xref: /btstack/src/classic/avdtp_util.c (revision d40c3de009bce6994e726da5a427e08951b353d9)
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 
41 #include <stdint.h>
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <string.h>
45 
46 #include "btstack.h"
47 #include "avdtp.h"
48 #include "avdtp_util.h"
49 
50 #define MAX_MEDIA_CODEC_INFORMATION_LENGTH 100
51 
52 static const char * avdtp_si_name[] = {
53     "ERROR",
54     "AVDTP_SI_DISCOVER",
55     "AVDTP_SI_GET_CAPABILITIES",
56     "AVDTP_SI_SET_CONFIGURATION",
57     "AVDTP_SI_GET_CONFIGURATION",
58     "AVDTP_SI_RECONFIGURE",
59     "AVDTP_SI_OPEN",
60     "AVDTP_SI_START",
61     "AVDTP_SI_CLOSE",
62     "AVDTP_SI_SUSPEND",
63     "AVDTP_SI_ABORT",
64     "AVDTP_SI_SECURITY_CONTROL",
65     "AVDTP_SI_GET_ALL_CAPABILITIES",
66     "AVDTP_SI_DELAY_REPORT"
67 };
68 const char * avdtp_si2str(uint16_t index){
69     if (index <= 0 || index > sizeof(avdtp_si_name)) return avdtp_si_name[0];
70     return avdtp_si_name[index];
71 }
72 
73 void avdtp_initialize_stream_endpoint(avdtp_stream_endpoint_t * stream_endpoint){
74     stream_endpoint->connection = NULL;
75     stream_endpoint->state = AVDTP_STREAM_ENDPOINT_IDLE;
76     stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_STREAM_CONFIG_IDLE;
77     stream_endpoint->initiator_config_state = AVDTP_INITIATOR_STREAM_CONFIG_IDLE;
78     stream_endpoint->remote_sep_index = AVDTP_INVALID_SEP_INDEX;
79     stream_endpoint->media_disconnect = 0;
80     stream_endpoint->sep.in_use = 0;
81     stream_endpoint->remote_sep_index = 0;
82 }
83 
84 avdtp_stream_endpoint_t * avdtp_stream_endpoint_for_seid(uint16_t seid, avdtp_context_t * context){
85     btstack_linked_list_iterator_t it;
86     btstack_linked_list_iterator_init(&it, &context->stream_endpoints);
87     while (btstack_linked_list_iterator_has_next(&it)){
88         avdtp_stream_endpoint_t * stream_endpoint = (avdtp_stream_endpoint_t *)btstack_linked_list_iterator_next(&it);
89         if (stream_endpoint->sep.seid == seid){
90             return stream_endpoint;
91         }
92     }
93     return NULL;
94 }
95 
96 avdtp_connection_t * avdtp_connection_for_bd_addr(bd_addr_t addr, avdtp_context_t * context){
97     btstack_linked_list_iterator_t it;
98     btstack_linked_list_iterator_init(&it, &context->connections);
99     while (btstack_linked_list_iterator_has_next(&it)){
100         avdtp_connection_t * connection = (avdtp_connection_t *)btstack_linked_list_iterator_next(&it);
101         if (memcmp(addr, connection->remote_addr, 6) != 0) continue;
102         return connection;
103     }
104     return NULL;
105 }
106 
107 avdtp_connection_t * avdtp_connection_for_avdtp_cid(uint16_t avdtp_cid, avdtp_context_t * context){
108     btstack_linked_list_iterator_t it;
109     btstack_linked_list_iterator_init(&it, &context->connections);
110     while (btstack_linked_list_iterator_has_next(&it)){
111         avdtp_connection_t * connection = (avdtp_connection_t *)btstack_linked_list_iterator_next(&it);
112         if (connection->avdtp_cid != avdtp_cid) continue;
113         return connection;
114     }
115     return NULL;
116 }
117 
118 avdtp_connection_t * avdtp_connection_for_l2cap_signaling_cid(uint16_t l2cap_cid, avdtp_context_t * context){
119     btstack_linked_list_iterator_t it;
120     btstack_linked_list_iterator_init(&it, &context->connections);
121     while (btstack_linked_list_iterator_has_next(&it)){
122         avdtp_connection_t * connection = (avdtp_connection_t *)btstack_linked_list_iterator_next(&it);
123         if (connection->l2cap_signaling_cid != l2cap_cid) continue;
124         return connection;
125     }
126     return NULL;
127 }
128 
129 avdtp_stream_endpoint_t * avdtp_stream_endpoint_for_l2cap_cid(uint16_t l2cap_cid, avdtp_context_t * context){
130     btstack_linked_list_iterator_t it;
131     btstack_linked_list_iterator_init(&it, &context->stream_endpoints);
132     while (btstack_linked_list_iterator_has_next(&it)){
133         avdtp_stream_endpoint_t * stream_endpoint = (avdtp_stream_endpoint_t *)btstack_linked_list_iterator_next(&it);
134         if (stream_endpoint->l2cap_media_cid == l2cap_cid){
135             return stream_endpoint;
136         }
137         if (stream_endpoint->l2cap_reporting_cid == l2cap_cid){
138             return stream_endpoint;
139         }
140         if (stream_endpoint->l2cap_recovery_cid == l2cap_cid){
