xref: /btstack/src/classic/avdtp_util.c (revision 9192020a6656c4bc46feb4a63ee628096661bb3b)
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_util.c"
39 
40 #include <stdint.h>
41 #include <string.h>
42 
43 #include "btstack.h"
44 #include "avdtp.h"
45 #include "avdtp_util.h"
46 
47 #define MAX_MEDIA_CODEC_INFORMATION_LENGTH 100
48 
49 static const char * avdtp_si_name[] = {
50     "ERROR",
51     "AVDTP_SI_DISCOVER",
52     "AVDTP_SI_GET_CAPABILITIES",
53     "AVDTP_SI_SET_CONFIGURATION",
54     "AVDTP_SI_GET_CONFIGURATION",
55     "AVDTP_SI_RECONFIGURE",
56     "AVDTP_SI_OPEN",
57     "AVDTP_SI_START",
58     "AVDTP_SI_CLOSE",
59     "AVDTP_SI_SUSPEND",
60     "AVDTP_SI_ABORT",
61     "AVDTP_SI_SECURITY_CONTROL",
62     "AVDTP_SI_GET_ALL_CAPABILITIES",
63     "AVDTP_SI_DELAY_REPORT"
64 };
65 const char * avdtp_si2str(uint16_t index){
66     if ((index <= 0) || (index >= sizeof(avdtp_si_name)/sizeof(avdtp_si_name[0]) )) return avdtp_si_name[0];
67     return avdtp_si_name[index];
68 }
69 
70 void avdtp_reset_stream_endpoint(avdtp_stream_endpoint_t * stream_endpoint){
71     stream_endpoint->media_con_handle = 0;
72     stream_endpoint->l2cap_media_cid = 0;
73     stream_endpoint->l2cap_reporting_cid = 0;
74     stream_endpoint->l2cap_recovery_cid = 0;
75 
76     stream_endpoint->connection = NULL;
77     stream_endpoint->state = AVDTP_STREAM_ENDPOINT_IDLE;
78     stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_STREAM_CONFIG_IDLE;
79     stream_endpoint->initiator_config_state = AVDTP_INITIATOR_STREAM_CONFIG_IDLE;
80 
81     stream_endpoint->sep.in_use = 0;
82     memset(&stream_endpoint->remote_sep, 0, sizeof(avdtp_sep_t));
83     // memset(&stream_endpoint->remote_capabilities, 0, sizeof(avdtp_capabilities_t));
84     // memset(&stream_endpoint->remote_configuration, 0, sizeof(avdtp_capabilities_t));
85 
86     stream_endpoint->remote_capabilities_bitmap = 0;
87     stream_endpoint->remote_configuration_bitmap = 0;
88 
89     stream_endpoint->media_disconnect = 0;
90     stream_endpoint->media_connect = 0;
91     stream_endpoint->start_stream = 0;
92     stream_endpoint->stop_stream = 0;
93     stream_endpoint->send_stream = 0;
94     stream_endpoint->abort_stream = 0;
95     stream_endpoint->suspend_stream = 0;
96     stream_endpoint->sequence_number = 0;
97 }
98 
99 avdtp_stream_endpoint_t * avdtp_get_stream_endpoint_for_seid(uint16_t seid, avdtp_context_t * context){
100     btstack_linked_list_iterator_t it;
101     btstack_linked_list_iterator_init(&it, &context->stream_endpoints);
102     while (btstack_linked_list_iterator_has_next(&it)){
103         avdtp_stream_endpoint_t * stream_endpoint = (avdtp_stream_endpoint_t *)btstack_linked_list_iterator_next(&it);
104         if (stream_endpoint->sep.seid == seid){
105             return stream_endpoint;
106         }
107     }
108     return NULL;
109 }
110 
111 avdtp_connection_t * avdtp_get_connection_for_bd_addr(bd_addr_t addr, avdtp_context_t * context){
112     btstack_linked_list_iterator_t it;
113     btstack_linked_list_iterator_init(&it, &context->connections);
114     while (btstack_linked_list_iterator_has_next(&it)){
115         avdtp_connection_t * connection = (avdtp_connection_t *)btstack_linked_list_iterator_next(&it);
116         if (memcmp(addr, connection->remote_addr, 6) != 0) continue;
117         return connection;
118     }
119     return NULL;
120 }
121 
122 avdtp_connection_t * avdtp_get_connection_for_avdtp_cid(uint16_t avdtp_cid, avdtp_context_t * context){
123     btstack_linked_list_iterator_t it;
124     btstack_linked_list_iterator_init(&it, &context->connections);
125     while (btstack_linked_list_iterator_has_next(&it)){
126         avdtp_connection_t * connection = (avdtp_connection_t *)btstack_linked_list_iterator_next(&it);
127         if (connection->avdtp_cid != avdtp_cid) continue;
128         return connection;
129     }
130     return NULL;
131 }
132 
133 avdtp_connection_t * avdtp_get_connection_for_l2cap_signaling_cid(uint16_t l2cap_cid, avdtp_context_t * context){
134     btstack_linked_list_iterator_t it;
135     btstack_linked_list_iterator_init(&it, &context->connections);
136     while (btstack_linked_list_iterator_has_next(&it)){
137         avdtp_connection_t * connection = (avdtp_connection_t *)btstack_linked_list_iterator_next(&it);
138         if (connection->l2cap_signaling_cid != l2cap_cid) continue;
139         return connection;
140     }
141     return NULL;
142 }
143 
144 avdtp_stream_endpoint_t * avdtp_get_stream_endpoint_for_l2cap_cid(uint16_t l2cap_cid, avdtp_context_t * context){
145     btstack_linked_list_iterator_t it;
146     btstack_linked_list_iterator_init(&it, &context->stream_endpoints);
147     while (btstack_linked_list_iterator_has_next(&it)){
148         avdtp_stream_endpoint_t * stream_endpoint = (avdtp_stream_endpoint_t *)btstack_linked_list_iterator_next(&it);
149         if (stream_endpoint->l2cap_media_cid == l2cap_cid){
150             return stream_endpoint;
151         }
152         if (stream_endpoint->l2cap_reporting_cid == l2cap_cid){
153             return stream_endpoint;
154         }
155         if (stream_endpoint->l2cap_recovery_cid == l2cap_cid){
156             return stream_endpoint;
157         }
158     }
159     return NULL;
160 }
161 
162 avdtp_stream_endpoint_t * avdtp_get_stream_endpoint_for_signaling_cid(uint16_t l2cap_cid, avdtp_context_t * context){
163     btstack_linked_list_iterator_t it;
164     btstack_linked_list_iterator_init(&it, &context->stream_endpoints);
165     while (btstack_linked_list_iterator_has_next(&it)){
166         avdtp_stream_endpoint_t * stream_endpoint = (avdtp_stream_endpoint_t *)btstack_linked_list_iterator_next(&it);
167         if (stream_endpoint->connection){
168             if (stream_endpoint->connection->l2cap_signaling_cid == l2cap_cid){
169                 return stream_endpoint;
170             }
171         }
172     }
173     return NULL;
174 }
175 
176 avdtp_stream_endpoint_t * avdtp_get_stream_endpoint_with_seid(uint8_t seid, avdtp_context_t * context){
