ISC DHCP  4.3.6
A reference DHCPv4 and DHCPv6 implementation
ip.h
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1 /* $NetBSD: ip.h,v 1.9 1995/05/15 01:22:44 cgd 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 8.1 (Berkeley) 6/10/93
32  */
33 
34 /*
35  * Definitions for internet protocol version 4.
36  * Per RFC 791, September 1981.
37  */
38 #define IPVERSION 4
39 
40 /*
41  * Structure of an internet header, naked of options.
42  *
43  * We declare ip_len and ip_off to be short, rather than u_short
44  * pragmatically since otherwise unsigned comparisons can result
45  * against negative integers quite easily, and fail in subtle ways.
46  */
47 struct ip {
48  u_int8_t ip_fvhl; /* header length, version */
49  u_int8_t ip_tos; /* type of service */
50  int16_t ip_len; /* total length */
51  u_int16_t ip_id; /* identification */
52  int16_t ip_off; /* fragment offset field */
53 #define IP_DF 0x4000 /* dont fragment flag */
54 #define IP_MF 0x2000 /* more fragments flag */
55 #define IP_OFFMASK 0x1fff /* mask for fragmenting bits */
56  u_int8_t ip_ttl; /* time to live */
57  u_int8_t ip_p; /* protocol */
58  u_int16_t ip_sum; /* checksum */
59  struct in_addr ip_src, ip_dst; /* source and dest address */
60 };
61 
62 #define IP_V(iph) ((iph)->ip_fvhl >> 4)
63 #define IP_HL(iph) (((iph)->ip_fvhl & 0x0F) << 2)
64 #define IP_V_SET(iph,x) ((iph)->ip_fvhl = ((iph)->ip_fvhl & 0x0F) | ((x) << 4))
65 #define IP_HL_SET(iph,x) ((iph)->ip_fvhl = \
66  ((iph)->ip_fvhl & 0xF0) | (((x) >> 2) & 0x0F))
67 
68 #define IP_MAXPACKET 65535 /* maximum packet size */
69 
70 /*
71  * Definitions for IP type of service (ip_tos)
72  */
73 #define IPTOS_LOWDELAY 0x10
74 #define IPTOS_THROUGHPUT 0x08
75 #define IPTOS_RELIABILITY 0x04
76 /* IPTOS_LOWCOST 0x02 XXX */
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_SECURITY 130 /* provide s,c,h,tcc */
108 #define IPOPT_LSRR 131 /* loose source route */
109 #define IPOPT_SATID 136 /* satnet id */
110 #define IPOPT_SSRR 137 /* strict source route */
111 
112 /*
113  * Offsets to fields in options other than EOL and NOP.
114  */
115 #define IPOPT_OPTVAL 0 /* option ID */
116 #define IPOPT_OLEN 1 /* option length */
117 #define IPOPT_OFFSET 2 /* offset within option */
118 #define IPOPT_MINOFF 4 /* min value of above */
119 
120 /*
121  * Time stamp option structure.
122  */
123 struct ip_timestamp {
124  u_int8_t ipt_code; /* IPOPT_TS */
125  u_int8_t ipt_len; /* size of structure (variable) */
126  u_int8_t ipt_ptr; /* index of current entry */
127  u_int8_t ipt_flg_oflw; /* flags, see below, overflow counter */
129  u_int32_t ipt_time[1];
130  struct ipt_ta {
131  struct in_addr ipt_addr;
132  u_int32_t ipt_time;
133  } ipt_ta[1];
134  } ipt_timestamp;
135 };
136 
137 /* flag bits for ipt_flg */
138 #define IPOPT_TS_TSONLY 0 /* timestamps only */
139 #define IPOPT_TS_TSANDADDR 1 /* timestamps and addresses */
140 #define IPOPT_TS_PRESPEC 3 /* specified modules only */
141 
142 /* bits for security (not byte swapped) */
143 #define IPOPT_SECUR_UNCLASS 0x0000
144 #define IPOPT_SECUR_CONFID 0xf135
145 #define IPOPT_SECUR_EFTO 0x789a
146 #define IPOPT_SECUR_MMMM 0xbc4d
147 #define IPOPT_SECUR_RESTR 0xaf13
148 #define IPOPT_SECUR_SECRET 0xd788
149 #define IPOPT_SECUR_TOPSECRET 0x6bc5
150 
151 /*
152  * Internet implementation parameters.
153  */
154 #define MAXTTL 255 /* maximum time to live (seconds) */
155 #define IPDEFTTL 64 /* default ttl, from RFC 1340 */
156 #define IPFRAGTTL 60 /* time to live for frags, slowhz */
157 #define IPTTLDEC 1 /* subtracted when forwarding */
158 
159 #define IP_MSS 576 /* default maximum segment size */
u_int8_t ipt_code
Definition: ip.h:124
struct in_addr ip_src ip_dst
Definition: ip.h:59
u_int8_t ip_ttl
Definition: ip.h:56
u_int8_t ip_tos
Definition: ip.h:49
int16_t ip_off
Definition: ip.h:52
u_int8_t ipt_ptr
Definition: ip.h:126
Definition: ip.h:47
int16_t ip_len
Definition: ip.h:50
u_int8_t ipt_flg_oflw
Definition: ip.h:127
u_int16_t ip_sum
Definition: ip.h:58
u_int8_t ip_fvhl
Definition: ip.h:48
u_int16_t ip_id
Definition: ip.h:51
u_int8_t ip_p
Definition: ip.h:57
u_int8_t ipt_len
Definition: ip.h:125