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 boolean_t arp_is_entry_probing(route_t p_route);
65extern errno_t arp_lookup_ip(ifnet_t interface,
66 const struct sockaddr_in *ip_dest, struct sockaddr_dl *ll_dest,
67 size_t ll_dest_len, route_t hint, mbuf_t packet);
68#define inet_arp_lookup arp_lookup_ip
69#else
70extern errno_t inet_arp_lookup(ifnet_t interface,
71 const struct sockaddr_in *ip_dest, struct sockaddr_dl *ll_dest,
72 size_t ll_dest_len, route_t hint, mbuf_t packet);
73#endif /* !BSD_KERNEL_PRIVATE */
74
75/*!
76 * @function inet_arp_handle_input
77 * @discussion This function should be called by code that handles
78 * inbound arp packets. The caller should parse the ARP packet to
79 * pull out the operation and the relevant addresses. If a response
80 * is required, the proto_media_send_arp function will be called.
81 *
82 * This function will lookup the sender in the routing table and
83 * add an arp entry if necessary. Any queued packets waiting for
84 * the arp resolution will also be transmitted.
85 * @param interface The interface the packet was received on.
86 * @param arp_op The arp operation, ARPOP_REQUEST or ARPOP_REPLY
87 * @param sender_hw The sender hardware address from the arp payload.
88 * @param sender_ip The sender IP address from the arp payload.
89 * @param target_ip The target IP address from the arp payload.
90 * @result 0 on success or an errno error value on failure.
91 */
92#ifdef BSD_KERNEL_PRIVATE
93extern errno_t arp_ip_handle_input(ifnet_t ifp, u_int16_t arpop,
94 const struct sockaddr_dl *sender_hw, const struct sockaddr_in *sender_ip,
95 const struct sockaddr_in *target_ip);
96#define inet_arp_handle_input arp_ip_handle_input
97#else
98extern errno_t inet_arp_handle_input(ifnet_t ifp, u_int16_t arpop,
99 const struct sockaddr_dl *sender_hw, const struct sockaddr_in *sender_ip,
100 const struct sockaddr_in *target_ip);
101#endif /* !BSD_KERNEL_PRIVATE */
102
103/*!
104 * @function inet_arp_init_ifaddr
105 * @discussion This function should be called in two places, when an IP
106 * address is added and when the hardware address changes. This
107 * function will setup the ifaddr_t for use with the IP ARP
108 * functions. This function will also trigger the transmission of a
109 * gratuitous ARP packet.
110 *
111 * When the SIOCSIFADDR ioctl is handled, the data parameter will
112 * be an ifaddr_t. If this is an IP address, inet_arp_init_ifaddr
113 * should be called. This is usually performed in the protocol
114 * attachment's ioctl handler.
115 *
116 * When the event handler for the protocol attachment receives a
117 * KEV_DL_LINK_ADDRESS_CHANGED event, the event handler should call
118 * inet_arp_init_ifaddr for each interface ip address.
119 *
120 * For an example, see bsd/net/ether_inet_pr_module.c in xnu.
121 * Search for inet_arp_init_ifaddr.
122 * @param interface The interface the packet was received on.
123 * @param ipaddr The ip interface address.
124 */
125#ifdef BSD_KERNEL_PRIVATE
126/* inet_arp_init_ifaddr is aliased to arp_ifinit (if_ether.h) */
127#define inet_arp_init_ifaddr arp_ifinit
128#else
129extern void inet_arp_init_ifaddr(ifnet_t interface, ifaddr_t ipaddr);
130#endif /* !BSD_KERNEL_PRIVATE */
131
132#ifdef BSD_KERNEL_PRIVATE
133extern void arp_init(void);
134extern void in_arpdrain(void *);
135extern void arp_llreach_set_reachable(struct ifnet *, void *, unsigned int);
136#endif /* BSD_KERNEL_PRIVATE */
137#endif /* KERNEL */
138#endif /* _NETINET_IN_ARP_H_ */
139