lib/dns/view.c

	view.c revision ec5347e2c775f027573ce5648b910361aa926c01
/*
 * Copyright (C) 2004-2007  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: view.c,v 1.143 2007/06/18 23:47:42 tbox Exp $ */

/*! \file */

#include <config.h>

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

#include <dns/acache.h>
#include <dns/acl.h>
#include <dns/adb.h>
#include <dns/cache.h>
#include <dns/db.h>
#include <dns/dlz.h>
#include <dns/events.h>
#include <dns/forward.h>
#include <dns/keytable.h>
#include <dns/master.h>
#include <dns/masterdump.h>
#include <dns/order.h>
#include <dns/peer.h>
#include <dns/rdataset.h>
#include <dns/request.h>
#include <dns/resolver.h>
#include <dns/result.h>
#include <dns/tsig.h>
#include <dns/zone.h>
#include <dns/zt.h>

#define RESSHUTDOWN(v)  (((v)->attributes & DNS_VIEWATTR_RESSHUTDOWN) != 0)
#define ADBSHUTDOWN(v)  (((v)->attributes & DNS_VIEWATTR_ADBSHUTDOWN) != 0)
#define REQSHUTDOWN(v)  (((v)->attributes & DNS_VIEWATTR_REQSHUTDOWN) != 0)

#define DNS_VIEW_DELONLYHASH 111

static void resolver_shutdown(isc_task_t *task, isc_event_t *event);
static void adb_shutdown(isc_task_t *task, isc_event_t *event);
static void req_shutdown(isc_task_t *task, isc_event_t *event);

isc_result_t
dns_view_create(isc_mem_t *mctx, dns_rdataclass_t rdclass,
        const char *name, dns_view_t **viewp)
{
    dns_view_t *view;
    isc_result_t result;

    /*
     * Create a view.
     */

    REQUIRE(name != NULL);
    REQUIRE(viewp != NULL && *viewp == NULL);

    view = isc_mem_get(mctx, sizeof(*view));
    if (view == NULL)
        return (ISC_R_NOMEMORY);
    view->name = isc_mem_strdup(mctx, name);
    if (view->name == NULL) {
        result = ISC_R_NOMEMORY;
        goto cleanup_view;
    }
    result = isc_mutex_init(&view->lock);
    if (result != ISC_R_SUCCESS)
        goto cleanup_name;

    view->zonetable = NULL;
    result = dns_zt_create(mctx, rdclass, &view->zonetable);
    if (result != ISC_R_SUCCESS) {
        UNEXPECTED_ERROR(__FILE__, __LINE__,
                 "dns_zt_create() failed: %s",
                 isc_result_totext(result));
        result = ISC_R_UNEXPECTED;
        goto cleanup_mutex;
    }
    view->secroots = NULL;
    result = dns_keytable_create(mctx, &view->secroots);
    if (result != ISC_R_SUCCESS) {
        UNEXPECTED_ERROR(__FILE__, __LINE__,
                 "dns_keytable_create() failed: %s",
                 isc_result_totext(result));
        result = ISC_R_UNEXPECTED;
        goto cleanup_zt;
    }
    view->trustedkeys = NULL;
    result = dns_keytable_create(mctx, &view->trustedkeys);
    if (result != ISC_R_SUCCESS) {
        UNEXPECTED_ERROR(__FILE__, __LINE__,
                 "dns_keytable_create() failed: %s",
                 isc_result_totext(result));
        result = ISC_R_UNEXPECTED;
        goto cleanup_secroots;
    }
    view->fwdtable = NULL;
    result = dns_fwdtable_create(mctx, &view->fwdtable);
    if (result != ISC_R_SUCCESS) {
        UNEXPECTED_ERROR(__FILE__, __LINE__,
                 "dns_fwdtable_create() failed: %s",
                 isc_result_totext(result));
        result = ISC_R_UNEXPECTED;
        goto cleanup_trustedkeys;
    }

    view->acache = NULL;
    view->cache = NULL;
    view->cachedb = NULL;
    view->dlzdatabase = NULL;
    view->hints = NULL;
    view->resolver = NULL;
    view->adb = NULL;
    view->requestmgr = NULL;
    view->mctx = mctx;
    view->rdclass = rdclass;
    view->frozen = ISC_FALSE;
    view->task = NULL;
    result = isc_refcount_init(&view->references, 1);
    if (result != ISC_R_SUCCESS)
        goto cleanup_fwdtable;
    view->weakrefs = 0;
    view->attributes = (DNS_VIEWATTR_RESSHUTDOWN|DNS_VIEWATTR_ADBSHUTDOWN|
                DNS_VIEWATTR_REQSHUTDOWN);
    view->statickeys = NULL;
    view->dynamickeys = NULL;
    view->matchclients = NULL;
    view->matchdestinations = NULL;
    view->matchrecursiveonly = ISC_FALSE;
    result = dns_tsigkeyring_create(view->mctx, &view->dynamickeys);
    if (result != ISC_R_SUCCESS)
        goto cleanup_references;
    view->peers = NULL;
    view->order = NULL;
    view->delonly = NULL;
    view->rootdelonly = ISC_FALSE;
    view->rootexclude = NULL;

    /*
     * Initialize configuration data with default values.
     */
    view->recursion = ISC_TRUE;
    view->auth_nxdomain = ISC_FALSE; /* Was true in BIND 8 */
    view->additionalfromcache = ISC_TRUE;
    view->additionalfromauth = ISC_TRUE;
    view->enablednssec = ISC_TRUE;
    view->enablevalidation = ISC_TRUE;
    view->acceptexpired = ISC_FALSE;
    view->minimalresponses = ISC_FALSE;
    view->transfer_format = dns_one_answer;
    view->queryacl = NULL;
    view->queryonacl = NULL;
    view->recursionacl = NULL;
    view->recursiononacl = NULL;
    view->sortlist = NULL;
    view->requestixfr = ISC_TRUE;
    view->provideixfr = ISC_TRUE;
    view->maxcachettl = 7 * 24 * 3600;
    view->maxncachettl = 3 * 3600;
    view->dstport = 53;
    view->preferred_glue = 0;
    view->flush = ISC_FALSE;
    view->dlv = NULL;
    view->maxudp = 0;
    dns_fixedname_init(&view->dlv_fixed);

    result = dns_order_create(view->mctx, &view->order);
    if (result != ISC_R_SUCCESS)
        goto cleanup_dynkeys;

    result = dns_peerlist_new(view->mctx, &view->peers);
    if (result != ISC_R_SUCCESS)
        goto cleanup_order;

    result = dns_aclenv_init(view->mctx, &view->aclenv);
    if (result != ISC_R_SUCCESS)
        goto cleanup_peerlist;

