X-Git-Url: https://mattmccutchen.net/rsync/rsync.git/blobdiff_plain/9a689986c6d416c66195d2a16f54fcb74dc7d805..8f694072a524ab0f7edc4c3402fb5fc41ecbfa5e:/lib/inet_ntop.c

diff --git a/lib/inet_ntop.c b/lib/inet_ntop.c
new file mode 100644
index 00000000..9451d23d
--- /dev/null
+++ b/lib/inet_ntop.c
@@ -0,0 +1,194 @@
+/*
+ * Copyright (C) 1996-2001  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.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char rcsid[] =
+	"$Id$";
+#endif /* LIBC_SCCS and not lint */
+
+#include <config.h>
+
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+
+#include <isc/net.h>
+
+#define NS_INT16SZ	 2
+#define NS_IN6ADDRSZ	16
+
+/*
+ * 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.
+ */
+
+static const char *inet_ntop4(const unsigned char *src, char *dst,
+			      size_t size);
+
+#ifdef AF_INET6
+static const char *inet_ntop6(const unsigned char *src, char *dst,
+			      size_t size);
+#endif
+
+/* char *
+ * isc_net_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.
+ */
+const char *
+isc_net_ntop(int af, const void *src, char *dst, size_t size)
+{
+	switch (af) {
+	case AF_INET:
+		return (inet_ntop4(src, dst, size));
+#ifdef AF_INET6
+	case AF_INET6:
+		return (inet_ntop6(src, dst, size));
+#endif
+	default:
+		errno = EAFNOSUPPORT;
+		return (NULL);
+	}
+	/* NOTREACHED */
+}
+
+/* const char *
+ * inet_ntop4(src, dst, size)
+ *	format an IPv4 address
+ * return:
+ *	`dst' (as a const)
+ * notes:
+ *	(1) uses no statics
+ *	(2) takes a unsigned char* not an in_addr as input
+ * author:
+ *	Paul Vixie, 1996.
+ */
+static const char *
+inet_ntop4(const unsigned char *src, char *dst, size_t size)
+{
+	static const char *fmt = "%u.%u.%u.%u";
+	char tmp[sizeof "255.255.255.255"];
+
+	if ((size_t)sprintf(tmp, fmt, src[0], src[1], src[2], src[3]) >= size)
+	{
+		errno = ENOSPC;
+		return (NULL);
+	}
+	strcpy(dst, tmp);
+
+	return (dst);
+}
+
+/* const char *
+ * isc_inet_ntop6(src, dst, size)
+ *	convert IPv6 binary address into presentation (printable) format
+ * author:
+ *	Paul Vixie, 1996.
+ */
+#ifdef AF_INET6
+static const char *
+inet_ntop6(const unsigned char *src, char *dst, size_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;
+	unsigned int words[NS_IN6ADDRSZ / NS_INT16SZ];
+	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 < NS_IN6ADDRSZ; i++)
+		words[i / 2] |= (src[i] << ((1 - (i % 2)) << 3));
+	best.base = -1;
+	cur.base = -1;
+	for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); 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 < (NS_IN6ADDRSZ / NS_INT16SZ); 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) ==
+	    (NS_IN6ADDRSZ / NS_INT16SZ))
+		*tp++ = ':';
+	*tp++ = '\0';
+
+	/*
+	 * Check for overflow, copy, and we're done.
+	 */
+	if ((size_t)(tp - tmp) > size) {
+		errno = ENOSPC;
+		return (NULL);
+	}
+	strcpy(dst, tmp);
+	return (dst);
+}
+#endif /* AF_INET6 */