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wireshark/epan/dissectors/packet-udld.c
Michael Mann ad6fc87d64 Add proto_tree_add_checksum. 
This is an attempt to standardize display/handling of checksum fields for all dissectors.
The main target is for dissectors that do validation, but dissectors that just report the
checksum were also included just to make them easier to find in the future.

Bug: 10620
Bug: 12058
Ping-Bug: 8859
Change-Id: Ia8abd86e42eaf8ed50de6b173409e914b17993bf
Reviewed-on: https://code.wireshark.org/review/16380
Petri-Dish: Michael Mann <mmann78@netscape.net>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Jeff Morriss <jeff.morriss.ws@gmail.com>
Reviewed-by: Michael Mann <mmann78@netscape.net>
2016-07-21 12:35:22 +00:00

322 lines
11 KiB
C
Raw Blame History

/* packet-udld.c
* Routines for the disassembly of the "UniDirectional Link Detection"
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "config.h"
#include <epan/packet.h>
#include <epan/expert.h>
/*
* See
*
* http://www.ietf.org/internet-drafts/draft-foschiano-udld-02.txt
*
* for some information on UDLD.
*/
/* Offsets in TLV structure. */
#define TLV_TYPE 0
#define TLV_LENGTH 2
void proto_register_udld(void);
void proto_reg_handoff_udld(void);
static int proto_udld = -1;
static int hf_udld_version = -1;
static int hf_udld_opcode = -1;
static int hf_udld_flags = -1;
static int hf_udld_flags_rt = -1;
static int hf_udld_flags_rsy = -1;
static int hf_udld_checksum = -1;
static int hf_udld_tlvtype = -1;
static int hf_udld_tlvlength = -1;
static int hf_udld_device_id = -1;
static int hf_udld_sent_through_interface = -1;
static int hf_udld_data = -1;
static expert_field ei_udld_tlvlength = EI_INIT;
static gint ett_udld = -1;
static gint ett_udld_flags = -1;
static gint ett_udld_tlv = -1;
#define TYPE_DEVICE_ID 0x0001
#define TYPE_PORT_ID 0x0002
#define TYPE_ECHO 0x0003
#define TYPE_MESSAGE_INTERVAL 0x0004
#define TYPE_TIMEOUT_INTERVAL 0x0005
#define TYPE_DEVICE_NAME 0x0006
#define TYPE_SEQUENCE_NUMBER 0x0007
static const value_string type_vals[] = {
{ TYPE_DEVICE_ID, "Device ID" },
{ TYPE_PORT_ID, "Port ID" },
{ TYPE_ECHO, "Echo" },
{ TYPE_MESSAGE_INTERVAL, "Message interval" },
{ TYPE_TIMEOUT_INTERVAL, "Timeout interval" },
{ TYPE_DEVICE_NAME, "Device name" },
{ TYPE_SEQUENCE_NUMBER, "Sequence number" },
{ 0, NULL }
};
#define OPCODE_RESERVED 0x00
#define OPCODE_PROBE 0x01
#define OPCODE_ECHO 0x02
#define OPCODE_FLUSH 0x03
static const value_string opcode_vals[] = {
{ OPCODE_RESERVED, "Reserved" },
{ OPCODE_PROBE, "Probe" },
{ OPCODE_ECHO, "Echo" },
{ OPCODE_FLUSH, "Flush" },
{ 0, NULL }
};
static int
dissect_udld(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
{
proto_item *ti;
proto_tree *udld_tree = NULL;
int offset = 0;
guint16 type;
guint16 length;
proto_tree *tlv_tree;
int real_length;
col_set_str(pinfo->cinfo, COL_PROTOCOL, "UDLD");
col_clear(pinfo->cinfo, COL_INFO);
if (tree) {
proto_item *flags_ti;
proto_tree *flags_tree;
ti = proto_tree_add_item(tree, proto_udld, tvb, offset, -1, ENC_NA);
