1 /* $NetBSD: res_comp.c,v 1.12 2012/03/13 21:13:43 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. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 /* 37 * Portions Copyright (c) 1993 by Digital Equipment Corporation. 38 * 39 * Permission to use, copy, modify, and distribute this software for any 40 * purpose with or without fee is hereby granted, provided that the above 41 * copyright notice and this permission notice appear in all copies, and that 42 * the name of Digital Equipment Corporation not be used in advertising or 43 * publicity pertaining to distribution of the document or software without 44 * specific, written prior permission. 45 * 46 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL 47 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES 48 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT 49 * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL 50 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR 51 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS 52 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS 53 * SOFTWARE. 54 */ 55 56 /* 57 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC") 58 * Portions Copyright (c) 1996-1999 by Internet Software Consortium. 59 * 60 * Permission to use, copy, modify, and distribute this software for any 61 * purpose with or without fee is hereby granted, provided that the above 62 * copyright notice and this permission notice appear in all copies. 63 * 64 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES 65 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 66 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR 67 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 68 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 69 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT 70 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 71 */ 72 #include <sys/cdefs.h> 73 #if defined(LIBC_SCCS) && !defined(lint) 74 #ifdef notdef 75 static const char sccsid[] = "@(#)res_comp.c 8.1 (Berkeley) 6/4/93"; 76 static const char rcsid[] = "Id: res_comp.c,v 1.5 2005/07/28 06:51:50 marka Exp"; 77 #else 78 __RCSID("$NetBSD: res_comp.c,v 1.12 2012/03/13 21:13:43 christos Exp $"); 79 #endif 80 #endif /* LIBC_SCCS and not lint */ 81 82 #include "port_before.h" 83 84 #include "namespace.h" 85 #include <sys/types.h> 86 #include <sys/param.h> 87 #include <netinet/in.h> 88 #include <arpa/nameser.h> 89 #include <assert.h> 90 #include <ctype.h> 91 #include <resolv.h> 92 #include <stdio.h> 93 #include <string.h> 94 #include <unistd.h> 95 #include "port_after.h" 96 97 #ifdef __weak_alias 98 __weak_alias(dn_expand,_dn_expand) 99 __weak_alias(dn_comp,__dn_comp) 100 #if defined(__minix) 101 __weak_alias(dn_skipname,__dn_skipname) 102 __weak_alias(res_hnok,__res_hnok) 103 __weak_alias(res_ownok,__res_ownok) 104 __weak_alias(res_mailok,__res_mailok) 105 __weak_alias(res_dnok,__res_dnok) 106 #endif /* defined(__minix) */ 107 #endif 108 109 /*% 110 * Expand compressed domain name 'src' to full domain name. 111 * 112 * \li 'msg' is a pointer to the begining of the message, 113 * \li 'eom' points to the first location after the message, 114 * \li 'dst' is a pointer to a buffer of size 'dstsiz' for the result. 115 * \li Return size of compressed name or -1 if there was an error. 116 */ 117 int 118 dn_expand(const u_char *msg, const u_char *eom, const u_char *src, 119 char *dst, int dstsiz) 120 { 121 int n = ns_name_uncompress(msg, eom, src, dst, (size_t)dstsiz); 122 123 if (n > 0 && dst[0] == '.') 124 dst[0] = '\0'; 125 return (n); 126 } 127 128 /*% 129 * Pack domain name 'exp_dn' in presentation form into 'comp_dn'. 130 * 131 * \li Return the size of the compressed name or -1. 132 * \li 'length' is the size of the array pointed to by 'comp_dn'. 