/* Example UDP server program                                 */
/* Adapted from http://en.wikipedia.org/wiki/Berkeley_sockets */

#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <unistd.h> /* for close() for socket */
#include <stdlib.h>
#include <arpa/inet.h>

int main(void)
{
  /* create socket and socket address data structure */
  int sock = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
  struct sockaddr_in sa;
  char buffer[1024];
  ssize_t recsize;
  socklen_t fromlen;

  /* init sa with local interface */
  memset(&sa, 0, sizeof sa);
  sa.sin_family = AF_INET;
  inet_pton(AF_INET, "127.0.0.1", &(sa.sin_addr.s_addr));
/*  sa.sin_addr.s_addr = htonl (INADDR_ANY); */

  /* init sa to listening port */
  sa.sin_port = htons(7654);
  fromlen = sizeof(sa);

  /* bind socket to address:port */
  if (-1 == bind(sock,(struct sockaddr *)&sa, sizeof(sa)))
  {
    perror("error bind failed");
    close(sock);
    exit(EXIT_FAILURE);
  }

  /* loop receiving packets */
  for (;;)
  {
    printf ("recv test....\n");

    recsize = recvfrom(sock, (void *)buffer, 1024, 0, (struct sockaddr *)&sa, &fromlen);

    if (recsize < 0) {
      fprintf(stderr, "%s\n", strerror(errno));
      exit(EXIT_FAILURE);
    }

    printf("recsize: %zd\n ", recsize);
    sleep(1);
    printf("datagram: %.*s\n", (int)recsize, buffer);
  }
}