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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 static 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
     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 /**
     74  * hexstr2bin - Convert ASCII hex string into binary data
     75  * @hex: ASCII hex string (e.g., "01ab")
     76  * @buf: Buffer for the binary data
     77  * @len: Length of the text to convert in bytes (of buf); hex will be double
     78  * this size
     79  * Returns: 0 on success, -1 on failure (invalid hex string)
     80  */
     81 int hexstr2bin(const char *hex, u8 *buf, size_t len)
     82 {
     83 	size_t i;
     84 	int a;
     85 	const char *ipos = hex;
     86 	u8 *opos = buf;
     87 
     88 	for (i = 0; i < len; i++) {
     89 		a = hex2byte(ipos);
     90 		if (a < 0)
     91 			return -1;
     92 		*opos++ = a;
     93 		ipos += 2;
     94 	}
     95 	return 0;
     96 }
     97 
     98 
     99 /**
    100  * inc_byte_array - Increment arbitrary length byte array by one
    101  * @counter: Pointer to byte array
    102  * @len: Length of the counter in bytes
    103  *
    104  * This function increments the last byte of the counter by one and continues
    105  * rolling over to more significant bytes if the byte was incremented from
    106  * 0xff to 0x00.
    107  */
    108 void inc_byte_array(u8 *counter, size_t len)
    109 {
    110 	int pos = len - 1;
    111 	while (pos >= 0) {
    112 		counter[pos]++;
    113 		if (counter[pos] != 0)
    114 			break;
    115 		pos--;
    116 	}
    117 }
    118 
    119 
    120 void wpa_get_ntp_timestamp(u8 *buf)
    121 {
    122 	struct os_time now;
    123 	u32 sec, usec;
    124 	be32 tmp;
    125 
    126 	/* 64-bit NTP timestamp (time from 1900-01-01 00:00:00) */
    127 	os_get_time(&now);
    128 	sec = now.sec + 2208988800U; /* Epoch to 1900 */
    129 	/* Estimate 2^32/10^6 = 4295 - 1/32 - 1/512 */
    130 	usec = now.usec;
    131 	usec = 4295 * usec - (usec >> 5) - (usec >> 9);
    132 	tmp = host_to_be32(sec);
    133 	os_memcpy(buf, (u8 *) &tmp, 4);
    134 	tmp = host_to_be32(usec);
    135 	os_memcpy(buf + 4, (u8 *) &tmp, 4);
    136 }
    137 
    138 
    139 static inline int _wpa_snprintf_hex(char *buf, size_t buf_size, const u8 *data,
    140 				    size_t len, int uppercase)
    141 {
    142 	size_t i;
    143 	char *pos = buf, *end = buf + buf_size;
    144 	int ret;
    145 	if (buf_size == 0)
    146 		return 0;
    147 	for (i = 0; i < len; i++) {
    148 		ret = os_snprintf(pos, end - pos, uppercase ? "%02X" : "%02x",
    149 				  data[i]);
    150 		if (ret < 0 || ret >= end - pos) {
    151 			end[-1] = '\0';
    152 			return pos - buf;
    153 		}
    154 		pos += ret;
    155 	}
    156 	end[-1] = '\0';
    157 	return pos - buf;
    158 }
    159 
    160 /**
    161  * wpa_snprintf_hex - Print data as a hex string into a buffer
    162  * @buf: Memory area to use as the output buffer
    163  * @buf_size: Maximum buffer size in bytes (should be at least 2 * len + 1)
    164  * @data: Data to be printed
    165  * @len: Length of data in bytes
    166  * Returns: Number of bytes written
    167  */
    168 int wpa_snprintf_hex(char *buf, size_t buf_size, const u8 *data, size_t len)
    169 {
    170 	return _wpa_snprintf_hex(buf, buf_size, data, len, 0);
    171 }
    172 
    173 
    174 /**
    175  * wpa_snprintf_hex_uppercase - Print data as a upper case hex string into buf
    176  * @buf: Memory area to use as the output buffer
    177  * @buf_size: Maximum buffer size in bytes (should be at least 2 * len + 1)
    178  * @data: Data to be printed
    179  * @len: Length of data in bytes
    180  * Returns: Number of bytes written
    181  */
    182 int wpa_snprintf_hex_uppercase(char *buf, size_t buf_size, const u8 *data,
    183 			       size_t len)
    184 {
    185 	return _wpa_snprintf_hex(buf, buf_size, data, len, 1);
    186 }
    187 
    188 
    189 #ifdef CONFIG_ANSI_C_EXTRA
    190 
    191 #ifdef _WIN32_WCE
    192 void perror(const char *s)
    193 {
    194 	wpa_printf(MSG_ERROR, "%s: GetLastError: %d",
