xref: /btstack/src/classic/avdtp_acceptor.c (revision ff3cc4a5378c2f681cc9b75cf54d154a12a3051e)
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     (void)memcpy(signaling_packet->command + signaling_packet->size, packet,
59                  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, avdtp_context_t * context){
85     avdtp_stream_endpoint_t * stream_endpoint;
86     connection->acceptor_transaction_label = connection->signaling_packet.transaction_label;
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     // handle error cases
96     switch (connection->signaling_packet.signal_identifier){
97         case AVDTP_SI_DISCOVER:
98             if (connection->state != AVDTP_SIGNALING_CONNECTION_OPENED) return;
99             log_info("ACP: AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_ANSWER_DISCOVER_SEPS");
100             connection->acceptor_connection_state = AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_ANSWER_DISCOVER_SEPS;
101             avdtp_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         case AVDTP_SI_DELAYREPORT:
113             connection->local_seid  = packet[offset++] >> 2;
114             stream_endpoint = avdtp_stream_endpoint_with_seid(connection->local_seid, context);
115             if (!stream_endpoint){
116                 log_info("ACP: cmd %d - RESPONSE REJECT", connection->signaling_packet.signal_identifier);
117                 connection->error_code = BAD_ACP_SEID;
118                 if (connection->signaling_packet.signal_identifier == AVDTP_SI_OPEN){
119                     connection->error_code = BAD_STATE;
120                 }
121 
122                 connection->acceptor_connection_state = AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_REJECT_WITH_ERROR_CODE;
123                 if (connection->signaling_packet.signal_identifier == AVDTP_SI_RECONFIGURE){
124                     connection->reject_service_category = connection->local_seid;
125                     connection->acceptor_connection_state = AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE;
126                 }
127                 connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
128                 avdtp_request_can_send_now_acceptor(connection, connection->l2cap_signaling_cid);
129                 return;
130             }
131             break;
132 
133         case AVDTP_SI_SUSPEND:{
134             int i;
135             log_info("ACP: AVDTP_SI_SUSPEND seids: ");
136             connection->num_suspended_seids = 0;
137 
138             for (i = offset; i < size; i++){
139                 connection->suspended_seids[connection->num_suspended_seids] = packet[i] >> 2;
140                 offset++;
141                 log_info("%d, ", connection->suspended_seids[connection->num_suspended_seids]);
142                 connection->num_suspended_seids++;
143             }
144 
145             if (connection->num_suspended_seids == 0) {
146                 log_info("ACP: CATEGORY RESPONSE REJECT BAD_ACP_SEID");
147                 connection->error_code = BAD_ACP_SEID;
148                 connection->reject_service_category = connection->local_seid;
149                 connection->acceptor_connection_state = AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE;
150                 connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
151                 avdtp_request_can_send_now_acceptor(connection, connection->l2cap_signaling_cid);
152                 return;
153             }
154             // deal with first susspended seid
155             connection->local_seid = connection->suspended_seids[0];
156             stream_endpoint = avdtp_stream_endpoint_with_seid(connection->local_seid, context);
157             if (!stream_endpoint){
158                 log_info("ACP: stream_endpoint not found, CATEGORY RESPONSE REJECT BAD_ACP_SEID");
159                 connection->error_code = BAD_ACP_SEID;
160                 connection->reject_service_category = connection->local_seid;
161                 connection->acceptor_connection_state = AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE;
162                 connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
163                 connection->num_suspended_seids = 0;
164                 avdtp_request_can_send_now_acceptor(connection, connection->l2cap_signaling_cid);
165                 return;
166             }
