1 /*
2 * iterator/iter_utils.c - iterative resolver module utility functions.
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 contains functions to assist the iterator module.
40 * Configuration options. Forward zones.
41 */
42 #include "config.h"
43 #include "iterator/iter_utils.h"
44 #include "iterator/iterator.h"
45 #include "iterator/iter_hints.h"
46 #include "iterator/iter_fwd.h"
47 #include "iterator/iter_donotq.h"
48 #include "iterator/iter_delegpt.h"
49 #include "iterator/iter_priv.h"
50 #include "services/cache/infra.h"
51 #include "services/cache/dns.h"
52 #include "services/cache/rrset.h"
53 #include "services/outside_network.h"
54 #include "util/net_help.h"
55 #include "util/module.h"
56 #include "util/log.h"
57 #include "util/config_file.h"
58 #include "util/regional.h"
59 #include "util/data/msgparse.h"
60 #include "util/data/dname.h"
61 #include "util/random.h"
62 #include "util/fptr_wlist.h"
63 #include "validator/val_anchor.h"
64 #include "validator/val_kcache.h"
65 #include "validator/val_kentry.h"
66 #include "validator/val_utils.h"
67 #include "validator/val_sigcrypt.h"
68 #include "sldns/sbuffer.h"
69 #include "sldns/str2wire.h"
70
71 /** time when nameserver glue is said to be 'recent' */
72 #define SUSPICION_RECENT_EXPIRY 86400
73 /** penalty to validation failed blacklisted IPs */
74 #define BLACKLIST_PENALTY (USEFUL_SERVER_TOP_TIMEOUT*4)
75
76 /** fillup fetch policy array */
77 static void
fetch_fill(struct iter_env * ie,const char * str)78 fetch_fill(struct iter_env* ie, const char* str)
79 {
80 char* s = (char*)str, *e;
81 int i;
82 for(i=0; i<ie->max_dependency_depth+1; i++) {
83 ie->target_fetch_policy[i] = strtol(s, &e, 10);
84 if(s == e)
85 fatal_exit("cannot parse fetch policy number %s", s);
86 s = e;
87 }
88 }
89
90 /** Read config string that represents the target fetch policy */
91 static int
read_fetch_policy(struct iter_env * ie,const char * str)92 read_fetch_policy(struct iter_env* ie, const char* str)
93 {
94 int count = cfg_count_numbers(str);
95 if(count < 1) {
96 log_err("Cannot parse target fetch policy: \"%s\"", str);
97 return 0;
98 }
99 ie->max_dependency_depth = count - 1;
100 ie->target_fetch_policy = (int*)calloc(
101 (size_t)ie->max_dependency_depth+1, sizeof(int));
102 if(!ie->target_fetch_policy) {
103 log_err("alloc fetch policy: out of memory");
104 return 0;
105 }
106 fetch_fill(ie, str);
107 return 1;
108 }
109
110 /** apply config caps whitelist items to name tree */
111 static int
caps_white_apply_cfg(rbtree_type * ntree,struct config_file * cfg)112 caps_white_apply_cfg(rbtree_type* ntree, struct config_file* cfg)
113 {
114 struct config_strlist* p;
115 for(p=cfg->caps_whitelist; p; p=p->next) {
116 struct name_tree_node* n;
117 size_t len;
118 uint8_t* nm = sldns_str2wire_dname(p->str, &len);
119 if(!nm) {
120 log_err("could not parse %s", p->str);
121 return 0;
122 }
123 n = (struct name_tree_node*)calloc(1, sizeof(*n));
124 if(!n) {
125 log_err("out of memory");
126 free(nm);
127 return 0;
128 }
129 n->node.key = n;
130 n->name = nm;
131 n->len = len;
132 n->labs = dname_count_labels(nm);
133 n->dclass = LDNS_RR_CLASS_IN;
134 if(!name_tree_insert(ntree, n, nm, len, n->labs, n->dclass)) {
135 /* duplicate element ignored, idempotent */
136 free(n->name);
137 free(n);
138 }
139 }
140 name_tree_init_parents(ntree);
141 return 1;
142 }
143
144 int
iter_apply_cfg(struct iter_env * iter_env,struct config_file * cfg)145 iter_apply_cfg(struct iter_env* iter_env, struct config_file* cfg)
146 {
147 int i;
148 /* target fetch policy */
149 if(!read_fetch_policy(iter_env, cfg->target_fetch_policy))
150 return 0;
151 for(i=0; i<iter_env->max_dependency_depth+1; i++)
152 verbose(VERB_QUERY, "target fetch policy for level %d is %d",
153 i, iter_env->target_fetch_policy[i]);
154
155 if(!iter_env->donotq)
156 iter_env->donotq = donotq_create();
157 if(!iter_env->donotq || !donotq_apply_cfg(iter_env->donotq, cfg)) {
158 log_err("Could not set donotqueryaddresses");
159 return 0;
160 }
161 if(!iter_env->priv)
162 iter_env->priv = priv_create();
163 if(!iter_env->priv || !priv_apply_cfg(iter_env->priv, cfg)) {
164 log_err("Could not set private addresses");
165 return 0;
166 }
167 if(cfg->caps_whitelist) {
168 if(!iter_env->caps_white)
169 iter_env->caps_white = rbtree_create(name_tree_compare);
170 if(!iter_env->caps_white || !caps_white_apply_cfg(
171 iter_env->caps_white, cfg)) {
172 log_err("Could not set capsforid whitelist");
173 return 0;
174 }
175
176 }
177 iter_env->supports_ipv6 = cfg->do_ip6;
178 iter_env->supports_ipv4 = cfg->do_ip4;
179 iter_env->outbound_msg_retry = cfg->outbound_msg_retry;
180 return 1;
181 }
182
183 /** filter out unsuitable targets
184 * @param iter_env: iterator environment with ipv6-support flag.
185 * @param env: module environment with infra cache.
186 * @param name: zone name
187 * @param namelen: length of name
188 * @param qtype: query type (host order).
189 * @param now: current time
190 * @param a: address in delegation point we are examining.
191 * @return an integer that signals the target suitability.
192 * as follows:
193 * -1: The address should be omitted from the list.
194 * Because:
195 * o The address is bogus (DNSSEC validation failure).
196 * o Listed as donotquery
197 * o is ipv6 but no ipv6 support (in operating system).
198 * o is ipv4 but no ipv4 support (in operating system).
199 * o is lame
200 * Otherwise, an rtt in milliseconds.
201 * 0 .. USEFUL_SERVER_TOP_TIMEOUT-1
202 * The roundtrip time timeout estimate. less than 2 minutes.
203 * Note that util/rtt.c has a MIN_TIMEOUT of 50 msec, thus
204 * values 0 .. 49 are not used, unless that is changed.
205 * USEFUL_SERVER_TOP_TIMEOUT
206 * This value exactly is given for unresponsive blacklisted.
207 * USEFUL_SERVER_TOP_TIMEOUT+1
208 * For non-blacklisted servers: huge timeout, but has traffic.
209 * USEFUL_SERVER_TOP_TIMEOUT*1 ..
210 * parent-side lame servers get this penalty. A dispreferential
211 * server. (lame in delegpt).
212 * USEFUL_SERVER_TOP_TIMEOUT*2 ..
213 * dnsseclame servers get penalty
214 * USEFUL_SERVER_TOP_TIMEOUT*3 ..
215 * recursion lame servers get penalty
216 * UNKNOWN_SERVER_NICENESS
217 * If no information is known about the server, this is
218 * returned. 376 msec or so.
219 * +BLACKLIST_PENALTY (of USEFUL_TOP_TIMEOUT*4) for dnssec failed IPs.
220 *
221 * When a final value is chosen that is dnsseclame ; dnsseclameness checking
222 * is turned off (so we do not discard the reply).
223 * When a final value is chosen that is recursionlame; RD bit is set on query.
