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 LIMITED
  25  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  26  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE
  27  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  28  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  29  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  30  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  31  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  32  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  33  * 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 <ldns/wire2host.h>
  47 #include "services/mesh.h"
  48 #include "services/outbound_list.h"
  49 #include "services/cache/dns.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
  60 /** subtract timers and the values do not overflow or become negative */
  61 static void
  62 timeval_subtract(struct timeval* d, const struct timeval* end, const struct timeval* start)
  63 {
  64 #ifndef S_SPLINT_S
  65         time_t end_usec = end->tv_usec;
  66         d->tv_sec = end->tv_sec - start->tv_sec;
  67         if(end_usec < start->tv_usec) {
  68                 end_usec += 1000000;
  69                 d->tv_sec--;
  70         }
  71         d->tv_usec = end_usec - start->tv_usec;
  72 #endif
  73 }
  74
  75 /** add timers and the values do not overflow or become negative */
  76 static void
  77 timeval_add(struct timeval* d, const struct timeval* add)
  78 {
  79 #ifndef S_SPLINT_S
  80         d->tv_sec += add->tv_sec;
  81         d->tv_usec += add->tv_usec;
  82         if(d->tv_usec > 1000000 ) {
  83                 d->tv_usec -= 1000000;
  84                 d->tv_sec++;
  85         }
  86 #endif
  87 }
  88
  89 /** divide sum of timers to get average */
  90 static void
  91 timeval_divide(struct timeval* avg, const struct timeval* sum, size_t d)
  92 {
  93 #ifndef S_SPLINT_S
  94         size_t leftover;
  95         if(d == 0) {
  96                 avg->tv_sec = 0;
  97                 avg->tv_usec = 0;
  98                 return;
  99         }
 100         avg->tv_sec = sum->tv_sec / d;
 101         avg->tv_usec = sum->tv_usec / d;
 102         /* handle fraction from seconds divide */
 103         leftover = sum->tv_sec - avg->tv_sec*d;
 104         avg->tv_usec += (leftover*1000000)/d;
 105 #endif
 106 }
 107
 108 /** histogram compare of time values */
 109 static int
 110 timeval_smaller(const struct timeval* x, const struct timeval* y)
 111 {
 112 #ifndef S_SPLINT_S
 113         if(x->tv_sec < y->tv_sec)
 114                 return 1;
 115         else if(x->tv_sec == y->tv_sec) {
 116                 if(x->tv_usec <= y->tv_usec)
 117                         return 1;
 118                 else    return 0;
 119         }
 120         else    return 0;
 121 #endif
 122 }
 123
 124 int
 125 mesh_state_compare(const void* ap, const void* bp)
 126 {
 127         struct mesh_state* a = (struct mesh_state*)ap;
 128         struct mesh_state* b = (struct mesh_state*)bp;
 129
 130         if(a->s.is_priming && !b->s.is_priming)
 131                 return -1;
 132         if(!a->s.is_priming && b->s.is_priming)
 133                 return 1;
 134
 135         if((a->s.query_flags&BIT_RD) && !(b->s.query_flags&BIT_RD))
 136                 return -1;
 137         if(!(a->s.query_flags&BIT_RD) && (b->s.query_flags&BIT_RD))
 138                 return 1;
 139
 140         if((a->s.query_flags&BIT_CD) && !(b->s.query_flags&BIT_CD))
 141                 return -1;
 142         if(!(a->s.query_flags&BIT_CD) && (b->s.query_flags&BIT_CD))
 143                 return 1;
 144
 145         return query_info_compare(&a->s.qinfo, &b->s.qinfo);
 146 }
 147
 148 int
 149 mesh_state_ref_compare(const void* ap, const void* bp)
 150 {
 151         struct mesh_state_ref* a = (struct mesh_state_ref*)ap;
 152         struct mesh_state_ref* b = (struct mesh_state_ref*)bp;
 153         return mesh_state_compare(a->s, b->s);
 154 }
 155
 156 struct mesh_area*
 157 mesh_create(struct module_stack* stack, struct module_env* env)
 158 {
 159         struct mesh_area* mesh = calloc(1, sizeof(struct mesh_area));
 160         if(!mesh) {
 161                 log_err("mesh area alloc: out of memory");
 162                 return NULL;
 163         }
 164         mesh->histogram = timehist_setup();
 165         mesh->qbuf_bak = ldns_buffer_new(env->cfg->msg_buffer_size);
 166         if(!mesh->histogram || !mesh->qbuf_bak) {
 167                 free(mesh);
 168                 log_err("mesh area alloc: out of memory");
 169                 return NULL;
 170         }
 171         mesh->mods = *stack;
 172         mesh->env = env;
 173         rbtree_init(&mesh->run, &mesh_state_compare);
 174         rbtree_init(&mesh->all, &mesh_state_compare);
 175         mesh->num_reply_addrs = 0;
 176         mesh->num_reply_states = 0;
 177         mesh->num_detached_states = 0;
 178         mesh->num_forever_states = 0;
 179         mesh->stats_jostled = 0;
 180         mesh->stats_dropped = 0;
 181         mesh->max_reply_states = env->cfg->num_queries_per_thread;
 182         mesh->max_forever_states = (mesh->max_reply_states+1)/2;
 183 #ifndef S_SPLINT_S
 184         mesh->jostle_max.tv_sec = (time_t)(env->cfg->jostle_time / 1000);
 185         mesh->jostle_max.tv_usec = (time_t)((env->cfg->jostle_time % 1000)
 186                 *1000);
 187 #endif
 188         return mesh;
 189 }
 190
 191 /** help mesh delete delete mesh states */
 192 static void
 193 mesh_delete_helper(rbnode_t* n)
 194 {
 195         struct mesh_state* mstate = (struct mesh_state*)n->key;
 196         /* perform a full delete, not only 'cleanup' routine,
 197          * because other callbacks expect a clean state in the mesh.
