xref: /btstack/src/classic/avdtp_acceptor.c (revision f9f2075ceac5e9dc08e9abea437e43d733a3a0ea)
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 
39 #include <stdint.h>
40 #include <stdio.h>
41 #include <stdlib.h>
42 #include <string.h>
43 #include <unistd.h>
44 
45 #include "btstack.h"
46 #include "avdtp.h"
47 #include "avdtp_util.h"
48 #include "avdtp_acceptor.h"
49 
50 
51 static int avdtp_acceptor_send_accept_response(uint16_t cid,  uint8_t transaction_label, avdtp_signal_identifier_t identifier){
52     uint8_t command[2];
53     command[0] = avdtp_header(transaction_label, AVDTP_SINGLE_PACKET, AVDTP_RESPONSE_ACCEPT_MSG);
54     command[1] = (uint8_t)identifier;
55     return l2cap_send(cid, command, sizeof(command));
56 }
57 
58 static int avdtp_acceptor_process_chunk(avdtp_signaling_packet_t * signaling_packet, uint8_t * packet, uint16_t size){
59     memcpy(signaling_packet->command + signaling_packet->size, packet, size);
60     signaling_packet->size += size;
61     return signaling_packet->packet_type == AVDTP_SINGLE_PACKET || signaling_packet->packet_type == AVDTP_END_PACKET;
62 }
63 
64 static int avdtp_acceptor_validate_msg_length(avdtp_signal_identifier_t signal_identifier, uint16_t msg_size){
65     int minimal_msg_lenght = 2;
66     switch (signal_identifier){
67         case AVDTP_SI_GET_CAPABILITIES:
68         case AVDTP_SI_GET_ALL_CAPABILITIES:
69         case AVDTP_SI_SET_CONFIGURATION:
70         case AVDTP_SI_GET_CONFIGURATION:
71         case AVDTP_SI_START:
72         case AVDTP_SI_CLOSE:
73         case AVDTP_SI_ABORT:
74         case AVDTP_SI_RECONFIGURE:
75         case AVDTP_SI_OPEN:
76             minimal_msg_lenght = 3;
77             break;
78         default:
79             break;
80         }
81     return msg_size >= minimal_msg_lenght;
82 }
83 
84 void avdtp_acceptor_stream_config_subsm(avdtp_connection_t * connection, uint8_t * packet, uint16_t size, int offset){
85     avdtp_stream_endpoint_t * stream_endpoint;
86     connection->acceptor_transaction_label = connection->signaling_packet.transaction_label;
87 
88     if (!avdtp_acceptor_validate_msg_length(connection->signaling_packet.signal_identifier, size)) {
89         connection->error_code = BAD_LENGTH;
90         connection->acceptor_connection_state = AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_REJECT_WITH_ERROR_CODE;
91         connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
92         avdtp_sink_request_can_send_now_acceptor(connection, connection->l2cap_signaling_cid);
93         return;
94     }
95 
96     switch (connection->signaling_packet.signal_identifier){
97         case AVDTP_SI_DISCOVER:
98             if (connection->state != AVDTP_SIGNALING_CONNECTION_OPENED) return;
99             printf("    ACP: AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_ANSWER_DISCOVER_SEPS\n");
100             connection->acceptor_connection_state = AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_ANSWER_DISCOVER_SEPS;
101             avdtp_sink_request_can_send_now_acceptor(connection, connection->l2cap_signaling_cid);
102             return;
103         case AVDTP_SI_GET_CAPABILITIES:
104         case AVDTP_SI_GET_ALL_CAPABILITIES:
105         case AVDTP_SI_SET_CONFIGURATION:
106         case AVDTP_SI_GET_CONFIGURATION:
107         case AVDTP_SI_START:
108         case AVDTP_SI_CLOSE:
109         case AVDTP_SI_ABORT:
110         case AVDTP_SI_OPEN:
111         case AVDTP_SI_RECONFIGURE:
112             connection->query_seid  = packet[offset++] >> 2;
113             stream_endpoint = get_avdtp_stream_endpoint_with_seid(connection->query_seid);
114             if (!stream_endpoint){
115                 printf("    ACP: cmd %d - RESPONSE REJECT\n", connection->signaling_packet.signal_identifier);
116                 connection->error_code = BAD_ACP_SEID;
117                 if (connection->signaling_packet.signal_identifier == AVDTP_SI_OPEN){
118                     connection->error_code = BAD_STATE;
119                 }
120 
121                 connection->acceptor_connection_state = AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_REJECT_WITH_ERROR_CODE;
122                 if (connection->signaling_packet.signal_identifier == AVDTP_SI_RECONFIGURE){
123                     connection->reject_service_category = connection->query_seid;
124                     connection->acceptor_connection_state = AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE;
125                 }
126                 connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
