1/* $NetBSD: res_comp.c,v 1.6 2004/05/22 23:47:09 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 75static const char sccsid[] = "@(#)res_comp.c 8.1 (Berkeley) 6/4/93"; 76static const char rcsid[] = "Id: res_comp.c,v 1.1.2.1.4.1 2004/03/09 08:33:54 marka Exp"; 77#else 78__RCSID("$NetBSD: res_comp.c,v 1.6 2004/05/22 23:47:09 christos Exp $"); 79#endif 80#endif /* LIBC_SCCS and not lint */ 81 82#include <sys/types.h> 83#include <sys/param.h> 84#include <netinet/in.h> 85#include <arpa/nameser.h> 86#include <ctype.h> 87#ifdef ANDROID_CHANGES 88#include "resolv_private.h" 89#else 90#include <resolv.h> 91#endif 92#include <stdio.h> 93#include <string.h> 94#include <unistd.h> 95 96/* 97 * Expand compressed domain name 'src' to full domain name. 98 * 'msg' is a pointer to the begining of the message, 99 * 'eom' points to the first location after the message, 100 * 'dst' is a pointer to a buffer of size 'dstsiz' for the result. 101 * Return size of compressed name or -1 if there was an error. 102 */ 103int 104dn_expand(const u_char *msg, const u_char *eom, const u_char *src, 105 char *dst, int dstsiz) 106{ 107 int n = ns_name_uncompress(msg, eom, src, dst, (size_t)dstsiz); 108 109 if (n > 0 && dst[0] == '.') 110 dst[0] = '\0'; 111 return (n); 112} 113 114/* 115 * Pack domain name 'exp_dn' in presentation form into 'comp_dn'. 116 * Return the size of the compressed name or -1. 117 * 'length' is the size of the array pointed to by 'comp_dn'. 118 */ 119int 120dn_comp(const char *src, u_char *dst, int dstsiz, 121 u_char **dnptrs, u_char **lastdnptr) 122{ 123 return (ns_name_compress(src, dst, (size_t)dstsiz, 124 (const u_char **)dnptrs, 125 (const u_char **)lastdnptr)); 126} 127 128/* 129 * Skip over a compressed domain name. Return the size or -1. 130 */ 131int 132dn_skipname(const u_char *ptr, const u_char *eom) { 133 const u_char *saveptr = ptr; 134 135 if (ns_name_skip(&ptr, eom) == -1) 136 return (-1); 137 return (ptr - saveptr); 138} 139 140/* 141 * Verify that a domain name uses an acceptable character set. 142 */ 143 144/* 145 * Note the conspicuous absence of ctype macros in these definitions. On 146 * non-ASCII hosts, we can't depend on string literals or ctype macros to 147 * tell us anything about network-format data. The rest of the BIND system 148 * is not careful about this, but for some reason, we're doing it right here. 149 */ 150 151/* BIONIC: We also accept underscores in the middle of labels. 152 * This extension is needed to make resolution on some VPN networks 153 * work properly. 154 */ 155 156#define PERIOD 0x2e 157#define hyphenchar(c) ((c) == 0x2d) 158#define bslashchar(c) ((c) == 0x5c) 159#define periodchar(c) ((c) == PERIOD) 160#define asterchar(c) ((c) == 0x2a) 161#define alphachar(c) (((c) >= 0x41 && (c) <= 0x5a) \ 162 || ((c) >= 0x61 && (c) <= 0x7a)) 163#define digitchar(c) ((c) >= 0x30 && (c) <= 0x39) 164#define underscorechar(c) ((c) == 0x5f) 165 166#define borderchar(c) (alphachar(c) || digitchar(c)) 167#define middlechar(c) (borderchar(c) || hyphenchar(c) || underscorechar(c)) 168#define domainchar(c) ((c) > 0x20 && (c) < 0x7f) 169 170int 171res_hnok(const char *dn) { 172 int pch = PERIOD, ch = *dn++; 173 174 while (ch != '\0') { 175 int nch = *dn++; 176 177 if (periodchar(ch)) { 178 ; 179 } else if (periodchar(pch)) { 180 if (!borderchar(ch)) 181 return (0); 182 } else if (periodchar(nch) || nch == '\0') { 183 if (!borderchar(ch)) 184 return (0); 185 } else { 186 if (!middlechar(ch)) 187 return (0); 188 } 189 pch = ch, ch = nch; 190 } 191 return (1); 192} 193 194/* 195 * hostname-like (A, MX, WKS) owners can have "*" as their first label 196 * but must otherwise be as a host name. 197 */ 198int 199res_ownok(const char *dn) { 200 if (asterchar(dn[0])) { 201 if (periodchar(dn[1])) 202 return (res_hnok(dn+2)); 203 if (dn[1] == '\0') 204 return (1); 205 } 206 return (res_hnok(dn)); 207} 208 209/* 210 * SOA RNAMEs and RP RNAMEs can have any printable character in their first 211 * label, but the rest of the name has to look like a host name. 212 */ 213int 214res_mailok(const char *dn) { 215 int ch, escaped = 0; 216 217 /* "." is a valid missing representation */ 218 if (*dn == '\0') 219 return (1); 220 221 /* otherwise <label>.<hostname> */ 222 while ((ch = *dn++) != '\0') { 223 if (!domainchar(ch)) 224 return (0); 225 if (!escaped && periodchar(ch)) 226 break; 227 if (escaped) 228 escaped = 0; 229 else if (bslashchar(ch)) 230 escaped = 1; 231 } 232 if (periodchar(ch)) 233 return (res_hnok(dn)); 234 return (0); 235} 236 237/* 238 * This function is quite liberal, since RFC 1034's character sets are only 239 * recommendations. 240 */ 241int 242res_dnok(const char *dn) { 243 int ch; 244 245 while ((ch = *dn++) != '\0') 246 if (!domainchar(ch)) 247 return (0); 248 return (1); 249} 250 251#ifdef BIND_4_COMPAT 252/* 253 * This module must export the following externally-visible symbols: 254 * ___putlong 255 * ___putshort 256 * __getlong 257 * __getshort 258 * Note that one _ comes from C and the others come from us. 259 */ 260void __putlong(u_int32_t src, u_char *dst) { ns_put32(src, dst); } 261void __putshort(u_int16_t src, u_char *dst) { ns_put16(src, dst); } 262#ifndef __ultrix__ 263u_int32_t _getlong(const u_char *src) { return (ns_get32(src)); } 264u_int16_t _getshort(const u_char *src) { return (ns_get16(src)); } 265#endif /*__ultrix__*/ 266#endif /*BIND_4_COMPAT*/ 267