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      1 /*
      2  * iterator/iter_delegpt.c - delegation point with NS and address information.
      3  *
      4  * Copyright (c) 2007, NLnet Labs. All rights reserved.
      5  *
      6  * This software is open source.
      7  *
      8  * Redistribution and use in source and binary forms, with or without
      9  * modification, are permitted provided that the following conditions
     10  * are met:
     11  *
     12  * Redistributions of source code must retain the above copyright notice,
     13  * this list of conditions and the following disclaimer.
     14  *
     15  * Redistributions in binary form must reproduce the above copyright notice,
     16  * this list of conditions and the following disclaimer in the documentation
     17  * and/or other materials provided with the distribution.
     18  *
     19  * Neither the name of the NLNET LABS nor the names of its contributors may
     20  * be used to endorse or promote products derived from this software without
     21  * specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     24  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     25  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     26  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     27  * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     28  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
     29  * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
     30  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
     31  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
     32  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
     33  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     34  */
     35 
     36 /**
     37  * \file
     38  *
     39  * This file implements the Delegation Point. It contains a list of name servers
     40  * and their addresses if known.
     41  */
     42 #include "config.h"
     43 #include "iterator/iter_delegpt.h"
     44 #include "services/cache/dns.h"
     45 #include "util/regional.h"
     46 #include "util/data/dname.h"
     47 #include "util/data/packed_rrset.h"
     48 #include "util/data/msgreply.h"
     49 #include "util/net_help.h"
     50 #include "sldns/rrdef.h"
     51 #include "sldns/sbuffer.h"
     52 
     53 struct delegpt*
     54 delegpt_create(struct regional* region)
     55 {
     56 	struct delegpt* dp=(struct delegpt*)regional_alloc(
     57 		region, sizeof(*dp));
     58 	if(!dp)
     59 		return NULL;
     60 	memset(dp, 0, sizeof(*dp));
     61 	return dp;
     62 }
     63 
     64 struct delegpt* delegpt_copy(struct delegpt* dp, struct regional* region)
     65 {
     66 	struct delegpt* copy = delegpt_create(region);
     67 	struct delegpt_ns* ns;
     68 	struct delegpt_addr* a;
     69 	if(!copy)
     70 		return NULL;
     71 	if(!delegpt_set_name(copy, region, dp->name))
     72 		return NULL;
     73 	copy->bogus = dp->bogus;
     74 	copy->has_parent_side_NS = dp->has_parent_side_NS;
     75 	copy->ssl_upstream = dp->ssl_upstream;
     76 	copy->tcp_upstream = dp->tcp_upstream;
     77 	for(ns = dp->nslist; ns; ns = ns->next) {
     78 		if(!delegpt_add_ns(copy, region, ns->name, ns->lame,
     79 			ns->tls_auth_name, ns->port))
     80 			return NULL;
