xref: /btstack/src/classic/avdtp.c (revision be78df3b6c7394390fa6d2bc04f991dd7ac2de2c)
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 BLUEKITCHEN
24  * GMBH 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_util.h"
51 #include "classic/avdtp_acceptor.h"
52 #include "classic/avdtp_initiator.h"
53 #include "classic/avdtp_util.h"
54 #include "classic/sdp_client.h"
55 #include "classic/sdp_util.h"
56 
57 // higher layer callbacks
58 static btstack_packet_handler_t avdtp_source_callback;
59 static btstack_packet_handler_t avdtp_sink_callback;
60 
61 static void (*avdtp_sink_handle_media_data)(uint8_t local_seid, uint8_t *packet, uint16_t size);
62 
63 static uint8_t (*avdtp_sink_media_config_validator)(const avdtp_stream_endpoint_t * stream_endpoint, const uint8_t * event, uint16_t size);
64 static uint8_t (*avdtp_source_media_config_validator)(const avdtp_stream_endpoint_t * stream_endpoint, const uint8_t * event, uint16_t size);
65 
66 // sdp query
67 static btstack_context_callback_registration_t avdtp_handle_sdp_client_query_request;
68 static uint16_t avdtp_sdp_query_context_avdtp_cid = 0;
69 
70 // registered stream endpoints
71 static btstack_linked_list_t avdtp_stream_endpoints;
72 static uint8_t avdtp_stream_endpoints_id_counter = 0;
73 
74 static bool avdtp_l2cap_registered;
75 
76 static btstack_linked_list_t avdtp_connections;
77 static uint8_t avdtp_transaction_id_counter = 0;
78 
79 static int avdtp_record_id;
80 static uint8_t avdtp_attribute_value[45];
81 static const unsigned int avdtp_attribute_value_buffer_size = sizeof(avdtp_attribute_value);
82 
83 static uint16_t avdtp_cid_counter = 0;
84 
85 static void avdtp_handle_sdp_client_query_result(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
86 
87 btstack_packet_handler_t
88 avdtp_packet_handler_for_stream_endpoint(const avdtp_stream_endpoint_t *stream_endpoint) {
89     return (stream_endpoint->sep.type == AVDTP_SOURCE) ? avdtp_source_callback : avdtp_sink_callback;
90 }
91 
92 void avdtp_emit_sink_and_source(uint8_t * packet, uint16_t size){
93     if (avdtp_source_callback != NULL){
94         (*avdtp_source_callback)(HCI_EVENT_PACKET, 0, packet, size);
95     }
96     if (avdtp_sink_callback != NULL){
97         (*avdtp_sink_callback)(HCI_EVENT_PACKET, 0, packet, size);
98     }
99 }
100 
101 void avdtp_emit_source(uint8_t * packet, uint16_t size){
102     if (avdtp_source_callback != NULL){
103         (*avdtp_source_callback)(HCI_EVENT_PACKET, 0, packet, size);
104     }
105 }
106 
107 btstack_linked_list_t * avdtp_get_stream_endpoints(void){
108     return &avdtp_stream_endpoints;
109 }
110 
111 btstack_linked_list_t * avdtp_get_connections(void){
112     return &avdtp_connections;
113 }
114 
115 avdtp_connection_t * avdtp_get_connection_for_bd_addr(bd_addr_t addr){
116     btstack_linked_list_iterator_t it;
117     btstack_linked_list_iterator_init(&it, &avdtp_connections);
118     while (btstack_linked_list_iterator_has_next(&it)){
119         avdtp_connection_t * connection = (avdtp_connection_t *)btstack_linked_list_iterator_next(&it);
120         if (memcmp(addr, connection->remote_addr, 6) != 0) continue;
121         return connection;
122     }
123     return NULL;
124 }
125 
126  avdtp_connection_t * avdtp_get_connection_for_avdtp_cid(uint16_t avdtp_cid){
127     btstack_linked_list_iterator_t it;
128     btstack_linked_list_iterator_init(&it, &avdtp_connections);
129     while (btstack_linked_list_iterator_has_next(&it)){
130         avdtp_connection_t * connection = (avdtp_connection_t *)btstack_linked_list_iterator_next(&it);
131         if (connection->avdtp_cid != avdtp_cid) continue;
132         return connection;
133     }
134     return NULL;
135 }
136 
137 
138 avdtp_stream_endpoint_t * avdtp_get_stream_endpoint_for_seid(uint16_t seid){
139     btstack_linked_list_iterator_t it;
140     btstack_linked_list_iterator_init(&it, avdtp_get_stream_endpoints());
141     while (btstack_linked_list_iterator_has_next(&it)){
142         avdtp_stream_endpoint_t * stream_endpoint = (avdtp_stream_endpoint_t *)btstack_linked_list_iterator_next(&it);
143         if (stream_endpoint->sep.seid == seid){
144             return stream_endpoint;
145         }
146     }
147     return NULL;
148 }
149 
150 avdtp_stream_endpoint_t * avdtp_get_source_stream_endpoint_for_media_codec_and_type(avdtp_media_codec_type_t codec_type, avdtp_sep_type_t sep_type){
151     btstack_linked_list_iterator_t it;
152     btstack_linked_list_iterator_init(&it, avdtp_get_stream_endpoints());
153     while (btstack_linked_list_iterator_has_next(&it)){
154         avdtp_stream_endpoint_t * stream_endpoint = (avdtp_stream_endpoint_t *)btstack_linked_list_iterator_next(&it);
155         if (stream_endpoint->sep.type != sep_type) continue;
156         if (stream_endpoint->sep.media_type != AVDTP_AUDIO) continue;
157         if (stream_endpoint->sep.capabilities.media_codec.media_codec_type != codec_type) continue;
158         if (stream_endpoint->sep.in_use) continue;
159         return stream_endpoint;
160     }
161     return NULL;
162 }
163 
164 avdtp_stream_endpoint_t * avdtp_get_source_stream_endpoint_for_media_codec(avdtp_media_codec_type_t codec_type){
165     return avdtp_get_source_stream_endpoint_for_media_codec_and_type(codec_type, AVDTP_SOURCE);
166 }
167 
168 
169 avdtp_stream_endpoint_t * avdtp_get_source_stream_endpoint_for_media_codec_other(uint32_t vendor_id, uint16_t codec_id){
170     btstack_linked_list_iterator_t it;
171     btstack_linked_list_iterator_init(&it, avdtp_get_stream_endpoints());
172     while (btstack_linked_list_iterator_has_next(&it)){
173         avdtp_stream_endpoint_t * stream_endpoint = (avdtp_stream_endpoint_t *)btstack_linked_list_iterator_next(&it);
174         if (stream_endpoint->sep.type != AVDTP_SOURCE) continue;
175         if (stream_endpoint->sep.media_type != AVDTP_AUDIO) continue;
176         if (stream_endpoint->sep.in_use) continue;
177         if (stream_endpoint->sep.capabilities.media_codec.media_codec_type != AVDTP_CODEC_NON_A2DP) continue;
178         if (stream_endpoint->sep.capabilities.media_codec.media_codec_information_len < 6) continue;
179         if (little_endian_read_32(stream_endpoint->sep.capabilities.media_codec.media_codec_information, 0) != vendor_id) continue;
180         if (little_endian_read_16(stream_endpoint->sep.capabilities.media_codec.media_codec_information, 4) != codec_id) continue;
181         return stream_endpoint;
182     }
183     return NULL;
184 }
185 
186 
187 avdtp_connection_t * avdtp_get_connection_for_l2cap_signaling_cid(uint16_t l2cap_cid){
188     btstack_linked_list_iterator_t it;
189     btstack_linked_list_iterator_init(&it, &avdtp_connections);
190     while (btstack_linked_list_iterator_has_next(&it)){
191         avdtp_connection_t * connection = (avdtp_connection_t *)btstack_linked_list_iterator_next(&it);
192         if (connection->l2cap_signaling_cid != l2cap_cid) continue;
193         return connection;
194     }
195     return NULL;
196 }
197 
198 static avdtp_stream_endpoint_t * avdtp_get_stream_endpoint_for_l2cap_cid(uint16_t l2cap_cid){
199     btstack_linked_list_iterator_t it;
200     btstack_linked_list_iterator_init(&it, avdtp_get_stream_endpoints());
201     while (btstack_linked_list_iterator_has_next(&it)){
202         avdtp_stream_endpoint_t * stream_endpoint = (avdtp_stream_endpoint_t *)btstack_linked_list_iterator_next(&it);
203         if (stream_endpoint->l2cap_media_cid == l2cap_cid){
204             return stream_endpoint;
205         }
206         if (stream_endpoint->l2cap_reporting_cid == l2cap_cid){
207             return stream_endpoint;
208         }
209         if (stream_endpoint->l2cap_recovery_cid == l2cap_cid){
210             return stream_endpoint;
211         }
212     }
213     return NULL;
214 }
215 
216 static avdtp_stream_endpoint_t * avdtp_get_stream_endpoint_for_signaling_cid(uint16_t l2cap_cid){
217     btstack_linked_list_iterator_t it;
218     btstack_linked_list_iterator_init(&it, avdtp_get_stream_endpoints());
219     while (btstack_linked_list_iterator_has_next(&it)){
220         avdtp_stream_endpoint_t * stream_endpoint = (avdtp_stream_endpoint_t *)btstack_linked_list_iterator_next(&it);
221         if (stream_endpoint->connection){
222             if (stream_endpoint->connection->l2cap_signaling_cid == l2cap_cid){
223                 return stream_endpoint;
224             }
225         }
226     }
227     return NULL;
228 }
229 
230 uint8_t avdtp_get_next_transaction_label(void){
231     avdtp_transaction_id_counter++;
232     if (avdtp_transaction_id_counter == 16){
233         avdtp_transaction_id_counter = 1;
234     }
235     return avdtp_transaction_id_counter;
236 }
237 
238 static avdtp_connection_t * avdtp_create_connection(bd_addr_t remote_addr, uint16_t cid){
239     avdtp_connection_t * connection = btstack_memory_avdtp_connection_get();
240     if (!connection){
241         log_error("Not enough memory to create connection");
242         return NULL;
243     }
244     connection->state = AVDTP_SIGNALING_CONNECTION_IDLE;
245     connection->initiator_transaction_label = avdtp_get_next_transaction_label();
246     connection->configuration_state = AVDTP_CONFIGURATION_STATE_IDLE;
247     connection->a2dp_source_config_process.discover_seps = false;
248     connection->avdtp_cid = cid;
249     (void)memcpy(connection->remote_addr, remote_addr, 6);
250 
251     btstack_linked_list_add_tail(&avdtp_connections, (btstack_linked_item_t *) connection);
252     return connection;
253 }
254 
255 static uint16_t avdtp_get_next_cid(void){
256     if (avdtp_cid_counter == 0xffff) {
257         avdtp_cid_counter = 1;
258     } else {
259         avdtp_cid_counter++;
260     }
261     return avdtp_cid_counter;
262 }
263 
264 // Stream Endpoint Identifier are 6-bit
265 static uint8_t avdtp_get_next_local_seid(void){
266     if (avdtp_stream_endpoints_id_counter >= 0x3f) {
267         avdtp_stream_endpoints_id_counter = 1;
268     } else {
269         avdtp_stream_endpoints_id_counter++;
270     }
271     return avdtp_stream_endpoints_id_counter;
272 }
273 
274 static void avdtp_handle_start_sdp_client_query(void * context){
275     UNUSED(context);
276 
277     uint16_t uuid;
