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 1.8.2.2 2003/11/16 08:51:34 guy 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 48 #define LABEL_MASK 0xfffff000 49 #define LABEL_SHIFT 12 50 #define EXP_MASK 0x00000e00 51 #define EXP_SHIFT 9 52 #define STACK_MASK 0x00000100 53 #define STACK_SHIFT 8 54 #define TTL_MASK 0x000000ff 55 #define TTL_SHIFT 0 56 57 #define MPLS_LABEL(x) (((x) & LABEL_MASK) >> LABEL_SHIFT) 58 #define MPLS_EXP(x) (((x) & EXP_MASK) >> EXP_SHIFT) 59 #define MPLS_STACK(x) (((x) & STACK_MASK) >> STACK_SHIFT) 60 #define MPLS_TTL(x) (((x) & TTL_MASK) >> TTL_SHIFT) 61 62 static const char *mpls_labelname[] = { 63 /*0*/ "IPv4 explicit NULL", "router alert", "IPv6 explicit NULL", 64 "implicit NULL", "rsvd", 65 /*5*/ "rsvd", "rsvd", "rsvd", "rsvd", "rsvd", 66 /*10*/ "rsvd", "rsvd", "rsvd", "rsvd", "rsvd", 67 /*15*/ "rsvd", 68 }; 69 70 /* 71 * RFC3032: MPLS label stack encoding 72 */ 73 void 74 mpls_print(const u_char *bp, u_int length) 75 { 76 const u_char *p; 77 u_int32_t v; 78 79 p = bp; 80 printf("MPLS"); 81 do { 82 TCHECK2(*p, sizeof(v)); 83 v = EXTRACT_32BITS(p); 84 printf(" ("); /*)*/ 85 printf("label %u", MPLS_LABEL(v)); 86 if (vflag && 87 MPLS_LABEL(v) < sizeof(mpls_labelname) / sizeof(mpls_labelname[0])) 88 printf(" (%s)", mpls_labelname[MPLS_LABEL(v)]); 89 printf(", exp %u", MPLS_EXP(v)); 90 if (MPLS_STACK(v)) 91 printf(", [S]"); 92 printf(", ttl %u", MPLS_TTL(v)); 93 /*(*/ 94 printf(")"); 95 96 p += sizeof(v); 97 } while (!MPLS_STACK(v)); 98 99 switch (MPLS_LABEL(v)) { 100 case 0: /* IPv4 explicit NULL label */ 101 case 3: /* IPv4 implicit NULL label */ 102 ip_print(p, length - (p - bp)); 103 break; 104 #ifdef INET6 105 case 2: /* IPv6 explicit NULL label */ 106 ip6_print(p, length - (p - bp)); 107 break; 108 #endif 109 default: 110 /* 111 * Generally there's no indication of protocol in MPLS label 112 * encoding, however draft-hsmit-isis-aal5mux-00.txt describes 113 * a technique that looks at the first payload byte if the BOS (bottom of stack) 114 * bit is set and tries to determine the network layer protocol 115 * 0x45-0x4f is IPv4 116 * 0x60-0x6f is IPv6 117 * 0x81-0x83 is OSI (CLNP,ES-IS,IS-IS) 118 * this technique is sometimes known as NULL encapsulation 119 * and decoding is particularly useful for control-plane traffic [BGP] 120 * which cisco by default sends MPLS encapsulated 121 */ 122 123 if (MPLS_STACK(v)) { /* only do this if the stack bit is set */ 124 switch(*p) { 125 case 0x45: 126 case 0x46: 127 case 0x47: 128 case 0x48: 129 case 0x49: 130 case 0x4a: 131 case 0x4b: 132 case 0x4c: 133 case 0x4d: 134 case 0x4e: 135 case 0x4f: 136 if (vflag>0) { 137 printf("\n\t"); 138 ip_print(p, length - (p - bp)); 139 } 140 else printf(", IP, length: %u",length); 141 break; 142 #ifdef INET6 143 case 0x60: 144 case 0x61: 145 case 0x62: 146 case 0x63: 147 case 0x64: 148 case 0x65: 149 case 0x66: 150 case 0x67: 151 case 0x68: 152 case 0x69: 153 case 0x6a: 154 case 0x6b: 155 case 0x6c: 156 case 0x6d: 157 case 0x6e: 158 case 0x6f: 159 if (vflag>0) { 160 printf("\n\t"); 161 ip6_print(p, length - (p - bp)); 162 } 163 else printf(", IPv6, length: %u",length); 164 break; 165 #endif 166 case 0x81: 167 case 0x82: 168 case 0x83: 169 if (vflag>0) { 170 printf("\n\t"); 171 isoclns_print(p, length - (p - bp), length - (p - bp)); 172 } 173 else printf(", OSI, length: %u",length); 174 break; 175 default: 176 /* ok bail out - we did not figure out what it is*/ 177 break; 178 } 179 } 180 return; 181 } 182 183 trunc: 184 printf("[|MPLS]"); 185 } 186 187 /* 188 * draft-ietf-mpls-lsp-ping-02.txt 189 */ 190 void 191 mpls_lsp_ping_print(const u_char *pptr, u_int length) 192 { 193 printf("UDP, LSP-PING, length: %u", length); 194 if (vflag >1) 195 print_unknown_data(pptr,"\n\t ", length); 196 } 197