xref: /btstack/src/classic/avdtp.c (revision 79654d96bbff5eddd46f42f4b0bce34dc9bae5d3)
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 btstack_linked_list_t stream_endpoints;
57 
58 static btstack_packet_handler_t avdtp_source_callback;
59 static btstack_packet_handler_t avdtp_sink_callback;
60 static btstack_context_callback_registration_t avdtp_handle_sdp_client_query_request;
61 
62 static uint16_t sdp_query_context_avdtp_cid = 0;
63 
64 static uint16_t stream_endpoints_id_counter = 0;
65 
66 static btstack_linked_list_t connections;
67 static uint16_t transaction_id_counter = 0;
68 
69 static int record_id = -1;
70 static uint8_t   attribute_value[45];
71 static const unsigned int attribute_value_buffer_size = sizeof(attribute_value);
72 
73 static void (*avdtp_sink_handle_media_data)(uint8_t local_seid, uint8_t *packet, uint16_t size);
74 
75 static uint16_t avdtp_cid_counter = 0;
76 
77 static void avdtp_handle_sdp_client_query_result(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
78 
79 btstack_packet_handler_t
80 avdtp_packet_handler_for_stream_endpoint(const avdtp_stream_endpoint_t *stream_endpoint) {
81     return (stream_endpoint->sep.type == AVDTP_SOURCE) ? avdtp_source_callback : avdtp_sink_callback;
82 }
83 
84 void avdtp_emit_sink_and_source(uint8_t * packet, uint16_t size){
85     if (avdtp_source_callback != NULL){
86         (*avdtp_source_callback)(HCI_EVENT_PACKET, 0, packet, size);
87     }
88     if (avdtp_sink_callback != NULL){
89         (*avdtp_sink_callback)(HCI_EVENT_PACKET, 0, packet, size);
90     }
91 }
92 
93 void avdtp_emit_source(uint8_t * packet, uint16_t size){
94     if (avdtp_source_callback != NULL){
95         (*avdtp_source_callback)(HCI_EVENT_PACKET, 0, packet, size);
96     }
97 }
98 
99 btstack_linked_list_t * avdtp_get_stream_endpoints(void){
100     return &stream_endpoints;
101 }
102 
103 btstack_linked_list_t * avdtp_get_connections(void){
104     return &connections;
105 }
106 
107 static avdtp_connection_t * avdtp_get_connection_for_bd_addr(bd_addr_t addr){
108     btstack_linked_list_iterator_t it;
109     btstack_linked_list_iterator_init(&it, &connections);
110     while (btstack_linked_list_iterator_has_next(&it)){
111         avdtp_connection_t * connection = (avdtp_connection_t *)btstack_linked_list_iterator_next(&it);
112         if (memcmp(addr, connection->remote_addr, 6) != 0) continue;
113         return connection;
114     }
115     return NULL;
116 }
117 
118  avdtp_connection_t * avdtp_get_connection_for_avdtp_cid(uint16_t avdtp_cid){
119     btstack_linked_list_iterator_t it;
120     btstack_linked_list_iterator_init(&it, &connections);
121     while (btstack_linked_list_iterator_has_next(&it)){
122         avdtp_connection_t * connection = (avdtp_connection_t *)btstack_linked_list_iterator_next(&it);
123         if (connection->avdtp_cid != avdtp_cid) continue;
124         return connection;
125     }
126     return NULL;
127 }
128 
129 
130 avdtp_stream_endpoint_t * avdtp_get_stream_endpoint_for_seid(uint16_t seid){
131     btstack_linked_list_iterator_t it;
132     btstack_linked_list_iterator_init(&it, avdtp_get_stream_endpoints());
133     while (btstack_linked_list_iterator_has_next(&it)){
134         avdtp_stream_endpoint_t * stream_endpoint = (avdtp_stream_endpoint_t *)btstack_linked_list_iterator_next(&it);
135         if (stream_endpoint->sep.seid == seid){
136             return stream_endpoint;
137         }
138     }
139     return NULL;
140 }
141 
142 avdtp_connection_t * avdtp_get_connection_for_l2cap_signaling_cid(uint16_t l2cap_cid){
143     btstack_linked_list_iterator_t it;
144     btstack_linked_list_iterator_init(&it, &connections);
145     while (btstack_linked_list_iterator_has_next(&it)){
146         avdtp_connection_t * connection = (avdtp_connection_t *)btstack_linked_list_iterator_next(&it);
147         if (connection->l2cap_signaling_cid != l2cap_cid) continue;
148         return connection;
149     }
150     return NULL;
151 }
152 
153 static avdtp_stream_endpoint_t * avdtp_get_stream_endpoint_for_l2cap_cid(uint16_t l2cap_cid){
154     btstack_linked_list_iterator_t it;
155     btstack_linked_list_iterator_init(&it, avdtp_get_stream_endpoints());
156     while (btstack_linked_list_iterator_has_next(&it)){
157         avdtp_stream_endpoint_t * stream_endpoint = (avdtp_stream_endpoint_t *)btstack_linked_list_iterator_next(&it);
158         if (stream_endpoint->l2cap_media_cid == l2cap_cid){
159             return stream_endpoint;
160         }
161         if (stream_endpoint->l2cap_reporting_cid == l2cap_cid){
162             return stream_endpoint;
163         }
164         if (stream_endpoint->l2cap_recovery_cid == l2cap_cid){
165             return stream_endpoint;
166         }
167     }
168     return NULL;
169 }
170 
171 static avdtp_stream_endpoint_t * avdtp_get_stream_endpoint_for_signaling_cid(uint16_t l2cap_cid){
172     btstack_linked_list_iterator_t it;
173     btstack_linked_list_iterator_init(&it, avdtp_get_stream_endpoints());
174     while (btstack_linked_list_iterator_has_next(&it)){
175         avdtp_stream_endpoint_t * stream_endpoint = (avdtp_stream_endpoint_t *)btstack_linked_list_iterator_next(&it);
176         if (stream_endpoint->connection){
177             if (stream_endpoint->connection->l2cap_signaling_cid == l2cap_cid){
178                 return stream_endpoint;
179             }
180         }
181     }
182     return NULL;
183 }
184 
185 uint16_t avdtp_get_next_transaction_label(void){
186     transaction_id_counter++;
187     if (transaction_id_counter == 16){
188         transaction_id_counter = 1;
189     }
190     return transaction_id_counter;
191 }
192 
193 static avdtp_connection_t * avdtp_create_connection(bd_addr_t remote_addr, uint16_t cid){
194     avdtp_connection_t * connection = btstack_memory_avdtp_connection_get();
195     if (!connection){
196         log_error("Not enough memory to create connection");
197         return NULL;
198     }
199     connection->state = AVDTP_SIGNALING_CONNECTION_IDLE;
200     connection->initiator_transaction_label = avdtp_get_next_transaction_label();
201     connection->configuration_state = AVDTP_CONFIGURATION_STATE_IDLE;
202     connection->a2dp_source_discover_seps = false;
203     connection->avdtp_cid = cid;
204     (void)memcpy(connection->remote_addr, remote_addr, 6);
205 
206     btstack_linked_list_add(&connections, (btstack_linked_item_t *) connection);
207     return connection;
208 }
209 
210 static uint16_t avdtp_get_next_cid(void){
211     if (avdtp_cid_counter == 0xffff) {
212         avdtp_cid_counter = 1;
213     } else {
214         avdtp_cid_counter++;
215     }
216     return avdtp_cid_counter;
217 }
218 
219 static uint16_t avdtp_get_next_local_seid(void){
220     if (stream_endpoints_id_counter == 0xffff) {
221         stream_endpoints_id_counter = 1;
222     } else {
223         stream_endpoints_id_counter++;
224     }
225     return stream_endpoints_id_counter;
226 }
227 
228 static void avdtp_handle_start_sdp_client_query(void * context){
229     UNUSED(context);
230 
231     btstack_linked_list_iterator_t it;
232     btstack_linked_list_iterator_init(&it, &connections);
233     while (btstack_linked_list_iterator_has_next(&it)){
234         avdtp_connection_t * connection = (avdtp_connection_t *)btstack_linked_list_iterator_next(&it);
235 
236         switch (connection->state){
237             case AVDTP_SIGNALING_W2_SEND_SDP_QUERY_FOR_REMOTE_SOURCE:
238                 connection->state = AVDTP_SIGNALING_W4_SDP_QUERY_FOR_REMOTE_SOURCE_COMPLETE;
239                 break;
240             case AVDTP_SIGNALING_W2_SEND_SDP_QUERY_FOR_REMOTE_SINK:
241                 connection->state = AVDTP_SIGNALING_W4_SDP_QUERY_FOR_REMOTE_SINK_COMPLETE;
242                 break;
243             case AVDTP_SIGNALING_CONNECTION_OPENED:
244                 if (connection->initiator_connection_state != AVDTP_SIGNALING_CONNECTION_INITIATOR_W2_SEND_SDP_QUERY_THEN_GET_ALL_CAPABILITIES) continue;
245                 connection->initiator_connection_state = AVDTP_SIGNALING_CONNECTION_INITIATOR_W4_SDP_QUERY_COMPLETE_THEN_GET_ALL_CAPABILITIES;
246                 break;
247             default:
248                 continue;
249         }
250         sdp_query_context_avdtp_cid = connection->avdtp_cid;
251         sdp_client_query_uuid16(&avdtp_handle_sdp_client_query_result, (uint8_t *) connection->remote_addr, BLUETOOTH_PROTOCOL_AVDTP);
252         return;
253     }
254 }
255 
256 uint8_t avdtp_connect(bd_addr_t remote, avdtp_role_t role, uint16_t * avdtp_cid){
257     avdtp_connection_t * connection = avdtp_get_connection_for_bd_addr(remote);
258     if (connection){
259         return ERROR_CODE_COMMAND_DISALLOWED;
260     }
261 
262     uint16_t cid = avdtp_get_next_cid();
263     if (avdtp_cid != NULL) {
264         *avdtp_cid = cid;
265     }
266 
