wireshark/packet-dec-bpdu.c
Guy Harris 5c42850e62 Use "set_actual_length()" to set the reported length of the packet's
tvbuff, so we don't increase it past what was in the packet.

For packets with unknown BPDU types, put the value of the type into the
Info column.

svn path=/trunk/; revision=4977
2002-03-19 09:02:01 +00:00

309 lines
9.5 KiB
C

/* packet-dec-bpdu.c
* Routines for DEC BPDU (DEC Spanning Tree Protocol) disassembly
*
* $Id: packet-dec-bpdu.c,v 1.13 2002/03/19 09:02:01 guy Exp $
*
* Copyright 2001 Paul Ionescu <paul@acorp.ro>
*
* Ethereal - Network traffic analyzer
* By Gerald Combs <gerald@ethereal.com>
* 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
#ifdef HAVE_SYS_TYPES_H
# include <sys/types.h>
#endif
#ifdef HAVE_NETINET_IN_H
# include <netinet/in.h>
#endif
#include <stdio.h>
#include <string.h>
#include <glib.h>
#include <epan/packet.h>
#include <epan/resolv.h>
#include "etypes.h"
#include "ppptypes.h"
/* Offsets of fields within a BPDU */
#define BPDU_DEC_CODE 0
#define BPDU_TYPE 1
#define BPDU_VERSION 2
#define BPDU_FLAGS 3
#define BPDU_ROOT_PRI 4
#define BPDU_ROOT_MAC 6
#define BPDU_ROOT_PATH_COST 12
#define BPDU_BRIDGE_PRI 14
#define BPDU_BRIDGE_MAC 16
#define BPDU_PORT_IDENTIFIER 22
#define BPDU_MESSAGE_AGE 23
#define BPDU_HELLO_TIME 24
#define BPDU_MAX_AGE 25
#define BPDU_FORWARD_DELAY 26
#define DEC_BPDU_SIZE 27
/* Flag bits */
#define BPDU_FLAGS_SHORT_TIMERS 0x80
#define BPDU_FLAGS_TCACK 0x02
#define BPDU_FLAGS_TC 0x01
static int proto_dec_bpdu = -1;
static int hf_dec_bpdu_proto_id = -1;
static int hf_dec_bpdu_type = -1;
static int hf_dec_bpdu_version_id = -1;
static int hf_dec_bpdu_flags = -1;
static int hf_dec_bpdu_flags_short_timers = -1;
static int hf_dec_bpdu_flags_tcack = -1;
static int hf_dec_bpdu_flags_tc = -1;
static int hf_dec_bpdu_root_pri = -1;
static int hf_dec_bpdu_root_mac = -1;
static int hf_dec_bpdu_root_cost = -1;
static int hf_dec_bpdu_bridge_pri = -1;
static int hf_dec_bpdu_bridge_mac = -1;
static int hf_dec_bpdu_port_id = -1;
static int hf_dec_bpdu_msg_age = -1;
static int hf_dec_bpdu_hello_time = -1;
static int hf_dec_bpdu_max_age = -1;
static int hf_dec_bpdu_forward_delay = -1;
static gint ett_dec_bpdu = -1;
static gint ett_dec_bpdu_flags = -1;
static const value_string protocol_id_vals[] = {
{ 0xe1, "DEC Spanning Tree Protocol" },
{ 0, NULL }
};
#define BPDU_TYPE_TOPOLOGY_CHANGE 2
#define BPDU_TYPE_HELLO 25
static const value_string bpdu_type_vals[] = {
{ BPDU_TYPE_TOPOLOGY_CHANGE, "Topology Change Notification" },
{ BPDU_TYPE_HELLO, "Hello Packet" },
{ 0, NULL }
};
static const char initial_sep[] = " (";
static const char cont_sep[] = ", ";
#define APPEND_BOOLEAN_FLAG(flag, item, string) \
if(flag){ \
if(item) \
proto_item_append_text(item, string, sep); \
