xref: /btstack/src/classic/avdtp_acceptor.c (revision c37cd8f3d1350b92a2f66c31b2a5fcd75f8c91a4)
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 #define __BTSTACK_FILE__ "avdtp_acceptor.c"
38 
39 #include <stdint.h>
40 #include <stdio.h>
41 #include <stdlib.h>
42 #include <string.h>
43 
44 #include "btstack.h"
45 #include "classic/avdtp.h"
46 #include "classic/avdtp_util.h"
47 #include "classic/avdtp_acceptor.h"
48 
49 
50 static int avdtp_acceptor_send_accept_response(uint16_t cid,  uint8_t transaction_label, avdtp_signal_identifier_t identifier){
51     uint8_t command[2];
52     command[0] = avdtp_header(transaction_label, AVDTP_SINGLE_PACKET, AVDTP_RESPONSE_ACCEPT_MSG);
53     command[1] = (uint8_t)identifier;
54     return l2cap_send(cid, command, sizeof(command));
55 }
56 
57 static int avdtp_acceptor_process_chunk(avdtp_signaling_packet_t * signaling_packet, uint8_t * packet, uint16_t size){
58     memcpy(signaling_packet->command + signaling_packet->size, packet, size);
59     signaling_packet->size += size;
60     return signaling_packet->packet_type == AVDTP_SINGLE_PACKET || signaling_packet->packet_type == AVDTP_END_PACKET;
61 }
62 
63 static int avdtp_acceptor_validate_msg_length(avdtp_signal_identifier_t signal_identifier, uint16_t msg_size){
64     int minimal_msg_lenght = 2;
65     switch (signal_identifier){
66         case AVDTP_SI_GET_CAPABILITIES:
67         case AVDTP_SI_GET_ALL_CAPABILITIES:
68         case AVDTP_SI_SET_CONFIGURATION:
69         case AVDTP_SI_GET_CONFIGURATION:
70         case AVDTP_SI_START:
71         case AVDTP_SI_CLOSE:
72         case AVDTP_SI_ABORT:
73         case AVDTP_SI_RECONFIGURE:
74         case AVDTP_SI_OPEN:
75             minimal_msg_lenght = 3;
76             break;
77         default:
78             break;
79         }
80     return msg_size >= minimal_msg_lenght;
81 }
82 
83 void avdtp_acceptor_stream_config_subsm(avdtp_connection_t * connection, uint8_t * packet, uint16_t size, int offset, avdtp_context_t * context){
84     avdtp_stream_endpoint_t * stream_endpoint;
85     connection->acceptor_transaction_label = connection->signaling_packet.transaction_label;
86 
87     if (!avdtp_acceptor_validate_msg_length(connection->signaling_packet.signal_identifier, size)) {
88         connection->error_code = BAD_LENGTH;
89         connection->acceptor_connection_state = AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_REJECT_WITH_ERROR_CODE;
90         connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
91         avdtp_request_can_send_now_acceptor(connection, connection->l2cap_signaling_cid);
92         return;
93     }
94 
95     switch (connection->signaling_packet.signal_identifier){
96         case AVDTP_SI_DISCOVER:
97             if (connection->state != AVDTP_SIGNALING_CONNECTION_OPENED) return;
98             log_info("ACP: AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_ANSWER_DISCOVER_SEPS");
99             connection->acceptor_connection_state = AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_ANSWER_DISCOVER_SEPS;
100             avdtp_request_can_send_now_acceptor(connection, connection->l2cap_signaling_cid);
101             return;
102         case AVDTP_SI_GET_CAPABILITIES:
103         case AVDTP_SI_GET_ALL_CAPABILITIES:
104         case AVDTP_SI_SET_CONFIGURATION:
105         case AVDTP_SI_GET_CONFIGURATION:
106         case AVDTP_SI_START:
107         case AVDTP_SI_CLOSE:
108         case AVDTP_SI_ABORT:
109         case AVDTP_SI_OPEN:
110         case AVDTP_SI_RECONFIGURE:
111             connection->local_seid  = packet[offset++] >> 2;
112             stream_endpoint = avdtp_stream_endpoint_with_seid(connection->local_seid, context);
113             if (!stream_endpoint){
114                 log_info("ACP: cmd %d - RESPONSE REJECT", connection->signaling_packet.signal_identifier);
115                 connection->error_code = BAD_ACP_SEID;
116                 if (connection->signaling_packet.signal_identifier == AVDTP_SI_OPEN){
117                     connection->error_code = BAD_STATE;
118                 }
119 
120                 connection->acceptor_connection_state = AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_REJECT_WITH_ERROR_CODE;
121                 if (connection->signaling_packet.signal_identifier == AVDTP_SI_RECONFIGURE){
122                     connection->reject_service_category = connection->local_seid;
