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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.
*
* Original code by Carles Kishimoto <carles.kishimoto@gmail.com>
*/
/* \summary: Dynamic Trunking Protocol (DTP) printer */
#include <config.h>
#include "netdissect-stdinc.h"
#define ND_LONGJMP_FROM_TCHECK
#include "netdissect.h"
#include "addrtoname.h"
#include "extract.h"
#define DTP_HEADER_LEN 1
#define DTP_DOMAIN_TLV 0x0001
#define DTP_STATUS_TLV 0x0002
#define DTP_DTP_TYPE_TLV 0x0003
#define DTP_NEIGHBOR_TLV 0x0004
static const struct tok dtp_tlv_values[] = {
{ DTP_DOMAIN_TLV, "Domain" },
{ DTP_STATUS_TLV, "Status" },
{ DTP_DTP_TYPE_TLV, "DTP type" },
{ DTP_NEIGHBOR_TLV, "Neighbor" },
{ 0, NULL}
};
void
dtp_print(netdissect_options *ndo, const u_char *tptr, u_int length)
{
ndo->ndo_protocol = "dtp";
if (length < DTP_HEADER_LEN) {
ND_PRINT("[zero packet length]");
goto invalid;
}
ND_PRINT("DTPv%u, length %u",
GET_U_1(tptr),
length);
/*
* In non-verbose mode, just print version.
*/
if (ndo->ndo_vflag < 1) {
return;
}
tptr += DTP_HEADER_LEN;
length -= DTP_HEADER_LEN;
while (length) {
uint16_t type, len;
if (length < 4) {
ND_PRINT("[%u bytes remaining]", length);
goto invalid;
}
type = GET_BE_U_2(tptr);
len = GET_BE_U_2(tptr + 2);
/* XXX: should not be but sometimes it is, see the test captures */
if (type == 0)
return;
ND_PRINT("\n\t%s (0x%04x) TLV, length %u",
tok2str(dtp_tlv_values, "Unknown", type),
type, len);
/* infinite loop check */
if (len < 4 || len > length) {
ND_PRINT("[TLV length %u]", len);
goto invalid;
}
switch (type) {
case DTP_DOMAIN_TLV:
ND_PRINT(", ");
nd_printjnp(ndo, tptr+4, len-4);
break;
case DTP_STATUS_TLV:
case DTP_DTP_TYPE_TLV:
if (len != 5)
goto invalid;
ND_PRINT(", 0x%x", GET_U_1(tptr + 4));
break;
case DTP_NEIGHBOR_TLV:
if (len != 10)
goto invalid;
ND_PRINT(", %s", GET_ETHERADDR_STRING(tptr+4));
break;
default:
ND_TCHECK_LEN(tptr, len);
break;
}
tptr += len;
length -= len;
}
return;
invalid:
nd_print_invalid(ndo);
ND_TCHECK_LEN(tptr, length);
}
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