278     btstack_linked_list_iterator_t it;
279     btstack_linked_list_iterator_init(&it, &avdtp_connections);
280     while (btstack_linked_list_iterator_has_next(&it)){
281         avdtp_connection_t * connection = (avdtp_connection_t *)btstack_linked_list_iterator_next(&it);
282 
283         switch (connection->state){
284             case AVDTP_SIGNALING_W2_SEND_SDP_QUERY_FOR_REMOTE_SOURCE:
285                 uuid = BLUETOOTH_SERVICE_CLASS_AUDIO_SOURCE;
286                 connection->state = AVDTP_SIGNALING_W4_SDP_QUERY_FOR_REMOTE_SOURCE_COMPLETE;
287                 break;
288             case AVDTP_SIGNALING_W2_SEND_SDP_QUERY_FOR_REMOTE_SINK:
289                 uuid = BLUETOOTH_SERVICE_CLASS_AUDIO_SINK;
290                 connection->state = AVDTP_SIGNALING_W4_SDP_QUERY_FOR_REMOTE_SINK_COMPLETE;
291                 break;
292             case AVDTP_SIGNALING_CONNECTION_OPENED:
293                 switch (connection->initiator_connection_state ){
294                     case AVDTP_SIGNALING_CONNECTION_INITIATOR_W2_SEND_SDP_QUERY_THEN_GET_ALL_CAPABILITIES_FROM_REMOTE_SOURCE:
295                         uuid = BLUETOOTH_SERVICE_CLASS_AUDIO_SOURCE;
296                         connection->initiator_connection_state = AVDTP_SIGNALING_CONNECTION_INITIATOR_W4_SDP_QUERY_COMPLETE_THEN_GET_ALL_CAPABILITIES;
297                         break;
298                     case AVDTP_SIGNALING_CONNECTION_INITIATOR_W2_SEND_SDP_QUERY_THEN_GET_ALL_CAPABILITIES_FROM_REMOTE_SINK:
299                         uuid = BLUETOOTH_SERVICE_CLASS_AUDIO_SINK;
300                         connection->initiator_connection_state = AVDTP_SIGNALING_CONNECTION_INITIATOR_W4_SDP_QUERY_COMPLETE_THEN_GET_ALL_CAPABILITIES;
301                         break;
302                     default:
303                         continue;
304                 }
305                 break;
306             default:
307                 continue;
308         }
309         avdtp_sdp_query_context_avdtp_cid = connection->avdtp_cid;
310         avdtp_record_id = -1;
311         sdp_client_query_uuid16(&avdtp_handle_sdp_client_query_result, (uint8_t *) connection->remote_addr, uuid);
312         return;
313     }
314 }
315 
316 uint8_t avdtp_connect(bd_addr_t remote, avdtp_role_t role, uint16_t * avdtp_cid){
317     avdtp_connection_t * connection = avdtp_get_connection_for_bd_addr(remote);
318     if (connection){
319         // allow to call avdtp_connect after signaling connection was triggered remotely
320         // @note this also allows to call avdtp_connect again before SLC is complete
321         if (connection->state < AVDTP_SIGNALING_CONNECTION_OPENED){
322             return ERROR_CODE_SUCCESS;
323         } else {
324             return ERROR_CODE_COMMAND_DISALLOWED;
325         }
326     }
327 
328     uint16_t cid = avdtp_get_next_cid();
329     if (avdtp_cid != NULL) {
330         *avdtp_cid = cid;
331     }
332 
333     connection = avdtp_create_connection(remote, cid);
334     if (!connection) return BTSTACK_MEMORY_ALLOC_FAILED;
335 
336     connection->avdtp_cid = cid;
337 
338     connection->avdtp_l2cap_psm = 0;
339     connection->avdtp_version  = 0;
340     connection->sink_supported = false;
341     connection->source_supported = false;
342 
343     switch (role){
344         case AVDTP_ROLE_SOURCE:
345             connection->state = AVDTP_SIGNALING_W2_SEND_SDP_QUERY_FOR_REMOTE_SINK;
346             break;
347         case AVDTP_ROLE_SINK:
348             connection->state = AVDTP_SIGNALING_W2_SEND_SDP_QUERY_FOR_REMOTE_SOURCE;
349             break;
350         default:
351             btstack_assert(false);
352             return ERROR_CODE_COMMAND_DISALLOWED;
353     }
354 
355     avdtp_handle_sdp_client_query_request.callback = &avdtp_handle_start_sdp_client_query;
356     // ignore ERROR_CODE_COMMAND_DISALLOWED because in that case, we already have requested an SDP callback
357     (void) sdp_client_register_query_callback(&avdtp_handle_sdp_client_query_request);
358     return ERROR_CODE_SUCCESS;
359 }
360 
361 
362 void avdtp_register_sink_packet_handler(btstack_packet_handler_t callback){
363     btstack_assert(callback != NULL);
364     avdtp_sink_callback = callback;
365 }
366 
367 void avdtp_register_source_packet_handler(btstack_packet_handler_t callback){
368     btstack_assert(callback != NULL);
369     avdtp_source_callback = callback;
370 }
371 
372 void avdtp_register_media_transport_category(avdtp_stream_endpoint_t * stream_endpoint){
373     if (!stream_endpoint){
374         log_error("Stream endpoint with given seid is not registered.");
375         return;
376     }
377     uint16_t bitmap = store_bit16(stream_endpoint->sep.registered_service_categories, AVDTP_MEDIA_TRANSPORT, 1);
378     stream_endpoint->sep.registered_service_categories = bitmap;
379 }
380 
381 void avdtp_register_reporting_category(avdtp_stream_endpoint_t * stream_endpoint){
382     if (!stream_endpoint){
383         log_error("Stream endpoint with given seid is not registered.");
384         return;
385     }
386     uint16_t bitmap = store_bit16(stream_endpoint->sep.registered_service_categories, AVDTP_REPORTING, 1);
387     stream_endpoint->sep.registered_service_categories = bitmap;
388 }
389 
390 void avdtp_register_delay_reporting_category(avdtp_stream_endpoint_t * stream_endpoint){
391     if (!stream_endpoint){
392         log_error("Stream endpoint with given seid is not registered.");
393         return;
394     }
395     uint16_t bitmap = store_bit16(stream_endpoint->sep.registered_service_categories, AVDTP_DELAY_REPORTING, 1);
396     stream_endpoint->sep.registered_service_categories = bitmap;
397 }
398 
399 void avdtp_register_recovery_category(avdtp_stream_endpoint_t * stream_endpoint, uint8_t maximum_recovery_window_size, uint8_t maximum_number_media_packets){
400     if (!stream_endpoint){
401         log_error("Stream endpoint with given seid is not registered.");
402         return;
403     }
404     uint16_t bitmap = store_bit16(stream_endpoint->sep.registered_service_categories, AVDTP_RECOVERY, 1);
405     stream_endpoint->sep.registered_service_categories = bitmap;
406     stream_endpoint->sep.capabilities.recovery.recovery_type = 0x01; // 0x01 = RFC2733
407     stream_endpoint->sep.capabilities.recovery.maximum_recovery_window_size = maximum_recovery_window_size;
408     stream_endpoint->sep.capabilities.recovery.maximum_number_media_packets = maximum_number_media_packets;
409 }
410 
411 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){
412     if (!stream_endpoint){
413         log_error("Stream endpoint with given seid is not registered.");
414         return;
415     }
416     uint16_t bitmap = store_bit16(stream_endpoint->sep.registered_service_categories, AVDTP_CONTENT_PROTECTION, 1);
417     stream_endpoint->sep.registered_service_categories = bitmap;
418     stream_endpoint->sep.capabilities.content_protection.cp_type = cp_type;
419     (void)memcpy(stream_endpoint->sep.capabilities.content_protection.cp_type_value,
420                  cp_type_value,
421                  btstack_min(cp_type_value_len, AVDTP_MAX_CONTENT_PROTECTION_TYPE_VALUE_LEN));
422     stream_endpoint->sep.capabilities.content_protection.cp_type_value_len = btstack_min(cp_type_value_len, AVDTP_MAX_CONTENT_PROTECTION_TYPE_VALUE_LEN);
423 }
424 
425 void avdtp_register_header_compression_category(avdtp_stream_endpoint_t * stream_endpoint, uint8_t back_ch, uint8_t media, uint8_t recovery){
426     if (!stream_endpoint){
427         log_error("Stream endpoint with given seid is not registered.");
428         return;
429     }
430     uint16_t bitmap = store_bit16(stream_endpoint->sep.registered_service_categories, AVDTP_HEADER_COMPRESSION, 1);
431     stream_endpoint->sep.registered_service_categories = bitmap;
432     stream_endpoint->sep.capabilities.header_compression.back_ch = back_ch;
433     stream_endpoint->sep.capabilities.header_compression.media = media;
434     stream_endpoint->sep.capabilities.header_compression.recovery = recovery;
435 }
436 
437 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, const uint8_t *media_codec_info, uint16_t media_codec_info_len){
438     if (!stream_endpoint){
439         log_error("Stream endpoint with given seid is not registered.");
440         return;
441     }
442     uint16_t bitmap = store_bit16(stream_endpoint->sep.registered_service_categories, AVDTP_MEDIA_CODEC, 1);
443     stream_endpoint->sep.registered_service_categories = bitmap;
444     stream_endpoint->sep.capabilities.media_codec.media_type = media_type;
445     stream_endpoint->sep.capabilities.media_codec.media_codec_type = media_codec_type;
446     // @todo should be stored in struct as const
447     stream_endpoint->sep.capabilities.media_codec.media_codec_information = (uint8_t*) media_codec_info;
448     stream_endpoint->sep.capabilities.media_codec.media_codec_information_len = media_codec_info_len;
449 }
450 
451 void avdtp_register_multiplexing_category(avdtp_stream_endpoint_t * stream_endpoint, uint8_t fragmentation){
452     if (!stream_endpoint){
453         log_error("Stream endpoint with given seid is not registered.");
454         return;
455     }
456     uint16_t bitmap = store_bit16(stream_endpoint->sep.registered_service_categories, AVDTP_MULTIPLEXING, 1);
457     stream_endpoint->sep.registered_service_categories = bitmap;
458     stream_endpoint->sep.capabilities.multiplexing_mode.fragmentation = fragmentation;
459 }
460 
461 void avdtp_register_media_handler(void (*callback)(uint8_t local_seid, uint8_t *packet, uint16_t size)){
462     avdtp_sink_handle_media_data = callback;
463 }
464 
465 void avdtp_sink_register_media_config_validator(uint8_t (*callback)(const avdtp_stream_endpoint_t * stream_endpoint, const uint8_t * event, uint16_t size)){
466     avdtp_sink_media_config_validator = callback;
467 }
468 
469 void avdtp_source_register_media_config_validator(uint8_t (*callback)(const avdtp_stream_endpoint_t * stream_endpoint, const uint8_t * event, uint16_t size)){
470     avdtp_source_media_config_validator = callback;
471 }
472 
473 uint8_t avdtp_validate_media_configuration(const avdtp_stream_endpoint_t *stream_endpoint, uint16_t avdtp_cid,
