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wireshark/epan/dissectors/packet-gmrp.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

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/* packet-gmrp.c
* Routines for GMRP (GARP Multicast Registration Protocol) dissection
* Copyright 2001, Markus Seehofer <mseehofe@nt.hirschmann.de>
*
* Based on the code from packet-gvrp.c (GVRP) from
* Kevin Shi <techishi@ms22.hinet.net> Copyright 2000
*
* 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>
#include <epan/llcsaps.h>
void proto_register_gmrp(void);
/* Initialize the protocol and registered fields */
static int proto_gmrp = -1;
static int hf_gmrp_proto_id = -1;
static int hf_gmrp_attribute_type = -1;
static int hf_gmrp_attribute_length = -1;
static int hf_gmrp_attribute_event = -1;
static int hf_gmrp_attribute_value_group_membership = -1;
static int hf_gmrp_attribute_value_service_requirement = -1;
static int hf_gmrp_end_of_mark = -1;
/* Initialize the subtree pointers */
static gint ett_gmrp = -1;
static gint ett_gmrp_message = -1;
static gint ett_gmrp_attribute_list = -1;
/*static gint ett_gmrp_attribute = -1;*/
static expert_field ei_gmrp_proto_id = EI_INIT;
/* Constant definitions */
#define GARP_DEFAULT_PROTOCOL_ID 0x0001
#define GARP_END_OF_MARK 0x00
#define GMRP_ATTRIBUTE_TYPE_GROUP_MEMBERSHIP 0x01
#define GMRP_ATTRIBUTE_TYPE_SERVICE_REQUIREMENT 0x02
#define GMRP_SERVICE_REQUIREMENT_FORWARD_ALL 0x00
#define GMRP_SERVICE_REQUIREMENT_FORWARD_ALL_UNREGISTERED 0x01
static const value_string attribute_type_vals[] = {
{ GMRP_ATTRIBUTE_TYPE_GROUP_MEMBERSHIP ,"Group Membership" },
{ GMRP_ATTRIBUTE_TYPE_SERVICE_REQUIREMENT ,"Service Requirement" },
{ 0, NULL }
};
/* The length of GMRP LeaveAll attribute should be 2 octets (one for length
* and the other for event) */
#define GMRP_LENGTH_LEAVEALL (int)(sizeof(guint8)+sizeof(guint8))
/* The length of GMRP attribute other than LeaveAll should be:
*
* 8 bytes for Group Membership (1 for length, 1 for event and 6 for mac address to register)
* or
* 3 bytes for Service Requirement (1 for length, 1 for event, 1 for attribute value)
*
*/
#define GMRP_GROUP_MEMBERSHIP_NON_LEAVEALL (int)(sizeof(guint8)+sizeof(guint8)+(6*sizeof(guint8)))
#define GMRP_SERVICE_REQUIREMENT_NON_LEAVEALL (int)(sizeof(guint8)+sizeof(guint8)+sizeof(guint8))
/* Packet offset definitions */
#define GARP_PROTOCOL_ID 0
/* Event definitions */
#define GMRP_EVENT_LEAVEALL 0
#define GMRP_EVENT_JOINEMPTY 1
#define GMRP_EVENT_JOININ 2
#define GMRP_EVENT_LEAVEEMPTY 3
#define GMRP_EVENT_LEAVEIN 4
#define GMRP_EVENT_EMPTY 5
static const value_string event_vals[] = {
{ GMRP_EVENT_LEAVEALL, "Leave All" },
{ GMRP_EVENT_JOINEMPTY, "Join Empty" },
{ GMRP_EVENT_JOININ, "Join In" },
{ GMRP_EVENT_LEAVEEMPTY, "Leave Empty" },
{ GMRP_EVENT_LEAVEIN, "Leave In" },
{ GMRP_EVENT_EMPTY, "Empty" },
{ 0, NULL }
};
/* Code to actually dissect the packets */
static int
dissect_gmrp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
{
proto_item *ti;
proto_tree *gmrp_tree, *msg_tree, *attr_tree;
guint16 protocol_id;
guint8 octet;
guint8 attribute_type;
int msg_index, attr_index, offset = 0, length = tvb_reported_length(tvb);
col_set_str(pinfo->cinfo, COL_PROTOCOL, "GMRP");
col_set_str(pinfo->cinfo, COL_INFO, "GMRP");
ti = proto_tree_add_item(tree, proto_gmrp, tvb, 0, -1, ENC_NA);
gmrp_tree = proto_item_add_subtree(ti, ett_gmrp);
/* Read in GARP protocol ID */
protocol_id = tvb_get_ntohs(tvb, GARP_PROTOCOL_ID);
ti = proto_tree_add_uint_format_value(gmrp_tree, hf_gmrp_proto_id, tvb,
GARP_PROTOCOL_ID, 2, protocol_id,
"0x%04x (%s)", protocol_id,
protocol_id == GARP_DEFAULT_PROTOCOL_ID ?
