xref: /btstack/src/classic/avdtp_util.c (revision dbe92de6a93924b91532f8d818af55adf6b370d8)
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 int get_bit16(uint16_t bitmap, int position){
100     return (bitmap >> position) & 1;
101 }
102 
103 uint16_t store_bit16(uint16_t bitmap, int position, uint8_t value){
104     if (value){
105         bitmap |= 1 << position;
106     } else {
107         bitmap &= ~ (1 << position);
108     }
109     return bitmap;
110 }
111 
112 avdtp_message_type_t avdtp_get_signaling_packet_type(uint8_t * packet){
113     return (avdtp_message_type_t) (packet[0] & 0x03);
114 }
115 
116 int avdtp_read_signaling_header(avdtp_signaling_packet_t * signaling_header, uint8_t * packet, uint16_t size){
117     int pos = 0;
118     if (size < 2) return pos;
119     signaling_header->transaction_label = packet[pos] >> 4;
120     signaling_header->packet_type = (avdtp_packet_type_t)((packet[pos] >> 2) & 0x03);
121     signaling_header->message_type = (avdtp_message_type_t) (packet[pos] & 0x03);
122     pos++;
123     memset(signaling_header->command, 0, sizeof(signaling_header->command));
124     switch (signaling_header->packet_type){
125         case AVDTP_SINGLE_PACKET:
126             signaling_header->num_packets = 0;
127             signaling_header->offset = 0;
128             signaling_header->size = 0;
129             break;
130         case AVDTP_END_PACKET:
131             signaling_header->num_packets = 0;
132             break;
133         case AVDTP_START_PACKET:
134             signaling_header->num_packets = packet[pos++];
135             signaling_header->size = 0;
136             signaling_header->offset = 0;
137             break;
138         case AVDTP_CONTINUE_PACKET:
139             if (signaling_header->num_packets <= 0) {
140                 log_info("    ERROR: wrong num fragmented packets\n");
141                 break;
142             }
143             signaling_header->num_packets--;
144             break;
145     }
146     signaling_header->signal_identifier = (avdtp_signal_identifier_t)(packet[pos++] & 0x3f);
147     return pos;
148 }
149 
150 int avdtp_pack_service_capabilities(uint8_t * buffer, int size, avdtp_capabilities_t caps, avdtp_service_category_t category, uint8_t pack_all_capabilities){
151     UNUSED(size);
152 
153     int i;
154     // pos = 0 reserved for length
155     int pos = 1;
156     switch(category){
157         case AVDTP_MEDIA_TRANSPORT:
158         case AVDTP_REPORTING:
159             break;
160         case AVDTP_DELAY_REPORTING:
161             if (!pack_all_capabilities) break;
162             break;
163         case AVDTP_RECOVERY:
164             buffer[pos++] = caps.recovery.recovery_type; // 0x01=RFC2733
165             buffer[pos++] = caps.recovery.maximum_recovery_window_size;
166             buffer[pos++] = caps.recovery.maximum_number_media_packets;
167             break;
168         case AVDTP_CONTENT_PROTECTION:
169             buffer[pos++] = caps.content_protection.cp_type_value_len + 2;
170             big_endian_store_16(buffer, pos, caps.content_protection.cp_type);
171             pos += 2;
172             (void)memcpy(buffer + pos, caps.content_protection.cp_type_value,
173                          caps.content_protection.cp_type_value_len);
174             break;
175         case AVDTP_HEADER_COMPRESSION:
176             buffer[pos++] = (caps.header_compression.back_ch << 7) | (caps.header_compression.media << 6) | (caps.header_compression.recovery << 5);
177             break;
178         case AVDTP_MULTIPLEXING:
179             buffer[pos++] = caps.multiplexing_mode.fragmentation << 7;
180             for (i=0; i<caps.multiplexing_mode.transport_identifiers_num; i++){
181                 buffer[pos++] = caps.multiplexing_mode.transport_session_identifiers[i] << 7;
182                 buffer[pos++] = caps.multiplexing_mode.tcid[i] << 7;
183                 // media, reporting. recovery
