3004. [func] DNS64 reverse support. [RT #22769]

2025-09-01 15:05:23 +00:00 · 2011-01-07 04:31:39 +00:00
parent 26dffbd206
commit dc4fa197dd
9 changed files with 398 additions and 43 deletions
--- a/2
+++ b/2
@@ -1,3 +1,5 @@
+3004.	[func]		DNS64 reverse support. [RT #22769]
+
 3003.	[experimental]	Added update-policy match type "external",
 			enabliing named to defer the decision of whether to
 			allow a dynamic update to an external daemon.
--- a/bin/named/builtin.c
+++ b/bin/named/builtin.c
@@ -15,7 +15,7 @@
 * PERFORMANCE OF THIS SOFTWARE.
 */

-/* $Id: builtin.c,v 1.17 2010/08/03 23:46:39 tbox Exp $ */
+/* $Id: builtin.c,v 1.18 2011/01/07 04:31:38 marka Exp $ */

 /*! \file
 * \brief
@@ -47,6 +47,7 @@ static isc_result_t do_hostname_lookup(dns_sdblookup_t *lookup);
 static isc_result_t do_authors_lookup(dns_sdblookup_t *lookup);
 static isc_result_t do_id_lookup(dns_sdblookup_t *lookup);
 static isc_result_t do_empty_lookup(dns_sdblookup_t *lookup);
+static isc_result_t do_dns64_lookup(dns_sdblookup_t *lookup);

 /*
 * We can't use function pointers as the db_data directly
@@ -65,9 +66,179 @@ static builtin_t hostname_builtin = { do_hostname_lookup, NULL, NULL };
 static builtin_t authors_builtin = { do_authors_lookup, NULL, NULL };
 static builtin_t id_builtin = { do_id_lookup, NULL, NULL };
 static builtin_t empty_builtin = { do_empty_lookup, NULL, NULL };
+static builtin_t dns64_builtin = { do_dns64_lookup, NULL, NULL };

 static dns_sdbimplementation_t *builtin_impl;

