xref: /netbsd-src/external/bsd/tcpdump/dist/print-cfm.c (revision 3117ece4fc4a4ca4489ba793710b60b0d26bab6c)
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 1.11 2024/09/02 16:15:30 christos Exp $");
23 #endif
24 
25 #include <config.h>
26 
27 #include "netdissect-stdinc.h"
28 
29 #include "netdissect.h"
30 #include "extract.h"
31 #include "addrtoname.h"
32 #include "oui.h"
33 #include "af.h"
34 
35 
36 struct cfm_common_header_t {
37     nd_uint8_t mdlevel_version;
38     nd_uint8_t opcode;
39     nd_uint8_t flags;
40     nd_uint8_t first_tlv_offset;
41 };
42 
43 #define	CFM_VERSION 0
44 #define CFM_EXTRACT_VERSION(x) ((x)&0x1f)
45 #define CFM_EXTRACT_MD_LEVEL(x) (((x)&0xe0)>>5)
46 
47 #define	CFM_OPCODE_CCM 1
48 #define	CFM_OPCODE_LBR 2
49 #define	CFM_OPCODE_LBM 3
50 #define	CFM_OPCODE_LTR 4
51 #define	CFM_OPCODE_LTM 5
52 
53 static const struct tok cfm_opcode_values[] = {
54     { CFM_OPCODE_CCM, "Continuity Check Message"},
55     { CFM_OPCODE_LBR, "Loopback Reply"},
56     { CFM_OPCODE_LBM, "Loopback Message"},
57     { CFM_OPCODE_LTR, "Linktrace Reply"},
58     { CFM_OPCODE_LTM, "Linktrace Message"},
59     { 0, NULL}
60 };
61 
62 /*
63  * Message Formats.
64  */
65 struct cfm_ccm_t {
66     nd_uint32_t sequence;
67     nd_uint16_t ma_epi;
68     nd_byte     names[48];
69     nd_byte     itu_t_y_1731[16];
70 };
71 
72 /*
73  * Timer Bases for the CCM Interval field.
74  * Expressed in units of seconds.
75  */
76 static const float ccm_interval_base[8] = {0.0f, 0.003333f, 0.01f, 0.1f, 1.0f, 10.0f, 60.0f, 600.0f};
77 #define CCM_INTERVAL_MIN_MULTIPLIER 3.25
78 #define CCM_INTERVAL_MAX_MULTIPLIER 3.5
79 
80 #define CFM_CCM_RDI_FLAG 0x80
81 #define CFM_EXTRACT_CCM_INTERVAL(x) ((x)&0x07)
82 
83 #define CFM_CCM_MD_FORMAT_8021 0
84 #define CFM_CCM_MD_FORMAT_NONE 1
85 #define CFM_CCM_MD_FORMAT_DNS  2
86 #define CFM_CCM_MD_FORMAT_MAC  3
87 #define CFM_CCM_MD_FORMAT_CHAR 4
88 
89 static const struct tok cfm_md_nameformat_values[] = {
90     { CFM_CCM_MD_FORMAT_8021, "IEEE 802.1"},
91     { CFM_CCM_MD_FORMAT_NONE, "No MD Name present"},
92     { CFM_CCM_MD_FORMAT_DNS, "DNS string"},
93     { CFM_CCM_MD_FORMAT_MAC, "MAC + 16Bit Integer"},
94     { CFM_CCM_MD_FORMAT_CHAR, "Character string"},
95     { 0, NULL}
96 };
97 
98 #define CFM_CCM_MA_FORMAT_8021 0
99 #define CFM_CCM_MA_FORMAT_VID  1
100 #define CFM_CCM_MA_FORMAT_CHAR 2
101 #define CFM_CCM_MA_FORMAT_INT  3
102 #define CFM_CCM_MA_FORMAT_VPN  4
103 
104 static const struct tok cfm_ma_nameformat_values[] = {
105     { CFM_CCM_MA_FORMAT_8021, "IEEE 802.1"},
106     { CFM_CCM_MA_FORMAT_VID, "Primary VID"},
107     { CFM_CCM_MA_FORMAT_CHAR, "Character string"},
108     { CFM_CCM_MA_FORMAT_INT, "16Bit Integer"},
109     { CFM_CCM_MA_FORMAT_VPN, "RFC2685 VPN-ID"},
110     { 0, NULL}
111 };
112 
113 struct cfm_lbm_t {
