1 files changed, 783 insertions, 0 deletions
diff --git a/3rdParty/Unbound/src/src/services/cache/dns.c b/3rdParty/Unbound/src/src/services/cache/dns.c
new file mode 100644
index 0000000..49234ab
--- /dev/null
+++ b/3rdParty/Unbound/src/src/services/cache/dns.c
@@ -0,0 +1,783 @@
+/*
+ * services/cache/dns.c - Cache services for DNS using msg and rrset caches.
+ *
+ * Copyright (c) 2007, 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 REGENTS 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 DNS cache.
+ */
+#include "config.h"
+#include "iterator/iter_delegpt.h"
+#include "validator/val_nsec.h"
+#include "services/cache/dns.h"
+#include "services/cache/rrset.h"
+#include "util/data/msgreply.h"
+#include "util/data/packed_rrset.h"
+#include "util/data/dname.h"
+#include "util/module.h"
+#include "util/net_help.h"
+#include "util/regional.h"
+#include "util/config_file.h"
+
+/** store rrsets in the rrset cache. 
+ * @param env: module environment with caches.
+ * @param rep: contains list of rrsets to store.
+ * @param now: current time.
+ * @param qrep: update rrsets here if cache is better
+ * @param region: for qrep allocs.
+ */
+static void
+store_rrsets(struct module_env* env, struct reply_info* rep, uint32_t now,
+	struct reply_info* qrep, struct regional* region)
+{
+        size_t i;
+        /* see if rrset already exists in cache, if not insert it. */
+        for(i=0; i<rep->rrset_count; i++) {
+                rep->ref[i].key = rep->rrsets[i];
+                rep->ref[i].id = rep->rrsets[i]->id;
+		/* update ref if it was in the cache */ 
+		switch(rrset_cache_update(env->rrset_cache, &rep->ref[i],
+                        env->alloc, now)) {
+		case 0: /* ref unchanged, item inserted */
+			break;
+		case 2: /* ref updated, cache is superior */
+			if(region) {
+				struct ub_packed_rrset_key* ck;
+				lock_rw_rdlock(&rep->ref[i].key->entry.lock);
+				/* if deleted rrset, do not copy it */
+				if(rep->ref[i].key->id == 0)
+					ck = NULL;
+				else 	ck = packed_rrset_copy_region(
+					rep->ref[i].key, region, now);
+				lock_rw_unlock(&rep->ref[i].key->entry.lock);
+				if(ck) {
+					/* use cached copy if memory allows */
+					qrep->rrsets[i] = ck;
+				}
+			}
+			/* no break: also copy key item */
+		case 1: /* ref updated, item inserted */
+                        rep->rrsets[i] = rep->ref[i].key;
+		}
+        }
+}
+
+void 
+dns_cache_store_msg(struct module_env* env, struct query_info* qinfo,
+	hashvalue_t hash, struct reply_info* rep, uint32_t leeway,
+	struct reply_info* qrep, struct regional* region)
+{
+	struct msgreply_entry* e;
+	uint32_t ttl = rep->ttl;
+	size_t i;
+
+	/* store RRsets */
+        for(i=0; i<rep->rrset_count; i++) {
+		rep->ref[i].key = rep->rrsets[i];
+		rep->ref[i].id = rep->rrsets[i]->id;
+	}
+
+	/* there was a reply_info_sortref(rep) here but it seems to be
+	 * unnecessary, because the cache gets locked per rrset. */
+	reply_info_set_ttls(rep, *env->now);