224 * Because of the numbers this means recursionlame also have dnssec lameness
225 * checking turned off.
226 */
227 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)228 iter_filter_unsuitable(struct iter_env* iter_env, struct module_env* env,
229 uint8_t* name, size_t namelen, uint16_t qtype, time_t now,
230 struct delegpt_addr* a)
231 {
232 int rtt, lame, reclame, dnsseclame;
233 if(a->bogus)
234 return -1; /* address of server is bogus */
235 if(donotq_lookup(iter_env->donotq, &a->addr, a->addrlen)) {
236 log_addr(VERB_ALGO, "skip addr on the donotquery list",
237 &a->addr, a->addrlen);
238 return -1; /* server is on the donotquery list */
239 }
240 if(!iter_env->supports_ipv6 && addr_is_ip6(&a->addr, a->addrlen)) {
241 return -1; /* there is no ip6 available */
242 }
243 if(!iter_env->supports_ipv4 && !addr_is_ip6(&a->addr, a->addrlen)) {
244 return -1; /* there is no ip4 available */
245 }
246 /* check lameness - need zone , class info */
247 if(infra_get_lame_rtt(env->infra_cache, &a->addr, a->addrlen,
248 name, namelen, qtype, &lame, &dnsseclame, &reclame,
249 &rtt, now)) {
250 log_addr(VERB_ALGO, "servselect", &a->addr, a->addrlen);
251 verbose(VERB_ALGO, " rtt=%d%s%s%s%s", rtt,
252 lame?" LAME":"",
253 dnsseclame?" DNSSEC_LAME":"",
254 reclame?" REC_LAME":"",
255 a->lame?" ADDR_LAME":"");
256 if(lame)
257 return -1; /* server is lame */
258 else if(rtt >= USEFUL_SERVER_TOP_TIMEOUT)
259 /* server is unresponsive,
260 * we used to return TOP_TIMEOUT, but fairly useless,
261 * because if == TOP_TIMEOUT is dropped because
262 * blacklisted later, instead, remove it here, so
263 * other choices (that are not blacklisted) can be
264 * tried */
265 return -1;
266 /* select remainder from worst to best */
267 else if(reclame)
268 return rtt+USEFUL_SERVER_TOP_TIMEOUT*3; /* nonpref */
269 else if(dnsseclame || a->dnsseclame)
270 return rtt+USEFUL_SERVER_TOP_TIMEOUT*2; /* nonpref */
271 else if(a->lame)
272 return rtt+USEFUL_SERVER_TOP_TIMEOUT+1; /* nonpref */
273 else return rtt;
274 }
275 /* no server information present */
276 if(a->dnsseclame)
277 return UNKNOWN_SERVER_NICENESS+USEFUL_SERVER_TOP_TIMEOUT*2; /* nonpref */
278 else if(a->lame)
279 return USEFUL_SERVER_TOP_TIMEOUT+1+UNKNOWN_SERVER_NICENESS; /* nonpref */
280 return UNKNOWN_SERVER_NICENESS;
281 }
282
283 /** lookup RTT information, and also store fastest rtt (if any) */
284 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,size_t * num_suitable_results)285 iter_fill_rtt(struct iter_env* iter_env, struct module_env* env,
286 uint8_t* name, size_t namelen, uint16_t qtype, time_t now,
287 struct delegpt* dp, int* best_rtt, struct sock_list* blacklist,
288 size_t* num_suitable_results)
289 {
290 int got_it = 0;
291 struct delegpt_addr* a;
292 *num_suitable_results = 0;
293
294 if(dp->bogus)
295 return 0; /* NS bogus, all bogus, nothing found */
296 for(a=dp->result_list; a; a = a->next_result) {
297 a->sel_rtt = iter_filter_unsuitable(iter_env, env,
298 name, namelen, qtype, now, a);
299 if(a->sel_rtt != -1) {
300 if(sock_list_find(blacklist, &a->addr, a->addrlen))
301 a->sel_rtt += BLACKLIST_PENALTY;
302
303 if(!got_it) {
304 *best_rtt = a->sel_rtt;
305 got_it = 1;
306 } else if(a->sel_rtt < *best_rtt) {
307 *best_rtt = a->sel_rtt;
308 }
309 (*num_suitable_results)++;
310 }
311 }
312 return got_it;
313 }
314
315 /** compare two rtts, return -1, 0 or 1 */
316 static int
rtt_compare(const void * x,const void * y)317 rtt_compare(const void* x, const void* y)
318 {
319 if(*(int*)x == *(int*)y)
320 return 0;
321 if(*(int*)x > *(int*)y)
322 return 1;
323 return -1;
324 }
325
326 /** get RTT for the Nth fastest server */
327 static int
nth_rtt(struct delegpt_addr * result_list,size_t num_results,size_t n)328 nth_rtt(struct delegpt_addr* result_list, size_t num_results, size_t n)
329 {
330 int rtt_band;
331 size_t i;
332 int* rtt_list, *rtt_index;
333
334 if(num_results < 1 || n >= num_results) {
335 return -1;
336 }
337
338 rtt_list = calloc(num_results, sizeof(int));
339 if(!rtt_list) {
340 log_err("malloc failure: allocating rtt_list");
341 return -1;
342 }
343 rtt_index = rtt_list;
344
345 for(i=0; i<num_results && result_list; i++) {
346 if(result_list->sel_rtt != -1) {
347 *rtt_index = result_list->sel_rtt;
348 rtt_index++;
349 }
350 result_list=result_list->next_result;
351 }
352 qsort(rtt_list, num_results, sizeof(*rtt_list), rtt_compare);
353
354 log_assert(n > 0);
355 rtt_band = rtt_list[n-1];
356 free(rtt_list);
357
358 return rtt_band;
359 }
360
361 /** filter the address list, putting best targets at front,
362 * returns number of best targets (or 0, no suitable targets) */
363 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,time_t prefetch)364 iter_filter_order(struct iter_env* iter_env, struct module_env* env,
365 uint8_t* name, size_t namelen, uint16_t qtype, time_t now,
366 struct delegpt* dp, int* selected_rtt, int open_target,
367 struct sock_list* blacklist, time_t prefetch)
368 {
369 int got_num = 0, low_rtt = 0, swap_to_front, rtt_band = RTT_BAND, nth;
370 size_t num_results;
371 struct delegpt_addr* a, *n, *prev=NULL;
372
373 /* fillup sel_rtt and find best rtt in the bunch */
374 got_num = iter_fill_rtt(iter_env, env, name, namelen, qtype, now, dp,
375 &low_rtt, blacklist, &num_results);
376 if(got_num == 0)
377 return 0;
378 if(low_rtt >= USEFUL_SERVER_TOP_TIMEOUT &&
379 (delegpt_count_missing_targets(dp) > 0 || open_target > 0)) {
380 verbose(VERB_ALGO, "Bad choices, trying to get more choice");
381 return 0; /* we want more choice. The best choice is a bad one.
