lib/dns/rpz.c

	rpz.c revision 8c9fba44a41e3ea23e7e8405029980aba672f7ce
/*
 * Copyright (C) 2011-2015  Internet Systems Consortium, Inc. ("ISC")
 *
 * 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.
 */

/*! \file */

#include <config.h>

#include <isc/buffer.h>
#include <isc/mem.h>
#include <isc/net.h>
#include <isc/netaddr.h>
#include <isc/print.h>
#include <isc/rwlock.h>
#include <isc/stdlib.h>
#include <isc/string.h>
#include <isc/util.h>

#include <dns/db.h>
#include <dns/fixedname.h>
#include <dns/log.h>
#include <dns/rdata.h>
#include <dns/rdataset.h>
#include <dns/rdatastruct.h>
#include <dns/result.h>
#include <dns/rbt.h>
#include <dns/rpz.h>
#include <dns/view.h>


/*
 * Parallel radix trees for databases of response policy IP addresses
 *
 * The radix or patricia trees are somewhat specialized to handle response
 * policy addresses by representing the two sets of IP addresses and name
 * server IP addresses in a single tree.  One set of IP addresses is
 * for rpz-ip policies or policies triggered by addresses in A or
 * AAAA records in responses.
 * The second set is for rpz-nsip policies or policies triggered by addresses
 * in A or AAAA records for NS records that are authorities for responses.
 *
 * Each leaf indicates that an IP address is listed in the IP address or the
 * name server IP address policy sub-zone (or both) of the corresponding
 * response policy zone.  The policy data such as a CNAME or an A record
 * is kept in the policy zone.  After an IP address has been found in a radix
 * tree, the node in the policy zone's database is found by converting
 * the IP address to a domain name in a canonical form.
 *
 *
 * The response policy zone canonical form of an IPv6 address is one of:
 *  prefix.W.W.W.W.W.W.W.W
 *  prefix.WORDS.zz
 *  prefix.WORDS.zz.WORDS
 *  prefix.zz.WORDS
 *  where
 *  prefix  is the prefix length of the IPv6 address between 1 and 128
 *  W   is a number between 0 and 65535
 *  WORDS   is one or more numbers W separated with "."
 *  zz  corresponds to :: in the standard IPv6 text representation
 *
 * The canonical form of IPv4 addresses is:
 *  prefix.B.B.B.B
 *  where
 *  prefix  is the prefix length of the address between 1 and 32
 *  B   is a number between 0 and 255
 *
 * Names for IPv4 addresses are distinguished from IPv6 addresses by having
 * 5 labels all of which are numbers, and a prefix between 1 and 32.
 */


/*
 * Use a private definition of IPv6 addresses because s6_addr32 is not
 * always defined and our IPv6 addresses are in non-standard byte order
 */
typedef isc_uint32_t        dns_rpz_cidr_word_t;
#define DNS_RPZ_CIDR_WORD_BITS  ((int)sizeof(dns_rpz_cidr_word_t)*8)
#define DNS_RPZ_CIDR_KEY_BITS   ((int)sizeof(dns_rpz_cidr_key_t)*8)
#define DNS_RPZ_CIDR_WORDS  (128/DNS_RPZ_CIDR_WORD_BITS)
typedef struct {
    dns_rpz_cidr_word_t w[DNS_RPZ_CIDR_WORDS];
} dns_rpz_cidr_key_t;

#define ADDR_V4MAPPED       0xffff
#define KEY_IS_IPV4(prefix,ip) ((prefix) >= 96 && (ip)->w[0] == 0 &&    \
                (ip)->w[1] == 0 && (ip)->w[2] == ADDR_V4MAPPED)

#define DNS_RPZ_WORD_MASK(b) ((b) == 0 ? (dns_rpz_cidr_word_t)(-1)  \
                  : ((dns_rpz_cidr_word_t)(-1)      \
                 << (DNS_RPZ_CIDR_WORD_BITS - (b))))

/*
 * Get bit #n from the array of words of an IP address.
 */
#define DNS_RPZ_IP_BIT(ip, n) (1 & ((ip)->w[(n)/DNS_RPZ_CIDR_WORD_BITS] >>  \
                    (DNS_RPZ_CIDR_WORD_BITS         \
                     - 1 - ((n) % DNS_RPZ_CIDR_WORD_BITS))))

/*
 * A triplet of arrays of bits flagging the existence of
 * client-IP, IP, and NSIP policy triggers.
 */
typedef struct dns_rpz_addr_zbits dns_rpz_addr_zbits_t;
struct dns_rpz_addr_zbits {
    dns_rpz_zbits_t     client_ip;
    dns_rpz_zbits_t     ip;
    dns_rpz_zbits_t     nsip;
};

/*
 * A CIDR or radix tree node.
 */
struct dns_rpz_cidr_node {
    dns_rpz_cidr_node_t *parent;
    dns_rpz_cidr_node_t *child[2];
    dns_rpz_cidr_key_t  ip;
    dns_rpz_prefix_t    prefix;
    dns_rpz_addr_zbits_t    set;
    dns_rpz_addr_zbits_t    sum;
};

/*
 * A pair of arrays of bits flagging the existence of
 * QNAME and NSDNAME policy triggers.
 */
typedef struct dns_rpz_nm_zbits dns_rpz_nm_zbits_t;
struct dns_rpz_nm_zbits {
    dns_rpz_zbits_t     qname;
    dns_rpz_zbits_t     ns;
};

/*
 * The data in a RBT node has two pairs of bits for policy zones.
 * One pair is for the corresponding name of the node such as example.com
 * and the other pair is for a wildcard child such as *.example.com.
 */
typedef struct dns_rpz_nm_data dns_rpz_nm_data_t;
struct dns_rpz_nm_data {
    dns_rpz_nm_zbits_t  set;
    dns_rpz_nm_zbits_t  wild;
};

#if 0
/*
 * Catch a name while debugging.
 */
static void
catch_name(const dns_name_t *src_name, const char *tgt, const char *str) {
    dns_fixedname_t tgt_namef;
    dns_name_t *tgt_name;

    dns_fixedname_init(&tgt_namef);
    tgt_name = dns_fixedname_name(&tgt_namef);
    dns_name_fromstring(tgt_name, tgt, DNS_NAME_DOWNCASE, NULL);
    if (dns_name_equal(src_name, tgt_name)) {
        isc_log_write(dns_lctx, DNS_LOGCATEGORY_RPZ,
                  DNS_LOGMODULE_RBTDB, DNS_RPZ_ERROR_LEVEL,
                  "rpz hit failed: %s %s", str, tgt);
    }
}
#endif

const char *
dns_rpz_type2str(dns_rpz_type_t type) {
    switch (type) {
    case DNS_RPZ_TYPE_CLIENT_IP:
        return ("CLIENT-IP");
    case DNS_RPZ_TYPE_QNAME:
        return ("QNAME");
    case DNS_RPZ_TYPE_IP:
        return ("IP");
    case DNS_RPZ_TYPE_NSIP:
        return ("NSIP");
    case DNS_RPZ_TYPE_NSDNAME:
        return ("NSDNAME");
    case DNS_RPZ_TYPE_BAD:
        break;
    }
    FATAL_ERROR(__FILE__, __LINE__, "impossible rpz type %d", type);
    return ("impossible");
}

dns_rpz_policy_t
dns_rpz_str2policy(const char *str) {
    static struct {
        const char *str;
        dns_rpz_policy_t policy;
    } tbl[] = {
        {"given",   DNS_RPZ_POLICY_GIVEN},
        {"disabled",    DNS_RPZ_POLICY_DISABLED},
        {"passthru",    DNS_RPZ_POLICY_PASSTHRU},
        {"drop",    DNS_RPZ_POLICY_DROP},
        {"tcp-only",    DNS_RPZ_POLICY_TCP_ONLY},
        {"nxdomain",    DNS_RPZ_POLICY_NXDOMAIN},
        {"nodata",  DNS_RPZ_POLICY_NODATA},
        {"cname",   DNS_RPZ_POLICY_CNAME},
        {"no-op",   DNS_RPZ_POLICY_PASSTHRU},   /* old passthru */
    };
    unsigned int n;

    if (str == NULL)
        return (DNS_RPZ_POLICY_ERROR);
    for (n = 0; n < sizeof(tbl)/sizeof(tbl[0]); ++n) {
        if (!strcasecmp(tbl[n].str, str))
            return (tbl[n].policy);
    }
    return (DNS_RPZ_POLICY_ERROR);
}

const char *
dns_rpz_policy2str(dns_rpz_policy_t policy) {
    const char *str;

    switch (policy) {
    case DNS_RPZ_POLICY_PASSTHRU:
        str = "PASSTHRU";
        break;
    case DNS_RPZ_POLICY_DROP:
        str = "DROP";
        break;
    case DNS_RPZ_POLICY_TCP_ONLY:
        str = "TCP-ONLY";
        break;
    case DNS_RPZ_POLICY_NXDOMAIN:
        str = "NXDOMAIN";
        break;
    case DNS_RPZ_POLICY_NODATA:
        str = "NODATA";
        break;
    case DNS_RPZ_POLICY_RECORD:
        str = "Local-Data";
        break;
    case DNS_RPZ_POLICY_CNAME:
    case DNS_RPZ_POLICY_WILDCNAME:
        str = "CNAME";
        break;
    case DNS_RPZ_POLICY_MISS:
        str = "MISS";
        break;
    default:
        str = "";
        POST(str);
        INSIST(0);
    }
    return (str);
}

/*
 * Return the bit number of the highest set bit in 'zbit'.
 * (for example, 0x01 returns 0, 0xFF returns 7, etc.)
 */
static int
zbit_to_num(dns_rpz_zbits_t zbit) {
    dns_rpz_num_t rpz_num;

    REQUIRE(zbit != 0);
    rpz_num = 0;
#if DNS_RPZ_MAX_ZONES > 32
    if ((zbit & 0xffffffff00000000L) != 0) {
        zbit >>= 32;
        rpz_num += 32;
    }
#endif
    if ((zbit & 0xffff0000) != 0) {
        zbit >>= 16;
        rpz_num += 16;
    }
    if ((zbit & 0xff00) != 0) {
        zbit >>= 8;
        rpz_num += 8;
    }
    if ((zbit & 0xf0) != 0) {
        zbit >>= 4;
        rpz_num += 4;
    }
    if ((zbit & 0xc) != 0) {
        zbit >>= 2;
        rpz_num += 2;
    }
    if ((zbit & 2) != 0)
        ++rpz_num;
    return (rpz_num);
}

