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[netbsd-mini2440.git] / external / bsd / bind / dist / bin / named / query.c

/*      $NetBSD$        */

/*
 * Copyright (C) 2004-2009  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: query.c,v 1.335 2009/11/28 15:57:36 vjs Exp */

/*! \file */

#include <config.h>

#include <string.h>

#include <isc/hex.h>
#include <isc/mem.h>
#include <isc/stats.h>
#include <isc/util.h>

#include <dns/adb.h>
#include <dns/byaddr.h>
#include <dns/db.h>
#ifdef DLZ
#include <dns/dlz.h>
#endif
#include <dns/dnssec.h>
#include <dns/events.h>
#include <dns/message.h>
#include <dns/ncache.h>
#include <dns/nsec3.h>
#include <dns/order.h>
#include <dns/rdata.h>
#include <dns/rdataclass.h>
#include <dns/rdatalist.h>
#include <dns/rdataset.h>
#include <dns/rdatasetiter.h>
#include <dns/rdatastruct.h>
#include <dns/rdatatype.h>
#include <dns/resolver.h>
#include <dns/result.h>
#include <dns/stats.h>
#include <dns/tkey.h>
#include <dns/view.h>
#include <dns/zone.h>
#include <dns/zt.h>

#include <named/client.h>
#include <named/log.h>
#include <named/server.h>
#include <named/sortlist.h>
#include <named/xfrout.h>

/*% Partial answer? */
#define PARTIALANSWER(c)        (((c)->query.attributes & \
                                  NS_QUERYATTR_PARTIALANSWER) != 0)
/*% Use Cache? */
#define USECACHE(c)             (((c)->query.attributes & \
                                  NS_QUERYATTR_CACHEOK) != 0)
/*% Recursion OK? */
#define RECURSIONOK(c)          (((c)->query.attributes & \
                                  NS_QUERYATTR_RECURSIONOK) != 0)
/*% Recursing? */
#define RECURSING(c)            (((c)->query.attributes & \
                                  NS_QUERYATTR_RECURSING) != 0)
/*% Cache glue ok? */
#define CACHEGLUEOK(c)          (((c)->query.attributes & \
                                  NS_QUERYATTR_CACHEGLUEOK) != 0)
/*% Want Recursion? */
#define WANTRECURSION(c)        (((c)->query.attributes & \
                                  NS_QUERYATTR_WANTRECURSION) != 0)
/*% Want DNSSEC? */
#define WANTDNSSEC(c)           (((c)->attributes & \
                                  NS_CLIENTATTR_WANTDNSSEC) != 0)
/*% No authority? */
#define NOAUTHORITY(c)          (((c)->query.attributes & \
                                  NS_QUERYATTR_NOAUTHORITY) != 0)
/*% No additional? */
#define NOADDITIONAL(c)         (((c)->query.attributes & \
                                  NS_QUERYATTR_NOADDITIONAL) != 0)
/*% Secure? */
#define SECURE(c)               (((c)->query.attributes & \
                                  NS_QUERYATTR_SECURE) != 0)

/*% No QNAME Proof? */
#define NOQNAME(r)              (((r)->attributes & \
                                  DNS_RDATASETATTR_NOQNAME) != 0)

#if 0
#define CTRACE(m)       isc_log_write(ns_g_lctx, \
                                      NS_LOGCATEGORY_CLIENT, \
                                      NS_LOGMODULE_QUERY, \
                                      ISC_LOG_DEBUG(3), \
                                      "client %p: %s", client, (m))
#define QTRACE(m)       isc_log_write(ns_g_lctx, \
                                      NS_LOGCATEGORY_GENERAL, \
                                      NS_LOGMODULE_QUERY, \
                                      ISC_LOG_DEBUG(3), \
                                      "query %p: %s", query, (m))
#else
#define CTRACE(m) ((void)m)
#define QTRACE(m) ((void)m)
#endif

#define DNS_GETDB_NOEXACT 0x01U
#define DNS_GETDB_NOLOG 0x02U
#define DNS_GETDB_PARTIAL 0x04U

#define PENDINGOK(x)    (((x) & DNS_DBFIND_PENDINGOK) != 0)

typedef struct client_additionalctx {
        ns_client_t *client;
        dns_rdataset_t *rdataset;
} client_additionalctx_t;

static isc_result_t
query_find(ns_client_t *client, dns_fetchevent_t *event, dns_rdatatype_t qtype);

static isc_boolean_t
validate(ns_client_t *client, dns_db_t *db, dns_name_t *name,
         dns_rdataset_t *rdataset, dns_rdataset_t *sigrdataset);

static void
query_findclosestnsec3(dns_name_t *qname, dns_db_t *db,
                       dns_dbversion_t *version, ns_client_t *client,
                       dns_rdataset_t *rdataset, dns_rdataset_t *sigrdataset,
                       dns_name_t *fname, isc_boolean_t exact,
                       dns_name_t *found);

static inline void
log_queryerror(ns_client_t *client, isc_result_t result, int line, int level);

/*%
 * Increment query statistics counters.
 */
static inline void
inc_stats(ns_client_t *client, isc_statscounter_t counter) {
        dns_zone_t *zone = client->query.authzone;

        isc_stats_increment(ns_g_server->nsstats, counter);

        if (zone != NULL) {
                isc_stats_t *zonestats = dns_zone_getrequeststats(zone);
                if (zonestats != NULL)
                        isc_stats_increment(zonestats, counter);
        }
}

static void
query_send(ns_client_t *client) {
        isc_statscounter_t counter;
        if ((client->message->flags & DNS_MESSAGEFLAG_AA) == 0)
                inc_stats(client, dns_nsstatscounter_nonauthans);
        else
                inc_stats(client, dns_nsstatscounter_authans);
        if (client->message->rcode == dns_rcode_noerror) {
                if (ISC_LIST_EMPTY(client->message->sections[DNS_SECTION_ANSWER])) {
                        if (client->query.isreferral) {
                                counter = dns_nsstatscounter_referral;
                        } else {
                                counter = dns_nsstatscounter_nxrrset;
                        }
                } else {
                        counter = dns_nsstatscounter_success;
                }
        } else if (client->message->rcode == dns_rcode_nxdomain) {
                counter = dns_nsstatscounter_nxdomain;
        } else {
                /* We end up here in case of YXDOMAIN, and maybe others */
                counter = dns_nsstatscounter_failure;
        }
        inc_stats(client, counter);
        ns_client_send(client);
}

static void
query_error(ns_client_t *client, isc_result_t result, int line) {
        int loglevel = ISC_LOG_DEBUG(3);

        switch (result) {
        case DNS_R_SERVFAIL:
                loglevel = ISC_LOG_DEBUG(1);
                inc_stats(client, dns_nsstatscounter_servfail);
                break;
        case DNS_R_FORMERR:
                inc_stats(client, dns_nsstatscounter_formerr);
                break;
        default:
                inc_stats(client, dns_nsstatscounter_failure);
                break;
        }

        log_queryerror(client, result, line, loglevel);

        ns_client_error(client, result);
}

static void
query_next(ns_client_t *client, isc_result_t result) {
        if (result == DNS_R_DUPLICATE)
                inc_stats(client, dns_nsstatscounter_duplicate);
        else if (result == DNS_R_DROP)
                inc_stats(client, dns_nsstatscounter_dropped);
        else
                inc_stats(client, dns_nsstatscounter_failure);
        ns_client_next(client, result);
}

static inline void
query_freefreeversions(ns_client_t *client, isc_boolean_t everything) {
        ns_dbversion_t *dbversion, *dbversion_next;
        unsigned int i;

        for (dbversion = ISC_LIST_HEAD(client->query.freeversions), i = 0;
             dbversion != NULL;
             dbversion = dbversion_next, i++)
        {
                dbversion_next = ISC_LIST_NEXT(dbversion, link);
                /*
                 * If we're not freeing everything, we keep the first three
                 * dbversions structures around.
                 */
                if (i > 3 || everything) {
                        ISC_LIST_UNLINK(client->query.freeversions, dbversion,
                                        link);
                        isc_mem_put(client->mctx, dbversion,
                                    sizeof(*dbversion));
                }
        }
}

void
ns_query_cancel(ns_client_t *client) {
        LOCK(&client->query.fetchlock);
        if (client->query.fetch != NULL) {
                dns_resolver_cancelfetch(client->query.fetch);

                client->query.fetch = NULL;
        }
        UNLOCK(&client->query.fetchlock);
}

static inline void
query_reset(ns_client_t *client, isc_boolean_t everything) {
        isc_buffer_t *dbuf, *dbuf_next;
        ns_dbversion_t *dbversion, *dbversion_next;

        /*%
         * Reset the query state of a client to its default state.
         */

        /*
         * Cancel the fetch if it's running.
         */
        ns_query_cancel(client);

        /*
         * Cleanup any active versions.
         */
        for (dbversion = ISC_LIST_HEAD(client->query.activeversions);
             dbversion != NULL;
             dbversion = dbversion_next) {
                dbversion_next = ISC_LIST_NEXT(dbversion, link);
                dns_db_closeversion(dbversion->db, &dbversion->version,
                                    ISC_FALSE);
                dns_db_detach(&dbversion->db);
                ISC_LIST_INITANDAPPEND(client->query.freeversions,
                                      dbversion, link);
        }
        ISC_LIST_INIT(client->query.activeversions);

        if (client->query.authdb != NULL)
                dns_db_detach(&client->query.authdb);
        if (client->query.authzone != NULL)
                dns_zone_detach(&client->query.authzone);

        query_freefreeversions(client, everything);

        for (dbuf = ISC_LIST_HEAD(client->query.namebufs);
             dbuf != NULL;
             dbuf = dbuf_next) {
                dbuf_next = ISC_LIST_NEXT(dbuf, link);
                if (dbuf_next != NULL || everything) {
                        ISC_LIST_UNLINK(client->query.namebufs, dbuf, link);
                        isc_buffer_free(&dbuf);
                }
        }

        if (client->query.restarts > 0) {
                /*
                 * client->query.qname was dynamically allocated.
                 */
                dns_message_puttempname(client->message,
                                        &client->query.qname);
        }
        client->query.qname = NULL;
        client->query.attributes = (NS_QUERYATTR_RECURSIONOK |
                                    NS_QUERYATTR_CACHEOK |
                                    NS_QUERYATTR_SECURE);
        client->query.restarts = 0;
        client->query.timerset = ISC_FALSE;
        client->query.origqname = NULL;
        client->query.qname = NULL;
        client->query.dboptions = 0;
        client->query.fetchoptions = 0;
        client->query.gluedb = NULL;
        client->query.authdbset = ISC_FALSE;
        client->query.isreferral = ISC_FALSE;
}

static void
query_next_callback(ns_client_t *client) {
        query_reset(client, ISC_FALSE);
}

void
ns_query_free(ns_client_t *client) {
        query_reset(client, ISC_TRUE);
}

static inline isc_result_t
query_newnamebuf(ns_client_t *client) {
        isc_buffer_t *dbuf;
        isc_result_t result;

        CTRACE("query_newnamebuf");
        /*%
         * Allocate a name buffer.
         */

        dbuf = NULL;
        result = isc_buffer_allocate(client->mctx, &dbuf, 1024);
        if (result != ISC_R_SUCCESS) {
                CTRACE("query_newnamebuf: isc_buffer_allocate failed: done");
                return (result);
        }
        ISC_LIST_APPEND(client->query.namebufs, dbuf, link);

        CTRACE("query_newnamebuf: done");
        return (ISC_R_SUCCESS);
}

static inline isc_buffer_t *
query_getnamebuf(ns_client_t *client) {
        isc_buffer_t *dbuf;
        isc_result_t result;
        isc_region_t r;

        CTRACE("query_getnamebuf");
        /*%
         * Return a name buffer with space for a maximal name, allocating
         * a new one if necessary.
         */

        if (ISC_LIST_EMPTY(client->query.namebufs)) {
                result = query_newnamebuf(client);
                if (result != ISC_R_SUCCESS) {
                    CTRACE("query_getnamebuf: query_newnamebuf failed: done");
                        return (NULL);
                }
        }

        dbuf = ISC_LIST_TAIL(client->query.namebufs);
        INSIST(dbuf != NULL);
        isc_buffer_availableregion(dbuf, &r);
        if (r.length < 255) {
                result = query_newnamebuf(client);
                if (result != ISC_R_SUCCESS) {
                    CTRACE("query_getnamebuf: query_newnamebuf failed: done");
                        return (NULL);

                }
                dbuf = ISC_LIST_TAIL(client->query.namebufs);
                isc_buffer_availableregion(dbuf, &r);
                INSIST(r.length >= 255);
        }
        CTRACE("query_getnamebuf: done");
        return (dbuf);
}

static inline void
query_keepname(ns_client_t *client, dns_name_t *name, isc_buffer_t *dbuf) {
        isc_region_t r;

        CTRACE("query_keepname");
        /*%
         * 'name' is using space in 'dbuf', but 'dbuf' has not yet been
         * adjusted to take account of that.  We do the adjustment.
         */

        REQUIRE((client->query.attributes & NS_QUERYATTR_NAMEBUFUSED) != 0);

        dns_name_toregion(name, &r);
        isc_buffer_add(dbuf, r.length);
        dns_name_setbuffer(name, NULL);
        client->query.attributes &= ~NS_QUERYATTR_NAMEBUFUSED;
}

static inline void
query_releasename(ns_client_t *client, dns_name_t **namep) {
        dns_name_t *name = *namep;

        /*%
         * 'name' is no longer needed.  Return it to our pool of temporary
         * names.  If it is using a name buffer, relinquish its exclusive
         * rights on the buffer.
         */

        CTRACE("query_releasename");
        if (dns_name_hasbuffer(name)) {
                INSIST((client->query.attributes & NS_QUERYATTR_NAMEBUFUSED)
                       != 0);
                client->query.attributes &= ~NS_QUERYATTR_NAMEBUFUSED;
        }
        dns_message_puttempname(client->message, namep);
        CTRACE("query_releasename: done");
}

static inline dns_name_t *
query_newname(ns_client_t *client, isc_buffer_t *dbuf,
              isc_buffer_t *nbuf)
{
        dns_name_t *name;
        isc_region_t r;
        isc_result_t result;

        REQUIRE((client->query.attributes & NS_QUERYATTR_NAMEBUFUSED) == 0);

        CTRACE("query_newname");
        name = NULL;
        result = dns_message_gettempname(client->message, &name);
        if (result != ISC_R_SUCCESS) {
                CTRACE("query_newname: dns_message_gettempname failed: done");
                return (NULL);
        }
        isc_buffer_availableregion(dbuf, &r);
        isc_buffer_init(nbuf, r.base, r.length);
        dns_name_init(name, NULL);
        dns_name_setbuffer(name, nbuf);
        client->query.attributes |= NS_QUERYATTR_NAMEBUFUSED;

        CTRACE("query_newname: done");
        return (name);
}

static inline dns_rdataset_t *
query_newrdataset(ns_client_t *client) {
        dns_rdataset_t *rdataset;
        isc_result_t result;

        CTRACE("query_newrdataset");
        rdataset = NULL;
        result = dns_message_gettemprdataset(client->message, &rdataset);
        if (result != ISC_R_SUCCESS) {
          CTRACE("query_newrdataset: "
                 "dns_message_gettemprdataset failed: done");
                return (NULL);
        }
        dns_rdataset_init(rdataset);

        CTRACE("query_newrdataset: done");
        return (rdataset);
}

static inline void
query_putrdataset(ns_client_t *client, dns_rdataset_t **rdatasetp) {
        dns_rdataset_t *rdataset = *rdatasetp;

        CTRACE("query_putrdataset");
        if (rdataset != NULL) {
                if (dns_rdataset_isassociated(rdataset))
                        dns_rdataset_disassociate(rdataset);
                dns_message_puttemprdataset(client->message, rdatasetp);
        }
        CTRACE("query_putrdataset: done");
}


static inline isc_result_t
query_newdbversion(ns_client_t *client, unsigned int n) {
        unsigned int i;
        ns_dbversion_t *dbversion;

        for (i = 0; i < n; i++) {
                dbversion = isc_mem_get(client->mctx, sizeof(*dbversion));
                if (dbversion != NULL) {
                        dbversion->db = NULL;
                        dbversion->version = NULL;
                        ISC_LIST_INITANDAPPEND(client->query.freeversions,
                                              dbversion, link);
                } else {
                        /*
                         * We only return ISC_R_NOMEMORY if we couldn't
                         * allocate anything.
                         */
                        if (i == 0)
                                return (ISC_R_NOMEMORY);
                        else
                                return (ISC_R_SUCCESS);
                }
        }

        return (ISC_R_SUCCESS);
}

static inline ns_dbversion_t *
query_getdbversion(ns_client_t *client) {
        isc_result_t result;
        ns_dbversion_t *dbversion;

        if (ISC_LIST_EMPTY(client->query.freeversions)) {
                result = query_newdbversion(client, 1);
                if (result != ISC_R_SUCCESS)
                        return (NULL);
        }
        dbversion = ISC_LIST_HEAD(client->query.freeversions);
        INSIST(dbversion != NULL);
        ISC_LIST_UNLINK(client->query.freeversions, dbversion, link);

        return (dbversion);
}

isc_result_t
ns_query_init(ns_client_t *client) {
        isc_result_t result;

        ISC_LIST_INIT(client->query.namebufs);
        ISC_LIST_INIT(client->query.activeversions);
        ISC_LIST_INIT(client->query.freeversions);
        client->query.restarts = 0;
        client->query.timerset = ISC_FALSE;
        client->query.qname = NULL;
        result = isc_mutex_init(&client->query.fetchlock);
        if (result != ISC_R_SUCCESS)
                return (result);
        client->query.fetch = NULL;
        client->query.authdb = NULL;
        client->query.authzone = NULL;
        client->query.authdbset = ISC_FALSE;
        client->query.isreferral = ISC_FALSE;
        query_reset(client, ISC_FALSE);
        result = query_newdbversion(client, 3);
        if (result != ISC_R_SUCCESS) {
                DESTROYLOCK(&client->query.fetchlock);
                return (result);
        }
        result = query_newnamebuf(client);
        if (result != ISC_R_SUCCESS)
                query_freefreeversions(client, ISC_TRUE);

        return (result);
}

static inline ns_dbversion_t *
query_findversion(ns_client_t *client, dns_db_t *db,
                  isc_boolean_t *newzonep)
{
        ns_dbversion_t *dbversion;

        /*%
         * We may already have done a query related to this
         * database.  If so, we must be sure to make subsequent
         * queries from the same version.
         */
        for (dbversion = ISC_LIST_HEAD(client->query.activeversions);
             dbversion != NULL;
             dbversion = ISC_LIST_NEXT(dbversion, link)) {
                if (dbversion->db == db)
                        break;
        }

        if (dbversion == NULL) {
                /*
                 * This is a new zone for this query.  Add it to
                 * the active list.
                 */
                dbversion = query_getdbversion(client);
                if (dbversion == NULL)
                        return (NULL);
                dns_db_attach(db, &dbversion->db);
                dns_db_currentversion(db, &dbversion->version);
                dbversion->queryok = ISC_FALSE;
                ISC_LIST_APPEND(client->query.activeversions,
                                dbversion, link);
                *newzonep = ISC_TRUE;
        } else
                *newzonep = ISC_FALSE;

        return (dbversion);
}

static inline isc_result_t
query_validatezonedb(ns_client_t *client, dns_name_t *name,
                     dns_rdatatype_t qtype, unsigned int options,
                     dns_zone_t *zone, dns_db_t *db,
                     dns_dbversion_t **versionp)
{
        isc_result_t result;
        isc_boolean_t check_acl, new_zone;
        dns_acl_t *queryacl;
        ns_dbversion_t *dbversion;

        REQUIRE(zone != NULL);
        REQUIRE(db != NULL);

        /*
         * This limits our searching to the zone where the first name
         * (the query target) was looked for.  This prevents following
         * CNAMES or DNAMES into other zones and prevents returning
         * additional data from other zones.
         */
        if (!client->view->additionalfromauth &&
            client->query.authdbset &&
            db != client->query.authdb)
                goto refuse;

        /*
         * If the zone has an ACL, we'll check it, otherwise
         * we use the view's "allow-query" ACL.  Each ACL is only checked
         * once per query.
         *
         * Also, get the database version to use.
         */

        check_acl = ISC_TRUE;   /* Keep compiler happy. */
        queryacl = NULL;

        /*
         * Get the current version of this database.
         */
        dbversion = query_findversion(client, db, &new_zone);
        if (dbversion == NULL) {
                result = DNS_R_SERVFAIL;
                goto fail;
        }
        if (new_zone) {
                check_acl = ISC_TRUE;
        } else if (!dbversion->queryok) {
                goto refuse;
        } else {
                check_acl = ISC_FALSE;
        }

        queryacl = dns_zone_getqueryacl(zone);
        if (queryacl == NULL) {
                queryacl = client->view->queryacl;
                if ((client->query.attributes &
                     NS_QUERYATTR_QUERYOKVALID) != 0) {
                        /*
                         * We've evaluated the view's queryacl already.  If
                         * NS_QUERYATTR_QUERYOK is set, then the client is
                         * allowed to make queries, otherwise the query should
                         * be refused.
                         */
                        check_acl = ISC_FALSE;
                        if ((client->query.attributes &
                             NS_QUERYATTR_QUERYOK) == 0)
                                goto refuse;
                } else {
                        /*
                         * We haven't evaluated the view's queryacl yet.
                         */
                        check_acl = ISC_TRUE;
                }
        }

        if (check_acl) {
                isc_boolean_t log = ISC_TF((options & DNS_GETDB_NOLOG) == 0);

                result = ns_client_checkaclsilent(client, NULL, queryacl,
                                                  ISC_TRUE);
                if (log) {
                        char msg[NS_CLIENT_ACLMSGSIZE("query")];
                        if (result == ISC_R_SUCCESS) {
                                if (isc_log_wouldlog(ns_g_lctx,
                                                     ISC_LOG_DEBUG(3)))
                                {
                                        ns_client_aclmsg("query", name, qtype,
                                                         client->view->rdclass,
                                                         msg, sizeof(msg));
                                        ns_client_log(client,
                                                      DNS_LOGCATEGORY_SECURITY,
                                                      NS_LOGMODULE_QUERY,
                                                      ISC_LOG_DEBUG(3),
                                                      "%s approved", msg);
                                }
                        } else {
                                ns_client_aclmsg("query", name, qtype,
                                                 client->view->rdclass,
                                                 msg, sizeof(msg));
                                ns_client_log(client, DNS_LOGCATEGORY_SECURITY,
                                              NS_LOGMODULE_QUERY, ISC_LOG_INFO,
                                              "%s denied", msg);
                        }
                }

                if (queryacl == client->view->queryacl) {
                        if (result == ISC_R_SUCCESS) {
                                /*
                                 * We were allowed by the default
                                 * "allow-query" ACL.  Remember this so we
                                 * don't have to check again.
                                 */
                                client->query.attributes |=
                                        NS_QUERYATTR_QUERYOK;
                        }
                        /*
                         * We've now evaluated the view's query ACL, and
                         * the NS_QUERYATTR_QUERYOK attribute is now valid.
                         */
                        client->query.attributes |= NS_QUERYATTR_QUERYOKVALID;
                }

                if (result != ISC_R_SUCCESS)
                        goto refuse;
        }

        /* Approved. */

        /*
         * Remember the result of the ACL check so we
         * don't have to check again.
         */
        dbversion->queryok = ISC_TRUE;

