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 #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_nolocalmem);
  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) {
  92     adns__query_fail(qu,failstat);
  93     return adns_s_ok;
  94   }
  95   adns__query_udp(qu,now);
  96   adns__autosys(ads,now);
  97
  98   return adns_s_ok;
  99
 100  x_freequ_nomemory:
 101   free(qu);
 102  x_nomemory:
 103   adns__vbuf_free(qumsg_vb);
 104   return adns_s_nolocalmem;
 105 }
 106
 107 int adns_submit(adns_state ads,
 108                 const char *owner,
 109                 adns_rrtype type,
 110                 adns_queryflags flags,
 111                 void *context,
 112                 adns_query *query_r) {
 113   qcontext ctx;
 114   int id, r, ol;
 115   vbuf vb;
 116   adns_status stat;
 117   const typeinfo *typei;
 118   struct timeval now;
 119
 120   typei= adns__findtype(type);
 121   if (!typei) return adns_s_notimplemented;
 122
 123   ctx.ext= context;
 124   ctx.callback= 0;
 125   memset(&ctx.info,0,sizeof(ctx.info));
 126
 127   r= gettimeofday(&now,0); if (r) return errno;
 128   id= 0;
 129
 130   adns__vbuf_init(&vb);
 131
 132   ol= strlen(owner);
 133   if (ol<=1 || ol>DNS_MAXDOMAIN+1) { stat= adns_s_domaintoolong; goto xit; }
 134
 135   if (owner[ol-1]=='.' && owner[ol-2]!='\\') { flags &= ~adns_qf_search; ol--; }
 136
 137   stat= adns__mkquery(ads,&vb,&id, owner,ol, typei,flags);
 138
 139  xit:
 140   return adns__internal_submit(ads,query_r, typei,&vb,id, flags,now, stat,&ctx);
 141 }
 142
 143 int adns_synchronous(adns_state ads,
 144                      const char *owner,
 145                      adns_rrtype type,
 146                      adns_queryflags flags,
 147                      adns_answer **answer_r) {
 148   adns_query qu;
 149   int r;
 150
 151   r= adns_submit(ads,owner,type,flags,0,&qu);
 152   if (r) return r;
 153
 154   r= adns_wait(ads,&qu,answer_r,0);
 155   if (r) adns_cancel(qu);
 156
 157   return r;
 158 }
 159
 160 static void *alloc_common(adns_query qu, size_t sz) {
 161   allocnode *an;
 162
 163   if (!sz) return qu; /* Any old pointer will do */
 164   assert(!qu->final_allocspace);
 165   an= malloc(MEM_ROUND(MEM_ROUND(sizeof(*an)) + sz));
 166   if (!an) return 0;
 167   LIST_LINK_TAIL(qu->allocations,an);
 168   return (byte*)an + MEM_ROUND(sizeof(*an));
 169 }
 170
 171 void *adns__alloc_interim(adns_query qu, size_t sz) {
 172   sz= MEM_ROUND(sz);
 173   qu->interim_allocd += sz;
 174   return alloc_common(qu,sz);
 175 }
 176
 177 void *adns__alloc_mine(adns_query qu, size_t sz) {
 178   return alloc_common(qu,MEM_ROUND(sz));
 179 }
 180
 181 void adns__transfer_interim(adns_query from, adns_query to, void *block, size_t sz) {
 182   allocnode *an;
 183
 184   if (!block) return;
 185   an= (void*)((byte*)block - MEM_ROUND(sizeof(*an)));
 186
 187   assert(!to->final_allocspace);
 188   assert(!from->final_allocspace);
 189
 190   LIST_UNLINK(from->allocations,an);
 191   LIST_LINK_TAIL(to->allocations,an);
 192
 193   from->interim_allocd -= sz;
 194   to->interim_allocd += sz;
 195 }
 196
 197 void *adns__alloc_final(adns_query qu, size_t sz) {
 198   /* When we're in the _final stage, we _subtract_ from interim_alloc'd
 199    * each allocation, and use final_allocspace to point to the next free
 200    * bit.
