src/kits/network/netresolv/resolv/res_comp.c

   1 /*      $NetBSD: res_comp.c,v 1.13 2015/02/24 17:56:20 christos Exp $   */
   2
   3 /*
   4  * Copyright (c) 1985, 1993
   5  *    The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 /*
  33  * Portions Copyright (c) 1993 by Digital Equipment Corporation.
  34  *
  35  * Permission to use, copy, modify, and distribute this software for any
  36  * purpose with or without fee is hereby granted, provided that the above
  37  * copyright notice and this permission notice appear in all copies, and that
  38  * the name of Digital Equipment Corporation not be used in advertising or
  39  * publicity pertaining to distribution of the document or software without
  40  * specific, written prior permission.
  41  *
  42  * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
  43  * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
  44  * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
  45  * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
  46  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
  47  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
  48  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
  49  * SOFTWARE.
  50  */
  51
  52 /*
  53  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
  54  * Portions Copyright (c) 1996-1999 by Internet Software Consortium.
  55  *
  56  * Permission to use, copy, modify, and distribute this software for any
  57  * purpose with or without fee is hereby granted, provided that the above
  58  * copyright notice and this permission notice appear in all copies.
  59  *
  60  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
  61  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  62  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
  63  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  64  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  65  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
  66  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  67  */
  68
  69 #if defined(LIBC_SCCS) && !defined(lint)
  70 static const char sccsid[] = "@(#)res_comp.c    8.1 (Berkeley) 6/4/93";
  71 static const char rcsid[] = "$Id: res_comp.c,v 1.5 2005/07/28 06:51:50 marka Exp $";
  72 #endif /* LIBC_SCCS and not lint */
  73
  74 #include "port_before.h"
  75 #include <sys/types.h>
  76 #include <sys/param.h>
  77 #include <netinet/in.h>
  78 #include <arpa/nameser.h>
  79 #include <assert.h>
  80 #include <ctype.h>
  81 #include <resolv.h>
  82 #include <stdio.h>
  83 #include <string.h>
  84 #include <unistd.h>
  85 #include "port_after.h"
  86
  87 #ifdef __weak_alias
  88 __weak_alias(dn_expand,_dn_expand)
  89 __weak_alias(dn_comp,__dn_comp)
  90 #if 0
  91 __weak_alias(dn_skipname,__dn_skipname)
  92 __weak_alias(res_hnok,__res_hnok)
  93 __weak_alias(res_ownok,__res_ownok)
  94 __weak_alias(res_mailok,__res_mailok)
  95 __weak_alias(res_dnok,__res_dnok)
  96 #endif
  97 #endif
  98
  99 /*%
 100  * Expand compressed domain name 'src' to full domain name.
 101  *
 102  * \li 'msg' is a pointer to the begining of the message,
 103  * \li 'eom' points to the first location after the message,
 104  * \li 'dst' is a pointer to a buffer of size 'dstsiz' for the result.
 105  * \li Return size of compressed name or -1 if there was an error.
 106  */
 107 int
 108 dn_expand(const u_char *msg, const u_char *eom, const u_char *src,
 109           char *dst, int dstsiz)
 110 {
 111         int n = ns_name_uncompress(msg, eom, src, dst, (size_t)dstsiz);
 112
 113         if (n > 0 && dst[0] == '.')
 114                 dst[0] = '\0';
 115         return (n);
 116 }
 117
 118 /*%
 119  * Pack domain name 'exp_dn' in presentation form into 'comp_dn'.
 120  *
 121  * \li Return the size of the compressed name or -1.
 122  * \li 'length' is the size of the array pointed to by 'comp_dn'.
 123  */
 124 int
 125 dn_comp(const char *src, u_char *dst, int dstsiz,
 126         u_char **dnptrs, u_char **lastdnptr)
 127 {
 128         return (ns_name_compress(src, dst, (size_t)dstsiz,
 129                                  (void *)dnptrs,
 130                                  (void *)lastdnptr));
 131 }
 132
 133 /*%
 134  * Skip over a compressed domain name. Return the size or -1.
 135  */
 136 int
 137 dn_skipname(const u_char *ptr, const u_char *eom) {
 138         const u_char *saveptr = ptr;
 139
 140         if (ns_name_skip(&ptr, eom) == -1)
 141                 return (-1);
 142         assert(INT_MIN <= (ptr - saveptr) && (ptr - saveptr) <= INT_MAX);
 143         return (int)(ptr - saveptr);
 144 }
 145
 146 /*%
 147  * Verify that a domain name uses an acceptable character set.
