xref: /freebsd/contrib/wpa/src/utils/os.h (revision 05248206f720394d95c2a7475429311df670a2e9)
1 /*
2  * OS specific functions
3  * Copyright (c) 2005-2009, Jouni Malinen <j@w1.fi>
4  *
5  * This software may be distributed under the terms of the BSD license.
6  * See README for more details.
7  */
8 
9 #ifndef OS_H
10 #define OS_H
11 
12 typedef long os_time_t;
13 
14 /**
15  * os_sleep - Sleep (sec, usec)
16  * @sec: Number of seconds to sleep
17  * @usec: Number of microseconds to sleep
18  */
19 void os_sleep(os_time_t sec, os_time_t usec);
20 
21 struct os_time {
22 	os_time_t sec;
23 	os_time_t usec;
24 };
25 
26 struct os_reltime {
27 	os_time_t sec;
28 	os_time_t usec;
29 };
30 
31 /**
32  * os_get_time - Get current time (sec, usec)
33  * @t: Pointer to buffer for the time
34  * Returns: 0 on success, -1 on failure
35  */
36 int os_get_time(struct os_time *t);
37 
38 /**
39  * os_get_reltime - Get relative time (sec, usec)
40  * @t: Pointer to buffer for the time
41  * Returns: 0 on success, -1 on failure
42  */
43 int os_get_reltime(struct os_reltime *t);
44 
45 
46 /* Helpers for handling struct os_time */
47 
48 static inline int os_time_before(struct os_time *a, struct os_time *b)
49 {
50 	return (a->sec < b->sec) ||
51 	       (a->sec == b->sec && a->usec < b->usec);
52 }
53 
54 
55 static inline void os_time_sub(struct os_time *a, struct os_time *b,
56 			       struct os_time *res)
57 {
58 	res->sec = a->sec - b->sec;
59 	res->usec = a->usec - b->usec;
60 	if (res->usec < 0) {
61 		res->sec--;
62 		res->usec += 1000000;
63 	}
64 }
65 
66 
67 /* Helpers for handling struct os_reltime */
68 
69 static inline int os_reltime_before(struct os_reltime *a,
70 				    struct os_reltime *b)
71 {
72 	return (a->sec < b->sec) ||
73 	       (a->sec == b->sec && a->usec < b->usec);
74 }
75 
76 
77 static inline void os_reltime_sub(struct os_reltime *a, struct os_reltime *b,
78 				  struct os_reltime *res)
79 {
80 	res->sec = a->sec - b->sec;
81 	res->usec = a->usec - b->usec;
82 	if (res->usec < 0) {
83 		res->sec--;
84 		res->usec += 1000000;
85 	}
86 }
87 
88 
89 static inline void os_reltime_age(struct os_reltime *start,
90 				  struct os_reltime *age)
91 {
92 	struct os_reltime now;
93 
94 	os_get_reltime(&now);
95 	os_reltime_sub(&now, start, age);
96 }
97 
98 
99 static inline int os_reltime_expired(struct os_reltime *now,
100 				     struct os_reltime *ts,
101 				     os_time_t timeout_secs)
102 {
103 	struct os_reltime age;
104 
105 	os_reltime_sub(now, ts, &age);
106 	return (age.sec > timeout_secs) ||
107 	       (age.sec == timeout_secs && age.usec > 0);
108 }
109 
110 
111 static inline int os_reltime_initialized(struct os_reltime *t)
112 {
113 	return t->sec != 0 || t->usec != 0;
114 }
115 
116 
117 /**
118  * os_mktime - Convert broken-down time into seconds since 1970-01-01
119  * @year: Four digit year
120  * @month: Month (1 .. 12)
121  * @day: Day of month (1 .. 31)
122  * @hour: Hour (0 .. 23)
123  * @min: Minute (0 .. 59)
124  * @sec: Second (0 .. 60)
125  * @t: Buffer for returning calendar time representation (seconds since
126  * 1970-01-01 00:00:00)
127  * Returns: 0 on success, -1 on failure
128  *
129  * Note: The result is in seconds from Epoch, i.e., in UTC, not in local time
130  * which is used by POSIX mktime().