474                                            uint8_t reconfigure, const adtvp_media_codec_capabilities_t *media_codec) {
475     uint8_t (*callback)(const avdtp_stream_endpoint_t * stream_endpoint, const uint8_t * event, uint16_t size);
476     if (stream_endpoint->sep.type == AVDTP_SOURCE){
477         callback = avdtp_source_media_config_validator;
478     } else {
479         callback = avdtp_sink_media_config_validator;
480     }
481     if (callback == NULL) {
482         // config valid
483         return 0;
484     }
485     uint8_t event[AVDTP_MEDIA_CONFIG_OTHER_EVENT_LEN];
486     uint16_t size = avdtp_setup_media_codec_config_event(event, sizeof(event), stream_endpoint, avdtp_cid, reconfigure, media_codec);
487     return (*callback)(stream_endpoint, event, size);
488 }
489 
490 /* START: tracking can send now requests per l2cap cid */
491 static void avdtp_handle_can_send_now(uint16_t l2cap_cid) {
492 
493 	log_debug("avdtp_packet_handler, L2CAP_EVENT_CAN_SEND_NOW l2cap_cid 0x%02x", l2cap_cid);
494 
495 	// get signaling connection for l2cap cid
496 	avdtp_connection_t * connection = avdtp_get_connection_for_l2cap_signaling_cid(l2cap_cid);
497 
498 	if (connection != NULL) {
499 		if (connection->wait_to_send_acceptor) {
500 			log_debug("call avdtp_acceptor_stream_config_subsm_run %p", connection);
501 			connection->wait_to_send_acceptor = false;
502 			avdtp_acceptor_stream_config_subsm_run(connection);
503 		} else if (connection->wait_to_send_initiator) {
504 			log_debug("call avdtp_initiator_stream_config_subsm_handle_can_send_now_signaling %p", connection);
505 			connection->wait_to_send_initiator = false;
506 			avdtp_initiator_stream_config_subsm_handle_can_send_now_signaling(connection);
507 		}
508 		bool more_to_send = connection->wait_to_send_acceptor || connection->wait_to_send_initiator;
509 		if (more_to_send){
510 			l2cap_request_can_send_now_event(l2cap_cid);
511 		}
512 		return;
513 	}
514 
515 	// get stream endpoint connection for l2cap cid
516 	avdtp_stream_endpoint_t * stream_endpoint = avdtp_get_stream_endpoint_for_l2cap_cid(l2cap_cid);
517 	if (stream_endpoint != NULL) {
518 		log_debug("call avdtp_initiator_stream_config_subsm_handle_can_send_now_stream_endpoint %p", stream_endpoint);
519 		if (stream_endpoint->request_can_send_now) {
520 			stream_endpoint->request_can_send_now = false;
521 			avdtp_initiator_stream_config_subsm_handle_can_send_now_stream_endpoint(stream_endpoint);
522 		}
523 		if (stream_endpoint->request_can_send_now){
524 			l2cap_request_can_send_now_event(l2cap_cid);
525 		}
526 	}
527 }
528 /* END: tracking can send now requests per l2cap cid */
529 
530 
531 avdtp_stream_endpoint_t * avdtp_create_stream_endpoint(avdtp_sep_type_t sep_type, avdtp_media_type_t media_type){
532     avdtp_stream_endpoint_t * stream_endpoint = btstack_memory_avdtp_stream_endpoint_get();
533     if (!stream_endpoint){
534         log_error("Not enough memory to create stream endpoint");
535         return NULL;
536     }
537     stream_endpoint->sep.seid = avdtp_get_next_local_seid();
538     stream_endpoint->sep.media_type = media_type;
539     stream_endpoint->sep.type = sep_type;
540     btstack_linked_list_add(avdtp_get_stream_endpoints(), (btstack_linked_item_t *) stream_endpoint);
541     return stream_endpoint;
542 }
543 
544 void avdtp_finalize_stream_endpoint(avdtp_stream_endpoint_t * stream_endpoint){
545     btstack_linked_list_remove(avdtp_get_stream_endpoints(), (btstack_linked_item_t* ) stream_endpoint);
546     btstack_memory_avdtp_stream_endpoint_free(stream_endpoint);
547 }
548 
549 static void
550 handle_l2cap_data_packet_for_signaling_connection(avdtp_connection_t *connection, uint8_t *packet, uint16_t size) {
551     if (size < 2) return;
552 
553     uint16_t offset;
554     avdtp_message_type_t message_type = avdtp_get_signaling_message_type(packet);
555     switch (message_type){
556         case AVDTP_CMD_MSG:
557             offset = avdtp_read_signaling_header(&connection->acceptor_signaling_packet, packet, size);
558             if (offset > 0){
559                 avdtp_acceptor_stream_config_subsm(connection, packet, size, offset);
560             }
561             break;
562         default:
563                 offset = avdtp_read_signaling_header(&connection->initiator_signaling_packet, packet, size);
564             if (offset > 0) {
565                 avdtp_initiator_stream_config_subsm(connection, packet, size, offset);
566             }
567             break;
568     }
569 }
570 
571 static void avdtp_handle_sdp_client_query_attribute_value(avdtp_connection_t * connection, uint8_t *packet){
572     des_iterator_t des_list_it;
573     des_iterator_t prot_it;
574 
575     // Handle new SDP record
576     if (sdp_event_query_attribute_byte_get_record_id(packet) != avdtp_record_id) {
577         avdtp_record_id = sdp_event_query_attribute_byte_get_record_id(packet);
578         // log_info("SDP Record: Nr: %d", record_id);
579     }
580 
581     if (sdp_event_query_attribute_byte_get_attribute_length(packet) <= avdtp_attribute_value_buffer_size) {
582         avdtp_attribute_value[sdp_event_query_attribute_byte_get_data_offset(packet)] = sdp_event_query_attribute_byte_get_data(packet);
583 
584         if ((uint16_t)(sdp_event_query_attribute_byte_get_data_offset(packet)+1) == sdp_event_query_attribute_byte_get_attribute_length(packet)) {
585 
586             switch(sdp_event_query_attribute_byte_get_attribute_id(packet)) {
587 
588                 case BLUETOOTH_ATTRIBUTE_SERVICE_CLASS_ID_LIST:
589                     if (de_get_element_type(avdtp_attribute_value) != DE_DES) break;
590                     for (des_iterator_init(&des_list_it, avdtp_attribute_value); des_iterator_has_more(&des_list_it); des_iterator_next(&des_list_it)) {
591                         uint8_t * element = des_iterator_get_element(&des_list_it);
592                         if (de_get_element_type(element) != DE_UUID) continue;
593                         uint32_t uuid = de_get_uuid32(element);
594                         switch (uuid){
595                             case BLUETOOTH_SERVICE_CLASS_AUDIO_SOURCE:
596                                 connection->source_supported = true;
597                                 log_info("source_supported");
598                                 break;
599                             case BLUETOOTH_SERVICE_CLASS_AUDIO_SINK:
600                                 connection->sink_supported = true;
601                                 log_info("sink_supported");
602                                 break;
603                             default:
604                                 break;
605                         }
606                     }
607                     break;
608 
609                 case BLUETOOTH_ATTRIBUTE_PROTOCOL_DESCRIPTOR_LIST:
610                     // log_info("SDP Attribute: 0x%04x", sdp_event_query_attribute_byte_get_attribute_id(packet));
611                     for (des_iterator_init(&des_list_it, avdtp_attribute_value); des_iterator_has_more(&des_list_it); des_iterator_next(&des_list_it)) {
612                         uint8_t       *des_element;
613                         uint8_t       *element;
614                         uint32_t       uuid;
615 
616                         if (des_iterator_get_type(&des_list_it) != DE_DES) continue;
617 
618                         des_element = des_iterator_get_element(&des_list_it);
619                         des_iterator_init(&prot_it, des_element);
620                         element = des_iterator_get_element(&prot_it);
621 
622                         if (de_get_element_type(element) != DE_UUID) continue;
623 
624                         uuid = de_get_uuid32(element);
625                         des_iterator_next(&prot_it);
626                         // we assume that the even if there are both roles supported, remote device uses the same psm and avdtp version for both
627                         switch (uuid){
628                             case BLUETOOTH_PROTOCOL_L2CAP:
629                                 if (!des_iterator_has_more(&prot_it)) continue;
630                                 de_element_get_uint16(des_iterator_get_element(&prot_it), &connection->avdtp_l2cap_psm);
631                                 break;
632                             case BLUETOOTH_PROTOCOL_AVDTP:
633                                 if (!des_iterator_has_more(&prot_it)) continue;
634                                 de_element_get_uint16(des_iterator_get_element(&prot_it), &connection->avdtp_version);
635                                 log_info("avdtp version 0x%02x", connection->avdtp_version);
636                                 break;
637                             default:
638                                 break;
639                         }
640                     }
641                     break;
642 
643                 default:
644                     break;
645             }
646         }
647     } else {
648         log_error("SDP attribute value buffer size exceeded: available %d, required %d", avdtp_attribute_value_buffer_size, sdp_event_query_attribute_byte_get_attribute_length(packet));
649     }
650 
651 }
652 
653 static void avdtp_finalize_connection(avdtp_connection_t * connection){
654     btstack_run_loop_remove_timer(&connection->retry_timer);
655     btstack_linked_list_remove(&avdtp_connections, (btstack_linked_item_t*) connection);
656     btstack_memory_avdtp_connection_free(connection);
657 }
658 
659 static void avdtp_handle_sdp_query_failed(avdtp_connection_t * connection, uint8_t status){
660     switch (connection->state){
661         case AVDTP_SIGNALING_W4_SDP_QUERY_FOR_REMOTE_SINK_COMPLETE:
662         case AVDTP_SIGNALING_W4_SDP_QUERY_FOR_REMOTE_SOURCE_COMPLETE:
663             avdtp_signaling_emit_connection_established(connection->avdtp_cid, connection->remote_addr, connection->con_handle, status);
664             break;
665 
666         case AVDTP_SIGNALING_CONNECTION_OPENED:
667             // SDP query failed: try query that must be supported
668             connection->initiator_connection_state = AVDTP_SIGNALING_CONNECTION_INITIATOR_W2_GET_CAPABILITIES;
669 			avdtp_request_can_send_now_initiator(connection);
670             return;
