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/*
* Copyright (c) 1998-2007 The TCPDUMP project
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that: (1) source code
* distributions retain the above copyright notice and this paragraph
* in its entirety, and (2) distributions including binary code include
* the above copyright notice and this paragraph in its entirety in
* the documentation or other materials provided with the distribution.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND
* WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT
* LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE.
*
* Reference documentation:
* https://www.cisco.com/c/en/us/support/docs/lan-switching/vtp/10558-21.html
* https://docstore.mik.ua/univercd/cc/td/doc/product/lan/trsrb/frames.htm
*
* Original code ode by Carles Kishimoto <carles.kishimoto@gmail.com>
*/
/* \summary: Cisco VLAN Trunking Protocol (VTP) printer */
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include "netdissect-stdinc.h"
#define ND_LONGJMP_FROM_TCHECK
#include "netdissect.h"
#include "addrtoname.h"
#include "extract.h"
#define VTP_HEADER_LEN 36
#define VTP_DOMAIN_NAME_LEN 32
#define VTP_MD5_DIGEST_LEN 16
#define VTP_UPDATE_TIMESTAMP_LEN 12
#define VTP_VLAN_INFO_FIXED_PART_LEN 12 /* length of VLAN info before VLAN name */
#define VTP_SUMMARY_ADV 0x01
#define VTP_SUBSET_ADV 0x02
#define VTP_ADV_REQUEST 0x03
#define VTP_JOIN_MESSAGE 0x04
struct vtp_vlan_ {
nd_uint8_t len;
nd_uint8_t status;
nd_uint8_t type;
nd_uint8_t name_len;
nd_uint16_t vlanid;
nd_uint16_t mtu;
nd_uint32_t index;
};
static const struct tok vtp_message_type_values[] = {
{ VTP_SUMMARY_ADV, "Summary advertisement"},
{ VTP_SUBSET_ADV, "Subset advertisement"},
{ VTP_ADV_REQUEST, "Advertisement request"},
{ VTP_JOIN_MESSAGE, "Join message"},
{ 0, NULL }
};
static const struct tok vtp_header_values[] = {
{ 0x01, "Followers"}, /* On Summary advertisement, 3rd byte is Followers */
{ 0x02, "Seq number"}, /* On Subset advertisement, 3rd byte is Sequence number */
{ 0x03, "Rsvd"}, /* On Adver. requests 3rd byte is Rsvd */
{ 0x04, "Rsvd"}, /* On Adver. requests 3rd byte is Rsvd */
{ 0, NULL }
};
static const struct tok vtp_vlan_type_values[] = {
{ 0x01, "Ethernet"},
{ 0x02, "FDDI"},
{ 0x03, "TrCRF"},
{ 0x04, "FDDI-net"},
{ 0x05, "TrBRF"},
{ 0, NULL }
};
static const struct tok vtp_vlan_status[] = {
{ 0x00, "Operational"},
{ 0x01, "Suspended"},
{ 0, NULL }
};
#define VTP_VLAN_SOURCE_ROUTING_RING_NUMBER 0x01
#define VTP_VLAN_SOURCE_ROUTING_BRIDGE_NUMBER 0x02
#define VTP_VLAN_STP_TYPE 0x03
#define VTP_VLAN_PARENT_VLAN 0x04
#define VTP_VLAN_TRANS_BRIDGED_VLAN 0x05
#define VTP_VLAN_PRUNING 0x06
#define VTP_VLAN_BRIDGE_TYPE 0x07
#define VTP_VLAN_ARP_HOP_COUNT 0x08
#define VTP_VLAN_STE_HOP_COUNT 0x09
#define VTP_VLAN_BACKUP_CRF_MODE 0x0A
static const struct tok vtp_vlan_tlv_values[] = {
{ VTP_VLAN_SOURCE_ROUTING_RING_NUMBER, "Source-Routing Ring Number TLV"},
{ VTP_VLAN_SOURCE_ROUTING_BRIDGE_NUMBER, "Source-Routing Bridge Number TLV"},
{ VTP_VLAN_STP_TYPE, "STP type TLV"},
{ VTP_VLAN_PARENT_VLAN, "Parent VLAN TLV"},
{ VTP_VLAN_TRANS_BRIDGED_VLAN, "Translationally bridged VLANs TLV"},
{ VTP_VLAN_PRUNING, "Pruning TLV"},
{ VTP_VLAN_BRIDGE_TYPE, "Bridge Type TLV"},
{ VTP_VLAN_ARP_HOP_COUNT, "Max ARP Hop Count TLV"},
{ VTP_VLAN_STE_HOP_COUNT, "Max STE Hop Count TLV"},
{ VTP_VLAN_BACKUP_CRF_MODE, "Backup CRF Mode TLV"},
{ 0, NULL }
};
static const struct tok vtp_stp_type_values[] = {
{ 1, "SRT"},
{ 2, "SRB"},
{ 3, "Auto"},
{ 0, NULL }
};
void
vtp_print(netdissect_options *ndo,
const u_char *pptr, const u_int length)
{
u_int type, len, name_len, tlv_len, tlv_value, mgmtd_len;
const u_char *tptr;
