xref: /btstack/src/classic/sdp_util.c (revision efda0b48f920fa795cb4c2d0cf0c4acf184fb858)
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_util.c
40  */
41 
42 #include "classic/sdp_util.h"
43 #include "btstack_util.h"
44 #include "btstack_config.h"
45 #include "bluetooth.h"
46 
47 #include <stdio.h>
48 #include <stdlib.h>
49 #include <string.h>
50 #include <stdint.h>
51 #include <inttypes.h>   // PRIx32
52 
53 #ifdef ENABLE_SDP_DES_DUMP
54 // workaround for missing PRIx32 on mspgcc (16-bit MCU)
55 #ifndef PRIx32
56 #warning Using own: #define PRIx32 "lx"
57 #define PRIx32 "lx"
58 #endif
59 // date element type names
60 const char * const type_names[] = { "NIL", "UINT", "INT", "UUID", "STRING", "BOOL", "DES", "DEA", "URL"};
61 #endif
62 
63 static uint8_t des_serviceSearchPattern[] = {0x35, 0x03, 0x19, 0x00, 0x00};
64 static uint8_t des_serviceSearchPatternUUID128[] = {
65     0x35, 0x10, 0x19,
66     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
67     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
68 
69 // MARK: DataElement getter
70 de_size_t de_get_size_type(const uint8_t *header){
71     return (de_size_t) (header[0] & 7);
72 }
73 
74 de_type_t de_get_element_type(const uint8_t *header){
75     return (de_type_t) (header[0] >> 3);
76 }
77 
78 int de_get_header_size(const uint8_t * header){
79     de_size_t de_size = de_get_size_type(header);
80     if (de_size <= DE_SIZE_128) {
81         return 1;
82     }
83     return 1 + (1 << (de_size-DE_SIZE_VAR_8));
84 }
85 
86 int de_get_data_size(const uint8_t * header){
87     uint32_t result = 0;
88     de_type_t de_type = de_get_element_type(header);
89     de_size_t de_size = de_get_size_type(header);
90     switch (de_size){
91         case DE_SIZE_VAR_8:
92             result = header[1];
93             break;
94         case DE_SIZE_VAR_16:
95             result = big_endian_read_16(header,1);
96             break;
97         case DE_SIZE_VAR_32:
98             result = big_endian_read_32(header,1);
99             break;
100         default:
101         // case DE_SIZE_8:
102         // case DE_SIZE_16:
103         // case DE_SIZE_32:
104         // case DE_SIZE_64:
105         // case DE_SIZE_128:
106             if (de_type == DE_NIL) return 0;
107             return 1 << de_size;
108     }
109     return result;
110 }
111 
112 int de_get_len(const uint8_t *header){
113     return de_get_header_size(header) + de_get_data_size(header);
114 }
115 
116 // @returns OK, if UINT16 value was read
117 int de_element_get_uint16(const uint8_t * element, uint16_t * value){
118     if (de_get_size_type(element) != DE_SIZE_16) return 0;
119     *value = big_endian_read_16(element, de_get_header_size(element));
120     return 1;
121 }
122 
123 // @returns: element is valid UUID
124 int de_get_normalized_uuid(uint8_t *uuid128, const uint8_t *element){
125     de_type_t uuidType = de_get_element_type(element);
126     de_size_t uuidSize = de_get_size_type(element);
127     if (uuidType != DE_UUID) return 0;
128     uint32_t shortUUID;
129     switch (uuidSize){
130         case DE_SIZE_16:
131             shortUUID = big_endian_read_16(element, 1);
132             break;
133         case DE_SIZE_32:
134             shortUUID = big_endian_read_32(element, 1);
135             break;
136         case DE_SIZE_128:
137             memcpy(uuid128, element+1, 16);
138             return 1;
139         default:
140             return 0;
141     }
142     uuid_add_bluetooth_prefix(uuid128, shortUUID);
143     return 1;
144 }
145 
146 // @returns 0 if no UUID16 or UUID32 is present, and UUID32 otherwise
147 uint32_t de_get_uuid32(const uint8_t * element){
148     uint8_t uuid128[16];