671 
672         default:
673             btstack_assert(false);
674             break;
675     }
676     avdtp_finalize_connection(connection);
677     avdtp_sdp_query_context_avdtp_cid = 0;
678     log_info("SDP query failed with status 0x%02x.", status);
679 }
680 
681 static void avdtp_handle_sdp_query_succeeded(avdtp_connection_t * connection){
682     log_info("avdtp_handle_sdp_query_succeeded: state %d", connection->state);
683 
684     switch (connection->state){
685         case AVDTP_SIGNALING_CONNECTION_OPENED:
686             if (connection->avdtp_version < 0x0103){
687                 connection->initiator_connection_state = AVDTP_SIGNALING_CONNECTION_INITIATOR_W2_GET_CAPABILITIES;
688             } else {
689                 connection->initiator_connection_state = AVDTP_SIGNALING_CONNECTION_INITIATOR_W2_GET_ALL_CAPABILITIES;
690             }
691 			avdtp_request_can_send_now_initiator(connection);
692             break;
693         default:
694             connection->state = AVDTP_SIGNALING_CONNECTION_W4_L2CAP_CONNECTED;
695             l2cap_create_channel(avdtp_packet_handler, connection->remote_addr, connection->avdtp_l2cap_psm, AVDTP_L2CAP_MTU, NULL);
696             break;
697     }
698 }
699 
700 static void avdtp_handle_sdp_client_query_result(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
701     UNUSED(packet_type);
702     UNUSED(channel);
703     UNUSED(size);
704 
705     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_sdp_query_context_avdtp_cid);
706     if (!connection) {
707         log_error("SDP query, connection with 0x%02x cid not found", avdtp_sdp_query_context_avdtp_cid);
708         return;
709     }
710 
711     uint8_t status = ERROR_CODE_SUCCESS;
712     switch (connection->state){
713         case AVDTP_SIGNALING_W4_SDP_QUERY_FOR_REMOTE_SINK_COMPLETE:
714             switch (hci_event_packet_get_type(packet)){
715                 case SDP_EVENT_QUERY_ATTRIBUTE_VALUE:
716                     avdtp_handle_sdp_client_query_attribute_value(connection, packet);
717                     return;
718                 case SDP_EVENT_QUERY_COMPLETE:
719                     status = sdp_event_query_complete_get_status(packet);
720                     if (status != ERROR_CODE_SUCCESS) break;
721                     if (!connection->sink_supported || (connection->avdtp_l2cap_psm == 0)) {
722                         status = SDP_SERVICE_NOT_FOUND;
723                         break;
724                     }
725                     break;
726                 default:
727                     btstack_assert(false);
728                     return;
729             }
730             break;
731         case AVDTP_SIGNALING_W4_SDP_QUERY_FOR_REMOTE_SOURCE_COMPLETE:
732             switch (hci_event_packet_get_type(packet)){
733                 case SDP_EVENT_QUERY_ATTRIBUTE_VALUE:
734                     avdtp_handle_sdp_client_query_attribute_value(connection, packet);
735                     return;
736                 case SDP_EVENT_QUERY_COMPLETE:
737                     status = sdp_event_query_complete_get_status(packet);
738                     if (status != ERROR_CODE_SUCCESS) break;
739                     if (!connection->source_supported || (connection->avdtp_l2cap_psm == 0)) {
740                         status = SDP_SERVICE_NOT_FOUND;
741                         break;
742                     }
743                     break;
744                 default:
745                     btstack_assert(false);
746                     return;
747             }
748             break;
749 
750         case AVDTP_SIGNALING_CONNECTION_OPENED:
751             switch (hci_event_packet_get_type(packet)){
752                 case SDP_EVENT_QUERY_ATTRIBUTE_VALUE:
753                     avdtp_handle_sdp_client_query_attribute_value(connection, packet);
754                     return;
755                 case SDP_EVENT_QUERY_COMPLETE:
756                     // without suitable SDP Record, avdtp version v0.0 is assumed
757                     status = sdp_event_query_complete_get_status(packet);
758                     break;
759                 default:
760                     btstack_assert(false);
761                     return;
762             }
763             break;
764 
765         default:
766             // bail out, we must have had an incoming connection in the meantime; just trigger next sdp query on complete
767             if (hci_event_packet_get_type(packet) == SDP_EVENT_QUERY_COMPLETE){
768                 (void) sdp_client_register_query_callback(&avdtp_handle_sdp_client_query_request);
769             }
770             return;
771     }
772 
773     if (status == ERROR_CODE_SUCCESS){
774         avdtp_handle_sdp_query_succeeded(connection);
775     } else {
776         avdtp_handle_sdp_query_failed(connection, status);
777     }
778 
779     // register the SDP Query request to check if there is another connection waiting for the query
780     // ignore ERROR_CODE_COMMAND_DISALLOWED because in that case, we already have requested an SDP callback
781     (void) sdp_client_register_query_callback(&avdtp_handle_sdp_client_query_request);
782 }
783 
784 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){
785     if (connection == NULL){
786         uint16_t cid = avdtp_get_next_cid();
787         connection = avdtp_create_connection(event_addr, cid);
788     }
789 
790     if (connection) {
791         connection->state = AVDTP_SIGNALING_CONNECTION_W4_L2CAP_CONNECTED;
792         connection->l2cap_signaling_cid = local_cid;
793         connection->con_handle = con_handle;
794         btstack_run_loop_remove_timer(&connection->retry_timer);
795     }
796     return connection;
797 }
798 
799 static void avdtp_retry_timer_timeout_handler(btstack_timer_source_t * timer){
800     uint16_t avdtp_cid = (uint16_t)(uintptr_t) btstack_run_loop_get_timer_context(timer);
801 
802     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
803     if (connection == NULL) return;
804 
805     if (connection->state == AVDTP_SIGNALING_CONNECTION_W2_L2CAP_RETRY){
806         connection->state = AVDTP_SIGNALING_CONNECTION_W4_L2CAP_CONNECTED;
807         l2cap_create_channel(&avdtp_packet_handler, connection->remote_addr, connection->avdtp_l2cap_psm, AVDTP_L2CAP_MTU, NULL);
808     }
809 }
810 
811 static void avdtp_retry_timer_start(avdtp_connection_t * connection){
812     btstack_run_loop_set_timer_handler(&connection->retry_timer, avdtp_retry_timer_timeout_handler);
813     btstack_run_loop_set_timer_context(&connection->retry_timer, (void *)(uintptr_t)connection->avdtp_cid);
814 
815     // add some jitter/randomness to reconnect delay
816     uint32_t timeout = 100 + (btstack_run_loop_get_time_ms() & 0x7F);
817     btstack_run_loop_set_timer(&connection->retry_timer, timeout);
818     btstack_run_loop_add_timer(&connection->retry_timer);
819 }
820 
821 static void avdtp_handle_close_media_channel(avdtp_stream_endpoint_t * stream_endpoint){
822     avdtp_connection_t * connection = stream_endpoint->connection;
823     btstack_assert(connection != NULL);
824     avdtp_streaming_emit_connection_released(stream_endpoint, connection->avdtp_cid, avdtp_local_seid(stream_endpoint));
825     avdtp_reset_stream_endpoint(stream_endpoint);
826     connection->configuration_state = AVDTP_CONFIGURATION_STATE_IDLE;
827 }
828 
829 static void avdtp_handle_close_recovery_channel(avdtp_stream_endpoint_t * stream_endpoint){
830     log_info("L2CAP_EVENT_CHANNEL_CLOSED recovery cid 0x%0x", stream_endpoint->l2cap_recovery_cid);
831     stream_endpoint->l2cap_recovery_cid = 0;
832 }
833 
834 static void avdtp_handle_close_reporting_channel(avdtp_stream_endpoint_t * stream_endpoint){
835     log_info("L2CAP_EVENT_CHANNEL_CLOSED reporting cid 0x%0x", stream_endpoint->l2cap_reporting_cid);
836     stream_endpoint->l2cap_reporting_cid = 0;
837 }
838 
839 
840 void avdtp_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
841     bd_addr_t event_addr;
842     uint16_t psm;
843     uint16_t local_cid;
844     uint8_t  status;
845     uint16_t l2cap_mtu;
846     hci_con_handle_t con_handle;
847 
848     bool accept_streaming_connection;
849     bool outoing_signaling_active;
850     bool decline_connection;
851 
852     avdtp_stream_endpoint_t * stream_endpoint = NULL;
853     avdtp_connection_t * connection = NULL;
854 
855     switch (packet_type) {
856         case L2CAP_DATA_PACKET:
857             connection = avdtp_get_connection_for_l2cap_signaling_cid(channel);
858             if (connection){
859                 handle_l2cap_data_packet_for_signaling_connection(connection, packet, size);
860                 break;
861             }
862 
863             stream_endpoint = avdtp_get_stream_endpoint_for_l2cap_cid(channel);
864             if (!stream_endpoint){
865                 if (!connection) break;
866                 handle_l2cap_data_packet_for_signaling_connection(connection, packet, size);
867                 break;
868             }
869 
870             if (stream_endpoint->connection){
871                 if (channel == stream_endpoint->connection->l2cap_signaling_cid){
872                     handle_l2cap_data_packet_for_signaling_connection(stream_endpoint->connection, packet, size);
873                     break;
874                 }
875             }
876 
877             if (channel == stream_endpoint->l2cap_media_cid){
878                 btstack_assert(avdtp_sink_handle_media_data);
879                 (*avdtp_sink_handle_media_data)(avdtp_local_seid(stream_endpoint), packet, size);
880                 break;
881             }
882 
883             if (channel == stream_endpoint->l2cap_reporting_cid){
884                 log_info("L2CAP_DATA_PACKET for reporting: NOT IMPLEMENTED");
885             } else if (channel == stream_endpoint->l2cap_recovery_cid){
886                 log_info("L2CAP_DATA_PACKET for recovery: NOT IMPLEMENTED");
887             } else {
888                 log_error("avdtp packet handler L2CAP_DATA_PACKET: local cid 0x%02x not found", channel);
889             }
890             break;
891 
892         case HCI_EVENT_PACKET:
893             switch (hci_event_packet_get_type(packet)) {
894 
895                 case L2CAP_EVENT_INCOMING_CONNECTION:
896                     l2cap_event_incoming_connection_get_address(packet, event_addr);
897                     local_cid = l2cap_event_incoming_connection_get_local_cid(packet);
898                     con_handle = l2cap_event_incoming_connection_get_handle(packet);
899                     outoing_signaling_active = false;
900                     accept_streaming_connection = false;
901 
902                     connection = avdtp_get_connection_for_bd_addr(event_addr);
903                     if (connection != NULL){
904                         switch (connection->state){
905                             case AVDTP_SIGNALING_CONNECTION_W4_L2CAP_DISCONNECTED:
906                             case AVDTP_SIGNALING_CONNECTION_W4_L2CAP_CONNECTED:
907                                 outoing_signaling_active = true;
908                                 connection->incoming_declined = true;
909                                 break;
910                             case AVDTP_SIGNALING_CONNECTION_OPENED:
911                                 outoing_signaling_active = true;
912                                 accept_streaming_connection = true;
913                                 break;
914                             default:
915                                 break;
916                         }
917                     }
918                     log_info("incoming: %s, outoing_signaling_active %d, accept_streaming_connection %d",
919                         bd_addr_to_str(event_addr), outoing_signaling_active, accept_streaming_connection);
920 
921                     decline_connection = outoing_signaling_active && !accept_streaming_connection;
922                     if (outoing_signaling_active == false){
923                         connection = avdtp_handle_incoming_connection(connection, event_addr, con_handle, local_cid);
924                         if (connection == NULL){
925                             decline_connection = true;
926                         }
927                     } else if (accept_streaming_connection){
928                         if ((connection == NULL) || (connection->configuration_state != AVDTP_CONFIGURATION_STATE_REMOTE_CONFIGURED)) {
929                             decline_connection = true;
930                         } else {
931                             // now, we're only dealing with media connections that are created by remote side - we're acceptor here
932                             stream_endpoint = avdtp_get_stream_endpoint_for_seid(connection->acceptor_local_seid);
933                             if ((stream_endpoint == NULL) || (stream_endpoint->l2cap_media_cid != 0) ) {
934                                 decline_connection = true;
935                             }
936                         }
937                     }
938 
939                     if (decline_connection){
940                         l2cap_decline_connection(local_cid);
941                     } else {
942                         l2cap_accept_connection(local_cid);
943                     }
944                     break;
945 
946                 case L2CAP_EVENT_CHANNEL_OPENED:
947 
948                     psm = l2cap_event_channel_opened_get_psm(packet);
949                     if (psm != BLUETOOTH_PSM_AVDTP){
950                         log_info("Unexpected PSM - Not implemented yet, avdtp sink: L2CAP_EVENT_CHANNEL_OPENED ");
951                         return;
952                     }
953 
954                     status = l2cap_event_channel_opened_get_status(packet);
955                     // inform about new l2cap connection
956                     l2cap_event_channel_opened_get_address(packet, event_addr);
957                     local_cid = l2cap_event_channel_opened_get_local_cid(packet);
958                     l2cap_mtu = l2cap_event_channel_opened_get_remote_mtu(packet);
959                     connection = avdtp_get_connection_for_bd_addr(event_addr);
960                     if (connection == NULL){
961                         log_info("L2CAP_EVENT_CHANNEL_OPENED: no connection found for %s", bd_addr_to_str(event_addr));
962                         break;
963                     }
964 
965                     con_handle = l2cap_event_channel_opened_get_handle(packet);
966 
967                     switch (connection->state){
968                         case AVDTP_SIGNALING_CONNECTION_W4_L2CAP_CONNECTED:
969                             switch (status){
970                                 case ERROR_CODE_SUCCESS:
971                                     connection->l2cap_signaling_cid = local_cid;
972                                     connection->incoming_declined = false;
973                                     connection->l2cap_mtu = l2cap_mtu;
974                                     connection->con_handle = con_handle;
975                                     connection->state = AVDTP_SIGNALING_CONNECTION_OPENED;
976                                     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);
977                                     avdtp_signaling_emit_connection_established(connection->avdtp_cid, event_addr, con_handle, status);
978                                     return;
979                                 case L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_RESOURCES:
980                                     if (connection->incoming_declined == true) {
981                                         log_info("Connection was declined, and the outgoing failed");
982                                         connection->state = AVDTP_SIGNALING_CONNECTION_W2_L2CAP_RETRY;
983                                         connection->incoming_declined = false;
984                                         avdtp_retry_timer_start(connection);
985                                         return;
986                                     }
987                                     break;
988                                 default:
989                                     log_info("Connection to %s failed. status code 0x%02x", bd_addr_to_str(event_addr), status);
990                                     break;
991                             }
992                             avdtp_signaling_emit_connection_established(connection->avdtp_cid, event_addr, con_handle, status);
993                             avdtp_finalize_connection(connection);
994                             break;
995 
996                         case AVDTP_SIGNALING_CONNECTION_OPENED:
997                             stream_endpoint = avdtp_get_stream_endpoint_for_signaling_cid(connection->l2cap_signaling_cid);
998                             if (!stream_endpoint){
999                                 log_info("L2CAP_EVENT_CHANNEL_OPENED: stream_endpoint not found for signaling cid 0x%02x", connection->l2cap_signaling_cid);
1000                                 return;
1001                             }
1002                             if (status != ERROR_CODE_SUCCESS){
1003                                 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));
1004                                 stream_endpoint->state = AVDTP_STREAM_ENDPOINT_IDLE;
1005                                 avdtp_streaming_emit_connection_established(stream_endpoint, status);
1006                                 break;
1007                             }
1008                             switch (stream_endpoint->state){
1009                                 case AVDTP_STREAM_ENDPOINT_W4_L2CAP_FOR_MEDIA_CONNECTED:
1010                                     stream_endpoint->state = AVDTP_STREAM_ENDPOINT_OPENED;
1011                                     stream_endpoint->l2cap_media_cid = l2cap_event_channel_opened_get_local_cid(packet);
1012                                     stream_endpoint->media_con_handle = l2cap_event_channel_opened_get_handle(packet);
1013 
1014                                     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));
1015                                     avdtp_streaming_emit_connection_established(stream_endpoint, ERROR_CODE_SUCCESS);
1016                                     break;
1017                                 default:
1018                                     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));
1019                                     avdtp_streaming_emit_connection_established(stream_endpoint, ERROR_CODE_COMMAND_DISALLOWED);
1020                                     break;
1021                             }
1022                             break;
1023 
1024                         default:
1025                             log_info("L2CAP connection to %s ignored: status code 0x%02x, connection state %d", bd_addr_to_str(event_addr), status, connection->state);
1026                             break;
1027                     }
1028                     break;
1029 
1030                 case L2CAP_EVENT_CHANNEL_CLOSED:
1031                     local_cid = l2cap_event_channel_closed_get_local_cid(packet);
1032                     stream_endpoint = avdtp_get_stream_endpoint_for_l2cap_cid(local_cid);
1033                     connection = avdtp_get_connection_for_l2cap_signaling_cid(local_cid);
1034 
1035                     log_info("Received L2CAP_EVENT_CHANNEL_CLOSED, cid 0x%2x, connection %p, stream_endpoint %p", local_cid, connection, stream_endpoint);
1036 
1037                     if (stream_endpoint){
1038                         if (stream_endpoint->l2cap_media_cid == local_cid){
1039                             avdtp_handle_close_media_channel(stream_endpoint);
1040                             break;
1041                         }
1042                         if (stream_endpoint->l2cap_recovery_cid == local_cid){
1043                             avdtp_handle_close_recovery_channel(stream_endpoint);
1044                             break;
1045                         }
1046                         if (stream_endpoint->l2cap_reporting_cid == local_cid){
1047                             avdtp_handle_close_reporting_channel(stream_endpoint);
1048                             break;
1049                         }
1050                     }
1051 
1052                     if (connection){
