mdw@git.distorted.org.uk Git - adns/blob - src/query.c

   1 /*
   2  * query.c
   3  * - overall query management (allocation, completion)
   4  * - per-query memory management
   5  * - query submission and cancellation (user-visible and internal)
   6  */
   7 /*
   8  *  This file is part of adns, which is
   9  *    Copyright (C) 1997-2000,2003,2006  Ian Jackson
  10  *    Copyright (C) 1999-2000,2003,2006  Tony Finch
  11  *    Copyright (C) 1991 Massachusetts Institute of Technology
  12  *  (See the file INSTALL for full details.)
  13  *
  14  *  This program is free software; you can redistribute it and/or modify
  15  *  it under the terms of the GNU General Public License as published by
  16  *  the Free Software Foundation; either version 2, or (at your option)
  17  *  any later version.
  18  *
  19  *  This program is distributed in the hope that it will be useful,
  20  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  *  GNU General Public License for more details.
  23  *
  24  *  You should have received a copy of the GNU General Public License
  25  *  along with this program; if not, write to the Free Software Foundation,
  26  *  Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  27  */
  28
  29 #include "internal.h"
  30
  31 #include <stdlib.h>
  32 #include <unistd.h>
  33 #include <errno.h>
  34
  35 #include <sys/time.h>
  36
  37 #include "internal.h"
  38
  39 static adns_query query_alloc(adns_state ads,
  40                               const typeinfo *typei, adns_rrtype type,
  41                               adns_queryflags flags, struct timeval now) {
  42   /* Allocate a virgin query and return it. */
  43   adns_query qu;
  44
  45   qu= malloc(sizeof(*qu));  if (!qu) return 0;
  46   qu->answer= malloc(sizeof(*qu->answer));
  47   if (!qu->answer) { free(qu); return 0; }
  48
  49   qu->ads= ads;
  50   qu->state= query_tosend;
  51   qu->back= qu->next= qu->parent= 0;
  52   LIST_INIT(qu->children);
  53   LINK_INIT(qu->siblings);
  54   LIST_INIT(qu->allocations);
  55   qu->interim_allocd= 0;
  56   qu->preserved_allocd= 0;
  57   qu->final_allocspace= 0;
  58
  59   qu->typei= typei;
  60   qu->query_dgram= 0;
  61   qu->query_dglen= 0;
  62   adns__vbuf_init(&qu->vb);
  63
  64   qu->cname_dgram= 0;
  65   qu->cname_dglen= qu->cname_begin= 0;
  66
  67   adns__vbuf_init(&qu->search_vb);
  68   qu->search_origlen= qu->search_pos= qu->search_doneabs= 0;
  69
  70   qu->id= -2; /* will be overwritten with real id before we leave adns */
  71   qu->flags= flags;
  72   qu->retries= 0;
  73   qu->udpnextserver= 0;
  74   qu->udpsent= 0;
  75   timerclear(&qu->timeout);
  76   qu->expires= now.tv_sec + MAXTTLBELIEVE;
  77
  78   memset(&qu->ctx,0,sizeof(qu->ctx));
  79
  80   qu->answer->status= adns_s_ok;
  81   qu->answer->cname= qu->answer->owner= 0;
  82   qu->answer->type= type;
  83   qu->answer->expires= -1;
  84   qu->answer->nrrs= 0;
  85   qu->answer->rrs.untyped= 0;
  86   qu->answer->rrsz= typei->getrrsz ? typei->getrrsz(type) : typei->rrsz;
  87
  88   return qu;
  89 }
  90
  91 static void query_submit(adns_state ads, adns_query qu,
  92                          const typeinfo *typei, vbuf *qumsg_vb, int id,
  93                          adns_queryflags flags, struct timeval now) {
  94   /* Fills in the query message in for a previously-allocated query,
  95    * and submits it.  Cannot fail.  Takes over the memory for qumsg_vb.
