/*
 * 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 <inttypes.h>
#include <stdbool.h>
#include <stdlib.h>

#include <isc/log.h>
#include <isc/mem.h>
#include <isc/string.h>
#include <isc/util.h>

#include <dns/acl.h>
#include <dns/fixedname.h>
#include <dns/iptable.h>

#include <isccfg/aclconf.h>
#include <isccfg/namedconf.h>

#define LOOP_MAGIC ISC_MAGIC('L', 'O', 'O', 'P')

#if defined(HAVE_GEOIP2)
static const char *geoip_dbnames[] = {
	"country", "city", "asnum", "isp", "domain", NULL,
};
#endif /* if defined(HAVE_GEOIP2) */

isc_result_t
cfg_aclconfctx_create(isc_mem_t *mctx, cfg_aclconfctx_t **aclctxp) {
	cfg_aclconfctx_t *aclctx;

	REQUIRE(mctx != NULL);
	REQUIRE(aclctxp != NULL && *aclctxp == NULL);

	aclctx = isc_mem_get(mctx, sizeof(*aclctx));

	isc_refcount_init(&aclctx->references, 1);

	aclctx->mctx = NULL;
	isc_mem_attach(mctx, &aclctx->mctx);
	ISC_LIST_INIT(aclctx->named_acl_cache);

#if defined(HAVE_GEOIP2)
	aclctx->geoip = NULL;
#endif /* if defined(HAVE_GEOIP2) */

	*aclctxp = aclctx;
	return ISC_R_SUCCESS;
}

static void
destroy_aclctx(cfg_aclconfctx_t *aclctx) {
	isc_refcount_destroy(&aclctx->references);
	ISC_LIST_FOREACH(aclctx->named_acl_cache, dacl, nextincache) {
		ISC_LIST_UNLINK(aclctx->named_acl_cache, dacl, nextincache);
		dns_acl_detach(&dacl);
	}
	isc_mem_putanddetach(&aclctx->mctx, aclctx, sizeof(*aclctx));
}

ISC_REFCOUNT_IMPL(cfg_aclconfctx, destroy_aclctx);

/*
 * Find the definition of the named acl whose name is "name".
 */
static isc_result_t
get_acl_def(const cfg_obj_t *cctx, const char *name, const cfg_obj_t **ret) {
	const cfg_obj_t *acls = NULL;

	RETERR(cfg_map_get(cctx, "acl", &acls));
	CFG_LIST_FOREACH(acls, elt) {
		const cfg_obj_t *acl = cfg_listelt_value(elt);
		const char *aclname =
			cfg_obj_asstring(cfg_tuple_get(acl, "name"));
		if (strcasecmp(aclname, name) == 0) {
			SET_IF_NOT_NULL(ret, cfg_tuple_get(acl, "value"));
			return ISC_R_SUCCESS;
		}
	}
	return ISC_R_NOTFOUND;
}

static isc_result_t
convert_named_acl(const cfg_obj_t *nameobj, const cfg_obj_t *cctx,
		  cfg_aclconfctx_t *ctx, isc_mem_t *mctx,
		  unsigned int nest_level, dns_acl_t **target) {
	isc_result_t result;
	const cfg_obj_t *cacl = NULL;
	dns_acl_t loop, *acl = NULL;
	const char *aclname = cfg_obj_asstring(nameobj);

