xref: /freebsd/contrib/tcpdump/print-cfm.c (revision 0a7e5f1f02aad2ff5fff1c60f44c6975fd07e1d9)
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 <config.h>
21 
22 #include "netdissect-stdinc.h"
23 
24 #include "netdissect.h"
25 #include "extract.h"
26 #include "addrtoname.h"
27 #include "oui.h"
28 #include "af.h"
29 
30 
31 struct cfm_common_header_t {
32     nd_uint8_t mdlevel_version;
33     nd_uint8_t opcode;
34     nd_uint8_t flags;
35     nd_uint8_t first_tlv_offset;
36 };
37 
38 #define	CFM_VERSION 0
39 #define CFM_EXTRACT_VERSION(x) ((x)&0x1f)
40 #define CFM_EXTRACT_MD_LEVEL(x) (((x)&0xe0)>>5)
41 
42 #define	CFM_OPCODE_CCM 1
43 #define	CFM_OPCODE_LBR 2
44 #define	CFM_OPCODE_LBM 3
45 #define	CFM_OPCODE_LTR 4
46 #define	CFM_OPCODE_LTM 5
47 
48 static const struct tok cfm_opcode_values[] = {
49     { CFM_OPCODE_CCM, "Continuity Check Message"},
50     { CFM_OPCODE_LBR, "Loopback Reply"},
51     { CFM_OPCODE_LBM, "Loopback Message"},
52     { CFM_OPCODE_LTR, "Linktrace Reply"},
53     { CFM_OPCODE_LTM, "Linktrace Message"},
54     { 0, NULL}
55 };
56 
57 /*
58  * Message Formats.
59  */
60 struct cfm_ccm_t {
61     nd_uint32_t sequence;
62     nd_uint16_t ma_epi;
63     nd_byte     names[48];
64     nd_byte     itu_t_y_1731[16];
65 };
66 
67 /*
68  * Timer Bases for the CCM Interval field.
69  * Expressed in units of seconds.
70  */
71 static const float ccm_interval_base[8] = {0.0f, 0.003333f, 0.01f, 0.1f, 1.0f, 10.0f, 60.0f, 600.0f};
72 #define CCM_INTERVAL_MIN_MULTIPLIER 3.25
73 #define CCM_INTERVAL_MAX_MULTIPLIER 3.5
74 
75 #define CFM_CCM_RDI_FLAG 0x80
76 #define CFM_EXTRACT_CCM_INTERVAL(x) ((x)&0x07)
77 
78 #define CFM_CCM_MD_FORMAT_8021 0
79 #define CFM_CCM_MD_FORMAT_NONE 1
80 #define CFM_CCM_MD_FORMAT_DNS  2
81 #define CFM_CCM_MD_FORMAT_MAC  3
82 #define CFM_CCM_MD_FORMAT_CHAR 4
83 
84 static const struct tok cfm_md_nameformat_values[] = {
85     { CFM_CCM_MD_FORMAT_8021, "IEEE 802.1"},
86     { CFM_CCM_MD_FORMAT_NONE, "No MD Name present"},
87     { CFM_CCM_MD_FORMAT_DNS, "DNS string"},
88     { CFM_CCM_MD_FORMAT_MAC, "MAC + 16Bit Integer"},
89     { CFM_CCM_MD_FORMAT_CHAR, "Character string"},
90     { 0, NULL}
91 };
92 
93 #define CFM_CCM_MA_FORMAT_8021 0
94 #define CFM_CCM_MA_FORMAT_VID  1
95 #define CFM_CCM_MA_FORMAT_CHAR 2
96 #define CFM_CCM_MA_FORMAT_INT  3
97 #define CFM_CCM_MA_FORMAT_VPN  4
98 
99 static const struct tok cfm_ma_nameformat_values[] = {
100     { CFM_CCM_MA_FORMAT_8021, "IEEE 802.1"},
101     { CFM_CCM_MA_FORMAT_VID, "Primary VID"},
102     { CFM_CCM_MA_FORMAT_CHAR, "Character string"},
103     { CFM_CCM_MA_FORMAT_INT, "16Bit Integer"},
104     { CFM_CCM_MA_FORMAT_VPN, "RFC2685 VPN-ID"},
105     { 0, NULL}
106 };
107 
108 struct cfm_lbm_t {
109     nd_uint32_t transaction_id;
110 };
111 
112 struct cfm_ltm_t {
113     nd_uint32_t transaction_id;
114     nd_uint8_t  ttl;
