Recursion lame is detected and last resort is used to resolve.

git-svn-id: file:///svn/unbound/trunk@1294 be551aaa-1e26-0410-a405-d3ace91eadb9

doc/Changelog

@@ -1,3 +1,8 @@
+13 October 2008: Wouter
+	- fixed recursion servers deployed as authoritative detection, so
+	  that as a last resort, a +RD query is sent there to get the 
+	  correct answer.
+
 10 October 2008: Wouter
 	- fixup tests - the negative cache contained the correct NSEC3s for
 	  two tests that are supposed to fail to validate.

iterator/iter_resptype.c

@@ -116,7 +116,7 @@ response_type_from_server(int rdset,
 		/* make sure its not recursive when we don't want it to */
 		if( (msg->rep->flags&BIT_RA) &&
 			!(msg->rep->flags&BIT_AA) && !rdset)
-				return RESPONSE_TYPE_LAME;
+				return RESPONSE_TYPE_REC_LAME;
 		return RESPONSE_TYPE_ANSWER;
 	}
 	
@@ -200,7 +200,7 @@ response_type_from_server(int rdset,
 			/* we do our own recursion, thank you */
 			if( (msg->rep->flags&BIT_RA) &&
 				!(msg->rep->flags&BIT_AA) && !rdset)
-				return RESPONSE_TYPE_LAME;
+				return RESPONSE_TYPE_REC_LAME;
 			return RESPONSE_TYPE_ANSWER;
 		}
 	}
@@ -222,13 +222,13 @@ response_type_from_server(int rdset,
 				 * deployed and is responding nonAA */
 				if( (msg->rep->flags&BIT_RA) &&
 					!(msg->rep->flags&BIT_AA) && !rdset)
-					return RESPONSE_TYPE_LAME;
+					return RESPONSE_TYPE_REC_LAME;
 				/* Or if a lame server is deployed,
 				 * which gives ns==zone delegation from cache 
 				 * without AA bit as well, with nodata nosoa*/
 				if(msg->rep->an_numrrsets==0 &&
 					!(msg->rep->flags&BIT_AA) && !rdset)
-					return RESPONSE_TYPE_LAME;
+					return RESPONSE_TYPE_REC_LAME;
 				return RESPONSE_TYPE_ANSWER;
 			}
 			/* If we are getting a referral upwards (or to 
@@ -259,6 +259,6 @@ response_type_from_server(int rdset,
 	 * be an entirely empty message) */
 	/* check if recursive answer; saying it has empty cache */
 	if( (msg->rep->flags&BIT_RA) && !(msg->rep->flags&BIT_AA) && !rdset)
-		return RESPONSE_TYPE_LAME;
+		return RESPONSE_TYPE_REC_LAME;
 	return RESPONSE_TYPE_ANSWER;
 }

iterator/iter_resptype.h

@@ -81,7 +81,14 @@ enum response_type {
 	 * 'lame' means that this particular response indicates that 
 	 * the nameserver knew nothing about the question.
 	 */
-	RESPONSE_TYPE_LAME
+	RESPONSE_TYPE_LAME,
+
+	/**
+	 * Recursion lame means that the nameserver is some sort of
+	 * open recursor, and not authoritative for the question.
+	 * It may know something, but not authoritatively.
+	 */
+	RESPONSE_TYPE_REC_LAME
 };
 
