xref: /netbsd-src/external/bsd/tcpdump/dist/print-cfm.c (revision ccd9df534e375a4366c5b55f23782053c7a98d82)
1 /*
2  * Copyright (c) 1998-2006 The TCPDUMP project
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that: (1) source code
6  * distributions retain the above copyright notice and this paragraph
7  * in its entirety, and (2) distributions including binary code include
8  * the above copyright notice and this paragraph in its entirety in
9  * the documentation or other materials provided with the distribution.
10  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND
11  * WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT
12  * LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
13  * FOR A PARTICULAR PURPOSE.
14  *
15  * Original code by Hannes Gredler (hannes@gredler.at)
16  */
17 
18 /* \summary: IEEE 802.1ag Connectivity Fault Management (CFM) protocols printer */
19 
20 #include <sys/cdefs.h>
21 #ifndef lint
22 __RCSID("$NetBSD: print-cfm.c,v 1.10 2023/08/17 20:19:40 christos Exp $");
23 #endif
24 
25 #ifdef HAVE_CONFIG_H
26 #include <config.h>
27 #endif
28 
29 #include "netdissect-stdinc.h"
30 
31 #include "netdissect.h"
32 #include "extract.h"
33 #include "addrtoname.h"
34 #include "oui.h"
35 #include "af.h"
36 
37 
38 struct cfm_common_header_t {
39     nd_uint8_t mdlevel_version;
40     nd_uint8_t opcode;
41     nd_uint8_t flags;
42     nd_uint8_t first_tlv_offset;
43 };
44 
45 #define	CFM_VERSION 0
46 #define CFM_EXTRACT_VERSION(x) ((x)&0x1f)
47 #define CFM_EXTRACT_MD_LEVEL(x) (((x)&0xe0)>>5)
48 
49 #define	CFM_OPCODE_CCM 1
50 #define	CFM_OPCODE_LBR 2
51 #define	CFM_OPCODE_LBM 3
52 #define	CFM_OPCODE_LTR 4
53 #define	CFM_OPCODE_LTM 5
54 
55 static const struct tok cfm_opcode_values[] = {
56     { CFM_OPCODE_CCM, "Continuity Check Message"},
57     { CFM_OPCODE_LBR, "Loopback Reply"},
58     { CFM_OPCODE_LBM, "Loopback Message"},
59     { CFM_OPCODE_LTR, "Linktrace Reply"},
60     { CFM_OPCODE_LTM, "Linktrace Message"},
61     { 0, NULL}
62 };
63 
64 /*
65  * Message Formats.
66  */
67 struct cfm_ccm_t {
68     nd_uint32_t sequence;
69     nd_uint16_t ma_epi;
70     nd_byte     names[48];
71     nd_byte     itu_t_y_1731[16];
72 };
73 
74 /*
75  * Timer Bases for the CCM Interval field.
76  * Expressed in units of seconds.
