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diff --git a/‎cachedb/cachedb.c
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-2Lines changed: 0 additions & 2 deletions b/‎cachedb/cachedb.c
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-2Lines changed: 0 additions & 2 deletions
diff --git a/‎daemon/remote.c
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+4Lines changed: 4 additions & 0 deletions b/‎daemon/remote.c
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+4Lines changed: 4 additions & 0 deletions
diff --git a/‎daemon/worker.c
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+7-11Lines changed: 7 additions & 11 deletions b/‎daemon/worker.c
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+7-11Lines changed: 7 additions & 11 deletions
diff --git a/‎dns64/dns64.c
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+1Lines changed: 1 addition & 0 deletions b/‎dns64/dns64.c
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+1Lines changed: 1 addition & 0 deletions
diff --git a/‎iterator/iterator.c
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+15-8Lines changed: 15 additions & 8 deletions b/‎iterator/iterator.c
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+15-8Lines changed: 15 additions & 8 deletions
diff --git a/‎services/cache/dns.c
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+35-16Lines changed: 35 additions & 16 deletions b/‎services/cache/dns.c
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+35-16Lines changed: 35 additions & 16 deletions
diff --git a/‎services/cache/rrset.c
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+5-5Lines changed: 5 additions & 5 deletions b/‎services/cache/rrset.c
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+5-5Lines changed: 5 additions & 5 deletions
diff --git a/‎services/mesh.c
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+9-4Lines changed: 9 additions & 4 deletions b/‎services/mesh.c
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+9-4Lines changed: 9 additions & 4 deletions
diff --git a/‎services/mesh.h
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+2-1Lines changed: 2 additions & 1 deletion b/‎services/mesh.h
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+2-1Lines changed: 2 additions & 1 deletion
diff --git a/‎services/rpz.c
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+4Lines changed: 4 additions & 0 deletions b/‎services/rpz.c
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+4Lines changed: 4 additions & 0 deletions
@@ -828,8 +828,6 @@ cachedb_handle_query(struct module_qstate* qstate,
 		/* In case we have expired data but there is a client timer for expired
 		 * answers, pass execution to next module in order to try updating the
 		 * data first.
-		 * TODO: this needs revisit. The expired data stored from cachedb has
-		 * 0 TTL which is picked up by iterator later when looking in the cache.
 		 */
 		if(qstate->env->cfg->serve_expired && msg_expired) {
 			qstate->return_msg = NULL;
 
@@ -1953,6 +1953,8 @@ bogus_del_msg(struct lruhash_entry* e, void* arg)
 	struct reply_info* d = (struct reply_info*)e->data;
 	if(d->security == sec_status_bogus) {
 		d->ttl = inf->expired;
+		d->prefetch_ttl = inf->expired;
+		d->serve_expired_ttl = inf->expired;
 		inf->num_msgs++;
 #ifdef USE_CACHEDB
 		if(inf->remcachedb && inf->worker->env.cachedb_enabled)
@@ -2035,6 +2037,8 @@ negative_del_msg(struct lruhash_entry* e, void* arg)
 	 * or NOERROR rcode with ANCOUNT==0: a NODATA answer */
 	if(FLAGS_GET_RCODE(d->flags) != 0 || d->an_numrrsets == 0) {
 		d->ttl = inf->expired;
+		d->prefetch_ttl = inf->expired;
+		d->serve_expired_ttl = inf->expired;
 		inf->num_msgs++;
 #ifdef USE_CACHEDB
 		if(inf->remcachedb && inf->worker->env.cachedb_enabled)
 
