contrib/unbound/services/mesh.c

   1 /*
   2  * services/mesh.c - deal with mesh of query states and handle events for that.
   3  *
   4  * Copyright (c) 2007, NLnet Labs. All rights reserved.
   5  *
   6  * This software is open source.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  *
  12  * Redistributions of source code must retain the above copyright notice,
  13  * this list of conditions and the following disclaimer.
  14  *
  15  * Redistributions in binary form must reproduce the above copyright notice,
  16  * this list of conditions and the following disclaimer in the documentation
  17  * and/or other materials provided with the distribution.
  18  *
  19  * Neither the name of the NLNET LABS nor the names of its contributors may
  20  * be used to endorse or promote products derived from this software without
  21  * specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  24  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  25  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  26  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  27  * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  28  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
  29  * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  30  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  31  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  32  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  33  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  34  */
  35
  36 /**
  37  * \file
  38  *
  39  * This file contains functions to assist in dealing with a mesh of
  40  * query states. This mesh is supposed to be thread-specific.
  41  * It consists of query states (per qname, qtype, qclass) and connections
  42  * between query states and the super and subquery states, and replies to
  43  * send back to clients.
  44  */
  45 #include "config.h"
  46 #include "services/mesh.h"
  47 #include "services/outbound_list.h"
  48 #include "services/cache/dns.h"
  49 #include "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 #include "respip/respip.h"
  63
  64 /** subtract timers and the values do not overflow or become negative */
  65 static void
  66 timeval_subtract(struct timeval* d, const struct timeval* end, const struct timeval* start)
  67 {
  68 #ifndef S_SPLINT_S
  69         time_t end_usec = end->tv_usec;
  70         d->tv_sec = end->tv_sec - start->tv_sec;
  71         if(end_usec < start->tv_usec) {
  72                 end_usec += 1000000;
  73                 d->tv_sec--;
  74         }
  75         d->tv_usec = end_usec - start->tv_usec;
  76 #endif
  77 }
  78
  79 /** add timers and the values do not overflow or become negative */
  80 static void
  81 timeval_add(struct timeval* d, const struct timeval* add)
  82 {
  83 #ifndef S_SPLINT_S
  84         d->tv_sec += add->tv_sec;
  85         d->tv_usec += add->tv_usec;
  86         if(d->tv_usec > 1000000 ) {
  87                 d->tv_usec -= 1000000;
  88                 d->tv_sec++;
  89         }
  90 #endif
  91 }
  92
  93 /** divide sum of timers to get average */
  94 static void
  95 timeval_divide(struct timeval* avg, const struct timeval* sum, size_t d)
  96 {
  97 #ifndef S_SPLINT_S
  98         size_t leftover;
  99         if(d == 0) {
 100                 avg->tv_sec = 0;
 101                 avg->tv_usec = 0;
 102                 return;
 103         }
 104         avg->tv_sec = sum->tv_sec / d;
 105         avg->tv_usec = sum->tv_usec / d;
 106         /* handle fraction from seconds divide */
 107         leftover = sum->tv_sec - avg->tv_sec*d;
 108         avg->tv_usec += (leftover*1000000)/d;
 109 #endif
 110 }
 111
 112 /** histogram compare of time values */
 113 static int
 114 timeval_smaller(const struct timeval* x, const struct timeval* y)
 115 {
 116 #ifndef S_SPLINT_S
 117         if(x->tv_sec < y->tv_sec)
 118                 return 1;
 119         else if(x->tv_sec == y->tv_sec) {
 120                 if(x->tv_usec <= y->tv_usec)
 121                         return 1;
 122                 else    return 0;
 123         }
 124         else    return 0;
 125 #endif
 126 }
 127
 128 /*
 129  * Compare two response-ip client info entries for the purpose of mesh state
 130  * compare.  It returns 0 if ci_a and ci_b are considered equal; otherwise
 131  * 1 or -1 (they mean 'ci_a is larger/smaller than ci_b', respectively, but
 132  * in practice it should be only used to mean they are different).
 133  * We cannot share the mesh state for two queries if different response-ip
 134  * actions can apply in the end, even if those queries are otherwise identical.
 135  * For this purpose we compare tag lists and tag action lists; they should be
 136  * identical to share the same state.
 137  * For tag data, we don't look into the data content, as it can be
 138  * expensive; unless tag data are not defined for both or they point to the
 139  * exact same data in memory (i.e., they come from the same ACL entry), we
 140  * consider these data different.
 141  * Likewise, if the client info is associated with views, we don't look into
 142  * the views.  They are considered different unless they are exactly the same
 143  * even if the views only differ in the names.
 144  */
 145 static int
 146 client_info_compare(const struct respip_client_info* ci_a,
 147         const struct respip_client_info* ci_b)
 148 {
 149         int cmp;
 150
 151         if(!ci_a && !ci_b)
 152                 return 0;
 153         if(ci_a && !ci_b)
 154                 return -1;
 155         if(!ci_a && ci_b)
 156                 return 1;
 157         if(ci_a->taglen != ci_b->taglen)
 158                 return (ci_a->taglen < ci_b->taglen) ? -1 : 1;
 159         cmp = memcmp(ci_a->taglist, ci_b->taglist, ci_a->taglen);
 160         if(cmp != 0)
 161                 return cmp;
 162         if(ci_a->tag_actions_size != ci_b->tag_actions_size)
 163                 return (ci_a->tag_actions_size < ci_b->tag_actions_size) ?
 164                         -1 : 1;
 165         cmp = memcmp(ci_a->tag_actions, ci_b->tag_actions,
 166                 ci_a->tag_actions_size);
 167         if(cmp != 0)
 168                 return cmp;
 169         if(ci_a->tag_datas != ci_b->tag_datas)
 170                 return ci_a->tag_datas < ci_b->tag_datas ? -1 : 1;
 171         if(ci_a->view != ci_b->view)
 172                 return ci_a->view < ci_b->view ? -1 : 1;
 173         /* For the unbound daemon these should be non-NULL and identical,
 174          * but we check that just in case. */
 175         if(ci_a->respip_set != ci_b->respip_set)
 176                 return ci_a->respip_set < ci_b->respip_set ? -1 : 1;
 177         return 0;
 178 }
 179
 180 int
 181 mesh_state_compare(const void* ap, const void* bp)
 182 {
 183         struct mesh_state* a = (struct mesh_state*)ap;
 184         struct mesh_state* b = (struct mesh_state*)bp;
 185         int cmp;
 186
 187         if(a->unique < b->unique)
 188                 return -1;
 189         if(a->unique > b->unique)
 190                 return 1;
 191
 192         if(a->s.is_priming && !b->s.is_priming)
 193                 return -1;
 194         if(!a->s.is_priming && b->s.is_priming)
 195                 return 1;
 196
 197         if(a->s.is_valrec && !b->s.is_valrec)
 198                 return -1;
 199         if(!a->s.is_valrec && b->s.is_valrec)
 200                 return 1;
 201
 202         if((a->s.query_flags&BIT_RD) && !(b->s.query_flags&BIT_RD))
 203                 return -1;
 204         if(!(a->s.query_flags&BIT_RD) && (b->s.query_flags&BIT_RD))
 205                 return 1;
 206
 207         if((a->s.query_flags&BIT_CD) && !(b->s.query_flags&BIT_CD))
 208                 return -1;
 209         if(!(a->s.query_flags&BIT_CD) && (b->s.query_flags&BIT_CD))
 210                 return 1;
 211
 212         cmp = query_info_compare(&a->s.qinfo, &b->s.qinfo);
 213         if(cmp != 0)
 214                 return cmp;
 215         return client_info_compare(a->s.client_info, b->s.client_info);
 216 }
 217
 218 int
 219 mesh_state_ref_compare(const void* ap, const void* bp)
 220 {
 221         struct mesh_state_ref* a = (struct mesh_state_ref*)ap;
 222         struct mesh_state_ref* b = (struct mesh_state_ref*)bp;
 223         return mesh_state_compare(a->s, b->s);
 224 }
 225
 226 struct mesh_area*
 227 mesh_create(struct module_stack* stack, struct module_env* env)
 228 {
 229         struct mesh_area* mesh = calloc(1, sizeof(struct mesh_area));
 230         if(!mesh) {
 231                 log_err("mesh area alloc: out of memory");
 232                 return NULL;
 233         }
 234         mesh->histogram = timehist_setup();
 235         mesh->qbuf_bak = sldns_buffer_new(env->cfg->msg_buffer_size);
 236         if(!mesh->histogram || !mesh->qbuf_bak) {
 237                 free(mesh);
 238                 log_err("mesh area alloc: out of memory");
 239                 return NULL;
 240         }
 241         mesh->mods = *stack;
 242         mesh->env = env;
 243         rbtree_init(&mesh->run, &mesh_state_compare);
 244         rbtree_init(&mesh->all, &mesh_state_compare);
 245         mesh->num_reply_addrs = 0;
 246         mesh->num_reply_states = 0;
 247         mesh->num_detached_states = 0;
 248         mesh->num_forever_states = 0;
 249         mesh->stats_jostled = 0;
 250         mesh->stats_dropped = 0;
 251         mesh->max_reply_states = env->cfg->num_queries_per_thread;
 252         mesh->max_forever_states = (mesh->max_reply_states+1)/2;
 253 #ifndef S_SPLINT_S
 254         mesh->jostle_max.tv_sec = (time_t)(env->cfg->jostle_time / 1000);
 255         mesh->jostle_max.tv_usec = (time_t)((env->cfg->jostle_time % 1000)
 256                 *1000);
 257 #endif
 258         return mesh;
 259 }
 260
 261 /** help mesh delete delete mesh states */
 262 static void
 263 mesh_delete_helper(rbnode_type* n)
 264 {
 265         struct mesh_state* mstate = (struct mesh_state*)n->key;
 266         /* perform a full delete, not only 'cleanup' routine,
 267          * because other callbacks expect a clean state in the mesh.
