xref: /btstack/src/classic/goep_client.c (revision 65e76442879710536c8282d7434f54986ceda717)
1 /*
2  * Copyright (C) 2014 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 BLUEKITCHEN
24  * GMBH 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__ "goep_client.c"
39 
40 #include "btstack_config.h"
41 
42 #include <stdint.h>
43 #include <string.h>
44 
45 #include "btstack_debug.h"
46 #include "hci_dump.h"
47 #include "bluetooth_sdp.h"
48 #include "btstack_event.h"
49 #include "classic/goep_client.h"
50 #include "classic/obex_message_builder.h"
51 #include "classic/obex.h"
52 #include "classic/obex_iterator.h"
53 #include "classic/rfcomm.h"
54 #include "classic/sdp_client.h"
55 #include "classic/sdp_util.h"
56 #include "l2cap.h"
57 
58 //------------------------------------------------------------------------------------------------------------
59 // goep_client.c
60 //
61 
62 #ifdef ENABLE_GOEP_L2CAP
63 #ifndef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE
64 #error "ENABLE_GOEP_L2CAP requires ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE. Please enable ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE or disable ENABLE_GOEP_L2CAP"
65 #endif
66 #endif
67 
68 static uint16_t goep_client_cid;
69 static btstack_linked_list_t goep_clients;
70 
71 static goep_client_t *    goep_client_sdp_active;
72 static uint8_t            goep_client_sdp_query_attribute_value[30];
73 static const unsigned int goep_client_sdp_query_attribute_value_buffer_size = sizeof(goep_client_sdp_query_attribute_value);
74 static uint8_t goep_packet_buffer[150];
75 
76 static inline void goep_client_emit_connected_event(goep_client_t * goep_client, uint8_t status){
77     uint8_t event[15];
78     int pos = 0;
79     event[pos++] = HCI_EVENT_GOEP_META;
80     pos++;  // skip len
81     event[pos++] = GOEP_SUBEVENT_CONNECTION_OPENED;
82     little_endian_store_16(event, pos, goep_client->cid);
83     pos+=2;
84     event[pos++] = status;
85     (void)memcpy(&event[pos], goep_client->bd_addr, 6);
86     pos += 6;
87     little_endian_store_16(event, pos, goep_client->con_handle);
88     pos += 2;
89     event[pos++] = goep_client->incoming;
90     event[1] = pos - 2;
91     if (pos != sizeof(event)) log_error("goep_client_emit_connected_event size %u", pos);
92     goep_client->client_handler(HCI_EVENT_PACKET, goep_client->cid, &event[0], pos);
93 }
94 
95 static inline void goep_client_emit_connection_closed_event(goep_client_t * goep_client){
96     uint8_t event[5];
97     int pos = 0;
98     event[pos++] = HCI_EVENT_GOEP_META;
99     pos++;  // skip len
100     event[pos++] = GOEP_SUBEVENT_CONNECTION_CLOSED;
101     little_endian_store_16(event, pos, goep_client->cid);
102     pos+=2;
103     event[1] = pos - 2;
104     if (pos != sizeof(event)) log_error("goep_client_emit_connection_closed_event size %u", pos);
105     goep_client->client_handler(HCI_EVENT_PACKET, goep_client->cid, &event[0], pos);
106 }
107 
108 static inline void goep_client_emit_can_send_now_event(goep_client_t * goep_client){
109     uint8_t event[5];
110     int pos = 0;
111     event[pos++] = HCI_EVENT_GOEP_META;
112     pos++;  // skip len
113     event[pos++] = GOEP_SUBEVENT_CAN_SEND_NOW;
114     little_endian_store_16(event, pos, goep_client->cid);
115     pos+=2;
116     event[1] = pos - 2;
117     if (pos != sizeof(event)) log_error("goep_client_emit_can_send_now_event size %u", pos);
118     goep_client->client_handler(HCI_EVENT_PACKET, goep_client->cid, &event[0], pos);
119 }
120 
121 static void goep_client_handle_connection_opened(goep_client_t * goep_client, uint8_t status, uint16_t mtu){
122     if (status) {
123         goep_client->state = GOEP_CLIENT_INIT;
124         btstack_linked_list_remove(&goep_clients, (btstack_linked_item_t *) goep_client);
125         log_info("goep_client: open failed, status %u", status);
126     } else {
127         goep_client->bearer_mtu = mtu;
128         goep_client->state = GOEP_CLIENT_CONNECTED;
129         log_info("goep_client: connection opened. cid %u, max frame size %u", goep_client->bearer_cid, goep_client->bearer_mtu);
130     }
131     goep_client_emit_connected_event(goep_client, status);
132 }
133 
134 static void goep_client_handle_connection_close(goep_client_t * goep_client){
135     goep_client->state = GOEP_CLIENT_INIT;
136     btstack_linked_list_remove(&goep_clients, (btstack_linked_item_t *) goep_client);
137     goep_client_emit_connection_closed_event(goep_client);
138 }
139 
140 static goep_client_t * goep_client_for_cid(uint16_t cid){
141     btstack_linked_list_iterator_t it;
142     btstack_linked_list_iterator_init(&it, &goep_clients);
143     while (btstack_linked_list_iterator_has_next(&it)){
144         goep_client_t * goep_client = (goep_client_t *) btstack_linked_list_iterator_next(&it);
145         if (goep_client->cid == cid){
146             return goep_client;
147         }
148     }
149     return NULL;
150 }
151 
152 static goep_client_t * goep_client_for_bearer_cid(uint16_t bearer_cid){
153     btstack_linked_list_iterator_t it;
