/* @(#) $Header: /tcpdump/master/tcpdump/ip.h,v 1.12 2007-09-14 01:29:28 guy Exp $ (LBL) *//* * Copyright (c) 1982, 1986, 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. * *	@(#)ip.h	8.2 (Berkeley) 6/1/94 *//* * Definitions for internet protocol version 4. * Per RFC 791, September 1981. */#define	IPVERSION	4/* * Structure of an internet header, naked of options. * * We declare ip_len and ip_off to be short, rather than u_short * pragmatically since otherwise unsigned comparisons can result * against negative integers quite easily, and fail in subtle ways. */struct ip {	u_int8_t	ip_vhl;		/* header length, version */#define IP_V(ip)	(((ip)->ip_vhl & 0xf0) >> 4)#define IP_HL(ip)	((ip)->ip_vhl & 0x0f)	u_int8_t	ip_tos;		/* type of service */	u_int16_t	ip_len;		/* total length */	u_int16_t	ip_id;		/* identification */	u_int16_t	ip_off;		/* fragment offset field */#define	IP_DF 0x4000			/* dont fragment flag */#define	IP_MF 0x2000			/* more fragments flag */#define	IP_OFFMASK 0x1fff		/* mask for fragmenting bits */	u_int8_t	ip_ttl;		/* time to live */	u_int8_t	ip_p;		/* protocol */	u_int16_t	ip_sum;		/* checksum */	struct	in_addr ip_src,ip_dst;	/* source and dest address */};#define	IP_MAXPACKET	65535		/* maximum packet size *//* * Definitions for IP type of service (ip_tos) */#define	IPTOS_LOWDELAY		0x10#define	IPTOS_THROUGHPUT	0x08#define	IPTOS_RELIABILITY	0x04/* * Definitions for IP precedence (also in ip_tos) (hopefully unused) */#define	IPTOS_PREC_NETCONTROL		0xe0#define	IPTOS_PREC_INTERNETCONTROL	0xc0#define	IPTOS_PREC_CRITIC_ECP		0xa0#define	IPTOS_PREC_FLASHOVERRIDE	0x80#define	IPTOS_PREC_FLASH		0x60#define	IPTOS_PREC_IMMEDIATE		0x40#define	IPTOS_PREC_PRIORITY		0x20#define	IPTOS_PREC_ROUTINE		0x00/* * Definitions for options. */#define	IPOPT_COPIED(o)		((o)&0x80)#define	IPOPT_CLASS(o)		((o)&0x60)#define	IPOPT_NUMBER(o)		((o)&0x1f)#define	IPOPT_CONTROL		0x00#define	IPOPT_RESERVED1		0x20#define	IPOPT_DEBMEAS		0x40#define	IPOPT_RESERVED2		0x60#define	IPOPT_EOL		0		/* end of option list */#define	IPOPT_NOP		1		/* no operation */#define	IPOPT_RR		7		/* record packet route */#define	IPOPT_TS		68		/* timestamp */#define	IPOPT_RFC1393           82              /* traceroute RFC 1393 */#define	IPOPT_SECURITY		130		/* provide s,c,h,tcc */#define	IPOPT_LSRR		131		/* loose source route */#define	IPOPT_SATID		136		/* satnet id */#define	IPOPT_SSRR		137		/* strict source route */#define IPOPT_RA                148             /* router-alert, rfc2113 *//* * Offsets to fields in options other than EOL and NOP. */#define	IPOPT_OPTVAL		0		/* option ID */#define	IPOPT_OLEN		1		/* option length */#define IPOPT_OFFSET		2		/* offset within option */#define	IPOPT_MINOFF		4		/* min value of above *//* * Time stamp option structure. */struct	ip_timestamp {	u_int8_t	ipt_code;	/* IPOPT_TS */	u_int8_t	ipt_len;	/* size of structure (variable) */	u_int8_t	ipt_ptr;	/* index of current entry */	u_int8_t	ipt_oflwflg;	/* flags, overflow counter */#define IPTS_OFLW(ip)	(((ipt)->ipt_oflwflg & 0xf0) >> 4)#define IPTS_FLG(ip)	((ipt)->ipt_oflwflg & 0x0f)	union ipt_timestamp {		u_int32_t ipt_time[1];		struct	ipt_ta {			struct in_addr ipt_addr;			u_int32_t ipt_time;		} ipt_ta[1];	} ipt_timestamp;};/* flag bits for ipt_flg */#define	IPOPT_TS_TSONLY		0		/* timestamps only */#define	IPOPT_TS_TSANDADDR	1		/* timestamps and addresses */#define	IPOPT_TS_PRESPEC	3		/* specified modules only *//* bits for security (not byte swapped) */#define	IPOPT_SECUR_UNCLASS	0x0000#define	IPOPT_SECUR_CONFID	0xf135#define	IPOPT_SECUR_EFTO	0x789a#define	IPOPT_SECUR_MMMM	0xbc4d#define	IPOPT_SECUR_RESTR	0xaf13#define	IPOPT_SECUR_SECRET	0xd788#define	IPOPT_SECUR_TOPSECRET	0x6bc5/* * Internet implementation parameters. */#define	MAXTTL		255		/* maximum time to live (seconds) */#define	IPDEFTTL	64		/* default ttl, from RFC 1340 */#define	IPFRAGTTL	60		/* time to live for frags, slowhz */#define	IPTTLDEC	1		/* subtracted when forwarding */#define	IP_MSS		576		/* default maximum segment size *//* in print-ip.c */extern u_int32_t ip_finddst(const struct ip *);