common.c

hostapd源代码

/*
 * wpa_supplicant/hostapd / common helper functions, etc.
 * Copyright (c) 2002-2006, 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.
 */

#include "includes.h"

#include "common.h"


int wpa_debug_level = MSG_INFO;
int wpa_debug_show_keys = 0;
int wpa_debug_timestamp = 0;


static int hex2num(char c)
{
	if (c >= '0' && c <= '9')
		return c - '0';
	if (c >= 'a' && c <= 'f')
		return c - 'a' + 10;
	if (c >= 'A' && c <= 'F')
		return c - 'A' + 10;
	return -1;
}


static int hex2byte(const char *hex)
{
	int a, b;
	a = hex2num(*hex++);
	if (a < 0)
		return -1;
	b = hex2num(*hex++);
	if (b < 0)
		return -1;
	return (a << 4) | b;
}


/**
 * hwaddr_aton - Convert ASCII string to MAC address
 * @txt: MAC address as a string (e.g., "00:11:22:33:44:55")
 * @addr: Buffer for the MAC address (ETH_ALEN = 6 bytes)
 * Returns: 0 on success, -1 on failure (e.g., string not a MAC address)
 */
int hwaddr_aton(const char *txt, u8 *addr)
{
	int i;

	for (i = 0; i < 6; i++) {
		int a, b;

		a = hex2num(*txt++);
		if (a < 0)
			return -1;
		b = hex2num(*txt++);
		if (b < 0)
			return -1;
		*addr++ = (a << 4) | b;
		if (i < 5 && *txt++ != ':')
			return -1;
	}

	return 0;
}


/**
 * hexstr2bin - Convert ASCII hex string into binary data
 * @hex: ASCII hex string (e.g., "01ab")
 * @buf: Buffer for the binary data
 * @len: Length of the text to convert in bytes (of buf); hex will be double
 * this size
 * Returns: 0 on success, -1 on failure (invalid hex string)
 */
int hexstr2bin(const char *hex, u8 *buf, size_t len)
{
	size_t i;
	int a;
	const char *ipos = hex;
	u8 *opos = buf;

	for (i = 0; i < len; i++) {
		a = hex2byte(ipos);
		if (a < 0)
			return -1;
		*opos++ = a;
		ipos += 2;
	}
	return 0;
}


/**
 * inc_byte_array - Increment arbitrary length byte array by one
 * @counter: Pointer to byte array
 * @len: Length of the counter in bytes
 *
 * This function increments the last byte of the counter by one and continues
 * rolling over to more significant bytes if the byte was incremented from
 * 0xff to 0x00.
 */
void inc_byte_array(u8 *counter, size_t len)
{
	int pos = len - 1;
	while (pos >= 0) {
		counter[pos]++;
		if (counter[pos] != 0)
			break;
		pos--;
	}
}


void wpa_get_ntp_timestamp(u8 *buf)
{
	struct os_time now;
	u32 sec, usec;

	/* 64-bit NTP timestamp (time from 1900-01-01 00:00:00) */
	os_get_time(&now);
	sec = host_to_be32(now.sec + 2208988800U); /* Epoch to 1900 */
	/* Estimate 2^32/10^6 = 4295 - 1/32 - 1/512 */
	usec = now.usec;
	usec = host_to_be32(4295 * usec - (usec >> 5) - (usec >> 9));
	memcpy(buf, (u8 *) &sec, 4);
	memcpy(buf + 4, (u8 *) &usec, 4);
}



#ifndef CONFIG_NO_STDOUT_DEBUG

void wpa_debug_print_timestamp(void)
{
	struct os_time tv;

	if (!wpa_debug_timestamp)
		return;

	os_get_time(&tv);
	printf("%ld.%06u: ", (long) tv.sec, (unsigned int) tv.usec);
}


/**
 * wpa_printf - conditional printf
 * @level: priority level (MSG_*) of the message
 * @fmt: printf format string, followed by optional arguments
 *
 * This function is used to print conditional debugging and error messages. The
 * output may be directed to stdout, stderr, and/or syslog based on
 * configuration.
 *
 * Note: New line '\n' is added to the end of the text when printing to stdout.
 */
void wpa_printf(int level, char *fmt, ...)
{
	va_list ap;

	va_start(ap, fmt);
	if (level >= wpa_debug_level) {
		wpa_debug_print_timestamp();
		vprintf(fmt, ap);
		printf("\n");
	}
	va_end(ap);
}


