bsd/netinet/in_arp.h

   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
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
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  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
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  23  * Please see the License for the specific language governing rights and
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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
  34 struct sockaddr;
  35 struct sockaddr_dl;
  36 struct 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
  64 extern 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
  69 extern 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
  92 extern 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
  97 extern 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
 128 extern void inet_arp_init_ifaddr(ifnet_t interface, ifaddr_t ipaddr);
 129 #endif /* !BSD_KERNEL_PRIVATE */
 130
 131 #ifdef BSD_KERNEL_PRIVATE
 132 extern void arp_init(void);
 133 extern void in_arpdrain(void *);
 134 extern void arp_llreach_set_reachable(struct ifnet *, void *, unsigned int);
 135 #endif /* BSD_KERNEL_PRIVATE */
 136 #endif /* KERNEL */
 137 #endif /* _NETINET_IN_ARP_H_ */