xref: /btstack/src/classic/avrcp_cover_art_client.c (revision db806f4fd8e8d1df92cc0c13d105eac7ed7a8d1e)
1 /*
2  * Copyright (C) 2023 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__ "avrcp_cover_art_client.c"
39 
40 #include <string.h>
41 
42 #include "btstack_debug.h"
43 #include "btstack_event.h"
44 #include "classic/avrcp.h"
45 #include "classic/avrcp_cover_art_client.h"
46 #include "classic/obex.h"
47 #include "hci_event.h"
48 
49 #ifdef ENABLE_AVRCP_COVER_ART
50 
51 static const hci_event_t avrcp_cover_art_client_connected = {
52     .event_code = HCI_EVENT_AVRCP_META,
53     .subevent_code = AVRCP_SUBEVENT_COVER_ART_CONNECTION_ESTABLISHED,
54     .format = "1B22"
55 };
56 
57 static const hci_event_t avrcp_cover_art_client_disconnected = {
58     .event_code = HCI_EVENT_AVRCP_META,
59     .subevent_code = AVRCP_SUBEVENT_COVER_ART_CONNECTION_RELEASED,
60     .format = "2"
61 };
62 
63 static const hci_event_t avrcp_cover_art_client_operation_complete = {
64         .event_code = HCI_EVENT_AVRCP_META,
65         .subevent_code = AVRCP_SUBEVENT_COVER_ART_OPERATION_COMPLETE,
66         .format = "21"
67 };
68 
69 // 7163DD54-4A7E-11E2-B47C-0050C2490048
70 static const uint8_t avrcp_cover_art_uuid[] = { 0x71, 0x63, 0xDD, 0x54, 0x4A, 0x7E, 0x11, 0xE2, 0xB4, 0x7C, 0x00, 0x50, 0xC2, 0x49, 0x00, 0x48 };
71 
72 // OBEX types
73 const char * avrcp_cover_art_image_properties_type     = "x-bt/img-properties";
74 const char * avrcp_cover_art_image_type               = "x-bt/img-img";
75 const char * avrcp_cover_art_linked_thumbnail_type     = "x-bt/img-thm";
76 
77 static btstack_linked_list_t avrcp_cover_art_client_connections;
78 
79 static uint16_t avrcp_cover_art_client_next_cid(void) {
80     static uint16_t cid = 0;
81     cid++;
82     if (cid == 0){
83         cid = 1;
84     }
85     return cid;
86 }
87 
88 static avrcp_cover_art_client_t * avrcp_cover_art_client_for_goep_cid(uint16_t goep_cid){
89     btstack_linked_list_iterator_t it;
90     btstack_linked_list_iterator_init(&it, (btstack_linked_list_t *) &avrcp_cover_art_client_connections);
91     while (btstack_linked_list_iterator_has_next(&it)){
92         avrcp_cover_art_client_t * connection = (avrcp_cover_art_client_t *)btstack_linked_list_iterator_next(&it);
93         if (connection->goep_cid == goep_cid) {
94             return connection;
95         };
96     }
97     return NULL;
98 }
99 
100 static avrcp_cover_art_client_t * avrcp_cover_art_client_for_avrcp_cid(uint16_t avrcp_cid){
101     btstack_linked_list_iterator_t it;
102     btstack_linked_list_iterator_init(&it, (btstack_linked_list_t *) &avrcp_cover_art_client_connections);
103     while (btstack_linked_list_iterator_has_next(&it)){
104         avrcp_cover_art_client_t * connection = (avrcp_cover_art_client_t *)btstack_linked_list_iterator_next(&it);
105         if (connection->avrcp_cid == avrcp_cid) {
106             return connection;
107         };
108     }
109     return NULL;
110 }
111 
112 static avrcp_cover_art_client_t * avrcp_cover_art_client_for_cover_art_cid(uint16_t cover_art_cid){
113     btstack_linked_list_iterator_t it;
114     btstack_linked_list_iterator_init(&it, (btstack_linked_list_t *) &avrcp_cover_art_client_connections);
115     while (btstack_linked_list_iterator_has_next(&it)){
116         avrcp_cover_art_client_t * connection = (avrcp_cover_art_client_t *)btstack_linked_list_iterator_next(&it);
117         if (connection->cover_art_cid == cover_art_cid) {
118             return connection;
119         };
120     }
121     return NULL;
122 }
123 
124 static void avrcp_cover_art_client_emit_connection_established(btstack_packet_handler_t packet_handler, uint8_t status,
125                                                                bd_addr_t addr, uint16_t avrcp_cid,
126                                                                uint16_t cover_art_cid) {
