)btstack_linked_list_iterator_next(&it);
181         if (stream_endpoint->sep.seid == seid){
182             return stream_endpoint;
183         }
184     }
185     return NULL;
186 }
187 
188 avdtp_connection_t * avdtp_get_connection_for_l2cap_signaling_cid(uint16_t l2cap_cid){
189     btstack_linked_list_iterator_t it;
190     btstack_linked_list_iterator_init(&it, &connections);
191     while (btstack_linked_list_iterator_has_next(&it)){
192         avdtp_connection_t * connection = (avdtp_connection_t *)btstack_linked_list_iterator_next(&it);
193         if (connection->l2cap_signaling_cid != l2cap_cid) continue;
194         return connection;
195     }
196     return NULL;
197 }
198 
199 static avdtp_stream_endpoint_t * avdtp_get_stream_endpoint_for_l2cap_cid(uint16_t l2cap_cid){
200     btstack_linked_list_iterator_t it;
201     btstack_linked_list_iterator_init(&it, avdtp_get_stream_endpoints());
202     while (btstack_linked_list_iterator_has_next(&it)){
203         avdtp_stream_endpoint_t * stream_endpoint = (avdtp_stream_endpoint_t *)btstack_linked_list_iterator_next(&it);
204         if (stream_endpoint->l2cap_media_cid == l2cap_cid){
205             return stream_endpoint;
206         }
207         if (stream_endpoint->l2cap_reporting_cid == l2cap_cid){
208             return stream_endpoint;
209         }
210         if (stream_endpoint->l2cap_recovery_cid == l2cap_cid){
211             return stream_endpoint;
212         }
213     }
214     return NULL;
215 }
216 
217 static avdtp_stream_endpoint_t * avdtp_get_stream_endpoint_for_signaling_cid(uint16_t l2cap_cid){
218     btstack_linked_list_iterator_t it;
219     btstack_linked_list_iterator_init(&it, avdtp_get_stream_endpoints());
220     while (btstack_linked_list_iterator_has_next(&it)){
221         avdtp_stream_endpoint_t * stream_endpoint = (avdtp_stream_endpoint_t *)btstack_linked_list_iterator_next(&it);
222         if (stream_endpoint->connection){
223             if (stream_endpoint->connection->l2cap_signaling_cid == l2cap_cid){
224                 return stream_endpoint;
225             }
226         }
227     }
228     return NULL;
229 }
230 
231 avdtp_stream_endpoint_t * avdtp_get_stream_endpoint_with_seid(uint8_t seid){
232     btstack_linked_list_iterator_t it;
233     btstack_linked_list_iterator_init(&it, avdtp_get_stream_endpoints());
234     while (btstack_linked_list_iterator_has_next(&it)){
235         avdtp_stream_endpoint_t * stream_endpoint = (avdtp_stream_endpoint_t *)btstack_linked_list_iterator_next(&it);
236         if (stream_endpoint->sep.seid == seid){
237             return stream_endpoint;
238         }
239     }
240     return NULL;
241 }
242 
243 avdtp_stream_endpoint_t * avdtp_get_stream_endpoint_associated_with_acp_seid(uint16_t acp_seid){
244     btstack_linked_list_iterator_t it;
245     btstack_linked_list_iterator_init(&it, avdtp_get_stream_endpoints());
246     while (btstack_linked_list_iterator_has_next(&it)){
247         avdtp_stream_endpoint_t * stream_endpoint = (avdtp_stream_endpoint_t *)btstack_linked_list_iterator_next(&it);
248         if (stream_endpoint->remote_sep.seid == acp_seid){
249             return stream_endpoint;
250         }
251     }
252     return NULL;
253 }
254 
255 static uint16_t avdtp_get_next_initiator_transaction_label(void){
256     initiator_transaction_id_counter++;
257     if (initiator_transaction_id_counter == 0){
258         initiator_transaction_id_counter = 1;
259     }
260     return initiator_transaction_id_counter;
261 }
262 
263 static avdtp_connection_t * avdtp_create_connection(bd_addr_t remote_addr, uint16_t cid){
264     avdtp_connection_t * connection = btstack_memory_avdtp_connection_get();
265     if (!connection){
266         log_error("Not enough memory to create connection");
267         return NULL;
268     }
269     connection->state = AVDTP_SIGNALING_CONNECTION_IDLE;
270     connection->initiator_transaction_label = avdtp_get_next_initiator_transaction_label();
271     connection->configuration_state = AVDTP_CONFIGURATION_STATE_IDLE;
272     connection->avdtp_cid = cid;
273     (void)memcpy(connection->remote_addr, remote_addr, 6);
274 
275     btstack_linked_list_add(&connections, (btstack_linked_item_t *) connection);
276     return connection;
277 }
278 
279 static uint16_t avdtp_get_next_cid(void){
280     if (avdtp_cid_counter == 0xffff) {
281         avdtp_cid_counter = 1;
282     } else {
283         avdtp_cid_counter++;
284     }
285     return avdtp_cid_counter;
286 }
287 
288 static uint16_t avdtp_get_next_local_seid(void){
289     if (stream_endpoints_id_counter == 0xffff) {
290         stream_endpoints_id_counter = 1;
291     } else {
292         stream_endpoints_id_counter++;
293     }
294     return stream_endpoints_id_counter;
295 }
296 
297 static uint8_t avdtp_start_sdp_query(btstack_packet_handler_t packet_handler, avdtp_connection_t * connection) {
298     connection->avdtp_l2cap_psm = 0;
299     connection->avdtp_version  = 0;
300     connection->sink_supported = false;
301     connection->source_supported = false;
302     sdp_query_context_avdtp_cid = connection->avdtp_cid;
303 
304     return sdp_client_query_uuid16(packet_handler, (uint8_t *) connection->remote_addr, BLUETOOTH_PROTOCOL_AVDTP);
305 }
306 
307 uint8_t avdtp_connect(bd_addr_t remote, avdtp_role_t role, uint16_t * avdtp_cid){
308     // TODO: implement delayed SDP query
309     if (sdp_client_ready() == 0){
310         return ERROR_CODE_COMMAND_DISALLOWED;
311     }
312 
313     avdtp_connection_t * connection = avdtp_get_connection_for_bd_addr(remote);
314     if (connection){
315         return ERROR_CODE_COMMAND_DISALLOWED;
316     }
317 
318     uint16_t cid = avdtp_get_next_cid();
319     if (avdtp_cid != NULL) {
320         *avdtp_cid = cid;
321     }
322 
323     connection = avdtp_create_connection(remote, cid);
324     if (!connection) return BTSTACK_MEMORY_ALLOC_FAILED;
325 
326     connection->avdtp_cid = cid;
327 
328     switch (role){
329         case AVDTP_ROLE_SOURCE:
330             connection->state = AVDTP_SIGNALING_W4_SDP_QUERY_FOR_REMOTE_SINK_COMPLETE;
331             break;
332         case AVDTP_ROLE_SINK:
333             connection->state = AVDTP_SIGNALING_W4_SDP_QUERY_FOR_REMOTE_SOURCE_COMPLETE;
334             break;
335         default:
336             return ERROR_CODE_COMMAND_DISALLOWED;
337     }
338     return avdtp_start_sdp_query(&avdtp_handle_sdp_client_query_result, connection);
339 }
340 
341 
342 void avdtp_register_sink_packet_handler(btstack_packet_handler_t callback){
343     btstack_assert(callback != NULL);
344     avdtp_sink_callback = callback;
345 }
346 
347 void avdtp_register_source_packet_handler(btstack_packet_handler_t callback){
348     btstack_assert(callback != NULL);
349     avdtp_source_callback = callback;
350 }
351 
352 void avdtp_register_media_transport_category(avdtp_stream_endpoint_t * stream_endpoint){
353     if (!stream_endpoint){
354         log_error("Stream endpoint with given seid is not registered.");
355         return;
356     }
357     uint16_t bitmap = store_bit16(stream_endpoint->sep.registered_service_categories, AVDTP_MEDIA_TRANSPORT, 1);
358     stream_endpoint->sep.registered_service_categories = bitmap;
359 }
360 
361 void avdtp_register_reporting_category(avdtp_stream_endpoint_t * stream_endpoint){
362     if (!stream_endpoint){
363         log_error("Stream endpoint with given seid is not registered.");
364         return;
365     }
366     uint16_t bitmap = store_bit16(stream_endpoint->sep.registered_service_categories, AVDTP_REPORTING, 1);
367     stream_endpoint->sep.registered_service_categories = bitmap;
368 }
369 
370 void avdtp_register_delay_reporting_category(avdtp_stream_endpoint_t * stream_endpoint){
371     if (!stream_endpoint){
372         log_error("Stream endpoint with given seid is not registered.");
373         return;