167             break;
168         }
169         default:
170             connection->acceptor_connection_state = AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_GENERAL_REJECT_WITH_ERROR_CODE;
171             connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
172             log_info("AVDTP_CMD_MSG signal %d not implemented, general reject", connection->signaling_packet.signal_identifier);
173             avdtp_request_can_send_now_acceptor(connection, connection->l2cap_signaling_cid);
174             return;
175     }
176 
177     if (!stream_endpoint) {
178         return;
179     }
180 
181     if (!avdtp_acceptor_process_chunk(&connection->signaling_packet, packet, size)) return;
182 
183     uint16_t packet_size = connection->signaling_packet.size;
184     connection->signaling_packet.size = 0;
185 
186     int request_to_send = 1;
187     switch (stream_endpoint->acceptor_config_state){
188         case AVDTP_ACCEPTOR_STREAM_CONFIG_IDLE:
189             switch (connection->signaling_packet.signal_identifier){
190                 case AVDTP_SI_DELAYREPORT:
191                     log_info("ACP: AVDTP_ACCEPTOR_W2_ANSWER_DELAY_REPORT");
192                     stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_ANSWER_DELAY_REPORT;
193                     avdtp_signaling_emit_delay(context->avdtp_callback, connection->avdtp_cid, connection->local_seid, big_endian_read_16(packet, offset));
194                     break;
195 
196                 case AVDTP_SI_GET_ALL_CAPABILITIES:
197                     log_info("ACP: AVDTP_SI_GET_ALL_CAPABILITIES");
198                     stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_ANSWER_GET_ALL_CAPABILITIES;
199                     break;
200                 case AVDTP_SI_GET_CAPABILITIES:
201                     log_info("ACP: AVDTP_ACCEPTOR_W2_ANSWER_GET_CAPABILITIES");
202                     stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_ANSWER_GET_CAPABILITIES;
203                     break;
204                 case AVDTP_SI_SET_CONFIGURATION:{
205                     // log_info("acceptor SM received SET_CONFIGURATION cmd: role is_initiator %d", connection->is_initiator);
206                     if (connection->is_initiator){
207                         if (connection->is_configuration_initiated_locally){
208                             log_info("ACP: Set configuration already initiated locally, reject cmd ");
209                             // fire configuration parsing errors
210                             connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
211                             stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_UNKNOWN_CMD;
212                             connection->is_initiator = 1;
213                             break;
214                         }
215                         connection->is_initiator = 0;
216                         log_info("acceptor SM received SET_CONFIGURATION cmd: change role to acceptor, is_initiator %d", connection->is_initiator);
217                     }
218 
219                     log_info("ACP: AVDTP_ACCEPTOR_W2_ANSWER_SET_CONFIGURATION connection %p", connection);
220                     stream_endpoint->state = AVDTP_STREAM_ENDPOINT_CONFIGURATION_SUBSTATEMACHINE;
221                     stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_ANSWER_SET_CONFIGURATION;
222                     connection->reject_service_category = 0;
223                     stream_endpoint->connection = connection;
224                     avdtp_sep_t sep;
225                     sep.seid = connection->signaling_packet.command[offset++] >> 2;
226                     sep.configured_service_categories = avdtp_unpack_service_capabilities(connection, &sep.configuration, connection->signaling_packet.command+offset, packet_size-offset);
227                     sep.in_use = 1;
228 
229                     if (connection->error_code){
230                         log_info("fire configuration parsing errors ");
231                         connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
232                         stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE;
233                         break;
234                     }
235                     // find or add sep
236 
237                     log_info("ACP .. seid %d, remote sep seid %d", sep.seid, stream_endpoint->remote_sep.seid);
238 