@@ -661,22 +661,18 @@ answer_from_cache(struct worker* worker, struct query_info* qinfo,
 	if(rep->ttl < timenow) {
 		/* Check if we need to serve expired now */
 		if(worker->env.cfg->serve_expired &&
-			!worker->env.cfg->serve_expired_client_timeout
+			/* if serve-expired-client-timeout is set, serve
+			 * an expired record without attempting recursion
+			 * if the serve_expired_norec_ttl is set for the record
+			 * as we know that recursion is currently failing. */
+			(!worker->env.cfg->serve_expired_client_timeout ||
+			 timenow < rep->serve_expired_norec_ttl)
 #ifdef USE_CACHEDB
 			&& !(worker->env.cachedb_enabled &&
 			  worker->env.cfg->cachedb_check_when_serve_expired)
 #endif
 			) {
-				if(worker->env.cfg->serve_expired_ttl &&
-					rep->serve_expired_ttl < timenow)
-					return 0;
-				/* Ignore expired failure answers */
-				if(FLAGS_GET_RCODE(rep->flags) !=
-					LDNS_RCODE_NOERROR &&
-					FLAGS_GET_RCODE(rep->flags) !=
-					LDNS_RCODE_NXDOMAIN &&
-					FLAGS_GET_RCODE(rep->flags) !=
-					LDNS_RCODE_YXDOMAIN)
+				if(!reply_info_can_answer_expired(rep, timenow))
 					return 0;
 				if(!rrset_array_lock(rep->ref, rep->rrset_count, 0))
 					return 0;
 
@@ -847,6 +847,7 @@ dns64_adjust_a(int id, struct module_qstate* super, struct module_qstate* qstate
 	 */
 	cp = construct_reply_info_base(super->region, rep->flags, rep->qdcount,
 		rep->ttl, rep->prefetch_ttl, rep->serve_expired_ttl,
+		rep->serve_expired_norec_ttl,
 		rep->an_numrrsets, rep->ns_numrrsets, rep->ar_numrrsets,
 		rep->rrset_count, rep->security, LDNS_EDE_NONE);
 	if(!cp)
 
@@ -322,16 +322,21 @@ error_response_cache(struct module_qstate* qstate, int id, int rcode)
 		qstate->qinfo.qname, qstate->qinfo.qname_len,
 		qstate->qinfo.qtype, qstate->qinfo.qclass,
 		qstate->query_flags, 0,
-		qstate->env->cfg->serve_expired_ttl_reset)) != NULL) {
+		qstate->env->cfg->serve_expired)) != NULL) {
 		struct reply_info* rep = (struct reply_info*)msg->entry.data;
-		if(qstate->env->cfg->serve_expired &&
-			qstate->env->cfg->serve_expired_ttl_reset && rep &&
-			*qstate->env->now + qstate->env->cfg->serve_expired_ttl
-			> rep->serve_expired_ttl) {
-			verbose(VERB_ALGO, "reset serve-expired-ttl for "
+		if(qstate->env->cfg->serve_expired && rep) {
+			if(qstate->env->cfg->serve_expired_ttl_reset &&
+				*qstate->env->now + qstate->env->cfg->serve_expired_ttl
+				> rep->serve_expired_ttl) {
+				verbose(VERB_ALGO, "reset serve-expired-ttl for "
+					"response in cache");
+				rep->serve_expired_ttl = *qstate->env->now +
+					qstate->env->cfg->serve_expired_ttl;
+			}
+			verbose(VERB_ALGO, "set serve-expired-norec-ttl for "
 				"response in cache");
-			rep->serve_expired_ttl = *qstate->env->now +
-				qstate->env->cfg->serve_expired_ttl;
+			rep->serve_expired_norec_ttl = NORR_TTL +
+				*qstate->env->now;
 		}
 		if(rep && (FLAGS_GET_RCODE(rep->flags) ==
 			LDNS_RCODE_NOERROR ||
@@ -4046,6 +4051,8 @@ processClassResponse(struct module_qstate* qstate, int id,
 			to->rep->prefetch_ttl = from->rep->prefetch_ttl;
 		if(from->rep->serve_expired_ttl < to->rep->serve_expired_ttl)
 			to->rep->serve_expired_ttl = from->rep->serve_expired_ttl;
+		if(from->rep->serve_expired_norec_ttl < to->rep->serve_expired_norec_ttl)
+			to->rep->serve_expired_norec_ttl = from->rep->serve_expired_norec_ttl;
 	}
 	/* are we done? */
 	foriq->num_current_queries --;
 
@@ -162,7 +162,7 @@ dns_cache_store_msg(struct module_env* env, struct query_info* qinfo,
 	size_t i;
 