131  */
132 int os_mktime(int year, int month, int day, int hour, int min, int sec,
133 	      os_time_t *t);
134 
135 struct os_tm {
136 	int sec; /* 0..59 or 60 for leap seconds */
137 	int min; /* 0..59 */
138 	int hour; /* 0..23 */
139 	int day; /* 1..31 */
140 	int month; /* 1..12 */
141 	int year; /* Four digit year */
142 };
143 
144 int os_gmtime(os_time_t t, struct os_tm *tm);
145 
146 /**
147  * os_daemonize - Run in the background (detach from the controlling terminal)
148  * @pid_file: File name to write the process ID to or %NULL to skip this
149  * Returns: 0 on success, -1 on failure
150  */
151 int os_daemonize(const char *pid_file);
152 
153 /**
154  * os_daemonize_terminate - Stop running in the background (remove pid file)
155  * @pid_file: File name to write the process ID to or %NULL to skip this
156  */
157 void os_daemonize_terminate(const char *pid_file);
158 
159 /**
160  * os_get_random - Get cryptographically strong pseudo random data
161  * @buf: Buffer for pseudo random data
162  * @len: Length of the buffer
163  * Returns: 0 on success, -1 on failure
164  */
165 int os_get_random(unsigned char *buf, size_t len);
166 
167 /**
168  * os_random - Get pseudo random value (not necessarily very strong)
169  * Returns: Pseudo random value
170  */
171 unsigned long os_random(void);
172 
173 /**
174  * os_rel2abs_path - Get an absolute path for a file
175  * @rel_path: Relative path to a file
176  * Returns: Absolute path for the file or %NULL on failure
177  *
178  * This function tries to convert a relative path of a file to an absolute path
179  * in order for the file to be found even if current working directory has
180  * changed. The returned value is allocated and caller is responsible for
181  * freeing it. It is acceptable to just return the same path in an allocated
182  * buffer, e.g., return strdup(rel_path). This function is only used to find
183  * configuration files when os_daemonize() may have changed the current working
184  * directory and relative path would be pointing to a different location.
185  */
186 char * os_rel2abs_path(const char *rel_path);
187 
188 /**
189  * os_program_init - Program initialization (called at start)
190  * Returns: 0 on success, -1 on failure
191  *
192  * This function is called when a programs starts. If there are any OS specific
193  * processing that is needed, it can be placed here. It is also acceptable to
194  * just return 0 if not special processing is needed.
195  */
196 int os_program_init(void);
197 
198 /**
199  * os_program_deinit - Program deinitialization (called just before exit)
200  *
201  * This function is called just before a program exists. If there are any OS
202  * specific processing, e.g., freeing resourced allocated in os_program_init(),
203  * it should be done here. It is also acceptable for this function to do
204  * nothing.
205  */
206 void os_program_deinit(void);
207 
208 /**
209  * os_setenv - Set environment variable
210  * @name: Name of the variable
211  * @value: Value to set to the variable
212  * @overwrite: Whether existing variable should be overwritten
213  * Returns: 0 on success, -1 on error
214  *
215  * This function is only used for wpa_cli action scripts. OS wrapper does not
216  * need to implement this if such functionality is not needed.
217  */
218 int os_setenv(const char *name, const char *value, int overwrite);
219 
220 /**
221  * os_unsetenv - Delete environent variable
222  * @name: Name of the variable
223  * Returns: 0 on success, -1 on error
224  *
225  * This function is only used for wpa_cli action scripts. OS wrapper does not
226  * need to implement this if such functionality is not needed.
227  */
228 int os_unsetenv(const char *name);
229 
230 /**
231  * os_readfile - Read a file to an allocated memory buffer
232  * @name: Name of the file to read
233  * @len: For returning the length of the allocated buffer
234  * Returns: Pointer to the allocated buffer or %NULL on failure
235  *
236  * This function allocates memory and reads the given file to this buffer. Both
237  * binary and text files can be read with this function. The caller is
238  * responsible for freeing the returned buffer with os_free().