 /**

iterator/iter_utils.c

@@ -140,9 +140,7 @@ iter_filter_unsuitable(struct iter_env* iter_env, struct module_env* env,
 	uint8_t* name, size_t namelen, uint16_t qtype, uint32_t now, 
 	struct delegpt_addr* a)
 {
-	int rtt;
+	int rtt, lame, reclame, dnsseclame;
-	int lame;
-	int dnsseclame;
 	if(donotq_lookup(iter_env->donotq, &a->addr, a->addrlen)) {
 		return -1; /* server is on the donotquery list */
 	}
@@ -151,12 +149,15 @@ iter_filter_unsuitable(struct iter_env* iter_env, struct module_env* env,
 	}
 	/* check lameness - need zone , class info */
 	if(infra_get_lame_rtt(env->infra_cache, &a->addr, a->addrlen, 
-		name, namelen, qtype, &lame, &dnsseclame, &rtt, now)) {
+		name, namelen, qtype, &lame, &dnsseclame, &reclame, 
+		&rtt, now)) {
 		if(lame)
 			return -1; /* server is lame */
 		else if(rtt >= USEFUL_SERVER_TOP_TIMEOUT)
 			return -1; /* server is unresponsive */
-		else if(dnsseclame)
+		else if(reclame)
+			return rtt+USEFUL_SERVER_TOP_TIMEOUT*2; /* nonpref */
+		else if(dnsseclame )
 			return rtt+USEFUL_SERVER_TOP_TIMEOUT; /* nonpref */
 		else	return rtt;
 	}
@@ -240,7 +241,8 @@ iter_filter_order(struct iter_env* iter_env, struct module_env* env,
 struct delegpt_addr* 
 iter_server_selection(struct iter_env* iter_env, 
 	struct module_env* env, struct delegpt* dp, 
-	uint8_t* name, size_t namelen, uint16_t qtype, int* dnssec_expected)
+	uint8_t* name, size_t namelen, uint16_t qtype, int* dnssec_expected,
+	int* chase_to_rd)
 {
 	int sel;
 	int selrtt;
@@ -250,8 +252,12 @@ iter_server_selection(struct iter_env* iter_env,
 
 	if(num == 0)
 		return NULL;
-	if(selrtt >= USEFUL_SERVER_TOP_TIMEOUT)
+	if(selrtt >= USEFUL_SERVER_TOP_TIMEOUT*2) {
+		*chase_to_rd = 1;
+	}
+	if(selrtt >= USEFUL_SERVER_TOP_TIMEOUT) {
 		*dnssec_expected = 0;
+	}
 	if(num == 1) {
 		a = dp->result_list;
 		if(++a->attempts < OUTBOUND_MSG_RETRY)

iterator/iter_utils.h

@@ -77,12 +77,15 @@ int iter_apply_cfg(struct iter_env* iter_env, struct config_file* cfg);
  * @param qtype: query type that we want to send.
  * @param dnssec_expected: set to 0, if a known dnssec-lame server is selected
  *	these are not preferred, but are used as a last resort.
+ * @param chase_to_rd: set to 1 if a known recursion lame server is selected
+ * 	these are not preferred, but are used as a last resort.
  * @return best target or NULL if no target.
  *	if not null, that target is removed from the result list in the dp.
  */
 struct delegpt_addr* iter_server_selection(struct iter_env* iter_env, 
 	struct module_env* env, struct delegpt* dp, uint8_t* name, 
-	size_t namelen, uint16_t qtype, int* dnssec_expected);
+	size_t namelen, uint16_t qtype, int* dnssec_expected,
+	int* chase_to_rd);
 
 /**
  * Allocate dns_msg from parsed msg, in regional.

iterator/iterator.c

@@ -1211,7 +1211,7 @@ processQueryTargets(struct module_qstate* qstate, struct iter_qstate* iq,
 	/* Select the next usable target, filtering out unsuitable targets. */
 	target = iter_server_selection(ie, qstate->env, iq->dp, 
 		iq->dp->name, iq->dp->namelen, iq->qchase.qtype,
-		&iq->dnssec_expected);
+		&iq->dnssec_expected, &iq->chase_to_rd);
 
