- subrequests without parent store in cache and stop.

- worker slumber list for ongoing promiscuous queries.
       - subrequest error handling.



git-svn-id: file:///svn/unbound/trunk@368 be551aaa-1e26-0410-a405-d3ace91eadb9

daemon/worker.c

@@ -79,16 +79,11 @@ worker_send_cmd(struct worker* worker, ldns_buffer* buffer,
 
 /** delete subrequest */
 static void
-qstate_free(struct worker* worker, struct module_qstate* qstate)
+qstate_cleanup(struct worker* worker, struct module_qstate* qstate)
 {
 	int i;
 	if(!qstate)
 		return;
-	/* remove subqueries */
-	while(qstate->subquery_first) {
-		qstate_free(worker, qstate->subquery_first);
-	}
-	log_assert(qstate->subquery_first == NULL);
 	/* call de-init while all is OK */
 	for(i=0; i<worker->daemon->num_modules; i++)
 		(*worker->daemon->modfunc[i]->clear)(qstate, i);
@@ -96,12 +91,55 @@ qstate_free(struct worker* worker, struct module_qstate* qstate)
 	region_free_all(qstate->region);
 	query_info_clear(&qstate->qinfo);
 	if(qstate->parent) {
-		module_subreq_remove(qstate);
+		/* subquery of parent */
+		module_subreq_remove(&qstate->parent->subquery_first, qstate);
 		region_destroy(qstate->region);
 		free(qstate);
+	} else if (!qstate->work_info) {
+		/* slumbering query */
+		module_subreq_remove(&worker->slumber_list, qstate);
+		region_destroy(qstate->region);
+		free(qstate);
+		verbose(VERB_ALGO, "cleanup: slumber list has %d entries",
+			module_subreq_num(worker->slumber_list));
 	}
 }
 
+/** delete subrequest recursively */
+static void
+qstate_free_recurs_list(struct worker* worker, struct module_qstate* list)
+{
+	struct module_qstate* n;
+	/* remove subqueries */
+	while(list) {
+		n = list->subquery_next;
+		qstate_free_recurs_list(worker, list->subquery_first);
+		qstate_cleanup(worker, list);
+		list = n;
+	}
+}
+
+/** delete subrequest */
+static void
+qstate_free(struct worker* worker, struct module_qstate* qstate)
+{
+	if(!qstate)
+		return;
+	while(qstate->subquery_first) {
+		/* put subqueries on slumber list */
+		struct module_qstate* s = qstate->subquery_first;
+		module_subreq_remove(&qstate->subquery_first, s);
+		s->parent = NULL;
+		s->work_info = NULL;
+		s->subquery_next = worker->slumber_list;
+		s->subquery_prev = NULL;
+		worker->slumber_list = s;
+	}
+	verbose(VERB_ALGO, "worker: slumber list has %d entries",
+		module_subreq_num(worker->slumber_list));
+	qstate_cleanup(worker, qstate);
+}
+
 /** release workrequest back to the freelist,
  * note that the w->qinfo still needs to be cleared after this. 
  */
@@ -237,7 +275,7 @@ worker_process_query(struct worker* worker, struct work_query* w,
 			qstate_free(worker, qstate);
 			qstate = up;
 			entry = NULL;
-			event = module_event_error;
+			event = module_event_subq_error;
 			continue;
 		}
 		if(s == module_finished && qstate->parent) {
@@ -261,16 +299,21 @@ worker_process_query(struct worker* worker, struct work_query* w,
 	}
 	/* request done */
 	if(s == module_error) {
-		replyerror(LDNS_RCODE_SERVFAIL, w);
+		if(w) {
+			replyerror(LDNS_RCODE_SERVFAIL, w);
+			req_release(w);
+		}
 		qstate_free(worker, qstate);
 		return;
 	}
 	if(s == module_finished) {
-		memcpy(ldns_buffer_begin(w->query_reply.c->buffer),
-			&w->query_id, sizeof(w->query_id));
-		comm_point_send_reply(&w->query_reply);
+		if(w) {
+			memcpy(ldns_buffer_begin(w->query_reply.c->buffer),
+				&w->query_id, sizeof(w->query_id));
+			comm_point_send_reply(&w->query_reply);
+			req_release(w);
+		}
 		qstate_free(worker, qstate);
-		req_release(w);
 		return;
 	}
 	/* suspend, waits for wakeup callback */
@@ -312,7 +355,7 @@ worker_handle_service_reply(struct comm_point* c, void* arg, int error,
 {
 	struct outbound_entry* e = (struct outbound_entry*)arg;
 	struct work_query* w = e->qstate->work_info;
-	struct worker* worker = w->state.env->worker;
+	struct worker* worker = e->qstate->env->worker;
 
