xref: /btstack/src/classic/avdtp_acceptor.c (revision 3e3fbf3df68dce1ab27af5efcdf0ea980eb93f6c)
1 /*
2  * Copyright (C) 2016 BlueKitchen GmbH
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the copyright holders nor the names of
14  *    contributors may be used to endorse or promote products derived
15  *    from this software without specific prior written permission.
16  * 4. Any redistribution, use, or modification is done solely for
17  *    personal benefit and not for any commercial purpose or for
18  *    monetary gain.
19  *
20  * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS
24  * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
27  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
30  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * Please inquire about commercial licensing options at
34  * [email protected]
35  *
36  */
37 
38 #define __BTSTACK_FILE__ "avdtp_acceptor.c"
39 
40 
41 #include <stdint.h>
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <string.h>
45 #include <unistd.h>
46 
47 #include "btstack.h"
48 #include "avdtp.h"
49 #include "avdtp_util.h"
50 #include "avdtp_acceptor.h"
51 
52 
53 static int avdtp_acceptor_send_accept_response(uint16_t cid,  uint8_t transaction_label, avdtp_signal_identifier_t identifier){
54     uint8_t command[2];
55     command[0] = avdtp_header(transaction_label, AVDTP_SINGLE_PACKET, AVDTP_RESPONSE_ACCEPT_MSG);
56     command[1] = (uint8_t)identifier;
57     return l2cap_send(cid, command, sizeof(command));
58 }
59 
60 static int avdtp_acceptor_process_chunk(avdtp_signaling_packet_t * signaling_packet, uint8_t * packet, uint16_t size){
61     memcpy(signaling_packet->command + signaling_packet->size, packet, size);
62     signaling_packet->size += size;
63     return signaling_packet->packet_type == AVDTP_SINGLE_PACKET || signaling_packet->packet_type == AVDTP_END_PACKET;
64 }
65 
66 static int avdtp_acceptor_validate_msg_length(avdtp_signal_identifier_t signal_identifier, uint16_t msg_size){
67     int minimal_msg_lenght = 2;
68     switch (signal_identifier){
69         case AVDTP_SI_GET_CAPABILITIES:
70         case AVDTP_SI_GET_ALL_CAPABILITIES:
71         case AVDTP_SI_SET_CONFIGURATION:
72         case AVDTP_SI_GET_CONFIGURATION:
73         case AVDTP_SI_START:
74         case AVDTP_SI_CLOSE:
75         case AVDTP_SI_ABORT:
76         case AVDTP_SI_RECONFIGURE:
77         case AVDTP_SI_OPEN:
78             minimal_msg_lenght = 3;
79             break;
80         default:
81             break;
82         }
83     return msg_size >= minimal_msg_lenght;
84 }
85 
86 void avdtp_acceptor_stream_config_subsm(avdtp_connection_t * connection, uint8_t * packet, uint16_t size, int offset, avdtp_context_t * context){
87     avdtp_stream_endpoint_t * stream_endpoint;
88     connection->acceptor_transaction_label = connection->signaling_packet.transaction_label;
89 
90     if (!avdtp_acceptor_validate_msg_length(connection->signaling_packet.signal_identifier, size)) {
91         connection->error_code = BAD_LENGTH;
92         connection->acceptor_connection_state = AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_REJECT_WITH_ERROR_CODE;
93         connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
94         avdtp_request_can_send_now_acceptor(connection, connection->l2cap_signaling_cid);
95         return;
96     }
97 
98     switch (connection->signaling_packet.signal_identifier){
99         case AVDTP_SI_DISCOVER:
100             if (connection->state != AVDTP_SIGNALING_CONNECTION_OPENED) return;
101             log_info("    ACP: AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_ANSWER_DISCOVER_SEPS");
102             connection->acceptor_connection_state = AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_ANSWER_DISCOVER_SEPS;
103             avdtp_request_can_send_now_acceptor(connection, connection->l2cap_signaling_cid);
104             return;
105         case AVDTP_SI_GET_CAPABILITIES:
106         case AVDTP_SI_GET_ALL_CAPABILITIES:
107         case AVDTP_SI_SET_CONFIGURATION:
108         case AVDTP_SI_GET_CONFIGURATION:
109         case AVDTP_SI_START:
110         case AVDTP_SI_CLOSE:
111         case AVDTP_SI_ABORT:
112         case AVDTP_SI_OPEN:
113         case AVDTP_SI_RECONFIGURE:
114             connection->query_seid  = packet[offset++] >> 2;
115             stream_endpoint = avdtp_stream_endpoint_with_seid(connection->query_seid, context);