267     connection = avdtp_create_connection(remote, cid);
268     if (!connection) return BTSTACK_MEMORY_ALLOC_FAILED;
269 
270     connection->avdtp_cid = cid;
271 
272     connection->avdtp_l2cap_psm = 0;
273     connection->avdtp_version  = 0;
274     connection->sink_supported = false;
275     connection->source_supported = false;
276 
277     switch (role){
278         case AVDTP_ROLE_SOURCE:
279             connection->state = AVDTP_SIGNALING_W2_SEND_SDP_QUERY_FOR_REMOTE_SINK;
280             break;
281         case AVDTP_ROLE_SINK:
282             connection->state = AVDTP_SIGNALING_W2_SEND_SDP_QUERY_FOR_REMOTE_SOURCE;
283             break;
284         default:
285             btstack_assert(false);
286             return ERROR_CODE_COMMAND_DISALLOWED;
287     }
288 
289     avdtp_handle_sdp_client_query_request.callback = &avdtp_handle_start_sdp_client_query;
290     // ignore ERROR_CODE_COMMAND_DISALLOWED because in that case, we already have requested an SDP callback
291     (void) sdp_client_register_query_callback(&avdtp_handle_sdp_client_query_request);
292     return ERROR_CODE_SUCCESS;
293 }
294 
295 
296 void avdtp_register_sink_packet_handler(btstack_packet_handler_t callback){
297     btstack_assert(callback != NULL);
298     avdtp_sink_callback = callback;
299 }
300 
301 void avdtp_register_source_packet_handler(btstack_packet_handler_t callback){
302     btstack_assert(callback != NULL);
303     avdtp_source_callback = callback;
304 }
305 
306 void avdtp_register_media_transport_category(avdtp_stream_endpoint_t * stream_endpoint){
307     if (!stream_endpoint){
308         log_error("Stream endpoint with given seid is not registered.");
309         return;
310     }
311     uint16_t bitmap = store_bit16(stream_endpoint->sep.registered_service_categories, AVDTP_MEDIA_TRANSPORT, 1);
312     stream_endpoint->sep.registered_service_categories = bitmap;
313 }
314 
315 void avdtp_register_reporting_category(avdtp_stream_endpoint_t * stream_endpoint){
316     if (!stream_endpoint){
317         log_error("Stream endpoint with given seid is not registered.");
318         return;
319     }
320     uint16_t bitmap = store_bit16(stream_endpoint->sep.registered_service_categories, AVDTP_REPORTING, 1);
321     stream_endpoint->sep.registered_service_categories = bitmap;
322 }
323 
324 void avdtp_register_delay_reporting_category(avdtp_stream_endpoint_t * stream_endpoint){
325     if (!stream_endpoint){
326         log_error("Stream endpoint with given seid is not registered.");
327         return;
328     }
329     uint16_t bitmap = store_bit16(stream_endpoint->sep.registered_service_categories, AVDTP_DELAY_REPORTING, 1);
330     stream_endpoint->sep.registered_service_categories = bitmap;
331 }
332 
333 void avdtp_register_recovery_category(avdtp_stream_endpoint_t * stream_endpoint, uint8_t maximum_recovery_window_size, uint8_t maximum_number_media_packets){
334     if (!stream_endpoint){
335         log_error("Stream endpoint with given seid is not registered.");
336         return;
337     }
338     uint16_t bitmap = store_bit16(stream_endpoint->sep.registered_service_categories, AVDTP_RECOVERY, 1);
339     stream_endpoint->sep.registered_service_categories = bitmap;
340     stream_endpoint->sep.capabilities.recovery.recovery_type = 0x01; // 0x01 = RFC2733
341     stream_endpoint->sep.capabilities.recovery.maximum_recovery_window_size = maximum_recovery_window_size;
342     stream_endpoint->sep.capabilities.recovery.maximum_number_media_packets = maximum_number_media_packets;
343 }
344 
345 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){
346     if (!stream_endpoint){
347         log_error("Stream endpoint with given seid is not registered.");
348         return;
349     }
350     uint16_t bitmap = store_bit16(stream_endpoint->sep.registered_service_categories, AVDTP_CONTENT_PROTECTION, 1);
351     stream_endpoint->sep.registered_service_categories = bitmap;
352     stream_endpoint->sep.capabilities.content_protection.cp_type = cp_type;
353     (void)memcpy(stream_endpoint->sep.capabilities.content_protection.cp_type_value,
354                  cp_type_value,
355                  btstack_min(cp_type_value_len, AVDTP_MAX_CONTENT_PROTECTION_TYPE_VALUE_LEN));
356     stream_endpoint->sep.capabilities.content_protection.cp_type_value_len = btstack_min(cp_type_value_len, AVDTP_MAX_CONTENT_PROTECTION_TYPE_VALUE_LEN);
357 }
358 
359 void avdtp_register_header_compression_category(avdtp_stream_endpoint_t * stream_endpoint, uint8_t back_ch, uint8_t media, uint8_t recovery){
360     if (!stream_endpoint){
361         log_error("Stream endpoint with given seid is not registered.");
362         return;
363     }
364     uint16_t bitmap = store_bit16(stream_endpoint->sep.registered_service_categories, AVDTP_HEADER_COMPRESSION, 1);
365     stream_endpoint->sep.registered_service_categories = bitmap;
366     stream_endpoint->sep.capabilities.header_compression.back_ch = back_ch;
367     stream_endpoint->sep.capabilities.header_compression.media = media;
368     stream_endpoint->sep.capabilities.header_compression.recovery = recovery;
369 }
370 
371 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){
372     if (!stream_endpoint){
373         log_error("Stream endpoint with given seid is not registered.");
374         return;
375     }
376     uint16_t bitmap = store_bit16(stream_endpoint->sep.registered_service_categories, AVDTP_MEDIA_CODEC, 1);
377     stream_endpoint->sep.registered_service_categories = bitmap;
378     stream_endpoint->sep.capabilities.media_codec.media_type = media_type;
379     stream_endpoint->sep.capabilities.media_codec.media_codec_type = media_codec_type;
380     stream_endpoint->sep.capabilities.media_codec.media_codec_information = media_codec_info;
381     stream_endpoint->sep.capabilities.media_codec.media_codec_information_len = media_codec_info_len;
382 }
383 
384 void avdtp_register_multiplexing_category(avdtp_stream_endpoint_t * stream_endpoint, uint8_t fragmentation){
385     if (!stream_endpoint){
386         log_error("Stream endpoint with given seid is not registered.");
387         return;
388     }
389     uint16_t bitmap = store_bit16(stream_endpoint->sep.registered_service_categories, AVDTP_MULTIPLEXING, 1);
390     stream_endpoint->sep.registered_service_categories = bitmap;
391     stream_endpoint->sep.capabilities.multiplexing_mode.fragmentation = fragmentation;
392 }
393 
394 void avdtp_register_media_handler(void (*callback)(uint8_t local_seid, uint8_t *packet, uint16_t size)){
395     avdtp_sink_handle_media_data = callback;
396 }
397 
398 /* START: tracking can send now requests per l2cap cid */
399 static void avdtp_handle_can_send_now(uint16_t l2cap_cid) {
400 
401 	log_debug("avdtp_packet_handler, L2CAP_EVENT_CAN_SEND_NOW l2cap_cid 0x%02x", l2cap_cid);
402 
403 	// get signaling connection for l2cap cid
404 	avdtp_connection_t * connection = avdtp_get_connection_for_l2cap_signaling_cid(l2cap_cid);
405 
406 	if (connection != NULL) {
407 		if (connection->wait_to_send_acceptor) {
408 			log_debug("call avdtp_acceptor_stream_config_subsm_run %p", connection);
409 			connection->wait_to_send_acceptor = false;
410 			avdtp_acceptor_stream_config_subsm_run(connection);
411 		} else if (connection->wait_to_send_initiator) {
412 			log_debug("call avdtp_initiator_stream_config_subsm_handle_can_send_now_signaling %p", connection);
413 			connection->wait_to_send_initiator = false;
414 			avdtp_initiator_stream_config_subsm_handle_can_send_now_signaling(connection);
415 		}
416 		bool more_to_send = connection->wait_to_send_acceptor || connection->wait_to_send_initiator;
417 		if (more_to_send){
418 			l2cap_request_can_send_now_event(l2cap_cid);
419 		}
420 		return;
421 	}
422 
423 	// get stream endpoint connection for l2cap cid
424 	avdtp_stream_endpoint_t * stream_endpoint = avdtp_get_stream_endpoint_for_l2cap_cid(l2cap_cid);
425 	if (stream_endpoint != NULL) {
426 		log_debug("call avdtp_initiator_stream_config_subsm_handle_can_send_now_stream_endpoint %p", stream_endpoint);
427 		if (stream_endpoint->request_can_send_now) {
428 			stream_endpoint->request_can_send_now = 0;
429 			avdtp_initiator_stream_config_subsm_handle_can_send_now_stream_endpoint(stream_endpoint);
430 		}
431 		bool more_to_send = stream_endpoint->request_can_send_now != 0;
432 		if (more_to_send){
433 			l2cap_request_can_send_now_event(l2cap_cid);
434 		}
435 	}
436 }
437 /* END: tracking can send now requests per l2cap cid */
438 
439 
440 avdtp_stream_endpoint_t * avdtp_create_stream_endpoint(avdtp_sep_type_t sep_type, avdtp_media_type_t media_type){
441     avdtp_stream_endpoint_t * stream_endpoint = btstack_memory_avdtp_stream_endpoint_get();
442     if (!stream_endpoint){
443         log_error("Not enough memory to create stream endpoint");
444         return NULL;
445     }
446     stream_endpoint->sep.seid = avdtp_get_next_local_seid();
