xref: /freebsd/sys/netinet/ip.h (revision 3193579b66fd7067f898dbc54bdea81a0e6f9bd0)
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  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  *	@(#)ip.h	8.2 (Berkeley) 6/1/94
34  * $FreeBSD$
35  */
36 
37 #ifndef _NETINET_IP_H_
38 #define _NETINET_IP_H_
39 
40 #include <sys/cdefs.h>
41 
42 /*
43  * Definitions for internet protocol version 4.
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_int	ip_hl:4,		/* header length */
54 		ip_v:4;			/* version */
55 #endif
56 #if BYTE_ORDER == BIG_ENDIAN
57 	u_int	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;
73 
74 #ifdef CTASSERT
75 CTASSERT(sizeof (struct ip) == 20);
76 #endif
77 
78 #define	IP_MAXPACKET	65535		/* maximum packet size */
79 
80 /*
81  * Definitions for IP type of service (ip_tos)
82  */
83 #define	IPTOS_LOWDELAY		0x10
84 #define	IPTOS_THROUGHPUT	0x08
85 #define	IPTOS_RELIABILITY	0x04
86 #define	IPTOS_MINCOST		0x02
87 #if 1
88 /* ECN RFC3168 obsoletes RFC2481, and these will be deprecated soon. */
89 #define	IPTOS_CE		0x01
90 #define	IPTOS_ECT		0x02
91 #endif
92 
93 /*
94  * Definitions for IP precedence (also in ip_tos) (hopefully unused)
95  */
96 #define	IPTOS_PREC_NETCONTROL		0xe0
97 #define	IPTOS_PREC_INTERNETCONTROL	0xc0
98 #define	IPTOS_PREC_CRITIC_ECP		0xa0
99 #define	IPTOS_PREC_FLASHOVERRIDE	0x80
100 #define	IPTOS_PREC_FLASH		0x60
101 #define	IPTOS_PREC_IMMEDIATE		0x40
102 #define	IPTOS_PREC_PRIORITY		0x20
103 #define	IPTOS_PREC_ROUTINE		0x00
104 
105 /*
106  * ECN (Explicit Congestion Notification) codepoints in RFC3168
107  * mapped to the lower 2 bits of the TOS field.
108  */
109 #define	IPTOS_ECN_NOTECT	0x00	/* not-ECT */
110 #define	IPTOS_ECN_ECT1		0x01	/* ECN-capable transport (1) */
111 #define	IPTOS_ECN_ECT0		0x02	/* ECN-capable transport (0) */
112 #define	IPTOS_ECN_CE		0x03	/* congestion experienced */
113 #define	IPTOS_ECN_MASK		0x03	/* ECN field mask */
114 
115 /*
116  * Definitions for options.
117  */
118 #define	IPOPT_COPIED(o)		((o)&0x80)
119 #define	IPOPT_CLASS(o)		((o)&0x60)
120 #define	IPOPT_NUMBER(o)		((o)&0x1f)
121 
122 #define	IPOPT_CONTROL		0x00
123 #define	IPOPT_RESERVED1		0x20
124 #define	IPOPT_DEBMEAS		0x40
125 #define	IPOPT_RESERVED2		0x60
126 
127 #define	IPOPT_EOL		0		/* end of option list */
128 #define	IPOPT_NOP		1		/* no operation */
129 
130 #define	IPOPT_RR		7		/* record packet route */
131 #define	IPOPT_TS		68		/* timestamp */
132 #define	IPOPT_SECURITY		130		/* provide s,c,h,tcc */
133 #define	IPOPT_LSRR		131		/* loose source route */
134 #define	IPOPT_ESO		133		/* extended security */
135 #define	IPOPT_CIPSO		134		/* commerical security */
136 #define	IPOPT_SATID		136		/* satnet id */
137 #define	IPOPT_SSRR		137		/* strict source route */
138 #define	IPOPT_RA		148		/* router alert */
139 
140 /*
141  * Offsets to fields in options other than EOL and NOP.
142  */
143 #define	IPOPT_OPTVAL		0		/* option ID */
144 #define	IPOPT_OLEN		1		/* option length */
145 #define IPOPT_OFFSET		2		/* offset within option */
146 #define	IPOPT_MINOFF		4		/* min value of above */
147 
148 /*
149  * Time stamp option structure.
150  */
151 struct	ip_timestamp {
152 	u_char	ipt_code;		/* IPOPT_TS */
153 	u_char	ipt_len;		/* size of structure (variable) */
154 	u_char	ipt_ptr;		/* index of current entry */
155 #if BYTE_ORDER == LITTLE_ENDIAN
156 	u_int	ipt_flg:4,		/* flags, see below */
157 		ipt_oflw:4;		/* overflow counter */
158 #endif
159 #if BYTE_ORDER == BIG_ENDIAN
160 	u_int	ipt_oflw:4,		/* overflow counter */
161 		ipt_flg:4;		/* flags, see below */
162 #endif
163 	union ipt_timestamp {
164 		n_long	ipt_time[1];
165 		struct	ipt_ta {
166 			struct in_addr ipt_addr;
167 			n_long ipt_time;
168 		} ipt_ta[1];
169 	} ipt_timestamp;
170 };
171 
172 /* flag bits for ipt_flg */
173 #define	IPOPT_TS_TSONLY		0		/* timestamps only */
174 #define	IPOPT_TS_TSANDADDR	1		/* timestamps and addresses */
175 #define	IPOPT_TS_PRESPEC	3		/* specified modules only */
176 
177 /* bits for security (not byte swapped) */
178 #define	IPOPT_SECUR_UNCLASS	0x0000
179 #define	IPOPT_SECUR_CONFID	0xf135
180 #define	IPOPT_SECUR_EFTO	0x789a
181 #define	IPOPT_SECUR_MMMM	0xbc4d
182 #define	IPOPT_SECUR_RESTR	0xaf13
183 #define	IPOPT_SECUR_SECRET	0xd788
184 #define	IPOPT_SECUR_TOPSECRET	0x6bc5
185 
186 /*
187  * Internet implementation parameters.
188  */
189 #define	MAXTTL		255		/* maximum time to live (seconds) */
190 #define	IPDEFTTL	64		/* default ttl, from RFC 1340 */
191 #define	IPFRAGTTL	60		/* time to live for frags, slowhz */
192 #define	IPTTLDEC	1		/* subtracted when forwarding */
193 
194 #define	IP_MSS		576		/* default maximum segment size */
195 
196 #endif
197