src/utils/os.h

   1 /*
   2  * OS specific functions
   3  * Copyright (c) 2005-2009, Jouni Malinen <j@w1.fi>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  *
   9  * Alternatively, this software may be distributed under the terms of BSD
  10  * license.
  11  *
  12  * See README and COPYING for more details.
  13  */
  14
  15 #ifndef OS_H
  16 #define OS_H
  17
  18 typedef long os_time_t;
  19
  20 /**
  21  * os_sleep - Sleep (sec, usec)
  22  * @sec: Number of seconds to sleep
  23  * @usec: Number of microseconds to sleep
  24  */
  25 void os_sleep(os_time_t sec, os_time_t usec);
  26
  27 struct os_time {
  28         os_time_t sec;
  29         os_time_t usec;
  30 };
  31
  32 /**
  33  * os_get_time - Get current time (sec, usec)
  34  * @t: Pointer to buffer for the time
  35  * Returns: 0 on success, -1 on failure
  36  */
  37 int os_get_time(struct os_time *t);
  38
  39
  40 /* Helper macros for handling struct os_time */
  41
  42 #define os_time_before(a, b) \
  43         ((a)->sec < (b)->sec || \
  44          ((a)->sec == (b)->sec && (a)->usec < (b)->usec))
  45
  46 #define os_time_sub(a, b, res) do { \
  47         (res)->sec = (a)->sec - (b)->sec; \
  48         (res)->usec = (a)->usec - (b)->usec; \
  49         if ((res)->usec < 0) { \
  50                 (res)->sec--; \
  51                 (res)->usec += 1000000; \
  52         } \
  53 } while (0)
  54
  55 /**
  56  * os_mktime - Convert broken-down time into seconds since 1970-01-01
  57  * @year: Four digit year
  58  * @month: Month (1 .. 12)
  59  * @day: Day of month (1 .. 31)
  60  * @hour: Hour (0 .. 23)
  61  * @min: Minute (0 .. 59)
  62  * @sec: Second (0 .. 60)
  63  * @t: Buffer for returning calendar time representation (seconds since
  64  * 1970-01-01 00:00:00)
  65  * Returns: 0 on success, -1 on failure
  66  *
  67  * Note: The result is in seconds from Epoch, i.e., in UTC, not in local time
  68  * which is used by POSIX mktime().
  69  */
  70 int os_mktime(int year, int month, int day, int hour, int min, int sec,
  71               os_time_t *t);
  72
  73
  74 /**
  75  * os_daemonize - Run in the background (detach from the controlling terminal)
  76  * @pid_file: File name to write the process ID to or %NULL to skip this
  77  * Returns: 0 on success, -1 on failure
  78  */
  79 int os_daemonize(const char *pid_file);
  80
  81 /**
  82  * os_daemonize_terminate - Stop running in the background (remove pid file)
  83  * @pid_file: File name to write the process ID to or %NULL to skip this
  84  */
  85 void os_daemonize_terminate(const char *pid_file);
  86
  87 /**
  88  * os_get_random - Get cryptographically strong pseudo random data
  89  * @buf: Buffer for pseudo random data
  90  * @len: Length of the buffer
  91  * Returns: 0 on success, -1 on failure
  92  */
  93 int os_get_random(unsigned char *buf, size_t len);
  94
  95 /**
  96  * os_random - Get pseudo random value (not necessarily very strong)
  97  * Returns: Pseudo random value
  98  */
  99 unsigned long os_random(void);
 100
 101 /**
 102  * os_rel2abs_path - Get an absolute path for a file
 103  * @rel_path: Relative path to a file
 104  * Returns: Absolute path for the file or %NULL on failure
 105  *
 106  * This function tries to convert a relative path of a file to an absolute path
 107  * in order for the file to be found even if current working directory has
 108  * changed. The returned value is allocated and caller is responsible for
 109  * freeing it. It is acceptable to just return the same path in an allocated
 110  * buffer, e.g., return strdup(rel_path). This function is only used to find
 111  * configuration files when os_daemonize() may have changed the current working
 112  * directory and relative path would be pointing to a different location.
