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 1.14 2005-07-05 09:38:19 hannes 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 #include "mpls.h" 48 49 static const char *mpls_labelname[] = { 50 /*0*/ "IPv4 explicit NULL", "router alert", "IPv6 explicit NULL", 51 "implicit NULL", "rsvd", 52 /*5*/ "rsvd", "rsvd", "rsvd", "rsvd", "rsvd", 53 /*10*/ "rsvd", "rsvd", "rsvd", "rsvd", "rsvd", 54 /*15*/ "rsvd", 55 }; 56 57 /* 58 * RFC3032: MPLS label stack encoding 59 */ 60 void 61 mpls_print(const u_char *bp, u_int length) 62 { 63 const u_char *p; 64 u_int32_t label_entry; 65 u_int16_t label_stack_depth = 0; 66 67 p = bp; 68 printf("MPLS"); 69 do { 70 TCHECK2(*p, sizeof(label_entry)); 71 label_entry = EXTRACT_32BITS(p); 72 printf("%s(label %u", 73 label_stack_depth ? "\n\t" : " ", 74 MPLS_LABEL(label_entry)); 75 label_stack_depth++; 76 if (vflag && 77 MPLS_LABEL(label_entry) < sizeof(mpls_labelname) / sizeof(mpls_labelname[0])) 78 printf(" (%s)", mpls_labelname[MPLS_LABEL(label_entry)]); 79 printf(", exp %u", MPLS_EXP(label_entry)); 80 if (MPLS_STACK(label_entry)) 81 printf(", [S]"); 82 printf(", ttl %u)", MPLS_TTL(label_entry)); 83 84 p += sizeof(label_entry); 85 } while (!MPLS_STACK(label_entry)); 86 87 switch (MPLS_LABEL(label_entry)) { 88 case 0: /* IPv4 explicit NULL label */ 89 case 3: /* IPv4 implicit NULL label */ 90 if (vflag>0) { 91 printf("\n\t"); 92 ip_print(gndo, p, length - (p - bp)); 93 } 94 else printf(", IP, length: %u",length); 95 break; 96 #ifdef INET6 97 case 2: /* IPv6 explicit NULL label */ 98 if (vflag>0) { 99 printf("\n\t"); 100 ip6_print(p, length - (p - bp)); 101 } 102 else printf(", IPv6, length: %u",length); 103 break; 104 #endif 105 default: 106 /* 107 * Generally there's no indication of protocol in MPLS label 108 * encoding, however draft-hsmit-isis-aal5mux-00.txt describes 109 * a technique that looks at the first payload byte if the BOS (bottom of stack) 110 * bit is set and tries to determine the network layer protocol 111 * 0x45-0x4f is IPv4 112 * 0x60-0x6f is IPv6 113 * 0x81-0x83 is OSI (CLNP,ES-IS,IS-IS) 114 * this technique is sometimes known as NULL encapsulation 115 * and decoding is particularly useful for control-plane traffic [BGP] 116 * which cisco by default sends MPLS encapsulated 117 */ 118 119 if (MPLS_STACK(label_entry)) { /* only do this if the stack bit is set */ 120 switch(*p) { 121 case 0x45: 122 case 0x46: 123 case 0x47: 124 case 0x48: 125 case 0x49: 126 case 0x4a: 127 case 0x4b: 128 case 0x4c: 129 case 0x4d: 130 case 0x4e: 131 case 0x4f: 132 if (vflag>0) { 133 printf("\n\t"); 134 ip_print(gndo, p, length - (p - bp)); 135 } 136 else printf(", IP, length: %u",length); 137 break; 138 #ifdef INET6 139 case 0x60: 140 case 0x61: 141 case 0x62: 142 case 0x63: 143 case 0x64: 144 case 0x65: 145 case 0x66: 146 case 0x67: 147 case 0x68: 148 case 0x69: 149 case 0x6a: 150 case 0x6b: 151 case 0x6c: 152 case 0x6d: 153 case 0x6e: 154 case 0x6f: 155 if (vflag>0) { 156 printf("\n\t"); 157 ip6_print(p, length - (p - bp)); 158 } 159 else printf(", IPv6, length: %u",length); 160 break; 161 #endif 162 case 0x81: 163 case 0x82: 164 case 0x83: 165 if (vflag>0) { 166 printf("\n\t"); 167 isoclns_print(p, length - (p - bp), length - (p - bp)); 168 } 169 else printf(", OSI, length: %u",length); 170 break; 171 default: 172 /* ok bail out - we did not figure out what it is*/ 173 break; 174 } 175 } 176 return; 177 } 178 179 trunc: 180 printf("[|MPLS]"); 181 } 182 183 184 /* 185 * Local Variables: 186 * c-style: whitesmith 187 * c-basic-offset: 8 188 * End: 189 */ 190