115     nd_mac_addr original_mac;
116     nd_mac_addr target_mac;
117 };
118 
119 static const struct tok cfm_ltm_flag_values[] = {
120     { 0x80, "Use Forwarding-DB only"},
121     { 0, NULL}
122 };
123 
124 struct cfm_ltr_t {
125     nd_uint32_t transaction_id;
126     nd_uint8_t  ttl;
127     nd_uint8_t  replay_action;
128 };
129 
130 static const struct tok cfm_ltr_flag_values[] = {
131     { 0x80, "UseFDB Only"},
132     { 0x40, "FwdYes"},
133     { 0x20, "Terminal MEP"},
134     { 0, NULL}
135 };
136 
137 static const struct tok cfm_ltr_replay_action_values[] = {
138     { 1, "Exact Match"},
139     { 2, "Filtering DB"},
140     { 3, "MIP CCM DB"},
141     { 0, NULL}
142 };
143 
144 
145 #define CFM_TLV_END 0
146 #define CFM_TLV_SENDER_ID 1
147 #define CFM_TLV_PORT_STATUS 2
148 #define CFM_TLV_INTERFACE_STATUS 3
149 #define CFM_TLV_DATA 4
150 #define CFM_TLV_REPLY_INGRESS 5
151 #define CFM_TLV_REPLY_EGRESS 6
152 #define CFM_TLV_PRIVATE 31
153 
154 static const struct tok cfm_tlv_values[] = {
155     { CFM_TLV_END, "End"},
156     { CFM_TLV_SENDER_ID, "Sender ID"},
157     { CFM_TLV_PORT_STATUS, "Port status"},
158     { CFM_TLV_INTERFACE_STATUS, "Interface status"},
159     { CFM_TLV_DATA, "Data"},
160     { CFM_TLV_REPLY_INGRESS, "Reply Ingress"},
161     { CFM_TLV_REPLY_EGRESS, "Reply Egress"},
162     { CFM_TLV_PRIVATE, "Organization Specific"},
163     { 0, NULL}
164 };
165 
166 /*
167  * TLVs
168  */
169 
170 struct cfm_tlv_header_t {
171     nd_uint8_t  type;
172     nd_uint16_t length;
173 };
174 
175 /* FIXME define TLV formats */
176 
177 static const struct tok cfm_tlv_port_status_values[] = {
178     { 1, "Blocked"},
179     { 2, "Up"},
180     { 0, NULL}
181 };
182 
183 static const struct tok cfm_tlv_interface_status_values[] = {
184     { 1, "Up"},
185     { 2, "Down"},
186     { 3, "Testing"},
187     { 5, "Dormant"},
188     { 6, "not present"},
189     { 7, "lower Layer down"},
190     { 0, NULL}
191 };
192 
193 #define CFM_CHASSIS_ID_CHASSIS_COMPONENT 1
194 #define CFM_CHASSIS_ID_INTERFACE_ALIAS 2
195 #define CFM_CHASSIS_ID_PORT_COMPONENT 3
196 #define CFM_CHASSIS_ID_MAC_ADDRESS 4
197 #define CFM_CHASSIS_ID_NETWORK_ADDRESS 5
198 #define CFM_CHASSIS_ID_INTERFACE_NAME 6
199 #define CFM_CHASSIS_ID_LOCAL 7
200 
201 static const struct tok cfm_tlv_senderid_chassisid_values[] = {
202     { 0, "Reserved"},
203     { CFM_CHASSIS_ID_CHASSIS_COMPONENT, "Chassis component"},
204     { CFM_CHASSIS_ID_INTERFACE_ALIAS, "Interface alias"},
205     { CFM_CHASSIS_ID_PORT_COMPONENT, "Port component"},
206     { CFM_CHASSIS_ID_MAC_ADDRESS, "MAC address"},
207     { CFM_CHASSIS_ID_NETWORK_ADDRESS, "Network address"},
208     { CFM_CHASSIS_ID_INTERFACE_NAME, "Interface name"},
209     { CFM_CHASSIS_ID_LOCAL, "Locally assigned"},
210     { 0, NULL}
211 };
212 
213 
214 static int
