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__ "att_db_util.c"
39
40 #include <string.h>
41 #include <stdlib.h>
42
43 #include "ble/att_db_util.h"
44 #include "ble/att_db.h"
45 #include "ble/core.h"
46 #include "btstack_util.h"
47 #include "btstack_debug.h"
48 #include "bluetooth.h"
49
50 // ATT DB Storage
51 #ifdef HAVE_MALLOC
52 // number of bytes that the att db buffer is increased on init / realloc
53 #define ATT_DB_BUFFER_INCREMENT 128
54 #else
55 #ifdef MAX_ATT_DB_SIZE
56 static uint8_t att_db_storage[MAX_ATT_DB_SIZE];
57 #else
58 #error Neither HAVE_MALLOC nor MAX_ATT_DB_SIZE is defined.
59 #endif
60 #endif
61
62 static uint8_t * att_db;
63 static uint16_t att_db_size;
64 static uint16_t att_db_max_size;
65 static uint16_t att_db_next_handle;
66 static uint16_t att_db_hash_len;
67
att_db_util_set_end_tag(void)68 static void att_db_util_set_end_tag(void){
69 // end tag
70 att_db[att_db_size] = 0u;
71 att_db[att_db_size+1u] = 0u;
72 }
73
att_db_util_init(void)74 void att_db_util_init(void){
75 #ifdef HAVE_MALLOC
76 if (att_db == NULL){
77 att_db = (uint8_t*) malloc((size_t)ATT_DB_BUFFER_INCREMENT);
78 att_db_max_size = (uint16_t)ATT_DB_BUFFER_INCREMENT;
79 }
80 #else
81 att_db = att_db_storage;
82 att_db_max_size = sizeof(att_db_storage);
83 #endif
84 // store att version
85 att_db[0] = (uint8_t)ATT_DB_VERSION;
86 att_db_size = 1u;
87 att_db_next_handle = 1u;
88 att_db_hash_len = 0u;
89 att_db_util_set_end_tag();
90 }
91
att_db_util_set_next_handle(uint16_t handle)92 void att_db_util_set_next_handle(uint16_t handle){
93 btstack_assert(handle >= att_db_next_handle); // do not reuse assigned handles
94 att_db_next_handle = handle;
95 }
96
att_db_util_hash_include_with_value(uint16_t uuid16)97 static bool att_db_util_hash_include_with_value(uint16_t uuid16){
98 /* «Primary Service», «Secondary Service», «Included Service», «Characteristic», or «Characteristic Extended Properties» */
99 switch (uuid16){
100 case GATT_PRIMARY_SERVICE_UUID:
101 case GATT_SECONDARY_SERVICE_UUID:
102 case GATT_INCLUDE_SERVICE_UUID:
103 case GATT_CHARACTERISTICS_UUID:
104 case GATT_CHARACTERISTIC_EXTENDED_PROPERTIES:
105 return true;
106 default:
107 return false;
108 }
109 }
110
att_db_util_hash_include_without_value(uint16_t uuid16)111 static bool att_db_util_hash_include_without_value(uint16_t uuid16){
112 /* «Characteristic User Description», «Client Characteristic Configuration», «Server Characteristic Configuration»,
113 * «Characteristic Aggregate Format», «Characteristic Format» */
114 switch (uuid16){
115 case GATT_CHARACTERISTIC_USER_DESCRIPTION:
116 case GATT_CLIENT_CHARACTERISTICS_CONFIGURATION:
117 case GATT_SERVER_CHARACTERISTICS_CONFIGURATION:
118 case GATT_CHARACTERISTIC_PRESENTATION_FORMAT:
119 case GATT_CHARACTERISTIC_AGGREGATE_FORMAT:
120 return true;
121 default:
122 return false;
123 }
124 }
125
126 /**
127 * asserts that the requested amount of bytes can be stored in the att_db
128 * @return TRUE if space is available
129 */
att_db_util_assert_space(uint16_t size)130 static int att_db_util_assert_space(uint16_t size){
131 uint16_t required_size = att_db_size + size + 2u;
132 if (required_size <= att_db_max_size) return 1;
133 #ifdef HAVE_MALLOC
134 uint16_t new_size = att_db_max_size;
135 while (new_size < required_size){
136 new_size += (uint16_t)ATT_DB_BUFFER_INCREMENT;
137 }
138 uint8_t * new_db = (uint8_t*) realloc(att_db, new_size);
139 if (!new_db) {
140 log_error("att_db: realloc failed");
141 return 0;
142 }
143 att_db = new_db;
144 att_db_max_size = new_size;
145 att_set_db(att_db); // Update att_db with the new db
146 return 1;
147 #else
148 log_error("att_db: out of memory");
149 return 0;
150 #endif
151 }
152
153 // attribute size in bytes (16), flags(16), handle (16), uuid (16/128), value(...)