77  */
78 static const float ccm_interval_base[8] = {0.0f, 0.003333f, 0.01f, 0.1f, 1.0f, 10.0f, 60.0f, 600.0f};
79 #define CCM_INTERVAL_MIN_MULTIPLIER 3.25
80 #define CCM_INTERVAL_MAX_MULTIPLIER 3.5
81 
82 #define CFM_CCM_RDI_FLAG 0x80
83 #define CFM_EXTRACT_CCM_INTERVAL(x) ((x)&0x07)
84 
85 #define CFM_CCM_MD_FORMAT_8021 0
86 #define CFM_CCM_MD_FORMAT_NONE 1
87 #define CFM_CCM_MD_FORMAT_DNS  2
88 #define CFM_CCM_MD_FORMAT_MAC  3
89 #define CFM_CCM_MD_FORMAT_CHAR 4
90 
91 static const struct tok cfm_md_nameformat_values[] = {
92     { CFM_CCM_MD_FORMAT_8021, "IEEE 802.1"},
93     { CFM_CCM_MD_FORMAT_NONE, "No MD Name present"},
94     { CFM_CCM_MD_FORMAT_DNS, "DNS string"},
95     { CFM_CCM_MD_FORMAT_MAC, "MAC + 16Bit Integer"},
96     { CFM_CCM_MD_FORMAT_CHAR, "Character string"},
97     { 0, NULL}
98 };
99 
100 #define CFM_CCM_MA_FORMAT_8021 0
101 #define CFM_CCM_MA_FORMAT_VID  1
102 #define CFM_CCM_MA_FORMAT_CHAR 2
103 #define CFM_CCM_MA_FORMAT_INT  3
104 #define CFM_CCM_MA_FORMAT_VPN  4
105 
106 static const struct tok cfm_ma_nameformat_values[] = {
107     { CFM_CCM_MA_FORMAT_8021, "IEEE 802.1"},
108     { CFM_CCM_MA_FORMAT_VID, "Primary VID"},
109     { CFM_CCM_MA_FORMAT_CHAR, "Character string"},
110     { CFM_CCM_MA_FORMAT_INT, "16Bit Integer"},
111     { CFM_CCM_MA_FORMAT_VPN, "RFC2685 VPN-ID"},
112     { 0, NULL}
113 };
114 
115 struct cfm_lbm_t {
116     nd_uint32_t transaction_id;
117 };
118 
119 struct cfm_ltm_t {
120     nd_uint32_t transaction_id;
121     nd_uint8_t  ttl;
122     nd_mac_addr original_mac;
123     nd_mac_addr target_mac;
124 };
125 
126 static const struct tok cfm_ltm_flag_values[] = {
127     { 0x80, "Use Forwarding-DB only"},
128     { 0, NULL}
129 };
130 
131 struct cfm_ltr_t {
132     nd_uint32_t transaction_id;
133     nd_uint8_t  ttl;
134     nd_uint8_t  replay_action;
135 };
136 
137 static const struct tok cfm_ltr_flag_values[] = {
138     { 0x80, "UseFDB Only"},
139     { 0x40, "FwdYes"},
140     { 0x20, "Terminal MEP"},
141     { 0, NULL}
142 };
143 
144 static const struct tok cfm_ltr_replay_action_values[] = {
145     { 1, "Exact Match"},
146     { 2, "Filtering DB"},
147     { 3, "MIP CCM DB"},
148     { 0, NULL}
149 };
150 
151 
152 #define CFM_TLV_END 0
153 #define CFM_TLV_SENDER_ID 1
154 #define CFM_TLV_PORT_STATUS 2
155 #define CFM_TLV_INTERFACE_STATUS 3
156 #define CFM_TLV_DATA 4
157 #define CFM_TLV_REPLY_INGRESS 5
158 #define CFM_TLV_REPLY_EGRESS 6
159 #define CFM_TLV_PRIVATE 31
160 
161 static const struct tok cfm_tlv_values[] = {
162     { CFM_TLV_END, "End"},
163     { CFM_TLV_SENDER_ID, "Sender ID"},
164     { CFM_TLV_PORT_STATUS, "Port status"},
165     { CFM_TLV_INTERFACE_STATUS, "Interface status"},
166     { CFM_TLV_DATA, "Data"},
167     { CFM_TLV_REPLY_INGRESS, "Reply Ingress"},
168     { CFM_TLV_REPLY_EGRESS, "Reply Egress"},
169     { CFM_TLV_PRIVATE, "Organization Specific"},
170     { 0, NULL}
171 };
172 
173 /*
174  * TLVs
175  */
176 
177 struct cfm_tlv_header_t {
178     nd_uint8_t  type;
179     nd_uint16_t length;
180 };
181 
182 /* FIXME define TLV formats */
183 
184 static const struct tok cfm_tlv_port_status_values[] = {
185     { 1, "Blocked"},
186     { 2, "Up"},
187     { 0, NULL}
188 };
189 
190 static const struct tok cfm_tlv_interface_status_values[] = {
191     { 1, "Up"},
192     { 2, "Down"},
193     { 3, "Testing"},
194     { 5, "Dormant"},
195     { 6, "not present"},
196     { 7, "lower Layer down"},
197     { 0, NULL}
198 };
199 
200 #define CFM_CHASSIS_ID_CHASSIS_COMPONENT 1