 268          * For 're-entrant' calls */
 269         mesh_state_delete(&mstate->s);
 270         /* but because these delete the items from the tree, postorder
 271          * traversal and rbtree rebalancing do not work together */
 272 }
 273
 274 void
 275 mesh_delete(struct mesh_area* mesh)
 276 {
 277         if(!mesh)
 278                 return;
 279         /* free all query states */
 280         while(mesh->all.count)
 281                 mesh_delete_helper(mesh->all.root);
 282         timehist_delete(mesh->histogram);
 283         sldns_buffer_free(mesh->qbuf_bak);
 284         free(mesh);
 285 }
 286
 287 void
 288 mesh_delete_all(struct mesh_area* mesh)
 289 {
 290         /* free all query states */
 291         while(mesh->all.count)
 292                 mesh_delete_helper(mesh->all.root);
 293         mesh->stats_dropped += mesh->num_reply_addrs;
 294         /* clear mesh area references */
 295         rbtree_init(&mesh->run, &mesh_state_compare);
 296         rbtree_init(&mesh->all, &mesh_state_compare);
 297         mesh->num_reply_addrs = 0;
 298         mesh->num_reply_states = 0;
 299         mesh->num_detached_states = 0;
 300         mesh->num_forever_states = 0;
 301         mesh->forever_first = NULL;
 302         mesh->forever_last = NULL;
 303         mesh->jostle_first = NULL;
 304         mesh->jostle_last = NULL;
 305 }
 306
 307 int mesh_make_new_space(struct mesh_area* mesh, sldns_buffer* qbuf)
 308 {
 309         struct mesh_state* m = mesh->jostle_first;
 310         /* free space is available */
 311         if(mesh->num_reply_states < mesh->max_reply_states)
 312                 return 1;
 313         /* try to kick out a jostle-list item */
 314         if(m && m->reply_list && m->list_select == mesh_jostle_list) {
 315                 /* how old is it? */
 316                 struct timeval age;
 317                 timeval_subtract(&age, mesh->env->now_tv,
 318                         &m->reply_list->start_time);
 319                 if(timeval_smaller(&mesh->jostle_max, &age)) {
 320                         /* its a goner */
 321                         log_nametypeclass(VERB_ALGO, "query jostled out to "
 322                                 "make space for a new one",
 323                                 m->s.qinfo.qname, m->s.qinfo.qtype,
 324                                 m->s.qinfo.qclass);
 325                         /* backup the query */
 326                         if(qbuf) sldns_buffer_copy(mesh->qbuf_bak, qbuf);
 327                         /* notify supers */
 328                         if(m->super_set.count > 0) {
 329                                 verbose(VERB_ALGO, "notify supers of failure");
 330                                 m->s.return_msg = NULL;
 331                                 m->s.return_rcode = LDNS_RCODE_SERVFAIL;
 332                                 mesh_walk_supers(mesh, m);
 333                         }
 334                         mesh->stats_jostled ++;
 335                         mesh_state_delete(&m->s);
 336                         /* restore the query - note that the qinfo ptr to
 337                          * the querybuffer is then correct again. */
 338                         if(qbuf) sldns_buffer_copy(qbuf, mesh->qbuf_bak);
 339                         return 1;
 340                 }
 341         }
 342         /* no space for new item */
 343         return 0;
 344 }
 345
 346 void mesh_new_client(struct mesh_area* mesh, struct query_info* qinfo,
 347         struct respip_client_info* cinfo, uint16_t qflags,
 348         struct edns_data* edns, struct comm_reply* rep, uint16_t qid)
 349 {
 350         struct mesh_state* s = NULL;
 351         int unique = unique_mesh_state(edns->opt_list, mesh->env);
 352         int was_detached = 0;
 353         int was_noreply = 0;
 354         int added = 0;
 355         if(!unique)
 356                 s = mesh_area_find(mesh, cinfo, qinfo, qflags&(BIT_RD|BIT_CD), 0, 0);
 357         /* does this create a new reply state? */
 358         if(!s || s->list_select == mesh_no_list) {
 359                 if(!mesh_make_new_space(mesh, rep->c->buffer)) {
 360                         verbose(VERB_ALGO, "Too many queries. dropping "
 361                                 "incoming query.");
 362                         comm_point_drop_reply(rep);
 363                         mesh->stats_dropped ++;
 364                         return;
 365                 }
 366                 /* for this new reply state, the reply address is free,
 367                  * so the limit of reply addresses does not stop reply states*/
 368         } else {
 369                 /* protect our memory usage from storing reply addresses */
 370                 if(mesh->num_reply_addrs > mesh->max_reply_states*16) {
 371                         verbose(VERB_ALGO, "Too many requests queued. "
 372                                 "dropping incoming query.");
 373                         mesh->stats_dropped++;
 374                         comm_point_drop_reply(rep);
 375                         return;
 376                 }
 377         }
 378         /* see if it already exists, if not, create one */
 379         if(!s) {
 380 #ifdef UNBOUND_DEBUG
 381                 struct rbnode_type* n;
 382 #endif
 383                 s = mesh_state_create(mesh->env, qinfo, cinfo,
 384                         qflags&(BIT_RD|BIT_CD), 0, 0);
 385                 if(!s) {
 386                         log_err("mesh_state_create: out of memory; SERVFAIL");
 387                         if(!inplace_cb_reply_servfail_call(mesh->env, qinfo, NULL, NULL,
 388                                 LDNS_RCODE_SERVFAIL, edns, mesh->env->scratch))
 389                                         edns->opt_list = NULL;
 390                         error_encode(rep->c->buffer, LDNS_RCODE_SERVFAIL,
 391                                 qinfo, qid, qflags, edns);
 392                         comm_point_send_reply(rep);
 393                         return;
 394                 }
 395                 if(unique)
 396                         mesh_state_make_unique(s);
 397                 /* copy the edns options we got from the front */
 398                 if(edns->opt_list) {
 399                         s->s.edns_opts_front_in = edns_opt_copy_region(edns->opt_list,
 400                                 s->s.region);
 401                         if(!s->s.edns_opts_front_in) {
 402                                 log_err("mesh_state_create: out of memory; SERVFAIL");
 403                                 if(!inplace_cb_reply_servfail_call(mesh->env, qinfo, NULL,
 404                                         NULL, LDNS_RCODE_SERVFAIL, edns, mesh->env->scratch))
 405                                                 edns->opt_list = NULL;
 406                                 error_encode(rep->c->buffer, LDNS_RCODE_SERVFAIL,
 407                                         qinfo, qid, qflags, edns);
 408                                 comm_point_send_reply(rep);
 409                                 return;
 410                         }
 411                 }
 412
 413 #ifdef UNBOUND_DEBUG
 414                 n =
 415 #else
 416                 (void)
 417 #endif
 418                 rbtree_insert(&mesh->all, &s->node);
 419                 log_assert(n != NULL);
 420                 /* set detached (it is now) */
 421                 mesh->num_detached_states++;
 422                 added = 1;
 423         }
 424         if(!s->reply_list && !s->cb_list && s->super_set.count == 0)
 425                 was_detached = 1;
 426         if(!s->reply_list && !s->cb_list)
 427                 was_noreply = 1;
 428         /* add reply to s */
 429         if(!mesh_state_add_reply(s, edns, rep, qid, qflags, qinfo)) {
 430                         log_err("mesh_new_client: out of memory; SERVFAIL");
 431                         if(!inplace_cb_reply_servfail_call(mesh->env, qinfo, &s->s,
 432                                 NULL, LDNS_RCODE_SERVFAIL, edns, mesh->env->scratch))
 433                                         edns->opt_list = NULL;
 434                         error_encode(rep->c->buffer, LDNS_RCODE_SERVFAIL,
 435                                 qinfo, qid, qflags, edns);
