Adding upstream version 1:9.16.44.upstream/1%9.16.44upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

52 files changed, 5203 insertions, 0 deletions

diff --git a/lib/irs/Kyuafile b/lib/irs/Kyuafile
new file mode 100644
index 0000000..c796010
--- /dev/null
+++ b/lib/irs/Kyuafile
@@ -0,0 +1,15 @@
+-- Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+--
+-- SPDX-License-Identifier: MPL-2.0
+--
+-- 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 https://mozilla.org/MPL/2.0/.
+--
+-- See the COPYRIGHT file distributed with this work for additional
+-- information regarding copyright ownership.
+
+syntax(2)
+test_suite('bind9')
+
+include('tests/Kyuafile')
diff --git a/lib/irs/Makefile.in b/lib/irs/Makefile.in
new file mode 100644
index 0000000..6152e9a
--- /dev/null
+++ b/lib/irs/Makefile.in
@@ -0,0 +1,90 @@
+# Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+#
+# SPDX-License-Identifier: MPL-2.0
+#
+# 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 https://mozilla.org/MPL/2.0/.
+#
+# See the COPYRIGHT file distributed with this work for additional
+# information regarding copyright ownership.
+
+srcdir =	@srcdir@
+VPATH =		@srcdir@
+top_srcdir =	@top_srcdir@
+
+VERSION=@BIND9_VERSION@
+
+@BIND9_MAKE_INCLUDES@
+
+CINCLUDES =	-I. -I./include -I${srcdir}/include \
+		${DNS_INCLUDES} ${ISC_INCLUDES} \
+		${ISCCFG_INCLUDES} \
+		${OPENSSL_CFLAGS}
+
+CDEFINES =
+CWARNINGS =
+
+ISCLIBS =	../../lib/isc/libisc.@A@ @NO_LIBTOOL_ISCLIBS@
+
+ISCDEPLIBS =	../../lib/isc/libisc.@A@
+
+DNSLIBS =	../../lib/dns/libdns.@A@ @NO_LIBTOOL_DNSLIBS@
+
+DNSDEPLIBS =	../../lib/dns/libdns.@A@
+
+ISCCFGLIBS =	../../lib/isccfg/libisccfg.@A@
+
+ISCCFGDEPLIBS =	../../lib/isccfg/libisccfg.@A@
+
+LIBS =		@LIBS@
+
+# Alphabetically
+OBJS =		context.@O@ \
+		dnsconf.@O@ \
+		gai_strerror.@O@ getaddrinfo.@O@ getnameinfo.@O@ \
+		resconf.@O@
+
+# Alphabetically
+SRCS =		context.c \
+		dnsconf.c \
+		gai_strerror.c getaddrinfo.c getnameinfo.c \
+		resconf.c
+
+SUBDIRS =	include
+TESTDIRS =	@UNITTESTS@
+TARGETS =	timestamp
+
+@BIND9_MAKE_RULES@
+
+version.@O@: version.c
+	${LIBTOOL_MODE_COMPILE} ${CC} ${ALL_CFLAGS} \
+		-DVERSION=\"${VERSION}\" \
+		-c ${srcdir}/version.c
+
+libirs.@SA@: ${OBJS} version.@O@
+	${AR} ${ARFLAGS} $@ ${OBJS} version.@O@
+	${RANLIB} $@
+
+libirs.la: ${OBJS} version.@O@
+	${LIBTOOL_MODE_LINK} \
+		${CC} ${ALL_CFLAGS} ${LDFLAGS} -o libirs.la -rpath ${libdir} \
+		-release "${VERSION}" \
+		${OBJS} version.@O@ ${ISCLIBS} ${DNSLIBS} ${ISCCFGLIBS} ${LIBS}
+
+timestamp: libirs.@A@
+	touch timestamp
+
+testdirs: libirs.@A@
+
+installdirs:
+	$(SHELL) ${top_srcdir}/mkinstalldirs ${DESTDIR}${libdir}
+
+install:: timestamp installdirs
+	${LIBTOOL_MODE_INSTALL} ${INSTALL_LIBRARY} libirs.@A@ ${DESTDIR}${libdir}
+
+uninstall::
+	${LIBTOOL_MODE_UNINSTALL} rm -f ${DESTDIR}${libdir}/libirs.@A@
+
+clean distclean::
+	rm -f libirs.@A@ libirs.la timestamp
diff --git a/lib/irs/context.c b/lib/irs/context.c
new file mode 100644
index 0000000..e783358
--- /dev/null
+++ b/lib/irs/context.c
@@ -0,0 +1,334 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ *
+ * 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 https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+#include <stdbool.h>
+
+#include <isc/app.h>
+#include <isc/lib.h>
+#include <isc/magic.h>
+#include <isc/managers.h>
+#include <isc/mem.h>
+#include <isc/netmgr.h>
+#include <isc/once.h>
+#include <isc/socket.h>
+#include <isc/task.h>
+#include <isc/thread.h>
+#include <isc/timer.h>
+#include <isc/util.h>
+
+#include <dns/client.h>
+#include <dns/lib.h>
+
+#include <irs/context.h>
+#include <irs/dnsconf.h>
+#include <irs/resconf.h>
+
+#define IRS_CONTEXT_MAGIC    ISC_MAGIC('I', 'R', 'S', 'c')
+#define IRS_CONTEXT_VALID(c) ISC_MAGIC_VALID(c, IRS_CONTEXT_MAGIC)
+
+#ifndef RESOLV_CONF
+/*% location of resolve.conf */
+#define RESOLV_CONF "/etc/resolv.conf"
+#endif /* ifndef RESOLV_CONF */
+
+#ifndef DNS_CONF
+/*% location of dns.conf */
+#define DNS_CONF "/etc/dns.conf"
+#endif /* ifndef DNS_CONF */
+
+ISC_THREAD_LOCAL irs_context_t *irs_context = NULL;
+
+struct irs_context {
+	/*
+	 * An IRS context is a thread-specific object, and does not need to
+	 * be locked.
+	 */
+	unsigned int magic;
+	isc_mem_t *mctx;
+	isc_appctx_t *actx;
+	isc_nm_t *netmgr;
+	isc_taskmgr_t *taskmgr;
+	isc_task_t *task;
+	isc_socketmgr_t *socketmgr;
+	isc_timermgr_t *timermgr;
+	dns_client_t *dnsclient;
+	irs_resconf_t *resconf;
+	irs_dnsconf_t *dnsconf;
+};
+
+static void
+ctxs_destroy(isc_mem_t **mctxp, isc_appctx_t **actxp, isc_nm_t **netmgrp,
+	     isc_taskmgr_t **taskmgrp, isc_socketmgr_t **socketmgrp,
+	     isc_timermgr_t **timermgrp) {
+	isc_managers_destroy(netmgrp == NULL ? NULL : netmgrp,
+			     taskmgrp == NULL ? NULL : taskmgrp);
+
+	if (timermgrp != NULL) {
+		isc_timermgr_destroy(timermgrp);
+	}
+
+	if (socketmgrp != NULL) {
+		isc_socketmgr_destroy(socketmgrp);
+	}
+
+	if (actxp != NULL) {
+		isc_appctx_destroy(actxp);
+	}
+
+	if (mctxp != NULL) {
+		isc_mem_destroy(mctxp);
+	}
+}
+
+static isc_result_t
+ctxs_init(isc_mem_t **mctxp, isc_appctx_t **actxp, isc_nm_t **netmgrp,
+	  isc_taskmgr_t **taskmgrp, isc_socketmgr_t **socketmgrp,
+	  isc_timermgr_t **timermgrp) {
+	isc_result_t result;
+
+	isc_mem_create(mctxp);
+
+	result = isc_appctx_create(*mctxp, actxp);
+	if (result != ISC_R_SUCCESS) {
+		goto fail;
+	}
+
+	result = isc_managers_create(*mctxp, 1, 0, netmgrp, taskmgrp);
+	if (result != ISC_R_SUCCESS) {
+		goto fail;
+	}
+
+	result = isc_socketmgr_create(*mctxp, socketmgrp);
+	if (result != ISC_R_SUCCESS) {
+		goto fail;
+	}
+
+	result = isc_timermgr_create(*mctxp, timermgrp);
+	if (result != ISC_R_SUCCESS) {
+		goto fail;
+	}
+
+	return (ISC_R_SUCCESS);
+
+fail:
+	ctxs_destroy(mctxp, actxp, netmgrp, taskmgrp, socketmgrp, timermgrp);
+
+	return (result);
+}
+
+isc_result_t
+irs_context_get(irs_context_t **contextp) {
+	isc_result_t result;
+
+	REQUIRE(contextp != NULL && *contextp == NULL);
+
+	if (irs_context == NULL) {
+		result = irs_context_create(&irs_context);
+		if (result != ISC_R_SUCCESS) {
+			return (result);
+		}
+	}
+
+	*contextp = irs_context;
+
+	return (ISC_R_SUCCESS);
+}
+
+isc_result_t
+irs_context_create(irs_context_t **contextp) {
+	isc_result_t result;
+	irs_context_t *context;
+	isc_appctx_t *actx = NULL;
+	isc_mem_t *mctx = NULL;
+	isc_nm_t *netmgr = NULL;
+	isc_taskmgr_t *taskmgr = NULL;
+	isc_socketmgr_t *socketmgr = NULL;
+	isc_timermgr_t *timermgr = NULL;
+	dns_client_t *client = NULL;
+	isc_sockaddrlist_t *nameservers;
+	irs_dnsconf_dnskeylist_t *trustedkeys;
+	irs_dnsconf_dnskey_t *trustedkey;
+
+	isc_lib_register();
+	result = dns_lib_init();
+	if (result != ISC_R_SUCCESS) {
+		return (result);
+	}
+
+	result = ctxs_init(&mctx, &actx, &netmgr, &taskmgr, &socketmgr,
+			   &timermgr);
+	if (result != ISC_R_SUCCESS) {
+		return (result);
+	}
+
+	result = isc_app_ctxstart(actx);
+	if (result != ISC_R_SUCCESS) {
+		ctxs_destroy(&mctx, &actx, &netmgr, &taskmgr, &socketmgr,
+			     &timermgr);
+		return (result);
+	}
+
+	context = isc_mem_get(mctx, sizeof(*context));
+
+	context->mctx = mctx;
+	context->actx = actx;
+	context->taskmgr = taskmgr;
+	context->socketmgr = socketmgr;
+	context->timermgr = timermgr;
+	context->resconf = NULL;
+	context->dnsconf = NULL;
+	context->task = NULL;
+	result = isc_task_create(taskmgr, 0, &context->task);
+	if (result != ISC_R_SUCCESS) {
+		goto fail;
+	}
+
+	/* Create a DNS client object */
+	result = dns_client_create(mctx, actx, taskmgr, socketmgr, timermgr, 0,
+				   &client, NULL, NULL);
+	if (result != ISC_R_SUCCESS) {
+		goto fail;
+	}
+	context->dnsclient = client;
+
+	/* Read resolver configuration file */
+	result = irs_resconf_load(mctx, RESOLV_CONF, &context->resconf);
+	if (result != ISC_R_SUCCESS) {
+		goto fail;
+	}
+	/* Set nameservers */
+	nameservers = irs_resconf_getnameservers(context->resconf);
+	result = dns_client_setservers(client, dns_rdataclass_in, NULL,
+				       nameservers);
+	if (result != ISC_R_SUCCESS) {
+		goto fail;
+	}
+
+	/* Read advanced DNS configuration (if any) */
+	result = irs_dnsconf_load(mctx, DNS_CONF, &context->dnsconf);
+	if (result != ISC_R_SUCCESS) {
+		goto fail;
+	}
+	trustedkeys = irs_dnsconf_gettrustedkeys(context->dnsconf);
+	for (trustedkey = ISC_LIST_HEAD(*trustedkeys); trustedkey != NULL;
+	     trustedkey = ISC_LIST_NEXT(trustedkey, link))
+	{
+		result = dns_client_addtrustedkey(
+			client, dns_rdataclass_in, dns_rdatatype_dnskey,
+			trustedkey->keyname, trustedkey->keydatabuf);
+		if (result != ISC_R_SUCCESS) {
+			goto fail;
+		}
+	}
+
+	context->magic = IRS_CONTEXT_MAGIC;
+	*contextp = context;
+
+	return (ISC_R_SUCCESS);
+
+fail:
+	if (context->task != NULL) {
+		isc_task_detach(&context->task);
+	}
+	if (context->resconf != NULL) {
+		irs_resconf_destroy(&context->resconf);
+	}
+	if (context->dnsconf != NULL) {
+		irs_dnsconf_destroy(&context->dnsconf);
+	}
+	if (client != NULL) {
+		dns_client_destroy(&client);
+	}
+	ctxs_destroy(NULL, &actx, &netmgr, &taskmgr, &socketmgr, &timermgr);
+	isc_mem_putanddetach(&mctx, context, sizeof(*context));
+
+	return (result);
+}
+
+void
+irs_context_destroy(irs_context_t **contextp) {
+	irs_context_t *context;
+
+	REQUIRE(contextp != NULL);
+	context = *contextp;
+	REQUIRE(IRS_CONTEXT_VALID(context));
+	*contextp = irs_context = NULL;
+
+	isc_task_detach(&context->task);
+	irs_dnsconf_destroy(&context->dnsconf);
+	irs_resconf_destroy(&context->resconf);
+	dns_client_destroy(&context->dnsclient);
+
+	ctxs_destroy(NULL, &context->actx, &context->netmgr, &context->taskmgr,
+		     &context->socketmgr, &context->timermgr);
+
+	context->magic = 0;
+
+	isc_mem_putanddetach(&context->mctx, context, sizeof(*context));
+}
+
+isc_mem_t *
+irs_context_getmctx(irs_context_t *context) {
+	REQUIRE(IRS_CONTEXT_VALID(context));
+
+	return (context->mctx);
+}
+
+isc_appctx_t *
+irs_context_getappctx(irs_context_t *context) {
+	REQUIRE(IRS_CONTEXT_VALID(context));
+
+	return (context->actx);
+}
+
+isc_taskmgr_t *
+irs_context_gettaskmgr(irs_context_t *context) {
+	REQUIRE(IRS_CONTEXT_VALID(context));
+
+	return (context->taskmgr);
+}
+
+isc_timermgr_t *
+irs_context_gettimermgr(irs_context_t *context) {
+	REQUIRE(IRS_CONTEXT_VALID(context));
+
+	return (context->timermgr);
+}
+
+isc_task_t *
+irs_context_gettask(irs_context_t *context) {
+	REQUIRE(IRS_CONTEXT_VALID(context));
+
+	return (context->task);
+}
+
+dns_client_t *
+irs_context_getdnsclient(irs_context_t *context) {
+	REQUIRE(IRS_CONTEXT_VALID(context));
+
+	return (context->dnsclient);
+}
+
+irs_resconf_t *
+irs_context_getresconf(irs_context_t *context) {
+	REQUIRE(IRS_CONTEXT_VALID(context));
+
+	return (context->resconf);
+}
+
+irs_dnsconf_t *
+irs_context_getdnsconf(irs_context_t *context) {
+	REQUIRE(IRS_CONTEXT_VALID(context));
+
+	return (context->dnsconf);
+}
diff --git a/lib/irs/dnsconf.c b/lib/irs/dnsconf.c
new file mode 100644
index 0000000..a1421d2
--- /dev/null
+++ b/lib/irs/dnsconf.c
@@ -0,0 +1,291 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ *
+ * 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 https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+/*! \file */
+
+#include <inttypes.h>
+#include <string.h>
+
+#include <isc/base64.h>
+#include <isc/buffer.h>
+#include <isc/file.h>
+#include <isc/mem.h>
+#include <isc/util.h>
+
+#include <dns/fixedname.h>
+#include <dns/name.h>
+#include <dns/rdata.h>
+#include <dns/rdatastruct.h>
+
+#include <isccfg/dnsconf.h>
+
+#include <irs/dnsconf.h>
+
+#define IRS_DNSCONF_MAGIC    ISC_MAGIC('D', 'c', 'f', 'g')
+#define IRS_DNSCONF_VALID(c) ISC_MAGIC_VALID(c, IRS_DNSCONF_MAGIC)
+
+/*!
+ * configuration data structure
+ */
+
+struct irs_dnsconf {
+	unsigned int magic;
+	isc_mem_t *mctx;
+	irs_dnsconf_dnskeylist_t trusted_keylist;
+};
+
+static isc_result_t
+configure_key(isc_mem_t *mctx, const cfg_obj_t *key, irs_dnsconf_t *conf,
+	      dns_rdataclass_t rdclass) {
+	isc_result_t result;
+	uint32_t flags, proto, alg;
+	dns_fixedname_t fkeyname;
+	dns_name_t *keyname_base = NULL, *keyname = NULL;
+	const char *keystr = NULL, *keynamestr = NULL;
+	unsigned char keydata[4096];
+	isc_buffer_t keydatabuf_base, *keydatabuf = NULL;
+	dns_rdata_dnskey_t keystruct;
+	unsigned char rrdata[4096];
+	isc_buffer_t rrdatabuf;
+	isc_region_t r;
+	isc_buffer_t namebuf;
+	irs_dnsconf_dnskey_t *keyent = NULL;
+
+	flags = cfg_obj_asuint32(cfg_tuple_get(key, "flags"));
+	proto = cfg_obj_asuint32(cfg_tuple_get(key, "protocol"));
+	alg = cfg_obj_asuint32(cfg_tuple_get(key, "algorithm"));
+	keynamestr = cfg_obj_asstring(cfg_tuple_get(key, "name"));
+
+	keystruct.common.rdclass = rdclass;
+	keystruct.common.rdtype = dns_rdatatype_dnskey;
+	keystruct.mctx = NULL;
+	ISC_LINK_INIT(&keystruct.common, link);
+
+	if (flags > 0xffff) {
+		return (ISC_R_RANGE);
+	}
+	if (proto > 0xff) {
+		return (ISC_R_RANGE);
+	}
+	if (alg > 0xff) {
+		return (ISC_R_RANGE);
+	}
+	keystruct.flags = (uint16_t)flags;
+	keystruct.protocol = (uint8_t)proto;
+	keystruct.algorithm = (uint8_t)alg;
+
+	isc_buffer_init(&keydatabuf_base, keydata, sizeof(keydata));
+	isc_buffer_init(&rrdatabuf, rrdata, sizeof(rrdata));
+
+	/* Configure key value */
+	keystr = cfg_obj_asstring(cfg_tuple_get(key, "key"));
+	result = isc_base64_decodestring(keystr, &keydatabuf_base);
+	if (result != ISC_R_SUCCESS) {
+		return (result);
+	}
+	isc_buffer_usedregion(&keydatabuf_base, &r);
+	keystruct.datalen = r.length;
+	keystruct.data = r.base;
+
+	result = dns_rdata_fromstruct(NULL, keystruct.common.rdclass,
+				      keystruct.common.rdtype, &keystruct,
+				      &rrdatabuf);
+	if (result != ISC_R_SUCCESS) {
+		return (result);
+	}
+	isc_buffer_usedregion(&rrdatabuf, &r);
+	isc_buffer_allocate(mctx, &keydatabuf, r.length);
+	result = isc_buffer_copyregion(keydatabuf, &r);
+	if (result != ISC_R_SUCCESS) {
+		goto cleanup;
+	}
+
+	/* Configure key name */
+	keyname_base = dns_fixedname_initname(&fkeyname);
+	isc_buffer_constinit(&namebuf, keynamestr, strlen(keynamestr));
+	isc_buffer_add(&namebuf, strlen(keynamestr));
+	result = dns_name_fromtext(keyname_base, &namebuf, dns_rootname, 0,
+				   NULL);
+	if (result != ISC_R_SUCCESS) {
+		return (result);
+	}
+	keyname = isc_mem_get(mctx, sizeof(*keyname));
+	dns_name_init(keyname, NULL);
+	dns_name_dup(keyname_base, mctx, keyname);
+
+	/* Add the key data to the list */
+	keyent = isc_mem_get(mctx, sizeof(*keyent));
+	keyent->keyname = keyname;
+	keyent->keydatabuf = keydatabuf;
+
+	ISC_LIST_APPEND(conf->trusted_keylist, keyent, link);
+
+cleanup:
+	if (keydatabuf != NULL) {
+		isc_buffer_free(&keydatabuf);
+	}
+	if (keyname != NULL) {
+		isc_mem_put(mctx, keyname, sizeof(*keyname));
+	}
+
+	return (result);
+}
+
+static isc_result_t
+configure_keygroup(irs_dnsconf_t *conf, const cfg_obj_t *keys,
+		   dns_rdataclass_t rdclass) {
+	isc_result_t result;
+	const cfg_obj_t *key, *keylist;
+	const cfg_listelt_t *element, *element2;
+	isc_mem_t *mctx = conf->mctx;
+
+	for (element = cfg_list_first(keys); element != NULL;
+	     element = cfg_list_next(element))
+	{
+		keylist = cfg_listelt_value(element);
+		for (element2 = cfg_list_first(keylist); element2 != NULL;
+		     element2 = cfg_list_next(element2))
+		{
+			key = cfg_listelt_value(element2);
+			result = configure_key(mctx, key, conf, rdclass);
+			if (result != ISC_R_SUCCESS) {
+				return (result);
+			}
+		}
+	}
+
+	return (ISC_R_SUCCESS);
+}
+
+static isc_result_t
+configure_dnsseckeys(irs_dnsconf_t *conf, cfg_obj_t *cfgobj,
+		     dns_rdataclass_t rdclass) {
+	isc_result_t result;
+	const cfg_obj_t *keys = NULL;
+
+	cfg_map_get(cfgobj, "trusted-keys", &keys);
+	if (keys == NULL) {
+		return (ISC_R_SUCCESS);
+	}
+
+	result = configure_keygroup(conf, keys, rdclass);
+	if (result != ISC_R_SUCCESS) {
+		return (result);
+	}
+
+	keys = NULL;
+	cfg_map_get(cfgobj, "trust-anchors", &keys);
+	if (keys == NULL) {
+		return (ISC_R_SUCCESS);
+	}
+
+	result = configure_keygroup(conf, keys, rdclass);
+	if (result != ISC_R_SUCCESS) {
+		return (result);
+	}
+
+	keys = NULL;
+	cfg_map_get(cfgobj, "managed-keys", &keys);
+	if (keys == NULL) {
+		return (ISC_R_SUCCESS);
+	}
+
+	result = configure_keygroup(conf, keys, rdclass);
+	if (result != ISC_R_SUCCESS) {
+		return (result);
+	}
+
+	return (ISC_R_SUCCESS);
+}
+
+isc_result_t
+irs_dnsconf_load(isc_mem_t *mctx, const char *filename, irs_dnsconf_t **confp) {
+	irs_dnsconf_t *conf;
+	cfg_parser_t *parser = NULL;
+	cfg_obj_t *cfgobj = NULL;
+	isc_result_t result = ISC_R_SUCCESS;
+
+	REQUIRE(confp != NULL && *confp == NULL);
+
+	conf = isc_mem_get(mctx, sizeof(*conf));
+
+	conf->mctx = mctx;
+	ISC_LIST_INIT(conf->trusted_keylist);
+
+	/*
+	 * If the specified file does not exist, we'll simply with an empty
+	 * configuration.
