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 #include <sys/cdefs.h> 30 #ifndef lint 31 #if 0 32 static const char rcsid[] _U_ = 33 "@(#) Header: /tcpdump/master/tcpdump/print-mpls.c,v 1.14 2005-07-05 09:38:19 hannes Exp (LBL)"; 34 #else 35 __RCSID("$NetBSD: print-mpls.c,v 1.3 2013/04/06 19:33:08 christos Exp $"); 36 #endif 37 #endif 38 39 #ifdef HAVE_CONFIG_H 40 #include "config.h" 41 #endif 42 43 #include <tcpdump-stdinc.h> 44 45 #include <stdio.h> 46 #include <stdlib.h> 47 #include <string.h> 48 49 #include "addrtoname.h" 50 #include "interface.h" 51 #include "extract.h" /* must come after interface.h */ 52 #include "mpls.h" 53 54 static const char *mpls_labelname[] = { 55 /*0*/ "IPv4 explicit NULL", "router alert", "IPv6 explicit NULL", 56 "implicit NULL", "rsvd", 57 /*5*/ "rsvd", "rsvd", "rsvd", "rsvd", "rsvd", 58 /*10*/ "rsvd", "rsvd", "rsvd", "rsvd", "rsvd", 59 /*15*/ "rsvd", 60 }; 61 62 enum mpls_packet_type { 63 PT_UNKNOWN, 64 PT_IPV4, 65 PT_IPV6, 66 PT_OSI 67 }; 68 69 /* 70 * RFC3032: MPLS label stack encoding 71 */ 72 void 73 mpls_print(const u_char *bp, u_int length) 74 { 75 const u_char *p; 76 u_int32_t label_entry; 77 u_int16_t label_stack_depth = 0; 78 enum mpls_packet_type pt = PT_UNKNOWN; 79 80 p = bp; 81 printf("MPLS"); 82 do { 83 TCHECK2(*p, sizeof(label_entry)); 84 label_entry = EXTRACT_32BITS(p); 85 printf("%s(label %u", 86 (label_stack_depth && vflag) ? "\n\t" : " ", 87 MPLS_LABEL(label_entry)); 88 label_stack_depth++; 89 if (vflag && 90 MPLS_LABEL(label_entry) < sizeof(mpls_labelname) / sizeof(mpls_labelname[0])) 91 printf(" (%s)", mpls_labelname[MPLS_LABEL(label_entry)]); 92 printf(", exp %u", MPLS_EXP(label_entry)); 93 if (MPLS_STACK(label_entry)) 94 printf(", [S]"); 95 printf(", ttl %u)", MPLS_TTL(label_entry)); 96 97 p += sizeof(label_entry); 98 } while (!MPLS_STACK(label_entry)); 99 100 /* 101 * Try to figure out the packet type. 102 */ 103 switch (MPLS_LABEL(label_entry)) { 104 105 case 0: /* IPv4 explicit NULL label */ 106 case 3: /* IPv4 implicit NULL label */ 107 pt = PT_IPV4; 108 break; 109 110 case 2: /* IPv6 explicit NULL label */ 111 pt = PT_IPV6; 112 break; 113 114 default: 115 /* 116 * Generally there's no indication of protocol in MPLS label 117 * encoding. 118 * 119 * However, draft-hsmit-isis-aal5mux-00.txt describes a 120 * technique for encapsulating IS-IS and IP traffic on the 121 * same ATM virtual circuit; you look at the first payload 122 * byte to determine the network layer protocol, based on 123 * the fact that 124 * 125 * 1) the first byte of an IP header is 0x45-0x4f 126 * for IPv4 and 0x60-0x6f for IPv6; 127 * 128 * 2) the first byte of an OSI CLNP packet is 0x81, 129 * the first byte of an OSI ES-IS packet is 0x82, 130 * and the first byte of an OSI IS-IS packet is 131 * 0x83; 132 * 133 * so the network layer protocol can be inferred from the 134 * first byte of the packet, if the protocol is one of the 135 * ones listed above. 136 * 137 * Cisco sends control-plane traffic MPLS-encapsulated in 138 * this fashion. 139 */ 140 switch(*p) { 141 142 case 0x45: 143 case 0x46: 144 case 0x47: 145 case 0x48: 146 case 0x49: 147 case 0x4a: 148 case 0x4b: 149 case 0x4c: 150 case 0x4d: 151 case 0x4e: 152 case 0x4f: 153 pt = PT_IPV4; 154 break; 155 156 case 0x60: 157 case 0x61: 158 case 0x62: 159 case 0x63: 160 case 0x64: 161 case 0x65: 162 case 0x66: 163 case 0x67: 164 case 0x68: 165 case 0x69: 166 case 0x6a: 167 case 0x6b: 168 case 0x6c: 169 case 0x6d: 170 case 0x6e: 171 case 0x6f: 172 pt = PT_IPV6; 173 break; 174 175 case 0x81: 176 case 0x82: 177 case 0x83: 178 pt = PT_OSI; 179 break; 180 181 default: 182 /* ok bail out - we did not figure out what it is*/ 183 break; 184 } 185 } 186 187 /* 188 * Print the payload. 189 */ 190 if (pt == PT_UNKNOWN) { 191 if (!suppress_default_print) 192 default_print(p, length - (p - bp)); 193 return; 194 } 195 if (vflag) 196 printf("\n\t"); 197 else 198 printf(" "); 199 switch (pt) { 200 201 case PT_IPV4: 202 ip_print(gndo, p, length - (p - bp)); 203 break; 204 205 case PT_IPV6: 206 #ifdef INET6 207 ip6_print(gndo, p, length - (p - bp)); 208 #else 209 printf("IPv6, length: %u", length); 210 #endif 211 break; 212 213 case PT_OSI: 214 isoclns_print(p, length - (p - bp), length - (p - bp)); 215 break; 216 217 default: 218 break; 219 } 220 return; 221 222 trunc: 223 printf("[|MPLS]"); 224 } 225 226 227 /* 228 * Local Variables: 229 * c-style: whitesmith 230 * c-basic-offset: 8 231 * End: 232 */ 233