rdataset.c

非常好的dns解析软件

		sorted = sorted_fixed;
	}

	if (shuffle) {
		/*
		 * First we get handles to all of the rdata.
		 */
		i = 0;
		do {
			INSIST(i < count);
			dns_rdata_init(&shuffled[i]);
			dns_rdataset_current(rdataset, &shuffled[i]);
			i++;
			result = dns_rdataset_next(rdataset);
		} while (result == ISC_R_SUCCESS);
		if (result != ISC_R_NOMORE)
			goto cleanup;
		INSIST(i == count);

		/*
		 * Now we shuffle.
		 */
		if (WANT_FIXED(rdataset)) {
			/*
			 * 'Fixed' order.
			 */
			INSIST(order != NULL);
			for (i = 0; i < count; i++) {
				sorted[i].key = (*order)(&shuffled[i],
							 order_arg);
				sorted[i].rdata = &shuffled[i];
			}
		} else if (WANT_RANDOM(rdataset)) {
			/*
			 * 'Random' order.
			 */
			for (i = 0; i < count; i++) {
				dns_rdata_t rdata;
				isc_uint32_t val;

				isc_random_get(&val);
				choice = i + (val % (count - i));
				rdata = shuffled[i];
				shuffled[i] = shuffled[choice];
				shuffled[choice] = rdata;
				if (order != NULL)
					sorted[i].key = (*order)(&shuffled[i],
								 order_arg);
				else
					sorted[i].key = 0; /* Unused */
				sorted[i].rdata = &shuffled[i];
			}
		} else {
			/*
			 * "Cyclic" order.
			 */
			isc_uint32_t val;
			unsigned int j;

			val = rdataset->count;
			if (val == ISC_UINT32_MAX)
				isc_random_get(&val);
			j = val % count;
			for (i = 0; i < count; i++) {
				if (order != NULL)
					sorted[j].key = (*order)(&shuffled[i],
								 order_arg);
				else
					sorted[j].key = 0; /* Unused */
				sorted[j].rdata = &shuffled[i];
				j++;
				if (j == count)
					j = 0; /* Wrap around. */
			}
		}

		/*
		 * Sorted order.
		 */
		if (order != NULL)
			qsort(sorted, count, sizeof(sorted[0]),
			      towire_compare);
	}

	savedbuffer = *target;
	i = 0;
	added = 0;

	do {
		/*
		 * Copy out the name, type, class, ttl.
		 */
		
		rrbuffer = *target;
		dns_compress_setmethods(cctx, DNS_COMPRESS_GLOBAL14);
		result = dns_name_towire(owner_name, cctx, target);
		if (result != ISC_R_SUCCESS)
			goto rollback;
		headlen = sizeof(dns_rdataclass_t) + sizeof(dns_rdatatype_t);
		if (!question)
			headlen += sizeof(dns_ttl_t)
				+ 2;  /* XXX 2 for rdata len */
		isc_buffer_availableregion(target, &r);
		if (r.length < headlen) {
			result = ISC_R_NOSPACE;
			goto rollback;
		}
		isc_buffer_putuint16(target, rdataset->type);
		isc_buffer_putuint16(target, rdataset->rdclass);
		if (!question) {
			isc_buffer_putuint32(target, rdataset->ttl);

			/*
			 * Save space for rdlen.
			 */
			rdlen = *target;
			isc_buffer_add(target, 2);

			/*
			 * Copy out the rdata
			 */
			if (shuffle)
				rdata = *(sorted[i].rdata);
			else {
				dns_rdata_reset(&rdata);
				dns_rdataset_current(rdataset, &rdata);
			}
			result = dns_rdata_towire(&rdata, cctx, target);
			if (result != ISC_R_SUCCESS)
				goto rollback;
			INSIST((target->used >= rdlen.used + 2) &&
			       (target->used - rdlen.used - 2 < 65536));
			isc_buffer_putuint16(&rdlen,
					     (isc_uint16_t)(target->used -
							    rdlen.used - 2));
			added++;
		}

		if (shuffle) {
			i++;
			if (i == count)
				result = ISC_R_NOMORE;
			else
				result = ISC_R_SUCCESS;
		} else {
			result = dns_rdataset_next(rdataset);
		}
	} while (result == ISC_R_SUCCESS);

	if (result != ISC_R_NOMORE)
		goto rollback;

	*countp += count;

	result = ISC_R_SUCCESS;
	goto cleanup;

 rollback:
	if (partial && result == ISC_R_NOSPACE) {
		INSIST(rrbuffer.used < 65536);
		dns_compress_rollback(cctx, (isc_uint16_t)rrbuffer.used);
		*countp += added;
		*target = rrbuffer;
		goto cleanup;
	}
	INSIST(savedbuffer.used < 65536);
	dns_compress_rollback(cctx, (isc_uint16_t)savedbuffer.used);
	*countp = 0;
	*target = savedbuffer;

 cleanup:
	if (sorted != NULL && sorted != sorted_fixed)
		isc_mem_put(cctx->mctx, sorted, count * sizeof(*sorted));
	if (shuffled != NULL && shuffled != shuffled_fixed)
		isc_mem_put(cctx->mctx, shuffled, count * sizeof(*shuffled));
	return (result);
}

isc_result_t
dns_rdataset_towiresorted(dns_rdataset_t *rdataset,
			  const dns_name_t *owner_name,
			  dns_compress_t *cctx,
			  isc_buffer_t *target,
			  dns_rdatasetorderfunc_t order,
			  const void *order_arg,
			  unsigned int options,
			  unsigned int *countp)
{
	return (towiresorted(rdataset, owner_name, cctx, target,
			     order, order_arg, ISC_FALSE, options,
			     countp, NULL));
}