 113  */
 114 char * os_rel2abs_path(const char *rel_path);
 115
 116 /**
 117  * os_program_init - Program initialization (called at start)
 118  * Returns: 0 on success, -1 on failure
 119  *
 120  * This function is called when a programs starts. If there are any OS specific
 121  * processing that is needed, it can be placed here. It is also acceptable to
 122  * just return 0 if not special processing is needed.
 123  */
 124 int os_program_init(void);
 125
 126 /**
 127  * os_program_deinit - Program deinitialization (called just before exit)
 128  *
 129  * This function is called just before a program exists. If there are any OS
 130  * specific processing, e.g., freeing resourced allocated in os_program_init(),
 131  * it should be done here. It is also acceptable for this function to do
 132  * nothing.
 133  */
 134 void os_program_deinit(void);
 135
 136 /**
 137  * os_setenv - Set environment variable
 138  * @name: Name of the variable
 139  * @value: Value to set to the variable
 140  * @overwrite: Whether existing variable should be overwritten
 141  * Returns: 0 on success, -1 on error
 142  *
 143  * This function is only used for wpa_cli action scripts. OS wrapper does not
 144  * need to implement this if such functionality is not needed.
 145  */
 146 int os_setenv(const char *name, const char *value, int overwrite);
 147
 148 /**
 149  * os_unsetenv - Delete environent variable
 150  * @name: Name of the variable
 151  * Returns: 0 on success, -1 on error
 152  *
 153  * This function is only used for wpa_cli action scripts. OS wrapper does not
 154  * need to implement this if such functionality is not needed.
 155  */
 156 int os_unsetenv(const char *name);
 157
 158 /**
 159  * os_readfile - Read a file to an allocated memory buffer
 160  * @name: Name of the file to read
 161  * @len: For returning the length of the allocated buffer
 162  * Returns: Pointer to the allocated buffer or %NULL on failure
 163  *
 164  * This function allocates memory and reads the given file to this buffer. Both
 165  * binary and text files can be read with this function. The caller is
 166  * responsible for freeing the returned buffer with os_free().
 167  */
 168 char * os_readfile(const char *name, size_t *len);
 169
 170 /**
 171  * os_zalloc - Allocate and zero memory
 172  * @size: Number of bytes to allocate
 173  * Returns: Pointer to allocated and zeroed memory or %NULL on failure
 174  *
 175  * Caller is responsible for freeing the returned buffer with os_free().
 176  */
 177 void * os_zalloc(size_t size);
 178
 179
 180 /*
 181  * The following functions are wrapper for standard ANSI C or POSIX functions.
 182  * By default, they are just defined to use the standard function name and no
 183  * os_*.c implementation is needed for them. This avoids extra function calls
 184  * by allowing the C pre-processor take care of the function name mapping.
 185  *
 186  * If the target system uses a C library that does not provide these functions,
 187  * build_config.h can be used to define the wrappers to use a different
 188  * function name. This can be done on function-by-function basis since the
 189  * defines here are only used if build_config.h does not define the os_* name.
 190  * If needed, os_*.c file can be used to implement the functions that are not
 191  * included in the C library on the target system. Alternatively,
 192  * OS_NO_C_LIB_DEFINES can be defined to skip all defines here in which case
 193  * these functions need to be implemented in os_*.c file for the target system.
 194  */
 195
 196 #ifdef OS_NO_C_LIB_DEFINES
 197
 198 /**
 199  * os_malloc - Allocate dynamic memory
 200  * @size: Size of the buffer to allocate
 201  * Returns: Allocated buffer or %NULL on failure
 202  *
 203  * Caller is responsible for freeing the returned buffer with os_free().
