contrib/bind-9.5.2/lib/bind/resolv/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  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
  56  * Portions Copyright (c) 1996-1999 by Internet Software Consortium.
  57  *
  58  * Permission to use, copy, modify, and distribute this software for any
  59  * purpose with or without fee is hereby granted, provided that the above
  60  * copyright notice and this permission notice appear in all copies.
  61  *
  62  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
  63  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  64  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
  65  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  66  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  67  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
  68  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS 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 1.5 2005/07/28 06:51:50 marka Exp $";
  74 #endif /* LIBC_SCCS and not lint */
  75
  76 #include "port_before.h"
  77 #include <sys/types.h>
  78 #include <sys/param.h>
  79 #include <netinet/in.h>
  80 #include <arpa/nameser.h>
  81 #include <ctype.h>
  82 #include <resolv.h>
  83 #include <stdio.h>
  84 #include <string.h>
  85 #include <unistd.h>
  86 #include "port_after.h"
  87
  88 /*%
  89  * Expand compressed domain name 'src' to full domain name.
  90  *
  91  * \li 'msg' is a pointer to the begining of the message,
  92  * \li 'eom' points to the first location after the message,
  93  * \li 'dst' is a pointer to a buffer of size 'dstsiz' for the result.
  94  * \li Return size of compressed name or -1 if there was an error.
  95  */
  96 int
  97 dn_expand(const u_char *msg, const u_char *eom, const u_char *src,
  98           char *dst, int dstsiz)
  99 {
 100         int n = ns_name_uncompress(msg, eom, src, dst, (size_t)dstsiz);
 101
 102         if (n > 0 && dst[0] == '.')
 103                 dst[0] = '\0';
 104         return (n);
 105 }
 106
 107 /*%
 108  * Pack domain name 'exp_dn' in presentation form into 'comp_dn'.
 109  *
 110  * \li Return the size of the compressed name or -1.
 111  * \li 'length' is the size of the array pointed to by 'comp_dn'.
 112  */
 113 int
 114 dn_comp(const char *src, u_char *dst, int dstsiz,
 115         u_char **dnptrs, u_char **lastdnptr)
 116 {
 117         return (ns_name_compress(src, dst, (size_t)dstsiz,
 118                                  (const u_char **)dnptrs,
 119                                  (const u_char **)lastdnptr));
 120 }
 121
 122 /*%
 123  * Skip over a compressed domain name. Return the size or -1.
 124  */
 125 int
 126 dn_skipname(const u_char *ptr, const u_char *eom) {
 127         const u_char *saveptr = ptr;
 128
 129         if (ns_name_skip(&ptr, eom) == -1)
 130                 return (-1);
 131         return (ptr - saveptr);
 132 }
 133
 134 /*%
 135  * Verify that a domain name uses an acceptable character set.
 136  *
 137  * Note the conspicuous absence of ctype macros in these definitions.  On
 138  * non-ASCII hosts, we can't depend on string literals or ctype macros to
 139  * tell us anything about network-format data.  The rest of the BIND system
 140  * is not careful about this, but for some reason, we're doing it right here.
 141  */
 142 #define PERIOD 0x2e
 143 #define hyphenchar(c) ((c) == 0x2d)
 144 #define bslashchar(c) ((c) == 0x5c)
 145 #define periodchar(c) ((c) == PERIOD)
 146 #define asterchar(c) ((c) == 0x2a)
 147 #define alphachar(c) (((c) >= 0x41 && (c) <= 0x5a) \
 148                    || ((c) >= 0x61 && (c) <= 0x7a))
 149 #define digitchar(c) ((c) >= 0x30 && (c) <= 0x39)
 150
 151 #define borderchar(c) (alphachar(c) || digitchar(c))
 152 #define middlechar(c) (borderchar(c) || hyphenchar(c))
 153 #define domainchar(c) ((c) > 0x20 && (c) < 0x7f)
 154
 155 int
 156 res_hnok(const char *dn) {
 157         int pch = PERIOD, ch = *dn++;
 158
 159         while (ch != '\0') {
 160                 int nch = *dn++;
 161
 162                 if (periodchar(ch)) {
 163                         (void)NULL;
 164                 } else if (periodchar(pch)) {
 165                         if (!borderchar(ch))
 166                                 return (0);
 167                 } else if (periodchar(nch) || nch == '\0') {
 168                         if (!borderchar(ch))
 169                                 return (0);
 170                 } else {
 171                         if (!middlechar(ch))
 172                                 return (0);
 173                 }
 174                 pch = ch, ch = nch;
 175         }
 176         return (1);
 177 }
 178
 179 /*%
 180  * hostname-like (A, MX, WKS) owners can have "*" as their first label
 181  * but must otherwise be as a host name.
