validator.c

非常好的dns解析软件

	}
	isc_event_free(&event);
	want_destroy = exit_check(val);
	UNLOCK(&val->lock);
	if (want_destroy)
		destroy(val);
}

/*%
 * Callback from when a DNSKEY RRset has been validated.
 *
 * Resumes the stalled validation process.
 */
static void
keyvalidated(isc_task_t *task, isc_event_t *event) {
	dns_validatorevent_t *devent;
	dns_validator_t *val;
	isc_boolean_t want_destroy;
	isc_result_t result;
	isc_result_t eresult;

	UNUSED(task);
	INSIST(event->ev_type == DNS_EVENT_VALIDATORDONE);

	devent = (dns_validatorevent_t *)event;
	val = devent->ev_arg;
	eresult = devent->result;

	isc_event_free(&event);
	dns_validator_destroy(&val->subvalidator);

	INSIST(val->event != NULL);

	validator_log(val, ISC_LOG_DEBUG(3), "in keyvalidated");
	LOCK(&val->lock);
	if (eresult == ISC_R_SUCCESS) {
		validator_log(val, ISC_LOG_DEBUG(3),
			      "keyset with trust %d", val->frdataset.trust);
		/*
		 * Only extract the dst key if the keyset is secure.
		 */
		if (val->frdataset.trust >= dns_trust_secure)
			(void) get_dst_key(val, val->siginfo, &val->frdataset);
		result = validate(val, ISC_TRUE);
		if (result != DNS_R_WAIT)
			validator_done(val, result);
	} else {
		validator_log(val, ISC_LOG_DEBUG(3),
			      "keyvalidated: got %s",
			      isc_result_totext(eresult));
		validator_done(val, eresult);
	}
	want_destroy = exit_check(val);
	UNLOCK(&val->lock);
	if (want_destroy)
		destroy(val);
}

/*%
 * Callback when the DS record has been validated.
 *
 * Resumes validation of the zone key or the unsecure zone proof.
 */
static void
dsvalidated(isc_task_t *task, isc_event_t *event) {
	dns_validatorevent_t *devent;
	dns_validator_t *val;
	isc_boolean_t want_destroy;
	isc_result_t result;
	isc_result_t eresult;

	UNUSED(task);
	INSIST(event->ev_type == DNS_EVENT_VALIDATORDONE);

	devent = (dns_validatorevent_t *)event;
	val = devent->ev_arg;
	eresult = devent->result;

	isc_event_free(&event);
	dns_validator_destroy(&val->subvalidator);

	INSIST(val->event != NULL);

	validator_log(val, ISC_LOG_DEBUG(3), "in dsvalidated");
	LOCK(&val->lock);
	if (eresult == ISC_R_SUCCESS) {
		validator_log(val, ISC_LOG_DEBUG(3),
			      "dsset with trust %d", val->frdataset.trust);
		if ((val->attributes & VALATTR_INSECURITY) != 0)
			result = proveunsecure(val, ISC_TRUE);
		else
			result = validatezonekey(val);
		if (result != DNS_R_WAIT)
			validator_done(val, result);
	} else {
		validator_log(val, ISC_LOG_DEBUG(3),
			      "dsvalidated: got %s",
			      isc_result_totext(eresult));
		validator_done(val, eresult);
	}
	want_destroy = exit_check(val);
	UNLOCK(&val->lock);
	if (want_destroy)
		destroy(val);
}

/*%
 * Return ISC_R_SUCCESS if we can determine that the name doesn't exist
 * or we can determine whether there is data or not at the name.
 * If the name does not exist return the wildcard name.
 *
 * Return ISC_R_IGNORE when the NSEC is not the appropriate one.
 */
static isc_result_t
nsecnoexistnodata(dns_validator_t *val, dns_name_t* name, dns_name_t *nsecname,
		  dns_rdataset_t *nsecset, isc_boolean_t *exists,
		  isc_boolean_t *data, dns_name_t *wild)
{
	int order;
	dns_rdata_t rdata = DNS_RDATA_INIT;
	isc_result_t result;
	dns_namereln_t relation;
	unsigned int olabels, nlabels, labels;
	dns_rdata_nsec_t nsec;
	isc_boolean_t atparent;
	isc_boolean_t ns;
	isc_boolean_t soa;