154     btstack_linked_list_iterator_init(&it, &goep_clients);
155     while (btstack_linked_list_iterator_has_next(&it)){
156         goep_client_t * goep_client = (goep_client_t *) btstack_linked_list_iterator_next(&it);
157         if (goep_client->bearer_cid == bearer_cid){
158             return goep_client;
159         }
160     }
161     return NULL;
162 }
163 
164 static void goep_client_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
165     UNUSED(channel);
166     UNUSED(size);
167     goep_client_t * goep_client;
168     switch (packet_type){
169         case HCI_EVENT_PACKET:
170             switch (hci_event_packet_get_type(packet)) {
171 #ifdef ENABLE_GOEP_L2CAP
172                 case L2CAP_EVENT_CHANNEL_OPENED:
173                     goep_client = goep_client_for_bearer_cid(l2cap_event_channel_opened_get_local_cid(packet));
174                     btstack_assert(goep_client != NULL);
175                     goep_client_handle_connection_opened(goep_client, l2cap_event_channel_opened_get_status(packet),
176                                                          btstack_min(l2cap_event_channel_opened_get_remote_mtu(packet), l2cap_event_channel_opened_get_local_mtu(packet)));
177                     break;
178                 case L2CAP_EVENT_CAN_SEND_NOW:
179                     goep_client = goep_client_for_bearer_cid(l2cap_event_can_send_now_get_local_cid(packet));
180                     btstack_assert(goep_client != NULL);
181                     goep_client_emit_can_send_now_event(goep_client);
182                     break;
183                 case L2CAP_EVENT_CHANNEL_CLOSED:
184                     goep_client = goep_client_for_bearer_cid(l2cap_event_channel_closed_get_local_cid(packet));
185                     btstack_assert(goep_client != NULL);
186                     goep_client_handle_connection_close(goep_client);
187                     break;
188 #endif
189                 case RFCOMM_EVENT_CHANNEL_OPENED:
190                     goep_client = goep_client_for_bearer_cid(rfcomm_event_channel_opened_get_rfcomm_cid(packet));
191                     btstack_assert(goep_client != NULL);
192                     goep_client_handle_connection_opened(goep_client, rfcomm_event_channel_opened_get_status(packet), rfcomm_event_channel_opened_get_max_frame_size(packet));
193                     return;
194                 case RFCOMM_EVENT_CAN_SEND_NOW:
195                     goep_client = goep_client_for_bearer_cid(rfcomm_event_can_send_now_get_rfcomm_cid(packet));
196                     btstack_assert(goep_client != NULL);
197                     goep_client_emit_can_send_now_event(goep_client);
198                     break;
199                 case RFCOMM_EVENT_CHANNEL_CLOSED:
200                     goep_client = goep_client_for_bearer_cid(rfcomm_event_channel_closed_get_rfcomm_cid(packet));
201                     btstack_assert(goep_client != NULL);
202                     goep_client_handle_connection_close(goep_client);
203                     break;
204                 default:
205                     break;
206             }
207             break;
208         case L2CAP_DATA_PACKET:
209         case RFCOMM_DATA_PACKET:
210             goep_client = goep_client_for_bearer_cid(channel);
211             btstack_assert(goep_client != NULL);
212             goep_client->client_handler(GOEP_DATA_PACKET, goep_client->cid, packet, size);
213             break;
214         default:
215             break;
216     }
217 }
218 
219 static void goep_client_handle_sdp_query_end_of_record(goep_client_t * goep_client){
220     if (goep_client->uuid == BLUETOOTH_SERVICE_CLASS_MESSAGE_ACCESS_SERVER){
221         // use matching SDP record with highest MAP version as there might be additional records for backwards compatibility
222         if (goep_client->mas_info.instance_id == goep_client->map_mas_instance_id){
223             if (goep_client->mas_info.version > goep_client->map_version){
224                 // Requested MAS Instance found, accept info
225                 goep_client->rfcomm_port = goep_client->mas_info.rfcomm_port;
226                 goep_client->profile_supported_features = goep_client->mas_info.supported_features;
227                 goep_client->map_supported_message_types = goep_client->mas_info.supported_message_types;
228 #ifdef ENABLE_GOEP_L2CAP
229                 goep_client->l2cap_psm = goep_client->mas_info.l2cap_psm;
230                 goep_client->map_version = goep_client->mas_info.version;
231                 log_info("MAS Instance #%u found, version %u.%u: rfcomm #%u, l2cap 0x%04x ", goep_client->map_mas_instance_id,
232                          goep_client->map_version, goep_client->map_version, goep_client->rfcomm_port, goep_client->l2cap_psm);
233 #else
234                 log_info("MAS Instance #%u found, rfcomm #%u", goep_client->map_mas_instance_id,
235                      goep_client->rfcomm_port);
236 #endif
237             }
238         }
239     }
240 }
241 static uint8_t goep_client_start_connect(goep_client_t * goep_client){