116             if (!stream_endpoint){
117                 log_info("    ACP: cmd %d - RESPONSE REJECT", connection->signaling_packet.signal_identifier);
118                 connection->error_code = BAD_ACP_SEID;
119                 if (connection->signaling_packet.signal_identifier == AVDTP_SI_OPEN){
120                     connection->error_code = BAD_STATE;
121                 }
122 
123                 connection->acceptor_connection_state = AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_REJECT_WITH_ERROR_CODE;
124                 if (connection->signaling_packet.signal_identifier == AVDTP_SI_RECONFIGURE){
125                     connection->reject_service_category = connection->query_seid;
126                     connection->acceptor_connection_state = AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE;
127                 }
128                 connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
129                 avdtp_request_can_send_now_acceptor(connection, connection->l2cap_signaling_cid);
130                 return;
131             }
132             break;
133 
134         case AVDTP_SI_SUSPEND:{
135             int i;
136             log_info("    ACP: AVDTP_SI_SUSPEND seids: ");
137             connection->num_suspended_seids = 0;
138 
139             for (i = offset; i < size; i++){
140                 connection->suspended_seids[connection->num_suspended_seids] = packet[i] >> 2;
141                 offset++;
142                 log_info("%d, ", connection->suspended_seids[connection->num_suspended_seids]);
143                 connection->num_suspended_seids++;
144             }
145 
146             if (connection->num_suspended_seids == 0) {
147                 log_info("    ACP: CATEGORY RESPONSE REJECT BAD_ACP_SEID");
148                 connection->error_code = BAD_ACP_SEID;
149                 connection->reject_service_category = connection->query_seid;
150                 connection->acceptor_connection_state = AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE;
151                 connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
152                 avdtp_request_can_send_now_acceptor(connection, connection->l2cap_signaling_cid);
153                 return;
154             }
155             // deal with first susspended seid
156             connection->query_seid = connection->suspended_seids[0];
157             stream_endpoint = avdtp_stream_endpoint_with_seid(connection->query_seid, context);
158             if (!stream_endpoint){
159                 log_info("    ACP: stream_endpoint not found, CATEGORY RESPONSE REJECT BAD_ACP_SEID");
160                 connection->error_code = BAD_ACP_SEID;
161                 connection->reject_service_category = connection->query_seid;
162                 connection->acceptor_connection_state = AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE;
163                 connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
164                 connection->num_suspended_seids = 0;
165                 avdtp_request_can_send_now_acceptor(connection, connection->l2cap_signaling_cid);
166                 return;
167             }
168             break;
169         }
170         default:
171             connection->acceptor_connection_state = AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_GENERAL_REJECT_WITH_ERROR_CODE;
172             connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
173             log_info("AVDTP_CMD_MSG signal %d not implemented, general reject", connection->signaling_packet.signal_identifier);
174             avdtp_request_can_send_now_acceptor(connection, connection->l2cap_signaling_cid);
175             return;
176     }
177 
178     if (!stream_endpoint) {
179         return;
180     }
181 
182     if (!avdtp_acceptor_process_chunk(&connection->signaling_packet, packet, size)) return;
183 
184     uint16_t packet_size = connection->signaling_packet.size;
185     connection->signaling_packet.size = 0;
186 
187     int request_to_send = 1;
188     switch (stream_endpoint->acceptor_config_state){
189         case AVDTP_ACCEPTOR_STREAM_CONFIG_IDLE:
190             switch (connection->signaling_packet.signal_identifier){
191                 case AVDTP_SI_GET_ALL_CAPABILITIES:
192                     log_info("    ACP: AVDTP_SI_GET_ALL_CAPABILITIES");
