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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 software may be distributed under the terms of the BSD license.
      6  * See README for more details.
      7  */
      8 
      9 #include "includes.h"
     10 
     11 #include "common.h"
     12 
     13 
     14 static int hex2num(char c)
     15 {
     16 	if (c >= '0' && c <= '9')
     17 		return c - '0';
     18 	if (c >= 'a' && c <= 'f')
     19 		return c - 'a' + 10;
     20 	if (c >= 'A' && c <= 'F')
     21 		return c - 'A' + 10;
     22 	return -1;
     23 }
     24 
     25 
     26 int hex2byte(const char *hex)
     27 {
     28 	int a, b;
     29 	a = hex2num(*hex++);
     30 	if (a < 0)
     31 		return -1;
     32 	b = hex2num(*hex++);
     33 	if (b < 0)
     34 		return -1;
     35 	return (a << 4) | b;
     36 }
     37 
     38 
     39 /**
     40  * hwaddr_aton - Convert ASCII string to MAC address (colon-delimited format)
     41  * @txt: MAC address as a string (e.g., "00:11:22:33:44:55")
     42  * @addr: Buffer for the MAC address (ETH_ALEN = 6 bytes)
     43  * Returns: 0 on success, -1 on failure (e.g., string not a MAC address)
     44  */
     45 int hwaddr_aton(const char *txt, u8 *addr)
     46 {
     47 	int i;
     48 
     49 	for (i = 0; i < 6; i++) {
     50 		int a, b;
     51 
     52 		a = hex2num(*txt++);
     53 		if (a < 0)
     54 			return -1;
     55 		b = hex2num(*txt++);
     56 		if (b < 0)
     57 			return -1;
     58 		*addr++ = (a << 4) | b;
     59 		if (i < 5 && *txt++ != ':')
     60 			return -1;
     61 	}
     62 
     63 	return 0;
     64 }
     65 
     66 /**
     67  * hwaddr_compact_aton - Convert ASCII string to MAC address (no colon delimitors format)
     68  * @txt: MAC address as a string (e.g., "001122334455")
     69  * @addr: Buffer for the MAC address (ETH_ALEN = 6 bytes)
     70  * Returns: 0 on success, -1 on failure (e.g., string not a MAC address)
     71  */
     72 int hwaddr_compact_aton(const char *txt, u8 *addr)
     73 {
     74 	int i;
     75 
     76 	for (i = 0; i < 6; i++) {
     77 		int a, b;
     78 
     79 		a = hex2num(*txt++);
     80 		if (a < 0)
     81 			return -1;
     82 		b = hex2num(*txt++);
     83 		if (b < 0)
     84 			return -1;
     85 		*addr++ = (a << 4) | b;
     86 	}
     87 
     88 	return 0;
     89 }
     90 
     91 /**
     92  * hwaddr_aton2 - Convert ASCII string to MAC address (in any known format)
     93  * @txt: MAC address as a string (e.g., 00:11:22:33:44:55 or 0011.2233.4455)
     94  * @addr: Buffer for the MAC address (ETH_ALEN = 6 bytes)
     95  * Returns: Characters used (> 0) on success, -1 on failure
     96  */
     97 int hwaddr_aton2(const char *txt, u8 *addr)
     98 {
     99 	int i;
    100 	const char *pos = txt;
    101 
    102 	for (i = 0; i < 6; i++) {
    103 		int a, b;
    104 
    105 		while (*pos == ':' || *pos == '.' || *pos == '-')
    106 			pos++;
    107 
    108 		a = hex2num(*pos++);
    109 		if (a < 0)
    110 			return -1;
    111 		b = hex2num(*pos++);
    112 		if (b < 0)
    113 			return -1;
    114 		*addr++ = (a << 4) | b;
    115 	}
    116 
    117 	return pos - txt;
    118 }
    119 
    120 
    121 /**
    122  * hexstr2bin - Convert ASCII hex string into binary data
    123  * @hex: ASCII hex string (e.g., "01ab")
    124  * @buf: Buffer for the binary data
    125  * @len: Length of the text to convert in bytes (of buf); hex will be double
    126  * this size
    127  * Returns: 0 on success, -1 on failure (invalid hex string)
    128  */
    129 int hexstr2bin(const char *hex, u8 *buf, size_t len)
    130 {
    131 	size_t i;
    132 	int a;
    133 	const char *ipos = hex;
    134 	u8 *opos = buf;
    135 
    136 	for (i = 0; i < len; i++) {
    137 		a = hex2byte(ipos);
    138 		if (a < 0)
    139 			return -1;
    140 		*opos++ = a;
    141 		ipos += 2;
    142 	}
    143 	return 0;
    144 }
    145 
    146 
    147 /**
    148  * inc_byte_array - Increment arbitrary length byte array by one
    149  * @counter: Pointer to byte array
    150  * @len: Length of the counter in bytes
    151  *
    152  * This function increments the last byte of the counter by one and continues
    153  * rolling over to more significant bytes if the byte was incremented from
    154  * 0xff to 0x00.
