1/*
2 * Copyright (c) 2009-2013 Apple Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
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27 */
28
29#ifndef _NETINET_IN_ARP_H_
30#define	_NETINET_IN_ARP_H_
31#ifdef KERNEL
32#include <sys/kernel_types.h>
33
34struct sockaddr;
35struct sockaddr_dl;
36struct sockaddr_in;
37
38/*!
39 *	@function inet_arp_lookup
40 *	@discussion This function will check the routing table for a cached
41 *		arp entry or trigger an arp query to resolve the ip address to a
42 *		link-layer address.
43 *
44 *		Arp entries are stored in the routing table. This function will
45 *		lookup the ip destination in the routing table. If the
46 *		destination requires forwarding to a gateway, the route of the
47 *		gateway will be looked up. The route entry is inspected to
48 *		determine if the link layer destination address is known. If
49 *		unknown, the arp generation function for IP attached to the
50 *		interface is called to create an arp request packet.
51 *	@param interface The interface the packet is being sent on.
52 *	@param ip_dest The ip destination of the packet.
53 *	@param ll_dest On output, the link-layer destination.
54 *	@param ll_dest_len The length of the buffer for ll_dest.
55 *	@param hint Any routing hint passed down from the protocol.
56 *	@param packet The packet being transmitted.
57 *	@result May return an error such as EHOSTDOWN or ENETUNREACH. If
58 *		this function returns EJUSTRETURN, the packet has been queued
59 *		and will be sent when an arp response is received. If any other
60 *		value is returned, the caller is responsible for disposing of
61 *		the packet.
62 */
63#ifdef BSD_KERNEL_PRIVATE
64extern errno_t arp_lookup_ip(ifnet_t interface,
65    const struct sockaddr_in *ip_dest, struct sockaddr_dl *ll_dest,
66    size_t ll_dest_len, route_t hint, mbuf_t packet);
67#define inet_arp_lookup arp_lookup_ip
68#else
69extern errno_t inet_arp_lookup(ifnet_t interface,
70    const struct sockaddr_in *ip_dest, struct sockaddr_dl *ll_dest,
71    size_t ll_dest_len, route_t hint, mbuf_t packet);
72#endif /* !BSD_KERNEL_PRIVATE */
73
74/*!
75 *	@function inet_arp_handle_input
76 *	@discussion This function should be called by code that handles
77 *		inbound arp packets. The caller should parse the ARP packet to
78 *		pull out the operation and the relevant addresses. If a response
79 *		is required, the proto_media_send_arp function will be called.
80 *
81 *		This function will lookup the sender in the routing table and
82 *		add an arp entry if necessary. Any queued packets waiting for
83 *		the arp resolution will also be transmitted.
84 *	@param interface The interface the packet was received on.
85 *	@param arp_op The arp operation, ARPOP_REQUEST or ARPOP_REPLY
86 *	@param sender_hw The sender hardware address from the arp payload.
87 *	@param sender_ip The sender IP address from the arp payload.
88 *	@param target_ip The target IP address from the arp payload.
89 *	@result 0 on success or an errno error value on failure.
90 */
91#ifdef BSD_KERNEL_PRIVATE
92extern errno_t arp_ip_handle_input(ifnet_t ifp, u_int16_t arpop,
93    const struct sockaddr_dl *sender_hw, const struct sockaddr_in *sender_ip,
94    const struct sockaddr_in *target_ip);
95#define inet_arp_handle_input arp_ip_handle_input
96#else
97extern errno_t inet_arp_handle_input(ifnet_t ifp, u_int16_t arpop,
98    const struct sockaddr_dl *sender_hw, const struct sockaddr_in *sender_ip,
99    const struct sockaddr_in *target_ip);
100#endif /* !BSD_KERNEL_PRIVATE */
101
102/*!
103 *	@function inet_arp_init_ifaddr
104 *	@discussion This function should be called in two places, when an IP
105 *		address is added and when the hardware address changes. This
106 *		function will setup the ifaddr_t for use with the IP ARP
107 *		functions. This function will also trigger the transmission of a
108 *		gratuitous ARP packet.
109 *
110 *		When the SIOCSIFADDR ioctl is handled, the data parameter will
111 *		be an ifaddr_t. If this is an IP address, inet_arp_init_ifaddr
112 *		should be called. This is usually performed in the protocol
113 *		attachment's ioctl handler.
114 *
115 *		When the event handler for the protocol attachment receives a
116 *		KEV_DL_LINK_ADDRESS_CHANGED event, the event handler should call
117 *		inet_arp_init_ifaddr for each interface ip address.
118 *
119 *		For an example, see bsd/net/ether_inet_pr_module.c in xnu.
120 *		Search for inet_arp_init_ifaddr.
121 *	@param interface The interface the packet was received on.
122 *	@param ipaddr The ip interface address.
123 */
124#ifdef BSD_KERNEL_PRIVATE
125/* inet_arp_init_ifaddr is aliased to arp_ifinit (if_ether.h) */
126#define	inet_arp_init_ifaddr	arp_ifinit
127#else
128extern void inet_arp_init_ifaddr(ifnet_t interface, ifaddr_t ipaddr);
129#endif /* !BSD_KERNEL_PRIVATE */
130
131#ifdef BSD_KERNEL_PRIVATE
132extern void arp_init(void);
133extern void in_arpdrain(void *);
134extern void arp_llreach_set_reachable(struct ifnet *, void *, unsigned int);
135#endif /* BSD_KERNEL_PRIVATE */
136#endif /* KERNEL */
137#endif /* _NETINET_IN_ARP_H_ */
138