193                     stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_ANSWER_GET_ALL_CAPABILITIES;
194                     break;
195                 case AVDTP_SI_GET_CAPABILITIES:
196                     log_info("    ACP: AVDTP_ACCEPTOR_W2_ANSWER_GET_CAPABILITIES");
197                     stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_ANSWER_GET_CAPABILITIES;
198                     break;
199                 case AVDTP_SI_SET_CONFIGURATION:{
200                     log_info("    ACP: AVDTP_ACCEPTOR_W2_ANSWER_SET_CONFIGURATION ");
201                     stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_ANSWER_SET_CONFIGURATION;
202                     connection->reject_service_category = 0;
203                     stream_endpoint->connection = connection;
204                     avdtp_sep_t sep;
205                     sep.seid = connection->signaling_packet.command[offset++] >> 2;
206                     sep.configured_service_categories = avdtp_unpack_service_capabilities(connection, &sep.configuration, connection->signaling_packet.command+offset, packet_size-offset);
207                     sep.in_use = 1;
208 
209                     if (connection->error_code){
210                         log_info("fire configuration parsing errors ");
211                         connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
212                         stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE;
213                         break;
214                     }
215                     // find or add sep
216 
217                     stream_endpoint->remote_sep_index = avdtp_find_remote_sep(stream_endpoint->connection, sep.seid);
218                     log_info("    ACP .. seid %d, index %d", sep.seid, stream_endpoint->remote_sep_index);
219 
220                     if (stream_endpoint->remote_sep_index != AVDTP_INVALID_SEP_INDEX){
221                         if (stream_endpoint->connection->remote_seps[stream_endpoint->remote_sep_index].in_use){
222                             // reject if already configured
223                             connection->error_code = SEP_IN_USE;
224                             // find first registered category and fire the error
225                             connection->reject_service_category = 0;
226                             int i;
227                             for (i = 1; i < 9; i++){
228                                 if (get_bit16(sep.configured_service_categories, i)){
229                                     connection->reject_service_category = i;
230                                     break;
231                                 }
232                             }
233                             connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
234                             stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE;
235                         } else {
236                             stream_endpoint->connection->remote_seps[stream_endpoint->remote_sep_index] = sep;
237                             log_info("    ACP: update seid %d, to %p", stream_endpoint->connection->remote_seps[stream_endpoint->remote_sep_index].seid, stream_endpoint);
238                         }
239                     } else {
240                         // add new
241                         log_info("    ACP: seid %d not found in %p", sep.seid, stream_endpoint);
242                         stream_endpoint->remote_sep_index = connection->remote_seps_num;
243                         connection->remote_seps_num++;
244                         connection->remote_seps[stream_endpoint->remote_sep_index] = sep;
245                         log_info("    ACP: add seid %d, to %p", connection->remote_seps[stream_endpoint->remote_sep_index].seid, stream_endpoint);
246                     }
247                     if (get_bit16(sep.configured_service_categories, AVDTP_MEDIA_CODEC)){
248                         switch (sep.configuration.media_codec.media_codec_type){
249                             case AVDTP_CODEC_SBC:
250                                 avdtp_signaling_emit_media_codec_sbc_configuration(context->avdtp_callback, connection->con_handle, connection->int_seid, connection->acp_seid, sep.configuration.media_codec);
251                                 break;
252                             default:
253                                 avdtp_signaling_emit_media_codec_other_configuration(context->avdtp_callback, connection->con_handle, connection->int_seid, connection->acp_seid, sep.configuration.media_codec);
254                                 break;
255                         }
256                     }
257                     avdtp_signaling_emit_accept(context->avdtp_callback, connection->con_handle, connection->int_seid, connection->signaling_packet.signal_identifier, 0);
258                     break;
259                 }
260                 case AVDTP_SI_RECONFIGURE:{
261                     stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_ANSWER_RECONFIGURE;
262                     connection->reject_service_category = 0;
263 
264                     avdtp_sep_t sep;
265                     sep.seid = connection->query_seid;
266                     log_info("    ACP: AVDTP_ACCEPTOR_W2_ANSWER_RECONFIGURE seid %d", sep.seid);
267                     // log_info_hexdump(connection->signaling_packet.command, packet_size);
268 
269                     sep.configured_service_categories = avdtp_unpack_service_capabilities(connection, &sep.configuration, connection->signaling_packet.command+offset, packet_size-offset);
270 
271                     if (connection->error_code){
272                         // fire configuration parsing errors
273                         connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
274                         stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE;
275                         break;
276                     }
277 
278                     // find sep or raise error
279 
280                     stream_endpoint->remote_sep_index = avdtp_find_remote_sep(stream_endpoint->connection, sep.seid);
281                     if (stream_endpoint->remote_sep_index == AVDTP_INVALID_SEP_INDEX){
282                         log_info("    ACP: REJECT AVDTP_SI_RECONFIGURE, BAD_ACP_SEID");
283                         stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE;
284                         connection->error_code = BAD_ACP_SEID;
285                         connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
286                         break;
287                     }
288                     stream_endpoint->connection->remote_seps[stream_endpoint->remote_sep_index] = sep;
289                     log_info("    ACP: update seid %d, to %p", stream_endpoint->connection->remote_seps[stream_endpoint->remote_sep_index].seid, stream_endpoint);
290 
291                     if (get_bit16(sep.configured_service_categories, AVDTP_MEDIA_CODEC)){
292                         switch (sep.capabilities.media_codec.media_codec_type){
293                             case AVDTP_CODEC_SBC:
294                                 avdtp_signaling_emit_media_codec_sbc_reconfiguration(context->avdtp_callback, connection->con_handle, connection->int_seid, connection->acp_seid, sep.capabilities.media_codec);
295                                 break;
296                             default:
297                                 avdtp_signaling_emit_media_codec_other_reconfiguration(context->avdtp_callback, connection->con_handle, connection->int_seid, connection->acp_seid, sep.capabilities.media_codec);
298                                 break;
299                         }
300                     }
301                     avdtp_signaling_emit_accept(context->avdtp_callback, connection->con_handle, connection->int_seid, connection->signaling_packet.signal_identifier, 0);
302                     break;
303                 }
304 
305                 case AVDTP_SI_GET_CONFIGURATION:
306                     log_info("    ACP: AVDTP_ACCEPTOR_W2_ANSWER_GET_CONFIGURATION");
307                     stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_ANSWER_GET_CONFIGURATION;
308                     break;
309                 case AVDTP_SI_OPEN:
310                     if (stream_endpoint->state != AVDTP_STREAM_ENDPOINT_CONFIGURED){
311                         log_info("    ACP: REJECT AVDTP_SI_OPEN, BAD_STATE");
312                         stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_WITH_ERROR_CODE;
313                         connection->error_code = BAD_STATE;
314                         connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
315                         break;
316                     }
317                     log_info("    ACP: AVDTP_STREAM_ENDPOINT_W2_ANSWER_OPEN_STREAM");