184             }
185             break;
186         case AVDTP_MEDIA_CODEC:
187             buffer[pos++] = ((uint8_t)caps.media_codec.media_type) << 4;
188             buffer[pos++] = (uint8_t)caps.media_codec.media_codec_type;
189             for (i = 0; i<caps.media_codec.media_codec_information_len; i++){
190                 buffer[pos++] = caps.media_codec.media_codec_information[i];
191             }
192             break;
193         default:
194             break;
195     }
196     buffer[0] = pos - 1; // length
197     return pos;
198 }
199 
200 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){
201     connection->error_code = 0;
202 
203     if ((category == AVDTP_SERVICE_CATEGORY_INVALID_0) ||
204         ((category == AVDTP_SERVICE_CATEGORY_INVALID_FF) && (signal_identifier == AVDTP_SI_RECONFIGURE))){
205         log_info("    ERROR: BAD SERVICE CATEGORY %d\n", category);
206         connection->reject_service_category = category;
207         connection->error_code = BAD_SERV_CATEGORY;
208         return 1;
209     }
210 
211     if (signal_identifier == AVDTP_SI_RECONFIGURE){
212         if ( (category != AVDTP_CONTENT_PROTECTION) && (category != AVDTP_MEDIA_CODEC)){
213             log_info("    ERROR: REJECT CATEGORY, INVALID_CAPABILITIES\n");
214             connection->reject_service_category = category;
215             connection->error_code = INVALID_CAPABILITIES;
216             return 1;
217         }
218     }
219 
220     switch(category){
221         case AVDTP_MEDIA_TRANSPORT:
222             if (cap_len != 0){
223                 log_info("    ERROR: REJECT CATEGORY, BAD_MEDIA_TRANSPORT\n");
224                 connection->reject_service_category = category;
225                 connection->error_code = BAD_MEDIA_TRANSPORT_FORMAT;
226                 return 1;
227             }
228             break;
229         case AVDTP_REPORTING:
230         case AVDTP_DELAY_REPORTING:
231             if (cap_len != 0){
232                 log_info("    ERROR: REJECT CATEGORY, BAD_LENGTH\n");
233                 connection->reject_service_category = category;
234                 connection->error_code = BAD_LENGTH;
235                 return 1;
236             }
237             break;
238         case AVDTP_RECOVERY:
239             if (cap_len != 3){
240                 log_info("    ERROR: REJECT CATEGORY, BAD_MEDIA_TRANSPORT\n");
241                 connection->reject_service_category = category;
242                 connection->error_code = BAD_RECOVERY_FORMAT;
243                 return 1;
244             }
245             break;
246         case AVDTP_CONTENT_PROTECTION:
247             if (cap_len < 2){
248                 log_info("    ERROR: REJECT CATEGORY, BAD_CP_FORMAT\n");
249                 connection->reject_service_category = category;
250                 connection->error_code = BAD_CP_FORMAT;
251                 return 1;
252             }
253             break;
254         case AVDTP_HEADER_COMPRESSION:
255             // TODO: find error code for bad header compression
256             if (cap_len != 1){
257                 log_info("    ERROR: REJECT CATEGORY, BAD_HEADER_COMPRESSION\n");
258                 connection->reject_service_category = category;
259                 connection->error_code = BAD_RECOVERY_FORMAT;
260                 return 1;
261             }
262             break;
263         case AVDTP_MULTIPLEXING:
264             break;
265         case AVDTP_MEDIA_CODEC:
266             break;
267         default:
268             break;
269     }
270     return 0;
271 }
272 
273 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){
274 
275     int i;
276 
277     uint16_t registered_service_categories = 0;
278     uint16_t to_process = size;
279 
280     while (to_process >= 2){
281 
282         avdtp_service_category_t category = (avdtp_service_category_t) packet[0];
283         uint8_t cap_len = packet[1];
284         packet     += 2;
