1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1982, 1986, 1993
5 *	The Regents of the University of California.
6 * 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	8.2 (Berkeley) 6/1/94
33 * $FreeBSD$
34 */
35
36#ifndef _NETINET_IP_H_
37#define	_NETINET_IP_H_
38
39#include <sys/cdefs.h>
40
41/*
42 * Definitions for internet protocol version 4.
43 *
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	u_char	ip_hl:4,		/* header length */
54		ip_v:4;			/* version */
55#endif
56#if BYTE_ORDER == BIG_ENDIAN
57	u_char	ip_v:4,			/* version */
58		ip_hl:4;		/* header length */
59#endif
60	u_char	ip_tos;			/* type of service */
61	u_short	ip_len;			/* total length */
62	u_short	ip_id;			/* identification */
63	u_short	ip_off;			/* fragment offset field */
64#define	IP_RF 0x8000			/* reserved fragment flag */
65#define	IP_DF 0x4000			/* dont fragment flag */
66#define	IP_MF 0x2000			/* more fragments flag */
67#define	IP_OFFMASK 0x1fff		/* mask for fragmenting bits */
68	u_char	ip_ttl;			/* time to live */
69	u_char	ip_p;			/* protocol */
70	u_short	ip_sum;			/* checksum */
71	struct	in_addr ip_src,ip_dst;	/* source and dest address */
72} __packed __aligned(2);
73
74#define	IP_MAXPACKET	65535		/* maximum packet size */
75
76/*
77 * Definitions for IP type of service (ip_tos).
78 */
79#define	IPTOS_LOWDELAY		0x10
80#define	IPTOS_THROUGHPUT	0x08
81#define	IPTOS_RELIABILITY	0x04
82#define	IPTOS_MINCOST		0x02
83
84/*
85 * Definitions for IP precedence (also in ip_tos) (deprecated).
86 */
87#define	IPTOS_PREC_NETCONTROL		IPTOS_DSCP_CS7
88#define	IPTOS_PREC_INTERNETCONTROL	IPTOS_DSCP_CS6
89#define	IPTOS_PREC_CRITIC_ECP		IPTOS_DSCP_CS5
90#define	IPTOS_PREC_FLASHOVERRIDE	IPTOS_DSCP_CS4
91#define	IPTOS_PREC_FLASH		IPTOS_DSCP_CS3
92#define	IPTOS_PREC_IMMEDIATE		IPTOS_DSCP_CS2
93#define	IPTOS_PREC_PRIORITY		IPTOS_DSCP_CS1
94#define	IPTOS_PREC_ROUTINE		IPTOS_DSCP_CS0
95
96/*
97 * Offset of Diffserv decimal value to convert it to tos value .
98 */
99#define	IPTOS_DSCP_OFFSET		2
100
101/*
102 * Definitions for DiffServ Codepoints as per RFC2474 and RFC5865.
103 */
104#define	IPTOS_DSCP_CS0		0x00
105#define	IPTOS_DSCP_CS1		0x20
106#define	IPTOS_DSCP_AF11		0x28
107#define	IPTOS_DSCP_AF12		0x30
108#define	IPTOS_DSCP_AF13		0x38
109#define	IPTOS_DSCP_CS2		0x40
110#define	IPTOS_DSCP_AF21		0x48
111#define	IPTOS_DSCP_AF22		0x50
112#define	IPTOS_DSCP_AF23		0x58
113#define	IPTOS_DSCP_CS3		0x60
114#define	IPTOS_DSCP_AF31		0x68
115#define	IPTOS_DSCP_AF32		0x70
116#define	IPTOS_DSCP_AF33		0x78
117#define	IPTOS_DSCP_CS4		0x80
118#define	IPTOS_DSCP_AF41		0x88
119#define	IPTOS_DSCP_AF42		0x90
120#define	IPTOS_DSCP_AF43		0x98
121#define	IPTOS_DSCP_CS5		0xa0
122#define	IPTOS_DSCP_VA		0xb0
123#define	IPTOS_DSCP_EF		0xb8
124#define	IPTOS_DSCP_CS6		0xc0
125#define	IPTOS_DSCP_CS7		0xe0
126
127/*
128 * ECN (Explicit Congestion Notification) codepoints in RFC3168 mapped to the
129 * lower 2 bits of the TOS field.
