xref: /freebsd/sys/netinet/ip.h (revision 63f9a4cb2684a303e3eb2ffed39c03a2e2b28ae0)
1 /*
2  * Copyright (c) 1982, 1986, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 4. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  *	@(#)ip.h	8.2 (Berkeley) 6/1/94
30  * $FreeBSD$
31  */
32 
33 #ifndef _NETINET_IP_H_
34 #define _NETINET_IP_H_
35 
36 #include <sys/cdefs.h>
37 
38 /*
39  * Definitions for internet protocol version 4.
40  * Per RFC 791, September 1981.
41  */
42 #define	IPVERSION	4
43 
44 /*
45  * Structure of an internet header, naked of options.
46  */
47 struct ip {
48 #if BYTE_ORDER == LITTLE_ENDIAN
49 	u_int	ip_hl:4,		/* header length */
50 		ip_v:4;			/* version */
51 #endif
52 #if BYTE_ORDER == BIG_ENDIAN
53 	u_int	ip_v:4,			/* version */
54 		ip_hl:4;		/* header length */
55 #endif
56 	u_char	ip_tos;			/* type of service */
57 	u_short	ip_len;			/* total length */
58 	u_short	ip_id;			/* identification */
59 	u_short	ip_off;			/* fragment offset field */
60 #define	IP_RF 0x8000			/* reserved fragment flag */
61 #define	IP_DF 0x4000			/* dont fragment flag */
62 #define	IP_MF 0x2000			/* more fragments flag */
63 #define	IP_OFFMASK 0x1fff		/* mask for fragmenting bits */
64 	u_char	ip_ttl;			/* time to live */
65 	u_char	ip_p;			/* protocol */
66 	u_short	ip_sum;			/* checksum */
67 	struct	in_addr ip_src,ip_dst;	/* source and dest address */
68 } __packed;
69 
70 #ifdef CTASSERT
71 CTASSERT(sizeof (struct ip) == 20);
72 #endif
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 #if 1
84 /* ECN RFC3168 obsoletes RFC2481, and these will be deprecated soon. */
85 #define	IPTOS_CE		0x01
86 #define	IPTOS_ECT		0x02
87 #endif
88 
89 /*
90  * Definitions for IP precedence (also in ip_tos) (hopefully unused)
91  */
92 #define	IPTOS_PREC_NETCONTROL		0xe0
93 #define	IPTOS_PREC_INTERNETCONTROL	0xc0
94 #define	IPTOS_PREC_CRITIC_ECP		0xa0
95 #define	IPTOS_PREC_FLASHOVERRIDE	0x80
96 #define	IPTOS_PREC_FLASH		0x60
97 #define	IPTOS_PREC_IMMEDIATE		0x40
98 #define	IPTOS_PREC_PRIORITY		0x20
99 #define	IPTOS_PREC_ROUTINE		0x00
100 
101 /*
102  * ECN (Explicit Congestion Notification) codepoints in RFC3168
103  * mapped to the lower 2 bits of the TOS field.
104  */
105 #define	IPTOS_ECN_NOTECT	0x00	/* not-ECT */
106 #define	IPTOS_ECN_ECT1		0x01	/* ECN-capable transport (1) */
107 #define	IPTOS_ECN_ECT0		0x02	/* ECN-capable transport (0) */
108 #define	IPTOS_ECN_CE		0x03	/* congestion experienced */
109 #define	IPTOS_ECN_MASK		0x03	/* ECN field mask */
110 
111 /*
112  * Definitions for options.
