added unbound to external deps

1 files changed, 1024 insertions, 0 deletions

diff --git a/external/unbound/iterator/iter_utils.c b/external/unbound/iterator/iter_utils.c
new file mode 100644
index 000000000..5d55b623e
--- /dev/null
+++ b/external/unbound/iterator/iter_utils.c
@@ -0,0 +1,1024 @@
+/*
+ * iterator/iter_utils.c - iterative resolver module utility functions.
+ *
+ * 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 COPYRIGHT
+ * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
+ * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/**
+ * \file
+ *
+ * This file contains functions to assist the iterator module.
+ * Configuration options. Forward zones. 
+ */
+#include "config.h"
+#include "iterator/iter_utils.h"
+#include "iterator/iterator.h"
+#include "iterator/iter_hints.h"
+#include "iterator/iter_fwd.h"
+#include "iterator/iter_donotq.h"
+#include "iterator/iter_delegpt.h"
+#include "iterator/iter_priv.h"
+#include "services/cache/infra.h"
+#include "services/cache/dns.h"
+#include "services/cache/rrset.h"
+#include "util/net_help.h"
+#include "util/module.h"
+#include "util/log.h"
+#include "util/config_file.h"
+#include "util/regional.h"
+#include "util/data/msgparse.h"
+#include "util/data/dname.h"
+#include "util/random.h"
+#include "util/fptr_wlist.h"
+#include "validator/val_anchor.h"
+#include "validator/val_kcache.h"
+#include "validator/val_kentry.h"
+#include "validator/val_utils.h"
+#include "validator/val_sigcrypt.h"
+#include "ldns/sbuffer.h"
+
+/** time when nameserver glue is said to be 'recent' */
+#define SUSPICION_RECENT_EXPIRY 86400
+/** penalty to validation failed blacklisted IPs */
+#define BLACKLIST_PENALTY (USEFUL_SERVER_TOP_TIMEOUT*4)
+
+/** fillup fetch policy array */
+static void
+fetch_fill(struct iter_env* ie, const char* str)
+{
+	char* s = (char*)str, *e;
+	int i;
+	for(i=0; i<ie->max_dependency_depth+1; i++) {
+		ie->target_fetch_policy[i] = strtol(s, &e, 10);
+		if(s == e)
+			fatal_exit("cannot parse fetch policy number %s", s);
+		s = e;
+	}
+}
+
+/** Read config string that represents the target fetch policy */
+static int
+read_fetch_policy(struct iter_env* ie, const char* str)
+{
+	int count = cfg_count_numbers(str);
+	if(count < 1) {
+		log_err("Cannot parse target fetch policy: \"%s\"", str);
+		return 0;
+	}
+	ie->max_dependency_depth = count - 1;
+	ie->target_fetch_policy = (int*)calloc(
+		(size_t)ie->max_dependency_depth+1, sizeof(int));
+	if(!ie->target_fetch_policy) {
+		log_err("alloc fetch policy: out of memory");
+		return 0;
+	}
+	fetch_fill(ie, str);
+	return 1;
+}
+
+int 
+iter_apply_cfg(struct iter_env* iter_env, struct config_file* cfg)
+{
+	int i;
+	/* target fetch policy */
+	if(!read_fetch_policy(iter_env, cfg->target_fetch_policy))
+		return 0;
+	for(i=0; i<iter_env->max_dependency_depth+1; i++)
+		verbose(VERB_QUERY, "target fetch policy for level %d is %d",
+			i, iter_env->target_fetch_policy[i]);
+	
+	if(!iter_env->donotq)
+		iter_env->donotq = donotq_create();
+	if(!iter_env->donotq || !donotq_apply_cfg(iter_env->donotq, cfg)) {
+		log_err("Could not set donotqueryaddresses");
+		return 0;
+	}
+	if(!iter_env->priv)
+		iter_env->priv = priv_create();
+	if(!iter_env->priv || !priv_apply_cfg(iter_env->priv, cfg)) {
+		log_err("Could not set private addresses");
+		return 0;
+	}
+	iter_env->supports_ipv6 = cfg->do_ip6;
+	iter_env->supports_ipv4 = cfg->do_ip4;
+	return 1;
+}
+
+/** filter out unsuitable targets
+ * @param iter_env: iterator environment with ipv6-support flag.
+ * @param env: module environment with infra cache.
+ * @param name: zone name
+ * @param namelen: length of name
+ * @param qtype: query type (host order).
+ * @param now: current time
+ * @param a: address in delegation point we are examining.
+ * @return an integer that signals the target suitability.
+ *	as follows:
+ *	-1: The address should be omitted from the list.
+ *	    Because:
+ *		o The address is bogus (DNSSEC validation failure).
+ *		o Listed as donotquery
+ *		o is ipv6 but no ipv6 support (in operating system).
+ *		o is ipv4 but no ipv4 support (in operating system).
+ *		o is lame
+ *	Otherwise, an rtt in milliseconds.
+ *	0 .. USEFUL_SERVER_TOP_TIMEOUT-1
+ *		The roundtrip time timeout estimate. less than 2 minutes.
+ *		Note that util/rtt.c has a MIN_TIMEOUT of 50 msec, thus
+ *		values 0 .. 49 are not used, unless that is changed.