        /* Transfer ownership, if necessary. */
        if (versionp != NULL)
                *versionp = dbversion->version;

        return (ISC_R_SUCCESS);

 refuse:
        return (DNS_R_REFUSED);

 fail:
        return (result);
}

static inline isc_result_t
query_getzonedb(ns_client_t *client, dns_name_t *name, dns_rdatatype_t qtype,
                unsigned int options, dns_zone_t **zonep, dns_db_t **dbp,
                dns_dbversion_t **versionp)
{
        isc_result_t result;
        unsigned int ztoptions;
        dns_zone_t *zone = NULL;
        dns_db_t *db = NULL;
        isc_boolean_t partial = ISC_FALSE;

        REQUIRE(zonep != NULL && *zonep == NULL);
        REQUIRE(dbp != NULL && *dbp == NULL);

        /*%
         * Find a zone database to answer the query.
         */
        ztoptions = ((options & DNS_GETDB_NOEXACT) != 0) ?
                DNS_ZTFIND_NOEXACT : 0;

        result = dns_zt_find(client->view->zonetable, name, ztoptions, NULL,
                             &zone);
        if (result == DNS_R_PARTIALMATCH)
                partial = ISC_TRUE;
        if (result == ISC_R_SUCCESS || result == DNS_R_PARTIALMATCH)
                result = dns_zone_getdb(zone, &db);

        if (result != ISC_R_SUCCESS)
                goto fail;

        result = query_validatezonedb(client, name, qtype, options, zone, db,
                                      versionp);

        if (result != ISC_R_SUCCESS)
                goto fail;

        /* Transfer ownership. */
        *zonep = zone;
        *dbp = db;

        if (partial && (options & DNS_GETDB_PARTIAL) != 0)
                return (DNS_R_PARTIALMATCH);
        return (ISC_R_SUCCESS);

 fail:
        if (zone != NULL)
                dns_zone_detach(&zone);
        if (db != NULL)
                dns_db_detach(&db);

        return (result);
}

static inline isc_result_t
query_getcachedb(ns_client_t *client, dns_name_t *name, dns_rdatatype_t qtype,
                 dns_db_t **dbp, unsigned int options)
{
        isc_result_t result;
        isc_boolean_t check_acl;
        dns_db_t *db = NULL;

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

        /*%
         * Find a cache database to answer the query.
         * This may fail with DNS_R_REFUSED if the client
         * is not allowed to use the cache.
         */

        if (!USECACHE(client))
                return (DNS_R_REFUSED);
        dns_db_attach(client->view->cachedb, &db);

        if ((client->query.attributes &
             NS_QUERYATTR_QUERYOKVALID) != 0) {
                /*
                 * We've evaluated the view's queryacl already.  If
                 * NS_QUERYATTR_QUERYOK is set, then the client is
                 * allowed to make queries, otherwise the query should
                 * be refused.
                 */
                check_acl = ISC_FALSE;
                if ((client->query.attributes &
                     NS_QUERYATTR_QUERYOK) == 0)
                        goto refuse;
        } else {
                /*
                 * We haven't evaluated the view's queryacl yet.
                 */
                check_acl = ISC_TRUE;
        }

        if (check_acl) {
                isc_boolean_t log = ISC_TF((options & DNS_GETDB_NOLOG) == 0);
                char msg[NS_CLIENT_ACLMSGSIZE("query (cache)")];

                result = ns_client_checkaclsilent(client, NULL,
                                                  client->view->queryacl,
                                                  ISC_TRUE);
                if (result == ISC_R_SUCCESS) {
                        /*
                         * We were allowed by the default
                         * "allow-query" ACL.  Remember this so we
                         * don't have to check again.
                         */
                        client->query.attributes |=
                                NS_QUERYATTR_QUERYOK;
                        if (log && isc_log_wouldlog(ns_g_lctx,
                                                     ISC_LOG_DEBUG(3)))
                        {
                                ns_client_aclmsg("query (cache)", name, qtype,
                                                 client->view->rdclass,
                                                 msg, sizeof(msg));
                                ns_client_log(client,
                                              DNS_LOGCATEGORY_SECURITY,
                                              NS_LOGMODULE_QUERY,
                                              ISC_LOG_DEBUG(3),
                                              "%s approved", msg);
                        }
                } else if (log) {
                        ns_client_aclmsg("query (cache)", name, qtype,
                                         client->view->rdclass, msg,
                                         sizeof(msg));
                        ns_client_log(client, DNS_LOGCATEGORY_SECURITY,
                                      NS_LOGMODULE_QUERY, ISC_LOG_INFO,
                                      "%s denied", msg);
                }
                /*
                 * We've now evaluated the view's query ACL, and
                 * the NS_QUERYATTR_QUERYOK attribute is now valid.
                 */
                client->query.attributes |= NS_QUERYATTR_QUERYOKVALID;

                if (result != ISC_R_SUCCESS)
                        goto refuse;
        }

        /* Approved. */

        /* Transfer ownership. */
        *dbp = db;

        return (ISC_R_SUCCESS);

 refuse:
        result = DNS_R_REFUSED;

        if (db != NULL)
                dns_db_detach(&db);

        return (result);
}


static inline isc_result_t
query_getdb(ns_client_t *client, dns_name_t *name, dns_rdatatype_t qtype,
            unsigned int options, dns_zone_t **zonep, dns_db_t **dbp,
            dns_dbversion_t **versionp, isc_boolean_t *is_zonep)
{
        isc_result_t result;

#ifdef DLZ
        isc_result_t tresult;
        unsigned int namelabels;
        unsigned int zonelabels;
        dns_zone_t *zone = NULL;
        dns_db_t *tdbp;

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

        tdbp = NULL;

        /* Calculate how many labels are in name. */
        namelabels = dns_name_countlabels(name);
        zonelabels = 0;

        /* Try to find name in bind's standard database. */
        result = query_getzonedb(client, name, qtype, options, &zone,
                                 dbp, versionp);

        /* See how many labels are in the zone's name.    */
        if (result == ISC_R_SUCCESS && zone != NULL)
                zonelabels = dns_name_countlabels(dns_zone_getorigin(zone));
        /*
         * If # zone labels < # name labels, try to find an even better match
         * Only try if a DLZ driver is loaded for this view
         */
        if (zonelabels < namelabels && client->view->dlzdatabase != NULL) {
                tresult = dns_dlzfindzone(client->view, name,
                                          zonelabels, &tdbp);
                 /* If we successful, we found a better match. */
                if (tresult == ISC_R_SUCCESS) {
                        /*
                         * If the previous search returned a zone, detach it.
                         */
                        if (zone != NULL)
                                dns_zone_detach(&zone);

                        /*
                         * If the previous search returned a database,
                         * detach it.
                         */
                        if (*dbp != NULL)
                                dns_db_detach(dbp);

                        /*
                         * If the previous search returned a version, clear it.
                         */
                        *versionp = NULL;

                        /*
                         * Get our database version.
                         */
                        dns_db_currentversion(tdbp, versionp);

                        /*
                         * Be sure to return our database.
                         */
                        *dbp = tdbp;

                        /*
                         * We return a null zone, No stats for DLZ zones.
                         */
                        zone = NULL;
                        result = tresult;
                }
        }
#else
        result = query_getzonedb(client, name, qtype, options,
                                 zonep, dbp, versionp);
#endif

        /* If successful, Transfer ownership of zone. */
        if (result == ISC_R_SUCCESS) {
#ifdef DLZ
                *zonep = zone;
#endif
                /*
                 * If neither attempt above succeeded, return the cache instead
                 */
                *is_zonep = ISC_TRUE;
        } else if (result == ISC_R_NOTFOUND) {
                result = query_getcachedb(client, name, qtype, dbp, options);
                *is_zonep = ISC_FALSE;
        }
        return (result);
}

static inline isc_boolean_t
query_isduplicate(ns_client_t *client, dns_name_t *name,
                  dns_rdatatype_t type, dns_name_t **mnamep)
{
        dns_section_t section;
        dns_name_t *mname = NULL;
        isc_result_t result;

        CTRACE("query_isduplicate");

        for (section = DNS_SECTION_ANSWER;
             section <= DNS_SECTION_ADDITIONAL;
             section++) {
                result = dns_message_findname(client->message, section,
                                              name, type, 0, &mname, NULL);
                if (result == ISC_R_SUCCESS) {
                        /*
                         * We've already got this RRset in the response.
                         */
                        CTRACE("query_isduplicate: true: done");
                        return (ISC_TRUE);
                } else if (result == DNS_R_NXRRSET) {
                        /*
                         * The name exists, but the rdataset does not.
                         */
                        if (section == DNS_SECTION_ADDITIONAL)
                                break;
                } else
                        RUNTIME_CHECK(result == DNS_R_NXDOMAIN);
                mname = NULL;
        }

        /*
         * If the dns_name_t we're looking up is already in the message,
         * we don't want to trigger the caller's name replacement logic.
         */
        if (name == mname)
                mname = NULL;

        *mnamep = mname;

        CTRACE("query_isduplicate: false: done");
        return (ISC_FALSE);
}

static isc_result_t
query_addadditional(void *arg, dns_name_t *name, dns_rdatatype_t qtype) {
        ns_client_t *client = arg;
        isc_result_t result, eresult;
        dns_dbnode_t *node;
        dns_db_t *db;
        dns_name_t *fname, *mname;
        dns_rdataset_t *rdataset, *sigrdataset, *trdataset;
        isc_buffer_t *dbuf;
        isc_buffer_t b;
        dns_dbversion_t *version;
        isc_boolean_t added_something, need_addname;
        dns_zone_t *zone;
        dns_rdatatype_t type;

        REQUIRE(NS_CLIENT_VALID(client));
        REQUIRE(qtype != dns_rdatatype_any);

        if (!WANTDNSSEC(client) && dns_rdatatype_isdnssec(qtype))
                return (ISC_R_SUCCESS);

        CTRACE("query_addadditional");

        /*
         * Initialization.
         */
        eresult = ISC_R_SUCCESS;
        fname = NULL;
        rdataset = NULL;
        sigrdataset = NULL;
        trdataset = NULL;
        db = NULL;
        version = NULL;
        node = NULL;
        added_something = ISC_FALSE;
        need_addname = ISC_FALSE;
        zone = NULL;

        /*
         * We treat type A additional section processing as if it
         * were "any address type" additional section processing.
         * To avoid multiple lookups, we do an 'any' database
         * lookup and iterate over the node.
         */
        if (qtype == dns_rdatatype_a)
                type = dns_rdatatype_any;
        else
                type = qtype;

        /*
         * Get some resources.
         */
        dbuf = query_getnamebuf(client);
        if (dbuf == NULL)
                goto cleanup;
        fname = query_newname(client, dbuf, &b);
        rdataset = query_newrdataset(client);
        if (fname == NULL || rdataset == NULL)
                goto cleanup;
        if (WANTDNSSEC(client)) {
                sigrdataset = query_newrdataset(client);
                if (sigrdataset == NULL)
                        goto cleanup;
        }

        /*
         * Look for a zone database that might contain authoritative
         * additional data.
         */
        result = query_getzonedb(client, name, qtype, DNS_GETDB_NOLOG,
                                 &zone, &db, &version);
        if (result != ISC_R_SUCCESS)
                goto try_cache;

        CTRACE("query_addadditional: db_find");

        /*
         * Since we are looking for authoritative data, we do not set
         * the GLUEOK flag.  Glue will be looked for later, but not
         * necessarily in the same database.
         */
        node = NULL;
        result = dns_db_find(db, name, version, type, client->query.dboptions,
                             client->now, &node, fname, rdataset,
                             sigrdataset);
        if (result == ISC_R_SUCCESS) {
                if (sigrdataset != NULL && !dns_db_issecure(db) &&
                    dns_rdataset_isassociated(sigrdataset))
                        dns_rdataset_disassociate(sigrdataset);
                goto found;
        }

        if (dns_rdataset_isassociated(rdataset))
                dns_rdataset_disassociate(rdataset);
        if (sigrdataset != NULL && dns_rdataset_isassociated(sigrdataset))
                dns_rdataset_disassociate(sigrdataset);
        if (node != NULL)
                dns_db_detachnode(db, &node);
        version = NULL;
        dns_db_detach(&db);

        /*
         * No authoritative data was found.  The cache is our next best bet.
         */

 try_cache:
        result = query_getcachedb(client, name, qtype, &db, DNS_GETDB_NOLOG);
        if (result != ISC_R_SUCCESS)
                /*
                 * Most likely the client isn't allowed to query the cache.
                 */
                goto try_glue;
        /*
         * Attempt to validate glue.
         */
        if (sigrdataset == NULL) {
                sigrdataset = query_newrdataset(client);
                if (sigrdataset == NULL)
                        goto cleanup;
        }
        result = dns_db_find(db, name, version, type,
                             client->query.dboptions |
                             DNS_DBFIND_GLUEOK | DNS_DBFIND_ADDITIONALOK,
                             client->now, &node, fname, rdataset,
                             sigrdataset);
        if (result == DNS_R_GLUE &&
            validate(client, db, fname, rdataset, sigrdataset))
                result = ISC_R_SUCCESS;
        if (!WANTDNSSEC(client))
                query_putrdataset(client, &sigrdataset);
        if (result == ISC_R_SUCCESS)
                goto found;

        if (dns_rdataset_isassociated(rdataset))
                dns_rdataset_disassociate(rdataset);
        if (sigrdataset != NULL && dns_rdataset_isassociated(sigrdataset))
                dns_rdataset_disassociate(sigrdataset);
        if (node != NULL)
                dns_db_detachnode(db, &node);
        dns_db_detach(&db);

 try_glue:
        /*
         * No cached data was found.  Glue is our last chance.
         * RFC1035 sayeth:
         *
         *      NS records cause both the usual additional section
         *      processing to locate a type A record, and, when used
         *      in a referral, a special search of the zone in which
         *      they reside for glue information.
         *
         * This is the "special search".  Note that we must search
         * the zone where the NS record resides, not the zone it
         * points to, and that we only do the search in the delegation
         * case (identified by client->query.gluedb being set).
         */

        if (client->query.gluedb == NULL)
                goto cleanup;

        /*
         * Don't poison caches using the bailiwick protection model.
         */
        if (!dns_name_issubdomain(name, dns_db_origin(client->query.gluedb)))
                goto cleanup;

        dns_db_attach(client->query.gluedb, &db);
        result = dns_db_find(db, name, version, type,
                             client->query.dboptions | DNS_DBFIND_GLUEOK,
                             client->now, &node, fname, rdataset,
                             sigrdataset);
        if (!(result == ISC_R_SUCCESS ||
              result == DNS_R_ZONECUT ||
              result == DNS_R_GLUE))
                goto cleanup;

 found:
        /*
         * We have found a potential additional data rdataset, or
         * at least a node to iterate over.
         */
        query_keepname(client, fname, dbuf);

        /*
         * If we have an rdataset, add it to the additional data
         * section.
         */
        mname = NULL;
        if (dns_rdataset_isassociated(rdataset) &&
            !query_isduplicate(client, fname, type, &mname)) {
                if (mname != NULL) {
                        query_releasename(client, &fname);
                        fname = mname;
                } else
                        need_addname = ISC_TRUE;
                ISC_LIST_APPEND(fname->list, rdataset, link);
                trdataset = rdataset;
                rdataset = NULL;
                added_something = ISC_TRUE;
                /*
                 * Note: we only add SIGs if we've added the type they cover,
                 * so we do not need to check if the SIG rdataset is already
                 * in the response.
                 */
                if (sigrdataset != NULL &&
                    dns_rdataset_isassociated(sigrdataset))
                {
                        ISC_LIST_APPEND(fname->list, sigrdataset, link);
                        sigrdataset = NULL;
                }
        }

        if (qtype == dns_rdatatype_a) {
                /*
                 * We now go looking for A and AAAA records, along with
                 * their signatures.
                 *
                 * XXXRTH  This code could be more efficient.
                 */
                if (rdataset != NULL) {
                        if (dns_rdataset_isassociated(rdataset))
                                dns_rdataset_disassociate(rdataset);
                } else {
                        rdataset = query_newrdataset(client);
                        if (rdataset == NULL)
                                goto addname;
                }
                if (sigrdataset != NULL) {
                        if (dns_rdataset_isassociated(sigrdataset))
                                dns_rdataset_disassociate(sigrdataset);
                } else if (WANTDNSSEC(client)) {
                        sigrdataset = query_newrdataset(client);
                        if (sigrdataset == NULL)
                                goto addname;
                }
                result = dns_db_findrdataset(db, node, version,
                                             dns_rdatatype_a, 0,
                                             client->now, rdataset,
                                             sigrdataset);
                if (result == DNS_R_NCACHENXDOMAIN)
                        goto addname;
                if (result == DNS_R_NCACHENXRRSET) {
                        dns_rdataset_disassociate(rdataset);
                        /*
                         * Negative cache entries don't have sigrdatasets.
                         */
                        INSIST(sigrdataset == NULL ||
                               ! dns_rdataset_isassociated(sigrdataset));
                }
                if (result == ISC_R_SUCCESS) {
                        mname = NULL;
                        if (!query_isduplicate(client, fname,
                                               dns_rdatatype_a, &mname)) {
                                if (mname != NULL) {
                                        query_releasename(client, &fname);
                                        fname = mname;
                                } else
                                        need_addname = ISC_TRUE;
                                ISC_LIST_APPEND(fname->list, rdataset, link);
                                added_something = ISC_TRUE;
                                if (sigrdataset != NULL &&
                                    dns_rdataset_isassociated(sigrdataset))
                                {
                                        ISC_LIST_APPEND(fname->list,
                                                        sigrdataset, link);
                                        sigrdataset =
                                                query_newrdataset(client);
                                }
                                rdataset = query_newrdataset(client);
                                if (rdataset == NULL)
                                        goto addname;
                                if (WANTDNSSEC(client) && sigrdataset == NULL)
                                        goto addname;
                        } else {
                                dns_rdataset_disassociate(rdataset);
                                if (sigrdataset != NULL &&
                                    dns_rdataset_isassociated(sigrdataset))
                                        dns_rdataset_disassociate(sigrdataset);
                        }
                }
                result = dns_db_findrdataset(db, node, version,
                                             dns_rdatatype_aaaa, 0,
                                             client->now, rdataset,
                                             sigrdataset);
                if (result == DNS_R_NCACHENXDOMAIN)
                        goto addname;
                if (result == DNS_R_NCACHENXRRSET) {
                        dns_rdataset_disassociate(rdataset);
                        INSIST(sigrdataset == NULL ||
                               ! dns_rdataset_isassociated(sigrdataset));
                }
                if (result == ISC_R_SUCCESS) {
                        mname = NULL;
                        if (!query_isduplicate(client, fname,
                                               dns_rdatatype_aaaa, &mname)) {
                                if (mname != NULL) {
                                        query_releasename(client, &fname);
                                        fname = mname;
                                } else
                                        need_addname = ISC_TRUE;
                                ISC_LIST_APPEND(fname->list, rdataset, link);
                                added_something = ISC_TRUE;
                                if (sigrdataset != NULL &&
                                    dns_rdataset_isassociated(sigrdataset))
                                {
                                        ISC_LIST_APPEND(fname->list,
                                                        sigrdataset, link);
                                        sigrdataset = NULL;
                                }
                                rdataset = NULL;
                        }
                }
        }

 addname:
        CTRACE("query_addadditional: addname");
        /*
         * If we haven't added anything, then we're done.
         */
        if (!added_something)
                goto cleanup;

        /*
         * We may have added our rdatasets to an existing name, if so, then
         * need_addname will be ISC_FALSE.  Whether we used an existing name
         * or a new one, we must set fname to NULL to prevent cleanup.
         */
        if (need_addname)
                dns_message_addname(client->message, fname,
                                    DNS_SECTION_ADDITIONAL);
        fname = NULL;

        /*
         * In a few cases, we want to add additional data for additional
         * data.  It's simpler to just deal with special cases here than
         * to try to create a general purpose mechanism and allow the
         * rdata implementations to do it themselves.
         *
         * This involves recursion, but the depth is limited.  The
         * most complex case is adding a SRV rdataset, which involves
         * recursing to add address records, which in turn can cause
         * recursion to add KEYs.
         */
        if (type == dns_rdatatype_srv && trdataset != NULL) {
                /*
                 * If we're adding SRV records to the additional data
                 * section, it's helpful if we add the SRV additional data
                 * as well.
                 */
                eresult = dns_rdataset_additionaldata(trdataset,
                                                      query_addadditional,
                                                      client);
        }

 cleanup:
        CTRACE("query_addadditional: cleanup");
        query_putrdataset(client, &rdataset);
        if (sigrdataset != NULL)
                query_putrdataset(client, &sigrdataset);
        if (fname != NULL)
                query_releasename(client, &fname);
        if (node != NULL)
                dns_db_detachnode(db, &node);
        if (db != NULL)
                dns_db_detach(&db);
        if (zone != NULL)
                dns_zone_detach(&zone);