    195 		   s, (int) GetLastError());
    196 }
    197 #endif /* _WIN32_WCE */
    198 
    199 
    200 int optind = 1;
    201 int optopt;
    202 char *optarg;
    203 
    204 int getopt(int argc, char *const argv[], const char *optstring)
    205 {
    206 	static int optchr = 1;
    207 	char *cp;
    208 
    209 	if (optchr == 1) {
    210 		if (optind >= argc) {
    211 			/* all arguments processed */
    212 			return EOF;
    213 		}
    214 
    215 		if (argv[optind][0] != '-' || argv[optind][1] == '\0') {
    216 			/* no option characters */
    217 			return EOF;
    218 		}
    219 	}
    220 
    221 	if (os_strcmp(argv[optind], "--") == 0) {
    222 		/* no more options */
    223 		optind++;
    224 		return EOF;
    225 	}
    226 
    227 	optopt = argv[optind][optchr];
    228 	cp = os_strchr(optstring, optopt);
    229 	if (cp == NULL || optopt == ':') {
    230 		if (argv[optind][++optchr] == '\0') {
    231 			optchr = 1;
    232 			optind++;
    233 		}
    234 		return '?';
    235 	}
    236 
    237 	if (cp[1] == ':') {
    238 		/* Argument required */
    239 		optchr = 1;
    240 		if (argv[optind][optchr + 1]) {
    241 			/* No space between option and argument */
    242 			optarg = &argv[optind++][optchr + 1];
    243 		} else if (++optind >= argc) {
    244 			/* option requires an argument */
    245 			return '?';
    246 		} else {
    247 			/* Argument in the next argv */
    248 			optarg = argv[optind++];
    249 		}
    250 	} else {
    251 		/* No argument */
    252 		if (argv[optind][++optchr] == '\0') {
    253 			optchr = 1;
    254 			optind++;
    255 		}
    256 		optarg = NULL;
    257 	}
    258 	return *cp;
    259 }
    260 #endif /* CONFIG_ANSI_C_EXTRA */
    261 
    262 
    263 #ifdef CONFIG_NATIVE_WINDOWS
    264 /**
    265  * wpa_unicode2ascii_inplace - Convert unicode string into ASCII
    266  * @str: Pointer to string to convert
    267  *
    268  * This function converts a unicode string to ASCII using the same
    269  * buffer for output. If UNICODE is not set, the buffer is not
    270  * modified.
    271  */
    272 void wpa_unicode2ascii_inplace(TCHAR *str)
    273 {
    274 #ifdef UNICODE
    275 	char *dst = (char *) str;
    276 	while (*str)
    277 		*dst++ = (char) *str++;
    278 	*dst = '\0';
    279 #endif /* UNICODE */
    280 }
    281 
    282 
    283 TCHAR * wpa_strdup_tchar(const char *str)
    284 {
    285 #ifdef UNICODE
    286 	TCHAR *buf;
    287 	buf = os_malloc((strlen(str) + 1) * sizeof(TCHAR));
    288 	if (buf == NULL)
    289 		return NULL;
    290 	wsprintf(buf, L"%S", str);
    291 	return buf;
    292 #else /* UNICODE */
    293 	return os_strdup(str);
    294 #endif /* UNICODE */
    295 }
    296 #endif /* CONFIG_NATIVE_WINDOWS */
    297 
    298 
    299 /**
    300  * wpa_ssid_txt - Convert SSID to a printable string
    301  * @ssid: SSID (32-octet string)
    302  * @ssid_len: Length of ssid in octets
    303  * Returns: Pointer to a printable string
    304  *
    305  * This function can be used to convert SSIDs into printable form. In most
    306  * cases, SSIDs do not use unprintable characters, but IEEE 802.11 standard
    307  * does not limit the used character set, so anything could be used in an SSID.
    308  *
    309  * This function uses a static buffer, so only one call can be used at the
    310  * time, i.e., this is not re-entrant and the returned buffer must be used
    311  * before calling this again.
    312  */
    313 const char * wpa_ssid_txt(const u8 *ssid, size_t ssid_len)
    314 {
    315 	static char ssid_txt[33];
    316 	char *pos;
    317 
    318 	if (ssid_len > 32)
    319 		ssid_len = 32;
    320 	os_memcpy(ssid_txt, ssid, ssid_len);
    321 	ssid_txt[ssid_len] = '\0';
    322 	for (pos = ssid_txt; *pos != '\0'; pos++) {
    323 #ifndef WPA_UNICODE_SSID
    324 		if ((u8) *pos < 32 || (u8) *pos >= 127)
    325 			*pos = '_';
    326 #endif
    327 	}
    328 	return ssid_txt;
    329 }
    330 
    331 
    332 void * __hide_aliasing_typecast(void *foo)
    333 {
    334 	return foo;
    335 }
    336