 	/* If no usable target was selected... */
 	if(!target) {
@@ -1276,7 +1276,7 @@ processQueryTargets(struct module_qstate* qstate, struct iter_qstate* iq,
 	outq = (*qstate->env->send_query)(
 		iq->qchase.qname, iq->qchase.qname_len, 
 		iq->qchase.qtype, iq->qchase.qclass, 
-		iq->chase_flags, EDNS_DO|BIT_CD, 
+		iq->chase_flags | (iq->chase_to_rd?BIT_RD:0), EDNS_DO|BIT_CD, 
 		&target->addr, target->addrlen, qstate);
 	if(!outq) {
 		verbose(VERB_OPS, "error sending query to auth server; "
@@ -1313,11 +1313,14 @@ processQueryResponse(struct module_qstate* qstate, struct iter_qstate* iq,
 	enum response_type type;
 	iq->num_current_queries--;
 	if(iq->response == NULL) {
+		iq->chase_to_rd = 0;
 		verbose(VERB_ALGO, "query response was timeout");
 		return next_state(iq, QUERYTARGETS_STATE);
 	}
-	type = response_type_from_server((int)(iq->chase_flags&BIT_RD),
+	type = response_type_from_server(
+		(int)((iq->chase_flags&BIT_RD) || iq->chase_to_rd),
 		iq->response, &iq->qchase, iq->dp);
+	iq->chase_to_rd = 0;
 	if(type == RESPONSE_TYPE_REFERRAL && (iq->chase_flags&BIT_RD)) {
 		/* When forwarding (RD bit is set), we handle referrals 
 		 * differently. No queries should be sent elsewhere */
@@ -1325,6 +1328,7 @@ processQueryResponse(struct module_qstate* qstate, struct iter_qstate* iq,
 	}
 	if(iq->dnssec_expected && !(iq->chase_flags&BIT_RD) 
 		&& type != RESPONSE_TYPE_LAME 
+		&& type != RESPONSE_TYPE_REC_LAME 
 		&& type != RESPONSE_TYPE_THROWAWAY 
 		&& type != RESPONSE_TYPE_UNTYPED) {
 		/* a possible answer, see if it is missing DNSSEC */
@@ -1458,11 +1462,24 @@ processQueryResponse(struct module_qstate* qstate, struct iter_qstate* iq,
 			if(!infra_set_lame(qstate->env->infra_cache, 
 				&qstate->reply->addr, qstate->reply->addrlen, 
 				iq->dp->name, iq->dp->namelen, 
-				*qstate->env->now, dnsseclame, 
+				*qstate->env->now, dnsseclame, 0,
 				iq->qchase.qtype))
 				log_err("mark host lame: out of memory");
 		} else log_err("%slame response from cache",
 			dnsseclame?"DNSSEC ":"");
+	} else if(type == RESPONSE_TYPE_REC_LAME) {
+		/* Cache the LAMEness. */
+		verbose(VERB_DETAIL, "query response REC_LAME: "
+			"recursive but not authoritative server");
+		if(qstate->reply) {
+			/* need addr for lameness cache, but we may have
+			 * gotten this from cache, so test to be sure */
+			if(!infra_set_lame(qstate->env->infra_cache, 
+				&qstate->reply->addr, qstate->reply->addrlen, 
+				iq->dp->name, iq->dp->namelen, 
+				*qstate->env->now, 0, 1, iq->qchase.qtype))
+				log_err("mark host lame: out of memory");
+		} 
 	} else if(type == RESPONSE_TYPE_THROWAWAY) {
 		/* LAME and THROWAWAY responses are handled the same way. 
 		 * In this case, the event is just sent directly back to 

iterator/iterator.h

@@ -210,6 +210,8 @@ struct iter_qstate {
 	struct query_info qchase;
 	/** query flags to use when chasing the answer (i.e. RD flag) */
 	uint16_t chase_flags;
+	/** true if we set RD bit because of last resort recursion lame query*/
+	int chase_to_rd;
 
 	/** 
 	 * This is the current delegation point for an in-progress query. This

services/cache/infra.c

@@ -266,7 +266,7 @@ hash_lameness(uint8_t* name, size_t namelen)
 int 
 infra_lookup_lame(struct infra_host_data* host,
         uint8_t* name, size_t namelen, uint32_t timenow,
-	int* dlame, int* alame, int* olame)
+	int* dlame, int* rlame, int* alame, int* olame)
 {
 	struct lruhash_entry* e;
 	struct infra_lame_key k;
@@ -287,10 +287,11 @@ infra_lookup_lame(struct infra_host_data* host,
 		return 0;
 	}
 	*dlame = d->isdnsseclame;
+	*rlame = d->rec_lame;
 	*alame = d->lame_type_A;
 	*olame = d->lame_other;
 	lock_rw_unlock(&e->lock);
-	return *dlame || *alame || *olame;
+	return *dlame || *rlame || *alame || *olame;
 }
 