242 #ifdef ENABLE_GOEP_L2CAP
243     if (goep_client->l2cap_psm && (goep_client->ertm_buffer != NULL)){
244         log_info("Remote GOEP L2CAP PSM: %u", goep_client->l2cap_psm);
245         return l2cap_ertm_create_channel(&goep_client_packet_handler, goep_client->bd_addr, goep_client->l2cap_psm,
246         &goep_client->ertm_config, goep_client->ertm_buffer,
247         goep_client->ertm_buffer_size, &goep_client->bearer_cid);
248     }
249 #endif
250     log_info("Remote GOEP RFCOMM Server Channel: %u", goep_client->rfcomm_port);
251     return rfcomm_create_channel(&goep_client_packet_handler, goep_client->bd_addr, goep_client->rfcomm_port, &goep_client->bearer_cid);
252 }
253 
254 static void goep_client_handle_sdp_query_event(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
255     goep_client_t * goep_client = goep_client_sdp_active;
256     btstack_assert(goep_client != NULL);
257 
258     UNUSED(packet_type);
259     UNUSED(channel);
260     UNUSED(size);
261 
262     des_iterator_t des_list_it;
263     des_iterator_t prot_it;
264     uint8_t status;
265     uint16_t record_index;
266     bool goep_server_found;
267 
268     switch (hci_event_packet_get_type(packet)){
269         case SDP_EVENT_QUERY_ATTRIBUTE_VALUE:
270 
271             // detect new record
272             record_index = sdp_event_query_attribute_byte_get_record_id(packet);
273             if (record_index != goep_client->record_index){
274                 goep_client->record_index = record_index;
275                 goep_client_handle_sdp_query_end_of_record(goep_client);
276                 memset(&goep_client->mas_info, 0, sizeof(goep_client->mas_info));
277             }
278 
279             // check if relevant attribute
280             switch(sdp_event_query_attribute_byte_get_attribute_id(packet)){
281                 case BLUETOOTH_ATTRIBUTE_PROTOCOL_DESCRIPTOR_LIST:
282                 case BLUETOOTH_ATTRIBUTE_PBAP_SUPPORTED_FEATURES:
283                 case BLUETOOTH_ATTRIBUTE_MAS_INSTANCE_ID:
284                 case BLUETOOTH_ATTRIBUTE_SUPPORTED_MESSAGE_TYPES:
285 #ifdef ENABLE_GOEP_L2CAP
286                 case BLUETOOTH_ATTRIBUTE_BLUETOOTH_PROFILE_DESCRIPTOR_LIST:
287                 case BLUETOOTH_ATTRIBUTE_GOEP_L2CAP_PSM:
288 #endif
289                     break;
290                 default:
291                     return;
292             }
293 
294             // warn if attribute too large to fit in our buffer
295             if (sdp_event_query_attribute_byte_get_attribute_length(packet) > goep_client_sdp_query_attribute_value_buffer_size) {
296                 log_error("SDP attribute value size exceeded for attribute %x: available %d, required %d", sdp_event_query_attribute_byte_get_attribute_id(packet), goep_client_sdp_query_attribute_value_buffer_size, sdp_event_query_attribute_byte_get_attribute_length(packet));
297                 break;
298             }
299 
300             // store single byte
301             goep_client_sdp_query_attribute_value[sdp_event_query_attribute_byte_get_data_offset(packet)] = sdp_event_query_attribute_byte_get_data(packet);
302 
303             // wait until value fully received
304             if ((uint16_t)(sdp_event_query_attribute_byte_get_data_offset(packet)+1) != sdp_event_query_attribute_byte_get_attribute_length(packet)) break;
305 
306             // process attributes
307             switch(sdp_event_query_attribute_byte_get_attribute_id(packet)) {
308                 case BLUETOOTH_ATTRIBUTE_PROTOCOL_DESCRIPTOR_LIST:
309                     for (des_iterator_init(&des_list_it, goep_client_sdp_query_attribute_value); des_iterator_has_more(&des_list_it); des_iterator_next(&des_list_it)) {
310                         uint8_t       *des_element;
311                         uint8_t       *element;
312                         uint32_t       uuid;
313 
314                         if (des_iterator_get_type(&des_list_it) != DE_DES) continue;
315 
316                         des_element = des_iterator_get_element(&des_list_it);
317                         des_iterator_init(&prot_it, des_element);
318 
319                         // first element is UUID
320                         element = des_iterator_get_element(&prot_it);
321                         if (de_get_element_type(element) != DE_UUID) continue;
322 
323                         uuid = de_get_uuid32(element);
324                         des_iterator_next(&prot_it);
325                         if (!des_iterator_has_more(&prot_it)) continue;
326 
327                         // second element is RFCOMM server channel or L2CAP PSM
328                         element = des_iterator_get_element(&prot_it);
329                         if (uuid == BLUETOOTH_PROTOCOL_RFCOMM){
330                             if (goep_client->uuid == BLUETOOTH_SERVICE_CLASS_MESSAGE_ACCESS_SERVER) {
331                                 goep_client->mas_info.rfcomm_port = element[de_get_header_size(element)];
332                             } else {
333                                 goep_client->rfcomm_port = element[de_get_header_size(element)];