+	 */
+	if (!isc_file_exists(filename)) {
+		goto cleanup;
+	}
+
+	result = cfg_parser_create(mctx, NULL, &parser);
+	if (result != ISC_R_SUCCESS) {
+		goto cleanup;
+	}
+
+	result = cfg_parse_file(parser, filename, &cfg_type_dnsconf, &cfgobj);
+	if (result != ISC_R_SUCCESS) {
+		goto cleanup;
+	}
+
+	result = configure_dnsseckeys(conf, cfgobj, dns_rdataclass_in);
+
+cleanup:
+	if (parser != NULL) {
+		if (cfgobj != NULL) {
+			cfg_obj_destroy(parser, &cfgobj);
+		}
+		cfg_parser_destroy(&parser);
+	}
+
+	conf->magic = IRS_DNSCONF_MAGIC;
+
+	if (result == ISC_R_SUCCESS) {
+		*confp = conf;
+	} else {
+		irs_dnsconf_destroy(&conf);
+	}
+
+	return (result);
+}
+
+void
+irs_dnsconf_destroy(irs_dnsconf_t **confp) {
+	irs_dnsconf_t *conf;
+	irs_dnsconf_dnskey_t *keyent;
+
+	REQUIRE(confp != NULL);
+	conf = *confp;
+	*confp = NULL;
+	REQUIRE(IRS_DNSCONF_VALID(conf));
+
+	while ((keyent = ISC_LIST_HEAD(conf->trusted_keylist)) != NULL) {
+		ISC_LIST_UNLINK(conf->trusted_keylist, keyent, link);
+
+		isc_buffer_free(&keyent->keydatabuf);
+		dns_name_free(keyent->keyname, conf->mctx);
+		isc_mem_put(conf->mctx, keyent->keyname, sizeof(dns_name_t));
+		isc_mem_put(conf->mctx, keyent, sizeof(*keyent));
+	}
+
+	isc_mem_put(conf->mctx, conf, sizeof(*conf));
+}
+
+irs_dnsconf_dnskeylist_t *
+irs_dnsconf_gettrustedkeys(irs_dnsconf_t *conf) {
+	REQUIRE(IRS_DNSCONF_VALID(conf));
+
+	return (&conf->trusted_keylist);
+}
diff --git a/lib/irs/gai_strerror.c b/lib/irs/gai_strerror.c
new file mode 100644
index 0000000..a2b989f
--- /dev/null
+++ b/lib/irs/gai_strerror.c
@@ -0,0 +1,96 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ *
+ * 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 https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+/*! \file gai_strerror.c
+ * gai_strerror() returns an error message corresponding to an
+ * error code returned by getaddrinfo() and getnameinfo(). The following error
+ * codes and their meaning are defined in
+ * \link netdb.h include/irs/netdb.h.\endlink
+ * This implementation is almost an exact copy of lwres/gai_sterror.c except
+ * that it catches up the latest API standard, RFC3493.
+ *
+ * \li #EAI_ADDRFAMILY address family for hostname not supported
+ * \li #EAI_AGAIN temporary failure in name resolution
+ * \li #EAI_BADFLAGS invalid value for ai_flags
+ * \li #EAI_FAIL non-recoverable failure in name resolution
+ * \li #EAI_FAMILY ai_family not supported
+ * \li #EAI_MEMORY memory allocation failure
+ * \li #EAI_NODATA no address associated with hostname (obsoleted in RFC3493)
+ * \li #EAI_NONAME hostname nor servname provided, or not known
+ * \li #EAI_SERVICE servname not supported for ai_socktype
+ * \li #EAI_SOCKTYPE ai_socktype not supported
+ * \li #EAI_SYSTEM system error returned in errno
+ * \li #EAI_BADHINTS Invalid value for hints (non-standard)
+ * \li #EAI_PROTOCOL Resolved protocol is unknown (non-standard)
+ * \li #EAI_OVERFLOW Argument buffer overflow
+ * \li #EAI_INSECUREDATA Insecure Data (experimental)
+ *
+ * The message invalid error code is returned if ecode is out of range.
+ *
+ * ai_flags, ai_family and ai_socktype are elements of the struct
+ * addrinfo used by lwres_getaddrinfo().
+ *
+ * \section gai_strerror_see See Also
+ *
+ * strerror(), getaddrinfo(), getnameinfo(), RFC3493.
+ */
+
+#include <isc/net.h>
+
+#include <irs/netdb.h>
+
+/*% Text of error messages. */
+static const char *gai_messages[] = { "no error",
+				      "address family for hostname not "
+				      "supported",
+				      "temporary failure in name resolution",
+				      "invalid value for ai_flags",
+				      "non-recoverable failure in name "
+				      "resolution",
+				      "ai_family not supported",
+				      "memory allocation failure",
+				      "no address associated with hostname",
+				      "hostname nor servname provided, or not "
+				      "known",
+				      "servname not supported for ai_socktype",
+				      "ai_socktype not supported",
+				      "system error returned in errno",
+				      "bad hints",
+				      "bad protocol",
+				      "argument buffer overflow",
+				      "insecure data provided" };
+
+/*%
+ * Returns an error message corresponding to an error code returned by
+ * getaddrinfo() and getnameinfo()
+ */
+#if defined _WIN32
+char *
+#else  /* if defined _WIN32 */
+const char *
+#endif /* if defined _WIN32 */
+gai_strerror(int ecode) {
+	union {
+		const char *const_ptr;
+		char *deconst_ptr;
+	} ptr;
+
+	if ((ecode < 0) ||
+	    (ecode >= (int)(sizeof(gai_messages) / sizeof(*gai_messages))))
+	{
+		ptr.const_ptr = "invalid error code";
+	} else {
+		ptr.const_ptr = gai_messages[ecode];
+	}
+	return (ptr.deconst_ptr);
+}
diff --git a/lib/irs/getaddrinfo.c b/lib/irs/getaddrinfo.c
new file mode 100644
index 0000000..f450a55
--- /dev/null
+++ b/lib/irs/getaddrinfo.c
@@ -0,0 +1,1365 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ *
+ * 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 https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+/*! \file */
+
+/**
+ *    getaddrinfo() is used to get a list of IP addresses and port
+ *    numbers for host hostname and service servname as defined in RFC3493.
+ *    hostname and servname are pointers to null-terminated strings
+ *    or NULL. hostname is either a host name or a numeric host address
+ *    string: a dotted decimal IPv4 address or an IPv6 address. servname is
+ *    either a decimal port number or a service name as listed in
+ *    /etc/services.
+ *
+ *    If the operating system does not provide a struct addrinfo, the
+ *    following structure is used:
+ *
+ * \code
+ * struct  addrinfo {
+ *         int             ai_flags;       // AI_PASSIVE, AI_CANONNAME
+ *         int             ai_family;      // PF_xxx
+ *         int             ai_socktype;    // SOCK_xxx
+ *         int             ai_protocol;    // 0 or IPPROTO_xxx for IPv4 and IPv6
+ *         size_t          ai_addrlen;     // length of ai_addr
+ *         char            *ai_canonname;  // canonical name for hostname
+ *         struct sockaddr *ai_addr;       // binary address
+ *         struct addrinfo *ai_next;       // next structure in linked list
+ * };
+ * \endcode
+ *
+ *
+ *    hints is an optional pointer to a struct addrinfo. This structure can
+ *    be used to provide hints concerning the type of socket that the caller
+ *    supports or wishes to use. The caller can supply the following
+ *    structure elements in *hints:
+ *
+ * <ul>
+ *    <li>ai_family:
+ *           The protocol family that should be used. When ai_family is set
+ *           to PF_UNSPEC, it means the caller will accept any protocol
+ *           family supported by the operating system.</li>
+ *
+ *    <li>ai_socktype:
+ *           denotes the type of socket -- SOCK_STREAM, SOCK_DGRAM or
+ *           SOCK_RAW -- that is wanted. When ai_socktype is zero the caller
+ *           will accept any socket type.</li>
+ *
+ *    <li>ai_protocol:
+ *           indicates which transport protocol is wanted: IPPROTO_UDP or
+ *           IPPROTO_TCP. If ai_protocol is zero the caller will accept any
+ *           protocol.</li>
+ *
+ *    <li>ai_flags:
+ *           Flag bits. If the AI_CANONNAME bit is set, a successful call to
+ *           getaddrinfo() will return a null-terminated string
+ *           containing the canonical name of the specified hostname in
+ *           ai_canonname of the first addrinfo structure returned. Setting
+ *           the AI_PASSIVE bit indicates that the returned socket address
+ *           structure is intended for used in a call to bind(2). In this
+ *           case, if the hostname argument is a NULL pointer, then the IP
+ *           address portion of the socket address structure will be set to
+ *           INADDR_ANY for an IPv4 address or IN6ADDR_ANY_INIT for an IPv6
+ *           address.<br /><br />
+ *
+ *           When ai_flags does not set the AI_PASSIVE bit, the returned
+ *           socket address structure will be ready for use in a call to
+ *           connect(2) for a connection-oriented protocol or connect(2),
+ *           sendto(2), or sendmsg(2) if a connectionless protocol was
+ *           chosen. The IP address portion of the socket address structure
+ *           will be set to the loopback address if hostname is a NULL
+ *           pointer and AI_PASSIVE is not set in ai_flags.<br /><br />
+ *
+ *           If ai_flags is set to AI_NUMERICHOST it indicates that hostname
+ *           should be treated as a numeric string defining an IPv4 or IPv6
+ *           address and no name resolution should be attempted.
+ * </li></ul>
+ *
+ *    All other elements of the struct addrinfo passed via hints must be
+ *    zero.
+ *
+ *    A hints of NULL is treated as if the caller provided a struct addrinfo
+ *    initialized to zero with ai_familyset to PF_UNSPEC.
+ *
+ *    After a successful call to getaddrinfo(), *res is a pointer to a
+ *    linked list of one or more addrinfo structures. Each struct addrinfo
+ *    in this list cn be processed by following the ai_next pointer, until a
+ *    NULL pointer is encountered. The three members ai_family, ai_socktype,
+ *    and ai_protocol in each returned addrinfo structure contain the
+ *    corresponding arguments for a call to socket(2). For each addrinfo
+ *    structure in the list, the ai_addr member points to a filled-in socket
+ *    address structure of length ai_addrlen.
+ *
+ *    All of the information returned by getaddrinfo() is dynamically
+ *    allocated: the addrinfo structures, and the socket address structures
+ *    and canonical host name strings pointed to by the addrinfostructures.
+ *    Memory allocated for the dynamically allocated structures created by a
+ *    successful call to getaddrinfo() is released by freeaddrinfo().
+ *    ai is a pointer to a struct addrinfo created by a call to getaddrinfo().
+ *
+ * \section irsreturn RETURN VALUES
+ *
+ *    getaddrinfo() returns zero on success or one of the error codes
+ *    listed in gai_strerror() if an error occurs. If both hostname and
+ *    servname are NULL getaddrinfo() returns #EAI_NONAME.
+ *
+ * \section irssee SEE ALSO
+ *
+ *    getaddrinfo(), freeaddrinfo(),
+ *    gai_strerror(), RFC3493, getservbyname(3), connect(2),
+ *    sendto(2), sendmsg(2), socket(2).
+ */
+
+#include <errno.h>
+#include <inttypes.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+
+#ifdef _WIN32
+#include <windows.h>
+#include <winsock2.h>
+#include <ws2tcpip.h>
+#endif /* ifdef _WIN32 */
+
+#include <isc/app.h>
+#include <isc/buffer.h>
+#include <isc/lib.h>
+#include <isc/mem.h>
+#include <isc/mutex.h>
+#include <isc/print.h>
+#include <isc/sockaddr.h>
+#include <isc/string.h>
+#include <isc/util.h>
+
+#include <dns/client.h>
+#include <dns/fixedname.h>
+#include <dns/name.h>
+#include <dns/rdata.h>
+#include <dns/rdataset.h>
+#include <dns/rdatastruct.h>
+#include <dns/rdatatype.h>
+#include <dns/result.h>
+
+#include <irs/context.h>
+#include <irs/netdb.h>
+#include <irs/resconf.h>
+
+#define SA(addr)     ((struct sockaddr *)(addr))
+#define SIN(addr)    ((struct sockaddr_in *)(addr))
+#define SIN6(addr)   ((struct sockaddr_in6 *)(addr))
+#define SLOCAL(addr) ((struct sockaddr_un *)(addr))
+
+/*! \struct addrinfo
+ */
+static struct addrinfo *
+ai_concat(struct addrinfo *ai1, struct addrinfo *ai2),
+	*ai_reverse(struct addrinfo *oai),
+	*ai_clone(struct addrinfo *oai, int family),
+	*ai_alloc(int family, int addrlen);
+#ifdef AF_LOCAL
+static int
+get_local(const char *name, int socktype, struct addrinfo **res);
+#endif /* ifdef AF_LOCAL */
+
+static int
+resolve_name(int family, const char *hostname, int flags, struct addrinfo **aip,
+	     int socktype, int port);
+
+static int
+add_ipv4(const char *hostname, int flags, struct addrinfo **aip, int socktype,
+	 int port);
+static int
+add_ipv6(const char *hostname, int flags, struct addrinfo **aip, int socktype,
+	 int port);
+static void
+set_order(int, int (**)(const char *, int, struct addrinfo **, int, int));
+static void
+_freeaddrinfo(struct addrinfo *ai);
+
+#define FOUND_IPV4 0x1
+#define FOUND_IPV6 0x2
+#define FOUND_MAX  2
+
+/*%
+ * Try converting the scope identifier in 'src' to a network interface index.
+ * Upon success, return true and store the resulting index in 'dst'.  Upon
+ * failure, return false.
+ */
+static bool
+parse_scopeid(const char *src, uint32_t *dst) {
+	uint32_t scopeid = 0;
+
+	REQUIRE(src != NULL);
+	REQUIRE(dst != NULL);
+
+#ifdef HAVE_IF_NAMETOINDEX
+	/*
+	 * Try using if_nametoindex() first if it is available.  As it does not
+	 * handle numeric scopes, we do not simply return if it fails.
+	 */
+	scopeid = (uint32_t)if_nametoindex(src);
+#endif /* ifdef HAVE_IF_NAMETOINDEX */
+
+	/*
+	 * Fall back to numeric scope processing if if_nametoindex() either
+	 * fails or is unavailable.
+	 */
+	if (scopeid == 0) {
+		char *endptr = NULL;
+		scopeid = (uint32_t)strtoul(src, &endptr, 10);
+		/*
+		 * The scope identifier must not be empty and no trailing
+		 * characters are allowed after it.
+		 */
+		if (src == endptr || endptr == NULL || *endptr != '\0') {
+			return (false);
+		}
+	}
+
+	*dst = scopeid;
+
+	return (true);
+}
+
+#define ISC_AI_MASK (AI_PASSIVE | AI_CANONNAME | AI_NUMERICHOST)
+/*%
+ * Get a list of IP addresses and port numbers for host hostname and
+ * service servname.
+ */
+int
+getaddrinfo(const char *hostname, const char *servname,
+	    const struct addrinfo *hints, struct addrinfo **res) {
+	struct servent *sp;
+	const char *proto;
+	int family, socktype, flags, protocol;
+	struct addrinfo *ai, *ai_list;
+	int err = 0;
+	int port, i;
+	int (*net_order[FOUND_MAX + 1])(const char *, int, struct addrinfo **,
+					int, int);
+
+	if (hostname == NULL && servname == NULL) {
+		return (EAI_NONAME);
+	}
+
+	proto = NULL;
+	if (hints != NULL) {
+		if ((hints->ai_flags & ~(ISC_AI_MASK)) != 0) {
+			return (EAI_BADFLAGS);
+		}
+		if (hints->ai_addrlen || hints->ai_canonname ||
+		    hints->ai_addr || hints->ai_next)
+		{
+			errno = EINVAL;
+			return (EAI_SYSTEM);
+		}
+		family = hints->ai_family;
+		socktype = hints->ai_socktype;
+		protocol = hints->ai_protocol;
+		flags = hints->ai_flags;
+		switch (family) {
+		case AF_UNSPEC:
+			switch (hints->ai_socktype) {
+			case SOCK_STREAM:
+				proto = "tcp";
+				break;
+			case SOCK_DGRAM:
+				proto = "udp";
+				break;
+			}
+			break;
+		case AF_INET:
+		case AF_INET6:
+			switch (hints->ai_socktype) {
+			case 0:
+				break;
+			case SOCK_STREAM:
+				proto = "tcp";
+				break;
+			case SOCK_DGRAM:
+				proto = "udp";
+				break;
+			case SOCK_RAW:
+				break;
+			default:
+				return (EAI_SOCKTYPE);
+			}
+			break;
+#ifdef AF_LOCAL
+		case AF_LOCAL:
+			switch (hints->ai_socktype) {
+			case 0:
+				break;
+			case SOCK_STREAM:
+				break;
+			case SOCK_DGRAM:
+				break;
+			default:
+				return (EAI_SOCKTYPE);
+			}
+			break;
+#endif /* ifdef AF_LOCAL */
+		default:
+			return (EAI_FAMILY);
+		}
+	} else {
+		protocol = 0;
+		family = 0;
+		socktype = 0;
+		flags = 0;
+	}
+
+#ifdef AF_LOCAL
+	/*!
+	 * First, deal with AF_LOCAL.  If the family was not set,
+	 * then assume AF_LOCAL if the first character of the
+	 * hostname/servname is '/'.
+	 */
+
+	if (hostname != NULL &&
+	    (family == AF_LOCAL || (family == 0 && *hostname == '/')))
+	{
+		return (get_local(hostname, socktype, res));
+	}
+
+	if (servname != NULL &&
+	    (family == AF_LOCAL || (family == 0 && *servname == '/')))
+	{
+		return (get_local(servname, socktype, res));
+	}
+#endif /* ifdef AF_LOCAL */
+
+	/*
+	 * Ok, only AF_INET and AF_INET6 left.
+	 */
+	ai_list = NULL;
+
+	/*
+	 * First, look up the service name (port) if it was
+	 * requested.  If the socket type wasn't specified, then
+	 * try and figure it out.
+	 */
+	if (servname != NULL) {
+		char *e;
+
+		port = strtol(servname, &e, 10);
+		if (*e == '\0') {
+			if (socktype == 0) {
+				return (EAI_SOCKTYPE);
+			}
+			if (port < 0 || port > 65535) {
+				return (EAI_SERVICE);
+			}
+			port = htons((unsigned short)port);
+		} else {
+#ifdef _WIN32
+			WORD wVersionRequested;
+			WSADATA wsaData;
+
+			wVersionRequested = MAKEWORD(2, 0);
+
+			err = WSAStartup(wVersionRequested, &wsaData);
+			if (err != 0) {
+				return (EAI_FAIL);
+			}
+#endif /* ifdef _WIN32 */
+			sp = getservbyname(servname, proto);
+			if (sp != NULL) {
+				port = sp->s_port;
+			}
+#ifdef _WIN32
+			WSACleanup();
+#endif /* ifdef _WIN32 */
+			if (sp == NULL) {
+				return (EAI_SERVICE);
+			}
+			if (socktype == 0) {
+				if (strcmp(sp->s_proto, "tcp") == 0) {
+					socktype = SOCK_STREAM;
+				} else if (strcmp(sp->s_proto, "udp") == 0) {
+					socktype = SOCK_DGRAM;
+				}
+			}
+		}
+	} else {
+		port = 0;
+	}
+
+	/*
+	 * Next, deal with just a service name, and no hostname.
+	 * (we verified that one of them was non-null up above).
+	 */
+	if (hostname == NULL && (flags & AI_PASSIVE) != 0) {
+		if (family == AF_INET || family == 0) {
+			ai = ai_alloc(AF_INET, sizeof(struct sockaddr_in));
+			if (ai == NULL) {
+				return (EAI_MEMORY);
+			}
+			ai->ai_socktype = socktype;
+			ai->ai_protocol = protocol;
+			SIN(ai->ai_addr)->sin_port = port;
+			ai->ai_next = ai_list;
+			ai_list = ai;
+		}
+
+		if (family == AF_INET6 || family == 0) {
+			ai = ai_alloc(AF_INET6, sizeof(struct sockaddr_in6));
+			if (ai == NULL) {
+				_freeaddrinfo(ai_list);
+				return (EAI_MEMORY);
+			}
+			ai->ai_socktype = socktype;
+			ai->ai_protocol = protocol;
+			SIN6(ai->ai_addr)->sin6_port = port;
+			ai->ai_next = ai_list;
+			ai_list = ai;
+		}
+
+		*res = ai_list;
+		return (0);
+	}
+
+	/*
+	 * If the family isn't specified or AI_NUMERICHOST specified, check
+	 * first to see if it is a numeric address.
+	 * Though the gethostbyname2() routine will recognize numeric addresses,
+	 * it will only recognize the format that it is being called for.  Thus,
+	 * a numeric AF_INET address will be treated by the AF_INET6 call as
+	 * a domain name, and vice versa.  Checking for both numerics here
+	 * avoids that.
+	 */
+	if (hostname != NULL && (family == 0 || (flags & AI_NUMERICHOST) != 0))
+	{
+		char abuf[sizeof(struct in6_addr)];
+		char nbuf[NI_MAXHOST];
+		int addrsize, addroff;
+		char ntmp[NI_MAXHOST];
+		uint32_t scopeid = 0;
+
+		/*
+		 * Scope identifier portion.
+		 */
+		ntmp[0] = '\0';
+		if (strchr(hostname, '%') != NULL) {
+			char *p;
+			strlcpy(ntmp, hostname, sizeof(ntmp));
+			p = strchr(ntmp, '%');
+
+			if (p != NULL && parse_scopeid(p + 1, &scopeid)) {
+				*p = '\0';
+			} else {
+				ntmp[0] = '\0';
+			}
+		}
+
+		if (inet_pton(AF_INET, hostname, (struct in_addr *)abuf) == 1) {
+			if (family == AF_INET6) {
+				/*
+				 * Convert to a V4 mapped address.