447     stream_endpoint->sep.media_type = media_type;
448     stream_endpoint->sep.type = sep_type;
449     btstack_linked_list_add(avdtp_get_stream_endpoints(), (btstack_linked_item_t *) stream_endpoint);
450     return stream_endpoint;
451 }
452 
453 void avdtp_finalize_stream_endpoint(avdtp_stream_endpoint_t * stream_endpoint){
454     btstack_linked_list_remove(avdtp_get_stream_endpoints(), (btstack_linked_item_t* ) stream_endpoint);
455     btstack_memory_avdtp_stream_endpoint_free(stream_endpoint);
456 }
457 
458 static void
459 handle_l2cap_data_packet_for_signaling_connection(avdtp_connection_t *connection, uint8_t *packet, uint16_t size) {
460     if (size < 2) return;
461 
462     uint16_t offset;
463     avdtp_message_type_t message_type = avdtp_get_signaling_packet_type(packet);
464     switch (message_type){
465         case AVDTP_CMD_MSG:
466             offset = avdtp_read_signaling_header(&connection->acceptor_signaling_packet, packet, size);
467             avdtp_acceptor_stream_config_subsm(connection, packet, size, offset);
468             break;
469         default:
470             offset = avdtp_read_signaling_header(&connection->initiator_signaling_packet, packet, size);
471             avdtp_initiator_stream_config_subsm(connection, packet, size, offset);
472             break;
473     }
474 }
475 
476 static void avdtp_handle_sdp_client_query_attribute_value(avdtp_connection_t * connection, uint8_t *packet){
477     des_iterator_t des_list_it;
478     des_iterator_t prot_it;
479 
480     // Handle new SDP record
481     if (sdp_event_query_attribute_byte_get_record_id(packet) != record_id) {
482         record_id = sdp_event_query_attribute_byte_get_record_id(packet);
483         // log_info("SDP Record: Nr: %d", record_id);
484     }
485 
486     if (sdp_event_query_attribute_byte_get_attribute_length(packet) <= attribute_value_buffer_size) {
487         attribute_value[sdp_event_query_attribute_byte_get_data_offset(packet)] = sdp_event_query_attribute_byte_get_data(packet);
488 
489         if ((uint16_t)(sdp_event_query_attribute_byte_get_data_offset(packet)+1) == sdp_event_query_attribute_byte_get_attribute_length(packet)) {
490 
491             switch(sdp_event_query_attribute_byte_get_attribute_id(packet)) {
492 
493                 case BLUETOOTH_ATTRIBUTE_SERVICE_CLASS_ID_LIST:
494                     if (de_get_element_type(attribute_value) != DE_DES) break;
495                     for (des_iterator_init(&des_list_it, attribute_value); des_iterator_has_more(&des_list_it); des_iterator_next(&des_list_it)) {
496                         uint8_t * element = des_iterator_get_element(&des_list_it);
497                         if (de_get_element_type(element) != DE_UUID) continue;
498                         uint32_t uuid = de_get_uuid32(element);
499                         switch (uuid){
500                             case BLUETOOTH_SERVICE_CLASS_AUDIO_SOURCE:
501                                 connection->source_supported = true;
502                                 log_info("source_supported");
503                                 break;
504                             case BLUETOOTH_SERVICE_CLASS_AUDIO_SINK:
505                                 connection->sink_supported = true;
506                                 log_info("sink_supported");
507                                 break;
508                             default:
509                                 break;
510                         }
511                     }
512                     break;
513 
514                 case BLUETOOTH_ATTRIBUTE_PROTOCOL_DESCRIPTOR_LIST:
515                     // log_info("SDP Attribute: 0x%04x", sdp_event_query_attribute_byte_get_attribute_id(packet));
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       *des_element;
518                         uint8_t       *element;
519                         uint32_t       uuid;
520 
521                         if (des_iterator_get_type(&des_list_it) != DE_DES) continue;
522 
523                         des_element = des_iterator_get_element(&des_list_it);
524                         des_iterator_init(&prot_it, des_element);
525                         element = des_iterator_get_element(&prot_it);
526 
527                         if (de_get_element_type(element) != DE_UUID) continue;
528 
529                         uuid = de_get_uuid32(element);
530                         des_iterator_next(&prot_it);
531                         // we assume that the even if there are both roles supported, remote device uses the same psm and avdtp version for both
532                         switch (uuid){
533                             case BLUETOOTH_PROTOCOL_L2CAP:
534                                 if (!des_iterator_has_more(&prot_it)) continue;
535                                 de_element_get_uint16(des_iterator_get_element(&prot_it), &connection->avdtp_l2cap_psm);
536                                 break;
537                             case BLUETOOTH_PROTOCOL_AVDTP:
538                                 if (!des_iterator_has_more(&prot_it)) continue;
539                                 de_element_get_uint16(des_iterator_get_element(&prot_it), &connection->avdtp_version);
540                                 log_info("avdtp version 0x%02x", connection->avdtp_version);
541                                 break;
542                             default:
543                                 break;
544                         }
545                     }
546                     break;
547 
548                 default:
549                     break;
550             }
551         }
552     } else {
553         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));
554     }
555 
556 }
557 
558 static void avdtp_finalize_connection(avdtp_connection_t * connection){
559     btstack_run_loop_remove_timer(&connection->retry_timer);
560     btstack_linked_list_remove(&connections, (btstack_linked_item_t*) connection);
561     btstack_memory_avdtp_connection_free(connection);
562 }
563 
564 static void avdtp_handle_sdp_query_failed(avdtp_connection_t * connection, uint8_t status){
565     switch (connection->state){
566         case AVDTP_SIGNALING_W4_SDP_QUERY_FOR_REMOTE_SINK_COMPLETE:
567         case AVDTP_SIGNALING_W4_SDP_QUERY_FOR_REMOTE_SOURCE_COMPLETE:
568             avdtp_signaling_emit_connection_established(connection->avdtp_cid, connection->remote_addr, connection->con_handle, status);
569             break;
570 
571         case AVDTP_SIGNALING_CONNECTION_OPENED:
572             // SDP query failed: try query that must be supported
573             connection->initiator_connection_state = AVDTP_SIGNALING_CONNECTION_INITIATOR_W2_GET_CAPABILITIES;
574 			avdtp_request_can_send_now_initiator(connection);
575             return;
576 
577         default:
578             btstack_assert(false);
579             break;
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     log_info("avdtp_handle_sdp_query_succeeded: state %d", connection->state);
588 
589     switch (connection->state){
590         case AVDTP_SIGNALING_CONNECTION_OPENED:
591             if (connection->avdtp_version < 0x0103){
592                 connection->initiator_connection_state = AVDTP_SIGNALING_CONNECTION_INITIATOR_W2_GET_CAPABILITIES;
593             } else {
594                 connection->initiator_connection_state = AVDTP_SIGNALING_CONNECTION_INITIATOR_W2_GET_ALL_CAPABILITIES;
595             }
596 			avdtp_request_can_send_now_initiator(connection);
597             break;
598         default:
599             connection->state = AVDTP_SIGNALING_CONNECTION_W4_L2CAP_CONNECTED;
600             l2cap_create_channel(avdtp_packet_handler, connection->remote_addr, connection->avdtp_l2cap_psm, l2cap_max_mtu(), NULL);
601             break;
602     }
603 }
604 
605 static void avdtp_handle_sdp_client_query_result(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
606     UNUSED(packet_type);
607     UNUSED(channel);
608     UNUSED(size);
609 
610     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(sdp_query_context_avdtp_cid);
611     if (!connection) {
612         log_error("SDP query, connection with 0x%02x cid not found", sdp_query_context_avdtp_cid);
613         return;
614     }
615 
616     uint8_t status = ERROR_CODE_SUCCESS;
617     switch (connection->state){
618         case AVDTP_SIGNALING_W4_SDP_QUERY_FOR_REMOTE_SINK_COMPLETE:
619             switch (hci_event_packet_get_type(packet)){
620                 case SDP_EVENT_QUERY_ATTRIBUTE_VALUE:
621                     avdtp_handle_sdp_client_query_attribute_value(connection, packet);
622                     return;
623                 case SDP_EVENT_QUERY_COMPLETE:
624                     status = sdp_event_query_complete_get_status(packet);
625                     if (status != ERROR_CODE_SUCCESS) break;