201 #define CFM_CHASSIS_ID_INTERFACE_ALIAS 2
202 #define CFM_CHASSIS_ID_PORT_COMPONENT 3
203 #define CFM_CHASSIS_ID_MAC_ADDRESS 4
204 #define CFM_CHASSIS_ID_NETWORK_ADDRESS 5
205 #define CFM_CHASSIS_ID_INTERFACE_NAME 6
206 #define CFM_CHASSIS_ID_LOCAL 7
207 
208 static const struct tok cfm_tlv_senderid_chassisid_values[] = {
209     { 0, "Reserved"},
210     { CFM_CHASSIS_ID_CHASSIS_COMPONENT, "Chassis component"},
211     { CFM_CHASSIS_ID_INTERFACE_ALIAS, "Interface alias"},
212     { CFM_CHASSIS_ID_PORT_COMPONENT, "Port component"},
213     { CFM_CHASSIS_ID_MAC_ADDRESS, "MAC address"},
214     { CFM_CHASSIS_ID_NETWORK_ADDRESS, "Network address"},
215     { CFM_CHASSIS_ID_INTERFACE_NAME, "Interface name"},
216     { CFM_CHASSIS_ID_LOCAL, "Locally assigned"},
217     { 0, NULL}
218 };
219 
220 
221 static int
222 cfm_network_addr_print(netdissect_options *ndo,
223                        const u_char *tptr, const u_int length)
224 {
225     u_int network_addr_type;
226     u_int hexdump =  FALSE;
227 
228     /*
229      * Although AFIs are typically 2 octets wide,
230      * 802.1ab specifies that this field width
231      * is only one octet.
232      */
233     if (length < 1) {
234         ND_PRINT("\n\t  Network Address Type (invalid, no data");
235         return hexdump;
236     }
237     /* The calling function must make any due ND_TCHECK calls. */
238     network_addr_type = GET_U_1(tptr);
239     ND_PRINT("\n\t  Network Address Type %s (%u)",
240            tok2str(af_values, "Unknown", network_addr_type),
241            network_addr_type);
242 
243     /*
244      * Resolve the passed in Address.
245      */
246     switch(network_addr_type) {
247     case AFNUM_INET:
248         if (length != 1 + 4) {
249             ND_PRINT("(invalid IPv4 address length %u)", length - 1);
250             hexdump = TRUE;
251             break;
252         }
253         ND_PRINT(", %s", GET_IPADDR_STRING(tptr + 1));
254         break;
255 
256     case AFNUM_INET6:
257         if (length != 1 + 16) {
258             ND_PRINT("(invalid IPv6 address length %u)", length - 1);
259             hexdump = TRUE;
260             break;
261         }
262         ND_PRINT(", %s", GET_IP6ADDR_STRING(tptr + 1));
263         break;
264 
265     default:
266         hexdump = TRUE;
267         break;
268     }
269 
270     return hexdump;
271 }
272 
273 void
274 cfm_print(netdissect_options *ndo,
275           const u_char *pptr, u_int length)
276 {
277     const struct cfm_common_header_t *cfm_common_header;
278     uint8_t mdlevel_version, opcode, flags, first_tlv_offset;
279     const struct cfm_tlv_header_t *cfm_tlv_header;
280     const uint8_t *tptr, *tlv_ptr;
281     const uint8_t *namesp;
282     u_int names_data_remaining;
283     uint8_t md_nameformat, md_namelength;
284     const uint8_t *md_name;
285     uint8_t ma_nameformat, ma_namelength;
286     const uint8_t *ma_name;
287     u_int hexdump, tlen, cfm_tlv_len, cfm_tlv_type, ccm_interval;
288 
289 
290     union {
291         const struct cfm_ccm_t *cfm_ccm;
292         const struct cfm_lbm_t *cfm_lbm;
293         const struct cfm_ltm_t *cfm_ltm;
294         const struct cfm_ltr_t *cfm_ltr;
295     } msg_ptr;
296 
297     ndo->ndo_protocol = "cfm";
298     tptr=pptr;
299     cfm_common_header = (const struct cfm_common_header_t *)pptr;
300     if (length < sizeof(*cfm_common_header))
301         goto tooshort;
302     ND_TCHECK_SIZE(cfm_common_header);
303 
304     /*
305      * Sanity checking of the header.
