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 enum mpls_packet_type { 58 PT_UNKNOWN, 59 PT_IPV4, 60 PT_IPV6, 61 PT_OSI 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 enum mpls_packet_type pt = PT_UNKNOWN; 74 75 p = bp; 76 printf("MPLS"); 77 do { 78 TCHECK2(*p, sizeof(label_entry)); 79 label_entry = EXTRACT_32BITS(p); 80 printf("%s(label %u", 81 (label_stack_depth && vflag) ? "\n\t" : " ", 82 MPLS_LABEL(label_entry)); 83 label_stack_depth++; 84 if (vflag && 85 MPLS_LABEL(label_entry) < sizeof(mpls_labelname) / sizeof(mpls_labelname[0])) 86 printf(" (%s)", mpls_labelname[MPLS_LABEL(label_entry)]); 87 printf(", exp %u", MPLS_EXP(label_entry)); 88 if (MPLS_STACK(label_entry)) 89 printf(", [S]"); 90 printf(", ttl %u)", MPLS_TTL(label_entry)); 91 92 p += sizeof(label_entry); 93 } while (!MPLS_STACK(label_entry)); 94 95 /* 96 * Try to figure out the packet type. 97 */ 98 switch (MPLS_LABEL(label_entry)) { 99 100 case 0: /* IPv4 explicit NULL label */ 101 case 3: /* IPv4 implicit NULL label */ 102 pt = PT_IPV4; 103 break; 104 105 case 2: /* IPv6 explicit NULL label */ 106 pt = PT_IPV6; 107 break; 108 109 default: 110 /* 111 * Generally there's no indication of protocol in MPLS label 112 * encoding. 113 * 114 * However, draft-hsmit-isis-aal5mux-00.txt describes a 115 * technique for encapsulating IS-IS and IP traffic on the 116 * same ATM virtual circuit; you look at the first payload 117 * byte to determine the network layer protocol, based on 118 * the fact that 119 * 120 * 1) the first byte of an IP header is 0x45-0x4f 121 * for IPv4 and 0x60-0x6f for IPv6; 122 * 123 * 2) the first byte of an OSI CLNP packet is 0x81, 124 * the first byte of an OSI ES-IS packet is 0x82, 125 * and the first byte of an OSI IS-IS packet is 126 * 0x83; 127 * 128 * so the network layer protocol can be inferred from the 129 * first byte of the packet, if the protocol is one of the 130 * ones listed above. 131 * 132 * Cisco sends control-plane traffic MPLS-encapsulated in 133 * this fashion. 134 */ 135 switch(*p) { 136 137 case 0x45: 138 case 0x46: 139 case 0x47: 140 case 0x48: 141 case 0x49: 142 case 0x4a: 143 case 0x4b: 144 case 0x4c: 145 case 0x4d: 146 case 0x4e: 147 case 0x4f: 148 pt = PT_IPV4; 149 break; 150 151 case 0x60: 152 case 0x61: 153 case 0x62: 154 case 0x63: 155 case 0x64: 156 case 0x65: 157 case 0x66: 158 case 0x67: 159 case 0x68: 160 case 0x69: 161 case 0x6a: 162 case 0x6b: 163 case 0x6c: 164 case 0x6d: 165 case 0x6e: 166 case 0x6f: 167 pt = PT_IPV6; 168 break; 169 170 case 0x81: 171 case 0x82: 172 case 0x83: 173 pt = PT_OSI; 174 break; 175 176 default: 177 /* ok bail out - we did not figure out what it is*/ 178 break; 179 } 180 } 181 182 /* 183 * Print the payload. 184 */ 185 if (pt == PT_UNKNOWN) { 186 if (!suppress_default_print) 187 default_print(p, length - (p - bp)); 188 return; 189 } 190 if (vflag) 191 printf("\n\t"); 192 else 193 printf(" "); 194 switch (pt) { 195 196 case PT_IPV4: 197 ip_print(gndo, p, length - (p - bp)); 198 break; 199 200 case PT_IPV6: 201 #ifdef INET6 202 ip6_print(gndo, p, length - (p - bp)); 203 #else 204 printf("IPv6, length: %u", length); 205 #endif 206 break; 207 208 case PT_OSI: 209 isoclns_print(p, length - (p - bp), length - (p - bp)); 210 break; 211 212 default: 213 break; 214 } 215 return; 216 217 trunc: 218 printf("[|MPLS]"); 219 } 220 221 222 /* 223 * Local Variables: 224 * c-style: whitesmith 225 * c-basic-offset: 8 226 * End: 227 */ 228