xref: /btstack/src/classic/sdp_util.c (revision d40c3de009bce6994e726da5a427e08951b353d9)
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 #define __BTSTACK_FILE__ "sdp_util.c"
39 
40 /*
41  *  sdp_util.c
42  */
43 
44 #include "bluetooth.h"
45 #include "btstack_config.h"
46 #include "btstack_util.h"
47 #include "classic/core.h"
48 #include "classic/sdp_util.h"
49 
50 #include <stdio.h>
51 #include <stdlib.h>
52 #include <string.h>
53 #include <stdint.h>
54 #include <inttypes.h>   // PRIx32
55 
56 #ifdef ENABLE_SDP_DES_DUMP
57 // workaround for missing PRIx32 on mspgcc (16-bit MCU)
58 #ifndef PRIx32
59 #warning Using own: #define PRIx32 "lx"
60 #define PRIx32 "lx"
61 #endif
62 // date element type names
63 const char * const type_names[] = { "NIL", "UINT", "INT", "UUID", "STRING", "BOOL", "DES", "DEA", "URL"};
64 #endif
65 
66 static uint8_t des_serviceSearchPatternUUID16[]  = {0x35, 0x03, 0x19, 0x00, 0x00};
67 static uint8_t des_serviceSearchPatternUUID128[] = {
68     0x35, 0x11, 0x1c,
69     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
70     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
71 
72 // MARK: DataElement getter
73 de_size_t de_get_size_type(const uint8_t *header){
74     return (de_size_t) (header[0] & 7);
75 }
76 
77 de_type_t de_get_element_type(const uint8_t *header){
78     return (de_type_t) (header[0] >> 3);
79 }
80 
81 int de_get_header_size(const uint8_t * header){
82     de_size_t de_size = de_get_size_type(header);
83     if (de_size <= DE_SIZE_128) {
84         return 1;
85     }
86     return 1 + (1 << (de_size-DE_SIZE_VAR_8));
87 }
88 
89 int de_get_data_size(const uint8_t * header){
90     uint32_t result = 0;
91     de_type_t de_type = de_get_element_type(header);
92     de_size_t de_size = de_get_size_type(header);
93     switch (de_size){
94         case DE_SIZE_VAR_8:
95             result = header[1];
96             break;
97         case DE_SIZE_VAR_16:
98             result = big_endian_read_16(header,1);
99             break;
100         case DE_SIZE_VAR_32:
101             result = big_endian_read_32(header,1);
102             break;
103         default:
104         // case DE_SIZE_8:
105         // case DE_SIZE_16:
106         // case DE_SIZE_32:
107         // case DE_SIZE_64:
108         // case DE_SIZE_128:
109             if (de_type == DE_NIL) return 0;
110             return 1 << de_size;
111     }
112     return result;
113 }
114 
115 int de_get_len(const uint8_t *header){
116     return de_get_header_size(header) + de_get_data_size(header);
117 }
118 
119 // @returns OK, if UINT16 value was read
120 int de_element_get_uint16(const uint8_t * element, uint16_t * value){
121     if (de_get_size_type(element) != DE_SIZE_16) return 0;
122     *value = big_endian_read_16(element, de_get_header_size(element));
123     return 1;
124 }
125 
126 // @returns: element is valid UUID
127 int de_get_normalized_uuid(uint8_t *uuid128, const uint8_t *element){
128     de_type_t uuidType = de_get_element_type(element);
129     de_size_t uuidSize = de_get_size_type(element);
130     if (uuidType != DE_UUID) return 0;
131     uint32_t shortUUID;
132     switch (uuidSize){
133         case DE_SIZE_16:
134             shortUUID = big_endian_read_16(element, 1);
135             break;
136         case DE_SIZE_32:
137             shortUUID = big_endian_read_32(element, 1);
138             break;
139         case DE_SIZE_128:
140             memcpy(uuid128, element+1, 16);
141             return 1;
142         default:
143             return 0;
144     }
145     uuid_add_bluetooth_prefix(uuid128, shortUUID);
146     return 1;
147 }
148 
149 // @returns 0 if no UUID16 or UUID32 is present, and UUID32 otherwise
150 uint32_t de_get_uuid32(const uint8_t * element){
151     uint8_t uuid128[16];
