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/* packet-isis.c
* Routines for ISO/OSI network and transport protocol packet disassembly, core
* bits.
*
* Stuart Stanley <stuarts@mxmail.net>
*
* 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/expert.h>
#include <epan/nlpid.h>
#include <epan/etypes.h>
#include "packet-osi.h"
#include "packet-isis.h"
void proto_register_isis(void);
void proto_reg_handoff_isis(void);
static dissector_table_t isis_dissector_table;
/* isis base header */
static int proto_isis;
static int hf_isis_irpd;
static int hf_isis_header_length;
static int hf_isis_version;
static int hf_isis_system_id_length;
static int hf_isis_type;
static int hf_isis_type_reserved;
static int hf_isis_version2;
static int hf_isis_reserved;
static int hf_isis_max_area_adr;
int hf_isis_clv_key_id;
static int ett_isis;
static expert_field ei_isis_length_indicator_too_small;
static expert_field ei_isis_version;
static expert_field ei_isis_version2;
static expert_field ei_isis_reserved;
static expert_field ei_isis_type;
static dissector_handle_t isis_handle;
static const value_string isis_vals[] = {
{ ISIS_TYPE_L1_HELLO, "L1 HELLO"},
{ ISIS_TYPE_L2_HELLO, "L2 HELLO"},
{ ISIS_TYPE_PTP_HELLO, "P2P HELLO"},
{ ISIS_TYPE_L1_LSP, "L1 LSP"},
{ ISIS_TYPE_L2_LSP, "L2 LSP"},
{ ISIS_TYPE_L1_CSNP, "L1 CSNP"},
{ ISIS_TYPE_L2_CSNP, "L2 CSNP"},
{ ISIS_TYPE_L1_PSNP, "L1 PSNP"},
{ ISIS_TYPE_L2_PSNP, "L2 PSNP"},
{ 0, NULL}
};
static int
dissect_isis(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
{
proto_item *ti, *version_item, *version2_item, *reserved_item;
proto_tree *isis_tree = NULL;
int offset = 0;
uint8_t isis_version, isis_version2, isis_reserved;
uint8_t isis_type;
isis_data_t subdissector_data;
col_set_str(pinfo->cinfo, COL_PROTOCOL, "ISIS");
col_clear(pinfo->cinfo, COL_INFO);
ti = proto_tree_add_item(tree, proto_isis, tvb, 0, -1, ENC_NA);
isis_tree = proto_item_add_subtree(ti, ett_isis);
proto_tree_add_item(isis_tree, hf_isis_irpd, tvb, offset, 1, ENC_BIG_ENDIAN );
offset += 1;
subdissector_data.header_length = tvb_get_uint8(tvb, offset);
subdissector_data.header_length_item =
proto_tree_add_uint(isis_tree, hf_isis_header_length, tvb,
offset, 1, subdissector_data.header_length );
offset += 1;
if (subdissector_data.header_length < 8) {
/* Not large enough to include the part of the header that
we dissect here. */
expert_add_info(pinfo, subdissector_data.header_length_item, &ei_isis_length_indicator_too_small);
return tvb_captured_length(tvb);
}
subdissector_data.ei_bad_header_length = &ei_isis_length_indicator_too_small;
isis_version = tvb_get_uint8(tvb, offset);
version_item = proto_tree_add_uint(isis_tree, hf_isis_version, tvb,
offset, 1, isis_version );
if (isis_version != ISIS_REQUIRED_VERSION){
expert_add_info(pinfo, version_item, &ei_isis_version);
}
offset += 1;
subdissector_data.system_id_len = tvb_get_uint8(tvb, offset);
proto_tree_add_uint(isis_tree, hf_isis_system_id_length, tvb,
offset, 1, subdissector_data.system_id_len );
offset += 1;
proto_tree_add_item(isis_tree, hf_isis_type_reserved, tvb, offset, 1, ENC_BIG_ENDIAN );
isis_type = tvb_get_uint8(tvb, offset) & ISIS_TYPE_MASK;
col_add_str(pinfo->cinfo, COL_INFO,
val_to_str ( isis_type, isis_vals, "Unknown (0x%x)" ) );
proto_tree_add_item(isis_tree, hf_isis_type, tvb, offset, 1, ENC_BIG_ENDIAN );
offset += 1;
isis_version2 = tvb_get_uint8(tvb, offset);
version2_item = proto_tree_add_item(isis_tree, hf_isis_version2, tvb, offset, 1, ENC_BIG_ENDIAN );
if (isis_version2 != 1) {
expert_add_info(pinfo, version2_item, &ei_isis_version2);
}
offset += 1;
isis_reserved = tvb_get_uint8(tvb, offset);
reserved_item = proto_tree_add_item(isis_tree, hf_isis_reserved, tvb, offset, 1, ENC_BIG_ENDIAN );
if (isis_reserved != 0) {
expert_add_info(pinfo, reserved_item, &ei_isis_reserved);
}
offset += 1;
proto_tree_add_item(isis_tree, hf_isis_max_area_adr, tvb, offset, 1, ENC_BIG_ENDIAN );
offset += 1;
/*
* Interpret the system ID length.
