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      1 /*	$NetBSD: ip.h,v 1.2 2018/04/07 22:37:30 christos Exp $	*/
      2 
      3 /*	NetBSD: ip.h,v 1.9 1995/05/15 01:22:44 cgd Exp 	*/
      4 
      5 /*
      6  * Copyright (c) 1982, 1986, 1993
      7  *	The Regents of the University of California.  All rights reserved.
      8  *
      9  * Redistribution and use in source and binary forms, with or without
     10  * modification, are permitted provided that the following conditions
     11  * are met:
     12  * 1. Redistributions of source code must retain the above copyright
     13  *    notice, this list of conditions and the following disclaimer.
     14  * 2. Redistributions in binary form must reproduce the above copyright
     15  *    notice, this list of conditions and the following disclaimer in the
     16  *    documentation and/or other materials provided with the distribution.
     17  * 3. Neither the name of the University nor the names of its contributors
     18  *    may be used to endorse or promote products derived from this software
     19  *    without specific prior written permission.
     20  *
     21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     31  * SUCH DAMAGE.
     32  *
     33  *	@(#)ip.h	8.1 (Berkeley) 6/10/93
     34  */
     35 
     36 /*
     37  * Definitions for internet protocol version 4.
     38  * Per RFC 791, September 1981.
     39  */
     40 #define	IPVERSION	4
     41 
     42 /*
     43  * Structure of an internet header, naked of options.
     44  *
     45  * We declare ip_len and ip_off to be short, rather than u_short
     46  * pragmatically since otherwise unsigned comparisons can result
     47  * against negative integers quite easily, and fail in subtle ways.
     48  */
     49 struct ip {
     50 	u_int8_t  ip_fvhl;		/* header length, version */
     51 	u_int8_t  ip_tos;		/* type of service */
     52 	int16_t	  ip_len;		/* total length */
     53 	u_int16_t ip_id;		/* identification */
     54 	int16_t	  ip_off;		/* fragment offset field */
     55 #define	IP_DF 0x4000			/* dont fragment flag */
     56 #define	IP_MF 0x2000			/* more fragments flag */
     57 #define	IP_OFFMASK 0x1fff		/* mask for fragmenting bits */
     58 	u_int8_t  ip_ttl;		/* time to live */
     59 	u_int8_t  ip_p;			/* protocol */
     60 	u_int16_t ip_sum;		/* checksum */
     61 	struct	  in_addr ip_src, ip_dst; /* source and dest address */
     62 };
     63 
     64 #define IP_V(iph)	((iph)->ip_fvhl >> 4)
     65 #define IP_HL(iph)	(((iph)->ip_fvhl & 0x0F) << 2)
     66 #define IP_V_SET(iph,x)	((iph)->ip_fvhl = ((iph)->ip_fvhl & 0x0F) | ((x) << 4))
     67 #define IP_HL_SET(iph,x) ((iph)->ip_fvhl = \
     68 			  ((iph)->ip_fvhl & 0xF0) | (((x) >> 2) & 0x0F))
     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 	u_int8_t ipt_flg_oflw;		/* flags, see below, overflow counter */
    130 	union ipt_timestamp {
    131 		 u_int32_t ipt_time[1];
    132 		 struct	ipt_ta {
    133 			struct in_addr ipt_addr;
    134 			u_int32_t ipt_time;
    135 		 } ipt_ta[1];
    136 	} ipt_timestamp;
    137 };
    138 
    139 /* flag bits for ipt_flg */
    140 #define	IPOPT_TS_TSONLY		0		/* timestamps only */
    141 #define	IPOPT_TS_TSANDADDR	1		/* timestamps and addresses */
    142 #define	IPOPT_TS_PRESPEC	3		/* specified modules only */
    143 
    144 /* bits for security (not byte swapped) */
    145 #define	IPOPT_SECUR_UNCLASS	0x0000
    146 #define	IPOPT_SECUR_CONFID	0xf135
    147 #define	IPOPT_SECUR_EFTO	0x789a
    148 #define	IPOPT_SECUR_MMMM	0xbc4d
    149 #define	IPOPT_SECUR_RESTR	0xaf13
    150 #define	IPOPT_SECUR_SECRET	0xd788
    151 #define	IPOPT_SECUR_TOPSECRET	0x6bc5
    152 
    153 /*
    154  * Internet implementation parameters.
    155  */
    156 #define	MAXTTL		255		/* maximum time to live (seconds) */
    157 #define	IPDEFTTL	64		/* default ttl, from RFC 1340 */
    158 #define	IPFRAGTTL	60		/* time to live for frags, slowhz */
    159 #define	IPTTLDEC	1		/* subtracted when forwarding */
    160 
    161 #define	IP_MSS		576		/* default maximum segment size */
    162