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->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__ckl_hostname(adns_state ads, adns_queryflags flags,
 112                                union checklabel_state *cls,
 113                                qcontext *ctx, int labnum,
 114                                const char *label, int lablen)
 115 {
 116   int i, c;
 117
 118   if (flags & adns_qf_quoteok_query) return adns_s_ok;
 119   for (i=0; i<lablen; i++) {
 120     c= label[i];
 121     if (c == '-') {
 122       if (!i) return adns_s_querydomaininvalid;
 123     } else if (!ctype_alpha(c) && !ctype_digit(c)) {
 124       return adns_s_querydomaininvalid;
 125     }
 126   }
 127   return adns_s_ok;
 128 }
 129
 130 static adns_status check_domain_name(adns_state ads, adns_queryflags flags,
 131                                      qcontext *ctx, const typeinfo *typei,
 132                                      const byte *dgram, int dglen)
 133 {
 134   findlabel_state fls;
 135   adns_status err;
 136   int labnum= 0, labstart, lablen;
 137   union checklabel_state cls;
 138
 139   adns__findlabel_start(&fls,ads, -1,0, dgram,dglen,dglen, DNS_HDRSIZE,0);
 140   do {
 141     err= adns__findlabel_next(&fls, &lablen,&labstart);
 142     assert(!err); assert(lablen >= 0);
 143     err= typei->checklabel(ads,flags, &cls,ctx,
 144                            labnum++, dgram+labstart,lablen);
 145     if (err) return err;
 146   } while (lablen);
 147   return adns_s_ok;
 148 }
 149
 150 adns_status adns__internal_submit(adns_state ads, adns_query *query_r,
 151                                   const typeinfo *typei, vbuf *qumsg_vb,
 152                                   int id,
 153                                   adns_queryflags flags, struct timeval now,
 154                                   qcontext *ctx) {
 155   adns_query qu;
 156   adns_status err;
 157
 158   err= check_domain_name(ads, flags,ctx,typei, qumsg_vb->buf,qumsg_vb->used);
 159   if (err) goto x_err;
 160   qu= query_alloc(ads,typei,typei->typekey,flags,now);
 161   if (!qu) { err = adns_s_nomemory; goto x_err; }
 162   *query_r= qu;
 163
 164   memcpy(&qu->ctx,ctx,sizeof(qu->ctx));
 165   query_submit(ads,qu, typei,qumsg_vb,id,flags,now);
 166
 167   return adns_s_ok;
 168
 169 x_err:
 170   adns__vbuf_free(qumsg_vb);
 171   return err;
 172 }
 173
 174 static void query_simple(adns_state ads, adns_query qu,
 175                          const char *owner, int ol,
 176                          const typeinfo *typei, adns_queryflags flags,
 177                          struct timeval now) {
 178   vbuf vb_new;
 179   int id;
 180   adns_status stat;
 181
 182   stat= adns__mkquery(ads,&qu->vb,&id, owner,ol,
 183                       typei,qu->answer->type, flags);
 184   if (stat) {
 185     if (stat == adns_s_querydomaintoolong && (flags & adns_qf_search)) {
 186       adns__search_next(ads,qu,now);
 187       return;
 188     } else {
 189       adns__query_fail(qu,stat);
 190       return;
 191     }
 192   }
 193
 194   stat= check_domain_name(ads, flags,&qu->ctx,typei, qu->vb.buf,qu->vb.used);
 195   if (stat) { adns__query_fail(qu,stat); return; }
 196
 197   vb_new= qu->vb;
 198   adns__vbuf_init(&qu->vb);
 199   query_submit(ads,qu, typei,&vb_new,id, flags,now);
 200 }
 201
 202 void adns__search_next(adns_state ads, adns_query qu, struct timeval now) {
 203   const char *nextentry;
 204   adns_status stat;
 205
 206   if (qu->search_doneabs<0) {
 207     nextentry= 0;
 208     qu->search_doneabs= 1;
 209   } else {
 210     if (qu->search_pos >= ads->nsearchlist) {
 211       if (qu->search_doneabs) {
