xref: /btstack/src/le-audio/gatt-service/broadcast_audio_scan_service_util.c (revision ced70f9bfeafe291ec597a3a9cc862e39e0da3ce)
1 /*
2  * Copyright (C) 2022 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__ "broadcast_audio_scan_service_server.c"
39 
40 #include <stdio.h>
41 
42 #include "ble/att_db.h"
43 #include "ble/att_server.h"
44 #include "bluetooth_gatt.h"
45 #include "btstack_debug.h"
46 #include "btstack_defines.h"
47 #include "btstack_event.h"
48 #include "btstack_util.h"
49 
50 #include "le-audio/gatt-service/broadcast_audio_scan_service_util.h"
51 #include "le-audio/le_audio.h"
52 #include "le-audio/le_audio_util.h"
53 
54 #ifdef ENABLE_TESTING_SUPPORT
55 #include <stdio.h>
56 #endif
57 
58 // offset gives position into fully serialized bass record
59 uint16_t bass_util_source_data_header_virtual_memcpy(const bass_source_data_t * data, uint16_t *source_offset, uint16_t buffer_offset, uint8_t * buffer, uint16_t buffer_size){
60     uint16_t stored_bytes = 0;
61     uint8_t  field_data[16];
62 
63     field_data[0] = (uint8_t)data->address_type;
64     stored_bytes += le_audio_util_virtual_memcpy_helper(field_data, 1, *source_offset, buffer, buffer_size,
65                                                         buffer_offset);
66     (*source_offset)++;
67 
68     reverse_bd_addr(data->address, &field_data[0]);
69     stored_bytes += le_audio_util_virtual_memcpy_helper(field_data, 6, *source_offset, buffer, buffer_size,
70                                                         buffer_offset);
71     (*source_offset) += 6;
72 
73     field_data[0] = data->adv_sid;
74     stored_bytes += le_audio_util_virtual_memcpy_helper(field_data, 1, *source_offset, buffer, buffer_size,
75                                                         buffer_offset);
76     (*source_offset)++;
77 
78     little_endian_store_24(field_data, 0, data->broadcast_id);
79     stored_bytes += le_audio_util_virtual_memcpy_helper(field_data, 3, *source_offset, buffer, buffer_size,
80                                                         buffer_offset);
81     (*source_offset) += 3;
82 
83     return stored_bytes;
84 }
85 
86 // offset gives position into fully serialized bass record
87 uint16_t
88 bass_util_source_data_subgroups_virtual_memcpy(const bass_source_data_t *data, bool use_state_fields, uint16_t *source_offset,
89                                                uint16_t buffer_offset, uint8_t *buffer, uint16_t buffer_size) {
90     uint16_t stored_bytes = 0;
91     uint8_t  field_data[16];
92 
93     field_data[0] = (uint8_t)data->subgroups_num;
94     stored_bytes += le_audio_util_virtual_memcpy_helper(field_data, 1, *source_offset, buffer, buffer_size,
95                                                         buffer_offset);
96     (*source_offset)++;
97 
98     uint8_t i;
99     for (i = 0; i < data->subgroups_num; i++){
100         bass_subgroup_t subgroup = data->subgroups[i];
101 
102         if (use_state_fields) {
103             little_endian_store_32(field_data, 0, subgroup.bis_sync_state);
104         } else {
105             little_endian_store_32(field_data, 0, subgroup.bis_sync);
106         }
107         stored_bytes += le_audio_util_virtual_memcpy_helper(field_data, 4, *source_offset, buffer, buffer_size,
108                                                             buffer_offset);
109         (*source_offset) += 4;
110         stored_bytes += le_audio_util_metadata_virtual_memcpy(&subgroup.metadata, subgroup.metadata_length,
111                                                               source_offset, buffer, buffer_size, buffer_offset);
112     }
113     return stored_bytes;
114 }
115 
116 bool bass_util_pa_sync_state_and_subgroups_in_valid_range(const uint8_t *buffer, uint16_t buffer_size){
117     uint8_t pos = 0;
118     // pa_sync_state
119     uint8_t pa_sync_state = buffer[pos++];
120     if (pa_sync_state >= (uint8_t)LE_AUDIO_PA_SYNC_STATE_RFU){
121         log_info("Unexpected pa_sync_state 0x%02X", pa_sync_state);
122         return false;
123     }
124 
125     // pa_interval
126     pos += 2;
127     uint8_t num_subgroups = buffer[pos++];
128     if (num_subgroups > BASS_SUBGROUPS_MAX_NUM){
129         log_info("Number of subgroups %u exceedes maximum %u", num_subgroups, BASS_SUBGROUPS_MAX_NUM);
130         return false;
131     }
132 
133     // If a BIS_Sync parameter value is not 0xFFFFFFFF for a subgroup,
134     // and if a BIS_index value written by a client is set to a value of 0b1 in more than one subgroup,
135     // the server shall ignore the operation.
