contrib/unbound/services/mesh.c

   1 /*
   2  * services/mesh.c - deal with mesh of query states and handle events for that.
   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 in dealing with a mesh of
  40  * query states. This mesh is supposed to be thread-specific.
  41  * It consists of query states (per qname, qtype, qclass) and connections
  42  * between query states and the super and subquery states, and replies to
  43  * send back to clients.
  44  */
  45 #include "config.h"
  46 #include "services/mesh.h"
  47 #include "services/outbound_list.h"
  48 #include "services/cache/dns.h"
  49 #include "services/cache/rrset.h"
  50 #include "util/log.h"
  51 #include "util/net_help.h"
  52 #include "util/module.h"
  53 #include "util/regional.h"
  54 #include "util/data/msgencode.h"
  55 #include "util/timehist.h"
  56 #include "util/fptr_wlist.h"
  57 #include "util/alloc.h"
  58 #include "util/config_file.h"
  59 #include "util/edns.h"
  60 #include "sldns/sbuffer.h"
  61 #include "sldns/wire2str.h"
  62 #include "services/localzone.h"
  63 #include "util/data/dname.h"
  64 #include "respip/respip.h"
  65 #include "services/listen_dnsport.h"
  66
  67 /** subtract timers and the values do not overflow or become negative */
  68 static void
  69 timeval_subtract(struct timeval* d, const struct timeval* end, const struct timeval* start)
  70 {
  71 #ifndef S_SPLINT_S
  72         time_t end_usec = end->tv_usec;
  73         d->tv_sec = end->tv_sec - start->tv_sec;
  74         if(end_usec < start->tv_usec) {
  75                 end_usec += 1000000;
  76                 d->tv_sec--;
  77         }
  78         d->tv_usec = end_usec - start->tv_usec;
  79 #endif
  80 }
  81
  82 /** add timers and the values do not overflow or become negative */
  83 static void
  84 timeval_add(struct timeval* d, const struct timeval* add)
  85 {
  86 #ifndef S_SPLINT_S
  87         d->tv_sec += add->tv_sec;
  88         d->tv_usec += add->tv_usec;
  89         if(d->tv_usec >= 1000000 ) {
  90                 d->tv_usec -= 1000000;
  91                 d->tv_sec++;
  92         }
  93 #endif
  94 }
  95
  96 /** divide sum of timers to get average */
  97 static void
  98 timeval_divide(struct timeval* avg, const struct timeval* sum, size_t d)
  99 {
 100 #ifndef S_SPLINT_S
 101         size_t leftover;
 102         if(d <= 0) {
 103                 avg->tv_sec = 0;
 104                 avg->tv_usec = 0;
 105                 return;
 106         }
 107         avg->tv_sec = sum->tv_sec / d;
 108         avg->tv_usec = sum->tv_usec / d;
 109         /* handle fraction from seconds divide */
 110         leftover = sum->tv_sec - avg->tv_sec*d;
 111         if(leftover <= 0)
 112                 leftover = 0;
 113         avg->tv_usec += (((long long)leftover)*((long long)1000000))/d;
 114         if(avg->tv_sec < 0)
 115                 avg->tv_sec = 0;
 116         if(avg->tv_usec < 0)
 117                 avg->tv_usec = 0;
 118 #endif
 119 }
 120
 121 /** histogram compare of time values */
 122 static int
 123 timeval_smaller(const struct timeval* x, const struct timeval* y)
 124 {
 125 #ifndef S_SPLINT_S
 126         if(x->tv_sec < y->tv_sec)
 127                 return 1;
 128         else if(x->tv_sec == y->tv_sec) {
 129                 if(x->tv_usec <= y->tv_usec)
 130                         return 1;
 131                 else    return 0;
 132         }
 133         else    return 0;
 134 #endif
 135 }
 136
 137 /**
 138  * Compare two response-ip client info entries for the purpose of mesh state
 139  * compare.  It returns 0 if ci_a and ci_b are considered equal; otherwise
 140  * 1 or -1 (they mean 'ci_a is larger/smaller than ci_b', respectively, but
 141  * in practice it should be only used to mean they are different).
 142  * We cannot share the mesh state for two queries if different response-ip
 143  * actions can apply in the end, even if those queries are otherwise identical.
 144  * For this purpose we compare tag lists and tag action lists; they should be
 145  * identical to share the same state.
 146  * For tag data, we don't look into the data content, as it can be
 147  * expensive; unless tag data are not defined for both or they point to the
 148  * exact same data in memory (i.e., they come from the same ACL entry), we
 149  * consider these data different.
 150  * Likewise, if the client info is associated with views, we don't look into
 151  * the views.  They are considered different unless they are exactly the same
 152  * even if the views only differ in the names.
 153  */
 154 static int
 155 client_info_compare(const struct respip_client_info* ci_a,
 156         const struct respip_client_info* ci_b)
 157 {
 158         int cmp;
 159
 160         if(!ci_a && !ci_b)
 161                 return 0;
 162         if(ci_a && !ci_b)
 163                 return -1;
 164         if(!ci_a && ci_b)
 165                 return 1;
 166         if(ci_a->taglen != ci_b->taglen)
 167                 return (ci_a->taglen < ci_b->taglen) ? -1 : 1;
 168         if(ci_a->taglist && !ci_b->taglist)
 169                 return -1;
 170         if(!ci_a->taglist && ci_b->taglist)
 171                 return 1;
 172         if(ci_a->taglist && ci_b->taglist) {
 173                 cmp = memcmp(ci_a->taglist, ci_b->taglist, ci_a->taglen);
 174                 if(cmp != 0)
 175                         return cmp;
 176         }
 177         if(ci_a->tag_actions_size != ci_b->tag_actions_size)
 178                 return (ci_a->tag_actions_size < ci_b->tag_actions_size) ?
 179                         -1 : 1;
 180         if(ci_a->tag_actions && !ci_b->tag_actions)
 181                 return -1;
 182         if(!ci_a->tag_actions && ci_b->tag_actions)
 183                 return 1;
 184         if(ci_a->tag_actions && ci_b->tag_actions) {
 185                 cmp = memcmp(ci_a->tag_actions, ci_b->tag_actions,
 186                         ci_a->tag_actions_size);
 187                 if(cmp != 0)
 188                         return cmp;
 189         }
 190         if(ci_a->tag_datas != ci_b->tag_datas)
 191                 return ci_a->tag_datas < ci_b->tag_datas ? -1 : 1;
 192         if(ci_a->view != ci_b->view)
 193                 return ci_a->view < ci_b->view ? -1 : 1;
 194         /* For the unbound daemon these should be non-NULL and identical,
 195          * but we check that just in case. */
 196         if(ci_a->respip_set != ci_b->respip_set)
 197                 return ci_a->respip_set < ci_b->respip_set ? -1 : 1;
 198         return 0;
 199 }
 200
 201 int
 202 mesh_state_compare(const void* ap, const void* bp)
 203 {
 204         struct mesh_state* a = (struct mesh_state*)ap;
 205         struct mesh_state* b = (struct mesh_state*)bp;
 206         int cmp;
 207
 208         if(a->unique < b->unique)
 209                 return -1;
 210         if(a->unique > b->unique)
 211                 return 1;
 212
 213         if(a->s.is_priming && !b->s.is_priming)
 214                 return -1;
 215         if(!a->s.is_priming && b->s.is_priming)
 216                 return 1;
 217
 218         if(a->s.is_valrec && !b->s.is_valrec)
 219                 return -1;
 220         if(!a->s.is_valrec && b->s.is_valrec)
 221                 return 1;
 222
 223         if((a->s.query_flags&BIT_RD) && !(b->s.query_flags&BIT_RD))
 224                 return -1;
 225         if(!(a->s.query_flags&BIT_RD) && (b->s.query_flags&BIT_RD))
 226                 return 1;
 227
 228         if((a->s.query_flags&BIT_CD) && !(b->s.query_flags&BIT_CD))
 229                 return -1;
 230         if(!(a->s.query_flags&BIT_CD) && (b->s.query_flags&BIT_CD))
 231                 return 1;
 232
 233         cmp = query_info_compare(&a->s.qinfo, &b->s.qinfo);
 234         if(cmp != 0)
 235                 return cmp;
 236         return client_info_compare(a->s.client_info, b->s.client_info);
 237 }
 238
 239 int
 240 mesh_state_ref_compare(const void* ap, const void* bp)
 241 {
 242         struct mesh_state_ref* a = (struct mesh_state_ref*)ap;
 243         struct mesh_state_ref* b = (struct mesh_state_ref*)bp;
 244         return mesh_state_compare(a->s, b->s);
 245 }
 246
 247 struct mesh_area*
 248 mesh_create(struct module_stack* stack, struct module_env* env)
 249 {
 250         struct mesh_area* mesh = calloc(1, sizeof(struct mesh_area));
 251         if(!mesh) {
 252                 log_err("mesh area alloc: out of memory");
 253                 return NULL;
 254         }
 255         mesh->histogram = timehist_setup();
 256         mesh->qbuf_bak = sldns_buffer_new(env->cfg->msg_buffer_size);
 257         if(!mesh->histogram || !mesh->qbuf_bak) {
 258                 free(mesh);
 259                 log_err("mesh area alloc: out of memory");
 260                 return NULL;
 261         }
 262         mesh->mods = *stack;
 263         mesh->env = env;
 264         rbtree_init(&mesh->run, &mesh_state_compare);
 265         rbtree_init(&mesh->all, &mesh_state_compare);
 266         mesh->num_reply_addrs = 0;
 267         mesh->num_reply_states = 0;
 268         mesh->num_detached_states = 0;
 269         mesh->num_forever_states = 0;
 270         mesh->stats_jostled = 0;
 271         mesh->stats_dropped = 0;
 272         mesh->ans_expired = 0;
 273         mesh->max_reply_states = env->cfg->num_queries_per_thread;
 274         mesh->max_forever_states = (mesh->max_reply_states+1)/2;
 275 #ifndef S_SPLINT_S
 276         mesh->jostle_max.tv_sec = (time_t)(env->cfg->jostle_time / 1000);
 277         mesh->jostle_max.tv_usec = (time_t)((env->cfg->jostle_time % 1000)
 278                 *1000);
 279 #endif
 280         return mesh;
 281 }
 282
 283 /** help mesh delete delete mesh states */
 284 static void
 285 mesh_delete_helper(rbnode_type* n)
 286 {
 287         struct mesh_state* mstate = (struct mesh_state*)n->key;
 288         /* perform a full delete, not only 'cleanup' routine,
 289          * because other callbacks expect a clean state in the mesh.
