/* packet-udld.c * Routines for the disassembly of the "UniDirectional Link Detection" * * $Id: packet-udld.c 20479 2007-01-18 14:41:59Z martinm $ * * 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #ifdef HAVE_CONFIG_H # include "config.h" #endif #include #include #include #include #include #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 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 gint ett_udld = -1; static gint ett_udld_flags = -1; static gint ett_udld_tlv = -1; static dissector_handle_t data_handle; #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 void dissect_udld(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) { proto_item *ti; proto_tree *udld_tree = NULL; int offset = 0; guint16 type; guint16 length; proto_item *tlvi; proto_tree *tlv_tree; int real_length; if (check_col(pinfo->cinfo, COL_PROTOCOL)) col_set_str(pinfo->cinfo, COL_PROTOCOL, "UDLD"); if (check_col(pinfo->cinfo, COL_INFO)) 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, FALSE); udld_tree = proto_item_add_subtree(ti, ett_udld); /* UDLD header */ proto_tree_add_item(udld_tree, hf_udld_version, tvb, offset, 1, FALSE); proto_tree_add_item(udld_tree, hf_udld_opcode, tvb, offset, 1, FALSE); offset += 1; flags_ti = proto_tree_add_item(udld_tree, hf_udld_flags, tvb, offset, 1, FALSE); flags_tree = proto_item_add_subtree(ti, ett_udld_flags); proto_tree_add_item(flags_tree, hf_udld_flags_rt, tvb, offset, 1, FALSE); proto_tree_add_item(flags_tree, hf_udld_flags_rsy, tvb, offset, 1, FALSE); offset += 1; proto_tree_add_item(udld_tree, hf_udld_checksum, tvb, offset, 2, FALSE); 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) { if (tree) { tlvi = proto_tree_add_text(udld_tree, tvb, offset, 4, "TLV with invalid length %u (< 4)", length); tlv_tree = proto_item_add_subtree(tlvi, ett_udld_tlv); 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); } offset += 4; break; } switch (type) { case TYPE_DEVICE_ID: /* Device ID */ if (check_col(pinfo->cinfo, COL_INFO)) col_append_fstr(pinfo->cinfo, COL_INFO, "Device ID: %s ", tvb_format_stringzpad(tvb, offset + 4, length - 4)); if (tree) { tlvi = proto_tree_add_text(udld_tree, tvb, offset, length, "Device ID: %s", tvb_format_stringzpad(tvb, offset + 4, length - 4)); tlv_tree = proto_item_add_subtree(tlvi, ett_udld_tlv); 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_text(tlv_tree, tvb, offset + 4, length - 4, "Device ID: %s", tvb_format_stringzpad(tvb, offset + 4, length - 4)); } 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; } if (check_col(pinfo->cinfo, COL_INFO)) col_append_fstr(pinfo->cinfo, COL_INFO, "Port ID: %s ", tvb_format_stringzpad(tvb, offset + 4, length - 4)); if (tree) { tlvi = proto_tree_add_text(udld_tree, tvb, offset, real_length, "Port ID: %s", tvb_format_text(tvb, offset + 4, real_length - 4)); tlv_tree = proto_item_add_subtree(tlvi, ett_udld_tlv); 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_text(tlv_tree, tvb, offset + 4, real_length - 4, "Sent through Interface: %s", tvb_format_text(tvb, offset + 4, real_length - 4)); } offset += real_length; break; case TYPE_ECHO: case TYPE_MESSAGE_INTERVAL: case TYPE_TIMEOUT_INTERVAL: case TYPE_DEVICE_NAME: case TYPE_SEQUENCE_NUMBER: default: tlvi = proto_tree_add_text(udld_tree, tvb, offset, length, "Type: %s, length: %u", val_to_str(type, type_vals, "Unknown (0x%04x)"), length); tlv_tree = proto_item_add_subtree(tlvi, ett_udld_tlv); 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_text(tlv_tree, tvb, offset + 4, length - 4, "Data"); } else { return; } offset += length; } } call_dissector(data_handle, tvb_new_subset(tvb, offset, -1, -1), pinfo, udld_tree); } void proto_register_udld(void) { static hf_register_info hf[] = { { &hf_udld_version, { "Version", "udld.version", FT_UINT8, BASE_DEC, NULL, 0xE0, "", HFILL }}, { &hf_udld_opcode, { "Opcode", "udld.opcode", FT_UINT8, BASE_DEC, VALS(opcode_vals), 0x1F, "", HFILL }}, { &hf_udld_flags, { "Flags", "udld.flags", FT_UINT8, BASE_DEC, NULL, 0x0, "", HFILL }}, { &hf_udld_flags_rt, { "Recommended timeout", "udld.flags.rt", FT_UINT8, BASE_HEX, NULL, 0x80, "", HFILL }}, { &hf_udld_flags_rsy, { "ReSynch", "udld.flags.rsy", FT_UINT8, BASE_HEX, NULL, 0x40, "", HFILL }}, { &hf_udld_checksum, { "Checksum", "udld.checksum", FT_UINT16, BASE_HEX, NULL, 0x0, "", HFILL }}, { &hf_udld_tlvtype, { "Type", "udld.tlv.type", FT_UINT16, BASE_HEX, VALS(type_vals), 0x0, "", HFILL }}, { &hf_udld_tlvlength, { "Length", "udld.tlv.len", FT_UINT16, BASE_DEC, NULL, 0x0, "", HFILL }} }; static gint *ett[] = { &ett_udld, &ett_udld_flags, &ett_udld_tlv }; 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)); } void proto_reg_handoff_udld(void) { dissector_handle_t udld_handle; data_handle = find_dissector("data"); udld_handle = create_dissector_handle(dissect_udld, proto_udld); dissector_add("llc.cisco_pid", 0x0111, udld_handle); dissector_add("chdlctype", 0x0111, udld_handle); }