 198          * For 're-entrant' calls */
 199         mesh_state_delete(&mstate->s);
 200         /* but because these delete the items from the tree, postorder
 201          * traversal and rbtree rebalancing do not work together */
 202 }
 203
 204 void
 205 mesh_delete(struct mesh_area* mesh)
 206 {
 207         if(!mesh)
 208                 return;
 209         /* free all query states */
 210         while(mesh->all.count)
 211                 mesh_delete_helper(mesh->all.root);
 212         timehist_delete(mesh->histogram);
 213         ldns_buffer_free(mesh->qbuf_bak);
 214         free(mesh);
 215 }
 216
 217 void
 218 mesh_delete_all(struct mesh_area* mesh)
 219 {
 220         /* free all query states */
 221         while(mesh->all.count)
 222                 mesh_delete_helper(mesh->all.root);
 223         mesh->stats_dropped += mesh->num_reply_addrs;
 224         /* clear mesh area references */
 225         rbtree_init(&mesh->run, &mesh_state_compare);
 226         rbtree_init(&mesh->all, &mesh_state_compare);
 227         mesh->num_reply_addrs = 0;
 228         mesh->num_reply_states = 0;
 229         mesh->num_detached_states = 0;
 230         mesh->num_forever_states = 0;
 231         mesh->forever_first = NULL;
 232         mesh->forever_last = NULL;
 233         mesh->jostle_first = NULL;
 234         mesh->jostle_last = NULL;
 235 }
 236
 237 int mesh_make_new_space(struct mesh_area* mesh, ldns_buffer* qbuf)
 238 {
 239         struct mesh_state* m = mesh->jostle_first;
 240         /* free space is available */
 241         if(mesh->num_reply_states < mesh->max_reply_states)
 242                 return 1;
 243         /* try to kick out a jostle-list item */
 244         if(m && m->reply_list && m->list_select == mesh_jostle_list) {
 245                 /* how old is it? */
 246                 struct timeval age;
 247                 timeval_subtract(&age, mesh->env->now_tv,
 248                         &m->reply_list->start_time);
 249                 if(timeval_smaller(&mesh->jostle_max, &age)) {
 250                         /* its a goner */
 251                         log_nametypeclass(VERB_ALGO, "query jostled out to "
 252                                 "make space for a new one",
 253                                 m->s.qinfo.qname, m->s.qinfo.qtype,
 254                                 m->s.qinfo.qclass);
 255                         /* backup the query */
 256                         if(qbuf) ldns_buffer_copy(mesh->qbuf_bak, qbuf);
 257                         /* notify supers */
 258                         if(m->super_set.count > 0) {
 259                                 verbose(VERB_ALGO, "notify supers of failure");
 260                                 m->s.return_msg = NULL;
 261                                 m->s.return_rcode = LDNS_RCODE_SERVFAIL;
 262                                 mesh_walk_supers(mesh, m);
 263                         }
 264                         mesh->stats_jostled ++;
 265                         mesh_state_delete(&m->s);
 266                         /* restore the query - note that the qinfo ptr to
 267                          * the querybuffer is then correct again. */
 268                         if(qbuf) ldns_buffer_copy(qbuf, mesh->qbuf_bak);
 269                         return 1;
 270                 }
 271         }
 272         /* no space for new item */
 273         return 0;
 274 }
 275
 276 void mesh_new_client(struct mesh_area* mesh, struct query_info* qinfo,
 277         uint16_t qflags, struct edns_data* edns, struct comm_reply* rep,
 278         uint16_t qid)
 279 {
 280         /* do not use CD flag from user for mesh state, we want the CD-query
 281          * to receive validation anyway, to protect out cache contents and
 282          * avoid bad-data in this cache that a downstream validator cannot
 283          * remove from this cache */
 284         struct mesh_state* s = mesh_area_find(mesh, qinfo, qflags&BIT_RD, 0);
 285         int was_detached = 0;
 286         int was_noreply = 0;
 287         int added = 0;
 288         /* does this create a new reply state? */
 289         if(!s || s->list_select == mesh_no_list) {
 290                 if(!mesh_make_new_space(mesh, rep->c->buffer)) {
 291                         verbose(VERB_ALGO, "Too many queries. dropping "
 292                                 "incoming query.");
 293                         comm_point_drop_reply(rep);
 294                         mesh->stats_dropped ++;
 295                         return;
 296                 }
 297                 /* for this new reply state, the reply address is free,
 298                  * so the limit of reply addresses does not stop reply states*/
 299         } else {
 300                 /* protect our memory usage from storing reply addresses */
 301                 if(mesh->num_reply_addrs > mesh->max_reply_states*16) {
 302                         verbose(VERB_ALGO, "Too many requests queued. "
 303                                 "dropping incoming query.");
 304                         mesh->stats_dropped++;
 305                         comm_point_drop_reply(rep);
 306                         return;
 307                 }
 308         }
 309         /* see if it already exists, if not, create one */
 310         if(!s) {
 311 #ifdef UNBOUND_DEBUG
 312                 struct rbnode_t* n;
 313 #endif
 314                 s = mesh_state_create(mesh->env, qinfo, qflags&BIT_RD, 0);
 315                 if(!s) {
 316                         log_err("mesh_state_create: out of memory; SERVFAIL");
 317                         error_encode(rep->c->buffer, LDNS_RCODE_SERVFAIL,
 318                                 qinfo, qid, qflags, edns);
 319                         comm_point_send_reply(rep);
 320                         return;
 321                 }
 322 #ifdef UNBOUND_DEBUG
 323                 n =
 324 #endif
 325                 rbtree_insert(&mesh->all, &s->node);
 326                 log_assert(n != NULL);
 327                 /* set detached (it is now) */
 328                 mesh->num_detached_states++;