114     nd_uint32_t transaction_id;
115 };
116 
117 struct cfm_ltm_t {
118     nd_uint32_t transaction_id;
119     nd_uint8_t  ttl;
120     nd_mac_addr original_mac;
121     nd_mac_addr target_mac;
122 };
123 
124 static const struct tok cfm_ltm_flag_values[] = {
125     { 0x80, "Use Forwarding-DB only"},
126     { 0, NULL}
127 };
128 
129 struct cfm_ltr_t {
130     nd_uint32_t transaction_id;
131     nd_uint8_t  ttl;
132     nd_uint8_t  replay_action;
133 };
134 
135 static const struct tok cfm_ltr_flag_values[] = {
136     { 0x80, "UseFDB Only"},
137     { 0x40, "FwdYes"},
138     { 0x20, "Terminal MEP"},
139     { 0, NULL}
140 };
141 
142 static const struct tok cfm_ltr_replay_action_values[] = {
143     { 1, "Exact Match"},
144     { 2, "Filtering DB"},
145     { 3, "MIP CCM DB"},
146     { 0, NULL}
147 };
148 
149 
150 #define CFM_TLV_END 0
151 #define CFM_TLV_SENDER_ID 1
152 #define CFM_TLV_PORT_STATUS 2
153 #define CFM_TLV_INTERFACE_STATUS 3
154 #define CFM_TLV_DATA 4
155 #define CFM_TLV_REPLY_INGRESS 5
156 #define CFM_TLV_REPLY_EGRESS 6
157 #define CFM_TLV_PRIVATE 31
158 
159 static const struct tok cfm_tlv_values[] = {
160     { CFM_TLV_END, "End"},
161     { CFM_TLV_SENDER_ID, "Sender ID"},
162     { CFM_TLV_PORT_STATUS, "Port status"},
163     { CFM_TLV_INTERFACE_STATUS, "Interface status"},
164     { CFM_TLV_DATA, "Data"},
165     { CFM_TLV_REPLY_INGRESS, "Reply Ingress"},
166     { CFM_TLV_REPLY_EGRESS, "Reply Egress"},
167     { CFM_TLV_PRIVATE, "Organization Specific"},
168     { 0, NULL}
169 };
170 
171 /*
172  * TLVs
173  */
174 
175 struct cfm_tlv_header_t {
176     nd_uint8_t  type;
177     nd_uint16_t length;
178 };
179 
180 /* FIXME define TLV formats */
181 
182 static const struct tok cfm_tlv_port_status_values[] = {
183     { 1, "Blocked"},
184     { 2, "Up"},
185     { 0, NULL}
186 };
187 
188 static const struct tok cfm_tlv_interface_status_values[] = {
189     { 1, "Up"},
190     { 2, "Down"},
191     { 3, "Testing"},
192     { 5, "Dormant"},
193     { 6, "not present"},
194     { 7, "lower Layer down"},
195     { 0, NULL}
196 };
197 
198 #define CFM_CHASSIS_ID_CHASSIS_COMPONENT 1
199 #define CFM_CHASSIS_ID_INTERFACE_ALIAS 2
200 #define CFM_CHASSIS_ID_PORT_COMPONENT 3
201 #define CFM_CHASSIS_ID_MAC_ADDRESS 4
202 #define CFM_CHASSIS_ID_NETWORK_ADDRESS 5
203 #define CFM_CHASSIS_ID_INTERFACE_NAME 6
204 #define CFM_CHASSIS_ID_LOCAL 7
205 
206 static const struct tok cfm_tlv_senderid_chassisid_values[] = {
207     { 0, "Reserved"},
208     { CFM_CHASSIS_ID_CHASSIS_COMPONENT, "Chassis component"},
209     { CFM_CHASSIS_ID_INTERFACE_ALIAS, "Interface alias"},
210     { CFM_CHASSIS_ID_PORT_COMPONENT, "Port component"},
211     { CFM_CHASSIS_ID_MAC_ADDRESS, "MAC address"},
212     { CFM_CHASSIS_ID_NETWORK_ADDRESS, "Network address"},
213     { CFM_CHASSIS_ID_INTERFACE_NAME, "Interface name"},
