xref: /netbsd/sys/netinet/ip.h (revision bcbc1fcf)
1 /*	$NetBSD: ip.h,v 1.39 2022/04/17 21:24:53 andvar 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 #include <sys/types.h>
38 
39 #include <netinet/in.h>
40 #include <netinet/in_systm.h>	/* for n_time */
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 	unsigned int ip_hl:4,		/* header length */
54 		     ip_v:4;		/* version */
55 #endif
56 #if BYTE_ORDER == BIG_ENDIAN
57 	unsigned int ip_v:4,		/* version */
58 		     ip_hl:4;		/* header length */
59 #endif
60 	u_int8_t  ip_tos;		/* type of service */
61 	u_int16_t ip_len;		/* total length */
62 	u_int16_t ip_id;		/* identification */
63 	u_int16_t ip_off;		/* fragment offset field */
64 #define	IP_RF 0x8000			/* reserved fragment flag */
65 #define	IP_EF 0x8000			/* evil flag, per RFC 3514 */
66 #define	IP_DF 0x4000			/* dont fragment flag */
67 #define	IP_MF 0x2000			/* more fragments flag */
68 #define	IP_OFFMASK 0x1fff		/* mask for fragmenting bits */
69 	u_int8_t  ip_ttl;		/* time to live */
70 	u_int8_t  ip_p;			/* protocol */
71 	u_int16_t ip_sum;		/* checksum */
72 	struct	  in_addr ip_src, ip_dst; /* source and dest address */
73 };
74 
75 #define	IP_MAXPACKET	65535		/* maximum packet size */
76 #define	IP_MINFRAGSIZE	69		/* minimum size that can be fraged */
77 
78 /*
79  * Definitions for IP type of service (ip_tos)
80  */
81 
82 /*
83  * Definitions for DiffServ Codepoints as per RFC2474
84  */
85 #define	IPTOS_DSCP_CS0		0x00
86 #define	IPTOS_DSCP_CS1		0x20
87 #define	IPTOS_DSCP_AF11		0x28
88 #define	IPTOS_DSCP_AF12		0x30
89 #define	IPTOS_DSCP_AF13		0x38
90 #define	IPTOS_DSCP_CS2		0x40
91 #define	IPTOS_DSCP_AF21		0x48
92 #define	IPTOS_DSCP_AF22		0x50
93 #define	IPTOS_DSCP_AF23		0x58
94 #define	IPTOS_DSCP_CS3		0x60
95 #define	IPTOS_DSCP_AF31		0x68
96 #define	IPTOS_DSCP_AF32		0x70
97 #define	IPTOS_DSCP_AF33		0x78
98 #define	IPTOS_DSCP_CS4		0x80
99 #define	IPTOS_DSCP_AF41		0x88
100 #define	IPTOS_DSCP_AF42		0x90
101 #define	IPTOS_DSCP_AF43		0x98
102 #define	IPTOS_DSCP_CS5		0xa0
103 #define	IPTOS_DSCP_EF		0xb8
104 #define	IPTOS_DSCP_CS6		0xc0
105 #define	IPTOS_DSCP_CS7		0xe0
106 
107 /*
108  * Definitions for DiffServ Class Selector Codepoints
109  */
110 #define	IPTOS_CLASS_CS0		0x00
111 #define	IPTOS_CLASS_CS1		0x20
112 #define	IPTOS_CLASS_CS2		0x40
113 #define	IPTOS_CLASS_CS3		0x60
114 #define	IPTOS_CLASS_CS4		0x80
115 #define	IPTOS_CLASS_CS5		0xa0
116 #define	IPTOS_CLASS_CS6		0xc0
117 #define	IPTOS_CLASS_CS7		0xe0
118 #define	IPTOS_CLASS_DEFAULT	IPTOS_CLASS_CS0
119 #define	IPTOS_CLASS_MASK	0xe0
120 #define	IPTOS_CLASS(cs)		((cs) & IPTOS_CLASS_MASK)
121 #define	IPTOS_DSCP_MASK		0xfc
122 #define	IPTOS_DSCP(cp)		((cp) & IPTOS_DSCP_MASK)
123 
124 /*
125  * ECN (Explicit Congestion Notification) codepoints in RFC3168
126  * mapped to the lower 2 bits of the TOS field.
127  */
128 #define	IPTOS_ECN_NOTECT	0x00	/* not-ECT */
129 #define	IPTOS_ECN_ECT1		0x01	/* ECN-capable transport (1) */
130 #define	IPTOS_ECN_ECT0		0x02	/* ECN-capable transport (0) */
131 #define	IPTOS_ECN_CE		0x03	/* congestion experienced */
132 #define	IPTOS_ECN_MASK		0x03	/* ECN field mask */
133 #define	IPTOS_ECN(cn)		((cn) & IPTOS_ECN_MASK)
134 #define	IPTOS_ECN_NOT_ECT	0x00
135 
136 /*
137  * Definitions for IP type of service per RFC1349 (ip_tos)
138  * DEPRECATED
139  */
140 #define	IPTOS_LOWDELAY		0x10
141 #define	IPTOS_THROUGHPUT	0x08
142 #define	IPTOS_RELIABILITY	0x04
143 #define	IPTOS_MINCOST		0x02
144 /* ECN RFC3168 obsoletes RFC2481, and these will be deprecated soon. */
145 #define	IPTOS_CE		0x01	/* congestion experienced */
146 #define	IPTOS_ECT		0x02	/* ECN-capable transport */
147 
148 /*
149  * Definitions for IP precedence per RFC1195 (also in ip_tos) (hopefully unused)
150  */
151 #define	IPTOS_PREC_NETCONTROL		0xe0
152 #define	IPTOS_PREC_INTERNETCONTROL	0xc0
153 #define	IPTOS_PREC_CRITIC_ECP		0xa0
154 #define	IPTOS_PREC_FLASHOVERRIDE	0x80
155 #define	IPTOS_PREC_FLASH		0x60
156 #define	IPTOS_PREC_IMMEDIATE		0x40
157 #define	IPTOS_PREC_PRIORITY		0x20
158 #define	IPTOS_PREC_ROUTINE		0x00
159 
160 /*
161  * Definitions for options.