285         to_process -= 2;
286 
287         if (cap_len > to_process){
288             connection->reject_service_category = category;
289             connection->error_code = BAD_LENGTH;
290             return 0;
291         }
292 
293         if (avdtp_unpack_service_capabilities_has_errors(connection, signal_identifier, category, cap_len)) return 0;
294 
295         int category_valid = 1;
296 
297         uint8_t * data = packet;
298         uint16_t  pos = 0;
299 
300         switch(category){
301             case AVDTP_RECOVERY:
302                 caps->recovery.recovery_type = data[pos++];
303                 caps->recovery.maximum_recovery_window_size = data[pos++];
304                 caps->recovery.maximum_number_media_packets = data[pos++];
305                 break;
306             case AVDTP_CONTENT_PROTECTION:
307                 caps->content_protection.cp_type = big_endian_read_16(data, 0);
308                 caps->content_protection.cp_type_value_len = cap_len - 2;
309                 // connection->reject_service_category = category;
310                 // connection->error_code = UNSUPPORTED_CONFIGURATION;
311                 // support for content protection goes here
312                 break;
313             case AVDTP_HEADER_COMPRESSION:
314                 caps->header_compression.back_ch  = (data[0] >> 7) & 1;
315                 caps->header_compression.media    = (data[0] >> 6) & 1;
316                 caps->header_compression.recovery = (data[0] >> 5) & 1;
317                 break;
318             case AVDTP_MULTIPLEXING:
319                 caps->multiplexing_mode.fragmentation = (data[pos++] >> 7) & 1;
320                 // read [tsid, tcid] for media, reporting. recovery respectively
321                 caps->multiplexing_mode.transport_identifiers_num = 3;
322                 for (i=0; i<caps->multiplexing_mode.transport_identifiers_num; i++){
323                     caps->multiplexing_mode.transport_session_identifiers[i] = (data[pos++] >> 7) & 1;
324                     caps->multiplexing_mode.tcid[i] = (data[pos++] >> 7) & 1;
325                 }
326                 break;
327             case AVDTP_MEDIA_CODEC:
328                 caps->media_codec.media_type = (avdtp_media_type_t)(data[pos++] >> 4);
329                 caps->media_codec.media_codec_type = (avdtp_media_codec_type_t)(data[pos++]);
330                 caps->media_codec.media_codec_information_len = cap_len - 2;
331                 caps->media_codec.media_codec_information = &data[pos++];
332                 break;
333             case AVDTP_MEDIA_TRANSPORT:
334             case AVDTP_REPORTING:
335             case AVDTP_DELAY_REPORTING:
336                 break;
337             default:
338                 category_valid = 0;
339                 break;
340         }
341 
342         if (category_valid) {
343             registered_service_categories = store_bit16(registered_service_categories, category, 1);
344         }
345 
346         packet     += cap_len;
347         to_process -= cap_len;
348     }
349 
350     return registered_service_categories;
351 }
352 
353 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){
354     if (signaling_packet->offset) return;
355     uint8_t pack_all_capabilities = 1;
356     signaling_packet->message_type = AVDTP_RESPONSE_ACCEPT_MSG;
357     int i;
358 
359     signaling_packet->size = 0;
360     memset(signaling_packet->command, 0 , sizeof(signaling_packet->command));
361 
362 
363     switch (identifier) {
364         case AVDTP_SI_GET_CAPABILITIES:
365             pack_all_capabilities = 0;
366             break;
367         case AVDTP_SI_GET_ALL_CAPABILITIES:
368             pack_all_capabilities = 1;
369             break;
370         case AVDTP_SI_SET_CONFIGURATION:
371             signaling_packet->command[signaling_packet->size++] = signaling_packet->acp_seid << 2;