149     int validUuid128 = de_get_normalized_uuid(uuid128, element);
150     if (!validUuid128) return 0;
151     int hasBlueoothBaseUuid = uuid_has_bluetooth_prefix(uuid128);
152     if (!hasBlueoothBaseUuid) return 0;
153     return big_endian_read_32(uuid128, 0);
154 }
155 
156 // functions to create record
157 static void de_store_descriptor(uint8_t * header, de_type_t type, de_size_t size){
158     header[0] = (type << 3) | size;
159 }
160 
161 void de_store_descriptor_with_len(uint8_t * header, de_type_t type, de_size_t size, uint32_t len){
162     header[0] = (type << 3) | size;
163     switch (size){
164         case DE_SIZE_VAR_8:
165             header[1] = len;
166             break;
167         case DE_SIZE_VAR_16:
168             big_endian_store_16(header, 1, len);
169             break;
170         case DE_SIZE_VAR_32:
171             big_endian_store_32(header, 1, len);
172             break;
173         default:
174             break;
175     }
176 }
177 
178 // MARK: DataElement creation
179 
180 /* starts a new sequence in empty buffer - first call */
181 void de_create_sequence(uint8_t *header){
182     de_store_descriptor_with_len( header, DE_DES, DE_SIZE_VAR_16, 0); // DES, 2 Byte Length
183 };
184 
185 /* starts a sub-sequence, @returns handle for sub-sequence */
186 uint8_t * de_push_sequence(uint8_t *header){
187     int element_len = de_get_len(header);
188     de_store_descriptor_with_len(header+element_len, DE_DES, DE_SIZE_VAR_16, 0); // DES, 2 Byte Length
189     return header + element_len;
190 }
191 
192 /* closes the current sequence and updates the parent sequence */
193 void de_pop_sequence(uint8_t * parent, uint8_t * child){
194     int child_len = de_get_len(child);
195     int data_size_parent = big_endian_read_16(parent,1);
196     big_endian_store_16(parent, 1, data_size_parent + child_len);
197 }
198 
199 /* adds a single number value and 16+32 bit UUID to the sequence */
200 void de_add_number(uint8_t *seq, de_type_t type, de_size_t size, uint32_t value){
201     int data_size   = big_endian_read_16(seq,1);
202     int element_size = 1;   // e.g. for DE_TYPE_NIL
203     de_store_descriptor(seq+3+data_size, type, size);
204     switch (size){
205         case DE_SIZE_8:
206             if (type != DE_NIL){
207                 seq[4+data_size] = value;
208                 element_size = 2;
209             }
210             break;
211         case DE_SIZE_16:
212             big_endian_store_16(seq, 4+data_size, value);
213             element_size = 3;
214             break;
215         case DE_SIZE_32:
216             big_endian_store_32(seq, 4+data_size, value);
217             element_size = 5;
218             break;
219         default:
220             break;
221     }
222     big_endian_store_16(seq, 1, data_size+element_size);
223 }
224 
225 /* add a single block of data, e.g. as DE_STRING, DE_URL */
226 void de_add_data( uint8_t *seq, de_type_t type, uint16_t size, uint8_t *data){
227     int data_size   = big_endian_read_16(seq,1);
228     if (size > 0xff) {
229         // use 16-bit lengh information (3 byte header)
230         de_store_descriptor_with_len(seq+3+data_size, type, DE_SIZE_VAR_16, size);
231         data_size += 3;
232     } else {
233         // use 8-bit lengh information (2 byte header)
234         de_store_descriptor_with_len(seq+3+data_size, type, DE_SIZE_VAR_8, size);
235         data_size += 2;
236     }
237     memcpy( seq + 3 + data_size, data, size);
238     data_size += size;
239     big_endian_store_16(seq, 1, data_size);
240 }
241 
242 void de_add_uuid128(uint8_t * seq, uint8_t * uuid){
243     int data_size   = big_endian_read_16(seq,1);
244     de_store_descriptor(seq+3+data_size, DE_UUID, DE_SIZE_128);