141             return stream_endpoint;
142         }
143     }
144     return NULL;
145 }
146 
147 avdtp_stream_endpoint_t * avdtp_stream_endpoint_with_seid(uint8_t seid, avdtp_context_t * context){
148     btstack_linked_list_iterator_t it;
149     btstack_linked_list_iterator_init(&it, &context->stream_endpoints);
150     while (btstack_linked_list_iterator_has_next(&it)){
151         avdtp_stream_endpoint_t * stream_endpoint = (avdtp_stream_endpoint_t *)btstack_linked_list_iterator_next(&it);
152         if (stream_endpoint->sep.seid == seid){
153             return stream_endpoint;
154         }
155     }
156     return NULL;
157 }
158 
159 avdtp_stream_endpoint_t * avdtp_stream_endpoint_associated_with_acp_seid(uint16_t acp_seid, avdtp_context_t * context){
160     btstack_linked_list_iterator_t it;
161     btstack_linked_list_iterator_init(&it, &context->stream_endpoints);
162     while (btstack_linked_list_iterator_has_next(&it)){
163         avdtp_stream_endpoint_t * stream_endpoint = (avdtp_stream_endpoint_t *)btstack_linked_list_iterator_next(&it);
164 
165         if (stream_endpoint->remote_sep_index != AVDTP_INVALID_SEP_INDEX){
166             if (!stream_endpoint->connection) continue;
167             if (stream_endpoint->connection->remote_seps[stream_endpoint->remote_sep_index].seid == acp_seid){
168                 return stream_endpoint;
169             }
170         }
171     }
172     return NULL;
173 }
174 
175 int get_bit16(uint16_t bitmap, int position){
176     return (bitmap >> position) & 1;
177 }
178 
179 uint8_t store_bit16(uint16_t bitmap, int position, uint8_t value){
180     if (value){
181         bitmap |= 1 << position;
182     } else {
183         bitmap &= ~ (1 << position);
184     }
185     return bitmap;
186 }
187 
188 int avdtp_read_signaling_header(avdtp_signaling_packet_t * signaling_header, uint8_t * packet, uint16_t size){
189     int pos = 0;
190     if (size < 2) return pos;
191     signaling_header->transaction_label = packet[pos] >> 4;
192     signaling_header->packet_type = (avdtp_packet_type_t)((packet[pos] >> 2) & 0x03);
193     signaling_header->message_type = (avdtp_message_type_t) (packet[pos] & 0x03);
194     pos++;
195     memset(signaling_header->command, 0, sizeof(signaling_header->command));
196     switch (signaling_header->packet_type){
197         case AVDTP_SINGLE_PACKET:
198             signaling_header->num_packets = 0;
199             signaling_header->offset = 0;
200             signaling_header->size = 0;
201             break;
202         case AVDTP_END_PACKET:
203             signaling_header->num_packets = 0;
204             break;
205         case AVDTP_START_PACKET:
206             signaling_header->num_packets = packet[pos++];
207             signaling_header->size = 0;
208             signaling_header->offset = 0;
209             break;
210         case AVDTP_CONTINUE_PACKET:
211             if (signaling_header->num_packets <= 0) {
212                 log_info("    ERROR: wrong num fragmented packets\n");
213                 break;
214             }
215             signaling_header->num_packets--;
216             break;
217     }
218     signaling_header->signal_identifier = (avdtp_signal_identifier_t)(packet[pos++] & 0x3f);
219     return pos;
220 }
221 
222 int avdtp_pack_service_capabilities(uint8_t * buffer, int size, avdtp_capabilities_t caps, avdtp_service_category_t category, uint8_t pack_all_capabilities){
223     UNUSED(size);
224 
225     int i;
226     // pos = 0 reserved for length
227     int pos = 1;
228     switch(category){
229         case AVDTP_MEDIA_TRANSPORT:
230         case AVDTP_REPORTING:
231             break;
232         case AVDTP_DELAY_REPORTING:
233             if (!pack_all_capabilities) break;
234             break;
235         case AVDTP_RECOVERY:
236             buffer[pos++] = caps.recovery.recovery_type; // 0x01=RFC2733
237             buffer[pos++] = caps.recovery.maximum_recovery_window_size;
238             buffer[pos++] = caps.recovery.maximum_number_media_packets;
239             break;
240         case AVDTP_CONTENT_PROTECTION:
241             buffer[pos++] = caps.content_protection.cp_type_value_len + 2;
242             big_endian_store_16(buffer, pos, caps.content_protection.cp_type);
243             pos += 2;
244             memcpy(buffer+pos, caps.content_protection.cp_type_value, caps.content_protection.cp_type_value_len);