+ *	USEFUL_SERVER_TOP_TIMEOUT
+ *		This value exactly is given for unresponsive blacklisted.
+ *	USEFUL_SERVER_TOP_TIMEOUT+1
+ *		For non-blacklisted servers: huge timeout, but has traffic.
+ *	USEFUL_SERVER_TOP_TIMEOUT*1 ..
+ *		parent-side lame servers get this penalty. A dispreferential
+ *		server. (lame in delegpt).
+ *	USEFUL_SERVER_TOP_TIMEOUT*2 ..
+ *		dnsseclame servers get penalty
+ *	USEFUL_SERVER_TOP_TIMEOUT*3 ..
+ *		recursion lame servers get penalty
+ *	UNKNOWN_SERVER_NICENESS 
+ *		If no information is known about the server, this is
+ *		returned. 376 msec or so.
+ *	+BLACKLIST_PENALTY (of USEFUL_TOP_TIMEOUT*4) for dnssec failed IPs.
+ *
+ * When a final value is chosen that is dnsseclame ; dnsseclameness checking
+ * is turned off (so we do not discard the reply).
+ * When a final value is chosen that is recursionlame; RD bit is set on query.
+ * Because of the numbers this means recursionlame also have dnssec lameness
+ * checking turned off. 
+ */
+static int
+iter_filter_unsuitable(struct iter_env* iter_env, struct module_env* env,
+	uint8_t* name, size_t namelen, uint16_t qtype, time_t now, 
+	struct delegpt_addr* a)
+{
+	int rtt, lame, reclame, dnsseclame;
+	if(a->bogus)
+		return -1; /* address of server is bogus */
+	if(donotq_lookup(iter_env->donotq, &a->addr, a->addrlen)) {
+		log_addr(VERB_ALGO, "skip addr on the donotquery list",
+			&a->addr, a->addrlen);
+		return -1; /* server is on the donotquery list */
+	}
+	if(!iter_env->supports_ipv6 && addr_is_ip6(&a->addr, a->addrlen)) {
+		return -1; /* there is no ip6 available */
+	}
+	if(!iter_env->supports_ipv4 && !addr_is_ip6(&a->addr, a->addrlen)) {
+		return -1; /* there is no ip4 available */
+	}
+	/* check lameness - need zone , class info */
+	if(infra_get_lame_rtt(env->infra_cache, &a->addr, a->addrlen, 
+		name, namelen, qtype, &lame, &dnsseclame, &reclame, 
+		&rtt, now)) {
+		log_addr(VERB_ALGO, "servselect", &a->addr, a->addrlen);
+		verbose(VERB_ALGO, "   rtt=%d%s%s%s%s", rtt,
+			lame?" LAME":"",
+			dnsseclame?" DNSSEC_LAME":"",
+			reclame?" REC_LAME":"",
+			a->lame?" ADDR_LAME":"");
+		if(lame)
+			return -1; /* server is lame */
+		else if(rtt >= USEFUL_SERVER_TOP_TIMEOUT)
+			/* server is unresponsive,
+			 * we used to return TOP_TIMOUT, but fairly useless,
+			 * because if == TOP_TIMEOUT is dropped because
+			 * blacklisted later, instead, remove it here, so
+			 * other choices (that are not blacklisted) can be
+			 * tried */
+			return -1;
+		/* select remainder from worst to best */
+		else if(reclame)
+			return rtt+USEFUL_SERVER_TOP_TIMEOUT*3; /* nonpref */
+		else if(dnsseclame || a->dnsseclame)
+			return rtt+USEFUL_SERVER_TOP_TIMEOUT*2; /* nonpref */
+		else if(a->lame)
+			return rtt+USEFUL_SERVER_TOP_TIMEOUT+1; /* nonpref */
+		else	return rtt;
+	}
+	/* no server information present */
+	if(a->dnsseclame)
+		return UNKNOWN_SERVER_NICENESS+USEFUL_SERVER_TOP_TIMEOUT*2; /* nonpref */
+	else if(a->lame)
+		return USEFUL_SERVER_TOP_TIMEOUT+1+UNKNOWN_SERVER_NICENESS; /* nonpref */
+	return UNKNOWN_SERVER_NICENESS;
+}
+
+/** lookup RTT information, and also store fastest rtt (if any) */
+static int
+iter_fill_rtt(struct iter_env* iter_env, struct module_env* env,
+	uint8_t* name, size_t namelen, uint16_t qtype, time_t now, 
+	struct delegpt* dp, int* best_rtt, struct sock_list* blacklist)
+{
+	int got_it = 0;
+	struct delegpt_addr* a;
+	if(dp->bogus)
+		return 0; /* NS bogus, all bogus, nothing found */
+	for(a=dp->result_list; a; a = a->next_result) {
+		a->sel_rtt = iter_filter_unsuitable(iter_env, env, 
+			name, namelen, qtype, now, a);
+		if(a->sel_rtt != -1) {
+			if(sock_list_find(blacklist, &a->addr, a->addrlen))
+				a->sel_rtt += BLACKLIST_PENALTY;
+
+			if(!got_it) {
+				*best_rtt = a->sel_rtt;
+				got_it = 1;
+			} else if(a->sel_rtt < *best_rtt) {
+				*best_rtt = a->sel_rtt;
+			}
+		}
+	}
+	return got_it;
+}
+
+/** filter the addres list, putting best targets at front,
+ * returns number of best targets (or 0, no suitable targets) */
+static int
+iter_filter_order(struct iter_env* iter_env, struct module_env* env,
+	uint8_t* name, size_t namelen, uint16_t qtype, time_t now, 
+	struct delegpt* dp, int* selected_rtt, int open_target, 
+	struct sock_list* blacklist)
+{
+	int got_num = 0, low_rtt = 0, swap_to_front;
+	struct delegpt_addr* a, *n, *prev=NULL;
+
+	/* fillup sel_rtt and find best rtt in the bunch */
+	got_num = iter_fill_rtt(iter_env, env, name, namelen, qtype, now, dp, 
+		&low_rtt, blacklist);
+	if(got_num == 0) 
+		return 0;
+	if(low_rtt >= USEFUL_SERVER_TOP_TIMEOUT &&
+		(delegpt_count_missing_targets(dp) > 0 || open_target > 0)) {
+		verbose(VERB_ALGO, "Bad choices, trying to get more choice");
+		return 0; /* we want more choice. The best choice is a bad one.
