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path: root/epan/dissectors/packet-osmux.c
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/* packet-osmux.c
 * Routines for packet dissection of OSmux voice/signalling multiplex protocol
 *
 *
 * 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 <string.h>
#include <stdio.h>

#include <epan/packet.h>
#include <epan/stats_tree.h>
#include <epan/tap.h>
#include <epan/prefs.h>
#include <epan/to_str.h>
#include <epan/strutil.h>
#include <epan/conversation.h>

void proto_register_osmux(void);
void proto_reg_handoff_osmux(void);

/*
 * FIXME: Link to OSmux docs here
 */

static const value_string osmux_ft_vals[] =
{
	{0x00, "Signalling"},
	{0x01, "AMR"},
	{0x02, "Dummy"},
	{0, NULL}
};

struct osmux_hdr {
	int ft;
	int ctr;
	int amr_f;
	int amr_q;
	int seq;
	int circuit_id;
	int amr_cmr;
	int amr_ft;
};

/* Initialize the protocol and registered fields */
static dissector_handle_t osmux_handle;
static int proto_osmux = -1;
static int osmux_tap = -1;

static int hf_osmux_ft_ctr = -1;
static int hf_osmux_ft = -1;
static int hf_osmux_ctr = -1;
static int hf_osmux_amr_f = -1;
static int hf_osmux_amr_q = -1;
static int hf_osmux_seq = -1;
static int hf_osmux_circuit_id = -1;
static int hf_osmux_amr_ft_cmr = -1;
static int hf_osmux_amr_ft = -1;
static int hf_osmux_amr_cmr = -1;

/* Initialize the subtree pointers */
static gint ett_osmux = -1;
static gint ett_osmux_ft_ctr = -1;
static gint ett_osmux_amr_ft_cmr = -1;

enum {
	SUB_RSL,
	SUB_AMR,
	SUB_DUMMY,

	SUB_MAX
};


/* Code to actually dissect the packets */
static gint
dissect_osmux(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
{
	int offset = 0;

	struct osmux_hdr *osmuxh;
	proto_item *ti;
	proto_tree *osmux_tree = NULL;
	guint8 ft_ctr, amr_ft_cmr;
	col_set_str(pinfo->cinfo, COL_PROTOCOL, "OSmux");
	col_clear(pinfo->cinfo, COL_INFO);

	osmuxh = wmem_new0(wmem_packet_scope(), struct osmux_hdr);

	ft_ctr = tvb_get_guint8(tvb, offset);

	osmuxh->ft = ft_ctr >> 5;
	osmuxh->ctr = (ft_ctr >> 2) & 0x7;
	osmuxh->amr_q = !!(ft_ctr & 0x02);
	osmuxh->amr_f = !!(ft_ctr & 0x01);

	osmuxh->seq = tvb_get_guint8(tvb, offset+1);
	osmuxh->circuit_id = tvb_get_guint8(tvb, offset+2);

	amr_ft_cmr = tvb_get_guint8(tvb, offset+3);
	osmuxh->amr_ft = (amr_ft_cmr & 0xf0) >> 4;
	osmuxh->amr_cmr = amr_ft_cmr & 0x0f;

	col_append_fstr(pinfo->cinfo, COL_INFO, "OSMux ");


	ti = proto_tree_add_protocol_format(tree, proto_osmux,
			tvb, offset, -1,
			"OSmux type %s frame",
			val_to_str(osmuxh->ft, osmux_ft_vals,
				   "unknown 0x%02x"));
	osmux_tree = proto_item_add_subtree(ti, ett_osmux);

	/* Two-byte dummy packets for firewalls */
	if (ft_ctr == 0x23 && tvb_reported_length(tvb) == 2) {
		col_append_fstr(pinfo->cinfo, COL_INFO, "Dummy frame");
		proto_tree_add_item(osmux_tree, hf_osmux_circuit_id, tvb, offset+1, 1, ENC_BIG_ENDIAN);
		return 2;
	}

	col_append_fstr(pinfo->cinfo, COL_INFO, "%s ",
	                val_to_str(osmuxh->ft, osmux_ft_vals,
	                           "unknown 0x%02x"));

