Add in inet_ntop() and inet_pton() -- ported from glibc 2.2.3

by Cory Visi <merlin@phear.lwz.org>

libc/inet/ntop.c

@@ -0,0 +1,400 @@
+/*
+ * 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.
+ */
+
+#include <sys/param.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <arpa/nameser.h>
+
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+
+/*
+ * WARNING: Don't even consider trying to compile this on a system where
+ * sizeof(int) < 4.  sizeof(int) > 4 is fine; all the world's not a VAX.
+ */
+
+
+/* const char *
+ * inet_ntop4(src, dst, size)
+ *	format an IPv4 address
+ * return:
+ *	`dst' (as a const)
+ * notes:
+ *	(1) uses no statics
+ *	(2) takes a u_char* not an in_addr as input
+ * author:
+ *	Paul Vixie, 1996.
+ */
+static const char *
+inet_ntop4(src, dst, size)
+	const u_char *src;
+	char *dst;
+	socklen_t size;
+{
+	char tmp[sizeof ("255.255.255.255") + 1] = "\0";
+	int octet;
+	int i;
+
+	i = 0;
+	for (octet = 0; octet <= 3; octet++) {
+
+		if (src[octet] > 255) {
+			__set_errno (ENOSPC);
+			return (NULL);
+		}
+		tmp[i++] = '0' + src[octet] / 100;
+		if (tmp[i - 1] == '0') {
+			tmp[i - 1] = '0' + (src[octet] / 10 % 10);
+			if (tmp[i - 1] == '0') i--;
+		} else {
+			tmp[i++] = '0' + (src[octet] / 10 % 10);
+		}
+		tmp[i++] = '0' + src[octet] % 10;
+		tmp[i++] = '.';
+	}
+	tmp[i - 1] = '\0';
+
+	if (strlen (tmp) > size) {
+		__set_errno (ENOSPC);
+		return (NULL);
+	}
+
+	return strcpy(dst, tmp);
+}
+
+
+/* const char *
+ * inet_ntop6(src, dst, size)
+ *	convert IPv6 binary address into presentation (printable) format
+ * author:
+ *	Paul Vixie, 1996.
+ */
+
+#ifdef INET_IPV6
+
+static const char *
+inet_ntop6(src, dst, size)
+	const u_char *src;
+	char *dst;
+	socklen_t size;
+{
+	/*
+	 * Note that int32_t and int16_t need only be "at least" large enough
+	 * to contain a value of the specified size.  On some systems, like
+	 * Crays, there is no such thing as an integer variable with 16 bits.
+	 * Keep this in mind if you think this function should have been coded
+	 * to use pointer overlays.  All the world's not a VAX.
+	 */
+	char tmp[sizeof ("ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255")], *tp;
+	struct { int base, len; } best, cur;
+	u_int words[8];
+	int i;
+
+	/*
+	 * Preprocess:
+	 *	Copy the input (bytewise) array into a wordwise array.
+	 *	Find the longest run of 0x00's in src[] for :: shorthanding.
+	 */
+	memset(words, '\0', sizeof words);
+	for (i = 0; i < 16; i += 2)
+		words[i / 2] = (src[i] << 8) | src[i + 1];
+	best.base = -1;
+	cur.base = -1;
+	for (i = 0; i < 8; i++) {
+		if (words[i] == 0) {
+			if (cur.base == -1)
+				cur.base = i, cur.len = 1;
+			else
+				cur.len++;
+		} else {
+			if (cur.base != -1) {
+				if (best.base == -1 || cur.len > best.len)
+					best = cur;
+				cur.base = -1;
+			}
+		}
+	}
+	if (cur.base != -1) {
+		if (best.base == -1 || cur.len > best.len)
+			best = cur;
+	}
+	if (best.base != -1 && best.len < 2)
+		best.base = -1;
+
+	/*
+	 * Format the result.
+	 */
+	tp = tmp;
+	for (i = 0; i < 8; i++) {
+		/* Are we inside the best run of 0x00's? */
+		if (best.base != -1 && i >= best.base &&
+		    i < (best.base + best.len)) {
+			if (i == best.base)
+				*tp++ = ':';
+			continue;
+		}
+		/* Are we following an initial run of 0x00s or any real hex? */
+		if (i != 0)
+			*tp++ = ':';
+		/* Is this address an encapsulated IPv4? */
+		if (i == 6 && best.base == 0 &&
+		    (best.len == 6 || (best.len == 5 && words[5] == 0xffff))) {
+			if (!inet_ntop4(src+12, tp, sizeof tmp - (tp - tmp)))
+				return (NULL);
+			tp += strlen(tp);
+			break;
+		}
+		tp += SPRINTF((tp, "%x", words[i]));
+	}
+	/* Was it a trailing run of 0x00's? */
+	if (best.base != -1 && (best.base + best.len) == 8)
+		*tp++ = ':';
+	*tp++ = '\0';
+
+	/*
+	 * Check for overflow, copy, and we're done.
+	 */
+	if ((socklen_t)(tp - tmp) > size) {
+		__set_errno (ENOSPC);
+		return (NULL);
+	}
+	return strcpy(dst, tmp);
+}
+#endif /* INET_IPV6 */
+
+
+/* int
+ * inet_pton4(src, dst)
+ *	like inet_aton() but without all the hexadecimal and shorthand.
+ * return:
+ *	1 if `src' is a valid dotted quad, else 0.
