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->retries= 0;
  72   qu->udpnextserver= 0;
  73   qu->udpsent= 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.  Takes over the memory for qumsg_vb.
  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_new;
 131   int id;
 132   adns_status stat;
 133
 134   stat= adns__mkquery(ads,&qu->vb,&id, owner,ol, typei,flags);
 135   if (stat) {
 136     if (stat == adns_s_querydomaintoolong && (flags & adns_qf_search)) {
 137       adns__search_next(ads,qu,now);
 138       return;
 139     } else {
 140       adns__query_fail(qu,stat);
 141       return;
 142     }
 143   }
 144
 145   vb_new= qu->vb;
 146   adns__vbuf_init(&qu->vb);
 147   query_submit(ads,qu, typei,&vb_new,id, flags,now);
 148 }
 149
 150 void adns__search_next(adns_state ads, adns_query qu, struct timeval now) {
 151   const char *nextentry;
 152   adns_status stat;
 153
 154   if (qu->search_doneabs<0) {
 155     nextentry= 0;
 156     qu->search_doneabs= 1;
 157   } else {
 158     if (qu->search_pos >= ads->nsearchlist) {
 159       if (qu->search_doneabs) {
 160         stat= adns_s_nxdomain; goto x_fail;
 161         return;
 162       } else {
 163         nextentry= 0;
 164         qu->search_doneabs= 1;
 165       }
 166     } else {
 167       nextentry= ads->searchlist[qu->search_pos++];
 168     }
 169   }
 170
 171   qu->search_vb.used= qu->search_origlen;
 172   if (nextentry) {
 173     if (!adns__vbuf_append(&qu->search_vb,".",1) ||
 174         !adns__vbuf_appendstr(&qu->search_vb,nextentry)) {
 175       stat= adns_s_nomemory; goto x_fail;
 176     }
 177   }
 178
 179   free(qu->query_dgram);
 180   qu->query_dgram= 0; qu->query_dglen= 0;
 181
 182   query_simple(ads,qu, qu->search_vb.buf, qu->search_vb.used, qu->typei, qu->flags, now);
 183   return;
 184
 185 x_fail:
 186   adns__query_fail(qu,stat);
 187 }
 188
 189 static int save_owner(adns_query qu, const char *owner, int ol) {
 190   /* Returns 1 if OK, otherwise there was no memory. */
 191   adns_answer *ans;
 192
 193   ans= qu->answer;
 194   assert(!ans->owner);
 195
 196   ans->owner= adns__alloc_preserved(qu,ol+1);  if (!ans->owner) return 0;
 197
 198   memcpy(ans->owner,owner,ol);
 199   ans->owner[ol]= 0;
 200   return 1;
 201 }
 202
 203 int adns_submit(adns_state ads,
 204                 const char *owner,
 205                 adns_rrtype type,
 206                 adns_queryflags flags,
 207                 void *context,
 208                 adns_query *query_r) {
 209   int r, ol, ndots;
 210   adns_status stat;
 211   const typeinfo *typei;
 212   struct timeval now;
 213   adns_query qu;
 214   const char *p;
 215
 216   adns__consistency(ads,0,cc_entex);
 217
 218   typei= adns__findtype(type);
 219   if (!typei) return ENOSYS;
 220
 221   r= gettimeofday(&now,0); if (r) goto x_errno;
 222   qu= query_alloc(ads,typei,flags,now); if (!qu) goto x_errno;
 223
 224   qu->ctx.ext= context;
 225   qu->ctx.callback= 0;
 226   memset(&qu->ctx.info,0,sizeof(qu->ctx.info));
 227
 228   *query_r= qu;
 229
 230   ol= strlen(owner);