 329                 added = 1;
 330         }
 331         if(!s->reply_list && !s->cb_list && s->super_set.count == 0)
 332                 was_detached = 1;
 333         if(!s->reply_list && !s->cb_list)
 334                 was_noreply = 1;
 335         /* add reply to s */
 336         if(!mesh_state_add_reply(s, edns, rep, qid, qflags, qinfo->qname)) {
 337                         log_err("mesh_new_client: out of memory; SERVFAIL");
 338                         error_encode(rep->c->buffer, LDNS_RCODE_SERVFAIL,
 339                                 qinfo, qid, qflags, edns);
 340                         comm_point_send_reply(rep);
 341                         if(added)
 342                                 mesh_state_delete(&s->s);
 343                         return;
 344         }
 345         /* update statistics */
 346         if(was_detached) {
 347                 log_assert(mesh->num_detached_states > 0);
 348                 mesh->num_detached_states--;
 349         }
 350         if(was_noreply) {
 351                 mesh->num_reply_states ++;
 352         }
 353         mesh->num_reply_addrs++;
 354         if(s->list_select == mesh_no_list) {
 355                 /* move to either the forever or the jostle_list */
 356                 if(mesh->num_forever_states < mesh->max_forever_states) {
 357                         mesh->num_forever_states ++;
 358                         mesh_list_insert(s, &mesh->forever_first,
 359                                 &mesh->forever_last);
 360                         s->list_select = mesh_forever_list;
 361                 } else {
 362                         mesh_list_insert(s, &mesh->jostle_first,
 363                                 &mesh->jostle_last);
 364                         s->list_select = mesh_jostle_list;
 365                 }
 366         }
 367         if(added)
 368                 mesh_run(mesh, s, module_event_new, NULL);
 369 }
 370
 371 int
 372 mesh_new_callback(struct mesh_area* mesh, struct query_info* qinfo,
 373         uint16_t qflags, struct edns_data* edns, ldns_buffer* buf,
 374         uint16_t qid, mesh_cb_func_t cb, void* cb_arg)
 375 {
 376         struct mesh_state* s = mesh_area_find(mesh, qinfo, qflags&BIT_RD, 0);
 377         int was_detached = 0;
 378         int was_noreply = 0;
 379         int added = 0;
 380         /* there are no limits on the number of callbacks */
 381
 382         /* see if it already exists, if not, create one */
 383         if(!s) {
 384 #ifdef UNBOUND_DEBUG
 385                 struct rbnode_t* n;
 386 #endif
 387                 s = mesh_state_create(mesh->env, qinfo, qflags&BIT_RD, 0);
 388                 if(!s) {
 389                         return 0;
 390                 }
 391 #ifdef UNBOUND_DEBUG
 392                 n =
 393 #endif
 394                 rbtree_insert(&mesh->all, &s->node);
 395                 log_assert(n != NULL);
 396                 /* set detached (it is now) */
 397                 mesh->num_detached_states++;
 398                 added = 1;
 399         }
 400         if(!s->reply_list && !s->cb_list && s->super_set.count == 0)
 401                 was_detached = 1;
 402         if(!s->reply_list && !s->cb_list)
 403                 was_noreply = 1;
 404         /* add reply to s */
 405         if(!mesh_state_add_cb(s, edns, buf, cb, cb_arg, qid, qflags)) {
 406                         if(added)
 407                                 mesh_state_delete(&s->s);
 408                         return 0;
 409         }
 410         /* update statistics */
 411         if(was_detached) {
 412                 log_assert(mesh->num_detached_states > 0);
 413                 mesh->num_detached_states--;
 414         }
 415         if(was_noreply) {
 416                 mesh->num_reply_states ++;
 417         }
 418         mesh->num_reply_addrs++;
 419         if(added)
 420                 mesh_run(mesh, s, module_event_new, NULL);
 421         return 1;
 422 }
 423
 424 void mesh_new_prefetch(struct mesh_area* mesh, struct query_info* qinfo,
 425         uint16_t qflags, uint32_t leeway)
 426 {
 427         struct mesh_state* s = mesh_area_find(mesh, qinfo, qflags&BIT_RD, 0);
 428 #ifdef UNBOUND_DEBUG
 429         struct rbnode_t* n;
 430 #endif
 431         /* already exists, and for a different purpose perhaps.
 432          * if mesh_no_list, keep it that way. */
 433         if(s) {
 434                 /* make it ignore the cache from now on */
 435                 if(!s->s.blacklist)
 436                         sock_list_insert(&s->s.blacklist, NULL, 0, s->s.region);
 437                 if(s->s.prefetch_leeway < leeway)
 438                         s->s.prefetch_leeway = leeway;
 439                 return;
 440         }
 441         if(!mesh_make_new_space(mesh, NULL)) {
 442                 verbose(VERB_ALGO, "Too many queries. dropped prefetch.");
 443                 mesh->stats_dropped ++;
 444                 return;
 445         }
 446         s = mesh_state_create(mesh->env, qinfo, qflags&BIT_RD, 0);
 447         if(!s) {
 448                 log_err("prefetch mesh_state_create: out of memory");
 449                 return;
 450         }
 451 #ifdef UNBOUND_DEBUG
 452         n =
 453 #endif
 454         rbtree_insert(&mesh->all, &s->node);
 455         log_assert(n != NULL);
 456         /* set detached (it is now) */
 457         mesh->num_detached_states++;
 458         /* make it ignore the cache */
 459         sock_list_insert(&s->s.blacklist, NULL, 0, s->s.region);
 460         s->s.prefetch_leeway = leeway;
 461
 462         if(s->list_select == mesh_no_list) {
 463                 /* move to either the forever or the jostle_list */
 464                 if(mesh->num_forever_states < mesh->max_forever_states) {
 465                         mesh->num_forever_states ++;
 466                         mesh_list_insert(s, &mesh->forever_first,
 467                                 &mesh->forever_last);
 468                         s->list_select = mesh_forever_list;
 469                 } else {
 470                         mesh_list_insert(s, &mesh->jostle_first,