177     btstack_linked_list_iterator_t it;
178     btstack_linked_list_iterator_init(&it, &context->stream_endpoints);
179     while (btstack_linked_list_iterator_has_next(&it)){
180         avdtp_stream_endpoint_t * stream_endpoint = (avdtp_stream_endpoint_t *)btstack_linked_list_iterator_next(&it);
181         if (stream_endpoint->sep.seid == seid){
182             return stream_endpoint;
183         }
184     }
185     return NULL;
186 }
187 
188 avdtp_stream_endpoint_t * avdtp_get_stream_endpoint_associated_with_acp_seid(uint16_t acp_seid, avdtp_context_t * context){
189     btstack_linked_list_iterator_t it;
190     btstack_linked_list_iterator_init(&it, &context->stream_endpoints);
191     while (btstack_linked_list_iterator_has_next(&it)){
192         avdtp_stream_endpoint_t * stream_endpoint = (avdtp_stream_endpoint_t *)btstack_linked_list_iterator_next(&it);
193         if (stream_endpoint->remote_sep.seid == acp_seid){
194             return stream_endpoint;
195         }
196     }
197     return NULL;
198 }
199 
200 int get_bit16(uint16_t bitmap, int position){
201     return (bitmap >> position) & 1;
202 }
203 
204 uint16_t store_bit16(uint16_t bitmap, int position, uint8_t value){
205     if (value){
206         bitmap |= 1 << position;
207     } else {
208         bitmap &= ~ (1 << position);
209     }
210     return bitmap;
211 }
212 
213 avdtp_message_type_t avdtp_get_signaling_packet_type(uint8_t * packet){
214     return (avdtp_message_type_t) (packet[0] & 0x03);
215 }
216 
217 int avdtp_read_signaling_header(avdtp_signaling_packet_t * signaling_header, uint8_t * packet, uint16_t size){
218     int pos = 0;
219     if (size < 2) return pos;
220     signaling_header->transaction_label = packet[pos] >> 4;
221     signaling_header->packet_type = (avdtp_packet_type_t)((packet[pos] >> 2) & 0x03);
222     signaling_header->message_type = (avdtp_message_type_t) (packet[pos] & 0x03);
223     pos++;
224     memset(signaling_header->command, 0, sizeof(signaling_header->command));
225     switch (signaling_header->packet_type){
226         case AVDTP_SINGLE_PACKET:
227             signaling_header->num_packets = 0;
228             signaling_header->offset = 0;
229             signaling_header->size = 0;
230             break;
231         case AVDTP_END_PACKET:
232             signaling_header->num_packets = 0;
233             break;
234         case AVDTP_START_PACKET:
235             signaling_header->num_packets = packet[pos++];
236             signaling_header->size = 0;
237             signaling_header->offset = 0;
238             break;
239         case AVDTP_CONTINUE_PACKET:
240             if (signaling_header->num_packets <= 0) {
241                 log_info("    ERROR: wrong num fragmented packets\n");
242                 break;
243             }
244             signaling_header->num_packets--;
245             break;
246     }
247     signaling_header->signal_identifier = (avdtp_signal_identifier_t)(packet[pos++] & 0x3f);
248     return pos;
249 }
250 
251 int avdtp_pack_service_capabilities(uint8_t * buffer, int size, avdtp_capabilities_t caps, avdtp_service_category_t category, uint8_t pack_all_capabilities){
252     UNUSED(size);
253 
254     int i;
255     // pos = 0 reserved for length
256     int pos = 1;
257     switch(category){
258         case AVDTP_MEDIA_TRANSPORT:
259         case AVDTP_REPORTING:
260             break;
261         case AVDTP_DELAY_REPORTING:
262             if (!pack_all_capabilities) break;
263             break;
264         case AVDTP_RECOVERY:
265             buffer[pos++] = caps.recovery.recovery_type; // 0x01=RFC2733
266             buffer[pos++] = caps.recovery.maximum_recovery_window_size;
267             buffer[pos++] = caps.recovery.maximum_number_media_packets;
268             break;
269         case AVDTP_CONTENT_PROTECTION:
270             buffer[pos++] = caps.content_protection.cp_type_value_len + 2;
271             big_endian_store_16(buffer, pos, caps.content_protection.cp_type);
272             pos += 2;
273             (void)memcpy(buffer + pos, caps.content_protection.cp_type_value,
274                          caps.content_protection.cp_type_value_len);
275             break;
276         case AVDTP_HEADER_COMPRESSION:
277             buffer[pos++] = (caps.header_compression.back_ch << 7) | (caps.header_compression.media << 6) | (caps.header_compression.recovery << 5);
278             break;
279         case AVDTP_MULTIPLEXING:
280             buffer[pos++] = caps.multiplexing_mode.fragmentation << 7;
281             for (i=0; i<caps.multiplexing_mode.transport_identifiers_num; i++){
282                 buffer[pos++] = caps.multiplexing_mode.transport_session_identifiers[i] << 7;
283                 buffer[pos++] = caps.multiplexing_mode.tcid[i] << 7;
284                 // media, reporting. recovery
285             }
286             break;
287         case AVDTP_MEDIA_CODEC:
288             buffer[pos++] = ((uint8_t)caps.media_codec.media_type) << 4;
289             buffer[pos++] = (uint8_t)caps.media_codec.media_codec_type;
290             for (i = 0; i<caps.media_codec.media_codec_information_len; i++){
291                 buffer[pos++] = caps.media_codec.media_codec_information[i];
292             }
293             break;
294         default:
295             break;
296     }
297     buffer[0] = pos - 1; // length
298     return pos;
299 }
300 
301 static int avdtp_unpack_service_capabilities_has_errors(avdtp_connection_t * connection, avdtp_signal_identifier_t signal_identifier, avdtp_service_category_t category, uint8_t cap_len){
302     connection->error_code = 0;
303 
304     if ((category == AVDTP_SERVICE_CATEGORY_INVALID_0) ||
305         ((category == AVDTP_SERVICE_CATEGORY_INVALID_FF) && (signal_identifier == AVDTP_SI_RECONFIGURE))){
306         log_info("    ERROR: BAD SERVICE CATEGORY %d\n", category);
307         connection->reject_service_category = category;
308         connection->error_code = BAD_SERV_CATEGORY;
309         return 1;
310     }
311 
