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wireshark/epan/dissectors/packet-gvrp.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

354 lines
11 KiB
C
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/* packet-gvrp.c
* Routines for GVRP (GARP VLAN Registration Protocol) dissection
* Copyright 2000, Kevin Shi <techishi@ms22.hinet.net>
*
* 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/expert.h>
void proto_register_gvrp(void);
/* Initialize the protocol and registered fields */
static int proto_gvrp = -1;
static int hf_gvrp_proto_id = -1;
static int hf_gvrp_attribute_type = -1;
static int hf_gvrp_attribute_length = -1;
static int hf_gvrp_attribute_event = -1;
static int hf_gvrp_attribute_value = -1;
static int hf_gvrp_end_of_mark = -1;
/* Initialize the subtree pointers */
static gint ett_gvrp = -1;
static gint ett_gvrp_message = -1;
static gint ett_gvrp_attribute = -1;
static expert_field ei_gvrp_proto_id = EI_INIT;
/* Constant definitions */
#define GARP_DEFAULT_PROTOCOL_ID 0x0001
#define GARP_END_OF_MARK 0x00
#define GVRP_ATTRIBUTE_TYPE 0x01
static const value_string attribute_type_vals[] = {
{ GVRP_ATTRIBUTE_TYPE, "VID" },
{ 0, NULL }
};
/* The length of GVRP LeaveAll attribute should be 2 octets (one for length
* and the other for event) */
#define GVRP_LENGTH_LEAVEALL (int)(sizeof(guint8)+sizeof(guint8))
/* The length of GVRP attribute other than LeaveAll should be 4 octets (one
* for length, one for event, and the last two for VID value).
*/
#define GVRP_LENGTH_NON_LEAVEALL (int)(sizeof(guint8)+sizeof(guint8)+sizeof(guint16))
/* Packet offset definitions */
#define GARP_PROTOCOL_ID 0
/* Event definitions */
#define GVRP_EVENT_LEAVEALL 0
#define GVRP_EVENT_JOINEMPTY 1
#define GVRP_EVENT_JOININ 2
#define GVRP_EVENT_LEAVEEMPTY 3
#define GVRP_EVENT_LEAVEIN 4
#define GVRP_EVENT_EMPTY 5
static const value_string event_vals[] = {
{ GVRP_EVENT_LEAVEALL, "Leave All" },
{ GVRP_EVENT_JOINEMPTY, "Join Empty" },
{ GVRP_EVENT_JOININ, "Join In" },
{ GVRP_EVENT_LEAVEEMPTY, "Leave Empty" },
{ GVRP_EVENT_LEAVEIN, "Leave In" },
{ GVRP_EVENT_EMPTY, "Empty" },
{ 0, NULL }
};
/* Code to actually dissect the packets */
static int
dissect_gvrp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
{
proto_item *ti, *id_item;
proto_tree *gvrp_tree, *msg_tree, *attr_tree;
guint16 protocol_id;
guint8 octet;
int msg_index;
int attr_index;
int offset = 0;
int length = tvb_reported_length(tvb);
col_set_str(pinfo->cinfo, COL_PROTOCOL, "GVRP");
col_set_str(pinfo->cinfo, COL_INFO, "GVRP");
ti = proto_tree_add_item(tree, proto_gvrp, tvb, 0, length, ENC_NA);
gvrp_tree = proto_item_add_subtree(ti, ett_gvrp);
/* Read in GARP protocol ID */
protocol_id = tvb_get_ntohs(tvb, GARP_PROTOCOL_ID);
id_item = proto_tree_add_uint_format_value(gvrp_tree, hf_gvrp_proto_id, tvb,
GARP_PROTOCOL_ID, 2,
protocol_id,
"0x%04x (%s)",
protocol_id,
protocol_id == GARP_DEFAULT_PROTOCOL_ID ?
"GARP VLAN Registration Protocol" :
"Unknown Protocol");
/* Currently only one protocol ID is supported */
if (protocol_id != GARP_DEFAULT_PROTOCOL_ID)
{
expert_add_info(pinfo, id_item, &ei_gvrp_proto_id);
call_data_dissector(tvb_new_subset_remaining(tvb, GARP_PROTOCOL_ID + 2),
pinfo, tree);
return tvb_captured_length(tvb);
}
offset += 2;
length -= 2;
msg_index = 0;
/* Begin to parse GARP messages */
while (length)
{
proto_item *msg_item;
int msg_start = offset;
/* Read in attribute type. */
octet = tvb_get_guint8(tvb, offset);
/* Check for end of mark */
if (octet == GARP_END_OF_MARK)
{
/* End of GARP PDU */
if (msg_index)
{
proto_tree_add_item(gvrp_tree, hf_gvrp_end_of_mark, tvb, offset, 1, ENC_NA);
break;
}
else
{
call_data_dissector(tvb_new_subset_remaining(tvb, offset), pinfo, tree);
return tvb_captured_length(tvb);
}
}
offset += 1;
length -= 1;
msg_tree = proto_tree_add_subtree_format(gvrp_tree, tvb, msg_start, -1, ett_gvrp_message, &msg_item,
"Message %d", msg_index + 1);
proto_tree_add_uint(msg_tree, hf_gvrp_attribute_type, tvb,
msg_start, 1, octet);
/* GVRP only supports one attribute type. */
if (octet != GVRP_ATTRIBUTE_TYPE)
{
call_data_dissector(tvb_new_subset_remaining(tvb, offset),
pinfo, tree);
return tvb_captured_length(tvb);
}
attr_index = 0;
while (length)
{
int attr_start = offset;
proto_item *attr_item;
/* Read in attribute length. */
octet = tvb_get_guint8(tvb, offset);
/* Check for end of mark */
if (octet == GARP_END_OF_MARK)
{
/* If at least one message has been already read,
* check for another end of mark.