+			     return 0 to force the caller to fetch more */
+	}
+
+	got_num = 0;
+	a = dp->result_list;
+	while(a) {
+		/* skip unsuitable targets */
+		if(a->sel_rtt == -1) {
+			prev = a;
+			a = a->next_result;
+			continue;
+		}
+		/* classify the server address and determine what to do */
+		swap_to_front = 0;
+		if(a->sel_rtt >= low_rtt && a->sel_rtt - low_rtt <= RTT_BAND) {
+			got_num++;
+			swap_to_front = 1;
+		} else if(a->sel_rtt<low_rtt && low_rtt-a->sel_rtt<=RTT_BAND) {
+			got_num++;
+			swap_to_front = 1;
+		}
+		/* swap to front if necessary, or move to next result */
+		if(swap_to_front && prev) {
+			n = a->next_result;
+			prev->next_result = n;
+			a->next_result = dp->result_list;
+			dp->result_list = a;
+			a = n;
+		} else {
+			prev = a;
+			a = a->next_result;
+		}
+	}
+	*selected_rtt = low_rtt;
+	return got_num;
+}
+
+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_lame,
+	int* chase_to_rd, int open_target, struct sock_list* blacklist)
+{
+	int sel;
+	int selrtt;
+	struct delegpt_addr* a, *prev;
+	int num = iter_filter_order(iter_env, env, name, namelen, qtype,
+		*env->now, dp, &selrtt, open_target, blacklist);
+
+	if(num == 0)
+		return NULL;
+	verbose(VERB_ALGO, "selrtt %d", selrtt);
+	if(selrtt > BLACKLIST_PENALTY) {
+		if(selrtt-BLACKLIST_PENALTY > USEFUL_SERVER_TOP_TIMEOUT*3) {
+			verbose(VERB_ALGO, "chase to "
+				"blacklisted recursion lame server");
+			*chase_to_rd = 1;
+		}
+		if(selrtt-BLACKLIST_PENALTY > USEFUL_SERVER_TOP_TIMEOUT*2) {
+			verbose(VERB_ALGO, "chase to "
+				"blacklisted dnssec lame server");
+			*dnssec_lame = 1;
+		}
+	} else {
+		if(selrtt > USEFUL_SERVER_TOP_TIMEOUT*3) {
+			verbose(VERB_ALGO, "chase to recursion lame server");
+			*chase_to_rd = 1;
+		}
+		if(selrtt > USEFUL_SERVER_TOP_TIMEOUT*2) {
+			verbose(VERB_ALGO, "chase to dnssec lame server");
+			*dnssec_lame = 1;
+		}
+		if(selrtt == USEFUL_SERVER_TOP_TIMEOUT) {
+			verbose(VERB_ALGO, "chase to blacklisted lame server");
+			return NULL;
+		}
+	}
+
+	if(num == 1) {
+		a = dp->result_list;
+		if(++a->attempts < OUTBOUND_MSG_RETRY)
+			return a;
+		dp->result_list = a->next_result;
+		return a;
+	}
+
+	/* randomly select a target from the list */
+	log_assert(num > 1);
+	/* grab secure random number, to pick unexpected server.
