xref: /freebsd/sys/netinet/ip.h (revision 9ee759f3676f700f8224a95216f659f87f5d9ae9)
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 
33 #ifndef _NETINET_IP_H_
34 #define	_NETINET_IP_H_
35 
36 #include <sys/types.h>
37 #include <netinet/in.h>
38 
39 /*
40  * Definitions for internet protocol version 4.
41  *
42  * Per RFC 791, September 1981.
43  */
44 #define	IPVERSION	4
45 
46 /*
47  * Structure of an internet header, naked of options.
48  */
49 struct ip {
50 #if BYTE_ORDER == LITTLE_ENDIAN
51 	u_char	ip_hl:4,		/* header length */
52 		ip_v:4;			/* version */
53 #endif
54 #if BYTE_ORDER == BIG_ENDIAN
55 	u_char	ip_v:4,			/* version */
56 		ip_hl:4;		/* header length */
57 #endif
58 	u_char	ip_tos;			/* type of service */
59 	u_short	ip_len;			/* total length */
60 	u_short	ip_id;			/* identification */
61 	u_short	ip_off;			/* fragment offset field */
62 #define	IP_RF 0x8000			/* reserved fragment flag */
63 #define	IP_DF 0x4000			/* dont fragment flag */
64 #define	IP_MF 0x2000			/* more fragments flag */
65 #define	IP_OFFMASK 0x1fff		/* mask for fragmenting bits */
66 	u_char	ip_ttl;			/* time to live */
67 	u_char	ip_p;			/* protocol */
68 	u_short	ip_sum;			/* checksum */
69 	struct	in_addr ip_src,ip_dst;	/* source and dest address */
70 } __packed;
71 
72 #define	IP_MAXPACKET	65535		/* maximum packet size */
73 
74 /*
75  * Definitions for IP type of service (ip_tos).
76  */
77 #define	IPTOS_LOWDELAY		0x10
78 #define	IPTOS_THROUGHPUT	0x08
79 #define	IPTOS_RELIABILITY	0x04
80 #define	IPTOS_MINCOST		IPTOS_DSCP_CS0
81 
82 /*
83  * Definitions for IP precedence (also in ip_tos) (deprecated).
84  */
85 #define	IPTOS_PREC_NETCONTROL		IPTOS_DSCP_CS7
86 #define	IPTOS_PREC_INTERNETCONTROL	IPTOS_DSCP_CS6
87 #define	IPTOS_PREC_CRITIC_ECP		IPTOS_DSCP_CS5
88 #define	IPTOS_PREC_FLASHOVERRIDE	IPTOS_DSCP_CS4
89 #define	IPTOS_PREC_FLASH		IPTOS_DSCP_CS3
90 #define	IPTOS_PREC_IMMEDIATE		IPTOS_DSCP_CS2
91 #define	IPTOS_PREC_PRIORITY		IPTOS_DSCP_CS1
92 #define	IPTOS_PREC_ROUTINE		IPTOS_DSCP_CS0
93 
94 /*
95  * Offset of Diffserv decimal value to convert it to tos value .
96  */
97 #define	IPTOS_DSCP_OFFSET		2
98 
99 /*
100  * Definitions for DiffServ Codepoints as per RFC2474 and RFC5865.
101  */
102 #define	IPTOS_DSCP_CS0		0x00
103 #define	IPTOS_DSCP_CS1		0x20
104 #define	IPTOS_DSCP_AF11		0x28
105 #define	IPTOS_DSCP_AF12		0x30
106 #define	IPTOS_DSCP_AF13		0x38
107 #define	IPTOS_DSCP_CS2		0x40
108 #define	IPTOS_DSCP_AF21		0x48
109 #define	IPTOS_DSCP_AF22		0x50
110 #define	IPTOS_DSCP_AF23		0x58
111 #define	IPTOS_DSCP_CS3		0x60
112 #define	IPTOS_DSCP_AF31		0x68
113 #define	IPTOS_DSCP_AF32		0x70
114 #define	IPTOS_DSCP_AF33		0x78
115 #define	IPTOS_DSCP_CS4		0x80
116 #define	IPTOS_DSCP_AF41		0x88
117 #define	IPTOS_DSCP_AF42		0x90
118 #define	IPTOS_DSCP_AF43		0x98
119 #define	IPTOS_DSCP_CS5		0xa0
120 #define	IPTOS_DSCP_VA		0xb0
121 #define	IPTOS_DSCP_EF		0xb8
122 #define	IPTOS_DSCP_CS6		0xc0
123 #define	IPTOS_DSCP_CS7		0xe0
124 
125 /*
126  * ECN (Explicit Congestion Notification) codepoints in RFC3168 mapped to the
127  * lower 2 bits of the TOS field.
