/* Sample UDP client */

//#include <sys/socket.h>
//#include <netinet/in.h>
//#include <stdio.h>

#define _GNU_SOURCE 1

#include <stdlib.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <unistd.h>
#include <sys/ipc.h>
#include <sys/shm.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <sched.h>
#include <fcntl.h>
#include <string.h>
#include <stdio.h>
#include <errno.h>

#include <syslog.h>
#include <sys/poll.h>
#include <linux/ppdev.h>
#include <linux/parport.h>

#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>

#include <getopt.h>

struct timeval tv;
struct timezone tz;


int waitsok(int sok)
{
  struct timeval stTimeOut;
  fd_set stReadFDS;
  FD_ZERO(&stReadFDS);

  // Timeout of one second
  stTimeOut.tv_sec = 1;
  stTimeOut.tv_usec = 0;
  FD_SET(sok, &stReadFDS);
  return select(sok+1, &stReadFDS, 0, 0, &stTimeOut);
}









int main(int argc, char**argv)
{
  int sockfd,n;
  struct sockaddr_in servaddr,cliaddr;
  unsigned sendbuf[10];
  unsigned recvbuf[10];
  
  if (argc != 2) {
    printf("usage:  powerclient <IP address>\n");
    exit(1);
  }
  
  sockfd=socket(AF_INET,SOCK_DGRAM,0);
  bzero(&servaddr,sizeof(servaddr));
  servaddr.sin_family = AF_INET;
  servaddr.sin_addr.s_addr=inet_addr(argv[1]);
  servaddr.sin_port=htons(124);

  gettimeofday(&tv,&tz);      
  usleep(50000); //50 ms for the peer to have updated the table entry for this second
  sendbuf[0]=54656866;
  sendbuf[1]=tv.tv_sec&255;  
  sendto(sockfd,sendbuf,8,0,(struct sockaddr *)&servaddr,sizeof(servaddr));
rerx:
  gettimeofday(&tv,&tz);  
  if (waitsok(sockfd)) {
    n=recvfrom(sockfd,recvbuf,40,0,NULL,NULL);
    if (n!=20) goto rerx;
    if (recvbuf[0]!=54652345) goto rerx;
    if (recvbuf[1]!=sendbuf[1]) goto rerx;
    printf("%i\n",recvbuf[2]);
  }
}