162  */
163 #define	IPOPT_COPIED(o)		((o)&0x80)
164 #define	IPOPT_CLASS(o)		((o)&0x60)
165 #define	IPOPT_NUMBER(o)		((o)&0x1f)
166 
167 #define	IPOPT_CONTROL		0x00
168 #define	IPOPT_RESERVED1		0x20
169 #define	IPOPT_DEBMEAS		0x40
170 #define	IPOPT_RESERVED2		0x60
171 
172 #define	IPOPT_EOL		0		/* end of option list */
173 #define	IPOPT_NOP		1		/* no operation */
174 
175 #define	IPOPT_RR		7		/* record packet route */
176 #define	IPOPT_TS		68		/* timestamp */
177 #define	IPOPT_SECURITY		130		/* provide s,c,h,tcc */
178 #define	IPOPT_LSRR		131		/* loose source route */
179 #define	IPOPT_SATID		136		/* satnet id */
180 #define	IPOPT_SSRR		137		/* strict source route */
181 
182 /*
183  * Offsets to fields in options other than EOL and NOP.
184  */
185 #define	IPOPT_OPTVAL		0		/* option ID */
186 #define	IPOPT_OLEN		1		/* option length */
187 #define	IPOPT_OFFSET		2		/* offset within option */
188 #define	IPOPT_MINOFF		4		/* min value of above */
189 
190 /*
191  * Time stamp option structure.
192  */
193 struct	ip_timestamp {
194 	u_int8_t ipt_code;		/* IPOPT_TS */
195 	u_int8_t ipt_len;		/* size of structure (variable) */
196 	u_int8_t ipt_ptr;		/* index of current entry */
197 #if BYTE_ORDER == LITTLE_ENDIAN
198 	unsigned int ipt_flg:4,		/* flags, see below */
199 		     ipt_oflw:4;	/* overflow counter */
200 #endif
201 #if BYTE_ORDER == BIG_ENDIAN
202 	unsigned int ipt_oflw:4,	/* overflow counter */
203 		     ipt_flg:4;		/* flags, see below */
204 #endif
205 	union ipt_timestamp {
206 		 n_time	ipt_time[1];
207 		 struct	ipt_ta {
208 			struct in_addr ipt_addr;
209 			n_time ipt_time;
210 		 } ipt_ta[1];
211 	} ipt_timestamp;
212 };
213 
214 /* flag bits for ipt_flg */
215 #define	IPOPT_TS_TSONLY		0		/* timestamps only */
216 #define	IPOPT_TS_TSANDADDR	1		/* timestamps and addresses */
217 #define	IPOPT_TS_PRESPEC	3		/* specified modules only */
218 
219 /* bits for security (not byte swapped) */
220 #define	IPOPT_SECUR_UNCLASS	0x0000
221 #define	IPOPT_SECUR_CONFID	0xf135
222 #define	IPOPT_SECUR_EFTO	0x789a
223 #define	IPOPT_SECUR_MMMM	0xbc4d
224 #define	IPOPT_SECUR_RESTR	0xaf13
225 #define	IPOPT_SECUR_SECRET	0xd788
226 #define	IPOPT_SECUR_TOPSECRET	0x6bc5
227 
228 /*
229  * Internet implementation parameters.
230  */
231 #define	MAXTTL		255		/* maximum time to live (seconds) */
232 #define	IPDEFTTL	64		/* default ttl, from RFC 1340 */
233 #define	IPFRAGTTL	60		/* time to live for frags, slowhz */
234 #define	IPTTLDEC	1		/* subtracted when forwarding */
235 
236 #define	IP_MSS		576		/* default maximum segment size */
237 
238 /*
239  * This is the real IPv4 pseudo header, used for computing the TCP and UDP
240  * checksums. For the Internet checksum, struct ipovly can be used instead.
241  * For stronger checksums, the real thing must be used.
242  */
243 struct ippseudo {
244 	struct	in_addr	ippseudo_src;	/* source internet address */
245 	struct	in_addr	ippseudo_dst;	/* destination internet address */
246 	u_int8_t	ippseudo_pad;	/* pad, must be zero */
247 	u_int8_t	ippseudo_p;	/* protocol */
248 	u_int16_t	ippseudo_len;	/* protocol length */
249 };
250 
251 #ifdef __CTASSERT
252 __CTASSERT(sizeof(struct ip) == 20);
253 __CTASSERT(sizeof(struct ip_timestamp) == 12);
254 __CTASSERT(sizeof(struct ippseudo) == 12);
255 #endif
256 
257 #endif	/* !_NETINET_IP_H_ */
258