626                     if (!connection->sink_supported) {
627                         status = ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
628                         break;
629                     }
630                     if (connection->avdtp_l2cap_psm == 0) {
631                         status = ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
632                         break;
633                     }
634                     break;
635                 default:
636                     btstack_assert(false);
637                     return;
638             }
639             break;
640         case AVDTP_SIGNALING_W4_SDP_QUERY_FOR_REMOTE_SOURCE_COMPLETE:
641             switch (hci_event_packet_get_type(packet)){
642                 case SDP_EVENT_QUERY_ATTRIBUTE_VALUE:
643                     avdtp_handle_sdp_client_query_attribute_value(connection, packet);
644                     return;
645                 case SDP_EVENT_QUERY_COMPLETE:
646                     status = sdp_event_query_complete_get_status(packet);
647                     if (status != ERROR_CODE_SUCCESS) break;
648                     if (!connection->source_supported) {
649                         status = ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
650                         break;
651                     }
652                     if (connection->avdtp_l2cap_psm == 0) {
653                         status = ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
654                         break;
655                     }
656                     break;
657                 default:
658                     btstack_assert(false);
659                     return;
660             }
661             break;
662 
663         case AVDTP_SIGNALING_CONNECTION_OPENED:
664             switch (hci_event_packet_get_type(packet)){
665                 case SDP_EVENT_QUERY_ATTRIBUTE_VALUE:
666                     avdtp_handle_sdp_client_query_attribute_value(connection, packet);
667                     return;
668                 case SDP_EVENT_QUERY_COMPLETE:
669                     status = sdp_event_query_complete_get_status(packet);
670                     break;
671                 default:
672                     btstack_assert(false);
673                     return;
674             }
675             break;
676 
677         default:
678             // bail out, we must have had an incoming connection in the meantime; just trigger next sdp query on complete
679             if (hci_event_packet_get_type(packet) == SDP_EVENT_QUERY_COMPLETE){
680                 (void) sdp_client_register_query_callback(&avdtp_handle_sdp_client_query_request);
681             }
682             return;
683     }
684 
685     if (status == ERROR_CODE_SUCCESS){
686         avdtp_handle_sdp_query_succeeded(connection);
687     } else {
688         avdtp_handle_sdp_query_failed(connection, status);
689     }
690 
691     // register the SDP Query request to check if there is another connection waiting for the query
692     // ignore ERROR_CODE_COMMAND_DISALLOWED because in that case, we already have requested an SDP callback
693     (void) sdp_client_register_query_callback(&avdtp_handle_sdp_client_query_request);
694 }
695 
696 static avdtp_connection_t * avdtp_handle_incoming_connection(avdtp_connection_t * connection, bd_addr_t event_addr, hci_con_handle_t con_handle, uint16_t local_cid){
697     if (connection == NULL){
698         uint16_t cid = avdtp_get_next_cid();
699         connection = avdtp_create_connection(event_addr, cid);
700     }
701 
702     if (connection) {
703         connection->state = AVDTP_SIGNALING_CONNECTION_W4_L2CAP_CONNECTED;
704         connection->l2cap_signaling_cid = local_cid;
705         connection->con_handle = con_handle;
706         btstack_run_loop_remove_timer(&connection->retry_timer);
707     }
708     return connection;
709 }
710 
711 static void avdtp_retry_timer_timeout_handler(btstack_timer_source_t * timer){
712     uint16_t avdtp_cid = (uint16_t)(uintptr_t) btstack_run_loop_get_timer_context(timer);
713 
714     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
715     if (connection == NULL) return;
716 
717     if (connection->state == AVDTP_SIGNALING_CONNECTION_W2_L2CAP_RETRY){
718         connection->state = AVDTP_SIGNALING_CONNECTION_W4_L2CAP_CONNECTED;
719         l2cap_create_channel(&avdtp_packet_handler, connection->remote_addr, connection->avdtp_l2cap_psm, l2cap_max_mtu(), NULL);
720     }
721 }
722 
723 static void avdtp_retry_timer_start(avdtp_connection_t * connection){
724     btstack_run_loop_set_timer_handler(&connection->retry_timer, avdtp_retry_timer_timeout_handler);
725     btstack_run_loop_set_timer_context(&connection->retry_timer, (void *)(uintptr_t)connection->avdtp_cid);
726 
727     // add some jitter/randomness to reconnect delay
728     uint32_t timeout = 100 + (btstack_run_loop_get_time_ms() & 0x7F);
729     btstack_run_loop_set_timer(&connection->retry_timer, timeout);
730     btstack_run_loop_add_timer(&connection->retry_timer);
731 }
732 
733 
734 void avdtp_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
735     bd_addr_t event_addr;
736     uint16_t psm;
737     uint16_t local_cid;
738     uint8_t  status;
739     uint16_t l2cap_mtu;
740     hci_con_handle_t con_handle;
741 
742     bool accept_streaming_connection;
743     bool outoing_signaling_active;
744     bool decline_connection;
745 
746     avdtp_stream_endpoint_t * stream_endpoint = NULL;
747     avdtp_connection_t * connection = NULL;
748 
749     switch (packet_type) {
750         case L2CAP_DATA_PACKET:
751             connection = avdtp_get_connection_for_l2cap_signaling_cid(channel);
752             if (connection){
753                 handle_l2cap_data_packet_for_signaling_connection(connection, packet, size);
754                 break;
755             }
756 
757             stream_endpoint = avdtp_get_stream_endpoint_for_l2cap_cid(channel);
758             if (!stream_endpoint){
759                 if (!connection) break;
760                 handle_l2cap_data_packet_for_signaling_connection(connection, packet, size);
761                 break;
762             }
763 
764             if (stream_endpoint->connection){
765                 if (channel == stream_endpoint->connection->l2cap_signaling_cid){
766                     handle_l2cap_data_packet_for_signaling_connection(stream_endpoint->connection, packet, size);
767                     break;
768                 }
769             }
770 
771             if (channel == stream_endpoint->l2cap_media_cid){
772                 btstack_assert(avdtp_sink_handle_media_data);
773                 (*avdtp_sink_handle_media_data)(avdtp_local_seid(stream_endpoint), packet, size);
774                 break;
775             }
776 
777             if (channel == stream_endpoint->l2cap_reporting_cid){
778                 log_info("L2CAP_DATA_PACKET for reporting: NOT IMPLEMENTED");
779             } else if (channel == stream_endpoint->l2cap_recovery_cid){
780                 log_info("L2CAP_DATA_PACKET for recovery: NOT IMPLEMENTED");
781             } else {
782                 log_error("avdtp packet handler L2CAP_DATA_PACKET: local cid 0x%02x not found", channel);
783             }
784             break;
785 
786         case HCI_EVENT_PACKET:
787             switch (hci_event_packet_get_type(packet)) {
788 
789                 case L2CAP_EVENT_INCOMING_CONNECTION:
790                     l2cap_event_incoming_connection_get_address(packet, event_addr);
791                     local_cid = l2cap_event_incoming_connection_get_local_cid(packet);
792                     con_handle = l2cap_event_incoming_connection_get_handle(packet);
793                     outoing_signaling_active = false;
794                     accept_streaming_connection = false;
795 
796                     connection = avdtp_get_connection_for_bd_addr(event_addr);
797                     if (connection != NULL){
798                         switch (connection->state){
799                             case AVDTP_SIGNALING_CONNECTION_W4_L2CAP_DISCONNECTED:
800                             case AVDTP_SIGNALING_CONNECTION_W4_L2CAP_CONNECTED:
801                                 outoing_signaling_active = true;
802                                 connection->incoming_declined = true;
803                                 break;
804                             case AVDTP_SIGNALING_CONNECTION_OPENED:
805                                 outoing_signaling_active = true;
806                                 accept_streaming_connection = true;
807                                 break;
808                             default:
809                                 break;
810                         }
811                     }
812                     log_info("incoming: %s, outoing_signaling_active %d, accept_streaming_connection %d",