239  */
240 char * os_readfile(const char *name, size_t *len);
241 
242 /**
243  * os_file_exists - Check whether the specified file exists
244  * @fname: Path and name of the file
245  * Returns: 1 if the file exists or 0 if not
246  */
247 int os_file_exists(const char *fname);
248 
249 /**
250  * os_fdatasync - Sync a file's (for a given stream) state with storage device
251  * @stream: the stream to be flushed
252  * Returns: 0 if the operation succeeded or -1 on failure
253  */
254 int os_fdatasync(FILE *stream);
255 
256 /**
257  * os_zalloc - Allocate and zero memory
258  * @size: Number of bytes to allocate
259  * Returns: Pointer to allocated and zeroed memory or %NULL on failure
260  *
261  * Caller is responsible for freeing the returned buffer with os_free().
262  */
263 void * os_zalloc(size_t size);
264 
265 /**
266  * os_calloc - Allocate and zero memory for an array
267  * @nmemb: Number of members in the array
268  * @size: Number of bytes in each member
269  * Returns: Pointer to allocated and zeroed memory or %NULL on failure
270  *
271  * This function can be used as a wrapper for os_zalloc(nmemb * size) when an
272  * allocation is used for an array. The main benefit over os_zalloc() is in
273  * having an extra check to catch integer overflows in multiplication.
274  *
275  * Caller is responsible for freeing the returned buffer with os_free().
276  */
277 static inline void * os_calloc(size_t nmemb, size_t size)
278 {
279 	if (size && nmemb > (~(size_t) 0) / size)
280 		return NULL;
281 	return os_zalloc(nmemb * size);
282 }
283 
284 
285 /*
286  * The following functions are wrapper for standard ANSI C or POSIX functions.
287  * By default, they are just defined to use the standard function name and no
288  * os_*.c implementation is needed for them. This avoids extra function calls
289  * by allowing the C pre-processor take care of the function name mapping.
290  *
291  * If the target system uses a C library that does not provide these functions,
292  * build_config.h can be used to define the wrappers to use a different
293  * function name. This can be done on function-by-function basis since the
294  * defines here are only used if build_config.h does not define the os_* name.
295  * If needed, os_*.c file can be used to implement the functions that are not
296  * included in the C library on the target system. Alternatively,
297  * OS_NO_C_LIB_DEFINES can be defined to skip all defines here in which case
298  * these functions need to be implemented in os_*.c file for the target system.
299  */
300 
301 #ifdef OS_NO_C_LIB_DEFINES
302 
303 /**
304  * os_malloc - Allocate dynamic memory
305  * @size: Size of the buffer to allocate
306  * Returns: Allocated buffer or %NULL on failure
307  *
308  * Caller is responsible for freeing the returned buffer with os_free().
309  */
310 void * os_malloc(size_t size);
311 
312 /**
313  * os_realloc - Re-allocate dynamic memory
314  * @ptr: Old buffer from os_malloc() or os_realloc()
315  * @size: Size of the new buffer
316  * Returns: Allocated buffer or %NULL on failure
317  *
318  * Caller is responsible for freeing the returned buffer with os_free().
319  * If re-allocation fails, %NULL is returned and the original buffer (ptr) is
320  * not freed and caller is still responsible for freeing it.
321  */
322 void * os_realloc(void *ptr, size_t size);
323 
324 /**
325  * os_free - Free dynamic memory
326  * @ptr: Old buffer from os_malloc() or os_realloc(); can be %NULL
327  */
328 void os_free(void *ptr);
329 
330 /**
331  * os_memcpy - Copy memory area
332  * @dest: Destination
333  * @src: Source
334  * @n: Number of bytes to copy
335  * Returns: dest
336  *
337  * The memory areas src and dst must not overlap. os_memmove() can be used with
338  * overlapping memory.
339  */
340 void * os_memcpy(void *dest, const void *src, size_t n);
341 
342 /**
343  * os_memmove - Copy memory area
344  * @dest: Destination
345  * @src: Source
346  * @n: Number of bytes to copy
347  * Returns: dest
348  *
349  * The memory areas src and dst may overlap.
