1412. [func] You can now specify servers to be tried if a nameserver

                       has IPv6 address and you only support IPv4 or the
                       reverse. See dual-stack-servers.

CHANGES

+1412.	[func]		You can now specify servers to be tried if a nameserver
+			has IPv6 address and you only support IPv4 or the
+			reverse. See dual-stack-servers.
+			
 1411.	[bug]		empty nodes should stop wildcard matches. [RT #4802]
 
 1410.	[func]		handle records that live in the parent zone, e.g. DS.

bin/named/main.c

@@ -15,7 +15,7 @@
  * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: main.c,v 1.128 2002/05/03 05:28:19 marka Exp $ */
+/* $Id: main.c,v 1.129 2003/01/16 03:59:23 marka Exp $ */
 
 #include <config.h>
 
@@ -329,14 +329,31 @@ static void
 parse_command_line(int argc, char *argv[]) {
 	int ch;
 	int port;
+	isc_boolean_t disable6 = ISC_FALSE;
+	isc_boolean_t disable4 = ISC_FALSE;
 
 	save_command_line(argc, argv);
 
 	isc_commandline_errprint = ISC_FALSE;
 	while ((ch = isc_commandline_parse(argc, argv,
-					   "c:C:d:fgi:lm:n:N:p:P:st:u:vx:")) !=
-	       -1) {
+			           "46c:C:d:fgi:lm:n:N:p:P:st:u:vx:")) != -1) {
 		switch (ch) {
+		case '4':
+			if (disable4)
+				ns_main_earlyfatal("cannot specify -4 and -6");
+			if (isc_net_probeipv4() != ISC_R_SUCCESS)
+				ns_main_earlyfatal("IPv4 not supported by OS");
+			isc_net_disableipv6();
+			disable6 = ISC_TRUE;
+			break;
+		case '6':
+			if (disable6)
+				ns_main_earlyfatal("cannot specify -4 and -6");
+			if (isc_net_probeipv6() != ISC_R_SUCCESS)
+				ns_main_earlyfatal("IPv6 not supported by OS");
+			isc_net_disableipv4();
+			disable4 = ISC_TRUE;
+			break;
 		case 'c':
 			ns_g_conffile = isc_commandline_argument;
 			lwresd_g_conffile = isc_commandline_argument;

bin/named/named.docbook

@@ -16,7 +16,7 @@
  - WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 -->
 
-<!-- $Id: named.docbook,v 1.5 2001/06/10 13:57:51 tale Exp $ -->
+<!-- $Id: named.docbook,v 1.6 2003/01/16 03:59:23 marka Exp $ -->
 
 <refentry>
   <refentryinfo>
@@ -37,6 +37,8 @@
   <refsynopsisdiv>
     <cmdsynopsis>
       <command>named</command>
+      <arg><option>-4</option></arg>
+      <arg><option>-6</option></arg>
       <arg><option>-c <replaceable class="parameter">config-file</replaceable></option></arg>
       <arg><option>-d <replaceable class="parameter">debug-level</replaceable></option></arg>
       <arg><option>-f</option></arg>
@@ -70,6 +72,27 @@
     <title>OPTIONS</title>
 
     <variablelist>
+      <varlistentry>
+	<term>-4</term>
+	<listitem>
+	  <para>
+		Use IPv4 only even if the host machine is capable of IPv6.
+		<option>-4</option> and <option>-6</option> are mutually
+		exclusive.
+          </para>
+	</listitem>
+      </varlistentry>
+
+      <varlistentry>
+	<term>-6</term>
+	<listitem>
+	  <para>
+		Use IPv6 only even if the host machine is capable of IPv4.
+		<option>-4</option> and <option>-6</option> are mutually
+		exclusive.
+          </para>
+	</listitem>
+      </varlistentry>
       <varlistentry>
 	<term>-c <replaceable class="parameter">config-file</replaceable></term>
 	<listitem>

bin/named/server.c

@@ -15,7 +15,7 @@
  * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: server.c,v 1.391 2002/11/27 09:52:45 marka Exp $ */
+/* $Id: server.c,v 1.392 2003/01/16 03:59:23 marka Exp $ */
 
