Sync inet_net_pton() and inet_net_ntop() with latest BIND9's includes

an IPv6 support.

PR:		kern/93740
Submitted by:	Rudolf Cejka <cejkar__at__fit.vutbr.cz>
Obtained from:	BIND9
MFC after:	1 week

3 files changed, 420 insertions, 85 deletions

diff --git a/lib/libc/net/inet_net.3 b/lib/libc/net/inet_net.3
index 9ca00a6..a9d0781 100644
--- a/lib/libc/net/inet_net.3
+++ b/lib/libc/net/inet_net.3
@@ -36,7 +36,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd June 18, 1997
+.Dd February 26, 2006
 .Dt INET_NET 3
 .Os
 .Sh NAME
@@ -88,10 +88,12 @@ It will be set to
 .Er ENOENT
 if the Internet network number was not valid).
 .Pp
-The only value for
+The currently supported values for
 .Fa af
-currently supported is
-.Dv AF_INET .
+are
+.Dv AF_INET
+and
+.Dv AF_INET6 .
 The
 .Fa size
 argument
@@ -149,6 +151,10 @@ may be decimal, octal, or hexadecimal, as specified
 in the C language (i.e., a leading 0x or 0X implies
 hexadecimal; otherwise, a leading 0 implies octal;
 otherwise, the number is interpreted as decimal).
+.\"
+.\" .Sh NETWORK NUMBERS (IP VERSION 6)
+.\" XXX - document this!
+.\"
 .Sh SEE ALSO
 .Xr byteorder 3 ,
 .Xr inet 3 ,
diff --git a/lib/libc/net/inet_net_ntop.c b/lib/libc/net/inet_net_ntop.c
index 8f3b1d7..9258273 100644
--- a/lib/libc/net/inet_net_ntop.c
+++ b/lib/libc/net/inet_net_ntop.c
@@ -1,22 +1,22 @@
 /*
- * Copyright (c) 1996 by Internet Software Consortium.
+ * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
+ * Copyright (c) 1996,1999 by Internet Software Consortium.
  *
  * Permission to use, copy, modify, and distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
  * copyright notice and this permission notice appear in all copies.
  *
- * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
- * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
- * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
- * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
- * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
- * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
- * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
- * SOFTWARE.
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
+ * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
 #if defined(LIBC_SCCS) && !defined(lint)
-static const char orig_rcsid[] = "From Id: inet_net_ntop.c,v 8.2 1996/08/08 06:54:44 vixie Exp";
+static const char orig_rcsid[] = "From Id: inet_net_ntop.c,v 1.1.2.1.8.1 2004/03/09 08:33:32 marka Exp";
 #endif
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
@@ -39,6 +39,8 @@ __FBSDID("$FreeBSD$");
 
 static char *	inet_net_ntop_ipv4(const u_char *src, int bits, char *dst,
 		    size_t size);
+static char *	inet_net_ntop_ipv6(const u_char *src, int bits, char *dst,
+		    size_t size);
 
 /*
  * char *
@@ -61,6 +63,8 @@ inet_net_ntop(af, src, bits, dst, size)
 	switch (af) {
 	case AF_INET:
 		return (inet_net_ntop_ipv4(src, bits, dst, size));
+	case AF_INET6:
+		return (inet_net_ntop_ipv6(src, bits, dst, size));
 	default:
 		errno = EAFNOSUPPORT;
 		return (NULL);
@@ -76,7 +80,7 @@ inet_net_ntop(af, src, bits, dst, size)
  *	pointer to dst, or NULL if an error occurred (check errno).
  * note:
  *	network byte order assumed.  this means 192.5.5.240/28 has
- *	0x11110000 in its fourth octet.
+ *	0b11110000 in its fourth octet.
  * author:
  *	Paul Vixie (ISC), July 1996
  */
@@ -96,16 +100,18 @@ inet_net_ntop_ipv4(src, bits, dst, size)
 		errno = EINVAL;
 		return (NULL);
 	}
+
 	if (bits == 0) {
 		if (size < sizeof "0")
 			goto emsgsize;
 		*dst++ = '0';
+		size--;
 		*dst = '\0';
 	}
 
