1 /* $NetBSD: res_comp.c,v 1.14 2022/01/24 09:14:36 andvar Exp $ */ 2 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 #include <sys/cdefs.h> 69 #if defined(LIBC_SCCS) && !defined(lint) 70 #ifdef notdef 71 static const char sccsid[] = "@(#)res_comp.c 8.1 (Berkeley) 6/4/93"; 72 static const char rcsid[] = "Id: res_comp.c,v 1.5 2005/07/28 06:51:50 marka Exp"; 73 #else 74 __RCSID("$NetBSD: res_comp.c,v 1.14 2022/01/24 09:14:36 andvar Exp $"); 75 #endif 76 #endif /* LIBC_SCCS and not lint */ 77 78 #include "port_before.h" 79 80 #include "namespace.h" 81 #include <sys/types.h> 82 #include <sys/param.h> 83 #include <netinet/in.h> 84 #include <arpa/nameser.h> 85 #include <assert.h> 86 #include <ctype.h> 87 #include <resolv.h> 88 #include <stdio.h> 89 #include <string.h> 90 #include <unistd.h> 91 #include "port_after.h" 92 93 #ifdef __weak_alias 94 __weak_alias(dn_expand,_dn_expand) 95 __weak_alias(dn_comp,__dn_comp) 96 #if 0 97 __weak_alias(dn_skipname,__dn_skipname) 98 __weak_alias(res_hnok,__res_hnok) 99 __weak_alias(res_ownok,__res_ownok) 100 __weak_alias(res_mailok,__res_mailok) 101 __weak_alias(res_dnok,__res_dnok) 102 #endif 103 #endif 104 105 /*% 106 * Expand compressed domain name 'src' to full domain name. 107 * 108 * \li 'msg' is a pointer to the beginning of the message, 109 * \li 'eom' points to the first location after the message, 110 * \li 'dst' is a pointer to a buffer of size 'dstsiz' for the result. 111 * \li Return size of compressed name or -1 if there was an error. 112 */ 113 int 114 dn_expand(const u_char *msg, const u_char *eom, const u_char *src, 115 char *dst, int dstsiz) 116 { 117 int n = ns_name_uncompress(msg, eom, src, dst, (size_t)dstsiz); 118 119 if (n > 0 && dst[0] == '.') 120 dst[0] = '\0'; 121 return (n); 122 } 123 124 /*% 125 * Pack domain name 'exp_dn' in presentation form into 'comp_dn'. 126 * 127 * \li Return the size of the compressed name or -1. 128 * \li 'length' is the size of the array pointed to by 'comp_dn'. 129 */ 130 int 131 dn_comp(const char *src, u_char *dst, int dstsiz, 132 u_char **dnptrs, u_char **lastdnptr) 133 { 134 return (ns_name_compress(src, dst, (size_t)dstsiz, 135 (void *)dnptrs, 136 (void *)lastdnptr)); 137 } 138 139 /*% 140 * Skip over a compressed domain name. Return the size or -1. 141 */ 142 int 143 dn_skipname(const u_char *ptr, const u_char *eom) { 144 const u_char *saveptr = ptr; 145 146 if (ns_name_skip(&ptr, eom) == -1) 147 return (-1); 148 _DIAGASSERT(__type_fit(int, ptr - saveptr)); 149 return (int)(ptr - saveptr); 150 } 151 152 /*% 153 * Verify that a domain name uses an acceptable character set. 154 * 155 * Note the conspicuous absence of ctype macros in these definitions. On 156 * non-ASCII hosts, we can't depend on string literals or ctype macros to 157 * tell us anything about network-format data. The rest of the BIND system 158 * is not careful about this, but for some reason, we're doing it right here. 159 */ 160 #define PERIOD 0x2e 161 #define hyphenchar(c) ((c) == 0x2d) 162 #define bslashchar(c) ((c) == 