245     memcpy( seq + 4 + data_size, uuid, 16);
246     big_endian_store_16(seq, 1, data_size+1+16);
247 }
248 
249 // MARK: DES iterator
250 int des_iterator_init(des_iterator_t * it, uint8_t * element){
251     de_type_t type = de_get_element_type(element);
252     if (type != DE_DES) return 0;
253 
254     it->element = element;
255     it->pos = de_get_header_size(element);
256     it->length = de_get_len(element);
257     // printf("des_iterator_init current pos %d, total len %d\n", it->pos, it->length);
258     return 1;
259 }
260 
261 de_type_t des_iterator_get_type (des_iterator_t * it){
262     return de_get_element_type(&it->element[it->pos]);
263 }
264 
265 uint16_t des_iterator_get_size (des_iterator_t * it){
266     int length = de_get_len(&it->element[it->pos]);
267     int header_size = de_get_header_size(&it->element[it->pos]);
268     return length - header_size;
269 }
270 
271 int des_iterator_has_more(des_iterator_t * it){
272     return it->pos < it->length;
273 }
274 
275 uint8_t * des_iterator_get_element(des_iterator_t * it){
276     if (!des_iterator_has_more(it)) return NULL;
277     return &it->element[it->pos];
278 }
279 
280 void des_iterator_next(des_iterator_t * it){
281     int element_len = de_get_len(&it->element[it->pos]);
282     // printf("des_iterator_next element size %d, current pos %d, total len %d\n", element_len, it->pos, it->length);
283     it->pos += element_len;
284 }
285 
286 // MARK: DataElementSequence traversal
287 typedef int (*de_traversal_callback_t)(uint8_t * element, de_type_t type, de_size_t size, void *context);
288 static void de_traverse_sequence(uint8_t * element, de_traversal_callback_t handler, void *context){
289     de_type_t type = de_get_element_type(element);
290     if (type != DE_DES) return;
291     int pos = de_get_header_size(element);
292     int end_pos = de_get_len(element);
293     while (pos < end_pos){
294         de_type_t elemType = de_get_element_type(element + pos);
295         de_size_t elemSize = de_get_size_type(element + pos);
296         uint8_t done = (*handler)(element + pos, elemType, elemSize, context);
297         if (done) break;
298         pos += de_get_len(element + pos);
299     }
300 }
301 
302 // MARK: AttributeList traversal
303 typedef int (*sdp_attribute_list_traversal_callback_t)(uint16_t attributeID, uint8_t * attributeValue, de_type_t type, de_size_t size, void *context);
304 static void sdp_attribute_list_traverse_sequence(uint8_t * element, sdp_attribute_list_traversal_callback_t handler, void *context){
305     de_type_t type = de_get_element_type(element);
306     if (type != DE_DES) return;
307     int pos = de_get_header_size(element);
308     int end_pos = de_get_len(element);
309     while (pos < end_pos){
310         de_type_t idType = de_get_element_type(element + pos);
311         de_size_t idSize = de_get_size_type(element + pos);
312         if (idType != DE_UINT || idSize != DE_SIZE_16) break; // wrong type
313         uint16_t attribute_id = big_endian_read_16(element, pos + 1);
314         pos += 3;
315         if (pos >= end_pos) break; // array out of bounds
316         de_type_t valueType = de_get_element_type(element + pos);
317         de_size_t valueSize = de_get_size_type(element + pos);
318         uint8_t done = (*handler)(attribute_id, element + pos, valueType, valueSize, context);
319         if (done) break;
320         pos += de_get_len(element + pos);
321     }
322 }
323 
324 // MARK: AttributeID in AttributeIDList
325 // attribute ID in AttributeIDList
326 // context { result, attributeID }
327 struct sdp_context_attributeID_search {
328     int result;
329     uint16_t attributeID;
330 };