	REQUIRE(exists != NULL);
	REQUIRE(data != NULL);
	REQUIRE(nsecset != NULL &&
		nsecset->type == dns_rdatatype_nsec);

	result = dns_rdataset_first(nsecset);
	if (result != ISC_R_SUCCESS) {
		validator_log(val, ISC_LOG_DEBUG(3),
			"failure processing NSEC set");
		return (result);
	}
	dns_rdataset_current(nsecset, &rdata);

	validator_log(val, ISC_LOG_DEBUG(3), "looking for relevant nsec");
	relation = dns_name_fullcompare(name, nsecname, &order, &olabels);

	if (order < 0) {
		/*
		 * The name is not within the NSEC range.
		 */
		validator_log(val, ISC_LOG_DEBUG(3),
			      "NSEC does not cover name, before NSEC");
		return (ISC_R_IGNORE);
	}

	if (order == 0) {
		/*
		 * The names are the same.
		 */
		atparent = dns_rdatatype_atparent(val->event->type);
		ns = dns_nsec_typepresent(&rdata, dns_rdatatype_ns);
		soa = dns_nsec_typepresent(&rdata, dns_rdatatype_soa);
		if (ns && !soa) {
			if (!atparent) {
				/*
				 * This NSEC record is from somewhere higher in
				 * the DNS, and at the parent of a delegation.
				 * It can not be legitimately used here.
				 */
				validator_log(val, ISC_LOG_DEBUG(3),
					      "ignoring parent nsec");
				return (ISC_R_IGNORE);
			}
		} else if (atparent && ns && soa) {
			/*
			 * This NSEC record is from the child.
			 * It can not be legitimately used here.
			 */
			validator_log(val, ISC_LOG_DEBUG(3),
				      "ignoring child nsec");
			return (ISC_R_IGNORE);
		}
		if (val->event->type == dns_rdatatype_cname ||
		    val->event->type == dns_rdatatype_nxt ||
		    val->event->type == dns_rdatatype_nsec ||
		    val->event->type == dns_rdatatype_key ||
		    !dns_nsec_typepresent(&rdata, dns_rdatatype_cname)) {
			*exists = ISC_TRUE;
			*data = dns_nsec_typepresent(&rdata, val->event->type);
			validator_log(val, ISC_LOG_DEBUG(3),
				      "nsec proves name exists (owner) data=%d",
				      *data);
			return (ISC_R_SUCCESS);
		}
		validator_log(val, ISC_LOG_DEBUG(3), "NSEC proves CNAME exists");
		return (ISC_R_IGNORE);
	}

	if (relation == dns_namereln_subdomain &&
	    dns_nsec_typepresent(&rdata, dns_rdatatype_ns) &&
	    !dns_nsec_typepresent(&rdata, dns_rdatatype_soa))
	{
		/*
		 * This NSEC record is from somewhere higher in
		 * the DNS, and at the parent of a delegation.
		 * It can not be legitimately used here.
		 */
		validator_log(val, ISC_LOG_DEBUG(3), "ignoring parent nsec");
		return (ISC_R_IGNORE);
	}

	result = dns_rdata_tostruct(&rdata, &nsec, NULL);
	if (result != ISC_R_SUCCESS)
		return (result);
	relation = dns_name_fullcompare(&nsec.next, name, &order, &nlabels);
	if (order == 0) {
		dns_rdata_freestruct(&nsec);
		validator_log(val, ISC_LOG_DEBUG(3),
			      "ignoring nsec matches next name");
		return (ISC_R_IGNORE);
	}

	if (order < 0 && !dns_name_issubdomain(nsecname, &nsec.next)) {
		/*
		 * The name is not within the NSEC range.
		 */
		dns_rdata_freestruct(&nsec);
		validator_log(val, ISC_LOG_DEBUG(3),
			    "ignoring nsec because name is past end of range");
		return (ISC_R_IGNORE);
	}