+	store_rrsets(env, rep, *env->now+leeway, qrep, region);
+	if(ttl == 0) {
+		/* we do not store the message, but we did store the RRs,
+		 * which could be useful for delegation information */
+		verbose(VERB_ALGO, "TTL 0: dropped msg from cache");
+		free(rep);
+		return;
+	}
+
+	/* store msg in the cache */
+	reply_info_sortref(rep);
+	if(!(e = query_info_entrysetup(qinfo, rep, hash))) {
+		log_err("store_msg: malloc failed");
+		return;
+	}
+	slabhash_insert(env->msg_cache, hash, &e->entry, rep, env->alloc);
+}
+
+/** find closest NS or DNAME and returns the rrset (locked) */
+static struct ub_packed_rrset_key*
+find_closest_of_type(struct module_env* env, uint8_t* qname, size_t qnamelen, 
+	uint16_t qclass, uint32_t now, uint16_t searchtype, int stripfront)
+{
+	struct ub_packed_rrset_key *rrset;
+	uint8_t lablen;
+
+	if(stripfront) {
+		/* strip off so that DNAMEs have strict subdomain match */
+		lablen = *qname;
+		qname += lablen + 1;
+		qnamelen -= lablen + 1;
+	}
+
+	/* snip off front part of qname until the type is found */
+	while(qnamelen > 0) {
+		if((rrset = rrset_cache_lookup(env->rrset_cache, qname, 
+			qnamelen, searchtype, qclass, 0, now, 0)))
+			return rrset;
+
+		/* snip off front label */
+		lablen = *qname;
+		qname += lablen + 1;
+		qnamelen -= lablen + 1;
+	}
+	return NULL;
+}
+
+/** add addr to additional section */
+static void
+addr_to_additional(struct ub_packed_rrset_key* rrset, struct regional* region,
+	struct dns_msg* msg, uint32_t now)
+{
+	if((msg->rep->rrsets[msg->rep->rrset_count] = 
+		packed_rrset_copy_region(rrset, region, now))) {
+		msg->rep->ar_numrrsets++;
+		msg->rep->rrset_count++;
+	}
+}
+
+/** lookup message in message cache */
+static struct msgreply_entry* 
+msg_cache_lookup(struct module_env* env, uint8_t* qname, size_t qnamelen, 
+	uint16_t qtype, uint16_t qclass, uint32_t now, int wr)
+{
+	struct lruhash_entry* e;
+	struct query_info k;
+	hashvalue_t h;
+
+	k.qname = qname;
+	k.qname_len = qnamelen;
+	k.qtype = qtype;
+	k.qclass = qclass;
+	h = query_info_hash(&k);
+	e = slabhash_lookup(env->msg_cache, h, &k, wr);
+
+	if(!e) return NULL;
+	if( now > ((struct reply_info*)e->data)->ttl ) {
+		lock_rw_unlock(&e->lock);
+		return NULL;
+	}
+	return (struct msgreply_entry*)e->key;
+}
+
+/** find and add A and AAAA records for nameservers in delegpt */
+static int
+find_add_addrs(struct module_env* env, uint16_t qclass, 
+	struct regional* region, struct delegpt* dp, uint32_t now, 
+	struct dns_msg** msg)
+{
+	struct delegpt_ns* ns;
+	struct msgreply_entry* neg;
+	struct ub_packed_rrset_key* akey;
+	for(ns = dp->nslist; ns; ns = ns->next) {
+		akey = rrset_cache_lookup(env->rrset_cache, ns->name, 
+			ns->namelen, LDNS_RR_TYPE_A, qclass, 0, now, 0);
+		if(akey) {
+			if(!delegpt_add_rrset_A(dp, region, akey, 0)) {
+				lock_rw_unlock(&akey->entry.lock);
+				return 0;
+			}
+			if(msg)
+				addr_to_additional(akey, region, *msg, now);
+			lock_rw_unlock(&akey->entry.lock);
+		} else {