 	/* store RRsets */
-        for(i=0; i<rep->rrset_count; i++) {
+	for(i=0; i<rep->rrset_count; i++) {
 		rep->ref[i].key = rep->rrsets[i];
 		rep->ref[i].id = rep->rrsets[i]->id;
 	}
@@ -197,6 +197,7 @@ dns_cache_store_msg(struct module_env* env, struct query_info* qinfo,
 	reply_info_sortref(rep);
 	if(!(e = query_info_entrysetup(qinfo, rep, hash))) {
 		log_err("store_msg: malloc failed");
+		reply_info_delete(rep, NULL);
 		return;
 	}
 	slabhash_insert(env->msg_cache, hash, &e->entry, rep, env->alloc);
@@ -607,22 +608,8 @@ tomsg(struct module_env* env, struct query_info* q, struct reply_info* r,
 	time_t now_control = now;
 	if(now > r->ttl) {
 		/* Check if we are allowed to serve expired */
-		if(allow_expired) {
-			if(env->cfg->serve_expired_ttl &&
-				r->serve_expired_ttl < now) {
-				return NULL;
-			}
-			/* Ignore expired failure answers */
-			if(FLAGS_GET_RCODE(r->flags) !=
-				LDNS_RCODE_NOERROR &&
-				FLAGS_GET_RCODE(r->flags) !=
-				LDNS_RCODE_NXDOMAIN &&
-				FLAGS_GET_RCODE(r->flags) !=
-				LDNS_RCODE_YXDOMAIN)
-				return 0;
-		} else {
+		if(!allow_expired || !reply_info_can_answer_expired(r, now))
 			return NULL;
-		}
 		/* Change the current time so we can pass the below TTL checks when
 		 * serving expired data. */
 		now_control = r->ttl - env->cfg->serve_expired_reply_ttl;
@@ -641,6 +628,7 @@ tomsg(struct module_env* env, struct query_info* q, struct reply_info* r,
 	else
 		msg->rep->prefetch_ttl = PREFETCH_TTL_CALC(msg->rep->ttl);
 	msg->rep->serve_expired_ttl = msg->rep->ttl + SERVE_EXPIRED_TTL;
+	msg->rep->serve_expired_norec_ttl = 0;
 	msg->rep->security = r->security;
 	msg->rep->an_numrrsets = r->an_numrrsets;
 	msg->rep->ns_numrrsets = r->ns_numrrsets;
@@ -724,6 +712,7 @@ rrset_msg(struct ub_packed_rrset_key* rrset, struct regional* region,
 	msg->rep->ttl = d->ttl - now;
 	msg->rep->prefetch_ttl = PREFETCH_TTL_CALC(msg->rep->ttl);
 	msg->rep->serve_expired_ttl = msg->rep->ttl + SERVE_EXPIRED_TTL;
+	msg->rep->serve_expired_norec_ttl = 0;
 	msg->rep->security = sec_status_unchecked;
 	msg->rep->an_numrrsets = 1;
 	msg->rep->ns_numrrsets = 0;
@@ -763,6 +752,7 @@ synth_dname_msg(struct ub_packed_rrset_key* rrset, struct regional* region,
 	msg->rep->ttl = d->ttl - now;
 	msg->rep->prefetch_ttl = PREFETCH_TTL_CALC(msg->rep->ttl);
 	msg->rep->serve_expired_ttl = msg->rep->ttl + SERVE_EXPIRED_TTL;
+	msg->rep->serve_expired_norec_ttl = 0;
 	msg->rep->security = sec_status_unchecked;
 	msg->rep->an_numrrsets = 1;
 	msg->rep->ns_numrrsets = 0;
@@ -1070,6 +1060,35 @@ dns_cache_store(struct module_env* env, struct query_info* msgqinf,
 	struct regional* region, uint32_t flags, time_t qstarttime)
 {
 	struct reply_info* rep = NULL;
+	if(SERVE_EXPIRED) {
+		/* We are serving expired records. Before caching, check if a
+		 * useful expired record exists. */
+		struct msgreply_entry* e = msg_cache_lookup(env,
+			msgqinf->qname, msgqinf->qname_len, msgqinf->qtype,
+			msgqinf->qclass, flags, 0, 0);
+		if(e) {
+			struct reply_info* cached = e->entry.data;
+			if(cached->ttl < *env->now
+				&& reply_info_could_use_expired(cached, *env->now)
+				/* If we are validating make sure only
+				 * validating modules can update such messages.
+				 * In that case don't cache it and let a
+				 * subsequent module handle the caching. For
+				 * example, the iterator should not replace an
+				 * expired secure answer with a fresh unchecked
+				 * one and let the validator manage caching. */
+				&& cached->security != sec_status_bogus
+				&& (env->need_to_validate &&
+				msgrep->security == sec_status_unchecked)) {
+				verbose(VERB_ALGO, "a validated expired entry "
+					"could be overwritten, skip caching "
+					"the new message at this stage");
+				lock_rw_unlock(&e->entry.lock);
+				return 1;
+			}
+			lock_rw_unlock(&e->entry.lock);
+		}
+	}
 	/* alloc, malloc properly (not in region, like msg is) */
 	rep = reply_info_copy(msgrep, env->alloc, NULL);
 	if(!rep)
 