127                 avdtp_sink_request_can_send_now_acceptor(connection, connection->l2cap_signaling_cid);
128                 return;
129             }
130             break;
131 
132         case AVDTP_SI_SUSPEND:{
133             int i;
134             printf("    ACP: AVDTP_SI_SUSPEND seids: ");
135             connection->num_suspended_seids = 0;
136 
137             for (i = offset; i < size; i++){
138                 connection->suspended_seids[connection->num_suspended_seids] = packet[i] >> 2;
139                 offset++;
140                 printf("%d, \n", connection->suspended_seids[connection->num_suspended_seids]);
141                 connection->num_suspended_seids++;
142             }
143 
144             if (connection->num_suspended_seids == 0) {
145                 printf("    ACP: CATEGORY RESPONSE REJECT BAD_ACP_SEID\n");
146                 connection->error_code = BAD_ACP_SEID;
147                 connection->reject_service_category = connection->query_seid;
148                 connection->acceptor_connection_state = AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE;
149                 connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
150                 avdtp_sink_request_can_send_now_acceptor(connection, connection->l2cap_signaling_cid);
151                 return;
152             }
153             // deal with first susspended seid
154             connection->query_seid = connection->suspended_seids[0];
155             stream_endpoint = get_avdtp_stream_endpoint_with_seid(connection->query_seid);
156             if (!stream_endpoint){
157                 printf("    ACP: stream_endpoint not found, CATEGORY RESPONSE REJECT BAD_ACP_SEID\n");
158                 connection->error_code = BAD_ACP_SEID;
159                 connection->reject_service_category = connection->query_seid;
160                 connection->acceptor_connection_state = AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE;
161                 connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
162                 connection->num_suspended_seids = 0;
163                 avdtp_sink_request_can_send_now_acceptor(connection, connection->l2cap_signaling_cid);
164                 return;
165             }
166             break;
167         }
168         default:
169             connection->acceptor_connection_state = AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_GENERAL_REJECT_WITH_ERROR_CODE;
170             connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
171             printf("AVDTP_CMD_MSG signal %d not implemented, general reject\n", connection->signaling_packet.signal_identifier);
172             avdtp_sink_request_can_send_now_acceptor(connection, connection->l2cap_signaling_cid);
173             return;
174     }
175 
176     if (!stream_endpoint) {
177         return;
178     }
179 
180     if (!avdtp_acceptor_process_chunk(&connection->signaling_packet, packet, size)) return;
181 
182     uint16_t packet_size = connection->signaling_packet.size;
183     connection->signaling_packet.size = 0;
184 
185     int request_to_send = 1;
186     switch (stream_endpoint->acceptor_config_state){
187         case AVDTP_ACCEPTOR_STREAM_CONFIG_IDLE:
188             switch (connection->signaling_packet.signal_identifier){
189                 case AVDTP_SI_GET_ALL_CAPABILITIES:
190                     printf("    ACP: AVDTP_SI_GET_ALL_CAPABILITIES\n");
191                     stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_ANSWER_GET_ALL_CAPABILITIES;
192                     break;
193                 case AVDTP_SI_GET_CAPABILITIES:
194                     printf("    ACP: AVDTP_ACCEPTOR_W2_ANSWER_GET_CAPABILITIES\n");
195                     stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_ANSWER_GET_CAPABILITIES;
196                     break;
197                 case AVDTP_SI_SET_CONFIGURATION:{
198                     printf("    ACP: AVDTP_ACCEPTOR_W2_ANSWER_SET_CONFIGURATION \n");
199                     stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_ANSWER_SET_CONFIGURATION;
200                     connection->reject_service_category = 0;
201 
202                     avdtp_sep_t sep;
203                     sep.seid = connection->signaling_packet.command[offset++] >> 2;
204                     sep.configured_service_categories = avdtp_unpack_service_capabilities(connection, &sep.configuration, connection->signaling_packet.command+offset, packet_size-offset);
205                     sep.in_use = 1;
206 
207                     if (connection->error_code){
208                         printf("fire configuration parsing errors \n");
