1 /*
2  * wpa_supplicant/hostapd / OS specific functions
3  * Copyright (c) 2005-2006, 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 #ifndef os_malloc
383 #define os_malloc(s) malloc((s))
384 #endif
385 #ifndef os_realloc
386 #define os_realloc(p, s) realloc((p), (s))
387 #endif
388 #ifndef os_free
389 #define os_free(p) free((p))
390 #endif
391 
392 #ifndef os_memcpy
393 #define os_memcpy(d, s, n) memcpy((d), (s), (n))
394 #endif
395 #ifndef os_memmove
396 #define os_memmove(d, s, n) memmove((d), (s), (n))
397 #endif
398 #ifndef os_memset
399 #define os_memset(s, c, n) memset(s, c, n)
400 #endif
401 #ifndef os_memcmp
402 #define os_memcmp(s1, s2, n) memcmp((s1), (s2), (n))
403 #endif
404 
405 #ifndef os_strdup
406 #ifdef _MSC_VER
407 #define os_strdup(s) _strdup(s)
408 #else
409 #define os_strdup(s) strdup(s)
410 #endif
411 #endif
412 #ifndef os_strlen
413 #define os_strlen(s) strlen(s)
414 #endif
415 #ifndef os_strcasecmp
416 #ifdef _MSC_VER
417 #define os_strcasecmp(s1, s2) _stricmp((s1), (s2))
418 #else
419 #define os_strcasecmp(s1, s2) strcasecmp((s1), (s2))
420 #endif
421 #endif
422 #ifndef os_strncasecmp
423 #ifdef _MSC_VER
424 #define os_strncasecmp(s1, s2, n) _strnicmp((s1), (s2), (n))
425 #else
426 #define os_strncasecmp(s1, s2, n) strncasecmp((s1), (s2), (n))
427 #endif
428 #endif
429 #ifndef os_strchr
430 #define os_strchr(s, c) strchr((s), (c))
431 #endif
432 #ifndef os_strcmp
433 #define os_strcmp(s1, s2) strcmp((s1), (s2))
434 #endif
435 #ifndef os_strncmp
436 #define os_strncmp(s1, s2, n) strncmp((s1), (s2), (n))
437 #endif
438 #ifndef os_strncpy
439 #define os_strncpy(d, s, n) strncpy((d), (s), (n))
440 #endif
441 #ifndef os_strrchr
442 #define os_strrchr(s, c) strrchr((s), (c))
443 #endif
444 #ifndef os_strstr
445 #define os_strstr(h, n) strstr((h), (n))
446 #endif
447 
448 #ifndef os_snprintf
449 #ifdef _MSC_VER
450 #define os_snprintf _snprintf
451 #else
452 #define os_snprintf snprintf
453 #endif
454 #endif
455 
456 #endif /* OS_NO_C_LIB_DEFINES */
457 
458 
459 /**
460  * os_strlcpy - Copy a string with size bound and NUL-termination
461  * @dest: Destination
462  * @src: Source
463  * @siz: Size of the target buffer
464  * Returns: Total length of the target string (length of src) (not including
465  * NUL-termination)
466  *
467  * This function matches in behavior with the strlcpy(3) function in OpenBSD.
468  */
469 size_t os_strlcpy(char *dest, const char *src, size_t siz);
470 
471 
472 #ifdef OS_REJECT_C_LIB_FUNCTIONS
473 #define malloc OS_DO_NOT_USE_malloc
474 #define realloc OS_DO_NOT_USE_realloc
475 #define free OS_DO_NOT_USE_free
476 #define memcpy OS_DO_NOT_USE_memcpy
477 #define memmove OS_DO_NOT_USE_memmove
478 #define memset OS_DO_NOT_USE_memset
479 #define memcmp OS_DO_NOT_USE_memcmp
480 #undef strdup
481 #define strdup OS_DO_NOT_USE_strdup
482 #define strlen OS_DO_NOT_USE_strlen
483 #define strcasecmp OS_DO_NOT_USE_strcasecmp
484 #define strncasecmp OS_DO_NOT_USE_strncasecmp
485 #undef strchr
486 #define strchr OS_DO_NOT_USE_strchr
487 #undef strcmp
488 #define strcmp OS_DO_NOT_USE_strcmp
489 #undef strncmp
490 #define strncmp OS_DO_NOT_USE_strncmp
491 #undef strncpy
492 #define strncpy OS_DO_NOT_USE_strncpy
493 #define strrchr OS_DO_NOT_USE_strrchr
494 #define strstr OS_DO_NOT_USE_strstr
495 #undef snprintf
496 #define snprintf OS_DO_NOT_USE_snprintf
497 
498 #define strcpy OS_DO_NOT_USE_strcpy
499 #endif /* OS_REJECT_C_LIB_FUNCTIONS */
500 
501 #endif /* OS_H */
502