 290          * For 're-entrant' calls */
 291         mesh_state_delete(&mstate->s);
 292         /* but because these delete the items from the tree, postorder
 293          * traversal and rbtree rebalancing do not work together */
 294 }
 295
 296 void
 297 mesh_delete(struct mesh_area* mesh)
 298 {
 299         if(!mesh)
 300                 return;
 301         /* free all query states */
 302         while(mesh->all.count)
 303                 mesh_delete_helper(mesh->all.root);
 304         timehist_delete(mesh->histogram);
 305         sldns_buffer_free(mesh->qbuf_bak);
 306         free(mesh);
 307 }
 308
 309 void
 310 mesh_delete_all(struct mesh_area* mesh)
 311 {
 312         /* free all query states */
 313         while(mesh->all.count)
 314                 mesh_delete_helper(mesh->all.root);
 315         mesh->stats_dropped += mesh->num_reply_addrs;
 316         /* clear mesh area references */
 317         rbtree_init(&mesh->run, &mesh_state_compare);
 318         rbtree_init(&mesh->all, &mesh_state_compare);
 319         mesh->num_reply_addrs = 0;
 320         mesh->num_reply_states = 0;
 321         mesh->num_detached_states = 0;
 322         mesh->num_forever_states = 0;
 323         mesh->forever_first = NULL;
 324         mesh->forever_last = NULL;
 325         mesh->jostle_first = NULL;
 326         mesh->jostle_last = NULL;
 327 }
 328
 329 int mesh_make_new_space(struct mesh_area* mesh, sldns_buffer* qbuf)
 330 {
 331         struct mesh_state* m = mesh->jostle_first;
 332         /* free space is available */
 333         if(mesh->num_reply_states < mesh->max_reply_states)
 334                 return 1;
 335         /* try to kick out a jostle-list item */
 336         if(m && m->reply_list && m->list_select == mesh_jostle_list) {
 337                 /* how old is it? */
 338                 struct timeval age;
 339                 timeval_subtract(&age, mesh->env->now_tv,
 340                         &m->reply_list->start_time);
 341                 if(timeval_smaller(&mesh->jostle_max, &age)) {
 342                         /* its a goner */
 343                         log_nametypeclass(VERB_ALGO, "query jostled out to "
 344                                 "make space for a new one",
 345                                 m->s.qinfo.qname, m->s.qinfo.qtype,
 346                                 m->s.qinfo.qclass);
 347                         /* backup the query */
 348                         if(qbuf) sldns_buffer_copy(mesh->qbuf_bak, qbuf);
 349                         /* notify supers */
 350                         if(m->super_set.count > 0) {
 351                                 verbose(VERB_ALGO, "notify supers of failure");
 352                                 m->s.return_msg = NULL;
 353                                 m->s.return_rcode = LDNS_RCODE_SERVFAIL;
 354                                 mesh_walk_supers(mesh, m);
 355                         }
 356                         mesh->stats_jostled ++;
 357                         mesh_state_delete(&m->s);
 358                         /* restore the query - note that the qinfo ptr to
 359                          * the querybuffer is then correct again. */
 360                         if(qbuf) sldns_buffer_copy(qbuf, mesh->qbuf_bak);
 361                         return 1;
 362                 }
 363         }
 364         /* no space for new item */
 365         return 0;
 366 }
 367
 368 struct dns_msg*
 369 mesh_serve_expired_lookup(struct module_qstate* qstate,
 370         struct query_info* lookup_qinfo)
 371 {
 372         hashvalue_type h;
 373         struct lruhash_entry* e;
 374         struct dns_msg* msg;
 375         struct reply_info* data;
 376         struct msgreply_entry* key;
 377         time_t timenow = *qstate->env->now;
 378         int must_validate = (!(qstate->query_flags&BIT_CD)
 379                 || qstate->env->cfg->ignore_cd) && qstate->env->need_to_validate;
 380         /* Lookup cache */
 381         h = query_info_hash(lookup_qinfo, qstate->query_flags);
 382         e = slabhash_lookup(qstate->env->msg_cache, h, lookup_qinfo, 0);
 383         if(!e) return NULL;
 384
 385         key = (struct msgreply_entry*)e->key;
 386         data = (struct reply_info*)e->data;
 387         msg = tomsg(qstate->env, &key->key, data, qstate->region, timenow,
 388                 qstate->env->cfg->serve_expired, qstate->env->scratch);
 389         if(!msg)
 390                 goto bail_out;
 391
 392         /* Check CNAME chain (if any)
 393          * This is part of tomsg above; no need to check now. */
 394
 395         /* Check security status of the cached answer.
 396          * tomsg above has a subset of these checks, so we are leaving
 397          * these as is.
 398          * In case of bogus or revalidation we don't care to reply here. */
 399         if(must_validate && (msg->rep->security == sec_status_bogus ||
 400                 msg->rep->security == sec_status_secure_sentinel_fail)) {
 401                 verbose(VERB_ALGO, "Serve expired: bogus answer found in cache");
 402                 goto bail_out;
 403         } else if(msg->rep->security == sec_status_unchecked && must_validate) {
 404                 verbose(VERB_ALGO, "Serve expired: unchecked entry needs "
 405                         "validation");
 406                 goto bail_out; /* need to validate cache entry first */
 407         } else if(msg->rep->security == sec_status_secure &&
 408                 !reply_all_rrsets_secure(msg->rep) && must_validate) {
 409                         verbose(VERB_ALGO, "Serve expired: secure entry"
 410                                 " changed status");
 411                         goto bail_out; /* rrset changed, re-verify */
 412         }
 413
 414         lock_rw_unlock(&e->lock);
 415         return msg;
 416
 417 bail_out:
 418         lock_rw_unlock(&e->lock);
 419         return NULL;
 420 }
 421
 422
 423 /** Init the serve expired data structure */
 424 static int
 425 mesh_serve_expired_init(struct mesh_state* mstate, int timeout)
 426 {
 427         struct timeval t;
 428
 429         /* Create serve_expired_data if not there yet */
 430         if(!mstate->s.serve_expired_data) {
 431                 mstate->s.serve_expired_data = (struct serve_expired_data*)
 432                         regional_alloc_zero(
 433                                 mstate->s.region, sizeof(struct serve_expired_data));
 434                 if(!mstate->s.serve_expired_data)
 435                         return 0;
 436         }
 437
 438         /* Don't overwrite the function if already set */
 439         mstate->s.serve_expired_data->get_cached_answer =
 440                 mstate->s.serve_expired_data->get_cached_answer?
 441                 mstate->s.serve_expired_data->get_cached_answer:
 442                 &mesh_serve_expired_lookup;
 443
 444         /* In case this timer already popped, start it again */
 445         if(!mstate->s.serve_expired_data->timer) {
 446                 mstate->s.serve_expired_data->timer = comm_timer_create(
 447                         mstate->s.env->worker_base, mesh_serve_expired_callback, mstate);
 448                 if(!mstate->s.serve_expired_data->timer)
 449                         return 0;
 450 #ifndef S_SPLINT_S
 451                 t.tv_sec = timeout/1000;
 452                 t.tv_usec = (timeout%1000)*1000;
 453 #endif
 454                 comm_timer_set(mstate->s.serve_expired_data->timer, &t);
 455         }
 456         return 1;
 457 }
 458
 459 void mesh_new_client(struct mesh_area* mesh, struct query_info* qinfo,
 460         struct respip_client_info* cinfo, uint16_t qflags,
 461         struct edns_data* edns, struct comm_reply* rep, uint16_t qid)
 462 {
 463         struct mesh_state* s = NULL;
 464         int unique = unique_mesh_state(edns->opt_list, mesh->env);
 465         int was_detached = 0;
 466         int was_noreply = 0;
 467         int added = 0;
 468         int timeout = mesh->env->cfg->serve_expired?
 469                 mesh->env->cfg->serve_expired_client_timeout:0;
 470         struct sldns_buffer* r_buffer = rep->c->buffer;
 471         if(rep->c->tcp_req_info) {
 472                 r_buffer = rep->c->tcp_req_info->spool_buffer;
 473         }
 474         if(!unique)
 475                 s = mesh_area_find(mesh, cinfo, qinfo, qflags&(BIT_RD|BIT_CD), 0, 0);
 476         /* does this create a new reply state? */
 477         if(!s || s->list_select == mesh_no_list) {
 478                 if(!mesh_make_new_space(mesh, rep->c->buffer)) {
 479                         verbose(VERB_ALGO, "Too many queries. dropping "
 480                                 "incoming query.");
 481                         comm_point_drop_reply(rep);
 482                         mesh->stats_dropped++;
 483                         return;
 484                 }
 485                 /* for this new reply state, the reply address is free,
 486                  * so the limit of reply addresses does not stop reply states*/
 487         } else {
 488                 /* protect our memory usage from storing reply addresses */
 489                 if(mesh->num_reply_addrs > mesh->max_reply_states*16) {
 490                         verbose(VERB_ALGO, "Too many requests queued. "
 491                                 "dropping incoming query.");
 492                         comm_point_drop_reply(rep);
 493                         mesh->stats_dropped++;
 494                         return;
 495                 }
 496         }
 497         /* see if it already exists, if not, create one */
 498         if(!s) {
 499 #ifdef UNBOUND_DEBUG
 500                 struct rbnode_type* n;
 501 #endif
 502                 s = mesh_state_create(mesh->env, qinfo, cinfo,
 503                         qflags&(BIT_RD|BIT_CD), 0, 0);
 504                 if(!s) {
 505                         log_err("mesh_state_create: out of memory; SERVFAIL");
 506                         if(!inplace_cb_reply_servfail_call(mesh->env, qinfo, NULL, NULL,
 507                                 LDNS_RCODE_SERVFAIL, edns, rep, mesh->env->scratch, mesh->env->now_tv))
 508                                         edns->opt_list = NULL;
 509                         error_encode(r_buffer, LDNS_RCODE_SERVFAIL,
 510                                 qinfo, qid, qflags, edns);
 511                         comm_point_send_reply(rep);
 512                         return;
 513                 }
 514                 if(unique)
 515                         mesh_state_make_unique(s);
 516                 /* copy the edns options we got from the front */
 517                 if(edns->opt_list) {
 518                         s->s.edns_opts_front_in = edns_opt_copy_region(edns->opt_list,
 519                                 s->s.region);
 520                         if(!s->s.edns_opts_front_in) {
 521                                 log_err("mesh_state_create: out of memory; SERVFAIL");
 522                                 if(!inplace_cb_reply_servfail_call(mesh->env, qinfo, NULL,
 523                                         NULL, LDNS_RCODE_SERVFAIL, edns, rep, mesh->env->scratch, mesh->env->now_tv))
 524                                                 edns->opt_list = NULL;
 525                                 error_encode(r_buffer, LDNS_RCODE_SERVFAIL,
 526                                         qinfo, qid, qflags, edns);
 527                                 comm_point_send_reply(rep);
 528                                 return;
 529                         }
 530                 }
 531
 532 #ifdef UNBOUND_DEBUG
 533                 n =
 534 #else
 535                 (void)
 536 #endif
 537                 rbtree_insert(&mesh->all, &s->node);
 538                 log_assert(n != NULL);
 539                 /* set detached (it is now) */
 540                 mesh->num_detached_states++;
 541                 added = 1;
 542         }
 543         if(!s->reply_list && !s->cb_list) {
 544                 was_noreply = 1;
 545                 if(s->super_set.count == 0) {
 546                         was_detached = 1;
 547                 }
 548         }
 549         /* add reply to s */
 550         if(!mesh_state_add_reply(s, edns, rep, qid, qflags, qinfo)) {
 551                 log_err("mesh_new_client: out of memory; SERVFAIL");
 552                 goto servfail_mem;
 553         }
 554         if(rep->c->tcp_req_info) {
 555                 if(!tcp_req_info_add_meshstate(rep->c->tcp_req_info, mesh, s)) {
 556                         log_err("mesh_new_client: out of memory add tcpreqinfo");
 557                         goto servfail_mem;
 558                 }
 559         }
 560         if(rep->c->use_h2) {
 561                 http2_stream_add_meshstate(rep->c->h2_stream, mesh, s);
 562         }
 563         /* add serve expired timer if required and not already there */
 564         if(timeout && !mesh_serve_expired_init(s, timeout)) {
 565                 log_err("mesh_new_client: out of memory initializing serve expired");
 566                 goto servfail_mem;
 567         }
 568         /* update statistics */
 569         if(was_detached) {
 570                 log_assert(mesh->num_detached_states > 0);
 571                 mesh->num_detached_states--;
 572         }
 573         if(was_noreply) {
 574                 mesh->num_reply_states ++;
 575         }
 576         mesh->num_reply_addrs++;
 577         if(s->list_select == mesh_no_list) {
 578                 /* move to either the forever or the jostle_list */
 579                 if(mesh->num_forever_states < mesh->max_forever_states) {
 580                         mesh->num_forever_states ++;
 581                         mesh_list_insert(s, &mesh->forever_first,
 582                                 &mesh->forever_last);
 583                         s->list_select = mesh_forever_list;
 584                 } else {
 585                         mesh_list_insert(s, &mesh->jostle_first,
 586                                 &mesh->jostle_last);
 587                         s->list_select = mesh_jostle_list;
 588                 }
 589         }
 590         if(added)
 591                 mesh_run(mesh, s, module_event_new, NULL);
 592         return;
 593
 594 servfail_mem:
 595         if(!inplace_cb_reply_servfail_call(mesh->env, qinfo, &s->s,
 596                 NULL, LDNS_RCODE_SERVFAIL, edns, rep, mesh->env->scratch, mesh->env->now_tv))
 597                         edns->opt_list = NULL;
 598         error_encode(r_buffer, LDNS_RCODE_SERVFAIL,
 599                 qinfo, qid, qflags, edns);
 600         comm_point_send_reply(rep);
 601         if(added)
 602                 mesh_state_delete(&s->s);
 603         return;
 604 }
 605
 606 int
 607 mesh_new_callback(struct mesh_area* mesh, struct query_info* qinfo,
 608         uint16_t qflags, struct edns_data* edns, sldns_buffer* buf,
 609         uint16_t qid, mesh_cb_func_type cb, void* cb_arg)
 610 {
 611         struct mesh_state* s = NULL;
 612         int unique = unique_mesh_state(edns->opt_list, mesh->env);
 613         int timeout = mesh->env->cfg->serve_expired?