334                             }
335                         }
336                     }
337                     break;
338 #ifdef ENABLE_GOEP_L2CAP
339 
340                 case BLUETOOTH_ATTRIBUTE_BLUETOOTH_PROFILE_DESCRIPTOR_LIST:
341                     for (des_iterator_init(&des_list_it, goep_client_sdp_query_attribute_value); des_iterator_has_more(&des_list_it); des_iterator_next(&des_list_it)) {
342                         uint8_t       *des_element;
343                         uint8_t       *element;
344                         uint32_t       uuid;
345 
346                         if (des_iterator_get_type(&des_list_it) != DE_DES) continue;
347 
348                         des_element = des_iterator_get_element(&des_list_it);
349                         des_iterator_init(&prot_it, des_element);
350                         element = des_iterator_get_element(&prot_it);
351 
352                         if (de_get_element_type(element) != DE_UUID) continue;
353 
354                         uuid = de_get_uuid32(element);
355                         des_iterator_next(&prot_it);
356                         switch (uuid){
357                             case BLUETOOTH_SERVICE_CLASS_MESSAGE_ACCESS_PROFILE:
358                                 if (!des_iterator_has_more(&prot_it)) continue;
359                                 de_element_get_uint16(des_iterator_get_element(&prot_it), &goep_client->mas_info.version);
360                                 break;
361                             default:
362                                 break;
363                         }
364                     }
365                     break;
366                 case BLUETOOTH_ATTRIBUTE_GOEP_L2CAP_PSM:
367                     if (goep_client->uuid == BLUETOOTH_SERVICE_CLASS_MESSAGE_ACCESS_SERVER){
368                         de_element_get_uint16(goep_client_sdp_query_attribute_value, &goep_client->mas_info.l2cap_psm);
369                     } else {
370                         de_element_get_uint16(goep_client_sdp_query_attribute_value, &goep_client->l2cap_psm);
371                     }
372                     break;
373 #endif
374                 // BLUETOOTH_ATTRIBUTE_PBAP_SUPPORTED_FEATURES == BLUETOOTH_ATTRIBUTE_MAP_SUPPORTED_FEATURES == 0x0317
375                 case BLUETOOTH_ATTRIBUTE_PBAP_SUPPORTED_FEATURES:
376                     if (de_get_element_type(goep_client_sdp_query_attribute_value) != DE_UINT) break;
377                     if (de_get_size_type(goep_client_sdp_query_attribute_value) != DE_SIZE_32) break;
378                     if (goep_client->uuid == BLUETOOTH_SERVICE_CLASS_MESSAGE_ACCESS_SERVER) {
379                         goep_client->mas_info.supported_features  = big_endian_read_32(goep_client_sdp_query_attribute_value, de_get_header_size(goep_client_sdp_query_attribute_value));
380                     } else {
381                         goep_client->profile_supported_features  = big_endian_read_32(goep_client_sdp_query_attribute_value, de_get_header_size(goep_client_sdp_query_attribute_value));
382                     }
383                     break;
384 
385                 case BLUETOOTH_ATTRIBUTE_MAS_INSTANCE_ID:
386                     if (de_get_element_type(goep_client_sdp_query_attribute_value) != DE_UINT) break;
387                     if (de_get_size_type(goep_client_sdp_query_attribute_value) != DE_SIZE_8) break;
388                     goep_client->mas_info.instance_id = goep_client_sdp_query_attribute_value[de_get_header_size(goep_client_sdp_query_attribute_value)];
389                     break;
390 
391                 case BLUETOOTH_ATTRIBUTE_SUPPORTED_MESSAGE_TYPES:
392                     if (de_get_element_type(goep_client_sdp_query_attribute_value) != DE_UINT) break;
393                     if (de_get_size_type(goep_client_sdp_query_attribute_value) != DE_SIZE_8) break;
394                     goep_client->mas_info.supported_message_types = goep_client_sdp_query_attribute_value[de_get_header_size(goep_client_sdp_query_attribute_value)];
395                     break;
396 
397                 default:
398                     break;
399             }
400             break;
401 
402         case SDP_EVENT_QUERY_COMPLETE:
403             goep_client_sdp_active = NULL;
404             goep_client_handle_sdp_query_end_of_record(goep_client);
405             status = sdp_event_query_complete_get_status(packet);
406             if (status != ERROR_CODE_SUCCESS){
407                 log_info("GOEP client, SDP query failed 0x%02x", status);
408                 goep_client_handle_connection_opened(goep_client, status, 0);
409                 break;
410             }
411             goep_server_found = false;
412             if (goep_client->rfcomm_port != 0){
413                 goep_server_found = true;
414             }
415 #ifdef ENABLE_GOEP_L2CAP
416             if (goep_client->l2cap_psm != 0){
417                 goep_server_found = true;
418             }
419 #endif
420             if (goep_server_found == false){