 182  */
 183 int
 184 res_ownok(const char *dn) {
 185         if (asterchar(dn[0])) {
 186                 if (periodchar(dn[1]))
 187                         return (res_hnok(dn+2));
 188                 if (dn[1] == '\0')
 189                         return (1);
 190         }
 191         return (res_hnok(dn));
 192 }
 193
 194 /*%
 195  * SOA RNAMEs and RP RNAMEs can have any printable character in their first
 196  * label, but the rest of the name has to look like a host name.
 197  */
 198 int
 199 res_mailok(const char *dn) {
 200         int ch, escaped = 0;
 201
 202         /* "." is a valid missing representation */
 203         if (*dn == '\0')
 204                 return (1);
 205
 206         /* otherwise <label>.<hostname> */
 207         while ((ch = *dn++) != '\0') {
 208                 if (!domainchar(ch))
 209                         return (0);
 210                 if (!escaped && periodchar(ch))
 211                         break;
 212                 if (escaped)
 213                         escaped = 0;
 214                 else if (bslashchar(ch))
 215                         escaped = 1;
 216         }
 217         if (periodchar(ch))
 218                 return (res_hnok(dn));
 219         return (0);
 220 }
 221
 222 /*%
 223  * This function is quite liberal, since RFC1034's character sets are only
 224  * recommendations.
 225  */
 226 int
 227 res_dnok(const char *dn) {
 228         int ch;
 229
 230         while ((ch = *dn++) != '\0')
 231                 if (!domainchar(ch))
 232                         return (0);
 233         return (1);
 234 }
 235
 236 #ifdef BIND_4_COMPAT
 237 /*%
 238  * This module must export the following externally-visible symbols:
 239  *      ___putlong
 240  *      ___putshort
 241  *      __getlong
 242  *      __getshort
 243  * Note that one _ comes from C and the others come from us.
 244  */
 245
 246 #ifdef SOLARIS2
 247 #ifdef  __putlong
 248 #undef  __putlong
 249 #endif
 250 #ifdef  __putshort
 251 #undef  __putshort
 252 #endif
 253 #pragma weak    putlong         =       __putlong
 254 #pragma weak    putshort        =       __putshort
 255 #endif /* SOLARIS2 */
 256
 257 void __putlong(u_int32_t src, u_char *dst) { ns_put32(src, dst); }
 258 void __putshort(u_int16_t src, u_char *dst) { ns_put16(src, dst); }
 259 #ifndef __ultrix__
 260 u_int32_t _getlong(const u_char *src) { return (ns_get32(src)); }
 261 u_int16_t _getshort(const u_char *src) { return (ns_get16(src)); }
 262 #endif /*__ultrix__*/
 263 #endif /*BIND_4_COMPAT*/
 264
 265 #ifdef _LIBC
 266 /*
 267  * Weak aliases for applications that use certain private entry points,
 268  * and fail to include <resolv.h>.
 269  */
 270 #undef dn_comp
 271 __weak_reference(__dn_comp, dn_comp);
 272 #undef dn_expand
 273 __weak_reference(__dn_expand, dn_expand);
 274 #endif
 275 /*! \file */