lib/dns/rdatalist.c

/*
 * Copyright (C) 1999-2001, 2003-2005, 2007, 2008, 2010-2012, 2014-2016  Internet Systems Consortium, Inc. ("ISC")
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 */

/* $Id$ */

/*! \file */

#include <config.h>

#include <stddef.h>
#include <string.h>

#include <isc/util.h>

#include <dns/name.h>
#include <dns/nsec3.h>
#include <dns/rdata.h>
#include <dns/rdatalist.h>
#include <dns/rdataset.h>

#include "rdatalist_p.h"

static dns_rdatasetmethods_t methods = {
    isc__rdatalist_disassociate,
    isc__rdatalist_first,
    isc__rdatalist_next,
    isc__rdatalist_current,
    isc__rdatalist_clone,
    isc__rdatalist_count,
    isc__rdatalist_addnoqname,
    isc__rdatalist_getnoqname,
    isc__rdatalist_addclosest,
    isc__rdatalist_getclosest,
    NULL,
    NULL,
    NULL,
    NULL,
    NULL,
    NULL,
    isc__rdatalist_setownercase,
    isc__rdatalist_getownercase
};

void
dns_rdatalist_init(dns_rdatalist_t *rdatalist) {

    REQUIRE(rdatalist != NULL);

    /*
     * Initialize rdatalist.
     */

    rdatalist->rdclass = 0;
    rdatalist->type = 0;
    rdatalist->covers = 0;
    rdatalist->ttl = 0;
    ISC_LIST_INIT(rdatalist->rdata);
    ISC_LINK_INIT(rdatalist, link);
    memset(rdatalist->upper, 0xeb, sizeof(rdatalist->upper));
    /*
     * Clear upper set bit.
     */
    rdatalist->upper[0] &= ~0x01;
}

isc_result_t
dns_rdatalist_tordataset(dns_rdatalist_t *rdatalist,
             dns_rdataset_t *rdataset)
{
    /*
     * Make 'rdataset' refer to the rdata in 'rdatalist'.
     */

    REQUIRE(rdatalist != NULL);
    REQUIRE(DNS_RDATASET_VALID(rdataset));
    REQUIRE(! dns_rdataset_isassociated(rdataset));

    /* Check if dns_rdatalist_init has was called. */
    REQUIRE(rdatalist->upper[0] == 0xea);

    rdataset->methods = &methods;
    rdataset->rdclass = rdatalist->rdclass;
    rdataset->type = rdatalist->type;
    rdataset->covers = rdatalist->covers;
    rdataset->ttl = rdatalist->ttl;
    rdataset->trust = 0;
    rdataset->private1 = rdatalist;
    rdataset->private2 = NULL;
    rdataset->private3 = NULL;
    rdataset->privateuint4 = 0;
    rdataset->private5 = NULL;

    return (ISC_R_SUCCESS);
}

isc_result_t
dns_rdatalist_fromrdataset(dns_rdataset_t *rdataset,
               dns_rdatalist_t **rdatalist)
{
    REQUIRE(rdatalist != NULL && rdataset != NULL);
    *rdatalist = rdataset->private1;

    return (ISC_R_SUCCESS);
}

void
isc__rdatalist_disassociate(dns_rdataset_t *rdataset) {
    UNUSED(rdataset);
}

isc_result_t
isc__rdatalist_first(dns_rdataset_t *rdataset) {
    dns_rdatalist_t *rdatalist;

    rdatalist = rdataset->private1;
    rdataset->private2 = ISC_LIST_HEAD(rdatalist->rdata);

    if (rdataset->private2 == NULL)
        return (ISC_R_NOMORE);

    return (ISC_R_SUCCESS);
}

isc_result_t
isc__rdatalist_next(dns_rdataset_t *rdataset) {
    dns_rdata_t *rdata;

    REQUIRE(rdataset != NULL);

    rdata = rdataset->private2;
    if (rdata == NULL)
        return (ISC_R_NOMORE);

    rdataset->private2 = ISC_LIST_NEXT(rdata, link);

    if (rdataset->private2 == NULL)
        return (ISC_R_NOMORE);

    return (ISC_R_SUCCESS);
}

void
isc__rdatalist_current(dns_rdataset_t *rdataset, dns_rdata_t *rdata) {
    dns_rdata_t *list_rdata;

    REQUIRE(rdataset != NULL);

    list_rdata = rdataset->private2;
    INSIST(list_rdata != NULL);

    dns_rdata_clone(list_rdata, rdata);
}

void
isc__rdatalist_clone(dns_rdataset_t *source, dns_rdataset_t *target) {

    REQUIRE(source != NULL);
    REQUIRE(target != NULL);