214     { CFM_CHASSIS_ID_LOCAL, "Locally assigned"},
215     { 0, NULL}
216 };
217 
218 
219 static int
220 cfm_network_addr_print(netdissect_options *ndo,
221                        const u_char *tptr, const u_int length)
222 {
223     u_int network_addr_type;
224     u_int hexdump =  FALSE;
225 
226     /*
227      * Although AFIs are typically 2 octets wide,
228      * 802.1ab specifies that this field width
229      * is only one octet.
230      */
231     if (length < 1) {
232         ND_PRINT("\n\t  Network Address Type (invalid, no data");
233         return hexdump;
234     }
235     /* The calling function must make any due ND_TCHECK calls. */
236     network_addr_type = GET_U_1(tptr);
237     ND_PRINT("\n\t  Network Address Type %s (%u)",
238            tok2str(af_values, "Unknown", network_addr_type),
239            network_addr_type);
240 
241     /*
242      * Resolve the passed in Address.
243      */
244     switch(network_addr_type) {
245     case AFNUM_INET:
246         if (length != 1 + 4) {
247             ND_PRINT("(invalid IPv4 address length %u)", length - 1);
248             hexdump = TRUE;
249             break;
250         }
251         ND_PRINT(", %s", GET_IPADDR_STRING(tptr + 1));
252         break;
253 
254     case AFNUM_INET6:
255         if (length != 1 + 16) {
256             ND_PRINT("(invalid IPv6 address length %u)", length - 1);
257             hexdump = TRUE;
258             break;
259         }
260         ND_PRINT(", %s", GET_IP6ADDR_STRING(tptr + 1));
261         break;
262 
263     default:
264         hexdump = TRUE;
265         break;
266     }
267 
268     return hexdump;
269 }
270 
271 void
272 cfm_print(netdissect_options *ndo,
273           const u_char *pptr, u_int length)
274 {
275     const struct cfm_common_header_t *cfm_common_header;
276     uint8_t mdlevel_version, opcode, flags, first_tlv_offset;
277     const struct cfm_tlv_header_t *cfm_tlv_header;
278     const uint8_t *tptr, *tlv_ptr;
279     const uint8_t *namesp;
280     u_int names_data_remaining;
281     uint8_t md_nameformat, md_namelength;
282     const uint8_t *md_name;
283     uint8_t ma_nameformat, ma_namelength;
284     const uint8_t *ma_name;
285     u_int hexdump, tlen, cfm_tlv_len, cfm_tlv_type, ccm_interval;
286 
287 
288     union {
289         const struct cfm_ccm_t *cfm_ccm;
290         const struct cfm_lbm_t *cfm_lbm;
291         const struct cfm_ltm_t *cfm_ltm;
292         const struct cfm_ltr_t *cfm_ltr;
293     } msg_ptr;
294 
295     ndo->ndo_protocol = "cfm";
296     tptr=pptr;
297     cfm_common_header = (const struct cfm_common_header_t *)pptr;
298     if (length < sizeof(*cfm_common_header))
299         goto tooshort;
300     ND_TCHECK_SIZE(cfm_common_header);
301 
302     /*
303      * Sanity checking of the header.