374     }
375     uint16_t bitmap = store_bit16(stream_endpoint->sep.registered_service_categories, AVDTP_DELAY_REPORTING, 1);
376     stream_endpoint->sep.registered_service_categories = bitmap;
377 }
378 
379 void avdtp_register_recovery_category(avdtp_stream_endpoint_t * stream_endpoint, uint8_t maximum_recovery_window_size, uint8_t maximum_number_media_packets){
380     if (!stream_endpoint){
381         log_error("Stream endpoint with given seid is not registered.");
382         return;
383     }
384     uint16_t bitmap = store_bit16(stream_endpoint->sep.registered_service_categories, AVDTP_RECOVERY, 1);
385     stream_endpoint->sep.registered_service_categories = bitmap;
386     stream_endpoint->sep.capabilities.recovery.recovery_type = 0x01; // 0x01 = RFC2733
387     stream_endpoint->sep.capabilities.recovery.maximum_recovery_window_size = maximum_recovery_window_size;
388     stream_endpoint->sep.capabilities.recovery.maximum_number_media_packets = maximum_number_media_packets;
389 }
390 
391 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){
392     if (!stream_endpoint){
393         log_error("Stream endpoint with given seid is not registered.");
394         return;
395     }
396     uint16_t bitmap = store_bit16(stream_endpoint->sep.registered_service_categories, AVDTP_CONTENT_PROTECTION, 1);
397     stream_endpoint->sep.registered_service_categories = bitmap;
398     stream_endpoint->sep.capabilities.content_protection.cp_type = cp_type;
399     (void)memcpy(stream_endpoint->sep.capabilities.content_protection.cp_type_value,
400                  cp_type_value,
401                  btstack_min(cp_type_value_len, AVDTP_MAX_CONTENT_PROTECTION_TYPE_VALUE_LEN));
402     stream_endpoint->sep.capabilities.content_protection.cp_type_value_len = btstack_min(cp_type_value_len, AVDTP_MAX_CONTENT_PROTECTION_TYPE_VALUE_LEN);
403 }
404 
405 void avdtp_register_header_compression_category(avdtp_stream_endpoint_t * stream_endpoint, uint8_t back_ch, uint8_t media, uint8_t recovery){
406     if (!stream_endpoint){
407         log_error("Stream endpoint with given seid is not registered.");
408         return;
409     }
410     uint16_t bitmap = store_bit16(stream_endpoint->sep.registered_service_categories, AVDTP_HEADER_COMPRESSION, 1);
411     stream_endpoint->sep.registered_service_categories = bitmap;
412     stream_endpoint->sep.capabilities.header_compression.back_ch = back_ch;
413     stream_endpoint->sep.capabilities.header_compression.media = media;
414     stream_endpoint->sep.capabilities.header_compression.recovery = recovery;
415 }
416 
417 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){
418     if (!stream_endpoint){
419         log_error("Stream endpoint with given seid is not registered.");
420         return;
421     }
422     uint16_t bitmap = store_bit16(stream_endpoint->sep.registered_service_categories, AVDTP_MEDIA_CODEC, 1);
423     stream_endpoint->sep.registered_service_categories = bitmap;
424     stream_endpoint->sep.capabilities.media_codec.media_type = media_type;
425     stream_endpoint->sep.capabilities.media_codec.media_codec_type = media_codec_type;
426     stream_endpoint->sep.capabilities.media_codec.media_codec_information = media_codec_info;
427     stream_endpoint->sep.capabilities.media_codec.media_codec_information_len = media_codec_info_len;
428 }
429 
430 void avdtp_register_multiplexing_category(avdtp_stream_endpoint_t * stream_endpoint, uint8_t fragmentation){
431     if (!stream_endpoint){
432         log_error("Stream endpoint with given seid is not registered.");
433         return;
434     }
435     uint16_t bitmap = store_bit16(stream_endpoint->sep.registered_service_categories, AVDTP_MULTIPLEXING, 1);
436     stream_endpoint->sep.registered_service_categories = bitmap;
437     stream_endpoint->sep.capabilities.multiplexing_mode.fragmentation = fragmentation;
438 }
439 
440 void avdtp_register_media_handler(void (*callback)(uint8_t local_seid, uint8_t *packet, uint16_t size)){
441     avdtp_sink_handle_media_data = callback;
442 }
443 
444 /* START: tracking can send now requests pro l2cap cid */
445 void avdtp_handle_can_send_now(avdtp_connection_t * connection, uint16_t l2cap_cid, avdtp_context_t * context){
446     if (connection->wait_to_send_acceptor){
447         log_debug("call avdtp_acceptor_stream_config_subsm_run");
448         connection->wait_to_send_acceptor = 0;
449         avdtp_acceptor_stream_config_subsm_run(connection, context);
450     } else if (connection->wait_to_send_initiator){
451         log_debug("call avdtp_initiator_stream_config_subsm_run");
452         connection->wait_to_send_initiator = 0;
453         avdtp_initiator_stream_config_subsm_run(connection, context);
454     }
455 
456     // re-register
457     bool more_to_send = connection->wait_to_send_acceptor || connection->wait_to_send_initiator;
458     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);
459 
460     if (more_to_send){
461         l2cap_request_can_send_now_event(l2cap_cid);
462     }
463 }
464 /* END: tracking can send now requests pro l2cap cid */
465 
466 
467 avdtp_stream_endpoint_t * avdtp_create_stream_endpoint(avdtp_sep_type_t sep_type, avdtp_media_type_t media_type){
468     avdtp_stream_endpoint_t * stream_endpoint = btstack_memory_avdtp_stream_endpoint_get();
469     if (!stream_endpoint){
470         log_error("Not enough memory to create stream endpoint");
471         return NULL;
472     }
473     stream_endpoint->sep.seid = avdtp_get_next_local_seid();
474     stream_endpoint->sep.media_type = media_type;
475     stream_endpoint->sep.type = sep_type;
476     btstack_linked_list_add(avdtp_get_stream_endpoints(), (btstack_linked_item_t *) stream_endpoint);
477     return stream_endpoint;
478 }
479 
480 static void handle_l2cap_data_packet_for_signaling_connection(avdtp_connection_t * connection, uint8_t *packet, uint16_t size, avdtp_context_t * context){
481     if (size < 2) return;
482 
483     uint16_t offset;
484     avdtp_message_type_t message_type = avdtp_get_signaling_packet_type(packet);
485     switch (message_type){
486         case AVDTP_CMD_MSG:
487             offset = avdtp_read_signaling_header(&connection->acceptor_signaling_packet, packet, size);
488             avdtp_acceptor_stream_config_subsm(connection, packet, size, offset, context);
489             break;
490         default:
491             offset = avdtp_read_signaling_header(&connection->initiator_signaling_packet, packet, size);
492             avdtp_initiator_stream_config_subsm(connection, packet, size, offset, context);
493             break;
494     }
495 }
496 
497 static void avdtp_handle_sdp_client_query_attribute_value(avdtp_connection_t * connection, uint8_t *packet){
498     des_iterator_t des_list_it;
499     des_iterator_t prot_it;
500 
501     // Handle new SDP record
502     if (sdp_event_query_attribute_byte_get_record_id(packet) != record_id) {
503         record_id = sdp_event_query_attribute_byte_get_record_id(packet);
504         // log_info("SDP Record: Nr: %d", record_id);
505     }
506 
507     if (sdp_event_query_attribute_byte_get_attribute_length(packet) <= attribute_value_buffer_size) {
508         attribute_value[sdp_event_query_attribute_byte_get_data_offset(packet)] = sdp_event_query_attribute_byte_get_data(packet);
509 
510         if ((uint16_t)(sdp_event_query_attribute_byte_get_data_offset(packet)+1) == sdp_event_query_attribute_byte_get_attribute_length(packet)) {
511 
512             switch(sdp_event_query_attribute_byte_get_attribute_id(packet)) {
513 
514                 case BLUETOOTH_ATTRIBUTE_SERVICE_CLASS_ID_LIST:
515                     if (de_get_element_type(attribute_value) != DE_DES) break;
516                     for (des_iterator_init(&des_list_it, attribute_value); des_iterator_has_more(&des_list_it); des_iterator_next(&des_list_it)) {