static void _wpa_hexdump(int level, const char *title, const u8 *buf,
			 size_t len, int show)
{
	size_t i;
	if (level < wpa_debug_level)
		return;
	wpa_debug_print_timestamp();
	printf("%s - hexdump(len=%lu):", title, (unsigned long) len);
	if (buf == NULL) {
		printf(" [NULL]");
	} else if (show) {
		for (i = 0; i < len; i++)
			printf(" %02x", buf[i]);
	} else {
		printf(" [REMOVED]");
	}
	printf("\n");
}

void wpa_hexdump(int level, const char *title, const u8 *buf, size_t len)
{
	_wpa_hexdump(level, title, buf, len, 1);
}


void wpa_hexdump_key(int level, const char *title, const u8 *buf, size_t len)
{
	_wpa_hexdump(level, title, buf, len, wpa_debug_show_keys);
}


static void _wpa_hexdump_ascii(int level, const char *title, const u8 *buf,
			       size_t len, int show)
{
	size_t i, llen;
	const u8 *pos = buf;
	const size_t line_len = 16;

	if (level < wpa_debug_level)
		return;
	wpa_debug_print_timestamp();
	if (!show) {
		printf("%s - hexdump_ascii(len=%lu): [REMOVED]\n",
		       title, (unsigned long) len);
		return;
	}
	if (buf == NULL) {
		printf("%s - hexdump_ascii(len=%lu): [NULL]\n",
		       title, (unsigned long) len);
		return;
	}
	printf("%s - hexdump_ascii(len=%lu):\n", title, (unsigned long) len);
	while (len) {
		llen = len > line_len ? line_len : len;
		printf("    ");
		for (i = 0; i < llen; i++)
			printf(" %02x", pos[i]);
		for (i = llen; i < line_len; i++)
			printf("   ");
		printf("   ");
		for (i = 0; i < llen; i++) {
			if (isprint(pos[i]))
				printf("%c", pos[i]);
			else
				printf("_");
		}
		for (i = llen; i < line_len; i++)
			printf(" ");
		printf("\n");
		pos += llen;
		len -= llen;
	}
}


void wpa_hexdump_ascii(int level, const char *title, const u8 *buf, size_t len)
{
	_wpa_hexdump_ascii(level, title, buf, len, 1);
}


void wpa_hexdump_ascii_key(int level, const char *title, const u8 *buf,
			   size_t len)
{
	_wpa_hexdump_ascii(level, title, buf, len, wpa_debug_show_keys);
}

#endif /* CONFIG_NO_STDOUT_DEBUG */


static inline int _wpa_snprintf_hex(char *buf, size_t buf_size, const u8 *data,
				    size_t len, int uppercase)
{
	size_t i;
	char *pos = buf, *end = buf + buf_size;
	for (i = 0; i < len; i++) {
		pos += snprintf(pos, end - pos, uppercase ? "%02X" : "%02x",
				data[i]);
	}
	return pos - buf;
}

/**
 * wpa_snprintf_hex - Print data as a hex string into a buffer
 * @buf: Memory area to use as the output buffer
 * @buf_size: Maximum buffer size in bytes (should be at least 2 * len + 1)
 * @data: Data to be printed
 * @len: Length of data in bytes
 */
int wpa_snprintf_hex(char *buf, size_t buf_size, const u8 *data, size_t len)
{
	return _wpa_snprintf_hex(buf, buf_size, data, len, 0);
}


/**
 * wpa_snprintf_hex_uppercase - Print data as a upper case hex string into buf
 * @buf: Memory area to use as the output buffer
 * @buf_size: Maximum buffer size in bytes (should be at least 2 * len + 1)
 * @data: Data to be printed
 * @len: Length of data in bytes
 */
int wpa_snprintf_hex_uppercase(char *buf, size_t buf_size, const u8 *data,
			       size_t len)
{
	return _wpa_snprintf_hex(buf, buf_size, data, len, 1);
}


#ifdef CONFIG_ANSI_C_EXTRA
/*
 * Extremely simple (and likely inefficient) example implementation of some C
 * library functions
 */

#ifndef _MSC_VER
#undef memcpy
void *memcpy(void *dest, const void *src, size_t n)
{
	unsigned char *d = dest;
	const unsigned char *s = src;
	while (n--)
		*d++ = *s++;
	return dest;
}
#endif


#undef memmove
void *memmove(void *dest, const void *src, size_t n)
{
	if (dest < src)
		memcpy(dest, src, n);
	else {
		/* overlapping areas */
		unsigned char *d = (unsigned char *) dest + n;
		const unsigned char *s = (const unsigned char *) src + n;
		while (n--)
			*--d = *--s;
	}
	return dest;
}