304      */
305     mdlevel_version = GET_U_1(cfm_common_header->mdlevel_version);
306     if (CFM_EXTRACT_VERSION(mdlevel_version) != CFM_VERSION) {
307 	ND_PRINT("CFMv%u not supported, length %u",
308                CFM_EXTRACT_VERSION(mdlevel_version), length);
309 	return;
310     }
311 
312     opcode = GET_U_1(cfm_common_header->opcode);
313     ND_PRINT("CFMv%u %s, MD Level %u, length %u",
314            CFM_EXTRACT_VERSION(mdlevel_version),
315            tok2str(cfm_opcode_values, "unknown (%u)", opcode),
316            CFM_EXTRACT_MD_LEVEL(mdlevel_version),
317            length);
318 
319     /*
320      * In non-verbose mode just print the opcode and md-level.
321      */
322     if (ndo->ndo_vflag < 1) {
323         return;
324     }
325 
326     flags = GET_U_1(cfm_common_header->flags);
327     first_tlv_offset = GET_U_1(cfm_common_header->first_tlv_offset);
328     ND_PRINT("\n\tFirst TLV offset %u", first_tlv_offset);
329 
330     tptr += sizeof(struct cfm_common_header_t);
331     tlen = length - sizeof(struct cfm_common_header_t);
332 
333     /*
334      * Sanity check the first TLV offset.
335      */
336     if (first_tlv_offset > tlen) {
337         ND_PRINT(" (too large, must be <= %u)", tlen);
338         return;
339     }
340 
341     switch (opcode) {
342     case CFM_OPCODE_CCM:
343         msg_ptr.cfm_ccm = (const struct cfm_ccm_t *)tptr;
344         if (first_tlv_offset < sizeof(*msg_ptr.cfm_ccm)) {
345             ND_PRINT(" (too small 1, must be >= %zu)",
346                      sizeof(*msg_ptr.cfm_ccm));
347             return;
348         }
349         if (tlen < sizeof(*msg_ptr.cfm_ccm))
350             goto tooshort;
351         ND_TCHECK_SIZE(msg_ptr.cfm_ccm);
352 
353         ccm_interval = CFM_EXTRACT_CCM_INTERVAL(flags);
354         ND_PRINT(", Flags [CCM Interval %u%s]",
355                ccm_interval,
356                flags & CFM_CCM_RDI_FLAG ?
357                ", RDI" : "");
358 
359         /*
360          * Resolve the CCM interval field.
361          */
362         if (ccm_interval) {
363             ND_PRINT("\n\t  CCM Interval %.3fs"
364                    ", min CCM Lifetime %.3fs, max CCM Lifetime %.3fs",
365                    ccm_interval_base[ccm_interval],
366                    ccm_interval_base[ccm_interval] * CCM_INTERVAL_MIN_MULTIPLIER,
367                    ccm_interval_base[ccm_interval] * CCM_INTERVAL_MAX_MULTIPLIER);
368         }
369 
370         ND_PRINT("\n\t  Sequence Number 0x%08x, MA-End-Point-ID 0x%04x",
371                GET_BE_U_4(msg_ptr.cfm_ccm->sequence),
372                GET_BE_U_2(msg_ptr.cfm_ccm->ma_epi));
373 
374         namesp = msg_ptr.cfm_ccm->names;
375         names_data_remaining = sizeof(msg_ptr.cfm_ccm->names);
376 
377         /*
378          * Resolve the MD fields.
379          */
380         md_nameformat = GET_U_1(namesp);
381         namesp++;
382         names_data_remaining--;  /* We know this is != 0 */
383         if (md_nameformat != CFM_CCM_MD_FORMAT_NONE) {
384             md_namelength = GET_U_1(namesp);
385             namesp++;
386             names_data_remaining--; /* We know this is !=0 */
387             ND_PRINT("\n\t  MD Name Format %s (%u), MD Name length %u",
388                    tok2str(cfm_md_nameformat_values, "Unknown",
389                            md_nameformat),
390                    md_nameformat,
391                    md_namelength);
392 
393             /*
394              * -3 for the MA short name format and length and one byte
395              * of MA short name.