306      */
307     mdlevel_version = GET_U_1(cfm_common_header->mdlevel_version);
308     if (CFM_EXTRACT_VERSION(mdlevel_version) != CFM_VERSION) {
309 	ND_PRINT("CFMv%u not supported, length %u",
310                CFM_EXTRACT_VERSION(mdlevel_version), length);
311 	return;
312     }
313 
314     opcode = GET_U_1(cfm_common_header->opcode);
315     ND_PRINT("CFMv%u %s, MD Level %u, length %u",
316            CFM_EXTRACT_VERSION(mdlevel_version),
317            tok2str(cfm_opcode_values, "unknown (%u)", opcode),
318            CFM_EXTRACT_MD_LEVEL(mdlevel_version),
319            length);
320 
321     /*
322      * In non-verbose mode just print the opcode and md-level.
323      */
324     if (ndo->ndo_vflag < 1) {
325         return;
326     }
327 
328     flags = GET_U_1(cfm_common_header->flags);
329     first_tlv_offset = GET_U_1(cfm_common_header->first_tlv_offset);
330     ND_PRINT("\n\tFirst TLV offset %u", first_tlv_offset);
331 
332     tptr += sizeof(struct cfm_common_header_t);
333     tlen = length - sizeof(struct cfm_common_header_t);
334 
335     /*
336      * Sanity check the first TLV offset.
337      */
338     if (first_tlv_offset > tlen) {
339         ND_PRINT(" (too large, must be <= %u)", tlen);
340         return;
341     }
342 
343     switch (opcode) {
344     case CFM_OPCODE_CCM:
345         msg_ptr.cfm_ccm = (const struct cfm_ccm_t *)tptr;
346         if (first_tlv_offset < sizeof(*msg_ptr.cfm_ccm)) {
347             ND_PRINT(" (too small 1, must be >= %zu)",
348                      sizeof(*msg_ptr.cfm_ccm));
349             return;
350         }
351         if (tlen < sizeof(*msg_ptr.cfm_ccm))
352             goto tooshort;
353         ND_TCHECK_SIZE(msg_ptr.cfm_ccm);
354 
355         ccm_interval = CFM_EXTRACT_CCM_INTERVAL(flags);
356         ND_PRINT(", Flags [CCM Interval %u%s]",
357                ccm_interval,
358                flags & CFM_CCM_RDI_FLAG ?
359                ", RDI" : "");
360 
361         /*
362          * Resolve the CCM interval field.
363          */
364         if (ccm_interval) {
365             ND_PRINT("\n\t  CCM Interval %.3fs"
366                    ", min CCM Lifetime %.3fs, max CCM Lifetime %.3fs",
367                    ccm_interval_base[ccm_interval],
368                    ccm_interval_base[ccm_interval] * CCM_INTERVAL_MIN_MULTIPLIER,
369                    ccm_interval_base[ccm_interval] * CCM_INTERVAL_MAX_MULTIPLIER);
370         }
371 
372         ND_PRINT("\n\t  Sequence Number 0x%08x, MA-End-Point-ID 0x%04x",
373                GET_BE_U_4(msg_ptr.cfm_ccm->sequence),
374                GET_BE_U_2(msg_ptr.cfm_ccm->ma_epi));
375 
376         namesp = msg_ptr.cfm_ccm->names;
377         names_data_remaining = sizeof(msg_ptr.cfm_ccm->names);
378 
379         /*
380          * Resolve the MD fields.
