2000-03-09 18:31:51 +00:00
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/* packet-mpls.c
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* Routines for MPLS data packet disassembly
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*
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* (c) Copyright Ashok Narayanan <ashokn@cisco.com>
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*
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2001-12-10 00:26:21 +00:00
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* $Id: packet-mpls.c,v 1.24 2001/12/10 00:25:30 guy Exp $
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2000-03-09 18:31:51 +00:00
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*
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* Ethereal - Network traffic analyzer
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2001-04-23 18:05:19 +00:00
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* By Gerald Combs <gerald@ethereal.com>
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2000-03-09 18:31:51 +00:00
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* Copyright 1998 Gerald Combs
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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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/*
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* NOTES
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*
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* This module defines routines to handle Ethernet-encapsulated MPLS IP packets.
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* It should implement all the functionality in <draft-ietf-mpls-label-encaps-07.txt>
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* Multicast MPLS support is not tested yet
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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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#ifdef HAVE_SYS_TYPES_H
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# include <sys/types.h>
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#endif
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#include <glib.h>
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#include "packet.h"
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2000-12-14 08:20:31 +00:00
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#include "ppptypes.h"
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2001-04-17 06:43:21 +00:00
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#include "etypes.h"
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2000-03-09 18:31:51 +00:00
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static gint proto_mpls = -1;
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static gint ett_mpls = -1;
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/* Special labels in MPLS */
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enum {
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IP4_EXPLICIT_NULL = 0,
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ROUTER_ALERT,
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IP6_EXPLICIT_NULL,
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IMPLICIT_NULL,
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MAX_RESERVED = 15
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};
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static const value_string special_labels[] = {
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{IP4_EXPLICIT_NULL, "IPv4 Explicit-Null"},
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{ROUTER_ALERT, "Router Alert"},
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{IP6_EXPLICIT_NULL, "IPv6 Explicit-Null"},
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{IMPLICIT_NULL, "Implicit-Null"},
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{0, NULL }
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};
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/* MPLS filter values */
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enum mpls_filter_keys {
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/* Is the packet MPLS-encapsulated? */
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2000-03-20 22:52:48 +00:00
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/* MPLSF_PACKET,*/
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2000-03-09 18:31:51 +00:00
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/* MPLS encap properties */
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MPLSF_LABEL,
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MPLSF_EXP,
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MPLSF_BOTTOM_OF_STACK,
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MPLSF_TTL,
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MPLSF_MAX
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};
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static int mpls_filter[MPLSF_MAX];
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static hf_register_info mplsf_info[] = {
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2000-03-20 22:52:48 +00:00
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/* {&mpls_filter[MPLSF_PACKET],
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2001-04-19 23:02:44 +00:00
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{"MPLS Label Switched Packet", "mpls", FT_UINT8, BASE_DEC, NULL, 0x0,
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2001-06-18 02:18:27 +00:00
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"", HFILL }},*/
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2000-03-09 18:31:51 +00:00
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{&mpls_filter[MPLSF_LABEL],
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2000-03-13 16:36:31 +00:00
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{"MPLS Label", "mpls.label", FT_UINT32, BASE_DEC, VALS(special_labels), 0x0,
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2001-06-18 02:18:27 +00:00
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"", HFILL }},
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2000-03-09 18:31:51 +00:00
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{&mpls_filter[MPLSF_EXP],
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2000-03-13 16:36:31 +00:00
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{"MPLS Experimental Bits", "mpls.exp", FT_UINT8, BASE_DEC, NULL, 0x0,
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2001-06-18 02:18:27 +00:00
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"", HFILL }},
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2000-03-09 18:31:51 +00:00
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{&mpls_filter[MPLSF_BOTTOM_OF_STACK],
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2000-03-13 16:36:31 +00:00
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{"MPLS Bottom Of Label Stack", "mpls.bottom", FT_UINT8, BASE_DEC, NULL, 0x0,
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2001-06-18 02:18:27 +00:00
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"", HFILL }},
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2000-03-09 18:31:51 +00:00
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{&mpls_filter[MPLSF_TTL],
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2000-03-13 16:36:31 +00:00
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{"MPLS TTL", "mpls.ttl", FT_UINT8, BASE_DEC, NULL, 0x0,
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2001-06-18 02:18:27 +00:00
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"", HFILL }},
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2000-03-09 18:31:51 +00:00
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};
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2001-11-07 20:26:38 +00:00
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static dissector_handle_t ipv4_handle;
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static dissector_handle_t ipv6_handle;
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Tvbuffify the IP, ICMP, TCP, UDP, OSI CLNP, OSI COTP, OSI CLTP, and OSI
ESIS dissectors.