+	 * also we need it to be threadsafe. */
+	sel = ub_random_max(env->rnd, num); 
+	a = dp->result_list;
+	prev = NULL;
+	while(sel > 0 && a) {
+		prev = a;
+		a = a->next_result;
+		sel--;
+	}
+	if(!a)  /* robustness */
+		return NULL;
+	if(++a->attempts < OUTBOUND_MSG_RETRY)
+		return a;
+	/* remove it from the delegation point result list */
+	if(prev)
+		prev->next_result = a->next_result;
+	else	dp->result_list = a->next_result;
+	return a;
+}
+
+struct dns_msg* 
+dns_alloc_msg(sldns_buffer* pkt, struct msg_parse* msg, 
+	struct regional* region)
+{
+	struct dns_msg* m = (struct dns_msg*)regional_alloc(region,
+		sizeof(struct dns_msg));
+	if(!m)
+		return NULL;
+	memset(m, 0, sizeof(*m));
+	if(!parse_create_msg(pkt, msg, NULL, &m->qinfo, &m->rep, region)) {
+		log_err("malloc failure: allocating incoming dns_msg");
+		return NULL;
+	}
+	return m;
+}
+
+struct dns_msg* 
+dns_copy_msg(struct dns_msg* from, struct regional* region)
+{
+	struct dns_msg* m = (struct dns_msg*)regional_alloc(region,
+		sizeof(struct dns_msg));
+	if(!m)
+		return NULL;
+	m->qinfo = from->qinfo;
+	if(!(m->qinfo.qname = regional_alloc_init(region, from->qinfo.qname,
+		from->qinfo.qname_len)))
+		return NULL;
+	if(!(m->rep = reply_info_copy(from->rep, NULL, region)))
+		return NULL;
+	return m;
+}
+
+void 
+iter_dns_store(struct module_env* env, struct query_info* msgqinf,
+	struct reply_info* msgrep, int is_referral, time_t leeway, int pside,
+	struct regional* region)
+{
+	if(!dns_cache_store(env, msgqinf, msgrep, is_referral, leeway,
+		pside, region))
+		log_err("out of memory: cannot store data in cache");
+}
+
+int 
+iter_ns_probability(struct ub_randstate* rnd, int n, int m)
+{
+	int sel;
+	if(n == m) /* 100% chance */
+		return 1;
+	/* we do not need secure random numbers here, but
+	 * we do need it to be threadsafe, so we use this */
+	sel = ub_random_max(rnd, m); 
+	return (sel < n);
+}
+
+/** detect dependency cycle for query and target */
+static int
+causes_cycle(struct module_qstate* qstate, uint8_t* name, size_t namelen,
+	uint16_t t, uint16_t c)
+{
+	struct query_info qinf;
+	qinf.qname = name;
+	qinf.qname_len = namelen;
+	qinf.qtype = t;
+	qinf.qclass = c;
+	fptr_ok(fptr_whitelist_modenv_detect_cycle(
+		qstate->env->detect_cycle));
+	return (*qstate->env->detect_cycle)(qstate, &qinf, 
+		(uint16_t)(BIT_RD|BIT_CD), qstate->is_priming);
+}
+
+void 
+iter_mark_cycle_targets(struct module_qstate* qstate, struct delegpt* dp)
+{
+	struct delegpt_ns* ns;
+	for(ns = dp->nslist; ns; ns = ns->next) {
+		if(ns->resolved)
+			continue;
+		/* see if this ns as target causes dependency cycle */
+		if(causes_cycle(qstate, ns->name, ns->namelen, 
+			LDNS_RR_TYPE_AAAA, qstate->qinfo.qclass) ||
+		   causes_cycle(qstate, ns->name, ns->namelen, 
+			LDNS_RR_TYPE_A, qstate->qinfo.qclass)) {
+			log_nametypeclass(VERB_QUERY, "skipping target due "
+			 	"to dependency cycle (harden-glue: no may "
+				"fix some of the cycles)", 
+				ns->name, LDNS_RR_TYPE_A, 
+				qstate->qinfo.qclass);
+			ns->resolved = 1;
+		}
+	}
+}
+
+void 
+iter_mark_pside_cycle_targets(struct module_qstate* qstate, struct delegpt* dp)
+{
+	struct delegpt_ns* ns;
+	for(ns = dp->nslist; ns; ns = ns->next) {
+		if(ns->done_pside4 && ns->done_pside6)
+			continue;
+		/* see if this ns as target causes dependency cycle */
+		if(causes_cycle(qstate, ns->name, ns->namelen, 
+			LDNS_RR_TYPE_A, qstate->qinfo.qclass)) {
+			log_nametypeclass(VERB_QUERY, "skipping target due "
+			 	"to dependency cycle", ns->name,
+				LDNS_RR_TYPE_A, qstate->qinfo.qclass);
+			ns->done_pside4 = 1;
+		}
+		if(causes_cycle(qstate, ns->name, ns->namelen, 
+			LDNS_RR_TYPE_AAAA, qstate->qinfo.qclass)) {
+			log_nametypeclass(VERB_QUERY, "skipping target due "
+			 	"to dependency cycle", ns->name,
+				LDNS_RR_TYPE_AAAA, qstate->qinfo.qclass);
+			ns->done_pside6 = 1;
+		}
+	}
+}
+
+int 
+iter_dp_is_useless(struct query_info* qinfo, uint16_t qflags, 
+	struct delegpt* dp)
+{
+	struct delegpt_ns* ns;
+	/* check:
+	 *      o RD qflag is on.
+	 *      o no addresses are provided.
+	 *      o all NS items are required glue.
+	 * OR
+	 *      o RD qflag is on.
+	 *      o no addresses are provided.
+	 *      o the query is for one of the nameservers in dp,
+	 *        and that nameserver is a glue-name for this dp.