	/* Look for an already-converted version. */
	ISC_LIST_FOREACH(ctx->named_acl_cache, dacl, nextincache) {
		if (strcasecmp(aclname, dacl->name) == 0) {
			if (ISC_MAGIC_VALID(dacl, LOOP_MAGIC)) {
				cfg_obj_log(nameobj, ISC_LOG_ERROR,
					    "acl loop detected: %s", aclname);
				return ISC_R_FAILURE;
			}
			dns_acl_attach(dacl, target);
			return ISC_R_SUCCESS;
		}
	}
	/* Not yet converted.  Convert now. */
	result = get_acl_def(cctx, aclname, &cacl);
	if (result != ISC_R_SUCCESS) {
		cfg_obj_log(nameobj, ISC_LOG_WARNING, "undefined ACL '%s'",
			    aclname);
		return result;
	}
	/*
	 * Add a loop detection element.
	 */
	memset(&loop, 0, sizeof(loop));
	ISC_LINK_INIT(&loop, nextincache);
	loop.name = UNCONST(aclname);
	loop.magic = LOOP_MAGIC;
	ISC_LIST_APPEND(ctx->named_acl_cache, &loop, nextincache);
	result = cfg_acl_fromconfig(cacl, cctx, ctx, mctx, nest_level, &acl);
	ISC_LIST_UNLINK(ctx->named_acl_cache, &loop, nextincache);
	loop.magic = 0;
	loop.name = NULL;
	if (result != ISC_R_SUCCESS) {
		return result;
	}
	acl->name = isc_mem_strdup(acl->mctx, aclname);
	ISC_LIST_APPEND(ctx->named_acl_cache, acl, nextincache);
	dns_acl_attach(acl, target);
	return ISC_R_SUCCESS;
}

static isc_result_t
convert_keyname(const cfg_obj_t *keyobj, isc_mem_t *mctx, dns_name_t *dnsname) {
	isc_result_t result;
	isc_buffer_t buf;
	dns_fixedname_t fixname;
	unsigned int keylen;
	const char *txtname = cfg_obj_asstring(keyobj);

	keylen = strlen(txtname);
	isc_buffer_constinit(&buf, txtname, keylen);
	isc_buffer_add(&buf, keylen);
	dns_fixedname_init(&fixname);
	result = dns_name_fromtext(dns_fixedname_name(&fixname), &buf,
				   dns_rootname, 0);
	if (result != ISC_R_SUCCESS) {
		cfg_obj_log(keyobj, ISC_LOG_WARNING,
			    "key name '%s' is not a valid domain name",
			    txtname);
		return result;
	}
	dns_name_dup(dns_fixedname_name(&fixname), mctx, dnsname);
	return ISC_R_SUCCESS;
}

/*
 * Recursively pre-parse an ACL definition to find the total number
 * of non-IP-prefix elements (localhost, localnets, key) in all nested
 * ACLs, so that the parent will have enough space allocated for the
 * elements table after all the nested ACLs have been merged in to the
 * parent.
 */
static isc_result_t
count_acl_elements(const cfg_obj_t *caml, const cfg_obj_t *cctx,
		   cfg_aclconfctx_t *ctx, isc_mem_t *mctx, uint32_t *count,
		   bool *has_negative) {
	isc_result_t result;
	uint32_t n = 0;

	REQUIRE(count != NULL);

	SET_IF_NOT_NULL(has_negative, false);

	CFG_LIST_FOREACH(caml, elt) {
		const cfg_obj_t *ce = cfg_listelt_value(elt);

		/* might be a negated element, in which case get the value. */
		if (cfg_obj_istuple(ce)) {
			const cfg_obj_t *negated = cfg_tuple_get(ce, "negated");
			if (!cfg_obj_isvoid(negated)) {
				ce = negated;
				SET_IF_NOT_NULL(has_negative, true);
			}
		}

		if (cfg_obj_istype(ce, &cfg_type_keyref)) {
			n++;
		} else if (cfg_obj_islist(ce)) {
			bool negative;
			uint32_t sub;
			RETERR(count_acl_elements(ce, cctx, ctx, mctx, &sub,
						  &negative));
			n += sub;
			if (negative) {
				n++;
			}
#if defined(HAVE_GEOIP2)
		} else if (cfg_obj_istuple(ce) &&
			   cfg_obj_isvoid(cfg_tuple_get(ce, "negated")))
		{
			n++;
#endif /* HAVE_GEOIP2 */
		} else if (cfg_obj_isstring(ce)) {
			const char *name = cfg_obj_asstring(ce);
			if (strcasecmp(name, "localhost") == 0 ||
			    strcasecmp(name, "localnets") == 0 ||
			    strcasecmp(name, "none") == 0)
			{
				n++;
			} else if (strcasecmp(name, "any") != 0) {
				dns_acl_t *inneracl = NULL;
				/*
				 * Convert any named acls we reference now if
				 * they have not already been converted.
				 */
				result = convert_named_acl(ce, cctx, ctx, mctx,
							   0, &inneracl);
				if (result == ISC_R_SUCCESS) {
					if (inneracl->has_negatives) {
						n++;
					} else {
						n += inneracl->length;
					}
					dns_acl_detach(&inneracl);
				} else {
					return result;
				}
			}
		}
	}

