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-rw-r--r--lib/isc/inet_ntop.c196
1 files changed, 196 insertions, 0 deletions
diff --git a/lib/isc/inet_ntop.c b/lib/isc/inet_ntop.c
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+++ b/lib/isc/inet_ntop.c
@@ -0,0 +1,196 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+/*! \file */
+
+#include <config.h>
+
+#include <errno.h>
+#include <stdio.h>
+#include <inttypes.h>
+#include <string.h>
+
+#include <isc/net.h>
+#include <isc/print.h>
+#include <isc/string.h>
+#include <isc/util.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)
+ * \note
+ * (1) uses no statics
+ * \note
+ * (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")];
+ int n;
+
+
+ n = snprintf(tmp, sizeof(tmp), fmt, src[0], src[1], src[2], src[3]);
+ if (n < 0 || (size_t)n >= size) {
+ errno = ENOSPC;
+ return (NULL);
+ }
+ strlcpy(dst, tmp, size);
+
+ 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;
+ best.len = 0; /* silence compiler */
+ cur.base = -1;
+ cur.len = 0; /* silence compiler */
+ 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 == 7 && words[7] != 0x0001) ||
+ (best.len == 5 && words[5] == 0xffff))) {
+ if (!inet_ntop4(src+12, tp,
+ sizeof(tmp) - (tp - tmp)))
+ return (NULL);
+ tp += strlen(tp);
+ break;
+ }
+ INSIST((size_t)(tp - tmp) < sizeof(tmp));
+ tp += snprintf(tp, sizeof(tmp) - (tp - tmp), "%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);
+ }
+ strlcpy(dst, tmp, size);
+ return (dst);
+}
+#endif /* AF_INET6 */