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 "util/log.h"
  50 #include "util/net_help.h"
  51 #include "util/module.h"
  52 #include "util/regional.h"
  53 #include "util/data/msgencode.h"
  54 #include "util/timehist.h"
  55 #include "util/fptr_wlist.h"
  56 #include "util/alloc.h"
  57 #include "util/config_file.h"
  58 #include "sldns/sbuffer.h"
  59 #include "sldns/wire2str.h"
  60 #include "services/localzone.h"
  61 #include "util/data/dname.h"
  62
  63 /** subtract timers and the values do not overflow or become negative */
  64 static void
  65 timeval_subtract(struct timeval* d, const struct timeval* end, const struct timeval* start)
  66 {
  67 #ifndef S_SPLINT_S
  68         time_t end_usec = end->tv_usec;
  69         d->tv_sec = end->tv_sec - start->tv_sec;
  70         if(end_usec < start->tv_usec) {
  71                 end_usec += 1000000;
  72                 d->tv_sec--;
  73         }
  74         d->tv_usec = end_usec - start->tv_usec;
  75 #endif
  76 }
  77
  78 /** add timers and the values do not overflow or become negative */
  79 static void
  80 timeval_add(struct timeval* d, const struct timeval* add)
  81 {
  82 #ifndef S_SPLINT_S
  83         d->tv_sec += add->tv_sec;
  84         d->tv_usec += add->tv_usec;
  85         if(d->tv_usec > 1000000 ) {
  86                 d->tv_usec -= 1000000;
  87                 d->tv_sec++;
  88         }
  89 #endif
  90 }
  91
  92 /** divide sum of timers to get average */
  93 static void
  94 timeval_divide(struct timeval* avg, const struct timeval* sum, size_t d)
  95 {
  96 #ifndef S_SPLINT_S
  97         size_t leftover;
  98         if(d == 0) {
  99                 avg->tv_sec = 0;
 100                 avg->tv_usec = 0;
 101                 return;
 102         }
 103         avg->tv_sec = sum->tv_sec / d;
 104         avg->tv_usec = sum->tv_usec / d;
 105         /* handle fraction from seconds divide */
 106         leftover = sum->tv_sec - avg->tv_sec*d;
 107         avg->tv_usec += (leftover*1000000)/d;
 108 #endif
 109 }
 110
 111 /** histogram compare of time values */
 112 static int
 113 timeval_smaller(const struct timeval* x, const struct timeval* y)
 114 {
 115 #ifndef S_SPLINT_S
 116         if(x->tv_sec < y->tv_sec)
 117                 return 1;
 118         else if(x->tv_sec == y->tv_sec) {
 119                 if(x->tv_usec <= y->tv_usec)
 120                         return 1;
 121                 else    return 0;
 122         }
 123         else    return 0;
 124 #endif
 125 }
 126
 127 int
 128 mesh_state_compare(const void* ap, const void* bp)
 129 {
 130         struct mesh_state* a = (struct mesh_state*)ap;
 131         struct mesh_state* b = (struct mesh_state*)bp;
 132
 133         if(a->unique < b->unique)
 134                 return -1;
 135         if(a->unique > b->unique)
 136                 return 1;
 137
 138         if(a->s.is_priming && !b->s.is_priming)
 139                 return -1;
 140         if(!a->s.is_priming && b->s.is_priming)
 141                 return 1;
 142
 143         if(a->s.is_valrec && !b->s.is_valrec)
 144                 return -1;
 145         if(!a->s.is_valrec && b->s.is_valrec)
 146                 return 1;
 147
 148         if((a->s.query_flags&BIT_RD) && !(b->s.query_flags&BIT_RD))
 149                 return -1;
 150         if(!(a->s.query_flags&BIT_RD) && (b->s.query_flags&BIT_RD))
 151                 return 1;
 152
 153         if((a->s.query_flags&BIT_CD) && !(b->s.query_flags&BIT_CD))
 154                 return -1;
 155         if(!(a->s.query_flags&BIT_CD) && (b->s.query_flags&BIT_CD))
 156                 return 1;
 157
 158         return query_info_compare(&a->s.qinfo, &b->s.qinfo);
 159 }
 160
 161 int
 162 mesh_state_ref_compare(const void* ap, const void* bp)
 163 {
 164         struct mesh_state_ref* a = (struct mesh_state_ref*)ap;
 165         struct mesh_state_ref* b = (struct mesh_state_ref*)bp;
 166         return mesh_state_compare(a->s, b->s);
 167 }
 168
 169 struct mesh_area*
 170 mesh_create(struct module_stack* stack, struct module_env* env)
 171 {
 172         struct mesh_area* mesh = calloc(1, sizeof(struct mesh_area));
 173         if(!mesh) {
 174                 log_err("mesh area alloc: out of memory");
 175                 return NULL;
 176         }
 177         mesh->histogram = timehist_setup();
 178         mesh->qbuf_bak = sldns_buffer_new(env->cfg->msg_buffer_size);
 179         if(!mesh->histogram || !mesh->qbuf_bak) {
 180                 free(mesh);
 181                 log_err("mesh area alloc: out of memory");
 182                 return NULL;
 183         }
 184         mesh->mods = *stack;
 185         mesh->env = env;
 186         rbtree_init(&mesh->run, &mesh_state_compare);
 187         rbtree_init(&mesh->all, &mesh_state_compare);
 188         mesh->num_reply_addrs = 0;
 189         mesh->num_reply_states = 0;
 190         mesh->num_detached_states = 0;
 191         mesh->num_forever_states = 0;
 192         mesh->stats_jostled = 0;
 193         mesh->stats_dropped = 0;
 194         mesh->max_reply_states = env->cfg->num_queries_per_thread;
 195         mesh->max_forever_states = (mesh->max_reply_states+1)/2;
 196 #ifndef S_SPLINT_S
 197         mesh->jostle_max.tv_sec = (time_t)(env->cfg->jostle_time / 1000);
 198         mesh->jostle_max.tv_usec = (time_t)((env->cfg->jostle_time % 1000)
 199                 *1000);
 200 #endif
 201         return mesh;
 202 }
 203
 204 /** help mesh delete delete mesh states */
 205 static void
 206 mesh_delete_helper(rbnode_t* n)
 207 {
 208         struct mesh_state* mstate = (struct mesh_state*)n->key;
 209         /* perform a full delete, not only 'cleanup' routine,
 210          * because other callbacks expect a clean state in the mesh.