sep = cont_sep; \
}
static void
dissect_dec_bpdu(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
guint8 protocol_version;
guint8 bpdu_type;
guint8 flags;
proto_tree *bpdu_tree;
proto_tree *flags_tree;
proto_item *ti;
const char *sep;
if (check_col(pinfo->cinfo, COL_PROTOCOL)) {
col_set_str(pinfo->cinfo, COL_PROTOCOL, "DEC_STP");
}
if (check_col(pinfo->cinfo, COL_INFO)) {
col_clear(pinfo->cinfo, COL_INFO);
}
bpdu_type = tvb_get_guint8(tvb, BPDU_TYPE);
if (check_col(pinfo->cinfo, COL_INFO)) {
col_add_str(pinfo->cinfo, COL_INFO,
val_to_str(bpdu_type, bpdu_type_vals,
"Unknown BPDU type (%u)"));
}
set_actual_length(tvb, DEC_BPDU_SIZE);
if (tree) {
ti = proto_tree_add_item(tree, proto_dec_bpdu, tvb, 0, DEC_BPDU_SIZE,
FALSE);
bpdu_tree = proto_item_add_subtree(ti, ett_dec_bpdu);
protocol_version = tvb_get_guint8(tvb, BPDU_VERSION);
proto_tree_add_item(bpdu_tree, hf_dec_bpdu_proto_id, tvb,
BPDU_DEC_CODE, 1, FALSE);
proto_tree_add_uint(bpdu_tree, hf_dec_bpdu_type, tvb,
BPDU_TYPE, 1, bpdu_type);
proto_tree_add_item(bpdu_tree, hf_dec_bpdu_version_id, tvb,
BPDU_VERSION, 1, FALSE);
flags = tvb_get_guint8(tvb, BPDU_FLAGS);
ti = proto_tree_add_uint(bpdu_tree, hf_dec_bpdu_flags, tvb,
BPDU_FLAGS, 1, flags);
flags_tree = proto_item_add_subtree(ti, ett_dec_bpdu_flags);
sep = initial_sep;
APPEND_BOOLEAN_FLAG(flags & BPDU_FLAGS_SHORT_TIMERS, ti,
"%sUse short timers");
proto_tree_add_boolean(flags_tree, hf_dec_bpdu_flags_short_timers, tvb,
BPDU_FLAGS, 1, flags);
APPEND_BOOLEAN_FLAG(flags & BPDU_FLAGS_TCACK, ti,
"%sTopology Change Acknowledgment");
proto_tree_add_boolean(flags_tree, hf_dec_bpdu_flags_tcack, tvb,
BPDU_FLAGS, 1, flags);
APPEND_BOOLEAN_FLAG(flags & BPDU_FLAGS_TC, ti,
"%sTopology Change");
proto_tree_add_boolean(flags_tree, hf_dec_bpdu_flags_tc, tvb,
BPDU_FLAGS, 1, flags);
if (sep != initial_sep) {
/* We put something in; put in the terminating ")" */
proto_item_append_text(ti, ")");
}
proto_tree_add_item(bpdu_tree, hf_dec_bpdu_root_pri, tvb,
BPDU_ROOT_PRI, 2, FALSE);
proto_tree_add_item(bpdu_tree, hf_dec_bpdu_root_mac, tvb,
BPDU_ROOT_MAC, 6, FALSE);
proto_tree_add_item(bpdu_tree, hf_dec_bpdu_root_cost, tvb,
BPDU_ROOT_PATH_COST, 2, FALSE);
proto_tree_add_item(bpdu_tree, hf_dec_bpdu_bridge_pri, tvb,
BPDU_BRIDGE_PRI, 2, FALSE);
proto_tree_add_item(bpdu_tree, hf_dec_bpdu_bridge_mac, tvb,
BPDU_BRIDGE_MAC, 6, FALSE);
proto_tree_add_item(bpdu_tree, hf_dec_bpdu_port_id, tvb,
BPDU_PORT_IDENTIFIER, 1, FALSE);
proto_tree_add_item(bpdu_tree, hf_dec_bpdu_msg_age, tvb,
BPDU_MESSAGE_AGE, 1, FALSE);
proto_tree_add_item(bpdu_tree, hf_dec_bpdu_hello_time, tvb,
BPDU_HELLO_TIME, 1, FALSE);
proto_tree_add_item(bpdu_tree, hf_dec_bpdu_max_age, tvb,
BPDU_MAX_AGE, 1, FALSE);
proto_tree_add_item(bpdu_tree, hf_dec_bpdu_forward_delay, tvb,