+			neg = msg_cache_lookup(env, ns->name, ns->namelen,
+				LDNS_RR_TYPE_A, qclass, now, 0);
+			if(neg) {
+				delegpt_add_neg_msg(dp, neg);
+				lock_rw_unlock(&neg->entry.lock);
+			}
+		}
+		akey = rrset_cache_lookup(env->rrset_cache, ns->name, 
+			ns->namelen, LDNS_RR_TYPE_AAAA, qclass, 0, now, 0);
+		if(akey) {
+			if(!delegpt_add_rrset_AAAA(dp, region, akey, 0)) {
+				lock_rw_unlock(&akey->entry.lock);
+				return 0;
+			}
+			if(msg)
+				addr_to_additional(akey, region, *msg, now);
+			lock_rw_unlock(&akey->entry.lock);
+		} else {
+			neg = msg_cache_lookup(env, ns->name, ns->namelen,
+				LDNS_RR_TYPE_AAAA, qclass, now, 0);
+			if(neg) {
+				delegpt_add_neg_msg(dp, neg);
+				lock_rw_unlock(&neg->entry.lock);
+			}
+		}
+	}
+	return 1;
+}
+
+/** find and add A and AAAA records for missing nameservers in delegpt */
+int
+cache_fill_missing(struct module_env* env, uint16_t qclass, 
+	struct regional* region, struct delegpt* dp)
+{
+	struct delegpt_ns* ns;
+	struct msgreply_entry* neg;
+	struct ub_packed_rrset_key* akey;
+	uint32_t now = *env->now;
+	for(ns = dp->nslist; ns; ns = ns->next) {
+		akey = rrset_cache_lookup(env->rrset_cache, ns->name, 
+			ns->namelen, LDNS_RR_TYPE_A, qclass, 0, now, 0);
+		if(akey) {
+			if(!delegpt_add_rrset_A(dp, region, akey, (int)ns->lame)) {
+				lock_rw_unlock(&akey->entry.lock);
+				return 0;
+			}
+			log_nametypeclass(VERB_ALGO, "found in cache",
+				ns->name, LDNS_RR_TYPE_A, qclass);
+			lock_rw_unlock(&akey->entry.lock);
+		} else {
+			neg = msg_cache_lookup(env, ns->name, ns->namelen,
+				LDNS_RR_TYPE_A, qclass, now, 0);
+			if(neg) {
+				delegpt_add_neg_msg(dp, neg);
+				lock_rw_unlock(&neg->entry.lock);
+			}
+		}
+		akey = rrset_cache_lookup(env->rrset_cache, ns->name, 
+			ns->namelen, LDNS_RR_TYPE_AAAA, qclass, 0, now, 0);
+		if(akey) {
+			if(!delegpt_add_rrset_AAAA(dp, region, akey, (int)ns->lame)) {
+				lock_rw_unlock(&akey->entry.lock);
+				return 0;
+			}
+			log_nametypeclass(VERB_ALGO, "found in cache",
+				ns->name, LDNS_RR_TYPE_AAAA, qclass);
+			lock_rw_unlock(&akey->entry.lock);
+		} else {
+			neg = msg_cache_lookup(env, ns->name, ns->namelen,
+				LDNS_RR_TYPE_AAAA, qclass, now, 0);
+			if(neg) {
+				delegpt_add_neg_msg(dp, neg);
+				lock_rw_unlock(&neg->entry.lock);
+			}
+		}
+	}
+	return 1;
+}
+
+/** find and add DS or NSEC to delegation msg */
+static void
+find_add_ds(struct module_env* env, struct regional* region, 
+	struct dns_msg* msg, struct delegpt* dp, uint32_t now)
+{
+	/* Lookup the DS or NSEC at the delegation point. */
+	struct ub_packed_rrset_key* rrset = rrset_cache_lookup(
+		env->rrset_cache, dp->name, dp->namelen, LDNS_RR_TYPE_DS, 
+		msg->qinfo.qclass, 0, now, 0);
+	if(!rrset) {
+		/* NOTE: this won't work for alternate NSEC schemes 
+		 *	(opt-in, NSEC3) */
+		rrset = rrset_cache_lookup(env->rrset_cache, dp->name, 
+			dp->namelen, LDNS_RR_TYPE_NSEC, msg->qinfo.qclass, 
+			0, now, 0);
+		/* Note: the PACKED_RRSET_NSEC_AT_APEX flag is not used.