350  */
351 void * os_memmove(void *dest, const void *src, size_t n);
352 
353 /**
354  * os_memset - Fill memory with a constant byte
355  * @s: Memory area to be filled
356  * @c: Constant byte
357  * @n: Number of bytes started from s to fill with c
358  * Returns: s
359  */
360 void * os_memset(void *s, int c, size_t n);
361 
362 /**
363  * os_memcmp - Compare memory areas
364  * @s1: First buffer
365  * @s2: Second buffer
366  * @n: Maximum numbers of octets to compare
367  * Returns: An integer less than, equal to, or greater than zero if s1 is
368  * found to be less than, to match, or be greater than s2. Only first n
369  * characters will be compared.
370  */
371 int os_memcmp(const void *s1, const void *s2, size_t n);
372 
373 /**
374  * os_strdup - Duplicate a string
375  * @s: Source string
376  * Returns: Allocated buffer with the string copied into it or %NULL on failure
377  *
378  * Caller is responsible for freeing the returned buffer with os_free().
379  */
380 char * os_strdup(const char *s);
381 
382 /**
383  * os_strlen - Calculate the length of a string
384  * @s: '\0' terminated string
385  * Returns: Number of characters in s (not counting the '\0' terminator)
386  */
387 size_t os_strlen(const char *s);
388 
389 /**
390  * os_strcasecmp - Compare two strings ignoring case
391  * @s1: First string
392  * @s2: Second string
393  * Returns: An integer less than, equal to, or greater than zero if s1 is
394  * found to be less than, to match, or be greatred than s2
395  */
396 int os_strcasecmp(const char *s1, const char *s2);
397 
398 /**
399  * os_strncasecmp - Compare two strings ignoring case
400  * @s1: First string
401  * @s2: Second string
402  * @n: Maximum numbers of characters to compare
403  * Returns: An integer less than, equal to, or greater than zero if s1 is
404  * found to be less than, to match, or be greater than s2. Only first n
405  * characters will be compared.
406  */
407 int os_strncasecmp(const char *s1, const char *s2, size_t n);
408 
409 /**
410  * os_strchr - Locate the first occurrence of a character in string
411  * @s: String
412  * @c: Character to search for
413  * Returns: Pointer to the matched character or %NULL if not found
414  */
415 char * os_strchr(const char *s, int c);
416 
417 /**
418  * os_strrchr - Locate the last occurrence of a character in string
419  * @s: String
420  * @c: Character to search for
421  * Returns: Pointer to the matched character or %NULL if not found
422  */
423 char * os_strrchr(const char *s, int c);
424 
425 /**
426  * os_strcmp - Compare two strings
427  * @s1: First string
428  * @s2: Second string
429  * Returns: An integer less than, equal to, or greater than zero if s1 is
430  * found to be less than, to match, or be greatred than s2
431  */
432 int os_strcmp(const char *s1, const char *s2);
433 
434 /**
435  * os_strncmp - Compare two strings
436  * @s1: First string
437  * @s2: Second string
438  * @n: Maximum numbers of characters to compare
439  * Returns: An integer less than, equal to, or greater than zero if s1 is
440  * found to be less than, to match, or be greater than s2. Only first n
441  * characters will be compared.
442  */
443 int os_strncmp(const char *s1, const char *s2, size_t n);
444 
445 /**
446  * os_strstr - Locate a substring
447  * @haystack: String (haystack) to search from
448  * @needle: Needle to search from haystack
449  * Returns: Pointer to the beginning of the substring or %NULL if not found
450  */
451 char * os_strstr(const char *haystack, const char *needle);
452 
453 /**
454  * os_snprintf - Print to a memory buffer
455  * @str: Memory buffer to print into
456  * @size: Maximum length of the str buffer
457  * @format: printf format
458  * Returns: Number of characters printed (not including trailing '\0').
459  *
460  * If the output buffer is truncated, number of characters which would have
461  * been written is returned. Since some C libraries return -1 in such a case,
462  * the caller must be prepared on that value, too, to indicate truncation.
463  *
464  * Note: Some C library implementations of snprintf() may not guarantee null
465  * termination in case the output is truncated. The OS wrapper function of
466  * os_snprintf() should provide this guarantee, i.e., to null terminate the
467  * output buffer if a C library version of the function is used and if that
468  * function does not guarantee null termination.
