xref: /btstack/src/classic/sdp_client.c (revision 1a6822024624aab466a9aff5f67325f81ed6d5e2)
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 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 /*
39  *  sdp_client.c
40  */
41 
42 #include "btstack_config.h"
43 #include "btstack_debug.h"
44 #include "btstack_event.h"
45 #include "classic/core.h"
46 #include "classic/sdp_client.h"
47 #include "classic/sdp_server.h"
48 #include "classic/sdp_util.h"
49 #include "hci_cmd.h"
50 #include "l2cap.h"
51 
52 // Types SDP Parser - Data Element stream helper
53 typedef enum {
54     GET_LIST_LENGTH = 1,
55     GET_RECORD_LENGTH,
56     GET_ATTRIBUTE_ID_HEADER_LENGTH,
57     GET_ATTRIBUTE_ID,
58     GET_ATTRIBUTE_VALUE_LENGTH,
59     GET_ATTRIBUTE_VALUE
60 } sdp_parser_state_t;
61 
62 // Types SDP Client
63 typedef enum {
64     INIT, W4_CONNECT, W2_SEND, W4_RESPONSE, QUERY_COMPLETE
65 } sdp_client_state_t;
66 
67 
68 // Prototypes SDP Parser
69 void sdp_parser_init(btstack_packet_handler_t callback);
70 void sdp_parser_handle_chunk(uint8_t * data, uint16_t size);
71 void sdp_parser_handle_done(uint8_t status);
72 void sdp_parser_init_service_attribute_search(void);
73 void sdp_parser_init_service_search(void);
74 void sdp_parser_handle_service_search(uint8_t * data, uint16_t total_count, uint16_t record_handle_count);
75 
76 // Prototypes SDP Client
77 void sdp_client_reset(void);
78 void sdp_client_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
79 static uint16_t sdp_client_setup_service_search_attribute_request(uint8_t * data);
80 #ifdef ENABLE_SDP_EXTRA_QUERIES
81 static uint16_t sdp_client_setup_service_search_request(uint8_t * data);
82 static uint16_t sdp_client_setup_service_attribute_request(uint8_t * data);
83 static void     sdp_client_parse_service_search_response(uint8_t* packet);
84 static void     sdp_client_parse_service_attribute_response(uint8_t* packet);
85 #endif
86 
87 static uint8_t des_attributeIDList[] = { 0x35, 0x05, 0x0A, 0x00, 0x01, 0xff, 0xff};  // Attribute: 0x0001 - 0x0100
88 
89 // State DES Parser
90 static de_state_t de_header_state;
91 
92 // State SDP Parser
93 static sdp_parser_state_t  state = GET_LIST_LENGTH;
94 static uint16_t attribute_id = 0;
95 static uint16_t attribute_bytes_received = 0;
96 static uint16_t attribute_bytes_delivered = 0;
97 static uint16_t list_offset = 0;
98 static uint16_t list_size;
99 static uint16_t record_offset = 0;
100 static uint16_t record_size;
101 static uint16_t attribute_value_size;
102 static int record_counter = 0;
103 static btstack_packet_handler_t sdp_parser_callback;
104 
105 // State SDP Client
106 static uint16_t  mtu;
107 static uint16_t  sdp_cid = 0x40;
108 static const uint8_t * service_search_pattern;
109 static const uint8_t * attribute_id_list;
110 static uint16_t  transactionID = 0;
111 static uint8_t   continuationState[16];
112 static uint8_t   continuationStateLen;
113 static sdp_client_state_t sdp_client_state = INIT;
114 static SDP_PDU_ID_t PDU_ID = SDP_Invalid;
115 #ifdef ENABLE_SDP_EXTRA_QUERIES
116 static uint32_t serviceRecordHandle;
117 static uint32_t record_handle;
118 #endif
119 
120 // DES Parser
121 void de_state_init(de_state_t * de_state){
122     de_state->in_state_GET_DE_HEADER_LENGTH = 1;
123     de_state->addon_header_bytes = 0;
124     de_state->de_size = 0;
125     de_state->de_offset = 0;
126 }
127 
128 int de_state_size(uint8_t eventByte, de_state_t *de_state){
129     if (de_state->in_state_GET_DE_HEADER_LENGTH){
130         de_state->addon_header_bytes = de_get_header_size(&eventByte) - 1;
131         de_state->de_size = 0;
132         de_state->de_offset = 0;
133 
134         if (de_state->addon_header_bytes == 0){
135             de_state->de_size = de_get_data_size(&eventByte);
