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 30static 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 49static 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
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57enum 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 */ 67void 68mpls_print(const u_char *bp, u_int length) 69{ 70 const u_char *p; 71 u_int32_t label_entry;
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65 u_int16_t label_stack_depth = 0;
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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",
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73 label_stack_depth ? "\n\t" : " ",
74 MPLS_LABEL(label_entry));
75 label_stack_depth++;
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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
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95 /* 96 * Try to figure out the packet type. 97 */ |
98 switch (MPLS_LABEL(label_entry)) {
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99 |
100 case 0: /* IPv4 explicit NULL label */
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89 case 3: /* IPv4 implicit NULL label */
90 if (vflag>0) {
91 printf("\n\t");
92 ip_print(gndo, p, length - (p - bp));
93 }
94 else printf(", IP, length: %u",length);
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101 case 3: /* IPv4 implicit NULL label */ 102 pt = PT_IPV4; |
103 break;
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96#ifdef INET6
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104 |
105 case 2: /* IPv6 explicit NULL label */
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98 if (vflag>0) {
99 printf("\n\t");
100 ip6_print(p, length - (p - bp));
101 }
102 else printf(", IPv6, length: %u",length);
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106 pt = PT_IPV6; |
107 break;
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104#endif
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108 |
109 default: 110 /* 111 * Generally there's no indication of protocol in MPLS label
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108 * encoding, however draft-hsmit-isis-aal5mux-00.txt describes
109 * a technique that looks at the first payload byte if the BOS (bottom of stack)
110 * bit is set and tries to determine the network layer protocol
111 * 0x45-0x4f is IPv4
112 * 0x60-0x6f is IPv6
113 * 0x81-0x83 is OSI (CLNP,ES-IS,IS-IS)
114 * this technique is sometimes known as NULL encapsulation
115 * and decoding is particularly useful for control-plane traffic [BGP]
116 * which cisco by default sends MPLS encapsulated
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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 */
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135 switch(*p) { |
136
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119 if (MPLS_STACK(label_entry)) { /* only do this if the stack bit is set */
120 switch(*p) {
121 case 0x45:
122 case 0x46:
123 case 0x47:
124 case 0x48:
125 case 0x49:
126 case 0x4a:
127 case 0x4b:
128 case 0x4c:
129 case 0x4d:
130 case 0x4e:
131 case 0x4f:
132 if (vflag>0) {
133 printf("\n\t");
134 ip_print(gndo, p, length - (p - bp));
135 }
136 else printf(", IP, length: %u",length);
137 break;
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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
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139 case 0x60:
140 case 0x61:
141 case 0x62:
142 case 0x63:
143 case 0x64:
144 case 0x65:
145 case 0x66:
146 case 0x67:
147 case 0x68:
148 case 0x69:
149 case 0x6a:
150 case 0x6b:
151 case 0x6c:
152 case 0x6d:
153 case 0x6e:
154 case 0x6f:
155 if (vflag>0) {
156 printf("\n\t");
157 ip6_print(p, length - (p - bp));
158 }
159 else printf(", IPv6, length: %u",length);
160 break;
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202 ip6_print(gndo, p, length - (p - bp)); 203#else 204 printf("IPv6, length: %u", length); |
205#endif
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162 case 0x81:
163 case 0x82:
164 case 0x83:
165 if (vflag>0) {
166 printf("\n\t");
167 isoclns_print(p, length - (p - bp), length - (p - bp));
168 }
169 else printf(", OSI, length: %u",length);
170 break;
171 default:
172 /* ok bail out - we did not figure out what it is*/
173 break;
174 }
175 }
176 return;
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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 }
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215 return; |
216 217trunc: 218 printf("[|MPLS]"); 219} 220 221 222/* 223 * Local Variables: 224 * c-style: whitesmith 225 * c-basic-offset: 8 226 * End: 227 */
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