123                     connection->acceptor_connection_state = AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE;
124                 }
125                 connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
126                 avdtp_request_can_send_now_acceptor(connection, connection->l2cap_signaling_cid);
127                 return;
128             }
129             break;
130 
131         case AVDTP_SI_SUSPEND:{
132             int i;
133             log_info("ACP: AVDTP_SI_SUSPEND seids: ");
134             connection->num_suspended_seids = 0;
135 
136             for (i = offset; i < size; i++){
137                 connection->suspended_seids[connection->num_suspended_seids] = packet[i] >> 2;
138                 offset++;
139                 log_info("%d, ", connection->suspended_seids[connection->num_suspended_seids]);
140                 connection->num_suspended_seids++;
141             }
142 
143             if (connection->num_suspended_seids == 0) {
144                 log_info("ACP: CATEGORY RESPONSE REJECT BAD_ACP_SEID");
145                 connection->error_code = BAD_ACP_SEID;
146                 connection->reject_service_category = connection->local_seid;
147                 connection->acceptor_connection_state = AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE;
148                 connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
149                 avdtp_request_can_send_now_acceptor(connection, connection->l2cap_signaling_cid);
150                 return;
151             }
152             // deal with first susspended seid
153             connection->local_seid = connection->suspended_seids[0];
154             stream_endpoint = avdtp_stream_endpoint_with_seid(connection->local_seid, context);
155             if (!stream_endpoint){
156                 log_info("ACP: stream_endpoint not found, CATEGORY RESPONSE REJECT BAD_ACP_SEID");
157                 connection->error_code = BAD_ACP_SEID;
158                 connection->reject_service_category = connection->local_seid;
159                 connection->acceptor_connection_state = AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE;
160                 connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
161                 connection->num_suspended_seids = 0;
162                 avdtp_request_can_send_now_acceptor(connection, connection->l2cap_signaling_cid);
163                 return;
164             }
165             break;
166         }
167         default:
168             connection->acceptor_connection_state = AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_GENERAL_REJECT_WITH_ERROR_CODE;
169             connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
170             log_info("AVDTP_CMD_MSG signal %d not implemented, general reject", connection->signaling_packet.signal_identifier);
171             avdtp_request_can_send_now_acceptor(connection, connection->l2cap_signaling_cid);
172             return;
173     }
174 
175     if (!stream_endpoint) {
176         return;
177     }
178 
179     if (!avdtp_acceptor_process_chunk(&connection->signaling_packet, packet, size)) return;
180 
181     uint16_t packet_size = connection->signaling_packet.size;
182     connection->signaling_packet.size = 0;
183 
184     int request_to_send = 1;
185     switch (stream_endpoint->acceptor_config_state){
186         case AVDTP_ACCEPTOR_STREAM_CONFIG_IDLE:
187             switch (connection->signaling_packet.signal_identifier){
188                 case AVDTP_SI_GET_ALL_CAPABILITIES:
189                     log_info("ACP: AVDTP_SI_GET_ALL_CAPABILITIES");
190                     stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_ANSWER_GET_ALL_CAPABILITIES;
191                     break;
192                 case AVDTP_SI_GET_CAPABILITIES:
193                     log_info("ACP: AVDTP_ACCEPTOR_W2_ANSWER_GET_CAPABILITIES");
194                     stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_ANSWER_GET_CAPABILITIES;
195                     break;
196                 case AVDTP_SI_SET_CONFIGURATION:{
197                     log_info("ACP: AVDTP_ACCEPTOR_W2_ANSWER_SET_CONFIGURATION ");
198                     stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_ANSWER_SET_CONFIGURATION;
199                     connection->reject_service_category = 0;
