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
   9  *    Copyright (C) 1997-1999 Ian Jackson <ian@davenant.greenend.org.uk>
  10  *
  11  *  It is part of adns, which is
  12  *    Copyright (C) 1997-1999 Ian Jackson <ian@davenant.greenend.org.uk>
  13  *    Copyright (C) 1999 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 #include "internal.h"
  31
  32 #include <stdlib.h>
  33 #include <unistd.h>
  34 #include <errno.h>
  35
  36 #include <sys/time.h>
  37
  38 #include "internal.h"
  39
  40 static adns_query query_alloc(adns_state ads, const typeinfo *typei,
  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));  if (!qu->answer) { free(qu); return 0; }
  47
  48   qu->ads= ads;
  49   qu->state= query_tosend;
  50   qu->back= qu->next= qu->parent= 0;
  51   LIST_INIT(qu->children);
  52   LINK_INIT(qu->siblings);
  53   LIST_INIT(qu->allocations);
  54   qu->interim_allocd= 0;
  55   qu->preserved_allocd= 0;
  56   qu->final_allocspace= 0;
  57
  58   qu->typei= typei;
  59   qu->query_dgram= 0;
  60   qu->query_dglen= 0;
  61   adns__vbuf_init(&qu->vb);
  62
  63   qu->cname_dgram= 0;
  64   qu->cname_dglen= qu->cname_begin= 0;
  65
  66   adns__vbuf_init(&qu->search_vb);
  67   qu->search_origlen= qu->search_pos= qu->search_doneabs= 0;
  68
  69   qu->id= 0;
  70   qu->flags= flags;
  71   qu->udpretries= 0;
  72   qu->udpnextserver= 0;
  73   qu->udpsent= qu->tcpfailed= 0;
  74   timerclear(&qu->timeout);
  75   qu->expires= now.tv_sec + MAXTTLBELIEVE;
  76
  77   memset(&qu->ctx,0,sizeof(qu->ctx));
  78
  79   qu->answer->status= adns_s_ok;
  80   qu->answer->cname= qu->answer->owner= 0;
  81   qu->answer->type= typei->type;
  82   qu->answer->expires= -1;
  83   qu->answer->nrrs= 0;
  84   qu->answer->rrs.untyped= 0;
  85   qu->answer->rrsz= typei->rrsz;
  86
  87   return qu;
  88 }
  89
  90 static void query_submit(adns_state ads, adns_query qu,
  91                          const typeinfo *typei, vbuf *qumsg_vb, int id,
  92                          adns_queryflags flags, struct timeval now) {
  93   /* Fills in the query message in for a previously-allocated query,
  94    * and submits it.  Cannot fail.
  95    */
  96
  97   qu->vb= *qumsg_vb;
  98   adns__vbuf_init(qumsg_vb);
  99
 100   qu->query_dgram= malloc(qu->vb.used);
 101   if (!qu->query_dgram) { adns__query_fail(qu,adns_s_nomemory); return; }
 102
 103   qu->id= id;
 104   qu->query_dglen= qu->vb.used;
 105   memcpy(qu->query_dgram,qu->vb.buf,qu->vb.used);
 106
 107   adns__query_send(qu,now);
 108 }
 109
 110 adns_status adns__internal_submit(adns_state ads, adns_query *query_r,
 111                                   const typeinfo *typei, vbuf *qumsg_vb, int id,
 112                                   adns_queryflags flags, struct timeval now,
 113                                   const qcontext *ctx) {
 114   adns_query qu;
 115
 116   qu= query_alloc(ads,typei,flags,now);
 117   if (!qu) { adns__vbuf_free(qumsg_vb); return adns_s_nomemory; }
 118   *query_r= qu;
 119
 120   memcpy(&qu->ctx,ctx,sizeof(qu->ctx));
 121   query_submit(ads,qu, typei,qumsg_vb,id,flags,now);
 122
 123   return adns_s_ok;
 124 }
 125
 126 static void query_simple(adns_state ads, adns_query qu,
 127                          const char *owner, int ol,
 128                          const typeinfo *typei, adns_queryflags flags,
 129                          struct timeval now) {
 130   vbuf vb;
 131   int id;
 132   adns_status stat;
 133
 134   adns__vbuf_init(&vb);
 135
 136   stat= adns__mkquery(ads,&vb,&id, owner,ol, typei,flags);
 137   if (stat) { adns__query_fail(qu,stat); return; }
 138
 139   query_submit(ads,qu, typei,&vb,id, flags,now);
 140 }
 141
 142 void adns__search_next(adns_state ads, adns_query qu, struct timeval now) {
