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      1 /*
      2  * wpa_supplicant/hostapd / common helper functions, etc.
      3  * Copyright (c) 2002-2007, Jouni Malinen <j (at) 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 #include "includes.h"
     16 
     17 #include "common.h"
     18 
     19 
     20 static int hex2num(char c)
     21 {
     22 	if (c >= '0' && c <= '9')
     23 		return c - '0';
     24 	if (c >= 'a' && c <= 'f')
     25 		return c - 'a' + 10;
     26 	if (c >= 'A' && c <= 'F')
     27 		return c - 'A' + 10;
     28 	return -1;
     29 }
     30 
     31 
     32 int hex2byte(const char *hex)
     33 {
     34 	int a, b;
     35 	a = hex2num(*hex++);
     36 	if (a < 0)
     37 		return -1;
     38 	b = hex2num(*hex++);
     39 	if (b < 0)
     40 		return -1;
     41 	return (a << 4) | b;
     42 }
     43 
     44 
     45 /**
     46  * hwaddr_aton - Convert ASCII string to MAC address (colon-delimited format)
     47  * @txt: MAC address as a string (e.g., "00:11:22:33:44:55")
     48  * @addr: Buffer for the MAC address (ETH_ALEN = 6 bytes)
     49  * Returns: 0 on success, -1 on failure (e.g., string not a MAC address)
     50  */
     51 int hwaddr_aton(const char *txt, u8 *addr)
     52 {
     53 	int i;
     54 
     55 	for (i = 0; i < 6; i++) {
     56 		int a, b;
     57 
     58 		a = hex2num(*txt++);
     59 		if (a < 0)
     60 			return -1;
     61 		b = hex2num(*txt++);
     62 		if (b < 0)
     63 			return -1;
     64 		*addr++ = (a << 4) | b;
     65 		if (i < 5 && *txt++ != ':')
     66 			return -1;
     67 	}
     68 
     69 	return 0;
     70 }
     71 
     72 /**
     73  * hwaddr_compact_aton - Convert ASCII string to MAC address (no colon delimitors format)
     74  * @txt: MAC address as a string (e.g., "001122334455")
     75  * @addr: Buffer for the MAC address (ETH_ALEN = 6 bytes)
     76  * Returns: 0 on success, -1 on failure (e.g., string not a MAC address)
     77  */
     78 int hwaddr_compact_aton(const char *txt, u8 *addr)
     79 {
     80 	int i;
     81 
     82 	for (i = 0; i < 6; i++) {
     83 		int a, b;
     84 
     85 		a = hex2num(*txt++);
     86 		if (a < 0)
     87 			return -1;
     88 		b = hex2num(*txt++);
     89 		if (b < 0)
     90 			return -1;
     91 		*addr++ = (a << 4) | b;
     92 	}
     93 
     94 	return 0;
     95 }
     96 
     97 /**
     98  * hwaddr_aton2 - Convert ASCII string to MAC address (in any known format)
     99  * @txt: MAC address as a string (e.g., 00:11:22:33:44:55 or 0011.2233.4455)
    100  * @addr: Buffer for the MAC address (ETH_ALEN = 6 bytes)
    101  * Returns: Characters used (> 0) on success, -1 on failure
    102  */
    103 int hwaddr_aton2(const char *txt, u8 *addr)
    104 {
    105 	int i;
    106 	const char *pos = txt;
    107 
    108 	for (i = 0; i < 6; i++) {
    109 		int a, b;
    110 
    111 		while (*pos == ':' || *pos == '.' || *pos == '-')
    112 			pos++;
    113 
    114 		a = hex2num(*pos++);
    115 		if (a < 0)
    116 			return -1;
    117 		b = hex2num(*pos++);
    118 		if (b < 0)
    119 			return -1;
    120 		*addr++ = (a << 4) | b;
    121 	}
    122 
    123 	return pos - txt;
    124 }
    125 
    126 
    127 /**
    128  * hexstr2bin - Convert ASCII hex string into binary data
    129  * @hex: ASCII hex string (e.g., "01ab")
    130  * @buf: Buffer for the binary data
    131  * @len: Length of the text to convert in bytes (of buf); hex will be double
    132  * this size
    133  * Returns: 0 on success, -1 on failure (invalid hex string)
    134  */
    135 int hexstr2bin(const char *hex, u8 *buf, size_t len)
    136 {
    137 	size_t i;
    138 	int a;
    139 	const char *ipos = hex;
    140 	u8 *opos = buf;
    141 
    142 	for (i = 0; i < len; i++) {
    143 		a = hex2byte(ipos);
    144 		if (a < 0)
    145 			return -1;
    146 		*opos++ = a;
    147 		ipos += 2;
    148 	}
    149 	return 0;
    150 }
    151 
    152 
    153 /**
    154  * inc_byte_array - Increment arbitrary length byte array by one
    155  * @counter: Pointer to byte array
    156  * @len: Length of the counter in bytes
    157  *
    158  * This function increments the last byte of the counter by one and continues
    159  * rolling over to more significant bytes if the byte was incremented from
    160  * 0xff to 0x00.
