- Fix for windows compile create ssl contexts.

[thirdparty/unbound.git] / services / authzone.c

/*
 * services/authzone.c - authoritative zone that is locally hosted.
 *
 * Copyright (c) 2017, NLnet Labs. All rights reserved.
 *
 * This software is open source.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 
 * Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 * 
 * Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 * 
 * Neither the name of the NLNET LABS nor the names of its contributors may
 * be used to endorse or promote products derived from this software without
 * specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/**
 * \file
 *
 * This file contains the functions for an authority zone.  This zone
 * is queried by the iterator, just like a stub or forward zone, but then
 * the data is locally held.
 */

#include "config.h"
#include "services/authzone.h"
#include "util/data/dname.h"
#include "util/data/msgparse.h"
#include "util/data/msgreply.h"
#include "util/data/msgencode.h"
#include "util/data/packed_rrset.h"
#include "util/regional.h"
#include "util/net_help.h"
#include "util/netevent.h"
#include "util/config_file.h"
#include "util/log.h"
#include "util/module.h"
#include "util/random.h"
#include "services/cache/dns.h"
#include "services/outside_network.h"
#include "services/listen_dnsport.h"
#include "services/mesh.h"
#include "sldns/rrdef.h"
#include "sldns/pkthdr.h"
#include "sldns/sbuffer.h"
#include "sldns/str2wire.h"
#include "sldns/wire2str.h"
#include "sldns/parseutil.h"
#include "sldns/keyraw.h"
#include "validator/val_nsec3.h"
#include "validator/val_nsec.h"
#include "validator/val_secalgo.h"
#include "validator/val_sigcrypt.h"
#include "validator/val_anchor.h"
#include "validator/val_utils.h"
#include <ctype.h>

/** bytes to use for NSEC3 hash buffer. 20 for sha1 */
#define N3HASHBUFLEN 32
/** max number of CNAMEs we are willing to follow (in one answer) */
#define MAX_CNAME_CHAIN 8
/** timeout for probe packets for SOA */
#define AUTH_PROBE_TIMEOUT 100 /* msec */
/** when to stop with SOA probes (when exponential timeouts exceed this) */
#define AUTH_PROBE_TIMEOUT_STOP 1000 /* msec */
/* auth transfer timeout for TCP connections, in msec */
#define AUTH_TRANSFER_TIMEOUT 10000 /* msec */
/* auth transfer max backoff for failed transfers and probes */
#define AUTH_TRANSFER_MAX_BACKOFF 86400 /* sec */
/* auth http port number */
#define AUTH_HTTP_PORT 80
/* auth https port number */
#define AUTH_HTTPS_PORT 443
/* max depth for nested $INCLUDEs */
#define MAX_INCLUDE_DEPTH 10
/** number of timeouts before we fallback from IXFR to AXFR,
 * because some versions of servers (eg. dnsmasq) drop IXFR packets. */
#define NUM_TIMEOUTS_FALLBACK_IXFR 3

/** pick up nextprobe task to start waiting to perform transfer actions */
static void xfr_set_timeout(struct auth_xfer* xfr, struct module_env* env,
        int failure, int lookup_only);
/** move to sending the probe packets, next if fails. task_probe */
static void xfr_probe_send_or_end(struct auth_xfer* xfr,
        struct module_env* env);
/** pick up probe task with specified(or NULL) destination first,
 * or transfer task if nothing to probe, or false if already in progress */
static int xfr_start_probe(struct auth_xfer* xfr, struct module_env* env,
        struct auth_master* spec);
/** delete xfer structure (not its tree entry) */
void auth_xfer_delete(struct auth_xfer* xfr);

/** create new dns_msg */
static struct dns_msg*
msg_create(struct regional* region, struct query_info* qinfo)
{
        struct dns_msg* msg = (struct dns_msg*)regional_alloc(region,
                sizeof(struct dns_msg));
        if(!msg)
                return NULL;
        msg->qinfo.qname = regional_alloc_init(region, qinfo->qname,
                qinfo->qname_len);
        if(!msg->qinfo.qname)
                return NULL;
        msg->qinfo.qname_len = qinfo->qname_len;
        msg->qinfo.qtype = qinfo->qtype;
        msg->qinfo.qclass = qinfo->qclass;
        msg->qinfo.local_alias = NULL;
        /* non-packed reply_info, because it needs to grow the array */
        msg->rep = (struct reply_info*)regional_alloc_zero(region,
                sizeof(struct reply_info)-sizeof(struct rrset_ref));
        if(!msg->rep)
                return NULL;
        msg->rep->flags = (uint16_t)(BIT_QR | BIT_AA);
        msg->rep->authoritative = 1;
        msg->rep->reason_bogus = LDNS_EDE_NONE;
        msg->rep->qdcount = 1;
        /* rrsets is NULL, no rrsets yet */
        return msg;
}

/** grow rrset array by one in msg */
static int
msg_grow_array(struct regional* region, struct dns_msg* msg)
{
        if(msg->rep->rrsets == NULL) {
                msg->rep->rrsets = regional_alloc_zero(region,
                        sizeof(struct ub_packed_rrset_key*)*(msg->rep->rrset_count+1));
                if(!msg->rep->rrsets)
                        return 0;
        } else {
                struct ub_packed_rrset_key** rrsets_old = msg->rep->rrsets;
                msg->rep->rrsets = regional_alloc_zero(region,
                        sizeof(struct ub_packed_rrset_key*)*(msg->rep->rrset_count+1));
                if(!msg->rep->rrsets)
                        return 0;
                memmove(msg->rep->rrsets, rrsets_old,
                        sizeof(struct ub_packed_rrset_key*)*msg->rep->rrset_count);
        }
        return 1;
}

/** get ttl of rrset */
static time_t
get_rrset_ttl(struct ub_packed_rrset_key* k)
{
        struct packed_rrset_data* d = (struct packed_rrset_data*)
                k->entry.data;
        return d->ttl;
}

/** Copy rrset into region from domain-datanode and packet rrset */
static struct ub_packed_rrset_key*
auth_packed_rrset_copy_region(struct auth_zone* z, struct auth_data* node,
        struct auth_rrset* rrset, struct regional* region, time_t adjust)
{
        struct ub_packed_rrset_key key;
        memset(&key, 0, sizeof(key));
        key.entry.key = &key;
        key.entry.data = rrset->data;
        key.rk.dname = node->name;
        key.rk.dname_len = node->namelen;
        key.rk.type = htons(rrset->type);
        key.rk.rrset_class = htons(z->dclass);
        key.entry.hash = rrset_key_hash(&key.rk);
        return packed_rrset_copy_region(&key, region, adjust);
}

/** fix up msg->rep TTL and prefetch ttl */
static void
msg_ttl(struct dns_msg* msg)
{
        if(msg->rep->rrset_count == 0) return;
        if(msg->rep->rrset_count == 1) {
                msg->rep->ttl = get_rrset_ttl(msg->rep->rrsets[0]);
                msg->rep->prefetch_ttl = PREFETCH_TTL_CALC(msg->rep->ttl);
                msg->rep->serve_expired_ttl = msg->rep->ttl + SERVE_EXPIRED_TTL;
        } else if(get_rrset_ttl(msg->rep->rrsets[msg->rep->rrset_count-1]) <
                msg->rep->ttl) {
                msg->rep->ttl = get_rrset_ttl(msg->rep->rrsets[
                        msg->rep->rrset_count-1]);
                msg->rep->prefetch_ttl = PREFETCH_TTL_CALC(msg->rep->ttl);
                msg->rep->serve_expired_ttl = msg->rep->ttl + SERVE_EXPIRED_TTL;
        }
}

/** see if rrset is a duplicate in the answer message */
static int
msg_rrset_duplicate(struct dns_msg* msg, uint8_t* nm, size_t nmlen,
        uint16_t type, uint16_t dclass)
{
        size_t i;
        for(i=0; i<msg->rep->rrset_count; i++) {
                struct ub_packed_rrset_key* k = msg->rep->rrsets[i];
                if(ntohs(k->rk.type) == type && k->rk.dname_len == nmlen &&
                        ntohs(k->rk.rrset_class) == dclass &&
                        query_dname_compare(k->rk.dname, nm) == 0)
                        return 1;
        }
        return 0;
}

/** add rrset to answer section (no auth, add rrsets yet) */
static int
msg_add_rrset_an(struct auth_zone* z, struct regional* region,
        struct dns_msg* msg, struct auth_data* node, struct auth_rrset* rrset)
{
        log_assert(msg->rep->ns_numrrsets == 0);
        log_assert(msg->rep->ar_numrrsets == 0);
        if(!rrset || !node)
                return 1;
        if(msg_rrset_duplicate(msg, node->name, node->namelen, rrset->type,
                z->dclass))
                return 1;
        /* grow array */
        if(!msg_grow_array(region, msg))
                return 0;
        /* copy it */
        if(!(msg->rep->rrsets[msg->rep->rrset_count] =
                auth_packed_rrset_copy_region(z, node, rrset, region, 0)))
                return 0;
        msg->rep->rrset_count++;
        msg->rep->an_numrrsets++;
        msg_ttl(msg);
        return 1;
}

/** add rrset to authority section (no additional section rrsets yet) */
static int
msg_add_rrset_ns(struct auth_zone* z, struct regional* region,
        struct dns_msg* msg, struct auth_data* node, struct auth_rrset* rrset)
{
        log_assert(msg->rep->ar_numrrsets == 0);
        if(!rrset || !node)
                return 1;
        if(msg_rrset_duplicate(msg, node->name, node->namelen, rrset->type,
                z->dclass))
                return 1;
        /* grow array */
        if(!msg_grow_array(region, msg))
                return 0;
        /* copy it */
        if(!(msg->rep->rrsets[msg->rep->rrset_count] =
                auth_packed_rrset_copy_region(z, node, rrset, region, 0)))
                return 0;
        msg->rep->rrset_count++;
        msg->rep->ns_numrrsets++;
        msg_ttl(msg);
        return 1;
}

/** add rrset to additional section */
static int
msg_add_rrset_ar(struct auth_zone* z, struct regional* region,
        struct dns_msg* msg, struct auth_data* node, struct auth_rrset* rrset)
{
        if(!rrset || !node)
                return 1;
        if(msg_rrset_duplicate(msg, node->name, node->namelen, rrset->type,
                z->dclass))
                return 1;
        /* grow array */
        if(!msg_grow_array(region, msg))
                return 0;
        /* copy it */
        if(!(msg->rep->rrsets[msg->rep->rrset_count] =
                auth_packed_rrset_copy_region(z, node, rrset, region, 0)))
                return 0;
        msg->rep->rrset_count++;
        msg->rep->ar_numrrsets++;
        msg_ttl(msg);
        return 1;
}

struct auth_zones* auth_zones_create(void)
{
        struct auth_zones* az = (struct auth_zones*)calloc(1, sizeof(*az));
        if(!az) {
                log_err("out of memory");
                return NULL;
        }
        rbtree_init(&az->ztree, &auth_zone_cmp);
        rbtree_init(&az->xtree, &auth_xfer_cmp);
        lock_rw_init(&az->lock);
        lock_protect(&az->lock, &az->ztree, sizeof(az->ztree));
        lock_protect(&az->lock, &az->xtree, sizeof(az->xtree));
        /* also lock protects the rbnode's in struct auth_zone, auth_xfer */
        lock_rw_init(&az->rpz_lock);
        lock_protect(&az->rpz_lock, &az->rpz_first, sizeof(az->rpz_first));
        return az;
}

int auth_zone_cmp(const void* z1, const void* z2)
{
        /* first sort on class, so that hierarchy can be maintained within
         * a class */
        struct auth_zone* a = (struct auth_zone*)z1;
        struct auth_zone* b = (struct auth_zone*)z2;
        int m;
        if(a->dclass != b->dclass) {
                if(a->dclass < b->dclass)
                        return -1;
                return 1;
        }
        /* sorted such that higher zones sort before lower zones (their
         * contents) */
        return dname_lab_cmp(a->name, a->namelabs, b->name, b->namelabs, &m);
}

int auth_data_cmp(const void* z1, const void* z2)
{
        struct auth_data* a = (struct auth_data*)z1;
        struct auth_data* b = (struct auth_data*)z2;
        int m;
        /* canonical sort, because DNSSEC needs that */
        return dname_canon_lab_cmp(a->name, a->namelabs, b->name,
                b->namelabs, &m);
}

int auth_xfer_cmp(const void* z1, const void* z2)
{
        /* first sort on class, so that hierarchy can be maintained within
         * a class */
        struct auth_xfer* a = (struct auth_xfer*)z1;
        struct auth_xfer* b = (struct auth_xfer*)z2;
        int m;
        if(a->dclass != b->dclass) {
                if(a->dclass < b->dclass)
                        return -1;
                return 1;
        }
        /* sorted such that higher zones sort before lower zones (their
         * contents) */
        return dname_lab_cmp(a->name, a->namelabs, b->name, b->namelabs, &m);
}

/** delete auth rrset node */
static void
auth_rrset_delete(struct auth_rrset* rrset)
{
        if(!rrset) return;
        free(rrset->data);
        free(rrset);
}

/** delete auth data domain node */
static void
auth_data_delete(struct auth_data* n)
{
        struct auth_rrset* p, *np;
        if(!n) return;
        p = n->rrsets;
        while(p) {
                np = p->next;
                auth_rrset_delete(p);
                p = np;
        }
        free(n->name);
        free(n);
}

/** helper traverse to delete zones */
static void
auth_data_del(rbnode_type* n, void* ATTR_UNUSED(arg))
{
        struct auth_data* z = (struct auth_data*)n->key;
        auth_data_delete(z);
}

/** delete an auth zone structure (tree remove must be done elsewhere) */
static void
auth_zone_delete(struct auth_zone* z, struct auth_zones* az)
{
        if(!z) return;
        lock_rw_destroy(&z->lock);
        traverse_postorder(&z->data, auth_data_del, NULL);

        if(az && z->rpz) {
                /* keep RPZ linked list intact */
                lock_rw_wrlock(&az->rpz_lock);
                if(z->rpz_az_prev)
                        z->rpz_az_prev->rpz_az_next = z->rpz_az_next;
                else
                        az->rpz_first = z->rpz_az_next;
                if(z->rpz_az_next)
                        z->rpz_az_next->rpz_az_prev = z->rpz_az_prev;
                lock_rw_unlock(&az->rpz_lock);
        }
        if(z->rpz)
                rpz_delete(z->rpz);
        free(z->name);
        free(z->zonefile);
        free(z);
}

struct auth_zone*
auth_zone_create(struct auth_zones* az, uint8_t* nm, size_t nmlen,
        uint16_t dclass)
{
        struct auth_zone* z = (struct auth_zone*)calloc(1, sizeof(*z));
        if(!z) {
                return NULL;
        }
        z->node.key = z;
        z->dclass = dclass;
        z->namelen = nmlen;
        z->namelabs = dname_count_labels(nm);
        z->name = memdup(nm, nmlen);
        if(!z->name) {
                free(z);
                return NULL;
        }
        rbtree_init(&z->data, &auth_data_cmp);
        lock_rw_init(&z->lock);
        lock_protect(&z->lock, &z->name, sizeof(*z)-sizeof(rbnode_type)-
                        sizeof(&z->rpz_az_next)-sizeof(&z->rpz_az_prev));
        lock_rw_wrlock(&z->lock);
        /* z lock protects all, except rbtree itself and the rpz linked list
         * pointers, which are protected using az->lock */
        if(!rbtree_insert(&az->ztree, &z->node)) {
                lock_rw_unlock(&z->lock);
                auth_zone_delete(z, NULL);
                log_warn("duplicate auth zone");
                return NULL;
        }
        return z;
}

struct auth_zone*
auth_zone_find(struct auth_zones* az, uint8_t* nm, size_t nmlen,
        uint16_t dclass)
{
        struct auth_zone key;
        key.node.key = &key;
        key.dclass = dclass;
        key.name = nm;
        key.namelen = nmlen;
        key.namelabs = dname_count_labels(nm);
        return (struct auth_zone*)rbtree_search(&az->ztree, &key);
}

struct auth_xfer*
auth_xfer_find(struct auth_zones* az, uint8_t* nm, size_t nmlen,
        uint16_t dclass)
{
        struct auth_xfer key;
        key.node.key = &key;
        key.dclass = dclass;
        key.name = nm;
        key.namelen = nmlen;
        key.namelabs = dname_count_labels(nm);
        return (struct auth_xfer*)rbtree_search(&az->xtree, &key);
}

/** find an auth zone or sorted less-or-equal, return true if exact */
static int
auth_zone_find_less_equal(struct auth_zones* az, uint8_t* nm, size_t nmlen,
        uint16_t dclass, struct auth_zone** z)
{
        struct auth_zone key;
        key.node.key = &key;
        key.dclass = dclass;
        key.name = nm;
        key.namelen = nmlen;
        key.namelabs = dname_count_labels(nm);
        return rbtree_find_less_equal(&az->ztree, &key, (rbnode_type**)z);
}


/** find the auth zone that is above the given name */
struct auth_zone*
auth_zones_find_zone(struct auth_zones* az, uint8_t* name, size_t name_len,
        uint16_t dclass)
{
        uint8_t* nm = name;
        size_t nmlen = name_len;
        struct auth_zone* z;
        if(auth_zone_find_less_equal(az, nm, nmlen, dclass, &z)) {
                /* exact match */
                return z;
        } else {
                /* less-or-nothing */
                if(!z) return NULL; /* nothing smaller, nothing above it */
                /* we found smaller name; smaller may be above the name,
                 * but not below it. */
                nm = dname_get_shared_topdomain(z->name, name);
                dname_count_size_labels(nm, &nmlen);
                z = NULL;
        }

        /* search up */
        while(!z) {
                z = auth_zone_find(az, nm, nmlen, dclass);
                if(z) return z;
                if(dname_is_root(nm)) break;
                dname_remove_label(&nm, &nmlen);
        }
        return NULL;
}

/** find or create zone with name str. caller must have lock on az. 
 * returns a wrlocked zone */
static struct auth_zone*
auth_zones_find_or_add_zone(struct auth_zones* az, char* name)
{
        uint8_t nm[LDNS_MAX_DOMAINLEN+1];
        size_t nmlen = sizeof(nm);
        struct auth_zone* z;

        if(sldns_str2wire_dname_buf(name, nm, &nmlen) != 0) {
                log_err("cannot parse auth zone name: %s", name);
                return 0;
        }
        z = auth_zone_find(az, nm, nmlen, LDNS_RR_CLASS_IN);
        if(!z) {
                /* not found, create the zone */
                z = auth_zone_create(az, nm, nmlen, LDNS_RR_CLASS_IN);
        } else {
                lock_rw_wrlock(&z->lock);
        }
        return z;
}

/** find or create xfer zone with name str. caller must have lock on az. 
 * returns a locked xfer */
static struct auth_xfer*
auth_zones_find_or_add_xfer(struct auth_zones* az, struct auth_zone* z)
{
        struct auth_xfer* x;
        x = auth_xfer_find(az, z->name, z->namelen, z->dclass);
        if(!x) {
                /* not found, create the zone */
                x = auth_xfer_create(az, z);
        } else {
                lock_basic_lock(&x->lock);
        }
        return x;
}

int
auth_zone_set_zonefile(struct auth_zone* z, char* zonefile)
{
        if(z->zonefile) free(z->zonefile);
        if(zonefile == NULL) {
                z->zonefile = NULL;
        } else {
                z->zonefile = strdup(zonefile);
                if(!z->zonefile) {
                        log_err("malloc failure");
                        return 0;
                }
        }
        return 1;
}

/** set auth zone fallback. caller must have lock on zone */
int
auth_zone_set_fallback(struct auth_zone* z, char* fallbackstr)
{
        if(strcmp(fallbackstr, "yes") != 0 && strcmp(fallbackstr, "no") != 0){
                log_err("auth zone fallback, expected yes or no, got %s",
                        fallbackstr);
                return 0;
        }
        z->fallback_enabled = (strcmp(fallbackstr, "yes")==0);
        return 1;
}

/** create domain with the given name */
static struct auth_data*
az_domain_create(struct auth_zone* z, uint8_t* nm, size_t nmlen)
{
        struct auth_data* n = (struct auth_data*)malloc(sizeof(*n));
        if(!n) return NULL;
        memset(n, 0, sizeof(*n));
        n->node.key = n;
        n->name = memdup(nm, nmlen);
        if(!n->name) {
                free(n);
                return NULL;
        }
        n->namelen = nmlen;
        n->namelabs = dname_count_labels(nm);
        if(!rbtree_insert(&z->data, &n->node)) {
                log_warn("duplicate auth domain name");
                free(n->name);
                free(n);
                return NULL;
        }
        return n;
}

/** find domain with exactly the given name */
static struct auth_data*
az_find_name(struct auth_zone* z, uint8_t* nm, size_t nmlen)
{
        struct auth_zone key;
        key.node.key = &key;
        key.name = nm;
        key.namelen = nmlen;
        key.namelabs = dname_count_labels(nm);
        return (struct auth_data*)rbtree_search(&z->data, &key);
}

/** Find domain name (or closest match) */
static void
az_find_domain(struct auth_zone* z, struct query_info* qinfo, int* node_exact,
        struct auth_data** node)
{
        struct auth_zone key;
        key.node.key = &key;
        key.name = qinfo->qname;
        key.namelen = qinfo->qname_len;
        key.namelabs = dname_count_labels(key.name);
        *node_exact = rbtree_find_less_equal(&z->data, &key,
                (rbnode_type**)node);
}

/** find or create domain with name in zone */
static struct auth_data*
az_domain_find_or_create(struct auth_zone* z, uint8_t* dname,
        size_t dname_len)
{
        struct auth_data* n = az_find_name(z, dname, dname_len);
        if(!n) {
                n = az_domain_create(z, dname, dname_len);
        }
        return n;
}

/** find rrset of given type in the domain */
static struct auth_rrset*
az_domain_rrset(struct auth_data* n, uint16_t t)
{
        struct auth_rrset* rrset;
        if(!n) return NULL;
        rrset = n->rrsets;
        while(rrset) {
                if(rrset->type == t)
                        return rrset;
                rrset = rrset->next;
        }
        return NULL;
}

/** remove rrset of this type from domain */
static void
domain_remove_rrset(struct auth_data* node, uint16_t rr_type)
{
        struct auth_rrset* rrset, *prev;
        if(!node) return;
        prev = NULL;
        rrset = node->rrsets;
        while(rrset) {
                if(rrset->type == rr_type) {
                        /* found it, now delete it */
                        if(prev) prev->next = rrset->next;
                        else    node->rrsets = rrset->next;
                        auth_rrset_delete(rrset);
                        return;
                }
                prev = rrset;
                rrset = rrset->next;
        }
}

/** find an rrsig index in the rrset.  returns true if found */
static int
az_rrset_find_rrsig(struct packed_rrset_data* d, uint8_t* rdata, size_t len,
        size_t* index)
{
        size_t i;
        for(i=d->count; i<d->count + d->rrsig_count; i++) {
                if(d->rr_len[i] != len)
                        continue;
                if(memcmp(d->rr_data[i], rdata, len) == 0) {
                        *index = i;
                        return 1;
                }
        }
        return 0;
}

/** see if rdata is duplicate */
static int
rdata_duplicate(struct packed_rrset_data* d, uint8_t* rdata, size_t len)
{
        size_t i;
        for(i=0; i<d->count + d->rrsig_count; i++) {
                if(d->rr_len[i] != len)
                        continue;
                if(memcmp(d->rr_data[i], rdata, len) == 0)
                        return 1;
        }
        return 0;
}

/** get rrsig type covered from rdata.
 * @param rdata: rdata in wireformat, starting with 16bit rdlength.
 * @param rdatalen: length of rdata buffer.
 * @return type covered (or 0).
 */
static uint16_t
rrsig_rdata_get_type_covered(uint8_t* rdata, size_t rdatalen)
{
        if(rdatalen < 4)
                return 0;
        return sldns_read_uint16(rdata+2);
}

/** remove RR from existing RRset. Also sig, if it is a signature.
 * reallocates the packed rrset for a new one, false on alloc failure */
static int
rrset_remove_rr(struct auth_rrset* rrset, size_t index)
{
        struct packed_rrset_data* d, *old = rrset->data;
        size_t i;
        if(index >= old->count + old->rrsig_count)
                return 0; /* index out of bounds */
        d = (struct packed_rrset_data*)calloc(1, packed_rrset_sizeof(old) - (
                sizeof(size_t) + sizeof(uint8_t*) + sizeof(time_t) +
                old->rr_len[index]));
        if(!d) {
                log_err("malloc failure");
                return 0;
        }
        d->ttl = old->ttl;
        d->count = old->count;
        d->rrsig_count = old->rrsig_count;
        if(index < d->count) d->count--;
        else d->rrsig_count--;
        d->trust = old->trust;
        d->security = old->security;

        /* set rr_len, needed for ptr_fixup */
        d->rr_len = (size_t*)((uint8_t*)d +
                sizeof(struct packed_rrset_data));
        if(index > 0)
                memmove(d->rr_len, old->rr_len, (index)*sizeof(size_t));
        if(index+1 < old->count+old->rrsig_count)
                memmove(&d->rr_len[index], &old->rr_len[index+1],
                (old->count+old->rrsig_count - (index+1))*sizeof(size_t));
        packed_rrset_ptr_fixup(d);

        /* move over ttls */
        if(index > 0)
                memmove(d->rr_ttl, old->rr_ttl, (index)*sizeof(time_t));
        if(index+1 < old->count+old->rrsig_count)
                memmove(&d->rr_ttl[index], &old->rr_ttl[index+1],
                (old->count+old->rrsig_count - (index+1))*sizeof(time_t));
        
        /* move over rr_data */
        for(i=0; i<d->count+d->rrsig_count; i++) {
                size_t oldi;
                if(i < index) oldi = i;
                else oldi = i+1;
                memmove(d->rr_data[i], old->rr_data[oldi], d->rr_len[i]);
        }

        /* recalc ttl (lowest of remaining RR ttls) */
        if(d->count + d->rrsig_count > 0)
                d->ttl = d->rr_ttl[0];
        for(i=0; i<d->count+d->rrsig_count; i++) {
                if(d->rr_ttl[i] < d->ttl)
                        d->ttl = d->rr_ttl[i];
        }

        free(rrset->data);
        rrset->data = d;
        return 1;
}

/** add RR to existing RRset. If insert_sig is true, add to rrsigs. 
 * This reallocates the packed rrset for a new one */
static int
rrset_add_rr(struct auth_rrset* rrset, uint32_t rr_ttl, uint8_t* rdata,
        size_t rdatalen, int insert_sig)
{
        struct packed_rrset_data* d, *old = rrset->data;
        size_t total, old_total;

        d = (struct packed_rrset_data*)calloc(1, packed_rrset_sizeof(old)
                + sizeof(size_t) + sizeof(uint8_t*) + sizeof(time_t)
                + rdatalen);
        if(!d) {
                log_err("out of memory");
                return 0;
        }
        /* copy base values */
        memcpy(d, old, sizeof(struct packed_rrset_data));
        if(!insert_sig) {
                d->count++;
        } else {
                d->rrsig_count++;
        }
        old_total = old->count + old->rrsig_count;
        total = d->count + d->rrsig_count;
        /* set rr_len, needed for ptr_fixup */
        d->rr_len = (size_t*)((uint8_t*)d +
                sizeof(struct packed_rrset_data));
        if(old->count != 0)
                memmove(d->rr_len, old->rr_len, old->count*sizeof(size_t));
        if(old->rrsig_count != 0)
                memmove(d->rr_len+d->count, old->rr_len+old->count,
                        old->rrsig_count*sizeof(size_t));
        if(!insert_sig)
                d->rr_len[d->count-1] = rdatalen;
        else    d->rr_len[total-1] = rdatalen;
        packed_rrset_ptr_fixup(d);
        if((time_t)rr_ttl < d->ttl)
                d->ttl = rr_ttl;

        /* copy old values into new array */
        if(old->count != 0) {
                memmove(d->rr_ttl, old->rr_ttl, old->count*sizeof(time_t));
                /* all the old rr pieces are allocated sequential, so we
                 * can copy them in one go */
                memmove(d->rr_data[0], old->rr_data[0],
                        (old->rr_data[old->count-1] - old->rr_data[0]) +
                        old->rr_len[old->count-1]);
        }
        if(old->rrsig_count != 0) {
                memmove(d->rr_ttl+d->count, old->rr_ttl+old->count,
                        old->rrsig_count*sizeof(time_t));
                memmove(d->rr_data[d->count], old->rr_data[old->count],
                        (old->rr_data[old_total-1] - old->rr_data[old->count]) +
                        old->rr_len[old_total-1]);
        }

        /* insert new value */
        if(!insert_sig) {
                d->rr_ttl[d->count-1] = rr_ttl;
                memmove(d->rr_data[d->count-1], rdata, rdatalen);
        } else {
                d->rr_ttl[total-1] = rr_ttl;
                memmove(d->rr_data[total-1], rdata, rdatalen);
        }

        rrset->data = d;
        free(old);
        return 1;
}

/** Create new rrset for node with packed rrset with one RR element */
static struct auth_rrset*
rrset_create(struct auth_data* node, uint16_t rr_type, uint32_t rr_ttl,
        uint8_t* rdata, size_t rdatalen)
{
        struct auth_rrset* rrset = (struct auth_rrset*)calloc(1,
                sizeof(*rrset));
        struct auth_rrset* p, *prev;
        struct packed_rrset_data* d;
        if(!rrset) {
                log_err("out of memory");
                return NULL;
        }
        rrset->type = rr_type;

        /* the rrset data structure, with one RR */
        d = (struct packed_rrset_data*)calloc(1,
                sizeof(struct packed_rrset_data) + sizeof(size_t) +
                sizeof(uint8_t*) + sizeof(time_t) + rdatalen);
        if(!d) {
                free(rrset);
                log_err("out of memory");
                return NULL;
        }
        rrset->data = d;
        d->ttl = rr_ttl;
        d->trust = rrset_trust_prim_noglue;
        d->rr_len = (size_t*)((uint8_t*)d + sizeof(struct packed_rrset_data));
        d->rr_data = (uint8_t**)&(d->rr_len[1]);
        d->rr_ttl = (time_t*)&(d->rr_data[1]);
        d->rr_data[0] = (uint8_t*)&(d->rr_ttl[1]);

        /* insert the RR */
        d->rr_len[0] = rdatalen;
        d->rr_ttl[0] = rr_ttl;
        memmove(d->rr_data[0], rdata, rdatalen);
        d->count++;

        /* insert rrset into linked list for domain */
        /* find sorted place to link the rrset into the list */
        prev = NULL;
        p = node->rrsets;
        while(p && p->type<=rr_type) {
                prev = p;
                p = p->next;
        }
        /* so, prev is smaller, and p is larger than rr_type */
        rrset->next = p;
        if(prev) prev->next = rrset;
        else node->rrsets = rrset;
        return rrset;
}

/** count number (and size) of rrsigs that cover a type */
static size_t
rrsig_num_that_cover(struct auth_rrset* rrsig, uint16_t rr_type, size_t* sigsz)
{
        struct packed_rrset_data* d = rrsig->data;
        size_t i, num = 0;
        *sigsz = 0;
        log_assert(d && rrsig->type == LDNS_RR_TYPE_RRSIG);
        for(i=0; i<d->count+d->rrsig_count; i++) {
                if(rrsig_rdata_get_type_covered(d->rr_data[i],
                        d->rr_len[i]) == rr_type) {
                        num++;
                        (*sigsz) += d->rr_len[i];
                }
        }
        return num;
}

/** See if rrsig set has covered sigs for rrset and move them over */
static int
rrset_moveover_rrsigs(struct auth_data* node, uint16_t rr_type,
        struct auth_rrset* rrset, struct auth_rrset* rrsig)
{
        size_t sigs, sigsz, i, j, total;
        struct packed_rrset_data* sigold = rrsig->data;
        struct packed_rrset_data* old = rrset->data;
        struct packed_rrset_data* d, *sigd;

        log_assert(rrset->type == rr_type);
        log_assert(rrsig->type == LDNS_RR_TYPE_RRSIG);
        sigs = rrsig_num_that_cover(rrsig, rr_type, &sigsz);
        if(sigs == 0) {
                /* 0 rrsigs to move over, done */
                return 1;
        }

        /* allocate rrset sigsz larger for extra sigs elements, and
         * allocate rrsig sigsz smaller for less sigs elements. */
        d = (struct packed_rrset_data*)calloc(1, packed_rrset_sizeof(old)
                + sigs*(sizeof(size_t) + sizeof(uint8_t*) + sizeof(time_t))
                + sigsz);
        if(!d) {
                log_err("out of memory");
                return 0;
        }
        /* copy base values */
        total = old->count + old->rrsig_count;
        memcpy(d, old, sizeof(struct packed_rrset_data));
        d->rrsig_count += sigs;
        /* setup rr_len */
        d->rr_len = (size_t*)((uint8_t*)d +
                sizeof(struct packed_rrset_data));
        if(total != 0)
                memmove(d->rr_len, old->rr_len, total*sizeof(size_t));
        j = d->count+d->rrsig_count-sigs;
        for(i=0; i<sigold->count+sigold->rrsig_count; i++) {
                if(rrsig_rdata_get_type_covered(sigold->rr_data[i],
                        sigold->rr_len[i]) == rr_type) {
                        d->rr_len[j] = sigold->rr_len[i];
                        j++;
                }
        }
        packed_rrset_ptr_fixup(d);

        /* copy old values into new array */
        if(total != 0) {
                memmove(d->rr_ttl, old->rr_ttl, total*sizeof(time_t));
                /* all the old rr pieces are allocated sequential, so we
                 * can copy them in one go */
                memmove(d->rr_data[0], old->rr_data[0],
                        (old->rr_data[total-1] - old->rr_data[0]) +
                        old->rr_len[total-1]);
        }

        /* move over the rrsigs to the larger rrset*/
        j = d->count+d->rrsig_count-sigs;
        for(i=0; i<sigold->count+sigold->rrsig_count; i++) {
                if(rrsig_rdata_get_type_covered(sigold->rr_data[i],
                        sigold->rr_len[i]) == rr_type) {
                        /* move this one over to location j */
                        d->rr_ttl[j] = sigold->rr_ttl[i];
                        memmove(d->rr_data[j], sigold->rr_data[i],
                                sigold->rr_len[i]);
                        if(d->rr_ttl[j] < d->ttl)
                                d->ttl = d->rr_ttl[j];
                        j++;
                }
        }

        /* put it in and deallocate the old rrset */
        rrset->data = d;
        free(old);

        /* now make rrsig set smaller */
        if(sigold->count+sigold->rrsig_count == sigs) {
                /* remove all sigs from rrsig, remove it entirely */
                domain_remove_rrset(node, LDNS_RR_TYPE_RRSIG);
                return 1;
        }
        log_assert(packed_rrset_sizeof(sigold) > sigs*(sizeof(size_t) +
                sizeof(uint8_t*) + sizeof(time_t)) + sigsz);
        sigd = (struct packed_rrset_data*)calloc(1, packed_rrset_sizeof(sigold)
                - sigs*(sizeof(size_t) + sizeof(uint8_t*) + sizeof(time_t))
                - sigsz);
        if(!sigd) {
                /* no need to free up d, it has already been placed in the
                 * node->rrset structure */
                log_err("out of memory");
                return 0;
        }
        /* copy base values */
        memcpy(sigd, sigold, sizeof(struct packed_rrset_data));
        /* in sigd the RRSIGs are stored in the base of the RR, in count */
        sigd->count -= sigs;
        /* setup rr_len */
        sigd->rr_len = (size_t*)((uint8_t*)sigd +
                sizeof(struct packed_rrset_data));
        j = 0;
        for(i=0; i<sigold->count+sigold->rrsig_count; i++) {
                if(rrsig_rdata_get_type_covered(sigold->rr_data[i],
                        sigold->rr_len[i]) != rr_type) {
                        sigd->rr_len[j] = sigold->rr_len[i];
                        j++;
                }
        }
        packed_rrset_ptr_fixup(sigd);

        /* copy old values into new rrsig array */
        j = 0;
        for(i=0; i<sigold->count+sigold->rrsig_count; i++) {
                if(rrsig_rdata_get_type_covered(sigold->rr_data[i],
                        sigold->rr_len[i]) != rr_type) {
                        /* move this one over to location j */
                        sigd->rr_ttl[j] = sigold->rr_ttl[i];
                        memmove(sigd->rr_data[j], sigold->rr_data[i],
                                sigold->rr_len[i]);
                        if(j==0) sigd->ttl = sigd->rr_ttl[j];
                        else {
                                if(sigd->rr_ttl[j] < sigd->ttl)
                                        sigd->ttl = sigd->rr_ttl[j];
                        }
                        j++;
                }
        }

        /* put it in and deallocate the old rrset */
        rrsig->data = sigd;
        free(sigold);

        return 1;
}

/** copy the rrsigs from the rrset to the rrsig rrset, because the rrset
 * is going to be deleted.  reallocates the RRSIG rrset data. */
static int
rrsigs_copy_from_rrset_to_rrsigset(struct auth_rrset* rrset,
        struct auth_rrset* rrsigset)
{
        size_t i;
        if(rrset->data->rrsig_count == 0)
                return 1;

        /* move them over one by one, because there might be duplicates,
         * duplicates are ignored */
        for(i=rrset->data->count;
                i<rrset->data->count+rrset->data->rrsig_count; i++) {
                uint8_t* rdata = rrset->data->rr_data[i];
                size_t rdatalen = rrset->data->rr_len[i];
                time_t rr_ttl  = rrset->data->rr_ttl[i];

                if(rdata_duplicate(rrsigset->data, rdata, rdatalen)) {
                        continue;
                }
                if(!rrset_add_rr(rrsigset, rr_ttl, rdata, rdatalen, 0))
                        return 0;
        }
        return 1;
}

/** Add rr to node, ignores duplicate RRs,
 * rdata points to buffer with rdatalen octets, starts with 2bytelength. */
static int
az_domain_add_rr(struct auth_data* node, uint16_t rr_type, uint32_t rr_ttl,
        uint8_t* rdata, size_t rdatalen, int* duplicate)
{
        struct auth_rrset* rrset;
        /* packed rrsets have their rrsigs along with them, sort them out */
        if(rr_type == LDNS_RR_TYPE_RRSIG) {
                uint16_t ctype = rrsig_rdata_get_type_covered(rdata, rdatalen);
                if((rrset=az_domain_rrset(node, ctype))!= NULL) {
                        /* a node of the correct type exists, add the RRSIG
                         * to the rrset of the covered data type */
                        if(rdata_duplicate(rrset->data, rdata, rdatalen)) {
                                if(duplicate) *duplicate = 1;
                                return 1;
                        }
                        if(!rrset_add_rr(rrset, rr_ttl, rdata, rdatalen, 1))
                                return 0;
                } else if((rrset=az_domain_rrset(node, rr_type))!= NULL) {
                        /* add RRSIG to rrset of type RRSIG */
                        if(rdata_duplicate(rrset->data, rdata, rdatalen)) {
                                if(duplicate) *duplicate = 1;
                                return 1;
                        }
                        if(!rrset_add_rr(rrset, rr_ttl, rdata, rdatalen, 0))
                                return 0;
                } else {
                        /* create rrset of type RRSIG */
                        if(!rrset_create(node, rr_type, rr_ttl, rdata,
                                rdatalen))
                                return 0;
                }
        } else {
                /* normal RR type */
                if((rrset=az_domain_rrset(node, rr_type))!= NULL) {
                        /* add data to existing node with data type */
                        if(rdata_duplicate(rrset->data, rdata, rdatalen)) {
                                if(duplicate) *duplicate = 1;
                                return 1;
                        }
                        if(!rrset_add_rr(rrset, rr_ttl, rdata, rdatalen, 0))
                                return 0;
                } else {
                        struct auth_rrset* rrsig;
                        /* create new node with data type */
                        if(!(rrset=rrset_create(node, rr_type, rr_ttl, rdata,
                                rdatalen)))
                                return 0;

                        /* see if node of type RRSIG has signatures that
                         * cover the data type, and move them over */
                        /* and then make the RRSIG type smaller */
                        if((rrsig=az_domain_rrset(node, LDNS_RR_TYPE_RRSIG))
                                != NULL) {
                                if(!rrset_moveover_rrsigs(node, rr_type,
                                        rrset, rrsig))
                                        return 0;
                        }
                }
        }
        return 1;
}

