1 /* Definitions for Address Resolution Protocol.
2 Copyright (C) 1997-2023 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19 /* Based on the 4.4BSD and Linux version of this file. */
20
21 #ifndef _NET_IF_ARP_H
22
23 #define _NET_IF_ARP_H 1
24 #include <sys/cdefs.h>
25
26 #include <sys/types.h>
27 #include <sys/socket.h>
28 #include <stdint.h>
29
30 __BEGIN_DECLS
31
32 /* Some internals from deep down in the kernel. */
33 #define MAX_ADDR_LEN 7
34
35
36 /* This structure defines an ethernet arp header. */
37
38 /* ARP protocol opcodes. */
39 #define ARPOP_REQUEST 1 /* ARP request. */
40 #define ARPOP_REPLY 2 /* ARP reply. */
41 #define ARPOP_RREQUEST 3 /* RARP request. */
42 #define ARPOP_RREPLY 4 /* RARP reply. */
43
44 /* See RFC 826 for protocol description. ARP packets are variable
45 in size; the arphdr structure defines the fixed-length portion.
46 Protocol type values are the same as those for 10 Mb/s Ethernet.
47 It is followed by the variable-sized fields ar_sha, arp_spa,
48 arp_tha and arp_tpa in that order, according to the lengths
49 specified. Field names used correspond to RFC 826. */
50
51 struct arphdr
52 {
53 unsigned short int ar_hrd; /* Format of hardware address. */
54 unsigned short int ar_pro; /* Format of protocol address. */
55 unsigned char ar_hln; /* Length of hardware address. */
56 unsigned char ar_pln; /* Length of protocol address. */
57 unsigned short int ar_op; /* ARP opcode (command). */
58 #if 0
59 /* Ethernet looks like this : This bit is variable sized
60 however... */
61 unsigned char __ar_sha[ETH_ALEN]; /* Sender hardware address. */
62 unsigned char __ar_sip[4]; /* Sender IP address. */
63 unsigned char __ar_tha[ETH_ALEN]; /* Target hardware address. */
64 unsigned char __ar_tip[4]; /* Target IP address. */
65 #endif
66 };
67
68
69 /* ARP protocol HARDWARE identifiers. */
70 #define ARPHRD_NETROM 0 /* From KA9Q: NET/ROM pseudo. */
71 #define ARPHRD_ETHER 1 /* Ethernet 10Mbps. */
72 #define ARPHRD_EETHER 2 /* Experimental Ethernet. */
73 #define ARPHRD_AX25 3 /* AX.25 Level 2. */
74 #define ARPHRD_PRONET 4 /* PROnet token ring. */
75 #define ARPHRD_CHAOS 5 /* Chaosnet. */
76 #define ARPHRD_IEEE802 6 /* IEEE 802.2 Ethernet/TR/TB. */
77 #define ARPHRD_ARCNET 7 /* ARCnet. */
78 #define ARPHRD_APPLETLK 8 /* APPLEtalk. */
79 #define ARPHRD_DLCI 15 /* Frame Relay DLCI. */
80 #define ARPHRD_METRICOM 23 /* Metricom STRIP (new IANA id). */
81
82 /* Dummy types for non ARP hardware */
83 #define ARPHRD_SLIP 256
84 #define ARPHRD_CSLIP 257
85 #define ARPHRD_SLIP6 258
86 #define ARPHRD_CSLIP6 259
87 #define ARPHRD_RSRVD 260 /* Notional KISS type. */
88 #define ARPHRD_ADAPT 264
89 #define ARPHRD_ROSE 270
90 #define ARPHRD_X25 271 /* CCITT X.25. */
91 #define ARPHRD_PPP 512
92 #define ARPHRD_HDLC 513 /* (Cisco) HDLC. */
93 #define ARPHRD_LAPB 516 /* LAPB. */
94
95 #define ARPHRD_TUNNEL 768 /* IPIP tunnel. */
96 #define ARPHRD_TUNNEL6 769 /* IPIP6 tunnel. */
97 #define ARPHRD_FRAD 770 /* Frame Relay Access Device. */
98 #define ARPHRD_SKIP 771 /* SKIP vif. */
99 #define ARPHRD_LOOPBACK 772 /* Loopback device. */
100 #define ARPHRD_LOCALTLK 773 /* Localtalk device. */
101 #define ARPHRD_FDDI 774 /* Fiber Distributed Data Interface. */
102 #define ARPHRD_BIF 775 /* AP1000 BIF. */
103 #define ARPHRD_SIT 776 /* sit0 device - IPv6-in-IPv4. */
104
105
106 /* ARP ioctl request. */
107 struct arpreq
108 {
109 struct sockaddr arp_pa; /* Protocol address. */
110 struct sockaddr arp_ha; /* Hardware address. */
111 int arp_flags; /* Flags. */
112 struct sockaddr arp_netmask; /* Netmask (only for proxy arps). */
113 char arp_dev[16];
114 };
115
116 /* ARP Flag values. */
117 #define ATF_COM 0x02 /* Completed entry (ha valid). */
118 #define ATF_PERM 0x04 /* Permanent entry. */
119 #define ATF_PUBL 0x08 /* Publish entry. */
120 #define ATF_USETRAILERS 0x10 /* Has requested trailers. */
121 #define ATF_NETMASK 0x20 /* Want to use a netmask (only
122 for proxy entries). */
123 #define ATF_DONTPUB 0x40 /* Don't answer this addresses. */
124 #define ATF_MAGIC 0x80 /* Automatically added entry. */
125
126
127 /* Support for the user space arp daemon, arpd. */
128 #define ARPD_UPDATE 0x01
129 #define ARPD_LOOKUP 0x02
130 #define ARPD_FLUSH 0x03
131
132 struct arpd_request
133 {
134 unsigned short int req; /* Request type. */
135 uint32_t ip; /* IP address of entry. */
136 unsigned long int dev; /* Device entry is tied to. */
137 unsigned long int stamp;
138 unsigned long int updated;
139 unsigned char ha[MAX_ADDR_LEN]; /* Hardware address. */
140 };
141
142 __END_DECLS
143
144 #endif /* net/if_arp.h */