/*
 * Make a set of bit masks given one or more bits and their type.
 */
static void
make_addr_set(dns_rpz_addr_zbits_t *tgt_set, dns_rpz_zbits_t zbits,
          dns_rpz_type_t type)
{
    switch (type) {
    case DNS_RPZ_TYPE_CLIENT_IP:
        tgt_set->client_ip = zbits;
        tgt_set->ip = 0;
        tgt_set->nsip = 0;
        break;
    case DNS_RPZ_TYPE_IP:
        tgt_set->client_ip = 0;
        tgt_set->ip = zbits;
        tgt_set->nsip = 0;
        break;
    case DNS_RPZ_TYPE_NSIP:
        tgt_set->client_ip = 0;
        tgt_set->ip = 0;
        tgt_set->nsip = zbits;
        break;
    default:
        INSIST(0);
        break;
    }
}

static void
make_nm_set(dns_rpz_nm_zbits_t *tgt_set,
        dns_rpz_num_t rpz_num, dns_rpz_type_t type)
{
    switch (type) {
    case DNS_RPZ_TYPE_QNAME:
        tgt_set->qname = DNS_RPZ_ZBIT(rpz_num);
        tgt_set->ns = 0;
        break;
    case DNS_RPZ_TYPE_NSDNAME:
        tgt_set->qname = 0;
        tgt_set->ns = DNS_RPZ_ZBIT(rpz_num);
        break;
    default:
        INSIST(0);
        break;
    }
}

/*
 * Mark a node and all of its parents as having client-IP, IP, or NSIP data
 */
static void
set_sum_pair(dns_rpz_cidr_node_t *cnode) {
    dns_rpz_cidr_node_t *child;
    dns_rpz_addr_zbits_t sum;

    do {
        sum = cnode->set;

        child = cnode->child[0];
        if (child != NULL) {
            sum.client_ip |= child->sum.client_ip;
            sum.ip |= child->sum.ip;
            sum.nsip |= child->sum.nsip;
        }

        child = cnode->child[1];
        if (child != NULL) {
            sum.client_ip |= child->sum.client_ip;
            sum.ip |= child->sum.ip;
            sum.nsip |= child->sum.nsip;
        }

        if (cnode->sum.client_ip == sum.client_ip &&
            cnode->sum.ip == sum.ip &&
            cnode->sum.nsip == sum.nsip)
            break;
        cnode->sum = sum;
        cnode = cnode->parent;
    } while (cnode != NULL);
}

/* Caller must hold rpzs->maint_lock */
static void
fix_qname_skip_recurse(dns_rpz_zones_t *rpzs) {
    dns_rpz_zbits_t mask;

    /*
     * qname_wait_recurse and qname_skip_recurse are used to
     * implement the "qname-wait-recurse" config option.
     *
     * By default, "qname-wait-recurse" is yes, so no
     * processing happens without recursion. In this case,
     * qname_wait_recurse is true, and qname_skip_recurse
     * (a bit field indicating which policy zones can be
     * processed without recursion) is set to all 0's by
     * fix_qname_skip_recurse().
     *
     * When "qname-wait-recurse" is no, qname_skip_recurse may be
     * set to a non-zero value by fix_qname_skip_recurse(). The mask
     * has to have bits set for the policy zones for which
     * processing may continue without recursion, and bits cleared
     * for the rest.
     *
     * (1) The ARM says:
     *
     *   The "qname-wait-recurse no" option overrides that default
     *   behavior when recursion cannot change a non-error
     *   response. The option does not affect QNAME or client-IP
     *   triggers in policy zones listed after other zones
     *   containing IP, NSIP and NSDNAME triggers, because those may
     *   depend on the A, AAAA, and NS records that would be found
     *   during recursive resolution.
     *
     * Let's consider the following:
     *
     *     zbits_req = (rpzs->have.ipv4 | rpzs->have.ipv6 |
     *          rpzs->have.nsdname |
     *          rpzs->have.nsipv4 | rpzs->have.nsipv6);
     *
     * zbits_req now contains bits set for zones which require
     * recursion.
     *
     * But going by the description in the ARM, if the first policy
     * zone requires recursion, then all zones after that (higher
     * order bits) have to wait as well.  If the Nth zone requires
     * recursion, then (N+1)th zone onwards all need to wait.
     *
     * So mapping this, examples:
     *
     * zbits_req = 0b000  mask = 0xffffffff (no zones have to wait for
     *                   recursion)
     * zbits_req = 0b001  mask = 0x00000000 (all zones have to wait)
     * zbits_req = 0b010  mask = 0x00000001 (the first zone doesn't have to
     *                   wait, second zone onwards need
     *                   to wait)
     * zbits_req = 0b011  mask = 0x00000000 (all zones have to wait)
     * zbits_req = 0b100  mask = 0x00000011 (the 1st and 2nd zones don't
     *                   have to wait, third zone
     *                   onwards need to wait)
     *
     * More generally, we have to count the number of trailing 0
     * bits in zbits_req and only these can be processed without
     * recursion. All the rest need to wait.
     *
     * (2) The ARM says that "qname-wait-recurse no" option
     * overrides the default behavior when recursion cannot change a
     * non-error response. So, in the order of listing of policy
     * zones, within the first policy zone where recursion may be
     * required, we should first allow CLIENT-IP and QNAME policy
     * records to be attempted without recursion.
     */

    /*
     * Get a mask covering all policy zones that are not subordinate to
     * other policy zones containing triggers that require that the
     * qname be resolved before they can be checked.
     */
    rpzs->have.client_ip = rpzs->have.client_ipv4 | rpzs->have.client_ipv6;
    rpzs->have.ip = rpzs->have.ipv4 | rpzs->have.ipv6;
    rpzs->have.nsip = rpzs->have.nsipv4 | rpzs->have.nsipv6;

    if (rpzs->p.qname_wait_recurse) {
        mask = 0;
    } else {
        dns_rpz_zbits_t zbits_req;
        dns_rpz_zbits_t zbits_notreq;
        dns_rpz_zbits_t mask2;
        dns_rpz_zbits_t req_mask;

        /*
         * Get the masks of zones with policies that
         * do/don't require recursion
         */

        zbits_req = (rpzs->have.ipv4 | rpzs->have.ipv6 |
                 rpzs->have.nsdname |
                 rpzs->have.nsipv4 | rpzs->have.nsipv6);
        zbits_notreq = (rpzs->have.client_ip | rpzs->have.qname);

        if (zbits_req == 0) {
            mask = DNS_RPZ_ALL_ZBITS;
            goto set;
        }

        /*
         * req_mask is a mask covering used bits in
         * zbits_req. (For instance, 0b1 => 0b1, 0b101 => 0b111,
         * 0b11010101 => 0b11111111).
         */
        req_mask = zbits_req;
        req_mask |= req_mask >> 1;
        req_mask |= req_mask >> 2;
        req_mask |= req_mask >> 4;
        req_mask |= req_mask >> 8;
        req_mask |= req_mask >> 16;
#if DNS_RPZ_MAX_ZONES > 32
        req_mask |= req_mask >> 32;
#endif

        /*
         * There's no point in skipping recursion for a later
         * zone if it is required in a previous zone.
         */
        if ((zbits_notreq & req_mask) == 0) {
            mask = 0;
            goto set;
        }

        /*
         * This bit arithmetic creates a mask of zones in which
         * it is okay to skip recursion. After the first zone
         * that has to wait for recursion, all the others have
         * to wait as well, so we want to create a mask in which
         * all the trailing zeroes in zbits_req are are 1, and
         * more significant bits are 0. (For instance,
         * 0x0700 => 0x00ff, 0x0007 => 0x0000)
         */
        mask = ~(zbits_req | -zbits_req);

        /*
         * As mentioned in (2) above, the zone corresponding to
         * the least significant zero could have its CLIENT-IP
         * and QNAME policies checked before recursion, if it
         * has any of those policies.  So if it does, we
         * can set its 0 to 1.
         *
         * Locate the least significant 0 bit in the mask (for
         * instance, 0xff => 0x100)...
         */
        mask2 = (mask << 1) & ~mask;

        /*
         * Also set the bit for zone 0, because if it's in
         * zbits_notreq then it's definitely okay to attempt to
         * skip recursion for zone 0...
         */
        mask2 |= 1;

        /* Clear any bits *not* in zbits_notreq... */
        mask2 &= zbits_notreq;

        /* And merge the result into the skip-recursion mask */
        mask |= mask2;
    }

 set:
    isc_log_write(dns_lctx, DNS_LOGCATEGORY_RPZ, DNS_LOGMODULE_RBTDB,
              DNS_RPZ_DEBUG_QUIET,
              "computed RPZ qname_skip_recurse mask=0x%llx",
              (isc_uint64_t) mask);
    rpzs->have.qname_skip_recurse = mask;
}

static void
adj_trigger_cnt(dns_rpz_zones_t *rpzs, dns_rpz_num_t rpz_num,
        dns_rpz_type_t rpz_type,
        const dns_rpz_cidr_key_t *tgt_ip, dns_rpz_prefix_t tgt_prefix,
        isc_boolean_t inc)
{
    dns_rpz_trigger_counter_t *cnt;
    dns_rpz_zbits_t *have;

    switch (rpz_type) {
    case DNS_RPZ_TYPE_CLIENT_IP:
        REQUIRE(tgt_ip != NULL);
        if (KEY_IS_IPV4(tgt_prefix, tgt_ip)) {
            cnt = &rpzs->triggers[rpz_num].client_ipv4;
            have = &rpzs->have.client_ipv4;
        } else {
            cnt = &rpzs->triggers[rpz_num].client_ipv6;
            have = &rpzs->have.client_ipv6;
        }
        break;
    case DNS_RPZ_TYPE_QNAME:
        cnt = &rpzs->triggers[rpz_num].qname;
        have = &rpzs->have.qname;
        break;
    case DNS_RPZ_TYPE_IP:
        REQUIRE(tgt_ip != NULL);
        if (KEY_IS_IPV4(tgt_prefix, tgt_ip)) {
            cnt = &rpzs->triggers[rpz_num].ipv4;
            have = &rpzs->have.ipv4;
        } else {
            cnt = &rpzs->triggers[rpz_num].ipv6;
            have = &rpzs->have.ipv6;
        }
        break;
    case DNS_RPZ_TYPE_NSDNAME:
        cnt = &rpzs->triggers[rpz_num].nsdname;
        have = &rpzs->have.nsdname;
        break;
    case DNS_RPZ_TYPE_NSIP:
        REQUIRE(tgt_ip != NULL);
        if (KEY_IS_IPV4(tgt_prefix, tgt_ip)) {
            cnt = &rpzs->triggers[rpz_num].nsipv4;
            have = &rpzs->have.nsipv4;
        } else {
            cnt = &rpzs->triggers[rpz_num].nsipv6;
            have = &rpzs->have.nsipv6;
        }
        break;
    default:
        INSIST(0);
    }

    if (inc) {
        if (++*cnt == 1U) {
            *have |= DNS_RPZ_ZBIT(rpz_num);
            fix_qname_skip_recurse(rpzs);
        }
    } else {
        REQUIRE(*cnt != 0U);
        if (--*cnt == 0U) {
            *have &= ~DNS_RPZ_ZBIT(rpz_num);
            fix_qname_skip_recurse(rpzs);
        }
    }
}

static dns_rpz_cidr_node_t *
new_node(dns_rpz_zones_t *rpzs,
     const dns_rpz_cidr_key_t *ip, dns_rpz_prefix_t prefix,
     const dns_rpz_cidr_node_t *child)
{
    dns_rpz_cidr_node_t *new;
    int i, words, wlen;

    new = isc_mem_get(rpzs->mctx, sizeof(*new));
    if (new == NULL)
        return (NULL);
    memset(new, 0, sizeof(*new));

    if (child != NULL)
        new->sum = child->sum;

    new->prefix = prefix;
    words = prefix / DNS_RPZ_CIDR_WORD_BITS;
    wlen = prefix % DNS_RPZ_CIDR_WORD_BITS;
    i = 0;
    while (i < words) {
        new->ip.w[i] = ip->w[i];
        ++i;
    }
    if (wlen != 0) {
        new->ip.w[i] = ip->w[i] & DNS_RPZ_WORD_MASK(wlen);
        ++i;
    }
    while (i < DNS_RPZ_CIDR_WORDS)
        new->ip.w[i++] = 0;

    return (new);
}

static void
badname(int level, dns_name_t *name, const char *str1, const char *str2) {
    char namebuf[DNS_NAME_FORMATSIZE];