813                         bd_addr_to_str(event_addr), outoing_signaling_active, accept_streaming_connection);
814 
815                     decline_connection = outoing_signaling_active && !accept_streaming_connection;
816                     if (outoing_signaling_active == false){
817                         connection = avdtp_handle_incoming_connection(connection, event_addr, con_handle, local_cid);
818                         if (connection == NULL){
819                             decline_connection = true;
820                         }
821                     } else if (accept_streaming_connection){
822                         if ((connection == NULL) || (connection->configuration_state != AVDTP_CONFIGURATION_STATE_REMOTE_CONFIGURED)) {
823                             decline_connection = true;
824                         } else {
825                             // now, we're only dealing with media connections that are created by remote side - we're acceptor here
826                             stream_endpoint = avdtp_get_stream_endpoint_for_seid(connection->acceptor_local_seid);
827                             if ((stream_endpoint == NULL) || (stream_endpoint->l2cap_media_cid != 0) ) {
828                                 decline_connection = true;
829                             }
830                         }
831                     }
832 
833                     if (decline_connection){
834                         l2cap_decline_connection(local_cid);
835                     } else {
836                         l2cap_accept_connection(local_cid);
837                     }
838                     break;
839 
840                 case L2CAP_EVENT_CHANNEL_OPENED:
841 
842                     psm = l2cap_event_channel_opened_get_psm(packet);
843                     if (psm != BLUETOOTH_PSM_AVDTP){
844                         log_info("Unexpected PSM - Not implemented yet, avdtp sink: L2CAP_EVENT_CHANNEL_OPENED ");
845                         return;
846                     }
847 
848                     status = l2cap_event_channel_opened_get_status(packet);
849                     // inform about new l2cap connection
850                     l2cap_event_channel_opened_get_address(packet, event_addr);
851                     local_cid = l2cap_event_channel_opened_get_local_cid(packet);
852                     l2cap_mtu = l2cap_event_channel_opened_get_remote_mtu(packet);
853                     connection = avdtp_get_connection_for_bd_addr(event_addr);
854                     if (connection == NULL){
855                         log_info("L2CAP_EVENT_CHANNEL_OPENED: no connection found for %s", bd_addr_to_str(event_addr));
856                         break;
857                     }
858 
859                     con_handle = l2cap_event_channel_opened_get_handle(packet);
860 
861                     switch (connection->state){
862                         case AVDTP_SIGNALING_CONNECTION_W4_L2CAP_CONNECTED:
863                             switch (status){
864                                 case ERROR_CODE_SUCCESS:
865                                     connection->l2cap_signaling_cid = local_cid;
866                                     connection->incoming_declined = false;
867                                     connection->l2cap_mtu = l2cap_mtu;
868                                     connection->con_handle = con_handle;
869                                     connection->state = AVDTP_SIGNALING_CONNECTION_OPENED;
870                                     log_info("Connection opened l2cap_signaling_cid 0x%02x, avdtp_cid 0x%02x, con_handle 0x%02x", connection->l2cap_signaling_cid, connection->avdtp_cid, con_handle);
871                                     avdtp_signaling_emit_connection_established(connection->avdtp_cid, event_addr, con_handle, status);
872                                     return;
873                                 case L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_RESOURCES:
874                                     if (connection->incoming_declined == true) {
875                                         log_info("Connection was declined, and the outgoing failed");
876                                         connection->state = AVDTP_SIGNALING_CONNECTION_W2_L2CAP_RETRY;
877                                         connection->incoming_declined = false;
878                                         avdtp_retry_timer_start(connection);
879                                         return;
880                                     }
881                                     break;
882                                 default:
883                                     log_info("Connection to %s failed. status code 0x%02x", bd_addr_to_str(event_addr), status);
884                                     break;
885                             }
886                             avdtp_signaling_emit_connection_established(connection->avdtp_cid, event_addr, con_handle, status);
887                             avdtp_finalize_connection(connection);
888                             break;
889 
890                         case AVDTP_SIGNALING_CONNECTION_OPENED:
891                             stream_endpoint = avdtp_get_stream_endpoint_for_signaling_cid(connection->l2cap_signaling_cid);
892                             if (!stream_endpoint){
893                                 log_info("L2CAP_EVENT_CHANNEL_OPENED: stream_endpoint not found for signaling cid 0x%02x", connection->l2cap_signaling_cid);
894                                 return;
895                             }
896                             if (status != ERROR_CODE_SUCCESS){
897                                 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));
898                                 stream_endpoint->state = AVDTP_STREAM_ENDPOINT_IDLE;
899                                 avdtp_streaming_emit_connection_established(stream_endpoint, status);
900                                 break;
901                             }
902                             switch (stream_endpoint->state){
903                                 case AVDTP_STREAM_ENDPOINT_W4_L2CAP_FOR_MEDIA_CONNECTED:
904                                     stream_endpoint->state = AVDTP_STREAM_ENDPOINT_OPENED;
905                                     stream_endpoint->l2cap_media_cid = l2cap_event_channel_opened_get_local_cid(packet);
906                                     stream_endpoint->media_con_handle = l2cap_event_channel_opened_get_handle(packet);
907 
908                                     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));
909                                     avdtp_streaming_emit_connection_established(stream_endpoint, ERROR_CODE_SUCCESS);
910                                     break;
911                                 default:
912                                     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));
913                                     avdtp_streaming_emit_connection_established(stream_endpoint, ERROR_CODE_COMMAND_DISALLOWED);
914                                     break;
915                             }
916                             break;
917 
918                         default:
919                             log_info("L2CAP connection to %s ignored: status code 0x%02x, connection state %d", bd_addr_to_str(event_addr), status, connection->state);
920                             break;
921                     }
922                     break;
923 
924                 case L2CAP_EVENT_CHANNEL_CLOSED:
925                     local_cid = l2cap_event_channel_closed_get_local_cid(packet);
926                     stream_endpoint = avdtp_get_stream_endpoint_for_l2cap_cid(local_cid);
927                     connection = avdtp_get_connection_for_l2cap_signaling_cid(local_cid);
928 
929                     log_info("Received L2CAP_EVENT_CHANNEL_CLOSED, cid 0x%2x, connection %p, stream_endpoint %p", local_cid, connection, stream_endpoint);
930 
931                     if (stream_endpoint){
932                         if (stream_endpoint->l2cap_media_cid == local_cid){
933                             connection = stream_endpoint->connection;
934                             if (connection) {
935                                 avdtp_streaming_emit_connection_released(stream_endpoint,
936                                                                          connection->avdtp_cid,
937                                                                          avdtp_local_seid(stream_endpoint));
938                             }
939                             avdtp_reset_stream_endpoint(stream_endpoint);
940                             connection->configuration_state = AVDTP_CONFIGURATION_STATE_IDLE;
941                             break;
942                         }
943                         if (stream_endpoint->l2cap_recovery_cid == local_cid){
