xref: /btstack/src/le-audio/gatt-service/broadcast_audio_scan_service_util.c (revision c824d78c0a34df89b57d535abafcc7dacf30bb06)
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_copy_source_common_data_to_buffer(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_virtual_memcpy_helper(field_data, 1, *source_offset, buffer, buffer_size, buffer_offset);
65     (*source_offset)++;
66 
67     reverse_bd_addr(data->address, &field_data[0]);
68     stored_bytes += le_audio_virtual_memcpy_helper(field_data, 6, *source_offset, buffer, buffer_size, buffer_offset);
69     (*source_offset) += 6;
70 
71     field_data[0] = data->adv_sid;
72     stored_bytes += le_audio_virtual_memcpy_helper(field_data, 1, *source_offset, buffer, buffer_size, buffer_offset);
73     (*source_offset)++;
74 
75     little_endian_store_24(field_data, 0, data->broadcast_id);
76     stored_bytes += le_audio_virtual_memcpy_helper(field_data, 3, *source_offset, buffer, buffer_size, buffer_offset);
77     (*source_offset) += 3;
78 
79     return stored_bytes;
80 }
81 
82 // offset gives position into fully serialized bass record
83 uint16_t
84 bass_util_store_source_subgroups_into_buffer(const bass_source_data_t *data, bool use_state_fields, uint16_t *source_offset,
85                                              uint16_t buffer_offset, uint8_t *buffer, uint16_t buffer_size) {
86     uint16_t stored_bytes = 0;
87     uint8_t  field_data[16];
88 
89     field_data[0] = (uint8_t)data->subgroups_num;
90     stored_bytes += le_audio_virtual_memcpy_helper(field_data, 1, *source_offset, buffer, buffer_size, buffer_offset);
91     (*source_offset)++;
92 
93     uint8_t i;
94     for (i = 0; i < data->subgroups_num; i++){
95         bass_subgroup_t subgroup = data->subgroups[i];
96 
97         if (use_state_fields) {
98             little_endian_store_32(field_data, 0, subgroup.bis_sync_state);
99         } else {
100             little_endian_store_32(field_data, 0, subgroup.bis_sync);
101         }
102         stored_bytes += le_audio_virtual_memcpy_helper(field_data, 4, *source_offset, buffer, buffer_size, buffer_offset);
103         (*source_offset) += 4;
104         stored_bytes += le_audio_virtual_memcpy_metadata(&subgroup.metadata, subgroup.metadata_length, source_offset, buffer, buffer_size, buffer_offset);
105     }
106     return stored_bytes;
107 }
108 
109 bool bass_util_pa_sync_state_and_subgroups_in_valid_range(uint8_t *buffer, uint16_t buffer_size){
110     uint8_t pos = 0;
111     // pa_sync_state
112     uint8_t pa_sync_state = buffer[pos++];
113     if (pa_sync_state >= (uint8_t)LE_AUDIO_PA_SYNC_STATE_RFU){
114         log_info("Unexpected pa_sync_state 0x%02X", pa_sync_state);
115         return false;
116     }
117 
118     // pa_interval
119     pos += 2;
120     uint8_t num_subgroups = buffer[pos++];
121     if (num_subgroups > BASS_SUBGROUPS_MAX_NUM){
122         log_info("Number of subgroups %u exceedes maximum %u", num_subgroups, BASS_SUBGROUPS_MAX_NUM);
123         return false;
124     }
125 
126     // If a BIS_Sync parameter value is not 0xFFFFFFFF for a subgroup,
127     // and if a BIS_index value written by a client is set to a value of 0b1 in more than one subgroup,
128     // the server shall ignore the operation.