318                     stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_ANSWER_OPEN_STREAM;
319                     stream_endpoint->state = AVDTP_STREAM_ENDPOINT_W4_L2CAP_FOR_MEDIA_CONNECTED;
320                     connection->query_seid = stream_endpoint->sep.seid;
321                     break;
322                 case AVDTP_SI_START:
323                     if (stream_endpoint->state != AVDTP_STREAM_ENDPOINT_OPENED){
324                         log_info("    ACP: REJECT AVDTP_SI_START, BAD_STATE");
325                         stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE;
326                         connection->error_code = BAD_STATE;
327                         connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
328                         break;
329                     }
330                     log_info("    ACP: AVDTP_ACCEPTOR_W2_ANSWER_START_STREAM");
331                     stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_ANSWER_START_STREAM;
332                     break;
333                 case AVDTP_SI_CLOSE:
334                     switch (stream_endpoint->state){
335                         case AVDTP_STREAM_ENDPOINT_OPENED:
336                         case AVDTP_STREAM_ENDPOINT_STREAMING:
337                             log_info("    ACP: AVDTP_ACCEPTOR_W2_ANSWER_CLOSE_STREAM");
338                             stream_endpoint->state = AVDTP_STREAM_ENDPOINT_CLOSING;
339                             stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_ANSWER_CLOSE_STREAM;
340                             break;
341                         default:
342                             log_info("    ACP: AVDTP_SI_CLOSE, bad state %d ", stream_endpoint->state);
343                             stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_WITH_ERROR_CODE;
344                             connection->error_code = BAD_STATE;
345                             connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
346                             break;
347                     }
348                     break;
349                 case AVDTP_SI_ABORT:
350                      switch (stream_endpoint->state){
351                         case AVDTP_STREAM_ENDPOINT_CONFIGURED:
352                         case AVDTP_STREAM_ENDPOINT_CLOSING:
353                         case AVDTP_STREAM_ENDPOINT_OPENED:
354                         case AVDTP_STREAM_ENDPOINT_STREAMING:
355                             log_info("    ACP: AVDTP_ACCEPTOR_W2_ANSWER_ABORT_STREAM");
356                             stream_endpoint->state = AVDTP_STREAM_ENDPOINT_ABORTING;
357                             stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_ANSWER_ABORT_STREAM;
358                             break;
359                         default:
360                             log_info("    ACP: AVDTP_SI_ABORT, bad state %d ", stream_endpoint->state);
361                             stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_WITH_ERROR_CODE;
362                             connection->error_code = BAD_STATE;
363                             connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
364                             break;
365                     }
366                     break;
367                 case AVDTP_SI_SUSPEND:
368                     log_info(" entering AVDTP_SI_SUSPEND");
369                     switch (stream_endpoint->state){
370                         case AVDTP_STREAM_ENDPOINT_OPENED:
371                         case AVDTP_STREAM_ENDPOINT_STREAMING:
372                             stream_endpoint->state = AVDTP_STREAM_ENDPOINT_OPENED;
373                             connection->num_suspended_seids--;
374                             if (connection->num_suspended_seids <= 0){
375                                 log_info("    ACP: AVDTP_ACCEPTOR_W2_ANSWER_SUSPEND_STREAM");
376                                 stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_ANSWER_SUSPEND_STREAM;
377                             }
378                             break;
379                         default:
380                             log_info("    ACP: AVDTP_SI_SUSPEND, bad state ");
381                             stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE;
382                             connection->error_code = BAD_STATE;
