1 /*- 2 * SPDX-License-Identifier: (BSD-3-Clause AND ISC) 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. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 /* 33 * Portions Copyright (c) 1993 by Digital Equipment Corporation. 34 * 35 * Permission to use, copy, modify, and distribute this software for any 36 * purpose with or without fee is hereby granted, provided that the above 37 * copyright notice and this permission notice appear in all copies, and that 38 * the name of Digital Equipment Corporation not be used in advertising or 39 * publicity pertaining to distribution of the document or software without 40 * specific, written prior permission. 41 * 42 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL 43 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES 44 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT 45 * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL 46 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR 47 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS 48 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS 49 * SOFTWARE. 50 */ 51 52 /* 53 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC") 54 * Portions Copyright (c) 1996-1999 by Internet Software Consortium. 55 * 56 * Permission to use, copy, modify, and distribute this software for any 57 * purpose with or without fee is hereby granted, provided that the above 58 * copyright notice and this permission notice appear in all copies. 59 * 60 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES 61 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 62 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR 63 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 64 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 65 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT 66 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 67 */ 68 69 #if defined(LIBC_SCCS) && !defined(lint) 70 static const char sccsid[] = "@(#)res_comp.c 8.1 (Berkeley) 6/4/93"; 71 static const char rcsid[] = "$Id: res_comp.c,v 1.5 2005/07/28 06:51:50 marka Exp $"; 72 #endif /* LIBC_SCCS and not lint */ 73 #include "port_before.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 beginning 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 bslashchar(c) ((c) == 0x5c) 141 #define underscorechar(c) ((c) == 0x5f) 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 #ifdef RES_ENFORCE_RFC1034 149 #define borderchar(c) (alphachar(c) || digitchar(c)) 150 #else 151 #define borderchar(c) (alphachar(c) || digitchar(c) || underscorechar(c)) 152 #endif 153 #define middlechar(c) (borderchar(c) || hyphenchar(c)) 154 #define domainchar(c) ((c) > 0x20 && (c) < 0x7f) 155 156 int 157 res_hnok(const char *dn) { 158 int pch = PERIOD, ch = *dn++; 159 160 while (ch != '\0') { 161 int nch = *dn++; 162 163 if (periodchar(ch)) { 164 (void)NULL; 165 } else if (periodchar(pch)) { 166 if (!borderchar(ch)) 167 return (0); 168 } else if (periodchar(nch) || nch == '\0') { 169 if (!borderchar(ch)) 170 return (0); 171 } else { 172 if (!middlechar(ch)) 173 return (0); 174 } 175 pch = ch, ch = nch; 176 } 177 return (1); 178 } 179 180 /*% 181 * hostname-like (A, MX, WKS) owners can have "*" as their first label 182 * but must otherwise be as a host name. 183 */ 184 int 185 res_ownok(const char *dn) { 186 if (asterchar(dn[0])) { 187 if (periodchar(dn[1])) 188 return (res_hnok(dn+2)); 189 if (dn[1] == '\0') 190 return (1); 191 } 192 return (res_hnok(dn)); 193 } 194 195 /*% 196 * SOA RNAMEs and RP RNAMEs can have any printable character in their first 197 * label, but the rest of the name has to look like a host name. 198 */ 199 int 200 res_mailok(const char *dn) { 201 int ch, escaped = 0; 202 203 /* "." is a valid missing representation */ 204 if (*dn == '\0') 205 return (1); 206 207 /* otherwise <label>.<hostname> */ 208 while ((ch = *dn++) != '\0') { 209 if (!domainchar(ch)) 210 return (0); 211 if (!escaped && periodchar(ch)) 212 break; 213 if (escaped) 214 escaped = 0; 215 else if (bslashchar(ch)) 216 escaped = 1; 217 } 218 if (periodchar(ch)) 219 return (res_hnok(dn)); 220 return (0); 221 } 222 223 /*% 224 * This function is quite liberal, since RFC1034's character sets are only 225 * recommendations. 226 */ 227 int 228 res_dnok(const char *dn) { 229 int ch; 230 231 while ((ch = *dn++) != '\0') 232 if (!domainchar(ch)) 233 return (0); 234 return (1); 235 } 236 237 #ifdef BIND_4_COMPAT 238 /*% 239 * This module must export the following externally-visible symbols: 240 * ___putlong 241 * ___putshort 242 * __getlong 243 * __getshort 244 * Note that one _ comes from C and the others come from us. 245 */ 246 247 #ifdef SOLARIS2 248 #ifdef __putlong 249 #undef __putlong 250 #endif 251 #ifdef __putshort 252 #undef __putshort 253 #endif 254 #pragma weak putlong = __putlong 255 #pragma weak putshort = __putshort 256 #endif /* SOLARIS2 */ 257 258 void __putlong(u_int32_t src, u_char *dst) { ns_put32(src, dst); } 259 void __putshort(u_int16_t src, u_char *dst) { ns_put16(src, dst); } 260 #ifndef __ultrix__ 261 u_int32_t _getlong(const u_char *src) { return (ns_get32(src)); } 262 u_int16_t _getshort(const u_char *src) { return (ns_get16(src)); } 263 #endif /*__ultrix__*/ 264 #endif /*BIND_4_COMPAT*/ 265 266 /* 267 * Weak aliases for applications that use certain private entry points, 268 * and fail to include <resolv.h>. 269 */ 270 #undef dn_comp 271 __weak_reference(__dn_comp, dn_comp); 272 #undef dn_expand 273 __weak_reference(__dn_expand, dn_expand); 274 275 /*! \file */ 276