+static const char hex[] = "0123456789abcdef";
+static const char HEX[] = "0123456789ABCDEF";
+
+static isc_result_t
+dns64_cname(const char *zone, const char *name, dns_sdblookup_t *lookup) {
+	size_t zlen, nlen, j;
+	const char *s;
+	unsigned char v[16];
+	unsigned int i;
+	char reverse[sizeof("123.123.123.123.in-addr.arpa.")];
+
+	/*
+	 * The sum the length of the relative name and the length of the zone
+	 * name for a IPv6 reverse lookup comes to 71.
+	 *
+	 * The reverse of 2001::10.0.0.1 (dns64 2001::/96) has a zone of
+	 * "0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.1.0.0.2.ip6.arpa"
+	 * and a name of "1.0.0.0.0.0.a.0".  The sum of the lengths of these
+	 * two strings is 71.
+	 *
+	 * The minimum length for a ip6.arpa zone name is 8.
+	 *
+	 * The length of name should always be odd as we are expecting
+	 * a series of nibbles.
+	 */
+	zlen = strlen(zone);
+	nlen = strlen(name);
+	if ((zlen + nlen) > 71U || zlen < 8U || (nlen % 2) != 1)
+		return (ISC_R_NOTFOUND);
+
+	/*
+	 * We assume the zone name is well formed.
+	 */
+
+	/*
+	 * XXXMPA We could check the dns64 suffix here if we need to.
+	 */
+	/*
+	 * Check that name is a series of nibbles.
+	 * Compute the byte values that correspond to the nibbles as we go.
+	 *
+	 * Shift the final result 4 bits, by setting 'i' to 1, if we if we
+	 * have a odd number of nibbles so that "must be zero" tests below
+	 * are byte aligned and we correctly return ISC_R_NOTFOUND or
+	 * ISC_R_SUCCESS.  We will not generate a CNAME in this case.
+	 */
+	i = (nlen % 4) == 1 ? 1 : 0;
+	j = nlen;
+	memset(v, 0, sizeof(v));
+	while (j >= 1) {
+		INSIST((i/2) < sizeof(v));
+		if (j > 1 && name[1] != '.')
+			return (ISC_R_NOTFOUND);
+		v[i/2] >>= 4;
+		if ((s = strchr(hex, name[0])) != NULL)
+			v[i/2] |= (s - hex) << 4;
+		else if ((s = strchr(HEX, name[0])) != NULL)
+			v[i/2] |= (s - HEX) << 4;
+		else
+			return (ISC_R_NOTFOUND);
+		if (j > 1)
+			j -= 2;
+		else
+			j -= 1;
+		name += 2;
+		i++;
+	}
+
+	/*
+ 	 * If we get here then we know name only consisted of nibbles.
+	 * Now we need to determine if the name exists or not and whether
+	 * it corresponds to a empty node in the zone or there should be
+	 * a CNAME.
+	 */
+	switch (zlen) {
+	case 24:	/* prefix len 32 */
+		/*
+		 * If the total length is not 71 then this is a empty node
+		 * so return success.
+		 */
+		if (nlen + zlen != 71U)
+			return (ISC_R_SUCCESS);
+		snprintf(reverse, sizeof(reverse), "%u.%u.%u.%u.in-addr.arpa.",
+			 v[8], v[9], v[10], v[11]);
+		break;
+	case 28:	/* prefix len 40 */
+		/*
+		 * The nibbles that map to this byte must be zero for 'name'
+		 * to exist in the zone.
+		 */
+		if (nlen > 11 && v[nlen/4 - 3] != 0)
+			return (ISC_R_NOTFOUND);
+		/*
+		 * If the total length is not 71 then this is a empty node
+		 * so return success.
+		 */
+		if (nlen + zlen != 71U)
+			return (ISC_R_SUCCESS);
+		snprintf(reverse, sizeof(reverse), "%u.%u.%u.%u.in-addr.arpa.",
+			 v[6], v[8], v[9], v[10]);
+		break;
+	case 32:	/* prefix len 48 */
+		/*
+		 * The nibbles that map to this byte must be zero for 'name'
+		 * to exist in the zone.
+		 */
+		if (nlen > 7 && v[nlen/4 - 2] != 0)
+			return (ISC_R_NOTFOUND);
+		/*
+		 * If the total length is not 71 then this is a empty node
+		 * so return success.
+		 */
+		if (nlen + zlen != 71U)
+			return (ISC_R_SUCCESS);
+		snprintf(reverse, sizeof(reverse), "%u.%u.%u.%u.in-addr.arpa.",
+			 v[5], v[6], v[8], v[9]);
+		break;
+	case 36:	/* prefix len 56 */
+		/*
+		 * The nibbles that map to this byte must be zero for 'name'
+		 * to exist in the zone.
+		 */
+		if (nlen > 3 && v[nlen/4 - 1] != 0)
+			return (ISC_R_NOTFOUND);
+		/*
+		 * If the total length is not 71 then this is a empty node
+		 * so return success.
+		 */
+		if (nlen + zlen != 71U)
+			return (ISC_R_SUCCESS);
+		snprintf(reverse, sizeof(reverse), "%u.%u.%u.%u.in-addr.arpa.",
+			 v[4], v[5], v[6], v[8]);
+		break;
+	case 40:	/* prefix len 64 */
+		/*
+		 * The nibbles that map to this byte must be zero for 'name'
+		 * to exist in the zone.
+		 */
+		if (v[nlen/4] != 0)
+			return (ISC_R_NOTFOUND);
+		/*
+		 * If the total length is not 71 then this is a empty node
+		 * so return success.
+		 */
+		if (nlen + zlen != 71U)
+			return (ISC_R_SUCCESS);
+		snprintf(reverse, sizeof(reverse), "%u.%u.%u.%u.in-addr.arpa.",
+			 v[3], v[4], v[5], v[6]);
+		break;
+	case 56:	/* prefix len 96 */
+		/*
+		 * If the total length is not 71 then this is a empty node
+		 * so return success.
+		 */
+		if (nlen + zlen != 71U)	
+			return (ISC_R_SUCCESS);
+		snprintf(reverse, sizeof(reverse), "%u.%u.%u.%u.in-addr.arpa.",
+			 v[0], v[1], v[2], v[3]);
+		break;
+	default:
+		/*
+		 * This should never be reached unless someone adds a
+		 * zone declaration with this internal type to named.conf.
+		 */
+		return (ISC_R_NOTFOUND);
+	}
+	return (dns_sdb_putrr(lookup, "CNAME", 600, reverse));
+}
+
 static isc_result_t
 builtin_lookup(const char *zone, const char *name, void *dbdata,
 	       dns_sdblookup_t *lookup)
@@ -78,6 +249,8 @@ builtin_lookup(const char *zone, const char *name, void *dbdata,

 	if (strcmp(name, "@") == 0)
 		return (b->do_lookup(lookup));
+	else if (b->do_lookup == do_dns64_lookup)
+		return (dns64_cname(zone, name, lookup));
 	else
 		return (ISC_R_NOTFOUND);
 }
@@ -175,6 +348,12 @@ do_id_lookup(dns_sdblookup_t *lookup) {
 		return (put_txt(lookup, ns_g_server->server_id));
 }