1053                         // closing signaling channel invalidates all other channels as well
1054                         btstack_linked_list_iterator_t it;
1055                         btstack_linked_list_iterator_init(&it, avdtp_get_stream_endpoints());
1056                         while (btstack_linked_list_iterator_has_next(&it)){
1057                             stream_endpoint = (avdtp_stream_endpoint_t *)btstack_linked_list_iterator_next(&it);
1058                             if (stream_endpoint->connection == connection){
1059                                 avdtp_handle_close_recovery_channel(stream_endpoint);
1060                                 avdtp_handle_close_reporting_channel(stream_endpoint);
1061                                 avdtp_handle_close_media_channel(stream_endpoint);
1062                                 avdtp_reset_stream_endpoint(stream_endpoint);
1063                             }
1064                         }
1065                         avdtp_signaling_emit_connection_released(connection->avdtp_cid);
1066                         avdtp_finalize_connection(connection);
1067                         break;
1068                     }
1069                     break;
1070 
1071                 case L2CAP_EVENT_CAN_SEND_NOW:
1072                     log_debug("avdtp_packet_handler, L2CAP_EVENT_CAN_SEND_NOW l2cap_cid 0x%02x", channel);
1073 					avdtp_handle_can_send_now(channel);
1074                     break;
1075                 default:
1076                     log_info("Unknown HCI event type %02x", hci_event_packet_get_type(packet));
1077                     break;
1078             }
1079             break;
1080 
1081         default:
1082             // other packet type
1083             break;
1084     }
1085 }
1086 
1087 static void avdtp_disconenct_streamendpoints(const avdtp_connection_t *connection) {
1088     btstack_linked_list_iterator_t it;
1089     btstack_linked_list_iterator_init(&it, avdtp_get_stream_endpoints());
1090     while (btstack_linked_list_iterator_has_next(&it)){
1091         avdtp_stream_endpoint_t * stream_endpoint = (avdtp_stream_endpoint_t *)btstack_linked_list_iterator_next(&it);
1092         if (stream_endpoint->connection != connection) continue;
1093 
1094         switch (stream_endpoint->state){
1095             case AVDTP_STREAM_ENDPOINT_OPENED:
1096             case AVDTP_STREAM_ENDPOINT_STREAMING:
1097                 stream_endpoint->state = AVDTP_STREAM_ENDPOINT_W4_L2CAP_FOR_MEDIA_DISCONNECTED;
1098                 l2cap_disconnect(stream_endpoint->l2cap_media_cid);
1099                 break;
1100             default:
1101                 break;
1102         }
1103     }
1104 }
1105 
1106 uint8_t avdtp_disconnect(uint16_t avdtp_cid){
1107     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
1108     if (!connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1109 
1110     switch (connection->state){
1111         case AVDTP_SIGNALING_CONNECTION_OPENED:
1112             avdtp_disconenct_streamendpoints(connection);
1113             connection->state = AVDTP_SIGNALING_CONNECTION_W4_L2CAP_DISCONNECTED;
1114             l2cap_disconnect(connection->l2cap_signaling_cid);
1115             break;
1116         case AVDTP_SIGNALING_CONNECTION_W4_L2CAP_DISCONNECTED:
1117             // stream endpoints closed, wait for disconnected
1118             break;
1119         default:
1120             // connection has not been reported as established yet, report open failed
1121             avdtp_signaling_emit_connection_established(connection->avdtp_cid, connection->remote_addr,
1122                                                         connection->con_handle, ERROR_CODE_UNSPECIFIED_ERROR);
1123             avdtp_finalize_connection(connection);
1124             break;
1125     }
1126     return ERROR_CODE_SUCCESS;
1127 }
1128 
1129 
1130 #ifdef ENABLE_AVDTP_ACCEPTOR_EXPLICIT_START_STREAM_CONFIRMATION
1131 static uint8_t avdtp_handle_explicit_start_stream_confirmation(uint16_t avdtp_cid, uint8_t local_seid, bool accept_stream_requested){
1132     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
1133     if (!connection){
1134         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1135     }
1136 
1137     if (connection->state != AVDTP_SIGNALING_CONNECTION_OPENED) {
1138         log_error("avdtp_media_connect: wrong connection state %d", connection->state);
1139         return ERROR_CODE_COMMAND_DISALLOWED;
1140     }
1141 
1142     avdtp_stream_endpoint_t * stream_endpoint = avdtp_get_stream_endpoint_for_seid(local_seid);
1143     if (!stream_endpoint) {
1144         log_error("avdtp_media_connect: no stream_endpoint with seid %d found", local_seid);
1145         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1146     }
1147 
1148     if (stream_endpoint->acceptor_config_state != AVDTP_ACCEPTOR_W4_USER_CONFIRM_START_STREAM){
1149         return ERROR_CODE_COMMAND_DISALLOWED;
1150     }
1151 
1152     if (accept_stream_requested){
1153         stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_ACCEPT_START_STREAM;
1154     } else {
1155         stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_START_STREAM;
1156     }
1157     avdtp_request_can_send_now_acceptor(connection);
1158     return ERROR_CODE_SUCCESS;
1159 }
1160 
1161 uint8_t avdtp_start_stream_accept(uint16_t avdtp_cid, uint8_t local_seid){
1162     return avdtp_handle_explicit_start_stream_confirmation(avdtp_cid, local_seid, true);
1163 }
1164 
1165 uint8_t avdtp_start_stream_reject(uint16_t avdtp_cid, uint8_t local_seid){
1166     return avdtp_handle_explicit_start_stream_confirmation(avdtp_cid, local_seid, false);
1167 }
1168 #endif
1169 
1170 uint8_t avdtp_open_stream(uint16_t avdtp_cid, uint8_t local_seid, uint8_t remote_seid){
1171     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
1172     if (!connection){
1173         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1174     }
1175 
1176     if (connection->state != AVDTP_SIGNALING_CONNECTION_OPENED) {
1177         log_error("avdtp_media_connect: wrong connection state %d", connection->state);
1178         return ERROR_CODE_COMMAND_DISALLOWED;
1179     }
1180 
1181     avdtp_stream_endpoint_t * stream_endpoint = avdtp_get_stream_endpoint_for_seid(local_seid);
1182     if (!stream_endpoint) {
1183         log_error("avdtp_media_connect: no stream_endpoint with seid %d found", local_seid);
1184         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1185     }
1186 
1187     if (stream_endpoint->remote_sep.seid != remote_seid){
1188         log_error("avdtp_media_connect: no remote sep with seid %d registered with the stream endpoint", remote_seid);
1189         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1190     }
1191 
1192     if (stream_endpoint->state < AVDTP_STREAM_ENDPOINT_CONFIGURED) return ERROR_CODE_COMMAND_DISALLOWED;
1193 
1194     connection->initiator_transaction_label= avdtp_get_next_transaction_label();
1195     connection->initiator_remote_seid = remote_seid;
1196     connection->initiator_local_seid = local_seid;
1197     stream_endpoint->initiator_config_state = AVDTP_INITIATOR_W2_OPEN_STREAM;
1198     stream_endpoint->state = AVDTP_STREAM_ENDPOINT_W2_REQUEST_OPEN_STREAM;
1199 	avdtp_request_can_send_now_initiator(connection);
1200     return ERROR_CODE_SUCCESS;
1201 }
1202 
1203 uint8_t avdtp_start_stream(uint16_t avdtp_cid, uint8_t local_seid){
1204     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
1205     if (!connection){
1206         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1207     }
1208 
1209     avdtp_stream_endpoint_t * stream_endpoint = avdtp_get_stream_endpoint_for_seid(local_seid);
1210     if (!stream_endpoint) {
1211         log_error("avdtp_start_stream: no stream_endpoint with seid %d found", local_seid);
1212         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1213     }
1214 
1215     if (stream_endpoint->l2cap_media_cid == 0){
1216         log_error("avdtp_start_stream: no media connection for stream_endpoint with seid %d found", local_seid);
1217         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1218     }
1219 
1220     if (!is_avdtp_remote_seid_registered(stream_endpoint)){
1221         log_error("avdtp_media_connect: no remote sep registered with the stream endpoint");
1222         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1223     }
1224 
1225     if (!is_avdtp_remote_seid_registered(stream_endpoint) || stream_endpoint->start_stream == 1){
1226         return ERROR_CODE_COMMAND_DISALLOWED;
1227     }
1228 
1229     if (stream_endpoint->start_stream == 1) {
1230         return ERROR_CODE_COMMAND_DISALLOWED;
1231     }
1232 
1233     stream_endpoint->start_stream = 1;
1234     connection->initiator_local_seid = local_seid;
1235     connection->initiator_remote_seid = stream_endpoint->remote_sep.seid;
1236 	avdtp_request_can_send_now_initiator(connection);
1237     return ERROR_CODE_SUCCESS;
1238 }
1239 
1240 uint8_t avdtp_stop_stream(uint16_t avdtp_cid, uint8_t local_seid){
1241     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
1242     if (!connection){
1243         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1244     }
1245 
1246     avdtp_stream_endpoint_t * stream_endpoint = avdtp_get_stream_endpoint_for_seid(local_seid);
1247     if (!stream_endpoint) {
1248         log_error("avdtp_stop_stream: no stream_endpoint with seid %d found", local_seid);
1249         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1250     }
1251 
1252     if (stream_endpoint->l2cap_media_cid == 0){
1253         log_error("avdtp_stop_stream: no media connection for stream_endpoint with seid %d found", local_seid);
1254         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1255     }
1256 
1257     if (!is_avdtp_remote_seid_registered(stream_endpoint) || stream_endpoint->close_stream){
1258         return ERROR_CODE_COMMAND_DISALLOWED;
1259     }
1260 
1261     if (stream_endpoint->close_stream == 1) {
1262         return ERROR_CODE_COMMAND_DISALLOWED;
1263     }
1264 
1265     stream_endpoint->close_stream = 1;
1266     connection->initiator_local_seid = local_seid;
1267     connection->initiator_remote_seid = stream_endpoint->remote_sep.seid;
1268 	avdtp_request_can_send_now_initiator(connection);