 471                                 &mesh->jostle_last);
 472                         s->list_select = mesh_jostle_list;
 473                 }
 474         }
 475         mesh_run(mesh, s, module_event_new, NULL);
 476 }
 477
 478 void mesh_report_reply(struct mesh_area* mesh, struct outbound_entry* e,
 479         struct comm_reply* reply, int what)
 480 {
 481         enum module_ev event = module_event_reply;
 482         e->qstate->reply = reply;
 483         if(what != NETEVENT_NOERROR) {
 484                 event = module_event_noreply;
 485                 if(what == NETEVENT_CAPSFAIL)
 486                         event = module_event_capsfail;
 487         }
 488         mesh_run(mesh, e->qstate->mesh_info, event, e);
 489 }
 490
 491 struct mesh_state*
 492 mesh_state_create(struct module_env* env, struct query_info* qinfo,
 493         uint16_t qflags, int prime)
 494 {
 495         struct regional* region = alloc_reg_obtain(env->alloc);
 496         struct mesh_state* mstate;
 497         int i;
 498         if(!region)
 499                 return NULL;
 500         mstate = (struct mesh_state*)regional_alloc(region,
 501                 sizeof(struct mesh_state));
 502         if(!mstate) {
 503                 alloc_reg_release(env->alloc, region);
 504                 return NULL;
 505         }
 506         memset(mstate, 0, sizeof(*mstate));
 507         mstate->node = *RBTREE_NULL;
 508         mstate->run_node = *RBTREE_NULL;
 509         mstate->node.key = mstate;
 510         mstate->run_node.key = mstate;
 511         mstate->reply_list = NULL;
 512         mstate->list_select = mesh_no_list;
 513         mstate->replies_sent = 0;
 514         rbtree_init(&mstate->super_set, &mesh_state_ref_compare);
 515         rbtree_init(&mstate->sub_set, &mesh_state_ref_compare);
 516         mstate->num_activated = 0;
 517         /* init module qstate */
 518         mstate->s.qinfo.qtype = qinfo->qtype;
 519         mstate->s.qinfo.qclass = qinfo->qclass;
 520         mstate->s.qinfo.qname_len = qinfo->qname_len;
 521         mstate->s.qinfo.qname = regional_alloc_init(region, qinfo->qname,
 522                 qinfo->qname_len);
 523         if(!mstate->s.qinfo.qname) {
 524                 alloc_reg_release(env->alloc, region);
 525                 return NULL;
 526         }
 527         /* remove all weird bits from qflags */
 528         mstate->s.query_flags = (qflags & (BIT_RD|BIT_CD));
 529         mstate->s.is_priming = prime;
 530         mstate->s.reply = NULL;
 531         mstate->s.region = region;
 532         mstate->s.curmod = 0;
 533         mstate->s.return_msg = 0;
 534         mstate->s.return_rcode = LDNS_RCODE_NOERROR;
 535         mstate->s.env = env;
 536         mstate->s.mesh_info = mstate;
 537         mstate->s.prefetch_leeway = 0;
 538         /* init modules */
 539         for(i=0; i<env->mesh->mods.num; i++) {
 540                 mstate->s.minfo[i] = NULL;
 541                 mstate->s.ext_state[i] = module_state_initial;
 542         }
 543         return mstate;
 544 }
 545
 546 void
 547 mesh_state_cleanup(struct mesh_state* mstate)
 548 {
 549         struct mesh_area* mesh;
 550         int i;
 551         if(!mstate)
 552                 return;
 553         mesh = mstate->s.env->mesh;
 554         /* drop unsent replies */
 555         if(!mstate->replies_sent) {
 556                 struct mesh_reply* rep;
 557                 struct mesh_cb* cb;
 558                 for(rep=mstate->reply_list; rep; rep=rep->next) {
 559                         comm_point_drop_reply(&rep->query_reply);
 560                         mesh->num_reply_addrs--;
 561                 }
 562                 for(cb=mstate->cb_list; cb; cb=cb->next) {
 563                         fptr_ok(fptr_whitelist_mesh_cb(cb->cb));
 564                         (*cb->cb)(cb->cb_arg, LDNS_RCODE_SERVFAIL, NULL,
 565                                 sec_status_unchecked, NULL);
 566                         mesh->num_reply_addrs--;
 567                 }
 568         }
 569
 570         /* de-init modules */
 571         for(i=0; i<mesh->mods.num; i++) {
 572                 fptr_ok(fptr_whitelist_mod_clear(mesh->mods.mod[i]->clear));
 573                 (*mesh->mods.mod[i]->clear)(&mstate->s, i);
 574                 mstate->s.minfo[i] = NULL;
 575                 mstate->s.ext_state[i] = module_finished;
 576         }
 577         alloc_reg_release(mstate->s.env->alloc, mstate->s.region);
 578 }
 579
 580 void
 581 mesh_state_delete(struct module_qstate* qstate)
 582 {
 583         struct mesh_area* mesh;
 584         struct mesh_state_ref* super, ref;
 585         struct mesh_state* mstate;
 586         if(!qstate)
 587                 return;
 588         mstate = qstate->mesh_info;
 589         mesh = mstate->s.env->mesh;
 590         mesh_detach_subs(&mstate->s);
 591         if(mstate->list_select == mesh_forever_list) {
 592                 mesh->num_forever_states --;
 593                 mesh_list_remove(mstate, &mesh->forever_first,
 594                         &mesh->forever_last);
 595         } else if(mstate->list_select == mesh_jostle_list) {
 596                 mesh_list_remove(mstate, &mesh->jostle_first,
 597                         &mesh->jostle_last);
 598         }
 599         if(!mstate->reply_list && !mstate->cb_list
 600                 && mstate->super_set.count == 0) {
 601                 log_assert(mesh->num_detached_states > 0);
 602                 mesh->num_detached_states--;
 603         }
 604         if(mstate->reply_list || mstate->cb_list) {
 605                 log_assert(mesh->num_reply_states > 0);
 606                 mesh->num_reply_states--;
 607         }
 608         ref.node.key = &ref;
 609         ref.s = mstate;
 610         RBTREE_FOR(super, struct mesh_state_ref*, &mstate->super_set) {
 611                 (void)rbtree_delete(&super->s->sub_set, &ref);
 612         }
 613         (void)rbtree_delete(&mesh->run, mstate);
 614         (void)rbtree_delete(&mesh->all, mstate);
 615         mesh_state_cleanup(mstate);
 616 }
 617
