![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
212 lines
5.5 KiB
C
212 lines
5.5 KiB
C
/* packet-mpls.c
|
|
* Routines for MPLS data packet disassembly
|
|
*
|
|
* (c) Copyright Ashok Narayanan <ashokn@cisco.com>
|
|
*
|
|
* $Id: packet-mpls.c,v 1.17 2001/01/25 06:14:14 guy Exp $
|
|
*
|
|
* Ethereal - Network traffic analyzer
|
|
* By Gerald Combs <gerald@zing.org>
|
|
* 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.
|
|
*/
|
|
|
|
/*
|
|
* NOTES
|
|
*
|
|
* This module defines routines to handle Ethernet-encapsulated MPLS IP packets.
|
|
* It should implement all the functionality in <draft-ietf-mpls-label-encaps-07.txt>
|
|
* Multicast MPLS support is not tested yet
|
|
*/
|
|
|
|
|
|
#ifdef HAVE_CONFIG_H
|
|
# include "config.h"
|
|
#endif
|
|
|
|
#ifdef HAVE_SYS_TYPES_H
|
|
# include <sys/types.h>
|
|
#endif
|
|
|
|
#include <glib.h>
|
|
#include "etypes.h"
|
|
#include "packet.h"
|
|
#include "packet-ip.h"
|
|
#include "ppptypes.h"
|
|
#include "packet-ppp.h"
|
|
|
|
static gint proto_mpls = -1;
|
|
|
|
static gint ett_mpls = -1;
|
|
|
|
/* Special labels in MPLS */
|
|
enum {
|
|
IP4_EXPLICIT_NULL = 0,
|
|
ROUTER_ALERT,
|
|
IP6_EXPLICIT_NULL,
|
|
IMPLICIT_NULL,
|
|
|
|
MAX_RESERVED = 15
|
|
};
|
|
|
|
static const value_string special_labels[] = {
|
|
{IP4_EXPLICIT_NULL, "IPv4 Explicit-Null"},
|
|
{ROUTER_ALERT, "Router Alert"},
|
|
{IP6_EXPLICIT_NULL, "IPv6 Explicit-Null"},
|
|
{IMPLICIT_NULL, "Implicit-Null"},
|
|
{0, NULL }
|
|
};
|
|
|
|
/* MPLS filter values */
|
|
enum mpls_filter_keys {
|
|
|
|
/* Is the packet MPLS-encapsulated? */
|
|
/* MPLSF_PACKET,*/
|
|
|
|
/* MPLS encap properties */
|
|
MPLSF_LABEL,
|
|
MPLSF_EXP,
|
|
MPLSF_BOTTOM_OF_STACK,
|
|
MPLSF_TTL,
|
|
|
|
MPLSF_MAX
|
|
};
|
|
|
|
static int mpls_filter[MPLSF_MAX];
|
|
static hf_register_info mplsf_info[] = {
|
|
|
|
/* {&mpls_filter[MPLSF_PACKET],
|
|
{"MPLS Label Switched Packet", "mpls", FT_UINT8, BASE_NONE, NULL, 0x0,
|
|
"" }},*/
|
|
|
|
{&mpls_filter[MPLSF_LABEL],
|
|
{"MPLS Label", "mpls.label", FT_UINT32, BASE_DEC, VALS(special_labels), 0x0,
|
|
"" }},
|
|
|
|
{&mpls_filter[MPLSF_EXP],
|
|
{"MPLS Experimental Bits", "mpls.exp", FT_UINT8, BASE_DEC, NULL, 0x0,
|
|
"" }},
|
|
|
|
{&mpls_filter[MPLSF_BOTTOM_OF_STACK],
|
|
{"MPLS Bottom Of Label Stack", "mpls.bottom", FT_UINT8, BASE_DEC, NULL, 0x0,
|
|
"" }},
|
|
|
|
{&mpls_filter[MPLSF_TTL],
|
|
{"MPLS TTL", "mpls.ttl", FT_UINT8, BASE_DEC, NULL, 0x0,
|
|
"" }},
|
|
};
|
|
|
|
static dissector_handle_t ip_handle;
|
|
|
|
/*
|
|
* Given a 4-byte MPLS label starting at offset "offset", in tvbuff "tvb",
|
|
* decode it.