152     int validUuid128 = de_get_normalized_uuid(uuid128, element);
153     if (!validUuid128) return 0;
154     int hasBlueoothBaseUuid = uuid_has_bluetooth_prefix(uuid128);
155     if (!hasBlueoothBaseUuid) return 0;
156     return big_endian_read_32(uuid128, 0);
157 }
158 
159 // functions to create record
160 static void de_store_descriptor(uint8_t * header, de_type_t type, de_size_t size){
161     header[0] = (type << 3) | size;
162 }
163 
164 void de_store_descriptor_with_len(uint8_t * header, de_type_t type, de_size_t size, uint32_t len){
165     header[0] = (type << 3) | size;
166     switch (size){
167         case DE_SIZE_VAR_8:
168             header[1] = len;
169             break;
170         case DE_SIZE_VAR_16:
171             big_endian_store_16(header, 1, len);
172             break;
173         case DE_SIZE_VAR_32:
174             big_endian_store_32(header, 1, len);
175             break;
176         default:
177             break;
178     }
179 }
180 
181 // MARK: DataElement creation
182 
183 /* starts a new sequence in empty buffer - first call */
184 void de_create_sequence(uint8_t *header){
185     de_store_descriptor_with_len( header, DE_DES, DE_SIZE_VAR_16, 0); // DES, 2 Byte Length
186 };
187 
188 /* starts a sub-sequence, @returns handle for sub-sequence */
189 uint8_t * de_push_sequence(uint8_t *header){
190     int element_len = de_get_len(header);
191     de_store_descriptor_with_len(header+element_len, DE_DES, DE_SIZE_VAR_16, 0); // DES, 2 Byte Length
192     return header + element_len;
193 }
194 
195 /* closes the current sequence and updates the parent sequence */
196 void de_pop_sequence(uint8_t * parent, uint8_t * child){
197     int child_len = de_get_len(child);
198     int data_size_parent = big_endian_read_16(parent,1);
199     big_endian_store_16(parent, 1, data_size_parent + child_len);
200 }
201 
202 /* adds a single number value and 16+32 bit UUID to the sequence */
203 void de_add_number(uint8_t *seq, de_type_t type, de_size_t size, uint32_t value){
204     int data_size   = big_endian_read_16(seq,1);
205     int element_size = 1;   // e.g. for DE_TYPE_NIL
206     de_store_descriptor(seq+3+data_size, type, size);
207     switch (size){
208         case DE_SIZE_8:
209             if (type != DE_NIL){
210                 seq[4+data_size] = value;
211                 element_size = 2;
212             }
213             break;
214         case DE_SIZE_16:
215             big_endian_store_16(seq, 4+data_size, value);
216             element_size = 3;
217             break;
218         case DE_SIZE_32:
219             big_endian_store_32(seq, 4+data_size, value);
220             element_size = 5;
221             break;
222         default:
223             break;
224     }
225     big_endian_store_16(seq, 1, data_size+element_size);
226 }
227 
228 /* add a single block of data, e.g. as DE_STRING, DE_URL */
229 void de_add_data( uint8_t *seq, de_type_t type, uint16_t size, uint8_t *data){
230     int data_size   = big_endian_read_16(seq,1);
231     if (size > 0xff) {
232         // use 16-bit lengh information (3 byte header)
233         de_store_descriptor_with_len(seq+3+data_size, type, DE_SIZE_VAR_16, size);
234         data_size += 3;
235     } else {
236         // use 8-bit lengh information (2 byte header)
237         de_store_descriptor_with_len(seq+3+data_size, type, DE_SIZE_VAR_8, size);
238         data_size += 2;
239     }
240     memcpy( seq + 3 + data_size, data, size);
241     data_size += size;
242     big_endian_store_16(seq, 1, data_size);
243 }
244 
245 void de_add_uuid128(uint8_t * seq, uint8_t * uuid){
246     int data_size   = big_endian_read_16(seq,1);
247     de_store_descriptor(seq+3+data_size, DE_UUID, DE_SIZE_128);
248     memcpy( seq + 4 + data_size, uuid, 16);
