xref: /freebsd/contrib/tcpdump/print-babel.c (revision dd41de95a84d979615a2ef11df6850622bf6184e)
1 /*
2  * Copyright (c) 2007-2011 Grégoire Henry, Juliusz Chroboczek
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  * 3. Neither the name of the project nor the names of its contributors
13  *    may be used to endorse or promote products derived from this software
14  *    without specific prior written permission.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 /* \summary: Babel Routing Protocol printer */
30 
31 #ifdef HAVE_CONFIG_H
32 #include "config.h"
33 #endif
34 
35 #include <netdissect-stdinc.h>
36 
37 #include <stdio.h>
38 #include <string.h>
39 
40 #include "netdissect.h"
41 #include "addrtoname.h"
42 #include "extract.h"
43 
44 static const char tstr[] = "[|babel]";
45 
46 static void babel_print_v2(netdissect_options *, const u_char *cp, u_int length);
47 
48 void
49 babel_print(netdissect_options *ndo,
50             const u_char *cp, u_int length)
51 {
52     ND_PRINT((ndo, "babel"));
53 
54     ND_TCHECK2(*cp, 4);
55 
56     if(cp[0] != 42) {
57         ND_PRINT((ndo, " invalid header"));
58         return;
59     } else {
60         ND_PRINT((ndo, " %d", cp[1]));
61     }
62 
63     switch(cp[1]) {
64     case 2:
65         babel_print_v2(ndo, cp, length);
66         break;
67     default:
68         ND_PRINT((ndo, " unknown version"));
69         break;
70     }
71 
72     return;
73 
74  trunc:
75     ND_PRINT((ndo, " %s", tstr));
76     return;
77 }
78 
79 /* TLVs */
80 #define MESSAGE_PAD1 0
81 #define MESSAGE_PADN 1
82 #define MESSAGE_ACK_REQ 2
83 #define MESSAGE_ACK 3
84 #define MESSAGE_HELLO 4
85 #define MESSAGE_IHU 5
86 #define MESSAGE_ROUTER_ID 6
87 #define MESSAGE_NH 7
88 #define MESSAGE_UPDATE 8
89 #define MESSAGE_REQUEST 9
90 #define MESSAGE_MH_REQUEST 10
91 #define MESSAGE_TSPC 11
92 #define MESSAGE_HMAC 12
93 #define MESSAGE_UPDATE_SRC_SPECIFIC 13
94 #define MESSAGE_REQUEST_SRC_SPECIFIC 14
95 #define MESSAGE_MH_REQUEST_SRC_SPECIFIC 15
96 
97 /* sub-TLVs */
98 #define MESSAGE_SUB_PAD1 0
99 #define MESSAGE_SUB_PADN 1
100 #define MESSAGE_SUB_DIVERSITY 2
101 #define MESSAGE_SUB_TIMESTAMP 3
102 
103 /* Diversity sub-TLV channel codes */
104 static const struct tok diversity_str[] = {
105     { 0,   "reserved" },
106     { 255, "all"      },
107     { 0, NULL }
108 };
109 
110 static const char *
111 format_id(const u_char *id)
112 {
113     static char buf[25];
114     snprintf(buf, 25, "%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x",
115              id[0], id[1], id[2], id[3], id[4], id[5], id[6], id[7]);
116     buf[24] = '\0';
117     return buf;
118 }
119 
120 static const unsigned char v4prefix[16] =
121     {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xFF, 0xFF, 0, 0, 0, 0 };
122 
123 static const char *
124 format_prefix(netdissect_options *ndo, const u_char *prefix, unsigned char plen)
125 {
126     static char buf[50];
127     if(plen >= 96 && memcmp(prefix, v4prefix, 12) == 0)
128         snprintf(buf, 50, "%s/%u", ipaddr_string(ndo, prefix + 12), plen - 96);
129     else
130         snprintf(buf, 50, "%s/%u", ip6addr_string(ndo, prefix), plen);
131     buf[49] = '\0';
132     return buf;
133 }
134 
135 static const char *
136 format_address(netdissect_options *ndo, const u_char *prefix)
137 {
