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 Copyright (C) 1997-1999 Ian Jackson
   9  *
  10  *  This program is free software; you can redistribute it and/or modify
  11  *  it under the terms of the GNU General Public License as published by
  12  *  the Free Software Foundation; either version 2, or (at your option)
  13  *  any later version.
  14  *
  15  *  This program is distributed in the hope that it will be useful,
  16  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  *  GNU General Public License for more details.
  19  *
  20  *  You should have received a copy of the GNU General Public License
  21  *  along with this program; if not, write to the Free Software Foundation,
  22  *  Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  23  */
  24
  25 #include "internal.h"
  26
  27 #include <stdlib.h>
  28 #include <unistd.h>
  29 #include <errno.h>
  30 #include <string.h>
  31
  32 #include <sys/time.h>
  33
  34 #include "internal.h"
  35
  36 int adns__internal_submit(adns_state ads, adns_query *query_r,
  37                           const typeinfo *typei, vbuf *qumsg_vb, int id,
  38                           adns_queryflags flags, struct timeval now,
  39                           adns_status failstat, const qcontext *ctx) {
  40   adns_query qu;
  41
  42   qu= malloc(sizeof(*qu)); if (!qu) goto x_nomemory;
  43   qu->answer= malloc(sizeof(*qu->answer)); if (!qu->answer) goto x_freequ_nomemory;
  44
  45   qu->ads= ads;
  46   qu->state= query_udp;
  47   qu->back= qu->next= qu->parent= 0;
  48   LIST_INIT(qu->children);
  49   qu->siblings.next= qu->siblings.back= 0;
  50   LIST_INIT(qu->allocations);
  51   qu->interim_allocd= 0;
  52   qu->final_allocspace= 0;
  53
  54   qu->typei= typei;
  55   adns__vbuf_init(&qu->vb);
  56
  57   qu->cname_dgram= 0;
  58   qu->cname_dglen= qu->cname_begin= 0;
  59
  60   qu->id= id;
  61   qu->flags= flags;
  62   qu->udpretries= 0;
  63   qu->udpnextserver= 0;
  64   qu->udpsent= qu->tcpfailed= 0;
  65   timerclear(&qu->timeout);
  66   memcpy(&qu->ctx,ctx,sizeof(qu->ctx));
  67
  68   qu->answer->status= adns_s_ok;
  69   qu->answer->cname= 0;
  70   qu->answer->type= typei->type;
  71   qu->answer->nrrs= 0;
  72   qu->answer->rrs= 0;
  73   qu->answer->rrsz= typei->rrsz;
  74
  75   *query_r= qu;
  76
  77   qu->query_dglen= qumsg_vb->used;
  78   if (qumsg_vb->used) {
  79     qu->query_dgram= malloc(qumsg_vb->used);
  80     if (!qu->query_dgram) {
  81       adns__query_fail(qu,adns_s_nomemory);
  82       return adns_s_ok;
  83     }
  84     memcpy(qu->query_dgram,qumsg_vb->buf,qumsg_vb->used);
  85   } else {
  86     qu->query_dgram= 0;
  87   }
  88   qu->vb= *qumsg_vb;
  89   adns__vbuf_init(qumsg_vb);
  90
  91   if (failstat) goto x_failure;
  92
  93   if (qu->typei->begin) {
  94     failstat= qu->typei->begin(ads,qu,now);
  95     if (failstat) goto x_failure;
  96   } else {
  97     adns__query_udp(qu,now);
  98   }
  99
 100   adns__autosys(ads,now);
 101
 102   return adns_s_ok;
 103
 104  x_freequ_nomemory:
 105   free(qu);
 106  x_nomemory:
 107   adns__vbuf_free(qumsg_vb);
 108   return adns_s_nomemory;
 109
 110  x_failure:
 111   adns__query_fail(qu,failstat);
 112   return adns_s_ok;
 113 }
 114
 115 adns_status adns__subquery(adns_state ads, adns_query parent, vbuf *vb,
 116                            const byte *qd_dgram, int qd_dglen, int qd_begin,
 117                            adns_rrtype type, adns_queryflags flags,
 118                            struct timeval now, const qcontext *ctx) {
 119   adns_status st;
 120   int id;
 121   adns_query nqu;
