/*
 * difffile.c - DIFF file handling source code. Read and write diff files.
 *
 * Copyright (c) 2001-2006, NLnet Labs. All rights reserved.
 *
 * See LICENSE for the license.
 *
 */

#include "config.h"
#include <assert.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>
#include <inttypes.h>
#include "difffile.h"
#include "xfrd-disk.h"
#include "util.h"
#include "packet.h"
#include "rdata.h"
#include "udb.h"
#include "nsec3.h"
#include "nsd.h"
#include "rrl.h"
#include "ixfr.h"
#include "zonec.h"
#include "xfrd-catalog-zones.h"

static int
write_64(FILE *out, uint64_t val)
{
	return write_data(out, &val, sizeof(val));
}

static int
write_32(FILE *out, uint32_t val)
{
	val = htonl(val);
	return write_data(out, &val, sizeof(val));
}

static int
write_8(FILE *out, uint8_t val)
{
	return write_data(out, &val, sizeof(val));
}

static int
write_str(FILE *out, const char* str)
{
	uint32_t len = strlen(str);
	if(!write_32(out, len))
		return 0;
	return write_data(out, str, len);
}

void
diff_write_packet(const char* zone, const char* pat, uint32_t old_serial,
	uint32_t new_serial, uint32_t seq_nr, uint8_t* data, size_t len,
	struct nsd* nsd, uint64_t filenumber)
{
	FILE* df = xfrd_open_xfrfile(nsd, filenumber, seq_nr?"a":"w");
	if(!df) {
		log_msg(LOG_ERR, "could not open transfer %s file %lld: %s",
			zone, (long long)filenumber, strerror(errno));
		return;
	}

	/* if first part, first write the header */
	if(seq_nr == 0) {
		struct timeval tv;
		if (gettimeofday(&tv, NULL) != 0) {
			log_msg(LOG_ERR, "could not get timestamp for %s: %s",
				zone, strerror(errno));
		}
		if(!write_32(df, DIFF_PART_XFRF) ||
			!write_8(df, 0) /* notcommitted(yet) */ ||
			!write_32(df, 0) /* numberofparts when done */ ||
			!write_64(df, (uint64_t) tv.tv_sec) ||
			!write_32(df, (uint32_t) tv.tv_usec) ||
			!write_32(df, old_serial) ||
			!write_32(df, new_serial) ||
			!write_64(df, (uint64_t) tv.tv_sec) ||
			!write_32(df, (uint32_t) tv.tv_usec) ||
			!write_str(df, zone) ||
			!write_str(df, pat)) {
			log_msg(LOG_ERR, "could not write transfer %s file %lld: %s",
				zone, (long long)filenumber, strerror(errno));
			fclose(df);
			return;
		}
	}

	if(!write_32(df, DIFF_PART_XXFR) ||
		!write_32(df, len) ||
		!write_data(df, data, len) ||
		!write_32(df, len))
	{
		log_msg(LOG_ERR, "could not write transfer %s file %lld: %s",
			zone, (long long)filenumber, strerror(errno));
	}
	fclose(df);
}

void
diff_write_commit(const char* zone, uint32_t old_serial, uint32_t new_serial,
	uint32_t num_parts, uint8_t commit, const char* log_str,
	struct nsd* nsd, uint64_t filenumber)
{
	struct timeval tv;
	FILE* df;

	if (gettimeofday(&tv, NULL) != 0) {
		log_msg(LOG_ERR, "could not set timestamp for %s: %s",
			zone, strerror(errno));
	}

	/* overwrite the first part of the file with 'committed = 1', 
	 * as well as the end_time and number of parts.
	 * also write old_serial and new_serial, so that a bad file mixup
	 * will result in unusable serial numbers. */

	df = xfrd_open_xfrfile(nsd, filenumber, "r+");
	if(!df) {
		log_msg(LOG_ERR, "could not open transfer %s file %lld: %s",
			zone, (long long)filenumber, strerror(errno));
		return;
	}
	if(!write_32(df, DIFF_PART_XFRF) ||
		!write_8(df, commit) /* committed */ ||
		!write_32(df, num_parts) ||
		!write_64(df, (uint64_t) tv.tv_sec) ||
		!write_32(df, (uint32_t) tv.tv_usec) ||
		!write_32(df, old_serial) ||
		!write_32(df, new_serial))
	{
		log_msg(LOG_ERR, "could not write transfer %s file %lld: %s",
			zone, (long long)filenumber, strerror(errno));
		fclose(df);
		return;
	}

	/* append the log_str to the end of the file */
	if(fseek(df, 0, SEEK_END) == -1) {
		log_msg(LOG_ERR, "could not fseek transfer %s file %lld: %s",
			zone, (long long)filenumber, strerror(errno));
		fclose(df);
		return;
	}
	if(!write_str(df, log_str)) {
		log_msg(LOG_ERR, "could not write transfer %s file %lld: %s",
			zone, (long long)filenumber, strerror(errno));
		fclose(df);
		return;

	}
	fflush(df);
	fclose(df);
}

void
diff_update_commit(
	const char* zone, uint8_t commit, struct nsd* nsd, uint64_t filenumber)
{
	FILE *df;

	assert(zone != NULL);
	assert(nsd != NULL);
	assert(commit == DIFF_NOT_COMMITTED ||
	       commit == DIFF_COMMITTED ||
	       commit == DIFF_CORRUPT ||
	       commit == DIFF_INCONSISTENT ||
	       commit == DIFF_VERIFIED);

	df = xfrd_open_xfrfile(nsd, filenumber, "r+");
	if(!df) {
		log_msg(LOG_ERR, "could not open transfer %s file %lld: %s",
			zone, (long long)filenumber, strerror(errno));
		return;
	}
	if(!write_32(df, DIFF_PART_XFRF) || !write_8(df, commit)) {
		log_msg(LOG_ERR, "could not write transfer %s file %lld: %s",
			zone, (long long)filenumber, strerror(errno));
		fclose(df);
		return;
	}
	fflush(df);
	fclose(df);
}

int
diff_read_64(FILE *in, uint64_t* result)
{
	if (fread(result, sizeof(*result), 1, in) == 1) {
		return 1;
	} else {
		return 0;
	}
}

int
diff_read_32(FILE *in, uint32_t* result)
{
	if (fread(result, sizeof(*result), 1, in) == 1) {
		*result = ntohl(*result);
		return 1;
	} else {
		return 0;
	}
}

int
diff_read_8(FILE *in, uint8_t* result)
{
	if (fread(result, sizeof(*result), 1, in) == 1) {
		return 1;
	} else {
		return 0;
	}
}

int
diff_read_str(FILE* in, char* buf, size_t len)
{
	uint32_t disklen;
	if(!diff_read_32(in, &disklen))
		return 0;
	if(disklen >= len)
		return 0;
	if(fread(buf, disklen, 1, in) != 1)
		return 0;
	buf[disklen] = 0;
	return 1;
}

static void
add_rr_to_recyclebin(namedb_type* db, rr_type* rr)
{
	/* add rr and rdata to recycle bin. */
	region_recycle(db->region, rr, sizeof(rr_type) + rr->rdlength);
}

/* this routine determines if below a domain there exist names with
 * data (is_existing) or no names below the domain have data.
 */
static int
has_data_below(domain_type* top)
{
	domain_type* d = top;
	assert(d != NULL);
	/* in the canonical ordering subdomains are after this name */
	d = domain_next(d);
	while(d != NULL && domain_is_subdomain(d, top)) {
		if(d->is_existing)
			return 1;
		d = domain_next(d);
	}
	return 0;
}

/** check if domain with 0 rrsets has become empty (nonexist) */
static domain_type*
rrset_zero_nonexist_check(domain_type* domain, domain_type* ce)
{
	/* is the node now an empty node (completely deleted) */
	if(domain->rrsets == 0) {
		/* if there is no data below it, it becomes non existing.
		   also empty nonterminals above it become nonexisting */
		/* check for data below this node. */
		if(!has_data_below(domain)) {
			/* nonexist this domain and all parent empty nonterminals */
			domain_type* p = domain;
			while(p != NULL && p->rrsets == 0) {
				if(p == ce || has_data_below(p))
					return p;
				p->is_existing = 0;
				/* fixup wildcard child of parent */
				if(p->parent &&
					p->parent->wildcard_child_closest_match == p)
					p->parent->wildcard_child_closest_match = domain_previous_existing_child(p);
				p = p->parent;
			}
		}
	}
	return NULL;
}

/** remove rrset.  Adjusts zone params.  Does not remove domain */
static void
rrset_delete(namedb_type* db, domain_type* domain, rrset_type* rrset)
{
	int i;
	/* find previous */
	rrset_type** pp = &domain->rrsets;
	while(*pp && *pp != rrset) {
		pp = &( (*pp)->next );
	}
	if(!*pp) {
		/* rrset does not exist for domain */
		return;
	}
	*pp = rrset->next;

	DEBUG(DEBUG_XFRD,2, (LOG_INFO, "delete rrset of %s type %s",
		domain_to_string(domain),
		rrtype_to_string(rrset_rrtype(rrset))));

	/* is this a SOA rrset ? */
	if(rrset->zone->soa_rrset == rrset) {
		rrset->zone->soa_rrset = 0;
	}
	if(rrset->zone->ns_rrset == rrset) {
		rrset->zone->ns_rrset = 0;
	}
	if(domain == rrset->zone->apex && rrset_rrtype(rrset) == TYPE_RRSIG) {
		for (i = 0; i < rrset->rr_count; ++i) {
			if(rr_rrsig_type_covered(rrset->rrs[i])==TYPE_DNSKEY) {
				rrset->zone->is_secure = 0;
				break;
			}
		}
	}
	/* recycle the memory space of the rrset */
	for (i = 0; i < rrset->rr_count; ++i)
		add_rr_to_recyclebin(db, rrset->rrs[i]);
#ifndef PACKED_STRUCTS
	region_recycle(db->region, rrset->rrs, sizeof(rr_type*) * rrset->rr_count);
	rrset->rr_count = 0;
#endif
	region_recycle(db->region, rrset, sizeof(rrset_type)
#ifdef PACKED_STRUCTS
		+ rrset->rr_count*sizeof(rr_type*)
#endif
		);
}

static int
rdatas_equal(const rr_type *rr1, const rr_type *rr2, uint16_t type,
	int* rdnum, char** reason)
{
	size_t offset = 0;
	const nsd_type_descriptor_type *descriptor;

	if(rr1->rdlength != rr2->rdlength) {
		*rdnum = 0;
		*reason = "rr length different";
		return 0;
	}
	assert(rr1->rdlength == rr2->rdlength);