 436                         comm_point_send_reply(rep);
 437                         if(added)
 438                                 mesh_state_delete(&s->s);
 439                         return;
 440         }
 441         /* update statistics */
 442         if(was_detached) {
 443                 log_assert(mesh->num_detached_states > 0);
 444                 mesh->num_detached_states--;
 445         }
 446         if(was_noreply) {
 447                 mesh->num_reply_states ++;
 448         }
 449         mesh->num_reply_addrs++;
 450         if(s->list_select == mesh_no_list) {
 451                 /* move to either the forever or the jostle_list */
 452                 if(mesh->num_forever_states < mesh->max_forever_states) {
 453                         mesh->num_forever_states ++;
 454                         mesh_list_insert(s, &mesh->forever_first,
 455                                 &mesh->forever_last);
 456                         s->list_select = mesh_forever_list;
 457                 } else {
 458                         mesh_list_insert(s, &mesh->jostle_first,
 459                                 &mesh->jostle_last);
 460                         s->list_select = mesh_jostle_list;
 461                 }
 462         }
 463         if(added)
 464                 mesh_run(mesh, s, module_event_new, NULL);
 465 }
 466
 467 int
 468 mesh_new_callback(struct mesh_area* mesh, struct query_info* qinfo,
 469         uint16_t qflags, struct edns_data* edns, sldns_buffer* buf,
 470         uint16_t qid, mesh_cb_func_type cb, void* cb_arg)
 471 {
 472         struct mesh_state* s = NULL;
 473         int unique = unique_mesh_state(edns->opt_list, mesh->env);
 474         int was_detached = 0;
 475         int was_noreply = 0;
 476         int added = 0;
 477         if(!unique)
 478                 s = mesh_area_find(mesh, NULL, qinfo, qflags&(BIT_RD|BIT_CD), 0, 0);
 479
 480         /* there are no limits on the number of callbacks */
 481
 482         /* see if it already exists, if not, create one */
 483         if(!s) {
 484 #ifdef UNBOUND_DEBUG
 485                 struct rbnode_type* n;
 486 #endif
 487                 s = mesh_state_create(mesh->env, qinfo, NULL,
 488                         qflags&(BIT_RD|BIT_CD), 0, 0);
 489                 if(!s) {
 490                         return 0;
 491                 }
 492                 if(unique)
 493                         mesh_state_make_unique(s);
 494                 if(edns->opt_list) {
 495                         s->s.edns_opts_front_in = edns_opt_copy_region(edns->opt_list,
 496                                 s->s.region);
 497                         if(!s->s.edns_opts_front_in) {
 498                                 return 0;
 499                         }
 500                 }
 501 #ifdef UNBOUND_DEBUG
 502                 n =
 503 #else
 504                 (void)
 505 #endif
 506                 rbtree_insert(&mesh->all, &s->node);
 507                 log_assert(n != NULL);
 508                 /* set detached (it is now) */
 509                 mesh->num_detached_states++;
 510                 added = 1;
 511         }
 512         if(!s->reply_list && !s->cb_list && s->super_set.count == 0)
 513                 was_detached = 1;
 514         if(!s->reply_list && !s->cb_list)
 515                 was_noreply = 1;
 516         /* add reply to s */
 517         if(!mesh_state_add_cb(s, edns, buf, cb, cb_arg, qid, qflags)) {
 518                         if(added)
 519                                 mesh_state_delete(&s->s);
 520                         return 0;
 521         }
 522         /* update statistics */
 523         if(was_detached) {
 524                 log_assert(mesh->num_detached_states > 0);
 525                 mesh->num_detached_states--;
 526         }
 527         if(was_noreply) {
 528                 mesh->num_reply_states ++;
 529         }
 530         mesh->num_reply_addrs++;
 531         if(added)
 532                 mesh_run(mesh, s, module_event_new, NULL);
 533         return 1;
 534 }
 535
 536 static void mesh_schedule_prefetch(struct mesh_area* mesh,
 537         struct query_info* qinfo, uint16_t qflags, time_t leeway, int run);
 538
 539 void mesh_new_prefetch(struct mesh_area* mesh, struct query_info* qinfo,
 540         uint16_t qflags, time_t leeway)
 541 {
 542         mesh_schedule_prefetch(mesh, qinfo, qflags, leeway, 1);
 543 }
 544
 545 /* Internal backend routine of mesh_new_prefetch().  It takes one additional
 546  * parameter, 'run', which controls whether to run the prefetch state
 547  * immediately.  When this function is called internally 'run' could be
 548  * 0 (false), in which case the new state is only made runnable so it
 549  * will not be run recursively on top of the current state. */
 550 static void mesh_schedule_prefetch(struct mesh_area* mesh,
 551         struct query_info* qinfo, uint16_t qflags, time_t leeway, int run)
 552 {
 553         struct mesh_state* s = mesh_area_find(mesh, NULL, qinfo,
 554                 qflags&(BIT_RD|BIT_CD), 0, 0);
 555 #ifdef UNBOUND_DEBUG
 556         struct rbnode_type* n;
 557 #endif
 558         /* already exists, and for a different purpose perhaps.
 559          * if mesh_no_list, keep it that way. */
 560         if(s) {
 561                 /* make it ignore the cache from now on */
 562                 if(!s->s.blacklist)
 563                         sock_list_insert(&s->s.blacklist, NULL, 0, s->s.region);
 564                 if(s->s.prefetch_leeway < leeway)
 565                         s->s.prefetch_leeway = leeway;
 566                 return;
 567         }
 568         if(!mesh_make_new_space(mesh, NULL)) {
 569                 verbose(VERB_ALGO, "Too many queries. dropped prefetch.");
 570                 mesh->stats_dropped ++;
 571                 return;
 572         }
 573
 574         s = mesh_state_create(mesh->env, qinfo, NULL,
 575                 qflags&(BIT_RD|BIT_CD), 0, 0);
 576         if(!s) {
 577                 log_err("prefetch mesh_state_create: out of memory");
 578                 return;
 579         }
 580 #ifdef UNBOUND_DEBUG
 581         n =
 582 #else
 583         (void)
 584 #endif
 585         rbtree_insert(&mesh->all, &s->node);
 586         log_assert(n != NULL);
 587         /* set detached (it is now) */
 588         mesh->num_detached_states++;
 589         /* make it ignore the cache */
 590         sock_list_insert(&s->s.blacklist, NULL, 0, s->s.region);
 591         s->s.prefetch_leeway = leeway;
 592
 593         if(s->list_select == mesh_no_list) {
 594                 /* move to either the forever or the jostle_list */
 595                 if(mesh->num_forever_states < mesh->max_forever_states) {
 596                         mesh->num_forever_states ++;
 597                         mesh_list_insert(s, &mesh->forever_first,
 598                                 &mesh->forever_last);
 599                         s->list_select = mesh_forever_list;
 600                 } else {
 601                         mesh_list_insert(s, &mesh->jostle_first,
 602                                 &mesh->jostle_last);
 603                         s->list_select = mesh_jostle_list;
 604                 }
 605         }
 606
 607         if(!run) {
 608 #ifdef UNBOUND_DEBUG
 609                 n =
 610 #else
 611                 (void)
 612 #endif
 613                 rbtree_insert(&mesh->run, &s->run_node);
 614                 log_assert(n != NULL);
 615                 return;
 616         }
 617
 618         mesh_run(mesh, s, module_event_new, NULL);
 619 }
 620
 621 void mesh_report_reply(struct mesh_area* mesh, struct outbound_entry* e,
 622         struct comm_reply* reply, int what)
 623 {
 624         enum module_ev event = module_event_reply;
 625         e->qstate->reply = reply;
 626         if(what != NETEVENT_NOERROR) {
 627                 event = module_event_noreply;
 628                 if(what == NETEVENT_CAPSFAIL)
 629                         event = module_event_capsfail;
 630         }
 631         mesh_run(mesh, e->qstate->mesh_info, event, e);
 632 }
 633
 634 struct mesh_state*
 635 mesh_state_create(struct module_env* env, struct query_info* qinfo,
 636         struct respip_client_info* cinfo, uint16_t qflags, int prime,