200                     stream_endpoint->connection = connection;
201                     avdtp_sep_t sep;
202                     sep.seid = connection->signaling_packet.command[offset++] >> 2;
203                     sep.configured_service_categories = avdtp_unpack_service_capabilities(connection, &sep.configuration, connection->signaling_packet.command+offset, packet_size-offset);
204                     sep.in_use = 1;
205 
206                     if (connection->error_code){
207                         log_info("fire configuration parsing errors ");
208                         connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
209                         stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE;
210                         break;
211                     }
212                     // find or add sep
213 
214                     stream_endpoint->remote_sep_index = avdtp_find_remote_sep(stream_endpoint->connection, sep.seid);
215                     log_info("ACP .. seid %d, index %d", sep.seid, stream_endpoint->remote_sep_index);
216 
217                     if (stream_endpoint->remote_sep_index != AVDTP_INVALID_SEP_INDEX){
218                          if (stream_endpoint->connection->remote_seps[stream_endpoint->remote_sep_index].in_use){
219                             // if (stream_endpoint->state < AVDTP_STREAM_ENDPOINT_OPENED){
220                             //     stream_endpoint->connection->remote_seps[stream_endpoint->remote_sep_index] = sep;
221                             //     log_info("ACP: update seid %d, to %p", stream_endpoint->connection->remote_seps[stream_endpoint->remote_sep_index].seid, stream_endpoint);
222                             //     break;
223                             // }
224                             // reject if already configured
225                             connection->error_code = SEP_IN_USE;
226                             // find first registered category and fire the error
227                             connection->reject_service_category = 0;
228                             int i;
229                             for (i = 1; i < 9; i++){
230                                 if (get_bit16(sep.configured_service_categories, i)){
231                                     connection->reject_service_category = i;
232                                     break;
233                                 }
234                             }
235                             connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
236                             stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE;
237                         } else {
238                             stream_endpoint->connection->remote_seps[stream_endpoint->remote_sep_index] = sep;
239                             log_info("ACP: update seid %d, to %p", stream_endpoint->connection->remote_seps[stream_endpoint->remote_sep_index].seid, stream_endpoint);
240                         }
241                     } else {
242                         // add new
243                         log_info("ACP: seid %d not found in %p", sep.seid, stream_endpoint);
244                         stream_endpoint->remote_sep_index = connection->remote_seps_num;
245                         connection->remote_seps_num++;
246                         connection->remote_seps[stream_endpoint->remote_sep_index] = sep;
247                         log_info("ACP: add seid %d, to %p", connection->remote_seps[stream_endpoint->remote_sep_index].seid, stream_endpoint);
248                     }
249                     if (get_bit16(sep.configured_service_categories, AVDTP_MEDIA_CODEC)){
250                         switch (sep.configuration.media_codec.media_codec_type){
251                             case AVDTP_CODEC_SBC:
252                                 avdtp_signaling_emit_media_codec_sbc_configuration(context->avdtp_callback, connection->avdtp_cid, avdtp_local_seid(stream_endpoint), avdtp_remote_seid(stream_endpoint),
253                                     sep.configuration.media_codec.media_type, sep.configuration.media_codec.media_codec_information);
254                                 break;
255                             default:
256                                 avdtp_signaling_emit_media_codec_other_configuration(context->avdtp_callback, connection->avdtp_cid, avdtp_local_seid(stream_endpoint), avdtp_remote_seid(stream_endpoint), sep.configuration.media_codec);
