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) 1997-2000 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 #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));
  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= 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(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   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,
 113                                   int id,
 114                                   adns_queryflags flags, struct timeval now,
 115                                   const qcontext *ctx) {
 116   adns_query qu;
 117
 118   qu= query_alloc(ads,typei,flags,now);
 119   if (!qu) { adns__vbuf_free(qumsg_vb); return adns_s_nomemory; }
 120   *query_r= qu;
 121
 122   memcpy(&qu->ctx,ctx,sizeof(qu->ctx));
 123   query_submit(ads,qu, typei,qumsg_vb,id,flags,now);
 124
 125   return adns_s_ok;
 126 }
 127
 128 static void query_simple(adns_state ads, adns_query qu,
 129                          const char *owner, int ol,
 130                          const typeinfo *typei, adns_queryflags flags,
 131                          struct timeval now) {
 132   vbuf vb_new;
 133   int id;
 134   adns_status stat;
 135
 136   stat= adns__mkquery(ads,&qu->vb,&id, owner,ol, typei,flags);
 137   if (stat) {
 138     if (stat == adns_s_querydomaintoolong && (flags & adns_qf_search)) {
 139       adns__search_next(ads,qu,now);
 140       return;
 141     } else {
 142       adns__query_fail(qu,stat);
 143       return;
 144     }
 145   }
 146
 147   vb_new= qu->vb;
 148   adns__vbuf_init(&qu->vb);
 149   query_submit(ads,qu, typei,&vb_new,id, flags,now);
 150 }
 151
 152 void adns__search_next(adns_state ads, adns_query qu, struct timeval now) {
 153   const char *nextentry;
 154   adns_status stat;
 155
 156   if (qu->search_doneabs<0) {
 157     nextentry= 0;
 158     qu->search_doneabs= 1;
 159   } else {
 160     if (qu->search_pos >= ads->nsearchlist) {
 161       if (qu->search_doneabs) {
 162         qu->search_vb.used= qu->search_origlen;
 163         stat= adns_s_nxdomain; goto x_fail;
 164       } else {
 165         nextentry= 0;
 166         qu->search_doneabs= 1;
 167       }
 168     } else {
 169       nextentry= ads->searchlist[qu->search_pos++];
 170     }
 171   }
 172
 173   qu->search_vb.used= qu->search_origlen;
 174   if (nextentry) {
 175     if (!adns__vbuf_append(&qu->search_vb,".",1) ||
 176         !adns__vbuf_appendstr(&qu->search_vb,nextentry))
 177       goto x_nomemory;
 178   }
 179
 180   free(qu->query_dgram);
 181   qu->query_dgram= 0; qu->query_dglen= 0;
 182
 183   query_simple(ads,qu, qu->search_vb.buf, qu->search_vb.used,
 184                qu->typei, qu->flags, now);
 185   return;
 186
 187 x_nomemory:
 188   stat= adns_s_nomemory;
 189 x_fail:
 190   adns__query_fail(qu,stat);
 191 }
 192
 193 static int save_owner(adns_query qu, const char *owner, int ol) {
 194   /* Returns 1 if OK, otherwise there was no memory. */
 195   adns_answer *ans;
 196
 197   if (!(qu->flags & adns_qf_owner)) return 1;
 198
 199   ans= qu->answer;
 200   assert(!ans->owner);
 201
 202   ans->owner= adns__alloc_preserved(qu,ol+1);  if (!ans->owner) return 0;
 203
 204   memcpy(ans->owner,owner,ol);
 205   ans->owner[ol]= 0;
 206   return 1;
 207 }
 208
 209 int adns_submit(adns_state ads,
 210                 const char *owner,
 211                 adns_rrtype type,
 212                 adns_queryflags flags,
 213                 void *context,
 214                 adns_query *query_r) {
 215   int r, ol, ndots;
 216   adns_status stat;
 217   const typeinfo *typei;