    /*
     * bin/tests/system/rpz/tests.sh looks for "invalid rpz".
     */
    if (level < DNS_RPZ_DEBUG_QUIET &&
        isc_log_wouldlog(dns_lctx, level)) {
        dns_name_format(name, namebuf, sizeof(namebuf));
        isc_log_write(dns_lctx, DNS_LOGCATEGORY_RPZ,
                  DNS_LOGMODULE_RBTDB, level,
                  "invalid rpz IP address \"%s\"%s%s",
                  namebuf, str1, str2);
    }
}

/*
 * Convert an IP address from radix tree binary (host byte order) to
 * to its canonical response policy domain name without the origin of the
 * policy zone.
 */
static isc_result_t
ip2name(const dns_rpz_cidr_key_t *tgt_ip, dns_rpz_prefix_t tgt_prefix,
    dns_name_t *base_name, dns_name_t *ip_name)
{
#ifndef INET6_ADDRSTRLEN
#define INET6_ADDRSTRLEN 46
#endif
    int w[DNS_RPZ_CIDR_WORDS*2];
    char str[1+8+1+INET6_ADDRSTRLEN+1];
    isc_buffer_t buffer;
    isc_result_t result;
    isc_boolean_t zeros;
    int i, n, len;

    if (KEY_IS_IPV4(tgt_prefix, tgt_ip)) {
        len = snprintf(str, sizeof(str), "%d.%d.%d.%d.%d",
                   tgt_prefix - 96,
                   tgt_ip->w[3] & 0xff,
                   (tgt_ip->w[3]>>8) & 0xff,
                   (tgt_ip->w[3]>>16) & 0xff,
                   (tgt_ip->w[3]>>24) & 0xff);
        if (len < 0 || len > (int)sizeof(str))
            return (ISC_R_FAILURE);
    } else {
        for (i = 0; i < DNS_RPZ_CIDR_WORDS; i++) {
            w[i*2+1] = ((tgt_ip->w[DNS_RPZ_CIDR_WORDS-1-i] >> 16)
                    & 0xffff);
            w[i*2] = tgt_ip->w[DNS_RPZ_CIDR_WORDS-1-i] & 0xffff;
        }
        zeros = ISC_FALSE;
        len = snprintf(str, sizeof(str), "%d", tgt_prefix);
        if (len == -1)
            return (ISC_R_FAILURE);
        i = 0;
        while (i < DNS_RPZ_CIDR_WORDS * 2) {
            if (w[i] != 0 || zeros ||
                i >= DNS_RPZ_CIDR_WORDS * 2 - 1 ||
                w[i+1] != 0) {
                INSIST((size_t)len <= sizeof(str));
                n = snprintf(&str[len], sizeof(str) - len,
                         ".%x", w[i++]);
                if (n < 0)
                    return (ISC_R_FAILURE);
                len += n;
            } else {
                zeros = ISC_TRUE;
                INSIST((size_t)len <= sizeof(str));
                n = snprintf(&str[len], sizeof(str) - len,
                         ".zz");
                if (n < 0)
                    return (ISC_R_FAILURE);
                len += n;
                i += 2;
                while (i < DNS_RPZ_CIDR_WORDS * 2 && w[i] == 0)
                    ++i;
            }
            if (len >= (int)sizeof(str))
                return (ISC_R_FAILURE);
        }
    }

    isc_buffer_init(&buffer, str, sizeof(str));
    isc_buffer_add(&buffer, len);
    result = dns_name_fromtext(ip_name, &buffer, base_name, 0, NULL);
    return (result);
}

/*
 * Determine the type a of a name in a response policy zone.
 */
static dns_rpz_type_t
type_from_name(dns_rpz_zone_t *rpz, dns_name_t *name) {

    if (dns_name_issubdomain(name, &rpz->ip))
        return (DNS_RPZ_TYPE_IP);

    if (dns_name_issubdomain(name, &rpz->client_ip))
        return (DNS_RPZ_TYPE_CLIENT_IP);

#ifdef ENABLE_RPZ_NSIP
    if (dns_name_issubdomain(name, &rpz->nsip))
        return (DNS_RPZ_TYPE_NSIP);
#endif

#ifdef ENABLE_RPZ_NSDNAME
    if (dns_name_issubdomain(name, &rpz->nsdname))
        return (DNS_RPZ_TYPE_NSDNAME);
#endif

    return (DNS_RPZ_TYPE_QNAME);
}

/*
 * Convert an IP address from canonical response policy domain name form
 * to radix tree binary (host byte order) for adding or deleting IP or NSIP
 * data.
 */
static isc_result_t
name2ipkey(int log_level,
       const dns_rpz_zones_t *rpzs, dns_rpz_num_t rpz_num,
       dns_rpz_type_t rpz_type, dns_name_t *src_name,
       dns_rpz_cidr_key_t *tgt_ip, dns_rpz_prefix_t *tgt_prefix,
       dns_rpz_addr_zbits_t *new_set)
{
    dns_rpz_zone_t *rpz;
    char ip_str[DNS_NAME_FORMATSIZE];
    dns_offsets_t ip_name_offsets;
    dns_fixedname_t ip_name2f;
    dns_name_t ip_name, *ip_name2;
    const char *prefix_str, *cp, *end;
    char *cp2;
    int ip_labels;
    dns_rpz_prefix_t prefix;
    unsigned long prefix_num, l;
    isc_result_t result;
    int i;

    REQUIRE(rpzs != NULL && rpz_num < rpzs->p.num_zones);
    rpz = rpzs->zones[rpz_num];
    REQUIRE(rpz != NULL);

    make_addr_set(new_set, DNS_RPZ_ZBIT(rpz_num), rpz_type);

    ip_labels = dns_name_countlabels(src_name);
    if (rpz_type == DNS_RPZ_TYPE_QNAME)
        ip_labels -= dns_name_countlabels(&rpz->origin);
    else
        ip_labels -= dns_name_countlabels(&rpz->nsdname);
    if (ip_labels < 2) {
        badname(log_level, src_name, "; too short", "");
        return (ISC_R_FAILURE);
    }
    dns_name_init(&ip_name, ip_name_offsets);
    dns_name_getlabelsequence(src_name, 0, ip_labels, &ip_name);

    /*
     * Get text for the IP address
     */
    dns_name_format(&ip_name, ip_str, sizeof(ip_str));
    end = &ip_str[strlen(ip_str)+1];
    prefix_str = ip_str;

    prefix_num = strtoul(prefix_str, &cp2, 10);
    if (*cp2 != '.') {
        badname(log_level, src_name,
            "; invalid leading prefix length", "");
        return (ISC_R_FAILURE);
    }
    *cp2 = '\0';
    if (prefix_num < 1U || prefix_num > 128U) {
        badname(log_level, src_name,
            "; invalid prefix length of ", prefix_str);
        return (ISC_R_FAILURE);
    }
    cp = cp2+1;

    if (--ip_labels == 4 && !strchr(cp, 'z')) {
        /*
         * Convert an IPv4 address
         * from the form "prefix.z.y.x.w"
         */
        if (prefix_num > 32U) {
            badname(log_level, src_name,
                "; invalid IPv4 prefix length of ", prefix_str);
            return (ISC_R_FAILURE);
        }
        prefix_num += 96;
        *tgt_prefix = (dns_rpz_prefix_t)prefix_num;
        tgt_ip->w[0] = 0;
        tgt_ip->w[1] = 0;
        tgt_ip->w[2] = ADDR_V4MAPPED;
        tgt_ip->w[3] = 0;
        for (i = 0; i < 32; i += 8) {
            l = strtoul(cp, &cp2, 10);
            if (l > 255U || (*cp2 != '.' && *cp2 != '\0')) {
                if (*cp2 == '.')
                    *cp2 = '\0';
                badname(log_level, src_name,
                    "; invalid IPv4 octet ", cp);
                return (ISC_R_FAILURE);
            }
            tgt_ip->w[3] |= l << i;
            cp = cp2 + 1;
        }
    } else {
        /*
         * Convert a text IPv6 address.
         */
        *tgt_prefix = (dns_rpz_prefix_t)prefix_num;
        for (i = 0;
             ip_labels > 0 && i < DNS_RPZ_CIDR_WORDS * 2;
             ip_labels--) {
            if (cp[0] == 'z' && cp[1] == 'z' &&
                (cp[2] == '.' || cp[2] == '\0') &&
                i <= 6) {
                do {
                    if ((i & 1) == 0)
                        tgt_ip->w[3-i/2] = 0;
                    ++i;
                } while (ip_labels + i <= 8);
                cp += 3;
            } else {
                l = strtoul(cp, &cp2, 16);
                if (l > 0xffffu ||
                    (*cp2 != '.' && *cp2 != '\0')) {
                    if (*cp2 == '.')
                        *cp2 = '\0';
                    badname(log_level, src_name,
                        "; invalid IPv6 word ", cp);
                    return (ISC_R_FAILURE);
                }
                if ((i & 1) == 0)
                    tgt_ip->w[3-i/2] = l;
                else
                    tgt_ip->w[3-i/2] |= l << 16;
                i++;
                cp = cp2 + 1;
            }
        }
    }
    if (cp != end) {
        badname(log_level, src_name, "", "");
        return (ISC_R_FAILURE);
    }