421                 log_info("No GOEP RFCOMM or L2CAP server found");
422                 goep_client_handle_connection_opened(goep_client, SDP_SERVICE_NOT_FOUND, 0);
423                 break;
424             }
425             (void) goep_client_start_connect(goep_client);
426             break;
427 
428         default:
429             break;
430     }
431 }
432 
433 static uint8_t * goep_client_get_outgoing_buffer(goep_client_t * goep_client){
434     if (goep_client->l2cap_psm){
435         return goep_packet_buffer;
436     } else {
437         return rfcomm_get_outgoing_buffer();
438     }
439 }
440 
441 static uint16_t goep_client_get_outgoing_buffer_len(goep_client_t * goep_client){
442     if (goep_client->l2cap_psm){
443         return sizeof(goep_packet_buffer);
444     } else {
445         return rfcomm_get_max_frame_size(goep_client->bearer_cid);
446     }
447 }
448 
449 static void goep_client_packet_init(goep_client_t *goep_client, uint8_t opcode) {
450     if (goep_client->l2cap_psm != 0){
451     } else {
452         rfcomm_reserve_packet_buffer();
453     }
454     // store opcode for parsing of response
455     goep_client->obex_opcode = opcode;
456 }
457 
458 void goep_client_init(void){
459 }
460 
461 void goep_client_deinit(void){
462     goep_clients = NULL;
463     goep_client_cid = 0;
464     memset(goep_client_sdp_query_attribute_value, 0, sizeof(goep_client_sdp_query_attribute_value));
465     memset(goep_packet_buffer, 0, sizeof(goep_packet_buffer));
466 }
467 
468 static void geop_client_sdp_query_start(void * context){
469     uint16_t goep_cid = (uint16_t)(uintptr_t) context;
470     goep_client_t * goep_client = goep_client_for_cid(goep_cid);
471     if (context != NULL){
472         goep_client_sdp_active = goep_client;
473         sdp_client_query_uuid16(&goep_client_handle_sdp_query_event, goep_client->bd_addr,
474                                 goep_client->uuid);
475     }
476 }
477 
478 uint8_t
479 goep_client_connect(goep_client_t *goep_client, l2cap_ertm_config_t *l2cap_ertm_config, uint8_t *l2cap_ertm_buffer,
480                     uint16_t l2cap_ertm_buffer_size, btstack_packet_handler_t handler, bd_addr_t addr, uint16_t uuid,
481                     uint8_t instance_id, uint16_t *out_cid) {
482     btstack_assert(goep_client != NULL);
483 
484     // get new goep cid, skip 0x0000
485     goep_client_cid++;
486     if (goep_client_cid == 0) {
487         goep_client_cid = 1;
488     }
489 
490     // add to list
491     memset(goep_client, 0, sizeof(goep_client_t));
492     goep_client->state = GOEP_CLIENT_W4_SDP;
493     goep_client->cid = goep_client_cid;
494     goep_client->client_handler = handler;
495     goep_client->uuid = uuid;
496     goep_client->map_mas_instance_id = instance_id;
497     goep_client->profile_supported_features = PROFILE_FEATURES_NOT_PRESENT;
498     (void)memcpy(goep_client->bd_addr, addr, 6);
499     goep_client->sdp_query_request.callback = geop_client_sdp_query_start;
500     goep_client->sdp_query_request.context = (void *)(uintptr_t) goep_client->cid;
501     goep_client->obex_connection_id = OBEX_CONNECTION_ID_INVALID;
502 #ifdef ENABLE_GOEP_L2CAP
503     if (l2cap_ertm_config != NULL){
504         memcpy(&goep_client->ertm_config, l2cap_ertm_config, sizeof(l2cap_ertm_config_t));
505     }
506     goep_client->ertm_buffer_size = l2cap_ertm_buffer_size;
507     goep_client->ertm_buffer = l2cap_ertm_buffer;
508 #else
509     UNUSED(l2cap_ertm_buffer);
510     UNUSED(l2cap_ertm_config);
511     UNUSED(l2cap_ertm_buffer_size);
512 #endif
513     btstack_linked_list_add(&goep_clients, (btstack_linked_item_t *) goep_client);
514 
515     // request sdp query
516     sdp_client_register_query_callback(&goep_client->sdp_query_request);
517 
518     *out_cid = goep_client->cid;
519     return ERROR_CODE_SUCCESS;
520 }
521 
522 #ifdef ENABLE_GOEP_L2CAP
523 uint8_t goep_client_connect_l2cap(goep_client_t *goep_client, l2cap_ertm_config_t *l2cap_ertm_config, uint8_t *l2cap_ertm_buffer,
524                           uint16_t l2cap_ertm_buffer_size, btstack_packet_handler_t handler, bd_addr_t addr, uint16_t l2cap_psm,
525                           uint16_t *out_cid){
526     btstack_assert(goep_client != NULL);
527     btstack_assert(l2cap_ertm_config != NULL);
528     btstack_assert(l2cap_ertm_buffer != NULL);
529 
530     // get new goep cid, skip 0x0000
531     goep_client_cid++;
532     if (goep_client_cid == 0) {
533         goep_client_cid = 1;
534     }
535 
536     // add to list
537     memset(goep_client, 0, sizeof(goep_client_t));
538     goep_client->state = GOEP_CLIENT_W4_SDP;
539     goep_client->cid = goep_client_cid;
540     goep_client->client_handler = handler;
541     goep_client->profile_supported_features = PROFILE_FEATURES_NOT_PRESENT;
542     (void)memcpy(goep_client->bd_addr, addr, 6);
543     goep_client->obex_connection_id = OBEX_CONNECTION_ID_INVALID;
544     memcpy(&goep_client->ertm_config, l2cap_ertm_config, sizeof(l2cap_ertm_config_t));
545     goep_client->ertm_buffer_size = l2cap_ertm_buffer_size;
