![Guy Harris](/assets/img/avatar_default.png)
statements. Move the setting of the Protocol column in various dissectors before anything is fetched from the packet, and also clear the Info column at that point in those and some other dissectors, so that if an exception is thrown, the columns don't reflect the previous protocol. "Tvbuffify" the Mobile IP dissector (it took old-style arguments, and then converted them into tvbuff arguments, so there wasn't much to do, other than to fix references to "fd" to refer to "pinfo->fd"). In the SCTP dissector, refer to the port type and source and destination ports through "pinfo" rather than through the global "pi", as it's a tvbuffified dissector. In the SMTP and Time Protocol dissectors, use "pinfo->match_port" rather than "TCP_PORT_SMTP" when checking whether the packet is a request or reply, just in case somebody makes a non-standard port be dissected as SMTP or Time. (Also, remove a bogus comment from the Time dissector; it was probably cut-and-pasted from the TFTP dissector.) svn path=/trunk/; revision=2938
238 lines
8.6 KiB
C
238 lines
8.6 KiB
C
/* 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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* $Id: packet-fr.c,v 1.8 2001/01/25 06:14:14 guy Exp $
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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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#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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#include "greproto.h"
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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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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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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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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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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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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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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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fr_header = tvb_get_ntohs( tvb, 0 );
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fr_ctrl = tvb_get_guint8( tvb,offset);
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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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}
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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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}
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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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}
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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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{ &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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};
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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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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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}
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void proto_reg_handoff_fr(void)
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{
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dissector_add("wtap_encap", WTAP_ENCAP_FRELAY, dissect_fr, proto_fr);
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dissector_add("gre.proto", GRE_FR, dissect_fr, proto_fr);
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}
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