136             if (de_state->de_size == 0) {
137                 log_error("  ERROR: ID size is zero");
138             }
139             // log_info("Data element payload is %d bytes.", de_state->de_size);
140             return 1;
141         }
142         de_state->in_state_GET_DE_HEADER_LENGTH = 0;
143         return 0;
144     }
145 
146     if (de_state->addon_header_bytes > 0){
147         de_state->de_size = (de_state->de_size << 8) | eventByte;
148         de_state->addon_header_bytes--;
149     }
150     if (de_state->addon_header_bytes > 0) return 0;
151     // log_info("Data element payload is %d bytes.", de_state->de_size);
152     de_state->in_state_GET_DE_HEADER_LENGTH = 1;
153     return 1;
154 }
155 
156 // SDP Parser
157 static void sdp_parser_emit_value_byte(uint8_t event_byte){
158     uint8_t event[11];
159     event[0] = SDP_EVENT_QUERY_ATTRIBUTE_VALUE;
160     event[1] = 9;
161     little_endian_store_16(event, 2, record_counter);
162     little_endian_store_16(event, 4, attribute_id);
163     little_endian_store_16(event, 6, attribute_value_size);
164     little_endian_store_16(event, 8, attribute_bytes_delivered);
165     event[10] = event_byte;
166     (*sdp_parser_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
167 }
168 
169 static void sdp_parser_process_byte(uint8_t eventByte){
170     // count all bytes
171     list_offset++;
172     record_offset++;
173 
174     // log_info(" parse BYTE_RECEIVED %02x", eventByte);
175     switch(state){
176         case GET_LIST_LENGTH:
177             if (!de_state_size(eventByte, &de_header_state)) break;
178             list_offset = de_header_state.de_offset;
179             list_size = de_header_state.de_size;
180             // log_info("parser: List offset %u, list size %u", list_offset, list_size);
181 
182             record_counter = 0;
183             state = GET_RECORD_LENGTH;
184             break;
185 
186         case GET_RECORD_LENGTH:
187             // check size
188             if (!de_state_size(eventByte, &de_header_state)) break;
189             // log_info("parser: Record payload is %d bytes.", de_header_state.de_size);
190             record_offset = de_header_state.de_offset;
191             record_size = de_header_state.de_size;
192             state = GET_ATTRIBUTE_ID_HEADER_LENGTH;
193             break;
194 
195         case GET_ATTRIBUTE_ID_HEADER_LENGTH:
196             if (!de_state_size(eventByte, &de_header_state)) break;
197             attribute_id = 0;
198             log_info("ID data is stored in %d bytes.", (int) de_header_state.de_size);
199             state = GET_ATTRIBUTE_ID;
200             break;
201 
202         case GET_ATTRIBUTE_ID:
203             attribute_id = (attribute_id << 8) | eventByte;
204             de_header_state.de_size--;
205             if (de_header_state.de_size > 0) break;
206             log_info("parser: Attribute ID: %04x.", attribute_id);
207 
208             state = GET_ATTRIBUTE_VALUE_LENGTH;
209             attribute_bytes_received  = 0;
210             attribute_bytes_delivered = 0;
211             attribute_value_size      = 0;
212             de_state_init(&de_header_state);
213             break;
214 
215         case GET_ATTRIBUTE_VALUE_LENGTH:
216             attribute_bytes_received++;
217             sdp_parser_emit_value_byte(eventByte);
218             attribute_bytes_delivered++;
219             if (!de_state_size(eventByte, &de_header_state)) break;
220 
221             attribute_value_size = de_header_state.de_size + attribute_bytes_received;
222 
223             state = GET_ATTRIBUTE_VALUE;
224             break;
225 
226         case GET_ATTRIBUTE_VALUE:
227             attribute_bytes_received++;