383                             connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
384                             break;
385                     }
386 
387                     //stream_endpoint->state = AVDTP_STREAM_ENDPOINT_SUSPENDING;
388                     //stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_SUSPEND_STREAM;
389                     break;
390                 default:
391                     log_info("    ACP: NOT IMPLEMENTED, Reject signal_identifier %02x", connection->signaling_packet.signal_identifier);
392                     stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_W2_REJECT_UNKNOWN_CMD;
393                     connection->reject_signal_identifier = connection->signaling_packet.signal_identifier;
394                     break;
395             }
396             break;
397         default:
398             return;
399     }
400 
401     if (!request_to_send){
402         log_info("    ACP: NOT IMPLEMENTED");
403     }
404     avdtp_request_can_send_now_acceptor(connection, connection->l2cap_signaling_cid);
405 }
406 
407 static int avdtp_acceptor_send_seps_response(uint16_t cid, uint8_t transaction_label, avdtp_stream_endpoint_t * endpoints){
408     uint8_t command[2+2*MAX_NUM_SEPS];
409     int pos = 0;
410     command[pos++] = avdtp_header(transaction_label, AVDTP_SINGLE_PACKET, AVDTP_RESPONSE_ACCEPT_MSG);
411     command[pos++] = (uint8_t)AVDTP_SI_DISCOVER;
412 
413     btstack_linked_list_iterator_t it;
414     btstack_linked_list_iterator_init(&it, (btstack_linked_list_t *) endpoints);
415     while (btstack_linked_list_iterator_has_next(&it)){
416         avdtp_stream_endpoint_t * stream_endpoint = (avdtp_stream_endpoint_t *)btstack_linked_list_iterator_next(&it);
417         command[pos++] = (stream_endpoint->sep.seid << 2) | (stream_endpoint->sep.in_use<<1);
418         command[pos++] = (stream_endpoint->sep.media_type << 4) | (stream_endpoint->sep.type << 3);
419     }
420     return l2cap_send(cid, command, pos);
421 }
422 
423 static int avdtp_acceptor_send_response_reject_service_category(uint16_t cid,  avdtp_signal_identifier_t identifier, uint8_t category, uint8_t error_code, uint8_t transaction_label){
424     uint8_t command[4];
425     command[0] = avdtp_header(transaction_label, AVDTP_SINGLE_PACKET, AVDTP_RESPONSE_REJECT_MSG);
426     command[1] = (uint8_t)identifier;
427     command[2] = category;
428     command[3] = error_code;
429     return l2cap_send(cid, command, sizeof(command));
430 }
431 
432 static int avdtp_acceptor_send_response_general_reject(uint16_t cid, avdtp_signal_identifier_t identifier, uint8_t transaction_label){
433     uint8_t command[2];
434     command[0] = avdtp_header(transaction_label, AVDTP_SINGLE_PACKET, AVDTP_GENERAL_REJECT_MSG);
435     command[1] = (uint8_t)identifier;
436     return l2cap_send(cid, command, sizeof(command));
437 }
438 
439 static int avdtp_acceptor_send_response_reject(uint16_t cid, avdtp_signal_identifier_t identifier, uint8_t transaction_label){
440     uint8_t command[2];
441     command[0] = avdtp_header(transaction_label, AVDTP_SINGLE_PACKET, AVDTP_RESPONSE_REJECT_MSG);
442     command[1] = (uint8_t)identifier;
443     return l2cap_send(cid, command, sizeof(command));
444 }
445 
446 static int avdtp_acceptor_send_response_reject_with_error_code(uint16_t cid, avdtp_signal_identifier_t identifier, uint8_t error_code, uint8_t transaction_label){
447     uint8_t command[3];
448     command[0] = avdtp_header(transaction_label, AVDTP_SINGLE_PACKET, AVDTP_RESPONSE_REJECT_MSG);
449     command[1] = (uint8_t)identifier;
450     command[2] = error_code;
451     return l2cap_send(cid, command, sizeof(command));
452 }
453 
454 void avdtp_acceptor_stream_config_subsm_run(avdtp_connection_t * connection, avdtp_context_t * context){
455     int sent = 1;
456     btstack_linked_list_t * stream_endpoints = &context->stream_endpoints;
457 
458     switch (connection->acceptor_connection_state){
459         case AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_ANSWER_DISCOVER_SEPS:
460             connection->state = AVDTP_SIGNALING_CONNECTION_OPENED;
461             connection->acceptor_connection_state = AVDTP_SIGNALING_CONNECTION_ACCEPTOR_IDLE;
462             avdtp_acceptor_send_seps_response(connection->l2cap_signaling_cid, connection->acceptor_transaction_label, (avdtp_stream_endpoint_t *) stream_endpoints);
463             break;