+		 * since this is a referral, we need the NSEC at the parent
+		 * side of the zone cut, not the NSEC at apex side. */
+		if(rrset && nsec_has_type(rrset, LDNS_RR_TYPE_DS)) {
+			lock_rw_unlock(&rrset->entry.lock);
+			rrset = NULL; /* discard wrong NSEC */
+		}
+	}
+	if(rrset) {
+		/* add it to auth section. This is the second rrset. */
+		if((msg->rep->rrsets[msg->rep->rrset_count] = 
+			packed_rrset_copy_region(rrset, region, now))) {
+			msg->rep->ns_numrrsets++;
+			msg->rep->rrset_count++;
+		}
+		lock_rw_unlock(&rrset->entry.lock);
+	}
+}
+
+struct dns_msg*
+dns_msg_create(uint8_t* qname, size_t qnamelen, uint16_t qtype, 
+	uint16_t qclass, struct regional* region, size_t capacity)
+{
+	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, qname, qnamelen);
+	if(!msg->qinfo.qname)
+		return NULL;
+	msg->qinfo.qname_len = qnamelen;
+	msg->qinfo.qtype = qtype;
+	msg->qinfo.qclass = qclass;
+	/* 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 = BIT_QR; /* with QR, no AA */
+	msg->rep->qdcount = 1;
+	msg->rep->rrsets = (struct ub_packed_rrset_key**)
+		regional_alloc(region, 
+		capacity*sizeof(struct ub_packed_rrset_key*));
+	if(!msg->rep->rrsets)
+		return NULL;
+	return msg;
+}
+
+int
+dns_msg_authadd(struct dns_msg* msg, struct regional* region, 
+	struct ub_packed_rrset_key* rrset, uint32_t now)
+{
+	if(!(msg->rep->rrsets[msg->rep->rrset_count++] = 
+		packed_rrset_copy_region(rrset, region, now)))
+		return 0;
+	msg->rep->ns_numrrsets++;
+	return 1;
+}
+
+struct delegpt* 
+dns_cache_find_delegation(struct module_env* env, uint8_t* qname, 
+	size_t qnamelen, uint16_t qtype, uint16_t qclass, 
+	struct regional* region, struct dns_msg** msg, uint32_t now)
+{
+	/* try to find closest NS rrset */
+	struct ub_packed_rrset_key* nskey;
+	struct packed_rrset_data* nsdata;
+	struct delegpt* dp;
+
+	nskey = find_closest_of_type(env, qname, qnamelen, qclass, now,
+		LDNS_RR_TYPE_NS, 0);
+	if(!nskey) /* hope the caller has hints to prime or something */
+		return NULL;
+	nsdata = (struct packed_rrset_data*)nskey->entry.data;
+	/* got the NS key, create delegation point */
+	dp = delegpt_create(region);
+	if(!dp || !delegpt_set_name(dp, region, nskey->rk.dname)) {
+		lock_rw_unlock(&nskey->entry.lock);
+		log_err("find_delegation: out of memory");
+		return NULL;
+	}
+	/* create referral message */
+	if(msg) {
+		/* allocate the array to as much as we could need:
+		 *	NS rrset + DS/NSEC rrset +
+		 *	A rrset for every NS RR
+		 *	AAAA rrset for every NS RR
+		 */
+		*msg = dns_msg_create(qname, qnamelen, qtype, qclass, region, 
+			2 + nsdata->count*2);
+		if(!*msg || !dns_msg_authadd(*msg, region, nskey, now)) {
+			lock_rw_unlock(&nskey->entry.lock);
+			log_err("find_delegation: out of memory");
+			return NULL;
+		}
+	}
+	if(!delegpt_rrset_add_ns(dp, region, nskey, 0))
+		log_err("find_delegation: addns out of memory");
+	lock_rw_unlock(&nskey->entry.lock); /* first unlock before next lookup*/
+	/* find and add DS/NSEC (if any) */
+	if(msg)
+		find_add_ds(env, region, *msg, dp, now);
+	/* find and add A entries */
+	if(!find_add_addrs(env, qclass, region, dp, now, msg))