 	e->qstate->reply = reply_info;
 	if(error != 0) {
@@ -656,7 +699,8 @@ reqs_delete(struct worker* worker)
 		n = q->all_next;
 		log_assert(q->state.env->worker == worker);
 		/* comm_reply closed in outside_network_delete */
-		qstate_free(worker, &q->state);
+		qstate_free_recurs_list(worker, q->state.subquery_first);
+		qstate_cleanup(worker, &q->state);
 		region_destroy(q->state.region);
 		free(q);
 		q = n;
@@ -751,6 +795,7 @@ worker_init(struct worker* worker, struct config_file *cfg,
 		worker_delete(worker);
 		return 0;
 	}
+	worker->slumber_list = NULL;
 
 	server_stats_init(&worker->stats);
 	alloc_init(&worker->alloc, &worker->daemon->superalloc, 
@@ -775,6 +820,7 @@ worker_delete(struct worker* worker)
 		return;
 	server_stats_log(&worker->stats, worker->thread_num);
 	reqs_delete(worker);
+	qstate_free_recurs_list(worker, worker->slumber_list);
 	listen_delete(worker->front);
 	outside_network_delete(worker->back);
 	comm_signal_delete(worker->comsig);

daemon/worker.h

@@ -116,6 +116,8 @@ struct worker {
 	struct work_query* free_queries;
 	/** list of all working queries */
 	struct work_query* all_queries;
+	/** list of slumbering states, with promiscuous queries */
+	struct module_qstate* slumber_list;
 
 	/** random() table for this worker. */
 	struct ub_randstate* rndstate;

doc/Changelog

@@ -1,5 +1,8 @@
 5 June 2007: Wouter
 	- iterator state finished.
+	- subrequests without parent store in cache and stop.
+	- worker slumber list for ongoing promiscuous queries.
+	- subrequest error handling.
 
 4 June 2007: Wouter
 	- random selection of equally preferred nameserver targets.

iterator/iterator.c

@@ -253,11 +253,30 @@ final_state(struct module_qstate* qstate, struct iter_qstate* iq)
 static int
 error_response(struct module_qstate* qstate, int id, int rcode)
 {
+	struct iter_qstate* iq = (struct iter_qstate*)qstate->minfo[id];
 	log_info("err response %s", ldns_lookup_by_id(ldns_rcodes, rcode)?
 		ldns_lookup_by_id(ldns_rcodes, rcode)->name:"??");
+	if(iq && iq->orig_qname) {
+		/* encode original query */
+		qstate->qinfo.qname = iq->orig_qname;
+		qstate->qinfo.qname_len = iq->orig_qnamelen;
+		qstate->query_flags = iq->orig_qflags;
+	}
 	qinfo_query_encode(qstate->buf, &qstate->qinfo);
 	LDNS_RCODE_SET(ldns_buffer_begin(qstate->buf), rcode);
+	LDNS_RA_SET(ldns_buffer_begin(qstate->buf));
 	LDNS_QR_SET(ldns_buffer_begin(qstate->buf));
+	if((qstate->query_flags & BIT_RD))
+		LDNS_RD_SET(ldns_buffer_begin(qstate->buf));
+	if((qstate->query_flags & BIT_CD))
+		LDNS_CD_SET(ldns_buffer_begin(qstate->buf));
+
+	if(qstate->parent) {
+		/* return subquery error module event to parent */
+		qstate->ext_state[id] = module_error;
+		return 0;
+	}
+	/* return to client */
 	qstate->ext_state[id] = module_finished;
 	return 0;
 }
@@ -468,6 +487,7 @@ generate_sub_request(uint8_t* qname, size_t qnamelen, uint16_t qtype,
 	subq->work_info = qstate->work_info;
 	subq->parent = qstate;
 	subq->subquery_next = qstate->subquery_first;
+	subq->subquery_prev = NULL;
 	qstate->subquery_first = subq;
 