 size_t 
@@ -337,7 +338,7 @@ int
 infra_set_lame(struct infra_cache* infra,
         struct sockaddr_storage* addr, socklen_t addrlen,
         uint8_t* name, size_t namelen, uint32_t timenow, int dnsseclame,
-	uint16_t qtype)
+	int reclame, uint16_t qtype)
 {
 	struct infra_host_data* data;
 	struct lruhash_entry* e;
@@ -369,8 +370,9 @@ infra_set_lame(struct infra_cache* infra,
 	k->entry.data = (void*)d;
 	d->ttl = timenow + infra->lame_ttl;
 	d->isdnsseclame = dnsseclame;
-	d->lame_type_A = (!dnsseclame && qtype == LDNS_RR_TYPE_A);
+	d->rec_lame = reclame;
-	d->lame_other = (!dnsseclame && qtype != LDNS_RR_TYPE_A);
+	d->lame_type_A = (!dnsseclame && !reclame && qtype == LDNS_RR_TYPE_A);
+	d->lame_other = (!dnsseclame  && !reclame && qtype != LDNS_RR_TYPE_A);
 	k->namelen = namelen;
 	e = infra_lookup_host_nottl(infra, addr, addrlen, 1);
 	if(!e) {
@@ -404,11 +406,12 @@ infra_set_lame(struct infra_cache* infra,
 		}
 	} else {
 		/* lookup existing lameness entry (if any) and merge data */
-		int dlame, alame, olame; 
+		int dlame, rlame, alame, olame; 
 		if(infra_lookup_lame(data, name, namelen, timenow,
-			&dlame, &alame, &olame)) { 
+			&dlame, &rlame, &alame, &olame)) { 
 			/* merge data into new structure */
 			if(dlame) d->isdnsseclame = 1;
+			if(rlame) d->rec_lame = 1;
 			if(alame) d->lame_type_A = 1;
 			if(olame) d->lame_other = 1;
 		}
@@ -500,38 +503,49 @@ int
 infra_get_lame_rtt(struct infra_cache* infra,
         struct sockaddr_storage* addr, socklen_t addrlen,
         uint8_t* name, size_t namelen, uint16_t qtype, 
-	int* lame, int* dnsseclame, int* rtt, uint32_t timenow)
+	int* lame, int* dnsseclame, int* reclame, int* rtt, uint32_t timenow)
 {
 	struct infra_host_data* host;
 	struct lruhash_entry* e = infra_lookup_host_nottl(infra, addr, 
 		addrlen, 0);
-	int dlm, alm, olm;
+	int dlm, rlm, alm, olm;
 	if(!e) 
 		return 0;
 	host = (struct infra_host_data*)e->data;
 	*rtt = rtt_unclamped(&host->rtt);
 	/* check lameness first, if so, ttl on host does not matter anymore */
-	if(infra_lookup_lame(host, name, namelen, timenow, &dlm, &alm, &olm)) {
+	if(infra_lookup_lame(host, name, namelen, timenow, 
+		&dlm, &rlm, &alm, &olm)) {
 		if(alm && qtype == LDNS_RR_TYPE_A) {
 			lock_rw_unlock(&e->lock);
 			*lame = 1;
 			*dnsseclame = 0;
+			*reclame = 0;
 			return 1;
 		} else if(olm && qtype != LDNS_RR_TYPE_A) {
 			lock_rw_unlock(&e->lock);
 			*lame = 1;
 			*dnsseclame = 0;
+			*reclame = 0;
 			return 1;
 		} else if(dlm) {
 			lock_rw_unlock(&e->lock);
 			*lame = 0;
 			*dnsseclame = 1;
+			*reclame = 0;
+			return 1;
+		} else if(rlm) {
+			lock_rw_unlock(&e->lock);
+			*lame = 0;
+			*dnsseclame = 0;
+			*reclame = 1;
 			return 1;
 		}
 		/* no lameness for this type of query */
 	}
 	*lame = 0;
 	*dnsseclame = 0;
+	*reclame = 0;
 	if(timenow > host->ttl) {
 		lock_rw_unlock(&e->lock);
 		return 0;

