#include <stdio.h> // printf/fprintf
#include <stdlib.h>
#include <string.h>

#include <netinet/ip.h> // struct ip
#include <sys/socket.h> // socket()
#include <netinet/in.h> // struct sockadd

#define __FAVOR_BSD
#define _USE_BSD
#include <netinet/udp.h> // struct udp



void udp(char *, int , char * ,  char *  , int  );
unsigned short int in_chksum (unsigned short int *, int);
unsigned long hasard(unsigned long, unsigned long);



char * hexToAscii(char *hex_a_convertir){

	int taille;
	int i;
	char *data;
	char hex[5], *stop;

	hex[0] = '0';
	hex[1] = 'x';
	hex[4] = 0;
	taille = strlen(hex_a_convertir);

	data = (char *)malloc(taille);


	for(i=0;i<taille /2;i++){

		hex[2] = hex_a_convertir[i*2];
		hex[3] = hex_a_convertir[(i*2)+1];
		*(data+i) = (char) strtol(hex, &stop, 16);

	}


	return data;



}


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




printf("initialisation......... \n" );


/*if( strcmp(arg[1] , "") == 0

	while((c = getopt(argc,argv,"s:d:p:h")) != -1)
	{
		switch(c)
		{
			case 's':
				src = optarg;
				printf("\\nIP source:\\t\\t%s",src);
				break;
			case 'd':
				dest = optarg;
				printf("\\nIP de destination:\\t\\t%s",dest);
				break;
			case 'p':
				port = atoi(optarg);
				printf("\\nPort:\\t\\t%d",port);
				break;
			case 'h':
			case '?':
				printf(VERSION"Usage:\\n\\t-s\\tAdresse IP source\\n\\t-d\\tAdresse IP de destination\\n\\t-p\\tNuméro de port\\n");
				exit(0);
			break;
		}
	}
printf("test......... \n" );*/

int port;
sscanf(arg[2],"%i",&port);



udp(arg[1] , port  , arg[3] , hexToAscii(arg[4])  , strlen(arg[4]) /2 );


}

void udp(char *cible, int port  ,  char *spoofed ,  char *donne ,  int taille_donne ) {

int sd;
sd = socket(AF_INET, SOCK_RAW, IPPROTO_RAW);
if (sd == -1) {
fprintf(stderr,"socket() error, root ?\n");
}

unsigned long ip_src = inet_addr(spoofed);; //->spoof adresse
unsigned long ip_dst = inet_addr(cible);
unsigned short p_src =  10;
unsigned short p_dst =  port;
char *data;
struct sockaddr_in sin;

sin.sin_family = AF_INET;
sin.sin_port = p_dst;
sin.sin_addr.s_addr = ip_dst; // dst

struct ip *ip;
struct udphdr *udp;
char *dgm;
char *interface;

int pksize = sizeof(struct ip) + sizeof(struct udphdr) + taille_donne;
dgm = (char *) malloc(pksize);
ip = (struct ip *) dgm;
udp = (struct udphdr *) (dgm + sizeof(struct ip));
data = (char *) (dgm + sizeof(struct ip) + sizeof(struct udphdr));

memset(dgm, 0, pksize);
memcpy((char *) data, donne, taille_donne);

int un = 1;
if (setsockopt(sd, IPPROTO_IP, IP_HDRINCL, (char *)&un, sizeof(un)) == -1)
 {
 fprintf(stderr,"setsockopt()");
 exit(-1);
 }

//entete ip

ip->ip_hl = 0x5;
ip->ip_v = 0x4;
ip->ip_tos = 0x0;
ip->ip_len = sizeof(pksize);
ip->ip_ttl = 64;
ip->ip_off = 0x0;
ip->ip_id = htons(12830);
ip->ip_p = IPPROTO_UDP;
ip->ip_sum = 0x0; // a remplir aprés
ip->ip_src.s_addr = ip_src;
ip->ip_dst.s_addr = ip_dst;



//entete udp

udp->uh_sport = htons(p_src);
udp->uh_dport = htons(p_dst);
udp->uh_ulen = htons(sizeof(struct udphdr ) + taille_donne);
udp->uh_sum = 0;

interface = (char *)malloc(4);
strncpy(interface, "ppp0\0",5);

/*if (setsockopt(sd, SOL_SOCKET, SO_BINDTODEVICE, interface ,  strlen(interface)+1 ) == -1)
 {
 fprintf(stderr,"pb a la specification de l'option\n");
 exit(-1);
 }*/


// envoi
printf("Envoie du paquet........... \n");
if (sendto(sd, dgm, pksize, 0, (struct sockaddr *) &sin,
 sizeof(struct sockaddr)) == -1) {
 fprintf(stderr,"oops, sendto() error\n");
 }
printf("Envoie OK\n");
//libere la memoire
free(dgm);
free(donne);
close(sd);
}

u_short in_chksum (u_short *addr, int len) // taken from papasmurf.c
{
 register int nleft = len;
 register u_short *w = addr;
 register int sum = 0;
 u_short answer = 0;

 while (nleft > 1)
 {
 sum += *w++;
 nleft -= 2;
 }

 if (nleft == 1)
 {
 *(u_char *)(&answer) = *(u_char *)w;
 sum += answer;
 }

 sum = (sum >> 16) + (sum + 0xffff);
 sum += (sum >> 16);
 answer = ~sum;
 return(answer);
}