|
|
* Return the label in "label", EXP bits in "exp",
|
|
* bottom_of_stack in "bos", and TTL in "ttl"
|
|
*/
|
|
void decode_mpls_label(tvbuff_t *tvb, int offset,
|
|
guint32 *label, guint8 *exp,
|
|
guint8 *bos, guint8 *ttl)
|
|
{
|
|
guint8 octet0 = tvb_get_guint8(tvb, offset+0);
|
|
guint8 octet1 = tvb_get_guint8(tvb, offset+1);
|
|
guint8 octet2 = tvb_get_guint8(tvb, offset+2);
|
|
|
|
*label = (octet0 << 12) + (octet1 << 4) + ((octet2 >> 4) & 0xff);
|
|
*exp = (octet2 >> 1) & 0x7;
|
|
*bos = (octet2 & 0x1);
|
|
*ttl = tvb_get_guint8(tvb, offset+3);
|
|
}
|
|
|
|
static void
|
|
dissect_mpls(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
|
|
{
|
|
int offset = 0;
|
|
guint32 label;
|
|
guint8 exp;
|
|
guint8 bos;
|
|
guint8 ttl;
|
|
|
|
proto_tree *mpls_tree;
|
|
proto_item *ti;
|
|
tvbuff_t *next_tvb;
|
|
|
|
if (check_col(pinfo->fd, COL_PROTOCOL)) {
|
|
col_set_str(pinfo->fd,COL_PROTOCOL, "MPLS");
|
|
}
|
|
|
|
if (check_col(pinfo->fd,COL_INFO)) {
|
|
col_add_fstr(pinfo->fd,COL_INFO,"MPLS Label Switched Packet");
|
|
}
|
|
|
|
/* Start Decoding Here. */
|
|
while (tvb_reported_length_remaining(tvb, offset) > 0) {
|
|
decode_mpls_label(tvb, offset, &label, &exp, &bos, &ttl);
|
|
|
|
if (tree) {
|
|
|
|
ti = proto_tree_add_item(tree, proto_mpls, tvb, offset, 4, FALSE);
|
|
mpls_tree = proto_item_add_subtree(ti, ett_mpls);
|
|
|
|
if (label <= MAX_RESERVED)
|
|
proto_tree_add_uint_format(mpls_tree, mpls_filter[MPLSF_LABEL], tvb,
|
|
offset, 3, label, "Label: %u (%s)",
|
|
label, val_to_str(label, special_labels,
|
|
"Reserved - Unknown"));
|
|
else
|
|
proto_tree_add_uint(mpls_tree, mpls_filter[MPLSF_LABEL], tvb,
|
|
offset, 3, label);
|
|
|
|
proto_tree_add_uint(mpls_tree,mpls_filter[MPLSF_EXP], tvb,
|
|
offset+2,1, exp);
|
|
proto_tree_add_uint(mpls_tree,mpls_filter[MPLSF_BOTTOM_OF_STACK], tvb,
|
|
offset+2,1, bos);
|
|
proto_tree_add_uint(mpls_tree,mpls_filter[MPLSF_TTL], tvb,
|
|
offset+3,1, ttl);
|
|
}
|
|
offset += 4;
|
|
if (bos) break;
|
|
}
|
|
next_tvb = tvb_new_subset(tvb, offset, -1, -1);
|
|
call_dissector(ip_handle, next_tvb, pinfo, tree);
|
|
}
|
|
|
|
void
|
|
proto_register_mpls(void)
|
|
{
|
|
static gint *ett[] = {
|
|
&ett_mpls,
|
|
};
|
|
|
|
proto_mpls = proto_register_protocol("MultiProtocol Label Switching Header",
|
|
"MPLS", "mpls");
|
|
proto_register_field_array(proto_mpls, mplsf_info, array_length(mplsf_info));
|
|
proto_register_subtree_array(ett, array_length(ett));
|
|
}
|
|
|
|
void
|
|
proto_reg_handoff_mpls(void)
|
|
{
|
|
/*
|
|
* Get a handle for the IP dissector.
|
|
*/
|
|
ip_handle = find_dissector("ip");
|
|
|
|
dissector_add("ethertype", ETHERTYPE_MPLS, dissect_mpls, proto_mpls);
|
|
dissector_add("ppp.protocol", PPP_MPLS_UNI, dissect_mpls, proto_mpls);
|
|
}
|