130 */
131#define	IPTOS_ECN_NOTECT	0x00	/* not-ECT */
132#define	IPTOS_ECN_ECT1		0x01	/* ECN-capable transport (1) */
133#define	IPTOS_ECN_ECT0		0x02	/* ECN-capable transport (0) */
134#define	IPTOS_ECN_CE		0x03	/* congestion experienced */
135#define	IPTOS_ECN_MASK		0x03	/* ECN field mask */
136
137/*
138 * Definitions for options.
139 */
140#define	IPOPT_COPIED(o)		((o)&0x80)
141#define	IPOPT_CLASS(o)		((o)&0x60)
142#define	IPOPT_NUMBER(o)		((o)&0x1f)
143
144#define	IPOPT_CONTROL		0x00
145#define	IPOPT_RESERVED1		0x20
146#define	IPOPT_DEBMEAS		0x40
147#define	IPOPT_RESERVED2		0x60
148
149#define	IPOPT_EOL		0		/* end of option list */
150#define	IPOPT_NOP		1		/* no operation */
151
152#define	IPOPT_RR		7		/* record packet route */
153#define	IPOPT_TS		68		/* timestamp */
154#define	IPOPT_SECURITY		130		/* provide s,c,h,tcc */
155#define	IPOPT_LSRR		131		/* loose source route */
156#define	IPOPT_ESO		133		/* extended security */
157#define	IPOPT_CIPSO		134		/* commercial security */
158#define	IPOPT_SATID		136		/* satnet id */
159#define	IPOPT_SSRR		137		/* strict source route */
160#define	IPOPT_RA		148		/* router alert */
161
162/*
163 * Offsets to fields in options other than EOL and NOP.
164 */
165#define	IPOPT_OPTVAL		0		/* option ID */
166#define	IPOPT_OLEN		1		/* option length */
167#define	IPOPT_OFFSET		2		/* offset within option */
168#define	IPOPT_MINOFF		4		/* min value of above */
169
170/*
171 * Time stamp option structure.
172 */
173struct	ip_timestamp {
174	u_char	ipt_code;		/* IPOPT_TS */
175	u_char	ipt_len;		/* size of structure (variable) */
176	u_char	ipt_ptr;		/* index of current entry */
177#if BYTE_ORDER == LITTLE_ENDIAN
178	u_char	ipt_flg:4,		/* flags, see below */
179		ipt_oflw:4;		/* overflow counter */
180#endif
181#if BYTE_ORDER == BIG_ENDIAN
182	u_char	ipt_oflw:4,		/* overflow counter */
183		ipt_flg:4;		/* flags, see below */
184#endif
185	union ipt_timestamp {
186		uint32_t	ipt_time[1];	/* network format */
187		struct	ipt_ta {
188			struct in_addr ipt_addr;
189			uint32_t ipt_time;	/* network format */
190		} ipt_ta[1];
191	} ipt_timestamp;
192};
193
194/* Flag bits for ipt_flg. */
195#define	IPOPT_TS_TSONLY		0		/* timestamps only */
196#define	IPOPT_TS_TSANDADDR	1		/* timestamps and addresses */
197#define	IPOPT_TS_PRESPEC	3		/* specified modules only */
198
199/* Bits for security (not byte swapped). */
200#define	IPOPT_SECUR_UNCLASS	0x0000
201#define	IPOPT_SECUR_CONFID	0xf135
202#define	IPOPT_SECUR_EFTO	0x789a
203#define	IPOPT_SECUR_MMMM	0xbc4d
204#define	IPOPT_SECUR_RESTR	0xaf13
205#define	IPOPT_SECUR_SECRET	0xd788
206#define	IPOPT_SECUR_TOPSECRET	0x6bc5
207
208/*
209 * Internet implementation parameters.
210 */
211#define	MAXTTL		255		/* maximum time to live (seconds) */
212#define	IPDEFTTL	64		/* default ttl, from RFC 1340 */
213#define	IPFRAGTTL	60		/* time to live for frags, slowhz */
214#define	IPTTLDEC	1		/* subtracted when forwarding */
215#define	IP_MSS		576		/* default maximum segment size */
216
217/*
218 * This is the real IPv4 pseudo header, used for computing the TCP and UDP
219 * checksums. For the Internet checksum, struct ipovly can be used instead.
220 * For stronger checksums, the real thing must be used.
221 */
222struct ippseudo {
223	struct	in_addr	ippseudo_src;	/* source internet address */
224	struct	in_addr	ippseudo_dst;	/* destination internet address */
225	u_char		ippseudo_pad;	/* pad, must be zero */
226	u_char		ippseudo_p;	/* protocol */
227	u_short		ippseudo_len;	/* protocol length */
228};
229#endif
230