reactos/lib/adns/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
   9  *    Copyright (C) 1997-2000 Ian Jackson <ian@davenant.greenend.org.uk>
  10  *
  11  *  It is part of adns, which is
  12  *    Copyright (C) 1997-2000 Ian Jackson <ian@davenant.greenend.org.uk>
  13  *    Copyright (C) 1999-2000 Tony Finch <dot@dotat.at>
  14  *
  15  *  This program is free software; you can redistribute it and/or modify
  16  *  it under the terms of the GNU General Public License as published by
  17  *  the Free Software Foundation; either version 2, or (at your option)
  18  *  any later version.
  19  *
  20  *  This program is distributed in the hope that it will be useful,
  21  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  22  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  23  *  GNU General Public License for more details.
  24  *
  25  *  You should have received a copy of the GNU General Public License
  26  *  along with this program; if not, write to the Free Software Foundation,
  27  *  Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  28  */
  29
  30 #ifdef ADNS_JGAA_WIN32
  31 # include "adns_win32.h"
  32 #else
  33 # include <stdlib.h>
  34 # include <unistd.h>
  35 # include <errno.h>
  36 # include <sys/time.h>
  37 #endif
  38
  39 #include "internal.h"
  40
  41 static adns_query query_alloc(adns_state ads, const typeinfo *typei,
  42                               adns_queryflags flags, struct timeval now) {
  43   /* Allocate a virgin query and return it. */
  44   adns_query qu;
  45
  46   qu= malloc(sizeof(*qu));  if (!qu) return 0;
  47   qu->answer= malloc(sizeof(*qu->answer));  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= typei->type;
  83   qu->answer->expires= -1;
  84   qu->answer->nrrs= 0;
  85   qu->answer->rrs.untyped= 0;
  86   qu->answer->rrsz= 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( (size_t) 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,(size_t) qu->vb.used);
 107
 108   adns__query_send(qu,now);
 109 }
 110
 111 adns_status adns__internal_submit(adns_state ads, adns_query *query_r,
 112                                   const typeinfo *typei, vbuf *qumsg_vb, int id,
 113                                   adns_queryflags flags, struct timeval now,
 114                                   const qcontext *ctx) {
 115   adns_query qu;
 116
 117   qu= query_alloc(ads,typei,flags,now);
 118   if (!qu) { adns__vbuf_free(qumsg_vb); return adns_s_nomemory; }
 119   *query_r= qu;
 120
 121   memcpy(&qu->ctx,ctx,(size_t) sizeof(qu->ctx));
 122   query_submit(ads,qu, typei,qumsg_vb,id,flags,now);
 123
 124   return adns_s_ok;
 125 }
 126
 127 static void query_simple(adns_state ads, adns_query qu,
 128                          const char *owner, int ol,
 129                          const typeinfo *typei, adns_queryflags flags,
 130                          struct timeval now) {
 131   vbuf vb_new;
 132   int id;
 133   adns_status stat;
 134
 135   stat= adns__mkquery(ads,&qu->vb,&id, owner,ol, typei,flags);
 136   if (stat) {
 137     if (stat == adns_s_querydomaintoolong && (flags & adns_qf_search)) {
 138       adns__search_next(ads,qu,now);
 139       return;
 140     } else {
 141       adns__query_fail(qu,stat);
 142       return;
 143     }
 144   }
 145
 146   vb_new= qu->vb;
 147   adns__vbuf_init(&qu->vb);
 148   query_submit(ads,qu, typei,&vb_new,id, flags,now);
 149 }
 150
 151 void adns__search_next(adns_state ads, adns_query qu, struct timeval now) {
 152   const char *nextentry;
 153   adns_status stat;
 154
 155   if (qu->search_doneabs<0) {