        CTRACE("query_addadditional: done");
        return (eresult);
}

static inline void
query_discardcache(ns_client_t *client, dns_rdataset_t *rdataset_base,
                   dns_rdatasetadditional_t additionaltype,
                   dns_rdatatype_t type, dns_zone_t **zonep, dns_db_t **dbp,
                   dns_dbversion_t **versionp, dns_dbnode_t **nodep,
                   dns_name_t *fname)
{
        dns_rdataset_t *rdataset;

        while  ((rdataset = ISC_LIST_HEAD(fname->list)) != NULL) {
                ISC_LIST_UNLINK(fname->list, rdataset, link);
                query_putrdataset(client, &rdataset);
        }
        if (*versionp != NULL)
                dns_db_closeversion(*dbp, versionp, ISC_FALSE);
        if (*nodep != NULL)
                dns_db_detachnode(*dbp, nodep);
        if (*dbp != NULL)
                dns_db_detach(dbp);
        if (*zonep != NULL)
                dns_zone_detach(zonep);
        (void)dns_rdataset_putadditional(client->view->acache, rdataset_base,
                                         additionaltype, type);
}

static inline isc_result_t
query_iscachevalid(dns_zone_t *zone, dns_db_t *db, dns_db_t *db0,
                   dns_dbversion_t *version)
{
        isc_result_t result = ISC_R_SUCCESS;
        dns_dbversion_t *version_current = NULL;
        dns_db_t *db_current = db0;

        if (db_current == NULL) {
                result = dns_zone_getdb(zone, &db_current);
                if (result != ISC_R_SUCCESS)
                        return (result);
        }
        dns_db_currentversion(db_current, &version_current);
        if (db_current != db || version_current != version) {
                result = ISC_R_FAILURE;
                goto cleanup;
        }

 cleanup:
        dns_db_closeversion(db_current, &version_current, ISC_FALSE);
        if (db0 == NULL && db_current != NULL)
                dns_db_detach(&db_current);

        return (result);
}

static isc_result_t
query_addadditional2(void *arg, dns_name_t *name, dns_rdatatype_t qtype) {
        client_additionalctx_t *additionalctx = arg;
        dns_rdataset_t *rdataset_base;
        ns_client_t *client;
        isc_result_t result, eresult;
        dns_dbnode_t *node, *cnode;
        dns_db_t *db, *cdb;
        dns_name_t *fname, *mname0, cfname;
        dns_rdataset_t *rdataset, *sigrdataset;
        dns_rdataset_t *crdataset, *crdataset_next;
        isc_buffer_t *dbuf;
        isc_buffer_t b;
        dns_dbversion_t *version, *cversion;
        isc_boolean_t added_something, need_addname, needadditionalcache;
        isc_boolean_t need_sigrrset;
        dns_zone_t *zone;
        dns_rdatatype_t type;
        dns_rdatasetadditional_t additionaltype;

        if (qtype != dns_rdatatype_a) {
                /*
                 * This function is optimized for "address" types.  For other
                 * types, use a generic routine.
                 * XXX: ideally, this function should be generic enough.
                 */
                return (query_addadditional(additionalctx->client,
                                            name, qtype));
        }

        /*
         * Initialization.
         */
        rdataset_base = additionalctx->rdataset;
        client = additionalctx->client;
        REQUIRE(NS_CLIENT_VALID(client));
        eresult = ISC_R_SUCCESS;
        fname = NULL;
        rdataset = NULL;
        sigrdataset = NULL;
        db = NULL;
        cdb = NULL;
        version = NULL;
        cversion = NULL;
        node = NULL;
        cnode = NULL;
        added_something = ISC_FALSE;
        need_addname = ISC_FALSE;
        zone = NULL;
        needadditionalcache = ISC_FALSE;
        additionaltype = dns_rdatasetadditional_fromauth;
        dns_name_init(&cfname, NULL);

        CTRACE("query_addadditional2");

        /*
         * We treat type A additional section processing as if it
         * were "any address type" additional section processing.
         * To avoid multiple lookups, we do an 'any' database
         * lookup and iterate over the node.
         * XXXJT: this approach can cause a suboptimal result when the cache
         * DB only has partial address types and the glue DB has remaining
         * ones.
         */
        type = dns_rdatatype_any;

        /*
         * Get some resources.
         */
        dbuf = query_getnamebuf(client);
        if (dbuf == NULL)
                goto cleanup;
        fname = query_newname(client, dbuf, &b);
        if (fname == NULL)
                goto cleanup;
        dns_name_setbuffer(&cfname, &b); /* share the buffer */

        /* Check additional cache */
        result = dns_rdataset_getadditional(rdataset_base, additionaltype,
                                            type, client->view->acache, &zone,
                                            &cdb, &cversion, &cnode, &cfname,
                                            client->message, client->now);
        if (result != ISC_R_SUCCESS)
                goto findauthdb;
        if (zone == NULL) {
                CTRACE("query_addadditional2: auth zone not found");
                goto try_cache;
        }

        /* Is the cached DB up-to-date? */
        result = query_iscachevalid(zone, cdb, NULL, cversion);
        if (result != ISC_R_SUCCESS) {
                CTRACE("query_addadditional2: old auth additional cache");
                query_discardcache(client, rdataset_base, additionaltype,
                                   type, &zone, &cdb, &cversion, &cnode,
                                   &cfname);
                goto findauthdb;
        }

        if (cnode == NULL) {
                /*
                 * We have a negative cache.  We don't have to check the zone
                 * ACL, since the result (not using this zone) would be same
                 * regardless of the result.
                 */
                CTRACE("query_addadditional2: negative auth additional cache");
                dns_db_closeversion(cdb, &cversion, ISC_FALSE);
                dns_db_detach(&cdb);
                dns_zone_detach(&zone);
                goto try_cache;
        }

        result = query_validatezonedb(client, name, qtype, DNS_GETDB_NOLOG,
                                      zone, cdb, NULL);
        if (result != ISC_R_SUCCESS) {
                query_discardcache(client, rdataset_base, additionaltype,
                                   type, &zone, &cdb, &cversion, &cnode,
                                   &cfname);
                goto try_cache;
        }

        /* We've got an active cache. */
        CTRACE("query_addadditional2: auth additional cache");
        dns_db_closeversion(cdb, &cversion, ISC_FALSE);
        db = cdb;
        node = cnode;
        dns_name_clone(&cfname, fname);
        query_keepname(client, fname, dbuf);
        goto foundcache;

        /*
         * Look for a zone database that might contain authoritative
         * additional data.
         */
 findauthdb:
        result = query_getzonedb(client, name, qtype, DNS_GETDB_NOLOG,
                                 &zone, &db, &version);
        if (result != ISC_R_SUCCESS) {
                /* Cache the negative result */
                (void)dns_rdataset_setadditional(rdataset_base, additionaltype,
                                                 type, client->view->acache,
                                                 NULL, NULL, NULL, NULL,
                                                 NULL);
                goto try_cache;
        }

        CTRACE("query_addadditional2: db_find");

        /*
         * Since we are looking for authoritative data, we do not set
         * the GLUEOK flag.  Glue will be looked for later, but not
         * necessarily in the same database.
         */
        node = NULL;
        result = dns_db_find(db, name, version, type, client->query.dboptions,
                             client->now, &node, fname, NULL, NULL);
        if (result == ISC_R_SUCCESS)
                goto found;

        /* Cache the negative result */
        (void)dns_rdataset_setadditional(rdataset_base, additionaltype,
                                         type, client->view->acache, zone, db,
                                         version, NULL, fname);

        if (node != NULL)
                dns_db_detachnode(db, &node);
        version = NULL;
        dns_db_detach(&db);

        /*
         * No authoritative data was found.  The cache is our next best bet.
         */

 try_cache:
        additionaltype = dns_rdatasetadditional_fromcache;
        result = query_getcachedb(client, name, qtype, &db, DNS_GETDB_NOLOG);
        if (result != ISC_R_SUCCESS)
                /*
                 * Most likely the client isn't allowed to query the cache.
                 */
                goto try_glue;

        result = dns_db_find(db, name, version, type,
                             client->query.dboptions |
                             DNS_DBFIND_GLUEOK | DNS_DBFIND_ADDITIONALOK,
                             client->now, &node, fname, NULL, NULL);
        if (result == ISC_R_SUCCESS)
                goto found;

        if (node != NULL)
                dns_db_detachnode(db, &node);
        dns_db_detach(&db);

 try_glue:
        /*
         * No cached data was found.  Glue is our last chance.
         * RFC1035 sayeth:
         *
         *      NS records cause both the usual additional section
         *      processing to locate a type A record, and, when used
         *      in a referral, a special search of the zone in which
         *      they reside for glue information.
         *
         * This is the "special search".  Note that we must search
         * the zone where the NS record resides, not the zone it
         * points to, and that we only do the search in the delegation
         * case (identified by client->query.gluedb being set).
         */
        if (client->query.gluedb == NULL)
                goto cleanup;

        /*
         * Don't poison caches using the bailiwick protection model.
         */
        if (!dns_name_issubdomain(name, dns_db_origin(client->query.gluedb)))
                goto cleanup;

        /* Check additional cache */
        additionaltype = dns_rdatasetadditional_fromglue;
        result = dns_rdataset_getadditional(rdataset_base, additionaltype,
                                            type, client->view->acache, NULL,
                                            &cdb, &cversion, &cnode, &cfname,
                                            client->message, client->now);
        if (result != ISC_R_SUCCESS)
                goto findglue;

        result = query_iscachevalid(zone, cdb, client->query.gluedb, cversion);
        if (result != ISC_R_SUCCESS) {
                CTRACE("query_addadditional2: old glue additional cache");
                query_discardcache(client, rdataset_base, additionaltype,
                                   type, &zone, &cdb, &cversion, &cnode,
                                   &cfname);
                goto findglue;
        }

        if (cnode == NULL) {
                /* We have a negative cache. */
                CTRACE("query_addadditional2: negative glue additional cache");
                dns_db_closeversion(cdb, &cversion, ISC_FALSE);
                dns_db_detach(&cdb);
                goto cleanup;
        }

        /* Cache hit. */
        CTRACE("query_addadditional2: glue additional cache");
        dns_db_closeversion(cdb, &cversion, ISC_FALSE);
        db = cdb;
        node = cnode;
        dns_name_clone(&cfname, fname);
        query_keepname(client, fname, dbuf);
        goto foundcache;

 findglue:
        dns_db_attach(client->query.gluedb, &db);
        result = dns_db_find(db, name, version, type,
                             client->query.dboptions | DNS_DBFIND_GLUEOK,
                             client->now, &node, fname, NULL, NULL);
        if (!(result == ISC_R_SUCCESS ||
              result == DNS_R_ZONECUT ||
              result == DNS_R_GLUE)) {
                /* cache the negative result */
                (void)dns_rdataset_setadditional(rdataset_base, additionaltype,
                                                 type, client->view->acache,
                                                 NULL, db, version, NULL,
                                                 fname);
                goto cleanup;
        }

 found:
        /*
         * We have found a DB node to iterate over from a DB.
         * We are going to look for address RRsets (i.e., A and AAAA) in the DB
         * node we've just found.  We'll then store the complete information
         * in the additional data cache.
         */
        dns_name_clone(fname, &cfname);
        query_keepname(client, fname, dbuf);
        needadditionalcache = ISC_TRUE;

        rdataset = query_newrdataset(client);
        if (rdataset == NULL)
                goto cleanup;

        sigrdataset = query_newrdataset(client);
        if (sigrdataset == NULL)
                goto cleanup;

        /*
         * Find A RRset with sig RRset.  Even if we don't find a sig RRset
         * for a client using DNSSEC, we'll continue the process to make a
         * complete list to be cached.  However, we need to cancel the
         * caching when something unexpected happens, in order to avoid
         * caching incomplete information.
         */
        result = dns_db_findrdataset(db, node, version, dns_rdatatype_a, 0,
                                     client->now, rdataset, sigrdataset);
        /*
         * If we can't promote glue/pending from the cache to secure
         * then drop it.
         */
        if (result == ISC_R_SUCCESS &&
            additionaltype == dns_rdatasetadditional_fromcache &&
            (DNS_TRUST_PENDING(rdataset->trust) ||
             DNS_TRUST_GLUE(rdataset->trust)) &&
            !validate(client, db, fname, rdataset, sigrdataset)) {
                dns_rdataset_disassociate(rdataset);
                if (dns_rdataset_isassociated(sigrdataset))
                        dns_rdataset_disassociate(sigrdataset);
                result = ISC_R_NOTFOUND;
        }
        if (result == DNS_R_NCACHENXDOMAIN)
                goto setcache;
        if (result == DNS_R_NCACHENXRRSET) {
                dns_rdataset_disassociate(rdataset);
                /*
                 * Negative cache entries don't have sigrdatasets.
                 */
                INSIST(! dns_rdataset_isassociated(sigrdataset));
        }
        if (result == ISC_R_SUCCESS) {
                /* Remember the result as a cache */
                ISC_LIST_APPEND(cfname.list, rdataset, link);
                if (dns_rdataset_isassociated(sigrdataset)) {
                        ISC_LIST_APPEND(cfname.list, sigrdataset, link);
                        sigrdataset = query_newrdataset(client);
                }
                rdataset = query_newrdataset(client);
                if (sigrdataset == NULL || rdataset == NULL) {
                        /* do not cache incomplete information */
                        goto foundcache;
                }
        }

        /* Find AAAA RRset with sig RRset */
        result = dns_db_findrdataset(db, node, version, dns_rdatatype_aaaa,
                                     0, client->now, rdataset, sigrdataset);
        /*
         * If we can't promote glue/pending from the cache to secure
         * then drop it.
         */
        if (result == ISC_R_SUCCESS &&
            additionaltype == dns_rdatasetadditional_fromcache &&
            (DNS_TRUST_PENDING(rdataset->trust) ||
             DNS_TRUST_GLUE(rdataset->trust)) &&
            !validate(client, db, fname, rdataset, sigrdataset)) {
                dns_rdataset_disassociate(rdataset);
                if (dns_rdataset_isassociated(sigrdataset))
                        dns_rdataset_disassociate(sigrdataset);
                result = ISC_R_NOTFOUND;
        }
        if (result == ISC_R_SUCCESS) {
                ISC_LIST_APPEND(cfname.list, rdataset, link);
                rdataset = NULL;
                if (dns_rdataset_isassociated(sigrdataset)) {
                        ISC_LIST_APPEND(cfname.list, sigrdataset, link);
                        sigrdataset = NULL;
                }
        }

 setcache:
        /*
         * Set the new result in the cache if required.  We do not support
         * caching additional data from a cache DB.
         */
        if (needadditionalcache == ISC_TRUE &&
            (additionaltype == dns_rdatasetadditional_fromauth ||
             additionaltype == dns_rdatasetadditional_fromglue)) {
                (void)dns_rdataset_setadditional(rdataset_base, additionaltype,
                                                 type, client->view->acache,
                                                 zone, db, version, node,
                                                 &cfname);
        }

 foundcache:
        need_sigrrset = ISC_FALSE;
        mname0 = NULL;
        for (crdataset = ISC_LIST_HEAD(cfname.list);
             crdataset != NULL;
             crdataset = crdataset_next) {
                dns_name_t *mname;

                crdataset_next = ISC_LIST_NEXT(crdataset, link);

                mname = NULL;
                if (crdataset->type == dns_rdatatype_a ||
                    crdataset->type == dns_rdatatype_aaaa) {
                        if (!query_isduplicate(client, fname, crdataset->type,
                                               &mname)) {
                                if (mname != NULL) {
                                        /*
                                         * A different type of this name is
                                         * already stored in the additional
                                         * section.  We'll reuse the name.
                                         * Note that this should happen at most
                                         * once.  Otherwise, fname->link could
                                         * leak below.
                                         */
                                        INSIST(mname0 == NULL);

                                        query_releasename(client, &fname);
                                        fname = mname;
                                        mname0 = mname;
                                } else
                                        need_addname = ISC_TRUE;
                                ISC_LIST_UNLINK(cfname.list, crdataset, link);
                                ISC_LIST_APPEND(fname->list, crdataset, link);
                                added_something = ISC_TRUE;
                                need_sigrrset = ISC_TRUE;
                        } else
                                need_sigrrset = ISC_FALSE;
                } else if (crdataset->type == dns_rdatatype_rrsig &&
                           need_sigrrset && WANTDNSSEC(client)) {
                        ISC_LIST_UNLINK(cfname.list, crdataset, link);
                        ISC_LIST_APPEND(fname->list, crdataset, link);
                        added_something = ISC_TRUE; /* just in case */
                        need_sigrrset = ISC_FALSE;
                }
        }

        CTRACE("query_addadditional2: addname");

        /*
         * If we haven't added anything, then we're done.
         */
        if (!added_something)
                goto cleanup;

        /*
         * We may have added our rdatasets to an existing name, if so, then
         * need_addname will be ISC_FALSE.  Whether we used an existing name
         * or a new one, we must set fname to NULL to prevent cleanup.
         */
        if (need_addname)
                dns_message_addname(client->message, fname,
                                    DNS_SECTION_ADDITIONAL);
        fname = NULL;

 cleanup:
        CTRACE("query_addadditional2: cleanup");

        if (rdataset != NULL)
                query_putrdataset(client, &rdataset);
        if (sigrdataset != NULL)
                query_putrdataset(client, &sigrdataset);
        while  ((crdataset = ISC_LIST_HEAD(cfname.list)) != NULL) {
                ISC_LIST_UNLINK(cfname.list, crdataset, link);
                query_putrdataset(client, &crdataset);
        }
        if (fname != NULL)
                query_releasename(client, &fname);
        if (node != NULL)
                dns_db_detachnode(db, &node);
        if (db != NULL)
                dns_db_detach(&db);
        if (zone != NULL)
                dns_zone_detach(&zone);

        CTRACE("query_addadditional2: done");
        return (eresult);
}

static inline void
query_addrdataset(ns_client_t *client, dns_name_t *fname,
                  dns_rdataset_t *rdataset)
{
        client_additionalctx_t additionalctx;

        /*
         * Add 'rdataset' and any pertinent additional data to
         * 'fname', a name in the response message for 'client'.
         */

        CTRACE("query_addrdataset");

        ISC_LIST_APPEND(fname->list, rdataset, link);

        if (client->view->order != NULL)
                rdataset->attributes |= dns_order_find(client->view->order,
                                                       fname, rdataset->type,
                                                       rdataset->rdclass);
        rdataset->attributes |= DNS_RDATASETATTR_LOADORDER;

        if (NOADDITIONAL(client))
                return;

        /*
         * Add additional data.
         *
         * We don't care if dns_rdataset_additionaldata() fails.
         */
        additionalctx.client = client;
        additionalctx.rdataset = rdataset;
        (void)dns_rdataset_additionaldata(rdataset, query_addadditional2,
                                          &additionalctx);
        CTRACE("query_addrdataset: done");
}

static void
query_addrrset(ns_client_t *client, dns_name_t **namep,
               dns_rdataset_t **rdatasetp, dns_rdataset_t **sigrdatasetp,
               isc_buffer_t *dbuf, dns_section_t section)
{
        dns_name_t *name, *mname;
        dns_rdataset_t *rdataset, *mrdataset, *sigrdataset;
        isc_result_t result;

        /*%
         * To the current response for 'client', add the answer RRset
         * '*rdatasetp' and an optional signature set '*sigrdatasetp', with
         * owner name '*namep', to section 'section', unless they are
         * already there.  Also add any pertinent additional data.
         *
         * If 'dbuf' is not NULL, then '*namep' is the name whose data is
         * stored in 'dbuf'.  In this case, query_addrrset() guarantees that
         * when it returns the name will either have been kept or released.
         */
        CTRACE("query_addrrset");
        name = *namep;
        rdataset = *rdatasetp;
        if (sigrdatasetp != NULL)
                sigrdataset = *sigrdatasetp;
        else
                sigrdataset = NULL;
        mname = NULL;
        mrdataset = NULL;
        result = dns_message_findname(client->message, section,
                                      name, rdataset->type, rdataset->covers,
                                      &mname, &mrdataset);
        if (result == ISC_R_SUCCESS) {
                /*
                 * We've already got an RRset of the given name and type.
                 * There's nothing else to do;
                 */
                CTRACE("query_addrrset: dns_message_findname succeeded: done");
                if (dbuf != NULL)
                        query_releasename(client, namep);
                return;
        } else if (result == DNS_R_NXDOMAIN) {
                /*
                 * The name doesn't exist.
                 */
                if (dbuf != NULL)
                        query_keepname(client, name, dbuf);
                dns_message_addname(client->message, name, section);
                *namep = NULL;
                mname = name;
        } else {
                RUNTIME_CHECK(result == DNS_R_NXRRSET);
                if (dbuf != NULL)
                        query_releasename(client, namep);
        }

        if (rdataset->trust != dns_trust_secure &&
            (section == DNS_SECTION_ANSWER ||
             section == DNS_SECTION_AUTHORITY))
                client->query.attributes &= ~NS_QUERYATTR_SECURE;
        /*
         * Note: we only add SIGs if we've added the type they cover, so
         * we do not need to check if the SIG rdataset is already in the
         * response.
         */
        query_addrdataset(client, mname, rdataset);
        *rdatasetp = NULL;
        if (sigrdataset != NULL && dns_rdataset_isassociated(sigrdataset)) {
                /*
                 * We have a signature.  Add it to the response.
                 */
                ISC_LIST_APPEND(mname->list, sigrdataset, link);
                *sigrdatasetp = NULL;
        }
        CTRACE("query_addrrset: done");
}

static inline isc_result_t
query_addsoa(ns_client_t *client, dns_db_t *db, dns_dbversion_t *version,
             isc_boolean_t zero_ttl)
{
        dns_name_t *name;
        dns_dbnode_t *node;
        isc_result_t result, eresult;
        dns_rdataset_t *rdataset = NULL, *sigrdataset = NULL;
        dns_rdataset_t **sigrdatasetp = NULL;

        CTRACE("query_addsoa");
        /*
         * Initialization.
         */
        eresult = ISC_R_SUCCESS;
        name = NULL;
        rdataset = NULL;
        node = NULL;

        /*
         * Get resources and make 'name' be the database origin.
         */
        result = dns_message_gettempname(client->message, &name);
        if (result != ISC_R_SUCCESS)
                return (result);
        dns_name_init(name, NULL);
        dns_name_clone(dns_db_origin(db), name);
        rdataset = query_newrdataset(client);
        if (rdataset == NULL) {
                eresult = DNS_R_SERVFAIL;
                goto cleanup;
        }
        if (WANTDNSSEC(client) && dns_db_issecure(db)) {
                sigrdataset = query_newrdataset(client);
                if (sigrdataset == NULL) {
                        eresult = DNS_R_SERVFAIL;
                        goto cleanup;
                }
        }

        /*
         * Find the SOA.
         */
        result = dns_db_getoriginnode(db, &node);
        if (result == ISC_R_SUCCESS) {
                result = dns_db_findrdataset(db, node, version,
                                             dns_rdatatype_soa,
                                             0, client->now, rdataset,
                                             sigrdataset);
        } else {
                dns_fixedname_t foundname;
                dns_name_t *fname;

                dns_fixedname_init(&foundname);
                fname = dns_fixedname_name(&foundname);

                result = dns_db_find(db, name, version, dns_rdatatype_soa,
                                     client->query.dboptions, 0, &node,
                                     fname, rdataset, sigrdataset);
        }
        if (result != ISC_R_SUCCESS) {
                /*
                 * This is bad.  We tried to get the SOA RR at the zone top
                 * and it didn't work!
                 */
                eresult = DNS_R_SERVFAIL;
        } else {
                /*
                 * Extract the SOA MINIMUM.
                 */
                dns_rdata_soa_t soa;
                dns_rdata_t rdata = DNS_RDATA_INIT;
                result = dns_rdataset_first(rdataset);
                RUNTIME_CHECK(result == ISC_R_SUCCESS);
                dns_rdataset_current(rdataset, &rdata);
                result = dns_rdata_tostruct(&rdata, &soa, NULL);
                if (result != ISC_R_SUCCESS)
                        goto cleanup;

                if (zero_ttl) {
                        rdataset->ttl = 0;
                        if (sigrdataset != NULL)
                                sigrdataset->ttl = 0;
                }