cfm_network_addr_print(netdissect_options * ndo,const u_char * tptr,const u_int length)215 cfm_network_addr_print(netdissect_options *ndo,
216                        const u_char *tptr, const u_int length)
217 {
218     u_int network_addr_type;
219     u_int hexdump =  FALSE;
220 
221     /*
222      * Although AFIs are typically 2 octets wide,
223      * 802.1ab specifies that this field width
224      * is only one octet.
225      */
226     if (length < 1) {
227         ND_PRINT("\n\t  Network Address Type (invalid, no data");
228         return hexdump;
229     }
230     /* The calling function must make any due ND_TCHECK calls. */
231     network_addr_type = GET_U_1(tptr);
232     ND_PRINT("\n\t  Network Address Type %s (%u)",
233            tok2str(af_values, "Unknown", network_addr_type),
234            network_addr_type);
235 
236     /*
237      * Resolve the passed in Address.
238      */
239     switch(network_addr_type) {
240     case AFNUM_INET:
241         if (length != 1 + 4) {
242             ND_PRINT("(invalid IPv4 address length %u)", length - 1);
243             hexdump = TRUE;
244             break;
245         }
246         ND_PRINT(", %s", GET_IPADDR_STRING(tptr + 1));
247         break;
248 
249     case AFNUM_INET6:
250         if (length != 1 + 16) {
251             ND_PRINT("(invalid IPv6 address length %u)", length - 1);
252             hexdump = TRUE;
253             break;
254         }
255         ND_PRINT(", %s", GET_IP6ADDR_STRING(tptr + 1));
256         break;
257 
258     default:
259         hexdump = TRUE;
260         break;
261     }
262 
263     return hexdump;
264 }
265 
266 void
cfm_print(netdissect_options * ndo,const u_char * pptr,u_int length)267 cfm_print(netdissect_options *ndo,
268           const u_char *pptr, u_int length)
269 {
270     const struct cfm_common_header_t *cfm_common_header;
271     uint8_t mdlevel_version, opcode, flags, first_tlv_offset;
272     const struct cfm_tlv_header_t *cfm_tlv_header;
273     const uint8_t *tptr, *tlv_ptr;
274     const uint8_t *namesp;
275     u_int names_data_remaining;
276     uint8_t md_nameformat, md_namelength;
277     const uint8_t *md_name;
278     uint8_t ma_nameformat, ma_namelength;
279     const uint8_t *ma_name;
280     u_int hexdump, tlen, cfm_tlv_len, cfm_tlv_type, ccm_interval;
281 
282 
283     union {
284         const struct cfm_ccm_t *cfm_ccm;
285         const struct cfm_lbm_t *cfm_lbm;
286         const struct cfm_ltm_t *cfm_ltm;
287         const struct cfm_ltr_t *cfm_ltr;
288     } msg_ptr;
289 
290     ndo->ndo_protocol = "cfm";
291     tptr=pptr;
292     cfm_common_header = (const struct cfm_common_header_t *)pptr;
293     if (length < sizeof(*cfm_common_header))
294         goto tooshort;
295     ND_TCHECK_SIZE(cfm_common_header);
296 
297     /*
298      * Sanity checking of the header.