    ISC_LINK_INIT(view, link);
    ISC_EVENT_INIT(&view->resevent, sizeof(view->resevent), 0, NULL,
               DNS_EVENT_VIEWRESSHUTDOWN, resolver_shutdown,
               view, NULL, NULL, NULL);
    ISC_EVENT_INIT(&view->adbevent, sizeof(view->adbevent), 0, NULL,
               DNS_EVENT_VIEWADBSHUTDOWN, adb_shutdown,
               view, NULL, NULL, NULL);
    ISC_EVENT_INIT(&view->reqevent, sizeof(view->reqevent), 0, NULL,
               DNS_EVENT_VIEWREQSHUTDOWN, req_shutdown,
               view, NULL, NULL, NULL);
    view->magic = DNS_VIEW_MAGIC;

    *viewp = view;

    return (ISC_R_SUCCESS);

 cleanup_peerlist:
    dns_peerlist_detach(&view->peers);

 cleanup_order:
    dns_order_detach(&view->order);

 cleanup_dynkeys:
    dns_tsigkeyring_destroy(&view->dynamickeys);

 cleanup_references:
    isc_refcount_destroy(&view->references);

 cleanup_fwdtable:
    dns_fwdtable_destroy(&view->fwdtable);

 cleanup_trustedkeys:
    dns_keytable_detach(&view->trustedkeys);

 cleanup_secroots:
    dns_keytable_detach(&view->secroots);

 cleanup_zt:
    dns_zt_detach(&view->zonetable);

 cleanup_mutex:
    DESTROYLOCK(&view->lock);

 cleanup_name:
    isc_mem_free(mctx, view->name);

 cleanup_view:
    isc_mem_put(mctx, view, sizeof(*view));

    return (result);
}

static inline void
destroy(dns_view_t *view) {
    REQUIRE(!ISC_LINK_LINKED(view, link));
    REQUIRE(isc_refcount_current(&view->references) == 0);
    REQUIRE(view->weakrefs == 0);
    REQUIRE(RESSHUTDOWN(view));
    REQUIRE(ADBSHUTDOWN(view));
    REQUIRE(REQSHUTDOWN(view));

    if (view->order != NULL)
        dns_order_detach(&view->order);
    if (view->peers != NULL)
        dns_peerlist_detach(&view->peers);
    if (view->dynamickeys != NULL)
        dns_tsigkeyring_destroy(&view->dynamickeys);
    if (view->statickeys != NULL)
        dns_tsigkeyring_destroy(&view->statickeys);
    if (view->adb != NULL)
        dns_adb_detach(&view->adb);
    if (view->resolver != NULL)
        dns_resolver_detach(&view->resolver);
    if (view->acache != NULL) {
        if (view->cachedb != NULL)
            dns_acache_putdb(view->acache, view->cachedb);
        dns_acache_detach(&view->acache);
    }
    if (view->requestmgr != NULL)
        dns_requestmgr_detach(&view->requestmgr);
    if (view->task != NULL)
        isc_task_detach(&view->task);
    if (view->hints != NULL)
        dns_db_detach(&view->hints);
    if (view->dlzdatabase != NULL)
        dns_dlzdestroy(&view->dlzdatabase);
    if (view->cachedb != NULL)
        dns_db_detach(&view->cachedb);
    if (view->cache != NULL)
        dns_cache_detach(&view->cache);
    if (view->matchclients != NULL)
        dns_acl_detach(&view->matchclients);
    if (view->matchdestinations != NULL)
        dns_acl_detach(&view->matchdestinations);
    if (view->queryacl != NULL)
        dns_acl_detach(&view->queryacl);
    if (view->queryonacl != NULL)
        dns_acl_detach(&view->queryonacl);
    if (view->recursionacl != NULL)
        dns_acl_detach(&view->recursionacl);
    if (view->recursiononacl != NULL)
        dns_acl_detach(&view->recursiononacl);
    if (view->sortlist != NULL)
        dns_acl_detach(&view->sortlist);
    if (view->delonly != NULL) {
        dns_name_t *name;
        int i;

        for (i = 0; i < DNS_VIEW_DELONLYHASH; i++) {
            name = ISC_LIST_HEAD(view->delonly[i]);
            while (name != NULL) {
                ISC_LIST_UNLINK(view->delonly[i], name, link);
                dns_name_free(name, view->mctx);
                isc_mem_put(view->mctx, name, sizeof(*name));
                name = ISC_LIST_HEAD(view->delonly[i]);
            }
        }
        isc_mem_put(view->mctx, view->delonly, sizeof(dns_namelist_t) *
                DNS_VIEW_DELONLYHASH);
        view->delonly = NULL;
    }
    if (view->rootexclude != NULL) {
        dns_name_t *name;
        int i;

        for (i = 0; i < DNS_VIEW_DELONLYHASH; i++) {
            name = ISC_LIST_HEAD(view->rootexclude[i]);
            while (name != NULL) {
                ISC_LIST_UNLINK(view->rootexclude[i],
                        name, link);
                dns_name_free(name, view->mctx);
                isc_mem_put(view->mctx, name, sizeof(*name));
                name = ISC_LIST_HEAD(view->rootexclude[i]);
            }
        }
        isc_mem_put(view->mctx, view->rootexclude,
                sizeof(dns_namelist_t) * DNS_VIEW_DELONLYHASH);
        view->rootexclude = NULL;
    }
    dns_keytable_detach(&view->trustedkeys);
    dns_keytable_detach(&view->secroots);
    dns_fwdtable_destroy(&view->fwdtable);
    dns_aclenv_destroy(&view->aclenv);
    DESTROYLOCK(&view->lock);
    isc_refcount_destroy(&view->references);
    isc_mem_free(view->mctx, view->name);
    isc_mem_put(view->mctx, view, sizeof(*view));
}

