mdw@git.distorted.org.uk Git - adns/blob - client/adnsresfilter.c

   1 /*
   2  * adnsresfilter.c
   3  * - filter which does resolving, not part of the library
   4  */
   5 /*
   6  *  This file is
   7  *    Copyright (C) 1999 Ian Jackson <ian@davenant.greenend.org.uk>
   8  *
   9  *  It is part of adns, which is
  10  *    Copyright (C) 1997-1999 Ian Jackson <ian@davenant.greenend.org.uk>
  11  *    Copyright (C) 1999 Tony Finch <dot@dotat.at>
  12  *
  13  *  This program is free software; you can redistribute it and/or modify
  14  *  it under the terms of the GNU General Public License as published by
  15  *  the Free Software Foundation; either version 2, or (at your option)
  16  *  any later version.
  17  *
  18  *  This program is distributed in the hope that it will be useful,
  19  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  20  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21  *  GNU General Public License for more details.
  22  *
  23  *  You should have received a copy of the GNU General Public License
  24  *  along with this program; if not, write to the Free Software Foundation,
  25  *  Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  26  */
  27
  28 #include <stdio.h>
  29 #include <stdlib.h>
  30 #include <string.h>
  31 #include <errno.h>
  32 #include <search.h>
  33 #include <assert.h>
  34 #include <ctype.h>
  35
  36 #include "adns.h"
  37 #include "config.h"
  38
  39 static void sysfail(const char *what) NONRETURNING;
  40 static void sysfail(const char *what) {
  41   fprintf(stderr,"adnsresfilter: system call failed: %s: %s\n",what,strerror(errno));
  42   exit(2);
  43 }
  44
  45 static void outputerr(void) NONRETURNING;
  46 static void outputerr(void) { sysfail("write to stdout"); }
  47
  48 static void usage(void) {
  49   if (printf("usage: adnsresfilter [<options ...>]\n"
  50              "       adnsresfilter  -h|--help\n"
  51              "options: -b|--brackets\n"
  52              "         -w|--wait\n"
  53              "         -u|--unchecked\n")
  54       == EOF) outputerr();
  55 }
  56
  57 static void usageerr(const char *why) NONRETURNING;
  58 static void usageerr(const char *why) {
  59   fprintf(stderr,"adnsresfilter: bad usage: %s\n",why);
  60   usage();
  61   exit(1);
  62 }
  63
  64 static void adnsfail(const char *what, int e) NONRETURNING;
  65 static void adnsfail(const char *what, int e) {
  66   fprintf(stderr,"adnsresfilter: adns call failed: %s: %s\n",what,strerror(e));
  67   exit(2);
  68 }
  69
  70 static int bracket, forever;
  71 static adns_rrtype rrt= adns_r_ptr;
  72
  73 static struct sockaddr_in sa;
  74 static adns_state ads;
  75
  76 static char buf[14];
  77 static int c, cbyte, inbyte, inbuf;
  78 static unsigned char bytes[4];
  79
  80 struct treething {
  81   unsigned char bytes[4];
  82   adns_query qu;
  83   adns_answer *ans;
  84 };
  85
  86 static struct treething *newthing;
  87 static void *treeroot;
  88
  89 static int comparer(const void *a, const void *b) {
  90   return memcmp(a,b,4);
  91 }
  92
  93 static void restartbuf(void) {
  94   if (inbuf>0) {
  95     buf[inbuf++]= 0;
  96     if (fputs(buf,stdout) < 0) outputerr();
  97   }
  98   inbuf= 0;
  99 }
 100
 101 static void procaddr(void) {
 102   struct treething *foundthing;
 103   void *expectreturn, **searchfound;
 104   int r;
 105
 106   if (!newthing) {
 107     newthing= malloc(sizeof(struct treething));
 108     if (!newthing) sysfail("malloc");
 109     newthing->qu= 0;
 110     newthing->ans= 0;
 111   }
 112
 113   memcpy(newthing->bytes,bytes,4);
 114   searchfound= tsearch(newthing,&treeroot,comparer);
