iterator work.

git-svn-id: file:///svn/unbound/trunk@348 be551aaa-1e26-0410-a405-d3ace91eadb9

daemon/worker.c

@@ -97,6 +97,8 @@ qstate_free(struct worker* worker, struct module_qstate* qstate)
 	if(qstate->parent) {
 		module_subreq_remove(qstate);
 		free(qstate);
+	} else {
+		region_destroy(qstate->region);
 	}
 }
 
@@ -159,40 +161,66 @@ replyerror(int r, struct work_query* w)
 	query_info_clear(&w->state.qinfo);
 }
 
+/** init qstate module states */
+static void
+set_extstates_initial(struct worker* worker, struct module_qstate* qstate)
+{
+	int i;
+	for(i=0; i<worker->daemon->num_modules; i++)
+		qstate->ext_state[i] = module_state_initial;
+}
+
 /** process incoming request */
 static void 
 worker_process_query(struct worker* worker, struct work_query* w, 
 	struct module_qstate* qstate, enum module_ev event, 
 	struct outbound_entry* entry) 
 {
-	int i;
 	enum module_ext_state s;
 	if(event == module_event_new) {
 		qstate->curmod = 0;
-		for(i=0; i<worker->daemon->num_modules; i++)
+		set_extstates_initial(worker, qstate);
-			qstate->ext_state[i] = module_state_initial;
 	}
 	/* allow current module to run */
-	(*worker->daemon->modfunc[qstate->curmod]->operate)(qstate, event,
+	/* loops for subqueries or parent queries. */
-		qstate->curmod, entry);
+	while(1) {
-	s = qstate->ext_state[qstate->curmod];
+		(*worker->daemon->modfunc[qstate->curmod]->operate)(qstate, 
-	/* TODO examine results, start further modules, etc.
+			event, qstate->curmod, entry);
-	 * assume it went to sleep
+		region_free_all(worker->scratchpad);
-	 */
+		s = qstate->ext_state[qstate->curmod];
-	region_free_all(worker->scratchpad);
+		/* examine results, start further modules, etc. */
-	/* subrequest done */
+		if(s == module_wait_subquery) {
-	/* TODO properly delete subquery */
+			if(!qstate->subquery_first) {
-	if(s == module_error && qstate->parent) {
+				log_err("module exit wait subq, but no subq");
-		qstate_free(worker, qstate);
+				s = module_error;
-		worker_process_query(worker, w, qstate->parent, 
+			} else {
-			module_event_error, NULL);
+				/* start submodule */
-		return;
+				qstate = qstate->subquery_first;
-	}
+				set_extstates_initial(worker, qstate);
-	if(s == module_finished && qstate->parent) {
+				event = module_event_pass;
-		qstate_free(worker, qstate);
+				entry = NULL;
-		worker_process_query(worker, w, qstate->parent, 
+				continue;
-			module_event_subq_done, NULL);
+			}
-		return;
+		}
+
+		/* subrequest done */
+		if(s == module_error && qstate->parent) {
+			struct module_qstate* up = qstate->parent;
+			qstate_free(worker, qstate);
+			qstate = up;
+			entry = NULL;
+			event = module_event_error;
+			continue;
+		}
+		if(s == module_finished && qstate->parent) {
+			struct module_qstate* up = qstate->parent;
+			qstate_free(worker, qstate);
+			qstate = up;
+			entry = NULL;
+			event = module_event_subq_done;
+			continue;
+		}
+		break;
 	}
 	/* request done */
 	if(s == module_error) {

doc/Changelog

@@ -2,6 +2,10 @@
 	- removed FLAG_CD from message and rrset caches. This was useful for
 	  an agnostic forwarder, but not for a sophisticated (trust value per
 	  rrset enabled) cache.
+	- iterator reponse typing.
+	- iterator cname handle.
+	- iterator prime start.
+	- subquery work.
 