154
155 // db endds with 0x00 0x00
156
att_db_util_add_attribute_uuid16(uint16_t uuid16,uint16_t flags,uint8_t * data,uint16_t data_len)157 static void att_db_util_add_attribute_uuid16(uint16_t uuid16, uint16_t flags, uint8_t * data, uint16_t data_len){
158 int size = 2u + 2u + 2u + 2u + data_len;
159 if (!att_db_util_assert_space(size)) return;
160 little_endian_store_16(att_db, att_db_size, size);
161 att_db_size += 2u;
162 little_endian_store_16(att_db, att_db_size, flags);
163 att_db_size += 2u;
164 little_endian_store_16(att_db, att_db_size, att_db_next_handle);
165 att_db_size += 2u;
166 att_db_next_handle++;
167 little_endian_store_16(att_db, att_db_size, uuid16);
168 att_db_size += 2u;
169 (void)memcpy(&att_db[att_db_size], data, data_len);
170 att_db_size += data_len;
171 att_db_util_set_end_tag();
172
173 if (att_db_util_hash_include_with_value(uuid16)){
174 att_db_hash_len += 4u + data_len;
175 } else if (att_db_util_hash_include_without_value(uuid16)){
176 att_db_hash_len += 4u;
177 }
178 }
179
att_db_util_add_attribute_uuid128(const uint8_t * uuid128,uint16_t flags,uint8_t * data,uint16_t data_len)180 static void att_db_util_add_attribute_uuid128(const uint8_t * uuid128, uint16_t flags, uint8_t * data, uint16_t data_len){
181 int size = 2u + 2u + 2u + 16u + data_len;
182 if (!att_db_util_assert_space(size)) return;
183 uint16_t flags_to_store = flags | (uint16_t)ATT_PROPERTY_UUID128;
184 little_endian_store_16(att_db, att_db_size, size);
185 att_db_size += 2u;
186 little_endian_store_16(att_db, att_db_size, flags_to_store);
187 att_db_size += 2u;
188 little_endian_store_16(att_db, att_db_size, att_db_next_handle);
189 att_db_size += 2u;
190 att_db_next_handle++;
191 reverse_128(uuid128, &att_db[att_db_size]);
192 att_db_size += 16u;
193 (void)memcpy(&att_db[att_db_size], data, data_len);
194 att_db_size += data_len;
195 att_db_util_set_end_tag();
196 }
197
att_db_util_add_service_uuid16(uint16_t uuid16)198 uint16_t att_db_util_add_service_uuid16(uint16_t uuid16){
199 uint8_t buffer[2];
200 little_endian_store_16(buffer, 0, uuid16);
201 uint16_t service_handle = att_db_next_handle;
202 att_db_util_add_attribute_uuid16(GATT_PRIMARY_SERVICE_UUID, ATT_PROPERTY_READ, buffer, 2);
203 return service_handle;
204 }
205
att_db_util_add_service_uuid128(const uint8_t * uuid128)206 uint16_t att_db_util_add_service_uuid128(const uint8_t * uuid128){
207 uint8_t buffer[16];
208 reverse_128(uuid128, buffer);
209 uint16_t service_handle = att_db_next_handle;
210 att_db_util_add_attribute_uuid16(GATT_PRIMARY_SERVICE_UUID, ATT_PROPERTY_READ, buffer, 16);
211 return service_handle;
212 }
213
att_db_util_add_secondary_service_uuid16(uint16_t uuid16)214 uint16_t att_db_util_add_secondary_service_uuid16(uint16_t uuid16){
215 uint8_t buffer[2];
216 little_endian_store_16(buffer, 0, uuid16);
217 uint16_t service_handle = att_db_next_handle;
218 att_db_util_add_attribute_uuid16(GATT_SECONDARY_SERVICE_UUID, ATT_PROPERTY_READ, buffer, 2);
219 return service_handle;
220 }
221