1269     return ERROR_CODE_SUCCESS;
1270 }
1271 
1272 uint8_t avdtp_abort_stream(uint16_t avdtp_cid, uint8_t local_seid){
1273     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
1274     if (!connection){
1275         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1276     }
1277 
1278     avdtp_stream_endpoint_t * stream_endpoint = avdtp_get_stream_endpoint_for_seid(local_seid);
1279     if (!stream_endpoint) {
1280         log_error("avdtp_abort_stream: no stream_endpoint with seid %d found", local_seid);
1281         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1282     }
1283 
1284     if (stream_endpoint->l2cap_media_cid == 0){
1285         log_error("avdtp_abort_stream: no media connection for stream_endpoint with seid %d found", local_seid);
1286         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1287     }
1288 
1289     if (!is_avdtp_remote_seid_registered(stream_endpoint) || stream_endpoint->abort_stream){
1290         return ERROR_CODE_COMMAND_DISALLOWED;
1291     }
1292 
1293     if (stream_endpoint->abort_stream == 1) {
1294         return ERROR_CODE_COMMAND_DISALLOWED;
1295     }
1296 
1297     stream_endpoint->abort_stream = 1;
1298     connection->initiator_local_seid = local_seid;
1299     connection->initiator_remote_seid = stream_endpoint->remote_sep.seid;
1300 	avdtp_request_can_send_now_initiator(connection);
1301     return ERROR_CODE_SUCCESS;
1302 }
1303 
1304 uint8_t avdtp_suspend_stream(uint16_t avdtp_cid, uint8_t local_seid){
1305     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
1306     if (!connection){
1307         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1308     }
1309     avdtp_stream_endpoint_t * stream_endpoint = avdtp_get_stream_endpoint_for_seid(local_seid);
1310     if (!stream_endpoint) {
1311         log_error("avdtp_suspend_stream: no stream_endpoint with seid %d found", local_seid);
1312         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1313     }
1314 
1315     if (stream_endpoint->l2cap_media_cid == 0){
1316         log_error("avdtp_suspend_stream: no media connection for stream_endpoint with seid %d found", local_seid);
1317         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1318     }
1319 
1320     if (!is_avdtp_remote_seid_registered(stream_endpoint)){
1321         return ERROR_CODE_COMMAND_DISALLOWED;
1322     }
1323 
1324     if (stream_endpoint->state != AVDTP_STREAM_ENDPOINT_STREAMING){
1325         return ERROR_CODE_COMMAND_DISALLOWED;
1326     }
1327 
1328     if (stream_endpoint->suspend_stream == 1) {
1329         return ERROR_CODE_COMMAND_DISALLOWED;
1330     }
1331 
1332     stream_endpoint->suspend_stream = 1;
1333     connection->initiator_local_seid = local_seid;
1334     connection->initiator_remote_seid = stream_endpoint->remote_sep.seid;
1335 	avdtp_request_can_send_now_initiator(connection);
1336     return ERROR_CODE_SUCCESS;
1337 }
1338 
1339 uint8_t avdtp_discover_stream_endpoints(uint16_t avdtp_cid){
1340     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
1341     if (!connection){
1342         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1343     }
1344     if ((connection->state != AVDTP_SIGNALING_CONNECTION_OPENED) ||
1345         (connection->initiator_connection_state != AVDTP_SIGNALING_CONNECTION_INITIATOR_IDLE)) {
1346         return ERROR_CODE_COMMAND_DISALLOWED;
1347     }
1348 
1349     connection->initiator_transaction_label= avdtp_get_next_transaction_label();
1350     connection->initiator_connection_state = AVDTP_SIGNALING_CONNECTION_INITIATOR_W2_DISCOVER_SEPS;
1351     return avdtp_request_can_send_now_initiator(connection);
1352 }
1353 
1354 
1355 uint8_t avdtp_get_capabilities(uint16_t avdtp_cid, uint8_t remote_seid){
1356     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
1357     if (!connection){
1358         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1359     }
1360     if ((connection->state != AVDTP_SIGNALING_CONNECTION_OPENED) ||
1361         (connection->initiator_connection_state != AVDTP_SIGNALING_CONNECTION_INITIATOR_IDLE)) {
1362         return ERROR_CODE_COMMAND_DISALLOWED;
1363     }
1364 
1365     connection->initiator_transaction_label= avdtp_get_next_transaction_label();
1366     connection->initiator_connection_state = AVDTP_SIGNALING_CONNECTION_INITIATOR_W2_GET_CAPABILITIES;
1367     connection->initiator_remote_seid = remote_seid;
1368     return avdtp_request_can_send_now_initiator(connection);
1369 }
1370 
1371 
1372 uint8_t avdtp_get_all_capabilities(uint16_t avdtp_cid, uint8_t remote_seid, avdtp_role_t role) {
1373     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
1374     if (!connection){
1375         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1376     }
1377     if ((connection->state != AVDTP_SIGNALING_CONNECTION_OPENED) ||
1378         (connection->initiator_connection_state != AVDTP_SIGNALING_CONNECTION_INITIATOR_IDLE)) {
1379         return ERROR_CODE_COMMAND_DISALLOWED;
1380     }
1381 
1382     connection->initiator_transaction_label= avdtp_get_next_transaction_label();
1383     connection->initiator_remote_seid = remote_seid;
1384 
1385     if (connection->avdtp_version == 0){
1386         switch(role){
1387             case AVDTP_ROLE_SINK:
1388                 connection->initiator_connection_state = AVDTP_SIGNALING_CONNECTION_INITIATOR_W2_SEND_SDP_QUERY_THEN_GET_ALL_CAPABILITIES_FROM_REMOTE_SOURCE;
1389                 break;
1390             case AVDTP_ROLE_SOURCE:
1391                 connection->initiator_connection_state = AVDTP_SIGNALING_CONNECTION_INITIATOR_W2_SEND_SDP_QUERY_THEN_GET_ALL_CAPABILITIES_FROM_REMOTE_SINK;
1392                 break;
1393             default:
1394                 btstack_unreachable();
1395                 break;
1396         }
1397         avdtp_handle_sdp_client_query_request.callback = &avdtp_handle_start_sdp_client_query;
1398         // ignore ERROR_CODE_COMMAND_DISALLOWED because in that case, we already have requested an SDP callback
1399         (void) sdp_client_register_query_callback(&avdtp_handle_sdp_client_query_request);
1400         return ERROR_CODE_SUCCESS;
1401     } else {
1402         // AVDTP version lower then 1.3 supports only get capabilities command
1403         if (connection->avdtp_version < 0x103){
1404             connection->initiator_connection_state = AVDTP_SIGNALING_CONNECTION_INITIATOR_W2_GET_CAPABILITIES;
1405         } else {
1406             connection->initiator_connection_state = AVDTP_SIGNALING_CONNECTION_INITIATOR_W2_GET_ALL_CAPABILITIES;
1407         }
1408         return avdtp_request_can_send_now_initiator(connection);
1409     }
1410 }
1411 
1412 uint8_t avdtp_get_configuration(uint16_t avdtp_cid, uint8_t remote_seid){
1413     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
1414     if (!connection){
1415         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1416     }
1417     if ((connection->state != AVDTP_SIGNALING_CONNECTION_OPENED) ||
1418         (connection->initiator_connection_state != AVDTP_SIGNALING_CONNECTION_INITIATOR_IDLE)) {
1419         return ERROR_CODE_COMMAND_DISALLOWED;
1420     }
1421 
1422     connection->initiator_transaction_label= avdtp_get_next_transaction_label();
1423     connection->initiator_connection_state = AVDTP_SIGNALING_CONNECTION_INITIATOR_W2_GET_CONFIGURATION;
1424     connection->initiator_remote_seid = remote_seid;
1425     return avdtp_request_can_send_now_initiator(connection);
1426 }
1427 
1428 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){
1429     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
1430     if (!connection){
1431         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1432     }
1433     if ((connection->state != AVDTP_SIGNALING_CONNECTION_OPENED) ||
1434         (connection->initiator_connection_state != AVDTP_SIGNALING_CONNECTION_INITIATOR_IDLE)) {
1435         log_error("connection in wrong state, %d, initiator state %d", connection->state, connection->initiator_connection_state);
1436         return ERROR_CODE_COMMAND_DISALLOWED;
1437     }
1438     if (connection->configuration_state != AVDTP_CONFIGURATION_STATE_IDLE){
1439         log_info("configuration already started, config state %u", connection->configuration_state);
1440         return ERROR_CODE_COMMAND_DISALLOWED;
1441     }
1442 
1443     avdtp_stream_endpoint_t * stream_endpoint = avdtp_get_stream_endpoint_for_seid(local_seid);
1444     if (!stream_endpoint) {
1445         log_error("No initiator stream endpoint for seid %d", local_seid);
1446         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1447     }
1448     if (stream_endpoint->state >= AVDTP_STREAM_ENDPOINT_CONFIGURED){
1449         log_error("Stream endpoint seid %d in wrong state %d", local_seid, stream_endpoint->state);
1450         return ERROR_CODE_COMMAND_DISALLOWED;
1451     }
1452 
1453     connection->active_stream_endpoint = (void*) stream_endpoint;
1454     connection->configuration_state = AVDTP_CONFIGURATION_STATE_LOCAL_INITIATED;
1455 
1456     connection->initiator_transaction_label= avdtp_get_next_transaction_label();
1457     connection->initiator_remote_seid = remote_seid;
1458     connection->initiator_local_seid = local_seid;
1459     stream_endpoint->remote_configuration_bitmap = configured_services_bitmap;
1460     stream_endpoint->remote_configuration = configuration;
1461     stream_endpoint->initiator_config_state = AVDTP_INITIATOR_W2_SET_CONFIGURATION;
1462 
1463 	log_debug("SE %p, initiator_config_state: 0x%02x", stream_endpoint, stream_endpoint->initiator_config_state);
1464 
1465     return avdtp_request_can_send_now_initiator(connection);
1466 }
1467 
1468 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){
1469     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
1470     if (!connection){
1471         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1472     }
1473     //TODO: if opened only app capabilities, enable reconfigure for not opened
1474     if ((connection->state != AVDTP_SIGNALING_CONNECTION_OPENED) ||
1475         (connection->initiator_connection_state != AVDTP_SIGNALING_CONNECTION_INITIATOR_IDLE)) {
1476         return ERROR_CODE_COMMAND_DISALLOWED;
1477     }
