2001-01-07 22:08:31 +00:00
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/* packet-fr.c
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* Routines for Frame Relay dissection
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*
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* Copyright 2001, Paul Ionescu <paul@acorp.ro>
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*
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2001-01-13 07:47:49 +00:00
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* $Id: packet-fr.c,v 1.7 2001/01/13 07:47:48 guy Exp $
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2001-01-07 22:08:31 +00:00
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*
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* Ethereal - Network traffic analyzer
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* By Gerald Combs <gerald@zing.org>
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* Copyright 1998 Gerald Combs
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*
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*/
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#ifdef HAVE_CONFIG_H
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# include "config.h"
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#endif
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#include <stdio.h>
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#include <stdlib.h>
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#include <ctype.h>
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#include <string.h>
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#include <glib.h>
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#include "packet.h"
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2001-01-10 09:07:35 +00:00
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#include "packet-llc.h"
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#include "xdlc.h"
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#include "oui.h"
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#include "nlpid.h"
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2001-01-13 07:47:49 +00:00
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#include "greproto.h"
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2001-01-07 22:08:31 +00:00
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static gint proto_fr = -1;
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static gint ett_fr = -1;
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static gint hf_fr_dlci = -1;
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static gint hf_fr_cr = -1;
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static gint hf_fr_becn = -1;
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static gint hf_fr_fecn = -1;
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static gint hf_fr_de = -1;
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2001-01-10 09:07:35 +00:00
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static gint hf_fr_nlpid = -1;
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static gint hf_fr_oui = -1;
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static gint hf_fr_pid = -1;
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static gint hf_fr_type = -1;
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static dissector_table_t fr_subdissector_table;
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static dissector_table_t fr_cisco_subdissector_table;
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2001-01-07 22:08:31 +00:00
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2001-01-10 09:07:35 +00:00
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static void dissect_lapf(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree);
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static void dissect_fr_xid(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree);
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/* see RFC2427 / RFC1490 and Cisco encapsulation */
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2001-01-09 09:59:28 +00:00
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2001-01-07 22:08:31 +00:00
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static void dissect_fr(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
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{
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proto_item *ti;
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2001-01-10 09:07:35 +00:00
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proto_tree *fr_tree = NULL;
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guint16 fr_header,fr_type,offset=2; /* default header length of FR is 2 bytes */
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guint8 fr_nlpid,fr_ctrl;
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2001-01-07 22:08:31 +00:00
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CHECK_DISPLAY_AS_DATA(proto_fr, tvb, pinfo, tree);
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pinfo->current_proto = "Frame Relay";
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if (check_col(pinfo->fd, COL_PROTOCOL))
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col_set_str(pinfo->fd, COL_PROTOCOL, "FR");
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if (check_col(pinfo->fd, COL_INFO))
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col_clear(pinfo->fd, COL_INFO);
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fr_header = tvb_get_ntohs( tvb, 0 );
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if (check_col(pinfo->fd, COL_INFO))
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2001-01-10 09:07:35 +00:00
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col_add_fstr(pinfo->fd, COL_INFO, "DLCI %u",
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((fr_header&0x00FF)>>4)+((fr_header&0xFC00)>>6));
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2001-01-07 22:08:31 +00:00
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2001-01-10 09:07:35 +00:00
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fr_header = tvb_get_ntohs( tvb, 0 );
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fr_ctrl = tvb_get_guint8( tvb,offset);
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2001-01-07 22:08:31 +00:00
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if (tree) {
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ti = proto_tree_add_protocol_format(tree, proto_fr, tvb, 0, 4, "Frame Relay");
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fr_tree = proto_item_add_subtree(ti, ett_fr);
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proto_tree_add_text(fr_tree,tvb,0,2,"The real DLCI is %u",((fr_header&0x00FF)>>4)+((fr_header&0xFC00)>>6));
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proto_tree_add_uint(fr_tree, hf_fr_dlci, tvb, 0, 2, fr_header);
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proto_tree_add_boolean(fr_tree, hf_fr_cr, tvb, 0, 1, fr_header);
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proto_tree_add_boolean(fr_tree, hf_fr_fecn, tvb, 1, 1, fr_header);
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proto_tree_add_boolean(fr_tree, hf_fr_becn, tvb, 1, 1, fr_header);
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proto_tree_add_boolean(fr_tree, hf_fr_de, tvb, 1, 1, fr_header);
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2001-01-07 22:18:32 +00:00
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}
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2001-01-07 22:08:31 +00:00
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2001-01-10 09:07:35 +00:00
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if (fr_ctrl == XDLC_U) {
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if (tree) {
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proto_tree_add_text(fr_tree, tvb, offset, 0, "------- IETF Encapsulation -------");
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/*
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* XXX - if we're going to show this as Unnumbered
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* Information, should we just hand it to
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* "dissect_xdlc_control()"?