312     if (signal_identifier == AVDTP_SI_RECONFIGURE){
313         if ( (category != AVDTP_CONTENT_PROTECTION) && (category != AVDTP_MEDIA_CODEC)){
314             log_info("    ERROR: REJECT CATEGORY, INVALID_CAPABILITIES\n");
315             connection->reject_service_category = category;
316             connection->error_code = INVALID_CAPABILITIES;
317             return 1;
318         }
319     }
320 
321     switch(category){
322         case AVDTP_MEDIA_TRANSPORT:
323             if (cap_len != 0){
324                 log_info("    ERROR: REJECT CATEGORY, BAD_MEDIA_TRANSPORT\n");
325                 connection->reject_service_category = category;
326                 connection->error_code = BAD_MEDIA_TRANSPORT_FORMAT;
327                 return 1;
328             }
329             break;
330         case AVDTP_REPORTING:
331         case AVDTP_DELAY_REPORTING:
332             if (cap_len != 0){
333                 log_info("    ERROR: REJECT CATEGORY, BAD_LENGTH\n");
334                 connection->reject_service_category = category;
335                 connection->error_code = BAD_LENGTH;
336                 return 1;
337             }
338             break;
339         case AVDTP_RECOVERY:
340             if (cap_len != 3){
341                 log_info("    ERROR: REJECT CATEGORY, BAD_MEDIA_TRANSPORT\n");
342                 connection->reject_service_category = category;
343                 connection->error_code = BAD_RECOVERY_FORMAT;
344                 return 1;
345             }
346             break;
347         case AVDTP_CONTENT_PROTECTION:
348             if (cap_len < 2){
349                 log_info("    ERROR: REJECT CATEGORY, BAD_CP_FORMAT\n");
350                 connection->reject_service_category = category;
351                 connection->error_code = BAD_CP_FORMAT;
352                 return 1;
353             }
354             break;
355         case AVDTP_HEADER_COMPRESSION:
356             // TODO: find error code for bad header compression
357             if (cap_len != 1){
358                 log_info("    ERROR: REJECT CATEGORY, BAD_HEADER_COMPRESSION\n");
359                 connection->reject_service_category = category;
360                 connection->error_code = BAD_RECOVERY_FORMAT;
361                 return 1;
362             }
363             break;
364         case AVDTP_MULTIPLEXING:
365             break;
366         case AVDTP_MEDIA_CODEC:
367             break;
368         default:
369             break;
370     }
371     return 0;
372 }
373 
374 uint16_t avdtp_unpack_service_capabilities(avdtp_connection_t * connection, avdtp_signal_identifier_t signal_identifier, avdtp_capabilities_t * caps, uint8_t * packet, uint16_t size){
375 
376     int i;
377 
378     uint16_t registered_service_categories = 0;
379     uint16_t to_process = size;
380 
381     while (to_process >= 2){
382 
383         avdtp_service_category_t category = (avdtp_service_category_t) packet[0];
384         uint8_t cap_len = packet[1];
385         packet     += 2;
386         to_process -= 2;
387 
388         if (cap_len > to_process){
389             connection->reject_service_category = category;
390             connection->error_code = BAD_LENGTH;
391             return 0;
392         }
393 
394         if (avdtp_unpack_service_capabilities_has_errors(connection, signal_identifier, category, cap_len)) return 0;
395 
396         int category_valid = 1;
397 
398         uint8_t * data = packet;
399         uint16_t  pos = 0;
400 
401         switch(category){
402             case AVDTP_RECOVERY:
403                 caps->recovery.recovery_type = data[pos++];
404                 caps->recovery.maximum_recovery_window_size = data[pos++];
405                 caps->recovery.maximum_number_media_packets = data[pos++];
406                 break;
407             case AVDTP_CONTENT_PROTECTION:
408                 caps->content_protection.cp_type = big_endian_read_16(data, 0);
409                 caps->content_protection.cp_type_value_len = cap_len - 2;
410                 // connection->reject_service_category = category;
411                 // connection->error_code = UNSUPPORTED_CONFIGURATION;
412                 // support for content protection goes here
413                 break;
414             case AVDTP_HEADER_COMPRESSION:
415                 caps->header_compression.back_ch  = (data[0] >> 7) & 1;
416                 caps->header_compression.media    = (data[0] >> 6) & 1;
417                 caps->header_compression.recovery = (data[0] >> 5) & 1;
418                 break;
419             case AVDTP_MULTIPLEXING:
420                 caps->multiplexing_mode.fragmentation = (data[pos++] >> 7) & 1;
421                 // read [tsid, tcid] for media, reporting. recovery respectively
422                 caps->multiplexing_mode.transport_identifiers_num = 3;
423                 for (i=0; i<caps->multiplexing_mode.transport_identifiers_num; i++){
424                     caps->multiplexing_mode.transport_session_identifiers[i] = (data[pos++] >> 7) & 1;
425                     caps->multiplexing_mode.tcid[i] = (data[pos++] >> 7) & 1;
426                 }
427                 break;
428             case AVDTP_MEDIA_CODEC:
429                 caps->media_codec.media_type = (avdtp_media_type_t)(data[pos++] >> 4);
430                 caps->media_codec.media_codec_type = (avdtp_media_codec_type_t)(data[pos++]);
431                 caps->media_codec.media_codec_information_len = cap_len - 2;
432                 caps->media_codec.media_codec_information = &data[pos++];
433                 break;
434             case AVDTP_MEDIA_TRANSPORT:
435             case AVDTP_REPORTING:
436             case AVDTP_DELAY_REPORTING:
437                 break;
438             default:
439                 category_valid = 0;
440                 break;
441         }
442 
443         if (category_valid) {
444             registered_service_categories = store_bit16(registered_service_categories, category, 1);
445         }
446 
447         packet     += cap_len;
448         to_process -= cap_len;