	/**
	 * SOA RDATA comparisons in XFR are more lenient,
	 * only serial rdata is checked.
	 **/
	if (type == TYPE_SOA) {
		offset = 2 * sizeof(void*);
		if(rr1->rdlength != offset + 20) {
			*rdnum = 0;
			*reason = "invalid SOA length";
			return 0;
		}
		assert(rr1->rdlength == offset + 20);
		if (memcmp(rr1->rdata + offset, rr2->rdata + offset, 4) == 0)
			return 1;
		*rdnum = 2;
		*reason = "rdata data";
		return 0;
	}

	if (memcmp(rr1->rdata, rr2->rdata, rr1->rdlength) == 0)
		return 1;

	descriptor = nsd_type_descriptor(type);
	for (size_t i=0; i < descriptor->rdata.length && offset < rr1->rdlength; i++) {
		uint16_t field_len1, field_len2;
		struct domain *domain1, *domain2;
		if(offset == rr1->rdlength &&
			descriptor->rdata.fields[i].is_optional)
			break;
		if(!lookup_rdata_field_entry(descriptor, i, rr1, offset,
			&field_len1, &domain1)) {
			*rdnum = i;
			*reason = "malformed field rr1";
			return 0;
		}
		if(!lookup_rdata_field_entry(descriptor, i, rr2, offset,
			&field_len2, &domain2)) {
			*rdnum = i;
			*reason = "malformed field rr2";
			return 0;
		}
		if(domain1 && domain2) {
			const struct dname *dname1, *dname2;
			dname1 = domain_dname(domain1);
			dname2 = domain_dname(domain2);
			if (dname_compare(dname1, dname2) != 0) {
				*rdnum = i;
				*reason = "dname data";
				return 0;
			}
			offset += field_len1;
			continue;
		} else if(descriptor->rdata.fields[i].length ==
			RDATA_LITERAL_DNAME) {
			uint8_t length1, length2;
			const uint8_t *name1 = rr1->rdata + offset;
			const uint8_t *name2 = rr2->rdata + offset;
			if(field_len1 != field_len2) {
				*rdnum = i;
				*reason = "literal dname field len";
				return 0;
			}
			length1 = buf_dname_length(name1, rr1->rdlength - offset);
			length2 = buf_dname_length(name2, rr2->rdlength - offset);

			if (!length1 || !length2 || length1 != length2) {
				*rdnum = i;
				*reason = "literal dname len";
				return 0;
			}
			if (!dname_equal_nocase((uint8_t*)name1, (uint8_t*)name2, length1)) {
				*rdnum = i;
				*reason = "literal dname data";
				return 0;
			}
			offset += field_len1;
			continue;
		}
		if(field_len1 != field_len2) {
			*rdnum = i;
			*reason = "rdata len";
			return 0;
		}
		if(memcmp(rr1->rdata+offset, rr2->rdata+offset, field_len1) != 0) {
			*rdnum = i;
			*reason = "rdata data";
			return 0;
		}
		offset += field_len1;
	}

	return 1;
}

static void
debug_find_rr_num(rrset_type* rrset, uint16_t type, uint16_t klass,
	rr_type *rr)
{
	int i, rd;
	char* reason = "";

	for(i=0; i < rrset->rr_count; ++i) {
		if (rrset->rrs[i]->type != type) {
			log_msg(LOG_WARNING, "diff: RR <%s, %s> does not match "
				"RR num %d type %s",
				dname_to_string(domain_dname(rrset->rrs[i]->owner),0),
				rrtype_to_string(type),	i,
				rrtype_to_string(rrset->rrs[i]->type));
			continue; /* rdata equality needs same type. */
		}
		if (rrset->rrs[i]->klass != klass) {
			log_msg(LOG_WARNING, "diff: RR <%s, %s> class %d "
				"does not match RR num %d class %d",
				dname_to_string(domain_dname(rrset->rrs[i]->owner),0),
				rrtype_to_string(type),
				klass, i,
				rrset->rrs[i]->klass);
			continue;
		}
		if (rrset->rrs[i]->rdlength != rr->rdlength) {
			log_msg(LOG_WARNING, "diff: RR <%s, %s> rdlen %u "
				"does not match RR num %d rdlen %d",
				dname_to_string(domain_dname(rrset->rrs[i]->owner),0),
				rrtype_to_string(type),
				(unsigned) rr->rdlength, i,
				(unsigned) rrset->rrs[i]->rdlength);
		}
		if (!rdatas_equal(rr, rrset->rrs[i], type,
			&rd, &reason)) {
			log_msg(LOG_WARNING, "diff: RR <%s, %s> rdata element "
				"%d differs from RR num %d rdata (%s)",
				dname_to_string(domain_dname(rrset->rrs[i]->owner),0),
				rrtype_to_string(type),
				rd, i, reason);
		}
	}
}

static int
find_rr_num(rrset_type* rrset, uint16_t type, uint16_t klass,
	rr_type *rr, int add)
{
	int i, rd;
	char* reason;

	for(i=0; i < rrset->rr_count; ++i) {
		if(rrset->rrs[i]->type == type &&
		   rrset->rrs[i]->klass == klass &&
		   rrset->rrs[i]->rdlength == rr->rdlength &&
		   rdatas_equal(rrset->rrs[i], rr, type,
			&rd, &reason))
		{
			return i;
		}
	}
	/* this is odd. Log why rr cannot be found. */
	if (!add) {
		debug_find_rr_num(rrset, type, klass, rr);
	}
	return -1;
}

#ifdef NSEC3
/* see if nsec3 deletion triggers need action */
static void
nsec3_delete_rr_trigger(namedb_type* db, rr_type* rr, zone_type* zone)
{
	/* the RR has not actually been deleted yet, so we can inspect it */
	if(!zone->nsec3_param)
		return;
	/* see if the domain was an NSEC3-domain in the chain, but no longer */
	if(rr->type == TYPE_NSEC3 && rr->owner->nsec3 &&
		rr->owner->nsec3->nsec3_node.key &&
		nsec3_rr_uses_params(rr, zone) &&
		nsec3_in_chain_count(rr->owner, zone) <= 1) {
		domain_type* prev = nsec3_chain_find_prev(zone, rr->owner);
		/* remove from prehash because no longer an NSEC3 domain */
		if(domain_is_prehash(db->domains, rr->owner))
			prehash_del(db->domains, rr->owner);
		/* fixup the last in the zone */
		if(rr->owner == zone->nsec3_last)
			zone->nsec3_last = prev;
		/* unlink from the nsec3tree */
		zone_del_domain_in_hash_tree(zone->nsec3tree,
			&rr->owner->nsec3->nsec3_node);
		/* add previous NSEC3 to the prehash list */
		if(prev && prev != rr->owner)
			prehash_add(db->domains, prev);
		else	nsec3_clear_precompile(db, zone);
		/* this domain becomes ordinary data domain: done later */
	}
	/* see if the rr was NSEC3PARAM that we were using */
	else if(rr->type == TYPE_NSEC3PARAM && rr == zone->nsec3_param) {
		/* clear trees, wipe hashes, wipe precompile */
		nsec3_clear_precompile(db, zone);
		/* pick up new nsec3param (from udb, or avoid deleted rr) */
		nsec3_find_zone_param(db, zone, rr, 0);
		/* if no more NSEC3, done */
		if(!zone->nsec3_param)
			return;
		nsec3_precompile_newparam(db, zone);
	}
}

/* see if nsec3 prehash can be removed with new rrset content */
static void
nsec3_rrsets_changed_remove_prehash(domain_type* domain, zone_type* zone)
{
	/* deletion of rrset already done, we can check if conditions apply */
	/* see if the domain is no longer precompiled */
	/* it has a hash_node, but no longer fulfills conditions */
	if(nsec3_domain_part_of_zone(domain, zone) && domain->nsec3 &&
		domain->nsec3->hash_wc &&
		domain->nsec3->hash_wc->hash.node.key &&
		!nsec3_condition_hash(domain, zone)) {
		/* remove precompile */
		domain->nsec3->nsec3_cover = NULL;
		domain->nsec3->nsec3_wcard_child_cover = NULL;
		domain->nsec3->nsec3_is_exact = 0;
		/* remove it from the hash tree */
		zone_del_domain_in_hash_tree(zone->hashtree,
			&domain->nsec3->hash_wc->hash.node);
		zone_del_domain_in_hash_tree(zone->wchashtree,
			&domain->nsec3->hash_wc->wc.node);
	}
	if(domain != zone->apex && domain->nsec3 &&
		domain->nsec3->ds_parent_hash &&
		domain->nsec3->ds_parent_hash->node.key &&
		(!domain->parent || nsec3_domain_part_of_zone(domain->parent, zone)) &&
		!nsec3_condition_dshash(domain, zone)) {
		/* remove precompile */
		domain->nsec3->nsec3_ds_parent_cover = NULL;
		domain->nsec3->nsec3_ds_parent_is_exact = 0;
		/* remove it from the hash tree */
		zone_del_domain_in_hash_tree(zone->dshashtree,
			&domain->nsec3->ds_parent_hash->node);
	}
}

/* see if domain needs to get precompiled info */
static void
nsec3_rrsets_changed_add_prehash(namedb_type* db, domain_type* domain,
	zone_type* zone)
{
	if(!zone->nsec3_param)
		return;
	if((!domain->nsec3 || !domain->nsec3->hash_wc
	                   || !domain->nsec3->hash_wc->hash.node.key)
		&& nsec3_condition_hash(domain, zone)) {
		region_type* tmpregion = region_create(xalloc, free);
		nsec3_precompile_domain(db, domain, zone, tmpregion);
		region_destroy(tmpregion);
	}
	if((!domain->nsec3 || !domain->nsec3->ds_parent_hash
	                   || !domain->nsec3->ds_parent_hash->node.key)
		&& nsec3_condition_dshash(domain, zone)) {
		nsec3_precompile_domain_ds(db, domain, zone);
	}
}

/* see if nsec3 rrset-deletion triggers need action */
static void
nsec3_delete_rrset_trigger(namedb_type* db, domain_type* domain,
	zone_type* zone, uint16_t type)
{
	if(!zone->nsec3_param)
		return;
	nsec3_rrsets_changed_remove_prehash(domain, zone);
	/* for type nsec3, or a delegation, the domain may have become a
	 * 'normal' domain with its remaining data now */
	if(type == TYPE_NSEC3 || type == TYPE_NS || type == TYPE_DS)
		nsec3_rrsets_changed_add_prehash(db, domain, zone);
	/* for type DNAME or a delegation, obscured data may be revealed */
	if(type == TYPE_NS || type == TYPE_DS || type == TYPE_DNAME) {
		/* walk over subdomains and check them each */
		domain_type *d;
		for(d=domain_next(domain); d && domain_is_subdomain(d, domain);
			d=domain_next(d)) {
			nsec3_rrsets_changed_add_prehash(db, d, zone);
		}
	}
}