 231   if (!ol) { stat= adns_s_querydomaininvalid; goto x_adnsfail; }
 232   if (ol>DNS_MAXDOMAIN+1) { stat= adns_s_querydomaintoolong; goto x_adnsfail; }
 233
 234   if (ol>=1 && owner[ol-1]=='.' && (ol<2 || owner[ol-2]!='\\')) {
 235     flags &= ~adns_qf_search;
 236     qu->flags= flags;
 237     ol--;
 238   }
 239
 240   if (flags & adns_qf_search) {
 241     r= adns__vbuf_append(&qu->search_vb,owner,ol);
 242     if (!r) { stat= adns_s_nomemory; goto x_adnsfail; }
 243
 244     for (ndots=0, p=owner; (p= strchr(p,'.')); p++, ndots++);
 245     qu->search_doneabs= (ndots >= ads->searchndots) ? -1 : 0;
 246     qu->search_origlen= ol;
 247     adns__search_next(ads,qu,now);
 248   } else {
 249     if (flags & adns_qf_owner) {
 250       if (!save_owner(qu,owner,ol)) { stat= adns_s_nomemory; goto x_adnsfail; }
 251     }
 252     query_simple(ads,qu, owner,ol, typei,flags, now);
 253   }
 254   adns__autosys(ads,now);
 255   adns__consistency(ads,qu,cc_entex);
 256   return 0;
 257
 258  x_adnsfail:
 259   adns__query_fail(qu,stat);
 260   adns__consistency(ads,qu,cc_entex);
 261   return 0;
 262
 263  x_errno:
 264   r= errno;
 265   assert(r);
 266   adns__consistency(ads,0,cc_entex);
 267   return r;
 268 }
 269
 270 int adns_submit_reverse(adns_state ads,
 271                         const struct sockaddr *addr,
 272                         adns_rrtype type,
 273                         adns_queryflags flags,
 274                         void *context,
 275                         adns_query *query_r) {
 276   const unsigned char *iaddr;
 277   char buf[30];
 278
 279   if (type != adns_r_ptr && type != adns_r_ptr_raw) return EINVAL;
 280   flags &= ~adns_qf_search;
 281
 282   if (addr->sa_family != AF_INET) return ENOSYS;
 283   iaddr= (const unsigned char*) &(((const struct sockaddr_in*)addr) -> sin_addr);
 284
 285   sprintf(buf, "%d.%d.%d.%d.in-addr.arpa",
 286           iaddr[3], iaddr[2], iaddr[1], iaddr[0]);
 287
 288   return adns_submit(ads,buf,type,flags,context,query_r);
 289 }
 290
 291 int adns_synchronous(adns_state ads,
 292                      const char *owner,
 293                      adns_rrtype type,
 294                      adns_queryflags flags,
 295                      adns_answer **answer_r) {
 296   adns_query qu;
 297   int r;
 298
 299   r= adns_submit(ads,owner,type,flags,0,&qu);
 300   if (r) return r;
 301
 302   r= adns_wait(ads,&qu,answer_r,0);
 303   if (r) adns_cancel(qu);
 304
 305   return r;
 306 }
 307
 308 static void *alloc_common(adns_query qu, size_t sz) {
 309   allocnode *an;
 310
 311   if (!sz) return qu; /* Any old pointer will do */
 312   assert(!qu->final_allocspace);
 313   an= malloc(MEM_ROUND(MEM_ROUND(sizeof(*an)) + sz));
 314   if (!an) return 0;
 315   LIST_LINK_TAIL(qu->allocations,an);
 316   return (byte*)an + MEM_ROUND(sizeof(*an));
 317 }
 318
 319 void *adns__alloc_interim(adns_query qu, size_t sz) {
 320   void *rv;
 321
 322   sz= MEM_ROUND(sz);
 323   rv= alloc_common(qu,sz);
 324   if (!rv) return 0;
 325   qu->interim_allocd += sz;
 326   return rv;
 327 }
 328
