xref: /freebsd/contrib/tcpdump/print-cfm.c (revision b9f654b163bce26de79705e77b872427c9f2afa1)
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 #ifdef HAVE_CONFIG_H
21 #include "config.h"
22 #endif
23 
24 #include <netdissect-stdinc.h>
25 
26 #include <stdio.h>
27 
28 #include "netdissect.h"
29 #include "extract.h"
30 #include "ether.h"
31 #include "addrtoname.h"
32 #include "oui.h"
33 #include "af.h"
34 
35 struct cfm_common_header_t {
36     uint8_t mdlevel_version;
37     uint8_t opcode;
38     uint8_t flags;
39     uint8_t first_tlv_offset;
40 };
41 
42 #define	CFM_VERSION 0
43 #define CFM_EXTRACT_VERSION(x) (((x)&0x1f))
44 #define CFM_EXTRACT_MD_LEVEL(x) (((x)&0xe0)>>5)
45 
46 #define	CFM_OPCODE_CCM 1
47 #define	CFM_OPCODE_LBR 2
48 #define	CFM_OPCODE_LBM 3
49 #define	CFM_OPCODE_LTR 4
50 #define	CFM_OPCODE_LTM 5
51 
52 static const struct tok cfm_opcode_values[] = {
53     { CFM_OPCODE_CCM, "Continouity Check Message"},
54     { CFM_OPCODE_LBR, "Loopback Reply"},
55     { CFM_OPCODE_LBM, "Loopback Message"},
56     { CFM_OPCODE_LTR, "Linktrace Reply"},
57     { CFM_OPCODE_LTM, "Linktrace Message"},
58     { 0, NULL}
59 };
60 
61 /*
62  * Message Formats.
63  */
64 struct cfm_ccm_t {
65     uint8_t sequence[4];
66     uint8_t ma_epi[2];
67     uint8_t names[48];
68     uint8_t itu_t_y_1731[16];
69 };
70 
71 /*
72  * Timer Bases for the CCM Interval field.
73  * Expressed in units of seconds.
74  */
75 static const float ccm_interval_base[8] = {0, 0.003333, 0.01, 0.1, 1, 10, 60, 600};
76 #define CCM_INTERVAL_MIN_MULTIPLIER 3.25
77 #define CCM_INTERVAL_MAX_MULTIPLIER 3.5
78 
79 #define CFM_CCM_RDI_FLAG 0x80
80 #define CFM_EXTRACT_CCM_INTERVAL(x) (((x)&0x07))
81 
82 #define CFM_CCM_MD_FORMAT_8021 0
83 #define CFM_CCM_MD_FORMAT_NONE 1
84 #define CFM_CCM_MD_FORMAT_DNS  2
85 #define CFM_CCM_MD_FORMAT_MAC  3
86 #define CFM_CCM_MD_FORMAT_CHAR 4
87 
88 static const struct tok cfm_md_nameformat_values[] = {
89     { CFM_CCM_MD_FORMAT_8021, "IEEE 802.1"},
90     { CFM_CCM_MD_FORMAT_NONE, "No MD Name present"},
91     { CFM_CCM_MD_FORMAT_DNS, "DNS string"},
92     { CFM_CCM_MD_FORMAT_MAC, "MAC + 16Bit Integer"},
93     { CFM_CCM_MD_FORMAT_CHAR, "Character string"},
94     { 0, NULL}
95 };
96 
97 #define CFM_CCM_MA_FORMAT_8021 0
98 #define CFM_CCM_MA_FORMAT_VID  1
99 #define CFM_CCM_MA_FORMAT_CHAR 2
100 #define CFM_CCM_MA_FORMAT_INT  3
101 #define CFM_CCM_MA_FORMAT_VPN  4
102 
103 static const struct tok cfm_ma_nameformat_values[] = {
104     { CFM_CCM_MA_FORMAT_8021, "IEEE 802.1"},
105     { CFM_CCM_MA_FORMAT_VID, "Primary VID"},
106     { CFM_CCM_MA_FORMAT_CHAR, "Character string"},
107     { CFM_CCM_MA_FORMAT_INT, "16Bit Integer"},
108     { CFM_CCM_MA_FORMAT_VPN, "RFC2685 VPN-ID"},
109     { 0, NULL}
110 };
111 
112 struct cfm_lbm_t {
113     uint8_t transaction_id[4];
114 };
115 
116 struct cfm_ltm_t {
117     uint8_t transaction_id[4];
118     uint8_t ttl;
119     uint8_t original_mac[ETHER_ADDR_LEN];
120     uint8_t target_mac[ETHER_ADDR_LEN];
121 };
122 
123 static const struct tok cfm_ltm_flag_values[] = {
124     { 0x80, "Use Forwarding-DB only"},