127     uint8_t buffer[20];
128     uint16_t size = hci_event_create_from_template_and_arguments(buffer, sizeof(buffer), &avrcp_cover_art_client_connected, status, addr, avrcp_cid, cover_art_cid);
129     (*packet_handler)(HCI_EVENT_PACKET, 0, buffer, size);
130 }
131 
132 static void cover_art_client_emit_operation_complete_event(avrcp_cover_art_client_t * cover_art_client, uint8_t status) {
133     uint8_t buffer[20];
134     uint16_t size = hci_event_create_from_template_and_arguments(buffer, sizeof(buffer), &avrcp_cover_art_client_operation_complete, cover_art_client->cover_art_cid, status);
135     (*cover_art_client->packet_handler)(HCI_EVENT_PACKET, 0, buffer, size);
136 }
137 
138 static void avrcp_cover_art_client_emit_connection_released(btstack_packet_handler_t packet_handler, uint16_t cover_art_cid) {
139     uint8_t buffer[20];
140     uint16_t size = hci_event_create_from_template_and_arguments(buffer, sizeof(buffer), &avrcp_cover_art_client_disconnected, cover_art_cid);
141     (*packet_handler)(HCI_EVENT_PACKET, 0, buffer, size);
142 }
143 
144 static void avrcp_cover_art_finalize_connection(avrcp_cover_art_client_t *cover_art_client) {
145     btstack_assert(cover_art_client != NULL);
146     memset(cover_art_client, 0, sizeof(avrcp_cover_art_client_t));
147     btstack_linked_list_remove(&avrcp_cover_art_client_connections, (btstack_linked_item_t *) cover_art_client);
148 }
149 
150 static void avrcp_cover_art_client_parser_callback_connect(void * user_data, uint8_t header_id, uint16_t total_len, uint16_t data_offset, const uint8_t * data_buffer, uint16_t data_len){
151     avrcp_cover_art_client_t * client = (avrcp_cover_art_client_t *) user_data;
152     switch (header_id){
153         case OBEX_HEADER_CONNECTION_ID:
154             if (obex_parser_header_store(client->obex_header_buffer, sizeof(client->obex_header_buffer), total_len, data_offset, data_buffer, data_len) == OBEX_PARSER_HEADER_COMPLETE){
155                 goep_client_set_connection_id(client->goep_cid, big_endian_read_32(client->obex_header_buffer, 0));
156             }
157             break;
158         default:
159             break;
160     }
161 }
162 
163 static void avrcp_cover_art_client_prepare_srm_header(avrcp_cover_art_client_t * cover_art_client){
164     if (cover_art_client->flow_control_enabled == false){
165         obex_srm_client_prepare_header(&cover_art_client->obex_srm, cover_art_client->goep_cid);
166     }
167 }
168 
169 static void avrcp_cover_art_client_parser_callback_get_operation(void * user_data, uint8_t header_id, uint16_t total_len, uint16_t data_offset, const uint8_t * data_buffer, uint16_t data_len){
170     avrcp_cover_art_client_t *client = (avrcp_cover_art_client_t *) user_data;
171     switch (header_id) {
172         case OBEX_HEADER_SINGLE_RESPONSE_MODE:
173             obex_parser_header_store(&client->obex_srm.srm_value, 1, total_len, data_offset, data_buffer, data_len);
174             break;
175         case OBEX_HEADER_SINGLE_RESPONSE_MODE_PARAMETER:
176             obex_parser_header_store(&client->obex_srm.srmp_value, 1, total_len, data_offset, data_buffer, data_len);
177             break;
178         case OBEX_HEADER_BODY:
179         case OBEX_HEADER_END_OF_BODY:
180             switch(client->state){
181                 case AVRCP_COVER_ART_W4_OBJECT:
182                     client->packet_handler(BIP_DATA_PACKET, client->cover_art_cid, (uint8_t *) data_buffer, data_len);
183                     if (data_offset + data_len == total_len){
184                         client->flow_wait_for_user = true;
185                     }
186                     break;
187                 default:
188                     btstack_unreachable();
189                     break;
190             }
191             break;
