xref: /btstack/src/ad_parser.c (revision 2fca4dad957cd7b88f4657ed51e89c12615dda72)
1 /*
2  * Copyright (C) 2014 BlueKitchen GmbH
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the copyright holders nor the names of
14  *    contributors may be used to endorse or promote products derived
15  *    from this software without specific prior written permission.
16  * 4. Any redistribution, use, or modification is done solely for
17  *    personal benefit and not for any commercial purpose or for
18  *    monetary gain.
19  *
20  * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL BLUEKITCHEN
24  * GMBH OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
27  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
30  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * Please inquire about commercial licensing options at
34  * [email protected]
35  *
36  */
37 
38 #define BTSTACK_FILE__ "ad_parser.c"
39 
40 
41 // *****************************************************************************
42 //
43 // Advertising Data Parser
44 //
45 // *****************************************************************************
46 
47 #include <stdint.h>
48 #include <string.h>
49 
50 #include "bluetooth_data_types.h"
51 #include "btstack_util.h"
52 #include "hci.h"
53 #include "hci_cmd.h"
54 
55 #include "ad_parser.h"
56 
ad_iterator_init(ad_context_t * context,uint8_t ad_len,const uint8_t * ad_data)57 void ad_iterator_init(ad_context_t *context, uint8_t ad_len, const uint8_t * ad_data){
58     context->data = ad_data;
59     context->length = ad_len;
60     context->offset = 0;
61 }
62 
ad_iterator_has_more(const ad_context_t * context)63 bool ad_iterator_has_more(const ad_context_t * context){
64     // assert chunk_len and chunk_type are withing buffer
65     if ((context->offset + 1u) >= context->length) {
66         return false;
67     }
68 
69     // assert chunk_len > 0
70     uint8_t chunk_len = context->data[context->offset];
71     if (chunk_len == 0u){
72         return false;
73     }
74 
75     // assert complete chunk fits into buffer
76     if ((context->offset + 1u + chunk_len) > context->length) {
77         return false;
78     }
79     return true;
80 }
81 
82 // pre: ad_iterator_has_more() == 1
ad_iterator_next(ad_context_t * context)83 void ad_iterator_next(ad_context_t * context){
84     uint8_t chunk_len = context->data[context->offset];
85     context->offset += 1u + chunk_len;
86 }
87 
ad_iterator_get_data_len(const ad_context_t * context)88 uint8_t   ad_iterator_get_data_len(const ad_context_t * context){
89     return context->data[context->offset] - 1u;
90 }
91 
ad_iterator_get_data_type(const ad_context_t * context)92 uint8_t   ad_iterator_get_data_type(const ad_context_t * context){
93     return context->data[context->offset + 1u];
94 }
95 
ad_iterator_get_data(const ad_context_t * context)96 const uint8_t * ad_iterator_get_data(const ad_context_t * context){
97     return &context->data[context->offset + 2u];
98 }
99 
ad_data_contains_uuid16(uint8_t ad_len,const uint8_t * ad_data,uint16_t uuid16)100 bool ad_data_contains_uuid16(uint8_t ad_len, const uint8_t * ad_data, uint16_t uuid16){
101     ad_context_t context;
102     ad_iterator_init(&context, ad_len, ad_data);
103     while ( ad_iterator_has_more(&context) ){
104         uint8_t data_type    = ad_iterator_get_data_type(&context);
105         uint8_t data_len     = ad_iterator_get_data_len(&context);
106         const uint8_t * data = ad_iterator_get_data(&context);
107 
108         uint8_t i;
109         uint8_t ad_uuid128[16], uuid128_bt[16];
110 
111         switch (data_type){
112             case BLUETOOTH_DATA_TYPE_INCOMPLETE_LIST_OF_16_BIT_SERVICE_CLASS_UUIDS:
113             case BLUETOOTH_DATA_TYPE_COMPLETE_LIST_OF_16_BIT_SERVICE_CLASS_UUIDS:
114                 for (i=0u; (i + 2u) <= data_len; i+= 2u){
115                     uint16_t uuid = (uint16_t) little_endian_read_16(data, (int) i);
116                     if ( uuid == uuid16 ) {
117                         return true;
118                     }
119                 }
120                 break;
121             case BLUETOOTH_DATA_TYPE_INCOMPLETE_LIST_OF_128_BIT_SERVICE_CLASS_UUIDS:
122             case BLUETOOTH_DATA_TYPE_COMPLETE_LIST_OF_128_BIT_SERVICE_CLASS_UUIDS:
123                 uuid_add_bluetooth_prefix(ad_uuid128, uuid16);
124                 reverse_128(ad_uuid128, uuid128_bt);
125                 for (i=0u; (i + 16u) <= data_len; i += 16u){
126                     if (memcmp(uuid128_bt, &data[i], 16) == 0){
127                         return true;
128                     };
129                 }
130                 break;
131             default:
132                 break;
133         }
134         ad_iterator_next(&context);
135     }
136     return false;
137 }
138 
ad_data_contains_uuid128(uint8_t ad_len,const uint8_t * ad_data,const uint8_t * uuid128)139 bool ad_data_contains_uuid128(uint8_t ad_len, const uint8_t * ad_data, const uint8_t * uuid128){
140     ad_context_t context;
141     // input in big endian/network order, bluetooth data in little endian
142     uint8_t uuid128_le[16];
143     reverse_128(uuid128, uuid128_le);
144     ad_iterator_init(&context, ad_len, ad_data);
145     while ( ad_iterator_has_more(&context) ){
146         uint8_t data_type = ad_iterator_get_data_type(&context);
147         uint8_t data_len  = ad_iterator_get_data_len(&context);
148         const uint8_t * data = ad_iterator_get_data(&context);
149 
150         uint8_t i;
151         uint8_t ad_uuid128[16];
152 
153         switch (data_type){
154             case BLUETOOTH_DATA_TYPE_INCOMPLETE_LIST_OF_16_BIT_SERVICE_CLASS_UUIDS:
155             case BLUETOOTH_DATA_TYPE_COMPLETE_LIST_OF_16_BIT_SERVICE_CLASS_UUIDS:
156                 for (i = 0u; (i+2u) <= data_len; i += 2u){
157                     uint16_t uuid16 = little_endian_read_16(data, (int) i);
158                     uuid_add_bluetooth_prefix(ad_uuid128, uuid16);
159 
160                     if (memcmp(ad_uuid128, uuid128_le, 16) == 0) {
161                         return true;
162                     }
163                 }
164 
165                 break;
166             case BLUETOOTH_DATA_TYPE_INCOMPLETE_LIST_OF_128_BIT_SERVICE_CLASS_UUIDS:
167             case BLUETOOTH_DATA_TYPE_COMPLETE_LIST_OF_128_BIT_SERVICE_CLASS_UUIDS:
168                 for (i = 0u; (i + 16u) <= data_len; i += 16u){
169                   if (memcmp(uuid128_le, &data[i], 16) == 0) {
170                       return true;
171                   }
172                 }
173                 break;
174             default:
175                 break;
176         }
177         ad_iterator_next(&context);
178     }
179     return false;
180 }
181 
182