 	/* Format whole octets. */
 	for (b = bits / 8; b > 0; b--) {
-		if (size < sizeof "255.")
+		if (size <= sizeof "255.")
 			goto emsgsize;
 		t = dst;
 		dst += SPRINTF((dst, "%u", *src++));
@@ -119,7 +125,7 @@ inet_net_ntop_ipv4(src, bits, dst, size)
 	/* Format partial octet. */
 	b = bits % 8;
 	if (b > 0) {
-		if (size < sizeof ".255")
+		if (size <= sizeof ".255")
 			goto emsgsize;
 		t = dst;
 		if (dst != odst)
@@ -130,7 +136,7 @@ inet_net_ntop_ipv4(src, bits, dst, size)
 	}
 
 	/* Format CIDR /width. */
-	if (size < sizeof "/32")
+	if (size <= sizeof "/32")
 		goto emsgsize;
 	dst += SPRINTF((dst, "/%u", bits));
 	return (odst);
@@ -141,6 +147,133 @@ inet_net_ntop_ipv4(src, bits, dst, size)
 }
 
 /*
+ * static char *
+ * inet_net_ntop_ipv6(src, bits, fakebits, dst, size)
+ *	convert IPv6 network number from network to presentation format.
+ *	generates CIDR style result always. Picks the shortest representation
+ *	unless the IP is really IPv4.
+ *	always prints specified number of bits (bits).
+ * return:
+ *	pointer to dst, or NULL if an error occurred (check errno).
+ * note:
+ *	network byte order assumed.  this means 192.5.5.240/28 has
+ *	0b11110000 in its fourth octet.
+ * author:
+ *	Vadim Kogan (UCB), June 2001
+ *  Original version (IPv4) by Paul Vixie (ISC), July 1996
+ */
+
+static char *
+inet_net_ntop_ipv6(const u_char *src, int bits, char *dst, size_t size) {
+	u_int	m;
+	int	b;
+	int	p;
+	int	zero_s, zero_l, tmp_zero_s, tmp_zero_l;
+	int	i;
+	int	is_ipv4 = 0;
+	unsigned char inbuf[16];
+	char outbuf[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255/128")];
+	char	*cp;
+	int	words;
+	u_char	*s;
+
+	if (bits < 0 || bits > 128) {
+		errno = EINVAL;
+		return (NULL);
+	}
+
+	cp = outbuf;
+
+	if (bits == 0) {
+		*cp++ = ':';
+		*cp++ = ':';
+		*cp = '\0';
+	} else {
+		/* Copy src to private buffer.  Zero host part. */
+		p = (bits + 7) / 8;
+		memcpy(inbuf, src, p);
+		memset(inbuf + p, 0, 16 - p);
+		b = bits % 8;
+		if (b != 0) {
+			m = ~0 << (8 - b);
+			inbuf[p-1] &= m;
+		}
+
+		s = inbuf;
+
+		/* how many words need to be displayed in output */
+		words = (bits + 15) / 16;
+		if (words == 1)
+			words = 2;
+
+		/* Find the longest substring of zero's */
+		zero_s = zero_l = tmp_zero_s = tmp_zero_l = 0;
+		for (i = 0; i < (words * 2); i += 2) {
+			if ((s[i] | s[i+1]) == 0) {
+				if (tmp_zero_l == 0)
+					tmp_zero_s = i / 2;
+				tmp_zero_l++;
+			} else {
+				if (tmp_zero_l && zero_l < tmp_zero_l) {
+					zero_s = tmp_zero_s;
+					zero_l = tmp_zero_l;
+					tmp_zero_l = 0;
+				}
+			}
+		}
+
+		if (tmp_zero_l && zero_l < tmp_zero_l) {
+			zero_s = tmp_zero_s;
+			zero_l = tmp_zero_l;
+		}
+
+		if (zero_l != words && zero_s == 0 && ((zero_l == 6) ||