129     uint8_t i;
130     uint32_t mask_total = 0;
131     for (i = 0; i < num_subgroups; i++){
132         // bis_sync
133         uint32_t bis_sync = little_endian_read_32(buffer, pos);
134         pos += 4;
135 
136         if (bis_sync != 0xFFFFFFFF){
137             uint32_t mask_add = mask_total + ~bis_sync;
138             uint32_t mask_or  = mask_total | ~bis_sync;
139             if (mask_add != mask_or){
140                 // not disjunct
141                 return false;
142             }
143             mask_total = mask_add;
144         }
145 
146         // check if we can read metadata_length
147         if (pos >= buffer_size){
148             log_info("Metadata length not specified, subgroup %u", i);
149             return false;
150         }
151 
152         uint8_t metadata_length = buffer[pos++];
153 
154         if ((buffer_size - pos) < metadata_length){
155             log_info("Metadata length %u exceedes remaining buffer %u", metadata_length, buffer_size - pos);
156             return false;
157         }
158         // metadata
159         pos += metadata_length;
160     }
161 
162     return (pos == buffer_size);
163 }
164 
165 bool bass_util_add_source_buffer_in_valid_range(uint8_t *buffer, uint16_t buffer_size){
166     if (buffer_size < 15){
167         log_info("Add Source opcode, buffer too small");
168         return false;
169     }
170 
171     uint8_t pos = 0;
172     // addr type
173     uint8_t adv_type = buffer[pos++];
174     if (adv_type > (uint8_t)BD_ADDR_TYPE_LE_RANDOM){
175         log_info("Unexpected adv_type 0x%02X", adv_type);
176         return false;
177     }
178 
179     // address
180     pos += 6;
181 
182     // advertising_sid Range: 0x00-0x0F
183     uint8_t advertising_sid = buffer[pos++];
184     if (advertising_sid > 0x0F){
185         log_info("Advertising sid out of range 0x%02X", advertising_sid);
186         return false;
187     }
188 
189     // broadcast_id
190     pos += 3;
191     return bass_util_pa_sync_state_and_subgroups_in_valid_range(buffer+pos, buffer_size-pos);
192 }
193 
194 void
195 bass_util_get_pa_info_and_subgroups_from_buffer(uint8_t *buffer, uint16_t buffer_size, bass_source_data_t *source_data,
196                                                 bool is_broadcast_receive_state) {
197     UNUSED(buffer_size);
198     uint8_t pos = 0;
199     // for Broadcast Receive state, we have BIG_Encryption + Bad_Code, while for Add/Modify we have PA_Interval
200     if (is_broadcast_receive_state){
201         source_data->pa_sync_state = (le_audio_pa_sync_state_t)buffer[pos++];
202         le_audio_big_encryption_t big_encryption = (le_audio_big_encryption_t) buffer[pos++];
203         if (big_encryption == LE_AUDIO_BIG_ENCRYPTION_BAD_CODE){
204             pos += 16;
205         }
206     } else {
207         source_data->pa_sync       = (le_audio_pa_sync_t)buffer[pos++];
208         source_data->pa_interval = little_endian_read_16(buffer, pos);
209         pos += 2;
210     }
211 
212     source_data->subgroups_num = buffer[pos++];
213     uint8_t i;
214     for (i = 0; i < source_data->subgroups_num; i++){
215         // bis_sync / state
216         if (is_broadcast_receive_state){
217             source_data->subgroups[i].bis_sync_state = little_endian_read_32(buffer, pos);
218         } else {
219             source_data->subgroups[i].bis_sync = little_endian_read_32(buffer, pos);
220         }
221         pos += 4;
222 
223         uint8_t metadata_bytes_read = le_audio_metadata_parse_tlv(&buffer[pos], buffer_size - pos, &source_data->subgroups[i].metadata);
224         source_data->subgroups[i].metadata_length = metadata_bytes_read - 1;
225         pos += metadata_bytes_read;
226     }
227 }
228 
229 void bass_util_get_source_from_buffer(uint8_t *buffer, uint16_t buffer_size, bass_source_data_t *source_data,
230                                       bool is_broadcast_receive_state) {
231     UNUSED(buffer_size);
232     uint8_t pos = 0;
233 
234     source_data->address_type = (bd_addr_type_t)buffer[pos++];
235 
236     reverse_bd_addr(&buffer[pos], source_data->address);
237     pos += 6;
238 
239     source_data->adv_sid = buffer[pos++];
240 
241     source_data->broadcast_id = little_endian_read_24(buffer, pos);
242     pos += 3;
243 
244     bass_util_get_pa_info_and_subgroups_from_buffer(buffer + pos, buffer_size - pos, source_data, is_broadcast_receive_state);
245 }