	{
		static const gint *ft_ctr_fields[] = {
			&hf_osmux_ft,
			&hf_osmux_ctr,
			&hf_osmux_amr_f,
			&hf_osmux_amr_q,
			NULL
		};
		proto_tree_add_bitmask(osmux_tree, tvb, offset, hf_osmux_ft_ctr,
				ett_osmux_ft_ctr, ft_ctr_fields, ENC_BIG_ENDIAN);
		offset++;
	}
	proto_tree_add_item(osmux_tree, hf_osmux_seq, tvb, offset, 1, ENC_BIG_ENDIAN);
	offset++;
	proto_tree_add_item(osmux_tree, hf_osmux_circuit_id, tvb, offset, 1, ENC_BIG_ENDIAN);
	offset++;

	{
		static const gint *amr_ft_cmr_fields[] = {
			&hf_osmux_amr_ft,
			&hf_osmux_amr_cmr,
			NULL
		};
		proto_tree_add_bitmask(osmux_tree, tvb, offset, hf_osmux_amr_ft_cmr,
				ett_osmux_amr_ft_cmr, amr_ft_cmr_fields, ENC_BIG_ENDIAN);
		offset++;
	}

	tap_queue_packet(osmux_tap, pinfo, osmuxh);

	return offset;
}

static const gchar *st_str_pkts = "Osmux Packets";
static const gchar *st_str_pkts_by_cid = "Osmux Packets by CID";
static const gchar *st_str_pkts_by_ctr = "Osmux Packets by AMR frame count";
static const gchar *st_str_pkts_by_src = "Osmux Packets by src Addr";
static const gchar *st_str_pkts_by_dst = "Osmux Packets by dst Addr";
static const gchar *st_str_pkts_by_conn = "Osmux Packets by stream";

static int st_osmux_stats = -1;
static int st_osmux_stats_cid = -1;
static int st_osmux_stats_ctr = -1;
static int st_osmux_stats_src = -1;
static int st_osmux_stats_dst = -1;
static int st_osmux_stats_conn = -1;

extern void osmux_stats_tree_init(stats_tree *st)
{
	st_osmux_stats = stats_tree_create_node(st, st_str_pkts, 0, TRUE);
	st_osmux_stats_cid = stats_tree_create_node(st, st_str_pkts_by_cid, st_osmux_stats, TRUE);
	st_osmux_stats_ctr = stats_tree_create_node(st, st_str_pkts_by_ctr, st_osmux_stats, TRUE);
	st_osmux_stats_src = stats_tree_create_node(st, st_str_pkts_by_src, st_osmux_stats, TRUE);
	st_osmux_stats_dst = stats_tree_create_node(st, st_str_pkts_by_dst, st_osmux_stats, TRUE);
	st_osmux_stats_conn = stats_tree_create_node(st, st_str_pkts_by_conn, st_osmux_stats, TRUE);
}

extern int osmux_stats_tree_packet(stats_tree *st, packet_info *pinfo,
		epan_dissect_t *edt _U_, const void *p _U_)
{
	gchar *ip_str, *ip2_str;
	gchar temp[40];
	struct osmux_hdr *osmuxh = (struct osmux_hdr*) p;


	tick_stat_node(st, st_str_pkts, 0, FALSE);

	tick_stat_node(st, st_str_pkts_by_cid, st_osmux_stats, FALSE);
	snprintf(temp, 30, "%i", osmuxh->circuit_id);
	tick_stat_node(st, temp, st_osmux_stats_cid, TRUE);

	tick_stat_node(st, st_str_pkts_by_ctr, st_osmux_stats, FALSE);
	snprintf(temp, 30, "%i", osmuxh->ctr);
	tick_stat_node(st, temp, st_osmux_stats_ctr, TRUE);

	tick_stat_node(st, st_str_pkts_by_src, 0, FALSE);
	ip_str = address_to_str(NULL, &pinfo->src);
	tick_stat_node(st, ip_str, st_osmux_stats_src, TRUE);