 637         int valrec)
 638 {
 639         struct regional* region = alloc_reg_obtain(env->alloc);
 640         struct mesh_state* mstate;
 641         int i;
 642         if(!region)
 643                 return NULL;
 644         mstate = (struct mesh_state*)regional_alloc(region,
 645                 sizeof(struct mesh_state));
 646         if(!mstate) {
 647                 alloc_reg_release(env->alloc, region);
 648                 return NULL;
 649         }
 650         memset(mstate, 0, sizeof(*mstate));
 651         mstate->node = *RBTREE_NULL;
 652         mstate->run_node = *RBTREE_NULL;
 653         mstate->node.key = mstate;
 654         mstate->run_node.key = mstate;
 655         mstate->reply_list = NULL;
 656         mstate->list_select = mesh_no_list;
 657         mstate->replies_sent = 0;
 658         rbtree_init(&mstate->super_set, &mesh_state_ref_compare);
 659         rbtree_init(&mstate->sub_set, &mesh_state_ref_compare);
 660         mstate->num_activated = 0;
 661         mstate->unique = NULL;
 662         /* init module qstate */
 663         mstate->s.qinfo.qtype = qinfo->qtype;
 664         mstate->s.qinfo.qclass = qinfo->qclass;
 665         mstate->s.qinfo.local_alias = NULL;
 666         mstate->s.qinfo.qname_len = qinfo->qname_len;
 667         mstate->s.qinfo.qname = regional_alloc_init(region, qinfo->qname,
 668                 qinfo->qname_len);
 669         if(!mstate->s.qinfo.qname) {
 670                 alloc_reg_release(env->alloc, region);
 671                 return NULL;
 672         }
 673         if(cinfo) {
 674                 mstate->s.client_info = regional_alloc_init(region, cinfo,
 675                         sizeof(*cinfo));
 676                 if(!mstate->s.client_info) {
 677                         alloc_reg_release(env->alloc, region);
 678                         return NULL;
 679                 }
 680         }
 681         /* remove all weird bits from qflags */
 682         mstate->s.query_flags = (qflags & (BIT_RD|BIT_CD));
 683         mstate->s.is_priming = prime;
 684         mstate->s.is_valrec = valrec;
 685         mstate->s.reply = NULL;
 686         mstate->s.region = region;
 687         mstate->s.curmod = 0;
 688         mstate->s.return_msg = 0;
 689         mstate->s.return_rcode = LDNS_RCODE_NOERROR;
 690         mstate->s.env = env;
 691         mstate->s.mesh_info = mstate;
 692         mstate->s.prefetch_leeway = 0;
 693         mstate->s.no_cache_lookup = 0;
 694         mstate->s.no_cache_store = 0;
 695         mstate->s.need_refetch = 0;
 696
 697         /* init modules */
 698         for(i=0; i<env->mesh->mods.num; i++) {
 699                 mstate->s.minfo[i] = NULL;
 700                 mstate->s.ext_state[i] = module_state_initial;
 701         }
 702         /* init edns option lists */
 703         mstate->s.edns_opts_front_in = NULL;
 704         mstate->s.edns_opts_back_out = NULL;
 705         mstate->s.edns_opts_back_in = NULL;
 706         mstate->s.edns_opts_front_out = NULL;
 707
 708         return mstate;
 709 }
 710
 711 int
 712 mesh_state_is_unique(struct mesh_state* mstate)
 713 {
 714         return mstate->unique != NULL;
 715 }
 716
 717 void
 718 mesh_state_make_unique(struct mesh_state* mstate)
 719 {
 720         mstate->unique = mstate;
 721 }
 722
 723 void
 724 mesh_state_cleanup(struct mesh_state* mstate)
 725 {
 726         struct mesh_area* mesh;
 727         int i;
 728         if(!mstate)
 729                 return;
 730         mesh = mstate->s.env->mesh;
 731         /* drop unsent replies */
 732         if(!mstate->replies_sent) {
 733                 struct mesh_reply* rep;
 734                 struct mesh_cb* cb;
 735                 for(rep=mstate->reply_list; rep; rep=rep->next) {
 736                         comm_point_drop_reply(&rep->query_reply);
 737                         mesh->num_reply_addrs--;
 738                 }
 739                 while((cb = mstate->cb_list)!=NULL) {
 740                         mstate->cb_list = cb->next;
 741                         fptr_ok(fptr_whitelist_mesh_cb(cb->cb));
 742                         (*cb->cb)(cb->cb_arg, LDNS_RCODE_SERVFAIL, NULL,
 743                                 sec_status_unchecked, NULL);
 744                         mesh->num_reply_addrs--;
 745                 }
 746         }
 747
 748         /* de-init modules */
 749         for(i=0; i<mesh->mods.num; i++) {
 750                 fptr_ok(fptr_whitelist_mod_clear(mesh->mods.mod[i]->clear));
 751                 (*mesh->mods.mod[i]->clear)(&mstate->s, i);
 752                 mstate->s.minfo[i] = NULL;
 753                 mstate->s.ext_state[i] = module_finished;
 754         }
 755         alloc_reg_release(mstate->s.env->alloc, mstate->s.region);
 756 }
 757
 758 void
 759 mesh_state_delete(struct module_qstate* qstate)
 760 {
 761         struct mesh_area* mesh;
 762         struct mesh_state_ref* super, ref;
 763         struct mesh_state* mstate;
 764         if(!qstate)
 765                 return;
 766         mstate = qstate->mesh_info;
 767         mesh = mstate->s.env->mesh;
 768         mesh_detach_subs(&mstate->s);
 769         if(mstate->list_select == mesh_forever_list) {
 770                 mesh->num_forever_states --;
 771                 mesh_list_remove(mstate, &mesh->forever_first,
 772                         &mesh->forever_last);
 773         } else if(mstate->list_select == mesh_jostle_list) {
 774                 mesh_list_remove(mstate, &mesh->jostle_first,
 775                         &mesh->jostle_last);
 776         }
 777         if(!mstate->reply_list && !mstate->cb_list
 778                 && mstate->super_set.count == 0) {
 779                 log_assert(mesh->num_detached_states > 0);
 780                 mesh->num_detached_states--;
 781         }
 782         if(mstate->reply_list || mstate->cb_list) {
 783                 log_assert(mesh->num_reply_states > 0);
 784                 mesh->num_reply_states--;
 785         }
 786         ref.node.key = &ref;
 787         ref.s = mstate;
 788         RBTREE_FOR(super, struct mesh_state_ref*, &mstate->super_set) {
 789                 (void)rbtree_delete(&super->s->sub_set, &ref);
 790         }
 791         (void)rbtree_delete(&mesh->run, mstate);
 792         (void)rbtree_delete(&mesh->all, mstate);
 793         mesh_state_cleanup(mstate);
 794 }
 795
 796 /** helper recursive rbtree find routine */
 797 static int
 798 find_in_subsub(struct mesh_state* m, struct mesh_state* tofind, size_t *c)
 799 {
 800         struct mesh_state_ref* r;
 801         if((*c)++ > MESH_MAX_SUBSUB)
 802                 return 1;
 803         RBTREE_FOR(r, struct mesh_state_ref*, &m->sub_set) {
 804                 if(r->s == tofind || find_in_subsub(r->s, tofind, c))
 805                         return 1;
 806         }
 807         return 0;
 808 }
 809
 810 /** find cycle for already looked up mesh_state */
 811 static int
 812 mesh_detect_cycle_found(struct module_qstate* qstate, struct mesh_state* dep_m)
 813 {
 814         struct mesh_state* cyc_m = qstate->mesh_info;
 815         size_t counter = 0;
 816         if(!dep_m)
 817                 return 0;
 818         if(dep_m == cyc_m || find_in_subsub(dep_m, cyc_m, &counter)) {
 819                 if(counter > MESH_MAX_SUBSUB)
 820                         return 2;
 821                 return 1;
 822         }
 823         return 0;
 824 }
 825
 826 void mesh_detach_subs(struct module_qstate* qstate)
 827 {
 828         struct mesh_area* mesh = qstate->env->mesh;
 829         struct mesh_state_ref* ref, lookup;
 830 #ifdef UNBOUND_DEBUG
 831         struct rbnode_type* n;
 832 #endif
 833         lookup.node.key = &lookup;
 834         lookup.s = qstate->mesh_info;
 835         RBTREE_FOR(ref, struct mesh_state_ref*, &qstate->mesh_info->sub_set) {
 836 #ifdef UNBOUND_DEBUG
 837                 n =
 838 #else
 839                 (void)
 840 #endif
 841                 rbtree_delete(&ref->s->super_set, &lookup);
 842                 log_assert(n != NULL); /* must have been present */
 843                 if(!ref->s->reply_list && !ref->s->cb_list
 844                         && ref->s->super_set.count == 0) {