  96    */
  97
  98   qu->vb= *qumsg_vb;
  99   adns__vbuf_init(qumsg_vb);
 100
 101   qu->query_dgram= malloc(qu->vb.used);
 102   if (!qu->query_dgram) { adns__query_fail(qu,adns_s_nomemory); return; }
 103
 104   qu->id= id;
 105   qu->query_dglen= qu->vb.used;
 106   memcpy(qu->query_dgram,qu->vb.buf,qu->vb.used);
 107
 108   if (flags & adns__qf_nosend)
 109     ;
 110   else if (typei->query_send && !(flags & adns__qf_senddirect))
 111     typei->query_send(qu,now);
 112   else
 113     adns__query_send(qu, now);
 114 }
 115
 116 adns_status adns__internal_submit(adns_state ads, adns_query *query_r,
 117                                   const typeinfo *typei, adns_rrtype type,
 118                                   vbuf *qumsg_vb, int id,
 119                                   adns_queryflags flags, struct timeval now,
 120                                   const qcontext *ctx) {
 121   adns_query qu;
 122
 123   qu= query_alloc(ads,typei,type,flags & ~adns__qf_nosend,now);
 124   if (!qu) { adns__vbuf_free(qumsg_vb); return adns_s_nomemory; }
 125   *query_r= qu;
 126
 127   memcpy(&qu->ctx,ctx,sizeof(qu->ctx));
 128   query_submit(ads,qu, typei,qumsg_vb,id,flags,now);
 129
 130   return adns_s_ok;
 131 }
 132
 133 static void query_simple(adns_state ads, adns_query qu,
 134                          const char *owner, int ol,
 135                          const typeinfo *typei, adns_queryflags flags,
 136                          struct timeval now) {
 137   vbuf vb_new;
 138   int id;
 139   adns_status stat;
 140
 141   stat= adns__mkquery(ads,&qu->vb,&id, owner,ol,
 142                       typei,qu->answer->type, flags);
 143   if (stat) {
 144     if (stat == adns_s_querydomaintoolong && (flags & adns_qf_search)) {
 145       adns__search_next(ads,qu,now);
 146       return;
 147     } else {
 148       adns__query_fail(qu,stat);
 149       return;
 150     }
 151   }
 152
 153   vb_new= qu->vb;
 154   adns__vbuf_init(&qu->vb);
 155   query_submit(ads,qu, typei,&vb_new,id, flags,now);
 156 }
 157
 158 void adns__search_next(adns_state ads, adns_query qu, struct timeval now) {
 159   const char *nextentry;
 160   adns_status stat;
 161
 162   if (qu->search_doneabs<0) {
 163     nextentry= 0;
 164     qu->search_doneabs= 1;
 165   } else {
 166     if (qu->search_pos >= ads->nsearchlist) {
 167       if (qu->search_doneabs) {
 168         qu->search_vb.used= qu->search_origlen;
 169         stat= adns_s_nxdomain; goto x_fail;
 170       } else {
 171         nextentry= 0;
 172         qu->search_doneabs= 1;
 173       }
 174     } else {
 175       nextentry= ads->searchlist[qu->search_pos++];
 176     }
 177   }
 178
 179   qu->search_vb.used= qu->search_origlen;
 180   if (nextentry) {
 181     if (!adns__vbuf_append(&qu->search_vb,".",1) ||
 182         !adns__vbuf_appendstr(&qu->search_vb,nextentry))
 183       goto x_nomemory;
 184   }
 185
 186   free(qu->query_dgram);
 187   qu->query_dgram= 0; qu->query_dglen= 0;
 188
 189   query_simple(ads,qu, qu->search_vb.buf, qu->search_vb.used,
 190                qu->typei, qu->flags, now);
 191   return;
 192
 193 x_nomemory:
 194   stat= adns_s_nomemory;
 195 x_fail:
 196   adns__query_fail(qu,stat);
 197 }
 198
 199 static int save_owner(adns_query qu, const char *owner, int ol) {
 200   /* Returns 1 if OK, otherwise there was no memory. */
 201   adns_answer *ans;
 202
 203   if (!(qu->flags & adns_qf_owner)) return 1;
 204
 205   ans= qu->answer;
 206   assert(!ans->owner);
 207