138     if(memcmp(prefix, v4prefix, 12) == 0)
139         return ipaddr_string(ndo, prefix + 12);
140     else
141         return ip6addr_string(ndo, prefix);
142 }
143 
144 static const char *
145 format_interval(const uint16_t i)
146 {
147     static char buf[sizeof("000.00s")];
148 
149     if (i == 0)
150         return "0.0s (bogus)";
151     snprintf(buf, sizeof(buf), "%u.%02us", i / 100, i % 100);
152     return buf;
153 }
154 
155 static const char *
156 format_interval_update(const uint16_t i)
157 {
158     return i == 0xFFFF ? "infinity" : format_interval(i);
159 }
160 
161 static const char *
162 format_timestamp(const uint32_t i)
163 {
164     static char buf[sizeof("0000.000000s")];
165     snprintf(buf, sizeof(buf), "%u.%06us", i / 1000000, i % 1000000);
166     return buf;
167 }
168 
169 /* Return number of octets consumed from the input buffer (not the prefix length
170  * in bytes), or -1 for encoding error. */
171 static int
172 network_prefix(int ae, int plen, unsigned int omitted,
173                const unsigned char *p, const unsigned char *dp,
174                unsigned int len, unsigned char *p_r)
175 {
176     unsigned pb;
177     unsigned char prefix[16];
178     int consumed = 0;
179 
180     if(plen >= 0)
181         pb = (plen + 7) / 8;
182     else if(ae == 1)
183         pb = 4;
184     else
185         pb = 16;
186 
187     if(pb > 16)
188         return -1;
189 
190     memset(prefix, 0, 16);
191 
192     switch(ae) {
193     case 0: break;
194     case 1:
195         if(omitted > 4 || pb > 4 || (pb > omitted && len < pb - omitted))
196             return -1;
197         memcpy(prefix, v4prefix, 12);
198         if(omitted) {
199             if (dp == NULL) return -1;
200             memcpy(prefix, dp, 12 + omitted);
201         }
202         if(pb > omitted) {
203             memcpy(prefix + 12 + omitted, p, pb - omitted);
204             consumed = pb - omitted;
205         }
206         break;
207     case 2:
208         if(omitted > 16 || (pb > omitted && len < pb - omitted))
209             return -1;
210         if(omitted) {
211             if (dp == NULL) return -1;
212             memcpy(prefix, dp, omitted);
213         }
214         if(pb > omitted) {
215             memcpy(prefix + omitted, p, pb - omitted);
216             consumed = pb - omitted;
217         }
218         break;
219     case 3:
220         if(pb > 8 && len < pb - 8) return -1;
221         prefix[0] = 0xfe;
222         prefix[1] = 0x80;
223         if(pb > 8) {
224             memcpy(prefix + 8, p, pb - 8);
225             consumed = pb - 8;
226         }
227         break;
228     default:
229         return -1;
230     }
231 
232     memcpy(p_r, prefix, 16);
233     return consumed;
234 }
235 
236 static int
237 network_address(int ae, const unsigned char *a, unsigned int len,
238                 unsigned char *a_r)
239 {
240     return network_prefix(ae, -1, 0, a, NULL, len, a_r);
241 }
242 
243 /*
244  * Sub-TLVs consume the "extra data" of Babel TLVs (see Section 4.3 of RFC6126),
245  * their encoding is similar to the encoding of TLVs, but the type namespace is
246  * different:
247  *
248  * o Type 0 stands for Pad1 sub-TLV with the same encoding as the Pad1 TLV.
249  * o Type 1 stands for PadN sub-TLV with the same encoding as the PadN TLV.