+				 */
+				struct in6_addr *a6 = (struct in6_addr *)abuf;
+				memmove(&a6->s6_addr[12], &a6->s6_addr[0], 4);
+				memset(&a6->s6_addr[10], 0xff, 2);
+				memset(&a6->s6_addr[0], 0, 10);
+				goto inet6_addr;
+			}
+			addrsize = sizeof(struct in_addr);
+			addroff = offsetof(struct sockaddr_in, sin_addr);
+			family = AF_INET;
+			goto common;
+		} else if (ntmp[0] != '\0' &&
+			   inet_pton(AF_INET6, ntmp, abuf) == 1)
+		{
+			if (family && family != AF_INET6) {
+				return (EAI_NONAME);
+			}
+			addrsize = sizeof(struct in6_addr);
+			addroff = offsetof(struct sockaddr_in6, sin6_addr);
+			family = AF_INET6;
+			goto common;
+		} else if (inet_pton(AF_INET6, hostname, abuf) == 1) {
+			if (family != 0 && family != AF_INET6) {
+				return (EAI_NONAME);
+			}
+		inet6_addr:
+			addrsize = sizeof(struct in6_addr);
+			addroff = offsetof(struct sockaddr_in6, sin6_addr);
+			family = AF_INET6;
+
+		common:
+			ai = ai_alloc(family,
+				      ((family == AF_INET6)
+					       ? sizeof(struct sockaddr_in6)
+					       : sizeof(struct sockaddr_in)));
+			if (ai == NULL) {
+				return (EAI_MEMORY);
+			}
+			ai_list = ai;
+			ai->ai_socktype = socktype;
+			SIN(ai->ai_addr)->sin_port = port;
+			memmove((char *)ai->ai_addr + addroff, abuf, addrsize);
+			if (ai->ai_family == AF_INET6) {
+				SIN6(ai->ai_addr)->sin6_scope_id = scopeid;
+			}
+			if ((flags & AI_CANONNAME) != 0) {
+				if (getnameinfo(ai->ai_addr,
+						(socklen_t)ai->ai_addrlen, nbuf,
+						sizeof(nbuf), NULL, 0,
+						NI_NUMERICHOST) == 0)
+				{
+					ai->ai_canonname = strdup(nbuf);
+					if (ai->ai_canonname == NULL) {
+						_freeaddrinfo(ai);
+						return (EAI_MEMORY);
+					}
+				} else {
+					/* XXX raise error? */
+					ai->ai_canonname = NULL;
+				}
+			}
+			goto done;
+		} else if ((flags & AI_NUMERICHOST) != 0) {
+			return (EAI_NONAME);
+		}
+	}
+
+	if (hostname == NULL && (flags & AI_PASSIVE) == 0) {
+		set_order(family, net_order);
+		for (i = 0; i < FOUND_MAX; i++) {
+			if (net_order[i] == NULL) {
+				break;
+			}
+			err = (net_order[i])(hostname, flags, &ai_list,
+					     socktype, port);
+			if (err != 0) {
+				if (ai_list != NULL) {
+					_freeaddrinfo(ai_list);
+					ai_list = NULL;
+				}
+				break;
+			}
+		}
+	} else {
+		err = resolve_name(family, hostname, flags, &ai_list, socktype,
+				   port);
+	}
+
+	if (ai_list == NULL) {
+		if (err == 0) {
+			err = EAI_NONAME;
+		}
+		return (err);
+	}
+
+done:
+	ai_list = ai_reverse(ai_list);
+
+	*res = ai_list;
+	return (0);
+}
+
+typedef struct gai_restrans {
+	dns_clientrestrans_t *xid;
+	bool is_inprogress;
+	int error;
+	struct addrinfo ai_sentinel;
+	struct gai_resstate *resstate;
+} gai_restrans_t;
+
+typedef struct gai_resstate {
+	isc_mem_t *mctx;
+	struct gai_statehead *head;
+	dns_fixedname_t fixedname;
+	dns_name_t *qname;
+	gai_restrans_t *trans4;
+	gai_restrans_t *trans6;
+	ISC_LINK(struct gai_resstate) link;
+} gai_resstate_t;
+
+typedef struct gai_statehead {
+	int ai_family;
+	int ai_flags;
+	int ai_socktype;
+	int ai_port;
+	isc_appctx_t *actx;
+	dns_client_t *dnsclient;
+	isc_mutex_t list_lock;
+	ISC_LIST(struct gai_resstate) resstates;
+	unsigned int activestates;
+} gai_statehead_t;
+
+static isc_result_t
+make_resstate(isc_mem_t *mctx, gai_statehead_t *head, const char *hostname,
+	      const char *domain, gai_resstate_t **statep) {
+	isc_result_t result;
+	gai_resstate_t *state;
+	dns_fixedname_t fixeddomain;
+	dns_name_t *qdomain;
+	unsigned int namelen;
+	isc_buffer_t b;
+	bool need_v4 = false;
+	bool need_v6 = false;
+
+	state = isc_mem_get(mctx, sizeof(*state));
+
+	/* Construct base domain name */
+	namelen = strlen(domain);
+	isc_buffer_constinit(&b, domain, namelen);
+	isc_buffer_add(&b, namelen);
+	qdomain = dns_fixedname_initname(&fixeddomain);
+	result = dns_name_fromtext(qdomain, &b, dns_rootname, 0, NULL);
+	if (result != ISC_R_SUCCESS) {
+		isc_mem_put(mctx, state, sizeof(*state));
+		return (result);
+	}
+
+	/* Construct query name */
+	namelen = strlen(hostname);
+	isc_buffer_constinit(&b, hostname, namelen);
+	isc_buffer_add(&b, namelen);
+	state->qname = dns_fixedname_initname(&state->fixedname);
+	result = dns_name_fromtext(state->qname, &b, qdomain, 0, NULL);
+	if (result != ISC_R_SUCCESS) {
+		isc_mem_put(mctx, state, sizeof(*state));
+		return (result);
+	}
+
+	if (head->ai_family == AF_UNSPEC || head->ai_family == AF_INET) {
+		need_v4 = true;
+	}
+	if (head->ai_family == AF_UNSPEC || head->ai_family == AF_INET6) {
+		need_v6 = true;
+	}
+
+	state->trans6 = NULL;
+	state->trans4 = NULL;
+	if (need_v4) {
+		state->trans4 = isc_mem_get(mctx, sizeof(gai_restrans_t));
+		state->trans4->error = 0;
+		state->trans4->xid = NULL;
+		state->trans4->resstate = state;
+		state->trans4->is_inprogress = true;
+		state->trans4->ai_sentinel.ai_next = NULL;
+	}
+	if (need_v6) {
+		state->trans6 = isc_mem_get(mctx, sizeof(gai_restrans_t));
+		state->trans6->error = 0;
+		state->trans6->xid = NULL;
+		state->trans6->resstate = state;
+		state->trans6->is_inprogress = true;
+		state->trans6->ai_sentinel.ai_next = NULL;
+	}
+
+	state->mctx = mctx;
+	state->head = head;
+	ISC_LINK_INIT(state, link);
+
+	*statep = state;
+
+	return (ISC_R_SUCCESS);
+}
+
+static isc_result_t
+make_resstates(isc_mem_t *mctx, const char *hostname, gai_statehead_t *head,
+	       irs_resconf_t *resconf) {
+	isc_result_t result;
+	irs_resconf_searchlist_t *searchlist;
+	irs_resconf_search_t *searchent;
+	gai_resstate_t *resstate, *resstate0;
+
+	resstate0 = NULL;
+	result = make_resstate(mctx, head, hostname, ".", &resstate0);
+	if (result != ISC_R_SUCCESS) {
+		return (result);
+	}
+
+	searchlist = irs_resconf_getsearchlist(resconf);
+	for (searchent = ISC_LIST_HEAD(*searchlist); searchent != NULL;
+	     searchent = ISC_LIST_NEXT(searchent, link))
+	{
+		resstate = NULL;
+		result = make_resstate(mctx, head, hostname,
+				       (const char *)searchent->domain,
+				       &resstate);
+		if (result != ISC_R_SUCCESS) {
+			break;
+		}
+
+		ISC_LIST_APPEND(head->resstates, resstate, link);
+		head->activestates++;
+	}
+
+	/*
+	 * Insert the original hostname either at the head or the tail of the
+	 * state list, depending on the number of labels contained in the
+	 * original name and the 'ndots' configuration parameter.
+	 */
+	if (dns_name_countlabels(resstate0->qname) >
+	    irs_resconf_getndots(resconf) + 1)
+	{
+		ISC_LIST_PREPEND(head->resstates, resstate0, link);
+	} else {
+		ISC_LIST_APPEND(head->resstates, resstate0, link);
+	}
+	head->activestates++;
+
+	if (result != ISC_R_SUCCESS) {
+		while ((resstate = ISC_LIST_HEAD(head->resstates)) != NULL) {
+			ISC_LIST_UNLINK(head->resstates, resstate, link);
+			if (resstate->trans4 != NULL) {
+				isc_mem_put(mctx, resstate->trans4,
+					    sizeof(*resstate->trans4));
+			}
+			if (resstate->trans6 != NULL) {
+				isc_mem_put(mctx, resstate->trans6,
+					    sizeof(*resstate->trans6));
+			}
+
+			isc_mem_put(mctx, resstate, sizeof(*resstate));
+		}
+	}
+
+	return (result);
+}
+
+static void
+process_answer(isc_task_t *task, isc_event_t *event) {
+	int error = 0, family;
+	gai_restrans_t *trans = event->ev_arg;
+	gai_resstate_t *resstate;
+	dns_clientresevent_t *rev = (dns_clientresevent_t *)event;
+	dns_rdatatype_t qtype;
+	dns_name_t *name;
+	bool wantcname;
+
+	REQUIRE(trans != NULL);
+	resstate = trans->resstate;
+	REQUIRE(resstate != NULL);
+	REQUIRE(task != NULL);
+
+	if (trans == resstate->trans4) {
+		family = AF_INET;
+		qtype = dns_rdatatype_a;
+	} else {
+		INSIST(trans == resstate->trans6);
+		family = AF_INET6;
+		qtype = dns_rdatatype_aaaa;
+	}
+
+	INSIST(trans->is_inprogress);
+	trans->is_inprogress = false;
+
+	switch (rev->result) {
+	case ISC_R_SUCCESS:
+	case DNS_R_NCACHENXDOMAIN: /* treat this as a fatal error? */
+	case DNS_R_NCACHENXRRSET:
+		break;
+	default:
+		switch (rev->vresult) {
+		case DNS_R_SIGINVALID:
+		case DNS_R_SIGEXPIRED:
+		case DNS_R_SIGFUTURE:
+		case DNS_R_KEYUNAUTHORIZED:
+		case DNS_R_MUSTBESECURE:
+		case DNS_R_COVERINGNSEC:
+		case DNS_R_NOTAUTHORITATIVE:
+		case DNS_R_NOVALIDKEY:
+		case DNS_R_NOVALIDDS:
+		case DNS_R_NOVALIDSIG:
+			error = EAI_INSECUREDATA;
+			break;
+		default:
+			error = EAI_FAIL;
+		}
+		goto done;
+	}
+
+	wantcname = ((resstate->head->ai_flags & AI_CANONNAME) != 0);
+
+	/* Parse the response and construct the addrinfo chain */
+	for (name = ISC_LIST_HEAD(rev->answerlist); name != NULL;
+	     name = ISC_LIST_NEXT(name, link))
+	{
+		isc_result_t result;
+		dns_rdataset_t *rdataset;
+		char cname[1024];
+
+		if (wantcname) {
+			isc_buffer_t b;
+
+			isc_buffer_init(&b, cname, sizeof(cname));
+			result = dns_name_totext(name, true, &b);
+			if (result != ISC_R_SUCCESS) {
+				error = EAI_FAIL;
+				goto done;
+			}
+			isc_buffer_putuint8(&b, '\0');
+		}
+
+		for (rdataset = ISC_LIST_HEAD(name->list); rdataset != NULL;
+		     rdataset = ISC_LIST_NEXT(rdataset, link))
+		{
+			if (!dns_rdataset_isassociated(rdataset)) {
+				continue;
+			}
+			if (rdataset->type != qtype) {
+				continue;
+			}
+
+			for (result = dns_rdataset_first(rdataset);
+			     result == ISC_R_SUCCESS;
+			     result = dns_rdataset_next(rdataset))
+			{
+				struct addrinfo *ai;
+				dns_rdata_t rdata;
+				dns_rdata_in_a_t rdata_a;
+				dns_rdata_in_aaaa_t rdata_aaaa;
+
+				ai = ai_alloc(
+					family,
+					((family == AF_INET6)
+						 ? sizeof(struct sockaddr_in6)
+						 : sizeof(struct sockaddr_in)));
+				if (ai == NULL) {
+					error = EAI_MEMORY;
+					goto done;
+				}
+				ai->ai_socktype = resstate->head->ai_socktype;
+				ai->ai_next = trans->ai_sentinel.ai_next;
+				trans->ai_sentinel.ai_next = ai;
+
+				/*
+				 * Set AF-specific parameters
+				 * (IPv4/v6 address/port)
+				 */
+				dns_rdata_init(&rdata);
+				switch (family) {
+				case AF_INET:
+					dns_rdataset_current(rdataset, &rdata);
+					result = dns_rdata_tostruct(
+						&rdata, &rdata_a, NULL);
+					RUNTIME_CHECK(result == ISC_R_SUCCESS);
+					SIN(ai->ai_addr)->sin_port =
+						resstate->head->ai_port;
+					memmove(&SIN(ai->ai_addr)->sin_addr,
+						&rdata_a.in_addr, 4);
+					dns_rdata_freestruct(&rdata_a);
+					break;
+				case AF_INET6:
+					dns_rdataset_current(rdataset, &rdata);
+					result = dns_rdata_tostruct(
+						&rdata, &rdata_aaaa, NULL);
+					RUNTIME_CHECK(result == ISC_R_SUCCESS);
+					SIN6(ai->ai_addr)->sin6_port =
+						resstate->head->ai_port;
+					memmove(&SIN6(ai->ai_addr)->sin6_addr,
+						&rdata_aaaa.in6_addr, 16);
+					dns_rdata_freestruct(&rdata_aaaa);
+					break;
+				}
+
+				if (wantcname) {
+					ai->ai_canonname = strdup(cname);
+					if (ai->ai_canonname == NULL) {
+						error = EAI_MEMORY;
+						goto done;
+					}
+				}
+			}
+		}
+	}
+
+done:
+	dns_client_freeresanswer(resstate->head->dnsclient, &rev->answerlist);
+	dns_client_destroyrestrans(&trans->xid);
+
+	isc_event_free(&event);
+
+	/* Make sure that error == 0 iff we have a non-empty list */
+	if (error == 0) {
+		if (trans->ai_sentinel.ai_next == NULL) {
+			error = EAI_NONAME;
+		}
+	} else {
+		if (trans->ai_sentinel.ai_next != NULL) {
+			_freeaddrinfo(trans->ai_sentinel.ai_next);
+			trans->ai_sentinel.ai_next = NULL;
+		}
+	}
+	trans->error = error;
+
+	/* Check whether we are done */
+	if ((resstate->trans4 == NULL || !resstate->trans4->is_inprogress) &&
+	    (resstate->trans6 == NULL || !resstate->trans6->is_inprogress))
+	{
+		/*
+		 * We're done for this state.  If there is no other outstanding
+		 * state, we can exit.
+		 */
+		resstate->head->activestates--;
+		if (resstate->head->activestates == 0) {
+			isc_app_ctxsuspend(resstate->head->actx);
+			return;
+		}
+
+		/*
+		 * There are outstanding states, but if we are at the head
+		 * of the state list (i.e., at the highest search priority)
+		 * and have any answer, we can stop now by canceling the
+		 * others.
+		 */
+		LOCK(&resstate->head->list_lock);
+		if (resstate == ISC_LIST_HEAD(resstate->head->resstates)) {
+			if ((resstate->trans4 != NULL &&
+			     resstate->trans4->ai_sentinel.ai_next != NULL) ||
+			    (resstate->trans6 != NULL &&
+			     resstate->trans6->ai_sentinel.ai_next != NULL))
+			{
+				gai_resstate_t *rest;
+
+				for (rest = ISC_LIST_NEXT(resstate, link);
+				     rest != NULL;
+				     rest = ISC_LIST_NEXT(rest, link))
+				{
+					if (rest->trans4 != NULL &&
+					    rest->trans4->xid != NULL)
+					{
+						dns_client_cancelresolve(
+							rest->trans4->xid);
+					}
+					if (rest->trans6 != NULL &&
+					    rest->trans6->xid != NULL)
+					{
+						dns_client_cancelresolve(
+							rest->trans6->xid);
+					}
+				}
+			} else {
+				/*
+				 * This search fails, so we move to the tail
+				 * of the list so that the next entry will
+				 * have the highest priority.
+				 */
+				ISC_LIST_UNLINK(resstate->head->resstates,
+						resstate, link);
+				ISC_LIST_APPEND(resstate->head->resstates,
+						resstate, link);
+			}
+		}
+		UNLOCK(&resstate->head->list_lock);
+	}
+}
+
+static int
+resolve_name(int family, const char *hostname, int flags, struct addrinfo **aip,
+	     int socktype, int port) {
+	isc_result_t result;
+	irs_context_t *irsctx;
+	irs_resconf_t *conf;
+	isc_mem_t *mctx;
+	isc_appctx_t *actx;
+	isc_task_t *task;
+	int terror = 0;
+	int error = 0;
+	dns_client_t *client;
+	gai_resstate_t *resstate;
+	gai_statehead_t head;
+	bool all_fail = true;
+
+	/* get IRS context and the associated parameters */
+	irsctx = NULL;
+	result = irs_context_get(&irsctx);
+	if (result != ISC_R_SUCCESS) {
+		return (EAI_FAIL);
+	}
+	actx = irs_context_getappctx(irsctx);
+
+	mctx = irs_context_getmctx(irsctx);
+	task = irs_context_gettask(irsctx);
+	conf = irs_context_getresconf(irsctx);
+	client = irs_context_getdnsclient(irsctx);
+
+	/* construct resolution states */
+	head.activestates = 0;
+	head.ai_family = family;
+	head.ai_socktype = socktype;
+	head.ai_flags = flags;
+	head.ai_port = port;
+	head.actx = actx;
+	head.dnsclient = client;
+	isc_mutex_init(&head.list_lock);
+
+	ISC_LIST_INIT(head.resstates);
+	result = make_resstates(mctx, hostname, &head, conf);
+	if (result != ISC_R_SUCCESS) {
+		isc_mutex_destroy(&head.list_lock);
+		return (EAI_FAIL);
+	}
+
+	LOCK(&head.list_lock);
+	for (resstate = ISC_LIST_HEAD(head.resstates); resstate != NULL;
+	     resstate = ISC_LIST_NEXT(resstate, link))
+	{
+		if (resstate->trans4 != NULL) {
+			result = dns_client_startresolve(
+				client, resstate->qname, dns_rdataclass_in,
+				dns_rdatatype_a, 0, task, process_answer,
+				resstate->trans4, &resstate->trans4->xid);
+			if (result == ISC_R_SUCCESS) {
+				resstate->trans4->is_inprogress = true;
+				all_fail = false;
+			} else {
+				resstate->trans4->is_inprogress = false;
+			}
+		}
+		if (resstate->trans6 != NULL) {
+			result = dns_client_startresolve(
+				client, resstate->qname, dns_rdataclass_in,
+				dns_rdatatype_aaaa, 0, task, process_answer,
+				resstate->trans6, &resstate->trans6->xid);
+			if (result == ISC_R_SUCCESS) {
+				resstate->trans6->is_inprogress = true;
+				all_fail = false;
+			} else {
+				resstate->trans6->is_inprogress = false;
+			}
+		}
+	}
+	UNLOCK(&head.list_lock);
+
+	if (!all_fail) {
+		/* Start all the events */
+		isc_app_ctxrun(actx);
+	} else {
+		error = EAI_FAIL;
+	}
+
+	/* Cleanup */
+	while ((resstate = ISC_LIST_HEAD(head.resstates)) != NULL) {
+		int terror4 = 0, terror6 = 0;
+
+		ISC_LIST_UNLINK(head.resstates, resstate, link);
+
+		if (*aip == NULL) {
+			struct addrinfo *sentinel4 = NULL;
+			struct addrinfo *sentinel6 = NULL;
+
+			if (resstate->trans4 != NULL) {
+				sentinel4 =
+					resstate->trans4->ai_sentinel.ai_next;
+				resstate->trans4->ai_sentinel.ai_next = NULL;
+			}
+			if (resstate->trans6 != NULL) {
+				sentinel6 =
+					resstate->trans6->ai_sentinel.ai_next;
+				resstate->trans6->ai_sentinel.ai_next = NULL;
+			}
+			*aip = ai_concat(sentinel4, sentinel6);
+		}
+
+		if (resstate->trans4 != NULL) {
+			INSIST(resstate->trans4->xid == NULL);
+			terror4 = resstate->trans4->error;
+			isc_mem_put(mctx, resstate->trans4,
+				    sizeof(*resstate->trans4));
+		}
+		if (resstate->trans6 != NULL) {
+			INSIST(resstate->trans6->xid == NULL);
+			terror6 = resstate->trans6->error;
+			isc_mem_put(mctx, resstate->trans6,
+				    sizeof(*resstate->trans6));
+		}
+
+		/*
+		 * If the entire lookup fails, we need to choose an appropriate
+		 * error code from individual codes.  We'll try to provide as
+		 * specific a code as possible.  In general, we are going to
+		 * find an error code other than EAI_NONAME (which is too
+		 * generic and may actually not be problematic in some cases).
+		 * EAI_NONAME will be set below if no better code is found.