 618 /** helper recursive rbtree find routine */
 619 static int
 620 find_in_subsub(struct mesh_state* m, struct mesh_state* tofind, size_t *c)
 621 {
 622         struct mesh_state_ref* r;
 623         if((*c)++ > MESH_MAX_SUBSUB)
 624                 return 1;
 625         RBTREE_FOR(r, struct mesh_state_ref*, &m->sub_set) {
 626                 if(r->s == tofind || find_in_subsub(r->s, tofind, c))
 627                         return 1;
 628         }
 629         return 0;
 630 }
 631
 632 /** find cycle for already looked up mesh_state */
 633 static int
 634 mesh_detect_cycle_found(struct module_qstate* qstate, struct mesh_state* dep_m)
 635 {
 636         struct mesh_state* cyc_m = qstate->mesh_info;
 637         size_t counter = 0;
 638         if(!dep_m)
 639                 return 0;
 640         if(dep_m == cyc_m || find_in_subsub(dep_m, cyc_m, &counter)) {
 641                 if(counter > MESH_MAX_SUBSUB)
 642                         return 2;
 643                 return 1;
 644         }
 645         return 0;
 646 }
 647
 648 void mesh_detach_subs(struct module_qstate* qstate)
 649 {
 650         struct mesh_area* mesh = qstate->env->mesh;
 651         struct mesh_state_ref* ref, lookup;
 652 #ifdef UNBOUND_DEBUG
 653         struct rbnode_t* n;
 654 #endif
 655         lookup.node.key = &lookup;
 656         lookup.s = qstate->mesh_info;
 657         RBTREE_FOR(ref, struct mesh_state_ref*, &qstate->mesh_info->sub_set) {
 658 #ifdef UNBOUND_DEBUG
 659                 n =
 660 #endif
 661                 rbtree_delete(&ref->s->super_set, &lookup);
 662                 log_assert(n != NULL); /* must have been present */
 663                 if(!ref->s->reply_list && !ref->s->cb_list
 664                         && ref->s->super_set.count == 0) {
 665                         mesh->num_detached_states++;
 666                         log_assert(mesh->num_detached_states +
 667                                 mesh->num_reply_states <= mesh->all.count);
 668                 }
 669         }
 670         rbtree_init(&qstate->mesh_info->sub_set, &mesh_state_ref_compare);
 671 }
 672
 673 int mesh_attach_sub(struct module_qstate* qstate, struct query_info* qinfo,
 674         uint16_t qflags, int prime, struct module_qstate** newq)
 675 {
 676         /* find it, if not, create it */
 677         struct mesh_area* mesh = qstate->env->mesh;
 678         struct mesh_state* sub = mesh_area_find(mesh, qinfo, qflags, prime);
 679         int was_detached;
 680         if(mesh_detect_cycle_found(qstate, sub)) {
 681                 verbose(VERB_ALGO, "attach failed, cycle detected");
 682                 return 0;
 683         }
 684         if(!sub) {
 685 #ifdef UNBOUND_DEBUG
 686                 struct rbnode_t* n;
 687 #endif
 688                 /* create a new one */
 689                 sub = mesh_state_create(qstate->env, qinfo, qflags, prime);
 690                 if(!sub) {
 691                         log_err("mesh_attach_sub: out of memory");
 692                         return 0;
 693                 }
 694 #ifdef UNBOUND_DEBUG
 695                 n =
 696 #endif
 697                 rbtree_insert(&mesh->all, &sub->node);
 698                 log_assert(n != NULL);
 699                 /* set detached (it is now) */
 700                 mesh->num_detached_states++;
 701                 /* set new query state to run */
 702 #ifdef UNBOUND_DEBUG
 703                 n =
 704 #endif
 705                 rbtree_insert(&mesh->run, &sub->run_node);
 706                 log_assert(n != NULL);
 707                 *newq = &sub->s;
 708         } else
 709                 *newq = NULL;
 710         was_detached = (sub->super_set.count == 0);
 711         if(!mesh_state_attachment(qstate->mesh_info, sub))
 712                 return 0;
 713         /* if it was a duplicate  attachment, the count was not zero before */
 714         if(!sub->reply_list && !sub->cb_list && was_detached &&
 715                 sub->super_set.count == 1) {
 716                 /* it used to be detached, before this one got added */
 717                 log_assert(mesh->num_detached_states > 0);
 718                 mesh->num_detached_states--;
 719         }
 720         /* *newq will be run when inited after the current module stops */
 721         return 1;
 722 }
 723
 724 int mesh_state_attachment(struct mesh_state* super, struct mesh_state* sub)
 725 {
 726 #ifdef UNBOUND_DEBUG
 727         struct rbnode_t* n;
 728 #endif
 729         struct mesh_state_ref* subref; /* points to sub, inserted in super */
 730         struct mesh_state_ref* superref; /* points to super, inserted in sub */
 731         if( !(subref = regional_alloc(super->s.region,
 732                 sizeof(struct mesh_state_ref))) ||
 733                 !(superref = regional_alloc(sub->s.region,
 734                 sizeof(struct mesh_state_ref))) ) {
 735                 log_err("mesh_state_attachment: out of memory");
 736                 return 0;
 737         }
 738         superref->node.key = superref;
 739         superref->s = super;
 740         subref->node.key = subref;
 741         subref->s = sub;
 742         if(!rbtree_insert(&sub->super_set, &superref->node)) {
 743                 /* this should not happen, iterator and validator do not
 744                  * attach subqueries that are identical. */
 745                 /* already attached, we are done, nothing todo.
 746                  * since superref and subref already allocated in region,
 747                  * we cannot free them */
 748                 return 1;
 749         }
 750 #ifdef UNBOUND_DEBUG
 751         n =
 752 #endif
 753         rbtree_insert(&super->sub_set, &subref->node);
 754         log_assert(n != NULL); /* we checked above if statement, the reverse
 755           administration should not fail now, unless they are out of sync */
 756         return 1;
 757 }
 758
 759 /**
 760  * callback results to mesh cb entry
 761  * @param m: mesh state to send it for.
 762  * @param rcode: if not 0, error code.
 763  * @param rep: reply to send (or NULL if rcode is set).
