/*
 * Copyright (C) 2004, 2007, 2008  Internet Systems Consortium, Inc. ("ISC")
 * Copyright (C) 1999-2003  Internet Software Consortium.
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 */

/* $Id: rootns.c,v 1.20.2.3.2.11 2008/02/05 23:45:38 tbox Exp $ */

#include <config.h>

#include <isc/buffer.h>
#include <isc/string.h>		/* Required for HP/UX (and others?) */
#include <isc/util.h>

#include <dns/callbacks.h>
#include <dns/db.h>
#include <dns/dbiterator.h>
#include <dns/log.h>
#include <dns/fixedname.h>
#include <dns/master.h>
#include <dns/rdata.h>
#include <dns/rdatasetiter.h>
#include <dns/rdataset.h>
#include <dns/rdatastruct.h>
#include <dns/result.h>
#include <dns/rootns.h>

static char root_ns[] =
";\n"
"; Internet Root Nameservers\n"
";\n"
"$TTL 518400\n"
".                       518400  IN      NS      A.ROOT-SERVERS.NET.\n"
".                       518400  IN      NS      B.ROOT-SERVERS.NET.\n"
".                       518400  IN      NS      C.ROOT-SERVERS.NET.\n"
".                       518400  IN      NS      D.ROOT-SERVERS.NET.\n"
".                       518400  IN      NS      E.ROOT-SERVERS.NET.\n"
".                       518400  IN      NS      F.ROOT-SERVERS.NET.\n"
".                       518400  IN      NS      G.ROOT-SERVERS.NET.\n"
".                       518400  IN      NS      H.ROOT-SERVERS.NET.\n"
".                       518400  IN      NS      I.ROOT-SERVERS.NET.\n"
".                       518400  IN      NS      J.ROOT-SERVERS.NET.\n"
".                       518400  IN      NS      K.ROOT-SERVERS.NET.\n"
".                       518400  IN      NS      L.ROOT-SERVERS.NET.\n"
".                       518400  IN      NS      M.ROOT-SERVERS.NET.\n"
"A.ROOT-SERVERS.NET.     3600000 IN      A       198.41.0.4\n"
"A.ROOT-SERVERS.NET.     3600000 IN      AAAA    2001:503:BA3E::2:30\n"
"B.ROOT-SERVERS.NET.     3600000 IN      A       192.228.79.201\n"
"C.ROOT-SERVERS.NET.     3600000 IN      A       192.33.4.12\n"
"D.ROOT-SERVERS.NET.     3600000 IN      A       128.8.10.90\n"
"E.ROOT-SERVERS.NET.     3600000 IN      A       192.203.230.10\n"
"F.ROOT-SERVERS.NET.     3600000 IN      A       192.5.5.241\n"
"F.ROOT-SERVERS.NET.     3600000 IN      AAAA    2001:500:2F::F\n"
"G.ROOT-SERVERS.NET.     3600000 IN      A       192.112.36.4\n"
"H.ROOT-SERVERS.NET.     3600000 IN      A       128.63.2.53\n"
"H.ROOT-SERVERS.NET.     3600000 IN      AAAA    2001:500:1::803F:235\n"
"I.ROOT-SERVERS.NET.     3600000 IN      A       192.36.148.17\n"
"J.ROOT-SERVERS.NET.     3600000 IN      A       192.58.128.30\n"
"J.ROOT-SERVERS.NET.     3600000 IN      AAAA    2001:503:C27::2:30\n"
"K.ROOT-SERVERS.NET.     3600000 IN      A       193.0.14.129\n"
"K.ROOT-SERVERS.NET.     3600000 IN      AAAA    2001:7FD::1\n"
"L.ROOT-SERVERS.NET.     3600000 IN      A       199.7.83.42\n"
"M.ROOT-SERVERS.NET.     3600000 IN      A       202.12.27.33\n"
"M.ROOT-SERVERS.NET.     3600000 IN      AAAA    2001:DC3::35\n";

static isc_result_t
in_rootns(dns_rdataset_t *rootns, dns_name_t *name) {
	isc_result_t result;
	dns_rdata_t rdata = DNS_RDATA_INIT;
	dns_rdata_ns_t ns;

	if (!dns_rdataset_isassociated(rootns))
		return (ISC_R_NOTFOUND);

	result = dns_rdataset_first(rootns);
	while (result == ISC_R_SUCCESS) {
		dns_rdataset_current(rootns, &rdata);
		result = dns_rdata_tostruct(&rdata, &ns, NULL);
		if (result != ISC_R_SUCCESS)
			return (result);
		if (dns_name_compare(name, &ns.name) == 0)
			return (ISC_R_SUCCESS);
		result = dns_rdataset_next(rootns);
	}
	if (result == ISC_R_NOMORE)
		result = ISC_R_NOTFOUND;
	return (result);
}

static isc_result_t
check_node(dns_rdataset_t *rootns, dns_name_t *name,
	   dns_rdatasetiter_t *rdsiter) {
	isc_result_t result;
	dns_rdataset_t rdataset;