133 */ 134 int 135 dn_comp(const char *src, u_char *dst, int dstsiz, 136 u_char **dnptrs, u_char **lastdnptr) 137 { 138 return (ns_name_compress(src, dst, (size_t)dstsiz, 139 (void *)dnptrs, 140 (void *)lastdnptr)); 141 } 142 143 /*% 144 * Skip over a compressed domain name. Return the size or -1. 145 */ 146 int 147 dn_skipname(const u_char *ptr, const u_char *eom) { 148 const u_char *saveptr = ptr; 149 150 if (ns_name_skip(&ptr, eom) == -1) 151 return (-1); 152 _DIAGASSERT(__type_fit(int, ptr - saveptr)); 153 return (int)(ptr - saveptr); 154 } 155 156 /*% 157 * Verify that a domain name uses an acceptable character set. 158 * 159 * Note the conspicuous absence of ctype macros in these definitions. On 160 * non-ASCII hosts, we can't depend on string literals or ctype macros to 161 * tell us anything about network-format data. The rest of the BIND system 162 * is not careful about this, but for some reason, we're doing it right here. 163 */ 164 #define PERIOD 0x2e 165 #define hyphenchar(c) ((c) == 0x2d) 166 #define bslashchar(c) ((c) == 0x5c) 167 #define periodchar(c) ((c) == PERIOD) 168 #define asterchar(c) ((c) == 0x2a) 169 #define alphachar(c) (((c) >= 0x41 && (c) <= 0x5a) \ 170 || ((c) >= 0x61 && (c) <= 0x7a)) 171 #define digitchar(c) ((c) >= 0x30 && (c) <= 0x39) 172 173 #define borderchar(c) (alphachar(c) || digitchar(c)) 174 #define middlechar(c) (borderchar(c) || hyphenchar(c)) 175 #define domainchar(c) ((c) > 0x20 && (c) < 0x7f) 176 177 int 178 res_hnok(const char *dn) { 179 int pch = PERIOD, ch = *dn++; 180 181 while (ch != '\0') { 182 int nch = *dn++; 183 184 if (periodchar(ch)) { 185 ; 186 } else if (periodchar(pch)) { 187 if (!borderchar(ch)) 188 return (0); 189 } else if (periodchar(nch) || nch == '\0') { 190 if (!borderchar(ch)) 191 return (0); 192 } else { 193 if (!middlechar(ch)) 194 return (0); 195 } 196 pch = ch, ch = nch; 197 } 198 return (1); 199 } 200 201 /*% 202 * hostname-like (A, MX, WKS) owners can have "*" as their first label 203 * but must otherwise be as a host name. 204 */ 205 int 206 res_ownok(const char *dn) { 207 if (asterchar(dn[0])) { 208 if (periodchar(dn[1])) 209 return (res_hnok(dn+2)); 210 if (dn[1] == '\0') 211 return (1); 212 } 213 return (res_hnok(dn)); 214 } 215 216 /*% 217 * SOA RNAMEs and RP RNAMEs can have any printable character in their first 218 * label, but the rest of the name has to look like a host name. 219 */ 220 int 221 res_mailok(const char *dn) { 222 int ch, escaped = 0; 223 224 /* "." is a valid missing representation */ 225 if (*dn == '\0') 226 return (1); 227 228 /* otherwise <label>.<hostname> */ 229 while ((ch = *dn++) != '\0') { 230 if (!domainchar(ch)) 231 return (0); 232 if (!escaped && periodchar(ch)) 233 break; 234 if (escaped) 235 escaped = 0; 236 else if (bslashchar(ch)) 237 escaped = 1; 238 } 239 if (periodchar(ch)) 240 return (res_hnok(dn)); 241 return (0); 242 } 243 244 /*% 245 * This function is quite liberal, since RFC1034's character sets are only 246 * recommendations. 247 */ 248 int 249 res_dnok(const char *dn) { 250 int ch; 251 252 while ((ch = *dn++) != '\0') 253 if (!domainchar(ch)) 254 return (0); 255 return (1); 256 } 257 258 #ifdef BIND_4_COMPAT 259 /*% 260 * This module must export the following externally-visible symbols: 261 * ___putlong 262 * ___putshort 263 * __getlong 264 * __getshort 265 * Note that one _ comes from C and the others come from us. 266 */ 267 268 #ifdef SOLARIS2 269 #ifdef __putlong 270 #undef __putlong 271 #endif 272 #ifdef __putshort 273 #undef __putshort 274 #endif 275 #pragma weak putlong = __putlong 276 #pragma weak putshort = __putshort 277 #endif /* SOLARIS2 */ 278 279 void __putlong(u_int32_t src, u_char *dst) { ns_put32(src, dst); } 280 void __putshort(u_int16_t src, u_char *dst) { ns_put16(src, dst); } 281 #ifndef __ultrix__ 282 u_int32_t _getlong(const u_char *src) { return (ns_get32(src)); } 283 u_int16_t _getshort(const u_char *src) { return (ns_get16(src)); } 284 #endif /*__ultrix__*/ 285 #endif /*BIND_4_COMPAT*/ 286 287 /*! \file */ 288