    155  */
    156 void inc_byte_array(u8 *counter, size_t len)
    157 {
    158 	int pos = len - 1;
    159 	while (pos >= 0) {
    160 		counter[pos]++;
    161 		if (counter[pos] != 0)
    162 			break;
    163 		pos--;
    164 	}
    165 }
    166 
    167 
    168 void wpa_get_ntp_timestamp(u8 *buf)
    169 {
    170 	struct os_time now;
    171 	u32 sec, usec;
    172 	be32 tmp;
    173 
    174 	/* 64-bit NTP timestamp (time from 1900-01-01 00:00:00) */
    175 	os_get_time(&now);
    176 	sec = now.sec + 2208988800U; /* Epoch to 1900 */
    177 	/* Estimate 2^32/10^6 = 4295 - 1/32 - 1/512 */
    178 	usec = now.usec;
    179 	usec = 4295 * usec - (usec >> 5) - (usec >> 9);
    180 	tmp = host_to_be32(sec);
    181 	os_memcpy(buf, (u8 *) &tmp, 4);
    182 	tmp = host_to_be32(usec);
    183 	os_memcpy(buf + 4, (u8 *) &tmp, 4);
    184 }
    185 
    186 
    187 static inline int _wpa_snprintf_hex(char *buf, size_t buf_size, const u8 *data,
    188 				    size_t len, int uppercase)
    189 {
    190 	size_t i;
    191 	char *pos = buf, *end = buf + buf_size;
    192 	int ret;
    193 	if (buf_size == 0)
    194 		return 0;
    195 	for (i = 0; i < len; i++) {
    196 		ret = os_snprintf(pos, end - pos, uppercase ? "%02X" : "%02x",
    197 				  data[i]);
    198 		if (ret < 0 || ret >= end - pos) {
    199 			end[-1] = '\0';
    200 			return pos - buf;
    201 		}
    202 		pos += ret;
    203 	}
    204 	end[-1] = '\0';
    205 	return pos - buf;
    206 }
    207 
    208 /**
    209  * wpa_snprintf_hex - Print data as a hex string into a buffer
    210  * @buf: Memory area to use as the output buffer
    211  * @buf_size: Maximum buffer size in bytes (should be at least 2 * len + 1)
    212  * @data: Data to be printed
    213  * @len: Length of data in bytes
    214  * Returns: Number of bytes written
    215  */
    216 int wpa_snprintf_hex(char *buf, size_t buf_size, const u8 *data, size_t len)
    217 {
    218 	return _wpa_snprintf_hex(buf, buf_size, data, len, 0);
    219 }
    220 
    221 
    222 /**
    223  * wpa_snprintf_hex_uppercase - Print data as a upper case hex string into buf
    224  * @buf: Memory area to use as the output buffer
    225  * @buf_size: Maximum buffer size in bytes (should be at least 2 * len + 1)
    226  * @data: Data to be printed
    227  * @len: Length of data in bytes
    228  * Returns: Number of bytes written
    229  */
