1/* Copyright (C) 1991-2026 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
17
18#ifndef __NETINET_IP_H
19#define __NETINET_IP_H 1
20
21#include <features.h>
22#include <sys/types.h>
23
24#include <netinet/in.h>
25
26__BEGIN_DECLS
27
28struct timestamp
29 {
30 uint8_t len;
31 uint8_t ptr;
32#if __BYTE_ORDER == __LITTLE_ENDIAN
33 unsigned int flags:4;
34 unsigned int overflow:4;
35#elif __BYTE_ORDER == __BIG_ENDIAN
36 unsigned int overflow:4;
37 unsigned int flags:4;
38#else
39# error "Please fix <bits/endian.h>"
40#endif
41 uint32_t data[9];
42 };
43
44struct iphdr
45 {
46#if __BYTE_ORDER == __LITTLE_ENDIAN
47 unsigned int ihl:4;
48 unsigned int version:4;
49#elif __BYTE_ORDER == __BIG_ENDIAN
50 unsigned int version:4;
51 unsigned int ihl:4;
52#else
53# error "Please fix <bits/endian.h>"
54#endif
55 uint8_t tos;
56 uint16_t tot_len;
57 uint16_t id;
58 uint16_t frag_off;
59 uint8_t ttl;
60 uint8_t protocol;
61 uint16_t check;
62 uint32_t saddr;
63 uint32_t daddr;
64 /*The options start here. */
65 };
66
67#ifdef __USE_MISC
68/*
69 * Copyright (c) 1982, 1986, 1993
70 * The Regents of the University of California. All rights reserved.
71 *
72 * Redistribution and use in source and binary forms, with or without
73 * modification, are permitted provided that the following conditions
74 * are met:
75 * 1. Redistributions of source code must retain the above copyright
76 * notice, this list of conditions and the following disclaimer.
77 * 2. Redistributions in binary form must reproduce the above copyright
78 * notice, this list of conditions and the following disclaimer in the
79 * documentation and/or other materials provided with the distribution.
80 * 4. Neither the name of the University nor the names of its contributors
81 * may be used to endorse or promote products derived from this software
82 * without specific prior written permission.
83 *
84 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
85 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
86 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
87 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
88 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
89 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
90 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
91 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
92 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
93 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
94 * SUCH DAMAGE.
95 *
96 * @(#)ip.h 8.1 (Berkeley) 6/10/93
97 */
98
99/*
100 * Definitions for internet protocol version 4.
101 * Per RFC 791, September 1981.
102 */
103
104/*
105 * Structure of an internet header, naked of options.
106 */
107struct ip
108 {
109#if __BYTE_ORDER == __LITTLE_ENDIAN
110 unsigned int ip_hl:4; /* header length */
111 unsigned int ip_v:4; /* version */
112#endif
113#if __BYTE_ORDER == __BIG_ENDIAN
114 unsigned int ip_v:4; /* version */
115 unsigned int ip_hl:4; /* header length */
116#endif
117 uint8_t ip_tos; /* type of service */
118 unsigned short ip_len; /* total length */
119 unsigned short ip_id; /* identification */
120 unsigned short ip_off; /* fragment offset field */
121#define IP_RF 0x8000 /* reserved fragment flag */
122#define IP_DF 0x4000 /* dont fragment flag */
123#define IP_MF 0x2000 /* more fragments flag */
124#define IP_OFFMASK 0x1fff /* mask for fragmenting bits */
125 uint8_t ip_ttl; /* time to live */
126 uint8_t ip_p; /* protocol */
127 unsigned short ip_sum; /* checksum */
128 struct in_addr ip_src, ip_dst; /* source and dest address */
129 };
130
131/*
132 * Time stamp option structure.
