| 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 | } |