+static isc_result_t
+do_dns64_lookup(dns_sdblookup_t *lookup) {
+	UNUSED(lookup);
+	return (ISC_R_SUCCESS);
+}
+
 static isc_result_t
 do_empty_lookup(dns_sdblookup_t *lookup) {

@@ -222,7 +401,7 @@ builtin_create(const char *zone, int argc, char **argv,
 	UNUSED(zone);
 	UNUSED(driverdata);

-	if (strcmp(argv[0], "empty") == 0) {
+	if (strcmp(argv[0], "empty") == 0 || strcmp(argv[0], "dns64") == 0) {
 		if (argc != 3)
 			return (DNS_R_SYNTAX);
 	} else if (argc != 1)
@@ -236,7 +415,8 @@ builtin_create(const char *zone, int argc, char **argv,
 		*dbdata = &authors_builtin;
 	else if (strcmp(argv[0], "id") == 0)
 		*dbdata = &id_builtin;
-	else if (strcmp(argv[0], "empty") == 0) {
+	else if (strcmp(argv[0], "empty") == 0 ||
+		 strcmp(argv[0], "dns64") == 0) {
 		builtin_t *empty;
 		char *server;
 		char *contact;
@@ -248,7 +428,10 @@ builtin_create(const char *zone, int argc, char **argv,
 		server = isc_mem_strdup(ns_g_mctx, argv[1]);
 		contact = isc_mem_strdup(ns_g_mctx, argv[2]);
 		if (empty == NULL || server == NULL || contact == NULL) {
+			if (strcmp(argv[0], "empty") == 0)
 				*dbdata = &empty_builtin;
+			else
+				*dbdata = &dns64_builtin;
 			if (server != NULL)
 				isc_mem_free(ns_g_mctx, server);
 			if (contact != NULL)
@@ -256,7 +439,12 @@ builtin_create(const char *zone, int argc, char **argv,
 			if (empty != NULL)
 				isc_mem_put(ns_g_mctx, empty, sizeof (*empty));
 		} else {
-			memcpy(empty, &empty_builtin, sizeof (empty_builtin));
+			if (strcmp(argv[0], "empty") == 0)
+				memcpy(empty, &empty_builtin,
+				       sizeof (empty_builtin));
+			else
+				memcpy(empty, &dns64_builtin,
+				       sizeof (empty_builtin));
 			empty->server = server;
 			empty->contact = contact;
 			*dbdata = empty;
@@ -278,7 +466,7 @@ builtin_destroy(const char *zone, void *driverdata, void **dbdata) {
 	 */
 	if (*dbdata == &version_builtin || *dbdata == &hostname_builtin ||
 	    *dbdata == &authors_builtin || *dbdata == &id_builtin ||
-	    *dbdata == &empty_builtin)
+	    *dbdata == &empty_builtin || *dbdata == &dns64_builtin)
 		return;

 	isc_mem_free(ns_g_mctx, b->server);
@@ -308,3 +496,4 @@ void
 ns_builtin_deinit(void) {
 	dns_sdb_unregister(&builtin_impl);
 }
+
--- a/bin/named/named.conf.docbook
+++ b/bin/named/named.conf.docbook
@@ -17,7 +17,7 @@
 - PERFORMANCE OF THIS SOFTWARE.
 -->

-<!-- $Id: named.conf.docbook,v 1.47 2010/12/18 01:56:19 each Exp $ -->
+<!-- $Id: named.conf.docbook,v 1.48 2011/01/07 04:31:38 marka Exp $ -->
 <refentry>
  <refentryinfo>
    <date>Aug 13, 2004</date>
@@ -288,6 +288,17 @@ options {
 	dnssec-must-be-secure <replaceable>string</replaceable> <replaceable>boolean</replaceable>;
 	dnssec-accept-expired <replaceable>boolean</replaceable>;