 329 void *adns__alloc_preserved(adns_query qu, size_t sz) {
 330   void *rv;
 331
 332   sz= MEM_ROUND(sz);
 333   rv= adns__alloc_interim(qu,sz);
 334   if (!rv) return 0;
 335   qu->preserved_allocd += sz;
 336   return rv;
 337 }
 338
 339 void *adns__alloc_mine(adns_query qu, size_t sz) {
 340   return alloc_common(qu,MEM_ROUND(sz));
 341 }
 342
 343 void adns__transfer_interim(adns_query from, adns_query to, void *block, size_t sz) {
 344   allocnode *an;
 345
 346   if (!block) return;
 347   an= (void*)((byte*)block - MEM_ROUND(sizeof(*an)));
 348
 349   assert(!to->final_allocspace);
 350   assert(!from->final_allocspace);
 351
 352   LIST_UNLINK(from->allocations,an);
 353   LIST_LINK_TAIL(to->allocations,an);
 354
 355   from->interim_allocd -= sz;
 356   to->interim_allocd += sz;
 357
 358   if (to->expires > from->expires) to->expires= from->expires;
 359 }
 360
 361 void *adns__alloc_final(adns_query qu, size_t sz) {
 362   /* When we're in the _final stage, we _subtract_ from interim_alloc'd
 363    * each allocation, and use final_allocspace to point to the next free
 364    * bit.
 365    */
 366   void *rp;
 367
 368   sz= MEM_ROUND(sz);
 369   rp= qu->final_allocspace;
 370   assert(rp);
 371   qu->interim_allocd -= sz;
 372   assert(qu->interim_allocd>=0);
 373   qu->final_allocspace= (byte*)rp + sz;
 374   return rp;
 375 }
 376
 377 static void cancel_children(adns_query qu) {
 378   adns_query cqu, ncqu;
 379
 380   for (cqu= qu->children.head; cqu; cqu= ncqu) {
 381     ncqu= cqu->siblings.next;
 382     adns_cancel(cqu);
 383   }
 384 }
 385
 386 void adns__reset_preserved(adns_query qu) {
 387   assert(!qu->final_allocspace);
 388   cancel_children(qu);
 389   qu->answer->nrrs= 0;
 390   qu->answer->rrs.untyped= 0;
 391   qu->interim_allocd= qu->preserved_allocd;
 392 }
 393
 394 static void free_query_allocs(adns_query qu) {
 395   allocnode *an, *ann;
 396
 397   cancel_children(qu);
 398   for (an= qu->allocations.head; an; an= ann) { ann= an->next; free(an); }
 399   LIST_INIT(qu->allocations);
 400   adns__vbuf_free(&qu->vb);
 401   adns__vbuf_free(&qu->search_vb);
 402   free(qu->query_dgram);
 403 }
 404
 405 void adns_cancel(adns_query qu) {
 406   adns_state ads;
 407
 408   ads= qu->ads;
 409   adns__consistency(ads,qu,cc_entex);
 410   if (qu->parent) LIST_UNLINK_PART(qu->parent->children,qu,siblings.);
 411   switch (qu->state) {
 412   case query_tosend:
 413     LIST_UNLINK(ads->udpw,qu);
 414     break;
 415   case query_tcpw:
 416     LIST_UNLINK(ads->tcpw,qu);
 417     break;
 418   case query_childw:
 419     LIST_UNLINK(ads->childw,qu);
 420     break;
 421   case query_done:
 422     LIST_UNLINK(ads->output,qu);
 423     break;
 424   default:
 425     abort();
 426   }
 427   free_query_allocs(qu);
 428   free(qu->answer);
 429   free(qu);
 430   adns__consistency(ads,0,cc_entex);
 431 }
 432
 433 void adns__update_expires(adns_query qu, unsigned long ttl, struct timeval now) {
 434   time_t max;
 435
 436   assert(ttl <= MAXTTLBELIEVE);
 437   max= now.tv_sec + ttl;
 438   if (qu->expires < max) return;
 439   qu->expires= max;