 204  */
 205 void * os_malloc(size_t size);
 206
 207 /**
 208  * os_realloc - Re-allocate dynamic memory
 209  * @ptr: Old buffer from os_malloc() or os_realloc()
 210  * @size: Size of the new buffer
 211  * Returns: Allocated buffer or %NULL on failure
 212  *
 213  * Caller is responsible for freeing the returned buffer with os_free().
 214  * If re-allocation fails, %NULL is returned and the original buffer (ptr) is
 215  * not freed and caller is still responsible for freeing it.
 216  */
 217 void * os_realloc(void *ptr, size_t size);
 218
 219 /**
 220  * os_free - Free dynamic memory
 221  * @ptr: Old buffer from os_malloc() or os_realloc(); can be %NULL
 222  */
 223 void os_free(void *ptr);
 224
 225 /**
 226  * os_memcpy - Copy memory area
 227  * @dest: Destination
 228  * @src: Source
 229  * @n: Number of bytes to copy
 230  * Returns: dest
 231  *
 232  * The memory areas src and dst must not overlap. os_memmove() can be used with
 233  * overlapping memory.
 234  */
 235 void * os_memcpy(void *dest, const void *src, size_t n);
 236
 237 /**
 238  * os_memmove - Copy memory area
 239  * @dest: Destination
 240  * @src: Source
 241  * @n: Number of bytes to copy
 242  * Returns: dest
 243  *
 244  * The memory areas src and dst may overlap.
 245  */
 246 void * os_memmove(void *dest, const void *src, size_t n);
 247
 248 /**
 249  * os_memset - Fill memory with a constant byte
 250  * @s: Memory area to be filled
 251  * @c: Constant byte
 252  * @n: Number of bytes started from s to fill with c
 253  * Returns: s
 254  */
 255 void * os_memset(void *s, int c, size_t n);
 256
 257 /**
 258  * os_memcmp - Compare memory areas
 259  * @s1: First buffer
 260  * @s2: Second buffer
 261  * @n: Maximum numbers of octets to compare
 262  * Returns: An integer less than, equal to, or greater than zero if s1 is
 263  * found to be less than, to match, or be greater than s2. Only first n
 264  * characters will be compared.
 265  */
 266 int os_memcmp(const void *s1, const void *s2, size_t n);
 267
 268 /**
 269  * os_strdup - Duplicate a string
 270  * @s: Source string
 271  * Returns: Allocated buffer with the string copied into it or %NULL on failure
 272  *
 273  * Caller is responsible for freeing the returned buffer with os_free().
 274  */
 275 char * os_strdup(const char *s);
 276
 277 /**
 278  * os_strlen - Calculate the length of a string
 279  * @s: '\0' terminated string
 280  * Returns: Number of characters in s (not counting the '\0' terminator)
 281  */
 282 size_t os_strlen(const char *s);
 283
 284 /**
 285  * os_strcasecmp - Compare two strings ignoring case
 286  * @s1: First string
 287  * @s2: Second string
 288  * Returns: An integer less than, equal to, or greater than zero if s1 is
 289  * found to be less than, to match, or be greatred than s2
 290  */
 291 int os_strcasecmp(const char *s1, const char *s2);
 292
 293 /**
 294  * os_strncasecmp - Compare two strings ignoring case
 295  * @s1: First string
 296  * @s2: Second string
 297  * @n: Maximum numbers of characters to compare
 298  * Returns: An integer less than, equal to, or greater than zero if s1 is
 299  * found to be less than, to match, or be greater than s2. Only first n
 300  * characters will be compared.