249     big_endian_store_16(seq, 1, data_size+1+16);
250 }
251 
252 // MARK: DES iterator
253 int des_iterator_init(des_iterator_t * it, uint8_t * element){
254     de_type_t type = de_get_element_type(element);
255     if (type != DE_DES) return 0;
256 
257     it->element = element;
258     it->pos = de_get_header_size(element);
259     it->length = de_get_len(element);
260     // printf("des_iterator_init current pos %d, total len %d\n", it->pos, it->length);
261     return 1;
262 }
263 
264 de_type_t des_iterator_get_type (des_iterator_t * it){
265     return de_get_element_type(&it->element[it->pos]);
266 }
267 
268 uint16_t des_iterator_get_size (des_iterator_t * it){
269     int length = de_get_len(&it->element[it->pos]);
270     int header_size = de_get_header_size(&it->element[it->pos]);
271     return length - header_size;
272 }
273 
274 int des_iterator_has_more(des_iterator_t * it){
275     return it->pos < it->length;
276 }
277 
278 uint8_t * des_iterator_get_element(des_iterator_t * it){
279     if (!des_iterator_has_more(it)) return NULL;
280     return &it->element[it->pos];
281 }
282 
283 void des_iterator_next(des_iterator_t * it){
284     int element_len = de_get_len(&it->element[it->pos]);
285     // printf("des_iterator_next element size %d, current pos %d, total len %d\n", element_len, it->pos, it->length);
286     it->pos += element_len;
287 }
288 
289 // MARK: DataElementSequence traversal
290 typedef int (*de_traversal_callback_t)(uint8_t * element, de_type_t type, de_size_t size, void *context);
291 static void de_traverse_sequence(uint8_t * element, de_traversal_callback_t handler, void *context){
292     de_type_t type = de_get_element_type(element);
293     if (type != DE_DES) return;
294     int pos = de_get_header_size(element);
295     int end_pos = de_get_len(element);
296     while (pos < end_pos){
297         de_type_t elemType = de_get_element_type(element + pos);
298         de_size_t elemSize = de_get_size_type(element + pos);
299         uint8_t done = (*handler)(element + pos, elemType, elemSize, context);
300         if (done) break;
301         pos += de_get_len(element + pos);
302     }
303 }
304 
305 // MARK: AttributeList traversal
306 typedef int (*sdp_attribute_list_traversal_callback_t)(uint16_t attributeID, uint8_t * attributeValue, de_type_t type, de_size_t size, void *context);
307 static void sdp_attribute_list_traverse_sequence(uint8_t * element, sdp_attribute_list_traversal_callback_t handler, void *context){
308     de_type_t type = de_get_element_type(element);
309     if (type != DE_DES) return;
310     int pos = de_get_header_size(element);
311     int end_pos = de_get_len(element);
312     while (pos < end_pos){
313         de_type_t idType = de_get_element_type(element + pos);
314         de_size_t idSize = de_get_size_type(element + pos);
315         if (idType != DE_UINT || idSize != DE_SIZE_16) break; // wrong type
316         uint16_t attribute_id = big_endian_read_16(element, pos + 1);
317         pos += 3;
318         if (pos >= end_pos) break; // array out of bounds
319         de_type_t valueType = de_get_element_type(element + pos);
320         de_size_t valueSize = de_get_size_type(element + pos);
321         uint8_t done = (*handler)(attribute_id, element + pos, valueType, valueSize, context);
322         if (done) break;
323         pos += de_get_len(element + pos);
324     }
325 }
326 
327 // MARK: AttributeID in AttributeIDList
328 // attribute ID in AttributeIDList
329 // context { result, attributeID }
330 struct sdp_context_attributeID_search {
331     int result;
332     uint16_t attributeID;
333 };
334 static int sdp_traversal_attributeID_search(uint8_t * element, de_type_t type, de_size_t size, void *my_context){
335     struct sdp_context_attributeID_search * context = (struct sdp_context_attributeID_search *) my_context;