/* see if nsec3 addition triggers need action */
static void
nsec3_add_rr_trigger(namedb_type* db, rr_type* rr, zone_type* zone)
{
	/* the RR has been added in full, also to UDB (and thus NSEC3PARAM 
	 * in the udb has been adjusted) */
	if(zone->nsec3_param && rr->type == TYPE_NSEC3 &&
		(!rr->owner->nsec3 || !rr->owner->nsec3->nsec3_node.key)
		&& nsec3_rr_uses_params(rr, zone)) {
		if(!zone->nsec3_last) {
			/* all nsec3s have previously been deleted, but
			 * we have nsec3 parameters, set it up again from
			 * being cleared. */
			nsec3_precompile_newparam(db, zone);
		}
		/* added NSEC3 into the chain */
		nsec3_precompile_nsec3rr(db, rr->owner, zone);
		/* the domain has become an NSEC3-domain, if it was precompiled
		 * previously, remove that, neatly done in routine above */
		nsec3_rrsets_changed_remove_prehash(rr->owner, zone);
		/* set this NSEC3 to prehash */
		prehash_add(db->domains, rr->owner);
	} else if(!zone->nsec3_param && rr->type == TYPE_NSEC3PARAM) {
		/* see if this means NSEC3 chain can be used */
		nsec3_find_zone_param(db, zone, NULL, 0);
		if(!zone->nsec3_param)
			return;
		nsec3_zone_trees_create(db->region, zone);
		nsec3_precompile_newparam(db, zone);
	}
}

/* see if nsec3 rrset-addition triggers need action */
static void
nsec3_add_rrset_trigger(namedb_type* db, domain_type* domain, zone_type* zone,
	uint16_t type)
{
	/* the rrset has been added so we can inspect it */
	if(!zone->nsec3_param)
		return;
	/* because the rrset is added we can check conditions easily.
	 * check if domain needs to become precompiled now */
	nsec3_rrsets_changed_add_prehash(db, domain, zone);
	/* if a delegation, it changes from normal name to unhashed referral */
	if(type == TYPE_NS || type == TYPE_DS) {
		nsec3_rrsets_changed_remove_prehash(domain, zone);
	}
	/* if delegation or DNAME added, then some RRs may get obscured */
	if(type == TYPE_NS || type == TYPE_DS || type == TYPE_DNAME) {
		/* walk over subdomains and check them each */
		domain_type *d;
		for(d=domain_next(domain); d && domain_is_subdomain(d, domain);
			d=domain_next(d)) {
			nsec3_rrsets_changed_remove_prehash(d, zone);
		}
	}
}
#endif /* NSEC3 */

static void
rrset_lower_usage(namedb_type* db, rrset_type* rrset)
{
	unsigned i;
	for(i=0; i<rrset->rr_count; i++)
		rr_lower_usage(db, rrset->rrs[i]);
}

int
delete_RR(namedb_type* db, const dname_type* dname,
	uint16_t type, uint16_t klass, uint32_t ttl,
	buffer_type* packet, size_t rdatalen, zone_type *zone,
	region_type* temp_region, int* softfail, struct ixfr_store* ixfr_store)
{
	domain_type *domain;
	rrset_type *rrset;
#ifdef PACKED_STRUCTS
	rrset_type* rrset_prev;
#endif
	const nsd_type_descriptor_type *descriptor = nsd_type_descriptor(type);
	domain = domain_table_find(db->domains, dname);
	if(!domain) {
		log_msg(LOG_WARNING, "diff: domain %s does not exist",
			dname_to_string(dname,0));
		buffer_skip(packet, rdatalen);
		*softfail = 1;
		return 1; /* not fatal error */
	}
#ifndef PACKED_STRUCTS
	rrset = domain_find_rrset(domain, zone, type);
#else
	rrset = domain_find_rrset_and_prev(domain, zone, type, &rrset_prev);
#endif
	if(!rrset) {
		log_msg(LOG_WARNING, "diff: rrset %s does not exist",
			dname_to_string(dname,0));
		buffer_skip(packet, rdatalen);
		*softfail = 1;
		return 1; /* not fatal error */
	} else {
		/* find the RR in the rrset */
		domain_table_type *temptable;
		int32_t rrnum, code;
		struct rr *rr;
		temptable = domain_table_create(temp_region);
		/* This will ensure that the dnames in rdata are
		 * normalized, conform RFC 4035, section 6.2
		 */
		code = descriptor->read_rdata(temptable, rdatalen, packet, &rr);
		if(code < 0) {
			log_msg(LOG_ERR, "diff: could not read rdata for "
				"%s %s %s", dname_to_string(dname,0),
				rrtype_to_string(type),
				read_rdata_fail_str(code));
		}
		rr->owner = domain;
		rr->type = type;
		rr->klass = klass;
		rr->ttl = ttl;

		/* Now that the RR has been read with its RRtype specific read
		 * routine, store the read data and rdata, for an ixfr store.
		 * Store the delete RR information, for the softfail cases, the
		 * IXFR is stopped and an AXFR is attempted, so it would not
		 * need to be stored as the transfer is rejected. */
		if(ixfr_store)
			ixfr_store_delrr(ixfr_store, rr);

		rrnum = find_rr_num(rrset, type, klass, rr, 0);
		if(rrnum == -1 && type == TYPE_SOA && domain == zone->apex
			&& rrset->rr_count != 0)
			rrnum = 0; /* replace existing SOA if no match */
		if(rrnum == -1) {
			log_msg(LOG_WARNING, "diff: RR <%s, %s> does not exist",
				dname_to_string(dname,0), rrtype_to_string(type));
			*softfail = 1;
			return 1; /* not fatal error */
		}
#ifdef NSEC3
		/* process triggers for RR deletions */
		nsec3_delete_rr_trigger(db, rrset->rrs[rrnum], zone);
#endif
		/* lower usage (possibly deleting other domains, and thus
		 * invalidating the current RR's domain pointers) */
		rr_lower_usage(db, rrset->rrs[rrnum]);
		if(rrset->rr_count == 1) {
			/* delete entire rrset */
			rrset_delete(db, domain, rrset);
			/* check if domain is now nonexisting (or parents) */
			rrset_zero_nonexist_check(domain, NULL);
#ifdef NSEC3
			/* cleanup nsec3 */
			nsec3_delete_rrset_trigger(db, domain, zone, type);
#endif
			/* see if the domain can be deleted (and inspect parents) */
			domain_table_deldomain(db, domain);
		} else {
			/* swap out the bad RR and decrease the count */
#ifndef PACKED_STRUCTS
			rr_type** rrs_orig = rrset->rrs;
#else
			rrset_type* rrset_orig = rrset;
#endif
			add_rr_to_recyclebin(db, rrset->rrs[rrnum]);
			if(rrnum < rrset->rr_count-1)
				rrset->rrs[rrnum] = rrset->rrs[rrset->rr_count-1];
			rrset->rrs[rrset->rr_count-1] = NULL;
			/* realloc the rrs array one smaller */
#ifndef PACKED_STRUCTS
			rrset->rrs = region_alloc_array_init(db->region, rrs_orig,
				(rrset->rr_count-1), sizeof(rr_type*));
			if(!rrset->rrs) {
				log_msg(LOG_ERR, "out of memory, %s:%d", __FILE__, __LINE__);
				exit(1);
			}
			region_recycle(db->region, rrs_orig,
				sizeof(rr_type*) * rrset->rr_count);
#else
			rrset = region_alloc_init(db->region, rrset_orig,
				sizeof(rrset_type) +
				(rrset_orig->rr_count-1)*sizeof(rr_type*));
			if(!rrset) {
				log_msg(LOG_ERR, "out of memory, %s:%d", __FILE__, __LINE__);
				exit(1);
			}
			if(rrset_prev)
				rrset_prev->next = rrset;
			else	domain->rrsets = rrset;
			region_recycle(db->region, rrset_orig,
				sizeof(rrset_type) +
				rrset_orig->rr_count*sizeof(rr_type*));
			if(domain == zone->apex) {
				/* Because the rrset struct is reallocated,
				 * a pointer to it may need to be set again. */
				if(type == TYPE_SOA) {
					zone->soa_rrset = rrset;
				} else if(type == TYPE_NS) {
					zone->ns_rrset = rrset;
				}
			}
#endif /* PACKED_STRUCTS */
			rrset->rr_count --;
#ifdef NSEC3
			/* for type nsec3, the domain may have become a
			 * 'normal' domain with its remaining data now */
			if(type == TYPE_NSEC3)
				nsec3_rrsets_changed_add_prehash(db, domain,
					zone);
#endif /* NSEC3 */
		}
	}
	return 1;
}

static void
commit_RRset(namedb_type* db, zone_type* zone, struct collect_rrs* collect_rrs)
{
	struct rrset *rrset;

	if(!collect_rrs->domain || collect_rrs->rr_count == 0)
		return;
	if (!collect_rrs->rrset) {
#ifdef NSEC3
		domain_type* p;
#endif
		rrset = region_alloc(db->region, sizeof(*rrset)
#ifdef PACKED_STRUCTS
			+ sizeof(rr_type*) * collect_rrs->rr_count /* Add space for RRs. */
#endif
			);
		if(!rrset) {
			log_msg(LOG_ERR, "out of memory, %s:%d", __FILE__, __LINE__);
			exit(1);
		}
		rrset->zone = zone;
		rrset->rr_count = collect_rrs->rr_count;
#ifndef PACKED_STRUCTS
		rrset->rrs = region_alloc(db->region,
				sizeof(rr_type*) * collect_rrs->rr_count);
#endif
		memcpy(rrset->rrs, collect_rrs->rrs, collect_rrs->rr_count * sizeof(rr_type*));
		/* Add it */
		domain_add_rrset(collect_rrs->domain, rrset);
#ifdef NSEC3
		p = collect_rrs->domain->parent;
		nsec3_add_rrset_trigger(db, collect_rrs->domain, zone, collect_rrs->type);
		/* go up and process (possibly created) empty nonterminals, 
		 * until we hit the apex or root */
		while(p && p->rrsets == NULL && !p->is_apex) {
			nsec3_rrsets_changed_add_prehash(db, p, zone);
			p = p->parent;
		}
#endif
	} else {
#ifndef PACKED_STRUCTS
		struct rr **rrs;
#else
		struct rrset *rrset_orig;
#endif
		/* Add it... */
		rrset = collect_rrs->rrset;
#ifndef PACKED_STRUCTS
		rrs = rrset->rrs;
		rrset->rrs = region_alloc_array(
			db->region, rrset->rr_count + collect_rrs->rr_count, sizeof(*rrs));
		if(!rrset->rrs) {
			log_msg(LOG_ERR, "out of memory, %s:%d", __FILE__, __LINE__);
			exit(1);
		}
		if(rrs)
			memcpy(rrset->rrs, rrs, rrset->rr_count * sizeof(*rrs));
		region_recycle(db->region, rrs, rrset->rr_count * sizeof(*rrs));
#else
		rrset_orig = rrset;
		rrset = region_alloc(db->region,
			sizeof(rrset_type) +
			(rrset_orig->rr_count+collect_rrs->rr_count)*sizeof(rr_type*));
		if(!rrset) {
			log_msg(LOG_ERR, "out of memory, %s:%d", __FILE__, __LINE__);
			exit(1);
		}
		memcpy(rrset, rrset_orig,
			sizeof(rrset_type) +
			rrset_orig->rr_count*sizeof(rr_type*));
		if(collect_rrs->rrset_prev)
			collect_rrs->rrset_prev->next = rrset;
		else	collect_rrs->domain->rrsets = rrset;
		region_recycle(db->region, rrset_orig,
			sizeof(rrset_type) +
			rrset_orig->rr_count*sizeof(rr_type*));
#endif /* PACKED_STRUCTS */
		memcpy(rrset->rrs + rrset->rr_count, collect_rrs->rrs, collect_rrs->rr_count * sizeof(rr_type*));
		rrset->rr_count += collect_rrs->rr_count;
	}
	/* Check we have SOA */
	if (collect_rrs->domain == zone->apex)
		apex_rrset_checks(db, rrset, collect_rrs->domain);