 122
 123   st= adns__mkquery_frdgram(ads, vb, &id,
 124                             qd_dgram, qd_dglen, qd_begin,
 125                             type, flags);
 126   if (st) return st;
 127
 128   st= adns__internal_submit(ads, &nqu, adns__findtype(type),
 129                             vb, id, flags, now, 0, ctx);
 130   if (st) return st;
 131
 132   nqu->parent= parent;
 133   LIST_LINK_TAIL_PART(parent->children,nqu,siblings.);
 134
 135   return adns_s_ok;
 136 }
 137
 138 int adns_submit(adns_state ads,
 139                 const char *owner,
 140                 adns_rrtype type,
 141                 adns_queryflags flags,
 142                 void *context,
 143                 adns_query *query_r) {
 144   qcontext ctx;
 145   int id, r, ol;
 146   vbuf vb;
 147   adns_status stat;
 148   const typeinfo *typei;
 149   struct timeval now;
 150
 151   typei= adns__findtype(type);
 152   if (!typei) return adns_s_unknownrrtype;
 153
 154   ctx.ext= context;
 155   ctx.callback= 0;
 156   memset(&ctx.info,0,sizeof(ctx.info));
 157
 158   r= gettimeofday(&now,0); if (r) return errno;
 159   id= 0;
 160
 161   if (!(flags & adns__iqaf_override)) {
 162     flags &= ~adns__iqaf_mask;
 163     flags |= ads->iflags & adns__iqaf_mask;
 164   }
 165
 166   adns__vbuf_init(&vb);
 167
 168   ol= strlen(owner);
 169   if (ol<=1 || ol>DNS_MAXDOMAIN+1) { stat= adns_s_querydomaintoolong; goto xit; }
 170
 171   if (owner[ol-1]=='.' && owner[ol-2]!='\\') { flags &= ~adns_qf_search; ol--; }
 172
 173
 174                      typei->initialtype ? typei->initialtype(ads,flags) : typei->type
 175                        stat= adns__mkquery(ads,&vb,&id, owner,ol, typei,flags);
 176
 177  xit:
 178   return adns__internal_submit(ads,query_r, typei,&vb,id, flags,now, stat,&ctx);
 179 }
 180
 181 int adns_synchronous(adns_state ads,
 182                      const char *owner,
 183                      adns_rrtype type,
 184                      adns_queryflags flags,
 185                      adns_answer **answer_r) {
 186   adns_query qu;
 187   int r;
 188
 189   r= adns_submit(ads,owner,type,flags,0,&qu);
 190   if (r) return r;
 191
 192   r= adns_wait(ads,&qu,answer_r,0);
 193   if (r) adns_cancel(qu);
 194
 195   return r;
 196 }
 197
 198 static void *alloc_common(adns_query qu, size_t sz) {
 199   allocnode *an;
 200
 201   if (!sz) return qu; /* Any old pointer will do */
 202   assert(!qu->final_allocspace);
 203   an= malloc(MEM_ROUND(MEM_ROUND(sizeof(*an)) + sz));
 204   if (!an) return 0;
 205   LIST_LINK_TAIL(qu->allocations,an);
 206   return (byte*)an + MEM_ROUND(sizeof(*an));
 207 }
 208
 209 void *adns__alloc_interim(adns_query qu, size_t sz) {
 210   sz= MEM_ROUND(sz);
 211   qu->interim_allocd += sz;
 212   return alloc_common(qu,sz);
 213 }
 214
 215 void *adns__alloc_mine(adns_query qu, size_t sz) {
 216   return alloc_common(qu,MEM_ROUND(sz));
 217 }
 218
 219 void adns__transfer_interim(adns_query from, adns_query to, void *block, size_t sz) {
 220   allocnode *an;
 221
 222   if (!block) return;
 223   an= (void*)((byte*)block - MEM_ROUND(sizeof(*an)));
 224
 225   assert(!to->final_allocspace);
 226   assert(!from->final_allocspace);
 227
 228   LIST_UNLINK(from->allocations,an);
 229   LIST_LINK_TAIL(to->allocations,an);
 230
 231   from->interim_allocd -= sz;
 232   to->interim_allocd += sz;
 233 }
 234
 235 void *adns__alloc_final(adns_query qu, size_t sz) {
 236   /* When we're in the _final stage, we _subtract_ from interim_alloc'd
 237    * each allocation, and use final_allocspace to point to the next free
 238    * bit.
