www.pudn.com > zlIP-8051-rtl8019as.zip > ARP.c

/* 
 * Copyright (c) 2003 Electric Application Laboratory of NAN KAI University 
 * All rights reserved. 
 * 
 * Redistribution and use in source and binary forms, with or without modification, 
 * are permitted provided that the following conditions are met: 
 * 
 * 1. Redistributions of source code must retain the above copyright notice, 
 *    this list of conditions and the following disclaimer. 
 * 2. Redistributions in binary form must reproduce the above copyright notice, 
 *    this list of conditions and the following disclaimer in the documentation 
 *    and/or other materials provided with the distribution. 
 * 3. The name of the author may not be used to endorse or promote products 
 *    derived from this software without specific prior written permission. 
 * 
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT 
 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 
 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 
 * OF SUCH DAMAGE. 
 * 
 * Author: Li Zhanglin  
 * 
 */ 
 
#include "..\GloblDef\GloblDef.h" 
#include "..\TCPIP\TCPIPmem.h" 
#include "..\TCPIP\IP.h" 
#include "..\Netif\etherif.h" 
#include "..\Netif\ARP.h" 
#include "..\TCPIP\Netif.h" 
 
BYTE DT_XDATA EtherAddrAny[ETHER_ADDR_LEN] = {0xff,0xff,0xff,0xff,0xff,0xff}; 
 
/* entry table */ 
struct SARPEntry DT_XDATA ARPTable[ARP_ENTRY_MAX_NUM]; 
 
/* arp init */ 
void ARPInit() REENTRANT_MUL 
{ 
	BYTE i; 
 
	/* set every unit in arp tabel invalid */ 
	for(i = 0; i < ARP_ENTRY_MAX_NUM; i++) 
		ARPTable[i].time = 0; 
} 
 
/* construct a arp query packet and return it */ 
struct SMemHead DT_XDATA * ARPQuery(struct SNetIf DT_XDATA *NetIf,IP_ADDR DestIP) REENTRANT_SIG 
{ 
	struct SMemHead DT_XDATA *MemHead; 
	struct SEtherHead DT_XDATA *EtherHead; 
	struct SARPPacket DT_XDATA *ARPPacket; 
 
	/* allocate a packet mem */ 
	if((MemHead = MemAllocate(sizeof(struct SARPPacket) +  
		sizeof(struct SEtherHead))) == NULL) 
		return NULL; 
	 
	EtherHead = (struct SEtherHead DT_XDATA *)(MemHead->pStart); 
	ARPPacket = (struct SARPPacket DT_XDATA *)(MemHead->pStart +  
		sizeof(struct SEtherHead)); 
 
	/* fill Ether head */ 
	MemCopy(EtherHead->DestAddr,EtherAddrAny,ETHER_ADDR_LEN); 
	MemCopy(EtherHead->ScrAddr , 
		((struct SEtherDevice DT_XDATA *)(NetIf->Info))->Addr,ETHER_ADDR_LEN); 
	EtherHead->type = htons(ETHER_TYPE_ARP); 
 
	/* fill arp head */ 
	ARPPacket->HardWareAddrLen	= ARP_HARDWARE_ADDR_LEN_ETHER; 
	ARPPacket->HardwareType		= htons(ARP_HARDWARE_TYPE_ETHER); 
	ARPPacket->ProtocolAddrLen	= ARP_PROTOCOL_ADDR_LEN_IP; 
	ARPPacket->ProtocolType		= htons(ARP_PROTOCOL_TYPE_IP); 
	ARPPacket->type				= htons(ARP_TYPE_ARP_REQUEST); 
 
