1 /*	$OpenBSD: ip.h,v 1.12 2006/04/27 02:19:32 tedu Exp $	*/
2 /*	$NetBSD: ip.h,v 1.9 1995/05/15 01:22:44 cgd Exp $	*/
3 
4 /*
5  * Copyright (c) 1982, 1986, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  *
32  *	@(#)ip.h	8.1 (Berkeley) 6/10/93
33  */
34 
35 #ifndef _NETINET_IP_H_
36 #define _NETINET_IP_H_
37 
38 #include <sys/cdefs.h>
39 #include <sys/types.h>
40 #include <endian.h>
41 #include <netinet/in.h>
42 #include <netinet/in_systm.h>
43 
44 __BEGIN_DECLS
45 
46 /*
47  * Definitions for internet protocol version 4.
48  * Per RFC 791, September 1981.
49  */
50 #define	IPVERSION	4
51 
52 /*
53  * Structure of an internet header, naked of options.
54  */
55 struct ip {
56 	u_int32_t ip_hl:4,		/* header length */
57 		  ip_v:4;		/* version */
58 	u_int8_t  ip_tos;		/* type of service */
59 	u_int16_t ip_len;		/* total length */
60 	u_int16_t ip_id;		/* identification */
61 	u_int16_t 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_int8_t  ip_ttl;		/* time to live */
67 	u_int8_t  ip_p;			/* protocol */
68 	u_int16_t ip_sum;		/* checksum */
69 	struct	  in_addr ip_src, ip_dst; /* source and dest address */
70 };
71 
72 #define	IP_MAXPACKET	65535		/* maximum packet size */
73 
74 /*
75  * Definitions for IP type of service (ip_tos)
76  */
77 #define	IPTOS_LOWDELAY		0x10
78 #define	IPTOS_THROUGHPUT	0x08
79 #define	IPTOS_RELIABILITY	0x04
80 #define	IPTOS_MINCOST		0x02
81 #if 1
82 /* ECN RFC3168 obsoletes RFC2481, and these will be deprecated soon. */
83 #define IPTOS_CE		0x01	/* congestion experienced */
84 #define IPTOS_ECT		0x02	/* ECN-capable transport */
85 #endif
86 
87 /*
88  * Definitions for IP precedence (also in ip_tos) (hopefully unused)
89  */
90 #define	IPTOS_PREC_NETCONTROL		0xe0
91 #define	IPTOS_PREC_INTERNETCONTROL	0xc0
92 #define	IPTOS_PREC_CRITIC_ECP		0xa0
93 #define	IPTOS_PREC_FLASHOVERRIDE	0x80
94 #define	IPTOS_PREC_FLASH		0x60
95 #define	IPTOS_PREC_IMMEDIATE		0x40
96 #define	IPTOS_PREC_PRIORITY		0x20
97 #define	IPTOS_PREC_ROUTINE		0x00
98 
99 /*
100  * ECN (Explicit Congestion Notification) codepoints in RFC3168
101  * mapped to the lower 2 bits of the TOS field.
102  */
103 #define	IPTOS_ECN_NOTECT	0x00	/* not-ECT */
104 #define	IPTOS_ECN_ECT1		0x01	/* ECN-capable transport (1) */
105 #define	IPTOS_ECN_ECT0		0x02	/* ECN-capable transport (0) */
106 #define	IPTOS_ECN_CE		0x03	/* congestion experienced */
107 #define	IPTOS_ECN_MASK		0x03	/* ECN field mask */
108 
109 /*
110  * Definitions for options.
111  */
112 #define	IPOPT_COPIED(o)		((o)&0x80)
113 #define	IPOPT_CLASS(o)		((o)&0x60)
114 #define	IPOPT_NUMBER(o)		((o)&0x1f)
115 
116 #define	IPOPT_CONTROL		0x00
117 #define	IPOPT_RESERVED1		0x20
118 #define	IPOPT_DEBMEAS		0x40
119 #define	IPOPT_RESERVED2		0x60
120 
121 #define	IPOPT_EOL		0		/* end of option list */
122 #define	IPOPT_NOP		1		/* no operation */
123 
124 #define	IPOPT_RR		7		/* record packet route */
125 #define	IPOPT_TS		68		/* timestamp */
126 #define	IPOPT_SECURITY		130		/* provide s,c,h,tcc */
127 #define	IPOPT_LSRR		131		/* loose source route */
128 #define	IPOPT_SATID		136		/* satnet id */
129 #define	IPOPT_SSRR		137		/* strict source route */
130 
131 /*
132  * Offsets to fields in options other than EOL and NOP.
133  */
134 #define	IPOPT_OPTVAL		0		/* option ID */
135 #define	IPOPT_OLEN		1		/* option length */
136 #define	IPOPT_OFFSET		2		/* offset within option */
137 #define	IPOPT_MINOFF		4		/* min value of above */
138 
139 /*
140  * Time stamp option structure.