/*
 * Return true iff 'view' may be freed.
 * The caller must be holding the view lock.
 */
static isc_boolean_t
all_done(dns_view_t *view) {

    if (isc_refcount_current(&view->references) == 0 &&
        view->weakrefs == 0 &&
        RESSHUTDOWN(view) && ADBSHUTDOWN(view) && REQSHUTDOWN(view))
        return (ISC_TRUE);

    return (ISC_FALSE);
}

void
dns_view_attach(dns_view_t *source, dns_view_t **targetp) {

    REQUIRE(DNS_VIEW_VALID(source));
    REQUIRE(targetp != NULL && *targetp == NULL);

    isc_refcount_increment(&source->references, NULL);

    *targetp = source;
}

static void
view_flushanddetach(dns_view_t **viewp, isc_boolean_t flush) {
    dns_view_t *view;
    unsigned int refs;
    isc_boolean_t done = ISC_FALSE;

    REQUIRE(viewp != NULL);
    view = *viewp;
    REQUIRE(DNS_VIEW_VALID(view));

    if (flush)
        view->flush = ISC_TRUE;
    isc_refcount_decrement(&view->references, &refs);
    if (refs == 0) {
        LOCK(&view->lock);
        if (!RESSHUTDOWN(view))
            dns_resolver_shutdown(view->resolver);
        if (!ADBSHUTDOWN(view))
            dns_adb_shutdown(view->adb);
        if (!REQSHUTDOWN(view))
            dns_requestmgr_shutdown(view->requestmgr);
        if (view->acache != NULL)
            dns_acache_shutdown(view->acache);
        if (view->flush)
            dns_zt_flushanddetach(&view->zonetable);
        else
            dns_zt_detach(&view->zonetable);
        done = all_done(view);
        UNLOCK(&view->lock);
    }

    *viewp = NULL;

    if (done)
        destroy(view);
}

void
dns_view_flushanddetach(dns_view_t **viewp) {
    view_flushanddetach(viewp, ISC_TRUE);
}

void
dns_view_detach(dns_view_t **viewp) {
    view_flushanddetach(viewp, ISC_FALSE);
}

static isc_result_t
dialup(dns_zone_t *zone, void *dummy) {
    UNUSED(dummy);
    dns_zone_dialup(zone);
    return (ISC_R_SUCCESS);
}

void
dns_view_dialup(dns_view_t *view) {
    REQUIRE(DNS_VIEW_VALID(view));
    (void)dns_zt_apply(view->zonetable, ISC_FALSE, dialup, NULL);
}

void
dns_view_weakattach(dns_view_t *source, dns_view_t **targetp) {

    REQUIRE(DNS_VIEW_VALID(source));
    REQUIRE(targetp != NULL && *targetp == NULL);

    LOCK(&source->lock);
    source->weakrefs++;
    UNLOCK(&source->lock);

    *targetp = source;
}

void
dns_view_weakdetach(dns_view_t **viewp) {
    dns_view_t *view;
    isc_boolean_t done = ISC_FALSE;

    REQUIRE(viewp != NULL);
    view = *viewp;
    REQUIRE(DNS_VIEW_VALID(view));

    LOCK(&view->lock);

    INSIST(view->weakrefs > 0);
    view->weakrefs--;
    done = all_done(view);

    UNLOCK(&view->lock);

    *viewp = NULL;

    if (done)
        destroy(view);
}

static void
resolver_shutdown(isc_task_t *task, isc_event_t *event) {
    dns_view_t *view = event->ev_arg;
    isc_boolean_t done;

    REQUIRE(event->ev_type == DNS_EVENT_VIEWRESSHUTDOWN);
    REQUIRE(DNS_VIEW_VALID(view));
    REQUIRE(view->task == task);

    UNUSED(task);

    LOCK(&view->lock);

    view->attributes |= DNS_VIEWATTR_RESSHUTDOWN;
    done = all_done(view);

    UNLOCK(&view->lock);

    isc_event_free(&event);

    if (done)
        destroy(view);
}

static void
adb_shutdown(isc_task_t *task, isc_event_t *event) {
    dns_view_t *view = event->ev_arg;
    isc_boolean_t done;

    REQUIRE(event->ev_type == DNS_EVENT_VIEWADBSHUTDOWN);
    REQUIRE(DNS_VIEW_VALID(view));
    REQUIRE(view->task == task);

    UNUSED(task);

    LOCK(&view->lock);

    view->attributes |= DNS_VIEWATTR_ADBSHUTDOWN;
    done = all_done(view);

    UNLOCK(&view->lock);

    isc_event_free(&event);

    if (done)
        destroy(view);
}

static void
req_shutdown(isc_task_t *task, isc_event_t *event) {
    dns_view_t *view = event->ev_arg;
    isc_boolean_t done;

    REQUIRE(event->ev_type == DNS_EVENT_VIEWREQSHUTDOWN);
    REQUIRE(DNS_VIEW_VALID(view));
    REQUIRE(view->task == task);

    UNUSED(task);

    LOCK(&view->lock);

    view->attributes |= DNS_VIEWATTR_REQSHUTDOWN;
    done = all_done(view);

    UNLOCK(&view->lock);

    isc_event_free(&event);

    if (done)
        destroy(view);
}

isc_result_t
dns_view_createresolver(dns_view_t *view,
            isc_taskmgr_t *taskmgr, unsigned int ntasks,
            isc_socketmgr_t *socketmgr,
            isc_timermgr_t *timermgr,
            unsigned int options,
            dns_dispatchmgr_t *dispatchmgr,
            dns_dispatch_t *dispatchv4,
            dns_dispatch_t *dispatchv6)
{
    isc_result_t result;
    isc_event_t *event;
    isc_mem_t *mctx = NULL;