    *target = *source;

    /*
     * Reset iterator state.
     */
    target->private2 = NULL;
}

unsigned int
isc__rdatalist_count(dns_rdataset_t *rdataset) {
    dns_rdatalist_t *rdatalist;
    dns_rdata_t *rdata;
    unsigned int count;

    REQUIRE(rdataset != NULL);

    rdatalist = rdataset->private1;

    count = 0;
    for (rdata = ISC_LIST_HEAD(rdatalist->rdata);
         rdata != NULL;
         rdata = ISC_LIST_NEXT(rdata, link))
        count++;

    return (count);
}

isc_result_t
isc__rdatalist_addnoqname(dns_rdataset_t *rdataset, dns_name_t *name) {
    dns_rdataset_t *neg = NULL;
    dns_rdataset_t *negsig = NULL;
    dns_rdataset_t *rdset;
    dns_ttl_t ttl;

    REQUIRE(rdataset != NULL);

    for (rdset = ISC_LIST_HEAD(name->list);
         rdset != NULL;
         rdset = ISC_LIST_NEXT(rdset, link))
    {
        if (rdset->rdclass != rdataset->rdclass)
            continue;
        if (rdset->type == dns_rdatatype_nsec ||
            rdset->type == dns_rdatatype_nsec3)
            neg = rdset;
    }
    if (neg == NULL)
        return (ISC_R_NOTFOUND);

    for (rdset = ISC_LIST_HEAD(name->list);
         rdset != NULL;
         rdset = ISC_LIST_NEXT(rdset, link))
    {
        if (rdset->type == dns_rdatatype_rrsig &&
            rdset->covers == neg->type)
            negsig = rdset;
    }

    if (negsig == NULL)
        return (ISC_R_NOTFOUND);
    /*
     * Minimise ttl.
     */
    ttl = rdataset->ttl;
    if (neg->ttl < ttl)
        ttl = neg->ttl;
    if (negsig->ttl < ttl)
        ttl = negsig->ttl;
    rdataset->ttl = neg->ttl = negsig->ttl = ttl;
    rdataset->attributes |= DNS_RDATASETATTR_NOQNAME;
    rdataset->private6 = name;
    return (ISC_R_SUCCESS);
}

isc_result_t
isc__rdatalist_getnoqname(dns_rdataset_t *rdataset, dns_name_t *name,
              dns_rdataset_t *neg, dns_rdataset_t *negsig)
{
    dns_rdataclass_t rdclass = rdataset->rdclass;
    dns_rdataset_t *tneg = NULL;
    dns_rdataset_t *tnegsig = NULL;
    dns_name_t *noqname = rdataset->private6;

    REQUIRE(rdataset != NULL);
    REQUIRE((rdataset->attributes & DNS_RDATASETATTR_NOQNAME) != 0);

    (void)dns_name_dynamic(noqname);    /* Sanity Check. */

    for (rdataset = ISC_LIST_HEAD(noqname->list);
         rdataset != NULL;
         rdataset = ISC_LIST_NEXT(rdataset, link))
    {
        if (rdataset->rdclass != rdclass)
            continue;
        if (rdataset->type == dns_rdatatype_nsec ||
            rdataset->type == dns_rdatatype_nsec3)
            tneg = rdataset;
    }
    if (tneg == NULL)
        return (ISC_R_NOTFOUND);

    for (rdataset = ISC_LIST_HEAD(noqname->list);
         rdataset != NULL;
         rdataset = ISC_LIST_NEXT(rdataset, link))
    {
        if (rdataset->type == dns_rdatatype_rrsig &&
            rdataset->covers == tneg->type)
            tnegsig = rdataset;
    }
    if (tnegsig == NULL)
        return (ISC_R_NOTFOUND);

    dns_name_clone(noqname, name);
    dns_rdataset_clone(tneg, neg);
    dns_rdataset_clone(tnegsig, negsig);
    return (ISC_R_SUCCESS);
}

isc_result_t
isc__rdatalist_addclosest(dns_rdataset_t *rdataset, dns_name_t *name) {
    dns_rdataset_t *neg = NULL;
    dns_rdataset_t *negsig = NULL;
    dns_rdataset_t *rdset;
    dns_ttl_t ttl;