 29 May 2007: Wouter
 	- routines to lock and unlock array of rrsets moved to cache/rrset.

iterator/iter_resptype.c

@@ -0,0 +1,99 @@
+/*
+ * iterator/iter_resptype.c - response type information and classification.
+ *
+ * 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 defines the response type. DNS Responses can be classified as
+ * one of the response types.
+ */
+#include "config.h"
+#include "iterator/iter_resptype.h"
+#include "services/cache/dns.h"
+#include "util/net_help.h"
+#include "util/data/dname.h"
+
+enum response_type 
+response_type_from_cache(struct dns_msg* msg, 
+	struct query_info* request)
+{
+	/* If the message is NXDOMAIN, then it is an ANSWER. */
+	if(FLAGS_GET_RCODE(msg->rep->flags) == LDNS_RCODE_NXDOMAIN)
+		return RESPONSE_TYPE_ANSWER;
+	
+	/* First we look at the answer section. This can tell us if this is
+	 * CNAME or positive ANSWER. */
+	if(msg->rep->an_numrrsets > 0) {
+		/* Now look at the answer section first. 3 states: 
+		 *	o our answer is there directly,
+		 *	o our answer is there after a cname,
+		 *	o or there is just a cname. */
+		uint8_t* mname = request->qname;
+		size_t mname_len = request->qname_len;
+		size_t i;
+		for(i=0; i<msg->rep->an_numrrsets; i++) {
+			struct ub_packed_rrset_key* s = msg->rep->rrsets[i];
+
+			/* If we have encountered an answer (before or 
+			 * after a CNAME), then we are done! Note that 
+			 * if qtype == CNAME then this will be noted as 
+			 * an ANSWER before it gets treated as a CNAME, 
+			 * as it should */
+			if(ntohs(s->rk.type) == request->qtype &&
+				ntohs(s->rk.rrset_class) == request->qclass &&
+				query_dname_compare(mname, s->rk.dname) == 0) {
+				return RESPONSE_TYPE_ANSWER;
+			}
+
+			/* If we have encountered a CNAME, make sure that 
+			 * it is relevant. */
+			if(ntohs(s->rk.type) == LDNS_RR_TYPE_CNAME &&
+				query_dname_compare(mname, s->rk.dname) == 0) {
+				get_cname_target(s, &mname, &mname_len);
+			}
+		}
+
+		/* if we encountered a CNAME (or a bunch of CNAMEs), and 
+		 * still got to here, then it is a CNAME response. (i.e., 
+		 * the CNAME chain didn't terminate in an answer rrset.) */
+		if(mname != request->qname) {
+			return RESPONSE_TYPE_CNAME;
+		}
+	}
+
+	/* At this point, since we don't need to detect REFERRAL or LAME 
+	 * messages, it can only be an ANSWER. */
+	return RESPONSE_TYPE_ANSWER;
+}

iterator/iter_resptype.h

@@ -0,0 +1,100 @@
+/*
+ * iterator/iter_resptype.h - response type information and classification.
+ *
+ * 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 defines the response type. DNS Responses can be classified as
+ * one of the response types.
+ */
+
+#ifndef ITERATOR_ITER_RESPTYPE_H
+#define ITERATOR_ITER_RESPTYPE_H
+struct dns_msg;
+struct query_info;
+
+/**
+ * The response type is used to interpret the response.
+ */
+enum response_type {
+	/** 
+	 * 'untyped' means that the type of this response hasn't been 
+	 * assigned. 
+	 */
+	RESPONSE_TYPE_UNTYPED   = 0,
+
+	/** 
+	 * 'answer' means that the response terminates the resolution 
+	 * process. 
+	 */
+	RESPONSE_TYPE_ANSWER,
+
+	/** 'delegation' means that the response is a delegation. */
+	RESPONSE_TYPE_REFERRAL,
+
+	/**
+	 * 'cname' means that the response is a cname without the final 
+	 * answer, and thus must be restarted.
+	 */
+	RESPONSE_TYPE_CNAME,
+
+	/**
+	 * 'throwaway' means that this particular response should be 
+	 * discarded and the next nameserver should be contacted
+	 */
+	RESPONSE_TYPE_THROWAWAY,
+
+	/**
+	 * 'lame' means that this particular response indicates that 
+	 * the nameserver knew nothing about the question.
+	 */
+	RESPONSE_TYPE_LAME
+};
+
+/**
+ * Classifies a response message from cache based on the current request.
+ * Note that this routine assumes that THROWAWAY or LAME responses will not
+ * occur. Also, it will not detect REFERRAL type messages, since those are
+ * (currently) automatically classified based on how they came from the
+ * cache (findDelegation() instead of lookup()).
+ *
+ * @param msg: the message from the cache.
+ * @param request: the request that generated the response.
+ * @return the response type (CNAME or ANSWER).
+ */
+enum response_type response_type_from_cache(struct dns_msg* msg, 
+	struct query_info* request);
+
+#endif /* ITERATOR_ITER_RESPTYPE_H */

iterator/iterator.c

@@ -44,11 +44,13 @@
 #include "iterator/iterator.h"
 #include "iterator/iter_utils.h"
 #include "iterator/iter_hints.h"
+#include "iterator/iter_resptype.h"
 #include "services/cache/dns.h"
 #include "util/module.h"
 #include "util/netevent.h"
 #include "util/net_help.h"
 #include "util/region-allocator.h"
+#include "util/data/dname.h"
 
 /** iterator init */
 static int 
@@ -254,6 +256,7 @@ error_response(struct module_qstate* qstate, struct iter_qstate* iq, int rcode)
 	return final_state(qstate, iq);
 }
 
