wireshark/epan/dissectors/packet-cisco-marker.c

210 lines
6.8 KiB
C

/* packet-cisco-marker.c
* Routines for CISCO's ERSPAN3 Marker Packet
* See: http://www.cisco.com/c/en/us/products/collateral/switches/nexus-9000-series-switches/white-paper-c11-733921.html#_Toc413144488
* See: https://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus9000/sw/93x/system-management/b-cisco-nexus-9000-series-nx-os-system-management-configuration-guide-93x/b-cisco-nexus-9000-series-nx-os-system-management-configuration-guide-93x_chapter_011110.html
* Copyright 2015, Peter Membrey
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
*
* Copied from packet-time.c
* Fixed with additional documentation from Cisco and real-life observations
* by Stéphane Lapie <stephane.lapie@darkbsd.org>
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
#include "config.h"
#include <epan/packet.h>
void proto_register_erspan_marker(void);
void proto_reg_handoff_erspan_marker(void);
static dissector_handle_t marker_handle;
static int proto_marker = -1;
static int hf_cisco_erspan_granularity = -1;
static int hf_cisco_erspan_info = -1;
static int hf_cisco_erspan_prop_header = -1;
static int hf_cisco_erspan_reserved = -1;
static int hf_cisco_erspan_sequence_number = -1;
static int hf_cisco_erspan_ssid = -1;
static int hf_cisco_erspan_tail = -1;
static int hf_cisco_erspan_timestamp = -1;
static int hf_cisco_erspan_type = -1;
static int hf_cisco_erspan_utc_sec = -1;
static int hf_cisco_erspan_utc_usec = -1;
static int hf_cisco_erspan_utcoffset = -1;
static int hf_cisco_erspan_version = -1;
static gint ett_marker = -1;
static int
dissect_marker(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
{
proto_tree *marker_tree;
proto_item *ti;
col_set_str(pinfo->cinfo, COL_PROTOCOL, "CISCO ERSPAN3 MARKER");
if (tree) {
/* Skip the proprietary CISCO header - no docs have been released for this */
guint32 offset = 20;
ti = proto_tree_add_item(tree, proto_marker, tvb, 0, -1, ENC_NA);
marker_tree = proto_item_add_subtree(ti, ett_marker);
proto_tree_add_item(marker_tree, hf_cisco_erspan_prop_header, tvb, 0, 20, ENC_NA);
proto_tree_add_item(marker_tree, hf_cisco_erspan_info, tvb, offset, 2, ENC_LITTLE_ENDIAN);
offset += 2;
proto_tree_add_item(marker_tree, hf_cisco_erspan_version, tvb, offset, 2, ENC_BIG_ENDIAN);
proto_tree_add_item(marker_tree, hf_cisco_erspan_type, tvb, offset, 2, ENC_BIG_ENDIAN);
proto_tree_add_item(marker_tree, hf_cisco_erspan_ssid, tvb, offset, 2, ENC_BIG_ENDIAN);
offset += 2;
proto_tree_add_item(marker_tree, hf_cisco_erspan_granularity, tvb, offset, 2, ENC_BIG_ENDIAN);
proto_tree_add_item(marker_tree, hf_cisco_erspan_utcoffset, tvb, offset, 2, ENC_BIG_ENDIAN);
offset+= 2;
proto_tree_add_item(marker_tree, hf_cisco_erspan_timestamp, tvb, offset, 8, ENC_BIG_ENDIAN);
offset+=8;
proto_tree_add_item(marker_tree, hf_cisco_erspan_utc_sec, tvb, offset, 4, ENC_BIG_ENDIAN);
offset+=4;
proto_tree_add_item(marker_tree, hf_cisco_erspan_utc_usec, tvb, offset, 4, ENC_BIG_ENDIAN);
offset+=4;
proto_tree_add_item(marker_tree, hf_cisco_erspan_sequence_number, tvb, offset, 4, ENC_LITTLE_ENDIAN);
offset+=4;