 156     nextentry= 0;
 157     qu->search_doneabs= 1;
 158   } else {
 159     if (qu->search_pos >= ads->nsearchlist) {
 160       if (qu->search_doneabs) {
 161         stat= adns_s_nxdomain; goto x_fail;
 162         return;
 163       } else {
 164         nextentry= 0;
 165         qu->search_doneabs= 1;
 166       }
 167     } else {
 168       nextentry= ads->searchlist[qu->search_pos++];
 169     }
 170   }
 171
 172   qu->search_vb.used= qu->search_origlen;
 173   if (nextentry) {
 174     if (!adns__vbuf_append(&qu->search_vb,(byte*)".",1) ||
 175         !adns__vbuf_appendstr(&qu->search_vb,nextentry)) {
 176       stat= adns_s_nomemory; goto x_fail;
 177     }
 178   }
 179
 180   free(qu->query_dgram);
 181   qu->query_dgram= 0; qu->query_dglen= 0;
 182
 183   query_simple(ads,qu, (char*)qu->search_vb.buf, qu->search_vb.used, qu->typei, qu->flags, now);
 184   return;
 185
 186 x_fail:
 187   adns__query_fail(qu,stat);
 188 }
 189
 190 static int save_owner(adns_query qu, const char *owner, int ol) {
 191   /* Returns 1 if OK, otherwise there was no memory. */
 192   adns_answer *ans;
 193
 194   ans= qu->answer;
 195   assert(!ans->owner);
 196
 197   ans->owner= adns__alloc_preserved(qu, (size_t) ol+1);  if (!ans->owner) return 0;
 198
 199   memcpy(ans->owner,owner, (size_t) ol);
 200   ans->owner[ol]= 0;
 201   return 1;
 202 }
 203
 204 int adns_submit(adns_state ads,
 205                 const char *owner,
 206                 adns_rrtype type,
 207                 adns_queryflags flags,
 208                 void *context,
 209                 adns_query *query_r) {
 210   int r, ol, ndots;
 211   adns_status stat;
 212   const typeinfo *typei;
 213   struct timeval now;
 214   adns_query qu;
 215   const char *p;
 216
 217   adns__consistency(ads,0,cc_entex);
 218
 219   typei= adns__findtype(type);
 220   if (!typei) return ENOSYS;
 221
 222   r= gettimeofday(&now,0); if (r) goto x_errno;
 223   qu= query_alloc(ads,typei,flags,now); if (!qu) goto x_errno;
 224
 225   qu->ctx.ext= context;
 226   qu->ctx.callback= 0;
 227   memset(&qu->ctx.info,0,sizeof(qu->ctx.info));
 228
 229   *query_r= qu;
 230
 231   ol= strlen(owner);
 232   if (!ol) { stat= adns_s_querydomaininvalid; goto x_adnsfail; }
 233   if (ol>DNS_MAXDOMAIN+1) { stat= adns_s_querydomaintoolong; goto x_adnsfail; }
 234
 235   if (ol>=1 && owner[ol-1]=='.' && (ol<2 || owner[ol-2]!='\\')) {
 236     flags &= ~adns_qf_search;
 237     qu->flags= flags;
 238     ol--;
 239   }
 240
 241   if (flags & adns_qf_search) {
 242     r= adns__vbuf_append(&qu->search_vb,(byte*)owner,ol);
 243     if (!r) { stat= adns_s_nomemory; goto x_adnsfail; }
 244
 245     for (ndots=0, p=owner; (p= strchr(p,'.')); p++, ndots++);
 246     qu->search_doneabs= (ndots >= ads->searchndots) ? -1 : 0;
 247     qu->search_origlen= ol;
 248     adns__search_next(ads,qu,now);
 249   } else {
 250     if (flags & adns_qf_owner) {
 251       if (!save_owner(qu,owner,ol)) { stat= adns_s_nomemory; goto x_adnsfail; }
 252     }
 253     query_simple(ads,qu, owner,ol, typei,flags, now);
 254   }
 255   adns__autosys(ads,now);
 256   adns__consistency(ads,qu,cc_entex);
 257   return 0;
 258
 259  x_adnsfail:
 260   adns__query_fail(qu,stat);
 261   adns__consistency(ads,qu,cc_entex);
 262   return 0;
 263
 264  x_errno:
 265   r= errno;
 266   assert(r);
 267   adns__consistency(ads,0,cc_entex);
 268   return r;
 269 }
 270
 271 int adns_submit_reverse_any(adns_state ads,
 272                             const struct sockaddr *addr,
 273                             const char *zone,
 274                             adns_rrtype type,