    /*
     * Check for 1s after the prefix length.
     */
    prefix = (dns_rpz_prefix_t)prefix_num;
    while (prefix < DNS_RPZ_CIDR_KEY_BITS) {
        dns_rpz_cidr_word_t aword;

        i = prefix % DNS_RPZ_CIDR_WORD_BITS;
        aword = tgt_ip->w[prefix / DNS_RPZ_CIDR_WORD_BITS];
        if ((aword & ~DNS_RPZ_WORD_MASK(i)) != 0) {
            badname(log_level, src_name,
                "; too small prefix length of ", prefix_str);
            return (ISC_R_FAILURE);
        }
        prefix -= i;
        prefix += DNS_RPZ_CIDR_WORD_BITS;
    }

    /*
     * XXXMUKS: Should the following check be enabled in a
     * production build?  It can be expensive for large IP zones
     * from 3rd parties.
     */

    /*
     * Convert the address back to a canonical domain name
     * to ensure that the original name is in canonical form.
     */
    dns_fixedname_init(&ip_name2f);
    ip_name2 = dns_fixedname_name(&ip_name2f);
    result = ip2name(tgt_ip, (dns_rpz_prefix_t)prefix_num, NULL, ip_name2);
    if (result != ISC_R_SUCCESS || !dns_name_equal(&ip_name, ip_name2)) {
        badname(log_level, src_name, "; not canonical", "");
        return (ISC_R_FAILURE);
    }

    return (ISC_R_SUCCESS);
}

/*
 * Get trigger name and data bits for adding or deleting summary NSDNAME
 * or QNAME data.
 */
static void
name2data(dns_rpz_zones_t *rpzs, dns_rpz_num_t rpz_num,
      dns_rpz_type_t rpz_type, const dns_name_t *src_name,
      dns_name_t *trig_name, dns_rpz_nm_data_t *new_data)
{
    dns_rpz_zone_t *rpz;
    dns_offsets_t tmp_name_offsets;
    dns_name_t tmp_name;
    unsigned int prefix_len, n;

    REQUIRE(rpzs != NULL && rpz_num < rpzs->p.num_zones);
    rpz = rpzs->zones[rpz_num];
    REQUIRE(rpz != NULL);

    /*
     * Handle wildcards by putting only the parent into the
     * summary RBT.  The summary database only causes a check of the
     * real policy zone where wildcards will be handled.
     */
    if (dns_name_iswildcard(src_name)) {
        prefix_len = 1;
        memset(&new_data->set, 0, sizeof(new_data->set));
        make_nm_set(&new_data->wild, rpz_num, rpz_type);
    } else {
        prefix_len = 0;
        make_nm_set(&new_data->set, rpz_num, rpz_type);
        memset(&new_data->wild, 0, sizeof(new_data->wild));
    }

    dns_name_init(&tmp_name, tmp_name_offsets);
    n = dns_name_countlabels(src_name);
    n -= prefix_len;
    if (rpz_type == DNS_RPZ_TYPE_QNAME)
        n -= dns_name_countlabels(&rpz->origin);
    else
        n -= dns_name_countlabels(&rpz->nsdname);
    dns_name_getlabelsequence(src_name, prefix_len, n, &tmp_name);
    (void)dns_name_concatenate(&tmp_name, dns_rootname, trig_name, NULL);
}

/*
 * Find the first differing bit in a key (IP address) word.
 */
static inline int
ffs_keybit(dns_rpz_cidr_word_t w) {
    int bit;

    bit = DNS_RPZ_CIDR_WORD_BITS-1;
    if ((w & 0xffff0000) != 0) {
        w >>= 16;
        bit -= 16;
    }
    if ((w & 0xff00) != 0) {
        w >>= 8;
        bit -= 8;
    }
    if ((w & 0xf0) != 0) {
        w >>= 4;
        bit -= 4;
    }
    if ((w & 0xc) != 0) {
        w >>= 2;
        bit -= 2;
    }
    if ((w & 2) != 0)
        --bit;
    return (bit);
}

/*
 * Find the first differing bit in two keys (IP addresses).
 */
static int
diff_keys(const dns_rpz_cidr_key_t *key1, dns_rpz_prefix_t prefix1,
      const dns_rpz_cidr_key_t *key2, dns_rpz_prefix_t prefix2)
{
    dns_rpz_cidr_word_t delta;
    dns_rpz_prefix_t maxbit, bit;
    int i;

    bit = 0;
    maxbit = ISC_MIN(prefix1, prefix2);

    /*
     * find the first differing words
     */
    for (i = 0;
         bit < maxbit;
         i++, bit += DNS_RPZ_CIDR_WORD_BITS) {
        delta = key1->w[i] ^ key2->w[i];
        if (delta != 0) {
            bit += ffs_keybit(delta);
            break;
        }
    }
    return (ISC_MIN(bit, maxbit));
}

/*
 * Given a hit while searching the radix trees,
 * clear all bits for higher numbered zones.
 */
static inline dns_rpz_zbits_t
trim_zbits(dns_rpz_zbits_t zbits, dns_rpz_zbits_t found) {
    dns_rpz_zbits_t x;

    /*
     * Isolate the first or smallest numbered hit bit.
     * Make a mask of that bit and all smaller numbered bits.
     */
    x = zbits & found;
    x &= (~x + 1);
    x = (x << 1) - 1;
    return (zbits &= x);
}

/*
 * Search a radix tree for an IP address for ordinary lookup
 *  or for a CIDR block adding or deleting an entry
 *
 * Return ISC_R_SUCCESS, DNS_R_PARTIALMATCH, ISC_R_NOTFOUND,
 *      and *found=longest match node
 *  or with create==ISC_TRUE, ISC_R_EXISTS or ISC_R_NOMEMORY
 */
static isc_result_t
search(dns_rpz_zones_t *rpzs,
       const dns_rpz_cidr_key_t *tgt_ip, dns_rpz_prefix_t tgt_prefix,
       const dns_rpz_addr_zbits_t *tgt_set, isc_boolean_t create,
       dns_rpz_cidr_node_t **found)
{
    dns_rpz_cidr_node_t *cur, *parent, *child, *new_parent, *sibling;
    dns_rpz_addr_zbits_t set;
    int cur_num, child_num;
    dns_rpz_prefix_t dbit;
    isc_result_t find_result;

    set = *tgt_set;
    find_result = ISC_R_NOTFOUND;
    *found = NULL;
    cur = rpzs->cidr;
    parent = NULL;
    cur_num = 0;
    for (;;) {
        if (cur == NULL) {
            /*
             * No child so we cannot go down.
             * Quit with whatever we already found
             * or add the target as a child of the current parent.
             */
            if (!create)
                return (find_result);
            child = new_node(rpzs, tgt_ip, tgt_prefix, NULL);
            if (child == NULL)
                return (ISC_R_NOMEMORY);
            if (parent == NULL)
                rpzs->cidr = child;
            else
                parent->child[cur_num] = child;
            child->parent = parent;
            child->set.client_ip |= tgt_set->client_ip;
            child->set.ip |= tgt_set->ip;
            child->set.nsip |= tgt_set->nsip;
            set_sum_pair(child);
            *found = child;
            return (ISC_R_SUCCESS);
        }

        if ((cur->sum.client_ip & set.client_ip) == 0 &&
            (cur->sum.ip & set.ip) == 0 &&
            (cur->sum.nsip & set.nsip) == 0) {
            /*
             * This node has no relevant data
             * and is in none of the target trees.
             * Pretend it does not exist if we are not adding.
             *
             * If we are adding, continue down to eventually add
             * a node and mark/put this node in the correct tree.
             */
            if (!create)
                return (find_result);
        }

        dbit = diff_keys(tgt_ip, tgt_prefix, &cur->ip, cur->prefix);
        /*
         * dbit <= tgt_prefix and dbit <= cur->prefix always.
         * We are finished searching if we matched all of the target.
         */
        if (dbit == tgt_prefix) {
            if (tgt_prefix == cur->prefix) {
                /*
                 * The node's key matches the target exactly.
                 */
                if ((cur->set.client_ip & set.client_ip) != 0 ||
                    (cur->set.ip & set.ip) != 0 ||
                    (cur->set.nsip & set.nsip) != 0) {
                    /*
                     * It is the answer if it has data.
                     */
                    *found = cur;
                    if (create) {
                        find_result = ISC_R_EXISTS;
                    } else {
                        find_result = ISC_R_SUCCESS;
                    }
                } else if (create) {
                    /*
                     * The node lacked relevant data,
                     * but will have it now.
                     */
                    cur->set.client_ip |= tgt_set->client_ip;
                    cur->set.ip |= tgt_set->ip;
                    cur->set.nsip |= tgt_set->nsip;
                    set_sum_pair(cur);
                    *found = cur;
                    find_result = ISC_R_SUCCESS;
                }
                return (find_result);
            }

            /*
             * We know tgt_prefix < cur->prefix which means that
             * the target is shorter than the current node.
             * Add the target as the current node's parent.
             */
            if (!create)
                return (find_result);

            new_parent = new_node(rpzs, tgt_ip, tgt_prefix, cur);
            if (new_parent == NULL)
                return (ISC_R_NOMEMORY);
            new_parent->parent = parent;
            if (parent == NULL)
                rpzs->cidr = new_parent;
            else
                parent->child[cur_num] = new_parent;
            child_num = DNS_RPZ_IP_BIT(&cur->ip, tgt_prefix+1);
            new_parent->child[child_num] = cur;
            cur->parent = new_parent;
            new_parent->set = *tgt_set;
            set_sum_pair(new_parent);
            *found = new_parent;
            return (ISC_R_SUCCESS);
        }

        if (dbit == cur->prefix) {
            if ((cur->set.client_ip & set.client_ip) != 0 ||
                (cur->set.ip & set.ip) != 0 ||
                (cur->set.nsip & set.nsip) != 0) {
                /*
                 * We have a partial match between of all of the
                 * current node but only part of the target.
                 * Continue searching for other hits in the
                 * same or lower numbered trees.
                 */
                find_result = DNS_R_PARTIALMATCH;
                *found = cur;
                set.client_ip = trim_zbits(set.client_ip,
                               cur->set.client_ip);
                set.ip = trim_zbits(set.ip,
                            cur->set.ip);
                set.nsip = trim_zbits(set.nsip,
                              cur->set.nsip);
            }
            parent = cur;
            cur_num = DNS_RPZ_IP_BIT(tgt_ip, dbit);
            cur = cur->child[cur_num];
            continue;
        }