 143   const char *nextentry;
 144   adns_status stat;
 145
 146   if (qu->search_doneabs<0) {
 147     nextentry= 0;
 148     qu->search_doneabs= 1;
 149   } else {
 150     if (qu->search_pos >= ads->nsearchlist) {
 151       if (qu->search_doneabs) {
 152         stat= adns_s_nxdomain; goto x_fail;
 153         return;
 154       } else {
 155         nextentry= 0;
 156         qu->search_doneabs= 1;
 157       }
 158     } else {
 159       nextentry= ads->searchlist[qu->search_pos++];
 160     }
 161   }
 162
 163   qu->search_vb.used= qu->search_origlen;
 164   if (nextentry) {
 165     if (!adns__vbuf_append(&qu->search_vb,".",1) ||
 166         !adns__vbuf_appendstr(&qu->search_vb,nextentry)) {
 167       stat= adns_s_nomemory; goto x_fail;
 168     }
 169   }
 170
 171   free(qu->query_dgram);
 172   qu->query_dgram= 0; qu->query_dglen= 0;
 173
 174   query_simple(ads,qu, qu->search_vb.buf, qu->search_vb.used, qu->typei, qu->flags, now);
 175   return;
 176
 177 x_fail:
 178   adns__query_fail(qu,stat);
 179 }
 180
 181 static int save_owner(adns_query qu, const char *owner, int ol) {
 182   /* Returns 1 if OK, otherwise there was no memory. */
 183   adns_answer *ans;
 184
 185   ans= qu->answer;
 186   assert(!ans->owner);
 187
 188   ans->owner= adns__alloc_preserved(qu,ol+1);  if (!ans->owner) return 0;
 189
 190   memcpy(ans->owner,owner,ol);
 191   ans->owner[ol]= 0;
 192   return 1;
 193 }
 194
 195 int adns_submit(adns_state ads,
 196                 const char *owner,
 197                 adns_rrtype type,
 198                 int flags,
 199                 void *context,
 200                 adns_query *query_r) {
 201   int r, ol, ndots;
 202   adns_status stat;
 203   const typeinfo *typei;
 204   struct timeval now;
 205   adns_query qu;
 206   const char *p;
 207
 208   adns__consistency(ads,0,cc_entex);
 209
 210   typei= adns__findtype(type);
 211   if (!typei) return ENOSYS;
 212
 213   r= gettimeofday(&now,0); if (r) goto x_errno;
 214   qu= query_alloc(ads,typei,flags,now); if (!qu) goto x_errno;
 215
 216   qu->ctx.ext= context;
 217   qu->ctx.callback= 0;
 218   memset(&qu->ctx.info,0,sizeof(qu->ctx.info));
 219
 220   *query_r= qu;
 221
 222   ol= strlen(owner);
 223   if (!ol) { stat= adns_s_querydomaininvalid; goto x_adnsfail; }
 224   if (ol>DNS_MAXDOMAIN+1) { stat= adns_s_querydomaintoolong; goto x_adnsfail; }
 225
 226   if (ol>=1 && owner[ol-1]=='.' && (ol<2 || owner[ol-2]!='\\')) {
 227     flags &= ~adns_qf_search;
 228     qu->flags= flags;
 229     ol--;
 230   }
 231
 232   if (flags & adns_qf_search) {
 233     r= adns__vbuf_append(&qu->search_vb,owner,ol);
 234     if (!r) { stat= adns_s_nomemory; goto x_adnsfail; }
 235
 236     for (ndots=0, p=owner; (p= strchr(p,'.')); p++, ndots++);
 237     qu->search_doneabs= (ndots >= ads->searchndots) ? -1 : 0;
 238     qu->search_origlen= ol;
 239     adns__search_next(ads,qu,now);
 240   } else {
 241     if (flags & adns_qf_owner) {
 242       if (!save_owner(qu,owner,ol)) { stat= adns_s_nomemory; goto x_adnsfail; }
 243     }
 244     query_simple(ads,qu, owner,ol, typei,flags, now);
 245   }
 246   adns__autosys(ads,now);
 247   adns__consistency(ads,qu,cc_entex);
 248   return 0;
 249
 250  x_adnsfail:
 251   adns__query_fail(qu,stat);
 252   adns__consistency(ads,qu,cc_entex);
 253   return 0;
 254
 255  x_errno:
 256   r= errno;
 257   assert(r);
 258   adns__consistency(ads,0,cc_entex);
 259   return r;
 260 }
 261
 262 int adns_submit_reverse(adns_state ads,
 263                         const struct sockaddr *addr,
 264                         adns_rrtype type,
 265                         int flags,
 266                         void *context,
 267                         adns_query *query_r) {
 268   const unsigned char *iaddr;
 269   char buf[30];
