SCANNER D'IP MULTITHREAD

#include <winsock2.h>
#include <stdio.h>
#include <stdlib.h>
#pragma comment(lib, "ws2_32.lib")

struct config
{
 SOCKET sock;
 SOCKADDR_IN sin;
 int ip;
 HANDLE hthread;
};

int nthread;

DWORD WINAPI connection( LPVOID Param )
{
 struct config * conf = (struct config *)Param;
 WSADATA WSAData;
 WSAStartup(MAKEWORD(2,0), &WSAData);
 conf->sin.sin_addr.s_addr	= ntohl(conf->ip);
 conf->sin.sin_family		= AF_INET;
 conf->sin.sin_port		    = htons(555);
 conf->sock = socket(AF_INET,SOCK_STREAM,0);
 bind(conf->sock, (SOCKADDR *)&conf->sin, sizeof(conf->sin));
 if ( !connect(conf->sock, (SOCKADDR *)&conf->sin, sizeof(conf->sin)) )
     printf("***connection to %s succed\n",inet_ntoa(conf->sin.sin_addr));
 nthread++;
 closesocket(conf->sock);
 WSACleanup();
 CloseHandle(conf->hthread);
 free(conf);
}

int main(int argc, char *argv[])
{
 int startip;
 int endip;
 struct config * conf = NULL;

 if ( argc > 2 )
 {
  startip = htonl(inet_addr(argv[1]));
  endip = htonl(inet_addr(argv[2]));
  nthread = 100;

  for (;startip <= endip;startip++)
  {
   while ( !nthread ) _sleep(100);
   conf = (struct config *) malloc(sizeof(struct config) );
   conf->ip = startip;
   conf->hthread = CreateThread(NULL, 0, &connection, conf, 0, 0);
   nthread--;
  }
 }
 else
  printf("Usage : scan.exe ip_start ip_end\n");
 system("pause");
 return 0;
}