                /*
                 * Add the SOA and its SIG to the response, with the
                 * TTLs adjusted per RFC2308 section 3.
                 */
                if (rdataset->ttl > soa.minimum)
                        rdataset->ttl = soa.minimum;
                if (sigrdataset != NULL && sigrdataset->ttl > soa.minimum)
                        sigrdataset->ttl = soa.minimum;

                if (sigrdataset != NULL)
                        sigrdatasetp = &sigrdataset;
                else
                        sigrdatasetp = NULL;
                query_addrrset(client, &name, &rdataset, sigrdatasetp, NULL,
                               DNS_SECTION_AUTHORITY);
        }

 cleanup:
        query_putrdataset(client, &rdataset);
        if (sigrdataset != NULL)
                query_putrdataset(client, &sigrdataset);
        if (name != NULL)
                query_releasename(client, &name);
        if (node != NULL)
                dns_db_detachnode(db, &node);

        return (eresult);
}

static inline isc_result_t
query_addns(ns_client_t *client, dns_db_t *db, dns_dbversion_t *version) {
        dns_name_t *name, *fname;
        dns_dbnode_t *node;
        isc_result_t result, eresult;
        dns_fixedname_t foundname;
        dns_rdataset_t *rdataset = NULL, *sigrdataset = NULL;
        dns_rdataset_t **sigrdatasetp = NULL;

        CTRACE("query_addns");
        /*
         * Initialization.
         */
        eresult = ISC_R_SUCCESS;
        name = NULL;
        rdataset = NULL;
        node = NULL;
        dns_fixedname_init(&foundname);
        fname = dns_fixedname_name(&foundname);

        /*
         * Get resources and make 'name' be the database origin.
         */
        result = dns_message_gettempname(client->message, &name);
        if (result != ISC_R_SUCCESS) {
                CTRACE("query_addns: dns_message_gettempname failed: done");
                return (result);
        }
        dns_name_init(name, NULL);
        dns_name_clone(dns_db_origin(db), name);
        rdataset = query_newrdataset(client);
        if (rdataset == NULL) {
                CTRACE("query_addns: query_newrdataset failed");
                eresult = DNS_R_SERVFAIL;
                goto cleanup;
        }
        if (WANTDNSSEC(client) && dns_db_issecure(db)) {
                sigrdataset = query_newrdataset(client);
                if (sigrdataset == NULL) {
                        CTRACE("query_addns: query_newrdataset failed");
                        eresult = DNS_R_SERVFAIL;
                        goto cleanup;
                }
        }

        /*
         * Find the NS rdataset.
         */
        result = dns_db_getoriginnode(db, &node);
        if (result == ISC_R_SUCCESS) {
                result = dns_db_findrdataset(db, node, version,
                                             dns_rdatatype_ns,
                                             0, client->now, rdataset,
                                             sigrdataset);
        } else {
                CTRACE("query_addns: calling dns_db_find");
                result = dns_db_find(db, name, NULL, dns_rdatatype_ns,
                                     client->query.dboptions, 0, &node,
                                     fname, rdataset, sigrdataset);
                CTRACE("query_addns: dns_db_find complete");
        }
        if (result != ISC_R_SUCCESS) {
                CTRACE("query_addns: "
                       "dns_db_findrdataset or dns_db_find failed");
                /*
                 * This is bad.  We tried to get the NS rdataset at the zone
                 * top and it didn't work!
                 */
                eresult = DNS_R_SERVFAIL;
        } else {
                if (sigrdataset != NULL)
                        sigrdatasetp = &sigrdataset;
                else
                        sigrdatasetp = NULL;
                query_addrrset(client, &name, &rdataset, sigrdatasetp, NULL,
                               DNS_SECTION_AUTHORITY);
        }

 cleanup:
        CTRACE("query_addns: cleanup");
        query_putrdataset(client, &rdataset);
        if (sigrdataset != NULL)
                query_putrdataset(client, &sigrdataset);
        if (name != NULL)
                query_releasename(client, &name);
        if (node != NULL)
                dns_db_detachnode(db, &node);

        CTRACE("query_addns: done");
        return (eresult);
}

static inline isc_result_t
query_addcnamelike(ns_client_t *client, dns_name_t *qname, dns_name_t *tname,
                   dns_rdataset_t *dname, dns_name_t **anamep,
                   dns_rdatatype_t type)
{
        dns_rdataset_t *rdataset;
        dns_rdatalist_t *rdatalist;
        dns_rdata_t *rdata;
        isc_result_t result;
        isc_region_t r;

        /*
         * We assume the name data referred to by tname won't go away.
         */

        REQUIRE(anamep != NULL);

        rdatalist = NULL;
        result = dns_message_gettemprdatalist(client->message, &rdatalist);
        if (result != ISC_R_SUCCESS)
                return (result);
        rdata = NULL;
        result = dns_message_gettemprdata(client->message, &rdata);
        if (result != ISC_R_SUCCESS)
                return (result);
        rdataset = NULL;
        result = dns_message_gettemprdataset(client->message, &rdataset);
        if (result != ISC_R_SUCCESS)
                return (result);
        dns_rdataset_init(rdataset);
        result = dns_name_dup(qname, client->mctx, *anamep);
        if (result != ISC_R_SUCCESS) {
                dns_message_puttemprdataset(client->message, &rdataset);
                return (result);
        }

        rdatalist->type = type;
        rdatalist->covers = 0;
        rdatalist->rdclass = client->message->rdclass;
        rdatalist->ttl = dname->ttl;

        dns_name_toregion(tname, &r);
        rdata->data = r.base;
        rdata->length = r.length;
        rdata->rdclass = client->message->rdclass;
        rdata->type = type;

        ISC_LIST_INIT(rdatalist->rdata);
        ISC_LIST_APPEND(rdatalist->rdata, rdata, link);
        RUNTIME_CHECK(dns_rdatalist_tordataset(rdatalist, rdataset)
                      == ISC_R_SUCCESS);
        rdataset->trust = dname->trust;

        query_addrrset(client, anamep, &rdataset, NULL, NULL,
                       DNS_SECTION_ANSWER);

        if (rdataset != NULL) {
                if (dns_rdataset_isassociated(rdataset))
                        dns_rdataset_disassociate(rdataset);
                dns_message_puttemprdataset(client->message, &rdataset);
        }

        return (ISC_R_SUCCESS);
}

/*
 * Mark the RRsets as secure.  Update the cache (db) to reflect the
 * change in trust level.
 */
static void
mark_secure(ns_client_t *client, dns_db_t *db, dns_name_t *name,
            isc_uint32_t ttl, dns_rdataset_t *rdataset,
            dns_rdataset_t *sigrdataset)
{
        isc_result_t result;
        dns_dbnode_t *node = NULL;

        rdataset->trust = dns_trust_secure;
        sigrdataset->trust = dns_trust_secure;

        /*
         * Save the updated secure state.  Ignore failures.
         */
        result = dns_db_findnode(db, name, ISC_TRUE, &node);
        if (result != ISC_R_SUCCESS)
                return;
        /*
         * Bound the validated ttls then minimise.
         */
        if (sigrdataset->ttl > ttl)
                sigrdataset->ttl = ttl;
        if (rdataset->ttl > ttl)
                rdataset->ttl = ttl;
        if (rdataset->ttl > sigrdataset->ttl)
                rdataset->ttl = sigrdataset->ttl;
        else
                sigrdataset->ttl = rdataset->ttl;

        (void)dns_db_addrdataset(db, node, NULL, client->now, rdataset,
                                 0, NULL);
        (void)dns_db_addrdataset(db, node, NULL, client->now, sigrdataset,
                                 0, NULL);
        dns_db_detachnode(db, &node);
}

/*
 * Find the secure key that corresponds to rrsig.
 * Note: 'keyrdataset' maintains state between successive calls,
 * there may be multiple keys with the same keyid.
 * Return ISC_FALSE if we have exhausted all the possible keys.
 */
static isc_boolean_t
get_key(ns_client_t *client, dns_db_t *db, dns_rdata_rrsig_t *rrsig,
        dns_rdataset_t *keyrdataset, dst_key_t **keyp)
{
        isc_result_t result;
        dns_dbnode_t *node = NULL;
        isc_boolean_t secure = ISC_FALSE;

        if (!dns_rdataset_isassociated(keyrdataset)) {
                result = dns_db_findnode(db, &rrsig->signer, ISC_FALSE, &node);
                if (result != ISC_R_SUCCESS)
                        return (ISC_FALSE);

                result = dns_db_findrdataset(db, node, NULL,
                                             dns_rdatatype_dnskey, 0,
                                             client->now, keyrdataset, NULL);
                dns_db_detachnode(db, &node);
                if (result != ISC_R_SUCCESS)
                        return (ISC_FALSE);

                if (keyrdataset->trust != dns_trust_secure)
                        return (ISC_FALSE);

                result = dns_rdataset_first(keyrdataset);
        } else
                result = dns_rdataset_next(keyrdataset);

        for ( ; result == ISC_R_SUCCESS;
             result = dns_rdataset_next(keyrdataset)) {
                dns_rdata_t rdata = DNS_RDATA_INIT;
                isc_buffer_t b;

                dns_rdataset_current(keyrdataset, &rdata);
                isc_buffer_init(&b, rdata.data, rdata.length);
                isc_buffer_add(&b, rdata.length);
                result = dst_key_fromdns(&rrsig->signer, rdata.rdclass, &b,
                                         client->mctx, keyp);
                if (result != ISC_R_SUCCESS)
                        continue;
                if (rrsig->algorithm == (dns_secalg_t)dst_key_alg(*keyp) &&
                    rrsig->keyid == (dns_keytag_t)dst_key_id(*keyp) &&
                    dst_key_iszonekey(*keyp)) {
                        secure = ISC_TRUE;
                        break;
                }
                dst_key_free(keyp);
        }
        return (secure);
}

static isc_boolean_t
verify(dst_key_t *key, dns_name_t *name, dns_rdataset_t *rdataset,
       dns_rdata_t *rdata, isc_mem_t *mctx, isc_boolean_t acceptexpired)
{
        isc_result_t result;
        dns_fixedname_t fixed;
        isc_boolean_t ignore = ISC_FALSE;

        dns_fixedname_init(&fixed);

again:
        result = dns_dnssec_verify2(name, rdataset, key, ignore, mctx,
                                    rdata, NULL);
        if (result == DNS_R_SIGEXPIRED && acceptexpired) {
                ignore = ISC_TRUE;
                goto again;
        }
        if (result == ISC_R_SUCCESS || result == DNS_R_FROMWILDCARD)
                return (ISC_TRUE);
        return (ISC_FALSE);
}

/*
 * Validate the rdataset if possible with available records.
 */
static isc_boolean_t
validate(ns_client_t *client, dns_db_t *db, dns_name_t *name,
         dns_rdataset_t *rdataset, dns_rdataset_t *sigrdataset)
{
        isc_result_t result;
        dns_rdata_t rdata = DNS_RDATA_INIT;
        dns_rdata_rrsig_t rrsig;
        dst_key_t *key = NULL;
        dns_rdataset_t keyrdataset;

        if (sigrdataset == NULL || !dns_rdataset_isassociated(sigrdataset))
                return (ISC_FALSE);

        for (result = dns_rdataset_first(sigrdataset);
             result == ISC_R_SUCCESS;
             result = dns_rdataset_next(sigrdataset)) {

                dns_rdata_reset(&rdata);
                dns_rdataset_current(sigrdataset, &rdata);
                result = dns_rdata_tostruct(&rdata, &rrsig, NULL);
                if (result != ISC_R_SUCCESS)
                        return (ISC_FALSE);
                if (!dns_resolver_algorithm_supported(client->view->resolver,
                                                      name, rrsig.algorithm))
                        continue;
                if (!dns_name_issubdomain(name, &rrsig.signer))
                        continue;
                dns_rdataset_init(&keyrdataset);
                do {
                        if (!get_key(client, db, &rrsig, &keyrdataset, &key))
                                break;
                        if (verify(key, name, rdataset, &rdata, client->mctx,
                                   client->view->acceptexpired)) {
                                dst_key_free(&key);
                                dns_rdataset_disassociate(&keyrdataset);
                                mark_secure(client, db, name,
                                            rrsig.originalttl,
                                            rdataset, sigrdataset);
                                return (ISC_TRUE);
                        }
                        dst_key_free(&key);
                } while (1);
                if (dns_rdataset_isassociated(&keyrdataset))
                        dns_rdataset_disassociate(&keyrdataset);
        }
        return (ISC_FALSE);
}

static void
query_addbestns(ns_client_t *client) {
        dns_db_t *db, *zdb;
        dns_dbnode_t *node;
        dns_name_t *fname, *zfname;
        dns_rdataset_t *rdataset, *sigrdataset, *zrdataset, *zsigrdataset;
        isc_boolean_t is_zone, use_zone;
        isc_buffer_t *dbuf;
        isc_result_t result;
        dns_dbversion_t *version;
        dns_zone_t *zone;
        isc_buffer_t b;

        CTRACE("query_addbestns");
        fname = NULL;
        zfname = NULL;
        rdataset = NULL;
        zrdataset = NULL;
        sigrdataset = NULL;
        zsigrdataset = NULL;
        node = NULL;
        db = NULL;
        zdb = NULL;
        version = NULL;
        zone = NULL;
        is_zone = ISC_FALSE;
        use_zone = ISC_FALSE;

        /*
         * Find the right database.
         */
        result = query_getdb(client, client->query.qname, dns_rdatatype_ns, 0,
                             &zone, &db, &version, &is_zone);
        if (result != ISC_R_SUCCESS)
                goto cleanup;

 db_find:
        /*
         * We'll need some resources...
         */
        dbuf = query_getnamebuf(client);
        if (dbuf == NULL)
                goto cleanup;
        fname = query_newname(client, dbuf, &b);
        rdataset = query_newrdataset(client);
        if (fname == NULL || rdataset == NULL)
                goto cleanup;
        /*
         * Get the RRSIGs if the client requested them or if we may
         * need to validate answers from the cache.
         */
        if (WANTDNSSEC(client) || !is_zone) {
                sigrdataset = query_newrdataset(client);
                if (sigrdataset == NULL)
                        goto cleanup;
        }

        /*
         * Now look for the zonecut.
         */
        if (is_zone) {
                result = dns_db_find(db, client->query.qname, version,
                                     dns_rdatatype_ns, client->query.dboptions,
                                     client->now, &node, fname,
                                     rdataset, sigrdataset);
                if (result != DNS_R_DELEGATION)
                        goto cleanup;
                if (USECACHE(client)) {
                        query_keepname(client, fname, dbuf);
                        zdb = db;
                        zfname = fname;
                        fname = NULL;
                        zrdataset = rdataset;
                        rdataset = NULL;
                        zsigrdataset = sigrdataset;
                        sigrdataset = NULL;
                        dns_db_detachnode(db, &node);
                        version = NULL;
                        db = NULL;
                        dns_db_attach(client->view->cachedb, &db);
                        is_zone = ISC_FALSE;
                        goto db_find;
                }
        } else {
                result = dns_db_findzonecut(db, client->query.qname,
                                            client->query.dboptions,
                                            client->now, &node, fname,
                                            rdataset, sigrdataset);
                if (result == ISC_R_SUCCESS) {
                        if (zfname != NULL &&
                            !dns_name_issubdomain(fname, zfname)) {
                                /*
                                 * We found a zonecut in the cache, but our
                                 * zone delegation is better.
                                 */
                                use_zone = ISC_TRUE;
                        }
                } else if (result == ISC_R_NOTFOUND && zfname != NULL) {
                        /*
                         * We didn't find anything in the cache, but we
                         * have a zone delegation, so use it.
                         */
                        use_zone = ISC_TRUE;
                } else
                        goto cleanup;
        }

        if (use_zone) {
                query_releasename(client, &fname);
                fname = zfname;
                zfname = NULL;
                /*
                 * We've already done query_keepname() on
                 * zfname, so we must set dbuf to NULL to
                 * prevent query_addrrset() from trying to
                 * call query_keepname() again.
                 */
                dbuf = NULL;
                query_putrdataset(client, &rdataset);
                if (sigrdataset != NULL)
                        query_putrdataset(client, &sigrdataset);
                rdataset = zrdataset;
                zrdataset = NULL;
                sigrdataset = zsigrdataset;
                zsigrdataset = NULL;
        }

        /*
         * Attempt to validate RRsets that are pending or that are glue.
         */
        if ((DNS_TRUST_PENDING(rdataset->trust) ||
             (sigrdataset != NULL && DNS_TRUST_PENDING(sigrdataset->trust)))
            && !validate(client, db, fname, rdataset, sigrdataset) &&
            !PENDINGOK(client->query.dboptions))
                goto cleanup;

        if ((DNS_TRUST_GLUE(rdataset->trust) ||
             (sigrdataset != NULL && DNS_TRUST_GLUE(sigrdataset->trust))) &&
            !validate(client, db, fname, rdataset, sigrdataset) &&
            SECURE(client) && WANTDNSSEC(client))
                goto cleanup;

        /*
         * If the client doesn't want DNSSEC we can discard the sigrdataset
         * now.
         */
        if (!WANTDNSSEC(client))
                query_putrdataset(client, &sigrdataset);
        query_addrrset(client, &fname, &rdataset, &sigrdataset, dbuf,
                       DNS_SECTION_AUTHORITY);

 cleanup:
        if (rdataset != NULL)
                query_putrdataset(client, &rdataset);
        if (sigrdataset != NULL)
                query_putrdataset(client, &sigrdataset);
        if (fname != NULL)
                query_releasename(client, &fname);
        if (node != NULL)
                dns_db_detachnode(db, &node);
        if (db != NULL)
                dns_db_detach(&db);
        if (zone != NULL)
                dns_zone_detach(&zone);
        if (zdb != NULL) {
                query_putrdataset(client, &zrdataset);
                if (zsigrdataset != NULL)
                        query_putrdataset(client, &zsigrdataset);
                if (zfname != NULL)
                        query_releasename(client, &zfname);
                dns_db_detach(&zdb);
        }
}

static void
fixrdataset(ns_client_t *client, dns_rdataset_t **rdataset) {
        if (*rdataset == NULL)
                *rdataset = query_newrdataset(client);
        else  if (dns_rdataset_isassociated(*rdataset))
                dns_rdataset_disassociate(*rdataset);
}

static void
fixfname(ns_client_t *client, dns_name_t **fname, isc_buffer_t **dbuf,
         isc_buffer_t *nbuf)
{
        if (*fname == NULL) {
                *dbuf = query_getnamebuf(client);
                if (*dbuf == NULL)
                        return;
                *fname = query_newname(client, *dbuf, nbuf);
        }
}

static void
query_addds(ns_client_t *client, dns_db_t *db, dns_dbnode_t *node,
            dns_dbversion_t *version, dns_name_t *name)
{
        dns_fixedname_t fixed;
        dns_name_t *fname = NULL;
        dns_name_t *rname;
        dns_rdataset_t *rdataset, *sigrdataset;
        isc_buffer_t *dbuf, b;
        isc_result_t result;
        unsigned int count;

        CTRACE("query_addds");
        rname = NULL;
        rdataset = NULL;
        sigrdataset = NULL;

        /*
         * We'll need some resources...
         */
        rdataset = query_newrdataset(client);
        sigrdataset = query_newrdataset(client);
        if (rdataset == NULL || sigrdataset == NULL)
                goto cleanup;

        /*
         * Look for the DS record, which may or may not be present.
         */
        result = dns_db_findrdataset(db, node, version, dns_rdatatype_ds, 0,
                                     client->now, rdataset, sigrdataset);
        /*
         * If we didn't find it, look for an NSEC.
         */
        if (result == ISC_R_NOTFOUND)
                result = dns_db_findrdataset(db, node, version,
                                             dns_rdatatype_nsec, 0, client->now,
                                             rdataset, sigrdataset);
        if (result != ISC_R_SUCCESS && result != ISC_R_NOTFOUND)
                goto addnsec3;
        if (!dns_rdataset_isassociated(rdataset) ||
            !dns_rdataset_isassociated(sigrdataset))
                goto addnsec3;

        /*
         * We've already added the NS record, so if the name's not there,
         * we have other problems.  Use this name rather than calling
         * query_addrrset().
         */
        result = dns_message_firstname(client->message, DNS_SECTION_AUTHORITY);
        if (result != ISC_R_SUCCESS)
                goto cleanup;

        rname = NULL;
        dns_message_currentname(client->message, DNS_SECTION_AUTHORITY,
                                &rname);
        result = dns_message_findtype(rname, dns_rdatatype_ns, 0, NULL);
        if (result != ISC_R_SUCCESS)
                goto cleanup;

        ISC_LIST_APPEND(rname->list, rdataset, link);
        ISC_LIST_APPEND(rname->list, sigrdataset, link);
        rdataset = NULL;
        sigrdataset = NULL;
        return;

   addnsec3:
        if (!dns_db_iszone(db))
                goto cleanup;
        /*
         * Add the NSEC3 which proves the DS does not exist.
         */
        dbuf = query_getnamebuf(client);
        if (dbuf == NULL)
                goto cleanup;
        fname = query_newname(client, dbuf, &b);
        dns_fixedname_init(&fixed);
        if (dns_rdataset_isassociated(rdataset))
                dns_rdataset_disassociate(rdataset);
        if (dns_rdataset_isassociated(sigrdataset))
                dns_rdataset_disassociate(sigrdataset);
        query_findclosestnsec3(name, db, version, client, rdataset,
                               sigrdataset, fname, ISC_TRUE,
                               dns_fixedname_name(&fixed));
        if (!dns_rdataset_isassociated(rdataset))
                goto cleanup;
        query_addrrset(client, &fname, &rdataset, &sigrdataset, dbuf,
                       DNS_SECTION_AUTHORITY);
        /*
         * Did we find the closest provable encloser instead?
         * If so add the nearest to the closest provable encloser.
         */
        if (!dns_name_equal(name, dns_fixedname_name(&fixed))) {
                count = dns_name_countlabels(dns_fixedname_name(&fixed)) + 1;
                dns_name_getlabelsequence(name,
                                          dns_name_countlabels(name) - count,
                                          count, dns_fixedname_name(&fixed));
                fixfname(client, &fname, &dbuf, &b);
                fixrdataset(client, &rdataset);
                fixrdataset(client, &sigrdataset);
                if (fname == NULL || rdataset == NULL || sigrdataset == NULL)
                                goto cleanup;
                query_findclosestnsec3(dns_fixedname_name(&fixed), db, version,
                                       client, rdataset, sigrdataset, fname,
                                       ISC_FALSE, NULL);
                if (!dns_rdataset_isassociated(rdataset))
                        goto cleanup;
                query_addrrset(client, &fname, &rdataset, &sigrdataset, dbuf,
                               DNS_SECTION_AUTHORITY);
        }

 cleanup:
        if (rdataset != NULL)
                query_putrdataset(client, &rdataset);
        if (sigrdataset != NULL)
                query_putrdataset(client, &sigrdataset);
        if (fname != NULL)
                query_releasename(client, &fname);
}

static void
query_addwildcardproof(ns_client_t *client, dns_db_t *db,
                       dns_dbversion_t *version, dns_name_t *name,
                       isc_boolean_t ispositive)
{
        isc_buffer_t *dbuf, b;
        dns_name_t *fname;
        dns_rdataset_t *rdataset, *sigrdataset;
        dns_fixedname_t wfixed;
        dns_name_t *wname;
        dns_dbnode_t *node;
        unsigned int options;
        unsigned int olabels, nlabels, labels;
        isc_result_t result;
        dns_rdata_t rdata = DNS_RDATA_INIT;
        dns_rdata_nsec_t nsec;
        isc_boolean_t have_wname;
        int order;
        dns_fixedname_t cfixed;
        dns_name_t *cname;

