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 $"; 72 #endif /* LIBC_SCCS and not lint */ 73 #include <sys/cdefs.h> 74 __FBSDID("$FreeBSD$"); 75 76 #include "port_before.h" 77 #include <sys/param.h> 78 #include <netinet/in.h> 79 #include <arpa/nameser.h> 80 #include <ctype.h> 81 #include <resolv.h> 82 #include <stdio.h> 83 #include <string.h> 84 #include <unistd.h> 85 #include "port_after.h" 86 87 /*% 88 * Expand compressed domain name 'src' to full domain name. 89 * 90 * \li 'msg' is a pointer to the beginning of the message, 91 * \li 'eom' points to the first location after the message, 92 * \li 'dst' is a pointer to a buffer of size 'dstsiz' for the result. 93 * \li Return size of compressed name or -1 if there was an error. 94 */ 95 int 96 dn_expand(const u_char *msg, const u_char *eom, const u_char *src, 97 char *dst, int dstsiz) 98 { 99 int n = ns_name_uncompress(msg, eom, src, dst, (size_t)dstsiz); 100 101 if (n > 0 && dst[0] == '.') 102 dst[0] = '\0'; 103 return (n); 104 } 105 106 /*% 107 * Pack domain name 'exp_dn' in presentation form into 'comp_dn'. 108 * 109 * \li Return the size of the compressed name or -1. 110 * \li 'length' is the size of the array pointed to by 'comp_dn'. 111 */ 112 int 113 dn_comp(const char *src, u_char *dst, int dstsiz, 114 u_char **dnptrs, u_char **lastdnptr) 115 { 116 return (ns_name_compress(src, dst, (size_t)dstsiz, 117 (const u_char **)dnptrs, 118 (const u_char **)lastdnptr)); 119 } 120 121 /*% 122 * Skip over a compressed domain name. Return the size or -1. 123 */ 124 int 125 dn_skipname(const u_char *ptr, const u_char *eom) { 126 const u_char *saveptr = ptr; 127 128 if (ns_name_skip(&ptr, eom) == -1) 129 return (-1); 130 return (ptr - saveptr); 131 } 132 133 /*% 134 * Verify that a domain name uses an acceptable character set. 135 * 136 * Note the conspicuous absence of ctype macros in these definitions. On 137 * non-ASCII hosts, we can't depend on string literals or ctype macros to 138 * tell us anything about network-format data. The rest of the BIND system 139 * is not careful about this, but for some reason, we're doing it right here. 140 */ 141 #define PERIOD 0x2e 142 #define hyphenchar(c) ((c) == 0x2d) 143 #define bslashchar(c) ((c) == 0x5c) 144 #define underscorechar(c) ((c) == 0x5f) 145 #define periodchar(c) ((c) == PERIOD) 146 #define asterchar(c) ((c) == 0x2a) 147 #define alphachar(c) (((c) >= 0x41 && (c) <= 0x5a) \ 148 || ((c) >= 0x61 && (c) <= 0x7a)) 149 #define digitchar(c) ((c) >= 0x30 && (c) <= 0x39) 150 151 #ifdef RES_ENFORCE_RFC1034 152 #define borderchar(c) (alphachar(c) || digitchar(c)) 153 #else 154 #define borderchar(c) (alphachar(c) || digitchar(c) || underscorechar(c)) 155 #endif 156 #define middlechar(c) (borderchar(c) || hyphenchar(c)) 157 #define domainchar(c) ((c) > 0x20 && (c) < 0x7f) 158 159 int 160 res_hnok(const char *dn) { 161 int pch = PERIOD, ch = *dn++; 162 163 while (ch != '\0') { 164 int nch = *dn++; 165 166 if (periodchar(ch)) { 167 (void)NULL; 168 } else if (periodchar(pch)) { 169 if (!borderchar(ch)) 170 return (0); 171 } else if (periodchar(nch) || nch == '\0') { 172 if (!borderchar(ch)) 173 return (0); 174 } else { 175 if (!middlechar(ch)) 176 return (0); 177 } 178 pch = ch, ch = nch; 179 } 180 return (1); 181 } 182 183 /*% 184 * hostname-like (A, MX, WKS) owners can have "*" as their first label 185 * but must otherwise be as a host name. 186 */ 187 int 188 res_ownok(const char *dn) { 189 if (asterchar(dn[0])) { 190 if (periodchar(dn[1])) 191 return (res_hnok(dn+2)); 192 if (dn[1] == '\0') 193 return (1); 194 } 195 return (res_hnok(dn)); 196 } 197 198 /*% 199 * SOA RNAMEs and RP RNAMEs can have any printable character in their first 200 * label, but the rest of the name has to look like a host name. 201 */ 202 int 203 res_mailok(const char *dn) { 204 int ch, escaped = 0; 205 206 /* "." is a valid missing representation */ 207 if (*dn == '\0') 208 return (1); 209 210 /* otherwise <label>.<hostname> */ 211 while ((ch = *dn++) != '\0') { 212 if (!domainchar(ch)) 213 return (0); 214 if (!escaped && periodchar(ch)) 215 break; 216 if (escaped) 217 escaped = 0; 218 else if (bslashchar(ch)) 219 escaped = 1; 220 } 221 if (periodchar(ch)) 222 return (res_hnok(dn)); 223 return (0); 224 } 225 226 /*% 227 * This function is quite liberal, since RFC1034's character sets are only 228 * recommendations. 229 */ 230 int 231 res_dnok(const char *dn) { 232 int ch; 233 234 while ((ch = *dn++) != '\0') 235 if (!domainchar(ch)) 236 return (0); 237 return (1); 238 } 239 240 #ifdef BIND_4_COMPAT 241 /*% 242 * This module must export the following externally-visible symbols: 243 * ___putlong 244 * ___putshort 245 * __getlong 246 * __getshort 247 * Note that one _ comes from C and the others come from us. 248 */ 249 250 #ifdef SOLARIS2 251 #ifdef __putlong 252 #undef __putlong 253 #endif 254 #ifdef __putshort 255 #undef __putshort 256 #endif 257 #pragma weak putlong = __putlong 258 #pragma weak putshort = __putshort 259 #endif /* SOLARIS2 */ 260 261 void __putlong(u_int32_t src, u_char *dst) { ns_put32(src, dst); } 262 void __putshort(u_int16_t src, u_char *dst) { ns_put16(src, dst); } 263 #ifndef __ultrix__ 264 u_int32_t _getlong(const u_char *src) { return (ns_get32(src)); } 265 u_int16_t _getshort(const u_char *src) { return (ns_get16(src)); } 266 #endif /*__ultrix__*/ 267 #endif /*BIND_4_COMPAT*/ 268 269 /* 270 * Weak aliases for applications that use certain private entry points, 271 * and fail to include <resolv.h>. 272 */ 273 #undef dn_comp 274 __weak_reference(__dn_comp, dn_comp); 275 #undef dn_expand 276 __weak_reference(__dn_expand, dn_expand); 277 278 /*! \file */ 279