382 return 0 to force the caller to fetch more */
383 }
384
385 if(env->cfg->fast_server_permil != 0 && prefetch == 0 &&
386 num_results > env->cfg->fast_server_num &&
387 ub_random_max(env->rnd, 1000) < env->cfg->fast_server_permil) {
388 /* the query is not prefetch, but for a downstream client,
389 * there are more servers available then the fastest N we want
390 * to choose from. Limit our choice to the fastest servers. */
391 nth = nth_rtt(dp->result_list, num_results,
392 env->cfg->fast_server_num);
393 if(nth > 0) {
394 rtt_band = nth - low_rtt;
395 if(rtt_band > RTT_BAND)
396 rtt_band = RTT_BAND;
397 }
398 }
399
400 got_num = 0;
401 a = dp->result_list;
402 while(a) {
403 /* skip unsuitable targets */
404 if(a->sel_rtt == -1) {
405 prev = a;
406 a = a->next_result;
407 continue;
408 }
409 /* classify the server address and determine what to do */
410 swap_to_front = 0;
411 if(a->sel_rtt >= low_rtt && a->sel_rtt - low_rtt <= rtt_band) {
412 got_num++;
413 swap_to_front = 1;
414 } else if(a->sel_rtt<low_rtt && low_rtt-a->sel_rtt<=rtt_band) {
415 got_num++;
416 swap_to_front = 1;
417 }
418 /* swap to front if necessary, or move to next result */
419 if(swap_to_front && prev) {
420 n = a->next_result;
421 prev->next_result = n;
422 a->next_result = dp->result_list;
423 dp->result_list = a;
424 a = n;
425 } else {
426 prev = a;
427 a = a->next_result;
428 }
429 }
430 *selected_rtt = low_rtt;
431
432 if (env->cfg->prefer_ip6) {
433 int got_num6 = 0;
434 int low_rtt6 = 0;
435 int i;
436 int attempt = -1; /* filter to make sure addresses have
437 less attempts on them than the first, to force round
438 robin when all the IPv6 addresses fail */
439 int num4ok = 0; /* number ip4 at low attempt count */
440 int num4_lowrtt = 0;
441 prev = NULL;
442 a = dp->result_list;
443 for(i = 0; i < got_num; i++) {
444 if(!a) break; /* robustness */
445 swap_to_front = 0;
446 if(a->addr.ss_family != AF_INET6 && attempt == -1) {
447 /* if we only have ip4 at low attempt count,
448 * then ip6 is failing, and we need to
449 * select one of the remaining IPv4 addrs */
450 attempt = a->attempts;
451 num4ok++;
452 num4_lowrtt = a->sel_rtt;
453 } else if(a->addr.ss_family != AF_INET6 && attempt == a->attempts) {
454 num4ok++;
455 if(num4_lowrtt == 0 || a->sel_rtt < num4_lowrtt) {
456 num4_lowrtt = a->sel_rtt;
457 }
458 }
459 if(a->addr.ss_family == AF_INET6) {
460 if(attempt == -1) {
461 attempt = a->attempts;
462 } else if(a->attempts > attempt) {
463 break;
464 }
465 got_num6++;
466 swap_to_front = 1;
467 if(low_rtt6 == 0 || a->sel_rtt < low_rtt6) {
468 low_rtt6 = a->sel_rtt;
469 }
470 }
471 /* swap to front if IPv6, or move to next result */
472 if(swap_to_front && prev) {
473 n = a->next_result;
474 prev->next_result = n;
475 a->next_result = dp->result_list;
476 dp->result_list = a;
477 a = n;
478 } else {
479 prev = a;
480 a = a->next_result;
481 }
482 }
483 if(got_num6 > 0) {
484 got_num = got_num6;
485 *selected_rtt = low_rtt6;
486 } else if(num4ok > 0) {
487 got_num = num4ok;
488 *selected_rtt = num4_lowrtt;
489 }
490 } else if (env->cfg->prefer_ip4) {
491 int got_num4 = 0;
492 int low_rtt4 = 0;
493 int i;
494 int attempt = -1; /* filter to make sure addresses have
495 less attempts on them than the first, to force round
496 robin when all the IPv4 addresses fail */
497 int num6ok = 0; /* number ip6 at low attempt count */
498 int num6_lowrtt = 0;
499 prev = NULL;
500 a = dp->result_list;
501 for(i = 0; i < got_num; i++) {
502 if(!a) break; /* robustness */
503 swap_to_front = 0;
504 if(a->addr.ss_family != AF_INET && attempt == -1) {
505 /* if we only have ip6 at low attempt count,
506 * then ip4 is failing, and we need to
507 * select one of the remaining IPv6 addrs */
508 attempt = a->attempts;
509 num6ok++;
510 num6_lowrtt = a->sel_rtt;
511 } else if(a->addr.ss_family != AF_INET && attempt == a->attempts) {
512 num6ok++;
513 if(num6_lowrtt == 0 || a->sel_rtt < num6_lowrtt) {
514 num6_lowrtt = a->sel_rtt;
515 }
516 }
517 if(a->addr.ss_family == AF_INET) {
518 if(attempt == -1) {
519 attempt = a->attempts;
520 } else if(a->attempts > attempt) {
521 break;
522 }
523 got_num4++;
524 swap_to_front = 1;
525 if(low_rtt4 == 0 || a->sel_rtt < low_rtt4) {
526 low_rtt4 = a->sel_rtt;
527 }
528 }
529 /* swap to front if IPv4, or move to next result */
530 if(swap_to_front && prev) {
531 n = a->next_result;
532 prev->next_result = n;
533 a->next_result = dp->result_list;
534 dp->result_list = a;
535 a = n;
536 } else {
537 prev = a;
538 a = a->next_result;
539 }
540 }
541 if(got_num4 > 0) {
542 got_num = got_num4;
543 *selected_rtt = low_rtt4;
544 } else if(num6ok > 0) {
545 got_num = num6ok;
546 *selected_rtt = num6_lowrtt;
547 }
548 }
549 return got_num;
550 }
551
552 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,time_t prefetch)553 iter_server_selection(struct iter_env* iter_env,
554 struct module_env* env, struct delegpt* dp,
555 uint8_t* name, size_t namelen, uint16_t qtype, int* dnssec_lame,
556 int* chase_to_rd, int open_target, struct sock_list* blacklist,
557 time_t prefetch)
558 {
559 int sel;
560 int selrtt;
561 struct delegpt_addr* a, *prev;
562 int num = iter_filter_order(iter_env, env, name, namelen, qtype,
563 *env->now, dp, &selrtt, open_target, blacklist, prefetch);
564
565 if(num == 0)
566 return NULL;
567 verbose(VERB_ALGO, "selrtt %d", selrtt);
568 if(selrtt > BLACKLIST_PENALTY) {
569 if(selrtt-BLACKLIST_PENALTY > USEFUL_SERVER_TOP_TIMEOUT*3) {
570 verbose(VERB_ALGO, "chase to "
571 "blacklisted recursion lame server");
572 *chase_to_rd = 1;
573 }
574 if(selrtt-BLACKLIST_PENALTY > USEFUL_SERVER_TOP_TIMEOUT*2) {
575 verbose(VERB_ALGO, "chase to "
576 "blacklisted dnssec lame server");
577 *dnssec_lame = 1;
578 }
579 } else {
580 if(selrtt > USEFUL_SERVER_TOP_TIMEOUT*3) {
581 verbose(VERB_ALGO, "chase to recursion lame server");
582 *chase_to_rd = 1;
583 }
584 if(selrtt > USEFUL_SERVER_TOP_TIMEOUT*2) {
585 verbose(VERB_ALGO, "chase to dnssec lame server");
586 *dnssec_lame = 1;
587 }
588 if(selrtt == USEFUL_SERVER_TOP_TIMEOUT) {
589 verbose(VERB_ALGO, "chase to blacklisted lame server");
590 return NULL;
591 }
592 }
593
594 if(num == 1) {
595 a = dp->result_list;
596 if(++a->attempts < iter_env->outbound_msg_retry)
597 return a;
598 dp->result_list = a->next_result;
599 return a;
600 }
601
602 /* randomly select a target from the list */
603 log_assert(num > 1);
604 /* grab secure random number, to pick unexpected server.
