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