257                                 break;
258                         }
259                     }
260                     avdtp_signaling_emit_accept(context->avdtp_callback, connection->avdtp_cid, avdtp_local_seid(stream_endpoint), connection->signaling_packet.signal_identifier);
261                     break;
262                 }
263                 case AVDTP_SI_RECONFIGURE:{
264                     stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_ANSWER_RECONFIGURE;
265                     connection->reject_service_category = 0;
266 
267                     avdtp_sep_t sep;
268                     sep.seid = connection->local_seid;
269                     log_info("ACP: AVDTP_ACCEPTOR_W2_ANSWER_RECONFIGURE seid %d", sep.seid);
270                     sep.configured_service_categories = avdtp_unpack_service_capabilities(connection, &sep.configuration, connection->signaling_packet.command+offset, packet_size-offset);
271                     if (connection->error_code){
272                         // fire configuration parsing errors
273                         connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
274                         stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE;
275                         break;
276                     }
277 
278                     // find sep or raise error
279                     stream_endpoint->remote_sep_index = avdtp_find_remote_sep(stream_endpoint->connection, sep.seid);
280                     if (stream_endpoint->remote_sep_index == AVDTP_INVALID_SEP_INDEX){
281                         log_info("ACP: REJECT AVDTP_SI_RECONFIGURE, BAD_ACP_SEID");
282                         stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE;
283                         connection->error_code = BAD_ACP_SEID;
284                         connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
285                         break;
286                     }
287                     stream_endpoint->connection->remote_seps[stream_endpoint->remote_sep_index] = sep;
288                     log_info("ACP: update seid %d, to %p", stream_endpoint->connection->remote_seps[stream_endpoint->remote_sep_index].seid, stream_endpoint);
289 
290                     if (get_bit16(sep.configured_service_categories, AVDTP_MEDIA_CODEC)){
291                         switch (sep.capabilities.media_codec.media_codec_type){
292                             case AVDTP_CODEC_SBC:
293                                 avdtp_signaling_emit_media_codec_sbc_reconfiguration(context->avdtp_callback, connection->avdtp_cid, avdtp_local_seid(stream_endpoint), avdtp_remote_seid(stream_endpoint),
294                                     sep.configuration.media_codec.media_type, sep.configuration.media_codec.media_codec_information);
295                                 break;
296                             default:
297                                 avdtp_signaling_emit_media_codec_other_reconfiguration(context->avdtp_callback, connection->avdtp_cid, avdtp_local_seid(stream_endpoint), avdtp_remote_seid(stream_endpoint), sep.configuration.media_codec);
298                                 break;
299                         }
300                     }
301                     avdtp_signaling_emit_accept(context->avdtp_callback, connection->avdtp_cid, avdtp_local_seid(stream_endpoint), connection->signaling_packet.signal_identifier);
302                     break;
303                 }
304 
305                 case AVDTP_SI_GET_CONFIGURATION:
306                     log_info("ACP: AVDTP_ACCEPTOR_W2_ANSWER_GET_CONFIGURATION");
307                     stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_ANSWER_GET_CONFIGURATION;
308                     break;
309                 case AVDTP_SI_OPEN:
310                     if (stream_endpoint->state != AVDTP_STREAM_ENDPOINT_CONFIGURED){
311                         log_info("ACP: REJECT AVDTP_SI_OPEN, BAD_STATE");
312                         stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_WITH_ERROR_CODE;
313                         connection->error_code = BAD_STATE;
314                         connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
315                         break;
316                     }