        CTRACE("query_addwildcardproof");
        fname = NULL;
        rdataset = NULL;
        sigrdataset = NULL;
        node = NULL;

        /*
         * Get the NOQNAME proof then if !ispositive
         * get the NOWILDCARD proof.
         *
         * DNS_DBFIND_NOWILD finds the NSEC records that covers the
         * name ignoring any wildcard.  From the owner and next names
         * of this record you can compute which wildcard (if it exists)
         * will match by finding the longest common suffix of the
         * owner name and next names with the qname and prefixing that
         * with the wildcard label.
         *
         * e.g.
         *   Given:
         *      example SOA
         *      example NSEC b.example
         *      b.example A
         *      b.example NSEC a.d.example
         *      a.d.example A
         *      a.d.example NSEC g.f.example
         *      g.f.example A
         *      g.f.example NSEC z.i.example
         *      z.i.example A
         *      z.i.example NSEC example
         *
         *   QNAME:
         *   a.example -> example NSEC b.example
         *      owner common example
         *      next common example
         *      wild *.example
         *   d.b.example -> b.example NSEC a.d.example
         *      owner common b.example
         *      next common example
         *      wild *.b.example
         *   a.f.example -> a.d.example NSEC g.f.example
         *      owner common example
         *      next common f.example
         *      wild *.f.example
         *  j.example -> z.i.example NSEC example
         *      owner common example
         *      next common example
         *      wild *.example
         */
        options = client->query.dboptions | DNS_DBFIND_NOWILD;
        dns_fixedname_init(&wfixed);
        wname = dns_fixedname_name(&wfixed);
 again:
        have_wname = ISC_FALSE;
        /*
         * We'll need some resources...
         */
        dbuf = query_getnamebuf(client);
        if (dbuf == NULL)
                goto cleanup;
        fname = query_newname(client, dbuf, &b);
        rdataset = query_newrdataset(client);
        sigrdataset = query_newrdataset(client);
        if (fname == NULL || rdataset == NULL || sigrdataset == NULL)
                goto cleanup;

        result = dns_db_find(db, name, version, dns_rdatatype_nsec, options,
                             0, &node, fname, rdataset, sigrdataset);
        if (node != NULL)
                dns_db_detachnode(db, &node);

        if (!dns_rdataset_isassociated(rdataset)) {
                /*
                 * No NSEC proof available, return NSEC3 proofs instead.
                 */
                dns_fixedname_init(&cfixed);
                cname = dns_fixedname_name(&cfixed);
                /*
                 * Find the closest encloser.
                 */
                dns_name_copy(name, cname, NULL);
                while (result == DNS_R_NXDOMAIN) {
                        labels = dns_name_countlabels(cname) - 1;
                        dns_name_split(cname, labels, NULL, cname);
                        result = dns_db_find(db, cname, version,
                                             dns_rdatatype_nsec,
                                             options, 0, NULL, fname,
                                             NULL, NULL);
                }
                /*
                 * Add closest (provable) encloser NSEC3.
                 */
                query_findclosestnsec3(cname, db, NULL, client, rdataset,
                                       sigrdataset, fname, ISC_TRUE, cname);
                if (!dns_rdataset_isassociated(rdataset))
                        goto cleanup;
                query_addrrset(client, &fname, &rdataset, &sigrdataset,
                               dbuf, DNS_SECTION_AUTHORITY);

                /*
                 * Replace resources which were consumed by query_addrrset.
                 */
                if (fname == NULL) {
                        dbuf = query_getnamebuf(client);
                        if (dbuf == NULL)
                                goto cleanup;
                        fname = query_newname(client, dbuf, &b);
                }

                if (rdataset == NULL)
                        rdataset = query_newrdataset(client);
                else if (dns_rdataset_isassociated(rdataset))
                        dns_rdataset_disassociate(rdataset);

                if (sigrdataset == NULL)
                        sigrdataset = query_newrdataset(client);
                else if (dns_rdataset_isassociated(sigrdataset))
                        dns_rdataset_disassociate(sigrdataset);

                if (fname == NULL || rdataset == NULL || sigrdataset == NULL)
                        goto cleanup;
                /*
                 * Add no qname proof.
                 */
                labels = dns_name_countlabels(cname) + 1;
                if (dns_name_countlabels(name) == labels)
                        dns_name_copy(name, wname, NULL);
                else
                        dns_name_split(name, labels, NULL, wname);

                query_findclosestnsec3(wname, db, NULL, client, rdataset,
                                       sigrdataset, fname, ISC_FALSE, NULL);
                if (!dns_rdataset_isassociated(rdataset))
                        goto cleanup;
                query_addrrset(client, &fname, &rdataset, &sigrdataset,
                               dbuf, DNS_SECTION_AUTHORITY);

                if (ispositive)
                        goto cleanup;

                /*
                 * Replace resources which were consumed by query_addrrset.
                 */
                if (fname == NULL) {
                        dbuf = query_getnamebuf(client);
                        if (dbuf == NULL)
                                goto cleanup;
                        fname = query_newname(client, dbuf, &b);
                }

                if (rdataset == NULL)
                        rdataset = query_newrdataset(client);
                else if (dns_rdataset_isassociated(rdataset))
                        dns_rdataset_disassociate(rdataset);

                if (sigrdataset == NULL)
                        sigrdataset = query_newrdataset(client);
                else if (dns_rdataset_isassociated(sigrdataset))
                        dns_rdataset_disassociate(sigrdataset);

                if (fname == NULL || rdataset == NULL || sigrdataset == NULL)
                        goto cleanup;
                /*
                 * Add the no wildcard proof.
                 */
                result = dns_name_concatenate(dns_wildcardname,
                                              cname, wname, NULL);
                if (result != ISC_R_SUCCESS)
                        goto cleanup;

                query_findclosestnsec3(wname, db, NULL, client, rdataset,
                                       sigrdataset, fname, ISC_FALSE, NULL);
                if (!dns_rdataset_isassociated(rdataset))
                        goto cleanup;
                query_addrrset(client, &fname, &rdataset, &sigrdataset,
                               dbuf, DNS_SECTION_AUTHORITY);

                goto cleanup;
        } else if (result == DNS_R_NXDOMAIN) {
                if (!ispositive)
                        result = dns_rdataset_first(rdataset);
                if (result == ISC_R_SUCCESS) {
                        dns_rdataset_current(rdataset, &rdata);
                        result = dns_rdata_tostruct(&rdata, &nsec, NULL);
                }
                if (result == ISC_R_SUCCESS) {
                        (void)dns_name_fullcompare(name, fname, &order,
                                                   &olabels);
                        (void)dns_name_fullcompare(name, &nsec.next, &order,
                                                   &nlabels);
                        /*
                         * Check for a pathological condition created when
                         * serving some malformed signed zones and bail out.
                         */
                        if (dns_name_countlabels(name) == nlabels)
                                goto cleanup;

                        if (olabels > nlabels)
                                dns_name_split(name, olabels, NULL, wname);
                        else
                                dns_name_split(name, nlabels, NULL, wname);
                        result = dns_name_concatenate(dns_wildcardname,
                                                      wname, wname, NULL);
                        if (result == ISC_R_SUCCESS)
                                have_wname = ISC_TRUE;
                        dns_rdata_freestruct(&nsec);
                }
                query_addrrset(client, &fname, &rdataset, &sigrdataset,
                               dbuf, DNS_SECTION_AUTHORITY);
        }
        if (rdataset != NULL)
                query_putrdataset(client, &rdataset);
        if (sigrdataset != NULL)
                query_putrdataset(client, &sigrdataset);
        if (fname != NULL)
                query_releasename(client, &fname);
        if (have_wname) {
                ispositive = ISC_TRUE;  /* prevent loop */
                if (!dns_name_equal(name, wname)) {
                        name = wname;
                        goto again;
                }
        }
 cleanup:
        if (rdataset != NULL)
                query_putrdataset(client, &rdataset);
        if (sigrdataset != NULL)
                query_putrdataset(client, &sigrdataset);
        if (fname != NULL)
                query_releasename(client, &fname);
}

static void
query_addnxrrsetnsec(ns_client_t *client, dns_db_t *db,
                     dns_dbversion_t *version, dns_name_t **namep,
                     dns_rdataset_t **rdatasetp, dns_rdataset_t **sigrdatasetp)
{
        dns_name_t *name;
        dns_rdataset_t *sigrdataset;
        dns_rdata_t sigrdata;
        dns_rdata_rrsig_t sig;
        unsigned int labels;
        isc_buffer_t *dbuf, b;
        dns_name_t *fname;
        isc_result_t result;

        name = *namep;
        if ((name->attributes & DNS_NAMEATTR_WILDCARD) == 0) {
                query_addrrset(client, namep, rdatasetp, sigrdatasetp,
                               NULL, DNS_SECTION_AUTHORITY);
                return;
        }

        if (sigrdatasetp == NULL)
                return;

        sigrdataset = *sigrdatasetp;
        if (sigrdataset == NULL || !dns_rdataset_isassociated(sigrdataset))
                return;
        result = dns_rdataset_first(sigrdataset);
        if (result != ISC_R_SUCCESS)
                return;
        dns_rdata_init(&sigrdata);
        dns_rdataset_current(sigrdataset, &sigrdata);
        result = dns_rdata_tostruct(&sigrdata, &sig, NULL);
        if (result != ISC_R_SUCCESS)
                return;

        labels = dns_name_countlabels(name);
        if ((unsigned int)sig.labels + 1 >= labels)
                return;

        /* XXX */
        query_addwildcardproof(client, db, version, client->query.qname,
                               ISC_TRUE);

        /*
         * We'll need some resources...
         */
        dbuf = query_getnamebuf(client);
        if (dbuf == NULL)
                return;
        fname = query_newname(client, dbuf, &b);
        if (fname == NULL)
                return;
        dns_name_split(name, sig.labels + 1, NULL, fname);
        /* This will succeed, since we've stripped labels. */
        RUNTIME_CHECK(dns_name_concatenate(dns_wildcardname, fname, fname,
                                           NULL) == ISC_R_SUCCESS);
        query_addrrset(client, &fname, rdatasetp, sigrdatasetp,
                       dbuf, DNS_SECTION_AUTHORITY);
}

static void
query_resume(isc_task_t *task, isc_event_t *event) {
        dns_fetchevent_t *devent = (dns_fetchevent_t *)event;
        dns_fetch_t *fetch;
        ns_client_t *client;
        isc_boolean_t fetch_canceled, client_shuttingdown;
        isc_result_t result;
        isc_logcategory_t *logcategory = NS_LOGCATEGORY_QUERY_EERRORS;
        int errorloglevel;

        /*
         * Resume a query after recursion.
         */

        UNUSED(task);

        REQUIRE(event->ev_type == DNS_EVENT_FETCHDONE);
        client = devent->ev_arg;
        REQUIRE(NS_CLIENT_VALID(client));
        REQUIRE(task == client->task);
        REQUIRE(RECURSING(client));

        LOCK(&client->query.fetchlock);
        if (client->query.fetch != NULL) {
                /*
                 * This is the fetch we've been waiting for.
                 */
                INSIST(devent->fetch == client->query.fetch);
                client->query.fetch = NULL;
                fetch_canceled = ISC_FALSE;
                /*
                 * Update client->now.
                 */
                isc_stdtime_get(&client->now);
        } else {
                /*
                 * This is a fetch completion event for a canceled fetch.
                 * Clean up and don't resume the find.
                 */
                fetch_canceled = ISC_TRUE;
        }
        UNLOCK(&client->query.fetchlock);
        INSIST(client->query.fetch == NULL);

        client->query.attributes &= ~NS_QUERYATTR_RECURSING;
        fetch = devent->fetch;
        devent->fetch = NULL;

        /*
         * If this client is shutting down, or this transaction
         * has timed out, do not resume the find.
         */
        client_shuttingdown = ns_client_shuttingdown(client);
        if (fetch_canceled || client_shuttingdown) {
                if (devent->node != NULL)
                        dns_db_detachnode(devent->db, &devent->node);
                if (devent->db != NULL)
                        dns_db_detach(&devent->db);
                query_putrdataset(client, &devent->rdataset);
                if (devent->sigrdataset != NULL)
                        query_putrdataset(client, &devent->sigrdataset);
                isc_event_free(&event);
                if (fetch_canceled)
                        query_error(client, DNS_R_SERVFAIL, __LINE__);
                else
                        query_next(client, ISC_R_CANCELED);
                /*
                 * This may destroy the client.
                 */
                ns_client_detach(&client);
        } else {
                result = query_find(client, devent, 0);
                if (result != ISC_R_SUCCESS) {
                        if (result == DNS_R_SERVFAIL)
                                errorloglevel = ISC_LOG_DEBUG(2);
                        else
                                errorloglevel = ISC_LOG_DEBUG(4);
                        if (isc_log_wouldlog(ns_g_lctx, errorloglevel)) {
                                dns_resolver_logfetch(fetch, ns_g_lctx,
                                                      logcategory,
                                                      NS_LOGMODULE_QUERY,
                                                      errorloglevel, ISC_FALSE);
                        }
                }
        }

        dns_resolver_destroyfetch(&fetch);
}

static isc_result_t
query_recurse(ns_client_t *client, dns_rdatatype_t qtype, dns_name_t *qdomain,
              dns_rdataset_t *nameservers, isc_boolean_t resuming)
{
        isc_result_t result;
        dns_rdataset_t *rdataset, *sigrdataset;
        isc_sockaddr_t *peeraddr;

        if (!resuming)
                inc_stats(client, dns_nsstatscounter_recursion);

        /*
         * We are about to recurse, which means that this client will
         * be unavailable for serving new requests for an indeterminate
         * amount of time.  If this client is currently responsible
         * for handling incoming queries, set up a new client
         * object to handle them while we are waiting for a
         * response.  There is no need to replace TCP clients
         * because those have already been replaced when the
         * connection was accepted (if allowed by the TCP quota).
         */
        if (client->recursionquota == NULL) {
                result = isc_quota_attach(&ns_g_server->recursionquota,
                                          &client->recursionquota);
                if  (result == ISC_R_SOFTQUOTA) {
                        static isc_stdtime_t last = 0;
                        isc_stdtime_t now;
                        isc_stdtime_get(&now);
                        if (now != last) {
                                last = now;
                                ns_client_log(client, NS_LOGCATEGORY_CLIENT,
                                              NS_LOGMODULE_QUERY,
                                              ISC_LOG_WARNING,
                                              "recursive-clients soft limit "
                                              "exceeded (%d/%d/%d), "
                                              "aborting oldest query",
                                              client->recursionquota->used,
                                              client->recursionquota->soft,
                                              client->recursionquota->max);
                        }
                        ns_client_killoldestquery(client);
                        result = ISC_R_SUCCESS;
                } else if (result == ISC_R_QUOTA) {
                        static isc_stdtime_t last = 0;
                        isc_stdtime_t now;
                        isc_stdtime_get(&now);
                        if (now != last) {
                                last = now;
                                ns_client_log(client, NS_LOGCATEGORY_CLIENT,
                                              NS_LOGMODULE_QUERY,
                                              ISC_LOG_WARNING,
                                              "no more recursive clients "
                                              "(%d/%d/%d): %s",
                                              ns_g_server->recursionquota.used,
                                              ns_g_server->recursionquota.soft,
                                              ns_g_server->recursionquota.max,
                                              isc_result_totext(result));
                        }
                        ns_client_killoldestquery(client);
                }
                if (result == ISC_R_SUCCESS && !client->mortal &&
                    (client->attributes & NS_CLIENTATTR_TCP) == 0) {
                        result = ns_client_replace(client);
                        if (result != ISC_R_SUCCESS) {
                                ns_client_log(client, NS_LOGCATEGORY_CLIENT,
                                              NS_LOGMODULE_QUERY,
                                              ISC_LOG_WARNING,
                                              "ns_client_replace() failed: %s",
                                              isc_result_totext(result));
                                isc_quota_detach(&client->recursionquota);
                        }
                }
                if (result != ISC_R_SUCCESS)
                        return (result);
                ns_client_recursing(client);
        }

        /*
         * Invoke the resolver.
         */
        REQUIRE(nameservers == NULL || nameservers->type == dns_rdatatype_ns);
        REQUIRE(client->query.fetch == NULL);

        rdataset = query_newrdataset(client);
        if (rdataset == NULL)
                return (ISC_R_NOMEMORY);
        if (WANTDNSSEC(client)) {
                sigrdataset = query_newrdataset(client);
                if (sigrdataset == NULL) {
                        query_putrdataset(client, &rdataset);
                        return (ISC_R_NOMEMORY);
                }
        } else
                sigrdataset = NULL;

        if (client->query.timerset == ISC_FALSE)
                ns_client_settimeout(client, 60);
        if ((client->attributes & NS_CLIENTATTR_TCP) == 0)
                peeraddr = &client->peeraddr;
        else
                peeraddr = NULL;
        result = dns_resolver_createfetch2(client->view->resolver,
                                           client->query.qname,
                                           qtype, qdomain, nameservers,
                                           NULL, peeraddr, client->message->id,
                                           client->query.fetchoptions,
                                           client->task,
                                           query_resume, client,
                                           rdataset, sigrdataset,
                                           &client->query.fetch);

        if (result == ISC_R_SUCCESS) {
                /*
                 * Record that we're waiting for an event.  A client which
                 * is shutting down will not be destroyed until all the
                 * events have been received.
                 */
        } else {
                query_putrdataset(client, &rdataset);
                if (sigrdataset != NULL)
                        query_putrdataset(client, &sigrdataset);
        }

        return (result);
}

#define MAX_RESTARTS 16

#define QUERY_ERROR(r) \
do { \
        eresult = r; \
        want_restart = ISC_FALSE; \
        line = __LINE__; \
} while (0)

#define RECURSE_ERROR(r) \
do { \
        if ((r) == DNS_R_DUPLICATE || (r) == DNS_R_DROP) \
                QUERY_ERROR(r); \
        else \
                QUERY_ERROR(DNS_R_SERVFAIL); \
} while (0)

/*
 * Extract a network address from the RDATA of an A or AAAA
 * record.
 *
 * Returns:
 *      ISC_R_SUCCESS
 *      ISC_R_NOTIMPLEMENTED    The rdata is not a known address type.
 */
static isc_result_t
rdata_tonetaddr(const dns_rdata_t *rdata, isc_netaddr_t *netaddr) {
        struct in_addr ina;
        struct in6_addr in6a;

        switch (rdata->type) {
        case dns_rdatatype_a:
                INSIST(rdata->length == 4);
                memcpy(&ina.s_addr, rdata->data, 4);
                isc_netaddr_fromin(netaddr, &ina);
                return (ISC_R_SUCCESS);
        case dns_rdatatype_aaaa:
                INSIST(rdata->length == 16);
                memcpy(in6a.s6_addr, rdata->data, 16);
                isc_netaddr_fromin6(netaddr, &in6a);
                return (ISC_R_SUCCESS);
        default:
                return (ISC_R_NOTIMPLEMENTED);
        }
}

/*
 * Find the sort order of 'rdata' in the topology-like
 * ACL forming the second element in a 2-element top-level
 * sortlist statement.
 */
static int
query_sortlist_order_2element(const dns_rdata_t *rdata, const void *arg) {
        isc_netaddr_t netaddr;

        if (rdata_tonetaddr(rdata, &netaddr) != ISC_R_SUCCESS)
                return (INT_MAX);
        return (ns_sortlist_addrorder2(&netaddr, arg));
}

/*
 * Find the sort order of 'rdata' in the matching element
 * of a 1-element top-level sortlist statement.
 */
static int
query_sortlist_order_1element(const dns_rdata_t *rdata, const void *arg) {
        isc_netaddr_t netaddr;

        if (rdata_tonetaddr(rdata, &netaddr) != ISC_R_SUCCESS)
                return (INT_MAX);
        return (ns_sortlist_addrorder1(&netaddr, arg));
}

/*
 * Find the sortlist statement that applies to 'client' and set up
 * the sortlist info in in client->message appropriately.
 */
static void
setup_query_sortlist(ns_client_t *client) {
        isc_netaddr_t netaddr;
        dns_rdatasetorderfunc_t order = NULL;
        const void *order_arg = NULL;

        isc_netaddr_fromsockaddr(&netaddr, &client->peeraddr);
        switch (ns_sortlist_setup(client->view->sortlist,
                               &netaddr, &order_arg)) {
        case NS_SORTLISTTYPE_1ELEMENT:
                order = query_sortlist_order_1element;
                break;
        case NS_SORTLISTTYPE_2ELEMENT:
                order = query_sortlist_order_2element;
                break;
        case NS_SORTLISTTYPE_NONE:
                order = NULL;
                break;
        default:
                INSIST(0);
                break;
        }
        dns_message_setsortorder(client->message, order, order_arg);
}

static void
query_addnoqnameproof(ns_client_t *client, dns_rdataset_t *rdataset) {
        isc_buffer_t *dbuf, b;
        dns_name_t *fname;
        dns_rdataset_t *neg, *negsig;
        isc_result_t result = ISC_R_NOMEMORY;