     81 		copy->nslist->cache_lookup_count = ns->cache_lookup_count;
     82 		copy->nslist->resolved = ns->resolved;
     83 		copy->nslist->got4 = ns->got4;
     84 		copy->nslist->got6 = ns->got6;
     85 		copy->nslist->done_pside4 = ns->done_pside4;
     86 		copy->nslist->done_pside6 = ns->done_pside6;
     87 	}
     88 	for(a = dp->target_list; a; a = a->next_target) {
     89 		if(!delegpt_add_addr(copy, region, &a->addr, a->addrlen,
     90 			a->bogus, a->lame, a->tls_auth_name, -1, NULL))
     91 			return NULL;
     92 	}
     93 	return copy;
     94 }
     95 
     96 int
     97 delegpt_set_name(struct delegpt* dp, struct regional* region, uint8_t* name)
     98 {
     99 	log_assert(!dp->dp_type_mlc);
    100 	dp->namelabs = dname_count_size_labels(name, &dp->namelen);
    101 	dp->name = regional_alloc_init(region, name, dp->namelen);
    102 	return dp->name != 0;
    103 }
    104 
    105 int
    106 delegpt_add_ns(struct delegpt* dp, struct regional* region, uint8_t* name,
    107 	uint8_t lame, char* tls_auth_name, int port)
    108 {
    109 	struct delegpt_ns* ns;
    110 	size_t len;
    111 	(void)dname_count_size_labels(name, &len);
    112 	log_assert(!dp->dp_type_mlc);
    113 	/* slow check for duplicates to avoid counting failures when
    114 	 * adding the same server as a dependency twice */
    115 	if(delegpt_find_ns(dp, name, len))
    116 		return 1;
    117 	ns = (struct delegpt_ns*)regional_alloc(region,
    118 		sizeof(struct delegpt_ns));
    119 	if(!ns)
    120 		return 0;
    121 	ns->namelen = len;
    122 	ns->name = regional_alloc_init(region, name, ns->namelen);
    123 	if(!ns->name)
    124 		return 0;
    125 	ns->cache_lookup_count = 0;
    126 	ns->resolved = 0;
    127 	ns->got4 = 0;
    128 	ns->got6 = 0;
    129 	ns->lame = lame;
    130 	ns->done_pside4 = 0;
    131 	ns->done_pside6 = 0;
    132 	ns->port = port;
    133 	if(tls_auth_name) {
    134 		ns->tls_auth_name = regional_strdup(region, tls_auth_name);
    135 		if(!ns->tls_auth_name)
    136 			return 0;
    137 	} else {
    138 		ns->tls_auth_name = NULL;
    139 	}
    140 	ns->next = dp->nslist;
    141 	dp->nslist = ns;
    142 	return 1;
    143 }
    144 
    145 struct delegpt_ns*
    146 delegpt_find_ns(struct delegpt* dp, uint8_t* name, size_t namelen)
    147 {
    148 	struct delegpt_ns* p = dp->nslist;
    149 	while(p) {
    150 		if(namelen == p->namelen &&
    151 			query_dname_compare(name, p->name) == 0) {
    152 			return p;
    153 		}
    154 		p = p->next;
    155 	}
    156 	return NULL;
    157 }
    158 
    159 struct delegpt_addr*
    160 delegpt_find_addr(struct delegpt* dp, struct sockaddr_storage* addr,
    161 	socklen_t addrlen)
    162 {
    163 	struct delegpt_addr* p = dp->target_list;
    164 	while(p) {
    165 		if(sockaddr_cmp_addr(addr, addrlen, &p->addr, p->addrlen)==0
    166 			&& ((struct sockaddr_in*)addr)->sin_port ==
    167 			   ((struct sockaddr_in*)&p->addr)->sin_port) {
    168 			return p;
    169 		}
    170 		p = p->next_target;
    171 	}
    172 	return NULL;
    173 }
    174 
    175 int
    176 delegpt_add_target(struct delegpt* dp, struct regional* region,
    177 	uint8_t* name, size_t namelen, struct sockaddr_storage* addr,
    178 	socklen_t addrlen, uint8_t bogus, uint8_t lame, int* additions)
    179 {
