--- /dev/null
+/*
+ * 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.
+ */
+
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/null.h>
+#include <sys/socket.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 *
+inet_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"];
+ size_t len;
+
+ len = snprintf(tmp, sizeof tmp, fmt, src[0], src[1], src[2], src[3]);
+ if (len >= size) {
+ errno = ENOSPC;
+ return (NULL);
+ }
+ memcpy(dst, tmp, len + 1);
+
+ 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, inc;
+
+ /*
+ * 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;
+ }
+ inc = snprintf(tp, 5, "%x", words[i]);
+ tp += inc;
+ }
+ /* 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);
+ }
+ memcpy(dst, tmp, tp - tmp);
+ return (dst);
+}
+#endif /* AF_INET6 */