 	subiq = (struct iter_qstate*)subq->minfo[id];
@@ -571,7 +591,7 @@ prime_stub(struct module_qstate* qstate, struct iter_qstate* iq,
 		QUERYTARGETS_STATE, PRIME_RESP_STATE);
 	if(!subq) {
 		log_err("out of memory priming stub");
-		qstate->ext_state[id] = module_error;
+		(void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
 		return 1; /* return 1 to make module stop, with error */
 	}
 	subiq = (struct iter_qstate*)subq->minfo[id];
@@ -844,7 +864,10 @@ generate_target_query(struct module_qstate* qstate, struct iter_qstate* iq,
 	subiq = (struct iter_qstate*)subq->minfo[id];
 	subiq->dp = delegpt_copy(iq->dp, subq->region);
 	if(!subiq->dp) {
-		subq->ext_state[id] = module_error;
+		module_subreq_remove(&qstate->subquery_first, subq);
+		region_destroy(subq->region);
+		free(subq->qinfo.qname);
+		free(subq);
 		return 0;
 	}
 	return 1;
@@ -1082,7 +1105,6 @@ processQueryResponse(struct module_qstate* qstate, struct iter_qstate* iq,
 {
 	enum response_type type;
 	iq->num_current_queries--;
-	qstate->ext_state[id] = module_error; /* debug, must be overridden */
 	if(iq->response == NULL) {
 		verbose(VERB_ALGO, "query response was timeout");
 		return next_state(qstate, iq, QUERYTARGETS_STATE);
@@ -1214,7 +1236,14 @@ processPrimeResponse(struct module_qstate* qstate, struct iter_qstate* iq,
 	struct delegpt* dp = NULL;
 	enum response_type type = response_type_from_server(iq->response, 
 		&qstate->qinfo, iq->dp);
-	log_assert(qstate->parent); /* this is a subrequest of another */
+
+	/* This event is finished. */
+	qstate->ext_state[id] = module_finished;
+
+	if(!qstate->parent) {
+		/* no more parent - it is not interested anymore */
+		return 0;
+	}
 	if(type == RESPONSE_TYPE_ANSWER) {
 		/* Convert our response to a delegation point */
 		dp = delegpt_from_message(iq->response, forq->region);
@@ -1224,23 +1253,17 @@ processPrimeResponse(struct module_qstate* qstate, struct iter_qstate* iq,
 		 * the ANSWER type was (presumably) a negative answer. */
 		verbose(VERB_ALGO, "prime response was not a positive "
 			"ANSWER; failing");
-		/* note that this will call the forevent with event error. */
-		qstate->ext_state[id] = module_error;
-		return 0;
+		return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
 	}
 
 	log_nametypeclass("priming successful for", qstate->qinfo.qname,
 		qstate->qinfo.qtype, qstate->qinfo.qclass);
-	/* This event is finished. */
-	qstate->ext_state[id] = module_finished;
 	foriq = (struct iter_qstate*)forq->minfo[id];
 	foriq->dp = dp;
 	foriq->response = dns_copy_msg(iq->response, forq->region);
 	if(!foriq->response) {
 		log_err("copy prime response: out of memory");
-		/* note that this will call the forevent with event error. */
-		qstate->ext_state[id] = module_error;
-		return 0;
+		return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
 	}
 
