_fddi.c

This directory contains source code for tcpdump, a tool for network monitoring and data acquisition

/* 
 * Copyright (c) 1991, 1992, 1993, 1994, 1995, 1996
 *      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.
 */

#include <stdio.h>
#include <string.h>
#include <time.h>
#include <ctype.h>
#include <sys/socket.h>

#include <net/if.h>
#include <netinet/in.h>
#include <netinet/if_ether.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netdb.h>

#include "interfac.h"
#include "a2name.h"
#include "ethertyp.h"
#include "fddi.h"

/* 
 * Some FDDI interfaces use bit-swapped addresses.
 */
int fddi_bitswap = 0;

/* 
 * 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
 */

#define FDDI_HDRLEN (sizeof(struct fddi_header))

static u_char fddi_bit_swap[] =
{
  0x00, 0x80, 0x40, 0xc0, 0x20, 0xa0, 0x60, 0xe0,
  0x10, 0x90, 0x50, 0xd0, 0x30, 0xb0, 0x70, 0xf0,
  0x08, 0x88, 0x48, 0xc8, 0x28, 0xa8, 0x68, 0xe8,
  0x18, 0x98, 0x58, 0xd8, 0x38, 0xb8, 0x78, 0xf8,
  0x04, 0x84, 0x44, 0xc4, 0x24, 0xa4, 0x64, 0xe4,
  0x14, 0x94, 0x54, 0xd4, 0x34, 0xb4, 0x74, 0xf4,
  0x0c, 0x8c, 0x4c, 0xcc, 0x2c, 0xac, 0x6c, 0xec,
  0x1c, 0x9c, 0x5c, 0xdc, 0x3c, 0xbc, 0x7c, 0xfc,
  0x02, 0x82, 0x42, 0xc2, 0x22, 0xa2, 0x62, 0xe2,
  0x12, 0x92, 0x52, 0xd2, 0x32, 0xb2, 0x72, 0xf2,
  0x0a, 0x8a, 0x4a, 0xca, 0x2a, 0xaa, 0x6a, 0xea,
  0x1a, 0x9a, 0x5a, 0xda, 0x3a, 0xba, 0x7a, 0xfa,
  0x06, 0x86, 0x46, 0xc6, 0x26, 0xa6, 0x66, 0xe6,
  0x16, 0x96, 0x56, 0xd6, 0x36, 0xb6, 0x76, 0xf6,
  0x0e, 0x8e, 0x4e, 0xce, 0x2e, 0xae, 0x6e, 0xee,
  0x1e, 0x9e, 0x5e, 0xde, 0x3e, 0xbe, 0x7e, 0xfe,
  0x01, 0x81, 0x41, 0xc1, 0x21, 0xa1, 0x61, 0xe1,
  0x11, 0x91, 0x51, 0xd1, 0x31, 0xb1, 0x71, 0xf1,
  0x09, 0x89, 0x49, 0xc9, 0x29, 0xa9, 0x69, 0xe9,
  0x19, 0x99, 0x59, 0xd9, 0x39, 0xb9, 0x79, 0xf9,
  0x05, 0x85, 0x45, 0xc5, 0x25, 0xa5, 0x65, 0xe5,
  0x15, 0x95, 0x55, 0xd5, 0x35, 0xb5, 0x75, 0xf5,
  0x0d, 0x8d, 0x4d, 0xcd, 0x2d, 0xad, 0x6d, 0xed,
  0x1d, 0x9d, 0x5d, 0xdd, 0x3d, 0xbd, 0x7d, 0xfd,
  0x03, 0x83, 0x43, 0xc3, 0x23, 0xa3, 0x63, 0xe3,
  0x13, 0x93, 0x53, 0xd3, 0x33, 0xb3, 0x73, 0xf3,
  0x0b, 0x8b, 0x4b, 0xcb, 0x2b, 0xab, 0x6b, 0xeb,
  0x1b, 0x9b, 0x5b, 0xdb, 0x3b, 0xbb, 0x7b, 0xfb,
  0x07, 0x87, 0x47, 0xc7, 0x27, 0xa7, 0x67, 0xe7,
  0x17, 0x97, 0x57, 0xd7, 0x37, 0xb7, 0x77, 0xf7,
  0x0f, 0x8f, 0x4f, 0xcf, 0x2f, 0xaf, 0x6f, 0xef,
  0x1f, 0x9f, 0x5f, 0xdf, 0x3f, 0xbf, 0x7f, 0xff,
};

/* 
 * Print FDDI frame-control bits
 */
static void print_fddi_fc (u_char fc)
{
  switch (fc)
  {
    case FDDIFC_VOID:        /* Void frame */
         PUTS ("void ");
         break;

    case FDDIFC_NRT: /* Nonrestricted token */
         PUTS ("nrt ");
         break;

    case FDDIFC_RT:          /* Restricted token */
         PUTS ("rt ");
         break;

    case FDDIFC_SMT_INFO:    /* SMT Info */
         PUTS ("info ");
         break;

    case FDDIFC_SMT_NSA:     /* SMT Next station adrs */
         PUTS ("nsa ");
         break;

    case FDDIFC_MAC_BEACON:  /* MAC Beacon frame */
         PUTS ("beacon ");
         break;

    case FDDIFC_MAC_CLAIM:   /* MAC Claim frame */
         PUTS ("claim ");
         break;

