xref: /netbsd-src/sys/netinet/ip.h (revision b757af438b42b93f8c6571f026d8b8ef3eaf5fc9)
1 /*	$NetBSD: ip.h,v 1.32 2011/07/24 18:06:08 christos Exp $	*/
2 
3 /*
4  * Copyright (c) 1982, 1986, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  *	@(#)ip.h	8.2 (Berkeley) 6/1/94
32  */
33 
34 #ifndef _NETINET_IP_H_
35 #define _NETINET_IP_H_
36 
37 /*
38  * Definitions for internet protocol version 4.
39  * Per RFC 791, September 1981.
40  */
41 #define	IPVERSION	4
42 
43 /*
44  * Structure of an internet header, naked of options.
45  */
46 struct ip {
47 #if BYTE_ORDER == LITTLE_ENDIAN
48 	unsigned int ip_hl:4,		/* header length */
49 		     ip_v:4;		/* version */
50 #endif
51 #if BYTE_ORDER == BIG_ENDIAN
52 	unsigned int ip_v:4,		/* version */
53 		     ip_hl:4;		/* header length */
54 #endif
55 	u_int8_t  ip_tos;		/* type of service */
56 	u_int16_t ip_len;		/* total length */
57 	u_int16_t ip_id;		/* identification */
58 	u_int16_t ip_off;		/* fragment offset field */
59 #define	IP_RF 0x8000			/* reserved fragment flag */
60 #define	IP_EF 0x8000			/* evil flag, per RFC 3514 */
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_int8_t  ip_ttl;		/* time to live */
65 	u_int8_t  ip_p;			/* protocol */
66 	u_int16_t ip_sum;		/* checksum */
67 	struct	  in_addr ip_src, ip_dst; /* source and dest address */
68 } __packed;
69 
70 #define	IP_MAXPACKET	65535		/* maximum packet size */
71 #define	IP_MINFRAGSIZE	69		/* minumum size that can be fraged */
72 
73 /*
74  * Definitions for IP type of service (ip_tos)
75  */
76 
77 /*
78  * Definitions for DiffServ Codepoints as per RFC2474
79  */
80 #define	IPTOS_DSCP_CS0		0x00
81 #define	IPTOS_DSCP_CS1		0x20
82 #define	IPTOS_DSCP_AF11		0x28
83 #define	IPTOS_DSCP_AF12		0x30
84 #define	IPTOS_DSCP_AF13		0x38
85 #define	IPTOS_DSCP_CS2		0x40
86 #define	IPTOS_DSCP_AF21		0x48
87 #define	IPTOS_DSCP_AF22		0x50
88 #define	IPTOS_DSCP_AF23		0x58
89 #define	IPTOS_DSCP_CS3		0x60
90 #define	IPTOS_DSCP_AF31		0x68
91 #define	IPTOS_DSCP_AF32		0x70
92 #define	IPTOS_DSCP_AF33		0x78
93 #define	IPTOS_DSCP_CS4		0x80
94 #define	IPTOS_DSCP_AF41		0x88
95 #define	IPTOS_DSCP_AF42		0x90
96 #define	IPTOS_DSCP_AF43		0x98
97 #define	IPTOS_DSCP_CS5		0xa0
98 #define	IPTOS_DSCP_EF		0xb8
99 #define	IPTOS_DSCP_CS6		0xc0
100 #define	IPTOS_DSCP_CS7		0xe0
101 
102 /*
103  * Definitions for DiffServ Class Selector Codepoints
104  */
105 #define	IPTOS_CLASS_CS0		0x00
106 #define	IPTOS_CLASS_CS1		0x20
107 #define	IPTOS_CLASS_CS2		0x40
108 #define	IPTOS_CLASS_CS3		0x60
109 #define	IPTOS_CLASS_CS4		0x80
110 #define	IPTOS_CLASS_CS5		0xa0
111 #define	IPTOS_CLASS_CS6		0xc0
112 #define	IPTOS_CLASS_CS7		0xe0
113 #define	IPTOS_CLASS_DEFAULT	IPTOS_CLASS_CS0
114 #define	IPTOS_CLASS_MASK	0xe0
115 #define	IPTOS_CLASS(cs)		((cs) & IPTOS_CLASS_MASK)
116 #define	IPTOS_DSCP_MASK		0xfc
117 #define	IPTOS_DSCP(cp)		((cp) & IPTOS_DSCP_MASK)
118 
119 /*
120  * ECN (Explicit Congestion Notification) codepoints in RFC3168
121  * mapped to the lower 2 bits of the TOS field.