336     if (type != DE_UINT) return 0;
337     switch (size) {
338         case DE_SIZE_16:
339             if (big_endian_read_16(element, 1) == context->attributeID) {
340                 context->result = 1;
341                 return 1;
342             }
343             break;
344         case DE_SIZE_32:
345             if (big_endian_read_16(element, 1) <= context->attributeID
346             &&  context->attributeID <= big_endian_read_16(element, 3)) {
347                 context->result = 1;
348                 return 1;
349             }
350             break;
351         default:
352             break;
353     }
354     return 0;
355 }
356 
357 int sdp_attribute_list_constains_id(uint8_t *attributeIDList, uint16_t attributeID){
358     struct sdp_context_attributeID_search attributeID_search;
359     attributeID_search.result = 0;
360     attributeID_search.attributeID = attributeID;
361     de_traverse_sequence(attributeIDList, sdp_traversal_attributeID_search, &attributeID_search);
362     return attributeID_search.result;
363 }
364 
365 // MARK: Append Attributes for AttributeIDList
366 // pre: buffer contains DES with 2 byte length field
367 struct sdp_context_append_attributes {
368     uint8_t * buffer;
369     uint16_t startOffset;     // offset of when to start copying
370     uint16_t maxBytes;
371     uint16_t usedBytes;
372     uint8_t *attributeIDList;
373 };
374 
375 static int sdp_traversal_append_attributes(uint16_t attributeID, uint8_t * attributeValue, de_type_t type, de_size_t size, void *my_context){
376     UNUSED(type);
377     UNUSED(size);
378     struct sdp_context_append_attributes * context = (struct sdp_context_append_attributes *) my_context;
379     if (sdp_attribute_list_constains_id(context->attributeIDList, attributeID)) {
380         // DES_HEADER(3) + DES_DATA + (UINT16(3) + attribute)
381         uint16_t data_size = big_endian_read_16(context->buffer, 1);
382         int attribute_len = de_get_len(attributeValue);
383         if (3 + data_size + (3 + attribute_len) <= context->maxBytes) {
384             // copy Attribute
385             de_add_number(context->buffer, DE_UINT, DE_SIZE_16, attributeID);
386             data_size += 3; // 3 bytes
387             memcpy(context->buffer + 3 + data_size, attributeValue, attribute_len);
388             big_endian_store_16(context->buffer,1,data_size+attribute_len);
389         } else {
390             // not enought space left -> continue with previous element
391             return 1;
392         }
393     }
394     return 0;
395 }
396 
397 // maxBytes: maximal size of data element sequence
398 uint16_t sdp_append_attributes_in_attributeIDList(uint8_t *record, uint8_t *attributeIDList, uint16_t startOffset, uint16_t maxBytes, uint8_t *buffer){
399     struct sdp_context_append_attributes context;
400     context.buffer = buffer;
401     context.maxBytes = maxBytes;
402     context.usedBytes = 0;
403     context.startOffset = startOffset;
404     context.attributeIDList = attributeIDList;
405     sdp_attribute_list_traverse_sequence(record, sdp_traversal_append_attributes, &context);
406     return context.usedBytes;
407 }
408 
409 // MARK: Filter attributes that match attribute list from startOffset and a max nr bytes
410 struct sdp_context_filter_attributes {
411     uint8_t * buffer;
412     uint16_t startOffset;     // offset of when to start copying
413     uint16_t maxBytes;
414     uint16_t usedBytes;
415     uint8_t *attributeIDList;
416     int      complete;
417 };
418 
419 // copy data with given start offset and max bytes, returns OK if all data has been copied
420 static int spd_append_range(struct sdp_context_filter_attributes* context, uint16_t len, uint8_t *data){
421     int ok = 1;