372             signaling_packet->command[signaling_packet->size++] = signaling_packet->int_seid << 2;
373             signaling_packet->message_type = AVDTP_CMD_MSG;
374             break;
375         case AVDTP_SI_RECONFIGURE:
376             signaling_packet->command[signaling_packet->size++] = signaling_packet->acp_seid << 2;
377             signaling_packet->message_type = AVDTP_CMD_MSG;
378             break;
379         default:
380             log_error("avdtp_prepare_capabilities wrong identifier %d", identifier);
381             break;
382     }
383 
384     for (i = 1; i < 9; i++){
385         int registered_category = get_bit16(registered_service_categories, i);
386         if (!registered_category && (identifier == AVDTP_SI_SET_CONFIGURATION)){
387             // TODO: introduce bitmap of mandatory categories
388             if (i == 1){
389                 registered_category = 1;
390             }
391         }
392         if (registered_category){
393             // service category
394             signaling_packet->command[signaling_packet->size++] = i;
395             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);
396         }
397     }
398     signaling_packet->signal_identifier = (avdtp_signal_identifier_t)identifier;
399     signaling_packet->transaction_label = transaction_label;
400 }
401 
402 int avdtp_signaling_create_fragment(uint16_t cid, avdtp_signaling_packet_t * signaling_packet, uint8_t * out_buffer) {
403     int mtu = l2cap_get_remote_mtu_for_local_cid(cid);
404     int data_len = 0;
405 
406     uint16_t offset = signaling_packet->offset;
407     uint16_t pos = 1;
408 
409     if (offset == 0){
410         if (signaling_packet->size <= (mtu - 2)){
411             signaling_packet->packet_type = AVDTP_SINGLE_PACKET;
412             out_buffer[pos++] = signaling_packet->signal_identifier;
413             data_len = signaling_packet->size;
414         } else {
415             signaling_packet->packet_type = AVDTP_START_PACKET;
416             out_buffer[pos++] = (mtu + signaling_packet->size)/ (mtu-1);
417             out_buffer[pos++] = signaling_packet->signal_identifier;
418             data_len = mtu - 3;
419             signaling_packet->offset = data_len;
420         }
421     } else {
422         int remaining_bytes = signaling_packet->size - offset;
423         if (remaining_bytes <= (mtu - 1)){
424             signaling_packet->packet_type = AVDTP_END_PACKET;
425             data_len = remaining_bytes;
426             signaling_packet->offset = 0;
427         } else{
428             signaling_packet->packet_type = AVDTP_CONTINUE_PACKET;
429             data_len = mtu - 1;
430             signaling_packet->offset += data_len;
431         }
432     }
433     out_buffer[0] = avdtp_header(signaling_packet->transaction_label, signaling_packet->packet_type, signaling_packet->message_type);
434     (void)memcpy(out_buffer + pos, signaling_packet->command + offset,
435                  data_len);
436     pos += data_len;
437     return pos;
438 }
439 
440 
441 void avdtp_signaling_emit_connection_established(uint16_t avdtp_cid, bd_addr_t addr, uint8_t status) {
442     uint8_t event[12];
443     int pos = 0;
444     event[pos++] = HCI_EVENT_AVDTP_META;
445     event[pos++] = sizeof(event) - 2;
446     event[pos++] = AVDTP_SUBEVENT_SIGNALING_CONNECTION_ESTABLISHED;
447     little_endian_store_16(event, pos, avdtp_cid);
448     pos += 2;
449     reverse_bd_addr(addr,&event[pos]);
450     pos += 6;
451     event[pos++] = status;
452     avdtp_emit_sink_and_source(event, pos);
453 }
454 
455 void avdtp_signaling_emit_connection_released(uint16_t avdtp_cid) {
456     uint8_t event[5];
457     int pos = 0;
458     event[pos++] = HCI_EVENT_AVDTP_META;
459     event[pos++] = sizeof(event) - 2;
460     event[pos++] = AVDTP_SUBEVENT_SIGNALING_CONNECTION_RELEASED;
461     little_endian_store_16(event, pos, avdtp_cid);
462     pos += 2;
463     avdtp_emit_sink_and_source(event, pos);
464 }
465 