546     goep_client->ertm_buffer = l2cap_ertm_buffer;
547     btstack_linked_list_add_tail(&goep_clients, (btstack_linked_item_t *) goep_client);
548 
549     goep_client->l2cap_psm = l2cap_psm;
550 
551     *out_cid = goep_client->cid;
552 
553     return goep_client_start_connect(goep_client);
554 }
555 #endif
556 
557 uint32_t goep_client_get_pbap_supported_features(uint16_t goep_cid){
558     goep_client_t * goep_client = goep_client_for_cid(goep_cid);
559     if (goep_client == NULL){
560         return PBAP_FEATURES_NOT_PRESENT;
561     }
562     return goep_client->profile_supported_features;
563 }
564 
565 uint32_t goep_client_get_map_supported_features(uint16_t goep_cid){
566     goep_client_t * goep_client = goep_client_for_cid(goep_cid);
567     if (goep_client == NULL){
568         return PROFILE_FEATURES_NOT_PRESENT;
569     }
570     return goep_client->profile_supported_features;
571 }
572 
573 uint8_t goep_client_get_map_mas_instance_id(uint16_t goep_cid){
574     goep_client_t * goep_client = goep_client_for_cid(goep_cid);
575     if (goep_client == NULL){
576         return 0;
577     }
578     return goep_client->map_mas_instance_id;
579 }
580 
581 uint8_t goep_client_get_map_supported_message_types(uint16_t goep_cid){
582     goep_client_t * goep_client = goep_client_for_cid(goep_cid);
583     if (goep_client == NULL){
584         return 0;
585     }
586     return goep_client->map_supported_message_types;
587 }
588 
589 
590 bool goep_client_version_20_or_higher(uint16_t goep_cid){
591     goep_client_t * goep_client = goep_client_for_cid(goep_cid);
592     if (goep_client == NULL){
593         return false;
594     }
595     return goep_client->l2cap_psm != 0;
596 }
597 
598 void goep_client_request_can_send_now(uint16_t goep_cid){
599     goep_client_t * goep_client = goep_client_for_cid(goep_cid);
600     if (goep_client == NULL){
601         return;
602     }
603     if (goep_client->l2cap_psm){
604         l2cap_request_can_send_now_event(goep_client->bearer_cid);
605     } else {
606         rfcomm_request_can_send_now_event(goep_client->bearer_cid);
607     }
608 }
609 
610 uint8_t goep_client_disconnect(uint16_t goep_cid){
611     goep_client_t * goep_client = goep_client_for_cid(goep_cid);
612     if (goep_client == NULL){
613         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
614     }
615     if (goep_client->l2cap_psm){
616         l2cap_disconnect(goep_client->bearer_cid);
617     } else {
618         rfcomm_disconnect(goep_client->bearer_cid);
619     }
620     return ERROR_CODE_SUCCESS;
621 }
622 
623 void goep_client_set_connection_id(uint16_t goep_cid, uint32_t connection_id){
624     goep_client_t * goep_client = goep_client_for_cid(goep_cid);
625     if (goep_client == NULL){
626         return;
627     }
628     goep_client->obex_connection_id = connection_id;
629 }
630 
631 uint8_t goep_client_get_request_opcode(uint16_t goep_cid){
632     goep_client_t * goep_client = goep_client_for_cid(goep_cid);
633     if (goep_client == NULL){
634         return 0;
635     }
636     return goep_client->obex_opcode;
637 }
638 
639 void goep_client_request_create_connect(uint16_t goep_cid, uint8_t obex_version_number, uint8_t flags, uint16_t maximum_obex_packet_length){
640     goep_client_t * goep_client = goep_client_for_cid(goep_cid);
641     if (goep_client == NULL){
642         return;
643     }
644     goep_client_packet_init(goep_client, OBEX_OPCODE_CONNECT);
645     // workaround: limit OBEX packet len to L2CAP/RFCOMM MTU to avoid handling of fragemented packets
646     maximum_obex_packet_length = btstack_min(maximum_obex_packet_length, goep_client->bearer_mtu);
647 
648     uint8_t * buffer = goep_client_get_outgoing_buffer(goep_client);
649     uint16_t buffer_len = goep_client_get_outgoing_buffer_len(goep_client);
650     obex_message_builder_request_create_connect(buffer, buffer_len, obex_version_number, flags, maximum_obex_packet_length);
651 }
652 
653 void goep_client_request_create_get(uint16_t goep_cid){
654     goep_client_t * goep_client = goep_client_for_cid(goep_cid);
655     if (goep_client == NULL){
656         return;
657     }
658     goep_client_packet_init(goep_client, OBEX_OPCODE_GET | OBEX_OPCODE_FINAL_BIT_MASK);
659     uint8_t * buffer = goep_client_get_outgoing_buffer(goep_client);
660     uint16_t buffer_len = goep_client_get_outgoing_buffer_len(goep_client);
661     obex_message_builder_request_create_get(buffer, buffer_len, goep_client->obex_connection_id);
662 }
663 
664 void goep_client_request_create_put(uint16_t goep_cid){
665     goep_client_t * goep_client = goep_client_for_cid(goep_cid);
666     if (goep_client == NULL){
667         return;
668     }
669     goep_client_packet_init(goep_client, OBEX_OPCODE_PUT | OBEX_OPCODE_FINAL_BIT_MASK);
670     uint8_t * buffer = goep_client_get_outgoing_buffer(goep_client);
671     uint16_t buffer_len = goep_client_get_outgoing_buffer_len(goep_client);
672     obex_message_builder_request_create_put(buffer, buffer_len, goep_client->obex_connection_id);
673 }
674 