192         default:
193             // ignore other headers
194             break;
195     }
196 }
197 
198 static void avrcp_cover_art_client_prepare_get_operation(avrcp_cover_art_client_t * cover_art_client){
199     obex_parser_init_for_response(&cover_art_client->obex_parser, OBEX_OPCODE_GET, avrcp_cover_art_client_parser_callback_get_operation, cover_art_client);
200     obex_srm_client_reset_fields(&cover_art_client->obex_srm);
201     cover_art_client->obex_parser_waiting_for_response = true;
202 }
203 
204 static void avrcp_cover_art_client_handle_can_send_now(avrcp_cover_art_client_t * cover_art_client){
205     switch (cover_art_client->state) {
206         case AVRCP_COVER_ART_W2_SEND_CONNECT_REQUEST:
207             // prepare request
208             goep_client_request_create_connect(cover_art_client->goep_cid, OBEX_VERSION, 0, OBEX_MAX_PACKETLEN_DEFAULT);
209             goep_client_header_add_target(cover_art_client->goep_cid, avrcp_cover_art_uuid, 16);
210             // state
211             cover_art_client->state = AVRCP_COVER_ART_W4_CONNECT_RESPONSE;
212             // prepare response
213             obex_parser_init_for_response(&cover_art_client->obex_parser, OBEX_OPCODE_CONNECT,
214                                           avrcp_cover_art_client_parser_callback_connect, cover_art_client);
215             obex_srm_client_init(&cover_art_client->obex_srm);
216             cover_art_client->obex_parser_waiting_for_response = true;
217             // send packet
218             goep_client_execute(cover_art_client->goep_cid);
219             break;
220         case AVRCP_COVER_ART_W2_SEND_GET_OBJECT:
221             goep_client_request_create_get(cover_art_client->goep_cid);
222             if (cover_art_client->first_request){
223                 cover_art_client->first_request = false;
224                 obex_srm_client_init(&cover_art_client->obex_srm);
225                 avrcp_cover_art_client_prepare_srm_header(cover_art_client);
226                 goep_client_header_add_type(cover_art_client->goep_cid, cover_art_client->object_type);
227                 if (cover_art_client->image_descriptor != NULL){
228                     goep_client_header_add_variable(cover_art_client->goep_cid, OBEX_HEADER_IMG_DESCRIPTOR, (const uint8_t *) cover_art_client->image_descriptor, (uint16_t) strlen(cover_art_client->image_descriptor));
229                 }
230                 uint8_t image_handle_len = btstack_max(7, (uint16_t) strlen(cover_art_client->image_handle));
231                 goep_client_header_add_unicode_prefix(cover_art_client->goep_cid, OBEX_HEADER_IMG_HANDLE, cover_art_client->image_handle, image_handle_len);
232             }
233             // state
234             cover_art_client->state = AVRCP_COVER_ART_W4_OBJECT;
235             cover_art_client->flow_next_triggered = 0;
236             cover_art_client->flow_wait_for_user = 0;
237             // prepare response
238             avrcp_cover_art_client_prepare_get_operation(cover_art_client);
239             // send packet
240             goep_client_execute(cover_art_client->goep_cid);
241             break;
242         case AVRCP_COVER_ART_W2_SEND_DISCONNECT_REQUEST:
243             // prepare request
244             goep_client_request_create_disconnect(cover_art_client->goep_cid);
245             // state
246             cover_art_client->state = AVRCP_COVER_ART_W4_DISCONNECT_RESPONSE;
247             // prepare response
248             obex_parser_init_for_response(&cover_art_client->obex_parser, OBEX_OPCODE_DISCONNECT, NULL, cover_art_client);
249             cover_art_client->obex_parser_waiting_for_response = true;
250             // send packet
251             goep_client_execute(cover_art_client->goep_cid);
252             return;
253         default:
254             break;
255     }
