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      1 /*
      2  * OS specific functions
      3  * Copyright (c) 2005-2009, Jouni Malinen <j (at) 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_zalloc - Allocate and zero memory
    251  * @size: Number of bytes to allocate
    252  * Returns: Pointer to allocated and zeroed memory or %NULL on failure
    253  *
    254  * Caller is responsible for freeing the returned buffer with os_free().
    255  */
    256 void * os_zalloc(size_t size);
    257 
    258 /**
    259  * os_calloc - Allocate and zero memory for an array
    260  * @nmemb: Number of members in the array
    261  * @size: Number of bytes in each member
    262  * Returns: Pointer to allocated and zeroed memory or %NULL on failure
    263  *
    264  * This function can be used as a wrapper for os_zalloc(nmemb * size) when an
    265  * allocation is used for an array. The main benefit over os_zalloc() is in
    266  * having an extra check to catch integer overflows in multiplication.
    267  *
    268  * Caller is responsible for freeing the returned buffer with os_free().
    269  */
    270 static inline void * os_calloc(size_t nmemb, size_t size)
    271 {
    272 	if (size && nmemb > (~(size_t) 0) / size)
    273 		return NULL;
    274 	return os_zalloc(nmemb * size);
    275 }
    276 
    277 
    278 /*
    279  * The following functions are wrapper for standard ANSI C or POSIX functions.
    280  * By default, they are just defined to use the standard function name and no
    281  * os_*.c implementation is needed for them. This avoids extra function calls
    282  * by allowing the C pre-processor take care of the function name mapping.
    283  *
    284  * If the target system uses a C library that does not provide these functions,
    285  * build_config.h can be used to define the wrappers to use a different
    286  * function name. This can be done on function-by-function basis since the
    287  * defines here are only used if build_config.h does not define the os_* name.
    288  * If needed, os_*.c file can be used to implement the functions that are not
    289  * included in the C library on the target system. Alternatively,
    290  * OS_NO_C_LIB_DEFINES can be defined to skip all defines here in which case
    291  * these functions need to be implemented in os_*.c file for the target system.
    292  */
    293 
    294 #ifdef OS_NO_C_LIB_DEFINES
    295 
    296 /**
    297  * os_malloc - Allocate dynamic memory
    298  * @size: Size of the buffer to allocate
    299  * Returns: Allocated buffer or %NULL on failure
    300  *
    301  * Caller is responsible for freeing the returned buffer with os_free().
    302  */
    303 void * os_malloc(size_t size);
    304 
    305 /**
    306  * os_realloc - Re-allocate dynamic memory
    307  * @ptr: Old buffer from os_malloc() or os_realloc()
    308  * @size: Size of the new buffer
    309  * Returns: Allocated buffer or %NULL on failure
    310  *
    311  * Caller is responsible for freeing the returned buffer with os_free().
    312  * If re-allocation fails, %NULL is returned and the original buffer (ptr) is
    313  * not freed and caller is still responsible for freeing it.
    314  */
    315 void * os_realloc(void *ptr, size_t size);
    316 
    317 /**
    318  * os_free - Free dynamic memory
    319  * @ptr: Old buffer from os_malloc() or os_realloc(); can be %NULL
    320  */
    321 void os_free(void *ptr);
    322 
    323 /**
    324  * os_memcpy - Copy memory area
    325  * @dest: Destination
    326  * @src: Source
    327  * @n: Number of bytes to copy
    328  * Returns: dest
    329  *
    330  * The memory areas src and dst must not overlap. os_memmove() can be used with
    331  * overlapping memory.
    332  */
    333 void * os_memcpy(void *dest, const void *src, size_t n);
    334 
    335 /**
    336  * os_memmove - Copy memory area
    337  * @dest: Destination
    338  * @src: Source
    339  * @n: Number of bytes to copy
    340  * Returns: dest
    341  *
    342  * The memory areas src and dst may overlap.