    REQUIRE(rdataset != NULL);

    for (rdset = ISC_LIST_HEAD(name->list);
         rdset != NULL;
         rdset = ISC_LIST_NEXT(rdset, link))
    {
        if (rdset->rdclass != rdataset->rdclass)
            continue;
        if (rdset->type == dns_rdatatype_nsec ||
            rdset->type == dns_rdatatype_nsec3)
            neg = rdset;
    }
    if (neg == NULL)
        return (ISC_R_NOTFOUND);

    for (rdset = ISC_LIST_HEAD(name->list);
         rdset != NULL;
         rdset = ISC_LIST_NEXT(rdset, link))
    {
        if (rdset->type == dns_rdatatype_rrsig &&
            rdset->covers == neg->type)
            negsig = rdset;
    }

    if (negsig == NULL)
        return (ISC_R_NOTFOUND);
    /*
     * Minimise ttl.
     */
    ttl = rdataset->ttl;
    if (neg->ttl < ttl)
        ttl = neg->ttl;
    if (negsig->ttl < ttl)
        ttl = negsig->ttl;
    rdataset->ttl = neg->ttl = negsig->ttl = ttl;
    rdataset->attributes |= DNS_RDATASETATTR_CLOSEST;
    rdataset->private7 = name;
    return (ISC_R_SUCCESS);
}

isc_result_t
isc__rdatalist_getclosest(dns_rdataset_t *rdataset, dns_name_t *name,
              dns_rdataset_t *neg, dns_rdataset_t *negsig)
{
    dns_rdataclass_t rdclass = rdataset->rdclass;
    dns_rdataset_t *tneg = NULL;
    dns_rdataset_t *tnegsig = NULL;
    dns_name_t *closest = rdataset->private7;

    REQUIRE(rdataset != NULL);
    REQUIRE((rdataset->attributes & DNS_RDATASETATTR_CLOSEST) != 0);

    (void)dns_name_dynamic(closest);    /* Sanity Check. */

    for (rdataset = ISC_LIST_HEAD(closest->list);
         rdataset != NULL;
         rdataset = ISC_LIST_NEXT(rdataset, link))
    {
        if (rdataset->rdclass != rdclass)
            continue;
        if (rdataset->type == dns_rdatatype_nsec ||
            rdataset->type == dns_rdatatype_nsec3)
            tneg = rdataset;
    }
    if (tneg == NULL)
        return (ISC_R_NOTFOUND);

    for (rdataset = ISC_LIST_HEAD(closest->list);
         rdataset != NULL;
         rdataset = ISC_LIST_NEXT(rdataset, link))
    {
        if (rdataset->type == dns_rdatatype_rrsig &&
            rdataset->covers == tneg->type)
            tnegsig = rdataset;
    }
    if (tnegsig == NULL)
        return (ISC_R_NOTFOUND);

    dns_name_clone(closest, name);
    dns_rdataset_clone(tneg, neg);
    dns_rdataset_clone(tnegsig, negsig);
    return (ISC_R_SUCCESS);
}

void
isc__rdatalist_setownercase(dns_rdataset_t *rdataset, const dns_name_t *name) {
    dns_rdatalist_t *rdatalist;
    unsigned int i;

    /*
     * We do not need to worry about label lengths as they are all
     * less than or equal to 63.
     */
    rdatalist = rdataset->private1;
    memset(rdatalist->upper, 0, sizeof(rdatalist->upper));
    for (i = 1; i < name->length; i++)
        if (name->ndata[i] >= 0x41 && name->ndata[i] <= 0x5a)
            rdatalist->upper[i/8] |= 1 << (i%8);
    /*
     * Record that upper has been set.
     */
    rdatalist->upper[0] |= 0x01;
}

void
isc__rdatalist_getownercase(const dns_rdataset_t *rdataset, dns_name_t *name) {
    dns_rdatalist_t *rdatalist;
    unsigned int i;

    rdatalist = rdataset->private1;
    if ((rdatalist->upper[0] & 0x01) == 0)
        return;
    for (i = 0; i < name->length; i++) {
        /*
         * Set the case bit if it does not match the recorded bit.
         */
        if (name->ndata[i] >= 0x61 && name->ndata[i] <= 0x7a &&
            (rdatalist->upper[i/8] & (1 << (i%8))) != 0)
            name->ndata[i] &= ~0x20; /* clear the lower case bit */
        else if (name->ndata[i] >= 0x41 && name->ndata[i] <= 0x5a &&
            (rdatalist->upper[i/8] & (1 << (i%8))) == 0)
            name->ndata[i] |= 0x20; /* set the lower case bit */
    }
}