    180 	struct delegpt_ns* ns = delegpt_find_ns(dp, name, namelen);
    181 	log_assert(!dp->dp_type_mlc);
    182 	if(!ns) {
    183 		/* ignore it */
    184 		return 1;
    185 	}
    186 	if(!lame) {
    187 		if(addr_is_ip6(addr, addrlen))
    188 			ns->got6 = 1;
    189 		else	ns->got4 = 1;
    190 		if(ns->got4 && ns->got6)
    191 			ns->resolved = 1;
    192 	} else {
    193 		if(addr_is_ip6(addr, addrlen))
    194 			ns->done_pside6 = 1;
    195 		else	ns->done_pside4 = 1;
    196 	}
    197 	log_assert(ns->port>0);
    198 	return delegpt_add_addr(dp, region, addr, addrlen, bogus, lame,
    199 		ns->tls_auth_name, ns->port, additions);
    200 }
    201 
    202 int
    203 delegpt_add_addr(struct delegpt* dp, struct regional* region,
    204 	struct sockaddr_storage* addr, socklen_t addrlen, uint8_t bogus,
    205 	uint8_t lame, char* tls_auth_name, int port, int* additions)
    206 {
    207 	struct delegpt_addr* a;
    208 	log_assert(!dp->dp_type_mlc);
    209 	if(port != -1) {
    210 		log_assert(port>0);
    211 		sockaddr_store_port(addr, addrlen, port);
    212 	}
    213 	/* check for duplicates */
    214 	if((a = delegpt_find_addr(dp, addr, addrlen))) {
    215 		if(bogus)
    216 			a->bogus = bogus;
    217 		if(!lame)
    218 			a->lame = 0;
    219 		return 1;
    220 	}
    221 	if(additions)
    222 		*additions = 1;
    223 
    224 	a = (struct delegpt_addr*)regional_alloc(region,
    225 		sizeof(struct delegpt_addr));
    226 	if(!a)
    227 		return 0;
    228 	a->next_result = 0;
    229 	memcpy(&a->addr, addr, addrlen);
    230 	a->addrlen = addrlen;
    231 	a->attempts = 0;
    232 	a->bogus = bogus;
    233 	a->lame = lame;
    234 	a->dnsseclame = 0;
    235 	if(tls_auth_name) {
    236 		a->tls_auth_name = regional_strdup(region, tls_auth_name);
    237 		if(!a->tls_auth_name)
    238 			return 0;
    239 	} else {
    240 		a->tls_auth_name = NULL;
    241 	}
    242 	a->next_target = dp->target_list;
    243 	dp->target_list = a;
    244 	a->next_usable = dp->usable_list;
    245 	dp->usable_list = a;
    246 	return 1;
    247 }
    248 
    249 void
    250 delegpt_count_ns(struct delegpt* dp, size_t* numns, size_t* missing)
    251 {
    252 	struct delegpt_ns* ns;
    253 	*numns = 0;
    254 	*missing = 0;
    255 	for(ns = dp->nslist; ns; ns = ns->next) {
    256 		(*numns)++;
    257 		if(!ns->resolved)
    258 			(*missing)++;
    259 	}
    260 }
    261 
    262 void
    263 delegpt_count_addr(struct delegpt* dp, size_t* numaddr, size_t* numres,
    264 	size_t* numavail)
    265 {
    266 	struct delegpt_addr* a;
    267 	*numaddr = 0;
    268 	*numres = 0;
    269 	*numavail = 0;
    270 	for(a = dp->target_list; a; a = a->next_target) {
    271 		(*numaddr)++;
    272 	}
    273 	for(a = dp->result_list; a; a = a->next_result) {
    274 		(*numres)++;
    275 	}
    276 	for(a = dp->usable_list; a; a = a->next_usable) {
    277 		(*numavail)++;
    278 	}
    279 }
    280 
    281 void delegpt_log(enum verbosity_value v, struct delegpt* dp)
    282 {
    283 	char buf[LDNS_MAX_DOMAINLEN];
    284 	struct delegpt_ns* ns;
    285 	struct delegpt_addr* a;
    286 	size_t missing=0, numns=0, numaddr=0, numres=0, numavail=0;
    287 	if(verbosity < v)
    288 		return;
    289 	dname_str(dp->name, buf);
