etharp.h

00001 /**
00002  * @file
00003  * ARP protocol definitions
00004  */
00005 
00006 /*
00007  * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
00008  * All rights reserved.
00009  *
00010  * Redistribution and use in source and binary forms, with or without modification,
00011  * are permitted provided that the following conditions are met:
00012  *
00013  * 1. Redistributions of source code must retain the above copyright notice,
00014  *    this list of conditions and the following disclaimer.
00015  * 2. Redistributions in binary form must reproduce the above copyright notice,
00016  *    this list of conditions and the following disclaimer in the documentation
00017  *    and/or other materials provided with the distribution.
00018  * 3. The name of the author may not be used to endorse or promote products
00019  *    derived from this software without specific prior written permission.
00020  *
00021  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
00022  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
00023  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
00024  * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
00025  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
00026  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
00027  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
00028  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
00029  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
00030  * OF SUCH DAMAGE.
00031  *
00032  * This file is part of the lwIP TCP/IP stack.
00033  *
00034  * Author: Adam Dunkels <adam@sics.se>
00035  *
00036  */
00037 #ifndef LWIP_HDR_PROT_ETHARP_H
00038 #define LWIP_HDR_PROT_ETHARP_H
00039 
00040 #include "lwip/arch.h"
00041 #include "lwip/prot/ethernet.h"
00042 
00043 #ifdef __cplusplus
00044 extern "C" {
00045 #endif
00046 
00047 #ifndef ETHARP_HWADDR_LEN
00048 #define ETHARP_HWADDR_LEN     ETH_HWADDR_LEN
00049 #endif
00050 
00051 /**
00052  * struct ip4_addr_wordaligned is used in the definition of the ARP packet format in
00053  * order to support compilers that don't have structure packing.
00054  */
00055 #ifdef PACK_STRUCT_USE_INCLUDES
00056 #  include "arch/bpstruct.h"
00057 #endif
00058 PACK_STRUCT_BEGIN
00059 struct ip4_addr_wordaligned {
00060   PACK_STRUCT_FIELD(u16_t addrw[2]);
00061 } PACK_STRUCT_STRUCT;
00062 PACK_STRUCT_END
00063 #ifdef PACK_STRUCT_USE_INCLUDES
00064 #  include "arch/epstruct.h"
00065 #endif
00066 
00067 /** MEMCPY-like copying of IP addresses where addresses are known to be
00068  * 16-bit-aligned if the port is correctly configured (so a port could define
00069  * this to copying 2 u16_t's) - no NULL-pointer-checking needed. */
00070 #ifndef IPADDR_WORDALIGNED_COPY_TO_IP4_ADDR_T
00071 #define IPADDR_WORDALIGNED_COPY_TO_IP4_ADDR_T(dest, src) SMEMCPY(dest, src, sizeof(ip4_addr_t))
00072 #endif
00073 
00074  /** MEMCPY-like copying of IP addresses where addresses are known to be
00075  * 16-bit-aligned if the port is correctly configured (so a port could define
00076  * this to copying 2 u16_t's) - no NULL-pointer-checking needed. */
00077 #ifndef IPADDR_WORDALIGNED_COPY_FROM_IP4_ADDR_T
00078 #define IPADDR_WORDALIGNED_COPY_FROM_IP4_ADDR_T(dest, src) SMEMCPY(dest, src, sizeof(ip4_addr_t))
00079 #endif
00080 
00081 #ifdef PACK_STRUCT_USE_INCLUDES
00082 #  include "arch/bpstruct.h"
00083 #endif
00084 PACK_STRUCT_BEGIN
00085 /** the ARP message, see RFC 826 ("Packet format") */
00086 struct etharp_hdr {
00087   PACK_STRUCT_FIELD(u16_t hwtype);
00088   PACK_STRUCT_FIELD(u16_t proto);
00089   PACK_STRUCT_FLD_8(u8_t  hwlen);
00090   PACK_STRUCT_FLD_8(u8_t  protolen);
00091   PACK_STRUCT_FIELD(u16_t opcode);
00092   PACK_STRUCT_FLD_S(struct eth_addr shwaddr);
00093   PACK_STRUCT_FLD_S(struct ip4_addr_wordaligned sipaddr);
00094   PACK_STRUCT_FLD_S(struct eth_addr dhwaddr);
00095   PACK_STRUCT_FLD_S(struct ip4_addr_wordaligned dipaddr);
00096 } PACK_STRUCT_STRUCT;
00097 PACK_STRUCT_END
00098 #ifdef PACK_STRUCT_USE_INCLUDES
00099 #  include "arch/epstruct.h"
00100 #endif
00101 
00102 #define SIZEOF_ETHARP_HDR 28
00103 
00104 /* ARP message types (opcodes) */
00105 enum etharp_opcode {
00106   ARP_REQUEST = 1,
00107   ARP_REPLY   = 2
00108 };
00109 
00110 #ifdef __cplusplus
00111 }
00112 #endif
00113 
00114 #endif /* LWIP_HDR_PROT_ETHARP_H */