466 void avdtp_signaling_emit_sep(uint16_t avdtp_cid, avdtp_sep_t sep) {
467     uint8_t event[9];
468     int pos = 0;
469     event[pos++] = HCI_EVENT_AVDTP_META;
470     event[pos++] = sizeof(event) - 2;
471     event[pos++] = AVDTP_SUBEVENT_SIGNALING_SEP_FOUND;
472     little_endian_store_16(event, pos, avdtp_cid);
473     pos += 2;
474     event[pos++] = sep.seid;
475     event[pos++] = sep.in_use;
476     event[pos++] = sep.media_type;
477     event[pos++] = sep.type;
478     avdtp_emit_sink_and_source(event, pos);
479 }
480 
481 void avdtp_signaling_emit_sep_done(uint16_t avdtp_cid) {
482     uint8_t event[5];
483     int pos = 0;
484     event[pos++] = HCI_EVENT_AVDTP_META;
485     event[pos++] = sizeof(event) - 2;
486     event[pos++] = AVDTP_SUBEVENT_SIGNALING_SEP_DICOVERY_DONE;
487     little_endian_store_16(event, pos, avdtp_cid);
488     pos += 2;
489     avdtp_emit_sink_and_source(event, pos);
490 }
491 
492 void avdtp_signaling_emit_accept(uint16_t avdtp_cid, uint8_t local_seid, avdtp_signal_identifier_t identifier, bool is_initiator) {
493     uint8_t event[8];
494     int pos = 0;
495     event[pos++] = HCI_EVENT_AVDTP_META;
496     event[pos++] = sizeof(event) - 2;
497     event[pos++] = AVDTP_SUBEVENT_SIGNALING_ACCEPT;
498     little_endian_store_16(event, pos, avdtp_cid);
499     pos += 2;
500     event[pos++] = local_seid;
501     event[pos++] = is_initiator ? 1 : 0;
502     event[pos++] = identifier;
503     avdtp_emit_sink_and_source(event, pos);
504 }
505 
506 void avdtp_signaling_emit_reject(uint16_t avdtp_cid, uint8_t local_seid, avdtp_signal_identifier_t identifier, bool is_initiator) {
507     uint8_t event[8];
508     int pos = 0;
509     event[pos++] = HCI_EVENT_AVDTP_META;
510     event[pos++] = sizeof(event) - 2;
511     event[pos++] = AVDTP_SUBEVENT_SIGNALING_REJECT;
512     little_endian_store_16(event, pos, avdtp_cid);
513     pos += 2;
514     event[pos++] = local_seid;
515     event[pos++] = is_initiator ? 1 : 0;
516     event[pos++] = identifier;
517     avdtp_emit_sink_and_source(event, pos);
518 }
519 
520 void avdtp_signaling_emit_general_reject(uint16_t avdtp_cid, uint8_t local_seid, avdtp_signal_identifier_t identifier, bool is_initiator) {
521     uint8_t event[8];
522     int pos = 0;
523     event[pos++] = HCI_EVENT_AVDTP_META;
524     event[pos++] = sizeof(event) - 2;
525     event[pos++] = AVDTP_SUBEVENT_SIGNALING_GENERAL_REJECT;
526     little_endian_store_16(event, pos, avdtp_cid);
527     pos += 2;
528     event[pos++] = local_seid;
529     event[pos++] = is_initiator ? 1 : 0;
530     event[pos++] = identifier;
531     avdtp_emit_sink_and_source(event, pos);
532 }
533 
534 static void avdtp_signaling_emit_media_codec_sbc_capability(uint16_t avdtp_cid, uint8_t local_seid, uint8_t remote_seid,
535                                                             adtvp_media_codec_capabilities_t media_codec) {
536     uint8_t event[15];
537     int pos = 0;
538     event[pos++] = HCI_EVENT_AVDTP_META;
539     event[pos++] = sizeof(event) - 2;
540     event[pos++] = AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_SBC_CAPABILITY;
541     little_endian_store_16(event, pos, avdtp_cid);
542     pos += 2;
543     event[pos++] = local_seid;
544     event[pos++] = remote_seid;
545     event[pos++] = media_codec.media_type;
546     event[pos++] = media_codec.media_codec_information[0] >> 4;
547     event[pos++] = media_codec.media_codec_information[0] & 0x0F;
548     event[pos++] = media_codec.media_codec_information[1] >> 4;
549     event[pos++] = (media_codec.media_codec_information[1] & 0x0F) >> 2;
550     event[pos++] = media_codec.media_codec_information[1] & 0x03;
551     event[pos++] = media_codec.media_codec_information[2];
552     event[pos++] = media_codec.media_codec_information[3];
553     avdtp_emit_sink_and_source(event, pos);
554 }
555 
556 static inline void
557 avdtp_signaling_emit_capability(uint8_t capability_subevent_id, uint16_t avdtp_cid, uint8_t local_seid, uint8_t remote_seid) {
