The Tcpdump Group git mirrors - tcpdump/blob - print-cdp.c

   1 /*
   2  * Copyright (c) 1992, 1993, 1994, 1995, 1996, 1997
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that: (1) source code distributions
   7  * retain the above copyright notice and this paragraph in its entirety, (2)
   8  * distributions including binary code include the above copyright notice and
   9  * this paragraph in its entirety in the documentation or other materials
  10  * provided with the distribution, and (3) all advertising materials mentioning
  11  * features or use of this software display the following acknowledgement:
  12  * ``This product includes software developed by the University of California,
  13  * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
  14  * the University nor the names of its contributors may be used to endorse
  15  * or promote products derived from this software without specific prior
  16  * written permission.
  17  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
  18  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
  19  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  20  *
  21  * Code by Gert Doering, SpaceNet GmbH, gert@space.net
  22  *
  23  * Reference documentation:
  24  *    http://www.cisco.com/univercd/cc/td/doc/product/lan/trsrb/frames.htm
  25  */
  26
  27 #ifndef lint
  28 static const char rcsid[] =
  29     "@(#) $Header: /tcpdump/master/tcpdump/print-cdp.c,v 1.5 2001-05-10 02:58:30 fenner Exp $";
  30 #endif
  31
  32 #ifdef HAVE_CONFIG_H
  33 #include "config.h"
  34 #endif
  35
  36 #include <sys/param.h>
  37 #include <sys/time.h>
  38
  39 #include <netinet/in.h>
  40
  41 #include <ctype.h>
  42 #include <netdb.h>
  43 #include <stdio.h>
  44 #include <string.h>
  45
  46 #include "interface.h"
  47 #include "addrtoname.h"
  48 #include "extract.h"                    /* must come after interface.h */
  49
  50 static void cdp_print_addr( const u_char * p, int l );
  51 static void cdp_print_prefixes( const u_char * p, int l );
  52
  53 void
  54 cdp_print(const u_char *p, u_int length, u_int caplen,
  55           const u_char *esrc, const u_char *edst)
  56 {
  57         int i;
  58         int type, len;
  59
  60         /* Cisco Discovery Protocol */
  61
  62         if ( caplen < 4 ) {
  63                 (void)printf("[|cdp]");
  64                 return;
  65         }
  66
  67         i=0;            /* CDP data starts at offset 0 */
  68         printf ("CDP v%d, ttl=%ds", p[i], p[i+1] );
  69         i+=4;           /* skip version, TTL and chksum */
  70
  71         while (i < length) {
  72             if ( i+4 > caplen ) {
  73                 printf("[|cdp]");
  74                 return;
  75             }
  76             type = (p[i]<<8) + p[i+1];
  77             len  = (p[i+2]<<8) + p[i+3];
  78
  79             if (vflag > 1)
  80                 printf( "\n\t" );
  81
  82             if ( vflag )
  83                 printf( " %02x/%02x", type, len );
  84
  85             if ( i+len > caplen ) {
  86                 printf("[|cdp]");
  87                 return;
  88             }
  89
  90             switch( type )
  91             {
  92             case 0x01:
  93                 printf( " DevID '%.*s'", len-4, p+i+4 );
  94                 break;
  95             case 0x02:
  96                 printf( " Addr" );
  97                 cdp_print_addr( p+i+4, len-4 );
  98                 break;
  99             case 0x03:
 100                 printf( " PortID '%.*s'", len-4, p+i+4 );
 101                 break;
 102             case 0x04:
 103                 printf( " CAP 0x%02x", (unsigned) p[i+7] );
 104                 break;
 105             case 0x05:
 106                 if ( vflag > 1 )
 107                     printf( " Version:\n%.*s", len-4, p+i+4 );
 108                 else
 109                     printf( " Version: (suppressed)" );
 110                 break;
 111             case 0x06:
 112                 printf( " Platform: '%.*s'", len-4, p+i+4 );
 113                 break;
 114             case 0x07:
 115                 cdp_print_prefixes( p+i+4, len-4 );
 116                 break;
 117             case 0x09:          /* guess - not documented */
 118                 printf( " VTP Management Domain: '%.*s'", len-4, p+i+4 );
 119                 break;
 120             case 0x0a:          /* guess - not documented */
 121                 printf( " Native VLAN ID: %d", (p[i+4]<<8) + p[i+4+1] - 1 );
 122                 break;
 123             case 0x0b:          /* guess - not documented */
 124                 printf( " Duplex: %s", p[i+4] ? "full": "half" );
 125                 break;
 126             default:
 127                 printf( " unknown field type %02x, len %d", type, len );
 128             }
 129
 130             /* avoid infinite loop */
 131             if (len == 0)
 132                 break;
 133             i+=len;
 134         }
 135 }
 136
 137 static void
 138 cdp_print_addr( const u_char * p, int l )
 139 {
 140         int pl, al, num;
 141         const u_char * endp = p+l;
 142
 143         num = (p[0] << 24) + (p[1]<<16) + (p[2]<<8)+ p[3];
 144         p+=4;
 145
 146         printf(" (%d): ", num );
 147
 148         while( p < endp && num >= 0) {
 149                 pl=*(p+1);
 150                 p+=2;
 151
 152                 /* special case: IPv4, protocol type=0xcc, addr. length=4 */
 153                 if ( pl == 1 && *p == 0xcc &&
 154                      p[1] == 0 && p[2] == 4 ) {
 155                         p+=3;
 156
 157                         printf( "IPv4 %d.%d.%d.%d ", p[0], p[1], p[2], p[3] );
 158                         p+=4;
 159                 } else {        /* generic case: just print raw data */
 160                         printf("pt=0x%02x, pl=%d, pb=", *(p-2), pl);
 161                         while( pl-- > 0 )
 162                                 printf( " %02x", *p++);
 163                         al=(*p << 8) + *(p+1);
 164                         printf( ", al=%d, a=", al );
 165                         p+=2;
 166                         while( al-- > 0 )
 167                                 printf( " %02x", *p++);
 168                 }
 169                 printf("  ");
 170                 num--;
 171         }
 172 }
 173
 174
 175 static void
 176 cdp_print_prefixes( const u_char * p, int l )
 177 {
 178     printf( " IPv4 Prefixes (%d):", l/5 );
 179
 180     while(l > 0) {
 181         printf( " %d.%d.%d.%d/%d", p[0], p[1], p[2], p[3], p[4] );
 182         l-=5; p+=5;
 183     }
 184 }