osmith/wireshark
1
0
Fork 0
forked from osmocom/wireshark
Code Pull requests Releases Wiki Activity
wireshark/epan/dissectors/packet-tdmoe.c
Michael Mann 1e60d63c8c Create call_data_dissector() to call data dissector. 
This saves many dissectors the need to find the data dissector and store a handle to it.

There were also some that were finding it, but not using it.
For others this was the only reason for their handoff function, so it could be eliminated.

Change-Id: I5d3f951ee1daa3d30c060d21bd12bbc881a8027b
Reviewed-on: https://code.wireshark.org/review/14530
Petri-Dish: Michael Mann <mmann78@netscape.net>
Reviewed-by: Michael Mann <mmann78@netscape.net>
2016-03-20 17:38:03 +00:00

196 lines
6.1 KiB
C
Raw Blame History

/* packet-tdmoe.c
* Routines for TDM over Ethernet packet disassembly
* Copyright 2010, Haakon Nessjoen <haakon.nessjoen@gmail.com>
*
* 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/etypes.h>
#include <epan/prefs.h>
/* Bitmasks for the flags in the fourth byte of the packet */
#define TDMOE_YELLOW_ALARM_BITMASK 0x01
#define TDMOE_SIGBITS_BITMASK 0x02
void proto_reg_handoff_tdmoe(void);
void proto_register_tdmoe(void);
/* protocols and header fields */
static int proto_tdmoe = -1;
static int hf_tdmoe_subaddress = -1;
static int hf_tdmoe_samples = -1;
static int hf_tdmoe_flags = -1;
static int hf_tdmoe_yellow_alarm = -1;
static int hf_tdmoe_sig_bits_present = -1;
static int hf_tdmoe_packet_counter = -1;
static int hf_tdmoe_channels = -1;
static int hf_tdmoe_sig_bits = -1;
static gint ett_tdmoe = -1;
static gint ett_tdmoe_flags = -1;
static dissector_handle_t lapd_handle;
static gint pref_tdmoe_d_channel = 24;
static int
dissect_tdmoe(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
{
proto_item *ti;
proto_tree *tdmoe_tree;
tvbuff_t *next_client;
guint16 channels;
guint16 subaddress;
gint32 offset = 0;
static const gint *flags[] = { &hf_tdmoe_yellow_alarm, &hf_tdmoe_sig_bits_present, NULL };
int chan;
/* Check that there's enough data */
if (tvb_captured_length(tvb) < 8)
return 0;
subaddress = tvb_get_ntohs(tvb, 0);
channels = tvb_get_ntohs(tvb, 6);
col_set_str(pinfo->cinfo, COL_PROTOCOL, "TDMoE");
col_add_fstr(pinfo->cinfo, COL_INFO, "Subaddress: %d Channels: %d %s",
subaddress,
channels,
(tvb_get_guint8(tvb, 3) & TDMOE_YELLOW_ALARM_BITMASK ? "[YELLOW ALARM]" : "")
);
/* create display subtree for the protocol */
ti = proto_tree_add_item(tree, proto_tdmoe, tvb, 0, -1, ENC_NA);
tdmoe_tree = proto_item_add_subtree(ti, ett_tdmoe);
/* Subaddress */
proto_tree_add_item(tdmoe_tree, hf_tdmoe_subaddress, tvb, offset, 2, ENC_BIG_ENDIAN);
offset+=2;
/* Samples (1 byte) */
proto_tree_add_item(tdmoe_tree, hf_tdmoe_samples, tvb, offset, 1, ENC_BIG_ENDIAN);
offset++;
/* Yellow alarm & "Sig bits present" bits (1 byte) */
proto_tree_add_bitmask(tdmoe_tree, tvb, offset, hf_tdmoe_flags, ett_tdmoe_flags, flags, ENC_BIG_ENDIAN);
offset++;