services/cache/infra.h

@@ -98,6 +98,8 @@ struct infra_lame_data {
 	/** is the host lame (does not serve the zone authoritatively),
 	 * or is the host dnssec lame (does not serve DNSSEC data) */
 	int isdnsseclame;
+	/** is the host recursion lame (not AA, but RA) */
+	int rec_lame;
 	/** the host is lame (not authoritative) for A records */
 	int lame_type_A;
 	/** the host is lame (not authoritative) for other query types */
@@ -187,13 +189,14 @@ int infra_host(struct infra_cache* infra, struct sockaddr_storage* addr,
  * @param namelen: length of domain name.
  * @param timenow: what time it is now.
  * @param dlame: if the function returns true, is set true if dnssec lame.
+ * @param rlame: if the function returns true, is set true if recursion lame.
  * @param alame: if the function returns true, is set true if qtype A lame.
  * @param olame: if the function returns true, is set true if qtype other lame.
  * @return: 0 if not lame or unknown or timed out, 1 if lame
  */
 int infra_lookup_lame(struct infra_host_data* host,
 	uint8_t* name, size_t namelen, uint32_t timenow,
-	int* dlame, int* alame, int* olame);
+	int* dlame, int* rlame, int* alame, int* olame);
 
 /**
  * Set a host to be lame for the given zone.
@@ -205,13 +208,15 @@ int infra_lookup_lame(struct infra_host_data* host,
  * @param timenow: what time it is now.
  * @param dnsseclame: if true the host is set dnssec lame.
  *	if false, the host is marked lame (not serving the zone).
+ * @param reclame: if true host is a recursor not AA server.
+ *      if false, dnsseclame or marked lame.
  * @param qtype: the query type for which it is lame.
  * @return: 0 on error.
  */
 int infra_set_lame(struct infra_cache* infra,
         struct sockaddr_storage* addr, socklen_t addrlen,
 	uint8_t* name, size_t namelen, uint32_t timenow, int dnsseclame,
-	uint16_t qtype);
+	int reclame, uint16_t qtype);
 
 /**
  * Update rtt information for the host.
@@ -262,6 +267,7 @@ int infra_edns_update(struct infra_cache* infra,
  * @param lame: if function returns true, this returns lameness of the zone.
  * @param dnsseclame: if function returns true, this returns if the zone
  *	is dnssec-lame.
+ * @param reclame: if function returns true, this is if it is recursion lame.
  * @param rtt: if function returns true, this returns avg rtt of the server.
  * 	The rtt value is unclamped and reflects recent timeouts.
  * @param timenow: what time it is now.
@@ -270,7 +276,7 @@ int infra_edns_update(struct infra_cache* infra,
 int infra_get_lame_rtt(struct infra_cache* infra,
         struct sockaddr_storage* addr, socklen_t addrlen, 
 	uint8_t* name, size_t namelen, uint16_t qtype, 
-	int* lame, int* dnsseclame, int* rtt, uint32_t timenow);
+	int* lame, int* dnsseclame, int* reclame, int* rtt, uint32_t timenow);
 
 /**
  * Get memory used by the infra cache.

services/outside_network.c

@@ -1688,3 +1688,4 @@ serviced_get_mem(struct serviced_query* sq)
 	}
 	return s;
 }
+

testcode/unitmain.c

@@ -320,7 +320,7 @@ infra_test()
 	struct infra_host_key* k;
 	struct infra_host_data* d;
 	int init = 376;
-	int dlame, alame, olame;
+	int dlame, rlame, alame, olame;
 
 	slab = infra_create(cfg);
 	unit_assert( infra_host(slab, (struct sockaddr_storage*)&one, 
@@ -345,30 +345,30 @@ infra_test()
 	unit_assert( vs == 0 && to == init && edns_lame == 0 );
 	
 	unit_assert( infra_set_lame(slab, (struct sockaddr_storage*)&one, 
-		(socklen_t)sizeof(int), zone, zonelen,  now, 0, 
+		(socklen_t)sizeof(int), zone, zonelen,  now, 0, 0,
 		LDNS_RR_TYPE_A) );
 	unit_assert( (d=infra_lookup_host(slab, (struct sockaddr_storage*)&one,
 		(socklen_t)sizeof(int), 0, now, &k)) );
 	unit_assert( d->ttl == now+cfg->host_ttl );
 	unit_assert( d->edns_version == 0 );
 	unit_assert( infra_lookup_lame(d, zone, zonelen, now, 
-		&dlame, &alame, &olame) );
+		&dlame, &rlame, &alame, &olame) );
-	unit_assert(!dlame && alame && !olame);
+	unit_assert(!dlame && !rlame && alame && !olame);
 	unit_assert( !infra_lookup_lame(d, zone, zonelen, 
-		now+cfg->lame_ttl+10, &dlame, &alame, &olame) );
+		now+cfg->lame_ttl+10, &dlame, &rlame, &alame, &olame) );
 	unit_assert( !infra_lookup_lame(d, (uint8_t*)"\000", 1, now, 
-		&dlame, &alame, &olame) );
+		&dlame, &rlame, &alame, &olame) );
 	lock_rw_unlock(&k->entry.lock);
 