517                         uint8_t * element = des_iterator_get_element(&des_list_it);
518                         if (de_get_element_type(element) != DE_UUID) continue;
519                         uint32_t uuid = de_get_uuid32(element);
520                         switch (uuid){
521                             case BLUETOOTH_SERVICE_CLASS_AUDIO_SOURCE:
522                                 connection->source_supported = true;
523                                 log_info("source_supported");
524                                 break;
525                             case BLUETOOTH_SERVICE_CLASS_AUDIO_SINK:
526                                 connection->sink_supported = true;
527                                 log_info("sink_supported");
528                                 break;
529                             default:
530                                 break;
531                         }
532                     }
533                     break;
534 
535                 case BLUETOOTH_ATTRIBUTE_PROTOCOL_DESCRIPTOR_LIST:
536                     // log_info("SDP Attribute: 0x%04x", sdp_event_query_attribute_byte_get_attribute_id(packet));
537                     for (des_iterator_init(&des_list_it, attribute_value); des_iterator_has_more(&des_list_it); des_iterator_next(&des_list_it)) {
538                         uint8_t       *des_element;
539                         uint8_t       *element;
540                         uint32_t       uuid;
541 
542                         if (des_iterator_get_type(&des_list_it) != DE_DES) continue;
543 
544                         des_element = des_iterator_get_element(&des_list_it);
545                         des_iterator_init(&prot_it, des_element);
546                         element = des_iterator_get_element(&prot_it);
547 
548                         if (de_get_element_type(element) != DE_UUID) continue;
549 
550                         uuid = de_get_uuid32(element);
551                         des_iterator_next(&prot_it);
552                         // we assume that the even if there are both roles supported, remote device uses the same psm and avdtp version for both
553                         switch (uuid){
554                             case BLUETOOTH_PROTOCOL_L2CAP:
555                                 if (!des_iterator_has_more(&prot_it)) continue;
556                                 de_element_get_uint16(des_iterator_get_element(&prot_it), &connection->avdtp_l2cap_psm);
557                                 break;
558                             case BLUETOOTH_PROTOCOL_AVDTP:
559                                 if (!des_iterator_has_more(&prot_it)) continue;
560                                 de_element_get_uint16(des_iterator_get_element(&prot_it), &connection->avdtp_version);
561                                 break;
562                             default:
563                                 break;
564                         }
565                     }
566                     break;
567 
568                 default:
569                     break;
570             }
571         }
572     } else {
573         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));
574     }
575 
576 }
577 
578 static void avdtp_finalize_connection(avdtp_connection_t * connection){
579     btstack_run_loop_remove_timer(&connection->retry_timer);
580     btstack_linked_list_remove(&connections, (btstack_linked_item_t*) connection);
581     btstack_memory_avdtp_connection_free(connection);
582 }
583 
584 static void avdtp_handle_sdp_query_failed(avdtp_connection_t * connection, uint8_t status){
585     printf("avdtp_handle_sdp_query_failed \n");
586     switch (connection->state){
587         case AVDTP_SIGNALING_W4_SDP_QUERY_FOR_REMOTE_SINK_COMPLETE:
588             avdtp_signaling_emit_connection_established(avdtp_source_callback, connection->avdtp_cid, connection->remote_addr, status);
589             break;
590         case AVDTP_SIGNALING_W4_SDP_QUERY_FOR_REMOTE_SOURCE_COMPLETE:
591             avdtp_signaling_emit_connection_established(avdtp_sink_callback, connection->avdtp_cid, connection->remote_addr, status);
592             break;
593         default:
594             return;
595     }
596     avdtp_finalize_connection(connection);
597     sdp_query_context_avdtp_cid = 0;
598     log_info("SDP query failed with status 0x%02x.", status);
599 }
600 
601 static void avdtp_handle_sdp_query_succeeded(avdtp_connection_t * connection){
602     printf("avdtp_handle_sdp_query_succeeded \n");
603     connection->state = AVDTP_SIGNALING_CONNECTION_W4_L2CAP_CONNECTED;
604 }
605 
606 static void avdtp_handle_sdp_client_query_result(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
607     UNUSED(packet_type);
608     UNUSED(channel);
609     UNUSED(size);
610 
611     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(sdp_query_context_avdtp_cid);
612     if (!connection) {
613         log_error("SDP query, connection with 0x%02x cid not found", sdp_query_context_avdtp_cid);
614         return;
615     }
616 
617     uint8_t status;
618     bool query_succeded = false;
619 
620     switch (connection->state){
621         case AVDTP_SIGNALING_W4_SDP_QUERY_FOR_REMOTE_SINK_COMPLETE:
622             switch (hci_event_packet_get_type(packet)){
623                 case SDP_EVENT_QUERY_ATTRIBUTE_VALUE:
624                     avdtp_handle_sdp_client_query_attribute_value(connection, packet);
625                     return;
626                 case SDP_EVENT_QUERY_COMPLETE:
627                     status = sdp_event_query_complete_get_status(packet);
628                     if (status != ERROR_CODE_SUCCESS) break;
629                     if (!connection->sink_supported) break;
630                     if (connection->avdtp_l2cap_psm == 0) break;
631                     query_succeded = true;
632                     break;
633                 default:
634                     btstack_assert(false);
635                     break;
636             }
637             break;
638         case AVDTP_SIGNALING_W4_SDP_QUERY_FOR_REMOTE_SOURCE_COMPLETE:
639             switch (hci_event_packet_get_type(packet)){
640                 case SDP_EVENT_QUERY_ATTRIBUTE_VALUE:
641                     avdtp_handle_sdp_client_query_attribute_value(connection, packet);
642                     return;
643                 case SDP_EVENT_QUERY_COMPLETE:
644                     status = sdp_event_query_complete_get_status(packet);
645                     if (status != ERROR_CODE_SUCCESS) break;
646                     if (!connection->source_supported) break;
647                     if (connection->avdtp_l2cap_psm == 0) break;
648                     query_succeded = true;
649                     break;
650                 default:
651                     btstack_assert(false);
652                     break;
653             }
654             break;
655         default:
656             // bail out, we must have had an incoming connection in the meantime;
657             return;
658     }
659 
660     if (query_succeded){
661         avdtp_handle_sdp_query_succeeded(connection);
662         l2cap_create_channel(avdtp_packet_handler, connection->remote_addr, connection->avdtp_l2cap_psm, l2cap_max_mtu(), NULL);
663     } else {
664         avdtp_handle_sdp_query_failed(connection, status);
665     }
666 }
667 
668 static avdtp_connection_t * avdtp_handle_incoming_connection(avdtp_connection_t * connection, bd_addr_t event_addr, uint16_t local_cid){
669     if (connection == NULL){
670         uint16_t cid = avdtp_get_next_cid();
671         connection = avdtp_create_connection(event_addr, cid);
672     }
673 
674     if (connection) {
675         connection->state = AVDTP_SIGNALING_CONNECTION_W4_L2CAP_CONNECTED;
676         connection->l2cap_signaling_cid = local_cid;
677         btstack_run_loop_remove_timer(&connection->retry_timer);
678     }
679     return connection;
680 }
681 