250  * o Type 2 stands for Diversity sub-TLV, which propagates diversity routing
251  *   data. Its body is a variable-length sequence of 8-bit unsigned integers,
252  *   each representing per-hop number of interferring radio channel for the
253  *   prefix. Channel 0 is invalid and must not be used in the sub-TLV, channel
254  *   255 interferes with any other channel.
255  * o Type 3 stands for Timestamp sub-TLV, used to compute RTT between
256  *   neighbours. In the case of a Hello TLV, the body stores a 32-bits
257  *   timestamp, while in the case of a IHU TLV, two 32-bits timestamps are
258  *   stored.
259  *
260  * Sub-TLV types 0 and 1 are valid for any TLV type, whether sub-TLV type 2 is
261  * only valid for TLV type 8 (Update). Note that within an Update TLV a missing
262  * Diversity sub-TLV is not the same as a Diversity sub-TLV with an empty body.
263  * The former would mean a lack of any claims about the interference, and the
264  * latter would state that interference is definitely absent.
265  * A type 3 sub-TLV is valid both for Hello and IHU TLVs, though the exact
266  * semantic of the sub-TLV is different in each case.
267  */
268 static void
269 subtlvs_print(netdissect_options *ndo,
270               const u_char *cp, const u_char *ep, const uint8_t tlv_type)
271 {
272     uint8_t subtype, sublen;
273     const char *sep;
274     uint32_t t1, t2;
275 
276     while (cp < ep) {
277         subtype = *cp++;
278         if(subtype == MESSAGE_SUB_PAD1) {
279             ND_PRINT((ndo, " sub-pad1"));
280             continue;
281         }
282         if(cp == ep)
283             goto invalid;
284         sublen = *cp++;
285         if(cp + sublen > ep)
286             goto invalid;
287 
288         switch(subtype) {
289         case MESSAGE_SUB_PADN:
290             ND_PRINT((ndo, " sub-padn"));
291             cp += sublen;
292             break;
293         case MESSAGE_SUB_DIVERSITY:
294             ND_PRINT((ndo, " sub-diversity"));
295             if (sublen == 0) {
296                 ND_PRINT((ndo, " empty"));
297                 break;
298             }
299             sep = " ";
300             while(sublen--) {
301                 ND_PRINT((ndo, "%s%s", sep, tok2str(diversity_str, "%u", *cp++)));
302                 sep = "-";
303             }
304             if(tlv_type != MESSAGE_UPDATE &&
305                tlv_type != MESSAGE_UPDATE_SRC_SPECIFIC)
306                 ND_PRINT((ndo, " (bogus)"));
307             break;
308         case MESSAGE_SUB_TIMESTAMP:
309             ND_PRINT((ndo, " sub-timestamp"));
310             if(tlv_type == MESSAGE_HELLO) {
311                 if(sublen < 4)
312                     goto invalid;
313                 t1 = EXTRACT_32BITS(cp);
314                 ND_PRINT((ndo, " %s", format_timestamp(t1)));
315             } else if(tlv_type == MESSAGE_IHU) {
316                 if(sublen < 8)
317                     goto invalid;
318                 t1 = EXTRACT_32BITS(cp);
319                 ND_PRINT((ndo, " %s", format_timestamp(t1)));
320                 t2 = EXTRACT_32BITS(cp + 4);
321                 ND_PRINT((ndo, "|%s", format_timestamp(t2)));
322             } else
323                 ND_PRINT((ndo, " (bogus)"));
324             cp += sublen;
325             break;
326         default:
327             ND_PRINT((ndo, " sub-unknown-0x%02x", subtype));
328             cp += sublen;
329         } /* switch */
330     } /* while */
331     return;
332 
333  invalid:
334     ND_PRINT((ndo, "%s", istr));
335 }
336 
337 #define ICHECK(i, l) \
338 	if ((i) + (l) > bodylen || (i) + (l) > length) goto invalid;
339 
340 static void
341 babel_print_v2(netdissect_options *ndo,
342                const u_char *cp, u_int length)
343 {
344     u_int i;
345     u_short bodylen;
346     u_char v4_prefix[16] =