 218   struct timeval now;
 219   adns_query qu;
 220   const char *p;
 221
 222   adns__consistency(ads,0,cc_entex);
 223
 224   typei= adns__findtype(type);
 225   if (!typei) return ENOSYS;
 226
 227   r= gettimeofday(&now,0); if (r) goto x_errno;
 228   qu= query_alloc(ads,typei,flags,now); if (!qu) goto x_errno;
 229
 230   qu->ctx.ext= context;
 231   qu->ctx.callback= 0;
 232   memset(&qu->ctx.info,0,sizeof(qu->ctx.info));
 233
 234   *query_r= qu;
 235
 236   ol= strlen(owner);
 237   if (!ol) { stat= adns_s_querydomaininvalid; goto x_adnsfail; }
 238   if (ol>DNS_MAXDOMAIN+1) { stat= adns_s_querydomaintoolong; goto x_adnsfail; }
 239
 240   if (ol>=1 && owner[ol-1]=='.' && (ol<2 || owner[ol-2]!='\\')) {
 241     flags &= ~adns_qf_search;
 242     qu->flags= flags;
 243     ol--;
 244   }
 245
 246   if (flags & adns_qf_search) {
 247     r= adns__vbuf_append(&qu->search_vb,owner,ol);
 248     if (!r) { stat= adns_s_nomemory; goto x_adnsfail; }
 249
 250     for (ndots=0, p=owner; (p= strchr(p,'.')); p++, ndots++);
 251     qu->search_doneabs= (ndots >= ads->searchndots) ? -1 : 0;
 252     qu->search_origlen= ol;
 253     adns__search_next(ads,qu,now);
 254   } else {
 255     if (flags & adns_qf_owner) {
 256       if (!save_owner(qu,owner,ol)) { stat= adns_s_nomemory; goto x_adnsfail; }
 257     }
 258     query_simple(ads,qu, owner,ol, typei,flags, now);
 259   }
 260   adns__autosys(ads,now);
 261   adns__consistency(ads,qu,cc_entex);
 262   return 0;
 263
 264  x_adnsfail:
 265   adns__query_fail(qu,stat);
 266   adns__consistency(ads,qu,cc_entex);
 267   return 0;
 268
 269  x_errno:
 270   r= errno;
 271   assert(r);
 272   adns__consistency(ads,0,cc_entex);
 273   return r;
 274 }
 275
 276 int adns_submit_reverse_any(adns_state ads,
 277                             const struct sockaddr *addr,
 278                             const char *zone,
 279                             adns_rrtype type,
 280                             adns_queryflags flags,
 281                             void *context,
 282                             adns_query *query_r) {
 283   const unsigned char *iaddr;
 284   char *buf, *buf_free;
 285   char shortbuf[100];
 286   int r, lreq;
 287
 288   flags &= ~adns_qf_search;
 289
 290   if (addr->sa_family != AF_INET) return ENOSYS;
 291   iaddr= (const unsigned char*)
 292     &(((const struct sockaddr_in*)addr) -> sin_addr);
 293
 294   lreq= strlen(zone) + 4*4 + 1;
 295   if (lreq > sizeof(shortbuf)) {
 296     buf= malloc(strlen(zone) + 4*4 + 1);
 297     if (!buf) return errno;
 298     buf_free= buf;
 299   } else {
 300     buf= shortbuf;
 301     buf_free= 0;
 302   }
 303   sprintf(buf, "%d.%d.%d.%d.%s", iaddr[3], iaddr[2], iaddr[1], iaddr[0], zone);
 304
 305   r= adns_submit(ads,buf,type,flags,context,query_r);
 306   free(buf_free);
 307   return r;
 308 }
 309
 310 int adns_submit_reverse(adns_state ads,
 311                         const struct sockaddr *addr,
 312                         adns_rrtype type,
 313                         adns_queryflags flags,
 314                         void *context,
 315                         adns_query *query_r) {
 316   if (type != adns_r_ptr && type != adns_r_ptr_raw) return EINVAL;
 317   return adns_submit_reverse_any(ads,addr,"in-addr.arpa",
 318                                  type,flags,context,query_r);
 319 }
 320
 321 int adns_synchronous(adns_state ads,
 322                      const char *owner,
 323                      adns_rrtype type,
 324                      adns_queryflags flags,
 325                      adns_answer **answer_r) {
 326   adns_query qu;
 327   int r;
