res_comp.c

   1 /*
   2  * Copyright (c) 1985, 1993
   3  *    The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 /*
  35  * Portions Copyright (c) 1993 by Digital Equipment Corporation.
  36  *
  37  * Permission to use, copy, modify, and distribute this software for any
  38  * purpose with or without fee is hereby granted, provided that the above
  39  * copyright notice and this permission notice appear in all copies, and that
  40  * the name of Digital Equipment Corporation not be used in advertising or
  41  * publicity pertaining to distribution of the document or software without
  42  * specific, written prior permission.
  43  *
  44  * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
  45  * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
  46  * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
  47  * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
  48  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
  49  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
  50  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
  51  * SOFTWARE.
  52  */
  53
  54 /*
  55  * Portions Copyright (c) 1996-1999 by Internet Software Consortium.
  56  *
  57  * Permission to use, copy, modify, and distribute this software for any
  58  * purpose with or without fee is hereby granted, provided that the above
  59  * copyright notice and this permission notice appear in all copies.
  60  *
  61  * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
  62  * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
  63  * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
  64  * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
  65  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
  66  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
  67  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
  68  * SOFTWARE.
  69  */
  70
  71 #if defined(LIBC_SCCS) && !defined(lint)
  72 static const char sccsid[] = "@(#)res_comp.c    8.1 (Berkeley) 6/4/93";
  73 static const char rcsid[] = "$Id: res_comp.c,v 1.1 2006/03/01 19:01:37 majka Exp $";
  74 #endif /* LIBC_SCCS and not lint */
  75
  76 #ifndef __APPLE__
  77 #include "port_before.h"
  78 #endif
  79 #include <sys/types.h>
  80 #include <sys/param.h>
  81 #include <netinet/in.h>
  82 #include <arpa/nameser.h>
  83 #include <ctype.h>
  84 #include <resolv.h>
  85 #include <stdio.h>
  86 #include <string.h>
  87 #include <unistd.h>
  88 #ifndef __APPLE__
  89 #include "port_after.h"
  90 #endif
  91
  92 /*
  93  * Expand compressed domain name 'comp_dn' to full domain name.
  94  * 'msg' is a pointer to the begining of the message,
  95  * 'eomorig' points to the first location after the message,
  96  * 'exp_dn' is a pointer to a buffer of size 'length' for the result.
  97  * Return size of compressed name or -1 if there was an error.
  98  */
  99 int
 100 dn_expand(const u_char *msg, const u_char *eom, const u_char *src,
 101           char *dst, int dstsiz)
 102 {
 103         int n = ns_name_uncompress(msg, eom, src, dst, (size_t)dstsiz);
 104
 105         if (n > 0 && dst[0] == '.')
 106                 dst[0] = '\0';
 107         return (n);
 108 }
 109
 110 /*
 111  * Pack domain name 'exp_dn' in presentation form into 'comp_dn'.
 112  * Return the size of the compressed name or -1.
 113  * 'length' is the size of the array pointed to by 'comp_dn'.
 114  */
 115 int
 116 dn_comp(const char *src, u_char *dst, int dstsiz,
 117         u_char **dnptrs, u_char **lastdnptr)
 118 {
 119         return (ns_name_compress(src, dst, (size_t)dstsiz,
 120                                  (const u_char **)dnptrs,
 121                                  (const u_char **)lastdnptr));
 122 }
 123
 124 /*
 125  * Skip over a compressed domain name. Return the size or -1.
 126  */
 127 int
 128 dn_skipname(const u_char *ptr, const u_char *eom) {
 129         const u_char *saveptr = ptr;
 130
 131         if (ns_name_skip(&ptr, eom) == -1)
 132                 return (-1);
 133         return (ptr - saveptr);
 134 }
 135
 136 /*
 137  * Verify that a domain name uses an acceptable character set.
 138  */
 139
 140 /*
 141  * Note the conspicuous absence of ctype macros in these definitions.  On
 142  * non-ASCII hosts, we can't depend on string literals or ctype macros to
 143  * tell us anything about network-format data.  The rest of the BIND system
 144  * is not careful about this, but for some reason, we're doing it right here.