 211          * For 're-entrant' calls */
 212         mesh_state_delete(&mstate->s);
 213         /* but because these delete the items from the tree, postorder
 214          * traversal and rbtree rebalancing do not work together */
 215 }
 216
 217 void
 218 mesh_delete(struct mesh_area* mesh)
 219 {
 220         if(!mesh)
 221                 return;
 222         /* free all query states */
 223         while(mesh->all.count)
 224                 mesh_delete_helper(mesh->all.root);
 225         timehist_delete(mesh->histogram);
 226         sldns_buffer_free(mesh->qbuf_bak);
 227         free(mesh);
 228 }
 229
 230 void
 231 mesh_delete_all(struct mesh_area* mesh)
 232 {
 233         /* free all query states */
 234         while(mesh->all.count)
 235                 mesh_delete_helper(mesh->all.root);
 236         mesh->stats_dropped += mesh->num_reply_addrs;
 237         /* clear mesh area references */
 238         rbtree_init(&mesh->run, &mesh_state_compare);
 239         rbtree_init(&mesh->all, &mesh_state_compare);
 240         mesh->num_reply_addrs = 0;
 241         mesh->num_reply_states = 0;
 242         mesh->num_detached_states = 0;
 243         mesh->num_forever_states = 0;
 244         mesh->forever_first = NULL;
 245         mesh->forever_last = NULL;
 246         mesh->jostle_first = NULL;
 247         mesh->jostle_last = NULL;
 248 }
 249
 250 int mesh_make_new_space(struct mesh_area* mesh, sldns_buffer* qbuf)
 251 {
 252         struct mesh_state* m = mesh->jostle_first;
 253         /* free space is available */
 254         if(mesh->num_reply_states < mesh->max_reply_states)
 255                 return 1;
 256         /* try to kick out a jostle-list item */
 257         if(m && m->reply_list && m->list_select == mesh_jostle_list) {
 258                 /* how old is it? */
 259                 struct timeval age;
 260                 timeval_subtract(&age, mesh->env->now_tv,
 261                         &m->reply_list->start_time);
 262                 if(timeval_smaller(&mesh->jostle_max, &age)) {
 263                         /* its a goner */
 264                         log_nametypeclass(VERB_ALGO, "query jostled out to "
 265                                 "make space for a new one",
 266                                 m->s.qinfo.qname, m->s.qinfo.qtype,
 267                                 m->s.qinfo.qclass);
 268                         /* backup the query */
 269                         if(qbuf) sldns_buffer_copy(mesh->qbuf_bak, qbuf);
 270                         /* notify supers */
 271                         if(m->super_set.count > 0) {
 272                                 verbose(VERB_ALGO, "notify supers of failure");
 273                                 m->s.return_msg = NULL;
 274                                 m->s.return_rcode = LDNS_RCODE_SERVFAIL;
 275                                 mesh_walk_supers(mesh, m);
 276                         }
 277                         mesh->stats_jostled ++;
 278                         mesh_state_delete(&m->s);
 279                         /* restore the query - note that the qinfo ptr to
 280                          * the querybuffer is then correct again. */
 281                         if(qbuf) sldns_buffer_copy(qbuf, mesh->qbuf_bak);
 282                         return 1;
 283                 }
 284         }
 285         /* no space for new item */
 286         return 0;
 287 }
 288
 289 void mesh_new_client(struct mesh_area* mesh, struct query_info* qinfo,
 290         uint16_t qflags, struct edns_data* edns, struct comm_reply* rep,
 291         uint16_t qid)
 292 {
 293         struct mesh_state* s = NULL;
 294         int unique = edns_unique_mesh_state(edns->opt_list, mesh->env);
 295         int was_detached = 0;
 296         int was_noreply = 0;
 297         int added = 0;
 298         if(!unique)
 299                 s = mesh_area_find(mesh, qinfo, qflags&(BIT_RD|BIT_CD), 0, 0);
 300         /* does this create a new reply state? */
 301         if(!s || s->list_select == mesh_no_list) {
 302                 if(!mesh_make_new_space(mesh, rep->c->buffer)) {
 303                         verbose(VERB_ALGO, "Too many queries. dropping "
 304                                 "incoming query.");
 305                         comm_point_drop_reply(rep);
 306                         mesh->stats_dropped ++;
 307                         return;
 308                 }
 309                 /* for this new reply state, the reply address is free,
 310                  * so the limit of reply addresses does not stop reply states*/
 311         } else {
 312                 /* protect our memory usage from storing reply addresses */
 313                 if(mesh->num_reply_addrs > mesh->max_reply_states*16) {
 314                         verbose(VERB_ALGO, "Too many requests queued. "
 315                                 "dropping incoming query.");
 316                         mesh->stats_dropped++;
 317                         comm_point_drop_reply(rep);
 318                         return;
 319                 }
 320         }
 321         /* see if it already exists, if not, create one */
 322         if(!s) {
 323 #ifdef UNBOUND_DEBUG
 324                 struct rbnode_t* n;
 325 #endif
 326                 s = mesh_state_create(mesh->env, qinfo, qflags&(BIT_RD|BIT_CD), 0, 0);
 327                 if(!s) {
 328                         log_err("mesh_state_create: out of memory; SERVFAIL");
 329                         if(!inplace_cb_reply_servfail_call(mesh->env, qinfo, NULL, NULL,
 330                                 LDNS_RCODE_SERVFAIL, edns, mesh->env->scratch))
 331                                         edns->opt_list = NULL;
 332                         error_encode(rep->c->buffer, LDNS_RCODE_SERVFAIL,
 333                                 qinfo, qid, qflags, edns);
 334                         comm_point_send_reply(rep);
 335                         return;
 336                 }
 337                 if(unique)
 338                         mesh_state_make_unique(s);
 339                 /* copy the edns options we got from the front */
 340                 if(edns->opt_list) {
 341                         s->s.edns_opts_front_in = edns_opt_copy_region(edns->opt_list,
 342                                 s->s.region);
 343                         if(!s->s.edns_opts_front_in) {
 344                                 log_err("mesh_state_create: out of memory; SERVFAIL");
 345                                 if(!inplace_cb_reply_servfail_call(mesh->env, qinfo, NULL,
 346                                         NULL, LDNS_RCODE_SERVFAIL, edns, mesh->env->scratch))
 347                                                 edns->opt_list = NULL;
 348                                 error_encode(rep->c->buffer, LDNS_RCODE_SERVFAIL,
 349                                         qinfo, qid, qflags, edns);
 350                                 comm_point_send_reply(rep);
 351                                 return;
 352                         }
 353                 }
 354
 355 #ifdef UNBOUND_DEBUG
 356                 n =
 357 #else
 358                 (void)
 359 #endif
 360                 rbtree_insert(&mesh->all, &s->node);
 361                 log_assert(n != NULL);
 362                 /* set detached (it is now) */
 363                 mesh->num_detached_states++;
 364                 added = 1;
 365         }
 366         if(!s->reply_list && !s->cb_list && s->super_set.count == 0)
 367                 was_detached = 1;
 368         if(!s->reply_list && !s->cb_list)
 369                 was_noreply = 1;
 370         /* add reply to s */
 371         if(!mesh_state_add_reply(s, edns, rep, qid, qflags, qinfo)) {