	dns_rdataset_init(&rdataset);
	result = dns_rdatasetiter_first(rdsiter);
	while (result == ISC_R_SUCCESS) {
		dns_rdatasetiter_current(rdsiter, &rdataset);
		switch (rdataset.type) {
		case dns_rdatatype_a:
		case dns_rdatatype_aaaa:
			result = in_rootns(rootns, name);
			if (result != ISC_R_SUCCESS)
				goto cleanup;
			break;
		case dns_rdatatype_ns:
			if (dns_name_compare(name, dns_rootname) == 0)
				break;
			/*FALLTHROUGH*/
		default:
			result = ISC_R_FAILURE;
			goto cleanup;
		}
		dns_rdataset_disassociate(&rdataset);
		result = dns_rdatasetiter_next(rdsiter);
	}
	if (result == ISC_R_NOMORE)
		result = ISC_R_SUCCESS;
 cleanup:
	if (dns_rdataset_isassociated(&rdataset))
		dns_rdataset_disassociate(&rdataset);
	return (result);
}

static isc_result_t
check_hints(dns_db_t *db) {
	isc_result_t result;
	dns_rdataset_t rootns;
	dns_dbiterator_t *dbiter = NULL;
	dns_dbnode_t *node = NULL;
	isc_stdtime_t now;
	dns_fixedname_t fixname;
	dns_name_t *name;
	dns_rdatasetiter_t *rdsiter = NULL;

	isc_stdtime_get(&now);

	dns_fixedname_init(&fixname);
	name = dns_fixedname_name(&fixname);

	dns_rdataset_init(&rootns);
	(void)dns_db_find(db, dns_rootname, NULL, dns_rdatatype_ns, 0,
			  now, NULL, name, &rootns, NULL);
	result = dns_db_createiterator(db, ISC_FALSE, &dbiter);
	if (result != ISC_R_SUCCESS)
		goto cleanup;
	result = dns_dbiterator_first(dbiter);
	while (result == ISC_R_SUCCESS) {
		result = dns_dbiterator_current(dbiter, &node, name);
		if (result != ISC_R_SUCCESS)
			goto cleanup;
		result = dns_db_allrdatasets(db, node, NULL, now, &rdsiter);
		if (result != ISC_R_SUCCESS)
			goto cleanup;
		result = check_node(&rootns, name, rdsiter);
		if (result != ISC_R_SUCCESS)
			goto cleanup;
		dns_rdatasetiter_destroy(&rdsiter);
		dns_db_detachnode(db, &node);
		result = dns_dbiterator_next(dbiter);
	}
	if (result == ISC_R_NOMORE)
		result = ISC_R_SUCCESS;

 cleanup:
	if (dns_rdataset_isassociated(&rootns))
		dns_rdataset_disassociate(&rootns);
	if (rdsiter != NULL)
		dns_rdatasetiter_destroy(&rdsiter);
	if (node != NULL)
		dns_db_detachnode(db, &node);
	if (dbiter != NULL)
		dns_dbiterator_destroy(&dbiter);
	return (result);
}

isc_result_t
dns_rootns_create(isc_mem_t *mctx, dns_rdataclass_t rdclass,
		  const char *filename, dns_db_t **target)
{
	isc_result_t result, eresult;
	isc_buffer_t source;
	size_t len;
	dns_rdatacallbacks_t callbacks;
	dns_db_t *db = NULL;

	REQUIRE(target != NULL && *target == NULL);

	result = dns_db_create(mctx, "rbt", dns_rootname, dns_dbtype_zone,
			       rdclass, 0, NULL, &db);
	if (result != ISC_R_SUCCESS)
		return (result);

	dns_rdatacallbacks_init(&callbacks);

	len = strlen(root_ns);
	isc_buffer_init(&source, root_ns, len);
	isc_buffer_add(&source, len);

	result = dns_db_beginload(db, &callbacks.add,
				  &callbacks.add_private);
	if (result != ISC_R_SUCCESS)
		return (result);
	if (filename != NULL) {
		/*
		 * Load the hints from the specified filename.
		 */
		result = dns_master_loadfile(filename, &db->origin,
					     &db->origin, db->rdclass,
					     DNS_MASTER_HINT,
					     &callbacks, db->mctx);
	} else if (rdclass == dns_rdataclass_in) {
		/*
		 * Default to using the Internet root servers.
		 */
		result = dns_master_loadbuffer(&source, &db->origin,
					       &db->origin, db->rdclass,
					       DNS_MASTER_HINT,
					       &callbacks, db->mctx);
	} else
		result = ISC_R_NOTFOUND;
	eresult = dns_db_endload(db, &callbacks.add_private);
	if (result == ISC_R_SUCCESS || result == DNS_R_SEENINCLUDE)
		result = eresult;
	if (result != ISC_R_SUCCESS && result != DNS_R_SEENINCLUDE)
		goto db_detach;
	if (check_hints(db) != ISC_R_SUCCESS)
		isc_log_write(dns_lctx, DNS_LOGCATEGORY_GENERAL,
			      DNS_LOGMODULE_HINTS, ISC_LOG_WARNING,
			      "extra data in root hints '%s'",
			      (filename != NULL) ? filename : "<BUILT-IN>");
	*target = db;
	return (ISC_R_SUCCESS);

 db_detach:
	dns_db_detach(&db);

	return (result);
}