122  */
123 #define	IPTOS_ECN_NOTECT	0x00	/* not-ECT */
124 #define	IPTOS_ECN_ECT1		0x01	/* ECN-capable transport (1) */
125 #define	IPTOS_ECN_ECT0		0x02	/* ECN-capable transport (0) */
126 #define	IPTOS_ECN_CE		0x03	/* congestion experienced */
127 #define	IPTOS_ECN_MASK		0x03	/* ECN field mask */
128 #define	IPTOS_ECN(cn)		((cn) & IPTOS_ECN_MASK)
129 #define	IPTOS_ECN_NOT_ECT	0x00
130 
131 /*
132  * Definitions for IP type of service per RFC1349 (ip_tos)
133  * DEPRECATED
134  */
135 #define	IPTOS_LOWDELAY		0x10
136 #define	IPTOS_THROUGHPUT	0x08
137 #define	IPTOS_RELIABILITY	0x04
138 #define	IPTOS_MINCOST		0x02
139 /* ECN RFC3168 obsoletes RFC2481, and these will be deprecated soon. */
140 #define	IPTOS_CE		0x01	/* congestion experienced */
141 #define	IPTOS_ECT		0x02	/* ECN-capable transport */
142 
143 /*
144  * Definitions for IP precedence per RFC1195 (also in ip_tos) (hopefully unused)
145  */
146 #define	IPTOS_PREC_NETCONTROL		0xe0
147 #define	IPTOS_PREC_INTERNETCONTROL	0xc0
148 #define	IPTOS_PREC_CRITIC_ECP		0xa0
149 #define	IPTOS_PREC_FLASHOVERRIDE	0x80
150 #define	IPTOS_PREC_FLASH		0x60
151 #define	IPTOS_PREC_IMMEDIATE		0x40
152 #define	IPTOS_PREC_PRIORITY		0x20
153 #define	IPTOS_PREC_ROUTINE		0x00
154 
155 /*
156  * Definitions for options.
157  */
158 #define	IPOPT_COPIED(o)		((o)&0x80)
159 #define	IPOPT_CLASS(o)		((o)&0x60)
160 #define	IPOPT_NUMBER(o)		((o)&0x1f)
161 
162 #define	IPOPT_CONTROL		0x00
163 #define	IPOPT_RESERVED1		0x20
164 #define	IPOPT_DEBMEAS		0x40
165 #define	IPOPT_RESERVED2		0x60
166 
167 #define	IPOPT_EOL		0		/* end of option list */
168 #define	IPOPT_NOP		1		/* no operation */
169 
170 #define	IPOPT_RR		7		/* record packet route */
171 #define	IPOPT_TS		68		/* timestamp */
172 #define	IPOPT_SECURITY		130		/* provide s,c,h,tcc */
173 #define	IPOPT_LSRR		131		/* loose source route */
174 #define	IPOPT_SATID		136		/* satnet id */
175 #define	IPOPT_SSRR		137		/* strict source route */
176 
177 /*
178  * Offsets to fields in options other than EOL and NOP.
179  */
180 #define	IPOPT_OPTVAL		0		/* option ID */
181 #define	IPOPT_OLEN		1		/* option length */
182 #define	IPOPT_OFFSET		2		/* offset within option */
183 #define	IPOPT_MINOFF		4		/* min value of above */
184 
185 /*
186  * Time stamp option structure.
187  */
188 struct	ip_timestamp {
189 	u_int8_t ipt_code;		/* IPOPT_TS */
190 	u_int8_t ipt_len;		/* size of structure (variable) */
191 	u_int8_t ipt_ptr;		/* index of current entry */
192 #if BYTE_ORDER == LITTLE_ENDIAN
193 	unsigned int ipt_flg:4,		/* flags, see below */
194 		     ipt_oflw:4;	/* overflow counter */
195 #endif
196 #if BYTE_ORDER == BIG_ENDIAN
197 	unsigned int ipt_oflw:4,	/* overflow counter */
198 		     ipt_flg:4;		/* flags, see below */
199 #endif
200 	union ipt_timestamp {
201 		 n_time	ipt_time[1];
202 		 struct	ipt_ta {
203 			struct in_addr ipt_addr;
204 			n_time ipt_time;
205 		 } ipt_ta[1] __packed;
206 	} ipt_timestamp __packed;
207 } __packed;
208 
209 /* flag bits for ipt_flg */
210 #define	IPOPT_TS_TSONLY		0		/* timestamps only */
211 #define	IPOPT_TS_TSANDADDR	1		/* timestamps and addresses */
212 #define	IPOPT_TS_PRESPEC	3		/* specified modules only */
213 
214 /* bits for security (not byte swapped) */
215 #define	IPOPT_SECUR_UNCLASS	0x0000
216 #define	IPOPT_SECUR_CONFID	0xf135
217 #define	IPOPT_SECUR_EFTO	0x789a
218 #define	IPOPT_SECUR_MMMM	0xbc4d
219 #define	IPOPT_SECUR_RESTR	0xaf13
220 #define	IPOPT_SECUR_SECRET	0xd788
221 #define	IPOPT_SECUR_TOPSECRET	0x6bc5
222 
223 /*
224  * Internet implementation parameters.
225  */
226 #define	MAXTTL		255		/* maximum time to live (seconds) */
227 #define	IPDEFTTL	64		/* default ttl, from RFC 1340 */
228 #define	IPFRAGTTL	60		/* time to live for frags, slowhz */
229 #define	IPTTLDEC	1		/* subtracted when forwarding */
230 
231 #define	IP_MSS		576		/* default maximum segment size */
232 
233 /*
234  * This is the real IPv4 pseudo header, used for computing the TCP and UDP
235  * checksums. For the Internet checksum, struct ipovly can be used instead.
236  * For stronger checksums, the real thing must be used.
237  */
238 struct ippseudo {
239 	struct	in_addr	ippseudo_src;	/* source internet address */
240 	struct	in_addr	ippseudo_dst;	/* destination internet address */
241 	u_int8_t	ippseudo_pad;	/* pad, must be zero */
242 	u_int8_t	ippseudo_p;	/* protocol */
243 	u_int16_t	ippseudo_len;	/* protocol length */
244 } __packed;
245 #endif /* !_NETINET_IP_H_ */
246