    290 	if(dp->nslist == NULL && dp->target_list == NULL) {
    291 		log_info("DelegationPoint<%s>: empty", buf);
    292 		return;
    293 	}
    294 	delegpt_count_ns(dp, &numns, &missing);
    295 	delegpt_count_addr(dp, &numaddr, &numres, &numavail);
    296 	log_info("DelegationPoint<%s>: %u names (%u missing), "
    297 		"%u addrs (%u result, %u avail)%s",
    298 		buf, (unsigned)numns, (unsigned)missing,
    299 		(unsigned)numaddr, (unsigned)numres, (unsigned)numavail,
    300 		(dp->has_parent_side_NS?" parentNS":" cacheNS"));
    301 	if(verbosity >= VERB_ALGO) {
    302 		for(ns = dp->nslist; ns; ns = ns->next) {
    303 			dname_str(ns->name, buf);
    304 			log_info("  %s %s%s%s%s%s%s%s", buf,
    305 			(ns->resolved?"*":""),
    306 			(ns->got4?" A":""), (ns->got6?" AAAA":""),
    307 			(dp->bogus?" BOGUS":""), (ns->lame?" PARENTSIDE":""),
    308 			(ns->done_pside4?" PSIDE_A":""),
    309 			(ns->done_pside6?" PSIDE_AAAA":""));
    310 		}
    311 		for(a = dp->target_list; a; a = a->next_target) {
    312 			char s[128];
    313 			const char* str = "  ";
    314 			if(a->bogus && a->lame) str = "  BOGUS ADDR_LAME ";
    315 			else if(a->bogus) str = "  BOGUS ";
    316 			else if(a->lame) str = "  ADDR_LAME ";
    317 			if(a->tls_auth_name)
    318 				snprintf(s, sizeof(s), "%s[%s]", str,
    319 					a->tls_auth_name);
    320 			else snprintf(s, sizeof(s), "%s", str);
    321 			log_addr(VERB_ALGO, s, &a->addr, a->addrlen);
    322 		}
    323 	}
    324 }
    325 
    326 int
    327 delegpt_addr_on_result_list(struct delegpt* dp, struct delegpt_addr* find)
    328 {
    329 	struct delegpt_addr* a = dp->result_list;
    330 	while(a) {
    331 		if(a == find)
    332 			return 1;
    333 		a = a->next_result;
    334 	}
    335 	return 0;
    336 }
    337 
    338 void
    339 delegpt_usable_list_remove_addr(struct delegpt* dp, struct delegpt_addr* del)
    340 {
    341 	struct delegpt_addr* usa = dp->usable_list, *prev = NULL;
    342 	while(usa) {
    343 		if(usa == del) {
    344 			/* snip off the usable list */
    345 			if(prev)
    346 				prev->next_usable = usa->next_usable;
    347 			else	dp->usable_list = usa->next_usable;
    348 			return;
    349 		}
    350 		prev = usa;
    351 		usa = usa->next_usable;
    352 	}
    353 }
    354 
    355 void
    356 delegpt_add_to_result_list(struct delegpt* dp, struct delegpt_addr* a)
    357 {
    358 	if(delegpt_addr_on_result_list(dp, a))
    359 		return;
    360 	delegpt_usable_list_remove_addr(dp, a);
    361 	a->next_result = dp->result_list;
    362 	dp->result_list = a;
    363 }
    364 
    365 void
    366 delegpt_add_unused_targets(struct delegpt* dp)
    367 {
    368 	struct delegpt_addr* usa = dp->usable_list;
    369 	dp->usable_list = NULL;
    370 	while(usa) {
    371 		usa->next_result = dp->result_list;
    372 		dp->result_list = usa;
    373 		usa = usa->next_usable;
    374 	}
    375 }
    376 
    377 size_t
    378 delegpt_count_targets(struct delegpt* dp)
    379 {
    380 	struct delegpt_addr* a;
    381 	size_t n = 0;
    382 	for(a = dp->target_list; a; a = a->next_target)
    383 		n++;
    384 	return n;
    385 }
    386 
    387 size_t
    388 delegpt_count_missing_targets(struct delegpt* dp, int* alllame)
    389 {
    390 	struct delegpt_ns* ns;
    391 	size_t n = 0, nlame = 0;