317                     log_info("ACP: AVDTP_STREAM_ENDPOINT_W2_ANSWER_OPEN_STREAM");
318                     stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_ANSWER_OPEN_STREAM;
319                     stream_endpoint->state = AVDTP_STREAM_ENDPOINT_W4_L2CAP_FOR_MEDIA_CONNECTED;
320                     connection->local_seid = stream_endpoint->sep.seid;
321                     break;
322                 case AVDTP_SI_START:
323                     if (stream_endpoint->state != AVDTP_STREAM_ENDPOINT_OPENED){
324                         log_info("ACP: REJECT AVDTP_SI_START, BAD_STATE");
325                         stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE;
326                         connection->error_code = BAD_STATE;
327                         connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
328                         break;
329                     }
330                     log_info("ACP: AVDTP_ACCEPTOR_W2_ANSWER_START_STREAM");
331                     stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_ANSWER_START_STREAM;
332                     break;
333                 case AVDTP_SI_CLOSE:
334                     switch (stream_endpoint->state){
335                         case AVDTP_STREAM_ENDPOINT_OPENED:
336                         case AVDTP_STREAM_ENDPOINT_STREAMING:
337                             log_info("ACP: AVDTP_ACCEPTOR_W2_ANSWER_CLOSE_STREAM");
338                             stream_endpoint->state = AVDTP_STREAM_ENDPOINT_CLOSING;
339                             stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_ANSWER_CLOSE_STREAM;
340                             break;
341                         default:
342                             log_info("ACP: AVDTP_SI_CLOSE, bad state %d ", stream_endpoint->state);
343                             stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_WITH_ERROR_CODE;
344                             connection->error_code = BAD_STATE;
345                             connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
346                             break;
347                     }
348                     break;
349                 case AVDTP_SI_ABORT:
350                      switch (stream_endpoint->state){
351                         case AVDTP_STREAM_ENDPOINT_CONFIGURED:
352                         case AVDTP_STREAM_ENDPOINT_CLOSING:
353                         case AVDTP_STREAM_ENDPOINT_OPENED:
354                         case AVDTP_STREAM_ENDPOINT_STREAMING:
355                             log_info("ACP: AVDTP_ACCEPTOR_W2_ANSWER_ABORT_STREAM");
356                             stream_endpoint->state = AVDTP_STREAM_ENDPOINT_ABORTING;
357                             stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_ANSWER_ABORT_STREAM;
358                             break;
359                         default:
360                             log_info("ACP: AVDTP_SI_ABORT, bad state %d ", stream_endpoint->state);
361                             stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_WITH_ERROR_CODE;
362                             connection->error_code = BAD_STATE;
363                             connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
364                             break;
365                     }
366                     break;
367                 case AVDTP_SI_SUSPEND:
368                     log_info(" entering AVDTP_SI_SUSPEND");
369                     switch (stream_endpoint->state){
370                         case AVDTP_STREAM_ENDPOINT_OPENED:
371                         case AVDTP_STREAM_ENDPOINT_STREAMING:
372                             stream_endpoint->state = AVDTP_STREAM_ENDPOINT_OPENED;
373                             connection->num_suspended_seids--;
374                             if (connection->num_suspended_seids <= 0){
375                                 log_info("ACP: AVDTP_ACCEPTOR_W2_ANSWER_SUSPEND_STREAM");
376                                 stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_ANSWER_SUSPEND_STREAM;
377                             }
378                             break;
379                         default:
380                             log_info("ACP: AVDTP_SI_SUSPEND, bad state ");
381                             stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE;
382                             connection->error_code = BAD_STATE;