    REQUIRE(DNS_VIEW_VALID(view));
    REQUIRE(!view->frozen);
    REQUIRE(view->resolver == NULL);

    result = isc_task_create(taskmgr, 0, &view->task);
    if (result != ISC_R_SUCCESS)
        return (result);
    isc_task_setname(view->task, "view", view);

    result = dns_resolver_create(view, taskmgr, ntasks, socketmgr,
                     timermgr, options, dispatchmgr,
                     dispatchv4, dispatchv6,
                     &view->resolver);
    if (result != ISC_R_SUCCESS) {
        isc_task_detach(&view->task);
        return (result);
    }
    event = &view->resevent;
    dns_resolver_whenshutdown(view->resolver, view->task, &event);
    view->attributes &= ~DNS_VIEWATTR_RESSHUTDOWN;

    result = isc_mem_create(0, 0, &mctx);
    if (result != ISC_R_SUCCESS) {
        dns_resolver_shutdown(view->resolver);
        return (result);
    }

    result = dns_adb_create(mctx, view, timermgr, taskmgr, &view->adb);
    isc_mem_detach(&mctx);
    if (result != ISC_R_SUCCESS) {
        dns_resolver_shutdown(view->resolver);
        return (result);
    }
    event = &view->adbevent;
    dns_adb_whenshutdown(view->adb, view->task, &event);
    view->attributes &= ~DNS_VIEWATTR_ADBSHUTDOWN;

    result = dns_requestmgr_create(view->mctx, timermgr, socketmgr,
                      dns_resolver_taskmgr(view->resolver),
                      dns_resolver_dispatchmgr(view->resolver),
                      dns_resolver_dispatchv4(view->resolver),
                      dns_resolver_dispatchv6(view->resolver),
                      &view->requestmgr);
    if (result != ISC_R_SUCCESS) {
        dns_adb_shutdown(view->adb);
        dns_resolver_shutdown(view->resolver);
        return (result);
    }
    event = &view->reqevent;
    dns_requestmgr_whenshutdown(view->requestmgr, view->task, &event);
    view->attributes &= ~DNS_VIEWATTR_REQSHUTDOWN;

    return (ISC_R_SUCCESS);
}

void
dns_view_setcache(dns_view_t *view, dns_cache_t *cache) {
    REQUIRE(DNS_VIEW_VALID(view));
    REQUIRE(!view->frozen);

    if (view->cache != NULL) {
        if (view->acache != NULL)
            dns_acache_putdb(view->acache, view->cachedb);
        dns_db_detach(&view->cachedb);
        dns_cache_detach(&view->cache);
    }
    dns_cache_attach(cache, &view->cache);
    dns_cache_attachdb(cache, &view->cachedb);
    INSIST(DNS_DB_VALID(view->cachedb));

    if (view->acache != NULL)
        dns_acache_setdb(view->acache, view->cachedb);
}

void
dns_view_sethints(dns_view_t *view, dns_db_t *hints) {
    REQUIRE(DNS_VIEW_VALID(view));
    REQUIRE(!view->frozen);
    REQUIRE(view->hints == NULL);
    REQUIRE(dns_db_iszone(hints));

    dns_db_attach(hints, &view->hints);
}

void
dns_view_setkeyring(dns_view_t *view, dns_tsig_keyring_t *ring) {
    REQUIRE(DNS_VIEW_VALID(view));
    REQUIRE(ring != NULL);
    if (view->statickeys != NULL)
        dns_tsigkeyring_destroy(&view->statickeys);
    view->statickeys = ring;
}

void
dns_view_setdstport(dns_view_t *view, in_port_t dstport) {
    REQUIRE(DNS_VIEW_VALID(view));
    view->dstport = dstport;
}

isc_result_t
dns_view_addzone(dns_view_t *view, dns_zone_t *zone) {
    isc_result_t result;

    REQUIRE(DNS_VIEW_VALID(view));
    REQUIRE(!view->frozen);

    result = dns_zt_mount(view->zonetable, zone);

    return (result);
}

void
dns_view_freeze(dns_view_t *view) {
    REQUIRE(DNS_VIEW_VALID(view));
    REQUIRE(!view->frozen);

    if (view->resolver != NULL) {
        INSIST(view->cachedb != NULL);
        dns_resolver_freeze(view->resolver);
    }
    view->frozen = ISC_TRUE;
}

isc_result_t
dns_view_findzone(dns_view_t *view, dns_name_t *name, dns_zone_t **zonep) {
    isc_result_t result;

    REQUIRE(DNS_VIEW_VALID(view));

    result = dns_zt_find(view->zonetable, name, 0, NULL, zonep);
    if (result == DNS_R_PARTIALMATCH) {
        dns_zone_detach(zonep);
        result = ISC_R_NOTFOUND;
    }

    return (result);
}

isc_result_t
dns_view_find(dns_view_t *view, dns_name_t *name, dns_rdatatype_t type,
          isc_stdtime_t now, unsigned int options, isc_boolean_t use_hints,
          dns_db_t **dbp, dns_dbnode_t **nodep, dns_name_t *foundname,
          dns_rdataset_t *rdataset, dns_rdataset_t *sigrdataset)
{
    isc_result_t result;
    dns_db_t *db, *zdb;
    dns_dbnode_t *node, *znode;
    isc_boolean_t is_cache;
    dns_rdataset_t zrdataset, zsigrdataset;
    dns_zone_t *zone;

    /*
     * Find an rdataset whose owner name is 'name', and whose type is
     * 'type'.
     */

    REQUIRE(DNS_VIEW_VALID(view));
    REQUIRE(view->frozen);
    REQUIRE(type != dns_rdatatype_rrsig);
    REQUIRE(rdataset != NULL);  /* XXXBEW - remove this */
    REQUIRE(nodep == NULL || *nodep == NULL);

    /*
     * Initialize.
     */
    dns_rdataset_init(&zrdataset);
    dns_rdataset_init(&zsigrdataset);
    zdb = NULL;
    znode = NULL;