133 */
134struct ip_timestamp
135 {
136 uint8_t ipt_code; /* IPOPT_TS */
137 uint8_t ipt_len; /* size of structure (variable) */
138 uint8_t ipt_ptr; /* index of current entry */
139#if __BYTE_ORDER == __LITTLE_ENDIAN
140 unsigned int ipt_flg:4; /* flags, see below */
141 unsigned int ipt_oflw:4; /* overflow counter */
142#endif
143#if __BYTE_ORDER == __BIG_ENDIAN
144 unsigned int ipt_oflw:4; /* overflow counter */
145 unsigned int ipt_flg:4; /* flags, see below */
146#endif
147 uint32_t data[9];
148 };
149#endif /* __USE_MISC */
150
151#define IPVERSION 4 /* IP version number */
152#define IP_MAXPACKET 65535 /* maximum packet size */
153
154/*
155 * Definitions for Explicit Congestion Notification (ECN)
156 *
157 * Taken from RFC-3168, Section 5.
158 */
159
160#define IPTOS_ECN_MASK 0x03
161#define IPTOS_ECN(x) ((x) & IPTOS_ECN_MASK)
162#define IPTOS_ECN_NOT_ECT 0x00
163#define IPTOS_ECN_ECT1 0x01
164#define IPTOS_ECN_ECT0 0x02
165#define IPTOS_ECN_CE 0x03
166
167/*
168 * Definitions for IP differentiated services code points (DSCP)
169 *
170 * Taken from RFC-2597, Section 6 and RFC-2598, Section 2.3.
171 */
172
173#define IPTOS_DSCP_MASK 0xfc
174#define IPTOS_DSCP(x) ((x) & IPTOS_DSCP_MASK)
175#define IPTOS_DSCP_AF11 0x28
176#define IPTOS_DSCP_AF12 0x30
177#define IPTOS_DSCP_AF13 0x38
178#define IPTOS_DSCP_AF21 0x48
179#define IPTOS_DSCP_AF22 0x50
180#define IPTOS_DSCP_AF23 0x58
181#define IPTOS_DSCP_AF31 0x68
182#define IPTOS_DSCP_AF32 0x70
183#define IPTOS_DSCP_AF33 0x78
184#define IPTOS_DSCP_AF41 0x88
185#define IPTOS_DSCP_AF42 0x90
186#define IPTOS_DSCP_AF43 0x98
187#define IPTOS_DSCP_EF 0xb8
188
189/*
190 * Voice-Admit DSCP code point from RFC-5865, Section 4.
191 */
192#define IPTOS_DSCP_VA 0xb0
193
194/*
195 * Lower-Effort Per-Hop Behavior DSCP code point from RFC-8622, Section 12.
196 */
197#define IPTOS_DSCP_LE 0x04
198
199/*
200 * In RFC 2474, Section 4.2.2.1, the Class Selector Codepoints subsume
201 * the old ToS Precedence values.
202 */
203
204#define IPTOS_CLASS_MASK 0xe0
205#define IPTOS_CLASS(class) ((class) & IPTOS_CLASS_MASK)
206#define IPTOS_CLASS_CS0 0x00
207#define IPTOS_CLASS_CS1 0x20
208#define IPTOS_CLASS_CS2 0x40
209#define IPTOS_CLASS_CS3 0x60
210#define IPTOS_CLASS_CS4 0x80
211#define IPTOS_CLASS_CS5 0xa0
212#define IPTOS_CLASS_CS6 0xc0
213#define IPTOS_CLASS_CS7 0xe0
214
215#define IPTOS_CLASS_DEFAULT IPTOS_CLASS_CS0
216
217/*
218 * Definitions for IP type of service (ip_tos) [deprecated; use DSCP
219 * and CS definitions above instead.]
220 */
221#define IPTOS_TOS_MASK 0x1E
222#define IPTOS_TOS(tos) ((tos) & IPTOS_TOS_MASK)
223#define IPTOS_LOWDELAY 0x10
224#define IPTOS_THROUGHPUT 0x08
225#define IPTOS_RELIABILITY 0x04
226#define IPTOS_LOWCOST 0x02
227#define IPTOS_MINCOST IPTOS_LOWCOST
228
229/*
230 * Definitions for IP precedence (also in ip_tos) [also deprecated.]