+		    ((zero_l == 5 && s[10] == 0xff && s[11] == 0xff) ||
+		    ((zero_l == 7 && s[14] != 0 && s[15] != 1)))))
+			is_ipv4 = 1;
+
+		/* Format whole words. */
+		for (p = 0; p < words; p++) {
+			if (zero_l != 0 && p >= zero_s && p < zero_s + zero_l) {
+				/* Time to skip some zeros */
+				if (p == zero_s)
+					*cp++ = ':';
+				if (p == words - 1)
+					*cp++ = ':';
+				s++;
+				s++;
+				continue;
+			}
+
+			if (is_ipv4 && p > 5 ) {
+				*cp++ = (p == 6) ? ':' : '.';
+				cp += SPRINTF((cp, "%u", *s++));
+				/* we can potentially drop the last octet */
+				if (p != 7 || bits > 120) {
+					*cp++ = '.';
+					cp += SPRINTF((cp, "%u", *s++));
+				}
+			} else {
+				if (cp != outbuf)
+					*cp++ = ':';
+				cp += SPRINTF((cp, "%x", *s * 256 + s[1]));
+				s += 2;
+			}
+		}
+	}
+	/* Format CIDR /width. */
+	SPRINTF((cp, "/%u", bits));
+	if (strlen(outbuf) + 1 > size)
+		goto emsgsize;
+	strcpy(dst, outbuf);
+
+	return (dst);
+
+emsgsize:
+	errno = EMSGSIZE;
+	return (NULL);
+}
+/*
  * Weak aliases for applications that use certain private entry points,
  * and fail to include <arpa/inet.h>.
  */
diff --git a/lib/libc/net/inet_net_pton.c b/lib/libc/net/inet_net_pton.c
index 3a71454..edd4678 100644
--- a/lib/libc/net/inet_net_pton.c
+++ b/lib/libc/net/inet_net_pton.c
@@ -1,22 +1,22 @@
 /*
- * Copyright (c) 1996 by Internet Software Consortium.
+ * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
+ * Copyright (c) 1996,1999 by Internet Software Consortium.
  *
  * Permission to use, copy, modify, and distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
  * copyright notice and this permission notice appear in all copies.
  *
- * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
- * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
- * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
- * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
- * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
- * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
- * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
- * SOFTWARE.
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
+ * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
 #if defined(LIBC_SCCS) && !defined(lint)
-static const char orig_rcsid[] = "From Id: inet_net_pton.c,v 1.8 1996/11/21 10:28:12 vixie Exp $";
+static const char orig_rcsid[] = "From Id: inet_net_pton.c,v 1.4.2.1.8.2 2004/03/17 00:29:47 marka Exp";
 #endif
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
@@ -24,6 +24,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <netinet/in.h>
+#include <arpa/nameser.h>
 #include <arpa/inet.h>
 
 #include <assert.h>
@@ -39,37 +40,6 @@ __FBSDID("$FreeBSD$");
 # define SPRINTF(x) ((size_t)sprintf x)
 #endif
 