228             sdp_parser_emit_value_byte(eventByte);
229             attribute_bytes_delivered++;
230             // log_info("paser: attribute_bytes_received %u, attribute_value_size %u", attribute_bytes_received, attribute_value_size);
231 
232             if (attribute_bytes_received < attribute_value_size) break;
233             // log_info("parser: Record offset %u, record size %u", record_offset, record_size);
234             if (record_offset != record_size){
235                 state = GET_ATTRIBUTE_ID_HEADER_LENGTH;
236                 // log_info("Get next attribute");
237                 break;
238             }
239             record_offset = 0;
240             // log_info("parser: List offset %u, list size %u", list_offset, list_size);
241 
242             if (list_size > 0 && list_offset != list_size){
243                 record_counter++;
244                 state = GET_RECORD_LENGTH;
245                 log_info("parser: END_OF_RECORD");
246                 break;
247             }
248             list_offset = 0;
249             de_state_init(&de_header_state);
250             state = GET_LIST_LENGTH;
251             record_counter = 0;
252             log_info("parser: END_OF_RECORD & DONE");
253             break;
254         default:
255             break;
256     }
257 }
258 
259 void sdp_parser_init(btstack_packet_handler_t callback){
260     // init
261     sdp_parser_callback = callback;
262     de_state_init(&de_header_state);
263     state = GET_LIST_LENGTH;
264     list_offset = 0;
265     record_offset = 0;
266     record_counter = 0;
267 }
268 
269 void sdp_parser_handle_chunk(uint8_t * data, uint16_t size){
270     int i;
271     for (i=0;i<size;i++){
272         sdp_parser_process_byte(data[i]);
273     }
274 }
275 
276 #ifdef ENABLE_SDP_EXTRA_QUERIES
277 void sdp_parser_init_service_attribute_search(void){
278     // init
279     de_state_init(&de_header_state);
280     state = GET_RECORD_LENGTH;
281     list_offset = 0;
282     record_offset = 0;
283     record_counter = 0;
284 }
285 
286 void sdp_parser_init_service_search(void){
287     record_offset = 0;
288 }
289 
290 void sdp_parser_handle_service_search(uint8_t * data, uint16_t total_count, uint16_t record_handle_count){
291     int i;
292     for (i=0;i<record_handle_count;i++){
293         record_handle = big_endian_read_32(data, i*4);
294         record_counter++;
295         uint8_t event[10];
296         event[0] = SDP_EVENT_QUERY_SERVICE_RECORD_HANDLE;
297         event[1] = 8;
298         little_endian_store_16(event, 2, total_count);
299         little_endian_store_16(event, 4, record_counter);
300         little_endian_store_32(event, 6, record_handle);
301         (*sdp_parser_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
302     }
303 }
304 #endif
305 
306 void sdp_parser_handle_done(uint8_t status){
307     uint8_t event[3];
308     event[0] = SDP_EVENT_QUERY_COMPLETE;
309     event[1] = 1;
310     event[2] = status;
311     (*sdp_parser_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
312 }
313 
314 // SDP Client
315 
316 // TODO: inline if not needed (des(des))
317 
318 static void sdp_client_parse_attribute_lists(uint8_t* packet, uint16_t length){
319     sdp_parser_handle_chunk(packet, length);
320 }
321 
322 
323 static void sdp_client_send_request(uint16_t channel){
324 
325     if (sdp_client_state != W2_SEND) return;
326 
327     l2cap_reserve_packet_buffer();
328     uint8_t * data = l2cap_get_outgoing_buffer();
329     uint16_t request_len = 0;
330 
331     switch (PDU_ID){
332 #ifdef ENABLE_SDP_EXTRA_QUERIES
333         case SDP_ServiceSearchResponse:
334             request_len = sdp_client_setup_service_search_request(data);
335             break;
336         case SDP_ServiceAttributeResponse:
337             request_len = sdp_client_setup_service_attribute_request(data);
338             break;
339 #endif
340         case SDP_ServiceSearchAttributeResponse:
341             request_len = sdp_client_setup_service_search_attribute_request(data);
342             break;
343         default:
344             log_error("SDP Client sdp_client_send_request :: PDU ID invalid. %u", PDU_ID);
345             return;
346     }
347 
348     // prevent re-entrance
349     sdp_client_state = W4_RESPONSE;
350     PDU_ID = SDP_Invalid;
351     l2cap_send_prepared(channel, request_len);
352 }
353 
354 
355 static void sdp_client_parse_service_search_attribute_response(uint8_t* packet){
356     uint16_t offset = 3;
357     uint16_t parameterLength = big_endian_read_16(packet,offset);
358     offset+=2;
359     // AttributeListByteCount <= mtu
360     uint16_t attributeListByteCount = big_endian_read_16(packet,offset);
361     offset+=2;
362 
363     if (attributeListByteCount > mtu){
364         log_error("Error parsing ServiceSearchAttributeResponse: Number of bytes in found attribute list is larger then the MaximumAttributeByteCount.");
365         return;
366     }
367 
368     // AttributeLists
369     sdp_client_parse_attribute_lists(packet+offset, attributeListByteCount);
370     offset+=attributeListByteCount;
371 
372     continuationStateLen = packet[offset];
373     offset++;
374 
375     if (continuationStateLen > 16){
376         log_error("Error parsing ServiceSearchAttributeResponse: Number of bytes in continuation state exceedes 16.");
377         return;
378     }
379     memcpy(continuationState, packet+offset, continuationStateLen);
380     offset+=continuationStateLen;
381 
382     if (parameterLength != offset - 5){
383         log_error("Error parsing ServiceSearchAttributeResponse: wrong size of parameters, number of expected bytes%u, actual number %u.", parameterLength, offset);
384     }
385 }
386 
387 void sdp_client_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
388     UNUSED(size);
389 
390     // uint16_t handle;
391     if (packet_type == L2CAP_DATA_PACKET){
392         uint16_t responseTransactionID = big_endian_read_16(packet,1);
393         if ( responseTransactionID != transactionID){
394             log_error("Missmatching transaction ID, expected %u, found %u.", transactionID, responseTransactionID);
395             return;
396         }
397 
398         if (packet[0] != SDP_ServiceSearchAttributeResponse
399             && packet[0] != SDP_ServiceSearchResponse
400             && packet[0] != SDP_ServiceAttributeResponse){
401             log_error("Not a valid PDU ID, expected %u, %u or %u, found %u.", SDP_ServiceSearchResponse,
402                                     SDP_ServiceAttributeResponse, SDP_ServiceSearchAttributeResponse, packet[0]);
403             return;
404         }
405 
406         PDU_ID = (SDP_PDU_ID_t)packet[0];
407         log_info("SDP Client :: PDU ID. %u ,%u", PDU_ID, packet[0]);
408         switch (PDU_ID){
409 #ifdef ENABLE_SDP_EXTRA_QUERIES
410             case SDP_ServiceSearchResponse:
411                 sdp_client_parse_service_search_response(packet);
412                 break;
413             case SDP_ServiceAttributeResponse:
414                 sdp_client_parse_service_attribute_response(packet);
415                 break;
416 #endif
417             case SDP_ServiceSearchAttributeResponse:
418                 sdp_client_parse_service_search_attribute_response(packet);
419                 break;
420             default:
421                 log_error("SDP Client :: PDU ID invalid. %u ,%u", PDU_ID, packet[0]);
422                 return;
423         }
424 
425         // continuation set or DONE?