256 }
257 
258 static void avrcp_cover_art_goep_event_handler(const uint8_t *packet, uint16_t size) {
259     UNUSED(size);
260     uint8_t status;
261     avrcp_cover_art_client_t * cover_art_client;
262     btstack_packet_handler_t packet_handler;
263     uint16_t cover_art_cid;
264 
265     switch (hci_event_packet_get_type(packet)) {
266         case HCI_EVENT_GOEP_META:
267             switch (hci_event_goep_meta_get_subevent_code(packet)){
268                 case GOEP_SUBEVENT_CONNECTION_OPENED:
269                     cover_art_client = avrcp_cover_art_client_for_goep_cid(goep_subevent_connection_opened_get_goep_cid(packet));
270                     btstack_assert(cover_art_client != NULL);
271                     status = goep_subevent_connection_opened_get_status(packet);
272                     if (status){
273                         log_info("connection failed %u", status);
274                         avrcp_cover_art_finalize_connection(cover_art_client);
275                         avrcp_cover_art_client_emit_connection_established(cover_art_client->packet_handler, status,
276                                                                            cover_art_client->addr,
277                                                                            cover_art_client->avrcp_cid,
278                                                                            cover_art_client->cover_art_cid);
279                     } else {
280                         log_info("connection established");
281                         cover_art_client->state = AVRCP_COVER_ART_W2_SEND_CONNECT_REQUEST;
282                         goep_client_request_can_send_now(cover_art_client->goep_cid);
283                     }
284                     break;
285                 case GOEP_SUBEVENT_CONNECTION_CLOSED:
286                     cover_art_client = avrcp_cover_art_client_for_goep_cid(goep_subevent_connection_opened_get_goep_cid(packet));
287                     btstack_assert(cover_art_client != NULL);
288                     if (cover_art_client->state > AVRCP_COVER_ART_CONNECTED){
289                         cover_art_client_emit_operation_complete_event(cover_art_client, OBEX_DISCONNECTED);
290                     }
291                     cover_art_cid = cover_art_client->cover_art_cid;
292                     packet_handler = cover_art_client->packet_handler;
293                     avrcp_cover_art_finalize_connection(cover_art_client);
294                     avrcp_cover_art_client_emit_connection_released(packet_handler, cover_art_cid);
295                     break;
296                 case GOEP_SUBEVENT_CAN_SEND_NOW:
297                     cover_art_client = avrcp_cover_art_client_for_goep_cid(goep_subevent_can_send_now_get_goep_cid(packet));
298                     btstack_assert(cover_art_client != NULL);
299                     avrcp_cover_art_client_handle_can_send_now(cover_art_client);
300                     break;
301                 default:
302                     break;
303             }
304             break;
305         default:
306             break;
307     }
308 }
309 
310 static void avrcp_cover_art_client_goep_data_handler(avrcp_cover_art_client_t * cover_art_client, uint8_t *packet, uint16_t size){
311     btstack_assert(cover_art_client->obex_parser_waiting_for_response);
312 
313     obex_parser_object_state_t parser_state;
314     parser_state = obex_parser_process_data(&cover_art_client->obex_parser, packet, size);
315     if (parser_state == OBEX_PARSER_OBJECT_STATE_COMPLETE){
316         cover_art_client->obex_parser_waiting_for_response = false;
317         obex_parser_operation_info_t op_info;
318         obex_parser_get_operation_info(&cover_art_client->obex_parser, &op_info);
319         switch (cover_art_client->state){