+	 */
+	if(!(qflags&BIT_RD))
+		return 0;
+	/* either available or unused targets */
+	if(dp->usable_list || dp->result_list)
+		return 0;
+	
+	/* see if query is for one of the nameservers, which is glue */
+	if( (qinfo->qtype == LDNS_RR_TYPE_A ||
+		qinfo->qtype == LDNS_RR_TYPE_AAAA) &&
+		dname_subdomain_c(qinfo->qname, dp->name) &&
+		delegpt_find_ns(dp, qinfo->qname, qinfo->qname_len))
+		return 1;
+	
+	for(ns = dp->nslist; ns; ns = ns->next) {
+		if(ns->resolved) /* skip failed targets */
+			continue;
+		if(!dname_subdomain_c(ns->name, dp->name))
+			return 0; /* one address is not required glue */
+	}
+	return 1;
+}
+
+int 
+iter_indicates_dnssec(struct module_env* env, struct delegpt* dp,
+        struct dns_msg* msg, uint16_t dclass)
+{
+	struct trust_anchor* a;
+	/* information not available, !env->anchors can be common */
+	if(!env || !env->anchors || !dp || !dp->name)
+		return 0;
+	/* a trust anchor exists with this name, RRSIGs expected */
+	if((a=anchor_find(env->anchors, dp->name, dp->namelabs, dp->namelen,
+		dclass))) {
+		lock_basic_unlock(&a->lock);
+		return 1;
+	}
+	/* see if DS rrset was given, in AUTH section */
+	if(msg && msg->rep &&
+		reply_find_rrset_section_ns(msg->rep, dp->name, dp->namelen,
+		LDNS_RR_TYPE_DS, dclass))
+		return 1;
+	/* look in key cache */
+	if(env->key_cache) {
+		struct key_entry_key* kk = key_cache_obtain(env->key_cache,
+			dp->name, dp->namelen, dclass, env->scratch, *env->now);
+		if(kk) {
+			if(query_dname_compare(kk->name, dp->name) == 0) {
+			  if(key_entry_isgood(kk) || key_entry_isbad(kk)) {
+				regional_free_all(env->scratch);
+				return 1;
+			  } else if(key_entry_isnull(kk)) {
+				regional_free_all(env->scratch);
+				return 0;
+			  }
+			}
+			regional_free_all(env->scratch);
+		}
+	}
+	return 0;
+}
+
+int 
+iter_msg_has_dnssec(struct dns_msg* msg)
+{
+	size_t i;
+	if(!msg || !msg->rep)
+		return 0;
+	for(i=0; i<msg->rep->an_numrrsets + msg->rep->ns_numrrsets; i++) {
+		if(((struct packed_rrset_data*)msg->rep->rrsets[i]->
+			entry.data)->rrsig_count > 0)
+			return 1;
+	}
+	/* empty message has no DNSSEC info, with DNSSEC the reply is
+	 * not empty (NSEC) */
+	return 0;
+}
+
+int iter_msg_from_zone(struct dns_msg* msg, struct delegpt* dp,
+        enum response_type type, uint16_t dclass)
+{
+	if(!msg || !dp || !msg->rep || !dp->name)
+		return 0;
+	/* SOA RRset - always from reply zone */
+	if(reply_find_rrset_section_an(msg->rep, dp->name, dp->namelen,
+		LDNS_RR_TYPE_SOA, dclass) ||
+	   reply_find_rrset_section_ns(msg->rep, dp->name, dp->namelen,
+		LDNS_RR_TYPE_SOA, dclass))
+		return 1;
+	if(type == RESPONSE_TYPE_REFERRAL) {
+		size_t i;
+		/* if it adds a single label, i.e. we expect .com,
+		 * and referral to example.com. NS ... , then origin zone
+		 * is .com. For a referral to sub.example.com. NS ... then
+		 * we do not know, since example.com. may be in between. */
+		for(i=0; i<msg->rep->an_numrrsets+msg->rep->ns_numrrsets; 
+			i++) {
+			struct ub_packed_rrset_key* s = msg->rep->rrsets[i];
+			if(ntohs(s->rk.type) == LDNS_RR_TYPE_NS &&
+				ntohs(s->rk.rrset_class) == dclass) {
+				int l = dname_count_labels(s->rk.dname);
+				if(l == dp->namelabs + 1 &&
+					dname_strict_subdomain(s->rk.dname,
+					l, dp->name, dp->namelabs))
+					return 1;
+			}
+		}
+		return 0;
+	}
+	log_assert(type==RESPONSE_TYPE_ANSWER || type==RESPONSE_TYPE_CNAME);
+	/* not a referral, and not lame delegation (upwards), so, 
+	 * any NS rrset must be from the zone itself */
+	if(reply_find_rrset_section_an(msg->rep, dp->name, dp->namelen,
+		LDNS_RR_TYPE_NS, dclass) ||
+	   reply_find_rrset_section_ns(msg->rep, dp->name, dp->namelen,
+		LDNS_RR_TYPE_NS, dclass))
+		return 1;
+	/* a DNSKEY set is expected at the zone apex as well */
+	/* this is for 'minimal responses' for DNSKEYs */
+	if(reply_find_rrset_section_an(msg->rep, dp->name, dp->namelen,
+		LDNS_RR_TYPE_DNSKEY, dclass))
+		return 1;
+	return 0;
+}
+
+/**
+ * check equality of two rrsets 
+ * @param k1: rrset
+ * @param k2: rrset
+ * @return true if equal
+ */
+static int
+rrset_equal(struct ub_packed_rrset_key* k1, struct ub_packed_rrset_key* k2)
+{
+	struct packed_rrset_data* d1 = (struct packed_rrset_data*)
