lib/libc/resolv/res_comp.c

   1 /*      $NetBSD: res_comp.c,v 1.10 2009/04/12 17:07:17 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. All advertising materials mentioning features or use of this software
  16  *    must display the following acknowledgement:
  17  *      This product includes software developed by the University of
  18  *      California, Berkeley and its contributors.
  19  * 4. Neither the name of the University nor the names of its contributors
  20  *    may be used to endorse or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  */
  35
  36 /*
  37  * Portions Copyright (c) 1993 by Digital Equipment Corporation.
  38  *
  39  * Permission to use, copy, modify, and distribute this software for any
  40  * purpose with or without fee is hereby granted, provided that the above
  41  * copyright notice and this permission notice appear in all copies, and that
  42  * the name of Digital Equipment Corporation not be used in advertising or
  43  * publicity pertaining to distribution of the document or software without
  44  * specific, written prior permission.
  45  *
  46  * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
  47  * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
  48  * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
  49  * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
  50  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
  51  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
  52  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
  53  * SOFTWARE.
  54  */
  55
  56 /*
  57  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
  58  * Portions Copyright (c) 1996-1999 by Internet Software Consortium.
  59  *
  60  * Permission to use, copy, modify, and distribute this software for any
  61  * purpose with or without fee is hereby granted, provided that the above
  62  * copyright notice and this permission notice appear in all copies.
  63  *
  64  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
  65  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  66  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
  67  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  68  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  69  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
  70  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  71  */
  72 #include <sys/cdefs.h>
  73 #if defined(LIBC_SCCS) && !defined(lint)
  74 #ifdef notdef
  75 static const char sccsid[] = "@(#)res_comp.c    8.1 (Berkeley) 6/4/93";
  76 static const char rcsid[] = "Id: res_comp.c,v 1.5 2005/07/28 06:51:50 marka Exp";
  77 #else
  78 __RCSID("$NetBSD: res_comp.c,v 1.10 2009/04/12 17:07:17 christos Exp $");
  79 #endif
  80 #endif /* LIBC_SCCS and not lint */
  81
  82 #include "port_before.h"
  83
  84 #include "namespace.h"
  85 #include <sys/types.h>
  86 #include <sys/param.h>
  87 #include <netinet/in.h>
  88 #include <arpa/nameser.h>
  89 #include <ctype.h>
  90 #include <resolv.h>
  91 #include <stdio.h>
  92 #include <string.h>
  93 #include <unistd.h>
  94 #include "port_after.h"
  95
  96 #ifdef __weak_alias
  97 __weak_alias(dn_expand,_dn_expand)
  98 __weak_alias(dn_comp,__dn_comp)
  99 #ifdef __minix
 100 __weak_alias(dn_skipname,__dn_skipname)
 101 __weak_alias(res_hnok,__res_hnok)
 102 __weak_alias(res_ownok,__res_ownok)
 103 __weak_alias(res_mailok,__res_mailok)
 104 __weak_alias(res_dnok,__res_dnok)
 105 #endif
 106 #endif
 107
 108 /*%
 109  * Expand compressed domain name 'src' to full domain name.
 110  *
 111  * \li 'msg' is a pointer to the begining of the message,
 112  * \li 'eom' points to the first location after the message,
 113  * \li 'dst' is a pointer to a buffer of size 'dstsiz' for the result.
 114  * \li Return size of compressed name or -1 if there was an error.
 115  */
 116 int
 117 dn_expand(const u_char *msg, const u_char *eom, const u_char *src,
 118           char *dst, int dstsiz)
 119 {
 120         int n = ns_name_uncompress(msg, eom, src, dst, (size_t)dstsiz);
 121
 122         if (n > 0 && dst[0] == '.')
 123                 dst[0] = '\0';
 124         return (n);
 125 }
 126
 127 /*%
 128  * Pack domain name 'exp_dn' in presentation form into 'comp_dn'.
 129  *
 130  * \li Return the size of the compressed name or -1.
 131  * \li 'length' is the size of the array pointed to by 'comp_dn'.
 132  */
 133 int
 134 dn_comp(const char *src, u_char *dst, int dstsiz,
 135         u_char **dnptrs, u_char **lastdnptr)
 136 {
 137         return (ns_name_compress(src, dst, (size_t)dstsiz,
 138                                  (const u_char **)dnptrs,
 139                                  (const u_char **)lastdnptr));
 140 }
 141
 142 /*%
 143  * Skip over a compressed domain name. Return the size or -1.
 144  */
 145 int
 146 dn_skipname(const u_char *ptr, const u_char *eom) {
 147         const u_char *saveptr = ptr;
 148
 149         if (ns_name_skip(&ptr, eom) == -1)
 150                 return (-1);
 151         return (ptr - saveptr);
 152 }
 153
 154 /*%
 155  * Verify that a domain name uses an acceptable character set.