 301  */
 302 int os_strncasecmp(const char *s1, const char *s2, size_t n);
 303
 304 /**
 305  * os_strchr - Locate the first occurrence of a character in string
 306  * @s: String
 307  * @c: Character to search for
 308  * Returns: Pointer to the matched character or %NULL if not found
 309  */
 310 char * os_strchr(const char *s, int c);
 311
 312 /**
 313  * os_strrchr - Locate the last occurrence of a character in string
 314  * @s: String
 315  * @c: Character to search for
 316  * Returns: Pointer to the matched character or %NULL if not found
 317  */
 318 char * os_strrchr(const char *s, int c);
 319
 320 /**
 321  * os_strcmp - Compare two strings
 322  * @s1: First string
 323  * @s2: Second string
 324  * Returns: An integer less than, equal to, or greater than zero if s1 is
 325  * found to be less than, to match, or be greatred than s2
 326  */
 327 int os_strcmp(const char *s1, const char *s2);
 328
 329 /**
 330  * os_strncmp - Compare two strings
 331  * @s1: First string
 332  * @s2: Second string
 333  * @n: Maximum numbers of characters to compare
 334  * Returns: An integer less than, equal to, or greater than zero if s1 is
 335  * found to be less than, to match, or be greater than s2. Only first n
 336  * characters will be compared.
 337  */
 338 int os_strncmp(const char *s1, const char *s2, size_t n);
 339
 340 /**
 341  * os_strncpy - Copy a string
 342  * @dest: Destination
 343  * @src: Source
 344  * @n: Maximum number of characters to copy
 345  * Returns: dest
 346  */
 347 char * os_strncpy(char *dest, const char *src, size_t n);
 348
 349 /**
 350  * os_strstr - Locate a substring
 351  * @haystack: String (haystack) to search from
 352  * @needle: Needle to search from haystack
 353  * Returns: Pointer to the beginning of the substring or %NULL if not found
 354  */
 355 char * os_strstr(const char *haystack, const char *needle);
 356
 357 /**
 358  * os_snprintf - Print to a memory buffer
 359  * @str: Memory buffer to print into
 360  * @size: Maximum length of the str buffer
 361  * @format: printf format
 362  * Returns: Number of characters printed (not including trailing '\0').
 363  *
 364  * If the output buffer is truncated, number of characters which would have
 365  * been written is returned. Since some C libraries return -1 in such a case,
 366  * the caller must be prepared on that value, too, to indicate truncation.
 367  *
 368  * Note: Some C library implementations of snprintf() may not guarantee null
 369  * termination in case the output is truncated. The OS wrapper function of
 370  * os_snprintf() should provide this guarantee, i.e., to null terminate the
 371  * output buffer if a C library version of the function is used and if that
 372  * function does not guarantee null termination.
 373  *
 374  * If the target system does not include snprintf(), see, e.g.,
 375  * http://www.ijs.si/software/snprintf/ for an example of a portable
 376  * implementation of snprintf.
 377  */
 378 int os_snprintf(char *str, size_t size, const char *format, ...);
 379
 380 #else /* OS_NO_C_LIB_DEFINES */
 381
 382 #ifdef WPA_TRACE
 383 void * os_malloc(size_t size);
 384 void * os_realloc(void *ptr, size_t size);
 385 void os_free(void *ptr);
 386 char * os_strdup(const char *s);
 387 #else /* WPA_TRACE */
 388 #ifndef os_malloc
 389 #define os_malloc(s) malloc((s))
 390 #endif