    default:
         switch (fc & FDDIFC_CLFF)
         {
           case FDDIFC_MAC:
                PRINTF ("mac%1x ", fc & FDDIFC_ZZZZ);
                break;

           case FDDIFC_SMT:
                PRINTF ("smt%1x ", fc & FDDIFC_ZZZZ);
                break;

           case FDDIFC_LLC_ASYNC:
                PRINTF ("async%1x ", fc & FDDIFC_ZZZZ);
                break;

           case FDDIFC_LLC_SYNC:
                PRINTF ("sync%1x ", fc & FDDIFC_ZZZZ);
                break;

           case FDDIFC_IMP_ASYNC:
                PRINTF ("imp_async%1x ", fc & FDDIFC_ZZZZ);
                break;

           case FDDIFC_IMP_SYNC:
                PRINTF ("imp_sync%1x ", fc & FDDIFC_ZZZZ);
                break;

           default:
                PRINTF ("%02x ", fc);
                break;
         }
  }
}

/*
 * Extract src, dst addresses
 */
static void extract_fddi_addrs (const struct fddi_header *fddip, char *fsrc, char *fdst)
{
  int i;

  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,fddip->fddi_dhost,6);
    memcpy (fsrc,fddip->fddi_shost,6);
  }
}

/* 
 * Print the FDDI MAC header
 */
static void fddi_print (const struct fddi_header *fddip, u_int length,
                        const u_char * fsrc, const u_char * fdst)
{
  char *srcname, *dstname;

  srcname = etheraddr_string (fsrc);
  dstname = etheraddr_string (fdst);

  if (vflag)
     PRINTF ("%02x %s %s %-4d: ",
             fddip->fddi_fc, srcname, dstname, length);
  else if (qflag)
       PRINTF ("%s %s %-4d: ", srcname, dstname, length);
  else
  {
    print_fddi_fc (fddip->fddi_fc);
    PRINTF ("%s %s %-4d: ", srcname, dstname, length);
  }
}

static void fddi_smt_print (const u_char *p, u_int length)
{
  PUTS ("<SMT printer not yet implemented>");
  ARGSUSED (p);
  ARGSUSED (length);
}

/* 
 * This is the top level routine of the printer.  'sp' is the points
 * to the FDDI header of the packet, 'tvp' is the timestamp,
 * 'length' is the length of the packet off the wire, and 'caplen'
 * is the number of bytes actually captured.
 */

void fddi_if_print (u_char *pcap, const struct pcap_pkthdr *h, const u_char *p)
{
  struct ether_header ehdr;
  static u_int32_t num_pkt = 0;
  u_int  caplen = h->caplen;
  u_int  length = h->len;
  const  struct  fddi_header *fddip = (struct fddi_header*) p;

  ts_print (&h->ts);

  if (caplen < FDDI_HDRLEN)
  {
    PUTS ("[|fddi]");
    goto out;
  }

  /* Get the FDDI addresses into a canonical form
   */
  extract_fddi_addrs (fddip, (char*)ESRC (&ehdr), (char*)EDST (&ehdr));

  /* Some printers want to get back at the link level addresses,
   * and/or check that they're not walking off the end of the packet.
   * Rather than pass them all the way down, we set these globals.
   */
  snapend = p + caplen;

  /* Actually, the only printer that uses packetp is print-bootp.c
   * (and print-arp.c), and it assumes that packetp points to an Ethernet
   * header.  The right thing to do is to fix print-bootp.c to know which
   * link type is in use when it excavates. XXX
   */
  packetp = (u_char*) &ehdr;

  if (eflag)
     fddi_print (fddip, length, ESRC(&ehdr), EDST(&ehdr));

  /* Skip over FDDI MAC header
   */
  length -= FDDI_HDRLEN;
  p      += FDDI_HDRLEN;
  caplen -= FDDI_HDRLEN;

  /* Frame Control field determines interpretation of packet
   */
  extracted_ethertype = 0;
  if ((fddip->fddi_fc & FDDIFC_CLFF) == FDDIFC_LLC_ASYNC)
  {
    /* Try to print the LLC-layer header & higher layers
     */
    if (llc_print (p, length, caplen, ESRC(&ehdr), EDST(&ehdr)) == 0)
    {
      /*
       * Some kinds of LLC packet we cannot
       * handle intelligently
       */
      if (!eflag)
         fddi_print (fddip, length, ESRC(&ehdr), EDST(&ehdr));
      if (extracted_ethertype)
      {
        PRINTF ("(LLC %s) ", etherproto_string(htons(extracted_ethertype)));
      }
      if (!xflag && !qflag)
         default_print (p, caplen);
    }
  }
  else if ((fddip->fddi_fc & FDDIFC_CLFF) == FDDIFC_SMT)
          fddi_smt_print (p, caplen);
  else
  {
    /* Some kinds of FDDI packet we cannot handle intelligently
     */
    if (!eflag)
       fddi_print (fddip, length, ESRC(&ehdr), EDST(&ehdr));
    if (!xflag && !qflag)
       default_print (p, caplen);
  }
  if (xflag)
     default_print (p, caplen);

  if (aflag)
     ascii_print (p, caplen);

out:
  PUTS ("\n");
  status_write ("FDDI: %lu (%lu)", ++num_pkt, pcap_mac_packets());
}