| /* Domain name processing functions. |
| Copyright (C) 1995-2018 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| |
| The GNU C Library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Lesser General Public |
| License as published by the Free Software Foundation; either |
| version 2.1 of the License, or (at your option) any later version. |
| |
| The GNU C Library is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with the GNU C Library; if not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| /* |
| * Copyright (c) 1985, 1993 |
| * The Regents of the University of California. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * 4. Neither the name of the University nor the names of its contributors |
| * may be used to endorse or promote products derived from this software |
| * without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| * SUCH DAMAGE. |
| */ |
| |
| /* |
| * Portions Copyright (c) 1993 by Digital Equipment Corporation. |
| * |
| * Permission to use, copy, modify, and distribute this software for any |
| * purpose with or without fee is hereby granted, provided that the above |
| * copyright notice and this permission notice appear in all copies, and that |
| * the name of Digital Equipment Corporation not be used in advertising or |
| * publicity pertaining to distribution of the document or software without |
| * specific, written prior permission. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL |
| * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT |
| * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL |
| * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR |
| * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS |
| * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS |
| * SOFTWARE. |
| */ |
| |
| /* |
| * Portions Copyright (c) 1996-1999 by Internet Software Consortium. |
| * |
| * Permission to use, copy, modify, and distribute this software for any |
| * purpose with or without fee is hereby granted, provided that the above |
| * copyright notice and this permission notice appear in all copies. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS |
| * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE |
| * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL |
| * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR |
| * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS |
| * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS |
| * SOFTWARE. |
| */ |
| |
| #include <sys/types.h> |
| #include <sys/param.h> |
| #include <netinet/in.h> |
| #include <arpa/nameser.h> |
| #include <ctype.h> |
| #include <resolv.h> |
| #include <stdio.h> |
| #include <string.h> |
| #include <unistd.h> |
| |
| /* |
| * Expand compressed domain name 'comp_dn' to full domain name. |
| * 'msg' is a pointer to the beginning of the message, |
| * 'eomorig' points to the first location after the message, |
| * 'exp_dn' is a pointer to a buffer of size 'length' for the result. |
| * Return size of compressed name or -1 if there was an error. |
| */ |
| int |
| dn_expand(const u_char *msg, const u_char *eom, const u_char *src, |
| char *dst, int dstsiz) |
| { |
| int n = ns_name_uncompress(msg, eom, src, dst, (size_t)dstsiz); |
| |
| if (n > 0 && dst[0] == '.') |
| dst[0] = '\0'; |
| return (n); |
| } |
| libresolv_hidden_def (dn_expand) |
| |
| /* |
| * Pack domain name 'exp_dn' in presentation form into 'comp_dn'. |
| * Return the size of the compressed name or -1. |
| * 'length' is the size of the array pointed to by 'comp_dn'. |
| */ |
| int |
| dn_comp(const char *src, u_char *dst, int dstsiz, |
| u_char **dnptrs, u_char **lastdnptr) |
| { |
| return (ns_name_compress(src, dst, (size_t)dstsiz, |
| (const u_char **)dnptrs, |
| (const u_char **)lastdnptr)); |
| } |
| libresolv_hidden_def (dn_comp) |
| |
| /* |
| * Skip over a compressed domain name. Return the size or -1. |
| */ |
| int |
| dn_skipname(const u_char *ptr, const u_char *eom) { |
| const u_char *saveptr = ptr; |