 372                         log_err("mesh_new_client: out of memory; SERVFAIL");
 373                         if(!inplace_cb_reply_servfail_call(mesh->env, qinfo, &s->s,
 374                                 NULL, LDNS_RCODE_SERVFAIL, edns, mesh->env->scratch))
 375                                         edns->opt_list = NULL;
 376                         error_encode(rep->c->buffer, LDNS_RCODE_SERVFAIL,
 377                                 qinfo, qid, qflags, edns);
 378                         comm_point_send_reply(rep);
 379                         if(added)
 380                                 mesh_state_delete(&s->s);
 381                         return;
 382         }
 383         /* update statistics */
 384         if(was_detached) {
 385                 log_assert(mesh->num_detached_states > 0);
 386                 mesh->num_detached_states--;
 387         }
 388         if(was_noreply) {
 389                 mesh->num_reply_states ++;
 390         }
 391         mesh->num_reply_addrs++;
 392         if(s->list_select == mesh_no_list) {
 393                 /* move to either the forever or the jostle_list */
 394                 if(mesh->num_forever_states < mesh->max_forever_states) {
 395                         mesh->num_forever_states ++;
 396                         mesh_list_insert(s, &mesh->forever_first,
 397                                 &mesh->forever_last);
 398                         s->list_select = mesh_forever_list;
 399                 } else {
 400                         mesh_list_insert(s, &mesh->jostle_first,
 401                                 &mesh->jostle_last);
 402                         s->list_select = mesh_jostle_list;
 403                 }
 404         }
 405         if(added)
 406                 mesh_run(mesh, s, module_event_new, NULL);
 407 }
 408
 409 int
 410 mesh_new_callback(struct mesh_area* mesh, struct query_info* qinfo,
 411         uint16_t qflags, struct edns_data* edns, sldns_buffer* buf,
 412         uint16_t qid, mesh_cb_func_t cb, void* cb_arg)
 413 {
 414         struct mesh_state* s = NULL;
 415         int unique = edns_unique_mesh_state(edns->opt_list, mesh->env);
 416         int was_detached = 0;
 417         int was_noreply = 0;
 418         int added = 0;
 419         if(!unique)
 420                 s = mesh_area_find(mesh, qinfo, qflags&(BIT_RD|BIT_CD), 0, 0);
 421         /* there are no limits on the number of callbacks */
 422
 423         /* see if it already exists, if not, create one */
 424         if(!s) {
 425 #ifdef UNBOUND_DEBUG
 426                 struct rbnode_t* n;
 427 #endif
 428                 s = mesh_state_create(mesh->env, qinfo, qflags&(BIT_RD|BIT_CD), 0, 0);
 429                 if(!s) {
 430                         return 0;
 431                 }
 432                 if(unique)
 433                         mesh_state_make_unique(s);
 434                 if(edns->opt_list) {
 435                         s->s.edns_opts_front_in = edns_opt_copy_region(edns->opt_list,
 436                                 s->s.region);
 437                         if(!s->s.edns_opts_front_in) {
 438                                 return 0;
 439                         }
 440                 }
 441 #ifdef UNBOUND_DEBUG
 442                 n =
 443 #else
 444                 (void)
 445 #endif
 446                 rbtree_insert(&mesh->all, &s->node);
 447                 log_assert(n != NULL);
 448                 /* set detached (it is now) */
 449                 mesh->num_detached_states++;
 450                 added = 1;
 451         }
 452         if(!s->reply_list && !s->cb_list && s->super_set.count == 0)
 453                 was_detached = 1;
 454         if(!s->reply_list && !s->cb_list)
 455                 was_noreply = 1;
 456         /* add reply to s */
 457         if(!mesh_state_add_cb(s, edns, buf, cb, cb_arg, qid, qflags)) {
 458                         if(added)
 459                                 mesh_state_delete(&s->s);
 460                         return 0;
 461         }
 462         /* update statistics */
 463         if(was_detached) {
 464                 log_assert(mesh->num_detached_states > 0);
 465                 mesh->num_detached_states--;
 466         }
 467         if(was_noreply) {
 468                 mesh->num_reply_states ++;
 469         }
 470         mesh->num_reply_addrs++;
 471         if(added)
 472                 mesh_run(mesh, s, module_event_new, NULL);
 473         return 1;
 474 }
 475
 476 void mesh_new_prefetch(struct mesh_area* mesh, struct query_info* qinfo,
 477         uint16_t qflags, time_t leeway)
 478 {
 479         struct mesh_state* s = mesh_area_find(mesh, qinfo, qflags&(BIT_RD|BIT_CD),
 480                 0, 0);
 481 #ifdef UNBOUND_DEBUG
 482         struct rbnode_t* n;
 483 #endif
 484         /* already exists, and for a different purpose perhaps.
 485          * if mesh_no_list, keep it that way. */
 486         if(s) {
 487                 /* make it ignore the cache from now on */
 488                 if(!s->s.blacklist)
 489                         sock_list_insert(&s->s.blacklist, NULL, 0, s->s.region);
 490                 if(s->s.prefetch_leeway < leeway)
 491                         s->s.prefetch_leeway = leeway;
 492                 return;
 493         }
 494         if(!mesh_make_new_space(mesh, NULL)) {
 495                 verbose(VERB_ALGO, "Too many queries. dropped prefetch.");
 496                 mesh->stats_dropped ++;
 497                 return;
 498         }
 499
 500         s = mesh_state_create(mesh->env, qinfo, qflags&(BIT_RD|BIT_CD), 0, 0);
 501         if(!s) {
 502                 log_err("prefetch mesh_state_create: out of memory");
 503                 return;
 504         }
 505 #ifdef UNBOUND_DEBUG
 506         n =
 507 #else
 508         (void)
 509 #endif
 510         rbtree_insert(&mesh->all, &s->node);
 511         log_assert(n != NULL);
 512         /* set detached (it is now) */
 513         mesh->num_detached_states++;
 514         /* make it ignore the cache */
 515         sock_list_insert(&s->s.blacklist, NULL, 0, s->s.region);
 516         s->s.prefetch_leeway = leeway;
 517
 518         if(s->list_select == mesh_no_list) {
 519                 /* move to either the forever or the jostle_list */
 520                 if(mesh->num_forever_states < mesh->max_forever_states) {
 521                         mesh->num_forever_states ++;
 522                         mesh_list_insert(s, &mesh->forever_first,
 523                                 &mesh->forever_last);
 524                         s->list_select = mesh_forever_list;
 525                 } else {
 526                         mesh_list_insert(s, &mesh->jostle_first,
 527                                 &mesh->jostle_last);
 528                         s->list_select = mesh_jostle_list;
 529                 }
 530         }
 531         mesh_run(mesh, s, module_event_new, NULL);
 532 }
 533
 534 void mesh_report_reply(struct mesh_area* mesh, struct outbound_entry* e,
 535         struct comm_reply* reply, int what)
 536 {
 537         enum module_ev event = module_event_reply;
 538         e->qstate->reply = reply;
 539         if(what != NETEVENT_NOERROR) {
 540                 event = module_event_noreply;
 541                 if(what == NETEVENT_CAPSFAIL)
 542                         event = module_event_capsfail;
 543         }
 544         mesh_run(mesh, e->qstate->mesh_info, event, e);
 545 }
 546
 547 struct mesh_state*
 548 mesh_state_create(struct module_env* env, struct query_info* qinfo,
 549         uint16_t qflags, int prime, int valrec)
 550 {
 551         struct regional* region = alloc_reg_obtain(env->alloc);