att_db_util_add_secondary_service_uuid128(const uint8_t * uuid128)222 uint16_t att_db_util_add_secondary_service_uuid128(const uint8_t * uuid128){
223 uint8_t buffer[16];
224 reverse_128(uuid128, buffer);
225 uint16_t service_handle = att_db_next_handle;
226 att_db_util_add_attribute_uuid16(GATT_SECONDARY_SERVICE_UUID, ATT_PROPERTY_READ, buffer, 16);
227 return service_handle;
228 }
229
att_db_util_add_included_service_uuid16(uint16_t start_group_handle,uint16_t end_group_handle,uint16_t uuid16)230 uint16_t att_db_util_add_included_service_uuid16(uint16_t start_group_handle, uint16_t end_group_handle, uint16_t uuid16){
231 uint8_t buffer[6];
232 little_endian_store_16(buffer, 0, start_group_handle);
233 little_endian_store_16(buffer, 2, end_group_handle);
234 little_endian_store_16(buffer, 4, uuid16);
235 uint16_t service_handle = att_db_next_handle;
236 att_db_util_add_attribute_uuid16(GATT_INCLUDE_SERVICE_UUID, ATT_PROPERTY_READ, buffer, sizeof(buffer));
237 return service_handle;
238 }
239
att_db_util_add_client_characteristic_configuration(uint16_t flags)240 static void att_db_util_add_client_characteristic_configuration(uint16_t flags){
241 uint8_t buffer[2];
242 // drop permission for read (0xc00), keep write permissions (0x0091)
243 uint16_t flags_to_store = (flags & 0x1f391u) | (uint16_t)ATT_PROPERTY_READ | (uint16_t)ATT_PROPERTY_WRITE | (uint16_t)ATT_PROPERTY_DYNAMIC;
244 little_endian_store_16(buffer, 0, 0);
245 att_db_util_add_attribute_uuid16(GATT_CLIENT_CHARACTERISTICS_CONFIGURATION, flags_to_store, buffer, 2);
246 }
247
att_db_util_encode_permissions(uint16_t properties,uint8_t read_permission,uint8_t write_permission)248 static uint16_t att_db_util_encode_permissions(uint16_t properties, uint8_t read_permission, uint8_t write_permission){
249 // drop Broadcast (0x01), Notify (0x10), Indicate (0x20), Extended Attributes (0x80) - not used for flags
250 uint16_t flags = properties & 0xfff4eu;
251 // if encryption requested, set encryption key size to 16
252 if ((read_permission > (uint8_t)ATT_SECURITY_NONE) || (write_permission > (uint8_t)ATT_SECURITY_NONE)){
253 flags |= 0xf000u;
254 }
255 // map SC requirement
256 uint8_t final_read_permission;
257 if (read_permission == (uint8_t)ATT_SECURITY_AUTHENTICATED_SC){
258 final_read_permission = (uint8_t)ATT_SECURITY_AUTHENTICATED;
259 flags |= (uint16_t)ATT_PROPERTY_READ_PERMISSION_SC;
260 } else {
261 final_read_permission = read_permission;
262 }
263 uint8_t final_write_permission;
264 if (write_permission == (uint8_t)ATT_SECURITY_AUTHENTICATED_SC){
265 final_write_permission = (uint8_t)ATT_SECURITY_AUTHENTICATED;
266 flags |= (uint16_t)ATT_PROPERTY_WRITE_PERMISSION_SC;
267 } else {
268 final_write_permission = write_permission;
269 }
270 // encode read/write security levels
271 if ((final_read_permission & 1u) != 0u){
272 flags |= (uint16_t)ATT_PROPERTY_READ_PERMISSION_BIT_0;
273 }
274 if ((final_read_permission & 2u) != 0u){
275 flags |= (uint16_t)ATT_PROPERTY_READ_PERMISSION_BIT_1;
276 }
277 if ((final_write_permission & 1u) != 0u){
278 flags |= (uint16_t)ATT_PROPERTY_WRITE_PERMISSION_BIT_0;
279 }