+ * notice:
+ *	does not touch `dst' unless it's returning 1.
+ * author:
+ *	Paul Vixie, 1996.
+ */
+static int
+inet_pton4(src, dst)
+	const char *src;
+	u_char *dst;
+{
+	int saw_digit, octets, ch;
+	u_char tmp[4], *tp;
+
+	saw_digit = 0;
+	octets = 0;
+	*(tp = tmp) = 0;
+	while ((ch = *src++) != '\0') {
+
+		if (ch >= '0' && ch <= '9') {
+			u_int new = *tp * 10 + (ch - '0');
+
+			if (new > 255)
+				return (0);
+			*tp = new;
+			if (! saw_digit) {
+				if (++octets > 4)
+					return (0);
+				saw_digit = 1;
+			}
+		} else if (ch == '.' && saw_digit) {
+			if (octets == 4)
+				return (0);
+			*++tp = 0;
+			saw_digit = 0;
+		} else
+			return (0);
+	}
+	if (octets < 4)
+		return (0);
+	memcpy(dst, tmp, 4);
+	return (1);
+}
+
+/* int
+ * inet_pton6(src, dst)
+ *	convert presentation level address to network order binary form.
+ * return:
+ *	1 if `src' is a valid [RFC1884 2.2] address, else 0.
+ * notice:
+ *	(1) does not touch `dst' unless it's returning 1.
+ *	(2) :: in a full address is silently ignored.
+ * credit:
+ *	inspired by Mark Andrews.
+ * author:
+ *	Paul Vixie, 1996.
+ */
+
+#ifdef INET_IPV6
+
+static int
+inet_pton6(src, dst)
+	const char *src;
+	u_char *dst;
+{
+	static const char xdigits[] = "0123456789abcdef";
+	u_char tmp[16], *tp, *endp, *colonp;
+	const char *curtok;
+	int ch, saw_xdigit;
+	u_int val;
+
+	tp = memset(tmp, '\0', 16);
+	endp = tp + 16;
+	colonp = NULL;
+	/* Leading :: requires some special handling. */
+	if (*src == ':')
+		if (*++src != ':')
+			return (0);
+	curtok = src;
+	saw_xdigit = 0;
+	val = 0;
+	while ((ch = tolower (*src++)) != '\0') {
+		const char *pch;
+
+		pch = strchr(xdigits, ch);
+		if (pch != NULL) {
+			val <<= 4;
+			val |= (pch - xdigits);
+			if (val > 0xffff)
+				return (0);
+			saw_xdigit = 1;
+			continue;
+		}
+		if (ch == ':') {
+			curtok = src;
+			if (!saw_xdigit) {
+				if (colonp)
+					return (0);
+				colonp = tp;
+				continue;
+			} else if (*src == '\0') {
+				return (0);
+			}
+			if (tp + 2 > endp)
+				return (0);
+			*tp++ = (u_char) (val >> 8) & 0xff;
+			*tp++ = (u_char) val & 0xff;
+			saw_xdigit = 0;
+			val = 0;
+			continue;
+		}
+		if (ch == '.' && ((tp + 4) <= endp) &&
+		    inet_pton4(curtok, tp) > 0) {
+			tp += 4;
+			saw_xdigit = 0;
+			break;	/* '\0' was seen by inet_pton4(). */
+		}
+		return (0);
+	}
+	if (saw_xdigit) {
+		if (tp + 2 > endp)
+			return (0);
+		*tp++ = (u_char) (val >> 8) & 0xff;
+		*tp++ = (u_char) val & 0xff;
+	}
+	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)
+			return (0);
+		for (i = 1; i <= n; i++) {
+			endp[- i] = colonp[n - i];
+			colonp[n - i] = 0;
+		}
+		tp = endp;
+	}
+	if (tp != endp)
+		return (0);
+	memcpy(dst, tmp, 16);
+	return (1);
+}
+
+#endif /* INET_IPV6 */
+
+
+
+/* char *
+ * inet_ntop(af, src, dst, size)
+ *	convert a network format address to presentation format.
+ * return:
+ *	pointer to presentation format address (`dst'), or NULL (see errno).
+ * author:
+ *	Paul Vixie, 1996.
+ */
+extern const char *
+inet_ntop(af, src, dst, size)
+	int af;
+	const void *src;
+	char *dst;
+	socklen_t size;
+{
+	switch (af) {
+	case AF_INET:
+		return (inet_ntop4(src, dst, size));
+#ifdef INET_IPV6
+	case AF_INET6:
+		return (inet_ntop6(src, dst, size));
+#endif
+	default:
+		__set_errno (EAFNOSUPPORT);
+		return (NULL);
+	}
+	/* NOTREACHED */
+}
+
+
+/* int
+ * inet_pton(af, src, dst)
+ *	convert from presentation format (which usually means ASCII printable)
+ *	to network format (which is usually some kind of binary format).
+ * return:
+ *	1 if the address was valid for the specified address family
+ *	0 if the address wasn't valid (`dst' is untouched in this case)
+ *	-1 if some other error occurred (`dst' is untouched in this case, too)
+ * author:
+ *	Paul Vixie, 1996.
+ */
+extern int
+inet_pton(af, src, dst)
+	int af;
+	const char *src;
+	void *dst;
+{
+	switch (af) {
+	case AF_INET:
+		return (inet_pton4(src, dst));
+#ifdef INET_IPV6
+	case AF_INET6:
+		return (inet_pton6(src, dst));
+#endif
+	default:
+		__set_errno (EAFNOSUPPORT);
+		return (-1);
+	}
+	/* NOTREACHED */
+}
+