xref: /btstack/src/classic/avdtp_acceptor.c (revision 0da182f51cb51bd0dddf7f896f3c4a9461fbe57b)
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 #include <stdint.h>
39 #include <stdio.h>
40 #include <stdlib.h>
41 #include <string.h>
42 #include <unistd.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->query_seid  = packet[offset++] >> 2;
112             stream_endpoint = avdtp_stream_endpoint_with_seid(connection->query_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->query_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->query_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->query_seid = connection->suspended_seids[0];
154             stream_endpoint = avdtp_stream_endpoint_with_seid(connection->query_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->query_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                             // reject if already configured
220                             connection->error_code = SEP_IN_USE;
221                             // find first registered category and fire the error
222                             connection->reject_service_category = 0;
223                             int i;
224                             for (i = 1; i < 9; i++){
225                                 if (get_bit16(sep.configured_service_categories, i)){
226                                     connection->reject_service_category = i;
227                                     break;
228                                 }
229                             }
230                             connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
231                             stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE;
232                         } else {
233                             stream_endpoint->connection->remote_seps[stream_endpoint->remote_sep_index] = sep;
234                             log_info("    ACP: update seid %d, to %p", stream_endpoint->connection->remote_seps[stream_endpoint->remote_sep_index].seid, stream_endpoint);
235                         }
236                     } else {
237                         // add new
238                         log_info("    ACP: seid %d not found in %p", sep.seid, stream_endpoint);
239                         stream_endpoint->remote_sep_index = connection->remote_seps_num;
240                         connection->remote_seps_num++;
241                         connection->remote_seps[stream_endpoint->remote_sep_index] = sep;
242                         log_info("    ACP: add seid %d, to %p", connection->remote_seps[stream_endpoint->remote_sep_index].seid, stream_endpoint);
243                     }
244                     if (get_bit16(sep.configured_service_categories, AVDTP_MEDIA_CODEC)){
245                         switch (sep.configuration.media_codec.media_codec_type){
246                             case AVDTP_CODEC_SBC:
247                                 avdtp_signaling_emit_media_codec_sbc_configuration(context->avdtp_callback, connection->con_handle, connection->int_seid, connection->acp_seid, sep.configuration.media_codec);
248                                 break;
249                             default:
250                                 avdtp_signaling_emit_media_codec_other_configuration(context->avdtp_callback, connection->con_handle, connection->int_seid, connection->acp_seid, sep.configuration.media_codec);
251                                 break;
252                         }
253                     }
254                     avdtp_signaling_emit_accept(context->avdtp_callback, connection->con_handle, connection->int_seid, connection->signaling_packet.signal_identifier, 0);
255                     break;
256                 }
257                 case AVDTP_SI_RECONFIGURE:{
258                     stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_ANSWER_RECONFIGURE;
259                     connection->reject_service_category = 0;
260 
261                     avdtp_sep_t sep;
262                     sep.seid = connection->query_seid;
263                     log_info("    ACP: AVDTP_ACCEPTOR_W2_ANSWER_RECONFIGURE seid %d", sep.seid);
264                     // log_info_hexdump(connection->signaling_packet.command, packet_size);
265 
266                     sep.configured_service_categories = avdtp_unpack_service_capabilities(connection, &sep.configuration, connection->signaling_packet.command+offset, packet_size-offset);
267 
268                     if (connection->error_code){
269                         // fire configuration parsing errors
270                         connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
271                         stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE;
272                         break;
273                     }
274 
275                     // find sep or raise error
276 
277                     stream_endpoint->remote_sep_index = avdtp_find_remote_sep(stream_endpoint->connection, sep.seid);