    343  */
    344 void * os_memmove(void *dest, const void *src, size_t n);
    345 
    346 /**
    347  * os_memset - Fill memory with a constant byte
    348  * @s: Memory area to be filled
    349  * @c: Constant byte
    350  * @n: Number of bytes started from s to fill with c
    351  * Returns: s
    352  */
    353 void * os_memset(void *s, int c, size_t n);
    354 
    355 /**
    356  * os_memcmp - Compare memory areas
    357  * @s1: First buffer
    358  * @s2: Second buffer
    359  * @n: Maximum numbers of octets to compare
    360  * Returns: An integer less than, equal to, or greater than zero if s1 is
    361  * found to be less than, to match, or be greater than s2. Only first n
    362  * characters will be compared.
    363  */
    364 int os_memcmp(const void *s1, const void *s2, size_t n);
    365 
    366 /**
    367  * os_strdup - Duplicate a string
    368  * @s: Source string
    369  * Returns: Allocated buffer with the string copied into it or %NULL on failure
    370  *
    371  * Caller is responsible for freeing the returned buffer with os_free().
    372  */
    373 char * os_strdup(const char *s);
    374 
    375 /**
    376  * os_strlen - Calculate the length of a string
    377  * @s: '\0' terminated string
    378  * Returns: Number of characters in s (not counting the '\0' terminator)
    379  */
    380 size_t os_strlen(const char *s);
    381 
    382 /**
    383  * os_strcasecmp - Compare two strings ignoring case
    384  * @s1: First string
    385  * @s2: Second string
    386  * Returns: An integer less than, equal to, or greater than zero if s1 is
    387  * found to be less than, to match, or be greatred than s2
    388  */
    389 int os_strcasecmp(const char *s1, const char *s2);
    390 
    391 /**
    392  * os_strncasecmp - Compare two strings ignoring case
    393  * @s1: First string
    394  * @s2: Second string
    395  * @n: Maximum numbers of characters to compare
    396  * Returns: An integer less than, equal to, or greater than zero if s1 is
    397  * found to be less than, to match, or be greater than s2. Only first n
    398  * characters will be compared.
    399  */
    400 int os_strncasecmp(const char *s1, const char *s2, size_t n);
    401 
    402 /**
    403  * os_strchr - Locate the first occurrence of a character in string
    404  * @s: String
    405  * @c: Character to search for
    406  * Returns: Pointer to the matched character or %NULL if not found
    407  */
    408 char * os_strchr(const char *s, int c);
    409 
    410 /**
    411  * os_strrchr - Locate the last occurrence of a character in string
    412  * @s: String
    413  * @c: Character to search for
    414  * Returns: Pointer to the matched character or %NULL if not found
    415  */
    416 char * os_strrchr(const char *s, int c);
    417 
    418 /**
    419  * os_strcmp - Compare two strings
    420  * @s1: First string
    421  * @s2: Second string
    422  * Returns: An integer less than, equal to, or greater than zero if s1 is
    423  * found to be less than, to match, or be greatred than s2
    424  */
    425 int os_strcmp(const char *s1, const char *s2);
    426 
    427 /**
    428  * os_strncmp - Compare two strings
    429  * @s1: First string
    430  * @s2: Second string
    431  * @n: Maximum numbers of characters to compare
    432  * Returns: An integer less than, equal to, or greater than zero if s1 is
    433  * found to be less than, to match, or be greater than s2. Only first n
    434  * characters will be compared.
    435  */
    436 int os_strncmp(const char *s1, const char *s2, size_t n);
    437 
    438 /**
    439  * os_strstr - Locate a substring
    440  * @haystack: String (haystack) to search from
    441  * @needle: Needle to search from haystack
    442  * Returns: Pointer to the beginning of the substring or %NULL if not found
    443  */
    444 char * os_strstr(const char *haystack, const char *needle);
    445 
    446 /**
    447  * os_snprintf - Print to a memory buffer
    448  * @str: Memory buffer to print into
    449  * @size: Maximum length of the str buffer
    450  * @format: printf format
    451  * Returns: Number of characters printed (not including trailing '\0').