+		 */
+		if (terror == 0 || terror == EAI_NONAME) {
+			if (terror4 != 0 && terror4 != EAI_NONAME) {
+				terror = terror4;
+			} else if (terror6 != 0 && terror6 != EAI_NONAME) {
+				terror = terror6;
+			}
+		}
+
+		isc_mem_put(mctx, resstate, sizeof(*resstate));
+	}
+
+	if (*aip == NULL) {
+		error = terror;
+		if (error == 0) {
+			error = EAI_NONAME;
+		}
+	}
+
+#if 1 /*  XXX: enabled for finding leaks.  should be cleaned up later. */
+	isc_app_ctxfinish(actx);
+	irs_context_destroy(&irsctx);
+#endif /* if 1 */
+
+	isc_mutex_destroy(&head.list_lock);
+	return (error);
+}
+
+static void
+set_order(int family,
+	  int (**net_order)(const char *, int, struct addrinfo **, int, int)) {
+	char *order, *tok, *last;
+	int found;
+
+	if (family) {
+		switch (family) {
+		case AF_INET:
+			*net_order++ = add_ipv4;
+			break;
+		case AF_INET6:
+			*net_order++ = add_ipv6;
+			break;
+		}
+	} else {
+		order = getenv("NET_ORDER");
+		found = 0;
+		if (order != NULL) {
+			last = NULL;
+			for (tok = strtok_r(order, ":", &last); tok;
+			     tok = strtok_r(NULL, ":", &last))
+			{
+				if (strcasecmp(tok, "inet6") == 0) {
+					if ((found & FOUND_IPV6) == 0) {
+						*net_order++ = add_ipv6;
+					}
+					found |= FOUND_IPV6;
+				} else if (strcasecmp(tok, "inet") == 0 ||
+					   strcasecmp(tok, "inet4") == 0)
+				{
+					if ((found & FOUND_IPV4) == 0) {
+						*net_order++ = add_ipv4;
+					}
+					found |= FOUND_IPV4;
+				}
+			}
+		}
+
+		/*
+		 * Add in anything that we didn't find.
+		 */
+		if ((found & FOUND_IPV4) == 0) {
+			*net_order++ = add_ipv4;
+		}
+		if ((found & FOUND_IPV6) == 0) {
+			*net_order++ = add_ipv6;
+		}
+	}
+	*net_order = NULL;
+	return;
+}
+
+static char v4_loop[4] = { 127, 0, 0, 1 };
+
+static int
+add_ipv4(const char *hostname, int flags, struct addrinfo **aip, int socktype,
+	 int port) {
+	struct addrinfo *ai;
+
+	UNUSED(hostname);
+	UNUSED(flags);
+
+	ai = ai_clone(*aip, AF_INET); /* don't use ai_clone() */
+	if (ai == NULL) {
+		return (EAI_MEMORY);
+	}
+
+	*aip = ai;
+	ai->ai_socktype = socktype;
+	SIN(ai->ai_addr)->sin_port = port;
+	memmove(&SIN(ai->ai_addr)->sin_addr, v4_loop, 4);
+
+	return (0);
+}
+
+static char v6_loop[16] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 };
+
+static int
+add_ipv6(const char *hostname, int flags, struct addrinfo **aip, int socktype,
+	 int port) {
+	struct addrinfo *ai;
+
+	UNUSED(hostname);
+	UNUSED(flags);
+
+	ai = ai_clone(*aip, AF_INET6); /* don't use ai_clone() */
+	if (ai == NULL) {
+		return (EAI_MEMORY);
+	}
+
+	*aip = ai;
+	ai->ai_socktype = socktype;
+	SIN6(ai->ai_addr)->sin6_port = port;
+	memmove(&SIN6(ai->ai_addr)->sin6_addr, v6_loop, 16);
+
+	return (0);
+}
+
+/*% Free address info. */
+void
+freeaddrinfo(struct addrinfo *ai) {
+	_freeaddrinfo(ai);
+}
+
+static void
+_freeaddrinfo(struct addrinfo *ai) {
+	struct addrinfo *ai_next;
+
+	while (ai != NULL) {
+		ai_next = ai->ai_next;
+		if (ai->ai_addr != NULL) {
+			free(ai->ai_addr);
+		}
+		if (ai->ai_canonname) {
+			free(ai->ai_canonname);
+		}
+		free(ai);
+		ai = ai_next;
+	}
+}
+
+#ifdef AF_LOCAL
+static int
+get_local(const char *name, int socktype, struct addrinfo **res) {
+	struct addrinfo *ai;
+	struct sockaddr_un *slocal;
+
+	if (socktype == 0) {
+		return (EAI_SOCKTYPE);
+	}
+
+	ai = ai_alloc(AF_LOCAL, sizeof(*slocal));
+	if (ai == NULL) {
+		return (EAI_MEMORY);
+	}
+
+	slocal = SLOCAL(ai->ai_addr);
+	strlcpy(slocal->sun_path, name, sizeof(slocal->sun_path));
+
+	ai->ai_socktype = socktype;
+	/*
+	 * ai->ai_flags, ai->ai_protocol, ai->ai_canonname,
+	 * and ai->ai_next were initialized to zero.
+	 */
+
+	*res = ai;
+	return (0);
+}
+#endif /* ifdef AF_LOCAL */
+
+/*!
+ * Allocate an addrinfo structure, and a sockaddr structure
+ * of the specified length.  We initialize:
+ *	ai_addrlen
+ *	ai_family
+ *	ai_addr
+ *	ai_addr->sa_family
+ *	ai_addr->sa_len	(IRS_PLATFORM_HAVESALEN)
+ * and everything else is initialized to zero.
+ */
+static struct addrinfo *
+ai_alloc(int family, int addrlen) {
+	struct addrinfo *ai;
+
+	ai = (struct addrinfo *)calloc(1, sizeof(*ai));
+	if (ai == NULL) {
+		return (NULL);
+	}
+
+	ai->ai_addr = SA(calloc(1, addrlen));
+	if (ai->ai_addr == NULL) {
+		free(ai);
+		return (NULL);
+	}
+	ai->ai_addrlen = addrlen;
+	ai->ai_family = family;
+	ai->ai_addr->sa_family = family;
+#ifdef IRS_PLATFORM_HAVESALEN
+	ai->ai_addr->sa_len = addrlen;
+#endif /* ifdef IRS_PLATFORM_HAVESALEN */
+	return (ai);
+}
+
+static struct addrinfo *
+ai_clone(struct addrinfo *oai, int family) {
+	struct addrinfo *ai;
+
+	ai = ai_alloc(family,
+		      ((family == AF_INET6) ? sizeof(struct sockaddr_in6)
+					    : sizeof(struct sockaddr_in)));
+
+	if (ai == NULL) {
+		return (NULL);
+	}
+	if (oai == NULL) {
+		return (ai);
+	}
+
+	ai->ai_flags = oai->ai_flags;
+	ai->ai_socktype = oai->ai_socktype;
+	ai->ai_protocol = oai->ai_protocol;
+	ai->ai_canonname = NULL;
+	ai->ai_next = oai;
+	return (ai);
+}
+
+static struct addrinfo *
+ai_reverse(struct addrinfo *oai) {
+	struct addrinfo *nai, *tai;
+
+	nai = NULL;
+
+	while (oai != NULL) {
+		/*
+		 * Grab one off the old list.
+		 */
+		tai = oai;
+		oai = oai->ai_next;
+		/*
+		 * Put it on the front of the new list.
+		 */
+		tai->ai_next = nai;
+		nai = tai;
+	}
+	return (nai);
+}
+
+static struct addrinfo *
+ai_concat(struct addrinfo *ai1, struct addrinfo *ai2) {
+	struct addrinfo *ai_tmp;
+
+	if (ai1 == NULL) {
+		return (ai2);
+	} else if (ai2 == NULL) {
+		return (ai1);
+	}
+
+	for (ai_tmp = ai1; ai_tmp != NULL && ai_tmp->ai_next != NULL;
+	     ai_tmp = ai_tmp->ai_next)
+	{
+	}
+
+	ai_tmp->ai_next = ai2;
+
+	return (ai1);
+}
diff --git a/lib/irs/getnameinfo.c b/lib/irs/getnameinfo.c
new file mode 100644
index 0000000..62c7cea
--- /dev/null
+++ b/lib/irs/getnameinfo.c
@@ -0,0 +1,438 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ *
+ * 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 https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+/*! \file */
+
+/*
+ * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
+ * 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. Neither the name of the project 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 PROJECT 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 PROJECT 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.
+ */
+
+/**
+ *    getnameinfo() returns the hostname for the struct sockaddr sa which is
+ *    salen bytes long. The hostname is of length hostlen and is returned via
+ *    *host. The maximum length of the hostname is 1025 bytes: #NI_MAXHOST.
+ *
+ *    The name of the service associated with the port number in sa is
+ *    returned in *serv. It is servlen bytes long. The maximum length of the
+ *    service name is #NI_MAXSERV - 32 bytes.
+ *
+ *    The flags argument sets the following bits:
+ *
+ * \li   #NI_NOFQDN:
+ *           A fully qualified domain name is not required for local hosts.
+ *           The local part of the fully qualified domain name is returned
+ *           instead.
+ *
+ * \li   #NI_NUMERICHOST
+ *           Return the address in numeric form, as if calling inet_ntop(),
+ *           instead of a host name.
+ *
+ * \li   #NI_NAMEREQD
+ *           A name is required. If the hostname cannot be found in the DNS
+ *           and this flag is set, a non-zero error code is returned. If the
+ *           hostname is not found and the flag is not set, the address is
+ *           returned in numeric form.
+ *
+ * \li   #NI_NUMERICSERV
+ *           The service name is returned as a digit string representing the
+ *           port number.
+ *
+ * \li   #NI_DGRAM
+ *           Specifies that the service being looked up is a datagram
+ *           service, and causes getservbyport() to be called with a second
+ *           argument of "udp" instead of its default of "tcp". This is
+ *           required for the few ports (512-514) that have different
+ *           services for UDP and TCP.
+ *
+ * \section getnameinfo_return Return Values
+ *
+ *    getnameinfo() returns 0 on success or a non-zero error code if
+ *    an error occurs.
+ *
+ * \section getname_see See Also
+ *
+ *    RFC3493, getservbyport(),
+ *    getnamebyaddr(). inet_ntop().
+ */
+
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+
+#include <isc/netaddr.h>
+#include <isc/print.h>
+#include <isc/sockaddr.h>
+#include <isc/string.h>
+#include <isc/util.h>
+
+#include <dns/byaddr.h>
+#include <dns/client.h>
+#include <dns/fixedname.h>
+#include <dns/name.h>
+#include <dns/rdata.h>
+#include <dns/rdataset.h>
+#include <dns/rdatastruct.h>
+#include <dns/result.h>
+
+#include <irs/context.h>
+#include <irs/netdb.h>
+
+#define SUCCESS 0
+
+/*% afd structure definition */
+static struct afd {
+	int a_af;
+	size_t a_addrlen;
+	size_t a_socklen;
+} afdl[] = {
+	/*!
+	 * First entry is linked last...
+	 */
+	{ AF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in) },
+	{ AF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6) },
+	{ 0, 0, 0 },
+};
+
+/*!
+ * The test against 0 is there to keep the Solaris compiler
+ * from complaining about "end-of-loop code not reached".
+ */
+#define ERR(code)                     \
+	do {                          \
+		result = (code);      \
+		if (result != 0)      \
+			goto cleanup; \
+	} while (0)
+
+#ifdef _WIN32
+int
+getnameinfo(const struct sockaddr *sa, socklen_t salen, char *host,
+	    DWORD hostlen, char *serv, DWORD servlen, int flags) {
+#else
+int
+getnameinfo(const struct sockaddr *sa, socklen_t salen, char *host,
+	    socklen_t hostlen, char *serv, socklen_t servlen, int flags) {
+#endif
+	struct afd *afd = NULL;
+	struct servent *sp;
+	unsigned short port = 0;
+#ifdef IRS_PLATFORM_HAVESALEN
+	size_t len;
+#endif /* ifdef IRS_PLATFORM_HAVESALEN */
+	int family, i;
+	const void *addr = NULL;
+	char *p;
+#if 0
+	unsigned long v4a;
+	unsigned char pfx;
+#endif /* if 0 */
+	char numserv[sizeof("65000")];
+	char numaddr[sizeof("abcd:abcd:abcd:abcd:abcd:abcd:255.255.255.255") +
+		     1 + sizeof("4294967295")];
+	const char *proto;
+	int result = SUCCESS;
+
+	if (sa == NULL) {
+		ERR(EAI_FAIL);
+	}
+
+#ifdef IRS_PLATFORM_HAVESALEN
+	len = sa->sa_len;
+	if (len != salen) {
+		ERR(EAI_FAIL);
+	}
+#endif /* ifdef IRS_PLATFORM_HAVESALEN */
+
+	family = sa->sa_family;
+	for (i = 0; afdl[i].a_af; i++) {
+		if (afdl[i].a_af == family) {
+			{
+				afd = &afdl[i];
+				goto found;
+			}
+		}
+	}
+	ERR(EAI_FAMILY);
+
+found:
+	if (salen != afd->a_socklen) {
+		ERR(EAI_FAIL);
+	}
+
+	switch (family) {
+	case AF_INET:
+		port = ((const struct sockaddr_in *)sa)->sin_port;
+		addr = &((const struct sockaddr_in *)sa)->sin_addr.s_addr;
+		break;
+
+	case AF_INET6:
+		port = ((const struct sockaddr_in6 *)sa)->sin6_port;
+		addr = ((const struct sockaddr_in6 *)sa)->sin6_addr.s6_addr;
+		break;
+
+	default:
+		UNREACHABLE();
+	}
+	proto = ((flags & NI_DGRAM) != 0) ? "udp" : "tcp";
+
+	if (serv == NULL || servlen == 0U) {
+		/*
+		 * Caller does not want service.
+		 */
+	} else if ((flags & NI_NUMERICSERV) != 0 ||
+		   (sp = getservbyport(port, proto)) == NULL)
+	{
+		snprintf(numserv, sizeof(numserv), "%d", ntohs(port));
+		if ((strlen(numserv) + 1) > servlen) {
+			ERR(EAI_OVERFLOW);
+		}
+		strlcpy(serv, numserv, servlen);
+	} else {
+		if ((strlen(sp->s_name) + 1) > servlen) {
+			ERR(EAI_OVERFLOW);
+		}
+		strlcpy(serv, sp->s_name, servlen);
+	}
+
+#if 0
+	switch (sa->sa_family) {
+	case AF_INET:
+		v4a = ((struct sockaddr_in *)sa)->sin_addr.s_addr;
+		if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a)) {
+			flags |= NI_NUMERICHOST;
+		}
+		v4a >>= IN_CLASSA_NSHIFT;
+		if (v4a == 0 || v4a == IN_LOOPBACKNET) {
+			flags |= NI_NUMERICHOST;
+		}
+		break;
+
+	case AF_INET6:
+		pfx = ((struct sockaddr_in6 *)sa)->sin6_addr.s6_addr[0];
+		if (pfx == 0 || pfx == 0xfe || pfx == 0xff) {
+			flags |= NI_NUMERICHOST;
+		}
+		break;
+	}
+#endif /* if 0 */
+
+	if (host == NULL || hostlen == 0U) {
+		/*
+		 * do nothing in this case.
+		 * in case you are wondering if "&&" is more correct than
+		 * "||" here: RFC3493 says that host == NULL or hostlen == 0
+		 * means that the caller does not want the result.
+		 */
+	} else if ((flags & NI_NUMERICHOST) != 0) {
+		if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr)) ==
+		    NULL)
+		{
+			ERR(EAI_SYSTEM);
+		}
+#if defined(IRS_HAVE_SIN6_SCOPE_ID)
+		if (afd->a_af == AF_INET6 &&
+		    ((const struct sockaddr_in6 *)sa)->sin6_scope_id)
+		{
+			char *p = numaddr + strlen(numaddr);
+			const char *stringscope = NULL;
+#ifdef VENDOR_SPECIFIC
+			/*
+			 * Vendors may want to add support for
+			 * non-numeric scope identifier.
+			 */
+			stringscope = foo;
+#endif /* ifdef VENDOR_SPECIFIC */
+			if (stringscope == NULL) {
+				snprintf(p, sizeof(numaddr) - (p - numaddr),
+					 "%%%u",
+					 ((const struct sockaddr_in6 *)sa)
+						 ->sin6_scope_id);
+			} else {
+				snprintf(p, sizeof(numaddr) - (p - numaddr),
+					 "%%%s", stringscope);
+			}
+		}
+#endif /* if defined(IRS_HAVE_SIN6_SCOPE_ID) */
+		if (strlen(numaddr) + 1 > hostlen) {
+			ERR(EAI_OVERFLOW);
+		}
+		strlcpy(host, numaddr, hostlen);
+	} else {
+		isc_netaddr_t netaddr;
+		dns_fixedname_t ptrfname;
+		dns_name_t *ptrname;
+		irs_context_t *irsctx = NULL;
+		dns_client_t *client;
+		bool found = false;
+		dns_namelist_t answerlist;
+		dns_rdataset_t *rdataset;
+		isc_region_t hostregion;
+		char hoststr[1024]; /* is this enough? */
+		isc_result_t iresult;
+
+		/* Get IRS context and the associated DNS client object */
+		iresult = irs_context_get(&irsctx);
+		if (iresult != ISC_R_SUCCESS) {
+			ERR(EAI_FAIL);
+		}
+		client = irs_context_getdnsclient(irsctx);
+
+		/* Make query name */
+		isc_netaddr_fromsockaddr(&netaddr, (const isc_sockaddr_t *)sa);
+		ptrname = dns_fixedname_initname(&ptrfname);
+		iresult = dns_byaddr_createptrname(&netaddr, 0, ptrname);
+		if (iresult != ISC_R_SUCCESS) {
+			ERR(EAI_FAIL);
+		}
+
+		/* Get the PTR RRset */
+		ISC_LIST_INIT(answerlist);
+		iresult = dns_client_resolve(client, ptrname, dns_rdataclass_in,
+					     dns_rdatatype_ptr, 0, &answerlist);
+		switch (iresult) {
+		case ISC_R_SUCCESS:
+		/*
+		 * a 'non-existent' error is not necessarily fatal for
+		 * getnameinfo().
+		 */
+		case DNS_R_NCACHENXDOMAIN:
+		case DNS_R_NCACHENXRRSET:
+			break;
+		case DNS_R_SIGINVALID:
+		case DNS_R_SIGEXPIRED:
+		case DNS_R_SIGFUTURE:
+		case DNS_R_KEYUNAUTHORIZED:
+		case DNS_R_MUSTBESECURE:
+		case DNS_R_COVERINGNSEC:
+		case DNS_R_NOTAUTHORITATIVE:
+		case DNS_R_NOVALIDKEY:
+		case DNS_R_NOVALIDDS:
+		case DNS_R_NOVALIDSIG:
+			/*
+			 * Don't use ERR as GCC 7 wants to raise a
+			 * warning with ERR about possible falling
+			 * through which is impossible.
+			 */
+			result = EAI_INSECUREDATA;
+			goto cleanup;
+		default:
+			ERR(EAI_FAIL);
+		}
+
+		/* Parse the answer for the hostname */
+		for (ptrname = ISC_LIST_HEAD(answerlist); ptrname != NULL;
+		     ptrname = ISC_LIST_NEXT(ptrname, link))
+		{
+			for (rdataset = ISC_LIST_HEAD(ptrname->list);
+			     rdataset != NULL;
+			     rdataset = ISC_LIST_NEXT(rdataset, link))
+			{
+				if (!dns_rdataset_isassociated(rdataset)) {
+					continue;
+				}
+				if (rdataset->type != dns_rdatatype_ptr) {
+					continue;
+				}
+
+				for (iresult = dns_rdataset_first(rdataset);
+				     iresult == ISC_R_SUCCESS;
+				     iresult = dns_rdataset_next(rdataset))
+				{
+					dns_rdata_t rdata;
+					dns_rdata_ptr_t rdata_ptr;
+					isc_buffer_t b;
+
+					dns_rdata_init(&rdata);
+					dns_rdataset_current(rdataset, &rdata);
+					dns_rdata_tostruct(&rdata, &rdata_ptr,
+							   NULL);
+
+					isc_buffer_init(&b, hoststr,
+							sizeof(hoststr));
+					iresult = dns_name_totext(
+						&rdata_ptr.ptr, true, &b);
+					dns_rdata_freestruct(&rdata_ptr);
+					if (iresult == ISC_R_SUCCESS) {
+						/*
+						 * We ignore the rest of the
+						 * answer.  After all,
+						 * getnameinfo() can return
+						 * at most one hostname.
+						 */
+						found = true;
+						isc_buffer_usedregion(
+							&b, &hostregion);
+						goto ptrfound;
+					}
+				}
+			}
+		}
+	ptrfound:
+		dns_client_freeresanswer(client, &answerlist);
+		if (found) {
+			if ((flags & NI_NOFQDN) != 0) {
+				p = strchr(hoststr, '.');
+				if (p) {
+					*p = '\0';
+				}
+			}
+			if (hostregion.length + 1 > hostlen) {
+				ERR(EAI_OVERFLOW);
+			}
+			snprintf(host, hostlen, "%.*s", (int)hostregion.length,
+				 (char *)hostregion.base);
+		} else {
+			if ((flags & NI_NAMEREQD) != 0) {
+				ERR(EAI_NONAME);
+			}
+			if (inet_ntop(afd->a_af, addr, numaddr,
+				      sizeof(numaddr)) == NULL)
+			{
+				ERR(EAI_SYSTEM);
+			}
+			if ((strlen(numaddr) + 1) > hostlen) {
+				ERR(EAI_OVERFLOW);
+			}
+			strlcpy(host, numaddr, hostlen);
+		}
+	}
+	result = SUCCESS;
+
+cleanup:
+	return (result);
+}
diff --git a/lib/irs/include/.clang-format b/lib/irs/include/.clang-format
new file mode 120000
index 0000000..0e62f72
--- /dev/null
+++ b/lib/irs/include/.clang-format
@@ -0,0 +1 @@
+../../../.clang-format.headers
\ No newline at end of file
diff --git a/lib/irs/include/Makefile.in b/lib/irs/include/Makefile.in
new file mode 100644
index 0000000..53a5348
--- /dev/null
+++ b/lib/irs/include/Makefile.in
@@ -0,0 +1,19 @@
+# Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+#
+# SPDX-License-Identifier: MPL-2.0
+#
+# 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 https://mozilla.org/MPL/2.0/.
+#
+# See the COPYRIGHT file distributed with this work for additional
+# information regarding copyright ownership.
+
+srcdir =	@srcdir@
+VPATH =		@srcdir@
+top_srcdir =	@top_srcdir@
+
+SUBDIRS =	irs
+TARGETS =
+
+@BIND9_MAKE_RULES@
diff --git a/lib/irs/include/irs/Makefile.in b/lib/irs/include/irs/Makefile.in
new file mode 100644
index 0000000..fb37979
--- /dev/null
+++ b/lib/irs/include/irs/Makefile.in
@@ -0,0 +1,46 @@
+# Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+#
+# SPDX-License-Identifier: MPL-2.0
+#
+# 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 https://mozilla.org/MPL/2.0/.
+#
+# See the COPYRIGHT file distributed with this work for additional
+# information regarding copyright ownership.