245             break;
246         case AVDTP_HEADER_COMPRESSION:
247             buffer[pos++] = (caps.header_compression.back_ch << 7) | (caps.header_compression.media << 6) | (caps.header_compression.recovery << 5);
248             break;
249         case AVDTP_MULTIPLEXING:
250             buffer[pos++] = caps.multiplexing_mode.fragmentation << 7;
251             for (i=0; i<caps.multiplexing_mode.transport_identifiers_num; i++){
252                 buffer[pos++] = caps.multiplexing_mode.transport_session_identifiers[i] << 7;
253                 buffer[pos++] = caps.multiplexing_mode.tcid[i] << 7;
254                 // media, reporting. recovery
255             }
256             break;
257         case AVDTP_MEDIA_CODEC:
258             buffer[pos++] = ((uint8_t)caps.media_codec.media_type) << 4;
259             buffer[pos++] = (uint8_t)caps.media_codec.media_codec_type;
260             for (i = 0; i<caps.media_codec.media_codec_information_len; i++){
261                 buffer[pos++] = caps.media_codec.media_codec_information[i];
262             }
263             break;
264         default:
265             break;
266     }
267     buffer[0] = pos - 1; // length
268     return pos;
269 }
270 
271 static int avdtp_unpack_service_capabilities_has_errors(avdtp_connection_t * connection, avdtp_service_category_t category, uint8_t cap_len){
272     connection->error_code = 0;
273 
274     if (category == AVDTP_SERVICE_CATEGORY_INVALID_0 ||
275         (category == AVDTP_SERVICE_CATEGORY_INVALID_FF && connection->signaling_packet.signal_identifier == AVDTP_SI_RECONFIGURE)){
276         log_info("    ERROR: BAD SERVICE CATEGORY %d\n", category);
277         connection->reject_service_category = category;
278         connection->error_code = BAD_SERV_CATEGORY;
279         return 1;
280     }
281 
282     if (connection->signaling_packet.signal_identifier == AVDTP_SI_RECONFIGURE){
283         if (category != AVDTP_CONTENT_PROTECTION && category != AVDTP_MEDIA_CODEC){
284             log_info("    ERROR: REJECT CATEGORY, INVALID_CAPABILITIES\n");
285             connection->reject_service_category = category;
286             connection->error_code = INVALID_CAPABILITIES;
287             return 1;
288         }
289     }
290 
291     switch(category){
292         case AVDTP_MEDIA_TRANSPORT:
293             if (cap_len != 0){
294                 log_info("    ERROR: REJECT CATEGORY, BAD_MEDIA_TRANSPORT\n");
295                 connection->reject_service_category = category;
296                 connection->error_code = BAD_MEDIA_TRANSPORT_FORMAT;
297                 return 1;
298             }
299             break;
300         case AVDTP_REPORTING:
301         case AVDTP_DELAY_REPORTING:
302             if (cap_len != 0){
303                 log_info("    ERROR: REJECT CATEGORY, BAD_LENGTH\n");
304                 connection->reject_service_category = category;
305                 connection->error_code = BAD_LENGTH;
306                 return 1;
307             }
308             break;
309         case AVDTP_RECOVERY:
310             if (cap_len < 3){
311                 log_info("    ERROR: REJECT CATEGORY, BAD_MEDIA_TRANSPORT\n");
312                 connection->reject_service_category = category;
313                 connection->error_code = BAD_RECOVERY_FORMAT;
314                 return 1;
315             }
316             break;
317         case AVDTP_CONTENT_PROTECTION:
318             if (cap_len < 2){
319                 log_info("    ERROR: REJECT CATEGORY, BAD_CP_FORMAT\n");
320                 connection->reject_service_category = category;
321                 connection->error_code = BAD_CP_FORMAT;
322                 return 1;
323             }
324             break;
325         case AVDTP_HEADER_COMPRESSION:
326             break;
327         case AVDTP_MULTIPLEXING:
328             break;
329         case AVDTP_MEDIA_CODEC:
330             break;
331         default:
332             break;
333     }
334     return 0;
335 }
336 
337 uint16_t avdtp_unpack_service_capabilities(avdtp_connection_t * connection, avdtp_capabilities_t * caps, uint8_t * packet, uint16_t size){
338     if (size == 0) return 0;
339 
340     uint16_t registered_service_categories = 0;
341     int pos = 0;
342     int i;
343     avdtp_service_category_t category = (avdtp_service_category_t)packet[pos++];