 764  * @param r: callback entry
 765  */
 766 static void
 767 mesh_do_callback(struct mesh_state* m, int rcode, struct reply_info* rep,
 768         struct mesh_cb* r)
 769 {
 770         int secure;
 771         char* reason = NULL;
 772         /* bogus messages are not made into servfail, sec_status passed
 773          * to the callback function */
 774         if(rep && rep->security == sec_status_secure)
 775                 secure = 1;
 776         else    secure = 0;
 777         if(!rep && rcode == LDNS_RCODE_NOERROR)
 778                 rcode = LDNS_RCODE_SERVFAIL;
 779         if(!rcode && rep->security == sec_status_bogus) {
 780                 if(!(reason = errinf_to_str(&m->s)))
 781                         rcode = LDNS_RCODE_SERVFAIL;
 782         }
 783         /* send the reply */
 784         if(rcode) {
 785                 fptr_ok(fptr_whitelist_mesh_cb(r->cb));
 786                 (*r->cb)(r->cb_arg, rcode, r->buf, sec_status_unchecked, NULL);
 787         } else {
 788                 size_t udp_size = r->edns.udp_size;
 789                 ldns_buffer_clear(r->buf);
 790                 r->edns.edns_version = EDNS_ADVERTISED_VERSION;
 791                 r->edns.udp_size = EDNS_ADVERTISED_SIZE;
 792                 r->edns.ext_rcode = 0;
 793                 r->edns.bits &= EDNS_DO;
 794                 if(!reply_info_answer_encode(&m->s.qinfo, rep, r->qid,
 795                         r->qflags, r->buf, 0, 1,
 796                         m->s.env->scratch, udp_size, &r->edns,
 797                         (int)(r->edns.bits & EDNS_DO), secure))
 798                 {
 799                         fptr_ok(fptr_whitelist_mesh_cb(r->cb));
 800                         (*r->cb)(r->cb_arg, LDNS_RCODE_SERVFAIL, r->buf,
 801                                 sec_status_unchecked, NULL);
 802                 } else {
 803                         fptr_ok(fptr_whitelist_mesh_cb(r->cb));
 804                         (*r->cb)(r->cb_arg, LDNS_RCODE_NOERROR, r->buf,
 805                                 rep->security, reason);
 806                 }
 807         }
 808         free(reason);
 809         m->s.env->mesh->num_reply_addrs--;
 810 }
 811
 812 /**
 813  * Send reply to mesh reply entry
 814  * @param m: mesh state to send it for.
 815  * @param rcode: if not 0, error code.
 816  * @param rep: reply to send (or NULL if rcode is set).
 817  * @param r: reply entry
 818  * @param prev: previous reply, already has its answer encoded in buffer.
 819  */
 820 static void
 821 mesh_send_reply(struct mesh_state* m, int rcode, struct reply_info* rep,
 822         struct mesh_reply* r, struct mesh_reply* prev)
 823 {
 824         struct timeval end_time;
 825         struct timeval duration;
 826         int secure;
 827         /* examine security status */
 828         if(m->s.env->need_to_validate && (!(r->qflags&BIT_CD) ||
 829                 m->s.env->cfg->ignore_cd) && rep &&
 830                 rep->security <= sec_status_bogus) {
 831                 rcode = LDNS_RCODE_SERVFAIL;
 832                 if(m->s.env->cfg->stat_extended)
 833                         m->s.env->mesh->ans_bogus++;
 834         }
 835         if(rep && rep->security == sec_status_secure)
 836                 secure = 1;
 837         else    secure = 0;
 838         if(!rep && rcode == LDNS_RCODE_NOERROR)
 839                 rcode = LDNS_RCODE_SERVFAIL;
 840         /* send the reply */
 841         if(prev && prev->qflags == r->qflags &&
 842                 prev->edns.edns_present == r->edns.edns_present &&
 843                 prev->edns.bits == r->edns.bits &&
 844                 prev->edns.udp_size == r->edns.udp_size) {
 845                 /* if the previous reply is identical to this one, fix ID */
 846                 if(prev->query_reply.c->buffer != r->query_reply.c->buffer)
 847                         ldns_buffer_copy(r->query_reply.c->buffer,
 848                                 prev->query_reply.c->buffer);
 849                 ldns_buffer_write_at(r->query_reply.c->buffer, 0,
 850                         &r->qid, sizeof(uint16_t));
 851                 ldns_buffer_write_at(r->query_reply.c->buffer, 12,
 852                         r->qname, m->s.qinfo.qname_len);
 853                 comm_point_send_reply(&r->query_reply);
 854         } else if(rcode) {
 855                 m->s.qinfo.qname = r->qname;
 856                 error_encode(r->query_reply.c->buffer, rcode, &m->s.qinfo,
 857                         r->qid, r->qflags, &r->edns);
 858                 comm_point_send_reply(&r->query_reply);
 859         } else {
 860                 size_t udp_size = r->edns.udp_size;
 861                 r->edns.edns_version = EDNS_ADVERTISED_VERSION;
 862                 r->edns.udp_size = EDNS_ADVERTISED_SIZE;
 863                 r->edns.ext_rcode = 0;
 864                 r->edns.bits &= EDNS_DO;
 865                 m->s.qinfo.qname = r->qname;
 866                 if(!reply_info_answer_encode(&m->s.qinfo, rep, r->qid,
 867                         r->qflags, r->query_reply.c->buffer, 0, 1,
 868                         m->s.env->scratch, udp_size, &r->edns,
 869                         (int)(r->edns.bits & EDNS_DO), secure))
 870                 {
 871                         error_encode(r->query_reply.c->buffer,
 872                                 LDNS_RCODE_SERVFAIL, &m->s.qinfo, r->qid,
 873                                 r->qflags, &r->edns);
 874                 }
 875                 comm_point_send_reply(&r->query_reply);
 876         }
 877         /* account */
 878         m->s.env->mesh->num_reply_addrs--;
 879         end_time = *m->s.env->now_tv;
 880         timeval_subtract(&duration, &end_time, &r->start_time);
 881         verbose(VERB_ALGO, "query took %d.%6.6d sec",
 882                 (int)duration.tv_sec, (int)duration.tv_usec);
 883         m->s.env->mesh->replies_sent++;
 884         timeval_add(&m->s.env->mesh->replies_sum_wait, &duration);
 885         timehist_insert(m->s.env->mesh->histogram, &duration);
 886         if(m->s.env->cfg->stat_extended) {
 887                 uint16_t rc = FLAGS_GET_RCODE(ldns_buffer_read_u16_at(r->
 888                         query_reply.c->buffer, 2));
 889                 if(secure) m->s.env->mesh->ans_secure++;
 890                 m->s.env->mesh->ans_rcode[ rc ] ++;
 891                 if(rc == 0 && LDNS_ANCOUNT(ldns_buffer_begin(r->
 892                         query_reply.c->buffer)) == 0)
 893                         m->s.env->mesh->ans_nodata++;
 894         }
 895 }
 896
 897 void mesh_query_done(struct mesh_state* mstate)
 898 {
 899         struct mesh_reply* r;
 900         struct mesh_reply* prev = NULL;
 901         struct mesh_cb* c;
 902         struct reply_info* rep = (mstate->s.return_msg?