128  */
129 #define	IPTOS_ECN_NOTECT	0x00	/* not-ECT */
130 #define	IPTOS_ECN_ECT1		0x01	/* ECN-capable transport (1) */
131 #define	IPTOS_ECN_ECT0		0x02	/* ECN-capable transport (0) */
132 #define	IPTOS_ECN_CE		0x03	/* congestion experienced */
133 #define	IPTOS_ECN_MASK		0x03	/* ECN field mask */
134 
135 /*
136  * Definitions for options.
137  */
138 #define	IPOPT_COPIED(o)		((o)&0x80)
139 #define	IPOPT_CLASS(o)		((o)&0x60)
140 #define	IPOPT_NUMBER(o)		((o)&0x1f)
141 
142 #define	IPOPT_CONTROL		0x00
143 #define	IPOPT_RESERVED1		0x20
144 #define	IPOPT_DEBMEAS		0x40
145 #define	IPOPT_RESERVED2		0x60
146 
147 #define	IPOPT_EOL		0		/* end of option list */
148 #define	IPOPT_NOP		1		/* no operation */
149 
150 #define	IPOPT_RR		7		/* record packet route */
151 #define	IPOPT_TS		68		/* timestamp */
152 #define	IPOPT_SECURITY		130		/* provide s,c,h,tcc */
153 #define	IPOPT_LSRR		131		/* loose source route */
154 #define	IPOPT_ESO		133		/* extended security */
155 #define	IPOPT_CIPSO		134		/* commercial security */
156 #define	IPOPT_SATID		136		/* satnet id */
157 #define	IPOPT_SSRR		137		/* strict source route */
158 #define	IPOPT_RA		148		/* router alert */
159 
160 /*
161  * Offsets to fields in options other than EOL and NOP.
162  */
163 #define	IPOPT_OPTVAL		0		/* option ID */
164 #define	IPOPT_OLEN		1		/* option length */
165 #define	IPOPT_OFFSET		2		/* offset within option */
166 #define	IPOPT_MINOFF		4		/* min value of above */
167 
168 /*
169  * Time stamp option structure.
170  */
171 struct	ip_timestamp {
172 	u_char	ipt_code;		/* IPOPT_TS */
173 	u_char	ipt_len;		/* size of structure (variable) */
174 	u_char	ipt_ptr;		/* index of current entry */
175 #if BYTE_ORDER == LITTLE_ENDIAN
176 	u_char	ipt_flg:4,		/* flags, see below */
177 		ipt_oflw:4;		/* overflow counter */
178 #endif
179 #if BYTE_ORDER == BIG_ENDIAN
180 	u_char	ipt_oflw:4,		/* overflow counter */
181 		ipt_flg:4;		/* flags, see below */
182 #endif
183 	union ipt_timestamp {
184 		uint32_t	ipt_time[1];	/* network format */
185 		struct	ipt_ta {
186 			struct in_addr ipt_addr;
187 			uint32_t ipt_time;	/* network format */
188 		} ipt_ta[1];
189 	} ipt_timestamp;
190 } __packed;
191 
192 /* Flag bits for ipt_flg. */
193 #define	IPOPT_TS_TSONLY		0		/* timestamps only */
194 #define	IPOPT_TS_TSANDADDR	1		/* timestamps and addresses */
195 #define	IPOPT_TS_PRESPEC	3		/* specified modules only */
196 
197 /* Bits for security (not byte swapped). */
198 #define	IPOPT_SECUR_UNCLASS	0x0000
199 #define	IPOPT_SECUR_CONFID	0xf135
200 #define	IPOPT_SECUR_EFTO	0x789a
201 #define	IPOPT_SECUR_MMMM	0xbc4d
202 #define	IPOPT_SECUR_RESTR	0xaf13
203 #define	IPOPT_SECUR_SECRET	0xd788
204 #define	IPOPT_SECUR_TOPSECRET	0x6bc5
205 
206 /*
207  * Internet implementation parameters.
208  */
209 #define	MAXTTL		255		/* maximum time to live (seconds) */
210 #define	IPDEFTTL	64		/* default ttl, from RFC 1340 */
211 #define	IPTTLDEC	1		/* subtracted when forwarding */
212 #define	IP_MSS		576		/* default maximum segment size */
213 
214 /*
215  * This is the real IPv4 pseudo header, used for computing the TCP and UDP
216  * checksums. For the Internet checksum, struct ipovly can be used instead.
217  * For stronger checksums, the real thing must be used.
218  */
219 struct ippseudo {
220 	struct	in_addr	ippseudo_src;	/* source internet address */
221 	struct	in_addr	ippseudo_dst;	/* destination internet address */
222 	u_char		ippseudo_pad;	/* pad, must be zero */
223 	u_char		ippseudo_p;	/* protocol */
224 	u_short		ippseudo_len;	/* protocol length */
225 };
226 #endif
227