git

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/*
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 * Copyright (c) 1996-1999 by Internet Software Consortium.
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 *
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 * Permission to use, copy, modify, and distribute this software for any
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 * purpose with or without fee is hereby granted, provided that the above
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 * copyright notice and this permission notice appear in all copies.
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 *
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 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
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 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
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 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
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 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
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 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
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 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
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 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
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 * SOFTWARE.
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 */
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#include "../git-compat-util.h"
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#ifndef NS_INADDRSZ
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#define NS_INADDRSZ	4
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#endif
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#ifndef NS_IN6ADDRSZ
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#define NS_IN6ADDRSZ	16
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#endif
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#ifndef NS_INT16SZ
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#define NS_INT16SZ	2
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#endif
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/*
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 * WARNING: Don't even consider trying to compile this on a system where
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 * sizeof(int) < 4.  sizeof(int) > 4 is fine; all the world's not a VAX.
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 */
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/* const char *
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 * inet_ntop4(src, dst, size)
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 *	format an IPv4 address
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 * return:
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 *	`dst' (as a const)
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 * notes:
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 *	(1) uses no statics
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 *	(2) takes a u_char* not an in_addr as input
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 * author:
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 *	Paul Vixie, 1996.
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 */
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static const char *
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inet_ntop4(const u_char *src, char *dst, size_t size)
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{
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	static const char fmt[] = "%u.%u.%u.%u";
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	char tmp[sizeof "255.255.255.255"];
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	int nprinted;
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	nprinted = snprintf(tmp, sizeof(tmp), fmt, src[0], src[1], src[2], src[3]);
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	if (nprinted < 0)
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		return (NULL);	/* we assume "errno" was set by "snprintf()" */
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	if ((size_t)nprinted >= size) {
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		errno = ENOSPC;
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		return (NULL);
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	}
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	strlcpy(dst, tmp, size);
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	return (dst);
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}
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#ifndef NO_IPV6
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/* const char *
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 * inet_ntop6(src, dst, size)
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 *	convert IPv6 binary address into presentation (printable) format
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 * author:
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 *	Paul Vixie, 1996.
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 */
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static const char *
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inet_ntop6(const u_char *src, char *dst, size_t size)
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{
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	/*
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	 * Note that int32_t and int16_t need only be "at least" large enough
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	 * to contain a value of the specified size.  On some systems, like
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	 * Crays, there is no such thing as an integer variable with 16 bits.
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	 * Keep this in mind if you think this function should have been coded
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	 * to use pointer overlays.  All the world's not a VAX.
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	 */
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	char tmp[sizeof "ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255"], *tp;
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	struct { int base, len; } best, cur;
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	unsigned int words[NS_IN6ADDRSZ / NS_INT16SZ];
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	int i;
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	/*
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	 * Preprocess:
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	 *	Copy the input (bytewise) array into a wordwise array.
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	 *	Find the longest run of 0x00's in src[] for :: shorthanding.
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	 */
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	memset(words, '\0', sizeof words);
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	for (i = 0; i < NS_IN6ADDRSZ; i++)
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		words[i / 2] |= (src[i] << ((1 - (i % 2)) << 3));
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	best.base = -1;
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	best.len = 0;
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	cur.base = -1;
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	cur.len = 0;
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	for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++) {
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		if (words[i] == 0) {
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			if (cur.base == -1)
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				cur.base = i, cur.len = 1;
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			else
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				cur.len++;
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		} else {
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			if (cur.base != -1) {
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				if (best.base == -1 || cur.len > best.len)
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					best = cur;
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				cur.base = -1;
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			}
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		}
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	}
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	if (cur.base != -1) {
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		if (best.base == -1 || cur.len > best.len)
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			best = cur;
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	}
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	if (best.base != -1 && best.len < 2)
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		best.base = -1;
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	/*
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	 * Format the result.
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	 */
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	tp = tmp;
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	for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++) {
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		/* Are we inside the best run of 0x00's? */
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		if (best.base != -1 && i >= best.base &&
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		    i < (best.base + best.len)) {
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			if (i == best.base)
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				*tp++ = ':';
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			continue;
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		}
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		/* Are we following an initial run of 0x00s or any real hex? */
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		if (i != 0)
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			*tp++ = ':';
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		/* Is this address an encapsulated IPv4? */
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		if (i == 6 && best.base == 0 &&
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		    (best.len == 6 || (best.len == 5 && words[5] == 0xffff))) {
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			if (!inet_ntop4(src+12, tp, sizeof tmp - (tp - tmp)))
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				return (NULL);
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			tp += strlen(tp);
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			break;
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		}
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		tp += snprintf(tp, sizeof tmp - (tp - tmp), "%x", words[i]);
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	}
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	/* Was it a trailing run of 0x00's? */
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	if (best.base != -1 && (best.base + best.len) ==
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	    (NS_IN6ADDRSZ / NS_INT16SZ))
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		*tp++ = ':';
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	*tp++ = '\0';
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	/*
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	 * Check for overflow, copy, and we're done.
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	 */
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	if ((size_t)(tp - tmp) > size) {
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		errno = ENOSPC;
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		return (NULL);
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	}
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	strlcpy(dst, tmp, size);
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	return (dst);
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}
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#endif
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/* char *
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 * inet_ntop(af, src, dst, size)
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 *	convert a network format address to presentation format.
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 * return:
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 *	pointer to presentation format address (`dst'), or NULL (see errno).
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 * author:
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 *	Paul Vixie, 1996.
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 */
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const char *
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inet_ntop(int af, const void *src, char *dst, size_t size)
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{
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	switch (af) {
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	case AF_INET:
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		return (inet_ntop4(src, dst, size));
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#ifndef NO_IPV6
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	case AF_INET6:
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		return (inet_ntop6(src, dst, size));
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#endif
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	default:
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		errno = EAFNOSUPPORT;
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		return (NULL);
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	}
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	/* NOTREACHED */
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}
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