Register the IP dissector and have dissectors that call it directly
(rather than through a port table) call it through a handle.
Add a routine "tvb_set_reported_length()" which a dissector can use if
it was handed a tvbuff that contains more data than is actually in its
part of the packet - for example, handing a padded Ethernet frame to IP;
the routine sets the reported length of the tvbuff (and also adjusts the
actual length, as appropriate). Then use it in IP.
Given that, "ethertype()" can determine how much of the Ethernet frame
was actually part of an IP datagram (and can do the same for other
protocols under Ethernet that use "tvb_set_reported_length()"; have it
return the actual length, and have "dissect_eth()" and "dissect_vlan()"
use that to mark trailer data in Ethernet II frames as well as in 802.3
frames.
svn path=/trunk/; revision=2658
2000-11-18 10:38:33 +00:00
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2000-03-09 18:31:51 +00:00
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/*
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2001-01-06 05:09:35 +00:00
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* Given a 4-byte MPLS label starting at offset "offset", in tvbuff "tvb",
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* decode it.
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2000-03-09 18:31:51 +00:00
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* Return the label in "label", EXP bits in "exp",
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* bottom_of_stack in "bos", and TTL in "ttl"
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*/
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2001-01-06 05:09:35 +00:00
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void decode_mpls_label(tvbuff_t *tvb, int offset,
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2000-03-09 18:31:51 +00:00
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guint32 *label, guint8 *exp,
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guint8 *bos, guint8 *ttl)
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{
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2001-01-06 05:09:35 +00:00
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guint8 octet0 = tvb_get_guint8(tvb, offset+0);
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guint8 octet1 = tvb_get_guint8(tvb, offset+1);
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guint8 octet2 = tvb_get_guint8(tvb, offset+2);
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*label = (octet0 << 12) + (octet1 << 4) + ((octet2 >> 4) & 0xff);
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*exp = (octet2 >> 1) & 0x7;
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*bos = (octet2 & 0x1);
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*ttl = tvb_get_guint8(tvb, offset+3);
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2000-03-09 18:31:51 +00:00
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}
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2000-04-16 22:59:37 +00:00
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static void
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2001-01-06 05:09:35 +00:00
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dissect_mpls(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
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2000-03-09 18:31:51 +00:00
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{
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2001-01-06 05:09:35 +00:00
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int offset = 0;
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2000-03-09 18:31:51 +00:00
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guint32 label;
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guint8 exp;
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guint8 bos;
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guint8 ttl;
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2001-11-07 20:26:38 +00:00
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guint8 ipvers;
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2000-03-09 18:31:51 +00:00
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proto_tree *mpls_tree;
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proto_item *ti;
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2001-01-06 05:09:35 +00:00
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tvbuff_t *next_tvb;
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2000-03-09 18:31:51 +00:00
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2001-12-10 00:26:21 +00:00
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if (check_col(pinfo->cinfo, COL_PROTOCOL)) {
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col_set_str(pinfo->cinfo,COL_PROTOCOL, "MPLS");
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2000-03-09 18:31:51 +00:00
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}
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2001-12-10 00:26:21 +00:00
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if (check_col(pinfo->cinfo,COL_INFO)) {
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col_add_fstr(pinfo->cinfo,COL_INFO,"MPLS Label Switched Packet");
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2000-03-09 18:31:51 +00:00
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}
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/* Start Decoding Here. */
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2001-01-06 05:09:35 +00:00
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while (tvb_reported_length_remaining(tvb, offset) > 0) {
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decode_mpls_label(tvb, offset, &label, &exp, &bos, &ttl);
