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ip.h revision 1.26
      1 /*	$NetBSD: ip.h,v 1.26 2004/04/25 22:25:03 jonathan 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. Neither the name of the University nor the names of its contributors
     16  *    may be used to endorse or promote products derived from this software
     17  *    without specific prior written permission.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     29  * SUCH DAMAGE.
     30  *
     31  *	@(#)ip.h	8.2 (Berkeley) 6/1/94
     32  */
     33 
     34 #ifndef _NETINET_IP_H_
     35 #define _NETINET_IP_H_
     36 
     37 /*
     38  * Definitions for internet protocol version 4.
     39  * Per RFC 791, September 1981.
     40  */
     41 #define	IPVERSION	4
     42 
     43 /*
     44  * Structure of an internet header, naked of options.
     45  */
     46 struct ip {
     47 #if BYTE_ORDER == LITTLE_ENDIAN
     48 	u_int8_t  ip_hl:4,		/* header length */
     49 		  ip_v:4;		/* version */
     50 #endif
     51 #if BYTE_ORDER == BIG_ENDIAN
     52 	u_int8_t  ip_v:4,		/* version */
     53 		  ip_hl:4;		/* header length */
     54 #endif
     55 	u_int8_t  ip_tos;		/* type of service */
     56 	u_int16_t ip_len;		/* total length */
     57 	u_int16_t ip_id;		/* identification */
     58 	u_int16_t ip_off;		/* fragment offset field */
     59 #define	IP_RF 0x8000			/* reserved fragment flag */
     60 #define	IP_EF 0x8000			/* evil flag, per RFC 3514 */
     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 } __attribute__((__packed__));
     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 #if 1
     80 /* ECN RFC3168 obsoletes RFC2481, and these will be deprecated soon. */
     81 #define IPTOS_CE		0x01	/* congestion experienced */
     82 #define IPTOS_ECT		0x02	/* ECN-capable transport */
     83 #endif
     84 
     85 /*
     86  * Definitions for IP precedence (also in ip_tos) (hopefully unused)
     87  */
     88 #define	IPTOS_PREC_NETCONTROL		0xe0
     89 #define	IPTOS_PREC_INTERNETCONTROL	0xc0
     90 #define	IPTOS_PREC_CRITIC_ECP		0xa0
     91 #define	IPTOS_PREC_FLASHOVERRIDE	0x80
     92 #define	IPTOS_PREC_FLASH		0x60
     93 #define	IPTOS_PREC_IMMEDIATE		0x40
     94 #define	IPTOS_PREC_PRIORITY		0x20
     95 #define	IPTOS_PREC_ROUTINE		0x00
     96 
     97 /*
     98  * ECN (Explicit Congestion Notification) codepoints in RFC3168
     99  * mapped to the lower 2 bits of the TOS field.
    100  */
    101 #define	IPTOS_ECN_NOTECT	0x00	/* not-ECT */
    102 #define	IPTOS_ECN_ECT1		0x01	/* ECN-capable transport (1) */
    103 #define	IPTOS_ECN_ECT0		0x02	/* ECN-capable transport (0) */
    104 #define	IPTOS_ECN_CE		0x03	/* congestion experienced */
    105 #define	IPTOS_ECN_MASK		0x03	/* ECN field mask */
    106 
    107 /*
    108  * Definitions for options.
    109  */
    110 #define	IPOPT_COPIED(o)		((o)&0x80)
    111 #define	IPOPT_CLASS(o)		((o)&0x60)
    112 #define	IPOPT_NUMBER(o)		((o)&0x1f)
    113 
    114 #define	IPOPT_CONTROL		0x00
    115 #define	IPOPT_RESERVED1		0x20
    116 #define	IPOPT_DEBMEAS		0x40
    117 #define	IPOPT_RESERVED2		0x60
    118 
    119 #define	IPOPT_EOL		0		/* end of option list */
    120 #define	IPOPT_NOP		1		/* no operation */
    121 
    122 #define	IPOPT_RR		7		/* record packet route */
    123 #define	IPOPT_TS		68		/* timestamp */
    124 #define	IPOPT_SECURITY		130		/* provide s,c,h,tcc */
    125 #define	IPOPT_LSRR		131		/* loose source route */
    126 #define	IPOPT_SATID		136		/* satnet id */
    127 #define	IPOPT_SSRR		137		/* strict source route */
    128 
    129 /*
    130  * Offsets to fields in options other than EOL and NOP.