proto_tree_add_item(marker_tree, hf_cisco_erspan_reserved, tvb, offset, 4, ENC_LITTLE_ENDIAN);
offset+=4;
proto_tree_add_item(marker_tree, hf_cisco_erspan_tail, tvb, offset, 8, ENC_BIG_ENDIAN);
}
return tvb_captured_length(tvb);
}
void
proto_register_erspan_marker(void)
{
static hf_register_info hf[] = {
{ &hf_cisco_erspan_prop_header,
{ "Proprietary CISCO Header", "erspan-marker.prop_header",
FT_BYTES, BASE_NONE, NULL, 0x0,
NULL, HFILL }
},
{ &hf_cisco_erspan_info,
{ "Header", "erspan-marker.header",
FT_BOOLEAN, 8, NULL, 0x0,
NULL, HFILL }
},
{ &hf_cisco_erspan_version,
{ "Version", "erspan-marker.version",
FT_UINT16, BASE_DEC, NULL, 0x0f00,
NULL, HFILL }
},
{ &hf_cisco_erspan_type,
{ "Type", "erspan-marker.type",
FT_UINT16, BASE_DEC, NULL, 0xf000,
NULL, HFILL }
},
{ &hf_cisco_erspan_ssid,
{ "SSID", "erspan-marker.ssid",
FT_UINT16, BASE_DEC, NULL, 0x00ff,
NULL, HFILL }
},
{ &hf_cisco_erspan_granularity,
{ "Granularity", "erspan-marker.granularity",
FT_UINT16, BASE_DEC, NULL, 0xff00,
NULL, HFILL }
},
{ &hf_cisco_erspan_utcoffset,
{ "UTC Offset", "erspan-marker.utc_offset",
FT_UINT16, BASE_DEC, NULL, 0x00ff,
NULL, HFILL }
},
/* Timestamp is actually a 48-bit value, packed across 2 32-bit integers
* Timestamp_hi : 0000 ffff (high 16-bits)
* Timestamp_lo : ffff ffff (low 32-bits) */
{ &hf_cisco_erspan_timestamp,
{ "ASIC 48-bit Timestamp", "erspan-marker.timestamp",
FT_UINT48, BASE_DEC, NULL, 0xffffffffffff,
NULL, HFILL }
},
/* Comparison between the actual packet arrival time and this field
* indicated that the Ethernet packet's arrival time was behind
* the below field value by the value of the UTC offset
* (37 seconds as of Nov 2021) */
{ &hf_cisco_erspan_utc_sec,
{ "UTC Seconds", "erspan-marker.utc_sec",
FT_UINT32, BASE_DEC, NULL, 0xffffffff,
NULL, HFILL }
},
{ &hf_cisco_erspan_utc_usec,
{ "UTC Microseconds", "erspan-marker.utc_usec",
FT_UINT32, BASE_DEC, NULL, 0xffffffff,
NULL, HFILL }
},
{ &hf_cisco_erspan_sequence_number,
{ "Sequence Number", "erspan-marker.sequence_number",
FT_UINT32, BASE_DEC, NULL, 0xffffffff,
NULL, HFILL }
},
{ &hf_cisco_erspan_reserved,
{ "Reserved", "erspan-marker.reserved",
FT_UINT32, BASE_DEC, NULL, 0xffffffff,
NULL, HFILL }
},
/* The 32-bit signature is expected to be 0xA5A5A5A5,
* and while the Cisco documentation does not mention packing details,
* it does mention padding values to enforce alignment */
{ &hf_cisco_erspan_tail,
{ "TAIL", "erspan-marker.tail",
FT_UINT64, BASE_HEX, NULL, 0x00000000ffffffff,
NULL, HFILL }
},
};
static gint *ett[] = {
&ett_marker,
};
proto_marker = proto_register_protocol("CISCO ERSPAN3 Marker Packet", "CISCO3 ERSPAN MARKER", "erspan-marker");
proto_register_field_array(proto_marker, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
marker_handle = create_dissector_handle(dissect_marker, proto_marker);
}
void
proto_reg_handoff_erspan_marker(void)
{
dissector_add_for_decode_as_with_preference("udp.port", marker_handle);
}
/*
* Editor modelines - https://www.wireshark.org/tools/modelines.html
*
* Local Variables:
* c-basic-offset: 2
* tab-width: 8
* indent-tabs-mode: nil
* End:
*
* ex: set shiftwidth=2 tabstop=8 expandtab:
* :indentSize=2:tabSize=8:noTabs=true:
*/