-static int	inet_net_pton_ipv4(const char *src, u_char *dst, size_t size);
-
-/*
- * static int
- * inet_net_pton(af, src, dst, size)
- *	convert network number from presentation to network format.
- *	accepts hex octets, hex strings, decimal octets, and /CIDR.
- *	"size" is in bytes and describes "dst".
- * return:
- *	number of bits, either imputed classfully or specified with /CIDR,
- *	or -1 if some failure occurred (check errno).  ENOENT means it was
- *	not a valid network specification.
- * author:
- *	Paul Vixie (ISC), June 1996
- */
-int
-inet_net_pton(af, src, dst, size)
-	int af;
-	const char *src;
-	void *dst;
-	size_t size;
-{
-	switch (af) {
-	case AF_INET:
-		return (inet_net_pton_ipv4(src, dst, size));
-	default:
-		errno = EAFNOSUPPORT;
-		return (-1);
-	}
-}
-
 /*
  * static int
  * inet_net_pton_ipv4(src, dst, size)
@@ -82,46 +52,47 @@ inet_net_pton(af, src, dst, size)
  *	not an IPv4 network specification.
  * note:
  *	network byte order assumed.  this means 192.5.5.240/28 has
- *	0x11110000 in its fourth octet.
+ *	0b11110000 in its fourth octet.
  * author:
  *	Paul Vixie (ISC), June 1996
  */
 static int
-inet_net_pton_ipv4(src, dst, size)
-	const char *src;
-	u_char *dst;
-	size_t size;
-{
-	static const char
-		xdigits[] = "0123456789abcdef",
-		digits[] = "0123456789";
-	int n, ch, tmp, dirty, bits;
+inet_net_pton_ipv4(const char *src, u_char *dst, size_t size) {
+	static const char xdigits[] = "0123456789abcdef";
+	static const char digits[] = "0123456789";
+	int n, ch, tmp = 0, dirty, bits;
 	const u_char *odst = dst;
 
 	ch = *src++;
 	if (ch == '0' && (src[0] == 'x' || src[0] == 'X')
-	    && isascii(src[1]) && isxdigit(src[1])) {
+	    && isascii((unsigned char)(src[1]))
+	    && isxdigit((unsigned char)(src[1]))) {
 		/* Hexadecimal: Eat nybble string. */
-		if (size <= 0)
+		if (size <= 0U)
 			goto emsgsize;
-		*dst = 0, dirty = 0;
+		dirty = 0;
 		src++;	/* skip x or X. */
-		while ((ch = *src++) != '\0' &&
-		       isascii(ch) && isxdigit(ch)) {
+		while ((ch = *src++) != '\0' && isascii(ch) && isxdigit(ch)) {
 			if (isupper(ch))
 				ch = tolower(ch);
 			n = strchr(xdigits, ch) - xdigits;
 			assert(n >= 0 && n <= 15);
-			*dst |= n;
-			if (!dirty++)
-				*dst <<= 4;
-			else if (size-- > 0)
-				*++dst = 0, dirty = 0;
+			if (dirty == 0)
+				tmp = n;
 			else
+				tmp = (tmp << 4) | n;
+			if (++dirty == 2) {
+				if (size-- <= 0U)
+					goto emsgsize;
+				*dst++ = (u_char) tmp;
+				dirty = 0;
+			}
+		}
+		if (dirty) {  /* Odd trailing nybble? */
+			if (size-- <= 0U)
 				goto emsgsize;
+			*dst++ = (u_char) (tmp << 4);
 		}
-		if (dirty)
-			size--;
 	} else if (isascii(ch) && isdigit(ch)) {
 		/* Decimal: eat dotted digit string. */
 		for (;;) {
@@ -135,7 +106,7 @@ inet_net_pton_ipv4(src, dst, size)
 					goto enoent;
 			} while ((ch = *src++) != '\0' &&
 				 isascii(ch) && isdigit(ch));
-			if (size-- <= 0)
+			if (size-- <= 0U)
 				goto emsgsize;
 			*dst++ = (u_char) tmp;
 			if (ch == '\0' || ch == '/')
@@ -150,7 +121,8 @@ inet_net_pton_ipv4(src, dst, size)
 		goto enoent;
 