+
+srcdir =	@srcdir@
+VPATH =		@srcdir@
+top_srcdir =	@top_srcdir@
+
+#
+# Only list headers that are to be installed and are not
+# machine generated.  The latter are handled specially in the
+# install target below.
+#
+HEADERS =	context.h dnsconf.h resconf.h types.h version.h
+
+SUBDIRS =
+TARGETS =
+
+@BIND9_MAKE_RULES@
+
+installdirs:
+	$(SHELL) ${top_srcdir}/mkinstalldirs ${DESTDIR}${includedir}/irs
+
+install:: installdirs
+	for i in ${HEADERS}; do \
+		${INSTALL_DATA} ${srcdir}/$$i ${DESTDIR}${includedir}/irs || exit 1; \
+	done
+	${INSTALL_DATA} netdb.h ${DESTDIR}${includedir}/irs
+	${INSTALL_DATA} platform.h ${DESTDIR}${includedir}/irs
+
+uninstall::
+	rm -f ${DESTDIR}${includedir}/irs/platform.h
+	rm -f ${DESTDIR}${includedir}/irs/netdb.h
+	for i in ${HEADERS}; do \
+		rm -f ${DESTDIR}${includedir}/irs/$$i || exit 1; \
+	done
+
+distclean::
+	rm -f netdb.h platform.h
diff --git a/lib/irs/include/irs/context.h b/lib/irs/include/irs/context.h
new file mode 100644
index 0000000..c2d800a
--- /dev/null
+++ b/lib/irs/include/irs/context.h
@@ -0,0 +1,155 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ *
+ * 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 https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+#ifndef IRS_CONTEXT_H
+#define IRS_CONTEXT_H 1
+
+/*! \file
+ *
+ * \brief
+ * The IRS context module provides an abstract interface to the DNS library
+ * with an application.  An IRS context object initializes and holds various
+ * resources used in the DNS library.
+ */
+
+#include <dns/types.h>
+
+#include <irs/types.h>
+
+ISC_LANG_BEGINDECLS
+
+isc_result_t
+irs_context_create(irs_context_t **contextp);
+/*%<
+ * Create an IRS context.  It internally initializes the ISC and DNS libraries
+ * (if not yet), creates a DNS client object and initializes the client using
+ * the configuration files parsed via the 'resconf' and 'dnsconf' IRS modules.
+ * Some of the internally initialized objects can be used by the application
+ * via irs_context_getxxx() functions (see below).
+ *
+ * Requires:
+ *
+ *\li	contextp != NULL && *contextp == NULL.
+ */
+
+isc_result_t
+irs_context_get(irs_context_t **contextp);
+/*%<
+ * Return an IRS context for the calling thread.  If no IRS context is
+ * associated to the thread, this function creates a new one by calling
+ * irs_context_create(), and associates it with the thread as a thread specific
+ * data value.  This function is provided for standard libraries that are
+ * expected to be thread-safe but do not accept an appropriate IRS context
+ * as a library parameter, e.g., getaddrinfo().
+ *
+ * Requires:
+ *
+ *\li	contextp != NULL && *contextp == NULL.
+ */
+
+void
+irs_context_destroy(irs_context_t **contextp);
+/*%<
+ * Destroy an IRS context.
+ *
+ * Requires:
+ *
+ *\li	'*contextp' is a valid IRS context.
+ *
+ * Ensures:
+ *\li	'*contextp' == NULL.
+ */
+
+isc_mem_t *
+irs_context_getmctx(irs_context_t *context);
+/*%<
+ * Return the memory context held in the context.
+ *
+ * Requires:
+ *
+ *\li	'context' is a valid IRS context.
+ */
+
+isc_appctx_t *
+irs_context_getappctx(irs_context_t *context);
+/*%<
+ * Return the application context held in the context.
+ *
+ * Requires:
+ *
+ *\li	'context' is a valid IRS context.
+ */
+
+isc_taskmgr_t *
+irs_context_gettaskmgr(irs_context_t *context);
+/*%<
+ * Return the task manager held in the context.
+ *
+ * Requires:
+ *
+ *\li	'context' is a valid IRS context.
+ */
+
+isc_timermgr_t *
+irs_context_gettimermgr(irs_context_t *context);
+/*%<
+ * Return the timer manager held in the context.
+ *
+ * Requires:
+ *
+ *\li	'context' is a valid IRS context.
+ */
+
+isc_task_t *
+irs_context_gettask(irs_context_t *context);
+/*%<
+ * Return the task object held in the context.
+ *
+ * Requires:
+ *
+ *\li	'context' is a valid IRS context.
+ */
+
+dns_client_t *
+irs_context_getdnsclient(irs_context_t *context);
+/*%<
+ * Return the DNS client object held in the context.
+ *
+ * Requires:
+ *
+ *\li	'context' is a valid IRS context.
+ */
+
+irs_resconf_t *
+irs_context_getresconf(irs_context_t *context);
+/*%<
+ * Return the resolver configuration object held in the context.
+ *
+ * Requires:
+ *
+ *\li	'context' is a valid IRS context.
+ */
+
+irs_dnsconf_t *
+irs_context_getdnsconf(irs_context_t *context);
+/*%<
+ * Return the advanced DNS configuration object held in the context.
+ *
+ * Requires:
+ *
+ *\li	'context' is a valid IRS context.
+ */
+
+ISC_LANG_ENDDECLS
+
+#endif /* IRS_CONTEXT_H */
diff --git a/lib/irs/include/irs/dnsconf.h b/lib/irs/include/irs/dnsconf.h
new file mode 100644
index 0000000..7456b89
--- /dev/null
+++ b/lib/irs/include/irs/dnsconf.h
@@ -0,0 +1,92 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ *
+ * 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 https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+#ifndef IRS_DNSCONF_H
+#define IRS_DNSCONF_H 1
+
+/*! \file
+ *
+ * \brief
+ * The IRS dnsconf module parses an "advanced" configuration file related to
+ * the DNS library, such as trust anchors for DNSSEC validation, and creates
+ * the corresponding configuration objects for the DNS library modules.
+ *
+ * Notes:
+ * This module is very experimental and the configuration syntax or library
+ * interfaces may change in future versions.  Currently, only static
+ * key configuration is supported; "trusted-keys" and "trust-anchors"/
+ * "managed-keys" statements will be parsed exactly as they are in
+ * named.conf, except that "trust-anchors" and "managed-keys" entries will
+ * be treated as if they were configured with "static-key", even if they
+ * were actually configured with "initial-key".
+ */
+
+#include <irs/types.h>
+
+/*%
+ * A compound structure storing DNS key information mainly for DNSSEC
+ * validation.  A dns_key_t object will be created using the 'keyname' and
+ * 'keydatabuf' members with the dst_key_fromdns() function.
+ */
+typedef struct irs_dnsconf_dnskey {
+	dns_name_t   *keyname;
+	isc_buffer_t *keydatabuf;
+	ISC_LINK(struct irs_dnsconf_dnskey) link;
+} irs_dnsconf_dnskey_t;
+
+typedef ISC_LIST(irs_dnsconf_dnskey_t) irs_dnsconf_dnskeylist_t;
+
+ISC_LANG_BEGINDECLS
+
+isc_result_t
+irs_dnsconf_load(isc_mem_t *mctx, const char *filename, irs_dnsconf_t **confp);
+/*%<
+ * Load the "advanced" DNS configuration file 'filename' in the "dns.conf"
+ * format, and create a new irs_dnsconf_t object from the configuration.
+ *
+ * Requires:
+ *
+ *\li	'mctx' is a valid memory context.
+ *
+ *\li	'filename' != NULL
+ *
+ *\li	'confp' != NULL && '*confp' == NULL
+ */
+
+void
+irs_dnsconf_destroy(irs_dnsconf_t **confp);
+/*%<
+ * Destroy the dnsconf object.
+ *
+ * Requires:
+ *
+ *\li	'*confp' is a valid dnsconf object.
+ *
+ * Ensures:
+ *
+ *\li	*confp == NULL
+ */
+
+irs_dnsconf_dnskeylist_t *
+irs_dnsconf_gettrustedkeys(irs_dnsconf_t *conf);
+/*%<
+ * Return a list of key information stored in 'conf'.
+ *
+ * Requires:
+ *
+ *\li	'conf' is a valid dnsconf object.
+ */
+
+ISC_LANG_ENDDECLS
+
+#endif /* IRS_DNSCONF_H */
diff --git a/lib/irs/include/irs/netdb.h.in b/lib/irs/include/irs/netdb.h.in
new file mode 100644
index 0000000..c3b4dae
--- /dev/null
+++ b/lib/irs/include/irs/netdb.h.in
@@ -0,0 +1,193 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ *
+ * 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 https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+/*! \file */
+
+#ifndef IRS_NETDB_H
+#define IRS_NETDB_H 1
+
+#include <stddef.h>	/* Required on FreeBSD (and  others?) for size_t. */
+#include <netdb.h>	/* Contractual provision. */
+
+/*
+ * Undefine all #defines we are interested in as <netdb.h> may or may not have
+ * defined them.
+ */
+
+/*
+ * Error return codes from gethostbyname() and gethostbyaddr()
+ * (left in extern int h_errno).
+ */
+
+#undef	NETDB_INTERNAL
+#undef	NETDB_SUCCESS
+#undef	HOST_NOT_FOUND
+#undef	TRY_AGAIN
+#undef	NO_RECOVERY
+#undef	NO_DATA
+#undef	NO_ADDRESS
+
+#define	NETDB_INTERNAL	-1	/* see errno */
+#define	NETDB_SUCCESS	0	/* no problem */
+#define	HOST_NOT_FOUND	1 /* Authoritative Answer Host not found */
+#define	TRY_AGAIN	2 /* Non-Authoritive Host not found, or SERVERFAIL */
+#define	NO_RECOVERY	3 /* Non recoverable errors, FORMERR, REFUSED, NOTIMP */
+#define	NO_DATA		4 /* Valid name, no data record of requested type */
+#define	NO_ADDRESS	NO_DATA		/* no address, look for MX record */
+
+/*
+ * Error return codes from getaddrinfo().  EAI_INSECUREDATA is our own extension
+ * and it's very unlikely to be already defined, but undef it just in case; it
+ * at least doesn't do any harm.
+ */
+
+#undef	EAI_ADDRFAMILY
+#undef	EAI_AGAIN
+#undef	EAI_BADFLAGS
+#undef	EAI_FAIL
+#undef	EAI_FAMILY
+#undef	EAI_MEMORY
+#undef	EAI_NODATA
+#undef	EAI_NONAME
+#undef	EAI_SERVICE
+#undef	EAI_SOCKTYPE
+#undef	EAI_SYSTEM
+#undef	EAI_BADHINTS
+#undef	EAI_PROTOCOL
+#undef	EAI_OVERFLOW
+#undef	EAI_INSECUREDATA
+#undef	EAI_MAX
+
+#define	EAI_ADDRFAMILY	 1	/* address family for hostname not supported */
+#define	EAI_AGAIN	 2	/* temporary failure in name resolution */
+#define	EAI_BADFLAGS	 3	/* invalid value for ai_flags */
+#define	EAI_FAIL	 4	/* non-recoverable failure in name resolution */
+#define	EAI_FAMILY	 5	/* ai_family not supported */
+#define	EAI_MEMORY	 6	/* memory allocation failure */
+#define	EAI_NODATA	 7	/* no address associated with hostname */
+#define	EAI_NONAME	 8	/* hostname nor servname provided, or not known */
+#define	EAI_SERVICE	 9	/* servname not supported for ai_socktype */
+#define	EAI_SOCKTYPE	10	/* ai_socktype not supported */
+#define	EAI_SYSTEM	11	/* system error returned in errno */
+#define EAI_BADHINTS	12
+#define EAI_PROTOCOL	13
+#define EAI_OVERFLOW	14
+#define EAI_INSECUREDATA 15
+#define EAI_MAX		16
+
+/*
+ * Flag values for getaddrinfo()
+ */
+#undef	AI_PASSIVE
+#undef	AI_CANONNAME
+#undef	AI_NUMERICHOST
+
+#define	AI_PASSIVE	0x00000001
+#define	AI_CANONNAME	0x00000002
+#define AI_NUMERICHOST	0x00000004
+
+/*
+ * Flag values for getipnodebyname()
+ */
+#undef AI_V4MAPPED
+#undef AI_ALL
+#undef AI_ADDRCONFIG
+#undef AI_DEFAULT
+
+#define AI_V4MAPPED	0x00000008
+#define AI_ALL		0x00000010
+#define AI_ADDRCONFIG	0x00000020
+#define AI_DEFAULT	(AI_V4MAPPED|AI_ADDRCONFIG)
+
+/*
+ * Constants for getnameinfo()
+ */
+#undef	NI_MAXHOST
+#undef	NI_MAXSERV
+
+#define	NI_MAXHOST	1025
+#define	NI_MAXSERV	32
+
+/*
+ * Flag values for getnameinfo()
+ */
+#undef	NI_NOFQDN
+#undef	NI_NUMERICHOST
+#undef	NI_NAMEREQD
+#undef	NI_NUMERICSERV
+#undef	NI_DGRAM
+#undef	NI_NUMERICSCOPE
+
+#define	NI_NOFQDN	0x00000001
+#define	NI_NUMERICHOST	0x00000002
+#define	NI_NAMEREQD	0x00000004
+#define	NI_NUMERICSERV	0x00000008
+#define	NI_DGRAM	0x00000010
+
+/*
+ * Define to map into irs_ namespace.
+ */
+
+#define IRS_NAMESPACE
+
+#ifdef IRS_NAMESPACE
+
+/*
+ * Use our versions not the ones from the C library.
+ */
+
+#ifdef getnameinfo
+#undef getnameinfo
+#endif
+#define getnameinfo irs_getnameinfo
+
+#ifdef getaddrinfo
+#undef getaddrinfo
+#endif
+#define getaddrinfo irs_getaddrinfo
+
+#ifdef freeaddrinfo
+#undef freeaddrinfo
+#endif
+#define freeaddrinfo irs_freeaddrinfo
+
+#ifdef gai_strerror
+#undef gai_strerror
+#endif
+#define gai_strerror irs_gai_strerror
+
+int
+getaddrinfo(const char *hostname, const char *servname,
+	    const struct addrinfo *hints, struct addrinfo **res);
+
+int
+getnameinfo(const struct sockaddr *sa, socklen_t salen,
+	    char *host, socklen_t hostlen,
+	    char *serv, socklen_t servlen,
+	    int flags);
+
+void freeaddrinfo (struct addrinfo *ai);
+
+const char *
+gai_strerror(int ecode);
+
+#endif /* IRS_NAMESPACE */
+
+/*
+ * Tell Emacs to use C mode on this file.
+ * Local variables:
+ * mode: c
+ * End:
+ */
+
+#endif /* IRS_NETDB_H */
diff --git a/lib/irs/include/irs/platform.h.in b/lib/irs/include/irs/platform.h.in
new file mode 100644
index 0000000..54bae37
--- /dev/null
+++ b/lib/irs/include/irs/platform.h.in
@@ -0,0 +1,32 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ *
+ * 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 https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+/*! \file */
+
+#ifndef IRS_PLATFORM_H
+#define IRS_PLATFORM_H 1
+
+/*****
+ ***** Platform-dependent defines.
+ *****/
+
+#define LIBIRS_EXTERNAL_DATA
+
+/*
+ * Tell Emacs to use C mode on this file.
+ * Local Variables:
+ * mode: c
+ * End:
+ */
+
+#endif /* IRS_PLATFORM_H */
diff --git a/lib/irs/include/irs/resconf.h b/lib/irs/include/irs/resconf.h
new file mode 100644
index 0000000..424b795
--- /dev/null
+++ b/lib/irs/include/irs/resconf.h
@@ -0,0 +1,118 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ *
+ * 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 https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+#ifndef IRS_RESCONF_H
+#define IRS_RESCONF_H 1
+
+/*! \file
+ *
+ * \brief
+ * The IRS resconf module parses the legacy "/etc/resolv.conf" file and
+ * creates the corresponding configuration objects for the DNS library
+ * modules.
+ */
+
+#include <irs/types.h>
+
+/*%
+ * A DNS search list specified in the 'domain' or 'search' statements
+ * in the "resolv.conf" file.
+ */
+typedef struct irs_resconf_search {
+	char *domain;
+	ISC_LINK(struct irs_resconf_search) link;
+} irs_resconf_search_t;
+
+typedef ISC_LIST(irs_resconf_search_t) irs_resconf_searchlist_t;
+
+ISC_LANG_BEGINDECLS
+
+isc_result_t
+irs_resconf_load(isc_mem_t *mctx, const char *filename, irs_resconf_t **confp);
+/*%<
+ * Load the resolver configuration file 'filename' in the "resolv.conf" format,
+ * and create a new irs_resconf_t object from the configuration.  If the file
+ * is not found ISC_R_FILENOTFOUND is returned with the structure initialized
+ * as if file contained only:
+ *
+ *	nameserver ::1
+ *	nameserver 127.0.0.1
+ *
+ * Notes:
+ *
+ *\li	Currently, only the following options are supported:
+ *	nameserver, domain, search, sortlist, ndots, and options.
+ *	In addition, 'sortlist' is not actually effective; it's parsed, but
+ *	the application cannot use the configuration.
+ *
+ * Returns:
+ * \li	ISC_R_SUCCESS on success
+ * \li  ISC_R_FILENOTFOUND if the file was not found. *confp will be valid.
+ * \li  other on error.
+ *
+ * Requires:
+ *
+ *\li	'mctx' is a valid memory context.
+ *
+ *\li	'filename' != NULL
+ *
+ *\li	'confp' != NULL && '*confp' == NULL
+ */
+
+void
+irs_resconf_destroy(irs_resconf_t **confp);
+/*%<
+ * Destroy the resconf object.
+ *
+ * Requires:
+ *
+ *\li	'*confp' is a valid resconf object.
+ *
+ * Ensures:
+ *
+ *\li	*confp == NULL
+ */
+
+isc_sockaddrlist_t *
+irs_resconf_getnameservers(irs_resconf_t *conf);
+/*%<
+ * Return a list of name server addresses stored in 'conf'.
+ *
+ * Requires:
+ *
+ *\li	'conf' is a valid resconf object.
+ */
+
+irs_resconf_searchlist_t *
+irs_resconf_getsearchlist(irs_resconf_t *conf);
+/*%<
+ * Return the search list stored in 'conf'.
+ *
+ * Requires:
+ *
+ *\li	'conf' is a valid resconf object.
+ */
+
+unsigned int
+irs_resconf_getndots(irs_resconf_t *conf);
+/*%<
+ * Return the 'ndots' value stored in 'conf'.
+ *
+ * Requires:
+ *
+ *\li	'conf' is a valid resconf object.
+ */
+
+ISC_LANG_ENDDECLS
+
+#endif /* IRS_RESCONF_H */
diff --git a/lib/irs/include/irs/types.h b/lib/irs/include/irs/types.h
new file mode 100644
index 0000000..54153f8
--- /dev/null
+++ b/lib/irs/include/irs/types.h
@@ -0,0 +1,26 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ *
+ * 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 https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+#ifndef IRS_TYPES_H
+#define IRS_TYPES_H 1
+
+/* Core Types.  Alphabetized by defined type. */
+
+/*%< per-thread IRS context */
+typedef struct irs_context irs_context_t;
+/*%< resolv.conf configuration information */
+typedef struct irs_resconf irs_resconf_t;
+/*%< advanced DNS-related configuration information */
+typedef struct irs_dnsconf irs_dnsconf_t;
+
+#endif /* IRS_TYPES_H */
diff --git a/lib/irs/include/irs/version.h b/lib/irs/include/irs/version.h
new file mode 100644
index 0000000..75ba926
--- /dev/null
+++ b/lib/irs/include/irs/version.h
@@ -0,0 +1,18 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ *
+ * 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 https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+/*! \file */
+
+#include <irs/platform.h>
+
+LIBIRS_EXTERNAL_DATA extern const char irs_version[];
diff --git a/lib/irs/resconf.c b/lib/irs/resconf.c
new file mode 100644
index 0000000..f3b7be5
--- /dev/null
+++ b/lib/irs/resconf.c
@@ -0,0 +1,689 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ *
+ * 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 https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+/*! \file resconf.c */
+
+/**
+ * Module for parsing resolv.conf files (largely derived from lwconfig.c).
+ *
+ *    irs_resconf_load() opens the file filename and parses it to initialize
+ *    the configuration structure.
+ *
+ * \section lwconfig_return Return Values
+ *
+ *    irs_resconf_load() returns #IRS_R_SUCCESS if it successfully read and
+ *    parsed filename. It returns a non-0 error code if filename could not be
+ *    opened or contained incorrect resolver statements.
+ *
+ * \section lwconfig_see See Also
+ *
+ *    stdio(3), \link resolver resolver \endlink
+ *
+ * \section files Files
+ *
+ *    /etc/resolv.conf
+ */
+
+#ifndef WIN32
+#include <netdb.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+#endif /* ifndef WIN32 */
+
+#include <ctype.h>
+#include <errno.h>
+#include <inttypes.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <isc/magic.h>
+#include <isc/mem.h>
+#include <isc/netaddr.h>
+#include <isc/sockaddr.h>
+#include <isc/util.h>
+
+#include <irs/netdb.h>
+#include <irs/resconf.h>
+
+#define IRS_RESCONF_MAGIC    ISC_MAGIC('R', 'E', 'S', 'c')
+#define IRS_RESCONF_VALID(c) ISC_MAGIC_VALID(c, IRS_RESCONF_MAGIC)
+
+/*!
+ * protocol constants
+ */
+
+#if !defined(NS_INADDRSZ)
+#define NS_INADDRSZ 4
+#endif /* if !defined(NS_INADDRSZ) */
+
+#if !defined(NS_IN6ADDRSZ)
+#define NS_IN6ADDRSZ 16
+#endif /* if !defined(NS_IN6ADDRSZ) */
+
+/*!
+ * resolv.conf parameters
+ */
+
+#define RESCONFMAXNAMESERVERS 3U   /*%< max 3 "nameserver" entries */
+#define RESCONFMAXSEARCH      8U   /*%< max 8 domains in "search" entry */
+#define RESCONFMAXLINELEN     256U /*%< max size of a line */
+#define RESCONFMAXSORTLIST    10U  /*%< max 10 */
+
+/*!
+ * configuration data structure
+ */
+
+struct irs_resconf {
+	/*
+	 * The configuration data is a thread-specific object, and does not
+	 * need to be locked.