469  *
470  * If the target system does not include snprintf(), see, e.g.,
471  * http://www.ijs.si/software/snprintf/ for an example of a portable
472  * implementation of snprintf.
473  */
474 int os_snprintf(char *str, size_t size, const char *format, ...);
475 
476 #else /* OS_NO_C_LIB_DEFINES */
477 
478 #ifdef WPA_TRACE
479 void * os_malloc(size_t size);
480 void * os_realloc(void *ptr, size_t size);
481 void os_free(void *ptr);
482 char * os_strdup(const char *s);
483 #else /* WPA_TRACE */
484 #ifndef os_malloc
485 #define os_malloc(s) malloc((s))
486 #endif
487 #ifndef os_realloc
488 #define os_realloc(p, s) realloc((p), (s))
489 #endif
490 #ifndef os_free
491 #define os_free(p) free((p))
492 #endif
493 #ifndef os_strdup
494 #ifdef _MSC_VER
495 #define os_strdup(s) _strdup(s)
496 #else
497 #define os_strdup(s) strdup(s)
498 #endif
499 #endif
500 #endif /* WPA_TRACE */
501 
502 #ifndef os_memcpy
503 #define os_memcpy(d, s, n) memcpy((d), (s), (n))
504 #endif
505 #ifndef os_memmove
506 #define os_memmove(d, s, n) memmove((d), (s), (n))
507 #endif
508 #ifndef os_memset
509 #define os_memset(s, c, n) memset(s, c, n)
510 #endif
511 #ifndef os_memcmp
512 #define os_memcmp(s1, s2, n) memcmp((s1), (s2), (n))
513 #endif
514 
515 #ifndef os_strlen
516 #define os_strlen(s) strlen(s)
517 #endif
518 #ifndef os_strcasecmp
519 #ifdef _MSC_VER
520 #define os_strcasecmp(s1, s2) _stricmp((s1), (s2))
521 #else
522 #define os_strcasecmp(s1, s2) strcasecmp((s1), (s2))
523 #endif
524 #endif
525 #ifndef os_strncasecmp
526 #ifdef _MSC_VER
527 #define os_strncasecmp(s1, s2, n) _strnicmp((s1), (s2), (n))
528 #else
529 #define os_strncasecmp(s1, s2, n) strncasecmp((s1), (s2), (n))
530 #endif
531 #endif
532 #ifndef os_strchr
533 #define os_strchr(s, c) strchr((s), (c))
534 #endif
535 #ifndef os_strcmp
536 #define os_strcmp(s1, s2) strcmp((s1), (s2))
537 #endif
538 #ifndef os_strncmp
539 #define os_strncmp(s1, s2, n) strncmp((s1), (s2), (n))
540 #endif
541 #ifndef os_strrchr
542 #define os_strrchr(s, c) strrchr((s), (c))
543 #endif
544 #ifndef os_strstr
545 #define os_strstr(h, n) strstr((h), (n))
546 #endif
547 
548 #ifndef os_snprintf
549 #ifdef _MSC_VER
550 #define os_snprintf _snprintf
551 #else
552 #define os_snprintf snprintf
553 #endif
554 #endif
555 
556 #endif /* OS_NO_C_LIB_DEFINES */
557 
558 
559 static inline int os_snprintf_error(size_t size, int res)
560 {
561 	return res < 0 || (unsigned int) res >= size;
562 }
563 
564 
565 static inline void * os_realloc_array(void *ptr, size_t nmemb, size_t size)
566 {
567 	if (size && nmemb > (~(size_t) 0) / size)
568 		return NULL;
569 	return os_realloc(ptr, nmemb * size);
570 }
571 
572 /**
573  * os_remove_in_array - Remove a member from an array by index
574  * @ptr: Pointer to the array
575  * @nmemb: Current member count of the array
576  * @size: The size per member of the array
577  * @idx: Index of the member to be removed
578  */
579 static inline void os_remove_in_array(void *ptr, size_t nmemb, size_t size,
580 				      size_t idx)
581 {
582 	if (idx < nmemb - 1)
583 		os_memmove(((unsigned char *) ptr) + idx * size,
584 			   ((unsigned char *) ptr) + (idx + 1) * size,
585 			   (nmemb - idx - 1) * size);
586 }
587 
588 /**
589  * os_strlcpy - Copy a string with size bound and NUL-termination
590  * @dest: Destination
591  * @src: Source
592  * @siz: Size of the target buffer
593  * Returns: Total length of the target string (length of src) (not including
594  * NUL-termination)
595  *
596  * This function matches in behavior with the strlcpy(3) function in OpenBSD.