278                     if (stream_endpoint->remote_sep_index == AVDTP_INVALID_SEP_INDEX){
279                         log_info("    ACP: REJECT AVDTP_SI_RECONFIGURE, BAD_ACP_SEID");
280                         stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE;
281                         connection->error_code = BAD_ACP_SEID;
282                         connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
283                         break;
284                     }
285                     stream_endpoint->connection->remote_seps[stream_endpoint->remote_sep_index] = sep;
286                     log_info("    ACP: update seid %d, to %p", stream_endpoint->connection->remote_seps[stream_endpoint->remote_sep_index].seid, stream_endpoint);
287 
288                     if (get_bit16(sep.configured_service_categories, AVDTP_MEDIA_CODEC)){
289                         switch (sep.capabilities.media_codec.media_codec_type){
290                             case AVDTP_CODEC_SBC:
291                                 avdtp_signaling_emit_media_codec_sbc_reconfiguration(context->avdtp_callback, connection->con_handle, connection->int_seid, connection->acp_seid, sep.capabilities.media_codec);
292                                 break;
293                             default:
294                                 avdtp_signaling_emit_media_codec_other_reconfiguration(context->avdtp_callback, connection->con_handle, connection->int_seid, connection->acp_seid, sep.capabilities.media_codec);
295                                 break;
296                         }
297                     }
298                     avdtp_signaling_emit_accept(context->avdtp_callback, connection->con_handle, connection->int_seid, connection->signaling_packet.signal_identifier, 0);
299                     break;
300                 }
301 
302                 case AVDTP_SI_GET_CONFIGURATION:
303                     log_info("    ACP: AVDTP_ACCEPTOR_W2_ANSWER_GET_CONFIGURATION");
304                     stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_ANSWER_GET_CONFIGURATION;
305                     break;
306                 case AVDTP_SI_OPEN:
307                     if (stream_endpoint->state != AVDTP_STREAM_ENDPOINT_CONFIGURED){
308                         log_info("    ACP: REJECT AVDTP_SI_OPEN, BAD_STATE");
309                         stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_WITH_ERROR_CODE;
310                         connection->error_code = BAD_STATE;
311                         connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
312                         break;
313                     }
314                     log_info("    ACP: AVDTP_STREAM_ENDPOINT_W2_ANSWER_OPEN_STREAM");
315                     stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_ANSWER_OPEN_STREAM;
316                     stream_endpoint->state = AVDTP_STREAM_ENDPOINT_W4_L2CAP_FOR_MEDIA_CONNECTED;
317                     connection->query_seid = stream_endpoint->sep.seid;
318                     break;
319                 case AVDTP_SI_START:
320                     if (stream_endpoint->state != AVDTP_STREAM_ENDPOINT_OPENED){
321                         log_info("    ACP: REJECT AVDTP_SI_START, BAD_STATE");
322                         stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE;
323                         connection->error_code = BAD_STATE;
324                         connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
325                         break;
326                     }
327                     log_info("    ACP: AVDTP_ACCEPTOR_W2_ANSWER_START_STREAM");
328                     stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_ANSWER_START_STREAM;
329                     break;
330                 case AVDTP_SI_CLOSE:
331                     switch (stream_endpoint->state){
332                         case AVDTP_STREAM_ENDPOINT_OPENED:
333                         case AVDTP_STREAM_ENDPOINT_STREAMING:
334                             log_info("    ACP: AVDTP_ACCEPTOR_W2_ANSWER_CLOSE_STREAM");
335                             stream_endpoint->state = AVDTP_STREAM_ENDPOINT_CLOSING;
336                             stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_ANSWER_CLOSE_STREAM;
337                             break;
338                         default:
339                             log_info("    ACP: AVDTP_SI_CLOSE, bad state %d ", stream_endpoint->state);
340                             stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_WITH_ERROR_CODE;
341                             connection->error_code = BAD_STATE;
342                             connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
343                             break;
344                     }
345                     break;
346                 case AVDTP_SI_ABORT:
347                      switch (stream_endpoint->state){
348                         case AVDTP_STREAM_ENDPOINT_CONFIGURED:
349                         case AVDTP_STREAM_ENDPOINT_CLOSING:
350                         case AVDTP_STREAM_ENDPOINT_OPENED:
351                         case AVDTP_STREAM_ENDPOINT_STREAMING:
352                             log_info("    ACP: AVDTP_ACCEPTOR_W2_ANSWER_ABORT_STREAM");
353                             stream_endpoint->state = AVDTP_STREAM_ENDPOINT_ABORTING;
354                             stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_ANSWER_ABORT_STREAM;
355                             break;
356                         default:
357                             log_info("    ACP: AVDTP_SI_ABORT, bad state %d ", stream_endpoint->state);
358                             stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_WITH_ERROR_CODE;
359                             connection->error_code = BAD_STATE;
360                             connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
361                             break;
362                     }
363                     break;
364                 case AVDTP_SI_SUSPEND:
365                     log_info(" entering AVDTP_SI_SUSPEND");
366                     switch (stream_endpoint->state){
367                         case AVDTP_STREAM_ENDPOINT_OPENED:
368                         case AVDTP_STREAM_ENDPOINT_STREAMING:
369                             stream_endpoint->state = AVDTP_STREAM_ENDPOINT_OPENED;
370                             connection->num_suspended_seids--;
371                             if (connection->num_suspended_seids <= 0){
372                                 log_info("    ACP: AVDTP_ACCEPTOR_W2_ANSWER_SUSPEND_STREAM");
373                                 stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_ANSWER_SUSPEND_STREAM;
374                             }
375                             break;
376                         default:
377                             log_info("    ACP: AVDTP_SI_SUSPEND, bad state ");
378                             stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE;
379                             connection->error_code = BAD_STATE;
380                             connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
381                             break;
382                     }
383 
384                     //stream_endpoint->state = AVDTP_STREAM_ENDPOINT_SUSPENDING;
385                     //stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_SUSPEND_STREAM;
386                     break;
387                 default:
388                     log_info("    ACP: NOT IMPLEMENTED, Reject signal_identifier %02x", connection->signaling_packet.signal_identifier);
389                     stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_UNKNOWN_CMD;
390                     connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
391                     break;
392             }
393             break;
394         default:
395             return;
396     }
397 
398     if (!request_to_send){
399         log_info("    ACP: NOT IMPLEMENTED");
400     }
401     avdtp_request_can_send_now_acceptor(connection, connection->l2cap_signaling_cid);
402 }
403 
404 static int avdtp_acceptor_send_seps_response(uint16_t cid, uint8_t transaction_label, avdtp_stream_endpoint_t * endpoints){
405     uint8_t command[2+2*MAX_NUM_SEPS];
406     int pos = 0;
407     command[pos++] = avdtp_header(transaction_label, AVDTP_SINGLE_PACKET, AVDTP_RESPONSE_ACCEPT_MSG);
408     command[pos++] = (uint8_t)AVDTP_SI_DISCOVER;
409 
410     btstack_linked_list_iterator_t it;
411     btstack_linked_list_iterator_init(&it, (btstack_linked_list_t *) endpoints);
412     while (btstack_linked_list_iterator_has_next(&it)){
413         avdtp_stream_endpoint_t * stream_endpoint = (avdtp_stream_endpoint_t *)btstack_linked_list_iterator_next(&it);
414         command[pos++] = (stream_endpoint->sep.seid << 2) | (stream_endpoint->sep.in_use<<1);
415         command[pos++] = (stream_endpoint->sep.media_type << 4) | (stream_endpoint->sep.type << 3);
416     }
417     return l2cap_send(cid, command, pos);
418 }
419 
420 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){
421     uint8_t command[4];
422     command[0] = avdtp_header(transaction_label, AVDTP_SINGLE_PACKET, AVDTP_RESPONSE_REJECT_MSG);
423     command[1] = (uint8_t)identifier;
424     command[2] = category;
425     command[3] = error_code;
426     return l2cap_send(cid, command, sizeof(command));
427 }
428 
429 static int avdtp_acceptor_send_response_general_reject(uint16_t cid, avdtp_signal_identifier_t identifier, uint8_t transaction_label){
430     uint8_t command[2];
431     command[0] = avdtp_header(transaction_label, AVDTP_SINGLE_PACKET, AVDTP_GENERAL_REJECT_MSG);
432     command[1] = (uint8_t)identifier;
433     return l2cap_send(cid, command, sizeof(command));
434 }
435 
436 static int avdtp_acceptor_send_response_reject(uint16_t cid, avdtp_signal_identifier_t identifier, uint8_t transaction_label){
437     uint8_t command[2];
