_fr.c

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

/*
 * Copyright (c) 1990, 1991, 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.
 */

#if 0
static char rcsid[] =
"@(#)$Header: /home/ncvs/src/contrib/tcpdump/print-fr.c,v 1.2 1998/01/01 04:13:43 pst Exp $ (LBL)";
#endif

#include <stdio.h>
#include <ctype.h>
#include <signal.h>

#include <sys/param.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <sys/ioctl.h>

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

#include <netdb.h>
#include <pcap.h>

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

#ifdef PPP

#define FR_EA_BIT(p) ((p)&0x1)
#define FR_DLCI(b0,b1) ((((b0)&0xFC)<<2)+(((b1)&0xF0)>>4))

void q933_print (const u_char * p, int length);

struct fr_nlpids {
       u_short id;
       char   *name;
     };

/* find out how many bytes are there in a frame
 */
int fr_addr_len (const u_char * p)
{
  int i = 0;

  while (!FR_EA_BIT (p[i]) && i++ && !FR_EA_BIT (p[i + 1]))
    i++;
  return (i + 1);
}

/* the following is for framerelay
 */
#define NLPID_LEN        1      /* NLPID is one byte long */
#define NLPID_Q933      0x08
#define NLPID_CLNP      0x81
#define NLPID_ESIS      0x82
#define NLPID_ISIS      0x83
#define NLPID_CONS      0x84
#define NLPID_IDRP      0x85
#define NLPID_X25_ESIS  0x8a
#define NLPID_IP        0xcc


static struct fr_nlpids fr_nlpids[256];
static                  fr_nlpid_flag = 0;

void init_fr_nlpids (void)
{
  int i;

  if (!fr_nlpid_flag)
  {
    for (i = 0; i < 256; i++)
    {
      fr_nlpids[i].id = 0;
      fr_nlpids[i].name = "Not Specified";
    }
    fr_nlpids[NLPID_Q933].name = "Q.933";
    fr_nlpids[NLPID_CLNP].name = "CLNP";
    fr_nlpids[NLPID_ESIS].name = "ESIS";
    fr_nlpids[NLPID_ISIS].name = "ISIS";
    fr_nlpids[NLPID_CONS].name = "CONS";
    fr_nlpids[NLPID_IDRP].name = "IDRP";
    fr_nlpids[NLPID_X25_ESIS].name = "X25_ESIS";
    fr_nlpids[NLPID_IP].name = "IP";
  }
  fr_nlpid_flag = 1;
}

/* Framerelay packet structure */

/*
 * +---------------------------+
 * |    flag (7E hexadecimal)  |
 * +---------------------------+
 * |       Q.922 Address*      |
 * +--                       --+
 * |                           |
 * +---------------------------+
 * | Control (UI = 0x03)       |
 * +---------------------------+
 * | Optional Pad      (0x00)  |
 * +---------------------------+
 * | NLPID                     |
 * +---------------------------+
 * |             .             |
 * |             .             |
 * |             .             |
 * |           Data            |
 * |             .             |
 * |             .             |
 * +---------------------------+
 * |   Frame Check Sequence    |
 * +--           .           --+
 * |       (two octets)        |
 * +---------------------------+
 * |   flag (7E hexadecimal)   |
 * +---------------------------+
 * 
 * * Q.922 addresses, as presently defined, are two octets and
 * contain a 10-bit DLCI.  In some networks Q.922 addresses
 * may optionally be increased to three or four octets.
 * 
 */

#define FR_PROTOCOL(p) fr_protocol((p))

int fr_hdrlen (const u_char * p)
{
  int hlen = fr_addr_len (p) + 1;    /* addr_len + 0x03 + padding */
  if (p[hlen])
    return hlen;
  return hlen + 1;
}

#define LAYER2_LEN(p) (fr_hdrlen((p))+NLPID_LEN)

int fr_protocol (const u_char * p)
{
  int hlen = fr_addr_len (p) + 1;

  if (p[hlen])                  /* check for padding */
    return p[hlen];
  return p[hlen + 1];
}

void fr_hdlc_print (const u_char * p, int length)
{
  int proto, i, hlen;

  proto = FR_PROTOCOL (p);

  init_fr_nlpids();

  /* this is kinda kludge since it assumed that DLCI is two bytes.
   */
  PRINTF ("%4d %02x%02x=DLCI(%d) ", length, p[0], p[1], FR_DLCI (p[0], p[1]));
  PRINTF ("%02x %6s: ", proto, fr_nlpids[proto].name);
}


void fr_if_print (u_char * user, const struct pcap_pkthdr *h, const u_char * p)
{
  u_int length = h->len;
  u_int caplen = h->caplen;
  int   frame_relay = 0, proto = FR_PROTOCOL (p);

  ts_print (&h->ts);

  if (caplen < fr_hdrlen (p))
  {
    PUTS ("[|fr]");
    goto out;
  }

  /*
   * 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.
   */
  packetp = p;
  snapend = p + caplen;

  if (eflag)
    fr_hdlc_print (p, length);

  length = length - (fr_hdrlen (p) + NLPID_LEN);

  switch (FR_PROTOCOL (p))
  {
    case NLPID_IP:
    case ETHERTYPE_IP:
         ip_print ((const u_char *) (p + LAYER2_LEN (p)), length);
         break;
    case NLPID_CLNP:
    case NLPID_ESIS:
    case NLPID_ISIS:
         isoclns_print ((const u_char *) (p + LAYER2_LEN (p)),
                        length, caplen, "000000", "000000");
         break;
    case NLPID_Q933:
         q933_print ((const u_char *) (p + LAYER2_LEN (p)), length);
         break;
    default:
         if (!eflag)
           fr_hdlc_print (p, length);
         if (!xflag)
        default_print ((const u_char *) (p + LAYER2_LEN (p)),
                       caplen - LAYER2_LEN (p));
  }

  if (xflag)
     default_print ((const u_char *) (p + LAYER2_LEN (p)),
                    caplen - LAYER2_LEN (p));
out:
  PUTCHAR ('\n');
}

