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     ol--;
 229   }
 230
 231   if (flags & adns_qf_search) {
 232     r= adns__vbuf_append(&qu->search_vb,owner,ol);
 233     if (!r) { stat= adns_s_nomemory; goto x_adnsfail; }
 234
 235     for (ndots=0, p=owner; (p= strchr(p,'.')); p++, ndots++);
 236     qu->search_doneabs= (ndots >= ads->searchndots) ? -1 : 0;
 237     qu->search_origlen= ol;
 238     adns__search_next(ads,qu,now);
 239   } else {
 240     if (flags & adns_qf_owner) {
 241       if (!save_owner(qu,owner,ol)) { stat= adns_s_nomemory; goto x_adnsfail; }
 242     }
 243     query_simple(ads,qu, owner,ol, typei,flags, now);
 244   }
 245   adns__autosys(ads,now);
 246   adns__consistency(ads,qu,cc_entex);
 247   return 0;
 248
 249  x_adnsfail:
 250   adns__query_fail(qu,stat);
 251   adns__consistency(ads,qu,cc_entex);
 252   return 0;
 253
 254  x_errno:
 255   r= errno;
 256   assert(r);
 257   adns__consistency(ads,0,cc_entex);
 258   return r;
 259 }
 260
 261 int adns_submit_reverse(adns_state ads,
 262                         const struct sockaddr *addr,
 263                         adns_rrtype type,
 264                         int flags,
 265                         void *context,
 266                         adns_query *query_r) {
 267   const unsigned char *iaddr;
 268   char buf[30];
 269
 270   if (type != adns_r_ptr && type != adns_r_ptr_raw) return EINVAL;
 271   flags &= ~adns_qf_search;
 272
 273   if (addr->sa_family != AF_INET) return ENOSYS;
 274   iaddr= (const unsigned char*) &(((const struct sockaddr_in*)addr) -> sin_addr);
 275
 276   sprintf(buf, "%d.%d.%d.%d.in-addr.arpa",
 277           iaddr[3], iaddr[2], iaddr[1], iaddr[0]);
 278
 279   return adns_submit(ads,buf,type,flags,context,query_r);
 280 }
 281
 282 int adns_synchronous(adns_state ads,
 283                      const char *owner,
 284                      adns_rrtype type,
 285                      int flags,
 286                      adns_answer **answer_r) {
 287   adns_query qu;
 288   int r;
 289
 290   r= adns_submit(ads,owner,type,flags,0,&qu);
 291   if (r) return r;
 292
 293   r= adns_wait(ads,&qu,answer_r,0);
 294   if (r) adns_cancel(qu);
 295
 296   return r;
 297 }
 298
 299 static void *alloc_common(adns_query qu, size_t sz) {
 300   allocnode *an;
 301
 302   if (!sz) return qu; /* Any old pointer will do */
 303   assert(!qu->final_allocspace);
 304   an= malloc(MEM_ROUND(MEM_ROUND(sizeof(*an)) + sz));
 305   if (!an) return 0;
 306   LIST_LINK_TAIL(qu->allocations,an);
 307   return (byte*)an + MEM_ROUND(sizeof(*an));
 308 }
 309
 310 void *adns__alloc_interim(adns_query qu, size_t sz) {
 311   void *rv;
 312
 313   sz= MEM_ROUND(sz);
 314   rv= alloc_common(qu,sz);
 315   if (!rv) return 0;
 316   qu->interim_allocd += sz;
 317   return rv;
 318 }
 319
 320 void *adns__alloc_preserved(adns_query qu, size_t sz) {
 321   void *rv;
 322
 323   sz= MEM_ROUND(sz);
 324   rv= adns__alloc_interim(qu,sz);
 325   if (!rv) return 0;
 326   qu->preserved_allocd += sz;
 327   return rv;
 328 }
 329
 330 void *adns__alloc_mine(adns_query qu, size_t sz) {
 331   return alloc_common(qu,MEM_ROUND(sz));
 332 }
 333
 334 void adns__transfer_interim(adns_query from, adns_query to, void *block, size_t sz) {
 335   allocnode *an;
 336
 337   if (!block) return;
 338   an= (void*)((byte*)block - MEM_ROUND(sizeof(*an)));
 339
 340   assert(!to->final_allocspace);
 341   assert(!from->final_allocspace);
 342
 343   LIST_UNLINK(from->allocations,an);
 344   LIST_LINK_TAIL(to->allocations,an);
 345
 346   from->interim_allocd -= sz;
 347   to->interim_allocd += sz;
 348
 349   if (to->expires > from->expires) to->expires= from->expires;
 350 }
 351
 352 void *adns__alloc_final(adns_query qu, size_t sz) {
 353   /* When we're in the _final stage, we _subtract_ from interim_alloc'd
 354    * each allocation, and use final_allocspace to point to the next free
 355    * bit.