+		k1->entry.data;
+	struct packed_rrset_data* d2 = (struct packed_rrset_data*)
+		k2->entry.data;
+	size_t i, t;
+	if(k1->rk.dname_len != k2->rk.dname_len ||
+		k1->rk.flags != k2->rk.flags ||
+		k1->rk.type != k2->rk.type ||
+		k1->rk.rrset_class != k2->rk.rrset_class ||
+		query_dname_compare(k1->rk.dname, k2->rk.dname) != 0)
+		return 0;
+	if(d1->ttl != d2->ttl ||
+		d1->count != d2->count ||
+		d1->rrsig_count != d2->rrsig_count ||
+		d1->trust != d2->trust ||
+		d1->security != d2->security)
+		return 0;
+	t = d1->count + d1->rrsig_count;
+	for(i=0; i<t; i++) {
+		if(d1->rr_len[i] != d2->rr_len[i] ||
+			d1->rr_ttl[i] != d2->rr_ttl[i] ||
+			memcmp(d1->rr_data[i], d2->rr_data[i], 
+				d1->rr_len[i]) != 0)
+			return 0;
+	}
+	return 1;
+}
+
+int 
+reply_equal(struct reply_info* p, struct reply_info* q, struct regional* region)
+{
+	size_t i;
+	if(p->flags != q->flags ||
+		p->qdcount != q->qdcount ||
+		p->ttl != q->ttl ||
+		p->prefetch_ttl != q->prefetch_ttl ||
+		p->security != q->security ||
+		p->an_numrrsets != q->an_numrrsets ||
+		p->ns_numrrsets != q->ns_numrrsets ||
+		p->ar_numrrsets != q->ar_numrrsets ||
+		p->rrset_count != q->rrset_count)
+		return 0;
+	for(i=0; i<p->rrset_count; i++) {
+		if(!rrset_equal(p->rrsets[i], q->rrsets[i])) {
+			if(!rrset_canonical_equal(region, p->rrsets[i],
+				q->rrsets[i])) {
+				regional_free_all(region);
+				return 0;
+			}
+			regional_free_all(region);
+		}
+	}
+	return 1;
+}
+
+void 
+iter_store_parentside_rrset(struct module_env* env, 
+	struct ub_packed_rrset_key* rrset)
+{
+	struct rrset_ref ref;
+	rrset = packed_rrset_copy_alloc(rrset, env->alloc, *env->now);
+	if(!rrset) {
+		log_err("malloc failure in store_parentside_rrset");
+		return;
+	}
+	rrset->rk.flags |= PACKED_RRSET_PARENT_SIDE;
+	rrset->entry.hash = rrset_key_hash(&rrset->rk);
+	ref.key = rrset;
+	ref.id = rrset->id;
+	/* ignore ret: if it was in the cache, ref updated */
+	(void)rrset_cache_update(env->rrset_cache, &ref, env->alloc, *env->now);
+}
+
+/** fetch NS record from reply, if any */
+static struct ub_packed_rrset_key*
+reply_get_NS_rrset(struct reply_info* rep)
+{
+	size_t i;
+	for(i=0; i<rep->rrset_count; i++) {
+		if(rep->rrsets[i]->rk.type == htons(LDNS_RR_TYPE_NS)) {
+			return rep->rrsets[i];
+		}
+	}
+	return NULL;
+}
+
+void
+iter_store_parentside_NS(struct module_env* env, struct reply_info* rep)
+{
+	struct ub_packed_rrset_key* rrset = reply_get_NS_rrset(rep);
+	if(rrset) {
+		log_rrset_key(VERB_ALGO, "store parent-side NS", rrset);
+		iter_store_parentside_rrset(env, rrset);
+	}
+}
+
+void iter_store_parentside_neg(struct module_env* env, 
+        struct query_info* qinfo, struct reply_info* rep)
+{
+	/* TTL: NS from referral in iq->deleg_msg,
+	 *      or first RR from iq->response,
+	 *      or servfail5secs if !iq->response */ 
+	time_t ttl = NORR_TTL;
+	struct ub_packed_rrset_key* neg;
+	struct packed_rrset_data* newd;
+	if(rep) {
+		struct ub_packed_rrset_key* rrset = reply_get_NS_rrset(rep);
+		if(!rrset && rep->rrset_count != 0) rrset = rep->rrsets[0];
+		if(rrset) ttl = ub_packed_rrset_ttl(rrset);
+	}
+	/* create empty rrset to store */
+	neg = (struct ub_packed_rrset_key*)regional_alloc(env->scratch,
+	                sizeof(struct ub_packed_rrset_key));
+	if(!neg) {
+		log_err("out of memory in store_parentside_neg");
+		return;
+	}
+	memset(&neg->entry, 0, sizeof(neg->entry));
+	neg->entry.key = neg;
+	neg->rk.type = htons(qinfo->qtype);
+	neg->rk.rrset_class = htons(qinfo->qclass);
+	neg->rk.flags = 0;
+	neg->rk.dname = regional_alloc_init(env->scratch, qinfo->qname, 
+		qinfo->qname_len);
+	if(!neg->rk.dname) {
+		log_err("out of memory in store_parentside_neg");
+		return;
+	}
+	neg->rk.dname_len = qinfo->qname_len;
+	neg->entry.hash = rrset_key_hash(&neg->rk);
+	newd = (struct packed_rrset_data*)regional_alloc_zero(env->scratch, 
+		sizeof(struct packed_rrset_data) + sizeof(size_t) +
+		sizeof(uint8_t*) + sizeof(time_t) + sizeof(uint16_t));
+	if(!newd) {
+		log_err("out of memory in store_parentside_neg");
+		return;
+	}
+	neg->entry.data = newd;
+	newd->ttl = ttl;
+	/* entry must have one RR, otherwise not valid in cache.