+	dns64-server <replaceable>string</replaceable>;
+	dns64-contact <replaceable>string</replaceable>;
+	dns64 <replaceable>prefix</replaceable> {
+		clients { <replacable>acl</replacable>; };
+		exclude { <replacable>acl</replacable>; };
+		mapped { <replacable>acl</replacable>; };
+		break-dnssec <replaceable>boolean</replaceable>;
+		recursive-only <replaceable>boolean</replaceable>;
+		suffix <replaceable>ipv6_address</replaceable>;
+	};
+
 	empty-server <replaceable>string</replaceable>;
 	empty-contact <replaceable>string</replaceable>;
 	empty-zones-enable <replaceable>boolean</replaceable>;
@@ -463,6 +474,17 @@ view <replaceable>string</replaceable> <replaceable>optional_class</replaceable>
 	dnssec-must-be-secure <replaceable>string</replaceable> <replaceable>boolean</replaceable>;
 	dnssec-accept-expired <replaceable>boolean</replaceable>;

+	dns64-server <replaceable>string</replaceable>;
+	dns64-contact <replaceable>string</replaceable>;
+	dns64 <replaceable>prefix</replaceable> {
+		clients { <replacable>acl</replacable>; };
+		exclude { <replacable>acl</replacable>; };
+		mapped { <replacable>acl</replacable>; };
+		break-dnssec <replaceable>boolean</replaceable>;
+		recursive-only <replaceable>boolean</replaceable>;
+		suffix <replaceable>ipv6_address</replaceable>;
+	};
+
 	empty-server <replaceable>string</replaceable>;
 	empty-contact <replaceable>string</replaceable>;
 	empty-zones-enable <replaceable>boolean</replaceable>;
--- a/bin/named/server.c
+++ b/bin/named/server.c
@@ -15,7 +15,7 @@
 * PERFORMANCE OF THIS SOFTWARE.
 */

-/* $Id: server.c,v 1.594 2011/01/07 00:50:06 each Exp $ */
+/* $Id: server.c,v 1.595 2011/01/07 04:31:38 marka Exp $ */

 /*! \file */

@@ -1360,6 +1360,83 @@ dlzconfigure_callback(dns_view_t *view, dns_zone_t *zone) {
 }
 #endif

+static isc_result_t
+dns64_reverse(dns_view_t *view, isc_mem_t *mctx, isc_netaddr_t *na,
+	      unsigned int prefixlen, const char *server,
+	      const char *contact)
+{
+	char *cp;
+	char reverse[48+sizeof("ip6.arpa.")];
+	const char *dns64_dbtype[4] = { "_builtin", "dns64", ".", "." };
+	const char *sep = ": view ";
+	const char *viewname = view->name;
+	const unsigned char *s6;
+	dns_fixedname_t fixed;
+	dns_name_t *name;
+	dns_zone_t *zone = NULL;
+	int dns64_dbtypec = 4;
+	isc_buffer_t b;
+	isc_result_t result;
+
+	REQUIRE(prefixlen == 32 || prefixlen == 40 || prefixlen == 48 ||
+		prefixlen == 56 || prefixlen == 64 || prefixlen == 96);
+
+	if (!strcmp(viewname, "_default")) {
+		sep = "";
+		viewname = "";
+	}
+
+	/*
+	 * Construct the reverse name of the zone.
+	 */
+	cp = reverse;
+	s6 = na->type.in6.s6_addr;
+	while (prefixlen > 0) {
+		prefixlen -= 8;
+		sprintf(cp, "%x.%x.", s6[prefixlen/8] & 0xf,
+			(s6[prefixlen/8] >> 4) & 0xf);
+		cp += 4;
+	}
+	strcat(cp, "ip6.arpa.");
+
+	/*
+	 * Create the actual zone.
+	 */
+	if (server != NULL)
+		dns64_dbtype[2] = server;
+	if (contact != NULL)
+		dns64_dbtype[3] = contact;
+	dns_fixedname_init(&fixed);
+	name = dns_fixedname_name(&fixed);
+	isc_buffer_init(&b, reverse, strlen(reverse));
+	isc_buffer_add(&b, strlen(reverse));
+	CHECK(dns_name_fromtext(name, &b, dns_rootname, 0, NULL));
+	CHECK(dns_zone_create(&zone, mctx));
+	CHECK(dns_zone_setorigin(zone, name));
+	dns_zone_setview(zone, view);
+	CHECK(dns_zonemgr_managezone(ns_g_server->zonemgr, zone));
+	dns_zone_setclass(zone, view->rdclass);
+	dns_zone_settype(zone, dns_zone_master);
+	dns_zone_setstats(zone, ns_g_server->zonestats);
+	CHECK(dns_zone_setdbtype(zone, dns64_dbtypec, dns64_dbtype));
+	if (view->queryacl != NULL)
+		dns_zone_setqueryacl(zone, view->queryacl);
+	if (view->queryonacl != NULL)
+		dns_zone_setqueryonacl(zone, view->queryonacl);
+	dns_zone_setdialup(zone, dns_dialuptype_no);
+	dns_zone_setnotifytype(zone, dns_notifytype_no);
+	dns_zone_setoption(zone, DNS_ZONEOPT_NOCHECKNS, ISC_TRUE);
+	CHECK(setquerystats(zone, mctx, ISC_FALSE));	/* XXXMPA */
+	CHECK(dns_view_addzone(view, zone));
+	isc_log_write(ns_g_lctx, NS_LOGCATEGORY_GENERAL, NS_LOGMODULE_SERVER,
+		      ISC_LOG_INFO, "dns64 reverse zone%s%s: %s", sep,
+		      viewname, reverse);
+
+cleanup:
+	if (zone != NULL)
+		dns_zone_detach(&zone);
+	return (result);
+}

