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 73 #include "res_comp.h" 74 75 #include <arpa/nameser.h> 76 #include <netinet/in.h> 77 #include <string.h> 78 #include <unistd.h> 79 80 /* 81 * Expand compressed domain name 'src' to full domain name. 82 * 'msg' is a pointer to the begining of the message, 83 * 'eom' points to the first location after the message, 84 * 'dst' is a pointer to a buffer of size 'dstsiz' for the result. 85 * Return size of compressed name or -1 if there was an error. 86 */ 87 int dn_expand(const uint8_t* msg, const uint8_t* eom, const uint8_t* src, char* dst, int dstsiz) { 88 int n = ns_name_uncompress(msg, eom, src, dst, (size_t) dstsiz); 89 90 if (n > 0 && dst[0] == '.') dst[0] = '\0'; 91 return n; 92 } 93 94 /* 95 * Pack domain name 'exp_dn' in presentation form into 'comp_dn'. 96 * Return the size of the compressed name or -1. 97 * 'length' is the size of the array pointed to by 'comp_dn'. 98 */ 99 int dn_comp(const char* src, uint8_t* dst, int dstsiz, uint8_t** dnptrs, uint8_t** lastdnptr) { 100 return (ns_name_compress(src, dst, (size_t)dstsiz, (const uint8_t**)dnptrs, 101 (const uint8_t**)lastdnptr)); 102 } 103 104 /* 105 * Skip over a compressed domain name. Return the size or -1. 106 */ 107 int dn_skipname(const uint8_t* ptr, const uint8_t* eom) { 108 const uint8_t* saveptr = ptr; 109 110 if (ns_name_skip(&ptr, eom) == -1) return (-1); 111 return (ptr - saveptr); 112 } 113 114 /* 115 * Verify that a domain name uses an acceptable character set. 116 */ 117 118 /* 119 * Note the conspicuous absence of ctype macros in these definitions. On 120 * non-ASCII hosts, we can't depend on string literals or ctype macros to 121 * tell us anything about network-format data. The rest of the BIND system 122 * is not careful about this, but for some reason, we're doing it right here. 123 */ 124 125 /* BIONIC: We also accept underscores in the middle of labels. 126 * This extension is needed to make resolution on some VPN networks 127 * work properly. 128 */ 129 130 #define PERIOD 0x2e 131 #define hyphenchar(c) ((c) == 0x2d) 132 #define bslashchar(c) ((c) == 0x5c) 133 #define periodchar(c) ((c) == PERIOD) 134 #define asterchar(c) ((c) == 0x2a) 135 #define alphachar(c) (((c) >= 0x41 && (c) <= 0x5a) || ((c) >= 0x61 && (c) <= 0x7a)) 136 #define digitchar(c) ((c) >= 0x30 && (c) <= 0x39) 137 #define underscorechar(c) ((c) == 0x5f) 138 139 #define borderchar(c) (alphachar(c) || digitchar(c)) 140 #define middlechar(c) (borderchar(c) || hyphenchar(c) || underscorechar(c)) 141 #define domainchar(c) ((c) > 0x20 && (c) < 0x7f) 142 143 bool res_hnok(const char* dn) { 144 char pch = PERIOD, ch = *dn++; 145 146 while (ch != '\0') { 147 char nch = *dn++; 148 149 if (periodchar(ch)) { 150 ; 151 } else if (periodchar(pch) || periodchar(nch) || nch == '\0') { 152 if (!borderchar(ch)) return false; 153 } else { 154 if (!middlechar(ch)) return false; 155 } 156 pch = ch, ch = nch; 157 } 158 return true; 159 } 160 161 /* 162 * This function is quite liberal, since RFC 1034's character sets are only 163 * recommendations. 164 */ 165 bool res_dnok(const char* dn) { 166 char ch; 167 168 while ((ch = *dn++) != '\0') 169 if (!domainchar(ch)) return false; 170 return true; 171 } 172