isc_result_t
dns_rdataset_towirepartial(dns_rdataset_t *rdataset,
			   const dns_name_t *owner_name,
			   dns_compress_t *cctx,
			   isc_buffer_t *target,
			   dns_rdatasetorderfunc_t order,
			   const void *order_arg,
			   unsigned int options,
			   unsigned int *countp,
			   void **state)
{
	REQUIRE(state == NULL);	/* XXX remove when implemented */
	return (towiresorted(rdataset, owner_name, cctx, target,
			     order, order_arg, ISC_TRUE, options,
			     countp, state));
}

isc_result_t
dns_rdataset_towire(dns_rdataset_t *rdataset,
		    dns_name_t *owner_name,
		    dns_compress_t *cctx,
		    isc_buffer_t *target,
		    unsigned int options,
		    unsigned int *countp)
{
	return (towiresorted(rdataset, owner_name, cctx, target,
			     NULL, NULL, ISC_FALSE, options, countp, NULL));
}

isc_result_t
dns_rdataset_additionaldata(dns_rdataset_t *rdataset,
			    dns_additionaldatafunc_t add, void *arg)
{
	dns_rdata_t rdata = DNS_RDATA_INIT;
	isc_result_t result;

	/*
	 * For each rdata in rdataset, call 'add' for each name and type in the
	 * rdata which is subject to additional section processing.
	 */

	REQUIRE(DNS_RDATASET_VALID(rdataset));
	REQUIRE((rdataset->attributes & DNS_RDATASETATTR_QUESTION) == 0);

	result = dns_rdataset_first(rdataset);
	if (result != ISC_R_SUCCESS)
		return (result);

	do {
		dns_rdataset_current(rdataset, &rdata);
		result = dns_rdata_additionaldata(&rdata, add, arg);
		if (result == ISC_R_SUCCESS)
			result = dns_rdataset_next(rdataset);
		dns_rdata_reset(&rdata);
	} while (result == ISC_R_SUCCESS);

	if (result != ISC_R_NOMORE)
		return (result);

	return (ISC_R_SUCCESS);
}

isc_result_t
dns_rdataset_addnoqname(dns_rdataset_t *rdataset, dns_name_t *name) {

	REQUIRE(DNS_RDATASET_VALID(rdataset));
	REQUIRE(rdataset->methods != NULL);
	if (rdataset->methods->addnoqname == NULL)
		return (ISC_R_NOTIMPLEMENTED);
	return((rdataset->methods->addnoqname)(rdataset, name));
}

isc_result_t
dns_rdataset_getnoqname(dns_rdataset_t *rdataset, dns_name_t *name,
		        dns_rdataset_t *nsec, dns_rdataset_t *nsecsig)
{
	REQUIRE(DNS_RDATASET_VALID(rdataset));
	REQUIRE(rdataset->methods != NULL);

	if (rdataset->methods->getnoqname == NULL)
		return (ISC_R_NOTIMPLEMENTED);
	return((rdataset->methods->getnoqname)(rdataset, name, nsec, nsecsig));
}

/*
 * Additional cache stuff
 */
isc_result_t
dns_rdataset_getadditional(dns_rdataset_t *rdataset,
			   dns_rdatasetadditional_t type,
			   dns_rdatatype_t qtype,
			   dns_acache_t *acache,
			   dns_zone_t **zonep,
			   dns_db_t **dbp,
			   dns_dbversion_t **versionp,
			   dns_dbnode_t **nodep,
			   dns_name_t *fname,
			   dns_message_t *msg,
			   isc_stdtime_t now)
{
	REQUIRE(DNS_RDATASET_VALID(rdataset));
	REQUIRE(rdataset->methods != NULL);
	REQUIRE(zonep == NULL || *zonep == NULL);
	REQUIRE(dbp != NULL && *dbp == NULL);
	REQUIRE(versionp != NULL && *versionp == NULL);
	REQUIRE(nodep != NULL && *nodep == NULL);
	REQUIRE(fname != NULL);
	REQUIRE(msg != NULL);

	if (acache != NULL && rdataset->methods->getadditional != NULL) {
		return ((rdataset->methods->getadditional)(rdataset, type,
							   qtype, acache,
							   zonep, dbp,
							   versionp, nodep,
							   fname, msg, now));
	}

	return (ISC_R_FAILURE);
}

isc_result_t
dns_rdataset_setadditional(dns_rdataset_t *rdataset,
			   dns_rdatasetadditional_t type,
			   dns_rdatatype_t qtype,
			   dns_acache_t *acache,
			   dns_zone_t *zone,
			   dns_db_t *db,
			   dns_dbversion_t *version,
			   dns_dbnode_t *node,
			   dns_name_t *fname)
{
	REQUIRE(DNS_RDATASET_VALID(rdataset));
	REQUIRE(rdataset->methods != NULL);

	if (acache != NULL && rdataset->methods->setadditional != NULL) {
		return ((rdataset->methods->setadditional)(rdataset, type,
							   qtype, acache, zone,
							   db, version,
							   node, fname));
	}

	return (ISC_R_FAILURE);
}

isc_result_t
dns_rdataset_putadditional(dns_acache_t *acache,
			   dns_rdataset_t *rdataset,
			   dns_rdatasetadditional_t type,
			   dns_rdatatype_t qtype)
{
	REQUIRE(DNS_RDATASET_VALID(rdataset));
	REQUIRE(rdataset->methods != NULL);

	if (acache != NULL && rdataset->methods->putadditional != NULL) {
		return ((rdataset->methods->putadditional)(acache, rdataset,
							   type, qtype));
	}

	return (ISC_R_FAILURE);
}