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/* packet-rtp-events.c
*
* Routines for RFC 2833 RTP Events dissection
* Copyright 2003, Kevin A. Noll <knoll[AT]poss.com>
*
* $Id$
*
* 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
* Ref http://www.ietf.org/rfc/rfc4733.txt?number=4733
*/
/*
* This dissector tries to dissect RTP Events.
*
* Cisco NSE is now supported, additions by
* Gonzalo Salgueiro <gsalguei@cisco.com>
* Chidambaram Arunachalam <carunach@cisco.com>
* Copyright 2008, Cisco Systems, Inc.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <glib.h>
#include <epan/packet.h>
#include <epan/prefs.h>
#include "packet-rtp-events.h"
#include "packet-rtp.h"
#include <epan/tap.h>
/* rtp_event_payload_type_value is the value used globally
to set the appropriate payload type
*/
static guint rtp_event_payload_type_value = 101;
/* cisco_nse_pt_value is used globally
to set the appropriate Cisco NSE payload type value
*/
static guint cisco_nse_pt_value = 100;
/* RTP Event Fields */
static int proto_rtp_events = -1;
static int rtp_event_tap = -1;
static int hf_rtp_events_event = -1; /* one byte */
static int hf_rtp_events_end = -1; /* one bit */
static int hf_rtp_events_reserved = -1; /* one bit */
static int hf_rtp_events_volume = -1; /* six bits */
static int hf_rtp_events_duration = -1; /* sixteen bits */
/* RTP Events fields defining a subtree */
static gint ett_rtp_events = -1;
void
proto_reg_handoff_rtp_events(void);
static struct _rtp_event_info rtp_event_info;
static void
dissect_rtp_events( tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree )
{
proto_item *ti = NULL;
proto_tree *rtp_events_tree = NULL;
unsigned int offset = 0;
struct _rtp_conversation_info *p_conv_data = NULL;
guint8 rtp_evt;
guint8 octet;
col_set_str(pinfo->cinfo, COL_PROTOCOL, "RTP EVENT");
col_clear(pinfo->cinfo, COL_INFO);
/* Get event fields */
rtp_evt = tvb_get_guint8(tvb, offset );
/* get tap info */
rtp_event_info.info_rtp_evt = rtp_evt;
p_conv_data = p_get_proto_data(pinfo->fd, proto_get_id_by_filter_name("rtp"));
if (p_conv_data)
rtp_event_info.info_setup_frame_num = p_conv_data->frame_number;
else
rtp_event_info.info_setup_frame_num = 0;
if ( check_col( pinfo->cinfo, COL_INFO) )
{
col_add_fstr( pinfo->cinfo, COL_INFO,
"Payload type=RTP Event, %s",
val_to_str( rtp_evt, rtp_event_type_values, "Unknown (%u)" ));
}
ti = proto_tree_add_item( tree, proto_rtp_events, tvb, offset, -1, FALSE );
rtp_events_tree = proto_item_add_subtree( ti, ett_rtp_events );
proto_tree_add_uint ( rtp_events_tree, hf_rtp_events_event, tvb, offset, 1, rtp_evt);
offset++;
octet = tvb_get_guint8(tvb, offset);
proto_tree_add_boolean (rtp_events_tree, hf_rtp_events_end, tvb, offset, 1, octet);
proto_tree_add_boolean (rtp_events_tree, hf_rtp_events_reserved, tvb, offset, 1, octet);
proto_tree_add_uint ( rtp_events_tree, hf_rtp_events_volume, tvb, offset, 1, octet);
offset++;
/* The duration field indicates the duration of the event or segment
* being reported, in timestamp units.