        /*
         * dbit < tgt_prefix and dbit < cur->prefix,
         * so we failed to match both the target and the current node.
         * Insert a fork of a parent above the current node and
         * add the target as a sibling of the current node
         */
        if (!create)
            return (find_result);

        sibling = new_node(rpzs, tgt_ip, tgt_prefix, NULL);
        if (sibling == NULL)
            return (ISC_R_NOMEMORY);
        new_parent = new_node(rpzs, tgt_ip, dbit, cur);
        if (new_parent == NULL) {
            isc_mem_put(rpzs->mctx, sibling, sizeof(*sibling));
            return (ISC_R_NOMEMORY);
        }
        new_parent->parent = parent;
        if (parent == NULL)
            rpzs->cidr = new_parent;
        else
            parent->child[cur_num] = new_parent;
        child_num = DNS_RPZ_IP_BIT(tgt_ip, dbit);
        new_parent->child[child_num] = sibling;
        new_parent->child[1-child_num] = cur;
        cur->parent = new_parent;
        sibling->parent = new_parent;
        sibling->set = *tgt_set;
        set_sum_pair(sibling);
        *found = sibling;
        return (ISC_R_SUCCESS);
    }
}

/*
 * Add an IP address to the radix tree.
 */
static isc_result_t
add_cidr(dns_rpz_zones_t *rpzs, dns_rpz_num_t rpz_num,
     dns_rpz_type_t rpz_type, dns_name_t *src_name)
{
    dns_rpz_cidr_key_t tgt_ip;
    dns_rpz_prefix_t tgt_prefix;
    dns_rpz_addr_zbits_t set;
    dns_rpz_cidr_node_t *found;
    isc_result_t result;

    result = name2ipkey(DNS_RPZ_ERROR_LEVEL, rpzs, rpz_num, rpz_type,
                src_name, &tgt_ip, &tgt_prefix, &set);
    /*
     * Log complaints about bad owner names but let the zone load.
     */
    if (result != ISC_R_SUCCESS)
        return (ISC_R_SUCCESS);

    result = search(rpzs, &tgt_ip, tgt_prefix, &set, ISC_TRUE, &found);
    if (result != ISC_R_SUCCESS) {
        char namebuf[DNS_NAME_FORMATSIZE];

        /*
         * Do not worry if the radix tree already exists,
         * because diff_apply() likes to add nodes before deleting.
         */
        if (result == ISC_R_EXISTS)
            return (ISC_R_SUCCESS);

        /*
         * bin/tests/system/rpz/tests.sh looks for "rpz.*failed".
         */
        dns_name_format(src_name, namebuf, sizeof(namebuf));
        isc_log_write(dns_lctx, DNS_LOGCATEGORY_RPZ,
                  DNS_LOGMODULE_RBTDB, DNS_RPZ_ERROR_LEVEL,
                  "rpz add_cidr(%s) failed: %s",
                  namebuf, isc_result_totext(result));
        return (result);
    }

    adj_trigger_cnt(rpzs, rpz_num, rpz_type, &tgt_ip, tgt_prefix, ISC_TRUE);
    return (result);
}

static isc_result_t
add_nm(dns_rpz_zones_t *rpzs, dns_name_t *trig_name,
     const dns_rpz_nm_data_t *new_data)
{
    dns_rbtnode_t *nmnode;
    dns_rpz_nm_data_t *nm_data;
    isc_result_t result;

    nmnode = NULL;
    result = dns_rbt_addnode(rpzs->rbt, trig_name, &nmnode);
    switch (result) {
    case ISC_R_SUCCESS:
    case ISC_R_EXISTS:
        nm_data = nmnode->data;
        if (nm_data == NULL) {
            nm_data = isc_mem_get(rpzs->mctx, sizeof(*nm_data));
            if (nm_data == NULL)
                return (ISC_R_NOMEMORY);
            *nm_data = *new_data;
            nmnode->data = nm_data;
            return (ISC_R_SUCCESS);
        }
        break;
    default:
        return (result);
    }

    /*
     * Do not count bits that are already present
     */
    if ((nm_data->set.qname & new_data->set.qname) != 0 ||
        (nm_data->set.ns & new_data->set.ns) != 0 ||
        (nm_data->wild.qname & new_data->wild.qname) != 0 ||
        (nm_data->wild.ns & new_data->wild.ns) != 0)
        return (ISC_R_EXISTS);

    nm_data->set.qname |= new_data->set.qname;
    nm_data->set.ns |= new_data->set.ns;
    nm_data->wild.qname |= new_data->wild.qname;
    nm_data->wild.ns |= new_data->wild.ns;
    return (ISC_R_SUCCESS);
}

static isc_result_t
add_name(dns_rpz_zones_t *rpzs, dns_rpz_num_t rpz_num,
     dns_rpz_type_t rpz_type, dns_name_t *src_name)
{
    dns_rpz_nm_data_t new_data;
    dns_fixedname_t trig_namef;
    dns_name_t *trig_name;
    isc_result_t result;

    /*
     * No need for a summary database of names with only 1 policy zone.
     */
    if (rpzs->p.num_zones <= 1) {
        adj_trigger_cnt(rpzs, rpz_num, rpz_type, NULL, 0, ISC_TRUE);
        return (ISC_R_SUCCESS);
    }

    dns_fixedname_init(&trig_namef);
    trig_name = dns_fixedname_name(&trig_namef);
    name2data(rpzs, rpz_num, rpz_type, src_name, trig_name, &new_data);

    result = add_nm(rpzs, trig_name, &new_data);

    /*
     * Do not worry if the node already exists,
     * because diff_apply() likes to add nodes before deleting.
     */
    if (result == ISC_R_EXISTS)
        return (ISC_R_SUCCESS);
    if (result == ISC_R_SUCCESS)
        adj_trigger_cnt(rpzs, rpz_num, rpz_type, NULL, 0, ISC_TRUE);
    return (result);
}

/*
 * Callback to free the data for a node in the summary RBT database.
 */
static void
rpz_node_deleter(void *nm_data, void *mctx) {
    isc_mem_put(mctx, nm_data, sizeof(dns_rpz_nm_data_t));
}

/*
 * Get ready for a new set of policy zones.
 */
isc_result_t
dns_rpz_new_zones(dns_rpz_zones_t **rpzsp, isc_mem_t *mctx) {
    dns_rpz_zones_t *new;
    isc_result_t result;

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

    *rpzsp = NULL;

    new = isc_mem_get(mctx, sizeof(*new));
    if (new == NULL)
        return (ISC_R_NOMEMORY);
    memset(new, 0, sizeof(*new));

    result = isc_rwlock_init(&new->search_lock, 0, 0);
    if (result != ISC_R_SUCCESS) {
        isc_mem_put(mctx, new, sizeof(*new));
        return (result);
    }

    result = isc_mutex_init(&new->maint_lock);
    if (result != ISC_R_SUCCESS) {
        isc_rwlock_destroy(&new->search_lock);
        isc_mem_put(mctx, new, sizeof(*new));
        return (result);
    }

    result = isc_refcount_init(&new->refs, 1);
    if (result != ISC_R_SUCCESS) {
        DESTROYLOCK(&new->maint_lock);
        isc_rwlock_destroy(&new->search_lock);
        isc_mem_put(mctx, new, sizeof(*new));
        return (result);
    }

    result = dns_rbt_create(mctx, rpz_node_deleter, mctx, &new->rbt);
    if (result != ISC_R_SUCCESS) {
        isc_refcount_decrement(&new->refs, NULL);
        isc_refcount_destroy(&new->refs);
        DESTROYLOCK(&new->maint_lock);
        isc_rwlock_destroy(&new->search_lock);
        isc_mem_put(mctx, new, sizeof(*new));
        return (result);
    }

    isc_mem_attach(mctx, &new->mctx);

    *rpzsp = new;
    return (ISC_R_SUCCESS);
}

/*
 * Free the radix tree of a response policy database.
 */
static void
cidr_free(dns_rpz_zones_t *rpzs) {
    dns_rpz_cidr_node_t *cur, *child, *parent;

    cur = rpzs->cidr;
    while (cur != NULL) {
        /* Depth first. */
        child = cur->child[0];
        if (child != NULL) {
            cur = child;
            continue;
        }
        child = cur->child[1];
        if (child != NULL) {
            cur = child;
            continue;
        }

        /* Delete this leaf and go up. */
        parent = cur->parent;
        if (parent == NULL)
            rpzs->cidr = NULL;
        else
            parent->child[parent->child[1] == cur] = NULL;
        isc_mem_put(rpzs->mctx, cur, sizeof(*cur));
        cur = parent;
    }
}

/*
 * Discard a response policy zone blob
 * before discarding the overall rpz structure.
 */
static void
rpz_detach(dns_rpz_zone_t **rpzp, dns_rpz_zones_t *rpzs) {
    dns_rpz_zone_t *rpz;
    unsigned int refs;

    rpz = *rpzp;
    *rpzp = NULL;
    isc_refcount_decrement(&rpz->refs, &refs);
    if (refs != 0)
        return;
    isc_refcount_destroy(&rpz->refs);

    if (dns_name_dynamic(&rpz->origin))
        dns_name_free(&rpz->origin, rpzs->mctx);
    if (dns_name_dynamic(&rpz->client_ip))
        dns_name_free(&rpz->client_ip, rpzs->mctx);
    if (dns_name_dynamic(&rpz->ip))
        dns_name_free(&rpz->ip, rpzs->mctx);
    if (dns_name_dynamic(&rpz->nsdname))
        dns_name_free(&rpz->nsdname, rpzs->mctx);
    if (dns_name_dynamic(&rpz->nsip))
        dns_name_free(&rpz->nsip, rpzs->mctx);
    if (dns_name_dynamic(&rpz->passthru))
        dns_name_free(&rpz->passthru, rpzs->mctx);
    if (dns_name_dynamic(&rpz->drop))
        dns_name_free(&rpz->drop, rpzs->mctx);
    if (dns_name_dynamic(&rpz->tcp_only))
        dns_name_free(&rpz->tcp_only, rpzs->mctx);
    if (dns_name_dynamic(&rpz->cname))
        dns_name_free(&rpz->cname, rpzs->mctx);

    isc_mem_put(rpzs->mctx, rpz, sizeof(*rpz));
}

void
dns_rpz_attach_rpzs(dns_rpz_zones_t *rpzs, dns_rpz_zones_t **rpzsp) {
    REQUIRE(rpzsp != NULL && *rpzsp == NULL);
    isc_refcount_increment(&rpzs->refs, NULL);
    *rpzsp = rpzs;
}

/*
 * Forget a view's policy zones.
 */
void
dns_rpz_detach_rpzs(dns_rpz_zones_t **rpzsp) {
    dns_rpz_zones_t *rpzs;
    dns_rpz_zone_t *rpz;
    dns_rpz_num_t rpz_num;
    unsigned int refs;

    REQUIRE(rpzsp != NULL);
    rpzs = *rpzsp;
    REQUIRE(rpzs != NULL);

    *rpzsp = NULL;
    isc_refcount_decrement(&rpzs->refs, &refs);