/** insert RR into zone, ignore duplicates */
static int
az_insert_rr(struct auth_zone* z, uint8_t* rr, size_t rr_len,
        size_t dname_len, int* duplicate)
{
        struct auth_data* node;
        uint8_t* dname = rr;
        uint16_t rr_type = sldns_wirerr_get_type(rr, rr_len, dname_len);
        uint16_t rr_class = sldns_wirerr_get_class(rr, rr_len, dname_len);
        uint32_t rr_ttl = sldns_wirerr_get_ttl(rr, rr_len, dname_len);
        size_t rdatalen = ((size_t)sldns_wirerr_get_rdatalen(rr, rr_len,
                dname_len))+2;
        /* rdata points to rdata prefixed with uint16 rdatalength */
        uint8_t* rdata = sldns_wirerr_get_rdatawl(rr, rr_len, dname_len);

        if(rr_class != z->dclass) {
                log_err("wrong class for RR");
                return 0;
        }
        if(!(node=az_domain_find_or_create(z, dname, dname_len))) {
                log_err("cannot create domain");
                return 0;
        }
        if(!az_domain_add_rr(node, rr_type, rr_ttl, rdata, rdatalen,
                duplicate)) {
                log_err("cannot add RR to domain");
                return 0;
        }
        if(z->rpz) {
                if(!(rpz_insert_rr(z->rpz, z->name, z->namelen, dname,
                        dname_len, rr_type, rr_class, rr_ttl, rdata, rdatalen,
                        rr, rr_len)))
                        return 0;
        }
        return 1;
}

/** Remove rr from node, ignores nonexisting RRs,
 * rdata points to buffer with rdatalen octets, starts with 2bytelength. */
static int
az_domain_remove_rr(struct auth_data* node, uint16_t rr_type,
        uint8_t* rdata, size_t rdatalen, int* nonexist)
{
        struct auth_rrset* rrset;
        size_t index = 0;

        /* find the plain RR of the given type */
        if((rrset=az_domain_rrset(node, rr_type))!= NULL) {
                if(packed_rrset_find_rr(rrset->data, rdata, rdatalen, &index)) {
                        if(rrset->data->count == 1 &&
                                rrset->data->rrsig_count == 0) {
                                /* last RR, delete the rrset */
                                domain_remove_rrset(node, rr_type);
                        } else if(rrset->data->count == 1 &&
                                rrset->data->rrsig_count != 0) {
                                /* move RRSIGs to the RRSIG rrset, or
                                 * this one becomes that RRset */
                                struct auth_rrset* rrsigset = az_domain_rrset(
                                        node, LDNS_RR_TYPE_RRSIG);
                                if(rrsigset) {
                                        /* move left over rrsigs to the
                                         * existing rrset of type RRSIG */
                                        rrsigs_copy_from_rrset_to_rrsigset(
                                                rrset, rrsigset);
                                        /* and then delete the rrset */
                                        domain_remove_rrset(node, rr_type);
                                } else {
                                        /* no rrset of type RRSIG, this
                                         * set is now of that type,
                                         * just remove the rr */
                                        if(!rrset_remove_rr(rrset, index))
                                                return 0;
                                        rrset->type = LDNS_RR_TYPE_RRSIG;
                                        rrset->data->count = rrset->data->rrsig_count;
                                        rrset->data->rrsig_count = 0;
                                }
                        } else {
                                /* remove the RR from the rrset */
                                if(!rrset_remove_rr(rrset, index))
                                        return 0;
                        }
                        return 1;
                }
                /* rr not found in rrset */
        }

        /* is it a type RRSIG, look under the covered type */
        if(rr_type == LDNS_RR_TYPE_RRSIG) {
                uint16_t ctype = rrsig_rdata_get_type_covered(rdata, rdatalen);
                if((rrset=az_domain_rrset(node, ctype))!= NULL) {
                        if(az_rrset_find_rrsig(rrset->data, rdata, rdatalen,
                                &index)) {
                                /* rrsig should have d->count > 0, be
                                 * over some rr of that type */
                                /* remove the rrsig from the rrsigs list of the
                                 * rrset */
                                if(!rrset_remove_rr(rrset, index))
                                        return 0;
                                return 1;
                        }
                }
                /* also RRSIG not found */
        }

        /* nothing found to delete */
        if(nonexist) *nonexist = 1;
        return 1;
}

/** remove RR from zone, ignore if it does not exist, false on alloc failure*/
static int
az_remove_rr(struct auth_zone* z, uint8_t* rr, size_t rr_len,
        size_t dname_len, int* nonexist)
{
        struct auth_data* node;
        uint8_t* dname = rr;
        uint16_t rr_type = sldns_wirerr_get_type(rr, rr_len, dname_len);
        uint16_t rr_class = sldns_wirerr_get_class(rr, rr_len, dname_len);
        size_t rdatalen = ((size_t)sldns_wirerr_get_rdatalen(rr, rr_len,
                dname_len))+2;
        /* rdata points to rdata prefixed with uint16 rdatalength */
        uint8_t* rdata = sldns_wirerr_get_rdatawl(rr, rr_len, dname_len);

        if(rr_class != z->dclass) {
                log_err("wrong class for RR");
                /* really also a nonexisting entry, because no records
                 * of that class in the zone, but return an error because
                 * getting records of the wrong class is a failure of the
                 * zone transfer */
                return 0;
        }
        node = az_find_name(z, dname, dname_len);
        if(!node) {
                /* node with that name does not exist */
                /* nonexisting entry, because no such name */
                *nonexist = 1;
                return 1;
        }
        if(!az_domain_remove_rr(node, rr_type, rdata, rdatalen, nonexist)) {
                /* alloc failure or so */
                return 0;
        }
        /* remove the node, if necessary */
        /* an rrsets==NULL entry is not kept around for empty nonterminals,
         * and also parent nodes are not kept around, so we just delete it */
        if(node->rrsets == NULL) {
                (void)rbtree_delete(&z->data, node);
                auth_data_delete(node);
        }
        if(z->rpz) {
                rpz_remove_rr(z->rpz, z->name, z->namelen, dname, dname_len,
                        rr_type, rr_class, rdata, rdatalen);
        }
        return 1;
}

/** decompress an RR into the buffer where it'll be an uncompressed RR
 * with uncompressed dname and uncompressed rdata (dnames) */
static int
decompress_rr_into_buffer(struct sldns_buffer* buf, uint8_t* pkt,
        size_t pktlen, uint8_t* dname, uint16_t rr_type, uint16_t rr_class,
        uint32_t rr_ttl, uint8_t* rr_data, uint16_t rr_rdlen)
{
        sldns_buffer pktbuf;
        size_t dname_len = 0;
        size_t rdlenpos;
        size_t rdlen;
        uint8_t* rd;
        const sldns_rr_descriptor* desc;
        sldns_buffer_init_frm_data(&pktbuf, pkt, pktlen);
        sldns_buffer_clear(buf);

        /* decompress dname */
        sldns_buffer_set_position(&pktbuf,
                (size_t)(dname - sldns_buffer_current(&pktbuf)));
        dname_len = pkt_dname_len(&pktbuf);
        if(dname_len == 0) return 0; /* parse fail on dname */
        if(!sldns_buffer_available(buf, dname_len)) return 0;
        dname_pkt_copy(&pktbuf, sldns_buffer_current(buf), dname);
        sldns_buffer_skip(buf, (ssize_t)dname_len);

        /* type, class, ttl and rdatalength fields */
        if(!sldns_buffer_available(buf, 10)) return 0;
        sldns_buffer_write_u16(buf, rr_type);
        sldns_buffer_write_u16(buf, rr_class);
        sldns_buffer_write_u32(buf, rr_ttl);
        rdlenpos = sldns_buffer_position(buf);
        sldns_buffer_write_u16(buf, 0); /* rd length position */

        /* decompress rdata */
        desc = sldns_rr_descript(rr_type);
        rd = rr_data;
        rdlen = rr_rdlen;
        if(rdlen > 0 && desc && desc->_dname_count > 0) {
                int count = (int)desc->_dname_count;
                int rdf = 0;
                size_t len; /* how much rdata to plain copy */
                size_t uncompressed_len, compressed_len;
                size_t oldpos;
                /* decompress dnames. */
                while(rdlen > 0 && count) {
                        switch(desc->_wireformat[rdf]) {
                        case LDNS_RDF_TYPE_DNAME:
                                sldns_buffer_set_position(&pktbuf,
                                        (size_t)(rd -
                                        sldns_buffer_begin(&pktbuf)));
                                oldpos = sldns_buffer_position(&pktbuf);
                                /* moves pktbuf to right after the
                                 * compressed dname, and returns uncompressed
                                 * dname length */
                                uncompressed_len = pkt_dname_len(&pktbuf);
                                if(!uncompressed_len)
                                        return 0; /* parse error in dname */
                                if(!sldns_buffer_available(buf,
                                        uncompressed_len))
                                        /* dname too long for buffer */
                                        return 0;
                                dname_pkt_copy(&pktbuf, 
                                        sldns_buffer_current(buf), rd);
                                sldns_buffer_skip(buf, (ssize_t)uncompressed_len);
                                compressed_len = sldns_buffer_position(
                                        &pktbuf) - oldpos;
                                rd += compressed_len;
                                rdlen -= compressed_len;
                                count--;
                                len = 0;
                                break;
                        case LDNS_RDF_TYPE_STR:
                                len = rd[0] + 1;
                                break;
                        default:
                                len = get_rdf_size(desc->_wireformat[rdf]);
                                break;
                        }
                        if(len) {
                                if(!sldns_buffer_available(buf, len))
                                        return 0; /* too long for buffer */
                                sldns_buffer_write(buf, rd, len);
                                rd += len;
                                rdlen -= len;
                        }
                        rdf++;
                }
        }
        /* copy remaining data */
        if(rdlen > 0) {
                if(!sldns_buffer_available(buf, rdlen)) return 0;
                sldns_buffer_write(buf, rd, rdlen);
        }
        /* fixup rdlength */
        sldns_buffer_write_u16_at(buf, rdlenpos,
                sldns_buffer_position(buf)-rdlenpos-2);
        sldns_buffer_flip(buf);
        return 1;
}

/** insert RR into zone, from packet, decompress RR,
 * if duplicate is nonNULL set the flag but otherwise ignore duplicates */
static int
az_insert_rr_decompress(struct auth_zone* z, uint8_t* pkt, size_t pktlen,
        struct sldns_buffer* scratch_buffer, uint8_t* dname, uint16_t rr_type,
        uint16_t rr_class, uint32_t rr_ttl, uint8_t* rr_data,
        uint16_t rr_rdlen, int* duplicate)
{
        uint8_t* rr;
        size_t rr_len;
        size_t dname_len;
        if(!decompress_rr_into_buffer(scratch_buffer, pkt, pktlen, dname,
                rr_type, rr_class, rr_ttl, rr_data, rr_rdlen)) {
                log_err("could not decompress RR");
                return 0;
        }
        rr = sldns_buffer_begin(scratch_buffer);
        rr_len = sldns_buffer_limit(scratch_buffer);
        dname_len = dname_valid(rr, rr_len);
        return az_insert_rr(z, rr, rr_len, dname_len, duplicate);
}

/** remove RR from zone, from packet, decompress RR,
 * if nonexist is nonNULL set the flag but otherwise ignore nonexisting entries*/
static int
az_remove_rr_decompress(struct auth_zone* z, uint8_t* pkt, size_t pktlen,
        struct sldns_buffer* scratch_buffer, uint8_t* dname, uint16_t rr_type,
        uint16_t rr_class, uint32_t rr_ttl, uint8_t* rr_data,
        uint16_t rr_rdlen, int* nonexist)
{
        uint8_t* rr;
        size_t rr_len;
        size_t dname_len;
        if(!decompress_rr_into_buffer(scratch_buffer, pkt, pktlen, dname,
                rr_type, rr_class, rr_ttl, rr_data, rr_rdlen)) {
                log_err("could not decompress RR");
                return 0;
        }
        rr = sldns_buffer_begin(scratch_buffer);
        rr_len = sldns_buffer_limit(scratch_buffer);
        dname_len = dname_valid(rr, rr_len);
        return az_remove_rr(z, rr, rr_len, dname_len, nonexist);
}

/** 
 * Parse zonefile
 * @param z: zone to read in.
 * @param in: file to read from (just opened).
 * @param rr: buffer to use for RRs, 64k.
 *      passed so that recursive includes can use the same buffer and do
 *      not grow the stack too much.
 * @param rrbuflen: sizeof rr buffer.
 * @param state: parse state with $ORIGIN, $TTL and 'prev-dname' and so on,
 *      that is kept between includes.
 *      The lineno is set at 1 and then increased by the function.
 * @param fname: file name.
 * @param depth: recursion depth for includes
 * @param cfg: config for chroot.
 * returns false on failure, has printed an error message
 */
static int
az_parse_file(struct auth_zone* z, FILE* in, uint8_t* rr, size_t rrbuflen,
        struct sldns_file_parse_state* state, char* fname, int depth,
        struct config_file* cfg)
{
        size_t rr_len, dname_len;
        int status;
        state->lineno = 1;

        while(!feof(in)) {
                rr_len = rrbuflen;
                dname_len = 0;
                status = sldns_fp2wire_rr_buf(in, rr, &rr_len, &dname_len,
                        state);
                if(status == LDNS_WIREPARSE_ERR_INCLUDE && rr_len == 0) {
                        /* we have $INCLUDE or $something */
                        if(strncmp((char*)rr, "$INCLUDE ", 9) == 0 ||
                           strncmp((char*)rr, "$INCLUDE\t", 9) == 0) {
                                FILE* inc;
                                int lineno_orig = state->lineno;
                                char* incfile = (char*)rr + 8;
                                if(depth > MAX_INCLUDE_DEPTH) {
                                        log_err("%s:%d max include depth"
                                          "exceeded", fname, state->lineno);
                                        return 0;
                                }
                                /* skip spaces */
                                while(*incfile == ' ' || *incfile == '\t')
                                        incfile++;
                                /* adjust for chroot on include file */
                                if(cfg->chrootdir && cfg->chrootdir[0] &&
                                        strncmp(incfile, cfg->chrootdir,
                                                strlen(cfg->chrootdir)) == 0)
                                        incfile += strlen(cfg->chrootdir);
                                incfile = strdup(incfile);
                                if(!incfile) {
                                        log_err("malloc failure");
                                        return 0;
                                }
                                verbose(VERB_ALGO, "opening $INCLUDE %s",
                                        incfile);
                                inc = fopen(incfile, "r");
                                if(!inc) {
                                        log_err("%s:%d cannot open include "
                                                "file %s: %s", fname,
                                                lineno_orig, incfile,
                                                strerror(errno));
                                        free(incfile);
                                        return 0;
                                }
                                /* recurse read that file now */
                                if(!az_parse_file(z, inc, rr, rrbuflen,
                                        state, incfile, depth+1, cfg)) {
                                        log_err("%s:%d cannot parse include "
                                                "file %s", fname,
                                                lineno_orig, incfile);
                                        fclose(inc);
                                        free(incfile);
                                        return 0;
                                }
                                fclose(inc);
                                verbose(VERB_ALGO, "done with $INCLUDE %s",
                                        incfile);
                                free(incfile);
                                state->lineno = lineno_orig;
                        }
                        continue;
                }
                if(status != 0) {
                        log_err("parse error %s %d:%d: %s", fname,
                                state->lineno, LDNS_WIREPARSE_OFFSET(status),
                                sldns_get_errorstr_parse(status));
                        return 0;
                }
                if(rr_len == 0) {
                        /* EMPTY line, TTL or ORIGIN */
                        continue;
                }
                /* insert wirerr in rrbuf */
                if(!az_insert_rr(z, rr, rr_len, dname_len, NULL)) {
                        char buf[17];
                        sldns_wire2str_type_buf(sldns_wirerr_get_type(rr,
                                rr_len, dname_len), buf, sizeof(buf));
                        log_err("%s:%d cannot insert RR of type %s",
                                fname, state->lineno, buf);
                        return 0;
                }
        }
        return 1;
}

int
auth_zone_read_zonefile(struct auth_zone* z, struct config_file* cfg)
{
        uint8_t rr[LDNS_RR_BUF_SIZE];
        struct sldns_file_parse_state state;
        char* zfilename;
        FILE* in;
        if(!z || !z->zonefile || z->zonefile[0]==0)
                return 1; /* no file, or "", nothing to read */
        
        zfilename = z->zonefile;
        if(cfg->chrootdir && cfg->chrootdir[0] && strncmp(zfilename,
                cfg->chrootdir, strlen(cfg->chrootdir)) == 0)
                zfilename += strlen(cfg->chrootdir);
        if(verbosity >= VERB_ALGO) {
                char nm[LDNS_MAX_DOMAINLEN];
                dname_str(z->name, nm);
                verbose(VERB_ALGO, "read zonefile %s for %s", zfilename, nm);
        }
        in = fopen(zfilename, "r");
        if(!in) {
                char* n = sldns_wire2str_dname(z->name, z->namelen);
                if(z->zone_is_slave && errno == ENOENT) {
                        /* we fetch the zone contents later, no file yet */
                        verbose(VERB_ALGO, "no zonefile %s for %s",
                                zfilename, n?n:"error");
                        free(n);
                        return 1;
                }
                log_err("cannot open zonefile %s for %s: %s",
                        zfilename, n?n:"error", strerror(errno));
                free(n);
                return 0;
        }

        /* clear the data tree */
        traverse_postorder(&z->data, auth_data_del, NULL);
        rbtree_init(&z->data, &auth_data_cmp);
        /* clear the RPZ policies */
        if(z->rpz)
                rpz_clear(z->rpz);

        memset(&state, 0, sizeof(state));
        /* default TTL to 3600 */
        state.default_ttl = 3600;
        /* set $ORIGIN to the zone name */
        if(z->namelen <= sizeof(state.origin)) {
                memcpy(state.origin, z->name, z->namelen);
                state.origin_len = z->namelen;
        }
        /* parse the (toplevel) file */
        if(!az_parse_file(z, in, rr, sizeof(rr), &state, zfilename, 0, cfg)) {
                char* n = sldns_wire2str_dname(z->name, z->namelen);
                log_err("error parsing zonefile %s for %s",
                        zfilename, n?n:"error");
                free(n);
                fclose(in);
                return 0;
        }
        fclose(in);

        if(z->rpz)
                rpz_finish_config(z->rpz);
        return 1;
}

/** write buffer to file and check return codes */
static int
write_out(FILE* out, const char* str, size_t len)
{
        size_t r;
        if(len == 0)
                return 1;
        r = fwrite(str, 1, len, out);
        if(r == 0) {
                log_err("write failed: %s", strerror(errno));
                return 0;
        } else if(r < len) {
                log_err("write failed: too short (disk full?)");
                return 0;
        }
        return 1;
}

/** convert auth rr to string */
static int
auth_rr_to_string(uint8_t* nm, size_t nmlen, uint16_t tp, uint16_t cl,
        struct packed_rrset_data* data, size_t i, char* s, size_t buflen)
{
        int w = 0;
        size_t slen = buflen, datlen;
        uint8_t* dat;
        if(i >= data->count) tp = LDNS_RR_TYPE_RRSIG;
        dat = nm;
        datlen = nmlen;
        w += sldns_wire2str_dname_scan(&dat, &datlen, &s, &slen, NULL, 0, NULL);
        w += sldns_str_print(&s, &slen, "\t");
        w += sldns_str_print(&s, &slen, "%lu\t", (unsigned long)data->rr_ttl[i]);
        w += sldns_wire2str_class_print(&s, &slen, cl);
        w += sldns_str_print(&s, &slen, "\t");
        w += sldns_wire2str_type_print(&s, &slen, tp);
        w += sldns_str_print(&s, &slen, "\t");
        datlen = data->rr_len[i]-2;
        dat = data->rr_data[i]+2;
        w += sldns_wire2str_rdata_scan(&dat, &datlen, &s, &slen, tp, NULL, 0, NULL);

        if(tp == LDNS_RR_TYPE_DNSKEY) {
                w += sldns_str_print(&s, &slen, " ;{id = %u}",
                        sldns_calc_keytag_raw(data->rr_data[i]+2,
                                data->rr_len[i]-2));
        }
        w += sldns_str_print(&s, &slen, "\n");

        if(w >= (int)buflen) {
                log_nametypeclass(NO_VERBOSE, "RR too long to print", nm, tp, cl);
                return 0;
        }
        return 1;
}

/** write rrset to file */
static int
auth_zone_write_rrset(struct auth_zone* z, struct auth_data* node,
        struct auth_rrset* r, FILE* out)
{
        size_t i, count = r->data->count + r->data->rrsig_count;
        char buf[LDNS_RR_BUF_SIZE];
        for(i=0; i<count; i++) {
                if(!auth_rr_to_string(node->name, node->namelen, r->type,
                        z->dclass, r->data, i, buf, sizeof(buf))) {
                        verbose(VERB_ALGO, "failed to rr2str rr %d", (int)i);
                        continue;
                }
                if(!write_out(out, buf, strlen(buf)))
                        return 0;
        }
        return 1;
}

/** write domain to file */
static int
auth_zone_write_domain(struct auth_zone* z, struct auth_data* n, FILE* out)
{
        struct auth_rrset* r;
        /* if this is zone apex, write SOA first */
        if(z->namelen == n->namelen) {
                struct auth_rrset* soa = az_domain_rrset(n, LDNS_RR_TYPE_SOA);
                if(soa) {
                        if(!auth_zone_write_rrset(z, n, soa, out))
                                return 0;
                }
        }
        /* write all the RRsets for this domain */
        for(r = n->rrsets; r; r = r->next) {
                if(z->namelen == n->namelen &&
                        r->type == LDNS_RR_TYPE_SOA)
                        continue; /* skip SOA here */
                if(!auth_zone_write_rrset(z, n, r, out))
                        return 0;
        }
        return 1;
}

int auth_zone_write_file(struct auth_zone* z, const char* fname)
{
        FILE* out;
        struct auth_data* n;
        out = fopen(fname, "w");
        if(!out) {
                log_err("could not open %s: %s", fname, strerror(errno));
                return 0;
        }
        RBTREE_FOR(n, struct auth_data*, &z->data) {
                if(!auth_zone_write_domain(z, n, out)) {
                        log_err("could not write domain to %s", fname);
                        fclose(out);
                        return 0;
                }
        }
        fclose(out);
        return 1;
}

/** offline verify for zonemd, while reading a zone file to immediately
 * spot bad hashes in zonefile as they are read.
 * Creates temp buffers, but uses anchors and validation environment
 * from the module_env. */
static void
zonemd_offline_verify(struct auth_zone* z, struct module_env* env_for_val,
        struct module_stack* mods)
{
        struct module_env env;
        time_t now = 0;
        if(!z->zonemd_check)
                return;
        env = *env_for_val;
        env.scratch_buffer = sldns_buffer_new(env.cfg->msg_buffer_size);
        if(!env.scratch_buffer) {
                log_err("out of memory");
                goto clean_exit;
        }
        env.scratch = regional_create();
        if(!env.now) {
                env.now = &now;
                now = time(NULL);
        }
        if(!env.scratch) {
                log_err("out of memory");
                goto clean_exit;
        }
        auth_zone_verify_zonemd(z, &env, mods, NULL, 1, 0);

clean_exit:
        /* clean up and exit */
        sldns_buffer_free(env.scratch_buffer);
        regional_destroy(env.scratch);
}

/** read all auth zones from file (if they have) */
static int
auth_zones_read_zones(struct auth_zones* az, struct config_file* cfg,
        struct module_env* env, struct module_stack* mods)
{
        struct auth_zone* z;
        lock_rw_wrlock(&az->lock);
        RBTREE_FOR(z, struct auth_zone*, &az->ztree) {
                lock_rw_wrlock(&z->lock);
                if(!auth_zone_read_zonefile(z, cfg)) {
                        lock_rw_unlock(&z->lock);
                        lock_rw_unlock(&az->lock);
                        return 0;
                }
                if(z->zonefile && z->zonefile[0]!=0 && env)
                        zonemd_offline_verify(z, env, mods);
                lock_rw_unlock(&z->lock);
        }
        lock_rw_unlock(&az->lock);
        return 1;
}

/** fetch the content of a ZONEMD RR from the rdata */
static int zonemd_fetch_parameters(struct auth_rrset* zonemd_rrset, size_t i,
        uint32_t* serial, int* scheme, int* hashalgo, uint8_t** hash,
        size_t* hashlen)
{
        size_t rr_len;
        uint8_t* rdata;
        if(i >= zonemd_rrset->data->count)
                return 0;
        rr_len = zonemd_rrset->data->rr_len[i];
        if(rr_len < 2+4+1+1)
                return 0; /* too short, for rdlen+serial+scheme+algo */
        rdata = zonemd_rrset->data->rr_data[i];
        *serial = sldns_read_uint32(rdata+2);
        *scheme = rdata[6];
        *hashalgo = rdata[7];
        *hashlen = rr_len - 8;
        if(*hashlen == 0)
                *hash = NULL;
        else    *hash = rdata+8;
        return 1;
}

/**
 * See if the ZONEMD scheme, hash occurs more than once.
 * @param zonemd_rrset: the zonemd rrset to check with the RRs in it.
 * @param index: index of the original, this is allowed to have that
 *      scheme and hashalgo, but other RRs should not have it.
 * @param scheme: the scheme to check for.
 * @param hashalgo: the hash algorithm to check for.
 * @return true if it occurs more than once.
 */
static int zonemd_is_duplicate_scheme_hash(struct auth_rrset* zonemd_rrset,
        size_t index, int scheme, int hashalgo)
{
        size_t j;
        for(j=0; j<zonemd_rrset->data->count; j++) {
                uint32_t serial2 = 0;
                int scheme2 = 0, hashalgo2 = 0;
                uint8_t* hash2 = NULL;
                size_t hashlen2 = 0;
                if(index == j) {
                        /* this is the original */
                        continue;
                }
                if(!zonemd_fetch_parameters(zonemd_rrset, j, &serial2,
                        &scheme2, &hashalgo2, &hash2, &hashlen2)) {
                        /* malformed, skip it */
                        continue;
                }
                if(scheme == scheme2 && hashalgo == hashalgo2) {
                        /* duplicate scheme, hash */
                        verbose(VERB_ALGO, "zonemd duplicate for scheme %d "
                                "and hash %d", scheme, hashalgo);
                        return 1;
                }
        }
        return 0;
}

/**
 * Check ZONEMDs if present for the auth zone.  Depending on config
 * it can warn or fail on that.  Checks the hash of the ZONEMD.
 * @param z: auth zone to check for.
 *      caller must hold lock on zone.
 * @param env: module env for temp buffers.
 * @param reason: returned on failure.
 * @return false on failure, true if hash checks out.
 */
static int auth_zone_zonemd_check_hash(struct auth_zone* z,
        struct module_env* env, char** reason)
{
        /* loop over ZONEMDs and see which one is valid. if not print
         * failure (depending on config) */
        struct auth_data* apex;
        struct auth_rrset* zonemd_rrset;
        size_t i;
        struct regional* region = NULL;
        struct sldns_buffer* buf = NULL;
        uint32_t soa_serial = 0;
        char* unsupported_reason = NULL;
        int only_unsupported = 1;
        region = env->scratch;
        regional_free_all(region);
        buf = env->scratch_buffer;
        if(!auth_zone_get_serial(z, &soa_serial)) {
                *reason = "zone has no SOA serial";
                return 0;
        }

        apex = az_find_name(z, z->name, z->namelen);
        if(!apex) {
                *reason = "zone has no apex";
                return 0;
        }
        zonemd_rrset = az_domain_rrset(apex, LDNS_RR_TYPE_ZONEMD);
        if(!zonemd_rrset || zonemd_rrset->data->count==0) {
                *reason = "zone has no ZONEMD";
                return 0; /* no RRset or no RRs in rrset */
        }

        /* we have a ZONEMD, check if it is correct */
        for(i=0; i<zonemd_rrset->data->count; i++) {
                uint32_t serial = 0;
                int scheme = 0, hashalgo = 0;
                uint8_t* hash = NULL;
                size_t hashlen = 0;
                if(!zonemd_fetch_parameters(zonemd_rrset, i, &serial, &scheme,
                        &hashalgo, &hash, &hashlen)) {
                        /* malformed RR */
                        *reason = "ZONEMD rdata malformed";
                        only_unsupported = 0;
                        continue;
                }
                /* check for duplicates */
                if(zonemd_is_duplicate_scheme_hash(zonemd_rrset, i, scheme,
                        hashalgo)) {
                        /* duplicate hash of the same scheme,hash
                         * is not allowed. */
                        *reason = "ZONEMD RRSet contains more than one RR "
                                "with the same scheme and hash algorithm";
                        only_unsupported = 0;
                        continue;
                }
                regional_free_all(region);
                if(serial != soa_serial) {
                        *reason = "ZONEMD serial is wrong";
                        only_unsupported = 0;
                        continue;
                }
                *reason = NULL;
                if(auth_zone_generate_zonemd_check(z, scheme, hashalgo,
                        hash, hashlen, region, buf, reason)) {
                        /* success */
                        if(*reason) {
                                if(!unsupported_reason)
                                        unsupported_reason = *reason;
                                /* continue to check for valid ZONEMD */
                                if(verbosity >= VERB_ALGO) {
                                        char zstr[LDNS_MAX_DOMAINLEN];
                                        dname_str(z->name, zstr);
                                        verbose(VERB_ALGO, "auth-zone %s ZONEMD %d %d is unsupported: %s", zstr, (int)scheme, (int)hashalgo, *reason);
                                }
                                *reason = NULL;
                                continue;
                        }
                        if(verbosity >= VERB_ALGO) {
                                char zstr[LDNS_MAX_DOMAINLEN];
                                dname_str(z->name, zstr);
                                if(!*reason)
                                        verbose(VERB_ALGO, "auth-zone %s ZONEMD hash is correct", zstr);
                        }
                        return 1;
                }
                only_unsupported = 0;
                /* try next one */
        }
        /* have we seen no failures but only unsupported algo,
         * and one unsupported algorithm, or more. */
        if(only_unsupported && unsupported_reason) {
                /* only unsupported algorithms, with valid serial, not
                 * malformed. Did not see supported algorithms, failed or
                 * successful ones. */
                *reason = unsupported_reason;
                return 1;
        }
        /* fail, we may have reason */
        if(!*reason)
                *reason = "no ZONEMD records found";
        if(verbosity >= VERB_ALGO) {
                char zstr[LDNS_MAX_DOMAINLEN];
                dname_str(z->name, zstr);
                verbose(VERB_ALGO, "auth-zone %s ZONEMD failed: %s", zstr, *reason);
        }
        return 0;
}

/** find the apex SOA RRset, if it exists */
struct auth_rrset* auth_zone_get_soa_rrset(struct auth_zone* z)
{
        struct auth_data* apex;
        struct auth_rrset* soa;
        apex = az_find_name(z, z->name, z->namelen);
        if(!apex) return NULL;
        soa = az_domain_rrset(apex, LDNS_RR_TYPE_SOA);
        return soa;
}

/** find serial number of zone or false if none */
int
auth_zone_get_serial(struct auth_zone* z, uint32_t* serial)
{
        struct auth_data* apex;
        struct auth_rrset* soa;
        struct packed_rrset_data* d;
        apex = az_find_name(z, z->name, z->namelen);
        if(!apex) return 0;
        soa = az_domain_rrset(apex, LDNS_RR_TYPE_SOA);
        if(!soa || soa->data->count==0)
                return 0; /* no RRset or no RRs in rrset */
        if(soa->data->rr_len[0] < 2+4*5) return 0; /* SOA too short */
        d = soa->data;
        *serial = sldns_read_uint32(d->rr_data[0]+(d->rr_len[0]-20));
        return 1;
}

/** Find auth_zone SOA and populate the values in xfr(soa values). */
int
xfr_find_soa(struct auth_zone* z, struct auth_xfer* xfr)
{
        struct auth_data* apex;
        struct auth_rrset* soa;
        struct packed_rrset_data* d;
        apex = az_find_name(z, z->name, z->namelen);
        if(!apex) return 0;
        soa = az_domain_rrset(apex, LDNS_RR_TYPE_SOA);
        if(!soa || soa->data->count==0)
                return 0; /* no RRset or no RRs in rrset */
        if(soa->data->rr_len[0] < 2+4*5) return 0; /* SOA too short */
        /* SOA record ends with serial, refresh, retry, expiry, minimum,
         * as 4 byte fields */
        d = soa->data;
        xfr->have_zone = 1;
        xfr->serial = sldns_read_uint32(d->rr_data[0]+(d->rr_len[0]-20));
        xfr->refresh = sldns_read_uint32(d->rr_data[0]+(d->rr_len[0]-16));
        xfr->retry = sldns_read_uint32(d->rr_data[0]+(d->rr_len[0]-12));
        xfr->expiry = sldns_read_uint32(d->rr_data[0]+(d->rr_len[0]-8));
        /* soa minimum at d->rr_len[0]-4 */
        return 1;
}

/** 
 * Setup auth_xfer zone
 * This populates the have_zone, soa values, and so on times.
 * Doesn't do network traffic yet, can set option flags.
 * @param z: locked by caller, and modified for setup
 * @param x: locked by caller, and modified.
 * @return false on failure.
 */
static int
auth_xfer_setup(struct auth_zone* z, struct auth_xfer* x)
{
        /* for a zone without zone transfers, x==NULL, so skip them,
         * i.e. the zone config is fixed with no masters or urls */
        if(!z || !x) return 1;
        if(!xfr_find_soa(z, x)) {
                return 1;
        }
        /* nothing for probe, nextprobe and transfer tasks */
        return 1;
}

/**
 * Setup all zones
 * @param az: auth zones structure
 * @return false on failure.
 */
static int
auth_zones_setup_zones(struct auth_zones* az)
{
        struct auth_zone* z;
        struct auth_xfer* x;
        lock_rw_wrlock(&az->lock);
        RBTREE_FOR(z, struct auth_zone*, &az->ztree) {
                lock_rw_wrlock(&z->lock);
                x = auth_xfer_find(az, z->name, z->namelen, z->dclass);
                if(x) {
                        lock_basic_lock(&x->lock);
                }
                if(!auth_xfer_setup(z, x)) {
                        if(x) {
                                lock_basic_unlock(&x->lock);
                        }
                        lock_rw_unlock(&z->lock);
                        lock_rw_unlock(&az->lock);
                        return 0;
                }
                if(x) {
                        lock_basic_unlock(&x->lock);
                }
                lock_rw_unlock(&z->lock);
        }
        lock_rw_unlock(&az->lock);
        return 1;
}

/** set config items and create zones */
static int
auth_zones_cfg(struct auth_zones* az, struct config_auth* c)
{
        struct auth_zone* z;
        struct auth_xfer* x = NULL;

        /* create zone */
        if(c->isrpz) {
                /* if the rpz lock is needed, grab it before the other
                 * locks to avoid a lock dependency cycle */
                lock_rw_wrlock(&az->rpz_lock);
        }
        lock_rw_wrlock(&az->lock);
        if(!(z=auth_zones_find_or_add_zone(az, c->name))) {
                lock_rw_unlock(&az->lock);
                if(c->isrpz) {
                        lock_rw_unlock(&az->rpz_lock);
                }
                return 0;
        }
        if(c->masters || c->urls) {
                if(!(x=auth_zones_find_or_add_xfer(az, z))) {
                        lock_rw_unlock(&az->lock);
                        lock_rw_unlock(&z->lock);
                        if(c->isrpz) {
                                lock_rw_unlock(&az->rpz_lock);
                        }
                        return 0;
                }
        }
        if(c->for_downstream)
                az->have_downstream = 1;
        lock_rw_unlock(&az->lock);

        /* set options */
        z->zone_deleted = 0;
        if(!auth_zone_set_zonefile(z, c->zonefile)) {
                if(x) {
                        lock_basic_unlock(&x->lock);
                }
                lock_rw_unlock(&z->lock);
                if(c->isrpz) {
                        lock_rw_unlock(&az->rpz_lock);
                }
                return 0;
        }
        z->for_downstream = c->for_downstream;
        z->for_upstream = c->for_upstream;
        z->fallback_enabled = c->fallback_enabled;
        z->zonemd_check = c->zonemd_check;
        z->zonemd_reject_absence = c->zonemd_reject_absence;
        if(c->isrpz && !z->rpz){
                if(!(z->rpz = rpz_create(c))){
                        fatal_exit("Could not setup RPZ zones");
                        return 0;
                }
                lock_protect(&z->lock, &z->rpz->local_zones, sizeof(*z->rpz));
                /* the az->rpz_lock is locked above */
                z->rpz_az_next = az->rpz_first;
                if(az->rpz_first)
                        az->rpz_first->rpz_az_prev = z;
                az->rpz_first = z;
        } else if(c->isrpz && z->rpz) {
                if(!rpz_config(z->rpz, c)) {
                        log_err("Could not change rpz config");
                        if(x) {
                                lock_basic_unlock(&x->lock);
                        }
                        lock_rw_unlock(&z->lock);
                        lock_rw_unlock(&az->rpz_lock);
                        return 0;
                }
        }
        if(c->isrpz) {
                lock_rw_unlock(&az->rpz_lock);
        }

        /* xfer zone */
        if(x) {
                z->zone_is_slave = 1;
                /* set options on xfer zone */
                if(!xfer_set_masters(&x->task_probe->masters, c, 0)) {
                        lock_basic_unlock(&x->lock);
                        lock_rw_unlock(&z->lock);
                        return 0;
                }
                if(!xfer_set_masters(&x->task_transfer->masters, c, 1)) {
                        lock_basic_unlock(&x->lock);
                        lock_rw_unlock(&z->lock);
                        return 0;
                }
                lock_basic_unlock(&x->lock);
        }

        lock_rw_unlock(&z->lock);
        return 1;
}

/** set all auth zones deleted, then in auth_zones_cfg, it marks them
 * as nondeleted (if they are still in the config), and then later
 * we can find deleted zones */
static void
az_setall_deleted(struct auth_zones* az)
{
        struct auth_zone* z;
        lock_rw_wrlock(&az->lock);
        RBTREE_FOR(z, struct auth_zone*, &az->ztree) {
                lock_rw_wrlock(&z->lock);
                z->zone_deleted = 1;
                lock_rw_unlock(&z->lock);
        }
        lock_rw_unlock(&az->lock);
}

/** find zones that are marked deleted and delete them.
 * This is called from apply_cfg, and there are no threads and no
 * workers, so the xfr can just be deleted. */
static void
az_delete_deleted_zones(struct auth_zones* az)
{
        struct auth_zone* z;
        struct auth_zone* delete_list = NULL, *next;
        struct auth_xfer* xfr;
        lock_rw_wrlock(&az->lock);
        RBTREE_FOR(z, struct auth_zone*, &az->ztree) {
                lock_rw_wrlock(&z->lock);
                if(z->zone_deleted) {
                        /* we cannot alter the rbtree right now, but
                         * we can put it on a linked list and then
                         * delete it */
                        z->delete_next = delete_list;
                        delete_list = z;
                }
                lock_rw_unlock(&z->lock);
        }
        /* now we are out of the tree loop and we can loop and delete
         * the zones */
        z = delete_list;
        while(z) {
                next = z->delete_next;
                xfr = auth_xfer_find(az, z->name, z->namelen, z->dclass);
                if(xfr) {
                        (void)rbtree_delete(&az->xtree, &xfr->node);
                        auth_xfer_delete(xfr);
                }
                (void)rbtree_delete(&az->ztree, &z->node);
                auth_zone_delete(z, az);
                z = next;
        }
        lock_rw_unlock(&az->lock);
}

int auth_zones_apply_cfg(struct auth_zones* az, struct config_file* cfg,
        int setup, int* is_rpz, struct module_env* env,
        struct module_stack* mods)
{
        struct config_auth* p;
        az_setall_deleted(az);
        for(p = cfg->auths; p; p = p->next) {
                if(!p->name || p->name[0] == 0) {
                        log_warn("auth-zone without a name, skipped");
                        continue;
                }
                *is_rpz = (*is_rpz || p->isrpz);
                if(!auth_zones_cfg(az, p)) {
                        log_err("cannot config auth zone %s", p->name);
                        return 0;
                }
        }
        az_delete_deleted_zones(az);
        if(!auth_zones_read_zones(az, cfg, env, mods))
                return 0;
        if(setup) {
                if(!auth_zones_setup_zones(az))
                        return 0;
        }
        return 1;
}

/** delete chunks
 * @param at: transfer structure with chunks list.  The chunks and their
 *      data are freed.
 */
static void
auth_chunks_delete(struct auth_transfer* at)
{
        if(at->chunks_first) {
                struct auth_chunk* c, *cn;
                c = at->chunks_first;
                while(c) {
                        cn = c->next;
                        free(c->data);
                        free(c);
                        c = cn;
                }
        }
        at->chunks_first = NULL;
        at->chunks_last = NULL;
}