344     uint8_t cap_len = packet[pos++];
345 
346     if (avdtp_unpack_service_capabilities_has_errors(connection, category, cap_len)) return 0;
347     int processed_cap_len = 0;
348     int rfa = 0;
349 
350     while (pos < size){
351         if (cap_len > size - pos){
352             connection->reject_service_category = category;
353             connection->error_code = BAD_LENGTH;
354             return 0;
355         }
356         rfa = 0;
357         processed_cap_len = pos;
358         switch(category){
359             case AVDTP_RECOVERY:
360                 caps->recovery.recovery_type = packet[pos++];
361                 caps->recovery.maximum_recovery_window_size = packet[pos++];
362                 caps->recovery.maximum_number_media_packets = packet[pos++];
363                 break;
364             case AVDTP_CONTENT_PROTECTION:
365                 caps->content_protection.cp_type = big_endian_read_16(packet, pos);
366                 pos+=2;
367 
368                 caps->content_protection.cp_type_value_len = cap_len - 2;
369                 pos += caps->content_protection.cp_type_value_len;
370 
371                 // connection->reject_service_category = category;
372                 // connection->error_code = UNSUPPORTED_CONFIGURATION;
373                 // support for content protection goes here
374                 break;
375 
376             case AVDTP_HEADER_COMPRESSION:
377                 caps->header_compression.back_ch  = packet[pos] >> 7;
378                 caps->header_compression.media    = packet[pos] >> 6;
379                 caps->header_compression.recovery = packet[pos] >> 5;
380                 pos++;
381                 break;
382             case AVDTP_MULTIPLEXING:
383                 caps->multiplexing_mode.fragmentation = packet[pos++] >> 7;
384                 // read [tsid, tcid] for media, reporting. recovery respectively
385                 caps->multiplexing_mode.transport_identifiers_num = 3;
386                 for (i=0; i<caps->multiplexing_mode.transport_identifiers_num; i++){
387                     caps->multiplexing_mode.transport_session_identifiers[i] = packet[pos++] >> 7;
388                     caps->multiplexing_mode.tcid[i] = packet[pos++] >> 7;
389                 }
390                 break;
391             case AVDTP_MEDIA_CODEC:
392                 caps->media_codec.media_type = (avdtp_media_type_t)(packet[pos++] >> 4);
393                 caps->media_codec.media_codec_type = (avdtp_media_codec_type_t)(packet[pos++]);
394                 caps->media_codec.media_codec_information_len = cap_len - 2;
395                 caps->media_codec.media_codec_information = &packet[pos];
396                 pos += caps->media_codec.media_codec_information_len;
397                 break;
398             case AVDTP_MEDIA_TRANSPORT:
399             case AVDTP_REPORTING:
400             case AVDTP_DELAY_REPORTING:
401                 pos += cap_len;
402                 break;
403             default:
404                 pos += cap_len;
405                 rfa = 1;
406                 break;
407         }
408         processed_cap_len = pos - processed_cap_len;
409 
410         if (cap_len == processed_cap_len){
411             if (!rfa) {
412                 registered_service_categories = store_bit16(registered_service_categories, category, 1);
413             }
414             if (pos < size-2){
415                 //int old_pos = pos;
416                 category = (avdtp_service_category_t)packet[pos++];
417                 cap_len = packet[pos++];
418                 if (avdtp_unpack_service_capabilities_has_errors(connection, category, cap_len)) return 0;
419             }
420         }
421     }
422     return registered_service_categories;
423 }
424 
425 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){
426     if (signaling_packet->offset) return;
427     uint8_t pack_all_capabilities = 1;
428     signaling_packet->message_type = AVDTP_RESPONSE_ACCEPT_MSG;
429     int i;
430 
431     signaling_packet->size = 0;
432     memset(signaling_packet->command, 0 , sizeof(signaling_packet->command));
433 
434 
435     switch (identifier) {
436         case AVDTP_SI_GET_CAPABILITIES:
437             pack_all_capabilities = 0;
438             break;
439         case AVDTP_SI_GET_ALL_CAPABILITIES:
440             pack_all_capabilities = 1;
441             break;