#ifndef _MSC_VER
#undef memset
void *memset(void *s, int c, size_t n)
{
	unsigned char *p = s;
	while (n--)
		*p++ = c;
	return s;
}
#endif


#ifndef _MSC_VER
#undef memcmp
int memcmp(const void *s1, const void *s2, size_t n)
{
	const unsigned char *p1 = s1, *p2 = s2;

	if (n == 0)
		return 0;

	while (*p1 == *p2) {
		p1++;
		p2++;
		n--;
		if (n == 0)
			return 0;
	}

	return *p1 - *p2;
}
#endif


#undef strchr
char *strchr(const char *s, int c)
{
	while (*s) {
		if (*s == c)
			return (char *) s;
		s++;
	}
	return NULL;
}


#undef strrchr
char *strrchr(const char *s, int c)
{
	const char *p = s;
	while (*p)
		p++;
	p--;
	while (p >= s) {
		if (*p == c)
			return (char *) p;
		p--;
	}
	return NULL;
}


#ifndef _MSC_VER
#undef strcmp
int strcmp(const char *s1, const char *s2)
{
	while (*s1 == *s2) {
		if (*s1 == '\0')
			break;
		s1++;
		s2++;
	}

	return *s1 - *s2;
}
#endif


#undef strncmp
int strncmp(const char *s1, const char *s2, size_t n)
{
	if (n == 0)
		return 0;

	while (*s1 == *s2) {
		if (*s1 == '\0')
			break;
		s1++;
		s2++;
		n--;
		if (n == 0)
			return 0;
	}

	return *s1 - *s2;
}


#ifndef _MSC_VER
#undef strlen
size_t strlen(const char *s)
{
	const char *p = s;
	while (*p)
		p++;
	return p - s;
}
#endif


#undef strncpy
char *strncpy(char *dest, const char *src, size_t n)
{
	char *d = dest;

	while (n--) {
		*d = *src;
		if (*src == '\0')
			break;
		d++;
		src++;
	}

	return dest;
}


#undef strstr
char *strstr(const char *haystack, const char *needle)
{
	size_t len = strlen(needle);
	while (*haystack) {
		if (strncmp(haystack, needle, len) == 0)
			return (char *) haystack;
		haystack++;
	}

	return NULL;
}


#undef strdup
char * strdup(const char *s)
{
	char *res;
	size_t len;
	if (s == NULL)
		return NULL;
	len = strlen(s);
	res = malloc(len + 1);
	if (res)
		memcpy(res, s, len + 1);
	return res;
}


#ifdef _WIN32_WCE
void perror(const char *s)
{
	wpa_printf(MSG_ERROR, "%s: GetLastError: %d",
		   s, (int) GetLastError());
}
#endif /* _WIN32_WCE */


int optind = 1;
int optopt;
char *optarg;

int getopt(int argc, char *const argv[], const char *optstring)
{
	static int optchr = 1;
	char *cp;

	if (optchr == 1) {
		if (optind >= argc) {
			/* all arguments processed */
			return EOF;
		}

		if (argv[optind][0] != '-' || argv[optind][1] == '\0') {
			/* no option characters */
			return EOF;
		}
	}

	if (strcmp(argv[optind], "--") == 0) {
		/* no more options */
		optind++;
		return EOF;
	}

	optopt = argv[optind][optchr];
	cp = strchr(optstring, optopt);
	if (cp == NULL || optopt == ':') {
		if (argv[optind][++optchr] == '\0') {
			optchr = 1;
			optind++;
		}
		return '?';
	}

	if (cp[1] == ':') {
		/* Argument required */
		optchr = 1;
		if (argv[optind][optchr + 1]) {
			/* No space between option and argument */
			optarg = &argv[optind++][optchr + 1];
		} else if (++optind >= argc) {
			/* option requires an argument */
			return '?';
		} else {
			/* Argument in the next argv */
			optarg = argv[optind++];
		}
	} else {
		/* No argument */
		if (argv[optind][++optchr] == '\0') {
			optchr = 1;
			optind++;
		}
		optarg = NULL;
	}
	return *cp;
}
#endif /* CONFIG_ANSI_C_EXTRA */


/**
 * wpa_zalloc - Allocate and zero memory
 * @size: Number of bytes to allocate
 * Returns: Pointer to allocated and zeroed memory or %NULL on failure
 */
void *wpa_zalloc(size_t size)
{
	void *b = malloc(size);
	if (b)
		memset(b, 0, size);
	return b;
}