    131  */
    132 #define	IPOPT_OPTVAL		0		/* option ID */
    133 #define	IPOPT_OLEN		1		/* option length */
    134 #define	IPOPT_OFFSET		2		/* offset within option */
    135 #define	IPOPT_MINOFF		4		/* min value of above */
    136 
    137 /*
    138  * Time stamp option structure.
    139  */
    140 struct	ip_timestamp {
    141 	u_int8_t ipt_code;		/* IPOPT_TS */
    142 	u_int8_t ipt_len;		/* size of structure (variable) */
    143 	u_int8_t ipt_ptr;		/* index of current entry */
    144 #if BYTE_ORDER == LITTLE_ENDIAN
    145 	u_int8_t ipt_flg:4,		/* flags, see below */
    146 		 ipt_oflw:4;		/* overflow counter */
    147 #endif
    148 #if BYTE_ORDER == BIG_ENDIAN
    149 	u_int8_t ipt_oflw:4,		/* overflow counter */
    150 		 ipt_flg:4;		/* flags, see below */
    151 #endif
    152 	union ipt_timestamp {
    153 		 n_time	ipt_time[1];
    154 		 struct	ipt_ta {
    155 			struct in_addr ipt_addr;
    156 			n_time ipt_time;
    157 		 } ipt_ta[1] __attribute__((__packed__));
    158 	} ipt_timestamp __attribute__((__packed__));
    159 } __attribute__((__packed__));
    160 
    161 /* flag bits for ipt_flg */
    162 #define	IPOPT_TS_TSONLY		0		/* timestamps only */
    163 #define	IPOPT_TS_TSANDADDR	1		/* timestamps and addresses */
    164 #define	IPOPT_TS_PRESPEC	3		/* specified modules only */
    165 
    166 /* bits for security (not byte swapped) */
    167 #define	IPOPT_SECUR_UNCLASS	0x0000
    168 #define	IPOPT_SECUR_CONFID	0xf135
    169 #define	IPOPT_SECUR_EFTO	0x789a
    170 #define	IPOPT_SECUR_MMMM	0xbc4d
    171 #define	IPOPT_SECUR_RESTR	0xaf13
    172 #define	IPOPT_SECUR_SECRET	0xd788
    173 #define	IPOPT_SECUR_TOPSECRET	0x6bc5
    174 
    175 /*
    176  * Internet implementation parameters.
    177  */
    178 #define	MAXTTL		255		/* maximum time to live (seconds) */
    179 #define	IPDEFTTL	64		/* default ttl, from RFC 1340 */
    180 #define	IPFRAGTTL	60		/* time to live for frags, slowhz */
    181 #define	IPTTLDEC	1		/* subtracted when forwarding */
    182 
    183 #define	IP_MSS		576		/* default maximum segment size */
    184 
    185 /*
    186  * This is the real IPv4 pseudo header, used for computing the TCP and UDP
    187  * checksums. For the Internet checksum, struct ipovly can be used instead.
    188  * For stronger checksums, the real thing must be used.
    189  */
    190 struct ippseudo {
    191 	struct	in_addr	ippseudo_src;	/* source internet address */
    192 	struct	in_addr	ippseudo_dst;	/* destination internet address */
    193 	u_int8_t	ippseudo_pad;	/* pad, must be zero */
    194 	u_int8_t	ippseudo_p;	/* protocol */
    195 	u_int16_t	ippseudo_len;	/* protocol length */
    196 } __packed;
    197 #endif /* _NETINET_IP_H_ */
    198