396              */
397             if (md_namelength > names_data_remaining - 3) {
398                 ND_PRINT(" (too large, must be <= %u)", names_data_remaining - 2);
399                 return;
400             }
401 
402             md_name = namesp;
403             ND_PRINT("\n\t  MD Name: ");
404             switch (md_nameformat) {
405             case CFM_CCM_MD_FORMAT_DNS:
406             case CFM_CCM_MD_FORMAT_CHAR:
407                 nd_printjnp(ndo, md_name, md_namelength);
408                 break;
409 
410             case CFM_CCM_MD_FORMAT_MAC:
411                 if (md_namelength == MAC_ADDR_LEN) {
412                     ND_PRINT("\n\t  MAC %s", GET_ETHERADDR_STRING(md_name));
413                 } else {
414                     ND_PRINT("\n\t  MAC (length invalid)");
415                 }
416                 break;
417 
418                 /* FIXME add printers for those MD formats - hexdump for now */
419             case CFM_CCM_MA_FORMAT_8021:
420             default:
421                 print_unknown_data(ndo, md_name, "\n\t    ",
422                                    md_namelength);
423             }
424             namesp += md_namelength;
425             names_data_remaining -= md_namelength;
426         } else {
427             ND_PRINT("\n\t  MD Name Format %s (%u)",
428                    tok2str(cfm_md_nameformat_values, "Unknown",
429                            md_nameformat),
430                    md_nameformat);
431         }
432 
433 
434         /*
435          * Resolve the MA fields.
436          */
437         ma_nameformat = GET_U_1(namesp);
438         namesp++;
439         names_data_remaining--; /* We know this is != 0 */
440         ma_namelength = GET_U_1(namesp);
441         namesp++;
442         names_data_remaining--; /* We know this is != 0 */
443         ND_PRINT("\n\t  MA Name-Format %s (%u), MA name length %u",
444                tok2str(cfm_ma_nameformat_values, "Unknown",
445                        ma_nameformat),
446                ma_nameformat,
447                ma_namelength);
448 
449         if (ma_namelength > names_data_remaining) {
450             ND_PRINT(" (too large, must be <= %u)", names_data_remaining);
451             return;
452         }
453 
454         ma_name = namesp;
455         ND_PRINT("\n\t  MA Name: ");
456         switch (ma_nameformat) {
457         case CFM_CCM_MA_FORMAT_CHAR:
458             nd_printjnp(ndo, ma_name, ma_namelength);
459             break;
460 
461             /* FIXME add printers for those MA formats - hexdump for now */
462         case CFM_CCM_MA_FORMAT_8021:
463         case CFM_CCM_MA_FORMAT_VID:
464         case CFM_CCM_MA_FORMAT_INT:
465         case CFM_CCM_MA_FORMAT_VPN:
466         default:
467             print_unknown_data(ndo, ma_name, "\n\t    ", ma_namelength);
468         }
469         break;
470 
471     case CFM_OPCODE_LTM:
472         msg_ptr.cfm_ltm = (const struct cfm_ltm_t *)tptr;
473         if (first_tlv_offset < sizeof(*msg_ptr.cfm_ltm)) {
474             ND_PRINT(" (too small 4, must be >= %zu)",
475                      sizeof(*msg_ptr.cfm_ltm));
476             return;
477         }
478         if (tlen < sizeof(*msg_ptr.cfm_ltm))
479             goto tooshort;
480         ND_TCHECK_SIZE(msg_ptr.cfm_ltm);
481 
482         ND_PRINT(", Flags [%s]",
483                bittok2str(cfm_ltm_flag_values, "none", flags));
484 
485         ND_PRINT("\n\t  Transaction-ID 0x%08x, ttl %u",
486                GET_BE_U_4(msg_ptr.cfm_ltm->transaction_id),
487                GET_U_1(msg_ptr.cfm_ltm->ttl));
488 
489         ND_PRINT("\n\t  Original-MAC %s, Target-MAC %s",