558     uint8_t event[7];
559     int pos = 0;
560     event[pos++] = HCI_EVENT_AVDTP_META;
561     event[pos++] = sizeof(event) - 2;
562     event[pos++] = capability_subevent_id;
563     little_endian_store_16(event, pos, avdtp_cid);
564     pos += 2;
565     event[pos++] = local_seid;
566     event[pos++] = remote_seid;
567     avdtp_emit_sink_and_source(event, pos);
568 }
569 
570 static void
571 avdtp_signaling_emit_media_transport_capability(uint16_t avdtp_cid, uint8_t local_seid, uint8_t remote_seid) {
572     avdtp_signaling_emit_capability(AVDTP_SUBEVENT_SIGNALING_MEDIA_TRANSPORT_CAPABILITY, avdtp_cid, local_seid,
573                                     remote_seid);
574 }
575 
576 static void avdtp_signaling_emit_reporting_capability(uint16_t avdtp_cid, uint8_t local_seid, uint8_t remote_seid) {
577     avdtp_signaling_emit_capability(AVDTP_SUBEVENT_SIGNALING_REPORTING_CAPABILITY, avdtp_cid, local_seid, remote_seid);
578 }
579 
580 static void
581 avdtp_signaling_emit_delay_reporting_capability(uint16_t avdtp_cid, uint8_t local_seid, uint8_t remote_seid) {
582     avdtp_signaling_emit_capability(AVDTP_SUBEVENT_SIGNALING_DELAY_REPORTING_CAPABILITY, avdtp_cid, local_seid,
583                                     remote_seid);
584 }
585 
586 static void avdtp_signaling_emit_recovery_capability(uint16_t avdtp_cid, uint8_t local_seid, uint8_t remote_seid,
587                                                      avdtp_recovery_capabilities_t *recovery) {
588     uint8_t event[10];
589     int pos = 0;
590     event[pos++] = HCI_EVENT_AVDTP_META;
591     event[pos++] = sizeof(event) - 2;
592     event[pos++] = AVDTP_SUBEVENT_SIGNALING_RECOVERY_CAPABILITY;
593     little_endian_store_16(event, pos, avdtp_cid);
594     pos += 2;
595     event[pos++] = local_seid;
596     event[pos++] = remote_seid;
597     event[pos++] = recovery->recovery_type;
598     event[pos++] = recovery->maximum_recovery_window_size;
599     event[pos++] = recovery->maximum_number_media_packets;
600     avdtp_emit_sink_and_source(event, pos);
601 }
602 
603 static void
604 avdtp_signaling_emit_content_protection_capability(uint16_t avdtp_cid, uint8_t local_seid, uint8_t remote_seid,
605                                                    adtvp_content_protection_t *content_protection) {
606     uint8_t event[22];
607     int pos = 0;
608     event[pos++] = HCI_EVENT_AVDTP_META;
609     event[pos++] = sizeof(event) - 2;
610     event[pos++] = AVDTP_SUBEVENT_SIGNALING_CONTENT_PROTECTION_CAPABILITY;
611     little_endian_store_16(event, pos, avdtp_cid);
612     pos += 2;
613     event[pos++] = local_seid;
614     event[pos++] = remote_seid;
615 
616     little_endian_store_16(event, pos, content_protection->cp_type);
617     pos += 2;
618     little_endian_store_16(event, pos, content_protection->cp_type_value_len);
619     pos += 2;
620 
621     //TODO: reserve place for value
622     if (content_protection->cp_type_value_len < 10){
623         (void)memcpy(event + pos, content_protection->cp_type_value,
624                      content_protection->cp_type_value_len);
625     }
626     avdtp_emit_sink_and_source(event, pos);
627 }
628 
629 
630 static void
631 avdtp_signaling_emit_header_compression_capability(uint16_t avdtp_cid, uint8_t local_seid, uint8_t remote_seid,
632                                                    avdtp_header_compression_capabilities_t *header_compression) {
633     uint8_t event[10];
634     int pos = 0;
635     event[pos++] = HCI_EVENT_AVDTP_META;
636     event[pos++] = sizeof(event) - 2;
637     event[pos++] = AVDTP_SUBEVENT_SIGNALING_HEADER_COMPRESSION_CAPABILITY;
638     little_endian_store_16(event, pos, avdtp_cid);
639     pos += 2;
640     event[pos++] = local_seid;
641     event[pos++] = remote_seid;
642     event[pos++] = header_compression->back_ch;
643     event[pos++] = header_compression->media;