	*count = n;
	return ISC_R_SUCCESS;
}

#if defined(HAVE_GEOIP2)
static dns_geoip_subtype_t
get_subtype(const cfg_obj_t *obj, dns_geoip_subtype_t subtype,
	    const char *dbname) {
	if (dbname == NULL) {
		return subtype;
	}

	switch (subtype) {
	case dns_geoip_countrycode:
		if (strcasecmp(dbname, "city") == 0) {
			return dns_geoip_city_countrycode;
		} else if (strcasecmp(dbname, "country") == 0) {
			return dns_geoip_country_code;
		}
		cfg_obj_log(obj, ISC_LOG_ERROR,
			    "invalid database specified for "
			    "country search: ignored");
		return subtype;
	case dns_geoip_countryname:
		if (strcasecmp(dbname, "city") == 0) {
			return dns_geoip_city_countryname;
		} else if (strcasecmp(dbname, "country") == 0) {
			return dns_geoip_country_name;
		}
		cfg_obj_log(obj, ISC_LOG_ERROR,
			    "invalid database specified for "
			    "country search: ignored");
		return subtype;
	case dns_geoip_continentcode:
		if (strcasecmp(dbname, "city") == 0) {
			return dns_geoip_city_continentcode;
		} else if (strcasecmp(dbname, "country") == 0) {
			return dns_geoip_country_continentcode;
		}
		cfg_obj_log(obj, ISC_LOG_ERROR,
			    "invalid database specified for "
			    "continent search: ignored");
		return subtype;
	case dns_geoip_continent:
		if (strcasecmp(dbname, "city") == 0) {
			return dns_geoip_city_continent;
		} else if (strcasecmp(dbname, "country") == 0) {
			return dns_geoip_country_continent;
		}
		cfg_obj_log(obj, ISC_LOG_ERROR,
			    "invalid database specified for "
			    "continent search: ignored");
		return subtype;
	case dns_geoip_region:
		if (strcasecmp(dbname, "city") == 0) {
			return dns_geoip_city_region;
		}
		cfg_obj_log(obj, ISC_LOG_ERROR,
			    "invalid database specified for "
			    "region/subdivision search: ignored");
		return subtype;
	case dns_geoip_regionname:
		if (strcasecmp(dbname, "city") == 0) {
			return dns_geoip_city_regionname;
		}
		cfg_obj_log(obj, ISC_LOG_ERROR,
			    "invalid database specified for "
			    "region/subdivision search: ignored");
		return subtype;

	/*
	 * Log a warning if the wrong database was specified
	 * on an unambiguous query
	 */
	case dns_geoip_city_name:
	case dns_geoip_city_postalcode:
	case dns_geoip_city_metrocode:
	case dns_geoip_city_areacode:
	case dns_geoip_city_timezonecode:
		if (strcasecmp(dbname, "city") != 0) {
			cfg_obj_log(obj, ISC_LOG_WARNING,
				    "invalid database specified for "
				    "a 'city'-only search type: ignoring");
		}
		return subtype;
	case dns_geoip_isp_name:
		if (strcasecmp(dbname, "isp") != 0) {
			cfg_obj_log(obj, ISC_LOG_WARNING,
				    "invalid database specified for "
				    "an 'isp' search: ignoring");
		}
		return subtype;
	case dns_geoip_org_name:
		if (strcasecmp(dbname, "org") != 0) {
			cfg_obj_log(obj, ISC_LOG_WARNING,
				    "invalid database specified for "
				    "an 'org' search: ignoring");
		}
		return subtype;
	case dns_geoip_as_asnum:
		if (strcasecmp(dbname, "asnum") != 0) {
			cfg_obj_log(obj, ISC_LOG_WARNING,
				    "invalid database specified for "
				    "an 'asnum' search: ignoring");
		}
		return subtype;
	case dns_geoip_domain_name:
		if (strcasecmp(dbname, "domain") != 0) {
			cfg_obj_log(obj, ISC_LOG_WARNING,
				    "invalid database specified for "
				    "a 'domain' search: ignoring");
		}
		return subtype;
	case dns_geoip_netspeed_id:
		if (strcasecmp(dbname, "netspeed") != 0) {
			cfg_obj_log(obj, ISC_LOG_WARNING,
				    "invalid database specified for "
				    "a 'netspeed' search: ignoring");
		}
		return subtype;
	default:
		UNREACHABLE();
	}
}

