os.h

来自「hostapd源代码」· C头文件 代码 · 共 119 行

/*
 * wpa_supplicant/hostapd / OS specific functions
 * Copyright (c) 2005, Jouni Malinen <[e-mail]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Alternatively, this software may be distributed under the terms of BSD
 * license.
 *
 * See README and COPYING for more details.
 */

#ifndef OS_H
#define OS_H

typedef long os_time_t;

/**
 * os_sleep - Sleep (sec, usec)
 * @sec: Number of seconds to sleep
 * @usec: Number of microseconds to sleep
 */
void os_sleep(os_time_t sec, os_time_t usec);

struct os_time {
	os_time_t sec;
	os_time_t usec;
};

/**
 * os_get_time - Get current time (sec, usec)
 * @t: Pointer to buffer for the time
 * Returns: 0 on success, -1 on failure
 */
int os_get_time(struct os_time *t);


/* Helper macros for handling struct os_time */

#define os_time_before(a, b) \
	((a)->sec < (b)->sec || \
	 ((a)->sec == (b)->sec && (a)->usec < (b)->usec))

#define os_time_sub(a, b, res) do { \
	(res)->sec = (a)->sec - (b)->sec; \
	(res)->usec = (a)->usec - (b)->usec; \
	if ((res)->usec < 0) { \
		(res)->sec--; \
		(res)->usec += 1000000; \
	} \
} while (0)


/**
 * os_daemonize - Run in the background (detach from the controlling terminal)
 * @pid_file: File name to write the process ID to or %NULL to skip this
 * Returns: 0 on success, -1 on failure
 */
int os_daemonize(const char *pid_file);

/**
 * os_daemonize_terminate - Stop running in the background (remove pid file)
 * @pid_file: File name to write the process ID to or %NULL to skip this
 */
void os_daemonize_terminate(const char *pid_file);

/**
 * os_get_random - Get cryptographically strong pseudo random data
 * @buf: Buffer for pseudo random data
 * @len: Length of the buffer
 * Returns: 0 on success, -1 on failure
 */
int os_get_random(unsigned char *buf, size_t len);

/**
 * os_random - Get pseudo random value (not necessarily very strong)
 * Returns: Pseudo random value
 */
unsigned long os_random(void);

/**
 * os_rel2abs_path - Get an absolute path for a file
 * @rel_path: Relative path to a file
 * Returns: Absolute path for the file or %NULL on failure
 *
 * This function tries to convert a relative path of a file to an absolute path
 * in order for the file to be found even if current working directory has
 * changed. The returned value is allocated and caller is responsible for
 * freeing it. It is acceptable to just return the same path in an allocated
 * buffer, e.g., return strdup(rel_path). This function is only used to find
 * configuration files when os_daemonize() may have changed the current working
 * directory and relative path would be pointing to a different location.
 */
char * os_rel2abs_path(const char *rel_path);

/**
 * os_program_init - Program initialization (called at start)
 * Returns: 0 on success, -1 on failure
 *
 * This function is called when a programs starts. If there are any OS specific
 * processing that is needed, it can be placed here. It is also acceptable to
 * just return 0 if not special processing is needed.
 */
int os_program_init(void);

/**
 * os_program_deinit - Program deinitialization (called just before exit)
 *
 * This function is called just before a program exists. If there are any OS
 * specific processing, e.g., freeing resourced allocated in os_program_init(),
 * it should be done here. It is also acceptable for this function to do
 * nothing.
 */
void os_program_deinit(void);

#endif /* OS_H */