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wireshark/epan/dissectors/packet-cdp.c
Guy Harris 83fc9d5e09 Constify a bunch of stuff, to squelch -Wwrite-strings warnings. 
epan/dissectors/packet-ncp2222.inc is a bit hard to fix, so we're not
ready to enable that warning by default yet.

Throw in some casts to handle GLib routines that take arbitrary
non-const pointers (they can later return the pointers, and some
callers might want to modify or free up those pointers in cases where
they're known to be writable or allocated).

Use ep_tvb_memdup() rather than a combination of ep_alloc() and
tvb_memcpy().

Clean up some indentation.

svn path=/trunk/; revision=25601
2008-06-25 09:12:35 +00:00

1117 lines
36 KiB
C
Raw Blame History

/* packet-cdp.c
* Routines for the disassembly of the "Cisco Discovery Protocol"
* (c) Copyright Hannes R. Boehm <hannes@boehm.org>
*
* $Id$
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* 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.
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include <stdlib.h>
#include <string.h>
#include <glib.h>
#include <epan/packet.h>
#include <epan/strutil.h>
#include <epan/in_cksum.h>
#include <epan/oui.h>
#include <epan/nlpid.h>
/*
* See
*
* http://www.cisco.com/univercd/cc/td/doc/product/lan/trsrb/frames.htm#xtocid12
*
* for some information on CDP.
*
* See
*
* http://www.cisco.com/en/US/products/hw/switches/ps663/products_tech_note09186a0080094713.shtml#cdp
*
* for some more information on CDP version 2.
*/
/* 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_checksum = -1;
static int hf_cdp_checksum_good = -1;
static int hf_cdp_checksum_bad = -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 gint ett_cdp_address = -1;
static gint ett_cdp_capabilities = -1;
static gint ett_cdp_checksum = -1;
static dissector_handle_t data_handle;
static int
dissect_address_tlv(tvbuff_t *tvb, int offset, int length, proto_tree *tree);
static void
dissect_capabilities(tvbuff_t *tvb, int offset, int length, proto_tree *tree);
static void
add_multi_line_string_to_tree(proto_tree *tree, tvbuff_t *tvb, gint start,
gint len, const gchar *prefix);
#define TYPE_DEVICE_ID 0x0001
#define TYPE_ADDRESS 0x0002
#define TYPE_PORT_ID 0x0003
#define TYPE_CAPABILITIES 0x0004
#define TYPE_IOS_VERSION 0x0005
#define TYPE_PLATFORM 0x0006
#define TYPE_IP_PREFIX 0x0007
#define TYPE_PROTOCOL_HELLO 0x0008 /* Protocol Hello */
#define TYPE_VTP_MGMT_DOMAIN 0x0009 /* VTP Domain, CTPv2 - see second URL */
#define TYPE_NATIVE_VLAN 0x000a /* Native VLAN, CTPv2 - see second URL */
#define TYPE_DUPLEX 0x000b /* Full/Half Duplex - see second URL */
/* 0x000c */
/* 0x000d */
#define TYPE_VOIP_VLAN_REPLY 0x000e /* VoIP VLAN reply */
#define TYPE_VOIP_VLAN_QUERY 0x000f /* VoIP VLAN query */
#define TYPE_POWER 0x0010 /* Power consumption */
#define TYPE_MTU 0x0011 /* MTU */
#define TYPE_TRUST_BITMAP 0x0012 /* Trust bitmap */
#define TYPE_UNTRUSTED_COS 0x0013 /* Untrusted port CoS */
#define TYPE_SYSTEM_NAME 0x0014 /* System Name */
#define TYPE_SYSTEM_OID 0x0015 /* System OID */
#define TYPE_MANAGEMENT_ADDR 0x0016 /* Management Address(es) */
#define TYPE_LOCATION 0x0017 /* Location */
#define TYPE_EXT_PORT_ID 0x0018 /* External Port-ID */
#define TYPE_POWER_REQUESTED 0x0019 /* Power Requested */
#define TYPE_POWER_AVAILABLE 0x001a /* Power Available */
#define TYPE_PORT_UNIDIR 0x001b /* Port Unidirectional */
static const value_string type_vals[] = {
{ TYPE_DEVICE_ID, "Device ID" },
{ TYPE_ADDRESS, "Addresses" },
{ TYPE_PORT_ID, "Port ID" },
{ TYPE_CAPABILITIES, "Capabilities" },
{ TYPE_IOS_VERSION, "Software version" },
{ TYPE_PLATFORM, "Platform" },
{ TYPE_IP_PREFIX, "IP Prefix/Gateway (used for ODR)" },
{ TYPE_PROTOCOL_HELLO, "Protocol Hello" },