944                             log_info("L2CAP_EVENT_CHANNEL_CLOSED recovery cid 0x%0x", local_cid);
945                             stream_endpoint->l2cap_recovery_cid = 0;
946                             break;
947                         }
948 
949                         if (stream_endpoint->l2cap_reporting_cid == local_cid){
950                             log_info("L2CAP_EVENT_CHANNEL_CLOSED reporting cid 0x%0x", local_cid);
951                             stream_endpoint->l2cap_reporting_cid = 0;
952                             break;
953                         }
954                     }
955 
956                     if (connection){
957                         btstack_linked_list_iterator_t it;
958                         btstack_linked_list_iterator_init(&it, avdtp_get_stream_endpoints());
959                         while (btstack_linked_list_iterator_has_next(&it)){
960                             stream_endpoint = (avdtp_stream_endpoint_t *)btstack_linked_list_iterator_next(&it);
961                             if (stream_endpoint->connection == connection){
962                                 avdtp_reset_stream_endpoint(stream_endpoint);
963                             }
964                         }
965                         avdtp_signaling_emit_connection_released(connection->avdtp_cid);
966                         avdtp_finalize_connection(connection);
967                         break;
968                     }
969                     break;
970 
971                 case L2CAP_EVENT_CAN_SEND_NOW:
972                     log_debug("avdtp_packet_handler, L2CAP_EVENT_CAN_SEND_NOW l2cap_cid 0x%02x", channel);
973 					avdtp_handle_can_send_now(channel);
974                     break;
975                 default:
976                     log_info("Unknown HCI event type %02x", hci_event_packet_get_type(packet));
977                     break;
978             }
979             break;
980 
981         default:
982             // other packet type
983             break;
984     }
985 }
986 
987 uint8_t avdtp_disconnect(uint16_t avdtp_cid){
988     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
989     if (!connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
990 
991     if (connection->state == AVDTP_SIGNALING_CONNECTION_W4_L2CAP_DISCONNECTED) return ERROR_CODE_SUCCESS;
992 
993     btstack_linked_list_iterator_t it;
994     btstack_linked_list_iterator_init(&it, avdtp_get_stream_endpoints());
995 
996     while (btstack_linked_list_iterator_has_next(&it)){
997         avdtp_stream_endpoint_t * stream_endpoint = (avdtp_stream_endpoint_t *)btstack_linked_list_iterator_next(&it);
998         if (stream_endpoint->connection != connection) continue;
999 
1000         switch (stream_endpoint->state){
1001             case AVDTP_STREAM_ENDPOINT_OPENED:
1002             case AVDTP_STREAM_ENDPOINT_STREAMING:
1003                 stream_endpoint->state = AVDTP_STREAM_ENDPOINT_W4_L2CAP_FOR_MEDIA_DISCONNECTED;
1004                 l2cap_disconnect(stream_endpoint->l2cap_media_cid, 0);
1005                 break;
1006             default:
1007                 break;
1008         }
1009     }
1010 
1011     connection->state = AVDTP_SIGNALING_CONNECTION_W4_L2CAP_DISCONNECTED;
1012     l2cap_disconnect(connection->l2cap_signaling_cid, 0);
1013     return ERROR_CODE_SUCCESS;
1014 }
1015 
1016 uint8_t avdtp_open_stream(uint16_t avdtp_cid, uint8_t local_seid, uint8_t remote_seid){
1017     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
1018     if (!connection){
1019         log_error("avdtp_media_connect: no connection for signaling cid 0x%02x found", avdtp_cid);
1020         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1021     }
1022 
1023     if (connection->state != AVDTP_SIGNALING_CONNECTION_OPENED) {
1024         log_error("avdtp_media_connect: wrong connection state %d", connection->state);
1025         return ERROR_CODE_COMMAND_DISALLOWED;
1026     }
1027 
1028     avdtp_stream_endpoint_t * stream_endpoint = avdtp_get_stream_endpoint_for_seid(local_seid);
1029     if (!stream_endpoint) {
1030         log_error("avdtp_media_connect: no stream_endpoint with seid %d found", local_seid);
1031         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1032     }
1033 
1034     if (stream_endpoint->remote_sep.seid != remote_seid){
1035         log_error("avdtp_media_connect: no remote sep with seid %d registered with the stream endpoint", remote_seid);
1036         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1037     }
1038 
1039     if (stream_endpoint->state < AVDTP_STREAM_ENDPOINT_CONFIGURED) return ERROR_CODE_COMMAND_DISALLOWED;
1040 
1041     connection->initiator_transaction_label= avdtp_get_next_transaction_label();
1042     connection->initiator_remote_seid = remote_seid;
1043     connection->initiator_local_seid = local_seid;
1044     stream_endpoint->initiator_config_state = AVDTP_INITIATOR_W2_OPEN_STREAM;
1045     stream_endpoint->state = AVDTP_STREAM_ENDPOINT_W2_REQUEST_OPEN_STREAM;
1046 	avdtp_request_can_send_now_initiator(connection);
1047     return ERROR_CODE_SUCCESS;
1048 }
1049 
1050 uint8_t avdtp_start_stream(uint16_t avdtp_cid, uint8_t local_seid){
1051     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
1052     if (!connection){
1053         log_error("avdtp_start_stream: no connection for signaling cid 0x%02x found", avdtp_cid);
1054         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1055     }
1056 
1057     avdtp_stream_endpoint_t * stream_endpoint = avdtp_get_stream_endpoint_for_seid(local_seid);
1058     if (!stream_endpoint) {
1059         log_error("avdtp_start_stream: no stream_endpoint with seid %d found", local_seid);
1060         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1061     }
1062 
1063     if (stream_endpoint->l2cap_media_cid == 0){
1064         log_error("avdtp_start_stream: no media connection for stream_endpoint with seid %d found", local_seid);
1065         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1066     }
1067 
1068     if (!is_avdtp_remote_seid_registered(stream_endpoint)){
1069         log_error("avdtp_media_connect: no remote sep registered with the stream endpoint");
1070         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1071     }
1072 
1073     if (!is_avdtp_remote_seid_registered(stream_endpoint) || stream_endpoint->start_stream == 1){
1074         return ERROR_CODE_COMMAND_DISALLOWED;
1075     }
1076 
1077     stream_endpoint->start_stream = 1;
1078     connection->initiator_local_seid = local_seid;
1079     connection->initiator_remote_seid = stream_endpoint->remote_sep.seid;
1080 	avdtp_request_can_send_now_initiator(connection);
1081     return ERROR_CODE_SUCCESS;
1082 }
1083 
1084 uint8_t avdtp_stop_stream(uint16_t avdtp_cid, uint8_t local_seid){
1085     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
1086     if (!connection){
1087         log_error("avdtp_stop_stream: no connection for signaling cid 0x%02x found", avdtp_cid);
1088         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1089     }
1090 
1091     avdtp_stream_endpoint_t * stream_endpoint = avdtp_get_stream_endpoint_for_seid(local_seid);
1092     if (!stream_endpoint) {
1093         log_error("avdtp_stop_stream: no stream_endpoint with seid %d found", local_seid);
1094         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1095     }
1096 
1097     if (stream_endpoint->l2cap_media_cid == 0){
1098         log_error("avdtp_stop_stream: no media connection for stream_endpoint with seid %d found", local_seid);
1099         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1100     }
1101 
1102     if (!is_avdtp_remote_seid_registered(stream_endpoint) || stream_endpoint->close_stream){
1103         return ERROR_CODE_COMMAND_DISALLOWED;
1104     }
1105 
1106     stream_endpoint->close_stream = 1;
1107     connection->initiator_local_seid = local_seid;
1108     connection->initiator_remote_seid = stream_endpoint->remote_sep.seid;
1109 	avdtp_request_can_send_now_initiator(connection);
1110     return ERROR_CODE_SUCCESS;
1111 }
1112 
1113 uint8_t avdtp_abort_stream(uint16_t avdtp_cid, uint8_t local_seid){
1114     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
1115     if (!connection){
1116         log_error("avdtp_abort_stream: no connection for signaling cid 0x%02x found", avdtp_cid);
1117         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1118     }
1119 
1120     avdtp_stream_endpoint_t * stream_endpoint = avdtp_get_stream_endpoint_for_seid(local_seid);
1121     if (!stream_endpoint) {
1122         log_error("avdtp_abort_stream: no stream_endpoint with seid %d found", local_seid);
1123         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1124     }
1125 
1126     if (stream_endpoint->l2cap_media_cid == 0){
1127         log_error("avdtp_abort_stream: no media connection for stream_endpoint with seid %d found", local_seid);