 552         struct mesh_state* mstate;
 553         int i;
 554         if(!region)
 555                 return NULL;
 556         mstate = (struct mesh_state*)regional_alloc(region,
 557                 sizeof(struct mesh_state));
 558         if(!mstate) {
 559                 alloc_reg_release(env->alloc, region);
 560                 return NULL;
 561         }
 562         memset(mstate, 0, sizeof(*mstate));
 563         mstate->node = *RBTREE_NULL;
 564         mstate->run_node = *RBTREE_NULL;
 565         mstate->node.key = mstate;
 566         mstate->run_node.key = mstate;
 567         mstate->reply_list = NULL;
 568         mstate->list_select = mesh_no_list;
 569         mstate->replies_sent = 0;
 570         rbtree_init(&mstate->super_set, &mesh_state_ref_compare);
 571         rbtree_init(&mstate->sub_set, &mesh_state_ref_compare);
 572         mstate->num_activated = 0;
 573         mstate->unique = NULL;
 574         /* init module qstate */
 575         mstate->s.qinfo.qtype = qinfo->qtype;
 576         mstate->s.qinfo.qclass = qinfo->qclass;
 577         mstate->s.qinfo.local_alias = NULL;
 578         mstate->s.qinfo.qname_len = qinfo->qname_len;
 579         mstate->s.qinfo.qname = regional_alloc_init(region, qinfo->qname,
 580                 qinfo->qname_len);
 581         if(!mstate->s.qinfo.qname) {
 582                 alloc_reg_release(env->alloc, region);
 583                 return NULL;
 584         }
 585         /* remove all weird bits from qflags */
 586         mstate->s.query_flags = (qflags & (BIT_RD|BIT_CD));
 587         mstate->s.is_priming = prime;
 588         mstate->s.is_valrec = valrec;
 589         mstate->s.reply = NULL;
 590         mstate->s.region = region;
 591         mstate->s.curmod = 0;
 592         mstate->s.return_msg = 0;
 593         mstate->s.return_rcode = LDNS_RCODE_NOERROR;
 594         mstate->s.env = env;
 595         mstate->s.mesh_info = mstate;
 596         mstate->s.prefetch_leeway = 0;
 597         mstate->s.no_cache_lookup = 0;
 598         mstate->s.no_cache_store = 0;
 599         /* init modules */
 600         for(i=0; i<env->mesh->mods.num; i++) {
 601                 mstate->s.minfo[i] = NULL;
 602                 mstate->s.ext_state[i] = module_state_initial;
 603         }
 604         /* init edns option lists */
 605         mstate->s.edns_opts_front_in = NULL;
 606         mstate->s.edns_opts_back_out = NULL;
 607         mstate->s.edns_opts_back_in = NULL;
 608         mstate->s.edns_opts_front_out = NULL;
 609
 610         return mstate;
 611 }
 612
 613 int
 614 mesh_state_is_unique(struct mesh_state* mstate)
 615 {
 616         return mstate->unique != NULL;
 617 }
 618
 619 void
 620 mesh_state_make_unique(struct mesh_state* mstate)
 621 {
 622         mstate->unique = mstate;
 623 }
 624
 625 void
 626 mesh_state_cleanup(struct mesh_state* mstate)
 627 {
 628         struct mesh_area* mesh;
 629         int i;
 630         if(!mstate)
 631                 return;
 632         mesh = mstate->s.env->mesh;
 633         /* drop unsent replies */
 634         if(!mstate->replies_sent) {
 635                 struct mesh_reply* rep;
 636                 struct mesh_cb* cb;
 637                 for(rep=mstate->reply_list; rep; rep=rep->next) {
 638                         comm_point_drop_reply(&rep->query_reply);
 639                         mesh->num_reply_addrs--;
 640                 }
 641                 for(cb=mstate->cb_list; cb; cb=cb->next) {
 642                         fptr_ok(fptr_whitelist_mesh_cb(cb->cb));
 643                         (*cb->cb)(cb->cb_arg, LDNS_RCODE_SERVFAIL, NULL,
 644                                 sec_status_unchecked, NULL);
 645                         mesh->num_reply_addrs--;
 646                 }
 647         }
 648
 649         /* de-init modules */
 650         for(i=0; i<mesh->mods.num; i++) {
 651                 fptr_ok(fptr_whitelist_mod_clear(mesh->mods.mod[i]->clear));
 652                 (*mesh->mods.mod[i]->clear)(&mstate->s, i);
 653                 mstate->s.minfo[i] = NULL;
 654                 mstate->s.ext_state[i] = module_finished;
 655         }
 656         alloc_reg_release(mstate->s.env->alloc, mstate->s.region);
 657 }
 658
 659 void
 660 mesh_state_delete(struct module_qstate* qstate)
 661 {
 662         struct mesh_area* mesh;
 663         struct mesh_state_ref* super, ref;
 664         struct mesh_state* mstate;
 665         if(!qstate)
 666                 return;
 667         mstate = qstate->mesh_info;
 668         mesh = mstate->s.env->mesh;
 669         mesh_detach_subs(&mstate->s);
 670         if(mstate->list_select == mesh_forever_list) {
 671                 mesh->num_forever_states --;
 672                 mesh_list_remove(mstate, &mesh->forever_first,
 673                         &mesh->forever_last);
 674         } else if(mstate->list_select == mesh_jostle_list) {
 675                 mesh_list_remove(mstate, &mesh->jostle_first,
 676                         &mesh->jostle_last);
 677         }
 678         if(!mstate->reply_list && !mstate->cb_list
 679                 && mstate->super_set.count == 0) {
 680                 log_assert(mesh->num_detached_states > 0);
 681                 mesh->num_detached_states--;
 682         }
 683         if(mstate->reply_list || mstate->cb_list) {
 684                 log_assert(mesh->num_reply_states > 0);
 685                 mesh->num_reply_states--;
 686         }
 687         ref.node.key = &ref;
 688         ref.s = mstate;
 689         RBTREE_FOR(super, struct mesh_state_ref*, &mstate->super_set) {
 690                 (void)rbtree_delete(&super->s->sub_set, &ref);
 691         }
 692         (void)rbtree_delete(&mesh->run, mstate);
 693         (void)rbtree_delete(&mesh->all, mstate);
 694         mesh_state_cleanup(mstate);
 695 }
 696
 697 /** helper recursive rbtree find routine */
 698 static int
 699 find_in_subsub(struct mesh_state* m, struct mesh_state* tofind, size_t *c)
 700 {
 701         struct mesh_state_ref* r;
 702         if((*c)++ > MESH_MAX_SUBSUB)
 703                 return 1;
 704         RBTREE_FOR(r, struct mesh_state_ref*, &m->sub_set) {
 705                 if(r->s == tofind || find_in_subsub(r->s, tofind, c))
 706                         return 1;
 707         }
 708         return 0;
 709 }
 710
 711 /** find cycle for already looked up mesh_state */
 712 static int
 713 mesh_detect_cycle_found(struct module_qstate* qstate, struct mesh_state* dep_m)
 714 {
 715         struct mesh_state* cyc_m = qstate->mesh_info;
 716         size_t counter = 0;
 717         if(!dep_m)
 718                 return 0;
 719         if(dep_m == cyc_m || find_in_subsub(dep_m, cyc_m, &counter)) {
 720                 if(counter > MESH_MAX_SUBSUB)
 721                         return 2;
 722                 return 1;
 723         }
 724         return 0;
 725 }
 726
 727 void mesh_detach_subs(struct module_qstate* qstate)
 728 {
 729         struct mesh_area* mesh = qstate->env->mesh;
 730         struct mesh_state_ref* ref, lookup;
 731 #ifdef UNBOUND_DEBUG
 732         struct rbnode_t* n;
 733 #endif
 734         lookup.node.key = &lookup;
 735         lookup.s = qstate->mesh_info;
 736         RBTREE_FOR(ref, struct mesh_state_ref*, &qstate->mesh_info->sub_set) {
 737 #ifdef UNBOUND_DEBUG
 738                 n =
 739 #else
 740                 (void)
 741 #endif
 742                 rbtree_delete(&ref->s->super_set, &lookup);
 743                 log_assert(n != NULL); /* must have been present */
 744                 if(!ref->s->reply_list && !ref->s->cb_list
 745                         && ref->s->super_set.count == 0) {
