mdw@git.distorted.org.uk Git - adns/blob - src/general.c

   1 /*
   2  * general.c
   3  * - diagnostic functions
   4  * - vbuf handling
   5  */
   6 /*
   7  *  This file is part of adns, which is Copyright (C) 1997-1999 Ian Jackson
   8  *
   9  *  This program is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License as published by
  11  *  the Free Software Foundation; either version 2, or (at your option)
  12  *  any later version.
  13  *
  14  *  This program is distributed in the hope that it will be useful,
  15  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  *  GNU General Public License for more details.
  18  *
  19  *  You should have received a copy of the GNU General Public License
  20  *  along with this program; if not, write to the Free Software Foundation,
  21  *  Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  22  */
  23
  24 #include <stdlib.h>
  25 #include <string.h>
  26
  27 #include <sys/types.h>
  28 #include <sys/socket.h>
  29 #include <netinet/in.h>
  30 #include <arpa/inet.h>
  31
  32 #include "internal.h"
  33
  34 /* Core diagnostic functions */
  35
  36 void adns__vdiag(adns_state ads, const char *pfx, adns_initflags prevent,
  37                  int serv, adns_query qu, const char *fmt, va_list al) {
  38   const char *bef, *aft;
  39   vbuf vb;
  40
  41   if (!ads->diagfile ||
  42       (!(ads->iflags & adns_if_debug) && (!prevent || (ads->iflags & prevent))))
  43     return;
  44
  45   fprintf(ads->diagfile,"adns%s: ",pfx);
  46
  47   vfprintf(ads->diagfile,fmt,al);
  48
  49   bef= " (";
  50   aft= "\n";
  51
  52   if (qu && qu->query_dgram) {
  53     adns__vbuf_init(&vb);
  54     fprintf(ads->diagfile,"%sQNAME=%s, QTYPE=%s",
  55             bef,
  56             adns__diag_domain(qu->ads,-1,0, &vb,
  57                               qu->query_dgram,qu->query_dglen,DNS_HDRSIZE),
  58             qu->typei ? qu->typei->rrtname : "<unknown>");
  59     if (qu->typei && qu->typei->fmtname)
  60       fprintf(ads->diagfile,"(%s)",qu->typei->fmtname);
  61     bef=", "; aft=")\n";
  62   }
  63
  64   if (serv>=0) {
  65     fprintf(ads->diagfile,"%sNS=%s",bef,inet_ntoa(ads->servers[serv].addr));
  66     bef=", "; aft=")\n";
  67   }
  68
  69   fputs(aft,ads->diagfile);
  70 }
  71
  72 void adns__debug(adns_state ads, int serv, adns_query qu, const char *fmt, ...) {
  73   va_list al;
  74
  75   va_start(al,fmt);
  76   adns__vdiag(ads," debug",0,serv,qu,fmt,al);
  77   va_end(al);
  78 }
  79
  80 void adns__warn(adns_state ads, int serv, adns_query qu, const char *fmt, ...) {
  81   va_list al;
  82
  83   va_start(al,fmt);
  84   adns__vdiag(ads," warning",adns_if_noerrprint|adns_if_noserverwarn,serv,qu,fmt,al);
  85   va_end(al);
  86 }
  87
  88 void adns__diag(adns_state ads, int serv, adns_query qu, const char *fmt, ...) {
  89   va_list al;
  90
  91   va_start(al,fmt);
  92   adns__vdiag(ads,"",adns_if_noerrprint,serv,qu,fmt,al);
  93   va_end(al);
  94 }
  95
  96 /* vbuf functions */
  97
  98 void adns__vbuf_init(vbuf *vb) {
  99   vb->used= vb->avail= 0; vb->buf= 0;
 100 }
 101
 102 int adns__vbuf_ensure(vbuf *vb, int want) {
 103   void *nb;
 104
 105   if (vb->avail >= want) return 1;
 106   nb= realloc(vb->buf,want); if (!nb) return 0;
 107   vb->buf= nb;
 108   vb->avail= want;
 109   return 1;
 110 }
 111
 112 void adns__vbuf_appendq(vbuf *vb, const byte *data, int len) {