    392 	for(ns = dp->nslist; ns; ns = ns->next) {
    393 		if(ns->resolved) continue;
    394 		n++;
    395 		if(ns->lame) nlame++;
    396 	}
    397 	if(alllame && n == nlame) *alllame = 1;
    398 	return n;
    399 }
    400 
    401 /** find NS rrset in given list */
    402 static struct ub_packed_rrset_key*
    403 find_NS(struct reply_info* rep, size_t from, size_t to, uint16_t qclass)
    404 {
    405 	size_t i;
    406 	for(i=from; i<to; i++) {
    407 		if(ntohs(rep->rrsets[i]->rk.type) == LDNS_RR_TYPE_NS &&
    408 			ntohs(rep->rrsets[i]->rk.rrset_class) == qclass)
    409 			return rep->rrsets[i];
    410 	}
    411 	return NULL;
    412 }
    413 
    414 struct delegpt*
    415 delegpt_from_message(struct dns_msg* msg, struct regional* region, int port)
    416 {
    417 	struct ub_packed_rrset_key* ns_rrset = NULL;
    418 	struct delegpt* dp;
    419 	size_t i;
    420 	/* look for NS records in the authority section... */
    421 	ns_rrset = find_NS(msg->rep, msg->rep->an_numrrsets,
    422 		msg->rep->an_numrrsets+msg->rep->ns_numrrsets,
    423 		msg->qinfo.qclass);
    424 
    425 	/* In some cases (even legitimate, perfectly legal cases), the
    426 	 * NS set for the "referral" might be in the answer section. */
    427 	if(!ns_rrset)
    428 		ns_rrset = find_NS(msg->rep, 0, msg->rep->an_numrrsets,
    429 			msg->qinfo.qclass);
    430 
    431 	/* If there was no NS rrset in the authority section, then this
    432 	 * wasn't a referral message. (It might not actually be a
    433 	 * referral message anyway) */
    434 	if(!ns_rrset)
    435 		return NULL;
    436 
    437 	/* If we found any, then Yay! we have a delegation point. */
    438 	dp = delegpt_create(region);
    439 	if(!dp)
    440 		return NULL;
    441 	dp->has_parent_side_NS = 1; /* created from message */
    442 	if(!delegpt_set_name(dp, region, ns_rrset->rk.dname))
    443 		return NULL;
    444 	if(!delegpt_rrset_add_ns(dp, region, ns_rrset, 0, port))
    445 		return NULL;
    446 
    447 	/* add glue, A and AAAA in answer and additional section */
    448 	for(i=0; i<msg->rep->rrset_count; i++) {
    449 		struct ub_packed_rrset_key* s = msg->rep->rrsets[i];
    450 		/* skip auth section. FIXME really needed?*/
    451 		if(msg->rep->an_numrrsets <= i &&
    452 			i < (msg->rep->an_numrrsets+msg->rep->ns_numrrsets))
    453 			continue;
    454 
    455 		if(ntohs(s->rk.type) == LDNS_RR_TYPE_A &&
    456 			ntohs(s->rk.rrset_class) == msg->qinfo.qclass) {
    457 			if(!delegpt_add_rrset_A(dp, region, s, 0, NULL))
    458 				return NULL;
    459 		} else if(ntohs(s->rk.type) == LDNS_RR_TYPE_AAAA &&
    460 			ntohs(s->rk.rrset_class) == msg->qinfo.qclass) {
    461 			if(!delegpt_add_rrset_AAAA(dp, region, s, 0, NULL))
    462 				return NULL;
    463 		}
    464 	}
    465 	return dp;
    466 }
    467 
    468 int
    469 delegpt_rrset_add_ns(struct delegpt* dp, struct regional* region,
    470         struct ub_packed_rrset_key* ns_rrset, uint8_t lame, int port)
    471 {
    472 	struct packed_rrset_data* nsdata = (struct packed_rrset_data*)
    473 		ns_rrset->entry.data;
    474 	size_t i;
    475 	log_assert(!dp->dp_type_mlc);
    476 	if(nsdata->security == sec_status_bogus)
    477 		dp->bogus = 1;
    478 	for(i=0; i<nsdata->count; i++) {