    230 int wpa_snprintf_hex_uppercase(char *buf, size_t buf_size, const u8 *data,
    231 			       size_t len)
    232 {
    233 	return _wpa_snprintf_hex(buf, buf_size, data, len, 1);
    234 }
    235 
    236 
    237 #ifdef CONFIG_ANSI_C_EXTRA
    238 
    239 #ifdef _WIN32_WCE
    240 void perror(const char *s)
    241 {
    242 	wpa_printf(MSG_ERROR, "%s: GetLastError: %d",
    243 		   s, (int) GetLastError());
    244 }
    245 #endif /* _WIN32_WCE */
    246 
    247 
    248 int optind = 1;
    249 int optopt;
    250 char *optarg;
    251 
    252 int getopt(int argc, char *const argv[], const char *optstring)
    253 {
    254 	static int optchr = 1;
    255 	char *cp;
    256 
    257 	if (optchr == 1) {
    258 		if (optind >= argc) {
    259 			/* all arguments processed */
    260 			return EOF;
    261 		}
    262 
    263 		if (argv[optind][0] != '-' || argv[optind][1] == '\0') {
    264 			/* no option characters */
    265 			return EOF;
    266 		}
    267 	}
    268 
    269 	if (os_strcmp(argv[optind], "--") == 0) {
    270 		/* no more options */
    271 		optind++;
    272 		return EOF;
    273 	}
    274 
    275 	optopt = argv[optind][optchr];
    276 	cp = os_strchr(optstring, optopt);
    277 	if (cp == NULL || optopt == ':') {
    278 		if (argv[optind][++optchr] == '\0') {
    279 			optchr = 1;
    280 			optind++;
    281 		}
    282 		return '?';
    283 	}
    284 
    285 	if (cp[1] == ':') {
    286 		/* Argument required */
    287 		optchr = 1;
    288 		if (argv[optind][optchr + 1]) {
    289 			/* No space between option and argument */
    290 			optarg = &argv[optind++][optchr + 1];
    291 		} else if (++optind >= argc) {
    292 			/* option requires an argument */
    293 			return '?';
    294 		} else {
    295 			/* Argument in the next argv */
    296 			optarg = argv[optind++];
    297 		}
    298 	} else {
    299 		/* No argument */
    300 		if (argv[optind][++optchr] == '\0') {
    301 			optchr = 1;
    302 			optind++;
    303 		}
    304 		optarg = NULL;
    305 	}
    306 	return *cp;
    307 }
    308 #endif /* CONFIG_ANSI_C_EXTRA */
    309 
    310 
    311 #ifdef CONFIG_NATIVE_WINDOWS
    312 /**
    313  * wpa_unicode2ascii_inplace - Convert unicode string into ASCII
    314  * @str: Pointer to string to convert
    315  *
    316  * This function converts a unicode string to ASCII using the same
    317  * buffer for output. If UNICODE is not set, the buffer is not
    318  * modified.
