Wireshark · Ethereal-dev: [Ethereal-dev] dissector for FrameRelay

[Paul Ionescu <paul@xxxxxxxx>]

Hello,

I have attached to this email a initial dissector for frame relay.
It is not complete because it is in an early stage.

Unfortunately I have no capture of frame relay to probe the dissector.
I had to "probe" the dissector by temporary binding it to some tcp port
and put in some data in that stream with "nc"
I don't know if right now is possible to capture some frame-relay
packets in linux with tcpdump.

If anybody has a capture of frame relay please send me one.

For this to work, there must be added in wiretap/wtap.h a line
containing

#define WTAP_ENCAP_FR		whatever is the last number available (maybe 20
for now)

and modified the Makefile.am and .nmake to include packet-fr.c and
packet-fr.h

/* packet-fr.c
 * Routines for Frame Relay  dissection
 *
 * Copyright 2001, Paul Ionescu	<paul@xxxxxxxx>
 *
 * $Id: packet-fr.c,v 1.0 2001/01/06 08:54:09 guy Exp $
 *
 * Ethereal - Network traffic analyzer
 * By Gerald Combs <gerald@xxxxxxxx>
 * Copyright 1998 Gerald Combs
 *
 * 
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>

#include <string.h>
#include <glib.h>
#include "packet.h"
#include "packet-ip.h"
#include "packet-ipx.h"
#include "packet-arp.h"


static gint proto_fr    = -1;
static gint ett_fr      = -1;
static gint hf_fr_dlci  = -1;
static gint hf_fr_cr	= -1;
static gint hf_fr_becn  = -1;
static gint hf_fr_fecn  = -1;
static gint hf_fr_de    = -1;
static gint hf_fr_proto = -1;

void dissect_fr(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
  proto_item *ti;
  proto_tree *fr_tree;
  guint16 fr_header,fr_proto;
  tvbuff_t   *next_tvb; 
    
  CHECK_DISPLAY_AS_DATA(proto_fr, tvb, pinfo, tree);

  pinfo->current_proto = "Frame Relay";
  if (check_col(pinfo->fd, COL_PROTOCOL)) 
      col_set_str(pinfo->fd, COL_PROTOCOL, "FR");


  if (tree) {
	
      fr_header = tvb_get_ntohs( tvb, 0 );
      fr_proto  = tvb_get_ntohs( tvb, 2 );
  
      ti = proto_tree_add_protocol_format(tree, proto_fr, tvb, 0, 4, "Frame Relay");
      fr_tree = proto_item_add_subtree(ti, ett_fr);
     
      proto_tree_add_text(fr_tree,tvb,0,2,"The real DLCI is %d",((fr_header&0x00FF)>>4)+((fr_header&0xFC00)>>6));
      proto_tree_add_uint(fr_tree, hf_fr_dlci, tvb, 0, 2, fr_header);
      proto_tree_add_boolean(fr_tree, hf_fr_cr,   tvb, 0, 1, fr_header);
      proto_tree_add_boolean(fr_tree, hf_fr_fecn, tvb, 1, 1, fr_header);
      proto_tree_add_boolean(fr_tree, hf_fr_becn, tvb, 1, 1, fr_header);
      proto_tree_add_boolean(fr_tree, hf_fr_de,   tvb, 1, 1, fr_header);
      proto_tree_add_uint(fr_tree, hf_fr_proto,tvb, 2, 2, fr_proto );

      next_tvb =  tvb_new_subset(tvb,4, -1 , -1);

      switch (fr_proto){
/*        case 0x0703:
		dissect_lmi(next_tvb,pinfo,tree);
		break;
	this is not yet implemented
*/
      	case 0x0800:
      		dissect_ip(next_tvb,pinfo,tree);
      		break;
      	case 0x8137:
	        dissect_ipx(next_tvb,pinfo,tree);
	        break;
     	default:
		dissect_data(next_tvb,0,pinfo,tree);
		break;	                                
	}

  }
  return;
}
 
/* Register the protocol with Ethereal */
void proto_register_fr(void)
{                 
  static hf_register_info hf[] = {
        { &hf_fr_dlci, { 
           "DLCI", "fr.dlci", FT_UINT16, BASE_DEC, 
            NULL, 0xFCF0, "Data-Link Connection Identifier" }},
        { &hf_fr_cr, { 
           " CR ", "fr.cr", FT_BOOLEAN, 16, 
            NULL, 0x0200, "Command/Response" }},
        { &hf_fr_fecn, { 
           "FECN", "fr.fecn", FT_BOOLEAN, 16, 
            NULL, 0x0008, "Forward Explicit Congestion Notification" }},
        { &hf_fr_becn, { 
           "BECN", "fr.becn", FT_BOOLEAN, 16, 
            NULL, 0x0004, "Backward Explicit Congestion Notification" }},
        { &hf_fr_de, { 
           " DE ", "fr.de", FT_BOOLEAN, 16, 
            NULL, 0x0002, "Discard Eligibility" }},
        { &hf_fr_proto, { 
           "Encapsulated Protocol", "fr.proto", FT_UINT16, BASE_HEX, 
            NULL, 0x0, "FrameRelay Encapsulated Protocol" }},
  };


  /* Setup protocol subtree array */
  static gint *ett[] = {
    &ett_fr,
  };

  proto_fr = proto_register_protocol("Frame Relay", "FR", "fr");
  proto_register_field_array(proto_fr, hf, array_length(hf));
  proto_register_subtree_array(ett, array_length(ett));
};

void
proto_reg_handoff_fr(void)
{
        dissector_add("wtap_encap", WTAP_ENCAP_FR, dissect_fr);
}

/* packet-fr.h
 *
 * $Id: packet-fr.h,v 1.0 2000/08/11 13:34:08 deniel Exp $
 *
 * Ethereal - Network traffic analyzer
 * By Gerald Combs <gerald@xxxxxxxx>
 * Copyright 1998 Gerald Combs
 *
 * 
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

#ifndef __PACKET_FR_H__
#define __PACKET_FR_H__

void dissect_fr(tvbuff_t *, packet_info *, proto_tree *);

#endif