299      */
300     mdlevel_version = GET_U_1(cfm_common_header->mdlevel_version);
301     if (CFM_EXTRACT_VERSION(mdlevel_version) != CFM_VERSION) {
302 	ND_PRINT("CFMv%u not supported, length %u",
303                CFM_EXTRACT_VERSION(mdlevel_version), length);
304 	return;
305     }
306 
307     opcode = GET_U_1(cfm_common_header->opcode);
308     ND_PRINT("CFMv%u %s, MD Level %u, length %u",
309            CFM_EXTRACT_VERSION(mdlevel_version),
310            tok2str(cfm_opcode_values, "unknown (%u)", opcode),
311            CFM_EXTRACT_MD_LEVEL(mdlevel_version),
312            length);
313 
314     /*
315      * In non-verbose mode just print the opcode and md-level.
316      */
317     if (ndo->ndo_vflag < 1) {
318         return;
319     }
320 
321     flags = GET_U_1(cfm_common_header->flags);
322     first_tlv_offset = GET_U_1(cfm_common_header->first_tlv_offset);
323     ND_PRINT("\n\tFirst TLV offset %u", first_tlv_offset);
324 
325     tptr += sizeof(struct cfm_common_header_t);
326     tlen = length - sizeof(struct cfm_common_header_t);
327 
328     /*
329      * Sanity check the first TLV offset.
330      */
331     if (first_tlv_offset > tlen) {
332         ND_PRINT(" (too large, must be <= %u)", tlen);
333         return;
334     }
335 
336     switch (opcode) {
337     case CFM_OPCODE_CCM:
338         msg_ptr.cfm_ccm = (const struct cfm_ccm_t *)tptr;
339         if (first_tlv_offset < sizeof(*msg_ptr.cfm_ccm)) {
340             ND_PRINT(" (too small 1, must be >= %zu)",
341                      sizeof(*msg_ptr.cfm_ccm));
342             return;
343         }
344         if (tlen < sizeof(*msg_ptr.cfm_ccm))
345             goto tooshort;
346         ND_TCHECK_SIZE(msg_ptr.cfm_ccm);
347 
348         ccm_interval = CFM_EXTRACT_CCM_INTERVAL(flags);
349         ND_PRINT(", Flags [CCM Interval %u%s]",
350                ccm_interval,
351                flags & CFM_CCM_RDI_FLAG ?
352                ", RDI" : "");
353 
354         /*
355          * Resolve the CCM interval field.
356          */
357         if (ccm_interval) {
358             ND_PRINT("\n\t  CCM Interval %.3fs"
359                    ", min CCM Lifetime %.3fs, max CCM Lifetime %.3fs",
360                    ccm_interval_base[ccm_interval],
361                    ccm_interval_base[ccm_interval] * CCM_INTERVAL_MIN_MULTIPLIER,
362                    ccm_interval_base[ccm_interval] * CCM_INTERVAL_MAX_MULTIPLIER);
363         }
364 
365         ND_PRINT("\n\t  Sequence Number 0x%08x, MA-End-Point-ID 0x%04x",
366                GET_BE_U_4(msg_ptr.cfm_ccm->sequence),
367                GET_BE_U_2(msg_ptr.cfm_ccm->ma_epi));
368 
369         namesp = msg_ptr.cfm_ccm->names;
370         names_data_remaining = sizeof(msg_ptr.cfm_ccm->names);
371 
372         /*
373          * Resolve the MD fields.
374          */
375         md_nameformat = GET_U_1(namesp);
376         namesp++;
377         names_data_remaining--;  /* We know this is != 0 */
378         if (md_nameformat != CFM_CCM_MD_FORMAT_NONE) {
379             md_namelength = GET_U_1(namesp);
380             namesp++;
381             names_data_remaining--; /* We know this is !=0 */
382             ND_PRINT("\n\t  MD Name Format %s (%u), MD Name length %u",
383                    tok2str(cfm_md_nameformat_values, "Unknown",
384                            md_nameformat),
385                    md_nameformat,
386                    md_namelength);
387 
388             /*
389              * -3 for the MA short name format and length and one byte
390              * of MA short name.