422     uint16_t remainder_len = len - context->startOffset;
423     if (context->maxBytes < remainder_len){
424         remainder_len = context->maxBytes;
425         ok = 0;
426     }
427     memcpy(context->buffer, &data[context->startOffset], remainder_len);
428     context->usedBytes += remainder_len;
429     context->buffer    += remainder_len;
430     context->maxBytes  -= remainder_len;
431     context->startOffset = 0;
432     return ok;
433 }
434 
435 static int sdp_traversal_filter_attributes(uint16_t attributeID, uint8_t * attributeValue, de_type_t type, de_size_t size, void *my_context){
436     UNUSED(type);
437     UNUSED(size);
438 
439     struct sdp_context_filter_attributes * context = (struct sdp_context_filter_attributes *) my_context;
440 
441     if (!sdp_attribute_list_constains_id(context->attributeIDList, attributeID)) return 0;
442 
443     // { Attribute ID (Descriptor, big endian 16-bit ID), AttributeValue (data)}
444 
445     // handle Attribute ID
446     if (context->startOffset >= 3){
447         context->startOffset -= 3;
448     } else {
449         uint8_t idBuffer[3];
450         de_store_descriptor(idBuffer, DE_UINT,  DE_SIZE_16);
451         big_endian_store_16(idBuffer,1,attributeID);
452 
453         int ok = spd_append_range(context, 3, idBuffer);
454         if (!ok) {
455             context->complete = 0;
456             return 1;
457         }
458     }
459 
460     // handle Attribute Value
461     int attribute_len = de_get_len(attributeValue);
462     if (context->startOffset >= attribute_len) {
463         context->startOffset -= attribute_len;
464         return 0;
465     }
466 
467     int ok = spd_append_range(context, attribute_len, attributeValue);
468     if (!ok) {
469         context->complete = 0;
470         return 1;
471     }
472     return 0;
473 }
474 
475 int sdp_filter_attributes_in_attributeIDList(uint8_t *record, uint8_t *attributeIDList, uint16_t startOffset, uint16_t maxBytes, uint16_t *usedBytes, uint8_t *buffer){
476 
477     struct sdp_context_filter_attributes context;
478     context.buffer = buffer;
479     context.maxBytes = maxBytes;
480     context.usedBytes = 0;
481     context.startOffset = startOffset;
482     context.attributeIDList = attributeIDList;
483     context.complete = 1;
484 
485     sdp_attribute_list_traverse_sequence(record, sdp_traversal_filter_attributes, &context);
486 
487     *usedBytes = context.usedBytes;
488     return context.complete;
489 }
490 
491 // MARK: Get sum of attributes matching attribute list
492 struct sdp_context_get_filtered_size {
493     uint8_t *attributeIDList;
494     uint16_t size;
495 };
496 
497 static int sdp_traversal_get_filtered_size(uint16_t attributeID, uint8_t * attributeValue, de_type_t type, de_size_t size, void *my_context){
498     UNUSED(type);
499     UNUSED(size);
500 
501     struct sdp_context_get_filtered_size * context = (struct sdp_context_get_filtered_size *) my_context;
502     if (sdp_attribute_list_constains_id(context->attributeIDList, attributeID)) {
503         context->size += 3 + de_get_len(attributeValue);
504     }
505     return 0;
506 }
507 
508 int spd_get_filtered_size(uint8_t *record, uint8_t *attributeIDList){
509     struct sdp_context_get_filtered_size context;
510     context.size = 0;
511     context.attributeIDList = attributeIDList;
512     sdp_attribute_list_traverse_sequence(record, sdp_traversal_get_filtered_size, &context);
513     return context.size;
514 }
515 
516 // MARK: Get AttributeValue for AttributeID
517 // find attribute (ELEMENT) by ID
518 struct sdp_context_attribute_by_id {
519     uint16_t  attributeID;
520     uint8_t * attributeValue;
521 };
522 static int sdp_traversal_attribute_by_id(uint16_t attributeID, uint8_t * attributeValue, de_type_t attributeType, de_size_t size, void *my_context){