 113   memcpy(vb->buf+vb->used,data,len);
 114   vb->used+= len;
 115 }
 116
 117 int adns__vbuf_append(vbuf *vb, const byte *data, int len) {
 118   int newlen;
 119   void *nb;
 120
 121   newlen= vb->used+len;
 122   if (vb->avail < newlen) {
 123     if (newlen<20) newlen= 20;
 124     newlen <<= 1;
 125     nb= realloc(vb->buf,newlen);
 126     if (!nb) { newlen= vb->used+len; nb= realloc(vb->buf,newlen); }
 127     if (!nb) return 0;
 128     vb->buf= nb;
 129     vb->avail= newlen;
 130   }
 131   adns__vbuf_appendq(vb,data,len);
 132   return 1;
 133 }
 134
 135 int adns__vbuf_appendstr(vbuf *vb, const char *data) {
 136   int l;
 137   l= strlen(data);
 138   return adns__vbuf_append(vb,data,l);
 139 }
 140
 141 void adns__vbuf_free(vbuf *vb) {
 142   free(vb->buf);
 143   adns__vbuf_init(vb);
 144 }
 145
 146 /* Additional diagnostic functions */
 147
 148 const char *adns__diag_domain(adns_state ads, int serv, adns_query qu,
 149                               vbuf *vb, const byte *dgram, int dglen, int cbyte) {
 150   adns_status st;
 151
 152   st= adns__parse_domain(ads,serv,qu,vb, pdf_quoteok, dgram,dglen,&cbyte,dglen);
 153   if (st == adns_s_nomemory) {
 154     return "<cannot report domain... out of memory>";
 155   }
 156   if (st) {
 157     vb->used= 0;
 158     if (!(adns__vbuf_appendstr(vb,"<bad format... ") &&
 159           adns__vbuf_appendstr(vb,adns_strerror(st)) &&
 160           adns__vbuf_appendstr(vb,">") &&
 161           adns__vbuf_append(vb,"",1))) {
 162       return "<cannot report bad format... out of memory>";
 163     }
 164   }
 165   if (!vb->used) {
 166     adns__vbuf_appendstr(vb,"<truncated ...>");
 167     adns__vbuf_append(vb,"",1);
 168   }
 169   return vb->buf;
 170 }
 171
 172 adns_status adns_rr_info(adns_rrtype type,
 173                          const char **rrtname_r, const char **fmtname_r,
 174                          int *len_r,
 175                          const void *datap, char **data_r) {
 176   const typeinfo *typei;
 177   vbuf vb;
 178   adns_status st;
 179
 180   typei= adns__findtype(type);
 181   if (!typei) return adns_s_unknownrrtype;
 182
 183   if (rrtname_r) *rrtname_r= typei->rrtname;
 184   if (fmtname_r) *fmtname_r= typei->fmtname;
 185   if (len_r) *len_r= typei->rrsz;
 186
 187   if (!datap) return adns_s_ok;
 188
 189   adns__vbuf_init(&vb);
 190   st= typei->convstring(&vb,datap);
 191   if (st) goto x_freevb;
 192   if (!adns__vbuf_append(&vb,"",1)) { st= adns_s_nomemory; goto x_freevb; }
 193   assert(strlen(vb.buf) == vb.used-1);
 194   *data_r= realloc(vb.buf,vb.used);
 195   if (!*data_r) *data_r= vb.buf;
 196   return adns_s_ok;
 197
 198  x_freevb:
 199   adns__vbuf_free(&vb);
 200   return st;
 201 }
 202
 203 #define SINFO(n,s) { adns_s_##n, s }
 204
 205 static const struct sinfo {
 206   adns_status st;
 207   const char *string;
 208 } sinfos[]= {
 209   SINFO(  ok,                  "OK"                                            ),
 210
 211   SINFO(  nomemory,            "Out of memory"                                 ),
 212   SINFO(  unknownrrtype,       "Query not implemented in DNS library"          ),
 213
 214   SINFO(  timeout,             "DNS query timed out"                           ),
 215   SINFO(  allservfail,         "All nameservers failed"                        ),
 216   SINFO(  norecurse,           "Recursion denied by nameserver"                ),
