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 1.6 2017/01/24 23:29:14 christos Exp $"); 32 #endif 33 34 #ifdef HAVE_CONFIG_H 35 #include "config.h" 36 #endif 37 38 #include <netdissect-stdinc.h> 39 40 #include "netdissect.h" 41 #include "extract.h" 42 #include "mpls.h" 43 44 static const char *mpls_labelname[] = { 45 /*0*/ "IPv4 explicit NULL", "router alert", "IPv6 explicit NULL", 46 "implicit NULL", "rsvd", 47 /*5*/ "rsvd", "rsvd", "rsvd", "rsvd", "rsvd", 48 /*10*/ "rsvd", "rsvd", "rsvd", "rsvd", "rsvd", 49 /*15*/ "rsvd", 50 }; 51 52 enum mpls_packet_type { 53 PT_UNKNOWN, 54 PT_IPV4, 55 PT_IPV6, 56 PT_OSI 57 }; 58 59 /* 60 * RFC3032: MPLS label stack encoding 61 */ 62 void 63 mpls_print(netdissect_options *ndo, const u_char *bp, u_int length) 64 { 65 const u_char *p; 66 uint32_t label_entry; 67 uint16_t label_stack_depth = 0; 68 enum mpls_packet_type pt = PT_UNKNOWN; 69 70 p = bp; 71 ND_PRINT((ndo, "MPLS")); 72 do { 73 ND_TCHECK2(*p, sizeof(label_entry)); 74 label_entry = EXTRACT_32BITS(p); 75 ND_PRINT((ndo, "%s(label %u", 76 (label_stack_depth && ndo->ndo_vflag) ? "\n\t" : " ", 77 MPLS_LABEL(label_entry))); 78 label_stack_depth++; 79 if (ndo->ndo_vflag && 80 MPLS_LABEL(label_entry) < sizeof(mpls_labelname) / sizeof(mpls_labelname[0])) 81 ND_PRINT((ndo, " (%s)", mpls_labelname[MPLS_LABEL(label_entry)])); 82 ND_PRINT((ndo, ", exp %u", MPLS_EXP(label_entry))); 83 if (MPLS_STACK(label_entry)) 84 ND_PRINT((ndo, ", [S]")); 85 ND_PRINT((ndo, ", ttl %u)", MPLS_TTL(label_entry))); 86 87 p += sizeof(label_entry); 88 } while (!MPLS_STACK(label_entry)); 89 90 /* 91 * Try to figure out the packet type. 92 */ 93 switch (MPLS_LABEL(label_entry)) { 94 95 case 0: /* IPv4 explicit NULL label */ 96 case 3: /* IPv4 implicit NULL label */ 97 pt = PT_IPV4; 98 break; 99 100 case 2: /* IPv6 explicit NULL label */ 101 pt = PT_IPV6; 102 break; 103 104 default: 105 /* 106 * Generally there's no indication of protocol in MPLS label 107 * encoding. 108 * 109 * However, draft-hsmit-isis-aal5mux-00.txt describes a 110 * technique for encapsulating IS-IS and IP traffic on the 111 * same ATM virtual circuit; you look at the first payload 112 * byte to determine the network layer protocol, based on 113 * the fact that 114 * 115 * 1) the first byte of an IP header is 0x45-0x4f 116 * for IPv4 and 0x60-0x6f for IPv6; 117 * 118 * 2) the first byte of an OSI CLNP packet is 0x81, 119 * the first byte of an OSI ES-IS packet is 0x82, 120 * and the first byte of an OSI IS-IS packet is 121 * 0x83; 122 * 123 * so the network layer protocol can be inferred from the 124 * first byte of the packet, if the protocol is one of the 125 * ones listed above. 126 * 127 * Cisco sends control-plane traffic MPLS-encapsulated in 128 * this fashion. 129 */ 130 switch(*p) { 131 132 case 0x45: 133 case 0x46: 134 case 0x47: 135 case 0x48: 136 case 0x49: 137 case 0x4a: 138 case 0x4b: 139 case 0x4c: 140 case 0x4d: 141 case 0x4e: 142 case 0x4f: 143 pt = PT_IPV4; 144 break; 145 146 case 0x60: 147 case 0x61: 148 case 0x62: 149 case 0x63: 150 case 0x64: 151 case 0x65: 152 case 0x66: 153 case 0x67: 154 case 0x68: 155 case 0x69: 156 case 0x6a: 157 case 0x6b: 158 case 0x6c: 159 case 0x6d: 160 case 0x6e: 161 case 0x6f: 162 pt = PT_IPV6; 163 break; 164 165 case 0x81: 166 case 0x82: 167 case 0x83: 168 pt = PT_OSI; 169 break; 170 171 default: 172 /* ok bail out - we did not figure out what it is*/ 173 break; 174 } 175 } 176 177 /* 178 * Print the payload. 179 */ 180 if (pt == PT_UNKNOWN) { 181 if (!ndo->ndo_suppress_default_print) 182 ND_DEFAULTPRINT(p, length - (p - bp)); 183 return; 184 } 185 ND_PRINT((ndo, ndo->ndo_vflag ? "\n\t" : " ")); 186 switch (pt) { 187 188 case PT_IPV4: 189 ip_print(ndo, p, length - (p - bp)); 190 break; 191 192 case PT_IPV6: 193 ip6_print(ndo, p, length - (p - bp)); 194 break; 195 196 case PT_OSI: 197 isoclns_print(ndo, p, length - (p - bp), length - (p - bp)); 198 break; 199 200 default: 201 break; 202 } 203 return; 204 205 trunc: 206 ND_PRINT((ndo, "[|MPLS]")); 207 } 208 209 210 /* 211 * Local Variables: 212 * c-style: whitesmith 213 * c-basic-offset: 8 214 * End: 215 */ 216