605 * also we need it to be threadsafe. */
606 sel = ub_random_max(env->rnd, num);
607 a = dp->result_list;
608 prev = NULL;
609 while(sel > 0 && a) {
610 prev = a;
611 a = a->next_result;
612 sel--;
613 }
614 if(!a) /* robustness */
615 return NULL;
616 if(++a->attempts < iter_env->outbound_msg_retry)
617 return a;
618 /* remove it from the delegation point result list */
619 if(prev)
620 prev->next_result = a->next_result;
621 else dp->result_list = a->next_result;
622 return a;
623 }
624
625 struct dns_msg*
dns_alloc_msg(sldns_buffer * pkt,struct msg_parse * msg,struct regional * region)626 dns_alloc_msg(sldns_buffer* pkt, struct msg_parse* msg,
627 struct regional* region)
628 {
629 struct dns_msg* m = (struct dns_msg*)regional_alloc(region,
630 sizeof(struct dns_msg));
631 if(!m)
632 return NULL;
633 memset(m, 0, sizeof(*m));
634 if(!parse_create_msg(pkt, msg, NULL, &m->qinfo, &m->rep, region)) {
635 log_err("malloc failure: allocating incoming dns_msg");
636 return NULL;
637 }
638 return m;
639 }
640
641 struct dns_msg*
dns_copy_msg(struct dns_msg * from,struct regional * region)642 dns_copy_msg(struct dns_msg* from, struct regional* region)
643 {
644 struct dns_msg* m = (struct dns_msg*)regional_alloc(region,
645 sizeof(struct dns_msg));
646 if(!m)
647 return NULL;
648 m->qinfo = from->qinfo;
649 if(!(m->qinfo.qname = regional_alloc_init(region, from->qinfo.qname,
650 from->qinfo.qname_len)))
651 return NULL;
652 if(!(m->rep = reply_info_copy(from->rep, NULL, region)))
653 return NULL;
654 return m;
655 }
656
657 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,uint16_t flags)658 iter_dns_store(struct module_env* env, struct query_info* msgqinf,
659 struct reply_info* msgrep, int is_referral, time_t leeway, int pside,
660 struct regional* region, uint16_t flags)
661 {
662 if(!dns_cache_store(env, msgqinf, msgrep, is_referral, leeway,
663 pside, region, flags))
664 log_err("out of memory: cannot store data in cache");
665 }
666
667 int
iter_ns_probability(struct ub_randstate * rnd,int n,int m)668 iter_ns_probability(struct ub_randstate* rnd, int n, int m)
669 {
670 int sel;
671 if(n == m) /* 100% chance */
672 return 1;
673 /* we do not need secure random numbers here, but
674 * we do need it to be threadsafe, so we use this */
675 sel = ub_random_max(rnd, m);
676 return (sel < n);
677 }
678
679 /** detect dependency cycle for query and target */
680 static int
causes_cycle(struct module_qstate * qstate,uint8_t * name,size_t namelen,uint16_t t,uint16_t c)681 causes_cycle(struct module_qstate* qstate, uint8_t* name, size_t namelen,
682 uint16_t t, uint16_t c)
683 {
684 struct query_info qinf;
685 qinf.qname = name;
686 qinf.qname_len = namelen;
687 qinf.qtype = t;
688 qinf.qclass = c;
689 qinf.local_alias = NULL;
690 fptr_ok(fptr_whitelist_modenv_detect_cycle(
691 qstate->env->detect_cycle));
692 return (*qstate->env->detect_cycle)(qstate, &qinf,
693 (uint16_t)(BIT_RD|BIT_CD), qstate->is_priming,
694 qstate->is_valrec);
695 }
696
697 void
iter_mark_cycle_targets(struct module_qstate * qstate,struct delegpt * dp)698 iter_mark_cycle_targets(struct module_qstate* qstate, struct delegpt* dp)
699 {
700 struct delegpt_ns* ns;
701 for(ns = dp->nslist; ns; ns = ns->next) {
702 if(ns->resolved)
703 continue;
704 /* see if this ns as target causes dependency cycle */
705 if(causes_cycle(qstate, ns->name, ns->namelen,
706 LDNS_RR_TYPE_AAAA, qstate->qinfo.qclass) ||
707 causes_cycle(qstate, ns->name, ns->namelen,
708 LDNS_RR_TYPE_A, qstate->qinfo.qclass)) {
709 log_nametypeclass(VERB_QUERY, "skipping target due "
710 "to dependency cycle (harden-glue: no may "
711 "fix some of the cycles)",
712 ns->name, LDNS_RR_TYPE_A,
713 qstate->qinfo.qclass);
714 ns->resolved = 1;
715 }
716 }
717 }
718
719 void
iter_mark_pside_cycle_targets(struct module_qstate * qstate,struct delegpt * dp)720 iter_mark_pside_cycle_targets(struct module_qstate* qstate, struct delegpt* dp)
721 {
722 struct delegpt_ns* ns;
723 for(ns = dp->nslist; ns; ns = ns->next) {
724 if(ns->done_pside4 && ns->done_pside6)
725 continue;
726 /* see if this ns as target causes dependency cycle */
727 if(causes_cycle(qstate, ns->name, ns->namelen,
728 LDNS_RR_TYPE_A, qstate->qinfo.qclass)) {
729 log_nametypeclass(VERB_QUERY, "skipping target due "
730 "to dependency cycle", ns->name,
731 LDNS_RR_TYPE_A, qstate->qinfo.qclass);
732 ns->done_pside4 = 1;
733 }
734 if(causes_cycle(qstate, ns->name, ns->namelen,
735 LDNS_RR_TYPE_AAAA, qstate->qinfo.qclass)) {
736 log_nametypeclass(VERB_QUERY, "skipping target due "
737 "to dependency cycle", ns->name,
738 LDNS_RR_TYPE_AAAA, qstate->qinfo.qclass);
739 ns->done_pside6 = 1;
740 }
741 }
742 }
743
744 int
iter_dp_is_useless(struct query_info * qinfo,uint16_t qflags,struct delegpt * dp)745 iter_dp_is_useless(struct query_info* qinfo, uint16_t qflags,
746 struct delegpt* dp)
747 {
748 struct delegpt_ns* ns;
749 /* check:
750 * o RD qflag is on.
751 * o no addresses are provided.
752 * o all NS items are required glue.
753 * OR
754 * o RD qflag is on.
755 * o no addresses are provided.
756 * o the query is for one of the nameservers in dp,
757 * and that nameserver is a glue-name for this dp.