1128         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1129     }
1130 
1131     if (!is_avdtp_remote_seid_registered(stream_endpoint) || stream_endpoint->abort_stream){
1132         return ERROR_CODE_COMMAND_DISALLOWED;
1133     }
1134 
1135     stream_endpoint->abort_stream = 1;
1136     connection->initiator_local_seid = local_seid;
1137     connection->initiator_remote_seid = stream_endpoint->remote_sep.seid;
1138 	avdtp_request_can_send_now_initiator(connection);
1139     return ERROR_CODE_SUCCESS;
1140 }
1141 
1142 uint8_t avdtp_suspend_stream(uint16_t avdtp_cid, uint8_t local_seid){
1143     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
1144     if (!connection){
1145         log_error("avdtp_suspend_stream: no connection for signaling cid 0x%02x found", avdtp_cid);
1146         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1147     }
1148     avdtp_stream_endpoint_t * stream_endpoint = avdtp_get_stream_endpoint_for_seid(local_seid);
1149     if (!stream_endpoint) {
1150         log_error("avdtp_suspend_stream: no stream_endpoint with seid %d found", local_seid);
1151         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1152     }
1153 
1154     if (stream_endpoint->l2cap_media_cid == 0){
1155         log_error("avdtp_suspend_stream: no media connection for stream_endpoint with seid %d found", local_seid);
1156         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1157     }
1158 
1159     if (!is_avdtp_remote_seid_registered(stream_endpoint) || stream_endpoint->suspend_stream){
1160         return ERROR_CODE_COMMAND_DISALLOWED;
1161     }
1162 
1163     stream_endpoint->suspend_stream = 1;
1164     connection->initiator_local_seid = local_seid;
1165     connection->initiator_remote_seid = stream_endpoint->remote_sep.seid;
1166 	avdtp_request_can_send_now_initiator(connection);
1167     return ERROR_CODE_SUCCESS;
1168 }
1169 
1170 uint8_t avdtp_discover_stream_endpoints(uint16_t avdtp_cid){
1171     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
1172     if (!connection){
1173         log_error("avdtp_discover_stream_endpoints: no connection for signaling cid 0x%02x found", avdtp_cid);
1174         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1175     }
1176     if ((connection->state != AVDTP_SIGNALING_CONNECTION_OPENED) ||
1177         (connection->initiator_connection_state != AVDTP_SIGNALING_CONNECTION_INITIATOR_IDLE)) {
1178         return ERROR_CODE_COMMAND_DISALLOWED;
1179     }
1180 
1181     connection->initiator_transaction_label= avdtp_get_next_transaction_label();
1182     connection->initiator_connection_state = AVDTP_SIGNALING_CONNECTION_INITIATOR_W2_DISCOVER_SEPS;
1183     return avdtp_request_can_send_now_initiator(connection);
1184 }
1185 
1186 
1187 uint8_t avdtp_get_capabilities(uint16_t avdtp_cid, uint8_t remote_seid){
1188     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
1189     if (!connection){
1190         log_error("No connection for AVDTP cid 0x%02x found", avdtp_cid);
1191         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1192     }
1193     if ((connection->state != AVDTP_SIGNALING_CONNECTION_OPENED) ||
1194         (connection->initiator_connection_state != AVDTP_SIGNALING_CONNECTION_INITIATOR_IDLE)) {
1195         return ERROR_CODE_COMMAND_DISALLOWED;
1196     }
1197 
1198     connection->initiator_transaction_label= avdtp_get_next_transaction_label();
1199     connection->initiator_connection_state = AVDTP_SIGNALING_CONNECTION_INITIATOR_W2_GET_CAPABILITIES;
1200     connection->initiator_remote_seid = remote_seid;
1201     return avdtp_request_can_send_now_initiator(connection);
1202 }
1203 
1204 
1205 uint8_t avdtp_get_all_capabilities(uint16_t avdtp_cid, uint8_t remote_seid){
1206     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
1207     if (!connection){
1208         log_error("No connection for AVDTP cid 0x%02x found", avdtp_cid);
1209         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1210     }
1211     if ((connection->state != AVDTP_SIGNALING_CONNECTION_OPENED) ||
1212         (connection->initiator_connection_state != AVDTP_SIGNALING_CONNECTION_INITIATOR_IDLE)) {
1213         return ERROR_CODE_COMMAND_DISALLOWED;
1214     }
1215 
1216     connection->initiator_transaction_label= avdtp_get_next_transaction_label();
1217     connection->initiator_remote_seid = remote_seid;
1218 
1219     if (connection->avdtp_version == 0){
1220         connection->initiator_connection_state = AVDTP_SIGNALING_CONNECTION_INITIATOR_W2_SEND_SDP_QUERY_THEN_GET_ALL_CAPABILITIES;
1221         avdtp_handle_sdp_client_query_request.callback = &avdtp_handle_start_sdp_client_query;
1222         // ignore ERROR_CODE_COMMAND_DISALLOWED because in that case, we already have requested an SDP callback
1223         (void) sdp_client_register_query_callback(&avdtp_handle_sdp_client_query_request);
1224         return ERROR_CODE_SUCCESS;
1225     } else {
1226         // AVDTP version lower then 1.3 supports only get capabilities command
1227         if (connection->avdtp_version < 0x103){
1228             connection->initiator_connection_state = AVDTP_SIGNALING_CONNECTION_INITIATOR_W2_GET_CAPABILITIES;
1229         } else {
1230             connection->initiator_connection_state = AVDTP_SIGNALING_CONNECTION_INITIATOR_W2_GET_ALL_CAPABILITIES;
1231         }
1232         return avdtp_request_can_send_now_initiator(connection);
1233     }
1234 }
1235 
1236 uint8_t avdtp_get_configuration(uint16_t avdtp_cid, uint8_t remote_seid){
1237     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
1238     if (!connection){
1239         log_error("No connection for AVDTP cid 0x%02x found", avdtp_cid);
1240         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1241     }
1242     if ((connection->state != AVDTP_SIGNALING_CONNECTION_OPENED) ||
1243         (connection->initiator_connection_state != AVDTP_SIGNALING_CONNECTION_INITIATOR_IDLE)) {
1244         return ERROR_CODE_COMMAND_DISALLOWED;
1245     }
1246 
1247     connection->initiator_transaction_label= avdtp_get_next_transaction_label();
1248     connection->initiator_connection_state = AVDTP_SIGNALING_CONNECTION_INITIATOR_W2_GET_CONFIGURATION;
1249     connection->initiator_remote_seid = remote_seid;
1250     return avdtp_request_can_send_now_initiator(connection);
1251 }
1252 
1253 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){
1254     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
1255     if (!connection){
1256         log_error("No connection for AVDTP cid 0x%02x found", avdtp_cid);
1257         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1258     }
1259     if ((connection->state != AVDTP_SIGNALING_CONNECTION_OPENED) ||
1260         (connection->initiator_connection_state != AVDTP_SIGNALING_CONNECTION_INITIATOR_IDLE)) {
1261         log_error("connection in wrong state, %d, initiator state %d", connection->state, connection->initiator_connection_state);
1262         return ERROR_CODE_COMMAND_DISALLOWED;
1263     }
1264     if (connection->configuration_state != AVDTP_CONFIGURATION_STATE_IDLE){
1265         log_info("configuration already started, config state %u", connection->configuration_state);
1266         return ERROR_CODE_COMMAND_DISALLOWED;
1267     }
1268 
1269     avdtp_stream_endpoint_t * stream_endpoint = avdtp_get_stream_endpoint_for_seid(local_seid);
1270     if (!stream_endpoint) {
1271         log_error("No initiator stream endpoint for seid %d", local_seid);
1272         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1273     }
1274     if (stream_endpoint->state >= AVDTP_STREAM_ENDPOINT_CONFIGURED){
1275         log_error("Stream endpoint seid %d in wrong state %d", local_seid, stream_endpoint->state);
1276         return ERROR_CODE_COMMAND_DISALLOWED;
1277     }
1278 
1279     connection->active_stream_endpoint = (void*) stream_endpoint;
1280     connection->configuration_state = AVDTP_CONFIGURATION_STATE_LOCAL_INITIATED;
1281 
1282     connection->initiator_transaction_label= avdtp_get_next_transaction_label();
1283     connection->initiator_remote_seid = remote_seid;
1284     connection->initiator_local_seid = local_seid;
1285     stream_endpoint->remote_configuration_bitmap = configured_services_bitmap;
1286     stream_endpoint->remote_configuration = configuration;
1287     stream_endpoint->initiator_config_state = AVDTP_INITIATOR_W2_SET_CONFIGURATION;
1288 
1289 	log_debug("SE %p, initiator_config_state: 0x%02x", stream_endpoint, stream_endpoint->initiator_config_state);
1290 
1291     return avdtp_request_can_send_now_initiator(connection);
1292 }
1293 
1294 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){
1295     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
1296     if (!connection){
1297         log_error("No connection for AVDTP cid 0x%02x found", avdtp_cid);