	collect_rrs->domain = NULL;
	collect_rrs->type = -1;
	collect_rrs->rrset = NULL;
#ifdef PACKED_STRUCTS
	collect_rrs->rrset_prev = NULL;
#endif
#ifdef NSEC3
	for (int i = 0; i < collect_rrs->rr_count; i++) {
		nsec3_add_rr_trigger(db, collect_rrs->rrs[i], zone);
	}
#endif /* NSEC3 */
	collect_rrs->rr_count = 0;
}


int
add_RR(namedb_type* db, const dname_type* dname,
	uint16_t type, uint16_t klass, uint32_t ttl,
	buffer_type* packet, size_t rdatalen, zone_type *zone,
	int* softfail, struct ixfr_store* ixfr_store,
	struct collect_rrs* collect_rrs)
{
	domain_type* domain;
	rr_type *rr;
	int32_t code;
	const nsd_type_descriptor_type *descriptor;

	if (collect_rrs == NULL) {
		struct collect_rrs collect_rrs2;

		collect_rrs2.domain = NULL;
		collect_rrs2.type = -1;
		collect_rrs2.rrset = NULL;
#ifdef PACKED_STRUCTS
		collect_rrs2.rrset_prev = NULL;
#endif
		collect_rrs2.rr_count = 0;
		if (!add_RR(db, dname, type, klass, ttl, packet, rdatalen,
				zone, softfail, ixfr_store, &collect_rrs2)) {
			return 0;
		}
		commit_RRset(db, zone, &collect_rrs2);
		return 1;
	}
	domain = domain_table_insert(db->domains, dname);
	assert(domain);
	if (domain != collect_rrs->domain || type != collect_rrs->type
	||  collect_rrs->rr_count >= (int)(sizeof(collect_rrs->rrs) / sizeof(*collect_rrs->rrs))){
		commit_RRset(db, zone, collect_rrs);
		collect_rrs->domain = domain;
		collect_rrs->type = type;
		collect_rrs->rrset = NULL;
#ifdef PACKED_STRUCTS
		collect_rrs->rrset_prev = NULL;
#endif
	}

	/* dnames in rdata are normalized, conform RFC 4035,
	 * Section 6.2
	 */
	descriptor = nsd_type_descriptor(type);
	code = descriptor->read_rdata(db->domains, rdatalen, packet, &rr);
	if(code < 0) {
		log_msg(LOG_ERR, "diff: could not read rdata for %s %s %s",
			dname_to_string(dname,0), rrtype_to_string(type),
			read_rdata_fail_str(code));
		return 0;
	}
	rr->owner = domain;
	rr->type = type;
	rr->klass = klass;
	rr->ttl = ttl;

	/* Now that the RR has been read with its RRtype specific read
	 * routine, store the read data and rdata, for an ixfr store. */
	if (ixfr_store) {
		ixfr_store_addrr(ixfr_store, rr);
	}
	/* With the first RR for a RRset in this position in the zone transfer,
	 * find the RRset */
	if (collect_rrs->rr_count == 0)  {
#ifndef PACKED_STRUCTS
		collect_rrs->rrset = domain_find_rrset(collect_rrs->domain, zone, collect_rrs->type);
#else
		collect_rrs->rrset = domain_find_rrset_and_prev(collect_rrs->domain, zone, collect_rrs->type, &collect_rrs->rrset_prev);
#endif
	}
	if (collect_rrs->rrset) {
		/* Search for possible duplicates in existing RRset */
		for (int i = 0; i < collect_rrs->rrset->rr_count; i++) {
			if (!equal_rr_rdata(descriptor, rr, collect_rrs->rrset->rrs[i]))
				continue;
			/* Discard the duplicates... */
			/* Lower the usage counter for domains in the rdata. */
			rr_lower_usage(db, rr);
			region_recycle(db->region, rr, sizeof(*rr) + rr->rdlength);
			DEBUG(DEBUG_XFRD, 2, (LOG_ERR, "diff: RR <%s, %s> already exists",
				dname_to_string(dname,0), rrtype_to_string(type)));
			/* ignore already existing RR: lenient accepting of messages */
			*softfail = 1;
			return 1;
		}
	}
	/* Search for possible duplicates in already batched RRs */
	for (int i = 0; i < collect_rrs->rr_count; i++) {
		if (!equal_rr_rdata(descriptor, rr, collect_rrs->rrs[i]))
			continue;
		/* Discard the duplicates... */
		/* Lower the usage counter for domains in the rdata. */
		rr_lower_usage(db, rr);
		region_recycle(db->region, rr, sizeof(*rr) + rr->rdlength);
		DEBUG(DEBUG_XFRD, 2, (LOG_ERR, "diff: RR <%s, %s> already exists",
			dname_to_string(dname,0), rrtype_to_string(type)));
		/* ignore already existing RR: lenient accepting of messages */
		*softfail = 1;
		return 1;
	}
	if(collect_rrs->rr_count + ( collect_rrs->rrset 
	                           ? collect_rrs->rrset->rr_count : 0) >= 65535) {
		log_msg(LOG_ERR, "diff: too many RRs at %s",
			dname_to_string(dname,0));
		return 0;
	}
	collect_rrs->rrs[collect_rrs->rr_count++] = rr;
	return 1;
}

static zone_type*
find_or_create_zone(namedb_type* db, const dname_type* zone_name,
	struct nsd_options* opt, const char* zstr, const char* patname)
{
	zone_type* zone;
	struct zone_options* zopt;
	zone = namedb_find_zone(db, zone_name);
	if(zone) {
		return zone;
	}
	zopt = zone_options_find(opt, zone_name);
	if(!zopt) {
		/* if _implicit_ then insert as _part_of_config */
		if(strncmp(patname, PATTERN_IMPLICIT_MARKER,
			strlen(PATTERN_IMPLICIT_MARKER)) == 0) {
			zopt = zone_options_create(opt->region);
			if(!zopt) return 0;
			zopt->part_of_config = 1;
			zopt->name = region_strdup(opt->region, zstr);
			zopt->pattern = pattern_options_find(opt, patname);
			if(!zopt->name || !zopt->pattern) return 0;
			if(!nsd_options_insert_zone(opt, zopt)) {
				log_msg(LOG_ERR, "bad domain name or duplicate zone '%s' "
					"pattern %s", zstr, patname);
			}
		} else {
			/* create zone : presumably already added to zonelist
			 * by xfrd, who wrote the AXFR or IXFR to disk, so we only
			 * need to add it to our config.
			 * This process does not need linesize and offset zonelist */
			zopt = zone_list_zone_insert(opt, zstr, patname);
			if(!zopt)
				return 0;
		}
	}
	zone = namedb_zone_create(db, zone_name, zopt);
	return zone;
}

void
delete_zone_rrs(namedb_type* db, zone_type* zone)
{
	rrset_type *rrset;
	domain_type *domain = zone->apex, *next;
	int nonexist_check = 0;
	/* go through entire tree below the zone apex (incl subzones) */
	while(domain && domain_is_subdomain(domain, zone->apex))
	{
		DEBUG(DEBUG_XFRD,2, (LOG_INFO, "delete zone visit %s",
			domain_to_string(domain)));
		/* delete all rrsets of the zone */
		while((rrset = domain_find_any_rrset(domain, zone))) {
			/* lower usage can delete other domains */
			rrset_lower_usage(db, rrset);
			/* rrset del does not delete our domain(yet) */
			rrset_delete(db, domain, rrset);
			/* no rrset_zero_nonexist_check, do that later */
			if(domain->rrsets == 0)
				nonexist_check = 1;
		}
		/* the delete upcoming could delete parents, but nothing next
		 * or after the domain so store next ptr */
		next = domain_next(domain);
		/* see if the domain can be deleted (and inspect parents) */
		domain_table_deldomain(db, domain);
		domain = next;
	}

	/* check if data deletions have created nonexisting domain entries,
	 * but after deleting domains so the checks are faster */
	if(nonexist_check) {
		domain_type* ce = NULL; /* for speeding up has_data_below */
		DEBUG(DEBUG_XFRD, 1, (LOG_INFO, "axfrdel: zero rrset check"));
		domain = zone->apex;
		while(domain && domain_is_subdomain(domain, zone->apex))
		{
			/* the interesting domains should be existing==1
			 * and rrsets==0, speeding up out processing of
			 * sub-zones, since we only spuriously check empty
			 * nonterminals */
			if(domain->is_existing)
				ce = rrset_zero_nonexist_check(domain, ce);
			domain = domain_next(domain);
		}
	}

	DEBUG(DEBUG_XFRD, 1, (LOG_INFO, "axfrdel: recyclebin holds %lu bytes",
		(unsigned long) region_get_recycle_size(db->region)));
#ifndef NDEBUG
	if(nsd_debug_level >= 2)
		region_log_stats(db->region);
#endif

	assert(zone->soa_rrset == 0);
	/* keep zone->soa_nx_rrset alloced: it is reused */
	assert(zone->ns_rrset == 0);
	assert(zone->is_secure == 0);
}

/* return value 0: syntaxerror,badIXFR, 1:OK, 2:done_and_skip_it */
static int
apply_ixfr(nsd_type* nsd, FILE *in, uint32_t serialno,
	uint32_t seq_nr, uint32_t seq_total,
	int* is_axfr, int* delete_mode, int* rr_count,
	struct zone* zone, uint64_t* bytes,
	int* softfail, struct ixfr_store* ixfr_store)
{
	uint32_t msglen, checklen, pkttype;
	int qcount, ancount;
	buffer_type* packet;
	region_type* region;
	struct collect_rrs collect_rrs;

	/* note that errors could not really happen due to format of the
	 * packet since xfrd has checked all dnames and RRs before commit,
	 * this is why the errors are fatal (exit process), it must be
	 * something internal or a bad disk or something. */

