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/* packet-metamako.c
* Routines for dissection of Metamako trailers. Forked from
* packet-vssmonitoring.c on 20th December, 2015.
* See https://www.metamako.com for further details.
*
* Copyright VSS-Monitoring 2011
* Copyright Metamako LP 2015
*
* 20111205 - First edition by Sake Blok (sake.blok@SYN-bit.nl)
* 20151220 - Forked to become packet-metamako.c
*
* 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>
void proto_register_metamako(void);
void proto_reg_handoff_metamako(void);
static int proto_metamako = -1;
static int hf_metamako_origfcs = -1;
static int hf_metamako_time = -1;
static int hf_metamako_flags = -1;
static int hf_metamako_srcport = -1;
static int hf_metamako_srcdevice = -1;
static int hf_metamako_tdiff = -1;
static int hf_metamako_flags_orig_fcs_vld = -1;
static int hf_metamako_reserved = -1;
static gint ett_metamako = -1;
static gint ett_metamako_timestamp = -1;
static gint ett_metamako_flags = -1;
static const int * flags[] = {
&hf_metamako_flags_orig_fcs_vld,
&hf_metamako_reserved,
NULL
};
static int
dissect_metamako(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
{
proto_tree *ti, *item;
proto_tree *metamako_tree, *timestamp_tree;
guint offset = 0;
guint trailer_len;
nstime_t metamako_time, timediff;
guint8 metamako_srcport;
guint16 metamako_srcdevice;
struct tm *tmp;
/* First get the length of the trailer */
trailer_len = tvb_reported_length(tvb);
/* The Metamako trailer is made up of:
4 bytes -- original FCS
4 bytes -- seconds
4 bytes -- nanoseconds
1 byte -- flags
2 bytes -- device ID
1 byte -- port ID
4 bytes -- New (valid) FCS
*/
/* The ethernet trailer may or may not have an FCS */
if ( (trailer_len != 20) && (trailer_len != 16) )
return 0;
/* If we have less than 12 bytes captured, we can't
read the timestamp to confirm the heuristic */
if( tvb_captured_length(tvb) < 12)
return 0;
/* Further validity checks to ensure that this is a Metamako-style timestamp trailer */
metamako_time.secs = tvb_get_ntohl(tvb, offset + 4);
metamako_time.nsecs = tvb_get_ntohl(tvb, offset + 8);
nstime_delta(&timediff, &metamako_time, &pinfo->fd->abs_ts);
/* The timestamp will be based on the uptime until the TAP is completely booted,
* this takes about 60s, but use 1 hour to be sure
*/
/* Probably just null data to fill up a short frame.
* FIXME: Should be made even stricter.
*/
if (metamako_time.secs == 0)
return 0;
if (metamako_time.secs > 3600) {
/* Check whether the timestamp in the PCAP header and the timestamp trailer
* differ less than 30 days, otherwise, this might not be a timestamp trailer
* timestamp
*/
if ( metamako_time.secs > pinfo->fd->abs_ts.secs ) {
if ( metamako_time.secs - pinfo->fd->abs_ts.secs > 2592000 ) /* 30 days */
return 0;
} else {
if ( pinfo->fd->abs_ts.secs - metamako_time.secs > 2592000 ) /* 30 days */
return 0;
}
}
/* The nanoseconds field should be less than 1000000000
*/
if ( metamako_time.nsecs >= 1000000000 )
return 0;
/* All systems are go, lets dissect the trailer */
ti = proto_tree_add_item(tree, proto_metamako, tvb, 0, (trailer_len & 0xb), ENC_NA);
