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 */
 34
 35#ifndef _NETINET_IP_H_
 36#define	_NETINET_IP_H_
 37
 38#include <sys/cdefs.h>
 39
 40/*
 41 * Definitions for internet protocol version 4.
 42 *
 43 * Per RFC 791, September 1981.
 44 */
 45#define	IPVERSION	4
 46
 47/*
 48 * Structure of an internet header, naked of options.
 49 */
 50struct ip {
 51#if BYTE_ORDER == LITTLE_ENDIAN
 52	u_char	ip_hl:4,		/* header length */
 53		ip_v:4;			/* version */
 54#endif
 55#if BYTE_ORDER == BIG_ENDIAN
 56	u_char	ip_v:4,			/* version */
 57		ip_hl:4;		/* header length */
 58#endif
 59	u_char	ip_tos;			/* type of service */
 60	u_short	ip_len;			/* total length */
 61	u_short	ip_id;			/* identification */
 62	u_short	ip_off;			/* fragment offset field */
 63#define	IP_RF 0x8000			/* reserved fragment flag */
 64#define	IP_DF 0x4000			/* dont fragment flag */
 65#define	IP_MF 0x2000			/* more fragments flag */
 66#define	IP_OFFMASK 0x1fff		/* mask for fragmenting bits */
 67	u_char	ip_ttl;			/* time to live */
 68	u_char	ip_p;			/* protocol */
 69	u_short	ip_sum;			/* checksum */
 70	struct	in_addr ip_src,ip_dst;	/* source and dest address */
 71} __packed __aligned(2);
 72
 73#define	IP_MAXPACKET	65535		/* maximum packet size */
 74
 75/*
 76 * Definitions for IP type of service (ip_tos).
 77 */
 78#define	IPTOS_LOWDELAY		0x10
 79#define	IPTOS_THROUGHPUT	0x08
 80#define	IPTOS_RELIABILITY	0x04
 81#define	IPTOS_MINCOST		IPTOS_DSCP_CS0
 82
 83/*
 84 * Definitions for IP precedence (also in ip_tos) (deprecated).
 85 */
 86#define	IPTOS_PREC_NETCONTROL		IPTOS_DSCP_CS7
 87#define	IPTOS_PREC_INTERNETCONTROL	IPTOS_DSCP_CS6
 88#define	IPTOS_PREC_CRITIC_ECP		IPTOS_DSCP_CS5
 89#define	IPTOS_PREC_FLASHOVERRIDE	IPTOS_DSCP_CS4
 90#define	IPTOS_PREC_FLASH		IPTOS_DSCP_CS3
 91#define	IPTOS_PREC_IMMEDIATE		IPTOS_DSCP_CS2
 92#define	IPTOS_PREC_PRIORITY		IPTOS_DSCP_CS1
 93#define	IPTOS_PREC_ROUTINE		IPTOS_DSCP_CS0
 94
 95/*
 96 * Offset of Diffserv decimal value to convert it to tos value .
 97 */
 98#define	IPTOS_DSCP_OFFSET		2
 99
100/*
101 * Definitions for DiffServ Codepoints as per RFC2474 and RFC5865.
102 */
103#define	IPTOS_DSCP_CS0		0x00
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 mapped to the
128 * 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_ESO		133		/* extended security */
156#define	IPOPT_CIPSO		134		/* commercial security */
157#define	IPOPT_SATID		136		/* satnet id */
158#define	IPOPT_SSRR		137		/* strict source route */
159#define	IPOPT_RA		148		/* router alert */
160
161/*
162 * Offsets to fields in options other than EOL and NOP.
163 */
164#define	IPOPT_OPTVAL		0		/* option ID */
165#define	IPOPT_OLEN		1		/* option length */
166#define	IPOPT_OFFSET		2		/* offset within option */
167#define	IPOPT_MINOFF		4		/* min value of above */
168
169/*
170 * Time stamp option structure.
171 */
172struct	ip_timestamp {
173	u_char	ipt_code;		/* IPOPT_TS */
174	u_char	ipt_len;		/* size of structure (variable) */
175	u_char	ipt_ptr;		/* index of current entry */
176#if BYTE_ORDER == LITTLE_ENDIAN
177	u_char	ipt_flg:4,		/* flags, see below */
178		ipt_oflw:4;		/* overflow counter */
179#endif
180#if BYTE_ORDER == BIG_ENDIAN
181	u_char	ipt_oflw:4,		/* overflow counter */
182		ipt_flg:4;		/* flags, see below */
183#endif
184	union ipt_timestamp {
185		uint32_t	ipt_time[1];	/* network format */
186		struct	ipt_ta {
187			struct in_addr ipt_addr;
188			uint32_t ipt_time;	/* network format */
189		} ipt_ta[1];
190	} ipt_timestamp;
191};
192
193/* Flag bits for ipt_flg. */
194#define	IPOPT_TS_TSONLY		0		/* timestamps only */
195#define	IPOPT_TS_TSANDADDR	1		/* timestamps and addresses */
196#define	IPOPT_TS_PRESPEC	3		/* specified modules only */
197
198/* Bits for security (not byte swapped). */
199#define	IPOPT_SECUR_UNCLASS	0x0000
200#define	IPOPT_SECUR_CONFID	0xf135
201#define	IPOPT_SECUR_EFTO	0x789a
202#define	IPOPT_SECUR_MMMM	0xbc4d
203#define	IPOPT_SECUR_RESTR	0xaf13
204#define	IPOPT_SECUR_SECRET	0xd788
205#define	IPOPT_SECUR_TOPSECRET	0x6bc5
206
207/*
208 * Internet implementation parameters.
209 */
210#define	MAXTTL		255		/* maximum time to live (seconds) */
211#define	IPDEFTTL	64		/* default ttl, from RFC 1340 */
212#define	IPTTLDEC	1		/* subtracted when forwarding */
213#define	IP_MSS		576		/* default maximum segment size */
214
215/*
216 * This is the real IPv4 pseudo header, used for computing the TCP and UDP
217 * checksums. For the Internet checksum, struct ipovly can be used instead.
218 * For stronger checksums, the real thing must be used.
219 */
220struct ippseudo {
221	struct	in_addr	ippseudo_src;	/* source internet address */
222	struct	in_addr	ippseudo_dst;	/* destination internet address */
223	u_char		ippseudo_pad;	/* pad, must be zero */
224	u_char		ippseudo_p;	/* protocol */
225	u_short		ippseudo_len;	/* protocol length */
226};
227#endif