209                         connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
210                         stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE;
211                         break;
212                     }
213                     // find or add sep
214                     int i;
215                     stream_endpoint->remote_sep_index = 0xFF;
216                     for (i=0; i < stream_endpoint->remote_seps_num; i++){
217                         if (stream_endpoint->remote_seps[i].seid == sep.seid){
218                             stream_endpoint->remote_sep_index = i;
219                         }
220                     }
221                     printf("    ACP .. seid %d, index %d\n", sep.seid, stream_endpoint->remote_sep_index);
222 
223                     if (stream_endpoint->remote_sep_index != 0xFF){
224                         if (stream_endpoint->remote_seps[stream_endpoint->remote_sep_index].in_use){
225                             // reject if already configured
226                             connection->error_code = SEP_IN_USE;
227                             // find first registered category and fire the error
228                             connection->reject_service_category = 0;
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->remote_seps[stream_endpoint->remote_sep_index] = sep;
239                             printf("    ACP: update seid %d, to %p\n", stream_endpoint->remote_seps[stream_endpoint->remote_sep_index].seid, stream_endpoint);
240                         }
241                     } else {
242                         // add new
243                         printf("    ACP: seid %d not found in %p\n", sep.seid, stream_endpoint);
244                         stream_endpoint->remote_sep_index = stream_endpoint->remote_seps_num;
245                         stream_endpoint->remote_seps_num++;
246                         stream_endpoint->remote_seps[stream_endpoint->remote_sep_index] = sep;
247                         printf("    ACP: add seid %d, to %p\n", stream_endpoint->remote_seps[stream_endpoint->remote_sep_index].seid, stream_endpoint);
248                     }
249 
250                     if (get_bit16(sep.configured_service_categories, AVDTP_MEDIA_CODEC)){
251                         switch (sep.configuration.media_codec.media_codec_type){
252                             case AVDTP_CODEC_SBC:
253                                 avdtp_signaling_emit_media_codec_sbc_configuration(avdtp_sink_callback, connection->con_handle, sep.configuration.media_codec);
254                                 break;
255                             default:
256                                 avdtp_signaling_emit_media_codec_other_configuration(avdtp_sink_callback, connection->con_handle, sep.configuration.media_codec);
257                                 break;
258                         }
259                     }
260                     avdtp_signaling_emit_accept(avdtp_sink_callback, connection->con_handle, connection->signaling_packet.signal_identifier, 0);
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->query_seid;
269                     printf("    ACP: AVDTP_ACCEPTOR_W2_ANSWER_RECONFIGURE seid %d\n", sep.seid);
270                     // printf_hexdump(connection->signaling_packet.command, packet_size);
271 
272                     sep.configured_service_categories = avdtp_unpack_service_capabilities(connection, &sep.configuration, connection->signaling_packet.command+offset, packet_size-offset);
273 
274                     if (connection->error_code){
275                         // fire configuration parsing errors
276                         connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
277                         stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE;
278                         break;
279                     }
280 
281                     // find sep or raise error
282                     int i;
283                     stream_endpoint->remote_sep_index = 0xFF;
284                     for (i = 0; i < stream_endpoint->remote_seps_num; i++){
285                         if (stream_endpoint->remote_seps[i].seid == sep.seid){
286                             stream_endpoint->remote_sep_index = i;
287                         }
288                     }
289 
290                     if (stream_endpoint->remote_sep_index == 0xFF){
291                         printf("    ACP: REJECT AVDTP_SI_RECONFIGURE, BAD_ACP_SEID\n");
292                         stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE;
293                         connection->error_code = BAD_ACP_SEID;