280 if ((final_write_permission & 2u) != 0u){
281 flags |= (uint16_t)ATT_PROPERTY_WRITE_PERMISSION_BIT_1;
282 }
283 return flags;
284 }
285
att_db_util_add_characteristic_uuid16(uint16_t uuid16,uint16_t properties,uint8_t read_permission,uint8_t write_permission,uint8_t * data,uint16_t data_len)286 uint16_t att_db_util_add_characteristic_uuid16(uint16_t uuid16, uint16_t properties, uint8_t read_permission, uint8_t write_permission, uint8_t * data, uint16_t data_len){
287 uint8_t buffer[5];
288 buffer[0] = (uint8_t) (properties & 0xff);
289 little_endian_store_16(buffer, 1u, att_db_next_handle + 1u);
290 little_endian_store_16(buffer, 3, uuid16);
291 att_db_util_add_attribute_uuid16(GATT_CHARACTERISTICS_UUID, ATT_PROPERTY_READ, buffer, sizeof(buffer));
292 uint16_t flags = att_db_util_encode_permissions(properties, read_permission, write_permission);
293 uint16_t value_handle = att_db_next_handle;
294 att_db_util_add_attribute_uuid16(uuid16, flags, data, data_len);
295 if ((properties & (uint8_t)(ATT_PROPERTY_NOTIFY | ATT_PROPERTY_INDICATE)) != 0u){
296 att_db_util_add_client_characteristic_configuration(flags);
297 }
298 return value_handle;
299 }
300
att_db_util_add_characteristic_uuid128(const uint8_t * uuid128,uint16_t properties,uint8_t read_permission,uint8_t write_permission,uint8_t * data,uint16_t data_len)301 uint16_t att_db_util_add_characteristic_uuid128(const uint8_t * uuid128, uint16_t properties, uint8_t read_permission, uint8_t write_permission, uint8_t * data, uint16_t data_len){
302 uint8_t buffer[19];
303 buffer[0] = (uint8_t) (properties & 0xff);
304 little_endian_store_16(buffer, 1u, att_db_next_handle + 1u);
305 reverse_128(uuid128, &buffer[3]);
306 att_db_util_add_attribute_uuid16(GATT_CHARACTERISTICS_UUID, ATT_PROPERTY_READ, buffer, sizeof(buffer));
307 uint16_t flags = att_db_util_encode_permissions(properties, read_permission, write_permission);
308 uint16_t value_handle = att_db_next_handle;
309 att_db_util_add_attribute_uuid128(uuid128, flags, data, data_len);
310 if ((properties & (uint8_t)(ATT_PROPERTY_NOTIFY | ATT_PROPERTY_INDICATE)) != 0u){
311 att_db_util_add_client_characteristic_configuration(flags);
312 }
313 return value_handle;
314 }
315
att_db_util_add_descriptor_uuid16(uint16_t uuid16,uint16_t properties,uint8_t read_permission,uint8_t write_permission,uint8_t * data,uint16_t data_len)316 uint16_t att_db_util_add_descriptor_uuid16(uint16_t uuid16, uint16_t properties, uint8_t read_permission, uint8_t write_permission, uint8_t * data, uint16_t data_len){
317 uint16_t descriptor_handler = att_db_next_handle;
318 uint16_t flags = att_db_util_encode_permissions(properties, read_permission, write_permission);
319 att_db_util_add_attribute_uuid16(uuid16, flags, data, data_len);
320 return descriptor_handler;
321 }
322
att_db_util_add_descriptor_uuid128(const uint8_t * uuid128,uint16_t properties,uint8_t read_permission,uint8_t write_permission,uint8_t * data,uint16_t data_len)323 uint16_t att_db_util_add_descriptor_uuid128(const uint8_t * uuid128, uint16_t properties, uint8_t read_permission, uint8_t write_permission, uint8_t * data, uint16_t data_len){