        CTRACE("query_addnoqnameproof");

        fname = NULL;
        neg = NULL;
        negsig = NULL;

        dbuf = query_getnamebuf(client);
        if (dbuf == NULL)
                goto cleanup;
        fname = query_newname(client, dbuf, &b);
        neg = query_newrdataset(client);
        negsig = query_newrdataset(client);
        if (fname == NULL || neg == NULL || negsig == NULL)
                goto cleanup;

        result = dns_rdataset_getnoqname(rdataset, fname, neg, negsig);
        RUNTIME_CHECK(result == ISC_R_SUCCESS);

        query_addrrset(client, &fname, &neg, &negsig, dbuf,
                       DNS_SECTION_AUTHORITY);

        if ((rdataset->attributes & DNS_RDATASETATTR_CLOSEST) == 0)
                goto cleanup;

        if (fname == NULL) {
                dbuf = query_getnamebuf(client);
                if (dbuf == NULL)
                        goto cleanup;
                fname = query_newname(client, dbuf, &b);
        }
        if (neg == NULL)
                neg = query_newrdataset(client);
        else if (dns_rdataset_isassociated(neg))
                dns_rdataset_disassociate(neg);
        if (negsig == NULL)
                negsig = query_newrdataset(client);
        else if (dns_rdataset_isassociated(negsig))
                dns_rdataset_disassociate(negsig);
        if (fname == NULL || neg == NULL || negsig == NULL)
                goto cleanup;
        result = dns_rdataset_getclosest(rdataset, fname, neg, negsig);
        RUNTIME_CHECK(result == ISC_R_SUCCESS);

        query_addrrset(client, &fname, &neg, &negsig, dbuf,
                       DNS_SECTION_AUTHORITY);

 cleanup:
        if (neg != NULL)
                query_putrdataset(client, &neg);
        if (negsig != NULL)
                query_putrdataset(client, &negsig);
        if (fname != NULL)
                query_releasename(client, &fname);
}

static inline void
answer_in_glue(ns_client_t *client, dns_rdatatype_t qtype) {
        dns_name_t *name;
        dns_message_t *msg;
        dns_section_t section = DNS_SECTION_ADDITIONAL;
        dns_rdataset_t *rdataset = NULL;

        msg = client->message;
        for (name = ISC_LIST_HEAD(msg->sections[section]);
             name != NULL;
             name = ISC_LIST_NEXT(name, link))
                if (dns_name_equal(name, client->query.qname)) {
                        for (rdataset = ISC_LIST_HEAD(name->list);
                             rdataset != NULL;
                             rdataset = ISC_LIST_NEXT(rdataset, link))
                                if (rdataset->type == qtype)
                                        break;
                        break;
                }
        if (rdataset != NULL) {
                ISC_LIST_UNLINK(msg->sections[section], name, link);
                ISC_LIST_PREPEND(msg->sections[section], name, link);
                ISC_LIST_UNLINK(name->list, rdataset, link);
                ISC_LIST_PREPEND(name->list, rdataset, link);
                rdataset->attributes |= DNS_RDATASETATTR_REQUIREDGLUE;
        }
}

#define NS_NAME_INIT(A,B) \
         { \
                DNS_NAME_MAGIC, \
                A, sizeof(A), sizeof(B), \
                DNS_NAMEATTR_READONLY | DNS_NAMEATTR_ABSOLUTE, \
                B, NULL, { (void *)-1, (void *)-1}, \
                {NULL, NULL} \
        }

static unsigned char inaddr10_offsets[] = { 0, 3, 11, 16 };
static unsigned char inaddr172_offsets[] = { 0, 3, 7, 15, 20 };
static unsigned char inaddr192_offsets[] = { 0, 4, 8, 16, 21 };

static unsigned char inaddr10[] = "\00210\007IN-ADDR\004ARPA";

static unsigned char inaddr16172[] = "\00216\003172\007IN-ADDR\004ARPA";
static unsigned char inaddr17172[] = "\00217\003172\007IN-ADDR\004ARPA";
static unsigned char inaddr18172[] = "\00218\003172\007IN-ADDR\004ARPA";
static unsigned char inaddr19172[] = "\00219\003172\007IN-ADDR\004ARPA";
static unsigned char inaddr20172[] = "\00220\003172\007IN-ADDR\004ARPA";
static unsigned char inaddr21172[] = "\00221\003172\007IN-ADDR\004ARPA";
static unsigned char inaddr22172[] = "\00222\003172\007IN-ADDR\004ARPA";
static unsigned char inaddr23172[] = "\00223\003172\007IN-ADDR\004ARPA";
static unsigned char inaddr24172[] = "\00224\003172\007IN-ADDR\004ARPA";
static unsigned char inaddr25172[] = "\00225\003172\007IN-ADDR\004ARPA";
static unsigned char inaddr26172[] = "\00226\003172\007IN-ADDR\004ARPA";
static unsigned char inaddr27172[] = "\00227\003172\007IN-ADDR\004ARPA";
static unsigned char inaddr28172[] = "\00228\003172\007IN-ADDR\004ARPA";
static unsigned char inaddr29172[] = "\00229\003172\007IN-ADDR\004ARPA";
static unsigned char inaddr30172[] = "\00230\003172\007IN-ADDR\004ARPA";
static unsigned char inaddr31172[] = "\00231\003172\007IN-ADDR\004ARPA";

static unsigned char inaddr168192[] = "\003168\003192\007IN-ADDR\004ARPA";

static dns_name_t rfc1918names[] = {
        NS_NAME_INIT(inaddr10, inaddr10_offsets),
        NS_NAME_INIT(inaddr16172, inaddr172_offsets),
        NS_NAME_INIT(inaddr17172, inaddr172_offsets),
        NS_NAME_INIT(inaddr18172, inaddr172_offsets),
        NS_NAME_INIT(inaddr19172, inaddr172_offsets),
        NS_NAME_INIT(inaddr20172, inaddr172_offsets),
        NS_NAME_INIT(inaddr21172, inaddr172_offsets),
        NS_NAME_INIT(inaddr22172, inaddr172_offsets),
        NS_NAME_INIT(inaddr23172, inaddr172_offsets),
        NS_NAME_INIT(inaddr24172, inaddr172_offsets),
        NS_NAME_INIT(inaddr25172, inaddr172_offsets),
        NS_NAME_INIT(inaddr26172, inaddr172_offsets),
        NS_NAME_INIT(inaddr27172, inaddr172_offsets),
        NS_NAME_INIT(inaddr28172, inaddr172_offsets),
        NS_NAME_INIT(inaddr29172, inaddr172_offsets),
        NS_NAME_INIT(inaddr30172, inaddr172_offsets),
        NS_NAME_INIT(inaddr31172, inaddr172_offsets),
        NS_NAME_INIT(inaddr168192, inaddr192_offsets)
};


static unsigned char prisoner_data[] = "\010prisoner\004iana\003org";
static unsigned char hostmaster_data[] = "\012hostmaster\014root-servers\003org";

static unsigned char prisoner_offsets[] = { 0, 9, 14, 18 };
static unsigned char hostmaster_offsets[] = { 0, 11, 24, 28 };

static dns_name_t prisoner = NS_NAME_INIT(prisoner_data, prisoner_offsets);
static dns_name_t hostmaster = NS_NAME_INIT(hostmaster_data, hostmaster_offsets);

static void
warn_rfc1918(ns_client_t *client, dns_name_t *fname, dns_rdataset_t *rdataset) {
        unsigned int i;
        dns_rdata_t rdata = DNS_RDATA_INIT;
        dns_rdata_soa_t soa;
        dns_rdataset_t found;
        isc_result_t result;

        for (i = 0; i < (sizeof(rfc1918names)/sizeof(*rfc1918names)); i++) {
                if (dns_name_issubdomain(fname, &rfc1918names[i])) {
                        dns_rdataset_init(&found);
                        result = dns_ncache_getrdataset(rdataset,
                                                        &rfc1918names[i],
                                                        dns_rdatatype_soa,
                                                        &found);
                        if (result != ISC_R_SUCCESS)
                                return;

                        result = dns_rdataset_first(&found);
                        RUNTIME_CHECK(result == ISC_R_SUCCESS);
                        dns_rdataset_current(&found, &rdata);
                        result = dns_rdata_tostruct(&rdata, &soa, NULL);
                        RUNTIME_CHECK(result == ISC_R_SUCCESS);
                        if (dns_name_equal(&soa.origin, &prisoner) &&
                            dns_name_equal(&soa.contact, &hostmaster)) {
                                char buf[DNS_NAME_FORMATSIZE];
                                dns_name_format(fname, buf, sizeof(buf));
                                ns_client_log(client, DNS_LOGCATEGORY_SECURITY,
                                              NS_LOGMODULE_QUERY,
                                              ISC_LOG_WARNING,
                                              "RFC 1918 response from "
                                              "Internet for %s", buf);
                        }
                        dns_rdataset_disassociate(&found);
                        return;
                }
        }
}

static void
query_findclosestnsec3(dns_name_t *qname, dns_db_t *db,
                       dns_dbversion_t *version, ns_client_t *client,
                       dns_rdataset_t *rdataset, dns_rdataset_t *sigrdataset,
                       dns_name_t *fname, isc_boolean_t exact,
                       dns_name_t *found)
{
        unsigned char salt[256];
        size_t salt_length;
        isc_uint16_t iterations;
        isc_result_t result;
        unsigned int dboptions;
        dns_fixedname_t fixed;
        dns_hash_t hash;
        dns_name_t name;
        int order;
        unsigned int count;
        dns_rdata_nsec3_t nsec3;
        dns_rdata_t rdata = DNS_RDATA_INIT;
        isc_boolean_t optout;

        salt_length = sizeof(salt);
        result = dns_db_getnsec3parameters(db, version, &hash, NULL,
                                           &iterations, salt, &salt_length);
        if (result != ISC_R_SUCCESS)
                return;

        dns_name_init(&name, NULL);
        dns_name_clone(qname, &name);

        /*
         * Map unknown algorithm to known value.
         */
        if (hash == DNS_NSEC3_UNKNOWNALG)
                hash = 1;

 again:
        dns_fixedname_init(&fixed);
        result = dns_nsec3_hashname(&fixed, NULL, NULL, &name,
                                    dns_db_origin(db), hash,
                                    iterations, salt, salt_length);
        if (result != ISC_R_SUCCESS)
                return;

        dboptions = client->query.dboptions | DNS_DBFIND_FORCENSEC3;
        result = dns_db_find(db, dns_fixedname_name(&fixed), version,
                             dns_rdatatype_nsec3, dboptions, client->now,
                             NULL, fname, rdataset, sigrdataset);

        if (result == DNS_R_NXDOMAIN) {
                if (!dns_rdataset_isassociated(rdataset)) {
                        return;
                }
                result = dns_rdataset_first(rdataset);
                INSIST(result == ISC_R_SUCCESS);
                dns_rdataset_current(rdataset, &rdata);
                dns_rdata_tostruct(&rdata, &nsec3, NULL);
                dns_rdata_reset(&rdata);
                optout = ISC_TF((nsec3.flags & DNS_NSEC3FLAG_OPTOUT) != 0);
                if (found != NULL && optout &&
                    dns_name_fullcompare(&name, dns_db_origin(db), &order,
                                         &count) == dns_namereln_subdomain) {
                        dns_rdataset_disassociate(rdataset);
                        if (dns_rdataset_isassociated(sigrdataset))
                                dns_rdataset_disassociate(sigrdataset);
                        count = dns_name_countlabels(&name) - 1;
                        dns_name_getlabelsequence(&name, 1, count, &name);
                        ns_client_log(client, DNS_LOGCATEGORY_DNSSEC,
                                      NS_LOGMODULE_QUERY, ISC_LOG_DEBUG(3),
                                      "looking for closest provable encloser");
                        goto again;
                }
                if (exact)
                        ns_client_log(client, DNS_LOGCATEGORY_DNSSEC,
                                      NS_LOGMODULE_QUERY, ISC_LOG_WARNING,
                                      "expected a exact match NSEC3, got "
                                      "a covering record");

        } else if (result != ISC_R_SUCCESS) {
                return;
        } else if (!exact)
                ns_client_log(client, DNS_LOGCATEGORY_DNSSEC,
                              NS_LOGMODULE_QUERY, ISC_LOG_WARNING,
                              "expected covering NSEC3, got an exact match");
        if (found != NULL)
                dns_name_copy(&name, found, NULL);
        return;
}

/*
 * Do the bulk of query processing for the current query of 'client'.
 * If 'event' is non-NULL, we are returning from recursion and 'qtype'
 * is ignored.  Otherwise, 'qtype' is the query type.
 */
static isc_result_t
query_find(ns_client_t *client, dns_fetchevent_t *event, dns_rdatatype_t qtype)
{
        dns_db_t *db, *zdb;
        dns_dbnode_t *node;
        dns_rdatatype_t type;
        dns_name_t *fname, *zfname, *tname, *prefix;
        dns_rdataset_t *rdataset, *trdataset;
        dns_rdataset_t *sigrdataset, *zrdataset, *zsigrdataset;
        dns_rdataset_t **sigrdatasetp;
        dns_rdata_t rdata = DNS_RDATA_INIT;
        dns_rdatasetiter_t *rdsiter;
        isc_boolean_t want_restart, authoritative, is_zone, need_wildcardproof;
        unsigned int n, nlabels;
        dns_namereln_t namereln;
        int order;
        isc_buffer_t *dbuf;
        isc_buffer_t b;
        isc_result_t result, eresult;
        dns_fixedname_t fixed;
        dns_fixedname_t wildcardname;
        dns_dbversion_t *version, *zversion;
        dns_zone_t *zone;
        dns_rdata_cname_t cname;
        dns_rdata_dname_t dname;
        unsigned int options;
        isc_boolean_t empty_wild;
        dns_rdataset_t *noqname;
        isc_boolean_t resuming;
        int line = -1;
        dns_rdataset_t tmprdataset;
        unsigned int dboptions;

        CTRACE("query_find");

        /*
         * One-time initialization.
         *
         * It's especially important to initialize anything that the cleanup
         * code might cleanup.
         */

        eresult = ISC_R_SUCCESS;
        fname = NULL;
        zfname = NULL;
        rdataset = NULL;
        zrdataset = NULL;
        sigrdataset = NULL;
        zsigrdataset = NULL;
        zversion = NULL;
        node = NULL;
        db = NULL;
        zdb = NULL;
        version = NULL;
        zone = NULL;
        need_wildcardproof = ISC_FALSE;
        empty_wild = ISC_FALSE;
        options = 0;
        resuming = ISC_FALSE;
        is_zone = ISC_FALSE;

        if (event != NULL) {
                /*
                 * We're returning from recursion.  Restore the query context
                 * and resume.
                 */

                want_restart = ISC_FALSE;
                authoritative = ISC_FALSE;

                qtype = event->qtype;
                if (qtype == dns_rdatatype_rrsig || qtype == dns_rdatatype_sig)
                        type = dns_rdatatype_any;
                else
                        type = qtype;
                db = event->db;
                node = event->node;
                rdataset = event->rdataset;
                sigrdataset = event->sigrdataset;

                /*
                 * We'll need some resources...
                 */
                dbuf = query_getnamebuf(client);
                if (dbuf == NULL) {
                        QUERY_ERROR(DNS_R_SERVFAIL);
                        goto cleanup;
                }
                fname = query_newname(client, dbuf, &b);
                if (fname == NULL) {
                        QUERY_ERROR(DNS_R_SERVFAIL);
                        goto cleanup;
                }
                tname = dns_fixedname_name(&event->foundname);
                result = dns_name_copy(tname, fname, NULL);
                if (result != ISC_R_SUCCESS) {
                        QUERY_ERROR(DNS_R_SERVFAIL);
                        goto cleanup;
                }

                result = event->result;
                resuming = ISC_TRUE;

                goto resume;
        }

        /*
         * Not returning from recursion.
         */

        /*
         * If it's a SIG query, we'll iterate the node.
         */
        if (qtype == dns_rdatatype_rrsig || qtype == dns_rdatatype_sig)
                type = dns_rdatatype_any;
        else
                type = qtype;

 restart:
        CTRACE("query_find: restart");
        want_restart = ISC_FALSE;
        authoritative = ISC_FALSE;
        version = NULL;
        need_wildcardproof = ISC_FALSE;

        if (client->view->checknames &&
            !dns_rdata_checkowner(client->query.qname,
                                  client->message->rdclass,
                                  qtype, ISC_FALSE)) {
                char namebuf[DNS_NAME_FORMATSIZE];
                char typename[DNS_RDATATYPE_FORMATSIZE];
                char classname[DNS_RDATACLASS_FORMATSIZE];

                dns_name_format(client->query.qname, namebuf, sizeof(namebuf));
                dns_rdatatype_format(qtype, typename, sizeof(typename));
                dns_rdataclass_format(client->message->rdclass, classname,
                                      sizeof(classname));
                ns_client_log(client, DNS_LOGCATEGORY_SECURITY,
                              NS_LOGMODULE_QUERY, ISC_LOG_ERROR,
                              "check-names failure %s/%s/%s", namebuf,
                              typename, classname);
                QUERY_ERROR(DNS_R_REFUSED);
                goto cleanup;
        }

        /*
         * First we must find the right database.
         */
        options &= DNS_GETDB_NOLOG; /* Preserve DNS_GETDB_NOLOG. */
        if (dns_rdatatype_atparent(qtype) &&
            !dns_name_equal(client->query.qname, dns_rootname))
                options |= DNS_GETDB_NOEXACT;
        result = query_getdb(client, client->query.qname, qtype, options,
                             &zone, &db, &version, &is_zone);
        if ((result != ISC_R_SUCCESS || !is_zone) && !RECURSIONOK(client) &&
            (options & DNS_GETDB_NOEXACT) != 0 && qtype == dns_rdatatype_ds) {
                /*
                 * Look to see if we are authoritative for the
                 * child zone if the query type is DS.
                 */
                dns_db_t *tdb = NULL;
                dns_zone_t *tzone = NULL;
                dns_dbversion_t *tversion = NULL;
                isc_result_t tresult;

                tresult = query_getzonedb(client, client->query.qname, qtype,
                                         DNS_GETDB_PARTIAL, &tzone, &tdb,
                                         &tversion);
                if (tresult == ISC_R_SUCCESS) {
                        options &= ~DNS_GETDB_NOEXACT;
                        query_putrdataset(client, &rdataset);
                        if (db != NULL)
                                dns_db_detach(&db);
                        if (zone != NULL)
                                dns_zone_detach(&zone);
                        version = tversion;
                        db = tdb;
                        zone = tzone;
                        is_zone = ISC_TRUE;
                        result = ISC_R_SUCCESS;
                } else {
                        if (tdb != NULL)
                                dns_db_detach(&tdb);
                        if (tzone != NULL)
                                dns_zone_detach(&tzone);
                }
        }
        if (result != ISC_R_SUCCESS) {
                if (result == DNS_R_REFUSED) {
                        if (WANTRECURSION(client)) {
                                inc_stats(client,
                                          dns_nsstatscounter_recurserej);
                        } else
                                inc_stats(client, dns_nsstatscounter_authrej);
                        if (!PARTIALANSWER(client))
                                QUERY_ERROR(DNS_R_REFUSED);
                } else
                        QUERY_ERROR(DNS_R_SERVFAIL);
                goto cleanup;
        }

        if (is_zone)
                authoritative = ISC_TRUE;

        if (event == NULL && client->query.restarts == 0) {
                if (is_zone) {
#ifdef DLZ
                        if (zone != NULL) {
                                /*
                                 * if is_zone = true, zone = NULL then this is
                                 * a DLZ zone.  Don't attempt to attach zone.
                                 */
#endif
                                dns_zone_attach(zone, &client->query.authzone);
#ifdef DLZ
                        }
#endif
                        dns_db_attach(db, &client->query.authdb);
                }
                client->query.authdbset = ISC_TRUE;
        }

 db_find:
        CTRACE("query_find: db_find");
        /*
         * We'll need some resources...
         */
        dbuf = query_getnamebuf(client);
        if (dbuf == NULL) {
                QUERY_ERROR(DNS_R_SERVFAIL);
                goto cleanup;
        }
        fname = query_newname(client, dbuf, &b);
        rdataset = query_newrdataset(client);
        if (fname == NULL || rdataset == NULL) {
                QUERY_ERROR(DNS_R_SERVFAIL);
                goto cleanup;
        }
        if (WANTDNSSEC(client) && (!is_zone || dns_db_issecure(db))) {
                sigrdataset = query_newrdataset(client);
                if (sigrdataset == NULL) {
                        QUERY_ERROR(DNS_R_SERVFAIL);
                        goto cleanup;
                }
        }

        /*
         * Now look for an answer in the database.
         */
        dboptions = client->query.dboptions;
        if (sigrdataset == NULL && client->view->enablednssec) {
                /*
                 * If the client doesn't want DNSSEC we still want to
                 * look for any data pending validation to save a remote
                 * lookup if possible.
                 */
                dns_rdataset_init(&tmprdataset);
                sigrdataset = &tmprdataset;
                dboptions |= DNS_DBFIND_PENDINGOK;
        }
 refind:
        result = dns_db_find(db, client->query.qname, version, type,
                             dboptions, client->now, &node, fname,
                             rdataset, sigrdataset);
        /*
         * If we have found pending data try to validate it.
         * If the data does not validate as secure and we can't
         * use the unvalidated data requery the database with
         * pending disabled to prevent infinite looping.
         */
        if (result != ISC_R_SUCCESS || !DNS_TRUST_PENDING(rdataset->trust))
                goto validation_done;
        if (validate(client, db, fname, rdataset, sigrdataset))
                goto validation_done;
        if (rdataset->trust != dns_trust_pending_answer ||
            !PENDINGOK(client->query.dboptions)) {
                dns_rdataset_disassociate(rdataset);
                if (sigrdataset != NULL &&
                    dns_rdataset_isassociated(sigrdataset))
                        dns_rdataset_disassociate(sigrdataset);
                if (sigrdataset == &tmprdataset)
                        sigrdataset = NULL;
                dns_db_detachnode(db, &node);
                dboptions &= ~DNS_DBFIND_PENDINGOK;
                goto refind;
        }
 validation_done:
        if (sigrdataset == &tmprdataset) {
                if (dns_rdataset_isassociated(sigrdataset))
                        dns_rdataset_disassociate(sigrdataset);
                sigrdataset = NULL;
        }

 resume:
        CTRACE("query_find: resume");
        switch (result) {
        case ISC_R_SUCCESS:
                /*
                 * This case is handled in the main line below.
                 */
                break;
        case DNS_R_GLUE:
        case DNS_R_ZONECUT:
                /*
                 * These cases are handled in the main line below.
                 */
                INSIST(is_zone);
                authoritative = ISC_FALSE;
                break;
        case ISC_R_NOTFOUND:
                /*
                 * The cache doesn't even have the root NS.  Get them from
                 * the hints DB.
                 */
                INSIST(!is_zone);
                if (db != NULL)
                        dns_db_detach(&db);

                if (client->view->hints == NULL) {
                        /* We have no hints. */
                        result = ISC_R_FAILURE;
                } else {
                        dns_db_attach(client->view->hints, &db);
                        result = dns_db_find(db, dns_rootname,
                                             NULL, dns_rdatatype_ns,
                                             0, client->now, &node, fname,
                                             rdataset, sigrdataset);
                }
                if (result != ISC_R_SUCCESS) {
                        /*
                         * Nonsensical root hints may require cleanup.
                         */
                        if (dns_rdataset_isassociated(rdataset))
                                dns_rdataset_disassociate(rdataset);
                        if (sigrdataset != NULL &&
                            dns_rdataset_isassociated(sigrdataset))
                                dns_rdataset_disassociate(sigrdataset);
                        if (node != NULL)
                                dns_db_detachnode(db, &node);