+		log_err("find_delegation: addrs out of memory");
+	return dp;
+}
+
+/** allocate dns_msg from query_info and reply_info */
+static struct dns_msg*
+gen_dns_msg(struct regional* region, struct query_info* q, size_t num)
+{
+	struct dns_msg* msg = (struct dns_msg*)regional_alloc(region, 
+		sizeof(struct dns_msg));
+	if(!msg)
+		return NULL;
+	memcpy(&msg->qinfo, q, sizeof(struct query_info));
+	msg->qinfo.qname = regional_alloc_init(region, q->qname, q->qname_len);
+	if(!msg->qinfo.qname)
+		return NULL;
+	/* allocate replyinfo struct and rrset key array separately */
+	msg->rep = (struct reply_info*)regional_alloc(region,
+		sizeof(struct reply_info) - sizeof(struct rrset_ref));
+	if(!msg->rep)
+		return NULL;
+	msg->rep->rrsets = (struct ub_packed_rrset_key**)
+		regional_alloc(region,
+		num * sizeof(struct ub_packed_rrset_key*));
+	if(!msg->rep->rrsets)
+		return NULL;
+	return msg;
+}
+
+/** generate dns_msg from cached message */
+static struct dns_msg*
+tomsg(struct module_env* env, struct query_info* q, struct reply_info* r, 
+	struct regional* region, uint32_t now, struct regional* scratch)
+{
+	struct dns_msg* msg;
+	size_t i;
+	if(now > r->ttl)
+		return NULL;
+	msg = gen_dns_msg(region, q, r->rrset_count);
+	if(!msg)
+		return NULL;
+	msg->rep->flags = r->flags;
+	msg->rep->qdcount = r->qdcount;
+	msg->rep->ttl = r->ttl - now;
+	if(r->prefetch_ttl > now)
+		msg->rep->prefetch_ttl = r->prefetch_ttl - now;
+	else	msg->rep->prefetch_ttl = PREFETCH_TTL_CALC(msg->rep->ttl);
+	msg->rep->security = r->security;
+	msg->rep->an_numrrsets = r->an_numrrsets;
+	msg->rep->ns_numrrsets = r->ns_numrrsets;
+	msg->rep->ar_numrrsets = r->ar_numrrsets;
+	msg->rep->rrset_count = r->rrset_count;
+        msg->rep->authoritative = r->authoritative;
+	if(!rrset_array_lock(r->ref, r->rrset_count, now))
+		return NULL;
+	if(r->an_numrrsets > 0 && (r->rrsets[0]->rk.type == htons(
+		LDNS_RR_TYPE_CNAME) || r->rrsets[0]->rk.type == htons(
+		LDNS_RR_TYPE_DNAME)) && !reply_check_cname_chain(r)) {
+		/* cname chain is now invalid, reconstruct msg */
+		rrset_array_unlock(r->ref, r->rrset_count);
+		return NULL;
+	}
+	if(r->security == sec_status_secure && !reply_all_rrsets_secure(r)) {
+		/* message rrsets have changed status, revalidate */
+		rrset_array_unlock(r->ref, r->rrset_count);
+		return NULL;
+	}
+	for(i=0; i<msg->rep->rrset_count; i++) {
+		msg->rep->rrsets[i] = packed_rrset_copy_region(r->rrsets[i], 
+			region, now);
+		if(!msg->rep->rrsets[i]) {
+			rrset_array_unlock(r->ref, r->rrset_count);
+			return NULL;
+		}
+	}
+	rrset_array_unlock_touch(env->rrset_cache, scratch, r->ref, 
+		r->rrset_count);
+	return msg;
+}
+
+/** synthesize RRset-only response from cached RRset item */
+static struct dns_msg*
+rrset_msg(struct ub_packed_rrset_key* rrset, struct regional* region, 
+	uint32_t now, struct query_info* q)
+{
+	struct dns_msg* msg;
+	struct packed_rrset_data* d = (struct packed_rrset_data*)
+		rrset->entry.data;
+	if(now > d->ttl)
+		return NULL;
+	msg = gen_dns_msg(region, q, 1); /* only the CNAME (or other) RRset */
+	if(!msg)
+		return NULL;