/* Packet counter (2 bytes) */
proto_tree_add_item(tdmoe_tree, hf_tdmoe_packet_counter, tvb, offset, 2, ENC_BIG_ENDIAN);
offset+=2;
/* Number of channels in packet (2 bytes) */
proto_tree_add_item(tdmoe_tree, hf_tdmoe_channels, tvb, offset, 2, ENC_BIG_ENDIAN);
offset+=2;
if (tvb_get_guint8(tvb, 3) & TDMOE_SIGBITS_BITMASK) {
/* 4 sigbits per channel. Might be different on other sub-protocols? */
guint16 length = (channels >> 1) + ((channels & 0x01) ? 1 : 0);
proto_tree_add_item(tdmoe_tree, hf_tdmoe_sig_bits, tvb, offset, length, ENC_NA);
offset += length;
}
/* The rest is SAMPLES * CHANNELS bytes of channel data */
for (chan = 1; chan <= channels; chan++) {
next_client = tvb_new_subset_length(tvb, offset + ((chan - 1) * 8), 8);
if (chan == pref_tdmoe_d_channel) {
call_dissector(lapd_handle, next_client, pinfo, tree);
} else {
call_data_dissector(next_client, pinfo, tree);
}
}
return 1;
}
void
proto_register_tdmoe(void)
{
static hf_register_info hf[] = {
{ &hf_tdmoe_subaddress,
{ "Subaddress", "tdmoe.subaddress", FT_UINT8, BASE_DEC, NULL, 0x0,
NULL, HFILL }},
{ &hf_tdmoe_samples,
{ "Samples", "tdmoe.samples", FT_UINT8, BASE_DEC, NULL, 0x0,
"Samples per channel", HFILL }},
{ &hf_tdmoe_flags,
{ "Flags", "tdmoe.flags", FT_UINT8, BASE_HEX, NULL, 0x0,
NULL, HFILL }},
{ &hf_tdmoe_yellow_alarm,
{ "Yellow Alarm", "tdmoe.yellowalarm", FT_BOOLEAN, 8, NULL, TDMOE_YELLOW_ALARM_BITMASK,
NULL, HFILL }},
{ &hf_tdmoe_sig_bits_present,
{ "Sig bits present", "tdmoe.sig_bits_present", FT_BOOLEAN, 8, NULL, TDMOE_SIGBITS_BITMASK,
NULL, HFILL }},
{ &hf_tdmoe_packet_counter,
{ "Counter", "tdmoe.counter", FT_UINT16, BASE_DEC, NULL, 0x0,
"Packet number", HFILL }},
{ &hf_tdmoe_channels,
{ "Channels", "tdmoe.channels", FT_UINT16, BASE_DEC, NULL, 0x0,
NULL, HFILL }},
{ &hf_tdmoe_sig_bits,
{ "Sig bits", "tdmoe.sig_bits", FT_BYTES, BASE_NONE, NULL, 0x0,
NULL, HFILL }},
};
static gint *ett[] = {
&ett_tdmoe,
&ett_tdmoe_flags
};
module_t *tdmoe_module;
proto_tdmoe = proto_register_protocol("Digium TDMoE Protocol", "TDMoE", "tdmoe");
proto_register_field_array(proto_tdmoe, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
tdmoe_module = prefs_register_protocol(proto_tdmoe, proto_reg_handoff_tdmoe);
prefs_register_uint_preference(tdmoe_module, "d_channel",
"TDMoE D-Channel",
"The TDMoE channel that contains the D-Channel.",
10, &pref_tdmoe_d_channel);
}
void
proto_reg_handoff_tdmoe(void)
{
dissector_handle_t tdmoe_handle;
tdmoe_handle = create_dissector_handle(dissect_tdmoe, proto_tdmoe);
dissector_add_uint("ethertype", ETHERTYPE_TDMOE, tdmoe_handle);
lapd_handle = find_dissector_add_dependency("lapd-bitstream", proto_tdmoe);
}
/*
* Editor modelines - http://www.wireshark.org/tools/modelines.html
*
* Local variables:
* c-basic-offset: 8
* tab-width: 8
* indent-tabs-mode: t
* End:
*
* vi: set shiftwidth=8 tabstop=8 noexpandtab:
* :indentSize=8:tabSize=8:noTabs=false:
*/
View git blame Copy permalink