 	bits = -1;
-	if (ch == '/' && isascii(src[0]) && isdigit(src[0]) && dst > odst) {
+	if (ch == '/' && isascii((unsigned char)(src[0])) &&
+	    isdigit((unsigned char)(src[0])) && dst > odst) {
 		/* CIDR width specifier.  Nothing can follow it. */
 		ch = *src++;	/* Skip over the /. */
 		bits = 0;
@@ -178,7 +150,7 @@ inet_net_pton_ipv4(src, dst, size)
 		if (*odst >= 240)	/* Class E */
 			bits = 32;
 		else if (*odst >= 224)	/* Class D */
-			bits = 4;
+			bits = 8;
 		else if (*odst >= 192)	/* Class C */
 			bits = 24;
 		else if (*odst >= 128)	/* Class B */
@@ -188,10 +160,16 @@ inet_net_pton_ipv4(src, dst, size)
 		/* If imputed mask is narrower than specified octets, widen. */
 		if (bits < ((dst - odst) * 8))
 			bits = (dst - odst) * 8;
+		/*
+		 * If there are no additional bits specified for a class D
+		 * address adjust bits to 4.
+		 */
+		if (bits == 8 && *odst == 224)
+			bits = 4;
 	}
 	/* Extend network to cover the actual mask. */
 	while (bits > ((dst - odst) * 8)) {
-		if (size-- <= 0)
+		if (size-- <= 0U)
 			goto emsgsize;
 		*dst++ = '\0';
 	}
@@ -206,6 +184,224 @@ inet_net_pton_ipv4(src, dst, size)
 	return (-1);
 }
 