383                             connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
384                             break;
385                     }
386 
387                     //stream_endpoint->state = AVDTP_STREAM_ENDPOINT_SUSPENDING;
388                     //stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_SUSPEND_STREAM;
389                     break;
390                 default:
391                     log_info("ACP: NOT IMPLEMENTED, Reject signal_identifier %02x", connection->signaling_packet.signal_identifier);
392                     stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_UNKNOWN_CMD;
393                     connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
394                     break;
395             }
396             break;
397         default:
398             return;
399     }
400 
401     if (!request_to_send){
402         log_info("ACP: NOT IMPLEMENTED");
403     }
404     avdtp_request_can_send_now_acceptor(connection, connection->l2cap_signaling_cid);
405 }
406 
407 static int avdtp_acceptor_send_seps_response(uint16_t cid, uint8_t transaction_label, avdtp_stream_endpoint_t * endpoints){
408     uint8_t command[2+2*MAX_NUM_SEPS];
409     int pos = 0;
410     command[pos++] = avdtp_header(transaction_label, AVDTP_SINGLE_PACKET, AVDTP_RESPONSE_ACCEPT_MSG);
411     command[pos++] = (uint8_t)AVDTP_SI_DISCOVER;
412 
413     btstack_linked_list_iterator_t it;
414     btstack_linked_list_iterator_init(&it, (btstack_linked_list_t *) endpoints);
415     while (btstack_linked_list_iterator_has_next(&it)){
416         avdtp_stream_endpoint_t * stream_endpoint = (avdtp_stream_endpoint_t *)btstack_linked_list_iterator_next(&it);
417         command[pos++] = (stream_endpoint->sep.seid << 2) | (stream_endpoint->sep.in_use<<1);
418         command[pos++] = (stream_endpoint->sep.media_type << 4) | (stream_endpoint->sep.type << 3);
419     }
420     return l2cap_send(cid, command, pos);
421 }
422 
423 static int avdtp_acceptor_send_response_reject_service_category(uint16_t cid,  avdtp_signal_identifier_t identifier, uint8_t category, uint8_t error_code, uint8_t transaction_label){
424     uint8_t command[4];
425     command[0] = avdtp_header(transaction_label, AVDTP_SINGLE_PACKET, AVDTP_RESPONSE_REJECT_MSG);
426     command[1] = (uint8_t)identifier;
427     command[2] = category;
428     command[3] = error_code;
429     return l2cap_send(cid, command, sizeof(command));
430 }
431 
432 static int avdtp_acceptor_send_response_general_reject(uint16_t cid, avdtp_signal_identifier_t identifier, uint8_t transaction_label){
433     uint8_t command[2];
434     command[0] = avdtp_header(transaction_label, AVDTP_SINGLE_PACKET, AVDTP_GENERAL_REJECT_MSG);
435     command[1] = (uint8_t)identifier;
436     return l2cap_send(cid, command, sizeof(command));
437 }
438 
439 static int avdtp_acceptor_send_response_reject(uint16_t cid, avdtp_signal_identifier_t identifier, uint8_t transaction_label){
440     uint8_t command[2];
441     command[0] = avdtp_header(transaction_label, AVDTP_SINGLE_PACKET, AVDTP_RESPONSE_REJECT_MSG);
442     command[1] = (uint8_t)identifier;
443     return l2cap_send(cid, command, sizeof(command));
444 }
445 
446 static int avdtp_acceptor_send_response_reject_with_error_code(uint16_t cid, avdtp_signal_identifier_t identifier, uint8_t error_code, uint8_t transaction_label){
447     uint8_t command[3];
448     command[0] = avdtp_header(transaction_label, AVDTP_SINGLE_PACKET, AVDTP_RESPONSE_REJECT_MSG);
449     command[1] = (uint8_t)identifier;
450     command[2] = error_code;
451     return l2cap_send(cid, command, sizeof(command));
452 }
453 
454 void avdtp_acceptor_stream_config_subsm_run(avdtp_connection_t * connection, avdtp_context_t * context){
455     int sent = 1;
456     btstack_linked_list_t * stream_endpoints = &context->stream_endpoints;
457 
458     switch (connection->acceptor_connection_state){
459         case AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_ANSWER_DISCOVER_SEPS:
460             connection->state = AVDTP_SIGNALING_CONNECTION_OPENED;
461             connection->acceptor_connection_state = AVDTP_SIGNALING_CONNECTION_ACCEPTOR_IDLE;
462             avdtp_acceptor_send_seps_response(connection->l2cap_signaling_cid, connection->acceptor_transaction_label, (avdtp_stream_endpoint_t *) stream_endpoints);
463             break;