    /*
     * Find a database to answer the query.
     */
    zone = NULL;
    db = NULL;
    node = NULL;
    result = dns_zt_find(view->zonetable, name, 0, NULL, &zone);
    if (result == ISC_R_SUCCESS || result == DNS_R_PARTIALMATCH) {
        result = dns_zone_getdb(zone, &db);
        if (result != ISC_R_SUCCESS && view->cachedb != NULL)
            dns_db_attach(view->cachedb, &db);
        else if (result != ISC_R_SUCCESS)
            goto cleanup;
    } else if (result == ISC_R_NOTFOUND && view->cachedb != NULL)
        dns_db_attach(view->cachedb, &db);
    else
        goto cleanup;

    is_cache = dns_db_iscache(db);

 db_find:
    /*
     * Now look for an answer in the database.
     */
    result = dns_db_find(db, name, NULL, type, options,
                 now, &node, foundname, rdataset, sigrdataset);

    if (result == DNS_R_DELEGATION ||
        result == ISC_R_NOTFOUND) {
        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);
        if (!is_cache) {
            dns_db_detach(&db);
            if (view->cachedb != NULL) {
                /*
                 * Either the answer is in the cache, or we
                 * don't know it.
                 */
                is_cache = ISC_TRUE;
                dns_db_attach(view->cachedb, &db);
                goto db_find;
            }
        } else {
            /*
             * We don't have the data in the cache.  If we've got
             * glue from the zone, use it.
             */
            if (dns_rdataset_isassociated(&zrdataset)) {
                dns_rdataset_clone(&zrdataset, rdataset);
                if (sigrdataset != NULL &&
                    dns_rdataset_isassociated(&zsigrdataset))
                    dns_rdataset_clone(&zsigrdataset,
                               sigrdataset);
                result = DNS_R_GLUE;
                if (db != NULL)
                    dns_db_detach(&db);
                dns_db_attach(zdb, &db);
                dns_db_attachnode(db, znode, &node);
                goto cleanup;
            }
        }
        /*
         * We don't know the answer.
         */
        result = ISC_R_NOTFOUND;
    } else if (result == DNS_R_GLUE) {
        if (view->cachedb != NULL) {
            /*
             * We found an answer, but the cache may be better.
             * Remember what we've got and go look in the cache.
             */
            is_cache = ISC_TRUE;
            dns_rdataset_clone(rdataset, &zrdataset);
            dns_rdataset_disassociate(rdataset);
            if (sigrdataset != NULL &&
                dns_rdataset_isassociated(sigrdataset)) {
                dns_rdataset_clone(sigrdataset, &zsigrdataset);
                dns_rdataset_disassociate(sigrdataset);
            }
            dns_db_attach(db, &zdb);
            dns_db_attachnode(zdb, node, &znode);
            dns_db_detachnode(db, &node);
            dns_db_detach(&db);
            dns_db_attach(view->cachedb, &db);
            goto db_find;
        }
        /*
         * Otherwise, the glue is the best answer.
         */
        result = ISC_R_SUCCESS;
    }

    if (result == ISC_R_NOTFOUND && use_hints && view->hints != NULL) {
        if (dns_rdataset_isassociated(rdataset))
            dns_rdataset_disassociate(rdataset);
        if (sigrdataset != NULL &&
            dns_rdataset_isassociated(sigrdataset))
            dns_rdataset_disassociate(sigrdataset);
        if (db != NULL) {
            if (node != NULL)
                dns_db_detachnode(db, &node);
            dns_db_detach(&db);
        }
        result = dns_db_find(view->hints, name, NULL, type, options,
                     now, &node, foundname,
                     rdataset, sigrdataset);
        if (result == ISC_R_SUCCESS || result == DNS_R_GLUE) {
            /*
             * We just used a hint.  Let the resolver know it
             * should consider priming.
             */
            dns_resolver_prime(view->resolver);
            dns_db_attach(view->hints, &db);
            result = DNS_R_HINT;
        } else if (result == DNS_R_NXRRSET) {
            dns_db_attach(view->hints, &db);
            result = DNS_R_HINTNXRRSET;
        } else if (result == DNS_R_NXDOMAIN)
            result = ISC_R_NOTFOUND;

        /*
         * Cleanup if non-standard hints are used.
         */
        if (db == NULL && node != NULL)
            dns_db_detachnode(view->hints, &node);
    }

 cleanup:
    if (result == DNS_R_NXDOMAIN || result == DNS_R_NXRRSET) {
        /*
         * We don't care about any DNSSEC proof data in these cases.
         */
        if (dns_rdataset_isassociated(rdataset))
            dns_rdataset_disassociate(rdataset);
        if (sigrdataset != NULL &&
            dns_rdataset_isassociated(sigrdataset))
            dns_rdataset_disassociate(sigrdataset);
    }

    if (dns_rdataset_isassociated(&zrdataset)) {
        dns_rdataset_disassociate(&zrdataset);
        if (dns_rdataset_isassociated(&zsigrdataset))
            dns_rdataset_disassociate(&zsigrdataset);
    }

    if (zdb != NULL) {
        if (znode != NULL)
            dns_db_detachnode(zdb, &znode);
        dns_db_detach(&zdb);
    }

    if (db != NULL) {
        if (node != NULL) {
            if (nodep != NULL)
                *nodep = node;
            else
                dns_db_detachnode(db, &node);
        }
        if (dbp != NULL)
            *dbp = db;
        else
            dns_db_detach(&db);
    } else
        INSIST(node == NULL);

    if (zone != NULL)
        dns_zone_detach(&zone);

    return (result);
}

isc_result_t
dns_view_simplefind(dns_view_t *view, dns_name_t *name, dns_rdatatype_t type,
            isc_stdtime_t now, unsigned int options,
            isc_boolean_t use_hints,
            dns_rdataset_t *rdataset, dns_rdataset_t *sigrdataset)
{
    isc_result_t result;
    dns_fixedname_t foundname;