125     { 0, NULL}
126 };
127 
128 struct cfm_ltr_t {
129     uint8_t transaction_id[4];
130     uint8_t ttl;
131     uint8_t replay_action;
132 };
133 
134 static const struct tok cfm_ltr_flag_values[] = {
135     { 0x80, "UseFDB Only"},
136     { 0x40, "FwdYes"},
137     { 0x20, "Terminal MEP"},
138     { 0, NULL}
139 };
140 
141 static const struct tok cfm_ltr_replay_action_values[] = {
142     { 1, "Exact Match"},
143     { 2, "Filtering DB"},
144     { 3, "MIP CCM DB"},
145     { 0, NULL}
146 };
147 
148 
149 #define CFM_TLV_END 0
150 #define CFM_TLV_SENDER_ID 1
151 #define CFM_TLV_PORT_STATUS 2
152 #define CFM_TLV_INTERFACE_STATUS 3
153 #define CFM_TLV_DATA 4
154 #define CFM_TLV_REPLY_INGRESS 5
155 #define CFM_TLV_REPLY_EGRESS 6
156 #define CFM_TLV_PRIVATE 31
157 
158 static const struct tok cfm_tlv_values[] = {
159     { CFM_TLV_END, "End"},
160     { CFM_TLV_SENDER_ID, "Sender ID"},
161     { CFM_TLV_PORT_STATUS, "Port status"},
162     { CFM_TLV_INTERFACE_STATUS, "Interface status"},
163     { CFM_TLV_DATA, "Data"},
164     { CFM_TLV_REPLY_INGRESS, "Reply Ingress"},
165     { CFM_TLV_REPLY_EGRESS, "Reply Egress"},
166     { CFM_TLV_PRIVATE, "Organization Specific"},
167     { 0, NULL}
168 };
169 
170 /*
171  * TLVs
172  */
173 
174 struct cfm_tlv_header_t {
175     uint8_t type;
176     uint8_t length[2];
177 };
178 
179 /* FIXME define TLV formats */
180 
181 static const struct tok cfm_tlv_port_status_values[] = {
182     { 1, "Blocked"},
183     { 2, "Up"},
184     { 0, NULL}
185 };
186 
187 static const struct tok cfm_tlv_interface_status_values[] = {
188     { 1, "Up"},
189     { 2, "Down"},
190     { 3, "Testing"},
191     { 5, "Dormant"},
192     { 6, "not present"},
193     { 7, "lower Layer down"},
194     { 0, NULL}
195 };
196 
197 #define CFM_CHASSIS_ID_CHASSIS_COMPONENT 1
198 #define CFM_CHASSIS_ID_INTERFACE_ALIAS 2
199 #define CFM_CHASSIS_ID_PORT_COMPONENT 3
200 #define CFM_CHASSIS_ID_MAC_ADDRESS 4
201 #define CFM_CHASSIS_ID_NETWORK_ADDRESS 5
202 #define CFM_CHASSIS_ID_INTERFACE_NAME 6
203 #define CFM_CHASSIS_ID_LOCAL 7
204 
205 static const struct tok cfm_tlv_senderid_chassisid_values[] = {
206     { 0, "Reserved"},
207     { CFM_CHASSIS_ID_CHASSIS_COMPONENT, "Chassis component"},
208     { CFM_CHASSIS_ID_INTERFACE_ALIAS, "Interface alias"},
209     { CFM_CHASSIS_ID_PORT_COMPONENT, "Port component"},
210     { CFM_CHASSIS_ID_MAC_ADDRESS, "MAC address"},
211     { CFM_CHASSIS_ID_NETWORK_ADDRESS, "Network address"},
212     { CFM_CHASSIS_ID_INTERFACE_NAME, "Interface name"},
213     { CFM_CHASSIS_ID_LOCAL, "Locally assigned"},
214     { 0, NULL}
215 };
216 
217 
218 static int
219 cfm_network_addr_print(netdissect_options *ndo,
220                        register const u_char *tptr, const u_int length)
221 {
222     u_int network_addr_type;
223     u_int hexdump =  FALSE;
224 
225     /*
226      * Altough AFIs are tpically 2 octects wide,
227      * 802.1ab specifies that this field width
228      * is only once octet
229      */
230     if (length < 1) {
231         ND_PRINT((ndo, "\n\t  Network Address Type (invalid, no data"));