490                GET_ETHERADDR_STRING(msg_ptr.cfm_ltm->original_mac),
491                GET_ETHERADDR_STRING(msg_ptr.cfm_ltm->target_mac));
492         break;
493 
494     case CFM_OPCODE_LTR:
495         msg_ptr.cfm_ltr = (const struct cfm_ltr_t *)tptr;
496         if (first_tlv_offset < sizeof(*msg_ptr.cfm_ltr)) {
497             ND_PRINT(" (too small 5, must be >= %zu)",
498                      sizeof(*msg_ptr.cfm_ltr));
499             return;
500         }
501         if (tlen < sizeof(*msg_ptr.cfm_ltr))
502             goto tooshort;
503         ND_TCHECK_SIZE(msg_ptr.cfm_ltr);
504 
505         ND_PRINT(", Flags [%s]",
506                bittok2str(cfm_ltr_flag_values, "none", flags));
507 
508         ND_PRINT("\n\t  Transaction-ID 0x%08x, ttl %u",
509                GET_BE_U_4(msg_ptr.cfm_ltr->transaction_id),
510                GET_U_1(msg_ptr.cfm_ltr->ttl));
511 
512         ND_PRINT("\n\t  Replay-Action %s (%u)",
513                tok2str(cfm_ltr_replay_action_values,
514                        "Unknown",
515                        GET_U_1(msg_ptr.cfm_ltr->replay_action)),
516                GET_U_1(msg_ptr.cfm_ltr->replay_action));
517         break;
518 
519         /*
520          * No message decoder yet.
521          * Hexdump everything up until the start of the TLVs
522          */
523     case CFM_OPCODE_LBR:
524     case CFM_OPCODE_LBM:
525     default:
526         print_unknown_data(ndo, tptr, "\n\t  ",
527                            tlen -  first_tlv_offset);
528         break;
529     }
530 
531     tptr += first_tlv_offset;
532     tlen -= first_tlv_offset;
533 
534     while (tlen > 0) {
535         cfm_tlv_header = (const struct cfm_tlv_header_t *)tptr;
536 
537         /* Enough to read the tlv type ? */
538         cfm_tlv_type = GET_U_1(cfm_tlv_header->type);
539 
540         ND_PRINT("\n\t%s TLV (0x%02x)",
541                tok2str(cfm_tlv_values, "Unknown", cfm_tlv_type),
542                cfm_tlv_type);
543 
544         if (cfm_tlv_type == CFM_TLV_END) {
545             /* Length is "Not present if the Type field is 0." */
546             return;
547         }
548 
549         /* do we have the full tlv header ? */
550         if (tlen < sizeof(struct cfm_tlv_header_t))
551             goto tooshort;
552         ND_TCHECK_LEN(tptr, sizeof(struct cfm_tlv_header_t));
553         cfm_tlv_len=GET_BE_U_2(cfm_tlv_header->length);
554 
555         ND_PRINT(", length %u", cfm_tlv_len);
556 
557         tptr += sizeof(struct cfm_tlv_header_t);
558         tlen -= sizeof(struct cfm_tlv_header_t);
559         tlv_ptr = tptr;
560 
561         /* do we have the full tlv ? */
562         if (tlen < cfm_tlv_len)
563             goto tooshort;
564         ND_TCHECK_LEN(tptr, cfm_tlv_len);
565         hexdump = FALSE;
566 
567         switch(cfm_tlv_type) {
568         case CFM_TLV_PORT_STATUS:
569             if (cfm_tlv_len < 1) {
570                 ND_PRINT(" (too short, must be >= 1)");
571                 return;
572             }
573             ND_PRINT(", Status: %s (%u)",
574                    tok2str(cfm_tlv_port_status_values, "Unknown", GET_U_1(tptr)),
575                    GET_U_1(tptr));
576             break;
577 
578         case CFM_TLV_INTERFACE_STATUS:
579             if (cfm_tlv_len < 1) {
580                 ND_PRINT(" (too short, must be >= 1)");
581                 return;
582             }
583             ND_PRINT(", Status: %s (%u)",
584                    tok2str(cfm_tlv_interface_status_values, "Unknown", GET_U_1(tptr)),
585                    GET_U_1(tptr));
586             break;
587 
588         case CFM_TLV_PRIVATE:
589             if (cfm_tlv_len < 4) {
590                 ND_PRINT(" (too short, must be >= 4)");
591                 return;
592             }
593             ND_PRINT(", Vendor: %s (%u), Sub-Type %u",
594                    tok2str(oui_values,"Unknown", GET_BE_U_3(tptr)),
595                    GET_BE_U_3(tptr),
596                    GET_U_1(tptr + 3));
597             hexdump = TRUE;
598             break;
599 
600         case CFM_TLV_SENDER_ID:
601         {
602             u_int chassis_id_type, chassis_id_length;
603             u_int mgmt_addr_length;
604 
605             if (cfm_tlv_len < 1) {
606                 ND_PRINT(" (too short, must be >= 1)");
607                 goto next_tlv;
608             }
609 
610             /*
611              * Get the Chassis ID length and check it.
612              * IEEE 802.1Q-2014 Section 21.5.3.1
613              */
614             chassis_id_length = GET_U_1(tptr);
615             tptr++;
616             tlen--;
617             cfm_tlv_len--;
618 
619             if (chassis_id_length) {
620                 /*
621                  * IEEE 802.1Q-2014 Section 21.5.3.2: Chassis ID Subtype, references
622                  * IEEE 802.1AB-2005 Section 9.5.2.2, subsequently
623                  * IEEE 802.1AB-2016 Section 8.5.2.2: chassis ID subtype
624                  */
625                 if (cfm_tlv_len < 1) {
626                     ND_PRINT("\n\t  (TLV too short)");
627                     goto next_tlv;
628                 }
629                 chassis_id_type = GET_U_1(tptr);
630                 cfm_tlv_len--;
631                 ND_PRINT("\n\t  Chassis-ID Type %s (%u), Chassis-ID length %u",
632                        tok2str(cfm_tlv_senderid_chassisid_values,
633                                "Unknown",
634                                chassis_id_type),
635                        chassis_id_type,
636                        chassis_id_length);
637 
638                 if (cfm_tlv_len < chassis_id_length) {
639                     ND_PRINT("\n\t  (TLV too short)");
640                     goto next_tlv;
641                 }
642 
643                 /* IEEE 802.1Q-2014 Section 21.5.3.3: Chassis ID */
644                 switch (chassis_id_type) {
645                 case CFM_CHASSIS_ID_MAC_ADDRESS:
646                     if (chassis_id_length != MAC_ADDR_LEN) {
647                         ND_PRINT(" (invalid MAC address length)");
648                         hexdump = TRUE;
649                         break;
650                     }
651                     ND_PRINT("\n\t  MAC %s", GET_ETHERADDR_STRING(tptr + 1));
652                     break;
653 
654                 case CFM_CHASSIS_ID_NETWORK_ADDRESS:
655                     hexdump |= cfm_network_addr_print(ndo, tptr + 1, chassis_id_length);
656                     break;
657 
658                 case CFM_CHASSIS_ID_INTERFACE_NAME: /* fall through */
659                 case CFM_CHASSIS_ID_INTERFACE_ALIAS:
660                 case CFM_CHASSIS_ID_LOCAL:
661                 case CFM_CHASSIS_ID_CHASSIS_COMPONENT:
662                 case CFM_CHASSIS_ID_PORT_COMPONENT:
663                     nd_printjnp(ndo, tptr + 1, chassis_id_length);
664                     break;
665 
666                 default:
667                     hexdump = TRUE;
668                     break;
669                 }
670                 cfm_tlv_len -= chassis_id_length;
671 
672                 tptr += 1 + chassis_id_length;
673                 tlen -= 1 + chassis_id_length;
674             }
675 
676             /*
677              * Check if there is a Management Address.