 	/* test merge of data */
 	unit_assert( infra_set_lame(slab, (struct sockaddr_storage*)&one, 
-		(socklen_t)sizeof(int), zone, zonelen,  now, 0, 
+		(socklen_t)sizeof(int), zone, zonelen,  now, 0, 0,
 		LDNS_RR_TYPE_AAAA) );
 	unit_assert( (d=infra_lookup_host(slab, (struct sockaddr_storage*)&one,
 		(socklen_t)sizeof(int), 0, now, &k)) );
 	unit_assert( infra_lookup_lame(d, zone, zonelen, now, 
-		&dlame, &alame, &olame) );
+		&dlame, &rlame, &alame, &olame) );
-	unit_assert(!dlame && alame && olame);
+	unit_assert(!dlame && !rlame && alame && olame);
 	lock_rw_unlock(&k->entry.lock);
 
 	infra_delete(slab);

testdata/iter_reclame_one.rpl

@@ -0,0 +1,162 @@
+; config options
+stub-zone:
+	name: "."
+	stub-addr: 193.0.14.129 	# K.ROOT-SERVERS.NET.
+CONFIG_END
+
+SCENARIO_BEGIN Test iterative resolve with a recursion lame server.
+; The scenario has a domain with two servers, one is lame the other doesn't
+; so depending on the randomly chosen server that goes first, it may
+; select the nonlame or the lame server first.
+
+; K.ROOT-SERVERS.NET.
+RANGE_BEGIN 0 100
+	ADDRESS 193.0.14.129 
+ENTRY_BEGIN
+MATCH opcode qtype qname
+ADJUST copy_id
+REPLY QR NOERROR
+SECTION QUESTION
+. IN NS
+SECTION ANSWER
+. IN NS	K.ROOT-SERVERS.NET.
+SECTION ADDITIONAL
+K.ROOT-SERVERS.NET.	IN	A	193.0.14.129
+ENTRY_END
+
+ENTRY_BEGIN
+MATCH opcode qtype qname
+ADJUST copy_id
+REPLY QR NOERROR
+SECTION QUESTION
+www.example.com. IN A
+SECTION AUTHORITY
+com.	IN NS	a.gtld-servers.net.
+SECTION ADDITIONAL
+a.gtld-servers.net.	IN 	A	192.5.6.30
+ENTRY_END
+RANGE_END
+
+; a.gtld-servers.net.
+RANGE_BEGIN 0 100
+	ADDRESS 192.5.6.30
+ENTRY_BEGIN
+MATCH opcode qtype qname
+ADJUST copy_id
+REPLY QR NOERROR
+SECTION QUESTION
+com. IN NS
+SECTION ANSWER
+com.	IN NS	a.gtld-servers.net.
+SECTION ADDITIONAL
+a.gtld-servers.net.	IN 	A	192.5.6.30
+ENTRY_END
+
+ENTRY_BEGIN
+MATCH opcode qtype qname
+ADJUST copy_id
+REPLY QR NOERROR
+SECTION QUESTION
+www.example.com. IN A
+SECTION AUTHORITY
+example.com.	IN NS	ns.example.com.
+example.com.	IN NS	lame.example.com.
