Bernie Innocenti | d1cc724 | 2018-09-11 18:41:37 +0900 | [diff] [blame] | 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 | */ |
Bernie Innocenti | d1cc724 | 2018-09-11 18:41:37 +0900 | [diff] [blame] | 72 | |
Bernie Innocenti | d1cc724 | 2018-09-11 18:41:37 +0900 | [diff] [blame] | 73 | #include <arpa/nameser.h> |
| 74 | #include <ctype.h> |
Bernie Innocenti | eb0c81a | 2018-09-11 18:55:58 +0900 | [diff] [blame] | 75 | #include <netinet/in.h> |
| 76 | #include <sys/param.h> |
| 77 | #include <sys/types.h> |
Bernie Innocenti | d1cc724 | 2018-09-11 18:41:37 +0900 | [diff] [blame] | 78 | #include <string.h> |
| 79 | #include <unistd.h> |
| 80 | |
Bernie Innocenti | ac18b12 | 2018-10-01 23:10:18 +0900 | [diff] [blame] | 81 | #include "resolv_private.h" |
| 82 | |
Bernie Innocenti | d1cc724 | 2018-09-11 18:41:37 +0900 | [diff] [blame] | 83 | /* |
| 84 | * Expand compressed domain name 'src' to full domain name. |
| 85 | * 'msg' is a pointer to the begining of the message, |
| 86 | * 'eom' points to the first location after the message, |
| 87 | * 'dst' is a pointer to a buffer of size 'dstsiz' for the result. |
| 88 | * Return size of compressed name or -1 if there was an error. |
| 89 | */ |
Bernie Innocenti | eb0c81a | 2018-09-11 18:55:58 +0900 | [diff] [blame] | 90 | int dn_expand(const u_char* msg, const u_char* eom, const u_char* src, char* dst, int dstsiz) { |
| 91 | int n = ns_name_uncompress(msg, eom, src, dst, (size_t) dstsiz); |
Bernie Innocenti | d1cc724 | 2018-09-11 18:41:37 +0900 | [diff] [blame] | 92 | |
Bernie Innocenti | eb0c81a | 2018-09-11 18:55:58 +0900 | [diff] [blame] | 93 | if (n > 0 && dst[0] == '.') dst[0] = '\0'; |
| 94 | return (n); |
Bernie Innocenti | d1cc724 | 2018-09-11 18:41:37 +0900 | [diff] [blame] | 95 | } |
| 96 | |
| 97 | /* |
| 98 | * Pack domain name 'exp_dn' in presentation form into 'comp_dn'. |
| 99 | * Return the size of the compressed name or -1. |
| 100 | * 'length' is the size of the array pointed to by 'comp_dn'. |
| 101 | */ |
Bernie Innocenti | eb0c81a | 2018-09-11 18:55:58 +0900 | [diff] [blame] | 102 | int dn_comp(const char* src, u_char* dst, int dstsiz, u_char** dnptrs, u_char** lastdnptr) { |
| 103 | return (ns_name_compress(src, dst, (size_t) dstsiz, (const u_char**) dnptrs, |
| 104 | (const u_char**) lastdnptr)); |
Bernie Innocenti | d1cc724 | 2018-09-11 18:41:37 +0900 | [diff] [blame] | 105 | } |
| 106 | |
| 107 | /* |
| 108 | * Skip over a compressed domain name. Return the size or -1. |
| 109 | */ |
Bernie Innocenti | eb0c81a | 2018-09-11 18:55:58 +0900 | [diff] [blame] | 110 | int dn_skipname(const u_char* ptr, const u_char* eom) { |
| 111 | const u_char* saveptr = ptr; |
Bernie Innocenti | d1cc724 | 2018-09-11 18:41:37 +0900 | [diff] [blame] | 112 | |
Bernie Innocenti | eb0c81a | 2018-09-11 18:55:58 +0900 | [diff] [blame] | 113 | if (ns_name_skip(&ptr, eom) == -1) return (-1); |
| 114 | return (ptr - saveptr); |
Bernie Innocenti | d1cc724 | 2018-09-11 18:41:37 +0900 | [diff] [blame] | 115 | } |
| 116 | |
| 117 | /* |
| 118 | * Verify that a domain name uses an acceptable character set. |
| 119 | */ |
| 120 | |
| 121 | /* |
| 122 | * Note the conspicuous absence of ctype macros in these definitions. On |
| 123 | * non-ASCII hosts, we can't depend on string literals or ctype macros to |
| 124 | * tell us anything about network-format data. The rest of the BIND system |
| 125 | * is not careful about this, but for some reason, we're doing it right here. |
| 126 | */ |
| 127 | |
| 128 | /* BIONIC: We also accept underscores in the middle of labels. |
| 129 | * This extension is needed to make resolution on some VPN networks |
| 130 | * work properly. |
| 131 | */ |
| 132 | |
| 133 | #define PERIOD 0x2e |
Bernie Innocenti | eb0c81a | 2018-09-11 18:55:58 +0900 | [diff] [blame] | 134 | #define hyphenchar(c) ((c) == 0x2d) |
Bernie Innocenti | d1cc724 | 2018-09-11 18:41:37 +0900 | [diff] [blame] | 135 | #define bslashchar(c) ((c) == 0x5c) |
| 136 | #define periodchar(c) ((c) == PERIOD) |
| 137 | #define asterchar(c) ((c) == 0x2a) |