 239    */
 240   void *rp;
 241
 242   sz= MEM_ROUND(sz);
 243   rp= qu->final_allocspace;
 244   assert(rp);
 245   qu->interim_allocd -= sz;
 246   assert(qu->interim_allocd>=0);
 247   qu->final_allocspace= (byte*)rp + sz;
 248   return rp;
 249 }
 250
 251 static void cancel_children(adns_query qu) {
 252   adns_query cqu, ncqu;
 253
 254   for (cqu= qu->children.head; cqu; cqu= ncqu) {
 255     ncqu= cqu->siblings.next;
 256     adns_cancel(cqu);
 257   }
 258   LIST_INIT(qu->children);
 259 }
 260
 261 void adns__reset_cnameonly(adns_query qu) {
 262   assert(!qu->final_allocspace);
 263   cancel_children(qu);
 264   qu->answer->nrrs= 0;
 265   qu->answer->rrs= 0;
 266   qu->interim_allocd= qu->answer->cname ? MEM_ROUND(strlen(qu->answer->cname)+1) : 0;
 267 }
 268
 269 static void free_query_allocs(adns_query qu) {
 270   allocnode *an, *ann;
 271
 272   cancel_children(qu);
 273   for (an= qu->allocations.head; an; an= ann) { ann= an->next; free(an); }
 274   adns__vbuf_free(&qu->vb);
 275 }
 276
 277 void adns_cancel(adns_query qu) {
 278   switch (qu->state) {
 279   case query_udp: case query_tcpwait: case query_tcpsent:
 280     LIST_UNLINK(qu->ads->timew,qu);
 281     break;
 282   case query_child:
 283     LIST_UNLINK(qu->ads->childw,qu);
 284     break;
 285   case query_done:
 286     LIST_UNLINK(qu->ads->output,qu);
 287     break;
 288   default:
 289     abort();
 290   }
 291   free_query_allocs(qu);
 292   free(qu->answer);
 293   free(qu);
 294 }
 295
 296 static void makefinal_query(adns_query qu) {
 297   adns_answer *ans;
 298   int rrn;
 299
 300   ans= qu->answer;
 301
 302   if (qu->interim_allocd) {
 303     ans= realloc(qu->answer, MEM_ROUND(MEM_ROUND(sizeof(*ans)) + qu->interim_allocd));
 304     if (!ans) goto x_nomem;
 305     qu->answer= ans;
 306   }
 307
 308   qu->final_allocspace= (byte*)ans + MEM_ROUND(sizeof(*ans));
 309   adns__makefinal_str(qu,&ans->cname);
 310
 311   if (ans->nrrs) {
 312     adns__makefinal_block(qu, &ans->rrs.untyped, ans->nrrs*ans->rrsz);
 313
 314     for (rrn=0; rrn<ans->nrrs; rrn++)
 315       qu->typei->makefinal(qu, ans->rrs.bytes + rrn*ans->rrsz);
 316   }
 317
 318   free_query_allocs(qu);
 319   return;
 320
 321  x_nomem:
 322   qu->answer->status= adns_s_nomemory;
 323   qu->answer->cname= 0;
 324   adns__reset_cnameonly(qu);
 325   free_query_allocs(qu);
 326 }
 327
 328 void adns__query_done(adns_query qu) {
 329   adns_answer *ans;
 330   adns_query parent;
 331
 332   qu->id= -1;
 333   ans= qu->answer;
 334
 335   if (ans->nrrs && qu->typei->diff_needswap) {
 336     if (!adns__vbuf_ensure(&qu->vb,qu->typei->rrsz)) {
 337       adns__query_fail(qu,adns_s_nomemory);
 338       return;
 339     }
 340     adns__isort(ans->rrs.bytes, ans->nrrs, ans->rrsz,
 341                 qu->vb.buf,
 342                 (int(*)(void*, const void*, const void*))qu->typei->diff_needswap,
 343                 qu->ads);
 344   }
 345
 346   parent= qu->parent;
 347   if (parent) {
 348     LIST_UNLINK_PART(parent->children,qu,siblings.);
 349     qu->ctx.callback(parent,qu);
 350     free_query_allocs(qu);
 351     free(qu);
 352   } else {
 353     makefinal_query(qu);
 354     LIST_LINK_TAIL(qu->ads->output,qu);
 355   }
 356 }
 357
 358 void adns__query_fail(adns_query qu, adns_status stat) {
 359   adns__reset_cnameonly(qu);
 360   qu->answer->status= stat;
 361   adns__query_done(qu);
 362 }
 363
 364 void adns__makefinal_str(adns_query qu, char **strp) {
 365   int l;
 366   char *before, *after;
 367
 368   before= *strp;
 369   if (!before) return;
 370   l= strlen(before)+1;
 371   after= adns__alloc_final(qu,l);
 372   memcpy(after,before,l);
 373   *strp= after;
 374 }
 375
 376 void adns__makefinal_block(adns_query qu, void **blpp, size_t sz) {
 377   void *before, *after;
 378
 379   before= *blpp;
 380   if (!before) return;
 381   after= adns__alloc_final(qu,sz);
 382   memcpy(after,before,sz);
 383   *blpp= after;
 384 }