 208   ans->owner= adns__alloc_preserved(qu,ol+1);  if (!ans->owner) return 0;
 209
 210   memcpy(ans->owner,owner,ol);
 211   ans->owner[ol]= 0;
 212   return 1;
 213 }
 214
 215 int adns_submit(adns_state ads,
 216                 const char *owner,
 217                 adns_rrtype type,
 218                 adns_queryflags flags,
 219                 void *context,
 220                 adns_query *query_r) {
 221   int r, ol, ndots;
 222   adns_status stat;
 223   const typeinfo *typei;
 224   struct timeval now;
 225   adns_query qu;
 226   const char *p;
 227
 228   adns__consistency(ads,0,cc_entex);
 229
 230   if (!(type & adns__qtf_bigaddr) || !(type & adns__qtf_manyaf))
 231     flags = (flags & ~adns__qf_afmask) | adns_qf_ipv4_only;
 232
 233   typei= adns__findtype(type);
 234   if (!typei) return ENOSYS;
 235
 236   r= gettimeofday(&now,0); if (r) goto x_errno;
 237   qu= query_alloc(ads,typei,type,flags,now); if (!qu) goto x_errno;
 238
 239   qu->ctx.ext= context;
 240   qu->ctx.callback= 0;
 241   memset(&qu->ctx.pinfo,0,sizeof(qu->ctx.pinfo));
 242   memset(&qu->ctx.tinfo,0,sizeof(qu->ctx.tinfo));
 243
 244   *query_r= qu;
 245
 246   ol= strlen(owner);
 247   if (!ol) { stat= adns_s_querydomaininvalid; goto x_adnsfail; }
 248   if (ol>DNS_MAXDOMAIN+1) { stat= adns_s_querydomaintoolong; goto x_adnsfail; }
 249
 250   if (ol>=1 && owner[ol-1]=='.' && (ol<2 || owner[ol-2]!='\\')) {
 251     flags &= ~adns_qf_search;
 252     qu->flags= flags;
 253     ol--;
 254   }
 255
 256   if (flags & adns_qf_search) {
 257     r= adns__vbuf_append(&qu->search_vb,owner,ol);
 258     if (!r) { stat= adns_s_nomemory; goto x_adnsfail; }
 259
 260     for (ndots=0, p=owner; (p= strchr(p,'.')); p++, ndots++);
 261     qu->search_doneabs= (ndots >= ads->searchndots) ? -1 : 0;
 262     qu->search_origlen= ol;
 263     adns__search_next(ads,qu,now);
 264   } else {
 265     if (flags & adns_qf_owner) {
 266       if (!save_owner(qu,owner,ol)) { stat= adns_s_nomemory; goto x_adnsfail; }
 267     }
 268     query_simple(ads,qu, owner,ol, typei,flags, now);
 269   }
 270   adns__autosys(ads,now);
 271   adns__consistency(ads,qu,cc_entex);
 272   return 0;
 273
 274  x_adnsfail:
 275   adns__query_fail(qu,stat);
 276   adns__consistency(ads,qu,cc_entex);
 277   return 0;
 278
 279  x_errno:
 280   r= errno;
 281   assert(r);
 282   adns__consistency(ads,0,cc_entex);
 283   return r;
 284 }
 285
 286 static const char *default_zone = "<magic>";
 287
 288 int adns_submit_reverse_any(adns_state ads,
 289                             const struct sockaddr *addr,
 290                             const char *zone,
 291                             adns_rrtype type,
 292                             adns_queryflags flags,
 293                             void *context,
 294                             adns_query *query_r) {
 295   char *buf, *buf_free, *p;
 296   char shortbuf[100];
 297   const afinfo *ai;
 298   int r, lreq;
 299
 300   flags &= ~adns_qf_search;
 301
 302   switch (addr->sa_family) {
 303     case AF_INET:
 304       ai = &adns__inet_afinfo;
 305       if (zone == default_zone) zone = "in-addr.arpa";
 306       break;
 307     case AF_INET6:
 308       ai = &adns__inet6_afinfo;
 309       if (zone == default_zone) zone = "ip6.arpa";
 310       break;
 311     default:
 312       return ENOSYS;
 313   }
 314
 315   lreq= strlen(zone) + ai->nrevcomp*(ai->revcompwd + 1) + 1;
 316   if (lreq > sizeof(shortbuf)) {
 317     buf= malloc(lreq);
 318     if (!buf) return errno;
 319     buf_free= buf;