metamako_tree = proto_item_add_subtree(ti, ett_metamako);
/* Original FCS */
proto_tree_add_item(metamako_tree, hf_metamako_origfcs, tvb, offset, 4, ENC_BIG_ENDIAN);
offset += 4;
/* Timestamp */
item = proto_tree_add_time(metamako_tree, hf_metamako_time, tvb, offset, 8, &metamako_time);
timestamp_tree = proto_item_add_subtree(item, ett_metamako_timestamp);
tmp = localtime(&metamako_time.secs);
if (tmp)
proto_item_append_text(ti, ", Timestamp: %02d:%02d:%02d.%09ld",
tmp->tm_hour, tmp->tm_min, tmp->tm_sec,(long)metamako_time.nsecs);
else
proto_item_append_text(ti, ", Timestamp: <Not representable>");
item = proto_tree_add_time(timestamp_tree, hf_metamako_tdiff, tvb, offset, 8, &timediff);
PROTO_ITEM_SET_GENERATED(item);
offset += 8;
proto_tree_add_bitmask(metamako_tree, tvb, offset, hf_metamako_flags, ett_metamako_flags, flags, ENC_BIG_ENDIAN);
offset++;
/* Source device */
metamako_srcdevice = tvb_get_ntohs(tvb, offset);
proto_tree_add_item(metamako_tree, hf_metamako_srcdevice, tvb, offset, 2, ENC_BIG_ENDIAN);
offset += 2;
proto_item_append_text(ti, ", Source Device: %d", metamako_srcdevice);
/* Source port */
metamako_srcport = tvb_get_guint8(tvb, offset);
proto_tree_add_item(metamako_tree, hf_metamako_srcport, tvb, offset, 1, ENC_BIG_ENDIAN);
offset++;
proto_item_append_text(ti, ", Source Port: %d", metamako_srcport);
return offset;
}
void
proto_register_metamako(void)
{
static hf_register_info hf[] = {
{ &hf_metamako_origfcs, {
"Original FCS", "metamako.orig_fcs",
FT_UINT32, BASE_HEX, NULL, 0x0,
NULL, HFILL }},
{ &hf_metamako_time, {
"Time Stamp", "metamako.time",
FT_ABSOLUTE_TIME, ABSOLUTE_TIME_LOCAL, NULL, 0x0,
NULL, HFILL }},
{&hf_metamako_flags, {
"Flags", "metamako.flags",
FT_UINT8, BASE_HEX, NULL, 0x0,
NULL, HFILL}},
{&hf_metamako_flags_orig_fcs_vld, {
"Original FCS Valid", "metamako.flags.orig_fcs_vld",
FT_BOOLEAN, 8, TFS(&tfs_valid_invalid), 0x01,
NULL, HFILL}},
{&hf_metamako_reserved, {
"Reserved", "metamako.reserved",
FT_UINT8, BASE_HEX, NULL, 0xFE,
NULL, HFILL}},
{ &hf_metamako_srcdevice, {
"Source Device ID", "metamako.srcdevice",
FT_UINT16, BASE_DEC, NULL, 0x0,
NULL, HFILL }},
{ &hf_metamako_srcport, {
"Source Port", "metamako.srcport",
FT_UINT16, BASE_DEC, NULL, 0x0,
NULL, HFILL }},
{ &hf_metamako_tdiff, {
"Time Difference", "metamako.tdiff",
FT_RELATIVE_TIME, BASE_NONE, NULL, 0x0,
"Difference from capture timestamp", HFILL }}
};
static gint *ett[] = {
&ett_metamako,
&ett_metamako_timestamp,
&ett_metamako_flags
};
proto_metamako = proto_register_protocol("Metamako ethernet trailer", "Metamako", "metamako");
proto_register_field_array(proto_metamako, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
}
void
proto_reg_handoff_metamako(void)
{
heur_dissector_add("eth.trailer", dissect_metamako, "Metamako ethernet trailer", "metamako_eth", proto_metamako, HEURISTIC_ENABLE);
}
/*
* Editor modelines - http://www.wireshark.org/tools/modelines.html
*
* Local Variables:
* c-basic-offset: 2
* tab-width: 8
* indent-tabs-mode: nil
* End:
*
* ex: set shiftwidth=2 tabstop=8 expandtab:
* :indentSize=2:tabSize=8:noTabs=true:
*/
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