/* packet-cdp.c * Routines for the disassembly of the "Cisco Discovery Protocol" * (c) Copyright Hannes R. Boehm * * $Id: packet-cdp.c,v 1.17 1999/11/16 11:42:28 guy Exp $ * * Ethereal - 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. */ #include "config.h" #ifdef HAVE_SYS_TYPES_H #include #endif #include #include #include #include "packet.h" /* Offsets in TLV structure. */ #define TLV_TYPE 0 #define TLV_LENGTH 2 static int proto_cdp = -1; static int hf_cdp_version = -1; static int hf_cdp_flags = -1; static int hf_cdp_ttl = -1; static int hf_cdp_tlvtype = -1; static int hf_cdp_tlvlength = -1; static gint ett_cdp = -1; static gint ett_cdp_tlv = -1; static void add_multi_line_string_to_tree(proto_tree *tree, gint start, gint len, const gchar *prefix, const gchar *string); #define TYPE_MGMT_ADDR 0 #define TYPE_CHASSIS_ID 1 #define TYPE_2 2 #define TYPE_PORT 3 #define TYPE_IOS_VERSION 5 #define TYPE_PLATFORM 6 #define TYPE_MGMT_IP_ADDR 0x01cc static const value_string type_vals[] = { { TYPE_MGMT_ADDR, "Mgmt addr?" }, { TYPE_CHASSIS_ID, "Chassis ID" }, { TYPE_2, "Unknown" }, { TYPE_PORT, "Port" }, { TYPE_IOS_VERSION, "Software version" }, { TYPE_PLATFORM, "Platform" }, { TYPE_MGMT_IP_ADDR, "Mgmt IP" }, { 0, NULL }, }; void dissect_cdp(const u_char *pd, int offset, frame_data *fd, proto_tree *tree) { proto_item *ti; proto_tree *cdp_tree = NULL; guint16 type; guint16 length; char *type_str; char *stringmem; proto_item *tlvi; proto_tree *tlv_tree; if (check_col(fd, COL_PROTOCOL)) col_add_str(fd, COL_PROTOCOL, "CDP"); if (check_col(fd, COL_INFO)) col_add_str(fd, COL_INFO, "Cisco Discovery Protocol"); if(tree){ ti = proto_tree_add_item(tree, proto_cdp, offset, END_OF_FRAME, NULL); cdp_tree = proto_item_add_subtree(ti, ett_cdp); /* CDP header */ proto_tree_add_item(cdp_tree, hf_cdp_version, offset, 1, pd[offset]); offset += 1; proto_tree_add_item_format(cdp_tree, hf_cdp_flags, offset, 1, pd[offset], "Flags: %x (unknown)", pd[offset]); offset += 1; proto_tree_add_item_format(cdp_tree, hf_cdp_ttl, offset, 2, pntohs(&pd[offset]), "TTL: %u (unknown)", pntohs(&pd[offset])); offset += 2; while( IS_DATA_IN_FRAME(offset) ){ type = pntohs(&pd[offset + TLV_TYPE]); length = pntohs(&pd[offset + TLV_LENGTH]); type_str = val_to_str(type, type_vals, "Unknown (0x%04x)"); switch( type ){ case TYPE_MGMT_ADDR: /* ??? Mgmt Addr; in this one, the "length" field doesn't include the length of the type and length fields. */ tlvi = proto_tree_add_text(cdp_tree, offset, length + 4, "Type: %s, length: %u", type_str, length); tlv_tree = proto_item_add_subtree(tlvi, ett_cdp_tlv); proto_tree_add_item(tlv_tree, hf_cdp_tlvtype, offset + TLV_TYPE, 2, type); proto_tree_add_item(tlv_tree, hf_cdp_tlvlength, offset + TLV_LENGTH, 2, length); if (length > 0) { proto_tree_add_text(tlv_tree, offset + 4, length, "Data"); } offset+=length + 4; break; case TYPE_CHASSIS_ID: /* ??? Chassis ID */ tlvi = proto_tree_add_text(cdp_tree, offset, length, "Chassis ID: %s", &pd[offset+4]); tlv_tree = proto_item_add_subtree(tlvi, ett_cdp_tlv); proto_tree_add_item(tlv_tree, hf_cdp_tlvtype, offset + TLV_TYPE, 2, type); proto_tree_add_item(tlv_tree, hf_cdp_tlvlength, offset + TLV_LENGTH, 2, length); proto_tree_add_text(tlv_tree, offset + 4, length - 4, "Chassis ID: %s", &pd[offset+4]); offset+=length; break; case TYPE_2: /* this is quite strange: this tlv contains no data itself but two tlvs which calculate the length without the 2 byte type and 2 byte length field */ tlvi = proto_tree_add_text(cdp_tree, offset, 4, "Type: %u (unknown), second field: %u", type, length); tlv_tree = proto_item_add_subtree(tlvi, ett_cdp_tlv); proto_tree_add_item(tlv_tree, hf_cdp_tlvtype, offset + TLV_TYPE, 