res_comp.c revision 165903
1/* 2 * Copyright (c) 1985, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 4. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30/* 31 * Portions Copyright (c) 1993 by Digital Equipment Corporation. 32 * 33 * Permission to use, copy, modify, and distribute this software for any 34 * purpose with or without fee is hereby granted, provided that the above 35 * copyright notice and this permission notice appear in all copies, and that 36 * the name of Digital Equipment Corporation not be used in advertising or 37 * publicity pertaining to distribution of the document or software without 38 * specific, written prior permission. 39 * 40 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL 41 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES 42 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT 43 * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL 44 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR 45 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS 46 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS 47 * SOFTWARE. 48 */ 49 50/* 51 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC") 52 * Portions Copyright (c) 1996-1999 by Internet Software Consortium. 53 * 54 * Permission to use, copy, modify, and distribute this software for any 55 * purpose with or without fee is hereby granted, provided that the above 56 * copyright notice and this permission notice appear in all copies. 57 * 58 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES 59 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 60 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR 61 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 62 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 63 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT 64 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 65 */ 66 67#if defined(LIBC_SCCS) && !defined(lint) 68static const char sccsid[] = "@(#)res_comp.c 8.1 (Berkeley) 6/4/93"; 69static const char rcsid[] = "$Id: res_comp.c,v 1.1.2.1.4.2 2005/07/28 07:43:22 marka Exp $"; 70#endif /* LIBC_SCCS and not lint */ 71#include <sys/cdefs.h> 72__FBSDID("$FreeBSD: head/lib/libc/resolv/res_comp.c 165903 2007-01-09 00:28:16Z imp $"); 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 <ctype.h> 80#include <resolv.h> 81#include <stdio.h> 82#include <string.h> 83#include <unistd.h> 84#include "port_after.h" 85 86/* 87 * Expand compressed domain name 'src' to full domain name. 88 * 'msg' is a pointer to the begining of the message, 89 * 'eom' points to the first location after the message, 90 * 'dst' is a pointer to a buffer of size 'dstsiz' for the result. 91 * Return size of compressed name or -1 if there was an error. 92 */ 93int 94dn_expand(const u_char *msg, const u_char *eom, const u_char *src, 95 char *dst, int dstsiz) 96{ 97 int n = ns_name_uncompress(msg, eom, src, dst, (size_t)dstsiz); 98 99 if (n > 0 && dst[0] == '.') 100 dst[0] = '\0'; 101 return (n); 102} 103 104/* 105 * Pack domain name 'exp_dn' in presentation form into 'comp_dn'. 106 * Return the size of the compressed name or -1. 107 * 'length' is the size of the array pointed to by 'comp_dn'. 108 */ 109int 110dn_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 */ 121int 122dn_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 */ 133 134/* 135 * Note the conspicuous absence of ctype macros in these definitions. On 136 * non-ASCII hosts, we can't depend on string literals or ctype macros to 137 * tell us anything about network-format data. The rest of the BIND system 138 * is not careful about this, but for some reason, we're doing it right here. 139 */ 140#define PERIOD 0x2e 141#define hyphenchar(c) ((c) == 0x2d) 142#define bslashchar(c) ((c) == 0x5c) 143#define periodchar(c) ((c) == PERIOD) 144#define asterchar(c) ((c) == 0x2a) 145#define alphachar(c) (((c) >= 0x41 && (c) <= 0x5a) \ 146 || ((c) >= 0x61 && (c) <= 0x7a)) 147#define digitchar(c) ((c) >= 0x30 && (c) <= 0x39) 148 149#define borderchar(c) (alphachar(c) || digitchar(c)) 150#define middlechar(c) (borderchar(c) || hyphenchar(c)) 151#define domainchar(c) ((c) > 0x20 && (c) < 0x7f) 152 153int 154res_hnok(const char *dn) { 155 int pch = PERIOD, ch = *dn++; 156 157 while (ch != '\0') { 158 int nch = *dn++; 159 160 if (periodchar(ch)) { 161 (void)NULL; 162 } else if (periodchar(pch)) { 163 if (!borderchar(ch)) 164 return (0); 165 } else if (periodchar(nch) || nch == '\0') { 166 if (!borderchar(ch)) 167 return (0); 168 } else { 169 if (!middlechar(ch)) 170 return (0); 171 } 172 pch = ch, ch = nch; 173 } 174 return (1); 175} 176 177/* 178 * hostname-like (A, MX, WKS) owners can have "*" as their first label 179 * but must otherwise be as a host name. 180 */ 181int 182res_ownok(const char *dn) { 183 if (asterchar(dn[0])) { 184 if (periodchar(dn[1])) 185 return (res_hnok(dn+2)); 186 if (dn[1] == '\0') 187 return (1); 188 } 189 return (res_hnok(dn)); 190} 191 192/* 193 * SOA RNAMEs and RP RNAMEs can have any printable character in their first 194 * label, but the rest of the name has to look like a host name. 195 */ 196int 197res_mailok(const char *dn) { 198 int ch, escaped = 0; 199 200 /* "." is a valid missing representation */ 201 if (*dn == '\0') 202 return (1); 203 204 /* otherwise <label>.<hostname> */ 205 while ((ch = *dn++) != '\0') { 206 if (!domainchar(ch)) 207 return (0); 208 if (!escaped && periodchar(ch)) 209 break; 210 if (escaped) 211 escaped = 0; 212 else if (bslashchar(ch)) 213 escaped = 1; 214 } 215 if (periodchar(ch)) 216 return (res_hnok(dn)); 217 return (0); 218} 219 220/* 221 * This function is quite liberal, since RFC 1034's character sets are only 222 * recommendations. 223 */ 224int 225res_dnok(const char *dn) { 226 int ch; 227 228 while ((ch = *dn++) != '\0') 229 if (!domainchar(ch)) 230 return (0); 231 return (1); 232} 233 234#ifdef BIND_4_COMPAT 235/* 236 * This module must export the following externally-visible symbols: 237 * ___putlong 238 * ___putshort 239 * __getlong 240 * __getshort 241 * Note that one _ comes from C and the others come from us. 242 */ 243 244#ifdef SOLARIS2 245#ifdef __putlong 246#undef __putlong 247#endif 248#ifdef __putshort 249#undef __putshort 250#endif 251#pragma weak putlong = __putlong 252#pragma weak putshort = __putshort 253#endif /* SOLARIS2 */ 254 255void __putlong(u_int32_t src, u_char *dst) { ns_put32(src, dst); } 256void __putshort(u_int16_t src, u_char *dst) { ns_put16(src, dst); } 257#ifndef __ultrix__ 258u_int32_t _getlong(const u_char *src) { return (ns_get32(src)); } 259u_int16_t _getshort(const u_char *src) { return (ns_get16(src)); } 260#endif /*__ultrix__*/ 261#endif /*BIND_4_COMPAT*/ 262 263/* 264 * Weak aliases for applications that use certain private entry points, 265 * and fail to include <resolv.h>. 266 */ 267#undef dn_comp 268__weak_reference(__dn_comp, dn_comp); 269#undef dn_expand 270__weak_reference(__dn_expand, dn_expand); 271