	/* read ixfr packet RRs and apply to in memory db */
	if(!diff_read_32(in, &pkttype) || pkttype != DIFF_PART_XXFR) {
		log_msg(LOG_ERR, "could not read type or wrong type");
		return 0;
	}

	if(!diff_read_32(in, &msglen)) {
		log_msg(LOG_ERR, "could not read len");
		return 0;
	}

	if(msglen < QHEADERSZ) {
		log_msg(LOG_ERR, "msg too short");
		return 0;
	}

	region = region_create(xalloc, free);
	if(!region) {
		log_msg(LOG_ERR, "out of memory");
		return 0;
	}
	packet = buffer_create(region, QIOBUFSZ);
	if(msglen > QIOBUFSZ) {
		log_msg(LOG_ERR, "msg too long");
		region_destroy(region);
		return 0;
	}
	buffer_clear(packet);
	if(fread(buffer_begin(packet), msglen, 1, in) != 1) {
		log_msg(LOG_ERR, "short fread: %s", strerror(errno));
		region_destroy(region);
		return 0;
	}
	buffer_set_limit(packet, msglen);

	/* see if check on data fails: checks that we are not reading
	 * random garbage */
	if(!diff_read_32(in, &checklen) || checklen != msglen) {
		log_msg(LOG_ERR, "transfer part has incorrect checkvalue");
		return 0;
	}
	*bytes += msglen;

	/* only answer section is really used, question, additional and
	   authority section RRs are skipped */
	qcount = QDCOUNT(packet);
	ancount = ANCOUNT(packet);
	buffer_skip(packet, QHEADERSZ);
	/* qcount should be 0 or 1 really, ancount limited by 64k packet */
	if(qcount > 64 || ancount > 65530) {
		log_msg(LOG_ERR, "RR count impossibly high");
		region_destroy(region);
		return 0;
	}

	/* skip queries */
	for(int i=0; i < qcount; ++i) {
		if(!packet_skip_rr(packet, 1)) {
			log_msg(LOG_ERR, "bad RR in question section");
			region_destroy(region);
			return 0;
		}
	}

	collect_rrs.domain = NULL;
	collect_rrs.type = -1;
	collect_rrs.rrset = NULL;
#ifdef PACKED_STRUCTS
	collect_rrs.rrset_prev = NULL;
#endif
	collect_rrs.rr_count = 0;

	DEBUG(DEBUG_XFRD, 2, (LOG_INFO, "diff: started packet %d/%d for zone %s",
		(int)seq_nr, (int)seq_total, domain_to_string(zone->apex)));

	for(int i=0; i < ancount; ++i, ++(*rr_count)) {
		const dname_type *owner;
		uint16_t type, klass, rrlen;
		uint32_t ttl;

		owner = dname_make_from_packet(region, packet, 1, 1);
		if(!owner) {
			log_msg(LOG_ERR, "bad xfr RR dname %d", *rr_count);
			region_destroy(region);
			return 0;
		}
		if(!buffer_available(packet, 10)) {
			log_msg(LOG_ERR, "bad xfr RR format %d", *rr_count);
			region_destroy(region);
			return 0;
		}
		type = buffer_read_u16(packet);
		klass = buffer_read_u16(packet);
		ttl = buffer_read_u32(packet);
		rrlen = buffer_read_u16(packet);
		if(!buffer_available(packet, rrlen)) {
			log_msg(LOG_ERR, "bad xfr RR rdata %d, len %d have %d",
				*rr_count, rrlen, (int)buffer_remaining(packet));
			region_destroy(region);
			return 0;
		}

		DEBUG(DEBUG_XFRD,2, (LOG_INFO, "diff: %s parsed count %d, ax %d, delmode %d",
			domain_to_string(zone->apex), *rr_count, *is_axfr, *delete_mode));

		if (type == TYPE_SOA) {
			size_t position;
			uint32_t serial;
			position = buffer_position(packet);
			if (!packet_skip_dname(packet) ||
					!packet_skip_dname(packet) ||
					buffer_remaining(packet) < sizeof(uint32_t) * 5)
			{
				log_msg(LOG_ERR, "bad xfr SOA RR formerr.");
				region_destroy(region);
				return 0;
			}

			serial = buffer_read_u32(packet);
			buffer_set_position(packet, position);

			/* first RR: check if SOA and correct zone & serialno */
			if (*rr_count == 0) {
				assert(!*is_axfr);
				assert(!*delete_mode);
				if (klass != CLASS_IN) {
					log_msg(LOG_ERR, "first RR not SOA IN");
					region_destroy(region);
					return 0;
				}
				if(dname_compare(domain_dname(zone->apex), owner) != 0) {
					log_msg(LOG_ERR, "SOA dname not equal to zone %s",
						domain_to_string(zone->apex));
					region_destroy(region);
					return 0;
				}
				if(serial != serialno) {
					log_msg(LOG_ERR, "SOA serial %u different from commit %u",
						(unsigned)serial, (unsigned)serialno);
					region_destroy(region);
					return 0;
				}
				buffer_skip(packet, rrlen);

				if(ixfr_store)
					ixfr_store_add_newsoa(ixfr_store, ttl, packet, rrlen);

				continue;
			} else if (*rr_count == 1) {
				assert(!*is_axfr);
				assert(!*delete_mode);
				/* if the serial no of the SOA equals the serialno, then AXFR */
				if (serial == serialno)
					goto axfr;
				*delete_mode = 1;
				/* must have stuff in memory for a successful IXFR,
				 * the serial number of the SOA has been checked
				 * previously (by check_for_bad_serial) if it exists */
				if(!domain_find_rrset(zone->apex, zone, TYPE_SOA)) {
					log_msg(LOG_ERR, "%s SOA serial %u is not "
						"in memory, skip IXFR", domain_to_string(zone->apex), serialno);
					region_destroy(region);
					/* break out and stop the IXFR, ignore it */
					return 2;
				}

				if(ixfr_store)
					ixfr_store_add_oldsoa(ixfr_store, ttl, packet, rrlen);
			} else if (!*is_axfr) {
				/* do not delete final SOA RR for IXFR */
				if (i == ancount - 1 && seq_nr == seq_total - 1) {
					if (ixfr_store) {
						ixfr_store_add_newsoa(ixfr_store, ttl, packet, rrlen);
					}
					*delete_mode = 0;
					buffer_skip(packet, rrlen);
					continue;
				} else
					*delete_mode = !*delete_mode;

				if (ixfr_store && *delete_mode) {
					ixfr_store_add_newsoa(ixfr_store, ttl, packet, rrlen);
					ixfr_store_finish(ixfr_store, nsd, NULL);
					ixfr_store_start(zone, ixfr_store);
					ixfr_store_add_oldsoa(ixfr_store, ttl, packet, rrlen);
				}
				/* switch from delete-part to add-part and back again,
				   just before soa - so it gets deleted and added too */
				DEBUG(DEBUG_XFRD,2, (LOG_INFO, "diff: %s IXFRswapdel count %d, ax %d, delmode %d",
					domain_to_string(zone->apex), *rr_count, *is_axfr, *delete_mode));
			}
		} else {
			if (*rr_count == 0) {
				log_msg(LOG_ERR, "first RR not SOA IN");
				region_destroy(region);
				return 0;
			/* second RR: if not SOA: this is an AXFR; delete all zone contents */
			} else if (*rr_count == 1) {
axfr:
				*is_axfr = 1;
#ifdef NSEC3
				nsec3_clear_precompile(nsd->db, zone);
				zone->nsec3_param = NULL;
#endif
				delete_zone_rrs(nsd->db, zone);
				if(ixfr_store) {
					ixfr_store_cancel(ixfr_store);
					ixfr_store_delixfrs(zone);
				}
				DEBUG(DEBUG_XFRD,2, (LOG_INFO, "diff: %s sawAXFR count %d, ax %d, delmode %d",
					domain_to_string(zone->apex), *rr_count, *is_axfr, *delete_mode));
			}
		}

		if(type == TYPE_TSIG || type == TYPE_OPT) {
			/* ignore pseudo RRs */
			buffer_skip(packet, rrlen);
			continue;
		}

		DEBUG(DEBUG_XFRD,2, (LOG_INFO, "xfr %s RR dname is %s type %s",
			*delete_mode?"del":"add",
			dname_to_string(owner, 0), rrtype_to_string(type)));
		if(*delete_mode) {
			assert(!*is_axfr);
			/* commit previous additions, if any. */
			commit_RRset(nsd->db, zone, &collect_rrs);
			/* delete this rr */
			if(!delete_RR(nsd->db, owner, type, klass, ttl, packet,
				rrlen, zone, region, softfail, ixfr_store)) {
				region_destroy(region);
				return 0;
			}
		} else {
			/* add this rr */
			if(!(add_RR(nsd->db, owner, type, klass, ttl, packet,
				rrlen, zone, softfail, ixfr_store, &collect_rrs))) {
				/* The collect_rrs->rrs that have not been committed yet, need to
				   have rr_lower_usage(db, collect_rrs.rrs[i]); for them. This is
				   needed to remove references to the db domain tree. However
				   the failure is fatal to the process, so it is not necessary. 
				   But we do it anyway in case with a future change this will
				   not be fatal to the process anymore.
				 */
				/* With all socked up RRs,
				 * lower the usage counter for domains in the rdata.
				 */
				for (int i = 0; i < collect_rrs.rr_count; i++) {
					/* Lower the usage counter for domains in the rdata. */
					rr_lower_usage( nsd->db, collect_rrs.rrs[i]);
					region_recycle( nsd->db->region, collect_rrs.rrs[i]
						      , sizeof(*collect_rrs.rrs[i])
						      + collect_rrs.rrs[i]->rdlength);
				}
				region_destroy(region);
				return 0;
			}
		}
	}
	commit_RRset(nsd->db, zone, &collect_rrs);
	region_destroy(region);
	return 1;
}

static int
check_for_bad_serial(namedb_type* db, const char* zone_str, uint32_t old_serial)
{
	/* see if serial OK with in-memory serial */
	domain_type* domain;
	region_type* region = region_create(xalloc, free);
	const dname_type* zone_name = dname_parse(region, zone_str);
	zone_type* zone = 0;
	domain = domain_table_find(db->domains, zone_name);
	if(domain)
		zone = domain_find_zone(db, domain);
	if(zone && zone->apex == domain && zone->soa_rrset && old_serial)
	{
		uint32_t memserial = 0;
		retrieve_soa_rdata_serial(zone->soa_rrset->rrs[0], &memserial);
		if(old_serial != memserial) {
			region_destroy(region);
			return 1;
		}
	}
	region_destroy(region);
	return 0;
}

int
apply_ixfr_for_zone(nsd_type* nsd, zone_type* zone, FILE* in,
	struct nsd_options* ATTR_UNUSED(opt), udb_base* taskudb, uint32_t xfrfilenr)
{
	char zone_buf[3072];
	char log_buf[5120];
	char patname_buf[2048];

	uint32_t old_serial, new_serial, num_parts, type;
	uint64_t time_end_0, time_start_0;
	uint32_t time_end_1, time_start_1;
	uint8_t committed;
	uint32_t i;
	uint64_t num_bytes = 0;
	assert(zone);