758 */
759 if(!(qflags&BIT_RD))
760 return 0;
761 /* either available or unused targets */
762 if(dp->usable_list || dp->result_list)
763 return 0;
764
765 /* see if query is for one of the nameservers, which is glue */
766 if( (qinfo->qtype == LDNS_RR_TYPE_A ||
767 qinfo->qtype == LDNS_RR_TYPE_AAAA) &&
768 dname_subdomain_c(qinfo->qname, dp->name) &&
769 delegpt_find_ns(dp, qinfo->qname, qinfo->qname_len))
770 return 1;
771
772 for(ns = dp->nslist; ns; ns = ns->next) {
773 if(ns->resolved) /* skip failed targets */
774 continue;
775 if(!dname_subdomain_c(ns->name, dp->name))
776 return 0; /* one address is not required glue */
777 }
778 return 1;
779 }
780
781 int
iter_qname_indicates_dnssec(struct module_env * env,struct query_info * qinfo)782 iter_qname_indicates_dnssec(struct module_env* env, struct query_info *qinfo)
783 {
784 struct trust_anchor* a;
785 if(!env || !env->anchors || !qinfo || !qinfo->qname)
786 return 0;
787 /* a trust anchor exists above the name? */
788 if((a=anchors_lookup(env->anchors, qinfo->qname, qinfo->qname_len,
789 qinfo->qclass))) {
790 if(a->numDS == 0 && a->numDNSKEY == 0) {
791 /* insecure trust point */
792 lock_basic_unlock(&a->lock);
793 return 0;
794 }
795 lock_basic_unlock(&a->lock);
796 return 1;
797 }
798 /* no trust anchor above it. */
799 return 0;
800 }
801
802 int
iter_indicates_dnssec(struct module_env * env,struct delegpt * dp,struct dns_msg * msg,uint16_t dclass)803 iter_indicates_dnssec(struct module_env* env, struct delegpt* dp,
804 struct dns_msg* msg, uint16_t dclass)
805 {
806 struct trust_anchor* a;
807 /* information not available, !env->anchors can be common */
808 if(!env || !env->anchors || !dp || !dp->name)
809 return 0;
810 /* a trust anchor exists with this name, RRSIGs expected */
811 if((a=anchor_find(env->anchors, dp->name, dp->namelabs, dp->namelen,
812 dclass))) {
813 if(a->numDS == 0 && a->numDNSKEY == 0) {
814 /* insecure trust point */
815 lock_basic_unlock(&a->lock);
816 return 0;
817 }
818 lock_basic_unlock(&a->lock);
819 return 1;
820 }
821 /* see if DS rrset was given, in AUTH section */
822 if(msg && msg->rep &&
823 reply_find_rrset_section_ns(msg->rep, dp->name, dp->namelen,
824 LDNS_RR_TYPE_DS, dclass))
825 return 1;
826 /* look in key cache */
827 if(env->key_cache) {
828 struct key_entry_key* kk = key_cache_obtain(env->key_cache,
829 dp->name, dp->namelen, dclass, env->scratch, *env->now);
830 if(kk) {
831 if(query_dname_compare(kk->name, dp->name) == 0) {
832 if(key_entry_isgood(kk) || key_entry_isbad(kk)) {
833 regional_free_all(env->scratch);
834 return 1;
835 } else if(key_entry_isnull(kk)) {
836 regional_free_all(env->scratch);
837 return 0;
838 }
839 }
840 regional_free_all(env->scratch);
841 }
842 }
843 return 0;
844 }
845
846 int
iter_msg_has_dnssec(struct dns_msg * msg)847 iter_msg_has_dnssec(struct dns_msg* msg)
848 {
849 size_t i;
850 if(!msg || !msg->rep)
851 return 0;
852 for(i=0; i<msg->rep->an_numrrsets + msg->rep->ns_numrrsets; i++) {
853 if(((struct packed_rrset_data*)msg->rep->rrsets[i]->
854 entry.data)->rrsig_count > 0)
855 return 1;
856 }
857 /* empty message has no DNSSEC info, with DNSSEC the reply is
858 * not empty (NSEC) */
859 return 0;
860 }
861
iter_msg_from_zone(struct dns_msg * msg,struct delegpt * dp,enum response_type type,uint16_t dclass)862 int iter_msg_from_zone(struct dns_msg* msg, struct delegpt* dp,
863 enum response_type type, uint16_t dclass)
864 {
865 if(!msg || !dp || !msg->rep || !dp->name)
866 return 0;
867 /* SOA RRset - always from reply zone */
868 if(reply_find_rrset_section_an(msg->rep, dp->name, dp->namelen,
869 LDNS_RR_TYPE_SOA, dclass) ||
870 reply_find_rrset_section_ns(msg->rep, dp->name, dp->namelen,
871 LDNS_RR_TYPE_SOA, dclass))
872 return 1;
873 if(type == RESPONSE_TYPE_REFERRAL) {
874 size_t i;
875 /* if it adds a single label, i.e. we expect .com,
876 * and referral to example.com. NS ... , then origin zone
877 * is .com. For a referral to sub.example.com. NS ... then
878 * we do not know, since example.com. may be in between. */
879 for(i=0; i<msg->rep->an_numrrsets+msg->rep->ns_numrrsets;
880 i++) {
881 struct ub_packed_rrset_key* s = msg->rep->rrsets[i];
882 if(ntohs(s->rk.type) == LDNS_RR_TYPE_NS &&
883 ntohs(s->rk.rrset_class) == dclass) {
884 int l = dname_count_labels(s->rk.dname);
885 if(l == dp->namelabs + 1 &&
886 dname_strict_subdomain(s->rk.dname,
887 l, dp->name, dp->namelabs))
888 return 1;
889 }
890 }
891 return 0;
892 }
893 log_assert(type==RESPONSE_TYPE_ANSWER || type==RESPONSE_TYPE_CNAME);
894 /* not a referral, and not lame delegation (upwards), so,
895 * any NS rrset must be from the zone itself */
896 if(reply_find_rrset_section_an(msg->rep, dp->name, dp->namelen,
897 LDNS_RR_TYPE_NS, dclass) ||
898 reply_find_rrset_section_ns(msg->rep, dp->name, dp->namelen,
899 LDNS_RR_TYPE_NS, dclass))
900 return 1;
901 /* a DNSKEY set is expected at the zone apex as well */
902 /* this is for 'minimal responses' for DNSKEYs */
903 if(reply_find_rrset_section_an(msg->rep, dp->name, dp->namelen,
904 LDNS_RR_TYPE_DNSKEY, dclass))
905 return 1;
906 return 0;
907 }
908
909 /**
910 * check equality of two rrsets
911 * @param k1: rrset
912 * @param k2: rrset
913 * @return true if equal
914 */
915 static int
rrset_equal(struct ub_packed_rrset_key * k1,struct ub_packed_rrset_key * k2)916 rrset_equal(struct ub_packed_rrset_key* k1, struct ub_packed_rrset_key* k2)
917 {
918 struct packed_rrset_data* d1 = (struct packed_rrset_data*)
919 k1->entry.data;
920 struct packed_rrset_data* d2 = (struct packed_rrset_data*)
921 k2->entry.data;
922 size_t i, t;
923 if(k1->rk.dname_len != k2->rk.dname_len ||
924 k1->rk.flags != k2->rk.flags ||
925 k1->rk.type != k2->rk.type ||
926 k1->rk.rrset_class != k2->rk.rrset_class ||
927 query_dname_compare(k1->rk.dname, k2->rk.dname) != 0)
928 return 0;
929 if( /* do not check ttl: d1->ttl != d2->ttl || */
930 d1->count != d2->count ||
931 d1->rrsig_count != d2->rrsig_count ||
932 d1->trust != d2->trust ||
933 d1->security != d2->security)
934 return 0;
935 t = d1->count + d1->rrsig_count;
936 for(i=0; i<t; i++) {
937 if(d1->rr_len[i] != d2->rr_len[i] ||
938 /* no ttl check: d1->rr_ttl[i] != d2->rr_ttl[i] ||*/
939 memcmp(d1->rr_data[i], d2->rr_data[i],
940 d1->rr_len[i]) != 0)
941 return 0;
942 }
943 return 1;
944 }
945
946 /** compare rrsets and sort canonically. Compares rrset name, type, class.
947 * return 0 if equal, +1 if x > y, and -1 if x < y.
