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ip.h revision 1.16
      1 /*	$NetBSD: ip.h,v 1.16 1996/12/11 01:55:50 mycroft Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1982, 1986, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *	This product includes software developed by the University of
     18  *	California, Berkeley and its contributors.
     19  * 4. Neither the name of the University nor the names of its contributors
     20  *    may be used to endorse or promote products derived from this software
     21  *    without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33  * SUCH DAMAGE.
     34  *
     35  *	@(#)ip.h	8.1 (Berkeley) 6/10/93
     36  */
     37 
     38 /*
     39  * Definitions for internet protocol version 4.
     40  * Per RFC 791, September 1981.
     41  */
     42 #define	IPVERSION	4
     43 
     44 /*
     45  * Structure of an internet header, naked of options.
     46  */
     47 struct ip {
     48 #if BYTE_ORDER == LITTLE_ENDIAN
     49 	u_int8_t  ip_hl:4,		/* header length */
     50 		  ip_v:4;		/* version */
     51 #endif
     52 #if BYTE_ORDER == BIG_ENDIAN
     53 	u_int8_t  ip_v:4,		/* version */
     54 		  ip_hl:4;		/* header length */
     55 #endif
     56 	u_int8_t  ip_tos;		/* type of service */
     57 	u_int16_t ip_len;		/* total length */
     58 	u_int16_t ip_id;		/* identification */
     59 	u_int16_t ip_off;		/* fragment offset field */
     60 #define	IP_RF 0x8000			/* reserved fragment flag */
     61 #define	IP_DF 0x4000			/* dont fragment flag */
     62 #define	IP_MF 0x2000			/* more fragments flag */
     63 #define	IP_OFFMASK 0x1fff		/* mask for fragmenting bits */
     64 	u_int8_t  ip_ttl;		/* time to live */
     65 	u_int8_t  ip_p;			/* protocol */
     66 	u_int16_t ip_sum;		/* checksum */
     67 	struct	  in_addr ip_src, ip_dst; /* source and dest address */
     68 };
     69 
     70 #define	IP_MAXPACKET	65535		/* maximum packet size */
     71 
     72 /*
     73  * Definitions for IP type of service (ip_tos)
     74  */
     75 #define	IPTOS_LOWDELAY		0x10
     76 #define	IPTOS_THROUGHPUT	0x08
     77 #define	IPTOS_RELIABILITY	0x04
     78 /*	IPTOS_LOWCOST		0x02 XXX */
     79 
     80 /*
     81  * Definitions for IP precedence (also in ip_tos) (hopefully unused)
     82  */
     83 #define	IPTOS_PREC_NETCONTROL		0xe0
     84 #define	IPTOS_PREC_INTERNETCONTROL	0xc0
     85 #define	IPTOS_PREC_CRITIC_ECP		0xa0
     86 #define	IPTOS_PREC_FLASHOVERRIDE	0x80
     87 #define	IPTOS_PREC_FLASH		0x60
     88 #define	IPTOS_PREC_IMMEDIATE		0x40
     89 #define	IPTOS_PREC_PRIORITY		0x20
     90 #define	IPTOS_PREC_ROUTINE		0x00
     91 
     92 /*
     93  * Definitions for options.
     94  */
     95 #define	IPOPT_COPIED(o)		((o)&0x80)
     96 #define	IPOPT_CLASS(o)		((o)&0x60)
     97 #define	IPOPT_NUMBER(o)		((o)&0x1f)
     98 
     99 #define	IPOPT_CONTROL		0x00
    100 #define	IPOPT_RESERVED1		0x20
    101 #define	IPOPT_DEBMEAS		0x40
    102 #define	IPOPT_RESERVED2		0x60
    103 
    104 #define	IPOPT_EOL		0		/* end of option list */
    105 #define	IPOPT_NOP		1		/* no operation */
    106 
    107 #define	IPOPT_RR		7		/* record packet route */
    108 #define	IPOPT_TS		68		/* timestamp */
    109 #define	IPOPT_SECURITY		130		/* provide s,c,h,tcc */
    110 #define	IPOPT_LSRR		131		/* loose source route */
    111 #define	IPOPT_SATID		136		/* satnet id */
    112 #define	IPOPT_SSRR		137		/* strict source route */
    113 
    114 /*
    115  * Offsets to fields in options other than EOL and NOP.
    116  */
    117 #define	IPOPT_OPTVAL		0		/* option ID */
    118 #define	IPOPT_OLEN		1		/* option length */
    119 #define	IPOPT_OFFSET		2		/* offset within option */
    120 #define	IPOPT_MINOFF		4		/* min value of above */
    121 
    122 /*
    123  * Time stamp option structure.
    124  */
    125 struct	ip_timestamp {
    126 	u_int8_t ipt_code;		/* IPOPT_TS */
    127 	u_int8_t ipt_len;		/* size of structure (variable) */
    128 	u_int8_t ipt_ptr;		/* index of current entry */
    129 #if BYTE_ORDER == LITTLE_ENDIAN
    130 	u_int8_t ipt_flg:4,		/* flags, see below */
    131 		 ipt_oflw:4;		/* overflow counter */
    132 #endif
    133 #if BYTE_ORDER == BIG_ENDIAN
    134 	u_int8_t ipt_oflw:4,		/* overflow counter */
    135 		 ipt_flg:4;		/* flags, see below */
    136 #endif
    137 	union ipt_timestamp {
    138 		 n_time	ipt_time[1];
    139 		 struct	ipt_ta {
    140 			struct in_addr ipt_addr;
    141 			n_time ipt_time;
    142 		 } ipt_ta[1];
    143 	} ipt_timestamp;
    144 };
    145 
    146 /* flag bits for ipt_flg */
    147 #define	IPOPT_TS_TSONLY		0		/* timestamps only */
    148 #define	IPOPT_TS_TSANDADDR	1		/* timestamps and addresses */
    149 #define	IPOPT_TS_PRESPEC	3		/* specified modules only */
    150 
    151 /* bits for security (not byte swapped) */
    152 #define	IPOPT_SECUR_UNCLASS	0x0000
    153 #define	IPOPT_SECUR_CONFID	0xf135
    154 #define	IPOPT_SECUR_EFTO	0x789a
    155 #define	IPOPT_SECUR_MMMM	0xbc4d
    156 #define	IPOPT_SECUR_RESTR	0xaf13
    157 #define	IPOPT_SECUR_SECRET	0xd788
    158 #define	IPOPT_SECUR_TOPSECRET	0x6bc5
    159 
    160 /*
    161  * Internet implementation parameters.
    162  */
    163 #define	MAXTTL		255		/* maximum time to live (seconds) */
    164 #define	IPDEFTTL	64		/* default ttl, from RFC 1340 */
    165 #define	IPFRAGTTL	60		/* time to live for frags, slowhz */
    166 #define	IPTTLDEC	1		/* subtracted when forwarding */
    167 
    168 #define	IP_MSS		576		/* default maximum segment size */
    169