udld_tree = proto_item_add_subtree(ti, ett_udld);
/* UDLD header */
proto_tree_add_item(udld_tree, hf_udld_version, tvb, offset, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(udld_tree, hf_udld_opcode, tvb, offset, 1, ENC_BIG_ENDIAN);
offset += 1;
flags_ti = proto_tree_add_item(udld_tree, hf_udld_flags, tvb, offset, 1, ENC_BIG_ENDIAN);
flags_tree = proto_item_add_subtree(flags_ti, ett_udld_flags);
proto_tree_add_item(flags_tree, hf_udld_flags_rt, tvb, offset, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(flags_tree, hf_udld_flags_rsy, tvb, offset, 1, ENC_BIG_ENDIAN);
offset += 1;
proto_tree_add_checksum(udld_tree, tvb, offset, hf_udld_checksum, -1, NULL, pinfo, 0, ENC_BIG_ENDIAN, PROTO_CHECKSUM_NO_FLAGS);
offset += 2;
} else {
offset += 4; /* The version/opcode/flags/checksum fields from above */
}
while (tvb_reported_length_remaining(tvb, offset) != 0) {
type = tvb_get_ntohs(tvb, offset + TLV_TYPE);
length = tvb_get_ntohs(tvb, offset + TLV_LENGTH);
if (length < 4) {
tlv_tree = proto_tree_add_subtree_format(udld_tree, tvb, offset, 4,
ett_udld_tlv, NULL, "TLV with invalid length %u (< 4)", length);
proto_tree_add_uint(tlv_tree, hf_udld_tlvtype, tvb,
offset + TLV_TYPE, 2, type);
ti = proto_tree_add_uint(tlv_tree, hf_udld_tlvlength, tvb,
offset + TLV_LENGTH, 2, length);
expert_add_info(pinfo, ti, &ei_udld_tlvlength);
offset += 4;
break;
}
switch (type) {
case TYPE_DEVICE_ID:
/* Device ID */
col_append_fstr(pinfo->cinfo, COL_INFO,
"Device ID: %s ",
tvb_format_stringzpad(tvb, offset + 4,
length - 4));
if (tree) {
tlv_tree = proto_tree_add_subtree_format(udld_tree, tvb, offset,
length, ett_udld_tlv, NULL, "Device ID: %s",
tvb_format_stringzpad(tvb, offset + 4, length - 4));
proto_tree_add_uint(tlv_tree, hf_udld_tlvtype, tvb,
offset + TLV_TYPE, 2, type);
proto_tree_add_uint(tlv_tree, hf_udld_tlvlength, tvb,
offset + TLV_LENGTH, 2, length);
proto_tree_add_item(tlv_tree, hf_udld_device_id, tvb, offset + 4,
length - 4, ENC_ASCII|ENC_NA);
}
offset += length;
break;
case TYPE_PORT_ID:
real_length = length;
if (tvb_get_guint8(tvb, offset + real_length) != 0x00) {
/* The length in the TLV doesn't appear to be the
length of the TLV, as the byte just past it
isn't the first byte of a 2-byte big-endian
small integer; make the length of the TLV the length
in the TLV, plus 4 bytes for the TLV type and length,
minus 1 because that's what makes one capture work. */
real_length = length + 3;
}
col_append_fstr(pinfo->cinfo, COL_INFO,
"Port ID: %s ",
tvb_format_stringzpad(tvb, offset + 4, length - 4));
if (tree) {
tlv_tree = proto_tree_add_subtree_format(udld_tree, tvb, offset,
real_length, ett_udld_tlv, NULL, "Port ID: %s",
tvb_format_text(tvb, offset + 4, real_length - 4));
proto_tree_add_uint(tlv_tree, hf_udld_tlvtype, tvb,
offset + TLV_TYPE, 2, type);
proto_tree_add_uint(tlv_tree, hf_udld_tlvlength, tvb,
offset + TLV_LENGTH, 2, length);
proto_tree_add_item(tlv_tree, hf_udld_sent_through_interface, tvb, offset + 4,
real_length - 4, ENC_ASCII|ENC_NA);
}
offset += real_length;
break;