294                         connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
295                         break;
296                     }
297                     stream_endpoint->remote_seps[stream_endpoint->remote_sep_index] = sep;
298                     printf("    ACP: update seid %d, to %p\n", stream_endpoint->remote_seps[stream_endpoint->remote_sep_index].seid, stream_endpoint);
299 
300                     if (get_bit16(sep.configured_service_categories, AVDTP_MEDIA_CODEC)){
301                         switch (sep.capabilities.media_codec.media_codec_type){
302                             case AVDTP_CODEC_SBC:
303                                 avdtp_signaling_emit_media_codec_sbc_reconfiguration(avdtp_sink_callback, connection->con_handle, sep.capabilities.media_codec);
304                                 break;
305                             default:
306                                 avdtp_signaling_emit_media_codec_other_reconfiguration(avdtp_sink_callback, connection->con_handle, sep.capabilities.media_codec);
307                                 break;
308                         }
309                     }
310                     avdtp_signaling_emit_accept(avdtp_sink_callback, connection->con_handle, connection->signaling_packet.signal_identifier, 0);
311                     break;
312                 }
313 
314                 case AVDTP_SI_GET_CONFIGURATION:
315                     printf("    ACP: AVDTP_ACCEPTOR_W2_ANSWER_GET_CONFIGURATION\n");
316                     stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_ANSWER_GET_CONFIGURATION;
317                     break;
318                 case AVDTP_SI_OPEN:
319                     if (stream_endpoint->state != AVDTP_STREAM_ENDPOINT_CONFIGURED){
320                         printf("    ACP: REJECT AVDTP_SI_OPEN, BAD_STATE\n");
321                         stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_WITH_ERROR_CODE;
322                         connection->error_code = BAD_STATE;
323                         connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
324                         break;
325                     }
326                     printf("    ACP: AVDTP_STREAM_ENDPOINT_W2_ANSWER_OPEN_STREAM\n");
327                     stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_ANSWER_OPEN_STREAM;
328                     stream_endpoint->state = AVDTP_STREAM_ENDPOINT_W4_L2CAP_FOR_MEDIA_CONNECTED;
329                     break;
330                 case AVDTP_SI_START:
331                     if (stream_endpoint->state != AVDTP_STREAM_ENDPOINT_OPENED){
332                         printf("    ACP: REJECT AVDTP_SI_OPEN, BAD_STATE\n");
333                         stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE;
334                         connection->error_code = BAD_STATE;
335                         connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
336                         break;
337                     }
338                     printf("    ACP: AVDTP_ACCEPTOR_W2_ANSWER_START_STREAM\n");
339                     stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_ANSWER_START_STREAM;
340                     break;
341                 case AVDTP_SI_CLOSE:
342                     switch (stream_endpoint->state){
343                         case AVDTP_STREAM_ENDPOINT_OPENED:
344                         case AVDTP_STREAM_ENDPOINT_STREAMING:
345                             printf("    ACP: AVDTP_ACCEPTOR_W2_ANSWER_CLOSE_STREAM\n");
346                             stream_endpoint->state = AVDTP_STREAM_ENDPOINT_CLOSING;
347                             stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_ANSWER_CLOSE_STREAM;
348                             break;
349                         default:
350                             printf("    ACP: AVDTP_SI_CLOSE, bad state %d \n", stream_endpoint->state);
351                             stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_WITH_ERROR_CODE;
352                             connection->error_code = BAD_STATE;
353                             connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
354                             break;
355                     }
356                     break;
357                 case AVDTP_SI_ABORT:
358                      switch (stream_endpoint->state){
359                         case AVDTP_STREAM_ENDPOINT_CONFIGURED:
360                         case AVDTP_STREAM_ENDPOINT_CLOSING:
361                         case AVDTP_STREAM_ENDPOINT_OPENED:
362                         case AVDTP_STREAM_ENDPOINT_STREAMING:
363                             printf("    ACP: AVDTP_ACCEPTOR_W2_ANSWER_ABORT_STREAM\n");
364                             stream_endpoint->state = AVDTP_STREAM_ENDPOINT_ABORTING;
365                             stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_ANSWER_ABORT_STREAM;
366                             break;
367                         default:
368                             printf("    ACP: AVDTP_SI_ABORT, bad state %d \n", stream_endpoint->state);
369                             stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_WITH_ERROR_CODE;
370                             connection->error_code = BAD_STATE;
371                             connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
372                             break;
373                     }
374                     break;
375                 case AVDTP_SI_SUSPEND:
376                     printf(" entering AVDTP_SI_SUSPEND\n");
377                     switch (stream_endpoint->state){
378                         case AVDTP_STREAM_ENDPOINT_OPENED:
379                         case AVDTP_STREAM_ENDPOINT_STREAMING:
380                             stream_endpoint->state = AVDTP_STREAM_ENDPOINT_OPENED;
381                             connection->num_suspended_seids--;
382                             if (connection->num_suspended_seids <= 0){
383                                 printf("    ACP: AVDTP_ACCEPTOR_W2_ANSWER_SUSPEND_STREAM\n");
384                                 stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_ANSWER_SUSPEND_STREAM;
385                             }
386                             break;
387                         default:
388                             printf("    ACP: AVDTP_SI_SUSPEND, bad state \n");
389                             stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE;
390                             connection->error_code = BAD_STATE;
391                             connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
392                             break;
393                     }
394 
395                     //stream_endpoint->state = AVDTP_STREAM_ENDPOINT_SUSPENDING;
396                     //stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_SUSPEND_STREAM;
397                     break;
398                 default:
399                     printf("    ACP: NOT IMPLEMENTED, Reject signal_identifier %02x\n", connection->signaling_packet.signal_identifier);
400                     stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_UNKNOWN_CMD;
401                     connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
402                     break;
403             }
404             break;
405         default:
406             return;
407     }
408 
409     if (!request_to_send){
410         printf("    ACP: NOT IMPLEMENTED\n");
411     }
412     avdtp_sink_request_can_send_now_acceptor(connection, connection->l2cap_signaling_cid);
413 }
414 
415 static int avdtp_acceptor_send_seps_response(uint16_t cid, uint8_t transaction_label, avdtp_stream_endpoint_t * endpoints){
416     uint8_t command[2+2*MAX_NUM_SEPS];
417     int pos = 0;
418     command[pos++] = avdtp_header(transaction_label, AVDTP_SINGLE_PACKET, AVDTP_RESPONSE_ACCEPT_MSG);
419     command[pos++] = (uint8_t)AVDTP_SI_DISCOVER;
420 
421     btstack_linked_list_iterator_t it;
422     btstack_linked_list_iterator_init(&it, (btstack_linked_list_t *) endpoints);
423     while (btstack_linked_list_iterator_has_next(&it)){
424         avdtp_stream_endpoint_t * stream_endpoint = (avdtp_stream_endpoint_t *)btstack_linked_list_iterator_next(&it);
425         command[pos++] = (stream_endpoint->sep.seid << 2) | (stream_endpoint->sep.in_use<<1);
426         command[pos++] = (stream_endpoint->sep.media_type << 4) | (stream_endpoint->sep.type << 3);
427     }
428     return l2cap_send(cid, command, pos);
429 }
430 
431 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){
432     uint8_t command[4];
433     command[0] = avdtp_header(transaction_label, AVDTP_SINGLE_PACKET, AVDTP_RESPONSE_REJECT_MSG);
434     command[1] = (uint8_t)identifier;
435     command[2] = category;
436     command[3] = error_code;
437     return l2cap_send(cid, command, sizeof(command));
438 }
439 
440 static int avdtp_acceptor_send_response_general_reject(uint16_t cid, avdtp_signal_identifier_t identifier, uint8_t transaction_label){
441     uint8_t command[2];
442     command[0] = avdtp_header(transaction_label, AVDTP_SINGLE_PACKET, AVDTP_GENERAL_REJECT_MSG);
443     command[1] = (uint8_t)identifier;