 115   if (!searchfound) sysfail("tsearch");
 116   foundthing= *searchfound;
 117
 118   if (foundthing == newthing) {
 119     newthing= 0;
 120     memcpy(&sa.sin_addr,bytes,4);
 121     r= adns_submit_reverse(ads, (const struct sockaddr*)&sa,
 122                            rrt,0,foundthing,&foundthing->qu);
 123     if (r) adnsfail("submit",r);
 124   }
 125   if (!foundthing->ans) {
 126     expectreturn= foundthing;
 127     r= (forever ? adns_wait : adns_check)
 128       (ads,&foundthing->qu,&foundthing->ans,&expectreturn);
 129     assert(r==EAGAIN || (!r && foundthing->ans && expectreturn==foundthing));
 130   }
 131   if (foundthing->ans && foundthing->ans->nrrs > 0) {
 132     if (fputs(foundthing->ans->rrs.str[0],stdout) < 0) outputerr();
 133     inbuf= 0;
 134   } else {
 135     restartbuf();
 136   }
 137   cbyte= -1;
 138 }
 139
 140 static void startaddr(void) {
 141   bytes[cbyte=0]= 0;
 142   inbyte= 0;
 143 }
 144
 145 static void mustputchar(int c) {
 146   if (putchar(c) == EOF) outputerr();
 147 }
 148
 149 int main(int argc, const char *const *argv) {
 150   const char *arg;
 151   int nbyte, r;
 152
 153   while ((arg= *++argv)) {
 154     if (arg[0] != '-') usageerr("no non-option arguments are allowed");
 155     if (arg[1] == '-') {
 156       if (!strcmp(arg,"--brackets")) {
 157         bracket= 1;
 158       } else if (!strcmp(arg,"--unchecked")) {
 159         rrt= adns_r_ptr_raw;
 160       } else if (!strcmp(arg,"--wait")) {
 161         forever= 1;
 162       } else if (!strcmp(arg,"--help")) {
 163         usage(); exit(0);
 164       } else {
 165         usageerr("unknown long option");
 166       }
 167     } else {
 168       while ((c= *++arg)) {
 169         switch (c) {
 170         case 'b':
 171           bracket= 1;
 172           break;
 173         case 'u':
 174           rrt= adns_r_ptr_raw;
 175           break;
 176         case 'w':
 177           forever= 1;
 178           break;
 179         case 'h':
 180           usage(); exit(0);
 181         default:
 182           usageerr("unknown short option");
 183         }
 184       }
 185     }
 186   }
 187   if (setvbuf(stdout,0,_IOLBF,0)) sysfail("setvbuf stdout");
 188
 189   memset(&sa,0,sizeof(sa));
 190   sa.sin_family= AF_INET;
 191
 192   r= adns_init(&ads,0,0);  if (r) adnsfail("init",r);
 193
 194   cbyte= -1;
 195   inbyte= -1;
 196   inbuf= 0;
 197   if (!bracket) startaddr();
 198   while ((c= getchar()) != EOF) {
 199     if (cbyte==-1 && bracket && c=='[') {
 200       buf[inbuf++]= c;
 201       startaddr();
 202     } else if (cbyte==-1 && !bracket && !isalnum(c)) {
 203       mustputchar(c);
 204       startaddr();
 205     } else if (cbyte>=0 && inbyte<3 && c>='0' && c<='9' &&
 206                (nbyte= bytes[cbyte]*10 + (c-'0')) <= 255) {
 207       bytes[cbyte]= nbyte;
 208       buf[inbuf++]= c;
 209       inbyte++;
 210     } else if (cbyte>=0 && cbyte<3 && inbyte>0 && c=='.') {
 211       bytes[++cbyte]= 0;
 212       buf[inbuf++]= c;
 213       inbyte= 0;
 214     } else if (cbyte==3 && inbyte>0 && bracket && c==']') {
 215       buf[inbuf++]= c;
 216       procaddr();
 217     } else if (cbyte==3 && inbyte>0 && !bracket && !isalnum(c)) {
 218       procaddr();
 219       mustputchar(c);
 220       startaddr();
 221     } else {
 222       restartbuf();
 223       mustputchar(c);
 224       cbyte= -1;
 225       if (!bracket && !isalnum(c)) startaddr();
 226     }
 227   }
 228   if (ferror(stdin) || fclose(stdin)) sysfail("read stdin");
 229   if (cbyte==3 && inbyte>0 && !bracket) procaddr();
 230   if (fclose(stdout)) sysfail("close stdout");
 231   exit(0);
 232 }