resolv.h

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/*
 * Copyright (c) 1983, 1987, 1989
 *    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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 * 	This product includes software developed by the University of
 * 	California, Berkeley and its contributors.
 * 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.
 */

/*
 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
 * 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 ISC DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC 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.
 */

/*%
 *	@(#)resolv.h	8.1 (Berkeley) 6/2/93
 *	$Id: resolv.h,v 1.19.18.3 2005/08/25 04:43:51 marka Exp $
 */

#ifndef _RESOLV_H_
#define	_RESOLV_H_

#include <sys/param.h>
#if (!defined(BSD)) || (BSD < 199306)
# include <sys/bitypes.h>
#else
# include <sys/types.h>
#endif
#include <sys/cdefs.h>
#include <sys/socket.h>
#include <stdio.h>
#include <arpa/nameser.h>

/*%
 * Revision information.  This is the release date in YYYYMMDD format.
 * It can change every day so the right thing to do with it is use it
 * in preprocessor commands such as "#if (__RES > 19931104)".  Do not
 * compare for equality; rather, use it to determine whether your resolver
 * is new enough to contain a certain feature.
 */

#define	__RES	20030124

/*%
 * This used to be defined in res_query.c, now it's in herror.c.
 * [XXX no it's not.  It's in irs/irs_data.c]
 * It was
 * never extern'd by any *.h file before it was placed here.  For thread
 * aware programs, the last h_errno value set is stored in res->h_errno.
 *
 * XXX:	There doesn't seem to be a good reason for exposing RES_SET_H_ERRNO
 *	(and __h_errno_set) to the public via <resolv.h>.
 * XXX:	__h_errno_set is really part of IRS, not part of the resolver.
 *	If somebody wants to build and use a resolver that doesn't use IRS,
 *	what do they do?  Perhaps something like
 *		#ifdef WANT_IRS
 *		# define RES_SET_H_ERRNO(r,x) __h_errno_set(r,x)
 *		#else
 *		# define RES_SET_H_ERRNO(r,x) (h_errno = (r)->res_h_errno = (x))
 *		#endif
 */

#define RES_SET_H_ERRNO(r,x) __h_errno_set(r,x)
struct __res_state; /*%< forward */
__BEGIN_DECLS
void __h_errno_set(struct __res_state *res, int err);
__END_DECLS

/*%
 * Resolver configuration file.
 * Normally not present, but may contain the address of the
 * initial name server(s) to query and the domain search list.
 */

#ifndef _PATH_RESCONF
#define _PATH_RESCONF        "/etc/resolv.conf"
#endif

typedef enum { res_goahead, res_nextns, res_modified, res_done, res_error }
	res_sendhookact;

#ifndef __PMT
#if defined(__STDC__) || defined(__cplusplus)
#define __PMT(args) args
#else
#define __PMT(args) ()
#endif
#endif

typedef res_sendhookact (*res_send_qhook)__PMT((struct sockaddr * const *,
						const u_char **, int *,
						u_char *, int, int *));

typedef res_sendhookact (*res_send_rhook)__PMT((const struct sockaddr *,
						const u_char *, int, u_char *,
						int, int *));

struct res_sym {
	int		number;	   /*%< Identifying number, like T_MX */
	const char *	name;	   /*%< Its symbolic name, like "MX" */
	const char *	humanname; /*%< Its fun name, like "mail exchanger" */
};

/*%
 * Global defines and variables for resolver stub.
 */
#define	MAXNS			3	/*%< max # name servers we'll track */
#define	MAXDFLSRCH		3	/*%< # default domain levels to try */
#define	MAXDNSRCH		6	/*%< max # domains in search path */
#define	LOCALDOMAINPARTS	2	/*%< min levels in name that is "local" */
#define	RES_TIMEOUT		5	/*%< min. seconds between retries */
#define	MAXRESOLVSORT		10	/*%< number of net to sort on */
#define	RES_MAXNDOTS		15	/*%< should reflect bit field size */
#define	RES_MAXRETRANS		30	/*%< only for resolv.conf/RES_OPTIONS */
#define	RES_MAXRETRY		5	/*%< only for resolv.conf/RES_OPTIONS */
#define	RES_DFLRETRY		2	/*%< Default #/tries. */
#define	RES_MAXTIME		65535	/*%< Infinity, in milliseconds. */
struct __res_state_ext;