    /*
     * Forget the last of view's rpz machinery after the last reference.
     */
    if (refs == 0) {
        for (rpz_num = 0; rpz_num < DNS_RPZ_MAX_ZONES; ++rpz_num) {
            rpz = rpzs->zones[rpz_num];
            rpzs->zones[rpz_num] = NULL;
            if (rpz != NULL)
                rpz_detach(&rpz, rpzs);
        }

        cidr_free(rpzs);
        dns_rbt_destroy(&rpzs->rbt);
        DESTROYLOCK(&rpzs->maint_lock);
        isc_rwlock_destroy(&rpzs->search_lock);
        isc_refcount_destroy(&rpzs->refs);
        isc_mem_putanddetach(&rpzs->mctx, rpzs, sizeof(*rpzs));
    }
}

/*
 * Create empty summary database to load one zone.
 * The RBTDB write tree lock must be held.
 */
isc_result_t
dns_rpz_beginload(dns_rpz_zones_t **load_rpzsp,
          dns_rpz_zones_t *rpzs, dns_rpz_num_t rpz_num)
{
    dns_rpz_zones_t *load_rpzs;
    dns_rpz_zone_t *rpz;
    dns_rpz_zbits_t tgt;
    isc_result_t result;

    REQUIRE(rpz_num < rpzs->p.num_zones);
    rpz = rpzs->zones[rpz_num];
    REQUIRE(rpz != NULL);

    /*
     * When reloading a zone, there are usually records among the summary
     * data for the zone.  Some of those records might be deleted by the
     * reloaded zone data.  To deal with that case:
     *    reload the new zone data into a new blank summary database
     *    if the reload fails, discard the new summary database
     *    if the new zone data is acceptable, copy the records for the
     *  other zones into the new summary CIDR and RBT databases
     *  and replace the old summary databases with the new, and
     *  correct the triggers and have values for the updated
     *  zone.
     *
     * At the first attempt to load a zone, there is no summary data
     * for the zone and so no records that need to be deleted.
     * This is also the most common case of policy zone loading.
     * Most policy zone maintenance should be by incremental changes
     * and so by the addition and deletion of individual records.
     * Detect that case and load records the first time into the
     * operational summary database
     */
    tgt = DNS_RPZ_ZBIT(rpz_num);
    LOCK(&rpzs->maint_lock);
    RWLOCK(&rpzs->search_lock, isc_rwlocktype_write);
    if ((rpzs->load_begun & tgt) == 0) {
        /*
         * There is no existing version of the target zone.
         */
        rpzs->load_begun |= tgt;
        dns_rpz_attach_rpzs(rpzs, load_rpzsp);
    } else {
        /*
         * Setup the new RPZ struct with empty summary trees.
         */
        result = dns_rpz_new_zones(load_rpzsp, rpzs->mctx);
        if (result != ISC_R_SUCCESS)
            return (result);
        load_rpzs = *load_rpzsp;
        /*
         * Initialize some members so that dns_rpz_add() works.
         */
        load_rpzs->p.num_zones = rpzs->p.num_zones;
        memset(&load_rpzs->triggers, 0, sizeof(load_rpzs->triggers));
        load_rpzs->zones[rpz_num] = rpz;
        isc_refcount_increment(&rpz->refs, NULL);
    }

    RWUNLOCK(&rpzs->search_lock, isc_rwlocktype_write);
    UNLOCK(&rpzs->maint_lock);

    return (ISC_R_SUCCESS);
}

/*
 * This function updates "have" bits and also the qname_skip_recurse
 * mask. It must be called when holding a write lock on rpzs->search_lock.
 */
static void
fix_triggers(dns_rpz_zones_t *rpzs, dns_rpz_num_t rpz_num) {
    dns_rpz_num_t n;
    dns_rpz_triggers_t old_totals;
    dns_rpz_zbits_t zbit;
    char namebuf[DNS_NAME_FORMATSIZE];

    /*
     * rpzs->total_triggers is only used to log a message below.
     */

    memmove(&old_totals, &rpzs->total_triggers, sizeof(old_totals));
    memset(&rpzs->total_triggers, 0, sizeof(rpzs->total_triggers));

#define SET_TRIG(n, zbit, type)                     \
    if (rpzs->triggers[n].type == 0U) {             \
        rpzs->have.type &= ~zbit;               \
    } else {                            \
        rpzs->total_triggers.type += rpzs->triggers[n].type;    \
        rpzs->have.type |= zbit;                \
    }

    for (n = 0; n < rpzs->p.num_zones; ++n) {
        zbit = DNS_RPZ_ZBIT(n);
        SET_TRIG(n, zbit, client_ipv4);
        SET_TRIG(n, zbit, client_ipv6);
        SET_TRIG(n, zbit, qname);
        SET_TRIG(n, zbit, ipv4);
        SET_TRIG(n, zbit, ipv6);
        SET_TRIG(n, zbit, nsdname);
        SET_TRIG(n, zbit, nsipv4);
        SET_TRIG(n, zbit, nsipv6);
    }

#undef SET_TRIG

    fix_qname_skip_recurse(rpzs);

    dns_name_format(&rpzs->zones[rpz_num]->origin,
            namebuf, sizeof(namebuf));
    isc_log_write(dns_lctx, DNS_LOGCATEGORY_RPZ,
              DNS_LOGMODULE_RBTDB, DNS_RPZ_INFO_LEVEL,
              "(re)loading policy zone '%s' changed from"
              " %lu to %lu qname, %lu to %lu nsdname,"
              " %lu to %lu IP, %lu to %lu NSIP entries",
              namebuf,
              (unsigned long) old_totals.qname,
              (unsigned long) rpzs->total_triggers.qname,
              (unsigned long) old_totals.nsdname,
              (unsigned long) rpzs->total_triggers.nsdname,
              (unsigned long) old_totals.ipv4 + old_totals.ipv6,
              (unsigned long) (rpzs->total_triggers.ipv4 +
                       rpzs->total_triggers.ipv6),
              (unsigned long) old_totals.nsipv4 + old_totals.nsipv6,
              (unsigned long) (rpzs->total_triggers.nsipv4 +
                       rpzs->total_triggers.nsipv6));
}

/*
 * Finish loading one zone. This function is called during a commit when
 * a RPZ zone loading is complete.  The RBTDB write tree lock must be
 * held.
 *
 * Here, rpzs is a pointer to the view's common rpzs
 * structure. *load_rpzsp is a rpzs structure that is local to the
 * RBTDB, which is used during a single zone's load.
 *
 * During the zone load, i.e., between dns_rpz_beginload() and
 * dns_rpz_ready(), only the zone that is being loaded updates
 * *load_rpzsp. These updates in the summary databases inside load_rpzsp
 * are made only for the rpz_num (and corresponding bit) of that
 * zone. Nothing else reads or writes *load_rpzsp. The view's common
 * rpzs is used during this time for queries.
 *
 * When zone loading is complete and we arrive here, the parts of the
 * summary databases (CIDR and nsdname+qname RBT trees) from the view's
 * common rpzs struct have to be merged into the summary databases of
 * *load_rpzsp, as the summary databases of the view's common rpzs
 * struct may have changed during the time the zone was being loaded.
 *
 * The function below carries out the merge. During the merge, it holds
 * the maint_lock of the view's common rpzs struct so that it is not
 * updated while the merging is taking place.
 *
 * After the merging is carried out, *load_rpzsp contains the most
 * current state of the rpzs structure, i.e., the summary trees contain
 * data for the new zone that was just loaded, as well as all other
 * zones.
 *
 * Pointers to the summary databases of *load_rpzsp (CIDR and
 * nsdname+qname RBT trees) are then swapped into the view's common rpz
 * struct, so that the query path can continue using it. During the
 * swap, the search_lock of the view's common rpz struct is acquired so
 * that queries are paused while this swap occurs.
 *
 * The trigger counts for the new zone are also copied into the view's
 * common rpz struct, and some other summary counts and masks are
 * updated.
 */
isc_result_t
dns_rpz_ready(dns_rpz_zones_t *rpzs,
          dns_rpz_zones_t **load_rpzsp, dns_rpz_num_t rpz_num)
{
    dns_rpz_zones_t *load_rpzs;
    const dns_rpz_cidr_node_t *cnode, *next_cnode, *parent_cnode;
    dns_rpz_cidr_node_t *found;
    dns_rpz_zbits_t new_bit;
    dns_rpz_addr_zbits_t new_ip;
    dns_rbt_t *rbt;
    dns_rbtnodechain_t chain;
    dns_rbtnode_t *nmnode;
    dns_rpz_nm_data_t *nm_data, new_data;
    dns_fixedname_t labelf, originf, namef;
    dns_name_t *label, *origin, *name;
    isc_result_t result;

    INSIST(rpzs != NULL);
    LOCK(&rpzs->maint_lock);
    load_rpzs = *load_rpzsp;
    INSIST(load_rpzs != NULL);

    if (load_rpzs == rpzs) {
        /*
         * This is a successful initial zone loading, perhaps
         * for a new instance of a view.
         */
        RWLOCK(&rpzs->search_lock, isc_rwlocktype_write);
        fix_triggers(rpzs, rpz_num);
        RWUNLOCK(&rpzs->search_lock, isc_rwlocktype_write);
        UNLOCK(&rpzs->maint_lock);
        dns_rpz_detach_rpzs(load_rpzsp);
        return (ISC_R_SUCCESS);
    }

    LOCK(&load_rpzs->maint_lock);
    RWLOCK(&load_rpzs->search_lock, isc_rwlocktype_write);

    /*
     * Unless there is only one policy zone, copy the other policy zones
     * from the old policy structure to the new summary databases.
     */
    if (rpzs->p.num_zones > 1) {
        new_bit = ~DNS_RPZ_ZBIT(rpz_num);

        /*
         * Copy to the radix tree.
         */
        for (cnode = rpzs->cidr; cnode != NULL; cnode = next_cnode) {
            new_ip.ip = cnode->set.ip & new_bit;
            new_ip.client_ip = cnode->set.client_ip & new_bit;
            new_ip.nsip = cnode->set.nsip & new_bit;
            if (new_ip.client_ip != 0 ||
                new_ip.ip != 0 ||
                new_ip.nsip != 0) {
                result = search(load_rpzs,
                        &cnode->ip, cnode->prefix,
                        &new_ip, ISC_TRUE, &found);
                if (result == ISC_R_NOMEMORY)
                    goto unlock_and_detach;
                INSIST(result == ISC_R_SUCCESS);
            }
            /*
             * Do down and to the left as far as possible.
             */
            next_cnode = cnode->child[0];
            if (next_cnode != NULL)
                continue;
            /*
             * Go up until we find a branch to the right where
             * we previously took the branch to the left.
             */
            for (;;) {
                parent_cnode = cnode->parent;
                if (parent_cnode == NULL)
                    break;
                if (parent_cnode->child[0] == cnode) {
                    next_cnode = parent_cnode->child[1];
                    if (next_cnode != NULL)
                        break;
                }
                cnode = parent_cnode;
            }
        }