+	 */
+	unsigned int magic;
+	isc_mem_t *mctx;
+
+	isc_sockaddrlist_t nameservers;
+	unsigned int numns; /*%< number of configured servers
+			     * */
+
+	char *domainname;
+	char *search[RESCONFMAXSEARCH];
+	uint8_t searchnxt; /*%< index for next free slot
+			    * */
+
+	irs_resconf_searchlist_t searchlist;
+
+	struct {
+		isc_netaddr_t addr;
+		/*% mask has a non-zero 'family' if set */
+		isc_netaddr_t mask;
+	} sortlist[RESCONFMAXSORTLIST];
+	uint8_t sortlistnxt;
+
+	/*%< non-zero if 'options debug' set */
+	uint8_t resdebug;
+	/*%< set to n in 'options ndots:n' */
+	uint8_t ndots;
+};
+
+static isc_result_t
+resconf_parsenameserver(irs_resconf_t *conf, FILE *fp);
+static isc_result_t
+resconf_parsedomain(irs_resconf_t *conf, FILE *fp);
+static isc_result_t
+resconf_parsesearch(irs_resconf_t *conf, FILE *fp);
+static isc_result_t
+resconf_parsesortlist(irs_resconf_t *conf, FILE *fp);
+static isc_result_t
+resconf_parseoption(irs_resconf_t *ctx, FILE *fp);
+
+#if HAVE_GET_WIN32_NAMESERVERS
+static isc_result_t
+get_win32_nameservers(irs_resconf_t *conf);
+#endif /* if HAVE_GET_WIN32_NAMESERVERS */
+
+/*!
+ * Eat characters from FP until EOL or EOF. Returns EOF or '\n'
+ */
+static int
+eatline(FILE *fp) {
+	int ch;
+
+	ch = fgetc(fp);
+	while (ch != '\n' && ch != EOF) {
+		ch = fgetc(fp);
+	}
+
+	return (ch);
+}
+
+/*!
+ * Eats white space up to next newline or non-whitespace character (of
+ * EOF). Returns the last character read. Comments are considered white
+ * space.
+ */
+static int
+eatwhite(FILE *fp) {
+	int ch;
+
+	ch = fgetc(fp);
+	while (ch != '\n' && ch != EOF && isspace((unsigned char)ch)) {
+		ch = fgetc(fp);
+	}
+
+	if (ch == ';' || ch == '#') {
+		ch = eatline(fp);
+	}
+
+	return (ch);
+}
+
+/*!
+ * Skip over any leading whitespace and then read in the next sequence of
+ * non-whitespace characters. In this context newline is not considered
+ * whitespace. Returns EOF on end-of-file, or the character
+ * that caused the reading to stop.
+ */
+static int
+getword(FILE *fp, char *buffer, size_t size) {
+	int ch;
+	char *p;
+
+	REQUIRE(buffer != NULL);
+	REQUIRE(size > 0U);
+
+	p = buffer;
+	*p = '\0';
+
+	ch = eatwhite(fp);
+
+	if (ch == EOF) {
+		return (EOF);
+	}
+
+	do {
+		*p = '\0';
+
+		if (ch == EOF || isspace((unsigned char)ch)) {
+			break;
+		} else if ((size_t)(p - buffer) == size - 1) {
+			return (EOF); /* Not enough space. */
+		}
+
+		*p++ = (char)ch;
+		ch = fgetc(fp);
+	} while (1);
+
+	return (ch);
+}
+
+static isc_result_t
+add_server(isc_mem_t *mctx, const char *address_str,
+	   isc_sockaddrlist_t *nameservers) {
+	int error;
+	isc_sockaddr_t *address = NULL;
+	struct addrinfo hints, *res;
+	isc_result_t result = ISC_R_SUCCESS;
+
+	res = NULL;
+	memset(&hints, 0, sizeof(hints));
+	hints.ai_family = AF_UNSPEC;
+	hints.ai_socktype = SOCK_DGRAM;
+	hints.ai_protocol = IPPROTO_UDP;
+	hints.ai_flags = AI_NUMERICHOST;
+	error = getaddrinfo(address_str, "53", &hints, &res);
+	if (error != 0) {
+		return (ISC_R_BADADDRESSFORM);
+	}
+
+	/* XXX: special case: treat all-0 IPv4 address as loopback */
+	if (res->ai_family == AF_INET) {
+		struct in_addr *v4;
+		unsigned char zeroaddress[] = { 0, 0, 0, 0 };
+		unsigned char loopaddress[] = { 127, 0, 0, 1 };
+
+		v4 = &((struct sockaddr_in *)res->ai_addr)->sin_addr;
+		if (memcmp(v4, zeroaddress, 4) == 0) {
+			memmove(v4, loopaddress, 4);
+		}
+	}
+
+	address = isc_mem_get(mctx, sizeof(*address));
+	if (res->ai_addrlen > sizeof(address->type)) {
+		isc_mem_put(mctx, address, sizeof(*address));
+		result = ISC_R_RANGE;
+		goto cleanup;
+	}
+	address->length = (unsigned int)res->ai_addrlen;
+	memmove(&address->type.ss, res->ai_addr, res->ai_addrlen);
+	ISC_LINK_INIT(address, link);
+	ISC_LIST_APPEND(*nameservers, address, link);
+
+cleanup:
+	freeaddrinfo(res);
+
+	return (result);
+}
+
+static isc_result_t
+create_addr(const char *buffer, isc_netaddr_t *addr, int convert_zero) {
+	struct in_addr v4;
+	struct in6_addr v6;
+
+	if (inet_pton(AF_INET, buffer, &v4) == 1) {
+		if (convert_zero) {
+			unsigned char zeroaddress[] = { 0, 0, 0, 0 };
+			unsigned char loopaddress[] = { 127, 0, 0, 1 };
+			if (memcmp(&v4, zeroaddress, 4) == 0) {
+				memmove(&v4, loopaddress, 4);
+			}
+		}
+		addr->family = AF_INET;
+		memmove(&addr->type.in, &v4, NS_INADDRSZ);
+		addr->zone = 0;
+	} else if (inet_pton(AF_INET6, buffer, &v6) == 1) {
+		addr->family = AF_INET6;
+		memmove(&addr->type.in6, &v6, NS_IN6ADDRSZ);
+		addr->zone = 0;
+	} else {
+		return (ISC_R_BADADDRESSFORM); /* Unrecognised format. */
+	}
+
+	return (ISC_R_SUCCESS);
+}
+
+static isc_result_t
+resconf_parsenameserver(irs_resconf_t *conf, FILE *fp) {
+	char word[RESCONFMAXLINELEN];
+	int cp;
+	isc_result_t result;
+
+	cp = getword(fp, word, sizeof(word));
+	if (strlen(word) == 0U) {
+		return (ISC_R_UNEXPECTEDEND); /* Nothing on line. */
+	} else if (cp == ' ' || cp == '\t') {
+		cp = eatwhite(fp);
+	}
+
+	if (cp != EOF && cp != '\n') {
+		return (ISC_R_UNEXPECTEDTOKEN); /* Extra junk on line. */
+	}
+
+	if (conf->numns == RESCONFMAXNAMESERVERS) {
+		return (ISC_R_SUCCESS);
+	}
+
+	result = add_server(conf->mctx, word, &conf->nameservers);
+	if (result != ISC_R_SUCCESS) {
+		return (result);
+	}
+	conf->numns++;
+
+	return (ISC_R_SUCCESS);
+}
+
+static isc_result_t
+resconf_parsedomain(irs_resconf_t *conf, FILE *fp) {
+	char word[RESCONFMAXLINELEN];
+	int res;
+	unsigned int i;
+
+	res = getword(fp, word, sizeof(word));
+	if (strlen(word) == 0U) {
+		return (ISC_R_UNEXPECTEDEND); /* Nothing else on line. */
+	} else if (res == ' ' || res == '\t') {
+		res = eatwhite(fp);
+	}
+
+	if (res != EOF && res != '\n') {
+		return (ISC_R_UNEXPECTEDTOKEN); /* Extra junk on line. */
+	}
+
+	if (conf->domainname != NULL) {
+		isc_mem_free(conf->mctx, conf->domainname);
+	}
+
+	/*
+	 * Search and domain are mutually exclusive.
+	 */
+	for (i = 0; i < RESCONFMAXSEARCH; i++) {
+		if (conf->search[i] != NULL) {
+			isc_mem_free(conf->mctx, conf->search[i]);
+			conf->search[i] = NULL;
+		}
+	}
+	conf->searchnxt = 0;
+
+	conf->domainname = isc_mem_strdup(conf->mctx, word);
+
+	return (ISC_R_SUCCESS);
+}
+
+static isc_result_t
+resconf_parsesearch(irs_resconf_t *conf, FILE *fp) {
+	int delim;
+	unsigned int idx;
+	char word[RESCONFMAXLINELEN];
+
+	if (conf->domainname != NULL) {
+		/*
+		 * Search and domain are mutually exclusive.
+		 */
+		isc_mem_free(conf->mctx, conf->domainname);
+		conf->domainname = NULL;
+	}
+
+	/*
+	 * Remove any previous search definitions.
+	 */
+	for (idx = 0; idx < RESCONFMAXSEARCH; idx++) {
+		if (conf->search[idx] != NULL) {
+			isc_mem_free(conf->mctx, conf->search[idx]);
+			conf->search[idx] = NULL;
+		}
+	}
+	conf->searchnxt = 0;
+
+	delim = getword(fp, word, sizeof(word));
+	if (strlen(word) == 0U) {
+		return (ISC_R_UNEXPECTEDEND); /* Nothing else on line. */
+	}
+
+	idx = 0;
+	while (strlen(word) > 0U) {
+		if (conf->searchnxt == RESCONFMAXSEARCH) {
+			goto ignore; /* Too many domains. */
+		}
+
+		INSIST(idx < sizeof(conf->search) / sizeof(conf->search[0]));
+		conf->search[idx] = isc_mem_strdup(conf->mctx, word);
+		idx++;
+		conf->searchnxt++;
+
+	ignore:
+		if (delim == EOF || delim == '\n') {
+			break;
+		} else {
+			delim = getword(fp, word, sizeof(word));
+		}
+	}
+
+	return (ISC_R_SUCCESS);
+}
+
+static isc_result_t
+resconf_parsesortlist(irs_resconf_t *conf, FILE *fp) {
+	int delim, res;
+	unsigned int idx;
+	char word[RESCONFMAXLINELEN];
+	char *p;
+
+	delim = getword(fp, word, sizeof(word));
+	if (strlen(word) == 0U) {
+		return (ISC_R_UNEXPECTEDEND); /* Empty line after keyword. */
+	}
+
+	while (strlen(word) > 0U) {
+		if (conf->sortlistnxt == RESCONFMAXSORTLIST) {
+			return (ISC_R_QUOTA); /* Too many values. */
+		}
+
+		p = strchr(word, '/');
+		if (p != NULL) {
+			*p++ = '\0';
+		}
+
+		idx = conf->sortlistnxt;
+		INSIST(idx <
+		       sizeof(conf->sortlist) / sizeof(conf->sortlist[0]));
+		res = create_addr(word, &conf->sortlist[idx].addr, 1);
+		if (res != ISC_R_SUCCESS) {
+			return (res);
+		}
+
+		if (p != NULL) {
+			res = create_addr(p, &conf->sortlist[idx].mask, 0);
+			if (res != ISC_R_SUCCESS) {
+				return (res);
+			}
+		} else {
+			/*
+			 * Make up a mask. (XXX: is this correct?)
+			 */
+			conf->sortlist[idx].mask = conf->sortlist[idx].addr;
+			memset(&conf->sortlist[idx].mask.type, 0xff,
+			       sizeof(conf->sortlist[idx].mask.type));
+		}
+
+		conf->sortlistnxt++;
+
+		if (delim == EOF || delim == '\n') {
+			break;
+		} else {
+			delim = getword(fp, word, sizeof(word));
+		}
+	}
+
+	return (ISC_R_SUCCESS);
+}
+
+static isc_result_t
+resconf_parseoption(irs_resconf_t *conf, FILE *fp) {
+	int delim;
+	long ndots;
+	char *p;
+	char word[RESCONFMAXLINELEN];
+
+	delim = getword(fp, word, sizeof(word));
+	if (strlen(word) == 0U) {
+		return (ISC_R_UNEXPECTEDEND); /* Empty line after keyword. */
+	}
+
+	while (strlen(word) > 0U) {
+		if (strcmp("debug", word) == 0) {
+			conf->resdebug = 1;
+		} else if (strncmp("ndots:", word, 6) == 0) {
+			ndots = strtol(word + 6, &p, 10);
+			if (*p != '\0') { /* Bad string. */
+				return (ISC_R_UNEXPECTEDTOKEN);
+			}
+			if (ndots < 0 || ndots > 0xff) { /* Out of range. */
+				return (ISC_R_RANGE);
+			}
+			conf->ndots = (uint8_t)ndots;
+		}
+
+		if (delim == EOF || delim == '\n') {
+			break;
+		} else {
+			delim = getword(fp, word, sizeof(word));
+		}
+	}
+
+	return (ISC_R_SUCCESS);
+}
+
+static isc_result_t
+add_search(irs_resconf_t *conf, char *domain) {
+	irs_resconf_search_t *entry;
+
+	entry = isc_mem_get(conf->mctx, sizeof(*entry));
+
+	entry->domain = domain;
+	ISC_LINK_INIT(entry, link);
+	ISC_LIST_APPEND(conf->searchlist, entry, link);
+
+	return (ISC_R_SUCCESS);
+}
+
+/*% parses a file and fills in the data structure. */
+isc_result_t
+irs_resconf_load(isc_mem_t *mctx, const char *filename, irs_resconf_t **confp) {
+	FILE *fp = NULL;
+	char word[256];
+	isc_result_t rval, ret = ISC_R_SUCCESS;
+	irs_resconf_t *conf;
+	unsigned int i;
+	int stopchar;
+
+	REQUIRE(mctx != NULL);
+	REQUIRE(filename != NULL);
+	REQUIRE(strlen(filename) > 0U);
+	REQUIRE(confp != NULL && *confp == NULL);
+
+	conf = isc_mem_get(mctx, sizeof(*conf));
+
+	conf->mctx = mctx;
+	ISC_LIST_INIT(conf->nameservers);
+	ISC_LIST_INIT(conf->searchlist);
+	conf->numns = 0;
+	conf->domainname = NULL;
+	conf->searchnxt = 0;
+	conf->sortlistnxt = 0;
+	conf->resdebug = 0;
+	conf->ndots = 1;
+	for (i = 0; i < RESCONFMAXSEARCH; i++) {
+		conf->search[i] = NULL;
+	}
+
+	errno = 0;
+	if ((fp = fopen(filename, "r")) != NULL) {
+		do {
+			stopchar = getword(fp, word, sizeof(word));
+			if (stopchar == EOF) {
+				rval = ISC_R_SUCCESS;
+				POST(rval);
+				break;
+			}
+
+			if (strlen(word) == 0U) {
+				rval = ISC_R_SUCCESS;
+			} else if (strcmp(word, "nameserver") == 0) {
+				rval = resconf_parsenameserver(conf, fp);
+			} else if (strcmp(word, "domain") == 0) {
+				rval = resconf_parsedomain(conf, fp);
+			} else if (strcmp(word, "search") == 0) {
+				rval = resconf_parsesearch(conf, fp);
+			} else if (strcmp(word, "sortlist") == 0) {
+				rval = resconf_parsesortlist(conf, fp);
+			} else if (strcmp(word, "options") == 0) {
+				rval = resconf_parseoption(conf, fp);
+			} else {
+				/* unrecognised word. Ignore entire line */
+				rval = ISC_R_SUCCESS;
+				stopchar = eatline(fp);
+				if (stopchar == EOF) {
+					break;
+				}
+			}
+			if (ret == ISC_R_SUCCESS && rval != ISC_R_SUCCESS) {
+				ret = rval;
+			}
+		} while (1);
+
+		fclose(fp);
+	} else {
+		switch (errno) {
+		case ENOENT:
+			break;
+		default:
+			isc_mem_put(mctx, conf, sizeof(*conf));
+			return (ISC_R_INVALIDFILE);
+		}
+	}
+
+	if (ret != ISC_R_SUCCESS) {
+		goto error;
+	}
+
+	/*
+	 * Construct unified search list from domain or configured
+	 * search list
+	 */
+	if (conf->domainname != NULL) {
+		ret = add_search(conf, conf->domainname);
+	} else if (conf->searchnxt > 0) {
+		for (i = 0; i < conf->searchnxt; i++) {
+			ret = add_search(conf, conf->search[i]);
+			if (ret != ISC_R_SUCCESS) {
+				break;
+			}
+		}
+	}
+
+#if HAVE_GET_WIN32_NAMESERVERS
+	ret = get_win32_nameservers(conf);
+	if (ret != ISC_R_SUCCESS) {
+		goto error;
+	}
+#endif /* if HAVE_GET_WIN32_NAMESERVERS */
+
+	/* If we don't find a nameserver fall back to localhost */
+	if (conf->numns == 0U) {
+		INSIST(ISC_LIST_EMPTY(conf->nameservers));
+
+		/* XXX: should we catch errors? */
+		(void)add_server(conf->mctx, "::1", &conf->nameservers);
+		(void)add_server(conf->mctx, "127.0.0.1", &conf->nameservers);
+	}
+
+error:
+	conf->magic = IRS_RESCONF_MAGIC;
+
+	if (ret != ISC_R_SUCCESS) {
+		irs_resconf_destroy(&conf);
+	} else {
+		if (fp == NULL) {
+			ret = ISC_R_FILENOTFOUND;
+		}
+		*confp = conf;
+	}
+
+	return (ret);
+}
+
+void
+irs_resconf_destroy(irs_resconf_t **confp) {
+	irs_resconf_t *conf;
+	isc_sockaddr_t *address;
+	irs_resconf_search_t *searchentry;
+	unsigned int i;
+
+	REQUIRE(confp != NULL);
+	conf = *confp;
+	*confp = NULL;
+	REQUIRE(IRS_RESCONF_VALID(conf));
+
+	while ((searchentry = ISC_LIST_HEAD(conf->searchlist)) != NULL) {
+		ISC_LIST_UNLINK(conf->searchlist, searchentry, link);
+		isc_mem_put(conf->mctx, searchentry, sizeof(*searchentry));
+	}
+
+	while ((address = ISC_LIST_HEAD(conf->nameservers)) != NULL) {
+		ISC_LIST_UNLINK(conf->nameservers, address, link);
+		isc_mem_put(conf->mctx, address, sizeof(*address));
+	}
+
+	if (conf->domainname != NULL) {
+		isc_mem_free(conf->mctx, conf->domainname);
+	}
+
+	for (i = 0; i < RESCONFMAXSEARCH; i++) {
+		if (conf->search[i] != NULL) {
+			isc_mem_free(conf->mctx, conf->search[i]);
+		}
+	}
+
+	isc_mem_put(conf->mctx, conf, sizeof(*conf));
+}
+
+isc_sockaddrlist_t *
+irs_resconf_getnameservers(irs_resconf_t *conf) {
+	REQUIRE(IRS_RESCONF_VALID(conf));
+
+	return (&conf->nameservers);
+}
+
+irs_resconf_searchlist_t *
+irs_resconf_getsearchlist(irs_resconf_t *conf) {
+	REQUIRE(IRS_RESCONF_VALID(conf));
+
+	return (&conf->searchlist);
+}
+
+unsigned int
+irs_resconf_getndots(irs_resconf_t *conf) {
+	REQUIRE(IRS_RESCONF_VALID(conf));
+
+	return ((unsigned int)conf->ndots);
+}
diff --git a/lib/irs/tests/Kyuafile b/lib/irs/tests/Kyuafile
new file mode 100644
index 0000000..a203172
--- /dev/null
+++ b/lib/irs/tests/Kyuafile
@@ -0,0 +1,15 @@
+-- Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+--
+-- SPDX-License-Identifier: MPL-2.0
+--
+-- 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 https://mozilla.org/MPL/2.0/.
+--
+-- See the COPYRIGHT file distributed with this work for additional
+-- information regarding copyright ownership.
+
+syntax(2)
+test_suite('bind9')
+
+tap_test_program{name='resconf_test'}
diff --git a/lib/irs/tests/Makefile.in b/lib/irs/tests/Makefile.in
new file mode 100644
index 0000000..327d31d
--- /dev/null
+++ b/lib/irs/tests/Makefile.in
@@ -0,0 +1,51 @@
+# Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+#
+# SPDX-License-Identifier: MPL-2.0
+#
+# 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 https://mozilla.org/MPL/2.0/.
+#
+# See the COPYRIGHT file distributed with this work for additional
+# information regarding copyright ownership.
+
+srcdir =	@srcdir@
+VPATH =		@srcdir@
+top_srcdir =	@top_srcdir@
+
+VERSION=@BIND9_VERSION@
+
+@BIND9_MAKE_INCLUDES@
+
+CINCLUDES =	-I. -Iinclude -I../include ${ISC_INCLUDES} ${IRS_INCLUDES} @CMOCKA_CFLAGS@
+CDEFINES =	-DTESTS="\"${top_builddir}/lib/irs/tests/\""
+
+CFGLIBS =	../../isccfg/libisccfg.@A@
+CFGDEPLIBS =	../../isccfg/libisccfg.@A@
+DNSLIBS =	../../dns/libdns.@A@ @NO_LIBTOOL_DNSLIBS@
+DNSDEPLIBS =	../../dns/libdns.@A@
+ISCLIBS =	../../isc/libisc.@A@ @NO_LIBTOOL_ISCLIBS@
+ISCDEPLIBS =	../../isc/libisc.@A@
+IRSLIBS =	../libirs.@A@
+IRSDEPLIBS =	../libirs.@A@
+
+LIBS =		${IRSLIBS} ${CFGLIBS} ${DNSLIBS} ${ISCLIBS} @LIBS@ @CMOCKA_LIBS@
+
+OBJS =
+SRCS =		resconf_test.c
+
+SUBDIRS =
+TARGETS =	resconf_test@EXEEXT@
+
+@BIND9_MAKE_RULES@
+
+resconf_test@EXEEXT@: resconf_test.@O@ ${CFGDEPLIBS} ${DNSDEPLIBS} ${IRSDEPLIBS} ${ISCDEPLIBS}
+	${LIBTOOL_MODE_LINK} ${PURIFY} ${CC} ${CFLAGS} \
+		${LDFLAGS} -o $@ resconf_test.@O@ ${LIBS}
+
+unit::
+	sh ${top_builddir}/unit/unittest.sh
+
+clean distclean::
+	rm -f ${TARGETS}
+	rm -f atf.out
diff --git a/lib/irs/tests/resconf_test.c b/lib/irs/tests/resconf_test.c
new file mode 100644
index 0000000..6951758
--- /dev/null
+++ b/lib/irs/tests/resconf_test.c
@@ -0,0 +1,142 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ *
+ * 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 https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+#if HAVE_CMOCKA
+
+#include <sched.h> /* IWYU pragma: keep */
+#include <setjmp.h>
+#include <stdarg.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#define UNIT_TESTING
+#include <cmocka.h>
+
+#include <isc/mem.h>
+#include <isc/util.h>
+
+#include <irs/resconf.h>
+#include <irs/types.h>
+
+static isc_mem_t *mctx = NULL;
+
+static void
+setup_test() {
+	isc_mem_create(&mctx);
+
+	/*
+	 * the caller might run from another directory, but tests
+	 * that access test data files must first chdir to the proper
+	 * location.
