nameser.h

DHCP动态IP获取的源代码

/*
 * ++Copyright++ 1983, 1989, 1993
 * -
 * Copyright (c) 1983, 1989, 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.
 * 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.
 * -
 * 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.
 * -
 * --Copyright--
 */

/*
 *      @(#)nameser.h	8.1 (Berkeley) 6/2/93
 *	$Id: nameser.h,v 8.3 1995/08/21 01:27:12 vixie Exp 
 */

#ifndef _NAMESER_H_
#define	_NAMESER_H_

/*
 * Define constants based on rfc883
 */
#define PACKETSZ	512		/* maximum packet size */
#define MAXDNAME	256		/* maximum domain name */
#define MAXCDNAME	255		/* maximum compressed domain name */
#define MAXLABEL	63		/* maximum length of domain label */
#define	HFIXEDSZ	12		/* #/bytes of fixed data in header */
#define QFIXEDSZ	4		/* #/bytes of fixed data in query */
#define RRFIXEDSZ	10		/* #/bytes of fixed data in r record */
#define	INT32SZ		4		/* for systems without 32-bit ints */
#define	INT16SZ		2		/* for systems without 16-bit ints */
#define	INADDRSZ	4		/* for sizeof(struct inaddr) != 4 */

/*
 * Internet nameserver port number
 */
#define NAMESERVER_PORT	53

/*
 * Currently defined opcodes
 */
#define QUERY		0x0		/* standard query */
#define IQUERY		0x1		/* inverse query */
#define STATUS		0x2		/* nameserver status query */
/*#define xxx		0x3*/		/* 0x3 reserved */
#define	NS_NOTIFY_OP	0x4		/* notify secondary of SOA change */
#ifdef ALLOW_UPDATES
	/* non standard - supports ALLOW_UPDATES stuff from Mike Schwartz */
# define UPDATEA	0x9		/* add resource record */
# define UPDATED	0xa		/* delete a specific resource record */
# define UPDATEDA	0xb		/* delete all named resource record */
# define UPDATEM	0xc		/* modify a specific resource record */
# define UPDATEMA	0xd		/* modify all named resource record */
# define ZONEINIT	0xe		/* initial zone transfer */
# define ZONEREF	0xf		/* incremental zone referesh */
#endif

/*
 * Currently defined response codes
 */
#define NOERROR		0		/* no error */
#define FORMERR		1		/* format error */
#define SERVFAIL	2		/* server failure */
#define NXDOMAIN	3		/* non existent domain */
#define NOTIMP		4		/* not implemented */
#define REFUSED		5		/* query refused */
#ifdef ALLOW_UPDATES
	/* non standard */
# define NOCHANGE	0xf		/* update failed to change db */
#endif

/*
 * Type values for resources and queries
 */
#define T_A		1		/* host address */
#define T_NS		2		/* authoritative server */
#define T_MD		3		/* mail destination */
#define T_MF		4		/* mail forwarder */
#define T_CNAME		5		/* canonical name */
#define T_SOA		6		/* start of authority zone */
#define T_MB		7		/* mailbox domain name */
#define T_MG		8		/* mail group member */
#define T_MR		9		/* mail rename name */
#define T_NULL		10		/* null resource record */
#define T_WKS		11		/* well known service */
#define T_PTR		12		/* domain name pointer */
#define T_HINFO		13		/* host information */
#define T_MINFO		14		/* mailbox information */
#define T_MX		15		/* mail routing information */
#define T_TXT		16		/* text strings */
#define	T_RP		17		/* responsible person */
#define T_AFSDB		18		/* AFS cell database */
#define T_X25		19		/* X_25 calling address */
#define T_ISDN		20		/* ISDN calling address */
#define T_RT		21		/* router */
#define T_NSAP		22		/* NSAP address */
#define T_NSAP_PTR	23		/* reverse NSAP lookup (deprecated) */
#define	T_SIG		24		/* security signature */
#define	T_KEY		25		/* security key */
#define	T_PX		26		/* X.400 mail mapping */
#define	T_GPOS		27		/* geographical position (withdrawn) */
#define	T_AAAA		28		/* IP6 Address */
#define	T_LOC		29		/* Location Information */
	/* non standard */
#define T_UINFO		100		/* user (finger) information */
#define T_UID		101		/* user ID */
#define T_GID		102		/* group ID */
#define T_UNSPEC	103		/* Unspecified format (binary data) */
	/* Query type values which do not appear in resource records */
#define T_AXFR		252		/* transfer zone of authority */
#define T_MAILB		253		/* transfer mailbox records */
#define T_MAILA		254		/* transfer mail agent records */
#define T_ANY		255		/* wildcard match */