	if (order > 0 && relation == dns_namereln_subdomain) {
		validator_log(val, ISC_LOG_DEBUG(3),
			      "nsec proves name exist (empty)");
		dns_rdata_freestruct(&nsec);
		*exists = ISC_TRUE;
		*data = ISC_FALSE;
		return (ISC_R_SUCCESS);
	}
	if (wild != NULL) {
		dns_name_t common;
		dns_name_init(&common, NULL);
		if (olabels > nlabels) {
			labels = dns_name_countlabels(nsecname);
			dns_name_getlabelsequence(nsecname, labels - olabels,
						  olabels, &common);
		} else {
			labels = dns_name_countlabels(&nsec.next);
			dns_name_getlabelsequence(&nsec.next, labels - nlabels,
						  nlabels, &common);
		}
		result = dns_name_concatenate(dns_wildcardname, &common,
					       wild, NULL);
		if (result != ISC_R_SUCCESS) {
			dns_rdata_freestruct(&nsec);
			validator_log(val, ISC_LOG_DEBUG(3),
				    "failure generating wildcard name");
			return (result);
		}
	}
	dns_rdata_freestruct(&nsec);
	validator_log(val, ISC_LOG_DEBUG(3), "nsec range ok");
	*exists = ISC_FALSE;
	return (ISC_R_SUCCESS);
}

/*%
 * Callback for when NSEC records have been validated.
 *
 * Looks for NOQNAME and NODATA proofs.
 *
 * Resumes nsecvalidate.
 */
static void
authvalidated(isc_task_t *task, isc_event_t *event) {
	dns_validatorevent_t *devent;
	dns_validator_t *val;
	dns_rdataset_t *rdataset;
	isc_boolean_t want_destroy;
	isc_result_t result;
	isc_boolean_t exists, data;

	UNUSED(task);
	INSIST(event->ev_type == DNS_EVENT_VALIDATORDONE);

	devent = (dns_validatorevent_t *)event;
	rdataset = devent->rdataset;
	val = devent->ev_arg;
	result = devent->result;
	dns_validator_destroy(&val->subvalidator);

	INSIST(val->event != NULL);

	validator_log(val, ISC_LOG_DEBUG(3), "in authvalidated");
	LOCK(&val->lock);
	if (result != ISC_R_SUCCESS) {
		validator_log(val, ISC_LOG_DEBUG(3),
			      "authvalidated: got %s",
			      isc_result_totext(result));
		if (result == ISC_R_CANCELED)
			validator_done(val, result);
		else {
			result = nsecvalidate(val, ISC_TRUE);
			if (result != DNS_R_WAIT)
				validator_done(val, result);
		}
	} else {
		dns_name_t **proofs = val->event->proofs;
		dns_name_t *wild = dns_fixedname_name(&val->wild);
		
		if (rdataset->trust == dns_trust_secure)
			val->seensig = ISC_TRUE;

		if (rdataset->type == dns_rdatatype_nsec &&
		    rdataset->trust == dns_trust_secure &&
		    ((val->attributes & VALATTR_NEEDNODATA) != 0 ||
		     (val->attributes & VALATTR_NEEDNOQNAME) != 0) &&
	            (val->attributes & VALATTR_FOUNDNODATA) == 0 &&
		    (val->attributes & VALATTR_FOUNDNOQNAME) == 0 &&
		    nsecnoexistnodata(val, val->event->name, devent->name,
				      rdataset, &exists, &data, wild)
				      == ISC_R_SUCCESS)
		{
			if (exists && !data) {
				val->attributes |= VALATTR_FOUNDNODATA;
				if (NEEDNODATA(val))
					proofs[DNS_VALIDATOR_NODATAPROOF] =
						devent->name;
			}
			if (!exists) {
				val->attributes |= VALATTR_FOUNDNOQNAME;
				if (NEEDNOQNAME(val))
					proofs[DNS_VALIDATOR_NOQNAMEPROOF] =
						devent->name;
			}
		}
		result = nsecvalidate(val, ISC_TRUE);
		if (result != DNS_R_WAIT)
			validator_done(val, result);
	}
	want_destroy = exit_check(val);
	UNLOCK(&val->lock);
	if (want_destroy)
		destroy(val);