381          */
382         md_nameformat = GET_U_1(namesp);
383         namesp++;
384         names_data_remaining--;  /* We know this is != 0 */
385         if (md_nameformat != CFM_CCM_MD_FORMAT_NONE) {
386             md_namelength = GET_U_1(namesp);
387             namesp++;
388             names_data_remaining--; /* We know this is !=0 */
389             ND_PRINT("\n\t  MD Name Format %s (%u), MD Name length %u",
390                    tok2str(cfm_md_nameformat_values, "Unknown",
391                            md_nameformat),
392                    md_nameformat,
393                    md_namelength);
394 
395             /*
396              * -3 for the MA short name format and length and one byte
397              * of MA short name.
398              */
399             if (md_namelength > names_data_remaining - 3) {
400                 ND_PRINT(" (too large, must be <= %u)", names_data_remaining - 2);
401                 return;
402             }
403 
404             md_name = namesp;
405             ND_PRINT("\n\t  MD Name: ");
406             switch (md_nameformat) {
407             case CFM_CCM_MD_FORMAT_DNS:
408             case CFM_CCM_MD_FORMAT_CHAR:
409                 nd_printjnp(ndo, md_name, md_namelength);
410                 break;
411 
412             case CFM_CCM_MD_FORMAT_MAC:
413                 if (md_namelength == MAC_ADDR_LEN) {
414                     ND_PRINT("\n\t  MAC %s", GET_ETHERADDR_STRING(md_name));
415                 } else {
416                     ND_PRINT("\n\t  MAC (length invalid)");
417                 }
418                 break;
419 
420                 /* FIXME add printers for those MD formats - hexdump for now */
421             case CFM_CCM_MA_FORMAT_8021:
422             default:
423                 print_unknown_data(ndo, md_name, "\n\t    ",
424                                    md_namelength);
425             }
426             namesp += md_namelength;
427             names_data_remaining -= md_namelength;
428         } else {
429             ND_PRINT("\n\t  MD Name Format %s (%u)",
430                    tok2str(cfm_md_nameformat_values, "Unknown",
431                            md_nameformat),
432                    md_nameformat);
433         }
434 
435 
436         /*
437          * Resolve the MA fields.
438          */
439         ma_nameformat = GET_U_1(namesp);
440         namesp++;
441         names_data_remaining--; /* We know this is != 0 */
442         ma_namelength = GET_U_1(namesp);
443         namesp++;
444         names_data_remaining--; /* We know this is != 0 */
445         ND_PRINT("\n\t  MA Name-Format %s (%u), MA name length %u",
446                tok2str(cfm_ma_nameformat_values, "Unknown",
447                        ma_nameformat),
448                ma_nameformat,
449                ma_namelength);
450 
451         if (ma_namelength > names_data_remaining) {
452             ND_PRINT(" (too large, must be <= %u)", names_data_remaining);
453             return;
454         }
455 
456         ma_name = namesp;
457         ND_PRINT("\n\t  MA Name: ");
458         switch (ma_nameformat) {
459         case CFM_CCM_MA_FORMAT_CHAR:
460             nd_printjnp(ndo, ma_name, ma_namelength);
461             break;
462 
463             /* FIXME add printers for those MA formats - hexdump for now */
464         case CFM_CCM_MA_FORMAT_8021:
465         case CFM_CCM_MA_FORMAT_VID:
466         case CFM_CCM_MA_FORMAT_INT:
467         case CFM_CCM_MA_FORMAT_VPN:
468         default:
469             print_unknown_data(ndo, ma_name, "\n\t    ", ma_namelength);
470         }
471         break;
472 
473     case CFM_OPCODE_LTM:
474         msg_ptr.cfm_ltm = (const struct cfm_ltm_t *)tptr;
475         if (first_tlv_offset < sizeof(*msg_ptr.cfm_ltm)) {
476             ND_PRINT(" (too small 4, must be >= %zu)",
477                      sizeof(*msg_ptr.cfm_ltm));