523     UNUSED(attributeType);
524     UNUSED(size);
525 
526     struct sdp_context_attribute_by_id * context = (struct sdp_context_attribute_by_id *) my_context;
527     if (attributeID == context->attributeID) {
528         context->attributeValue = attributeValue;
529         return 1;
530     }
531     return 0;
532 }
533 
534 uint8_t * sdp_get_attribute_value_for_attribute_id(uint8_t * record, uint16_t attributeID){
535     struct sdp_context_attribute_by_id context;
536     context.attributeValue = NULL;
537     context.attributeID = attributeID;
538     sdp_attribute_list_traverse_sequence(record, sdp_traversal_attribute_by_id, &context);
539     return context.attributeValue;
540 }
541 
542 // MARK: Set AttributeValue for AttributeID
543 struct sdp_context_set_attribute_for_id {
544     uint16_t  attributeID;
545     uint32_t  attributeValue;
546     uint8_t   attributeFound;
547 };
548 static int sdp_traversal_set_attribute_for_id(uint16_t attributeID, uint8_t * attributeValue, de_type_t attributeType, de_size_t size, void *my_context){
549     struct sdp_context_set_attribute_for_id * context = (struct sdp_context_set_attribute_for_id *) my_context;
550     if (attributeID == context->attributeID) {
551         context->attributeFound = 1;
552         switch (size){
553             case DE_SIZE_8:
554                 if (attributeType != DE_NIL){
555                     attributeValue[1] = context->attributeValue;
556                 }
557                 break;
558             case DE_SIZE_16:
559                 big_endian_store_16(attributeValue, 1, context->attributeValue);
560                 break;
561             case DE_SIZE_32:
562                 big_endian_store_32(attributeValue, 1, context->attributeValue);
563                 break;
564                 // Might want to support STRINGS to, copy upto original length
565             default:
566                 break;
567         }
568         return 1;
569     }
570     return 0;
571 }
572 uint8_t sdp_set_attribute_value_for_attribute_id(uint8_t * record, uint16_t attributeID, uint32_t value){
573     struct sdp_context_set_attribute_for_id context;
574     context.attributeID = attributeID;
575     context.attributeValue = value;
576     context.attributeFound = 0;
577     sdp_attribute_list_traverse_sequence(record, sdp_traversal_set_attribute_for_id, &context);
578     return context.attributeFound;
579 }
580 
581 // MARK: ServiceRecord contains UUID
582 // service record contains UUID
583 // context { normalizedUUID }
584 struct sdp_context_contains_uuid128 {
585     uint8_t * uuid128;
586     int result;
587 };
588 int sdp_record_contains_UUID128(uint8_t *record, uint8_t *uuid128);
589 static int sdp_traversal_contains_UUID128(uint8_t * element, de_type_t type, de_size_t size, void *my_context){
590     UNUSED(size);
591 
592     struct sdp_context_contains_uuid128 * context = (struct sdp_context_contains_uuid128 *) my_context;
593     uint8_t normalizedUUID[16];
594     if (type == DE_UUID){
595         uint8_t uuidOK = de_get_normalized_uuid(normalizedUUID, element);
596         context->result = uuidOK && memcmp(context->uuid128, normalizedUUID, 16) == 0;
597     }
598     if (type == DE_DES){
599         context->result = sdp_record_contains_UUID128(element, context->uuid128);
600     }
601     return context->result;
602 }
603 int sdp_record_contains_UUID128(uint8_t *record, uint8_t *uuid128){
604     struct sdp_context_contains_uuid128 context;
605     context.uuid128 = uuid128;
606     context.result = 0;
607     de_traverse_sequence(record, sdp_traversal_contains_UUID128, &context);
608     return context.result;
609 }
610 
611 // MARK: ServiceRecord matches SearchServicePattern