331 static int sdp_traversal_attributeID_search(uint8_t * element, de_type_t type, de_size_t size, void *my_context){
332     struct sdp_context_attributeID_search * context = (struct sdp_context_attributeID_search *) my_context;
333     if (type != DE_UINT) return 0;
334     switch (size) {
335         case DE_SIZE_16:
336             if (big_endian_read_16(element, 1) == context->attributeID) {
337                 context->result = 1;
338                 return 1;
339             }
340             break;
341         case DE_SIZE_32:
342             if (big_endian_read_16(element, 1) <= context->attributeID
343             &&  context->attributeID <= big_endian_read_16(element, 3)) {
344                 context->result = 1;
345                 return 1;
346             }
347             break;
348         default:
349             break;
350     }
351     return 0;
352 }
353 
354 int sdp_attribute_list_constains_id(uint8_t *attributeIDList, uint16_t attributeID){
355     struct sdp_context_attributeID_search attributeID_search;
356     attributeID_search.result = 0;
357     attributeID_search.attributeID = attributeID;
358     de_traverse_sequence(attributeIDList, sdp_traversal_attributeID_search, &attributeID_search);
359     return attributeID_search.result;
360 }
361 
362 // MARK: Append Attributes for AttributeIDList
363 // pre: buffer contains DES with 2 byte length field
364 struct sdp_context_append_attributes {
365     uint8_t * buffer;
366     uint16_t startOffset;     // offset of when to start copying
367     uint16_t maxBytes;
368     uint16_t usedBytes;
369     uint8_t *attributeIDList;
370 };
371 
372 static int sdp_traversal_append_attributes(uint16_t attributeID, uint8_t * attributeValue, de_type_t type, de_size_t size, void *my_context){
373     struct sdp_context_append_attributes * context = (struct sdp_context_append_attributes *) my_context;
374     if (sdp_attribute_list_constains_id(context->attributeIDList, attributeID)) {
375         // DES_HEADER(3) + DES_DATA + (UINT16(3) + attribute)
376         uint16_t data_size = big_endian_read_16(context->buffer, 1);
377         int attribute_len = de_get_len(attributeValue);
378         if (3 + data_size + (3 + attribute_len) <= context->maxBytes) {
379             // copy Attribute
380             de_add_number(context->buffer, DE_UINT, DE_SIZE_16, attributeID);
381             data_size += 3; // 3 bytes
382             memcpy(context->buffer + 3 + data_size, attributeValue, attribute_len);
383             big_endian_store_16(context->buffer,1,data_size+attribute_len);
384         } else {
385             // not enought space left -> continue with previous element
386             return 1;
387         }
388     }
389     return 0;
390 }
391 
392 // maxBytes: maximal size of data element sequence
393 uint16_t sdp_append_attributes_in_attributeIDList(uint8_t *record, uint8_t *attributeIDList, uint16_t startOffset, uint16_t maxBytes, uint8_t *buffer){
394     struct sdp_context_append_attributes context;
395     context.buffer = buffer;
396     context.maxBytes = maxBytes;
397     context.usedBytes = 0;
398     context.startOffset = startOffset;
399     context.attributeIDList = attributeIDList;
400     sdp_attribute_list_traverse_sequence(record, sdp_traversal_append_attributes, &context);
401     return context.usedBytes;
402 }
403 
404 // MARK: Filter attributes that match attribute list from startOffset and a max nr bytes
405 struct sdp_context_filter_attributes {
406     uint8_t * buffer;
407     uint16_t startOffset;     // offset of when to start copying
408     uint16_t maxBytes;
409     uint16_t usedBytes;
410     uint8_t *attributeIDList;
411     int      complete;
412 };
413 
414 // copy data with given start offset and max bytes, returns OK if all data has been copied
