/*
* 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.
*/
/*
* 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 */
/*
* 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 hate
* the idea of an incompatible bpf change. Discussions are
* proceeding.
*
* Also, to really support FDDI (and better support 802.2
* over ethernet) we really need to re-think the rather simple
* minded assumptions about fixed length & fixed format link
* level headers made in gencode.c. One day...
*
* - vj
*/
if (fddi_bitswap) {
/*
* bit-swap the fddi addresses (isn't the IEEE standards
* process wonderful!) then convert them to names.
*/
for (i = 0; i < 6; ++i)
fdst[i] = fddi_bit_swap[fddip->fddi_dhost[i]];
for (i = 0; i < 6; ++i)
fsrc[i] = fddi_bit_swap[fddip->fddi_shost[i]];
} else {
memcpy(fdst, (const char *)fddip->fddi_dhost, 6);
memcpy(fsrc, (const char *)fddip->fddi_shost, 6);
}
}
/* Skip over FDDI MAC header */
length -= FDDI_HDRLEN;
p += FDDI_HDRLEN;
caplen -= FDDI_HDRLEN;
/* Frame Control field determines interpretation of packet */
if ((fc & FDDIFC_CLFF) == FDDIFC_LLC_ASYNC) {
/* Try to print the LLC-layer header & higher layers */
llc_hdrlen = llc_print(ndo, p, length, caplen, &src, &dst);
if (llc_hdrlen < 0) {
/*
* Some kinds of LLC packet we cannot
* handle intelligently
*/
if (!ndo->ndo_suppress_default_print)
ND_DEFAULTPRINT(p, caplen);
llc_hdrlen = -llc_hdrlen;
}
} else if ((fc & FDDIFC_CLFF) == FDDIFC_SMT) {
fddi_smt_print(ndo, p, caplen);
llc_hdrlen = 0;
} else {
/* Some kinds of FDDI packet we cannot handle intelligently */
if (!ndo->ndo_eflag)
fddi_hdr_print(ndo, fddip, length + FDDI_HDRLEN, srcmac,
dstmac);
if (!ndo->ndo_suppress_default_print)
ND_DEFAULTPRINT(p, caplen);
llc_hdrlen = 0;
}
return (FDDI_HDRLEN + llc_hdrlen);
}
/*
* This is the top level routine of the printer. 'p' points
* to the FDDI header of the packet, 'h->ts' is the timestamp,
* 'h->len' is the length of the packet off the wire, and 'h->caplen'
* is the number of bytes actually captured.
*/
void
fddi_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h, const u_char *p)
{
ndo->ndo_protocol = "fddi";
ndo->ndo_ll_hdr_len += fddi_print(ndo, p, h->len, h->caplen);
}