    452  *
    453  * If the output buffer is truncated, number of characters which would have
    454  * been written is returned. Since some C libraries return -1 in such a case,
    455  * the caller must be prepared on that value, too, to indicate truncation.
    456  *
    457  * Note: Some C library implementations of snprintf() may not guarantee null
    458  * termination in case the output is truncated. The OS wrapper function of
    459  * os_snprintf() should provide this guarantee, i.e., to null terminate the
    460  * output buffer if a C library version of the function is used and if that
    461  * function does not guarantee null termination.
    462  *
    463  * If the target system does not include snprintf(), see, e.g.,
    464  * http://www.ijs.si/software/snprintf/ for an example of a portable
    465  * implementation of snprintf.
    466  */
    467 int os_snprintf(char *str, size_t size, const char *format, ...);
    468 
    469 #else /* OS_NO_C_LIB_DEFINES */
    470 
    471 #ifdef WPA_TRACE
    472 void * os_malloc(size_t size);
    473 void * os_realloc(void *ptr, size_t size);
    474 void os_free(void *ptr);
    475 char * os_strdup(const char *s);
    476 #else /* WPA_TRACE */
    477 #ifndef os_malloc
    478 #define os_malloc(s) malloc((s))
    479 #endif
    480 #ifndef os_realloc
    481 #define os_realloc(p, s) realloc((p), (s))
    482 #endif
    483 #ifndef os_free
    484 #define os_free(p) free((p))
    485 #endif
    486 #ifndef os_strdup
    487 #ifdef _MSC_VER
    488 #define os_strdup(s) _strdup(s)
    489 #else
    490 #define os_strdup(s) strdup(s)
    491 #endif
    492 #endif
    493 #endif /* WPA_TRACE */
    494 
    495 #ifndef os_memcpy
    496 #define os_memcpy(d, s, n) memcpy((d), (s), (n))
    497 #endif
    498 #ifndef os_memmove
    499 #define os_memmove(d, s, n) memmove((d), (s), (n))
    500 #endif
    501 #ifndef os_memset
    502 #define os_memset(s, c, n) memset(s, c, n)
    503 #endif
    504 #ifndef os_memcmp
    505 #define os_memcmp(s1, s2, n) memcmp((s1), (s2), (n))
    506 #endif
    507 
    508 #ifndef os_strlen
    509 #define os_strlen(s) strlen(s)
    510 #endif
    511 #ifndef os_strcasecmp
    512 #ifdef _MSC_VER
    513 #define os_strcasecmp(s1, s2) _stricmp((s1), (s2))
    514 #else
    515 #define os_strcasecmp(s1, s2) strcasecmp((s1), (s2))
    516 #endif
    517 #endif
    518 #ifndef os_strncasecmp
    519 #ifdef _MSC_VER
    520 #define os_strncasecmp(s1, s2, n) _strnicmp((s1), (s2), (n))
    521 #else
    522 #define os_strncasecmp(s1, s2, n) strncasecmp((s1), (s2), (n))
    523 #endif
    524 #endif
    525 #ifndef os_strchr
    526 #define os_strchr(s, c) strchr((s), (c))
    527 #endif
    528 #ifndef os_strcmp
    529 #define os_strcmp(s1, s2) strcmp((s1), (s2))
    530 #endif
    531 #ifndef os_strncmp
    532 #define os_strncmp(s1, s2, n) strncmp((s1), (s2), (n))
    533 #endif
    534 #ifndef os_strrchr
    535 #define os_strrchr(s, c) strrchr((s), (c))
    536 #endif
    537 #ifndef os_strstr
    538 #define os_strstr(h, n) strstr((h), (n))
    539 #endif
    540 
    541 #ifndef os_snprintf
    542 #ifdef _MSC_VER
    543 #define os_snprintf _snprintf
    544 #else
    545 #define os_snprintf snprintf
    546 #endif
    547 #endif
    548 
    549 #endif /* OS_NO_C_LIB_DEFINES */
    550 
    551 
    552 static inline void * os_realloc_array(void *ptr, size_t nmemb, size_t size)
    553 {
    554 	if (size && nmemb > (~(size_t) 0) / size)
    555 		return NULL;
    556 	return os_realloc(ptr, nmemb * size);
    557 }
    558 
    559 /**
    560  * os_remove_in_array - Remove a member from an array by index
    561  * @ptr: Pointer to the array
    562  * @nmemb: Current member count of the array
    563  * @size: The size per member of the array
    564  * @idx: Index of the member to be removed
    565  */
    566 static inline void os_remove_in_array(void *ptr, size_t nmemb, size_t size,
    567 				      size_t idx)
    568 {
    569 	if (idx < nmemb - 1)
    570 		os_memmove(((unsigned char *) ptr) + idx * size,
    571 			   ((unsigned char *) ptr) + (idx + 1) * size,
    572 			   (nmemb - idx - 1) * size);
    573 }
    574 
    575 /**
    576  * os_strlcpy - Copy a string with size bound and NUL-termination
    577  * @dest: Destination
    578  * @src: Source
    579  * @siz: Size of the target buffer
    580  * Returns: Total length of the target string (length of src) (not including
    581  * NUL-termination)
    582  *
    583  * This function matches in behavior with the strlcpy(3) function in OpenBSD.