+#if 0
 /** prepend the prepend list in the answer section of dns_msg */
 static int
 iter_prepend(struct iter_qstate* iq, struct dns_msg* msg, 
@@ -324,6 +327,32 @@ iter_encode_respmsg(struct module_qstate* qstate, struct iter_qstate* iq,
 		return;
 	}
 }
+#endif
+
+/**
+ * Add rrset to prepend list
+ * @param qstate: query state.
+ * @param iq: iterator query state.
+ * @param rrset: rrset to add.
+ * @return false on failure (malloc).
+ */
+static int
+iter_add_prepend(struct module_qstate* qstate, struct iter_qstate* iq,
+	struct ub_packed_rrset_key* rrset)
+{
+	struct iter_prep_list* p = (struct iter_prep_list*)region_alloc(
+		qstate->region, sizeof(struct iter_prep_list));
+	if(!p)
+		return 0;
+	p->rrset = rrset;
+	p->next = NULL;
+	/* add at end */
+	if(iq->prepend_last)
+		iq->prepend_last->next = p;
+	else	iq->prepend_list = p;
+	iq->prepend_last = p;
+	return 1;
+}
 
 /**
  * Given a CNAME response (defined as a response containing a CNAME or DNAME
@@ -334,15 +363,174 @@ iter_encode_respmsg(struct module_qstate* qstate, struct iter_qstate* iq,
  * sets the new query name, after following the CNAME/DNAME chain.
  * @param qstate: query state.
  * @param iq: iterator query state.
- * @param ie: iterator shared global environment.
+ * @param msg: the response.
+ * @param mname: returned target new query name.
+ * @param mname_len: length of mname.
+ * @return false on (malloc) error.
  */
-static void
+static int
 handle_cname_response(struct module_qstate* qstate, struct iter_qstate* iq,
-        struct iter_env* ie)
+        struct dns_msg* msg, uint8_t** mname, size_t* mname_len)
 {
+	size_t i;
+	/* Start with the (current) qname. */
+	*mname = qstate->qinfo.qname;
+	*mname_len = qstate->qinfo.qname_len;
 
+	/* Iterate over the ANSWER rrsets in order, looking for CNAMEs and 
+	 * DNAMES. */
+	for(i=0; i<msg->rep->an_numrrsets; i++) {
+		struct ub_packed_rrset_key* r = msg->rep->rrsets[i];
+		/* If there is a (relevant) DNAME, add it to the list.
+		 * We always expect there to be CNAME that was generated 
+		 * by this DNAME following, so we don't process the DNAME 
+		 * directly.  */
+		if(ntohs(r->rk.type) == LDNS_RR_TYPE_DNAME &&
+			dname_strict_subdomain_c(*mname, r->rk.dname)) {
+			if(!iter_add_prepend(qstate, iq, r))
+				return 0;
+			continue;
+		}
+
+		if(ntohs(r->rk.type) == LDNS_RR_TYPE_CNAME &&
+			query_dname_compare(*mname, r->rk.dname) == 0) {
+			/* Add this relevant CNAME rrset to the prepend list.*/
+			if(!iter_add_prepend(qstate, iq, r))
+				return 0;
+			get_cname_target(r, mname, mname_len);
+		}
+
+		/* Other rrsets in the section are ignored. */
+	}
+	return 1;
 }
 