+	 * put in one RR with empty rdata: those are ignored as nameserver */
+	newd->count = 1;
+	newd->rrsig_count = 0;
+	newd->trust = rrset_trust_ans_noAA;
+	newd->rr_len = (size_t*)((uint8_t*)newd +
+		sizeof(struct packed_rrset_data));
+	newd->rr_len[0] = 0 /* zero len rdata */ + sizeof(uint16_t);
+	packed_rrset_ptr_fixup(newd);
+	newd->rr_ttl[0] = newd->ttl;
+	sldns_write_uint16(newd->rr_data[0], 0 /* zero len rdata */);
+	/* store it */
+	log_rrset_key(VERB_ALGO, "store parent-side negative", neg);
+	iter_store_parentside_rrset(env, neg);
+}
+
+int 
+iter_lookup_parent_NS_from_cache(struct module_env* env, struct delegpt* dp,
+	struct regional* region, struct query_info* qinfo)
+{
+	struct ub_packed_rrset_key* akey;
+	akey = rrset_cache_lookup(env->rrset_cache, dp->name, 
+		dp->namelen, LDNS_RR_TYPE_NS, qinfo->qclass, 
+		PACKED_RRSET_PARENT_SIDE, *env->now, 0);
+	if(akey) {
+		log_rrset_key(VERB_ALGO, "found parent-side NS in cache", akey);
+		dp->has_parent_side_NS = 1;
+		/* and mark the new names as lame */
+		if(!delegpt_rrset_add_ns(dp, region, akey, 1)) {
+			lock_rw_unlock(&akey->entry.lock);
+			return 0;
+		}
+		lock_rw_unlock(&akey->entry.lock);
+	}
+	return 1;
+}
+
+int iter_lookup_parent_glue_from_cache(struct module_env* env,
+        struct delegpt* dp, struct regional* region, struct query_info* qinfo)
+{
+	struct ub_packed_rrset_key* akey;
+	struct delegpt_ns* ns;
+	size_t num = delegpt_count_targets(dp);
+	for(ns = dp->nslist; ns; ns = ns->next) {
+		/* get cached parentside A */
+		akey = rrset_cache_lookup(env->rrset_cache, ns->name, 
+			ns->namelen, LDNS_RR_TYPE_A, qinfo->qclass, 
+			PACKED_RRSET_PARENT_SIDE, *env->now, 0);
+		if(akey) {
+			log_rrset_key(VERB_ALGO, "found parent-side", akey);
+			ns->done_pside4 = 1;
+			/* a negative-cache-element has no addresses it adds */
+			if(!delegpt_add_rrset_A(dp, region, akey, 1))
+				log_err("malloc failure in lookup_parent_glue");
+			lock_rw_unlock(&akey->entry.lock);
+		}
+		/* get cached parentside AAAA */
+		akey = rrset_cache_lookup(env->rrset_cache, ns->name, 
+			ns->namelen, LDNS_RR_TYPE_AAAA, qinfo->qclass, 
+			PACKED_RRSET_PARENT_SIDE, *env->now, 0);
+		if(akey) {
+			log_rrset_key(VERB_ALGO, "found parent-side", akey);
+			ns->done_pside6 = 1;
+			/* a negative-cache-element has no addresses it adds */
+			if(!delegpt_add_rrset_AAAA(dp, region, akey, 1))
+				log_err("malloc failure in lookup_parent_glue");
+			lock_rw_unlock(&akey->entry.lock);
+		}
+	}
+	/* see if new (but lame) addresses have become available */
+	return delegpt_count_targets(dp) != num;
+}
+
+int 
+iter_get_next_root(struct iter_hints* hints, struct iter_forwards* fwd, 
+	uint16_t* c)
+{
+	uint16_t c1 = *c, c2 = *c;
+	int r1 = hints_next_root(hints, &c1);
+	int r2 = forwards_next_root(fwd, &c2);
+	if(!r1 && !r2) /* got none, end of list */
+		return 0;
+	else if(!r1) /* got one, return that */
+		*c = c2;
+	else if(!r2)
+		*c = c1;
+	else if(c1 < c2) /* got both take smallest */
+		*c = c1;
+	else	*c = c2;
+	return 1;
+}
+
+void
+iter_scrub_ds(struct dns_msg* msg, struct ub_packed_rrset_key* ns, uint8_t* z)
+{
+	/* Only the DS record for the delegation itself is expected.
+	 * We allow DS for everything between the bailiwick and the 
+	 * zonecut, thus DS records must be at or above the zonecut.
+	 * And the DS records must be below the server authority zone.