        /*
         * Copy to the summary RBT.
         */
        dns_fixedname_init(&namef);
        name = dns_fixedname_name(&namef);
        dns_fixedname_init(&labelf);
        label = dns_fixedname_name(&labelf);
        dns_fixedname_init(&originf);
        origin = dns_fixedname_name(&originf);
        dns_rbtnodechain_init(&chain, NULL);
        result = dns_rbtnodechain_first(&chain, rpzs->rbt, NULL, NULL);
        while (result == DNS_R_NEWORIGIN || result == ISC_R_SUCCESS) {
            result = dns_rbtnodechain_current(&chain, label, origin,
                            &nmnode);
            INSIST(result == ISC_R_SUCCESS);
            nm_data = nmnode->data;
            if (nm_data != NULL) {
                new_data.set.qname = (nm_data->set.qname &
                              new_bit);
                new_data.set.ns = nm_data->set.ns & new_bit;
                new_data.wild.qname = (nm_data->wild.qname &
                               new_bit);
                new_data.wild.ns = nm_data->wild.ns & new_bit;
                if (new_data.set.qname != 0 ||
                    new_data.set.ns != 0 ||
                    new_data.wild.qname != 0 ||
                    new_data.wild.ns != 0) {
                    result = dns_name_concatenate(label,
                            origin, name, NULL);
                    INSIST(result == ISC_R_SUCCESS);
                    result = add_nm(load_rpzs, name,
                            &new_data);
                    if (result != ISC_R_SUCCESS)
                        goto unlock_and_detach;
                }
            }
            result = dns_rbtnodechain_next(&chain, NULL, NULL);
        }
        if (result != ISC_R_NOMORE && result != ISC_R_NOTFOUND) {
            isc_log_write(dns_lctx, DNS_LOGCATEGORY_RPZ,
                      DNS_LOGMODULE_RBTDB, DNS_RPZ_ERROR_LEVEL,
                      "dns_rpz_ready(): unexpected %s",
                      isc_result_totext(result));
            goto unlock_and_detach;
        }
    }

    /*
     * Exchange the summary databases.
     */
    RWLOCK(&rpzs->search_lock, isc_rwlocktype_write);

    rpzs->triggers[rpz_num] = load_rpzs->triggers[rpz_num];
    fix_triggers(rpzs, rpz_num);

    found = rpzs->cidr;
    rpzs->cidr = load_rpzs->cidr;
    load_rpzs->cidr = found;

    rbt = rpzs->rbt;
    rpzs->rbt = load_rpzs->rbt;
    load_rpzs->rbt = rbt;

    RWUNLOCK(&rpzs->search_lock, isc_rwlocktype_write);

    result = ISC_R_SUCCESS;

 unlock_and_detach:
    UNLOCK(&rpzs->maint_lock);
    RWUNLOCK(&load_rpzs->search_lock, isc_rwlocktype_write);
    UNLOCK(&load_rpzs->maint_lock);
    dns_rpz_detach_rpzs(load_rpzsp);
    return (result);
}

/*
 * Add an IP address to the radix tree or a name to the summary database.
 */
isc_result_t
dns_rpz_add(dns_rpz_zones_t *rpzs, dns_rpz_num_t rpz_num, dns_name_t *src_name)
{
    dns_rpz_zone_t *rpz;
    dns_rpz_type_t rpz_type;
    isc_result_t result = ISC_R_FAILURE;

    REQUIRE(rpzs != NULL && rpz_num < rpzs->p.num_zones);
    rpz = rpzs->zones[rpz_num];
    REQUIRE(rpz != NULL);

    rpz_type = type_from_name(rpz, src_name);

    LOCK(&rpzs->maint_lock);
    RWLOCK(&rpzs->search_lock, isc_rwlocktype_write);

    switch (rpz_type) {
    case DNS_RPZ_TYPE_QNAME:
    case DNS_RPZ_TYPE_NSDNAME:
        result = add_name(rpzs, rpz_num, rpz_type, src_name);
        break;
    case DNS_RPZ_TYPE_CLIENT_IP:
    case DNS_RPZ_TYPE_IP:
    case DNS_RPZ_TYPE_NSIP:
        result = add_cidr(rpzs, rpz_num, rpz_type, src_name);
        break;
    case DNS_RPZ_TYPE_BAD:
        break;
    }

    RWUNLOCK(&rpzs->search_lock, isc_rwlocktype_write);
    UNLOCK(&rpzs->maint_lock);
    return (result);
}

/*
 * Remove an IP address from the radix tree.
 */
static void
del_cidr(dns_rpz_zones_t *rpzs, dns_rpz_num_t rpz_num,
     dns_rpz_type_t rpz_type, dns_name_t *src_name)
{
    isc_result_t result;
    dns_rpz_cidr_key_t tgt_ip;
    dns_rpz_prefix_t tgt_prefix;
    dns_rpz_addr_zbits_t tgt_set;
    dns_rpz_cidr_node_t *tgt, *parent, *child;

    /*
     * Do not worry about invalid rpz IP address names.  If we
     * are here, then something relevant was added and so was
     * valid.  Invalid names here are usually internal RBTDB nodes.
     */
    result = name2ipkey(DNS_RPZ_DEBUG_QUIET, rpzs, rpz_num, rpz_type,
                src_name, &tgt_ip, &tgt_prefix, &tgt_set);
    if (result != ISC_R_SUCCESS)
        return;

    result = search(rpzs, &tgt_ip, tgt_prefix, &tgt_set, ISC_FALSE, &tgt);
    if (result != ISC_R_SUCCESS) {
        INSIST(result == ISC_R_NOTFOUND ||
               result == DNS_R_PARTIALMATCH);
        /*
         * Do not worry about missing summary RBT nodes that probably
         * correspond to RBTDB nodes that were implicit RBT nodes
         * that were later added for (often empty) wildcards
         * and then to the RBTDB deferred cleanup list.
         */
        return;
    }

    /*
     * Mark the node and its parents to reflect the deleted IP address.
     * Do not count bits that are already clear for internal RBTDB nodes.
     */
    tgt_set.client_ip &= tgt->set.client_ip;
    tgt_set.ip &= tgt->set.ip;
    tgt_set.nsip &= tgt->set.nsip;
    tgt->set.client_ip &= ~tgt_set.client_ip;
    tgt->set.ip &= ~tgt_set.ip;
    tgt->set.nsip &= ~tgt_set.nsip;
    set_sum_pair(tgt);

    adj_trigger_cnt(rpzs, rpz_num, rpz_type, &tgt_ip, tgt_prefix, ISC_FALSE);

    /*
     * We might need to delete 2 nodes.
     */
    do {
        /*
         * The node is now useless if it has no data of its own
         * and 0 or 1 children.  We are finished if it is not useless.
         */
        if ((child = tgt->child[0]) != NULL) {
            if (tgt->child[1] != NULL)
                break;
        } else {
            child = tgt->child[1];
        }
        if (tgt->set.client_ip != 0 ||
            tgt->set.ip != 0 ||
            tgt->set.nsip != 0)
            break;

        /*
         * Replace the pointer to this node in the parent with
         * the remaining child or NULL.
         */
        parent = tgt->parent;
        if (parent == NULL) {
            rpzs->cidr = child;
        } else {
            parent->child[parent->child[1] == tgt] = child;
        }
        /*
         * If the child exists fix up its parent pointer.
         */
        if (child != NULL)
            child->parent = parent;
        isc_mem_put(rpzs->mctx, tgt, sizeof(*tgt));

        tgt = parent;
    } while (tgt != NULL);
}

static void
del_name(dns_rpz_zones_t *rpzs, dns_rpz_num_t rpz_num,
     dns_rpz_type_t rpz_type, dns_name_t *src_name)
{
    char namebuf[DNS_NAME_FORMATSIZE];
    dns_fixedname_t trig_namef;
    dns_name_t *trig_name;
    dns_rbtnode_t *nmnode;
    dns_rpz_nm_data_t *nm_data, del_data;
    isc_result_t result;

    /*
     * No need for a summary database of names with only 1 policy zone.
     */
    if (rpzs->p.num_zones <= 1) {
        adj_trigger_cnt(rpzs, rpz_num, rpz_type, NULL, 0, ISC_FALSE);
        return;
    }

    dns_fixedname_init(&trig_namef);
    trig_name = dns_fixedname_name(&trig_namef);
    name2data(rpzs, rpz_num, rpz_type, src_name, trig_name, &del_data);

    nmnode = NULL;
    result = dns_rbt_findnode(rpzs->rbt, trig_name, NULL, &nmnode, NULL, 0,
                  NULL, NULL);
    if (result != ISC_R_SUCCESS) {
        /*
         * Do not worry about missing summary RBT nodes that probably
         * correspond to RBTDB nodes that were implicit RBT nodes
         * that were later added for (often empty) wildcards
         * and then to the RBTDB deferred cleanup list.
         */
        if (result == ISC_R_NOTFOUND ||
            result == DNS_R_PARTIALMATCH)
            return;
        dns_name_format(src_name, namebuf, sizeof(namebuf));
        isc_log_write(dns_lctx, DNS_LOGCATEGORY_RPZ,
                  DNS_LOGMODULE_RBTDB, DNS_RPZ_ERROR_LEVEL,
                  "rpz del_name(%s) node search failed: %s",
                  namebuf, isc_result_totext(result));
        return;
    }

    nm_data = nmnode->data;
    INSIST(nm_data != NULL);

    /*
     * Do not count bits that next existed for RBT nodes that would we
     * would not have found in a summary for a single RBTDB tree.
     */
    del_data.set.qname &= nm_data->set.qname;
    del_data.set.ns &= nm_data->set.ns;
    del_data.wild.qname &= nm_data->wild.qname;
    del_data.wild.ns &= nm_data->wild.ns;

    nm_data->set.qname &= ~del_data.set.qname;
    nm_data->set.ns &= ~del_data.set.ns;
    nm_data->wild.qname &= ~del_data.wild.qname;
    nm_data->wild.ns &= ~del_data.wild.ns;

    if (nm_data->set.qname == 0 && nm_data->set.ns == 0 &&
        nm_data->wild.qname == 0 && nm_data->wild.ns == 0) {
        result = dns_rbt_deletenode(rpzs->rbt, nmnode, ISC_FALSE);
        if (result != ISC_R_SUCCESS) {
            /*
             * bin/tests/system/rpz/tests.sh looks for "rpz.*failed".
             */
            dns_name_format(src_name, namebuf, sizeof(namebuf));
            isc_log_write(dns_lctx, DNS_LOGCATEGORY_RPZ,
                      DNS_LOGMODULE_RBTDB, DNS_RPZ_ERROR_LEVEL,
                      "rpz del_name(%s) node delete failed: %s",
                      namebuf, isc_result_totext(result));
        }
    }

    adj_trigger_cnt(rpzs, rpz_num, rpz_type, NULL, 0, ISC_FALSE);
}

/*
 * Remove an IP address from the radix tree or a name from the summary database.
 */
void
dns_rpz_delete(dns_rpz_zones_t *rpzs, dns_rpz_num_t rpz_num,
           dns_name_t *src_name) {
    dns_rpz_zone_t *rpz;
    dns_rpz_type_t rpz_type;