    479 		if(nsdata->rr_len[i] < 2+1) continue; /* len + root label */
    480 		if(dname_valid(nsdata->rr_data[i]+2, nsdata->rr_len[i]-2) !=
    481 			(size_t)sldns_read_uint16(nsdata->rr_data[i]))
    482 			continue; /* bad format */
    483 		/* add rdata of NS (= wirefmt dname), skip rdatalen bytes */
    484 		if(!delegpt_add_ns(dp, region, nsdata->rr_data[i]+2, lame,
    485 			NULL, (port==-1?UNBOUND_DNS_PORT:port)))
    486 			return 0;
    487 	}
    488 	return 1;
    489 }
    490 
    491 int
    492 delegpt_add_rrset_A(struct delegpt* dp, struct regional* region,
    493 	struct ub_packed_rrset_key* ak, uint8_t lame, int* additions)
    494 {
    495         struct packed_rrset_data* d=(struct packed_rrset_data*)ak->entry.data;
    496         size_t i;
    497         struct sockaddr_in sa;
    498         socklen_t len = (socklen_t)sizeof(sa);
    499 	log_assert(!dp->dp_type_mlc);
    500         memset(&sa, 0, len);
    501         sa.sin_family = AF_INET;
    502         for(i=0; i<d->count; i++) {
    503                 if(d->rr_len[i] != 2 + INET_SIZE)
    504                         continue;
    505                 memmove(&sa.sin_addr, d->rr_data[i]+2, INET_SIZE);
    506                 if(!delegpt_add_target(dp, region, ak->rk.dname,
    507                         ak->rk.dname_len, (struct sockaddr_storage*)&sa,
    508                         len, (d->security==sec_status_bogus), lame, additions))
    509                         return 0;
    510         }
    511         return 1;
    512 }
    513 
    514 int
    515 delegpt_add_rrset_AAAA(struct delegpt* dp, struct regional* region,
    516 	struct ub_packed_rrset_key* ak, uint8_t lame, int* additions)
    517 {
    518         struct packed_rrset_data* d=(struct packed_rrset_data*)ak->entry.data;
    519         size_t i;
    520         struct sockaddr_in6 sa;
    521         socklen_t len = (socklen_t)sizeof(sa);
    522 	log_assert(!dp->dp_type_mlc);
    523         memset(&sa, 0, len);
    524         sa.sin6_family = AF_INET6;
    525         for(i=0; i<d->count; i++) {
    526                 if(d->rr_len[i] != 2 + INET6_SIZE) /* rdatalen + len of IP6 */
    527                         continue;
    528                 memmove(&sa.sin6_addr, d->rr_data[i]+2, INET6_SIZE);
    529                 if(!delegpt_add_target(dp, region, ak->rk.dname,
    530                         ak->rk.dname_len, (struct sockaddr_storage*)&sa,
    531                         len, (d->security==sec_status_bogus), lame, additions))
    532                         return 0;
    533         }
    534         return 1;
    535 }
    536 
    537 int
    538 delegpt_add_rrset(struct delegpt* dp, struct regional* region,
    539         struct ub_packed_rrset_key* rrset, uint8_t lame, int* additions)
    540 {
    541 	if(!rrset)
    542 		return 1;
    543 	if(ntohs(rrset->rk.type) == LDNS_RR_TYPE_NS)
    544 		return delegpt_rrset_add_ns(dp, region, rrset, lame, -1);
    545 	else if(ntohs(rrset->rk.type) == LDNS_RR_TYPE_A)
    546 		return delegpt_add_rrset_A(dp, region, rrset, lame, additions);
    547 	else if(ntohs(rrset->rk.type) == LDNS_RR_TYPE_AAAA)
    548 		return delegpt_add_rrset_AAAA(dp, region, rrset, lame,
    549 			additions);
    550 	log_warn("Unknown rrset type added to delegpt");
    551 	return 1;