	/* read zone name and serial */
	if(!diff_read_32(in, &type)) {
		log_msg(LOG_ERR, "diff file too short");
		return 0;
	}
	if(type != DIFF_PART_XFRF) {
		log_msg(LOG_ERR, "xfr file has wrong format");
		return 0;

	}
	/* committed and num_parts are first because they need to be
	 * updated once the rest is written.  The log buf is not certain
	 * until its done, so at end of file.  The patname is in case a
	 * new zone is created, we know what the options-pattern is */
	if(!diff_read_8(in, &committed) ||
		!diff_read_32(in, &num_parts) ||
		!diff_read_64(in, &time_end_0) ||
		!diff_read_32(in, &time_end_1) ||
		!diff_read_32(in, &old_serial) ||
		!diff_read_32(in, &new_serial) ||
		!diff_read_64(in, &time_start_0) ||
		!diff_read_32(in, &time_start_1) ||
		!diff_read_str(in, zone_buf, sizeof(zone_buf)) ||
		!diff_read_str(in, patname_buf, sizeof(patname_buf))) {
		log_msg(LOG_ERR, "diff file bad commit part");
		return 0;
	}

	/* has been read in completely */
	if(strcmp(zone_buf, domain_to_string(zone->apex)) != 0) {
		log_msg(LOG_ERR, "file %s does not match task %s",
			zone_buf, domain_to_string(zone->apex));
		return 0;
	}
	switch(committed) {
	case DIFF_NOT_COMMITTED:
		log_msg(LOG_ERR, "diff file %s was not committed", zone_buf);
		return 0;
	case DIFF_CORRUPT:
		log_msg(LOG_ERR, "diff file %s was corrupt", zone_buf);
		return 0;
	case DIFF_INCONSISTENT:
		log_msg(LOG_ERR, "diff file %s was inconsistent", zone_buf);
		return 0;
	case DIFF_VERIFIED:
		log_msg(LOG_INFO, "diff file %s already verified", zone_buf);
		break;
	default:
		break;
	}
	if(num_parts == 0) {
		log_msg(LOG_ERR, "diff file %s was not completed", zone_buf);
		return 0;
	}
	if(check_for_bad_serial(nsd->db, zone_buf, old_serial)) {
		DEBUG(DEBUG_XFRD,1, (LOG_ERR,
			"skipping diff file commit with bad serial"));
		return -2; /* Success in "main" process, failure in "xfrd" */
	}

	if(!zone->is_skipped)
	{
		int is_axfr=0, delete_mode=0, rr_count=0, softfail=0;
		struct ixfr_store* ixfr_store = NULL, ixfr_store_mem;

		DEBUG(DEBUG_XFRD,1, (LOG_INFO, "processing xfr: %s", zone_buf));
		if(zone_is_ixfr_enabled(zone))
			ixfr_store = ixfr_store_start(zone, &ixfr_store_mem);
		/* read and apply all of the parts */
		for(i=0; i<num_parts; i++) {
			int ret;
			DEBUG(DEBUG_XFRD,2, (LOG_INFO, "processing xfr: apply part %d", (int)i));
			ret = apply_ixfr(nsd, in, new_serial,
				i, num_parts, &is_axfr, &delete_mode,
				&rr_count, zone,
				&num_bytes, &softfail, ixfr_store);
			if(ret == 0) {
				log_msg(LOG_ERR, "bad ixfr packet part %d in diff file for %s", (int)i, zone_buf);
				diff_update_commit(
					zone_buf, DIFF_CORRUPT, nsd, xfrfilenr);
				/* the udb is still dirty, it is bad */
				return -1; /* Fatal! */
			} else if(ret == 2) {
				break;
			}
		}
		/* read the final log_str: but do not fail on it */
		if(!diff_read_str(in, log_buf, sizeof(log_buf))) {
			log_msg(LOG_ERR, "could not read log for transfer %s",
				zone_buf);
			snprintf(log_buf, sizeof(log_buf), "error reading log");
		}
#ifdef NSEC3
		prehash_zone(nsd->db, zone);
#endif /* NSEC3 */
		zone->is_changed = 1;
		zone->is_updated = 1;
		zone->is_checked = (committed == DIFF_VERIFIED);
		zone->mtime.tv_sec = time_end_0;
		zone->mtime.tv_nsec = time_end_1*1000;
		if(zone->logstr)
			region_recycle(nsd->db->region, zone->logstr,
				strlen(zone->logstr)+1);
		zone->logstr = region_strdup(nsd->db->region, log_buf);
		namedb_zone_free_filenames(nsd->db, zone);
		if(softfail && taskudb && !is_axfr) {
			log_msg(LOG_ERR, "Failed to apply IXFR cleanly "
				"(deletes nonexistent RRs, adds existing RRs). "
				"Zone %s contents is different from primary, "
				"starting AXFR. Transfer %s", zone_buf, log_buf);
			/* add/del failures in IXFR, get an AXFR */
			diff_update_commit(
				zone_buf, DIFF_INCONSISTENT, nsd, xfrfilenr);
			return -1; /* Fatal! */
		}
		if(ixfr_store)
			ixfr_store_finish(ixfr_store, nsd, log_buf);

		if(1 <= verbosity) {
			double elapsed = (double)(time_end_0 - time_start_0)+
				(double)((double)time_end_1
				-(double)time_start_1) / 1000000.0;
			VERBOSITY(1, (LOG_INFO, "zone %s %s of %"PRIu64" bytes in %g seconds",
				zone_buf, log_buf, num_bytes, elapsed));
		}
	}
	else {
		DEBUG(DEBUG_XFRD,1, (LOG_INFO, "skipping xfr: %s", zone_buf));
	}
	return 1;
}

static void udb_task_walk_chunk(void* base, void* d, uint64_t s, udb_walk_relptr_cb* cb, void *arg)
{
  struct task_list_d* p = (struct task_list_d*)d;
  assert(s >= p->size);
  (void)s;
  (*cb)(base, &p->next, arg);
}

void udb_walkfunc(void* base, void* warg, uint8_t t, void* d, uint64_t s,
  udb_walk_relptr_cb* cb, void *arg)
{
  (void)warg;
  switch(t) {
  case udb_chunk_type_task:
    udb_task_walk_chunk(base, d, s, cb, arg);
    break;
  default:
    /* no rel ptrs */
    break;
  }
}

struct udb_base* task_file_create(const char* file)
{
	return udb_base_create_new(file, &udb_walkfunc, NULL);
}

static int
task_create_new_elem(struct udb_base* udb, udb_ptr* last, udb_ptr* e,
	size_t sz, const dname_type* zname)
{
	if(!udb_ptr_alloc_space(e, udb, udb_chunk_type_task, sz)) {
		return 0;
	}
	if(udb_ptr_is_null(last)) {
		udb_base_set_userdata(udb, e->data);
	} else {
		udb_rptr_set_ptr(&TASKLIST(last)->next, udb, e);
	}
	udb_ptr_set_ptr(last, udb, e);

	/* fill in tasklist item */
	udb_rel_ptr_init(&TASKLIST(e)->next);
	TASKLIST(e)->size = sz;
	TASKLIST(e)->oldserial = 0;
	TASKLIST(e)->newserial = 0;
	TASKLIST(e)->yesno = 0;

	if(zname) {
		memmove(TASKLIST(e)->zname, zname, dname_total_size(zname));
	}
	return 1;
}

void task_new_soainfo(struct udb_base* udb, udb_ptr* last, struct zone* z,
	enum soainfo_hint hint)
{
	/* calculate size */
	udb_ptr e;
	size_t sz;
	const dname_type* apex, *ns, *em;
	if(!z || !z->apex || !domain_dname(z->apex))
		return; /* safety check */

	DEBUG(DEBUG_IPC,1, (LOG_INFO, "nsd: add soa info for zone %s",
		domain_to_string(z->apex)));
	apex = domain_dname(z->apex);
	sz = sizeof(struct task_list_d) + dname_total_size(apex);
	if(z->soa_rrset && hint == soainfo_ok) {
		ns = domain_dname(rdata_domain_ref(z->soa_rrset->rrs[0]));
		em = domain_dname(rdata_domain_ref_offset(
			z->soa_rrset->rrs[0], sizeof(void*)));
		sz += sizeof(uint32_t)*6 + sizeof(uint8_t)*2
			+ ns->name_size + em->name_size;
	} else {
		ns = NULL;
		em = NULL;
	}

	/* create new task_list item */
	if(!task_create_new_elem(udb, last, &e, sz, apex)) {
		log_msg(LOG_ERR, "tasklist: out of space, cannot add SOAINFO");
		return;
	}
	TASKLIST(&e)->task_type = task_soa_info;
	TASKLIST(&e)->yesno = (uint64_t)hint;

	if(z->soa_rrset && hint == soainfo_ok) {
		uint32_t ttl = htonl(z->soa_rrset->rrs[0]->ttl);
		uint8_t* p = (uint8_t*)TASKLIST(&e)->zname;
		p += dname_total_size(apex);
		memmove(p, &ttl, sizeof(uint32_t));
		p += sizeof(uint32_t);
		memmove(p, &ns->name_size, sizeof(uint8_t));
		p += sizeof(uint8_t);
		memmove(p, dname_name(ns), ns->name_size);
		p += ns->name_size;
		memmove(p, &em->name_size, sizeof(uint8_t));
		p += sizeof(uint8_t);
		memmove(p, dname_name(em), em->name_size);
		p += em->name_size;
		memmove(p, z->soa_rrset->rrs[0]->rdata + sizeof(void*)*2,
			sizeof(uint32_t)*5);
	}
	udb_ptr_unlink(&e, udb);
}

void task_process_sync(struct udb_base* taskudb)
{
	/* need to sync before other process uses the mmap? */
	DEBUG(DEBUG_IPC,1, (LOG_INFO, "task procsync %s size %d",
		taskudb->fname, (int)taskudb->base_size));
	(void)taskudb;
}

void task_remap(struct udb_base* taskudb)
{
	DEBUG(DEBUG_IPC,1, (LOG_INFO, "task remap %s size %d",
		taskudb->fname, (int)taskudb->glob_data->fsize));
	udb_base_remap_process(taskudb);
}

void task_clear(struct udb_base* taskudb)
{
	udb_ptr t, n;
	udb_ptr_new(&t, taskudb, udb_base_get_userdata(taskudb));
	udb_base_set_userdata(taskudb, 0);
	udb_ptr_init(&n, taskudb);
	while(!udb_ptr_is_null(&t)) {
		udb_ptr_set_rptr(&n, taskudb, &TASKLIST(&t)->next);
		udb_rptr_zero(&TASKLIST(&t)->next, taskudb);
		udb_ptr_free_space(&t, taskudb, TASKLIST(&t)->size);
		udb_ptr_set_ptr(&t, taskudb, &n);
	}
	udb_ptr_unlink(&t, taskudb);
	udb_ptr_unlink(&n, taskudb);
}