136     uint8_t i;
137     uint32_t mask_total = 0;
138     for (i = 0; i < num_subgroups; i++){
139         // bis_sync
140         uint32_t bis_sync = little_endian_read_32(buffer, pos);
141         pos += 4;
142 
143         if (bis_sync != 0xFFFFFFFF){
144             uint32_t mask_add = mask_total + ~bis_sync;
145             uint32_t mask_or  = mask_total | ~bis_sync;
146             if (mask_add != mask_or){
147                 // not disjunct
148                 return false;
149             }
150             mask_total = mask_add;
151         }
152 
153         // check if we can read metadata_length
154         if (pos >= buffer_size){
155             log_info("Metadata length not specified, subgroup %u", i);
156             return false;
157         }
158 
159         uint8_t metadata_length = buffer[pos++];
160 
161         if ((buffer_size - pos) < metadata_length){
162             log_info("Metadata length %u exceedes remaining buffer %u", metadata_length, buffer_size - pos);
163             return false;
164         }
165         // metadata
166         pos += metadata_length;
167     }
168 
169     return (pos == buffer_size);
170 }
171 
172 bool bass_util_source_buffer_in_valid_range(const uint8_t *buffer, uint16_t buffer_size){
173     if (buffer_size < 15){
174         log_info("Add Source opcode, buffer too small");
175         return false;
176     }
177 
178     uint8_t pos = 0;
179     // addr type
180     uint8_t adv_type = buffer[pos++];
181     if (adv_type > (uint8_t)BD_ADDR_TYPE_LE_RANDOM){
182         log_info("Unexpected adv_type 0x%02X", adv_type);
183         return false;
184     }
185 
186     // address
187     pos += 6;
188 
189     // advertising_sid Range: 0x00-0x0F
190     uint8_t advertising_sid = buffer[pos++];
191     if (advertising_sid > 0x0F){
192         log_info("Advertising sid out of range 0x%02X", advertising_sid);
193         return false;
194     }
195 
196     // broadcast_id
197     pos += 3;
198     return bass_util_pa_sync_state_and_subgroups_in_valid_range(buffer+pos, buffer_size-pos);
199 }
200 
201 void
202 bass_util_pa_info_and_subgroups_parse(const uint8_t *buffer, uint16_t buffer_size, bass_source_data_t *source_data,
203                                       bool is_broadcast_receive_state) {
204     UNUSED(buffer_size);
205     uint8_t pos = 0;
206     // for Broadcast Receive state, we have BIG_Encryption + Bad_Code, while for Add/Modify we have PA_Interval
207     if (is_broadcast_receive_state){
208         source_data->pa_sync_state = (le_audio_pa_sync_state_t)buffer[pos++];
209         le_audio_big_encryption_t big_encryption = (le_audio_big_encryption_t) buffer[pos++];
210         if (big_encryption == LE_AUDIO_BIG_ENCRYPTION_BAD_CODE){
211             pos += 16;
212         }
213     } else {
214         source_data->pa_sync       = (le_audio_pa_sync_t)buffer[pos++];
215         source_data->pa_interval = little_endian_read_16(buffer, pos);
216         pos += 2;
217     }
218 
219     source_data->subgroups_num = buffer[pos++];
220     uint8_t i;
221     for (i = 0; i < source_data->subgroups_num; i++){
222         // bis_sync / state
223         if (is_broadcast_receive_state){
224             source_data->subgroups[i].bis_sync_state = little_endian_read_32(buffer, pos);
225         } else {
226             source_data->subgroups[i].bis_sync = little_endian_read_32(buffer, pos);
227         }
228         pos += 4;
229 
230         uint8_t metadata_bytes_read = le_audio_util_metadata_parse(&buffer[pos], buffer_size - pos,
231                                                                    &source_data->subgroups[i].metadata);
232         source_data->subgroups[i].metadata_length = metadata_bytes_read - 1;
233         pos += metadata_bytes_read;
234     }
235 }
236 
237 void bass_util_source_data_parse(const uint8_t *buffer, uint16_t buffer_size, bass_source_data_t *source_data,
238                                  bool is_broadcast_receive_state) {
239     UNUSED(buffer_size);
240     uint8_t pos = 0;
241 
242     source_data->address_type = (bd_addr_type_t)buffer[pos++];
243 
244     reverse_bd_addr(&buffer[pos], source_data->address);
245     pos += 6;
246 
247     source_data->adv_sid = buffer[pos++];
248 
249     source_data->broadcast_id = little_endian_read_24(buffer, pos);
250     pos += 3;
251 
252     bass_util_pa_info_and_subgroups_parse(buffer + pos, buffer_size - pos, source_data, is_broadcast_receive_state);
253 }