/*
 * 
 *        ARPS 1.0 [ arp packets sender / shaping ]
 *
 * "THE BEER-WARE LICENSE" (by Poul-Henning Kamp, Revision 42)
 * emdel wrote this file. As long as you retain this notice
 * you can do whatever you want with this stuff. If we meet some day, and you
 * think this stuff is worth it, you can buy me a beer in return.
 * 
 * emdel
 *
 */


#include <unistd.h>
#include <stdio.h>
#include <string.h>
#include <netinet/ether.h>
#include <arpa/inet.h>
#include <errno.h>
#include <stdlib.h>
#include <libnet.h>

#define INFO "Copyright (c) 2008 emdel <emdel@playhack.net> "
#define WHAT "ARPS 1.0 [ arp packets sender / shaping ]"

void die( void );
int send_arp( libnet_t *handler, char *device, char *ip, u_short arptype );


int main( int argc, char **argv )
{
	int ret, i, v;
	int npacket;
	char *device;
	char *ip;
	libnet_t *handler;
	char err[LIBNET_ERRBUF_SIZE];

	ret = getuid( );
	if( ret != 0 )
	{
		fprintf( stderr, "You must be root!\n" );
		exit( 25 );
	}

	if( argc != 4 )
	{
		fprintf( stderr, "Usage %s < interface > < ip address > < number of packet > \n" , argv[0] );
		exit( 25 );
	}

	fprintf( stdout, "\n\t\t %s \n\n \t\t %s \n\n " , WHAT, INFO );

	device = argv[1];
	handler = libnet_init( LIBNET_LINK, device, err );
	if( handler == NULL )
	    die( );

	npacket = atoi( argv[3] );

	ip = argv[2];
	
	for( i = 0; i <= npacket; i++ )
	{
		v = send_arp( handler, device, ip, ARPOP_REQUEST );
		if( v < 0 ) 
			printf("-1 -> error during the REQUEST sending\n"); 
		else
			printf("0 -> success arp REQUEST!\n" );
		/*v = send_arp( handler, device, ip, ARPOP_REPLY );
		if( v < 0 ) 
			printf("-1 -> error during the REPLY sending \n"  );  
		else
			printf("0 -> success arp REPLY!\n" );*/
	}

	libnet_destroy( handler );


	
return( v < 0 ? -1 : 0 );

}


void die( void )
{
	fprintf( stderr, "An error occured\n" );
	exit( 25 );
}

int send_arp( libnet_t *handler, char *device, char *ip, u_short arptype )
{

	int r;
	in_addr_t ind;

	u_char src[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
	u_char dst[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};

	ind = inet_addr( ip );

	libnet_autobuild_arp(
                        arptype,
                        (u_int8_t *)ether_aton(  ether_ntoa( ( struct ether_addr *)src ) ) ,
                        (u_int8_t *)&ind,
                        (u_int8_t *)ether_aton(  ether_ntoa( ( struct ether_addr *)dst ) ),
                        (u_int8_t *)&ind,
                        handler
                        );
	
		
	libnet_autobuild_ethernet(
                        (u_int8_t *)ether_aton( ether_ntoa( ( struct ether_addr *)dst ) ),
                        ETHERTYPE_ARP,
                        handler
                        );
	

	r = libnet_write( handler );
	fprintf( stdout, "ip_src: %s [ mac: %s ] --> ip_dst: %s [ mac: %s ]\n" , ip, ether_ntoa( ( struct ether_addr *)src ), ip, ether_ntoa( ( struct ether_addr *)src ) );
	if( r == -1 )
		printf( "fatal error %s\n" , strerror( errno ) );

return r;

}