/* dgrecv.c */

/* Demonstates the use of recvfrom for datagram transfer */

#define begin {
#define end   }

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

char buf[100];
struct hostent *hp;
struct hostent *gethostbyname();
struct sockaddr_in name;
struct sockaddr_in sname;
int namelen;

main(argc, argv)
int argc;
char *argv[];
begin
   int i;
   unsigned char c;
   int sock;
   int netaddr;
   int status;

/* Create datagram socket */

   sock = socket(PF_INET, SOCK_DGRAM, 0);
   if (sock < 0)
   begin
      printf("Socket create failed \n");
      exit(1);
   end

/* Get host network address from command line parm */

   hp = gethostbyname(argv[1]);
   if (hp == 0)
   begin
      printf("Host %s not found\n", argv[1]);
      exit(1);
   end
   bcopy((char *)hp->h_addr, (char *)&name.sin_addr, hp->h_length);

/* Fill in protocol family and port # from command line then */
/* bind the socket to the specified address.                 */

   name.sin_family = AF_INET;
   name.sin_port = htons(atoi(argv[2]));
   status = bind(sock, (struct sockaddr *)&name, sizeof(name));
   printf("Bind status = %d \n", status);
   if (status < 0)
     exit(1);

/* Wait for someone to send me a datagram */

   namelen = sizeof(struct sockaddr_in);
   status = recvfrom(sock, buf, sizeof(buf), 0,
               (struct sockaddr *)&sname, &namelen);

   printf("status = %d \n", status);
   printf("Msg = %s \n", buf);

   printf("Sender net address = ");
   for (i = 0; i < hp->h_length; i++)
   begin
      c = *((char *)&sname.sin_addr + i);
      printf(" %2x", c);
   end
   printf("\n");

   printf("Sender port address = %x \n", sname.sin_port);

end