442         case AVDTP_SI_SET_CONFIGURATION:
443             signaling_packet->command[signaling_packet->size++] = signaling_packet->acp_seid << 2;
444             signaling_packet->command[signaling_packet->size++] = signaling_packet->int_seid << 2;
445             signaling_packet->message_type = AVDTP_CMD_MSG;
446             break;
447         case AVDTP_SI_RECONFIGURE:
448             signaling_packet->command[signaling_packet->size++] = signaling_packet->acp_seid << 2;
449             signaling_packet->message_type = AVDTP_CMD_MSG;
450             break;
451         default:
452             log_error("avdtp_prepare_capabilities wrong identifier %d", identifier);
453             break;
454     }
455 
456     for (i = 1; i < 9; i++){
457         int registered_category = get_bit16(registered_service_categories, i);
458         if (!registered_category && (identifier == AVDTP_SI_SET_CONFIGURATION || identifier == AVDTP_SI_RECONFIGURE)){
459             // TODO: introduce bitmap of mandatory categories
460             if (i == 1){
461                 registered_category = 1;
462             }
463         }
464         if (registered_category){
465             // service category
466             signaling_packet->command[signaling_packet->size++] = i;
467             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);
468         }
469     }
470 
471     signaling_packet->signal_identifier = (avdtp_signal_identifier_t)identifier;
472     signaling_packet->transaction_label = transaction_label;
473 }
474 
475 int avdtp_signaling_create_fragment(uint16_t cid, avdtp_signaling_packet_t * signaling_packet, uint8_t * out_buffer) {
476     int mtu = l2cap_get_remote_mtu_for_local_cid(cid);
477     int data_len = 0;
478 
479     uint16_t offset = signaling_packet->offset;
480     uint16_t pos = 1;
481 
482     if (offset == 0){
483         if (signaling_packet->size <= mtu - 2){
484             signaling_packet->packet_type = AVDTP_SINGLE_PACKET;
485             out_buffer[pos++] = signaling_packet->signal_identifier;
486             data_len = signaling_packet->size;
487         } else {
488             signaling_packet->packet_type = AVDTP_START_PACKET;
489             out_buffer[pos++] = (mtu + signaling_packet->size)/ (mtu-1);
490             out_buffer[pos++] = signaling_packet->signal_identifier;
491             data_len = mtu - 3;
492             signaling_packet->offset = data_len;
493         }
494     } else {
495         int remaining_bytes = signaling_packet->size - offset;
496         if (remaining_bytes <= mtu - 1){
497             signaling_packet->packet_type = AVDTP_END_PACKET;
498             data_len = remaining_bytes;
499             signaling_packet->offset = 0;
500         } else{
501             signaling_packet->packet_type = AVDTP_CONTINUE_PACKET;
502             data_len = mtu - 1;
503             signaling_packet->offset += data_len;
504         }
505     }
506     out_buffer[0] = avdtp_header(signaling_packet->transaction_label, signaling_packet->packet_type, signaling_packet->message_type);
507     memcpy(out_buffer+pos, signaling_packet->command + offset, data_len);
508     pos += data_len;
509     return pos;
510 }
511 
512 
513 void avdtp_signaling_emit_connection_established(btstack_packet_handler_t callback, uint16_t avdtp_cid, bd_addr_t addr, uint8_t status){
514     if (!callback) return;
515     uint8_t event[12];
516     int pos = 0;
517     event[pos++] = HCI_EVENT_AVDTP_META;
518     event[pos++] = sizeof(event) - 2;
519     event[pos++] = AVDTP_SUBEVENT_SIGNALING_CONNECTION_ESTABLISHED;
520     little_endian_store_16(event, pos, avdtp_cid);
521     pos += 2;
522     reverse_bd_addr(addr,&event[pos]);
523     pos += 6;
524     event[pos++] = status;
525     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
526 }
527 
528 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){
529     if (!callback) return;
530     uint8_t event[8];
531     int pos = 0;
532     event[pos++] = HCI_EVENT_AVDTP_META;
533     event[pos++] = sizeof(event) - 2;
534     event[pos++] = AVDTP_SUBEVENT_STREAMING_CAN_SEND_MEDIA_PACKET_NOW;
535     little_endian_store_16(event, pos, avdtp_cid);
536     pos += 2;
537     event[pos++] = seid;
538     little_endian_store_16(event, pos, sequence_number);
539     pos += 2;
540     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
541 }
542 