+	 * The answer section is already scrubbed. */
+	size_t i = msg->rep->an_numrrsets;
+	while(i < (msg->rep->an_numrrsets + msg->rep->ns_numrrsets)) {
+		struct ub_packed_rrset_key* s = msg->rep->rrsets[i];
+		if(ntohs(s->rk.type) == LDNS_RR_TYPE_DS &&
+			(!ns || !dname_subdomain_c(ns->rk.dname, s->rk.dname)
+			|| query_dname_compare(z, s->rk.dname) == 0)) {
+			log_nametypeclass(VERB_ALGO, "removing irrelevant DS",
+				s->rk.dname, ntohs(s->rk.type),
+				ntohs(s->rk.rrset_class));
+			memmove(msg->rep->rrsets+i, msg->rep->rrsets+i+1,
+				sizeof(struct ub_packed_rrset_key*) * 
+				(msg->rep->rrset_count-i-1));
+			msg->rep->ns_numrrsets--;
+			msg->rep->rrset_count--;
+			/* stay at same i, but new record */
+			continue;
+		}
+		i++;
+	}
+}
+
+void iter_dec_attempts(struct delegpt* dp, int d)
+{
+	struct delegpt_addr* a;
+	for(a=dp->target_list; a; a = a->next_target) {
+		if(a->attempts >= OUTBOUND_MSG_RETRY) {
+			/* add back to result list */
+			a->next_result = dp->result_list;
+			dp->result_list = a;
+		}
+		if(a->attempts > d)
+			a->attempts -= d;
+		else a->attempts = 0;
+	}
+}
+
+void iter_merge_retry_counts(struct delegpt* dp, struct delegpt* old)
+{
+	struct delegpt_addr* a, *o, *prev;
+	for(a=dp->target_list; a; a = a->next_target) {
+		o = delegpt_find_addr(old, &a->addr, a->addrlen);
+		if(o) {
+			log_addr(VERB_ALGO, "copy attempt count previous dp",
+				&a->addr, a->addrlen);
+			a->attempts = o->attempts;
+		}
+	}
+	prev = NULL;
+	a = dp->usable_list;
+	while(a) {
+		if(a->attempts >= OUTBOUND_MSG_RETRY) {
+			log_addr(VERB_ALGO, "remove from usable list dp",
+				&a->addr, a->addrlen);
+			/* remove from result list */
+			if(prev)
+				prev->next_usable = a->next_usable;
+			else	dp->usable_list = a->next_usable;
+			/* prev stays the same */
+			a = a->next_usable;
+			continue;
+		}
+		prev = a;
+		a = a->next_usable;
+	}
+}
+
+int
+iter_ds_toolow(struct dns_msg* msg, struct delegpt* dp)
+{
+	/* if for query example.com, there is example.com SOA or a subdomain
+	 * of example.com, then we are too low and need to fetch NS. */
+	size_t i;
+	/* if we have a DNAME or CNAME we are probably wrong */
+	/* if we have a qtype DS in the answer section, its fine */
+	for(i=0; i < msg->rep->an_numrrsets; i++) {
+		struct ub_packed_rrset_key* s = msg->rep->rrsets[i];
+		if(ntohs(s->rk.type) == LDNS_RR_TYPE_DNAME ||
+			ntohs(s->rk.type) == LDNS_RR_TYPE_CNAME) {
+			/* not the right answer, maybe too low, check the
+			 * RRSIG signer name (if there is any) for a hint
+			 * that it is from the dp zone anyway */
+			uint8_t* sname;
+			size_t slen;
+			val_find_rrset_signer(s, &sname, &slen);
+			if(sname && query_dname_compare(dp->name, sname)==0)
+				return 0; /* it is fine, from the right dp */
+			return 1;
+		}
+		if(ntohs(s->rk.type) == LDNS_RR_TYPE_DS)
+			return 0; /* fine, we have a DS record */
+	}
+	for(i=msg->rep->an_numrrsets;
+		i < msg->rep->an_numrrsets + msg->rep->ns_numrrsets; i++) {
+		struct ub_packed_rrset_key* s = msg->rep->rrsets[i];
+		if(ntohs(s->rk.type) == LDNS_RR_TYPE_SOA) {
+			if(dname_subdomain_c(s->rk.dname, msg->qinfo.qname))
+				return 1; /* point is too low */
+			if(query_dname_compare(s->rk.dname, dp->name)==0)
+				return 0; /* right dp */
+		}
+		if(ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC ||
+			ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC3) {
+			uint8_t* sname;
+			size_t slen;
+			val_find_rrset_signer(s, &sname, &slen);
+			if(sname && query_dname_compare(dp->name, sname)==0)
+				return 0; /* it is fine, from the right dp */
+			return 1;
+		}
+	}
+	/* we do not know */
+	return 1;
+}
+
+int iter_dp_cangodown(struct query_info* qinfo, struct delegpt* dp)
+{
+	/* no delegation point, do not see how we can go down,
+	 * robust check, it should really exist */
+	if(!dp) return 0;
+
+	/* see if dp equals the qname, then we cannot go down further */
+	if(query_dname_compare(qinfo->qname, dp->name) == 0)
+		return 0;
+	/* if dp is one label above the name we also cannot go down further */
+	if(dname_count_labels(qinfo->qname) == dp->namelabs+1)
+		return 0;
+	return 1;
+}