static bool
geoip_can_answer(dns_aclelement_t *elt, cfg_aclconfctx_t *ctx) {
	if (ctx->geoip == NULL) {
		return true;
	}

	switch (elt->geoip_elem.subtype) {
	case dns_geoip_countrycode:
	case dns_geoip_countryname:
	case dns_geoip_continentcode:
	case dns_geoip_continent:
		if (ctx->geoip->country != NULL || ctx->geoip->city != NULL) {
			return true;
		}
		break;
	case dns_geoip_country_code:
	case dns_geoip_country_name:
	case dns_geoip_country_continentcode:
	case dns_geoip_country_continent:
		if (ctx->geoip->country != NULL) {
			return true;
		}
		/* city db can answer these too, so: */
		FALLTHROUGH;
	case dns_geoip_region:
	case dns_geoip_regionname:
	case dns_geoip_city_countrycode:
	case dns_geoip_city_countryname:
	case dns_geoip_city_region:
	case dns_geoip_city_regionname:
	case dns_geoip_city_name:
	case dns_geoip_city_postalcode:
	case dns_geoip_city_metrocode:
	case dns_geoip_city_areacode:
	case dns_geoip_city_continentcode:
	case dns_geoip_city_continent:
	case dns_geoip_city_timezonecode:
		if (ctx->geoip->city != NULL) {
			return true;
		}
		break;
	case dns_geoip_isp_name:
		if (ctx->geoip->isp != NULL) {
			return true;
		}
		break;
	case dns_geoip_as_asnum:
	case dns_geoip_org_name:
		if (ctx->geoip->as != NULL) {
			return true;
		}
		break;
	case dns_geoip_domain_name:
		if (ctx->geoip->domain != NULL) {
			return true;
		}
		break;
	default:
		break;
	}

	return false;
}

static isc_result_t
parse_geoip_element(const cfg_obj_t *obj, cfg_aclconfctx_t *ctx,
		    dns_aclelement_t *dep) {
	const cfg_obj_t *ge;
	const char *dbname = NULL;
	const char *stype = NULL, *search = NULL;
	dns_geoip_subtype_t subtype;
	dns_aclelement_t de;
	size_t len;

	REQUIRE(dep != NULL);

	de = *dep;

	ge = cfg_tuple_get(obj, "db");
	if (!cfg_obj_isvoid(ge)) {
		int i;

		dbname = cfg_obj_asstring(ge);

		for (i = 0; geoip_dbnames[i] != NULL; i++) {
			if (strcasecmp(dbname, geoip_dbnames[i]) == 0) {
				break;
			}
		}
		if (geoip_dbnames[i] == NULL) {
			cfg_obj_log(obj, ISC_LOG_ERROR,
				    "database '%s' is not defined for GeoIP2",
				    dbname);
			return ISC_R_UNEXPECTED;
		}
	}

	stype = cfg_obj_asstring(cfg_tuple_get(obj, "subtype"));
	search = cfg_obj_asstring(cfg_tuple_get(obj, "search"));
	len = strlen(search);

	if (len == 0) {
		cfg_obj_log(obj, ISC_LOG_ERROR,
			    "zero-length geoip search field");
		return ISC_R_FAILURE;
	}