/** free master addr list */
static void
auth_free_master_addrs(struct auth_addr* list)
{
        struct auth_addr *n;
        while(list) {
                n = list->next;
                free(list);
                list = n;
        }
}

/** free the masters list */
static void
auth_free_masters(struct auth_master* list)
{
        struct auth_master* n;
        while(list) {
                n = list->next;
                auth_free_master_addrs(list->list);
                free(list->host);
                free(list->file);
                free(list);
                list = n;
        }
}

/** delete auth xfer structure
 * @param xfr: delete this xfer and its tasks.
 */
void
auth_xfer_delete(struct auth_xfer* xfr)
{
        if(!xfr) return;
        lock_basic_destroy(&xfr->lock);
        free(xfr->name);
        if(xfr->task_nextprobe) {
                comm_timer_delete(xfr->task_nextprobe->timer);
                free(xfr->task_nextprobe);
        }
        if(xfr->task_probe) {
                auth_free_masters(xfr->task_probe->masters);
                comm_point_delete(xfr->task_probe->cp);
                comm_timer_delete(xfr->task_probe->timer);
                free(xfr->task_probe);
        }
        if(xfr->task_transfer) {
                auth_free_masters(xfr->task_transfer->masters);
                comm_point_delete(xfr->task_transfer->cp);
                comm_timer_delete(xfr->task_transfer->timer);
                if(xfr->task_transfer->chunks_first) {
                        auth_chunks_delete(xfr->task_transfer);
                }
                free(xfr->task_transfer);
        }
        auth_free_masters(xfr->allow_notify_list);
        free(xfr);
}

/** helper traverse to delete zones */
static void
auth_zone_del(rbnode_type* n, void* ATTR_UNUSED(arg))
{
        struct auth_zone* z = (struct auth_zone*)n->key;
        auth_zone_delete(z, NULL);
}

/** helper traverse to delete xfer zones */
static void
auth_xfer_del(rbnode_type* n, void* ATTR_UNUSED(arg))
{
        struct auth_xfer* z = (struct auth_xfer*)n->key;
        auth_xfer_delete(z);
}

void auth_zones_delete(struct auth_zones* az)
{
        if(!az) return;
        lock_rw_destroy(&az->lock);
        lock_rw_destroy(&az->rpz_lock);
        traverse_postorder(&az->ztree, auth_zone_del, NULL);
        traverse_postorder(&az->xtree, auth_xfer_del, NULL);
        free(az);
}

/** true if domain has only nsec3 */
static int
domain_has_only_nsec3(struct auth_data* n)
{
        struct auth_rrset* rrset = n->rrsets;
        int nsec3_seen = 0;
        while(rrset) {
                if(rrset->type == LDNS_RR_TYPE_NSEC3) {
                        nsec3_seen = 1;
                } else if(rrset->type != LDNS_RR_TYPE_RRSIG) {
                        return 0;
                }
                rrset = rrset->next;
        }
        return nsec3_seen;
}

/** see if the domain has a wildcard child '*.domain' */
static struct auth_data*
az_find_wildcard_domain(struct auth_zone* z, uint8_t* nm, size_t nmlen)
{
        uint8_t wc[LDNS_MAX_DOMAINLEN];
        if(nmlen+2 > sizeof(wc))
                return NULL; /* result would be too long */
        wc[0] = 1; /* length of wildcard label */
        wc[1] = (uint8_t)'*'; /* wildcard label */
        memmove(wc+2, nm, nmlen);
        return az_find_name(z, wc, nmlen+2);
}

/** find wildcard between qname and cename */
static struct auth_data*
az_find_wildcard(struct auth_zone* z, struct query_info* qinfo,
        struct auth_data* ce)
{
        uint8_t* nm = qinfo->qname;
        size_t nmlen = qinfo->qname_len;
        struct auth_data* node;
        if(!dname_subdomain_c(nm, z->name))
                return NULL; /* out of zone */
        while((node=az_find_wildcard_domain(z, nm, nmlen))==NULL) {
                /* see if we can go up to find the wildcard */
                if(nmlen == z->namelen)
                        return NULL; /* top of zone reached */
                if(ce && nmlen == ce->namelen)
                        return NULL; /* ce reached */
                if(dname_is_root(nm))
                        return NULL; /* cannot go up */
                dname_remove_label(&nm, &nmlen);
        }
        return node;
}

/** domain is not exact, find first candidate ce (name that matches
 * a part of qname) in tree */
static struct auth_data*
az_find_candidate_ce(struct auth_zone* z, struct query_info* qinfo,
        struct auth_data* n)
{
        uint8_t* nm;
        size_t nmlen;
        if(n) {
                nm = dname_get_shared_topdomain(qinfo->qname, n->name);
        } else {
                nm = qinfo->qname;
        }
        dname_count_size_labels(nm, &nmlen);
        n = az_find_name(z, nm, nmlen);
        /* delete labels and go up on name */
        while(!n) {
                if(dname_is_root(nm))
                        return NULL; /* cannot go up */
                dname_remove_label(&nm, &nmlen);
                n = az_find_name(z, nm, nmlen);
        }
        return n;
}

/** go up the auth tree to next existing name. */
static struct auth_data*
az_domain_go_up(struct auth_zone* z, struct auth_data* n)
{
        uint8_t* nm = n->name;
        size_t nmlen = n->namelen;
        while(!dname_is_root(nm)) {
                dname_remove_label(&nm, &nmlen);
                if((n=az_find_name(z, nm, nmlen)) != NULL)
                        return n;
        }
        return NULL;
}

/** Find the closest encloser, an name that exists and is above the
 * qname.
 * return true if the node (param node) is existing, nonobscured and
 *      can be used to generate answers from.  It is then also node_exact.
 * returns false if the node is not good enough (or it wasn't node_exact)
 *      in this case the ce can be filled.
 *      if ce is NULL, no ce exists, and likely the zone is completely empty,
 *      not even with a zone apex.
 *      if ce is nonNULL it is the closest enclosing upper name (that exists
 *      itself for answer purposes).  That name may have DNAME, NS or wildcard
 *      rrset is the closest DNAME or NS rrset that was found.
 */
static int
az_find_ce(struct auth_zone* z, struct query_info* qinfo,
        struct auth_data* node, int node_exact, struct auth_data** ce,
        struct auth_rrset** rrset)
{
        struct auth_data* n = node;
        struct auth_rrset* lookrrset;
        *ce = NULL;
        *rrset = NULL;
        if(!node_exact) {
                /* if not exact, lookup closest exact match */
                n = az_find_candidate_ce(z, qinfo, n);
        } else {
                /* if exact, the node itself is the first candidate ce */
                *ce = n;
        }

        /* no direct answer from nsec3-only domains */
        if(n && domain_has_only_nsec3(n)) {
                node_exact = 0;
                *ce = NULL;
        }

        /* with exact matches, walk up the labels until we find the
         * delegation, or DNAME or zone end */
        while(n) {
                /* see if the current candidate has issues */
                /* not zone apex and has type NS */
                if(n->namelen != z->namelen &&
                        (lookrrset=az_domain_rrset(n, LDNS_RR_TYPE_NS)) &&
                        /* delegate here, but DS at exact the dp has notype */
                        (qinfo->qtype != LDNS_RR_TYPE_DS || 
                        n->namelen != qinfo->qname_len)) {
                        /* referral */
                        /* this is ce and the lowernode is nonexisting */
                        *ce = n;
                        *rrset = lookrrset;
                        node_exact = 0;
                }
                /* not equal to qname and has type DNAME */
                if(n->namelen != qinfo->qname_len &&
                        (lookrrset=az_domain_rrset(n, LDNS_RR_TYPE_DNAME))) {
                        /* this is ce and the lowernode is nonexisting */
                        *ce = n;
                        *rrset = lookrrset;
                        node_exact = 0;
                }

                if(*ce == NULL && !domain_has_only_nsec3(n)) {
                        /* if not found yet, this exact name must be
                         * our lowest match (but not nsec3onlydomain) */
                        *ce = n;
                }

                /* walk up the tree by removing labels from name and lookup */
                n = az_domain_go_up(z, n);
        }
        /* found no problems, if it was an exact node, it is fine to use */
        return node_exact;
}

/** add additional A/AAAA from domain names in rrset rdata (+offset)
 * offset is number of bytes in rdata where the dname is located. */
static int
az_add_additionals_from(struct auth_zone* z, struct regional* region,
        struct dns_msg* msg, struct auth_rrset* rrset, size_t offset)
{
        struct packed_rrset_data* d = rrset->data;
        size_t i;
        if(!d) return 0;
        for(i=0; i<d->count; i++) {
                size_t dlen;
                struct auth_data* domain;
                struct auth_rrset* ref;
                if(d->rr_len[i] < 2+offset)
                        continue; /* too short */
                if(!(dlen = dname_valid(d->rr_data[i]+2+offset,
                        d->rr_len[i]-2-offset)))
                        continue; /* malformed */
                domain = az_find_name(z, d->rr_data[i]+2+offset, dlen);
                if(!domain)
                        continue;
                if((ref=az_domain_rrset(domain, LDNS_RR_TYPE_A)) != NULL) {
                        if(!msg_add_rrset_ar(z, region, msg, domain, ref))
                                return 0;
                }
                if((ref=az_domain_rrset(domain, LDNS_RR_TYPE_AAAA)) != NULL) {
                        if(!msg_add_rrset_ar(z, region, msg, domain, ref))
                                return 0;
                }
        }
        return 1;
}

/** add negative SOA record (with negative TTL) */
static int
az_add_negative_soa(struct auth_zone* z, struct regional* region,
        struct dns_msg* msg)
{
        time_t minimum;
        size_t i;
        struct packed_rrset_data* d;
        struct auth_rrset* soa;
        struct auth_data* apex = az_find_name(z, z->name, z->namelen);
        if(!apex) return 0;
        soa = az_domain_rrset(apex, LDNS_RR_TYPE_SOA);
        if(!soa) return 0;
        /* must be first to put in message; we want to fix the TTL with
         * one RRset here, otherwise we'd need to loop over the RRs to get
         * the resulting lower TTL */
        log_assert(msg->rep->rrset_count == 0);
        if(!msg_add_rrset_ns(z, region, msg, apex, soa)) return 0;
        /* fixup TTL */
        d = (struct packed_rrset_data*)msg->rep->rrsets[msg->rep->rrset_count-1]->entry.data;
        /* last 4 bytes are minimum ttl in network format */
        if(d->count == 0) return 0;
        if(d->rr_len[0] < 2+4) return 0;
        minimum = (time_t)sldns_read_uint32(d->rr_data[0]+(d->rr_len[0]-4));
        minimum = d->ttl<minimum?d->ttl:minimum;
        d->ttl = minimum;
        for(i=0; i < d->count + d->rrsig_count; i++)
                d->rr_ttl[i] = minimum;
        msg->rep->ttl = get_rrset_ttl(msg->rep->rrsets[0]);
        msg->rep->prefetch_ttl = PREFETCH_TTL_CALC(msg->rep->ttl);
        msg->rep->serve_expired_ttl = msg->rep->ttl + SERVE_EXPIRED_TTL;
        return 1;
}

/** See if the query goes to empty nonterminal (that has no auth_data,
 * but there are nodes underneath.  We already checked that there are
 * not NS, or DNAME above, so that we only need to check if some node
 * exists below (with nonempty rr list), return true if emptynonterminal */
static int
az_empty_nonterminal(struct auth_zone* z, struct query_info* qinfo,
        struct auth_data* node)
{
        struct auth_data* next;
        if(!node) {
                /* no smaller was found, use first (smallest) node as the
                 * next one */
                next = (struct auth_data*)rbtree_first(&z->data);
        } else {
                next = (struct auth_data*)rbtree_next(&node->node);
        }
        while(next && (rbnode_type*)next != RBTREE_NULL && next->rrsets == NULL) {
                /* the next name has empty rrsets, is an empty nonterminal
                 * itself, see if there exists something below it */
                next = (struct auth_data*)rbtree_next(&node->node);
        }
        if((rbnode_type*)next == RBTREE_NULL || !next) {
                /* there is no next node, so something below it cannot
                 * exist */
                return 0;
        }
        /* a next node exists, if there was something below the query,
         * this node has to be it.  See if it is below the query name */
        if(dname_strict_subdomain_c(next->name, qinfo->qname))
                return 1;
        return 0;
}

/** create synth cname target name in buffer, or fail if too long */
static size_t
synth_cname_buf(uint8_t* qname, size_t qname_len, size_t dname_len,
        uint8_t* dtarg, size_t dtarglen, uint8_t* buf, size_t buflen)
{
        size_t newlen = qname_len + dtarglen - dname_len;
        if(newlen > buflen) {
                /* YXDOMAIN error */
                return 0;
        }
        /* new name is concatenation of qname front (without DNAME owner)
         * and DNAME target name */
        memcpy(buf, qname, qname_len-dname_len);
        memmove(buf+(qname_len-dname_len), dtarg, dtarglen);
        return newlen;
}

/** create synthetic CNAME rrset for in a DNAME answer in region,
 * false on alloc failure, cname==NULL when name too long. */
static int
create_synth_cname(uint8_t* qname, size_t qname_len, struct regional* region,
        struct auth_data* node, struct auth_rrset* dname, uint16_t dclass,
        struct ub_packed_rrset_key** cname)
{
        uint8_t buf[LDNS_MAX_DOMAINLEN];
        uint8_t* dtarg;
        size_t dtarglen, newlen;
        struct packed_rrset_data* d;

        /* get DNAME target name */
        if(dname->data->count < 1) return 0;
        if(dname->data->rr_len[0] < 3) return 0; /* at least rdatalen +1 */
        dtarg = dname->data->rr_data[0]+2;
        dtarglen = dname->data->rr_len[0]-2;
        if(sldns_read_uint16(dname->data->rr_data[0]) != dtarglen)
                return 0; /* rdatalen in DNAME rdata is malformed */
        if(dname_valid(dtarg, dtarglen) != dtarglen)
                return 0; /* DNAME RR has malformed rdata */
        if(qname_len == 0)
                return 0; /* too short */
        if(qname_len <= node->namelen)
                return 0; /* qname too short for dname removal */

        /* synthesize a CNAME */
        newlen = synth_cname_buf(qname, qname_len, node->namelen,
                dtarg, dtarglen, buf, sizeof(buf));
        if(newlen == 0) {
                /* YXDOMAIN error */
                *cname = NULL;
                return 1;
        }
        *cname = (struct ub_packed_rrset_key*)regional_alloc(region,
                sizeof(struct ub_packed_rrset_key));
        if(!*cname)
                return 0; /* out of memory */
        memset(&(*cname)->entry, 0, sizeof((*cname)->entry));
        (*cname)->entry.key = (*cname);
        (*cname)->rk.type = htons(LDNS_RR_TYPE_CNAME);
        (*cname)->rk.rrset_class = htons(dclass);
        (*cname)->rk.flags = 0;
        (*cname)->rk.dname = regional_alloc_init(region, qname, qname_len);
        if(!(*cname)->rk.dname)
                return 0; /* out of memory */
        (*cname)->rk.dname_len = qname_len;
        (*cname)->entry.hash = rrset_key_hash(&(*cname)->rk);
        d = (struct packed_rrset_data*)regional_alloc_zero(region,
                sizeof(struct packed_rrset_data) + sizeof(size_t) +
                sizeof(uint8_t*) + sizeof(time_t) + sizeof(uint16_t)
                + newlen);
        if(!d)
                return 0; /* out of memory */
        (*cname)->entry.data = d;
        d->ttl = dname->data->ttl; /* RFC6672: synth CNAME TTL == DNAME TTL */
        d->count = 1;
        d->rrsig_count = 0;
        d->trust = rrset_trust_ans_noAA;
        d->rr_len = (size_t*)((uint8_t*)d +
                sizeof(struct packed_rrset_data));
        d->rr_len[0] = newlen + sizeof(uint16_t);
        packed_rrset_ptr_fixup(d);
        d->rr_ttl[0] = d->ttl;
        sldns_write_uint16(d->rr_data[0], newlen);
        memmove(d->rr_data[0] + sizeof(uint16_t), buf, newlen);
        return 1;
}

/** add a synthesized CNAME to the answer section */
static int
add_synth_cname(struct auth_zone* z, uint8_t* qname, size_t qname_len,
        struct regional* region, struct dns_msg* msg, struct auth_data* dname,
        struct auth_rrset* rrset)
{
        struct ub_packed_rrset_key* cname;
        /* synthesize a CNAME */
        if(!create_synth_cname(qname, qname_len, region, dname, rrset,
                z->dclass, &cname)) {
                /* out of memory */
                return 0;
        }
        if(!cname) {
                /* cname cannot be create because of YXDOMAIN */
                msg->rep->flags |= LDNS_RCODE_YXDOMAIN;
                return 1;
        }
        /* add cname to message */
        if(!msg_grow_array(region, msg))
                return 0;
        msg->rep->rrsets[msg->rep->rrset_count] = cname;
        msg->rep->rrset_count++;
        msg->rep->an_numrrsets++;
        msg_ttl(msg);
        return 1;
}

/** Change a dname to a different one, for wildcard namechange */
static void
az_change_dnames(struct dns_msg* msg, uint8_t* oldname, uint8_t* newname,
        size_t newlen, int an_only)
{
        size_t i;
        size_t start = 0, end = msg->rep->rrset_count;
        if(!an_only) start = msg->rep->an_numrrsets;
        if(an_only) end = msg->rep->an_numrrsets;
        for(i=start; i<end; i++) {
                /* allocated in region so we can change the ptrs */
                if(query_dname_compare(msg->rep->rrsets[i]->rk.dname, oldname)
                        == 0) {
                        msg->rep->rrsets[i]->rk.dname = newname;
                        msg->rep->rrsets[i]->rk.dname_len = newlen;
                        msg->rep->rrsets[i]->entry.hash = rrset_key_hash(&msg->rep->rrsets[i]->rk);
                }
        }
}

/** find NSEC record covering the query */
static struct auth_rrset*
az_find_nsec_cover(struct auth_zone* z, struct auth_data** node)
{
        uint8_t* nm = (*node)->name;
        size_t nmlen = (*node)->namelen;
        struct auth_rrset* rrset;
        /* find the NSEC for the smallest-or-equal node */
        /* if node == NULL, we did not find a smaller name.  But the zone
         * name is the smallest name and should have an NSEC. So there is
         * no NSEC to return (for a properly signed zone) */
        /* for empty nonterminals, the auth-data node should not exist,
         * and thus we don't need to go rbtree_previous here to find
         * a domain with an NSEC record */
        /* but there could be glue, and if this is node, then it has no NSEC.
         * Go up to find nonglue (previous) NSEC-holding nodes */
        while((rrset=az_domain_rrset(*node, LDNS_RR_TYPE_NSEC)) == NULL) {
                if(dname_is_root(nm)) return NULL;
                if(nmlen == z->namelen) return NULL;
                dname_remove_label(&nm, &nmlen);
                /* adjust *node for the nsec rrset to find in */
                *node = az_find_name(z, nm, nmlen);
        }
        return rrset;
}

/** Find NSEC and add for wildcard denial */
static int
az_nsec_wildcard_denial(struct auth_zone* z, struct regional* region,
        struct dns_msg* msg, uint8_t* cenm, size_t cenmlen)
{
        struct query_info qinfo;
        int node_exact;
        struct auth_data* node;
        struct auth_rrset* nsec;
        uint8_t wc[LDNS_MAX_DOMAINLEN];
        if(cenmlen+2 > sizeof(wc))
                return 0; /* result would be too long */
        wc[0] = 1; /* length of wildcard label */
        wc[1] = (uint8_t)'*'; /* wildcard label */
        memmove(wc+2, cenm, cenmlen);

        /* we have '*.ce' in wc wildcard name buffer */
        /* get nsec cover for that */
        qinfo.qname = wc;
        qinfo.qname_len = cenmlen+2;
        qinfo.qtype = 0;
        qinfo.qclass = 0;
        az_find_domain(z, &qinfo, &node_exact, &node);
        if((nsec=az_find_nsec_cover(z, &node)) != NULL) {
                if(!msg_add_rrset_ns(z, region, msg, node, nsec)) return 0;
        }
        return 1;
}

/** Find the NSEC3PARAM rrset (if any) and if true you have the parameters */
static int
az_nsec3_param(struct auth_zone* z, int* algo, size_t* iter, uint8_t** salt,
        size_t* saltlen)
{
        struct auth_data* apex;
        struct auth_rrset* param;
        size_t i;
        apex = az_find_name(z, z->name, z->namelen);
        if(!apex) return 0;
        param = az_domain_rrset(apex, LDNS_RR_TYPE_NSEC3PARAM);
        if(!param || param->data->count==0)
                return 0; /* no RRset or no RRs in rrset */
        /* find out which NSEC3PARAM RR has supported parameters */
        /* skip unknown flags (dynamic signer is recalculating nsec3 chain) */
        for(i=0; i<param->data->count; i++) {
                uint8_t* rdata = param->data->rr_data[i]+2;
                size_t rdatalen = param->data->rr_len[i];
                if(rdatalen < 2+5)
                        continue; /* too short */
                if(!nsec3_hash_algo_size_supported((int)(rdata[0])))
                        continue; /* unsupported algo */
                if(rdatalen < (size_t)(2+5+(size_t)rdata[4]))
                        continue; /* salt missing */
                if((rdata[1]&NSEC3_UNKNOWN_FLAGS)!=0)
                        continue; /* unknown flags */
                *algo = (int)(rdata[0]);
                *iter = sldns_read_uint16(rdata+2);
                *saltlen = rdata[4];
                if(*saltlen == 0)
                        *salt = NULL;
                else    *salt = rdata+5;
                return 1;
        }
        /* no supported params */
        return 0;
}

/** Hash a name with nsec3param into buffer, it has zone name appended.
 * return length of hash */
static size_t
az_nsec3_hash(uint8_t* buf, size_t buflen, uint8_t* nm, size_t nmlen,
        int algo, size_t iter, uint8_t* salt, size_t saltlen)
{
        size_t hlen = nsec3_hash_algo_size_supported(algo);
        /* buffer has domain name, nsec3hash, and 256 is for max saltlen
         * (salt has 0-255 length) */
        unsigned char p[LDNS_MAX_DOMAINLEN+1+N3HASHBUFLEN+256];
        size_t i;
        if(nmlen+saltlen > sizeof(p) || hlen+saltlen > sizeof(p))
                return 0;
        if(hlen > buflen)
                return 0; /* somehow too large for destination buffer */
        /* hashfunc(name, salt) */
        memmove(p, nm, nmlen);
        query_dname_tolower(p);
        if(salt && saltlen > 0)
                memmove(p+nmlen, salt, saltlen);
        (void)secalgo_nsec3_hash(algo, p, nmlen+saltlen, (unsigned char*)buf);
        for(i=0; i<iter; i++) {
                /* hashfunc(hash, salt) */
                memmove(p, buf, hlen);
                if(salt && saltlen > 0)
                        memmove(p+hlen, salt, saltlen);
                (void)secalgo_nsec3_hash(algo, p, hlen+saltlen,
                        (unsigned char*)buf);
        }
        return hlen;
}

/** Hash name and return b32encoded hashname for lookup, zone name appended */
static int
az_nsec3_hashname(struct auth_zone* z, uint8_t* hashname, size_t* hashnmlen,
        uint8_t* nm, size_t nmlen, int algo, size_t iter, uint8_t* salt,
        size_t saltlen)
{
        uint8_t hash[N3HASHBUFLEN];
        size_t hlen;
        int ret;
        hlen = az_nsec3_hash(hash, sizeof(hash), nm, nmlen, algo, iter,
                salt, saltlen);
        if(!hlen) return 0;
        /* b32 encode */
        if(*hashnmlen < hlen*2+1+z->namelen) /* approx b32 as hexb16 */
                return 0;
        ret = sldns_b32_ntop_extended_hex(hash, hlen, (char*)(hashname+1),
                (*hashnmlen)-1);
        if(ret<1)
                return 0;
        hashname[0] = (uint8_t)ret;
        ret++;
        if((*hashnmlen) - ret < z->namelen)
                return 0;
        memmove(hashname+ret, z->name, z->namelen);
        *hashnmlen = z->namelen+(size_t)ret;
        return 1;
}

/** Find the datanode that covers the nsec3hash-name */
static struct auth_data*
az_nsec3_findnode(struct auth_zone* z, uint8_t* hashnm, size_t hashnmlen)
{
        struct query_info qinfo;
        struct auth_data* node;
        int node_exact;
        qinfo.qclass = 0;
        qinfo.qtype = 0;
        qinfo.qname = hashnm;
        qinfo.qname_len = hashnmlen;
        /* because canonical ordering and b32 nsec3 ordering are the same.
         * this is a good lookup to find the nsec3 name. */
        az_find_domain(z, &qinfo, &node_exact, &node);
        /* but we may have to skip non-nsec3 nodes */
        /* this may be a lot, the way to speed that up is to have a
         * separate nsec3 tree with nsec3 nodes */
        while(node && (rbnode_type*)node != RBTREE_NULL &&
                !az_domain_rrset(node, LDNS_RR_TYPE_NSEC3)) {
                node = (struct auth_data*)rbtree_previous(&node->node);
        }
        if((rbnode_type*)node == RBTREE_NULL)
                node = NULL;
        return node;
}

/** Find cover for hashed(nm, nmlen) (or NULL) */
static struct auth_data*
az_nsec3_find_cover(struct auth_zone* z, uint8_t* nm, size_t nmlen,
        int algo, size_t iter, uint8_t* salt, size_t saltlen)
{
        struct auth_data* node;
        uint8_t hname[LDNS_MAX_DOMAINLEN];
        size_t hlen = sizeof(hname);
        if(!az_nsec3_hashname(z, hname, &hlen, nm, nmlen, algo, iter,
                salt, saltlen))
                return NULL;
        node = az_nsec3_findnode(z, hname, hlen);
        if(node)
                return node;
        /* we did not find any, perhaps because the NSEC3 hash is before
         * the first hash, we have to find the 'last hash' in the zone */
        node = (struct auth_data*)rbtree_last(&z->data);
        while(node && (rbnode_type*)node != RBTREE_NULL &&
                !az_domain_rrset(node, LDNS_RR_TYPE_NSEC3)) {
                node = (struct auth_data*)rbtree_previous(&node->node);
        }
        if((rbnode_type*)node == RBTREE_NULL)
                node = NULL;
        return node;
}

/** Find exact match for hashed(nm, nmlen) NSEC3 record or NULL */
static struct auth_data*
az_nsec3_find_exact(struct auth_zone* z, uint8_t* nm, size_t nmlen,
        int algo, size_t iter, uint8_t* salt, size_t saltlen)
{
        struct auth_data* node;
        uint8_t hname[LDNS_MAX_DOMAINLEN];
        size_t hlen = sizeof(hname);
        if(!az_nsec3_hashname(z, hname, &hlen, nm, nmlen, algo, iter,
                salt, saltlen))
                return NULL;
        node = az_find_name(z, hname, hlen);
        if(az_domain_rrset(node, LDNS_RR_TYPE_NSEC3))
                return node;
        return NULL;
}

/** Return nextcloser name (as a ref into the qname).  This is one label
 * more than the cenm (cename must be a suffix of qname) */
static void
az_nsec3_get_nextcloser(uint8_t* cenm, uint8_t* qname, size_t qname_len,
        uint8_t** nx, size_t* nxlen)
{
        int celabs = dname_count_labels(cenm);
        int qlabs = dname_count_labels(qname);
        int strip = qlabs - celabs -1;
        log_assert(dname_strict_subdomain(qname, qlabs, cenm, celabs));
        *nx = qname;
        *nxlen = qname_len;
        if(strip>0)
                dname_remove_labels(nx, nxlen, strip);
}

/** Find the closest encloser that has exact NSEC3.
 * updated cenm to the new name. If it went up no-exact-ce is true. */
static struct auth_data*
az_nsec3_find_ce(struct auth_zone* z, uint8_t** cenm, size_t* cenmlen,
        int* no_exact_ce, int algo, size_t iter, uint8_t* salt, size_t saltlen)
{
        struct auth_data* node;
        while((node = az_nsec3_find_exact(z, *cenm, *cenmlen,
                algo, iter, salt, saltlen)) == NULL) {
                if(*cenmlen == z->namelen) {
                        /* next step up would take us out of the zone. fail */
                        return NULL;
                }
                *no_exact_ce = 1;
                dname_remove_label(cenm, cenmlen);
        }
        return node;
}

/* Insert NSEC3 record in authority section, if NULL does nothing */
static int
az_nsec3_insert(struct auth_zone* z, struct regional* region,
        struct dns_msg* msg, struct auth_data* node)
{
        struct auth_rrset* nsec3;
        if(!node) return 1; /* no node, skip this */
        nsec3 = az_domain_rrset(node, LDNS_RR_TYPE_NSEC3);
        if(!nsec3) return 1; /* if no nsec3 RR, skip it */
        if(!msg_add_rrset_ns(z, region, msg, node, nsec3)) return 0;
        return 1;
}

/** add NSEC3 records to the zone for the nsec3 proof.
 * Specify with the flags with parts of the proof are required.
 * the ce is the exact matching name (for notype) but also delegation points.
 * qname is the one where the nextcloser name can be derived from.
 * If NSEC3 is not properly there (in the zone) nothing is added.
 * always enabled: include nsec3 proving about the Closest Encloser.
 *      that is an exact match that should exist for it.
 *      If that does not exist, a higher exact match + nxproof is enabled
 *      (for some sort of opt-out empty nonterminal cases).
 * nodataproof: search for exact match and include that instead.
 * ceproof: include ce proof NSEC3 (omitted for wildcard replies).
 * nxproof: include denial of the qname.
 * wcproof: include denial of wildcard (wildcard.ce).
 */
static int
az_add_nsec3_proof(struct auth_zone* z, struct regional* region,
        struct dns_msg* msg, uint8_t* cenm, size_t cenmlen, uint8_t* qname,
        size_t qname_len, int nodataproof, int ceproof, int nxproof,
        int wcproof)
{
        int algo;
        size_t iter, saltlen;
        uint8_t* salt;
        int no_exact_ce = 0;
        struct auth_data* node;

        /* find parameters of nsec3 proof */
        if(!az_nsec3_param(z, &algo, &iter, &salt, &saltlen))
                return 1; /* no nsec3 */
        if(nodataproof) {
                /* see if the node has a hash of itself for the nodata
                 * proof nsec3, this has to be an exact match nsec3. */
                struct auth_data* match;
                match = az_nsec3_find_exact(z, qname, qname_len, algo,
                        iter, salt, saltlen);
                if(match) {
                        if(!az_nsec3_insert(z, region, msg, match))
                                return 0;
                        /* only nodata NSEC3 needed, no CE or others. */
                        return 1;
                }
        }
        /* find ce that has an NSEC3 */
        if(ceproof) {
                node = az_nsec3_find_ce(z, &cenm, &cenmlen, &no_exact_ce,
                        algo, iter, salt, saltlen);
                if(no_exact_ce) nxproof = 1;
                if(!az_nsec3_insert(z, region, msg, node))
                        return 0;
        }

        if(nxproof) {
                uint8_t* nx;
                size_t nxlen;
                /* create nextcloser domain name */
                az_nsec3_get_nextcloser(cenm, qname, qname_len, &nx, &nxlen);
                /* find nsec3 that matches or covers it */
                node = az_nsec3_find_cover(z, nx, nxlen, algo, iter, salt,
                        saltlen);
                if(!az_nsec3_insert(z, region, msg, node))
                        return 0;
        }
        if(wcproof) {
                /* create wildcard name *.ce */
                uint8_t wc[LDNS_MAX_DOMAINLEN];
                size_t wclen;
                if(cenmlen+2 > sizeof(wc))
                        return 0; /* result would be too long */
                wc[0] = 1; /* length of wildcard label */
                wc[1] = (uint8_t)'*'; /* wildcard label */
                memmove(wc+2, cenm, cenmlen);
                wclen = cenmlen+2;
                /* find nsec3 that matches or covers it */
                node = az_nsec3_find_cover(z, wc, wclen, algo, iter, salt,
                        saltlen);
                if(!az_nsec3_insert(z, region, msg, node))
                        return 0;
        }
        return 1;
}

/** generate answer for positive answer */
static int
az_generate_positive_answer(struct auth_zone* z, struct regional* region,
        struct dns_msg* msg, struct auth_data* node, struct auth_rrset* rrset)
{
        if(!msg_add_rrset_an(z, region, msg, node, rrset)) return 0;
        /* see if we want additional rrs */
        if(rrset->type == LDNS_RR_TYPE_MX) {
                if(!az_add_additionals_from(z, region, msg, rrset, 2))
                        return 0;
        } else if(rrset->type == LDNS_RR_TYPE_SRV) {
                if(!az_add_additionals_from(z, region, msg, rrset, 6))
                        return 0;
        } else if(rrset->type == LDNS_RR_TYPE_NS) {
                if(!az_add_additionals_from(z, region, msg, rrset, 0))
                        return 0;
        }
        return 1;
}

/** generate answer for type ANY answer */
static int
az_generate_any_answer(struct auth_zone* z, struct regional* region,
        struct dns_msg* msg, struct auth_data* node)
{
        struct auth_rrset* rrset;
        int added = 0;
        /* add a couple (at least one) RRs */
        if((rrset=az_domain_rrset(node, LDNS_RR_TYPE_SOA)) != NULL) {
                if(!msg_add_rrset_an(z, region, msg, node, rrset)) return 0;
                added++;
        }
        if((rrset=az_domain_rrset(node, LDNS_RR_TYPE_MX)) != NULL) {
                if(!msg_add_rrset_an(z, region, msg, node, rrset)) return 0;
                added++;
        }
        if((rrset=az_domain_rrset(node, LDNS_RR_TYPE_A)) != NULL) {
                if(!msg_add_rrset_an(z, region, msg, node, rrset)) return 0;
                added++;
        }
        if((rrset=az_domain_rrset(node, LDNS_RR_TYPE_AAAA)) != NULL) {
                if(!msg_add_rrset_an(z, region, msg, node, rrset)) return 0;
                added++;
        }
        if(added == 0 && node && node->rrsets) {
                if(!msg_add_rrset_an(z, region, msg, node,
                        node->rrsets)) return 0;
        }
        return 1;
}

/** follow cname chain and add more data to the answer section */
static int
follow_cname_chain(struct auth_zone* z, uint16_t qtype,
        struct regional* region, struct dns_msg* msg,
        struct packed_rrset_data* d)
{
        int maxchain = 0;
        /* see if we can add the target of the CNAME into the answer */
        while(maxchain++ < MAX_CNAME_CHAIN) {
                struct auth_data* node;
                struct auth_rrset* rrset;
                size_t clen;
                /* d has cname rdata */
                if(d->count == 0) break; /* no CNAME */
                if(d->rr_len[0] < 2+1) break; /* too small */
                if((clen=dname_valid(d->rr_data[0]+2, d->rr_len[0]-2))==0)
                        break; /* malformed */
                if(!dname_subdomain_c(d->rr_data[0]+2, z->name))
                        break; /* target out of zone */
                if((node = az_find_name(z, d->rr_data[0]+2, clen))==NULL)
                        break; /* no such target name */
                if((rrset=az_domain_rrset(node, qtype))!=NULL) {
                        /* done we found the target */
                        if(!msg_add_rrset_an(z, region, msg, node, rrset))
                                return 0;
                        break;
                }
                if((rrset=az_domain_rrset(node, LDNS_RR_TYPE_CNAME))==NULL)
                        break; /* no further CNAME chain, notype */
                if(!msg_add_rrset_an(z, region, msg, node, rrset)) return 0;
                d = rrset->data;
        }
        return 1;
}

/** generate answer for cname answer */
static int
az_generate_cname_answer(struct auth_zone* z, struct query_info* qinfo,
        struct regional* region, struct dns_msg* msg,
        struct auth_data* node, struct auth_rrset* rrset)
{
        if(!msg_add_rrset_an(z, region, msg, node, rrset)) return 0;
        if(!rrset) return 1;
        if(!follow_cname_chain(z, qinfo->qtype, region, msg, rrset->data))
                return 0;
        return 1;
}

/** generate answer for notype answer */
static int
az_generate_notype_answer(struct auth_zone* z, struct regional* region,
        struct dns_msg* msg, struct auth_data* node)
{
        struct auth_rrset* rrset;
        if(!az_add_negative_soa(z, region, msg)) return 0;
        /* DNSSEC denial NSEC */
        if((rrset=az_domain_rrset(node, LDNS_RR_TYPE_NSEC))!=NULL) {
                if(!msg_add_rrset_ns(z, region, msg, node, rrset)) return 0;
        } else if(node) {
                /* DNSSEC denial NSEC3 */
                if(!az_add_nsec3_proof(z, region, msg, node->name,
                        node->namelen, msg->qinfo.qname,
                        msg->qinfo.qname_len, 1, 1, 0, 0))
                        return 0;
        }
        return 1;
}

/** generate answer for referral answer */
static int
az_generate_referral_answer(struct auth_zone* z, struct regional* region,
        struct dns_msg* msg, struct auth_data* ce, struct auth_rrset* rrset)
{
        struct auth_rrset* ds, *nsec;
        /* turn off AA flag, referral is nonAA because it leaves the zone */
        log_assert(ce);
        msg->rep->flags &= ~BIT_AA;
        if(!msg_add_rrset_ns(z, region, msg, ce, rrset)) return 0;
        /* add DS or deny it */
        if((ds=az_domain_rrset(ce, LDNS_RR_TYPE_DS))!=NULL) {
                if(!msg_add_rrset_ns(z, region, msg, ce, ds)) return 0;
        } else {
                /* deny the DS */
                if((nsec=az_domain_rrset(ce, LDNS_RR_TYPE_NSEC))!=NULL) {
                        if(!msg_add_rrset_ns(z, region, msg, ce, nsec))
                                return 0;
                } else {
                        if(!az_add_nsec3_proof(z, region, msg, ce->name,
                                ce->namelen, msg->qinfo.qname,
                                msg->qinfo.qname_len, 1, 1, 0, 0))
                                return 0;
                }
        }
        /* add additional rrs for type NS */
        if(!az_add_additionals_from(z, region, msg, rrset, 0)) return 0;
        return 1;
}

/** generate answer for DNAME answer */
static int
az_generate_dname_answer(struct auth_zone* z, struct query_info* qinfo,
        struct regional* region, struct dns_msg* msg, struct auth_data* ce,
        struct auth_rrset* rrset)
{
        log_assert(ce);
        /* add the DNAME and then a CNAME */
        if(!msg_add_rrset_an(z, region, msg, ce, rrset)) return 0;
        if(!add_synth_cname(z, qinfo->qname, qinfo->qname_len, region,
                msg, ce, rrset)) return 0;
        if(FLAGS_GET_RCODE(msg->rep->flags) == LDNS_RCODE_YXDOMAIN)
                return 1;
        if(msg->rep->rrset_count == 0 ||
                !msg->rep->rrsets[msg->rep->rrset_count-1])
                return 0;
        if(!follow_cname_chain(z, qinfo->qtype, region, msg, 
                (struct packed_rrset_data*)msg->rep->rrsets[
                msg->rep->rrset_count-1]->entry.data))
                return 0;
        return 1;
}

/** generate answer for wildcard answer */
static int
az_generate_wildcard_answer(struct auth_zone* z, struct query_info* qinfo,
        struct regional* region, struct dns_msg* msg, struct auth_data* ce,
        struct auth_data* wildcard, struct auth_data* node)
{
        struct auth_rrset* rrset, *nsec;
        int insert_ce = 0;
        if((rrset=az_domain_rrset(wildcard, qinfo->qtype)) != NULL) {
                /* wildcard has type, add it */
                if(!msg_add_rrset_an(z, region, msg, wildcard, rrset))
                        return 0;
                az_change_dnames(msg, wildcard->name, msg->qinfo.qname,
                        msg->qinfo.qname_len, 1);
        } else if((rrset=az_domain_rrset(wildcard, LDNS_RR_TYPE_CNAME))!=NULL) {
                /* wildcard has cname instead, do that */
                if(!msg_add_rrset_an(z, region, msg, wildcard, rrset))
                        return 0;
                az_change_dnames(msg, wildcard->name, msg->qinfo.qname,
                        msg->qinfo.qname_len, 1);
                if(!follow_cname_chain(z, qinfo->qtype, region, msg,
                        rrset->data))
                        return 0;
        } else if(qinfo->qtype == LDNS_RR_TYPE_ANY && wildcard->rrsets) {
                /* add ANY rrsets from wildcard node */
                if(!az_generate_any_answer(z, region, msg, wildcard))
                        return 0;
                az_change_dnames(msg, wildcard->name, msg->qinfo.qname,
                        msg->qinfo.qname_len, 1);
        } else {
                /* wildcard has nodata, notype answer */
                /* call other notype routine for dnssec notype denials */
                if(!az_generate_notype_answer(z, region, msg, wildcard))
                        return 0;
                /* because the notype, there is no positive data with an
                 * RRSIG that indicates the wildcard position.  Thus the
                 * wildcard qname denial needs to have a CE nsec3. */
                insert_ce = 1;
        }