 275                             adns_queryflags flags,
 276                             void *context,
 277                             adns_query *query_r) {
 278   const unsigned char *iaddr;
 279   char *buf, *buf_free;
 280   char shortbuf[100];
 281   int r, lreq;
 282
 283   flags &= ~adns_qf_search;
 284
 285   if (addr->sa_family != AF_INET) return ENOSYS;
 286   iaddr= (const unsigned char*) &(((const struct sockaddr_in*)addr) -> sin_addr);
 287
 288   lreq= strlen(zone) + 4*4 + 1;
 289   if (lreq > sizeof(shortbuf)) {
 290     buf= malloc( strlen(zone) + 4*4 + 1 );
 291     if (!buf) return errno;
 292     buf_free= buf;
 293   } else {
 294     buf= shortbuf;
 295     buf_free= 0;
 296   }
 297   sprintf(buf, "%d.%d.%d.%d.%s", iaddr[3], iaddr[2], iaddr[1], iaddr[0], zone);
 298
 299   r= adns_submit(ads,buf,type,flags,context,query_r);
 300   free(buf_free);
 301   return r;
 302 }
 303
 304 int adns_submit_reverse(adns_state ads,
 305                         const struct sockaddr *addr,
 306                         adns_rrtype type,
 307                         adns_queryflags flags,
 308                         void *context,
 309                         adns_query *query_r) {
 310   if (type != adns_r_ptr && type != adns_r_ptr_raw) return EINVAL;
 311   return adns_submit_reverse_any(ads,addr,"in-addr.arpa",type,flags,context,query_r);
 312 }
 313
 314 int adns_synchronous(adns_state ads,
 315                      const char *owner,
 316                      adns_rrtype type,
 317                      adns_queryflags flags,
 318                      adns_answer **answer_r) {
 319   adns_query qu;
 320   int r;
 321
 322   r= adns_submit(ads,owner,type,flags,0,&qu);
 323   if (r) return r;
 324
 325   r= adns_wait(ads,&qu,answer_r,0);
 326   if (r) adns_cancel(qu);
 327
 328   return r;
 329 }
 330
 331 static void *alloc_common(adns_query qu, size_t sz) {
 332   allocnode *an;
 333
 334   if (!sz) return qu; /* Any old pointer will do */
 335   assert(!qu->final_allocspace);
 336   an= malloc(MEM_ROUND(MEM_ROUND(sizeof(*an)) + sz));
 337   if (!an) return 0;
 338   LIST_LINK_TAIL(qu->allocations,an);
 339   return (byte*)an + MEM_ROUND(sizeof(*an));
 340 }
 341
 342 void *adns__alloc_interim(adns_query qu, size_t sz) {
 343   void *rv;
 344
 345   sz= MEM_ROUND(sz);
 346   rv= alloc_common(qu,sz);
 347   if (!rv) return 0;
 348   qu->interim_allocd += sz;
 349   return rv;
 350 }
 351
 352 void *adns__alloc_preserved(adns_query qu, size_t sz) {
 353   void *rv;
 354
 355   sz= MEM_ROUND(sz);
 356   rv= adns__alloc_interim(qu,sz);
 357   if (!rv) return 0;
 358   qu->preserved_allocd += sz;
 359   return rv;
 360 }
 361
 362 void *adns__alloc_mine(adns_query qu, size_t sz) {
 363   return alloc_common(qu,MEM_ROUND(sz));
 364 }
 365
 366 void adns__transfer_interim(adns_query from, adns_query to, void *block, size_t sz) {
 367   allocnode *an;
 368
 369   if (!block) return;
 370   an= (void*)((byte*)block - MEM_ROUND(sizeof(*an)));
 371
 372   assert(!to->final_allocspace);
 373   assert(!from->final_allocspace);
 374
 375   LIST_UNLINK(from->allocations,an);
 376   LIST_LINK_TAIL(to->allocations,an);
 377
 378   sz= MEM_ROUND(sz);
 379   from->interim_allocd -= sz;
 380   to->interim_allocd += sz;
 381
 382   if (to->expires > from->expires) to->expires= from->expires;
 383 }
 384
 385 void *adns__alloc_final(adns_query qu, size_t sz) {
 386   /* When we're in the _final stage, we _subtract_ from interim_alloc'd
 387    * each allocation, and use final_allocspace to point to the next free
 388    * bit.