1478 
1479     avdtp_stream_endpoint_t * stream_endpoint = avdtp_get_stream_endpoint_for_seid(local_seid);
1480     if (!stream_endpoint) {
1481         log_error("avdtp_reconfigure: no initiator stream endpoint for seid %d", local_seid);
1482         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1483     }
1484 
1485     if (!is_avdtp_remote_seid_registered(stream_endpoint)){
1486         log_error("avdtp_reconfigure: no associated remote sep");
1487         return ERROR_CODE_COMMAND_DISALLOWED;
1488     }
1489 
1490     connection->initiator_transaction_label= avdtp_get_next_transaction_label();
1491     connection->initiator_remote_seid = remote_seid;
1492     connection->initiator_local_seid = local_seid;
1493     stream_endpoint->remote_configuration_bitmap = configured_services_bitmap;
1494     stream_endpoint->remote_configuration = configuration;
1495     stream_endpoint->initiator_config_state = AVDTP_INITIATOR_W2_RECONFIGURE_STREAM_WITH_SEID;
1496     return avdtp_request_can_send_now_initiator(connection);
1497 }
1498 
1499 void    avdtp_set_preferred_sampling_frequency(avdtp_stream_endpoint_t * stream_endpoint, uint32_t sampling_frequency){
1500     stream_endpoint->preferred_sampling_frequency = sampling_frequency;
1501 }
1502 
1503 void    avdtp_set_preferred_channel_mode(avdtp_stream_endpoint_t * stream_endpoint, uint8_t channel_mode){
1504     stream_endpoint->preferred_channel_mode = channel_mode;
1505 }
1506 
1507 
1508 avdtp_channel_mode_t avdtp_choose_sbc_channel_mode(avdtp_stream_endpoint_t * stream_endpoint, uint8_t remote_channel_mode_bitmap){
1509     uint8_t * media_codec = stream_endpoint->sep.capabilities.media_codec.media_codec_information;
1510     uint8_t channel_mode_bitmap = (media_codec[0] & 0x0F) & remote_channel_mode_bitmap;
1511 
1512     // use preferred channel mode if possible
1513     if (stream_endpoint->preferred_channel_mode == AVDTP_SBC_JOINT_STEREO){
1514         return AVDTP_CHANNEL_MODE_JOINT_STEREO;
1515     }
1516     if (stream_endpoint->preferred_channel_mode == AVDTP_SBC_STEREO){
1517         return AVDTP_CHANNEL_MODE_STEREO;
1518     }
1519     if (stream_endpoint->preferred_channel_mode == AVDTP_SBC_DUAL_CHANNEL){
1520         return AVDTP_CHANNEL_MODE_DUAL_CHANNEL;
1521     }
1522     if (stream_endpoint->preferred_channel_mode == AVDTP_SBC_MONO){
1523         return AVDTP_CHANNEL_MODE_MONO;
1524     }
1525 
1526 
1527     if (channel_mode_bitmap & AVDTP_SBC_JOINT_STEREO){
1528         return AVDTP_CHANNEL_MODE_JOINT_STEREO;
1529     } else if (channel_mode_bitmap & AVDTP_SBC_STEREO){
1530         return AVDTP_CHANNEL_MODE_STEREO;
1531     } else if (channel_mode_bitmap & AVDTP_SBC_DUAL_CHANNEL){
1532         return AVDTP_CHANNEL_MODE_DUAL_CHANNEL;
1533     } else if (channel_mode_bitmap & AVDTP_SBC_MONO){
1534         return AVDTP_CHANNEL_MODE_MONO;
1535     }
1536     return AVDTP_CHANNEL_MODE_JOINT_STEREO;
1537 }
1538 
1539 avdtp_sbc_allocation_method_t avdtp_choose_sbc_allocation_method(avdtp_stream_endpoint_t * stream_endpoint, uint8_t remote_allocation_method_bitmap){
1540     uint8_t * media_codec = stream_endpoint->sep.capabilities.media_codec.media_codec_information;
1541     uint8_t allocation_method_bitmap = (media_codec[1] & 0x03) & remote_allocation_method_bitmap;
1542 
1543     avdtp_sbc_allocation_method_t allocation_method = AVDTP_SBC_ALLOCATION_METHOD_LOUDNESS;
1544     if (allocation_method_bitmap & AVDTP_SBC_ALLOCATION_METHOD_LOUDNESS){
1545         allocation_method = AVDTP_SBC_ALLOCATION_METHOD_LOUDNESS;
1546     } else if (allocation_method_bitmap & AVDTP_SBC_ALLOCATION_METHOD_SNR){
1547         allocation_method = AVDTP_SBC_ALLOCATION_METHOD_SNR;
1548     }
1549     return allocation_method;
1550 }
1551 
1552 uint8_t avdtp_stream_endpoint_seid(avdtp_stream_endpoint_t * stream_endpoint){
1553     if (!stream_endpoint) return 0;
1554     return stream_endpoint->sep.seid;
1555 }
1556 uint8_t avdtp_choose_sbc_subbands(avdtp_stream_endpoint_t * stream_endpoint, uint8_t remote_subbands_bitmap){
1557     if (!stream_endpoint) return 0;
1558     uint8_t * media_codec = stream_endpoint->sep.capabilities.media_codec.media_codec_information;
1559     uint8_t subbands_bitmap = ((media_codec[1] >> 2) & 0x03) & remote_subbands_bitmap;
1560 
1561     uint8_t subbands = AVDTP_SBC_SUBBANDS_8;
1562     if (subbands_bitmap & AVDTP_SBC_SUBBANDS_8){
1563         subbands = AVDTP_SBC_SUBBANDS_8;
1564     } else if (subbands_bitmap & AVDTP_SBC_SUBBANDS_4){
1565         subbands = AVDTP_SBC_SUBBANDS_4;
1566     }
1567     return subbands;
1568 }
1569 
1570 uint8_t avdtp_choose_sbc_block_length(avdtp_stream_endpoint_t * stream_endpoint, uint8_t remote_block_length_bitmap){
1571     if (!stream_endpoint) return 0;
1572     uint8_t * media_codec = stream_endpoint->sep.capabilities.media_codec.media_codec_information;
1573     uint8_t block_length_bitmap = (media_codec[1] >> 4) & remote_block_length_bitmap;
1574 
1575     uint8_t block_length = AVDTP_SBC_BLOCK_LENGTH_16;
1576     if (block_length_bitmap & AVDTP_SBC_BLOCK_LENGTH_16){
1577         block_length = AVDTP_SBC_BLOCK_LENGTH_16;
1578     } else if (block_length_bitmap & AVDTP_SBC_BLOCK_LENGTH_12){
1579         block_length = AVDTP_SBC_BLOCK_LENGTH_12;
1580     } else if (block_length_bitmap & AVDTP_SBC_BLOCK_LENGTH_8){
1581         block_length = AVDTP_SBC_BLOCK_LENGTH_8;
1582     } else if (block_length_bitmap & AVDTP_SBC_BLOCK_LENGTH_4){
1583         block_length = AVDTP_SBC_BLOCK_LENGTH_4;
1584     }
1585     return block_length;
1586 }
1587 
1588 uint16_t avdtp_get_highest_sampling_frequency(uint8_t sampling_frequency_bitmap){
1589     if (sampling_frequency_bitmap & AVDTP_SBC_48000){
1590         return 48000;
1591     }
1592     if (sampling_frequency_bitmap & AVDTP_SBC_44100){
1593         return 44100;
1594     }
1595     if (sampling_frequency_bitmap & AVDTP_SBC_32000){
1596         return 32000;
1597     }
1598     if (sampling_frequency_bitmap & AVDTP_SBC_16000){
1599         return 16000;
1600     }
1601     return 0;
1602 }
1603 
1604 uint16_t avdtp_choose_sbc_sampling_frequency(avdtp_stream_endpoint_t * stream_endpoint, uint8_t remote_sampling_frequency_bitmap){
1605     if (!stream_endpoint) return 0;
1606     uint8_t * media_codec = stream_endpoint->sep.capabilities.media_codec.media_codec_information;
1607     uint8_t supported_sampling_frequency_bitmap = (media_codec[0] >> 4) & remote_sampling_frequency_bitmap;
1608 
1609     // use preferred sampling frequency if possible
1610     if ((stream_endpoint->preferred_sampling_frequency == 48000) && (supported_sampling_frequency_bitmap & AVDTP_SBC_48000)){
1611         return stream_endpoint->preferred_sampling_frequency;
1612     }
1613     if ((stream_endpoint->preferred_sampling_frequency == 44100) && (supported_sampling_frequency_bitmap & AVDTP_SBC_44100)){
1614         return stream_endpoint->preferred_sampling_frequency;
1615     }
1616     if ((stream_endpoint->preferred_sampling_frequency == 32000) && (supported_sampling_frequency_bitmap & AVDTP_SBC_32000)){
1617         return stream_endpoint->preferred_sampling_frequency;
1618     }
1619     if ((stream_endpoint->preferred_sampling_frequency == 16000) && (supported_sampling_frequency_bitmap & AVDTP_SBC_16000)){
1620         return stream_endpoint->preferred_sampling_frequency;
1621     }
1622 
1623     // otherwise, use highest available
1624     uint16_t sampling_frequency = avdtp_get_highest_sampling_frequency(supported_sampling_frequency_bitmap);
1625     if (sampling_frequency != 0){
1626         return sampling_frequency;
1627     } else {
1628         return 44100; // some default
1629     }
1630 }
1631 
1632 uint8_t avdtp_choose_sbc_max_bitpool_value(avdtp_stream_endpoint_t * stream_endpoint, uint8_t remote_max_bitpool_value){
1633     if (!stream_endpoint) return 0;
1634     uint8_t * media_codec = stream_endpoint->sep.capabilities.media_codec.media_codec_information;
1635     return btstack_min(media_codec[3], remote_max_bitpool_value);
1636 }
1637 
1638 uint8_t avdtp_choose_sbc_min_bitpool_value(avdtp_stream_endpoint_t * stream_endpoint, uint8_t remote_min_bitpool_value){
1639     if (!stream_endpoint) return 0;
1640     uint8_t * media_codec = stream_endpoint->sep.capabilities.media_codec.media_codec_information;
1641     return btstack_max(media_codec[2], remote_min_bitpool_value);
1642 }
1643 
1644 uint8_t is_avdtp_remote_seid_registered(avdtp_stream_endpoint_t * stream_endpoint){
1645     if (!stream_endpoint) return 0;
1646     if (stream_endpoint->remote_sep.seid == 0) return 0;
1647     if (stream_endpoint->remote_sep.seid > 0x3E) return 0;
1648     return 1;
1649 }
1650 
1651 void avdtp_init(void){
1652     if (!avdtp_l2cap_registered){
1653         avdtp_l2cap_registered = true;
1654         l2cap_register_service(&avdtp_packet_handler, BLUETOOTH_PSM_AVDTP, AVDTP_L2CAP_MTU, gap_get_security_level());
1655     }
1656 }
1657 
1658 void avdtp_deinit(void){
1659     avdtp_sink_handle_media_data = NULL;
1660     avdtp_sink_media_config_validator = NULL;
1661     avdtp_source_media_config_validator = NULL;
1662     avdtp_source_callback = NULL;
1663     avdtp_sink_callback = NULL;
1664 
1665     avdtp_sdp_query_context_avdtp_cid = 0;
1666 
1667     avdtp_stream_endpoints = NULL;
1668     avdtp_stream_endpoints_id_counter = 0;
1669 
1670     avdtp_l2cap_registered = false;
1671 
1672     avdtp_connections = NULL;
1673     avdtp_transaction_id_counter = 0;
1674 
1675     avdtp_record_id = 0;
1676     avdtp_cid_counter = 0;
1677 }
1678 
1679 #ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
1680 #define FUZZ_CID 0x44
1681 #define FUZZ_CON_HANDLE 0x0001
1682 static bd_addr_t remote_addr = { 0x33, 0x33, 0x33, 0x33, 0x33, 0x33 };
1683 void avdtp_init_fuzz(void){
1684     // setup avdtp connections for cid
1685     avdtp_connection_t * connection = avdtp_create_connection(remote_addr, FUZZ_CID);
1686     connection->state = AVDTP_SIGNALING_CONNECTION_OPENED;
1687     connection->l2cap_signaling_cid = FUZZ_CID;
1688     connection->con_handle = FUZZ_CON_HANDLE;
1689 }
1690 void avdtp_packet_handler_fuzz(uint8_t *packet, uint16_t size){
1691     avdtp_packet_handler(L2CAP_DATA_PACKET, FUZZ_CID, packet, size);
1692 }
1693 #endif