xref: /btstack/src/btstack_util.h (revision e3ba22907f903f11cd12321c31e7936b8dd1157e)
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 /**
39  * @title General Utility Functions
40  *
41  */
42 
43 #ifndef BTSTACK_UTIL_H
44 #define BTSTACK_UTIL_H
45 
46 
47 #if defined __cplusplus
48 extern "C" {
49 #endif
50 
51 #include <stdint.h>
52 #include <string.h>
53 
54 #include "bluetooth.h"
55 #include "btstack_defines.h"
56 #include "btstack_linked_list.h"
57 
58 // hack: compilation with the android ndk causes an error as there's a reverse_64 macro
59 #ifdef reverse_64
60 #undef reverse_64
61 #endif
62 
63 // will be moved to daemon/btstack_device_name_db.h
64 
65 
66 /**
67  * @brief The device name type
68  */
69 #define DEVICE_NAME_LEN 248
70 typedef uint8_t device_name_t[DEVICE_NAME_LEN+1];
71 
72 /* API_START */
73 
74 /**
75  * @brief Minimum function for uint32_t
76  * @param a
77  * @param b
78  * @return value
79  */
80 uint32_t btstack_min(uint32_t a, uint32_t b);
81 
82 /**
83  * @brief Maximum function for uint32_t
84  * @param a
85  * @param b
86  * @return value
87  */
88 uint32_t btstack_max(uint32_t a, uint32_t b);
89 
90 /**
91  * @brief Calculate delta between two uint32_t points in time
92  * @return time_a - time_b - result > 0 if time_a is newer than time_b
93  */
94 int32_t btstack_time_delta(uint32_t time_a, uint32_t time_b);
95 
96 /**
97  * @brief Calculate delta between two uint16_t points in time
98  * @return time_a - time_b - result > 0 if time_a is newer than time_b
99  */
100 int16_t btstack_time16_delta(uint16_t time_a, uint16_t time_b);
101 
102 /**
103  * @brief Read 16/24/32 bit little endian value from buffer
104  * @param buffer
105  * @param position in buffer
106  * @return value
107  */
108 uint16_t little_endian_read_16(const uint8_t * buffer, int position);
109 uint32_t little_endian_read_24(const uint8_t * buffer, int position);
110 uint32_t little_endian_read_32(const uint8_t * buffer, int position);
111 
112 /**
113  * @brief Write 16/32 bit little endian value into buffer
114  * @param buffer
115  * @param position in buffer
116  * @param value
117  */
118 void little_endian_store_16(uint8_t * buffer, uint16_t position, uint16_t value);
119 void little_endian_store_24(uint8_t * buffer, uint16_t position, uint32_t value);
120 void little_endian_store_32(uint8_t * buffer, uint16_t position, uint32_t value);
121 
122 /**
123  * @brief Read 16/24/32 bit big endian value from buffer
124  * @param buffer
125  * @param position in buffer
126  * @return value
127  */
128 uint32_t big_endian_read_16(const uint8_t * buffer, int position);
129 uint32_t big_endian_read_24(const uint8_t * buffer, int position);
130 uint32_t big_endian_read_32(const uint8_t * buffer, int position);
131 
132 /**
133  * @brief Write 16/32 bit big endian value into buffer
134  * @param buffer
135  * @param position in buffer
136  * @param value
137  */
138 void big_endian_store_16(uint8_t * buffer, uint16_t position, uint16_t value);
139 void big_endian_store_24(uint8_t * buffer, uint16_t position, uint32_t value);
140 void big_endian_store_32(uint8_t * buffer, uint16_t position, uint32_t value);
141 
142 
143 /**
144  * @brief Swap bytes in 16 bit integer
145  */
146 static inline uint16_t btstack_flip_16(uint16_t value){
147     return (uint16_t)((value & 0xffu) << 8) | (value >> 8);
148 }
149 
150 /**
151  * @brief Check for big endian system
152  * @return 1 if on big endian
153  */
154 static inline int btstack_is_big_endian(void){
155 	uint16_t sample = 0x0100;
156 	return (int) *(uint8_t*) &sample;
157 }
158 
159 /**
160  * @brief Check for little endian system
161  * @return 1 if on little endian
162  */
163 static inline int btstack_is_little_endian(void){
164 	uint16_t sample = 0x0001;
165 	return (int) *(uint8_t*) &sample;
166 }
167 
168 /**
169  * @brief Copy from source to destination and reverse byte order
170  * @param src