113  */
114 #define	IPOPT_COPIED(o)		((o)&0x80)
115 #define	IPOPT_CLASS(o)		((o)&0x60)
116 #define	IPOPT_NUMBER(o)		((o)&0x1f)
117 
118 #define	IPOPT_CONTROL		0x00
119 #define	IPOPT_RESERVED1		0x20
120 #define	IPOPT_DEBMEAS		0x40
121 #define	IPOPT_RESERVED2		0x60
122 
123 #define	IPOPT_EOL		0		/* end of option list */
124 #define	IPOPT_NOP		1		/* no operation */
125 
126 #define	IPOPT_RR		7		/* record packet route */
127 #define	IPOPT_TS		68		/* timestamp */
128 #define	IPOPT_SECURITY		130		/* provide s,c,h,tcc */
129 #define	IPOPT_LSRR		131		/* loose source route */
130 #define	IPOPT_ESO		133		/* extended security */
131 #define	IPOPT_CIPSO		134		/* commerical security */
132 #define	IPOPT_SATID		136		/* satnet id */
133 #define	IPOPT_SSRR		137		/* strict source route */
134 #define	IPOPT_RA		148		/* router alert */
135 
136 /*
137  * Offsets to fields in options other than EOL and NOP.
138  */
139 #define	IPOPT_OPTVAL		0		/* option ID */
140 #define	IPOPT_OLEN		1		/* option length */
141 #define IPOPT_OFFSET		2		/* offset within option */
142 #define	IPOPT_MINOFF		4		/* min value of above */
143 
144 /*
145  * Time stamp option structure.
146  */
147 struct	ip_timestamp {
148 	u_char	ipt_code;		/* IPOPT_TS */
149 	u_char	ipt_len;		/* size of structure (variable) */
150 	u_char	ipt_ptr;		/* index of current entry */
151 #if BYTE_ORDER == LITTLE_ENDIAN
152 	u_int	ipt_flg:4,		/* flags, see below */
153 		ipt_oflw:4;		/* overflow counter */
154 #endif
155 #if BYTE_ORDER == BIG_ENDIAN
156 	u_int	ipt_oflw:4,		/* overflow counter */
157 		ipt_flg:4;		/* flags, see below */
158 #endif
159 	union ipt_timestamp {
160 		n_long	ipt_time[1];
161 		struct	ipt_ta {
162 			struct in_addr ipt_addr;
163 			n_long ipt_time;
164 		} ipt_ta[1];
165 	} ipt_timestamp;
166 };
167 
168 /* flag bits for ipt_flg */
169 #define	IPOPT_TS_TSONLY		0		/* timestamps only */
170 #define	IPOPT_TS_TSANDADDR	1		/* timestamps and addresses */
171 #define	IPOPT_TS_PRESPEC	3		/* specified modules only */
172 
173 /* bits for security (not byte swapped) */
174 #define	IPOPT_SECUR_UNCLASS	0x0000
175 #define	IPOPT_SECUR_CONFID	0xf135
176 #define	IPOPT_SECUR_EFTO	0x789a
177 #define	IPOPT_SECUR_MMMM	0xbc4d
178 #define	IPOPT_SECUR_RESTR	0xaf13
179 #define	IPOPT_SECUR_SECRET	0xd788
180 #define	IPOPT_SECUR_TOPSECRET	0x6bc5
181 
182 /*
183  * Internet implementation parameters.
184  */
185 #define	MAXTTL		255		/* maximum time to live (seconds) */
186 #define	IPDEFTTL	64		/* default ttl, from RFC 1340 */
187 #define	IPFRAGTTL	60		/* time to live for frags, slowhz */
188 #define	IPTTLDEC	1		/* subtracted when forwarding */
189 
190 #define	IP_MSS		576		/* default maximum segment size */
191 
192 /*
193  * This is the real IPv4 pseudo header, used for computing the TCP and UDP
194  * checksums. For the Internet checksum, struct ipovly can be used instead.
195  * For stronger checksums, the real thing must be used.
196  */
197 struct ippseudo {
198 	struct	in_addr	ippseudo_src;	/* source internet address */
199 	struct	in_addr	ippseudo_dst;	/* destination internet address */
200 	u_char		ippseudo_pad;	/* pad, must be zero */
201 	u_char		ippseudo_p;	/* protocol */
202 	u_short		ippseudo_len;	/* protocol length */
203 };
204 #endif
205