if_arp.h

/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1986, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef _NET_IF_ARP_H_
#define	_NET_IF_ARP_H_

/*
 * Address Resolution Protocol.
 *
 * See RFC 826 for protocol description.  ARP packets are variable
 * in size; the arphdr structure defines the fixed-length portion.
 * Protocol type values are the same as those for 10 Mb/s Ethernet.
 * It is followed by the variable-sized fields ar_sha, arp_spa,
 * arp_tha and arp_tpa in that order, according to the lengths
 * specified.  Field names used correspond to RFC 826.
 */
struct	arphdr {
	u_short	ar_hrd;		/* format of hardware address */
#define ARPHRD_ETHER 	1	/* ethernet hardware format */
#define ARPHRD_IEEE802	6	/* 802.2 networks (ethernet/tb/tr) */
#define ARPHRD_FRELAY 	15	/* frame relay hardware format */
#define ARPHRD_IEEE1394	24	/* firewire hardware format */
#define ARPHRD_INFINIBAND 32	/* infiniband hardware format */
	u_short	ar_pro;		/* format of protocol address */
	u_char	ar_hln;		/* length of hardware address */
	u_char	ar_pln;		/* length of protocol address */
	u_short	ar_op;		/* one of: */
#define	ARPOP_REQUEST	1	/* request to resolve address */
#define	ARPOP_REPLY	2	/* response to previous request */
#define	ARPOP_REVREQUEST 3	/* request protocol address given hardware */
#define	ARPOP_REVREPLY	4	/* response giving protocol address */
#define ARPOP_INVREQUEST 8 	/* request to identify peer */
#define ARPOP_INVREPLY	9	/* response identifying peer */
/*
 * The remaining fields are variable in size,
 * according to the sizes above.
 */
#ifdef COMMENT_ONLY
	u_char	ar_sha[];	/* sender hardware address */
	u_char	ar_spa[];	/* sender protocol address */
	u_char	ar_tha[];	/* target hardware address */
	u_char	ar_tpa[];	/* target protocol address */
#endif
};

#define ar_sha(ap)	(((caddr_t)((ap)+1)) +   0)
#define ar_spa(ap)	(((caddr_t)((ap)+1)) +   (ap)->ar_hln)
#define ar_tha(ap)	(((caddr_t)((ap)+1)) +   (ap)->ar_hln + (ap)->ar_pln)
#define ar_tpa(ap)	(((caddr_t)((ap)+1)) + 2*(ap)->ar_hln + (ap)->ar_pln)

#define arphdr_len2(ar_hln, ar_pln)					\
	(sizeof(struct arphdr) + 2*(ar_hln) + 2*(ar_pln))
#define arphdr_len(ap)	(arphdr_len2((ap)->ar_hln, (ap)->ar_pln))

/*
 * ARP ioctl request
 */
struct arpreq {
	struct	sockaddr arp_pa;		/* protocol address */
	struct	sockaddr arp_ha;		/* hardware address */
	int	arp_flags;			/* flags */
};
/*  arp_flags and at_flags field values */
#define	ATF_INUSE	0x01	/* entry in use */
#define ATF_COM		0x02	/* completed entry (enaddr valid) */
#define	ATF_PERM	0x04	/* permanent entry */
#define	ATF_PUBL	0x08	/* publish entry (respond for other host) */
#define	ATF_USETRAILERS	0x10	/* has requested trailers */

struct arpstat {
	/* Normal things that happen: */
	uint64_t txrequests;	/* # of ARP requests sent by this host. */
	uint64_t txreplies;	/* # of ARP replies sent by this host. */
	uint64_t rxrequests;	/* # of ARP requests received by this host. */
	uint64_t rxreplies;	/* # of ARP replies received by this host. */
	uint64_t received;	/* # of ARP packets received by this host. */
	uint64_t txerrors;	/* # of ARP requests failed to send. */

	uint64_t arp_spares[3];	/* For either the upper or lower half. */
	/* Abnormal event and error  counting: */
	uint64_t dropped;	/* # of packets dropped waiting for a reply. */
	uint64_t timeouts;	/* # of times with entries removed */
				/* due to timeout. */
	uint64_t dupips;	/* # of duplicate IPs detected. */
};

#ifdef _KERNEL
#include <sys/counter.h>
#include <net/vnet.h>

VNET_PCPUSTAT_DECLARE(struct arpstat, arpstat);
/*
 * In-kernel consumers can use these accessor macros directly to update
 * stats.
 */
#define	ARPSTAT_ADD(name, val)	\
    VNET_PCPUSTAT_ADD(struct arpstat, arpstat, name, (val))
#define	ARPSTAT_SUB(name, val)	ARPSTAT_ADD(name, -(val))
#define	ARPSTAT_INC(name)	ARPSTAT_ADD(name, 1)
#define	ARPSTAT_DEC(name)	ARPSTAT_SUB(name, 1)

#endif /* _KERNEL */

#endif /* !_NET_IF_ARP_H_ */