171  * @param dest
172  * @param len
173  */
174 void reverse_bytes(const uint8_t * src, uint8_t * dest, int len);
175 
176 /**
177  * @brief Wrapper around reverse_bytes for common buffer sizes
178  * @param src
179  * @param dest
180  */
181 void reverse_24 (const uint8_t * src, uint8_t * dest);
182 void reverse_48 (const uint8_t * src, uint8_t * dest);
183 void reverse_56 (const uint8_t * src, uint8_t * dest);
184 void reverse_64 (const uint8_t * src, uint8_t * dest);
185 void reverse_128(const uint8_t * src, uint8_t * dest);
186 void reverse_256(const uint8_t * src, uint8_t * dest);
187 
188 void reverse_bd_addr(const bd_addr_t src, bd_addr_t dest);
189 
190 /**
191  * @brief Check if all bytes in buffer are zero
192  * @param buffer
193  * @param size
194  * @return true if all bytes is buffer are zero
195  */
196 bool btstack_is_null(const uint8_t * buffer, uint16_t size);
197 
198 /**
199  * @brief ASCII character for 4-bit nibble
200  * @return character
201  */
202 char char_for_nibble(int nibble);
203 
204 /**
205  * @brif 4-bit nibble from ASCII character
206  * @return value
207  */
208 int nibble_for_char(char c);
209 
210 /**
211  * @brief Compare two Bluetooth addresses
212  * @param a
213  * @param b
214  * @return 0 if equal
215  */
216 int bd_addr_cmp(const bd_addr_t a, const bd_addr_t b);
217 
218 /**
219  * @brief Copy Bluetooth address
220  * @param dest
221  * @param src
222  */
223 void bd_addr_copy(bd_addr_t dest, const bd_addr_t src);
224 
225 /**
226  * @brief Use printf to write hexdump as single line of data
227  */
228 void printf_hexdump(const void * data, int size);
229 
230 /**
231  * @brief Create human readable representation for UUID128
232  * @note uses fixed global buffer
233  * @return pointer to UUID128 string
234  */
235 char * uuid128_to_str(const uint8_t * uuid);
236 
237 /**
238  * @brief Create human readable represenationt of Bluetooth address
239  * @note uses fixed global buffer
240  * @param delimiter
241  * @return pointer to Bluetooth address string
242  */
243 char * bd_addr_to_str_with_delimiter(const bd_addr_t addr, char delimiter);
244 
245 /**
246  * @brief Create human readable represenationt of Bluetooth address
247  * @note uses fixed global buffer
248  * @return pointer to Bluetooth address string
249  */
250 char * bd_addr_to_str(const bd_addr_t addr);
251 
252 /**
253  * @brief Replace address placeholder '00:00:00:00:00:00' with Bluetooth address
254  * @param buffer
255  * @param size
256  * @param address
257  */
258 void btstack_replace_bd_addr_placeholder(uint8_t * buffer, uint16_t size, const bd_addr_t address);
259 
260 /**
261  * @brief Parse Bluetooth address
262  * @param address_string
263  * @param buffer for parsed address
264  * @return 1 if string was parsed successfully
265  */
266 int sscanf_bd_addr(const char * addr_string, bd_addr_t addr);
267 
268 /**
269  * @brief Constructs UUID128 from 16 or 32 bit UUID using Bluetooth base UUID
270  * @param uuid128 output buffer
271  * @param short_uuid
272  */
273 void uuid_add_bluetooth_prefix(uint8_t * uuid128, uint32_t short_uuid);
274 
275 /**
276  * @brief Checks if UUID128 has Bluetooth base UUID prefix
277  * @param uui128 to test
278  * @return 1 if it can be expressed as UUID32
279  */
280 int  uuid_has_bluetooth_prefix(const uint8_t * uuid128);
281 
282 /**
283  * @brief Parse unsigned number
284  * @param str to parse
285  * @return value
286  */
287 uint32_t btstack_atoi(const char * str);
288 
289 /**
290  * @brief Return number of digits of a uint32 number
291  * @param uint32_number
292  * @return num_digits
293  */
294 int string_len_for_uint32(uint32_t i);
295 
296 /**
297  * @brief Return number of set bits in a uint32 number
298  * @param uint32_number
299  * @return num_set_bits
300  */
301 int count_set_bits_uint32(uint32_t x);
302 
303 /**
304  * @brief Check CRC8 using ETSI TS 101 369 V6.3.0.