232         return hexdump;
233     }
234     /* The calling function must make any due ND_TCHECK calls. */
235     network_addr_type = *tptr;
236     ND_PRINT((ndo, "\n\t  Network Address Type %s (%u)",
237            tok2str(af_values, "Unknown", network_addr_type),
238            network_addr_type));
239 
240     /*
241      * Resolve the passed in Address.
242      */
243     switch(network_addr_type) {
244     case AFNUM_INET:
245         if (length != 1 + 4) {
246             ND_PRINT((ndo, "(invalid IPv4 address length %u)", length - 1));
247             hexdump = TRUE;
248             break;
249         }
250         ND_PRINT((ndo, ", %s", ipaddr_string(ndo, tptr + 1)));
251         break;
252 
253     case AFNUM_INET6:
254         if (length != 1 + 16) {
255             ND_PRINT((ndo, "(invalid IPv6 address length %u)", length - 1));
256             hexdump = TRUE;
257             break;
258         }
259         ND_PRINT((ndo, ", %s", ip6addr_string(ndo, tptr + 1)));
260         break;
261 
262     default:
263         hexdump = TRUE;
264         break;
265     }
266 
267     return hexdump;
268 }
269 
270 void
271 cfm_print(netdissect_options *ndo,
272           register const u_char *pptr, register u_int length)
273 {
274     const struct cfm_common_header_t *cfm_common_header;
275     const struct cfm_tlv_header_t *cfm_tlv_header;
276     const uint8_t *tptr, *tlv_ptr;
277     const uint8_t *namesp;
278     u_int names_data_remaining;
279     uint8_t md_nameformat, md_namelength;
280     const uint8_t *md_name;
281     uint8_t ma_nameformat, ma_namelength;
282     const uint8_t *ma_name;
283     u_int hexdump, tlen, cfm_tlv_len, cfm_tlv_type, ccm_interval;
284 
285 
286     union {
287         const struct cfm_ccm_t *cfm_ccm;
288         const struct cfm_lbm_t *cfm_lbm;
289         const struct cfm_ltm_t *cfm_ltm;
290         const struct cfm_ltr_t *cfm_ltr;
291     } msg_ptr;
292 
293     tptr=pptr;
294     cfm_common_header = (const struct cfm_common_header_t *)pptr;
295     if (length < sizeof(*cfm_common_header))
296         goto tooshort;
297     ND_TCHECK(*cfm_common_header);
298 
299     /*
300      * Sanity checking of the header.
301      */
302     if (CFM_EXTRACT_VERSION(cfm_common_header->mdlevel_version) != CFM_VERSION) {
303 	ND_PRINT((ndo, "CFMv%u not supported, length %u",
304                CFM_EXTRACT_VERSION(cfm_common_header->mdlevel_version), length));
305 	return;
306     }
307 
308     ND_PRINT((ndo, "CFMv%u %s, MD Level %u, length %u",
309            CFM_EXTRACT_VERSION(cfm_common_header->mdlevel_version),
310            tok2str(cfm_opcode_values, "unknown (%u)", cfm_common_header->opcode),
311            CFM_EXTRACT_MD_LEVEL(cfm_common_header->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     ND_PRINT((ndo, "\n\tFirst TLV offset %u", cfm_common_header->first_tlv_offset));
322 
323     tptr += sizeof(const struct cfm_common_header_t);
324     tlen = length - sizeof(struct cfm_common_header_t);
325 
326     /*
327      * Sanity check the first TLV offset.