391              */
392             if (md_namelength > names_data_remaining - 3) {
393                 ND_PRINT(" (too large, must be <= %u)", names_data_remaining - 2);
394                 return;
395             }
396 
397             md_name = namesp;
398             ND_PRINT("\n\t  MD Name: ");
399             switch (md_nameformat) {
400             case CFM_CCM_MD_FORMAT_DNS:
401             case CFM_CCM_MD_FORMAT_CHAR:
402                 nd_printjnp(ndo, md_name, md_namelength);
403                 break;
404 
405             case CFM_CCM_MD_FORMAT_MAC:
406                 if (md_namelength == MAC_ADDR_LEN) {
407                     ND_PRINT("\n\t  MAC %s", GET_ETHERADDR_STRING(md_name));
408                 } else {
409                     ND_PRINT("\n\t  MAC (length invalid)");
410                 }
411                 break;
412 
413                 /* FIXME add printers for those MD formats - hexdump for now */
414             case CFM_CCM_MA_FORMAT_8021:
415             default:
416                 print_unknown_data(ndo, md_name, "\n\t    ",
417                                    md_namelength);
418             }
419             namesp += md_namelength;
420             names_data_remaining -= md_namelength;
421         } else {
422             ND_PRINT("\n\t  MD Name Format %s (%u)",
423                    tok2str(cfm_md_nameformat_values, "Unknown",
424                            md_nameformat),
425                    md_nameformat);
426         }
427 
428 
429         /*
430          * Resolve the MA fields.
431          */
432         ma_nameformat = GET_U_1(namesp);
433         namesp++;
434         names_data_remaining--; /* We know this is != 0 */
435         ma_namelength = GET_U_1(namesp);
436         namesp++;
437         names_data_remaining--; /* We know this is != 0 */
438         ND_PRINT("\n\t  MA Name-Format %s (%u), MA name length %u",
439                tok2str(cfm_ma_nameformat_values, "Unknown",
440                        ma_nameformat),
441                ma_nameformat,
442                ma_namelength);
443 
444         if (ma_namelength > names_data_remaining) {
445             ND_PRINT(" (too large, must be <= %u)", names_data_remaining);
446             return;
447         }
448 
449         ma_name = namesp;
450         ND_PRINT("\n\t  MA Name: ");
451         switch (ma_nameformat) {
452         case CFM_CCM_MA_FORMAT_CHAR:
453             nd_printjnp(ndo, ma_name, ma_namelength);
454             break;
455 
456             /* FIXME add printers for those MA formats - hexdump for now */
457         case CFM_CCM_MA_FORMAT_8021:
458         case CFM_CCM_MA_FORMAT_VID:
459         case CFM_CCM_MA_FORMAT_INT:
460         case CFM_CCM_MA_FORMAT_VPN:
461         default:
462             print_unknown_data(ndo, ma_name, "\n\t    ", ma_namelength);
463         }
464         break;
465 
466     case CFM_OPCODE_LTM:
467         msg_ptr.cfm_ltm = (const struct cfm_ltm_t *)tptr;
468         if (first_tlv_offset < sizeof(*msg_ptr.cfm_ltm)) {
469             ND_PRINT(" (too small 4, must be >= %zu)",
470                      sizeof(*msg_ptr.cfm_ltm));
471             return;
472         }
473         if (tlen < sizeof(*msg_ptr.cfm_ltm))
474             goto tooshort;
475         ND_TCHECK_SIZE(msg_ptr.cfm_ltm);
476 
477         ND_PRINT(", Flags [%s]",
478                bittok2str(cfm_ltm_flag_values, "none", flags));
479 
480         ND_PRINT("\n\t  Transaction-ID 0x%08x, ttl %u",
481                GET_BE_U_4(msg_ptr.cfm_ltm->transaction_id),
482                GET_U_1(msg_ptr.cfm_ltm->ttl));
483 
484         ND_PRINT("\n\t  Original-MAC %s, Target-MAC %s",