347         {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xFF, 0xFF, 0, 0, 0, 0 };
348     u_char v6_prefix[16] = {0};
349 
350     ND_TCHECK2(*cp, 4);
351     if (length < 4)
352         goto invalid;
353     bodylen = EXTRACT_16BITS(cp + 2);
354     ND_PRINT((ndo, " (%u)", bodylen));
355     if (4U + bodylen > length)
356         goto invalid;
357 
358     /* Process the TLVs in the body */
359     i = 0;
360     while(i < bodylen) {
361         const u_char *message;
362         u_int type, len;
363 
364         message = cp + 4 + i;
365 
366         ND_TCHECK2(*message, 1);
367         if((type = message[0]) == MESSAGE_PAD1) {
368             ND_PRINT((ndo, ndo->ndo_vflag ? "\n\tPad 1" : " pad1"));
369             i += 1;
370             continue;
371         }
372 
373         ND_TCHECK2(*message, 2);
374         ICHECK(i, 2);
375         len = message[1];
376 
377         ND_TCHECK2(*message, 2 + len);
378         ICHECK(i, 2 + len);
379 
380         switch(type) {
381         case MESSAGE_PADN: {
382             if (!ndo->ndo_vflag)
383                 ND_PRINT((ndo, " padN"));
384             else
385                 ND_PRINT((ndo, "\n\tPad %d", len + 2));
386         }
387             break;
388 
389         case MESSAGE_ACK_REQ: {
390             u_short nonce, interval;
391             if (!ndo->ndo_vflag)
392                 ND_PRINT((ndo, " ack-req"));
393             else {
394                 ND_PRINT((ndo, "\n\tAcknowledgment Request "));
395                 if(len < 6) goto invalid;
396                 nonce = EXTRACT_16BITS(message + 4);
397                 interval = EXTRACT_16BITS(message + 6);
398                 ND_PRINT((ndo, "%04x %s", nonce, format_interval(interval)));
399             }
400         }
401             break;
402 
403         case MESSAGE_ACK: {
404             u_short nonce;
405             if (!ndo->ndo_vflag)
406                 ND_PRINT((ndo, " ack"));
407             else {
408                 ND_PRINT((ndo, "\n\tAcknowledgment "));
409                 if(len < 2) goto invalid;
410                 nonce = EXTRACT_16BITS(message + 2);
411                 ND_PRINT((ndo, "%04x", nonce));
412             }
413         }
414             break;
415 
416         case MESSAGE_HELLO:  {
417             u_short seqno, interval;
418             if (!ndo->ndo_vflag)
419                 ND_PRINT((ndo, " hello"));
420             else {
421                 ND_PRINT((ndo, "\n\tHello "));
422                 if(len < 6) goto invalid;
423                 seqno = EXTRACT_16BITS(message + 4);
424                 interval = EXTRACT_16BITS(message + 6);
425                 ND_PRINT((ndo, "seqno %u interval %s", seqno, format_interval(interval)));
426                 /* Extra data. */
427                 if(len > 6)
428                     subtlvs_print(ndo, message + 8, message + 2 + len, type);
429             }
430         }
431             break;
432 
433         case MESSAGE_IHU: {
434             unsigned short txcost, interval;
435             if (!ndo->ndo_vflag)
436                 ND_PRINT((ndo, " ihu"));
437             else {
438                 u_char address[16];
439                 int rc;
440                 ND_PRINT((ndo, "\n\tIHU "));
441                 if(len < 6) goto invalid;
442                 txcost = EXTRACT_16BITS(message + 4);
443                 interval = EXTRACT_16BITS(message + 6);
444                 rc = network_address(message[2], message + 8, len - 6, address);
445                 if(rc < 0) { ND_PRINT((ndo, "%s", tstr)); break; }
446                 ND_PRINT((ndo, "%s txcost %u interval %s",
447                        format_address(ndo, address), txcost, format_interval(interval)));
448                 /* Extra data. */
449                 if((u_int)rc < len - 6)
450                     subtlvs_print(ndo, message + 8 + rc, message + 2 + len,
451                                   type);