464         case AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_REJECT_WITH_ERROR_CODE:
465             connection->acceptor_connection_state = AVDTP_SIGNALING_CONNECTION_ACCEPTOR_IDLE;
466             avdtp_acceptor_send_response_reject_with_error_code(connection->l2cap_signaling_cid, connection->reject_signal_identifier, connection->error_code, connection->acceptor_transaction_label);
467             break;
468         case AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE:
469             connection->acceptor_connection_state = AVDTP_SIGNALING_CONNECTION_ACCEPTOR_IDLE;
470             avdtp_acceptor_send_response_reject_service_category(connection->l2cap_signaling_cid, connection->reject_signal_identifier, connection->reject_service_category, connection->error_code, connection->acceptor_transaction_label);
471             break;
472         case AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_GENERAL_REJECT_WITH_ERROR_CODE:
473             connection->acceptor_connection_state = AVDTP_SIGNALING_CONNECTION_ACCEPTOR_IDLE;
474             avdtp_acceptor_send_response_general_reject(connection->l2cap_signaling_cid, connection->reject_signal_identifier, connection->acceptor_transaction_label);
475             break;
476         default:
477             sent = 0;
478             break;
479     }
480     if (sent){
481         log_info("ACP: DONE");
482         return;
483     }
484 
485     avdtp_stream_endpoint_t * stream_endpoint = avdtp_stream_endpoint_for_seid(connection->local_seid, context);
486     if (!stream_endpoint) return;
487 
488     uint8_t reject_service_category = connection->reject_service_category;
489     avdtp_signal_identifier_t reject_signal_identifier = connection->reject_signal_identifier;
490     uint8_t error_code = connection->error_code;
491     uint16_t cid = stream_endpoint->connection ? stream_endpoint->connection->l2cap_signaling_cid : connection->l2cap_signaling_cid;
492     uint8_t trid = stream_endpoint->connection ? stream_endpoint->connection->acceptor_transaction_label : connection->acceptor_transaction_label;
493 
494     avdtp_acceptor_stream_endpoint_state_t acceptor_config_state = stream_endpoint->acceptor_config_state;
495     stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_STREAM_CONFIG_IDLE;
496     uint8_t * out_buffer;
497     uint16_t pos;
498 
499     switch (acceptor_config_state){
500         case AVDTP_ACCEPTOR_STREAM_CONFIG_IDLE:
501             break;
502         case AVDTP_ACCEPTOR_W2_ANSWER_GET_CAPABILITIES:
503             avdtp_prepare_capabilities(&connection->signaling_packet, trid, stream_endpoint->sep.registered_service_categories, stream_endpoint->sep.capabilities, AVDTP_SI_GET_CAPABILITIES);
504             l2cap_reserve_packet_buffer();
505             out_buffer = l2cap_get_outgoing_buffer();
506             pos = avdtp_signaling_create_fragment(cid, &connection->signaling_packet, out_buffer);
507             if (connection->signaling_packet.packet_type != AVDTP_SINGLE_PACKET && connection->signaling_packet.packet_type != AVDTP_END_PACKET){
508                 stream_endpoint->acceptor_config_state = acceptor_config_state;
509                 log_info("ACP: fragmented");
510             } else {
511                 log_info("ACP:DONE");
512             }
513             l2cap_send_prepared(cid, pos);
514             break;
515         case AVDTP_ACCEPTOR_W2_ANSWER_GET_ALL_CAPABILITIES:
516             avdtp_prepare_capabilities(&connection->signaling_packet, trid, stream_endpoint->sep.registered_service_categories, stream_endpoint->sep.capabilities, AVDTP_SI_GET_ALL_CAPABILITIES);
517             l2cap_reserve_packet_buffer();
518             out_buffer = l2cap_get_outgoing_buffer();
519             pos = avdtp_signaling_create_fragment(cid, &connection->signaling_packet, out_buffer);
520             if (connection->signaling_packet.packet_type != AVDTP_SINGLE_PACKET && connection->signaling_packet.packet_type != AVDTP_END_PACKET){
521                 stream_endpoint->acceptor_config_state = acceptor_config_state;
522                 log_info("ACP: fragmented");
523             } else {
524                 log_info("ACP:DONE");
525             }
526             l2cap_send_prepared(cid, pos);
527             break;
528         case AVDTP_ACCEPTOR_W2_ANSWER_SET_CONFIGURATION:
529             log_info("ACP: DONE");
