/**********************************************************
			Checksum.h
provide checksum functions using 1's complement for both IP 
header checksum and ICMP checksum

***********************************************************/
#ifndef SR_CHECKSUM_H

#define SR_CHECKSUM_H

#include <stdio.h>
#include "sr_protocol.h"
#include "sr_arp.h"
#include <string.h>
#include <arpa/inet.h>
#include "stdlib.h"


/*
*  Author: Denny Chen Dai
*
*  Compute checksum for outgoing packet, store checksum field 
*  
*  base: the beginning of the data chunck
*  checksum: the field for storing 16bit checksum 
*  packet_size: number of bytes (8bit)
*/
void sr_checksum_send(uint16_t *, uint16_t *, int);

/*
*	Author: Denny Chen Dai
* 	Perform error checksum on receiving packet
* 	
*	base: the base pointer of the packet field
* 	packet_size: number of bytes
*   Return: if no error, return 1, else return 0
*/
int sr_checksum_receive(uint16_t *, int);


#endif