+/**
+ * Generate a subrequest.
+ * Generate a local request event. Local events are tied to this module, and
+ * have a correponding (first tier) event that is waiting for this event to
+ * resolve to continue.
+ *
+ * @param qname The query name for this request.
+ * @param qnamelen length of qname
+ * @param qtype The query type for this request.
+ * @param qclass The query class for this request.
+ * @param qstate The event that is generating this event.
+ * @param id: module id.
+ * @param initial_state The initial response state (normally this
+ *          is QUERY_RESP_STATE, unless it is known that the request won't
+ *          need iterative processing
+ * @param final_state The final state for the response to this
+ *          request.
+ * @return generated subquerystate, or NULL on error (malloc).
+ */
+static struct module_qstate* 
+generate_sub_request(uint8_t* qname, size_t qnamelen, uint16_t qtype, 
+	uint16_t qclass, struct module_qstate* qstate, int id,
+	enum iter_state initial_state, enum iter_state final_state)
+{
+	struct module_qstate* subq = (struct module_qstate*)malloc(
+		sizeof(struct module_qstate));
+	struct iter_qstate* subiq;
+	if(!subq)
+		return NULL;
+	memset(subq, 0, sizeof(*subq));
+	subq->qinfo.qname = memdup(qname, qnamelen);
+	if(!subq->qinfo.qname) {
+		free(subq);
+		return NULL;
+	}
+	subq->qinfo.qname_len = qnamelen;
+	subq->qinfo.qtype = qtype;
+	subq->qinfo.qclass = qclass;
+	subq->query_hash = query_info_hash(&subq->qinfo);
+	subq->query_flags = 0; /* OPCODE QUERY, no flags */
+	subq->edns.udp_size = 65535;
+	subq->buf = qstate->buf;
+	subq->scratch = qstate->scratch;
+	subq->region = region_create(malloc, free);
+	if(!subq->region) {
+		free(subq->qinfo.qname);
+		free(subq);
+		return NULL;
+	}
+	subq->curmod = id;
+	subq->ext_state[id] = module_state_initial;
+	subq->minfo[id] = region_alloc(subq->region, 
+		sizeof(struct iter_qstate));
+	if(!subq->minfo[id]) {
+		region_destroy(subq->region);
+		free(subq->qinfo.qname);
+		free(subq);
+		return NULL;
+	}
+	subq->env = qstate->env;
+	subq->work_info = qstate->work_info;
+	subq->parent = qstate;
+	subq->subquery_next = qstate->subquery_first;
+	qstate->subquery_first = subq;
+
+	subiq = (struct iter_qstate*)subq->minfo[id];
+	memset(subiq, 0, sizeof(*subiq));
+	subiq->num_target_queries = -1; /* default our targetQueries counter. */
+	outbound_list_init(&subiq->outlist);
+	subiq->state = initial_state;
+	subiq->final_state = final_state;
+
+	/* RD should be set only when sending the query back through the INIT
+	 * state. */
+	if(initial_state == INIT_REQUEST_STATE)
+		subq->query_flags |= BIT_RD;
+	/* We set the CD flag so we can send this through the "head" of 
+	 * the resolution chain, which might have a validator. We are 
+	 * uninterested in validating things not on the direct resolution 
+	 * path.  */
+	subq->query_flags |= BIT_CD;
+	
+	return subq;
+}
+
+/**
+ * Generate and send a root priming request.
+ * @param qstate: the qtstate that triggered the need to prime.
+ * @param ie: iterator global state.
+ * @param id: module id.
+ * @param qclass: the class to prime.
+ */
+static int
+prime_root(struct module_qstate* qstate, struct iter_env* ie, int id, 
+	uint16_t qclass)
+{
+	struct delegpt* dp;
+	struct module_qstate* subq;
+	struct iter_qstate* subiq;
+	verbose(VERB_ALGO, "priming <./%s>", 
+		ldns_lookup_by_id(ldns_rr_classes, (int)qclass)?
+		ldns_lookup_by_id(ldns_rr_classes, (int)qclass)->name:"??");
+	dp = hints_lookup_root(ie->hints, qclass);
+	if(!dp) {
+		verbose(VERB_ALGO, "Cannot prime due to lack of hints");
+		return 0;
+	}
+	/* Priming requests start at the QUERYTARGETS state, skipping 
+	 * the normal INIT state logic (which would cause an infloop). */
+	subq = generate_sub_request((uint8_t*)"\000", 1, LDNS_RR_TYPE_NS, 
+		qclass, qstate, id, QUERYTARGETS_STATE, PRIME_RESP_STATE);
+	if(!subq) {
+		log_err("out of memory priming root");
+		return 0;
+	}
+	subiq = (struct iter_qstate*)subq->minfo[id];
+
+	/* Set the initial delegation point to the hint. */
+	subiq->dp = dp;
+	/* suppress any target queries. */
+	subiq->num_target_queries = 0; 
+	
+	/* this module stops, our submodule starts, and does the query. */
+	qstate->ext_state[id] = module_wait_subquery;
+	return 1;
+}
 
 /** 
  * Process the initial part of the request handling. This state roughly
@@ -358,12 +546,13 @@ handle_cname_response(struct module_qstate* qstate, struct iter_qstate* iq,
  * @param qstate: query state.
  * @param iq: iterator query state.
  * @param ie: iterator shared global environment.
+ * @param id: module id.
  * @return true if the event needs more request processing immediately,
  *         false if not.
  */
 static int
 processInitRequest(struct module_qstate* qstate, struct iter_qstate* iq,
-	struct iter_env* ie)
+	struct iter_env* ie, int id)
 {
 	int d;
 	uint8_t* delname;
@@ -404,14 +593,25 @@ processInitRequest(struct module_qstate* qstate, struct iter_qstate* iq,
 		qstate->qinfo.qclass, qstate->region, qstate->scratch);
 	if(msg) {
 		/* handle positive cache response */
-		/*
+		enum response_type type = response_type_from_cache(msg, 
-		enum response_type type = type_cache_response(msg);
+			&qstate->qinfo);
 
