xref: /freebsd/sys/net/if_arp.h (revision 2e3f49888ec8851bafb22011533217487764fdb0)
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 
32 #ifndef _NET_IF_ARP_H_
33 #define	_NET_IF_ARP_H_
34 
35 /*
36  * Address Resolution Protocol.
37  *
38  * See RFC 826 for protocol description.  ARP packets are variable
39  * in size; the arphdr structure defines the fixed-length portion.
40  * Protocol type values are the same as those for 10 Mb/s Ethernet.
41  * It is followed by the variable-sized fields ar_sha, arp_spa,
42  * arp_tha and arp_tpa in that order, according to the lengths
43  * specified.  Field names used correspond to RFC 826.
44  */
45 struct	arphdr {
46 	u_short	ar_hrd;		/* format of hardware address */
47 #define ARPHRD_ETHER 	1	/* ethernet hardware format */
48 #define ARPHRD_IEEE802	6	/* token-ring hardware format */
49 #define ARPHRD_FRELAY 	15	/* frame relay hardware format */
50 #define ARPHRD_IEEE1394	24	/* firewire hardware format */
51 #define ARPHRD_INFINIBAND 32	/* infiniband hardware format */
52 	u_short	ar_pro;		/* format of protocol address */
53 	u_char	ar_hln;		/* length of hardware address */
54 	u_char	ar_pln;		/* length of protocol address */
55 	u_short	ar_op;		/* one of: */
56 #define	ARPOP_REQUEST	1	/* request to resolve address */
57 #define	ARPOP_REPLY	2	/* response to previous request */
58 #define	ARPOP_REVREQUEST 3	/* request protocol address given hardware */
59 #define	ARPOP_REVREPLY	4	/* response giving protocol address */
60 #define ARPOP_INVREQUEST 8 	/* request to identify peer */
61 #define ARPOP_INVREPLY	9	/* response identifying peer */
62 /*
63  * The remaining fields are variable in size,
64  * according to the sizes above.
65  */
66 #ifdef COMMENT_ONLY
67 	u_char	ar_sha[];	/* sender hardware address */
68 	u_char	ar_spa[];	/* sender protocol address */
69 	u_char	ar_tha[];	/* target hardware address */
70 	u_char	ar_tpa[];	/* target protocol address */
71 #endif
72 };
73 
74 #define ar_sha(ap)	(((caddr_t)((ap)+1)) +   0)
75 #define ar_spa(ap)	(((caddr_t)((ap)+1)) +   (ap)->ar_hln)
76 #define ar_tha(ap)	(((caddr_t)((ap)+1)) +   (ap)->ar_hln + (ap)->ar_pln)
77 #define ar_tpa(ap)	(((caddr_t)((ap)+1)) + 2*(ap)->ar_hln + (ap)->ar_pln)
78 
79 #define arphdr_len2(ar_hln, ar_pln)					\
80 	(sizeof(struct arphdr) + 2*(ar_hln) + 2*(ar_pln))
81 #define arphdr_len(ap)	(arphdr_len2((ap)->ar_hln, (ap)->ar_pln))
82 
83 /*
84  * ARP ioctl request
85  */
86 struct arpreq {
87 	struct	sockaddr arp_pa;		/* protocol address */
88 	struct	sockaddr arp_ha;		/* hardware address */
89 	int	arp_flags;			/* flags */
90 };
91 /*  arp_flags and at_flags field values */
92 #define	ATF_INUSE	0x01	/* entry in use */
93 #define ATF_COM		0x02	/* completed entry (enaddr valid) */
94 #define	ATF_PERM	0x04	/* permanent entry */
95 #define	ATF_PUBL	0x08	/* publish entry (respond for other host) */
96 #define	ATF_USETRAILERS	0x10	/* has requested trailers */
97 
98 struct arpstat {
99 	/* Normal things that happen: */
100 	uint64_t txrequests;	/* # of ARP requests sent by this host. */
101 	uint64_t txreplies;	/* # of ARP replies sent by this host. */
102 	uint64_t rxrequests;	/* # of ARP requests received by this host. */
103 	uint64_t rxreplies;	/* # of ARP replies received by this host. */
104 	uint64_t received;	/* # of ARP packets received by this host. */
105 	uint64_t txerrors;	/* # of ARP requests failed to send. */
106 
107 	uint64_t arp_spares[3];	/* For either the upper or lower half. */
108 	/* Abnormal event and error  counting: */
109 	uint64_t dropped;	/* # of packets dropped waiting for a reply. */
110 	uint64_t timeouts;	/* # of times with entries removed */
111 				/* due to timeout. */
112 	uint64_t dupips;	/* # of duplicate IPs detected. */
113 };
114 
115 #ifdef _KERNEL
116 #include <sys/counter.h>
117 #include <net/vnet.h>
118 
119 VNET_PCPUSTAT_DECLARE(struct arpstat, arpstat);
120 /*
121  * In-kernel consumers can use these accessor macros directly to update
122  * stats.
123  */
124 #define	ARPSTAT_ADD(name, val)	\
125     VNET_PCPUSTAT_ADD(struct arpstat, arpstat, name, (val))
126 #define	ARPSTAT_SUB(name, val)	ARPSTAT_ADD(name, -(val))
127 #define	ARPSTAT_INC(name)	ARPSTAT_ADD(name, 1)
128 #define	ARPSTAT_DEC(name)	ARPSTAT_SUB(name, 1)
129 
130 #endif /* _KERNEL */
131 
132 #endif /* !_NET_IF_ARP_H_ */
133