543 void avdtp_signaling_emit_connection_released(btstack_packet_handler_t callback, uint16_t avdtp_cid){
544     if (!callback) return;
545     uint8_t event[5];
546     int pos = 0;
547     event[pos++] = HCI_EVENT_AVDTP_META;
548     event[pos++] = sizeof(event) - 2;
549     event[pos++] = AVDTP_SUBEVENT_SIGNALING_CONNECTION_RELEASED;
550     little_endian_store_16(event, pos, avdtp_cid);
551     pos += 2;
552     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
553 }
554 
555 void avdtp_streaming_emit_connection_released(btstack_packet_handler_t callback, uint16_t avdtp_cid, uint8_t local_seid){
556     if (!callback) return;
557     uint8_t event[6];
558     int pos = 0;
559     event[pos++] = HCI_EVENT_AVDTP_META;
560     event[pos++] = sizeof(event) - 2;
561     event[pos++] = AVDTP_SUBEVENT_STREAMING_CONNECTION_RELEASED;
562     little_endian_store_16(event, pos, avdtp_cid);
563     pos += 2;
564     event[pos++] = local_seid;
565     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
566 }
567 
568 void avdtp_streaming_emit_connection_established(btstack_packet_handler_t callback, uint16_t avdtp_cid, uint8_t local_seid, uint8_t remote_seid, uint8_t status){
569     if (!callback) return;
570     uint8_t event[8];
571     int pos = 0;
572     event[pos++] = HCI_EVENT_AVDTP_META;
573     event[pos++] = sizeof(event) - 2;
574     event[pos++] = AVDTP_SUBEVENT_STREAMING_CONNECTION_ESTABLISHED;
575     little_endian_store_16(event, pos, avdtp_cid);
576     pos += 2;
577     event[pos++] = local_seid;
578     event[pos++] = remote_seid;
579     event[pos++] = status;
580     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
581 }
582 
583 void avdtp_signaling_emit_sep(btstack_packet_handler_t callback, uint16_t avdtp_cid, avdtp_sep_t sep){
584     if (!callback) return;
585     uint8_t event[9];
586     int pos = 0;
587     event[pos++] = HCI_EVENT_AVDTP_META;
588     event[pos++] = sizeof(event) - 2;
589     event[pos++] = AVDTP_SUBEVENT_SIGNALING_SEP_FOUND;
590     little_endian_store_16(event, pos, avdtp_cid);
591     pos += 2;
592     event[pos++] = sep.seid;
593     event[pos++] = sep.in_use;
594     event[pos++] = sep.media_type;
595     event[pos++] = sep.type;
596     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
597 }
598 
599 void avdtp_signaling_emit_accept(btstack_packet_handler_t callback, uint16_t avdtp_cid, uint8_t local_seid, avdtp_signal_identifier_t identifier){
600     if (!callback) return;
601     uint8_t event[7];
602     int pos = 0;
603     event[pos++] = HCI_EVENT_AVDTP_META;
604     event[pos++] = sizeof(event) - 2;
605     event[pos++] = AVDTP_SUBEVENT_SIGNALING_ACCEPT;
606     little_endian_store_16(event, pos, avdtp_cid);
607     pos += 2;
608     event[pos++] = local_seid;
609     event[pos++] = identifier;
610     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
611 }
612 
613 void avdtp_signaling_emit_reject(btstack_packet_handler_t callback, uint16_t avdtp_cid, uint8_t local_seid, avdtp_signal_identifier_t identifier){
614     if (!callback) return;
615     uint8_t event[7];
616     int pos = 0;
617     event[pos++] = HCI_EVENT_AVDTP_META;
618     event[pos++] = sizeof(event) - 2;
619     event[pos++] = AVDTP_SUBEVENT_SIGNALING_REJECT;
620     little_endian_store_16(event, pos, avdtp_cid);
621     pos += 2;
622     event[pos++] = local_seid;
623     event[pos++] = identifier;
624     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
625 }
626 
627 void avdtp_signaling_emit_general_reject(btstack_packet_handler_t callback, uint16_t avdtp_cid, uint8_t local_seid, avdtp_signal_identifier_t identifier){
628     if (!callback) return;
629     uint8_t event[7];
630     int pos = 0;
631     event[pos++] = HCI_EVENT_AVDTP_META;
632     event[pos++] = sizeof(event) - 2;
633     event[pos++] = AVDTP_SUBEVENT_SIGNALING_GENERAL_REJECT;
634     little_endian_store_16(event, pos, avdtp_cid);
635     pos += 2;
636     event[pos++] = local_seid;
637     event[pos++] = identifier;
638     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
639 }
640 
641 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){
642     if (!callback) return;
643     uint8_t event[15];
644     int pos = 0;
645     event[pos++] = HCI_EVENT_AVDTP_META;
646     event[pos++] = sizeof(event) - 2;
647     event[pos++] = AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_SBC_CAPABILITY;
648     little_endian_store_16(event, pos, avdtp_cid);