 	/* root priming responses go to init stage 2, priming stub 
@@ -1274,9 +1297,14 @@ processTargetResponse(struct module_qstate* qstate, struct iter_qstate* iq,
 	struct delegpt_ns* dpns;
 	struct module_qstate* forq = qstate->parent;
 	struct iter_qstate* foriq;
-	log_assert(qstate->parent); /* fetch targets for a parent */
-	foriq = (struct iter_qstate*)forq->minfo[id];
+
 	qstate->ext_state[id] = module_finished;
+	if(!qstate->parent) {
+		/* no parent, it is not interested anymore */
+		return 0;
+	}
+
+	foriq = (struct iter_qstate*)forq->minfo[id];
 
 	/* check to see if parent event is still interested.  */
 	if(iq->orig_qname)
@@ -1460,7 +1488,7 @@ process_response(struct module_qstate* qstate, struct iter_qstate* iq,
 	if(event != module_event_reply || !qstate->reply) {
 		log_err("Bad event combined with response");
 		outbound_list_remove(&iq->outlist, outbound);
-		qstate->ext_state[id] = module_error;
+		(void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
 		return;
 	}
 
@@ -1496,6 +1524,48 @@ handle_it:
 	outbound_list_remove(&iq->outlist, outbound);
 	iter_handle(qstate, iq, ie, id);
 }
+/** 
+ * Handles subquery errors. Checks if query is still relevant, and adjusts
+ * the state.
+ * @param qstate: query state.
+ * @param ie: iterator shared global environment.
+ * @param iq: iterator query state.
+ * @param id: module id.
+ */
+static void
+process_subq_error(struct module_qstate* qstate, struct iter_qstate* iq,
+	struct iter_env* ie, int id)
+{
+	struct query_info errinf;
+	struct delegpt_ns* dpns = NULL;
+	if(!query_info_parse(&errinf, qstate->buf)) {
+		log_err("Could not parse error from sub module");
+		return;
+	}
+	if(errinf.qtype == LDNS_RR_TYPE_NS) {
+		/* a priming query has failed. */
+		iter_handle(qstate, iq, ie, id);
+		return;
+	}
+	if(errinf.qtype != LDNS_RR_TYPE_A && 
+		errinf.qtype != LDNS_RR_TYPE_AAAA) {
+		log_err("Bad error from sub module");
+		return;
+	}
+	/* see if we are still interested in this subquery result */
+	
+	if(!iq->dp)
+		dpns = delegpt_find_ns(iq->dp, errinf.qname, 
+			errinf.qname_len);
+	if(!dpns) {
+		/* not interested */
+		return;
+	}
+	dpns->resolved = 1; /* mark as failed */
+	iq->num_target_queries--; /* and the query is finished */
+	iq->state = QUERYTARGETS_STATE; /* evaluate targets again */
+	iter_handle(qstate, iq, ie, id);
+}
 
 /** iterator operate on a query */
 static void 
@@ -1514,7 +1584,7 @@ iter_operate(struct module_qstate* qstate, enum module_ev event, int id,
 	if(event == module_event_new && iq == NULL) {
 		log_info("iter state machine");
 		if(!iter_new(qstate, id)) {
-			qstate->ext_state[id] = module_error;
+			(void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
 			return;
 		}
 		iq = (struct iter_qstate*)qstate->minfo[id];
@@ -1529,14 +1599,24 @@ iter_operate(struct module_qstate* qstate, enum module_ev event, int id,
 		process_response(qstate, iq, ie, id, outbound, event);
 		return;
 	}
+	if(event == module_event_subq_done) {
+		/* subquery has set our state correctly */
+		iter_handle(qstate, iq, ie, id);
+		return;
+	}
+	if(event == module_event_subq_error) {
+		/* need to delist subquery and continue processing */
+		process_subq_error(qstate, iq, ie, id);
+		return;
+	}
 	if(event == module_event_error) {
 		verbose(VERB_ALGO, "got called with event error, giving up");
-		qstate->ext_state[id] = module_error;
+		(void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
 		return;
 	}
 
 	log_err("bad event for iterator");
-	qstate->ext_state[id] = module_error;
+	(void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
 }
 