328      */
329     if (cfm_common_header->first_tlv_offset > tlen) {
330         ND_PRINT((ndo, " (too large, must be <= %u)", tlen));
331         return;
332     }
333 
334     switch (cfm_common_header->opcode) {
335     case CFM_OPCODE_CCM:
336         msg_ptr.cfm_ccm = (const struct cfm_ccm_t *)tptr;
337         if (cfm_common_header->first_tlv_offset < sizeof(*msg_ptr.cfm_ccm)) {
338             ND_PRINT((ndo, " (too small 1, must be >= %lu)",
339                      (unsigned long) sizeof(*msg_ptr.cfm_ccm)));
340             return;
341         }
342         if (tlen < sizeof(*msg_ptr.cfm_ccm))
343             goto tooshort;
344         ND_TCHECK(*msg_ptr.cfm_ccm);
345 
346         ccm_interval = CFM_EXTRACT_CCM_INTERVAL(cfm_common_header->flags);
347         ND_PRINT((ndo, ", Flags [CCM Interval %u%s]",
348                ccm_interval,
349                cfm_common_header->flags & CFM_CCM_RDI_FLAG ?
350                ", RDI" : ""));
351 
352         /*
353          * Resolve the CCM interval field.
354          */
355         if (ccm_interval) {
356             ND_PRINT((ndo, "\n\t  CCM Interval %.3fs"
357                    ", min CCM Lifetime %.3fs, max CCM Lifetime %.3fs",
358                    ccm_interval_base[ccm_interval],
359                    ccm_interval_base[ccm_interval] * CCM_INTERVAL_MIN_MULTIPLIER,
360                    ccm_interval_base[ccm_interval] * CCM_INTERVAL_MAX_MULTIPLIER));
361         }
362 
363         ND_PRINT((ndo, "\n\t  Sequence Number 0x%08x, MA-End-Point-ID 0x%04x",
364                EXTRACT_32BITS(msg_ptr.cfm_ccm->sequence),
365                EXTRACT_16BITS(msg_ptr.cfm_ccm->ma_epi)));
366 
367         namesp = msg_ptr.cfm_ccm->names;
368         names_data_remaining = sizeof(msg_ptr.cfm_ccm->names);
369 
370         /*
371          * Resolve the MD fields.
372          */
373         md_nameformat = *namesp;
374         namesp++;
375         names_data_remaining--;  /* We know this is != 0 */
376         if (md_nameformat != CFM_CCM_MD_FORMAT_NONE) {
377             md_namelength = *namesp;
378             namesp++;
379             names_data_remaining--; /* We know this is !=0 */
380             ND_PRINT((ndo, "\n\t  MD Name Format %s (%u), MD Name length %u",
381                    tok2str(cfm_md_nameformat_values, "Unknown",
382                            md_nameformat),
383                    md_nameformat,
384                    md_namelength));
385 
386             /*
387              * -3 for the MA short name format and length and one byte
388              * of MA short name.
389              */
390             if (md_namelength > names_data_remaining - 3) {
391                 ND_PRINT((ndo, " (too large, must be <= %u)", names_data_remaining - 2));
392                 return;
393             }
394 
395             md_name = namesp;
396             ND_PRINT((ndo, "\n\t  MD Name: "));
397             switch (md_nameformat) {
398             case CFM_CCM_MD_FORMAT_DNS:
399             case CFM_CCM_MD_FORMAT_CHAR:
400                 safeputs(ndo, md_name, md_namelength);
401                 break;
402 
403             case CFM_CCM_MD_FORMAT_MAC:
404                 if (md_namelength == 6) {
405                     ND_PRINT((ndo, "\n\t  MAC %s", etheraddr_string(ndo,
406                                md_name)));
407                 } else {
408                     ND_PRINT((ndo, "\n\t  MAC (length invalid)"));
409                 }
410                 break;
411 
412                 /* FIXME add printers for those MD formats - hexdump for now */
413             case CFM_CCM_MA_FORMAT_8021:
414             default:
415                 print_unknown_data(ndo, md_name, "\n\t    ",
416                                    md_namelength);
417             }
418             namesp += md_namelength;
419             names_data_remaining -= md_namelength;
420         } else {
421             ND_PRINT((ndo, "\n\t  MD Name Format %s (%u)",
422                    tok2str(cfm_md_nameformat_values, "Unknown",
423                            md_nameformat),
424                    md_nameformat));
425         }
426 
427 
428         /*
429          * Resolve the MA fields.
