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/* packet-llt.c
* Routines for Veritas Low Latency Transport (LLT) dissection
* Copyright 2006, Stephen Fisher (see AUTHORS file)
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
#include "config.h"
#include <epan/packet.h>
#include <epan/prefs.h>
#include <epan/etypes.h>
void proto_register_llt(void);
void proto_reg_handoff_llt(void);
static dissector_handle_t llt_handle;
static const value_string message_type_vs[] = {
{ 0x0a, "heartbeat" },
{ 0, NULL}
};
/* Variables for our preferences */
static unsigned preference_alternate_ethertype = 0x0;
/* Initialize the protocol and registered fields */
static int proto_llt;
static int hf_llt_cluster_num;
static int hf_llt_node_id;
static int hf_llt_message_type;
static int hf_llt_sequence_num;
static int hf_llt_message_time;
static int hf_llt_dst_node_id;
static int hf_llt_src_node_id;
/* Initialize the subtree pointers */
static int ett_llt;
/* Code to actually dissect the packets */
static int
dissect_llt(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 *llt_tree;
uint8_t message_type;
uint16_t magic;
/* Make entries in Protocol column and Info column on summary display */
col_set_str(pinfo->cinfo, COL_PROTOCOL, "LLT");
magic = tvb_get_uint16(tvb, 0, ENC_BIG_ENDIAN);
if(magic == 0x0602){ /* v2 ? */
ti = proto_tree_add_item(tree, proto_llt, tvb, 0, -1, ENC_NA);
llt_tree = proto_item_add_subtree(ti, ett_llt);
proto_tree_add_item(llt_tree, hf_llt_cluster_num, tvb, 2, 2, ENC_LITTLE_ENDIAN);
proto_tree_add_item(llt_tree, hf_llt_dst_node_id, tvb, 6, 1, ENC_LITTLE_ENDIAN);
proto_tree_add_item(llt_tree, hf_llt_src_node_id, tvb, 8, 1, ENC_LITTLE_ENDIAN);
} else {
message_type = tvb_get_uint8(tvb, 3);
col_add_fstr(pinfo->cinfo, COL_INFO, "Message type: %s", val_to_str(message_type, message_type_vs, "Unknown (0x%02x)"));
ti = proto_tree_add_item(tree, proto_llt, tvb, 0, -1, ENC_NA);
llt_tree = proto_item_add_subtree(ti, ett_llt);
proto_tree_add_item(llt_tree, hf_llt_cluster_num, tvb, 2, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(llt_tree, hf_llt_message_type, tvb, 3, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(llt_tree, hf_llt_node_id, tvb, 7, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(llt_tree, hf_llt_sequence_num, tvb, 24, 4, ENC_BIG_ENDIAN);
proto_tree_add_item(llt_tree, hf_llt_message_time, tvb, 40, 4, ENC_BIG_ENDIAN);
}
return tvb_captured_length(tvb);
}
/* Register the protocol with Wireshark */
void
proto_register_llt(void)
{
module_t *llt_module;
static hf_register_info hf[] = {
{ &hf_llt_cluster_num, { "Cluster number", "llt.cluster_num",
FT_UINT16, BASE_DEC, NULL, 0,
"Cluster number that this node belongs to", HFILL } },
{ &hf_llt_message_type, { "Message type", "llt.message_type",
FT_UINT8, BASE_HEX, VALS(message_type_vs), 0,
"Type of LLT message contained in this frame", HFILL } },
{ &hf_llt_node_id, { "Node ID", "llt.node_id",
FT_UINT8, BASE_DEC, NULL, 0,
"Number identifying this node within the cluster", HFILL } },
{ &hf_llt_sequence_num, { "Sequence number", "llt.sequence_num",
FT_UINT32, BASE_DEC, NULL, 0,
"Sequence number of this frame", HFILL } },
{ &hf_llt_message_time, { "Message time", "llt.message_time",
FT_UINT32, BASE_DEC, NULL, 0,
"Number of ticks since this node was last rebooted", HFILL } },
{ &hf_llt_dst_node_id, { "Destination Node ID", "llt.dst.node_id",
FT_UINT8, BASE_DEC, NULL, 0,
"Number identifying destination node within the cluster", HFILL } },
{ &hf_llt_src_node_id, { "Source Node ID", "llt.src.node_id",
FT_UINT8, BASE_DEC, NULL, 0,
"Number identifying source node within the cluster", HFILL } },
};
/* Setup protocol subtree array */
static int *ett[] = {
&ett_llt,
};
/* Register the protocol name and description */
proto_llt = proto_register_protocol("Veritas Low Latency Transport (LLT)", "LLT", "llt");
/* Required function calls to register the header fields and subtrees used */
proto_register_field_array(proto_llt, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
/* Register preferences module */
llt_module = prefs_register_protocol(proto_llt, proto_reg_handoff_llt);
/* Register our preferences */
prefs_register_uint_preference(llt_module, "alternate_ethertype", "Alternate ethertype value (in hex)",
"Dissect this ethertype as LLT traffic in addition to the default, 0xCAFE.",
16, &preference_alternate_ethertype); /* A base-16 (hexadecimal) value */
/* Register our dissector */
llt_handle = register_dissector("llt", dissect_llt, proto_llt);
}
void
proto_reg_handoff_llt(void)
{
static bool initialized = false;
static unsigned preference_alternate_ethertype_last;
if (!initialized) {
dissector_add_uint("ethertype", ETHERTYPE_LLT, llt_handle);
initialized = true;
} else {
if (preference_alternate_ethertype_last != 0x0) {
dissector_delete_uint("ethertype", preference_alternate_ethertype_last, llt_handle);
}
}
/* Save the setting to see if it has changed later */
preference_alternate_ethertype_last = preference_alternate_ethertype;
if (preference_alternate_ethertype != 0x0) {
/* Register the new ethertype setting */
dissector_add_uint("ethertype", preference_alternate_ethertype, llt_handle);
}
}
/*
* Editor modelines - https://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:
*/
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