 614                 mesh->env->cfg->serve_expired_client_timeout:0;
 615         int was_detached = 0;
 616         int was_noreply = 0;
 617         int added = 0;
 618         if(!unique)
 619                 s = mesh_area_find(mesh, NULL, qinfo, qflags&(BIT_RD|BIT_CD), 0, 0);
 620
 621         /* there are no limits on the number of callbacks */
 622
 623         /* see if it already exists, if not, create one */
 624         if(!s) {
 625 #ifdef UNBOUND_DEBUG
 626                 struct rbnode_type* n;
 627 #endif
 628                 s = mesh_state_create(mesh->env, qinfo, NULL,
 629                         qflags&(BIT_RD|BIT_CD), 0, 0);
 630                 if(!s) {
 631                         return 0;
 632                 }
 633                 if(unique)
 634                         mesh_state_make_unique(s);
 635                 if(edns->opt_list) {
 636                         s->s.edns_opts_front_in = edns_opt_copy_region(edns->opt_list,
 637                                 s->s.region);
 638                         if(!s->s.edns_opts_front_in) {
 639                                 return 0;
 640                         }
 641                 }
 642 #ifdef UNBOUND_DEBUG
 643                 n =
 644 #else
 645                 (void)
 646 #endif
 647                 rbtree_insert(&mesh->all, &s->node);
 648                 log_assert(n != NULL);
 649                 /* set detached (it is now) */
 650                 mesh->num_detached_states++;
 651                 added = 1;
 652         }
 653         if(!s->reply_list && !s->cb_list) {
 654                 was_noreply = 1;
 655                 if(s->super_set.count == 0) {
 656                         was_detached = 1;
 657                 }
 658         }
 659         /* add reply to s */
 660         if(!mesh_state_add_cb(s, edns, buf, cb, cb_arg, qid, qflags)) {
 661                 if(added)
 662                         mesh_state_delete(&s->s);
 663                 return 0;
 664         }
 665         /* add serve expired timer if not already there */
 666         if(timeout && !mesh_serve_expired_init(s, timeout)) {
 667                 return 0;
 668         }
 669         /* update statistics */
 670         if(was_detached) {
 671                 log_assert(mesh->num_detached_states > 0);
 672                 mesh->num_detached_states--;
 673         }
 674         if(was_noreply) {
 675                 mesh->num_reply_states ++;
 676         }
 677         mesh->num_reply_addrs++;
 678         if(added)
 679                 mesh_run(mesh, s, module_event_new, NULL);
 680         return 1;
 681 }
 682
 683 /* Internal backend routine of mesh_new_prefetch().  It takes one additional
 684  * parameter, 'run', which controls whether to run the prefetch state
 685  * immediately.  When this function is called internally 'run' could be
 686  * 0 (false), in which case the new state is only made runnable so it
 687  * will not be run recursively on top of the current state. */
 688 static void mesh_schedule_prefetch(struct mesh_area* mesh,
 689         struct query_info* qinfo, uint16_t qflags, time_t leeway, int run)
 690 {
 691         struct mesh_state* s = mesh_area_find(mesh, NULL, qinfo,
 692                 qflags&(BIT_RD|BIT_CD), 0, 0);
 693 #ifdef UNBOUND_DEBUG
 694         struct rbnode_type* n;
 695 #endif
 696         /* already exists, and for a different purpose perhaps.
 697          * if mesh_no_list, keep it that way. */
 698         if(s) {
 699                 /* make it ignore the cache from now on */
 700                 if(!s->s.blacklist)
 701                         sock_list_insert(&s->s.blacklist, NULL, 0, s->s.region);
 702                 if(s->s.prefetch_leeway < leeway)
 703                         s->s.prefetch_leeway = leeway;
 704                 return;
 705         }
 706         if(!mesh_make_new_space(mesh, NULL)) {
 707                 verbose(VERB_ALGO, "Too many queries. dropped prefetch.");
 708                 mesh->stats_dropped ++;
 709                 return;
 710         }
 711
 712         s = mesh_state_create(mesh->env, qinfo, NULL,
 713                 qflags&(BIT_RD|BIT_CD), 0, 0);
 714         if(!s) {
 715                 log_err("prefetch mesh_state_create: out of memory");
 716                 return;
 717         }
 718 #ifdef UNBOUND_DEBUG
 719         n =
 720 #else
 721         (void)
 722 #endif
 723         rbtree_insert(&mesh->all, &s->node);
 724         log_assert(n != NULL);
 725         /* set detached (it is now) */
 726         mesh->num_detached_states++;
 727         /* make it ignore the cache */
 728         sock_list_insert(&s->s.blacklist, NULL, 0, s->s.region);
 729         s->s.prefetch_leeway = leeway;
 730
 731         if(s->list_select == mesh_no_list) {
 732                 /* move to either the forever or the jostle_list */
 733                 if(mesh->num_forever_states < mesh->max_forever_states) {
 734                         mesh->num_forever_states ++;
 735                         mesh_list_insert(s, &mesh->forever_first,
 736                                 &mesh->forever_last);
 737                         s->list_select = mesh_forever_list;
 738                 } else {
 739                         mesh_list_insert(s, &mesh->jostle_first,
 740                                 &mesh->jostle_last);
 741                         s->list_select = mesh_jostle_list;
 742                 }
 743         }
 744
 745         if(!run) {
 746 #ifdef UNBOUND_DEBUG
 747                 n =
 748 #else
 749                 (void)
 750 #endif
 751                 rbtree_insert(&mesh->run, &s->run_node);
 752                 log_assert(n != NULL);
 753                 return;
 754         }
 755
 756         mesh_run(mesh, s, module_event_new, NULL);
 757 }
 758
 759 void mesh_new_prefetch(struct mesh_area* mesh, struct query_info* qinfo,
 760         uint16_t qflags, time_t leeway)
 761 {
 762         mesh_schedule_prefetch(mesh, qinfo, qflags, leeway, 1);
 763 }
 764
 765 void mesh_report_reply(struct mesh_area* mesh, struct outbound_entry* e,
 766         struct comm_reply* reply, int what)
 767 {
 768         enum module_ev event = module_event_reply;
 769         e->qstate->reply = reply;
 770         if(what != NETEVENT_NOERROR) {
 771                 event = module_event_noreply;
 772                 if(what == NETEVENT_CAPSFAIL)
 773                         event = module_event_capsfail;
 774         }
 775         mesh_run(mesh, e->qstate->mesh_info, event, e);
 776 }
 777
 778 struct mesh_state*
 779 mesh_state_create(struct module_env* env, struct query_info* qinfo,
 780         struct respip_client_info* cinfo, uint16_t qflags, int prime,
 781         int valrec)
 782 {
 783         struct regional* region = alloc_reg_obtain(env->alloc);
 784         struct mesh_state* mstate;
 785         int i;
 786         if(!region)
 787                 return NULL;
 788         mstate = (struct mesh_state*)regional_alloc(region,
 789                 sizeof(struct mesh_state));
 790         if(!mstate) {
 791                 alloc_reg_release(env->alloc, region);
 792                 return NULL;
 793         }
 794         memset(mstate, 0, sizeof(*mstate));
 795         mstate->node = *RBTREE_NULL;
 796         mstate->run_node = *RBTREE_NULL;
 797         mstate->node.key = mstate;
 798         mstate->run_node.key = mstate;
 799         mstate->reply_list = NULL;
 800         mstate->list_select = mesh_no_list;
 801         mstate->replies_sent = 0;
 802         rbtree_init(&mstate->super_set, &mesh_state_ref_compare);
 803         rbtree_init(&mstate->sub_set, &mesh_state_ref_compare);
 804         mstate->num_activated = 0;
 805         mstate->unique = NULL;
 806         /* init module qstate */
 807         mstate->s.qinfo.qtype = qinfo->qtype;
 808         mstate->s.qinfo.qclass = qinfo->qclass;
 809         mstate->s.qinfo.local_alias = NULL;
 810         mstate->s.qinfo.qname_len = qinfo->qname_len;
 811         mstate->s.qinfo.qname = regional_alloc_init(region, qinfo->qname,
 812                 qinfo->qname_len);
 813         if(!mstate->s.qinfo.qname) {
 814                 alloc_reg_release(env->alloc, region);
 815                 return NULL;
 816         }
 817         if(cinfo) {
 818                 mstate->s.client_info = regional_alloc_init(region, cinfo,
 819                         sizeof(*cinfo));
 820                 if(!mstate->s.client_info) {
 821                         alloc_reg_release(env->alloc, region);
 822                         return NULL;
 823                 }
 824         }
 825         /* remove all weird bits from qflags */
 826         mstate->s.query_flags = (qflags & (BIT_RD|BIT_CD));
 827         mstate->s.is_priming = prime;
 828         mstate->s.is_valrec = valrec;
 829         mstate->s.reply = NULL;
 830         mstate->s.region = region;
 831         mstate->s.curmod = 0;
 832         mstate->s.return_msg = 0;
 833         mstate->s.return_rcode = LDNS_RCODE_NOERROR;
 834         mstate->s.env = env;
 835         mstate->s.mesh_info = mstate;
 836         mstate->s.prefetch_leeway = 0;
 837         mstate->s.serve_expired_data = NULL;
 838         mstate->s.no_cache_lookup = 0;
 839         mstate->s.no_cache_store = 0;
 840         mstate->s.need_refetch = 0;
 841         mstate->s.was_ratelimited = 0;
 842
 843         /* init modules */
 844         for(i=0; i<env->mesh->mods.num; i++) {
 845                 mstate->s.minfo[i] = NULL;
 846                 mstate->s.ext_state[i] = module_state_initial;
 847         }
 848         /* init edns option lists */
 849         mstate->s.edns_opts_front_in = NULL;
 850         mstate->s.edns_opts_back_out = NULL;
 851         mstate->s.edns_opts_back_in = NULL;
 852         mstate->s.edns_opts_front_out = NULL;
 853
 854         return mstate;
 855 }
 856
 857 int
 858 mesh_state_is_unique(struct mesh_state* mstate)
 859 {
 860         return mstate->unique != NULL;
 861 }
 862
 863 void
 864 mesh_state_make_unique(struct mesh_state* mstate)
 865 {
 866         mstate->unique = mstate;
 867 }
 868
 869 void
 870 mesh_state_cleanup(struct mesh_state* mstate)
 871 {
 872         struct mesh_area* mesh;
 873         int i;
 874         if(!mstate)
 875                 return;