case TYPE_ECHO:
case TYPE_MESSAGE_INTERVAL:
case TYPE_TIMEOUT_INTERVAL:
case TYPE_DEVICE_NAME:
case TYPE_SEQUENCE_NUMBER:
default:
tlv_tree = proto_tree_add_subtree_format(udld_tree, tvb, offset,
length, ett_udld_tlv, NULL, "Type: %s, length: %u",
val_to_str(type, type_vals, "Unknown (0x%04x)"),
length);
proto_tree_add_uint(tlv_tree, hf_udld_tlvtype, tvb,
offset + TLV_TYPE, 2, type);
proto_tree_add_uint(tlv_tree, hf_udld_tlvlength, tvb,
offset + TLV_LENGTH, 2, length);
if (length > 4) {
proto_tree_add_item(tlv_tree, hf_udld_data, tvb, offset + 4,
length - 4, ENC_NA);
} else {
return offset;
}
offset += length;
}
}
call_data_dissector(tvb_new_subset_remaining(tvb, offset), pinfo, udld_tree);
return tvb_captured_length(tvb);
}
void
proto_register_udld(void)
{
static hf_register_info hf[] = {
{ &hf_udld_version,
{ "Version", "udld.version", FT_UINT8, BASE_DEC, NULL, 0xE0,
NULL, HFILL }},
{ &hf_udld_opcode,
{ "Opcode", "udld.opcode", FT_UINT8, BASE_DEC, VALS(opcode_vals), 0x1F,
NULL, HFILL }},
{ &hf_udld_flags,
{ "Flags", "udld.flags", FT_UINT8, BASE_DEC, NULL, 0x0,
NULL, HFILL }},
{ &hf_udld_flags_rt,
{ "Recommended timeout", "udld.flags.rt", FT_UINT8, BASE_HEX, NULL, 0x80,
NULL, HFILL }},
{ &hf_udld_flags_rsy,
{ "ReSynch", "udld.flags.rsy", FT_UINT8, BASE_HEX, NULL, 0x40,
NULL, HFILL }},
{ &hf_udld_checksum,
{ "Checksum", "udld.checksum", FT_UINT16, BASE_HEX, NULL, 0x0,
NULL, HFILL }},
{ &hf_udld_tlvtype,
{ "Type", "udld.tlv.type", FT_UINT16, BASE_HEX, VALS(type_vals), 0x0,
NULL, HFILL }},
{ &hf_udld_tlvlength,
{ "Length", "udld.tlv.len", FT_UINT16, BASE_DEC, NULL, 0x0,
NULL, HFILL }},
{ &hf_udld_device_id,
{ "Device ID", "udld.device_id", FT_STRINGZ, BASE_NONE, NULL, 0x0,
NULL, HFILL }},
{ &hf_udld_sent_through_interface,
{ "Sent through Interface", "udld.sent_through_interface", FT_STRING, BASE_NONE, NULL, 0x0,
NULL, HFILL }},
{ &hf_udld_data,
{ "Data", "udld.data", FT_BYTES, BASE_NONE, NULL, 0x0,
NULL, HFILL }},
};
static gint *ett[] = {
&ett_udld,
&ett_udld_flags,
&ett_udld_tlv
};
static ei_register_info ei[] = {
{ &ei_udld_tlvlength, { "udld.tlv.len.invalid", PI_PROTOCOL, PI_WARN, "TLV with invalid length (< 4)", EXPFILL }},
};
expert_module_t* expert_udld;
proto_udld = proto_register_protocol("Unidirectional Link Detection",
"UDLD", "udld");
proto_register_field_array(proto_udld, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
expert_udld = expert_register_protocol(proto_udld);
expert_register_field_array(expert_udld, ei, array_length(ei));
}
void
proto_reg_handoff_udld(void)
{
dissector_handle_t udld_handle;
udld_handle = create_dissector_handle(dissect_udld, proto_udld);
dissector_add_uint("llc.cisco_pid", 0x0111, udld_handle);
dissector_add_uint("chdlc.protocol", 0x0111, udld_handle);
}
/*
* Editor modelines - http://www.wireshark.org/tools/modelines.html
*
* Local variables:
* c-basic-offset: 4
* tab-width: 8
* indent-tabs-mode: nil
* End:
*
* vi: set shiftwidth=4 tabstop=8 expandtab:
* :indentSize=4:tabSize=8:noTabs=true:
*/
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