438     command[0] = avdtp_header(transaction_label, AVDTP_SINGLE_PACKET, AVDTP_RESPONSE_REJECT_MSG);
439     command[1] = (uint8_t)identifier;
440     return l2cap_send(cid, command, sizeof(command));
441 }
442 
443 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){
444     uint8_t command[3];
445     command[0] = avdtp_header(transaction_label, AVDTP_SINGLE_PACKET, AVDTP_RESPONSE_REJECT_MSG);
446     command[1] = (uint8_t)identifier;
447     command[2] = error_code;
448     return l2cap_send(cid, command, sizeof(command));
449 }
450 
451 void avdtp_acceptor_stream_config_subsm_run(avdtp_connection_t * connection, avdtp_context_t * context){
452     int sent = 1;
453     btstack_linked_list_t * stream_endpoints = &context->stream_endpoints;
454 
455     switch (connection->acceptor_connection_state){
456         case AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_ANSWER_DISCOVER_SEPS:
457             connection->state = AVDTP_SIGNALING_CONNECTION_OPENED;
458             connection->acceptor_connection_state = AVDTP_SIGNALING_CONNECTION_ACCEPTOR_IDLE;
459             avdtp_acceptor_send_seps_response(connection->l2cap_signaling_cid, connection->acceptor_transaction_label, (avdtp_stream_endpoint_t *) stream_endpoints);
460             break;
461         case AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_REJECT_WITH_ERROR_CODE:
462             connection->acceptor_connection_state = AVDTP_SIGNALING_CONNECTION_ACCEPTOR_IDLE;
463             avdtp_acceptor_send_response_reject_with_error_code(connection->l2cap_signaling_cid, connection->reject_signal_identifier, connection->error_code, connection->acceptor_transaction_label);
464             break;
465         case AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE:
466             connection->acceptor_connection_state = AVDTP_SIGNALING_CONNECTION_ACCEPTOR_IDLE;
467             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);
468             break;
469         case AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_GENERAL_REJECT_WITH_ERROR_CODE:
470             connection->acceptor_connection_state = AVDTP_SIGNALING_CONNECTION_ACCEPTOR_IDLE;
471             avdtp_acceptor_send_response_general_reject(connection->l2cap_signaling_cid, connection->reject_signal_identifier, connection->acceptor_transaction_label);
472         default:
473             sent = 0;
474             break;
475     }
476     if (sent){
477         log_info("    ACP: DONE");
478         return;
479     }
480 
481     avdtp_stream_endpoint_t * stream_endpoint = avdtp_stream_endpoint_for_seid(connection->query_seid, context);
482     if (!stream_endpoint) return;
483 
484     uint8_t reject_service_category = connection->reject_service_category;
485     avdtp_signal_identifier_t reject_signal_identifier = connection->reject_signal_identifier;
486     uint8_t error_code = connection->error_code;
487     uint16_t cid = stream_endpoint->connection ? stream_endpoint->connection->l2cap_signaling_cid : connection->l2cap_signaling_cid;
488     uint8_t trid = stream_endpoint->connection ? stream_endpoint->connection->acceptor_transaction_label : connection->acceptor_transaction_label;
489 
490     avdtp_acceptor_stream_endpoint_state_t acceptor_config_state = stream_endpoint->acceptor_config_state;
491     stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_STREAM_CONFIG_IDLE;
492     uint8_t * out_buffer;
493     uint16_t pos;
494 
495     int status = 0;
496     switch (acceptor_config_state){
497         case AVDTP_ACCEPTOR_STREAM_CONFIG_IDLE:
498             break;
499         case AVDTP_ACCEPTOR_W2_ANSWER_GET_CAPABILITIES:
500             avdtp_prepare_capabilities(&connection->signaling_packet, trid, stream_endpoint->sep.registered_service_categories, stream_endpoint->sep.capabilities, AVDTP_SI_GET_CAPABILITIES);
501             l2cap_reserve_packet_buffer();
502             out_buffer = l2cap_get_outgoing_buffer();
503             pos = avdtp_signaling_create_fragment(cid, &connection->signaling_packet, out_buffer);
504             if (connection->signaling_packet.packet_type != AVDTP_SINGLE_PACKET && connection->signaling_packet.packet_type != AVDTP_END_PACKET){
505                 stream_endpoint->acceptor_config_state = acceptor_config_state;
506                 log_info("    ACP: fragmented");
507             } else {
508                 log_info("    ACP:DONE");
509             }
510             l2cap_send_prepared(cid, pos);
511             break;
512         case AVDTP_ACCEPTOR_W2_ANSWER_GET_ALL_CAPABILITIES:
513             avdtp_prepare_capabilities(&connection->signaling_packet, trid, stream_endpoint->sep.registered_service_categories, stream_endpoint->sep.capabilities, AVDTP_SI_GET_ALL_CAPABILITIES);
514             l2cap_reserve_packet_buffer();
515             out_buffer = l2cap_get_outgoing_buffer();
516             pos = avdtp_signaling_create_fragment(cid, &connection->signaling_packet, out_buffer);