    552 }
    553 
    554 void delegpt_mark_neg(struct delegpt_ns* ns, uint16_t qtype)
    555 {
    556 	if(ns) {
    557 		if(qtype == LDNS_RR_TYPE_A)
    558 			ns->got4 = 2;
    559 		else if(qtype == LDNS_RR_TYPE_AAAA)
    560 			ns->got6 = 2;
    561 		if(ns->got4 && ns->got6)
    562 			ns->resolved = 1;
    563 	}
    564 }
    565 
    566 void delegpt_add_neg_msg(struct delegpt* dp, struct msgreply_entry* msg)
    567 {
    568 	struct reply_info* rep = (struct reply_info*)msg->entry.data;
    569 	if(!rep) return;
    570 
    571 	/* if error or no answers */
    572 	if(FLAGS_GET_RCODE(rep->flags) != 0 || rep->an_numrrsets == 0) {
    573 		struct delegpt_ns* ns = delegpt_find_ns(dp, msg->key.qname,
    574 			msg->key.qname_len);
    575 		delegpt_mark_neg(ns, msg->key.qtype);
    576 	}
    577 }
    578 
    579 void delegpt_no_ipv6(struct delegpt* dp)
    580 {
    581 	struct delegpt_ns* ns;
    582 	for(ns = dp->nslist; ns; ns = ns->next) {
    583 		/* no ipv6, so only ipv4 is enough to resolve a nameserver */
    584 		if(ns->got4)
    585 			ns->resolved = 1;
    586 	}
    587 }
    588 
    589 void delegpt_no_ipv4(struct delegpt* dp)
    590 {
    591 	struct delegpt_ns* ns;
    592 	for(ns = dp->nslist; ns; ns = ns->next) {
    593 		/* no ipv4, so only ipv6 is enough to resolve a nameserver */
    594 		if(ns->got6)
    595 			ns->resolved = 1;
    596 	}
    597 }
    598 
    599 struct delegpt* delegpt_create_mlc(uint8_t* name)
    600 {
    601 	struct delegpt* dp=(struct delegpt*)calloc(1, sizeof(*dp));
    602 	if(!dp)
    603 		return NULL;
    604 	dp->dp_type_mlc = 1;
    605 	if(name) {
    606 		dp->namelabs = dname_count_size_labels(name, &dp->namelen);
    607 		dp->name = memdup(name, dp->namelen);
    608 		if(!dp->name) {
    609 			free(dp);
    610 			return NULL;
    611 		}
    612 	}
    613 	return dp;
    614 }
    615 
    616 void delegpt_free_mlc(struct delegpt* dp)
    617 {
    618 	struct delegpt_ns* n, *nn;
    619 	struct delegpt_addr* a, *na;
    620 	if(!dp) return;
    621 	log_assert(dp->dp_type_mlc);
    622 	n = dp->nslist;
    623 	while(n) {
    624 		nn = n->next;
    625 		free(n->name);
    626 		free(n->tls_auth_name);
    627 		free(n);
    628 		n = nn;
    629 	}
    630 	a = dp->target_list;
    631 	while(a) {
    632 		na = a->next_target;
    633 		free(a->tls_auth_name);
    634 		free(a);
    635 		a = na;
    636 	}
    637 	free(dp->name);
    638 	free(dp);
    639 }
    640 
    641 int delegpt_set_name_mlc(struct delegpt* dp, uint8_t* name)
    642 {
    643 	log_assert(dp->dp_type_mlc);
    644 	dp->namelabs = dname_count_size_labels(name, &dp->namelen);
    645 	dp->name = memdup(name, dp->namelen);
    646 	return (dp->name != NULL);
    647 }
    648 
    649 int delegpt_add_ns_mlc(struct delegpt* dp, uint8_t* name, uint8_t lame,
    650 	char* tls_auth_name, int port)
    651 {
    652 	struct delegpt_ns* ns;
    653 	size_t len;
    654 	(void)dname_count_size_labels(name, &len);
    655 	log_assert(dp->dp_type_mlc);
    656 	/* slow check for duplicates to avoid counting failures when
    657 	 * adding the same server as a dependency twice */
    658 	if(delegpt_find_ns(dp, name, len))
    659 		return 1;
    660 	ns = (struct delegpt_ns*)malloc(sizeof(struct delegpt_ns));
