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/* |
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* ircd-hybrid: an advanced, lightweight Internet Relay Chat Daemon (ircd) |
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* |
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* Copyright (c) 1997-2016 ircd-hybrid development team |
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* |
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* This program is free software; you can redistribute it and/or modify |
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* it under the terms of the GNU General Public License as published by |
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* the Free Software Foundation; either version 2 of the License, or |
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* (at your option) any later version. |
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* |
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* This program is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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* GNU General Public License for more details. |
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* |
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* You should have received a copy of the GNU General Public License |
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* along with this program; if not, write to the Free Software |
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 |
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* USA |
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*/ |
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|
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/*! \file res.h |
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* \brief ircd resolver functions |
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* \version $Id$ |
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*/ |
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|
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#ifndef INCLUDED_res_h |
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#define INCLUDED_res_h |
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|
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#include "config.h" |
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|
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/* |
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* From RFC 1035: |
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* |
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* Domain names in messages are expressed in terms of a sequence of labels. |
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* Each label is represented as a one octet length field followed by that |
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* number of octets. Since every domain name ends with the null label of |
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* the root, a domain name is terminated by a length byte of zero. The |
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* high order two bits of every length octet must be zero, and the |
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* remaining six bits of the length field limit the label to 63 octets or |
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* less. |
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* |
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* To simplify implementations, the total length of a domain name (i.e., |
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* label octets and label length octets) is restricted to 255 octets or |
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* less. |
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*/ |
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#define RFC1035_MAX_DOMAIN_LENGTH 255 |
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|
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|
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/* Here we define some values lifted from nameser.h */ |
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#define NS_NOTIFY_OP 4 |
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#define NS_INT16SZ 2 |
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#define NS_IN6ADDRSZ 16 |
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#define NS_INADDRSZ 4 |
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#define NS_INT32SZ 4 |
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#define NS_CMPRSFLGS 0xc0 |
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#define NS_MAXCDNAME 255 |
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#define QUERY 0 |
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#define IQUERY 1 |
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#define NO_ERRORS 0 |
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#define SERVFAIL 2 |
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#define NXDOMAIN 3 |
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#define T_A 1 |
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#define T_AAAA 28 |
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#define T_PTR 12 |
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#define T_CNAME 5 |
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#define T_NULL 10 |
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#define C_IN 1 |
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#define QFIXEDSZ 4 |
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#define RRFIXEDSZ 10 |
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#define HFIXEDSZ 12 |
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|
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|
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typedef struct |
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{ |
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unsigned id :16; /* query identification number */ |
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#ifdef WORDS_BIGENDIAN |
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/* fields in third byte */ |
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unsigned qr: 1; /* response flag */ |
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unsigned opcode: 4; /* purpose of message */ |
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unsigned aa: 1; /* authoritive answer */ |
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unsigned tc: 1; /* truncated message */ |
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unsigned rd: 1; /* recursion desired */ |
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|
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/* fields in fourth byte */ |
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unsigned ra: 1; /* recursion available */ |
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unsigned unused :1; /* unused bits (MBZ as of 4.9.3a3) */ |
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unsigned ad: 1; /* authentic data from named */ |
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unsigned cd: 1; /* checking disabled by resolver */ |
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unsigned rcode :4; /* response code */ |
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#else |
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/* fields in third byte */ |
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unsigned rd :1; /* recursion desired */ |
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unsigned tc :1; /* truncated message */ |
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unsigned aa :1; /* authoritive answer */ |
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unsigned opcode :4; /* purpose of message */ |
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unsigned qr :1; /* response flag */ |
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|
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/* fields in fourth byte */ |
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unsigned rcode :4; /* response code */ |
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unsigned cd: 1; /* checking disabled by resolver */ |
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unsigned ad: 1; /* authentic data from named */ |
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unsigned unused :1; /* unused bits (MBZ as of 4.9.3a3) */ |
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unsigned ra :1; /* recursion available */ |
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#endif |
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/* remaining bytes */ |
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unsigned qdcount :16; /* number of question entries */ |
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unsigned ancount :16; /* number of answer entries */ |
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unsigned nscount :16; /* number of authority entries */ |
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unsigned arcount :16; /* number of resource entries */ |
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} HEADER; |
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|
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typedef void (*dns_callback_fnc)(void *, const struct irc_ssaddr *, const char *, size_t); |
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|
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extern void init_resolver(void); |
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extern void restart_resolver(void); |
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extern void delete_resolver_queries(const void *); |
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extern void gethost_byname_type(dns_callback_fnc , void *, const char *, int); |
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extern void gethost_byaddr(dns_callback_fnc, void *, const struct irc_ssaddr *); |
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#endif |