{ TYPE_VTP_MGMT_DOMAIN, "VTP Management Domain" },
{ TYPE_NATIVE_VLAN, "Native VLAN" },
{ TYPE_DUPLEX, "Duplex" },
{ TYPE_VOIP_VLAN_REPLY, "VoIP VLAN Reply" },
{ TYPE_VOIP_VLAN_QUERY, "VoIP VLAN Query" },
{ TYPE_POWER, "Power consumption" },
{ TYPE_MTU, "MTU"},
{ TYPE_TRUST_BITMAP, "Trust Bitmap" },
{ TYPE_UNTRUSTED_COS, "Untrusted Port CoS" },
{ TYPE_SYSTEM_NAME, "System Name" },
{ TYPE_SYSTEM_OID, "System Object ID" },
{ TYPE_MANAGEMENT_ADDR, "Management Address" },
{ TYPE_LOCATION, "Location" },
{ TYPE_EXT_PORT_ID, "External Port-ID" },
{ TYPE_POWER_REQUESTED, "Power Requested" },
{ TYPE_POWER_AVAILABLE, "Power Available" },
{ TYPE_PORT_UNIDIR, "Port Unidirectional" },
{ 0, NULL }
};
#define TYPE_HELLO_CLUSTER_MGMT 0x0112
static const value_string type_hello_vals[] = {
{ TYPE_HELLO_CLUSTER_MGMT, "Cluster Management" },
{ 0, NULL }
};
static void
dissect_cdp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
proto_item *ti, *checksum_item;
proto_tree *cdp_tree = NULL, *checksum_tree;
int offset = 0;
guint16 type;
guint16 length, packet_checksum, computed_checksum, data_length;
gboolean checksum_good, checksum_bad;
proto_item *tlvi = NULL;
proto_tree *tlv_tree = NULL;
int real_length;
guint32 naddresses;
guint32 power_avail_len, power_avail;
guint32 power_req_len, power_req;
int addr_length;
guint32 ip_addr;
vec_t cksum_vec[1];
if (check_col(pinfo->cinfo, COL_PROTOCOL))
col_set_str(pinfo->cinfo, COL_PROTOCOL, "CDP");
if (check_col(pinfo->cinfo, COL_INFO))
col_clear(pinfo->cinfo, COL_INFO);
if (tree) {
ti = proto_tree_add_item(tree, proto_cdp, tvb, offset, -1, FALSE);
cdp_tree = proto_item_add_subtree(ti, ett_cdp);
/* CDP header */
proto_tree_add_item(cdp_tree, hf_cdp_version, tvb, offset, 1, FALSE);
offset += 1;
proto_tree_add_uint_format_value(cdp_tree, hf_cdp_ttl, tvb, offset, 1,
tvb_get_guint8(tvb, offset),
"%u seconds",
tvb_get_guint8(tvb, offset));
offset += 1;
} else {
offset += 2; /* The version/ttl fields from above */
}
/* Checksum display & verification code */
packet_checksum = tvb_get_ntohs(tvb, offset);
data_length = tvb_reported_length(tvb);
cksum_vec[0].ptr = tvb_get_ptr(tvb, 0, data_length);
cksum_vec[0].len = data_length;
computed_checksum = in_cksum(cksum_vec, 1);
checksum_good = (computed_checksum == 0);
checksum_bad = !checksum_good;
if (checksum_good) {
checksum_item = proto_tree_add_uint_format(cdp_tree,
hf_cdp_checksum, tvb, offset, 2, packet_checksum,
"Checksum: 0x%04x [correct]", packet_checksum);
} else {
checksum_item = proto_tree_add_uint_format(cdp_tree,
hf_cdp_checksum, tvb, offset, 2, packet_checksum,
"Checksum: 0x%04x [incorrect, should be 0x%04x]",
packet_checksum,
in_cksum_shouldbe(packet_checksum, computed_checksum));
}
checksum_tree = proto_item_add_subtree(checksum_item, ett_cdp_checksum);
checksum_item = proto_tree_add_boolean(checksum_tree, hf_cdp_checksum_good,
tvb, offset, 2, checksum_good);
PROTO_ITEM_SET_GENERATED(checksum_item);
checksum_item = proto_tree_add_boolean(checksum_tree, hf_cdp_checksum_bad,
tvb, offset, 2, checksum_bad);
PROTO_ITEM_SET_GENERATED(checksum_item);
offset += 2;
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(cdp_tree, tvb, offset, 4,
"TLV with invalid length %u (< 4)",
length);
tlv_tree = proto_item_add_subtree(tlvi, ett_cdp_tlv);
proto_tree_add_uint(tlv_tree, hf_cdp_tlvtype, tvb,
offset + TLV_TYPE, 2, type);
proto_tree_add_uint(tlv_tree, hf_cdp_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(cdp_tree, tvb, offset,
length, "Device ID: %s",
tvb_format_stringzpad(tvb, offset + 4, length - 4));
tlv_tree = proto_item_add_subtree(tlvi, ett_cdp_tlv);
proto_tree_add_uint(tlv_tree, hf_cdp_tlvtype, tvb,
offset + TLV_TYPE, 2, type);
