#include "EthDot3Layer.h"
#include "EndianPortable.h"
#include "PayloadLayer.h"
#include "LLCLayer.h"

namespace pcpp
{

EthDot3Layer::EthDot3Layer(const MacAddress& sourceMac, const MacAddress& destMac, uint16_t length) : Layer()
{
	const size_t headerLen = sizeof(ether_dot3_header);
	m_DataLen = headerLen;
	m_Data = new uint8_t[headerLen];
	memset(m_Data, 0, headerLen);

	ether_dot3_header* ethHdr = (ether_dot3_header*)m_Data;
	destMac.copyTo(ethHdr->dstMac);
	sourceMac.copyTo(ethHdr->srcMac);
	ethHdr->length = be16toh(length);
	m_Protocol = Ethernet;
}

void EthDot3Layer::parseNextLayer()
{
	if (m_DataLen <= sizeof(ether_dot3_header))
		return;

	uint8_t* payload = m_Data + sizeof(ether_dot3_header);
	size_t payloadLen = m_DataLen - sizeof(ether_dot3_header);

	if (LLCLayer::isDataValid(payload, payloadLen))
		m_NextLayer = new LLCLayer(payload, payloadLen, this, m_Packet);
	else
		m_NextLayer = new PayloadLayer(payload, payloadLen, this, m_Packet);
}

std::string EthDot3Layer::toString() const
{
	return "IEEE 802.3 Ethernet, Src: " + getSourceMac().toString() + ", Dst: " + getDestMac().toString();
}

bool EthDot3Layer::isDataValid(const uint8_t* data, size_t dataLen)
{
	if (dataLen >= sizeof(ether_dot3_header))
	{
		/**
		 * LSAPs: ... Such a length must, when considered as an
		 * unsigned integer, be less than 0x5DC or it could be mistaken as
		 * an Ethertype...
		 *
		 * From: https://tools.ietf.org/html/rfc5342#section-2.3.2.1
		 * More: IEEE Std 802.3 Clause 3.2.6
		 */
		return be16toh(*(uint16_t*)(data + 12)) <= (uint16_t)0x05DC;
	}
	else
	{
		return false;
	}
}

} // namespace pcpp