452             }
453         }
454             break;
455 
456         case MESSAGE_ROUTER_ID: {
457             if (!ndo->ndo_vflag)
458                 ND_PRINT((ndo, " router-id"));
459             else {
460                 ND_PRINT((ndo, "\n\tRouter Id"));
461                 if(len < 10) goto invalid;
462                 ND_PRINT((ndo, " %s", format_id(message + 4)));
463             }
464         }
465             break;
466 
467         case MESSAGE_NH: {
468             if (!ndo->ndo_vflag)
469                 ND_PRINT((ndo, " nh"));
470             else {
471                 int rc;
472                 u_char nh[16];
473                 ND_PRINT((ndo, "\n\tNext Hop"));
474                 if(len < 2) goto invalid;
475                 rc = network_address(message[2], message + 4, len - 2, nh);
476                 if(rc < 0) goto invalid;
477                 ND_PRINT((ndo, " %s", format_address(ndo, nh)));
478             }
479         }
480             break;
481 
482         case MESSAGE_UPDATE: {
483             if (!ndo->ndo_vflag) {
484                 ND_PRINT((ndo, " update"));
485                 if(len < 10)
486                     ND_PRINT((ndo, "/truncated"));
487                 else
488                     ND_PRINT((ndo, "%s%s%s",
489                            (message[3] & 0x80) ? "/prefix": "",
490                            (message[3] & 0x40) ? "/id" : "",
491                            (message[3] & 0x3f) ? "/unknown" : ""));
492             } else {
493                 u_short interval, seqno, metric;
494                 u_char plen;
495                 int rc;
496                 u_char prefix[16];
497                 ND_PRINT((ndo, "\n\tUpdate"));
498                 if(len < 10) goto invalid;
499                 plen = message[4] + (message[2] == 1 ? 96 : 0);
500                 rc = network_prefix(message[2], message[4], message[5],
501                                     message + 12,
502                                     message[2] == 1 ? v4_prefix : v6_prefix,
503                                     len - 10, prefix);
504                 if(rc < 0) goto invalid;
505                 interval = EXTRACT_16BITS(message + 6);
506                 seqno = EXTRACT_16BITS(message + 8);
507                 metric = EXTRACT_16BITS(message + 10);
508                 ND_PRINT((ndo, "%s%s%s %s metric %u seqno %u interval %s",
509                        (message[3] & 0x80) ? "/prefix": "",
510                        (message[3] & 0x40) ? "/id" : "",
511                        (message[3] & 0x3f) ? "/unknown" : "",
512                        format_prefix(ndo, prefix, plen),
513                        metric, seqno, format_interval_update(interval)));
514                 if(message[3] & 0x80) {
515                     if(message[2] == 1)
516                         memcpy(v4_prefix, prefix, 16);
517                     else
518                         memcpy(v6_prefix, prefix, 16);
519                 }
520                 /* extra data? */
521                 if((u_int)rc < len - 10)
522                     subtlvs_print(ndo, message + 12 + rc, message + 2 + len, type);
523             }
524         }
525             break;
526 
527         case MESSAGE_REQUEST: {
528             if (!ndo->ndo_vflag)
529                 ND_PRINT((ndo, " request"));
530             else {
531                 int rc;
532                 u_char prefix[16], plen;
533                 ND_PRINT((ndo, "\n\tRequest "));
534                 if(len < 2) goto invalid;
535                 plen = message[3] + (message[2] == 1 ? 96 : 0);
536                 rc = network_prefix(message[2], message[3], 0,
537                                     message + 4, NULL, len - 2, prefix);
538                 if(rc < 0) goto invalid;
539                 ND_PRINT((ndo, "for %s",
