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  */
35 
36 #ifndef netdissect_ip_h
37 #define netdissect_ip_h
38 
39 /*
40  * Definitions for internet protocol version 4.
41  * Per RFC 791, September 1981.
42  */
43 #define	IPVERSION	4
44 
45 /*
46  * Structure of an internet header, naked of options.
47  *
48  * We declare ip_len and ip_off to be short, rather than u_short
49  * pragmatically since otherwise unsigned comparisons can result
50  * against negative integers quite easily, and fail in subtle ways.
51  */
52 struct ip {
53 	nd_uint8_t	ip_vhl;		/* header length, version */
54 #define IP_V(ip)	(((ip)->ip_vhl & 0xf0) >> 4)
55 #define IP_HL(ip)	((ip)->ip_vhl & 0x0f)
56 	nd_uint8_t	ip_tos;		/* type of service */
57 	nd_uint16_t	ip_len;		/* total length */
58 	nd_uint16_t	ip_id;		/* identification */
59 	nd_uint16_t	ip_off;		/* fragment offset field */
60 #define	IP_DF 0x4000			/* dont fragment flag */
61 #define	IP_MF 0x2000			/* more fragments flag */
62 #define	IP_OFFMASK 0x1fff		/* mask for fragmenting bits */
63 	nd_uint8_t	ip_ttl;		/* time to live */
64 	nd_uint8_t	ip_p;		/* protocol */
65 	nd_uint16_t	ip_sum;		/* checksum */
66 	nd_ipv4		ip_src,ip_dst;	/* source and dest address */
67 };
68 
69 #define	IP_MAXPACKET	65535		/* maximum packet size */
70 
71 /*
72  * Definitions for IP type of service (ip_tos)
73  */
74 #define	IPTOS_LOWDELAY		0x10
75 #define	IPTOS_THROUGHPUT	0x08
76 #define	IPTOS_RELIABILITY	0x04
77 
78 /*
79  * Definitions for IP precedence (also in ip_tos) (hopefully unused)
80  */
81 #define	IPTOS_PREC_NETCONTROL		0xe0
82 #define	IPTOS_PREC_INTERNETCONTROL	0xc0
83 #define	IPTOS_PREC_CRITIC_ECP		0xa0
84 #define	IPTOS_PREC_FLASHOVERRIDE	0x80
85 #define	IPTOS_PREC_FLASH		0x60
86 #define	IPTOS_PREC_IMMEDIATE		0x40
87 #define	IPTOS_PREC_PRIORITY		0x20
88 #define	IPTOS_PREC_ROUTINE		0x00
89 
90 /*
91  * Definitions for options.
92  */
93 #define	IPOPT_COPIED(o)		((o)&0x80)
94 #define	IPOPT_CLASS(o)		((o)&0x60)
95 #define	IPOPT_NUMBER(o)		((o)&0x1f)
96 
97 #define	IPOPT_CONTROL		0x00
98 #define	IPOPT_RESERVED1		0x20
99 #define	IPOPT_DEBMEAS		0x40
100 #define	IPOPT_RESERVED2		0x60
101 
102 #define	IPOPT_EOL		0		/* end of option list */
103 #define	IPOPT_NOP		1		/* no operation */
104 
105 #define	IPOPT_RR		7		/* record packet route */
106 #define	IPOPT_TS		68		/* timestamp */
107 #define	IPOPT_RFC1393           82              /* traceroute RFC 1393 */
108 #define	IPOPT_SECURITY		130		/* provide s,c,h,tcc */
109 #define	IPOPT_LSRR		131		/* loose source route */
110 #define	IPOPT_SATID		136		/* satnet id */
111 #define	IPOPT_SSRR		137		/* strict source route */
112 #define IPOPT_RA                148             /* router-alert, rfc2113 */
113 
114 /*
115  * Offsets to fields in options other than EOL and NOP.
116  */
117 #define	IPOPT_OPTVAL		0		/* option ID */
118 #define	IPOPT_OLEN		1		/* option length */
119 #define IPOPT_OFFSET		2		/* offset within option */
120 #define	IPOPT_MINOFF		4		/* min value of above */
121 
122 /*
123  * Time stamp option structure.
124  */
125 struct	ip_timestamp {
126 	nd_uint8_t	ipt_code;	/* IPOPT_TS */
127 	nd_uint8_t	ipt_len;	/* size of structure (variable) */
128 	nd_uint8_t	ipt_ptr;	/* index of current entry */
129 	nd_uint8_t	ipt_oflwflg;	/* flags, overflow counter */
130 #define IPTS_OFLW(ip)	(((ipt)->ipt_oflwflg & 0xf0) >> 4)
131 #define IPTS_FLG(ip)	((ipt)->ipt_oflwflg & 0x0f)
132 	union ipt_timestamp {
133 		nd_uint32_t ipt_time[1];
134 		struct	ipt_ta {
135 			nd_ipv4 ipt_addr;
136 			nd_uint32_t ipt_time;
137 		} ipt_ta[1];
138 	} ipt_timestamp;
139 };
140 
141 /* flag bits for ipt_flg */
142 #define	IPOPT_TS_TSONLY		0		/* timestamps only */
143 #define	IPOPT_TS_TSANDADDR	1		/* timestamps and addresses */
144 #define	IPOPT_TS_PRESPEC	3		/* specified modules only */
145 
146 /* bits for security (not byte swapped) */
147 #define	IPOPT_SECUR_UNCLASS	0x0000
148 #define	IPOPT_SECUR_CONFID	0xf135
149 #define	IPOPT_SECUR_EFTO	0x789a
150 #define	IPOPT_SECUR_MMMM	0xbc4d
151 #define	IPOPT_SECUR_RESTR	0xaf13
152 #define	IPOPT_SECUR_SECRET	0xd788
153 #define	IPOPT_SECUR_TOPSECRET	0x6bc5
154 
155 /*
156  * Internet implementation parameters.
157  */
158 #define	MAXTTL		255		/* maximum time to live (seconds) */
159 #define	IPDEFTTL	64		/* default ttl, from RFC 1340 */
160 #define	IPFRAGTTL	60		/* time to live for frags, slowhz */
161 #define	IPTTLDEC	1		/* subtracted when forwarding */
162 
163 #define	IP_MSS		576		/* default maximum segment size */
164 #endif /* netdissect_ip_h */
165