 /*
 * Configure 'view' according to 'vconfig', taking defaults from 'config'
@@ -1707,6 +1784,22 @@ configure_view(dns_view_t *view, cfg_parser_t* parser,
 		const cfg_listelt_t *element;
 		isc_netaddr_t na, suffix, *sp;
 		unsigned int prefixlen;
+		const char *server, *contact;
+		const cfg_obj_t *myobj;
+
+		myobj = NULL;
+		result = ns_config_get(maps, "dns64-server", &myobj);
+		if (result == ISC_R_SUCCESS)
+			server = cfg_obj_asstring(myobj);
+		else
+			server = NULL;
+
+		myobj = NULL;
+		result = ns_config_get(maps, "dns64-contact", &myobj);
+		if (result == ISC_R_SUCCESS)
+			contact = cfg_obj_asstring(myobj);
+		else
+			contact = NULL;

 		for (element = cfg_list_first(obj);
 		     element != NULL;
@@ -1774,6 +1867,10 @@ configure_view(dns_view_t *view, cfg_parser_t* parser,
 				goto cleanup;
 			dns_dns64_append(&view->dns64, dns64);
 			view->dns64cnt++;
+			result = dns64_reverse(view, mctx, &na, prefixlen,
+					       server, contact);
+			if (result != ISC_R_SUCCESS)
+				goto cleanup;
 			if (clients != NULL)
 				dns_acl_detach(&clients);
 			if (mapped != NULL)
--- a/bin/tests/system/dns64/ns2/named.conf
+++ b/bin/tests/system/dns64/ns2/named.conf
@@ -14,7 +14,7 @@
 * PERFORMANCE OF THIS SOFTWARE.
 */

-/* $Id: named.conf,v 1.2 2010/12/08 02:46:16 marka Exp $ */
+/* $Id: named.conf,v 1.3 2011/01/07 04:31:38 marka Exp $ */

 // NS2

@@ -49,6 +49,13 @@ options {
                suffix ::;
        };

+	dns64-server "dns64.example.net.";
+	dns64-contact "hostmaster.example.net.";
+	dns64 2001:32::/32 { clients { 10.53.0.6; }; };
+	dns64 2001:40::/40 { clients { 10.53.0.6; }; };
+	dns64 2001:48::/48 { clients { 10.53.0.6; }; };
+	dns64 2001:56::/56 { clients { 10.53.0.6; }; };
+	dns64 2001:64::/64 { clients { 10.53.0.6; }; };
 };

 zone "." {
--- a/bin/tests/system/dns64/tests.sh
+++ b/bin/tests/system/dns64/tests.sh
@@ -14,7 +14,7 @@
 # OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 # PERFORMANCE OF THIS SOFTWARE.