540                        message[2] == 0 ? "any" : format_prefix(ndo, prefix, plen)));
541             }
542         }
543             break;
544 
545         case MESSAGE_MH_REQUEST : {
546             if (!ndo->ndo_vflag)
547                 ND_PRINT((ndo, " mh-request"));
548             else {
549                 int rc;
550                 u_short seqno;
551                 u_char prefix[16], plen;
552                 ND_PRINT((ndo, "\n\tMH-Request "));
553                 if(len < 14) goto invalid;
554                 seqno = EXTRACT_16BITS(message + 4);
555                 rc = network_prefix(message[2], message[3], 0,
556                                     message + 16, NULL, len - 14, prefix);
557                 if(rc < 0) goto invalid;
558                 plen = message[3] + (message[2] == 1 ? 96 : 0);
559                 ND_PRINT((ndo, "(%u hops) for %s seqno %u id %s",
560                        message[6], format_prefix(ndo, prefix, plen),
561                        seqno, format_id(message + 8)));
562             }
563         }
564             break;
565         case MESSAGE_TSPC :
566             if (!ndo->ndo_vflag)
567                 ND_PRINT((ndo, " tspc"));
568             else {
569                 ND_PRINT((ndo, "\n\tTS/PC "));
570                 if(len < 6) goto invalid;
571                 ND_PRINT((ndo, "timestamp %u packetcounter %u", EXTRACT_32BITS (message + 4),
572                        EXTRACT_16BITS(message + 2)));
573             }
574             break;
575         case MESSAGE_HMAC : {
576             if (!ndo->ndo_vflag)
577                 ND_PRINT((ndo, " hmac"));
578             else {
579                 unsigned j;
580                 ND_PRINT((ndo, "\n\tHMAC "));
581                 if(len < 18) goto invalid;
582                 ND_PRINT((ndo, "key-id %u digest-%u ", EXTRACT_16BITS(message + 2), len - 2));
583                 for (j = 0; j < len - 2; j++)
584                     ND_PRINT((ndo, "%02X", message[4 + j]));
585             }
586         }
587             break;
588 
589         case MESSAGE_UPDATE_SRC_SPECIFIC : {
590             if(!ndo->ndo_vflag) {
591                 ND_PRINT((ndo, " ss-update"));
592             } else {
593                 u_char prefix[16], src_prefix[16];
594                 u_short interval, seqno, metric;
595                 u_char ae, plen, src_plen, omitted;
596                 int rc;
597                 int parsed_len = 10;
598                 ND_PRINT((ndo, "\n\tSS-Update"));
599                 if(len < 10) goto invalid;
600                 ae = message[2];
601                 src_plen = message[3];
602                 plen = message[4];
603                 omitted = message[5];
604                 interval = EXTRACT_16BITS(message + 6);
605                 seqno = EXTRACT_16BITS(message + 8);
606                 metric = EXTRACT_16BITS(message + 10);
607                 rc = network_prefix(ae, plen, omitted, message + 2 + parsed_len,
608                                     ae == 1 ? v4_prefix : v6_prefix,
609                                     len - parsed_len, prefix);
610                 if(rc < 0) goto invalid;
611                 if(ae == 1)
612                     plen += 96;
613                 parsed_len += rc;
614                 rc = network_prefix(ae, src_plen, 0, message + 2 + parsed_len,
615                                     NULL, len - parsed_len, src_prefix);
616                 if(rc < 0) goto invalid;
617                 if(ae == 1)
618                     src_plen += 96;
619                 parsed_len += rc;
620 
621                 ND_PRINT((ndo, " %s from", format_prefix(ndo, prefix, plen)));
622                 ND_PRINT((ndo, " %s metric %u seqno %u interval %s",
623                           format_prefix(ndo, src_prefix, src_plen),
624                           metric, seqno, format_interval_update(interval)));
625                 /* extra data? */