 876         mesh = mstate->s.env->mesh;
 877         /* Stop and delete the serve expired timer */
 878         if(mstate->s.serve_expired_data && mstate->s.serve_expired_data->timer) {
 879                 comm_timer_delete(mstate->s.serve_expired_data->timer);
 880                 mstate->s.serve_expired_data->timer = NULL;
 881         }
 882         /* drop unsent replies */
 883         if(!mstate->replies_sent) {
 884                 struct mesh_reply* rep = mstate->reply_list;
 885                 struct mesh_cb* cb;
 886                 /* in tcp_req_info, the mstates linked are removed, but
 887                  * the reply_list is now NULL, so the remove-from-empty-list
 888                  * takes no time and also it does not do the mesh accounting */
 889                 mstate->reply_list = NULL;
 890                 for(; rep; rep=rep->next) {
 891                         comm_point_drop_reply(&rep->query_reply);
 892                         log_assert(mesh->num_reply_addrs > 0);
 893                         mesh->num_reply_addrs--;
 894                 }
 895                 while((cb = mstate->cb_list)!=NULL) {
 896                         mstate->cb_list = cb->next;
 897                         fptr_ok(fptr_whitelist_mesh_cb(cb->cb));
 898                         (*cb->cb)(cb->cb_arg, LDNS_RCODE_SERVFAIL, NULL,
 899                                 sec_status_unchecked, NULL, 0);
 900                         log_assert(mesh->num_reply_addrs > 0);
 901                         mesh->num_reply_addrs--;
 902                 }
 903         }
 904
 905         /* de-init modules */
 906         for(i=0; i<mesh->mods.num; i++) {
 907                 fptr_ok(fptr_whitelist_mod_clear(mesh->mods.mod[i]->clear));
 908                 (*mesh->mods.mod[i]->clear)(&mstate->s, i);
 909                 mstate->s.minfo[i] = NULL;
 910                 mstate->s.ext_state[i] = module_finished;
 911         }
 912         alloc_reg_release(mstate->s.env->alloc, mstate->s.region);
 913 }
 914
 915 void
 916 mesh_state_delete(struct module_qstate* qstate)
 917 {
 918         struct mesh_area* mesh;
 919         struct mesh_state_ref* super, ref;
 920         struct mesh_state* mstate;
 921         if(!qstate)
 922                 return;
 923         mstate = qstate->mesh_info;
 924         mesh = mstate->s.env->mesh;
 925         mesh_detach_subs(&mstate->s);
 926         if(mstate->list_select == mesh_forever_list) {
 927                 mesh->num_forever_states --;
 928                 mesh_list_remove(mstate, &mesh->forever_first,
 929                         &mesh->forever_last);
 930         } else if(mstate->list_select == mesh_jostle_list) {
 931                 mesh_list_remove(mstate, &mesh->jostle_first,
 932                         &mesh->jostle_last);
 933         }
 934         if(!mstate->reply_list && !mstate->cb_list
 935                 && mstate->super_set.count == 0) {
 936                 log_assert(mesh->num_detached_states > 0);
 937                 mesh->num_detached_states--;
 938         }
 939         if(mstate->reply_list || mstate->cb_list) {
 940                 log_assert(mesh->num_reply_states > 0);
 941                 mesh->num_reply_states--;
 942         }
 943         ref.node.key = &ref;
 944         ref.s = mstate;
 945         RBTREE_FOR(super, struct mesh_state_ref*, &mstate->super_set) {
 946                 (void)rbtree_delete(&super->s->sub_set, &ref);
 947         }
 948         (void)rbtree_delete(&mesh->run, mstate);
 949         (void)rbtree_delete(&mesh->all, mstate);
 950         mesh_state_cleanup(mstate);
 951 }
 952
 953 /** helper recursive rbtree find routine */
 954 static int
 955 find_in_subsub(struct mesh_state* m, struct mesh_state* tofind, size_t *c)
 956 {
 957         struct mesh_state_ref* r;
 958         if((*c)++ > MESH_MAX_SUBSUB)
 959                 return 1;
 960         RBTREE_FOR(r, struct mesh_state_ref*, &m->sub_set) {
 961                 if(r->s == tofind || find_in_subsub(r->s, tofind, c))
 962                         return 1;
 963         }
 964         return 0;
 965 }
 966
 967 /** find cycle for already looked up mesh_state */
 968 static int
 969 mesh_detect_cycle_found(struct module_qstate* qstate, struct mesh_state* dep_m)
 970 {
 971         struct mesh_state* cyc_m = qstate->mesh_info;
 972         size_t counter = 0;
 973         if(!dep_m)
 974                 return 0;
 975         if(dep_m == cyc_m || find_in_subsub(dep_m, cyc_m, &counter)) {
 976                 if(counter > MESH_MAX_SUBSUB)
 977                         return 2;
 978                 return 1;
 979         }
 980         return 0;
 981 }
 982
 983 void mesh_detach_subs(struct module_qstate* qstate)
 984 {
 985         struct mesh_area* mesh = qstate->env->mesh;
 986         struct mesh_state_ref* ref, lookup;
 987 #ifdef UNBOUND_DEBUG
 988         struct rbnode_type* n;
 989 #endif
 990         lookup.node.key = &lookup;
 991         lookup.s = qstate->mesh_info;
 992         RBTREE_FOR(ref, struct mesh_state_ref*, &qstate->mesh_info->sub_set) {
 993 #ifdef UNBOUND_DEBUG
 994                 n =
 995 #else
 996                 (void)
 997 #endif
 998                 rbtree_delete(&ref->s->super_set, &lookup);
 999                 log_assert(n != NULL); /* must have been present */
1000                 if(!ref->s->reply_list && !ref->s->cb_list
1001                         && ref->s->super_set.count == 0) {
1002                         mesh->num_detached_states++;
1003                         log_assert(mesh->num_detached_states +
1004                                 mesh->num_reply_states <= mesh->all.count);
1005                 }
1006         }
1007         rbtree_init(&qstate->mesh_info->sub_set, &mesh_state_ref_compare);
1008 }
1009
1010 int mesh_add_sub(struct module_qstate* qstate, struct query_info* qinfo,
1011         uint16_t qflags, int prime, int valrec, struct module_qstate** newq,
1012         struct mesh_state** sub)
1013 {
1014         /* find it, if not, create it */
1015         struct mesh_area* mesh = qstate->env->mesh;
1016         *sub = mesh_area_find(mesh, NULL, qinfo, qflags,
1017                 prime, valrec);
1018         if(mesh_detect_cycle_found(qstate, *sub)) {
1019                 verbose(VERB_ALGO, "attach failed, cycle detected");
1020                 return 0;
1021         }
1022         if(!*sub) {
1023 #ifdef UNBOUND_DEBUG
1024                 struct rbnode_type* n;
1025 #endif
1026                 /* create a new one */
1027                 *sub = mesh_state_create(qstate->env, qinfo, NULL, qflags, prime,
1028                         valrec);
1029                 if(!*sub) {
1030                         log_err("mesh_attach_sub: out of memory");
1031                         return 0;
1032                 }
1033 #ifdef UNBOUND_DEBUG
1034                 n =
1035 #else
1036                 (void)
1037 #endif
1038                 rbtree_insert(&mesh->all, &(*sub)->node);
1039                 log_assert(n != NULL);
1040                 /* set detached (it is now) */
1041                 mesh->num_detached_states++;
1042                 /* set new query state to run */
1043 #ifdef UNBOUND_DEBUG
1044                 n =
1045 #else
1046                 (void)
1047 #endif
1048                 rbtree_insert(&mesh->run, &(*sub)->run_node);
1049                 log_assert(n != NULL);
1050                 *newq = &(*sub)->s;
1051         } else
1052                 *newq = NULL;
1053         return 1;
1054 }
1055
1056 int mesh_attach_sub(struct module_qstate* qstate, struct query_info* qinfo,
1057         uint16_t qflags, int prime, int valrec, struct module_qstate** newq)
1058 {
1059         struct mesh_area* mesh = qstate->env->mesh;
1060         struct mesh_state* sub = NULL;
1061         int was_detached;
1062         if(!mesh_add_sub(qstate, qinfo, qflags, prime, valrec, newq, &sub))
1063                 return 0;
1064         was_detached = (sub->super_set.count == 0);
1065         if(!mesh_state_attachment(qstate->mesh_info, sub))
1066                 return 0;
1067         /* if it was a duplicate  attachment, the count was not zero before */
1068         if(!sub->reply_list && !sub->cb_list && was_detached &&
1069                 sub->super_set.count == 1) {
1070                 /* it used to be detached, before this one got added */
1071                 log_assert(mesh->num_detached_states > 0);
1072                 mesh->num_detached_states--;
1073         }
1074         /* *newq will be run when inited after the current module stops */
1075         return 1;
1076 }
1077
1078 int mesh_state_attachment(struct mesh_state* super, struct mesh_state* sub)
1079 {
1080 #ifdef UNBOUND_DEBUG
1081         struct rbnode_type* n;
1082 #endif
1083         struct mesh_state_ref* subref; /* points to sub, inserted in super */
1084         struct mesh_state_ref* superref; /* points to super, inserted in sub */
1085         if( !(subref = regional_alloc(super->s.region,
1086                 sizeof(struct mesh_state_ref))) ||
1087                 !(superref = regional_alloc(sub->s.region,
1088                 sizeof(struct mesh_state_ref))) ) {
1089                 log_err("mesh_state_attachment: out of memory");
1090                 return 0;
1091         }
1092         superref->node.key = superref;
1093         superref->s = super;
1094         subref->node.key = subref;
1095         subref->s = sub;
1096         if(!rbtree_insert(&sub->super_set, &superref->node)) {
1097                 /* this should not happen, iterator and validator do not
1098                  * attach subqueries that are identical. */
1099                 /* already attached, we are done, nothing todo.
1100                  * since superref and subref already allocated in region,
1101                  * we cannot free them */
1102                 return 1;
1103         }
1104 #ifdef UNBOUND_DEBUG
1105         n =
1106 #else
1107         (void)
1108 #endif
1109         rbtree_insert(&super->sub_set, &subref->node);
1110         log_assert(n != NULL); /* we checked above if statement, the reverse
1111           administration should not fail now, unless they are out of sync */
1112         return 1;
1113 }
1114
1115 /**
1116  * callback results to mesh cb entry
1117  * @param m: mesh state to send it for.