 320   } else {
 321     buf= shortbuf;
 322     buf_free= 0;
 323   }
 324
 325   p = ai->rev_mkname(addr, buf);
 326   *p++ = '.';
 327   strcpy(p, zone);
 328
 329   r= adns_submit(ads,buf,type,flags,context,query_r);
 330   free(buf_free);
 331   return r;
 332 }
 333
 334 int adns_submit_reverse(adns_state ads,
 335                         const struct sockaddr *addr,
 336                         adns_rrtype type,
 337                         adns_queryflags flags,
 338                         void *context,
 339                         adns_query *query_r) {
 340   if (type != adns_r_ptr && type != adns_r_ptr_raw) return EINVAL;
 341   return adns_submit_reverse_any(ads,addr,default_zone,
 342                                  type,flags,context,query_r);
 343 }
 344
 345 int adns_synchronous(adns_state ads,
 346                      const char *owner,
 347                      adns_rrtype type,
 348                      adns_queryflags flags,
 349                      adns_answer **answer_r) {
 350   adns_query qu;
 351   int r;
 352
 353   r= adns_submit(ads,owner,type,flags,0,&qu);
 354   if (r) return r;
 355
 356   r= adns_wait(ads,&qu,answer_r,0);
 357   if (r) adns_cancel(qu);
 358
 359   return r;
 360 }
 361
 362 static void *alloc_common(adns_query qu, size_t sz) {
 363   allocnode *an;
 364
 365   if (!sz) return qu; /* Any old pointer will do */
 366   assert(!qu->final_allocspace);
 367   an= malloc(MEM_ROUND(MEM_ROUND(sizeof(*an)) + sz));
 368   if (!an) return 0;
 369   LIST_LINK_TAIL(qu->allocations,an);
 370   an->sz = sz;
 371   return (byte*)an + MEM_ROUND(sizeof(*an));
 372 }
 373
 374 void *adns__alloc_interim(adns_query qu, size_t sz) {
 375   void *rv;
 376
 377   sz= MEM_ROUND(sz);
 378   rv= alloc_common(qu,sz);
 379   if (!rv) return 0;
 380   qu->interim_allocd += sz;
 381   return rv;
 382 }
 383
 384 void *adns__alloc_preserved(adns_query qu, size_t sz) {
 385   void *rv;
 386
 387   sz= MEM_ROUND(sz);
 388   rv= adns__alloc_interim(qu,sz);
 389   if (!rv) return 0;
 390   qu->preserved_allocd += sz;
 391   return rv;
 392 }
 393
 394 static allocnode *alloc_info(adns_query qu, void *p, size_t *sz_r)
 395 {
 396   allocnode *an;
 397
 398   if (!p || p == qu) { *sz_r = 0; return 0; }
 399   an = (allocnode *)((byte *)p - MEM_ROUND(sizeof(allocnode)));
 400   *sz_r = MEM_ROUND(an->sz);
 401   return an;
 402 }
 403
 404 void adns__free_interim(adns_query qu, void *p) {
 405   size_t sz;
 406   allocnode *an = alloc_info(qu, p, &sz);
 407
 408   if (!an) return;
 409   assert(!qu->final_allocspace);
 410   LIST_UNLINK(qu->allocations, an);
 411   free(an);
 412   qu->interim_allocd -= sz;
 413 }
 414
 415 void *adns__alloc_mine(adns_query qu, size_t sz) {
 416   return alloc_common(qu,MEM_ROUND(sz));
 417 }
 418
 419 void adns__transfer_interim(adns_query from, adns_query to, void *block) {
 420   size_t sz;
 421   allocnode *an = alloc_info(from, block, &sz);
 422
 423   if (!an) return;
 424
 425   assert(!to->final_allocspace);
 426   assert(!from->final_allocspace);
 427
 428   LIST_UNLINK(from->allocations,an);
 429   LIST_LINK_TAIL(to->allocations,an);
 430
 431   from->interim_allocd -= sz;
 432   to->interim_allocd += sz;
 433
 434   if (to->expires > from->expires) to->expires= from->expires;
 435 }
 436
 437 void *adns__alloc_final(adns_query qu, size_t sz) {
 438   /* When we're in the _final stage, we _subtract_ from interim_alloc'd
 439    * each allocation, and use final_allocspace to point to the next free
 440    * bit.