-		if(type == RESPONSE_TYPE_CNAME) */ {
+		if(type == RESPONSE_TYPE_CNAME) {
+			uint8_t* sname = 0;
+			size_t slen = 0;
 			verbose(VERB_ALGO, "returning CNAME response from "
 				"cache");
-			/* handleCnameresponse  &iq->orig_qname, &iq->orig_qname_len */
+			if(!iq->orig_qname) {
-			/* his *is* a query restart, even if it is a cheap 
+				iq->orig_qname = qstate->qinfo.qname;
+				iq->orig_qnamelen = qstate->qinfo.qname_len;
+			}
+			if(!handle_cname_response(qstate, iq, msg, 
+				&sname, &slen))
+				return error_response(qstate, iq,
+					LDNS_RCODE_SERVFAIL);
+			qstate->qinfo.qname = sname;
+			qstate->qinfo.qname_len = slen;
+			/* This *is* a query restart, even if it is a cheap 
 			 * one. */
 			iq->query_restart_count++;
 			return next_state(qstate, iq, INIT_REQUEST_STATE);
@@ -419,13 +619,39 @@ processInitRequest(struct module_qstate* qstate, struct iter_qstate* iq,
 
 		/* it is an answer, response, to final state */
 		verbose(VERB_ALGO, "returning answer from cache.");
-		iter_encode_respmsg(qstate, iq, msg);
+		iq->response = msg;
 		return final_state(qstate, iq);
 	}
 	
 	/* TODO attempt to forward the request */
+	/* if (forwardRequest(event, state, req))
+	   {
+		// the request has been forwarded.
+		// forwarded requests need to be immediately sent to the 
+		// next state, QUERYTARGETS.
+		return nextState(event, req, state, 
+			IterEventState.QUERYTARGETS_STATE);
+		}
+	*/
 
 	/* TODO attempt to find a covering DNAME in the cache */
+	/* resp = mDNSCache.findDNAME(req.getQName(), req.getQType(), req
+	        .getQClass());
+	    if (resp != null)
+	{
+log.trace("returning synthesized CNAME response from cache: " + resp);
+Name cname = handleCNAMEResponse(state, req, resp);
+// At this point, we just initiate the query restart.
+// This might not be a query restart situation (e.g., qtype == CNAME),
+// but
+// the answer returned from findDNAME() is likely to be one that we
+// don't want to return.
+// Thus we allow the cache and other resolution mojo kick in regardless.
+req.setQName(cname);
+state.queryRestartCount++;
+return nextState(event, req, state, IterEventState.INIT_REQUEST_STATE);
+}
+	*/
 
 	/* Resolver Algorithm Step 2 -- find the "best" servers. */
 
@@ -435,7 +661,7 @@ processInitRequest(struct module_qstate* qstate, struct iter_qstate* iq,
 	delname = qstate->qinfo.qname;
 	delnamelen = qstate->qinfo.qname_len;
 	if(qstate->qinfo.qtype == LDNS_RR_TYPE_DS && delname[0] != 0) {
-		/* do not adjust root label */
+		/* do not adjust root label, remove first label from delname */
 		size_t lablen = delname[0] + 1;
 		delname += lablen;
 		delnamelen -= lablen;
@@ -451,11 +677,8 @@ processInitRequest(struct module_qstate* qstate, struct iter_qstate* iq,
 	if(iq->dp == NULL) {
 		/* Note that the result of this will set a new
 		 * DelegationPoint based on the result of priming. */
-
+		if(!prime_root(qstate, ie, id, qstate->qinfo.qclass))
-		 /* TODO
+			return error_response(qstate, iq, LDNS_RCODE_REFUSED);
-		if(!prime_root(qstate, iq, ie, qstate->qinfo.qclass))
-			return error_response(qstate, iq, LDNS_RCODE_SERVFAIL);
-			*/
 