 /** iterator cleanup query state */

util/module.c

@@ -64,28 +64,26 @@ strmodulevent(enum module_ev e)
 	case module_event_timeout: return "module_event_timeout";
 	case module_event_mod_done: return "module_event_mod_done";
 	case module_event_subq_done: return "module_event_subq_done";
+	case module_event_subq_error: return "module_event_subq_error";
 	case module_event_error: return "module_event_error";
 	}
 	return "bad_event_value";
 }
 
 void 
-module_subreq_remove(struct module_qstate* sub)
+module_subreq_remove(struct module_qstate** head, struct module_qstate* sub)
 {
-	struct module_qstate* p, *prev = NULL;
-	if(!sub || !sub->parent) 
+	if(!sub || !head) 
 		return;
-	p = sub->parent->subquery_first;
-	while(p) {
-		if(p == sub) {
-			/* snip it off */
-			if(prev) prev->subquery_next = p->subquery_next;
-			else sub->parent->subquery_first = p->subquery_next;
-			return;
-		}
-		prev = p;
-		p = p->subquery_next;
-	}
+	/* snip off double linked list */
+	if(sub->subquery_prev)
+		sub->subquery_prev->subquery_next = sub->subquery_next;
+	else	*head = sub->subquery_next;
+	if(sub->subquery_next)
+		sub->subquery_next->subquery_prev = sub->subquery_prev;
+	/* cleanup values for robustness */
+	sub->subquery_next = NULL;
+	sub->subquery_prev = NULL;
 }
 
 int 
@@ -98,3 +96,14 @@ module_subreq_depth(struct module_qstate* sub)
 	}
 	return d;
 }
+
+int 
+module_subreq_num(struct module_qstate* q)
+{
+	int n = 0;
+	while(q) {
+		n++;
+		q = q->subquery_next;
+	}
+	return n;
+}

util/module.h

@@ -163,6 +163,8 @@ enum module_ev {
 	module_event_mod_done,
 	/** subquery finished */
 	module_event_subq_done,
+	/** subquery finished with error */
+	module_event_subq_error,
 	/** error */
 	module_event_error
 };
@@ -198,15 +200,19 @@ struct module_qstate {
 	void* minfo[MAX_MODULE];
 	/** environment for this query */
 	struct module_env* env;
-	/** worker related state for this query */
+	/** worker related state for this query. NULL for queries that do
+	 * not need to have answers sent to a client. */
 	struct work_query* work_info;
 
 	/** parent query, only nonNULL for subqueries */
 	struct module_qstate* parent;
 	/** pointer to first subquery below this one; makes list with next */
 	struct module_qstate* subquery_first;
+
 	/** pointer to next sibling subquery (not above or below this one) */
 	struct module_qstate* subquery_next;
+	/** pointer to prev sibling subquery (not above or below this one) */
+	struct module_qstate* subquery_prev;
 };
 
 /** 
@@ -271,10 +277,13 @@ const char* strmodulevent(enum module_ev e);
 
 /**
  * Remove subqrequest from list.
+ * @param head: List head. pointer to start of subquery_next/prev sibling list.
+ *	mostly reference to the parent subquery_first.
  * @param sub: subrequest. Parent pointer used to access list.
  * 	It is snipped off. 
  */
-void module_subreq_remove(struct module_qstate* sub);
+void module_subreq_remove(struct module_qstate** head, 
+	struct module_qstate* sub);
 
 /**
  * Calculate depth of subrequest
@@ -283,4 +292,11 @@ void module_subreq_remove(struct module_qstate* sub);
  */
 int module_subreq_depth(struct module_qstate* sub);
 
+/**
+ * Calculate number of queries in the query list.
+ * @param q: the start of the list, pass subquery_first.
+ * @return: number, 0 if q was NULL.
+ */
+int module_subreq_num(struct module_qstate* q);
+
 #endif /* UTIL_MODULE_H */