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      1 /*
      2  * Copyright (c) 1982, 1986, 1993
      3  *	The Regents of the University of California.  All rights reserved.
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions
      7  * are met:
      8  * 1. Redistributions of source code must retain the above copyright
      9  *    notice, this list of conditions and the following disclaimer.
     10  * 2. Redistributions in binary form must reproduce the above copyright
     11  *    notice, this list of conditions and the following disclaimer in the
     12  *    documentation and/or other materials provided with the distribution.
     13  * 3. All advertising materials mentioning features or use of this software
     14  *    must display the following acknowledgement:
     15  *	This product includes software developed by the University of
     16  *	California, Berkeley and its contributors.
     17  * 4. 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	8.2 (Berkeley) 6/1/94
     34  */
     35 
     36 #ifndef netdissect_ip_h
     37 #define netdissect_ip_h
     38 
     39 /*
     40  * Definitions for internet protocol version 4.
     41  * Per RFC 791, September 1981.
     42  */
     43 #define	IPVERSION	4
     44 
     45 /*
     46  * Structure of an internet header, naked of options.
     47  *
     48  * We declare ip_len and ip_off to be short, rather than u_short
     49  * pragmatically since otherwise unsigned comparisons can result
     50  * against negative integers quite easily, and fail in subtle ways.
     51  */
     52 struct ip {
     53 	nd_uint8_t	ip_vhl;		/* header length, version */
     54 #define IP_V(ip)	(((ip)->ip_vhl & 0xf0) >> 4)
     55 #define IP_HL(ip)	((ip)->ip_vhl & 0x0f)
     56 	nd_uint8_t	ip_tos;		/* type of service */
     57 	nd_uint16_t	ip_len;		/* total length */
     58 	nd_uint16_t	ip_id;		/* identification */
     59 	nd_uint16_t	ip_off;		/* fragment offset field */
     60 #define	IP_DF 0x4000			/* dont fragment flag */
     61 #define	IP_MF 0x2000			/* more fragments flag */
     62 #define	IP_OFFMASK 0x1fff		/* mask for fragmenting bits */
     63 	nd_uint8_t	ip_ttl;		/* time to live */
     64 	nd_uint8_t	ip_p;		/* protocol */
     65 	nd_uint16_t	ip_sum;		/* checksum */
     66 	nd_ipv4		ip_src,ip_dst;	/* source and dest address */
     67 };
     68 
     69 #define	IP_MAXPACKET	65535		/* maximum packet size */
     70 
     71 /*
     72  * Definitions for IP type of service (ip_tos)
     73  */
     74 #define	IPTOS_LOWDELAY		0x10
     75 #define	IPTOS_THROUGHPUT	0x08
     76 #define	IPTOS_RELIABILITY	0x04
     77 
     78 /*
     79  * Definitions for IP precedence (also in ip_tos) (hopefully unused)
     80  */
     81 #define	IPTOS_PREC_NETCONTROL		0xe0
     82 #define	IPTOS_PREC_INTERNETCONTROL	0xc0
     83 #define	IPTOS_PREC_CRITIC_ECP		0xa0
     84 #define	IPTOS_PREC_FLASHOVERRIDE	0x80
     85 #define	IPTOS_PREC_FLASH		0x60
     86 #define	IPTOS_PREC_IMMEDIATE		0x40
     87 #define	IPTOS_PREC_PRIORITY		0x20
     88 #define	IPTOS_PREC_ROUTINE		0x00
     89 
     90 /*
     91  * Definitions for options.
     92  */
     93 #define	IPOPT_COPIED(o)		((o)&0x80)
     94 #define	IPOPT_CLASS(o)		((o)&0x60)
     95 #define	IPOPT_NUMBER(o)		((o)&0x1f)
     96 
     97 #define	IPOPT_CONTROL		0x00
     98 #define	IPOPT_RESERVED1		0x20
     99 #define	IPOPT_DEBMEAS		0x40
    100 #define	IPOPT_RESERVED2		0x60
    101 
    102 #define	IPOPT_EOL		0		/* end of option list */
    103 #define	IPOPT_NOP		1		/* no operation */
    104 
    105 #define	IPOPT_RR		7		/* record packet route */
    106 #define	IPOPT_TS		68		/* timestamp */
    107 #define	IPOPT_RFC1393           82              /* traceroute RFC 1393 */
    108 #define	IPOPT_SECURITY		130		/* provide s,c,h,tcc */
    109 #define	IPOPT_LSRR		131		/* loose source route */
    110 #define	IPOPT_SATID		136		/* satnet id */
    111 #define	IPOPT_SSRR		137		/* strict source route */
    112 #define IPOPT_RA                148             /* router-alert, rfc2113 */
    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 	nd_uint8_t	ipt_code;	/* IPOPT_TS */
    127 	nd_uint8_t	ipt_len;	/* size of structure (variable) */
    128 	nd_uint8_t	ipt_ptr;	/* index of current entry */
    129 	nd_uint8_t	ipt_oflwflg;	/* flags, overflow counter */
    130 #define IPTS_OFLW(ip)	(((ipt)->ipt_oflwflg & 0xf0) >> 4)
    131 #define IPTS_FLG(ip)	((ipt)->ipt_oflwflg & 0x0f)
    132 	union ipt_timestamp {
    133 		nd_uint32_t ipt_time[1];
    134 		struct	ipt_ta {
    135 			nd_ipv4 ipt_addr;
    136 			nd_uint32_t ipt_time;
    137 		} ipt_ta[1];
    138 	} ipt_timestamp;
    139 };
    140 
    141 /* flag bits for ipt_flg */
    142 #define	IPOPT_TS_TSONLY		0		/* timestamps only */
    143 #define	IPOPT_TS_TSANDADDR	1		/* timestamps and addresses */
    144 #define	IPOPT_TS_PRESPEC	3		/* specified modules only */
    145 
    146 /* bits for security (not byte swapped) */
    147 #define	IPOPT_SECUR_UNCLASS	0x0000
    148 #define	IPOPT_SECUR_CONFID	0xf135
    149 #define	IPOPT_SECUR_EFTO	0x789a
    150 #define	IPOPT_SECUR_MMMM	0xbc4d
    151 #define	IPOPT_SECUR_RESTR	0xaf13
    152 #define	IPOPT_SECUR_SECRET	0xd788
    153 #define	IPOPT_SECUR_TOPSECRET	0x6bc5
    154 
    155 /*
    156  * Internet implementation parameters.
    157  */
    158 #define	MAXTTL		255		/* maximum time to live (seconds) */
    159 #define	IPDEFTTL	64		/* default ttl, from RFC 1340 */
    160 #define	IPFRAGTTL	60		/* time to live for frags, slowhz */
    161 #define	IPTTLDEC	1		/* subtracted when forwarding */
    162 
    163 #define	IP_MSS		576		/* default maximum segment size */
    164 #endif /* netdissect_ip_h */
    165