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:  * 4. 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) 1996-1999 by Internet Software Consortium.
   52:  *
   53:  * Permission to use, copy, modify, and distribute this software for any
   54:  * purpose with or without fee is hereby granted, provided that the above
   55:  * copyright notice and this permission notice appear in all copies.
   56:  *
   57:  * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
   58:  * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
   59:  * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
   60:  * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
   61:  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
   62:  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
   63:  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
   64:  * SOFTWARE.
   65:  */
   66: 
   67: #if defined(LIBC_SCCS) && !defined(lint)
   68: static const char sccsid[] = "@(#)res_comp.c    8.1 (Berkeley) 6/4/93";
   69: static const char rcsid[] = "$BINDId: res_comp.c,v 8.15 1999/10/13 16:39:39 vixie Exp $";
   70: #endif /* LIBC_SCCS and not lint */
   71: 
   72: #include <sys/types.h>
   73: #include <sys/param.h>
   74: #include <netinet/in.h>
   75: #include <arpa/nameser.h>
   76: #include <ctype.h>
   77: #include <resolv.h>
   78: #include <stdio.h>
   79: #include <string.h>
   80: #include <unistd.h>
   81: 
   82: /*
   83:  * Expand compressed domain name 'comp_dn' to full domain name.
   84:  * 'msg' is a pointer to the begining of the message,
   85:  * 'eomorig' points to the first location after the message,
   86:  * 'exp_dn' is a pointer to a buffer of size 'length' for the result.
   87:  * Return size of compressed name or -1 if there was an error.
   88:  */
   89: int
   90: dn_expand(const u_char *msg, const u_char *eom, const u_char *src,
   91:           char *dst, int dstsiz)
   92: {
   93:         int n = ns_name_uncompress(msg, eom, src, dst, (size_t)dstsiz);
   94: 
   95:         if (n > 0 && dst[0] == '.')
   96:                 dst[0] = '\0';
   97:         return (n);
   98: }
   99: libresolv_hidden_def (dn_expand)
  100: 
  101: /*
  102:  * Pack domain name 'exp_dn' in presentation form into 'comp_dn'.
  103:  * Return the size of the compressed name or -1.
  104:  * 'length' is the size of the array pointed to by 'comp_dn'.
  105:  */
  106: int
  107: dn_comp(const char *src, u_char *dst, int dstsiz,
  108:         u_char **dnptrs, u_char **lastdnptr)
  109: {
  110:         return (ns_name_compress(src, dst, (size_t)dstsiz,
  111:                                  (const u_char **)dnptrs,
  112:                                  (const u_char **)lastdnptr));
  113: }
  114: libresolv_hidden_def (dn_comp)
  115: 
  116: /*
  117:  * Skip over a compressed domain name. Return the size or -1.
  118:  */
  119: int
  120: dn_skipname(const u_char *ptr, const u_char *eom) {
  121:         const u_char *saveptr = ptr;
  122: 
  123:         if (ns_name_skip(&ptr, eom) == -1)
  124:                 return (-1);
  125:         return (ptr - saveptr);
  126: }
  127: libresolv_hidden_def (dn_skipname)
  128: 
  129: /*
  130:  * Verify that a domain name uses an acceptable character set.
  131:  */
  132: 
  133: /*
  134:  * Note the conspicuous absence of ctype macros in these definitions.  On
  135:  * non-ASCII hosts, we can't depend on string literals or ctype macros to
  136:  * tell us anything about network-format data.  The rest of the BIND system
  137:  * is not careful about this, but for some reason, we're doing it right here.