        /* ce and node for dnssec denial of wildcard original name */
        if((nsec=az_find_nsec_cover(z, &node)) != NULL) {
                if(!msg_add_rrset_ns(z, region, msg, node, nsec)) return 0;
        } else if(ce) {
                uint8_t* wildup = wildcard->name;
                size_t wilduplen= wildcard->namelen;
                dname_remove_label(&wildup, &wilduplen);
                if(!az_add_nsec3_proof(z, region, msg, wildup,
                        wilduplen, msg->qinfo.qname,
                        msg->qinfo.qname_len, 0, insert_ce, 1, 0))
                        return 0;
        }

        /* fixup name of wildcard from *.zone to qname, use already allocated
         * pointer to msg qname */
        az_change_dnames(msg, wildcard->name, msg->qinfo.qname,
                msg->qinfo.qname_len, 0);
        return 1;
}

/** generate answer for nxdomain answer */
static int
az_generate_nxdomain_answer(struct auth_zone* z, struct regional* region,
        struct dns_msg* msg, struct auth_data* ce, struct auth_data* node)
{
        struct auth_rrset* nsec;
        msg->rep->flags |= LDNS_RCODE_NXDOMAIN;
        if(!az_add_negative_soa(z, region, msg)) return 0;
        if((nsec=az_find_nsec_cover(z, &node)) != NULL) {
                if(!msg_add_rrset_ns(z, region, msg, node, nsec)) return 0;
                if(ce && !az_nsec_wildcard_denial(z, region, msg, ce->name,
                        ce->namelen)) return 0;
        } else if(ce) {
                if(!az_add_nsec3_proof(z, region, msg, ce->name,
                        ce->namelen, msg->qinfo.qname,
                        msg->qinfo.qname_len, 0, 1, 1, 1))
                        return 0;
        }
        return 1;
}

/** Create answers when an exact match exists for the domain name */
static int
az_generate_answer_with_node(struct auth_zone* z, struct query_info* qinfo,
        struct regional* region, struct dns_msg* msg, struct auth_data* node)
{
        struct auth_rrset* rrset;
        /* positive answer, rrset we are looking for exists */
        if((rrset=az_domain_rrset(node, qinfo->qtype)) != NULL) {
                return az_generate_positive_answer(z, region, msg, node, rrset);
        }
        /* CNAME? */
        if((rrset=az_domain_rrset(node, LDNS_RR_TYPE_CNAME)) != NULL) {
                return az_generate_cname_answer(z, qinfo, region, msg,
                        node, rrset);
        }
        /* type ANY ? */
        if(qinfo->qtype == LDNS_RR_TYPE_ANY) {
                return az_generate_any_answer(z, region, msg, node);
        }
        /* NOERROR/NODATA (no such type at domain name) */
        return az_generate_notype_answer(z, region, msg, node);
}

/** Generate answer without an existing-node that we can use.
 * So it'll be a referral, DNAME or nxdomain */
static int
az_generate_answer_nonexistnode(struct auth_zone* z, struct query_info* qinfo,
        struct regional* region, struct dns_msg* msg, struct auth_data* ce,
        struct auth_rrset* rrset, struct auth_data* node)
{
        struct auth_data* wildcard;

        /* we do not have an exact matching name (that exists) */
        /* see if we have a NS or DNAME in the ce */
        if(ce && rrset && rrset->type == LDNS_RR_TYPE_NS) {
                return az_generate_referral_answer(z, region, msg, ce, rrset);
        }
        if(ce && rrset && rrset->type == LDNS_RR_TYPE_DNAME) {
                return az_generate_dname_answer(z, qinfo, region, msg, ce,
                        rrset);
        }
        /* if there is an empty nonterminal, wildcard and nxdomain don't
         * happen, it is a notype answer */
        if(az_empty_nonterminal(z, qinfo, node)) {
                return az_generate_notype_answer(z, region, msg, node);
        }
        /* see if we have a wildcard under the ce */
        if((wildcard=az_find_wildcard(z, qinfo, ce)) != NULL) {
                return az_generate_wildcard_answer(z, qinfo, region, msg,
                        ce, wildcard, node);
        }
        /* generate nxdomain answer */
        return az_generate_nxdomain_answer(z, region, msg, ce, node);
}

/** Lookup answer in a zone. */
static int
auth_zone_generate_answer(struct auth_zone* z, struct query_info* qinfo,
        struct regional* region, struct dns_msg** msg, int* fallback)
{
        struct auth_data* node, *ce;
        struct auth_rrset* rrset;
        int node_exact, node_exists;
        /* does the zone want fallback in case of failure? */
        *fallback = z->fallback_enabled;
        if(!(*msg=msg_create(region, qinfo))) return 0;

        /* lookup if there is a matching domain name for the query */
        az_find_domain(z, qinfo, &node_exact, &node);

        /* see if node exists for generating answers from (i.e. not glue and
         * obscured by NS or DNAME or NSEC3-only), and also return the
         * closest-encloser from that, closest node that should be used
         * to generate answers from that is above the query */
        node_exists = az_find_ce(z, qinfo, node, node_exact, &ce, &rrset);

        if(verbosity >= VERB_ALGO) {
                char zname[256], qname[256], nname[256], cename[256],
                        tpstr[32], rrstr[32];
                sldns_wire2str_dname_buf(qinfo->qname, qinfo->qname_len, qname,
                        sizeof(qname));
                sldns_wire2str_type_buf(qinfo->qtype, tpstr, sizeof(tpstr));
                sldns_wire2str_dname_buf(z->name, z->namelen, zname,
                        sizeof(zname));
                if(node)
                        sldns_wire2str_dname_buf(node->name, node->namelen,
                                nname, sizeof(nname));
                else    snprintf(nname, sizeof(nname), "NULL");
                if(ce)
                        sldns_wire2str_dname_buf(ce->name, ce->namelen,
                                cename, sizeof(cename));
                else    snprintf(cename, sizeof(cename), "NULL");
                if(rrset) sldns_wire2str_type_buf(rrset->type, rrstr,
                        sizeof(rrstr));
                else    snprintf(rrstr, sizeof(rrstr), "NULL");
                log_info("auth_zone %s query %s %s, domain %s %s %s, "
                        "ce %s, rrset %s", zname, qname, tpstr, nname,
                        (node_exact?"exact":"notexact"),
                        (node_exists?"exist":"notexist"), cename, rrstr);
        }

        if(node_exists) {
                /* the node is fine, generate answer from node */
                return az_generate_answer_with_node(z, qinfo, region, *msg,
                        node);
        }
        return az_generate_answer_nonexistnode(z, qinfo, region, *msg,
                ce, rrset, node);
}

int auth_zones_lookup(struct auth_zones* az, struct query_info* qinfo,
        struct regional* region, struct dns_msg** msg, int* fallback,
        uint8_t* dp_nm, size_t dp_nmlen)
{
        int r;
        struct auth_zone* z;
        /* find the zone that should contain the answer. */
        lock_rw_rdlock(&az->lock);
        z = auth_zone_find(az, dp_nm, dp_nmlen, qinfo->qclass);
        if(!z) {
                lock_rw_unlock(&az->lock);
                /* no auth zone, fallback to internet */
                *fallback = 1;
                return 0;
        }
        lock_rw_rdlock(&z->lock);
        lock_rw_unlock(&az->lock);

        /* if not for upstream queries, fallback */
        if(!z->for_upstream) {
                lock_rw_unlock(&z->lock);
                *fallback = 1;
                return 0;
        }
        if(z->zone_expired) {
                *fallback = z->fallback_enabled;
                lock_rw_unlock(&z->lock);
                return 0;
        }
        /* see what answer that zone would generate */
        r = auth_zone_generate_answer(z, qinfo, region, msg, fallback);
        lock_rw_unlock(&z->lock);
        return r;
}

/** encode auth answer */
static void
auth_answer_encode(struct query_info* qinfo, struct module_env* env,
        struct edns_data* edns, struct comm_reply* repinfo, sldns_buffer* buf,
        struct regional* temp, struct dns_msg* msg)
{
        uint16_t udpsize;
        udpsize = edns->udp_size;
        edns->edns_version = EDNS_ADVERTISED_VERSION;
        edns->udp_size = EDNS_ADVERTISED_SIZE;
        edns->ext_rcode = 0;
        edns->bits &= EDNS_DO;

        if(!inplace_cb_reply_local_call(env, qinfo, NULL, msg->rep,
                (int)FLAGS_GET_RCODE(msg->rep->flags), edns, repinfo, temp, env->now_tv)
                || !reply_info_answer_encode(qinfo, msg->rep,
                *(uint16_t*)sldns_buffer_begin(buf),
                sldns_buffer_read_u16_at(buf, 2),
                buf, 0, 0, temp, udpsize, edns,
                (int)(edns->bits&EDNS_DO), 0)) {
                error_encode(buf, (LDNS_RCODE_SERVFAIL|BIT_AA), qinfo,
                        *(uint16_t*)sldns_buffer_begin(buf),
                        sldns_buffer_read_u16_at(buf, 2), edns);
        }
}

/** encode auth error answer */
static void
auth_error_encode(struct query_info* qinfo, struct module_env* env,
        struct edns_data* edns, struct comm_reply* repinfo, sldns_buffer* buf,
        struct regional* temp, int rcode)
{
        edns->edns_version = EDNS_ADVERTISED_VERSION;
        edns->udp_size = EDNS_ADVERTISED_SIZE;
        edns->ext_rcode = 0;
        edns->bits &= EDNS_DO;

        if(!inplace_cb_reply_local_call(env, qinfo, NULL, NULL,
                rcode, edns, repinfo, temp, env->now_tv))
                edns->opt_list_inplace_cb_out = NULL;
        error_encode(buf, rcode|BIT_AA, qinfo,
                *(uint16_t*)sldns_buffer_begin(buf),
                sldns_buffer_read_u16_at(buf, 2), edns);
}

int auth_zones_answer(struct auth_zones* az, struct module_env* env,
        struct query_info* qinfo, struct edns_data* edns,
        struct comm_reply* repinfo, struct sldns_buffer* buf, struct regional* temp)
{
        struct dns_msg* msg = NULL;
        struct auth_zone* z;
        int r;
        int fallback = 0;

        lock_rw_rdlock(&az->lock);
        if(!az->have_downstream) {
                /* no downstream auth zones */
                lock_rw_unlock(&az->lock);
                return 0;
        }
        if(qinfo->qtype == LDNS_RR_TYPE_DS) {
                uint8_t* delname = qinfo->qname;
                size_t delnamelen = qinfo->qname_len;
                dname_remove_label(&delname, &delnamelen);
                z = auth_zones_find_zone(az, delname, delnamelen,
                        qinfo->qclass);
        } else {
                z = auth_zones_find_zone(az, qinfo->qname, qinfo->qname_len,
                        qinfo->qclass);
        }
        if(!z) {
                /* no zone above it */
                lock_rw_unlock(&az->lock);
                return 0;
        }
        lock_rw_rdlock(&z->lock);
        lock_rw_unlock(&az->lock);
        if(!z->for_downstream) {
                lock_rw_unlock(&z->lock);
                return 0;
        }
        if(z->zone_expired) {
                if(z->fallback_enabled) {
                        lock_rw_unlock(&z->lock);
                        return 0;
                }
                lock_rw_unlock(&z->lock);
                env->mesh->num_query_authzone_down++;
                auth_error_encode(qinfo, env, edns, repinfo, buf, temp,
                        LDNS_RCODE_SERVFAIL);
                return 1;
        }

        /* answer it from zone z */
        r = auth_zone_generate_answer(z, qinfo, temp, &msg, &fallback);
        lock_rw_unlock(&z->lock);
        if(!r && fallback) {
                /* fallback to regular answering (recursive) */
                return 0;
        }
        env->mesh->num_query_authzone_down++;

        /* encode answer */
        if(!r)
                auth_error_encode(qinfo, env, edns, repinfo, buf, temp,
                        LDNS_RCODE_SERVFAIL);
        else    auth_answer_encode(qinfo, env, edns, repinfo, buf, temp, msg);

        return 1;
}

int auth_zones_can_fallback(struct auth_zones* az, uint8_t* nm, size_t nmlen,
        uint16_t dclass)
{
        int r;
        struct auth_zone* z;
        lock_rw_rdlock(&az->lock);
        z = auth_zone_find(az, nm, nmlen, dclass);
        if(!z) {
                lock_rw_unlock(&az->lock);
                /* no such auth zone, fallback */
                return 1;
        }
        lock_rw_rdlock(&z->lock);
        lock_rw_unlock(&az->lock);
        r = z->fallback_enabled || (!z->for_upstream);
        lock_rw_unlock(&z->lock);
        return r;
}

int
auth_zone_parse_notify_serial(sldns_buffer* pkt, uint32_t *serial)
{
        struct query_info q;
        uint16_t rdlen;
        memset(&q, 0, sizeof(q));
        sldns_buffer_set_position(pkt, 0);
        if(!query_info_parse(&q, pkt)) return 0;
        if(LDNS_ANCOUNT(sldns_buffer_begin(pkt)) == 0) return 0;
        /* skip name of RR in answer section */
        if(sldns_buffer_remaining(pkt) < 1) return 0;
        if(pkt_dname_len(pkt) == 0) return 0;
        /* check type */
        if(sldns_buffer_remaining(pkt) < 10 /* type,class,ttl,rdatalen*/)
                return 0;
        if(sldns_buffer_read_u16(pkt) != LDNS_RR_TYPE_SOA) return 0;
        sldns_buffer_skip(pkt, 2); /* class */
        sldns_buffer_skip(pkt, 4); /* ttl */
        rdlen = sldns_buffer_read_u16(pkt); /* rdatalen */
        if(sldns_buffer_remaining(pkt) < rdlen) return 0;
        if(rdlen < 22) return 0; /* bad soa length */
        sldns_buffer_skip(pkt, (ssize_t)(rdlen-20));
        *serial = sldns_buffer_read_u32(pkt);
        /* return true when has serial in answer section */
        return 1;
}

/** print addr to str, and if not 53, append "@port_number", for logs. */
static void addr_port_to_str(struct sockaddr_storage* addr, socklen_t addrlen,
        char* buf, size_t len)
{
        uint16_t port = 0;
        if(addr_is_ip6(addr, addrlen)) {
                struct sockaddr_in6* sa = (struct sockaddr_in6*)addr;
                port = ntohs((uint16_t)sa->sin6_port);
        } else {
                struct sockaddr_in* sa = (struct sockaddr_in*)addr;
                port = ntohs((uint16_t)sa->sin_port);
        }
        if(port == UNBOUND_DNS_PORT) {
                /* If it is port 53, print it plainly. */
                addr_to_str(addr, addrlen, buf, len);
        } else {
                char a[256];
                a[0]=0;
                addr_to_str(addr, addrlen, a, sizeof(a));
                snprintf(buf, len, "%s@%d", a, (int)port);
        }
}

/** see if addr appears in the list */
static int
addr_in_list(struct auth_addr* list, struct sockaddr_storage* addr,
        socklen_t addrlen)
{
        struct auth_addr* p;
        for(p=list; p; p=p->next) {
                if(sockaddr_cmp_addr(addr, addrlen, &p->addr, p->addrlen)==0)
                        return 1;
        }
        return 0;
}

/** check if an address matches a master specification (or one of its
 * addresses in the addr list) */
static int
addr_matches_master(struct auth_master* master, struct sockaddr_storage* addr,
        socklen_t addrlen, struct auth_master** fromhost)
{
        struct sockaddr_storage a;
        socklen_t alen = 0;
        int net = 0;
        if(addr_in_list(master->list, addr, addrlen)) {
                *fromhost = master;
                return 1;       
        }
        /* compare address (but not port number, that is the destination
         * port of the master, the port number of the received notify is
         * allowed to by any port on that master) */
        if(extstrtoaddr(master->host, &a, &alen, UNBOUND_DNS_PORT) &&
                sockaddr_cmp_addr(addr, addrlen, &a, alen)==0) {
                *fromhost = master;
                return 1;
        }
        /* prefixes, addr/len, like 10.0.0.0/8 */
        /* not http and has a / and there is one / */
        if(master->allow_notify && !master->http &&
                strchr(master->host, '/') != NULL &&
                strchr(master->host, '/') == strrchr(master->host, '/') &&
                netblockstrtoaddr(master->host, UNBOUND_DNS_PORT, &a, &alen,
                &net) && alen == addrlen) {
                if(addr_in_common(addr, (addr_is_ip6(addr, addrlen)?128:32),
                        &a, net, alen) >= net) {
                        *fromhost = NULL; /* prefix does not have destination
                                to send the probe or transfer with */
                        return 1; /* matches the netblock */
                }
        }
        return 0;
}

/** check access list for notifies */
static int
az_xfr_allowed_notify(struct auth_xfer* xfr, struct sockaddr_storage* addr,
        socklen_t addrlen, struct auth_master** fromhost)
{
        struct auth_master* p;
        for(p=xfr->allow_notify_list; p; p=p->next) {
                if(addr_matches_master(p, addr, addrlen, fromhost)) {
                        return 1;
                }
        }
        return 0;
}

/** see if the serial means the zone has to be updated, i.e. the serial
 * is newer than the zone serial, or we have no zone */
static int
xfr_serial_means_update(struct auth_xfer* xfr, uint32_t serial)
{
        if(!xfr->have_zone)
                return 1; /* no zone, anything is better */
        if(xfr->zone_expired)
                return 1; /* expired, the sent serial is better than expired
                        data */
        if(compare_serial(xfr->serial, serial) < 0)
                return 1; /* our serial is smaller than the sent serial,
                        the data is newer, fetch it */
        return 0;
}

/** note notify serial, updates the notify information in the xfr struct */
static void
xfr_note_notify_serial(struct auth_xfer* xfr, int has_serial, uint32_t serial)
{
        if(xfr->notify_received && xfr->notify_has_serial && has_serial) {
                /* see if this serial is newer */
                if(compare_serial(xfr->notify_serial, serial) < 0)
                        xfr->notify_serial = serial;
        } else if(xfr->notify_received && xfr->notify_has_serial &&
                !has_serial) {
                /* remove serial, we have notify without serial */
                xfr->notify_has_serial = 0;
                xfr->notify_serial = 0;
        } else if(xfr->notify_received && !xfr->notify_has_serial) {
                /* we already have notify without serial, keep it
                 * that way; no serial check when current operation
                 * is done */
        } else {
                xfr->notify_received = 1;
                xfr->notify_has_serial = has_serial;
                xfr->notify_serial = serial;
        }
}

/** process a notify serial, start new probe or note serial. xfr is locked */
static void
xfr_process_notify(struct auth_xfer* xfr, struct module_env* env,
        int has_serial, uint32_t serial, struct auth_master* fromhost)
{
        /* if the serial of notify is older than we have, don't fetch
         * a zone, we already have it */
        if(has_serial && !xfr_serial_means_update(xfr, serial)) {
                lock_basic_unlock(&xfr->lock);
                return;
        }
        /* start new probe with this addr src, or note serial */
        if(!xfr_start_probe(xfr, env, fromhost)) {
                /* not started because already in progress, note the serial */
                xfr_note_notify_serial(xfr, has_serial, serial);
                lock_basic_unlock(&xfr->lock);
        }
        /* successful end of start_probe unlocked xfr->lock */
}

int auth_zones_notify(struct auth_zones* az, struct module_env* env,
        uint8_t* nm, size_t nmlen, uint16_t dclass,
        struct sockaddr_storage* addr, socklen_t addrlen, int has_serial,
        uint32_t serial, int* refused)
{
        struct auth_xfer* xfr;
        struct auth_master* fromhost = NULL;
        /* see which zone this is */
        lock_rw_rdlock(&az->lock);
        xfr = auth_xfer_find(az, nm, nmlen, dclass);
        if(!xfr) {
                lock_rw_unlock(&az->lock);
                /* no such zone, refuse the notify */
                *refused = 1;
                return 0;
        }
        lock_basic_lock(&xfr->lock);
        lock_rw_unlock(&az->lock);
        
        /* check access list for notifies */
        if(!az_xfr_allowed_notify(xfr, addr, addrlen, &fromhost)) {
                lock_basic_unlock(&xfr->lock);
                /* notify not allowed, refuse the notify */
                *refused = 1;
                return 0;
        }

        /* process the notify */
        xfr_process_notify(xfr, env, has_serial, serial, fromhost);
        return 1;
}

int auth_zones_startprobesequence(struct auth_zones* az,
        struct module_env* env, uint8_t* nm, size_t nmlen, uint16_t dclass)
{
        struct auth_xfer* xfr;
        lock_rw_rdlock(&az->lock);
        xfr = auth_xfer_find(az, nm, nmlen, dclass);
        if(!xfr) {
                lock_rw_unlock(&az->lock);
                return 0;
        }
        lock_basic_lock(&xfr->lock);
        lock_rw_unlock(&az->lock);

        xfr_process_notify(xfr, env, 0, 0, NULL);
        return 1;
}

/** set a zone expired */
static void
auth_xfer_set_expired(struct auth_xfer* xfr, struct module_env* env,
        int expired)
{
        struct auth_zone* z;

        /* expire xfr */
        lock_basic_lock(&xfr->lock);
        xfr->zone_expired = expired;
        lock_basic_unlock(&xfr->lock);

        /* find auth_zone */
        lock_rw_rdlock(&env->auth_zones->lock);
        z = auth_zone_find(env->auth_zones, xfr->name, xfr->namelen,
                xfr->dclass);
        if(!z) {
                lock_rw_unlock(&env->auth_zones->lock);
                return;
        }
        lock_rw_wrlock(&z->lock);
        lock_rw_unlock(&env->auth_zones->lock);

        /* expire auth_zone */
        z->zone_expired = expired;
        lock_rw_unlock(&z->lock);
}

/** find master (from notify or probe) in list of masters */
static struct auth_master*
find_master_by_host(struct auth_master* list, char* host)
{
        struct auth_master* p;
        for(p=list; p; p=p->next) {
                if(strcmp(p->host, host) == 0)
                        return p;
        }
        return NULL;
}

/** delete the looked up auth_addrs for all the masters in the list */
static void
xfr_masterlist_free_addrs(struct auth_master* list)
{
        struct auth_master* m;
        for(m=list; m; m=m->next) {
                if(m->list) {
                        auth_free_master_addrs(m->list);
                        m->list = NULL;
                }
        }
}

/** copy a list of auth_addrs */
static struct auth_addr*
auth_addr_list_copy(struct auth_addr* source)
{
        struct auth_addr* list = NULL, *last = NULL;
        struct auth_addr* p;
        for(p=source; p; p=p->next) {
                struct auth_addr* a = (struct auth_addr*)memdup(p, sizeof(*p));
                if(!a) {
                        log_err("malloc failure");
                        auth_free_master_addrs(list);
                        return NULL;
                }
                a->next = NULL;
                if(last) last->next = a;
                if(!list) list = a;
                last = a;
        }
        return list;
}

/** copy a master to a new structure, NULL on alloc failure */
static struct auth_master*
auth_master_copy(struct auth_master* o)
{
        struct auth_master* m;
        if(!o) return NULL;
        m = (struct auth_master*)memdup(o, sizeof(*o));
        if(!m) {
                log_err("malloc failure");
                return NULL;
        }
        m->next = NULL;
        if(m->host) {
                m->host = strdup(m->host);
                if(!m->host) {
                        free(m);
                        log_err("malloc failure");
                        return NULL;
                }
        }
        if(m->file) {
                m->file = strdup(m->file);
                if(!m->file) {
                        free(m->host);
                        free(m);
                        log_err("malloc failure");
                        return NULL;
                }
        }
        if(m->list) {
                m->list = auth_addr_list_copy(m->list);
                if(!m->list) {
                        free(m->file);
                        free(m->host);
                        free(m);
                        return NULL;
                }
        }
        return m;
}

/** copy the master addresses from the task_probe lookups to the allow_notify
 * list of masters */
static void
probe_copy_masters_for_allow_notify(struct auth_xfer* xfr)
{
        struct auth_master* list = NULL, *last = NULL;
        struct auth_master* p;
        /* build up new list with copies */
        for(p = xfr->task_transfer->masters; p; p=p->next) {
                struct auth_master* m = auth_master_copy(p);
                if(!m) {
                        auth_free_masters(list);
                        /* failed because of malloc failure, use old list */
                        return;
                }
                m->next = NULL;
                if(last) last->next = m;
                if(!list) list = m;
                last = m;
        }
        /* success, replace list */
        auth_free_masters(xfr->allow_notify_list);
        xfr->allow_notify_list = list;
}

/** start the lookups for task_transfer */
static void
xfr_transfer_start_lookups(struct auth_xfer* xfr)
{
        /* delete all the looked up addresses in the list */
        xfr->task_transfer->scan_addr = NULL;
        xfr_masterlist_free_addrs(xfr->task_transfer->masters);

        /* start lookup at the first master */
        xfr->task_transfer->lookup_target = xfr->task_transfer->masters;
        xfr->task_transfer->lookup_aaaa = 0;
}

/** move to the next lookup of hostname for task_transfer */
static void
xfr_transfer_move_to_next_lookup(struct auth_xfer* xfr, struct module_env* env)
{
        if(!xfr->task_transfer->lookup_target)
                return; /* already at end of list */
        if(!xfr->task_transfer->lookup_aaaa && env->cfg->do_ip6) {
                /* move to lookup AAAA */
                xfr->task_transfer->lookup_aaaa = 1;
                return;
        }
        xfr->task_transfer->lookup_target = 
                xfr->task_transfer->lookup_target->next;
        xfr->task_transfer->lookup_aaaa = 0;
        if(!env->cfg->do_ip4 && xfr->task_transfer->lookup_target!=NULL)
                xfr->task_transfer->lookup_aaaa = 1;
}

/** start the lookups for task_probe */
static void
xfr_probe_start_lookups(struct auth_xfer* xfr)
{
        /* delete all the looked up addresses in the list */
        xfr->task_probe->scan_addr = NULL;
        xfr_masterlist_free_addrs(xfr->task_probe->masters);

        /* start lookup at the first master */
        xfr->task_probe->lookup_target = xfr->task_probe->masters;
        xfr->task_probe->lookup_aaaa = 0;
}

/** move to the next lookup of hostname for task_probe */
static void
xfr_probe_move_to_next_lookup(struct auth_xfer* xfr, struct module_env* env)
{
        if(!xfr->task_probe->lookup_target)
                return; /* already at end of list */
        if(!xfr->task_probe->lookup_aaaa && env->cfg->do_ip6) {
                /* move to lookup AAAA */
                xfr->task_probe->lookup_aaaa = 1;
                return;
        }
        xfr->task_probe->lookup_target = xfr->task_probe->lookup_target->next;
        xfr->task_probe->lookup_aaaa = 0;
        if(!env->cfg->do_ip4 && xfr->task_probe->lookup_target!=NULL)
                xfr->task_probe->lookup_aaaa = 1;
}

/** start the iteration of the task_transfer list of masters */
static void
xfr_transfer_start_list(struct auth_xfer* xfr, struct auth_master* spec) 
{
        if(spec) {
                xfr->task_transfer->scan_specific = find_master_by_host(
                        xfr->task_transfer->masters, spec->host);
                if(xfr->task_transfer->scan_specific) {
                        xfr->task_transfer->scan_target = NULL;
                        xfr->task_transfer->scan_addr = NULL;
                        if(xfr->task_transfer->scan_specific->list)
                                xfr->task_transfer->scan_addr =
                                        xfr->task_transfer->scan_specific->list;
                        return;
                }
        }
        /* no specific (notified) host to scan */
        xfr->task_transfer->scan_specific = NULL;
        xfr->task_transfer->scan_addr = NULL;
        /* pick up first scan target */
        xfr->task_transfer->scan_target = xfr->task_transfer->masters;
        if(xfr->task_transfer->scan_target && xfr->task_transfer->
                scan_target->list)
                xfr->task_transfer->scan_addr =
                        xfr->task_transfer->scan_target->list;
}

/** start the iteration of the task_probe list of masters */
static void
xfr_probe_start_list(struct auth_xfer* xfr, struct auth_master* spec) 
{
        if(spec) {
                xfr->task_probe->scan_specific = find_master_by_host(
                        xfr->task_probe->masters, spec->host);
                if(xfr->task_probe->scan_specific) {
                        xfr->task_probe->scan_target = NULL;
                        xfr->task_probe->scan_addr = NULL;
                        if(xfr->task_probe->scan_specific->list)
                                xfr->task_probe->scan_addr =
                                        xfr->task_probe->scan_specific->list;
                        return;
                }
        }
        /* no specific (notified) host to scan */
        xfr->task_probe->scan_specific = NULL;
        xfr->task_probe->scan_addr = NULL;
        /* pick up first scan target */
        xfr->task_probe->scan_target = xfr->task_probe->masters;
        if(xfr->task_probe->scan_target && xfr->task_probe->scan_target->list)
                xfr->task_probe->scan_addr =
                        xfr->task_probe->scan_target->list;
}

/** pick up the master that is being scanned right now, task_transfer */
static struct auth_master*
xfr_transfer_current_master(struct auth_xfer* xfr)
{
        if(xfr->task_transfer->scan_specific)
                return xfr->task_transfer->scan_specific;
        return xfr->task_transfer->scan_target;
}

/** pick up the master that is being scanned right now, task_probe */
static struct auth_master*
xfr_probe_current_master(struct auth_xfer* xfr)
{
        if(xfr->task_probe->scan_specific)
                return xfr->task_probe->scan_specific;
        return xfr->task_probe->scan_target;
}

/** true if at end of list, task_transfer */
static int
xfr_transfer_end_of_list(struct auth_xfer* xfr)
{
        return !xfr->task_transfer->scan_specific &&
                !xfr->task_transfer->scan_target;
}

/** true if at end of list, task_probe */
static int
xfr_probe_end_of_list(struct auth_xfer* xfr)
{
        return !xfr->task_probe->scan_specific && !xfr->task_probe->scan_target;
}

/** move to next master in list, task_transfer */
static void
xfr_transfer_nextmaster(struct auth_xfer* xfr)
{
        if(!xfr->task_transfer->scan_specific &&
                !xfr->task_transfer->scan_target)
                return;
        if(xfr->task_transfer->scan_addr) {
                xfr->task_transfer->scan_addr =
                        xfr->task_transfer->scan_addr->next;
                if(xfr->task_transfer->scan_addr)
                        return;
        }
        if(xfr->task_transfer->scan_specific) {
                xfr->task_transfer->scan_specific = NULL;
                xfr->task_transfer->scan_target = xfr->task_transfer->masters;
                if(xfr->task_transfer->scan_target && xfr->task_transfer->
                        scan_target->list)
                        xfr->task_transfer->scan_addr =
                                xfr->task_transfer->scan_target->list;
                return;
        }
        if(!xfr->task_transfer->scan_target)
                return;
        xfr->task_transfer->scan_target = xfr->task_transfer->scan_target->next;
        if(xfr->task_transfer->scan_target && xfr->task_transfer->
                scan_target->list)
                xfr->task_transfer->scan_addr =
                        xfr->task_transfer->scan_target->list;
        return;
}

/** move to next master in list, task_probe */
static void
xfr_probe_nextmaster(struct auth_xfer* xfr)
{
        if(!xfr->task_probe->scan_specific && !xfr->task_probe->scan_target)
                return;
        if(xfr->task_probe->scan_addr) {
                xfr->task_probe->scan_addr = xfr->task_probe->scan_addr->next;
                if(xfr->task_probe->scan_addr)
                        return;
        }
        if(xfr->task_probe->scan_specific) {
                xfr->task_probe->scan_specific = NULL;
                xfr->task_probe->scan_target = xfr->task_probe->masters;
                if(xfr->task_probe->scan_target && xfr->task_probe->
                        scan_target->list)
                        xfr->task_probe->scan_addr =
                                xfr->task_probe->scan_target->list;
                return;
        }
        if(!xfr->task_probe->scan_target)
                return;
        xfr->task_probe->scan_target = xfr->task_probe->scan_target->next;
        if(xfr->task_probe->scan_target && xfr->task_probe->
                scan_target->list)
                xfr->task_probe->scan_addr =
                        xfr->task_probe->scan_target->list;
        return;
}

/** create SOA probe packet for xfr */
static void
xfr_create_soa_probe_packet(struct auth_xfer* xfr, sldns_buffer* buf, 
        uint16_t id)
{
        struct query_info qinfo;

        memset(&qinfo, 0, sizeof(qinfo));
        qinfo.qname = xfr->name;
        qinfo.qname_len = xfr->namelen;
        qinfo.qtype = LDNS_RR_TYPE_SOA;
        qinfo.qclass = xfr->dclass;
        qinfo_query_encode(buf, &qinfo);
        sldns_buffer_write_u16_at(buf, 0, id);
}

/** create IXFR/AXFR packet for xfr */
static void
xfr_create_ixfr_packet(struct auth_xfer* xfr, sldns_buffer* buf, uint16_t id,
        struct auth_master* master)
{
        struct query_info qinfo;
        uint32_t serial;
        int have_zone;
        have_zone = xfr->have_zone;
        serial = xfr->serial;

        memset(&qinfo, 0, sizeof(qinfo));
        qinfo.qname = xfr->name;
        qinfo.qname_len = xfr->namelen;
        xfr->task_transfer->got_xfr_serial = 0;
        xfr->task_transfer->rr_scan_num = 0;
        xfr->task_transfer->incoming_xfr_serial = 0;
        xfr->task_transfer->on_ixfr_is_axfr = 0;
        xfr->task_transfer->on_ixfr = 1;
        qinfo.qtype = LDNS_RR_TYPE_IXFR;
        if(!have_zone || xfr->task_transfer->ixfr_fail || !master->ixfr) {
                qinfo.qtype = LDNS_RR_TYPE_AXFR;
                xfr->task_transfer->ixfr_fail = 0;
                xfr->task_transfer->on_ixfr = 0;
        }

        qinfo.qclass = xfr->dclass;
        qinfo_query_encode(buf, &qinfo);
        sldns_buffer_write_u16_at(buf, 0, id);

        /* append serial for IXFR */
        if(qinfo.qtype == LDNS_RR_TYPE_IXFR) {
                size_t end = sldns_buffer_limit(buf);
                sldns_buffer_clear(buf);
                sldns_buffer_set_position(buf, end);
                /* auth section count 1 */
                sldns_buffer_write_u16_at(buf, LDNS_NSCOUNT_OFF, 1);
                /* write SOA */
                sldns_buffer_write_u8(buf, 0xC0); /* compressed ptr to qname */
                sldns_buffer_write_u8(buf, 0x0C);
                sldns_buffer_write_u16(buf, LDNS_RR_TYPE_SOA);
                sldns_buffer_write_u16(buf, qinfo.qclass);
                sldns_buffer_write_u32(buf, 0); /* ttl */
                sldns_buffer_write_u16(buf, 22); /* rdata length */
                sldns_buffer_write_u8(buf, 0); /* . */
                sldns_buffer_write_u8(buf, 0); /* . */
                sldns_buffer_write_u32(buf, serial); /* serial */
                sldns_buffer_write_u32(buf, 0); /* refresh */
                sldns_buffer_write_u32(buf, 0); /* retry */
                sldns_buffer_write_u32(buf, 0); /* expire */
                sldns_buffer_write_u32(buf, 0); /* minimum */
                sldns_buffer_flip(buf);
        }
}

/** check if returned packet is OK */
static int
check_packet_ok(sldns_buffer* pkt, uint16_t qtype, struct auth_xfer* xfr,
        uint32_t* serial)
{
        /* parse to see if packet worked, valid reply */

        /* check serial number of SOA */
        if(sldns_buffer_limit(pkt) < LDNS_HEADER_SIZE)
                return 0;

        /* check ID */
        if(LDNS_ID_WIRE(sldns_buffer_begin(pkt)) != xfr->task_probe->id)
                return 0;

        /* check flag bits and rcode */
        if(!LDNS_QR_WIRE(sldns_buffer_begin(pkt)))
                return 0;
        if(LDNS_OPCODE_WIRE(sldns_buffer_begin(pkt)) != LDNS_PACKET_QUERY)
                return 0;
        if(LDNS_RCODE_WIRE(sldns_buffer_begin(pkt)) != LDNS_RCODE_NOERROR)
                return 0;

        /* check qname */
        if(LDNS_QDCOUNT(sldns_buffer_begin(pkt)) != 1)
                return 0;
        sldns_buffer_skip(pkt, LDNS_HEADER_SIZE);
        if(sldns_buffer_remaining(pkt) < xfr->namelen)
                return 0;
        if(query_dname_compare(sldns_buffer_current(pkt), xfr->name) != 0)
                return 0;
        sldns_buffer_skip(pkt, (ssize_t)xfr->namelen);

        /* check qtype, qclass */
        if(sldns_buffer_remaining(pkt) < 4)
                return 0;
        if(sldns_buffer_read_u16(pkt) != qtype)
                return 0;
        if(sldns_buffer_read_u16(pkt) != xfr->dclass)
                return 0;

        if(serial) {
                uint16_t rdlen;
                /* read serial number, from answer section SOA */
                if(LDNS_ANCOUNT(sldns_buffer_begin(pkt)) == 0)
                        return 0;
                /* read from first record SOA record */
                if(sldns_buffer_remaining(pkt) < 1)
                        return 0;
                if(dname_pkt_compare(pkt, sldns_buffer_current(pkt),
                        xfr->name) != 0)
                        return 0;
                if(!pkt_dname_len(pkt))
                        return 0;
                /* type, class, ttl, rdatalen */
                if(sldns_buffer_remaining(pkt) < 4+4+2)
                        return 0;
                if(sldns_buffer_read_u16(pkt) != qtype)
                        return 0;
                if(sldns_buffer_read_u16(pkt) != xfr->dclass)
                        return 0;
                sldns_buffer_skip(pkt, 4); /* ttl */
                rdlen = sldns_buffer_read_u16(pkt);
                if(sldns_buffer_remaining(pkt) < rdlen)
                        return 0;
                if(sldns_buffer_remaining(pkt) < 1)
                        return 0;
                if(!pkt_dname_len(pkt)) /* soa name */
                        return 0;
                if(sldns_buffer_remaining(pkt) < 1)
                        return 0;
                if(!pkt_dname_len(pkt)) /* soa name */
                        return 0;
                if(sldns_buffer_remaining(pkt) < 20)
                        return 0;
                *serial = sldns_buffer_read_u32(pkt);
        }
        return 1;
}

/** read one line from chunks into buffer at current position */
static int
chunkline_get_line(struct auth_chunk** chunk, size_t* chunk_pos,
        sldns_buffer* buf)
{
        int readsome = 0;
        while(*chunk) {
                /* more text in this chunk? */
                if(*chunk_pos < (*chunk)->len) {
                        readsome = 1;
                        while(*chunk_pos < (*chunk)->len) {
                                char c = (char)((*chunk)->data[*chunk_pos]);
                                (*chunk_pos)++;
                                if(sldns_buffer_remaining(buf) < 2) {
                                        /* buffer too short */
                                        verbose(VERB_ALGO, "http chunkline, "
                                                "line too long");
                                        return 0;
                                }
                                sldns_buffer_write_u8(buf, (uint8_t)c);
                                if(c == '\n') {
                                        /* we are done */
                                        return 1;
                                }
                        }
                }
                /* move to next chunk */
                *chunk = (*chunk)->next;
                *chunk_pos = 0;
        }
        /* no more text */
        if(readsome) return 1;
        return 0;
}

/** count number of open and closed parenthesis in a chunkline */
static int
chunkline_count_parens(sldns_buffer* buf, size_t start)
{
        size_t end = sldns_buffer_position(buf);
        size_t i;
        int count = 0;
        int squote = 0, dquote = 0;
        for(i=start; i<end; i++) {
                char c = (char)sldns_buffer_read_u8_at(buf, i);
                if(squote && c != '\'') continue;
                if(dquote && c != '"') continue;
                if(c == '"')
                        dquote = !dquote; /* skip quoted part */
                else if(c == '\'')
                        squote = !squote; /* skip quoted part */
                else if(c == '(')
                        count ++;
                else if(c == ')')
                        count --;
                else if(c == ';') {
                        /* rest is a comment */
                        return count;
                }
        }
        return count;
}

