// -------------------------------------------------------------------------
//  udp.c
//
//  29.12.2003, J. Ahrensfeld
//
// -------------------------------------------------------------------------
#include "ethernet.h"
#include "ipv4.h"
#include "udp.h"
#include "string.h"

// -------------------------------------------------------------------------
// Testing
uint8_t *UDP_create(packet_t *pPacket, uint8_t *inet_addr_src, uint16_t port_src, uint8_t *inet_addr_dst, uint16_t port_dst, void const *pUDP_payload, uint16_t len)
{
	uint16_t sum;
	UDP *pUDP;
	UDPPP pseudo_hdr;
	uint8_t *pData;

	pUDP = (UDP*)IPV4_create(pPacket, IP_TYPE_UDP, sizeof(UDP)+len, inet_addr_src, inet_addr_dst);

	// Fill UDP header
	pUDP->src_port = port_src;
	pUDP->dst_port = port_dst;
	pUDP->len = len + sizeof(UDP);
	pUDP->chksum = 0x0000;

	// Fill pseudo header
	memcpy(&pseudo_hdr.inet_addr_src, inet_addr_src, 4);
	memcpy(&pseudo_hdr.inet_addr_dst, inet_addr_dst, 4);
	pseudo_hdr.proto = IP_TYPE_UDP;
	pseudo_hdr.len = len + sizeof(UDP);

	// Calculate checksums
	pUDP->chksum = ~IPv4ChkSum((uint16_t*)&pseudo_hdr, pUDP->chksum, sizeof(UDPPP));

	// Commit header
	pData = (uint8_t*)Eth_pkt_append(pPacket, sizeof(UDP));

	// Commit data
	if (pUDP_payload)
	{
		memcpy(pData, pUDP_payload, len);
		return Eth_pkt_append(pPacket, len);
	}

	return pData;

}

void UDP_append(packet_t *pPacket, void const *pData, uint16_t len)
{
	// Commit data
	if (pData)
	{
		memcpy(pPacket->pData, pData, len);
		Eth_pkt_append(pPacket, len);
	}
}