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/* packet-pktgen.c
* Routines for "Linux pktgen" dissection
* Copyright 2006 _FF_
* Francesco Fondelli <francesco dot fondelli, gmail dot com>
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
/* FF:
* The linux packet generator is a tool to generate packets at very high speed in the kernel.
* See linux/net/core/pktgen.c and linux/Documentation/networking/pktgen.txt for more info.
*/
#include "config.h"
#include <epan/packet.h>
void proto_register_pktgen(void);
void proto_reg_handoff_pktgen(void);
/* magic num used for heuristic */
#define PKTGEN_MAGIC 0xbe9be955
/* Initialize the protocol and registered fields */
static int proto_pktgen;
/* pktgen header */
static int hf_pktgen_magic;
static int hf_pktgen_seqnum;
static int hf_pktgen_tvsec;
static int hf_pktgen_tvusec;
static int hf_pktgen_timestamp;
/* Initialize the subtree pointer */
static int ett_pktgen;
/* entry point */
static bool dissect_pktgen(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
{
proto_item *ti = NULL;
proto_item *tmp = NULL;
proto_tree *pktgen_tree = NULL;
uint32_t offset = 0;
nstime_t tstamp;
uint32_t magic;
/* check for min size */
if (tvb_reported_length(tvb) < 16) { /* Not a PKTGEN packet. */
return false;
}
/* check for magic number */
magic = tvb_get_ntohl(tvb,0);
if (magic != PKTGEN_MAGIC) {
/* Not a PKTGEN packet. */
return false;
}
/* Make entries in Protocol column and Info column on summary display */
col_set_str(pinfo->cinfo, COL_PROTOCOL, "PKTGEN");
col_add_fstr(pinfo->cinfo, COL_INFO, "Seq: %u", tvb_get_ntohl(tvb, 4));
if (tree) {
/* create display subtree for the protocol */
ti = proto_tree_add_item(tree, proto_pktgen, tvb, 0, -1, ENC_NA);
pktgen_tree = proto_item_add_subtree(ti, ett_pktgen);
/* add items to the subtree */
proto_tree_add_item(pktgen_tree, hf_pktgen_magic, tvb, offset, 4, ENC_BIG_ENDIAN);
offset += 4;
proto_tree_add_item(pktgen_tree, hf_pktgen_seqnum, tvb, offset, 4, ENC_BIG_ENDIAN);
offset += 4;
tstamp.secs = tvb_get_ntohl(tvb, offset);
tmp = proto_tree_add_item(pktgen_tree, hf_pktgen_tvsec, tvb, offset, 4, ENC_BIG_ENDIAN);
proto_item_set_generated(tmp);
offset += 4;
tstamp.nsecs = tvb_get_ntohl(tvb, offset) /* microsecond on the wire so... */ * 1000;
tmp = proto_tree_add_item(pktgen_tree, hf_pktgen_tvusec, tvb, offset, 4, ENC_BIG_ENDIAN);
proto_item_set_generated(tmp);
offset += 4;
proto_tree_add_time(pktgen_tree, hf_pktgen_timestamp, tvb, offset - 8, 8, &tstamp);
if (tvb_reported_length_remaining(tvb, offset)) /* random data */
call_data_dissector(tvb_new_subset_remaining(tvb, offset), pinfo,
pktgen_tree);
}
return true;
}
/* Register the protocol with Wireshark */
void proto_register_pktgen(void)
{
/* Setup list of header fields */
static hf_register_info hf[] = {
{ &hf_pktgen_magic,
{
"Magic number", "pktgen.magic",
FT_UINT32, BASE_HEX, NULL, 0x0,
"The pktgen magic number", HFILL
}
},
{ &hf_pktgen_seqnum,
{
"Sequence number", "pktgen.seqnum",
FT_UINT32, BASE_DEC, NULL, 0x0,
NULL, HFILL
}
},
{ &hf_pktgen_tvsec,
{
"Timestamp tvsec", "pktgen.tvsec",
FT_UINT32, BASE_DEC, NULL, 0x0,
"Timestamp tvsec part", HFILL
}
},
{ &hf_pktgen_tvusec,
{
"Timestamp tvusec", "pktgen.tvusec",
FT_UINT32, BASE_DEC, NULL, 0x0,
"Timestamp tvusec part", HFILL
}
},
{ &hf_pktgen_timestamp,
{
"Timestamp", "pktgen.timestamp",
FT_ABSOLUTE_TIME, ABSOLUTE_TIME_LOCAL, NULL, 0x0,
NULL, HFILL
}
}
};
/* Setup protocol subtree array */
static int *ett[] = {
&ett_pktgen
};
/* Register the protocol name and description */
proto_pktgen = proto_register_protocol("Linux Kernel Packet Generator", "PKTGEN", "pktgen");
/* Required function calls to register the header fields and subtrees used */
proto_register_field_array(proto_pktgen, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
}
void proto_reg_handoff_pktgen(void)
{
/* Register as a heuristic UDP dissector */
heur_dissector_add("udp", dissect_pktgen, "Linux Kernel Packet Generator over UDP", "pktgen_udp", proto_pktgen, HEURISTIC_ENABLE);
}
/*
* Editor modelines - https://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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