/** remove trailing ;... comment from a line in the chunkline buffer */
static void
chunkline_remove_trailcomment(sldns_buffer* buf, size_t start)
{
        size_t end = sldns_buffer_position(buf);
        size_t i;
        int squote = 0, dquote = 0;
        for(i=start; i<end; i++) {
                char c = (char)sldns_buffer_read_u8_at(buf, i);
                if(squote && c != '\'') continue;
                if(dquote && c != '"') continue;
                if(c == '"')
                        dquote = !dquote; /* skip quoted part */
                else if(c == '\'')
                        squote = !squote; /* skip quoted part */
                else if(c == ';') {
                        /* rest is a comment */
                        sldns_buffer_set_position(buf, i);
                        return;
                }
        }
        /* nothing to remove */
}

/** see if a chunkline is a comment line (or empty line) */
static int
chunkline_is_comment_line_or_empty(sldns_buffer* buf)
{
        size_t i, end = sldns_buffer_limit(buf);
        for(i=0; i<end; i++) {
                char c = (char)sldns_buffer_read_u8_at(buf, i);
                if(c == ';')
                        return 1; /* comment */
                else if(c != ' ' && c != '\t' && c != '\r' && c != '\n')
                        return 0; /* not a comment */
        }
        return 1; /* empty */
}

/** find a line with ( ) collated */
static int
chunkline_get_line_collated(struct auth_chunk** chunk, size_t* chunk_pos,
        sldns_buffer* buf)
{
        size_t pos;
        int parens = 0;
        sldns_buffer_clear(buf);
        pos = sldns_buffer_position(buf);
        if(!chunkline_get_line(chunk, chunk_pos, buf)) {
                if(sldns_buffer_position(buf) < sldns_buffer_limit(buf))
                        sldns_buffer_write_u8_at(buf, sldns_buffer_position(buf), 0);
                else sldns_buffer_write_u8_at(buf, sldns_buffer_position(buf)-1, 0);
                sldns_buffer_flip(buf);
                return 0;
        }
        parens += chunkline_count_parens(buf, pos);
        while(parens > 0) {
                chunkline_remove_trailcomment(buf, pos);
                pos = sldns_buffer_position(buf);
                if(!chunkline_get_line(chunk, chunk_pos, buf)) {
                        if(sldns_buffer_position(buf) < sldns_buffer_limit(buf))
                                sldns_buffer_write_u8_at(buf, sldns_buffer_position(buf), 0);
                        else sldns_buffer_write_u8_at(buf, sldns_buffer_position(buf)-1, 0);
                        sldns_buffer_flip(buf);
                        return 0;
                }
                parens += chunkline_count_parens(buf, pos);
        }

        if(sldns_buffer_remaining(buf) < 1) {
                verbose(VERB_ALGO, "http chunkline: "
                        "line too long");
                return 0;
        }
        sldns_buffer_write_u8_at(buf, sldns_buffer_position(buf), 0);
        sldns_buffer_flip(buf);
        return 1;
}

/** process $ORIGIN for http, 0 nothing, 1 done, 2 error */
static int
http_parse_origin(sldns_buffer* buf, struct sldns_file_parse_state* pstate)
{
        char* line = (char*)sldns_buffer_begin(buf);
        if(strncmp(line, "$ORIGIN", 7) == 0 &&
                isspace((unsigned char)line[7])) {
                int s;
                pstate->origin_len = sizeof(pstate->origin);
                s = sldns_str2wire_dname_buf(sldns_strip_ws(line+8),
                        pstate->origin, &pstate->origin_len);
                if(s) {
                        pstate->origin_len = 0;
                        return 2;
                }
                return 1;
        }
        return 0;
}

/** process $TTL for http, 0 nothing, 1 done, 2 error */
static int
http_parse_ttl(sldns_buffer* buf, struct sldns_file_parse_state* pstate)
{
        char* line = (char*)sldns_buffer_begin(buf);
        if(strncmp(line, "$TTL", 4) == 0 &&
                isspace((unsigned char)line[4])) {
                const char* end = NULL;
                int overflow = 0;
                pstate->default_ttl = sldns_str2period(
                        sldns_strip_ws(line+5), &end, &overflow);
                if(overflow) {
                        return 2;
                }
                return 1;
        }
        return 0;
}

/** find noncomment RR line in chunks, collates lines if ( ) format */
static int
chunkline_non_comment_RR(struct auth_chunk** chunk, size_t* chunk_pos,
        sldns_buffer* buf, struct sldns_file_parse_state* pstate)
{
        int ret;
        while(chunkline_get_line_collated(chunk, chunk_pos, buf)) {
                if(chunkline_is_comment_line_or_empty(buf)) {
                        /* a comment, go to next line */
                        continue;
                }
                if((ret=http_parse_origin(buf, pstate))!=0) {
                        if(ret == 2)
                                return 0;
                        continue; /* $ORIGIN has been handled */
                }
                if((ret=http_parse_ttl(buf, pstate))!=0) {
                        if(ret == 2)
                                return 0;
                        continue; /* $TTL has been handled */
                }
                return 1;
        }
        /* no noncomments, fail */
        return 0;
}

/** check syntax of chunklist zonefile, parse first RR, return false on
 * failure and return a string in the scratch buffer (first RR string)
 * on failure. */
static int
http_zonefile_syntax_check(struct auth_xfer* xfr, sldns_buffer* buf)
{
        uint8_t rr[LDNS_RR_BUF_SIZE];
        size_t rr_len, dname_len = 0;
        struct sldns_file_parse_state pstate;
        struct auth_chunk* chunk;
        size_t chunk_pos;
        int e;
        memset(&pstate, 0, sizeof(pstate));
        pstate.default_ttl = 3600;
        if(xfr->namelen < sizeof(pstate.origin)) {
                pstate.origin_len = xfr->namelen;
                memmove(pstate.origin, xfr->name, xfr->namelen);
        }
        chunk = xfr->task_transfer->chunks_first;
        chunk_pos = 0;
        if(!chunkline_non_comment_RR(&chunk, &chunk_pos, buf, &pstate)) {
                return 0;
        }
        rr_len = sizeof(rr);
        e=sldns_str2wire_rr_buf((char*)sldns_buffer_begin(buf), rr, &rr_len,
                &dname_len, pstate.default_ttl,
                pstate.origin_len?pstate.origin:NULL, pstate.origin_len,
                pstate.prev_rr_len?pstate.prev_rr:NULL, pstate.prev_rr_len);
        if(e != 0) {
                log_err("parse failure on first RR[%d]: %s",
                        LDNS_WIREPARSE_OFFSET(e),
                        sldns_get_errorstr_parse(LDNS_WIREPARSE_ERROR(e)));
                return 0;
        }
        /* check that class is correct */
        if(sldns_wirerr_get_class(rr, rr_len, dname_len) != xfr->dclass) {
                log_err("parse failure: first record in downloaded zonefile "
                        "from wrong RR class");
                return 0;
        }
        return 1;
}

/** sum sizes of chunklist */
static size_t
chunklist_sum(struct auth_chunk* list)
{
        struct auth_chunk* p;
        size_t s = 0;
        for(p=list; p; p=p->next) {
                s += p->len;
        }
        return s;
}

/** remove newlines from collated line */
static void
chunkline_newline_removal(sldns_buffer* buf)
{
        size_t i, end=sldns_buffer_limit(buf);
        for(i=0; i<end; i++) {
                char c = (char)sldns_buffer_read_u8_at(buf, i);
                if(c == '\n' && i==end-1) {
                        sldns_buffer_write_u8_at(buf, i, 0);
                        sldns_buffer_set_limit(buf, end-1);
                        return;
                }
                if(c == '\n')
                        sldns_buffer_write_u8_at(buf, i, (uint8_t)' ');
        }
}

/** for http download, parse and add RR to zone */
static int
http_parse_add_rr(struct auth_xfer* xfr, struct auth_zone* z,
        sldns_buffer* buf, struct sldns_file_parse_state* pstate)
{
        uint8_t rr[LDNS_RR_BUF_SIZE];
        size_t rr_len, dname_len = 0;
        int e;
        char* line = (char*)sldns_buffer_begin(buf);
        rr_len = sizeof(rr);
        e = sldns_str2wire_rr_buf(line, rr, &rr_len, &dname_len,
                pstate->default_ttl,
                pstate->origin_len?pstate->origin:NULL, pstate->origin_len,
                pstate->prev_rr_len?pstate->prev_rr:NULL, pstate->prev_rr_len);
        if(e != 0) {
                log_err("%s/%s parse failure RR[%d]: %s in '%s'",
                        xfr->task_transfer->master->host,
                        xfr->task_transfer->master->file,
                        LDNS_WIREPARSE_OFFSET(e),
                        sldns_get_errorstr_parse(LDNS_WIREPARSE_ERROR(e)),
                        line);
                return 0;
        }
        if(rr_len == 0)
                return 1; /* empty line or so */

        /* set prev */
        if(dname_len < sizeof(pstate->prev_rr)) {
                memmove(pstate->prev_rr, rr, dname_len);
                pstate->prev_rr_len = dname_len;
        }

        return az_insert_rr(z, rr, rr_len, dname_len, NULL);
}

/** RR list iterator, returns RRs from answer section one by one from the
 * dns packets in the chunklist */
static void
chunk_rrlist_start(struct auth_xfer* xfr, struct auth_chunk** rr_chunk,
        int* rr_num, size_t* rr_pos)
{
        *rr_chunk = xfr->task_transfer->chunks_first;
        *rr_num = 0;
        *rr_pos = 0;
}

/** RR list iterator, see if we are at the end of the list */
static int
chunk_rrlist_end(struct auth_chunk* rr_chunk, int rr_num)
{
        while(rr_chunk) {
                if(rr_chunk->len < LDNS_HEADER_SIZE)
                        return 1;
                if(rr_num < (int)LDNS_ANCOUNT(rr_chunk->data))
                        return 0;
                /* no more RRs in this chunk */
                /* continue with next chunk, see if it has RRs */
                rr_chunk = rr_chunk->next;
                rr_num = 0;
        }
        return 1;
}

/** RR list iterator, move to next RR */
static void
chunk_rrlist_gonext(struct auth_chunk** rr_chunk, int* rr_num,
        size_t* rr_pos, size_t rr_nextpos)
{
        /* already at end of chunks? */
        if(!*rr_chunk)
                return;
        /* move within this chunk */
        if((*rr_chunk)->len >= LDNS_HEADER_SIZE &&
                (*rr_num)+1 < (int)LDNS_ANCOUNT((*rr_chunk)->data)) {
                (*rr_num) += 1;
                *rr_pos = rr_nextpos;
                return;
        }
        /* no more RRs in this chunk */
        /* continue with next chunk, see if it has RRs */
        if(*rr_chunk)
                *rr_chunk = (*rr_chunk)->next;
        while(*rr_chunk) {
                *rr_num = 0;
                *rr_pos = 0;
                if((*rr_chunk)->len >= LDNS_HEADER_SIZE &&
                        LDNS_ANCOUNT((*rr_chunk)->data) > 0) {
                        return;
                }
                *rr_chunk = (*rr_chunk)->next;
        }
}

/** RR iterator, get current RR information, false on parse error */
static int
chunk_rrlist_get_current(struct auth_chunk* rr_chunk, int rr_num,
        size_t rr_pos, uint8_t** rr_dname, uint16_t* rr_type,
        uint16_t* rr_class, uint32_t* rr_ttl, uint16_t* rr_rdlen,
        uint8_t** rr_rdata, size_t* rr_nextpos)
{
        sldns_buffer pkt;
        /* integrity checks on position */
        if(!rr_chunk) return 0;
        if(rr_chunk->len < LDNS_HEADER_SIZE) return 0;
        if(rr_num >= (int)LDNS_ANCOUNT(rr_chunk->data)) return 0;
        if(rr_pos >= rr_chunk->len) return 0;

        /* fetch rr information */
        sldns_buffer_init_frm_data(&pkt, rr_chunk->data, rr_chunk->len);
        if(rr_pos == 0) {
                size_t i;
                /* skip question section */
                sldns_buffer_set_position(&pkt, LDNS_HEADER_SIZE);
                for(i=0; i<LDNS_QDCOUNT(rr_chunk->data); i++) {
                        if(pkt_dname_len(&pkt) == 0) return 0;
                        if(sldns_buffer_remaining(&pkt) < 4) return 0;
                        sldns_buffer_skip(&pkt, 4); /* type and class */
                }
        } else  {
                sldns_buffer_set_position(&pkt, rr_pos);
        }
        *rr_dname = sldns_buffer_current(&pkt);
        if(pkt_dname_len(&pkt) == 0) return 0;
        if(sldns_buffer_remaining(&pkt) < 10) return 0;
        *rr_type = sldns_buffer_read_u16(&pkt);
        *rr_class = sldns_buffer_read_u16(&pkt);
        *rr_ttl = sldns_buffer_read_u32(&pkt);
        *rr_rdlen = sldns_buffer_read_u16(&pkt);
        if(sldns_buffer_remaining(&pkt) < (*rr_rdlen)) return 0;
        *rr_rdata = sldns_buffer_current(&pkt);
        sldns_buffer_skip(&pkt, (ssize_t)(*rr_rdlen));
        *rr_nextpos = sldns_buffer_position(&pkt);
        return 1;
}

/** print log message where we are in parsing the zone transfer */
static void
log_rrlist_position(const char* label, struct auth_chunk* rr_chunk,
        uint8_t* rr_dname, uint16_t rr_type, size_t rr_counter)
{
        sldns_buffer pkt;
        size_t dlen;
        uint8_t buf[LDNS_MAX_DOMAINLEN];
        char str[LDNS_MAX_DOMAINLEN];
        char typestr[32];
        sldns_buffer_init_frm_data(&pkt, rr_chunk->data, rr_chunk->len);
        sldns_buffer_set_position(&pkt, (size_t)(rr_dname -
                sldns_buffer_begin(&pkt)));
        if((dlen=pkt_dname_len(&pkt)) == 0) return;
        if(dlen >= sizeof(buf)) return;
        dname_pkt_copy(&pkt, buf, rr_dname);
        dname_str(buf, str);
        (void)sldns_wire2str_type_buf(rr_type, typestr, sizeof(typestr));
        verbose(VERB_ALGO, "%s at[%d] %s %s", label, (int)rr_counter,
                str, typestr);
}

/** check that start serial is OK for ixfr. we are at rr_counter == 0,
 * and we are going to check rr_counter == 1 (has to be type SOA) serial */
static int
ixfr_start_serial(struct auth_chunk* rr_chunk, int rr_num, size_t rr_pos,
        uint8_t* rr_dname, uint16_t rr_type, uint16_t rr_class,
        uint32_t rr_ttl, uint16_t rr_rdlen, uint8_t* rr_rdata,
        size_t rr_nextpos, uint32_t transfer_serial, uint32_t xfr_serial)
{
        uint32_t startserial;
        /* move forward on RR */
        chunk_rrlist_gonext(&rr_chunk, &rr_num, &rr_pos, rr_nextpos);
        if(chunk_rrlist_end(rr_chunk, rr_num)) {
                /* no second SOA */
                verbose(VERB_OPS, "IXFR has no second SOA record");
                return 0;
        }
        if(!chunk_rrlist_get_current(rr_chunk, rr_num, rr_pos,
                &rr_dname, &rr_type, &rr_class, &rr_ttl, &rr_rdlen,
                &rr_rdata, &rr_nextpos)) {
                verbose(VERB_OPS, "IXFR cannot parse second SOA record");
                /* failed to parse RR */
                return 0;
        }
        if(rr_type != LDNS_RR_TYPE_SOA) {
                verbose(VERB_OPS, "IXFR second record is not type SOA");
                return 0;
        }
        if(rr_rdlen < 22) {
                verbose(VERB_OPS, "IXFR, second SOA has short rdlength");
                return 0; /* bad SOA rdlen */
        }
        startserial = sldns_read_uint32(rr_rdata+rr_rdlen-20);
        if(startserial == transfer_serial) {
                /* empty AXFR, not an IXFR */
                verbose(VERB_OPS, "IXFR second serial same as first");
                return 0;
        }
        if(startserial != xfr_serial) {
                /* wrong start serial, it does not match the serial in
                 * memory */
                verbose(VERB_OPS, "IXFR is from serial %u to %u but %u "
                        "in memory, rejecting the zone transfer",
                        (unsigned)startserial, (unsigned)transfer_serial,
                        (unsigned)xfr_serial);
                return 0;
        }
        /* everything OK in second SOA serial */
        return 1;
}

/** apply IXFR to zone in memory. z is locked. false on failure(mallocfail) */
static int
apply_ixfr(struct auth_xfer* xfr, struct auth_zone* z,
        struct sldns_buffer* scratch_buffer)
{
        struct auth_chunk* rr_chunk;
        int rr_num;
        size_t rr_pos;
        uint8_t* rr_dname, *rr_rdata;
        uint16_t rr_type, rr_class, rr_rdlen;
        uint32_t rr_ttl;
        size_t rr_nextpos;
        int have_transfer_serial = 0;
        uint32_t transfer_serial = 0;
        size_t rr_counter = 0;
        int delmode = 0;
        int softfail = 0;

        /* start RR iterator over chunklist of packets */
        chunk_rrlist_start(xfr, &rr_chunk, &rr_num, &rr_pos);
        while(!chunk_rrlist_end(rr_chunk, rr_num)) {
                if(!chunk_rrlist_get_current(rr_chunk, rr_num, rr_pos,
                        &rr_dname, &rr_type, &rr_class, &rr_ttl, &rr_rdlen,
                        &rr_rdata, &rr_nextpos)) {
                        /* failed to parse RR */
                        return 0;
                }
                if(verbosity>=7) log_rrlist_position("apply ixfr",
                        rr_chunk, rr_dname, rr_type, rr_counter);
                /* twiddle add/del mode and check for start and end */
                if(rr_counter == 0 && rr_type != LDNS_RR_TYPE_SOA)
                        return 0;
                if(rr_counter == 1 && rr_type != LDNS_RR_TYPE_SOA) {
                        /* this is an AXFR returned from the IXFR master */
                        /* but that should already have been detected, by
                         * on_ixfr_is_axfr */
                        return 0;
                }
                if(rr_type == LDNS_RR_TYPE_SOA) {
                        uint32_t serial;
                        if(rr_rdlen < 22) return 0; /* bad SOA rdlen */
                        serial = sldns_read_uint32(rr_rdata+rr_rdlen-20);
                        if(have_transfer_serial == 0) {
                                have_transfer_serial = 1;
                                transfer_serial = serial;
                                delmode = 1; /* gets negated below */
                                /* check second RR before going any further */
                                if(!ixfr_start_serial(rr_chunk, rr_num, rr_pos,
                                        rr_dname, rr_type, rr_class, rr_ttl,
                                        rr_rdlen, rr_rdata, rr_nextpos,
                                        transfer_serial, xfr->serial)) {
                                        return 0;
                                }
                        } else if(transfer_serial == serial) {
                                have_transfer_serial++;
                                if(rr_counter == 1) {
                                        /* empty AXFR, with SOA; SOA; */
                                        /* should have been detected by
                                         * on_ixfr_is_axfr */
                                        return 0;
                                }
                                if(have_transfer_serial == 3) {
                                        /* see serial three times for end */
                                        /* eg. IXFR:
                                         *  SOA 3 start
                                         *  SOA 1 second RR, followed by del
                                         *  SOA 2 followed by add
                                         *  SOA 2 followed by del
                                         *  SOA 3 followed by add
                                         *  SOA 3 end */
                                        /* ended by SOA record */
                                        xfr->serial = transfer_serial;
                                        break;
                                }
                        }
                        /* twiddle add/del mode */
                        /* switch from delete part to add part and back again
                         * just before the soa, it gets deleted and added too
                         * this means we switch to delete mode for the final
                         * SOA(so skip that one) */
                        delmode = !delmode;
                }
                /* process this RR */
                /* if the RR is deleted twice or added twice, then we 
                 * softfail, and continue with the rest of the IXFR, so
                 * that we serve something fairly nice during the refetch */
                if(verbosity>=7) log_rrlist_position((delmode?"del":"add"),
                        rr_chunk, rr_dname, rr_type, rr_counter);
                if(delmode) {
                        /* delete this RR */
                        int nonexist = 0;
                        if(!az_remove_rr_decompress(z, rr_chunk->data,
                                rr_chunk->len, scratch_buffer, rr_dname,
                                rr_type, rr_class, rr_ttl, rr_rdata, rr_rdlen,
                                &nonexist)) {
                                /* failed, malloc error or so */
                                return 0;
                        }
                        if(nonexist) {
                                /* it was removal of a nonexisting RR */
                                if(verbosity>=4) log_rrlist_position(
                                        "IXFR error nonexistent RR",
                                        rr_chunk, rr_dname, rr_type, rr_counter);
                                softfail = 1;
                        }
                } else if(rr_counter != 0) {
                        /* skip first SOA RR for addition, it is added in
                         * the addition part near the end of the ixfr, when
                         * that serial is seen the second time. */
                        int duplicate = 0;
                        /* add this RR */
                        if(!az_insert_rr_decompress(z, rr_chunk->data,
                                rr_chunk->len, scratch_buffer, rr_dname,
                                rr_type, rr_class, rr_ttl, rr_rdata, rr_rdlen,
                                &duplicate)) {
                                /* failed, malloc error or so */
                                return 0;
                        }
                        if(duplicate) {
                                /* it was a duplicate */
                                if(verbosity>=4) log_rrlist_position(
                                        "IXFR error duplicate RR",
                                        rr_chunk, rr_dname, rr_type, rr_counter);
                                softfail = 1;
                        }
                }

                rr_counter++;
                chunk_rrlist_gonext(&rr_chunk, &rr_num, &rr_pos, rr_nextpos);
        }
        if(softfail) {
                verbose(VERB_ALGO, "IXFR did not apply cleanly, fetching full zone");
                return 0;
        }
        return 1;
}

/** apply AXFR to zone in memory. z is locked. false on failure(mallocfail) */
static int
apply_axfr(struct auth_xfer* xfr, struct auth_zone* z,
        struct sldns_buffer* scratch_buffer)
{
        struct auth_chunk* rr_chunk;
        int rr_num;
        size_t rr_pos;
        uint8_t* rr_dname, *rr_rdata;
        uint16_t rr_type, rr_class, rr_rdlen;
        uint32_t rr_ttl;
        uint32_t serial = 0;
        size_t rr_nextpos;
        size_t rr_counter = 0;
        int have_end_soa = 0;

        /* clear the data tree */
        traverse_postorder(&z->data, auth_data_del, NULL);
        rbtree_init(&z->data, &auth_data_cmp);
        /* clear the RPZ policies */
        if(z->rpz)
                rpz_clear(z->rpz);

        xfr->have_zone = 0;
        xfr->serial = 0;

        /* insert all RRs in to the zone */
        /* insert the SOA only once, skip the last one */
        /* start RR iterator over chunklist of packets */
        chunk_rrlist_start(xfr, &rr_chunk, &rr_num, &rr_pos);
        while(!chunk_rrlist_end(rr_chunk, rr_num)) {
                if(!chunk_rrlist_get_current(rr_chunk, rr_num, rr_pos,
                        &rr_dname, &rr_type, &rr_class, &rr_ttl, &rr_rdlen,
                        &rr_rdata, &rr_nextpos)) {
                        /* failed to parse RR */
                        return 0;
                }
                if(verbosity>=7) log_rrlist_position("apply_axfr",
                        rr_chunk, rr_dname, rr_type, rr_counter);
                if(rr_type == LDNS_RR_TYPE_SOA) {
                        if(rr_counter != 0) {
                                /* end of the axfr */
                                have_end_soa = 1;
                                break;
                        }
                        if(rr_rdlen < 22) return 0; /* bad SOA rdlen */
                        serial = sldns_read_uint32(rr_rdata+rr_rdlen-20);
                }

                /* add this RR */
                if(!az_insert_rr_decompress(z, rr_chunk->data, rr_chunk->len,
                        scratch_buffer, rr_dname, rr_type, rr_class, rr_ttl,
                        rr_rdata, rr_rdlen, NULL)) {
                        /* failed, malloc error or so */
                        return 0;
                }

                rr_counter++;
                chunk_rrlist_gonext(&rr_chunk, &rr_num, &rr_pos, rr_nextpos);
        }
        if(!have_end_soa) {
                log_err("no end SOA record for AXFR");
                return 0;
        }

        xfr->serial = serial;
        xfr->have_zone = 1;
        return 1;
}

/** apply HTTP to zone in memory. z is locked. false on failure(mallocfail) */
static int
apply_http(struct auth_xfer* xfr, struct auth_zone* z,
        struct sldns_buffer* scratch_buffer)
{
        /* parse data in chunks */
        /* parse RR's and read into memory. ignore $INCLUDE from the
         * downloaded file*/
        struct sldns_file_parse_state pstate;
        struct auth_chunk* chunk;
        size_t chunk_pos;
        int ret;
        memset(&pstate, 0, sizeof(pstate));
        pstate.default_ttl = 3600;
        if(xfr->namelen < sizeof(pstate.origin)) {
                pstate.origin_len = xfr->namelen;
                memmove(pstate.origin, xfr->name, xfr->namelen);
        }

        if(verbosity >= VERB_ALGO)
                verbose(VERB_ALGO, "http download %s of size %d",
                xfr->task_transfer->master->file,
                (int)chunklist_sum(xfr->task_transfer->chunks_first));
        if(xfr->task_transfer->chunks_first && verbosity >= VERB_ALGO) {
                char preview[1024];
                if(xfr->task_transfer->chunks_first->len+1 > sizeof(preview)) {
                        memmove(preview, xfr->task_transfer->chunks_first->data,
                                sizeof(preview)-1);
                        preview[sizeof(preview)-1]=0;
                } else {
                        memmove(preview, xfr->task_transfer->chunks_first->data,
                                xfr->task_transfer->chunks_first->len);
                        preview[xfr->task_transfer->chunks_first->len]=0;
                }
                log_info("auth zone http downloaded content preview: %s",
                        preview);
        }

        /* perhaps a little syntax check before we try to apply the data? */
        if(!http_zonefile_syntax_check(xfr, scratch_buffer)) {
                log_err("http download %s/%s does not contain a zonefile, "
                        "but got '%s'", xfr->task_transfer->master->host,
                        xfr->task_transfer->master->file,
                        sldns_buffer_begin(scratch_buffer));
                return 0;
        }

        /* clear the data tree */
        traverse_postorder(&z->data, auth_data_del, NULL);
        rbtree_init(&z->data, &auth_data_cmp);
        /* clear the RPZ policies */
        if(z->rpz)
                rpz_clear(z->rpz);

        xfr->have_zone = 0;
        xfr->serial = 0;

        chunk = xfr->task_transfer->chunks_first;
        chunk_pos = 0;
        pstate.lineno = 0;
        while(chunkline_get_line_collated(&chunk, &chunk_pos, scratch_buffer)) {
                /* process this line */
                pstate.lineno++;
                chunkline_newline_removal(scratch_buffer);
                if(chunkline_is_comment_line_or_empty(scratch_buffer)) {
                        continue;
                }
                /* parse line and add RR */
                if((ret=http_parse_origin(scratch_buffer, &pstate))!=0) {
                        if(ret == 2) {
                                verbose(VERB_ALGO, "error parsing ORIGIN on line [%s:%d] %s",
                                        xfr->task_transfer->master->file,
                                        pstate.lineno,
                                        sldns_buffer_begin(scratch_buffer));
                                return 0;
                        }
                        continue; /* $ORIGIN has been handled */
                }
                if((ret=http_parse_ttl(scratch_buffer, &pstate))!=0) {
                        if(ret == 2) {
                                verbose(VERB_ALGO, "error parsing TTL on line [%s:%d] %s",
                                        xfr->task_transfer->master->file,
                                        pstate.lineno,
                                        sldns_buffer_begin(scratch_buffer));
                                return 0;
                        }
                        continue; /* $TTL has been handled */
                }
                if(!http_parse_add_rr(xfr, z, scratch_buffer, &pstate)) {
                        verbose(VERB_ALGO, "error parsing line [%s:%d] %s",
                                xfr->task_transfer->master->file,
                                pstate.lineno,
                                sldns_buffer_begin(scratch_buffer));
                        return 0;
                }
        }
        return 1;
}

/** write http chunks to zonefile to create downloaded file */
static int
auth_zone_write_chunks(struct auth_xfer* xfr, const char* fname)
{
        FILE* out;
        struct auth_chunk* p;
        out = fopen(fname, "w");
        if(!out) {
                log_err("could not open %s: %s", fname, strerror(errno));
                return 0;
        }
        for(p = xfr->task_transfer->chunks_first; p ; p = p->next) {
                if(!write_out(out, (char*)p->data, p->len)) {
                        log_err("could not write http download to %s", fname);
                        fclose(out);
                        return 0;
                }
        }
        fclose(out);
        return 1;
}

/** write to zonefile after zone has been updated */
static void
xfr_write_after_update(struct auth_xfer* xfr, struct module_env* env)
{
        struct config_file* cfg = env->cfg;
        struct auth_zone* z;
        char tmpfile[1024];
        char* zfilename;
        lock_basic_unlock(&xfr->lock);

        /* get lock again, so it is a readlock and concurrently queries
         * can be answered */
        lock_rw_rdlock(&env->auth_zones->lock);
        z = auth_zone_find(env->auth_zones, xfr->name, xfr->namelen,
                xfr->dclass);
        if(!z) {
                lock_rw_unlock(&env->auth_zones->lock);
                /* the zone is gone, ignore xfr results */
                lock_basic_lock(&xfr->lock);
                return;
        }
        lock_rw_rdlock(&z->lock);
        lock_basic_lock(&xfr->lock);
        lock_rw_unlock(&env->auth_zones->lock);

        if(z->zonefile == NULL || z->zonefile[0] == 0) {
                lock_rw_unlock(&z->lock);
                /* no write needed, no zonefile set */
                return;
        }
        zfilename = z->zonefile;
        if(cfg->chrootdir && cfg->chrootdir[0] && strncmp(zfilename,
                cfg->chrootdir, strlen(cfg->chrootdir)) == 0)
                zfilename += strlen(cfg->chrootdir);
        if(verbosity >= VERB_ALGO) {
                char nm[LDNS_MAX_DOMAINLEN];
                dname_str(z->name, nm);
                verbose(VERB_ALGO, "write zonefile %s for %s", zfilename, nm);
        }

        /* write to tempfile first */
        if((size_t)strlen(zfilename) + 16 > sizeof(tmpfile)) {
                verbose(VERB_ALGO, "tmpfilename too long, cannot update "
                        " zonefile %s", zfilename);
                lock_rw_unlock(&z->lock);
                return;
        }
        snprintf(tmpfile, sizeof(tmpfile), "%s.tmp%u", zfilename,
                (unsigned)getpid());
        if(xfr->task_transfer->master->http) {
                /* use the stored chunk list to write them */
                if(!auth_zone_write_chunks(xfr, tmpfile)) {
                        unlink(tmpfile);
                        lock_rw_unlock(&z->lock);
                        return;
                }
        } else if(!auth_zone_write_file(z, tmpfile)) {
                unlink(tmpfile);
                lock_rw_unlock(&z->lock);
                return;
        }
#ifdef UB_ON_WINDOWS
        (void)unlink(zfilename); /* windows does not replace file with rename() */
#endif
        if(rename(tmpfile, zfilename) < 0) {
                log_err("could not rename(%s, %s): %s", tmpfile, zfilename,
                        strerror(errno));
                unlink(tmpfile);
                lock_rw_unlock(&z->lock);
                return;
        }
        lock_rw_unlock(&z->lock);
}

/** reacquire locks and structures. Starts with no locks, ends
 * with xfr and z locks, if fail, no z lock */
static int xfr_process_reacquire_locks(struct auth_xfer* xfr,
        struct module_env* env, struct auth_zone** z)
{
        /* release xfr lock, then, while holding az->lock grab both
         * z->lock and xfr->lock */
        lock_rw_rdlock(&env->auth_zones->lock);
        *z = auth_zone_find(env->auth_zones, xfr->name, xfr->namelen,
                xfr->dclass);
        if(!*z) {
                lock_rw_unlock(&env->auth_zones->lock);
                lock_basic_lock(&xfr->lock);
                *z = NULL;
                return 0;
        }
        lock_rw_wrlock(&(*z)->lock);
        lock_basic_lock(&xfr->lock);
        lock_rw_unlock(&env->auth_zones->lock);
        return 1;
}

/** process chunk list and update zone in memory,
 * return false if it did not work */
static int
xfr_process_chunk_list(struct auth_xfer* xfr, struct module_env* env,
        int* ixfr_fail)
{
        struct auth_zone* z;

        /* obtain locks and structures */
        lock_basic_unlock(&xfr->lock);
        if(!xfr_process_reacquire_locks(xfr, env, &z)) {
                /* the zone is gone, ignore xfr results */
                return 0;
        }
        /* holding xfr and z locks */

        /* apply data */
        if(xfr->task_transfer->master->http) {
                if(!apply_http(xfr, z, env->scratch_buffer)) {
                        lock_rw_unlock(&z->lock);
                        verbose(VERB_ALGO, "http from %s: could not store data",
                                xfr->task_transfer->master->host);
                        return 0;
                }
        } else if(xfr->task_transfer->on_ixfr &&
                !xfr->task_transfer->on_ixfr_is_axfr) {
                if(!apply_ixfr(xfr, z, env->scratch_buffer)) {
                        lock_rw_unlock(&z->lock);
                        verbose(VERB_ALGO, "xfr from %s: could not store IXFR"
                                " data", xfr->task_transfer->master->host);
                        *ixfr_fail = 1;
                        return 0;
                }
        } else {
                if(!apply_axfr(xfr, z, env->scratch_buffer)) {
                        lock_rw_unlock(&z->lock);
                        verbose(VERB_ALGO, "xfr from %s: could not store AXFR"
                                " data", xfr->task_transfer->master->host);
                        return 0;
                }
        }
        xfr->zone_expired = 0;
        z->zone_expired = 0;
        if(!xfr_find_soa(z, xfr)) {
                lock_rw_unlock(&z->lock);
                verbose(VERB_ALGO, "xfr from %s: no SOA in zone after update"
                        " (or malformed RR)", xfr->task_transfer->master->host);
                return 0;
        }

        /* release xfr lock while verifying zonemd because it may have
         * to spawn lookups in the state machines */
        lock_basic_unlock(&xfr->lock);
        /* holding z lock */
        auth_zone_verify_zonemd(z, env, &env->mesh->mods, NULL, 0, 0);
        if(z->zone_expired) {
                char zname[LDNS_MAX_DOMAINLEN];
                /* ZONEMD must have failed */
                /* reacquire locks, so we hold xfr lock on exit of routine,
                 * and both xfr and z again after releasing xfr for potential
                 * state machine mesh callbacks */
                lock_rw_unlock(&z->lock);
                if(!xfr_process_reacquire_locks(xfr, env, &z))
                        return 0;
                dname_str(xfr->name, zname);
                verbose(VERB_ALGO, "xfr from %s: ZONEMD failed for %s, transfer is failed", xfr->task_transfer->master->host, zname);
                xfr->zone_expired = 1;
                lock_rw_unlock(&z->lock);
                return 0;
        }
        /* reacquire locks, so we hold xfr lock on exit of routine,
         * and both xfr and z again after releasing xfr for potential
         * state machine mesh callbacks */
        lock_rw_unlock(&z->lock);
        if(!xfr_process_reacquire_locks(xfr, env, &z))
                return 0;
        /* holding xfr and z locks */

        if(xfr->have_zone)
                xfr->lease_time = *env->now;

        if(z->rpz)
                rpz_finish_config(z->rpz);

        /* unlock */
        lock_rw_unlock(&z->lock);

        if(verbosity >= VERB_QUERY && xfr->have_zone) {
                char zname[LDNS_MAX_DOMAINLEN];
                dname_str(xfr->name, zname);
                verbose(VERB_QUERY, "auth zone %s updated to serial %u", zname,
                        (unsigned)xfr->serial);
        }
        /* see if we need to write to a zonefile */
        xfr_write_after_update(xfr, env);
        return 1;
}

/** disown task_transfer.  caller must hold xfr.lock */
static void
xfr_transfer_disown(struct auth_xfer* xfr)
{
        /* remove timer (from this worker's event base) */
        comm_timer_delete(xfr->task_transfer->timer);
        xfr->task_transfer->timer = NULL;
        /* remove the commpoint */
        comm_point_delete(xfr->task_transfer->cp);
        xfr->task_transfer->cp = NULL;
        /* we don't own this item anymore */
        xfr->task_transfer->worker = NULL;
        xfr->task_transfer->env = NULL;
}

/** lookup a host name for its addresses, if needed */
static int
xfr_transfer_lookup_host(struct auth_xfer* xfr, struct module_env* env)
{
        struct sockaddr_storage addr;
        socklen_t addrlen = 0;
        struct auth_master* master = xfr->task_transfer->lookup_target;
        struct query_info qinfo;
        uint16_t qflags = BIT_RD;
        uint8_t dname[LDNS_MAX_DOMAINLEN+1];
        struct edns_data edns;
        sldns_buffer* buf = env->scratch_buffer;
        if(!master) return 0;
        if(extstrtoaddr(master->host, &addr, &addrlen, UNBOUND_DNS_PORT)) {
                /* not needed, host is in IP addr format */
                return 0;
        }
        if(master->allow_notify)
                return 0; /* allow-notifies are not transferred from, no
                lookup is needed */

        /* use mesh_new_callback to probe for non-addr hosts,
         * and then wait for them to be looked up (in cache, or query) */
        qinfo.qname_len = sizeof(dname);
        if(sldns_str2wire_dname_buf(master->host, dname, &qinfo.qname_len)
                != 0) {
                log_err("cannot parse host name of master %s", master->host);
                return 0;
        }
        qinfo.qname = dname;
        qinfo.qclass = xfr->dclass;
        qinfo.qtype = LDNS_RR_TYPE_A;
        if(xfr->task_transfer->lookup_aaaa)
                qinfo.qtype = LDNS_RR_TYPE_AAAA;
        qinfo.local_alias = NULL;
        if(verbosity >= VERB_ALGO) {
                char buf1[512];
                char buf2[LDNS_MAX_DOMAINLEN];
                dname_str(xfr->name, buf2);
                snprintf(buf1, sizeof(buf1), "auth zone %s: master lookup"
                        " for task_transfer", buf2);
                log_query_info(VERB_ALGO, buf1, &qinfo);
        }
        edns.edns_present = 1;
        edns.ext_rcode = 0;
        edns.edns_version = 0;
        edns.bits = EDNS_DO;
        edns.opt_list_in = NULL;
        edns.opt_list_out = NULL;
        edns.opt_list_inplace_cb_out = NULL;
        edns.padding_block_size = 0;
        edns.cookie_present = 0;
        edns.cookie_valid = 0;
        if(sldns_buffer_capacity(buf) < 65535)
                edns.udp_size = (uint16_t)sldns_buffer_capacity(buf);
        else    edns.udp_size = 65535;

        /* unlock xfr during mesh_new_callback() because the callback can be
         * called straight away */
        lock_basic_unlock(&xfr->lock);
        if(!mesh_new_callback(env->mesh, &qinfo, qflags, &edns, buf, 0,
                &auth_xfer_transfer_lookup_callback, xfr, 0)) {
                lock_basic_lock(&xfr->lock);
                log_err("out of memory lookup up master %s", master->host);
                return 0;
        }
        lock_basic_lock(&xfr->lock);
        return 1;
}

/** initiate TCP to the target and fetch zone.
 * returns true if that was successfully started, and timeout setup. */
static int
xfr_transfer_init_fetch(struct auth_xfer* xfr, struct module_env* env)
{
        struct sockaddr_storage addr;
        socklen_t addrlen = 0;
        struct auth_master* master = xfr->task_transfer->master;
        char *auth_name = NULL;
        struct timeval t;
        int timeout;
        if(!master) return 0;
        if(master->allow_notify) return 0; /* only for notify */

        /* get master addr */
        if(xfr->task_transfer->scan_addr) {
                addrlen = xfr->task_transfer->scan_addr->addrlen;
                memmove(&addr, &xfr->task_transfer->scan_addr->addr, addrlen);
        } else {
                if(!authextstrtoaddr(master->host, &addr, &addrlen, &auth_name)) {
                        /* the ones that are not in addr format are supposed
                         * to be looked up.  The lookup has failed however,
                         * so skip them */
                        char zname[LDNS_MAX_DOMAINLEN];
                        dname_str(xfr->name, zname);
                        log_err("%s: failed lookup, cannot transfer from master %s",
                                zname, master->host);
                        return 0;
                }
        }