    661 	if(!ns)
    662 		return 0;
    663 	ns->namelen = len;
    664 	ns->name = memdup(name, ns->namelen);
    665 	if(!ns->name) {
    666 		free(ns);
    667 		return 0;
    668 	}
    669 	ns->cache_lookup_count = 0;
    670 	ns->resolved = 0;
    671 	ns->got4 = 0;
    672 	ns->got6 = 0;
    673 	ns->lame = (uint8_t)lame;
    674 	ns->done_pside4 = 0;
    675 	ns->done_pside6 = 0;
    676 	ns->port = port;
    677 	if(tls_auth_name) {
    678 		ns->tls_auth_name = strdup(tls_auth_name);
    679 		if(!ns->tls_auth_name) {
    680 			free(ns->name);
    681 			free(ns);
    682 			return 0;
    683 		}
    684 	} else {
    685 		ns->tls_auth_name = NULL;
    686 	}
    687 	ns->next = dp->nslist;
    688 	dp->nslist = ns;
    689 	return 1;
    690 }
    691 
    692 int delegpt_add_addr_mlc(struct delegpt* dp, struct sockaddr_storage* addr,
    693 	socklen_t addrlen, uint8_t bogus, uint8_t lame, char* tls_auth_name,
    694 	int port)
    695 {
    696 	struct delegpt_addr* a;
    697 	log_assert(dp->dp_type_mlc);
    698 	if(port != -1) {
    699 		log_assert(port>0);
    700 		sockaddr_store_port(addr, addrlen, port);
    701 	}
    702 	/* check for duplicates */
    703 	if((a = delegpt_find_addr(dp, addr, addrlen))) {
    704 		if(bogus)
    705 			a->bogus = bogus;
    706 		if(!lame)
    707 			a->lame = 0;
    708 		return 1;
    709 	}
    710 
    711 	a = (struct delegpt_addr*)malloc(sizeof(struct delegpt_addr));
    712 	if(!a)
    713 		return 0;
    714 	a->next_result = 0;
    715 	memcpy(&a->addr, addr, addrlen);
    716 	a->addrlen = addrlen;
    717 	a->attempts = 0;
    718 	a->bogus = bogus;
    719 	a->lame = lame;
    720 	a->dnsseclame = 0;
    721 	if(tls_auth_name) {
    722 		a->tls_auth_name = strdup(tls_auth_name);
    723 		if(!a->tls_auth_name) {
    724 			free(a);
    725 			return 0;
    726 		}
    727 	} else {
    728 		a->tls_auth_name = NULL;
    729 	}
    730 	a->next_target = dp->target_list;
    731 	dp->target_list = a;
    732 	a->next_usable = dp->usable_list;
    733 	dp->usable_list = a;
    734 	return 1;
    735 }
    736 
    737 int delegpt_add_target_mlc(struct delegpt* dp, uint8_t* name, size_t namelen,
    738 	struct sockaddr_storage* addr, socklen_t addrlen, uint8_t bogus,
    739 	uint8_t lame)
    740 {
    741 	struct delegpt_ns* ns = delegpt_find_ns(dp, name, namelen);
    742 	log_assert(dp->dp_type_mlc);
    743 	if(!ns) {
    744 		/* ignore it */
    745 		return 1;
    746 	}
    747 	if(!lame) {
    748 		if(addr_is_ip6(addr, addrlen))
    749 			ns->got6 = 1;
    750 		else	ns->got4 = 1;
    751 		if(ns->got4 && ns->got6)
    752 			ns->resolved = 1;
    753 	} else {
    754 		if(addr_is_ip6(addr, addrlen))
    755 			ns->done_pside6 = 1;
    756 		else	ns->done_pside4 = 1;
    757 	}
    758 	log_assert(ns->port>0);
    759 	return delegpt_add_addr_mlc(dp, addr, addrlen, bogus, lame,
    760 		ns->tls_auth_name, ns->port);
    761 }
    762 
    763 size_t delegpt_get_mem(struct delegpt* dp)
    764 {
    765 	struct delegpt_ns* ns;
    766 	size_t s;
    767 	if(!dp) return 0;
    768 	s = sizeof(*dp) + dp->namelen +
    769 		delegpt_count_targets(dp)*sizeof(struct delegpt_addr);
    770 	for(ns=dp->nslist; ns; ns=ns->next)
    771 		s += sizeof(*ns)+ns->namelen;
    772 	return s;
    773 }
    774