/* packet-udld.c * Routines for the disassembly of the "UniDirectional Link Detection" * * Wireshark - Network traffic analyzer * By Gerald Combs * Copyright 1998 Gerald Combs * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version 2 * of the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ #include "config.h" #include #include /* * See * * http://www.ietf.org/internet-drafts/draft-foschiano-udld-02.txt * * for some information on UDLD. */ /* Offsets in TLV structure. */ #define TLV_TYPE 0 #define TLV_LENGTH 2 void proto_register_udld(void); void proto_reg_handoff_udld(void); static int proto_udld = -1; static int hf_udld_version = -1; static int hf_udld_opcode = -1; static int hf_udld_flags = -1; static int hf_udld_flags_rt = -1; static int hf_udld_flags_rsy = -1; static int hf_udld_checksum = -1; static int hf_udld_tlvtype = -1; static int hf_udld_tlvlength = -1; static int hf_udld_device_id = -1; static int hf_udld_sent_through_interface = -1; static int hf_udld_data = -1; static expert_field ei_udld_tlvlength = EI_INIT; static gint ett_udld = -1; static gint ett_udld_flags = -1; static gint ett_udld_tlv = -1; #define TYPE_DEVICE_ID 0x0001 #define TYPE_PORT_ID 0x0002 #define TYPE_ECHO 0x0003 #define TYPE_MESSAGE_INTERVAL 0x0004 #define TYPE_TIMEOUT_INTERVAL 0x0005 #define TYPE_DEVICE_NAME 0x0006 #define TYPE_SEQUENCE_NUMBER 0x0007 static const value_string type_vals[] = { { TYPE_DEVICE_ID, "Device ID" }, { TYPE_PORT_ID, "Port ID" }, { TYPE_ECHO, "Echo" }, { TYPE_MESSAGE_INTERVAL, "Message interval" }, { TYPE_TIMEOUT_INTERVAL, "Timeout interval" }, { TYPE_DEVICE_NAME, "Device name" }, { TYPE_SEQUENCE_NUMBER, "Sequence number" }, { 0, NULL } }; #define OPCODE_RESERVED 0x00 #define OPCODE_PROBE 0x01 #define OPCODE_ECHO 0x02 #define OPCODE_FLUSH 0x03 static const value_string opcode_vals[] = { { OPCODE_RESERVED, "Reserved" }, { OPCODE_PROBE, "Probe" }, { OPCODE_ECHO, "Echo" }, { OPCODE_FLUSH, "Flush" }, { 0, NULL } }; static int dissect_udld(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_) { proto_item *ti; proto_tree *udld_tree = NULL; int offset = 0; guint16 type; guint16 length; proto_tree *tlv_tree; int real_length; col_set_str(pinfo->cinfo, COL_PROTOCOL, "UDLD"); col_clear(pinfo->cinfo, COL_INFO); if (tree) { proto_item *flags_ti; proto_tree *flags_tree; ti = proto_tree_add_item(tree, proto_udld, tvb, offset, -1, ENC_NA); udld_tree = proto_item_add_subtree(ti, ett_udld); /* UDLD header */ proto_tree_add_item(udld_tree, hf_udld_version, tvb, offset, 1, ENC_BIG_ENDIAN); proto_tree_add_item(udld_tree, hf_udld_opcode, tvb, offset, 1, ENC_BIG_ENDIAN); offset += 1; flags_ti = proto_tree_add_item(udld_tree, hf_udld_flags, tvb, offset, 1, ENC_BIG_ENDIAN); flags_tree = proto_item_add_subtree(flags_ti, ett_udld_flags); proto_tree_add_item(flags_tree, hf_udld_flags_rt, tvb, offset, 1, ENC_BIG_ENDIAN); proto_tree_add_item(flags_tree, hf_udld_flags_rsy, tvb, offset, 1, ENC_BIG_ENDIAN); offset += 1; proto_tree_add_item(udld_tree, hf_udld_checksum, tvb, offset, 2, ENC_BIG_ENDIAN); offset += 2; } else { offset += 4; /* The version/opcode/flags/checksum fields from above */ } while (tvb_reported_length_remaining(tvb, offset) != 0) { type = tvb_get_ntohs(tvb, offset + TLV_TYPE); length = tvb_get_ntohs(tvb, offset + TLV_LENGTH); if (length < 4) { tlv_tree = proto_tree_add_subtree_format(udld_tree, tvb, offset, 4, ett_udld_tlv, NULL, "TLV with invalid length %u (< 4)", length); proto_tree_add_uint(tlv_tree, hf_udld_tlvtype, tvb, offset + TLV_TYPE, 2, type); ti = proto_tree_add_uint(tlv_tree, hf_udld_tlvlength, tvb, offset + TLV_LENGTH, 2, length); expert_add_info(pinfo, ti, &ei_udld_tlvlength); offset += 4; break; } switch (type) { case TYPE_DEVICE_ID: /* Device ID */ col_append_fstr(pinfo->cinfo, COL_INFO, "Device ID: %s ", tvb_format_stringzpad(tvb, offset + 4, length - 4)); if (tree) { tlv_tree = proto_tree_add_subtree_format(udld_tree, tvb, offset, length, ett_udld_tlv, NULL, "Device ID: %s", tvb_format_stringzpad(tvb, offset + 4, length - 4)); proto_tree_add_uint(tlv_tree, hf_udld_tlvtype, tvb, offset + TLV_TYPE, 