 391 #ifndef os_realloc
 392 #define os_realloc(p, s) realloc((p), (s))
 393 #endif
 394 #ifndef os_free
 395 #define os_free(p) free((p))
 396 #endif
 397 #ifndef os_strdup
 398 #ifdef _MSC_VER
 399 #define os_strdup(s) _strdup(s)
 400 #else
 401 #define os_strdup(s) strdup(s)
 402 #endif
 403 #endif
 404 #endif /* WPA_TRACE */
 405
 406 #ifndef os_memcpy
 407 #define os_memcpy(d, s, n) memcpy((d), (s), (n))
 408 #endif
 409 #ifndef os_memmove
 410 #define os_memmove(d, s, n) memmove((d), (s), (n))
 411 #endif
 412 #ifndef os_memset
 413 #define os_memset(s, c, n) memset(s, c, n)
 414 #endif
 415 #ifndef os_memcmp
 416 #define os_memcmp(s1, s2, n) memcmp((s1), (s2), (n))
 417 #endif
 418
 419 #ifndef os_strlen
 420 #define os_strlen(s) strlen(s)
 421 #endif
 422 #ifndef os_strcasecmp
 423 #ifdef _MSC_VER
 424 #define os_strcasecmp(s1, s2) _stricmp((s1), (s2))
 425 #else
 426 #define os_strcasecmp(s1, s2) strcasecmp((s1), (s2))
 427 #endif
 428 #endif
 429 #ifndef os_strncasecmp
 430 #ifdef _MSC_VER
 431 #define os_strncasecmp(s1, s2, n) _strnicmp((s1), (s2), (n))
 432 #else
 433 #define os_strncasecmp(s1, s2, n) strncasecmp((s1), (s2), (n))
 434 #endif
 435 #endif
 436 #ifndef os_strchr
 437 #define os_strchr(s, c) strchr((s), (c))
 438 #endif
 439 #ifndef os_strcmp
 440 #define os_strcmp(s1, s2) strcmp((s1), (s2))
 441 #endif
 442 #ifndef os_strncmp
 443 #define os_strncmp(s1, s2, n) strncmp((s1), (s2), (n))
 444 #endif
 445 #ifndef os_strncpy
 446 #define os_strncpy(d, s, n) strncpy((d), (s), (n))
 447 #endif
 448 #ifndef os_strrchr
 449 #define os_strrchr(s, c) strrchr((s), (c))
 450 #endif
 451 #ifndef os_strstr
 452 #define os_strstr(h, n) strstr((h), (n))
 453 #endif
 454
 455 #ifndef os_snprintf
 456 #ifdef _MSC_VER
 457 #define os_snprintf _snprintf
 458 #else
 459 #define os_snprintf snprintf
 460 #endif
 461 #endif
 462
 463 #endif /* OS_NO_C_LIB_DEFINES */
 464
 465
 466 /**
 467  * os_strlcpy - Copy a string with size bound and NUL-termination
 468  * @dest: Destination
 469  * @src: Source
 470  * @siz: Size of the target buffer
 471  * Returns: Total length of the target string (length of src) (not including
 472  * NUL-termination)
 473  *
 474  * This function matches in behavior with the strlcpy(3) function in OpenBSD.
 475  */
 476 size_t os_strlcpy(char *dest, const char *src, size_t siz);
 477
 478
 479 #ifdef OS_REJECT_C_LIB_FUNCTIONS
 480 #define malloc OS_DO_NOT_USE_malloc
 481 #define realloc OS_DO_NOT_USE_realloc
 482 #define free OS_DO_NOT_USE_free
 483 #define memcpy OS_DO_NOT_USE_memcpy
 484 #define memmove OS_DO_NOT_USE_memmove
 485 #define memset OS_DO_NOT_USE_memset
 486 #define memcmp OS_DO_NOT_USE_memcmp
 487 #undef strdup
 488 #define strdup OS_DO_NOT_USE_strdup
 489 #define strlen OS_DO_NOT_USE_strlen
 490 #define strcasecmp OS_DO_NOT_USE_strcasecmp
 491 #define strncasecmp OS_DO_NOT_USE_strncasecmp
 492 #undef strchr
 493 #define strchr OS_DO_NOT_USE_strchr
 494 #undef strcmp
 495 #define strcmp OS_DO_NOT_USE_strcmp
 496 #undef strncmp
 497 #define strncmp OS_DO_NOT_USE_strncmp
 498 #undef strncpy
 499 #define strncpy OS_DO_NOT_USE_strncpy
 500 #define strrchr OS_DO_NOT_USE_strrchr
 501 #define strstr OS_DO_NOT_USE_strstr
 502 #undef snprintf
 503 #define snprintf OS_DO_NOT_USE_snprintf
 504
 505 #define strcpy OS_DO_NOT_USE_strcpy
 506 #endif /* OS_REJECT_C_LIB_FUNCTIONS */
 507
 508 #endif /* OS_H */