682 static avdtp_context_t * avdtp_get_active_contex(void){
683     // assume only one context is active
684     avdtp_context_t * context = NULL;
685     if (avdtp_sink_context != NULL){
686         context = avdtp_sink_context;
687     } else {
688         context = avdtp_source_context;
689     }
690     btstack_assert(context != NULL);
691     return context;
692 }
693 
694 static void avdtp_retry_timer_timeout_handler(btstack_timer_source_t * timer){
695     uint16_t avdtp_cid = (uint16_t)(uintptr_t) btstack_run_loop_get_timer_context(timer);
696 
697     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
698     if (connection == NULL) return;
699 
700     if (connection->state == AVDTP_SIGNALING_CONNECTION_W2_L2CAP_RETRY){
701         connection->state = AVDTP_SIGNALING_CONNECTION_W4_L2CAP_CONNECTED;
702         l2cap_create_channel(&avdtp_packet_handler, connection->remote_addr, connection->avdtp_l2cap_psm, l2cap_max_mtu(), NULL);
703     }
704 }
705 
706 static void avdtp_retry_timer_start(avdtp_connection_t * connection){
707     btstack_run_loop_set_timer_handler(&connection->retry_timer, avdtp_retry_timer_timeout_handler);
708     btstack_run_loop_set_timer_context(&connection->retry_timer, (void *)(uintptr_t)connection->avdtp_cid);
709 
710     // add some jitter/randomness to reconnect delay
711     uint32_t timeout = 100 + (btstack_run_loop_get_time_ms() & 0x7F);
712     btstack_run_loop_set_timer(&connection->retry_timer, timeout);
713     btstack_run_loop_add_timer(&connection->retry_timer);
714 }
715 
716 
717 void avdtp_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
718     bd_addr_t event_addr;
719     uint16_t psm;
720     uint16_t local_cid;
721     uint8_t  status;
722     uint16_t l2cap_mtu;
723 
724     bool accept_streaming_connection;
725     bool outoing_signaling_active;
726     bool decline_connection;
727 
728     avdtp_stream_endpoint_t * stream_endpoint = NULL;
729     avdtp_connection_t * connection = NULL;
730 
731     avdtp_context_t * context = avdtp_get_active_contex();
732 
733     switch (packet_type) {
734         case L2CAP_DATA_PACKET:
735             connection = avdtp_get_connection_for_l2cap_signaling_cid(channel);
736             if (connection){
737                 handle_l2cap_data_packet_for_signaling_connection(connection, packet, size, context);
738                 break;
739             }
740 
741             stream_endpoint = avdtp_get_stream_endpoint_for_l2cap_cid(channel);
742             if (!stream_endpoint){
743                 if (!connection) break;
744                 handle_l2cap_data_packet_for_signaling_connection(connection, packet, size, context);
745                 break;
746             }
747 
748             if (stream_endpoint->connection){
749                 if (channel == stream_endpoint->connection->l2cap_signaling_cid){
750                     handle_l2cap_data_packet_for_signaling_connection(stream_endpoint->connection, packet, size, context);
751                     break;
752                 }
753             }
754 
755             if (channel == stream_endpoint->l2cap_media_cid){
756                 btstack_assert(avdtp_sink_handle_media_data);
757                 (*avdtp_sink_handle_media_data)(avdtp_local_seid(stream_endpoint), packet, size);
758                 break;
759             }
760 
761             if (channel == stream_endpoint->l2cap_reporting_cid){
762                 log_info("L2CAP_DATA_PACKET for reporting: NOT IMPLEMENTED");
763             } else if (channel == stream_endpoint->l2cap_recovery_cid){
764                 log_info("L2CAP_DATA_PACKET for recovery: NOT IMPLEMENTED");
765             } else {
766                 log_error("avdtp packet handler L2CAP_DATA_PACKET: local cid 0x%02x not found", channel);
767             }
768             break;
769 
770         case HCI_EVENT_PACKET:
771             switch (hci_event_packet_get_type(packet)) {
772 
773                 case L2CAP_EVENT_INCOMING_CONNECTION:
774                     l2cap_event_incoming_connection_get_address(packet, event_addr);
775                     local_cid = l2cap_event_incoming_connection_get_local_cid(packet);
776 
777                     outoing_signaling_active = false;
778                     accept_streaming_connection = false;
779 
780                     connection = avdtp_get_connection_for_bd_addr(event_addr);
781                     if (connection != NULL){
782                         switch (connection->state){
783                             case AVDTP_SIGNALING_CONNECTION_W4_L2CAP_DISCONNECTED:
784                             case AVDTP_SIGNALING_CONNECTION_W4_L2CAP_CONNECTED:
785                                 outoing_signaling_active = true;
786                                 connection->incoming_declined = true;
787                                 break;
788                             case AVDTP_SIGNALING_CONNECTION_OPENED:
789                                 outoing_signaling_active = true;
790                                 accept_streaming_connection = true;
791                                 break;
792                             default:
793                                 break;
794                         }
795                     }
796                     log_info("incoming: %s, outoing_signaling_active %d, accept_streaming_connection %d",
797                         bd_addr_to_str(event_addr), outoing_signaling_active, accept_streaming_connection);
798 
799                     decline_connection = outoing_signaling_active && !accept_streaming_connection;
800                     if (outoing_signaling_active == false){
801                         connection = avdtp_handle_incoming_connection(connection, event_addr, local_cid);
802                         if (connection == NULL){
803                             decline_connection = true;
804                         }
805                     } else if (accept_streaming_connection){
806                         if ((connection == NULL) || (connection->configuration_state != AVDTP_CONFIGURATION_STATE_REMOTE_CONFIGURED)) {
807                             decline_connection = true;
808                         } else {
809                             // now, we're only dealing with media connections that are created by remote side - we're acceptor here
810                             stream_endpoint = avdtp_get_stream_endpoint_with_seid(connection->acceptor_local_seid);
811                             if ((stream_endpoint == NULL) || (stream_endpoint->l2cap_media_cid != 0) ) {
812                                 decline_connection = true;
813                             }
814                         }
815                     }
816 
817                     if (decline_connection){
818                         l2cap_decline_connection(local_cid);
819                     } else {
820                         l2cap_accept_connection(local_cid);
821                     }
822                     break;
823 
824                 case L2CAP_EVENT_CHANNEL_OPENED:
825                     btstack_assert(context != NULL);
826 
827                     psm = l2cap_event_channel_opened_get_psm(packet);
828                     if (psm != BLUETOOTH_PSM_AVDTP){
829                         log_info("Unexpected PSM - Not implemented yet, avdtp sink: L2CAP_EVENT_CHANNEL_OPENED ");
830                         return;
831                     }
832 
833                     status = l2cap_event_channel_opened_get_status(packet);
834                     // inform about new l2cap connection
835                     l2cap_event_channel_opened_get_address(packet, event_addr);
836                     local_cid = l2cap_event_channel_opened_get_local_cid(packet);
837                     l2cap_mtu = l2cap_event_channel_opened_get_remote_mtu(packet);
838                     connection = avdtp_get_connection_for_bd_addr(event_addr);
839                     if (connection == NULL){