 746                         mesh->num_detached_states++;
 747                         log_assert(mesh->num_detached_states +
 748                                 mesh->num_reply_states <= mesh->all.count);
 749                 }
 750         }
 751         rbtree_init(&qstate->mesh_info->sub_set, &mesh_state_ref_compare);
 752 }
 753
 754 int mesh_attach_sub(struct module_qstate* qstate, struct query_info* qinfo,
 755         uint16_t qflags, int prime, int valrec, struct module_qstate** newq)
 756 {
 757         /* find it, if not, create it */
 758         struct mesh_area* mesh = qstate->env->mesh;
 759         struct mesh_state* sub = mesh_area_find(mesh, qinfo, qflags, prime, valrec);
 760         int was_detached;
 761         if(mesh_detect_cycle_found(qstate, sub)) {
 762                 verbose(VERB_ALGO, "attach failed, cycle detected");
 763                 return 0;
 764         }
 765         if(!sub) {
 766 #ifdef UNBOUND_DEBUG
 767                 struct rbnode_t* n;
 768 #endif
 769                 /* create a new one */
 770                 sub = mesh_state_create(qstate->env, qinfo, qflags, prime, valrec);
 771                 if(!sub) {
 772                         log_err("mesh_attach_sub: out of memory");
 773                         return 0;
 774                 }
 775 #ifdef UNBOUND_DEBUG
 776                 n =
 777 #else
 778                 (void)
 779 #endif
 780                 rbtree_insert(&mesh->all, &sub->node);
 781                 log_assert(n != NULL);
 782                 /* set detached (it is now) */
 783                 mesh->num_detached_states++;
 784                 /* set new query state to run */
 785 #ifdef UNBOUND_DEBUG
 786                 n =
 787 #else
 788                 (void)
 789 #endif
 790                 rbtree_insert(&mesh->run, &sub->run_node);
 791                 log_assert(n != NULL);
 792                 *newq = &sub->s;
 793         } else
 794                 *newq = NULL;
 795         was_detached = (sub->super_set.count == 0);
 796         if(!mesh_state_attachment(qstate->mesh_info, sub))
 797                 return 0;
 798         /* if it was a duplicate  attachment, the count was not zero before */
 799         if(!sub->reply_list && !sub->cb_list && was_detached &&
 800                 sub->super_set.count == 1) {
 801                 /* it used to be detached, before this one got added */
 802                 log_assert(mesh->num_detached_states > 0);
 803                 mesh->num_detached_states--;
 804         }
 805         /* *newq will be run when inited after the current module stops */
 806         return 1;
 807 }
 808
 809 int mesh_state_attachment(struct mesh_state* super, struct mesh_state* sub)
 810 {
 811 #ifdef UNBOUND_DEBUG
 812         struct rbnode_t* n;
 813 #endif
 814         struct mesh_state_ref* subref; /* points to sub, inserted in super */
 815         struct mesh_state_ref* superref; /* points to super, inserted in sub */
 816         if( !(subref = regional_alloc(super->s.region,
 817                 sizeof(struct mesh_state_ref))) ||
 818                 !(superref = regional_alloc(sub->s.region,
 819                 sizeof(struct mesh_state_ref))) ) {
 820                 log_err("mesh_state_attachment: out of memory");
 821                 return 0;
 822         }
 823         superref->node.key = superref;
 824         superref->s = super;
 825         subref->node.key = subref;
 826         subref->s = sub;
 827         if(!rbtree_insert(&sub->super_set, &superref->node)) {
 828                 /* this should not happen, iterator and validator do not
 829                  * attach subqueries that are identical. */
 830                 /* already attached, we are done, nothing todo.
 831                  * since superref and subref already allocated in region,
 832                  * we cannot free them */
 833                 return 1;
 834         }
 835 #ifdef UNBOUND_DEBUG
 836         n =
 837 #else
 838         (void)
 839 #endif
 840         rbtree_insert(&super->sub_set, &subref->node);
 841         log_assert(n != NULL); /* we checked above if statement, the reverse
 842           administration should not fail now, unless they are out of sync */
 843         return 1;
 844 }
 845
 846 /**
 847  * callback results to mesh cb entry
 848  * @param m: mesh state to send it for.
 849  * @param rcode: if not 0, error code.
 850  * @param rep: reply to send (or NULL if rcode is set).
 851  * @param r: callback entry
 852  */
 853 static void
 854 mesh_do_callback(struct mesh_state* m, int rcode, struct reply_info* rep,
 855         struct mesh_cb* r)
 856 {
 857         int secure;
 858         char* reason = NULL;
 859         /* bogus messages are not made into servfail, sec_status passed
 860          * to the callback function */
 861         if(rep && rep->security == sec_status_secure)
 862                 secure = 1;
 863         else    secure = 0;
 864         if(!rep && rcode == LDNS_RCODE_NOERROR)
 865                 rcode = LDNS_RCODE_SERVFAIL;
 866         if(!rcode && rep->security == sec_status_bogus) {
 867                 if(!(reason = errinf_to_str(&m->s)))
 868                         rcode = LDNS_RCODE_SERVFAIL;
 869         }
 870         /* send the reply */
 871         if(rcode) {
 872                 if(rcode == LDNS_RCODE_SERVFAIL) {
 873                         if(!inplace_cb_reply_servfail_call(m->s.env, &m->s.qinfo, &m->s,
 874                                 rep, rcode, &r->edns, m->s.region))
 875                                         r->edns.opt_list = NULL;
 876                 } else {
 877                         if(!inplace_cb_reply_call(m->s.env, &m->s.qinfo, &m->s, rep, rcode,
 878                                 &r->edns, m->s.region))
 879                                         r->edns.opt_list = NULL;
 880                 }
 881                 fptr_ok(fptr_whitelist_mesh_cb(r->cb));
 882                 (*r->cb)(r->cb_arg, rcode, r->buf, sec_status_unchecked, NULL);
 883         } else {
 884                 size_t udp_size = r->edns.udp_size;
 885                 sldns_buffer_clear(r->buf);
 886                 r->edns.edns_version = EDNS_ADVERTISED_VERSION;
 887                 r->edns.udp_size = EDNS_ADVERTISED_SIZE;
 888                 r->edns.ext_rcode = 0;
 889                 r->edns.bits &= EDNS_DO;
 890
 891                 if(!inplace_cb_reply_call(m->s.env, &m->s.qinfo, &m->s, rep,
 892                         LDNS_RCODE_NOERROR, &r->edns, m->s.region) ||
 893                         !reply_info_answer_encode(&m->s.qinfo, rep, r->qid,
 894                         r->qflags, r->buf, 0, 1,
 895                         m->s.env->scratch, udp_size, &r->edns,
 896                         (int)(r->edns.bits & EDNS_DO), secure))
 897                 {
 898                         fptr_ok(fptr_whitelist_mesh_cb(r->cb));
 899                         (*r->cb)(r->cb_arg, LDNS_RCODE_SERVFAIL, r->buf,
 900                                 sec_status_unchecked, NULL);
 901                 } else {
 902                         fptr_ok(fptr_whitelist_mesh_cb(r->cb));
 903                         (*r->cb)(r->cb_arg, LDNS_RCODE_NOERROR, r->buf,
 904                                 rep->security, reason);
 905                 }
 906         }
 907         free(reason);
 908         m->s.env->mesh->num_reply_addrs--;
 909 }
 910
 911 /**
 912  * Send reply to mesh reply entry
 913  * @param m: mesh state to send it for.
 914  * @param rcode: if not 0, error code.
 915  * @param rep: reply to send (or NULL if rcode is set).
 916  * @param r: reply entry
 917  * @param prev: previous reply, already has its answer encoded in buffer.