	/*
	 * Free stuff from the event.
	 */
	isc_event_free(&event);
}

/*%
 * Looks for the requested name and type in the view (zones and cache).
 *
 * When looking for a DLV record also checks to make sure the NSEC record
 * returns covers the query name as part of aggressive negative caching.
 *
 * Returns:
 * \li	ISC_R_SUCCESS
 * \li	ISC_R_NOTFOUND
 * \li	DNS_R_NCACHENXDOMAIN
 * \li	DNS_R_NCACHENXRRSET
 * \li	DNS_R_NXRRSET
 * \li	DNS_R_NXDOMAIN
 */
static inline isc_result_t
view_find(dns_validator_t *val, dns_name_t *name, dns_rdatatype_t type) {
	dns_fixedname_t fixedname;
	dns_name_t *foundname;
	dns_rdata_nsec_t nsec;
	dns_rdata_t rdata = DNS_RDATA_INIT;
	isc_result_t result;
	unsigned int options;
	char buf1[DNS_NAME_FORMATSIZE];
	char buf2[DNS_NAME_FORMATSIZE];
	char buf3[DNS_NAME_FORMATSIZE];

	if (dns_rdataset_isassociated(&val->frdataset))
		dns_rdataset_disassociate(&val->frdataset);
	if (dns_rdataset_isassociated(&val->fsigrdataset))
		dns_rdataset_disassociate(&val->fsigrdataset);

	if (val->view->zonetable == NULL)
		return (ISC_R_CANCELED);

	options = DNS_DBFIND_PENDINGOK;
	if (type == dns_rdatatype_dlv)
		options |= DNS_DBFIND_COVERINGNSEC;
	dns_fixedname_init(&fixedname);
	foundname = dns_fixedname_name(&fixedname);
	result = dns_view_find(val->view, name, type, 0, options,
			       ISC_FALSE, NULL, NULL, foundname,
			       &val->frdataset, &val->fsigrdataset);
	if (result == DNS_R_NXDOMAIN) {
		if (dns_rdataset_isassociated(&val->frdataset))
			dns_rdataset_disassociate(&val->frdataset);
		if (dns_rdataset_isassociated(&val->fsigrdataset))
			dns_rdataset_disassociate(&val->fsigrdataset);
	} else if (result == DNS_R_COVERINGNSEC) {
		validator_log(val, ISC_LOG_DEBUG(3), "DNS_R_COVERINGNSEC");
		/*
		 * Check if the returned NSEC covers the name.
		 */
		INSIST(type == dns_rdatatype_dlv);
		if (val->frdataset.trust != dns_trust_secure) {
			validator_log(val, ISC_LOG_DEBUG(3),
				      "covering nsec: trust %u",
				      val->frdataset.trust);
			goto notfound;
		}
		result = dns_rdataset_first(&val->frdataset);
		if (result != ISC_R_SUCCESS)
			goto notfound;
		dns_rdataset_current(&val->frdataset, &rdata);
		if (dns_nsec_typepresent(&rdata, dns_rdatatype_ns) &&
		    !dns_nsec_typepresent(&rdata, dns_rdatatype_soa)) {
			/* Parent NSEC record. */
			if (dns_name_issubdomain(name, foundname)) {
				validator_log(val, ISC_LOG_DEBUG(3),
					      "covering nsec: for parent");
				goto notfound;
			}
		}
		result = dns_rdata_tostruct(&rdata, &nsec, NULL);
		if (result != ISC_R_SUCCESS)
			goto notfound;
		if (dns_name_compare(foundname, &nsec.next) >= 0) {
			/* End of zone chain. */
			if (!dns_name_issubdomain(name, &nsec.next)) {
				/*
 				 * XXXMPA We could look for a parent NSEC
				 * at nsec.next and if found retest with
				 * this NSEC.
				 */
				dns_rdata_freestruct(&nsec);
				validator_log(val, ISC_LOG_DEBUG(3),
					      "covering nsec: not in zone");
				goto notfound;
			}
		} else if (dns_name_compare(name, &nsec.next) >= 0) {
			/*
			 * XXXMPA We could check if this NSEC is at a zone
			 * apex and if the qname is not below it and look for
			 * a parent NSEC with the same name.  This requires
			 * that we can cache both NSEC records which we
			 * currently don't support.
			 */
			dns_rdata_freestruct(&nsec);
			validator_log(val, ISC_LOG_DEBUG(3),
				      "covering nsec: not in range");
			goto notfound;
		}
		if (isc_log_wouldlog(dns_lctx,ISC_LOG_DEBUG(3))) {
			dns_name_format(name, buf1, sizeof buf1);
			dns_name_format(foundname, buf2, sizeof buf2);
			dns_name_format(&nsec.next, buf3, sizeof buf3);
			validator_log(val, ISC_LOG_DEBUG(3),