xref: /netbsd-src/sys/netinet/ip.h (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
1 /*	$NetBSD: ip.h,v 1.31 2007/12/25 18:33:46 perry 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 	unsigned int ip_hl:4,		/* header length */
49 		     ip_v:4;		/* version */
50 #endif
51 #if BYTE_ORDER == BIG_ENDIAN
52 	unsigned int 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 } __packed;
69 
70 #define	IP_MAXPACKET	65535		/* maximum packet size */
71 #define	IP_MINFRAGSIZE	69		/* minumum size that can be fraged */
72 
73 /*
74  * Definitions for IP type of service (ip_tos)
75  */
76 #define	IPTOS_LOWDELAY		0x10
77 #define	IPTOS_THROUGHPUT	0x08
78 #define	IPTOS_RELIABILITY	0x04
79 /*	IPTOS_LOWCOST		0x02 XXX */
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		0x00
92 
93 /*
94  * ECN (Explicit Congestion Notification) codepoints in RFC3168
95  * mapped to the lower 2 bits of the TOS field.
96  */
97 #define	IPTOS_ECN_NOTECT	0x00	/* not-ECT */
98 #define	IPTOS_ECN_ECT1		0x01	/* ECN-capable transport (1) */
99 #define	IPTOS_ECN_ECT0		0x02	/* ECN-capable transport (0) */
100 #define	IPTOS_ECN_CE		0x03	/* congestion experienced */
101 #define	IPTOS_ECN_MASK		0x03	/* ECN field mask */
102 
103 /*
104  * Definitions for options.
105  */
106 #define	IPOPT_COPIED(o)		((o)&0x80)
107 #define	IPOPT_CLASS(o)		((o)&0x60)
108 #define	IPOPT_NUMBER(o)		((o)&0x1f)
109 
110 #define	IPOPT_CONTROL		0x00
111 #define	IPOPT_RESERVED1		0x20
112 #define	IPOPT_DEBMEAS		0x40
113 #define	IPOPT_RESERVED2		0x60
114 
115 #define	IPOPT_EOL		0		/* end of option list */
116 #define	IPOPT_NOP		1		/* no operation */
117 
118 #define	IPOPT_RR		7		/* record packet route */
119 #define	IPOPT_TS		68		/* timestamp */
120 #define	IPOPT_SECURITY		130		/* provide s,c,h,tcc */
121 #define	IPOPT_LSRR		131		/* loose source route */
122 #define	IPOPT_SATID		136		/* satnet id */
123 #define	IPOPT_SSRR		137		/* strict source route */
124 
125 /*
126  * Offsets to fields in options other than EOL and NOP.
127  */
128 #define	IPOPT_OPTVAL		0		/* option ID */
129 #define	IPOPT_OLEN		1		/* option length */
130 #define	IPOPT_OFFSET		2		/* offset within option */
131 #define	IPOPT_MINOFF		4		/* min value of above */
132 
133 /*
134  * Time stamp option structure.
135  */
136 struct	ip_timestamp {
137 	u_int8_t ipt_code;		/* IPOPT_TS */
138 	u_int8_t ipt_len;		/* size of structure (variable) */
139 	u_int8_t ipt_ptr;		/* index of current entry */
140 #if BYTE_ORDER == LITTLE_ENDIAN
141 	unsigned int ipt_flg:4,		/* flags, see below */
142 		     ipt_oflw:4;	/* overflow counter */
143 #endif
144 #if BYTE_ORDER == BIG_ENDIAN
145 	unsigned int ipt_oflw:4,	/* overflow counter */
146 		     ipt_flg:4;		/* flags, see below */
147 #endif
148 	union ipt_timestamp {
149 		 n_time	ipt_time[1];
150 		 struct	ipt_ta {
151 			struct in_addr ipt_addr;
152 			n_time ipt_time;
153 		 } ipt_ta[1] __packed;
154 	} ipt_timestamp __packed;
155 } __packed;
156 
157 /* flag bits for ipt_flg */
158 #define	IPOPT_TS_TSONLY		0		/* timestamps only */
159 #define	IPOPT_TS_TSANDADDR	1		/* timestamps and addresses */
160 #define	IPOPT_TS_PRESPEC	3		/* specified modules only */
161 
162 /* bits for security (not byte swapped) */
163 #define	IPOPT_SECUR_UNCLASS	0x0000
164 #define	IPOPT_SECUR_CONFID	0xf135
165 #define	IPOPT_SECUR_EFTO	0x789a
166 #define	IPOPT_SECUR_MMMM	0xbc4d
167 #define	IPOPT_SECUR_RESTR	0xaf13
168 #define	IPOPT_SECUR_SECRET	0xd788
169 #define	IPOPT_SECUR_TOPSECRET	0x6bc5
170 
171 /*
172  * Internet implementation parameters.
173  */
174 #define	MAXTTL		255		/* maximum time to live (seconds) */
175 #define	IPDEFTTL	64		/* default ttl, from RFC 1340 */
176 #define	IPFRAGTTL	60		/* time to live for frags, slowhz */
177 #define	IPTTLDEC	1		/* subtracted when forwarding */
178 
179 #define	IP_MSS		576		/* default maximum segment size */
180 
181 /*
182  * This is the real IPv4 pseudo header, used for computing the TCP and UDP
183  * checksums. For the Internet checksum, struct ipovly can be used instead.
184  * For stronger checksums, the real thing must be used.
185  */
186 struct ippseudo {
187 	struct	in_addr	ippseudo_src;	/* source internet address */
188 	struct	in_addr	ippseudo_dst;	/* destination internet address */
189 	u_int8_t	ippseudo_pad;	/* pad, must be zero */
190 	u_int8_t	ippseudo_p;	/* protocol */
191 	u_int16_t	ippseudo_len;	/* protocol length */
192 } __packed;
193 #endif /* !_NETINET_IP_H_ */
194 
195