 328
 329   r= adns_submit(ads,owner,type,flags,0,&qu);
 330   if (r) return r;
 331
 332   r= adns_wait(ads,&qu,answer_r,0);
 333   if (r) adns_cancel(qu);
 334
 335   return r;
 336 }
 337
 338 static void *alloc_common(adns_query qu, size_t sz) {
 339   allocnode *an;
 340
 341   if (!sz) return qu; /* Any old pointer will do */
 342   assert(!qu->final_allocspace);
 343   an= malloc(MEM_ROUND(MEM_ROUND(sizeof(*an)) + sz));
 344   if (!an) return 0;
 345   LIST_LINK_TAIL(qu->allocations,an);
 346   return (byte*)an + MEM_ROUND(sizeof(*an));
 347 }
 348
 349 void *adns__alloc_interim(adns_query qu, size_t sz) {
 350   void *rv;
 351
 352   sz= MEM_ROUND(sz);
 353   rv= alloc_common(qu,sz);
 354   if (!rv) return 0;
 355   qu->interim_allocd += sz;
 356   return rv;
 357 }
 358
 359 void *adns__alloc_preserved(adns_query qu, size_t sz) {
 360   void *rv;
 361
 362   sz= MEM_ROUND(sz);
 363   rv= adns__alloc_interim(qu,sz);
 364   if (!rv) return 0;
 365   qu->preserved_allocd += sz;
 366   return rv;
 367 }
 368
 369 void *adns__alloc_mine(adns_query qu, size_t sz) {
 370   return alloc_common(qu,MEM_ROUND(sz));
 371 }
 372
 373 void adns__transfer_interim(adns_query from, adns_query to,
 374                             void *block, size_t sz) {
 375   allocnode *an;
 376
 377   if (!block) return;
 378   an= (void*)((byte*)block - MEM_ROUND(sizeof(*an)));
 379
 380   assert(!to->final_allocspace);
 381   assert(!from->final_allocspace);
 382
 383   LIST_UNLINK(from->allocations,an);
 384   LIST_LINK_TAIL(to->allocations,an);
 385
 386   sz= MEM_ROUND(sz);
 387   from->interim_allocd -= sz;
 388   to->interim_allocd += sz;
 389
 390   if (to->expires > from->expires) to->expires= from->expires;
 391 }
 392
 393 void *adns__alloc_final(adns_query qu, size_t sz) {
 394   /* When we're in the _final stage, we _subtract_ from interim_alloc'd
 395    * each allocation, and use final_allocspace to point to the next free
 396    * bit.
 397    */
 398   void *rp;
 399
 400   sz= MEM_ROUND(sz);
 401   rp= qu->final_allocspace;
 402   assert(rp);
 403   qu->interim_allocd -= sz;
 404   assert(qu->interim_allocd>=0);
 405   qu->final_allocspace= (byte*)rp + sz;
 406   return rp;
 407 }
 408
 409 static void cancel_children(adns_query qu) {
 410   adns_query cqu, ncqu;
 411
 412   for (cqu= qu->children.head; cqu; cqu= ncqu) {
 413     ncqu= cqu->siblings.next;
 414     adns_cancel(cqu);
 415   }
 416 }
 417
 418 void adns__reset_preserved(adns_query qu) {
 419   assert(!qu->final_allocspace);
 420   cancel_children(qu);
 421   qu->answer->nrrs= 0;
 422   qu->answer->rrs.untyped= 0;
 423   qu->interim_allocd= qu->preserved_allocd;
 424 }
 425
 426 static void free_query_allocs(adns_query qu) {
 427   allocnode *an, *ann;
 428
 429   cancel_children(qu);
 430   for (an= qu->allocations.head; an; an= ann) { ann= an->next; free(an); }
 431   LIST_INIT(qu->allocations);
 432   adns__vbuf_free(&qu->vb);
 433   adns__vbuf_free(&qu->search_vb);
 434   free(qu->query_dgram);
 435   qu->query_dgram= 0;
 436 }
 437
 438 void adns_cancel(adns_query qu) {
 439   adns_state ads;
 440
 441   ads= qu->ads;
 442   adns__consistency(ads,qu,cc_entex);
 443   if (qu->parent) LIST_UNLINK_PART(qu->parent->children,qu,siblings.);
 444   switch (qu->state) {
 445   case query_tosend:
 446     LIST_UNLINK(ads->udpw,qu);
 447     break;
 448   case query_tcpw:
 449     LIST_UNLINK(ads->tcpw,qu);
 450     break;
 451   case query_childw:
 452     LIST_UNLINK(ads->childw,qu);
 453     break;
 454   case query_done:
 455     LIST_UNLINK(ads->output,qu);
 456     break;
 457   default:
 458     abort();
 459   }