*/
rtp_event_info.info_duration = tvb_get_ntohs(tvb, offset);
proto_tree_add_item ( rtp_events_tree, hf_rtp_events_duration, tvb, offset, 2, FALSE);
/* set the end info for the tap */
if (octet & 0x80)
{
rtp_event_info.info_end = TRUE;
} else
{
rtp_event_info.info_end = FALSE;
}
/* Make end-of-event packets obvious in the info column */
if ((octet & 0x80))
{
col_append_str(pinfo->cinfo, COL_INFO, " (end)");
}
tap_queue_packet(rtp_event_tap, pinfo, &rtp_event_info);
}
void
proto_register_rtp_events(void)
{
module_t *rtp_events_module;
static hf_register_info hf[] =
{
{
&hf_rtp_events_event,
{
"Event ID",
"rtpevent.event_id",
FT_UINT8,
BASE_DEC,
VALS(rtp_event_type_values),
0x0,
NULL, HFILL
}
},
{
&hf_rtp_events_end,
{
"End of Event",
"rtpevent.end_of_event",
FT_BOOLEAN,
8,
NULL,
0x80,
NULL, HFILL
}
},
{
&hf_rtp_events_reserved,
{
"Reserved",
"rtpevent.reserved",
FT_BOOLEAN,
8,
NULL,
0x40,
NULL, HFILL
}
},
{
&hf_rtp_events_volume,
{
"Volume",
"rtpevent.volume",
FT_UINT8,
BASE_DEC,
NULL,
0x3F,
NULL, HFILL
}
},
{
&hf_rtp_events_duration,
{
"Event Duration",
"rtpevent.duration",
FT_UINT16,
BASE_DEC,
NULL,
0x0,
NULL, HFILL
}
},
};
static gint *ett[] =
{
&ett_rtp_events,
};
proto_rtp_events = proto_register_protocol("RFC 2833 RTP Event", "RTP Event", "rtpevent");
proto_register_field_array(proto_rtp_events, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
/* Register preferences */
rtp_events_module = prefs_register_protocol (proto_rtp_events, proto_reg_handoff_rtp_events);
prefs_register_uint_preference (rtp_events_module,
"event_payload_type_value", "Payload Type for RFC2833 RTP Events",
"This is the value of the Payload Type field"
" that specifies RTP Events", 10,
&rtp_event_payload_type_value);
prefs_register_uint_preference (rtp_events_module,
"cisco_nse_payload_type_value", "Payload Type for Cisco Named Signaling Events",
"This is the value of the Payload Type field"
" that specifies Cisco Named Signaling Events", 10,
&cisco_nse_pt_value);
register_dissector("rtpevent", dissect_rtp_events, proto_rtp_events);
rtp_event_tap = register_tap("rtpevent");
}
void
proto_reg_handoff_rtp_events(void)
{
static dissector_handle_t rtp_events_handle;
/* saved_payload_type_value is a temporary place to save */
/* the value so we can properly reinitialize when the */
/* settings get changed. */
static guint saved_payload_type_value;
static guint saved_cisco_nse_pt_value;
static gboolean rtp_events_prefs_initialized = FALSE;
if (!rtp_events_prefs_initialized) {
rtp_events_handle = find_dissector("rtpevent");
dissector_add_string("rtp_dyn_payload_type", "telephone-event", rtp_events_handle);
dissector_add_string("rtp_dyn_payload_type", "X-NSE", rtp_events_handle);
rtp_events_prefs_initialized = TRUE;
}
else {
dissector_delete_uint("rtp.pt", saved_payload_type_value, rtp_events_handle);
dissector_delete_uint("rtp.pt", saved_cisco_nse_pt_value, rtp_events_handle);
}
saved_payload_type_value = rtp_event_payload_type_value;
/* rtp_event_payload_type_value is set from preferences */
saved_cisco_nse_pt_value = cisco_nse_pt_value;
/* cisco_nse_pt_value is set from preferences */
dissector_add_uint("rtp.pt", saved_payload_type_value, rtp_events_handle);
dissector_add_uint("rtp.pt", saved_cisco_nse_pt_value, rtp_events_handle);
}
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