644     event[pos++] = header_compression->recovery;
645     avdtp_emit_sink_and_source(event, pos);
646 }
647 
648 static void
649 avdtp_signaling_emit_content_multiplexing_capability(uint16_t avdtp_cid, uint8_t local_seid, uint8_t remote_seid,
650                                                      avdtp_multiplexing_mode_capabilities_t *multiplexing_mode) {
651     uint8_t event[15];
652     int pos = 0;
653     event[pos++] = HCI_EVENT_AVDTP_META;
654     event[pos++] = sizeof(event) - 2;
655     event[pos++] = AVDTP_SUBEVENT_SIGNALING_MULTIPLEXING_CAPABILITY;
656     little_endian_store_16(event, pos, avdtp_cid);
657     pos += 2;
658     event[pos++] = local_seid;
659     event[pos++] = remote_seid;
660 
661     event[pos++] = multiplexing_mode->fragmentation;
662     event[pos++] = multiplexing_mode->transport_identifiers_num;
663 
664     int i;
665     for (i = 0; i < 3; i++){
666         event[pos++] = multiplexing_mode->transport_session_identifiers[i];
667     }
668     for (i = 0; i < 3; i++){
669         event[pos++] = multiplexing_mode->tcid[i];
670     }
671     avdtp_emit_sink_and_source(event, pos);
672 }
673 
674 static void
675 avdtp_signaling_emit_media_codec_other_capability(uint16_t avdtp_cid, uint8_t local_seid, uint8_t remote_seid,
676                                                   adtvp_media_codec_capabilities_t media_codec) {
677     uint8_t event[MAX_MEDIA_CODEC_INFORMATION_LENGTH + 12];
678     int pos = 0;
679     event[pos++] = HCI_EVENT_AVDTP_META;
680     event[pos++] = sizeof(event) - 2;
681     event[pos++] = AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_OTHER_CAPABILITY;
682     little_endian_store_16(event, pos, avdtp_cid);
683     pos += 2;
684     event[pos++] = local_seid;
685     event[pos++] = remote_seid;
686     event[pos++] = media_codec.media_type;
687     little_endian_store_16(event, pos, media_codec.media_codec_type);
688     pos += 2;
689     little_endian_store_16(event, pos, media_codec.media_codec_information_len);
690     pos += 2;
691     (void)memcpy(event + pos, media_codec.media_codec_information,
692                  btstack_min(media_codec.media_codec_information_len, MAX_MEDIA_CODEC_INFORMATION_LENGTH));
693     avdtp_emit_sink_and_source(event, pos);
694 }
695 
696 static void avdtp_signaling_emit_capability_done(uint16_t avdtp_cid, uint8_t local_seid, uint8_t remote_seid) {
697     uint8_t event[7];
698     int pos = 0;
699     event[pos++] = HCI_EVENT_AVDTP_META;
700     event[pos++] = sizeof(event) - 2;
701     event[pos++] = AVDTP_SUBEVENT_SIGNALING_CAPABILITIES_DONE;
702     little_endian_store_16(event, pos, avdtp_cid);
703     pos += 2;
704     event[pos++] = local_seid;
705     event[pos++] = remote_seid;
706     avdtp_emit_sink_and_source(event, pos);
707 }
708 
709 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){
710     btstack_assert(callback != NULL);
711     uint8_t event[MAX_MEDIA_CODEC_INFORMATION_LENGTH + 13];
712     int pos = 0;
713     event[pos++] = HCI_EVENT_AVDTP_META;
714     event[pos++] = sizeof(event) - 2;
715     event[pos++] = AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_OTHER_CONFIGURATION;
716     little_endian_store_16(event, pos, avdtp_cid);
717     pos += 2;
718     event[pos++] = local_seid;
719     event[pos++] = remote_seid;
720     event[pos++] = reconfigure;
721     event[pos++] = media_codec.media_type;
722     little_endian_store_16(event, pos, media_codec.media_codec_type);
723     pos += 2;
724     little_endian_store_16(event, pos, media_codec.media_codec_information_len);
725     pos += 2;
726 
727     int media_codec_len = btstack_min(MAX_MEDIA_CODEC_INFORMATION_LENGTH, media_codec.media_codec_information_len);
728     (void)memcpy(event + pos, media_codec.media_codec_information,
729                  media_codec_len);
730 
731     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
732 }
733 
734 void avdtp_emit_capabilities(uint16_t avdtp_cid, uint8_t local_seid, uint8_t remote_seid, avdtp_capabilities_t *capabilities,
