StdLib/BsdSocketLib/res_comp.c

   1 /*
   2  * Copyright (c) 1985, 1993
   3  *    The Regents of the University of California.  All rights reserved.
   4  *
   5  * Portions copyright (c) 1999, 2000
   6  * Intel Corporation.
   7  * All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  *
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  *
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in the
  18  *    documentation and/or other materials provided with the distribution.
  19  *
  20  * 3. All advertising materials mentioning features or use of this software
  21  *    must display the following acknowledgement:
  22  *
  23  *    This product includes software developed by the University of
  24  *    California, Berkeley, Intel Corporation, and its contributors.
  25  *
  26  * 4. Neither the name of University, Intel Corporation, or their respective
  27  *    contributors may be used to endorse or promote products derived from
  28  *    this software without specific prior written permission.
  29  *
  30  * THIS SOFTWARE IS PROVIDED BY THE REGENTS, INTEL CORPORATION AND
  31  * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING,
  32  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  33  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS,
  34  * INTEL CORPORATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  35  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  36  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  37  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  38  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  39  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  40  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  41  *
  42  */
  43
  44 /*
  45  * Portions Copyright (c) 1993 by Digital Equipment Corporation.
  46  *
  47  * Permission to use, copy, modify, and distribute this software for any
  48  * purpose with or without fee is hereby granted, provided that the above
  49  * copyright notice and this permission notice appear in all copies, and that
  50  * the name of Digital Equipment Corporation not be used in advertising or
  51  * publicity pertaining to distribution of the document or software without
  52  * specific, written prior permission.
  53  *
  54  * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
  55  * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
  56  * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
  57  * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
  58  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
  59  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
  60  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
  61  * SOFTWARE.
  62  */
  63
  64 /*
  65  * Portions Copyright (c) 1996 by Internet Software Consortium.
  66  *
  67  * Permission to use, copy, modify, and distribute this software for any
  68  * purpose with or without fee is hereby granted, provided that the above
  69  * copyright notice and this permission notice appear in all copies.
  70  *
  71  * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
  72  * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
  73  * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
  74  * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
  75  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
  76  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
  77  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
  78  * SOFTWARE.
  79  */
  80
  81 #if defined(LIBC_SCCS) && !defined(lint)
  82 static char sccsid[] = "@(#)res_comp.c  8.1 (Berkeley) 6/4/93";
  83 static char orig_rcsid[] = "From: Id: res_comp.c,v 8.11 1997/05/21 19:31:04 halley Exp $";
  84 static char rcsid[] = "$Id: res_comp.c,v 1.1.1.1 2003/11/19 01:51:35 kyu3 Exp $";
  85 #endif /* LIBC_SCCS and not lint */
  86
  87 #include <sys/types.h>
  88 #include <sys/param.h>
  89 #include <netinet/in.h>
  90 #include <arpa/nameser.h>
  91 #include <ctype.h>
  92 #include <resolv.h>
  93 #include <stdio.h>
  94 #include <string.h>
  95 #include <unistd.h>
  96
  97 #define BIND_4_COMPAT
  98
  99 /*
 100  * Expand compressed domain name 'comp_dn' to full domain name.
 101  * 'msg' is a pointer to the begining of the message,
 102  * 'eomorig' points to the first location after the message,
 103  * 'exp_dn' is a pointer to a buffer of size 'length' for the result.
 104  * Return size of compressed name or -1 if there was an error.
 105  */
 106 int
 107 dn_expand(const u_char *msg, const u_char *eom, const u_char *src,
 108       char *dst, int dstsiz)
 109 {
 110     int n = ns_name_uncompress(msg, eom, src, dst, (size_t)dstsiz);
 111
 112     if (n > 0 && dst[0] == '.')
 113         dst[0] = '\0';
 114     return (n);
 115 }
 116
 117 /*
 118  * Pack domain name 'exp_dn' in presentation form into 'comp_dn'.
 119  * Return the size of the compressed name or -1.
 120  * 'length' is the size of the array pointed to by 'comp_dn'.
 121  */
 122 int
 123 dn_comp(const char *src, u_char *dst, int dstsiz,
 124     u_char **dnptrs, u_char **lastdnptr)
 125 {
 126     return (ns_name_compress(src, dst, (size_t)dstsiz,
 127                  (const u_char **)dnptrs,
 128                  (const u_char **)lastdnptr));
 129 }
 130
 131 /*
 132  * Skip over a compressed domain name. Return the size or -1.