	tick_stat_node(st, st_str_pkts_by_dst, 0, FALSE);
	ip2_str = address_to_str(NULL, &pinfo->dst);
	tick_stat_node(st, ip2_str, st_osmux_stats_dst, TRUE);

	tick_stat_node(st, st_str_pkts_by_conn, 0, FALSE);
	snprintf(temp, 40, "%s->%s:%i", ip_str, ip2_str, osmuxh->circuit_id);
	tick_stat_node(st, temp, st_osmux_stats_conn, TRUE);

	wmem_free(NULL, ip_str);
	wmem_free(NULL, ip2_str);

	return 1;
}

void proto_register_osmux(void)
{
	static hf_register_info hf[] = {
		{&hf_osmux_ft_ctr,
		 {"FTCTRByte", "osmux.ft_ctr",
		  FT_UINT8, BASE_DEC, NULL, 0x00,
		  "Byte with Fieldtype, Counter", HFILL}
		},
		{&hf_osmux_ft,
		 {"FieldType", "osmux.ft",
		  FT_UINT8, BASE_DEC, VALS(osmux_ft_vals), 0xe0,
		  "Type of data in packet", HFILL}
		 },
		{&hf_osmux_ctr,
		 {"CTR", "osmux.ctr",
		  FT_UINT8, BASE_HEX, NULL, 0x1c,
		  "Number of AMR packets inside", HFILL}
		 },
		{&hf_osmux_amr_q,
		 {"AMR f", "osmux.amr_f",
		  FT_UINT8, BASE_HEX, NULL, 0x02,
		  "AMR f parameter", HFILL}
		 },
		{&hf_osmux_amr_f,
		 {"AMR q", "osmux.amr_q",
		  FT_UINT8, BASE_HEX, NULL, 0x01,
		  "AMR q parameter", HFILL}
		 },
		{&hf_osmux_seq,
		 {"Seq", "osmux.seq",
		  FT_UINT8, BASE_HEX, NULL, 0x0,
		  "Sequence number", HFILL}
		 },
		{&hf_osmux_circuit_id,
		 {"Circuit ID", "osmux.circuit_id",
		  FT_UINT8, BASE_HEX, NULL, 0x0,
		  "Circuit ID", HFILL}
		 },
		{&hf_osmux_amr_ft_cmr,
		 {"FourthByte", "osmux.amr_ft_cmr",
		  FT_UINT8, BASE_DEC, NULL, 0x00,
		  "Byte with AMR params ft and cmr", HFILL}
		},
		{&hf_osmux_amr_ft,
		 {"AMR ft", "osmux.amr_ft",
		  FT_UINT8, BASE_HEX, NULL, 0xf0,
		  "AMR parameter ft", HFILL}
		 },
		{&hf_osmux_amr_cmr,
		 {"AMR cmr", "osmux.amr_cmr",
		  FT_UINT8, BASE_HEX, NULL, 0x0f,
		  "AMR parameter cmr", HFILL}
		 },
	};

	static gint *ett[] = {
		&ett_osmux,
		&ett_osmux_ft_ctr,
		&ett_osmux_amr_ft_cmr,
	};

	proto_osmux = proto_register_protocol("GSM multiplexing for AMR", "GSM OSmux", "osmux");

	proto_register_field_array(proto_osmux, hf, array_length(hf));
	proto_register_subtree_array(ett, array_length(ett));
}


void proto_reg_handoff_osmux(void)
{
	static gboolean osmux_initialized = FALSE;

	if (!osmux_initialized) {
		osmux_handle = create_dissector_handle(dissect_osmux, proto_osmux);
		 dissector_add_uint("udp.port", 1984, osmux_handle);
		osmux_initialized = TRUE;
	}
	osmux_tap = register_tap("osmux");
	stats_tree_register_plugin("osmux", "osmux", "Osmux/Pakets", 0,
		osmux_stats_tree_packet, osmux_stats_tree_init,
		NULL);
}

/*
 * 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:
 */