1/* $OpenBSD: ip.h,v 1.22 2025/12/19 13:58:53 tb Exp $ */
2/* $NetBSD: ip.h,v 1.9 1995/05/15 01:22:44 cgd Exp $ */
3
4/*
5 * Copyright (c) 1982, 1986, 1993
6 * The Regents of the University of California. All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 *
32 * @(#)ip.h 8.1 (Berkeley) 6/10/93
33 */
34
35#ifndef _NETINET_IP_H_
36#define _NETINET_IP_H_
37
38/*
39 * Definitions for internet protocol version 4.
40 * Per RFC 791, September 1981.
41 */
42#define IPVERSION 4
43
44/*
45 * Structure of an internet header, naked of options.
46 */
47struct ip {
48#if _BYTE_ORDER == _LITTLE_ENDIAN
49 u_int ip_hl:4, /* header length */
50 ip_v:4; /* version */
51#endif
52#if _BYTE_ORDER == _BIG_ENDIAN
53 u_int ip_v:4, /* version */
54 ip_hl:4; /* header length */
55#endif
56 u_int8_t ip_tos; /* type of service */
57 u_int16_t ip_len; /* total length */
58 u_int16_t ip_id; /* identification */
59 u_int16_t ip_off; /* fragment offset field */
60#define IP_RF 0x8000 /* reserved fragment flag */
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};
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 * Definitions for DiffServ Codepoints as per RFCs 2474, 3246, 4594, 5865, 8622.
99 * These are the 6 most significant bits as they appear on the wire, so the
100 * two least significant bits must be zero.
101 */
102#define IPTOS_DSCP_CS0 0x00
103#define IPTOS_DSCP_LE 0x04
104#define IPTOS_DSCP_CS1 0x20
105#define IPTOS_DSCP_AF11 0x28
106#define IPTOS_DSCP_AF12 0x30
107#define IPTOS_DSCP_AF13 0x38
108#define IPTOS_DSCP_CS2 0x40
109#define IPTOS_DSCP_AF21 0x48
110#define IPTOS_DSCP_AF22 0x50
111#define IPTOS_DSCP_AF23 0x58
112#define IPTOS_DSCP_CS3 0x60
113#define IPTOS_DSCP_AF31 0x68
114#define IPTOS_DSCP_AF32 0x70
115#define IPTOS_DSCP_AF33 0x78
116#define IPTOS_DSCP_CS4 0x80
117#define IPTOS_DSCP_AF41 0x88
118#define IPTOS_DSCP_AF42 0x90
119#define IPTOS_DSCP_AF43 0x98
120#define IPTOS_DSCP_CS5 0xa0
121#define IPTOS_DSCP_VA 0xb0
122#define IPTOS_DSCP_EF 0xb8
123#define IPTOS_DSCP_CS6 0xc0
124#define IPTOS_DSCP_CS7 0xe0
125
126/*
127 * ECN (Explicit Congestion Notification) codepoints in RFC3168
128 * mapped to the lower 2 bits of the TOS field.
129 */
130#define IPTOS_ECN_NOTECT 0x00 /* not-ECT */
131#define IPTOS_ECN_ECT1 0x01 /* ECN-capable transport (1) */
132#define IPTOS_ECN_ECT0 0x02 /* ECN-capable transport (0) */
133#define IPTOS_ECN_CE 0x03 /* congestion experienced */
134#define IPTOS_ECN_MASK 0x03 /* ECN field mask */
135
136/*
137 * Definitions for options.
138 */
139#define IPOPT_COPIED(o) ((o)&0x80)
140#define IPOPT_CLASS(o) ((o)&0x60)
141#define IPOPT_NUMBER(o) ((o)&0x1f)
142
143#define IPOPT_CONTROL 0x00
144#define IPOPT_RESERVED1 0x20
145#define IPOPT_DEBMEAS 0x40
146#define IPOPT_RESERVED2 0x60
147
148#define IPOPT_EOL 0 /* end of option list */
149#define IPOPT_NOP 1 /* no operation */
150
151#define IPOPT_RR 7 /* record packet route */
152#define IPOPT_TS 68 /* timestamp */
153#define IPOPT_SECURITY 130 /* provide s,c,h,tcc */
154#define IPOPT_LSRR 131 /* loose source route */
155#define IPOPT_SATID 136 /* satnet id */
156#define IPOPT_SSRR 137 /* strict source route */
157#define IPOPT_RA 148 /* router alert */
158
159/*
160 * Offsets to fields in options other than EOL and NOP.
161 */
162#define IPOPT_OPTVAL 0 /* option ID */
163#define IPOPT_OLEN 1 /* option length */
164#define IPOPT_OFFSET 2 /* offset within option */
165#define IPOPT_MINOFF 4 /* min value of above */
166
167/*
168 * Time stamp option structure.
169 */
170struct ip_timestamp {
171 u_int8_t ipt_code; /* IPOPT_TS */
172 u_int8_t ipt_len; /* size of structure (variable) */
173 u_int8_t ipt_ptr; /* index of current entry */
174#if _BYTE_ORDER == _LITTLE_ENDIAN
175 u_int ipt_flg:4, /* flags, see below */
176 ipt_oflw:4; /* overflow counter */
177#endif
178#if _BYTE_ORDER == _BIG_ENDIAN
179 u_int ipt_oflw:4, /* overflow counter */
180 ipt_flg:4; /* flags, see below */
181#endif
182 union ipt_timestamp {
183 u_int32_t ipt_time[1];
184 struct ipt_ta {
185 struct in_addr ipt_addr;
186 u_int32_t ipt_time;
187 } ipt_ta[1];
188 } ipt_timestamp;
189};
190
191/* flag bits for ipt_flg */
192#define IPOPT_TS_TSONLY 0 /* timestamps only */
193#define IPOPT_TS_TSANDADDR 1 /* timestamps and addresses */
194#define IPOPT_TS_PRESPEC 3 /* specified modules only */
195
196/* bits for security (not byte swapped) */
197#define IPOPT_SECUR_UNCLASS 0x0000
198#define IPOPT_SECUR_CONFID 0xf135
199#define IPOPT_SECUR_EFTO 0x789a
200#define IPOPT_SECUR_MMMM 0xbc4d
201#define IPOPT_SECUR_RESTR 0xaf13
202#define IPOPT_SECUR_SECRET 0xd788
203#define IPOPT_SECUR_TOPSECRET 0x6bc5
204
205/*
206 * Internet implementation parameters.
207 */
208#define MAXTTL 255 /* maximum time to live (seconds) */
209#define IPDEFTTL 64 /* default ttl, from RFC 1340 */
210#define IPFRAGTTL 60 /* time to live for frags, slowhz */
211#define IPTTLDEC 1 /* subtracted when forwarding */
212
213#define IP_MSS 576 /* default maximum segment size */
214
215#ifdef _KERNEL
216
217/* Maximum length for IP protocol queues */
218#define IPQ_MAXLEN 2048
219
220/*
221 * This is the real IPv4 pseudo header, used for computing the TCP and UDP
222 * checksums. For the Internet checksum, struct ipovly can be used instead.
223 * For stronger checksums, the real thing must be used.
224 */
225struct ippseudo {
226 struct in_addr ippseudo_src; /* source internet address */
227 struct in_addr ippseudo_dst; /* destination internet address */
228 u_int8_t ippseudo_pad; /* pad, must be zero */
229 u_int8_t ippseudo_p; /* protocol */
230 u_int16_t ippseudo_len; /* protocol length */
231};
232#endif /* _KERNEL */
233
234#endif /* _NETINET_IP_H_ */