    319  */
    320 void wpa_unicode2ascii_inplace(TCHAR *str)
    321 {
    322 #ifdef UNICODE
    323 	char *dst = (char *) str;
    324 	while (*str)
    325 		*dst++ = (char) *str++;
    326 	*dst = '\0';
    327 #endif /* UNICODE */
    328 }
    329 
    330 
    331 TCHAR * wpa_strdup_tchar(const char *str)
    332 {
    333 #ifdef UNICODE
    334 	TCHAR *buf;
    335 	buf = os_malloc((strlen(str) + 1) * sizeof(TCHAR));
    336 	if (buf == NULL)
    337 		return NULL;
    338 	wsprintf(buf, L"%S", str);
    339 	return buf;
    340 #else /* UNICODE */
    341 	return os_strdup(str);
    342 #endif /* UNICODE */
    343 }
    344 #endif /* CONFIG_NATIVE_WINDOWS */
    345 
    346 
    347 void printf_encode(char *txt, size_t maxlen, const u8 *data, size_t len)
    348 {
    349 	char *end = txt + maxlen;
    350 	size_t i;
    351 
    352 	for (i = 0; i < len; i++) {
    353 		if (txt + 4 > end)
    354 			break;
    355 
    356 		switch (data[i]) {
    357 		case '\"':
    358 			*txt++ = '\\';
    359 			*txt++ = '\"';
    360 			break;
    361 		case '\\':
    362 			*txt++ = '\\';
    363 			*txt++ = '\\';
    364 			break;
    365 		case '\e':
    366 			*txt++ = '\\';
    367 			*txt++ = 'e';
    368 			break;
    369 		case '\n':
    370 			*txt++ = '\\';
    371 			*txt++ = 'n';
    372 			break;
    373 		case '\r':
    374 			*txt++ = '\\';
    375 			*txt++ = 'r';
    376 			break;
    377 		case '\t':
    378 			*txt++ = '\\';
    379 			*txt++ = 't';
    380 			break;
    381 		default:
    382 			if (data[i] >= 32 && data[i] <= 127) {
    383 				*txt++ = data[i];
    384 			} else {
    385 				txt += os_snprintf(txt, end - txt, "\\x%02x",
    386 						   data[i]);
    387 			}
    388 			break;
    389 		}
    390 	}
    391 
    392 	*txt = '\0';
    393 }
    394 
    395 
    396 size_t printf_decode(u8 *buf, size_t maxlen, const char *str)
    397 {
    398 	const char *pos = str;
    399 	size_t len = 0;
    400 	int val;
    401 
    402 	while (*pos) {
    403 		if (len == maxlen)
    404 			break;
    405 		switch (*pos) {
    406 		case '\\':
    407 			pos++;
    408 			switch (*pos) {
    409 			case '\\':
    410 				buf[len++] = '\\';
    411 				pos++;
    412 				break;
    413 			case '"':
    414 				buf[len++] = '"';
    415 				pos++;
    416 				break;
    417 			case 'n':
    418 				buf[len++] = '\n';
    419 				pos++;
    420 				break;
    421 			case 'r':
    422 				buf[len++] = '\r';
    423 				pos++;
    424 				break;
    425 			case 't':
    426 				buf[len++] = '\t';
    427 				pos++;
    428 				break;
    429 			case 'e':
    430 				buf[len++] = '\e';
    431 				pos++;
    432 				break;
    433 			case 'x':
    434 				pos++;
    435 				val = hex2byte(pos);
    436 				if (val < 0) {
    437 					val = hex2num(*pos);
    438 					if (val < 0)
    439 						break;
    440 					buf[len++] = val;
    441 					pos++;
    442 				} else {
    443 					buf[len++] = val;
    444 					pos += 2;
    445 				}
    446 				break;
    447 			case '0':
    448 			case '1':
    449 			case '2':
    450 			case '3':
    451 			case '4':
    452 			case '5':
    453 			case '6':
    454 			case '7':
    455 				val = *pos++ - '0';
    456 				if (*pos >= '0' && *pos <= '7')
    457 					val = val * 8 + (*pos++ - '0');
    458 				if (*pos >= '0' && *pos <= '7')
    459 					val = val * 8 + (*pos++ - '0');
    460 				buf[len++] = val;
    461 				break;
    462 			default:
    463 				break;
    464 			}
    465 			break;
    466 		default:
    467 			buf[len++] = *pos++;
    468 			break;
    469 		}
    470 	}
    471 
    472 	return len;
    473 }
    474 
    475 
    476 /**
    477  * wpa_ssid_txt - Convert SSID to a printable string
    478  * @ssid: SSID (32-octet string)
    479  * @ssid_len: Length of ssid in octets
    480  * Returns: Pointer to a printable string
    481  *
    482  * This function can be used to convert SSIDs into printable form. In most
    483  * cases, SSIDs do not use unprintable characters, but IEEE 802.11 standard
    484  * does not limit the used character set, so anything could be used in an SSID.
    485  *
    486  * This function uses a static buffer, so only one call can be used at the
    487  * time, i.e., this is not re-entrant and the returned buffer must be used
    488  * before calling this again.