proto_tree_add_uint(tlv_tree, hf_cdp_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(cdp_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_cdp_tlv);
proto_tree_add_uint(tlv_tree, hf_cdp_tlvtype, tvb,
offset + TLV_TYPE, 2, type);
proto_tree_add_uint(tlv_tree, hf_cdp_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_ADDRESS:
/* Addresses */
if (tree) {
tlvi = proto_tree_add_text(cdp_tree, tvb, offset,
length, "Addresses");
tlv_tree = proto_item_add_subtree(tlvi, ett_cdp_tlv);
proto_tree_add_uint(tlv_tree, hf_cdp_tlvtype, tvb,
offset + TLV_TYPE, 2, type);
proto_tree_add_uint(tlv_tree, hf_cdp_tlvlength, tvb,
offset + TLV_LENGTH, 2, length);
}
offset += 4;
length -= 4;
naddresses = tvb_get_ntohl(tvb, offset);
if (tree) {
proto_tree_add_text(tlv_tree, tvb, offset, 4,
"Number of addresses: %u", naddresses);
}
offset += 4;
length -= 4;
while (naddresses != 0) {
addr_length = dissect_address_tlv(tvb, offset, length,
tlv_tree);
if (addr_length < 0)
break;
offset += addr_length;
length -= addr_length;
naddresses--;
}
offset += length;
break;
case TYPE_CAPABILITIES:
if (tree) {
tlvi = proto_tree_add_text(cdp_tree, tvb, offset,
length, "Capabilities");
tlv_tree = proto_item_add_subtree(tlvi, ett_cdp_tlv);
proto_tree_add_uint(tlv_tree, hf_cdp_tlvtype, tvb,
offset + TLV_TYPE, 2, type);
proto_tree_add_uint(tlv_tree, hf_cdp_tlvlength, tvb,
offset + TLV_LENGTH, 2, length);
}
offset += 4;
length -= 4;
dissect_capabilities(tvb, offset, length, tlv_tree);
offset += length;
break;
case TYPE_IOS_VERSION:
if (tree) {
tlvi = proto_tree_add_text(cdp_tree, tvb, offset,
length, "Software Version");
tlv_tree = proto_item_add_subtree(tlvi, ett_cdp_tlv);
proto_tree_add_uint(tlv_tree, hf_cdp_tlvtype, tvb,
offset + TLV_TYPE, 2, type);
proto_tree_add_uint(tlv_tree, hf_cdp_tlvlength, tvb,
offset + TLV_LENGTH, 2, length);
add_multi_line_string_to_tree(tlv_tree, tvb, offset + 4,
length - 4, "Software Version: ");
}
offset += length;
break;
case TYPE_PLATFORM:
/* ??? platform */
if (tree) {
tlvi = proto_tree_add_text(cdp_tree, tvb,
offset, length, "Platform: %s",
tvb_format_text(tvb, offset + 4, length - 4));
tlv_tree = proto_item_add_subtree(tlvi, ett_cdp_tlv);
proto_tree_add_uint(tlv_tree, hf_cdp_tlvtype, tvb,
offset + TLV_TYPE, 2, type);
proto_tree_add_uint(tlv_tree, hf_cdp_tlvlength, tvb,
offset + TLV_LENGTH, 2, length);
proto_tree_add_text(tlv_tree, tvb, offset + 4,
length - 4, "Platform: %s",
tvb_format_text(tvb, offset + 4, length - 4));
}
offset += length;
break;
case TYPE_IP_PREFIX:
if (length == 8) {
/* if length is 8 then this is default gw not prefix */
if (tree) {
tlvi = proto_tree_add_text(cdp_tree, tvb, offset,
length, "ODR Default gateway: %s",
ip_to_str(tvb_get_ptr(tvb, offset+4, 4)));
tlv_tree = proto_item_add_subtree(tlvi, ett_cdp_tlv);
proto_tree_add_uint(tlv_tree, hf_cdp_tlvtype, tvb,
offset + TLV_TYPE, 2, type);
proto_tree_add_uint(tlv_tree, hf_cdp_tlvlength, tvb,
offset + TLV_LENGTH, 2, length);
proto_tree_add_text(tlv_tree, tvb, offset+4, 4,
"ODR Default gateway = %s",
ip_to_str(tvb_get_ptr(tvb, offset+4, 4)));
}
offset += 8;
} else {
if (tree) {
tlvi = proto_tree_add_text(cdp_tree, tvb, offset,
length, "IP Prefixes: %d",length/5);
/* the actual number of prefixes is (length-4)/5
but if the variable is not a "float" but "integer"
then length/5=(length-4)/5 :) */
tlv_tree = proto_item_add_subtree(tlvi, ett_cdp_tlv);
proto_tree_add_uint(tlv_tree, hf_cdp_tlvtype, tvb,
offset + TLV_TYPE, 2, type);
proto_tree_add_uint(tlv_tree, hf_cdp_tlvlength, tvb,
offset + TLV_LENGTH, 2, length);
}
offset += 4;
length -= 4;
while (length > 0) {
if (tree) {
proto_tree_add_text(tlv_tree, tvb, offset, 5,
"IP Prefix = %s/%u",
ip_to_str(tvb_get_ptr(tvb, offset, 4)),
tvb_get_guint8(tvb,offset+4));
}
offset += 5;
length -= 5;
}
}
break;