 148  *
 149  * Note the conspicuous absence of ctype macros in these definitions.  On
 150  * non-ASCII hosts, we can't depend on string literals or ctype macros to
 151  * tell us anything about network-format data.  The rest of the BIND system
 152  * is not careful about this, but for some reason, we're doing it right here.
 153  */
 154 #define PERIOD 0x2e
 155 #define hyphenchar(c) ((c) == 0x2d || (c) == 0x5f)
 156 #define bslashchar(c) ((c) == 0x5c)
 157 #define periodchar(c) ((c) == PERIOD)
 158 #define asterchar(c) ((c) == 0x2a)
 159 #define alphachar(c) (((c) >= 0x41 && (c) <= 0x5a) \
 160                    || ((c) >= 0x61 && (c) <= 0x7a))
 161 #define digitchar(c) ((c) >= 0x30 && (c) <= 0x39)
 162
 163 #define borderchar(c) (alphachar(c) || digitchar(c))
 164 #define middlechar(c) (borderchar(c) || hyphenchar(c))
 165 #define domainchar(c) ((c) > 0x20 && (c) < 0x7f)
 166
 167 int
 168 res_hnok(const char *dn) {
 169         int pch = PERIOD, ch = *dn++;
 170
 171         while (ch != '\0') {
 172                 int nch = *dn++;
 173
 174                 if (periodchar(ch)) {
 175                         ;
 176                 } else if (periodchar(pch)) {
 177                         if (!borderchar(ch))
 178                                 return (0);
 179                 } else if (periodchar(nch) || nch == '\0') {
 180                         if (!borderchar(ch))
 181                                 return (0);
 182                 } else {
 183                         if (!middlechar(ch))
 184                                 return (0);
 185                 }
 186                 pch = ch, ch = nch;
 187         }
 188         return (1);
 189 }
 190
 191 /*%
 192  * hostname-like (A, MX, WKS) owners can have "*" as their first label
 193  * but must otherwise be as a host name.
 194  */
 195 int
 196 res_ownok(const char *dn) {
 197         if (asterchar(dn[0])) {
 198                 if (periodchar(dn[1]))
 199                         return (res_hnok(dn+2));
 200                 if (dn[1] == '\0')
 201                         return (1);
 202         }
 203         return (res_hnok(dn));
 204 }
 205
 206 /*%
 207  * SOA RNAMEs and RP RNAMEs can have any printable character in their first
 208  * label, but the rest of the name has to look like a host name.
 209  */
 210 int
 211 res_mailok(const char *dn) {
 212         int ch, escaped = 0;
 213
 214         /* "." is a valid missing representation */
 215         if (*dn == '\0')
 216                 return (1);
 217
 218         /* otherwise <label>.<hostname> */
 219         while ((ch = *dn++) != '\0') {
 220                 if (!domainchar(ch))
 221                         return (0);
 222                 if (!escaped && periodchar(ch))
 223                         break;
 224                 if (escaped)
 225                         escaped = 0;
 226                 else if (bslashchar(ch))
 227                         escaped = 1;
 228         }
 229         if (periodchar(ch))
 230                 return (res_hnok(dn));
 231         return (0);
 232 }
 233
 234 /*%
 235  * This function is quite liberal, since RFC1034's character sets are only
 236  * recommendations.
 237  */
 238 int
 239 res_dnok(const char *dn) {
 240         int ch;
 241
 242         while ((ch = *dn++) != '\0')
 243                 if (!domainchar(ch))
 244                         return (0);
 245         return (1);
 246 }
 247
 248 #ifdef BIND_4_COMPAT
 249 /*%
 250  * This module must export the following externally-visible symbols:
 251  *      ___putlong
 252  *      ___putshort
 253  *      __getlong
 254  *      __getshort
 255  * Note that one _ comes from C and the others come from us.
 256  */
 257
 258 #ifdef SOLARIS2
 259 #ifdef  __putlong
 260 #undef  __putlong
 261 #endif
 262 #ifdef  __putshort
 263 #undef  __putshort
 264 #endif
 265 #pragma weak    putlong         =       __putlong
 266 #pragma weak    putshort        =       __putshort
 267 #endif /* SOLARIS2 */
 268
 269 void __putlong(u_int32_t src, u_char *dst) { ns_put32(src, dst); }
 270 void __putshort(u_int16_t src, u_char *dst) { ns_put16(src, dst); }
 271 #endif /*BIND_4_COMPAT*/
 272
 273 #ifndef __ultrix__
 274 u_int32_t _getlong(const u_char *src) { return (ns_get32(src)); }
 275 u_int16_t _getshort(const u_char *src) { return (ns_get16(src)); }
 276 #endif /*__ultrix__*/
 277
 278 /*! \file */