 		/* priming creates an sends a subordinate query, with 
 		 * this query as the parent. So further processing for 
@@ -480,7 +703,7 @@ processInitRequest(struct module_qstate* qstate, struct iter_qstate* iq,
 /** TODO */
 static int
 processInitRequest2(struct module_qstate* qstate, struct iter_qstate* iq,
-	struct iter_env* ie)
+	struct iter_env* ie, int id)
 {
 	return 0;
 }
@@ -488,7 +711,7 @@ processInitRequest2(struct module_qstate* qstate, struct iter_qstate* iq,
 /** TODO */
 static int
 processInitRequest3(struct module_qstate* qstate, struct iter_qstate* iq,
-	struct iter_env* ie)
+	struct iter_env* ie, int id)
 {
 	return 0;
 }
@@ -496,7 +719,7 @@ processInitRequest3(struct module_qstate* qstate, struct iter_qstate* iq,
 /** TODO */
 static int
 processQueryTargets(struct module_qstate* qstate, struct iter_qstate* iq,
-	struct iter_env* ie)
+	struct iter_env* ie, int id)
 {
 	return 0;
 }
@@ -504,7 +727,7 @@ processQueryTargets(struct module_qstate* qstate, struct iter_qstate* iq,
 /** TODO */
 static int
 processQueryResponse(struct module_qstate* qstate, struct iter_qstate* iq,
-	struct iter_env* ie)
+	struct iter_env* ie, int id)
 {
 	return 0;
 }
@@ -512,7 +735,7 @@ processQueryResponse(struct module_qstate* qstate, struct iter_qstate* iq,
 /** TODO */
 static int
 processPrimeResponse(struct module_qstate* qstate, struct iter_qstate* iq,
-	struct iter_env* ie)
+	struct iter_env* ie, int id)
 {
 	return 0;
 }
@@ -520,7 +743,7 @@ processPrimeResponse(struct module_qstate* qstate, struct iter_qstate* iq,
 /** TODO */
 static int
 processTargetResponse(struct module_qstate* qstate, struct iter_qstate* iq,
-	struct iter_env* ie)
+	struct iter_env* ie, int id)
 {
 	return 0;
 }
@@ -528,7 +751,7 @@ processTargetResponse(struct module_qstate* qstate, struct iter_qstate* iq,
 /** TODO */
 static int
 processFinished(struct module_qstate* qstate, struct iter_qstate* iq,
-	struct iter_env* ie)
+	struct iter_env* ie, int id)
 {
 	return 0;
 }
@@ -544,10 +767,11 @@ processFinished(struct module_qstate* qstate, struct iter_qstate* iq,
  * @param qstate: query state.
  * @param ie: iterator shared global environment.
  * @param iq: iterator query state.
+ * @param id: module id.
  */
 static void
 iter_handle(struct module_qstate* qstate, struct iter_qstate* iq,
-	struct iter_env* ie)
+	struct iter_env* ie, int id)
 {
 	int cont = 1;
 	while(cont) {
@@ -555,29 +779,29 @@ iter_handle(struct module_qstate* qstate, struct iter_qstate* iq,
 			iter_state_to_string(iq->state));
 		switch(iq->state) {
 			case INIT_REQUEST_STATE:
-				cont = processInitRequest(qstate, iq, ie);
+				cont = processInitRequest(qstate, iq, ie, id);
 				break;
 #if 0
 			case INIT_REQUEST_2_STATE:
-				cont = processInitRequest2(qstate, iq, ie);
+				cont = processInitRequest2(qstate, iq, ie, id);
 				break;
 			case INIT_REQUEST_3_STATE:
-				cont = processInitRequest3(qstate, iq, ie);
+				cont = processInitRequest3(qstate, iq, ie, id);
 				break;
 			case QUERYTARGETS_STATE:
-				cont = processQueryTargets(qstate, iq, ie);
+				cont = processQueryTargets(qstate, iq, ie, id);
 				break;
 			case QUERY_RESP_STATE:
-				cont = processQueryResponse(qstate, iq, ie);
+				cont = processQueryResponse(qstate, iq, ie, id);
 				break;
 			case PRIME_RESP_STATE:
-				cont = processPrimeResponse(qstate, iq, ie);
+				cont = processPrimeResponse(qstate, iq, ie, id);
 				break;
 			case TARGET_RESP_STATE:
-				cont = processTargetResponse(qstate, iq, ie);
+				cont = processTargetResponse(qstate, iq, ie, id);
 				break;
 			case FINISHED_STATE:
-				cont = processFinished(qstate, iq, ie);
+				cont = processFinished(qstate, iq, ie, id);
 				break;
 #endif
 			default:
@@ -595,28 +819,29 @@ iter_handle(struct module_qstate* qstate, struct iter_qstate* iq,
  * @param qstate: query state.
  * @param ie: iterator shared global environment.
  * @param iq: iterator query state.
+ * @param id: module id.
  */
 static void
 process_request(struct module_qstate* qstate, struct iter_qstate* iq,
-	struct iter_env* ie)
+	struct iter_env* ie, int id)
 {
 	/* external requests start in the INIT state, and finish using the
 	 * FINISHED state. */
 	iq->state = INIT_REQUEST_STATE;
 	iq->final_state = FINISHED_STATE;
 	verbose(VERB_ALGO, "process_request: new external request event");
-	iter_handle(qstate, iq, ie);
+	iter_handle(qstate, iq, ie, id);
 }
 
 /** process authoritative server reply */
 static void
 process_response(struct module_qstate* qstate, struct iter_qstate* iq, 
-	struct iter_env* ie, struct outbound_entry* outbound)
+	struct iter_env* ie, int id, struct outbound_entry* outbound)
 {
 	verbose(VERB_ALGO, "process_response: new external response event");
 	/* TODO outbound: use it for scrubbing and so on */
 	iq->state = QUERY_RESP_STATE;
-	iter_handle(qstate, iq, ie);
+	iter_handle(qstate, iq, ie, id);
 }
 