430          */
431         ma_nameformat = *namesp;
432         namesp++;
433         names_data_remaining--; /* We know this is != 0 */
434         ma_namelength = *namesp;
435         namesp++;
436         names_data_remaining--; /* We know this is != 0 */
437         ND_PRINT((ndo, "\n\t  MA Name-Format %s (%u), MA name length %u",
438                tok2str(cfm_ma_nameformat_values, "Unknown",
439                        ma_nameformat),
440                ma_nameformat,
441                ma_namelength));
442 
443         if (ma_namelength > names_data_remaining) {
444             ND_PRINT((ndo, " (too large, must be <= %u)", names_data_remaining));
445             return;
446         }
447 
448         ma_name = namesp;
449         ND_PRINT((ndo, "\n\t  MA Name: "));
450         switch (ma_nameformat) {
451         case CFM_CCM_MA_FORMAT_CHAR:
452             safeputs(ndo, ma_name, ma_namelength);
453             break;
454 
455             /* FIXME add printers for those MA formats - hexdump for now */
456         case CFM_CCM_MA_FORMAT_8021:
457         case CFM_CCM_MA_FORMAT_VID:
458         case CFM_CCM_MA_FORMAT_INT:
459         case CFM_CCM_MA_FORMAT_VPN:
460         default:
461             print_unknown_data(ndo, ma_name, "\n\t    ", ma_namelength);
462         }
463         break;
464 
465     case CFM_OPCODE_LTM:
466         msg_ptr.cfm_ltm = (const struct cfm_ltm_t *)tptr;
467         if (cfm_common_header->first_tlv_offset < sizeof(*msg_ptr.cfm_ltm)) {
468             ND_PRINT((ndo, " (too small 4, must be >= %lu)",
469                      (unsigned long) sizeof(*msg_ptr.cfm_ltm)));
470             return;
471         }
472         if (tlen < sizeof(*msg_ptr.cfm_ltm))
473             goto tooshort;
474         ND_TCHECK(*msg_ptr.cfm_ltm);
475 
476         ND_PRINT((ndo, ", Flags [%s]",
477                bittok2str(cfm_ltm_flag_values, "none", cfm_common_header->flags)));
478 
479         ND_PRINT((ndo, "\n\t  Transaction-ID 0x%08x, ttl %u",
480                EXTRACT_32BITS(msg_ptr.cfm_ltm->transaction_id),
481                msg_ptr.cfm_ltm->ttl));
482 
483         ND_PRINT((ndo, "\n\t  Original-MAC %s, Target-MAC %s",
484                etheraddr_string(ndo, msg_ptr.cfm_ltm->original_mac),
485                etheraddr_string(ndo, msg_ptr.cfm_ltm->target_mac)));
486         break;
487 
488     case CFM_OPCODE_LTR:
489         msg_ptr.cfm_ltr = (const struct cfm_ltr_t *)tptr;
490         if (cfm_common_header->first_tlv_offset < sizeof(*msg_ptr.cfm_ltr)) {
491             ND_PRINT((ndo, " (too small 5, must be >= %lu)",
492                      (unsigned long) sizeof(*msg_ptr.cfm_ltr)));
493             return;
494         }
495         if (tlen < sizeof(*msg_ptr.cfm_ltr))
496             goto tooshort;
497         ND_TCHECK(*msg_ptr.cfm_ltr);
498 
499         ND_PRINT((ndo, ", Flags [%s]",
500                bittok2str(cfm_ltr_flag_values, "none", cfm_common_header->flags)));
501 
502         ND_PRINT((ndo, "\n\t  Transaction-ID 0x%08x, ttl %u",
503                EXTRACT_32BITS(msg_ptr.cfm_ltr->transaction_id),
504                msg_ptr.cfm_ltr->ttl));
505 
506         ND_PRINT((ndo, "\n\t  Replay-Action %s (%u)",
507                tok2str(cfm_ltr_replay_action_values,
508                        "Unknown",
509                        msg_ptr.cfm_ltr->replay_action),
510                msg_ptr.cfm_ltr->replay_action));
511         break;
512 
513         /*
514          * No message decoder yet.