485                GET_ETHERADDR_STRING(msg_ptr.cfm_ltm->original_mac),
486                GET_ETHERADDR_STRING(msg_ptr.cfm_ltm->target_mac));
487         break;
488 
489     case CFM_OPCODE_LTR:
490         msg_ptr.cfm_ltr = (const struct cfm_ltr_t *)tptr;
491         if (first_tlv_offset < sizeof(*msg_ptr.cfm_ltr)) {
492             ND_PRINT(" (too small 5, must be >= %zu)",
493                      sizeof(*msg_ptr.cfm_ltr));
494             return;
495         }
496         if (tlen < sizeof(*msg_ptr.cfm_ltr))
497             goto tooshort;
498         ND_TCHECK_SIZE(msg_ptr.cfm_ltr);
499 
500         ND_PRINT(", Flags [%s]",
501                bittok2str(cfm_ltr_flag_values, "none", flags));
502 
503         ND_PRINT("\n\t  Transaction-ID 0x%08x, ttl %u",
504                GET_BE_U_4(msg_ptr.cfm_ltr->transaction_id),
505                GET_U_1(msg_ptr.cfm_ltr->ttl));
506 
507         ND_PRINT("\n\t  Replay-Action %s (%u)",
508                tok2str(cfm_ltr_replay_action_values,
509                        "Unknown",
510                        GET_U_1(msg_ptr.cfm_ltr->replay_action)),
511                GET_U_1(msg_ptr.cfm_ltr->replay_action));
512         break;
513 
514         /*
515          * No message decoder yet.
516          * Hexdump everything up until the start of the TLVs
517          */
518     case CFM_OPCODE_LBR:
519     case CFM_OPCODE_LBM:
520     default:
521         print_unknown_data(ndo, tptr, "\n\t  ",
522                            tlen -  first_tlv_offset);
523         break;
524     }
525 
526     tptr += first_tlv_offset;
527     tlen -= first_tlv_offset;
528 
529     while (tlen > 0) {
530         cfm_tlv_header = (const struct cfm_tlv_header_t *)tptr;
531 
532         /* Enough to read the tlv type ? */
533         cfm_tlv_type = GET_U_1(cfm_tlv_header->type);
534 
535         ND_PRINT("\n\t%s TLV (0x%02x)",
536                tok2str(cfm_tlv_values, "Unknown", cfm_tlv_type),
537                cfm_tlv_type);
538 
539         if (cfm_tlv_type == CFM_TLV_END) {
540             /* Length is "Not present if the Type field is 0." */
541             return;
542         }
543 
544         /* do we have the full tlv header ? */
545         if (tlen < sizeof(struct cfm_tlv_header_t))
546             goto tooshort;
547         ND_TCHECK_LEN(tptr, sizeof(struct cfm_tlv_header_t));
548         cfm_tlv_len=GET_BE_U_2(cfm_tlv_header->length);
549 
550         ND_PRINT(", length %u", cfm_tlv_len);
551 
552         tptr += sizeof(struct cfm_tlv_header_t);
553         tlen -= sizeof(struct cfm_tlv_header_t);
554         tlv_ptr = tptr;
555 
556         /* do we have the full tlv ? */
557         if (tlen < cfm_tlv_len)
558             goto tooshort;
559         ND_TCHECK_LEN(tptr, cfm_tlv_len);
560         hexdump = FALSE;
561 
562         switch(cfm_tlv_type) {
563         case CFM_TLV_PORT_STATUS:
564             if (cfm_tlv_len < 1) {
565                 ND_PRINT(" (too short, must be >= 1)");
566                 return;
567             }
568             ND_PRINT(", Status: %s (%u)",
569                    tok2str(cfm_tlv_port_status_values, "Unknown", GET_U_1(tptr)),
570                    GET_U_1(tptr));
571             break;
572 
573         case CFM_TLV_INTERFACE_STATUS:
574             if (cfm_tlv_len < 1) {
575                 ND_PRINT(" (too short, must be >= 1)");
576                 return;
577             }
578             ND_PRINT(", Status: %s (%u)",
579                    tok2str(cfm_tlv_interface_status_values, "Unknown", GET_U_1(tptr)),
580                    GET_U_1(tptr));
581             break;
582 
583         case CFM_TLV_PRIVATE:
584             if (cfm_tlv_len < 4) {
585                 ND_PRINT(" (too short, must be >= 4)");
586                 return;
587             }
588             ND_PRINT(", Vendor: %s (%u), Sub-Type %u",
589                    tok2str(oui_values,"Unknown", GET_BE_U_3(tptr)),
590                    GET_BE_U_3(tptr),
591                    GET_U_1(tptr + 3));
592             hexdump = TRUE;
593             break;
594 
595         case CFM_TLV_SENDER_ID:
596         {
597             u_int chassis_id_type, chassis_id_length;
598             u_int mgmt_addr_length;
599 
600             if (cfm_tlv_len < 1) {
601                 ND_PRINT(" (too short, must be >= 1)");
602                 goto next_tlv;
603             }
604 
605             /*
606              * Get the Chassis ID length and check it.
607              * IEEE 802.1Q-2014 Section 21.5.3.1
608              */
609             chassis_id_length = GET_U_1(tptr);
610             tptr++;
611             tlen--;
612             cfm_tlv_len--;
613 
614             if (chassis_id_length) {
615                 /*
616                  * IEEE 802.1Q-2014 Section 21.5.3.2: Chassis ID Subtype, references
617                  * IEEE 802.1AB-2005 Section 9.5.2.2, subsequently
618                  * IEEE 802.1AB-2016 Section 8.5.2.2: chassis ID subtype
619                  */
620                 if (cfm_tlv_len < 1) {
621                     ND_PRINT("\n\t  (TLV too short)");
622                     goto next_tlv;
623                 }
624                 chassis_id_type = GET_U_1(tptr);
625                 cfm_tlv_len--;
626                 ND_PRINT("\n\t  Chassis-ID Type %s (%u), Chassis-ID length %u",
627                        tok2str(cfm_tlv_senderid_chassisid_values,
628                                "Unknown",
629                                chassis_id_type),
630                        chassis_id_type,
631                        chassis_id_length);
632 
633                 if (cfm_tlv_len < chassis_id_length) {
634                     ND_PRINT("\n\t  (TLV too short)");
635                     goto next_tlv;
636                 }
637 
638                 /* IEEE 802.1Q-2014 Section 21.5.3.3: Chassis ID */
639                 switch (chassis_id_type) {
640                 case CFM_CHASSIS_ID_MAC_ADDRESS:
641                     if (chassis_id_length != MAC_ADDR_LEN) {
642                         ND_PRINT(" (invalid MAC address length)");
643                         hexdump = TRUE;
644                         break;
645                     }
646                     ND_PRINT("\n\t  MAC %s", GET_ETHERADDR_STRING(tptr + 1));
647                     break;
648 
649                 case CFM_CHASSIS_ID_NETWORK_ADDRESS:
650                     hexdump |= cfm_network_addr_print(ndo, tptr + 1, chassis_id_length);
651                     break;
652 
653                 case CFM_CHASSIS_ID_INTERFACE_NAME: /* fall through */
654                 case CFM_CHASSIS_ID_INTERFACE_ALIAS:
655                 case CFM_CHASSIS_ID_LOCAL:
656                 case CFM_CHASSIS_ID_CHASSIS_COMPONENT:
657                 case CFM_CHASSIS_ID_PORT_COMPONENT:
658                     nd_printjnp(ndo, tptr + 1, chassis_id_length);
659                     break;
660 
661                 default:
662                     hexdump = TRUE;
663                     break;
664                 }
665                 cfm_tlv_len -= chassis_id_length;
666 
667                 tptr += 1 + chassis_id_length;
668                 tlen -= 1 + chassis_id_length;
669             }
670 
671             /*
672              * Check if there is a Management Address.