const struct vtp_vlan_ *vtp_vlan;
ndo->ndo_protocol = "vtp";
if (length < VTP_HEADER_LEN)
goto invalid;
tptr = pptr;
ND_TCHECK_LEN(tptr, VTP_HEADER_LEN);
type = GET_U_1(tptr + 1);
ND_PRINT("VTPv%u, Message %s (0x%02x), length %u",
GET_U_1(tptr),
tok2str(vtp_message_type_values,"Unknown message type", type),
type,
length);
/* In non-verbose mode, just print version and message type */
if (ndo->ndo_vflag < 1) {
goto tcheck_full_packet;
}
/* verbose mode print all fields */
ND_PRINT("\n\tDomain name: ");
mgmtd_len = GET_U_1(tptr + 3);
if (mgmtd_len < 1 || mgmtd_len > VTP_DOMAIN_NAME_LEN) {
ND_PRINT(" [invalid MgmtD Len %u]", mgmtd_len);
goto invalid;
}
nd_printjnp(ndo, tptr + 4, mgmtd_len);
ND_PRINT(", %s: %u",
tok2str(vtp_header_values, "Unknown", type),
GET_U_1(tptr + 2));
tptr += VTP_HEADER_LEN;
switch (type) {
case VTP_SUMMARY_ADV:
/*
* SUMMARY ADVERTISEMENT
*
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Version | Code | Followers | MgmtD Len |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Management Domain Name (zero-padded to 32 bytes) |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Configuration revision number |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Updater Identity IP address |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Update Timestamp (12 bytes) |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | MD5 digest (16 bytes) |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*
*/
ND_PRINT("\n\t Config Rev %x, Updater %s",
GET_BE_U_4(tptr),
GET_IPADDR_STRING(tptr+4));
tptr += 8;
ND_PRINT(", Timestamp 0x%08x 0x%08x 0x%08x",
GET_BE_U_4(tptr),
GET_BE_U_4(tptr + 4),
GET_BE_U_4(tptr + 8));
tptr += VTP_UPDATE_TIMESTAMP_LEN;
ND_PRINT(", MD5 digest: %08x%08x%08x%08x",
GET_BE_U_4(tptr),
GET_BE_U_4(tptr + 4),
GET_BE_U_4(tptr + 8),
GET_BE_U_4(tptr + 12));
tptr += VTP_MD5_DIGEST_LEN;
break;
case VTP_SUBSET_ADV:
/*
* SUBSET ADVERTISEMENT
*
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Version | Code | Seq number | MgmtD Len |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Management Domain Name (zero-padded to 32 bytes) |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Configuration revision number |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | VLAN info field 1 |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | ................ |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | VLAN info field N |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*
*/
ND_PRINT(", Config Rev %x", GET_BE_U_4(tptr));
/*
* VLAN INFORMATION
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | V info len | Status | VLAN type | VLAN name len |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | ISL vlan id | MTU size |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | 802.10 index (SAID) |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | VLAN name |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*
*/
tptr += 4;
while ((unsigned)(tptr - pptr) < length) {
len = GET_U_1(tptr);
if (len == 0)
break;
ND_TCHECK_LEN(tptr, len);
vtp_vlan = (const struct vtp_vlan_*)tptr;
if (len < VTP_VLAN_INFO_FIXED_PART_LEN)
goto invalid;
ND_PRINT("\n\tVLAN info status %s, type %s, VLAN-id %u, MTU %u, SAID 0x%08x, Name ",
tok2str(vtp_vlan_status,"Unknown",GET_U_1(vtp_vlan->status)),
tok2str(vtp_vlan_type_values,"Unknown",GET_U_1(vtp_vlan->type)),
GET_BE_U_2(vtp_vlan->vlanid),
GET_BE_U_2(vtp_vlan->mtu),
GET_BE_U_4(vtp_vlan->index));
len -= VTP_VLAN_INFO_FIXED_PART_LEN;
tptr += VTP_VLAN_INFO_FIXED_PART_LEN;
name_len = GET_U_1(vtp_vlan->name_len);
if (len < 4*((name_len + 3)/4))
goto invalid;
nd_printjnp(ndo, tptr, name_len);
/*
* Vlan names are aligned to 32-bit boundaries.
