dist/tcpdump/print-mpls.c

   1 /*      $NetBSD$        */
   2
   3 /*
   4  * Copyright (C) 2001 WIDE Project.  All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  * 3. Neither the name of the project nor the names of its contributors
  15  *    may be used to endorse or promote products derived from this software
  16  *    without specific prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  28  * SUCH DAMAGE.
  29  */
  30
  31 #include <sys/cdefs.h>
  32 #ifndef lint
  33 #if 0
  34 static const char rcsid[] _U_ =
  35     "@(#) Header: /tcpdump/master/tcpdump/print-mpls.c,v 1.13.2.1 2005/07/05 09:39:29 hannes Exp (LBL)";
  36 #else
  37 __RCSID("$NetBSD: tcpdump2rcsid.ex,v 1.1 2001/06/25 20:09:58 itojun Exp $");
  38 #endif
  39 #endif
  40
  41 #ifdef HAVE_CONFIG_H
  42 #include "config.h"
  43 #endif
  44
  45 #include <tcpdump-stdinc.h>
  46
  47 #include <stdio.h>
  48 #include <stdlib.h>
  49 #include <string.h>
  50
  51 #include "addrtoname.h"
  52 #include "interface.h"
  53 #include "extract.h"                    /* must come after interface.h */
  54 #include "mpls.h"
  55
  56 static const char *mpls_labelname[] = {
  57 /*0*/   "IPv4 explicit NULL", "router alert", "IPv6 explicit NULL",
  58         "implicit NULL", "rsvd",
  59 /*5*/   "rsvd", "rsvd", "rsvd", "rsvd", "rsvd",
  60 /*10*/  "rsvd", "rsvd", "rsvd", "rsvd", "rsvd",
  61 /*15*/  "rsvd",
  62 };
  63
  64 /*
  65  * RFC3032: MPLS label stack encoding
  66  */
  67 void
  68 mpls_print(const u_char *bp, u_int length)
  69 {
  70         const u_char *p;
  71         u_int32_t label_entry;
  72         u_int16_t label_stack_depth = 0;
  73
  74         p = bp;
  75         printf("MPLS");
  76         do {
  77                 TCHECK2(*p, sizeof(label_entry));
  78                 label_entry = EXTRACT_32BITS(p);
  79                 printf("%s(label %u",
  80                        label_stack_depth ? "\n\t" : " ",
  81                        MPLS_LABEL(label_entry));
  82                 label_stack_depth++;
  83                 if (vflag &&
  84                     MPLS_LABEL(label_entry) < sizeof(mpls_labelname) / sizeof(mpls_labelname[0]))
  85                         printf(" (%s)", mpls_labelname[MPLS_LABEL(label_entry)]);
  86                 printf(", exp %u", MPLS_EXP(label_entry));
  87                 if (MPLS_STACK(label_entry))
  88                         printf(", [S]");
  89                 printf(", ttl %u)", MPLS_TTL(label_entry));
  90
  91                 p += sizeof(label_entry);
  92         } while (!MPLS_STACK(label_entry));
  93
  94         switch (MPLS_LABEL(label_entry)) {
  95         case 0: /* IPv4 explicit NULL label */
  96         case 3: /* IPv4 implicit NULL label */
  97                 if (vflag>0) {
  98                         printf("\n\t");
  99                         ip_print(gndo, p, length - (p - bp));
 100                 }
 101                 else printf(", IP, length: %u",length);
 102                 break;
 103 #ifdef INET6
 104         case 2: /* IPv6 explicit NULL label */
 105                 if (vflag>0) {
 106                         printf("\n\t");
 107                         ip6_print(p, length - (p - bp));
 108                 }
 109                 else printf(", IPv6, length: %u",length);
 110                 break;
 111 #endif
 112         default:
 113                 /*
 114                  * Generally there's no indication of protocol in MPLS label
 115                  * encoding, however draft-hsmit-isis-aal5mux-00.txt describes
 116                  * a technique that looks at the first payload byte if the BOS (bottom of stack)
 117                  * bit is set and tries to determine the network layer protocol
 118                  * 0x45-0x4f is IPv4
 119                  * 0x60-0x6f is IPv6
 120                  * 0x81-0x83 is OSI (CLNP,ES-IS,IS-IS)
 121                  * this technique is sometimes known as NULL encapsulation
 122                  * and decoding is particularly useful for control-plane traffic [BGP]
 123                  * which cisco by default sends MPLS encapsulated
 124                  */
 125
 126                 if (MPLS_STACK(label_entry)) { /* only do this if the stack bit is set */
 127                     switch(*p) {
 128                     case 0x45:
 129                     case 0x46:
 130                     case 0x47:
 131                     case 0x48:
 132                     case 0x49:
 133                     case 0x4a:
 134                     case 0x4b:
 135                     case 0x4c:
 136                     case 0x4d:
 137                     case 0x4e:
 138                     case 0x4f:
 139                         if (vflag>0) {
 140                             printf("\n\t");
 141                             ip_print(gndo, p, length - (p - bp));
 142                             }
 143                         else printf(", IP, length: %u",length);
 144                         break;
 145 #ifdef INET6
 146                     case 0x60:
 147                     case 0x61:
 148                     case 0x62:
 149                     case 0x63:
 150                     case 0x64:
 151                     case 0x65:
 152                     case 0x66:
 153                     case 0x67:
 154                     case 0x68:
 155                     case 0x69:
 156                     case 0x6a:
 157                     case 0x6b:
 158                     case 0x6c:
 159                     case 0x6d:
 160                     case 0x6e:
 161                     case 0x6f:
 162                         if (vflag>0) {
 163                             printf("\n\t");
 164                             ip6_print(p, length - (p - bp));
 165                             }
 166                         else printf(", IPv6, length: %u",length);
 167                         break;
 168 #endif
 169                     case 0x81:
 170                     case 0x82:
 171                     case 0x83:
 172                         if (vflag>0) {
 173                             printf("\n\t");
 174                             isoclns_print(p, length - (p - bp), length - (p - bp));
 175                             }
 176                         else printf(", OSI, length: %u",length);
 177                         break;
 178                     default:
 179                         /* ok bail out - we did not figure out what it is*/
 180                         break;
 181                     }
 182                 }
 183                 return;
 184         }
 185
 186 trunc:
 187         printf("[|MPLS]");
 188 }
 189
 190
 191 /*
 192  * Local Variables:
 193  * c-style: whitesmith
 194  * c-basic-offset: 8
 195  * End:
 196  */