diff --git a/lib/krb5/addr_families.c b/lib/krb5/addr_families.c
new file mode 100644
index 000000000..09613f465
--- /dev/null
+++ b/lib/krb5/addr_families.c
@@ -0,0 +1,287 @@
+/*
+ * Copyright (c) 1997 Kungliga Tekniska Högskolan
+ * (Royal Institute of Technology, Stockholm, Sweden). 
+ * All rights reserved. 
+ *
+ * Redistribution and use in source and binary forms, with or without 
+ * modification, are permitted provided that the following conditions 
+ * are met: 
+ *
+ * 1. Redistributions of source code must retain the above copyright 
+ *    notice, this list of conditions and the following disclaimer. 
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright 
+ *    notice, this list of conditions and the following disclaimer in the 
+ *    documentation and/or other materials provided with the distribution. 
+ *
+ * 3. All advertising materials mentioning features or use of this software 
+ *    must display the following acknowledgement: 
+ *      This product includes software developed by Kungliga Tekniska 
+ *      Högskolan and its contributors. 
+ *
+ * 4. Neither the name of the Institute nor the names of its contributors 
+ *    may be used to endorse or promote products derived from this software 
+ *    without specific prior written permission. 
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND 
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE 
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 
+ * SUCH DAMAGE. 
+ */
+
+#include "krb5_locl.h"
+
+RCSID("$Id$");
+
+struct addr_operations {
+    int af;
+    krb5_address_type atype;
+    size_t max_sockaddr_size;
+    krb5_error_code (*sockaddr2addr)(const struct sockaddr *, krb5_address *);
+    krb5_boolean (*uninteresting)(const struct sockaddr *);
+    void (*h_addr2sockaddr)(const char *, struct sockaddr *, int *, int);
+    void (*anyaddr)(struct sockaddr *, int *, int);
+};
+
+/*
+ * AF_INET - aka IPv4 implementation
+ */
+
+static krb5_error_code
+ipv4_sockaddr2addr (const struct sockaddr *sa, krb5_address *a)
+{
+    const struct sockaddr_in *sin = (const struct sockaddr_in *)sa;
+    unsigned char buf[4];
+
+    a->addr_type = KRB5_ADDRESS_INET;
+    memcpy (buf, &sin->sin_addr, 4);
+    return krb5_data_copy(&a->address, buf, 4);
+}
+
+/*
+ * Are there any addresses that should be considered `uninteresting'?
+ */
+
+static krb5_boolean
+ipv4_uninteresting (const struct sockaddr *sa)
+{
+    return FALSE;
+}
+
+static void
+ipv4_h_addr2sockaddr(const char *addr,
+		     struct sockaddr *sa, int *sa_size, int port)
+{
+    struct sockaddr_in *sin = (struct sockaddr_in *)sa;
+
+    memset (sin, 0, sizeof(*sin));
+    *sa_size = sizeof(*sin);
+    sin->sin_family = AF_INET;
+    sin->sin_port   = port;
+    sin->sin_addr   = *((struct in_addr *)addr);
+}
+
+static void
+ipv4_anyaddr (struct sockaddr *sa, int *sa_size, int port)
+{
+    struct sockaddr_in *sin = (struct sockaddr_in *)sa;
+
+    memset (sin, 0, sizeof(*sin));
+    *sa_size = sizeof(*sin);
+    sin->sin_family = AF_INET;
+    sin->sin_port   = port;
+    sin->sin_addr.s_addr = INADDR_ANY;
+}
+
+/*
+ * AF_INET6 - aka IPv6 implementation
+ */
+
+#if defined(AF_INET6) && defined(HAVE_STRUCT_SOCKADDR_IN6)
+
+static krb5_error_code
+ipv6_sockaddr2addr (const struct sockaddr *sa, krb5_address *a)
+{
+    const struct sockaddr_in6 *sin6 = (const struct sockaddr_in6 *)sa;
+
+    if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
+	unsigned char buf[4];
+
+	a->addr_type      = KRB5_ADDRESS_INET;
+#ifndef IN6_ADDR_V6_TO_V4
+#define IN6_ADDR_V6_TO_V4(x) (&IN6_EXTRACT_V4ADDR(x))
+#endif
+	memcpy (buf, IN6_ADDR_V6_TO_V4(&sin6->sin6_addr), 4);
+	return krb5_data_copy(&a->address, buf, 4);
+    } else {
+	a->addr_type = KRB5_ADDRESS_INET6;
+	return krb5_data_copy(&a->address,