478             return;
479         }
480         if (tlen < sizeof(*msg_ptr.cfm_ltm))
481             goto tooshort;
482         ND_TCHECK_SIZE(msg_ptr.cfm_ltm);
483 
484         ND_PRINT(", Flags [%s]",
485                bittok2str(cfm_ltm_flag_values, "none", flags));
486 
487         ND_PRINT("\n\t  Transaction-ID 0x%08x, ttl %u",
488                GET_BE_U_4(msg_ptr.cfm_ltm->transaction_id),
489                GET_U_1(msg_ptr.cfm_ltm->ttl));
490 
491         ND_PRINT("\n\t  Original-MAC %s, Target-MAC %s",
492                GET_ETHERADDR_STRING(msg_ptr.cfm_ltm->original_mac),
493                GET_ETHERADDR_STRING(msg_ptr.cfm_ltm->target_mac));
494         break;
495 
496     case CFM_OPCODE_LTR:
497         msg_ptr.cfm_ltr = (const struct cfm_ltr_t *)tptr;
498         if (first_tlv_offset < sizeof(*msg_ptr.cfm_ltr)) {
499             ND_PRINT(" (too small 5, must be >= %zu)",
500                      sizeof(*msg_ptr.cfm_ltr));
501             return;
502         }
503         if (tlen < sizeof(*msg_ptr.cfm_ltr))
504             goto tooshort;
505         ND_TCHECK_SIZE(msg_ptr.cfm_ltr);
506 
507         ND_PRINT(", Flags [%s]",
508                bittok2str(cfm_ltr_flag_values, "none", flags));
509 
510         ND_PRINT("\n\t  Transaction-ID 0x%08x, ttl %u",
511                GET_BE_U_4(msg_ptr.cfm_ltr->transaction_id),
512                GET_U_1(msg_ptr.cfm_ltr->ttl));
513 
514         ND_PRINT("\n\t  Replay-Action %s (%u)",
515                tok2str(cfm_ltr_replay_action_values,
516                        "Unknown",
517                        GET_U_1(msg_ptr.cfm_ltr->replay_action)),
518                GET_U_1(msg_ptr.cfm_ltr->replay_action));
519         break;
520 
521         /*
522          * No message decoder yet.
523          * Hexdump everything up until the start of the TLVs
524          */
525     case CFM_OPCODE_LBR:
526     case CFM_OPCODE_LBM:
527     default:
528         print_unknown_data(ndo, tptr, "\n\t  ",
529                            tlen -  first_tlv_offset);
530         break;
531     }
532 
533     tptr += first_tlv_offset;
534     tlen -= first_tlv_offset;
535 
536     while (tlen > 0) {
537         cfm_tlv_header = (const struct cfm_tlv_header_t *)tptr;
538 
539         /* Enough to read the tlv type ? */
540         cfm_tlv_type = GET_U_1(cfm_tlv_header->type);
541 
542         ND_PRINT("\n\t%s TLV (0x%02x)",
543                tok2str(cfm_tlv_values, "Unknown", cfm_tlv_type),
544                cfm_tlv_type);
545 
546         if (cfm_tlv_type == CFM_TLV_END) {
547             /* Length is "Not present if the Type field is 0." */
548             return;
549         }
550 
551         /* do we have the full tlv header ? */
552         if (tlen < sizeof(struct cfm_tlv_header_t))
553             goto tooshort;
554         ND_TCHECK_LEN(tptr, sizeof(struct cfm_tlv_header_t));
555         cfm_tlv_len=GET_BE_U_2(cfm_tlv_header->length);
556 
557         ND_PRINT(", length %u", cfm_tlv_len);
558 
559         tptr += sizeof(struct cfm_tlv_header_t);
560         tlen -= sizeof(struct cfm_tlv_header_t);
561         tlv_ptr = tptr;
562 
563         /* do we have the full tlv ? */
564         if (tlen < cfm_tlv_len)
565             goto tooshort;
566         ND_TCHECK_LEN(tptr, cfm_tlv_len);
567         hexdump = FALSE;
568 
569         switch(cfm_tlv_type) {
570         case CFM_TLV_PORT_STATUS:
571             if (cfm_tlv_len < 1) {
572                 ND_PRINT(" (too short, must be >= 1)");
573                 return;
574             }
575             ND_PRINT(", Status: %s (%u)",
576                    tok2str(cfm_tlv_port_status_values, "Unknown", GET_U_1(tptr)),
577                    GET_U_1(tptr));
578             break;
579 
580         case CFM_TLV_INTERFACE_STATUS:
581             if (cfm_tlv_len < 1) {
582                 ND_PRINT(" (too short, must be >= 1)");
583                 return;