320             case AVRCP_COVER_ART_W4_CONNECT_RESPONSE:
321                 switch (op_info.response_code) {
322                     case OBEX_RESP_SUCCESS:
323                         cover_art_client->state = AVRCP_COVER_ART_CONNECTED;
324                         avrcp_cover_art_client_emit_connection_established(cover_art_client->packet_handler,
325                                                                            ERROR_CODE_SUCCESS,
326                                                                            cover_art_client->addr,
327                                                                            cover_art_client->avrcp_cid,
328                                                                            cover_art_client->cover_art_cid);
329                         break;
330                     default:
331                         log_info("pbap: obex connect failed, result 0x%02x", packet[0]);
332                         cover_art_client->state = AVRCP_COVER_ART_INIT;
333                         avrcp_cover_art_client_emit_connection_established(cover_art_client->packet_handler,
334                                                                            OBEX_CONNECT_FAILED,
335                                                                            cover_art_client->addr,
336                                                                            cover_art_client->avrcp_cid,
337                                                                            cover_art_client->cover_art_cid);
338                         break;
339                 }
340                 break;
341             case AVRCP_COVER_ART_W4_OBJECT:
342                 switch (op_info.response_code) {
343                     case OBEX_RESP_CONTINUE:
344                         obex_srm_client_handle_headers(&cover_art_client->obex_srm);
345                         if (obex_srm_client_is_srm_active(&cover_art_client->obex_srm)) {
346                             // prepare response
347                             avrcp_cover_art_client_prepare_get_operation(cover_art_client);
348                             break;
349                         }
350                         cover_art_client->state = AVRCP_COVER_ART_W2_SEND_GET_OBJECT;
351                         if (!cover_art_client->flow_control_enabled || !cover_art_client->flow_wait_for_user ||
352                             cover_art_client->flow_next_triggered) {
353                             goep_client_request_can_send_now(cover_art_client->goep_cid);
354                         }
355                         break;
356                     case OBEX_RESP_SUCCESS:
357                         cover_art_client->state = AVRCP_COVER_ART_CONNECTED;
358                         cover_art_client_emit_operation_complete_event(cover_art_client, ERROR_CODE_SUCCESS);
359                         break;
360                     default:
361                         log_info("unexpected response 0x%02x", packet[0]);
362                         cover_art_client->state = AVRCP_COVER_ART_CONNECTED;
363                         cover_art_client_emit_operation_complete_event(cover_art_client, OBEX_UNKNOWN_ERROR);
364                         break;
365                 }
366                 break;
367             case AVRCP_COVER_ART_W4_DISCONNECT_RESPONSE:
368                 goep_client_disconnect(cover_art_client->goep_cid);
369                 break;
370             default:
371                 btstack_unreachable();
372                 break;
373         }
374     }
375 }
376 
377 static void avrcp_cover_art_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
378     UNUSED(channel); // ok: there is no channel
379     UNUSED(size);    // ok: handling own goep events
380     avrcp_cover_art_client_t * cover_art_client;
381     switch (packet_type){