        /* remove previous TCP connection (if any) */
        if(xfr->task_transfer->cp) {
                comm_point_delete(xfr->task_transfer->cp);
                xfr->task_transfer->cp = NULL;
        }
        if(!xfr->task_transfer->timer) {
                xfr->task_transfer->timer = comm_timer_create(env->worker_base,
                        auth_xfer_transfer_timer_callback, xfr);
                if(!xfr->task_transfer->timer) {
                        log_err("malloc failure");
                        return 0;
                }
        }
        timeout = AUTH_TRANSFER_TIMEOUT;
#ifndef S_SPLINT_S
        t.tv_sec = timeout/1000;
        t.tv_usec = (timeout%1000)*1000;
#endif

        if(master->http) {
                /* perform http fetch */
                /* store http port number into sockaddr,
                 * unless someone used unbound's host@port notation */
                xfr->task_transfer->on_ixfr = 0;
                if(strchr(master->host, '@') == NULL)
                        sockaddr_store_port(&addr, addrlen, master->port);
                xfr->task_transfer->cp = outnet_comm_point_for_http(
                        env->outnet, auth_xfer_transfer_http_callback, xfr,
                        &addr, addrlen, -1, master->ssl, master->host,
                        master->file, env->cfg);
                if(!xfr->task_transfer->cp) {
                        char zname[LDNS_MAX_DOMAINLEN], as[256];
                        dname_str(xfr->name, zname);
                        addr_port_to_str(&addr, addrlen, as, sizeof(as));
                        verbose(VERB_ALGO, "cannot create http cp "
                                "connection for %s to %s", zname, as);
                        return 0;
                }
                comm_timer_set(xfr->task_transfer->timer, &t);
                if(verbosity >= VERB_ALGO) {
                        char zname[LDNS_MAX_DOMAINLEN], as[256];
                        dname_str(xfr->name, zname);
                        addr_port_to_str(&addr, addrlen, as, sizeof(as));
                        verbose(VERB_ALGO, "auth zone %s transfer next HTTP fetch from %s started", zname, as);
                }
                /* Create or refresh the list of allow_notify addrs */
                probe_copy_masters_for_allow_notify(xfr);
                return 1;
        }

        /* perform AXFR/IXFR */
        /* set the packet to be written */
        /* create new ID */
        xfr->task_transfer->id = GET_RANDOM_ID(env->rnd);
        xfr_create_ixfr_packet(xfr, env->scratch_buffer,
                xfr->task_transfer->id, master);

        /* connect on fd */
        xfr->task_transfer->cp = outnet_comm_point_for_tcp(env->outnet,
                auth_xfer_transfer_tcp_callback, xfr, &addr, addrlen,
                env->scratch_buffer, -1,
                auth_name != NULL, auth_name);
        if(!xfr->task_transfer->cp) {
                char zname[LDNS_MAX_DOMAINLEN], as[256];
                dname_str(xfr->name, zname);
                addr_port_to_str(&addr, addrlen, as, sizeof(as));
                verbose(VERB_ALGO, "cannot create tcp cp connection for "
                        "xfr %s to %s", zname, as);
                return 0;
        }
        comm_timer_set(xfr->task_transfer->timer, &t);
        if(verbosity >= VERB_ALGO) {
                char zname[LDNS_MAX_DOMAINLEN], as[256];
                dname_str(xfr->name, zname);
                addr_port_to_str(&addr, addrlen, as, sizeof(as));
                verbose(VERB_ALGO, "auth zone %s transfer next %s fetch from %s started", zname, 
                        (xfr->task_transfer->on_ixfr?"IXFR":"AXFR"), as);
        }
        return 1;
}

/** perform next lookup, next transfer TCP, or end and resume wait time task */
static void
xfr_transfer_nexttarget_or_end(struct auth_xfer* xfr, struct module_env* env)
{
        log_assert(xfr->task_transfer->worker == env->worker);

        /* are we performing lookups? */
        while(xfr->task_transfer->lookup_target) {
                if(xfr_transfer_lookup_host(xfr, env)) {
                        /* wait for lookup to finish,
                         * note that the hostname may be in unbound's cache
                         * and we may then get an instant cache response,
                         * and that calls the callback just like a full
                         * lookup and lookup failures also call callback */
                        if(verbosity >= VERB_ALGO) {
                                char zname[LDNS_MAX_DOMAINLEN];
                                dname_str(xfr->name, zname);
                                verbose(VERB_ALGO, "auth zone %s transfer next target lookup", zname);
                        }
                        lock_basic_unlock(&xfr->lock);
                        return;
                }
                xfr_transfer_move_to_next_lookup(xfr, env);
        }

        /* initiate TCP and fetch the zone from the master */
        /* and set timeout on it */
        while(!xfr_transfer_end_of_list(xfr)) {
                xfr->task_transfer->master = xfr_transfer_current_master(xfr);
                if(xfr_transfer_init_fetch(xfr, env)) {
                        /* successfully started, wait for callback */
                        lock_basic_unlock(&xfr->lock);
                        return;
                }
                /* failed to fetch, next master */
                xfr_transfer_nextmaster(xfr);
        }
        if(verbosity >= VERB_ALGO) {
                char zname[LDNS_MAX_DOMAINLEN];
                dname_str(xfr->name, zname);
                verbose(VERB_ALGO, "auth zone %s transfer failed, wait", zname);
        }

        /* we failed to fetch the zone, move to wait task
         * use the shorter retry timeout */
        xfr_transfer_disown(xfr);

        /* pick up the nextprobe task and wait */
        if(xfr->task_nextprobe->worker == NULL)
                xfr_set_timeout(xfr, env, 1, 0);
        lock_basic_unlock(&xfr->lock);
}

/** add addrs from A or AAAA rrset to the master */
static void
xfr_master_add_addrs(struct auth_master* m, struct ub_packed_rrset_key* rrset,
        uint16_t rrtype)
{
        size_t i;
        struct packed_rrset_data* data;
        if(!m || !rrset) return;
        if(rrtype != LDNS_RR_TYPE_A && rrtype != LDNS_RR_TYPE_AAAA)
                return;
        data = (struct packed_rrset_data*)rrset->entry.data;
        for(i=0; i<data->count; i++) {
                struct auth_addr* a;
                size_t len = data->rr_len[i] - 2;
                uint8_t* rdata = data->rr_data[i]+2;
                if(rrtype == LDNS_RR_TYPE_A && len != INET_SIZE)
                        continue; /* wrong length for A */
                if(rrtype == LDNS_RR_TYPE_AAAA && len != INET6_SIZE)
                        continue; /* wrong length for AAAA */
                
                /* add and alloc it */
                a = (struct auth_addr*)calloc(1, sizeof(*a));
                if(!a) {
                        log_err("out of memory");
                        return;
                }
                if(rrtype == LDNS_RR_TYPE_A) {
                        struct sockaddr_in* sa;
                        a->addrlen = (socklen_t)sizeof(*sa);
                        sa = (struct sockaddr_in*)&a->addr;
                        sa->sin_family = AF_INET;
                        sa->sin_port = (in_port_t)htons(UNBOUND_DNS_PORT);
                        memmove(&sa->sin_addr, rdata, INET_SIZE);
                } else {
                        struct sockaddr_in6* sa;
                        a->addrlen = (socklen_t)sizeof(*sa);
                        sa = (struct sockaddr_in6*)&a->addr;
                        sa->sin6_family = AF_INET6;
                        sa->sin6_port = (in_port_t)htons(UNBOUND_DNS_PORT);
                        memmove(&sa->sin6_addr, rdata, INET6_SIZE);
                }
                if(verbosity >= VERB_ALGO) {
                        char s[64];
                        addr_port_to_str(&a->addr, a->addrlen, s, sizeof(s));
                        verbose(VERB_ALGO, "auth host %s lookup %s",
                                m->host, s);
                }
                /* append to list */
                a->next = m->list;
                m->list = a;
        }
}

/** callback for task_transfer lookup of host name, of A or AAAA */
void auth_xfer_transfer_lookup_callback(void* arg, int rcode, sldns_buffer* buf,
        enum sec_status ATTR_UNUSED(sec), char* ATTR_UNUSED(why_bogus),
        int ATTR_UNUSED(was_ratelimited))
{
        struct auth_xfer* xfr = (struct auth_xfer*)arg;
        struct module_env* env;
        log_assert(xfr->task_transfer);
        lock_basic_lock(&xfr->lock);
        env = xfr->task_transfer->env;
        if(!env || env->outnet->want_to_quit) {
                lock_basic_unlock(&xfr->lock);
                return; /* stop on quit */
        }

        /* process result */
        if(rcode == LDNS_RCODE_NOERROR) {
                uint16_t wanted_qtype = LDNS_RR_TYPE_A;
                struct regional* temp = env->scratch;
                struct query_info rq;
                struct reply_info* rep;
                if(xfr->task_transfer->lookup_aaaa)
                        wanted_qtype = LDNS_RR_TYPE_AAAA;
                memset(&rq, 0, sizeof(rq));
                rep = parse_reply_in_temp_region(buf, temp, &rq);
                if(rep && rq.qtype == wanted_qtype &&
                        FLAGS_GET_RCODE(rep->flags) == LDNS_RCODE_NOERROR) {
                        /* parsed successfully */
                        struct ub_packed_rrset_key* answer =
                                reply_find_answer_rrset(&rq, rep);
                        if(answer) {
                                xfr_master_add_addrs(xfr->task_transfer->
                                        lookup_target, answer, wanted_qtype);
                        } else {
                                if(verbosity >= VERB_ALGO) {
                                        char zname[LDNS_MAX_DOMAINLEN];
                                        dname_str(xfr->name, zname);
                                        verbose(VERB_ALGO, "auth zone %s host %s type %s transfer lookup has nodata", zname, xfr->task_transfer->lookup_target->host, (xfr->task_transfer->lookup_aaaa?"AAAA":"A"));
                                }
                        }
                } else {
                        if(verbosity >= VERB_ALGO) {
                                char zname[LDNS_MAX_DOMAINLEN];
                                dname_str(xfr->name, zname);
                                verbose(VERB_ALGO, "auth zone %s host %s type %s transfer lookup has no answer", zname, xfr->task_transfer->lookup_target->host, (xfr->task_transfer->lookup_aaaa?"AAAA":"A"));
                        }
                }
                regional_free_all(temp);
        } else {
                if(verbosity >= VERB_ALGO) {
                        char zname[LDNS_MAX_DOMAINLEN];
                        dname_str(xfr->name, zname);
                        verbose(VERB_ALGO, "auth zone %s host %s type %s transfer lookup failed", zname, xfr->task_transfer->lookup_target->host, (xfr->task_transfer->lookup_aaaa?"AAAA":"A"));
                }
        }
        if(xfr->task_transfer->lookup_target->list &&
                xfr->task_transfer->lookup_target == xfr_transfer_current_master(xfr))
                xfr->task_transfer->scan_addr = xfr->task_transfer->lookup_target->list;

        /* move to lookup AAAA after A lookup, move to next hostname lookup,
         * or move to fetch the zone, or, if nothing to do, end task_transfer */
        xfr_transfer_move_to_next_lookup(xfr, env);
        xfr_transfer_nexttarget_or_end(xfr, env);
}

/** check if xfer (AXFR or IXFR) packet is OK.
 * return false if we lost connection (SERVFAIL, or unreadable).
 * return false if we need to move from IXFR to AXFR, with gonextonfail
 *      set to false, so the same master is tried again, but with AXFR.
 * return true if fine to link into data.
 * return true with transferdone=true when the transfer has ended.
 */
static int
check_xfer_packet(sldns_buffer* pkt, struct auth_xfer* xfr,
        int* gonextonfail, int* transferdone)
{
        uint8_t* wire = sldns_buffer_begin(pkt);
        int i;
        if(sldns_buffer_limit(pkt) < LDNS_HEADER_SIZE) {
                verbose(VERB_ALGO, "xfr to %s failed, packet too small",
                        xfr->task_transfer->master->host);
                return 0;
        }
        if(!LDNS_QR_WIRE(wire)) {
                verbose(VERB_ALGO, "xfr to %s failed, packet has no QR flag",
                        xfr->task_transfer->master->host);
                return 0;
        }
        if(LDNS_TC_WIRE(wire)) {
                verbose(VERB_ALGO, "xfr to %s failed, packet has TC flag",
                        xfr->task_transfer->master->host);
                return 0;
        }
        /* check ID */
        if(LDNS_ID_WIRE(wire) != xfr->task_transfer->id) {
                verbose(VERB_ALGO, "xfr to %s failed, packet wrong ID",
                        xfr->task_transfer->master->host);
                return 0;
        }
        if(LDNS_RCODE_WIRE(wire) != LDNS_RCODE_NOERROR) {
                char rcode[32];
                sldns_wire2str_rcode_buf((int)LDNS_RCODE_WIRE(wire), rcode,
                        sizeof(rcode));
                /* if we are doing IXFR, check for fallback */
                if(xfr->task_transfer->on_ixfr) {
                        if(LDNS_RCODE_WIRE(wire) == LDNS_RCODE_NOTIMPL ||
                                LDNS_RCODE_WIRE(wire) == LDNS_RCODE_SERVFAIL ||
                                LDNS_RCODE_WIRE(wire) == LDNS_RCODE_REFUSED ||
                                LDNS_RCODE_WIRE(wire) == LDNS_RCODE_FORMERR) {
                                verbose(VERB_ALGO, "xfr to %s, fallback "
                                        "from IXFR to AXFR (with rcode %s)",
                                        xfr->task_transfer->master->host,
                                        rcode);
                                xfr->task_transfer->ixfr_fail = 1;
                                *gonextonfail = 0;
                                return 0;
                        }
                }
                verbose(VERB_ALGO, "xfr to %s failed, packet with rcode %s",
                        xfr->task_transfer->master->host, rcode);
                return 0;
        }
        if(LDNS_OPCODE_WIRE(wire) != LDNS_PACKET_QUERY) {
                verbose(VERB_ALGO, "xfr to %s failed, packet with bad opcode",
                        xfr->task_transfer->master->host);
                return 0;
        }
        if(LDNS_QDCOUNT(wire) > 1) {
                verbose(VERB_ALGO, "xfr to %s failed, packet has qdcount %d",
                        xfr->task_transfer->master->host,
                        (int)LDNS_QDCOUNT(wire));
                return 0;
        }

        /* check qname */
        sldns_buffer_set_position(pkt, LDNS_HEADER_SIZE);
        for(i=0; i<(int)LDNS_QDCOUNT(wire); i++) {
                size_t pos = sldns_buffer_position(pkt);
                uint16_t qtype, qclass;
                if(pkt_dname_len(pkt) == 0) {
                        verbose(VERB_ALGO, "xfr to %s failed, packet with "
                                "malformed dname",
                                xfr->task_transfer->master->host);
                        return 0;
                }
                if(dname_pkt_compare(pkt, sldns_buffer_at(pkt, pos),
                        xfr->name) != 0) {
                        verbose(VERB_ALGO, "xfr to %s failed, packet with "
                                "wrong qname",
                                xfr->task_transfer->master->host);
                        return 0;
                }
                if(sldns_buffer_remaining(pkt) < 4) {
                        verbose(VERB_ALGO, "xfr to %s failed, packet with "
                                "truncated query RR",
                                xfr->task_transfer->master->host);
                        return 0;
                }
                qtype = sldns_buffer_read_u16(pkt);
                qclass = sldns_buffer_read_u16(pkt);
                if(qclass != xfr->dclass) {
                        verbose(VERB_ALGO, "xfr to %s failed, packet with "
                                "wrong qclass",
                                xfr->task_transfer->master->host);
                        return 0;
                }
                if(xfr->task_transfer->on_ixfr) {
                        if(qtype != LDNS_RR_TYPE_IXFR) {
                                verbose(VERB_ALGO, "xfr to %s failed, packet "
                                        "with wrong qtype, expected IXFR",
                                xfr->task_transfer->master->host);
                                return 0;
                        }
                } else {
                        if(qtype != LDNS_RR_TYPE_AXFR) {
                                verbose(VERB_ALGO, "xfr to %s failed, packet "
                                        "with wrong qtype, expected AXFR",
                                xfr->task_transfer->master->host);
                                return 0;
                        }
                }
        }

        /* check parse of RRs in packet, store first SOA serial
         * to be able to detect last SOA (with that serial) to see if done */
        /* also check for IXFR 'zone up to date' reply */
        for(i=0; i<(int)LDNS_ANCOUNT(wire); i++) {
                size_t pos = sldns_buffer_position(pkt);
                uint16_t tp, rdlen;
                if(pkt_dname_len(pkt) == 0) {
                        verbose(VERB_ALGO, "xfr to %s failed, packet with "
                                "malformed dname in answer section",
                                xfr->task_transfer->master->host);
                        return 0;
                }
                if(sldns_buffer_remaining(pkt) < 10) {
                        verbose(VERB_ALGO, "xfr to %s failed, packet with "
                                "truncated RR",
                                xfr->task_transfer->master->host);
                        return 0;
                }
                tp = sldns_buffer_read_u16(pkt);
                (void)sldns_buffer_read_u16(pkt); /* class */
                (void)sldns_buffer_read_u32(pkt); /* ttl */
                rdlen = sldns_buffer_read_u16(pkt);
                if(sldns_buffer_remaining(pkt) < rdlen) {
                        verbose(VERB_ALGO, "xfr to %s failed, packet with "
                                "truncated RR rdata",
                                xfr->task_transfer->master->host);
                        return 0;
                }

                /* RR parses (haven't checked rdata itself), now look at
                 * SOA records to see serial number */
                if(xfr->task_transfer->rr_scan_num == 0 &&
                        tp != LDNS_RR_TYPE_SOA) {
                        verbose(VERB_ALGO, "xfr to %s failed, packet with "
                                "malformed zone transfer, no start SOA",
                                xfr->task_transfer->master->host);
                        return 0;
                }
                if(xfr->task_transfer->rr_scan_num == 1 &&
                        tp != LDNS_RR_TYPE_SOA) {
                        /* second RR is not a SOA record, this is not an IXFR
                         * the master is replying with an AXFR */
                        xfr->task_transfer->on_ixfr_is_axfr = 1;
                }
                if(tp == LDNS_RR_TYPE_SOA) {
                        uint32_t serial;
                        if(rdlen < 22) {
                                verbose(VERB_ALGO, "xfr to %s failed, packet "
                                        "with SOA with malformed rdata",
                                        xfr->task_transfer->master->host);
                                return 0;
                        }
                        if(dname_pkt_compare(pkt, sldns_buffer_at(pkt, pos),
                                xfr->name) != 0) {
                                verbose(VERB_ALGO, "xfr to %s failed, packet "
                                        "with SOA with wrong dname",
                                        xfr->task_transfer->master->host);
                                return 0;
                        }

                        /* read serial number of SOA */
                        serial = sldns_buffer_read_u32_at(pkt,
                                sldns_buffer_position(pkt)+rdlen-20);

                        /* check for IXFR 'zone has SOA x' reply */
                        if(xfr->task_transfer->on_ixfr &&
                                xfr->task_transfer->rr_scan_num == 0 &&
                                LDNS_ANCOUNT(wire)==1) {
                                verbose(VERB_ALGO, "xfr to %s ended, "
                                        "IXFR reply that zone has serial %u,"
                                        " fallback from IXFR to AXFR",
                                        xfr->task_transfer->master->host,
                                        (unsigned)serial);
                                xfr->task_transfer->ixfr_fail = 1;
                                *gonextonfail = 0;
                                return 0;
                        }

                        /* if first SOA, store serial number */
                        if(xfr->task_transfer->got_xfr_serial == 0) {
                                xfr->task_transfer->got_xfr_serial = 1;
                                xfr->task_transfer->incoming_xfr_serial =
                                        serial;
                                verbose(VERB_ALGO, "xfr %s: contains "
                                        "SOA serial %u",
                                        xfr->task_transfer->master->host,
                                        (unsigned)serial);
                        /* see if end of AXFR */
                        } else if(!xfr->task_transfer->on_ixfr ||
                                xfr->task_transfer->on_ixfr_is_axfr) {
                                /* second SOA with serial is the end
                                 * for AXFR */
                                *transferdone = 1;
                                verbose(VERB_ALGO, "xfr %s: last AXFR packet",
                                        xfr->task_transfer->master->host);
                        /* for IXFR, count SOA records with that serial */
                        } else if(xfr->task_transfer->incoming_xfr_serial ==
                                serial && xfr->task_transfer->got_xfr_serial
                                == 1) {
                                xfr->task_transfer->got_xfr_serial++;
                        /* if not first soa, if serial==firstserial, the
                         * third time we are at the end, for IXFR */
                        } else if(xfr->task_transfer->incoming_xfr_serial ==
                                serial && xfr->task_transfer->got_xfr_serial
                                == 2) {
                                verbose(VERB_ALGO, "xfr %s: last IXFR packet",
                                        xfr->task_transfer->master->host);
                                *transferdone = 1;
                                /* continue parse check, if that succeeds,
                                 * transfer is done */
                        }
                }
                xfr->task_transfer->rr_scan_num++;

                /* skip over RR rdata to go to the next RR */
                sldns_buffer_skip(pkt, (ssize_t)rdlen);
        }

        /* check authority section */
        /* we skip over the RRs checking packet format */
        for(i=0; i<(int)LDNS_NSCOUNT(wire); i++) {
                uint16_t rdlen;
                if(pkt_dname_len(pkt) == 0) {
                        verbose(VERB_ALGO, "xfr to %s failed, packet with "
                                "malformed dname in authority section",
                                xfr->task_transfer->master->host);
                        return 0;
                }
                if(sldns_buffer_remaining(pkt) < 10) {
                        verbose(VERB_ALGO, "xfr to %s failed, packet with "
                                "truncated RR",
                                xfr->task_transfer->master->host);
                        return 0;
                }
                (void)sldns_buffer_read_u16(pkt); /* type */
                (void)sldns_buffer_read_u16(pkt); /* class */
                (void)sldns_buffer_read_u32(pkt); /* ttl */
                rdlen = sldns_buffer_read_u16(pkt);
                if(sldns_buffer_remaining(pkt) < rdlen) {
                        verbose(VERB_ALGO, "xfr to %s failed, packet with "
                                "truncated RR rdata",
                                xfr->task_transfer->master->host);
                        return 0;
                }
                /* skip over RR rdata to go to the next RR */
                sldns_buffer_skip(pkt, (ssize_t)rdlen);
        }

        /* check additional section */
        for(i=0; i<(int)LDNS_ARCOUNT(wire); i++) {
                uint16_t rdlen;
                if(pkt_dname_len(pkt) == 0) {
                        verbose(VERB_ALGO, "xfr to %s failed, packet with "
                                "malformed dname in additional section",
                                xfr->task_transfer->master->host);
                        return 0;
                }
                if(sldns_buffer_remaining(pkt) < 10) {
                        verbose(VERB_ALGO, "xfr to %s failed, packet with "
                                "truncated RR",
                                xfr->task_transfer->master->host);
                        return 0;
                }
                (void)sldns_buffer_read_u16(pkt); /* type */
                (void)sldns_buffer_read_u16(pkt); /* class */
                (void)sldns_buffer_read_u32(pkt); /* ttl */
                rdlen = sldns_buffer_read_u16(pkt);
                if(sldns_buffer_remaining(pkt) < rdlen) {
                        verbose(VERB_ALGO, "xfr to %s failed, packet with "
                                "truncated RR rdata",
                                xfr->task_transfer->master->host);
                        return 0;
                }
                /* skip over RR rdata to go to the next RR */
                sldns_buffer_skip(pkt, (ssize_t)rdlen);
        }

        return 1;
}

/** Link the data from this packet into the worklist of transferred data */
static int
xfer_link_data(sldns_buffer* pkt, struct auth_xfer* xfr)
{
        /* alloc it */
        struct auth_chunk* e;
        e = (struct auth_chunk*)calloc(1, sizeof(*e));
        if(!e) return 0;
        e->next = NULL;
        e->len = sldns_buffer_limit(pkt);
        e->data = memdup(sldns_buffer_begin(pkt), e->len);
        if(!e->data) {
                free(e);
                return 0;
        }

        /* alloc succeeded, link into list */
        if(!xfr->task_transfer->chunks_first)
                xfr->task_transfer->chunks_first = e;
        if(xfr->task_transfer->chunks_last)
                xfr->task_transfer->chunks_last->next = e;
        xfr->task_transfer->chunks_last = e;
        return 1;
}

/** task transfer.  the list of data is complete. process it and if failed
 * move to next master, if succeeded, end the task transfer */
static void
process_list_end_transfer(struct auth_xfer* xfr, struct module_env* env)
{
        int ixfr_fail = 0;
        if(xfr_process_chunk_list(xfr, env, &ixfr_fail)) {
                /* it worked! */
                auth_chunks_delete(xfr->task_transfer);

                /* we fetched the zone, move to wait task */
                xfr_transfer_disown(xfr);

                if(xfr->notify_received && (!xfr->notify_has_serial ||
                        (xfr->notify_has_serial && 
                        xfr_serial_means_update(xfr, xfr->notify_serial)))) {
                        uint32_t sr = xfr->notify_serial;
                        int has_sr = xfr->notify_has_serial;
                        /* we received a notify while probe/transfer was
                         * in progress.  start a new probe and transfer */
                        xfr->notify_received = 0;
                        xfr->notify_has_serial = 0;
                        xfr->notify_serial = 0;
                        if(!xfr_start_probe(xfr, env, NULL)) {
                                /* if we couldn't start it, already in
                                 * progress; restore notify serial,
                                 * while xfr still locked */
                                xfr->notify_received = 1;
                                xfr->notify_has_serial = has_sr;
                                xfr->notify_serial = sr;
                                lock_basic_unlock(&xfr->lock);
                        }
                        return;
                } else {
                        /* pick up the nextprobe task and wait (normail wait time) */
                        if(xfr->task_nextprobe->worker == NULL)
                                xfr_set_timeout(xfr, env, 0, 0);
                }
                lock_basic_unlock(&xfr->lock);
                return;
        }
        /* processing failed */
        /* when done, delete data from list */
        auth_chunks_delete(xfr->task_transfer);
        if(ixfr_fail) {
                xfr->task_transfer->ixfr_fail = 1;
        } else {
                xfr_transfer_nextmaster(xfr);
        }
        xfr_transfer_nexttarget_or_end(xfr, env);
}

/** callback for the task_transfer timer */
void
auth_xfer_transfer_timer_callback(void* arg)
{
        struct auth_xfer* xfr = (struct auth_xfer*)arg;
        struct module_env* env;
        int gonextonfail = 1;
        log_assert(xfr->task_transfer);
        lock_basic_lock(&xfr->lock);
        env = xfr->task_transfer->env;
        if(!env || env->outnet->want_to_quit) {
                lock_basic_unlock(&xfr->lock);
                return; /* stop on quit */
        }

        verbose(VERB_ALGO, "xfr stopped, connection timeout to %s",
                xfr->task_transfer->master->host);

        /* see if IXFR caused the failure, if so, try AXFR */
        if(xfr->task_transfer->on_ixfr) {
                xfr->task_transfer->ixfr_possible_timeout_count++;
                if(xfr->task_transfer->ixfr_possible_timeout_count >=
                        NUM_TIMEOUTS_FALLBACK_IXFR) {
                        verbose(VERB_ALGO, "xfr to %s, fallback "
                                "from IXFR to AXFR (because of timeouts)",
                                xfr->task_transfer->master->host);
                        xfr->task_transfer->ixfr_fail = 1;
                        gonextonfail = 0;
                }
        }

        /* delete transferred data from list */
        auth_chunks_delete(xfr->task_transfer);
        comm_point_delete(xfr->task_transfer->cp);
        xfr->task_transfer->cp = NULL;
        if(gonextonfail)
                xfr_transfer_nextmaster(xfr);
        xfr_transfer_nexttarget_or_end(xfr, env);
}

/** callback for task_transfer tcp connections */
int
auth_xfer_transfer_tcp_callback(struct comm_point* c, void* arg, int err,
        struct comm_reply* ATTR_UNUSED(repinfo))
{
        struct auth_xfer* xfr = (struct auth_xfer*)arg;
        struct module_env* env;
        int gonextonfail = 1;
        int transferdone = 0;
        log_assert(xfr->task_transfer);
        lock_basic_lock(&xfr->lock);
        env = xfr->task_transfer->env;
        if(!env || env->outnet->want_to_quit) {
                lock_basic_unlock(&xfr->lock);
                return 0; /* stop on quit */
        }
        /* stop the timer */
        comm_timer_disable(xfr->task_transfer->timer);

        if(err != NETEVENT_NOERROR) {
                /* connection failed, closed, or timeout */
                /* stop this transfer, cleanup 
                 * and continue task_transfer*/
                verbose(VERB_ALGO, "xfr stopped, connection lost to %s",
                        xfr->task_transfer->master->host);

                /* see if IXFR caused the failure, if so, try AXFR */
                if(xfr->task_transfer->on_ixfr) {
                        xfr->task_transfer->ixfr_possible_timeout_count++;
                        if(xfr->task_transfer->ixfr_possible_timeout_count >=
                                NUM_TIMEOUTS_FALLBACK_IXFR) {
                                verbose(VERB_ALGO, "xfr to %s, fallback "
                                        "from IXFR to AXFR (because of timeouts)",
                                        xfr->task_transfer->master->host);
                                xfr->task_transfer->ixfr_fail = 1;
                                gonextonfail = 0;
                        }
                }

        failed:
                /* delete transferred data from list */
                auth_chunks_delete(xfr->task_transfer);
                comm_point_delete(xfr->task_transfer->cp);
                xfr->task_transfer->cp = NULL;
                if(gonextonfail)
                        xfr_transfer_nextmaster(xfr);
                xfr_transfer_nexttarget_or_end(xfr, env);
                return 0;
        }
        /* note that IXFR worked without timeout */
        if(xfr->task_transfer->on_ixfr)
                xfr->task_transfer->ixfr_possible_timeout_count = 0;

        /* handle returned packet */
        /* if it fails, cleanup and end this transfer */
        /* if it needs to fallback from IXFR to AXFR, do that */
        if(!check_xfer_packet(c->buffer, xfr, &gonextonfail, &transferdone)) {
                goto failed;
        }
        /* if it is good, link it into the list of data */
        /* if the link into list of data fails (malloc fail) cleanup and end */
        if(!xfer_link_data(c->buffer, xfr)) {
                verbose(VERB_ALGO, "xfr stopped to %s, malloc failed",
                        xfr->task_transfer->master->host);
                goto failed;
        }
        /* if the transfer is done now, disconnect and process the list */
        if(transferdone) {
                comm_point_delete(xfr->task_transfer->cp);
                xfr->task_transfer->cp = NULL;
                process_list_end_transfer(xfr, env);
                return 0;
        }

        /* if we want to read more messages, setup the commpoint to read
         * a DNS packet, and the timeout */
        lock_basic_unlock(&xfr->lock);
        c->tcp_is_reading = 1;
        sldns_buffer_clear(c->buffer);
        comm_point_start_listening(c, -1, AUTH_TRANSFER_TIMEOUT);
        return 0;
}

/** callback for task_transfer http connections */
int
auth_xfer_transfer_http_callback(struct comm_point* c, void* arg, int err,
        struct comm_reply* repinfo)
{
        struct auth_xfer* xfr = (struct auth_xfer*)arg;
        struct module_env* env;
        log_assert(xfr->task_transfer);
        lock_basic_lock(&xfr->lock);
        env = xfr->task_transfer->env;
        if(!env || env->outnet->want_to_quit) {
                lock_basic_unlock(&xfr->lock);
                return 0; /* stop on quit */
        }
        verbose(VERB_ALGO, "auth zone transfer http callback");
        /* stop the timer */
        comm_timer_disable(xfr->task_transfer->timer);

        if(err != NETEVENT_NOERROR && err != NETEVENT_DONE) {
                /* connection failed, closed, or timeout */
                /* stop this transfer, cleanup 
                 * and continue task_transfer*/
                verbose(VERB_ALGO, "http stopped, connection lost to %s",
                        xfr->task_transfer->master->host);
        failed:
                /* delete transferred data from list */
                auth_chunks_delete(xfr->task_transfer);
                if(repinfo) repinfo->c = NULL; /* signal cp deleted to
                                the routine calling this callback */
                comm_point_delete(xfr->task_transfer->cp);
                xfr->task_transfer->cp = NULL;
                xfr_transfer_nextmaster(xfr);
                xfr_transfer_nexttarget_or_end(xfr, env);
                return 0;
        }

        /* if it is good, link it into the list of data */
        /* if the link into list of data fails (malloc fail) cleanup and end */
        if(sldns_buffer_limit(c->buffer) > 0) {
                verbose(VERB_ALGO, "auth zone http queued up %d bytes",
                        (int)sldns_buffer_limit(c->buffer));
                if(!xfer_link_data(c->buffer, xfr)) {
                        verbose(VERB_ALGO, "http stopped to %s, malloc failed",
                                xfr->task_transfer->master->host);
                        goto failed;
                }
        }
        /* if the transfer is done now, disconnect and process the list */
        if(err == NETEVENT_DONE) {
                if(repinfo) repinfo->c = NULL; /* signal cp deleted to
                                the routine calling this callback */
                comm_point_delete(xfr->task_transfer->cp);
                xfr->task_transfer->cp = NULL;
                process_list_end_transfer(xfr, env);
                return 0;
        }

        /* if we want to read more messages, setup the commpoint to read
         * a DNS packet, and the timeout */
        lock_basic_unlock(&xfr->lock);
        c->tcp_is_reading = 1;
        sldns_buffer_clear(c->buffer);
        comm_point_start_listening(c, -1, AUTH_TRANSFER_TIMEOUT);
        return 0;
}


/** start transfer task by this worker , xfr is locked. */
static void
xfr_start_transfer(struct auth_xfer* xfr, struct module_env* env,
        struct auth_master* master)
{
        log_assert(xfr->task_transfer != NULL);
        log_assert(xfr->task_transfer->worker == NULL);
        log_assert(xfr->task_transfer->chunks_first == NULL);
        log_assert(xfr->task_transfer->chunks_last == NULL);
        xfr->task_transfer->worker = env->worker;
        xfr->task_transfer->env = env;

        /* init transfer process */
        /* find that master in the transfer's list of masters? */
        xfr_transfer_start_list(xfr, master);
        /* start lookup for hostnames in transfer master list */
        xfr_transfer_start_lookups(xfr);

        /* initiate TCP, and set timeout on it */
        xfr_transfer_nexttarget_or_end(xfr, env);
}

/** disown task_probe.  caller must hold xfr.lock */
static void
xfr_probe_disown(struct auth_xfer* xfr)
{
        /* remove timer (from this worker's event base) */
        comm_timer_delete(xfr->task_probe->timer);
        xfr->task_probe->timer = NULL;
        /* remove the commpoint */
        comm_point_delete(xfr->task_probe->cp);
        xfr->task_probe->cp = NULL;
        /* we don't own this item anymore */
        xfr->task_probe->worker = NULL;
        xfr->task_probe->env = NULL;
}

/** send the UDP probe to the master, this is part of task_probe */
static int
xfr_probe_send_probe(struct auth_xfer* xfr, struct module_env* env,
        int timeout)
{
        struct sockaddr_storage addr;
        socklen_t addrlen = 0;
        struct timeval t;
        /* pick master */
        struct auth_master* master = xfr_probe_current_master(xfr);
        char *auth_name = NULL;
        if(!master) return 0;
        if(master->allow_notify) return 0; /* only for notify */
        if(master->http) return 0; /* only masters get SOA UDP probe,
                not urls, if those are in this list */

        /* get master addr */
        if(xfr->task_probe->scan_addr) {
                addrlen = xfr->task_probe->scan_addr->addrlen;
                memmove(&addr, &xfr->task_probe->scan_addr->addr, addrlen);
        } else {
                if(!authextstrtoaddr(master->host, &addr, &addrlen, &auth_name)) {
                        /* the ones that are not in addr format are supposed
                         * to be looked up.  The lookup has failed however,
                         * so skip them */
                        char zname[LDNS_MAX_DOMAINLEN];
                        dname_str(xfr->name, zname);
                        log_err("%s: failed lookup, cannot probe to master %s",
                                zname, master->host);
                        return 0;
                }
                if (auth_name != NULL) {
                        if (addr.ss_family == AF_INET
                        &&  (int)ntohs(((struct sockaddr_in *)&addr)->sin_port)
                            == env->cfg->ssl_port)
                                ((struct sockaddr_in *)&addr)->sin_port
                                        = htons((uint16_t)env->cfg->port);
                        else if (addr.ss_family == AF_INET6
                        &&  (int)ntohs(((struct sockaddr_in6 *)&addr)->sin6_port)
                            == env->cfg->ssl_port)
                                ((struct sockaddr_in6 *)&addr)->sin6_port
                                        = htons((uint16_t)env->cfg->port);
                }
        }

        /* create packet */
        /* create new ID for new probes, but not on timeout retries,
         * this means we'll accept replies to previous retries to same ip */
        if(timeout == AUTH_PROBE_TIMEOUT)
                xfr->task_probe->id = GET_RANDOM_ID(env->rnd);
        xfr_create_soa_probe_packet(xfr, env->scratch_buffer, 
                xfr->task_probe->id);
        /* we need to remove the cp if we have a different ip4/ip6 type now */
        if(xfr->task_probe->cp &&
                ((xfr->task_probe->cp_is_ip6 && !addr_is_ip6(&addr, addrlen)) ||
                (!xfr->task_probe->cp_is_ip6 && addr_is_ip6(&addr, addrlen)))
                ) {
                comm_point_delete(xfr->task_probe->cp);
                xfr->task_probe->cp = NULL;
        }
        if(!xfr->task_probe->cp) {
                if(addr_is_ip6(&addr, addrlen))
                        xfr->task_probe->cp_is_ip6 = 1;
                else    xfr->task_probe->cp_is_ip6 = 0;
                xfr->task_probe->cp = outnet_comm_point_for_udp(env->outnet,
                        auth_xfer_probe_udp_callback, xfr, &addr, addrlen);
                if(!xfr->task_probe->cp) {
                        char zname[LDNS_MAX_DOMAINLEN], as[256];
                        dname_str(xfr->name, zname);
                        addr_port_to_str(&addr, addrlen, as, sizeof(as));
                        verbose(VERB_ALGO, "cannot create udp cp for "
                                "probe %s to %s", zname, as);
                        return 0;
                }
        }
        if(!xfr->task_probe->timer) {
                xfr->task_probe->timer = comm_timer_create(env->worker_base,
                        auth_xfer_probe_timer_callback, xfr);
                if(!xfr->task_probe->timer) {
                        log_err("malloc failure");
                        return 0;
                }
        }

        /* send udp packet */
        if(!comm_point_send_udp_msg(xfr->task_probe->cp, env->scratch_buffer,
                (struct sockaddr*)&addr, addrlen, 0)) {
                char zname[LDNS_MAX_DOMAINLEN], as[256];
                dname_str(xfr->name, zname);
                addr_port_to_str(&addr, addrlen, as, sizeof(as));
                verbose(VERB_ALGO, "failed to send soa probe for %s to %s",
                        zname, as);
                return 0;
        }
        if(verbosity >= VERB_ALGO) {
                char zname[LDNS_MAX_DOMAINLEN], as[256];
                dname_str(xfr->name, zname);
                addr_port_to_str(&addr, addrlen, as, sizeof(as));
                verbose(VERB_ALGO, "auth zone %s soa probe sent to %s", zname,
                        as);
        }
        xfr->task_probe->timeout = timeout;
#ifndef S_SPLINT_S
        t.tv_sec = timeout/1000;
        t.tv_usec = (timeout%1000)*1000;
#endif
        comm_timer_set(xfr->task_probe->timer, &t);

        return 1;
}

/** callback for task_probe timer */
void
auth_xfer_probe_timer_callback(void* arg)
{
        struct auth_xfer* xfr = (struct auth_xfer*)arg;
        struct module_env* env;
        log_assert(xfr->task_probe);
        lock_basic_lock(&xfr->lock);
        env = xfr->task_probe->env;
        if(!env || env->outnet->want_to_quit) {
                lock_basic_unlock(&xfr->lock);
                return; /* stop on quit */
        }

        if(verbosity >= VERB_ALGO) {
                char zname[LDNS_MAX_DOMAINLEN];
                dname_str(xfr->name, zname);
                verbose(VERB_ALGO, "auth zone %s soa probe timeout", zname);
        }
        if(xfr->task_probe->timeout <= AUTH_PROBE_TIMEOUT_STOP) {
                /* try again with bigger timeout */
                if(xfr_probe_send_probe(xfr, env, xfr->task_probe->timeout*2)) {
                        lock_basic_unlock(&xfr->lock);
                        return;
                }
        }
        /* delete commpoint so a new one is created, with a fresh port nr */
        comm_point_delete(xfr->task_probe->cp);
        xfr->task_probe->cp = NULL;