1118  * @param rcode: if not 0, error code.
1119  * @param rep: reply to send (or NULL if rcode is set).
1120  * @param r: callback entry
1121  * @param start_time: the time to pass to callback functions, it is 0 or
1122  *      a value from one of the packets if the mesh state had packets.
1123  */
1124 static void
1125 mesh_do_callback(struct mesh_state* m, int rcode, struct reply_info* rep,
1126         struct mesh_cb* r, struct timeval* start_time)
1127 {
1128         int secure;
1129         char* reason = NULL;
1130         int was_ratelimited = m->s.was_ratelimited;
1131         /* bogus messages are not made into servfail, sec_status passed
1132          * to the callback function */
1133         if(rep && rep->security == sec_status_secure)
1134                 secure = 1;
1135         else    secure = 0;
1136         if(!rep && rcode == LDNS_RCODE_NOERROR)
1137                 rcode = LDNS_RCODE_SERVFAIL;
1138         if(!rcode && (rep->security == sec_status_bogus ||
1139                 rep->security == sec_status_secure_sentinel_fail)) {
1140                 if(!(reason = errinf_to_str_bogus(&m->s)))
1141                         rcode = LDNS_RCODE_SERVFAIL;
1142         }
1143         /* send the reply */
1144         if(rcode) {
1145                 if(rcode == LDNS_RCODE_SERVFAIL) {
1146                         if(!inplace_cb_reply_servfail_call(m->s.env, &m->s.qinfo, &m->s,
1147                                 rep, rcode, &r->edns, NULL, m->s.region, start_time))
1148                                         r->edns.opt_list = NULL;
1149                 } else {
1150                         if(!inplace_cb_reply_call(m->s.env, &m->s.qinfo, &m->s, rep, rcode,
1151                                 &r->edns, NULL, m->s.region, start_time))
1152                                         r->edns.opt_list = NULL;
1153                 }
1154                 fptr_ok(fptr_whitelist_mesh_cb(r->cb));
1155                 (*r->cb)(r->cb_arg, rcode, r->buf, sec_status_unchecked, NULL,
1156                         was_ratelimited);
1157         } else {
1158                 size_t udp_size = r->edns.udp_size;
1159                 sldns_buffer_clear(r->buf);
1160                 r->edns.edns_version = EDNS_ADVERTISED_VERSION;
1161                 r->edns.udp_size = EDNS_ADVERTISED_SIZE;
1162                 r->edns.ext_rcode = 0;
1163                 r->edns.bits &= EDNS_DO;
1164
1165                 if(!inplace_cb_reply_call(m->s.env, &m->s.qinfo, &m->s, rep,
1166                         LDNS_RCODE_NOERROR, &r->edns, NULL, m->s.region, start_time) ||
1167                         !reply_info_answer_encode(&m->s.qinfo, rep, r->qid,
1168                         r->qflags, r->buf, 0, 1,
1169                         m->s.env->scratch, udp_size, &r->edns,
1170                         (int)(r->edns.bits & EDNS_DO), secure))
1171                 {
1172                         fptr_ok(fptr_whitelist_mesh_cb(r->cb));
1173                         (*r->cb)(r->cb_arg, LDNS_RCODE_SERVFAIL, r->buf,
1174                                 sec_status_unchecked, NULL, 0);
1175                 } else {
1176                         fptr_ok(fptr_whitelist_mesh_cb(r->cb));
1177                         (*r->cb)(r->cb_arg, LDNS_RCODE_NOERROR, r->buf,
1178                                 rep->security, reason, was_ratelimited);
1179                 }
1180         }
1181         free(reason);
1182         log_assert(m->s.env->mesh->num_reply_addrs > 0);
1183         m->s.env->mesh->num_reply_addrs--;
1184 }
1185
1186 /**
1187  * Send reply to mesh reply entry
1188  * @param m: mesh state to send it for.
1189  * @param rcode: if not 0, error code.
1190  * @param rep: reply to send (or NULL if rcode is set).
1191  * @param r: reply entry
1192  * @param r_buffer: buffer to use for reply entry.
1193  * @param prev: previous reply, already has its answer encoded in buffer.
1194  * @param prev_buffer: buffer for previous reply.
1195  */
1196 static void
1197 mesh_send_reply(struct mesh_state* m, int rcode, struct reply_info* rep,
1198         struct mesh_reply* r, struct sldns_buffer* r_buffer,
1199         struct mesh_reply* prev, struct sldns_buffer* prev_buffer)
1200 {
1201         struct timeval end_time;
1202         struct timeval duration;
1203         int secure;
1204         /* Copy the client's EDNS for later restore, to make sure the edns
1205          * compare is with the correct edns options. */
1206         struct edns_data edns_bak = r->edns;
1207         /* briefly set the replylist to null in case the
1208          * meshsendreply calls tcpreqinfo sendreply that
1209          * comm_point_drops because of size, and then the
1210          * null stops the mesh state remove and thus
1211          * reply_list modification and accounting */
1212         struct mesh_reply* rlist = m->reply_list;
1213         /* examine security status */
1214         if(m->s.env->need_to_validate && (!(r->qflags&BIT_CD) ||
1215                 m->s.env->cfg->ignore_cd) && rep &&
1216                 (rep->security <= sec_status_bogus ||
1217                 rep->security == sec_status_secure_sentinel_fail)) {
1218                 rcode = LDNS_RCODE_SERVFAIL;
1219                 if(m->s.env->cfg->stat_extended)
1220                         m->s.env->mesh->ans_bogus++;
1221         }
1222         if(rep && rep->security == sec_status_secure)
1223                 secure = 1;
1224         else    secure = 0;
1225         if(!rep && rcode == LDNS_RCODE_NOERROR)
1226                 rcode = LDNS_RCODE_SERVFAIL;
1227         if(r->query_reply.c->use_h2) {
1228                 r->query_reply.c->h2_stream = r->h2_stream;
1229                 /* Mesh reply won't exist for long anymore. Make it impossible
1230                  * for HTTP/2 stream to refer to mesh state, in case
1231                  * connection gets cleanup before HTTP/2 stream close. */
1232                 r->h2_stream->mesh_state = NULL;
1233         }
1234         /* send the reply */
1235         /* We don't reuse the encoded answer if:
1236          * - either the previous or current response has a local alias.  We could
1237          *   compare the alias records and still reuse the previous answer if they
1238          *   are the same, but that would be complicated and error prone for the
1239          *   relatively minor case. So we err on the side of safety.
1240          * - there are registered callback functions for the given rcode, as these
1241          *   need to be called for each reply. */
1242         if(((rcode != LDNS_RCODE_SERVFAIL &&
1243                         !m->s.env->inplace_cb_lists[inplace_cb_reply]) ||
1244                 (rcode == LDNS_RCODE_SERVFAIL &&
1245                         !m->s.env->inplace_cb_lists[inplace_cb_reply_servfail])) &&
1246                 prev && prev_buffer && prev->qflags == r->qflags &&
1247                 !prev->local_alias && !r->local_alias &&
1248                 prev->edns.edns_present == r->edns.edns_present &&
1249                 prev->edns.bits == r->edns.bits &&
1250                 prev->edns.udp_size == r->edns.udp_size &&
1251                 edns_opt_list_compare(prev->edns.opt_list, r->edns.opt_list)
1252                 == 0) {
1253                 /* if the previous reply is identical to this one, fix ID */
1254                 if(prev_buffer != r_buffer)
1255                         sldns_buffer_copy(r_buffer, prev_buffer);
1256                 sldns_buffer_write_at(r_buffer, 0, &r->qid, sizeof(uint16_t));
1257                 sldns_buffer_write_at(r_buffer, 12, r->qname,
1258                         m->s.qinfo.qname_len);
1259                 m->reply_list = NULL;
1260                 comm_point_send_reply(&r->query_reply);
1261                 m->reply_list = rlist;
1262         } else if(rcode) {
1263                 m->s.qinfo.qname = r->qname;
1264                 m->s.qinfo.local_alias = r->local_alias;
1265                 if(rcode == LDNS_RCODE_SERVFAIL) {
1266                         if(!inplace_cb_reply_servfail_call(m->s.env, &m->s.qinfo, &m->s,
1267                                 rep, rcode, &r->edns, &r->query_reply, m->s.region, &r->start_time))
1268                                         r->edns.opt_list = NULL;
1269                 } else {
1270                         if(!inplace_cb_reply_call(m->s.env, &m->s.qinfo, &m->s, rep, rcode,
1271                                 &r->edns, &r->query_reply, m->s.region, &r->start_time))
1272                                         r->edns.opt_list = NULL;
1273                 }
1274                 error_encode(r_buffer, rcode, &m->s.qinfo, r->qid,
1275                         r->qflags, &r->edns);
1276                 m->reply_list = NULL;
1277                 comm_point_send_reply(&r->query_reply);
1278                 m->reply_list = rlist;
1279         } else {
1280                 size_t udp_size = r->edns.udp_size;
1281                 r->edns.edns_version = EDNS_ADVERTISED_VERSION;
1282                 r->edns.udp_size = EDNS_ADVERTISED_SIZE;
1283                 r->edns.ext_rcode = 0;
1284                 r->edns.bits &= EDNS_DO;
1285                 m->s.qinfo.qname = r->qname;
1286                 m->s.qinfo.local_alias = r->local_alias;
1287                 if(!inplace_cb_reply_call(m->s.env, &m->s.qinfo, &m->s, rep,
1288                         LDNS_RCODE_NOERROR, &r->edns, &r->query_reply, m->s.region, &r->start_time) ||
1289                         !apply_edns_options(&r->edns, &edns_bak,
1290                                 m->s.env->cfg, r->query_reply.c,
1291                                 m->s.region) ||
1292                         !reply_info_answer_encode(&m->s.qinfo, rep, r->qid,
1293                         r->qflags, r_buffer, 0, 1, m->s.env->scratch,
1294                         udp_size, &r->edns, (int)(r->edns.bits & EDNS_DO),
1295                         secure))
1296                 {
1297                         if(!inplace_cb_reply_servfail_call(m->s.env, &m->s.qinfo, &m->s,
1298                         rep, LDNS_RCODE_SERVFAIL, &r->edns, &r->query_reply, m->s.region, &r->start_time))
1299                                 r->edns.opt_list = NULL;
1300                         error_encode(r_buffer, LDNS_RCODE_SERVFAIL,
1301                                 &m->s.qinfo, r->qid, r->qflags, &r->edns);
1302                 }
1303                 r->edns = edns_bak;
1304                 m->reply_list = NULL;
1305                 comm_point_send_reply(&r->query_reply);
1306                 m->reply_list = rlist;
1307         }
1308         /* account */
1309         log_assert(m->s.env->mesh->num_reply_addrs > 0);
1310         m->s.env->mesh->num_reply_addrs--;
1311         end_time = *m->s.env->now_tv;
1312         timeval_subtract(&duration, &end_time, &r->start_time);
1313         verbose(VERB_ALGO, "query took " ARG_LL "d.%6.6d sec",
1314                 (long long)duration.tv_sec, (int)duration.tv_usec);
1315         m->s.env->mesh->replies_sent++;
1316         timeval_add(&m->s.env->mesh->replies_sum_wait, &duration);
1317         timehist_insert(m->s.env->mesh->histogram, &duration);
1318         if(m->s.env->cfg->stat_extended) {
1319                 uint16_t rc = FLAGS_GET_RCODE(sldns_buffer_read_u16_at(
1320                         r_buffer, 2));
1321                 if(secure) m->s.env->mesh->ans_secure++;
1322                 m->s.env->mesh->ans_rcode[ rc ] ++;
1323                 if(rc == 0 && LDNS_ANCOUNT(sldns_buffer_begin(r_buffer)) == 0)
1324                         m->s.env->mesh->ans_nodata++;
1325         }
1326         /* Log reply sent */
1327         if(m->s.env->cfg->log_replies) {
1328                 log_reply_info(NO_VERBOSE, &m->s.qinfo, &r->query_reply.addr,
1329                         r->query_reply.addrlen, duration, 0, r_buffer);
1330         }
1331 }
1332
1333 void mesh_query_done(struct mesh_state* mstate)
1334 {
1335         struct mesh_reply* r;
1336         struct mesh_reply* prev = NULL;
1337         struct sldns_buffer* prev_buffer = NULL;
1338         struct mesh_cb* c;
1339         struct reply_info* rep = (mstate->s.return_msg?