*/
len -= 4*((name_len + 3)/4);
tptr += 4*((name_len + 3)/4);
/* TLV information follows */
while (len > 0) {
/*
* Cisco specs say 2 bytes for type + 2 bytes for length;
* see https://docstore.mik.ua/univercd/cc/td/doc/product/lan/trsrb/frames.htm
* However, actual packets on the wire appear to use 1
* byte for the type and 1 byte for the length, so that's
* what we do.
*/
if (len < 2)
goto invalid;
type = GET_U_1(tptr);
tlv_len = GET_U_1(tptr + 1);
ND_PRINT("\n\t\t%s (0x%04x) TLV",
tok2str(vtp_vlan_tlv_values, "Unknown", type),
type);
if (len < tlv_len * 2 + 2) {
ND_PRINT(" (TLV goes past the end of the packet)");
goto invalid;
}
ND_TCHECK_LEN(tptr, tlv_len * 2 + 2);
/*
* We assume the value is a 2-byte integer; the length is
* in units of 16-bit words.
*/
if (tlv_len != 1) {
ND_PRINT(" (invalid TLV length %u != 1)", tlv_len);
goto invalid;
} else {
tlv_value = GET_BE_U_2(tptr + 2);
switch (type) {
case VTP_VLAN_STE_HOP_COUNT:
ND_PRINT(", %u", tlv_value);
break;
case VTP_VLAN_PRUNING:
ND_PRINT(", %s (%u)",
tlv_value == 1 ? "Enabled" : "Disabled",
tlv_value);
break;
case VTP_VLAN_STP_TYPE:
ND_PRINT(", %s (%u)",
tok2str(vtp_stp_type_values, "Unknown", tlv_value),
tlv_value);
break;
case VTP_VLAN_BRIDGE_TYPE:
ND_PRINT(", %s (%u)",
tlv_value == 1 ? "SRB" : "SRT",
tlv_value);
break;
case VTP_VLAN_BACKUP_CRF_MODE:
ND_PRINT(", %s (%u)",
tlv_value == 1 ? "Backup" : "Not backup",
tlv_value);
break;
/*
* FIXME those are the defined TLVs that lack a decoder
* you are welcome to contribute code ;-)
*/
case VTP_VLAN_SOURCE_ROUTING_RING_NUMBER:
case VTP_VLAN_SOURCE_ROUTING_BRIDGE_NUMBER:
case VTP_VLAN_PARENT_VLAN:
case VTP_VLAN_TRANS_BRIDGED_VLAN:
case VTP_VLAN_ARP_HOP_COUNT:
default:
print_unknown_data(ndo, tptr, "\n\t\t ", 2 + tlv_len*2);
break;
}
}
len -= 2 + tlv_len*2;
tptr += 2 + tlv_len*2;
}
}
break;
case VTP_ADV_REQUEST:
/*
* ADVERTISEMENT REQUEST
*
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Version | Code | Reserved | MgmtD Len |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Management Domain Name (zero-padded to 32 bytes) |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Start value |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*
*/
ND_PRINT("\n\tStart value: %u", GET_BE_U_4(tptr));
break;
case VTP_JOIN_MESSAGE:
/* FIXME - Could not find message format */
break;
default:
break;
}
return;
invalid:
nd_print_invalid(ndo);
tcheck_full_packet:
ND_TCHECK_LEN(pptr, length);
}
|