 133  */
 134 int
 135 dn_skipname(const u_char *ptr, const u_char *eom) {
 136     const u_char *saveptr = ptr;
 137
 138     if (ns_name_skip(&ptr, eom) == -1)
 139         return (-1);
 140     return ((int)(ptr - saveptr));
 141 }
 142
 143 /*
 144  * Verify that a domain name uses an acceptable character set.
 145  */
 146
 147 /*
 148  * Note the conspicuous absence of ctype macros in these definitions.  On
 149  * non-ASCII hosts, we can't depend on string literals or ctype macros to
 150  * tell us anything about network-format data.  The rest of the BIND system
 151  * is not careful about this, but for some reason, we're doing it right here.
 152  */
 153 #define PERIOD 0x2e
 154 #define hyphenchar(c) ((c) == 0x2d)
 155 #define bslashchar(c) ((c) == 0x5c)
 156 #define periodchar(c) ((c) == PERIOD)
 157 #define asterchar(c) ((c) == 0x2a)
 158 #define alphachar(c) (((c) >= 0x41 && (c) <= 0x5a) \
 159            || ((c) >= 0x61 && (c) <= 0x7a))
 160 #define digitchar(c) ((c) >= 0x30 && (c) <= 0x39)
 161
 162 #define borderchar(c) (alphachar(c) || digitchar(c))
 163 #define middlechar(c) (borderchar(c) || hyphenchar(c))
 164 #define domainchar(c) ((c) > 0x20 && (c) < 0x7f)
 165
 166 int
 167 res_hnok(
 168     const char *dn
 169     )
 170 {
 171     int ppch = '\0', pch = PERIOD, ch = *dn++;
 172
 173     while (ch != '\0') {
 174         int nch = *dn++;
 175
 176         if (periodchar(ch)) {
 177             (void)NULL;
 178         } else if (periodchar(pch)) {
 179             if (!borderchar(ch))
 180                 return (0);
 181         } else if (periodchar(nch) || nch == '\0') {
 182             if (!borderchar(ch))
 183                 return (0);
 184         } else {
 185             if (!middlechar(ch))
 186                 return (0);
 187         }
 188         ppch = pch, pch = ch, ch = nch;
 189     }
 190     return (1);
 191 }
 192
 193 /*
 194  * hostname-like (A, MX, WKS) owners can have "*" as their first label
 195  * but must otherwise be as a host name.
 196  */
 197 int
 198 res_ownok(
 199     const char *dn
 200     )
 201 {
 202     if (asterchar(dn[0])) {
 203         if (periodchar(dn[1]))
 204             return (res_hnok(dn+2));
 205         if (dn[1] == '\0')
 206             return (1);
 207     }
 208     return (res_hnok(dn));
 209 }
 210
 211 /*
 212  * SOA RNAMEs and RP RNAMEs can have any printable character in their first
 213  * label, but the rest of the name has to look like a host name.
 214  */
 215 int
 216 res_mailok(
 217     const char *dn
 218     )
 219 {
 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 RFC 1034's character sets are only
 244  * recommendations.
 245  */
 246 int
 247 res_dnok(
 248     const char *dn
 249     )
 250 {
 251     int ch;
 252
 253     while ((ch = *dn++) != '\0')
 254         if (!domainchar(ch))
 255             return (0);
 256     return (1);
 257 }
 258
 259 #ifdef BIND_4_COMPAT
 260 /*
 261  * This module must export the following externally-visible symbols:
 262  *    ___putlong
 263  *    ___putshort
 264  *    __getlong
 265  *    __getshort
 266  * Note that one _ comes from C and the others come from us.
 267  */
 268 void __putlong(u_int32_t src, u_char *dst) { ns_put32(src, dst); }
 269 void __putshort(u_int16_t src, u_char *dst) { ns_put16(src, dst); }
 270 u_int32_t _getlong(const u_char *src) { return (ns_get32(src)); }
 271 u_int16_t _getshort(const u_char *src) { return (ns_get16(src)); }
 272 #endif /*BIND_4_COMPAT*/