1 /* Definitions for Address Resolution Protocol. 2 Copyright (C) 1997-2022 Free Software Foundation, Inc. 3 This file is part of the GNU C Library. 4 5 The GNU C Library is free software; you can redistribute it and/or 6 modify it under the terms of the GNU Lesser General Public 7 License as published by the Free Software Foundation; either 8 version 2.1 of the License, or (at your option) any later version. 9 10 The GNU C Library is distributed in the hope that it will be useful, 11 but WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 Lesser General Public License for more details. 14 15 You should have received a copy of the GNU Lesser General Public 16 License along with the GNU C Library; if not, see 17 <https://www.gnu.org/licenses/>. */ 18 19 /* Based on the 4.4BSD and Linux version of this file. */ 20 21 #ifndef _NET_IF_ARP_H 22 23 #define _NET_IF_ARP_H 1 24 #include <sys/cdefs.h> 25 26 #include <sys/types.h> 27 #include <sys/socket.h> 28 #include <stdint.h> 29 30 __BEGIN_DECLS 31 32 /* Some internals from deep down in the kernel. */ 33 #define MAX_ADDR_LEN 7 34 35 36 /* This structure defines an ethernet arp header. */ 37 38 /* ARP protocol opcodes. */ 39 #define ARPOP_REQUEST 1 /* ARP request. */ 40 #define ARPOP_REPLY 2 /* ARP reply. */ 41 #define ARPOP_RREQUEST 3 /* RARP request. */ 42 #define ARPOP_RREPLY 4 /* RARP reply. */ 43 44 /* See RFC 826 for protocol description. ARP packets are variable 45 in size; the arphdr structure defines the fixed-length portion. 46 Protocol type values are the same as those for 10 Mb/s Ethernet. 47 It is followed by the variable-sized fields ar_sha, arp_spa, 48 arp_tha and arp_tpa in that order, according to the lengths 49 specified. Field names used correspond to RFC 826. */ 50 51 struct arphdr 52 { 53 unsigned short int ar_hrd; /* Format of hardware address. */ 54 unsigned short int ar_pro; /* Format of protocol address. */ 55 unsigned char ar_hln; /* Length of hardware address. */ 56 unsigned char ar_pln; /* Length of protocol address. */ 57 unsigned short int ar_op; /* ARP opcode (command). */ 58 #if 0 59 /* Ethernet looks like this : This bit is variable sized 60 however... */ 61 unsigned char __ar_sha[ETH_ALEN]; /* Sender hardware address. */ 62 unsigned char __ar_sip[4]; /* Sender IP address. */ 63 unsigned char __ar_tha[ETH_ALEN]; /* Target hardware address. */ 64 unsigned char __ar_tip[4]; /* Target IP address. */ 65 #endif 66 }; 67 68 69 /* ARP protocol HARDWARE identifiers. */ 70 #define ARPHRD_NETROM 0 /* From KA9Q: NET/ROM pseudo. */ 71 #define ARPHRD_ETHER 1 /* Ethernet 10Mbps. */ 72 #define ARPHRD_EETHER 2 /* Experimental Ethernet. */ 73 #define ARPHRD_AX25 3 /* AX.25 Level 2. */ 74 #define ARPHRD_PRONET 4 /* PROnet token ring. */ 75 #define ARPHRD_CHAOS 5 /* Chaosnet. */ 76 #define ARPHRD_IEEE802 6 /* IEEE 802.2 Ethernet/TR/TB. */ 77 #define ARPHRD_ARCNET 7 /* ARCnet. */ 78 #define ARPHRD_APPLETLK 8 /* APPLEtalk. */ 79 #define ARPHRD_DLCI 15 /* Frame Relay DLCI. */ 80 #define ARPHRD_METRICOM 23 /* Metricom STRIP (new IANA id). */ 81 82 /* Dummy types for non ARP hardware */ 83 #define ARPHRD_SLIP 256 84 #define ARPHRD_CSLIP 257 85 #define ARPHRD_SLIP6 258 86 #define ARPHRD_CSLIP6 259 87 #define ARPHRD_RSRVD 260 /* Notional KISS type. */ 88 #define ARPHRD_ADAPT 264 89 #define ARPHRD_ROSE 270 90 #define ARPHRD_X25 271 /* CCITT X.25. */ 91 #define ARPHRD_PPP 512 92 #define ARPHRD_HDLC 513 /* (Cisco) HDLC. */ 93 #define ARPHRD_LAPB 516 /* LAPB. */ 94 95 #define ARPHRD_TUNNEL 768 /* IPIP tunnel. */ 96 #define ARPHRD_TUNNEL6 769 /* IPIP6 tunnel. */ 97 #define ARPHRD_FRAD 770 /* Frame Relay Access Device. */ 98 #define ARPHRD_SKIP 771 /* SKIP vif. */ 99 #define ARPHRD_LOOPBACK 772 /* Loopback device. */ 100 #define ARPHRD_LOCALTLK 773 /* Localtalk device. */ 101 #define ARPHRD_FDDI 774 /* Fiber Distributed Data Interface. */ 102 #define ARPHRD_BIF 775 /* AP1000 BIF. */ 103 #define ARPHRD_SIT 776 /* sit0 device - IPv6-in-IPv4. */ 104 105 106 /* ARP ioctl request. */ 107 struct arpreq 108 { 109 struct sockaddr arp_pa; /* Protocol address. */ 110 struct sockaddr arp_ha; /* Hardware address. */ 111 int arp_flags; /* Flags. */ 112 struct sockaddr arp_netmask; /* Netmask (only for proxy arps). */ 113 char arp_dev[16]; 114 }; 115 116 /* ARP Flag values. */ 117 #define ATF_COM 0x02 /* Completed entry (ha valid). */ 118 #define ATF_PERM 0x04 /* Permanent entry. */ 119 #define ATF_PUBL 0x08 /* Publish entry. */ 120 #define ATF_USETRAILERS 0x10 /* Has requested trailers. */ 121 #define ATF_NETMASK 0x20 /* Want to use a netmask (only 122 for proxy entries). */ 123 #define ATF_DONTPUB 0x40 /* Don't answer this addresses. */ 124 #define ATF_MAGIC 0x80 /* Automatically added entry. */ 125 126 127 /* Support for the user space arp daemon, arpd. */ 128 #define ARPD_UPDATE 0x01 129 #define ARPD_LOOKUP 0x02 130 #define ARPD_FLUSH 0x03 131 132 struct arpd_request 133 { 134 unsigned short int req; /* Request type. */ 135 uint32_t ip; /* IP address of entry. */ 136 unsigned long int dev; /* Device entry is tied to. */ 137 unsigned long int stamp; 138 unsigned long int updated; 139 unsigned char ha[MAX_ADDR_LEN]; /* Hardware address. */ 140 }; 141 142 __END_DECLS 143 144 #endif /* net/if_arp.h */ 145