	/* fill arp content */ 
	ARPPacket->IPDestAddr	= DestIP; 
	ARPPacket->IPScrAddr	= NetIf->IPAddr; 
	MemCopy(ARPPacket->EtherDestAddr,EtherAddrAny,ETHER_ADDR_LEN); 
	MemCopy(ARPPacket->EtherScrAddr, 
		((struct SEtherDevice DT_XDATA *)(NetIf->Info))->Addr,ETHER_ADDR_LEN); 
 
	return MemHead; 
} 
 
/* deel with a input arp packet. if send a reply is needed return  
this replay packet, oterhwise return NULL  */ 
struct SMemHead DT_XDATA *ARPInput(struct SMemHead DT_XDATA *MemHead, struct SNetIf DT_XDATA *NetIf) REENTRANT_MUL 
{ 
	struct SEtherHead DT_XDATA *EtherHead; 
	struct SARPPacket DT_XDATA *ARPPacket; 
 
	EtherHead = (struct SEtherHead DT_XDATA *)(MemHead->pStart); 
	ARPPacket = (struct SARPPacket DT_XDATA *)(MemHead->pStart +  
		sizeof(struct SEtherHead)); 
 
	/* which type of arp */ 
	switch(ntohs(ARPPacket->type)) 
	{ 
	case ARP_TYPE_ARP_REQUEST: 
 
		/* if arp request to local host */ 
		if(ARPPacket->IPDestAddr == NetIf->IPAddr) 
		{ 
			/* send arp replay */ 
 
			/* fill Ether head */ 
			MemCopy(EtherHead->DestAddr,ARPPacket->EtherScrAddr,ETHER_ADDR_LEN); 
			MemCopy(EtherHead->ScrAddr, 
				((struct SEtherDevice DT_XDATA *)(NetIf->Info))->Addr,ETHER_ADDR_LEN); 
			EtherHead->type = htons(ETHER_TYPE_ARP); 
 
			/* copy source part to dest part. include Ether addr and  
			Ip addr */ 
			MemCopy(ARPPacket->EtherDestAddr,ARPPacket->EtherScrAddr, 
				(sizeof(IP_ADDR) + ETHER_ADDR_LEN)); 
 
			/* fill source part. include Ether addr and Ip addr*/ 
			ARPPacket->IPScrAddr = NetIf->IPAddr; 
			MemCopy(ARPPacket->EtherScrAddr, 
				((struct SEtherDevice DT_XDATA *)(NetIf->Info))->Addr,ETHER_ADDR_LEN); 
 
			/* arp type */ 
			ARPPacket->type = htons(ARP_TYPE_ARP_REPLY); 
 
			return MemHead; 
		} 
		break; 
 
	case ARP_TYPE_ARP_REPLY: 
		/* add to arp table */ 
		ARPAddEntry(ARPPacket); 
		break; 
	} 
				 
	/* for any case except ARP_TYPE_ARP_REQUEST for this IP,  
	arp packet is released */ 
	MemFree(MemHead); 
 
	/* no packet need send */ 
	return NULL; 
} 
 
/* add a entry to arp table */ 
void ARPAddEntry(struct SARPPacket DT_XDATA *ARPPacket) REENTRANT_MUL 
{ 
	BYTE i; 
	WORD MinTime; 
	BYTE iToReplace;	/* index of entry going to be replace */ 
 
	/* find a free entry */ 
	for(i = 0; i ARPTable[i].time) 
			{ 
				MinTime = ARPTable[i].time; 
				iToReplace = i; 
			} 
		} 
	} 
 
	/* replace the entry */ 
	MemCopy(ARPTable[iToReplace].EtherAddr,ARPPacket->EtherScrAddr, 
		ETHER_ADDR_LEN); 
	ARPTable[iToReplace].IPAddr = ARPPacket->IPScrAddr; 
 
	/* start timer */ 
	ARPTable[iToReplace].time = ARP_ENTRY_TIME_OUT; 
} 
 
/* find IPAddr in arptable copy it to EtherAddr. if can't find return 
false */ 
BOOL ARPFind(BYTE EtherAddr[],IP_ADDR IPAddr) REENTRANT_SIG 
{ 
	BYTE i; 
	for(i = 0; i