948 */
949 static int
rrset_canonical_sort_cmp(const void * x,const void * y)950 rrset_canonical_sort_cmp(const void* x, const void* y)
951 {
952 struct ub_packed_rrset_key* rrx = *(struct ub_packed_rrset_key**)x;
953 struct ub_packed_rrset_key* rry = *(struct ub_packed_rrset_key**)y;
954 int r = dname_canonical_compare(rrx->rk.dname, rry->rk.dname);
955 if(r != 0)
956 return r;
957 if(rrx->rk.type != rry->rk.type) {
958 if(ntohs(rrx->rk.type) > ntohs(rry->rk.type))
959 return 1;
960 else return -1;
961 }
962 if(rrx->rk.rrset_class != rry->rk.rrset_class) {
963 if(ntohs(rrx->rk.rrset_class) > ntohs(rry->rk.rrset_class))
964 return 1;
965 else return -1;
966 }
967 return 0;
968 }
969
970 int
reply_equal(struct reply_info * p,struct reply_info * q,struct regional * region)971 reply_equal(struct reply_info* p, struct reply_info* q, struct regional* region)
972 {
973 size_t i;
974 struct ub_packed_rrset_key** sorted_p, **sorted_q;
975 if(p->flags != q->flags ||
976 p->qdcount != q->qdcount ||
977 /* do not check TTL, this may differ */
978 /*
979 p->ttl != q->ttl ||
980 p->prefetch_ttl != q->prefetch_ttl ||
981 */
982 p->security != q->security ||
983 p->an_numrrsets != q->an_numrrsets ||
984 p->ns_numrrsets != q->ns_numrrsets ||
985 p->ar_numrrsets != q->ar_numrrsets ||
986 p->rrset_count != q->rrset_count)
987 return 0;
988 /* sort the rrsets in the authority and additional sections before
989 * compare, the query and answer sections are ordered in the sequence
990 * they should have (eg. one after the other for aliases). */
991 sorted_p = (struct ub_packed_rrset_key**)regional_alloc_init(
992 region, p->rrsets, sizeof(*sorted_p)*p->rrset_count);
993 if(!sorted_p) return 0;
994 log_assert(p->an_numrrsets + p->ns_numrrsets + p->ar_numrrsets <=
995 p->rrset_count);
996 qsort(sorted_p + p->an_numrrsets, p->ns_numrrsets,
997 sizeof(*sorted_p), rrset_canonical_sort_cmp);
998 qsort(sorted_p + p->an_numrrsets + p->ns_numrrsets, p->ar_numrrsets,
999 sizeof(*sorted_p), rrset_canonical_sort_cmp);
1000
1001 sorted_q = (struct ub_packed_rrset_key**)regional_alloc_init(
1002 region, q->rrsets, sizeof(*sorted_q)*q->rrset_count);
1003 if(!sorted_q) {
1004 regional_free_all(region);
1005 return 0;
1006 }
1007 log_assert(q->an_numrrsets + q->ns_numrrsets + q->ar_numrrsets <=
1008 q->rrset_count);
1009 qsort(sorted_q + q->an_numrrsets, q->ns_numrrsets,
1010 sizeof(*sorted_q), rrset_canonical_sort_cmp);
1011 qsort(sorted_q + q->an_numrrsets + q->ns_numrrsets, q->ar_numrrsets,
1012 sizeof(*sorted_q), rrset_canonical_sort_cmp);
1013
1014 /* compare the rrsets */
1015 for(i=0; i<p->rrset_count; i++) {
1016 if(!rrset_equal(sorted_p[i], sorted_q[i])) {
1017 if(!rrset_canonical_equal(region, sorted_p[i],
1018 sorted_q[i])) {
1019 regional_free_all(region);
1020 return 0;
1021 }
1022 }
1023 }
1024 regional_free_all(region);
1025 return 1;
1026 }
1027
1028 void
caps_strip_reply(struct reply_info * rep)1029 caps_strip_reply(struct reply_info* rep)
1030 {
1031 size_t i;
1032 if(!rep) return;
1033 /* see if message is a referral, in which case the additional and
1034 * NS record cannot be removed */
1035 /* referrals have the AA flag unset (strict check, not elsewhere in
1036 * unbound, but for 0x20 this is very convenient). */
1037 if(!(rep->flags&BIT_AA))
1038 return;
1039 /* remove the additional section from the reply */
1040 if(rep->ar_numrrsets != 0) {
1041 verbose(VERB_ALGO, "caps fallback: removing additional section");
1042 rep->rrset_count -= rep->ar_numrrsets;
1043 rep->ar_numrrsets = 0;
1044 }
1045 /* is there an NS set in the authority section to remove? */
1046 /* the failure case (Cisco firewalls) only has one rrset in authsec */
1047 for(i=rep->an_numrrsets; i<rep->an_numrrsets+rep->ns_numrrsets; i++) {
1048 struct ub_packed_rrset_key* s = rep->rrsets[i];
1049 if(ntohs(s->rk.type) == LDNS_RR_TYPE_NS) {
1050 /* remove NS rrset and break from loop (loop limits
1051 * have changed) */
1052 /* move last rrset into this position (there is no
1053 * additional section any more) */
1054 verbose(VERB_ALGO, "caps fallback: removing NS rrset");
1055 if(i < rep->rrset_count-1)
1056 rep->rrsets[i]=rep->rrsets[rep->rrset_count-1];
1057 rep->rrset_count --;
1058 rep->ns_numrrsets --;
1059 break;
1060 }
1061 }
1062 }
1063
caps_failed_rcode(struct reply_info * rep)1064 int caps_failed_rcode(struct reply_info* rep)
1065 {
1066 return !(FLAGS_GET_RCODE(rep->flags) == LDNS_RCODE_NOERROR ||
1067 FLAGS_GET_RCODE(rep->flags) == LDNS_RCODE_NXDOMAIN);
1068 }
1069
1070 void
iter_store_parentside_rrset(struct module_env * env,struct ub_packed_rrset_key * rrset)1071 iter_store_parentside_rrset(struct module_env* env,
1072 struct ub_packed_rrset_key* rrset)
1073 {
1074 struct rrset_ref ref;
1075 rrset = packed_rrset_copy_alloc(rrset, env->alloc, *env->now);
1076 if(!rrset) {
1077 log_err("malloc failure in store_parentside_rrset");
1078 return;
1079 }
1080 rrset->rk.flags |= PACKED_RRSET_PARENT_SIDE;
1081 rrset->entry.hash = rrset_key_hash(&rrset->rk);
1082 ref.key = rrset;
1083 ref.id = rrset->id;
1084 /* ignore ret: if it was in the cache, ref updated */
1085 (void)rrset_cache_update(env->rrset_cache, &ref, env->alloc, *env->now);
1086 }
1087
1088 /** fetch NS record from reply, if any */
1089 static struct ub_packed_rrset_key*
reply_get_NS_rrset(struct reply_info * rep)1090 reply_get_NS_rrset(struct reply_info* rep)
1091 {
1092 size_t i;
1093 for(i=0; i<rep->rrset_count; i++) {
1094 if(rep->rrsets[i]->rk.type == htons(LDNS_RR_TYPE_NS)) {
1095 return rep->rrsets[i];
1096 }
1097 }
1098 return NULL;
1099 }
1100
1101 void
iter_store_parentside_NS(struct module_env * env,struct reply_info * rep)1102 iter_store_parentside_NS(struct module_env* env, struct reply_info* rep)
1103 {
1104 struct ub_packed_rrset_key* rrset = reply_get_NS_rrset(rep);
1105 if(rrset) {
1106 log_rrset_key(VERB_ALGO, "store parent-side NS", rrset);
1107 iter_store_parentside_rrset(env, rrset);
1108 }
1109 }
1110
iter_store_parentside_neg(struct module_env * env,struct query_info * qinfo,struct reply_info * rep)1111 void iter_store_parentside_neg(struct module_env* env,
1112 struct query_info* qinfo, struct reply_info* rep)
1113 {
1114 /* TTL: NS from referral in iq->deleg_msg,
1115 * or first RR from iq->response,
1116 * or servfail5secs if !iq->response */
1117 time_t ttl = NORR_TTL;
1118 struct ub_packed_rrset_key* neg;
1119 struct packed_rrset_data* newd;
1120 if(rep) {
1121 struct ub_packed_rrset_key* rrset = reply_get_NS_rrset(rep);
1122 if(!rrset && rep->rrset_count != 0) rrset = rep->rrsets[0];
1123 if(rrset) ttl = ub_packed_rrset_ttl(rrset);
1124 }
1125 /* create empty rrset to store */
1126 neg = (struct ub_packed_rrset_key*)regional_alloc(env->scratch,
1127 sizeof(struct ub_packed_rrset_key));
1128 if(!neg) {
1129 log_err("out of memory in store_parentside_neg");
1130 return;
1131 }
1132 memset(&neg->entry, 0, sizeof(neg->entry));
1133 neg->entry.key = neg;
1134 neg->rk.type = htons(qinfo->qtype);
1135 neg->rk.rrset_class = htons(qinfo->qclass);
1136 neg->rk.flags = 0;
1137 neg->rk.dname = regional_alloc_init(env->scratch, qinfo->qname,
1138 qinfo->qname_len);
1139 if(!neg->rk.dname) {
1140 log_err("out of memory in store_parentside_neg");
1141 return;
1142 }
1143 neg->rk.dname_len = qinfo->qname_len;
1144 neg->entry.hash = rrset_key_hash(&neg->rk);
1145 newd = (struct packed_rrset_data*)regional_alloc_zero(env->scratch,
1146 sizeof(struct packed_rrset_data) + sizeof(size_t) +
1147 sizeof(uint8_t*) + sizeof(time_t) + sizeof(uint16_t));
1148 if(!newd) {
1149 log_err("out of memory in store_parentside_neg");
1150 return;
1151 }
1152 neg->entry.data = newd;
1153 newd->ttl = ttl;
1154 /* entry must have one RR, otherwise not valid in cache.