 845                         mesh->num_detached_states++;
 846                         log_assert(mesh->num_detached_states +
 847                                 mesh->num_reply_states <= mesh->all.count);
 848                 }
 849         }
 850         rbtree_init(&qstate->mesh_info->sub_set, &mesh_state_ref_compare);
 851 }
 852
 853 int mesh_add_sub(struct module_qstate* qstate, struct query_info* qinfo,
 854         uint16_t qflags, int prime, int valrec, struct module_qstate** newq,
 855         struct mesh_state** sub)
 856 {
 857         /* find it, if not, create it */
 858         struct mesh_area* mesh = qstate->env->mesh;
 859         *sub = mesh_area_find(mesh, NULL, qinfo, qflags,
 860                 prime, valrec);
 861         if(mesh_detect_cycle_found(qstate, *sub)) {
 862                 verbose(VERB_ALGO, "attach failed, cycle detected");
 863                 return 0;
 864         }
 865         if(!*sub) {
 866 #ifdef UNBOUND_DEBUG
 867                 struct rbnode_type* n;
 868 #endif
 869                 /* create a new one */
 870                 *sub = mesh_state_create(qstate->env, qinfo, NULL, qflags, prime,
 871                         valrec);
 872                 if(!*sub) {
 873                         log_err("mesh_attach_sub: out of memory");
 874                         return 0;
 875                 }
 876 #ifdef UNBOUND_DEBUG
 877                 n =
 878 #else
 879                 (void)
 880 #endif
 881                 rbtree_insert(&mesh->all, &(*sub)->node);
 882                 log_assert(n != NULL);
 883                 /* set detached (it is now) */
 884                 mesh->num_detached_states++;
 885                 /* set new query state to run */
 886 #ifdef UNBOUND_DEBUG
 887                 n =
 888 #else
 889                 (void)
 890 #endif
 891                 rbtree_insert(&mesh->run, &(*sub)->run_node);
 892                 log_assert(n != NULL);
 893                 *newq = &(*sub)->s;
 894         } else
 895                 *newq = NULL;
 896         return 1;
 897 }
 898
 899 int mesh_attach_sub(struct module_qstate* qstate, struct query_info* qinfo,
 900         uint16_t qflags, int prime, int valrec, struct module_qstate** newq)
 901 {
 902         struct mesh_area* mesh = qstate->env->mesh;
 903         struct mesh_state* sub = NULL;
 904         int was_detached;
 905         if(!mesh_add_sub(qstate, qinfo, qflags, prime, valrec, newq, &sub))
 906                 return 0;
 907         was_detached = (sub->super_set.count == 0);
 908         if(!mesh_state_attachment(qstate->mesh_info, sub))
 909                 return 0;
 910         /* if it was a duplicate  attachment, the count was not zero before */
 911         if(!sub->reply_list && !sub->cb_list && was_detached &&
 912                 sub->super_set.count == 1) {
 913                 /* it used to be detached, before this one got added */
 914                 log_assert(mesh->num_detached_states > 0);
 915                 mesh->num_detached_states--;
 916         }
 917         /* *newq will be run when inited after the current module stops */
 918         return 1;
 919 }
 920
 921 int mesh_state_attachment(struct mesh_state* super, struct mesh_state* sub)
 922 {
 923 #ifdef UNBOUND_DEBUG
 924         struct rbnode_type* n;
 925 #endif
 926         struct mesh_state_ref* subref; /* points to sub, inserted in super */
 927         struct mesh_state_ref* superref; /* points to super, inserted in sub */
 928         if( !(subref = regional_alloc(super->s.region,
 929                 sizeof(struct mesh_state_ref))) ||
 930                 !(superref = regional_alloc(sub->s.region,
 931                 sizeof(struct mesh_state_ref))) ) {
 932                 log_err("mesh_state_attachment: out of memory");
 933                 return 0;
 934         }
 935         superref->node.key = superref;
 936         superref->s = super;
 937         subref->node.key = subref;
 938         subref->s = sub;
 939         if(!rbtree_insert(&sub->super_set, &superref->node)) {
 940                 /* this should not happen, iterator and validator do not
 941                  * attach subqueries that are identical. */
 942                 /* already attached, we are done, nothing todo.
 943                  * since superref and subref already allocated in region,
 944                  * we cannot free them */
 945                 return 1;
 946         }
 947 #ifdef UNBOUND_DEBUG
 948         n =
 949 #else
 950         (void)
 951 #endif
 952         rbtree_insert(&super->sub_set, &subref->node);
 953         log_assert(n != NULL); /* we checked above if statement, the reverse
 954           administration should not fail now, unless they are out of sync */
 955         return 1;
 956 }
 957
 958 /**
 959  * callback results to mesh cb entry
 960  * @param m: mesh state to send it for.
 961  * @param rcode: if not 0, error code.
 962  * @param rep: reply to send (or NULL if rcode is set).
 963  * @param r: callback entry
 964  */
 965 static void
 966 mesh_do_callback(struct mesh_state* m, int rcode, struct reply_info* rep,
 967         struct mesh_cb* r)
 968 {
 969         int secure;
 970         char* reason = NULL;
 971         /* bogus messages are not made into servfail, sec_status passed
 972          * to the callback function */
 973         if(rep && rep->security == sec_status_secure)
 974                 secure = 1;
 975         else    secure = 0;
 976         if(!rep && rcode == LDNS_RCODE_NOERROR)
 977                 rcode = LDNS_RCODE_SERVFAIL;
 978         if(!rcode && (rep->security == sec_status_bogus ||
 979                 rep->security == sec_status_secure_sentinel_fail)) {
 980                 if(!(reason = errinf_to_str(&m->s)))
 981                         rcode = LDNS_RCODE_SERVFAIL;
 982         }
 983         /* send the reply */
 984         if(rcode) {
 985                 if(rcode == LDNS_RCODE_SERVFAIL) {
 986                         if(!inplace_cb_reply_servfail_call(m->s.env, &m->s.qinfo, &m->s,
 987                                 rep, rcode, &r->edns, m->s.region))
 988                                         r->edns.opt_list = NULL;
 989                 } else {
 990                         if(!inplace_cb_reply_call(m->s.env, &m->s.qinfo, &m->s, rep, rcode,
 991                                 &r->edns, m->s.region))
 992                                         r->edns.opt_list = NULL;
 993                 }
 994                 fptr_ok(fptr_whitelist_mesh_cb(r->cb));
 995                 (*r->cb)(r->cb_arg, rcode, r->buf, sec_status_unchecked, NULL);
 996         } else {
 997                 size_t udp_size = r->edns.udp_size;
 998                 sldns_buffer_clear(r->buf);
 999                 r->edns.edns_version = EDNS_ADVERTISED_VERSION;
1000                 r->edns.udp_size = EDNS_ADVERTISED_SIZE;
1001                 r->edns.ext_rcode = 0;
1002                 r->edns.bits &= EDNS_DO;
1003
1004                 if(!inplace_cb_reply_call(m->s.env, &m->s.qinfo, &m->s, rep,
1005                         LDNS_RCODE_NOERROR, &r->edns, m->s.region) ||
1006                         !reply_info_answer_encode(&m->s.qinfo, rep, r->qid,
1007                         r->qflags, r->buf, 0, 1,
1008                         m->s.env->scratch, udp_size, &r->edns,
1009                         (int)(r->edns.bits & EDNS_DO), secure))
1010                 {
1011                         fptr_ok(fptr_whitelist_mesh_cb(r->cb));
1012                         (*r->cb)(r->cb_arg, LDNS_RCODE_SERVFAIL, r->buf,
1013                                 sec_status_unchecked, NULL);
1014                 } else {
1015                         fptr_ok(fptr_whitelist_mesh_cb(r->cb));
1016                         (*r->cb)(r->cb_arg, LDNS_RCODE_NOERROR, r->buf,
1017                                 rep->security, reason);
1018                 }
1019         }
1020         free(reason);
1021         m->s.env->mesh->num_reply_addrs--;
1022 }
1023
1024 /**
1025  * Send reply to mesh reply entry
1026  * @param m: mesh state to send it for.
1027  * @param rcode: if not 0, error code.
1028  * @param rep: reply to send (or NULL if rcode is set).
1029  * @param r: reply entry
1030  * @param prev: previous reply, already has its answer encoded in buffer.