1340                 mstate->s.return_msg->rep:NULL);
1341         struct timeval tv = {0, 0};
1342         /* No need for the serve expired timer anymore; we are going to reply. */
1343         if(mstate->s.serve_expired_data) {
1344                 comm_timer_delete(mstate->s.serve_expired_data->timer);
1345                 mstate->s.serve_expired_data->timer = NULL;
1346         }
1347         if(mstate->s.return_rcode == LDNS_RCODE_SERVFAIL ||
1348                 (rep && FLAGS_GET_RCODE(rep->flags) == LDNS_RCODE_SERVFAIL)) {
1349                 /* we are SERVFAILing; check for expired asnwer here */
1350                 mesh_serve_expired_callback(mstate);
1351                 if((mstate->reply_list || mstate->cb_list)
1352                 && mstate->s.env->cfg->log_servfail
1353                 && !mstate->s.env->cfg->val_log_squelch) {
1354                         char* err = errinf_to_str_servfail(&mstate->s);
1355                         if(err)
1356                                 log_err("%s", err);
1357                         free(err);
1358                 }
1359         }
1360         for(r = mstate->reply_list; r; r = r->next) {
1361                 tv = r->start_time;
1362
1363                 /* if a response-ip address block has been stored the
1364                  *  information should be logged for each client. */
1365                 if(mstate->s.respip_action_info &&
1366                         mstate->s.respip_action_info->addrinfo) {
1367                         respip_inform_print(mstate->s.respip_action_info,
1368                                 r->qname, mstate->s.qinfo.qtype,
1369                                 mstate->s.qinfo.qclass, r->local_alias,
1370                                 &r->query_reply);
1371                         if(mstate->s.env->cfg->stat_extended &&
1372                                 mstate->s.respip_action_info->rpz_used) {
1373                                 if(mstate->s.respip_action_info->rpz_disabled)
1374                                         mstate->s.env->mesh->rpz_action[RPZ_DISABLED_ACTION]++;
1375                                 if(mstate->s.respip_action_info->rpz_cname_override)
1376                                         mstate->s.env->mesh->rpz_action[RPZ_CNAME_OVERRIDE_ACTION]++;
1377                                 else
1378                                         mstate->s.env->mesh->rpz_action[respip_action_to_rpz_action(
1379                                                 mstate->s.respip_action_info->action)]++;
1380                         }
1381                 }
1382
1383                 /* if this query is determined to be dropped during the
1384                  * mesh processing, this is the point to take that action. */
1385                 if(mstate->s.is_drop) {
1386                         /* briefly set the reply_list to NULL, so that the
1387                          * tcp req info cleanup routine that calls the mesh
1388                          * to deregister the meshstate for it is not done
1389                          * because the list is NULL and also accounting is not
1390                          * done there, but instead we do that here. */
1391                         struct mesh_reply* reply_list = mstate->reply_list;
1392                         mstate->reply_list = NULL;
1393                         comm_point_drop_reply(&r->query_reply);
1394                         mstate->reply_list = reply_list;
1395                 } else {
1396                         struct sldns_buffer* r_buffer = r->query_reply.c->buffer;
1397                         if(r->query_reply.c->tcp_req_info) {
1398                                 r_buffer = r->query_reply.c->tcp_req_info->spool_buffer;
1399                                 prev_buffer = NULL;
1400                         }
1401                         mesh_send_reply(mstate, mstate->s.return_rcode, rep,
1402                                 r, r_buffer, prev, prev_buffer);
1403                         if(r->query_reply.c->tcp_req_info) {
1404                                 tcp_req_info_remove_mesh_state(r->query_reply.c->tcp_req_info, mstate);
1405                                 r_buffer = NULL;
1406                         }
1407                         prev = r;
1408                         prev_buffer = r_buffer;
1409                 }
1410         }
1411         if(mstate->reply_list) {
1412                 mstate->reply_list = NULL;
1413                 if(!mstate->reply_list && !mstate->cb_list) {
1414                         /* was a reply state, not anymore */
1415                         log_assert(mstate->s.env->mesh->num_reply_states > 0);
1416                         mstate->s.env->mesh->num_reply_states--;
1417                 }
1418                 if(!mstate->reply_list && !mstate->cb_list &&
1419                         mstate->super_set.count == 0)
1420                         mstate->s.env->mesh->num_detached_states++;
1421         }
1422         mstate->replies_sent = 1;
1423         while((c = mstate->cb_list) != NULL) {
1424                 /* take this cb off the list; so that the list can be
1425                  * changed, eg. by adds from the callback routine */
1426                 if(!mstate->reply_list && mstate->cb_list && !c->next) {
1427                         /* was a reply state, not anymore */
1428                         log_assert(mstate->s.env->mesh->num_reply_states > 0);
1429                         mstate->s.env->mesh->num_reply_states--;
1430                 }
1431                 mstate->cb_list = c->next;
1432                 if(!mstate->reply_list && !mstate->cb_list &&
1433                         mstate->super_set.count == 0)
1434                         mstate->s.env->mesh->num_detached_states++;
1435                 mesh_do_callback(mstate, mstate->s.return_rcode, rep, c, &tv);
1436         }
1437 }
1438
1439 void mesh_walk_supers(struct mesh_area* mesh, struct mesh_state* mstate)
1440 {
1441         struct mesh_state_ref* ref;
1442         RBTREE_FOR(ref, struct mesh_state_ref*, &mstate->super_set)
1443         {
1444                 /* make super runnable */
1445                 (void)rbtree_insert(&mesh->run, &ref->s->run_node);
1446                 /* callback the function to inform super of result */
1447                 fptr_ok(fptr_whitelist_mod_inform_super(
1448                         mesh->mods.mod[ref->s->s.curmod]->inform_super));
1449                 (*mesh->mods.mod[ref->s->s.curmod]->inform_super)(&mstate->s,
1450                         ref->s->s.curmod, &ref->s->s);
1451                 /* copy state that is always relevant to super */
1452                 copy_state_to_super(&mstate->s, ref->s->s.curmod, &ref->s->s);
1453         }
1454 }
1455
1456 struct mesh_state* mesh_area_find(struct mesh_area* mesh,
1457         struct respip_client_info* cinfo, struct query_info* qinfo,
1458         uint16_t qflags, int prime, int valrec)
1459 {
1460         struct mesh_state key;
1461         struct mesh_state* result;
1462
1463         key.node.key = &key;
1464         key.s.is_priming = prime;
1465         key.s.is_valrec = valrec;
1466         key.s.qinfo = *qinfo;
1467         key.s.query_flags = qflags;
1468         /* We are searching for a similar mesh state when we DO want to
1469          * aggregate the state. Thus unique is set to NULL. (default when we
1470          * desire aggregation).*/
1471         key.unique = NULL;
1472         key.s.client_info = cinfo;
1473
1474         result = (struct mesh_state*)rbtree_search(&mesh->all, &key);
1475         return result;
1476 }
1477
1478 int mesh_state_add_cb(struct mesh_state* s, struct edns_data* edns,
1479         sldns_buffer* buf, mesh_cb_func_type cb, void* cb_arg,
1480         uint16_t qid, uint16_t qflags)
1481 {
1482         struct mesh_cb* r = regional_alloc(s->s.region,
1483                 sizeof(struct mesh_cb));
1484         if(!r)
1485                 return 0;
1486         r->buf = buf;
1487         log_assert(fptr_whitelist_mesh_cb(cb)); /* early failure ifmissing*/
1488         r->cb = cb;
1489         r->cb_arg = cb_arg;
1490         r->edns = *edns;
1491         if(edns->opt_list) {
1492                 r->edns.opt_list = edns_opt_copy_region(edns->opt_list,
1493                         s->s.region);
1494                 if(!r->edns.opt_list)
1495                         return 0;
1496         }
1497         r->qid = qid;
1498         r->qflags = qflags;
1499         r->next = s->cb_list;
1500         s->cb_list = r;
1501         return 1;
1502
1503 }
1504
1505 int mesh_state_add_reply(struct mesh_state* s, struct edns_data* edns,
1506         struct comm_reply* rep, uint16_t qid, uint16_t qflags,
1507         const struct query_info* qinfo)
1508 {
1509         struct mesh_reply* r = regional_alloc(s->s.region,
1510                 sizeof(struct mesh_reply));
1511         if(!r)
1512                 return 0;
1513         r->query_reply = *rep;
1514         r->edns = *edns;
1515         if(edns->opt_list) {
1516                 r->edns.opt_list = edns_opt_copy_region(edns->opt_list,
1517                         s->s.region);
1518                 if(!r->edns.opt_list)
1519                         return 0;
1520         }
1521         r->qid = qid;
1522         r->qflags = qflags;
1523         r->start_time = *s->s.env->now_tv;
1524         r->next = s->reply_list;
1525         r->qname = regional_alloc_init(s->s.region, qinfo->qname,
1526                 s->s.qinfo.qname_len);
1527         if(!r->qname)
1528                 return 0;
1529         if(rep->c->use_h2)
1530                 r->h2_stream = rep->c->h2_stream;
1531
1532         /* Data related to local alias stored in 'qinfo' (if any) is ephemeral
1533          * and can be different for different original queries (even if the
1534          * replaced query name is the same).  So we need to make a deep copy
1535          * and store the copy for each reply info. */
1536         if(qinfo->local_alias) {
1537                 struct packed_rrset_data* d;
1538                 struct packed_rrset_data* dsrc;
1539                 r->local_alias = regional_alloc_zero(s->s.region,
1540                         sizeof(*qinfo->local_alias));
1541                 if(!r->local_alias)
1542                         return 0;
1543                 r->local_alias->rrset = regional_alloc_init(s->s.region,
1544                         qinfo->local_alias->rrset,
1545                         sizeof(*qinfo->local_alias->rrset));
1546                 if(!r->local_alias->rrset)
1547                         return 0;
1548                 dsrc = qinfo->local_alias->rrset->entry.data;
1549
1550                 /* In the current implementation, a local alias must be
1551                  * a single CNAME RR (see worker_handle_request()). */
1552                 log_assert(!qinfo->local_alias->next && dsrc->count == 1 &&
1553                         qinfo->local_alias->rrset->rk.type ==
1554                         htons(LDNS_RR_TYPE_CNAME));
1555                 /* we should make a local copy for the owner name of
1556                  * the RRset */
1557                 r->local_alias->rrset->rk.dname_len =
1558                         qinfo->local_alias->rrset->rk.dname_len;
1559                 r->local_alias->rrset->rk.dname = regional_alloc_init(
1560                         s->s.region, qinfo->local_alias->rrset->rk.dname,
1561                         qinfo->local_alias->rrset->rk.dname_len);
1562                 if(!r->local_alias->rrset->rk.dname)
1563                         return 0;
1564
1565                 /* the rrset is not packed, like in the cache, but it is
1566                  * individualy allocated with an allocator from localzone. */
1567                 d = regional_alloc_zero(s->s.region, sizeof(*d));
1568                 if(!d)
1569                         return 0;
1570                 r->local_alias->rrset->entry.data = d;
1571                 if(!rrset_insert_rr(s->s.region, d, dsrc->rr_data[0],
1572                         dsrc->rr_len[0], dsrc->rr_ttl[0], "CNAME local alias"))
1573                         return 0;
1574         } else
1575                 r->local_alias = NULL;
1576
1577         s->reply_list = r;
1578         return 1;
1579 }
1580
1581 /* Extract the query info and flags from 'mstate' into '*qinfop' and '*qflags'.