void task_new_expire(struct udb_base* udb, udb_ptr* last,
	const struct dname* z, int expired)
{
	udb_ptr e;
	if(!z) return;
	DEBUG(DEBUG_IPC,1, (LOG_INFO, "add expire info for zone %s",
		dname_to_string(z,NULL)));
	if(!task_create_new_elem(udb, last, &e, sizeof(struct task_list_d)+
		dname_total_size(z), z)) {
		log_msg(LOG_ERR, "tasklist: out of space, cannot add expire");
		return;
	}
	TASKLIST(&e)->task_type = task_expire;
	TASKLIST(&e)->yesno = expired;
	udb_ptr_unlink(&e, udb);
}

void task_new_check_zonefiles(udb_base* udb, udb_ptr* last,
	const dname_type* zone)
{
	udb_ptr e;
	xfrd_check_catalog_consumer_zonefiles(zone);
	DEBUG(DEBUG_IPC,1, (LOG_INFO, "add task checkzonefiles"));
	if(!task_create_new_elem(udb, last, &e, sizeof(struct task_list_d) +
		(zone?dname_total_size(zone):0), zone)) {
		log_msg(LOG_ERR, "tasklist: out of space, cannot add check_zones");
		return;
	}
	TASKLIST(&e)->task_type = task_check_zonefiles;
	TASKLIST(&e)->yesno = (zone!=NULL);
	udb_ptr_unlink(&e, udb);
}

void task_new_write_zonefiles(udb_base* udb, udb_ptr* last,
	const dname_type* zone)
{
	udb_ptr e;
	DEBUG(DEBUG_IPC,1, (LOG_INFO, "add task writezonefiles"));
	if(!task_create_new_elem(udb, last, &e, sizeof(struct task_list_d) +
		(zone?dname_total_size(zone):0), zone)) {
		log_msg(LOG_ERR, "tasklist: out of space, cannot add writezones");
		return;
	}
	TASKLIST(&e)->task_type = task_write_zonefiles;
	TASKLIST(&e)->yesno = (zone!=NULL);
	udb_ptr_unlink(&e, udb);
}

void task_new_set_verbosity(udb_base* udb, udb_ptr* last, int v)
{
	udb_ptr e;
	DEBUG(DEBUG_IPC,1, (LOG_INFO, "add task set_verbosity"));
	if(!task_create_new_elem(udb, last, &e, sizeof(struct task_list_d),
		NULL)) {
		log_msg(LOG_ERR, "tasklist: out of space, cannot add set_v");
		return;
	}
	TASKLIST(&e)->task_type = task_set_verbosity;
	TASKLIST(&e)->yesno = v;
	udb_ptr_unlink(&e, udb);
}

void
task_new_add_zone(udb_base* udb, udb_ptr* last, const char* zone,
	const char* pattern, unsigned zonestatid)
{
	size_t zlen = strlen(zone);
	size_t plen = strlen(pattern);
	void *p;
	udb_ptr e;
	DEBUG(DEBUG_IPC,1, (LOG_INFO, "add task addzone %s %s", zone, pattern));
	if(!task_create_new_elem(udb, last, &e, sizeof(struct task_list_d)+
		zlen + 1 + plen + 1, NULL)) {
		log_msg(LOG_ERR, "tasklist: out of space, cannot add addz");
		return;
	}
	TASKLIST(&e)->task_type = task_add_zone;
	TASKLIST(&e)->yesno = zonestatid;
	p = TASKLIST(&e)->zname;
	memcpy(p, zone, zlen+1);
	memmove((char*)p+zlen+1, pattern, plen+1);
	udb_ptr_unlink(&e, udb);
}

void
task_new_del_zone(udb_base* udb, udb_ptr* last, const dname_type* dname)
{
	udb_ptr e;
	DEBUG(DEBUG_IPC,1, (LOG_INFO, "add task delzone %s", dname_to_string(dname, 0)));
	if(!task_create_new_elem(udb, last, &e, sizeof(struct task_list_d)
		+dname_total_size(dname), dname)) {
		log_msg(LOG_ERR, "tasklist: out of space, cannot add delz");
		return;
	}
	TASKLIST(&e)->task_type = task_del_zone;
	udb_ptr_unlink(&e, udb);
}

void task_new_add_key(udb_base* udb, udb_ptr* last, struct key_options* key)
{
	char* p;
	udb_ptr e;
	assert(key->name && key->algorithm && key->secret);
	DEBUG(DEBUG_IPC,1, (LOG_INFO, "add task addkey"));
	if(!task_create_new_elem(udb, last, &e, sizeof(struct task_list_d)
		+strlen(key->name)+1+strlen(key->algorithm)+1+
		strlen(key->secret)+1, NULL)) {
		log_msg(LOG_ERR, "tasklist: out of space, cannot add addk");
		return;
	}
	TASKLIST(&e)->task_type = task_add_key;
	p = (char*)TASKLIST(&e)->zname;
	memmove(p, key->name, strlen(key->name)+1);
	p+=strlen(key->name)+1;
	memmove(p, key->algorithm, strlen(key->algorithm)+1);
	p+=strlen(key->algorithm)+1;
	memmove(p, key->secret, strlen(key->secret)+1);
	udb_ptr_unlink(&e, udb);
}

void task_new_del_key(udb_base* udb, udb_ptr* last, const char* name)
{
	char* p;
	udb_ptr e;
	DEBUG(DEBUG_IPC,1, (LOG_INFO, "add task delkey"));
	if(!task_create_new_elem(udb, last, &e, sizeof(struct task_list_d)
		+strlen(name)+1, NULL)) {
		log_msg(LOG_ERR, "tasklist: out of space, cannot add delk");
		return;
	}
	TASKLIST(&e)->task_type = task_del_key;
	p = (char*)TASKLIST(&e)->zname;
	memmove(p, name, strlen(name)+1);
	udb_ptr_unlink(&e, udb);
}

void task_new_cookies(udb_base* udb, udb_ptr* last, int answer_cookie,
		size_t cookie_count, void* cookie_secrets) {
	udb_ptr e;
	char* p;
	size_t const secrets_size = sizeof(cookie_secrets_type);

	DEBUG(DEBUG_IPC, 1, (LOG_INFO, "add task cookies"));

	if(!task_create_new_elem(udb, last, &e,
			sizeof(struct task_list_d) + secrets_size, NULL)) {
		log_msg(LOG_ERR, "tasklist: out of space, cannot add cookies");
		return;
	}
	TASKLIST(&e)->task_type = task_cookies;
	TASKLIST(&e)->newserial = (uint32_t) answer_cookie;
	TASKLIST(&e)->yesno = (uint64_t) cookie_count;
	p = (char*)TASKLIST(&e)->zname;
	memmove(p, cookie_secrets, secrets_size);

	udb_ptr_unlink(&e, udb);
}

void task_new_add_pattern(udb_base* udb, udb_ptr* last,
	struct pattern_options* p)
{
	region_type* temp;
	buffer_type* buffer;
	udb_ptr e;
	DEBUG(DEBUG_IPC,1, (LOG_INFO, "add task addpattern %s", p->pname));
	temp = region_create(xalloc, free);
	buffer = buffer_create(temp, 4096);
	pattern_options_marshal(buffer, p);
	buffer_flip(buffer);
	if(!task_create_new_elem(udb, last, &e, sizeof(struct task_list_d)
		+ buffer_limit(buffer), NULL)) {
		log_msg(LOG_ERR, "tasklist: out of space, cannot add addp");
		region_destroy(temp);
		return;
	}
	TASKLIST(&e)->task_type = task_add_pattern;
	TASKLIST(&e)->yesno = buffer_limit(buffer);
	memmove(TASKLIST(&e)->zname, buffer_begin(buffer),
		buffer_limit(buffer));
	udb_ptr_unlink(&e, udb);
	region_destroy(temp);
}

void task_new_del_pattern(udb_base* udb, udb_ptr* last, const char* name)
{
	char* p;
	udb_ptr e;
	DEBUG(DEBUG_IPC,1, (LOG_INFO, "add task delpattern %s", name));
	if(!task_create_new_elem(udb, last, &e, sizeof(struct task_list_d)
		+strlen(name)+1, NULL)) {
		log_msg(LOG_ERR, "tasklist: out of space, cannot add delp");
		return;
	}
	TASKLIST(&e)->task_type = task_del_pattern;
	p = (char*)TASKLIST(&e)->zname;
	memmove(p, name, strlen(name)+1);
	udb_ptr_unlink(&e, udb);
}

void task_new_opt_change(udb_base* udb, udb_ptr* last, struct nsd_options* opt)
{
	udb_ptr e;
	DEBUG(DEBUG_IPC,1, (LOG_INFO, "add task opt_change"));
	if(!task_create_new_elem(udb, last, &e, sizeof(struct task_list_d),
		NULL)) {
		log_msg(LOG_ERR, "tasklist: out of space, cannot add o_c");
		return;
	}
	TASKLIST(&e)->task_type = task_opt_change;
#ifdef RATELIMIT
	TASKLIST(&e)->oldserial = opt->rrl_ratelimit;
	TASKLIST(&e)->newserial = opt->rrl_whitelist_ratelimit;
	TASKLIST(&e)->yesno = (uint64_t) opt->rrl_slip;
#else
	(void)opt;
#endif
	udb_ptr_unlink(&e, udb);
}

void task_new_zonestat_inc(udb_base* udb, udb_ptr* last, unsigned sz)
{
	udb_ptr e;
	DEBUG(DEBUG_IPC,1, (LOG_INFO, "add task zonestat_inc"));
	if(sz == 0)
		return; /* no need to decrease to 0 */
	if(!task_create_new_elem(udb, last, &e, sizeof(struct task_list_d),
		NULL)) {
		log_msg(LOG_ERR, "tasklist: out of space, cannot add z_i");
		return;
	}
	TASKLIST(&e)->task_type = task_zonestat_inc;
	TASKLIST(&e)->oldserial = (uint32_t)sz;
	udb_ptr_unlink(&e, udb);
}

int
task_new_apply_xfr(udb_base* udb, udb_ptr* last, const dname_type* dname,
	uint32_t old_serial, uint32_t new_serial, uint64_t filenumber)
{
	udb_ptr e;
	DEBUG(DEBUG_IPC,1, (LOG_INFO, "add task apply_xfr"));
	if(!task_create_new_elem(udb, last, &e, sizeof(struct task_list_d)
		+dname_total_size(dname), dname)) {
		log_msg(LOG_ERR, "tasklist: out of space, cannot add applyxfr");
		return 0;
	}
	TASKLIST(&e)->oldserial = old_serial;
	TASKLIST(&e)->newserial = new_serial;
	TASKLIST(&e)->yesno = filenumber;
	TASKLIST(&e)->task_type = task_apply_xfr;
	udb_ptr_unlink(&e, udb);
	return 1;
}