840                         log_info("L2CAP_EVENT_CHANNEL_OPENED: no connection found for %s", bd_addr_to_str(event_addr));
841                         break;
842                     }
843 
844                     switch (connection->state){
845                         case AVDTP_SIGNALING_CONNECTION_W4_L2CAP_CONNECTED:
846                             switch (status){
847                                 case ERROR_CODE_SUCCESS:
848                                     connection->l2cap_signaling_cid = local_cid;
849                                     connection->incoming_declined = false;
850                                     connection->l2cap_mtu = l2cap_mtu;
851                                     connection->state = AVDTP_SIGNALING_CONNECTION_OPENED;
852                                     log_info("Connection opened l2cap_signaling_cid 0x%02x, avdtp_cid 0x%02x", connection->l2cap_signaling_cid, connection->avdtp_cid);
853                                     avdtp_signaling_emit_connection_established(context->avdtp_callback, connection->avdtp_cid, event_addr, status);
854                                     return;
855                                 case L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_RESOURCES:
856                                     if (connection->incoming_declined == true) {
857                                         log_info("Connection was declined, and the outgoing failed");
858                                         connection->state = AVDTP_SIGNALING_CONNECTION_W2_L2CAP_RETRY;
859                                         connection->incoming_declined = false;
860                                         avdtp_retry_timer_start(connection);
861                                         return;
862                                     }
863                                     break;
864                                 default:
865                                     log_info("Connection to %s failed. status code 0x%02x", bd_addr_to_str(event_addr), status);
866                                     break;
867                             }
868                             avdtp_finalize_connection(connection);
869                             avdtp_signaling_emit_connection_established(context->avdtp_callback, connection->avdtp_cid, event_addr, status);
870                             break;
871 
872                         case AVDTP_SIGNALING_CONNECTION_OPENED:
873                             stream_endpoint = avdtp_get_stream_endpoint_for_signaling_cid(connection->l2cap_signaling_cid);
874                             if (!stream_endpoint){
875                                 log_info("L2CAP_EVENT_CHANNEL_OPENED: stream_endpoint not found for signaling cid 0x%02x", connection->l2cap_signaling_cid);
876                                 return;
877                             }
878                             if (status != ERROR_CODE_SUCCESS){
879                                 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));
880                                 stream_endpoint->state = AVDTP_STREAM_ENDPOINT_IDLE;
881                                 avdtp_streaming_emit_connection_established(stream_endpoint, status);
882                                 break;
883                             }
884                             switch (stream_endpoint->state){
885                                 case AVDTP_STREAM_ENDPOINT_W4_L2CAP_FOR_MEDIA_CONNECTED:
886                                     stream_endpoint->state = AVDTP_STREAM_ENDPOINT_OPENED;
887                                     stream_endpoint->l2cap_media_cid = l2cap_event_channel_opened_get_local_cid(packet);
888                                     stream_endpoint->media_con_handle = l2cap_event_channel_opened_get_handle(packet);
889 
890                                     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));
891                                     avdtp_streaming_emit_connection_established(stream_endpoint, ERROR_CODE_SUCCESS);
892                                     break;
893                                 default:
894                                     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));
895                                     avdtp_streaming_emit_connection_established(stream_endpoint, AVDTP_STREAM_ENDPOINT_IN_WRONG_STATE);
896                                     break;
897                             }
898                             break;
899 
900                         default:
901                             log_info("L2CAP connection to %s ignored: status code 0x%02x, connection state %d", bd_addr_to_str(event_addr), status, connection->state);
902                             break;
903                     }
904                     break;
905 
906                 case L2CAP_EVENT_CHANNEL_CLOSED:
907                     local_cid = l2cap_event_channel_closed_get_local_cid(packet);
908                     stream_endpoint = avdtp_get_stream_endpoint_for_l2cap_cid(local_cid);
909                     connection = avdtp_get_connection_for_l2cap_signaling_cid(local_cid);
910 
911                     log_info("Received L2CAP_EVENT_CHANNEL_CLOSED, cid 0x%2x, connection %p, stream_endpoint %p", local_cid, connection, stream_endpoint);
912 
913                     if (stream_endpoint){
914                         if (stream_endpoint->l2cap_media_cid == local_cid){
915                             connection = stream_endpoint->connection;
916                             if (connection) {
917                                 avdtp_streaming_emit_connection_released(stream_endpoint,
918                                                                          connection->avdtp_cid,
919                                                                          avdtp_local_seid(stream_endpoint));
920                             }
921                             avdtp_reset_stream_endpoint(stream_endpoint);
922                             break;
923                         }
924                         if (stream_endpoint->l2cap_recovery_cid == local_cid){
925                             log_info("L2CAP_EVENT_CHANNEL_CLOSED recovery cid 0x%0x", local_cid);
926                             stream_endpoint->l2cap_recovery_cid = 0;
927                             break;
928                         }
929 
930                         if (stream_endpoint->l2cap_reporting_cid == local_cid){
931                             log_info("L2CAP_EVENT_CHANNEL_CLOSED reporting cid 0x%0x", local_cid);
932                             stream_endpoint->l2cap_reporting_cid = 0;
933                             break;
934                         }
935                     }
936 
937                     if (connection){
938                         btstack_linked_list_iterator_t it;
939                         btstack_linked_list_iterator_init(&it, avdtp_get_stream_endpoints());
940                         while (btstack_linked_list_iterator_has_next(&it)){
941                             stream_endpoint = (avdtp_stream_endpoint_t *)btstack_linked_list_iterator_next(&it);
942                             if (stream_endpoint->connection == connection){
943                                 avdtp_reset_stream_endpoint(stream_endpoint);
944                             }
945                         }
946                         avdtp_signaling_emit_connection_released(context->avdtp_callback, connection->avdtp_cid);
947                         avdtp_finalize_connection(connection);
948                         break;
949                     }
950 
951                     break;
952 
953                 case HCI_EVENT_DISCONNECTION_COMPLETE:
954                     break;
955 
956                 case L2CAP_EVENT_CAN_SEND_NOW:
957                     log_debug("avdtp_packet_handler, L2CAP_EVENT_CAN_SEND_NOW l2cap_cid 0x%02x", channel);