444     return l2cap_send(cid, command, sizeof(command));
445 }
446 
447 static int avdtp_acceptor_send_response_reject(uint16_t cid, avdtp_signal_identifier_t identifier, uint8_t transaction_label){
448     uint8_t command[2];
449     command[0] = avdtp_header(transaction_label, AVDTP_SINGLE_PACKET, AVDTP_RESPONSE_REJECT_MSG);
450     command[1] = (uint8_t)identifier;
451     return l2cap_send(cid, command, sizeof(command));
452 }
453 
454 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){
455     uint8_t command[3];
456     command[0] = avdtp_header(transaction_label, AVDTP_SINGLE_PACKET, AVDTP_RESPONSE_REJECT_MSG);
457     command[1] = (uint8_t)identifier;
458     command[2] = error_code;
459     return l2cap_send(cid, command, sizeof(command));
460 }
461 
462 void avdtp_acceptor_stream_config_subsm_run(avdtp_connection_t * connection){
463     int sent = 1;
464 
465     switch (connection->acceptor_connection_state){
466         case AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_ANSWER_DISCOVER_SEPS:
467             printf(" -> AVDTP_SIGNALING_CONNECTION_OPENED\n");
468             connection->state = AVDTP_SIGNALING_CONNECTION_OPENED;
469             connection->acceptor_connection_state = AVDTP_SIGNALING_CONNECTION_ACCEPTOR_IDLE;
470             avdtp_acceptor_send_seps_response(connection->l2cap_signaling_cid, connection->acceptor_transaction_label, (avdtp_stream_endpoint_t *)&stream_endpoints);
471             break;
472         case AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_REJECT_WITH_ERROR_CODE:
473             connection->acceptor_connection_state = AVDTP_SIGNALING_CONNECTION_ACCEPTOR_IDLE;
474             avdtp_acceptor_send_response_reject_with_error_code(connection->l2cap_signaling_cid, connection->reject_signal_identifier, connection->error_code, connection->acceptor_transaction_label);
475             break;
476         case AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE:
477             connection->acceptor_connection_state = AVDTP_SIGNALING_CONNECTION_ACCEPTOR_IDLE;
478             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);
479             break;
480         case AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_GENERAL_REJECT_WITH_ERROR_CODE:
481             connection->acceptor_connection_state = AVDTP_SIGNALING_CONNECTION_ACCEPTOR_IDLE;
482             avdtp_acceptor_send_response_general_reject(connection->l2cap_signaling_cid, connection->reject_signal_identifier, connection->acceptor_transaction_label);
483         default:
484             sent = 0;
485             break;
486     }
487     if (sent) return;
488 
489     avdtp_stream_endpoint_t * stream_endpoint = get_avdtp_stream_endpoint_for_seid(connection->query_seid);
490     if (!stream_endpoint) return;
491 
492     uint8_t reject_service_category = connection->reject_service_category;
493     avdtp_signal_identifier_t reject_signal_identifier = connection->reject_signal_identifier;
494     uint8_t error_code = connection->error_code;
495     uint16_t cid = stream_endpoint->connection ? stream_endpoint->connection->l2cap_signaling_cid : connection->l2cap_signaling_cid;
496     uint8_t trid = stream_endpoint->connection ? stream_endpoint->connection->acceptor_transaction_label : connection->acceptor_transaction_label;
497 
498     avdtp_acceptor_stream_endpoint_state_t acceptor_config_state = stream_endpoint->acceptor_config_state;
499     stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_STREAM_CONFIG_IDLE;
500     uint8_t * out_buffer;
501     uint16_t pos;
502 
503     int status = 0;
504     switch (acceptor_config_state){
505         case AVDTP_ACCEPTOR_STREAM_CONFIG_IDLE:
506             break;
507         case AVDTP_ACCEPTOR_W2_ANSWER_GET_CAPABILITIES:
508             avdtp_prepare_capabilities(&connection->signaling_packet, trid, stream_endpoint->sep.registered_service_categories, stream_endpoint->sep.capabilities, AVDTP_SI_GET_CAPABILITIES);
509             l2cap_reserve_packet_buffer();
510             out_buffer = l2cap_get_outgoing_buffer();
511             pos = avdtp_signaling_create_fragment(cid, &connection->signaling_packet, out_buffer);
512             if (connection->signaling_packet.packet_type != AVDTP_SINGLE_PACKET && connection->signaling_packet.packet_type != AVDTP_END_PACKET){
513                 stream_endpoint->acceptor_config_state = acceptor_config_state;
514                 printf("    ACP: fragmented\n");
515             }
516             l2cap_send_prepared(cid, pos);
517             break;
518         case AVDTP_ACCEPTOR_W2_ANSWER_GET_ALL_CAPABILITIES:
519             avdtp_prepare_capabilities(&connection->signaling_packet, trid, stream_endpoint->sep.registered_service_categories, stream_endpoint->sep.capabilities, AVDTP_SI_GET_ALL_CAPABILITIES);
520             l2cap_reserve_packet_buffer();
521             out_buffer = l2cap_get_outgoing_buffer();
522             pos = avdtp_signaling_create_fragment(cid, &connection->signaling_packet, out_buffer);
523             if (connection->signaling_packet.packet_type != AVDTP_SINGLE_PACKET && connection->signaling_packet.packet_type != AVDTP_END_PACKET){
524                 stream_endpoint->acceptor_config_state = acceptor_config_state;
525                 printf("    ACP: fragmented\n");
526             }
527             l2cap_send_prepared(cid, pos);
528             break;
529         case AVDTP_ACCEPTOR_W2_ANSWER_SET_CONFIGURATION:
530             printf("    ACP: DONE\n");
531             printf("    -> AVDTP_STREAM_ENDPOINT_CONFIGURED\n");
532             stream_endpoint->connection = connection;
533             stream_endpoint->state = AVDTP_STREAM_ENDPOINT_CONFIGURED;
534             avdtp_acceptor_send_accept_response(cid, trid, AVDTP_SI_SET_CONFIGURATION);
535             break;
536         case AVDTP_ACCEPTOR_W2_ANSWER_RECONFIGURE:
537             printf("    ACP: DONE \n");
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->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                 printf("    ACP: fragmented\n");
550             }
551             l2cap_send_prepared(cid, pos);
552             break;
553         }
554         case AVDTP_ACCEPTOR_W4_L2CAP_FOR_MEDIA_CONNECTED:
555             stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W4_L2CAP_FOR_MEDIA_CONNECTED;
556             break;
557         case AVDTP_ACCEPTOR_W2_ANSWER_OPEN_STREAM:
558             printf("    ACP: DONE\n");
559             avdtp_acceptor_send_accept_response(cid, trid, AVDTP_SI_OPEN);
560             break;
561         case AVDTP_ACCEPTOR_W2_ANSWER_START_STREAM:
562             printf("    ACP: DONE \n");
563             printf("    -> AVDTP_STREAM_ENDPOINT_STREAMING \n");
564             stream_endpoint->state = AVDTP_STREAM_ENDPOINT_STREAMING;
565             avdtp_acceptor_send_accept_response(cid, trid, AVDTP_SI_START);
566             break;
567         case AVDTP_ACCEPTOR_W2_ANSWER_CLOSE_STREAM:
568             printf("    ACP: DONE\n");
569             avdtp_acceptor_send_accept_response(cid, trid, AVDTP_SI_CLOSE);
570             break;
571         case AVDTP_ACCEPTOR_W2_ANSWER_ABORT_STREAM:
572             printf("    ACP: DONE\n");
573             avdtp_acceptor_send_accept_response(cid, trid, AVDTP_SI_ABORT);
574             break;
575         case AVDTP_ACCEPTOR_W2_ANSWER_SUSPEND_STREAM:
576             printf("    ACP: DONE\n");
577             stream_endpoint->state = AVDTP_STREAM_ENDPOINT_OPENED;
578             avdtp_acceptor_send_accept_response(cid, trid, AVDTP_SI_SUSPEND);
579             break;
580         case AVDTP_ACCEPTOR_W2_REJECT_UNKNOWN_CMD:
581             status = 1;
582             printf("    ACP: DONE REJECT\n");
583             connection->reject_signal_identifier = 0;
584             avdtp_acceptor_send_response_reject(cid, reject_signal_identifier, trid);
585             break;
586         case AVDTP_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE:
587             status = 1;
588             printf("    ACP: DONE REJECT CATEGORY\n");
589             connection->reject_service_category = 0;
590             avdtp_acceptor_send_response_reject_service_category(cid, reject_signal_identifier, reject_service_category, error_code, trid);
591             break;
592 
593         case AVDTP_ACCEPTOR_W2_REJECT_WITH_ERROR_CODE:
594             status = 1;
595             printf("    ACP: DONE REJECT\n");
596             connection->reject_signal_identifier = 0;
597             connection->error_code = 0;
598             avdtp_acceptor_send_response_reject_with_error_code(cid, reject_signal_identifier, error_code, trid);
599             break;
600         default:
601             status = 0;
602             printf("    ACP: NOT IMPLEMENTED\n");
603             sent = 0;
604     }
605     avdtp_signaling_emit_accept(avdtp_sink_callback, connection->con_handle, connection->signaling_packet.signal_identifier, status);
606 
607     // check fragmentation
608     if (connection->signaling_packet.packet_type != AVDTP_SINGLE_PACKET && connection->signaling_packet.packet_type != AVDTP_END_PACKET){
609         avdtp_sink_request_can_send_now_acceptor(connection, connection->l2cap_signaling_cid);
610     }
611 }
612