 441    */
 442   void *rp;
 443
 444   sz= MEM_ROUND(sz);
 445   rp= qu->final_allocspace;
 446   assert(rp);
 447   qu->interim_allocd -= sz;
 448   assert(qu->interim_allocd>=0);
 449   qu->final_allocspace= (byte*)rp + sz;
 450   return rp;
 451 }
 452
 453 void adns__cancel_children(adns_query qu) {
 454   adns_query cqu, ncqu;
 455
 456   for (cqu= qu->children.head; cqu; cqu= ncqu) {
 457     ncqu= cqu->siblings.next;
 458     adns_cancel(cqu);
 459   }
 460 }
 461
 462 void adns__reset_preserved(adns_query qu) {
 463   assert(!qu->final_allocspace);
 464   adns__cancel_children(qu);
 465   qu->answer->nrrs= 0;
 466   qu->answer->rrs.untyped= 0;
 467   qu->interim_allocd= qu->preserved_allocd;
 468 }
 469
 470 static void free_query_allocs(adns_query qu) {
 471   allocnode *an, *ann;
 472
 473   adns__cancel_children(qu);
 474   for (an= qu->allocations.head; an; an= ann) { ann= an->next; free(an); }
 475   LIST_INIT(qu->allocations);
 476   adns__vbuf_free(&qu->vb);
 477   adns__vbuf_free(&qu->search_vb);
 478   free(qu->query_dgram);
 479   qu->query_dgram= 0;
 480 }
 481
 482 void adns_cancel(adns_query qu) {
 483   adns_state ads;
 484
 485   ads= qu->ads;
 486   adns__consistency(ads,qu,cc_entex);
 487   if (qu->parent) LIST_UNLINK_PART(qu->parent->children,qu,siblings.);
 488   switch (qu->state) {
 489   case query_tosend:
 490     LIST_UNLINK(ads->udpw,qu);
 491     break;
 492   case query_tcpw:
 493     LIST_UNLINK(ads->tcpw,qu);
 494     break;
 495   case query_childw:
 496     LIST_UNLINK(ads->childw,qu);
 497     break;
 498   case query_done:
 499     LIST_UNLINK(ads->output,qu);
 500     break;
 501   default:
 502     abort();
 503   }
 504   free_query_allocs(qu);
 505   free(qu->answer);
 506   free(qu);
 507   adns__consistency(ads,0,cc_entex);
 508 }
 509
 510 void adns__update_expires(adns_query qu, unsigned long ttl,
 511                           struct timeval now) {
 512   time_t max;
 513
 514   assert(ttl <= MAXTTLBELIEVE);
 515   max= now.tv_sec + ttl;
 516   if (qu->expires < max) return;
 517   qu->expires= max;
 518 }
 519
 520 static void makefinal_query(adns_query qu) {
 521   adns_answer *ans;
 522   int rrn;
 523
 524   ans= qu->answer;
 525
 526   if (qu->interim_allocd) {
 527     ans= realloc(qu->answer,
 528                  MEM_ROUND(MEM_ROUND(sizeof(*ans)) + qu->interim_allocd));
 529     if (!ans) goto x_nomem;
 530     qu->answer= ans;
 531   }
 532
 533   qu->final_allocspace= (byte*)ans + MEM_ROUND(sizeof(*ans));
 534   adns__makefinal_str(qu,&ans->cname);
 535   adns__makefinal_str(qu,&ans->owner);
 536
 537   if (ans->nrrs) {