735                         uint16_t registered_service_categories) {
736     if (get_bit16(registered_service_categories, AVDTP_MEDIA_CODEC)){
737         switch (capabilities->media_codec.media_codec_type){
738             case AVDTP_CODEC_SBC:
739                 avdtp_signaling_emit_media_codec_sbc_capability(avdtp_cid, local_seid, remote_seid, capabilities->media_codec);
740                 break;
741             default:
742                 avdtp_signaling_emit_media_codec_other_capability(avdtp_cid, local_seid, remote_seid, capabilities->media_codec);
743                 break;
744         }
745     }
746 
747     if (get_bit16(registered_service_categories, AVDTP_MEDIA_TRANSPORT)){
748         avdtp_signaling_emit_media_transport_capability(avdtp_cid, local_seid, remote_seid);
749     }
750     if (get_bit16(registered_service_categories, AVDTP_REPORTING)){
751         avdtp_signaling_emit_reporting_capability(avdtp_cid, local_seid, remote_seid);
752     }
753     if (get_bit16(registered_service_categories, AVDTP_RECOVERY)){
754         avdtp_signaling_emit_recovery_capability(avdtp_cid, local_seid, remote_seid, &capabilities->recovery);
755     }
756     if (get_bit16(registered_service_categories, AVDTP_CONTENT_PROTECTION)){
757         avdtp_signaling_emit_content_protection_capability(avdtp_cid, local_seid, remote_seid,
758                                                            &capabilities->content_protection);
759     }
760     if (get_bit16(registered_service_categories, AVDTP_HEADER_COMPRESSION)){
761         avdtp_signaling_emit_header_compression_capability(avdtp_cid, local_seid, remote_seid,
762                                                            &capabilities->header_compression);
763     }
764     if (get_bit16(registered_service_categories, AVDTP_MULTIPLEXING)){
765         avdtp_signaling_emit_content_multiplexing_capability(avdtp_cid, local_seid, remote_seid,
766                                                              &capabilities->multiplexing_mode);
767     }
768     if (get_bit16(registered_service_categories, AVDTP_DELAY_REPORTING)){
769         avdtp_signaling_emit_delay_reporting_capability(avdtp_cid, local_seid, remote_seid);
770     }
771     avdtp_signaling_emit_capability_done(avdtp_cid, local_seid, remote_seid);
772 }
773 
774 uint8_t avdtp_request_can_send_now_acceptor(avdtp_connection_t * connection, uint16_t l2cap_cid){
775     if (!connection) return AVDTP_CONNECTION_DOES_NOT_EXIST;
776     connection->wait_to_send_acceptor = 1;
777     l2cap_request_can_send_now_event(l2cap_cid);
778     return ERROR_CODE_SUCCESS;
779 }
780 
781 uint8_t avdtp_request_can_send_now_initiator(avdtp_connection_t * connection, uint16_t l2cap_cid){
782     if (!connection) return AVDTP_CONNECTION_DOES_NOT_EXIST;
783     connection->wait_to_send_initiator = 1;
784     l2cap_request_can_send_now_event(l2cap_cid);
785     return ERROR_CODE_SUCCESS;
786 }
787 
788 uint8_t avdtp_local_seid(avdtp_stream_endpoint_t * stream_endpoint){
789     if (!stream_endpoint) return 0;
790     return stream_endpoint->sep.seid;
791 
792 }
793 
794 uint8_t avdtp_remote_seid(avdtp_stream_endpoint_t * stream_endpoint){
795     if (!stream_endpoint) return AVDTP_INVALID_SEP_SEID;
796     return stream_endpoint->remote_sep.seid;
797 }
798 
799 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){
800     btstack_assert(callback != NULL);
801     uint8_t event[14];
802     int pos = 0;
803     event[pos++] = HCI_EVENT_A2DP_META;
804     event[pos++] = sizeof(event) - 2;
805     event[pos++] = A2DP_SUBEVENT_STREAM_ESTABLISHED;
806     little_endian_store_16(event, pos, cid);
807     pos += 2;
808     reverse_bd_addr(addr,&event[pos]);
809     pos += 6;
810     event[pos++] = local_seid;
811     event[pos++] = remote_seid;
812     event[pos++] = status;
813     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
814 }
815