426         if (continuationStateLen == 0){
427             log_info("SDP Client Query DONE! ");
428             sdp_client_state = QUERY_COMPLETE;
429             l2cap_disconnect(sdp_cid, 0);
430             // sdp_parser_handle_done(0);
431             return;
432         }
433         // prepare next request and send
434         sdp_client_state = W2_SEND;
435         l2cap_request_can_send_now_event(sdp_cid);
436         return;
437     }
438 
439     if (packet_type != HCI_EVENT_PACKET) return;
440 
441     switch(hci_event_packet_get_type(packet)){
442         case L2CAP_EVENT_CHANNEL_OPENED:
443             if (sdp_client_state != W4_CONNECT) break;
444             // data: event (8), len(8), status (8), address(48), handle (16), psm (16), local_cid(16), remote_cid (16), local_mtu(16), remote_mtu(16)
445             if (packet[2]) {
446                 log_error("SDP Client Connection failed.");
447                 sdp_parser_handle_done(packet[2]);
448                 break;
449             }
450             sdp_cid = channel;
451             mtu = little_endian_read_16(packet, 17);
452             // handle = little_endian_read_16(packet, 9);
453             log_info("SDP Client Connected, cid %x, mtu %u.", sdp_cid, mtu);
454 
455             sdp_client_state = W2_SEND;
456             l2cap_request_can_send_now_event(sdp_cid);
457             break;
458 
459         case L2CAP_EVENT_CAN_SEND_NOW:
460             if(l2cap_event_can_send_now_get_local_cid(packet) == sdp_cid){
461                 sdp_client_send_request(sdp_cid);
462             }
463             break;
464         case L2CAP_EVENT_CHANNEL_CLOSED: {
465             if (sdp_cid != little_endian_read_16(packet, 2)) {
466                 // log_info("Received L2CAP_EVENT_CHANNEL_CLOSED for cid %x, current cid %x\n",  little_endian_read_16(packet, 2),sdp_cid);
467                 break;
468             }
469             log_info("SDP Client disconnected.");
470             uint8_t status = sdp_client_state == QUERY_COMPLETE ? 0 : SDP_QUERY_INCOMPLETE;
471             sdp_client_state = INIT;
472             sdp_parser_handle_done(status);
473             break;
474         }
475         default:
476             break;
477     }
478 }
479 
480 
481 static uint16_t sdp_client_setup_service_search_attribute_request(uint8_t * data){
482 
483     uint16_t offset = 0;
484     transactionID++;
485     // uint8_t SDP_PDU_ID_t.SDP_ServiceSearchRequest;
486     data[offset++] = SDP_ServiceSearchAttributeRequest;
487     // uint16_t transactionID
488     big_endian_store_16(data, offset, transactionID);
489     offset += 2;
490 
491     // param legnth
492     offset += 2;
493 
494     // parameters:
495     //     Service_search_pattern - DES (min 1 UUID, max 12)
496     uint16_t service_search_pattern_len = de_get_len(service_search_pattern);
497     memcpy(data + offset, service_search_pattern, service_search_pattern_len);
498     offset += service_search_pattern_len;
499 
500     //     MaximumAttributeByteCount - uint16_t  0x0007 - 0xffff -> mtu
501     big_endian_store_16(data, offset, mtu);
502     offset += 2;
503 
504     //     AttibuteIDList
505     uint16_t attribute_id_list_len = de_get_len(attribute_id_list);
506     memcpy(data + offset, attribute_id_list, attribute_id_list_len);
507     offset += attribute_id_list_len;
508 
509     //     ContinuationState - uint8_t number of cont. bytes N<=16
510     data[offset++] = continuationStateLen;
511     //                       - N-bytes previous response from server
512     memcpy(data + offset, continuationState, continuationStateLen);
513     offset += continuationStateLen;
514 
515     // uint16_t paramLength
516     big_endian_store_16(data, 3, offset - 5);
517 
518     return offset;
519 }
520 
521 #ifdef ENABLE_SDP_EXTRA_QUERIES
522 void sdp_client_parse_service_record_handle_list(uint8_t* packet, uint16_t total_count, uint16_t current_count){
523     sdp_parser_handle_service_search(packet, total_count, current_count);
524 }
525 
526 static uint16_t sdp_client_setup_service_search_request(uint8_t * data){