 #include <config.h>
 
@@ -137,6 +137,10 @@ static isc_result_t
 configure_forward(cfg_obj_t *config, dns_view_t *view, dns_name_t *origin,
 		  cfg_obj_t *forwarders, cfg_obj_t *forwardtype);
 
+static isc_result_t
+configure_alternates(cfg_obj_t *config, dns_view_t *view,
+		     cfg_obj_t *alternates);
+
 static isc_result_t
 configure_zone(cfg_obj_t *config, cfg_obj_t *zconfig, cfg_obj_t *vconfig,
 	       isc_mem_t *mctx, dns_view_t *view,
@@ -558,6 +562,7 @@ configure_view(dns_view_t *view, cfg_obj_t *config, cfg_obj_t *vconfig,
 	cfg_obj_t *voptions = NULL;
 	cfg_obj_t *forwardtype;
 	cfg_obj_t *forwarders;
+	cfg_obj_t *alternates;
 	cfg_obj_t *zonelist;
 	cfg_obj_t *obj;
 	cfg_listelt_t *element;
@@ -748,6 +753,14 @@ configure_view(dns_view_t *view, cfg_obj_t *config, cfg_obj_t *vconfig,
 		CHECK(configure_forward(config, view, dns_rootname, 
 					forwarders, forwardtype));
 
+	/*
+	 * Dual Stack Servers.
+	 */
+	alternates = NULL;
+	(void)ns_config_get(maps, "dual-stack-servers", &alternates);
+	if (alternates != NULL)
+		CHECK(configure_alternates(config, view, alternates));
+
 	/*
 	 * We have default hints for class IN if we need them.
 	 */
@@ -987,6 +1000,91 @@ configure_hints(dns_view_t *view, const char *filename) {
 	return (result);
 }
 
+static isc_result_t
+configure_alternates(cfg_obj_t *config, dns_view_t *view,
+		     cfg_obj_t *alternates)
+{
+	cfg_obj_t *portobj;
+	cfg_obj_t *addresses;
+	cfg_listelt_t *element;
+	isc_result_t result = ISC_R_SUCCESS;
+	in_port_t port;
+
+	/*
+	 * Determine which port to send requests to.
+	 */
+	if (ns_g_lwresdonly && ns_g_port != 0)
+		port = ns_g_port;
+	else
+		CHECKM(ns_config_getport(config, &port), "port");
+
+	if (alternates != NULL) {
+		portobj = cfg_tuple_get(alternates, "port");
+		if (cfg_obj_isuint32(portobj)) {
+			isc_uint32_t val = cfg_obj_asuint32(portobj);
+			if (val > ISC_UINT16_MAX) {
+				cfg_obj_log(portobj, ns_g_lctx, ISC_LOG_ERROR,
+					    "port '%u' out of range", val);
+				return (ISC_R_RANGE);
+			}
+			port = (in_port_t) val;
+		}
+	}
+
+	addresses = NULL;
+	if (alternates != NULL)
+		addresses = cfg_tuple_get(alternates, "addresses");
+
+	for (element = cfg_list_first(addresses);
+	     element != NULL;
+	     element = cfg_list_next(element))
+	{
+		cfg_obj_t *alternate = cfg_listelt_value(element);
+		isc_sockaddr_t sa;
+
+		if (!cfg_obj_issockaddr(alternate)) {
+			dns_fixedname_t fixed;
+			dns_name_t *name;
+			char *str = cfg_obj_asstring(cfg_tuple_get(alternate,
+								   "name"));
+			isc_buffer_t buffer;
+			in_port_t myport = port;
+
+			isc_buffer_init(&buffer, str, strlen(str));
+			isc_buffer_add(&buffer, strlen(str));
+			dns_fixedname_init(&fixed);
+			name = dns_fixedname_name(&fixed);
+			CHECK(dns_name_fromtext(name, &buffer, dns_rootname,
+						ISC_FALSE, NULL));
+
+			portobj = cfg_tuple_get(alternates, "port");
+			if (cfg_obj_isuint32(portobj)) {
+				isc_uint32_t val = cfg_obj_asuint32(portobj);
+				if (val > ISC_UINT16_MAX) {
+					cfg_obj_log(portobj, ns_g_lctx,
+						    ISC_LOG_ERROR,
+						    "port '%u' out of range",
+						     val);
+					return (ISC_R_RANGE);
+				}
+				myport = (in_port_t) val;
+			}
+			CHECK(dns_resolver_addalternate(view->resolver, NULL,
+							name, myport));
+			continue;
+		}
+
+		sa = *cfg_obj_assockaddr(alternate);
+		if (isc_sockaddr_getport(&sa) == 0)
+			isc_sockaddr_setport(&sa, port);
+		CHECK(dns_resolver_addalternate(view->resolver, &sa,
+						NULL, 0));
+	}
+
+ cleanup:
+	return (result);
+}
+
 static isc_result_t
 configure_forward(cfg_obj_t *config, dns_view_t *view, dns_name_t *origin,
 		  cfg_obj_t *forwarders, cfg_obj_t *forwardtype)

