Receiving Data on an ATM Socket PVC Server Example Program

/*
 * ATM Sockets PVC Server Example
 *
 * This program opens a PVC an receives data on it.
 *
 */
#include <stdio.h>
#include <stddef.h>
#include <stdlib.h>
#include <errno.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <sys/ndd_var.h>
#include <sys/atmsock.h>
#define BUFF_SIZE    8192
char    buff[BUFF_SIZE];
main(argc, argv)
        int argc;
        char *argv[];
{
   int                     s;       // Socket file descriptor
   int                     error;   // Function return code
   sockaddr_ndd_atm_t      addr;    // ATM Socket Address
   // Create a socket in the AF_NDD domain of type SOCK_CONN_DGRAM
   // and NDD_PROT_ATM protocol.
   s = socket(AF_NDD, SOCK_CONN_DGRAM, NDD_PROT_ATM);
   if (s == -1) {          // Socket either returns the file descriptor
      perror("socket");    // or a -1 to indicate an error.
      exit(-1);
   }
   // The bind command associates this socket with a particular
   // ATM device, as specified by addr.sndd_atm_nddname.
   addr.sndd_atm_len = sizeof(addr);
   addr.sndd_atm_family = AF_NDD;
   strcpy( addr.sndd_atm_nddname, "atm0" ); // The name of the ATM device
                                            // which is to be used.
   error = bind( s, (struct sockaddr *)&addr, sizeof(addr) );
   if (error) {         // An error from bind would indicate the
      perror("bind");   // requested ATM device is not available.
      exit(-1);         // Check smitty devices.
   } /* endif */
   // To open a PVC, the addr.sndd_atm_vc_type field of the
   // sockaddr_ndd_atm is set to CONN_PVC.  The VPI and VCI are
   // specified in the fields sndd_atm_addr.number.addr[0] and
   // sndd_atm_addr.number.addr[1].
   addr.sndd_atm_vc_type = CONN_PVC;         // Indicates PVC
   addr.sndd_atm_addr.number.addr[0] = 0;    // VPI
   addr.sndd_atm_addr.number.addr[1] = 15;   // VCI
   error = connect( s, (struct sockaddr *)&addr, sizeof(addr) );
   if (error) {            // A connect error may indicate that
      perror("connect");   // the VPI/VCI is already in use.
      exit(-1);
   } /* endif */
   while (1) {
      error = recv( s, buff, BUFF_SIZE, 0 );
      if (error < 0 ) {                         // Send returns -1 to
         perror("recv");                        // to indicate an error.
         exit(-1);                              // The errno is set an can
      } else {                                  // be displayed with perror.
         printf("received %d bytes\n", error ); // Or it returns the number
      }                                         // of bytes received
   } /* endwhile */
   exit(0);
}