/* packet-dtp.c * Routines for the disassembly for Cisco Dynamic Trunking Protocol * * $Id$ * * Ethereal - Network traffic analyzer * By Gerald Combs * Copyright 1998 Gerald Combs * * DTP support added by Charlie Lenahan * * 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. * */ #include "config.h" #include #include #include #include /* * It's incomplete, and it appears to be inaccurate in a number of places, * but it's all I could find.... */ static int proto_dtp = -1; static int hf_dtp_version = -1; static int hf_dtp_tlvtype = -1; static int hf_dtp_tlvlength = -1; static int hf_dtp_some_mac = -1; static gint ett_dtp = -1; static gint ett_dtp_tlv = -1; static void dissect_dtp_tlv(tvbuff_t *tvb, int offset, int length, proto_tree *tree, proto_item *ti, guint8 type); #define TRUNK_NAME_NUM 0x01 #define TYPE_2_NUM 0x02 #define TYPE_3_NUM 0x03 #define SOMEMAC_NUM 0x04 static const value_string dtp_tlv_type_vals[] = { { TRUNK_NAME_NUM, "Trunk Name" }, { TYPE_2_NUM, "Type 2" }, { TYPE_3_NUM, "Type 3" }, { SOMEMAC_NUM, "Some MAC" }, { 0, NULL } }; static void dissect_dtp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) { proto_item *ti; proto_tree *dtp_tree = NULL; proto_tree *tlv_tree=NULL; int offset = 0; if (check_col(pinfo->cinfo, COL_PROTOCOL)) col_set_str(pinfo->cinfo, COL_PROTOCOL, "DTP"); if (check_col(pinfo->cinfo, COL_INFO)) col_set_str(pinfo->cinfo, COL_INFO, "Dynamic Trunking Protocol"); if (tree) { ti = proto_tree_add_item(tree, proto_dtp, tvb, offset, -1, FALSE); dtp_tree = proto_item_add_subtree(ti, ett_dtp); } /* We assume version */ proto_tree_add_item(dtp_tree, hf_dtp_version, tvb, offset, 1, FALSE); offset += 1; while (tvb_reported_length_remaining(tvb, offset) > 0) { int type, length, valuelength; type = tvb_get_ntohs(tvb, offset); length = tvb_get_ntohs(tvb, offset + 2); valuelength = (length-4); /* make sure still in valid tlv */ if ((valuelength < 1) || ( length > tvb_length_remaining(tvb, offset) )) break; ti = proto_tree_add_text(dtp_tree, tvb, offset, length, "%s", val_to_str(type, dtp_tlv_type_vals, "Unknown TLV type: 0x%02x")); tlv_tree = proto_item_add_subtree(ti, ett_dtp_tlv); proto_tree_add_uint(tlv_tree, hf_dtp_tlvtype, tvb, offset, 2, type); offset+=2; proto_tree_add_uint(tlv_tree, hf_dtp_tlvlength, tvb, offset, 2, length); offset+=2; if (valuelength > 0) { dissect_dtp_tlv(tvb, offset, valuelength, tlv_tree, ti, (guint8) type); } offset += valuelength; } } static void dissect_dtp_tlv(tvbuff_t *tvb, int offset, int length, proto_tree *tree, proto_item *ti, guint8 type) { switch (type) { case TRUNK_NAME_NUM: if (length > 0) { proto_item_set_text(ti, "Trunk Name: %s", tvb_format_text(tvb, offset, length - 1)); proto_tree_add_text(tree, tvb, offset, length, "Trunk Name: %s", tvb_format_text(tvb, offset, length - 1)); } else { proto_item_set_text(ti, "Trunk Name: Bad length %u", length); proto_tree_add_text(tree, tvb, offset, length, "Trunk Name: Bad length %u", length); } break; case TYPE_2_NUM: if (length > 0) { proto_item_set_text(ti, "Type 2: 0x%02x", tvb_get_guint8(tvb, offset)); proto_tree_add_text(tree, tvb, offset, 1, "Type 2: 0x%02x", tvb_get_guint8(tvb, offset)); } else { proto_item_set_text(ti, "Type 2: Bad length %u", length); proto_tree_add_text(tree, tvb, offset, length, "Type 2: Bad length %u", length); } break; case TYPE_3_NUM: if (length > 0) { proto_item_set_text(ti, "Type 3: 0x%02x", tvb_get_guint8(tvb, offset)); proto_tree_add_text(tree, tvb, offset, 1, "Type 3: 0x%02x", tvb_get_guint8(tvb, offset)); } else { proto_item_set_text(ti, "Type 3: Bad length %u", length); proto_tree_add_text(tree, tvb, offset, length, "Type 3: Bad length %u", length); } break; case SOMEMAC_NUM: if (length == 6) { const guint8 *macptr=tvb_get_ptr(tvb,offset,length); proto_item_set_text(ti, "Some MAC: %s", ether_to_str(macptr)); /* XXX - resolve? */ proto_tree_add_ether(tree, hf_dtp_some_mac, tvb, offset,length,macptr); } else { proto_item_set_text(ti, "Some MAC: Bad length %u", length); proto_tree_add_text(tree, tvb, offset, length, "Some MAC: Bad length %u", length); } break; default: proto_tree_add_text(tree, tvb, offset, length, "Data"); break; } } void proto_register_dtp(void) { static hf_register_info hf[] = { { &hf_dtp_version, { "Version", "dtp.version", FT_UINT8, BASE_HEX, NULL, 0x0, "", HFILL }}, { &hf_dtp_tlvtype, { "Type", "dtp.tlv_type", FT_UINT16, BASE_HEX, VALS(dtp_tlv_type_vals), 0x0, "", HFILL }}, { &hf_dtp_tlvlength, { "Length", "dtp.tlv_len", FT_UINT16, BASE_DEC, NULL, 0x0, "", HFILL }}, { &hf_dtp_some_mac, { "Some MAC", "vtp.some_mac", FT_ETHER, BASE_NONE, NULL, 0x0, "MAC Address of something", HFILL }}, }; static gint *ett[] = { &ett_dtp, &ett_dtp_tlv, }; proto_dtp = proto_register_protocol("Dynamic Trunking Protocol", "DTP", "dtp"); proto_register_field_array(proto_dtp, hf, array_length(hf)); proto_register_subtree_array(ett, array_length(ett)); } void proto_reg_handoff_dtp(void) { dissector_handle_t dtp_handle; dtp_handle = create_dissector_handle(dissect_dtp, proto_dtp); dissector_add("llc.cisco_pid", 0x2004, dtp_handle); }