struct __res_state {
	int	retrans;	 	/*%< retransmission time interval */
	int	retry;			/*%< number of times to retransmit */
#ifdef sun
	u_int	options;		/*%< option flags - see below. */
#else
	u_long	options;		/*%< option flags - see below. */
#endif
	int	nscount;		/*%< number of name servers */
	struct sockaddr_in
		nsaddr_list[MAXNS];	/*%< address of name server */
#define	nsaddr	nsaddr_list[0]		/*%< for backward compatibility */
	u_short	id;			/*%< current message id */
	char	*dnsrch[MAXDNSRCH+1];	/*%< components of domain to search */
	char	defdname[256];		/*%< default domain (deprecated) */
#ifdef sun
	u_int	pfcode;			/*%< RES_PRF_ flags - see below. */
#else
	u_long	pfcode;			/*%< RES_PRF_ flags - see below. */
#endif
	unsigned ndots:4;		/*%< threshold for initial abs. query */
	unsigned nsort:4;		/*%< number of elements in sort_list[] */
	char	unused[3];
	struct {
		struct in_addr	addr;
		u_int32_t	mask;
	} sort_list[MAXRESOLVSORT];
	res_send_qhook qhook;		/*%< query hook */
	res_send_rhook rhook;		/*%< response hook */
	int	res_h_errno;		/*%< last one set for this context */
	int	_vcsock;		/*%< PRIVATE: for res_send VC i/o */
	u_int	_flags;			/*%< PRIVATE: see below */
	u_int	_pad;			/*%< make _u 64 bit aligned */
	union {
		/* On an 32-bit arch this means 512b total. */
		char	pad[72 - 4*sizeof (int) - 2*sizeof (void *)];
		struct {
			u_int16_t		nscount;
			u_int16_t		nstimes[MAXNS];	/*%< ms. */
			int			nssocks[MAXNS];
			struct __res_state_ext *ext;	/*%< extention for IPv6 */
		} _ext;
	} _u;
};

typedef struct __res_state *res_state;

union res_sockaddr_union {
	struct sockaddr_in	sin;
#ifdef IN6ADDR_ANY_INIT
	struct sockaddr_in6	sin6;
#endif
#ifdef ISC_ALIGN64
	int64_t			__align64;	/*%< 64bit alignment */
#else
	int32_t			__align32;	/*%< 32bit alignment */
#endif
	char			__space[128];   /*%< max size */
};

/*%
 * Resolver flags (used to be discrete per-module statics ints).
 */
#define	RES_F_VC	0x00000001	/*%< socket is TCP */
#define	RES_F_CONN	0x00000002	/*%< socket is connected */
#define	RES_F_EDNS0ERR	0x00000004	/*%< EDNS0 caused errors */
#define	RES_F__UNUSED	0x00000008	/*%< (unused) */
#define	RES_F_LASTMASK	0x000000F0	/*%< ordinal server of last res_nsend */
#define	RES_F_LASTSHIFT	4		/*%< bit position of LASTMASK "flag" */
#define	RES_GETLAST(res) (((res)._flags & RES_F_LASTMASK) >> RES_F_LASTSHIFT)

/* res_findzonecut2() options */
#define	RES_EXHAUSTIVE	0x00000001	/*%< always do all queries */
#define	RES_IPV4ONLY	0x00000002	/*%< IPv4 only */
#define	RES_IPV6ONLY	0x00000004	/*%< IPv6 only */

/*%
 * Resolver options (keep these in synch with res_debug.c, please)
 */
#define RES_INIT	0x00000001	/*%< address initialized */
#define RES_DEBUG	0x00000002	/*%< print debug messages */
#define RES_AAONLY	0x00000004	/*%< authoritative answers only (!IMPL)*/
#define RES_USEVC	0x00000008	/*%< use virtual circuit */
#define RES_PRIMARY	0x00000010	/*%< query primary server only (!IMPL) */
#define RES_IGNTC	0x00000020	/*%< ignore trucation errors */
#define RES_RECURSE	0x00000040	/*%< recursion desired */
#define RES_DEFNAMES	0x00000080	/*%< use default domain name */
#define RES_STAYOPEN	0x00000100	/*%< Keep TCP socket open */
#define RES_DNSRCH	0x00000200	/*%< search up local domain tree */
#define	RES_INSECURE1	0x00000400	/*%< type 1 security disabled */
#define	RES_INSECURE2	0x00000800	/*%< type 2 security disabled */
#define	RES_NOALIASES	0x00001000	/*%< shuts off HOSTALIASES feature */
#define	RES_USE_INET6	0x00002000	/*%< use/map IPv6 in gethostbyname() */
#define RES_ROTATE	0x00004000	/*%< rotate ns list after each query */
#define	RES_NOCHECKNAME	0x00008000	/*%< do not check names for sanity. */
#define	RES_KEEPTSIG	0x00010000	/*%< do not strip TSIG records */
#define	RES_BLAST	0x00020000	/*%< blast all recursive servers */
#define RES_NOTLDQUERY	0x00100000	/*%< don't unqualified name as a tld */