        /* too many timeouts (or fail to send), move to next or end */
        xfr_probe_nextmaster(xfr);
        xfr_probe_send_or_end(xfr, env);
}

/** callback for task_probe udp packets */
int
auth_xfer_probe_udp_callback(struct comm_point* c, void* arg, int err,
        struct comm_reply* repinfo)
{
        struct auth_xfer* xfr = (struct auth_xfer*)arg;
        struct module_env* env;
        log_assert(xfr->task_probe);
        lock_basic_lock(&xfr->lock);
        env = xfr->task_probe->env;
        if(!env || env->outnet->want_to_quit) {
                lock_basic_unlock(&xfr->lock);
                return 0; /* stop on quit */
        }

        /* the comm_point_udp_callback is in a for loop for NUM_UDP_PER_SELECT
         * and we set rep.c=NULL to stop if from looking inside the commpoint*/
        repinfo->c = NULL;
        /* stop the timer */
        comm_timer_disable(xfr->task_probe->timer);

        /* see if we got a packet and what that means */
        if(err == NETEVENT_NOERROR) {
                uint32_t serial = 0;
                if(check_packet_ok(c->buffer, LDNS_RR_TYPE_SOA, xfr,
                        &serial)) {
                        /* successful lookup */
                        if(verbosity >= VERB_ALGO) {
                                char buf[LDNS_MAX_DOMAINLEN];
                                dname_str(xfr->name, buf);
                                verbose(VERB_ALGO, "auth zone %s: soa probe "
                                        "serial is %u", buf, (unsigned)serial);
                        }
                        /* see if this serial indicates that the zone has
                         * to be updated */
                        if(xfr_serial_means_update(xfr, serial)) {
                                /* if updated, start the transfer task, if needed */
                                verbose(VERB_ALGO, "auth_zone updated, start transfer");
                                if(xfr->task_transfer->worker == NULL) {
                                        struct auth_master* master =
                                                xfr_probe_current_master(xfr);
                                        /* if we have download URLs use them
                                         * in preference to this master we
                                         * just probed the SOA from */
                                        if(xfr->task_transfer->masters &&
                                                xfr->task_transfer->masters->http)
                                                master = NULL;
                                        xfr_probe_disown(xfr);
                                        xfr_start_transfer(xfr, env, master);
                                        return 0;

                                }
                                /* other tasks are running, we don't do this anymore */
                                xfr_probe_disown(xfr);
                                lock_basic_unlock(&xfr->lock);
                                /* return, we don't sent a reply to this udp packet,
                                 * and we setup the tasks to do next */
                                return 0;
                        } else {
                                verbose(VERB_ALGO, "auth_zone master reports unchanged soa serial");
                                /* we if cannot find updates amongst the
                                 * masters, this means we then have a new lease
                                 * on the zone */
                                xfr->task_probe->have_new_lease = 1;
                        }
                } else {
                        if(verbosity >= VERB_ALGO) {
                                char buf[LDNS_MAX_DOMAINLEN];
                                dname_str(xfr->name, buf);
                                verbose(VERB_ALGO, "auth zone %s: bad reply to soa probe", buf);
                        }
                }
        } else {
                if(verbosity >= VERB_ALGO) {
                        char buf[LDNS_MAX_DOMAINLEN];
                        dname_str(xfr->name, buf);
                        verbose(VERB_ALGO, "auth zone %s: soa probe failed", buf);
                }
        }
        
        /* failed lookup or not an update */
        /* delete commpoint so a new one is created, with a fresh port nr */
        comm_point_delete(xfr->task_probe->cp);
        xfr->task_probe->cp = NULL;

        /* if the result was not a successful probe, we need
         * to send the next one */
        xfr_probe_nextmaster(xfr);
        xfr_probe_send_or_end(xfr, env);
        return 0;
}

/** lookup a host name for its addresses, if needed */
static int
xfr_probe_lookup_host(struct auth_xfer* xfr, struct module_env* env)
{
        struct sockaddr_storage addr;
        socklen_t addrlen = 0;
        struct auth_master* master = xfr->task_probe->lookup_target;
        struct query_info qinfo;
        uint16_t qflags = BIT_RD;
        uint8_t dname[LDNS_MAX_DOMAINLEN+1];
        struct edns_data edns;
        sldns_buffer* buf = env->scratch_buffer;
        if(!master) return 0;
        if(extstrtoaddr(master->host, &addr, &addrlen, UNBOUND_DNS_PORT)) {
                /* not needed, host is in IP addr format */
                return 0;
        }
        if(master->allow_notify && !master->http &&
                strchr(master->host, '/') != NULL &&
                strchr(master->host, '/') == strrchr(master->host, '/')) {
                return 0; /* is IP/prefix format, not something to look up */
        }

        /* use mesh_new_callback to probe for non-addr hosts,
         * and then wait for them to be looked up (in cache, or query) */
        qinfo.qname_len = sizeof(dname);
        if(sldns_str2wire_dname_buf(master->host, dname, &qinfo.qname_len)
                != 0) {
                log_err("cannot parse host name of master %s", master->host);
                return 0;
        }
        qinfo.qname = dname;
        qinfo.qclass = xfr->dclass;
        qinfo.qtype = LDNS_RR_TYPE_A;
        if(xfr->task_probe->lookup_aaaa)
                qinfo.qtype = LDNS_RR_TYPE_AAAA;
        qinfo.local_alias = NULL;
        if(verbosity >= VERB_ALGO) {
                char buf1[512];
                char buf2[LDNS_MAX_DOMAINLEN];
                dname_str(xfr->name, buf2);
                snprintf(buf1, sizeof(buf1), "auth zone %s: master lookup"
                        " for task_probe", buf2);
                log_query_info(VERB_ALGO, buf1, &qinfo);
        }
        edns.edns_present = 1;
        edns.ext_rcode = 0;
        edns.edns_version = 0;
        edns.bits = EDNS_DO;
        edns.opt_list_in = NULL;
        edns.opt_list_out = NULL;
        edns.opt_list_inplace_cb_out = NULL;
        edns.padding_block_size = 0;
        edns.cookie_present = 0;
        edns.cookie_valid = 0;
        if(sldns_buffer_capacity(buf) < 65535)
                edns.udp_size = (uint16_t)sldns_buffer_capacity(buf);
        else    edns.udp_size = 65535;

        /* unlock xfr during mesh_new_callback() because the callback can be
         * called straight away */
        lock_basic_unlock(&xfr->lock);
        if(!mesh_new_callback(env->mesh, &qinfo, qflags, &edns, buf, 0,
                &auth_xfer_probe_lookup_callback, xfr, 0)) {
                lock_basic_lock(&xfr->lock);
                log_err("out of memory lookup up master %s", master->host);
                return 0;
        }
        lock_basic_lock(&xfr->lock);
        return 1;
}

/** move to sending the probe packets, next if fails. task_probe */
static void
xfr_probe_send_or_end(struct auth_xfer* xfr, struct module_env* env)
{
        /* are we doing hostname lookups? */
        while(xfr->task_probe->lookup_target) {
                if(xfr_probe_lookup_host(xfr, env)) {
                        /* wait for lookup to finish,
                         * note that the hostname may be in unbound's cache
                         * and we may then get an instant cache response,
                         * and that calls the callback just like a full
                         * lookup and lookup failures also call callback */
                        if(verbosity >= VERB_ALGO) {
                                char zname[LDNS_MAX_DOMAINLEN];
                                dname_str(xfr->name, zname);
                                verbose(VERB_ALGO, "auth zone %s probe next target lookup", zname);
                        }
                        lock_basic_unlock(&xfr->lock);
                        return;
                }
                xfr_probe_move_to_next_lookup(xfr, env);
        }
        /* probe of list has ended.  Create or refresh the list of of
         * allow_notify addrs */
        probe_copy_masters_for_allow_notify(xfr);
        if(verbosity >= VERB_ALGO) {
                char zname[LDNS_MAX_DOMAINLEN];
                dname_str(xfr->name, zname);
                verbose(VERB_ALGO, "auth zone %s probe: notify addrs updated", zname);
        }
        if(xfr->task_probe->only_lookup) {
                /* only wanted lookups for copy, stop probe and start wait */
                xfr->task_probe->only_lookup = 0;
                if(verbosity >= VERB_ALGO) {
                        char zname[LDNS_MAX_DOMAINLEN];
                        dname_str(xfr->name, zname);
                        verbose(VERB_ALGO, "auth zone %s probe: finished only_lookup", zname);
                }
                xfr_probe_disown(xfr);
                if(xfr->task_nextprobe->worker == NULL)
                        xfr_set_timeout(xfr, env, 0, 0);
                lock_basic_unlock(&xfr->lock);
                return;
        }

        /* send probe packets */
        while(!xfr_probe_end_of_list(xfr)) {
                if(xfr_probe_send_probe(xfr, env, AUTH_PROBE_TIMEOUT)) {
                        /* successfully sent probe, wait for callback */
                        lock_basic_unlock(&xfr->lock);
                        return;
                }
                /* failed to send probe, next master */
                xfr_probe_nextmaster(xfr);
        }

        /* done with probe sequence, wait */
        if(xfr->task_probe->have_new_lease) {
                /* if zone not updated, start the wait timer again */
                if(verbosity >= VERB_ALGO) {
                        char zname[LDNS_MAX_DOMAINLEN];
                        dname_str(xfr->name, zname);
                        verbose(VERB_ALGO, "auth_zone %s unchanged, new lease, wait", zname);
                }
                xfr_probe_disown(xfr);
                if(xfr->have_zone)
                        xfr->lease_time = *env->now;
                if(xfr->task_nextprobe->worker == NULL)
                        xfr_set_timeout(xfr, env, 0, 0);
        } else {
                if(verbosity >= VERB_ALGO) {
                        char zname[LDNS_MAX_DOMAINLEN];
                        dname_str(xfr->name, zname);
                        verbose(VERB_ALGO, "auth zone %s soa probe failed, wait to retry", zname);
                }
                /* we failed to send this as well, move to the wait task,
                 * use the shorter retry timeout */
                xfr_probe_disown(xfr);
                /* pick up the nextprobe task and wait */
                if(xfr->task_nextprobe->worker == NULL)
                        xfr_set_timeout(xfr, env, 1, 0);
        }

        lock_basic_unlock(&xfr->lock);
}

/** callback for task_probe lookup of host name, of A or AAAA */
void auth_xfer_probe_lookup_callback(void* arg, int rcode, sldns_buffer* buf,
        enum sec_status ATTR_UNUSED(sec), char* ATTR_UNUSED(why_bogus),
        int ATTR_UNUSED(was_ratelimited))
{
        struct auth_xfer* xfr = (struct auth_xfer*)arg;
        struct module_env* env;
        log_assert(xfr->task_probe);
        lock_basic_lock(&xfr->lock);
        env = xfr->task_probe->env;
        if(!env || env->outnet->want_to_quit) {
                lock_basic_unlock(&xfr->lock);
                return; /* stop on quit */
        }

        /* process result */
        if(rcode == LDNS_RCODE_NOERROR) {
                uint16_t wanted_qtype = LDNS_RR_TYPE_A;
                struct regional* temp = env->scratch;
                struct query_info rq;
                struct reply_info* rep;
                if(xfr->task_probe->lookup_aaaa)
                        wanted_qtype = LDNS_RR_TYPE_AAAA;
                memset(&rq, 0, sizeof(rq));
                rep = parse_reply_in_temp_region(buf, temp, &rq);
                if(rep && rq.qtype == wanted_qtype &&
                        FLAGS_GET_RCODE(rep->flags) == LDNS_RCODE_NOERROR) {
                        /* parsed successfully */
                        struct ub_packed_rrset_key* answer =
                                reply_find_answer_rrset(&rq, rep);
                        if(answer) {
                                xfr_master_add_addrs(xfr->task_probe->
                                        lookup_target, answer, wanted_qtype);
                        } else {
                                if(verbosity >= VERB_ALGO) {
                                        char zname[LDNS_MAX_DOMAINLEN];
                                        dname_str(xfr->name, zname);
                                        verbose(VERB_ALGO, "auth zone %s host %s type %s probe lookup has nodata", zname, xfr->task_probe->lookup_target->host, (xfr->task_probe->lookup_aaaa?"AAAA":"A"));
                                }
                        }
                } else {
                        if(verbosity >= VERB_ALGO) {
                                char zname[LDNS_MAX_DOMAINLEN];
                                dname_str(xfr->name, zname);
                                verbose(VERB_ALGO, "auth zone %s host %s type %s probe lookup has no address", zname, xfr->task_probe->lookup_target->host, (xfr->task_probe->lookup_aaaa?"AAAA":"A"));
                        }
                }
                regional_free_all(temp);
        } else {
                if(verbosity >= VERB_ALGO) {
                        char zname[LDNS_MAX_DOMAINLEN];
                        dname_str(xfr->name, zname);
                        verbose(VERB_ALGO, "auth zone %s host %s type %s probe lookup failed", zname, xfr->task_probe->lookup_target->host, (xfr->task_probe->lookup_aaaa?"AAAA":"A"));
                }
        }
        if(xfr->task_probe->lookup_target->list &&
                xfr->task_probe->lookup_target == xfr_probe_current_master(xfr))
                xfr->task_probe->scan_addr = xfr->task_probe->lookup_target->list;

        /* move to lookup AAAA after A lookup, move to next hostname lookup,
         * or move to send the probes, or, if nothing to do, end task_probe */
        xfr_probe_move_to_next_lookup(xfr, env);
        xfr_probe_send_or_end(xfr, env);
}

/** disown task_nextprobe.  caller must hold xfr.lock */
static void
xfr_nextprobe_disown(struct auth_xfer* xfr)
{
        /* delete the timer, because the next worker to pick this up may
         * not have the same event base */
        comm_timer_delete(xfr->task_nextprobe->timer);
        xfr->task_nextprobe->timer = NULL;
        xfr->task_nextprobe->next_probe = 0;
        /* we don't own this item anymore */
        xfr->task_nextprobe->worker = NULL;
        xfr->task_nextprobe->env = NULL;
}

/** xfer nextprobe timeout callback, this is part of task_nextprobe */
void
auth_xfer_timer(void* arg)
{
        struct auth_xfer* xfr = (struct auth_xfer*)arg;
        struct module_env* env;
        log_assert(xfr->task_nextprobe);
        lock_basic_lock(&xfr->lock);
        env = xfr->task_nextprobe->env;
        if(!env || env->outnet->want_to_quit) {
                lock_basic_unlock(&xfr->lock);
                return; /* stop on quit */
        }

        /* see if zone has expired, and if so, also set auth_zone expired */
        if(xfr->have_zone && !xfr->zone_expired &&
           *env->now >= xfr->lease_time + xfr->expiry) {
                lock_basic_unlock(&xfr->lock);
                auth_xfer_set_expired(xfr, env, 1);
                lock_basic_lock(&xfr->lock);
        }

        xfr_nextprobe_disown(xfr);

        if(!xfr_start_probe(xfr, env, NULL)) {
                /* not started because already in progress */
                lock_basic_unlock(&xfr->lock);
        }
}

/** return true if there are probe (SOA UDP query) targets in the master list*/
static int
have_probe_targets(struct auth_master* list)
{
        struct auth_master* p;
        for(p=list; p; p = p->next) {
                if(!p->allow_notify && p->host)
                        return 1;
        }
        return 0;
}

/** start task_probe if possible, if no masters for probe start task_transfer
 * returns true if task has been started, and false if the task is already
 * in progress. */
static int
xfr_start_probe(struct auth_xfer* xfr, struct module_env* env,
        struct auth_master* spec)
{
        /* see if we need to start a probe (or maybe it is already in
         * progress (due to notify)) */
        if(xfr->task_probe->worker == NULL) {
                if(!have_probe_targets(xfr->task_probe->masters) &&
                        !(xfr->task_probe->only_lookup &&
                        xfr->task_probe->masters != NULL)) {
                        /* useless to pick up task_probe, no masters to
                         * probe. Instead attempt to pick up task transfer */
                        if(xfr->task_transfer->worker == NULL) {
                                xfr_start_transfer(xfr, env, spec);
                                return 1;
                        }
                        /* task transfer already in progress */
                        return 0;
                }

                /* pick up the probe task ourselves */
                xfr->task_probe->worker = env->worker;
                xfr->task_probe->env = env;
                xfr->task_probe->cp = NULL;

                /* start the task */
                /* have not seen a new lease yet, this scan */
                xfr->task_probe->have_new_lease = 0;
                /* if this was a timeout, no specific first master to scan */
                /* otherwise, spec is nonNULL the notified master, scan
                 * first and also transfer first from it */
                xfr_probe_start_list(xfr, spec);
                /* setup to start the lookup of hostnames of masters afresh */
                xfr_probe_start_lookups(xfr);
                /* send the probe packet or next send, or end task */
                xfr_probe_send_or_end(xfr, env);
                return 1;
        }
        return 0;
}

/** for task_nextprobe.
 * determine next timeout for auth_xfer. Also (re)sets timer.
 * @param xfr: task structure
 * @param env: module environment, with worker and time.
 * @param failure: set true if timer should be set for failure retry.
 * @param lookup_only: only perform lookups when timer done, 0 sec timeout
 */
static void
xfr_set_timeout(struct auth_xfer* xfr, struct module_env* env,
        int failure, int lookup_only)
{
        struct timeval tv;
        log_assert(xfr->task_nextprobe != NULL);
        log_assert(xfr->task_nextprobe->worker == NULL ||
                xfr->task_nextprobe->worker == env->worker);
        /* normally, nextprobe = startoflease + refresh,
         * but if expiry is sooner, use that one.
         * after a failure, use the retry timer instead. */
        xfr->task_nextprobe->next_probe = *env->now;
        if(xfr->lease_time && !failure)
                xfr->task_nextprobe->next_probe = xfr->lease_time;
        
        if(!failure) {
                xfr->task_nextprobe->backoff = 0;
        } else {
                if(xfr->task_nextprobe->backoff == 0)
                                xfr->task_nextprobe->backoff = 3;
                else    xfr->task_nextprobe->backoff *= 2;
                if(xfr->task_nextprobe->backoff > AUTH_TRANSFER_MAX_BACKOFF)
                        xfr->task_nextprobe->backoff =
                                AUTH_TRANSFER_MAX_BACKOFF;
        }

        if(xfr->have_zone) {
                time_t wait = xfr->refresh;
                if(failure) wait = xfr->retry;
                if(xfr->expiry < wait)
                        xfr->task_nextprobe->next_probe += xfr->expiry;
                else    xfr->task_nextprobe->next_probe += wait;
                if(failure)
                        xfr->task_nextprobe->next_probe +=
                                xfr->task_nextprobe->backoff;
                /* put the timer exactly on expiry, if possible */
                if(xfr->lease_time && xfr->lease_time+xfr->expiry <
                        xfr->task_nextprobe->next_probe &&
                        xfr->lease_time+xfr->expiry > *env->now)
                        xfr->task_nextprobe->next_probe =
                                xfr->lease_time+xfr->expiry;
        } else {
                xfr->task_nextprobe->next_probe +=
                        xfr->task_nextprobe->backoff;
        }

        if(!xfr->task_nextprobe->timer) {
                xfr->task_nextprobe->timer = comm_timer_create(
                        env->worker_base, auth_xfer_timer, xfr);
                if(!xfr->task_nextprobe->timer) {
                        /* failed to malloc memory. likely zone transfer
                         * also fails for that. skip the timeout */
                        char zname[LDNS_MAX_DOMAINLEN];
                        dname_str(xfr->name, zname);
                        log_err("cannot allocate timer, no refresh for %s",
                                zname);
                        return;
                }
        }
        xfr->task_nextprobe->worker = env->worker;
        xfr->task_nextprobe->env = env;
        if(*(xfr->task_nextprobe->env->now) <= xfr->task_nextprobe->next_probe)
                tv.tv_sec = xfr->task_nextprobe->next_probe - 
                        *(xfr->task_nextprobe->env->now);
        else    tv.tv_sec = 0;
        if(tv.tv_sec != 0 && lookup_only && xfr->task_probe->masters) {
                /* don't lookup_only, if lookup timeout is 0 anyway,
                 * or if we don't have masters to lookup */
                tv.tv_sec = 0;
                if(xfr->task_probe->worker == NULL)
                        xfr->task_probe->only_lookup = 1;
        }
        if(verbosity >= VERB_ALGO) {
                char zname[LDNS_MAX_DOMAINLEN];
                dname_str(xfr->name, zname);
                verbose(VERB_ALGO, "auth zone %s timeout in %d seconds",
                        zname, (int)tv.tv_sec);
        }
        tv.tv_usec = 0;
        comm_timer_set(xfr->task_nextprobe->timer, &tv);
}

/** initial pick up of worker timeouts, ties events to worker event loop */
void
auth_xfer_pickup_initial(struct auth_zones* az, struct module_env* env)
{
        struct auth_xfer* x;
        lock_rw_wrlock(&az->lock);
        RBTREE_FOR(x, struct auth_xfer*, &az->xtree) {
                lock_basic_lock(&x->lock);
                /* set lease_time, because we now have timestamp in env,
                 * (not earlier during startup and apply_cfg), and this
                 * notes the start time when the data was acquired */
                if(x->have_zone)
                        x->lease_time = *env->now;
                if(x->task_nextprobe && x->task_nextprobe->worker == NULL) {
                        xfr_set_timeout(x, env, 0, 1);
                }
                lock_basic_unlock(&x->lock);
        }
        lock_rw_unlock(&az->lock);
}

void auth_zones_cleanup(struct auth_zones* az)
{
        struct auth_xfer* x;
        lock_rw_wrlock(&az->lock);
        RBTREE_FOR(x, struct auth_xfer*, &az->xtree) {
                lock_basic_lock(&x->lock);
                if(x->task_nextprobe && x->task_nextprobe->worker != NULL) {
                        xfr_nextprobe_disown(x);
                }
                if(x->task_probe && x->task_probe->worker != NULL) {
                        xfr_probe_disown(x);
                }
                if(x->task_transfer && x->task_transfer->worker != NULL) {
                        auth_chunks_delete(x->task_transfer);
                        xfr_transfer_disown(x);
                }
                lock_basic_unlock(&x->lock);
        }
        lock_rw_unlock(&az->lock);
}

/**
 * malloc the xfer and tasks
 * @param z: auth_zone with name of zone.
 */
static struct auth_xfer*
auth_xfer_new(struct auth_zone* z)
{
        struct auth_xfer* xfr;
        xfr = (struct auth_xfer*)calloc(1, sizeof(*xfr));
        if(!xfr) return NULL;
        xfr->name = memdup(z->name, z->namelen);
        if(!xfr->name) {
                free(xfr);
                return NULL;
        }
        xfr->node.key = xfr;
        xfr->namelen = z->namelen;
        xfr->namelabs = z->namelabs;
        xfr->dclass = z->dclass;

        xfr->task_nextprobe = (struct auth_nextprobe*)calloc(1,
                sizeof(struct auth_nextprobe));
        if(!xfr->task_nextprobe) {
                free(xfr->name);
                free(xfr);
                return NULL;
        }
        xfr->task_probe = (struct auth_probe*)calloc(1,
                sizeof(struct auth_probe));
        if(!xfr->task_probe) {
                free(xfr->task_nextprobe);
                free(xfr->name);
                free(xfr);
                return NULL;
        }
        xfr->task_transfer = (struct auth_transfer*)calloc(1,
                sizeof(struct auth_transfer));
        if(!xfr->task_transfer) {
                free(xfr->task_probe);
                free(xfr->task_nextprobe);
                free(xfr->name);
                free(xfr);
                return NULL;
        }

        lock_basic_init(&xfr->lock);
        lock_protect(&xfr->lock, &xfr->name, sizeof(xfr->name));
        lock_protect(&xfr->lock, &xfr->namelen, sizeof(xfr->namelen));
        lock_protect(&xfr->lock, xfr->name, xfr->namelen);
        lock_protect(&xfr->lock, &xfr->namelabs, sizeof(xfr->namelabs));
        lock_protect(&xfr->lock, &xfr->dclass, sizeof(xfr->dclass));
        lock_protect(&xfr->lock, &xfr->notify_received, sizeof(xfr->notify_received));
        lock_protect(&xfr->lock, &xfr->notify_serial, sizeof(xfr->notify_serial));
        lock_protect(&xfr->lock, &xfr->zone_expired, sizeof(xfr->zone_expired));
        lock_protect(&xfr->lock, &xfr->have_zone, sizeof(xfr->have_zone));
        lock_protect(&xfr->lock, &xfr->serial, sizeof(xfr->serial));
        lock_protect(&xfr->lock, &xfr->retry, sizeof(xfr->retry));
        lock_protect(&xfr->lock, &xfr->refresh, sizeof(xfr->refresh));
        lock_protect(&xfr->lock, &xfr->expiry, sizeof(xfr->expiry));
        lock_protect(&xfr->lock, &xfr->lease_time, sizeof(xfr->lease_time));
        lock_protect(&xfr->lock, &xfr->task_nextprobe->worker,
                sizeof(xfr->task_nextprobe->worker));
        lock_protect(&xfr->lock, &xfr->task_probe->worker,
                sizeof(xfr->task_probe->worker));
        lock_protect(&xfr->lock, &xfr->task_transfer->worker,
                sizeof(xfr->task_transfer->worker));
        lock_basic_lock(&xfr->lock);
        return xfr;
}

/** Create auth_xfer structure.
 * This populates the have_zone, soa values, and so on times.
 * and sets the timeout, if a zone transfer is needed a short timeout is set.
 * For that the auth_zone itself must exist (and read in zonefile)
 * returns false on alloc failure. */
struct auth_xfer*
auth_xfer_create(struct auth_zones* az, struct auth_zone* z)
{
        struct auth_xfer* xfr;

        /* malloc it */
        xfr = auth_xfer_new(z);
        if(!xfr) {
                log_err("malloc failure");
                return NULL;
        }
        /* insert in tree */
        (void)rbtree_insert(&az->xtree, &xfr->node);
        return xfr;
}

/** create new auth_master structure */
static struct auth_master*
auth_master_new(struct auth_master*** list)
{
        struct auth_master *m;
        m = (struct auth_master*)calloc(1, sizeof(*m));
        if(!m) {
                log_err("malloc failure");
                return NULL;
        }
        /* set first pointer to m, or next pointer of previous element to m */
        (**list) = m;
        /* store m's next pointer as future point to store at */
        (*list) = &(m->next);
        return m;
}

/** dup_prefix : create string from initial part of other string, malloced */
static char*
dup_prefix(char* str, size_t num)
{
        char* result;
        size_t len = strlen(str);
        if(len < num) num = len; /* not more than strlen */
        result = (char*)malloc(num+1);
        if(!result) {
                log_err("malloc failure");
                return result;
        }
        memmove(result, str, num);
        result[num] = 0;
        return result;
}

/** dup string and print error on error */
static char*
dup_all(char* str)
{
        char* result = strdup(str);
        if(!result) {
                log_err("malloc failure");
                return NULL;
        }
        return result;
}

/** find first of two characters */
static char*
str_find_first_of_chars(char* s, char a, char b)
{
        char* ra = strchr(s, a);
        char* rb = strchr(s, b);
        if(!ra) return rb;
        if(!rb) return ra;
        if(ra < rb) return ra;
        return rb;
}

/** parse URL into host and file parts, false on malloc or parse error */
static int
parse_url(char* url, char** host, char** file, int* port, int* ssl)
{
        char* p = url;
        /* parse http://www.example.com/file.htm
         * or http://127.0.0.1   (index.html)
         * or https://[::1@1234]/a/b/c/d */
        *ssl = 1;
        *port = AUTH_HTTPS_PORT;

        /* parse http:// or https:// */
        if(strncmp(p, "http://", 7) == 0) {
                p += 7;
                *ssl = 0;
                *port = AUTH_HTTP_PORT;
        } else if(strncmp(p, "https://", 8) == 0) {
                p += 8;
        } else if(strstr(p, "://") && strchr(p, '/') > strstr(p, "://") &&
                strchr(p, ':') >= strstr(p, "://")) {
                char* uri = dup_prefix(p, (size_t)(strstr(p, "://")-p));
                log_err("protocol %s:// not supported (for url %s)",
                        uri?uri:"", p);
                free(uri);
                return 0;
        }

        /* parse hostname part */
        if(p[0] == '[') {
                char* end = strchr(p, ']');
                p++; /* skip over [ */
                if(end) {
                        *host = dup_prefix(p, (size_t)(end-p));
                        if(!*host) return 0;
                        p = end+1; /* skip over ] */
                } else {
                        *host = dup_all(p);
                        if(!*host) return 0;
                        p = end;
                }
        } else {
                char* end = str_find_first_of_chars(p, ':', '/');
                if(end) {
                        *host = dup_prefix(p, (size_t)(end-p));
                        if(!*host) return 0;
                } else {
                        *host = dup_all(p);
                        if(!*host) return 0;
                }
                p = end; /* at next : or / or NULL */
        }

        /* parse port number */
        if(p && p[0] == ':') {
                char* end = NULL;
                *port = strtol(p+1, &end, 10);
                p = end;
        }

        /* parse filename part */
        while(p && *p == '/')
                p++;
        if(!p || p[0] == 0)
                *file = strdup("/");
        else    *file = strdup(p);
        if(!*file) {
                log_err("malloc failure");
                return 0;
        }
        return 1;
}

int
xfer_set_masters(struct auth_master** list, struct config_auth* c,
        int with_http)
{
        struct auth_master* m;
        struct config_strlist* p;
        /* list points to the first, or next pointer for the new element */
        while(*list) {
                list = &( (*list)->next );
        }
        if(with_http)
          for(p = c->urls; p; p = p->next) {
                m = auth_master_new(&list);
                if(!m) return 0;
                m->http = 1;
                if(!parse_url(p->str, &m->host, &m->file, &m->port, &m->ssl))
                        return 0;
        }
        for(p = c->masters; p; p = p->next) {
                m = auth_master_new(&list);
                if(!m) return 0;
                m->ixfr = 1; /* this flag is not configurable */
                m->host = strdup(p->str);
                if(!m->host) {
                        log_err("malloc failure");
                        return 0;
                }
        }
        for(p = c->allow_notify; p; p = p->next) {
                m = auth_master_new(&list);
                if(!m) return 0;
                m->allow_notify = 1;
                m->host = strdup(p->str);
                if(!m->host) {
                        log_err("malloc failure");
                        return 0;
                }
        }
        return 1;
}

#define SERIAL_BITS     32
int
compare_serial(uint32_t a, uint32_t b)
{
        const uint32_t cutoff = ((uint32_t) 1 << (SERIAL_BITS - 1));

        if (a == b) {
                return 0;
        } else if ((a < b && b - a < cutoff) || (a > b && a - b > cutoff)) {
                return -1;
        } else {
                return 1;
        }
}

int zonemd_hashalgo_supported(int hashalgo)
{
        if(hashalgo == ZONEMD_ALGO_SHA384) return 1;
        if(hashalgo == ZONEMD_ALGO_SHA512) return 1;
        return 0;
}

int zonemd_scheme_supported(int scheme)
{
        if(scheme == ZONEMD_SCHEME_SIMPLE) return 1;
        return 0;
}

/** initialize hash for hashing with zonemd hash algo */
static struct secalgo_hash* zonemd_digest_init(int hashalgo, char** reason)
{
        struct secalgo_hash *h;
        if(hashalgo == ZONEMD_ALGO_SHA384) {
                /* sha384 */
                h = secalgo_hash_create_sha384();
                if(!h)
                        *reason = "digest sha384 could not be created";
                return h;
        } else if(hashalgo == ZONEMD_ALGO_SHA512) {
                /* sha512 */
                h = secalgo_hash_create_sha512();
                if(!h)
                        *reason = "digest sha512 could not be created";
                return h;
        }
        /* unknown hash algo */
        *reason = "unsupported algorithm";
        return NULL;
}

/** update the hash for zonemd */
static int zonemd_digest_update(int hashalgo, struct secalgo_hash* h,
        uint8_t* data, size_t len, char** reason)
{
        if(hashalgo == ZONEMD_ALGO_SHA384) {
                if(!secalgo_hash_update(h, data, len)) {
                        *reason = "digest sha384 failed";
                        return 0;
                }
                return 1;
        } else if(hashalgo == ZONEMD_ALGO_SHA512) {
                if(!secalgo_hash_update(h, data, len)) {
                        *reason = "digest sha512 failed";
                        return 0;
                }
                return 1;
        }
        /* unknown hash algo */
        *reason = "unsupported algorithm";
        return 0;
}

/** finish the hash for zonemd */
static int zonemd_digest_finish(int hashalgo, struct secalgo_hash* h,
        uint8_t* result, size_t hashlen, size_t* resultlen, char** reason)
{
        if(hashalgo == ZONEMD_ALGO_SHA384) {
                if(hashlen < 384/8) {
                        *reason = "digest buffer too small for sha384";
                        return 0;
                }
                if(!secalgo_hash_final(h, result, hashlen, resultlen)) {
                        *reason = "digest sha384 finish failed";
                        return 0;
                }
                return 1;
        } else if(hashalgo == ZONEMD_ALGO_SHA512) {
                if(hashlen < 512/8) {
                        *reason = "digest buffer too small for sha512";
                        return 0;
                }
                if(!secalgo_hash_final(h, result, hashlen, resultlen)) {
                        *reason = "digest sha512 finish failed";
                        return 0;
                }
                return 1;
        }
        /* unknown algo */
        *reason = "unsupported algorithm";
        return 0;
}

/** add rrsets from node to the list */
static size_t authdata_rrsets_to_list(struct auth_rrset** array,
        size_t arraysize, struct auth_rrset* first)
{
        struct auth_rrset* rrset = first;
        size_t num = 0;
        while(rrset) {
                if(num >= arraysize)
                        return num;
                array[num] = rrset;
                num++;
                rrset = rrset->next;
        }
        return num;
}

/** compare rr list entries */
static int rrlist_compare(const void* arg1, const void* arg2)
{
        struct auth_rrset* r1 = *(struct auth_rrset**)arg1;
        struct auth_rrset* r2 = *(struct auth_rrset**)arg2;
        uint16_t t1, t2;
        if(r1 == NULL) t1 = LDNS_RR_TYPE_RRSIG;
        else t1 = r1->type;
        if(r2 == NULL) t2 = LDNS_RR_TYPE_RRSIG;
        else t2 = r2->type;
        if(t1 < t2)
                return -1;
        if(t1 > t2)
                return 1;
        return 0;
}

/** add type RRSIG to rr list if not one there already,
 * this is to perform RRSIG collate processing at that point. */
static void addrrsigtype_if_needed(struct auth_rrset** array,
        size_t arraysize, size_t* rrnum, struct auth_data* node)
{
        if(az_domain_rrset(node, LDNS_RR_TYPE_RRSIG))
                return; /* already one there */
        if((*rrnum) >= arraysize)
                return; /* array too small? */
        array[*rrnum] = NULL; /* nothing there, but need entry in list */
        (*rrnum)++;
}

/** collate the RRs in an RRset using the simple scheme */
static int zonemd_simple_rrset(struct auth_zone* z, int hashalgo,
        struct secalgo_hash* h, struct auth_data* node,
        struct auth_rrset* rrset, struct regional* region,
        struct sldns_buffer* buf, char** reason)
{
        /* canonicalize */
        struct ub_packed_rrset_key key;
        memset(&key, 0, sizeof(key));
        key.entry.key = &key;
        key.entry.data = rrset->data;
        key.rk.dname = node->name;
        key.rk.dname_len = node->namelen;
        key.rk.type = htons(rrset->type);
        key.rk.rrset_class = htons(z->dclass);
        if(!rrset_canonicalize_to_buffer(region, buf, &key)) {
                *reason = "out of memory";
                return 0;
        }
        regional_free_all(region);

        /* hash */
        if(!zonemd_digest_update(hashalgo, h, sldns_buffer_begin(buf),
                sldns_buffer_limit(buf), reason)) {
                return 0;
        }
        return 1;
}

/** count number of RRSIGs in a domain name rrset list */
static size_t zonemd_simple_count_rrsig(struct auth_rrset* rrset,
        struct auth_rrset** rrlist, size_t rrnum,
        struct auth_zone* z, struct auth_data* node)
{
        size_t i, count = 0;
        if(rrset) {
                size_t j;
                for(j = 0; j<rrset->data->count; j++) {
                        if(rrsig_rdata_get_type_covered(rrset->data->
                                rr_data[j], rrset->data->rr_len[j]) ==
                                LDNS_RR_TYPE_ZONEMD &&
                                query_dname_compare(z->name, node->name)==0) {
                                /* omit RRSIGs over type ZONEMD at apex */
                                continue;
                        }
                        count++;
                }
        }
        for(i=0; i<rrnum; i++) {
                if(rrlist[i] && rrlist[i]->type == LDNS_RR_TYPE_ZONEMD &&
                        query_dname_compare(z->name, node->name)==0) {
                        /* omit RRSIGs over type ZONEMD at apex */
                        continue;
                }
                count += (rrlist[i]?rrlist[i]->data->rrsig_count:0);
        }
        return count;
}

/** allocate sparse rrset data for the number of entries in tepm region */
static int zonemd_simple_rrsig_allocs(struct regional* region,
        struct packed_rrset_data* data, size_t count)
{
        data->rr_len = regional_alloc(region, sizeof(*data->rr_len) * count);
        if(!data->rr_len) {
                return 0;
        }
        data->rr_ttl = regional_alloc(region, sizeof(*data->rr_ttl) * count);
        if(!data->rr_ttl) {
                return 0;
        }
        data->rr_data = regional_alloc(region, sizeof(*data->rr_data) * count);
        if(!data->rr_data) {
                return 0;
        }
        return 1;
}

/** add the RRSIGs from the rrs in the domain into the data */
static void add_rrlist_rrsigs_into_data(struct packed_rrset_data* data,
        size_t* done, struct auth_rrset** rrlist, size_t rrnum,
        struct auth_zone* z, struct auth_data* node)
{
        size_t i;
        for(i=0; i<rrnum; i++) {
                size_t j;
                if(!rrlist[i])
                        continue;
                if(rrlist[i]->type == LDNS_RR_TYPE_ZONEMD &&
                        query_dname_compare(z->name, node->name)==0) {
                        /* omit RRSIGs over type ZONEMD at apex */
                        continue;
                }
                for(j = 0; j<rrlist[i]->data->rrsig_count; j++) {
                        data->rr_len[*done] = rrlist[i]->data->rr_len[rrlist[i]->data->count + j];
                        data->rr_ttl[*done] = rrlist[i]->data->rr_ttl[rrlist[i]->data->count + j];
                        /* reference the rdata in the rrset, no need to
                         * copy it, it is no longer needed at the end of
                         * the routine */
                        data->rr_data[*done] = rrlist[i]->data->rr_data[rrlist[i]->data->count + j];
                        (*done)++;
                }
        }
}

static void add_rrset_into_data(struct packed_rrset_data* data,
        size_t* done, struct auth_rrset* rrset,
        struct auth_zone* z, struct auth_data* node)
{
        if(rrset) {
                size_t j;
                for(j = 0; j<rrset->data->count; j++) {
                        if(rrsig_rdata_get_type_covered(rrset->data->
                                rr_data[j], rrset->data->rr_len[j]) ==
                                LDNS_RR_TYPE_ZONEMD &&
                                query_dname_compare(z->name, node->name)==0) {
                                /* omit RRSIGs over type ZONEMD at apex */
                                continue;
                        }
                        data->rr_len[*done] = rrset->data->rr_len[j];
                        data->rr_ttl[*done] = rrset->data->rr_ttl[j];
                        /* reference the rdata in the rrset, no need to
                         * copy it, it is no longer need at the end of
                         * the routine */
                        data->rr_data[*done] = rrset->data->rr_data[j];
                        (*done)++;
                }
        }
}