527     uint16_t offset = 0;
528     transactionID++;
529     // uint8_t SDP_PDU_ID_t.SDP_ServiceSearchRequest;
530     data[offset++] = SDP_ServiceSearchRequest;
531     // uint16_t transactionID
532     big_endian_store_16(data, offset, transactionID);
533     offset += 2;
534 
535     // param legnth
536     offset += 2;
537 
538     // parameters:
539     //     Service_search_pattern - DES (min 1 UUID, max 12)
540     uint16_t service_search_pattern_len = de_get_len(service_search_pattern);
541     memcpy(data + offset, service_search_pattern, service_search_pattern_len);
542     offset += service_search_pattern_len;
543 
544     //     MaximumAttributeByteCount - uint16_t  0x0007 - 0xffff -> mtu
545     big_endian_store_16(data, offset, mtu);
546     offset += 2;
547 
548     //     ContinuationState - uint8_t number of cont. bytes N<=16
549     data[offset++] = continuationStateLen;
550     //                       - N-bytes previous response from server
551     memcpy(data + offset, continuationState, continuationStateLen);
552     offset += continuationStateLen;
553 
554     // uint16_t paramLength
555     big_endian_store_16(data, 3, offset - 5);
556 
557     return offset;
558 }
559 
560 
561 static uint16_t sdp_client_setup_service_attribute_request(uint8_t * data){
562 
563     uint16_t offset = 0;
564     transactionID++;
565     // uint8_t SDP_PDU_ID_t.SDP_ServiceSearchRequest;
566     data[offset++] = SDP_ServiceAttributeRequest;
567     // uint16_t transactionID
568     big_endian_store_16(data, offset, transactionID);
569     offset += 2;
570 
571     // param legnth
572     offset += 2;
573 
574     // parameters:
575     //     ServiceRecordHandle
576     big_endian_store_32(data, offset, serviceRecordHandle);
577     offset += 4;
578 
579     //     MaximumAttributeByteCount - uint16_t  0x0007 - 0xffff -> mtu
580     big_endian_store_16(data, offset, mtu);
581     offset += 2;
582 
583     //     AttibuteIDList
584     uint16_t attribute_id_list_len = de_get_len(attribute_id_list);
585     memcpy(data + offset, attribute_id_list, attribute_id_list_len);
586     offset += attribute_id_list_len;
587 
588     //     ContinuationState - uint8_t number of cont. bytes N<=16
589     data[offset++] = continuationStateLen;
590     //                       - N-bytes previous response from server
591     memcpy(data + offset, continuationState, continuationStateLen);
592     offset += continuationStateLen;
593 
594     // uint16_t paramLength
595     big_endian_store_16(data, 3, offset - 5);
596 
597     return offset;
598 }
599 
600 static void sdp_client_parse_service_search_response(uint8_t* packet){
601     uint16_t offset = 3;
602     uint16_t parameterLength = big_endian_read_16(packet,offset);
603     offset+=2;
604 
605     uint16_t totalServiceRecordCount = big_endian_read_16(packet,offset);
606     offset+=2;
607 
608     uint16_t currentServiceRecordCount = big_endian_read_16(packet,offset);
609     offset+=2;
610     if (currentServiceRecordCount > totalServiceRecordCount){
611         log_error("CurrentServiceRecordCount is larger then TotalServiceRecordCount.");
612         return;
613     }
614 
615     sdp_client_parse_service_record_handle_list(packet+offset, totalServiceRecordCount, currentServiceRecordCount);
616     offset+=(currentServiceRecordCount * 4);
617 
618     continuationStateLen = packet[offset];
619     offset++;
620     if (continuationStateLen > 16){
621         log_error("Error parsing ServiceSearchResponse: Number of bytes in continuation state exceedes 16.");
622         return;
623     }
624     memcpy(continuationState, packet+offset, continuationStateLen);
625     offset+=continuationStateLen;
626 
627     if (parameterLength != offset - 5){
628         log_error("Error parsing ServiceSearchResponse: wrong size of parameters, number of expected bytes%u, actual number %u.", parameterLength, offset);
629     }
630 }
631 
632 static void sdp_client_parse_service_attribute_response(uint8_t* packet){
633     uint16_t offset = 3;