-# $Id: tests.sh,v 1.2 2010/12/08 02:46:15 marka Exp $
+# $Id: tests.sh,v 1.3 2011/01/07 04:31:38 marka Exp $

 SYSTEMTESTTOP=..
 . $SYSTEMTESTTOP/conf.sh
@@ -1244,5 +1244,32 @@ n=`expr $n + 1`
 if [ $ret != 0 ]; then echo "I:failed"; fi
 status=`expr $status + $ret`

+echo "I: checking reverse mapping ($n)"
+ret=0
+$DIG $DIGOPTS -x 2001:aaaa::10.0.0.1 @10.53.0.2 > dig.out.ns2.test$n || ret=1
+grep -i "CNAME.1.0.0.10.IN-ADDR.ARPA.$" dig.out.ns2.test$n > /dev/null || ret=1
+n=`expr $n + 1`
+if [ $ret != 0 ]; then echo "I:failed"; fi
+status=`expr $status + $ret`
+
+list=`$DIG $DIGOPTS -b 10.53.0.6 @10.53.0.2 +short aaaa a-only.example | sort`
+for a in $list
+do
+	ret=0
+	echo "I: checking reverse mapping of $a ($n)"
+	$DIG $DIGOPTS -x $a @10.53.0.2 > dig.out.ns2.test$n || ret=1
+	grep -i "CNAME.5.3.2.1.IN-ADDR.ARPA." dig.out.ns2.test$n > /dev/null || ret=1
+	n=`expr $n + 1`
+	if [ $ret != 0 ]; then echo "I:failed"; fi
+	status=`expr $status + $ret`
+done
+
+echo "I: checking dns64-server and dns64-contact ($n)"
+$DIG $DIGOPTS soa 0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.a.a.a.a.1.0.0.2.ip6.arpa @10.53.0.2 > dig.out.ns2.test$n || ret=1
+grep "SOA.dns64.example.net..hostmaster.example.net." dig.out.ns2.test$n > /dev/null || ret=1
+n=`expr $n + 1`
+if [ $ret != 0 ]; then echo "I:failed"; fi
+status=`expr $status + $ret`
+
 echo "I:exit status: $status"
 exit $status
--- a/doc/arm/Bv9ARM-book.xml
+++ b/doc/arm/Bv9ARM-book.xml
@@ -18,7 +18,7 @@
 - PERFORMANCE OF THIS SOFTWARE.
 -->

-<!-- File: $Id: Bv9ARM-book.xml,v 1.474 2011/01/06 23:24:38 each Exp $ -->
+<!-- File: $Id: Bv9ARM-book.xml,v 1.475 2011/01/07 04:31:38 marka Exp $ -->
 <book xmlns:xi="http://www.w3.org/2001/XInclude">
  <title>BIND 9 Administrator Reference Manual</title>

@@ -5142,6 +5142,8 @@ badresp:1,adberr:0,findfail:0,valfail:0]
 	<optional> recursion-only <replaceable>yes_or_no</replaceable>; </optional>
 	<optional> break-dnssec <replaceable>yes_or_no</replaceable>; </optional>
    }; </optional>;
+    <optional> dns64-server <replaceable>name</replaceable> </optional>
+    <optional> dns64-contact <replaceable>name</replaceable> </optional>
    <optional> preferred-glue ( <replaceable>A</replaceable> | <replaceable>AAAA</replaceable> | <replaceable>NONE</replaceable> ); </optional>
    <optional> edns-udp-size <replaceable>number</replaceable>; </optional>
    <optional> max-udp-size <replaceable>number</replaceable>; </optional>
@@ -5763,6 +5765,16 @@ options {
 		Compatible IPv6 prefixes have lengths of 32, 40, 48, 56,
 		64 and 96 as per RFC 6052.
 	      </para>
+	      <para>
+		Additionally a reverse IP6.ARPA zone will be created for
+		the prefix to provide a mapping from the IP6.ARPA names
+		to the corresponding IN-ADDR.ARPA names using synthesized
+		CNAMEs.  <command>dns64-server</command> and
+		<command>dns64-contact</command> can be used to specify
+		the name of the server and contact for the zones. These
+		are settable at the view / options level.  These are
+		not settable on a per-prefix basis.
+	      </para>
 	      <para>
 		Each <command>dns64</command> supports a optional
 		<command>clients</command> acl which defines which clients
--- a/lib/bind9/check.c
+++ b/lib/bind9/check.c
@@ -15,7 +15,7 @@
 * PERFORMANCE OF THIS SOFTWARE.
 */

-/* $Id: check.c,v 1.123 2010/12/16 09:51:29 jinmei Exp $ */
+/* $Id: check.c,v 1.124 2011/01/07 04:31:39 marka Exp $ */