1031  */
1032 static void
1033 mesh_send_reply(struct mesh_state* m, int rcode, struct reply_info* rep,
1034         struct mesh_reply* r, struct mesh_reply* prev)
1035 {
1036         struct timeval end_time;
1037         struct timeval duration;
1038         int secure;
1039         /* Copy the client's EDNS for later restore, to make sure the edns
1040          * compare is with the correct edns options. */
1041         struct edns_data edns_bak = r->edns;
1042         /* examine security status */
1043         if(m->s.env->need_to_validate && (!(r->qflags&BIT_CD) ||
1044                 m->s.env->cfg->ignore_cd) && rep &&
1045                 (rep->security <= sec_status_bogus ||
1046                 rep->security == sec_status_secure_sentinel_fail)) {
1047                 rcode = LDNS_RCODE_SERVFAIL;
1048                 if(m->s.env->cfg->stat_extended)
1049                         m->s.env->mesh->ans_bogus++;
1050         }
1051         if(rep && rep->security == sec_status_secure)
1052                 secure = 1;
1053         else    secure = 0;
1054         if(!rep && rcode == LDNS_RCODE_NOERROR)
1055                 rcode = LDNS_RCODE_SERVFAIL;
1056         /* send the reply */
1057         /* We don't reuse the encoded answer if either the previous or current
1058          * response has a local alias.  We could compare the alias records
1059          * and still reuse the previous answer if they are the same, but that
1060          * would be complicated and error prone for the relatively minor case.
1061          * So we err on the side of safety. */
1062         if(prev && prev->qflags == r->qflags &&
1063                 !prev->local_alias && !r->local_alias &&
1064                 prev->edns.edns_present == r->edns.edns_present &&
1065                 prev->edns.bits == r->edns.bits &&
1066                 prev->edns.udp_size == r->edns.udp_size &&
1067                 edns_opt_list_compare(prev->edns.opt_list, r->edns.opt_list)
1068                 == 0) {
1069                 /* if the previous reply is identical to this one, fix ID */
1070                 if(prev->query_reply.c->buffer != r->query_reply.c->buffer)
1071                         sldns_buffer_copy(r->query_reply.c->buffer,
1072                                 prev->query_reply.c->buffer);
1073                 sldns_buffer_write_at(r->query_reply.c->buffer, 0,
1074                         &r->qid, sizeof(uint16_t));
1075                 sldns_buffer_write_at(r->query_reply.c->buffer, 12,
1076                         r->qname, m->s.qinfo.qname_len);
1077                 comm_point_send_reply(&r->query_reply);
1078         } else if(rcode) {
1079                 m->s.qinfo.qname = r->qname;
1080                 m->s.qinfo.local_alias = r->local_alias;
1081                 if(rcode == LDNS_RCODE_SERVFAIL) {
1082                         if(!inplace_cb_reply_servfail_call(m->s.env, &m->s.qinfo, &m->s,
1083                                 rep, rcode, &r->edns, m->s.region))
1084                                         r->edns.opt_list = NULL;
1085                 } else {
1086                         if(!inplace_cb_reply_call(m->s.env, &m->s.qinfo, &m->s, rep, rcode,
1087                                 &r->edns, m->s.region))
1088                                         r->edns.opt_list = NULL;
1089                 }
1090                 error_encode(r->query_reply.c->buffer, rcode, &m->s.qinfo,
1091                         r->qid, r->qflags, &r->edns);
1092                 comm_point_send_reply(&r->query_reply);
1093         } else {
1094                 size_t udp_size = r->edns.udp_size;
1095                 r->edns.edns_version = EDNS_ADVERTISED_VERSION;
1096                 r->edns.udp_size = EDNS_ADVERTISED_SIZE;
1097                 r->edns.ext_rcode = 0;
1098                 r->edns.bits &= EDNS_DO;
1099                 m->s.qinfo.qname = r->qname;
1100                 m->s.qinfo.local_alias = r->local_alias;
1101                 if(!inplace_cb_reply_call(m->s.env, &m->s.qinfo, &m->s, rep,
1102                         LDNS_RCODE_NOERROR, &r->edns, m->s.region) ||
1103                         !reply_info_answer_encode(&m->s.qinfo, rep, r->qid,
1104                         r->qflags, r->query_reply.c->buffer, 0, 1,
1105                         m->s.env->scratch, udp_size, &r->edns,
1106                         (int)(r->edns.bits & EDNS_DO), secure))
1107                 {
1108                         if(!inplace_cb_reply_servfail_call(m->s.env, &m->s.qinfo, &m->s,
1109                         rep, LDNS_RCODE_SERVFAIL, &r->edns, m->s.region))
1110                                 r->edns.opt_list = NULL;
1111                         error_encode(r->query_reply.c->buffer,
1112                                 LDNS_RCODE_SERVFAIL, &m->s.qinfo, r->qid,
1113                                 r->qflags, &r->edns);
1114                 }
1115                 r->edns = edns_bak;
1116                 comm_point_send_reply(&r->query_reply);
1117         }
1118         /* account */
1119         m->s.env->mesh->num_reply_addrs--;
1120         end_time = *m->s.env->now_tv;
1121         timeval_subtract(&duration, &end_time, &r->start_time);
1122         verbose(VERB_ALGO, "query took " ARG_LL "d.%6.6d sec",
1123                 (long long)duration.tv_sec, (int)duration.tv_usec);
1124         m->s.env->mesh->replies_sent++;
1125         timeval_add(&m->s.env->mesh->replies_sum_wait, &duration);
1126         timehist_insert(m->s.env->mesh->histogram, &duration);
1127         if(m->s.env->cfg->stat_extended) {
1128                 uint16_t rc = FLAGS_GET_RCODE(sldns_buffer_read_u16_at(r->
1129                         query_reply.c->buffer, 2));
1130                 if(secure) m->s.env->mesh->ans_secure++;
1131                 m->s.env->mesh->ans_rcode[ rc ] ++;
1132                 if(rc == 0 && LDNS_ANCOUNT(sldns_buffer_begin(r->
1133                         query_reply.c->buffer)) == 0)
1134                         m->s.env->mesh->ans_nodata++;
1135         }
1136         /* Log reply sent */
1137         if(m->s.env->cfg->log_replies) {
1138                 log_reply_info(0, &m->s.qinfo, &r->query_reply.addr,
1139                         r->query_reply.addrlen, duration, 0,
1140                         r->query_reply.c->buffer);
1141         }
1142 }
1143
1144 void mesh_query_done(struct mesh_state* mstate)
1145 {
1146         struct mesh_reply* r;
1147         struct mesh_reply* prev = NULL;
1148         struct mesh_cb* c;
1149         struct reply_info* rep = (mstate->s.return_msg?