382         case HCI_EVENT_PACKET:
383             avrcp_cover_art_goep_event_handler(packet, size);
384             break;
385         case GOEP_DATA_PACKET:
386             cover_art_client = avrcp_cover_art_client_for_goep_cid(channel);
387             btstack_assert(cover_art_client != NULL);
388             avrcp_cover_art_client_goep_data_handler(cover_art_client, packet, size);
389             break;
390         default:
391             break;
392     }
393 }
394 
395 static uint8_t avrcp_cover_art_client_setup_connection(avrcp_cover_art_client_t * cover_art_client, uint16_t l2cap_psm){
396     cover_art_client->state = AVRCP_COVER_ART_W4_GOEP_CONNECTION;
397     return goep_client_connect_l2cap(&cover_art_client->goep_client,
398                                      (l2cap_ertm_config_t *) cover_art_client->ertm_config,
399                                      cover_art_client->ertm_buffer,
400                                      cover_art_client->ertm_buffer_size,
401                                      &avrcp_cover_art_packet_handler,
402                                      cover_art_client->addr,
403                                      l2cap_psm,
404                                      &cover_art_client->goep_cid);
405 }
406 
407 static void avrcp_cover_art_handle_sdp_query_complete(avrcp_connection_t * connection, uint8_t status){
408     avrcp_cover_art_client_t * cover_art_client = avrcp_cover_art_client_for_avrcp_cid(connection->avrcp_cid);
409 
410     if (cover_art_client == NULL) {
411         return;
412     }
413     if (cover_art_client->state != AVRCP_COVER_ART_W4_SDP_QUERY_COMPLETE){
414         return;
415     }
416 
417     // l2cap available?
418     if (status == ERROR_CODE_SUCCESS){
419         if (connection->cover_art_psm == 0){
420             status = SDP_SERVICE_NOT_FOUND;
421         }
422     }
423 
424     if (status == ERROR_CODE_SUCCESS) {
425         // ready to connect
426         cover_art_client->state = AVRCP_COVER_ART_W2_GOEP_CONNECT;
427         status = avrcp_cover_art_client_setup_connection(cover_art_client, connection->cover_art_psm);
428     }
429 
430     if (status != ERROR_CODE_SUCCESS){
431         btstack_packet_handler_t packet_handler = cover_art_client->packet_handler;
432         uint16_t cover_art_cid = cover_art_client->cover_art_cid;
433         uint16_t avrcp_cid =  cover_art_client->avrcp_cid;
434         avrcp_cover_art_finalize_connection(cover_art_client);
435         avrcp_cover_art_client_emit_connection_established(packet_handler, status, connection->remote_addr,
436                                                            avrcp_cid, cover_art_cid);
437     }
438 }
439 
440 void avrcp_cover_art_client_init(void){
441     avrcp_register_cover_art_sdp_query_complete_handler(&avrcp_cover_art_handle_sdp_query_complete);
442 }
443 
444 uint8_t
445 avrcp_cover_art_client_connect(avrcp_cover_art_client_t *cover_art_client, btstack_packet_handler_t packet_handler,
446                                bd_addr_t remote_addr, uint8_t *ertm_buffer, uint32_t ertm_buffer_size,
447                                const l2cap_ertm_config_t *ertm_config, uint16_t *avrcp_cover_art_cid) {
448 
449     avrcp_connection_t * connection_controller = avrcp_get_connection_for_bd_addr_for_role(AVRCP_CONTROLLER, remote_addr);
450     avrcp_connection_t * connection_target = avrcp_get_connection_for_bd_addr_for_role(AVRCP_TARGET, remote_addr);
451     if ((connection_target == NULL) || (connection_controller == NULL)){
452         return ERROR_CODE_COMMAND_DISALLOWED;
453     }
454 
455     cover_art_client->cover_art_cid = avrcp_cover_art_client_next_cid();
456     memcpy(cover_art_client->addr, remote_addr, 6);
457     cover_art_client->avrcp_cid = connection_controller->avrcp_cid;
458     cover_art_client->packet_handler = packet_handler;