464         case AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_REJECT_WITH_ERROR_CODE:
465             connection->acceptor_connection_state = AVDTP_SIGNALING_CONNECTION_ACCEPTOR_IDLE;
466             avdtp_acceptor_send_response_reject_with_error_code(connection->l2cap_signaling_cid, connection->reject_signal_identifier, connection->error_code, connection->acceptor_transaction_label);
467             break;
468         case AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE:
469             connection->acceptor_connection_state = AVDTP_SIGNALING_CONNECTION_ACCEPTOR_IDLE;
470             avdtp_acceptor_send_response_reject_service_category(connection->l2cap_signaling_cid, connection->reject_signal_identifier, connection->reject_service_category, connection->error_code, connection->acceptor_transaction_label);
471             break;
472         case AVDTP_SIGNALING_CONNECTION_ACCEPTOR_W2_GENERAL_REJECT_WITH_ERROR_CODE:
473             connection->acceptor_connection_state = AVDTP_SIGNALING_CONNECTION_ACCEPTOR_IDLE;
474             avdtp_acceptor_send_response_general_reject(connection->l2cap_signaling_cid, connection->reject_signal_identifier, connection->acceptor_transaction_label);
475         default:
476             sent = 0;
477             break;
478     }
479     if (sent){
480         log_info("    ACP: DONE");
481         return;
482     }
483 
484     avdtp_stream_endpoint_t * stream_endpoint = avdtp_stream_endpoint_for_seid(connection->query_seid, context);
485     if (!stream_endpoint) return;
486 
487     uint8_t reject_service_category = connection->reject_service_category;
488     avdtp_signal_identifier_t reject_signal_identifier = connection->reject_signal_identifier;
489     uint8_t error_code = connection->error_code;
490     uint16_t cid = stream_endpoint->connection ? stream_endpoint->connection->l2cap_signaling_cid : connection->l2cap_signaling_cid;
491     uint8_t trid = stream_endpoint->connection ? stream_endpoint->connection->acceptor_transaction_label : connection->acceptor_transaction_label;
492 
493     avdtp_acceptor_stream_endpoint_state_t acceptor_config_state = stream_endpoint->acceptor_config_state;
494     stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_STREAM_CONFIG_IDLE;
495     uint8_t * out_buffer;
496     uint16_t pos;
497 
498     int status = 0;
499     switch (acceptor_config_state){
500         case AVDTP_ACCEPTOR_STREAM_CONFIG_IDLE:
501             break;
502         case AVDTP_ACCEPTOR_W2_ANSWER_GET_CAPABILITIES:
503             avdtp_prepare_capabilities(&connection->signaling_packet, trid, stream_endpoint->sep.registered_service_categories, stream_endpoint->sep.capabilities, AVDTP_SI_GET_CAPABILITIES);
504             l2cap_reserve_packet_buffer();
505             out_buffer = l2cap_get_outgoing_buffer();
506             pos = avdtp_signaling_create_fragment(cid, &connection->signaling_packet, out_buffer);
507             if (connection->signaling_packet.packet_type != AVDTP_SINGLE_PACKET && connection->signaling_packet.packet_type != AVDTP_END_PACKET){
508                 stream_endpoint->acceptor_config_state = acceptor_config_state;
509                 log_info("    ACP: fragmented");
510             } else {
511                 log_info("    ACP:DONE");
512             }
513             l2cap_send_prepared(cid, pos);
514             break;
515         case AVDTP_ACCEPTOR_W2_ANSWER_GET_ALL_CAPABILITIES:
516             avdtp_prepare_capabilities(&connection->signaling_packet, trid, stream_endpoint->sep.registered_service_categories, stream_endpoint->sep.capabilities, AVDTP_SI_GET_ALL_CAPABILITIES);
517             l2cap_reserve_packet_buffer();
518             out_buffer = l2cap_get_outgoing_buffer();
519             pos = avdtp_signaling_create_fragment(cid, &connection->signaling_packet, out_buffer);
520             if (connection->signaling_packet.packet_type != AVDTP_SINGLE_PACKET && connection->signaling_packet.packet_type != AVDTP_END_PACKET){
521                 stream_endpoint->acceptor_config_state = acceptor_config_state;
522                 log_info("    ACP: fragmented");
523             } else {
524                 log_info("    ACP:DONE");
525             }
526             l2cap_send_prepared(cid, pos);
527             break;
528         case AVDTP_ACCEPTOR_W2_ANSWER_SET_CONFIGURATION:
529             log_info("    ACP: DONE");
530             log_info("    -> AVDTP_STREAM_ENDPOINT_CONFIGURED");