 270
 271   if (type != adns_r_ptr && type != adns_r_ptr_raw) return EINVAL;
 272   flags &= ~adns_qf_search;
 273
 274   if (addr->sa_family != AF_INET) return ENOSYS;
 275   iaddr= (const unsigned char*) &(((const struct sockaddr_in*)addr) -> sin_addr);
 276
 277   sprintf(buf, "%d.%d.%d.%d.in-addr.arpa",
 278           iaddr[3], iaddr[2], iaddr[1], iaddr[0]);
 279
 280   return adns_submit(ads,buf,type,flags,context,query_r);
 281 }
 282
 283 int adns_synchronous(adns_state ads,
 284                      const char *owner,
 285                      adns_rrtype type,
 286                      int flags,
 287                      adns_answer **answer_r) {
 288   adns_query qu;
 289   int r;
 290
 291   r= adns_submit(ads,owner,type,flags,0,&qu);
 292   if (r) return r;
 293
 294   r= adns_wait(ads,&qu,answer_r,0);
 295   if (r) adns_cancel(qu);
 296
 297   return r;
 298 }
 299
 300 static void *alloc_common(adns_query qu, size_t sz) {
 301   allocnode *an;
 302
 303   if (!sz) return qu; /* Any old pointer will do */
 304   assert(!qu->final_allocspace);
 305   an= malloc(MEM_ROUND(MEM_ROUND(sizeof(*an)) + sz));
 306   if (!an) return 0;
 307   LIST_LINK_TAIL(qu->allocations,an);
 308   return (byte*)an + MEM_ROUND(sizeof(*an));
 309 }
 310
 311 void *adns__alloc_interim(adns_query qu, size_t sz) {
 312   void *rv;
 313
 314   sz= MEM_ROUND(sz);
 315   rv= alloc_common(qu,sz);
 316   if (!rv) return 0;
 317   qu->interim_allocd += sz;
 318   return rv;
 319 }
 320
 321 void *adns__alloc_preserved(adns_query qu, size_t sz) {
 322   void *rv;
 323
 324   sz= MEM_ROUND(sz);
 325   rv= adns__alloc_interim(qu,sz);
 326   if (!rv) return 0;
 327   qu->preserved_allocd += sz;
 328   return rv;
 329 }
 330
 331 void *adns__alloc_mine(adns_query qu, size_t sz) {
 332   return alloc_common(qu,MEM_ROUND(sz));
 333 }
 334
 335 void adns__transfer_interim(adns_query from, adns_query to, void *block, size_t sz) {
 336   allocnode *an;
 337
 338   if (!block) return;
 339   an= (void*)((byte*)block - MEM_ROUND(sizeof(*an)));
 340
 341   assert(!to->final_allocspace);
 342   assert(!from->final_allocspace);
 343
 344   LIST_UNLINK(from->allocations,an);
 345   LIST_LINK_TAIL(to->allocations,an);
 346
 347   from->interim_allocd -= sz;
 348   to->interim_allocd += sz;
 349
 350   if (to->expires > from->expires) to->expires= from->expires;
 351 }
 352
 353 void *adns__alloc_final(adns_query qu, size_t sz) {
 354   /* When we're in the _final stage, we _subtract_ from interim_alloc'd
 355    * each allocation, and use final_allocspace to point to the next free
 356    * bit.
 357    */
 358   void *rp;
 359
 360   sz= MEM_ROUND(sz);
 361   rp= qu->final_allocspace;
 362   assert(rp);
 363   qu->interim_allocd -= sz;
 364   assert(qu->interim_allocd>=0);
 365   qu->final_allocspace= (byte*)rp + sz;
 366   return rp;
 367 }
 368
 369 static void cancel_children(adns_query qu) {
 370   adns_query cqu, ncqu;
 371
 372   for (cqu= qu->children.head; cqu; cqu= ncqu) {
 373     ncqu= cqu->siblings.next;
 374     adns_cancel(cqu);
 375   }
 376 }
 377
 378 void adns__reset_preserved(adns_query qu) {
 379   assert(!qu->final_allocspace);
 380   cancel_children(qu);
 381   qu->answer->nrrs= 0;
 382   qu->answer->rrs.untyped= 0;
 383   qu->interim_allocd= qu->preserved_allocd;
 384 }
 385
 386 static void free_query_allocs(adns_query qu) {
 387   allocnode *an, *ann;
 388
 389   cancel_children(qu);
 390   for (an= qu->allocations.head; an; an= ann) { ann= an->next; free(an); }
 391   LIST_INIT(qu->allocations);
 392   adns__vbuf_free(&qu->vb);
 393 }
 394
 395 void adns_cancel(adns_query qu) {
 396   adns_state ads;
 397
 398   ads= qu->ads;
 399   adns__consistency(ads,qu,cc_entex);
 400   if (qu->parent) LIST_UNLINK_PART(qu->parent->children,qu,siblings.);
