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, 1998 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
  31 #include <sys/time.h>
  32
  33 #include "internal.h"
  34
  35 int adns__internal_submit(adns_state ads, adns_query *query_r,
  36                           const typeinfo *typei, vbuf *qumsg_vb, int id,
  37                           adns_queryflags flags, struct timeval now,
  38                           adns_status failstat, const qcontext *ctx) {
  39   adns_query qu;
  40
  41   qu= malloc(sizeof(*qu)); if (!qu) goto x_nomemory;
  42   qu->answer= malloc(sizeof(*qu->answer)); if (!qu->answer) goto x_freequ_nomemory;
  43
  44   qu->ads= ads;
  45   qu->state= query_udp;
  46   qu->back= qu->next= qu->parent= 0;
  47   LIST_INIT(qu->children);
  48   qu->siblings.next= qu->siblings.back= 0;
  49   LIST_INIT(qu->allocations);
  50   qu->interim_allocd= 0;
  51   qu->final_allocspace= 0;
  52
  53   qu->typei= typei;
  54   adns__vbuf_init(&qu->vb);
  55
  56   qu->cname_dgram= 0;
  57   qu->cname_dglen= qu->cname_begin= 0;
  58
  59   qu->id= id;
  60   qu->flags= flags;
  61   qu->udpretries= 0;
  62   qu->udpnextserver= 0;
  63   qu->udpsent= qu->tcpfailed= 0;
  64   timerclear(&qu->timeout);
  65   memcpy(&qu->context,ctx,sizeof(qu->context));
  66
  67   qu->answer->status= adns_s_ok;
  68   qu->answer->cname= 0;
  69   qu->answer->type= typei->type;
  70   qu->answer->nrrs= 0;
  71   qu->answer->rrs= 0;
  72   qu->answer->rrsz= typei->rrsz;
  73
  74   *query_r= qu;
  75
  76   qu->query_dglen= qumsg_vb->used;
  77   if (qumsg_vb->used) {
  78     qu->query_dgram= malloc(qumsg_vb->used);
  79     if (!qu->query_dgram) {
  80       adns__query_fail(qu,adns_s_nolocalmem);
  81       return adns_s_ok;
  82     }
  83     memcpy(qu->query_dgram,qumsg_vb->buf,qumsg_vb->used);
  84   } else {
  85     qu->query_dgram= 0;
  86   }
  87   qu->vb= *qumsg_vb;
  88   adns__vbuf_init(qumsg_vb);
  89
  90   if (failstat) {
  91     adns__query_fail(qu,failstat);
  92     return adns_s_ok;
  93   }
  94   adns__query_udp(qu,now);
  95   adns__autosys(ads,now);
  96
  97   return adns_s_ok;
  98
  99  x_freequ_nomemory:
 100   free(qu);
 101  x_nomemory:
 102   adns__vbuf_free(qumsg_vb);
 103   return adns_s_nolocalmem;
 104 }
 105
 106 int adns_submit(adns_state ads,
 107                 const char *owner,
 108                 adns_rrtype type,
 109                 adns_queryflags flags,
 110                 void *context,
 111                 adns_query *query_r) {
 112   qcontext ctx;
 113   int id, r, ol;
 114   vbuf vb;
 115   adns_status stat;
 116   const typeinfo *typei;
 117   struct timeval now;
 118
 119   typei= adns__findtype(type);
 120   if (!typei) return adns_s_notimplemented;
 121
 122   ctx.ext= context;
 123   r= gettimeofday(&now,0); if (r) return errno;
 124   id= 0;
 125
 126   adns__vbuf_init(&vb);
 127
 128   ol= strlen(owner);
 129   if (ol<=1 || ol>DNS_MAXDOMAIN+1) { stat= adns_s_domaintoolong; goto xit; }
 130
 131   if (owner[ol-1]=='.' && owner[ol-2]!='\\') { flags &= ~adns_qf_search; ol--; }
 132
 133   stat= adns__mkquery(ads,&vb,&id, owner,ol, typei,flags);
 134
 135  xit:
 136   return adns__internal_submit(ads,query_r, typei,&vb,id, flags,now, stat,&ctx);
 137 }
 138
 139 int adns_synchronous(adns_state ads,
 140                      const char *owner,
 141                      adns_rrtype type,
 142                      adns_queryflags flags,
 143                      adns_answer **answer_r) {
 144   adns_query qu;
 145   int r;
 146
 147   r= adns_submit(ads,owner,type,flags,0,&qu);
 148   if (r) return r;
 149
 150   r= adns_wait(ads,&qu,answer_r,0);
 151   if (r) adns_cancel(qu);
 152
 153   return r;
 154 }
 155
 156 static void *alloc_common(adns_query qu, size_t sz) {
 157   allocnode *an;
 158
 159   if (!sz) return qu; /* Any old pointer will do */
 160   assert(!qu->final_allocspace);
 161   an= malloc(MEM_ROUND(MEM_ROUND(sizeof(*an)) + sz));
 162   if (!an) return 0;
 163   LIST_LINK_TAIL(qu->allocations,an);
 164   return (byte*)an + MEM_ROUND(sizeof(*an));
 165 }
 166
 167 void *adns__alloc_interim(adns_query qu, size_t sz) {
 168   sz= MEM_ROUND(sz);
 169   qu->interim_allocd += sz;
 170   return alloc_common(qu,sz);
 171 }
 172
 173 void *adns__alloc_mine(adns_query qu, size_t sz) {
 174   return alloc_common(qu,MEM_ROUND(sz));
 175 }
 176
 177 void adns__transfer_interim(adns_query from, adns_query to, void *block, size_t sz) {
 178   allocnode *an;
 179
 180   if (!block) return;
 181   an= (void*)((byte*)block - MEM_ROUND(sizeof(*an)));
 182
 183   assert(!to->final_allocspace);
 184   assert(!from->final_allocspace);
 185
 186   LIST_UNLINK(from->allocations,an);
 187   LIST_LINK_TAIL(to->allocations,an);
 188
 189   from->interim_allocd -= sz;
 190   to->interim_allocd += sz;
 191 }
 192
 193 void *adns__alloc_final(adns_query qu, size_t sz) {
 194   /* When we're in the _final stage, we _subtract_ from interim_alloc'd
 195    * each allocation, and use final_allocspace to point to the next free
 196    * bit.