0x5c) 163 #define periodchar(c) ((c) == PERIOD) 164 #define asterchar(c) ((c) == 0x2a) 165 #define alphachar(c) (((c) >= 0x41 && (c) <= 0x5a) \ 166 || ((c) >= 0x61 && (c) <= 0x7a)) 167 #define digitchar(c) ((c) >= 0x30 && (c) <= 0x39) 168 169 #define borderchar(c) (alphachar(c) || digitchar(c)) 170 #define middlechar(c) (borderchar(c) || hyphenchar(c)) 171 #define domainchar(c) ((c) > 0x20 && (c) < 0x7f) 172 173 int 174 res_hnok(const char *dn) { 175 int pch = PERIOD, ch = *dn++; 176 177 while (ch != '\0') { 178 int nch = *dn++; 179 180 if (periodchar(ch)) { 181 ; 182 } else if (periodchar(pch)) { 183 if (!borderchar(ch)) 184 return (0); 185 } else if (periodchar(nch) || nch == '\0') { 186 if (!borderchar(ch)) 187 return (0); 188 } else { 189 if (!middlechar(ch)) 190 return (0); 191 } 192 pch = ch, ch = nch; 193 } 194 return (1); 195 } 196 197 /*% 198 * hostname-like (A, MX, WKS) owners can have "*" as their first label 199 * but must otherwise be as a host name. 200 */ 201 int 202 res_ownok(const char *dn) { 203 if (asterchar(dn[0])) { 204 if (periodchar(dn[1])) 205 return (res_hnok(dn+2)); 206 if (dn[1] == '\0') 207 return (1); 208 } 209 return (res_hnok(dn)); 210 } 211 212 /*% 213 * SOA RNAMEs and RP RNAMEs can have any printable character in their first 214 * label, but the rest of the name has to look like a host name. 215 */ 216 int 217 res_mailok(const char *dn) { 218 int ch, escaped = 0; 219 220 /* "." is a valid missing representation */ 221 if (*dn == '\0') 222 return (1); 223 224 /* otherwise <label>.<hostname> */ 225 while ((ch = *dn++) != '\0') { 226 if (!domainchar(ch)) 227 return (0); 228 if (!escaped && periodchar(ch)) 229 break; 230 if (escaped) 231 escaped = 0; 232 else if (bslashchar(ch)) 233 escaped = 1; 234 } 235 if (periodchar(ch)) 236 return (res_hnok(dn)); 237 return (0); 238 } 239 240 /*% 241 * This function is quite liberal, since RFC1034's character sets are only 242 * recommendations. 243 */ 244 int 245 res_dnok(const char *dn) { 246 int ch; 247 248 while ((ch = *dn++) != '\0') 249 if (!domainchar(ch)) 250 return (0); 251 return (1); 252 } 253 254 #ifdef BIND_4_COMPAT 255 /*% 256 * This module must export the following externally-visible symbols: 257 * ___putlong 258 * ___putshort 259 * __getlong 260 * __getshort 261 * Note that one _ comes from C and the others come from us. 262 */ 263 264 #ifdef SOLARIS2 265 #ifdef __putlong 266 #undef __putlong 267 #endif 268 #ifdef __putshort 269 #undef __putshort 270 #endif 271 #pragma weak putlong = __putlong 272 #pragma weak putshort = __putshort 273 #endif /* SOLARIS2 */ 274 275 void __putlong(u_int32_t src, u_char *dst) { ns_put32(src, dst); } 276 void __putshort(u_int16_t src, u_char *dst) { ns_put16(src, dst); } 277 #ifndef __ultrix__ 278 u_int32_t _getlong(const u_char *src) { return (ns_get32(src)); } 279 u_int16_t _getshort(const u_char *src) { return (ns_get16(src)); } 280 #endif /*__ultrix__*/ 281 #endif /*BIND_4_COMPAT*/ 282 283 /*! \file */ 284
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