 389    */
 390   void *rp;
 391
 392   sz= MEM_ROUND(sz);
 393   rp= qu->final_allocspace;
 394   assert(rp);
 395   qu->interim_allocd -= sz;
 396   assert(qu->interim_allocd>=0);
 397   qu->final_allocspace= (byte*)rp + sz;
 398   return rp;
 399 }
 400
 401 static void cancel_children(adns_query qu) {
 402   adns_query cqu, ncqu;
 403
 404   for (cqu= qu->children.head; cqu; cqu= ncqu) {
 405     ncqu= cqu->siblings.next;
 406     adns_cancel(cqu);
 407   }
 408 }
 409
 410 void adns__reset_preserved(adns_query qu) {
 411   assert(!qu->final_allocspace);
 412   cancel_children(qu);
 413   qu->answer->nrrs= 0;
 414   qu->answer->rrs.untyped= 0;
 415   qu->interim_allocd= qu->preserved_allocd;
 416 }
 417
 418 static void free_query_allocs(adns_query qu) {
 419   allocnode *an, *ann;
 420
 421   cancel_children(qu);
 422   for (an= qu->allocations.head; an; an= ann) { ann= an->next; free(an); }
 423   LIST_INIT(qu->allocations);
 424   adns__vbuf_free(&qu->vb);
 425   adns__vbuf_free(&qu->search_vb);
 426   free(qu->query_dgram);
 427   qu->query_dgram= 0;
 428 }
 429
 430 void adns_cancel(adns_query qu) {
 431   adns_state ads;
 432
 433   ads= qu->ads;
 434   adns__consistency(ads,qu,cc_entex);
 435   if (qu->parent) LIST_UNLINK_PART(qu->parent->children,qu,siblings.);
 436   switch (qu->state) {
 437   case query_tosend:
 438     LIST_UNLINK(ads->udpw,qu);
 439     break;
 440   case query_tcpw:
 441     LIST_UNLINK(ads->tcpw,qu);
 442     break;
 443   case query_childw:
 444     LIST_UNLINK(ads->childw,qu);
 445     break;
 446   case query_done:
 447     LIST_UNLINK(ads->output,qu);
 448     break;
 449   default:
 450     abort();
 451   }
 452   free_query_allocs(qu);
 453   free(qu->answer);
 454   free(qu);
 455   adns__consistency(ads,0,cc_entex);
 456 }
 457
 458 void adns__update_expires(adns_query qu, unsigned long ttl, struct timeval now) {
 459   time_t max;
 460
 461   assert(ttl <= MAXTTLBELIEVE);
 462   max= now.tv_sec + ttl;
 463   if (qu->expires < max) return;
 464   qu->expires= max;
 465 }
 466
 467 static void makefinal_query(adns_query qu) {
 468   adns_answer *ans;
 469   int rrn;
 470
 471   ans= qu->answer;
 472
 473   if (qu->interim_allocd) {
 474     ans= realloc(qu->answer, MEM_ROUND(MEM_ROUND(sizeof(*ans)) + qu->interim_allocd));
 475     if (!ans) goto x_nomem;
 476     qu->answer= ans;
 477   }
 478
 479   qu->final_allocspace= (byte*)ans + MEM_ROUND(sizeof(*ans));
 480   adns__makefinal_str(qu,&ans->cname);
 481   adns__makefinal_str(qu,&ans->owner);
 482
 483   if (ans->nrrs) {