doc/arm/Bv9ARM-book.xml

@@ -2,7 +2,7 @@
 <!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.0//EN"
                "http://www.oasis-open.org/docbook/xml/4.0/docbookx.dtd">
 
-<!-- File: $Id: Bv9ARM-book.xml,v 1.211 2003/01/13 04:24:27 marka Exp $ -->
+<!-- File: $Id: Bv9ARM-book.xml,v 1.212 2003/01/16 03:59:24 marka Exp $ -->
 
 <book>
 <title>BIND 9 Administrator Reference Manual</title>
@@ -2717,6 +2717,7 @@ statement in the <filename>named.conf</filename> file:</para>
     <optional> maintain-ixfr-base <replaceable>yes_or_no</replaceable>; </optional>
     <optional> forward ( <replaceable>only</replaceable> | <replaceable>first</replaceable> ); </optional>
     <optional> forwarders { <replaceable>ip_addr</replaceable> <optional>port <replaceable>ip_port</replaceable></optional> ; <optional> <replaceable>ip_addr</replaceable> <optional>port <replaceable>ip_port</replaceable></optional> ; ... </optional> }; </optional>
+    <optional> dual-stack-servers <optional>port <replaceable>ip_port</replaceable></optional> { ( <replaceable>domain_name</replaceable> <optional>port <replaceable>ip_port</replaceable></optional> | <replaceable>ip_addr</replaceable> <optional>port <replaceable>ip_port</replaceable></optional> ) ; ... }; </optional>
     <optional> check-names ( <replaceable>master</replaceable> | <replaceable>slave</replaceable> | <replaceable> response</replaceable> )( <replaceable>warn</replaceable> | <replaceable>fail</replaceable> | <replaceable>ignore</replaceable> ); </optional>
     <optional> allow-notify { <replaceable>address_match_list</replaceable> }; </optional>
     <optional> allow-query { <replaceable>address_match_list</replaceable> }; </optional>
@@ -3303,6 +3304,23 @@ or have a different <command>forward only/first</command> behavior,
 or not forward at all, see <xref linkend="zone_statement_grammar"/>.</para>
 </sect3>
 
+<sect3><title>6 to 4 Servers</title>
+<para>6 to 4 servers are used as servers of last resort to work around
+problems in reachability due the lack of support for either IPv4 or IPv6
+on the host machine.</para>
+
+<variablelist>
+<varlistentry><term><command>dual-stack-servers</command></term>
+<listitem><para>Specifies host names / addresses of machines with access to
+both IPv4 and IPv6 transports. If a hostname is used the server must be able
+to resolve the name using only the transport it has.  If the machine is dual
+stacked then the <command>dual-stack-servers</command> have no effect unless
+access to a transport has been disabled on the command line
+(e.g. <command>named -4</command>).</para></listitem>
+</varlistentry>
+</variablelist>
+</sect3>
+
 <sect3 id="access_control"><title>Access Control</title>
 
 <para>Access to the server can be restricted based on the IP address

lib/bind9/check.c

@@ -15,7 +15,7 @@
  * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: check.c,v 1.33 2002/04/26 00:40:28 marka Exp $ */
+/* $Id: check.c,v 1.34 2003/01/16 03:59:24 marka Exp $ */
 
 #include <config.h>
 
@@ -143,6 +143,66 @@ check_order(cfg_obj_t *options, isc_log_t *logctx) {
 	return (result);
 }
 