 918  */
 919 static void
 920 mesh_send_reply(struct mesh_state* m, int rcode, struct reply_info* rep,
 921         struct mesh_reply* r, struct mesh_reply* prev)
 922 {
 923         struct timeval end_time;
 924         struct timeval duration;
 925         int secure;
 926         /* Copy the client's EDNS for later restore, to make sure the edns
 927          * compare is with the correct edns options. */
 928         struct edns_data edns_bak = r->edns;
 929         /* examine security status */
 930         if(m->s.env->need_to_validate && (!(r->qflags&BIT_CD) ||
 931                 m->s.env->cfg->ignore_cd) && rep &&
 932                 rep->security <= sec_status_bogus) {
 933                 rcode = LDNS_RCODE_SERVFAIL;
 934                 if(m->s.env->cfg->stat_extended)
 935                         m->s.env->mesh->ans_bogus++;
 936         }
 937         if(rep && rep->security == sec_status_secure)
 938                 secure = 1;
 939         else    secure = 0;
 940         if(!rep && rcode == LDNS_RCODE_NOERROR)
 941                 rcode = LDNS_RCODE_SERVFAIL;
 942         /* send the reply */
 943         /* We don't reuse the encoded answer if either the previous or current
 944          * response has a local alias.  We could compare the alias records
 945          * and still reuse the previous answer if they are the same, but that
 946          * would be complicated and error prone for the relatively minor case.
 947          * So we err on the side of safety. */
 948         if(prev && prev->qflags == r->qflags &&
 949                 !prev->local_alias && !r->local_alias &&
 950                 prev->edns.edns_present == r->edns.edns_present &&
 951                 prev->edns.bits == r->edns.bits &&
 952                 prev->edns.udp_size == r->edns.udp_size &&
 953                 edns_opt_list_compare(prev->edns.opt_list, r->edns.opt_list)
 954                 == 0) {
 955                 /* if the previous reply is identical to this one, fix ID */
 956                 if(prev->query_reply.c->buffer != r->query_reply.c->buffer)
 957                         sldns_buffer_copy(r->query_reply.c->buffer,
 958                                 prev->query_reply.c->buffer);
 959                 sldns_buffer_write_at(r->query_reply.c->buffer, 0,
 960                         &r->qid, sizeof(uint16_t));
 961                 sldns_buffer_write_at(r->query_reply.c->buffer, 12,
 962                         r->qname, m->s.qinfo.qname_len);
 963                 comm_point_send_reply(&r->query_reply);
 964         } else if(rcode) {
 965                 m->s.qinfo.qname = r->qname;
 966                 m->s.qinfo.local_alias = r->local_alias;
 967                 if(rcode == LDNS_RCODE_SERVFAIL) {
 968                         if(!inplace_cb_reply_servfail_call(m->s.env, &m->s.qinfo, &m->s,
 969                                 rep, rcode, &r->edns, m->s.region))
 970                                         r->edns.opt_list = NULL;
 971                 } else {
 972                         if(!inplace_cb_reply_call(m->s.env, &m->s.qinfo, &m->s, rep, rcode,
 973                                 &r->edns, m->s.region))
 974                                         r->edns.opt_list = NULL;
 975                 }
 976                 error_encode(r->query_reply.c->buffer, rcode, &m->s.qinfo,
 977                         r->qid, r->qflags, &r->edns);
 978                 comm_point_send_reply(&r->query_reply);
 979         } else {
 980                 size_t udp_size = r->edns.udp_size;
 981                 r->edns.edns_version = EDNS_ADVERTISED_VERSION;
 982                 r->edns.udp_size = EDNS_ADVERTISED_SIZE;
 983                 r->edns.ext_rcode = 0;
 984                 r->edns.bits &= EDNS_DO;
 985                 m->s.qinfo.qname = r->qname;
 986                 m->s.qinfo.local_alias = r->local_alias;
 987                 if(!inplace_cb_reply_call(m->s.env, &m->s.qinfo, &m->s, rep,
 988                         LDNS_RCODE_NOERROR, &r->edns, m->s.region) ||
 989                         !reply_info_answer_encode(&m->s.qinfo, rep, r->qid,
 990                         r->qflags, r->query_reply.c->buffer, 0, 1,
 991                         m->s.env->scratch, udp_size, &r->edns,
 992                         (int)(r->edns.bits & EDNS_DO), secure))
 993                 {
 994                         if(!inplace_cb_reply_servfail_call(m->s.env, &m->s.qinfo, &m->s,
 995                         rep, LDNS_RCODE_SERVFAIL, &r->edns, m->s.region))
 996                                 r->edns.opt_list = NULL;
 997                         error_encode(r->query_reply.c->buffer,
 998                                 LDNS_RCODE_SERVFAIL, &m->s.qinfo, r->qid,
 999                                 r->qflags, &r->edns);
1000                 }
1001                 r->edns = edns_bak;
1002                 comm_point_send_reply(&r->query_reply);
1003         }
1004         /* account */
1005         m->s.env->mesh->num_reply_addrs--;
1006         end_time = *m->s.env->now_tv;
1007         timeval_subtract(&duration, &end_time, &r->start_time);
1008         verbose(VERB_ALGO, "query took " ARG_LL "d.%6.6d sec",
1009                 (long long)duration.tv_sec, (int)duration.tv_usec);
1010         m->s.env->mesh->replies_sent++;
1011         timeval_add(&m->s.env->mesh->replies_sum_wait, &duration);
1012         timehist_insert(m->s.env->mesh->histogram, &duration);
1013         if(m->s.env->cfg->stat_extended) {
1014                 uint16_t rc = FLAGS_GET_RCODE(sldns_buffer_read_u16_at(r->
1015                         query_reply.c->buffer, 2));
1016                 if(secure) m->s.env->mesh->ans_secure++;
1017                 m->s.env->mesh->ans_rcode[ rc ] ++;
1018                 if(rc == 0 && LDNS_ANCOUNT(sldns_buffer_begin(r->
1019                         query_reply.c->buffer)) == 0)
1020                         m->s.env->mesh->ans_nodata++;
1021         }
1022 }
1023
1024 void mesh_query_done(struct mesh_state* mstate)
1025 {
1026         struct mesh_reply* r;
1027         struct mesh_reply* prev = NULL;
1028         struct mesh_cb* c;
1029         struct reply_info* rep = (mstate->s.return_msg?
