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