/*
 * Values for class field
 */

#define C_IN		1		/* the arpa internet */
#define C_CHAOS		3		/* for chaos net (MIT) */
#define C_HS		4		/* for Hesiod name server (MIT) (XXX) */
	/* Query class values which do not appear in resource records */
#define C_ANY		255		/* wildcard match */

/*
 * Status return codes for T_UNSPEC conversion routines
 */
#define CONV_SUCCESS	0
#define CONV_OVERFLOW	(-1)
#define CONV_BADFMT	(-2)
#define CONV_BADCKSUM	(-3)
#define CONV_BADBUFLEN	(-4)

/*
 * Structure for query header.  The order of the fields is machine- and
 * compiler-dependent, depending on the byte/bit order and the layout
 * of bit fields.  We use bit fields only in int variables, as this
 * is all ANSI requires.  This requires a somewhat confusing rearrangement.
 */

typedef struct {
	unsigned	id :16;		/* query identification number */
#if BYTE_ORDER == BIG_ENDIAN
			/* fields in third byte */
	unsigned	qr: 1;		/* response flag */
	unsigned	opcode: 4;	/* purpose of message */
	unsigned	aa: 1;		/* authoritive answer */
	unsigned	tc: 1;		/* truncated message */
	unsigned	rd: 1;		/* recursion desired */
			/* fields in fourth byte */
	unsigned	ra: 1;		/* recursion available */
	unsigned	pr:1;		/* primary server required (non standard) */
	unsigned	unused :2;	/* unused bits (MBZ as of 4.9.3a3) */
	unsigned	rcode :4;	/* response code */
#endif
#if BYTE_ORDER == LITTLE_ENDIAN || BYTE_ORDER == PDP_ENDIAN
			/* fields in third byte */
	unsigned	rd :1;		/* recursion desired */
	unsigned	tc :1;		/* truncated message */
	unsigned	aa :1;		/* authoritive answer */
	unsigned	opcode :4;	/* purpose of message */
	unsigned	qr :1;		/* response flag */
			/* fields in fourth byte */
	unsigned	rcode :4;	/* response code */
	unsigned	unused :2;	/* unused bits (MBZ as of 4.9.3a3) */
	unsigned	pr:1;		/* primary server required (non standard) */
	unsigned	ra :1;		/* recursion available */
#endif
			/* remaining bytes */
	unsigned	qdcount :16;	/* number of question entries */
	unsigned	ancount :16;	/* number of answer entries */
	unsigned	nscount :16;	/* number of authority entries */
	unsigned	arcount :16;	/* number of resource entries */
} HEADER;

/*
 * Defines for handling compressed domain names
 */
#define INDIR_MASK	0xc0

/*
 * Structure for passing resource records around.
 */
struct rrec {
	int16_t		r_zone;			/* zone number */
	int16_t		r_class;		/* class number */
	int16_t		r_type;			/* type number */
	u_int32_t	r_ttl;			/* time to live */
	int		r_size;			/* size of data area */
	char		*r_data;		/* pointer to data */
};

#endif /* !_NAMESER_H_ */