 212         qu->search_vb.used= qu->search_origlen;
 213         stat= adns_s_nxdomain; goto x_fail;
 214       } else {
 215         nextentry= 0;
 216         qu->search_doneabs= 1;
 217       }
 218     } else {
 219       nextentry= ads->searchlist[qu->search_pos++];
 220     }
 221   }
 222
 223   qu->search_vb.used= qu->search_origlen;
 224   if (nextentry) {
 225     if (!adns__vbuf_append(&qu->search_vb,".",1) ||
 226         !adns__vbuf_appendstr(&qu->search_vb,nextentry))
 227       goto x_nomemory;
 228   }
 229
 230   free(qu->query_dgram);
 231   qu->query_dgram= 0; qu->query_dglen= 0;
 232
 233   query_simple(ads,qu, qu->search_vb.buf, qu->search_vb.used,
 234                qu->typei, qu->flags, now);
 235   return;
 236
 237 x_nomemory:
 238   stat= adns_s_nomemory;
 239 x_fail:
 240   adns__query_fail(qu,stat);
 241 }
 242
 243 static int save_owner(adns_query qu, const char *owner, int ol) {
 244   /* Returns 1 if OK, otherwise there was no memory. */
 245   adns_answer *ans;
 246
 247   if (!(qu->flags & adns_qf_owner)) return 1;
 248
 249   ans= qu->answer;
 250   assert(!ans->owner);
 251
 252   ans->owner= adns__alloc_preserved(qu,ol+1);  if (!ans->owner) return 0;
 253
 254   memcpy(ans->owner,owner,ol);
 255   ans->owner[ol]= 0;
 256   return 1;
 257 }
 258
 259 int adns_submit(adns_state ads,
 260                 const char *owner,
 261                 adns_rrtype type,
 262                 adns_queryflags flags,
 263                 void *context,
 264                 adns_query *query_r) {
 265   int r, ol, ndots;
 266   adns_status stat;
 267   const typeinfo *typei;
 268   struct timeval now;
 269   adns_query qu;
 270   const char *p;
 271
 272   adns__consistency(ads,0,cc_entex);
 273
 274   typei= adns__findtype(type);
 275   if (!typei) return ENOSYS;
 276
 277   r= gettimeofday(&now,0); if (r) goto x_errno;
 278   qu= query_alloc(ads,typei,type,flags,now); if (!qu) goto x_errno;
 279
 280   qu->ctx.ext= context;
 281   qu->ctx.callback= 0;
 282   memset(&qu->ctx.pinfo,0,sizeof(qu->ctx.pinfo));
 283   memset(&qu->ctx.tinfo,0,sizeof(qu->ctx.tinfo));
 284
 285   *query_r= qu;
 286
 287   ol= strlen(owner);
 288   if (!ol) { stat= adns_s_querydomaininvalid; goto x_adnsfail; }
 289   if (ol>DNS_MAXDOMAIN+1) { stat= adns_s_querydomaintoolong; goto x_adnsfail; }
 290
 291   if (ol>=1 && owner[ol-1]=='.' && (ol<2 || owner[ol-2]!='\\')) {
 292     flags &= ~adns_qf_search;
 293     qu->flags= flags;
 294     ol--;
 295   }
 296
 297   if (flags & adns_qf_search) {
 298     r= adns__vbuf_append(&qu->search_vb,owner,ol);
 299     if (!r) { stat= adns_s_nomemory; goto x_adnsfail; }
 300
 301     for (ndots=0, p=owner; (p= strchr(p,'.')); p++, ndots++);
 302     qu->search_doneabs= (ndots >= ads->searchndots) ? -1 : 0;
 303     qu->search_origlen= ol;
 304     adns__search_next(ads,qu,now);
 305   } else {
 306     if (flags & adns_qf_owner) {
 307       if (!save_owner(qu,owner,ol)) { stat= adns_s_nomemory; goto x_adnsfail; }
 308     }
 309     query_simple(ads,qu, owner,ol, typei,flags, now);
 310   }
 311   adns__autosys(ads,now);
 312   adns__consistency(ads,qu,cc_entex);
 313   return 0;
 314
 315  x_adnsfail:
 316   adns__query_fail(qu,stat);
 317   adns__consistency(ads,qu,cc_entex);
 318   return 0;
 319
 320  x_errno:
 321   r= errno;
 322   assert(r);
 323   adns__consistency(ads,0,cc_entex);
 324   return r;
 325 }
 326
 327 int adns_submit_reverse_any(adns_state ads,
 328                             const struct sockaddr *addr,
 329                             const char *zone,
 330                             adns_rrtype type,