	if (strcasecmp(stype, "country") == 0 && len == 2) {
		/* Two-letter country code */
		subtype = dns_geoip_countrycode;
		strlcpy(de.geoip_elem.as_string, search,
			sizeof(de.geoip_elem.as_string));
	} else if (strcasecmp(stype, "country") == 0 && len == 3) {
		/* Three-letter country code */
		cfg_obj_log(obj, ISC_LOG_ERROR,
			    "three-letter country codes are unavailable "
			    "in GeoIP2 databases");
		return ISC_R_FAILURE;
	} else if (strcasecmp(stype, "country") == 0) {
		/* Country name */
		subtype = dns_geoip_countryname;
		strlcpy(de.geoip_elem.as_string, search,
			sizeof(de.geoip_elem.as_string));
	} else if (strcasecmp(stype, "continent") == 0 && len == 2) {
		/* Two-letter continent code */
		subtype = dns_geoip_continentcode;
		strlcpy(de.geoip_elem.as_string, search,
			sizeof(de.geoip_elem.as_string));
	} else if (strcasecmp(stype, "continent") == 0) {
		subtype = dns_geoip_continent;
		strlcpy(de.geoip_elem.as_string, search,
			sizeof(de.geoip_elem.as_string));
	} else if ((strcasecmp(stype, "region") == 0 ||
		    strcasecmp(stype, "subdivision") == 0) &&
		   len == 2)
	{
		/* Two-letter region code */
		subtype = dns_geoip_region;
		strlcpy(de.geoip_elem.as_string, search,
			sizeof(de.geoip_elem.as_string));
	} else if (strcasecmp(stype, "region") == 0 ||
		   strcasecmp(stype, "subdivision") == 0)
	{
		/* Region name */
		subtype = dns_geoip_regionname;
		strlcpy(de.geoip_elem.as_string, search,
			sizeof(de.geoip_elem.as_string));
	} else if (strcasecmp(stype, "city") == 0) {
		/* City name */
		subtype = dns_geoip_city_name;
		strlcpy(de.geoip_elem.as_string, search,
			sizeof(de.geoip_elem.as_string));
	} else if (strcasecmp(stype, "postal") == 0 ||
		   strcasecmp(stype, "postalcode") == 0)
	{
		if (len < 7) {
			subtype = dns_geoip_city_postalcode;
			strlcpy(de.geoip_elem.as_string, search,
				sizeof(de.geoip_elem.as_string));
		} else {
			cfg_obj_log(obj, ISC_LOG_ERROR,
				    "geoiop postal code (%s) too long", search);
			return ISC_R_FAILURE;
		}
	} else if (strcasecmp(stype, "metro") == 0 ||
		   strcasecmp(stype, "metrocode") == 0)
	{
		subtype = dns_geoip_city_metrocode;
		de.geoip_elem.as_int = atoi(search);
	} else if (strcasecmp(stype, "tz") == 0 ||
		   strcasecmp(stype, "timezone") == 0)
	{
		subtype = dns_geoip_city_timezonecode;
		strlcpy(de.geoip_elem.as_string, search,
			sizeof(de.geoip_elem.as_string));
	} else if (strcasecmp(stype, "isp") == 0) {
		subtype = dns_geoip_isp_name;
		strlcpy(de.geoip_elem.as_string, search,
			sizeof(de.geoip_elem.as_string));
	} else if (strcasecmp(stype, "asnum") == 0) {
		subtype = dns_geoip_as_asnum;
		strlcpy(de.geoip_elem.as_string, search,
			sizeof(de.geoip_elem.as_string));
	} else if (strcasecmp(stype, "org") == 0) {
		subtype = dns_geoip_org_name;
		strlcpy(de.geoip_elem.as_string, search,
			sizeof(de.geoip_elem.as_string));
	} else if (strcasecmp(stype, "domain") == 0) {
		subtype = dns_geoip_domain_name;
		strlcpy(de.geoip_elem.as_string, search,
			sizeof(de.geoip_elem.as_string));
	} else {
		cfg_obj_log(obj, ISC_LOG_ERROR,
			    "type '%s' is unavailable "
			    "in GeoIP2 databases",
			    stype);
		return ISC_R_FAILURE;
	}

	de.geoip_elem.subtype = get_subtype(obj, subtype, dbname);

	if (!geoip_can_answer(&de, ctx)) {
		cfg_obj_log(obj, ISC_LOG_ERROR,
			    "no GeoIP2 database installed which can answer "
			    "queries of type '%s'",
			    stype);
		return ISC_R_FAILURE;
	}

