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 __RCSID("$NetBSD: print-mpls.c,v 1.5 2015/03/31 21:59:35 christos Exp $"); 32 #endif 33 34 #define NETDISSECT_REWORKED 35 #ifdef HAVE_CONFIG_H 36 #include "config.h" 37 #endif 38 39 #include <tcpdump-stdinc.h> 40 41 #include "interface.h" 42 #include "extract.h" /* must come after interface.h */ 43 #include "mpls.h" 44 45 static const char *mpls_labelname[] = { 46 /*0*/ "IPv4 explicit NULL", "router alert", "IPv6 explicit NULL", 47 "implicit NULL", "rsvd", 48 /*5*/ "rsvd", "rsvd", "rsvd", "rsvd", "rsvd", 49 /*10*/ "rsvd", "rsvd", "rsvd", "rsvd", "rsvd", 50 /*15*/ "rsvd", 51 }; 52 53 enum mpls_packet_type { 54 PT_UNKNOWN, 55 PT_IPV4, 56 PT_IPV6, 57 PT_OSI 58 }; 59 60 /* 61 * RFC3032: MPLS label stack encoding 62 */ 63 void 64 mpls_print(netdissect_options *ndo, const u_char *bp, u_int length) 65 { 66 const u_char *p; 67 uint32_t label_entry; 68 uint16_t label_stack_depth = 0; 69 enum mpls_packet_type pt = PT_UNKNOWN; 70 71 p = bp; 72 ND_PRINT((ndo, "MPLS")); 73 do { 74 ND_TCHECK2(*p, sizeof(label_entry)); 75 label_entry = EXTRACT_32BITS(p); 76 ND_PRINT((ndo, "%s(label %u", 77 (label_stack_depth && ndo->ndo_vflag) ? "\n\t" : " ", 78 MPLS_LABEL(label_entry))); 79 label_stack_depth++; 80 if (ndo->ndo_vflag && 81 MPLS_LABEL(label_entry) < sizeof(mpls_labelname) / sizeof(mpls_labelname[0])) 82 ND_PRINT((ndo, " (%s)", mpls_labelname[MPLS_LABEL(label_entry)])); 83 ND_PRINT((ndo, ", exp %u", MPLS_EXP(label_entry))); 84 if (MPLS_STACK(label_entry)) 85 ND_PRINT((ndo, ", [S]")); 86 ND_PRINT((ndo, ", ttl %u)", MPLS_TTL(label_entry))); 87 88 p += sizeof(label_entry); 89 } while (!MPLS_STACK(label_entry)); 90 91 /* 92 * Try to figure out the packet type. 93 */ 94 switch (MPLS_LABEL(label_entry)) { 95 96 case 0: /* IPv4 explicit NULL label */ 97 case 3: /* IPv4 implicit NULL label */ 98 pt = PT_IPV4; 99 break; 100 101 case 2: /* IPv6 explicit NULL label */ 102 pt = PT_IPV6; 103 break; 104 105 default: 106 /* 107 * Generally there's no indication of protocol in MPLS label 108 * encoding. 109 * 110 * However, draft-hsmit-isis-aal5mux-00.txt describes a 111 * technique for encapsulating IS-IS and IP traffic on the 112 * same ATM virtual circuit; you look at the first payload 113 * byte to determine the network layer protocol, based on 114 * the fact that 115 * 116 * 1) the first byte of an IP header is 0x45-0x4f 117 * for IPv4 and 0x60-0x6f for IPv6; 118 * 119 * 2) the first byte of an OSI CLNP packet is 0x81, 120 * the first byte of an OSI ES-IS packet is 0x82, 121 * and the first byte of an OSI IS-IS packet is 122 * 0x83; 123 * 124 * so the network layer protocol can be inferred from the 125 * first byte of the packet, if the protocol is one of the 126 * ones listed above. 127 * 128 * Cisco sends control-plane traffic MPLS-encapsulated in 129 * this fashion. 130 */ 131 switch(*p) { 132 133 case 0x45: 134 case 0x46: 135 case 0x47: 136 case 0x48: 137 case 0x49: 138 case 0x4a: 139 case 0x4b: 140 case 0x4c: 141 case 0x4d: 142 case 0x4e: 143 case 0x4f: 144 pt = PT_IPV4; 145 break; 146 147 case 0x60: 148 case 0x61: 149 case 0x62: 150 case 0x63: 151 case 0x64: 152 case 0x65: 153 case 0x66: 154 case 0x67: 155 case 0x68: 156 case 0x69: 157 case 0x6a: 158 case 0x6b: 159 case 0x6c: 160 case 0x6d: 161 case 0x6e: 162 case 0x6f: 163 pt = PT_IPV6; 164 break; 165 166 case 0x81: 167 case 0x82: 168 case 0x83: 169 pt = PT_OSI; 170 break; 171 172 default: 173 /* ok bail out - we did not figure out what it is*/ 174 break; 175 } 176 } 177 178 /* 179 * Print the payload. 180 */ 181 if (pt == PT_UNKNOWN) { 182 if (!ndo->ndo_suppress_default_print) 183 ND_DEFAULTPRINT(p, length - (p - bp)); 184 return; 185 } 186 ND_PRINT((ndo, ndo->ndo_vflag ? "\n\t" : " ")); 187 switch (pt) { 188 189 case PT_IPV4: 190 ip_print(ndo, p, length - (p - bp)); 191 break; 192 193 case PT_IPV6: 194 ip6_print(ndo, p, length - (p - bp)); 195 break; 196 197 case PT_OSI: 198 isoclns_print(ndo, p, length - (p - bp), length - (p - bp)); 199 break; 200 201 default: 202 break; 203 } 204 return; 205 206 trunc: 207 ND_PRINT((ndo, "[|MPLS]")); 208 } 209 210 211 /* 212 * Local Variables: 213 * c-style: whitesmith 214 * c-basic-offset: 8 215 * End: 216 */ 217