BOOL CARPLayer::Send(unsigned char* ppayload, int length)
{
CIPLayer::IPLayer_HEADER ipHeader;
memcpy( arpHeader.arpData, ppayload, length );
BOOL isCacheAvailable = FALSE;
list<ARP_CACHE_RECORD>::iterator cacheIter = arpCacheTable.begin();
for(cacheIter; cacheIter != arpCacheTable.end(); cacheIter++)
{
if(memcmp((*cacheIter).ipAddress, targetIPAddress, 4) == 0)
{
isCacheAvailable = TRUE;
break;
}
}
//if cache is vaild and complete record
if((isCacheAvailable == TRUE) && ((*cacheIter).isComplete == TRUE))
{
setTargetHardwareAddress((*cacheIter).ethernetAddress);
((CEthernetLayer*)GetUnderLayer())->SetEnetDstAddress((*cacheIter).ethernetAddress);
}
//it is not valid record
else
{
memset(arpHeader.arpTargetHardwareAddress, 0, 6);
((CEthernetLayer*)GetUnderLayer())->SetEnetDstAddress(BROADCAST_ADDR);
}
arpHeader.arpHardwareType = 0x0100;
arpHeader.arpProtocolType = 0x0008;
arpHeader.arpHardwareAddrSize = 0x6;
arpHeader.arpProtocolAddrSize = 0x4;
arpHeader.arpOperationType = ARP_REQUEST;
memcpy(arpHeader.arpSenderHardwareAddress, ownMACAddress, 6);
memcpy(arpHeader.arpSenderIPAddress, ownIPAddress, 4);
memcpy(arpHeader.arpTargetIPAddress, targetIPAddress, 4);
ARP_CACHE_RECORD newRecord;
newRecord.arpInterface = this->adapter;
memset(newRecord.ethernetAddress, 0, 6);
memcpy(newRecord.ipAddress, targetIPAddress, 4);
newRecord.isComplete = FALSE;
arpCacheTable.push_back(newRecord);
BOOL bSuccess = FALSE ;
bSuccess = mp_UnderLayer->Send((unsigned char*)&arpHeader,length+ARP_HEADER_SIZE);
return bSuccess;
}
BOOL CARPLayer::Send(unsigned char* ppayload, int length)
{
memcpy( arpHeader.arpData, ppayload, length );
BOOL bSuccess = FALSE ;
BOOL isCacheSameIP = FALSE; //캐시 이용가능한지.
BOOL isCacheSameMAC = FALSE;
BOOL isGratuitousPacket = FALSE; //gratuitous 발생 했는지.
list<ARP_CACHE_RECORD>::iterator cacheIter = arpCacheTable.begin();
if(memcmp(targetIPAddress, ownIPAddress, 4) == 0) // gratuitous인지 확인.
isGratuitousPacket = TRUE;
else
{
for(cacheIter; cacheIter != arpCacheTable.end(); cacheIter++)// gratuitous 아니라면, cache에 있는 만큼 for구문돌림.
{
if(memcmp((*cacheIter).ipAddress, targetIPAddress, 4) == 0) //보내려는 ip와 같은 ip가 있다면
{
isCacheSameIP = TRUE;
break;
}
if(memcmp((*cacheIter).ethernetAddress, targetMACAddress, 6) == 0)
{
isCacheSameMAC = TRUE;
break;
}
}
}
//if cache is vaild and complete record
if(((isCacheSameIP == TRUE) || (isCacheSameMAC == TRUE)) && ((*cacheIter).isComplete == TRUE)) // 캐시에 사용가능한 것이 존재한다면,
{
setTargetHardwareAddress((*cacheIter).ethernetAddress); //캐시에 있다면 mac 주소를 알게 된 것이므로, 이 mac 주소로 재설정.
((CEthernetLayer*)GetUnderLayer())->m_sHeader.enet_type = next_ethernet_type;
((CEthernetLayer*)GetUnderLayer())->SetEnetDstAddress((*cacheIter).ethernetAddress);// ethernet layer의 mac 주소도 다시 설정.
}
else if(isCacheSameIP == TRUE)
{
}
//it is not valid record
else // 캐시도 없고, gratuitous도 아니고.
{
memset(arpHeader.arpTargetHardwareAddress, 0, 6);
((CEthernetLayer*)GetUnderLayer())->SetEnetDstAddress(BROADCAST_ADDR);
((CEthernetLayer*)GetUnderLayer())->m_sHeader.enet_type = next_ethernet_type;
ARP_CACHE_RECORD newRecord;
newRecord.arpInterface = this->adapter;
memset(newRecord.ethernetAddress, 0, 6);
memcpy(newRecord.ipAddress, targetIPAddress, 4);
newRecord.isComplete = FALSE;
newRecord.lifeTimeCounter = INCOMPLETE_DELETE_TIME;
arpCacheTable.push_back(newRecord);
}
if(next_ethernet_type == ETHER_PROTO_TYPE_IP)
bSuccess = mp_UnderLayer->Send((unsigned char*)ppayload, length);
else
{
// ----정리---
// 1. Gratuitous가 맞다면, 그냥 아무 작업 하지 않고, 패킷 만들어서 보냄.
// 2. 캐시 이용가능하다면, 캐시에 있는 값으로 맥주소 설정해서 보냄.
// 3. 이용가능한 캐시 없고, gratitous가 아니라면 broadcast로 목적지 설정해서 보냄.
arpHeader.arpHardwareType = 0x0100;
arpHeader.arpProtocolType = 0x0008;
arpHeader.arpHardwareAddrSize = 0x6;
arpHeader.arpProtocolAddrSize = 0x4;
arpHeader.arpOperationType = ARP_REQUEST;
memcpy(arpHeader.arpSenderHardwareAddress, ownMACAddress, 6);
memcpy(arpHeader.arpSenderIPAddress, ownIPAddress, 4);
memcpy(arpHeader.arpTargetIPAddress, targetIPAddress, 4);
bSuccess = mp_UnderLayer->Send((unsigned char*)&arpHeader,length+ARP_HEADER_SIZE);
}
return bSuccess;
}