449     }
450 
451     return registered_service_categories;
452 }
453 
454 void avdtp_prepare_capabilities(avdtp_signaling_packet_t * signaling_packet, uint8_t transaction_label, uint16_t registered_service_categories, avdtp_capabilities_t capabilities, uint8_t identifier){
455     if (signaling_packet->offset) return;
456     uint8_t pack_all_capabilities = 1;
457     signaling_packet->message_type = AVDTP_RESPONSE_ACCEPT_MSG;
458     int i;
459 
460     signaling_packet->size = 0;
461     memset(signaling_packet->command, 0 , sizeof(signaling_packet->command));
462 
463 
464     switch (identifier) {
465         case AVDTP_SI_GET_CAPABILITIES:
466             pack_all_capabilities = 0;
467             break;
468         case AVDTP_SI_GET_ALL_CAPABILITIES:
469             pack_all_capabilities = 1;
470             break;
471         case AVDTP_SI_SET_CONFIGURATION:
472             signaling_packet->command[signaling_packet->size++] = signaling_packet->acp_seid << 2;
473             signaling_packet->command[signaling_packet->size++] = signaling_packet->int_seid << 2;
474             signaling_packet->message_type = AVDTP_CMD_MSG;
475             break;
476         case AVDTP_SI_RECONFIGURE:
477             signaling_packet->command[signaling_packet->size++] = signaling_packet->acp_seid << 2;
478             signaling_packet->message_type = AVDTP_CMD_MSG;
479             break;
480         default:
481             log_error("avdtp_prepare_capabilities wrong identifier %d", identifier);
482             break;
483     }
484 
485     for (i = 1; i < 9; i++){
486         int registered_category = get_bit16(registered_service_categories, i);
487         if (!registered_category && (identifier == AVDTP_SI_SET_CONFIGURATION)){
488             // TODO: introduce bitmap of mandatory categories
489             if (i == 1){
490                 registered_category = 1;
491             }
492         }
493         if (registered_category){
494             // service category
495             signaling_packet->command[signaling_packet->size++] = i;
496             signaling_packet->size += avdtp_pack_service_capabilities(signaling_packet->command+signaling_packet->size, sizeof(signaling_packet->command)-signaling_packet->size, capabilities, (avdtp_service_category_t)i, pack_all_capabilities);
497         }
498     }
499     signaling_packet->signal_identifier = (avdtp_signal_identifier_t)identifier;
500     signaling_packet->transaction_label = transaction_label;
501 }
502 
503 int avdtp_signaling_create_fragment(uint16_t cid, avdtp_signaling_packet_t * signaling_packet, uint8_t * out_buffer) {
504     int mtu = l2cap_get_remote_mtu_for_local_cid(cid);
505     int data_len = 0;
506 
507     uint16_t offset = signaling_packet->offset;
508     uint16_t pos = 1;
509 
510     if (offset == 0){
511         if (signaling_packet->size <= (mtu - 2)){
512             signaling_packet->packet_type = AVDTP_SINGLE_PACKET;
513             out_buffer[pos++] = signaling_packet->signal_identifier;
514             data_len = signaling_packet->size;
515         } else {
516             signaling_packet->packet_type = AVDTP_START_PACKET;
517             out_buffer[pos++] = (mtu + signaling_packet->size)/ (mtu-1);
518             out_buffer[pos++] = signaling_packet->signal_identifier;
519             data_len = mtu - 3;
520             signaling_packet->offset = data_len;
521         }
522     } else {
523         int remaining_bytes = signaling_packet->size - offset;
524         if (remaining_bytes <= (mtu - 1)){
525             signaling_packet->packet_type = AVDTP_END_PACKET;
526             data_len = remaining_bytes;
527             signaling_packet->offset = 0;
528         } else{
529             signaling_packet->packet_type = AVDTP_CONTINUE_PACKET;
530             data_len = mtu - 1;
531             signaling_packet->offset += data_len;
532         }
533     }
534     out_buffer[0] = avdtp_header(signaling_packet->transaction_label, signaling_packet->packet_type, signaling_packet->message_type);
535     (void)memcpy(out_buffer + pos, signaling_packet->command + offset,
536                  data_len);
537     pos += data_len;
538     return pos;
539 }
540 
541 
542 void avdtp_signaling_emit_connection_established(btstack_packet_handler_t callback, uint16_t avdtp_cid, bd_addr_t addr, uint8_t status){
543     if (!callback) return;
544     uint8_t event[12];
545     int pos = 0;
546     event[pos++] = HCI_EVENT_AVDTP_META;
547     event[pos++] = sizeof(event) - 2;
548     event[pos++] = AVDTP_SUBEVENT_SIGNALING_CONNECTION_ESTABLISHED;
549     little_endian_store_16(event, pos, avdtp_cid);
550     pos += 2;
551     reverse_bd_addr(addr,&event[pos]);
552     pos += 6;
553     event[pos++] = status;
554     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
555 }
556 
557 void avdtp_streaming_emit_can_send_media_packet_now(btstack_packet_handler_t callback, uint16_t avdtp_cid, uint8_t seid, uint16_t sequence_number){
558     if (!callback) return;
559     uint8_t event[8];
560     int pos = 0;
561     event[pos++] = HCI_EVENT_AVDTP_META;
562     event[pos++] = sizeof(event) - 2;
563     event[pos++] = AVDTP_SUBEVENT_STREAMING_CAN_SEND_MEDIA_PACKET_NOW;
564     little_endian_store_16(event, pos, avdtp_cid);
565     pos += 2;
566     event[pos++] = seid;
567     little_endian_store_16(event, pos, sequence_number);
568     pos += 2;
569     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
570 }
571 
572 void avdtp_signaling_emit_connection_released(btstack_packet_handler_t callback, uint16_t avdtp_cid){
573     if (!callback) return;
574     uint8_t event[5];
575     int pos = 0;
576     event[pos++] = HCI_EVENT_AVDTP_META;
577     event[pos++] = sizeof(event) - 2;
578     event[pos++] = AVDTP_SUBEVENT_SIGNALING_CONNECTION_RELEASED;
579     little_endian_store_16(event, pos, avdtp_cid);
580     pos += 2;
581     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
582 }
583 
584 void avdtp_streaming_emit_connection_released(btstack_packet_handler_t callback, uint16_t avdtp_cid, uint8_t local_seid){
