xref: /btstack/src/btstack_util.h (revision 42c5c5581b83a00e2c1de42e4fe687a30b9efa5a)
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 ASCII character for 4-bit nibble
192  * @return character
193  */
194 char char_for_nibble(int nibble);
195 
196 /**
197  * @brif 4-bit nibble from ASCII character
198  * @return value
199  */
200 int nibble_for_char(char c);
201 
202 /**
203  * @brief Compare two Bluetooth addresses
204  * @param a
205  * @param b
206  * @return 0 if equal
207  */
208 int bd_addr_cmp(const bd_addr_t a, const bd_addr_t b);
209 
210 /**
211  * @brief Copy Bluetooth address
212  * @param dest
213  * @param src
214  */
215 void bd_addr_copy(bd_addr_t dest, const bd_addr_t src);
216 
217 /**
218  * @brief Use printf to write hexdump as single line of data
219  */
220 void printf_hexdump(const void * data, int size);
221 
222 /**
223  * @brief Create human readable representation for UUID128
224  * @note uses fixed global buffer
225  * @return pointer to UUID128 string
226  */
227 char * uuid128_to_str(const uint8_t * uuid);
228 
229 /**
230  * @brief Create human readable represenationt of Bluetooth address
231  * @note uses fixed global buffer
232  * @param delimiter
233  * @return pointer to Bluetooth address string
234  */
235 char * bd_addr_to_str_with_delimiter(const bd_addr_t addr, char delimiter);
236 
237 /**
238  * @brief Create human readable represenationt of Bluetooth address
239  * @note uses fixed global buffer
240  * @return pointer to Bluetooth address string
241  */
242 char * bd_addr_to_str(const bd_addr_t addr);
243 
244 /**
245  * @brief Replace address placeholder '00:00:00:00:00:00' with Bluetooth address
246  * @param buffer
247  * @param size
248  * @param address
249  */
250 void btstack_replace_bd_addr_placeholder(uint8_t * buffer, uint16_t size, const bd_addr_t address);
251 
252 /**
253  * @brief Parse Bluetooth address
254  * @param address_string
255  * @param buffer for parsed address
256  * @return 1 if string was parsed successfully
257  */
258 int sscanf_bd_addr(const char * addr_string, bd_addr_t addr);
259 
260 /**
261  * @brief Constructs UUID128 from 16 or 32 bit UUID using Bluetooth base UUID
262  * @param uuid128 output buffer
263  * @param short_uuid
264  */
265 void uuid_add_bluetooth_prefix(uint8_t * uuid128, uint32_t short_uuid);
266 
267 /**
268  * @brief Checks if UUID128 has Bluetooth base UUID prefix
269  * @param uui128 to test
270  * @return 1 if it can be expressed as UUID32
271  */
272 int  uuid_has_bluetooth_prefix(const uint8_t * uuid128);
273 
274 /**
275  * @brief Parse unsigned number
276  * @param str to parse
277  * @return value
278  */
279 uint32_t btstack_atoi(const char * str);
280 
281 /**
282  * @brief Return number of digits of a uint32 number
283  * @param uint32_number
284  * @return num_digits
285  */
286 int string_len_for_uint32(uint32_t i);
287 
288 /**
289  * @brief Return number of set bits in a uint32 number
290  * @param uint32_number
291  * @return num_set_bits
292  */
293 int count_set_bits_uint32(uint32_t x);
294 
295 /**
296  * @brief Check CRC8 using ETSI TS 101 369 V6.3.0.
297  * @note Only used by RFCOMM
298  * @param data
299  * @param len
300  * @param check_sum
301  */
302 uint8_t btstack_crc8_check(uint8_t * data, uint16_t len, uint8_t check_sum);
303 
304 /**
305  * @brief Calculate CRC8 using ETSI TS 101 369 V6.3.0.
306  * @note Only used by RFCOMM
307  * @param data
308  * @param len
309  */
310 uint8_t btstack_crc8_calc(uint8_t * data, uint16_t len);
311 
312 /**
313  * @brief Get next cid
314  * @param current_cid
315  * @return next cid skiping 0
316  */
317 uint16_t btstack_next_cid_ignoring_zero(uint16_t current_cid);
318 
319 /**
320  * @brief Copy string (up to dst_size-1 characters) from src into dst buffer with terminating '\0'
321  * @note replaces strncpy + dst[dst_size-1] = '\0'
322  * @param dst
323  * @param dst_size
324  * @param src
325  * @retun bytes_copied including trailing 0
326  */
327 uint16_t btstack_strcpy(char * dst, uint16_t dst_size, const char * src);
328 
329 /**
330  * @brief Append src string to string in dst buffer with terminating '\0'
331  * @note max total string length will be dst_size-1 characters
332  * @param dst
333  * @param dst_size
334  * @param src
335  */
336 void btstack_strcat(char * dst, uint16_t dst_size, const char * src);
337 
338 /**
339  * Returns the number of leading 0-bits in x, starting at the most significant bit position.
340  * If x is 0, the result is undefined.
341  * @note maps to __builtin_clz for gcc and clang
342  * @param value
343  * @return number of leading 0-bits
344  */
345 uint8_t btstack_clz(uint32_t value);
346 
347 /**
348  * @brief Copy chunk of data into a virtual buffer backed by a physical buffer.
349  * Used to provide chunk of data of larger buffer that is constructed on the fly, e.g. serializing data struct
350  *
351  * For example, copy field2 to buffer, with buffer_offset = 11
352  *
353  *           field1  field2  field3     field4        field5  filed6
354  * struct:  -------|-------|----------|-------------|-------|--------------
355  * buffer:             ------------------
356  * result:             ----|
357  *
358  * When also copying field3 and field4 to buffer, with buffer_offset = 11
359  *
360  *           field1  field2  field3     field4        field5  filed6
361  * struct:  -------|-------|----------|-------------|-------|--------------
362  * buffer:             ------------------
363  * result:             ----|----------|--
364  *
365  * @param field_data
366  * @param field_len
367  * @param field_offset  position of field in complete data block
368  * @param buffer_data
369  * @param buffer_len
370  * @param buffer_offset position of buffer in complete data block
371  * @return bytes_copied number of bytes actually stored in buffer
372  */
373 uint16_t btstack_virtual_memcpy(
374     const uint8_t * field_data, uint16_t field_len, uint16_t field_offset,
375     uint8_t * buffer, uint16_t buffer_size, uint16_t buffer_offset);
376 
377 
378 /* API_END */
379 
380 #if defined __cplusplus
381 }
382 #endif
383 
384 #endif // BTSTACK_UTIL_H
385