231 */
232#define IPTOS_PREC_MASK IPTOS_CLASS_MASK
233#define IPTOS_PREC(tos) IPTOS_CLASS(tos)
234#define IPTOS_PREC_NETCONTROL IPTOS_CLASS_CS7
235#define IPTOS_PREC_INTERNETCONTROL IPTOS_CLASS_CS6
236#define IPTOS_PREC_CRITIC_ECP IPTOS_CLASS_CS5
237#define IPTOS_PREC_FLASHOVERRIDE IPTOS_CLASS_CS4
238#define IPTOS_PREC_FLASH IPTOS_CLASS_CS3
239#define IPTOS_PREC_IMMEDIATE IPTOS_CLASS_CS2
240#define IPTOS_PREC_PRIORITY IPTOS_CLASS_CS1
241#define IPTOS_PREC_ROUTINE IPTOS_CLASS_CS0
242
243/*
244 * Definitions for options.
245 */
246#define IPOPT_COPY 0x80
247#define IPOPT_CLASS_MASK 0x60
248#define IPOPT_NUMBER_MASK 0x1f
249
250#define IPOPT_COPIED(o) ((o) & IPOPT_COPY)
251#define IPOPT_CLASS(o) ((o) & IPOPT_CLASS_MASK)
252#define IPOPT_NUMBER(o) ((o) & IPOPT_NUMBER_MASK)
253
254#define IPOPT_CONTROL 0x00
255#define IPOPT_RESERVED1 0x20
256#define IPOPT_DEBMEAS 0x40
257#define IPOPT_MEASUREMENT IPOPT_DEBMEAS
258#define IPOPT_RESERVED2 0x60
259
260#define IPOPT_EOL 0 /* end of option list */
261#define IPOPT_END IPOPT_EOL
262#define IPOPT_NOP 1 /* no operation */
263#define IPOPT_NOOP IPOPT_NOP
264
265#define IPOPT_RR 7 /* record packet route */
266#define IPOPT_TS 68 /* timestamp */
267#define IPOPT_TIMESTAMP IPOPT_TS
268#define IPOPT_SECURITY 130 /* provide s,c,h,tcc */
269#define IPOPT_SEC IPOPT_SECURITY
270#define IPOPT_LSRR 131 /* loose source route */
271#define IPOPT_SATID 136 /* satnet id */
272#define IPOPT_SID IPOPT_SATID
273#define IPOPT_SSRR 137 /* strict source route */
274#define IPOPT_RA 148 /* router alert */
275
276/*
277 * Offsets to fields in options other than EOL and NOP.
278 */
279#define IPOPT_OPTVAL 0 /* option ID */
280#define IPOPT_OLEN 1 /* option length */
281#define IPOPT_OFFSET 2 /* offset within option */
282#define IPOPT_MINOFF 4 /* min value of above */
283
284#define MAX_IPOPTLEN 40
285
286/* flag bits for ipt_flg */
287#define IPOPT_TS_TSONLY 0 /* timestamps only */
288#define IPOPT_TS_TSANDADDR 1 /* timestamps and addresses */
289#define IPOPT_TS_PRESPEC 3 /* specified modules only */
290
291/* bits for security (not byte swapped) */
292#define IPOPT_SECUR_UNCLASS 0x0000
293#define IPOPT_SECUR_CONFID 0xf135
294#define IPOPT_SECUR_EFTO 0x789a
295#define IPOPT_SECUR_MMMM 0xbc4d
296#define IPOPT_SECUR_RESTR 0xaf13
297#define IPOPT_SECUR_SECRET 0xd788
298#define IPOPT_SECUR_TOPSECRET 0x6bc5
299
300/*
301 * Internet implementation parameters.
302 */
303#define MAXTTL 255 /* maximum time to live (seconds) */
304#define IPDEFTTL 64 /* default ttl, from RFC 1340 */
305#define IPFRAGTTL 60 /* time to live for frags, slowhz */
306#define IPTTLDEC 1 /* subtracted when forwarding */
307
308#define IP_MSS 576 /* default maximum segment size */
309
310__END_DECLS
311
312#endif /* netinet/ip.h */