+static isc_result_t
+check_dual_stack(cfg_obj_t *options, isc_log_t *logctx) {
+	cfg_listelt_t *element;
+	cfg_obj_t *alternates = NULL;
+	cfg_obj_t *value;
+	cfg_obj_t *obj;
+	char *str;
+	dns_fixedname_t fixed;
+	dns_name_t *name;
+	isc_buffer_t buffer;
+	isc_result_t result = ISC_R_SUCCESS;
+	isc_result_t tresult;
+
+	(void)cfg_map_get(options, "dual-stack-servers", &alternates);
+
+	if (alternates == NULL)
+		return (ISC_R_SUCCESS);
+
+	obj = cfg_tuple_get(alternates, "port");
+	if (cfg_obj_isuint32(obj)) {
+		isc_uint32_t val = cfg_obj_asuint32(obj);
+		if (val > ISC_UINT16_MAX) {
+			cfg_obj_log(obj, logctx, ISC_LOG_ERROR,
+				    "port '%u' out of range", val);
+			result = ISC_R_FAILURE;
+		}
+	}
+	obj = cfg_tuple_get(alternates, "addresses");
+	for (element = cfg_list_first(obj);
+	     element != NULL;
+	     element = cfg_list_next(element)) {
+		value = cfg_listelt_value(element);
+		if (cfg_obj_issockaddr(value))
+			continue;
+		obj = cfg_tuple_get(value, "name");
+		str = cfg_obj_asstring(obj);
+		isc_buffer_init(&buffer, str, strlen(str));
+		isc_buffer_add(&buffer, strlen(str));
+		dns_fixedname_init(&fixed);
+		name = dns_fixedname_name(&fixed);
+		tresult = dns_name_fromtext(name, &buffer, dns_rootname,
+					   ISC_FALSE, NULL);
+		if (tresult != ISC_R_SUCCESS) {
+			cfg_obj_log(obj, logctx, ISC_LOG_ERROR,
+				    "bad name '%s'", str);
+			result = ISC_R_FAILURE;
+		}
+		obj = cfg_tuple_get(value, "port");
+		if (cfg_obj_isuint32(obj)) {
+			isc_uint32_t val = cfg_obj_asuint32(obj);
+			if (val > ISC_UINT16_MAX) {
+				cfg_obj_log(obj, logctx, ISC_LOG_ERROR,
+					    "port '%u' out of range", val);
+				result = ISC_R_FAILURE;
+			}
+		}
+	}
+	return (result);
+}
+
 static isc_result_t
 check_forward(cfg_obj_t *options, isc_log_t *logctx) {
 	cfg_obj_t *forward = NULL;
@@ -697,6 +757,19 @@ check_viewconf(cfg_obj_t *config, cfg_obj_t *vconfig, dns_rdataclass_t vclass,
 		if (check_forward(vconfig, logctx) != ISC_R_SUCCESS)
 			result = ISC_R_FAILURE;
 	}
+	/*
+	 * Check that dual-stack-servers is reasonable.
+	 */
+	if (vconfig == NULL) {
+		cfg_obj_t *options = NULL;
+		(void)cfg_map_get(config, "options", &options);
+		if (options != NULL)
+			if (check_dual_stack(options, logctx) != ISC_R_SUCCESS)
+				result = ISC_R_FAILURE;
+	} else {
+		if (check_dual_stack(vconfig, logctx) != ISC_R_SUCCESS)
+			result = ISC_R_FAILURE;
+	}
 
 	/*
 	 * Check that rrset-order is reasonable.
@@ -755,6 +828,10 @@ bind9_check_namedconf(cfg_obj_t *config, isc_log_t *logctx, isc_mem_t *mctx) {
 
 	(void)cfg_map_get(config, "view", &views);
 
+	if (views != NULL && options != NULL)
+		if (check_dual_stack(options, logctx) != ISC_R_SUCCESS)
+			result = ISC_R_FAILURE;
+
 	if (views == NULL) {
 		if (check_viewconf(config, NULL, dns_rdataclass_in,
 				   logctx, mctx) != ISC_R_SUCCESS)

lib/dns/include/dns/resolver.h

@@ -15,7 +15,7 @@
  * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: resolver.h,v 1.35 2001/10/29 19:02:46 gson Exp $ */
+/* $Id: resolver.h,v 1.36 2003/01/16 03:59:25 marka Exp $ */
 