 /*! \file */

@@ -696,6 +696,12 @@ check_options(const cfg_obj_t *options, isc_log_t *logctx, isc_mem_t *mctx) {
 	{ "statistics-interval", 60, 28 * 24 * 60 },	/* 28 days */
 	};

+	static const char *server_contact[] = {
+		"empty-server", "empty-contact",
+		"dns64-server", "dns64-contact",
+		NULL
+	};
+
 	/*
 	 * Check that fields specified in units of time other than seconds
 	 * have reasonable values.
@@ -937,39 +943,30 @@ check_options(const cfg_obj_t *options, isc_log_t *logctx, isc_mem_t *mctx) {
 			isc_symtab_destroy(&symtab);
 	}

+	/*
+	 * Check server/contacts for syntactic validity.
+	 */
+	for (i= 0; server_contact[i] != NULL; i++) {
+		obj = NULL;
+		(void)cfg_map_get(options, server_contact[i], &obj);
+		if (obj != NULL) {
+			str = cfg_obj_asstring(obj);
+			isc_buffer_init(&b, str, strlen(str));
+			isc_buffer_add(&b, strlen(str));
+			tresult = dns_name_fromtext(dns_fixedname_name(&fixed),
+						    &b, dns_rootname, 0, NULL);
+			if (tresult != ISC_R_SUCCESS) {
+				cfg_obj_log(obj, logctx, ISC_LOG_ERROR,
+					    "%s: invalid name '%s'",
+					    server_contact[i], str);
+				result = ISC_R_FAILURE;
+			}
+		}
+	}
+
 	/*
 	 * Check empty zone configuration.
 	 */
-	obj = NULL;
-	(void)cfg_map_get(options, "empty-server", &obj);
-	if (obj != NULL) {
-		str = cfg_obj_asstring(obj);
-		isc_buffer_init(&b, str, strlen(str));
-		isc_buffer_add(&b, strlen(str));
-		tresult = dns_name_fromtext(dns_fixedname_name(&fixed), &b,
-					    dns_rootname, 0, NULL);
-		if (tresult != ISC_R_SUCCESS) {
-			cfg_obj_log(obj, logctx, ISC_LOG_ERROR,
-				    "empty-server: invalid name '%s'", str);
-			result = ISC_R_FAILURE;
-		}
-	}
-
-	obj = NULL;
-	(void)cfg_map_get(options, "empty-contact", &obj);
-	if (obj != NULL) {
-		str = cfg_obj_asstring(obj);
-		isc_buffer_init(&b, str, strlen(str));
-		isc_buffer_add(&b, strlen(str));
-		tresult = dns_name_fromtext(dns_fixedname_name(&fixed), &b,
-					    dns_rootname, 0, NULL);
-		if (tresult != ISC_R_SUCCESS) {
-			cfg_obj_log(obj, logctx, ISC_LOG_ERROR,
-				    "empty-contact: invalid name '%s'", str);
-			result = ISC_R_FAILURE;
-		}
-	}
-
 	obj = NULL;
 	(void)cfg_map_get(options, "disable-empty-zone", &obj);
 	for (element = cfg_list_first(obj);
--- a/lib/isccfg/namedconf.c
+++ b/lib/isccfg/namedconf.c
@@ -15,7 +15,7 @@
 * PERFORMANCE OF THIS SOFTWARE.
 */

-/* $Id: namedconf.c,v 1.129 2011/01/06 23:24:39 each Exp $ */
+/* $Id: namedconf.c,v 1.130 2011/01/07 04:31:39 marka Exp $ */

 /*! \file */

@@ -1090,6 +1090,8 @@ view_clauses[] = {
 	  CFG_CLAUSEFLAG_MULTI },
 	{ "disable-empty-zone", &cfg_type_astring, CFG_CLAUSEFLAG_MULTI },
 	{ "dns64", &cfg_type_dns64, CFG_CLAUSEFLAG_MULTI },
+	{ "dns64-server", &cfg_type_astring, 0 },
+	{ "dns64-contact", &cfg_type_astring, 0 },
 	{ "dnssec-accept-expired", &cfg_type_boolean, 0 },
 	{ "dnssec-enable", &cfg_type_boolean, 0 },
 	{ "dnssec-lookaside", &cfg_type_lookaside, CFG_CLAUSEFLAG_MULTI },