585     if (!callback) return;
586     uint8_t event[6];
587     int pos = 0;
588     event[pos++] = HCI_EVENT_AVDTP_META;
589     event[pos++] = sizeof(event) - 2;
590     event[pos++] = AVDTP_SUBEVENT_STREAMING_CONNECTION_RELEASED;
591     little_endian_store_16(event, pos, avdtp_cid);
592     pos += 2;
593     event[pos++] = local_seid;
594     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
595 }
596 
597 void avdtp_streaming_emit_connection_established(btstack_packet_handler_t callback, uint16_t avdtp_cid, bd_addr_t addr, uint8_t local_seid, uint8_t remote_seid, uint8_t status){
598     if (!callback) return;
599     uint8_t event[14];
600     int pos = 0;
601     event[pos++] = HCI_EVENT_AVDTP_META;
602     event[pos++] = sizeof(event) - 2;
603     event[pos++] = AVDTP_SUBEVENT_STREAMING_CONNECTION_ESTABLISHED;
604     little_endian_store_16(event, pos, avdtp_cid);
605     pos += 2;
606     reverse_bd_addr(addr,&event[pos]);
607     pos += 6;
608     event[pos++] = local_seid;
609     event[pos++] = remote_seid;
610     event[pos++] = status;
611     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
612 }
613 
614 void avdtp_signaling_emit_sep(btstack_packet_handler_t callback, uint16_t avdtp_cid, avdtp_sep_t sep){
615     if (!callback) return;
616     uint8_t event[9];
617     int pos = 0;
618     event[pos++] = HCI_EVENT_AVDTP_META;
619     event[pos++] = sizeof(event) - 2;
620     event[pos++] = AVDTP_SUBEVENT_SIGNALING_SEP_FOUND;
621     little_endian_store_16(event, pos, avdtp_cid);
622     pos += 2;
623     event[pos++] = sep.seid;
624     event[pos++] = sep.in_use;
625     event[pos++] = sep.media_type;
626     event[pos++] = sep.type;
627     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
628 }
629 
630 void avdtp_signaling_emit_sep_done(btstack_packet_handler_t callback, uint16_t avdtp_cid){
631     if (!callback) return;
632     uint8_t event[5];
633     int pos = 0;
634     event[pos++] = HCI_EVENT_AVDTP_META;
635     event[pos++] = sizeof(event) - 2;
636     event[pos++] = AVDTP_SUBEVENT_SIGNALING_SEP_DICOVERY_DONE;
637     little_endian_store_16(event, pos, avdtp_cid);
638     pos += 2;
639     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
640 }
641 
642 void avdtp_signaling_emit_delay(btstack_packet_handler_t callback, uint16_t avdtp_cid, uint8_t local_seid, uint16_t delay){
643     if (!callback) return;
644     uint8_t event[8];
645     int pos = 0;
646     event[pos++] = HCI_EVENT_AVDTP_META;
647     event[pos++] = sizeof(event) - 2;
648     event[pos++] = AVDTP_SUBEVENT_SIGNALING_DELAY_REPORT;
649     little_endian_store_16(event, pos, avdtp_cid);
650     pos += 2;
651     event[pos++] = local_seid;
652     little_endian_store_16(event, pos, delay);
653     pos += 2;
654     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
655 }
656 
657 void avdtp_signaling_emit_accept(btstack_packet_handler_t callback, uint16_t avdtp_cid, uint8_t local_seid, avdtp_signal_identifier_t identifier, bool is_initiator){
658     if (!callback) return;
659     uint8_t event[8];
660     int pos = 0;
661     event[pos++] = HCI_EVENT_AVDTP_META;
662     event[pos++] = sizeof(event) - 2;
663     event[pos++] = AVDTP_SUBEVENT_SIGNALING_ACCEPT;
664     little_endian_store_16(event, pos, avdtp_cid);
665     pos += 2;
666     event[pos++] = local_seid;
667     event[pos++] = is_initiator ? 1 : 0;
668     event[pos++] = identifier;
669     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
670 }
671 
672 void avdtp_signaling_emit_reject(btstack_packet_handler_t callback, uint16_t avdtp_cid, uint8_t local_seid, avdtp_signal_identifier_t identifier, bool is_initiator){
673     if (!callback) return;
674     uint8_t event[8];
675     int pos = 0;
676     event[pos++] = HCI_EVENT_AVDTP_META;
677     event[pos++] = sizeof(event) - 2;
678     event[pos++] = AVDTP_SUBEVENT_SIGNALING_REJECT;
679     little_endian_store_16(event, pos, avdtp_cid);
680     pos += 2;
681     event[pos++] = local_seid;
682     event[pos++] = is_initiator ? 1 : 0;
683     event[pos++] = identifier;
684     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
685 }
686 
687 void avdtp_signaling_emit_general_reject(btstack_packet_handler_t callback, uint16_t avdtp_cid, uint8_t local_seid, avdtp_signal_identifier_t identifier, bool is_initiator){
688     if (!callback) return;
689     uint8_t event[8];
690     int pos = 0;
691     event[pos++] = HCI_EVENT_AVDTP_META;
692     event[pos++] = sizeof(event) - 2;
693     event[pos++] = AVDTP_SUBEVENT_SIGNALING_GENERAL_REJECT;
694     little_endian_store_16(event, pos, avdtp_cid);
695     pos += 2;
696     event[pos++] = local_seid;
697     event[pos++] = is_initiator ? 1 : 0;
698     event[pos++] = identifier;
699     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
700 }
701 
702 static void avdtp_signaling_emit_media_codec_sbc_capability(btstack_packet_handler_t callback, uint16_t avdtp_cid, uint8_t local_seid, uint8_t remote_seid, adtvp_media_codec_capabilities_t media_codec){
703     if (!callback) return;
704     uint8_t event[15];
705     int pos = 0;
706     event[pos++] = HCI_EVENT_AVDTP_META;
707     event[pos++] = sizeof(event) - 2;
708     event[pos++] = AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_SBC_CAPABILITY;
709     little_endian_store_16(event, pos, avdtp_cid);
710     pos += 2;
711     event[pos++] = local_seid;
712     event[pos++] = remote_seid;
713     event[pos++] = media_codec.media_type;
714     event[pos++] = media_codec.media_codec_information[0] >> 4;
715     event[pos++] = media_codec.media_codec_information[0] & 0x0F;
716     event[pos++] = media_codec.media_codec_information[1] >> 4;
717     event[pos++] = (media_codec.media_codec_information[1] & 0x0F) >> 2;
718     event[pos++] = media_codec.media_codec_information[1] & 0x03;
719     event[pos++] = media_codec.media_codec_information[2];
720     event[pos++] = media_codec.media_codec_information[3];
721     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
722 }
723 
