xref: /freebsd/sys/netinet/ip.h (revision dd41de95a84d979615a2ef11df6850622bf6184e)
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  */
51 struct 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  */
173 struct	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  */
222 struct 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