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*/
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proto_tree_add_text(fr_tree, tvb, offset, 1, "Unnumbered Information");
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}
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offset++;
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fr_nlpid = tvb_get_guint8 (tvb,offset);
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if (fr_nlpid == 0) {
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if (tree)
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proto_tree_add_text(fr_tree, tvb, offset, 1, "Padding");
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offset++;
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fr_nlpid=tvb_get_guint8( tvb,offset);
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}
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if (tree)
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proto_tree_add_uint(fr_tree, hf_fr_nlpid, tvb, offset, 1, fr_nlpid );
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offset++;
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if (fr_nlpid == NLPID_SNAP) {
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dissect_snap(tvb, offset, pinfo, tree, fr_tree, fr_ctrl,
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hf_fr_oui, hf_fr_type, hf_fr_pid, 0);
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return;
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}
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/*
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* XXX - we should just call "dissect_osi()" here, but
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* some of the routines "dissect_osi()" calls themselves put
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* the NLPID into the tree, and not everything registered with
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* "fr.ietf" is also registered with "osinl".
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*
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* We'd need to figure out what to do with the NLPID.
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* "dissect_osi()" is registered with the "llc.dsap" dissector
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* table, so if it were to put the NLPID into the protocol
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* tree it'd have to create its own subtree for it - not all its
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* callers can do that for it (without knowing whether they're
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* going to call it or not, and the LLC dissector doesn't).
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*
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* Currently, it hands the NLPID as part of the tvbuff to
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* the sub-dissectors it calls; if none of them need to look
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* at it, we could perhaps have it put the NLPID into the
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* tree and *not* have the subdissectors expect it - that's
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* what would have to be done for IP, for example, as IP,
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* unlike CLNP, doesn't expect an NLPID as the first byte.
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*/
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if (!dissector_try_port(fr_subdissector_table,fr_nlpid, tvb_new_subset(tvb,offset,-1,-1), pinfo, tree))
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dissect_data(tvb_new_subset(tvb,offset,-1,-1), 0, pinfo, tree);
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return;
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} else {
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if ((fr_header && 0xFCF0) == 0) {
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/* this must be some sort of lapf on DLCI 0 for SVC */
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/* because DLCI 0 is rezerved for LMI and SVC signaling encaplulated in lapf */
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/* and LMI is transmitted in unnumbered information (03) */
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/* so this must be lapf (guessing) */
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dissect_lapf(tvb_new_subset(tvb,offset,-1,-1),pinfo,tree);
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return;
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}
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if (fr_ctrl == (XDLC_U|XDLC_XID)) {
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dissect_fr_xid(tvb_new_subset(tvb,offset,-1,-1),pinfo,tree);
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return;
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}
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/*
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* If the data does not start with unnumbered information (03) and
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* the DLCI# is not 0, then there may be Cisco Frame Relay encapsulation.
