1/* $NetBSD: if_arp.h,v 1.43 2021/02/19 14:51:59 christos Exp $ */
2
3/*
4 * Copyright (c) 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 * @(#)if_arp.h 8.1 (Berkeley) 6/10/93
32 */
33
34#ifndef _NET_IF_ARP_H_
35#define _NET_IF_ARP_H_
36/*
37 * Address Resolution Protocol.
38 *
39 * See RFC 826 for protocol description. ARP packets are variable
40 * in size; the arphdr structure defines the fixed-length portion.
41 * Protocol type values are the same as those for 10 Mb/s Ethernet.
42 * It is followed by the variable-sized fields ar_sha, arp_spa,
43 * arp_tha and arp_tpa in that order, according to the lengths
44 * specified. Field names used correspond to RFC 826.
45 */
46struct arphdr {
47 uint16_t ar_hrd; /* format of hardware address */
48#define ARPHRD_ETHER 1 /* ethernet hardware format */
49#define ARPHRD_IEEE802 6 /* IEEE 802 hardware format */
50#define ARPHRD_ARCNET 7 /* ethernet hardware format */
51#define ARPHRD_FRELAY 15 /* frame relay hardware format */
52#define ARPHRD_STRIP 23 /* Ricochet Starmode Radio hardware format */
53#define ARPHRD_IEEE1394 24 /* IEEE 1394 (FireWire) hardware format */
54 uint16_t ar_pro; /* format of protocol address */
55 uint8_t ar_hln; /* length of hardware address */
56 uint8_t ar_pln; /* length of protocol address */
57 uint16_t ar_op; /* one of: */
58#define ARPOP_REQUEST 1 /* request to resolve address */
59#define ARPOP_REPLY 2 /* response to previous request */
60#define ARPOP_REVREQUEST 3 /* request protocol address given hardware */
61#define ARPOP_REVREPLY 4 /* response giving protocol address */
62#define ARPOP_INVREQUEST 8 /* request to identify peer */
63#define ARPOP_INVREPLY 9 /* response identifying peer */
64/*
65 * The remaining fields are variable in size,
66 * according to the sizes above.
67 */
68#ifdef COMMENT_ONLY
69 uint8_t ar_sha[]; /* sender hardware address */
70 uint8_t ar_spa[]; /* sender protocol address */
71 uint8_t ar_tha[]; /* target hardware address (!IEEE1394) */
72 uint8_t ar_tpa[]; /* target protocol address */
73#endif
74};
75
76static __inline uint8_t *
77ar_data(struct arphdr *ap)
78{
79 return (uint8_t *)(void *)(ap + 1);
80}
81
82static __inline uint8_t *
83ar_sha(struct arphdr *ap)
84{
85 return ar_data(ap) + 0;
86}
87
88static __inline uint8_t *
89ar_spa(struct arphdr *ap)
90{
91 return ar_data(ap) + ap->ar_hln;
92}
93
94static __inline uint8_t *
95ar_tha(struct arphdr *ap)
96{
97 if (ntohs(ap->ar_hrd) == ARPHRD_IEEE1394) {
98 return NULL;
99 } else {
100 return ar_data(ap) + ap->ar_hln + ap->ar_pln;
101 }
102}
103
104static __inline uint8_t *
105ar_tpa(struct arphdr *ap)
106{
107 if (ntohs(ap->ar_hrd) == ARPHRD_IEEE1394) {
108 return ar_data(ap) + ap->ar_hln + ap->ar_pln;
109 } else {
110 return ar_data(ap) + ap->ar_hln + ap->ar_pln + ap->ar_hln;
111 }
112}
113
114/*
115 * ARP ioctl request
116 */
117struct arpreq {
118 struct sockaddr arp_pa; /* protocol address */
119 struct sockaddr arp_ha; /* hardware address */
120 int arp_flags; /* flags */
121};
122/* arp_flags and at_flags field values */
123#define ATF_INUSE 0x01 /* entry in use */
124#define ATF_COM 0x02 /* completed entry (enaddr valid) */
125#define ATF_PERM 0x04 /* permanent entry */
126#define ATF_PUBL 0x08 /* publish entry (respond for other host) */
127#define ATF_USETRAILERS 0x10 /* has requested trailers */
128
129/*
130 * Kernel statistics about arp
131 */
132#define ARP_STAT_SNDTOTAL 0 /* total packets sent */
133#define ARP_STAT_SNDREPLY 1 /* replies sent */
134#define ARP_STAT_SENDREQUEST 2 /* requests sent */
135#define ARP_STAT_RCVTOTAL 3 /* total packets received */
136#define ARP_STAT_RCVREQUEST 4 /* valid requests received */
137#define ARP_STAT_RCVREPLY 5 /* replies received */
138#define ARP_STAT_RCVMCAST 6 /* multicast/broadcast received */
139#define ARP_STAT_RCVBADPROTO 7 /* unknown protocol type received */
140#define ARP_STAT_RCVBADLEN 8 /* bad (short) length received */
141#define ARP_STAT_RCVZEROTPA 9 /* received w/ null target ip */
142#define ARP_STAT_RCVZEROSPA 10 /* received w/ null source ip */
143#define ARP_STAT_RCVNOINT 11 /* couldn't map to interface */
144#define ARP_STAT_RCVLOCALSHA 12 /* received from local hw address */
145#define ARP_STAT_RCVBCASTSHA 13 /* received w/ broadcast src */
146#define ARP_STAT_RCVLOCALSPA 14 /* received for a local ip [dup!] */
147#define ARP_STAT_RCVOVERPERM 15 /* attempts to overwrite static info */
148#define ARP_STAT_RCVOVERINT 16 /* attempts to overwrite wrong if */
149#define ARP_STAT_RCVOVER 17 /* entries overwritten! */
150#define ARP_STAT_RCVLENCHG 18 /* changes in hw address len */
151#define ARP_STAT_DFRTOTAL 19 /* deferred pending ARP resolution */
152#define ARP_STAT_DFRSENT 20 /* deferred, then sent */
153#define ARP_STAT_DFRDROPPED 21 /* deferred, then dropped */
154#define ARP_STAT_ALLOCFAIL 22 /* failures to allocate llinfo */
155
156#define ARP_NSTATS 23
157
158void arp_stat_add(int, uint64_t);
159
160#endif /* !_NET_IF_ARP_H_ */