958                     connection = avdtp_get_connection_for_l2cap_signaling_cid(channel);
959                     if (!connection) {
960                         stream_endpoint = avdtp_get_stream_endpoint_for_l2cap_cid(channel);
961                         if (!stream_endpoint->connection) break;
962                         connection = stream_endpoint->connection;
963                     }
964                     avdtp_handle_can_send_now(connection, channel, context);
965                     break;
966                 default:
967                     log_info("Unknown HCI event type %02x", hci_event_packet_get_type(packet));
968                     break;
969             }
970             break;
971 
972         default:
973             // other packet type
974             break;
975     }
976 }
977 
978 uint8_t avdtp_disconnect(uint16_t avdtp_cid){
979     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
980     if (!connection) return AVDTP_CONNECTION_DOES_NOT_EXIST;
981 
982     if (connection->state == AVDTP_SIGNALING_CONNECTION_W4_L2CAP_DISCONNECTED) return ERROR_CODE_SUCCESS;
983 
984     btstack_linked_list_iterator_t it;
985     btstack_linked_list_iterator_init(&it, avdtp_get_stream_endpoints());
986 
987     while (btstack_linked_list_iterator_has_next(&it)){
988         avdtp_stream_endpoint_t * stream_endpoint = (avdtp_stream_endpoint_t *)btstack_linked_list_iterator_next(&it);
989         if (stream_endpoint->connection != connection) continue;
990 
991         switch (stream_endpoint->state){
992             case AVDTP_STREAM_ENDPOINT_OPENED:
993             case AVDTP_STREAM_ENDPOINT_STREAMING:
994                 stream_endpoint->state = AVDTP_STREAM_ENDPOINT_W4_L2CAP_FOR_MEDIA_DISCONNECTED;
995                 l2cap_disconnect(stream_endpoint->l2cap_media_cid, 0);
996                 break;
997             default:
998                 break;
999         }
1000     }
1001 
1002     connection->state = AVDTP_SIGNALING_CONNECTION_W4_L2CAP_DISCONNECTED;
1003     l2cap_disconnect(connection->l2cap_signaling_cid, 0);
1004     return ERROR_CODE_SUCCESS;
1005 }
1006 
1007 uint8_t avdtp_open_stream(uint16_t avdtp_cid, uint8_t local_seid, uint8_t remote_seid){
1008     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
1009     if (!connection){
1010         log_error("avdtp_media_connect: no connection for signaling cid 0x%02x found", avdtp_cid);
1011         return AVDTP_CONNECTION_DOES_NOT_EXIST;
1012     }
1013 
1014     if (connection->state != AVDTP_SIGNALING_CONNECTION_OPENED) {
1015         log_error("avdtp_media_connect: wrong connection state %d", connection->state);
1016         return AVDTP_CONNECTION_IN_WRONG_STATE;
1017     }
1018 
1019     avdtp_stream_endpoint_t * stream_endpoint = avdtp_get_stream_endpoint_with_seid(local_seid);
1020     if (!stream_endpoint) {
1021         log_error("avdtp_media_connect: no stream_endpoint with seid %d found", local_seid);
1022         return AVDTP_SEID_DOES_NOT_EXIST;
1023     }
1024 
1025     if (stream_endpoint->remote_sep.seid != remote_seid){
1026         log_error("avdtp_media_connect: no remote sep with seid %d registered with the stream endpoint", remote_seid);
1027         return AVDTP_SEID_DOES_NOT_EXIST;
1028     }
1029 
1030     if (stream_endpoint->state < AVDTP_STREAM_ENDPOINT_CONFIGURED) return AVDTP_STREAM_ENDPOINT_IN_WRONG_STATE;
1031 
1032     connection->initiator_transaction_label++;
1033     connection->initiator_remote_seid = remote_seid;
1034     connection->initiator_local_seid = local_seid;
1035     stream_endpoint->initiator_config_state = AVDTP_INITIATOR_W2_OPEN_STREAM;
1036     stream_endpoint->state = AVDTP_STREAM_ENDPOINT_W2_REQUEST_OPEN_STREAM;
1037     avdtp_request_can_send_now_initiator(connection, connection->l2cap_signaling_cid);
1038     return ERROR_CODE_SUCCESS;
1039 }
1040 
1041 uint8_t avdtp_start_stream(uint16_t avdtp_cid, uint8_t local_seid){
1042     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
1043     if (!connection){
1044         log_error("avdtp_start_stream: no connection for signaling cid 0x%02x found", avdtp_cid);
1045         return AVDTP_CONNECTION_DOES_NOT_EXIST;
1046     }
1047 
1048     avdtp_stream_endpoint_t * stream_endpoint = avdtp_get_stream_endpoint_with_seid(local_seid);
1049     if (!stream_endpoint) {
1050         log_error("avdtp_start_stream: no stream_endpoint with seid %d found", local_seid);
1051         return AVDTP_SEID_DOES_NOT_EXIST;
1052     }
1053 
1054     if (stream_endpoint->l2cap_media_cid == 0){
1055         log_error("avdtp_start_stream: no media connection for stream_endpoint with seid %d found", local_seid);
1056         return AVDTP_MEDIA_CONNECTION_DOES_NOT_EXIST;
1057     }
1058 
1059     if (!is_avdtp_remote_seid_registered(stream_endpoint)){
1060         log_error("avdtp_media_connect: no remote sep registered with the stream endpoint");
1061         return AVDTP_SEID_DOES_NOT_EXIST;
1062     }
1063 
1064     if (!is_avdtp_remote_seid_registered(stream_endpoint) || stream_endpoint->start_stream == 1){
1065         return ERROR_CODE_COMMAND_DISALLOWED;
1066     }
1067 
1068     stream_endpoint->start_stream = 1;
1069     connection->initiator_local_seid = local_seid;
1070     connection->initiator_remote_seid = stream_endpoint->remote_sep.seid;
1071     avdtp_request_can_send_now_initiator(connection, connection->l2cap_signaling_cid);
1072     return ERROR_CODE_SUCCESS;
1073 }
1074 
1075 uint8_t avdtp_stop_stream(uint16_t avdtp_cid, uint8_t local_seid){
1076     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
1077     if (!connection){
1078         log_error("avdtp_stop_stream: no connection for signaling cid 0x%02x found", avdtp_cid);
1079         return AVDTP_CONNECTION_DOES_NOT_EXIST;
1080     }
1081 
1082     avdtp_stream_endpoint_t * stream_endpoint = avdtp_get_stream_endpoint_with_seid(local_seid);
1083     if (!stream_endpoint) {
1084         log_error("avdtp_stop_stream: no stream_endpoint with seid %d found", local_seid);
1085         return AVDTP_SEID_DOES_NOT_EXIST;
1086     }
1087 
1088     if (stream_endpoint->l2cap_media_cid == 0){
1089         log_error("avdtp_stop_stream: no media connection for stream_endpoint with seid %d found", local_seid);
1090         return AVDTP_MEDIA_CONNECTION_DOES_NOT_EXIST;
1091     }
1092 
1093     if (!is_avdtp_remote_seid_registered(stream_endpoint) || stream_endpoint->stop_stream){
1094         return ERROR_CODE_COMMAND_DISALLOWED;
1095     }
1096 
1097     stream_endpoint->stop_stream = 1;
1098     connection->initiator_local_seid = local_seid;
1099     connection->initiator_remote_seid = stream_endpoint->remote_sep.seid;
1100     avdtp_request_can_send_now_initiator(connection, connection->l2cap_signaling_cid);
1101     return ERROR_CODE_SUCCESS;
1102 }
1103 
1104 uint8_t avdtp_abort_stream(uint16_t avdtp_cid, uint8_t local_seid){
1105     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
1106     if (!connection){
1107         log_error("avdtp_abort_stream: no connection for signaling cid 0x%02x found", avdtp_cid);
1108         return AVDTP_CONNECTION_DOES_NOT_EXIST;
1109     }
1110 
1111     avdtp_stream_endpoint_t * stream_endpoint = avdtp_get_stream_endpoint_with_seid(local_seid);
1112     if (!stream_endpoint) {
1113         log_error("avdtp_abort_stream: no stream_endpoint with seid %d found", local_seid);
1114         return AVDTP_SEID_DOES_NOT_EXIST;
1115     }
1116 
1117     if (stream_endpoint->l2cap_media_cid == 0){
1118         log_error("avdtp_abort_stream: no media connection for stream_endpoint with seid %d found", local_seid);
1119         return AVDTP_MEDIA_CONNECTION_DOES_NOT_EXIST;
1120     }
1121 
1122     if (!is_avdtp_remote_seid_registered(stream_endpoint) || stream_endpoint->abort_stream){
1123         return ERROR_CODE_COMMAND_DISALLOWED;
1124     }
1125 
1126     stream_endpoint->abort_stream = 1;
1127     connection->initiator_local_seid = local_seid;