515          * Hexdump everything up until the start of the TLVs
516          */
517     case CFM_OPCODE_LBR:
518     case CFM_OPCODE_LBM:
519     default:
520         print_unknown_data(ndo, tptr, "\n\t  ",
521                            tlen -  cfm_common_header->first_tlv_offset);
522         break;
523     }
524 
525     tptr += cfm_common_header->first_tlv_offset;
526     tlen -= cfm_common_header->first_tlv_offset;
527 
528     while (tlen > 0) {
529         cfm_tlv_header = (const struct cfm_tlv_header_t *)tptr;
530 
531         /* Enough to read the tlv type ? */
532         ND_TCHECK2(*tptr, 1);
533         cfm_tlv_type=cfm_tlv_header->type;
534 
535         ND_PRINT((ndo, "\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_TCHECK2(*tptr, sizeof(struct cfm_tlv_header_t));
548         cfm_tlv_len=EXTRACT_16BITS(&cfm_tlv_header->length);
549 
550         ND_PRINT((ndo, ", 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_TCHECK2(*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((ndo, " (too short, must be >= 1)"));
566                 return;
567             }
568             ND_PRINT((ndo, ", Status: %s (%u)",
569                    tok2str(cfm_tlv_port_status_values, "Unknown", *tptr),
570                    *tptr));
571             break;
572 
573         case CFM_TLV_INTERFACE_STATUS:
574             if (cfm_tlv_len < 1) {
575                 ND_PRINT((ndo, " (too short, must be >= 1)"));
576                 return;
577             }
578             ND_PRINT((ndo, ", Status: %s (%u)",
579                    tok2str(cfm_tlv_interface_status_values, "Unknown", *tptr),
580                    *tptr));
581             break;
582 
583         case CFM_TLV_PRIVATE:
584             if (cfm_tlv_len < 4) {
585                 ND_PRINT((ndo, " (too short, must be >= 4)"));
586                 return;
587             }
588             ND_PRINT((ndo, ", Vendor: %s (%u), Sub-Type %u",
589                    tok2str(oui_values,"Unknown", EXTRACT_24BITS(tptr)),
590                    EXTRACT_24BITS(tptr),
591                    *(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((ndo, " (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 = *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((ndo, "\n\t  (TLV too short)"));
622                     goto next_tlv;
623                 }
624                 chassis_id_type = *tptr;
625                 cfm_tlv_len--;
626                 ND_PRINT((ndo, "\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((ndo, "\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 != ETHER_ADDR_LEN) {
642                         ND_PRINT((ndo, " (invalid MAC address length)"));
643                         hexdump = TRUE;
644                         break;
645                     }
646                     ND_PRINT((ndo, "\n\t  MAC %s", etheraddr_string(ndo, 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                     safeputs(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 = *tptr;
684             tptr++;
685             tlen--;
686             cfm_tlv_len--;
687             ND_PRINT((ndo, "\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((ndo, "\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((ndo, " (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 = *tptr;
714                 tptr++;
715                 tlen--;
716                 cfm_tlv_len--;
717                 ND_PRINT((ndo, "\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((ndo, "\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((ndo, "\n\t\t packet is too short"));
760     return;
761 
762 trunc:
763     ND_PRINT((ndo, "\n\t\t packet exceeded snapshot"));
764 }
765