	*dep = de;

	return ISC_R_SUCCESS;
}
#endif /* HAVE_GEOIP2 */

isc_result_t
cfg_acl_fromconfig(const cfg_obj_t *acl_data, const cfg_obj_t *cctx,
		   cfg_aclconfctx_t *ctx, isc_mem_t *mctx,
		   unsigned int nest_level, dns_acl_t **target) {
	isc_result_t result;
	dns_acl_t *dacl = NULL, *inneracl = NULL;
	dns_aclelement_t *de = NULL;
	dns_iptable_t *iptab = NULL;
	int new_nest_level = 0;
	bool setpos;
	const cfg_obj_t *caml = NULL;
	const cfg_obj_t *obj_acl_tuple = NULL;
	const cfg_obj_t *obj_port = NULL, *obj_transport = NULL;
	bool is_tuple = false;

	if (nest_level != 0) {
		new_nest_level = nest_level - 1;
	}

	REQUIRE(ctx != NULL);
	REQUIRE(target != NULL);
	REQUIRE(*target == NULL || DNS_ACL_VALID(*target));

	REQUIRE(acl_data != NULL);
	if (cfg_obj_islist(acl_data)) {
		caml = acl_data;
	} else {
		INSIST(cfg_obj_istuple(acl_data));
		caml = cfg_tuple_get(acl_data, "aml");
		INSIST(caml != NULL);
		obj_acl_tuple = cfg_tuple_get(acl_data, "port-transport");
		INSIST(obj_acl_tuple != NULL);
		obj_port = cfg_tuple_get(obj_acl_tuple, "port");
		obj_transport = cfg_tuple_get(obj_acl_tuple, "transport");
		is_tuple = true;
	}

	if (*target != NULL) {
		/*
		 * If target already points to an ACL, then we're being
		 * called recursively to configure a nested ACL.  The
		 * nested ACL's contents should just be absorbed into its
		 * parent ACL.
		 */
		dns_acl_attach(*target, &dacl);
		dns_acl_detach(target);
	} else {
		/*
		 * Need to allocate a new ACL structure.  Count the items
		 * in the ACL definition that will require space in the
		 * elements table.  (Note that if nest_level is nonzero,
		 * *everything* goes in the elements table.)
		 */
		uint32_t nelem;

		if (nest_level == 0) {
			RETERR(count_acl_elements(caml, cctx, ctx, mctx, &nelem,
						  NULL));
		} else {
			nelem = cfg_list_length(caml, false);
		}

		dns_acl_create(mctx, nelem, &dacl);
	}

	if (is_tuple) {
		uint16_t port = 0;
		uint32_t transports = 0;
		bool encrypted = false;

		if (obj_port != NULL && cfg_obj_isuint32(obj_port)) {
			port = (uint16_t)cfg_obj_asuint32(obj_port);
		}