2, type); proto_tree_add_text(tlv_tree, offset + TLV_LENGTH, 2, "Second field: %u", length); offset+=4; break; case TYPE_PORT: /* ??? Port */ tlvi = proto_tree_add_text(cdp_tree, offset, length, "Sent through Interface: %s", &pd[offset+4]); tlv_tree = proto_item_add_subtree(tlvi, ett_cdp_tlv); proto_tree_add_item(tlv_tree, hf_cdp_tlvtype, offset + TLV_TYPE, 2, type); proto_tree_add_item(tlv_tree, hf_cdp_tlvlength, offset + TLV_LENGTH, 2, length); proto_tree_add_text(tlv_tree, offset + 4, length - 4, "Sent through Interface: %s", &pd[offset+4]); offset+=length; break; case TYPE_IOS_VERSION: /* ??? IOS Version */ add_multi_line_string_to_tree(cdp_tree, offset + 4, length - 4, "Software Version: ", &pd[offset+4] ); offset+=length; break; case TYPE_PLATFORM: /* ??? platform */ stringmem = malloc(length); memset(stringmem, '\0', length); memcpy(stringmem, &pd[offset+4], length - 4 ); tlvi = proto_tree_add_text(cdp_tree, offset, length, "Platform: %s", stringmem); tlv_tree = proto_item_add_subtree(tlvi, ett_cdp_tlv); proto_tree_add_item(tlv_tree, hf_cdp_tlvtype, offset + TLV_TYPE, 2, type); proto_tree_add_item(tlv_tree, hf_cdp_tlvlength, offset + TLV_LENGTH, 2, length); proto_tree_add_text(tlv_tree, offset + 4, length - 4, "Platform: %s", stringmem); free(stringmem); offset+=length; break; case TYPE_MGMT_IP_ADDR: /* ??? Mgmt IP Addr; in this one, the "length" field doesn't include the length of the type and length fields. */ tlvi = proto_tree_add_text(cdp_tree, offset, length + 4, "Mgmt IP: %s", ip_to_str(&pd[offset+4])); tlv_tree = proto_item_add_subtree(tlvi, ett_cdp_tlv); proto_tree_add_item(tlv_tree, hf_cdp_tlvtype, offset + TLV_TYPE, 2, type); proto_tree_add_item(tlv_tree, hf_cdp_tlvlength, offset + TLV_LENGTH, 2, length); proto_tree_add_text(tlv_tree, offset + 4, length, "IP address: %s", ip_to_str(&pd[offset+4])); offset+=length + 4; break; default: tlvi = proto_tree_add_text(cdp_tree, offset, length, "Type: %s, length: %u", type_str, length); tlv_tree = proto_item_add_subtree(tlvi, ett_cdp_tlv); proto_tree_add_item(tlv_tree, hf_cdp_tlvtype, offset + TLV_TYPE, 2, type); proto_tree_add_item(tlv_tree, hf_cdp_tlvlength, offset + TLV_LENGTH, 2, length); if (length > 4) { proto_tree_add_text(tlv_tree, offset + 4, length - 4, "Data"); } else return; offset+=length; } } dissect_data(pd, offset, fd, cdp_tree); } } static void add_multi_line_string_to_tree(proto_tree *tree, gint start, gint len, const gchar *prefix, const gchar *string) { int prefix_len; int i; char blanks[64+1]; const gchar *p, *q; int line_len; int data_len; prefix_len = strlen(prefix); if (prefix_len > 64) prefix_len = 64; for (i = 0; i < prefix_len; i++) blanks[i] = ' '; blanks[i] = '\0'; p = string; for (;;) { q = strchr(p, '\n'); if (q != NULL) { line_len = q - p; data_len = line_len + 1; } else { line_len = strlen(p); data_len = line_len; } proto_tree_add_text(tree, start, data_len, "%s%.*s", prefix, line_len, p); if (q == NULL) break; p += data_len; start += data_len; prefix = blanks; } } void proto_register_cdp(void) { static hf_register_info hf[] = { { &hf_cdp_version, { "Version", "cdp.version", FT_UINT8, BASE_DEC, NULL, 0x0, "" }}, { &hf_cdp_flags, { "Flags", "cdp.flags", FT_UINT8, BASE_HEX, NULL, 0x0, "" }}, { &hf_cdp_ttl, { "TTL", "cdp.ttl", FT_UINT16, BASE_DEC, NULL, 0x0, "" }}, { &hf_cdp_tlvtype, { "Type", "cdp.tlv.type", FT_UINT16, BASE_HEX, VALS(type_vals), 0x0, "" }}, { &hf_cdp_tlvlength, { "Length", "cdp.tlv.len", FT_UINT16, BASE_DEC, NULL, 0x0, "" }}, }; static gint *ett[] = { &ett_cdp, &ett_cdp_tlv, }; proto_cdp = proto_register_protocol("Cisco Discovery Protocol", "cdp"); proto_register_field_array(proto_cdp, hf, array_length(hf)); proto_register_subtree_array(ett, array_length(ett)); }