+	msg->rep->flags = BIT_QR; /* reply, no AA, no error */
+        msg->rep->authoritative = 0; /* reply stored in cache can't be authoritative */
+	msg->rep->qdcount = 1;
+	msg->rep->ttl = d->ttl - now;
+	msg->rep->prefetch_ttl = PREFETCH_TTL_CALC(msg->rep->ttl);
+	msg->rep->security = sec_status_unchecked;
+	msg->rep->an_numrrsets = 1;
+	msg->rep->ns_numrrsets = 0;
+	msg->rep->ar_numrrsets = 0;
+	msg->rep->rrset_count = 1;
+	msg->rep->rrsets[0] = packed_rrset_copy_region(rrset, region, now);
+	if(!msg->rep->rrsets[0]) /* copy CNAME */
+		return NULL;
+	return msg;
+}
+
+/** synthesize DNAME+CNAME response from cached DNAME item */
+static struct dns_msg*
+synth_dname_msg(struct ub_packed_rrset_key* rrset, struct regional* region, 
+	uint32_t now, struct query_info* q)
+{
+	struct dns_msg* msg;
+	struct ub_packed_rrset_key* ck;
+	struct packed_rrset_data* newd, *d = (struct packed_rrset_data*)
+		rrset->entry.data;
+	uint8_t* newname, *dtarg = NULL;
+	size_t newlen, dtarglen;
+	if(now > d->ttl)
+		return NULL;
+	/* only allow validated (with DNSSEC) DNAMEs used from cache 
+	 * for insecure DNAMEs, query again. */
+	if(d->security != sec_status_secure)
+		return NULL;
+	msg = gen_dns_msg(region, q, 2); /* DNAME + CNAME RRset */
+	if(!msg)
+		return NULL;
+	msg->rep->flags = BIT_QR; /* reply, no AA, no error */
+        msg->rep->authoritative = 0; /* reply stored in cache can't be authoritative */
+	msg->rep->qdcount = 1;
+	msg->rep->ttl = d->ttl - now;
+	msg->rep->prefetch_ttl = PREFETCH_TTL_CALC(msg->rep->ttl);
+	msg->rep->security = sec_status_unchecked;
+	msg->rep->an_numrrsets = 1;
+	msg->rep->ns_numrrsets = 0;
+	msg->rep->ar_numrrsets = 0;
+	msg->rep->rrset_count = 1;
+	msg->rep->rrsets[0] = packed_rrset_copy_region(rrset, region, now);
+	if(!msg->rep->rrsets[0]) /* copy DNAME */
+		return NULL;
+	/* synth CNAME rrset */
+	get_cname_target(rrset, &dtarg, &dtarglen);
+	if(!dtarg)
+		return NULL;
+	newlen = q->qname_len + dtarglen - rrset->rk.dname_len;
+	if(newlen > LDNS_MAX_DOMAINLEN) {
+		msg->rep->flags |= LDNS_RCODE_YXDOMAIN;
+		return msg;
+	}
+	newname = (uint8_t*)regional_alloc(region, newlen);
+	if(!newname)
+		return NULL;
+	/* new name is concatenation of qname front (without DNAME owner)
+	 * and DNAME target name */
+	memcpy(newname, q->qname, q->qname_len-rrset->rk.dname_len);
+	memmove(newname+(q->qname_len-rrset->rk.dname_len), dtarg, dtarglen);
+	/* create rest of CNAME rrset */
+	ck = (struct ub_packed_rrset_key*)regional_alloc(region, 
+		sizeof(struct ub_packed_rrset_key));
+	if(!ck)
+		return NULL;
+	memset(&ck->entry, 0, sizeof(ck->entry));
+	msg->rep->rrsets[1] = ck;
+	ck->entry.key = ck;
+	ck->rk.type = htons(LDNS_RR_TYPE_CNAME);
+	ck->rk.rrset_class = rrset->rk.rrset_class;
+	ck->rk.flags = 0;
+	ck->rk.dname = regional_alloc_init(region, q->qname, q->qname_len);
+	if(!ck->rk.dname)
+		return NULL;
+	ck->rk.dname_len = q->qname_len;
+	ck->entry.hash = rrset_key_hash(&ck->rk);
+	newd = (struct packed_rrset_data*)regional_alloc_zero(region,
+		sizeof(struct packed_rrset_data) + sizeof(size_t) + 
+		sizeof(uint8_t*) + sizeof(uint32_t) + sizeof(uint16_t) 