		if (obj_transport != NULL && cfg_obj_isstring(obj_transport)) {
			if (strcasecmp(cfg_obj_asstring(obj_transport),
				       "udp") == 0)
			{
				transports = isc_nm_udpsocket |
					     isc_nm_proxyudpsocket;
				encrypted = false;
			} else if (strcasecmp(cfg_obj_asstring(obj_transport),
					      "tcp") == 0)
			{
				transports = isc_nm_streamdnssocket;
				encrypted = false;
			} else if (strcasecmp(cfg_obj_asstring(obj_transport),
					      "udp-tcp") == 0)
			{
				/* Good ol' DNS over port 53 */
				transports = isc_nm_streamdnssocket |
					     isc_nm_udpsocket |
					     isc_nm_proxyudpsocket;
				encrypted = false;
			} else if (strcasecmp(cfg_obj_asstring(obj_transport),
					      "tls") == 0)
			{
				transports = isc_nm_streamdnssocket;
				encrypted = true;
			} else if (strcasecmp(cfg_obj_asstring(obj_transport),
					      "http") == 0)
			{
				transports = isc_nm_httpsocket;
				encrypted = true;
			} else if (strcasecmp(cfg_obj_asstring(obj_transport),
					      "http-plain") == 0)
			{
				transports = isc_nm_httpsocket;
				encrypted = false;
			} else {
				CLEANUP(ISC_R_FAILURE);
			}
		}

		if (port != 0 || transports != 0) {
			dns_acl_add_port_transports(dacl, port, transports,
						    encrypted, false);
		}
	}

	de = dacl->elements;
	CFG_LIST_FOREACH(caml, elt) {
		const cfg_obj_t *ce = cfg_listelt_value(elt);
		bool neg = false;

		INSIST(dacl->length <= dacl->alloc);

		if (cfg_obj_istuple(ce)) {
			/* Might be a negated element */
			const cfg_obj_t *negated = cfg_tuple_get(ce, "negated");
			if (!cfg_obj_isvoid(negated)) {
				neg = true;
				dacl->has_negatives = true;
				ce = negated;
			}
		}

		/*
		 * If nest_level is nonzero, then every element is
		 * to be stored as a separate, nested ACL rather than
		 * merged into the main iptable.
		 */
		iptab = dacl->iptable;

		if (nest_level != 0) {
			dns_acl_create(mctx, cfg_list_length(ce, false),
				       &de->nestedacl);
			iptab = de->nestedacl->iptable;
		}

		if (cfg_obj_isnetprefix(ce)) {
			/* Network prefix */
			isc_netaddr_t addr;
			unsigned int bitlen;

			cfg_obj_asnetprefix(ce, &addr, &bitlen);
			result = isc_netaddr_prefixok(&addr, bitlen);
			if (result != ISC_R_SUCCESS) {
				char buf[ISC_NETADDR_FORMATSIZE + 1];
				isc_netaddr_format(&addr, buf, sizeof(buf));
				cfg_obj_log(ce, ISC_LOG_ERROR,
					    "'%s/%u': address/prefix length "
					    "mismatch",
					    buf, bitlen);
				goto cleanup;
			}

			/*
			 * If nesting ACLs (nest_level != 0), we negate
			 * the nestedacl element, not the iptable entry.
			 */
			setpos = (nest_level != 0 || !neg);
			CHECK(dns_iptable_addprefix(iptab, &addr, bitlen,
						    setpos));

