1/* $NetBSD: ip.h,v 1.39 2022/04/17 21:24:53 andvar 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#include <sys/types.h>
38
39#include <netinet/in.h>
40#include <netinet/in_systm.h> /* for n_time */
41
42/*
43 * Definitions for internet protocol version 4.
44 * Per RFC 791, September 1981.
45 */
46#define IPVERSION 4
47
48/*
49 * Structure of an internet header, naked of options.
50 */
51struct ip {
52#if BYTE_ORDER == LITTLE_ENDIAN
53 unsigned int ip_hl:4, /* header length */
54 ip_v:4; /* version */
55#endif
56#if BYTE_ORDER == BIG_ENDIAN
57 unsigned int ip_v:4, /* version */
58 ip_hl:4; /* header length */
59#endif
60 u_int8_t ip_tos; /* type of service */
61 u_int16_t ip_len; /* total length */
62 u_int16_t ip_id; /* identification */
63 u_int16_t ip_off; /* fragment offset field */
64#define IP_RF 0x8000 /* reserved fragment flag */
65#define IP_EF 0x8000 /* evil flag, per RFC 3514 */
66#define IP_DF 0x4000 /* dont fragment flag */
67#define IP_MF 0x2000 /* more fragments flag */
68#define IP_OFFMASK 0x1fff /* mask for fragmenting bits */
69 u_int8_t ip_ttl; /* time to live */
70 u_int8_t ip_p; /* protocol */
71 u_int16_t ip_sum; /* checksum */
72 struct in_addr ip_src, ip_dst; /* source and dest address */
73};
74
75#define IP_MAXPACKET 65535 /* maximum packet size */
76#define IP_MINFRAGSIZE 69 /* minimum size that can be fraged */
77
78/*
79 * Definitions for IP type of service (ip_tos)
80 */
81
82/*
83 * Definitions for DiffServ Codepoints as per RFC2474
84 */
85#define IPTOS_DSCP_CS0 0x00
86#define IPTOS_DSCP_CS1 0x20
87#define IPTOS_DSCP_AF11 0x28
88#define IPTOS_DSCP_AF12 0x30
89#define IPTOS_DSCP_AF13 0x38
90#define IPTOS_DSCP_CS2 0x40
91#define IPTOS_DSCP_AF21 0x48
92#define IPTOS_DSCP_AF22 0x50
93#define IPTOS_DSCP_AF23 0x58
94#define IPTOS_DSCP_CS3 0x60
95#define IPTOS_DSCP_AF31 0x68
96#define IPTOS_DSCP_AF32 0x70
97#define IPTOS_DSCP_AF33 0x78
98#define IPTOS_DSCP_CS4 0x80
99#define IPTOS_DSCP_AF41 0x88
100#define IPTOS_DSCP_AF42 0x90
101#define IPTOS_DSCP_AF43 0x98
102#define IPTOS_DSCP_CS5 0xa0
103#define IPTOS_DSCP_EF 0xb8
104#define IPTOS_DSCP_CS6 0xc0
105#define IPTOS_DSCP_CS7 0xe0
106
107/*
108 * Definitions for DiffServ Class Selector Codepoints
109 */
110#define IPTOS_CLASS_CS0 0x00
111#define IPTOS_CLASS_CS1 0x20
112#define IPTOS_CLASS_CS2 0x40
113#define IPTOS_CLASS_CS3 0x60
114#define IPTOS_CLASS_CS4 0x80
115#define IPTOS_CLASS_CS5 0xa0
116#define IPTOS_CLASS_CS6 0xc0
117#define IPTOS_CLASS_CS7 0xe0
118#define IPTOS_CLASS_DEFAULT IPTOS_CLASS_CS0
119#define IPTOS_CLASS_MASK 0xe0
120#define IPTOS_CLASS(cs) ((cs) & IPTOS_CLASS_MASK)
121#define IPTOS_DSCP_MASK 0xfc
122#define IPTOS_DSCP(cp) ((cp) & IPTOS_DSCP_MASK)
123
124/*
125 * ECN (Explicit Congestion Notification) codepoints in RFC3168
126 * mapped to the lower 2 bits of the TOS field.
127 */
128#define IPTOS_ECN_NOTECT 0x00 /* not-ECT */
129#define IPTOS_ECN_ECT1 0x01 /* ECN-capable transport (1) */
130#define IPTOS_ECN_ECT0 0x02 /* ECN-capable transport (0) */
131#define IPTOS_ECN_CE 0x03 /* congestion experienced */
132#define IPTOS_ECN_MASK 0x03 /* ECN field mask */
133#define IPTOS_ECN(cn) ((cn) & IPTOS_ECN_MASK)
134#define IPTOS_ECN_NOT_ECT 0x00
135
136/*
137 * Definitions for IP type of service per RFC1349 (ip_tos)
138 * DEPRECATED
139 */
140#define IPTOS_LOWDELAY 0x10
141#define IPTOS_THROUGHPUT 0x08
142#define IPTOS_RELIABILITY 0x04
143#define IPTOS_MINCOST 0x02
144/* ECN RFC3168 obsoletes RFC2481, and these will be deprecated soon. */
145#define IPTOS_CE 0x01 /* congestion experienced */
146#define IPTOS_ECT 0x02 /* ECN-capable transport */
147
148/*
149 * Definitions for IP precedence per RFC1195 (also in ip_tos) (hopefully unused)
150 */
151#define IPTOS_PREC_NETCONTROL 0xe0
152#define IPTOS_PREC_INTERNETCONTROL 0xc0
153#define IPTOS_PREC_CRITIC_ECP 0xa0
154#define IPTOS_PREC_FLASHOVERRIDE 0x80
155#define IPTOS_PREC_FLASH 0x60
156#define IPTOS_PREC_IMMEDIATE 0x40
157#define IPTOS_PREC_PRIORITY 0x20
158#define IPTOS_PREC_ROUTINE 0x00
159
160/*
161 * Definitions for options.
