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wireshark/epan/dissectors/packet-wsmp.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

273 lines
8.3 KiB
C
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/* packet-wsmp.c
* Routines for WAVE Short Message dissection (WSMP)
* Copyright 2013, Savari Networks (http://www.savarinetworks.com) (email: smooney@savarinetworks.com)
* Based on packet-wsmp.c implemented by
* Arada Systems (http://www.aradasystems.com) (email: siva@aradasystems.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>
/* elemenID Types */
#define TRANSMITPW 0x04
#define CHANNUM 0x0F
#define DATARATE 0x10
#define WSMP 0x80
#define WSMP_S 0x81
#define WSMP_I 0x82
void proto_register_wsmp(void);
void proto_reg_handoff_wsmp(void);
static const value_string wsmp_elemenid_names[] = {
{ 0x80, "WSMP" },
{ 0x81, "WSMP-S" },
{ 0x82, "WSMP-I" },
{ 0, NULL }
};
/* Initialize the protocol and registered fields */
static int proto_wsmp = -1;
static int hf_wsmp_version = -1;
static int hf_wsmp_psid = -1;
static int hf_wsmp_rate = -1;
static int hf_wsmp_channel = -1;
static int hf_wsmp_txpower = -1;
static int hf_wsmp_WAVEid = -1;
static int hf_wsmp_wsmlength = -1;
static int hf_wsmp_WSMP_S_data = -1;
/* Savari function to get the length of a psid based on the number of
successive 1s in the most sig bits of the most sig octet. Taken
from libwme
*/
static int wme_getpsidlen (guint8 *psid)
{
int length = 0;
if ((psid[0] & 0xF0) == 0xF0) {
length = 255;
} else if ( (psid[0] & 0xF0) == 0xE0) {
length = 4;
} else if ( (psid[0] & 0xE0) == 0xC0) {
length = 3;
} else if ( (psid[0] & 0xC0) == 0x80) {
length = 2;
} else if ((psid[0] & 0x80) == 0x00) {
length = 1;
}
return length;
}
/* Initialize the subtree pointers */
static gint ett_wsmp = -1;
static gint ett_wsmdata = -1;
static int
dissect_wsmp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
{
/* Set up structures needed to add the protocol subtree and manage it */
proto_item *ti;
proto_tree *wsmp_tree, *wsmdata_tree;
tvbuff_t *wsmdata_tvb;
guint16 wsmlength, offset;
guint32 psidLen, psid, supLen;
guint8 elemenId, elemenLen, msb;
/* Make entries in Protocol column and Info column on summary display */
col_set_str(pinfo->cinfo, COL_PROTOCOL, "WSMP");
col_set_str(pinfo->cinfo, COL_INFO, "WAVE Short Message Protocol IEEE P1609.3");
/* create display subtree for the protocol */
ti = proto_tree_add_item(tree, proto_wsmp, tvb, 0, -1, ENC_NA);
wsmp_tree = proto_item_add_subtree(ti, ett_wsmp);
offset = 0;
proto_tree_add_item(wsmp_tree,
hf_wsmp_version, tvb, offset, 1, ENC_BIG_ENDIAN);
offset++;
psid = tvb_get_guint8(tvb, offset);
psidLen = (guint32)wme_getpsidlen((guint8*)&psid);
if (psidLen == 2)
psid = tvb_get_ntohs(tvb, offset);
else if (psidLen == 3)
psid = tvb_get_ntoh24(tvb, offset);
else if (psidLen == 4)
psid = tvb_get_ntohl(tvb, offset);
proto_tree_add_item(wsmp_tree,
hf_wsmp_psid, tvb, offset, psidLen, ENC_BIG_ENDIAN);
offset += psidLen;
/* TLV decoder that does not display the T and L elements */
elemenId = tvb_get_guint8(tvb, offset);
while ((elemenId != WSMP) && (elemenId != WSMP_S) && (elemenId != WSMP_I))