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2000-03-09 18:31:51 +00:00
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if (tree) {
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2001-01-06 05:09:35 +00:00
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ti = proto_tree_add_item(tree, proto_mpls, tvb, offset, 4, FALSE);
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2000-03-09 18:31:51 +00:00
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mpls_tree = proto_item_add_subtree(ti, ett_mpls);
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if (label <= MAX_RESERVED)
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2001-01-06 05:09:35 +00:00
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proto_tree_add_uint_format(mpls_tree, mpls_filter[MPLSF_LABEL], tvb,
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offset, 3, label, "Label: %u (%s)",
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2000-03-09 18:31:51 +00:00
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label, val_to_str(label, special_labels,
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"Reserved - Unknown"));
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else
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2001-01-06 05:09:35 +00:00
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proto_tree_add_uint(mpls_tree, mpls_filter[MPLSF_LABEL], tvb,
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2000-03-13 16:36:31 +00:00
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offset, 3, label);
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2001-01-06 05:09:35 +00:00
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proto_tree_add_uint(mpls_tree,mpls_filter[MPLSF_EXP], tvb,
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2000-03-09 18:31:51 +00:00
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offset+2,1, exp);
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2001-01-06 05:09:35 +00:00
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proto_tree_add_uint(mpls_tree,mpls_filter[MPLSF_BOTTOM_OF_STACK], tvb,
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2000-03-09 18:31:51 +00:00
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offset+2,1, bos);
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2001-01-06 05:09:35 +00:00
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proto_tree_add_uint(mpls_tree,mpls_filter[MPLSF_TTL], tvb,
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2000-03-09 18:31:51 +00:00
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offset+3,1, ttl);
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}
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offset += 4;
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if (bos) break;
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}
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2001-01-06 05:09:35 +00:00
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next_tvb = tvb_new_subset(tvb, offset, -1, -1);
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2001-11-07 20:26:38 +00:00
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ipvers = (tvb_get_guint8(tvb, offset) >> 4) & 0x0F;
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if (ipvers == 6) {
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call_dissector(ipv6_handle, next_tvb, pinfo, tree);
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} else {
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call_dissector(ipv4_handle, next_tvb, pinfo, tree);
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}
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2000-03-09 18:31:51 +00:00
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}
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void
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proto_register_mpls(void)
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{
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static gint *ett[] = {
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&ett_mpls,
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};
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2001-01-03 06:56:03 +00:00
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proto_mpls = proto_register_protocol("MultiProtocol Label Switching Header",
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"MPLS", "mpls");
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2000-03-09 18:31:51 +00:00
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proto_register_field_array(proto_mpls, mplsf_info, array_length(mplsf_info));
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proto_register_subtree_array(ett, array_length(ett));
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}
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Change the sub-dissector handoff registration routines so that the
sub-dissector table is not stored in the header_field_info struct, but
in a separate namespace. Dissector tables are now registered by name
and not by field ID. For example:
udp_dissector_table = register_dissector_table("udp.port");
Because of this different namespace, dissector tables can have names
that are not field names. This is useful for ethertype, since multiple
fields are "ethertypes".
packet-ethertype.c replaces ethertype.c (the name was changed so that it
would be named in the same fashion as all the filenames passed to make-reg-dotc)
Although it registers no protocol or field, it registers one dissector table:
ethertype_dissector_table = register_dissector_table("ethertype");
All protocols that can be called because of an ethertype field now register
that fact with dissector_add() calls.