 460   free_query_allocs(qu);
 461   free(qu->answer);
 462   free(qu);
 463   adns__consistency(ads,0,cc_entex);
 464 }
 465
 466 void adns__update_expires(adns_query qu, unsigned long ttl,
 467                           struct timeval now) {
 468   time_t max;
 469
 470   assert(ttl <= MAXTTLBELIEVE);
 471   max= now.tv_sec + ttl;
 472   if (qu->expires < max) return;
 473   qu->expires= max;
 474 }
 475
 476 static void makefinal_query(adns_query qu) {
 477   adns_answer *ans;
 478   int rrn;
 479
 480   ans= qu->answer;
 481
 482   if (qu->interim_allocd) {
 483     ans= realloc(qu->answer,
 484                  MEM_ROUND(MEM_ROUND(sizeof(*ans)) + qu->interim_allocd));
 485     if (!ans) goto x_nomem;
 486     qu->answer= ans;
 487   }
 488
 489   qu->final_allocspace= (byte*)ans + MEM_ROUND(sizeof(*ans));
 490   adns__makefinal_str(qu,&ans->cname);
 491   adns__makefinal_str(qu,&ans->owner);
 492
 493   if (ans->nrrs) {
 494     adns__makefinal_block(qu, &ans->rrs.untyped, ans->nrrs*ans->rrsz);
 495
 496     for (rrn=0; rrn<ans->nrrs; rrn++)
 497       qu->typei->makefinal(qu, ans->rrs.bytes + rrn*ans->rrsz);
 498   }
 499
 500   free_query_allocs(qu);
 501   return;
 502
 503  x_nomem:
 504   qu->preserved_allocd= 0;
 505   qu->answer->cname= 0;
 506   qu->answer->owner= 0;
 507   adns__reset_preserved(qu); /* (but we just threw away the preserved stuff) */
 508
 509   qu->answer->status= adns_s_nomemory;
 510   free_query_allocs(qu);
 511 }
 512
 513 void adns__query_done(adns_query qu) {
 514   adns_answer *ans;
 515   adns_query parent;
 516
 517   cancel_children(qu);
 518
 519   qu->id= -1;
 520   ans= qu->answer;
 521
 522   if (qu->flags & adns_qf_search && ans->status != adns_s_nomemory) {
 523     if (!save_owner(qu, qu->search_vb.buf, qu->search_vb.used)) {
 524       adns__query_fail(qu,adns_s_nomemory);
 525       return;
 526     }
 527   }
 528
 529   if (ans->nrrs && qu->typei->diff_needswap) {
 530     if (!adns__vbuf_ensure(&qu->vb,qu->typei->rrsz)) {
 531       adns__query_fail(qu,adns_s_nomemory);
 532       return;
 533     }
 534     adns__isort(ans->rrs.bytes, ans->nrrs, ans->rrsz,
 535                 qu->vb.buf,
 536                 (int(*)(void*, const void*, const void*))
 537                   qu->typei->diff_needswap,
 538                 qu->ads);
 539   }
 540   if (ans->nrrs && qu->typei->postsort) {
 541     qu->typei->postsort(qu->ads, ans->rrs.bytes, ans->nrrs, qu->typei);
 542   }
 543
 544   ans->expires= qu->expires;
 545   parent= qu->parent;
 546   if (parent) {
 547     LIST_UNLINK_PART(parent->children,qu,siblings.);
 548     LIST_UNLINK(qu->ads->childw,parent);
 549     qu->ctx.callback(parent,qu);
 550     free_query_allocs(qu);
 551     free(qu->answer);
 552     free(qu);
 553   } else {
 554     makefinal_query(qu);
 555     LIST_LINK_TAIL(qu->ads->output,qu);
 556     qu->state= query_done;
 557   }
 558 }
 559
 560 void adns__query_fail(adns_query qu, adns_status stat) {
 561   adns__reset_preserved(qu);
 562   qu->answer->status= stat;
 563   adns__query_done(qu);
 564 }
 565
 566 void adns__makefinal_str(adns_query qu, char **strp) {
 567   int l;
 568   char *before, *after;
 569
 570   before= *strp;
 571   if (!before) return;
 572   l= strlen(before)+1;
 573   after= adns__alloc_final(qu,l);
 574   memcpy(after,before,l);
 575   *strp= after;
 576 }
 577
 578 void adns__makefinal_block(adns_query qu, void **blpp, size_t sz) {
 579   void *before, *after;
 580
 581   before= *blpp;
 582   if (!before) return;
 583   after= adns__alloc_final(qu,sz);
 584   memcpy(after,before,sz);
 585   *blpp= after;
 586 }