141  */
142 struct	ip_timestamp {
143 	u_int8_t ipt_code;		/* IPOPT_TS */
144 	u_int8_t ipt_len;		/* size of structure (variable) */
145 	u_int8_t ipt_ptr;		/* index of current entry */
146 	u_int32_t ipt_flg:4,		/* flags, see below */
147 		  ipt_oflw:4;		/* overflow counter */
148 	union ipt_timestamp {
149 	n_time	ipt_time[1];
150 	struct	ipt_ta {
151 		struct in_addr ipt_addr;
152 		n_time ipt_time;
153 	} ipt_ta[1];
154 	} ipt_timestamp;
155 };
156 
157 /* flag bits for ipt_flg */
158 #define	IPOPT_TS_TSONLY		0		/* timestamps only */
159 #define	IPOPT_TS_TSANDADDR	1		/* timestamps and addresses */
160 #define	IPOPT_TS_PRESPEC	3		/* specified modules only */
161 
162 /* bits for security (not byte swapped) */
163 #define	IPOPT_SECUR_UNCLASS	0x0000
164 #define	IPOPT_SECUR_CONFID	0xf135
165 #define	IPOPT_SECUR_EFTO	0x789a
166 #define	IPOPT_SECUR_MMMM	0xbc4d
167 #define	IPOPT_SECUR_RESTR	0xaf13
168 #define	IPOPT_SECUR_SECRET	0xd788
169 #define	IPOPT_SECUR_TOPSECRET	0x6bc5
170 
171 /*
172  * Internet implementation parameters.
173  */
174 #define	MAXTTL		255		/* maximum time to live (seconds) */
175 #define	IPDEFTTL	64		/* default ttl, from RFC 1340 */
176 #define	IPFRAGTTL	60		/* time to live for frags, slowhz */
177 #define	IPTTLDEC	1		/* subtracted when forwarding */
178 
179 #define	IP_MSS		576		/* default maximum segment size */
180 
181 /*
182  * This is the real IPv4 pseudo header, used for computing the TCP and UDP
183  * checksums. For the Internet checksum, struct ipovly can be used instead.
184  * For stronger checksums, the real thing must be used.
185  */
186 struct ippseudo {
187 	struct    in_addr ippseudo_src;	/* source internet address */
188 	struct    in_addr ippseudo_dst;	/* destination internet address */
189 	u_int8_t  ippseudo_pad;		/* pad, must be zero */
190 	u_int8_t  ippseudo_p;		/* protocol */
191 	u_int16_t ippseudo_len;		/* protocol length */
192 };
193 
194 /* BIONIC addition: declarations matching the Linux kernel */
195 /*                  some programs expect these...          */
196 
197 #define IPOPT_OPTVAL 0
198 #define IPOPT_OLEN   1
199 #define IPOPT_OFFSET 2
200 #define IPOPT_MINOFF 4
201 #define MAX_IPOPTLEN 40
202 
203 #define IPOPT_COPY		0x80
204 #define IPOPT_CLASS_MASK	0x60
205 #define IPOPT_NUMBER_MASK	0x1f
206 
207 #define	IPOPT_CONTROL		0x00
208 #define	IPOPT_RESERVED1		0x20
209 #define	IPOPT_MEASUREMENT	0x40
210 #define	IPOPT_RESERVED2		0x60
211 
212 #define IPOPT_END	(0 |IPOPT_CONTROL)
213 #define IPOPT_NOOP	(1 |IPOPT_CONTROL)
214 #define IPOPT_SEC	(2 |IPOPT_CONTROL|IPOPT_COPY)
215 #define IPOPT_TIMESTAMP	(4 |IPOPT_MEASUREMENT)
216 #define IPOPT_SID	(8 |IPOPT_CONTROL|IPOPT_COPY)
217 #define IPOPT_RA	(20|IPOPT_CONTROL|IPOPT_COPY)
218 
219 struct iphdr {
220 #if defined(__LITTLE_ENDIAN_BITFIELD)
221 	uint8_t  ihl    :4,
222 		 version:4;
223 #elif defined (__BIG_ENDIAN_BITFIELD)
224 	uint8_t  version:4,
225   		 ihl    :4;
226 #else
227 #error	"Please fix <asm/byteorder.h>"
228 #endif
229 	uint8_t	  tos;
230 	uint16_t  tot_len;
231 	uint16_t  id;
232 	uint16_t  frag_off;
233 	uint8_t   ttl;
234 	uint8_t   protocol;
235 	uint16_t  check;
236 	int32_t   saddr;
237 	int32_t   daddr;
238 };
239 
240 struct ip_auth_hdr {
241 	uint8_t  nexthdr;
242 	uint8_t  hdrlen;
243 	uint16_t reserved;
244 	uint32_t spi;
245 	uint32_t seq_no;
246 	uint8_t  auth_data[0];
247 };
248 
249 struct ip_esp_hdr {
250 	uint32_t spi;
251 	uint32_t seq_no;
252 	uint8_t  enc_data[0];
253 };
254 
255 struct ip_comp_hdr {
256 	uint8_t  nexthdr;
257 	uint8_t  flags;
258 	uint16_t cpi;
259 };
260 
261 __END_DECLS
262 
263 #endif /* _NETINET_IP_H_ */
264