In this way, one dissector_table services all ethertype fields
(hf_eth_type, hf_llc_type, hf_null_etype, hf_vlan_etype)
Furthermore, the code allows for names of protocols to exist in the
etype_vals, yet a dissector for that protocol doesn't exist. The name
of the dissector is printed in COL_INFO. You're welcome, Richard. :-)
svn path=/trunk/; revision=1848
2000-04-13 18:18:56 +00:00
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void
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proto_reg_handoff_mpls(void)
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{
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2001-12-03 04:00:26 +00:00
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dissector_handle_t mpls_handle;
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Tvbuffify the IP, ICMP, TCP, UDP, OSI CLNP, OSI COTP, OSI CLTP, and OSI
ESIS dissectors.
Register the IP dissector and have dissectors that call it directly
(rather than through a port table) call it through a handle.
Add a routine "tvb_set_reported_length()" which a dissector can use if
it was handed a tvbuff that contains more data than is actually in its
part of the packet - for example, handing a padded Ethernet frame to IP;
the routine sets the reported length of the tvbuff (and also adjusts the
actual length, as appropriate). Then use it in IP.
Given that, "ethertype()" can determine how much of the Ethernet frame
was actually part of an IP datagram (and can do the same for other
protocols under Ethernet that use "tvb_set_reported_length()"; have it
return the actual length, and have "dissect_eth()" and "dissect_vlan()"
use that to mark trailer data in Ethernet II frames as well as in 802.3
frames.
svn path=/trunk/; revision=2658
2000-11-18 10:38:33 +00:00
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/*
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2001-11-07 20:26:38 +00:00
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* Get a handle for the IPv4 and IPv6 dissectors.
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Tvbuffify the IP, ICMP, TCP, UDP, OSI CLNP, OSI COTP, OSI CLTP, and OSI
ESIS dissectors.
Register the IP dissector and have dissectors that call it directly
(rather than through a port table) call it through a handle.
Add a routine "tvb_set_reported_length()" which a dissector can use if
it was handed a tvbuff that contains more data than is actually in its
part of the packet - for example, handing a padded Ethernet frame to IP;
the routine sets the reported length of the tvbuff (and also adjusts the
actual length, as appropriate). Then use it in IP.
Given that, "ethertype()" can determine how much of the Ethernet frame
was actually part of an IP datagram (and can do the same for other
protocols under Ethernet that use "tvb_set_reported_length()"; have it
return the actual length, and have "dissect_eth()" and "dissect_vlan()"
use that to mark trailer data in Ethernet II frames as well as in 802.3
frames.
svn path=/trunk/; revision=2658
2000-11-18 10:38:33 +00:00
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*/
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2001-11-07 20:26:38 +00:00
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ipv4_handle = find_dissector("ip");
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ipv6_handle = find_dissector("ipv6");
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2001-01-06 05:09:35 +00:00
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2001-12-03 04:00:26 +00:00
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mpls_handle = create_dissector_handle(dissect_mpls, proto_mpls);
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dissector_add("ethertype", ETHERTYPE_MPLS, mpls_handle);
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dissector_add("ppp.protocol", PPP_MPLS_UNI, mpls_handle);
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Change the sub-dissector handoff registration routines so that the
sub-dissector table is not stored in the header_field_info struct, but
in a separate namespace. Dissector tables are now registered by name
and not by field ID. For example:
udp_dissector_table = register_dissector_table("udp.port");
Because of this different namespace, dissector tables can have names
that are not field names. This is useful for ethertype, since multiple
fields are "ethertypes".
packet-ethertype.c replaces ethertype.c (the name was changed so that it
would be named in the same fashion as all the filenames passed to make-reg-dotc)
Although it registers no protocol or field, it registers one dissector table:
ethertype_dissector_table = register_dissector_table("ethertype");
All protocols that can be called because of an ethertype field now register
that fact with dissector_add() calls.
In this way, one dissector_table services all ethertype fields
(hf_eth_type, hf_llc_type, hf_null_etype, hf_vlan_etype)
Furthermore, the code allows for names of protocols to exist in the
etype_vals, yet a dissector for that protocol doesn't exist. The name
of the dissector is printed in COL_INFO. You're welcome, Richard. :-)
svn path=/trunk/; revision=1848
2000-04-13 18:18:56 +00:00
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}
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