 #ifndef DNS_RESOLVER_H
 #define DNS_RESOLVER_H 1
@@ -359,6 +359,18 @@ dns_resolver_nrunning(dns_resolver_t *resolver);
  * can continue even though a fetch has been canceled.
  */
 
+isc_result_t
+dns_resolver_addalternate(dns_resolver_t *resolver, isc_sockaddr_t *alt,
+			  dns_name_t *name, in_port_t port);
+/*
+ * Add alternate addresses to be tried in the event that the nameservers
+ * for a zone are not available in the address families supported by the
+ * operating system.
+ *
+ * Require:
+ * 	only one of 'name' or 'alt' to be valid.
+ */
+
 ISC_LANG_ENDDECLS
 
 #endif /* DNS_RESOLVER_H */

lib/isc/include/isc/result.h

@@ -15,7 +15,7 @@
  * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: result.h,v 1.59 2001/11/30 01:02:17 gson Exp $ */
+/* $Id: result.h,v 1.60 2003/01/16 03:59:26 marka Exp $ */
 
 #ifndef ISC_RESULT_H
 #define ISC_RESULT_H 1
@@ -80,11 +80,12 @@
 #define ISC_R_CONNECTIONRESET		54	/* connection reset */
 #define ISC_R_SOFTQUOTA			55	/* soft quota reached */
 #define ISC_R_BADNUMBER			56	/* not a valid number */
+#define ISC_R_DISABLED			57	/* disabled */
 
 /*
  * Not a result code: the number of results.
  */
-#define ISC_R_NRESULTS 			57
+#define ISC_R_NRESULTS 			58
 
 ISC_LANG_BEGINDECLS
 

lib/isc/result.c

@@ -15,7 +15,7 @@
  * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: result.c,v 1.59 2001/11/30 01:02:14 gson Exp $ */
+/* $Id: result.c,v 1.60 2003/01/16 03:59:25 marka Exp $ */
 
 #include <config.h>
 
@@ -94,7 +94,8 @@ static const char *text[ISC_R_NRESULTS] = {
 	"operation in progress",		/* 53 */
 	"connection reset",			/* 54 */
 	"soft quota reached",			/* 55 */
-	"not a valid number"			/* 56 */
+	"not a valid number",			/* 56 */
+	"disabled"				/* 57 */
 };
 
 #define ISC_RESULT_RESULTSET			2

lib/isc/unix/include/isc/net.h

@@ -15,7 +15,7 @@
  * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: net.h,v 1.36 2002/10/29 04:40:25 marka Exp $ */
+/* $Id: net.h,v 1.37 2003/01/16 03:59:27 marka Exp $ */
 
 #ifndef ISC_NET_H
 #define ISC_NET_H 1
@@ -245,6 +245,7 @@ isc_net_probeipv4(void);
  *
  *	ISC_R_SUCCESS		IPv4 is supported.
  *	ISC_R_NOTFOUND		IPv4 is not supported.
+ *	ISC_R_DISABLED		IPv4 is disabled.
  *	ISC_R_UNEXPECTED
  */
 
@@ -257,6 +258,7 @@ isc_net_probeipv6(void);
  *
  *	ISC_R_SUCCESS		IPv6 is supported.
  *	ISC_R_NOTFOUND		IPv6 is not supported.
+ *	ISC_R_DISABLED		IPv6 is disabled.
  *	ISC_R_UNEXPECTED
  */
 
@@ -272,6 +274,18 @@ isc_net_probe_ipv6only(void);
  *	ISC_R_UNEXPECTED
  */
 
+void
+isc_net_disableipv4(void);
+
+void
+isc_net_disableipv6(void);
+
+void
+isc_net_enableipv4(void);
+
+void
+isc_net_enableipv6(void);
+
 #ifdef ISC_PLATFORM_NEEDNTOP
 const char *
 isc_net_ntop(int af, const void *src, char *dst, size_t size);

lib/isc/unix/net.c

@@ -15,7 +15,7 @@
  * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: net.c,v 1.27 2002/12/24 05:12:50 marka Exp $ */
+/* $Id: net.c,v 1.28 2003/01/16 03:59:27 marka Exp $ */
 
