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/* packet-nxp_802154_sniffer.c
* Routines for NXP JN51xx 802.15.4 Sniffer application packet dissection
* Copyright 2017, Lee Mitchell <lee@indigopepper.com>
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
/*
* This dissector handles messages sent by either NXP's own sniffer server application,
* or the open source one provided on GitHub here:
* https://github.com/Codemonkey1973/JN51xx-802.15.4-Sniffer-Server
*
* When used with an NXP JN51xx wireless microcontroller running NXP's
* Sniffer firmware, the sniffer server prefixes any received packets
* with a short header and then sends them as a UDP datagrams. This dissector
* decodes the short header and then passes the 802.15.4 frame on to the
* IEEE 802.15.4 dissector for further dissection.
*
*/
#include "config.h"
#include <epan/packet.h>
#include <epan/exceptions.h>
#include "packet-ieee802154.h"
#define NXP_802154_SNIFFER_UDP_PORT 49999 /* Not IANA registered */
#define NXP_802154_SNIFFER_TIMESTAMP_LENGTH 5
void proto_reg_handoff_nxp_802154_sniffer(void);
void proto_register_nxp_802154_sniffer(void);
static int proto_nxp_802154_sniffer;
static int hf_nxp_802154_sniffer_timestamp;
static int hf_nxp_802154_sniffer_id;
static int hf_nxp_802154_sniffer_channel;
static int hf_nxp_802154_sniffer_lqi;
static int hf_nxp_802154_sniffer_length;
static int ett_nxp_802154_sniffer;
static dissector_handle_t nxp_802154_sniffer_handle;
static dissector_handle_t ieee802154_handle;
static bool
test_nxp_802154_sniffer(tvbuff_t *tvb, unsigned offset)
{
volatile bool valid = true;
uint8_t channel, frame_len;
TRY {
/* Skip Timestamp */
offset += NXP_802154_SNIFFER_TIMESTAMP_LENGTH;
/* ID must be a null terminated ASCII string.
* tvb_strsize can throw exceptions caught by CATCH_BOUNDS_ERRORS. */
offset += tvb_strsize(tvb, offset);
/* Channel must be between 11 and 26 (2.4 GHz PHY)
* XXX: In the future the channels below 11 (868 and 915 MHz PHY)
* might be possible */
channel = tvb_get_uint8(tvb, offset);
if (channel < 11 || channel > 26) {
valid = false;
}
/* Skip LQI, it can take any value from 0x00 to 0xff */
offset += 2;
frame_len = tvb_get_uint8(tvb, offset);
if (frame_len < IEEE802154_FCS_LEN || frame_len > IEEE802154_PHY_LENGTH_MASK) {
valid = false;
}
offset += 1;
if (tvb_reported_length_remaining(tvb, offset) != frame_len) {
valid = false;
}
}
CATCH_BOUNDS_ERRORS {
valid = false;
}
ENDTRY;
return valid;
}
static int
dissect_nxp_802154_sniffer(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
{
proto_item *ti;
proto_tree *nxp_802154_sniffer_tree;
unsigned offset = 0;
unsigned snifferidlen;
tvbuff_t *ieee802154_tvb;
/* Check that the packet is long enough for it to belong to us. */
if (tvb_reported_length(tvb) < 9)
return 0;
if (!test_nxp_802154_sniffer(tvb, offset)) {
return 0;
}
col_set_str(pinfo->cinfo, COL_PROTOCOL, "NXP 802.15.4 SNIFFER");
col_clear(pinfo->cinfo, COL_INFO);
ti = proto_tree_add_item(tree, proto_nxp_802154_sniffer, tvb, offset, -1, ENC_NA);
nxp_802154_sniffer_tree = proto_item_add_subtree(ti, ett_nxp_802154_sniffer);
/* Time stamp */
proto_tree_add_item(nxp_802154_sniffer_tree, hf_nxp_802154_sniffer_timestamp, tvb, offset, NXP_802154_SNIFFER_TIMESTAMP_LENGTH, ENC_BIG_ENDIAN);
offset += NXP_802154_SNIFFER_TIMESTAMP_LENGTH;
/* ID */
proto_tree_add_item_ret_length(nxp_802154_sniffer_tree, hf_nxp_802154_sniffer_id, tvb, offset, -1, ENC_ASCII|ENC_NA, &snifferidlen);
offset += snifferidlen;
/* Channel */
proto_tree_add_item(nxp_802154_sniffer_tree, hf_nxp_802154_sniffer_channel, tvb, offset, 1, ENC_BIG_ENDIAN);
offset += 1;
/* LQI */
proto_tree_add_item(nxp_802154_sniffer_tree, hf_nxp_802154_sniffer_lqi, tvb, offset, 1, ENC_BIG_ENDIAN);
offset += 1;
/* Length */
proto_tree_add_item(nxp_802154_sniffer_tree, hf_nxp_802154_sniffer_length, tvb, offset, 1, ENC_BIG_ENDIAN);
offset += 1;
ieee802154_tvb = tvb_new_subset_remaining(tvb, offset);
call_dissector(ieee802154_handle, ieee802154_tvb, pinfo, tree);
return tvb_captured_length(tvb);
}
void
proto_register_nxp_802154_sniffer(void)
{
static hf_register_info hf[] = {
{ &hf_nxp_802154_sniffer_timestamp,
{ "Timestamp (16uS Symbol Periods)", "nxp_802154_sniffer.timestamp", FT_UINT40, BASE_DEC, NULL, 0x0, NULL, HFILL } },
{ &hf_nxp_802154_sniffer_id,
{ "Sniffer ID", "nxp_802154_sniffer.id", FT_STRINGZ, BASE_NONE, NULL, 0x0, NULL, HFILL } },
{ &hf_nxp_802154_sniffer_channel,
{ "Channel", "nxp_802154_sniffer.channel", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL } },
{ &hf_nxp_802154_sniffer_lqi,
{ "LQI", "nxp_802154_sniffer.lqi", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL } },
{ &hf_nxp_802154_sniffer_length,
{ "Length", "nxp_802154_sniffer.length", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL } },
};
static int *ett[] = {
&ett_nxp_802154_sniffer,
};
proto_nxp_802154_sniffer = proto_register_protocol("NXP 802.15.4 Sniffer Protocol",
"NXP 802154 Sniffer",
"nxp_802154_sniffer");
proto_register_field_array(proto_nxp_802154_sniffer, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
nxp_802154_sniffer_handle = register_dissector("nxp_802154_sniffer", dissect_nxp_802154_sniffer, proto_nxp_802154_sniffer);
}
void
proto_reg_handoff_nxp_802154_sniffer(void)
{
ieee802154_handle = find_dissector_add_dependency("wpan", proto_nxp_802154_sniffer);
dissector_add_uint_with_preference("udp.port", NXP_802154_SNIFFER_UDP_PORT, nxp_802154_sniffer_handle);
}
/*
* 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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