                        /*
                         * We don't have any root server hints, but
                         * we may have working forwarders, so try to
                         * recurse anyway.
                         */
                        if (RECURSIONOK(client)) {
                                result = query_recurse(client, qtype,
                                                       NULL, NULL, resuming);
                                if (result == ISC_R_SUCCESS)
                                        client->query.attributes |=
                                                NS_QUERYATTR_RECURSING;
                                else
                                        RECURSE_ERROR(result);
                                goto cleanup;
                        } else {
                                /* Unable to give root server referral. */
                                QUERY_ERROR(DNS_R_SERVFAIL);
                                goto cleanup;
                        }
                }
                /*
                 * XXXRTH  We should trigger root server priming here.
                 */
                /* FALLTHROUGH */
        case DNS_R_DELEGATION:
                authoritative = ISC_FALSE;
                if (is_zone) {
                        /*
                         * Look to see if we are authoritative for the
                         * child zone if the query type is DS.
                         */
                        if (!RECURSIONOK(client) &&
                            (options & DNS_GETDB_NOEXACT) != 0 &&
                            qtype == dns_rdatatype_ds) {
                                dns_db_t *tdb = NULL;
                                dns_zone_t *tzone = NULL;
                                dns_dbversion_t *tversion = NULL;
                                result = query_getzonedb(client,
                                                         client->query.qname,
                                                         qtype,
                                                         DNS_GETDB_PARTIAL,
                                                         &tzone, &tdb,
                                                         &tversion);
                                if (result == ISC_R_SUCCESS) {
                                        options &= ~DNS_GETDB_NOEXACT;
                                        query_putrdataset(client, &rdataset);
                                        if (sigrdataset != NULL)
                                                query_putrdataset(client,
                                                                  &sigrdataset);
                                        if (fname != NULL)
                                                query_releasename(client,
                                                                  &fname);
                                        if (node != NULL)
                                                dns_db_detachnode(db, &node);
                                        if (db != NULL)
                                                dns_db_detach(&db);
                                        if (zone != NULL)
                                                dns_zone_detach(&zone);
                                        version = tversion;
                                        db = tdb;
                                        zone = tzone;
                                        authoritative = ISC_TRUE;
                                        goto db_find;
                                }
                                if (tdb != NULL)
                                        dns_db_detach(&tdb);
                                if (tzone != NULL)
                                        dns_zone_detach(&tzone);
                        }
                        /*
                         * We're authoritative for an ancestor of QNAME.
                         */
                        if (!USECACHE(client) || !RECURSIONOK(client)) {
                                dns_fixedname_t fixed;

                                dns_fixedname_init(&fixed);
                                dns_name_copy(fname,
                                              dns_fixedname_name(&fixed), NULL);

                                /*
                                 * If we don't have a cache, this is the best
                                 * answer.
                                 *
                                 * If the client is making a nonrecursive
                                 * query we always give out the authoritative
                                 * delegation.  This way even if we get
                                 * junk in our cache, we won't fail in our
                                 * role as the delegating authority if another
                                 * nameserver asks us about a delegated
                                 * subzone.
                                 *
                                 * We enable the retrieval of glue for this
                                 * database by setting client->query.gluedb.
                                 */
                                client->query.gluedb = db;
                                client->query.isreferral = ISC_TRUE;
                                /*
                                 * We must ensure NOADDITIONAL is off,
                                 * because the generation of
                                 * additional data is required in
                                 * delegations.
                                 */
                                client->query.attributes &=
                                        ~NS_QUERYATTR_NOADDITIONAL;
                                if (sigrdataset != NULL)
                                        sigrdatasetp = &sigrdataset;
                                else
                                        sigrdatasetp = NULL;
                                query_addrrset(client, &fname,
                                               &rdataset, sigrdatasetp,
                                               dbuf, DNS_SECTION_AUTHORITY);
                                client->query.gluedb = NULL;
                                if (WANTDNSSEC(client))
                                        query_addds(client, db, node, version,
                                                   dns_fixedname_name(&fixed));
                        } else {
                                /*
                                 * We might have a better answer or delegation
                                 * in the cache.  We'll remember the current
                                 * values of fname, rdataset, and sigrdataset.
                                 * We'll then go looking for QNAME in the
                                 * cache.  If we find something better, we'll
                                 * use it instead.
                                 */
                                query_keepname(client, fname, dbuf);
                                zdb = db;
                                zfname = fname;
                                fname = NULL;
                                zrdataset = rdataset;
                                rdataset = NULL;
                                zsigrdataset = sigrdataset;
                                sigrdataset = NULL;
                                dns_db_detachnode(db, &node);
                                zversion = version;
                                version = NULL;
                                db = NULL;
                                dns_db_attach(client->view->cachedb, &db);
                                is_zone = ISC_FALSE;
                                goto db_find;
                        }
                } else {
                        if (zfname != NULL &&
                            !dns_name_issubdomain(fname, zfname)) {
                                /*
                                 * We've already got a delegation from
                                 * authoritative data, and it is better
                                 * than what we found in the cache.  Use
                                 * it instead of the cache delegation.
                                 */
                                query_releasename(client, &fname);
                                fname = zfname;
                                zfname = NULL;
                                /*
                                 * We've already done query_keepname() on
                                 * zfname, so we must set dbuf to NULL to
                                 * prevent query_addrrset() from trying to
                                 * call query_keepname() again.
                                 */
                                dbuf = NULL;
                                query_putrdataset(client, &rdataset);
                                if (sigrdataset != NULL)
                                        query_putrdataset(client,
                                                          &sigrdataset);
                                rdataset = zrdataset;
                                zrdataset = NULL;
                                sigrdataset = zsigrdataset;
                                zsigrdataset = NULL;
                                version = zversion;
                                zversion = NULL;
                                /*
                                 * We don't clean up zdb here because we
                                 * may still need it.  It will get cleaned
                                 * up by the main cleanup code.
                                 */
                        }

                        if (RECURSIONOK(client)) {
                                /*
                                 * Recurse!
                                 */
                                if (dns_rdatatype_atparent(type))
                                        result = query_recurse(client, qtype,
                                                               NULL, NULL,
                                                               resuming);
                                else
                                        result = query_recurse(client, qtype,
                                                               fname, rdataset,
                                                               resuming);
                                if (result == ISC_R_SUCCESS)
                                        client->query.attributes |=
                                                NS_QUERYATTR_RECURSING;
                                else
                                        RECURSE_ERROR(result);
                        } else {
                                dns_fixedname_t fixed;

                                dns_fixedname_init(&fixed);
                                dns_name_copy(fname,
                                              dns_fixedname_name(&fixed), NULL);
                                /*
                                 * This is the best answer.
                                 */
                                client->query.attributes |=
                                        NS_QUERYATTR_CACHEGLUEOK;
                                client->query.gluedb = zdb;
                                client->query.isreferral = ISC_TRUE;
                                /*
                                 * We must ensure NOADDITIONAL is off,
                                 * because the generation of
                                 * additional data is required in
                                 * delegations.
                                 */
                                client->query.attributes &=
                                        ~NS_QUERYATTR_NOADDITIONAL;
                                if (sigrdataset != NULL)
                                        sigrdatasetp = &sigrdataset;
                                else
                                        sigrdatasetp = NULL;
                                query_addrrset(client, &fname,
                                               &rdataset, sigrdatasetp,
                                               dbuf, DNS_SECTION_AUTHORITY);
                                client->query.gluedb = NULL;
                                client->query.attributes &=
                                        ~NS_QUERYATTR_CACHEGLUEOK;
                                if (WANTDNSSEC(client))
                                        query_addds(client, db, node, version,
                                                   dns_fixedname_name(&fixed));
                        }
                }
                goto cleanup;
        case DNS_R_EMPTYNAME:
                result = DNS_R_NXRRSET;
                /* FALLTHROUGH */
        case DNS_R_NXRRSET:
                INSIST(is_zone);
                /*
                 * Look for a NSEC3 record if we don't have a NSEC record.
                 */
                if (!dns_rdataset_isassociated(rdataset) &&
                     WANTDNSSEC(client)) {
                        if ((fname->attributes & DNS_NAMEATTR_WILDCARD) == 0) {
                                dns_name_t *found;
                                dns_name_t *qname;

                                dns_fixedname_init(&fixed);
                                found = dns_fixedname_name(&fixed);
                                qname = client->query.qname;

                                query_findclosestnsec3(qname, db, version,
                                                       client, rdataset,
                                                       sigrdataset, fname,
                                                       ISC_TRUE, found);
                                /*
                                 * Did we find the closest provable encloser
                                 * instead? If so add the nearest to the
                                 * closest provable encloser.
                                 */
                                if (found &&
                                    dns_rdataset_isassociated(rdataset) &&
                                    !dns_name_equal(qname, found))
                                {
                                        unsigned int count;
                                        unsigned int skip;

                                        /*
                                         * Add the closest provable encloser.
                                         */
                                        query_addrrset(client, &fname,
                                                       &rdataset, &sigrdataset,
                                                       dbuf,
                                                       DNS_SECTION_AUTHORITY);

                                        count = dns_name_countlabels(found)
                                                         + 1;
                                        skip = dns_name_countlabels(qname) -
                                                         count;
                                        dns_name_getlabelsequence(qname, skip,
                                                                  count,
                                                                  found);

                                        fixfname(client, &fname, &dbuf, &b);
                                        fixrdataset(client, &rdataset);
                                        fixrdataset(client, &sigrdataset);
                                        if (fname == NULL ||
                                            rdataset == NULL ||
                                            sigrdataset == NULL) {
                                                QUERY_ERROR(DNS_R_SERVFAIL);
                                                goto cleanup;
                                        }
                                        /*
                                         * 'nearest' doesn't exist so
                                         * 'exist' is set to ISC_FALSE.
                                         */
                                        query_findclosestnsec3(found, db,
                                                               version,
                                                               client,
                                                               rdataset,
                                                               sigrdataset,
                                                               fname,
                                                               ISC_FALSE,
                                                               NULL);
                                }
                        } else {
                                query_releasename(client, &fname);
                                query_addwildcardproof(client, db, version,
                                                       client->query.qname,
                                                       ISC_FALSE);
                        }
                }
                if (dns_rdataset_isassociated(rdataset)) {
                        /*
                         * If we've got a NSEC record, we need to save the
                         * name now because we're going call query_addsoa()
                         * below, and it needs to use the name buffer.
                         */
                        query_keepname(client, fname, dbuf);
                } else if (fname != NULL) {
                        /*
                         * We're not going to use fname, and need to release
                         * our hold on the name buffer so query_addsoa()
                         * may use it.
                         */
                        query_releasename(client, &fname);
                }
                /*
                 * Add SOA.
                 */
                result = query_addsoa(client, db, version, ISC_FALSE);
                if (result != ISC_R_SUCCESS) {
                        QUERY_ERROR(result);
                        goto cleanup;
                }
                /*
                 * Add NSEC record if we found one.
                 */
                if (WANTDNSSEC(client)) {
                        if (dns_rdataset_isassociated(rdataset))
                                query_addnxrrsetnsec(client, db, version,
                                                     &fname, &rdataset,
                                                     &sigrdataset);
                }
                goto cleanup;

        case DNS_R_EMPTYWILD:
                empty_wild = ISC_TRUE;
                /* FALLTHROUGH */

        case DNS_R_NXDOMAIN:
                INSIST(is_zone);
                if (dns_rdataset_isassociated(rdataset)) {
                        /*
                         * If we've got a NSEC record, we need to save the
                         * name now because we're going call query_addsoa()
                         * below, and it needs to use the name buffer.
                         */
                        query_keepname(client, fname, dbuf);
                } else if (fname != NULL) {
                        /*
                         * We're not going to use fname, and need to release
                         * our hold on the name buffer so query_addsoa()
                         * may use it.
                         */
                        query_releasename(client, &fname);
                }
                /*
                 * Add SOA.  If the query was for a SOA record force the
                 * ttl to zero so that it is possible for clients to find
                 * the containing zone of an arbitrary name with a stub
                 * resolver and not have it cached.
                 */
                if (qtype == dns_rdatatype_soa &&
#ifdef DLZ
                    zone != NULL &&
#endif
                    dns_zone_getzeronosoattl(zone))
                        result = query_addsoa(client, db, version, ISC_TRUE);
                else
                        result = query_addsoa(client, db, version, ISC_FALSE);
                if (result != ISC_R_SUCCESS) {
                        QUERY_ERROR(result);
                        goto cleanup;
                }

                if (WANTDNSSEC(client)) {
                        /*
                         * Add NSEC record if we found one.
                         */
                        if (dns_rdataset_isassociated(rdataset))
                                query_addrrset(client, &fname, &rdataset,
                                               &sigrdataset,
                                               NULL, DNS_SECTION_AUTHORITY);
                        query_addwildcardproof(client, db, version,
                                               client->query.qname, ISC_FALSE);
                }

                /*
                 * Set message rcode.
                 */
                if (empty_wild)
                        client->message->rcode = dns_rcode_noerror;
                else
                        client->message->rcode = dns_rcode_nxdomain;
                goto cleanup;

        case DNS_R_NCACHENXDOMAIN:
        case DNS_R_NCACHENXRRSET:
                INSIST(!is_zone);
                authoritative = ISC_FALSE;
                /*
                 * Set message rcode, if required.
                 */
                if (result == DNS_R_NCACHENXDOMAIN)
                        client->message->rcode = dns_rcode_nxdomain;
                /*
                 * Look for RFC 1918 leakage from Internet.
                 */
                if (result == DNS_R_NCACHENXDOMAIN &&
                    qtype == dns_rdatatype_ptr &&
                    client->message->rdclass == dns_rdataclass_in &&
                    dns_name_countlabels(fname) == 7)
                        warn_rfc1918(client, fname, rdataset);
                /*
                 * We don't call query_addrrset() because we don't need any
                 * of its extra features (and things would probably break!).
                 */
                query_keepname(client, fname, dbuf);
                dns_message_addname(client->message, fname,
                                    DNS_SECTION_AUTHORITY);
                ISC_LIST_APPEND(fname->list, rdataset, link);
                fname = NULL;
                rdataset = NULL;
                goto cleanup;

        case DNS_R_CNAME:
                /*
                 * Keep a copy of the rdataset.  We have to do this because
                 * query_addrrset may clear 'rdataset' (to prevent the
                 * cleanup code from cleaning it up).
                 */
                trdataset = rdataset;
                /*
                 * Add the CNAME to the answer section.
                 */
                if (sigrdataset != NULL)
                        sigrdatasetp = &sigrdataset;
                else
                        sigrdatasetp = NULL;
                if (WANTDNSSEC(client) &&
                    (fname->attributes & DNS_NAMEATTR_WILDCARD) != 0)
                {
                        dns_fixedname_init(&wildcardname);
                        dns_name_copy(fname, dns_fixedname_name(&wildcardname),
                                      NULL);
                        need_wildcardproof = ISC_TRUE;
                }
                if (NOQNAME(rdataset) && WANTDNSSEC(client))
                        noqname = rdataset;
                else
                        noqname = NULL;
                query_addrrset(client, &fname, &rdataset, sigrdatasetp, dbuf,
                               DNS_SECTION_ANSWER);
                if (noqname != NULL)
                        query_addnoqnameproof(client, noqname);
                /*
                 * We set the PARTIALANSWER attribute so that if anything goes
                 * wrong later on, we'll return what we've got so far.
                 */
                client->query.attributes |= NS_QUERYATTR_PARTIALANSWER;
                /*
                 * Reset qname to be the target name of the CNAME and restart
                 * the query.
                 */
                tname = NULL;
                result = dns_message_gettempname(client->message, &tname);
                if (result != ISC_R_SUCCESS)
                        goto cleanup;
                result = dns_rdataset_first(trdataset);
                if (result != ISC_R_SUCCESS) {
                        dns_message_puttempname(client->message, &tname);
                        goto cleanup;
                }
                dns_rdataset_current(trdataset, &rdata);
                result = dns_rdata_tostruct(&rdata, &cname, NULL);
                dns_rdata_reset(&rdata);
                if (result != ISC_R_SUCCESS) {
                        dns_message_puttempname(client->message, &tname);
                        goto cleanup;
                }
                dns_name_init(tname, NULL);
                result = dns_name_dup(&cname.cname, client->mctx, tname);
                if (result != ISC_R_SUCCESS) {
                        dns_message_puttempname(client->message, &tname);
                        dns_rdata_freestruct(&cname);
                        goto cleanup;
                }
                dns_rdata_freestruct(&cname);
                ns_client_qnamereplace(client, tname);
                want_restart = ISC_TRUE;
                if (!WANTRECURSION(client))
                        options |= DNS_GETDB_NOLOG;
                goto addauth;
        case DNS_R_DNAME:
                /*
                 * Compare the current qname to the found name.  We need
                 * to know how many labels and bits are in common because
                 * we're going to have to split qname later on.
                 */
                namereln = dns_name_fullcompare(client->query.qname, fname,
                                                &order, &nlabels);
                INSIST(namereln == dns_namereln_subdomain);
                /*
                 * Keep a copy of the rdataset.  We have to do this because
                 * query_addrrset may clear 'rdataset' (to prevent the
                 * cleanup code from cleaning it up).
                 */
                trdataset = rdataset;
                /*
                 * Add the DNAME to the answer section.
                 */
                if (sigrdataset != NULL)
                        sigrdatasetp = &sigrdataset;
                else
                        sigrdatasetp = NULL;
                if (WANTDNSSEC(client) &&
                    (fname->attributes & DNS_NAMEATTR_WILDCARD) != 0)
                {
                        dns_fixedname_init(&wildcardname);
                        dns_name_copy(fname, dns_fixedname_name(&wildcardname),
                                      NULL);
                        need_wildcardproof = ISC_TRUE;
                }
                query_addrrset(client, &fname, &rdataset, sigrdatasetp, dbuf,
                               DNS_SECTION_ANSWER);
                /*
                 * We set the PARTIALANSWER attribute so that if anything goes
                 * wrong later on, we'll return what we've got so far.
                 */
                client->query.attributes |= NS_QUERYATTR_PARTIALANSWER;
                /*
                 * Get the target name of the DNAME.
                 */
                tname = NULL;
                result = dns_message_gettempname(client->message, &tname);
                if (result != ISC_R_SUCCESS)
                        goto cleanup;
                result = dns_rdataset_first(trdataset);
                if (result != ISC_R_SUCCESS) {
                        dns_message_puttempname(client->message, &tname);
                        goto cleanup;
                }
                dns_rdataset_current(trdataset, &rdata);
                result = dns_rdata_tostruct(&rdata, &dname, NULL);
                dns_rdata_reset(&rdata);
                if (result != ISC_R_SUCCESS) {
                        dns_message_puttempname(client->message, &tname);
                        goto cleanup;
                }
                dns_name_init(tname, NULL);
                dns_name_clone(&dname.dname, tname);
                dns_rdata_freestruct(&dname);
                /*
                 * Construct the new qname.
                 */
                dns_fixedname_init(&fixed);
                prefix = dns_fixedname_name(&fixed);
                dns_name_split(client->query.qname, nlabels, prefix, NULL);
                INSIST(fname == NULL);
                dbuf = query_getnamebuf(client);
                if (dbuf == NULL) {
                        dns_message_puttempname(client->message, &tname);
                        goto cleanup;
                }
                fname = query_newname(client, dbuf, &b);
                if (fname == NULL) {
                        dns_message_puttempname(client->message, &tname);
                        goto cleanup;
                }
                result = dns_name_concatenate(prefix, tname, fname, NULL);
                if (result != ISC_R_SUCCESS) {
                        dns_message_puttempname(client->message, &tname);
                        if (result == ISC_R_NOSPACE) {
                                /*
                                 * RFC2672, section 4.1, subsection 3c says
                                 * we should return YXDOMAIN if the constructed
                                 * name would be too long.
                                 */
                                client->message->rcode = dns_rcode_yxdomain;
                        }
                        goto cleanup;
                }
                query_keepname(client, fname, dbuf);
                /*
                 * Synthesize a CNAME for this DNAME.
                 *
                 * We want to synthesize a CNAME since if we don't
                 * then older software that doesn't understand DNAME
                 * will not chain like it should.
                 *
                 * We do not try to synthesize a signature because we hope
                 * that security aware servers will understand DNAME.  Also,
                 * even if we had an online key, making a signature
                 * on-the-fly is costly, and not really legitimate anyway
                 * since the synthesized CNAME is NOT in the zone.
                 */
                dns_name_init(tname, NULL);
                (void)query_addcnamelike(client, client->query.qname, fname,
                                         trdataset, &tname,
                                         dns_rdatatype_cname);
                if (tname != NULL)
                        dns_message_puttempname(client->message, &tname);
                /*
                 * Switch to the new qname and restart.
                 */
                ns_client_qnamereplace(client, fname);
                fname = NULL;
                want_restart = ISC_TRUE;
                if (!WANTRECURSION(client))
                        options |= DNS_GETDB_NOLOG;
                goto addauth;
        default:
                /*
                 * Something has gone wrong.
                 */
                QUERY_ERROR(DNS_R_SERVFAIL);
                goto cleanup;
        }

        if (WANTDNSSEC(client) &&
            (fname->attributes & DNS_NAMEATTR_WILDCARD) != 0)
        {
                dns_fixedname_init(&wildcardname);
                dns_name_copy(fname, dns_fixedname_name(&wildcardname), NULL);
                need_wildcardproof = ISC_TRUE;
        }

        if (type == dns_rdatatype_any) {
#ifdef ALLOW_FILTER_AAAA_ON_V4
                isc_boolean_t have_aaaa, have_a, have_sig;

                /*
                 * The filter-aaaa-on-v4 option should
                 * suppress AAAAs for IPv4 clients if there is an A.
                 * If we are not authoritative, assume there is a A
                 * even in if it is not in our cache.  This assumption could
                 * be wrong but it is a good bet.
                 */
                have_aaaa = ISC_FALSE;
                have_a = !authoritative;
                have_sig = ISC_FALSE;
#endif
                /*
                 * XXXRTH  Need to handle zonecuts with special case
                 * code.
                 */
                n = 0;
                rdsiter = NULL;
                result = dns_db_allrdatasets(db, node, version, 0, &rdsiter);
                if (result != ISC_R_SUCCESS) {
                        QUERY_ERROR(DNS_R_SERVFAIL);
                        goto cleanup;
                }
                /*
                 * Calling query_addrrset() with a non-NULL dbuf is going
                 * to either keep or release the name.  We don't want it to
                 * release fname, since we may have to call query_addrrset()
                 * more than once.  That means we have to call query_keepname()
                 * now, and pass a NULL dbuf to query_addrrset().
                 *
                 * If we do a query_addrrset() below, we must set fname to
                 * NULL before leaving this block, otherwise we might try to
                 * cleanup fname even though we're using it!
                 */
                query_keepname(client, fname, dbuf);
                tname = fname;
                result = dns_rdatasetiter_first(rdsiter);
                while (result == ISC_R_SUCCESS) {
                        dns_rdatasetiter_current(rdsiter, rdataset);
#ifdef ALLOW_FILTER_AAAA_ON_V4
                        /*
                         * Notice the presence of A and AAAAs so
                         * that AAAAs can be hidden from IPv4 clients.
                         */
                        if (client->view->v4_aaaa != dns_v4_aaaa_ok &&
                            client->peeraddr_valid &&
                            client->peeraddr.type.sa.sa_family == AF_INET) {
                                if (rdataset->type == dns_rdatatype_aaaa)
                                        have_aaaa = ISC_TRUE;
                                else if (rdataset->type == dns_rdatatype_a)
                                        have_a = ISC_TRUE;
                        }
#endif
                        if (is_zone && qtype == dns_rdatatype_any &&
                            !dns_db_issecure(db) &&
                            dns_rdatatype_isdnssec(rdataset->type)) {
                                /*
                                 * The zone is transitioning from insecure
                                 * to secure. Hide the dnssec records from
                                 * ANY queries.
                                 */
                                dns_rdataset_disassociate(rdataset);
                        } else if ((qtype == dns_rdatatype_any ||
                             rdataset->type == qtype) && rdataset->type != 0) {
#ifdef ALLOW_FILTER_AAAA_ON_V4
                                if (dns_rdatatype_isdnssec(rdataset->type))
                                        have_sig = ISC_TRUE;
#endif
                                if (NOQNAME(rdataset) && WANTDNSSEC(client))
                                        noqname = rdataset;
                                else
                                        noqname = NULL;
                                query_addrrset(client,
                                               fname != NULL ? &fname : &tname,
                                               &rdataset, NULL,
                                               NULL, DNS_SECTION_ANSWER);
                                if (noqname != NULL)
                                        query_addnoqnameproof(client, noqname);
                                n++;
                                INSIST(tname != NULL);
                                /*
                                 * rdataset is non-NULL only in certain
                                 * pathological cases involving DNAMEs.
                                 */
                                if (rdataset != NULL)
                                        query_putrdataset(client, &rdataset);
                                rdataset = query_newrdataset(client);
                                if (rdataset == NULL)
                                        break;
                        } else {
                                /*
                                 * We're not interested in this rdataset.
                                 */
                                dns_rdataset_disassociate(rdataset);
                        }
                        result = dns_rdatasetiter_next(rdsiter);
                }