*/
if (subdissector_data.system_id_len == 0)
subdissector_data.system_id_len = 6; /* zero means 6-octet ID field length */
else if (subdissector_data.system_id_len == 255) {
subdissector_data.system_id_len = 0; /* 255 means null ID field */
/* XXX - what about the LAN ID? */
}
/* XXX - otherwise, must be in the range 1 through 8 */
/*
* We must pass the entire ISIS PDU to the dissector, as some
* dissectors are for ISIS PDU types that might contain a
* checksum TLV, and that checksum is over the entire PDU.
*/
if (!dissector_try_uint_new(isis_dissector_table, isis_type, tvb,
pinfo, tree, true, &subdissector_data))
{
proto_tree_add_expert(tree, pinfo, &ei_isis_type, tvb, offset, -1);
}
return tvb_captured_length(tvb);
} /* dissect_isis */
void
proto_register_isis(void)
{
static hf_register_info hf[] = {
{ &hf_isis_irpd,
{ "Intradomain Routing Protocol Discriminator", "isis.irpd",
FT_UINT8, BASE_HEX, VALS(nlpid_vals), 0x0, NULL, HFILL }},
{ &hf_isis_header_length,
{ "Length Indicator", "isis.len", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }},
{ &hf_isis_version,
{ "Version/Protocol ID Extension", "isis.version", FT_UINT8,
BASE_DEC, NULL, 0x0, NULL, HFILL }},
{ &hf_isis_system_id_length,
{ "ID Length", "isis.sysid_len",
FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }},
{ &hf_isis_type,
{ "PDU Type", "isis.type", FT_UINT8, BASE_DEC,
VALS(isis_vals), ISIS_TYPE_MASK, NULL, HFILL }},
{ &hf_isis_type_reserved,
{ "Reserved", "isis.type.reserved", FT_UINT8, BASE_HEX,
NULL, ISIS_TYPE_RESERVED_MASK, NULL, HFILL }},
{ &hf_isis_version2,
{ "Version", "isis.version2", FT_UINT8, BASE_DEC, NULL,
0x0, NULL, HFILL }},
{ &hf_isis_reserved,
{ "Reserved", "isis.reserved", FT_UINT8, BASE_DEC, NULL,
0x0, NULL, HFILL }},
{ &hf_isis_max_area_adr,
{ "Maximum Area Addresses", "isis.max_area_adr", FT_UINT8, BASE_DEC, NULL,
0x0, "Maximum Area Addresses, 0 means 3", HFILL }},
{ &hf_isis_clv_key_id,
{ "Key ID", "isis.clv.key_id", FT_UINT16, BASE_DEC, NULL,
0x0, NULL, HFILL }},
};
/*
* Note, we pull in the unknown CLV handler here, since it
* is used by all ISIS packet types.
*/
static int *ett[] = {
&ett_isis,
};
static ei_register_info ei[] = {
{ &ei_isis_length_indicator_too_small, { "isis.length_indicator_too_small", PI_MALFORMED, PI_ERROR, "ISIS length indicator value smaller than the fixed length header size", EXPFILL }},
{ &ei_isis_version, { "isis.version.unknown", PI_PROTOCOL, PI_WARN, "Unknown ISIS version", EXPFILL }},
{ &ei_isis_version2, { "isis.version2.notone", PI_PROTOCOL, PI_WARN, "Version must be 1", EXPFILL }},
{ &ei_isis_reserved, { "isis.reserved.notzero", PI_PROTOCOL, PI_WARN, "Reserved must be 0", EXPFILL }},
{ &ei_isis_type, { "isis.type.unknown", PI_PROTOCOL, PI_WARN, "Unknown ISIS packet type", EXPFILL }},
};
expert_module_t* expert_isis;
proto_isis = proto_register_protocol(PROTO_STRING_ISIS, "ISIS", "isis");
proto_register_field_array(proto_isis, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
expert_isis = expert_register_protocol(proto_isis);
expert_register_field_array(expert_isis, ei, array_length(ei));
isis_handle = register_dissector("isis", dissect_isis, proto_isis);
isis_dissector_table = register_dissector_table("isis.type",
"ISIS Type", proto_isis, FT_UINT8, BASE_DEC);
}
void
proto_reg_handoff_isis(void)
{
dissector_add_uint("osinl.incl", NLPID_ISO10589_ISIS, isis_handle);
dissector_add_uint("ethertype", ETHERTYPE_L2ISIS, isis_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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