415 static int spd_append_range(struct sdp_context_filter_attributes* context, uint16_t len, uint8_t *data){
416     int ok = 1;
417     uint16_t remainder_len = len - context->startOffset;
418     if (context->maxBytes < remainder_len){
419         remainder_len = context->maxBytes;
420         ok = 0;
421     }
422     memcpy(context->buffer, &data[context->startOffset], remainder_len);
423     context->usedBytes += remainder_len;
424     context->buffer    += remainder_len;
425     context->maxBytes  -= remainder_len;
426     context->startOffset = 0;
427     return ok;
428 }
429 
430 static int sdp_traversal_filter_attributes(uint16_t attributeID, uint8_t * attributeValue, de_type_t type, de_size_t size, void *my_context){
431     struct sdp_context_filter_attributes * context = (struct sdp_context_filter_attributes *) my_context;
432 
433     if (!sdp_attribute_list_constains_id(context->attributeIDList, attributeID)) return 0;
434 
435     // { Attribute ID (Descriptor, big endian 16-bit ID), AttributeValue (data)}
436 
437     // handle Attribute ID
438     if (context->startOffset >= 3){
439         context->startOffset -= 3;
440     } else {
441         uint8_t idBuffer[3];
442         de_store_descriptor(idBuffer, DE_UINT,  DE_SIZE_16);
443         big_endian_store_16(idBuffer,1,attributeID);
444 
445         int ok = spd_append_range(context, 3, idBuffer);
446         if (!ok) {
447             context->complete = 0;
448             return 1;
449         }
450     }
451 
452     // handle Attribute Value
453     int attribute_len = de_get_len(attributeValue);
454     if (context->startOffset >= attribute_len) {
455         context->startOffset -= attribute_len;
456         return 0;
457     }
458 
459     int ok = spd_append_range(context, attribute_len, attributeValue);
460     if (!ok) {
461         context->complete = 0;
462         return 1;
463     }
464     return 0;
465 }
466 
467 int sdp_filter_attributes_in_attributeIDList(uint8_t *record, uint8_t *attributeIDList, uint16_t startOffset, uint16_t maxBytes, uint16_t *usedBytes, uint8_t *buffer){
468 
469     struct sdp_context_filter_attributes context;
470     context.buffer = buffer;
471     context.maxBytes = maxBytes;
472     context.usedBytes = 0;
473     context.startOffset = startOffset;
474     context.attributeIDList = attributeIDList;
475     context.complete = 1;
476 
477     sdp_attribute_list_traverse_sequence(record, sdp_traversal_filter_attributes, &context);
478 
479     *usedBytes = context.usedBytes;
480     return context.complete;
481 }
482 
483 // MARK: Get sum of attributes matching attribute list
484 struct sdp_context_get_filtered_size {
485     uint8_t *attributeIDList;
486     uint16_t size;
487 };
488 
489 static int sdp_traversal_get_filtered_size(uint16_t attributeID, uint8_t * attributeValue, de_type_t type, de_size_t size, void *my_context){
490     struct sdp_context_get_filtered_size * context = (struct sdp_context_get_filtered_size *) my_context;
491     if (sdp_attribute_list_constains_id(context->attributeIDList, attributeID)) {
492         context->size += 3 + de_get_len(attributeValue);
493     }
494     return 0;
495 }
496 
497 int spd_get_filtered_size(uint8_t *record, uint8_t *attributeIDList){
498     struct sdp_context_get_filtered_size context;
499     context.size = 0;
500     context.attributeIDList = attributeIDList;
501     sdp_attribute_list_traverse_sequence(record, sdp_traversal_get_filtered_size, &context);
502     return context.size;
503 }
504 
505 // MARK: Get AttributeValue for AttributeID
506 // find attribute (ELEMENT) by ID
507 struct sdp_context_attribute_by_id {
508     uint16_t  attributeID;