1030                 mstate->s.return_msg->rep:NULL);
1031         for(r = mstate->reply_list; r; r = r->next) {
1032                 mesh_send_reply(mstate, mstate->s.return_rcode, rep, r, prev);
1033                 prev = r;
1034         }
1035         mstate->replies_sent = 1;
1036         for(c = mstate->cb_list; c; c = c->next) {
1037                 mesh_do_callback(mstate, mstate->s.return_rcode, rep, c);
1038         }
1039 }
1040
1041 void mesh_walk_supers(struct mesh_area* mesh, struct mesh_state* mstate)
1042 {
1043         struct mesh_state_ref* ref;
1044         RBTREE_FOR(ref, struct mesh_state_ref*, &mstate->super_set)
1045         {
1046                 /* make super runnable */
1047                 (void)rbtree_insert(&mesh->run, &ref->s->run_node);
1048                 /* callback the function to inform super of result */
1049                 fptr_ok(fptr_whitelist_mod_inform_super(
1050                         mesh->mods.mod[ref->s->s.curmod]->inform_super));
1051                 (*mesh->mods.mod[ref->s->s.curmod]->inform_super)(&mstate->s,
1052                         ref->s->s.curmod, &ref->s->s);
1053         }
1054 }
1055
1056 struct mesh_state* mesh_area_find(struct mesh_area* mesh,
1057         struct query_info* qinfo, uint16_t qflags, int prime, int valrec)
1058 {
1059         struct mesh_state key;
1060         struct mesh_state* result;
1061
1062         key.node.key = &key;
1063         key.s.is_priming = prime;
1064         key.s.is_valrec = valrec;
1065         key.s.qinfo = *qinfo;
1066         key.s.query_flags = qflags;
1067         /* We are searching for a similar mesh state when we DO want to
1068          * aggregate the state. Thus unique is set to NULL. (default when we
1069          * desire aggregation).*/
1070         key.unique = NULL;
1071
1072         result = (struct mesh_state*)rbtree_search(&mesh->all, &key);
1073         return result;
1074 }
1075
1076 int mesh_state_add_cb(struct mesh_state* s, struct edns_data* edns,
1077         sldns_buffer* buf, mesh_cb_func_t cb, void* cb_arg,
1078         uint16_t qid, uint16_t qflags)
1079 {
1080         struct mesh_cb* r = regional_alloc(s->s.region,
1081                 sizeof(struct mesh_cb));
1082         if(!r)
1083                 return 0;
1084         r->buf = buf;
1085         log_assert(fptr_whitelist_mesh_cb(cb)); /* early failure ifmissing*/
1086         r->cb = cb;
1087         r->cb_arg = cb_arg;
1088         r->edns = *edns;
1089         if(edns->opt_list) {
1090                 r->edns.opt_list = edns_opt_copy_region(edns->opt_list,
1091                         s->s.region);
1092                 if(!r->edns.opt_list)
1093                         return 0;
1094         }
1095         r->qid = qid;
1096         r->qflags = qflags;
1097         r->next = s->cb_list;
1098         s->cb_list = r;
1099         return 1;
1100
1101 }
1102
1103 int mesh_state_add_reply(struct mesh_state* s, struct edns_data* edns,
1104         struct comm_reply* rep, uint16_t qid, uint16_t qflags,
1105         const struct query_info* qinfo)
1106 {
1107         struct mesh_reply* r = regional_alloc(s->s.region,
1108                 sizeof(struct mesh_reply));
1109         if(!r)
1110                 return 0;
1111         r->query_reply = *rep;
1112         r->edns = *edns;
1113         if(edns->opt_list) {
1114                 r->edns.opt_list = edns_opt_copy_region(edns->opt_list,
1115                         s->s.region);
1116                 if(!r->edns.opt_list)
1117                         return 0;
1118         }
1119         r->qid = qid;
1120         r->qflags = qflags;
1121         r->start_time = *s->s.env->now_tv;
1122         r->next = s->reply_list;
1123         r->qname = regional_alloc_init(s->s.region, qinfo->qname,
1124                 s->s.qinfo.qname_len);
1125         if(!r->qname)
1126                 return 0;
1127
1128         /* Data related to local alias stored in 'qinfo' (if any) is ephemeral
1129          * and can be different for different original queries (even if the
1130          * replaced query name is the same).  So we need to make a deep copy
1131          * and store the copy for each reply info. */
1132         if(qinfo->local_alias) {
1133                 struct packed_rrset_data* d;
1134                 struct packed_rrset_data* dsrc;
1135                 r->local_alias = regional_alloc_zero(s->s.region,
1136                         sizeof(*qinfo->local_alias));
1137                 if(!r->local_alias)
1138                         return 0;
1139                 r->local_alias->rrset = regional_alloc_init(s->s.region,
1140                         qinfo->local_alias->rrset,
1141                         sizeof(*qinfo->local_alias->rrset));
1142                 if(!r->local_alias->rrset)
1143                         return 0;
1144                 dsrc = qinfo->local_alias->rrset->entry.data;
1145
1146                 /* In the current implementation, a local alias must be
1147                  * a single CNAME RR (see worker_handle_request()). */
1148                 log_assert(!qinfo->local_alias->next && dsrc->count == 1 &&
1149                         qinfo->local_alias->rrset->rk.type ==
1150                         htons(LDNS_RR_TYPE_CNAME));
1151                 /* Technically, we should make a local copy for the owner
1152                  * name of the RRset, but in the case of the first (and
1153                  * currently only) local alias RRset, the owner name should
1154                  * point to the qname of the corresponding query, which should
1155                  * be valid throughout the lifetime of this mesh_reply.  So
1156                  * we can skip copying. */
1157                 log_assert(qinfo->local_alias->rrset->rk.dname ==
1158                         sldns_buffer_at(rep->c->buffer, LDNS_HEADER_SIZE));
1159
1160                 d = regional_alloc_init(s->s.region, dsrc,
1161                         sizeof(struct packed_rrset_data)
1162                         + sizeof(size_t) + sizeof(uint8_t*) + sizeof(time_t));
1163                 if(!d)
1164                         return 0;
1165                 r->local_alias->rrset->entry.data = d;
1166                 d->rr_len = (size_t*)((uint8_t*)d +
1167                         sizeof(struct packed_rrset_data));
1168                 d->rr_data = (uint8_t**)&(d->rr_len[1]);
1169                 d->rr_ttl = (time_t*)&(d->rr_data[1]);
1170                 d->rr_len[0] = dsrc->rr_len[0];
1171                 d->rr_ttl[0] = dsrc->rr_ttl[0];
1172                 d->rr_data[0] = regional_alloc_init(s->s.region,
1173                         dsrc->rr_data[0], d->rr_len[0]);
1174                 if(!d->rr_data[0])
1175                         return 0;
1176         } else
1177                 r->local_alias = NULL;
1178
1179         s->reply_list = r;
1180         return 1;
1181 }
1182
1183 /**
1184  * Continue processing the mesh state at another module.
1185  * Handles module to modules tranfer of control.
1186  * Handles module finished.
1187  * @param mesh: the mesh area.
1188  * @param mstate: currently active mesh state.
1189  *      Deleted if finished, calls _done and _supers to
1190  *      send replies to clients and inform other mesh states.
1191  *      This in turn may create additional runnable mesh states.
1192  * @param s: state at which the current module exited.
1193  * @param ev: the event sent to the module.
1194  *      returned is the event to send to the next module.
1195  * @return true if continue processing at the new module.
1196  *      false if not continued processing is needed.