 197    */
 198   void *rp;
 199
 200   sz= MEM_ROUND(sz);
 201   rp= qu->final_allocspace;
 202   assert(rp);
 203   qu->interim_allocd -= sz;
 204   assert(qu->interim_allocd>=0);
 205   qu->final_allocspace= (byte*)rp + sz;
 206   return rp;
 207 }
 208
 209 void adns__reset_cnameonly(adns_query qu) {
 210   /* fixme: cancel children */
 211   assert(!qu->final_allocspace);
 212   qu->answer->nrrs= 0;
 213   qu->answer->rrs= 0;
 214   qu->interim_allocd= qu->answer->cname ? MEM_ROUND(strlen(qu->answer->cname)+1) : 0;
 215 }
 216
 217 static void free_query_allocs(adns_query qu) {
 218   allocnode *an, *ann;
 219   adns_query cqu, ncqu;
 220
 221   for (cqu= qu->children.head; cqu; cqu= ncqu) {
 222     ncqu= cqu->siblings.next;
 223     adns_cancel(cqu);
 224   }
 225   for (an= qu->allocations.head; an; an= ann) { ann= an->next; free(an); }
 226   adns__vbuf_free(&qu->vb);
 227 }
 228
 229 void adns_cancel(adns_query qu) {
 230   switch (qu->state) {
 231   case query_udp: case query_tcpwait: case query_tcpsent:
 232     LIST_UNLINK(qu->ads->timew,qu);
 233     break;
 234   case query_child:
 235     LIST_UNLINK(qu->ads->childw,qu);
 236     break;
 237   case query_done:
 238     LIST_UNLINK(qu->ads->output,qu);
 239     break;
 240   default:
 241     abort();
 242   }
 243   free_query_allocs(qu);
 244   free(qu->answer);
 245   free(qu);
 246 }
 247
 248 static void makefinal_query(adns_query qu) {
 249   adns_answer *ans;
 250   int rrn;
 251
 252   ans= qu->answer;
 253
 254   if (qu->interim_allocd) {
 255     ans= realloc(qu->answer, MEM_ROUND(MEM_ROUND(sizeof(*ans)) + qu->interim_allocd));
 256     if (!ans) goto x_nomem;
 257     qu->answer= ans;
 258   }
 259
 260   qu->final_allocspace= (byte*)ans + MEM_ROUND(sizeof(*ans));
 261   adns__makefinal_str(qu,&ans->cname);
 262
 263   if (ans->nrrs) {
 264     adns__makefinal_block(qu, &ans->rrs.untyped, ans->nrrs*ans->rrsz);
 265
 266     for (rrn=0; rrn<ans->nrrs; rrn++)
 267       qu->typei->makefinal(qu, ans->rrs.bytes + rrn*ans->rrsz);
 268   }
 269
 270   free_query_allocs(qu);
 271   return;
 272
 273  x_nomem:
 274   qu->answer->status= adns_s_nolocalmem;
 275   qu->answer->cname= 0;
 276   adns__reset_cnameonly(qu);
 277   free_query_allocs(qu);
 278 }
 279
 280 void adns__query_done(adns_query qu) {
 281   adns_answer *ans;
 282   adns_query parent;
 283
 284   qu->id= -1;
 285   ans= qu->answer;
 286
 287   if (ans->nrrs && qu->typei->diff_needswap) {
 288     if (!adns__vbuf_ensure(&qu->vb,qu->typei->rrsz)) {
 289       adns__query_fail(qu,adns_s_nolocalmem);
 290       return;
 291     }
 292     adns__isort(ans->rrs.bytes, ans->nrrs, ans->rrsz,
 293                 qu->vb.buf, qu->typei->diff_needswap);
 294   }
 295
 296   parent= qu->parent;
 297   if (parent) {
 298     LIST_UNLINK_PART(parent->children,qu,siblings.);
 299     qu->context.intern.callback(parent,qu);
 300     free_query_allocs(qu);
 301     free(qu);
 302     if (!parent->children.head) adns__query_done(parent);
 303   } else {
 304     makefinal_query(qu);
 305     LIST_LINK_TAIL(qu->ads->output,qu);
 306   }
 307 }
 308
 309 void adns__query_fail(adns_query qu, adns_status stat) {
 310   adns__reset_cnameonly(qu);
 311   qu->answer->status= stat;
 312   adns__query_done(qu);
 313 }
 314
 315 void adns__makefinal_str(adns_query qu, char **strp) {
 316   int l;
 317   char *before, *after;
 318
 319   before= *strp;
 320   if (!before) return;
 321   l= strlen(before)+1;
 322   after= adns__alloc_final(qu,l);
 323   memcpy(after,before,l);
 324   *strp= after;
 325 }
 326
 327 void adns__makefinal_block(adns_query qu, void **blpp, size_t sz) {
 328   void *before, *after;
 329
 330   before= *blpp;
 331   if (!before) return;
 332   after= adns__alloc_final(qu,sz);
 333   memcpy(after,before,sz);
 334   *blpp= after;
 335 }