dist/dhcp/minires/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. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29
  30 /*
  31  * Portions Copyright (c) 1993 by Digital Equipment Corporation.
  32  *
  33  * Permission to use, copy, modify, and distribute this software for any
  34  * purpose with or without fee is hereby granted, provided that the above
  35  * copyright notice and this permission notice appear in all copies, and that
  36  * the name of Digital Equipment Corporation not be used in advertising or
  37  * publicity pertaining to distribution of the document or software without
  38  * specific, written prior permission.
  39  *
  40  * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
  41  * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
  42  * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
  43  * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
  44  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
  45  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
  46  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
  47  * SOFTWARE.
  48  */
  49
  50 /*
  51  * Portions Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
  52  * Portions Copyright (c) 1996-2003 by Internet Software Consortium
  53  *
  54  * Permission to use, copy, modify, and distribute this software for any
  55  * purpose with or without fee is hereby granted, provided that the above
  56  * copyright notice and this permission notice appear in all copies.
  57  *
  58  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
  59  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  60  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
  61  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  62  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  63  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
  64  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  65  *
  66  *   Internet Systems Consortium, Inc.
  67  *   950 Charter Street
  68  *   Redwood City, CA 94063
  69  *   <info@isc.org>
  70  *   http://www.isc.org/
  71  */
  72
  73 #if defined(LIBC_SCCS) && !defined(lint)
  74 static const char sccsid[] = "@(#)res_comp.c    8.1 (Berkeley) 6/4/93";
  75 static const char rcsid[] = "$Id: res_comp.c,v 1.3 2005/08/11 17:13:26 drochner Exp $";
  76 #endif /* LIBC_SCCS and not lint */
  77
  78 #include <sys/types.h>
  79 #include <sys/param.h>
  80 #include <netinet/in.h>
  81 #include <ctype.h>
  82 #include <stdio.h>
  83 #include <string.h>
  84 #include <unistd.h>
  85 #include <sys/socket.h>
  86
  87 #include "minires/minires.h"
  88 #include "arpa/nameser.h"
  89
  90 /*
  91  * Expand compressed domain name 'comp_dn' to full domain name.
  92  * 'msg' is a pointer to the begining of the message,
  93  * 'eomorig' points to the first location after the message,
  94  * 'exp_dn' is a pointer to a buffer of size 'length' for the result.
  95  * Return size of compressed name or -1 if there was an error.
  96  */
  97 int
  98 dn_expand(const u_char *msg, const u_char *eom, const u_char *src,
  99           char *dst, unsigned dstsiz)
 100 {
 101         int n = ns_name_uncompress(msg, eom, src, dst, (size_t)dstsiz);
 102
 103         if (n > 0 && dst[0] == '.')
 104                 dst[0] = '\0';
 105         return (n);
 106 }
 107
 108 /*
 109  * Pack domain name 'exp_dn' in presentation form into 'comp_dn'.
 110  * Return the size of the compressed name or -1.
 111  * 'length' is the size of the array pointed to by 'comp_dn'.
 112  */
 113 int
 114 dn_comp(const char *src, u_char *dst, unsigned 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
 138 #if 0
 139 /*
 140  * Note the conspicuous absence of ctype macros in these definitions.  On
 141  * non-ASCII hosts, we can't depend on string literals or ctype macros to
 142  * tell us anything about network-format data.  The rest of the BIND system
 143  * is not careful about this, but for some reason, we're doing it right here.
 144  */
 145 #define PERIOD 0x2e
 146 #define hyphenchar(c) ((c) == 0x2d)
 147 #define bslashchar(c) ((c) == 0x5c)
 148 #define periodchar(c) ((c) == PERIOD)
 149 #define asterchar(c) ((c) == 0x2a)
 150 #define alphachar(c) (((c) >= 0x41 && (c) <= 0x5a) \
 151                    || ((c) >= 0x61 && (c) <= 0x7a))
 152 #define digitchar(c) ((c) >= 0x30 && (c) <= 0x39)
 153
 154 #define borderchar(c) (alphachar(c) || digitchar(c))
 155 #define middlechar(c) (borderchar(c) || hyphenchar(c))
 156 #define domainchar(c) ((c) > 0x20 && (c) < 0x7f)
 157
 158 int
 159 res_hnok(const char *dn) {
 160         int ppch = '\0', pch = PERIOD, ch = *dn++;
 161
 162         while (ch != '\0') {
 163                 int nch = *dn++;
 164
 165                 if (periodchar(ch)) {
 166                         (void)NULL;
 167                 } else if (periodchar(pch)) {
 168                         if (!borderchar(ch))
 169                                 return (0);
 170                 } else if (periodchar(nch) || nch == '\0') {
 171                         if (!borderchar(ch))
 172                                 return (0);
 173                 } else {
 174                         if (!middlechar(ch))
 175                                 return (0);
 176                 }
 177                 ppch = pch, pch = ch, ch = nch;
 178         }
 179         return (1);
 180 }
 181
 182 /*
 183  * hostname-like (A, MX, WKS) owners can have "*" as their first label
 184  * but must otherwise be as a host name.
 185  */
 186 int
 187 res_ownok(const char *dn) {
 188         if (asterchar(dn[0])) {
 189                 if (periodchar(dn[1]))
 190                         return (res_hnok(dn+2));
 191                 if (dn[1] == '\0')
 192                         return (1);
 193         }
 194         return (res_hnok(dn));
 195 }
 196
 197 /*
 198  * SOA RNAMEs and RP RNAMEs can have any printable character in their first
 199  * label, but the rest of the name has to look like a host name.
 200  */
 201 int
 202 res_mailok(const char *dn) {
 203         int ch, escaped = 0;
 204
 205         /* "." is a valid missing representation */
 206         if (*dn == '\0')
 207                 return (1);
 208
 209         /* otherwise <label>.<hostname> */
 210         while ((ch = *dn++) != '\0') {
 211                 if (!domainchar(ch))
 212                         return (0);
 213                 if (!escaped && periodchar(ch))
 214                         break;
 215                 if (escaped)
 216                         escaped = 0;
 217                 else if (bslashchar(ch))
 218                         escaped = 1;
 219         }
 220         if (periodchar(ch))
 221                 return (res_hnok(dn));
 222         return (0);
 223 }
 224
 225 /*
 226  * This function is quite liberal, since RFC 1034's character sets are only
 227  * recommendations.
 228  */
 229 int
 230 res_dnok(const char *dn) {
 231         int ch;
 232
 233         while ((ch = *dn++) != '\0')
 234                 if (!domainchar(ch))
 235                         return (0);
 236         return (1);
 237 }
 238 #endif