 201    */
 202   void *rp;
 203
 204   sz= MEM_ROUND(sz);
 205   rp= qu->final_allocspace;
 206   assert(rp);
 207   qu->interim_allocd -= sz;
 208   assert(qu->interim_allocd>=0);
 209   qu->final_allocspace= (byte*)rp + sz;
 210   return rp;
 211 }
 212
 213 static void cancel_children(adns_query qu) {
 214   adns_query cqu, ncqu;
 215
 216   for (cqu= qu->children.head; cqu; cqu= ncqu) {
 217     ncqu= cqu->siblings.next;
 218     adns_cancel(cqu);
 219   }
 220   LIST_INIT(qu->children);
 221 }
 222
 223 void adns__reset_cnameonly(adns_query qu) {
 224   assert(!qu->final_allocspace);
 225   cancel_children(qu);
 226   qu->answer->nrrs= 0;
 227   qu->answer->rrs= 0;
 228   qu->interim_allocd= qu->answer->cname ? MEM_ROUND(strlen(qu->answer->cname)+1) : 0;
 229 }
 230
 231 static void free_query_allocs(adns_query qu) {
 232   allocnode *an, *ann;
 233
 234   cancel_children(qu);
 235   for (an= qu->allocations.head; an; an= ann) { ann= an->next; free(an); }
 236   adns__vbuf_free(&qu->vb);
 237 }
 238
 239 void adns_cancel(adns_query qu) {
 240   switch (qu->state) {
 241   case query_udp: case query_tcpwait: case query_tcpsent:
 242     LIST_UNLINK(qu->ads->timew,qu);
 243     break;
 244   case query_child:
 245     LIST_UNLINK(qu->ads->childw,qu);
 246     break;
 247   case query_done:
 248     LIST_UNLINK(qu->ads->output,qu);
 249     break;
 250   default:
 251     abort();
 252   }
 253   free_query_allocs(qu);
 254   free(qu->answer);
 255   free(qu);
 256 }
 257
 258 static void makefinal_query(adns_query qu) {
 259   adns_answer *ans;
 260   int rrn;
 261
 262   ans= qu->answer;
 263
 264   if (qu->interim_allocd) {
 265     ans= realloc(qu->answer, MEM_ROUND(MEM_ROUND(sizeof(*ans)) + qu->interim_allocd));
 266     if (!ans) goto x_nomem;
 267     qu->answer= ans;
 268   }
 269
 270   qu->final_allocspace= (byte*)ans + MEM_ROUND(sizeof(*ans));
 271   adns__makefinal_str(qu,&ans->cname);
 272
 273   if (ans->nrrs) {
 274     adns__makefinal_block(qu, &ans->rrs.untyped, ans->nrrs*ans->rrsz);
 275
 276     for (rrn=0; rrn<ans->nrrs; rrn++)
 277       qu->typei->makefinal(qu, ans->rrs.bytes + rrn*ans->rrsz);
 278   }
 279
 280   free_query_allocs(qu);
 281   return;
 282
 283  x_nomem:
 284   qu->answer->status= adns_s_nolocalmem;
 285   qu->answer->cname= 0;
 286   adns__reset_cnameonly(qu);
 287   free_query_allocs(qu);
 288 }
 289
 290 void adns__query_done(adns_query qu) {
 291   adns_answer *ans;
 292   adns_query parent;
 293
 294   qu->id= -1;
 295   ans= qu->answer;
 296
 297   if (ans->nrrs && qu->typei->diff_needswap) {
 298     if (!adns__vbuf_ensure(&qu->vb,qu->typei->rrsz)) {
 299       adns__query_fail(qu,adns_s_nolocalmem);
 300       return;
 301     }
 302     adns__isort(ans->rrs.bytes, ans->nrrs, ans->rrsz,
 303                 qu->vb.buf, qu->typei->diff_needswap);
 304   }
 305
 306   parent= qu->parent;
 307   if (parent) {
 308     LIST_UNLINK_PART(parent->children,qu,siblings.);
 309     qu->ctx.callback(parent,qu);
 310     free_query_allocs(qu);
 311     free(qu);
 312   } else {
 313     makefinal_query(qu);
 314     LIST_LINK_TAIL(qu->ads->output,qu);
 315   }
 316 }
 317
 318 void adns__query_fail(adns_query qu, adns_status stat) {
 319   adns__reset_cnameonly(qu);
 320   qu->answer->status= stat;
 321   adns__query_done(qu);
 322 }
 323
 324 void adns__makefinal_str(adns_query qu, char **strp) {
 325   int l;
 326   char *before, *after;
 327
 328   before= *strp;
 329   if (!before) return;
 330   l= strlen(before)+1;
 331   after= adns__alloc_final(qu,l);
 332   memcpy(after,before,l);
 333   *strp= after;
 334 }
 335
 336 void adns__makefinal_block(adns_query qu, void **blpp, size_t sz) {
 337   void *before, *after;
 338
 339   before= *blpp;
 340   if (!before) return;
 341   after= adns__alloc_final(qu,sz);
 342   memcpy(after,before,sz);
 343   *blpp= after;
 344 }