 903                 mstate->s.return_msg->rep:NULL);
 904         for(r = mstate->reply_list; r; r = r->next) {
 905                 mesh_send_reply(mstate, mstate->s.return_rcode, rep, r, prev);
 906                 prev = r;
 907         }
 908         mstate->replies_sent = 1;
 909         for(c = mstate->cb_list; c; c = c->next) {
 910                 mesh_do_callback(mstate, mstate->s.return_rcode, rep, c);
 911         }
 912 }
 913
 914 void mesh_walk_supers(struct mesh_area* mesh, struct mesh_state* mstate)
 915 {
 916         struct mesh_state_ref* ref;
 917         RBTREE_FOR(ref, struct mesh_state_ref*, &mstate->super_set)
 918         {
 919                 /* make super runnable */
 920                 (void)rbtree_insert(&mesh->run, &ref->s->run_node);
 921                 /* callback the function to inform super of result */
 922                 fptr_ok(fptr_whitelist_mod_inform_super(
 923                         mesh->mods.mod[ref->s->s.curmod]->inform_super));
 924                 (*mesh->mods.mod[ref->s->s.curmod]->inform_super)(&mstate->s,
 925                         ref->s->s.curmod, &ref->s->s);
 926         }
 927 }
 928
 929 struct mesh_state* mesh_area_find(struct mesh_area* mesh,
 930         struct query_info* qinfo, uint16_t qflags, int prime)
 931 {
 932         struct mesh_state key;
 933         struct mesh_state* result;
 934
 935         key.node.key = &key;
 936         key.s.is_priming = prime;
 937         key.s.qinfo = *qinfo;
 938         key.s.query_flags = qflags;
 939
 940         result = (struct mesh_state*)rbtree_search(&mesh->all, &key);
 941         return result;
 942 }
 943
 944 int mesh_state_add_cb(struct mesh_state* s, struct edns_data* edns,
 945         ldns_buffer* buf, mesh_cb_func_t cb, void* cb_arg,
 946         uint16_t qid, uint16_t qflags)
 947 {
 948         struct mesh_cb* r = regional_alloc(s->s.region,
 949                 sizeof(struct mesh_cb));
 950         if(!r)
 951                 return 0;
 952         r->buf = buf;
 953         log_assert(fptr_whitelist_mesh_cb(cb)); /* early failure ifmissing*/
 954         r->cb = cb;
 955         r->cb_arg = cb_arg;
 956         r->edns = *edns;
 957         r->qid = qid;
 958         r->qflags = qflags;
 959         r->next = s->cb_list;
 960         s->cb_list = r;
 961         return 1;
 962
 963 }
 964
 965 int mesh_state_add_reply(struct mesh_state* s, struct edns_data* edns,
 966         struct comm_reply* rep, uint16_t qid, uint16_t qflags, uint8_t* qname)
 967 {
 968         struct mesh_reply* r = regional_alloc(s->s.region,
 969                 sizeof(struct mesh_reply));
 970         if(!r)
 971                 return 0;
 972         r->query_reply = *rep;
 973         r->edns = *edns;
 974         r->qid = qid;
 975         r->qflags = qflags;
 976         r->start_time = *s->s.env->now_tv;
 977         r->next = s->reply_list;
 978         r->qname = regional_alloc_init(s->s.region, qname,
 979                 s->s.qinfo.qname_len);
 980         if(!r->qname)
 981                 return 0;
 982         s->reply_list = r;
 983         return 1;
 984
 985 }
 986
 987 /**
 988  * Continue processing the mesh state at another module.
 989  * Handles module to modules tranfer of control.
 990  * Handles module finished.
 991  * @param mesh: the mesh area.
 992  * @param mstate: currently active mesh state.
 993  *      Deleted if finished, calls _done and _supers to
 994  *      send replies to clients and inform other mesh states.
 995  *      This in turn may create additional runnable mesh states.
 996  * @param s: state at which the current module exited.
 997  * @param ev: the event sent to the module.
 998  *      returned is the event to send to the next module.
 999  * @return true if continue processing at the new module.
1000  *      false if not continued processing is needed.
1001  */
1002 static int
1003 mesh_continue(struct mesh_area* mesh, struct mesh_state* mstate,
1004         enum module_ext_state s, enum module_ev* ev)
1005 {
1006         mstate->num_activated++;
1007         if(mstate->num_activated > MESH_MAX_ACTIVATION) {
1008                 /* module is looping. Stop it. */
1009                 log_err("internal error: looping module stopped");
1010                 log_query_info(VERB_QUERY, "pass error for qstate",
1011                         &mstate->s.qinfo);
1012                 s = module_error;
1013         }
1014         if(s == module_wait_module || s == module_restart_next) {
1015                 /* start next module */
1016                 mstate->s.curmod++;
1017                 if(mesh->mods.num == mstate->s.curmod) {
1018                         log_err("Cannot pass to next module; at last module");
1019                         log_query_info(VERB_QUERY, "pass error for qstate",
1020                                 &mstate->s.qinfo);
1021                         mstate->s.curmod--;
1022                         return mesh_continue(mesh, mstate, module_error, ev);
1023                 }
1024                 if(s == module_restart_next) {
1025                         fptr_ok(fptr_whitelist_mod_clear(
1026                                 mesh->mods.mod[mstate->s.curmod]->clear));
1027                         (*mesh->mods.mod[mstate->s.curmod]->clear)
1028                                 (&mstate->s, mstate->s.curmod);
1029                         mstate->s.minfo[mstate->s.curmod] = NULL;
1030                 }
1031                 *ev = module_event_pass;
1032                 return 1;
1033         }
1034         if(s == module_error && mstate->s.return_rcode == LDNS_RCODE_NOERROR) {
1035                 /* error is bad, handle pass back up below */
1036                 mstate->s.return_rcode = LDNS_RCODE_SERVFAIL;
1037         }
1038         if(s == module_error || s == module_finished) {
1039                 if(mstate->s.curmod == 0) {
1040                         mesh_query_done(mstate);
1041                         mesh_walk_supers(mesh, mstate);
1042                         mesh_state_delete(&mstate->s);
1043                         return 0;
1044                 }