Bernie Innocenti | eb0c81a | 2018-09-11 18:55:58 +0900 | [diff] [blame] | 138 | #define alphachar(c) (((c) >= 0x41 && (c) <= 0x5a) || ((c) >= 0x61 && (c) <= 0x7a)) |
Bernie Innocenti | d1cc724 | 2018-09-11 18:41:37 +0900 | [diff] [blame] | 139 | #define digitchar(c) ((c) >= 0x30 && (c) <= 0x39) |
Bernie Innocenti | eb0c81a | 2018-09-11 18:55:58 +0900 | [diff] [blame] | 140 | #define underscorechar(c) ((c) == 0x5f) |
Bernie Innocenti | d1cc724 | 2018-09-11 18:41:37 +0900 | [diff] [blame] | 141 | |
| 142 | #define borderchar(c) (alphachar(c) || digitchar(c)) |
| 143 | #define middlechar(c) (borderchar(c) || hyphenchar(c) || underscorechar(c)) |
Bernie Innocenti | eb0c81a | 2018-09-11 18:55:58 +0900 | [diff] [blame] | 144 | #define domainchar(c) ((c) > 0x20 && (c) < 0x7f) |
Bernie Innocenti | d1cc724 | 2018-09-11 18:41:37 +0900 | [diff] [blame] | 145 | |
Bernie Innocenti | eb0c81a | 2018-09-11 18:55:58 +0900 | [diff] [blame] | 146 | int res_hnok(const char* dn) { |
| 147 | int pch = PERIOD, ch = *dn++; |
Bernie Innocenti | d1cc724 | 2018-09-11 18:41:37 +0900 | [diff] [blame] | 148 | |
Bernie Innocenti | eb0c81a | 2018-09-11 18:55:58 +0900 | [diff] [blame] | 149 | while (ch != '\0') { |
| 150 | int nch = *dn++; |
Bernie Innocenti | d1cc724 | 2018-09-11 18:41:37 +0900 | [diff] [blame] | 151 | |
Bernie Innocenti | eb0c81a | 2018-09-11 18:55:58 +0900 | [diff] [blame] | 152 | if (periodchar(ch)) { |
| 153 | ; |
| 154 | } else if (periodchar(pch)) { |
| 155 | if (!borderchar(ch)) return (0); |
| 156 | } else if (periodchar(nch) || nch == '\0') { |
| 157 | if (!borderchar(ch)) return (0); |
| 158 | } else { |
| 159 | if (!middlechar(ch)) return (0); |
| 160 | } |
| 161 | pch = ch, ch = nch; |
| 162 | } |
| 163 | return (1); |
Bernie Innocenti | d1cc724 | 2018-09-11 18:41:37 +0900 | [diff] [blame] | 164 | } |
| 165 | |
| 166 | /* |
| 167 | * hostname-like (A, MX, WKS) owners can have "*" as their first label |
| 168 | * but must otherwise be as a host name. |
| 169 | */ |
Bernie Innocenti | eb0c81a | 2018-09-11 18:55:58 +0900 | [diff] [blame] | 170 | int res_ownok(const char* dn) { |
| 171 | if (asterchar(dn[0])) { |
| 172 | if (periodchar(dn[1])) return (res_hnok(dn + 2)); |
| 173 | if (dn[1] == '\0') return (1); |
| 174 | } |
| 175 | return (res_hnok(dn)); |
Bernie Innocenti | d1cc724 | 2018-09-11 18:41:37 +0900 | [diff] [blame] | 176 | } |
| 177 | |
| 178 | /* |
| 179 | * SOA RNAMEs and RP RNAMEs can have any printable character in their first |
| 180 | * label, but the rest of the name has to look like a host name. |
| 181 | */ |
Bernie Innocenti | eb0c81a | 2018-09-11 18:55:58 +0900 | [diff] [blame] | 182 | int res_mailok(const char* dn) { |
| 183 | int ch, escaped = 0; |
Bernie Innocenti | d1cc724 | 2018-09-11 18:41:37 +0900 | [diff] [blame] | 184 | |
Bernie Innocenti | eb0c81a | 2018-09-11 18:55:58 +0900 | [diff] [blame] | 185 | /* "." is a valid missing representation */ |
| 186 | if (*dn == '\0') return (1); |
Bernie Innocenti | d1cc724 | 2018-09-11 18:41:37 +0900 | [diff] [blame] | 187 | |
Bernie Innocenti | eb0c81a | 2018-09-11 18:55:58 +0900 | [diff] [blame] | 188 | /* otherwise <label>.<hostname> */ |
| 189 | while ((ch = *dn++) != '\0') { |
| 190 | if (!domainchar(ch)) return (0); |
| 191 | if (!escaped && periodchar(ch)) break; |
| 192 | if (escaped) |
| 193 | escaped = 0; |
| 194 | else if (bslashchar(ch)) |
| 195 | escaped = 1; |
| 196 | } |
| 197 | if (periodchar(ch)) return (res_hnok(dn)); |
| 198 | return (0); |
Bernie Innocenti | d1cc724 | 2018-09-11 18:41:37 +0900 | [diff] [blame] | 199 | } |
| 200 | |
| 201 | /* |
| 202 | * This function is quite liberal, since RFC 1034's character sets are only |
| 203 | * recommendations. |
| 204 | */ |
Bernie Innocenti | eb0c81a | 2018-09-11 18:55:58 +0900 | [diff] [blame] | 205 | int res_dnok(const char* dn) { |
| 206 | int ch; |
Bernie Innocenti | d1cc724 | 2018-09-11 18:41:37 +0900 | [diff] [blame] | 207 | |
Bernie Innocenti | eb0c81a | 2018-09-11 18:55:58 +0900 | [diff] [blame] | 208 | while ((ch = *dn++) != '\0') |
| 209 | if (!domainchar(ch)) return (0); |
| 210 | return (1); |
Bernie Innocenti | d1cc724 | 2018-09-11 18:41:37 +0900 | [diff] [blame] | 211 | } |