+		+ newlen);
+	if(!newd)
+		return NULL;
+	ck->entry.data = newd;
+	newd->ttl = 0; /* 0 for synthesized CNAME TTL */
+	newd->count = 1;
+	newd->rrsig_count = 0;
+	newd->trust = rrset_trust_ans_noAA;
+	newd->rr_len = (size_t*)((uint8_t*)newd + 
+		sizeof(struct packed_rrset_data));
+	newd->rr_len[0] = newlen + sizeof(uint16_t);
+	packed_rrset_ptr_fixup(newd);
+	newd->rr_ttl[0] = newd->ttl;
+	msg->rep->ttl = newd->ttl;
+	msg->rep->prefetch_ttl = PREFETCH_TTL_CALC(newd->ttl);
+	ldns_write_uint16(newd->rr_data[0], newlen);
+	memmove(newd->rr_data[0] + sizeof(uint16_t), newname, newlen);
+	msg->rep->an_numrrsets ++;
+	msg->rep->rrset_count ++;
+	return msg;
+}
+
+struct dns_msg* 
+dns_cache_lookup(struct module_env* env,
+	uint8_t* qname, size_t qnamelen, uint16_t qtype, uint16_t qclass,
+	struct regional* region, struct regional* scratch)
+{
+	struct lruhash_entry* e;
+	struct query_info k;
+	hashvalue_t h;
+	uint32_t now = *env->now;
+	struct ub_packed_rrset_key* rrset;
+
+	/* lookup first, this has both NXdomains and ANSWER responses */
+	k.qname = qname;
+	k.qname_len = qnamelen;
+	k.qtype = qtype;
+	k.qclass = qclass;
+	h = query_info_hash(&k);
+	e = slabhash_lookup(env->msg_cache, h, &k, 0);
+	if(e) {
+		struct msgreply_entry* key = (struct msgreply_entry*)e->key;
+		struct reply_info* data = (struct reply_info*)e->data;
+		struct dns_msg* msg = tomsg(env, &key->key, data, region, now, 
+			scratch);
+		if(msg) {
+			lock_rw_unlock(&e->lock);
+			return msg;
+		}
+		/* could be msg==NULL; due to TTL or not all rrsets available */
+		lock_rw_unlock(&e->lock);
+	}
+
+	/* see if a DNAME exists. Checked for first, to enforce that DNAMEs
+	 * are more important, the CNAME is resynthesized and thus 
+	 * consistent with the DNAME */
+	if( (rrset=find_closest_of_type(env, qname, qnamelen, qclass, now,
+		LDNS_RR_TYPE_DNAME, 1))) {
+		/* synthesize a DNAME+CNAME message based on this */
+		struct dns_msg* msg = synth_dname_msg(rrset, region, now, &k);
+		if(msg) {
+			lock_rw_unlock(&rrset->entry.lock);
+			return msg;
+		}
+		lock_rw_unlock(&rrset->entry.lock);
+	}
+
+	/* see if we have CNAME for this domain,
+	 * but not for DS records (which are part of the parent) */
+	if( qtype != LDNS_RR_TYPE_DS &&
+	   (rrset=rrset_cache_lookup(env->rrset_cache, qname, qnamelen, 
+		LDNS_RR_TYPE_CNAME, qclass, 0, now, 0))) {
+		struct dns_msg* msg = rrset_msg(rrset, region, now, &k);
+		if(msg) {
+			lock_rw_unlock(&rrset->entry.lock);
+			return msg;
+		}
+		lock_rw_unlock(&rrset->entry.lock);
+	}
+
+	/* construct DS, DNSKEY, DLV messages from rrset cache. */
+	if((qtype == LDNS_RR_TYPE_DS || qtype == LDNS_RR_TYPE_DNSKEY ||
+		qtype == LDNS_RR_TYPE_DLV) &&
+		(rrset=rrset_cache_lookup(env->rrset_cache, qname, qnamelen, 
+		qtype, qclass, 0, now, 0))) {
+		/* if the rrset is from the additional section, and the
+		 * signatures have fallen off, then do not synthesize a msg
+		 * instead, allow a full query for signed results to happen.
+		 * Forego all rrset data from additional section, because
+		 * some signatures may not be present and cause validation
+		 * failure.