BPDU_FORWARD_DELAY, 1, FALSE);
}
}
static const true_false_string yesno = {
"Yes",
"No"
};
void
proto_register_dec_bpdu(void)
{
static hf_register_info hf[] = {
{ &hf_dec_bpdu_proto_id,
{ "Protocol Identifier", "dec_stp.protocol",
FT_UINT8, BASE_HEX, VALS(&protocol_id_vals), 0x0,
"", HFILL }},
{ &hf_dec_bpdu_type,
{ "BPDU Type", "dec_stp.type",
FT_UINT8, BASE_DEC, VALS(&bpdu_type_vals), 0x0,
"", HFILL }},
{ &hf_dec_bpdu_version_id,
{ "BPDU Version", "dec_stp.version",
FT_UINT8, BASE_DEC, NULL, 0x0,
"", HFILL }},
{ &hf_dec_bpdu_flags,
{ "BPDU flags", "dec_stp.flags",
FT_UINT8, BASE_HEX, NULL, 0x0,
"", HFILL }},
{ &hf_dec_bpdu_flags_short_timers,
{ "Use short timers", "dec_stp.flags.short_timers",
FT_BOOLEAN, 8, TFS(&yesno), BPDU_FLAGS_SHORT_TIMERS,
"", HFILL }},
{ &hf_dec_bpdu_flags_tcack,
{ "Topology Change Acknowledgment", "dec_stp.flags.tcack",
FT_BOOLEAN, 8, TFS(&yesno), BPDU_FLAGS_TCACK,
"", HFILL }},
{ &hf_dec_bpdu_flags_tc,
{ "Topology Change", "dec_stp.flags.tc",
FT_BOOLEAN, 8, TFS(&yesno), BPDU_FLAGS_TC,
"", HFILL }},
{ &hf_dec_bpdu_root_pri,
{ "Root Priority", "dec_stp.root.pri",
FT_UINT16, BASE_DEC, NULL, 0x0,
"", HFILL }},
{ &hf_dec_bpdu_root_mac,
{ "Root MAC", "dec_stp.root.mac",
FT_ETHER, BASE_NONE, NULL, 0x0,
"", HFILL }},
{ &hf_dec_bpdu_root_cost,
{ "Root Path Cost", "dec_stp.root.cost",
FT_UINT16, BASE_DEC, NULL, 0x0,
"", HFILL }},
{ &hf_dec_bpdu_bridge_pri,
{ "Bridge Priority", "dec_stp.bridge.pri",
FT_UINT16, BASE_DEC, NULL, 0x0,
"", HFILL }},
{ &hf_dec_bpdu_bridge_mac,
{ "Bridge MAC", "dec_stp.bridge.mac",
FT_ETHER, BASE_NONE, NULL, 0x0,
"", HFILL }},
{ &hf_dec_bpdu_port_id,
{ "Port identifier", "dec_stp.port",
FT_UINT8, BASE_DEC, NULL, 0x0,
"", HFILL }},
{ &hf_dec_bpdu_msg_age,
{ "Message Age", "dec_stp.msg_age",
FT_UINT8, BASE_DEC, NULL, 0x0,
"", HFILL }},
{ &hf_dec_bpdu_hello_time,
{ "Hello Time", "dec_stp.hello",
FT_UINT8, BASE_DEC, NULL, 0x0,
"", HFILL }},
{ &hf_dec_bpdu_max_age,
{ "Max Age", "dec_stp.max_age",
FT_UINT8, BASE_DEC, NULL, 0x0,
"", HFILL }},
{ &hf_dec_bpdu_forward_delay,
{ "Forward Delay", "dec_stp.forward",
FT_UINT8, BASE_DEC, NULL, 0x0,
"", HFILL }},
};
static gint *ett[] = {
&ett_dec_bpdu,
&ett_dec_bpdu_flags,
};
proto_dec_bpdu = proto_register_protocol("DEC Spanning Tree Protocol",
"DEC_STP", "dec_stp");
proto_register_field_array(proto_dec_bpdu, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
}
void
proto_reg_handoff_dec_bpdu(void)
{
dissector_handle_t dec_bpdu_handle;
dec_bpdu_handle = create_dissector_handle(dissect_dec_bpdu,
proto_dec_bpdu);
dissector_add("ethertype", ETHERTYPE_DEC_LB, dec_bpdu_handle);
dissector_add("chdlctype", ETHERTYPE_DEC_LB, dec_bpdu_handle);
dissector_add("ppp.protocol", PPP_DEC_LB, dec_bpdu_handle);
}