    584  */
    585 size_t os_strlcpy(char *dest, const char *src, size_t siz);
    586 
    587 /**
    588  * os_memcmp_const - Constant time memory comparison
    589  * @a: First buffer to compare
    590  * @b: Second buffer to compare
    591  * @len: Number of octets to compare
    592  * Returns: 0 if buffers are equal, non-zero if not
    593  *
    594  * This function is meant for comparing passwords or hash values where
    595  * difference in execution time could provide external observer information
    596  * about the location of the difference in the memory buffers. The return value
    597  * does not behave like os_memcmp(), i.e., os_memcmp_const() cannot be used to
    598  * sort items into a defined order. Unlike os_memcmp(), execution time of
    599  * os_memcmp_const() does not depend on the contents of the compared memory
    600  * buffers, but only on the total compared length.
    601  */
    602 int os_memcmp_const(const void *a, const void *b, size_t len);
    603 
    604 /**
    605  * os_exec - Execute an external program
    606  * @program: Path to the program
    607  * @arg: Command line argument string
    608  * @wait_completion: Whether to wait until the program execution completes
    609  * Returns: 0 on success, -1 on error
    610  */
    611 int os_exec(const char *program, const char *arg, int wait_completion);
    612 
    613 
    614 #ifdef OS_REJECT_C_LIB_FUNCTIONS
    615 #define malloc OS_DO_NOT_USE_malloc
    616 #define realloc OS_DO_NOT_USE_realloc
    617 #define free OS_DO_NOT_USE_free
    618 #define memcpy OS_DO_NOT_USE_memcpy
    619 #define memmove OS_DO_NOT_USE_memmove
    620 #define memset OS_DO_NOT_USE_memset
    621 #define memcmp OS_DO_NOT_USE_memcmp
    622 #undef strdup
    623 #define strdup OS_DO_NOT_USE_strdup
    624 #define strlen OS_DO_NOT_USE_strlen
    625 #define strcasecmp OS_DO_NOT_USE_strcasecmp
    626 #define strncasecmp OS_DO_NOT_USE_strncasecmp
    627 #undef strchr
    628 #define strchr OS_DO_NOT_USE_strchr
    629 #undef strcmp
    630 #define strcmp OS_DO_NOT_USE_strcmp
    631 #undef strncmp
    632 #define strncmp OS_DO_NOT_USE_strncmp
    633 #undef strncpy
    634 #define strncpy OS_DO_NOT_USE_strncpy
    635 #define strrchr OS_DO_NOT_USE_strrchr
    636 #define strstr OS_DO_NOT_USE_strstr
    637 #undef snprintf
    638 #define snprintf OS_DO_NOT_USE_snprintf
    639 
    640 #define strcpy OS_DO_NOT_USE_strcpy
    641 #endif /* OS_REJECT_C_LIB_FUNCTIONS */
    642 
    643 #endif /* OS_H */
    644