509     uint8_t * attributeValue;
510 };
511 static int sdp_traversal_attribute_by_id(uint16_t attributeID, uint8_t * attributeValue, de_type_t attributeType, de_size_t size, void *my_context){
512     struct sdp_context_attribute_by_id * context = (struct sdp_context_attribute_by_id *) my_context;
513     if (attributeID == context->attributeID) {
514         context->attributeValue = attributeValue;
515         return 1;
516     }
517     return 0;
518 }
519 
520 uint8_t * sdp_get_attribute_value_for_attribute_id(uint8_t * record, uint16_t attributeID){
521     struct sdp_context_attribute_by_id context;
522     context.attributeValue = NULL;
523     context.attributeID = attributeID;
524     sdp_attribute_list_traverse_sequence(record, sdp_traversal_attribute_by_id, &context);
525     return context.attributeValue;
526 }
527 
528 // MARK: Set AttributeValue for AttributeID
529 struct sdp_context_set_attribute_for_id {
530     uint16_t  attributeID;
531     uint32_t  attributeValue;
532     uint8_t   attributeFound;
533 };
534 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){
535     struct sdp_context_set_attribute_for_id * context = (struct sdp_context_set_attribute_for_id *) my_context;
536     if (attributeID == context->attributeID) {
537         context->attributeFound = 1;
538         switch (size){
539             case DE_SIZE_8:
540                 if (attributeType != DE_NIL){
541                     attributeValue[1] = context->attributeValue;
542                 }
543                 break;
544             case DE_SIZE_16:
545                 big_endian_store_16(attributeValue, 1, context->attributeValue);
546                 break;
547             case DE_SIZE_32:
548                 big_endian_store_32(attributeValue, 1, context->attributeValue);
549                 break;
550                 // Might want to support STRINGS to, copy upto original length
551             default:
552                 break;
553         }
554         return 1;
555     }
556     return 0;
557 }
558 uint8_t sdp_set_attribute_value_for_attribute_id(uint8_t * record, uint16_t attributeID, uint32_t value){
559     struct sdp_context_set_attribute_for_id context;
560     context.attributeID = attributeID;
561     context.attributeValue = value;
562     context.attributeFound = 0;
563     sdp_attribute_list_traverse_sequence(record, sdp_traversal_set_attribute_for_id, &context);
564     return context.attributeFound;
565 }
566 
567 // MARK: ServiceRecord contains UUID
568 // service record contains UUID
569 // context { normalizedUUID }
570 struct sdp_context_contains_uuid128 {
571     uint8_t * uuid128;
572     int result;
573 };
574 int sdp_record_contains_UUID128(uint8_t *record, uint8_t *uuid128);
575 static int sdp_traversal_contains_UUID128(uint8_t * element, de_type_t type, de_size_t size, void *my_context){
576     struct sdp_context_contains_uuid128 * context = (struct sdp_context_contains_uuid128 *) my_context;
577     uint8_t normalizedUUID[16];
578     if (type == DE_UUID){
579         uint8_t uuidOK = de_get_normalized_uuid(normalizedUUID, element);
580         context->result = uuidOK && memcmp(context->uuid128, normalizedUUID, 16) == 0;
581     }
582     if (type == DE_DES){
583         context->result = sdp_record_contains_UUID128(element, context->uuid128);
584     }
585     return context->result;
586 }
587 int sdp_record_contains_UUID128(uint8_t *record, uint8_t *uuid128){
588     struct sdp_context_contains_uuid128 context;
589     context.uuid128 = uuid128;
590     context.result = 0;
591     de_traverse_sequence(record, sdp_traversal_contains_UUID128, &context);
592     return context.result;
593 }
594 
595 // MARK: ServiceRecord matches SearchServicePattern