    161  */
    162 void inc_byte_array(u8 *counter, size_t len)
    163 {
    164 	int pos = len - 1;
    165 	while (pos >= 0) {
    166 		counter[pos]++;
    167 		if (counter[pos] != 0)
    168 			break;
    169 		pos--;
    170 	}
    171 }
    172 
    173 
    174 void wpa_get_ntp_timestamp(u8 *buf)
    175 {
    176 	struct os_time now;
    177 	u32 sec, usec;
    178 	be32 tmp;
    179 
    180 	/* 64-bit NTP timestamp (time from 1900-01-01 00:00:00) */
    181 	os_get_time(&now);
    182 	sec = now.sec + 2208988800U; /* Epoch to 1900 */
    183 	/* Estimate 2^32/10^6 = 4295 - 1/32 - 1/512 */
    184 	usec = now.usec;
    185 	usec = 4295 * usec - (usec >> 5) - (usec >> 9);
    186 	tmp = host_to_be32(sec);
    187 	os_memcpy(buf, (u8 *) &tmp, 4);
    188 	tmp = host_to_be32(usec);
    189 	os_memcpy(buf + 4, (u8 *) &tmp, 4);
    190 }
    191 
    192 
    193 static inline int _wpa_snprintf_hex(char *buf, size_t buf_size, const u8 *data,
    194 				    size_t len, int uppercase)
    195 {
    196 	size_t i;
    197 	char *pos = buf, *end = buf + buf_size;
    198 	int ret;
    199 	if (buf_size == 0)
    200 		return 0;
    201 	for (i = 0; i < len; i++) {
    202 		ret = os_snprintf(pos, end - pos, uppercase ? "%02X" : "%02x",
    203 				  data[i]);
    204 		if (ret < 0 || ret >= end - pos) {
    205 			end[-1] = '\0';
    206 			return pos - buf;
    207 		}
    208 		pos += ret;
    209 	}
    210 	end[-1] = '\0';
    211 	return pos - buf;
    212 }
    213 
    214 /**
    215  * wpa_snprintf_hex - Print data as a hex string into a buffer
    216  * @buf: Memory area to use as the output buffer
    217  * @buf_size: Maximum buffer size in bytes (should be at least 2 * len + 1)
    218  * @data: Data to be printed
    219  * @len: Length of data in bytes
    220  * Returns: Number of bytes written
    221  */
    222 int wpa_snprintf_hex(char *buf, size_t buf_size, const u8 *data, size_t len)
    223 {
    224 	return _wpa_snprintf_hex(buf, buf_size, data, len, 0);
    225 }
    226 
    227 
    228 /**
    229  * wpa_snprintf_hex_uppercase - Print data as a upper case hex string into buf
    230  * @buf: Memory area to use as the output buffer
    231  * @buf_size: Maximum buffer size in bytes (should be at least 2 * len + 1)
    232  * @data: Data to be printed
    233  * @len: Length of data in bytes
    234  * Returns: Number of bytes written
    235  */
    236 int wpa_snprintf_hex_uppercase(char *buf, size_t buf_size, const u8 *data,
    237 			       size_t len)
    238 {
    239 	return _wpa_snprintf_hex(buf, buf_size, data, len, 1);
    240 }
    241 
    242 
    243 #ifdef CONFIG_ANSI_C_EXTRA
    244 
    245 #ifdef _WIN32_WCE
    246 void perror(const char *s)
    247 {
    248 	wpa_printf(MSG_ERROR, "%s: GetLastError: %d",
    249 		   s, (int) GetLastError());
    250 }
    251 #endif /* _WIN32_WCE */
    252 
    253 
    254 int optind = 1;
    255 int optopt;
    256 char *optarg;
    257 
    258 int getopt(int argc, char *const argv[], const char *optstring)
    259 {
    260 	static int optchr = 1;
    261 	char *cp;
    262 
    263 	if (optchr == 1) {
    264 		if (optind >= argc) {
    265 			/* all arguments processed */
    266 			return EOF;
    267 		}
    268 
    269 		if (argv[optind][0] != '-' || argv[optind][1] == '\0') {
    270 			/* no option characters */
    271 			return EOF;
    272 		}
    273 	}
    274 
    275 	if (os_strcmp(argv[optind], "--") == 0) {