1155 * put in one RR with empty rdata: those are ignored as nameserver */
1156 newd->count = 1;
1157 newd->rrsig_count = 0;
1158 newd->trust = rrset_trust_ans_noAA;
1159 newd->rr_len = (size_t*)((uint8_t*)newd +
1160 sizeof(struct packed_rrset_data));
1161 newd->rr_len[0] = 0 /* zero len rdata */ + sizeof(uint16_t);
1162 packed_rrset_ptr_fixup(newd);
1163 newd->rr_ttl[0] = newd->ttl;
1164 sldns_write_uint16(newd->rr_data[0], 0 /* zero len rdata */);
1165 /* store it */
1166 log_rrset_key(VERB_ALGO, "store parent-side negative", neg);
1167 iter_store_parentside_rrset(env, neg);
1168 }
1169
1170 int
iter_lookup_parent_NS_from_cache(struct module_env * env,struct delegpt * dp,struct regional * region,struct query_info * qinfo)1171 iter_lookup_parent_NS_from_cache(struct module_env* env, struct delegpt* dp,
1172 struct regional* region, struct query_info* qinfo)
1173 {
1174 struct ub_packed_rrset_key* akey;
1175 akey = rrset_cache_lookup(env->rrset_cache, dp->name,
1176 dp->namelen, LDNS_RR_TYPE_NS, qinfo->qclass,
1177 PACKED_RRSET_PARENT_SIDE, *env->now, 0);
1178 if(akey) {
1179 log_rrset_key(VERB_ALGO, "found parent-side NS in cache", akey);
1180 dp->has_parent_side_NS = 1;
1181 /* and mark the new names as lame */
1182 if(!delegpt_rrset_add_ns(dp, region, akey, 1)) {
1183 lock_rw_unlock(&akey->entry.lock);
1184 return 0;
1185 }
1186 lock_rw_unlock(&akey->entry.lock);
1187 }
1188 return 1;
1189 }
1190
iter_lookup_parent_glue_from_cache(struct module_env * env,struct delegpt * dp,struct regional * region,struct query_info * qinfo)1191 int iter_lookup_parent_glue_from_cache(struct module_env* env,
1192 struct delegpt* dp, struct regional* region, struct query_info* qinfo)
1193 {
1194 struct ub_packed_rrset_key* akey;
1195 struct delegpt_ns* ns;
1196 size_t num = delegpt_count_targets(dp);
1197 for(ns = dp->nslist; ns; ns = ns->next) {
1198 /* get cached parentside A */
1199 akey = rrset_cache_lookup(env->rrset_cache, ns->name,
1200 ns->namelen, LDNS_RR_TYPE_A, qinfo->qclass,
1201 PACKED_RRSET_PARENT_SIDE, *env->now, 0);
1202 if(akey) {
1203 log_rrset_key(VERB_ALGO, "found parent-side", akey);
1204 ns->done_pside4 = 1;
1205 /* a negative-cache-element has no addresses it adds */
1206 if(!delegpt_add_rrset_A(dp, region, akey, 1, NULL))
1207 log_err("malloc failure in lookup_parent_glue");
1208 lock_rw_unlock(&akey->entry.lock);
1209 }
1210 /* get cached parentside AAAA */
1211 akey = rrset_cache_lookup(env->rrset_cache, ns->name,
1212 ns->namelen, LDNS_RR_TYPE_AAAA, qinfo->qclass,
1213 PACKED_RRSET_PARENT_SIDE, *env->now, 0);
1214 if(akey) {
1215 log_rrset_key(VERB_ALGO, "found parent-side", akey);
1216 ns->done_pside6 = 1;
1217 /* a negative-cache-element has no addresses it adds */
1218 if(!delegpt_add_rrset_AAAA(dp, region, akey, 1, NULL))
1219 log_err("malloc failure in lookup_parent_glue");
1220 lock_rw_unlock(&akey->entry.lock);
1221 }
1222 }
1223 /* see if new (but lame) addresses have become available */
1224 return delegpt_count_targets(dp) != num;
1225 }
1226
1227 int
iter_get_next_root(struct iter_hints * hints,struct iter_forwards * fwd,uint16_t * c)1228 iter_get_next_root(struct iter_hints* hints, struct iter_forwards* fwd,
1229 uint16_t* c)
1230 {
1231 uint16_t c1 = *c, c2 = *c;
1232 int r1 = hints_next_root(hints, &c1);
1233 int r2 = forwards_next_root(fwd, &c2);
1234 if(!r1 && !r2) /* got none, end of list */
1235 return 0;
1236 else if(!r1) /* got one, return that */
1237 *c = c2;
1238 else if(!r2)
1239 *c = c1;
1240 else if(c1 < c2) /* got both take smallest */
1241 *c = c1;
1242 else *c = c2;
1243 return 1;
1244 }
1245
1246 void
iter_scrub_ds(struct dns_msg * msg,struct ub_packed_rrset_key * ns,uint8_t * z)1247 iter_scrub_ds(struct dns_msg* msg, struct ub_packed_rrset_key* ns, uint8_t* z)
1248 {
1249 /* Only the DS record for the delegation itself is expected.
1250 * We allow DS for everything between the bailiwick and the
1251 * zonecut, thus DS records must be at or above the zonecut.
1252 * And the DS records must be below the server authority zone.