584             }
585             ND_PRINT(", Status: %s (%u)",
586                    tok2str(cfm_tlv_interface_status_values, "Unknown", GET_U_1(tptr)),
587                    GET_U_1(tptr));
588             break;
589 
590         case CFM_TLV_PRIVATE:
591             if (cfm_tlv_len < 4) {
592                 ND_PRINT(" (too short, must be >= 4)");
593                 return;
594             }
595             ND_PRINT(", Vendor: %s (%u), Sub-Type %u",
596                    tok2str(oui_values,"Unknown", GET_BE_U_3(tptr)),
597                    GET_BE_U_3(tptr),
598                    GET_U_1(tptr + 3));
599             hexdump = TRUE;
600             break;
601 
602         case CFM_TLV_SENDER_ID:
603         {
604             u_int chassis_id_type, chassis_id_length;
605             u_int mgmt_addr_length;
606 
607             if (cfm_tlv_len < 1) {
608                 ND_PRINT(" (too short, must be >= 1)");
609                 goto next_tlv;
610             }
611 
612             /*
613              * Get the Chassis ID length and check it.
614              * IEEE 802.1Q-2014 Section 21.5.3.1
615              */
616             chassis_id_length = GET_U_1(tptr);
617             tptr++;
618             tlen--;
619             cfm_tlv_len--;
620 
621             if (chassis_id_length) {
622                 /*
623                  * IEEE 802.1Q-2014 Section 21.5.3.2: Chassis ID Subtype, references
624                  * IEEE 802.1AB-2005 Section 9.5.2.2, subsequently
625                  * IEEE 802.1AB-2016 Section 8.5.2.2: chassis ID subtype
626                  */
627                 if (cfm_tlv_len < 1) {
628                     ND_PRINT("\n\t  (TLV too short)");
629                     goto next_tlv;
630                 }
631                 chassis_id_type = GET_U_1(tptr);
632                 cfm_tlv_len--;
633                 ND_PRINT("\n\t  Chassis-ID Type %s (%u), Chassis-ID length %u",
634                        tok2str(cfm_tlv_senderid_chassisid_values,
635                                "Unknown",
636                                chassis_id_type),
637                        chassis_id_type,
638                        chassis_id_length);
639 
640                 if (cfm_tlv_len < chassis_id_length) {
641                     ND_PRINT("\n\t  (TLV too short)");
642                     goto next_tlv;
643                 }
644 
645                 /* IEEE 802.1Q-2014 Section 21.5.3.3: Chassis ID */
646                 switch (chassis_id_type) {
647                 case CFM_CHASSIS_ID_MAC_ADDRESS:
648                     if (chassis_id_length != MAC_ADDR_LEN) {
649                         ND_PRINT(" (invalid MAC address length)");
650                         hexdump = TRUE;
651                         break;
652                     }
653                     ND_PRINT("\n\t  MAC %s", GET_ETHERADDR_STRING(tptr + 1));
654                     break;
655 
656                 case CFM_CHASSIS_ID_NETWORK_ADDRESS:
657                     hexdump |= cfm_network_addr_print(ndo, tptr + 1, chassis_id_length);
658                     break;
659 
660                 case CFM_CHASSIS_ID_INTERFACE_NAME: /* fall through */
661                 case CFM_CHASSIS_ID_INTERFACE_ALIAS:
662                 case CFM_CHASSIS_ID_LOCAL:
663                 case CFM_CHASSIS_ID_CHASSIS_COMPONENT:
664                 case CFM_CHASSIS_ID_PORT_COMPONENT:
665                     nd_printjnp(ndo, tptr + 1, chassis_id_length);
666                     break;
667 
668                 default:
669                     hexdump = TRUE;
670                     break;
671                 }
672                 cfm_tlv_len -= chassis_id_length;
673 
674                 tptr += 1 + chassis_id_length;
675                 tlen -= 1 + chassis_id_length;
676             }
677 
678             /*
679              * Check if there is a Management Address.