2, type); proto_tree_add_uint(tlv_tree, hf_udld_tlvlength, tvb, offset + TLV_LENGTH, 2, length); proto_tree_add_item(tlv_tree, hf_udld_device_id, tvb, offset + 4, length - 4, ENC_ASCII|ENC_NA); } offset += length; break; case TYPE_PORT_ID: real_length = length; if (tvb_get_guint8(tvb, offset + real_length) != 0x00) { /* The length in the TLV doesn't appear to be the length of the TLV, as the byte just past it isn't the first byte of a 2-byte big-endian small integer; make the length of the TLV the length in the TLV, plus 4 bytes for the TLV type and length, minus 1 because that's what makes one capture work. */ real_length = length + 3; } col_append_fstr(pinfo->cinfo, COL_INFO, "Port ID: %s ", tvb_format_stringzpad(tvb, offset + 4, length - 4)); if (tree) { tlv_tree = proto_tree_add_subtree_format(udld_tree, tvb, offset, real_length, ett_udld_tlv, NULL, "Port ID: %s", tvb_format_text(tvb, offset + 4, real_length - 4)); proto_tree_add_uint(tlv_tree, hf_udld_tlvtype, tvb, offset + TLV_TYPE, 2, type); proto_tree_add_uint(tlv_tree, hf_udld_tlvlength, tvb, offset + TLV_LENGTH, 2, length); proto_tree_add_item(tlv_tree, hf_udld_sent_through_interface, tvb, offset + 4, real_length - 4, ENC_ASCII|ENC_NA); } offset += real_length; break; case TYPE_ECHO: case TYPE_MESSAGE_INTERVAL: case TYPE_TIMEOUT_INTERVAL: case TYPE_DEVICE_NAME: case TYPE_SEQUENCE_NUMBER: default: tlv_tree = proto_tree_add_subtree_format(udld_tree, tvb, offset, length, ett_udld_tlv, NULL, "Type: %s, length: %u", val_to_str(type, type_vals, "Unknown (0x%04x)"), length); proto_tree_add_uint(tlv_tree, hf_udld_tlvtype, tvb, offset + TLV_TYPE, 2, type); proto_tree_add_uint(tlv_tree, hf_udld_tlvlength, tvb, offset + TLV_LENGTH, 2, length); if (length > 4) { proto_tree_add_item(tlv_tree, hf_udld_data, tvb, offset + 4, length - 4, ENC_NA); } else { return offset; } offset += length; } } call_data_dissector(tvb_new_subset_remaining(tvb, offset), pinfo, udld_tree); return tvb_captured_length(tvb); } void proto_register_udld(void) { static hf_register_info hf[] = { { &hf_udld_version, { "Version", "udld.version", FT_UINT8, BASE_DEC, NULL, 0xE0, NULL, HFILL }}, { &hf_udld_opcode, { "Opcode", "udld.opcode", FT_UINT8, BASE_DEC, VALS(opcode_vals), 0x1F, NULL, HFILL }}, { &hf_udld_flags, { "Flags", "udld.flags", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }}, { &hf_udld_flags_rt, { "Recommended timeout", "udld.flags.rt", FT_UINT8, BASE_HEX, NULL, 0x80, NULL, HFILL }}, { &hf_udld_flags_rsy, { "ReSynch", "udld.flags.rsy", FT_UINT8, BASE_HEX, NULL, 0x40, NULL, HFILL }}, { &hf_udld_checksum, { "Checksum", "udld.checksum", FT_UINT16, BASE_HEX, NULL, 0x0, NULL, HFILL }}, { &hf_udld_tlvtype, { "Type", "udld.tlv.type", FT_UINT16, BASE_HEX, VALS(type_vals), 0x0, NULL, HFILL }}, { &hf_udld_tlvlength, { "Length", "udld.tlv.len", FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL }}, { &hf_udld_device_id, { "Device ID", "udld.device_id", FT_STRINGZ, BASE_NONE, NULL, 0x0, NULL, HFILL }}, { &hf_udld_sent_through_interface, { "Sent through Interface", "udld.sent_through_interface", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL }}, { &hf_udld_data, { "Data", "udld.data", FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL }}, }; static gint *ett[] = { &ett_udld, &ett_udld_flags, &ett_udld_tlv }; static ei_register_info ei[] = { { &ei_udld_tlvlength, { "udld.tlv.len.invalid", PI_PROTOCOL, PI_WARN, "TLV with invalid length (< 4)", EXPFILL }}, }; expert_module_t* expert_udld; proto_udld = proto_register_protocol("Unidirectional Link Detection", "UDLD", "udld"); proto_register_field_array(proto_udld, hf, array_length(hf)); proto_register_subtree_array(ett, array_length(ett)); expert_udld = expert_register_protocol(proto_udld); expert_register_field_array(expert_udld, ei, array_length(ei)); } void proto_reg_handoff_udld(void) { dissector_handle_t udld_handle; udld_handle = create_dissector_handle(dissect_udld, proto_udld); dissector_add_uint("llc.cisco_pid", 0x0111, udld_handle); dissector_add_uint("chdlc.protocol", 0x0111, udld_handle); } /* * Editor modelines - http://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: */