673              * IEEE 802.1Q-2014 Section 21.5.3.4: Management Address Domain Length
674              * This and all subsequent fields are not present if the TLV length
675              * allows only the above fields.
676              */
677             if (cfm_tlv_len == 0) {
678                 /* No, there isn't; we're done. */
679                 break;
680             }
681 
682             /* Here mgmt_addr_length stands for the management domain length. */
683             mgmt_addr_length = GET_U_1(tptr);
684             tptr++;
685             tlen--;
686             cfm_tlv_len--;
687             ND_PRINT("\n\t  Management Address Domain Length %u", mgmt_addr_length);
688             if (mgmt_addr_length) {
689                 /* IEEE 802.1Q-2014 Section 21.5.3.5: Management Address Domain */
690                 if (cfm_tlv_len < mgmt_addr_length) {
691                     ND_PRINT("\n\t  (TLV too short)");
692                     goto next_tlv;
693                 }
694                 cfm_tlv_len -= mgmt_addr_length;
695                 /*
696                  * XXX - this is an OID; print it as such.
697                  */
698                 hex_print(ndo, "\n\t  Management Address Domain: ", tptr, mgmt_addr_length);
699                 tptr += mgmt_addr_length;
700                 tlen -= mgmt_addr_length;
701 
702                 /*
703                  * IEEE 802.1Q-2014 Section 21.5.3.6: Management Address Length
704                  * This field is present if Management Address Domain Length is not 0.
705                  */
706                 if (cfm_tlv_len < 1) {
707                     ND_PRINT(" (Management Address Length is missing)");
708                     hexdump = TRUE;
709                     break;
710                 }
711 
712                 /* Here mgmt_addr_length stands for the management address length. */
713                 mgmt_addr_length = GET_U_1(tptr);
714                 tptr++;
715                 tlen--;
716                 cfm_tlv_len--;
717                 ND_PRINT("\n\t  Management Address Length %u", mgmt_addr_length);
718                 if (mgmt_addr_length) {
719                     /* IEEE 802.1Q-2014 Section 21.5.3.7: Management Address */
720                     if (cfm_tlv_len < mgmt_addr_length) {
721                         ND_PRINT("\n\t  (TLV too short)");
722                         return;
723                     }
724                     cfm_tlv_len -= mgmt_addr_length;
725                     /*
726                      * XXX - this is a TransportDomain; print it as such.
727                      */
728                     hex_print(ndo, "\n\t  Management Address: ", tptr, mgmt_addr_length);
729                     tptr += mgmt_addr_length;
730                     tlen -= mgmt_addr_length;
731                 }
732             }
733             break;
734         }
735 
736             /*
737              * FIXME those are the defined TLVs that lack a decoder
738              * you are welcome to contribute code ;-)
739              */
740 
741         case CFM_TLV_DATA:
742         case CFM_TLV_REPLY_INGRESS:
743         case CFM_TLV_REPLY_EGRESS:
744         default:
745             hexdump = TRUE;
746             break;
747         }
748         /* do we want to see an additional hexdump ? */
749         if (hexdump || ndo->ndo_vflag > 1)
750             print_unknown_data(ndo, tlv_ptr, "\n\t  ", cfm_tlv_len);
751 
752 next_tlv:
753         tptr+=cfm_tlv_len;
754         tlen-=cfm_tlv_len;
755     }
756     return;
757 
758 tooshort:
759     ND_PRINT("\n\t\t packet is too short");
760     return;
761 
762 trunc:
763     nd_print_trunc(ndo);
764 }
765