612 // if UUID in searchServicePattern is not found in record => false
613 // context { result, record }
614 struct sdp_context_match_pattern {
615     uint8_t * record;
616     int result;
617 };
618 
619 int sdp_traversal_match_pattern(uint8_t * element, de_type_t attributeType, de_size_t size, void *my_context){
620     UNUSED(attributeType);
621     UNUSED(size);
622 
623     struct sdp_context_match_pattern * context = (struct sdp_context_match_pattern *) my_context;
624     uint8_t normalizedUUID[16];
625     uint8_t uuidOK = de_get_normalized_uuid(normalizedUUID, element);
626     if (!uuidOK || !sdp_record_contains_UUID128(context->record, normalizedUUID)){
627         context->result = 0;
628         return 1;
629     }
630     return 0;
631 }
632 int sdp_record_matches_service_search_pattern(uint8_t *record, uint8_t *serviceSearchPattern){
633     struct sdp_context_match_pattern context;
634     context.record = record;
635     context.result = 1;
636     de_traverse_sequence(serviceSearchPattern, sdp_traversal_match_pattern, &context);
637     return context.result;
638 }
639 
640 // MARK: Dump DataElement
641 // context { indent }
642 #ifdef ENABLE_SDP_DES_DUMP
643 static int de_traversal_dump_data(uint8_t * element, de_type_t de_type, de_size_t de_size, void *my_context){
644     int indent = *(int*) my_context;
645     int i;
646     for (i=0; i<indent;i++) printf("    ");
647     unsigned int pos     = de_get_header_size(element);
648     unsigned int end_pos = de_get_len(element);
649     printf("type %5s (%u), element len %2u ", type_names[de_type], de_type, end_pos);
650     if (de_type == DE_DES) {
651 		printf("\n");
652         indent++;
653         de_traverse_sequence(element, de_traversal_dump_data, (void *)&indent);
654     } else if (de_type == DE_UUID && de_size == DE_SIZE_128) {
655         printf(", value: %s\n", uuid128_to_str(element+1));
656     } else if (de_type == DE_STRING) {
657         unsigned int len = 0;
658         switch (de_size){
659             case DE_SIZE_VAR_8:
660                 len = element[1];
661                 break;
662             case DE_SIZE_VAR_16:
663                 len = big_endian_read_16(element, 1);
664                 break;
665             default:
666                 break;
667         }
668         printf("len %u (0x%02x)\n", len, len);
669         printf_hexdump(&element[pos], len);
670     } else {
671         uint32_t value = 0;
672         switch (de_size) {
673             case DE_SIZE_8:
674                 if (de_type != DE_NIL){
675                     value = element[pos];
676                 }
677                 break;
678             case DE_SIZE_16:
679 				value = big_endian_read_16(element,pos);
680                 break;
681             case DE_SIZE_32:
682 				value = big_endian_read_32(element,pos);
683                 break;
684             default:
685                 break;
686         }
687         printf(", value: 0x%08" PRIx32 "\n", value);
688     }
689     return 0;
690 }
691 #endif
692 
693 void de_dump_data_element(const uint8_t * record){
694 #ifdef ENABLE_SDP_DES_DUMP
695     int indent = 0;
696     // hack to get root DES, too.
697     de_type_t type = de_get_element_type(record);
698     de_size_t size = de_get_size_type(record);
699     de_traversal_dump_data((uint8_t *) record, type, size, (void*) &indent);
700 #endif
701 }
702 
703 uint8_t* sdp_service_search_pattern_for_uuid16(uint16_t uuid16){
704     big_endian_store_16(des_serviceSearchPatternUUID16, 3, uuid16);
705     return (uint8_t*)des_serviceSearchPatternUUID16;
706 }
707 
708 uint8_t* sdp_service_search_pattern_for_uuid128(const uint8_t * uuid128){
709     memcpy(&des_serviceSearchPatternUUID128[3], uuid128, 16);
710     return (uint8_t*)des_serviceSearchPatternUUID128;
711 }
712 
713