239                     if (is_avdtp_remote_seid_registered(stream_endpoint)){
240                         if (stream_endpoint->remote_sep.in_use){
241                             log_info("reject as it is already in use");
242                             connection->error_code = SEP_IN_USE;
243                             // find first registered category and fire the error
244                             connection->reject_service_category = 0;
245                             int i;
246                             for (i = 1; i < 9; i++){
247                                 if (get_bit16(sep.configured_service_categories, i)){
248                                     connection->reject_service_category = i;
249                                     break;
250                                 }
251                             }
252                             connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
253                             stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE;
254                         } else {
255                             stream_endpoint->remote_sep = sep;
256                             log_info("ACP: update seid %d, to %p", stream_endpoint->remote_sep.seid, stream_endpoint);
257                         }
258                     } else {
259                         // add new
260                         log_info("ACP: seid %d not found in %p", sep.seid, stream_endpoint);
261                         stream_endpoint->remote_sep = sep;
262                         log_info("ACP: add seid %d, to %p", stream_endpoint->remote_sep.seid, stream_endpoint);
263                     }
264 
265                     avdtp_emit_configuration(context->avdtp_callback, connection->avdtp_cid, avdtp_local_seid(stream_endpoint), avdtp_remote_seid(stream_endpoint), &sep.configuration, sep.configured_service_categories);
266                     avdtp_signaling_emit_accept(context->avdtp_callback, connection->avdtp_cid, avdtp_local_seid(stream_endpoint), connection->signaling_packet.signal_identifier);
267                     break;
268                 }
269                 case AVDTP_SI_RECONFIGURE:{
270                     stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_ANSWER_RECONFIGURE;
271                     connection->reject_service_category = 0;
272 
273                     avdtp_sep_t sep;
274                     sep.seid = connection->local_seid;
275                     log_info("ACP: AVDTP_ACCEPTOR_W2_ANSWER_RECONFIGURE seid %d", sep.seid);
276                     sep.configured_service_categories = avdtp_unpack_service_capabilities(connection, &sep.configuration, connection->signaling_packet.command+offset, packet_size-offset);
277                     if (connection->error_code){
278                         // fire configuration parsing errors
279                         connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
280                         stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE;
281                         break;
282                     }
283 
284                     // find sep or raise error
285                     if (!is_avdtp_remote_seid_registered(stream_endpoint)){
286                         log_info("ACP: REJECT AVDTP_SI_RECONFIGURE, BAD_ACP_SEID");
287                         stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE;
288                         connection->error_code = BAD_ACP_SEID;
289                         connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
290                         break;
291                     }
292                     stream_endpoint->remote_sep = sep;
293                     log_info("ACP: update seid %d, to %p", stream_endpoint->remote_sep.seid, stream_endpoint);
294 
295                     avdtp_emit_configuration(context->avdtp_callback, connection->avdtp_cid, avdtp_local_seid(stream_endpoint), avdtp_remote_seid(stream_endpoint), &sep.configuration, sep.configured_service_categories);
296                     avdtp_signaling_emit_accept(context->avdtp_callback, connection->avdtp_cid, avdtp_local_seid(stream_endpoint), connection->signaling_packet.signal_identifier);
297                     break;
298                 }
299 
300                 case AVDTP_SI_GET_CONFIGURATION:
301                     log_info("ACP: AVDTP_ACCEPTOR_W2_ANSWER_GET_CONFIGURATION");
302                     stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_ANSWER_GET_CONFIGURATION;
