1 /* $NetBSD: res_comp.c,v 1.13 2015/02/24 17:56:20 christos 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 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 74 #include "port_before.h" 75 #include <sys/types.h> 76 #include <sys/param.h> 77 #include <netinet/in.h> 78 #include <arpa/nameser.h> 79 #include <assert.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 #ifdef __weak_alias 88 __weak_alias(dn_expand,_dn_expand) 89 __weak_alias(dn_comp,__dn_comp) 90 #if 0 91 __weak_alias(dn_skipname,__dn_skipname) 92 __weak_alias(res_hnok,__res_hnok) 93 __weak_alias(res_ownok,__res_ownok) 94 __weak_alias(res_mailok,__res_mailok) 95 __weak_alias(res_dnok,__res_dnok) 96 #endif 97 #endif 98 99 /*% 100 * Expand compressed domain name 'src' to full domain name. 101 * 102 * \li 'msg' is a pointer to the begining of the message, 103 * \li 'eom' points to the first location after the message, 104 * \li 'dst' is a pointer to a buffer of size 'dstsiz' for the result. 105 * \li Return size of compressed name or -1 if there was an error. 106 */ 107 int 108 dn_expand(const u_char *msg, const u_char *eom, const u_char *src, 109 char *dst, int dstsiz) 110 { 111 int n = ns_name_uncompress(msg, eom, src, dst, (size_t)dstsiz); 112 113 if (n > 0 && dst[0] == '.') 114 dst[0] = '\0'; 115 return (n); 116 } 117 118 /*% 119 * Pack domain name 'exp_dn' in presentation form into 'comp_dn'. 120 * 121 * \li Return the size of the compressed name or -1. 122 * \li 'length' is the size of the array pointed to by 'comp_dn'. 123 */ 124 int 125 dn_comp(const char *src, u_char *dst, int dstsiz, 126 u_char **dnptrs, u_char **lastdnptr) 127 { 128 return (ns_name_compress(src, dst, (size_t)dstsiz, 129 (void *)dnptrs, 130 (void *)lastdnptr)); 131 } 132 133 /*% 134 * Skip over a compressed domain name. Return the size or -1. 135 */ 136 int 137 dn_skipname(const u_char *ptr, const u_char *eom) { 138 const u_char *saveptr = ptr; 139 140 if (ns_name_skip(&ptr, eom) == -1) 141 return (-1); 142 assert(INT_MIN <= (ptr - saveptr) && (ptr - saveptr) <= INT_MAX); 143 return (int)(ptr - saveptr); 144 } 145 146 /*% 147 * Verify that a domain name uses an acceptable character set. 148 * 149 * Note the conspicuous absence of ctype macros in these definitions. On 150 * non-ASCII hosts, we can't depend on string literals or ctype macros to 151 * tell us anything about network-format data. The rest of the BIND system 152 * is not careful about this, but for some reason, we're doing it right here. 153 */ 154 #define PERIOD 0x2e 155 #define hyphenchar(c) ((c) == 0x2d || (c) == 0x5f) 156 #define bslashchar(c) ((c) == 0x5c) 157 #define periodchar(c) ((c) == PERIOD) 158 #define asterchar(c) ((c) == 0x2a) 159 #define alphachar(c) (((c) >= 0x41 && (c) <= 0x5a) \ 160 || ((c) >= 0x61 && (c) <= 0x7a)) 161 #define digitchar(c) ((c) >= 0x30 && (c) <= 0x39) 162 163 #define borderchar(c) (alphachar(c) || digitchar(c)) 164 #define middlechar(c) (borderchar(c) || hyphenchar(c)) 165 #define domainchar(c) ((c) > 0x20 && (c) < 0x7f) 166 167 int 168 res_hnok(const char *dn) { 169 int pch = PERIOD, ch = *dn++; 170 171 while (ch != '\0') { 172 int nch = *dn++; 173 174 if (periodchar(ch)) { 175 ; 176 } else if (periodchar(pch)) { 177 if (!borderchar(ch)) 178 return (0); 179 } else if (periodchar(nch) || nch == '\0') { 180 if (!borderchar(ch)) 181 return (0); 182 } else { 183 if (!middlechar(ch)) 184 return (0); 185 } 186 pch = ch, ch = nch; 187 } 188 return (1); 189 } 190 191 /*% 192 * hostname-like (A, MX, WKS) owners can have "*" as their first label 193 * but must otherwise be as a host name. 194 */ 195 int 196 res_ownok(const char *dn) { 197 if (asterchar(dn[0])) { 198 if (periodchar(dn[1])) 199 return (res_hnok(dn+2)); 200 if (dn[1] == '\0') 201 return (1); 202 } 203 return (res_hnok(dn)); 204 } 205 206 /*% 207 * SOA RNAMEs and RP RNAMEs can have any printable character in their first 208 * label, but the rest of the name has to look like a host name. 209 */ 210 int 211 res_mailok(const char *dn) { 212 int ch, escaped = 0; 213 214 /* "." is a valid missing representation */ 215 if (*dn == '\0') 216 return (1); 217 218 /* otherwise <label>.<hostname> */ 219 while ((ch = *dn++) != '\0') { 220 if (!domainchar(ch)) 221 return (0); 222 if (!escaped && periodchar(ch)) 223 break; 224 if (escaped) 225 escaped = 0; 226 else if (bslashchar(ch)) 227 escaped = 1; 228 } 229 if (periodchar(ch)) 230 return (res_hnok(dn)); 231 return (0); 232 } 233 234 /*% 235 * This function is quite liberal, since RFC1034's character sets are only 236 * recommendations. 237 */ 238 int 239 res_dnok(const char *dn) { 240 int ch; 241 242 while ((ch = *dn++) != '\0') 243 if (!domainchar(ch)) 244 return (0); 245 return (1); 246 } 247 248 #ifdef BIND_4_COMPAT 249 /*% 250 * This module must export the following externally-visible symbols: 251 * ___putlong 252 * ___putshort 253 * __getlong 254 * __getshort 255 * Note that one _ comes from C and the others come from us. 256 */ 257 258 #ifdef SOLARIS2 259 #ifdef __putlong 260 #undef __putlong 261 #endif 262 #ifdef __putshort 263 #undef __putshort 264 #endif 265 #pragma weak putlong = __putlong 266 #pragma weak putshort = __putshort 267 #endif /* SOLARIS2 */ 268 269 void __putlong(u_int32_t src, u_char *dst) { ns_put32(src, dst); } 270 void __putshort(u_int16_t src, u_char *dst) { ns_put16(src, dst); } 271 #endif /*BIND_4_COMPAT*/ 272 273 #ifndef __ultrix__ 274 u_int32_t _getlong(const u_char *src) { return (ns_get32(src)); } 275 u_int16_t _getshort(const u_char *src) { return (ns_get16(src)); } 276 #endif /*__ultrix__*/ 277 278 /*! \file */ 279