    dns_fixedname_init(&foundname);
    result = dns_view_find(view, name, type, now, options, use_hints,
                   NULL, NULL, dns_fixedname_name(&foundname),
                   rdataset, sigrdataset);
    if (result == DNS_R_NXDOMAIN) {
        /*
         * The rdataset and sigrdataset of the relevant NSEC record
         * may be returned, but the caller cannot use them because
         * foundname is not returned by this simplified API.  We
         * disassociate them here to prevent any misuse by the caller.
         */
        if (dns_rdataset_isassociated(rdataset))
            dns_rdataset_disassociate(rdataset);
        if (sigrdataset != NULL &&
            dns_rdataset_isassociated(sigrdataset))
            dns_rdataset_disassociate(sigrdataset);
    } else if (result != ISC_R_SUCCESS &&
           result != DNS_R_GLUE &&
           result != DNS_R_HINT &&
           result != DNS_R_NCACHENXDOMAIN &&
           result != DNS_R_NCACHENXRRSET &&
           result != DNS_R_NXRRSET &&
           result != DNS_R_HINTNXRRSET &&
           result != ISC_R_NOTFOUND) {
        if (dns_rdataset_isassociated(rdataset))
            dns_rdataset_disassociate(rdataset);
        if (sigrdataset != NULL &&
            dns_rdataset_isassociated(sigrdataset))
            dns_rdataset_disassociate(sigrdataset);
        result = ISC_R_NOTFOUND;
    }

    return (result);
}

isc_result_t
dns_view_findzonecut(dns_view_t *view, dns_name_t *name, dns_name_t *fname,
             isc_stdtime_t now, unsigned int options,
             isc_boolean_t use_hints,
             dns_rdataset_t *rdataset, dns_rdataset_t *sigrdataset)
{
    return(dns_view_findzonecut2(view, name, fname, now, options,
                     use_hints, ISC_TRUE,
                     rdataset, sigrdataset));
}

isc_result_t
dns_view_findzonecut2(dns_view_t *view, dns_name_t *name, dns_name_t *fname,
              isc_stdtime_t now, unsigned int options,
              isc_boolean_t use_hints,  isc_boolean_t use_cache,
              dns_rdataset_t *rdataset, dns_rdataset_t *sigrdataset)
{
    isc_result_t result;
    dns_db_t *db;
    isc_boolean_t is_cache, use_zone, try_hints;
    dns_zone_t *zone;
    dns_name_t *zfname;
    dns_rdataset_t zrdataset, zsigrdataset;
    dns_fixedname_t zfixedname;

    REQUIRE(DNS_VIEW_VALID(view));
    REQUIRE(view->frozen);

    db = NULL;
    zone = NULL;
    use_zone = ISC_FALSE;
    try_hints = ISC_FALSE;
    zfname = NULL;

    /*
     * Initialize.
     */
    dns_fixedname_init(&zfixedname);
    dns_rdataset_init(&zrdataset);
    dns_rdataset_init(&zsigrdataset);

    /*
     * Find the right database.
     */
    result = dns_zt_find(view->zonetable, name, 0, NULL, &zone);
    if (result == ISC_R_SUCCESS || result == DNS_R_PARTIALMATCH)
        result = dns_zone_getdb(zone, &db);
    if (result == ISC_R_NOTFOUND) {
        /*
         * We're not directly authoritative for this query name, nor
         * is it a subdomain of any zone for which we're
         * authoritative.
         */
        if (use_cache && view->cachedb != NULL) {
            /*
             * We have a cache; try it.
             */
            dns_db_attach(view->cachedb, &db);
        } else {
            /*
             * Maybe we have hints...
             */
            try_hints = ISC_TRUE;
            goto finish;
        }
    } else if (result != ISC_R_SUCCESS) {
        /*
         * Something is broken.
         */
        goto cleanup;
    }
    is_cache = dns_db_iscache(db);

 db_find:
    /*
     * Look for the zonecut.
     */
    if (!is_cache) {
        result = dns_db_find(db, name, NULL, dns_rdatatype_ns, options,
                     now, NULL, fname, rdataset, sigrdataset);
        if (result == DNS_R_DELEGATION)
            result = ISC_R_SUCCESS;
        else if (result != ISC_R_SUCCESS)
            goto cleanup;
        if (use_cache && view->cachedb != NULL && db != view->hints) {
            /*
             * We found an answer, but the cache may be better.
             */
            zfname = dns_fixedname_name(&zfixedname);
            result = dns_name_copy(fname, zfname, NULL);
            if (result != ISC_R_SUCCESS)
                goto cleanup;
            dns_rdataset_clone(rdataset, &zrdataset);
            dns_rdataset_disassociate(rdataset);
            if (sigrdataset != NULL &&
                dns_rdataset_isassociated(sigrdataset)) {
                dns_rdataset_clone(sigrdataset, &zsigrdataset);
                dns_rdataset_disassociate(sigrdataset);
            }
            dns_db_detach(&db);
            dns_db_attach(view->cachedb, &db);
            is_cache = ISC_TRUE;
            goto db_find;
        }
    } else {
        result = dns_db_findzonecut(db, name, options, now, NULL,
                        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) {
            if (zfname != NULL) {
                /*
                 * We didn't find anything in the cache, but we
                 * have a zone delegation, so use it.
                 */
                use_zone = ISC_TRUE;
            } else {
                /*
                 * Maybe we have hints...
                 */
                try_hints = ISC_TRUE;
            }
        } else {
            /*
             * Something bad happened.
             */
            goto cleanup;
        }
    }

 finish:
    if (use_zone) {
        if (dns_rdataset_isassociated(rdataset)) {
            dns_rdataset_disassociate(rdataset);
            if (sigrdataset != NULL &&
                dns_rdataset_isassociated(sigrdataset))
                dns_rdataset_disassociate(sigrdataset);
        }
        result = dns_name_copy(zfname, fname, NULL);
        if (result != ISC_R_SUCCESS)
            goto cleanup;
        dns_rdataset_clone(&zrdataset, rdataset);
        if (sigrdataset != NULL &&
            dns_rdataset_isassociated(&zrdataset))
            dns_rdataset_clone(&zsigrdataset, sigrdataset);
    } else if (try_hints && use_hints && view->hints != NULL) {
        /*
         * We've found nothing so far, but we have hints.
         */
        result = dns_db_find(view->hints, dns_rootname, NULL,
                     dns_rdatatype_ns, 0, now, NULL, fname,
                     rdataset, NULL);
        if (result != ISC_R_SUCCESS) {
            /*
             * We can't even find the hints for the root
             * nameservers!
             */
            if (dns_rdataset_isassociated(rdataset))
                dns_rdataset_disassociate(rdataset);
            result = ISC_R_NOTFOUND;
        }
    }