324 uint16_t descriptor_handler = att_db_next_handle;
325 uint16_t flags = att_db_util_encode_permissions(properties, read_permission, write_permission);
326 att_db_util_add_attribute_uuid128(uuid128, flags, data, data_len);
327 return descriptor_handler;
328 }
329
att_db_util_get_address(void)330 uint8_t * att_db_util_get_address(void){
331 return att_db;
332 }
333
att_db_util_get_size(void)334 uint16_t att_db_util_get_size(void){
335 return att_db_size + 2u; // end tag
336 }
337
338 static uint8_t * att_db_util_hash_att_ptr;
339 static uint16_t att_db_util_hash_offset;
340 static uint16_t att_db_util_hash_bytes_available;
341
att_db_util_hash_fetch_next_attribute(void)342 static void att_db_util_hash_fetch_next_attribute(void){
343 while (true){
344 uint16_t size = little_endian_read_16(att_db_util_hash_att_ptr, 0);
345 btstack_assert(size != 0);
346 UNUSED(size);
347 uint16_t flags = little_endian_read_16(att_db_util_hash_att_ptr, 2);
348 if ((flags & (uint16_t)ATT_PROPERTY_UUID128) == 0u) {
349 uint16_t uuid16 = little_endian_read_16(att_db_util_hash_att_ptr, 6);
350 if (att_db_util_hash_include_with_value(uuid16)){
351 att_db_util_hash_offset = 4;
352 att_db_util_hash_bytes_available = size - 4u;
353 return;
354 } else if (att_db_util_hash_include_without_value(uuid16)){
355 att_db_util_hash_offset = 4;
356 att_db_util_hash_bytes_available = 4;
357 return;
358 }
359 }
360 att_db_util_hash_att_ptr += size;
361 }
362 }
363
att_db_util_hash_len(void)364 uint16_t att_db_util_hash_len(void){
365 return att_db_hash_len;
366 }
367
att_db_util_hash_init(void)368 void att_db_util_hash_init(void){
369 // skip version info
370 att_db_util_hash_att_ptr = &att_db[1];
371 att_db_util_hash_bytes_available = 0u;
372 }
373
att_db_util_hash_get_next(void)374 uint8_t att_db_util_hash_get_next(void){
375 // find next hashable data blob
376 if (att_db_util_hash_bytes_available == 0u){
377 att_db_util_hash_fetch_next_attribute();
378 }
379
380 // get next byte
381 uint8_t next = att_db_util_hash_att_ptr[att_db_util_hash_offset++];
382 att_db_util_hash_bytes_available--;
383
384 // go to next attribute if blob used up
385 if (att_db_util_hash_bytes_available == 0u){
386 uint16_t size = little_endian_read_16(att_db_util_hash_att_ptr, 0);
387 att_db_util_hash_att_ptr += size;
388 }
389 return next;
390 }
391
att_db_util_hash_get(uint16_t offset)392 static uint8_t att_db_util_hash_get(uint16_t offset){
393 UNUSED(offset);
394 return att_db_util_hash_get_next();
395 }
396
att_db_util_hash_calc(btstack_crypto_aes128_cmac_t * request,uint8_t * db_hash,void (* callback)(void * arg),void * callback_arg)397 void att_db_util_hash_calc(btstack_crypto_aes128_cmac_t * request, uint8_t * db_hash, void (* callback)(void * arg), void * callback_arg){
398 static const uint8_t zero_key[16] = { 0 };
399 att_db_util_hash_init();
400 btstack_crypto_aes128_cmac_generator(request, zero_key, att_db_hash_len, &att_db_util_hash_get, db_hash, callback, callback_arg);
401 }
402