+		 */
+		struct packed_rrset_data *d = (struct packed_rrset_data*)
+			rrset->entry.data;
+		if(d->trust != rrset_trust_add_noAA && 
+			d->trust != rrset_trust_add_AA && 
+			(qtype == LDNS_RR_TYPE_DS || 
+				(d->trust != rrset_trust_auth_noAA 
+				&& d->trust != rrset_trust_auth_AA) )) {
+			struct dns_msg* msg = rrset_msg(rrset, region, now, &k);
+			if(msg) {
+				lock_rw_unlock(&rrset->entry.lock);
+				return msg;
+			}
+		}
+		lock_rw_unlock(&rrset->entry.lock);
+	}
+
+	/* stop downwards cache search on NXDOMAIN.
+	 * Empty nonterminals are NOERROR, so an NXDOMAIN for foo
+	 * means bla.foo also does not exist.  The DNSSEC proofs are
+	 * the same.  We search upwards for NXDOMAINs. */
+	if(env->cfg->harden_below_nxdomain)
+	    while(!dname_is_root(k.qname)) {
+		dname_remove_label(&k.qname, &k.qname_len);
+		h = query_info_hash(&k);
+		e = slabhash_lookup(env->msg_cache, h, &k, 0);
+		if(e) {
+			struct reply_info* data = (struct reply_info*)e->data;
+			struct dns_msg* msg;
+			if(FLAGS_GET_RCODE(data->flags) == LDNS_RCODE_NXDOMAIN
+			  && data->security == sec_status_secure
+			  && (msg=tomsg(env, &k, data, region, now, scratch))){
+				lock_rw_unlock(&e->lock);
+				msg->qinfo.qname=qname;
+				msg->qinfo.qname_len=qnamelen;
+				/* check that DNSSEC really works out */
+				msg->rep->security = sec_status_unchecked;
+				return msg;
+			}
+			lock_rw_unlock(&e->lock);
+		}
+	}
+
+	return NULL;
+}
+
+int 
+dns_cache_store(struct module_env* env, struct query_info* msgqinf,
+        struct reply_info* msgrep, int is_referral, uint32_t leeway,
+	struct regional* region)
+{
+	struct reply_info* rep = NULL;
+	/* alloc, malloc properly (not in region, like msg is) */
+	rep = reply_info_copy(msgrep, env->alloc, NULL);
+	if(!rep)
+		return 0;
+	/* ttl must be relative ;i.e. 0..86400 not  time(0)+86400. 
+	 * the env->now is added to message and RRsets in this routine. */
+	/* the leeway is used to invalidate other rrsets earlier */
+
+	if(is_referral) {
+		/* store rrsets */
+		struct rrset_ref ref;
+		size_t i;
+		for(i=0; i<rep->rrset_count; i++) {
+			packed_rrset_ttl_add((struct packed_rrset_data*)
+				rep->rrsets[i]->entry.data, *env->now);
+			ref.key = rep->rrsets[i];
+			ref.id = rep->rrsets[i]->id;
+			/*ignore ret: it was in the cache, ref updated */
+			(void)rrset_cache_update(env->rrset_cache, &ref, 
+				env->alloc, *env->now + leeway);
+		}
+		free(rep);
+		return 1;
+	} else {
+		/* store msg, and rrsets */
+		struct query_info qinf;
+		hashvalue_t h;
+
+		qinf = *msgqinf;
+		qinf.qname = memdup(msgqinf->qname, msgqinf->qname_len);
+		if(!qinf.qname) {
+			reply_info_parsedelete(rep, env->alloc);
+			return 0;
+		}
+		/* fixup flags to be sensible for a reply based on the cache */
+		/* this module means that RA is available. It is an answer QR. 
+		 * Not AA from cache. Not CD in cache (depends on client bit). */
+		rep->flags |= (BIT_RA | BIT_QR);
+		rep->flags &= ~(BIT_AA | BIT_CD);
+		h = query_info_hash(&qinf);
+		dns_cache_store_msg(env, &qinf, h, rep, leeway, msgrep, region);
+		/* qname is used inside query_info_entrysetup, and set to 
+		 * NULL. If it has not been used, free it. free(0) is safe. */
+		free(qinf.qname);
+	}
+	return 1;
+}