contrib/tcpdump-3.8.3/print-mpls.c

   1 /*
   2  * Copyright (C) 2001 WIDE Project.  All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  * 3. Neither the name of the project nor the names of its contributors
  13  *    may be used to endorse or promote products derived from this software
  14  *    without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  */
  28
  29 #ifndef lint
  30 static const char rcsid[] _U_ =
  31     "@(#) $Header: /tcpdump/master/tcpdump/print-mpls.c,v 1.8.2.2 2003/11/16 08:51:34 guy Exp $ (LBL)";
  32 #endif
  33
  34 #ifdef HAVE_CONFIG_H
  35 #include "config.h"
  36 #endif
  37
  38 #include <tcpdump-stdinc.h>
  39
  40 #include <stdio.h>
  41 #include <stdlib.h>
  42 #include <string.h>
  43
  44 #include "addrtoname.h"
  45 #include "interface.h"
  46 #include "extract.h"                    /* must come after interface.h */
  47
  48 #define LABEL_MASK      0xfffff000
  49 #define LABEL_SHIFT     12
  50 #define EXP_MASK        0x00000e00
  51 #define EXP_SHIFT       9
  52 #define STACK_MASK      0x00000100
  53 #define STACK_SHIFT     8
  54 #define TTL_MASK        0x000000ff
  55 #define TTL_SHIFT       0
  56
  57 #define MPLS_LABEL(x)   (((x) & LABEL_MASK) >> LABEL_SHIFT)
  58 #define MPLS_EXP(x)     (((x) & EXP_MASK) >> EXP_SHIFT)
  59 #define MPLS_STACK(x)   (((x) & STACK_MASK) >> STACK_SHIFT)
  60 #define MPLS_TTL(x)     (((x) & TTL_MASK) >> TTL_SHIFT)
  61
  62 static const char *mpls_labelname[] = {
  63 /*0*/   "IPv4 explicit NULL", "router alert", "IPv6 explicit NULL",
  64         "implicit NULL", "rsvd",
  65 /*5*/   "rsvd", "rsvd", "rsvd", "rsvd", "rsvd",
  66 /*10*/  "rsvd", "rsvd", "rsvd", "rsvd", "rsvd",
  67 /*15*/  "rsvd",
  68 };
  69
  70 /*
  71  * RFC3032: MPLS label stack encoding
  72  */
  73 void
  74 mpls_print(const u_char *bp, u_int length)
  75 {
  76         const u_char *p;
  77         u_int32_t v;
  78
  79         p = bp;
  80         printf("MPLS");
  81         do {
  82                 TCHECK2(*p, sizeof(v));
  83                 v = EXTRACT_32BITS(p);
  84                 printf(" (");   /*)*/
  85                 printf("label %u", MPLS_LABEL(v));
  86                 if (vflag &&
  87                     MPLS_LABEL(v) < sizeof(mpls_labelname) / sizeof(mpls_labelname[0]))
  88                         printf(" (%s)", mpls_labelname[MPLS_LABEL(v)]);
  89                 printf(", exp %u", MPLS_EXP(v));
  90                 if (MPLS_STACK(v))
  91                         printf(", [S]");
  92                 printf(", ttl %u", MPLS_TTL(v));
  93                 /*(*/
  94                 printf(")");
  95
  96                 p += sizeof(v);
  97         } while (!MPLS_STACK(v));
  98
  99         switch (MPLS_LABEL(v)) {
 100         case 0: /* IPv4 explicit NULL label */
 101         case 3: /* IPv4 implicit NULL label */
 102                 ip_print(p, length - (p - bp));
 103                 break;
 104 #ifdef INET6
 105         case 2: /* IPv6 explicit NULL label */
 106                 ip6_print(p, length - (p - bp));
 107                 break;
 108 #endif
 109         default:
 110                 /*
 111                  * Generally there's no indication of protocol in MPLS label
 112                  * encoding, however draft-hsmit-isis-aal5mux-00.txt describes
 113                  * a technique that looks at the first payload byte if the BOS (bottom of stack)
 114                  * bit is set and tries to determine the network layer protocol
 115                  * 0x45-0x4f is IPv4
 116                  * 0x60-0x6f is IPv6
 117                  * 0x81-0x83 is OSI (CLNP,ES-IS,IS-IS)
 118                  * this technique is sometimes known as NULL encapsulation
 119                  * and decoding is particularly useful for control-plane traffic [BGP]
 120                  * which cisco by default sends MPLS encapsulated
 121                  */
 122
 123                 if (MPLS_STACK(v)) { /* only do this if the stack bit is set */
 124                     switch(*p) {
 125                     case 0x45:
 126                     case 0x46:
 127                     case 0x47:
 128                     case 0x48:
 129                     case 0x49:
 130                     case 0x4a:
 131                     case 0x4b:
 132                     case 0x4c:
 133                     case 0x4d:
 134                     case 0x4e:
 135                     case 0x4f:
 136                         if (vflag>0) {
 137                             printf("\n\t");
 138                             ip_print(p, length - (p - bp));
 139                             }
 140                         else printf(", IP, length: %u",length);
 141                         break;
 142 #ifdef INET6
 143                     case 0x60:
 144                     case 0x61:
 145                     case 0x62:
 146                     case 0x63:
 147                     case 0x64:
 148                     case 0x65:
 149                     case 0x66:
 150                     case 0x67:
 151                     case 0x68:
 152                     case 0x69:
 153                     case 0x6a:
 154                     case 0x6b:
 155                     case 0x6c:
 156                     case 0x6d:
 157                     case 0x6e:
 158                     case 0x6f:
 159                         if (vflag>0) {
 160                             printf("\n\t");
 161                             ip6_print(p, length - (p - bp));
 162                             }
 163                         else printf(", IPv6, length: %u",length);
 164                         break;
 165 #endif
 166                     case 0x81:
 167                     case 0x82:
 168                     case 0x83:
 169                         if (vflag>0) {
 170                             printf("\n\t");
 171                             isoclns_print(p, length - (p - bp), length - (p - bp));
 172                             }
 173                         else printf(", OSI, length: %u",length);
 174                         break;
 175                     default:
 176                         /* ok bail out - we did not figure out what it is*/
 177                         break;
 178                     }
 179                 }
 180                 return;
 181         }
 182
 183 trunc:
 184         printf("[|MPLS]");
 185 }
 186
 187 /*
 188  * draft-ietf-mpls-lsp-ping-02.txt
 189  */
 190 void
 191 mpls_lsp_ping_print(const u_char *pptr, u_int length)
 192 {
 193     printf("UDP, LSP-PING, length: %u", length);
 194     if (vflag >1)
 195         print_unknown_data(pptr,"\n\t  ", length);
 196 }