 #include <config.h>
 
@@ -95,7 +95,7 @@ try_proto(int domain) {
 				      "socket from the kernel failed.");
 			isc_log_write(isc_lctx, ISC_LOGCATEGORY_GENERAL,
 				      ISC_LOGMODULE_SOCKET, ISC_LOG_ERROR,
-				      "IPv6 support is disabled.");
+				      "IPv6 is not supported.");
 			result = ISC_R_NOTFOUND;
 		} else {
 			if (len == sizeof(struct sockaddr_in6))
@@ -111,7 +111,7 @@ try_proto(int domain) {
 					      ISC_LOGCATEGORY_GENERAL,
 					      ISC_LOGMODULE_SOCKET,
 					      ISC_LOG_ERROR,
-					      "IPv6 support is disabled.");
+					      "IPv6 is not supported.");
 				result = ISC_R_NOTFOUND;
 			}
 		}
@@ -247,3 +247,31 @@ isc_net_probe_ipv6only(void) {
 #endif
 	return (ipv6only_result);
 }
+
+void
+isc_net_disableipv4(void) {
+	initialize();
+	if (ipv4_result == ISC_R_SUCCESS)
+		ipv4_result = ISC_R_DISABLED;
+}
+
+void
+isc_net_disableipv6(void) {
+	initialize();
+	if (ipv6_result == ISC_R_SUCCESS)
+		ipv6_result = ISC_R_DISABLED;
+}
+
+void
+isc_net_enableipv4(void) {
+	initialize();
+	if (ipv4_result == ISC_R_DISABLED)
+		ipv4_result = ISC_R_SUCCESS;
+}
+
+void
+isc_net_enableipv6(void) {
+	initialize();
+	if (ipv6_result == ISC_R_DISABLED)
+		ipv6_result = ISC_R_SUCCESS;
+}

lib/isc/win32/include/isc/net.h

@@ -15,7 +15,7 @@
  * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: net.h,v 1.18 2002/10/29 04:40:26 marka Exp $ */
+/* $Id: net.h,v 1.19 2003/01/16 03:59:28 marka Exp $ */
 
 #ifndef ISC_NET_H
 #define ISC_NET_H 1
@@ -232,6 +232,7 @@ isc_net_probeipv4(void);
  *
  *	ISC_R_SUCCESS		IPv4 is supported.
  *	ISC_R_NOTFOUND		IPv4 is not supported.
+ *	ISC_R_DISABLED		IPv4 is disabled.
  *	ISC_R_UNEXPECTED
  */
 
@@ -244,6 +245,7 @@ isc_net_probeipv6(void);
  *
  *	ISC_R_SUCCESS		IPv6 is supported.
  *	ISC_R_NOTFOUND		IPv6 is not supported.
+ *	ISC_R_DISABLED		IPv6 is disabled.
  *	ISC_R_UNEXPECTED
  */
 
@@ -259,6 +261,18 @@ isc_net_probe_ipv6only(void);
  *	ISC_R_UNEXPECTED
  */
 
+void
+isc_net_disableipv4(void);
+
+void
+isc_net_disableipv6(void);
+
+void
+isc_net_enableipv4(void);
+
+void
+isc_net_enableipv6(void);
+
 #ifdef ISC_PLATFORM_NEEDNTOP
 const char *
 isc_net_ntop(int af, const void *src, char *dst, size_t size);

lib/isc/win32/net.c

@@ -15,7 +15,7 @@
  * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: net.c,v 1.6 2003/01/14 23:37:06 marka Exp $ */
+/* $Id: net.c,v 1.7 2003/01/16 03:59:27 marka Exp $ */
 
 #include <config.h>
 
@@ -240,3 +240,31 @@ isc_net_probe_ipv6only(void) {
 #endif
 	return (ipv6only_result);
 }
+
+void
+isc_net_disableipv4(void) {
+	initialize();
+	if (ipv4_result == ISC_R_SUCCESS)
+		ipv4_result = ISC_R_DISABLED;
+}
+
+void
+isc_net_disableipv6(void) {
+	initialize();
+	if (ipv6_result == ISC_R_SUCCESS)
+		ipv6_result = ISC_R_DISABLED;
+}
+
+void
+isc_net_enableipv4(void) {
+	initialize();
+	if (ipv4_result == ISC_R_DISABLED)
+		ipv4_result = ISC_R_SUCCESS;
+}
+
+void
+isc_net_enableipv6(void) {
+	initialize();
+	if (ipv6_result == ISC_R_DISABLED)