517             if (connection->signaling_packet.packet_type != AVDTP_SINGLE_PACKET && connection->signaling_packet.packet_type != AVDTP_END_PACKET){
518                 stream_endpoint->acceptor_config_state = acceptor_config_state;
519                 log_info("    ACP: fragmented");
520             } else {
521                 log_info("    ACP:DONE");
522             }
523             l2cap_send_prepared(cid, pos);
524             break;
525         case AVDTP_ACCEPTOR_W2_ANSWER_SET_CONFIGURATION:
526             log_info("    ACP: DONE");
527             log_info("    -> AVDTP_STREAM_ENDPOINT_CONFIGURED");
528             stream_endpoint->connection = connection;
529             stream_endpoint->state = AVDTP_STREAM_ENDPOINT_CONFIGURED;
530             // TODO: consider reconfiguration
531             avdtp_acceptor_send_accept_response(cid, trid, AVDTP_SI_SET_CONFIGURATION);
532             break;
533         case AVDTP_ACCEPTOR_W2_ANSWER_RECONFIGURE:
534             log_info("    ACP: DONE ");
535             avdtp_acceptor_send_accept_response(cid, trid, AVDTP_SI_RECONFIGURE);
536             break;
537 
538         case AVDTP_ACCEPTOR_W2_ANSWER_GET_CONFIGURATION:{
539             avdtp_sep_t sep = stream_endpoint->connection->remote_seps[stream_endpoint->remote_sep_index];
540             avdtp_prepare_capabilities(&connection->signaling_packet, trid, sep.configured_service_categories, sep.configuration, AVDTP_SI_GET_CONFIGURATION);
541             l2cap_reserve_packet_buffer();
542             out_buffer = l2cap_get_outgoing_buffer();
543             pos = avdtp_signaling_create_fragment(cid, &connection->signaling_packet, out_buffer);
544             if (connection->signaling_packet.packet_type != AVDTP_SINGLE_PACKET && connection->signaling_packet.packet_type != AVDTP_END_PACKET){
545                 stream_endpoint->acceptor_config_state = acceptor_config_state;
546                 log_info("    ACP: fragmented");
547             } else {
548                 log_info("    ACP:DONE");
549             }
550             l2cap_send_prepared(cid, pos);
551             break;
552         }
553         case AVDTP_ACCEPTOR_W2_ANSWER_OPEN_STREAM:
554             log_info("    ACP: DONE");
555             avdtp_acceptor_send_accept_response(cid, trid, AVDTP_SI_OPEN);
556             break;
557         case AVDTP_ACCEPTOR_W2_ANSWER_START_STREAM:
558             log_info("    ACP: DONE ");
559             log_info("    -> AVDTP_STREAM_ENDPOINT_STREAMING ");
560             stream_endpoint->state = AVDTP_STREAM_ENDPOINT_STREAMING;
561             avdtp_acceptor_send_accept_response(cid, trid, AVDTP_SI_START);
562             break;
563         case AVDTP_ACCEPTOR_W2_ANSWER_CLOSE_STREAM:
564             log_info("    ACP: DONE");
565             avdtp_acceptor_send_accept_response(cid, trid, AVDTP_SI_CLOSE);
566             break;
567         case AVDTP_ACCEPTOR_W2_ANSWER_ABORT_STREAM:
568             log_info("    ACP: DONE");
569             avdtp_acceptor_send_accept_response(cid, trid, AVDTP_SI_ABORT);
570             break;
571         case AVDTP_ACCEPTOR_W2_ANSWER_SUSPEND_STREAM:
572             log_info("    ACP: DONE");
573             stream_endpoint->state = AVDTP_STREAM_ENDPOINT_OPENED;
574             avdtp_acceptor_send_accept_response(cid, trid, AVDTP_SI_SUSPEND);
575             break;
576         case AVDTP_ACCEPTOR_W2_REJECT_UNKNOWN_CMD:
577             status = 1;
578             log_info("    ACP: DONE REJECT");
579             connection->reject_signal_identifier = 0;
580             avdtp_acceptor_send_response_reject(cid, reject_signal_identifier, trid);
581             break;
582         case AVDTP_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE:
583             status = 1;
584             log_info("    ACP: DONE REJECT CATEGORY");
585             connection->reject_service_category = 0;
586             avdtp_acceptor_send_response_reject_service_category(cid, reject_signal_identifier, reject_service_category, error_code, trid);
587             break;
588 
589         case AVDTP_ACCEPTOR_W2_REJECT_WITH_ERROR_CODE:
590             status = 1;
591             log_info("    ACP: DONE REJECT");
592             connection->reject_signal_identifier = 0;
593             connection->error_code = 0;
594             avdtp_acceptor_send_response_reject_with_error_code(cid, reject_signal_identifier, error_code, trid);
595             break;
596         default:
597             status = 0;
598             log_info("    ACP: NOT IMPLEMENTED");
599             sent = 0;
600     }
601     avdtp_signaling_emit_accept(context->avdtp_callback, connection->con_handle, connection->int_seid, connection->signaling_packet.signal_identifier, status);
602 
603     // check fragmentation
604     if (connection->signaling_packet.packet_type != AVDTP_SINGLE_PACKET && connection->signaling_packet.packet_type != AVDTP_END_PACKET){
605         avdtp_request_can_send_now_acceptor(connection, connection->l2cap_signaling_cid);
606     }
607 }
608