void
task_process_expire(namedb_type* db, struct task_list_d* task)
{
	uint8_t ok;
	zone_type* z = namedb_find_zone(db, task->zname);
	assert(task->task_type == task_expire);
	if(!z) {
		DEBUG(DEBUG_IPC, 1, (LOG_WARNING, "zone %s %s but not in zonetree",
			dname_to_string(task->zname, NULL),
			task->yesno?"expired":"unexpired"));
		return;
	}
	DEBUG(DEBUG_IPC,1, (LOG_INFO, "xfrd: expire task zone %s %s",
		dname_to_string(task->zname,0),
		task->yesno?"expired":"unexpired"));
	/* find zone, set expire flag */
	ok = !task->yesno;
	/* only update zone->is_ok if needed to minimize copy-on-write
	 * of memory pages shared after fork() */
	if(ok && !z->is_ok)
		z->is_ok = 1;
	else if(!ok && z->is_ok)
		z->is_ok = 0;
}

static void
task_process_set_verbosity(struct task_list_d* task)
{
	DEBUG(DEBUG_IPC,1, (LOG_INFO, "verbosity task %d", (int)task->yesno));
	verbosity = task->yesno;
}

static void
task_process_checkzones(struct nsd* nsd, udb_base* taskudb, udb_ptr* last_task,
	struct task_list_d* task)
{
	/* on SIGHUP check if zone-text-files changed and if so,
	 * reread.  When from xfrd-reload, no need to fstat the files */
	if(task->yesno) {
		struct zone_options* zo = zone_options_find(nsd->options,
			task->zname);
		if(zo)
			namedb_check_zonefile(nsd, taskudb, last_task, zo);
	} else {
		/* check all zones */
		namedb_check_zonefiles(nsd, nsd->options, taskudb, last_task);
	}
}

static void
task_process_writezones(struct nsd* nsd, struct task_list_d* task)
{
	if(task->yesno) {
		struct zone_options* zo = zone_options_find(nsd->options,
			task->zname);
		if(zo)
			namedb_write_zonefile(nsd, zo);
	} else {
		namedb_write_zonefiles(nsd, nsd->options);
	}
}

static void
task_process_add_zone(struct nsd* nsd, udb_base* udb, udb_ptr* last_task,
	struct task_list_d* task)
{
	zone_type* z;
	const dname_type* zdname;
	const char* zname = (const char*)task->zname;
	const char* pname = zname + strlen(zname)+1;
	DEBUG(DEBUG_IPC,1, (LOG_INFO, "addzone task %s %s", zname, pname));
	zdname = dname_parse(nsd->db->region, zname);
	if(!zdname) {
		log_msg(LOG_ERR, "can not parse zone name %s", zname);
		return;
	}
	/* create zone */
	z = find_or_create_zone(nsd->db, zdname, nsd->options, zname, pname);
	if(!z) {
		region_recycle(nsd->db->region, (void*)zdname,
			dname_total_size(zdname));
		log_msg(LOG_ERR, "can not add zone %s %s", zname, pname);
		return;
	}
	/* zdname is not used by the zone allocation. */
	region_recycle(nsd->db->region, (void*)zdname,
		dname_total_size(zdname));
	z->zonestatid = (unsigned)task->yesno;
	/* if zone is empty, attempt to read the zonefile from disk (if any) */
	if(!z->soa_rrset && z->opts->pattern->zonefile) {
		namedb_read_zonefile(nsd, z, udb, last_task);
	}
}

static void
task_process_del_zone(struct nsd* nsd, struct task_list_d* task)
{
	zone_type* zone;
	struct zone_options* zopt;
	DEBUG(DEBUG_IPC,1, (LOG_INFO, "delzone task %s", dname_to_string(
		task->zname, NULL)));
	zone = namedb_find_zone(nsd->db, task->zname);
	if(!zone)
		return;

#ifdef NSEC3
	nsec3_clear_precompile(nsd->db, zone);
	zone->nsec3_param = NULL;
#endif
	delete_zone_rrs(nsd->db, zone);

	/* remove from zonetree, apex, soa */
	zopt = zone->opts;
	namedb_zone_delete(nsd->db, zone);
	/* remove from options (zone_list already edited by xfrd) */
	zone_options_delete(nsd->options, zopt);
}

static void
task_process_add_key(struct nsd* nsd, struct task_list_d* task)
{
	struct key_options key;
	key.name = (char*)task->zname;
	DEBUG(DEBUG_IPC,1, (LOG_INFO, "addkey task %s", key.name));
	key.algorithm = key.name + strlen(key.name)+1;
	key.secret = key.algorithm + strlen(key.algorithm)+1;
	key_options_add_modify(nsd->options, &key);
	memset(key.secret, 0xdd, strlen(key.secret)); /* wipe secret */
}

static void
task_process_del_key(struct nsd* nsd, struct task_list_d* task)
{
	char* name = (char*)task->zname;
	DEBUG(DEBUG_IPC,1, (LOG_INFO, "delkey task %s", name));
	/* this is reload and nothing is using the TSIG key right now */
	key_options_remove(nsd->options, name);
}

static void
task_process_cookies(struct nsd* nsd, struct task_list_d* task) {
	DEBUG(DEBUG_IPC, 1, (LOG_INFO, "cookies task answer: %s, count: %d",
		task->newserial ? "yes" : "no", (int)task->yesno));
	
	nsd->do_answer_cookie = (int) task->newserial;
	nsd->cookie_count = (size_t) task->yesno;
	memmove(nsd->cookie_secrets, task->zname, sizeof(nsd->cookie_secrets));
	explicit_bzero(task->zname, sizeof(nsd->cookie_secrets));
}

static void
task_process_add_pattern(struct nsd* nsd, struct task_list_d* task)
{
	region_type* temp = region_create(xalloc, free);
	buffer_type buffer;
	struct pattern_options *pat;
	buffer_create_from(&buffer, task->zname, task->yesno);
	pat = pattern_options_unmarshal(temp, &buffer);
	DEBUG(DEBUG_IPC,1, (LOG_INFO, "addpattern task %s", pat->pname));
	pattern_options_add_modify(nsd->options, pat);
	region_destroy(temp);
}

static void
task_process_del_pattern(struct nsd* nsd, struct task_list_d* task)
{
	char* name = (char*)task->zname;
	DEBUG(DEBUG_IPC,1, (LOG_INFO, "delpattern task %s", name));
	pattern_options_remove(nsd->options, name);
}

static void
task_process_opt_change(struct nsd* nsd, struct task_list_d* task)
{
	DEBUG(DEBUG_IPC,1, (LOG_INFO, "optchange task"));
#ifdef RATELIMIT
	nsd->options->rrl_ratelimit = task->oldserial;
	nsd->options->rrl_whitelist_ratelimit = task->newserial;
	nsd->options->rrl_slip = task->yesno;
	rrl_set_limit(nsd->options->rrl_ratelimit, nsd->options->rrl_whitelist_ratelimit,
		nsd->options->rrl_slip);
#else
	(void)nsd; (void)task;
#endif
}

#ifdef USE_ZONE_STATS
static void
task_process_zonestat_inc(struct nsd* nsd, udb_base* udb, udb_ptr *last_task,
	struct task_list_d* task)
{
	DEBUG(DEBUG_IPC,1, (LOG_INFO, "zonestat_inc task %u", (unsigned)task->oldserial));
	nsd->zonestatdesired = (unsigned)task->oldserial;
	/* send echo to xfrd to increment on its end */
	task_new_zonestat_inc(udb, last_task, nsd->zonestatdesired);
}
#endif

void
task_process_apply_xfr(struct nsd* nsd, udb_base* udb, udb_ptr* task)
{
	/* we have to use an udb_ptr task here, because the apply_xfr procedure
	 * appends soa_info which may remap and change the pointer. */
	zone_type* zone;
	FILE* df;
	DEBUG(DEBUG_IPC,1, (LOG_INFO, "applyxfr task %s", dname_to_string(
		TASKLIST(task)->zname, NULL)));
	zone = namedb_find_zone(nsd->db, TASKLIST(task)->zname);
	if(!zone) {
		/* assume the zone has been deleted and a zone transfer was
		 * still waiting to be processed */
		udb_ptr_free_space(task, udb, TASKLIST(task)->size);
		return;
	}

	/* apply the XFR */
	/* oldserial, newserial, yesno is filenumber */
	df = xfrd_open_xfrfile(nsd, TASKLIST(task)->yesno, "r");
	if(!df) {
		/* could not open file to update */
		/* soainfo_gone will be communicated from server_reload, unless
		   preceding updates have been applied */
		zone->is_skipped = 1;
		udb_ptr_free_space(task, udb, TASKLIST(task)->size);
		return;
	}
	/* read and apply zone transfer */
	switch(apply_ixfr_for_zone(nsd, zone, df, nsd->options, udb,
				TASKLIST(task)->yesno)) {
	case 1: /* Success */
		break;

	case 0: /* Failure */
		/* soainfo_gone will be communicated from server_reload, unless
		   preceding updates have been applied  */
		zone->is_skipped = 1;
		break;

	case -1:/* Fatal */
		exit(1);
		break;

	default:break;
	}
	fclose(df);
	udb_ptr_free_space(task, udb, TASKLIST(task)->size);
}


void task_process_in_reload(struct nsd* nsd, udb_base* udb, udb_ptr *last_task,
        udb_ptr* task)
{
	switch(TASKLIST(task)->task_type) {
	case task_expire:
		task_process_expire(nsd->db, TASKLIST(task));
		break;
	case task_check_zonefiles:
		task_process_checkzones(nsd, udb, last_task, TASKLIST(task));
		break;
	case task_write_zonefiles:
		task_process_writezones(nsd, TASKLIST(task));
		break;
	case task_set_verbosity:
		task_process_set_verbosity(TASKLIST(task));
		break;
	case task_add_zone:
		task_process_add_zone(nsd, udb, last_task, TASKLIST(task));
		break;
	case task_del_zone:
		task_process_del_zone(nsd, TASKLIST(task));
		break;
	case task_add_key:
		task_process_add_key(nsd, TASKLIST(task));
		break;
	case task_del_key:
		task_process_del_key(nsd, TASKLIST(task));
		break;
	case task_add_pattern:
		task_process_add_pattern(nsd, TASKLIST(task));
		break;
	case task_del_pattern:
		task_process_del_pattern(nsd, TASKLIST(task));
		break;
	case task_opt_change:
		task_process_opt_change(nsd, TASKLIST(task));
		break;
#ifdef USE_ZONE_STATS
	case task_zonestat_inc:
		task_process_zonestat_inc(nsd, udb, last_task, TASKLIST(task));
		break;
#endif
	case task_cookies:
		task_process_cookies(nsd, TASKLIST(task));
		break;
	default:
		log_msg(LOG_WARNING, "unhandled task in reload type %d",
			(int)TASKLIST(task)->task_type);
		break;
	}
	udb_ptr_free_space(task, udb, TASKLIST(task)->size);
}