*/
if (attr_index)
{
proto_tree_add_item(msg_tree, hf_gvrp_end_of_mark, tvb, offset, 1, ENC_NA);
offset += 1;
length -= 1;
proto_item_set_len(msg_item, offset - msg_start);
break;
}
else
{
call_data_dissector(tvb_new_subset_remaining(tvb, offset), pinfo, tree);
return tvb_captured_length(tvb);
}
}
else
{
guint8 event;
offset += 1;
length -= 1;
attr_tree = proto_tree_add_subtree_format(msg_tree, tvb, attr_start, -1,
ett_gvrp_attribute, &attr_item, "Attribute %d", attr_index + 1);
proto_tree_add_uint(attr_tree, hf_gvrp_attribute_length,
tvb, attr_start, 1, octet);
/* Read in attribute event */
event = tvb_get_guint8(tvb, offset);
proto_tree_add_uint(attr_tree, hf_gvrp_attribute_event,
tvb, offset, 1, event);
offset += 1;
length -= 1;
switch (event) {
case GVRP_EVENT_LEAVEALL:
if (octet != GVRP_LENGTH_LEAVEALL)
{
call_data_dissector(tvb_new_subset_remaining(tvb, offset), pinfo,
tree);
return tvb_captured_length(tvb);
}
break;
case GVRP_EVENT_JOINEMPTY:
case GVRP_EVENT_JOININ:
case GVRP_EVENT_LEAVEEMPTY:
case GVRP_EVENT_LEAVEIN:
case GVRP_EVENT_EMPTY:
if (octet != GVRP_LENGTH_NON_LEAVEALL)
{
call_data_dissector(tvb_new_subset_remaining(tvb, offset),pinfo,
tree);
return tvb_captured_length(tvb);
}
/* Show attribute value */
proto_tree_add_item(attr_tree, hf_gvrp_attribute_value,
tvb, offset, 2, ENC_BIG_ENDIAN);
offset += 2;
length -= 2;
break;
default:
call_data_dissector(tvb_new_subset_remaining(tvb, offset), pinfo, tree);
return tvb_captured_length(tvb);
}
}
proto_item_set_len(attr_item, offset - attr_start);
attr_index++;
}
msg_index++;
}
return tvb_captured_length(tvb);
}
/* Register the protocol with Wireshark */
void
proto_register_gvrp(void)
{
static hf_register_info hf[] = {
{ &hf_gvrp_proto_id,
{ "Protocol Identifier", "gvrp.protocol_id",
FT_UINT16, BASE_HEX, NULL, 0x0,
NULL, HFILL }
},
{ &hf_gvrp_attribute_type,
{ "Type", "gvrp.attribute_type",
FT_UINT8, BASE_HEX, VALS(attribute_type_vals), 0x0,
NULL, HFILL }
},
{ &hf_gvrp_attribute_length,
{ "Length", "gvrp.attribute_length",
FT_UINT8, BASE_DEC, NULL, 0x0,
NULL, HFILL }
},
{ &hf_gvrp_attribute_event,
{ "Event", "gvrp.attribute_event",
FT_UINT8, BASE_DEC, VALS(event_vals), 0x0,
NULL, HFILL }
},
{ &hf_gvrp_attribute_value,
{ "Value", "gvrp.attribute_value",
FT_UINT16, BASE_DEC, NULL, 0x0,
NULL, HFILL },
},
{ &hf_gvrp_end_of_mark,
{ "End of Mark", "gvrp.end_of_mark",
FT_NONE, BASE_NONE, NULL, 0x0,
NULL, HFILL },
},
};
static ei_register_info ei[] = {
{ &ei_gvrp_proto_id, { "gvrp.protocol_id.unknown", PI_PROTOCOL, PI_WARN, "Warning: this version of Wireshark only knows about protocol id = 1", EXPFILL }},
};
expert_module_t* expert_gvrp;
static gint *ett[] = {
&ett_gvrp,
&ett_gvrp_message,
&ett_gvrp_attribute,
};
/* Register the protocol name and description for GVRP */
proto_gvrp = proto_register_protocol("GARP VLAN Registration Protocol", "GVRP", "gvrp");
/* Required function calls to register the header fields and subtrees
* used by GVRP */
proto_register_field_array(proto_gvrp, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
expert_gvrp = expert_register_protocol(proto_gvrp);
expert_register_field_array(expert_gvrp, ei, array_length(ei));
register_dissector("gvrp", dissect_gvrp, proto_gvrp);
}
/*
* 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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