1150                 mstate->s.return_msg->rep:NULL);
1151         for(r = mstate->reply_list; r; r = r->next) {
1152                 /* if a response-ip address block has been stored the
1153                  *  information should be logged for each client. */
1154                 if(mstate->s.respip_action_info &&
1155                         mstate->s.respip_action_info->addrinfo) {
1156                         respip_inform_print(mstate->s.respip_action_info->addrinfo,
1157                                 r->qname, mstate->s.qinfo.qtype,
1158                                 mstate->s.qinfo.qclass, r->local_alias,
1159                                 &r->query_reply);
1160                 }
1161
1162                 /* if this query is determined to be dropped during the
1163                  * mesh processing, this is the point to take that action. */
1164                 if(mstate->s.is_drop)
1165                         comm_point_drop_reply(&r->query_reply);
1166                 else {
1167                         mesh_send_reply(mstate, mstate->s.return_rcode, rep,
1168                                 r, prev);
1169                         prev = r;
1170                 }
1171         }
1172         mstate->replies_sent = 1;
1173         while((c = mstate->cb_list) != NULL) {
1174                 /* take this cb off the list; so that the list can be
1175                  * changed, eg. by adds from the callback routine */
1176                 if(!mstate->reply_list && mstate->cb_list && !c->next) {
1177                         /* was a reply state, not anymore */
1178                         mstate->s.env->mesh->num_reply_states--;
1179                 }
1180                 mstate->cb_list = c->next;
1181                 if(!mstate->reply_list && !mstate->cb_list &&
1182                         mstate->super_set.count == 0)
1183                         mstate->s.env->mesh->num_detached_states++;
1184                 mesh_do_callback(mstate, mstate->s.return_rcode, rep, c);
1185         }
1186 }
1187
1188 void mesh_walk_supers(struct mesh_area* mesh, struct mesh_state* mstate)
1189 {
1190         struct mesh_state_ref* ref;
1191         RBTREE_FOR(ref, struct mesh_state_ref*, &mstate->super_set)
1192         {
1193                 /* make super runnable */
1194                 (void)rbtree_insert(&mesh->run, &ref->s->run_node);
1195                 /* callback the function to inform super of result */
1196                 fptr_ok(fptr_whitelist_mod_inform_super(
1197                         mesh->mods.mod[ref->s->s.curmod]->inform_super));
1198                 (*mesh->mods.mod[ref->s->s.curmod]->inform_super)(&mstate->s,
1199                         ref->s->s.curmod, &ref->s->s);
1200         }
1201 }
1202
1203 struct mesh_state* mesh_area_find(struct mesh_area* mesh,
1204         struct respip_client_info* cinfo, struct query_info* qinfo,
1205         uint16_t qflags, int prime, int valrec)
1206 {
1207         struct mesh_state key;
1208         struct mesh_state* result;
1209
1210         key.node.key = &key;
1211         key.s.is_priming = prime;
1212         key.s.is_valrec = valrec;
1213         key.s.qinfo = *qinfo;
1214         key.s.query_flags = qflags;
1215         /* We are searching for a similar mesh state when we DO want to
1216          * aggregate the state. Thus unique is set to NULL. (default when we
1217          * desire aggregation).*/
1218         key.unique = NULL;
1219         key.s.client_info = cinfo;
1220
1221         result = (struct mesh_state*)rbtree_search(&mesh->all, &key);
1222         return result;
1223 }
1224
1225 int mesh_state_add_cb(struct mesh_state* s, struct edns_data* edns,
1226         sldns_buffer* buf, mesh_cb_func_type cb, void* cb_arg,
1227         uint16_t qid, uint16_t qflags)
1228 {
1229         struct mesh_cb* r = regional_alloc(s->s.region,
1230                 sizeof(struct mesh_cb));
1231         if(!r)
1232                 return 0;
1233         r->buf = buf;
1234         log_assert(fptr_whitelist_mesh_cb(cb)); /* early failure ifmissing*/
1235         r->cb = cb;
1236         r->cb_arg = cb_arg;
1237         r->edns = *edns;
1238         if(edns->opt_list) {
1239                 r->edns.opt_list = edns_opt_copy_region(edns->opt_list,
1240                         s->s.region);
1241                 if(!r->edns.opt_list)
1242                         return 0;
1243         }
1244         r->qid = qid;
1245         r->qflags = qflags;
1246         r->next = s->cb_list;
1247         s->cb_list = r;
1248         return 1;
1249
1250 }
1251
1252 int mesh_state_add_reply(struct mesh_state* s, struct edns_data* edns,
1253         struct comm_reply* rep, uint16_t qid, uint16_t qflags,
1254         const struct query_info* qinfo)
1255 {
1256         struct mesh_reply* r = regional_alloc(s->s.region,
1257                 sizeof(struct mesh_reply));
1258         if(!r)
1259                 return 0;
1260         r->query_reply = *rep;
1261         r->edns = *edns;
1262         if(edns->opt_list) {
1263                 r->edns.opt_list = edns_opt_copy_region(edns->opt_list,
1264                         s->s.region);
1265                 if(!r->edns.opt_list)
1266                         return 0;
1267         }
1268         r->qid = qid;
1269         r->qflags = qflags;
1270         r->start_time = *s->s.env->now_tv;
1271         r->next = s->reply_list;
1272         r->qname = regional_alloc_init(s->s.region, qinfo->qname,
1273                 s->s.qinfo.qname_len);
1274         if(!r->qname)
1275                 return 0;
1276
1277         /* Data related to local alias stored in 'qinfo' (if any) is ephemeral
1278          * and can be different for different original queries (even if the
1279          * replaced query name is the same).  So we need to make a deep copy
1280          * and store the copy for each reply info. */
1281         if(qinfo->local_alias) {
1282                 struct packed_rrset_data* d;
1283                 struct packed_rrset_data* dsrc;
1284                 r->local_alias = regional_alloc_zero(s->s.region,
1285                         sizeof(*qinfo->local_alias));
1286                 if(!r->local_alias)
1287                         return 0;
1288                 r->local_alias->rrset = regional_alloc_init(s->s.region,
1289                         qinfo->local_alias->rrset,
1290                         sizeof(*qinfo->local_alias->rrset));
1291                 if(!r->local_alias->rrset)
1292                         return 0;
1293                 dsrc = qinfo->local_alias->rrset->entry.data;
1294
1295                 /* In the current implementation, a local alias must be
1296                  * a single CNAME RR (see worker_handle_request()). */
1297                 log_assert(!qinfo->local_alias->next && dsrc->count == 1 &&
1298                         qinfo->local_alias->rrset->rk.type ==
1299                         htons(LDNS_RR_TYPE_CNAME));
1300                 /* Technically, we should make a local copy for the owner
1301                  * name of the RRset, but in the case of the first (and
1302                  * currently only) local alias RRset, the owner name should
1303                  * point to the qname of the corresponding query, which should
1304                  * be valid throughout the lifetime of this mesh_reply.  So
1305                  * we can skip copying. */
1306                 log_assert(qinfo->local_alias->rrset->rk.dname ==
1307                         sldns_buffer_at(rep->c->buffer, LDNS_HEADER_SIZE));
1308
1309                 d = regional_alloc_init(s->s.region, dsrc,
1310                         sizeof(struct packed_rrset_data)
1311                         + sizeof(size_t) + sizeof(uint8_t*) + sizeof(time_t));
1312                 if(!d)
1313                         return 0;
1314                 r->local_alias->rrset->entry.data = d;
1315                 d->rr_len = (size_t*)((uint8_t*)d +
1316                         sizeof(struct packed_rrset_data));
1317                 d->rr_data = (uint8_t**)&(d->rr_len[1]);
1318                 d->rr_ttl = (time_t*)&(d->rr_data[1]);
1319                 d->rr_len[0] = dsrc->rr_len[0];
1320                 d->rr_ttl[0] = dsrc->rr_ttl[0];
1321                 d->rr_data[0] = regional_alloc_init(s->s.region,
1322                         dsrc->rr_data[0], d->rr_len[0]);
1323                 if(!d->rr_data[0])
1324                         return 0;
1325         } else
1326                 r->local_alias = NULL;
1327
1328         s->reply_list = r;
1329         return 1;
1330 }
1331
1332 /* Extract the query info and flags from 'mstate' into '*qinfop' and '*qflags'.
1333  * Since this is only used for internal refetch of otherwise-expired answer,
1334  * we simply ignore the rare failure mode when memory allocation fails. */
1335 static void
1336 mesh_copy_qinfo(struct mesh_state* mstate, struct query_info** qinfop,
1337         uint16_t* qflags)
1338 {
1339         struct regional* region = mstate->s.env->scratch;
1340         struct query_info* qinfo;
1341
1342         qinfo = regional_alloc_init(region, &mstate->s.qinfo, sizeof(*qinfo));
1343         if(!qinfo)
1344                 return;
1345         qinfo->qname = regional_alloc_init(region, qinfo->qname,
1346                 qinfo->qname_len);
1347         if(!qinfo->qname)
1348                 return;
1349         *qinfop = qinfo;
1350         *qflags = mstate->s.query_flags;
1351 }
1352
1353 /**
1354  * Continue processing the mesh state at another module.
1355  * Handles module to modules transfer of control.
1356  * Handles module finished.
1357  * @param mesh: the mesh area.
1358  * @param mstate: currently active mesh state.
1359  *      Deleted if finished, calls _done and _supers to
1360  *      send replies to clients and inform other mesh states.
1361  *      This in turn may create additional runnable mesh states.
1362  * @param s: state at which the current module exited.
1363  * @param ev: the event sent to the module.
1364  *      returned is the event to send to the next module.
1365  * @return true if continue processing at the new module.
1366  *      false if not continued processing is needed.