 /** iterator operate on a query */
@@ -625,7 +850,7 @@ iter_operate(struct module_qstate* qstate, enum module_ev event, int id,
 	struct outbound_entry* outbound)
 {
 	struct iter_env* ie = (struct iter_env*)qstate->env->modinfo[id];
-	struct iter_qstate* iq;
+	struct iter_qstate* iq = (struct iter_qstate*)qstate->minfo[id];
 	verbose(VERB_ALGO, "iterator[module %d] operate: extstate:%s event:%s", 
 		id, strextstate(qstate->ext_state[id]), strmodulevent(event));
 	if(ie->fwd_addrlen != 0) {
@@ -633,19 +858,22 @@ iter_operate(struct module_qstate* qstate, enum module_ev event, int id,
 		return;
 	}
 	/* perform iterator state machine */
-	if(event == module_event_new) {
+	if(event == module_event_new && iq == NULL) {
 		log_info("iter state machine");
 		if(!iter_new(qstate, id)) {
 			qstate->ext_state[id] = module_error;
 			return;
 		}
 		iq = (struct iter_qstate*)qstate->minfo[id];
-		process_request(qstate, iq, ie);
+		process_request(qstate, iq, ie, id);
+		return;
+	}
+	if(event == module_event_pass) {
+		iter_handle(qstate, iq, ie, id);
 		return;
 	}
-	iq = (struct iter_qstate*)qstate->minfo[id];
 	if(event == module_event_reply) {
-		process_response(qstate, iq, ie, outbound);
+		process_response(qstate, iq, ie, id, outbound);
 		return;
 	}
 	/* TODO: uhh */
@@ -662,6 +890,11 @@ iter_clear(struct module_qstate* qstate, int id)
 	if(!qstate)
 		return;
 	iq = (struct iter_qstate*)qstate->minfo[id];
+	if(iq->orig_qname) {
+		/* so the correct qname gets free'd */
+		qstate->qinfo.qname = iq->orig_qname;
+		qstate->qinfo.qname_len = iq->orig_qnamelen;
+	}
 	outbound_list_clear(&iq->outlist);
 	qstate->minfo[id] = NULL;
 }

iterator/iterator.h

@@ -45,8 +45,8 @@
 #include "services/outbound_list.h"
 struct module_func_block;
 struct delegpt;
-struct packed_rrset_list;
 struct iter_hints;
+struct iter_prep_list;
 
 /** max number of query restarts. Determines max number of CNAME chain. */
 #define MAX_RESTART_COUNT       8
@@ -159,13 +159,18 @@ struct iter_qstate {
 	 */
 	enum iter_state final_state;
 
+	/**
+	 * The response
+	 */
+	struct dns_msg* response;
+
 	/** 
 	 * This is a list of RRsets that must be prepended to the 
 	 * ANSWER section of a response before being sent upstream.
 	 */
-	struct packed_rrset_list* prepend_list;
+	struct iter_prep_list* prepend_list;
 	/** Last element of the prepend list */
-	struct packed_rrset_list* prepend_last;
+	struct iter_prep_list* prepend_last;
 
 	/** original query name - if not NULL, malloced and before CNAME */
 	uint8_t* orig_qname;
@@ -209,6 +214,16 @@ struct iter_qstate {
 	struct outbound_list outlist;
 };
 
+/**
+ * List of prepend items
+ */
+struct iter_prep_list {
+	/** next in list */
+	struct iter_prep_list* next;
+	/** rrset */
+	struct ub_packed_rrset_key* rrset;
+};
+
 /**
  * Get the iterator function block.
  * @return: function block with function pointers to iterator methods.

services/cache/dns.c

@@ -44,6 +44,7 @@
 #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/region-allocator.h"
@@ -224,6 +225,9 @@ dns_cache_find_delegation(struct module_env* env, uint8_t* qname,
 	/* add NS entries */
 	for(i=0; i<nsdata->count; i++) {
 		if(nsdata->rr_len[i] < 2+1) continue; /* len + root label */
+		if(dname_valid(nsdata->rr_data[i]+2, nsdata->rr_len[i]-2) != 
+			(size_t)ldns_read_uint16(nsdata->rr_data[i])-2)
+			continue; /* bad format */
 		/* add rdata of NS (= wirefmt dname), skip rdatalen bytes */
 		if(!delegpt_add_ns(dp, region, nsdata->rr_data[i]+2))
 			log_err("find_delegation: addns out of memory");

util/data/dname.c

@@ -68,6 +68,29 @@ query_dname_len(ldns_buffer* query)
 	}
 }
 
+size_t 
+dname_valid(uint8_t* dname, size_t maxlen)
+{
+	size_t len = 0;
+	size_t labellen;
+	labellen = *dname++;
+	while(labellen) {
+		if(labellen&0xc0)
+			return 0; /* no compression ptrs allowed */
+		len += labellen + 1;
+		if(len > LDNS_MAX_DOMAINLEN)
+			return 0; /* too long */
+		if(len > maxlen)
+			return 0; /* does not fit in memory allocation */
+		dname += labellen;
+		labellen = *dname++;
+	}
+	len += 1;
+	if(len > maxlen)
+		return 0; /* does not fit in memory allocation */
+	return len;
+}
+
 int 
 query_dname_compare(uint8_t* d1, uint8_t* d2)
 {
@@ -524,3 +547,9 @@ dname_strict_subdomain(uint8_t* d1, int labs1, uint8_t* d2, int labs2)
 	return 0;
 }
 