1197  */
1198 static int
1199 mesh_continue(struct mesh_area* mesh, struct mesh_state* mstate,
1200         enum module_ext_state s, enum module_ev* ev)
1201 {
1202         mstate->num_activated++;
1203         if(mstate->num_activated > MESH_MAX_ACTIVATION) {
1204                 /* module is looping. Stop it. */
1205                 log_err("internal error: looping module stopped");
1206                 log_query_info(VERB_QUERY, "pass error for qstate",
1207                         &mstate->s.qinfo);
1208                 s = module_error;
1209         }
1210         if(s == module_wait_module || s == module_restart_next) {
1211                 /* start next module */
1212                 mstate->s.curmod++;
1213                 if(mesh->mods.num == mstate->s.curmod) {
1214                         log_err("Cannot pass to next module; at last module");
1215                         log_query_info(VERB_QUERY, "pass error for qstate",
1216                                 &mstate->s.qinfo);
1217                         mstate->s.curmod--;
1218                         return mesh_continue(mesh, mstate, module_error, ev);
1219                 }
1220                 if(s == module_restart_next) {
1221                         fptr_ok(fptr_whitelist_mod_clear(
1222                                 mesh->mods.mod[mstate->s.curmod]->clear));
1223                         (*mesh->mods.mod[mstate->s.curmod]->clear)
1224                                 (&mstate->s, mstate->s.curmod);
1225                         mstate->s.minfo[mstate->s.curmod] = NULL;
1226                 }
1227                 *ev = module_event_pass;
1228                 return 1;
1229         }
1230         if(s == module_wait_subquery && mstate->sub_set.count == 0) {
1231                 log_err("module cannot wait for subquery, subquery list empty");
1232                 log_query_info(VERB_QUERY, "pass error for qstate",
1233                         &mstate->s.qinfo);
1234                 s = module_error;
1235         }
1236         if(s == module_error && mstate->s.return_rcode == LDNS_RCODE_NOERROR) {
1237                 /* error is bad, handle pass back up below */
1238                 mstate->s.return_rcode = LDNS_RCODE_SERVFAIL;
1239         }
1240         if(s == module_error || s == module_finished) {
1241                 if(mstate->s.curmod == 0) {
1242                         mesh_query_done(mstate);
1243                         mesh_walk_supers(mesh, mstate);
1244                         mesh_state_delete(&mstate->s);
1245                         return 0;
1246                 }
1247                 /* pass along the locus of control */
1248                 mstate->s.curmod --;
1249                 *ev = module_event_moddone;
1250                 return 1;
1251         }
1252         return 0;
1253 }
1254
1255 void mesh_run(struct mesh_area* mesh, struct mesh_state* mstate,
1256         enum module_ev ev, struct outbound_entry* e)
1257 {
1258         enum module_ext_state s;
1259         verbose(VERB_ALGO, "mesh_run: start");
1260         while(mstate) {
1261                 /* run the module */
1262                 fptr_ok(fptr_whitelist_mod_operate(
1263                         mesh->mods.mod[mstate->s.curmod]->operate));
1264                 (*mesh->mods.mod[mstate->s.curmod]->operate)
1265                         (&mstate->s, ev, mstate->s.curmod, e);
1266
1267                 /* examine results */
1268                 mstate->s.reply = NULL;
1269                 regional_free_all(mstate->s.env->scratch);
1270                 s = mstate->s.ext_state[mstate->s.curmod];
1271                 verbose(VERB_ALGO, "mesh_run: %s module exit state is %s",
1272                         mesh->mods.mod[mstate->s.curmod]->name, strextstate(s));
1273                 e = NULL;
1274                 if(mesh_continue(mesh, mstate, s, &ev))
1275                         continue;
1276
1277                 /* run more modules */
1278                 ev = module_event_pass;
1279                 if(mesh->run.count > 0) {
1280                         /* pop random element off the runnable tree */
1281                         mstate = (struct mesh_state*)mesh->run.root->key;
1282                         (void)rbtree_delete(&mesh->run, mstate);
1283                 } else mstate = NULL;
1284         }
1285         if(verbosity >= VERB_ALGO) {
1286                 mesh_stats(mesh, "mesh_run: end");
1287                 mesh_log_list(mesh);
1288         }
1289 }
1290
1291 void
1292 mesh_log_list(struct mesh_area* mesh)
1293 {
1294         char buf[30];
1295         struct mesh_state* m;
1296         int num = 0;
1297         RBTREE_FOR(m, struct mesh_state*, &mesh->all) {
1298                 snprintf(buf, sizeof(buf), "%d%s%s%s%s%s%s mod%d %s%s",
1299                         num++, (m->s.is_priming)?"p":"",  /* prime */
1300                         (m->s.is_valrec)?"v":"",  /* prime */
1301                         (m->s.query_flags&BIT_RD)?"RD":"",
1302                         (m->s.query_flags&BIT_CD)?"CD":"",
1303                         (m->super_set.count==0)?"d":"", /* detached */
1304                         (m->sub_set.count!=0)?"c":"",  /* children */
1305                         m->s.curmod, (m->reply_list)?"rep":"", /*hasreply*/
1306                         (m->cb_list)?"cb":"" /* callbacks */
1307                         );
1308                 log_query_info(VERB_ALGO, buf, &m->s.qinfo);
1309         }
1310 }
1311
1312 void
1313 mesh_stats(struct mesh_area* mesh, const char* str)
1314 {
1315         verbose(VERB_DETAIL, "%s %u recursion states (%u with reply, "
1316                 "%u detached), %u waiting replies, %u recursion replies "
1317                 "sent, %d replies dropped, %d states jostled out",
1318                 str, (unsigned)mesh->all.count,
1319                 (unsigned)mesh->num_reply_states,
1320                 (unsigned)mesh->num_detached_states,
1321                 (unsigned)mesh->num_reply_addrs,
1322                 (unsigned)mesh->replies_sent,
1323                 (unsigned)mesh->stats_dropped,
1324                 (unsigned)mesh->stats_jostled);
1325         if(mesh->replies_sent > 0) {
1326                 struct timeval avg;
1327                 timeval_divide(&avg, &mesh->replies_sum_wait,
1328                         mesh->replies_sent);
1329                 log_info("average recursion processing time "
1330                         ARG_LL "d.%6.6d sec",
1331                         (long long)avg.tv_sec, (int)avg.tv_usec);
1332                 log_info("histogram of recursion processing times");
1333                 timehist_log(mesh->histogram, "recursions");
1334         }
1335 }
1336
1337 void
1338 mesh_stats_clear(struct mesh_area* mesh)
1339 {
1340         if(!mesh)
1341                 return;
1342         mesh->replies_sent = 0;
1343         mesh->replies_sum_wait.tv_sec = 0;
1344         mesh->replies_sum_wait.tv_usec = 0;
1345         mesh->stats_jostled = 0;
1346         mesh->stats_dropped = 0;
1347         timehist_clear(mesh->histogram);
1348         mesh->ans_secure = 0;
1349         mesh->ans_bogus = 0;
1350         memset(&mesh->ans_rcode[0], 0, sizeof(size_t)*16);
1351         mesh->ans_nodata = 0;
1352 }
1353
1354 size_t
1355 mesh_get_mem(struct mesh_area* mesh)
1356 {
1357         struct mesh_state* m;
1358         size_t s = sizeof(*mesh) + sizeof(struct timehist) +
1359                 sizeof(struct th_buck)*mesh->histogram->num +
1360                 sizeof(sldns_buffer) + sldns_buffer_capacity(mesh->qbuf_bak);
1361         RBTREE_FOR(m, struct mesh_state*, &mesh->all) {
1362                 /* all, including m itself allocated in qstate region */
1363                 s += regional_get_mem(m->s.region);
1364         }
1365         return s;
1366 }
1367
1368 int
1369 mesh_detect_cycle(struct module_qstate* qstate, struct query_info* qinfo,
1370         uint16_t flags, int prime, int valrec)
1371 {
1372         struct mesh_area* mesh = qstate->env->mesh;
1373         struct mesh_state* dep_m = NULL;
1374         if(!mesh_state_is_unique(qstate->mesh_info))
1375                 dep_m = mesh_area_find(mesh, qinfo, flags, prime, valrec);
1376         return mesh_detect_cycle_found(qstate, dep_m);
1377 }
1378
1379 void mesh_list_insert(struct mesh_state* m, struct mesh_state** fp,
1380         struct mesh_state** lp)
1381 {
1382         /* insert as last element */
1383         m->prev = *lp;
1384         m->next = NULL;
1385         if(*lp)
1386                 (*lp)->next = m;
1387         else    *fp = m;
1388         *lp = m;
1389 }
1390
1391 void mesh_list_remove(struct mesh_state* m, struct mesh_state** fp,
1392         struct mesh_state** lp)
1393 {
1394         if(m->next)
1395                 m->next->prev = m->prev;
1396         else    *lp = m->prev;
1397         if(m->prev)
1398                 m->prev->next = m->next;
1399         else    *fp = m->next;
1400 }