530             log_info("    -> AVDTP_STREAM_ENDPOINT_CONFIGURED");
531             stream_endpoint->connection = connection;
532             stream_endpoint->state = AVDTP_STREAM_ENDPOINT_CONFIGURED;
533             // TODO: consider reconfiguration
534             avdtp_acceptor_send_accept_response(cid, trid, AVDTP_SI_SET_CONFIGURATION);
535             break;
536         case AVDTP_ACCEPTOR_W2_ANSWER_RECONFIGURE:
537             log_info("ACP: DONE ");
538             avdtp_acceptor_send_accept_response(cid, trid, AVDTP_SI_RECONFIGURE);
539             break;
540 
541         case AVDTP_ACCEPTOR_W2_ANSWER_GET_CONFIGURATION:{
542             avdtp_sep_t sep = stream_endpoint->connection->remote_seps[stream_endpoint->remote_sep_index];
543             avdtp_prepare_capabilities(&connection->signaling_packet, trid, sep.configured_service_categories, sep.configuration, AVDTP_SI_GET_CONFIGURATION);
544             l2cap_reserve_packet_buffer();
545             out_buffer = l2cap_get_outgoing_buffer();
546             pos = avdtp_signaling_create_fragment(cid, &connection->signaling_packet, out_buffer);
547             if (connection->signaling_packet.packet_type != AVDTP_SINGLE_PACKET && connection->signaling_packet.packet_type != AVDTP_END_PACKET){
548                 stream_endpoint->acceptor_config_state = acceptor_config_state;
549                 log_info("ACP: fragmented");
550             } else {
551                 log_info("ACP:DONE");
552             }
553             l2cap_send_prepared(cid, pos);
554             break;
555         }
556         case AVDTP_ACCEPTOR_W2_ANSWER_OPEN_STREAM:
557             log_info("ACP: DONE");
558             avdtp_acceptor_send_accept_response(cid, trid, AVDTP_SI_OPEN);
559             break;
560         case AVDTP_ACCEPTOR_W2_ANSWER_START_STREAM:
561             log_info("ACP: DONE ");
562             log_info("    -> AVDTP_STREAM_ENDPOINT_STREAMING ");
563             stream_endpoint->state = AVDTP_STREAM_ENDPOINT_STREAMING;
564             avdtp_acceptor_send_accept_response(cid, trid, AVDTP_SI_START);
565             break;
566         case AVDTP_ACCEPTOR_W2_ANSWER_CLOSE_STREAM:
567             log_info("ACP: DONE");
568             avdtp_acceptor_send_accept_response(cid, trid, AVDTP_SI_CLOSE);
569             break;
570         case AVDTP_ACCEPTOR_W2_ANSWER_ABORT_STREAM:
571             log_info("ACP: DONE");
572             avdtp_acceptor_send_accept_response(cid, trid, AVDTP_SI_ABORT);
573             break;
574         case AVDTP_ACCEPTOR_W2_ANSWER_SUSPEND_STREAM:
575             log_info("ACP: DONE");
576             stream_endpoint->state = AVDTP_STREAM_ENDPOINT_OPENED;
577             avdtp_acceptor_send_accept_response(cid, trid, AVDTP_SI_SUSPEND);
578             break;
579         case AVDTP_ACCEPTOR_W2_REJECT_UNKNOWN_CMD:
580             log_info("ACP: DONE REJECT");
581             connection->reject_signal_identifier = AVDTP_SI_NONE;
582             avdtp_acceptor_send_response_reject(cid, reject_signal_identifier, trid);
583             break;
584         case AVDTP_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE:
585             log_info("ACP: DONE REJECT CATEGORY");
586             connection->reject_service_category = 0;
587             avdtp_acceptor_send_response_reject_service_category(cid, reject_signal_identifier, reject_service_category, error_code, trid);
588             break;
589         case AVDTP_ACCEPTOR_W2_REJECT_WITH_ERROR_CODE:
590             log_info("ACP: DONE REJECT");
591             connection->reject_signal_identifier = AVDTP_SI_NONE;
592             connection->error_code = 0;
593             avdtp_acceptor_send_response_reject_with_error_code(cid, reject_signal_identifier, error_code, trid);
594             break;
595         default:
596             log_info("ACP: NOT IMPLEMENTED");
597             sent = 0;
598             break;
599     }
600     avdtp_signaling_emit_accept(context->avdtp_callback, connection->avdtp_cid, avdtp_local_seid(stream_endpoint), connection->signaling_packet.signal_identifier);
601     // check fragmentation
602     if (connection->signaling_packet.packet_type != AVDTP_SINGLE_PACKET && connection->signaling_packet.packet_type != AVDTP_END_PACKET){
603         avdtp_request_can_send_now_acceptor(connection, connection->l2cap_signaling_cid);
604     }
605 }
606