 331                             adns_queryflags flags,
 332                             void *context,
 333                             adns_query *query_r) {
 334   const unsigned char *iaddr;
 335   char *buf, *buf_free;
 336   char shortbuf[100];
 337   int r, lreq;
 338
 339   flags &= ~adns_qf_search;
 340
 341   if (addr->sa_family != AF_INET) return ENOSYS;
 342   iaddr= (const unsigned char*)
 343     &(((const struct sockaddr_in*)addr) -> sin_addr);
 344
 345   lreq= strlen(zone) + 4*4 + 1;
 346   if (lreq > sizeof(shortbuf)) {
 347     buf= malloc(strlen(zone) + 4*4 + 1);
 348     if (!buf) return errno;
 349     buf_free= buf;
 350   } else {
 351     buf= shortbuf;
 352     buf_free= 0;
 353   }
 354   sprintf(buf, "%d.%d.%d.%d.%s", iaddr[3], iaddr[2], iaddr[1], iaddr[0], zone);
 355
 356   r= adns_submit(ads,buf,type,flags,context,query_r);
 357   free(buf_free);
 358   return r;
 359 }
 360
 361 int adns_submit_reverse(adns_state ads,
 362                         const struct sockaddr *addr,
 363                         adns_rrtype type,
 364                         adns_queryflags flags,
 365                         void *context,
 366                         adns_query *query_r) {
 367   if (type != adns_r_ptr && type != adns_r_ptr_raw) return EINVAL;
 368   return adns_submit_reverse_any(ads,addr,"in-addr.arpa",
 369                                  type,flags,context,query_r);
 370 }
 371
 372 int adns_synchronous(adns_state ads,
 373                      const char *owner,
 374                      adns_rrtype type,
 375                      adns_queryflags flags,
 376                      adns_answer **answer_r) {
 377   adns_query qu;
 378   int r;
 379
 380   r= adns_submit(ads,owner,type,flags,0,&qu);
 381   if (r) return r;
 382
 383   r= adns_wait(ads,&qu,answer_r,0);
 384   if (r) adns_cancel(qu);
 385
 386   return r;
 387 }
 388
 389 static void *alloc_common(adns_query qu, size_t sz) {
 390   allocnode *an;
 391
 392   if (!sz) return qu; /* Any old pointer will do */
 393   assert(!qu->final_allocspace);
 394   an= malloc(MEM_ROUND(MEM_ROUND(sizeof(*an)) + sz));
 395   if (!an) return 0;
 396   LIST_LINK_TAIL(qu->allocations,an);
 397   return (byte*)an + MEM_ROUND(sizeof(*an));
 398 }
 399
 400 void *adns__alloc_interim(adns_query qu, size_t sz) {
 401   void *rv;
 402
 403   sz= MEM_ROUND(sz);
 404   rv= alloc_common(qu,sz);
 405   if (!rv) return 0;
 406   qu->interim_allocd += sz;
 407   return rv;
 408 }
 409
 410 void *adns__alloc_preserved(adns_query qu, size_t sz) {
 411   void *rv;
 412
 413   sz= MEM_ROUND(sz);
 414   rv= adns__alloc_interim(qu,sz);
 415   if (!rv) return 0;
 416   qu->preserved_allocd += sz;
 417   return rv;
 418 }
 419
 420 void *adns__alloc_mine(adns_query qu, size_t sz) {
 421   return alloc_common(qu,MEM_ROUND(sz));
 422 }
 423
 424 void adns__transfer_interim(adns_query from, adns_query to,
 425                             void *block, size_t sz) {
 426   allocnode *an;
 427
 428   if (!block) return;
 429   an= (void*)((byte*)block - MEM_ROUND(sizeof(*an)));
 430
 431   assert(!to->final_allocspace);
 432   assert(!from->final_allocspace);
 433
 434   LIST_UNLINK(from->allocations,an);
 435   LIST_LINK_TAIL(to->allocations,an);
 436
 437   sz= MEM_ROUND(sz);
 438   from->interim_allocd -= sz;
 439   to->interim_allocd += sz;
 440
 441   if (to->expires > from->expires) to->expires= from->expires;
 442 }
 443
 444 void *adns__alloc_final(adns_query qu, size_t sz) {
 445   /* When we're in the _final stage, we _subtract_ from interim_alloc'd
 446    * each allocation, and use final_allocspace to point to the next free
 447    * bit.
