xref: /netbsd-src/sys/netinet/ip.h (revision ae1bfcddc410612bc8c58b807e1830becb69a24c)
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  *	from: @(#)ip.h	8.1 (Berkeley) 6/10/93
34  *	$Id: ip.h,v 1.5 1994/05/13 06:06:16 mycroft Exp $
35  */
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  * We declare ip_len and ip_off to be short, rather than u_short
47  * pragmatically since otherwise unsigned comparisons can result
48  * against negative integers quite easily, and fail in subtle ways.
49  */
50 struct ip {
51 #if BYTE_ORDER == LITTLE_ENDIAN
52 	u_char	ip_hl:4,		/* header length */
53 		ip_v:4;			/* version */
54 #endif
55 #if BYTE_ORDER == BIG_ENDIAN
56 	u_char	ip_v:4,			/* version */
57 		ip_hl:4;		/* header length */
58 #endif
59 	u_char	ip_tos;			/* type of service */
60 	short	ip_len;			/* total length */
61 	u_short	ip_id;			/* identification */
62 	short	ip_off;			/* fragment offset field */
63 #define	IP_DF 0x4000			/* dont fragment flag */
64 #define	IP_MF 0x2000			/* more fragments flag */
65 #define	IP_OFFMASK 0x1fff		/* mask for fragmenting bits */
66 	u_char	ip_ttl;			/* time to live */
67 	u_char	ip_p;			/* protocol */
68 	u_short	ip_sum;			/* checksum */
69 	struct	in_addr ip_src,ip_dst;	/* source and dest address */
70 };
71 
72 #define	IP_MAXPACKET	65535		/* maximum packet size */
73 
74 /*
75  * Definitions for IP type of service (ip_tos)
76  */
77 #define	IPTOS_LOWDELAY		0x10
78 #define	IPTOS_THROUGHPUT	0x08
79 #define	IPTOS_RELIABILITY	0x04
80 
81 /*
82  * Definitions for IP precedence (also in ip_tos) (hopefully unused)
83  */
84 #define	IPTOS_PREC_NETCONTROL		0xe0
85 #define	IPTOS_PREC_INTERNETCONTROL	0xc0
86 #define	IPTOS_PREC_CRITIC_ECP		0xa0
87 #define	IPTOS_PREC_FLASHOVERRIDE	0x80
88 #define	IPTOS_PREC_FLASH		0x60
89 #define	IPTOS_PREC_IMMEDIATE		0x40
90 #define	IPTOS_PREC_PRIORITY		0x20
91 #define	IPTOS_PREC_ROUTINE		0x10
92 
93 /*
94  * Definitions for options.
95  */
96 #define	IPOPT_COPIED(o)		((o)&0x80)
97 #define	IPOPT_CLASS(o)		((o)&0x60)
98 #define	IPOPT_NUMBER(o)		((o)&0x1f)
99 
100 #define	IPOPT_CONTROL		0x00
101 #define	IPOPT_RESERVED1		0x20
102 #define	IPOPT_DEBMEAS		0x40
103 #define	IPOPT_RESERVED2		0x60
104 
105 #define	IPOPT_EOL		0		/* end of option list */
106 #define	IPOPT_NOP		1		/* no operation */
107 
108 #define	IPOPT_RR		7		/* record packet route */
109 #define	IPOPT_TS		68		/* timestamp */
110 #define	IPOPT_SECURITY		130		/* provide s,c,h,tcc */
111 #define	IPOPT_LSRR		131		/* loose source route */
112 #define	IPOPT_SATID		136		/* satnet id */
113 #define	IPOPT_SSRR		137		/* strict source route */
114 
115 /*
116  * Offsets to fields in options other than EOL and NOP.
117  */
118 #define	IPOPT_OPTVAL		0		/* option ID */
119 #define	IPOPT_OLEN		1		/* option length */
120 #define	IPOPT_OFFSET		2		/* offset within option */
121 #define	IPOPT_MINOFF		4		/* min value of above */
122 
123 /*
124  * Time stamp option structure.
125  */
126 struct	ip_timestamp {
127 	u_char	ipt_code;		/* IPOPT_TS */
128 	u_char	ipt_len;		/* size of structure (variable) */
129 	u_char	ipt_ptr;		/* index of current entry */
130 #if BYTE_ORDER == LITTLE_ENDIAN
131 	u_char	ipt_flg:4,		/* flags, see below */
132 		ipt_oflw:4;		/* overflow counter */
133 #endif
134 #if BYTE_ORDER == BIG_ENDIAN
135 	u_char	ipt_oflw:4,		/* overflow counter */
136 		ipt_flg:4;		/* flags, see below */
137 #endif
138 	union ipt_timestamp {
139 		n_long	ipt_time[1];
140 		struct	ipt_ta {
141 			struct in_addr ipt_addr;
142 			n_long ipt_time;
143 		} ipt_ta[1];
144 	} ipt_timestamp;
145 };
146 
147 /* flag bits for ipt_flg */
148 #define	IPOPT_TS_TSONLY		0		/* timestamps only */
149 #define	IPOPT_TS_TSANDADDR	1		/* timestamps and addresses */
150 #define	IPOPT_TS_PRESPEC	3		/* specified modules only */
151 
152 /* bits for security (not byte swapped) */
153 #define	IPOPT_SECUR_UNCLASS	0x0000
154 #define	IPOPT_SECUR_CONFID	0xf135
155 #define	IPOPT_SECUR_EFTO	0x789a
156 #define	IPOPT_SECUR_MMMM	0xbc4d
157 #define	IPOPT_SECUR_RESTR	0xaf13
158 #define	IPOPT_SECUR_SECRET	0xd788
159 #define	IPOPT_SECUR_TOPSECRET	0x6bc5
160 
161 /*
162  * Internet implementation parameters.
163  */
164 #define	MAXTTL		255		/* maximum time to live (seconds) */
165 #define	IPDEFTTL	64		/* default ttl, from RFC 1340 */
166 #define	IPFRAGTTL	60		/* time to live for frags, slowhz */
167 #define	IPTTLDEC	1		/* subtracted when forwarding */
168 
169 #define	IP_MSS		576		/* default maximum segment size */
170