arp.cpp

des加密算法

#include "stdafx.h"
#include "PIPMasq.h"

////////////////////////// ArpMgr /////////////////////////////////

ArpMgr::ArpMgr(PseudIF* pseudIF)
{
	m_pseudIF = pseudIF;

	m_waitFlag = false;

	m_arpLock_out = CreateEvent(0, FALSE, FALSE, 0);
	m_arpLock_in = CreateEvent(0, FALSE, FALSE, 0);
}


ArpMgr::~ArpMgr()
{
	printf(".....ArpMgr is destructed.\n"); 
//	Sleep(1000);
}

bool
ArpMgr::arpSendRecv(__u32 hostTypeIPAddr32, char* mac_ethAlen)
{
	_ipAddr_u32_n = htonl(hostTypeIPAddr32);
	_ipAddr_u32_h = hostTypeIPAddr32;
	
	if ((hostTypeIPAddr32 & m_pseudIF->m_subWanIPAddr_u32) 
		!= m_pseudIF->m_netWanAddr_u32 )
	{
		// return default gateway mac address
		memcpy(mac_ethAlen, m_pseudIF->m_defaultGWMacAddr, ETH_ALEN);
		return true;
	}

	struct arpPacket _ar;

	// Destination: ff:ff:ff:ff:ff:ff (ff:ff:ff:ff:ff:ff)
	_ar.ethhdr.h_dest[0]=0xff;
	_ar.ethhdr.h_dest[1]=0xff;
	_ar.ethhdr.h_dest[2]=0xff;
	_ar.ethhdr.h_dest[3]=0xff;
	_ar.ethhdr.h_dest[4]=0xff;
	_ar.ethhdr.h_dest[5]=0xff;	

	// Source:
 	memcpy(_ar.ethhdr.h_source, m_pseudIF->m_pseudMacAddr, ETH_ALEN);

	// Type
	_ar.ethhdr.h_proto = htons(ETH_P_ARP);

	//// Step.2 Make Arp Header + Data
	// header
	_ar.arphdr.ar_hrd = htons(ETH_P_802_3);		// Hardware type: Ethernet(0x0001)
	_ar.arphdr.ar_pro = htons(ETH_P_IP);		// Protocol type: IP(0x0800)
	_ar.arphdr.ar_hln = ETH_ALEN;				// Hardware size: 6(0x06)
	_ar.arphdr.ar_pln = 4;						// Protocol size; 4
	_ar.arphdr.ar_op  = htons(ARPOP_REQUEST);	// Opcode: request (0x0001)

	// data
	// Sender hardware address:
	memcpy(_ar.arphdr.ar_sha, m_pseudIF->m_pseudMacAddr, ETH_ALEN);

	// Sender protocol address:

	__u32 _pseudIPAddr_u32_n = ntohl(m_pseudIF->m_pseudIPAddr_u32);
	memcpy(_ar.arphdr.ar_sip, (void *)(&(_pseudIPAddr_u32_n)), 4);

	// Target hardware addresse: 00:00:00:00:00:00
	memset(_ar.arphdr.ar_tha, 0, sizeof(_ar.arphdr.ar_tha));

	// Target protocol address:
	memcpy(_ar.arphdr.ar_tip, (void *)(&_ipAddr_u32_n), 4);

	// Packet Release !!
	m_pseudIF->releasePacket((void *)&_ar, sizeof(_ar));
	
	// Wait ARP reply
	m_waitFlag = true;

	SetEvent(m_arpLock_in);
	if (WaitForSingleObject(m_arpLock_out,INFINITE) != WAIT_OBJECT_0)// Wait 1 second.
		return false;

	memcpy(mac_ethAlen, m_getMacAddr, ETH_ALEN);

	m_waitFlag = false;

	return true;
}

bool
ArpMgr::analizeArpPacket2(char *pChar, int dataLen)
{
	if (m_waitFlag == false)
		return false;
	
	struct arpPacket *p_arp = (struct arpPacket *)pChar;

	if (memcmp(p_arp->arphdr.ar_sip, (void *)(&_ipAddr_u32_n), sizeof(unsigned char[4])) != 0)
	{
		return false;
	}

	if (WaitForSingleObject(m_arpLock_in, 1000) != WAIT_OBJECT_0)  // Wait 1 second.
		return false;
		
	memcpy(m_getMacAddr, p_arp->arphdr.ar_sha, ETH_ALEN);

	SetEvent(m_arpLock_out);

	return true;
}



bool
ArpMgr::analizeArpPacket(char *pChar, int dataLen)
{
	struct arpPacket *p_arp = (struct arpPacket *)pChar;

	if (p_arp->arphdr.ar_op == htons(ARPOP_REPLY))
	{
		return analizeArpPacket2(pChar, dataLen);
	}

	if (p_arp->arphdr.ar_op != htons(ARPOP_REQUEST))
		return false;

	__u32 _pseudIPAddr_n_u32 = htonl(m_pseudIF->m_pseudIPAddr_u32);

	if (memcmp(p_arp->arphdr.ar_tip, &_pseudIPAddr_n_u32, sizeof(unsigned char[4])) != 0)
		return true;

	// Ethernet Address exchange
	memcpy(p_arp->ethhdr.h_dest, p_arp->ethhdr.h_source, ETH_ALEN);
	memcpy(p_arp->ethhdr.h_source, m_pseudIF->m_pseudMacAddr, ETH_ALEN);

	// Making Arp Packet(Reply)
	
	// The following four lines should be same.
	//p_arp->arphdr.ar_hrd = htons(ETH_P_802_3);	// Hardware type: Ethernet(0x0001)
	//p_arp->arphdr.ar_pro = htons(ETH_P_IP);		// Protocol type: IP(0x0800)
	//p_arp->arphdr.ar_hln = ETH_ALEN;				// Hardware size: 6(0x06)
	//p_arp->arphdr.ar_pln = 4;						// Protocol size; 4
	p_arp->arphdr.ar_op  = htons(ARPOP_REPLY);		// Opcode: request (0x0002)

	/* Remote IP address		*/
	memcpy(p_arp->arphdr.ar_tip,  p_arp->arphdr.ar_sip, 4);	

	/* Remote hardware address	*/
	memcpy(p_arp->arphdr.ar_tha, p_arp->ethhdr.h_dest, ETH_ALEN);	

	/* Local IP address	*/
	memcpy(p_arp->arphdr.ar_sip, &_pseudIPAddr_n_u32, 4);	

	/* Local hardware address	*/
	memcpy(p_arp->arphdr.ar_sha, m_pseudIF->m_pseudMacAddr, ETH_ALEN);	

	// Packet Release !!
	m_pseudIF->releasePacket(	(void *)pChar, dataLen);

	return true;

};