649     pos += 2;
650     event[pos++] = local_seid;
651     event[pos++] = remote_seid;
652     event[pos++] = media_codec.media_type;
653     event[pos++] = media_codec.media_codec_information[0] >> 4;
654     event[pos++] = media_codec.media_codec_information[0] & 0x0F;
655     event[pos++] = media_codec.media_codec_information[1] >> 4;
656     event[pos++] = (media_codec.media_codec_information[1] & 0x0F) >> 2;
657     event[pos++] = media_codec.media_codec_information[1] & 0x03;
658     event[pos++] = media_codec.media_codec_information[2];
659     event[pos++] = media_codec.media_codec_information[3];
660     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
661 }
662 
663 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){
664     if (!callback) return;
665         uint8_t event[111];
666     int pos = 0;
667     event[pos++] = HCI_EVENT_AVDTP_META;
668     event[pos++] = sizeof(event) - 2;
669     event[pos++] = AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_OTHER_CAPABILITY;
670     little_endian_store_16(event, pos, avdtp_cid);
671     pos += 2;
672     event[pos++] = local_seid;
673     event[pos++] = remote_seid;
674     event[pos++] = media_codec.media_type;
675     little_endian_store_16(event, pos, media_codec.media_codec_type);
676     pos += 2;
677     little_endian_store_16(event, pos, media_codec.media_codec_information_len);
678     pos += 2;
679     if (media_codec.media_codec_information_len < 100){
680         memcpy(event+pos, media_codec.media_codec_information, media_codec.media_codec_information_len);
681     } else {
682         memcpy(event+pos, media_codec.media_codec_information, 100);
683     }
684     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
685 }
686 
687 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, adtvp_media_codec_capabilities_t media_codec, uint8_t reconfigure){
688     if (!callback) return;
689     uint8_t event[16+2];
690     int pos = 0;
691     event[pos++] = HCI_EVENT_AVDTP_META;
692     event[pos++] = sizeof(event) - 2;
693 
694     event[pos++] = AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_SBC_CONFIGURATION;
695     little_endian_store_16(event, pos, avdtp_cid);
696     pos += 2;
697     event[pos++] = local_seid;
698     event[pos++] = remote_seid;
699     event[pos++] = reconfigure;
700 
701     uint8_t num_channels = 0;
702     uint16_t sampling_frequency = 0;
703     uint8_t subbands = 0;
704     uint8_t block_length = 0;
705 
706     uint8_t sampling_frequency_bitmap = media_codec.media_codec_information[0] >> 4;
707     uint8_t channel_mode_bitmap = media_codec.media_codec_information[0] & 0x0F;
708     uint8_t block_length_bitmap = media_codec.media_codec_information[1] >> 4;
709     uint8_t subbands_bitmap = (media_codec.media_codec_information[1] & 0x0F) >> 2;
710 
711     if (channel_mode_bitmap & AVDTP_SBC_MONO){
712         num_channels = 1;
713     }
714     if ( (channel_mode_bitmap & AVDTP_SBC_JOINT_STEREO) ||
715          (channel_mode_bitmap & AVDTP_SBC_STEREO) ||
716          (channel_mode_bitmap & AVDTP_SBC_DUAL_CHANNEL) ){
717         num_channels = 2;
718     }
719 
720     if (sampling_frequency_bitmap & AVDTP_SBC_16000){
721         sampling_frequency = 16000;
722     }
723     if (sampling_frequency_bitmap & AVDTP_SBC_32000){
724         sampling_frequency = 32000;
725     }
726     if (sampling_frequency_bitmap & AVDTP_SBC_44100){
727         sampling_frequency = 44100;
728     }
729     if (sampling_frequency_bitmap & AVDTP_SBC_48000){
730         sampling_frequency = 48000;
731     }
732 
733     if (subbands_bitmap & AVDTP_SBC_SUBBANDS_4){
734         subbands = 4;
735     }
736     if (subbands_bitmap & AVDTP_SBC_SUBBANDS_8){
737         subbands = 8;
738     }
739 
740     if (block_length_bitmap & AVDTP_SBC_BLOCK_LENGTH_4){
741         block_length = 4;
742     }
743     if (block_length_bitmap & AVDTP_SBC_BLOCK_LENGTH_8){
744         block_length = 8;
745     }
746     if (block_length_bitmap & AVDTP_SBC_BLOCK_LENGTH_12){
747         block_length = 12;
748     }
749     if (block_length_bitmap & AVDTP_SBC_BLOCK_LENGTH_16){
750         block_length = 16;
751     }
752 
753     event[pos++] = media_codec.media_type;
754     little_endian_store_16(event, pos, sampling_frequency);
755     pos += 2;
756 
757     event[pos++] = channel_mode_bitmap;
758     event[pos++] = num_channels;
