xref: /freebsd/sys/netinet/ip.h (revision 282a3889ebf826db9839be296ff1dd903f6d6d6e)
1 /*-
2  * Copyright (c) 1982, 1986, 1993
3  *	The Regents of the University of California.
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 4. Neither the name of the University nor the names of its contributors
15  *    may be used to endorse or promote products derived from this software
16  *    without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  *
30  *	@(#)ip.h	8.2 (Berkeley) 6/1/94
31  * $FreeBSD$
32  */
33 
34 #ifndef _NETINET_IP_H_
35 #define	_NETINET_IP_H_
36 
37 #include <sys/cdefs.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_int	ip_hl:4,		/* header length */
52 		ip_v:4;			/* version */
53 #endif
54 #if BYTE_ORDER == BIG_ENDIAN
55 	u_int	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 __aligned(4);
71 
72 #ifdef CTASSERT
73 CTASSERT(sizeof (struct ip) == 20);
74 #endif
75 
76 #define	IP_MAXPACKET	65535		/* maximum packet size */
77 
78 /*
79  * Definitions for IP type of service (ip_tos).
80  */
81 #define	IPTOS_LOWDELAY		0x10
82 #define	IPTOS_THROUGHPUT	0x08
83 #define	IPTOS_RELIABILITY	0x04
84 #define	IPTOS_MINCOST		0x02
85 #if 1
86 /* ECN RFC3168 obsoletes RFC2481, and these will be deprecated soon. */
87 #define	IPTOS_CE		0x01
88 #define	IPTOS_ECT		0x02
89 #endif
90 
91 /*
92  * Definitions for IP precedence (also in ip_tos) (hopefully unused).
93  */
94 #define	IPTOS_PREC_NETCONTROL		0xe0
95 #define	IPTOS_PREC_INTERNETCONTROL	0xc0
96 #define	IPTOS_PREC_CRITIC_ECP		0xa0
97 #define	IPTOS_PREC_FLASHOVERRIDE	0x80
98 #define	IPTOS_PREC_FLASH		0x60
99 #define	IPTOS_PREC_IMMEDIATE		0x40
100 #define	IPTOS_PREC_PRIORITY		0x20
101 #define	IPTOS_PREC_ROUTINE		0x00
102 
103 /*
104  * ECN (Explicit Congestion Notification) codepoints in RFC3168 mapped to the
105  * lower 2 bits of the TOS field.
106  */
107 #define	IPTOS_ECN_NOTECT	0x00	/* not-ECT */
108 #define	IPTOS_ECN_ECT1		0x01	/* ECN-capable transport (1) */
109 #define	IPTOS_ECN_ECT0		0x02	/* ECN-capable transport (0) */
110 #define	IPTOS_ECN_CE		0x03	/* congestion experienced */
111 #define	IPTOS_ECN_MASK		0x03	/* ECN field mask */
112 
113 /*
114  * Definitions for options.
115  */
116 #define	IPOPT_COPIED(o)		((o)&0x80)
117 #define	IPOPT_CLASS(o)		((o)&0x60)
118 #define	IPOPT_NUMBER(o)		((o)&0x1f)
119 
120 #define	IPOPT_CONTROL		0x00
121 #define	IPOPT_RESERVED1		0x20
122 #define	IPOPT_DEBMEAS		0x40
123 #define	IPOPT_RESERVED2		0x60
124 
125 #define	IPOPT_EOL		0		/* end of option list */
126 #define	IPOPT_NOP		1		/* no operation */
127 
128 #define	IPOPT_RR		7		/* record packet route */
129 #define	IPOPT_TS		68		/* timestamp */
130 #define	IPOPT_SECURITY		130		/* provide s,c,h,tcc */
131 #define	IPOPT_LSRR		131		/* loose source route */
132 #define	IPOPT_ESO		133		/* extended security */
133 #define	IPOPT_CIPSO		134		/* commerical security */
134 #define	IPOPT_SATID		136		/* satnet id */
135 #define	IPOPT_SSRR		137		/* strict source route */
136 #define	IPOPT_RA		148		/* router alert */
137 
138 /*
139  * Offsets to fields in options other than EOL and NOP.
140  */
141 #define	IPOPT_OPTVAL		0		/* option ID */
142 #define	IPOPT_OLEN		1		/* option length */
143 #define	IPOPT_OFFSET		2		/* offset within option */
144 #define	IPOPT_MINOFF		4		/* min value of above */
145 
146 /*
147  * Time stamp option structure.
148  */
149 struct	ip_timestamp {
150 	u_char	ipt_code;		/* IPOPT_TS */
151 	u_char	ipt_len;		/* size of structure (variable) */
152 	u_char	ipt_ptr;		/* index of current entry */
153 #if BYTE_ORDER == LITTLE_ENDIAN
154 	u_int	ipt_flg:4,		/* flags, see below */
155 		ipt_oflw:4;		/* overflow counter */
156 #endif
157 #if BYTE_ORDER == BIG_ENDIAN
158 	u_int	ipt_oflw:4,		/* overflow counter */
159 		ipt_flg:4;		/* flags, see below */
160 #endif
161 	union ipt_timestamp {
162 		n_long	ipt_time[1];
163 		struct	ipt_ta {
164 			struct in_addr ipt_addr;
165 			n_long ipt_time;
166 		} ipt_ta[1];
167 	} ipt_timestamp;
168 };
169 
170 /* Flag bits for ipt_flg. */
171 #define	IPOPT_TS_TSONLY		0		/* timestamps only */
172 #define	IPOPT_TS_TSANDADDR	1		/* timestamps and addresses */
173 #define	IPOPT_TS_PRESPEC	3		/* specified modules only */
174 
175 /* Bits for security (not byte swapped). */
176 #define	IPOPT_SECUR_UNCLASS	0x0000
177 #define	IPOPT_SECUR_CONFID	0xf135
178 #define	IPOPT_SECUR_EFTO	0x789a
179 #define	IPOPT_SECUR_MMMM	0xbc4d
180 #define	IPOPT_SECUR_RESTR	0xaf13
181 #define	IPOPT_SECUR_SECRET	0xd788
182 #define	IPOPT_SECUR_TOPSECRET	0x6bc5
183 
184 /*
185  * Internet implementation parameters.
186  */
187 #define	MAXTTL		255		/* maximum time to live (seconds) */
188 #define	IPDEFTTL	64		/* default ttl, from RFC 1340 */
189 #define	IPFRAGTTL	60		/* time to live for frags, slowhz */
190 #define	IPTTLDEC	1		/* subtracted when forwarding */
191 #define	IP_MSS		576		/* default maximum segment size */
192 
193 /*
194  * This is the real IPv4 pseudo header, used for computing the TCP and UDP
195  * checksums. For the Internet checksum, struct ipovly can be used instead.
196  * For stronger checksums, the real thing must be used.
197  */
198 struct ippseudo {
199 	struct	in_addr	ippseudo_src;	/* source internet address */
200 	struct	in_addr	ippseudo_dst;	/* destination internet address */
201 	u_char		ippseudo_pad;	/* pad, must be zero */
202 	u_char		ippseudo_p;	/* protocol */
203 	u_short		ippseudo_len;	/* protocol length */
204 };
205 #endif
206