675 void goep_client_request_create_set_path(uint16_t goep_cid, uint8_t flags){
676     goep_client_t * goep_client = goep_client_for_cid(goep_cid);
677     if (goep_client == NULL){
678         return;
679     }
680     goep_client_packet_init(goep_client, OBEX_OPCODE_SETPATH);
681     uint8_t * buffer = goep_client_get_outgoing_buffer(goep_client);
682     uint16_t buffer_len = goep_client_get_outgoing_buffer_len(goep_client);
683     obex_message_builder_request_create_set_path(buffer, buffer_len, flags, goep_client->obex_connection_id);
684 }
685 
686 void goep_client_request_create_abort(uint16_t goep_cid){
687     goep_client_t * goep_client = goep_client_for_cid(goep_cid);
688     if (goep_client == NULL){
689         return;
690     }
691     goep_client_packet_init(goep_client, OBEX_OPCODE_ABORT);
692 
693     uint8_t * buffer = goep_client_get_outgoing_buffer(goep_client);
694     uint16_t buffer_len = goep_client_get_outgoing_buffer_len(goep_client);
695     obex_message_builder_request_create_abort(buffer, buffer_len, goep_client->obex_connection_id);
696 }
697 
698 void goep_client_request_create_disconnect(uint16_t goep_cid){
699     goep_client_t * goep_client = goep_client_for_cid(goep_cid);
700     if (goep_client == NULL){
701         return;
702     }
703     goep_client_packet_init(goep_client, OBEX_OPCODE_DISCONNECT);
704     uint8_t * buffer = goep_client_get_outgoing_buffer(goep_client);
705     uint16_t buffer_len = goep_client_get_outgoing_buffer_len(goep_client);
706     obex_message_builder_request_create_disconnect(buffer, buffer_len, goep_client->obex_connection_id);
707 }
708 
709 void goep_client_header_add_byte(uint16_t goep_cid, uint8_t header_type, uint8_t value){
710     goep_client_t * goep_client = goep_client_for_cid(goep_cid);
711     if (goep_client == NULL){
712         return;
713     }
714     uint8_t * buffer = goep_client_get_outgoing_buffer(goep_client);
715     uint16_t buffer_len = goep_client_get_outgoing_buffer_len(goep_client);
716     obex_message_builder_header_add_byte(buffer, buffer_len, header_type, value);
717 }
718 
719 void goep_client_header_add_word(uint16_t goep_cid, uint8_t header_type, uint32_t value){
720     goep_client_t * goep_client = goep_client_for_cid(goep_cid);
721     if (goep_client == NULL){
722         return;
723     }
724     uint8_t * buffer = goep_client_get_outgoing_buffer(goep_client);
725     uint16_t buffer_len = goep_client_get_outgoing_buffer_len(goep_client);
726     obex_message_builder_header_add_word(buffer, buffer_len, header_type, value);
727 }
728 
729 void goep_client_header_add_variable(uint16_t goep_cid, uint8_t header_type, const uint8_t * header_data, uint16_t header_data_length){
730     goep_client_t * goep_client = goep_client_for_cid(goep_cid);
731     if (goep_client == NULL){
732         return;
733     }
734     uint8_t * buffer = goep_client_get_outgoing_buffer(goep_client);
735     uint16_t buffer_len = goep_client_get_outgoing_buffer_len(goep_client);
736     obex_message_builder_header_add_variable(buffer, buffer_len, header_type, header_data, header_data_length);
737 }
738 
739 void goep_client_header_add_srm_enable(uint16_t goep_cid){
740     goep_client_t * goep_client = goep_client_for_cid(goep_cid);
741     if (goep_client == NULL){
742         return;
743     }
744     uint8_t * buffer = goep_client_get_outgoing_buffer(goep_client);
745     uint16_t buffer_len = goep_client_get_outgoing_buffer_len(goep_client);
746     obex_message_builder_header_add_srm_enable(buffer, buffer_len);
747 }
748 
749 void goep_client_header_add_target(uint16_t goep_cid, const uint8_t * target, uint16_t length){
750     goep_client_t * goep_client = goep_client_for_cid(goep_cid);
751     if (goep_client == NULL){
752         return;
753     }
754     uint8_t * buffer = goep_client_get_outgoing_buffer(goep_client);
755     uint16_t buffer_len = goep_client_get_outgoing_buffer_len(goep_client);
756     obex_message_builder_header_add_target(buffer, buffer_len, target, length);
757 }
758 
759 void goep_client_header_add_application_parameters(uint16_t goep_cid, const uint8_t * data, uint16_t length){
760     goep_client_t * goep_client = goep_client_for_cid(goep_cid);
761     if (goep_client == NULL){
762         return;
763     }
764     uint8_t * buffer = goep_client_get_outgoing_buffer(goep_client);
765     uint16_t buffer_len = goep_client_get_outgoing_buffer_len(goep_client);
766     obex_message_builder_header_add_application_parameters(buffer, buffer_len, data, length);
767 }
768 
769 void goep_client_header_add_challenge_response(uint16_t goep_cid, const uint8_t * data, uint16_t length){
770     goep_client_t * goep_client = goep_client_for_cid(goep_cid);
771     if (goep_client == NULL){
772         return;
773     }
774     uint8_t * buffer = goep_client_get_outgoing_buffer(goep_client);
775     uint16_t buffer_len = goep_client_get_outgoing_buffer_len(goep_client);
776     obex_message_builder_header_add_challenge_response(buffer, buffer_len, data, length);
777 }
778 
779 void goep_client_body_add_static(uint16_t goep_cid, const uint8_t * data, uint32_t length){