+	 */
+	assert_return_code(chdir(TESTS), 0);
+}
+
+/* test irs_resconf_load() */
+static void
+irs_resconf_load_test(void **state) {
+	isc_result_t result;
+	irs_resconf_t *resconf = NULL;
+	unsigned int i;
+	struct {
+		const char *file;
+		isc_result_t loadres;
+		isc_result_t (*check)(irs_resconf_t *resconf);
+		isc_result_t checkres;
+	} tests[] = {
+		{ "testdata/domain.conf", ISC_R_SUCCESS, NULL, ISC_R_SUCCESS },
+		{ "testdata/nameserver-v4.conf", ISC_R_SUCCESS, NULL,
+		  ISC_R_SUCCESS },
+		{ "testdata/nameserver-v6.conf", ISC_R_SUCCESS, NULL,
+		  ISC_R_SUCCESS },
+		{ "testdata/nameserver-v6-scoped.conf", ISC_R_SUCCESS, NULL,
+		  ISC_R_SUCCESS },
+		{ "testdata/options-debug.conf", ISC_R_SUCCESS, NULL,
+		  ISC_R_SUCCESS },
+		{ "testdata/options-ndots.conf", ISC_R_SUCCESS, NULL,
+		  ISC_R_SUCCESS },
+		{ "testdata/options-timeout.conf", ISC_R_SUCCESS, NULL,
+		  ISC_R_SUCCESS },
+		{ "testdata/options-unknown.conf", ISC_R_SUCCESS, NULL,
+		  ISC_R_SUCCESS },
+		{ "testdata/options.conf", ISC_R_SUCCESS, NULL, ISC_R_SUCCESS },
+		{ "testdata/options-bad-ndots.conf", ISC_R_RANGE, NULL,
+		  ISC_R_SUCCESS },
+		{ "testdata/options-empty.conf", ISC_R_UNEXPECTEDEND, NULL,
+		  ISC_R_SUCCESS },
+		{ "testdata/port.conf", ISC_R_SUCCESS, NULL, ISC_R_SUCCESS },
+		{ "testdata/resolv.conf", ISC_R_SUCCESS, NULL, ISC_R_SUCCESS },
+		{ "testdata/search.conf", ISC_R_SUCCESS, NULL, ISC_R_SUCCESS },
+		{ "testdata/sortlist-v4.conf", ISC_R_SUCCESS, NULL,
+		  ISC_R_SUCCESS },
+		{ "testdata/timeout.conf", ISC_R_SUCCESS, NULL, ISC_R_SUCCESS },
+		{ "testdata/unknown.conf", ISC_R_SUCCESS, NULL, ISC_R_SUCCESS }
+	};
+
+	UNUSED(state);
+
+	setup_test();
+
+	for (i = 0; i < sizeof(tests) / sizeof(tests[1]); i++) {
+		result = irs_resconf_load(mctx, tests[i].file, &resconf);
+		if (result != tests[i].loadres) {
+			fail_msg("# unexpected result %s loading %s",
+				 isc_result_totext(result), tests[i].file);
+		}
+
+		if (result == ISC_R_SUCCESS && resconf == NULL) {
+			fail_msg("# NULL on success loading %s", tests[i].file);
+		} else if (result != ISC_R_SUCCESS && resconf != NULL) {
+			fail_msg("# non-NULL on failure loading %s",
+				 tests[i].file);
+		}
+
+		if (resconf != NULL && tests[i].check != NULL) {
+			result = (tests[i].check)(resconf);
+			if (result != tests[i].checkres) {
+				fail_msg("# unexpected result %s loading %s",
+					 isc_result_totext(result),
+					 tests[i].file);
+			}
+		}
+		if (resconf != NULL) {
+			irs_resconf_destroy(&resconf);
+		}
+	}
+
+	isc_mem_detach(&mctx);
+}
+
+int
+main(void) {
+	const struct CMUnitTest tests[] = {
+		cmocka_unit_test(irs_resconf_load_test),
+	};
+
+	return (cmocka_run_group_tests(tests, NULL, NULL));
+}
+
+#else /* HAVE_CMOCKA */
+
+#include <stdio.h>
+
+int
+main(void) {
+	printf("1..0 # Skipped: cmocka not available\n");
+	return (SKIPPED_TEST_EXIT_CODE);
+}
+
+#endif /* if HAVE_CMOCKA */
diff --git a/lib/irs/tests/testdata/domain.conf b/lib/irs/tests/testdata/domain.conf
new file mode 100644
index 0000000..ee43f5c
--- /dev/null
+++ b/lib/irs/tests/testdata/domain.conf
@@ -0,0 +1,12 @@
+# Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+#
+# SPDX-License-Identifier: MPL-2.0
+#
+# 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 https://mozilla.org/MPL/2.0/.
+#
+# See the COPYRIGHT file distributed with this work for additional
+# information regarding copyright ownership.
+
+domain example.com
diff --git a/lib/irs/tests/testdata/nameserver-v4.conf b/lib/irs/tests/testdata/nameserver-v4.conf
new file mode 100644
index 0000000..5054de0
--- /dev/null
+++ b/lib/irs/tests/testdata/nameserver-v4.conf
@@ -0,0 +1,12 @@
+# Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+#
+# SPDX-License-Identifier: MPL-2.0
+#
+# 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 https://mozilla.org/MPL/2.0/.
+#
+# See the COPYRIGHT file distributed with this work for additional
+# information regarding copyright ownership.
+
+nameserver 10.0.0.1
diff --git a/lib/irs/tests/testdata/nameserver-v6-scoped.conf b/lib/irs/tests/testdata/nameserver-v6-scoped.conf
new file mode 100644
index 0000000..d5bd97f
--- /dev/null
+++ b/lib/irs/tests/testdata/nameserver-v6-scoped.conf
@@ -0,0 +1,12 @@
+# Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+#
+# SPDX-License-Identifier: MPL-2.0
+#
+# 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 https://mozilla.org/MPL/2.0/.
+#
+# See the COPYRIGHT file distributed with this work for additional
+# information regarding copyright ownership.
+
+nameserver fe80::1%1
diff --git a/lib/irs/tests/testdata/nameserver-v6.conf b/lib/irs/tests/testdata/nameserver-v6.conf
new file mode 100644
index 0000000..b9ed093
--- /dev/null
+++ b/lib/irs/tests/testdata/nameserver-v6.conf
@@ -0,0 +1,12 @@
+# Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+#
+# SPDX-License-Identifier: MPL-2.0
+#
+# 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 https://mozilla.org/MPL/2.0/.
+#
+# See the COPYRIGHT file distributed with this work for additional
+# information regarding copyright ownership.
+
+nameserver 2001:DB8::1
diff --git a/lib/irs/tests/testdata/options-bad-ndots.conf b/lib/irs/tests/testdata/options-bad-ndots.conf
new file mode 100644
index 0000000..18d3f8b
--- /dev/null
+++ b/lib/irs/tests/testdata/options-bad-ndots.conf
@@ -0,0 +1,13 @@
+# Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+#
+# SPDX-License-Identifier: MPL-2.0
+#
+# 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 https://mozilla.org/MPL/2.0/.
+#
+# See the COPYRIGHT file distributed with this work for additional
+# information regarding copyright ownership.
+
+search example.com example.net
+options ndots:256
diff --git a/lib/irs/tests/testdata/options-debug.conf b/lib/irs/tests/testdata/options-debug.conf
new file mode 100644
index 0000000..04bcf2e
--- /dev/null
+++ b/lib/irs/tests/testdata/options-debug.conf
@@ -0,0 +1,12 @@
+# Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+#
+# SPDX-License-Identifier: MPL-2.0
+#
+# 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 https://mozilla.org/MPL/2.0/.
+#
+# See the COPYRIGHT file distributed with this work for additional
+# information regarding copyright ownership.
+
+options debug
diff --git a/lib/irs/tests/testdata/options-empty.conf b/lib/irs/tests/testdata/options-empty.conf
new file mode 100644
index 0000000..0b1dc9e
--- /dev/null
+++ b/lib/irs/tests/testdata/options-empty.conf
@@ -0,0 +1,13 @@
+# Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+#
+# SPDX-License-Identifier: MPL-2.0
+#
+# 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 https://mozilla.org/MPL/2.0/.
+#
+# See the COPYRIGHT file distributed with this work for additional
+# information regarding copyright ownership.
+
+domain example.com
+options
diff --git a/lib/irs/tests/testdata/options-ndots.conf b/lib/irs/tests/testdata/options-ndots.conf
new file mode 100644
index 0000000..5d18d26
--- /dev/null
+++ b/lib/irs/tests/testdata/options-ndots.conf
@@ -0,0 +1,12 @@
+# Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+#
+# SPDX-License-Identifier: MPL-2.0
+#
+# 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 https://mozilla.org/MPL/2.0/.
+#
+# See the COPYRIGHT file distributed with this work for additional
+# information regarding copyright ownership.
+
+option ndots:2
diff --git a/lib/irs/tests/testdata/options-timeout.conf b/lib/irs/tests/testdata/options-timeout.conf
new file mode 100644
index 0000000..96787c4
--- /dev/null
+++ b/lib/irs/tests/testdata/options-timeout.conf
@@ -0,0 +1,12 @@
+# Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+#
+# SPDX-License-Identifier: MPL-2.0
+#
+# 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 https://mozilla.org/MPL/2.0/.
+#
+# See the COPYRIGHT file distributed with this work for additional
+# information regarding copyright ownership.
+
+options timeout:1
diff --git a/lib/irs/tests/testdata/options-unknown.conf b/lib/irs/tests/testdata/options-unknown.conf
new file mode 100644
index 0000000..fdf82b4
--- /dev/null
+++ b/lib/irs/tests/testdata/options-unknown.conf
@@ -0,0 +1,12 @@
+# Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+#
+# SPDX-License-Identifier: MPL-2.0
+#
+# 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 https://mozilla.org/MPL/2.0/.
+#
+# See the COPYRIGHT file distributed with this work for additional
+# information regarding copyright ownership.
+
+options unknown
diff --git a/lib/irs/tests/testdata/options.conf b/lib/irs/tests/testdata/options.conf
new file mode 100644
index 0000000..7a8d5f3
--- /dev/null
+++ b/lib/irs/tests/testdata/options.conf
@@ -0,0 +1,12 @@
+# Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+#
+# SPDX-License-Identifier: MPL-2.0
+#
+# 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 https://mozilla.org/MPL/2.0/.
+#
+# See the COPYRIGHT file distributed with this work for additional
+# information regarding copyright ownership.
+
+options unknown debug timeout:1 ndots:2
diff --git a/lib/irs/tests/testdata/port.conf b/lib/irs/tests/testdata/port.conf
new file mode 100644
index 0000000..54e2094
--- /dev/null
+++ b/lib/irs/tests/testdata/port.conf
@@ -0,0 +1,12 @@
+# Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+#
+# SPDX-License-Identifier: MPL-2.0
+#
+# 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 https://mozilla.org/MPL/2.0/.
+#
+# See the COPYRIGHT file distributed with this work for additional
+# information regarding copyright ownership.
+
+port 5300
diff --git a/lib/irs/tests/testdata/resolv.conf b/lib/irs/tests/testdata/resolv.conf
new file mode 100644
index 0000000..3c14408
--- /dev/null
+++ b/lib/irs/tests/testdata/resolv.conf
@@ -0,0 +1,19 @@
+# Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+#
+# SPDX-License-Identifier: MPL-2.0
+#
+# 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 https://mozilla.org/MPL/2.0/.
+#
+# See the COPYRIGHT file distributed with this work for additional
+# information regarding copyright ownership.
+
+port 5300
+nameserver 10.0.0.1
+nameserver 2001:DB8::1
+search example.com example.net
+sortlist 130.155.160.0/255.255.240.0 130.155.0.0
+timeout 10
+unknown directive
+options unknown debug timeout:1 ndots:2
diff --git a/lib/irs/tests/testdata/search.conf b/lib/irs/tests/testdata/search.conf
new file mode 100644
index 0000000..f019ab9
--- /dev/null
+++ b/lib/irs/tests/testdata/search.conf
@@ -0,0 +1,12 @@
+# Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+#
+# SPDX-License-Identifier: MPL-2.0
+#
+# 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 https://mozilla.org/MPL/2.0/.
+#
+# See the COPYRIGHT file distributed with this work for additional
+# information regarding copyright ownership.
+
+search example.com example.net
diff --git a/lib/irs/tests/testdata/sortlist-v4.conf b/lib/irs/tests/testdata/sortlist-v4.conf
new file mode 100644
index 0000000..3f4d54a
--- /dev/null
+++ b/lib/irs/tests/testdata/sortlist-v4.conf
@@ -0,0 +1,12 @@
+# Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+#
+# SPDX-License-Identifier: MPL-2.0
+#
+# 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 https://mozilla.org/MPL/2.0/.
+#
+# See the COPYRIGHT file distributed with this work for additional
+# information regarding copyright ownership.
+
+sortlist 130.155.160.0/255.255.240.0 130.155.0.0
diff --git a/lib/irs/tests/testdata/timeout.conf b/lib/irs/tests/testdata/timeout.conf
new file mode 100644
index 0000000..2ccb92d
--- /dev/null
+++ b/lib/irs/tests/testdata/timeout.conf
@@ -0,0 +1,12 @@
+# Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+#
+# SPDX-License-Identifier: MPL-2.0
+#
+# 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 https://mozilla.org/MPL/2.0/.
+#
+# See the COPYRIGHT file distributed with this work for additional
+# information regarding copyright ownership.
+
+timeout 10
diff --git a/lib/irs/tests/testdata/unknown.conf b/lib/irs/tests/testdata/unknown.conf
new file mode 100644
index 0000000..0eafb76
--- /dev/null
+++ b/lib/irs/tests/testdata/unknown.conf
@@ -0,0 +1,12 @@
+# Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+#
+# SPDX-License-Identifier: MPL-2.0
+#
+# 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 https://mozilla.org/MPL/2.0/.
+#
+# See the COPYRIGHT file distributed with this work for additional
+# information regarding copyright ownership.
+
+unknown directive
diff --git a/lib/irs/version.c b/lib/irs/version.c
new file mode 100644
index 0000000..b0b4fd9
--- /dev/null
+++ b/lib/irs/version.c
@@ -0,0 +1,18 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ *
+ * 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 https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+/*! \file */
+
+#include <irs/version.h>
+
+const char irs_version[] = VERSION;
diff --git a/lib/irs/win32/DLLMain.c b/lib/irs/win32/DLLMain.c
new file mode 100644
index 0000000..62c6e53
--- /dev/null
+++ b/lib/irs/win32/DLLMain.c
@@ -0,0 +1,49 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ *
+ * 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 https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+#include <signal.h>
+#include <windows.h>
+
+/*
+ * Called when we enter the DLL
+ */
+__declspec(dllexport) BOOL WINAPI
+	DllMain(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved) {
+	switch (fdwReason) {
+	/*
+	 * The DLL is loading due to process
+	 * initialization or a call to LoadLibrary.
+	 */
+	case DLL_PROCESS_ATTACH:
+		break;
+
+	/* The attached process creates a new thread.  */
+	case DLL_THREAD_ATTACH:
+		break;
+
+	/* The thread of the attached process terminates. */
+	case DLL_THREAD_DETACH:
+		break;
+
+	/*
+	 * The DLL is unloading from a process due to
+	 * process termination or a call to FreeLibrary.
+	 */
+	case DLL_PROCESS_DETACH:
+		break;
+
+	default:
+		break;
+	}
+	return (TRUE);
+}
diff --git a/lib/irs/win32/Makefile.in b/lib/irs/win32/Makefile.in
new file mode 100644
index 0000000..5641e1a
--- /dev/null
+++ b/lib/irs/win32/Makefile.in
@@ -0,0 +1,19 @@
+# Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+#
+# SPDX-License-Identifier: MPL-2.0
+#
+# 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 https://mozilla.org/MPL/2.0/.
+#
+# See the COPYRIGHT file distributed with this work for additional
+# information regarding copyright ownership.
+
+srcdir =	@srcdir@
+VPATH =		@srcdir@
+top_srcdir =	@top_srcdir@
+
+SUBDIRS =	include
+TARGETS =
+
+@BIND9_MAKE_RULES@
diff --git a/lib/irs/win32/include/.clang-format b/lib/irs/win32/include/.clang-format
new file mode 120000
index 0000000..e919bba
--- /dev/null
+++ b/lib/irs/win32/include/.clang-format
@@ -0,0 +1 @@
+../../../../.clang-format.headers
\ No newline at end of file
diff --git a/lib/irs/win32/include/Makefile.in b/lib/irs/win32/include/Makefile.in
new file mode 100644
index 0000000..53a5348
--- /dev/null
+++ b/lib/irs/win32/include/Makefile.in
@@ -0,0 +1,19 @@
+# Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+#
+# SPDX-License-Identifier: MPL-2.0
+#
+# 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 https://mozilla.org/MPL/2.0/.
+#
+# See the COPYRIGHT file distributed with this work for additional
+# information regarding copyright ownership.
+
+srcdir =	@srcdir@
+VPATH =		@srcdir@
+top_srcdir =	@top_srcdir@
+
+SUBDIRS =	irs
+TARGETS =
+
+@BIND9_MAKE_RULES@
diff --git a/lib/irs/win32/include/irs/Makefile.in b/lib/irs/win32/include/irs/Makefile.in
new file mode 100644
index 0000000..6d87432
--- /dev/null
+++ b/lib/irs/win32/include/irs/Makefile.in
@@ -0,0 +1,28 @@
+# Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+#
+# SPDX-License-Identifier: MPL-2.0
+#
+# 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 https://mozilla.org/MPL/2.0/.
+#
+# See the COPYRIGHT file distributed with this work for additional
+# information regarding copyright ownership.
+
+srcdir =	@srcdir@
+VPATH =		@srcdir@
+top_srcdir =	@top_srcdir@
+
+HEADERS =
+SUBDIRS =
+TARGETS =
+
+@BIND9_MAKE_RULES@
+
+installdirs:
+	$(SHELL) ${top_srcdir}/mkinstalldirs ${DESTDIR}${includedir}/irs
+
+install:: installdirs
+	for i in ${HEADERS}; do \
+		${INSTALL_DATA} ${srcdir}/$$i ${DESTDIR}${includedir}/irs || exit 1; \
+	done
diff --git a/lib/irs/win32/include/irs/netdb.h b/lib/irs/win32/include/irs/netdb.h
new file mode 100644
index 0000000..3e3e5d3
--- /dev/null
+++ b/lib/irs/win32/include/irs/netdb.h
@@ -0,0 +1,207 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ *
+ * 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 https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+/*! \file */
+
+#ifndef IRS_NETDB_H
+#define IRS_NETDB_H 1
+
+#include <stddef.h> /* Required on FreeBSD (and  others?) for size_t. */
+
+/*
+ * Define if <netdb.h> does not declare struct addrinfo.
+ */
+#undef ISC_IRS_NEEDADDRINFO
+
+#ifdef ISC_IRS_NEEDADDRINFO
+struct addrinfo {
+	int ai_flags;		       /* AI_PASSIVE, AI_CANONNAME */
+	int ai_family;		       /* PF_xxx */
+	int ai_socktype;	       /* SOCK_xxx */
+	int ai_protocol;	       /* 0 or IPPROTO_xxx for IPv4 and
+					* IPv6 */
+	size_t		 ai_addrlen;   /* Length of ai_addr */
+	char		*ai_canonname; /* Canonical name for hostname */
+	struct sockaddr *ai_addr;      /* Binary address */
+	struct addrinfo *ai_next;      /* Next structure in linked list */
+};
+#endif /* ifdef ISC_IRS_NEEDADDRINFO */
+
+/*
+ * Undefine all #defines we are interested in as <netdb.h> may or may not have
+ * defined them.
+ */
+
+/*
+ * Error return codes from gethostbyname() and gethostbyaddr()
+ * (left in extern int h_errno).
+ */
+
+#undef NETDB_INTERNAL
+#undef NETDB_SUCCESS
+#undef HOST_NOT_FOUND
+#undef TRY_AGAIN
+#undef NO_RECOVERY
+#undef NO_DATA
+#undef NO_ADDRESS
+
+#define NETDB_INTERNAL -1 /* see errno */
+#define NETDB_SUCCESS  0  /* no problem */
+#define HOST_NOT_FOUND 1  /* Authoritative Answer Host not found */
+#define TRY_AGAIN      2  /* Non-Authoritive Host not found, or SERVERFAIL */
+#define NO_RECOVERY    3  /* Non recoverable errors, FORMERR, REFUSED, NOTIMP */
+#define NO_DATA	       4  /* Valid name, no data record of requested type */
+#define NO_ADDRESS     NO_DATA /* no address, look for MX record */
+
+/*
+ * Error return codes from getaddrinfo().  EAI_INSECUREDATA is our own extension
+ * and it's very unlikely to be already defined, but undef it just in case; it
+ * at least doesn't do any harm.