1128     connection->initiator_remote_seid = stream_endpoint->remote_sep.seid;
1129     avdtp_request_can_send_now_initiator(connection, connection->l2cap_signaling_cid);
1130     return ERROR_CODE_SUCCESS;
1131 }
1132 
1133 uint8_t avdtp_suspend_stream(uint16_t avdtp_cid, uint8_t local_seid){
1134     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
1135     if (!connection){
1136         log_error("avdtp_suspend_stream: no connection for signaling cid 0x%02x found", avdtp_cid);
1137         return AVDTP_CONNECTION_DOES_NOT_EXIST;
1138     }
1139     avdtp_stream_endpoint_t * stream_endpoint = avdtp_get_stream_endpoint_with_seid(local_seid);
1140     if (!stream_endpoint) {
1141         log_error("avdtp_suspend_stream: no stream_endpoint with seid %d found", local_seid);
1142         return AVDTP_SEID_DOES_NOT_EXIST;
1143     }
1144 
1145     if (stream_endpoint->l2cap_media_cid == 0){
1146         log_error("avdtp_suspend_stream: no media connection for stream_endpoint with seid %d found", local_seid);
1147         return AVDTP_MEDIA_CONNECTION_DOES_NOT_EXIST;
1148     }
1149 
1150     if (!is_avdtp_remote_seid_registered(stream_endpoint) || stream_endpoint->suspend_stream){
1151         return ERROR_CODE_COMMAND_DISALLOWED;
1152     }
1153 
1154     stream_endpoint->suspend_stream = 1;
1155     connection->initiator_local_seid = local_seid;
1156     connection->initiator_remote_seid = stream_endpoint->remote_sep.seid;
1157     avdtp_request_can_send_now_initiator(connection, connection->l2cap_signaling_cid);
1158     return ERROR_CODE_SUCCESS;
1159 }
1160 
1161 uint8_t avdtp_discover_stream_endpoints(uint16_t avdtp_cid){
1162     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
1163     if (!connection){
1164         log_error("avdtp_discover_stream_endpoints: no connection for signaling cid 0x%02x found", avdtp_cid);
1165         return AVDTP_CONNECTION_DOES_NOT_EXIST;
1166     }
1167     if ((connection->state != AVDTP_SIGNALING_CONNECTION_OPENED) ||
1168         (connection->initiator_connection_state != AVDTP_SIGNALING_CONNECTION_INITIATOR_IDLE)) {
1169         return AVDTP_CONNECTION_IN_WRONG_STATE;
1170     }
1171 
1172     connection->initiator_transaction_label++;
1173     connection->initiator_connection_state = AVDTP_SIGNALING_CONNECTION_INITIATOR_W2_DISCOVER_SEPS;
1174     return avdtp_request_can_send_now_initiator(connection, connection->l2cap_signaling_cid);
1175 }
1176 
1177 
1178 uint8_t avdtp_get_capabilities(uint16_t avdtp_cid, uint8_t remote_seid){
1179     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
1180     if (!connection){
1181         log_error("No connection for AVDTP cid 0x%02x found", avdtp_cid);
1182         return AVDTP_CONNECTION_DOES_NOT_EXIST;
1183     }
1184     if ((connection->state != AVDTP_SIGNALING_CONNECTION_OPENED) ||
1185         (connection->initiator_connection_state != AVDTP_SIGNALING_CONNECTION_INITIATOR_IDLE)) {
1186         return AVDTP_CONNECTION_IN_WRONG_STATE;
1187     }
1188 
1189     connection->initiator_transaction_label++;
1190     connection->initiator_connection_state = AVDTP_SIGNALING_CONNECTION_INITIATOR_W2_GET_CAPABILITIES;
1191     connection->initiator_remote_seid = remote_seid;
1192     return avdtp_request_can_send_now_initiator(connection, connection->l2cap_signaling_cid);
1193 }
1194 
1195 
1196 uint8_t avdtp_get_all_capabilities(uint16_t avdtp_cid, uint8_t remote_seid){
1197     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
1198     if (!connection){
1199         log_error("No connection for AVDTP cid 0x%02x found", avdtp_cid);
1200         return AVDTP_CONNECTION_DOES_NOT_EXIST;
1201     }
1202     if ((connection->state != AVDTP_SIGNALING_CONNECTION_OPENED) ||
1203         (connection->initiator_connection_state != AVDTP_SIGNALING_CONNECTION_INITIATOR_IDLE)) {
1204         return AVDTP_CONNECTION_IN_WRONG_STATE;
1205     }
1206 
1207     connection->initiator_transaction_label++;
1208     connection->initiator_connection_state = AVDTP_SIGNALING_CONNECTION_INITIATOR_W2_GET_ALL_CAPABILITIES;
1209     connection->initiator_remote_seid = remote_seid;
1210     return avdtp_request_can_send_now_initiator(connection, connection->l2cap_signaling_cid);
1211 }
1212 
1213 uint8_t avdtp_get_configuration(uint16_t avdtp_cid, uint8_t remote_seid){
1214     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
1215     if (!connection){
1216         log_error("No connection for AVDTP cid 0x%02x found", avdtp_cid);
1217         return AVDTP_CONNECTION_DOES_NOT_EXIST;
1218     }
1219     if ((connection->state != AVDTP_SIGNALING_CONNECTION_OPENED) ||
1220         (connection->initiator_connection_state != AVDTP_SIGNALING_CONNECTION_INITIATOR_IDLE)) {
1221         return AVDTP_CONNECTION_IN_WRONG_STATE;
1222     }
1223 
1224     connection->initiator_transaction_label++;
1225     connection->initiator_connection_state = AVDTP_SIGNALING_CONNECTION_INITIATOR_W2_GET_CONFIGURATION;
1226     connection->initiator_remote_seid = remote_seid;
1227     return avdtp_request_can_send_now_initiator(connection, connection->l2cap_signaling_cid);
1228 }
1229 
1230 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){
1231     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
1232     if (!connection){
1233         log_error("No connection for AVDTP cid 0x%02x found", avdtp_cid);
1234         return AVDTP_CONNECTION_DOES_NOT_EXIST;
1235     }
1236     if ((connection->state != AVDTP_SIGNALING_CONNECTION_OPENED) ||
1237         (connection->initiator_connection_state != AVDTP_SIGNALING_CONNECTION_INITIATOR_IDLE)) {
1238         log_error("connection in wrong state, %d, initiator state %d", connection->state, connection->initiator_connection_state);
1239         return AVDTP_CONNECTION_IN_WRONG_STATE;
1240     }
1241     if (connection->configuration_state != AVDTP_CONFIGURATION_STATE_IDLE){
1242         log_info("configuration already started, config state %u", connection->configuration_state);
1243         return AVDTP_CONNECTION_IN_WRONG_STATE;
1244     }
1245 
1246     avdtp_stream_endpoint_t * stream_endpoint = avdtp_get_stream_endpoint_for_seid(local_seid);
1247     if (!stream_endpoint) {
1248         log_error("No initiator stream endpoint for seid %d", local_seid);
1249         return AVDTP_STREAM_ENDPOINT_DOES_NOT_EXIST;
1250     }
1251     if (stream_endpoint->state >= AVDTP_STREAM_ENDPOINT_CONFIGURED){
1252         log_error("Stream endpoint seid %d in wrong state %d", local_seid, stream_endpoint->state);
1253         return AVDTP_STREAM_ENDPOINT_IN_WRONG_STATE;
1254     }
1255 
1256     connection->active_stream_endpoint = (void*) stream_endpoint;
1257     connection->configuration_state = AVDTP_CONFIGURATION_STATE_LOCAL_INITIATED;
1258 
1259     connection->initiator_transaction_label++;
1260     connection->initiator_remote_seid = remote_seid;
1261     connection->initiator_local_seid = local_seid;
1262     stream_endpoint->remote_configuration_bitmap = configured_services_bitmap;
1263     stream_endpoint->remote_configuration = configuration;
1264     stream_endpoint->initiator_config_state = AVDTP_INITIATOR_W2_SET_CONFIGURATION;
1265 
1266     // cache media codec information for SBC
1267     stream_endpoint->media_codec_type = configuration.media_codec.media_codec_type;
1268     if (configuration.media_codec.media_codec_type == AVDTP_CODEC_SBC){
1269         stream_endpoint->media_type = configuration.media_codec.media_type;
1270         (void)memcpy(stream_endpoint->media_codec_sbc_info,
1271                      configuration.media_codec.media_codec_information, 4);
1272     }
1273     return avdtp_request_can_send_now_initiator(connection, connection->l2cap_signaling_cid);
1274 }
1275 
1276 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){
1277     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
1278     if (!connection){