			if (nest_level > 0) {
				INSIST(dacl->length < dacl->alloc);
				de->type = dns_aclelementtype_nestedacl;
				de->negative = neg;
			} else {
				continue;
			}
		} else if (cfg_obj_islist(ce)) {
			/*
			 * If we're nesting ACLs, put the nested
			 * ACL onto the elements list; otherwise
			 * merge it into *this* ACL.  We nest the
			 * ACL if it contains negated members.
			 */
			if (inneracl != NULL) {
				dns_acl_detach(&inneracl);
			}
			CHECK(cfg_acl_fromconfig(ce, cctx, ctx, mctx,
						 new_nest_level, &inneracl));
		nested_acl:
			if (nest_level > 0 || inneracl->has_negatives) {
				INSIST(dacl->length < dacl->alloc);
				de->type = dns_aclelementtype_nestedacl;
				de->negative = neg;
				if (de->nestedacl != NULL) {
					dns_acl_detach(&de->nestedacl);
				}
				/*
				 * Merge the port-transports entries from the
				 * nested ACL into its parent.
				 */
				dns_acl_merge_ports_transports(dacl, inneracl,
							       !neg);
				dns_acl_attach(inneracl, &de->nestedacl);
				dns_acl_detach(&inneracl);
				/* Fall through. */
			} else {
				INSIST(dacl->length + inneracl->length <=
				       dacl->alloc);
				dns_acl_merge(dacl, inneracl, !neg);
				de += inneracl->length; /* elements added */
				dns_acl_detach(&inneracl);
				INSIST(dacl->length <= dacl->alloc);
				continue;
			}
		} else if (cfg_obj_istype(ce, &cfg_type_keyref)) {
			/* Key name. */
			INSIST(dacl->length < dacl->alloc);
			de->type = dns_aclelementtype_keyname;
			de->negative = neg;
			dns_name_init(&de->keyname);
			CHECK(convert_keyname(ce, mctx, &de->keyname));
#if defined(HAVE_GEOIP2)
		} else if (cfg_obj_istuple(ce) &&
			   cfg_obj_isvoid(cfg_tuple_get(ce, "negated")))
		{
			INSIST(dacl->length < dacl->alloc);
			CHECK(parse_geoip_element(ce, ctx, de));
			de->type = dns_aclelementtype_geoip;
			de->negative = neg;
#endif /* HAVE_GEOIP2 */
		} else if (cfg_obj_isstring(ce)) {
			/* ACL name. */
			const char *name = cfg_obj_asstring(ce);
			if (strcasecmp(name, "any") == 0) {
				/* Iptable entry with zero bit length. */
				setpos = (nest_level != 0 || !neg);
				CHECK(dns_iptable_addprefix(iptab, NULL, 0,
							    setpos));

				if (nest_level != 0) {
					INSIST(dacl->length < dacl->alloc);
					de->type = dns_aclelementtype_nestedacl;
					de->negative = neg;
				} else {
					continue;
				}
			} else if (strcasecmp(name, "none") == 0) {
				/* none == !any */
				/*
				 * We don't unconditional set
				 * dacl->has_negatives and
				 * de->negative to true so we can handle
				 * "!none;".
				 */
				setpos = (nest_level != 0 || neg);
				CHECK(dns_iptable_addprefix(iptab, NULL, 0,
							    setpos));

				if (!neg) {
					dacl->has_negatives = !neg;
				}

				if (nest_level != 0) {
					INSIST(dacl->length < dacl->alloc);
					de->type = dns_aclelementtype_nestedacl;
					de->negative = !neg;
				} else {
					continue;
				}
			} else if (strcasecmp(name, "localhost") == 0) {
				INSIST(dacl->length < dacl->alloc);
				de->type = dns_aclelementtype_localhost;
				de->negative = neg;
			} else if (strcasecmp(name, "localnets") == 0) {
				INSIST(dacl->length < dacl->alloc);
				de->type = dns_aclelementtype_localnets;
				de->negative = neg;
			} else {
				if (inneracl != NULL) {
					dns_acl_detach(&inneracl);
				}
				/*
				 * This call should just find the cached
				 * of the named acl.
				 */
				CHECK(convert_named_acl(ce, cctx, ctx, mctx,
							new_nest_level,
							&inneracl));

				goto nested_acl;
			}
		} else {
			cfg_obj_log(ce, ISC_LOG_WARNING,
				    "address match list contains "
				    "unsupported element type");
			CLEANUP(ISC_R_FAILURE);
		}

		/*
		 * This should only be reached for localhost, localnets
		 * and keyname elements, and nested ACLs if nest_level is
		 * nonzero.
		 */
		if (de->nestedacl != NULL &&
		    de->type != dns_aclelementtype_nestedacl)
		{
			dns_acl_detach(&de->nestedacl);
		}

		dns_acl_node_count(dacl)++;
		de->node_num = dns_acl_node_count(dacl);

		dacl->length++;
		de++;
		INSIST(dacl->length <= dacl->alloc);
	}

	dns_acl_attach(dacl, target);
	result = ISC_R_SUCCESS;

cleanup:
	if (inneracl != NULL) {
		dns_acl_detach(&inneracl);
	}
	dns_acl_detach(&dacl);
	return result;
}