+int 
+dname_strict_subdomain_c(uint8_t* d1, uint8_t* d2)
+{
+	return dname_strict_subdomain(d1, dname_count_labels(d1), d2,
+		dname_count_labels(d2));
+}

util/data/dname.h

@@ -54,6 +54,14 @@
  */
 size_t query_dname_len(ldns_buffer* query);
 
+/**
+ * Determine if dname in memory is correct. no compression ptrs allowed.
+ * @param dname: where dname starts in memory.
+ * @param len: dname is not allowed to exceed this length (i.e. of allocation).
+ * @return length of dname if dname is ok, 0 on a parse error.
+ */
+size_t dname_valid(uint8_t* dname, size_t len);
+
 /** lowercase query dname */
 void query_dname_tolower(uint8_t* dname, size_t len);
 
@@ -165,6 +173,14 @@ int dname_lab_cmp(uint8_t* d1, int labs1, uint8_t* d2, int labs2, int* mlabs);
  */
 int dname_strict_subdomain(uint8_t* d1, int labs1, uint8_t* d2, int labs2);
 
+/**
+ * Like dname_strict_subdomain but counts labels 
+ * @param d1: domain name, uncompressed wireformat
+ * @param d2: domain name, uncompressed wireformat
+ * @return true if d1 is a subdomain of d2, but not equal to d2.
+ */
+int dname_strict_subdomain_c(uint8_t* d1, uint8_t* d2);
+
 /** 
  * Debug helper. Print wireformat dname to output. 
  * @param out: like stdout or a file.

util/data/packed_rrset.c

@@ -190,3 +190,26 @@ packed_rrset_ptr_fixup(struct packed_rrset_data* data)
 		nextrdata += data->rr_len[i];
 	}
 }
+
+void 
+get_cname_target(struct ub_packed_rrset_key* rrset, uint8_t** dname, 
+	size_t* dname_len)
+{
+	struct packed_rrset_data* d;
+	size_t len;
+	if(ntohs(rrset->rk.type) != LDNS_RR_TYPE_CNAME)
+		return;
+	d = (struct packed_rrset_data*)rrset->entry.data;
+	if(d->count < 1)
+		return;
+	if(d->rr_len[0] < 3) /* at least rdatalen + 0byte root label */
+		return;
+	len = ldns_read_uint16(d->rr_data[0]);
+	if(len != d->rr_len[0] - sizeof(uint16_t))
+		return;
+	len -= sizeof(uint16_t);
+	if(dname_valid(d->rr_data[0]+sizeof(uint16_t), len) != len)
+		return;
+	*dname = d->rr_data[0]+sizeof(uint16_t);
+	*dname_len = len;
+}

util/data/packed_rrset.h

@@ -297,4 +297,17 @@ hashvalue_t rrset_key_hash(struct packed_rrset_key* key);
  */
 void packed_rrset_ptr_fixup(struct packed_rrset_data* data);
 
+/**
+ * Utility procedure to extract CNAME target name from its rdata.
+ * Failsafes; it will change passed dname to a valid dname or do nothing.
+ * @param rrset: the rrset structure. Must be a CNAME. 
+ *	Only first RR is used (multiple RRs are technically illegal anyway).
+ * @param dname: this pointer is updated to point into the cname rdata.
+ *	If a failsafe fails, nothing happens to the pointer (such as the
+ *	rdata was not a valid dname, not a CNAME, ...).
+ * @param dname_len: length of dname is returned.
+ */
+void get_cname_target(struct ub_packed_rrset_key* rrset, uint8_t** dname, 
+	size_t* dname_len);
+
 #endif /* UTIL_DATA_PACKED_RRSET_H */

util/net_help.h

@@ -53,6 +53,8 @@
 #define BIT_CD 0x0010
 /** QR flag */
 #define BIT_QR 0x8000
+/** get RCODE bits from uint16 flags */
+#define FLAGS_GET_RCODE(f) ((f) & 0xf)
 
 /** timeout in seconds for UDP queries to auth servers. TODO: proper rtt */
 #define UDP_QUERY_TIMEOUT 4