    REQUIRE(rpzs != NULL && rpz_num < rpzs->p.num_zones);
    rpz = rpzs->zones[rpz_num];
    REQUIRE(rpz != NULL);

    rpz_type = type_from_name(rpz, src_name);

    LOCK(&rpzs->maint_lock);
    RWLOCK(&rpzs->search_lock, isc_rwlocktype_write);

    switch (rpz_type) {
    case DNS_RPZ_TYPE_QNAME:
    case DNS_RPZ_TYPE_NSDNAME:
        del_name(rpzs, rpz_num, rpz_type, src_name);
        break;
    case DNS_RPZ_TYPE_CLIENT_IP:
    case DNS_RPZ_TYPE_IP:
    case DNS_RPZ_TYPE_NSIP:
        del_cidr(rpzs, rpz_num, rpz_type, src_name);
        break;
    case DNS_RPZ_TYPE_BAD:
        break;
    }

    RWUNLOCK(&rpzs->search_lock, isc_rwlocktype_write);
    UNLOCK(&rpzs->maint_lock);
}

/*
 * Search the summary radix tree to get a relative owner name in a
 * policy zone relevant to a triggering IP address.
 *  rpz_type and zbits limit the search for IP address netaddr
 *  return the policy zone's number or DNS_RPZ_INVALID_NUM
 *  ip_name is the relative owner name found and
 *  *prefixp is its prefix length.
 */
dns_rpz_num_t
dns_rpz_find_ip(dns_rpz_zones_t *rpzs, dns_rpz_type_t rpz_type,
        dns_rpz_zbits_t zbits, const isc_netaddr_t *netaddr,
        dns_name_t *ip_name, dns_rpz_prefix_t *prefixp)
{
    dns_rpz_cidr_key_t tgt_ip;
    dns_rpz_addr_zbits_t tgt_set;
    dns_rpz_cidr_node_t *found;
    isc_result_t result;
    dns_rpz_num_t rpz_num;
    dns_rpz_have_t have;
    int i;

    LOCK(&rpzs->maint_lock);
    have = rpzs->have;
    UNLOCK(&rpzs->maint_lock);

    /*
     * Convert IP address to CIDR tree key.
     */
    if (netaddr->family == AF_INET) {
        tgt_ip.w[0] = 0;
        tgt_ip.w[1] = 0;
        tgt_ip.w[2] = ADDR_V4MAPPED;
        tgt_ip.w[3] = ntohl(netaddr->type.in.s_addr);
        switch (rpz_type) {
        case DNS_RPZ_TYPE_CLIENT_IP:
            zbits &= have.client_ipv4;
            break;
        case DNS_RPZ_TYPE_IP:
            zbits &= have.ipv4;
            break;
        case DNS_RPZ_TYPE_NSIP:
            zbits &= have.nsipv4;
            break;
        default:
            INSIST(0);
            break;
        }
    } else if (netaddr->family == AF_INET6) {
        dns_rpz_cidr_key_t src_ip6;

        /*
         * Given the int aligned struct in_addr member of netaddr->type
         * one could cast netaddr->type.in6 to dns_rpz_cidr_key_t *,
         * but some people object.
         */
        memmove(src_ip6.w, &netaddr->type.in6, sizeof(src_ip6.w));
        for (i = 0; i < 4; i++) {
            tgt_ip.w[i] = ntohl(src_ip6.w[i]);
        }
        switch (rpz_type) {
        case DNS_RPZ_TYPE_CLIENT_IP:
            zbits &= have.client_ipv6;
            break;
        case DNS_RPZ_TYPE_IP:
            zbits &= have.ipv6;
            break;
        case DNS_RPZ_TYPE_NSIP:
            zbits &= have.nsipv6;
            break;
        default:
            INSIST(0);
            break;
        }
    } else {
        return (DNS_RPZ_INVALID_NUM);
    }

    if (zbits == 0)
        return (DNS_RPZ_INVALID_NUM);
    make_addr_set(&tgt_set, zbits, rpz_type);

    RWLOCK(&rpzs->search_lock, isc_rwlocktype_read);
    result = search(rpzs, &tgt_ip, 128, &tgt_set, ISC_FALSE, &found);
    if (result == ISC_R_NOTFOUND) {
        /*
         * There are no eligible zones for this IP address.
         */
        RWUNLOCK(&rpzs->search_lock, isc_rwlocktype_read);
        return (DNS_RPZ_INVALID_NUM);
    }

    /*
     * Construct the trigger name for the longest matching trigger
     * in the first eligible zone with a match.
     */
    *prefixp = found->prefix;
    switch (rpz_type) {
    case DNS_RPZ_TYPE_CLIENT_IP:
        rpz_num = zbit_to_num(found->set.client_ip & tgt_set.client_ip);
        break;
    case DNS_RPZ_TYPE_IP:
        rpz_num = zbit_to_num(found->set.ip & tgt_set.ip);
        break;
    case DNS_RPZ_TYPE_NSIP:
        rpz_num = zbit_to_num(found->set.nsip & tgt_set.nsip);
        break;
    default:
        INSIST(0);
        break;
    }
    result = ip2name(&found->ip, found->prefix, dns_rootname, ip_name);
    RWUNLOCK(&rpzs->search_lock, isc_rwlocktype_read);
    if (result != ISC_R_SUCCESS) {
        /*
         * bin/tests/system/rpz/tests.sh looks for "rpz.*failed".
         */
        isc_log_write(dns_lctx, DNS_LOGCATEGORY_RPZ,
                  DNS_LOGMODULE_RBTDB, DNS_RPZ_ERROR_LEVEL,
                  "rpz ip2name() failed: %s",
                  isc_result_totext(result));
        return (DNS_RPZ_INVALID_NUM);
    }
    return (rpz_num);
}

/*
 * Search the summary radix tree for policy zones with triggers matching
 * a name.
 */
dns_rpz_zbits_t
dns_rpz_find_name(dns_rpz_zones_t *rpzs, dns_rpz_type_t rpz_type,
          dns_rpz_zbits_t zbits, dns_name_t *trig_name)
{
    char namebuf[DNS_NAME_FORMATSIZE];
    dns_rbtnode_t *nmnode;
    const dns_rpz_nm_data_t *nm_data;
    dns_rpz_zbits_t found_zbits;
    isc_result_t result;

    if (zbits == 0)
        return (0);

    found_zbits = 0;

    RWLOCK(&rpzs->search_lock, isc_rwlocktype_read);

    nmnode = NULL;
    result = dns_rbt_findnode(rpzs->rbt, trig_name, NULL, &nmnode, NULL,
                  DNS_RBTFIND_EMPTYDATA, NULL, NULL);
    switch (result) {
    case ISC_R_SUCCESS:
        nm_data = nmnode->data;
        if (nm_data != NULL) {
            if (rpz_type == DNS_RPZ_TYPE_QNAME)
                found_zbits = nm_data->set.qname;
            else
                found_zbits = nm_data->set.ns;
        }
        nmnode = nmnode->parent;
        /* fall thru */
    case DNS_R_PARTIALMATCH:
        while (nmnode != NULL) {
            nm_data = nmnode->data;
            if (nm_data != NULL) {
                if (rpz_type == DNS_RPZ_TYPE_QNAME)
                    found_zbits |= nm_data->wild.qname;
                else
                    found_zbits |= nm_data->wild.ns;
            }
            nmnode = nmnode->parent;
        }
        break;

    case ISC_R_NOTFOUND:
        break;

    default:
        /*
         * bin/tests/system/rpz/tests.sh looks for "rpz.*failed".
         */
        dns_name_format(trig_name, namebuf, sizeof(namebuf));
        isc_log_write(dns_lctx, DNS_LOGCATEGORY_RPZ,
                  DNS_LOGMODULE_RBTDB, DNS_RPZ_ERROR_LEVEL,
                  "dns_rpz_find_name(%s) failed: %s",
                  namebuf, isc_result_totext(result));
        break;
    }

    RWUNLOCK(&rpzs->search_lock, isc_rwlocktype_read);
    return (zbits & found_zbits);
}

/*
 * Translate CNAME rdata to a QNAME response policy action.
 */
dns_rpz_policy_t
dns_rpz_decode_cname(dns_rpz_zone_t *rpz, dns_rdataset_t *rdataset,
             dns_name_t *selfname)
{
    dns_rdata_t rdata = DNS_RDATA_INIT;
    dns_rdata_cname_t cname;
    isc_result_t result;

    result = dns_rdataset_first(rdataset);
    INSIST(result == ISC_R_SUCCESS);
    dns_rdataset_current(rdataset, &rdata);
    result = dns_rdata_tostruct(&rdata, &cname, NULL);
    INSIST(result == ISC_R_SUCCESS);
    dns_rdata_reset(&rdata);

    /*
     * CNAME . means NXDOMAIN
     */
    if (dns_name_equal(&cname.cname, dns_rootname))
        return (DNS_RPZ_POLICY_NXDOMAIN);

    if (dns_name_iswildcard(&cname.cname)) {
        /*
         * CNAME *. means NODATA
         */
        if (dns_name_countlabels(&cname.cname) == 2)
            return (DNS_RPZ_POLICY_NODATA);

        /*
         * A qname of www.evil.com and a policy of
         *  *.evil.com    CNAME   *.garden.net
         * gives a result of
         *  evil.com    CNAME   evil.com.garden.net
         */
        if (dns_name_countlabels(&cname.cname) > 2)
            return (DNS_RPZ_POLICY_WILDCNAME);
    }

    /*
     * CNAME rpz-tcp-only. means "send truncated UDP responses."
     */
    if (dns_name_equal(&cname.cname, &rpz->tcp_only))
        return (DNS_RPZ_POLICY_TCP_ONLY);

    /*
     * CNAME rpz-drop. means "do not respond."
     */
    if (dns_name_equal(&cname.cname, &rpz->drop))
        return (DNS_RPZ_POLICY_DROP);

    /*
     * CNAME rpz-passthru. means "do not rewrite."
     */
    if (dns_name_equal(&cname.cname, &rpz->passthru))
        return (DNS_RPZ_POLICY_PASSTHRU);

    /*
     * 128.1.0.127.rpz-ip CNAME  128.1.0.0.127. is obsolete PASSTHRU
     */
    if (selfname != NULL && dns_name_equal(&cname.cname, selfname))
        return (DNS_RPZ_POLICY_PASSTHRU);

    /*
     * Any other rdata gives a response consisting of the rdata.
     */
    return (DNS_RPZ_POLICY_RECORD);
}