/*
 *  wol.c
 *  
 *  Created by Sékiltoyai on 05/03/09.
 *
 */

#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <strings.h>
#include <unistd.h>
#include <net/bpf.h>
#include <netinet/in.h>
#include <net/if.h>
#include <net/if_arp.h>
#include <net/if_dl.h>
#include <net/if_types.h>
#include <netinet/if_ether.h>
#include <sys/ioctl.h>
#include <sys/socket.h>

#define BASE_DEV "/dev/bpf0"
#define MAGIC_LEN 6
#define REPEAT_TIME 16

struct wol_packet
{
	struct ether_header hdr;
	u_char magic_packet[MAGIC_LEN];
	u_char repeat_addr[ETHER_ADDR_LEN][REPEAT_TIME];
};

int wol_init(int *fd, const char *iface)
{
	
	char device[] = BASE_DEV;
	device[strlen(device)-1] = '0';
	
	while((*fd=open(device, O_RDWR))<0)
	{
		
		if(errno != EBUSY)
		{
			printf("Erreur open : %d\n", errno);
			return -1;
		}
		
		if( (++device[strlen(device)-1]) > '9' )
		{
			printf("Erreur périphérique bpf*");
			return -1;
		}
		
	}
	
	int buflen = 128;
	if(ioctl(*fd, BIOCSBLEN, &buflen)<0)
	{
		printf("Erreur ioctl_buflen : %d\n", errno);
		return -1;
	}
	
	struct ifreq ifrequest;
	strncpy(ifrequest.ifr_name, iface, sizeof(iface));
	if(ioctl(*fd, BIOCSETIF, &ifrequest)<0)
	{
		printf("Erreur ioctl_setif : %d\n", errno);
		return -1;
	}
	
	return 0;
	
}


int wol_send(int fd, u_char dhost[ETHER_ADDR_LEN])
{
	
	struct wol_packet *msg = malloc( sizeof(struct wol_packet) );
	
	memcpy(msg->hdr.ether_dhost, dhost, ETHER_ADDR_LEN);
	bzero(msg->hdr.ether_shost, ETHER_ADDR_LEN);
	msg->hdr.ether_type = 0;
	
	memset(msg->magic_packet, 0xff, MAGIC_LEN);
	
	void *repeat_pos = msg->repeat_addr;
	void *repeat_end = msg->repeat_addr + REPEAT_TIME*ETHER_ADDR_LEN*sizeof(u_char);
	while(repeat_pos<repeat_end)
	{
		memcpy(repeat_pos, dhost, ETHER_ADDR_LEN*sizeof(u_char));
		repeat_pos += ETHER_ADDR_LEN*sizeof(u_char);
	}
	
	int res;
	if((res=write(fd, msg, sizeof(struct wol_packet)))<0)
	{
		printf("Erreur write : %d\n", errno);
		return -1;
	}
	printf("%d\n",res);
	
	return 0;
	
}

int wol_close(int fd)                                                                                                   
{                                                                                                                       
	
	if(close(fd))                                                                                                   
	{                                                                                                               
		printf("Erreur close : %d\n", errno);                                                                   
		return -1;                                                                                              
	}                                                                                                               
	
	return 0;                                                                                                       
	
} 


int main(int argc, char *argv[])
{

	int fd;
	u_char dhost[ETHER_ADDR_LEN] = {0x00,0x11,0x11,0x28,0x2c,0x39};
	
	wol_init(&fd, "en0");
	wol_send(fd, dhost);
	wol_close(fd);
	
}