680              * IEEE 802.1Q-2014 Section 21.5.3.4: Management Address Domain Length
681              * This and all subsequent fields are not present if the TLV length
682              * allows only the above fields.
683              */
684             if (cfm_tlv_len == 0) {
685                 /* No, there isn't; we're done. */
686                 break;
687             }
688 
689             /* Here mgmt_addr_length stands for the management domain length. */
690             mgmt_addr_length = GET_U_1(tptr);
691             tptr++;
692             tlen--;
693             cfm_tlv_len--;
694             ND_PRINT("\n\t  Management Address Domain Length %u", mgmt_addr_length);
695             if (mgmt_addr_length) {
696                 /* IEEE 802.1Q-2014 Section 21.5.3.5: Management Address Domain */
697                 if (cfm_tlv_len < mgmt_addr_length) {
698                     ND_PRINT("\n\t  (TLV too short)");
699                     goto next_tlv;
700                 }
701                 cfm_tlv_len -= mgmt_addr_length;
702                 /*
703                  * XXX - this is an OID; print it as such.
704                  */
705                 hex_print(ndo, "\n\t  Management Address Domain: ", tptr, mgmt_addr_length);
706                 tptr += mgmt_addr_length;
707                 tlen -= mgmt_addr_length;
708 
709                 /*
710                  * IEEE 802.1Q-2014 Section 21.5.3.6: Management Address Length
711                  * This field is present if Management Address Domain Length is not 0.
712                  */
713                 if (cfm_tlv_len < 1) {
714                     ND_PRINT(" (Management Address Length is missing)");
715                     hexdump = TRUE;
716                     break;
717                 }
718 
719                 /* Here mgmt_addr_length stands for the management address length. */
720                 mgmt_addr_length = GET_U_1(tptr);
721                 tptr++;
722                 tlen--;
723                 cfm_tlv_len--;
724                 ND_PRINT("\n\t  Management Address Length %u", mgmt_addr_length);
725                 if (mgmt_addr_length) {
726                     /* IEEE 802.1Q-2014 Section 21.5.3.7: Management Address */
727                     if (cfm_tlv_len < mgmt_addr_length) {
728                         ND_PRINT("\n\t  (TLV too short)");
729                         return;
730                     }
731                     cfm_tlv_len -= mgmt_addr_length;
732                     /*
733                      * XXX - this is a TransportDomain; print it as such.
734                      */
735                     hex_print(ndo, "\n\t  Management Address: ", tptr, mgmt_addr_length);
736                     tptr += mgmt_addr_length;
737                     tlen -= mgmt_addr_length;
738                 }
739             }
740             break;
741         }
742 
743             /*
744              * FIXME those are the defined TLVs that lack a decoder
745              * you are welcome to contribute code ;-)
746              */
747 
748         case CFM_TLV_DATA:
749         case CFM_TLV_REPLY_INGRESS:
750         case CFM_TLV_REPLY_EGRESS:
751         default:
752             hexdump = TRUE;
753             break;
754         }
755         /* do we want to see an additional hexdump ? */
756         if (hexdump || ndo->ndo_vflag > 1)
757             print_unknown_data(ndo, tlv_ptr, "\n\t  ", cfm_tlv_len);
758 
759 next_tlv:
760         tptr+=cfm_tlv_len;
761         tlen-=cfm_tlv_len;
762     }
763     return;
764 
765 tooshort:
766     ND_PRINT("\n\t\t packet is too short");
767     return;
768 
769 trunc:
770     nd_print_trunc(ndo);
771 }
772