162 */
163#define IPOPT_COPIED(o) ((o)&0x80)
164#define IPOPT_CLASS(o) ((o)&0x60)
165#define IPOPT_NUMBER(o) ((o)&0x1f)
166
167#define IPOPT_CONTROL 0x00
168#define IPOPT_RESERVED1 0x20
169#define IPOPT_DEBMEAS 0x40
170#define IPOPT_RESERVED2 0x60
171
172#define IPOPT_EOL 0 /* end of option list */
173#define IPOPT_NOP 1 /* no operation */
174
175#define IPOPT_RR 7 /* record packet route */
176#define IPOPT_TS 68 /* timestamp */
177#define IPOPT_SECURITY 130 /* provide s,c,h,tcc */
178#define IPOPT_LSRR 131 /* loose source route */
179#define IPOPT_SATID 136 /* satnet id */
180#define IPOPT_SSRR 137 /* strict source route */
181
182/*
183 * Offsets to fields in options other than EOL and NOP.
184 */
185#define IPOPT_OPTVAL 0 /* option ID */
186#define IPOPT_OLEN 1 /* option length */
187#define IPOPT_OFFSET 2 /* offset within option */
188#define IPOPT_MINOFF 4 /* min value of above */
189
190/*
191 * Time stamp option structure.
192 */
193struct ip_timestamp {
194 u_int8_t ipt_code; /* IPOPT_TS */
195 u_int8_t ipt_len; /* size of structure (variable) */
196 u_int8_t ipt_ptr; /* index of current entry */
197#if BYTE_ORDER == LITTLE_ENDIAN
198 unsigned int ipt_flg:4, /* flags, see below */
199 ipt_oflw:4; /* overflow counter */
200#endif
201#if BYTE_ORDER == BIG_ENDIAN
202 unsigned int ipt_oflw:4, /* overflow counter */
203 ipt_flg:4; /* flags, see below */
204#endif
205 union ipt_timestamp {
206 n_time ipt_time[1];
207 struct ipt_ta {
208 struct in_addr ipt_addr;
209 n_time ipt_time;
210 } ipt_ta[1];
211 } ipt_timestamp;
212};
213
214/* flag bits for ipt_flg */
215#define IPOPT_TS_TSONLY 0 /* timestamps only */
216#define IPOPT_TS_TSANDADDR 1 /* timestamps and addresses */
217#define IPOPT_TS_PRESPEC 3 /* specified modules only */
218
219/* bits for security (not byte swapped) */
220#define IPOPT_SECUR_UNCLASS 0x0000
221#define IPOPT_SECUR_CONFID 0xf135
222#define IPOPT_SECUR_EFTO 0x789a
223#define IPOPT_SECUR_MMMM 0xbc4d
224#define IPOPT_SECUR_RESTR 0xaf13
225#define IPOPT_SECUR_SECRET 0xd788
226#define IPOPT_SECUR_TOPSECRET 0x6bc5
227
228/*
229 * Internet implementation parameters.
230 */
231#define MAXTTL 255 /* maximum time to live (seconds) */
232#define IPDEFTTL 64 /* default ttl, from RFC 1340 */
233#define IPFRAGTTL 60 /* time to live for frags, slowhz */
234#define IPTTLDEC 1 /* subtracted when forwarding */
235
236#define IP_MSS 576 /* default maximum segment size */
237
238/*
239 * This is the real IPv4 pseudo header, used for computing the TCP and UDP
240 * checksums. For the Internet checksum, struct ipovly can be used instead.
241 * For stronger checksums, the real thing must be used.
242 */
243struct ippseudo {
244 struct in_addr ippseudo_src; /* source internet address */
245 struct in_addr ippseudo_dst; /* destination internet address */
246 u_int8_t ippseudo_pad; /* pad, must be zero */
247 u_int8_t ippseudo_p; /* protocol */
248 u_int16_t ippseudo_len; /* protocol length */
249};
250
251#ifdef __CTASSERT
252__CTASSERT(sizeof(struct ip) == 20);
253__CTASSERT(sizeof(struct ip_timestamp) == 12);
254__CTASSERT(sizeof(struct ippseudo) == 12);
255#endif
256
257#endif /* !_NETINET_IP_H_ */