case TYPE_PROTOCOL_HELLO:
if (tree) {
tlvi = proto_tree_add_text(cdp_tree, tvb,
offset,length, "Protocol Hello: %s",
val_to_str(tvb_get_ntohs(tvb, offset+7), type_hello_vals, "Unknown (0x%04x)"));
tlv_tree = proto_item_add_subtree(tlvi, ett_cdp_tlv);
proto_tree_add_uint(tlv_tree, hf_cdp_tlvtype, tvb,
offset + TLV_TYPE, 2, type);
proto_tree_add_uint(tlv_tree, hf_cdp_tlvlength, tvb,
offset + TLV_LENGTH, 2, length);
proto_tree_add_text(tlv_tree, tvb, offset+4, 3,
"OUI: 0x%06X (%s)",
tvb_get_ntoh24(tvb,offset+4),
val_to_str(tvb_get_ntoh24(tvb,offset+4), oui_vals, "Unknown"));
proto_tree_add_text(tlv_tree, tvb, offset+7, 2,
"Protocol ID: 0x%04X (%s)",
tvb_get_ntohs(tvb, offset+7),
val_to_str(tvb_get_ntohs(tvb, offset+7), type_hello_vals, "Unknown"));
switch(tvb_get_ntohs(tvb, offset+7)) {
case TYPE_HELLO_CLUSTER_MGMT:
/* proto_tree_add_text(tlv_tree, tvb, offset+9,
length - 9, "Cluster Management");
*/
ip_addr = tvb_get_ipv4(tvb, offset+9);
proto_tree_add_text(tlv_tree, tvb, offset+9, 4,
"Cluster Master IP: %s",ip_to_str((guint8 *)&ip_addr));
ip_addr = tvb_get_ipv4(tvb, offset+13);
proto_tree_add_text(tlv_tree, tvb, offset+13, 4,
"UNKNOWN (IP?): 0x%08X (%s)",
ip_addr, ip_to_str((guint8 *)&ip_addr));
proto_tree_add_text(tlv_tree, tvb, offset+17, 1,
"Version?: 0x%02X",
tvb_get_guint8(tvb, offset+17));
proto_tree_add_text(tlv_tree, tvb, offset+18, 1,
"Sub Version?: 0x%02X",
tvb_get_guint8(tvb, offset+18));
proto_tree_add_text(tlv_tree, tvb, offset+19, 1,
"Status?: 0x%02X",
tvb_get_guint8(tvb, offset+19));
proto_tree_add_text(tlv_tree, tvb, offset+20, 1,
"UNKNOWN: 0x%02X",
tvb_get_guint8(tvb, offset+20));
proto_tree_add_text(tlv_tree, tvb, offset+21, 6,
"Cluster Commander MAC: %s",
ether_to_str(tvb_get_ptr(tvb, offset+21, 6)));
proto_tree_add_text(tlv_tree, tvb, offset+27, 6,
"Switch's MAC: %s",
ether_to_str(tvb_get_ptr(tvb, offset+27, 6)));
proto_tree_add_text(tlv_tree, tvb, offset+33, 1,
"UNKNOWN: 0x%02X",
tvb_get_guint8(tvb, offset+33));
proto_tree_add_text(tlv_tree, tvb, offset+34, 2,
"Management VLAN: %d",
tvb_get_ntohs(tvb, offset+34));
break;
default:
proto_tree_add_text(tlv_tree, tvb, offset + 9,
length - 9, "Unknown");
break;
}
}
offset += length;
break;
case TYPE_VTP_MGMT_DOMAIN:
if (tree) {
tlvi = proto_tree_add_text(cdp_tree, tvb,
offset, length, "VTP Management Domain: %s",
tvb_format_text(tvb, offset + 4, length - 4));
tlv_tree = proto_item_add_subtree(tlvi, ett_cdp_tlv);
proto_tree_add_uint(tlv_tree, hf_cdp_tlvtype, tvb,
offset + TLV_TYPE, 2, type);
proto_tree_add_uint(tlv_tree, hf_cdp_tlvlength, tvb,
offset + TLV_LENGTH, 2, length);
proto_tree_add_text(tlv_tree, tvb, offset + 4,
length - 4, "VTP Management Domain: %s",
tvb_format_text(tvb, offset + 4, length - 4));
}
offset += length;
break;
case TYPE_NATIVE_VLAN:
if (tree) {
tlvi = proto_tree_add_text(cdp_tree, tvb,
offset, length, "Native VLAN: %u",
tvb_get_ntohs(tvb, offset + 4));
tlv_tree = proto_item_add_subtree(tlvi, ett_cdp_tlv);
proto_tree_add_uint(tlv_tree, hf_cdp_tlvtype, tvb,
offset + TLV_TYPE, 2, type);
proto_tree_add_uint(tlv_tree, hf_cdp_tlvlength, tvb,
offset + TLV_LENGTH, 2, length);
proto_tree_add_text(tlv_tree, tvb, offset + 4,
length - 4, "Native VLAN: %u",
tvb_get_ntohs(tvb, offset + 4));
}
offset += length;
break;
case TYPE_DUPLEX:
if (tree) {
tlvi = proto_tree_add_text(cdp_tree, tvb,
offset, length, "Duplex: %s",
tvb_get_guint8(tvb, offset + 4) ?
"Full" : "Half" );
tlv_tree = proto_item_add_subtree(tlvi, ett_cdp_tlv);
proto_tree_add_uint(tlv_tree, hf_cdp_tlvtype, tvb,
offset + TLV_TYPE, 2, type);
proto_tree_add_uint(tlv_tree, hf_cdp_tlvlength, tvb,
offset + TLV_LENGTH, 2, length);
proto_tree_add_text(tlv_tree, tvb, offset + 4,
length - 4, "Duplex: %s",
tvb_get_guint8(tvb, offset + 4) ?