 217   SINFO(  invalidresponse,     "Nameserver sent bad response"                  ),
 218   SINFO(  unknownformat,       "Nameserver used unknown format"                ),
 219
 220   SINFO(  rcodeservfail,       "Nameserver reports failure"                    ),
 221   SINFO(  rcodeformaterror,    "Query not understood by nameserver"            ),
 222   SINFO(  rcodenotimplemented, "Query not implemented by nameserver"           ),
 223   SINFO(  rcoderefused,        "Query refused by nameserver"                   ),
 224   SINFO(  rcodeunknown,        "Nameserver sent unknown response code"         ),
 225
 226   SINFO(  inconsistent,        "Inconsistent resource records in DNS"          ),
 227   SINFO(  prohibitedcname,     "DNS data refers to an alias"                   ),
 228   SINFO(  answerdomaininvalid, "Found syntactically invalid domain name"       ),
 229   SINFO(  answerdomaintoolong, "Found overly-long domain name"                 ),
 230   SINFO(  invaliddata,         "Found invalid DNS data"                        ),
 231
 232   SINFO(  querydomainwrong,    "Domain invalid for particular DNS query type"  ),
 233   SINFO(  querydomaininvalid,  "Domain name is syntactically invalid"          ),
 234   SINFO(  querydomaintoolong,  "Domain name is too long"                       ),
 235
 236   SINFO(  nxdomain,            "No such domain"                                ),
 237   SINFO(  nodata,              "No such data"                                  ),
 238 };
 239
 240 static int si_compar(const void *key, const void *elem) {
 241   const adns_status *st= key;
 242   const struct sinfo *si= elem;
 243
 244   return *st < si->st ? -1 : *st > si->st ? 1 : 0;
 245 }
 246
 247 const char *adns_strerror(adns_status st) {
 248   static char buf[100];
 249
 250   const struct sinfo *si;
 251
 252   si= bsearch(&st,sinfos,sizeof(sinfos)/sizeof(*si),sizeof(*si),si_compar);
 253   if (si) return si->string;
 254
 255   snprintf(buf,sizeof(buf),"code %d",st);
 256   return buf;
 257 }
 258
 259 void adns__isort(void *array, int nobjs, int sz, void *tempbuf,
 260                  int (*needswap)(void *context, const void *a, const void *b),
 261                  void *context) {
 262   byte *data= array;
 263   int i, place;
 264
 265   for (i=0; i<nobjs; i++) {
 266     for (place= i;
 267          place>0 && needswap(context, data + (place-1)*sz, data + i*sz);
 268          place--);
 269     if (place != i) {
 270       memcpy(tempbuf, data + i*sz, sz);
 271       memmove(data + (place+1)*sz, data + place*sz, (i-place)*sz);
 272       memcpy(data + place*sz, tempbuf, sz);
 273     }
 274   }
 275 }
 276
 277 /* SIGPIPE protection. */
 278
 279 void adns__sigpipe_protect(adns_state ads) {
 280   sigset_t toblock;
 281   struct sigaction sa;
 282   int r;
 283
 284   if (ads->iflags & adns_if_nosigpipe) return;
 285
 286   sigfillset(&toblock);
 287   sigdelset(&toblock,SIGPIPE);
 288
 289   sa.sa_handler= SIG_IGN;
 290   sigfillset(&sa.sa_mask);
 291   sa.sa_flags= 0;
 292
 293   r= sigprocmask(SIG_SETMASK,&toblock,&ads->stdsigmask); assert(!r);
 294   r= sigaction(SIGPIPE,&sa,&ads->stdsigpipe); assert(!r);
 295 }
 296
 297 void adns__sigpipe_unprotect(adns_state ads) {
 298   int r;
 299
 300   if (ads->iflags & adns_if_nosigpipe) return;
 301
 302   r= sigaction(SIGPIPE,&ads->stdsigpipe,0); assert(!r);
 303   r= sigprocmask(SIG_SETMASK,&ads->stdsigmask,0); assert(!r);
 304 }