add NdpToArpPacketHandler

src/NdpToArpPacketHandler.cpp

@@ -0,0 +1,99 @@
+#include "NdpToArpPacketHandler.h"
+#include <tins/ethernetII.h>
+#include <tins/arp.h>
+#include <tins/icmpv6.h>
+#include <tins/ipv6.h>
+#include <tins/ip_address.h>
+#include <tins/ipv6_address.h>
+#include "IpAddressTranslator.h"
+
+NdpToArpPacketHandler::NdpToArpPacketHandler()
+{
+}
+
+NdpToArpPacketHandler::~NdpToArpPacketHandler()
+{
+}
+
+bool NdpToArpPacketHandler::handle(IN const Tins::PDU & pdu, IN IPacketHandler * callBackHandler)
+{
+	// callback handler requeried
+	if (callBackHandler == nullptr)
+	{
+		return false;
+	}
+
+	// get ipv6 packet
+	const Tins::IPv6 * ipPdu = pdu.find_pdu<Tins::IPv6>();
+	if(ipPdu == nullptr)
+	{
+		return false;
+	}
+
+	// get ipcmp packet, which has the target address field
+	const Tins::ICMPv6 * ndpPdu = pdu.find_pdu<Tins::ICMPv6>();
+	if(ndpPdu == nullptr || !ndpPdu->has_target_addr())
+	{
+		return false;
+	}
+
+	// translate target address to ipv4
+	const Tins::IPv6Address & targetIp6Address = ndpPdu->target_addr();
+	UPtrIPv4Address targetIp = std::make_unique<Tins::IPv4Address>(IpAddressTranslator::toIpv4AddressBytes(targetIp6Address));
+
+	// create arp pdu
+	Tins::ICMPv6::hwaddress_type senderHwAddr;
+	const Tins::ICMPv6::option * ptrHwAddressOption;
+	const Tins::ICMPv6::Types ndpType = ndpPdu->type();
+	if (ndpType == Tins::ICMPv6::Types::NEIGHBOUR_SOLICIT)
+	{
+		ptrHwAddressOption = ndpPdu->search_option(Tins::ICMPv6::OptionTypes::SOURCE_ADDRESS);
+		if (ptrHwAddressOption == nullptr)
+		{
+			const Tins::EthernetII * ethNsPdu = pdu.find_pdu<Tins::EthernetII>();
+			if(ethNsPdu == nullptr)
+			{
+				return false;
+			}
+
+			senderHwAddr = ethNsPdu->src_addr();
+		}
+		else
+		{
+			senderHwAddr = ptrHwAddressOption->to<Tins::ICMPv6::hwaddress_type>();
+		}
+
+		// create arp request
+		const Tins::IPv6Address & senderIp6Address = ipPdu->src_addr();
+		UPtrIPv4Address senderIp = std::make_unique<Tins::IPv4Address>(IpAddressTranslator::toIpv4AddressBytes(senderIp6Address));
+		Tins::EthernetII arpRequest = Tins::ARP::make_arp_request(*targetIp, *senderIp, senderHwAddr);
+		return callBackHandler->handle(arpRequest, this);
+	}
+
+	if (ndpType == Tins::ICMPv6::Types::NEIGHBOUR_ADVERT)
+	{
+		const Tins::EthernetII * ethNaPdu = pdu.find_pdu<Tins::EthernetII>();
+		if(ethNaPdu == nullptr)
+		{
+			return false;
+		}
+
+		ptrHwAddressOption = ndpPdu->search_option(Tins::ICMPv6::OptionTypes::TARGET_ADDRESS);
+		if (ptrHwAddressOption == nullptr)
+		{
+			senderHwAddr = ethNaPdu->src_addr();
+		}
+		else
+		{
+			senderHwAddr = ptrHwAddressOption->to<Tins::ICMPv6::hwaddress_type>();
+		}
+
+		// create arp reply
+		const Tins::IPv6Address & dstIp6Address = ipPdu->dst_addr();
+		UPtrIPv4Address dstIp = std::make_unique<Tins::IPv4Address>(IpAddressTranslator::toIpv4AddressBytes(dstIp6Address));
+		Tins::EthernetII arpReply = Tins::ARP::make_arp_reply(*dstIp, *targetIp, ethNaPdu->dst_addr(), senderHwAddr);
+		return callBackHandler->handle(arpReply, this);
+	}
+
+	return false;// callBackHandler->handle(outestPdu, this);
+}