596 // if UUID in searchServicePattern is not found in record => false
597 // context { result, record }
598 struct sdp_context_match_pattern {
599     uint8_t * record;
600     int result;
601 };
602 
603 int sdp_traversal_match_pattern(uint8_t * element, de_type_t attributeType, de_size_t size, void *my_context){
604     struct sdp_context_match_pattern * context = (struct sdp_context_match_pattern *) my_context;
605     uint8_t normalizedUUID[16];
606     uint8_t uuidOK = de_get_normalized_uuid(normalizedUUID, element);
607     if (!uuidOK || !sdp_record_contains_UUID128(context->record, normalizedUUID)){
608         context->result = 0;
609         return 1;
610     }
611     return 0;
612 }
613 int sdp_record_matches_service_search_pattern(uint8_t *record, uint8_t *serviceSearchPattern){
614     struct sdp_context_match_pattern context;
615     context.record = record;
616     context.result = 1;
617     de_traverse_sequence(serviceSearchPattern, sdp_traversal_match_pattern, &context);
618     return context.result;
619 }
620 
621 // MARK: Dump DataElement
622 // context { indent }
623 #ifdef ENABLE_SDP_DES_DUMP
624 static int de_traversal_dump_data(uint8_t * element, de_type_t de_type, de_size_t de_size, void *my_context){
625     int indent = *(int*) my_context;
626     int i;
627     for (i=0; i<indent;i++) printf("    ");
628     int pos     = de_get_header_size(element);
629     int end_pos = de_get_len(element);
630     printf("type %5s (%u), element len %2u ", type_names[de_type], de_type, end_pos);
631     if (de_type == DE_DES) {
632 		printf("\n");
633         indent++;
634         de_traverse_sequence(element, de_traversal_dump_data, (void *)&indent);
635     } else if (de_type == DE_UUID && de_size == DE_SIZE_128) {
636         printf(", value: %s\n", uuid128_to_str(element+1));
637     } else if (de_type == DE_STRING) {
638         int len = 0;
639         switch (de_size){
640             case DE_SIZE_VAR_8:
641                 len = element[1];
642                 break;
643             case DE_SIZE_VAR_16:
644                 len = big_endian_read_16(element, 1);
645                 break;
646             default:
647                 break;
648         }
649         printf("len %u (0x%02x)\n", len, len);
650         printf_hexdump(&element[pos], len);
651     } else {
652         uint32_t value = 0;
653         switch (de_size) {
654             case DE_SIZE_8:
655                 if (de_type != DE_NIL){
656                     value = element[pos];
657                 }
658                 break;
659             case DE_SIZE_16:
660 				value = big_endian_read_16(element,pos);
661                 break;
662             case DE_SIZE_32:
663 				value = big_endian_read_32(element,pos);
664                 break;
665             default:
666                 break;
667         }
668         printf(", value: 0x%08" PRIx32 "\n", value);
669     }
670     return 0;
671 }
672 #endif
673 
674 void de_dump_data_element(const uint8_t * record){
675 #ifdef ENABLE_SDP_DES_DUMP
676     int indent = 0;
677     // hack to get root DES, too.
678     de_type_t type = de_get_element_type(record);
679     de_size_t size = de_get_size_type(record);
680     de_traversal_dump_data((uint8_t *) record, type, size, (void*) &indent);
681 #endif
682 }
683 
684 uint8_t* sdp_service_search_pattern_for_uuid16(uint16_t uuid16){
685     big_endian_store_16(des_serviceSearchPattern, 3, uuid16);
686     return (uint8_t*)des_serviceSearchPattern;
687 }
688 
689 uint8_t* sdp_service_search_pattern_for_uuid128(const uint8_t * uuid128){
690     memcpy(&des_serviceSearchPatternUUID128[3], uuid128, 16);
691     return (uint8_t*)des_serviceSearchPatternUUID128;
692 }
693 
694