    276 		/* no more options */
    277 		optind++;
    278 		return EOF;
    279 	}
    280 
    281 	optopt = argv[optind][optchr];
    282 	cp = os_strchr(optstring, optopt);
    283 	if (cp == NULL || optopt == ':') {
    284 		if (argv[optind][++optchr] == '\0') {
    285 			optchr = 1;
    286 			optind++;
    287 		}
    288 		return '?';
    289 	}
    290 
    291 	if (cp[1] == ':') {
    292 		/* Argument required */
    293 		optchr = 1;
    294 		if (argv[optind][optchr + 1]) {
    295 			/* No space between option and argument */
    296 			optarg = &argv[optind++][optchr + 1];
    297 		} else if (++optind >= argc) {
    298 			/* option requires an argument */
    299 			return '?';
    300 		} else {
    301 			/* Argument in the next argv */
    302 			optarg = argv[optind++];
    303 		}
    304 	} else {
    305 		/* No argument */
    306 		if (argv[optind][++optchr] == '\0') {
    307 			optchr = 1;
    308 			optind++;
    309 		}
    310 		optarg = NULL;
    311 	}
    312 	return *cp;
    313 }
    314 #endif /* CONFIG_ANSI_C_EXTRA */
    315 
    316 
    317 #ifdef CONFIG_NATIVE_WINDOWS
    318 /**
    319  * wpa_unicode2ascii_inplace - Convert unicode string into ASCII
    320  * @str: Pointer to string to convert
    321  *
    322  * This function converts a unicode string to ASCII using the same
    323  * buffer for output. If UNICODE is not set, the buffer is not
    324  * modified.
    325  */
    326 void wpa_unicode2ascii_inplace(TCHAR *str)
    327 {
    328 #ifdef UNICODE
    329 	char *dst = (char *) str;
    330 	while (*str)
    331 		*dst++ = (char) *str++;
    332 	*dst = '\0';
    333 #endif /* UNICODE */
    334 }
    335 
    336 
    337 TCHAR * wpa_strdup_tchar(const char *str)
    338 {
    339 #ifdef UNICODE
    340 	TCHAR *buf;
    341 	buf = os_malloc((strlen(str) + 1) * sizeof(TCHAR));
    342 	if (buf == NULL)
    343 		return NULL;
    344 	wsprintf(buf, L"%S", str);
    345 	return buf;
    346 #else /* UNICODE */
    347 	return os_strdup(str);
    348 #endif /* UNICODE */
    349 }
    350 #endif /* CONFIG_NATIVE_WINDOWS */
    351 
    352 
    353 /**
    354  * wpa_ssid_txt - Convert SSID to a printable string
    355  * @ssid: SSID (32-octet string)
    356  * @ssid_len: Length of ssid in octets
    357  * Returns: Pointer to a printable string
    358  *
    359  * This function can be used to convert SSIDs into printable form. In most
    360  * cases, SSIDs do not use unprintable characters, but IEEE 802.11 standard
    361  * does not limit the used character set, so anything could be used in an SSID.
    362  *
    363  * This function uses a static buffer, so only one call can be used at the
    364  * time, i.e., this is not re-entrant and the returned buffer must be used
    365  * before calling this again.
    366  */
    367 const char * wpa_ssid_txt(const u8 *ssid, size_t ssid_len)
    368 {
    369 	static char ssid_txt[33];
    370 	char *pos;
    371 
    372 	if (ssid_len > 32)
    373 		ssid_len = 32;
    374 	os_memcpy(ssid_txt, ssid, ssid_len);
    375 	ssid_txt[ssid_len] = '\0';
    376 	for (pos = ssid_txt; *pos != '\0'; pos++) {
    377 #ifndef WPA_UNICODE_SSID
    378 		if ((u8) *pos < 32 || (u8) *pos >= 127)
    379 			*pos = '_';
    380 #endif
    381 	}
    382 	return ssid_txt;
    383 }
    384 
    385 
    386 void * __hide_aliasing_typecast(void *foo)
    387 {
    388 	return foo;
    389 }
    390