 356    */
 357   void *rp;
 358
 359   sz= MEM_ROUND(sz);
 360   rp= qu->final_allocspace;
 361   assert(rp);
 362   qu->interim_allocd -= sz;
 363   assert(qu->interim_allocd>=0);
 364   qu->final_allocspace= (byte*)rp + sz;
 365   return rp;
 366 }
 367
 368 static void cancel_children(adns_query qu) {
 369   adns_query cqu, ncqu;
 370
 371   for (cqu= qu->children.head; cqu; cqu= ncqu) {
 372     ncqu= cqu->siblings.next;
 373     adns_cancel(cqu);
 374   }
 375 }
 376
 377 void adns__reset_preserved(adns_query qu) {
 378   assert(!qu->final_allocspace);
 379   cancel_children(qu);
 380   qu->answer->nrrs= 0;
 381   qu->answer->rrs.untyped= 0;
 382   qu->interim_allocd= qu->preserved_allocd;
 383 }
 384
 385 static void free_query_allocs(adns_query qu) {
 386   allocnode *an, *ann;
 387
 388   cancel_children(qu);
 389   for (an= qu->allocations.head; an; an= ann) { ann= an->next; free(an); }
 390   LIST_INIT(qu->allocations);
 391   adns__vbuf_free(&qu->vb);
 392 }
 393
 394 void adns_cancel(adns_query qu) {
 395   adns_state ads;
 396
 397   ads= qu->ads;
 398   adns__consistency(ads,qu,cc_entex);
 399   if (qu->parent) LIST_UNLINK_PART(qu->parent->children,qu,siblings.);
 400   switch (qu->state) {
 401   case query_tosend: case query_tcpwait: case query_tcpsent:
 402     LIST_UNLINK(ads->timew,qu);
 403     break;
 404   case query_child:
 405     LIST_UNLINK(ads->childw,qu);
 406     break;
 407   case query_done:
 408     LIST_UNLINK(ads->output,qu);
 409     break;
 410   default:
 411     abort();
 412   }
 413   free_query_allocs(qu);
 414   free(qu->answer);
 415   free(qu);
 416   adns__consistency(ads,0,cc_entex);
 417 }
 418
 419 void adns__update_expires(adns_query qu, unsigned long ttl, struct timeval now) {
 420   time_t max;
 421
 422   assert(ttl <= MAXTTLBELIEVE);
 423   max= now.tv_sec + ttl;
 424   if (qu->expires < max) return;
 425   qu->expires= max;
 426 }
 427
 428 static void makefinal_query(adns_query qu) {
 429   adns_answer *ans;
 430   int rrn;
 431
 432   ans= qu->answer;
 433
 434   if (qu->interim_allocd) {
 435     ans= realloc(qu->answer, MEM_ROUND(MEM_ROUND(sizeof(*ans)) + qu->interim_allocd));
 436     if (!ans) goto x_nomem;
 437     qu->answer= ans;
 438   }
 439
 440   qu->final_allocspace= (byte*)ans + MEM_ROUND(sizeof(*ans));
 441   adns__makefinal_str(qu,&ans->cname);
 442   adns__makefinal_str(qu,&ans->owner);
 443
 444   if (ans->nrrs) {
 445     adns__makefinal_block(qu, &ans->rrs.untyped, ans->nrrs*ans->rrsz);
 446
 447     for (rrn=0; rrn<ans->nrrs; rrn++)
 448       qu->typei->makefinal(qu, ans->rrs.bytes + rrn*ans->rrsz);
 449   }
 450
 451   free_query_allocs(qu);
 452   return;
 453
 454  x_nomem:
 455   qu->preserved_allocd= 0;
 456   qu->answer->cname= 0;
 457   qu->answer->owner= 0;
 458   adns__reset_preserved(qu); /* (but we just threw away the preserved stuff) */
 459
 460   qu->answer->status= adns_s_nomemory;
 461   free_query_allocs(qu);
 462 }
 463
 464 void adns__query_done(adns_query qu) {
 465   adns_answer *ans;
 466   adns_query parent;
 467
 468   cancel_children(qu);
 469
 470   qu->id= -1;
 471   ans= qu->answer;
 472
 473   if (qu->flags & adns_qf_owner && qu->flags & adns_qf_search &&
 474       ans->status != adns_s_nomemory) {
 475     if (!save_owner(qu, qu->search_vb.buf, qu->search_vb.used)) {
 476       adns__query_fail(qu,adns_s_nomemory);
 477       return;
 478     }
 479   }
 480
 481   if (ans->nrrs && qu->typei->diff_needswap) {
 482     if (!adns__vbuf_ensure(&qu->vb,qu->typei->rrsz)) {
 483       adns__query_fail(qu,adns_s_nomemory);
 484       return;
 485     }
 486     adns__isort(ans->rrs.bytes, ans->nrrs, ans->rrsz,
 487                 qu->vb.buf,
 488                 (int(*)(void*, const void*, const void*))qu->typei->diff_needswap,
 489                 qu->ads);
 490   }
 491
 492   ans->expires= qu->expires;
 493   parent= qu->parent;
 494   if (parent) {
 495     LIST_UNLINK_PART(parent->children,qu,siblings.);
 496     LIST_UNLINK(qu->ads->childw,parent);
 497     qu->ctx.callback(parent,qu);
 498     free_query_allocs(qu);
 499     free(qu);
 500   } else {
 501     makefinal_query(qu);
 502     LIST_LINK_TAIL(qu->ads->output,qu);
 503     qu->state= query_done;
 504   }
 505 }
 506
 507 void adns__query_fail(adns_query qu, adns_status stat) {
 508   adns__reset_preserved(qu);
 509   qu->answer->status= stat;
 510   adns__query_done(qu);
 511 }
 512
 513 void adns__makefinal_str(adns_query qu, char **strp) {
 514   int l;
 515   char *before, *after;
 516
 517   before= *strp;
 518   if (!before) return;
 519   l= strlen(before)+1;
 520   after= adns__alloc_final(qu,l);
 521   memcpy(after,before,l);
 522   *strp= after;
 523 }
 524
 525 void adns__makefinal_block(adns_query qu, void **blpp, size_t sz) {
 526   void *before, *after;
 527
 528   before= *blpp;
 529   if (!before) return;
 530   after= adns__alloc_final(qu,sz);
 531   memcpy(after,before,sz);
 532   *blpp= after;
 533 }