1298         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1299     }
1300     //TODO: if opened only app capabilities, enable reconfigure for not opened
1301     if ((connection->state != AVDTP_SIGNALING_CONNECTION_OPENED) ||
1302         (connection->initiator_connection_state != AVDTP_SIGNALING_CONNECTION_INITIATOR_IDLE)) {
1303         return ERROR_CODE_COMMAND_DISALLOWED;
1304     }
1305 
1306     avdtp_stream_endpoint_t * stream_endpoint = avdtp_get_stream_endpoint_for_seid(local_seid);
1307     if (!stream_endpoint) {
1308         log_error("avdtp_reconfigure: no initiator stream endpoint for seid %d", local_seid);
1309         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1310     }
1311 
1312     if (!is_avdtp_remote_seid_registered(stream_endpoint)){
1313         log_error("avdtp_reconfigure: no associated remote sep");
1314         return ERROR_CODE_COMMAND_DISALLOWED;
1315     }
1316 
1317     connection->initiator_transaction_label= avdtp_get_next_transaction_label();
1318     connection->initiator_remote_seid = remote_seid;
1319     connection->initiator_local_seid = local_seid;
1320     stream_endpoint->remote_configuration_bitmap = configured_services_bitmap;
1321     stream_endpoint->remote_configuration = configuration;
1322     stream_endpoint->initiator_config_state = AVDTP_INITIATOR_W2_RECONFIGURE_STREAM_WITH_SEID;
1323     return avdtp_request_can_send_now_initiator(connection);
1324 }
1325 
1326 void    avdtp_set_preferred_sampling_frequeny(avdtp_stream_endpoint_t * stream_endpoint, uint32_t sampling_frequency){
1327     stream_endpoint->preferred_sampling_frequency = sampling_frequency;
1328 }
1329 
1330 void    avdtp_set_preferred_channel_mode(avdtp_stream_endpoint_t * stream_endpoint, uint8_t channel_mode){
1331     stream_endpoint->preferred_channel_mode = channel_mode;
1332 }
1333 
1334 
1335 uint8_t avdtp_choose_sbc_channel_mode(avdtp_stream_endpoint_t * stream_endpoint, uint8_t remote_channel_mode_bitmap){
1336     uint8_t * media_codec = stream_endpoint->sep.capabilities.media_codec.media_codec_information;
1337     uint8_t channel_mode_bitmap = (media_codec[0] & 0x0F) & remote_channel_mode_bitmap;
1338 
1339     uint8_t channel_mode = AVDTP_SBC_STEREO;
1340     // use preferred channel mode if possible
1341     if (stream_endpoint->preferred_channel_mode == AVDTP_SBC_JOINT_STEREO){
1342         return AVDTP_SBC_JOINT_STEREO;
1343     }
1344     if (stream_endpoint->preferred_channel_mode == AVDTP_SBC_STEREO){
1345         return AVDTP_SBC_STEREO;
1346     }
1347     if (stream_endpoint->preferred_channel_mode == AVDTP_SBC_DUAL_CHANNEL){
1348         return AVDTP_SBC_DUAL_CHANNEL;
1349     }
1350     if (stream_endpoint->preferred_channel_mode == AVDTP_SBC_MONO){
1351         return AVDTP_SBC_MONO;
1352     }
1353 
1354 
1355     if (channel_mode_bitmap & AVDTP_SBC_JOINT_STEREO){
1356         channel_mode = AVDTP_SBC_JOINT_STEREO;
1357     } else if (channel_mode_bitmap & AVDTP_SBC_STEREO){
1358         channel_mode = AVDTP_SBC_STEREO;
1359     } else if (channel_mode_bitmap & AVDTP_SBC_DUAL_CHANNEL){
1360         channel_mode = AVDTP_SBC_DUAL_CHANNEL;
1361     } else if (channel_mode_bitmap & AVDTP_SBC_MONO){
1362         channel_mode = AVDTP_SBC_MONO;
1363     }
1364     return channel_mode;
1365 }
1366 
1367 uint8_t avdtp_choose_sbc_allocation_method(avdtp_stream_endpoint_t * stream_endpoint, uint8_t remote_allocation_method_bitmap){
1368     uint8_t * media_codec = stream_endpoint->sep.capabilities.media_codec.media_codec_information;
1369     uint8_t allocation_method_bitmap = (media_codec[1] & 0x03) & remote_allocation_method_bitmap;
1370 
1371     uint8_t allocation_method = AVDTP_SBC_ALLOCATION_METHOD_LOUDNESS;
1372     if (allocation_method_bitmap & AVDTP_SBC_ALLOCATION_METHOD_LOUDNESS){
1373         allocation_method = AVDTP_SBC_ALLOCATION_METHOD_LOUDNESS;
1374     } else if (allocation_method_bitmap & AVDTP_SBC_ALLOCATION_METHOD_SNR){
1375         allocation_method = AVDTP_SBC_ALLOCATION_METHOD_SNR;
1376     }
1377     return allocation_method;
1378 }
1379 
1380 uint8_t avdtp_stream_endpoint_seid(avdtp_stream_endpoint_t * stream_endpoint){
1381     if (!stream_endpoint) return 0;
1382     return stream_endpoint->sep.seid;
1383 }
1384 uint8_t avdtp_choose_sbc_subbands(avdtp_stream_endpoint_t * stream_endpoint, uint8_t remote_subbands_bitmap){
1385     if (!stream_endpoint) return 0;
1386     uint8_t * media_codec = stream_endpoint->sep.capabilities.media_codec.media_codec_information;
1387     uint8_t subbands_bitmap = ((media_codec[1] >> 2) & 0x03) & remote_subbands_bitmap;
1388 
1389     uint8_t subbands = AVDTP_SBC_SUBBANDS_8;
1390     if (subbands_bitmap & AVDTP_SBC_SUBBANDS_8){
1391         subbands = AVDTP_SBC_SUBBANDS_8;
1392     } else if (subbands_bitmap & AVDTP_SBC_SUBBANDS_4){
1393         subbands = AVDTP_SBC_SUBBANDS_4;
1394     }
1395     return subbands;
1396 }
1397 
1398 uint8_t avdtp_choose_sbc_block_length(avdtp_stream_endpoint_t * stream_endpoint, uint8_t remote_block_length_bitmap){
1399     if (!stream_endpoint) return 0;
1400     uint8_t * media_codec = stream_endpoint->sep.capabilities.media_codec.media_codec_information;
1401     uint8_t block_length_bitmap = (media_codec[1] >> 4) & remote_block_length_bitmap;
1402 
1403     uint8_t block_length = AVDTP_SBC_BLOCK_LENGTH_16;
1404     if (block_length_bitmap & AVDTP_SBC_BLOCK_LENGTH_16){
1405         block_length = AVDTP_SBC_BLOCK_LENGTH_16;
1406     } else if (block_length_bitmap & AVDTP_SBC_BLOCK_LENGTH_12){
1407         block_length = AVDTP_SBC_BLOCK_LENGTH_12;
1408     } else if (block_length_bitmap & AVDTP_SBC_BLOCK_LENGTH_8){
1409         block_length = AVDTP_SBC_BLOCK_LENGTH_8;
1410     } else if (block_length_bitmap & AVDTP_SBC_BLOCK_LENGTH_4){
1411         block_length = AVDTP_SBC_BLOCK_LENGTH_4;
1412     }
1413     return block_length;
1414 }
1415 
1416 uint8_t avdtp_choose_sbc_sampling_frequency(avdtp_stream_endpoint_t * stream_endpoint, uint8_t remote_sampling_frequency_bitmap){
1417     if (!stream_endpoint) return 0;
1418     uint8_t * media_codec = stream_endpoint->sep.capabilities.media_codec.media_codec_information;
1419     uint8_t supported_sampling_frequency_bitmap = (media_codec[0] >> 4) & remote_sampling_frequency_bitmap;
1420 
1421     // use preferred sampling frequency if possible
1422     if ((stream_endpoint->preferred_sampling_frequency == 48000) && (supported_sampling_frequency_bitmap & AVDTP_SBC_48000)){
1423         return AVDTP_SBC_48000;
1424     }
1425     if ((stream_endpoint->preferred_sampling_frequency == 44100) && (supported_sampling_frequency_bitmap & AVDTP_SBC_44100)){
1426         return AVDTP_SBC_44100;
1427     }
1428     if ((stream_endpoint->preferred_sampling_frequency == 32000) && (supported_sampling_frequency_bitmap & AVDTP_SBC_32000)){
1429         return AVDTP_SBC_32000;
1430     }
1431     if ((stream_endpoint->preferred_sampling_frequency == 16000) && (supported_sampling_frequency_bitmap & AVDTP_SBC_16000)){
1432         return AVDTP_SBC_16000;
1433     }
1434 
1435     // otherwise, use highest available
1436     if (supported_sampling_frequency_bitmap & AVDTP_SBC_48000){
1437         return AVDTP_SBC_48000;
1438     }
1439     if (supported_sampling_frequency_bitmap & AVDTP_SBC_44100){
1440         return AVDTP_SBC_44100;
1441     }
1442     if (supported_sampling_frequency_bitmap & AVDTP_SBC_32000){
1443         return AVDTP_SBC_32000;
1444     }
1445     if (supported_sampling_frequency_bitmap & AVDTP_SBC_16000){
1446         return AVDTP_SBC_16000;
1447     }
1448     return AVDTP_SBC_44100; // some default
1449 }
1450 
1451 uint8_t avdtp_choose_sbc_max_bitpool_value(avdtp_stream_endpoint_t * stream_endpoint, uint8_t remote_max_bitpool_value){
1452     if (!stream_endpoint) return 0;
1453     uint8_t * media_codec = stream_endpoint->sep.capabilities.media_codec.media_codec_information;
1454     return btstack_min(media_codec[3], remote_max_bitpool_value);
1455 }
1456 
1457 uint8_t avdtp_choose_sbc_min_bitpool_value(avdtp_stream_endpoint_t * stream_endpoint, uint8_t remote_min_bitpool_value){
1458     if (!stream_endpoint) return 0;
1459     uint8_t * media_codec = stream_endpoint->sep.capabilities.media_codec.media_codec_information;
1460     return btstack_max(media_codec[2], remote_min_bitpool_value);
1461 }
1462 
1463 uint8_t is_avdtp_remote_seid_registered(avdtp_stream_endpoint_t * stream_endpoint){
1464     if (!stream_endpoint) return 0;
1465     if (stream_endpoint->remote_sep.seid == 0) return 0;
1466     if (stream_endpoint->remote_sep.seid > 0x3E) return 0;
1467     return 1;
1468 }
1469 
1470 void avdtp_init(void){
1471     static bool l2cap_registered = false;
1472     if (!l2cap_registered){
1473         l2cap_registered = true;
1474         l2cap_register_service(&avdtp_packet_handler, BLUETOOTH_PSM_AVDTP, 0xffff, gap_get_security_level());
1475     }
1476 }
1477