  138:  */
  139: #define PERIOD 0x2e
  140: #define hyphenchar(c) ((c) == 0x2d)
  141: #define underscorechar(c) ((c) == 0x5f)
  142: #define bslashchar(c) ((c) == 0x5c)
  143: #define periodchar(c) ((c) == PERIOD)
  144: #define asterchar(c) ((c) == 0x2a)
  145: #define alphachar(c) (((c) >= 0x41 && (c) <= 0x5a) \
  146:                    || ((c) >= 0x61 && (c) <= 0x7a))
  147: #define digitchar(c) ((c) >= 0x30 && (c) <= 0x39)
  148: 
  149: #define borderchar(c) (alphachar(c) || digitchar(c))
  150: #define middlechar(c) (borderchar(c) || hyphenchar(c) || underscorechar(c))
  151: #define domainchar(c) ((c) > 0x20 && (c) < 0x7f)
  152: 
  153: int
  154: res_hnok(const char *dn) {
  155:         int ppch = '\0', pch = PERIOD, ch = *dn++;
  156: 
  157:         while (ch != '\0') {
  158:                 int nch = *dn++;
  159: 
  160:                 if (periodchar(ch)) {
  161:                         (void)NULL;
  162:                 } else if (periodchar(pch)) {
  163:                         if (!borderchar(ch))
  164:                                 return (0);
  165:                 } else if (periodchar(nch) || nch == '\0') {
  166:                         if (!borderchar(ch))
  167:                                 return (0);
  168:                 } else {
  169:                         if (!middlechar(ch))
  170:                                 return (0);
  171:                 }
  172:                 ppch = pch, pch = ch, ch = nch;
  173:         }
  174:         return (1);
  175: }
  176: libresolv_hidden_def (res_hnok)
  177: 
  178: /*
  179:  * hostname-like (A, MX, WKS) owners can have "*" as their first label
  180:  * but must otherwise be as a host name.
  181:  */
  182: int
  183: res_ownok(const char *dn) {
  184:         if (asterchar(dn[0])) {
  185:                 if (periodchar(dn[1]))
  186:                         return (res_hnok(dn+2));
  187:                 if (dn[1] == '\0')
  188:                         return (1);
  189:         }
  190:         return (res_hnok(dn));
  191: }
  192: 
  193: /*
  194:  * SOA RNAMEs and RP RNAMEs can have any printable character in their first
  195:  * label, but the rest of the name has to look like a host name.
  196:  */
  197: int
  198: res_mailok(const char *dn) {
  199:         int ch, escaped = 0;
  200: 
  201:         /* "." is a valid missing representation */
  202:         if (*dn == '\0')
  203:                 return (1);
  204: 
  205:         /* otherwise <label>.<hostname> */
  206:         while ((ch = *dn++) != '\0') {
  207:                 if (!domainchar(ch))
  208:                         return (0);
  209:                 if (!escaped && periodchar(ch))
  210:                         break;
  211:                 if (escaped)
  212:                         escaped = 0;
  213:                 else if (bslashchar(ch))
  214:                         escaped = 1;
  215:         }
  216:         if (periodchar(ch))
  217:                 return (res_hnok(dn));
  218:         return (0);
  219: }
  220: 
  221: /*
  222:  * This function is quite liberal, since RFC 1034's character sets are only
  223:  * recommendations.
  224:  */
  225: int
  226: res_dnok(const char *dn) {
  227:         int ch;
  228: 
  229:         while ((ch = *dn++) != '\0')
  230:                 if (!domainchar(ch))
  231:                         return (0);
  232:         return (1);
  233: }
  234: libresolv_hidden_def (res_dnok)
  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: void __putlong(u_int32_t src, u_char *dst) { ns_put32(src, dst); }
  246: libresolv_hidden_def (__putlong)
  247: void __putshort(u_int16_t src, u_char *dst) { ns_put16(src, dst); }
  248: libresolv_hidden_def (__putshort)
  249: #ifndef __ultrix__
  250: u_int32_t _getlong(const u_char *src) { return (ns_get32(src)); }
  251: u_int16_t _getshort(const u_char *src) { return (ns_get16(src)); }
  252: #endif /*__ultrix__*/
  253: #endif /*BIND_4_COMPAT*/
  254: ^L
  255: 
  256: #include <shlib-compat.h>
  257: 
  258: #if SHLIB_COMPAT(libresolv, GLIBC_2_0, GLIBC_2_2)
  259: # undef dn_expand
  260: weak_alias (__dn_expand, dn_expand);
  261: #endif