 440 }
 441
 442 static void makefinal_query(adns_query qu) {
 443   adns_answer *ans;
 444   int rrn;
 445
 446   ans= qu->answer;
 447
 448   if (qu->interim_allocd) {
 449     ans= realloc(qu->answer, MEM_ROUND(MEM_ROUND(sizeof(*ans)) + qu->interim_allocd));
 450     if (!ans) goto x_nomem;
 451     qu->answer= ans;
 452   }
 453
 454   qu->final_allocspace= (byte*)ans + MEM_ROUND(sizeof(*ans));
 455   adns__makefinal_str(qu,&ans->cname);
 456   adns__makefinal_str(qu,&ans->owner);
 457
 458   if (ans->nrrs) {
 459     adns__makefinal_block(qu, &ans->rrs.untyped, ans->nrrs*ans->rrsz);
 460
 461     for (rrn=0; rrn<ans->nrrs; rrn++)
 462       qu->typei->makefinal(qu, ans->rrs.bytes + rrn*ans->rrsz);
 463   }
 464
 465   free_query_allocs(qu);
 466   return;
 467
 468  x_nomem:
 469   qu->preserved_allocd= 0;
 470   qu->answer->cname= 0;
 471   qu->answer->owner= 0;
 472   adns__reset_preserved(qu); /* (but we just threw away the preserved stuff) */
 473
 474   qu->answer->status= adns_s_nomemory;
 475   free_query_allocs(qu);
 476 }
 477
 478 void adns__query_done(adns_query qu) {
 479   adns_answer *ans;
 480   adns_query parent;
 481
 482   cancel_children(qu);
 483
 484   qu->id= -1;
 485   ans= qu->answer;
 486
 487   if (qu->flags & adns_qf_owner && qu->flags & adns_qf_search &&
 488       ans->status != adns_s_nomemory) {
 489     if (!save_owner(qu, qu->search_vb.buf, qu->search_vb.used)) {
 490       adns__query_fail(qu,adns_s_nomemory);
 491       return;
 492     }
 493   }
 494
 495   if (ans->nrrs && qu->typei->diff_needswap) {
 496     if (!adns__vbuf_ensure(&qu->vb,qu->typei->rrsz)) {
 497       adns__query_fail(qu,adns_s_nomemory);
 498       return;
 499     }
 500     adns__isort(ans->rrs.bytes, ans->nrrs, ans->rrsz,
 501                 qu->vb.buf,
 502                 (int(*)(void*, const void*, const void*))qu->typei->diff_needswap,
 503                 qu->ads);
 504   }
 505
 506   ans->expires= qu->expires;
 507   parent= qu->parent;
 508   if (parent) {
 509     LIST_UNLINK_PART(parent->children,qu,siblings.);
 510     LIST_UNLINK(qu->ads->childw,parent);
 511     qu->ctx.callback(parent,qu);
 512     free_query_allocs(qu);
 513     free(qu->answer);
 514     free(qu);
 515   } else {
 516     makefinal_query(qu);
 517     LIST_LINK_TAIL(qu->ads->output,qu);
 518     qu->state= query_done;
 519   }
 520 }
 521
 522 void adns__query_fail(adns_query qu, adns_status stat) {
 523   adns__reset_preserved(qu);
 524   qu->answer->status= stat;
 525   adns__query_done(qu);
 526 }
 527
 528 void adns__makefinal_str(adns_query qu, char **strp) {
 529   int l;
 530   char *before, *after;
 531
 532   before= *strp;
 533   if (!before) return;
 534   l= strlen(before)+1;
 535   after= adns__alloc_final(qu,l);
 536   memcpy(after,before,l);
 537   *strp= after;
 538 }
 539
 540 void adns__makefinal_block(adns_query qu, void **blpp, size_t sz) {
 541   void *before, *after;
 542
 543   before= *blpp;
 544   if (!before) return;
 545   after= adns__alloc_final(qu,sz);
 546   memcpy(after,before,sz);
 547   *blpp= after;
 548 }