+SECTION ADDITIONAL
+ns.example.com.		IN 	A	1.2.3.4
+lame.example.com.		IN 	A	1.2.3.5
+ENTRY_END
+RANGE_END
+
+; ns.example.com.
+RANGE_BEGIN 0 100
+	ADDRESS 1.2.3.4
+ENTRY_BEGIN
+MATCH opcode qtype qname
+ADJUST copy_id
+REPLY QR AA NOERROR
+SECTION QUESTION
+example.com. IN NS
+SECTION ANSWER
+example.com.	IN NS	ns.example.com.
+example.com.	IN NS	lame.example.com.
+SECTION ADDITIONAL
+ns.example.com.		IN 	A	1.2.3.4
+lame.example.com.		IN 	A	1.2.3.5
+ENTRY_END
+
+ENTRY_BEGIN
+MATCH opcode qtype qname
+ADJUST copy_id
+REPLY QR AA NOERROR
+SECTION QUESTION
+www.example.com. IN A
+SECTION ANSWER
+www.example.com. IN A	10.20.30.40
+SECTION AUTHORITY
+example.com.	IN NS	ns.example.com.
+example.com.	IN NS	lame.example.com.
+SECTION ADDITIONAL
+ns.example.com.		IN 	A	1.2.3.4
+lame.example.com.		IN 	A	1.2.3.5
+ENTRY_END
+RANGE_END
+
+; lame.example.com.
+RANGE_BEGIN 0 100
+	ADDRESS 1.2.3.5
+ENTRY_BEGIN
+MATCH opcode qtype qname
+ADJUST copy_id
+REPLY QR RA NOERROR
+SECTION QUESTION
+example.com. IN NS
+SECTION ANSWER
+example.com.	IN NS	ns.example.com.
+example.com.	IN NS	lame.example.com.
+SECTION ADDITIONAL
+ns.example.com.		IN 	A	1.2.3.4
+lame.example.com.		IN 	A	1.2.3.5
+ENTRY_END
+
+ENTRY_BEGIN
+MATCH opcode qtype qname
+ADJUST copy_id
+REPLY QR RA NOERROR
+SECTION QUESTION
+www.example.com. IN A
+SECTION ANSWER
+www.example.com. IN A	10.20.30.40
+SECTION AUTHORITY
+example.com.	IN NS	ns.example.com.
+example.com.	IN NS	lame.example.com.
+SECTION ADDITIONAL
+ns.example.com.		IN 	A	1.2.3.4
+lame.example.com.		IN 	A	1.2.3.5
+ENTRY_END
+RANGE_END
+
+STEP 1 QUERY
+ENTRY_BEGIN
+REPLY RD
+SECTION QUESTION
+www.example.com. IN A
+ENTRY_END
+
+; recursion happens here.
+STEP 10 CHECK_ANSWER
+ENTRY_BEGIN
+MATCH all
+REPLY QR RD RA NOERROR
+SECTION QUESTION
+www.example.com. IN A
+SECTION ANSWER
+www.example.com. IN A	10.20.30.40
+SECTION AUTHORITY
+example.com.	IN NS	ns.example.com.
+example.com.	IN NS	lame.example.com.
+SECTION ADDITIONAL
+ns.example.com.		IN 	A	1.2.3.4
+lame.example.com.		IN 	A	1.2.3.5
+ENTRY_END
+
+SCENARIO_END