1582  * Since this is only used for internal refetch of otherwise-expired answer,
1583  * we simply ignore the rare failure mode when memory allocation fails. */
1584 static void
1585 mesh_copy_qinfo(struct mesh_state* mstate, struct query_info** qinfop,
1586         uint16_t* qflags)
1587 {
1588         struct regional* region = mstate->s.env->scratch;
1589         struct query_info* qinfo;
1590
1591         qinfo = regional_alloc_init(region, &mstate->s.qinfo, sizeof(*qinfo));
1592         if(!qinfo)
1593                 return;
1594         qinfo->qname = regional_alloc_init(region, qinfo->qname,
1595                 qinfo->qname_len);
1596         if(!qinfo->qname)
1597                 return;
1598         *qinfop = qinfo;
1599         *qflags = mstate->s.query_flags;
1600 }
1601
1602 /**
1603  * Continue processing the mesh state at another module.
1604  * Handles module to modules transfer of control.
1605  * Handles module finished.
1606  * @param mesh: the mesh area.
1607  * @param mstate: currently active mesh state.
1608  *      Deleted if finished, calls _done and _supers to
1609  *      send replies to clients and inform other mesh states.
1610  *      This in turn may create additional runnable mesh states.
1611  * @param s: state at which the current module exited.
1612  * @param ev: the event sent to the module.
1613  *      returned is the event to send to the next module.
1614  * @return true if continue processing at the new module.
1615  *      false if not continued processing is needed.
1616  */
1617 static int
1618 mesh_continue(struct mesh_area* mesh, struct mesh_state* mstate,
1619         enum module_ext_state s, enum module_ev* ev)
1620 {
1621         mstate->num_activated++;
1622         if(mstate->num_activated > MESH_MAX_ACTIVATION) {
1623                 /* module is looping. Stop it. */
1624                 log_err("internal error: looping module (%s) stopped",
1625                         mesh->mods.mod[mstate->s.curmod]->name);
1626                 log_query_info(NO_VERBOSE, "pass error for qstate",
1627                         &mstate->s.qinfo);
1628                 s = module_error;
1629         }
1630         if(s == module_wait_module || s == module_restart_next) {
1631                 /* start next module */
1632                 mstate->s.curmod++;
1633                 if(mesh->mods.num == mstate->s.curmod) {
1634                         log_err("Cannot pass to next module; at last module");
1635                         log_query_info(VERB_QUERY, "pass error for qstate",
1636                                 &mstate->s.qinfo);
1637                         mstate->s.curmod--;
1638                         return mesh_continue(mesh, mstate, module_error, ev);
1639                 }
1640                 if(s == module_restart_next) {
1641                         int curmod = mstate->s.curmod;
1642                         for(; mstate->s.curmod < mesh->mods.num;
1643                                 mstate->s.curmod++) {
1644                                 fptr_ok(fptr_whitelist_mod_clear(
1645                                         mesh->mods.mod[mstate->s.curmod]->clear));
1646                                 (*mesh->mods.mod[mstate->s.curmod]->clear)
1647                                         (&mstate->s, mstate->s.curmod);
1648                                 mstate->s.minfo[mstate->s.curmod] = NULL;
1649                         }
1650                         mstate->s.curmod = curmod;
1651                 }
1652                 *ev = module_event_pass;
1653                 return 1;
1654         }
1655         if(s == module_wait_subquery && mstate->sub_set.count == 0) {
1656                 log_err("module cannot wait for subquery, subquery list empty");
1657                 log_query_info(VERB_QUERY, "pass error for qstate",
1658                         &mstate->s.qinfo);
1659                 s = module_error;
1660         }
1661         if(s == module_error && mstate->s.return_rcode == LDNS_RCODE_NOERROR) {
1662                 /* error is bad, handle pass back up below */
1663                 mstate->s.return_rcode = LDNS_RCODE_SERVFAIL;
1664         }
1665         if(s == module_error) {
1666                 mesh_query_done(mstate);
1667                 mesh_walk_supers(mesh, mstate);
1668                 mesh_state_delete(&mstate->s);
1669                 return 0;
1670         }
1671         if(s == module_finished) {
1672                 if(mstate->s.curmod == 0) {
1673                         struct query_info* qinfo = NULL;
1674                         uint16_t qflags;
1675
1676                         mesh_query_done(mstate);
1677                         mesh_walk_supers(mesh, mstate);
1678
1679                         /* If the answer to the query needs to be refetched
1680                          * from an external DNS server, we'll need to schedule
1681                          * a prefetch after removing the current state, so
1682                          * we need to make a copy of the query info here. */
1683                         if(mstate->s.need_refetch)
1684                                 mesh_copy_qinfo(mstate, &qinfo, &qflags);
1685
1686                         mesh_state_delete(&mstate->s);
1687                         if(qinfo) {
1688                                 mesh_schedule_prefetch(mesh, qinfo, qflags,
1689                                         0, 1);
1690                         }
1691                         return 0;
1692                 }
1693                 /* pass along the locus of control */
1694                 mstate->s.curmod --;
1695                 *ev = module_event_moddone;
1696                 return 1;
1697         }
1698         return 0;
1699 }
1700
1701 void mesh_run(struct mesh_area* mesh, struct mesh_state* mstate,
1702         enum module_ev ev, struct outbound_entry* e)
1703 {
1704         enum module_ext_state s;
1705         verbose(VERB_ALGO, "mesh_run: start");
1706         while(mstate) {
1707                 /* run the module */
1708                 fptr_ok(fptr_whitelist_mod_operate(
1709                         mesh->mods.mod[mstate->s.curmod]->operate));
1710                 (*mesh->mods.mod[mstate->s.curmod]->operate)
1711                         (&mstate->s, ev, mstate->s.curmod, e);
1712
1713                 /* examine results */
1714                 mstate->s.reply = NULL;
1715                 regional_free_all(mstate->s.env->scratch);
1716                 s = mstate->s.ext_state[mstate->s.curmod];
1717                 verbose(VERB_ALGO, "mesh_run: %s module exit state is %s",
1718                         mesh->mods.mod[mstate->s.curmod]->name, strextstate(s));
1719                 e = NULL;
1720                 if(mesh_continue(mesh, mstate, s, &ev))
1721                         continue;
1722
1723                 /* run more modules */
1724                 ev = module_event_pass;
1725                 if(mesh->run.count > 0) {
1726                         /* pop random element off the runnable tree */
1727                         mstate = (struct mesh_state*)mesh->run.root->key;
1728                         (void)rbtree_delete(&mesh->run, mstate);
1729                 } else mstate = NULL;
1730         }
1731         if(verbosity >= VERB_ALGO) {
1732                 mesh_stats(mesh, "mesh_run: end");
1733                 mesh_log_list(mesh);
1734         }
1735 }
1736
1737 void
1738 mesh_log_list(struct mesh_area* mesh)
1739 {
1740         char buf[30];
1741         struct mesh_state* m;
1742         int num = 0;
1743         RBTREE_FOR(m, struct mesh_state*, &mesh->all) {
1744                 snprintf(buf, sizeof(buf), "%d%s%s%s%s%s%s mod%d %s%s",
1745                         num++, (m->s.is_priming)?"p":"",  /* prime */
1746                         (m->s.is_valrec)?"v":"",  /* prime */
1747                         (m->s.query_flags&BIT_RD)?"RD":"",
1748                         (m->s.query_flags&BIT_CD)?"CD":"",
1749                         (m->super_set.count==0)?"d":"", /* detached */
1750                         (m->sub_set.count!=0)?"c":"",  /* children */
1751                         m->s.curmod, (m->reply_list)?"rep":"", /*hasreply*/
1752                         (m->cb_list)?"cb":"" /* callbacks */
1753                         );
1754                 log_query_info(VERB_ALGO, buf, &m->s.qinfo);
1755         }
1756 }
1757
1758 void
1759 mesh_stats(struct mesh_area* mesh, const char* str)
1760 {
1761         verbose(VERB_DETAIL, "%s %u recursion states (%u with reply, "
1762                 "%u detached), %u waiting replies, %u recursion replies "
1763                 "sent, %d replies dropped, %d states jostled out",
1764                 str, (unsigned)mesh->all.count,
1765                 (unsigned)mesh->num_reply_states,
1766                 (unsigned)mesh->num_detached_states,
1767                 (unsigned)mesh->num_reply_addrs,
1768                 (unsigned)mesh->replies_sent,
1769                 (unsigned)mesh->stats_dropped,
1770                 (unsigned)mesh->stats_jostled);
1771         if(mesh->replies_sent > 0) {
1772                 struct timeval avg;
1773                 timeval_divide(&avg, &mesh->replies_sum_wait,
1774                         mesh->replies_sent);
1775                 log_info("average recursion processing time "
1776                         ARG_LL "d.%6.6d sec",
1777                         (long long)avg.tv_sec, (int)avg.tv_usec);
1778                 log_info("histogram of recursion processing times");
1779                 timehist_log(mesh->histogram, "recursions");
1780         }
1781 }
1782
1783 void
1784 mesh_stats_clear(struct mesh_area* mesh)
1785 {
1786         if(!mesh)
1787                 return;
1788         mesh->replies_sent = 0;
1789         mesh->replies_sum_wait.tv_sec = 0;
1790         mesh->replies_sum_wait.tv_usec = 0;
1791         mesh->stats_jostled = 0;
1792         mesh->stats_dropped = 0;
1793         timehist_clear(mesh->histogram);
1794         mesh->ans_secure = 0;
1795         mesh->ans_bogus = 0;
1796         mesh->ans_expired = 0;
1797         memset(&mesh->ans_rcode[0], 0, sizeof(size_t)*UB_STATS_RCODE_NUM);
1798         memset(&mesh->rpz_action[0], 0, sizeof(size_t)*UB_STATS_RPZ_ACTION_NUM);
1799         mesh->ans_nodata = 0;
1800 }
1801
1802 size_t
1803 mesh_get_mem(struct mesh_area* mesh)
1804 {
1805         struct mesh_state* m;
1806         size_t s = sizeof(*mesh) + sizeof(struct timehist) +
1807                 sizeof(struct th_buck)*mesh->histogram->num +
1808                 sizeof(sldns_buffer) + sldns_buffer_capacity(mesh->qbuf_bak);
1809         RBTREE_FOR(m, struct mesh_state*, &mesh->all) {
1810                 /* all, including m itself allocated in qstate region */
1811                 s += regional_get_mem(m->s.region);
1812         }
1813         return s;
1814 }
1815
1816 int
1817 mesh_detect_cycle(struct module_qstate* qstate, struct query_info* qinfo,
1818         uint16_t flags, int prime, int valrec)
1819 {
1820         struct mesh_area* mesh = qstate->env->mesh;
1821         struct mesh_state* dep_m = NULL;
1822         dep_m = mesh_area_find(mesh, NULL, qinfo, flags, prime, valrec);
1823         return mesh_detect_cycle_found(qstate, dep_m);
1824 }
1825
1826 void mesh_list_insert(struct mesh_state* m, struct mesh_state** fp,
1827         struct mesh_state** lp)