531             stream_endpoint->connection = connection;
532             stream_endpoint->state = AVDTP_STREAM_ENDPOINT_CONFIGURED;
533             // TODO: consider reconfiguration
534             avdtp_acceptor_send_accept_response(cid, trid, AVDTP_SI_SET_CONFIGURATION);
535             break;
536         case AVDTP_ACCEPTOR_W2_ANSWER_RECONFIGURE:
537             log_info("    ACP: DONE ");
538             avdtp_acceptor_send_accept_response(cid, trid, AVDTP_SI_RECONFIGURE);
539             break;
540 
541         case AVDTP_ACCEPTOR_W2_ANSWER_GET_CONFIGURATION:{
542             avdtp_sep_t sep = stream_endpoint->connection->remote_seps[stream_endpoint->remote_sep_index];
543             avdtp_prepare_capabilities(&connection->signaling_packet, trid, sep.configured_service_categories, sep.configuration, AVDTP_SI_GET_CONFIGURATION);
544             l2cap_reserve_packet_buffer();
545             out_buffer = l2cap_get_outgoing_buffer();
546             pos = avdtp_signaling_create_fragment(cid, &connection->signaling_packet, out_buffer);
547             if (connection->signaling_packet.packet_type != AVDTP_SINGLE_PACKET && connection->signaling_packet.packet_type != AVDTP_END_PACKET){
548                 stream_endpoint->acceptor_config_state = acceptor_config_state;
549                 log_info("    ACP: fragmented");
550             } else {
551                 log_info("    ACP:DONE");
552             }
553             l2cap_send_prepared(cid, pos);
554             break;
555         }
556         case AVDTP_ACCEPTOR_W2_ANSWER_OPEN_STREAM:
557             log_info("    ACP: DONE");
558             avdtp_acceptor_send_accept_response(cid, trid, AVDTP_SI_OPEN);
559             break;
560         case AVDTP_ACCEPTOR_W2_ANSWER_START_STREAM:
561             log_info("    ACP: DONE ");
562             log_info("    -> AVDTP_STREAM_ENDPOINT_STREAMING ");
563             stream_endpoint->state = AVDTP_STREAM_ENDPOINT_STREAMING;
564             avdtp_acceptor_send_accept_response(cid, trid, AVDTP_SI_START);
565             break;
566         case AVDTP_ACCEPTOR_W2_ANSWER_CLOSE_STREAM:
567             log_info("    ACP: DONE");
568             avdtp_acceptor_send_accept_response(cid, trid, AVDTP_SI_CLOSE);
569             break;
570         case AVDTP_ACCEPTOR_W2_ANSWER_ABORT_STREAM:
571             log_info("    ACP: DONE");
572             avdtp_acceptor_send_accept_response(cid, trid, AVDTP_SI_ABORT);
573             break;
574         case AVDTP_ACCEPTOR_W2_ANSWER_SUSPEND_STREAM:
575             log_info("    ACP: DONE");
576             stream_endpoint->state = AVDTP_STREAM_ENDPOINT_OPENED;
577             avdtp_acceptor_send_accept_response(cid, trid, AVDTP_SI_SUSPEND);
578             break;
579         case AVDTP_ACCEPTOR_W2_REJECT_UNKNOWN_CMD:
580             status = 1;
581             log_info("    ACP: DONE REJECT");
582             connection->reject_signal_identifier = 0;
583             avdtp_acceptor_send_response_reject(cid, reject_signal_identifier, trid);
584             break;
585         case AVDTP_ACCEPTOR_W2_REJECT_CATEGORY_WITH_ERROR_CODE:
586             status = 1;
587             log_info("    ACP: DONE REJECT CATEGORY");
588             connection->reject_service_category = 0;
589             avdtp_acceptor_send_response_reject_service_category(cid, reject_signal_identifier, reject_service_category, error_code, trid);
590             break;
591 
592         case AVDTP_ACCEPTOR_W2_REJECT_WITH_ERROR_CODE:
593             status = 1;
594             log_info("    ACP: DONE REJECT");
595             connection->reject_signal_identifier = 0;
596             connection->error_code = 0;
597             avdtp_acceptor_send_response_reject_with_error_code(cid, reject_signal_identifier, error_code, trid);
598             break;
599         default:
600             status = 0;
601             log_info("    ACP: NOT IMPLEMENTED");
602             sent = 0;
603     }
604     avdtp_signaling_emit_accept(context->avdtp_callback, connection->con_handle, connection->int_seid, connection->signaling_packet.signal_identifier, status);
605 
606     // check fragmentation
607     if (connection->signaling_packet.packet_type != AVDTP_SINGLE_PACKET && connection->signaling_packet.packet_type != AVDTP_END_PACKET){
608         avdtp_request_can_send_now_acceptor(connection, connection->l2cap_signaling_cid);
609     }
610 }
611