597  */
598 size_t os_strlcpy(char *dest, const char *src, size_t siz);
599 
600 /**
601  * os_memcmp_const - Constant time memory comparison
602  * @a: First buffer to compare
603  * @b: Second buffer to compare
604  * @len: Number of octets to compare
605  * Returns: 0 if buffers are equal, non-zero if not
606  *
607  * This function is meant for comparing passwords or hash values where
608  * difference in execution time could provide external observer information
609  * about the location of the difference in the memory buffers. The return value
610  * does not behave like os_memcmp(), i.e., os_memcmp_const() cannot be used to
611  * sort items into a defined order. Unlike os_memcmp(), execution time of
612  * os_memcmp_const() does not depend on the contents of the compared memory
613  * buffers, but only on the total compared length.
614  */
615 int os_memcmp_const(const void *a, const void *b, size_t len);
616 
617 
618 /**
619  * os_memdup - Allocate duplicate of passed memory chunk
620  * @src: Source buffer to duplicate
621  * @len: Length of source buffer
622  * Returns: %NULL if allocation failed, copy of src buffer otherwise
623  *
624  * This function allocates a memory block like os_malloc() would, and
625  * copies the given source buffer into it.
626  */
627 void * os_memdup(const void *src, size_t len);
628 
629 /**
630  * os_exec - Execute an external program
631  * @program: Path to the program
632  * @arg: Command line argument string
633  * @wait_completion: Whether to wait until the program execution completes
634  * Returns: 0 on success, -1 on error
635  */
636 int os_exec(const char *program, const char *arg, int wait_completion);
637 
638 
639 #ifdef OS_REJECT_C_LIB_FUNCTIONS
640 #define malloc OS_DO_NOT_USE_malloc
641 #define realloc OS_DO_NOT_USE_realloc
642 #define free OS_DO_NOT_USE_free
643 #define memcpy OS_DO_NOT_USE_memcpy
644 #define memmove OS_DO_NOT_USE_memmove
645 #define memset OS_DO_NOT_USE_memset
646 #define memcmp OS_DO_NOT_USE_memcmp
647 #undef strdup
648 #define strdup OS_DO_NOT_USE_strdup
649 #define strlen OS_DO_NOT_USE_strlen
650 #define strcasecmp OS_DO_NOT_USE_strcasecmp
651 #define strncasecmp OS_DO_NOT_USE_strncasecmp
652 #undef strchr
653 #define strchr OS_DO_NOT_USE_strchr
654 #undef strcmp
655 #define strcmp OS_DO_NOT_USE_strcmp
656 #undef strncmp
657 #define strncmp OS_DO_NOT_USE_strncmp
658 #undef strncpy
659 #define strncpy OS_DO_NOT_USE_strncpy
660 #define strrchr OS_DO_NOT_USE_strrchr
661 #define strstr OS_DO_NOT_USE_strstr
662 #undef snprintf
663 #define snprintf OS_DO_NOT_USE_snprintf
664 
665 #define strcpy OS_DO_NOT_USE_strcpy
666 #endif /* OS_REJECT_C_LIB_FUNCTIONS */
667 
668 
669 #if defined(WPA_TRACE_BFD) && defined(CONFIG_TESTING_OPTIONS)
670 #define TEST_FAIL() testing_test_fail()
671 int testing_test_fail(void);
672 extern char wpa_trace_fail_func[256];
673 extern unsigned int wpa_trace_fail_after;
674 extern char wpa_trace_test_fail_func[256];
675 extern unsigned int wpa_trace_test_fail_after;
676 #else
677 #define TEST_FAIL() 0
678 #endif
679 
680 #endif /* OS_H */
681