"Full" : "Half" );
}
offset += length;
break;
case TYPE_VOIP_VLAN_REPLY:
if (tree) {
if (length >= 7) {
tlvi = proto_tree_add_text(cdp_tree, tvb, offset, length,
"VoIP VLAN Reply: %u", tvb_get_ntohs(tvb, offset + 5));
} else {
/*
* XXX - what are these? I've seen them in some captures;
* they have a length of 6, and run up to the end of
* the packet, so if we try to dissect it the same way
* we dissect the 7-byte ones, we report a malformed
* frame.
*/
tlvi = proto_tree_add_text(cdp_tree, tvb,
offset, length, "VoIP VLAN Reply");
}
tlv_tree = proto_item_add_subtree(tlvi, ett_cdp_tlv);
proto_tree_add_uint(tlv_tree, hf_cdp_tlvtype, tvb,
offset + TLV_TYPE, 2, type);
proto_tree_add_uint(tlv_tree, hf_cdp_tlvlength, tvb,
offset + TLV_LENGTH, 2, length);
proto_tree_add_text(tlv_tree, tvb, offset + 4,
1, "Data");
if (length >= 7) {
proto_tree_add_text(tlv_tree, tvb, offset + 5,
2, "Voice VLAN: %u",
tvb_get_ntohs(tvb, offset + 5));
}
}
offset += length;
break;
case TYPE_VOIP_VLAN_QUERY:
if (tree) {
if (length >= 7) {
tlvi = proto_tree_add_text(cdp_tree, tvb,
offset, length, "VoIP VLAN Query: %u", tvb_get_ntohs(tvb, offset + 5));
} else {
/*
* XXX - what are these? I've seen them in some captures;
* they have a length of 6, and run up to the end of
* the packet, so if we try to dissect it the same way
* we dissect the 7-byte ones, we report a malformed
* frame.
*/
tlvi = proto_tree_add_text(cdp_tree, tvb,
offset, length, "VoIP VLAN Query");
}
tlv_tree = proto_item_add_subtree(tlvi, ett_cdp_tlv);
proto_tree_add_uint(tlv_tree, hf_cdp_tlvtype, tvb,
offset + TLV_TYPE, 2, type);
proto_tree_add_uint(tlv_tree, hf_cdp_tlvlength, tvb,
offset + TLV_LENGTH, 2, length);
proto_tree_add_text(tlv_tree, tvb, offset + 4,
1, "Data");
if (length >= 7) {
proto_tree_add_text(tlv_tree, tvb, offset + 5,
2, "Voice VLAN: %u",
tvb_get_ntohs(tvb, offset + 5));
}
}
offset += length;
break;
case TYPE_POWER:
if (tree) {
tlvi = proto_tree_add_text(cdp_tree, tvb,
offset, length, "Power Consumption: %u mW",
tvb_get_ntohs(tvb, offset + 4));
tlv_tree = proto_item_add_subtree(tlvi, ett_cdp_tlv);
proto_tree_add_uint(tlv_tree, hf_cdp_tlvtype, tvb,
offset + TLV_TYPE, 2, type);
proto_tree_add_uint(tlv_tree, hf_cdp_tlvlength, tvb,
offset + TLV_LENGTH, 2, length);
proto_tree_add_text(tlv_tree, tvb, offset + 4,
length - 4, "Power Consumption: %u mW",
tvb_get_ntohs(tvb, offset + 4));
}
offset += length;
break;
case TYPE_MTU:
if (tree) {
tlvi = proto_tree_add_text(cdp_tree, tvb,
offset, length, "MTU: %u",
tvb_get_ntohl(tvb,offset + 4));
tlv_tree = proto_item_add_subtree(tlvi, ett_cdp_tlv);
proto_tree_add_uint(tlv_tree, hf_cdp_tlvtype, tvb,
offset + TLV_TYPE, 2, type);
proto_tree_add_uint(tlv_tree, hf_cdp_tlvlength, tvb,
offset + TLV_LENGTH, 2, length);
proto_tree_add_text(tlv_tree, tvb, offset + 4,
length - 4, "MTU: %u",
tvb_get_ntohl(tvb,offset + 4));
}
offset += length;
break;
case TYPE_TRUST_BITMAP:
if (tree) {
tlvi = proto_tree_add_text(cdp_tree, tvb,
offset, length, "Trust Bitmap: 0x%02X",
tvb_get_guint8(tvb, offset + 4));
tlv_tree = proto_item_add_subtree(tlvi, ett_cdp_tlv);
proto_tree_add_uint(tlv_tree, hf_cdp_tlvtype, tvb,
offset + TLV_TYPE, 2, type);
proto_tree_add_uint(tlv_tree, hf_cdp_tlvlength, tvb,
offset + TLV_LENGTH, 2, length);
proto_tree_add_text(tlv_tree, tvb, offset + 4,
length - 4, "Trust Bitmap: %02x",
tvb_get_guint8(tvb, offset + 4));
}
offset += length;
break;
case TYPE_UNTRUSTED_COS:
if (tree) {
tlvi = proto_tree_add_text(cdp_tree, tvb,
offset, length, "Untrusted port CoS: 0x%02X",
tvb_get_guint8(tvb, offset + 4));
tlv_tree = proto_item_add_subtree(tlvi, ett_cdp_tlv);
proto_tree_add_uint(tlv_tree, hf_cdp_tlvtype, tvb,
offset + TLV_TYPE, 2, type);
proto_tree_add_uint(tlv_tree, hf_cdp_tlvlength, tvb,
offset + TLV_LENGTH, 2, length);
proto_tree_add_text(tlv_tree, tvb, offset + 4,
length - 4, "Untrusted port CoS: %02x",