+			      &sin6->sin6_addr,
+			      sizeof(sin6->sin6_addr));
+    }
+}
+
+/*
+ * 
+ */
+
+static krb5_boolean
+ipv6_uninteresting (const struct sockaddr *sa)
+{
+#ifndef IN6_IS_ADDR_LOOPBACK
+#define IN6_IS_ADDR_LOOPBACK(x) IN6_IS_LOOPBACK(*x)
+#endif
+
+    const struct sockaddr_in6 *sin6 = (const struct sockaddr_in6 *)sa;
+    const struct in6_addr *in6 = (const struct in6_addr *)&sin6->sin6_addr;
+    
+    return IN6_IS_ADDR_LOOPBACK(in6)
+	|| IN6_IS_ADDR_LINKLOCAL(in6)
+	|| IN6_IS_ADDR_V4COMPAT(in6);
+}
+
+static void
+ipv6_h_addr2sockaddr(const char *addr,
+		     struct sockaddr *sa, int *sa_size, int port)
+{
+    struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sa;
+
+    memset (sin6, 0, sizeof(*sin6));
+    *sa_size = sizeof(*sin6);
+    sin6->sin6_family = AF_INET6;
+    sin6->sin6_port   = port;
+    sin6->sin6_addr   = *((struct in6_addr *)addr);
+}
+
+static void
+ipv6_anyaddr (struct sockaddr *sa, int *sa_size, int port)
+{
+    struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sa;
+
+    memset (sin6, 0, sizeof(*sin6));
+    *sa_size = sizeof(*sin6);
+    sin6->sin6_family = AF_INET;
+    sin6->sin6_port   = port;
+    sin6->sin6_addr   = in6addr_any;
+}
+
+#endif /* IPv6 */
+
+/*
+ * table
+ */
+
+static struct addr_operations at[] = {
+    {AF_INET,	KRB5_ADDRESS_INET, sizeof(struct sockaddr_in),
+     ipv4_sockaddr2addr, ipv4_uninteresting, ipv4_h_addr2sockaddr,
+     ipv4_anyaddr},
+#if defined(AF_INET6) && defined(HAVE_STRUCT_SOCKADDR_IN6)
+    {AF_INET6,	KRB5_ADDRESS_INET6, sizeof(struct sockaddr_in6),
+     ipv6_sockaddr2addr, ipv6_uninteresting, ipv6_h_addr2sockaddr,
+     ipv6_anyaddr}
+#endif
+};
+
+static int num_addrs = sizeof(at) / sizeof(at[0]);
+
+static size_t max_sockaddr_size = 0;
+
+/*
+ * generic functions
+ */
+
+static struct addr_operations *
+find_addr_type(int atype)
+{
+    struct addr_operations *a;
+
+    for (a = at; a < at + num_addrs; ++a)
+	if (atype == a->af)
+	    return a;
+    return NULL;
+}
+
+krb5_error_code
+krb5_sockaddr2address (const struct sockaddr *sa, krb5_address *addr)
+{
+    struct addr_operations *a = find_addr_type(sa->sa_family);
+    if (a == NULL)
+	return KRB5_PROG_ATYPE_NOSUPP;
+    return (*a->sockaddr2addr)(sa, addr);
+}
+
+size_t
+krb5_max_sockaddr_size ()
+{
+    if (max_sockaddr_size == 0) {
+	struct addr_operations *a;
+
+	for(a = at; a < at + num_addrs; ++a)
+	    max_sockaddr_size = max(max_sockaddr_size, a->max_sockaddr_size);
+    }
+    return max_sockaddr_size;
+}
+
+krb5_boolean
+krb5_sockaddr_uninteresting(const struct sockaddr *sa)
+{
+    struct addr_operations *a = find_addr_type(sa->sa_family);
+    if (a == NULL)
+	return TRUE;
+    return (*a->uninteresting)(sa);
+}
+
+krb5_error_code
+krb5_h_addr2sockaddr (int af,
+		      const char *addr, struct sockaddr *sa, int *sa_size,
+		      int port)
+{
+    struct addr_operations *a = find_addr_type(af);
+    if (a == NULL)
+	return KRB5_PROG_ATYPE_NOSUPP;
+    (*a->h_addr2sockaddr)(addr, sa, sa_size, port);
+    return 0;
+}
+
+krb5_error_code
+krb5_addr2sockaddr (krb5_address *addr,
+		    struct sockaddr *sa,
+		    int *sa_size,
+		    int port)
+{
+    struct addr_operations *a;
+
+    for (a = at; a < at + num_addrs; ++a)
+	if (addr->addr_type == a->atype)
+	    break;
+    if (a == at + num_addrs)
+	return KRB5_PROG_ATYPE_NOSUPP;
+
+    (*a->h_addr2sockaddr)(addr->address.data, sa, sa_size, port);
+    return 0;
+}
+
+krb5_error_code
+krb5_anyaddr (int af,
+	      struct sockaddr *sa,
+	      int *sa_size,
+	      int port)
+{
+    struct addr_operations *a;
+
+    for (a = at; a < at + num_addrs; ++a)
+	if (a->af == af)
+	    break;
+    if (a == at + num_addrs)
+	return KRB5_PROG_ATYPE_NOSUPP;
+
+    (*a->anyaddr)(sa, sa_size, port);
+    return 0;
+}