#ifdef ALLOW_FILTER_AAAA_ON_V4
                /*
                 * Filter AAAAs if there is an A and there is no signature
                 * or we are supposed to break DNSSEC.
                 */
                if (have_aaaa && have_a &&
                    (!have_sig || !WANTDNSSEC(client) ||
                     client->view->v4_aaaa == dns_v4_aaaa_break_dnssec))
                        client->attributes |= NS_CLIENTATTR_FILTER_AAAA;
#endif
                if (fname != NULL)
                        dns_message_puttempname(client->message, &fname);

                if (n == 0 && is_zone) {
                        /*
                         * We didn't match any rdatasets.
                         */
                        if (qtype == dns_rdatatype_rrsig &&
                            result == ISC_R_NOMORE) {
                                /*
                                 * XXXRTH  If this is a secure zone and we
                                 * didn't find any SIGs, we should generate
                                 * an error unless we were searching for
                                 * glue.  Ugh.
                                 */
                                if (!is_zone) {
                                        authoritative = ISC_FALSE;
                                        dns_rdatasetiter_destroy(&rdsiter);
                                        if (RECURSIONOK(client)) {
                                                result = query_recurse(client,
                                                                       qtype,
                                                                       NULL,
                                                                       NULL,
                                                                       resuming);
                                                if (result == ISC_R_SUCCESS)
                                                    client->query.attributes |=
                                                        NS_QUERYATTR_RECURSING;
                                                else
                                                    RECURSE_ERROR(result);
                                        }
                                        goto addauth;
                                }
                                /*
                                 * We were searching for SIG records in
                                 * a nonsecure zone.  Send a "no error,
                                 * no data" response.
                                 */
                                /*
                                 * Add SOA.
                                 */
                                result = query_addsoa(client, db, version,
                                                      ISC_FALSE);
                                if (result == ISC_R_SUCCESS)
                                        result = ISC_R_NOMORE;
                        } else {
                                /*
                                 * Something went wrong.
                                 */
                                result = DNS_R_SERVFAIL;
                        }
                }
                dns_rdatasetiter_destroy(&rdsiter);
                if (result != ISC_R_NOMORE) {
                        QUERY_ERROR(DNS_R_SERVFAIL);
                        goto cleanup;
                }
        } else {
                /*
                 * This is the "normal" case -- an ordinary question to which
                 * we know the answer.
                 */
#ifdef ALLOW_FILTER_AAAA_ON_V4
                /*
                 * Optionally hide AAAAs from IPv4 clients if there is an A.
                 * We add the AAAAs now, but might refuse to render them later
                 * after DNSSEC is figured out.
                 * This could be more efficient, but the whole idea is
                 * so fundamentally wrong, unavoidably inaccurate, and
                 * unneeded that it is best to keep it as short as possible.
                 */
                if (client->view->v4_aaaa != dns_v4_aaaa_ok &&
                    client->peeraddr_valid &&
                    client->peeraddr.type.sa.sa_family == AF_INET &&
                    (!WANTDNSSEC(client) ||
                     sigrdataset == NULL ||
                     !dns_rdataset_isassociated(sigrdataset) ||
                     client->view->v4_aaaa == dns_v4_aaaa_break_dnssec)) {
                        if (qtype == dns_rdatatype_aaaa) {
                                trdataset = query_newrdataset(client);
                                result = dns_db_findrdataset(db, node, version,
                                                        dns_rdatatype_a, 0,
                                                        client->now,
                                                        trdataset, NULL);
                                if (dns_rdataset_isassociated(trdataset))
                                        dns_rdataset_disassociate(trdataset);
                                query_putrdataset(client, &trdataset);

                                /*
                                 * We have an AAAA but the A is not in our cache.
                                 * Assume any result other than DNS_R_DELEGATION
                                 * or ISC_R_NOTFOUND means there is no A and
                                 * so AAAAs are ok.
                                 * Assume there is no A if we can't recurse
                                 * for this client, although that could be
                                 * the wrong answer. What else can we do?
                                 * Besides, that we have the AAAA and are using
                                 * this mechanism suggests that we care more
                                 * about As than AAAAs and would have cached
                                 * the A if it existed.
                                 */
                                if (result == ISC_R_SUCCESS) {
                                        client->attributes |=
                                                    NS_CLIENTATTR_FILTER_AAAA;

                                } else if (authoritative ||
                                           !RECURSIONOK(client) ||
                                           (result != DNS_R_DELEGATION &&
                                            result != ISC_R_NOTFOUND)) {
                                        client->attributes &=
                                                    ~NS_CLIENTATTR_FILTER_AAAA;
                                } else {
                                        /*
                                         * This is an ugly kludge to recurse
                                         * for the A and discard the result.
                                         *
                                         * Continue to add the AAAA now.
                                         * We'll make a note to not render it
                                         * if the recursion for the A succeeds.
                                         */
                                        result = query_recurse(client,
                                                        dns_rdatatype_a,
                                                        NULL, NULL, resuming);
                                        if (result == ISC_R_SUCCESS) {
                                            client->attributes |=
                                                    NS_CLIENTATTR_FILTER_AAAA_RC;
                                            client->query.attributes |=
                                                        NS_QUERYATTR_RECURSING;
                                        }
                                }

                        } else if (qtype == dns_rdatatype_a &&
                                   (client->attributes &
                                            NS_CLIENTATTR_FILTER_AAAA_RC) != 0) {
                                client->attributes &=
                                            ~NS_CLIENTATTR_FILTER_AAAA_RC;
                                client->attributes |=
                                            NS_CLIENTATTR_FILTER_AAAA;
                                dns_rdataset_disassociate(rdataset);
                                if (sigrdataset != NULL &&
                                    dns_rdataset_isassociated(sigrdataset))
                                        dns_rdataset_disassociate(sigrdataset);
                                goto cleanup;
                        }
                }
#endif
                if (sigrdataset != NULL)
                        sigrdatasetp = &sigrdataset;
                else
                        sigrdatasetp = NULL;
                if (NOQNAME(rdataset) && WANTDNSSEC(client))
                        noqname = rdataset;
                else
                        noqname = NULL;
                /*
                 * BIND 8 priming queries need the additional section.
                 */
                if (is_zone && qtype == dns_rdatatype_ns &&
                    dns_name_equal(client->query.qname, dns_rootname))
                        client->query.attributes &= ~NS_QUERYATTR_NOADDITIONAL;

                query_addrrset(client, &fname, &rdataset, sigrdatasetp, dbuf,
                               DNS_SECTION_ANSWER);
                if (noqname != NULL)
                        query_addnoqnameproof(client, noqname);
                /*
                 * We shouldn't ever fail to add 'rdataset'
                 * because it's already in the answer.
                 */
                INSIST(rdataset == NULL);
        }

 addauth:
        CTRACE("query_find: addauth");
        /*
         * Add NS records to the authority section (if we haven't already
         * added them to the answer section).
         */
        if (!want_restart && !NOAUTHORITY(client)) {
                if (is_zone) {
                        if (!((qtype == dns_rdatatype_ns ||
                               qtype == dns_rdatatype_any) &&
                              dns_name_equal(client->query.qname,
                                             dns_db_origin(db))))
                                (void)query_addns(client, db, version);
                } else if (qtype != dns_rdatatype_ns) {
                        if (fname != NULL)
                                query_releasename(client, &fname);
                        query_addbestns(client);
                }
        }

        /*
         * Add NSEC records to the authority section if they're needed for
         * DNSSEC wildcard proofs.
         */
        if (need_wildcardproof && dns_db_issecure(db))
                query_addwildcardproof(client, db, version,
                                       dns_fixedname_name(&wildcardname),
                                       ISC_TRUE);
 cleanup:
        CTRACE("query_find: cleanup");
        /*
         * General cleanup.
         */
        if (rdataset != NULL)
                query_putrdataset(client, &rdataset);
        if (sigrdataset != NULL)
                query_putrdataset(client, &sigrdataset);
        if (fname != NULL)
                query_releasename(client, &fname);
        if (node != NULL)
                dns_db_detachnode(db, &node);
        if (db != NULL)
                dns_db_detach(&db);
        if (zone != NULL)
                dns_zone_detach(&zone);
        if (zdb != NULL) {
                query_putrdataset(client, &zrdataset);
                if (zsigrdataset != NULL)
                        query_putrdataset(client, &zsigrdataset);
                if (zfname != NULL)
                        query_releasename(client, &zfname);
                dns_db_detach(&zdb);
        }
        if (event != NULL)
                isc_event_free(ISC_EVENT_PTR(&event));

        /*
         * AA bit.
         */
        if (client->query.restarts == 0 && !authoritative) {
                /*
                 * We're not authoritative, so we must ensure the AA bit
                 * isn't set.
                 */
                client->message->flags &= ~DNS_MESSAGEFLAG_AA;
        }

        /*
         * Restart the query?
         */
        if (want_restart && client->query.restarts < MAX_RESTARTS) {
                client->query.restarts++;
                goto restart;
        }

        if (eresult != ISC_R_SUCCESS &&
            (!PARTIALANSWER(client) || WANTRECURSION(client))) {
                if (eresult == DNS_R_DUPLICATE || eresult == DNS_R_DROP) {
                        /*
                         * This was a duplicate query that we are
                         * recursing on.  Don't send a response now.
                         * The original query will still cause a response.
                         */
                        query_next(client, eresult);
                } else {
                        /*
                         * If we don't have any answer to give the client,
                         * or if the client requested recursion and thus wanted
                         * the complete answer, send an error response.
                         */
                        INSIST(line >= 0);
                        query_error(client, eresult, line);
                }
                ns_client_detach(&client);
        } else if (!RECURSING(client)) {
                /*
                 * We are done.  Set up sortlist data for the message
                 * rendering code, make a final tweak to the AA bit if the
                 * auth-nxdomain config option says so, then render and
                 * send the response.
                 */
                setup_query_sortlist(client);

                /*
                 * If this is a referral and the answer to the question
                 * is in the glue sort it to the start of the additional
                 * section.
                 */
                if (ISC_LIST_EMPTY(client->message->sections[DNS_SECTION_ANSWER]) &&
                    client->message->rcode == dns_rcode_noerror &&
                    (qtype == dns_rdatatype_a || qtype == dns_rdatatype_aaaa))
                        answer_in_glue(client, qtype);

                if (client->message->rcode == dns_rcode_nxdomain &&
                    client->view->auth_nxdomain == ISC_TRUE)
                        client->message->flags |= DNS_MESSAGEFLAG_AA;

                /*
                 * If the response is somehow unexpected for the client and this
                 * is a result of recursion, return an error to the caller
                 * to indicate it may need to be logged.
                 */
                if (resuming &&
                    (ISC_LIST_EMPTY(client->message->sections[DNS_SECTION_ANSWER]) ||
                     client->message->rcode != dns_rcode_noerror))
                        eresult = ISC_R_FAILURE;

                query_send(client);
                ns_client_detach(&client);
        }
        CTRACE("query_find: done");

        return (eresult);
}

static inline void
log_query(ns_client_t *client, unsigned int flags, unsigned int extflags) {
        char namebuf[DNS_NAME_FORMATSIZE];
        char typename[DNS_RDATATYPE_FORMATSIZE];
        char classname[DNS_RDATACLASS_FORMATSIZE];
        char onbuf[ISC_NETADDR_FORMATSIZE];
        dns_rdataset_t *rdataset;
        int level = ISC_LOG_INFO;

        if (! isc_log_wouldlog(ns_g_lctx, level))
                return;

        rdataset = ISC_LIST_HEAD(client->query.qname->list);
        INSIST(rdataset != NULL);
        dns_name_format(client->query.qname, namebuf, sizeof(namebuf));
        dns_rdataclass_format(rdataset->rdclass, classname, sizeof(classname));
        dns_rdatatype_format(rdataset->type, typename, sizeof(typename));
        isc_netaddr_format(&client->destaddr, onbuf, sizeof(onbuf));

        ns_client_log(client, NS_LOGCATEGORY_QUERIES, NS_LOGMODULE_QUERY,
                      level, "query: %s %s %s %s%s%s%s%s%s (%s)", namebuf,
                      classname, typename, WANTRECURSION(client) ? "+" : "-",
                      (client->signer != NULL) ? "S": "",
                      (client->opt != NULL) ? "E" : "",
                      ((client->attributes & NS_CLIENTATTR_TCP) != 0) ?
                                 "T" : "",
                      ((extflags & DNS_MESSAGEEXTFLAG_DO) != 0) ? "D" : "",
                      ((flags & DNS_MESSAGEFLAG_CD) != 0) ? "C" : "",
                      onbuf);
}

static inline void
log_queryerror(ns_client_t *client, isc_result_t result, int line, int level) {
        char namebuf[DNS_NAME_FORMATSIZE];
        char typename[DNS_RDATATYPE_FORMATSIZE];
        char classname[DNS_RDATACLASS_FORMATSIZE];
        const char *namep, *typep, *classp, *sep1, *sep2;
        dns_rdataset_t *rdataset;

        if (!isc_log_wouldlog(ns_g_lctx, level))
                return;

        namep = typep = classp = sep1 = sep2 = "";

        /*
         * Query errors can happen for various reasons.  In some cases we cannot
         * even assume the query contains a valid question section, so we should
         * expect exceptional cases.
         */
        if (client->query.origqname != NULL) {
                dns_name_format(client->query.origqname, namebuf,
                                sizeof(namebuf));
                namep = namebuf;
                sep1 = " for ";

                rdataset = ISC_LIST_HEAD(client->query.origqname->list);
                if (rdataset != NULL) {
                        dns_rdataclass_format(rdataset->rdclass, classname,
                                              sizeof(classname));
                        classp = classname;
                        dns_rdatatype_format(rdataset->type, typename,
                                             sizeof(typename));
                        typep = typename;
                        sep2 = "/";
                }
        }

        ns_client_log(client, NS_LOGCATEGORY_QUERY_EERRORS, NS_LOGMODULE_QUERY,
                      level, "query failed (%s)%s%s%s%s%s%s at %s:%d",
                      isc_result_totext(result), sep1, namep, sep2,
                      classp, sep2, typep, __FILE__, line);
}

void
ns_query_start(ns_client_t *client) {
        isc_result_t result;
        dns_message_t *message = client->message;
        dns_rdataset_t *rdataset;
        ns_client_t *qclient;
        dns_rdatatype_t qtype;
        unsigned int saved_extflags = client->extflags;
        unsigned int saved_flags = client->message->flags;
        isc_boolean_t want_ad;

        CTRACE("ns_query_start");

        /*
         * Test only.
         */
        if (ns_g_clienttest && (client->attributes & NS_CLIENTATTR_TCP) == 0)
                RUNTIME_CHECK(ns_client_replace(client) == ISC_R_SUCCESS);

        /*
         * Ensure that appropriate cleanups occur.
         */
        client->next = query_next_callback;

        /*
         * Behave as if we don't support DNSSEC if not enabled.
         */
        if (!client->view->enablednssec) {
                message->flags &= ~DNS_MESSAGEFLAG_CD;
                client->extflags &= ~DNS_MESSAGEEXTFLAG_DO;
                if (client->opt != NULL)
                        client->opt->ttl &= ~DNS_MESSAGEEXTFLAG_DO;
        }

        if ((message->flags & DNS_MESSAGEFLAG_RD) != 0)
                client->query.attributes |= NS_QUERYATTR_WANTRECURSION;

        if ((client->extflags & DNS_MESSAGEEXTFLAG_DO) != 0)
                client->attributes |= NS_CLIENTATTR_WANTDNSSEC;

        if (client->view->minimalresponses)
                client->query.attributes |= (NS_QUERYATTR_NOAUTHORITY |
                                             NS_QUERYATTR_NOADDITIONAL);

        if ((client->view->cachedb == NULL)
            || (!client->view->additionalfromcache)) {
                /*
                 * We don't have a cache.  Turn off cache support and
                 * recursion.
                 */
                client->query.attributes &=
                        ~(NS_QUERYATTR_RECURSIONOK|NS_QUERYATTR_CACHEOK);
        } else if ((client->attributes & NS_CLIENTATTR_RA) == 0 ||
                   (message->flags & DNS_MESSAGEFLAG_RD) == 0) {
                /*
                 * If the client isn't allowed to recurse (due to
                 * "recursion no", the allow-recursion ACL, or the
                 * lack of a resolver in this view), or if it
                 * doesn't want recursion, turn recursion off.
                 */
                client->query.attributes &= ~NS_QUERYATTR_RECURSIONOK;
        }

        /*
         * Get the question name.
         */
        result = dns_message_firstname(message, DNS_SECTION_QUESTION);
        if (result != ISC_R_SUCCESS) {
                query_error(client, result, __LINE__);
                return;
        }
        dns_message_currentname(message, DNS_SECTION_QUESTION,
                                &client->query.qname);
        client->query.origqname = client->query.qname;
        result = dns_message_nextname(message, DNS_SECTION_QUESTION);
        if (result != ISC_R_NOMORE) {
                if (result == ISC_R_SUCCESS) {
                        /*
                         * There's more than one QNAME in the question
                         * section.
                         */
                        query_error(client, DNS_R_FORMERR, __LINE__);
                } else
                        query_error(client, result, __LINE__);
                return;
        }

        if (ns_g_server->log_queries)
                log_query(client, saved_flags, saved_extflags);

        /*
         * Check for multiple question queries, since edns1 is dead.
         */
        if (message->counts[DNS_SECTION_QUESTION] > 1) {
                query_error(client, DNS_R_FORMERR, __LINE__);
                return;
        }

        /*
         * Check for meta-queries like IXFR and AXFR.
         */
        rdataset = ISC_LIST_HEAD(client->query.qname->list);
        INSIST(rdataset != NULL);
        qtype = rdataset->type;
        dns_rdatatypestats_increment(ns_g_server->rcvquerystats, qtype);
        if (dns_rdatatype_ismeta(qtype)) {
                switch (qtype) {
                case dns_rdatatype_any:
                        break; /* Let query_find handle it. */
                case dns_rdatatype_ixfr:
                case dns_rdatatype_axfr:
                        ns_xfr_start(client, rdataset->type);
                        return;
                case dns_rdatatype_maila:
                case dns_rdatatype_mailb:
                        query_error(client, DNS_R_NOTIMP, __LINE__);
                        return;
                case dns_rdatatype_tkey:
                        result = dns_tkey_processquery(client->message,
                                                ns_g_server->tkeyctx,
                                                client->view->dynamickeys);
                        if (result == ISC_R_SUCCESS)
                                query_send(client);
                        else
                                query_error(client, result, __LINE__);
                        return;
                default: /* TSIG, etc. */
                        query_error(client, DNS_R_FORMERR, __LINE__);
                        return;
                }
        }

        /*
         * Turn on minimal response for DNSKEY and DS queries.
         */
        if (qtype == dns_rdatatype_dnskey || qtype == dns_rdatatype_ds)
                client->query.attributes |= (NS_QUERYATTR_NOAUTHORITY |
                                             NS_QUERYATTR_NOADDITIONAL);

        /*
         * Turn on minimal responses for EDNS/UDP bufsize 512 queries.
         */
        if (client->opt != NULL && client->udpsize <= 512U &&
            (client->attributes & NS_CLIENTATTR_TCP) == 0)
                client->query.attributes |= (NS_QUERYATTR_NOAUTHORITY |
                                             NS_QUERYATTR_NOADDITIONAL);

        /*
         * If the client has requested that DNSSEC checking be disabled,
         * allow lookups to return pending data and instruct the resolver
         * to return data before validation has completed.
         *
         * We don't need to set DNS_DBFIND_PENDINGOK when validation is
         * disabled as there will be no pending data.
         */
        if (message->flags & DNS_MESSAGEFLAG_CD ||
            qtype == dns_rdatatype_rrsig)
        {
                client->query.dboptions |= DNS_DBFIND_PENDINGOK;
                client->query.fetchoptions |= DNS_FETCHOPT_NOVALIDATE;
        } else if (!client->view->enablevalidation)
                client->query.fetchoptions |= DNS_FETCHOPT_NOVALIDATE;

        /*
         * Allow glue NS records to be added to the authority section
         * if the answer is secure.
         */
        if (message->flags & DNS_MESSAGEFLAG_CD)
                client->query.attributes &= ~NS_QUERYATTR_SECURE;

        /*
         * Set 'want_ad' if the client has set AD in the query.
         * This allows AD to be returned on queries without DO set.
         */
        if ((message->flags & DNS_MESSAGEFLAG_AD) != 0)
                want_ad = ISC_TRUE;
        else
                want_ad = ISC_FALSE;

        /*
         * This is an ordinary query.
         */
        result = dns_message_reply(message, ISC_TRUE);
        if (result != ISC_R_SUCCESS) {
                query_next(client, result);
                return;
        }

        /*
         * Assume authoritative response until it is known to be
         * otherwise.
         */
        message->flags |= DNS_MESSAGEFLAG_AA;

        /*
         * Set AD.  We must clear it if we add non-validated data to a
         * response.
         */
        if (WANTDNSSEC(client) || want_ad)
                message->flags |= DNS_MESSAGEFLAG_AD;

        qclient = NULL;
        ns_client_attach(client, &qclient);
        (void)query_find(qclient, NULL, qtype);
}