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*/
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proto_tree_add_text(fr_tree, tvb, offset, 0, "------- Cisco Encapsulation -------");
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fr_type = tvb_get_ntohs( tvb, offset);
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proto_tree_add_uint(fr_tree, hf_fr_type,tvb, offset, 2, fr_type );
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if (!dissector_try_port(fr_cisco_subdissector_table,fr_type, tvb_new_subset(tvb,offset+2,-1,-1), pinfo, tree))
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dissect_data(tvb_new_subset(tvb,offset+2,-1,-1), offset+2, pinfo, tree);
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2001-01-07 22:08:31 +00:00
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}
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2001-01-10 09:07:35 +00:00
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}
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static void dissect_lapf(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
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{
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proto_tree_add_text(tree, tvb, 0, 0, "Frame relay lapf not yet implemented");
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dissect_data(tvb_new_subset(tvb,0,-1,-1),0,pinfo,tree);
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}
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static void dissect_fr_xid(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
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{
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proto_tree_add_text(tree, tvb, 0, 0, "Frame relay xid not yet implemented");
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dissect_data(tvb_new_subset(tvb,0,-1,-1),0,pinfo,tree);
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2001-01-07 22:08:31 +00:00
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}
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/* Register the protocol with Ethereal */
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void proto_register_fr(void)
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{
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static hf_register_info hf[] = {
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{ &hf_fr_dlci, {
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"DLCI", "fr.dlci", FT_UINT16, BASE_DEC,
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NULL, 0xFCF0, "Data-Link Connection Identifier" }},
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{ &hf_fr_cr, {
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"CR", "fr.cr", FT_BOOLEAN, 16,
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NULL, 0x0200, "Command/Response" }},
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{ &hf_fr_fecn, {
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"FECN", "fr.fecn", FT_BOOLEAN, 16,
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NULL, 0x0008, "Forward Explicit Congestion Notification" }},
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{ &hf_fr_becn, {
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"BECN", "fr.becn", FT_BOOLEAN, 16,
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NULL, 0x0004, "Backward Explicit Congestion Notification" }},
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{ &hf_fr_de, {
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"DE", "fr.de", FT_BOOLEAN, 16,
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NULL, 0x0002, "Discard Eligibility" }},
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2001-01-10 09:07:35 +00:00
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{ &hf_fr_nlpid, {
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"NLPID", "fr.nlpid", FT_UINT8, BASE_HEX,
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NULL, 0x0, "FrameRelay Encapsulated Protocol NLPID" }},
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{ &hf_fr_oui, {
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"Organization Code", "fr.snap.oui", FT_UINT24, BASE_HEX,
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VALS(oui_vals), 0x0, ""}},
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{ &hf_fr_pid, {
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"Protocol ID", "fr.snap.pid", FT_UINT16, BASE_HEX,
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NULL, 0x0, ""}},
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{ &hf_fr_type, {
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"Type", "fr.type", FT_UINT16, BASE_HEX,
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NULL, 0x0, "FrameRelay SNAP Encapsulated Protocol" }},
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2001-01-07 22:08:31 +00:00
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};
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/* Setup protocol subtree array */
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static gint *ett[] = {
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&ett_fr,
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};
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proto_fr = proto_register_protocol("Frame Relay", "FR", "fr");
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proto_register_field_array(proto_fr, hf, array_length(hf));
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proto_register_subtree_array(ett, array_length(ett));
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2001-01-10 09:07:35 +00:00
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fr_subdissector_table = register_dissector_table("fr.ietf");
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fr_cisco_subdissector_table = register_dissector_table("fr.cisco");
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2001-01-13 07:47:49 +00:00
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}
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2001-01-08 22:18:22 +00:00
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void proto_reg_handoff_fr(void)
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{
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2001-01-09 06:32:10 +00:00
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dissector_add("wtap_encap", WTAP_ENCAP_FRELAY, dissect_fr, proto_fr);
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2001-01-13 07:47:49 +00:00
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dissector_add("gre.proto", GRE_FR, dissect_fr, proto_fr);
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2001-01-08 22:18:22 +00:00
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}
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