| |
| if (ns_name_skip(&ptr, eom) == -1) |
| return (-1); |
| return (ptr - saveptr); |
| } |
| libresolv_hidden_def (dn_skipname) |
| |
| /* Return true if the string consists of printable ASCII characters |
| only. */ |
| static bool |
| printable_string (const char *dn) |
| { |
| while (true) |
| { |
| char ch = *dn; |
| if (ch == '\0') |
| return true; |
| if (ch <= ' ' || ch > '~') |
| return false; |
| ++dn; |
| } |
| } |
| |
| /* Return true if DN points to a name consisting only of [0-9a-zA-Z_-] |
| characters. DN must be in DNS wire format, without |
| compression. */ |
| static bool |
| binary_hnok (const unsigned char *dn) |
| { |
| while (true) |
| { |
| size_t label_length = *dn; |
| if (label_length == 0) |
| break; |
| ++dn; |
| const unsigned char *label_end = dn + label_length; |
| do |
| { |
| unsigned char ch = *dn; |
| if (!(('0' <= ch && ch <= '9') |
| || ('A' <= ch && ch <= 'Z') |
| || ('a' <= ch && ch <= 'z') |
| || ch == '-' || ch == '_')) |
| return false; |
| ++dn; |
| } |
| while (dn < label_end); |
| } |
| return true; |
| } |
| |
| /* Return true if the binary domain name has a first labels which |
| starts with '-'. */ |
| static inline bool |
| binary_leading_dash (const unsigned char *dn) |
| { |
| return dn[0] > 0 && dn[1] == '-'; |
| } |
| |
| /* Return 1 if res_hnok is a valid host name. Labels must only |
| contain [0-9a-zA-Z_-] characters, and the name must not start with |
| a '-'. The latter is to avoid confusion with program options. */ |
| int |
| res_hnok (const char *dn) |
| { |
| unsigned char buf[NS_MAXCDNAME]; |
| if (!printable_string (dn) |
| || ns_name_pton (dn, buf, sizeof (buf)) < 0 |
| || binary_leading_dash (buf)) |
| return 0; |
| return binary_hnok (buf); |
| } |
| libresolv_hidden_def (res_hnok) |
| |
| /* Hostname-like (A, MX, WKS) owners can have "*" as their first label |
| but must otherwise be as a host name. */ |
| int |
| res_ownok (const char *dn) |
| { |
| unsigned char buf[NS_MAXCDNAME]; |
| if (!printable_string (dn) |
| || ns_name_pton (dn, buf, sizeof (buf)) < 0 |
| || binary_leading_dash (buf)) |
| return 0; |
| if (buf[0] == 1 && buf [1] == '*') |
| /* Skip over the leading "*." part. */ |
| return binary_hnok (buf + 2); |
| else |
| return binary_hnok (buf); |
| } |
| |
| /* SOA RNAMEs and RP RNAMEs can have any byte in their first label, |
| but the rest of the name has to look like a host name. */ |
| int |
| res_mailok (const char *dn) |
| { |
| unsigned char buf[NS_MAXCDNAME]; |
| if (!printable_string (dn) |
| || ns_name_pton (dn, buf, sizeof (buf)) < 0) |
| return 0; |
| unsigned char label_length = buf[0]; |
| /* "." is a valid missing representation */ |
| if (label_length == 0) |
| return 1; |
| /* Skip over the first label. */ |
| unsigned char *tail = buf + 1 + label_length; |
| if (*tail == 0) |
| /* More than one label is required (except for "."). */ |
| return 0; |
| return binary_hnok (tail); |
| } |
| |
| /* Return 1 if DN is a syntactically valid domain name. Empty names |
| are accepted. */ |
| int |
| res_dnok (const char *dn) |
| { |
| unsigned char buf[NS_MAXCDNAME]; |
| return printable_string (dn) && ns_name_pton (dn, buf, sizeof (buf)) >= 0; |
| } |
| libresolv_hidden_def (res_dnok) |
| |
| /* |
| * This module must export the following externally-visible symbols: |
| * ___putlong |
| * ___putshort |
| * __getlong |
| * __getshort |
| * Note that one _ comes from C and the others come from us. |
| */ |
| void __putlong(uint32_t src, u_char *dst) { ns_put32(src, dst); } |
| libresolv_hidden_def (__putlong) |
| void __putshort(uint16_t src, u_char *dst) { ns_put16(src, dst); } |
| libresolv_hidden_def (__putshort) |
| uint32_t _getlong(const u_char *src) { return (ns_get32(src)); } |
| uint16_t _getshort(const u_char *src) { return (ns_get16(src)); } |
| |
| |
| #include <shlib-compat.h> |
| |
| #if SHLIB_COMPAT(libresolv, GLIBC_2_0, GLIBC_2_2) |
| # undef dn_expand |
| weak_alias (__dn_expand, dn_expand); |
| #endif |