303                     break;
304                 case AVDTP_SI_OPEN:
305                     if (stream_endpoint->state != AVDTP_STREAM_ENDPOINT_CONFIGURED){
306                         log_info("ACP: REJECT AVDTP_SI_OPEN, BAD_STATE");
307                         stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_WITH_ERROR_CODE;
308                         connection->error_code = BAD_STATE;
309                         connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
310                         break;
311                     }
312                     log_info("ACP: AVDTP_STREAM_ENDPOINT_W2_ANSWER_OPEN_STREAM");
313                     stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_ANSWER_OPEN_STREAM;
314                     stream_endpoint->state = AVDTP_STREAM_ENDPOINT_W4_L2CAP_FOR_MEDIA_CONNECTED;
315                     connection->local_seid = stream_endpoint->sep.seid;
316                     break;
317                 case AVDTP_SI_START:
318                     if (stream_endpoint->state != AVDTP_STREAM_ENDPOINT_OPENED){
319                         log_info("ACP: REJECT AVDTP_SI_START, BAD_STATE, state %d", stream_endpoint->state);
320                         stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE;
321                         connection->error_code = BAD_STATE;
322                         connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
323                         break;
324                     }
325                     log_info("ACP: AVDTP_ACCEPTOR_W2_ANSWER_START_STREAM");
326                     stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_ANSWER_START_STREAM;
327                     break;
328                 case AVDTP_SI_CLOSE:
329                     switch (stream_endpoint->state){
330                         case AVDTP_STREAM_ENDPOINT_OPENED:
331                         case AVDTP_STREAM_ENDPOINT_STREAMING:
332                             log_info("ACP: AVDTP_ACCEPTOR_W2_ANSWER_CLOSE_STREAM");
333                             stream_endpoint->state = AVDTP_STREAM_ENDPOINT_CLOSING;
334                             stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_ANSWER_CLOSE_STREAM;
335                             break;
336                         default:
337                             log_info("ACP: AVDTP_SI_CLOSE, bad state %d ", stream_endpoint->state);
338                             stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_WITH_ERROR_CODE;
339                             connection->error_code = BAD_STATE;
340                             connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
341                             break;
342                     }
343                     break;
344                 case AVDTP_SI_ABORT:
345                      switch (stream_endpoint->state){
346                         case AVDTP_STREAM_ENDPOINT_CONFIGURED:
347                         case AVDTP_STREAM_ENDPOINT_CLOSING:
348                         case AVDTP_STREAM_ENDPOINT_OPENED:
349                         case AVDTP_STREAM_ENDPOINT_STREAMING:
350                             log_info("ACP: AVDTP_ACCEPTOR_W2_ANSWER_ABORT_STREAM");
351                             stream_endpoint->state = AVDTP_STREAM_ENDPOINT_ABORTING;
352                             stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_ANSWER_ABORT_STREAM;
353                             break;
354                         default:
355                             log_info("ACP: AVDTP_SI_ABORT, bad state %d ", stream_endpoint->state);
356                             stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_WITH_ERROR_CODE;
357                             connection->error_code = BAD_STATE;
358                             connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
359                             break;
360                     }
361                     break;
362                 case AVDTP_SI_SUSPEND:
363                     log_info(" entering AVDTP_SI_SUSPEND");
364                     switch (stream_endpoint->state){
365                         case AVDTP_STREAM_ENDPOINT_OPENED:
366                         case AVDTP_STREAM_ENDPOINT_STREAMING:
367                             stream_endpoint->state = AVDTP_STREAM_ENDPOINT_OPENED;
368                             connection->num_suspended_seids--;