 484     adns__makefinal_block(qu, &ans->rrs.untyped, (size_t) ans->nrrs*ans->rrsz);
 485
 486     for (rrn=0; rrn<ans->nrrs; rrn++)
 487       qu->typei->makefinal(qu, ans->rrs.bytes + rrn*ans->rrsz);
 488   }
 489
 490   free_query_allocs(qu);
 491   return;
 492
 493  x_nomem:
 494   qu->preserved_allocd= 0;
 495   qu->answer->cname= 0;
 496   qu->answer->owner= 0;
 497   adns__reset_preserved(qu); /* (but we just threw away the preserved stuff) */
 498
 499   qu->answer->status= adns_s_nomemory;
 500   free_query_allocs(qu);
 501 }
 502
 503 void adns__query_done(adns_query qu) {
 504   adns_answer *ans;
 505   adns_query parent;
 506
 507   cancel_children(qu);
 508
 509   qu->id= -1;
 510   ans= qu->answer;
 511
 512   if (qu->flags & adns_qf_owner && qu->flags & adns_qf_search &&
 513       ans->status != adns_s_nomemory) {
 514     if (!save_owner(qu, (char*)qu->search_vb.buf, qu->search_vb.used)) {
 515       adns__query_fail(qu,adns_s_nomemory);
 516       return;
 517     }
 518   }
 519
 520   if (ans->nrrs && qu->typei->diff_needswap) {
 521     if (!adns__vbuf_ensure(&qu->vb,qu->typei->rrsz)) {
 522       adns__query_fail(qu,adns_s_nomemory);
 523       return;
 524     }
 525     adns__isort(ans->rrs.bytes, ans->nrrs, ans->rrsz,
 526                 qu->vb.buf,
 527                 (int(*)(void*, const void*, const void*))qu->typei->diff_needswap,
 528                 qu->ads);
 529   }
 530
 531   ans->expires= qu->expires;
 532   parent= qu->parent;
 533   if (parent) {
 534     LIST_UNLINK_PART(parent->children,qu,siblings.);
 535     LIST_UNLINK(qu->ads->childw,parent);
 536     qu->ctx.callback(parent,qu);
 537     free_query_allocs(qu);
 538     free(qu->answer);
 539     free(qu);
 540   } else {
 541     makefinal_query(qu);
 542     LIST_LINK_TAIL(qu->ads->output,qu);
 543     qu->state= query_done;
 544   }
 545 }
 546
 547 void adns__query_fail(adns_query qu, adns_status stat) {
 548   adns__reset_preserved(qu);
 549   qu->answer->status= stat;
 550   adns__query_done(qu);
 551 }
 552
 553 void adns__makefinal_str(adns_query qu, char **strp) {
 554   int l;
 555   char *before, *after;
 556
 557   before= *strp;
 558   if (!before) return;
 559   l= strlen(before)+1;
 560   after= adns__alloc_final(qu, (size_t) l);
 561   memcpy(after,before,(size_t) l);
 562   *strp= after;
 563 }
 564
 565 void adns__makefinal_block(adns_query qu, void **blpp, size_t sz) {
 566   void *before, *after;
 567
 568   before= *blpp;
 569   if (!before) return;
 570   after= adns__alloc_final(qu,sz);
 571   memcpy(after,before, (size_t) sz);
 572   *blpp= after;
 573 }