1253 * The answer section is already scrubbed. */
1254 size_t i = msg->rep->an_numrrsets;
1255 while(i < (msg->rep->an_numrrsets + msg->rep->ns_numrrsets)) {
1256 struct ub_packed_rrset_key* s = msg->rep->rrsets[i];
1257 if(ntohs(s->rk.type) == LDNS_RR_TYPE_DS &&
1258 (!ns || !dname_subdomain_c(ns->rk.dname, s->rk.dname)
1259 || query_dname_compare(z, s->rk.dname) == 0)) {
1260 log_nametypeclass(VERB_ALGO, "removing irrelevant DS",
1261 s->rk.dname, ntohs(s->rk.type),
1262 ntohs(s->rk.rrset_class));
1263 memmove(msg->rep->rrsets+i, msg->rep->rrsets+i+1,
1264 sizeof(struct ub_packed_rrset_key*) *
1265 (msg->rep->rrset_count-i-1));
1266 msg->rep->ns_numrrsets--;
1267 msg->rep->rrset_count--;
1268 /* stay at same i, but new record */
1269 continue;
1270 }
1271 i++;
1272 }
1273 }
1274
1275 void
iter_scrub_nxdomain(struct dns_msg * msg)1276 iter_scrub_nxdomain(struct dns_msg* msg)
1277 {
1278 if(msg->rep->an_numrrsets == 0)
1279 return;
1280
1281 memmove(msg->rep->rrsets, msg->rep->rrsets+msg->rep->an_numrrsets,
1282 sizeof(struct ub_packed_rrset_key*) *
1283 (msg->rep->rrset_count-msg->rep->an_numrrsets));
1284 msg->rep->rrset_count -= msg->rep->an_numrrsets;
1285 msg->rep->an_numrrsets = 0;
1286 }
1287
iter_dec_attempts(struct delegpt * dp,int d,int outbound_msg_retry)1288 void iter_dec_attempts(struct delegpt* dp, int d, int outbound_msg_retry)
1289 {
1290 struct delegpt_addr* a;
1291 for(a=dp->target_list; a; a = a->next_target) {
1292 if(a->attempts >= outbound_msg_retry) {
1293 /* add back to result list */
1294 a->next_result = dp->result_list;
1295 dp->result_list = a;
1296 }
1297 if(a->attempts > d)
1298 a->attempts -= d;
1299 else a->attempts = 0;
1300 }
1301 }
1302
iter_merge_retry_counts(struct delegpt * dp,struct delegpt * old,int outbound_msg_retry)1303 void iter_merge_retry_counts(struct delegpt* dp, struct delegpt* old,
1304 int outbound_msg_retry)
1305 {
1306 struct delegpt_addr* a, *o, *prev;
1307 for(a=dp->target_list; a; a = a->next_target) {
1308 o = delegpt_find_addr(old, &a->addr, a->addrlen);
1309 if(o) {
1310 log_addr(VERB_ALGO, "copy attempt count previous dp",
1311 &a->addr, a->addrlen);
1312 a->attempts = o->attempts;
1313 }
1314 }
1315 prev = NULL;
1316 a = dp->usable_list;
1317 while(a) {
1318 if(a->attempts >= outbound_msg_retry) {
1319 log_addr(VERB_ALGO, "remove from usable list dp",
1320 &a->addr, a->addrlen);
1321 /* remove from result list */
1322 if(prev)
1323 prev->next_usable = a->next_usable;
1324 else dp->usable_list = a->next_usable;
1325 /* prev stays the same */
1326 a = a->next_usable;
1327 continue;
1328 }
1329 prev = a;
1330 a = a->next_usable;
1331 }
1332 }
1333
1334 int
iter_ds_toolow(struct dns_msg * msg,struct delegpt * dp)1335 iter_ds_toolow(struct dns_msg* msg, struct delegpt* dp)
1336 {
1337 /* if for query example.com, there is example.com SOA or a subdomain
1338 * of example.com, then we are too low and need to fetch NS. */
1339 size_t i;
1340 /* if we have a DNAME or CNAME we are probably wrong */
1341 /* if we have a qtype DS in the answer section, its fine */
1342 for(i=0; i < msg->rep->an_numrrsets; i++) {
1343 struct ub_packed_rrset_key* s = msg->rep->rrsets[i];
1344 if(ntohs(s->rk.type) == LDNS_RR_TYPE_DNAME ||
1345 ntohs(s->rk.type) == LDNS_RR_TYPE_CNAME) {
1346 /* not the right answer, maybe too low, check the
1347 * RRSIG signer name (if there is any) for a hint
1348 * that it is from the dp zone anyway */
1349 uint8_t* sname;
1350 size_t slen;
1351 val_find_rrset_signer(s, &sname, &slen);
1352 if(sname && query_dname_compare(dp->name, sname)==0)
1353 return 0; /* it is fine, from the right dp */
1354 return 1;
1355 }
1356 if(ntohs(s->rk.type) == LDNS_RR_TYPE_DS)
1357 return 0; /* fine, we have a DS record */
1358 }
1359 for(i=msg->rep->an_numrrsets;
1360 i < msg->rep->an_numrrsets + msg->rep->ns_numrrsets; i++) {
1361 struct ub_packed_rrset_key* s = msg->rep->rrsets[i];
1362 if(ntohs(s->rk.type) == LDNS_RR_TYPE_SOA) {
1363 if(dname_subdomain_c(s->rk.dname, msg->qinfo.qname))
1364 return 1; /* point is too low */
1365 if(query_dname_compare(s->rk.dname, dp->name)==0)
1366 return 0; /* right dp */
1367 }
1368 if(ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC ||
1369 ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC3) {
1370 uint8_t* sname;
1371 size_t slen;
1372 val_find_rrset_signer(s, &sname, &slen);
1373 if(sname && query_dname_compare(dp->name, sname)==0)
1374 return 0; /* it is fine, from the right dp */
1375 return 1;
1376 }
1377 }
1378 /* we do not know */
1379 return 1;
1380 }
1381
iter_dp_cangodown(struct query_info * qinfo,struct delegpt * dp)1382 int iter_dp_cangodown(struct query_info* qinfo, struct delegpt* dp)
1383 {
1384 /* no delegation point, do not see how we can go down,
1385 * robust check, it should really exist */
1386 if(!dp) return 0;
1387
1388 /* see if dp equals the qname, then we cannot go down further */
1389 if(query_dname_compare(qinfo->qname, dp->name) == 0)
1390 return 0;
1391 /* if dp is one label above the name we also cannot go down further */
1392 if(dname_count_labels(qinfo->qname) == dp->namelabs+1)
1393 return 0;
1394 return 1;
1395 }
1396
1397 int
iter_stub_fwd_no_cache(struct module_qstate * qstate,struct query_info * qinf,uint8_t ** retdpname,size_t * retdpnamelen)1398 iter_stub_fwd_no_cache(struct module_qstate *qstate, struct query_info *qinf,
1399 uint8_t** retdpname, size_t* retdpnamelen)
1400 {
1401 struct iter_hints_stub *stub;
1402 struct delegpt *dp;
1403
1404 /* Check for stub. */
1405 stub = hints_lookup_stub(qstate->env->hints, qinf->qname,
1406 qinf->qclass, NULL);
1407 dp = forwards_lookup(qstate->env->fwds, qinf->qname, qinf->qclass);
1408
1409 /* see if forward or stub is more pertinent */
1410 if(stub && stub->dp && dp) {
1411 if(dname_strict_subdomain(dp->name, dp->namelabs,
1412 stub->dp->name, stub->dp->namelabs)) {
1413 stub = NULL; /* ignore stub, forward is lower */
1414 } else {
1415 dp = NULL; /* ignore forward, stub is lower */
1416 }
1417 }
1418
1419 /* check stub */
1420 if (stub != NULL && stub->dp != NULL) {
1421 if(stub->dp->no_cache) {
1422 char qname[255+1];
1423 char dpname[255+1];
1424 dname_str(qinf->qname, qname);
1425 dname_str(stub->dp->name, dpname);
1426 verbose(VERB_ALGO, "stub for %s %s has no_cache", qname, dpname);
1427 }
1428 if(retdpname) {
1429 *retdpname = stub->dp->name;
1430 *retdpnamelen = stub->dp->namelen;
1431 }
1432 return (stub->dp->no_cache);
1433 }
1434
1435 /* Check for forward. */
1436 if (dp) {
1437 if(dp->no_cache) {
1438 char qname[255+1];
1439 char dpname[255+1];
1440 dname_str(qinf->qname, qname);
1441 dname_str(dp->name, dpname);
1442 verbose(VERB_ALGO, "forward for %s %s has no_cache", qname, dpname);
1443 }
1444 if(retdpname) {
1445 *retdpname = dp->name;
1446 *retdpnamelen = dp->namelen;
1447 }
1448 return (dp->no_cache);
1449 }
1450 if(retdpname) {
1451 *retdpname = NULL;
1452 *retdpnamelen = 0;
1453 }
1454 return 0;
1455 }
1456
iterator_set_ip46_support(struct module_stack * mods,struct module_env * env,struct outside_network * outnet)1457 void iterator_set_ip46_support(struct module_stack* mods,
1458 struct module_env* env, struct outside_network* outnet)
1459 {
1460 int m = modstack_find(mods, "iterator");
1461 struct iter_env* ie = NULL;
1462 if(m == -1)
1463 return;
1464 ie = (struct iter_env*)env->modinfo[m];
1465 if(outnet->pending == NULL)
1466 return; /* we are in testbound, no rbtree for UDP */
1467 if(outnet->num_ip4 == 0)
1468 ie->supports_ipv4 = 0;
1469 if(outnet->num_ip6 == 0)
1470 ie->supports_ipv6 = 0;
1471 }
1472