+static int
+getbits(const char *src, int *bitsp) {
+	static const char digits[] = "0123456789";
+	int n;
+	int val;
+	char ch;
+
+	val = 0;
+	n = 0;
+	while ((ch = *src++) != '\0') {
+		const char *pch;
+
+		pch = strchr(digits, ch);
+		if (pch != NULL) {
+			if (n++ != 0 && val == 0)	/* no leading zeros */
+				return (0);
+			val *= 10;
+			val += (pch - digits);
+			if (val > 128)			/* range */
+				return (0);
+			continue;
+		}
+		return (0);
+	}
+	if (n == 0)
+		return (0);
+	*bitsp = val;
+	return (1);
+}
+
+static int
+getv4(const char *src, u_char *dst, int *bitsp) {
+	static const char digits[] = "0123456789";
+	u_char *odst = dst;
+	int n;
+	u_int val;
+	char ch;
+
+	val = 0;
+	n = 0;
+	while ((ch = *src++) != '\0') {
+		const char *pch;
+
+		pch = strchr(digits, ch);
+		if (pch != NULL) {
+			if (n++ != 0 && val == 0)	/* no leading zeros */
+				return (0);
+			val *= 10;
+			val += (pch - digits);
+			if (val > 255)			/* range */
+				return (0);
+			continue;
+		}
+		if (ch == '.' || ch == '/') {
+			if (dst - odst > 3)		/* too many octets? */
+				return (0);
+			*dst++ = val;
+			if (ch == '/')
+				return (getbits(src, bitsp));
+			val = 0;
+			n = 0;
+			continue;
+		}
+		return (0);
+	}
+	if (n == 0)
+		return (0);
+	if (dst - odst > 3)		/* too many octets? */
+		return (0);
+	*dst++ = val;
+	return (1);
+}
+
+static int
+inet_net_pton_ipv6(const char *src, u_char *dst, size_t size) {
+	static const char xdigits_l[] = "0123456789abcdef",
+			  xdigits_u[] = "0123456789ABCDEF";
+	u_char tmp[NS_IN6ADDRSZ], *tp, *endp, *colonp;
+	const char *xdigits, *curtok;
+	int ch, saw_xdigit;
+	u_int val;
+	int digits;
+	int bits;
+	size_t bytes;
+	int words;
+	int ipv4;
+
+	memset((tp = tmp), '\0', NS_IN6ADDRSZ);
+	endp = tp + NS_IN6ADDRSZ;
+	colonp = NULL;
+	/* Leading :: requires some special handling. */
+	if (*src == ':')
+		if (*++src != ':')
+			goto enoent;
+	curtok = src;
+	saw_xdigit = 0;
+	val = 0;
+	digits = 0;
+	bits = -1;
+	ipv4 = 0;
+	while ((ch = *src++) != '\0') {
+		const char *pch;
+
+		if ((pch = strchr((xdigits = xdigits_l), ch)) == NULL)
+			pch = strchr((xdigits = xdigits_u), ch);
+		if (pch != NULL) {
+			val <<= 4;
+			val |= (pch - xdigits);
+			if (++digits > 4)
+				goto enoent;
+			saw_xdigit = 1;
+			continue;
+		}
+		if (ch == ':') {
+			curtok = src;
+			if (!saw_xdigit) {
+				if (colonp)
+					goto enoent;
+				colonp = tp;
+				continue;
+			} else if (*src == '\0')
+				goto enoent;
+			if (tp + NS_INT16SZ > endp)
+				return (0);
+			*tp++ = (u_char) (val >> 8) & 0xff;
+			*tp++ = (u_char) val & 0xff;
+			saw_xdigit = 0;
+			digits = 0;
+			val = 0;
+			continue;
+		}
+		if (ch == '.' && ((tp + NS_INADDRSZ) <= endp) &&
+		     getv4(curtok, tp, &bits) > 0) {
+			tp += NS_INADDRSZ;
+			saw_xdigit = 0;
+			ipv4 = 1;
+			break;	/* '\0' was seen by inet_pton4(). */
+		}
+		if (ch == '/' && getbits(src, &bits) > 0)
+			break;
+		goto enoent;
+	}
+	if (saw_xdigit) {
+		if (tp + NS_INT16SZ > endp)
+			goto enoent;
+		*tp++ = (u_char) (val >> 8) & 0xff;
+		*tp++ = (u_char) val & 0xff;
+	}
+	if (bits == -1)
+		bits = 128;
+
+	words = (bits + 15) / 16;
+	if (words < 2)
+		words = 2;
+	if (ipv4)
+		words = 8;
+	endp =  tmp + 2 * words;
+
+	if (colonp != NULL) {
+		/*
+		 * Since some memmove()'s erroneously fail to handle
+		 * overlapping regions, we'll do the shift by hand.
+		 */
+		const int n = tp - colonp;
+		int i;
+
+		if (tp == endp)
+			goto enoent;
+		for (i = 1; i <= n; i++) {
+			endp[- i] = colonp[n - i];
+			colonp[n - i] = 0;
+		}
+		tp = endp;
+	}
+	if (tp != endp)
+		goto enoent;
+
+	bytes = (bits + 7) / 8;
+	if (bytes > size)
+		goto emsgsize;
+	memcpy(dst, tmp, bytes);
+	return (bits);
+
+ enoent:
+	errno = ENOENT;
+	return (-1);
+
+ emsgsize:
+	errno = EMSGSIZE;
+	return (-1);
+}
+
+/*
+ * int
+ * inet_net_pton(af, src, dst, size)
+ *	convert network number from presentation to network format.
+ *	accepts hex octets, hex strings, decimal octets, and /CIDR.
+ *	"size" is in bytes and describes "dst".
+ * return:
+ *	number of bits, either imputed classfully or specified with /CIDR,
+ *	or -1 if some failure occurred (check errno).  ENOENT means it was
+ *	not a valid network specification.
+ * author:
+ *	Paul Vixie (ISC), June 1996
+ */
+int
+inet_net_pton(int af, const char *src, void *dst, size_t size) {
+	switch (af) {
+	case AF_INET:
+		return (inet_net_pton_ipv4(src, dst, size));
+	case AF_INET6:
+		return (inet_net_pton_ipv6(src, dst, size));
+	default:
+		errno = EAFNOSUPPORT;
+		return (-1);
+	}
+}
+
 /*
  * Weak aliases for applications that use certain private entry points,
  * and fail to include <arpa/inet.h>.