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   qu->allocations= 0;
  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_dgram= malloc(qumsg_vb->used);
  77   if (!qu->query_dgram) {
  78     adns__query_fail(qu,adns_s_nolocalmem);
  79     return adns_s_ok;
  80   }
  81   memcpy(qu->query_dgram,qumsg_vb->buf,qumsg_vb->used);
  82   qu->vb= *qumsg_vb;
  83   adns__vbuf_init(qumsg_vb);
  84
  85   if (failstat) {
  86     adns__query_fail(qu,failstat);
  87     return adns_s_ok;
  88   }
  89   adns__query_udp(qu,now);
  90   adns__autosys(ads,now);
  91
  92   return adns_s_ok;
  93
  94  x_freequ_nomemory:
  95   free(qu);
  96  x_nomemory:
  97   adns__vbuf_free(qumsg_vb);
  98   return adns_s_nolocalmem;
  99 }
 100
 101 int adns_submit(adns_state ads,
 102                 const char *owner,
 103                 adns_rrtype type,
 104                 adns_queryflags flags,
 105                 void *context,
 106                 adns_query *query_r) {
 107   qcontext ctx;
 108   int id, r, ol;
 109   vbuf vb;
 110   adns_status stat;
 111   const typeinfo *typei;
 112   struct timeval now;
 113
 114   typei= adns__findtype(type);
 115   if (!typei) return adns_s_notimplemented;
 116
 117   ctx.ext= context;
 118   r= gettimeofday(&now,0); if (r) return errno;
 119   id= 0;
 120
 121   adns__vbuf_init(&vb);
 122
 123   ol= strlen(owner);
 124   if (ol<=1 || ol>DNS_MAXDOMAIN+1) { stat= adns_s_invaliddomain; goto xit; }
 125
 126   if (owner[ol-1]=='.' && owner[ol-2]!='\\') { flags &= ~adns_qf_search; ol--; }
 127
 128   stat= adns__mkquery(ads,&vb,&id, owner,ol, typei,flags);
 129
 130  xit:
 131   return adns__internal_submit(ads,query_r, typei,&vb,id, flags,now, stat,&ctx);
 132 }
 133
 134 int adns_synchronous(adns_state ads,
 135                      const char *owner,
 136                      adns_rrtype type,
 137                      adns_queryflags flags,
 138                      adns_answer **answer_r) {
 139   adns_query qu;
 140   int r;
 141
 142   r= adns_submit(ads,owner,type,flags,0,&qu);
 143   if (r) return r;
 144
 145   do {
 146     r= adns_wait(ads,&qu,answer_r,0);
 147   } while (r==EINTR);
 148   if (r) adns_cancel(qu);
 149   return r;
 150 }
 151
 152 void adns_cancel(adns_query query) {
 153   abort(); /* fixme */
 154 }
 155
 156 void *adns__alloc_interim(adns_query qu, size_t sz) {
 157   allocnode *an;
 158
 159   assert(!qu->final_allocspace);
 160   sz= MEM_ROUND(sz);
 161   an= malloc(MEM_ROUND(MEM_ROUND(sizeof(*an)) + sz));
 162   if (!an) {
 163     adns__query_fail(qu,adns_s_nolocalmem);
 164     return 0;
 165   }
 166   qu->interim_allocd += sz;
 167   an->next= qu->allocations;
 168   qu->allocations= an;
 169   return (byte*)an + MEM_ROUND(sizeof(*an));
 170 }
 171
 172 void *adns__alloc_final(adns_query qu, size_t sz) {
 173   /* When we're in the _final stage, we _subtract_ from interim_alloc'd
 174    * each allocation, and use final_allocspace to point to the next free
 175    * bit.
 176    */
 177   void *rp;
 178
 179   sz= MEM_ROUND(sz);
 180   rp= qu->final_allocspace;
 181   assert(rp);
 182   qu->interim_allocd -= sz;
 183   assert(qu->interim_allocd>=0);
 184   qu->final_allocspace= (byte*)rp + sz;
 185   return rp;
 186 }
 187
 188 void adns__reset_cnameonly(adns_query qu) {
 189   assert(qu->final_allocspace);
 190   qu->answer->nrrs= 0;
 191   qu->answer->rrs= 0;
 192   qu->interim_allocd= qu->answer->cname ? MEM_ROUND(strlen(qu->answer->cname)+1) : 0;
 193 }
 194
 195 void adns__query_done(adns_query qu) {
 196   adns_answer *ans;
 197   allocnode *an, *ann;
 198   int i;
 199
 200   qu->answer= ans= realloc(qu->answer,
 201                            MEM_ROUND(MEM_ROUND(sizeof(*ans)) +
 202                                      qu->interim_allocd));
 203   qu->final_allocspace= (byte*)qu->answer + MEM_ROUND(sizeof(*ans));
 204
 205   adns__makefinal_str(qu,&ans->cname);
 206   if (ans->nrrs) {
 207     adns__makefinal_block(qu,&ans->rrs.untyped,ans->rrsz*ans->nrrs);
 208     for (i=0; i<ans->nrrs; i++)
 209       qu->typei->makefinal(qu,ans->rrs.bytes+ans->rrsz*i);
 210   }
 211
 212   for (an= qu->allocations; an; an= ann) { ann= an->next; free(an); }
 213
 214   adns__vbuf_free(&qu->vb);
 215
 216   qu->id= -1;
 217   LIST_LINK_TAIL(qu->ads->output,qu);
 218 }
 219
 220 void adns__query_fail(adns_query qu, adns_status stat) {
 221   adns__reset_cnameonly(qu);
 222   qu->answer->status= stat;
 223   adns__query_done(qu);
 224 }
 225
 226 void adns__makefinal_str(adns_query qu, char **strp) {
 227   int l;
 228   char *before, *after;
 229
 230   before= *strp;
 231   l= strlen(before)+1;
 232   after= adns__alloc_final(qu,l);
 233   memcpy(after,before,l);
 234   *strp= after;
 235 }
 236
 237 void adns__makefinal_block(adns_query qu, void **blpp, size_t sz) {
 238   void *after;
 239
 240   after= adns__alloc_final(qu,sz);
 241   memcpy(after,*blpp,sz);
 242   *blpp= after;
 243 }
 244