634     uint16_t parameterLength = big_endian_read_16(packet,offset);
635     offset+=2;
636 
637     // AttributeListByteCount <= mtu
638     uint16_t attributeListByteCount = big_endian_read_16(packet,offset);
639     offset+=2;
640 
641     if (attributeListByteCount > mtu){
642         log_error("Error parsing ServiceSearchAttributeResponse: Number of bytes in found attribute list is larger then the MaximumAttributeByteCount.");
643         return;
644     }
645 
646     // AttributeLists
647     sdp_client_parse_attribute_lists(packet+offset, attributeListByteCount);
648     offset+=attributeListByteCount;
649 
650     continuationStateLen = packet[offset];
651     offset++;
652 
653     if (continuationStateLen > 16){
654         log_error("Error parsing ServiceAttributeResponse: Number of bytes in continuation state exceedes 16.");
655         return;
656     }
657     memcpy(continuationState, packet+offset, continuationStateLen);
658     offset+=continuationStateLen;
659 
660     if (parameterLength != offset - 5){
661         log_error("Error parsing ServiceAttributeResponse: wrong size of parameters, number of expected bytes%u, actual number %u.", parameterLength, offset);
662     }
663 }
664 #endif
665 
666 // for testing only
667 void sdp_client_reset(void){
668     sdp_client_state = INIT;
669 }
670 
671 // Public API
672 
673 int sdp_client_ready(void){
674     return sdp_client_state == INIT;
675 }
676 
677 uint8_t sdp_client_query(btstack_packet_handler_t callback, bd_addr_t remote, const uint8_t * des_service_search_pattern, const uint8_t * des_attribute_id_list){
678 
679     if (!sdp_client_ready()) return SDP_QUERY_BUSY;
680 
681     sdp_parser_init(callback);
682     service_search_pattern = des_service_search_pattern;
683     attribute_id_list = des_attribute_id_list;
684     continuationStateLen = 0;
685     PDU_ID = SDP_ServiceSearchAttributeResponse;
686 
687     sdp_client_state = W4_CONNECT;
688     l2cap_create_channel(sdp_client_packet_handler, remote, PSM_SDP, l2cap_max_mtu(), NULL);
689     return 0;
690 }
691 
692 uint8_t sdp_client_query_uuid16(btstack_packet_handler_t callback, bd_addr_t remote, uint16_t uuid){
693 
694     if (!sdp_client_ready()) return SDP_QUERY_BUSY;
695 
696     uint8_t * service_service_search_pattern = sdp_service_search_pattern_for_uuid16(uuid);
697     return sdp_client_query(callback, remote, service_service_search_pattern, des_attributeIDList);
698 }
699 
700 uint8_t sdp_client_query_uuid128(btstack_packet_handler_t callback, bd_addr_t remote, const uint8_t* uuid){
701 
702     if (!sdp_client_ready()) return SDP_QUERY_BUSY;
703 
704     uint8_t * service_service_search_pattern = sdp_service_search_pattern_for_uuid128(uuid);
705     return sdp_client_query(callback, remote, service_service_search_pattern, des_attributeIDList);
706 }
707 
708 #ifdef ENABLE_SDP_EXTRA_QUERIES
709 uint8_t sdp_client_service_attribute_search(btstack_packet_handler_t callback, bd_addr_t remote, uint32_t search_service_record_handle, uint8_t * des_attribute_id_list){
710 
711     if (!sdp_client_ready()) return SDP_QUERY_BUSY;
712 
713     sdp_parser_init(callback);
714     serviceRecordHandle = search_service_record_handle;
715     attribute_id_list = des_attribute_id_list;
716     continuationStateLen = 0;
717     PDU_ID = SDP_ServiceAttributeResponse;
718 
719     sdp_client_state = W4_CONNECT;
720     l2cap_create_channel(sdp_client_packet_handler, remote, PSM_SDP, l2cap_max_mtu(), NULL);
721     return 0;
722 }
723 
724 uint8_t sdp_client_service_search(btstack_packet_handler_t callback, bd_addr_t remote, uint8_t * des_service_search_pattern){
725 
726     if (!sdp_client_ready()) return SDP_QUERY_BUSY;
727 
728     sdp_parser_init(callback);
729     service_search_pattern = des_service_search_pattern;
730     continuationStateLen = 0;
731     PDU_ID = SDP_ServiceSearchResponse;
732 
733     sdp_client_state = W4_CONNECT;
734     l2cap_create_channel(sdp_client_packet_handler, remote, PSM_SDP, l2cap_max_mtu(), NULL);
735     return 0;
736 }
737 #endif
738 
739