/** collate the RRSIGs using the simple scheme */
static int zonemd_simple_rrsig(struct auth_zone* z, int hashalgo,
        struct secalgo_hash* h, struct auth_data* node,
        struct auth_rrset* rrset, struct auth_rrset** rrlist, size_t rrnum,
        struct regional* region, struct sldns_buffer* buf, char** reason)
{
        /* the rrset pointer can be NULL, this means it is type RRSIG and
         * there is no ordinary type RRSIG there.  The RRSIGs are stored
         * with the RRsets in their data.
         *
         * The RRset pointer can be nonNULL. This happens if there is
         * no RR that is covered by the RRSIG for the domain.  Then this
         * RRSIG RR is stored in an rrset of type RRSIG. The other RRSIGs
         * are stored in the rrset entries for the RRs in the rr list for
         * the domain node.  We need to collate the rrset's data, if any, and
         * the rrlist's rrsigs */
        /* if this is the apex, omit RRSIGs that cover type ZONEMD */
        /* build rrsig rrset */
        size_t done = 0;
        struct ub_packed_rrset_key key;
        struct packed_rrset_data data;
        memset(&key, 0, sizeof(key));
        memset(&data, 0, sizeof(data));
        key.entry.key = &key;
        key.entry.data = &data;
        key.rk.dname = node->name;
        key.rk.dname_len = node->namelen;
        key.rk.type = htons(LDNS_RR_TYPE_RRSIG);
        key.rk.rrset_class = htons(z->dclass);
        data.count = zonemd_simple_count_rrsig(rrset, rrlist, rrnum, z, node);
        if(!zonemd_simple_rrsig_allocs(region, &data, data.count)) {
                *reason = "out of memory";
                regional_free_all(region);
                return 0;
        }
        /* all the RRSIGs stored in the other rrsets for this domain node */
        add_rrlist_rrsigs_into_data(&data, &done, rrlist, rrnum, z, node);
        /* plus the RRSIGs stored in an rrset of type RRSIG for this node */
        add_rrset_into_data(&data, &done, rrset, z, node);

        /* canonicalize */
        if(!rrset_canonicalize_to_buffer(region, buf, &key)) {
                *reason = "out of memory";
                regional_free_all(region);
                return 0;
        }
        regional_free_all(region);

        /* hash */
        if(!zonemd_digest_update(hashalgo, h, sldns_buffer_begin(buf),
                sldns_buffer_limit(buf), reason)) {
                return 0;
        }
        return 1;
}

/** collate a domain's rrsets using the simple scheme */
static int zonemd_simple_domain(struct auth_zone* z, int hashalgo,
        struct secalgo_hash* h, struct auth_data* node,
        struct regional* region, struct sldns_buffer* buf, char** reason)
{
        const size_t rrlistsize = 65536;
        struct auth_rrset* rrlist[rrlistsize];
        size_t i, rrnum = 0;
        /* see if the domain is out of scope, the zone origin,
         * that would be omitted */
        if(!dname_subdomain_c(node->name, z->name))
                return 1; /* continue */
        /* loop over the rrsets in ascending order. */
        rrnum = authdata_rrsets_to_list(rrlist, rrlistsize, node->rrsets);
        addrrsigtype_if_needed(rrlist, rrlistsize, &rrnum, node);
        qsort(rrlist, rrnum, sizeof(*rrlist), rrlist_compare);
        for(i=0; i<rrnum; i++) {
                if(rrlist[i] && rrlist[i]->type == LDNS_RR_TYPE_ZONEMD &&
                        query_dname_compare(z->name, node->name) == 0) {
                        /* omit type ZONEMD at apex */
                        continue;
                }
                if(rrlist[i] == NULL || rrlist[i]->type ==
                        LDNS_RR_TYPE_RRSIG) {
                        if(!zonemd_simple_rrsig(z, hashalgo, h, node,
                                rrlist[i], rrlist, rrnum, region, buf, reason))
                                return 0;
                } else if(!zonemd_simple_rrset(z, hashalgo, h, node,
                        rrlist[i], region, buf, reason)) {
                        return 0;
                }
        }
        return 1;
}

/** collate the zone using the simple scheme */
static int zonemd_simple_collate(struct auth_zone* z, int hashalgo,
        struct secalgo_hash* h, struct regional* region,
        struct sldns_buffer* buf, char** reason)
{
        /* our tree is sorted in canonical order, so we can just loop over
         * the tree */
        struct auth_data* n;
        RBTREE_FOR(n, struct auth_data*, &z->data) {
                if(!zonemd_simple_domain(z, hashalgo, h, n, region, buf,
                        reason))
                        return 0;
        }
        return 1;
}

int auth_zone_generate_zonemd_hash(struct auth_zone* z, int scheme,
        int hashalgo, uint8_t* hash, size_t hashlen, size_t* resultlen,
        struct regional* region, struct sldns_buffer* buf, char** reason)
{
        struct secalgo_hash* h = zonemd_digest_init(hashalgo, reason);
        if(!h) {
                if(!*reason)
                        *reason = "digest init fail";
                return 0;
        }
        if(scheme == ZONEMD_SCHEME_SIMPLE) {
                if(!zonemd_simple_collate(z, hashalgo, h, region, buf, reason)) {
                        if(!*reason) *reason = "scheme simple collate fail";
                        secalgo_hash_delete(h);
                        return 0;
                }
        }
        if(!zonemd_digest_finish(hashalgo, h, hash, hashlen, resultlen,
                reason)) {
                secalgo_hash_delete(h);
                *reason = "digest finish fail";
                return 0;
        }
        secalgo_hash_delete(h);
        return 1;
}

int auth_zone_generate_zonemd_check(struct auth_zone* z, int scheme,
        int hashalgo, uint8_t* hash, size_t hashlen, struct regional* region,
        struct sldns_buffer* buf, char** reason)
{
        uint8_t gen[512];
        size_t genlen = 0;
        *reason = NULL;
        if(!zonemd_hashalgo_supported(hashalgo)) {
                /* allow it */
                *reason = "unsupported algorithm";
                return 1;
        }
        if(!zonemd_scheme_supported(scheme)) {
                /* allow it */
                *reason = "unsupported scheme";
                return 1;
        }
        if(hashlen < 12) {
                /* the ZONEMD draft requires digests to fail if too small */
                *reason = "digest length too small, less than 12";
                return 0;
        }
        /* generate digest */
        if(!auth_zone_generate_zonemd_hash(z, scheme, hashalgo, gen,
                sizeof(gen), &genlen, region, buf, reason)) {
                /* reason filled in by zonemd hash routine */
                return 0;
        }
        /* check digest length */
        if(hashlen != genlen) {
                *reason = "incorrect digest length";
                if(verbosity >= VERB_ALGO) {
                        verbose(VERB_ALGO, "zonemd scheme=%d hashalgo=%d",
                                scheme, hashalgo);
                        log_hex("ZONEMD should be  ", gen, genlen);
                        log_hex("ZONEMD to check is", hash, hashlen);
                }
                return 0;
        }
        /* check digest */
        if(memcmp(hash, gen, genlen) != 0) {
                *reason = "incorrect digest";
                if(verbosity >= VERB_ALGO) {
                        verbose(VERB_ALGO, "zonemd scheme=%d hashalgo=%d",
                                scheme, hashalgo);
                        log_hex("ZONEMD should be  ", gen, genlen);
                        log_hex("ZONEMD to check is", hash, hashlen);
                }
                return 0;
        }
        return 1;
}

/** log auth zone message with zone name in front. */
static void auth_zone_log(uint8_t* name, enum verbosity_value level,
        const char* format, ...) ATTR_FORMAT(printf, 3, 4);
static void auth_zone_log(uint8_t* name, enum verbosity_value level,
        const char* format, ...)
{
        va_list args;
        va_start(args, format);
        if(verbosity >= level) {
                char str[LDNS_MAX_DOMAINLEN];
                char msg[MAXSYSLOGMSGLEN];
                dname_str(name, str);
                vsnprintf(msg, sizeof(msg), format, args);
                verbose(level, "auth zone %s %s", str, msg);
        }
        va_end(args);
}

/** ZONEMD, dnssec verify the rrset with the dnskey */
static int zonemd_dnssec_verify_rrset(struct auth_zone* z,
        struct module_env* env, struct module_stack* mods,
        struct ub_packed_rrset_key* dnskey, struct auth_data* node,
        struct auth_rrset* rrset, char** why_bogus, uint8_t* sigalg,
        char* reasonbuf, size_t reasonlen)
{
        struct ub_packed_rrset_key pk;
        enum sec_status sec;
        struct val_env* ve;
        int m;
        int verified = 0;
        m = modstack_find(mods, "validator");
        if(m == -1) {
                auth_zone_log(z->name, VERB_ALGO, "zonemd dnssec verify: have "
                        "DNSKEY chain of trust, but no validator module");
                return 0;
        }
        ve = (struct val_env*)env->modinfo[m];

        memset(&pk, 0, sizeof(pk));
        pk.entry.key = &pk;
        pk.entry.data = rrset->data;
        pk.rk.dname = node->name;
        pk.rk.dname_len = node->namelen;
        pk.rk.type = htons(rrset->type);
        pk.rk.rrset_class = htons(z->dclass);
        if(verbosity >= VERB_ALGO) {
                char typestr[32];
                typestr[0]=0;
                sldns_wire2str_type_buf(rrset->type, typestr, sizeof(typestr));
                auth_zone_log(z->name, VERB_ALGO,
                        "zonemd: verify %s RRset with DNSKEY", typestr);
        }
        sec = dnskeyset_verify_rrset(env, ve, &pk, dnskey, sigalg, why_bogus, NULL,
                LDNS_SECTION_ANSWER, NULL, &verified, reasonbuf, reasonlen);
        if(sec == sec_status_secure) {
                return 1;
        }
        if(why_bogus)
                auth_zone_log(z->name, VERB_ALGO, "DNSSEC verify was bogus: %s", *why_bogus);
        return 0;
}

/** check for nsec3, the RR with params equal, if bitmap has the type */
static int nsec3_of_param_has_type(struct auth_rrset* nsec3, int algo,
        size_t iter, uint8_t* salt, size_t saltlen, uint16_t rrtype)
{
        int i, count = (int)nsec3->data->count;
        struct ub_packed_rrset_key pk;
        memset(&pk, 0, sizeof(pk));
        pk.entry.data = nsec3->data;
        for(i=0; i<count; i++) {
                int rralgo;
                size_t rriter, rrsaltlen;
                uint8_t* rrsalt;
                if(!nsec3_get_params(&pk, i, &rralgo, &rriter, &rrsalt,
                        &rrsaltlen))
                        continue; /* no parameters, malformed */
                if(rralgo != algo || rriter != iter || rrsaltlen != saltlen)
                        continue; /* different parameters */
                if(saltlen != 0) {
                        if(rrsalt == NULL || salt == NULL)
                                continue;
                        if(memcmp(rrsalt, salt, saltlen) != 0)
                                continue; /* different salt parameters */
                }
                if(nsec3_has_type(&pk, i, rrtype))
                        return 1;
        }
        return 0;
}

/** Verify the absence of ZONEMD with DNSSEC by checking NSEC, NSEC3 type flag.
 * return false on failure, reason contains description of failure. */
static int zonemd_check_dnssec_absence(struct auth_zone* z,
        struct module_env* env, struct module_stack* mods,
        struct ub_packed_rrset_key* dnskey, struct auth_data* apex,
        char** reason, char** why_bogus, uint8_t* sigalg, char* reasonbuf,
        size_t reasonlen)
{
        struct auth_rrset* nsec = NULL;
        if(!apex) {
                *reason = "zone has no apex domain but ZONEMD missing";
                return 0;
        }
        nsec = az_domain_rrset(apex, LDNS_RR_TYPE_NSEC);
        if(nsec) {
                struct ub_packed_rrset_key pk;
                /* dnssec verify the NSEC */
                if(!zonemd_dnssec_verify_rrset(z, env, mods, dnskey, apex,
                        nsec, why_bogus, sigalg, reasonbuf, reasonlen)) {
                        *reason = "DNSSEC verify failed for NSEC RRset";
                        return 0;
                }
                /* check type bitmap */
                memset(&pk, 0, sizeof(pk));
                pk.entry.data = nsec->data;
                if(nsec_has_type(&pk, LDNS_RR_TYPE_ZONEMD)) {
                        *reason = "DNSSEC NSEC bitmap says type ZONEMD exists";
                        return 0;
                }
                auth_zone_log(z->name, VERB_ALGO, "zonemd DNSSEC NSEC verification of absence of ZONEMD secure");
        } else {
                /* NSEC3 perhaps ? */
                int algo;
                size_t iter, saltlen;
                uint8_t* salt;
                struct auth_rrset* nsec3param = az_domain_rrset(apex,
                        LDNS_RR_TYPE_NSEC3PARAM);
                struct auth_data* match;
                struct auth_rrset* nsec3;
                if(!nsec3param) {
                        *reason = "zone has no NSEC information but ZONEMD missing";
                        return 0;
                }
                if(!az_nsec3_param(z, &algo, &iter, &salt, &saltlen)) {
                        *reason = "zone has no NSEC information but ZONEMD missing";
                        return 0;
                }
                /* find the NSEC3 record */
                match = az_nsec3_find_exact(z, z->name, z->namelen, algo,
                        iter, salt, saltlen);
                if(!match) {
                        *reason = "zone has no NSEC3 domain for the apex but ZONEMD missing";
                        return 0;
                }
                nsec3 = az_domain_rrset(match, LDNS_RR_TYPE_NSEC3);
                if(!nsec3) {
                        *reason = "zone has no NSEC3 RRset for the apex but ZONEMD missing";
                        return 0;
                }
                /* dnssec verify the NSEC3 */
                if(!zonemd_dnssec_verify_rrset(z, env, mods, dnskey, match,
                        nsec3, why_bogus, sigalg, reasonbuf, reasonlen)) {
                        *reason = "DNSSEC verify failed for NSEC3 RRset";
                        return 0;
                }
                /* check type bitmap */
                if(nsec3_of_param_has_type(nsec3, algo, iter, salt, saltlen,
                        LDNS_RR_TYPE_ZONEMD)) {
                        *reason = "DNSSEC NSEC3 bitmap says type ZONEMD exists";
                        return 0;
                }
                auth_zone_log(z->name, VERB_ALGO, "zonemd DNSSEC NSEC3 verification of absence of ZONEMD secure");
        }

        return 1;
}

/** Verify the SOA and ZONEMD DNSSEC signatures.
 * return false on failure, reason contains description of failure. */
static int zonemd_check_dnssec_soazonemd(struct auth_zone* z,
        struct module_env* env, struct module_stack* mods,
        struct ub_packed_rrset_key* dnskey, struct auth_data* apex,
        struct auth_rrset* zonemd_rrset, char** reason, char** why_bogus,
        uint8_t* sigalg, char* reasonbuf, size_t reasonlen)
{
        struct auth_rrset* soa;
        if(!apex) {
                *reason = "zone has no apex domain";
                return 0;
        }
        soa = az_domain_rrset(apex, LDNS_RR_TYPE_SOA);
        if(!soa) {
                *reason = "zone has no SOA RRset";
                return 0;
        }
        if(!zonemd_dnssec_verify_rrset(z, env, mods, dnskey, apex, soa,
                why_bogus, sigalg, reasonbuf, reasonlen)) {
                *reason = "DNSSEC verify failed for SOA RRset";
                return 0;
        }
        if(!zonemd_dnssec_verify_rrset(z, env, mods, dnskey, apex,
                zonemd_rrset, why_bogus, sigalg, reasonbuf, reasonlen)) {
                *reason = "DNSSEC verify failed for ZONEMD RRset";
                return 0;
        }
        auth_zone_log(z->name, VERB_ALGO, "zonemd DNSSEC verification of SOA and ZONEMD RRsets secure");
        return 1;
}

/**
 * Fail the ZONEMD verification.
 * @param z: auth zone that fails.
 * @param env: environment with config, to ignore failure or not.
 * @param reason: failure string description.
 * @param why_bogus: failure string for DNSSEC verification failure.
 * @param result: strdup result in here if not NULL.
 */
static void auth_zone_zonemd_fail(struct auth_zone* z, struct module_env* env,
        char* reason, char* why_bogus, char** result)
{
        char zstr[LDNS_MAX_DOMAINLEN];
        /* if fail: log reason, and depending on config also take action
         * and drop the zone, eg. it is gone from memory, set zone_expired */
        dname_str(z->name, zstr);
        if(!reason) reason = "verification failed";
        if(result) {
                if(why_bogus) {
                        char res[1024];
                        snprintf(res, sizeof(res), "%s: %s", reason,
                                why_bogus);
                        *result = strdup(res);
                } else {
                        *result = strdup(reason);
                }
                if(!*result) log_err("out of memory");
        } else {
                log_warn("auth zone %s: ZONEMD verification failed: %s", zstr, reason);
        }

        if(env->cfg->zonemd_permissive_mode) {
                verbose(VERB_ALGO, "zonemd-permissive-mode enabled, "
                        "not blocking zone %s", zstr);
                return;
        }

        /* expired means the zone gives servfail and is not used by
         * lookup if fallback_enabled*/
        z->zone_expired = 1;
}

/**
 * Verify the zonemd with DNSSEC and hash check, with given key.
 * @param z: auth zone.
 * @param env: environment with config and temp buffers.
 * @param mods: module stack with validator env for verification.
 * @param dnskey: dnskey that we can use, or NULL.  If nonnull, the key
 *      has been verified and is the start of the chain of trust.
 * @param is_insecure: if true, the dnskey is not used, the zone is insecure.
 *      And dnssec is not used.  It is DNSSEC secure insecure or not under
 *      a trust anchor.
 * @param sigalg: if nonNULL provide algorithm downgrade protection.
 *      Otherwise one algorithm is enough. Must have space of ALGO_NEEDS_MAX+1.
 * @param result: if not NULL result reason copied here.
 */
static void
auth_zone_verify_zonemd_with_key(struct auth_zone* z, struct module_env* env,
        struct module_stack* mods, struct ub_packed_rrset_key* dnskey,
        int is_insecure, char** result, uint8_t* sigalg)
{
        char reasonbuf[256];
        char* reason = NULL, *why_bogus = NULL;
        struct auth_data* apex = NULL;
        struct auth_rrset* zonemd_rrset = NULL;
        int zonemd_absent = 0, zonemd_absence_dnssecok = 0;

        /* see if ZONEMD is present or absent. */
        apex = az_find_name(z, z->name, z->namelen);
        if(!apex) {
                zonemd_absent = 1;
        } else {
                zonemd_rrset = az_domain_rrset(apex, LDNS_RR_TYPE_ZONEMD);
                if(!zonemd_rrset || zonemd_rrset->data->count==0) {
                        zonemd_absent = 1;
                        zonemd_rrset = NULL;
                }
        }

        /* if no DNSSEC, done. */
        /* if no ZONEMD, and DNSSEC, use DNSKEY to verify NSEC or NSEC3 for
         * zone apex.  Check ZONEMD bit is turned off or else fail */
        /* if ZONEMD, and DNSSEC, check DNSSEC signature on SOA and ZONEMD,
         * or else fail */
        if(!dnskey && !is_insecure) {
                auth_zone_zonemd_fail(z, env, "DNSKEY missing", NULL, result);
                return;
        } else if(!zonemd_rrset && dnskey && !is_insecure) {
                /* fetch, DNSSEC verify, and check NSEC/NSEC3 */
                if(!zonemd_check_dnssec_absence(z, env, mods, dnskey, apex,
                        &reason, &why_bogus, sigalg, reasonbuf,
                        sizeof(reasonbuf))) {
                        auth_zone_zonemd_fail(z, env, reason, why_bogus, result);
                        return;
                }
                zonemd_absence_dnssecok = 1;
        } else if(zonemd_rrset && dnskey && !is_insecure) {
                /* check DNSSEC verify of SOA and ZONEMD */
                if(!zonemd_check_dnssec_soazonemd(z, env, mods, dnskey, apex,
                        zonemd_rrset, &reason, &why_bogus, sigalg, reasonbuf,
                        sizeof(reasonbuf))) {
                        auth_zone_zonemd_fail(z, env, reason, why_bogus, result);
                        return;
                }
        }

        if(zonemd_absent && z->zonemd_reject_absence) {
                auth_zone_zonemd_fail(z, env, "ZONEMD absent and that is not allowed by config", NULL, result);
                return;
        }
        if(zonemd_absent && zonemd_absence_dnssecok) {
                auth_zone_log(z->name, VERB_ALGO, "DNSSEC verified nonexistence of ZONEMD");
                if(result) {
                        *result = strdup("DNSSEC verified nonexistence of ZONEMD");
                        if(!*result) log_err("out of memory");
                }
                return;
        }
        if(zonemd_absent) {
                auth_zone_log(z->name, VERB_ALGO, "no ZONEMD present");
                if(result) {
                        *result = strdup("no ZONEMD present");
                        if(!*result) log_err("out of memory");
                }
                return;
        }

        /* check ZONEMD checksum and report or else fail. */
        if(!auth_zone_zonemd_check_hash(z, env, &reason)) {
                auth_zone_zonemd_fail(z, env, reason, NULL, result);
                return;
        }

        /* success! log the success */
        if(reason)
                auth_zone_log(z->name, VERB_ALGO, "ZONEMD %s", reason);
        else    auth_zone_log(z->name, VERB_ALGO, "ZONEMD verification successful");
        if(result) {
                if(reason)
                        *result = strdup(reason);
                else    *result = strdup("ZONEMD verification successful");
                if(!*result) log_err("out of memory");
        }
}

/**
 * verify the zone DNSKEY rrset from the trust anchor
 * This is possible because the anchor is for the zone itself, and can
 * thus apply straight to the zone DNSKEY set.
 * @param z: the auth zone.
 * @param env: environment with time and temp buffers.
 * @param mods: module stack for validator environment for dnssec validation.
 * @param anchor: trust anchor to use
 * @param is_insecure: returned, true if the zone is securely insecure.
 * @param why_bogus: if the routine fails, returns the failure reason.
 * @param keystorage: where to store the ub_packed_rrset_key that is created
 *      on success. A pointer to it is returned on success.
 * @param reasonbuf: buffer to use for fail reason string print.
 * @param reasonlen: length of reasonbuf.
 * @return the dnskey RRset, reference to zone data and keystorage, or
 *      NULL on failure.
 */
static struct ub_packed_rrset_key*
zonemd_get_dnskey_from_anchor(struct auth_zone* z, struct module_env* env,
        struct module_stack* mods, struct trust_anchor* anchor,
        int* is_insecure, char** why_bogus,
        struct ub_packed_rrset_key* keystorage, char* reasonbuf,
        size_t reasonlen)
{
        struct auth_data* apex;
        struct auth_rrset* dnskey_rrset;
        enum sec_status sec;
        struct val_env* ve;
        int m;

        apex = az_find_name(z, z->name, z->namelen);
        if(!apex) {
                *why_bogus = "have trust anchor, but zone has no apex domain for DNSKEY";
                return 0;
        }
        dnskey_rrset = az_domain_rrset(apex, LDNS_RR_TYPE_DNSKEY);
        if(!dnskey_rrset || dnskey_rrset->data->count==0) {
                *why_bogus = "have trust anchor, but zone has no DNSKEY";
                return 0;
        }

        m = modstack_find(mods, "validator");
        if(m == -1) {
                *why_bogus = "have trust anchor, but no validator module";
                return 0;
        }
        ve = (struct val_env*)env->modinfo[m];

        memset(keystorage, 0, sizeof(*keystorage));
        keystorage->entry.key = keystorage;
        keystorage->entry.data = dnskey_rrset->data;
        keystorage->rk.dname = apex->name;
        keystorage->rk.dname_len = apex->namelen;
        keystorage->rk.type = htons(LDNS_RR_TYPE_DNSKEY);
        keystorage->rk.rrset_class = htons(z->dclass);
        auth_zone_log(z->name, VERB_QUERY,
                "zonemd: verify DNSKEY RRset with trust anchor");
        sec = val_verify_DNSKEY_with_TA(env, ve, keystorage, anchor->ds_rrset,
                anchor->dnskey_rrset, NULL, why_bogus, NULL, NULL, reasonbuf,
                reasonlen);
        regional_free_all(env->scratch);
        if(sec == sec_status_secure) {
                /* success */
                *is_insecure = 0;
                return keystorage;
        } else if(sec == sec_status_insecure) {
                /* insecure */
                *is_insecure = 1;
        } else {
                /* bogus */
                *is_insecure = 0;
                auth_zone_log(z->name, VERB_ALGO,
                        "zonemd: verify DNSKEY RRset with trust anchor failed: %s", *why_bogus);
        }
        return NULL;
}

/** verify the DNSKEY from the zone with looked up DS record */
static struct ub_packed_rrset_key*
auth_zone_verify_zonemd_key_with_ds(struct auth_zone* z,
        struct module_env* env, struct module_stack* mods,
        struct ub_packed_rrset_key* ds, int* is_insecure, char** why_bogus,
        struct ub_packed_rrset_key* keystorage, uint8_t* sigalg,
        char* reasonbuf, size_t reasonlen)
{
        struct auth_data* apex;
        struct auth_rrset* dnskey_rrset;
        enum sec_status sec;
        struct val_env* ve;
        int m;

        /* fetch DNSKEY from zone data */
        apex = az_find_name(z, z->name, z->namelen);
        if(!apex) {
                *why_bogus = "in verifywithDS, zone has no apex";
                return NULL;
        }
        dnskey_rrset = az_domain_rrset(apex, LDNS_RR_TYPE_DNSKEY);
        if(!dnskey_rrset || dnskey_rrset->data->count==0) {
                *why_bogus = "in verifywithDS, zone has no DNSKEY";
                return NULL;
        }

        m = modstack_find(mods, "validator");
        if(m == -1) {
                *why_bogus = "in verifywithDS, have no validator module";
                return NULL;
        }
        ve = (struct val_env*)env->modinfo[m];

        memset(keystorage, 0, sizeof(*keystorage));
        keystorage->entry.key = keystorage;
        keystorage->entry.data = dnskey_rrset->data;
        keystorage->rk.dname = apex->name;
        keystorage->rk.dname_len = apex->namelen;
        keystorage->rk.type = htons(LDNS_RR_TYPE_DNSKEY);
        keystorage->rk.rrset_class = htons(z->dclass);
        auth_zone_log(z->name, VERB_QUERY, "zonemd: verify zone DNSKEY with DS");
        sec = val_verify_DNSKEY_with_DS(env, ve, keystorage, ds, sigalg,
                why_bogus, NULL, NULL, reasonbuf, reasonlen);
        regional_free_all(env->scratch);
        if(sec == sec_status_secure) {
                /* success */
                return keystorage;
        } else if(sec == sec_status_insecure) {
                /* insecure */
                *is_insecure = 1;
        } else {
                /* bogus */
                *is_insecure = 0;
                if(*why_bogus == NULL)
                        *why_bogus = "verify failed";
                auth_zone_log(z->name, VERB_ALGO,
                        "zonemd: verify DNSKEY RRset with DS failed: %s",
                        *why_bogus);
        }
        return NULL;
}

/** callback for ZONEMD lookup of DNSKEY */
void auth_zonemd_dnskey_lookup_callback(void* arg, int rcode, sldns_buffer* buf,
        enum sec_status sec, char* why_bogus, int ATTR_UNUSED(was_ratelimited))
{
        struct auth_zone* z = (struct auth_zone*)arg;
        struct module_env* env;
        char reasonbuf[256];
        char* reason = NULL, *ds_bogus = NULL, *typestr="DNSKEY";
        struct ub_packed_rrset_key* dnskey = NULL, *ds = NULL;
        int is_insecure = 0, downprot;
        struct ub_packed_rrset_key keystorage;
        uint8_t sigalg[ALGO_NEEDS_MAX+1];

        lock_rw_wrlock(&z->lock);
        env = z->zonemd_callback_env;
        /* release the env variable so another worker can pick up the
         * ZONEMD verification task if it wants to */
        z->zonemd_callback_env = NULL;
        if(!env || env->outnet->want_to_quit || z->zone_deleted) {
                lock_rw_unlock(&z->lock);
                return; /* stop on quit */
        }
        if(z->zonemd_callback_qtype == LDNS_RR_TYPE_DS)
                typestr = "DS";
        downprot = env->cfg->harden_algo_downgrade;

        /* process result */
        if(sec == sec_status_bogus) {
                reason = why_bogus;
                if(!reason) {
                        if(z->zonemd_callback_qtype == LDNS_RR_TYPE_DNSKEY)
                                reason = "lookup of DNSKEY was bogus";
                        else    reason = "lookup of DS was bogus";
                }
                auth_zone_log(z->name, VERB_ALGO,
                        "zonemd lookup of %s was bogus: %s", typestr, reason);
        } else if(rcode == LDNS_RCODE_NOERROR) {
                uint16_t wanted_qtype = z->zonemd_callback_qtype;
                struct regional* temp = env->scratch;
                struct query_info rq;
                struct reply_info* rep;
                memset(&rq, 0, sizeof(rq));
                rep = parse_reply_in_temp_region(buf, temp, &rq);
                if(rep && rq.qtype == wanted_qtype &&
                        query_dname_compare(z->name, rq.qname) == 0 &&
                        FLAGS_GET_RCODE(rep->flags) == LDNS_RCODE_NOERROR) {
                        /* parsed successfully */
                        struct ub_packed_rrset_key* answer =
                                reply_find_answer_rrset(&rq, rep);
                        if(answer && sec == sec_status_secure) {
                                if(z->zonemd_callback_qtype == LDNS_RR_TYPE_DNSKEY)
                                        dnskey = answer;
                                else    ds = answer;
                                auth_zone_log(z->name, VERB_ALGO,
                                        "zonemd lookup of %s was secure", typestr);
                        } else if(sec == sec_status_secure && !answer) {
                                is_insecure = 1;
                                auth_zone_log(z->name, VERB_ALGO,
                                        "zonemd lookup of %s has no content, but is secure, treat as insecure", typestr);
                        } else if(sec == sec_status_insecure) {
                                is_insecure = 1;
                                auth_zone_log(z->name, VERB_ALGO,
                                        "zonemd lookup of %s was insecure", typestr);
                        } else if(sec == sec_status_indeterminate) {
                                is_insecure = 1;
                                auth_zone_log(z->name, VERB_ALGO,
                                        "zonemd lookup of %s was indeterminate, treat as insecure", typestr);
                        } else {
                                auth_zone_log(z->name, VERB_ALGO,
                                        "zonemd lookup of %s has nodata", typestr);
                                if(z->zonemd_callback_qtype == LDNS_RR_TYPE_DNSKEY)
                                        reason = "lookup of DNSKEY has nodata";
                                else    reason = "lookup of DS has nodata";
                        }
                } else if(rep && rq.qtype == wanted_qtype &&
                        query_dname_compare(z->name, rq.qname) == 0 &&
                        FLAGS_GET_RCODE(rep->flags) == LDNS_RCODE_NXDOMAIN &&
                        sec == sec_status_secure) {
                        /* secure nxdomain, so the zone is like some RPZ zone
                         * that does not exist in the wider internet, with
                         * a secure nxdomain answer outside of it. So we
                         * treat the zonemd zone without a dnssec chain of
                         * trust, as insecure. */
                        is_insecure = 1;
                        auth_zone_log(z->name, VERB_ALGO,
                                "zonemd lookup of %s was secure NXDOMAIN, treat as insecure", typestr);
                } else if(rep && rq.qtype == wanted_qtype &&
                        query_dname_compare(z->name, rq.qname) == 0 &&
                        FLAGS_GET_RCODE(rep->flags) == LDNS_RCODE_NXDOMAIN &&
                        sec == sec_status_insecure) {
                        is_insecure = 1;
                        auth_zone_log(z->name, VERB_ALGO,
                                "zonemd lookup of %s was insecure NXDOMAIN, treat as insecure", typestr);
                } else if(rep && rq.qtype == wanted_qtype &&
                        query_dname_compare(z->name, rq.qname) == 0 &&
                        FLAGS_GET_RCODE(rep->flags) == LDNS_RCODE_NXDOMAIN &&
                        sec == sec_status_indeterminate) {
                        is_insecure = 1;
                        auth_zone_log(z->name, VERB_ALGO,
                                "zonemd lookup of %s was indeterminate NXDOMAIN, treat as insecure", typestr);
                } else {
                        auth_zone_log(z->name, VERB_ALGO,
                                "zonemd lookup of %s has no answer", typestr);
                        if(z->zonemd_callback_qtype == LDNS_RR_TYPE_DNSKEY)
                                reason = "lookup of DNSKEY has no answer";
                        else    reason = "lookup of DS has no answer";
                }
        } else {
                auth_zone_log(z->name, VERB_ALGO,
                        "zonemd lookup of %s failed", typestr);
                if(z->zonemd_callback_qtype == LDNS_RR_TYPE_DNSKEY)
                        reason = "lookup of DNSKEY failed";
                else    reason = "lookup of DS failed";
        }

        if(!reason && !is_insecure && !dnskey && ds) {
                dnskey = auth_zone_verify_zonemd_key_with_ds(z, env,
                        &env->mesh->mods, ds, &is_insecure, &ds_bogus,
                        &keystorage, downprot?sigalg:NULL, reasonbuf,
                        sizeof(reasonbuf));
                if(!dnskey && !is_insecure && !reason)
                        reason = "DNSKEY verify with DS failed";
        }

        if(reason) {
                auth_zone_zonemd_fail(z, env, reason, ds_bogus, NULL);
                lock_rw_unlock(&z->lock);
                regional_free_all(env->scratch);
                return;
        }

        auth_zone_verify_zonemd_with_key(z, env, &env->mesh->mods, dnskey,
                is_insecure, NULL, downprot?sigalg:NULL);
        regional_free_all(env->scratch);
        lock_rw_unlock(&z->lock);
}

/** lookup DNSKEY for ZONEMD verification */
static int
zonemd_lookup_dnskey(struct auth_zone* z, struct module_env* env)
{
        struct query_info qinfo;
        uint16_t qflags = BIT_RD;
        struct edns_data edns;
        sldns_buffer* buf = env->scratch_buffer;
        int fetch_ds = 0;

        if(!z->fallback_enabled) {
                /* we cannot actually get the DNSKEY, because it is in the
                 * zone we have ourselves, and it is not served yet
                 * (possibly), so fetch type DS */
                fetch_ds = 1;
        }
        if(z->zonemd_callback_env) {
                /* another worker is already working on the callback
                 * for the DNSKEY lookup for ZONEMD verification.
                 * We do not also have to do ZONEMD verification, let that
                 * worker do it */
                auth_zone_log(z->name, VERB_ALGO,
                        "zonemd needs lookup of %s and that already is worked on by another worker", (fetch_ds?"DS":"DNSKEY"));
                return 1;
        }

        /* use mesh_new_callback to lookup the DNSKEY,
         * and then wait for them to be looked up (in cache, or query) */
        qinfo.qname_len = z->namelen;
        qinfo.qname = z->name;
        qinfo.qclass = z->dclass;
        if(fetch_ds)
                qinfo.qtype = LDNS_RR_TYPE_DS;
        else    qinfo.qtype = LDNS_RR_TYPE_DNSKEY;
        qinfo.local_alias = NULL;
        if(verbosity >= VERB_ALGO) {
                char buf1[512];
                char buf2[LDNS_MAX_DOMAINLEN];
                dname_str(z->name, buf2);
                snprintf(buf1, sizeof(buf1), "auth zone %s: lookup %s "
                        "for zonemd verification", buf2,
                        (fetch_ds?"DS":"DNSKEY"));
                log_query_info(VERB_ALGO, buf1, &qinfo);
        }
        edns.edns_present = 1;
        edns.ext_rcode = 0;
        edns.edns_version = 0;
        edns.bits = EDNS_DO;
        edns.opt_list_in = NULL;
        edns.opt_list_out = NULL;
        edns.opt_list_inplace_cb_out = NULL;
        if(sldns_buffer_capacity(buf) < 65535)
                edns.udp_size = (uint16_t)sldns_buffer_capacity(buf);
        else    edns.udp_size = 65535;

        /* store the worker-specific module env for the callback.
         * We can then reference this when the callback executes */
        z->zonemd_callback_env = env;
        z->zonemd_callback_qtype = qinfo.qtype;
        /* the callback can be called straight away */
        lock_rw_unlock(&z->lock);
        if(!mesh_new_callback(env->mesh, &qinfo, qflags, &edns, buf, 0,
                &auth_zonemd_dnskey_lookup_callback, z, 0)) {
                lock_rw_wrlock(&z->lock);
                log_err("out of memory lookup of %s for zonemd",
                        (fetch_ds?"DS":"DNSKEY"));
                return 0;
        }
        lock_rw_wrlock(&z->lock);
        return 1;
}

void auth_zone_verify_zonemd(struct auth_zone* z, struct module_env* env,
        struct module_stack* mods, char** result, int offline, int only_online)
{
        char reasonbuf[256];
        char* reason = NULL, *why_bogus = NULL;
        struct trust_anchor* anchor = NULL;
        struct ub_packed_rrset_key* dnskey = NULL;
        struct ub_packed_rrset_key keystorage;
        int is_insecure = 0;
        /* verify the ZONEMD if present.
         * If not present check if absence is allowed by DNSSEC */
        if(!z->zonemd_check)
                return;
        if(z->data.count == 0)
                return; /* no data */

        /* if zone is under a trustanchor */
        /* is it equal to trustanchor - get dnskey's verified */
        /* else, find chain of trust by fetching DNSKEYs lookup for zone */
        /* result if that, if insecure, means no DNSSEC for the ZONEMD,
         * otherwise we have the zone DNSKEY for the DNSSEC verification. */
        if(env->anchors)
                anchor = anchors_lookup(env->anchors, z->name, z->namelen,
                        z->dclass);
        if(anchor && anchor->numDS == 0 && anchor->numDNSKEY == 0) {
                /* domain-insecure trust anchor for unsigned zones */
                lock_basic_unlock(&anchor->lock);
                if(only_online)
                        return;
                dnskey = NULL;
                is_insecure = 1;
        } else if(anchor && query_dname_compare(z->name, anchor->name) == 0) {
                if(only_online) {
                        lock_basic_unlock(&anchor->lock);
                        return;
                }
                /* equal to trustanchor, no need for online lookups */
                dnskey = zonemd_get_dnskey_from_anchor(z, env, mods, anchor,
                        &is_insecure, &why_bogus, &keystorage, reasonbuf,
                        sizeof(reasonbuf));
                lock_basic_unlock(&anchor->lock);
                if(!dnskey && !reason && !is_insecure) {
                        reason = "verify DNSKEY RRset with trust anchor failed";
                }
        } else if(anchor) {
                lock_basic_unlock(&anchor->lock);
                /* perform online lookups */
                if(offline)
                        return;
                /* setup online lookups, and wait for them */
                if(zonemd_lookup_dnskey(z, env)) {
                        /* wait for the lookup */
                        return;
                }
                reason = "could not lookup DNSKEY for chain of trust";
        } else {
                /* the zone is not under a trust anchor */
                if(only_online)
                        return;
                dnskey = NULL;
                is_insecure = 1;
        }

        if(reason) {
                auth_zone_zonemd_fail(z, env, reason, why_bogus, result);
                regional_free_all(env->scratch);
                return;
        }

        auth_zone_verify_zonemd_with_key(z, env, mods, dnskey, is_insecure,
                result, NULL);
        regional_free_all(env->scratch);
}

void auth_zones_pickup_zonemd_verify(struct auth_zones* az,
        struct module_env* env)
{
        struct auth_zone key;
        uint8_t savezname[255+1];
        size_t savezname_len;
        struct auth_zone* z;
        key.node.key = &key;
        lock_rw_rdlock(&az->lock);
        RBTREE_FOR(z, struct auth_zone*, &az->ztree) {
                lock_rw_wrlock(&z->lock);
                if(!z->zonemd_check) {
                        lock_rw_unlock(&z->lock);
                        continue;
                }
                key.dclass = z->dclass;
                key.namelabs = z->namelabs;
                if(z->namelen > sizeof(savezname)) {
                        lock_rw_unlock(&z->lock);
                        log_err("auth_zones_pickup_zonemd_verify: zone name too long");
                        continue;
                }
                savezname_len = z->namelen;
                memmove(savezname, z->name, z->namelen);
                lock_rw_unlock(&az->lock);
                auth_zone_verify_zonemd(z, env, &env->mesh->mods, NULL, 0, 1);
                lock_rw_unlock(&z->lock);
                lock_rw_rdlock(&az->lock);
                /* find the zone we had before, it is not deleted,
                 * because we have a flag for that that is processed at
                 * apply_cfg time */
                key.namelen = savezname_len;
                key.name = savezname;
                z = (struct auth_zone*)rbtree_search(&az->ztree, &key);
                if(!z)
                        break;
        }
        lock_rw_unlock(&az->lock);
}