1279         log_error("No connection for AVDTP cid 0x%02x found", avdtp_cid);
1280         return AVDTP_CONNECTION_DOES_NOT_EXIST;
1281     }
1282     //TODO: if opened only app capabilities, enable reconfigure for not opened
1283     if ((connection->state != AVDTP_SIGNALING_CONNECTION_OPENED) ||
1284         (connection->initiator_connection_state != AVDTP_SIGNALING_CONNECTION_INITIATOR_IDLE)) {
1285         return AVDTP_CONNECTION_IN_WRONG_STATE;
1286     }
1287 
1288     avdtp_stream_endpoint_t * stream_endpoint = avdtp_get_stream_endpoint_for_seid(local_seid);
1289     if (!stream_endpoint) {
1290         log_error("avdtp_reconfigure: no initiator stream endpoint for seid %d", local_seid);
1291         return AVDTP_STREAM_ENDPOINT_DOES_NOT_EXIST;
1292     }
1293 
1294     if (!is_avdtp_remote_seid_registered(stream_endpoint)){
1295         log_error("avdtp_reconfigure: no associated remote sep");
1296         return AVDTP_STREAM_ENDPOINT_IN_WRONG_STATE;
1297     }
1298 
1299     connection->initiator_transaction_label++;
1300     connection->initiator_remote_seid = remote_seid;
1301     connection->initiator_local_seid = local_seid;
1302     stream_endpoint->remote_configuration_bitmap = configured_services_bitmap;
1303     stream_endpoint->remote_configuration = configuration;
1304     stream_endpoint->initiator_config_state = AVDTP_INITIATOR_W2_RECONFIGURE_STREAM_WITH_SEID;
1305     return avdtp_request_can_send_now_initiator(connection, connection->l2cap_signaling_cid);
1306 }
1307 
1308 void    avdtp_set_preferred_sampling_frequeny(avdtp_stream_endpoint_t * stream_endpoint, uint32_t sampling_frequency){
1309     stream_endpoint->preferred_sampling_frequency = sampling_frequency;
1310 }
1311 
1312 uint8_t avdtp_choose_sbc_channel_mode(avdtp_stream_endpoint_t * stream_endpoint, uint8_t remote_channel_mode_bitmap){
1313     uint8_t * media_codec = stream_endpoint->sep.capabilities.media_codec.media_codec_information;
1314     uint8_t channel_mode_bitmap = (media_codec[0] & 0x0F) & remote_channel_mode_bitmap;
1315 
1316     uint8_t channel_mode = AVDTP_SBC_STEREO;
1317     if (channel_mode_bitmap & AVDTP_SBC_JOINT_STEREO){
1318         channel_mode = AVDTP_SBC_JOINT_STEREO;
1319     } else if (channel_mode_bitmap & AVDTP_SBC_STEREO){
1320         channel_mode = AVDTP_SBC_STEREO;
1321     } else if (channel_mode_bitmap & AVDTP_SBC_DUAL_CHANNEL){
1322         channel_mode = AVDTP_SBC_DUAL_CHANNEL;
1323     } else if (channel_mode_bitmap & AVDTP_SBC_MONO){
1324         channel_mode = AVDTP_SBC_MONO;
1325     }
1326     return channel_mode;
1327 }
1328 
1329 uint8_t avdtp_choose_sbc_allocation_method(avdtp_stream_endpoint_t * stream_endpoint, uint8_t remote_allocation_method_bitmap){
1330     uint8_t * media_codec = stream_endpoint->sep.capabilities.media_codec.media_codec_information;
1331     uint8_t allocation_method_bitmap = (media_codec[1] & 0x03) & remote_allocation_method_bitmap;
1332 
1333     uint8_t allocation_method = AVDTP_SBC_ALLOCATION_METHOD_LOUDNESS;
1334     if (allocation_method_bitmap & AVDTP_SBC_ALLOCATION_METHOD_LOUDNESS){
1335         allocation_method = AVDTP_SBC_ALLOCATION_METHOD_LOUDNESS;
1336     } else if (allocation_method_bitmap & AVDTP_SBC_ALLOCATION_METHOD_SNR){
1337         allocation_method = AVDTP_SBC_ALLOCATION_METHOD_SNR;
1338     }
1339     return allocation_method;
1340 }
1341 
1342 uint8_t avdtp_stream_endpoint_seid(avdtp_stream_endpoint_t * stream_endpoint){
1343     if (!stream_endpoint) return 0;
1344     return stream_endpoint->sep.seid;
1345 }
1346 uint8_t avdtp_choose_sbc_subbands(avdtp_stream_endpoint_t * stream_endpoint, uint8_t remote_subbands_bitmap){
1347     if (!stream_endpoint) return 0;
1348     uint8_t * media_codec = stream_endpoint->sep.capabilities.media_codec.media_codec_information;
1349     uint8_t subbands_bitmap = ((media_codec[1] >> 2) & 0x03) & remote_subbands_bitmap;
1350 
1351     uint8_t subbands = AVDTP_SBC_SUBBANDS_8;
1352     if (subbands_bitmap & AVDTP_SBC_SUBBANDS_8){
1353         subbands = AVDTP_SBC_SUBBANDS_8;
1354     } else if (subbands_bitmap & AVDTP_SBC_SUBBANDS_4){
1355         subbands = AVDTP_SBC_SUBBANDS_4;
1356     }
1357     return subbands;
1358 }
1359 
1360 uint8_t avdtp_choose_sbc_block_length(avdtp_stream_endpoint_t * stream_endpoint, uint8_t remote_block_length_bitmap){
1361     if (!stream_endpoint) return 0;
1362     uint8_t * media_codec = stream_endpoint->sep.capabilities.media_codec.media_codec_information;
1363     uint8_t block_length_bitmap = (media_codec[1] >> 4) & remote_block_length_bitmap;
1364 
1365     uint8_t block_length = AVDTP_SBC_BLOCK_LENGTH_16;
1366     if (block_length_bitmap & AVDTP_SBC_BLOCK_LENGTH_16){
1367         block_length = AVDTP_SBC_BLOCK_LENGTH_16;
1368     } else if (block_length_bitmap & AVDTP_SBC_BLOCK_LENGTH_12){
1369         block_length = AVDTP_SBC_BLOCK_LENGTH_12;
1370     } else if (block_length_bitmap & AVDTP_SBC_BLOCK_LENGTH_8){
1371         block_length = AVDTP_SBC_BLOCK_LENGTH_8;
1372     } else if (block_length_bitmap & AVDTP_SBC_BLOCK_LENGTH_4){
1373         block_length = AVDTP_SBC_BLOCK_LENGTH_4;
1374     }
1375     return block_length;
1376 }
1377 
1378 uint8_t avdtp_choose_sbc_sampling_frequency(avdtp_stream_endpoint_t * stream_endpoint, uint8_t remote_sampling_frequency_bitmap){
1379     if (!stream_endpoint) return 0;
1380     uint8_t * media_codec = stream_endpoint->sep.capabilities.media_codec.media_codec_information;
1381     uint8_t supported_sampling_frequency_bitmap = (media_codec[0] >> 4) & remote_sampling_frequency_bitmap;
1382 
1383     // use preferred sampling frequency if possible
1384     if ((stream_endpoint->preferred_sampling_frequency == 48000) && (supported_sampling_frequency_bitmap & AVDTP_SBC_48000)){
1385         return AVDTP_SBC_48000;
1386     }
1387     if ((stream_endpoint->preferred_sampling_frequency == 44100) && (supported_sampling_frequency_bitmap & AVDTP_SBC_44100)){
1388         return AVDTP_SBC_44100;
1389     }
1390     if ((stream_endpoint->preferred_sampling_frequency == 32000) && (supported_sampling_frequency_bitmap & AVDTP_SBC_32000)){
1391         return AVDTP_SBC_32000;
1392     }
1393     if ((stream_endpoint->preferred_sampling_frequency == 16000) && (supported_sampling_frequency_bitmap & AVDTP_SBC_16000)){
1394         return AVDTP_SBC_16000;
1395     }
1396 
1397     // otherwise, use highest available
1398     if (supported_sampling_frequency_bitmap & AVDTP_SBC_48000){
1399         return AVDTP_SBC_48000;
1400     }
1401     if (supported_sampling_frequency_bitmap & AVDTP_SBC_44100){
1402         return AVDTP_SBC_44100;
1403     }
1404     if (supported_sampling_frequency_bitmap & AVDTP_SBC_32000){
1405         return AVDTP_SBC_32000;
1406     }
1407     if (supported_sampling_frequency_bitmap & AVDTP_SBC_16000){
1408         return AVDTP_SBC_16000;
1409     }
1410     return AVDTP_SBC_44100; // some default
1411 }
1412 
1413 uint8_t avdtp_choose_sbc_max_bitpool_value(avdtp_stream_endpoint_t * stream_endpoint, uint8_t remote_max_bitpool_value){
1414     if (!stream_endpoint) return 0;
1415     uint8_t * media_codec = stream_endpoint->sep.capabilities.media_codec.media_codec_information;
1416     return btstack_min(media_codec[3], remote_max_bitpool_value);
1417 }
1418 
1419 uint8_t avdtp_choose_sbc_min_bitpool_value(avdtp_stream_endpoint_t * stream_endpoint, uint8_t remote_min_bitpool_value){
1420     if (!stream_endpoint) return 0;
1421     uint8_t * media_codec = stream_endpoint->sep.capabilities.media_codec.media_codec_information;
1422     return btstack_max(media_codec[2], remote_min_bitpool_value);
1423 }
1424 
1425 uint8_t is_avdtp_remote_seid_registered(avdtp_stream_endpoint_t * stream_endpoint){
1426     if (!stream_endpoint) return 0;
1427     if (stream_endpoint->remote_sep.seid == 0) return 0;
1428     if (stream_endpoint->remote_sep.seid > 0x3E) return 0;
1429     return 1;
1430 }
1431