 cleanup:
    if (dns_rdataset_isassociated(&zrdataset)) {
        dns_rdataset_disassociate(&zrdataset);
        if (dns_rdataset_isassociated(&zsigrdataset))
            dns_rdataset_disassociate(&zsigrdataset);
    }
    if (db != NULL)
        dns_db_detach(&db);
    if (zone != NULL)
        dns_zone_detach(&zone);

    return (result);
}

isc_result_t
dns_viewlist_find(dns_viewlist_t *list, const char *name,
          dns_rdataclass_t rdclass, dns_view_t **viewp)
{
    dns_view_t *view;

    REQUIRE(list != NULL);

    for (view = ISC_LIST_HEAD(*list);
         view != NULL;
         view = ISC_LIST_NEXT(view, link)) {
        if (strcmp(view->name, name) == 0 && view->rdclass == rdclass)
            break;
    }
    if (view == NULL)
        return (ISC_R_NOTFOUND);

    dns_view_attach(view, viewp);

    return (ISC_R_SUCCESS);
}

isc_result_t
dns_viewlist_findzone(dns_viewlist_t *list, dns_name_t *name,
              isc_boolean_t allclasses, dns_rdataclass_t rdclass,
              dns_zone_t **zonep)
{
    dns_view_t *view;
    isc_result_t result;
    dns_zone_t *zone1 = NULL, *zone2 = NULL;

    REQUIRE(list != NULL);
    for (view = ISC_LIST_HEAD(*list);
             view != NULL;
             view = ISC_LIST_NEXT(view, link)) {
        if (allclasses == ISC_FALSE && view->rdclass != rdclass)
            continue;
        result = dns_zt_find(view->zonetable, name, 0, NULL,
                    (zone1 == NULL) ? &zone1 : &zone2);
        INSIST(result == ISC_R_SUCCESS || result == ISC_R_NOTFOUND);
        if (zone2 != NULL) {
            dns_zone_detach(&zone1);
            dns_zone_detach(&zone2);
            return (ISC_R_NOTFOUND);
        }
    }

    if (zone1 != NULL) {
        dns_zone_attach(zone1, zonep);
        dns_zone_detach(&zone1);
        return (ISC_R_SUCCESS);
    }

    return (ISC_R_NOTFOUND);
}

isc_result_t
dns_view_load(dns_view_t *view, isc_boolean_t stop) {

    REQUIRE(DNS_VIEW_VALID(view));

    return (dns_zt_load(view->zonetable, stop));
}

isc_result_t
dns_view_loadnew(dns_view_t *view, isc_boolean_t stop) {

    REQUIRE(DNS_VIEW_VALID(view));

    return (dns_zt_loadnew(view->zonetable, stop));
}

isc_result_t
dns_view_gettsig(dns_view_t *view, dns_name_t *keyname, dns_tsigkey_t **keyp)
{
    isc_result_t result;
    REQUIRE(keyp != NULL && *keyp == NULL);

    result = dns_tsigkey_find(keyp, keyname, NULL,
                  view->statickeys);
    if (result == ISC_R_NOTFOUND)
        result = dns_tsigkey_find(keyp, keyname, NULL,
                      view->dynamickeys);
    return (result);
}

isc_result_t
dns_view_getpeertsig(dns_view_t *view, isc_netaddr_t *peeraddr,
             dns_tsigkey_t **keyp)
{
    isc_result_t result;
    dns_name_t *keyname = NULL;
    dns_peer_t *peer = NULL;

    result = dns_peerlist_peerbyaddr(view->peers, peeraddr, &peer);
    if (result != ISC_R_SUCCESS)
        return (result);

    result = dns_peer_getkey(peer, &keyname);
    if (result != ISC_R_SUCCESS)
        return (result);

    return (dns_view_gettsig(view, keyname, keyp));
}

isc_result_t
dns_view_checksig(dns_view_t *view, isc_buffer_t *source, dns_message_t *msg) {
    REQUIRE(DNS_VIEW_VALID(view));
    REQUIRE(source != NULL);

    return (dns_tsig_verify(source, msg, view->statickeys,
                view->dynamickeys));
}

isc_result_t
dns_view_dumpdbtostream(dns_view_t *view, FILE *fp) {
    isc_result_t result;

    REQUIRE(DNS_VIEW_VALID(view));

    (void)fprintf(fp, ";\n; Cache dump of view '%s'\n;\n", view->name);
    result = dns_master_dumptostream(view->mctx, view->cachedb, NULL,
                      &dns_master_style_cache, fp);
    if (result != ISC_R_SUCCESS)
        return (result);
    dns_adb_dump(view->adb, fp);
    return (ISC_R_SUCCESS);
}

isc_result_t
dns_view_flushcache(dns_view_t *view) {
    isc_result_t result;

    REQUIRE(DNS_VIEW_VALID(view));

    if (view->cachedb == NULL)
        return (ISC_R_SUCCESS);
    result = dns_cache_flush(view->cache);
    if (result != ISC_R_SUCCESS)
        return (result);
    if (view->acache != NULL)
        dns_acache_putdb(view->acache, view->cachedb);
    dns_db_detach(&view->cachedb);
    dns_cache_attachdb(view->cache, &view->cachedb);
    if (view->acache != NULL)
        dns_acache_setdb(view->acache, view->cachedb);

    dns_adb_flush(view->adb);
    return (ISC_R_SUCCESS);
}

isc_result_t
dns_view_flushname(dns_view_t *view, dns_name_t *name) {

    REQUIRE(DNS_VIEW_VALID(view));

    if (view->adb != NULL)
        dns_adb_flushname(view->adb, name);
    if (view->cache == NULL)
        return (ISC_R_SUCCESS);
    return (dns_cache_flushname(view->cache, name));
}

isc_result_t
dns_view_adddelegationonly(dns_view_t *view, dns_name_t *name) {
    isc_result_t result;
    dns_name_t *new;
    isc_uint32_t hash;

