bsd/netinet/in_arp.h

   1 /*
   2  * Copyright (c) 2004 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_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. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23
  24 #ifndef _NETINET_IN_ARP_H_
  25 #define _NETINET_IN_ARP_H_
  26 #include <sys/kernel_types.h>
  27
  28 struct sockaddr_dl;
  29 struct sockaddr_in;
  30
  31 /*!
  32         @function inet_arp_lookup
  33         @discussion This function will check the routing table for a cached
  34                 arp entry or trigger an arp query to resolve the ip address to a
  35                 link-layer address.
  36
  37                 Arp entries are stored in the routing table. This function will
  38                 lookup the ip destination in the routing table. If the
  39                 destination requires forwarding to a gateway, the route of the
  40                 gateway will be looked up. The route entry is inspected to
  41                 determine if the link layer destination address is known. If
  42                 unknown, the arp generation function for IP attached to the
  43                 interface is called to create an arp request packet.
  44         @param interface The interface the packet is being sent on.
  45         @param ip_dest The ip destination of the packet.
  46         @param ll_dest On output, the link-layer destination.
  47         @param ll_dest_len The length of the buffer for ll_dest.
  48         @param hint Any routing hint passed down from the protocol.
  49         @param packet The packet being transmitted.
  50         @result May return an error such as EHOSTDOWN or ENETUNREACH. If
  51                 this function returns EJUSTRETURN, the packet has been queued
  52                 and will be sent when an arp response is received. If any other
  53                 value is returned, the caller is responsible for disposing of
  54                 the packet.
  55  */
  56 #ifdef BSD_KERNEL_PRIVATE
  57 #define inet_arp_lookup arp_lookup_ip
  58 #else
  59 errno_t inet_arp_lookup(ifnet_t interface, const struct sockaddr_in *ip_dest,
  60                         struct sockaddr_dl *ll_dest, size_t ll_dest_len, route_t hint,
  61                         mbuf_t packet);
  62 #endif /* BSD_KERNEL_PRIVATE */
  63 #ifdef KERNEL_PRIVATE
  64 /* arp_lookup_ip is obsolete, use inet_arp_lookup */
  65 errno_t arp_lookup_ip(ifnet_t interface, const struct sockaddr_in *ip_dest,
  66                         struct sockaddr_dl *ll_dest, size_t ll_dest_len, route_t hint,
  67                         mbuf_t packet);
  68 #endif /* KERNEL_PRIVATE */
  69
  70 /*!
  71         @function inet_arp_handle_input
  72         @discussion This function should be called by code that handles
  73                 inbound arp packets. The caller should parse the ARP packet to
  74                 pull out the operation and the relevant addresses. If a response
  75                 is required, the proto_media_send_arp function will be called.
  76
  77                 This function will lookup the sender in the routing table and
  78                 add an arp entry if necessary. Any queued packets waiting for
  79                 the arp resolution will also be transmitted.
  80         @param interface The interface the packet was received on.
  81         @param arp_op The arp operation, ARPOP_REQUEST or ARPOP_REPLY
  82         @param sender_hw The sender hardware address from the arp payload.
  83         @param sender_ip The sender IP address from the arp payload.
  84         @param target_ip The target IP address from the arp payload.
  85         @result 0 on success or an errno error value on failure.
  86  */
  87 #ifdef BSD_KERNEL_PRIVATE
  88 #define inet_arp_handle_input arp_ip_handle_input
  89 #else
  90 errno_t inet_arp_handle_input(ifnet_t ifp, u_int16_t arpop,
  91                         const struct sockaddr_dl *sender_hw,
  92                         const struct sockaddr_in *sender_ip,
  93                         const struct sockaddr_in *target_ip);
  94 #endif /* KERNEL_PRIVATE */
  95 #ifdef KERNEL_PRIVATE
  96 /* arp_ip_handle_input is obsolete, use inet_arp_handle_input */
  97 errno_t arp_ip_handle_input(ifnet_t ifp, u_int16_t arpop,
  98                         const struct sockaddr_dl *sender_hw,
  99                         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 */
 127 #define inet_arp_init_ifaddr    arp_ifinit
 128 #else
 129 void    inet_arp_init_ifaddr(ifnet_t interface, ifaddr_t ipaddr);
 130 #endif
 131
 132 #endif _NETINET_IN_ARP_H_