724 static inline void avdtp_signaling_emit_capability(btstack_packet_handler_t callback, uint8_t capability_subevent_id, uint16_t avdtp_cid, uint8_t local_seid, uint8_t remote_seid){
725     if (!callback) return;
726     uint8_t event[7];
727     int pos = 0;
728     event[pos++] = HCI_EVENT_AVDTP_META;
729     event[pos++] = sizeof(event) - 2;
730     event[pos++] = capability_subevent_id;
731     little_endian_store_16(event, pos, avdtp_cid);
732     pos += 2;
733     event[pos++] = local_seid;
734     event[pos++] = remote_seid;
735     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
736 }
737 
738 static void avdtp_signaling_emit_media_transport_capability(btstack_packet_handler_t callback, uint16_t avdtp_cid, uint8_t local_seid, uint8_t remote_seid){
739     avdtp_signaling_emit_capability(callback, AVDTP_SUBEVENT_SIGNALING_MEDIA_TRANSPORT_CAPABILITY, avdtp_cid, local_seid, remote_seid);
740 }
741 
742 static void avdtp_signaling_emit_reporting_capability(btstack_packet_handler_t callback, uint16_t avdtp_cid, uint8_t local_seid, uint8_t remote_seid){
743     avdtp_signaling_emit_capability(callback, AVDTP_SUBEVENT_SIGNALING_REPORTING_CAPABILITY, avdtp_cid, local_seid, remote_seid);
744 }
745 
746 static void avdtp_signaling_emit_delay_reporting_capability(btstack_packet_handler_t callback, uint16_t avdtp_cid, uint8_t local_seid, uint8_t remote_seid){
747     avdtp_signaling_emit_capability(callback, AVDTP_SUBEVENT_SIGNALING_DELAY_REPORTING_CAPABILITY, avdtp_cid, local_seid, remote_seid);
748 }
749 
750 static void avdtp_signaling_emit_recovery_capability(btstack_packet_handler_t callback, uint16_t avdtp_cid, uint8_t local_seid, uint8_t remote_seid, avdtp_recovery_capabilities_t * recovery){
751     if (!callback) return;
752     uint8_t event[10];
753     int pos = 0;
754     event[pos++] = HCI_EVENT_AVDTP_META;
755     event[pos++] = sizeof(event) - 2;
756     event[pos++] = AVDTP_SUBEVENT_SIGNALING_RECOVERY_CAPABILITY;
757     little_endian_store_16(event, pos, avdtp_cid);
758     pos += 2;
759     event[pos++] = local_seid;
760     event[pos++] = remote_seid;
761     event[pos++] = recovery->recovery_type;
762     event[pos++] = recovery->maximum_recovery_window_size;
763     event[pos++] = recovery->maximum_number_media_packets;
764     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
765 }
766 
767 static void avdtp_signaling_emit_content_protection_capability(btstack_packet_handler_t callback, uint16_t avdtp_cid, uint8_t local_seid, uint8_t remote_seid, adtvp_content_protection_t * content_protection){
768     if (!callback) return;
769     uint8_t event[22];
770     int pos = 0;
771     event[pos++] = HCI_EVENT_AVDTP_META;
772     event[pos++] = sizeof(event) - 2;
773     event[pos++] = AVDTP_SUBEVENT_SIGNALING_CONTENT_PROTECTION_CAPABILITY;
774     little_endian_store_16(event, pos, avdtp_cid);
775     pos += 2;
776     event[pos++] = local_seid;
777     event[pos++] = remote_seid;
778 
779     little_endian_store_16(event, pos, content_protection->cp_type);
780     pos += 2;
781     little_endian_store_16(event, pos, content_protection->cp_type_value_len);
782     pos += 2;
783 
784     //TODO: reserve place for value
785     if (content_protection->cp_type_value_len < 10){
786         (void)memcpy(event + pos, content_protection->cp_type_value,
787                      content_protection->cp_type_value_len);
788     }
789     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
790 }
791 
792 
793 static void avdtp_signaling_emit_header_compression_capability(btstack_packet_handler_t callback, uint16_t avdtp_cid, uint8_t local_seid, uint8_t remote_seid, avdtp_header_compression_capabilities_t * header_compression){
794         if (!callback) return;
795     uint8_t event[10];
796     int pos = 0;
797     event[pos++] = HCI_EVENT_AVDTP_META;
798     event[pos++] = sizeof(event) - 2;
799     event[pos++] = AVDTP_SUBEVENT_SIGNALING_HEADER_COMPRESSION_CAPABILITY;
800     little_endian_store_16(event, pos, avdtp_cid);
801     pos += 2;
802     event[pos++] = local_seid;
803     event[pos++] = remote_seid;
804     event[pos++] = header_compression->back_ch;
805     event[pos++] = header_compression->media;
806     event[pos++] = header_compression->recovery;
807     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
808 }
809 
810 static void avdtp_signaling_emit_content_multiplexing_capability(btstack_packet_handler_t callback, uint16_t avdtp_cid, uint8_t local_seid, uint8_t remote_seid, avdtp_multiplexing_mode_capabilities_t * multiplexing_mode){
811     if (!callback) return;
812     uint8_t event[15];
813     int pos = 0;
814     event[pos++] = HCI_EVENT_AVDTP_META;
815     event[pos++] = sizeof(event) - 2;
816     event[pos++] = AVDTP_SUBEVENT_SIGNALING_MULTIPLEXING_CAPABILITY;
817     little_endian_store_16(event, pos, avdtp_cid);
818     pos += 2;
819     event[pos++] = local_seid;
820     event[pos++] = remote_seid;
821 
822     event[pos++] = multiplexing_mode->fragmentation;
823     event[pos++] = multiplexing_mode->transport_identifiers_num;
824 
825     int i;
826     for (i = 0; i < 3; i++){
827         event[pos++] = multiplexing_mode->transport_session_identifiers[i];
828     }
829     for (i = 0; i < 3; i++){
830         event[pos++] = multiplexing_mode->tcid[i];
831     }
832     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
833 }
834 
835 static void avdtp_signaling_emit_media_codec_other_capability(btstack_packet_handler_t callback, uint16_t avdtp_cid, uint8_t local_seid, uint8_t remote_seid, adtvp_media_codec_capabilities_t media_codec){
836     if (!callback) return;
837     uint8_t event[MAX_MEDIA_CODEC_INFORMATION_LENGTH + 12];
838     int pos = 0;
839     event[pos++] = HCI_EVENT_AVDTP_META;
840     event[pos++] = sizeof(event) - 2;
841     event[pos++] = AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_OTHER_CAPABILITY;
842     little_endian_store_16(event, pos, avdtp_cid);
843     pos += 2;
844     event[pos++] = local_seid;
845     event[pos++] = remote_seid;
846     event[pos++] = media_codec.media_type;