"GARP Multicast Registration Protocol" :
"Unknown Protocol");
/* Currently only one protocol ID is supported */
if (protocol_id != GARP_DEFAULT_PROTOCOL_ID)
{
expert_add_info(pinfo, ti, &ei_gmrp_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. */
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_uint_format(gmrp_tree, hf_gmrp_end_of_mark, tvb, offset, 1, octet, "End of pdu");
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(gmrp_tree, tvb, msg_start, -1,
ett_gmrp_message, &msg_item, "Message %d", msg_index + 1);
proto_tree_add_uint(msg_tree, hf_gmrp_attribute_type, tvb,
msg_start, 1, octet);
/* GMRP supports Group Membership and Service Requirement as attribute types */
if ( (octet != GMRP_ATTRIBUTE_TYPE_GROUP_MEMBERSHIP) && (octet != GMRP_ATTRIBUTE_TYPE_SERVICE_REQUIREMENT) )
{
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_uint_format(msg_tree, hf_gmrp_end_of_mark, tvb, offset,
1, octet, " End of mark");
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_gmrp_attribute_list, &attr_item, " Attribute %d", attr_index + 1);
proto_tree_add_uint(attr_tree, hf_gmrp_attribute_length,
tvb, attr_start, 1, octet);
/* Read in attribute event */
event = tvb_get_guint8(tvb, offset);
proto_tree_add_uint(attr_tree, hf_gmrp_attribute_event,
tvb, offset, 1, event);
offset += 1;
length -= 1;
switch (event) {
case GMRP_EVENT_LEAVEALL:
if (octet != GMRP_LENGTH_LEAVEALL)
{
call_data_dissector(tvb_new_subset_remaining(tvb, offset),
pinfo, tree);
return tvb_captured_length(tvb);
}
break;
case GMRP_EVENT_JOINEMPTY:
case GMRP_EVENT_JOININ:
case GMRP_EVENT_LEAVEEMPTY:
case GMRP_EVENT_LEAVEIN:
case GMRP_EVENT_EMPTY:
if ( (octet != GMRP_GROUP_MEMBERSHIP_NON_LEAVEALL) &&
(octet != GMRP_SERVICE_REQUIREMENT_NON_LEAVEALL) )
{
call_data_dissector(tvb_new_subset_remaining(tvb, offset),
pinfo, tree);
return tvb_captured_length(tvb);
}
/* Show attribute value */
if ( GMRP_ATTRIBUTE_TYPE_GROUP_MEMBERSHIP == attribute_type )
{
/* Group Membership */
proto_tree_add_item(attr_tree, hf_gmrp_attribute_value_group_membership,
tvb, offset, 6, ENC_NA);
offset += 6;
length -= 6;
}
else
if ( GMRP_ATTRIBUTE_TYPE_SERVICE_REQUIREMENT == attribute_type )
{
/* Service Requirement */
proto_tree_add_item(attr_tree, hf_gmrp_attribute_value_service_requirement,
tvb, offset, 1, ENC_BIG_ENDIAN);
offset += 1;
length -= 1;
}
else
{
call_data_dissector(tvb_new_subset_remaining(tvb, offset),
pinfo, tree);
return tvb_captured_length(tvb);
}
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_gmrp(void)
{
static hf_register_info hf[] = {
{ &hf_gmrp_proto_id,
{ "Protocol Identifier", "gmrp.protocol_id",
FT_UINT16, BASE_HEX, NULL, 0x0,
NULL , HFILL }
},
{ &hf_gmrp_attribute_type,
{ "Type", "gmrp.attribute_type",
FT_UINT8, BASE_HEX, VALS(attribute_type_vals), 0x0,
NULL , HFILL }
},
{ &hf_gmrp_attribute_length,
{ "Length", "gmrp.attribute_length",
FT_UINT8, BASE_DEC, NULL, 0x0,
NULL , HFILL }
},
{ &hf_gmrp_attribute_event,
{ "Event", "gmrp.attribute_event",
FT_UINT8, BASE_DEC, VALS(event_vals), 0x0,
NULL , HFILL }
},
{ &hf_gmrp_attribute_value_group_membership,
{ "Value", "gmrp.attribute_value_group_membership",
FT_ETHER, BASE_NONE, NULL, 0x0,
NULL , HFILL }
},
{ &hf_gmrp_attribute_value_service_requirement,
{ "Value", "gmrp.attribute_value_service_requirement",
FT_UINT8, BASE_HEX, NULL, 0x0,
NULL , HFILL }
},
{ &hf_gmrp_end_of_mark,
{ "End of mark", "gmrp.end_of_mark",
FT_UINT8, BASE_HEX, NULL, 0x0,
NULL , HFILL }
}
};
static gint *ett[] = {
&ett_gmrp,
&ett_gmrp_message,
&ett_gmrp_attribute_list
};
static ei_register_info ei[] = {
{ &ei_gmrp_proto_id, { "gmrp.protocol_id.not_gmrp", PI_UNDECODED, PI_WARN, "This version of Wireshark only knows about protocol id = 1", EXPFILL }},
};
expert_module_t* expert_gmrp;
/* Register the protocol name and description for GMRP */
proto_gmrp = proto_register_protocol("GARP Multicast Registration Protocol", "GMRP", "gmrp");
/* Required function calls to register the header fields and subtrees
* used by GMRP */
proto_register_field_array(proto_gmrp, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
expert_gmrp = expert_register_protocol(proto_gmrp);
expert_register_field_array(expert_gmrp, ei, array_length(ei));
register_dissector("gmrp", dissect_gmrp, proto_gmrp);
}
/*
* 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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