#else  /* PPP */

void fr_if_print (u_char * user, const struct pcap_pkthdr *h, const u_char * p)
{
  error ("not configured for ppp");
}
#endif

/*
 * Q.933 decoding portion for framerelay specific.
 */

/* Q.933 packet format
 * Format of Other Protocols   
 * using Q.933 NLPID
 * +-------------------------------+            
 * |        Q.922 Address          | 
 * +---------------+---------------+
 * |Control  0x03  | NLPID   0x08  |        
 * +---------------+---------------+        
 * |          L2 Protocol ID       |
 * | octet 1       |  octet 2      |
 * +-------------------------------+
 * |          L3 Protocol ID       |
 * | octet 2       |  octet 2      |
 * +-------------------------------+
 * |         Protocol Data         |
 * +-------------------------------+
 * | FCS                           |
 * +-------------------------------+
 */

/* L2 (Octet 1)- Call Reference Usually is 0x0 */

/*
 * L2 (Octet 2)- Message Types definition 1 byte long.
 */

/* Call Establish */
#define MSG_TYPE_ESC_TO_NATIONAL  0x00
#define MSG_TYPE_ALERT            0x01
#define MSG_TYPE_CALL_PROCEEDING  0x02
#define MSG_TYPE_CONNECT          0x07
#define MSG_TYPE_CONNECT_ACK      0x0F
#define MSG_TYPE_PROGRESS         0x03
#define MSG_TYPE_SETUP            0x05

/* Call Clear */
#define MSG_TYPE_DISCONNECT       0x45
#define MSG_TYPE_RELEASE          0x4D
#define MSG_TYPE_RELEASE_COMPLETE 0x5A
#define MSG_TYPE_RESTART          0x46
#define MSG_TYPE_RESTART_ACK      0x4E

/* Status */
#define MSG_TYPE_STATUS           0x7D
#define MSG_TYPE_STATUS_ENQ       0x75

#define ONE_BYTE_IE_MASK 0xF0

/* See L2 protocol ID picture above */
struct q933_header
{
  u_char call_ref;              /* usually is 0 for framerelay PVC */
  u_char msg_type;
};

#define REPORT_TYPE_IE    0x01
#define LINK_VERIFY_IE_91 0x19
#define LINK_VERIFY_IE_94 0x03
#define PVC_STATUS_IE     0x07

#define MAX_IE_SIZE

struct common_ie_header
{
  u_char ie_id;
  u_char ie_len;
};

#define FULL_STATUS 0
#define LINK_VERIFY 1
#define ASYNC_PVC   2


void q933_print (const u_char * p, int length)
{
  struct q933_header      *header = (struct q933_header *) (p + 1);
  struct common_ie_header *ie_p;
  const  u_char *ptemp = p;
  int    ie_len;
  char  *decode_str, temp_str[255];

  /* printing out header part */
  PRINTF ("Call Ref: %02x, MSG Type: %02x",
          header->call_ref, header->msg_type);

  switch (header->msg_type)
  {
    case MSG_TYPE_STATUS:
         decode_str = "STATUS REPLY";
         break;
    case MSG_TYPE_STATUS_ENQ:
         decode_str = "STATUS ENQUIRY";
         break;
    default:
         decode_str = "UNKNOWN MSG Type";
  }
  PRINTF (" %s\n", decode_str);

  length = length - 3;
  ptemp = ptemp + 3;

  /* Loop through the rest of IE */
  while (length > 0)
  {
    if (ptemp[0] & ONE_BYTE_IE_MASK)
    {
      ie_len = 1;
      PRINTF ("\t\tOne byte IE: %02x, Content %02x\n",
              (*ptemp & 0x70) >> 4, (*ptemp & 0x0F));
      length--;
      ptemp++;
    }
    else          /* Multi-byte IE */
    {         
      ie_p = (struct common_ie_header *) ptemp;
      switch (ie_p->ie_id)
      {
        case REPORT_TYPE_IE:
             switch (ptemp[2])
             {
               case FULL_STATUS:
                    decode_str = "FULL STATUS";
                    break;
               case LINK_VERIFY:
                    decode_str = "LINK VERIFY";
                    break;
               case ASYNC_PVC:
                    decode_str = "Async PVC Status";
                    break;
               default:
                    decode_str = "Reserved Value";
             }
             break;

        case LINK_VERIFY_IE_91:
        case LINK_VERIFY_IE_94:
             sprintf (temp_str, "TX Seq: %3d, RX Seq: %3d",
                      ptemp[2], ptemp[3]);
             decode_str = temp_str;
             break;

        case PVC_STATUS_IE:
             sprintf (temp_str, "DLCI %d: status %s %s",
                      ((ptemp[2] & 0x3f) << 4) + ((ptemp[3] & 0x78) >> 3),
                      ptemp[4] & 0x8 ? "new," : " ",
                      ptemp[4] & 0x2 ? "Active" : "Inactive");
             break;

        default:
             decode_str = "Non-decoded Value";
      }

      PRINTF ("\t\tIE: %02X Len: %d, %s\n",
              ie_p->ie_id, ie_p->ie_len, decode_str);
      length = length - ie_p->ie_len - 2;
      ptemp = ptemp + ie_p->ie_len + 2;
    }
  }
}