 145  */
 146 #define PERIOD 0x2e
 147 #define hyphenchar(c) ((c) == 0x2d)
 148 #define bslashchar(c) ((c) == 0x5c)
 149 #define periodchar(c) ((c) == PERIOD)
 150 #define asterchar(c) ((c) == 0x2a)
 151 #define alphachar(c) (((c) >= 0x41 && (c) <= 0x5a) \
 152                    || ((c) >= 0x61 && (c) <= 0x7a))
 153 #define digitchar(c) ((c) >= 0x30 && (c) <= 0x39)
 154
 155 #define borderchar(c) (alphachar(c) || digitchar(c))
 156 #define middlechar(c) (borderchar(c) || hyphenchar(c))
 157 #define domainchar(c) ((c) > 0x20 && (c) < 0x7f)
 158
 159 int
 160 res_hnok(const char *dn) {
 161         int ppch = '\0', pch = PERIOD, ch = *dn++;
 162
 163         while (ch != '\0') {
 164                 int nch = *dn++;
 165
 166                 if (periodchar(ch)) {
 167                         (void)NULL;
 168                 } else if (periodchar(pch)) {
 169                         if (!borderchar(ch))
 170                                 return (0);
 171                 } else if (periodchar(nch) || nch == '\0') {
 172                         if (!borderchar(ch))
 173                                 return (0);
 174                 } else {
 175                         if (!middlechar(ch))
 176                                 return (0);
 177                 }
 178                 ppch = pch, pch = ch, ch = nch;
 179         }
 180         return (1);
 181 }
 182
 183 /*
 184  * hostname-like (A, MX, WKS) owners can have "*" as their first label
 185  * but must otherwise be as a host name.
 186  */
 187 int
 188 res_ownok(const char *dn) {
 189         if (asterchar(dn[0])) {
 190                 if (periodchar(dn[1]))
 191                         return (res_hnok(dn+2));
 192                 if (dn[1] == '\0')
 193                         return (1);
 194         }
 195         return (res_hnok(dn));
 196 }
 197
 198 /*
 199  * SOA RNAMEs and RP RNAMEs can have any printable character in their first
 200  * label, but the rest of the name has to look like a host name.
 201  */
 202 int
 203 res_mailok(const char *dn) {
 204         int ch, escaped = 0;
 205
 206         /* "." is a valid missing representation */
 207         if (*dn == '\0')
 208                 return (1);
 209
 210         /* otherwise <label>.<hostname> */
 211         while ((ch = *dn++) != '\0') {
 212                 if (!domainchar(ch))
 213                         return (0);
 214                 if (!escaped && periodchar(ch))
 215                         break;
 216                 if (escaped)
 217                         escaped = 0;
 218                 else if (bslashchar(ch))
 219                         escaped = 1;
 220         }
 221         if (periodchar(ch))
 222                 return (res_hnok(dn));
 223         return (0);
 224 }
 225
 226 /*
 227  * This function is quite liberal, since RFC 1034's character sets are only
 228  * recommendations.
 229  */
 230 int
 231 res_dnok(const char *dn) {
 232         int ch;
 233
 234         while ((ch = *dn++) != '\0')
 235                 if (!domainchar(ch))
 236                         return (0);
 237         return (1);
 238 }
 239
 240 #ifdef __APPLE__
 241 void putlong(u_int32_t src, u_char *dst) { ns_put32(src, dst); }
 242 void putshort(u_int16_t src, u_char *dst) { ns_put16(src, dst); }
 243 u_int32_t _getlong(const u_char *src) { return (ns_get32(src)); }
 244 u_int16_t _getshort(const u_char *src) { return (ns_get16(src)); }
 245 #else
 246 #ifdef BIND_4_COMPAT
 247 /*
 248  * This module must export the following externally-visible symbols:
 249  *      ___putlong
 250  *      ___putshort
 251  *      __getlong
 252  *      __getshort
 253  * Note that one _ comes from C and the others come from us.
 254  */
 255 void putlong(u_int32_t src, u_char *dst) { ns_put32(src, dst); }
 256 void putshort(u_int16_t src, u_char *dst) { ns_put16(src, dst); }
 257 #ifndef __ultrix__
 258 u_int32_t _getlong(const u_char *src) { return (ns_get32(src)); }
 259 u_int16_t _getshort(const u_char *src) { return (ns_get16(src)); }
 260 #endif /*__ultrix__*/
 261 #endif /*BIND_4_COMPAT*/
 262 #endif /* __APPLE__ */