tvb_get_guint8(tvb, offset + 4));
}
offset += length;
break;
case TYPE_SYSTEM_NAME:
if (tree) {
tlvi = proto_tree_add_text(cdp_tree, tvb,
offset, length, "System Name: %s",
tvb_format_text(tvb, offset + 4, length - 4));
tlv_tree = proto_item_add_subtree(tlvi, ett_cdp_tlv);
proto_tree_add_uint(tlv_tree, hf_cdp_tlvtype, tvb,
offset + TLV_TYPE, 2, type);
proto_tree_add_uint(tlv_tree, hf_cdp_tlvlength, tvb,
offset + TLV_LENGTH, 2, length);
proto_tree_add_text(tlv_tree, tvb, offset + 4,
length - 4, "System Name: %s",
tvb_format_text(tvb, offset + 4, length - 4));
}
offset += length;
break;
case TYPE_SYSTEM_OID:
if (tree) {
tlvi = proto_tree_add_text(cdp_tree, tvb,
offset, length, "System Object Identifier");
tlv_tree = proto_item_add_subtree(tlvi, ett_cdp_tlv);
proto_tree_add_uint(tlv_tree, hf_cdp_tlvtype, tvb,
offset + TLV_TYPE, 2, type);
proto_tree_add_uint(tlv_tree, hf_cdp_tlvlength, tvb,
offset + TLV_LENGTH, 2, length);
proto_tree_add_text(tlv_tree, tvb, offset + 4,
length - 4, "System Object Identifier: %s",
tvb_bytes_to_str(tvb, offset + 4, length - 4));
}
offset += length;
break;
case TYPE_MANAGEMENT_ADDR:
if (tree) {
tlvi = proto_tree_add_text(cdp_tree, tvb,
offset, length, "Management Addresses");
tlv_tree = proto_item_add_subtree(tlvi, ett_cdp_tlv);
proto_tree_add_uint(tlv_tree, hf_cdp_tlvtype, tvb,
offset + TLV_TYPE, 2, type);
proto_tree_add_uint(tlv_tree, hf_cdp_tlvlength, tvb,
offset + TLV_LENGTH, 2, length);
}
offset += 4;
length -= 4;
naddresses = tvb_get_ntohl(tvb, offset);
if (tree) {
proto_tree_add_text(tlv_tree, tvb, offset, 4,
"Number of addresses: %u", naddresses);
}
offset += 4;
length -= 4;
while (naddresses != 0) {
addr_length = dissect_address_tlv(tvb, offset, length,
tlv_tree);
if (addr_length < 0)
break;
offset += addr_length;
length -= addr_length;
naddresses--;
}
offset += length;
break;
case TYPE_LOCATION:
if (tree) {
tlvi = proto_tree_add_text(cdp_tree, tvb,
offset, length, "Location: %s",
tvb_format_text(tvb, offset + 5, length - 5));
tlv_tree = proto_item_add_subtree(tlvi, ett_cdp_tlv);
proto_tree_add_uint(tlv_tree, hf_cdp_tlvtype, tvb,
offset + TLV_TYPE, 2, type);
proto_tree_add_uint(tlv_tree, hf_cdp_tlvlength, tvb,
offset + TLV_LENGTH, 2, length);
proto_tree_add_text(tlv_tree, tvb, offset + 4,
1 , "UNKNOWN: 0x%02X",
tvb_get_guint8(tvb, offset + 4));
proto_tree_add_text(tlv_tree, tvb, offset + 5,
length - 5, "Location: %s",
tvb_format_text(tvb, offset + 5, length - 5));
}
offset += length;
break;
case TYPE_POWER_REQUESTED:
if (tree) {
tlvi = proto_tree_add_text(cdp_tree, tvb,
offset, length, "Power Request: ");
tlv_tree = proto_item_add_subtree(tlvi, ett_cdp_tlv);
proto_tree_add_uint(tlv_tree, hf_cdp_tlvtype, tvb,
offset + TLV_TYPE, 2, type);
proto_tree_add_uint(tlv_tree, hf_cdp_tlvlength, tvb,
offset + TLV_LENGTH, 2, length);
proto_tree_add_text(tlv_tree, tvb, offset + 4,
2, "Request-ID: %u",
tvb_get_ntohs(tvb, offset + 4));
proto_tree_add_text(tlv_tree, tvb, offset + 6,
2, "Management-ID: %u",
tvb_get_ntohs(tvb, offset + 6));
}
power_req_len = (tvb_get_ntohs(tvb, offset + TLV_LENGTH)) - 8;
/* Move offset to where the list of Power Request Values Exist */
offset += 8;
while(power_req_len) {
if (power_req_len > 4) {
power_req = tvb_get_ntohl(tvb, offset);
if (tree) {
proto_tree_add_text(tlv_tree, tvb, offset,
4, "Power Requested: %u mW", power_req);
proto_item_append_text(tlvi, "%u mW, ", power_req);
}
power_req_len -= 4;
offset += 4;
} else {
if (power_req_len == 4) {
power_req = tvb_get_ntohl(tvb, offset);
if (tree) {
proto_tree_add_text(tlv_tree, tvb, offset,
4, "Power Requested: %u mW", power_req);
proto_item_append_text(tlvi, "%u mW", power_req);
}
}
offset += power_req_len;
break;
}
}
break;
case TYPE_POWER_AVAILABLE:
if (tree) {
tlvi = proto_tree_add_text(cdp_tree, tvb,
offset, length, "Power Available: ");
tlv_tree = proto_item_add_subtree(tlvi, ett_cdp_tlv);