 448    */
 449   void *rp;
 450
 451   sz= MEM_ROUND(sz);
 452   rp= qu->final_allocspace;
 453   assert(rp);
 454   qu->interim_allocd -= sz;
 455   assert(qu->interim_allocd>=0);
 456   qu->final_allocspace= (byte*)rp + sz;
 457   return rp;
 458 }
 459
 460 static void cancel_children(adns_query qu) {
 461   adns_query cqu, ncqu;
 462
 463   for (cqu= qu->children.head; cqu; cqu= ncqu) {
 464     ncqu= cqu->siblings.next;
 465     adns_cancel(cqu);
 466   }
 467 }
 468
 469 void adns__reset_preserved(adns_query qu) {
 470   assert(!qu->final_allocspace);
 471   cancel_children(qu);
 472   qu->answer->nrrs= 0;
 473   qu->answer->rrs.untyped= 0;
 474   qu->interim_allocd= qu->preserved_allocd;
 475 }
 476
 477 static void free_query_allocs(adns_query qu) {
 478   allocnode *an, *ann;
 479
 480   cancel_children(qu);
 481   for (an= qu->allocations.head; an; an= ann) { ann= an->next; free(an); }
 482   LIST_INIT(qu->allocations);
 483   adns__vbuf_free(&qu->vb);
 484   adns__vbuf_free(&qu->search_vb);
 485   free(qu->query_dgram);
 486   qu->query_dgram= 0;
 487 }
 488
 489 void adns_cancel(adns_query qu) {
 490   adns_state ads;
 491
 492   ads= qu->ads;
 493   adns__consistency(ads,qu,cc_entex);
 494   if (qu->parent) LIST_UNLINK_PART(qu->parent->children,qu,siblings.);
 495   switch (qu->state) {
 496   case query_tosend:
 497     LIST_UNLINK(ads->udpw,qu);
 498     break;
 499   case query_tcpw:
 500     LIST_UNLINK(ads->tcpw,qu);
 501     break;
 502   case query_childw:
 503     LIST_UNLINK(ads->childw,qu);
 504     break;
 505   case query_done:
 506     LIST_UNLINK(ads->output,qu);
 507     break;
 508   default:
 509     abort();
 510   }
 511   free_query_allocs(qu);
 512   free(qu->answer);
 513   free(qu);
 514   adns__consistency(ads,0,cc_entex);
 515 }
 516
 517 void adns__update_expires(adns_query qu, unsigned long ttl,
 518                           struct timeval now) {
 519   time_t max;
 520
 521   assert(ttl <= MAXTTLBELIEVE);
 522   max= now.tv_sec + ttl;
 523   if (qu->expires < max) return;
 524   qu->expires= max;
 525 }
 526
 527 static void makefinal_query(adns_query qu) {
 528   adns_answer *ans;
 529   int rrn;
 530
 531   ans= qu->answer;
 532
 533   if (qu->interim_allocd) {
 534     ans= realloc(qu->answer,
 535                  MEM_ROUND(MEM_ROUND(sizeof(*ans)) + qu->interim_allocd));
 536     if (!ans) goto x_nomem;
 537     qu->answer= ans;
 538   }
 539
 540   qu->final_allocspace= (byte*)ans + MEM_ROUND(sizeof(*ans));
 541   adns__makefinal_str(qu,&ans->cname);
 542   adns__makefinal_str(qu,&ans->owner);
 543
 544   if (ans->nrrs) {