    REQUIRE(DNS_VIEW_VALID(view));

    if (view->delonly == NULL) {
        view->delonly = isc_mem_get(view->mctx,
                        sizeof(dns_namelist_t) *
                        DNS_VIEW_DELONLYHASH);
        if (view->delonly == NULL)
            return (ISC_R_NOMEMORY);
        for (hash = 0; hash < DNS_VIEW_DELONLYHASH; hash++)
            ISC_LIST_INIT(view->delonly[hash]);
    }
    hash = dns_name_hash(name, ISC_FALSE) % DNS_VIEW_DELONLYHASH;
    new = ISC_LIST_HEAD(view->delonly[hash]);
    while (new != NULL && !dns_name_equal(new, name))
        new = ISC_LIST_NEXT(new, link);
    if (new != NULL)
        return (ISC_R_SUCCESS);
    new = isc_mem_get(view->mctx, sizeof(*new));
    if (new == NULL)
        return (ISC_R_NOMEMORY);
    dns_name_init(new, NULL);
    result = dns_name_dup(name, view->mctx, new);
    if (result == ISC_R_SUCCESS)
        ISC_LIST_APPEND(view->delonly[hash], new, link);
    else
        isc_mem_put(view->mctx, new, sizeof(*new));
    return (result);
}

isc_result_t
dns_view_excludedelegationonly(dns_view_t *view, dns_name_t *name) {
    isc_result_t result;
    dns_name_t *new;
    isc_uint32_t hash;

    REQUIRE(DNS_VIEW_VALID(view));

    if (view->rootexclude == NULL) {
        view->rootexclude = isc_mem_get(view->mctx,
                        sizeof(dns_namelist_t) *
                        DNS_VIEW_DELONLYHASH);
        if (view->rootexclude == NULL)
            return (ISC_R_NOMEMORY);
        for (hash = 0; hash < DNS_VIEW_DELONLYHASH; hash++)
            ISC_LIST_INIT(view->rootexclude[hash]);
    }
    hash = dns_name_hash(name, ISC_FALSE) % DNS_VIEW_DELONLYHASH;
    new = ISC_LIST_HEAD(view->rootexclude[hash]);
    while (new != NULL && !dns_name_equal(new, name))
        new = ISC_LIST_NEXT(new, link);
    if (new != NULL)
        return (ISC_R_SUCCESS);
    new = isc_mem_get(view->mctx, sizeof(*new));
    if (new == NULL)
        return (ISC_R_NOMEMORY);
    dns_name_init(new, NULL);
    result = dns_name_dup(name, view->mctx, new);
    if (result == ISC_R_SUCCESS)
        ISC_LIST_APPEND(view->rootexclude[hash], new, link);
    else
        isc_mem_put(view->mctx, new, sizeof(*new));
    return (result);
}

isc_boolean_t
dns_view_isdelegationonly(dns_view_t *view, dns_name_t *name) {
    dns_name_t *new;
    isc_uint32_t hash;

    REQUIRE(DNS_VIEW_VALID(view));

    if (!view->rootdelonly && view->delonly == NULL)
        return (ISC_FALSE);

    hash = dns_name_hash(name, ISC_FALSE) % DNS_VIEW_DELONLYHASH;
    if (view->rootdelonly && dns_name_countlabels(name) <= 2) {
        if (view->rootexclude == NULL)
            return (ISC_TRUE);
        new = ISC_LIST_HEAD(view->rootexclude[hash]);
        while (new != NULL && !dns_name_equal(new, name))
            new = ISC_LIST_NEXT(new, link);
        if (new == NULL)
            return (ISC_TRUE);
    }

    if (view->delonly == NULL)
        return (ISC_FALSE);

    new = ISC_LIST_HEAD(view->delonly[hash]);
    while (new != NULL && !dns_name_equal(new, name))
        new = ISC_LIST_NEXT(new, link);
    if (new == NULL)
        return (ISC_FALSE);
    return (ISC_TRUE);
}

void
dns_view_setrootdelonly(dns_view_t *view, isc_boolean_t value) {
    REQUIRE(DNS_VIEW_VALID(view));
    view->rootdelonly = value;
}

isc_boolean_t
dns_view_getrootdelonly(dns_view_t *view) {
    REQUIRE(DNS_VIEW_VALID(view));
    return (view->rootdelonly);
}

isc_result_t
dns_view_freezezones(dns_view_t *view, isc_boolean_t value) {
    REQUIRE(DNS_VIEW_VALID(view));
    return (dns_zt_freezezones(view->zonetable, value));
}

#ifdef HAVE_LIBXML2

struct xmlarg {
    int flags;
    xmlTextWriterPtr xml;
};

static isc_result_t
zone_xmlrender(dns_zone_t *zone, void *arg) {
    struct xmlarg *xmlarg = arg;

    return (dns_zone_xmlrender(zone, xmlarg->xml, xmlarg->flags));
}

isc_result_t
dns_view_xmlrender(dns_view_t *view, xmlTextWriterPtr xml, int flags)
{
    struct xmlarg xmlargs;

    xmlargs.flags = flags;
    xmlargs.xml = xml;

    /* XXXMLG render config data here */

    if ((flags & ISC_XML_RENDERSTATS) != 0) {
        xmlTextWriterStartElement(xml, ISC_XMLCHAR "view");

        xmlTextWriterStartElement(xml, ISC_XMLCHAR "name");
        xmlTextWriterWriteString(xml, ISC_XMLCHAR view->name);
        xmlTextWriterEndElement(xml);

        xmlTextWriterStartElement(xml, ISC_XMLCHAR "zones");
        dns_zt_apply(view->zonetable, ISC_FALSE, zone_xmlrender,
                 &xmlargs);
        xmlTextWriterEndElement(xml);

        xmlTextWriterEndElement(xml);
    }

    return (ISC_R_SUCCESS);
}

#endif /* HAVE_LIBXML2 */