1367  */
1368 static int
1369 mesh_continue(struct mesh_area* mesh, struct mesh_state* mstate,
1370         enum module_ext_state s, enum module_ev* ev)
1371 {
1372         mstate->num_activated++;
1373         if(mstate->num_activated > MESH_MAX_ACTIVATION) {
1374                 /* module is looping. Stop it. */
1375                 log_err("internal error: looping module (%s) stopped",
1376                         mesh->mods.mod[mstate->s.curmod]->name);
1377                 log_query_info(VERB_QUERY, "pass error for qstate",
1378                         &mstate->s.qinfo);
1379                 s = module_error;
1380         }
1381         if(s == module_wait_module || s == module_restart_next) {
1382                 /* start next module */
1383                 mstate->s.curmod++;
1384                 if(mesh->mods.num == mstate->s.curmod) {
1385                         log_err("Cannot pass to next module; at last module");
1386                         log_query_info(VERB_QUERY, "pass error for qstate",
1387                                 &mstate->s.qinfo);
1388                         mstate->s.curmod--;
1389                         return mesh_continue(mesh, mstate, module_error, ev);
1390                 }
1391                 if(s == module_restart_next) {
1392                         int curmod = mstate->s.curmod;
1393                         for(; mstate->s.curmod < mesh->mods.num;
1394                                 mstate->s.curmod++) {
1395                                 fptr_ok(fptr_whitelist_mod_clear(
1396                                         mesh->mods.mod[mstate->s.curmod]->clear));
1397                                 (*mesh->mods.mod[mstate->s.curmod]->clear)
1398                                         (&mstate->s, mstate->s.curmod);
1399                                 mstate->s.minfo[mstate->s.curmod] = NULL;
1400                         }
1401                         mstate->s.curmod = curmod;
1402                 }
1403                 *ev = module_event_pass;
1404                 return 1;
1405         }
1406         if(s == module_wait_subquery && mstate->sub_set.count == 0) {
1407                 log_err("module cannot wait for subquery, subquery list empty");
1408                 log_query_info(VERB_QUERY, "pass error for qstate",
1409                         &mstate->s.qinfo);
1410                 s = module_error;
1411         }
1412         if(s == module_error && mstate->s.return_rcode == LDNS_RCODE_NOERROR) {
1413                 /* error is bad, handle pass back up below */
1414                 mstate->s.return_rcode = LDNS_RCODE_SERVFAIL;
1415         }
1416         if(s == module_error) {
1417                 mesh_query_done(mstate);
1418                 mesh_walk_supers(mesh, mstate);
1419                 mesh_state_delete(&mstate->s);
1420                 return 0;
1421         }
1422         if(s == module_finished) {
1423                 if(mstate->s.curmod == 0) {
1424                         struct query_info* qinfo = NULL;
1425                         uint16_t qflags;
1426
1427                         mesh_query_done(mstate);
1428                         mesh_walk_supers(mesh, mstate);
1429
1430                         /* If the answer to the query needs to be refetched
1431                          * from an external DNS server, we'll need to schedule
1432                          * a prefetch after removing the current state, so
1433                          * we need to make a copy of the query info here. */
1434                         if(mstate->s.need_refetch)
1435                                 mesh_copy_qinfo(mstate, &qinfo, &qflags);
1436
1437                         mesh_state_delete(&mstate->s);
1438                         if(qinfo) {
1439                                 mesh_schedule_prefetch(mesh, qinfo, qflags,
1440                                         0, 1);
1441                         }
1442                         return 0;
1443                 }
1444                 /* pass along the locus of control */
1445                 mstate->s.curmod --;
1446                 *ev = module_event_moddone;
1447                 return 1;
1448         }
1449         return 0;
1450 }
1451
1452 void mesh_run(struct mesh_area* mesh, struct mesh_state* mstate,
1453         enum module_ev ev, struct outbound_entry* e)
1454 {
1455         enum module_ext_state s;
1456         verbose(VERB_ALGO, "mesh_run: start");
1457         while(mstate) {
1458                 /* run the module */
1459                 fptr_ok(fptr_whitelist_mod_operate(
1460                         mesh->mods.mod[mstate->s.curmod]->operate));
1461                 (*mesh->mods.mod[mstate->s.curmod]->operate)
1462                         (&mstate->s, ev, mstate->s.curmod, e);
1463
1464                 /* examine results */
1465                 mstate->s.reply = NULL;
1466                 regional_free_all(mstate->s.env->scratch);
1467                 s = mstate->s.ext_state[mstate->s.curmod];
1468                 verbose(VERB_ALGO, "mesh_run: %s module exit state is %s",
1469                         mesh->mods.mod[mstate->s.curmod]->name, strextstate(s));
1470                 e = NULL;
1471                 if(mesh_continue(mesh, mstate, s, &ev))
1472                         continue;
1473
1474                 /* run more modules */
1475                 ev = module_event_pass;
1476                 if(mesh->run.count > 0) {
1477                         /* pop random element off the runnable tree */
1478                         mstate = (struct mesh_state*)mesh->run.root->key;
1479                         (void)rbtree_delete(&mesh->run, mstate);
1480                 } else mstate = NULL;
1481         }
1482         if(verbosity >= VERB_ALGO) {
1483                 mesh_stats(mesh, "mesh_run: end");
1484                 mesh_log_list(mesh);
1485         }
1486 }
1487
1488 void
1489 mesh_log_list(struct mesh_area* mesh)
1490 {
1491         char buf[30];
1492         struct mesh_state* m;
1493         int num = 0;
1494         RBTREE_FOR(m, struct mesh_state*, &mesh->all) {
1495                 snprintf(buf, sizeof(buf), "%d%s%s%s%s%s%s mod%d %s%s",
1496                         num++, (m->s.is_priming)?"p":"",  /* prime */
1497                         (m->s.is_valrec)?"v":"",  /* prime */
1498                         (m->s.query_flags&BIT_RD)?"RD":"",
1499                         (m->s.query_flags&BIT_CD)?"CD":"",
1500                         (m->super_set.count==0)?"d":"", /* detached */
1501                         (m->sub_set.count!=0)?"c":"",  /* children */
1502                         m->s.curmod, (m->reply_list)?"rep":"", /*hasreply*/
1503                         (m->cb_list)?"cb":"" /* callbacks */
1504                         );
1505                 log_query_info(VERB_ALGO, buf, &m->s.qinfo);
1506         }
1507 }
1508
1509 void
1510 mesh_stats(struct mesh_area* mesh, const char* str)
1511 {
1512         verbose(VERB_DETAIL, "%s %u recursion states (%u with reply, "
1513                 "%u detached), %u waiting replies, %u recursion replies "
1514                 "sent, %d replies dropped, %d states jostled out",
1515                 str, (unsigned)mesh->all.count,
1516                 (unsigned)mesh->num_reply_states,
1517                 (unsigned)mesh->num_detached_states,
1518                 (unsigned)mesh->num_reply_addrs,
1519                 (unsigned)mesh->replies_sent,
1520                 (unsigned)mesh->stats_dropped,
1521                 (unsigned)mesh->stats_jostled);
1522         if(mesh->replies_sent > 0) {
1523                 struct timeval avg;
1524                 timeval_divide(&avg, &mesh->replies_sum_wait,
1525                         mesh->replies_sent);
1526                 log_info("average recursion processing time "
1527                         ARG_LL "d.%6.6d sec",
1528                         (long long)avg.tv_sec, (int)avg.tv_usec);
1529                 log_info("histogram of recursion processing times");
1530                 timehist_log(mesh->histogram, "recursions");
1531         }
1532 }
1533
1534 void
1535 mesh_stats_clear(struct mesh_area* mesh)
1536 {
1537         if(!mesh)
1538                 return;
1539         mesh->replies_sent = 0;
1540         mesh->replies_sum_wait.tv_sec = 0;
1541         mesh->replies_sum_wait.tv_usec = 0;
1542         mesh->stats_jostled = 0;
1543         mesh->stats_dropped = 0;
1544         timehist_clear(mesh->histogram);
1545         mesh->ans_secure = 0;
1546         mesh->ans_bogus = 0;
1547         memset(&mesh->ans_rcode[0], 0, sizeof(size_t)*16);
1548         mesh->ans_nodata = 0;
1549 }
1550
1551 size_t
1552 mesh_get_mem(struct mesh_area* mesh)
1553 {
1554         struct mesh_state* m;
1555         size_t s = sizeof(*mesh) + sizeof(struct timehist) +
1556                 sizeof(struct th_buck)*mesh->histogram->num +
1557                 sizeof(sldns_buffer) + sldns_buffer_capacity(mesh->qbuf_bak);
1558         RBTREE_FOR(m, struct mesh_state*, &mesh->all) {
1559                 /* all, including m itself allocated in qstate region */
1560                 s += regional_get_mem(m->s.region);
1561         }
1562         return s;
1563 }
1564
1565 int
1566 mesh_detect_cycle(struct module_qstate* qstate, struct query_info* qinfo,
1567         uint16_t flags, int prime, int valrec)
1568 {
1569         struct mesh_area* mesh = qstate->env->mesh;
1570         struct mesh_state* dep_m = NULL;
1571         if(!mesh_state_is_unique(qstate->mesh_info))
1572                 dep_m = mesh_area_find(mesh, NULL, qinfo, flags, prime, valrec);
1573         return mesh_detect_cycle_found(qstate, dep_m);
1574 }
1575
1576 void mesh_list_insert(struct mesh_state* m, struct mesh_state** fp,
1577         struct mesh_state** lp)
1578 {
1579         /* insert as last element */
1580         m->prev = *lp;
1581         m->next = NULL;
1582         if(*lp)
1583                 (*lp)->next = m;
1584         else    *fp = m;
1585         *lp = m;
1586 }
1587
1588 void mesh_list_remove(struct mesh_state* m, struct mesh_state** fp,
1589         struct mesh_state** lp)
1590 {
1591         if(m->next)
1592                 m->next->prev = m->prev;
1593         else    *lp = m->prev;
1594         if(m->prev)
1595                 m->prev->next = m->next;
1596         else    *fp = m->next;
1597 }