626                 if((u_int)parsed_len < len)
627                     subtlvs_print(ndo, message + 2 + parsed_len,
628                                   message + 2 + len, type);
629             }
630         }
631             break;
632 
633         case MESSAGE_REQUEST_SRC_SPECIFIC : {
634             if(!ndo->ndo_vflag)
635                 ND_PRINT((ndo, " ss-request"));
636             else {
637                 int rc, parsed_len = 3;
638                 u_char ae, plen, src_plen, prefix[16], src_prefix[16];
639                 ND_PRINT((ndo, "\n\tSS-Request "));
640                 if(len < 3) goto invalid;
641                 ae = message[2];
642                 plen = message[3];
643                 src_plen = message[4];
644                 rc = network_prefix(ae, plen, 0, message + 2 + parsed_len,
645                                     NULL, len - parsed_len, prefix);
646                 if(rc < 0) goto invalid;
647                 if(ae == 1)
648                     plen += 96;
649                 parsed_len += rc;
650                 rc = network_prefix(ae, src_plen, 0, message + 2 + parsed_len,
651                                     NULL, len - parsed_len, src_prefix);
652                 if(rc < 0) goto invalid;
653                 if(ae == 1)
654                     src_plen += 96;
655                 parsed_len += rc;
656                 if(ae == 0) {
657                     ND_PRINT((ndo, "for any"));
658                 } else {
659                     ND_PRINT((ndo, "for (%s, ", format_prefix(ndo, prefix, plen)));
660                     ND_PRINT((ndo, "%s)", format_prefix(ndo, src_prefix, src_plen)));
661                 }
662             }
663         }
664             break;
665 
666         case MESSAGE_MH_REQUEST_SRC_SPECIFIC : {
667             if(!ndo->ndo_vflag)
668                 ND_PRINT((ndo, " ss-mh-request"));
669             else {
670                 int rc, parsed_len = 14;
671                 u_short seqno;
672                 u_char ae, plen, src_plen, prefix[16], src_prefix[16], hopc;
673                 const u_char *router_id = NULL;
674                 ND_PRINT((ndo, "\n\tSS-MH-Request "));
675                 if(len < 14) goto invalid;
676                 ae = message[2];
677                 plen = message[3];
678                 seqno = EXTRACT_16BITS(message + 4);
679                 hopc = message[6];
680                 src_plen = message[7];
681                 router_id = message + 8;
682                 rc = network_prefix(ae, plen, 0, message + 2 + parsed_len,
683                                     NULL, len - parsed_len, prefix);
684                 if(rc < 0) goto invalid;
685                 if(ae == 1)
686                     plen += 96;
687                 parsed_len += rc;
688                 rc = network_prefix(ae, src_plen, 0, message + 2 + parsed_len,
689                                     NULL, len - parsed_len, src_prefix);
690                 if(rc < 0) goto invalid;
691                 if(ae == 1)
692                     src_plen += 96;
693                 ND_PRINT((ndo, "(%u hops) for (%s, ",
694                           hopc, format_prefix(ndo, prefix, plen)));
695                 ND_PRINT((ndo, "%s) seqno %u id %s",
696                           format_prefix(ndo, src_prefix, src_plen),
697                           seqno, format_id(router_id)));
698             }
699         }
700             break;
701 
702         default:
703             if (!ndo->ndo_vflag)
704                 ND_PRINT((ndo, " unknown"));
705             else
706                 ND_PRINT((ndo, "\n\tUnknown message type %d", type));
707         }
708         i += len + 2;
709     }
710     return;
711 
712  trunc:
713     ND_PRINT((ndo, " %s", tstr));
714     return;
715 
716  invalid:
717     ND_PRINT((ndo, "%s", istr));
718     return;
719 }
720