@@ -128,8 +128,8 @@ need_to_update_rrset(void* nd, void* cd, time_t timenow, int equal, int ns)
 {
 	struct packed_rrset_data* newd = (struct packed_rrset_data*)nd;
 	struct packed_rrset_data* cached = (struct packed_rrset_data*)cd;
-	/*	o if new data is expired, current data is better */
-	if( newd->ttl < timenow && cached->ttl >= timenow)
+	/*	o if new data is expired, cached data is better */
+	if( newd->ttl < timenow && timenow <= cached->ttl)
 		return 0;
 	/* 	o store if rrset has been validated 
 	 *  		everything better than bogus data 
@@ -140,9 +140,9 @@ need_to_update_rrset(void* nd, void* cd, time_t timenow, int equal, int ns)
 	if( cached->security == sec_status_bogus && 
 		newd->security != sec_status_bogus && !equal)
 		return 1;
-        /*      o if current RRset is more trustworthy - insert it */
+        /*      o if new RRset is more trustworthy - insert it */
         if( newd->trust > cached->trust ) {
-		/* if the cached rrset is bogus, and this one equal,
+		/* if the cached rrset is bogus, and new is equal,
 		 * do not update the TTL - let it expire. */
 		if(equal && cached->ttl >= timenow && 
 			cached->security == sec_status_bogus)
@@ -155,7 +155,7 @@ need_to_update_rrset(void* nd, void* cd, time_t timenow, int equal, int ns)
 	/*  o same trust, but different in data - insert it */
 	if( newd->trust == cached->trust && !equal ) {
 		/* if this is type NS, do not 'stick' to owner that changes
-		 * the NS RRset, but use the old TTL for the new data, and
+		 * the NS RRset, but use the cached TTL for the new data, and
 		 * update to fetch the latest data. ttl is not expired, because
 		 * that check was before this one. */
 		if(ns) {
 
@@ -311,7 +311,7 @@ int mesh_make_new_space(struct mesh_area* mesh, sldns_buffer* qbuf)
 
 struct dns_msg*
 mesh_serve_expired_lookup(struct module_qstate* qstate,
-	struct query_info* lookup_qinfo)
+	struct query_info* lookup_qinfo, int* is_expired)
 {
 	hashvalue_type h;
 	struct lruhash_entry* e;
@@ -321,13 +321,15 @@ mesh_serve_expired_lookup(struct module_qstate* qstate,
 	time_t timenow = *qstate->env->now;
 	int must_validate = (!(qstate->query_flags&BIT_CD)
 		|| qstate->env->cfg->ignore_cd) && qstate->env->need_to_validate;
+	*is_expired = 0;
 	/* Lookup cache */
 	h = query_info_hash(lookup_qinfo, qstate->query_flags);
 	e = slabhash_lookup(qstate->env->msg_cache, h, lookup_qinfo, 0);
 	if(!e) return NULL;
 