678              * IEEE 802.1Q-2014 Section 21.5.3.4: Management Address Domain Length
679              * This and all subsequent fields are not present if the TLV length
680              * allows only the above fields.
681              */
682             if (cfm_tlv_len == 0) {
683                 /* No, there isn't; we're done. */
684                 break;
685             }
686 
687             /* Here mgmt_addr_length stands for the management domain length. */
688             mgmt_addr_length = GET_U_1(tptr);
689             tptr++;
690             tlen--;
691             cfm_tlv_len--;
692             ND_PRINT("\n\t  Management Address Domain Length %u", mgmt_addr_length);
693             if (mgmt_addr_length) {
694                 /* IEEE 802.1Q-2014 Section 21.5.3.5: Management Address Domain */
695                 if (cfm_tlv_len < mgmt_addr_length) {
696                     ND_PRINT("\n\t  (TLV too short)");
697                     goto next_tlv;
698                 }
699                 cfm_tlv_len -= mgmt_addr_length;
700                 /*
701                  * XXX - this is an OID; print it as such.
702                  */
703                 hex_print(ndo, "\n\t  Management Address Domain: ", tptr, mgmt_addr_length);
704                 tptr += mgmt_addr_length;
705                 tlen -= mgmt_addr_length;
706 
707                 /*
708                  * IEEE 802.1Q-2014 Section 21.5.3.6: Management Address Length
709                  * This field is present if Management Address Domain Length is not 0.
710                  */
711                 if (cfm_tlv_len < 1) {
712                     ND_PRINT(" (Management Address Length is missing)");
713                     hexdump = TRUE;
714                     break;
715                 }
716 
717                 /* Here mgmt_addr_length stands for the management address length. */
718                 mgmt_addr_length = GET_U_1(tptr);
719                 tptr++;
720                 tlen--;
721                 cfm_tlv_len--;
722                 ND_PRINT("\n\t  Management Address Length %u", mgmt_addr_length);
723                 if (mgmt_addr_length) {
724                     /* IEEE 802.1Q-2014 Section 21.5.3.7: Management Address */
725                     if (cfm_tlv_len < mgmt_addr_length) {
726                         ND_PRINT("\n\t  (TLV too short)");
727                         return;
728                     }
729                     cfm_tlv_len -= mgmt_addr_length;
730                     /*
731                      * XXX - this is a TransportDomain; print it as such.
732                      */
733                     hex_print(ndo, "\n\t  Management Address: ", tptr, mgmt_addr_length);
734                     tptr += mgmt_addr_length;
735                     tlen -= mgmt_addr_length;
736                 }
737             }
738             break;
739         }
740 
741             /*
742              * FIXME those are the defined TLVs that lack a decoder
743              * you are welcome to contribute code ;-)
744              */
745 
746         case CFM_TLV_DATA:
747         case CFM_TLV_REPLY_INGRESS:
748         case CFM_TLV_REPLY_EGRESS:
749         default:
750             hexdump = TRUE;
751             break;
752         }
753         /* do we want to see an additional hexdump ? */
754         if (hexdump || ndo->ndo_vflag > 1)
755             print_unknown_data(ndo, tlv_ptr, "\n\t  ", cfm_tlv_len);
756 
757 next_tlv:
758         tptr+=cfm_tlv_len;
759         tlen-=cfm_tlv_len;
760     }
761     return;
762 
763 tooshort:
764     ND_PRINT("\n\t\t packet is too short");
765     return;
766 
767 trunc:
768     nd_print_trunc(ndo);
769 }
770