 156  *
 157  * Note the conspicuous absence of ctype macros in these definitions.  On
 158  * non-ASCII hosts, we can't depend on string literals or ctype macros to
 159  * tell us anything about network-format data.  The rest of the BIND system
 160  * is not careful about this, but for some reason, we're doing it right here.
 161  */
 162 #define PERIOD 0x2e
 163 #define hyphenchar(c) ((c) == 0x2d)
 164 #define bslashchar(c) ((c) == 0x5c)
 165 #define periodchar(c) ((c) == PERIOD)
 166 #define asterchar(c) ((c) == 0x2a)
 167 #define alphachar(c) (((c) >= 0x41 && (c) <= 0x5a) \
 168                    || ((c) >= 0x61 && (c) <= 0x7a))
 169 #define digitchar(c) ((c) >= 0x30 && (c) <= 0x39)
 170
 171 #define borderchar(c) (alphachar(c) || digitchar(c))
 172 #define middlechar(c) (borderchar(c) || hyphenchar(c))
 173 #define domainchar(c) ((c) > 0x20 && (c) < 0x7f)
 174
 175 int
 176 res_hnok(const char *dn) {
 177         int pch = PERIOD, ch = *dn++;
 178
 179         while (ch != '\0') {
 180                 int nch = *dn++;
 181
 182                 if (periodchar(ch)) {
 183                         ;
 184                 } else if (periodchar(pch)) {
 185                         if (!borderchar(ch))
 186                                 return (0);
 187                 } else if (periodchar(nch) || nch == '\0') {
 188                         if (!borderchar(ch))
 189                                 return (0);
 190                 } else {
 191                         if (!middlechar(ch))
 192                                 return (0);
 193                 }
 194                 pch = ch, ch = nch;
 195         }
 196         return (1);
 197 }
 198
 199 /*%
 200  * hostname-like (A, MX, WKS) owners can have "*" as their first label
 201  * but must otherwise be as a host name.
 202  */
 203 int
 204 res_ownok(const char *dn) {
 205         if (asterchar(dn[0])) {
 206                 if (periodchar(dn[1]))
 207                         return (res_hnok(dn+2));
 208                 if (dn[1] == '\0')
 209                         return (1);
 210         }
 211         return (res_hnok(dn));
 212 }
 213
 214 /*%
 215  * SOA RNAMEs and RP RNAMEs can have any printable character in their first
 216  * label, but the rest of the name has to look like a host name.
 217  */
 218 int
 219 res_mailok(const char *dn) {
 220         int ch, escaped = 0;
 221
 222         /* "." is a valid missing representation */
 223         if (*dn == '\0')
 224                 return (1);
 225
 226         /* otherwise <label>.<hostname> */
 227         while ((ch = *dn++) != '\0') {
 228                 if (!domainchar(ch))
 229                         return (0);
 230                 if (!escaped && periodchar(ch))
 231                         break;
 232                 if (escaped)
 233                         escaped = 0;
 234                 else if (bslashchar(ch))
 235                         escaped = 1;
 236         }
 237         if (periodchar(ch))
 238                 return (res_hnok(dn));
 239         return (0);
 240 }
 241
 242 /*%
 243  * This function is quite liberal, since RFC1034's character sets are only
 244  * recommendations.
 245  */
 246 int
 247 res_dnok(const char *dn) {
 248         int ch;
 249
 250         while ((ch = *dn++) != '\0')
 251                 if (!domainchar(ch))
 252                         return (0);
 253         return (1);
 254 }
 255
 256 #ifdef BIND_4_COMPAT
 257 /*%
 258  * This module must export the following externally-visible symbols:
 259  *      ___putlong
 260  *      ___putshort
 261  *      __getlong
 262  *      __getshort
 263  * Note that one _ comes from C and the others come from us.
 264  */
 265
 266 #ifdef SOLARIS2
 267 #ifdef  __putlong
 268 #undef  __putlong
 269 #endif
 270 #ifdef  __putshort
 271 #undef  __putshort
 272 #endif
 273 #pragma weak    putlong         =       __putlong
 274 #pragma weak    putshort        =       __putshort
 275 #endif /* SOLARIS2 */
 276
 277 void __putlong(u_int32_t src, u_char *dst) { ns_put32(src, dst); }
 278 void __putshort(u_int16_t src, u_char *dst) { ns_put16(src, dst); }
 279 #ifndef __ultrix__
 280 u_int32_t _getlong(const u_char *src) { return (ns_get32(src)); }
 281 u_int16_t _getshort(const u_char *src) { return (ns_get16(src)); }
 282 #endif /*__ultrix__*/
 283 #endif /*BIND_4_COMPAT*/
 284
 285 /*! \file */