testdata/iter_reclame_two.rpl

@@ -0,0 +1,161 @@
+; config options
+stub-zone:
+	name: "."
+	stub-addr: 193.0.14.129 	# K.ROOT-SERVERS.NET.
+CONFIG_END
+
+SCENARIO_BEGIN Test iterative resolve with two recursion lame servers.
+; both servers are recursion lame. The iterator tries both servers,
+; but they are both lame.  Then it concludes that it only has reclame.
+
+; K.ROOT-SERVERS.NET.
+RANGE_BEGIN 0 100
+	ADDRESS 193.0.14.129 
+ENTRY_BEGIN
+MATCH opcode qtype qname
+ADJUST copy_id
+REPLY QR NOERROR
+SECTION QUESTION
+. IN NS
+SECTION ANSWER
+. IN NS	K.ROOT-SERVERS.NET.
+SECTION ADDITIONAL
+K.ROOT-SERVERS.NET.	IN	A	193.0.14.129
+ENTRY_END
+
+ENTRY_BEGIN
+MATCH opcode qtype qname
+ADJUST copy_id
+REPLY QR NOERROR
+SECTION QUESTION
+www.example.com. IN A
+SECTION AUTHORITY
+com.	IN NS	a.gtld-servers.net.
+SECTION ADDITIONAL
+a.gtld-servers.net.	IN 	A	192.5.6.30
+ENTRY_END
+RANGE_END
+
+; a.gtld-servers.net.
+RANGE_BEGIN 0 100
+	ADDRESS 192.5.6.30
+ENTRY_BEGIN
+MATCH opcode qtype qname
+ADJUST copy_id
+REPLY QR NOERROR
+SECTION QUESTION
+com. IN NS
+SECTION ANSWER
+com.	IN NS	a.gtld-servers.net.
+SECTION ADDITIONAL
+a.gtld-servers.net.	IN 	A	192.5.6.30
+ENTRY_END
+
+ENTRY_BEGIN
+MATCH opcode qtype qname
+ADJUST copy_id
+REPLY QR NOERROR
+SECTION QUESTION
+www.example.com. IN A
+SECTION AUTHORITY
+example.com.	IN NS	ns.example.com.
+example.com.	IN NS	lame.example.com.
+SECTION ADDITIONAL
+ns.example.com.		IN 	A	1.2.3.4
+lame.example.com.		IN 	A	1.2.3.5
+ENTRY_END
+RANGE_END
+
+; ns.example.com.
+RANGE_BEGIN 0 100
+	ADDRESS 1.2.3.4
+ENTRY_BEGIN
+MATCH opcode qtype qname
+ADJUST copy_id
+REPLY QR RA NOERROR
+SECTION QUESTION
+example.com. IN NS
+SECTION ANSWER
+example.com.	IN NS	ns.example.com.
+example.com.	IN NS	lame.example.com.
+SECTION ADDITIONAL
+ns.example.com.		IN 	A	1.2.3.4
+lame.example.com.		IN 	A	1.2.3.5
+ENTRY_END
+
+ENTRY_BEGIN
+MATCH opcode qtype qname
+ADJUST copy_id
+REPLY QR RA NOERROR
+SECTION QUESTION
+www.example.com. IN A
+SECTION ANSWER
+www.example.com. IN A	10.20.30.40
+SECTION AUTHORITY
+example.com.	IN NS	ns.example.com.
+example.com.	IN NS	lame.example.com.
+SECTION ADDITIONAL
+ns.example.com.		IN 	A	1.2.3.4
+lame.example.com.		IN 	A	1.2.3.5
+ENTRY_END
+RANGE_END
+
+; lame.example.com.
+RANGE_BEGIN 0 100
+	ADDRESS 1.2.3.5
+ENTRY_BEGIN
+MATCH opcode qtype qname
+ADJUST copy_id
+REPLY QR RA NOERROR
+SECTION QUESTION
+example.com. IN NS
+SECTION ANSWER
+example.com.	IN NS	ns.example.com.
+example.com.	IN NS	lame.example.com.
+SECTION ADDITIONAL
+ns.example.com.		IN 	A	1.2.3.4
+lame.example.com.		IN 	A	1.2.3.5
+ENTRY_END
+
+ENTRY_BEGIN
+MATCH opcode qtype qname
+ADJUST copy_id
+REPLY QR RA NOERROR
+SECTION QUESTION
+www.example.com. IN A
+SECTION ANSWER
+www.example.com. IN A	10.20.30.40
+SECTION AUTHORITY
+example.com.	IN NS	ns.example.com.
+example.com.	IN NS	lame.example.com.
+SECTION ADDITIONAL
+ns.example.com.		IN 	A	1.2.3.4
+lame.example.com.		IN 	A	1.2.3.5
+ENTRY_END
+RANGE_END
+
+STEP 1 QUERY
+ENTRY_BEGIN
+REPLY RD
+SECTION QUESTION
+www.example.com. IN A
+ENTRY_END
+
+; recursion happens here.
+STEP 10 CHECK_ANSWER
+ENTRY_BEGIN
+MATCH all
+REPLY QR RD RA NOERROR
+SECTION QUESTION
+www.example.com. IN A
+SECTION ANSWER
+www.example.com. IN A	10.20.30.40
+SECTION AUTHORITY
+example.com.	IN NS	ns.example.com.
+example.com.	IN NS	lame.example.com.
+SECTION ADDITIONAL
+ns.example.com.		IN 	A	1.2.3.4
+lame.example.com.		IN 	A	1.2.3.5
+ENTRY_END
+
+SCENARIO_END