847     little_endian_store_16(event, pos, media_codec.media_codec_type);
848     pos += 2;
849     little_endian_store_16(event, pos, media_codec.media_codec_information_len);
850     pos += 2;
851     (void)memcpy(event + pos, media_codec.media_codec_information,
852                  btstack_min(media_codec.media_codec_information_len, MAX_MEDIA_CODEC_INFORMATION_LENGTH));
853     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
854 }
855 
856 static inline void avdtp_signaling_emit_media_codec_sbc(btstack_packet_handler_t callback, uint16_t avdtp_cid, uint8_t local_seid, uint8_t remote_seid,
857     avdtp_media_type_t media_type, const uint8_t * media_codec_information, uint8_t reconfigure) {
858     if (!callback) return;
859     uint8_t event[16 + 2];
860     int pos = 0;
861     event[pos++] = HCI_EVENT_AVDTP_META;
862     event[pos++] = sizeof(event) - 2;
863 
864     event[pos++] = AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_SBC_CONFIGURATION;
865     little_endian_store_16(event, pos, avdtp_cid);
866     pos += 2;
867     event[pos++] = local_seid;
868     event[pos++] = remote_seid;
869     event[pos++] = reconfigure;
870 
871 
872     uint8_t sampling_frequency_bitmap = media_codec_information[0] >> 4;
873     uint8_t channel_mode_bitmap = media_codec_information[0] & 0x0F;
874     uint8_t block_length_bitmap = media_codec_information[1] >> 4;
875     uint8_t subbands_bitmap = (media_codec_information[1] & 0x0F) >> 2;
876 
877     uint8_t num_channels = 0;
878     if ((channel_mode_bitmap & AVDTP_SBC_JOINT_STEREO) ||
879         (channel_mode_bitmap & AVDTP_SBC_STEREO) ||
880         (channel_mode_bitmap & AVDTP_SBC_DUAL_CHANNEL)) {
881         num_channels = 2;
882     } else if (channel_mode_bitmap & AVDTP_SBC_MONO) {
883         num_channels = 1;
884     }
885 
886     uint16_t sampling_frequency = 0;
887     if (sampling_frequency_bitmap & AVDTP_SBC_48000) {
888         sampling_frequency = 48000;
889     } else if (sampling_frequency_bitmap & AVDTP_SBC_44100) {
890         sampling_frequency = 44100;
891     } else if (sampling_frequency_bitmap & AVDTP_SBC_32000) {
892         sampling_frequency = 32000;
893     } else if (sampling_frequency_bitmap & AVDTP_SBC_16000) {
894         sampling_frequency = 16000;
895     }
896 
897     uint8_t subbands = 0;
898     if (subbands_bitmap & AVDTP_SBC_SUBBANDS_8){
899         subbands = 8;
900     } else if (subbands_bitmap & AVDTP_SBC_SUBBANDS_4){
901         subbands = 4;
902     }
903 
904     uint8_t block_length = 0;
905     if (block_length_bitmap & AVDTP_SBC_BLOCK_LENGTH_16){
906         block_length = 16;
907     } else if (block_length_bitmap & AVDTP_SBC_BLOCK_LENGTH_12){
908         block_length = 12;
909     } else if (block_length_bitmap & AVDTP_SBC_BLOCK_LENGTH_8){
910         block_length = 8;
911     } else if (block_length_bitmap & AVDTP_SBC_BLOCK_LENGTH_4){
912         block_length = 4;
913     }
914 
915     event[pos++] = media_type;
916     little_endian_store_16(event, pos, sampling_frequency);
917     pos += 2;
918 
919     event[pos++] = channel_mode_bitmap;
920     event[pos++] = num_channels;
921     event[pos++] = block_length;
922     event[pos++] = subbands;
923     event[pos++] = media_codec_information[1] & 0x03;
924     event[pos++] = media_codec_information[2];
925     event[pos++] = media_codec_information[3];
926     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
927 }
928 
929 void avdtp_signaling_emit_media_codec_sbc_configuration(btstack_packet_handler_t callback, uint16_t avdtp_cid, uint8_t local_seid, uint8_t remote_seid, avdtp_media_type_t media_type, const uint8_t * media_codec_information){
930     if (!callback) return;
931     avdtp_signaling_emit_media_codec_sbc(callback, avdtp_cid, local_seid, remote_seid, media_type, media_codec_information, 0);
932 }
933 
934 void avdtp_signaling_emit_media_codec_sbc_reconfiguration(btstack_packet_handler_t callback, uint16_t avdtp_cid, uint8_t local_seid, uint8_t remote_seid, avdtp_media_type_t media_type, const uint8_t * media_codec_information){
935     if (!callback) return;
936     avdtp_signaling_emit_media_codec_sbc(callback, avdtp_cid, local_seid, remote_seid, media_type, media_codec_information, 1);
937 }
938 
939 
940 static inline void avdtp_signaling_emit_media_codec_other(btstack_packet_handler_t callback, uint16_t avdtp_cid, uint8_t local_seid, uint8_t remote_seid, adtvp_media_codec_capabilities_t media_codec, uint8_t reconfigure){
941     uint8_t event[MAX_MEDIA_CODEC_INFORMATION_LENGTH + 13];
942     int pos = 0;
943     event[pos++] = HCI_EVENT_AVDTP_META;
944     event[pos++] = sizeof(event) - 2;
945     event[pos++] = AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_OTHER_CONFIGURATION;
946     little_endian_store_16(event, pos, avdtp_cid);
947     pos += 2;
948     event[pos++] = local_seid;
949     event[pos++] = remote_seid;
950     event[pos++] = reconfigure;
951     event[pos++] = media_codec.media_type;
952     little_endian_store_16(event, pos, media_codec.media_codec_type);
953     pos += 2;
954     little_endian_store_16(event, pos, media_codec.media_codec_information_len);
955     pos += 2;
956 
957     int media_codec_len = btstack_min(MAX_MEDIA_CODEC_INFORMATION_LENGTH, media_codec.media_codec_information_len);
958     (void)memcpy(event + pos, media_codec.media_codec_information,
959                  media_codec_len);
960 
961     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
962 }
963 
964 static void avdtp_signaling_emit_capability_done(btstack_packet_handler_t callback, uint16_t avdtp_cid, uint8_t local_seid, uint8_t remote_seid){
965     if (!callback) return;
966     uint8_t event[7];
967     int pos = 0;
968     event[pos++] = HCI_EVENT_AVDTP_META;
969     event[pos++] = sizeof(event) - 2;
970     event[pos++] = AVDTP_SUBEVENT_SIGNALING_CAPABILITIES_DONE;
971     little_endian_store_16(event, pos, avdtp_cid);
972     pos += 2;
973     event[pos++] = local_seid;
974     event[pos++] = remote_seid;
975     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