 	key = (struct msgreply_entry*)e->key;
 	data = (struct reply_info*)e->data;
+	if(data->ttl < timenow) *is_expired = 1;
 	msg = tomsg(qstate->env, &key->key, data, qstate->region, timenow,
 		qstate->env->cfg->serve_expired, qstate->env->scratch);
 	if(!msg)
@@ -2176,6 +2178,7 @@ mesh_serve_expired_callback(void* arg)
 	int must_validate = (!(qstate->query_flags&BIT_CD)
 		|| qstate->env->cfg->ignore_cd) && qstate->env->need_to_validate;
 	int i = 0;
+	int is_expired;
 	if(!qstate->serve_expired_data) return;
 	verbose(VERB_ALGO, "Serve expired: Trying to reply with expired data");
 	comm_timer_delete(qstate->serve_expired_data->timer);
@@ -2193,7 +2196,7 @@ mesh_serve_expired_callback(void* arg)
 		fptr_ok(fptr_whitelist_serve_expired_lookup(
 			qstate->serve_expired_data->get_cached_answer));
 		msg = (*qstate->serve_expired_data->get_cached_answer)(qstate,
-			lookup_qinfo);
+			lookup_qinfo, &is_expired);
 		if(!msg)
 			return;
 		/* Reset these in case we pass a second time from here. */
@@ -2285,8 +2288,10 @@ mesh_serve_expired_callback(void* arg)
 
 		/* Add EDE Stale Answer (RCF8914). Ignore global ede as this is
 		 * warning instead of an error */
-		if (r->edns.edns_present && qstate->env->cfg->ede_serve_expired &&
-			qstate->env->cfg->ede) {
+		if(r->edns.edns_present &&
+			qstate->env->cfg->ede_serve_expired &&
+			qstate->env->cfg->ede &&
+			is_expired) {
 			edns_opt_list_append_ede(&r->edns.opt_list_out,
 				mstate->s.region, LDNS_EDE_STALE_ANSWER, NULL);
 		}
 
@@ -673,11 +673,12 @@ void mesh_serve_expired_callback(void* arg);
  * the same behavior as when replying from cache.
  * @param qstate: the module qstate.
  * @param lookup_qinfo: the query info to look for in the cache.
+ * @param is_expired: set if the cached answer is expired.
  * @return dns_msg if a cached answer was found, otherwise NULL.
  */
 struct dns_msg*
 mesh_serve_expired_lookup(struct module_qstate* qstate,
-	struct query_info* lookup_qinfo);
+	struct query_info* lookup_qinfo, int* is_expired);
 
 /**
  * See if the mesh has space for more queries. You can allocate queries
 
@@ -1969,6 +1969,7 @@ rpz_synthesize_nodata(struct rpz* ATTR_UNUSED(r), struct module_qstate* ms,
 					     0, /* ttl */
 					     0, /* prettl */
 					     0, /* expttl */
+					     0, /* norecttl */
 					     0, /* an */
 					     0, /* ns */
 					     0, /* ar */
@@ -1999,6 +2000,7 @@ rpz_synthesize_nxdomain(struct rpz* r, struct module_qstate* ms,
 					     0, /* ttl */
 					     0, /* prettl */
 					     0, /* expttl */
+					     0, /* norecttl */
 					     0, /* an */
 					     0, /* ns */
 					     0, /* ar */
@@ -2031,6 +2033,7 @@ rpz_synthesize_localdata_from_rrset(struct rpz* ATTR_UNUSED(r), struct module_qs
                                                    0, /* ttl */
                                                    0, /* prettl */
                                                    0, /* expttl */
+                                                   0, /* norecttl */
                                                    1, /* an */
                                                    0, /* ns */
                                                    0, /* ar */
@@ -2176,6 +2179,7 @@ rpz_synthesize_cname_override_msg(struct rpz* r, struct module_qstate* ms,
                                                    0, /* ttl */
                                                    0, /* prettl */
                                                    0, /* expttl */
+                                                   0, /* norecttl */
                                                    1, /* an */
                                                    0, /* ns */
                                                    0, /* ar */