305  * @note Only used by RFCOMM
306  * @param data
307  * @param len
308  * @param check_sum
309  */
310 uint8_t btstack_crc8_check(uint8_t * data, uint16_t len, uint8_t check_sum);
311 
312 /**
313  * @brief Calculate CRC8 using ETSI TS 101 369 V6.3.0.
314  * @note Only used by RFCOMM
315  * @param data
316  * @param len
317  */
318 uint8_t btstack_crc8_calc(uint8_t * data, uint16_t len);
319 
320 /**
321  * @brief Get next cid
322  * @param current_cid
323  * @return next cid skiping 0
324  */
325 uint16_t btstack_next_cid_ignoring_zero(uint16_t current_cid);
326 
327 /**
328  * @brief Copy string (up to dst_size-1 characters) from src into dst buffer with terminating '\0'
329  * @note replaces strncpy + dst[dst_size-1] = '\0'
330  * @param dst
331  * @param dst_size
332  * @param src
333  * @retun bytes_copied including trailing 0
334  */
335 uint16_t btstack_strcpy(char * dst, uint16_t dst_size, const char * src);
336 
337 /**
338  * @brief Append src string to string in dst buffer with terminating '\0'
339  * @note max total string length will be dst_size-1 characters
340  * @param dst
341  * @param dst_size
342  * @param src
343  */
344 void btstack_strcat(char * dst, uint16_t dst_size, const char * src);
345 
346 /**
347  * Returns the number of leading 0-bits in x, starting at the most significant bit position.
348  * If x is 0, the result is undefined.
349  * @note maps to __builtin_clz for gcc and clang
350  * @param value
351  * @return number of leading 0-bits
352  */
353 uint8_t btstack_clz(uint32_t value);
354 
355 /**
356  * @brief Copy chunk of data into a virtual buffer backed by a physical buffer.
357  * Used to provide chunk of data of larger buffer that is constructed on the fly, e.g. serializing data struct
358  *
359  * For example, copy field2 to buffer, with buffer_offset = 11
360  *
361  *           field1  field2  field3     field4        field5  filed6
362  * struct:  -------|-------|----------|-------------|-------|--------------
363  * buffer:             ------------------
364  * result:             ----|
365  *
366  * When also copying field3 and field4 to buffer, with buffer_offset = 11
367  *
368  *           field1  field2  field3     field4        field5  filed6
369  * struct:  -------|-------|----------|-------------|-------|--------------
370  * buffer:             ------------------
371  * result:             ----|----------|--
372  *
373  * @param field_data
374  * @param field_len
375  * @param field_offset  position of field in complete data block
376  * @param buffer_data
377  * @param buffer_len
378  * @param buffer_offset position of buffer in complete data block
379  * @return bytes_copied number of bytes actually stored in buffer
380  */
381 uint16_t btstack_virtual_memcpy(
382     const uint8_t * field_data, uint16_t field_len, uint16_t field_offset,
383     uint8_t * buffer, uint16_t buffer_size, uint16_t buffer_offset);
384 
385 
386 /* API_END */
387 
388 #if defined __cplusplus
389 }
390 #endif
391 
392 #endif // BTSTACK_UTIL_H
393