 545     adns__makefinal_block(qu, &ans->rrs.untyped, ans->nrrs*ans->rrsz);
 546
 547     for (rrn=0; rrn<ans->nrrs; rrn++)
 548       qu->typei->makefinal(qu, ans->rrs.bytes + rrn*ans->rrsz);
 549   }
 550
 551   free_query_allocs(qu);
 552   return;
 553
 554  x_nomem:
 555   qu->preserved_allocd= 0;
 556   qu->answer->cname= 0;
 557   qu->answer->owner= 0;
 558   adns__reset_preserved(qu); /* (but we just threw away the preserved stuff) */
 559
 560   qu->answer->status= adns_s_nomemory;
 561   free_query_allocs(qu);
 562 }
 563
 564 void adns__query_done(adns_query qu) {
 565   adns_answer *ans;
 566   adns_query parent;
 567
 568   cancel_children(qu);
 569
 570   qu->id= -1;
 571   ans= qu->answer;
 572
 573   if (qu->flags & adns_qf_search && ans->status != adns_s_nomemory) {
 574     if (!save_owner(qu, qu->search_vb.buf, qu->search_vb.used)) {
 575       adns__query_fail(qu,adns_s_nomemory);
 576       return;
 577     }
 578   }
 579
 580   if (ans->nrrs && qu->typei->diff_needswap) {
 581     if (!adns__vbuf_ensure(&qu->vb,qu->typei->rrsz)) {
 582       adns__query_fail(qu,adns_s_nomemory);
 583       return;
 584     }
 585     adns__isort(ans->rrs.bytes, ans->nrrs, ans->rrsz,
 586                 qu->vb.buf,
 587                 (int(*)(void*, const void*, const void*))
 588                   qu->typei->diff_needswap,
 589                 qu->ads);
 590   }
 591   if (ans->nrrs && qu->typei->postsort) {
 592     qu->typei->postsort(qu->ads, ans->rrs.bytes, ans->nrrs, qu->typei);
 593   }
 594
 595   ans->expires= qu->expires;
 596   parent= qu->parent;
 597   if (parent) {
 598     LIST_UNLINK_PART(parent->children,qu,siblings.);
 599     LIST_UNLINK(qu->ads->childw,parent);
 600     qu->ctx.callback(parent,qu);
 601     free_query_allocs(qu);
 602     free(qu->answer);
 603     free(qu);
 604   } else {
 605     makefinal_query(qu);
 606     LIST_LINK_TAIL(qu->ads->output,qu);
 607     qu->state= query_done;
 608   }
 609 }
 610
 611 void adns__query_fail(adns_query qu, adns_status stat) {
 612   adns__reset_preserved(qu);
 613   qu->answer->status= stat;
 614   adns__query_done(qu);
 615 }
 616
 617 void adns__makefinal_str(adns_query qu, char **strp) {
 618   int l;
 619   char *before, *after;
 620
 621   before= *strp;
 622   if (!before) return;
 623   l= strlen(before)+1;
 624   after= adns__alloc_final(qu,l);
 625   memcpy(after,before,l);
 626   *strp= after;
 627 }
 628
 629 void adns__makefinal_block(adns_query qu, void **blpp, size_t sz) {
 630   void *before, *after;
 631
 632   before= *blpp;
 633   if (!before) return;
 634   after= adns__alloc_final(qu,sz);
 635   memcpy(after,before,sz);
 636   *blpp= after;
 637 }