+ */
+
+#undef EAI_ADDRFAMILY
+#undef EAI_AGAIN
+#undef EAI_BADFLAGS
+#undef EAI_FAIL
+#undef EAI_FAMILY
+#undef EAI_MEMORY
+#undef EAI_NODATA
+#undef EAI_NONAME
+#undef EAI_SERVICE
+#undef EAI_SOCKTYPE
+#undef EAI_SYSTEM
+#undef EAI_BADHINTS
+#undef EAI_PROTOCOL
+#undef EAI_OVERFLOW
+#undef EAI_INSECUREDATA
+#undef EAI_MAX
+
+#define EAI_ADDRFAMILY	 1  /* address family for hostname not supported */
+#define EAI_AGAIN	 2  /* temporary failure in name resolution */
+#define EAI_BADFLAGS	 3  /* invalid value for ai_flags */
+#define EAI_FAIL	 4  /* non-recoverable failure in name resolution */
+#define EAI_FAMILY	 5  /* ai_family not supported */
+#define EAI_MEMORY	 6  /* memory allocation failure */
+#define EAI_NODATA	 7  /* no address associated with hostname */
+#define EAI_NONAME	 8  /* hostname nor servname provided, or not known */
+#define EAI_SERVICE	 9  /* servname not supported for ai_socktype */
+#define EAI_SOCKTYPE	 10 /* ai_socktype not supported */
+#define EAI_SYSTEM	 11 /* system error returned in errno */
+#define EAI_BADHINTS	 12
+#define EAI_PROTOCOL	 13
+#define EAI_OVERFLOW	 14
+#define EAI_INSECUREDATA 15
+#define EAI_MAX		 16
+
+/*
+ * Flag values for getaddrinfo()
+ */
+#undef AI_PASSIVE
+#undef AI_CANONNAME
+#undef AI_NUMERICHOST
+
+#define AI_PASSIVE     0x00000001
+#define AI_CANONNAME   0x00000002
+#define AI_NUMERICHOST 0x00000004
+
+/*
+ * Flag values for getipnodebyname()
+ */
+#undef AI_V4MAPPED
+#undef AI_ALL
+#undef AI_ADDRCONFIG
+#undef AI_DEFAULT
+
+#define AI_V4MAPPED   0x00000008
+#define AI_ALL	      0x00000010
+#define AI_ADDRCONFIG 0x00000020
+#define AI_DEFAULT    (AI_V4MAPPED | AI_ADDRCONFIG)
+
+/*
+ * Constants for getnameinfo()
+ */
+#undef NI_MAXHOST
+#undef NI_MAXSERV
+
+#define NI_MAXHOST 1025
+#define NI_MAXSERV 32
+
+/*
+ * Flag values for getnameinfo()
+ */
+#undef NI_NOFQDN
+#undef NI_NUMERICHOST
+#undef NI_NAMEREQD
+#undef NI_NUMERICSERV
+#undef NI_DGRAM
+#undef NI_NUMERICSCOPE
+
+#define NI_NOFQDN      0x00000001
+#define NI_NUMERICHOST 0x00000002
+#define NI_NAMEREQD    0x00000004
+#define NI_NUMERICSERV 0x00000008
+#define NI_DGRAM       0x00000010
+
+/*
+ * Define to map into irs_ namespace.
+ */
+
+#define IRS_NAMESPACE
+
+#ifdef IRS_NAMESPACE
+
+/*
+ * Use our versions not the ones from the C library.
+ */
+
+#ifdef getnameinfo
+#undef getnameinfo
+#endif /* ifdef getnameinfo */
+#define getnameinfo irs_getnameinfo
+
+#ifdef getaddrinfo
+#undef getaddrinfo
+#endif /* ifdef getaddrinfo */
+#define getaddrinfo irs_getaddrinfo
+
+#ifdef freeaddrinfo
+#undef freeaddrinfo
+#endif /* ifdef freeaddrinfo */
+#define freeaddrinfo irs_freeaddrinfo
+
+#ifdef gai_strerror
+#undef gai_strerror
+#endif /* ifdef gai_strerror */
+#define gai_strerror irs_gai_strerror
+
+#endif /* ifdef IRS_NAMESPACE */
+
+int
+getaddrinfo(const char *, const char *, const struct addrinfo *,
+	    struct addrinfo **);
+int
+getnameinfo(const struct sockaddr *, socklen_t, char *, DWORD, char *, DWORD,
+	    int);
+void
+freeaddrinfo(struct addrinfo *);
+char *
+gai_strerror(int);
+
+/*
+ * Tell Emacs to use C mode on this file.
+ * Local variables:
+ * mode: c
+ * End:
+ */
+
+#endif /* IRS_NETDB_H */
diff --git a/lib/irs/win32/include/irs/platform.h b/lib/irs/win32/include/irs/platform.h
new file mode 100644
index 0000000..2f0cced
--- /dev/null
+++ b/lib/irs/win32/include/irs/platform.h
@@ -0,0 +1,34 @@
+/*
+ * 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 https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+/*! \file */
+
+#ifndef IRS_PLATFORM_H
+#define IRS_PLATFORM_H 1
+
+/*****
+***** Platform-dependent defines.
+*****/
+
+#ifdef LIBIRS_EXPORTS
+#define LIBIRS_EXTERNAL_DATA __declspec(dllexport)
+#else /* ifdef LIBIRS_EXPORTS */
+#define LIBIRS_EXTERNAL_DATA __declspec(dllimport)
+#endif /* ifdef LIBIRS_EXPORTS */
+
+/*
+ * Tell Emacs to use C mode on this file.
+ * Local Variables:
+ * mode: c
+ * End:
+ */
+
+#endif /* IRS_PLATFORM_H */
diff --git a/lib/irs/win32/libirs.def b/lib/irs/win32/libirs.def
new file mode 100644
index 0000000..d4e9f6f
--- /dev/null
+++ b/lib/irs/win32/libirs.def
@@ -0,0 +1,27 @@
+LIBRARY libirs
+
+; Exported Functions
+EXPORTS
+irs_context_create
+irs_context_destroy
+irs_context_get
+irs_context_getappctx
+irs_context_getdnsclient
+irs_context_getdnsconf
+irs_context_getmctx
+irs_context_getresconf
+irs_context_gettask
+irs_context_gettaskmgr
+irs_context_gettimermgr
+irs_dnsconf_destroy
+irs_dnsconf_gettrustedkeys
+irs_dnsconf_load
+irs_freeaddrinfo
+irs_gai_strerror
+irs_getaddrinfo
+irs_getnameinfo
+irs_resconf_destroy
+irs_resconf_getnameservers
+irs_resconf_getndots
+irs_resconf_getsearchlist
+irs_resconf_load
diff --git a/lib/irs/win32/libirs.vcxproj.filters.in b/lib/irs/win32/libirs.vcxproj.filters.in
new file mode 100644
index 0000000..0ffbc07
--- /dev/null
+++ b/lib/irs/win32/libirs.vcxproj.filters.in
@@ -0,0 +1,69 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <ItemGroup>
+    <Filter Include="Source Files">
+      <UniqueIdentifier>{4FC737F1-C7A5-4376-A066-2A32D752A2FF}</UniqueIdentifier>
+      <Extensions>cpp;c;cc;cxx;def;odl;idl;hpj;bat;asm;asmx</Extensions>
+    </Filter>
+    <Filter Include="Header Files">
+      <UniqueIdentifier>{93995380-89BD-4b04-88EB-625FBE52EBFB}</UniqueIdentifier>
+      <Extensions>h;hpp;hxx;hm;inl;inc;xsd</Extensions>
+    </Filter>
+    <Filter Include="Resource Files">
+      <UniqueIdentifier>{67DA6AB6-F800-4c08-8B7A-83BB121AAD01}</UniqueIdentifier>
+      <Extensions>rc;ico;cur;bmp;dlg;rc2;rct;bin;rgs;gif;jpg;jpeg;jpe;resx;tiff;tif;png;wav;mfcribbon-ms</Extensions>
+    </Filter>
+  </ItemGroup>
+  <ItemGroup>
+    <None Include="libirs.def" />
+  </ItemGroup>
+  <ItemGroup>
+    <ClCompile Include="DLLMain.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
+    <ClCompile Include="version.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
+    <ClCompile Include="..\context.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
+    <ClCompile Include="..\dnsconf.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
+    <ClCompile Include="..\gai_strerror.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
+    <ClCompile Include="..\getaddrinfo.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
+    <ClCompile Include="..\getnameinfo.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
+    <ClCompile Include="resconf.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
+  </ItemGroup>
+  <ItemGroup>
+    <ClInclude Include="..\include\irs\context.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
+    <ClInclude Include="..\include\irs\dnsconf.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
+    <ClInclude Include="..\include\irs\netdb.h.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
+    <ClInclude Include="..\include\irs\platform.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
+    <ClInclude Include="..\include\irs\resconf.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
+    <ClInclude Include="..\include\irs\types.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
+    <ClInclude Include="..\include\irs\version.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
+  </ItemGroup>
+</Project>
diff --git a/lib/irs/win32/libirs.vcxproj.in b/lib/irs/win32/libirs.vcxproj.in
new file mode 100644
index 0000000..078ec92
--- /dev/null
+++ b/lib/irs/win32/libirs.vcxproj.in
@@ -0,0 +1,142 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project DefaultTargets="Build" ToolsVersion="@TOOLS_VERSION@" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <ItemGroup Label="ProjectConfigurations">
+    <ProjectConfiguration Include="Debug|@PLATFORM@">
+      <Configuration>Debug</Configuration>
+      <Platform>@PLATFORM@</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Release|@PLATFORM@">
+      <Configuration>Release</Configuration>
+      <Platform>@PLATFORM@</Platform>
+    </ProjectConfiguration>
+  </ItemGroup>
+  <PropertyGroup Label="Globals">
+    <ProjectGuid>{A4F29CEB-7644-4A7F-BE9E-02B6A90E4919}</ProjectGuid>
+    <Keyword>Win32Proj</Keyword>
+    <RootNamespace>libirs</RootNamespace>
+    @WINDOWS_TARGET_PLATFORM_VERSION@
+  </PropertyGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|@PLATFORM@'" Label="Configuration">
+    <ConfigurationType>DynamicLibrary</ConfigurationType>
+    <UseDebugLibraries>true</UseDebugLibraries>
+    <CharacterSet>MultiByte</CharacterSet>
+    @PLATFORM_TOOLSET@
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|@PLATFORM@'" Label="Configuration">
+    <ConfigurationType>DynamicLibrary</ConfigurationType>
+    <UseDebugLibraries>false</UseDebugLibraries>
+    <WholeProgramOptimization>true</WholeProgramOptimization>
+    <CharacterSet>MultiByte</CharacterSet>
+    @PLATFORM_TOOLSET@
+  </PropertyGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
+  <ImportGroup Label="ExtensionSettings">
+  </ImportGroup>
+  <ImportGroup Label="PropertySheets" Condition="'$(Configuration)|$(Platform)'=='Debug|@PLATFORM@'">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
+  </ImportGroup>
+  <ImportGroup Label="PropertySheets" Condition="'$(Configuration)|$(Platform)'=='Release|@PLATFORM@'">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
+  </ImportGroup>
+  <PropertyGroup Label="UserMacros" />
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|@PLATFORM@'">
+    <LinkIncremental>true</LinkIncremental>
+    <OutDir>..\..\..\Build\$(Configuration)\</OutDir>
+    <IntDir>.\$(Configuration)\</IntDir>
+    <IntDirSharingDetected>None</IntDirSharingDetected>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|@PLATFORM@'">
+    <LinkIncremental>false</LinkIncremental>
+    <OutDir>..\..\..\Build\$(Configuration)\</OutDir>
+    <IntDir>.\$(Configuration)\</IntDir>
+    <IntDirSharingDetected>None</IntDirSharingDetected>
+  </PropertyGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|@PLATFORM@'">
+    <ClCompile>
+      <PrecompiledHeader>
+      </PrecompiledHeader>
+      <WarningLevel>Level4</WarningLevel>
+      <TreatWarningAsError>false</TreatWarningAsError>
+      <Optimization>Disabled</Optimization>
+      <PreprocessorDefinitions>WIN32;_DEBUG;_WINDOWS;_USRDLL;LIBIRS_EXPORTS;%(PreprocessorDefinitions);%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <ForcedIncludeFiles>..\..\..\config.h</ForcedIncludeFiles>
+      <AdditionalIncludeDirectories>.\;..\..\..\;include;..\include;..\..\isc\win32;..\..\isc\win32\include;..\..\isc\include;..\..\isccfg\include;..\..\dns\include;@LIBXML2_INC@@OPENSSL_INC@@GEOIP_INC@%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <FunctionLevelLinking>true</FunctionLevelLinking>
+      <PrecompiledHeaderOutputFile>.\$(Configuration)\$(TargetName).pch</PrecompiledHeaderOutputFile>
+      <AssemblerListingLocation>.\$(Configuration)\</AssemblerListingLocation>
+      <ObjectFileName>.\$(Configuration)\</ObjectFileName>
+      <ProgramDataBaseFileName>$(OutDir)$(TargetName).pdb</ProgramDataBaseFileName>
+      <BrowseInformation>true</BrowseInformation>
+      <CompileAs>CompileAsC</CompileAs>
+    </ClCompile>
+    <Link>
+      <SubSystem>Console</SubSystem>
+      <GenerateDebugInformation>true</GenerateDebugInformation>
+      <AdditionalLibraryDirectories>..\..\isc\win32\$(Configuration);..\..\dns\win32\$(Configuration);..\..\isccfg\win32\$(Configuration);%(AdditionalLibraryDirectories)</AdditionalLibraryDirectories>
+      <AdditionalDependencies>@OPENSSL_LIBCRYPTO@@OPENSSL_LIBSSL@libisc.lib;libdns.lib;libisccfg.lib;ws2_32.lib;iphlpapi.lib;%(AdditionalDependencies)</AdditionalDependencies>
+      <ModuleDefinitionFile>.\libirs.def</ModuleDefinitionFile>
+      <ImportLibrary>.\$(Configuration)\$(ProjectName).lib</ImportLibrary>
+      <OutputFile>..\..\..\Build\$(Configuration)\$(TargetName)$(TargetExt)</OutputFile>
+    </Link>
+  </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|@PLATFORM@'">
+    <ClCompile>
+      <WarningLevel>Level1</WarningLevel>
+      <TreatWarningAsError>true</TreatWarningAsError>
+      <PrecompiledHeader>
+      </PrecompiledHeader>
+      <Optimization>MaxSpeed</Optimization>
+      <FunctionLevelLinking>true</FunctionLevelLinking>
+      <IntrinsicFunctions>@INTRINSIC@</IntrinsicFunctions>
+      <PreprocessorDefinitions>WIN32;NDEBUG;_WINDOWS;_USRDLL;LIBIRS_EXPORTS;%(PreprocessorDefinitions);%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <ForcedIncludeFiles>..\..\..\config.h</ForcedIncludeFiles>
+      <AdditionalIncludeDirectories>.\;..\..\..\;include;..\include;..\..\isc\win32;..\..\isc\win32\include;..\..\isc\include;..\..\isccfg\include;..\..\dns\include;@LIBXML2_INC@@OPENSSL_INC@@GEOIP_INC@%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <InlineFunctionExpansion>OnlyExplicitInline</InlineFunctionExpansion>
+      <WholeProgramOptimization>false</WholeProgramOptimization>
+      <StringPooling>true</StringPooling>
+      <PrecompiledHeaderOutputFile>.\$(Configuration)\$(TargetName).pch</PrecompiledHeaderOutputFile>
+      <AssemblerListingLocation>.\$(Configuration)\</AssemblerListingLocation>
+      <ObjectFileName>.\$(Configuration)\</ObjectFileName>
+      <ProgramDataBaseFileName>$(OutDir)$(TargetName).pdb</ProgramDataBaseFileName>
+      <CompileAs>CompileAsC</CompileAs>
+    </ClCompile>
+    <Link>
+      <SubSystem>Console</SubSystem>
+      <GenerateDebugInformation>false</GenerateDebugInformation>
+      <EnableCOMDATFolding>true</EnableCOMDATFolding>
+      <OptimizeReferences>true</OptimizeReferences>
+      <AdditionalLibraryDirectories>..\..\isc\win32\$(Configuration);..\..\dns\win32\$(Configuration);..\..\isccfg\win32\$(Configuration);%(AdditionalLibraryDirectories)</AdditionalLibraryDirectories>
+      <AdditionalDependencies>@OPENSSL_LIBCRYPTO@@OPENSSL_LIBSSL@libisc.lib;libdns.lib;libisccfg.lib;ws2_32.lib;iphlpapi.lib;%(AdditionalDependencies)</AdditionalDependencies>
+      <ModuleDefinitionFile>.\libirs.def</ModuleDefinitionFile>
+      <ImportLibrary>.\$(Configuration)\$(ProjectName).lib</ImportLibrary>
+      <LinkTimeCodeGeneration>Default</LinkTimeCodeGeneration>
+      <OutputFile>..\..\..\Build\$(Configuration)\$(TargetName)$(TargetExt)</OutputFile>
+    </Link>
+  </ItemDefinitionGroup>
+  <ItemGroup>
+    <None Include="libirs.def" />
+  </ItemGroup>
+  <ItemGroup>
+    <ClCompile Include="..\context.c" />
+    <ClCompile Include="..\dnsconf.c" />
+    <ClCompile Include="..\gai_strerror.c" />
+    <ClCompile Include="..\getaddrinfo.c" />
+    <ClCompile Include="..\getnameinfo.c" />
+    <ClCompile Include="DLLMain.c" />
+    <ClCompile Include="resconf.c" />
+    <ClCompile Include="version.c" />
+  </ItemGroup>
+  <ItemGroup>
+    <ClInclude Include="..\include\irs\context.h" />
+    <ClInclude Include="..\include\irs\dnsconf.h" />
+    <ClInclude Include="..\include\irs\netdb.h" />
+    <ClInclude Include="..\include\irs\platform.h" />
+    <ClInclude Include="..\include\irs\resconf.h" />
+    <ClInclude Include="..\include\irs\types.h" />
+    <ClInclude Include="..\include\irs\version.h" />
+  </ItemGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
+  <ImportGroup Label="ExtensionTargets">
+  </ImportGroup>
+</Project>
diff --git a/lib/irs/win32/libirs.vcxproj.user b/lib/irs/win32/libirs.vcxproj.user
new file mode 100644
index 0000000..ace9a86
--- /dev/null
+++ b/lib/irs/win32/libirs.vcxproj.user
@@ -0,0 +1,3 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+</Project>
\ No newline at end of file
diff --git a/lib/irs/win32/resconf.c b/lib/irs/win32/resconf.c
new file mode 100644
index 0000000..3b46b8e
--- /dev/null
+++ b/lib/irs/win32/resconf.c
@@ -0,0 +1,130 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ *
+ * 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 https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+/*
+ * Note that on Win32 there is normally no resolv.conf since all information
+ * is stored in the registry. Therefore there is no ordering like the
+ * contents of resolv.conf. Since the "search" or "domain" keyword, on
+ * Win32 if a search list is found it is used, otherwise the domain name
+ * is used since they are mutually exclusive. The search list can be entered
+ * in the DNS tab of the "Advanced TCP/IP settings" window under the same place
+ * that you add your nameserver list.
+ */
+
+#define HAVE_GET_WIN32_NAMESERVERS 1
+
+#include "../resconf.c"
+#include <iphlpapi.h>
+
+#define TCPIP_SUBKEY "SYSTEM\\CurrentControlSet\\Services\\Tcpip\\Parameters"
+
+isc_result_t
+get_win32_searchlist(irs_resconf_t *conf) {
+	isc_result_t result = ISC_R_SUCCESS;
+	HKEY hKey;
+	char searchlist[MAX_PATH];
+	DWORD searchlen = MAX_PATH;
+	LSTATUS status;
+	char *cp;
+
+	REQUIRE(conf != NULL);
+
+	memset(searchlist, 0, MAX_PATH);
+	status = RegOpenKeyEx(HKEY_LOCAL_MACHINE, TCPIP_SUBKEY, 0, KEY_READ,
+			      &hKey);
+	if (status != ERROR_SUCCESS) {
+		return (ISC_R_SUCCESS);
+	}
+
+	status = RegQueryValueEx(hKey, "SearchList", NULL, NULL,
+				 (LPBYTE)searchlist, &searchlen);
+	RegCloseKey(hKey);
+	if (status != ERROR_SUCCESS) {
+		return (ISC_R_SUCCESS);
+	}
+
+	cp = strtok((char *)searchlist, ", \0");
+	while (cp != NULL) {
+		result = add_search(conf, cp);
+		if (result != ISC_R_SUCCESS) {
+			break;
+		}
+		cp = strtok(NULL, ", \0");
+	}
+	return (result);
+}
+
+isc_result_t
+get_win32_nameservers(irs_resconf_t *conf) {
+	isc_result_t result;
+	FIXED_INFO *FixedInfo;
+	ULONG BufLen = sizeof(FIXED_INFO);
+	DWORD dwRetVal;
+	IP_ADDR_STRING *pIPAddr;
+
+	REQUIRE(conf != NULL);
+
+	FixedInfo = (FIXED_INFO *)GlobalAlloc(GPTR, BufLen);
+	if (FixedInfo == NULL) {
+		return (ISC_R_NOMEMORY);
+	}
+	dwRetVal = GetNetworkParams(FixedInfo, &BufLen);
+	if (dwRetVal == ERROR_BUFFER_OVERFLOW) {
+		GlobalFree(FixedInfo);
+		FixedInfo = GlobalAlloc(GPTR, BufLen);
+		if (FixedInfo == NULL) {
+			return (ISC_R_NOMEMORY);
+		}
+		dwRetVal = GetNetworkParams(FixedInfo, &BufLen);
+	}
+	if (dwRetVal != ERROR_SUCCESS) {
+		GlobalFree(FixedInfo);
+		return (ISC_R_FAILURE);
+	}
+
+	result = get_win32_searchlist(conf);
+	if (result != ISC_R_SUCCESS) {
+		goto cleanup;
+	}
+
+	if (ISC_LIST_EMPTY(conf->searchlist) &&
+	    strlen(FixedInfo->DomainName) > 0)
+	{
+		result = add_search(conf, FixedInfo->DomainName);
+		if (result != ISC_R_SUCCESS) {
+			goto cleanup;
+		}
+	}
+
+	/* Get the list of nameservers */
+	pIPAddr = &FixedInfo->DnsServerList;
+	while (pIPAddr) {
+		if (conf->numns >= RESCONFMAXNAMESERVERS) {
+			break;
+		}
+
+		result = add_server(conf->mctx, pIPAddr->IpAddress.String,
+				    &conf->nameservers);
+		if (result != ISC_R_SUCCESS) {
+			break;
+		}
+		conf->numns++;
+		pIPAddr = pIPAddr->Next;
+	}
+
+cleanup:
+	if (FixedInfo != NULL) {
+		GlobalFree(FixedInfo);
+	}
+	return (result);
+}
diff --git a/lib/irs/win32/version.c b/lib/irs/win32/version.c
new file mode 100644
index 0000000..3c635ad
--- /dev/null
+++ b/lib/irs/win32/version.c
@@ -0,0 +1,18 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ *
+ * 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 https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+#include <versions.h>
+
+#include <irs/version.h>
+
+LIBIRS_EXTERNAL_DATA const char irs_version[] = VERSION;