780     goep_client_t * goep_client = goep_client_for_cid(goep_cid);
781     if (goep_client == NULL){
782         return;
783     }
784     uint8_t * buffer = goep_client_get_outgoing_buffer(goep_client);
785     uint16_t buffer_len = goep_client_get_outgoing_buffer_len(goep_client);
786     obex_message_builder_body_add_static(buffer, buffer_len, data, length);
787 }
788 
789 uint16_t goep_client_body_get_outgoing_buffer_len(uint16_t goep_cid) {
790     goep_client_t * goep_client = goep_client_for_cid(goep_cid);
791     if (goep_client == NULL){
792         return 0;
793     }
794     return goep_client_get_outgoing_buffer_len(goep_client);
795 }
796 
797 void goep_client_body_fillup_static(uint16_t goep_cid, const uint8_t * data, uint32_t length, uint32_t * ret_length){
798     goep_client_t * goep_client = goep_client_for_cid(goep_cid);
799     if (goep_client == NULL){
800         return;
801     }
802     uint8_t * buffer = goep_client_get_outgoing_buffer(goep_client);
803     uint16_t buffer_len = goep_client_get_outgoing_buffer_len(goep_client);
804     obex_message_builder_body_fillup_static(buffer, buffer_len, data, length, ret_length);
805 }
806 
807 void goep_client_header_add_name(uint16_t goep_cid, const char * name){
808     goep_client_t * goep_client = goep_client_for_cid(goep_cid);
809     if (goep_client == NULL){
810         return;
811     }
812     uint8_t * buffer = goep_client_get_outgoing_buffer(goep_client);
813     uint16_t buffer_len = goep_client_get_outgoing_buffer_len(goep_client);
814     obex_message_builder_header_add_name(buffer, buffer_len, name);
815 }
816 
817 void goep_client_header_add_name_prefix(uint16_t goep_cid, const char * name, uint16_t name_len){
818     goep_client_t * goep_client = goep_client_for_cid(goep_cid);
819     if (goep_client == NULL){
820         return;
821     }
822     uint8_t * buffer = goep_client_get_outgoing_buffer(goep_client);
823     uint16_t buffer_len = goep_client_get_outgoing_buffer_len(goep_client);
824     obex_message_builder_header_add_name_prefix(buffer, buffer_len, name, name_len);
825 }
826 
827 void goep_client_header_add_unicode_prefix(uint16_t goep_cid, uint8_t header_id, const char * name, uint16_t name_len){
828     goep_client_t * goep_client = goep_client_for_cid(goep_cid);
829     if (goep_client == NULL){
830         return;
831     }
832     uint8_t * buffer = goep_client_get_outgoing_buffer(goep_client);
833     uint16_t buffer_len = goep_client_get_outgoing_buffer_len(goep_client);
834     obex_message_builder_header_add_unicode_prefix(buffer, buffer_len, header_id, name, name_len);
835 }
836 
837 void goep_client_header_add_type(uint16_t goep_cid, const char * type){
838     goep_client_t * goep_client = goep_client_for_cid(goep_cid);
839     if (goep_client == NULL){
840         return;
841     }
842     uint8_t * buffer = goep_client_get_outgoing_buffer(goep_client);
843     uint16_t buffer_len = goep_client_get_outgoing_buffer_len(goep_client);
844     obex_message_builder_header_add_type(buffer, buffer_len, type);
845 }
846 
847 void goep_client_header_add_length(uint16_t goep_cid, uint32_t length){
848     goep_client_t * goep_client = goep_client_for_cid(goep_cid);
849     if (goep_client == NULL){
850         return;
851     }
852     uint8_t * buffer = goep_client_get_outgoing_buffer(goep_client);
853     uint16_t buffer_len = goep_client_get_outgoing_buffer_len(goep_client);
854     obex_message_builder_header_add_length(buffer, buffer_len, length);
855 }
856 
857 uint16_t goep_client_request_get_max_body_size(uint16_t goep_cid){
858     goep_client_t * goep_client = goep_client_for_cid(goep_cid);
859     if (goep_client == NULL){
860         return 0;
861     }
862     uint8_t * buffer = goep_client_get_outgoing_buffer(goep_client);
863     uint16_t buffer_len = goep_client_get_outgoing_buffer_len(goep_client);
864     uint16_t pos = big_endian_read_16(buffer, 1);
865     return buffer_len - pos;
866 }
867 
868 int goep_client_execute(uint16_t goep_cid){
869     goep_client_t * goep_client = goep_client_for_cid(goep_cid);
870     if (goep_client == NULL){
871         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
872     }
873     return goep_client_execute_with_final_bit (goep_cid, true);
874 }
875 
876 int goep_client_execute_with_final_bit(uint16_t goep_cid, bool final){
877     goep_client_t * goep_client = goep_client_for_cid(goep_cid);
878     if (goep_client == NULL){
879         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
880     }
881     uint8_t * buffer = goep_client_get_outgoing_buffer(goep_client);
882     uint16_t buffer_len = goep_client_get_outgoing_buffer_len(goep_client);
883 
884     obex_message_builder_set_final_bit (buffer, buffer_len, final);
885 
886     uint16_t pos = big_endian_read_16(buffer, 1);
887     if (goep_client->l2cap_psm){
888         return l2cap_send(goep_client->bearer_cid, buffer, pos);
889     } else {
890         return rfcomm_send_prepared(goep_client->bearer_cid, pos);
891     }
892 }
893 
894