xref: /freebsd/sys/net/if_arp.h (revision 5e53a4f90f82c4345f277dd87cc9292f26e04a29)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
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  * $FreeBSD$
33  */
34 
35 #ifndef _NET_IF_ARP_H_
36 #define	_NET_IF_ARP_H_
37 
38 /*
39  * Address Resolution Protocol.
40  *
41  * See RFC 826 for protocol description.  ARP packets are variable
42  * in size; the arphdr structure defines the fixed-length portion.
43  * Protocol type values are the same as those for 10 Mb/s Ethernet.
44  * It is followed by the variable-sized fields ar_sha, arp_spa,
45  * arp_tha and arp_tpa in that order, according to the lengths
46  * specified.  Field names used correspond to RFC 826.
47  */
48 struct	arphdr {
49 	u_short	ar_hrd;		/* format of hardware address */
50 #define ARPHRD_ETHER 	1	/* ethernet hardware format */
51 #define ARPHRD_IEEE802	6	/* token-ring hardware format */
52 #define ARPHRD_ARCNET	7	/* arcnet hardware format */
53 #define ARPHRD_FRELAY 	15	/* frame relay hardware format */
54 #define ARPHRD_IEEE1394	24	/* firewire hardware format */
55 #define ARPHRD_INFINIBAND 32	/* infiniband hardware format */
56 	u_short	ar_pro;		/* format of protocol address */
57 	u_char	ar_hln;		/* length of hardware address */
58 	u_char	ar_pln;		/* length of protocol address */
59 	u_short	ar_op;		/* one of: */
60 #define	ARPOP_REQUEST	1	/* request to resolve address */
61 #define	ARPOP_REPLY	2	/* response to previous request */
62 #define	ARPOP_REVREQUEST 3	/* request protocol address given hardware */
63 #define	ARPOP_REVREPLY	4	/* response giving protocol address */
64 #define ARPOP_INVREQUEST 8 	/* request to identify peer */
65 #define ARPOP_INVREPLY	9	/* response identifying peer */
66 /*
67  * The remaining fields are variable in size,
68  * according to the sizes above.
69  */
70 #ifdef COMMENT_ONLY
71 	u_char	ar_sha[];	/* sender hardware address */
72 	u_char	ar_spa[];	/* sender protocol address */
73 	u_char	ar_tha[];	/* target hardware address */
74 	u_char	ar_tpa[];	/* target protocol address */
75 #endif
76 };
77 
78 #define ar_sha(ap)	(((caddr_t)((ap)+1)) +   0)
79 #define ar_spa(ap)	(((caddr_t)((ap)+1)) +   (ap)->ar_hln)
80 #define ar_tha(ap)	(((caddr_t)((ap)+1)) +   (ap)->ar_hln + (ap)->ar_pln)
81 #define ar_tpa(ap)	(((caddr_t)((ap)+1)) + 2*(ap)->ar_hln + (ap)->ar_pln)
82 
83 #define arphdr_len2(ar_hln, ar_pln)					\
84 	(sizeof(struct arphdr) + 2*(ar_hln) + 2*(ar_pln))
85 #define arphdr_len(ap)	(arphdr_len2((ap)->ar_hln, (ap)->ar_pln))
86 
87 /*
88  * ARP ioctl request
89  */
90 struct arpreq {
91 	struct	sockaddr arp_pa;		/* protocol address */
92 	struct	sockaddr arp_ha;		/* hardware address */
93 	int	arp_flags;			/* flags */
94 };
95 /*  arp_flags and at_flags field values */
96 #define	ATF_INUSE	0x01	/* entry in use */
97 #define ATF_COM		0x02	/* completed entry (enaddr valid) */
98 #define	ATF_PERM	0x04	/* permanent entry */
99 #define	ATF_PUBL	0x08	/* publish entry (respond for other host) */
100 #define	ATF_USETRAILERS	0x10	/* has requested trailers */
101 
102 struct arpstat {
103 	/* Normal things that happen: */
104 	uint64_t txrequests;	/* # of ARP requests sent by this host. */
105 	uint64_t txreplies;	/* # of ARP replies sent by this host. */
106 	uint64_t rxrequests;	/* # of ARP requests received by this host. */
107 	uint64_t rxreplies;	/* # of ARP replies received by this host. */
108 	uint64_t received;	/* # of ARP packets received by this host. */
109 
110 	uint64_t arp_spares[4];	/* For either the upper or lower half. */
111 	/* Abnormal event and error  counting: */
112 	uint64_t dropped;	/* # of packets dropped waiting for a reply. */
113 	uint64_t timeouts;	/* # of times with entries removed */
114 				/* due to timeout. */
115 	uint64_t dupips;	/* # of duplicate IPs detected. */
116 };
117 
118 #ifdef _KERNEL
119 #include <sys/counter.h>
120 #include <net/vnet.h>
121 
122 VNET_PCPUSTAT_DECLARE(struct arpstat, arpstat);
123 /*
124  * In-kernel consumers can use these accessor macros directly to update
125  * stats.
126  */
127 #define	ARPSTAT_ADD(name, val)	\
128     VNET_PCPUSTAT_ADD(struct arpstat, arpstat, name, (val))
129 #define	ARPSTAT_SUB(name, val)	ARPSTAT_ADD(name, -(val))
130 #define	ARPSTAT_INC(name)	ARPSTAT_ADD(name, 1)
131 #define	ARPSTAT_DEC(name)	ARPSTAT_SUB(name, 1)
132 
133 #endif /* _KERNEL */
134 
135 #endif /* !_NET_IF_ARP_H_ */
136