976 }
977 
978 void avdtp_signaling_emit_media_codec_other_configuration(btstack_packet_handler_t callback, uint16_t avdtp_cid, uint8_t local_seid, uint8_t remote_seid, adtvp_media_codec_capabilities_t media_codec){
979     if (!callback) return;
980     avdtp_signaling_emit_media_codec_other(callback, avdtp_cid, local_seid, remote_seid, media_codec, 0);
981 }
982 
983 void avdtp_signaling_emit_media_codec_other_reconfiguration(btstack_packet_handler_t callback, uint16_t avdtp_cid, uint8_t local_seid, uint8_t remote_seid, adtvp_media_codec_capabilities_t media_codec){
984     if (!callback) return;
985     avdtp_signaling_emit_media_codec_other(callback, avdtp_cid, local_seid, remote_seid, media_codec, 1);
986 }
987 
988 void avdtp_emit_capabilities(btstack_packet_handler_t callback, uint16_t avdtp_cid, uint8_t local_seid, uint8_t remote_seid, avdtp_capabilities_t * capabilities, uint16_t registered_service_categories){
989     if (get_bit16(registered_service_categories, AVDTP_MEDIA_CODEC)){
990         switch (capabilities->media_codec.media_codec_type){
991             case AVDTP_CODEC_SBC:
992                 avdtp_signaling_emit_media_codec_sbc_capability(callback, avdtp_cid, local_seid, remote_seid, capabilities->media_codec);
993                 break;
994             default:
995                 avdtp_signaling_emit_media_codec_other_capability(callback, avdtp_cid, local_seid, remote_seid, capabilities->media_codec);
996                 break;
997         }
998     }
999 
1000     if (get_bit16(registered_service_categories, AVDTP_MEDIA_TRANSPORT)){
1001         avdtp_signaling_emit_media_transport_capability(callback, avdtp_cid, local_seid, remote_seid);
1002     }
1003     if (get_bit16(registered_service_categories, AVDTP_REPORTING)){
1004         avdtp_signaling_emit_reporting_capability(callback, avdtp_cid, local_seid, remote_seid);
1005     }
1006     if (get_bit16(registered_service_categories, AVDTP_RECOVERY)){
1007         avdtp_signaling_emit_recovery_capability(callback, avdtp_cid, local_seid, remote_seid, &capabilities->recovery);
1008     }
1009     if (get_bit16(registered_service_categories, AVDTP_CONTENT_PROTECTION)){
1010         avdtp_signaling_emit_content_protection_capability(callback, avdtp_cid, local_seid, remote_seid, &capabilities->content_protection);
1011     }
1012     if (get_bit16(registered_service_categories, AVDTP_HEADER_COMPRESSION)){
1013         avdtp_signaling_emit_header_compression_capability(callback, avdtp_cid, local_seid, remote_seid, &capabilities->header_compression);
1014     }
1015     if (get_bit16(registered_service_categories, AVDTP_MULTIPLEXING)){
1016         avdtp_signaling_emit_content_multiplexing_capability(callback, avdtp_cid, local_seid, remote_seid, &capabilities->multiplexing_mode);
1017     }
1018     if (get_bit16(registered_service_categories, AVDTP_DELAY_REPORTING)){
1019         avdtp_signaling_emit_delay_reporting_capability(callback, avdtp_cid, local_seid, remote_seid);
1020     }
1021     avdtp_signaling_emit_capability_done(callback, avdtp_cid, local_seid, remote_seid);
1022 }
1023 
1024 void avdtp_emit_configuration(btstack_packet_handler_t callback, uint16_t avdtp_cid, uint8_t local_seid, uint8_t remote_seid, avdtp_capabilities_t * configuration, uint16_t configured_service_categories){
1025     if (get_bit16(configured_service_categories, AVDTP_MEDIA_CODEC)){
1026         switch (configuration->media_codec.media_codec_type){
1027             case AVDTP_CODEC_SBC:
1028                 avdtp_signaling_emit_media_codec_sbc_configuration(callback, avdtp_cid, local_seid, remote_seid,
1029                     configuration->media_codec.media_type, configuration->media_codec.media_codec_information);
1030                 break;
1031             default:
1032                 avdtp_signaling_emit_media_codec_other_configuration(callback, avdtp_cid, local_seid, remote_seid, configuration->media_codec);
1033                 break;
1034         }
1035     }
1036 }
1037 
1038 
1039 uint8_t avdtp_request_can_send_now_acceptor(avdtp_connection_t * connection, uint16_t l2cap_cid){
1040     if (!connection) return AVDTP_CONNECTION_DOES_NOT_EXIST;
1041     connection->wait_to_send_acceptor = 1;
1042     l2cap_request_can_send_now_event(l2cap_cid);
1043     return ERROR_CODE_SUCCESS;
1044 }
1045 
1046 uint8_t avdtp_request_can_send_now_initiator(avdtp_connection_t * connection, uint16_t l2cap_cid){
1047     if (!connection) return AVDTP_CONNECTION_DOES_NOT_EXIST;
1048     connection->wait_to_send_initiator = 1;
1049     l2cap_request_can_send_now_event(l2cap_cid);
1050     return ERROR_CODE_SUCCESS;
1051 }
1052 
1053 uint8_t avdtp_request_can_send_now_self(avdtp_connection_t * connection, uint16_t l2cap_cid){
1054     if (!connection) return AVDTP_CONNECTION_DOES_NOT_EXIST;
1055     connection->wait_to_send_self = 1;
1056     l2cap_request_can_send_now_event(l2cap_cid);
1057     return ERROR_CODE_SUCCESS;
1058 }
1059 
1060 uint8_t avdtp_local_seid(avdtp_stream_endpoint_t * stream_endpoint){
1061     if (!stream_endpoint) return 0;
1062     return stream_endpoint->sep.seid;
1063 
1064 }
1065 
1066 uint8_t avdtp_remote_seid(avdtp_stream_endpoint_t * stream_endpoint){
1067     if (!stream_endpoint) return AVDTP_INVALID_SEP_SEID;
1068     return stream_endpoint->remote_sep.seid;
1069 }
1070 
1071 void a2dp_streaming_emit_connection_established(btstack_packet_handler_t callback, uint16_t cid, bd_addr_t addr, uint8_t local_seid, uint8_t remote_seid, uint8_t status){
1072     if (!callback) return;
1073     uint8_t event[14];
1074     int pos = 0;
1075     event[pos++] = HCI_EVENT_A2DP_META;
1076     event[pos++] = sizeof(event) - 2;
1077     event[pos++] = A2DP_SUBEVENT_STREAM_ESTABLISHED;
1078     little_endian_store_16(event, pos, cid);
1079     pos += 2;
1080     reverse_bd_addr(addr,&event[pos]);
1081     pos += 6;
1082     event[pos++] = local_seid;
1083     event[pos++] = remote_seid;
1084     event[pos++] = status;
1085     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
1086 }
1087