    489  */
    490 const char * wpa_ssid_txt(const u8 *ssid, size_t ssid_len)
    491 {
    492 	static char ssid_txt[32 * 4 + 1];
    493 
    494 	if (ssid == NULL) {
    495 		ssid_txt[0] = '\0';
    496 		return ssid_txt;
    497 	}
    498 
    499 	printf_encode(ssid_txt, sizeof(ssid_txt), ssid, ssid_len);
    500 	return ssid_txt;
    501 }
    502 
    503 
    504 void * __hide_aliasing_typecast(void *foo)
    505 {
    506 	return foo;
    507 }
    508 
    509 
    510 char * wpa_config_parse_string(const char *value, size_t *len)
    511 {
    512 	if (*value == '"') {
    513 		const char *pos;
    514 		char *str;
    515 		value++;
    516 		pos = os_strrchr(value, '"');
    517 		if (pos == NULL || pos[1] != '\0')
    518 			return NULL;
    519 		*len = pos - value;
    520 		str = os_malloc(*len + 1);
    521 		if (str == NULL)
    522 			return NULL;
    523 		os_memcpy(str, value, *len);
    524 		str[*len] = '\0';
    525 		return str;
    526 	} else if (*value == 'P' && value[1] == '"') {
    527 		const char *pos;
    528 		char *tstr, *str;
    529 		size_t tlen;
    530 		value += 2;
    531 		pos = os_strrchr(value, '"');
    532 		if (pos == NULL || pos[1] != '\0')
    533 			return NULL;
    534 		tlen = pos - value;
    535 		tstr = os_malloc(tlen + 1);
    536 		if (tstr == NULL)
    537 			return NULL;
    538 		os_memcpy(tstr, value, tlen);
    539 		tstr[tlen] = '\0';
    540 
    541 		str = os_malloc(tlen + 1);
    542 		if (str == NULL) {
    543 			os_free(tstr);
    544 			return NULL;
    545 		}
    546 
    547 		*len = printf_decode((u8 *) str, tlen + 1, tstr);
    548 		os_free(tstr);
    549 
    550 		return str;
    551 	} else {
    552 		u8 *str;
    553 		size_t tlen, hlen = os_strlen(value);
    554 		if (hlen & 1)
    555 			return NULL;
    556 		tlen = hlen / 2;
    557 		str = os_malloc(tlen + 1);
    558 		if (str == NULL)
    559 			return NULL;
    560 		if (hexstr2bin(value, str, tlen)) {
    561 			os_free(str);
    562 			return NULL;
    563 		}
    564 		str[tlen] = '\0';
    565 		*len = tlen;
    566 		return (char *) str;
    567 	}
    568 }
    569 
    570 
    571 int is_hex(const u8 *data, size_t len)
    572 {
    573 	size_t i;
    574 
    575 	for (i = 0; i < len; i++) {
    576 		if (data[i] < 32 || data[i] >= 127)
    577 			return 1;
    578 	}
    579 	return 0;
    580 }
    581 
    582 
    583 size_t merge_byte_arrays(u8 *res, size_t res_len,
    584 			 const u8 *src1, size_t src1_len,
    585 			 const u8 *src2, size_t src2_len)
    586 {
    587 	size_t len = 0;
    588 
    589 	os_memset(res, 0, res_len);
    590 
    591 	if (src1) {
    592 		if (src1_len >= res_len) {
    593 			os_memcpy(res, src1, res_len);
    594 			return res_len;
    595 		}
    596 
    597 		os_memcpy(res, src1, src1_len);
    598 		len += src1_len;
    599 	}
    600 
    601 	if (src2) {
    602 		if (len + src2_len >= res_len) {
    603 			os_memcpy(res + len, src2, res_len - len);
    604 			return res_len;
    605 		}
    606 
    607 		os_memcpy(res + len, src2, src2_len);
    608 		len += src2_len;
    609 	}
    610 
    611 	return len;
    612 }
    613