 538     adns__makefinal_block(qu, &ans->rrs.untyped, ans->nrrs*ans->rrsz);
 539
 540     for (rrn=0; rrn<ans->nrrs; rrn++)
 541       qu->typei->makefinal(qu, ans->rrs.bytes + rrn*ans->rrsz);
 542   }
 543
 544   free_query_allocs(qu);
 545   return;
 546
 547  x_nomem:
 548   qu->preserved_allocd= 0;
 549   qu->answer->cname= 0;
 550   qu->answer->owner= 0;
 551   adns__reset_preserved(qu); /* (but we just threw away the preserved stuff) */
 552
 553   qu->answer->status= adns_s_nomemory;
 554   free_query_allocs(qu);
 555 }
 556
 557 void adns__query_done(adns_query qu) {
 558   adns_answer *ans;
 559   adns_query parent;
 560
 561   adns__cancel_children(qu);
 562
 563   qu->id= -1;
 564   ans= qu->answer;
 565
 566   if (qu->flags & adns_qf_search && ans->status != adns_s_nomemory) {
 567     if (!save_owner(qu, qu->search_vb.buf, qu->search_vb.used)) {
 568       adns__query_fail(qu,adns_s_nomemory);
 569       return;
 570     }
 571   }
 572
 573   if (ans->nrrs && qu->typei->diff_needswap) {
 574     if (!adns__vbuf_ensure(&qu->vb,ans->rrsz)) {
 575       adns__query_fail(qu,adns_s_nomemory);
 576       return;
 577     }
 578     adns__isort(ans->rrs.bytes, ans->nrrs, ans->rrsz,
 579                 qu->vb.buf,
 580                 (int(*)(void*, const void*, const void*))
 581                   qu->typei->diff_needswap,
 582                 qu->ads);
 583   }
 584   if (ans->nrrs && qu->typei->postsort) {
 585     qu->typei->postsort(qu->ads, ans->rrs.bytes, ans->nrrs, qu->typei);
 586   }
 587
 588   ans->expires= qu->expires;
 589   parent= qu->parent;
 590   if (parent) {
 591     LIST_UNLINK_PART(parent->children,qu,siblings.);
 592     LIST_UNLINK(qu->ads->childw,parent);
 593     qu->ctx.callback(parent,qu);
 594     free_query_allocs(qu);
 595     free(qu->answer);
 596     free(qu);
 597   } else {
 598     makefinal_query(qu);
 599     LIST_LINK_TAIL(qu->ads->output,qu);
 600     qu->state= query_done;
 601   }
 602 }
 603
 604 void adns__query_fail(adns_query qu, adns_status stat) {
 605   adns__reset_preserved(qu);
 606   qu->answer->status= stat;
 607   adns__query_done(qu);
 608 }
 609
 610 void adns__makefinal_str(adns_query qu, char **strp) {
 611   int l;
 612   char *before, *after;
 613
 614   before= *strp;
 615   if (!before) return;
 616   l= strlen(before)+1;
 617   after= adns__alloc_final(qu,l);
 618   memcpy(after,before,l);
 619   *strp= after;
 620 }
 621
 622 void adns__makefinal_block(adns_query qu, void **blpp, size_t sz) {
 623   void *before, *after;
 624
 625   before= *blpp;
 626   if (!before) return;
 627   after= adns__alloc_final(qu,sz);
 628   memcpy(after,before,sz);
 629   *blpp= after;
 630 }