/*
 * Copyright (c) 1991, 1992, 1993, 1994, 1995, 1996, 1997
 *	The Regents of the University of California.  All rights reserved.
 *
 * 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, (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, and (3) all advertising materials mentioning
 * features or use of this software display the following acknowledgement:
 * ``This product includes software developed by the University of California,
 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
 * the University nor the names of its contributors may be used to endorse
 * or promote products derived from this software without specific prior
 * written permission.
 * 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.
 */

/* \summary: Fiber Distributed Data Interface (FDDI) printer */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <netdissect-stdinc.h>

#include <string.h>

#include "netdissect.h"
#include "addrtoname.h"
#include "ether.h"

/*
 * Based on Ultrix if_fddi.h
 */

struct fddi_header {
	u_char  fddi_fc;		/* frame control */
	u_char  fddi_dhost[6];
	u_char  fddi_shost[6];
};

/*
 * Length of an FDDI header; note that some compilers may pad
 * "struct fddi_header" to a multiple of 4 bytes, for example, so
 * "sizeof (struct fddi_header)" may not give the right
 * answer.
 */
#define FDDI_HDRLEN 13

/* Useful values for fddi_fc (frame control) field */

/*
 * FDDI Frame Control bits
 */
#define	FDDIFC_C		0x80		/* Class bit */
#define	FDDIFC_L		0x40		/* Address length bit */
#define	FDDIFC_F		0x30		/* Frame format bits */
#define	FDDIFC_Z		0x0f		/* Control bits */

/*
 * FDDI Frame Control values. (48-bit addressing only).
 */
#define	FDDIFC_VOID		0x40		/* Void frame */
#define	FDDIFC_NRT		0x80		/* Nonrestricted token */
#define	FDDIFC_RT		0xc0		/* Restricted token */
#define	FDDIFC_SMT_INFO		0x41		/* SMT Info */
#define	FDDIFC_SMT_NSA		0x4F		/* SMT Next station adrs */
#define	FDDIFC_MAC_BEACON	0xc2		/* MAC Beacon frame */
#define	FDDIFC_MAC_CLAIM	0xc3		/* MAC Claim frame */
#define	FDDIFC_LLC_ASYNC	0x50		/* Async. LLC frame */
#define	FDDIFC_LLC_SYNC		0xd0		/* Sync. LLC frame */
#define	FDDIFC_IMP_ASYNC	0x60		/* Implementor Async. */
#define	FDDIFC_IMP_SYNC		0xe0		/* Implementor Synch. */
#define FDDIFC_SMT		0x40		/* SMT frame */
#define FDDIFC_MAC		0xc0		/* MAC frame */

#define	FDDIFC_CLFF		0xF0		/* Class/Length/Format bits */
#define	FDDIFC_ZZZZ		0x0F		/* Control bits */

/*
 * Some FDDI interfaces use bit-swapped addresses.
 */
#if defined(ultrix) || defined(__alpha) || defined(__bsdi) || defined(__NetBSD__) || defined(__linux__)
static int fddi_bitswap = 0;
#else
static int fddi_bitswap = 1;
#endif

/*
 * FDDI support for tcpdump, by Jeffrey Mogul [DECWRL], June 1992
 *
 * Based in part on code by Van Jacobson, which bears this note:
 *
 * NOTE:  This is a very preliminary hack for FDDI support.
 * There are all sorts of wired in constants & nothing (yet)
 * to print SMT packets as anything other than hex dumps.
 * Most of the necessary changes are waiting on my redoing
 * the "header" that a kernel fddi driver supplies to bpf:  I
 * want it to look like one byte of 'direction' (0 or 1
 * depending on whether the packet was inbound or outbound),
 * two bytes of system/driver dependent data (anything an
 * implementor thinks would be useful to filter on and/or
 * save per-packet, then the real 21-byte FDDI header.
 * Steve McCanne & I have also talked about adding the
 * 'direction' byte to all bpf headers (e.g., in the two
 * bytes of padding on an ethernet header).  It's not clear
 * we could do this in a backwards compatible way & we h