369                             if (connection->num_suspended_seids <= 0){
370                                 log_info("ACP: AVDTP_ACCEPTOR_W2_ANSWER_SUSPEND_STREAM");
371                                 stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_ANSWER_SUSPEND_STREAM;
372                             }
373                             break;
374                         default:
375                             log_info("ACP: AVDTP_SI_SUSPEND, bad state ");
376                             stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE;
377                             connection->error_code = BAD_STATE;
378                             connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
379                             break;
380                     }
381 
382                     //stream_endpoint->state = AVDTP_STREAM_ENDPOINT_SUSPENDING;
383                     //stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_SUSPEND_STREAM;
384                     break;
385                 default:
386                     log_info("ACP: NOT IMPLEMENTED, Reject signal_identifier %02x", connection->signaling_packet.signal_identifier);
387                     stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_UNKNOWN_CMD;
388                     connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
389                     break;
390             }
391             break;
392         default:
393             return;
394     }
395 
396     if (!request_to_send){
397         log_info("ACP: NOT IMPLEMENTED");
398     }
399     avdtp_request_can_send_now_acceptor(connection, connection->l2cap_signaling_cid);
400 }
401 
402 static int avdtp_acceptor_send_seps_response(uint16_t cid, uint8_t transaction_label, avdtp_stream_endpoint_t * endpoints){
403     uint8_t command[2+2*AVDTP_MAX_NUM_SEPS];
404     int pos = 0;
405     command[pos++] = avdtp_header(transaction_label, AVDTP_SINGLE_PACKET, AVDTP_RESPONSE_ACCEPT_MSG);
406     command[pos++] = (uint8_t)AVDTP_SI_DISCOVER;
407 
408     btstack_linked_list_iterator_t it;
409     btstack_linked_list_iterator_init(&it, (btstack_linked_list_t *) endpoints);
410     while (btstack_linked_list_iterator_has_next(&it)){
411         avdtp_stream_endpoint_t * stream_endpoint = (avdtp_stream_endpoint_t *)btstack_linked_list_iterator_next(&it);
412         command[pos++] = (stream_endpoint->sep.seid << 2) | (stream_endpoint->sep.in_use<<1);
413         command[pos++] = (stream_endpoint->sep.media_type << 4) | (stream_endpoint->sep.type << 3);
414     }
415     return l2cap_send(cid, command, pos);
416 }
417 
418 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){
419     uint8_t command[4];
420     command[0] = avdtp_header(transaction_label, AVDTP_SINGLE_PACKET, AVDTP_RESPONSE_REJECT_MSG);
421     command[1] = (uint8_t)identifier;
422     command[2] = category;
423     command[3] = error_code;
424     return l2cap_send(cid, command, sizeof(command));
425 }
426 
427 static int avdtp_acceptor_send_response_general_reject(uint16_t cid, avdtp_signal_identifier_t identifier, uint8_t transaction_label){
428     uint8_t command[2];
429     command[0] = avdtp_header(transaction_label, AVDTP_SINGLE_PACKET, AVDTP_GENERAL_REJECT_MSG);
430     command[1] = (uint8_t)identifier;
431     return l2cap_send(cid, command, sizeof(command));
432 }
433 
434 static int avdtp_acceptor_send_response_reject(uint16_t cid, avdtp_signal_identifier_t identifier, uint8_t transaction_label){
435     uint8_t command[2];
436     command[0] = avdtp_header(transaction_label, AVDTP_SINGLE_PACKET, AVDTP_RESPONSE_REJECT_MSG);
437     command[1] = (uint8_t)identifier;
438     return l2cap_send(cid, command, sizeof(command));
439 }
440 
441 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){
442     uint8_t command[3];
443     command[0] = avdtp_header(transaction_label, AVDTP_SINGLE_PACKET, AVDTP_RESPONSE_REJECT_MSG);
444     command[1] = (uint8_t)identifier;
445     command[2] = error_code;
446     return l2cap_send(cid, command, sizeof(command));
447 }
448 
449 void avdtp_acceptor_stream_config_subsm_run(avdtp_connection_t * connection, avdtp_context_t * context){
450     int sent = 1;
451     btstack_linked_list_t * stream_endpoints = &context->stream_endpoints;
452 
453     switch (connection->acceptor_connection_state){
454         case AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_ANSWER_DISCOVER_SEPS:
455             connection->state = AVDTP_SIGNALING_CONNECTION_OPENED;
456             connection->acceptor_connection_state = AVDTP_SIGNALING_CONNECTION_ACCEPTOR_IDLE;
457             avdtp_acceptor_send_seps_response(connection->l2cap_signaling_cid, connection->acceptor_transaction_label, (avdtp_stream_endpoint_t *) stream_endpoints);
458             break;
459         case AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_REJECT_WITH_ERROR_CODE:
460             connection->acceptor_connection_state = AVDTP_SIGNALING_CONNECTION_ACCEPTOR_IDLE;
461             avdtp_acceptor_send_response_reject_with_error_code(connection->l2cap_signaling_cid, connection->reject_signal_identifier, connection->error_code, connection->acceptor_transaction_label);
462             break;
463         case AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE:
464             connection->acceptor_connection_state = AVDTP_SIGNALING_CONNECTION_ACCEPTOR_IDLE;
465             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);
466             break;
467         case AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_GENERAL_REJECT_WITH_ERROR_CODE:
468             connection->acceptor_connection_state = AVDTP_SIGNALING_CONNECTION_ACCEPTOR_IDLE;
469             avdtp_acceptor_send_response_general_reject(connection->l2cap_signaling_cid, connection->reject_signal_identifier, connection->acceptor_transaction_label);
470             break;
471         default:
472             sent = 0;
473             break;
474     }
475     if (sent){
476         log_info("ACP: DONE");
477         return;
478     }
479 
480     avdtp_stream_endpoint_t * stream_endpoint = avdtp_stream_endpoint_for_seid(connection->local_seid, context);
481     if (!stream_endpoint) return;
482 
483     uint8_t reject_service_category = connection->reject_service_category;
484     avdtp_signal_identifier_t reject_signal_identifier = connection->reject_signal_identifier;
485     uint8_t error_code = connection->error_code;
486     uint16_t cid = stream_endpoint->connection ? stream_endpoint->connection->l2cap_signaling_cid : connection->l2cap_signaling_cid;
487     uint8_t trid = stream_endpoint->connection ? stream_endpoint->connection->acceptor_transaction_label : connection->acceptor_transaction_label;
488 
489     avdtp_acceptor_stream_endpoint_state_t acceptor_config_state = stream_endpoint->acceptor_config_state;
490     stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_STREAM_CONFIG_IDLE;
491     uint8_t * out_buffer;
492     uint16_t pos;
493 
494     switch (acceptor_config_state){
495         case AVDTP_ACCEPTOR_STREAM_CONFIG_IDLE:
496             break;
497         case AVDTP_ACCEPTOR_W2_ANSWER_GET_CAPABILITIES:
498             avdtp_prepare_capabilities(&connection->signaling_packet, trid, stream_endpoint->sep.registered_service_categories, stream_endpoint->sep.capabilities, AVDTP_SI_GET_CAPABILITIES);
499             l2cap_reserve_packet_buffer();
500             out_buffer = l2cap_get_outgoing_buffer();
501             pos = avdtp_signaling_create_fragment(cid, &connection->signaling_packet, out_buffer);
502             if ((connection->signaling_packet.packet_type != AVDTP_SINGLE_PACKET) && (connection->signaling_packet.packet_type != AVDTP_END_PACKET)){
503                 stream_endpoint->acceptor_config_state = acceptor_config_state;
504                 log_info("ACP: fragmented");
505             } else {
506                 log_info("ACP:DONE");
507             }
508             l2cap_send_prepared(cid, pos);
509             break;
510         case AVDTP_ACCEPTOR_W2_ANSWER_DELAY_REPORT:
511             log_info("ACP: DONE ");
512             avdtp_acceptor_send_accept_response(cid, trid, AVDTP_SI_DELAYREPORT);
513             break;
514         case AVDTP_ACCEPTOR_W2_ANSWER_GET_ALL_CAPABILITIES:
515             avdtp_prepare_capabilities(&connection->signaling_packet, trid, stream_endpoint->sep.registered_service_categories, stream_endpoint->sep.capabilities, AVDTP_SI_GET_ALL_CAPABILITIES);
516             l2cap_reserve_packet_buffer();
517             out_buffer = l2cap_get_outgoing_buffer();
518             pos = avdtp_signaling_create_fragment(cid, &connection->signaling_packet, out_buffer);
519             if ((connection->signaling_packet.packet_type != AVDTP_SINGLE_PACKET) && (connection->signaling_packet.packet_type != AVDTP_END_PACKET)){
520                 stream_endpoint->acceptor_config_state = acceptor_config_state;