1045                 /* pass along the locus of control */
1046                 mstate->s.curmod --;
1047                 *ev = module_event_moddone;
1048                 return 1;
1049         }
1050         return 0;
1051 }
1052
1053 void mesh_run(struct mesh_area* mesh, struct mesh_state* mstate,
1054         enum module_ev ev, struct outbound_entry* e)
1055 {
1056         enum module_ext_state s;
1057         verbose(VERB_ALGO, "mesh_run: start");
1058         while(mstate) {
1059                 /* run the module */
1060                 fptr_ok(fptr_whitelist_mod_operate(
1061                         mesh->mods.mod[mstate->s.curmod]->operate));
1062                 (*mesh->mods.mod[mstate->s.curmod]->operate)
1063                         (&mstate->s, ev, mstate->s.curmod, e);
1064
1065                 /* examine results */
1066                 mstate->s.reply = NULL;
1067                 regional_free_all(mstate->s.env->scratch);
1068                 s = mstate->s.ext_state[mstate->s.curmod];
1069                 verbose(VERB_ALGO, "mesh_run: %s module exit state is %s",
1070                         mesh->mods.mod[mstate->s.curmod]->name, strextstate(s));
1071                 e = NULL;
1072                 if(mesh_continue(mesh, mstate, s, &ev))
1073                         continue;
1074
1075                 /* run more modules */
1076                 ev = module_event_pass;
1077                 if(mesh->run.count > 0) {
1078                         /* pop random element off the runnable tree */
1079                         mstate = (struct mesh_state*)mesh->run.root->key;
1080                         (void)rbtree_delete(&mesh->run, mstate);
1081                 } else mstate = NULL;
1082         }
1083         if(verbosity >= VERB_ALGO) {
1084                 mesh_stats(mesh, "mesh_run: end");
1085                 mesh_log_list(mesh);
1086         }
1087 }
1088
1089 void
1090 mesh_log_list(struct mesh_area* mesh)
1091 {
1092         char buf[30];
1093         struct mesh_state* m;
1094         int num = 0;
1095         RBTREE_FOR(m, struct mesh_state*, &mesh->all) {
1096                 snprintf(buf, sizeof(buf), "%d%s%s%s%s%s mod%d %s%s",
1097                         num++, (m->s.is_priming)?"p":"",  /* prime */
1098                         (m->s.query_flags&BIT_RD)?"RD":"",
1099                         (m->s.query_flags&BIT_CD)?"CD":"",
1100                         (m->super_set.count==0)?"d":"", /* detached */
1101                         (m->sub_set.count!=0)?"c":"",  /* children */
1102                         m->s.curmod, (m->reply_list)?"rep":"", /*hasreply*/
1103                         (m->cb_list)?"cb":"" /* callbacks */
1104                         );
1105                 log_query_info(VERB_ALGO, buf, &m->s.qinfo);
1106         }
1107 }
1108
1109 void
1110 mesh_stats(struct mesh_area* mesh, const char* str)
1111 {
1112         verbose(VERB_DETAIL, "%s %u recursion states (%u with reply, "
1113                 "%u detached), %u waiting replies, %u recursion replies "
1114                 "sent, %d replies dropped, %d states jostled out",
1115                 str, (unsigned)mesh->all.count,
1116                 (unsigned)mesh->num_reply_states,
1117                 (unsigned)mesh->num_detached_states,
1118                 (unsigned)mesh->num_reply_addrs,
1119                 (unsigned)mesh->replies_sent,
1120                 (unsigned)mesh->stats_dropped,
1121                 (unsigned)mesh->stats_jostled);
1122         if(mesh->replies_sent > 0) {
1123                 struct timeval avg;
1124                 timeval_divide(&avg, &mesh->replies_sum_wait,
1125                         mesh->replies_sent);
1126                 log_info("average recursion processing time "
1127                         "%d.%6.6d sec", (int)avg.tv_sec, (int)avg.tv_usec);
1128                 log_info("histogram of recursion processing times");
1129                 timehist_log(mesh->histogram, "recursions");
1130         }
1131 }
1132
1133 void
1134 mesh_stats_clear(struct mesh_area* mesh)
1135 {
1136         if(!mesh)
1137                 return;
1138         mesh->replies_sent = 0;
1139         mesh->replies_sum_wait.tv_sec = 0;
1140         mesh->replies_sum_wait.tv_usec = 0;
1141         mesh->stats_jostled = 0;
1142         mesh->stats_dropped = 0;
1143         timehist_clear(mesh->histogram);
1144         mesh->ans_secure = 0;
1145         mesh->ans_bogus = 0;
1146         memset(&mesh->ans_rcode[0], 0, sizeof(size_t)*16);
1147         mesh->ans_nodata = 0;
1148 }
1149
1150 size_t
1151 mesh_get_mem(struct mesh_area* mesh)
1152 {
1153         struct mesh_state* m;
1154         size_t s = sizeof(*mesh) + sizeof(struct timehist) +
1155                 sizeof(struct th_buck)*mesh->histogram->num +
1156                 sizeof(ldns_buffer) + ldns_buffer_capacity(mesh->qbuf_bak);
1157         RBTREE_FOR(m, struct mesh_state*, &mesh->all) {
1158                 /* all, including m itself allocated in qstate region */
1159                 s += regional_get_mem(m->s.region);
1160         }
1161         return s;
1162 }
1163
1164 int
1165 mesh_detect_cycle(struct module_qstate* qstate, struct query_info* qinfo,
1166         uint16_t flags, int prime)
1167 {
1168         struct mesh_area* mesh = qstate->env->mesh;
1169         struct mesh_state* dep_m = mesh_area_find(mesh, qinfo, flags, prime);
1170         return mesh_detect_cycle_found(qstate, dep_m);
1171 }
1172
1173 void mesh_list_insert(struct mesh_state* m, struct mesh_state** fp,
1174         struct mesh_state** lp)
1175 {
1176         /* insert as last element */
1177         m->prev = *lp;
1178         m->next = NULL;
1179         if(*lp)
1180                 (*lp)->next = m;
1181         else    *fp = m;
1182         *lp = m;
1183 }
1184
1185 void mesh_list_remove(struct mesh_state* m, struct mesh_state** fp,
1186         struct mesh_state** lp)
1187 {
1188         if(m->next)
1189                 m->next->prev = m->prev;
1190         else    *lp = m->prev;
1191         if(m->prev)
1192                 m->prev->next = m->next;
1193         else    *fp = m->next;
1194 }