xref: /freebsd/sys/net/if_arp.h (revision 2be1a816b9ff69588e55be0a84cbe2a31efc0f2f)
1 /*-
2  * Copyright (c) 1986, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 4. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  *	@(#)if_arp.h	8.1 (Berkeley) 6/10/93
30  * $FreeBSD$
31  */
32 
33 #ifndef _NET_IF_ARP_H_
34 #define	_NET_IF_ARP_H_
35 
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  */
46 struct	arphdr {
47 	u_short	ar_hrd;		/* format of hardware address */
48 #define ARPHRD_ETHER 	1	/* ethernet hardware format */
49 #define ARPHRD_IEEE802	6	/* token-ring hardware format */
50 #define ARPHRD_ARCNET	7	/* arcnet hardware format */
51 #define ARPHRD_FRELAY 	15	/* frame relay hardware format */
52 #define ARPHRD_IEEE1394	24	/* firewire hardware format */
53 	u_short	ar_pro;		/* format of protocol address */
54 	u_char	ar_hln;		/* length of hardware address */
55 	u_char	ar_pln;		/* length of protocol address */
56 	u_short	ar_op;		/* one of: */
57 #define	ARPOP_REQUEST	1	/* request to resolve address */
58 #define	ARPOP_REPLY	2	/* response to previous request */
59 #define	ARPOP_REVREQUEST 3	/* request protocol address given hardware */
60 #define	ARPOP_REVREPLY	4	/* response giving protocol address */
61 #define ARPOP_INVREQUEST 8 	/* request to identify peer */
62 #define ARPOP_INVREPLY	9	/* response identifying peer */
63 /*
64  * The remaining fields are variable in size,
65  * according to the sizes above.
66  */
67 #ifdef COMMENT_ONLY
68 	u_char	ar_sha[];	/* sender hardware address */
69 	u_char	ar_spa[];	/* sender protocol address */
70 	u_char	ar_tha[];	/* target hardware address */
71 	u_char	ar_tpa[];	/* target protocol address */
72 #endif
73 };
74 
75 #define ar_sha(ap)	(((caddr_t)((ap)+1)) +   0)
76 #define ar_spa(ap)	(((caddr_t)((ap)+1)) +   (ap)->ar_hln)
77 #define ar_tha(ap)	(((caddr_t)((ap)+1)) +   (ap)->ar_hln + (ap)->ar_pln)
78 #define ar_tpa(ap)	(((caddr_t)((ap)+1)) + 2*(ap)->ar_hln + (ap)->ar_pln)
79 
80 #define arphdr_len2(ar_hln, ar_pln)					\
81 	(sizeof(struct arphdr) + 2*(ar_hln) + 2*(ar_pln))
82 #define arphdr_len(ap)	(arphdr_len2((ap)->ar_hln, (ap)->ar_pln))
83 
84 /*
85  * ARP ioctl request
86  */
87 struct arpreq {
88 	struct	sockaddr arp_pa;		/* protocol address */
89 	struct	sockaddr arp_ha;		/* hardware address */
90 	int	arp_flags;			/* flags */
91 };
92 /*  arp_flags and at_flags field values */
93 #define	ATF_INUSE	0x01	/* entry in use */
94 #define ATF_COM		0x02	/* completed entry (enaddr valid) */
95 #define	ATF_PERM	0x04	/* permanent entry */
96 #define	ATF_PUBL	0x08	/* publish entry (respond for other host) */
97 #define	ATF_USETRAILERS	0x10	/* has requested trailers */
98 
99 #ifdef _KERNEL
100 /*
101  * Structure shared between the ethernet driver modules and
102  * the address resolution code.
103  */
104 struct	arpcom {
105 	struct 	ifnet *ac_ifp;		/* network-visible interface */
106 	void	*ac_netgraph;		/* ng_ether(4) netgraph node info */
107 };
108 #define IFP2AC(ifp) ((struct arpcom *)(ifp->if_l2com))
109 #define AC2IFP(ac) ((ac)->ac_ifp)
110 
111 #endif
112 
113 #endif /* !_NET_IF_ARP_H_ */
114