#include <stdio.h>
#include <rpc/xdr.h>
#include <fcntl.h>
#include <sys/types.h> 
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include "pers.h"
 
#define SERVICE      "XDRTEST"                 /* Name des Services */        
#define BUFLEN        2048                     /* Pufferlaenge fuer Memory-Stream  */
#define BACKLOG          5                     /* Groesse der listen-Warteschlange */ 
#define LNG_HOST        32                     /* Laenge des Hostnamens */  

main (argc, argv)
         int argc;
         char *argv[]; 
{
    int                     SockDescr1;        /* Socketdescriptor fuer listen */
    int                     SockDescr2;        /* Socketdescriptor fuer Verbindung */
    struct sockaddr_in      Sock1;             /* Lokale Socket-Adresse */
    struct sockaddr_in      Sock2;             /* Socket-Adresse des Partners */
    int                     AddrLength;        /* Laenge der Socket-Adresse */
    struct hostent          *HostPtr;          /* Struktur in /etc/hosts */
    struct servent          *ServicePtr;       /* Struktur in /etc/services */
    char                    LHost[LNG_HOST+1]; /* Eigener Hostname */
    char                    OBuffer[BUFLEN+1]; /* Sendepuffer */
    char                    IBuffer[BUFLEN+1]; /* Empfangspuffer */
    XDR                     xdrs1;             /* XDR-Stream-Handle fuer Senden */
    XDR                     xdrs2;             /* XDR-Stream-Handle fuer Empfang */
    personal                pers1;             /* Personalsatz */
    int                     Length;            /* Laenge der empfangenen Daten */
    int                     NrRead;            /* Ueber Socket empfangene Bytes */
    int                     NrWrite;           /* Ueber Socket gesendete Bytes */

   /*
    * Information fuer eigenen Host besorgen     
    */
    gethostname ( LHost, LNG_HOST );

    if ( ( HostPtr = gethostbyname (LHost) ) == NULL ) {
       fprintf ( stderr, "%s: Host nicht in /etc/hosts vorhanden\n", LHost );
       exit ( 1 );
    }

    memcpy ( (char *) &Sock1.sin_addr, (char *) HostPtr->h_addr, 
                    HostPtr->h_length );

    Sock1.sin_family = HostPtr->h_addrtype;

    if ( ( ServicePtr = getservbyname ( SERVICE, "tcp" ) ) == NULL ) {
       fprintf ( stderr, "Service nicht in /etc/services\n" );
       exit ( 1 );
    }

    Sock1.sin_port = ServicePtr->s_port;
 
   /*
    *  Socket anlegen
    */
    if ( ( SockDescr1 = socket ( HostPtr->h_addrtype, SOCK_STREAM, 0 ) ) < 0 ) {
         perror ("socket");
        exit (1);
    }

   /*
    *  Socket an den Service binden
    */
    if ( bind ( SockDescr1, &Sock1, sizeof (Sock1) ) < 0 ) {
       perror ( "bind" );
       exit ( 1 ); 
    }

   /*
    *  Empfangsbereitschaft fuer ankommende Verbindungsaufbau-
    *  wuensche signalisieren
    */
    listen ( SockDescr1, BACKLOG );

   /*
    *  In Endlosschleife die Auftraege der Clients abwickeln
    */
    while ( 1 ) {

      AddrLength = sizeof ( Sock2 );
      if ( ( SockDescr2 = accept( SockDescr1, &Sock2, &AddrLength ) ) < 0 ) {
          perror ( "accept" );
          exit ( 1 ); 
      }

      if ( ( NrRead = read ( SockDescr2, IBuffer, BUFLEN ) ) <= 0 ) {
          close ( SockDescr2 );
      } 
      else {
         /*
          *   XDR-Stream zum Dekodieren eroeffnen 
          */
          xdrmem_create (&xdrs1, IBuffer, BUFLEN, XDR_DECODE);
         /*
          *   Dekodierung durchfuehren
          */
          if (!xdr_personal (&xdrs1, &pers1)) {
              fprintf ( stderr, "Fehlerhafte Dekodierung\n" );
          }
          else  {
             /* 
              *  XDR-Stream fuer Sendepuffer oeffnen, Daten wieder kodieren
              *  und an Client zurueckschicken 
              */

              xdrmem_create (&xdrs2, OBuffer, BUFLEN, XDR_ENCODE);

             /*
              *   Kodierung durchfuehren
              */
              if (!xdr_personal (&xdrs2, &pers1)) {
                 fprintf ( stderr, "Fehlerhafte Kodierung\n" );
              }
              else {
                  NrWrite = write ( SockDescr2, OBuffer, xdr_getpos ( &xdrs2 ) );
              }
              /*
               *  Speicher freigeben
               */
              xdr_free (xdr_personal, &pers1);
          }
      }
  
     /*
      *  XDR-Streams freigeben und Verbindung abbauen
      */ 
      xdr_destroy ( &xdrs1 );
      xdr_destroy ( &xdrs2 );
      close ( SockDescr2 );
   }  /* while */

}