521                 log_info("ACP: fragmented");
522             } else {
523                 log_info("ACP:DONE");
524             }
525             l2cap_send_prepared(cid, pos);
526             break;
527         case AVDTP_ACCEPTOR_W2_ANSWER_SET_CONFIGURATION:
528             log_info("ACP: DONE");
529             log_info("    -> AVDTP_STREAM_ENDPOINT_CONFIGURED");
530             stream_endpoint->connection = connection;
531             stream_endpoint->state = AVDTP_STREAM_ENDPOINT_CONFIGURED;
532             // TODO: consider reconfiguration
533             avdtp_acceptor_send_accept_response(cid, trid, AVDTP_SI_SET_CONFIGURATION);
534             break;
535         case AVDTP_ACCEPTOR_W2_ANSWER_RECONFIGURE:
536             log_info("ACP: DONE ");
537             avdtp_acceptor_send_accept_response(cid, trid, AVDTP_SI_RECONFIGURE);
538             break;
539 
540         case AVDTP_ACCEPTOR_W2_ANSWER_GET_CONFIGURATION:{
541             avdtp_sep_t sep = stream_endpoint->remote_sep;
542             avdtp_prepare_capabilities(&connection->signaling_packet, trid, sep.configured_service_categories, sep.configuration, AVDTP_SI_GET_CONFIGURATION);
543             l2cap_reserve_packet_buffer();
544             out_buffer = l2cap_get_outgoing_buffer();
545             pos = avdtp_signaling_create_fragment(cid, &connection->signaling_packet, out_buffer);
546             if ((connection->signaling_packet.packet_type != AVDTP_SINGLE_PACKET) && (connection->signaling_packet.packet_type != AVDTP_END_PACKET)){
547                 stream_endpoint->acceptor_config_state = acceptor_config_state;
548                 log_info("ACP: fragmented");
549             } else {
550                 log_info("ACP:DONE");
551             }
552             l2cap_send_prepared(cid, pos);
553             break;
554         }
555         case AVDTP_ACCEPTOR_W2_ANSWER_OPEN_STREAM:
556             log_info("ACP: DONE");
557             avdtp_acceptor_send_accept_response(cid, trid, AVDTP_SI_OPEN);
558             break;
559         case AVDTP_ACCEPTOR_W2_ANSWER_START_STREAM:
560             log_info("ACP: DONE ");
561             log_info("    -> AVDTP_STREAM_ENDPOINT_STREAMING ");
562             stream_endpoint->state = AVDTP_STREAM_ENDPOINT_STREAMING;
563             avdtp_acceptor_send_accept_response(cid, trid, AVDTP_SI_START);
564             break;
565         case AVDTP_ACCEPTOR_W2_ANSWER_CLOSE_STREAM:
566             log_info("ACP: DONE");
567             avdtp_acceptor_send_accept_response(cid, trid, AVDTP_SI_CLOSE);
568             break;
569         case AVDTP_ACCEPTOR_W2_ANSWER_ABORT_STREAM:
570             log_info("ACP: DONE");
571             avdtp_acceptor_send_accept_response(cid, trid, AVDTP_SI_ABORT);
572             break;
573         case AVDTP_ACCEPTOR_W2_ANSWER_SUSPEND_STREAM:
574             log_info("ACP: DONE");
575             stream_endpoint->state = AVDTP_STREAM_ENDPOINT_OPENED;
576             avdtp_acceptor_send_accept_response(cid, trid, AVDTP_SI_SUSPEND);
577             break;
578         case AVDTP_ACCEPTOR_W2_REJECT_UNKNOWN_CMD:
579             log_info("ACP: DONE REJECT");
580             connection->reject_signal_identifier = AVDTP_SI_NONE;
581             avdtp_acceptor_send_response_reject(cid, reject_signal_identifier, trid);
582             break;
583         case AVDTP_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE:
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         case AVDTP_ACCEPTOR_W2_REJECT_WITH_ERROR_CODE:
589             log_info("ACP: DONE REJECT");
590             connection->reject_signal_identifier = AVDTP_SI_NONE;
591             connection->error_code = 0;
592             avdtp_acceptor_send_response_reject_with_error_code(cid, reject_signal_identifier, error_code, trid);
593             break;
594         default:
595             log_info("ACP: NOT IMPLEMENTED");
596             sent = 0;
597             break;
598     }
599     avdtp_signaling_emit_accept(context->avdtp_callback, connection->avdtp_cid, avdtp_local_seid(stream_endpoint), connection->signaling_packet.signal_identifier);
600     // check fragmentation
601     if ((connection->signaling_packet.packet_type != AVDTP_SINGLE_PACKET) && (connection->signaling_packet.packet_type != AVDTP_END_PACKET)){
602         avdtp_request_can_send_now_acceptor(connection, connection->l2cap_signaling_cid);
603     }
604 }
605