proto_tree_add_uint(tlv_tree, hf_cdp_tlvtype, tvb,
offset + TLV_TYPE, 2, type);
proto_tree_add_uint(tlv_tree, hf_cdp_tlvlength, tvb,
offset + TLV_LENGTH, 2, length);
proto_tree_add_text(tlv_tree, tvb, offset + 4,
2, "Request-ID: %u",
tvb_get_ntohs(tvb, offset + 4));
proto_tree_add_text(tlv_tree, tvb, offset + 6,
2, "Management-ID: %u",
tvb_get_ntohs(tvb, offset + 6));
}
power_avail_len = (tvb_get_ntohs(tvb, offset + TLV_LENGTH)) - 8;
/* Move offset to where the list of Power Available Values Exist */
offset += 8;
while(power_avail_len) {
if (power_avail_len > 4) {
power_avail = tvb_get_ntohl(tvb, offset);
if (tree) {
proto_tree_add_text(tlv_tree, tvb, offset,
4, "Power Available: %u mW", power_avail);
proto_item_append_text(tlvi, "%u mW, ", power_avail);
}
power_avail_len -= 4;
offset += 4;
} else {
if (power_avail_len == 4) {
power_avail = tvb_get_ntohl(tvb, offset);
if (tree) {
proto_tree_add_text(tlv_tree, tvb, offset,
4, "Power Available: %u mW", power_avail);
proto_item_append_text(tlvi, "%u mW", power_avail);
}
}
offset += power_avail_len;
break;
}
}
break;
default:
if (tree) {
tlvi = proto_tree_add_text(cdp_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_cdp_tlv);
proto_tree_add_uint(tlv_tree, hf_cdp_tlvtype, tvb,
offset + TLV_TYPE, 2, type);
proto_tree_add_uint(tlv_tree, hf_cdp_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,
cdp_tree);
}
#define PROTO_TYPE_NLPID 1
#define PROTO_TYPE_IEEE_802_2 2
static const value_string proto_type_vals[] = {
{ PROTO_TYPE_NLPID, "NLPID" },
{ PROTO_TYPE_IEEE_802_2, "802.2" },
{ 0, NULL }
};
static int
dissect_address_tlv(tvbuff_t *tvb, int offset, int length, proto_tree *tree)
{
proto_item *ti;
proto_tree *address_tree;
guint8 protocol_type;
guint8 protocol_length;
int nlpid;
const char *protocol_str;
guint16 address_length;
const char *address_type_str;
const char *address_str;
if (length < 1)
return -1;
ti = proto_tree_add_text(tree, tvb, offset, length, "Truncated address");
address_tree = proto_item_add_subtree(ti, ett_cdp_address);
protocol_type = tvb_get_guint8(tvb, offset);
proto_tree_add_text(address_tree, tvb, offset, 1, "Protocol type: %s",
val_to_str(protocol_type, proto_type_vals, "Unknown (0x%02x)"));
offset += 1;
length -= 1;
if (length < 1)
return -1;
protocol_length = tvb_get_guint8(tvb, offset);
proto_tree_add_text(address_tree, tvb, offset, 1, "Protocol length: %u",
protocol_length);
offset += 1;
length -= 1;
if (length < protocol_length) {
if (length != 0) {
proto_tree_add_text(address_tree, tvb, offset, length,
"Protocol: %s (truncated)",
tvb_bytes_to_str(tvb, offset, length));
}
return -1;
}
protocol_str = NULL;
if (protocol_type == PROTO_TYPE_NLPID && protocol_length == 1) {
nlpid = tvb_get_guint8(tvb, offset);
protocol_str = val_to_str(nlpid, nlpid_vals, "Unknown (0x%02x)");
} else
nlpid = -1;
if (protocol_str == NULL)
protocol_str = tvb_bytes_to_str(tvb, offset, protocol_length);
proto_tree_add_text(address_tree, tvb, offset, protocol_length,
"Protocol: %s", protocol_str);
offset += protocol_length;
length -= protocol_length;
if (length < 2)
return -1;
address_length = tvb_get_ntohs(tvb, offset);
proto_tree_add_text(address_tree, tvb, offset, 2, "Address length: %u",
address_length);
offset += 2;
length -= 2;
if (length < address_length) {
if (length != 0) {
proto_tree_add_text(address_tree, tvb, offset, length,
"Address: %s (truncated)",
tvb_bytes_to_str(tvb, offset, length));
}
return -1;
}
/* XXX - the Cisco document seems to be saying that, for 802.2-format
protocol types, 0xAAAA03 0x000000 0x0800 is IPv6, but 0x0800 is
the Ethernet protocol type for IPv4. */
length = 2 + protocol_length + 2 + address_length;
address_type_str = NULL;
address_str = NULL;
if (protocol_type == PROTO_TYPE_NLPID && protocol_length == 1) {
switch (nlpid) {
/* XXX - dissect NLPID_ISO8473_CLNP as OSI CLNP address? */
case NLPID_IP:
if (address_length == 4) {