759     event[pos++] = block_length;
760     event[pos++] = subbands;
761     event[pos++] = media_codec.media_codec_information[1] & 0x03;
762     event[pos++] = media_codec.media_codec_information[2];
763     event[pos++] = media_codec.media_codec_information[3];
764     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
765 }
766 
767 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, adtvp_media_codec_capabilities_t media_codec){
768     if (!callback) return;
769     avdtp_signaling_emit_media_codec_sbc(callback, avdtp_cid, local_seid, remote_seid, media_codec, 0);
770 }
771 
772 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, adtvp_media_codec_capabilities_t media_codec){
773     if (!callback) return;
774     avdtp_signaling_emit_media_codec_sbc(callback, avdtp_cid, local_seid, remote_seid, media_codec, 1);
775 }
776 
777 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){
778     uint8_t event[MAX_MEDIA_CODEC_INFORMATION_LENGTH + 13];
779     int pos = 0;
780     event[pos++] = HCI_EVENT_AVDTP_META;
781     event[pos++] = sizeof(event) - 2;
782     event[pos++] = AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_OTHER_CONFIGURATION;
783     little_endian_store_16(event, pos, avdtp_cid);
784     pos += 2;
785     event[pos++] = local_seid;
786     event[pos++] = remote_seid;
787     event[pos++] = reconfigure;
788     event[pos++] = media_codec.media_type;
789     little_endian_store_16(event, pos, media_codec.media_codec_type);
790     pos += 2;
791     little_endian_store_16(event, pos, media_codec.media_codec_information_len);
792     pos += 2;
793 
794     int media_codec_len = btstack_min(MAX_MEDIA_CODEC_INFORMATION_LENGTH, media_codec.media_codec_information_len);
795     memcpy(event+pos, media_codec.media_codec_information, media_codec_len);
796 
797     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
798 }
799 
800 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){
801     if (!callback) return;
802     avdtp_signaling_emit_media_codec_other(callback, avdtp_cid, local_seid, remote_seid, media_codec, 0);
803 }
804 
805 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){
806     if (!callback) return;
807     avdtp_signaling_emit_media_codec_other(callback, avdtp_cid, local_seid, remote_seid, media_codec, 1);
808 }
809 
810 
811 void avdtp_request_can_send_now_acceptor(avdtp_connection_t * connection, uint16_t l2cap_cid){
812     connection->wait_to_send_acceptor = 1;
813     l2cap_request_can_send_now_event(l2cap_cid);
814 }
815 void avdtp_request_can_send_now_initiator(avdtp_connection_t * connection, uint16_t l2cap_cid){
816     connection->wait_to_send_initiator = 1;
817     l2cap_request_can_send_now_event(l2cap_cid);
818 }
819 void avdtp_request_can_send_now_self(avdtp_connection_t * connection, uint16_t l2cap_cid){
820     connection->wait_to_send_self = 1;
821     l2cap_request_can_send_now_event(l2cap_cid);
822 }
823 
824 uint8_t avdtp_get_index_of_remote_stream_endpoint_with_seid(avdtp_stream_endpoint_t * stream_endpoint, uint16_t seid){
825     if (!stream_endpoint->connection) return AVDTP_INVALID_SEP_INDEX;
826     if (stream_endpoint->connection->remote_seps[stream_endpoint->remote_sep_index].seid == seid){
827         return stream_endpoint->remote_sep_index;
828     }
829     int i;
830     for (i=0; i < stream_endpoint->connection->remote_seps_num; i++){
831         if (stream_endpoint->connection->remote_seps[i].seid == seid){
832             return i;
833         }
834     }
835     return AVDTP_INVALID_SEP_INDEX;
836 }
837 
838 uint8_t avdtp_find_remote_sep(avdtp_connection_t * connection, uint8_t remote_seid){
839     if (!connection) return AVDTP_INVALID_SEP_INDEX;
840     int i;
841     for (i = 0; i < connection->remote_seps_num; i++){
842         if (connection->remote_seps[i].seid == remote_seid){
843             return i;
844         }
845     }
846     return AVDTP_INVALID_SEP_INDEX;
847 }
848 
849 
850 uint8_t avdtp_local_seid(avdtp_stream_endpoint_t * stream_endpoint){
851     if (!stream_endpoint) return 0;
852     return stream_endpoint->sep.seid;
853 
854 }
855 
856 uint8_t avdtp_remote_seid(avdtp_stream_endpoint_t * stream_endpoint){
857     if (!stream_endpoint) return 0;
858     if (!stream_endpoint->connection) return 0;
859     return stream_endpoint->connection->remote_seps[stream_endpoint->remote_sep_index].seid;
860 }
861