{
offset++;
if (elemenId == CHANNUM)
{
elemenLen = tvb_get_guint8(tvb, offset);
offset++;
proto_tree_add_item(wsmp_tree,
hf_wsmp_channel, tvb, offset, elemenLen, ENC_BIG_ENDIAN);
offset += elemenLen;
}
else if (elemenId == DATARATE)
{
elemenLen = tvb_get_guint8(tvb, offset);
offset++;
proto_tree_add_item(wsmp_tree,
hf_wsmp_rate, tvb, offset, elemenLen, ENC_BIG_ENDIAN);
offset += elemenLen;
}
else if (elemenId == TRANSMITPW)
{
elemenLen = tvb_get_guint8(tvb, offset);
offset++;
proto_tree_add_item(wsmp_tree,
hf_wsmp_txpower, tvb, offset, elemenLen, ENC_BIG_ENDIAN);
offset += elemenLen;
}
elemenId = tvb_get_guint8(tvb, offset);
}
proto_tree_add_item(wsmp_tree,
hf_wsmp_WAVEid, tvb, offset, 1, ENC_BIG_ENDIAN);
offset++;
wsmlength = tvb_get_letohs( tvb, offset);
proto_tree_add_item(wsmp_tree,
hf_wsmp_wsmlength, tvb, offset, 2, ENC_BIG_ENDIAN);
offset += 2;
if (elemenId == WSMP_S)
{
msb = 1;
supLen = 0;
while (msb)
{
msb = tvb_get_guint8(tvb, offset + supLen);
msb = msb & 0x80;
supLen++;
}
proto_tree_add_item(wsmp_tree,
hf_wsmp_WSMP_S_data, tvb, offset, supLen, ENC_BIG_ENDIAN);
wsmlength -= supLen;
offset += supLen;
}
wsmdata_tree = proto_tree_add_subtree(wsmp_tree, tvb, offset, wsmlength,
ett_wsmdata, NULL, "Wave Short Message");
wsmdata_tvb = tvb_new_subset(tvb, offset, -1, wsmlength);
/* TODO: Branch on the application context and display accordingly
* Default: call the data dissector
*/
if (psid == 0xbff0)
{
call_data_dissector(wsmdata_tvb, pinfo, wsmdata_tree);
}
return tvb_captured_length(tvb);
}
void
proto_register_wsmp(void)
{
static hf_register_info hf[] = {
{ &hf_wsmp_version,
{ "Version", "wsmp.version", FT_UINT8, BASE_DEC, NULL, 0x0,
NULL, HFILL }},
{ &hf_wsmp_psid,
{ "PSID", "wsmp.psid", FT_UINT32, BASE_HEX, NULL, 0x0,
NULL, HFILL }},
{ &hf_wsmp_channel,
{ "Channel", "wsmp.channel", FT_UINT8, BASE_DEC, NULL, 0x0,
NULL, HFILL }},
{ &hf_wsmp_rate,
{ "Data Rate", "wsmp.rate", FT_UINT8, BASE_DEC, NULL, 0x0,
NULL, HFILL }},
{ &hf_wsmp_txpower,
{ "Transmit Power", "wsmp.txpower", FT_UINT8, BASE_DEC, NULL, 0x0,
NULL, HFILL }},
{ &hf_wsmp_WAVEid,
{ "WAVE element id", "wsmp.WAVEid", FT_UINT8, BASE_DEC, VALS(wsmp_elemenid_names), 0x0,
NULL, HFILL }},
{ &hf_wsmp_wsmlength,
{ "WSM Length", "wsmp.wsmlength", FT_UINT16, BASE_DEC, NULL, 0x0,
NULL, HFILL }},
{ &hf_wsmp_WSMP_S_data,
{ "WAVE Supplement Data", "wsmp.supplement", FT_UINT8, BASE_HEX, NULL, 0x0,
NULL, HFILL }},
};
/* Setup protocol subtree array */
static gint *ett[] = {
&ett_wsmp,
&ett_wsmdata,
};
/* Register the protocol name and description */
proto_wsmp = proto_register_protocol("Wave Short Message Protocol(IEEE P1609.3)",
"WSMP", "wsmp");
/* Required function calls to register the header fields and subtrees used */
proto_register_field_array(proto_wsmp, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
}
void
proto_reg_handoff_wsmp(void)
{
dissector_handle_t wsmp_handle;
wsmp_handle = create_dissector_handle(dissect_wsmp, proto_wsmp);
dissector_add_uint("ethertype", ETHERTYPE_WSMP, wsmp_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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