/* The address is an IP address. */
address_type_str = "IP address";
address_str = ip_to_str(tvb_get_ptr(tvb, offset, 4));
}
break;
}
}
if (address_type_str == NULL)
address_type_str = "Address";
if (address_str == NULL) {
address_str = tvb_bytes_to_str(tvb, offset, address_length);
}
proto_item_set_text(ti, "%s: %s", address_type_str, address_str);
proto_tree_add_text(address_tree, tvb, offset, address_length, "%s: %s",
address_type_str, address_str);
return 2 + protocol_length + 2 + address_length;
}
static void
dissect_capabilities(tvbuff_t *tvb, int offset, int length, proto_tree *tree)
{
proto_item *ti;
proto_tree *capabilities_tree;
guint32 capabilities;
if (length < 4)
return;
capabilities = tvb_get_ntohl(tvb, offset);
ti = proto_tree_add_text(tree, tvb, offset, length, "Capabilities: 0x%08x",
capabilities);
capabilities_tree = proto_item_add_subtree(ti, ett_cdp_capabilities);
proto_tree_add_text(capabilities_tree, tvb, offset, 4,
decode_boolean_bitfield(capabilities, 0x01, 4*8,
"Is a Router",
"Not a Router"));
proto_tree_add_text(capabilities_tree, tvb, offset, 4,
decode_boolean_bitfield(capabilities, 0x02, 4*8,
"Is a Transparent Bridge",
"Not a Transparent Bridge"));
proto_tree_add_text(capabilities_tree, tvb, offset, 4,
decode_boolean_bitfield(capabilities, 0x04, 4*8,
"Is a Source Route Bridge",
"Not a Source Route Bridge"));
proto_tree_add_text(capabilities_tree, tvb, offset, 4,
decode_boolean_bitfield(capabilities, 0x08, 4*8,
"Is a Switch",
"Not a Switch"));
proto_tree_add_text(capabilities_tree, tvb, offset, 4,
decode_boolean_bitfield(capabilities, 0x10, 4*8,
"Is a Host",
"Not a Host"));
proto_tree_add_text(capabilities_tree, tvb, offset, 4,
decode_boolean_bitfield(capabilities, 0x20, 4*8,
"Is IGMP capable",
"Not IGMP capable"));
proto_tree_add_text(capabilities_tree, tvb, offset, 4,
decode_boolean_bitfield(capabilities, 0x40, 4*8,
"Is a Repeater",
"Not a Repeater"));
}
static void
add_multi_line_string_to_tree(proto_tree *tree, tvbuff_t *tvb, gint start,
gint len, const gchar *prefix)
{
int prefix_len;
int i;
char blanks[64+1];
gint next;
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';
while (len > 0) {
line_len = tvb_find_line_end(tvb, start, len, &next, FALSE);
data_len = next - start;
proto_tree_add_text(tree, tvb, start, data_len, "%s%s", prefix,
tvb_format_stringzpad(tvb, start, line_len));
start += data_len;
len -= 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,
"", HFILL }},
{ &hf_cdp_ttl,
{ "TTL", "cdp.ttl", FT_UINT16, BASE_DEC, NULL, 0x0,
"", HFILL }},
{ &hf_cdp_checksum,
{ "Checksum", "cdp.checksum", FT_UINT16, BASE_HEX, NULL, 0x0,
"", HFILL }},
{ &hf_cdp_checksum_good,
{ "Good", "cdp.checksum_good", FT_BOOLEAN, BASE_NONE, NULL, 0x0,
"True: checksum matches packet content; False: doesn't match content or not checked", HFILL }},
{ &hf_cdp_checksum_bad,
{ "Bad ", "cdp.checksum_bad", FT_BOOLEAN, BASE_NONE, NULL, 0x0,
"True: checksum doesn't match packet content; False: matches content or not checked", HFILL }},
{ &hf_cdp_tlvtype,
{ "Type", "cdp.tlv.type", FT_UINT16, BASE_HEX, VALS(type_vals), 0x0,
"", HFILL }},
{ &hf_cdp_tlvlength,
{ "Length", "cdp.tlv.len", FT_UINT16, BASE_DEC, NULL, 0x0,
"", HFILL }}
};
static gint *ett[] = {
&ett_cdp,
&ett_cdp_tlv,
&ett_cdp_address,
&ett_cdp_capabilities,
&ett_cdp_checksum
};
proto_cdp = proto_register_protocol("Cisco Discovery Protocol",
"CDP", "cdp");
proto_register_field_array(proto_cdp, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
}
void
proto_reg_handoff_cdp(void)
{
dissector_handle_t cdp_handle;
data_handle = find_dissector("data");
cdp_handle = create_dissector_handle(dissect_cdp, proto_cdp);
dissector_add("llc.cisco_pid", 0x2000, cdp_handle);
dissector_add("chdlctype", 0x2000, cdp_handle);
dissector_add("ppp.protocol", 0x0207, cdp_handle);
}
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