459     cover_art_client->flow_control_enabled = false;
460 
461     // store ERTM config
462     cover_art_client->ertm_config = ertm_config;
463     cover_art_client->ertm_buffer = ertm_buffer;
464     cover_art_client->ertm_buffer_size = ertm_buffer_size;
465 
466     if (avrcp_cover_art_cid != NULL){
467         *avrcp_cover_art_cid = cover_art_client->cover_art_cid;
468     }
469 
470     btstack_linked_list_add(&avrcp_cover_art_client_connections, (btstack_linked_item_t *) cover_art_client);
471 
472     if (connection_controller->cover_art_psm == 0){
473         cover_art_client->state = AVRCP_COVER_ART_W4_SDP_QUERY_COMPLETE;
474         avrcp_trigger_sdp_query(connection_controller, connection_controller);
475         return ERROR_CODE_SUCCESS;
476     } else {
477         return avrcp_cover_art_client_setup_connection(cover_art_client, connection_controller->cover_art_psm);
478     }
479 }
480 
481 static uint8_t avrcp_cover_art_client_get_object(uint16_t avrcp_cover_art_cid, const char * object_type, const char * image_handle, const char * image_descriptor){
482     avrcp_cover_art_client_t * cover_art_client = avrcp_cover_art_client_for_cover_art_cid(avrcp_cover_art_cid);
483     if (cover_art_client == NULL){
484         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
485     }
486     if (cover_art_client->state != AVRCP_COVER_ART_CONNECTED){
487         return ERROR_CODE_COMMAND_DISALLOWED;
488     }
489     cover_art_client->state = AVRCP_COVER_ART_W2_SEND_GET_OBJECT;
490     cover_art_client->first_request = true;
491     cover_art_client->image_handle = image_handle;
492     cover_art_client->image_descriptor = image_descriptor;
493     cover_art_client->object_type = object_type;
494     goep_client_request_can_send_now(cover_art_client->goep_cid);
495     return ERROR_CODE_SUCCESS;
496 }
497 
498 uint8_t avrcp_cover_art_client_get_linked_thumbnail(uint16_t avrcp_cover_art_cid, const char * image_handle){
499     return avrcp_cover_art_client_get_object(avrcp_cover_art_cid,
500                                              avrcp_cover_art_linked_thumbnail_type,
501                                              image_handle,
502                                              NULL);
503 }
504 
505 uint8_t avrcp_cover_art_client_get_image(uint16_t avrcp_cover_art_cid, const char * image_handle, const char * image_descriptor){
506     return avrcp_cover_art_client_get_object(avrcp_cover_art_cid,
507                                              avrcp_cover_art_image_type,
508                                              image_handle,
509                                              image_descriptor);
510 }
511 
512 uint8_t avrcp_cover_art_client_get_image_properties(uint16_t avrcp_cover_art_cid, const char * image_handle){
513     return avrcp_cover_art_client_get_object(avrcp_cover_art_cid,
514                                              avrcp_cover_art_image_properties_type,
515                                              image_handle,
516                                              NULL);
517 }
518 
519 uint8_t avrcp_cover_art_client_disconnect(uint16_t avrcp_cover_art_cid){
520     avrcp_cover_art_client_t * cover_art_client = avrcp_cover_art_client_for_cover_art_cid(avrcp_cover_art_cid);
521     if (cover_art_client == NULL){
522         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
523     }
524     if (cover_art_client->state < AVRCP_COVER_ART_CONNECTED){
525         return ERROR_CODE_COMMAND_DISALLOWED;
526     }
527     cover_art_client->state = AVRCP_COVER_ART_W2_SEND_DISCONNECT_REQUEST;
528     goep_client_request_can_send_now(cover_art_client->goep_cid);
529     return ERROR_CODE_SUCCESS;
530 }
531 
532 void avrcp_cover_art_client_deinit(void){
533     avrcp_cover_art_client_connections = NULL;
534 }
535 
536 #endif /* ENABLE_AVRCP_COVER_ART */
537