1828 {
1829         /* insert as last element */
1830         m->prev = *lp;
1831         m->next = NULL;
1832         if(*lp)
1833                 (*lp)->next = m;
1834         else    *fp = m;
1835         *lp = m;
1836 }
1837
1838 void mesh_list_remove(struct mesh_state* m, struct mesh_state** fp,
1839         struct mesh_state** lp)
1840 {
1841         if(m->next)
1842                 m->next->prev = m->prev;
1843         else    *lp = m->prev;
1844         if(m->prev)
1845                 m->prev->next = m->next;
1846         else    *fp = m->next;
1847 }
1848
1849 void mesh_state_remove_reply(struct mesh_area* mesh, struct mesh_state* m,
1850         struct comm_point* cp)
1851 {
1852         struct mesh_reply* n, *prev = NULL;
1853         n = m->reply_list;
1854         /* when in mesh_cleanup, it sets the reply_list to NULL, so that
1855          * there is no accounting twice */
1856         if(!n) return; /* nothing to remove, also no accounting needed */
1857         while(n) {
1858                 if(n->query_reply.c == cp) {
1859                         /* unlink it */
1860                         if(prev) prev->next = n->next;
1861                         else m->reply_list = n->next;
1862                         /* delete it, but allocated in m region */
1863                         log_assert(mesh->num_reply_addrs > 0);
1864                         mesh->num_reply_addrs--;
1865
1866                         /* prev = prev; */
1867                         n = n->next;
1868                         continue;
1869                 }
1870                 prev = n;
1871                 n = n->next;
1872         }
1873         /* it was not detached (because it had a reply list), could be now */
1874         if(!m->reply_list && !m->cb_list
1875                 && m->super_set.count == 0) {
1876                 mesh->num_detached_states++;
1877         }
1878         /* if not replies any more in mstate, it is no longer a reply_state */
1879         if(!m->reply_list && !m->cb_list) {
1880                 log_assert(mesh->num_reply_states > 0);
1881                 mesh->num_reply_states--;
1882         }
1883 }
1884
1885
1886 static int
1887 apply_respip_action(struct module_qstate* qstate,
1888         const struct query_info* qinfo, struct respip_client_info* cinfo,
1889         struct respip_action_info* actinfo, struct reply_info* rep,
1890         struct ub_packed_rrset_key** alias_rrset,
1891         struct reply_info** encode_repp, struct auth_zones* az)
1892 {
1893         if(qinfo->qtype != LDNS_RR_TYPE_A &&
1894                 qinfo->qtype != LDNS_RR_TYPE_AAAA &&
1895                 qinfo->qtype != LDNS_RR_TYPE_ANY)
1896                 return 1;
1897
1898         if(!respip_rewrite_reply(qinfo, cinfo, rep, encode_repp, actinfo,
1899                 alias_rrset, 0, qstate->region, az))
1900                 return 0;
1901
1902         /* xxx_deny actions mean dropping the reply, unless the original reply
1903          * was redirected to response-ip data. */
1904         if((actinfo->action == respip_deny ||
1905                 actinfo->action == respip_inform_deny) &&
1906                 *encode_repp == rep)
1907                 *encode_repp = NULL;
1908
1909         return 1;
1910 }
1911
1912 void
1913 mesh_serve_expired_callback(void* arg)
1914 {
1915         struct mesh_state* mstate = (struct mesh_state*) arg;
1916         struct module_qstate* qstate = &mstate->s;
1917         struct mesh_reply* r;
1918         struct mesh_area* mesh = qstate->env->mesh;
1919         struct dns_msg* msg;
1920         struct mesh_cb* c;
1921         struct mesh_reply* prev = NULL;
1922         struct sldns_buffer* prev_buffer = NULL;
1923         struct sldns_buffer* r_buffer = NULL;
1924         struct reply_info* partial_rep = NULL;
1925         struct ub_packed_rrset_key* alias_rrset = NULL;
1926         struct reply_info* encode_rep = NULL;
1927         struct respip_action_info actinfo;
1928         struct query_info* lookup_qinfo = &qstate->qinfo;
1929         struct query_info qinfo_tmp;
1930         struct timeval tv = {0, 0};
1931         int must_validate = (!(qstate->query_flags&BIT_CD)
1932                 || qstate->env->cfg->ignore_cd) && qstate->env->need_to_validate;
1933         if(!qstate->serve_expired_data) return;
1934         verbose(VERB_ALGO, "Serve expired: Trying to reply with expired data");
1935         comm_timer_delete(qstate->serve_expired_data->timer);
1936         qstate->serve_expired_data->timer = NULL;
1937         /* If is_drop or no_cache_lookup (modules that handle their own cache e.g.,
1938          * subnetmod) ignore stale data from the main cache. */
1939         if(qstate->no_cache_lookup || qstate->is_drop) {
1940                 verbose(VERB_ALGO,
1941                         "Serve expired: Not allowed to look into cache for stale");
1942                 return;
1943         }
1944         /* The following while is used instead of the `goto lookup_cache`
1945          * like in the worker. */
1946         while(1) {
1947                 fptr_ok(fptr_whitelist_serve_expired_lookup(
1948                         qstate->serve_expired_data->get_cached_answer));
1949                 msg = (*qstate->serve_expired_data->get_cached_answer)(qstate,
1950                         lookup_qinfo);
1951                 if(!msg)
1952                         return;
1953                 /* Reset these in case we pass a second time from here. */
1954                 encode_rep = msg->rep;
1955                 memset(&actinfo, 0, sizeof(actinfo));
1956                 actinfo.action = respip_none;
1957                 alias_rrset = NULL;
1958                 if((mesh->use_response_ip || mesh->use_rpz) &&
1959                         !partial_rep && !apply_respip_action(qstate, &qstate->qinfo,
1960                         qstate->client_info, &actinfo, msg->rep, &alias_rrset, &encode_rep,
1961                         qstate->env->auth_zones)) {
1962                         return;
1963                 } else if(partial_rep &&
1964                         !respip_merge_cname(partial_rep, &qstate->qinfo, msg->rep,
1965                         qstate->client_info, must_validate, &encode_rep, qstate->region,
1966                         qstate->env->auth_zones)) {
1967                         return;
1968                 }
1969                 if(!encode_rep || alias_rrset) {
1970                         if(!encode_rep) {
1971                                 /* Needs drop */
1972                                 return;
1973                         } else {
1974                                 /* A partial CNAME chain is found. */
1975                                 partial_rep = encode_rep;
1976                         }
1977                 }
1978                 /* We've found a partial reply ending with an
1979                 * alias.  Replace the lookup qinfo for the
1980                 * alias target and lookup the cache again to
1981                 * (possibly) complete the reply.  As we're
1982                 * passing the "base" reply, there will be no
1983                 * more alias chasing. */
1984                 if(partial_rep) {
1985                         memset(&qinfo_tmp, 0, sizeof(qinfo_tmp));
1986                         get_cname_target(alias_rrset, &qinfo_tmp.qname,
1987                                 &qinfo_tmp.qname_len);
1988                         if(!qinfo_tmp.qname) {
1989                                 log_err("Serve expired: unexpected: invalid answer alias");
1990                                 return;
1991                         }
1992                         qinfo_tmp.qtype = qstate->qinfo.qtype;
1993                         qinfo_tmp.qclass = qstate->qinfo.qclass;
1994                         lookup_qinfo = &qinfo_tmp;
1995                         continue;
1996                 }
1997                 break;
1998         }
1999
2000         if(verbosity >= VERB_ALGO)
2001                 log_dns_msg("Serve expired lookup", &qstate->qinfo, msg->rep);
2002
2003         for(r = mstate->reply_list; r; r = r->next) {
2004                 tv = r->start_time;
2005
2006                 /* If address info is returned, it means the action should be an
2007                 * 'inform' variant and the information should be logged. */
2008                 if(actinfo.addrinfo) {
2009                         respip_inform_print(&actinfo, r->qname,
2010                                 qstate->qinfo.qtype, qstate->qinfo.qclass,
2011                                 r->local_alias, &r->query_reply);
2012
2013                         if(qstate->env->cfg->stat_extended && actinfo.rpz_used) {
2014                                 if(actinfo.rpz_disabled)
2015                                         qstate->env->mesh->rpz_action[RPZ_DISABLED_ACTION]++;
2016                                 if(actinfo.rpz_cname_override)
2017                                         qstate->env->mesh->rpz_action[RPZ_CNAME_OVERRIDE_ACTION]++;
2018                                 else
2019                                         qstate->env->mesh->rpz_action[
2020                                                 respip_action_to_rpz_action(actinfo.action)]++;
2021                         }
2022                 }
2023
2024                 r_buffer = r->query_reply.c->buffer;
2025                 if(r->query_reply.c->tcp_req_info)
2026                         r_buffer = r->query_reply.c->tcp_req_info->spool_buffer;
2027                 mesh_send_reply(mstate, LDNS_RCODE_NOERROR, msg->rep,
2028                         r, r_buffer, prev, prev_buffer);
2029                 if(r->query_reply.c->tcp_req_info)
2030                         tcp_req_info_remove_mesh_state(r->query_reply.c->tcp_req_info, mstate);
2031                 prev = r;
2032                 prev_buffer = r_buffer;
2033
2034                 /* Account for each reply sent. */
2035                 mesh->ans_expired++;
2036
2037         }
2038         if(mstate->reply_list) {
2039                 mstate->reply_list = NULL;
2040                 if(!mstate->reply_list && !mstate->cb_list) {
2041                         log_assert(mesh->num_reply_states > 0);
2042                         mesh->num_reply_states--;
2043                         if(mstate->super_set.count == 0) {
2044                                 mesh->num_detached_states++;
2045                         }
2046                 }
2047         }
2048         while((c = mstate->cb_list) != NULL) {
2049                 /* take this cb off the list; so that the list can be
2050                  * changed, eg. by adds from the callback routine */
2051                 if(!mstate->reply_list && mstate->cb_list && !c->next) {
2052                         /* was a reply state, not anymore */
2053                         log_assert(qstate->env->mesh->num_reply_states > 0);
2054                         qstate->env->mesh->num_reply_states--;
2055                 }
2056                 mstate->cb_list = c->next;
2057                 if(!mstate->reply_list && !mstate->cb_list &&
2058                         mstate->super_set.count == 0)
2059                         qstate->env->mesh->num_detached_states++;
2060                 mesh_do_callback(mstate, LDNS_RCODE_NOERROR, msg->rep, c, &tv);
2061         }
2062 }