 401   switch (qu->state) {
 402   case query_tosend: case query_tcpwait: case query_tcpsent:
 403     LIST_UNLINK(ads->timew,qu);
 404     break;
 405   case query_child:
 406     LIST_UNLINK(ads->childw,qu);
 407     break;
 408   case query_done:
 409     LIST_UNLINK(ads->output,qu);
 410     break;
 411   default:
 412     abort();
 413   }
 414   free_query_allocs(qu);
 415   free(qu->answer);
 416   free(qu);
 417   adns__consistency(ads,0,cc_entex);
 418 }
 419
 420 void adns__update_expires(adns_query qu, unsigned long ttl, struct timeval now) {
 421   time_t max;
 422
 423   assert(ttl <= MAXTTLBELIEVE);
 424   max= now.tv_sec + ttl;
 425   if (qu->expires < max) return;
 426   qu->expires= max;
 427 }
 428
 429 static void makefinal_query(adns_query qu) {
 430   adns_answer *ans;
 431   int rrn;
 432
 433   ans= qu->answer;
 434
 435   if (qu->interim_allocd) {
 436     ans= realloc(qu->answer, MEM_ROUND(MEM_ROUND(sizeof(*ans)) + qu->interim_allocd));
 437     if (!ans) goto x_nomem;
 438     qu->answer= ans;
 439   }
 440
 441   qu->final_allocspace= (byte*)ans + MEM_ROUND(sizeof(*ans));
 442   adns__makefinal_str(qu,&ans->cname);
 443   adns__makefinal_str(qu,&ans->owner);
 444
 445   if (ans->nrrs) {
 446     adns__makefinal_block(qu, &ans->rrs.untyped, ans->nrrs*ans->rrsz);
 447
 448     for (rrn=0; rrn<ans->nrrs; rrn++)
 449       qu->typei->makefinal(qu, ans->rrs.bytes + rrn*ans->rrsz);
 450   }
 451
 452   free_query_allocs(qu);
 453   return;
 454
 455  x_nomem:
 456   qu->preserved_allocd= 0;
 457   qu->answer->cname= 0;
 458   qu->answer->owner= 0;
 459   adns__reset_preserved(qu); /* (but we just threw away the preserved stuff) */
 460
 461   qu->answer->status= adns_s_nomemory;
 462   free_query_allocs(qu);
 463 }
 464
 465 void adns__query_done(adns_query qu) {
 466   adns_answer *ans;
 467   adns_query parent;
 468
 469   cancel_children(qu);
 470
 471   qu->id= -1;
 472   ans= qu->answer;
 473
 474   if (qu->flags & adns_qf_owner && qu->flags & adns_qf_search &&
 475       ans->status != adns_s_nomemory) {
 476     if (!save_owner(qu, qu->search_vb.buf, qu->search_vb.used)) {
 477       adns__query_fail(qu,adns_s_nomemory);
 478       return;
 479     }
 480   }
 481
 482   if (ans->nrrs && qu->typei->diff_needswap) {
 483     if (!adns__vbuf_ensure(&qu->vb,qu->typei->rrsz)) {
 484       adns__query_fail(qu,adns_s_nomemory);
 485       return;
 486     }
 487     adns__isort(ans->rrs.bytes, ans->nrrs, ans->rrsz,
 488                 qu->vb.buf,
 489                 (int(*)(void*, const void*, const void*))qu->typei->diff_needswap,
 490                 qu->ads);
 491   }
 492
 493   ans->expires= qu->expires;
 494   parent= qu->parent;
 495   if (parent) {
 496     LIST_UNLINK_PART(parent->children,qu,siblings.);
 497     LIST_UNLINK(qu->ads->childw,parent);
 498     qu->ctx.callback(parent,qu);
 499     free_query_allocs(qu);
 500     free(qu);
 501   } else {
 502     makefinal_query(qu);
 503     LIST_LINK_TAIL(qu->ads->output,qu);
 504     qu->state= query_done;
 505   }
 506 }
 507
 508 void adns__query_fail(adns_query qu, adns_status stat) {
 509   adns__reset_preserved(qu);
 510   qu->answer->status= stat;
 511   adns__query_done(qu);
 512 }
 513
 514 void adns__makefinal_str(adns_query qu, char **strp) {
 515   int l;
 516   char *before, *after;
 517
 518   before= *strp;
 519   if (!before) return;
 520   l= strlen(before)+1;
 521   after= adns__alloc_final(qu,l);
 522   memcpy(after,before,l);
 523   *strp= after;
 524 }
 525
 526 void adns__makefinal_block(adns_query qu, void **blpp, size_t sz) {
 527   void *before, *after;
 528
 529   before= *blpp;
 530   if (!before) return;
 531   after= adns__alloc_final(qu,sz);
 532   memcpy(after,before,sz);
 533   *blpp= after;
 534 }