xref: /freebsd/contrib/tcpdump/print-babel.c (revision 3416500aef140042c64bc149cb1ec6620483bc44)
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 
356     /* Process the TLVs in the body */
357     i = 0;
358     while(i < bodylen) {
359         const u_char *message;
360         u_int type, len;
361 
362         message = cp + 4 + i;
363 
364         ND_TCHECK2(*message, 1);
365         if((type = message[0]) == MESSAGE_PAD1) {
366             ND_PRINT((ndo, ndo->ndo_vflag ? "\n\tPad 1" : " pad1"));
367             i += 1;
368             continue;
369         }
370 
371         ND_TCHECK2(*message, 2);
372         ICHECK(i, 2);
373         len = message[1];
374 
375         ND_TCHECK2(*message, 2 + len);
376         ICHECK(i, 2 + len);
377 
378         switch(type) {
379         case MESSAGE_PADN: {
380             if (!ndo->ndo_vflag)
381                 ND_PRINT((ndo, " padN"));
382             else
383                 ND_PRINT((ndo, "\n\tPad %d", len + 2));
384         }
385             break;
386 
387         case MESSAGE_ACK_REQ: {
388             u_short nonce, interval;
389             if (!ndo->ndo_vflag)
390                 ND_PRINT((ndo, " ack-req"));
391             else {
392                 ND_PRINT((ndo, "\n\tAcknowledgment Request "));
393                 if(len < 6) goto invalid;
394                 nonce = EXTRACT_16BITS(message + 4);
395                 interval = EXTRACT_16BITS(message + 6);
396                 ND_PRINT((ndo, "%04x %s", nonce, format_interval(interval)));
397             }
398         }
399             break;
400 
401         case MESSAGE_ACK: {
402             u_short nonce;
403             if (!ndo->ndo_vflag)
404                 ND_PRINT((ndo, " ack"));
405             else {
406                 ND_PRINT((ndo, "\n\tAcknowledgment "));
407                 if(len < 2) goto invalid;
408                 nonce = EXTRACT_16BITS(message + 2);
409                 ND_PRINT((ndo, "%04x", nonce));
410             }
411         }
412             break;
413 
414         case MESSAGE_HELLO:  {
415             u_short seqno, interval;
416             if (!ndo->ndo_vflag)
417                 ND_PRINT((ndo, " hello"));
418             else {
419                 ND_PRINT((ndo, "\n\tHello "));
420                 if(len < 6) goto invalid;
421                 seqno = EXTRACT_16BITS(message + 4);
422                 interval = EXTRACT_16BITS(message + 6);
423                 ND_PRINT((ndo, "seqno %u interval %s", seqno, format_interval(interval)));
424                 /* Extra data. */
425                 if(len > 6)
426                     subtlvs_print(ndo, message + 8, message + 2 + len, type);
427             }
428         }
429             break;
430 
431         case MESSAGE_IHU: {
432             unsigned short txcost, interval;
433             if (!ndo->ndo_vflag)
434                 ND_PRINT((ndo, " ihu"));
435             else {
436                 u_char address[16];
437                 int rc;
438                 ND_PRINT((ndo, "\n\tIHU "));
439                 if(len < 6) goto invalid;
440                 txcost = EXTRACT_16BITS(message + 4);
441                 interval = EXTRACT_16BITS(message + 6);
442                 rc = network_address(message[2], message + 8, len - 6, address);
443                 if(rc < 0) { ND_PRINT((ndo, "%s", tstr)); break; }
444                 ND_PRINT((ndo, "%s txcost %u interval %s",
445                        format_address(ndo, address), txcost, format_interval(interval)));
446                 /* Extra data. */
447                 if((u_int)rc < len - 6)
448                     subtlvs_print(ndo, message + 8 + rc, message + 2 + len,
449                                   type);
450             }
451         }
452             break;
453 
454         case MESSAGE_ROUTER_ID: {
455             if (!ndo->ndo_vflag)
456                 ND_PRINT((ndo, " router-id"));
457             else {
458                 ND_PRINT((ndo, "\n\tRouter Id"));
459                 if(len < 10) goto invalid;
460                 ND_PRINT((ndo, " %s", format_id(message + 4)));
461             }
462         }
463             break;
464 
465         case MESSAGE_NH: {
466             if (!ndo->ndo_vflag)
467                 ND_PRINT((ndo, " nh"));
468             else {
469                 int rc;
470                 u_char nh[16];
471                 ND_PRINT((ndo, "\n\tNext Hop"));
472                 if(len < 2) goto invalid;
473                 rc = network_address(message[2], message + 4, len - 2, nh);
474                 if(rc < 0) goto invalid;
475                 ND_PRINT((ndo, " %s", format_address(ndo, nh)));
476             }
477         }
478             break;
479 
480         case MESSAGE_UPDATE: {
481             if (!ndo->ndo_vflag) {
482                 ND_PRINT((ndo, " update"));
483                 if(len < 1)
484                     ND_PRINT((ndo, "/truncated"));
485                 else
486                     ND_PRINT((ndo, "%s%s%s",
487                            (message[3] & 0x80) ? "/prefix": "",
488                            (message[3] & 0x40) ? "/id" : "",
489                            (message[3] & 0x3f) ? "/unknown" : ""));
490             } else {
491                 u_short interval, seqno, metric;
492                 u_char plen;
493                 int rc;
494                 u_char prefix[16];
495                 ND_PRINT((ndo, "\n\tUpdate"));
496                 if(len < 10) goto invalid;
497                 plen = message[4] + (message[2] == 1 ? 96 : 0);
498                 rc = network_prefix(message[2], message[4], message[5],
499                                     message + 12,
500                                     message[2] == 1 ? v4_prefix : v6_prefix,
501                                     len - 10, prefix);
502                 if(rc < 0) goto invalid;
503                 interval = EXTRACT_16BITS(message + 6);
504                 seqno = EXTRACT_16BITS(message + 8);
505                 metric = EXTRACT_16BITS(message + 10);
506                 ND_PRINT((ndo, "%s%s%s %s metric %u seqno %u interval %s",
507                        (message[3] & 0x80) ? "/prefix": "",
508                        (message[3] & 0x40) ? "/id" : "",
509                        (message[3] & 0x3f) ? "/unknown" : "",
510                        format_prefix(ndo, prefix, plen),
511                        metric, seqno, format_interval_update(interval)));
512                 if(message[3] & 0x80) {
513                     if(message[2] == 1)
514                         memcpy(v4_prefix, prefix, 16);
515                     else
516                         memcpy(v6_prefix, prefix, 16);
517                 }
518                 /* extra data? */
519                 if((u_int)rc < len - 10)
520                     subtlvs_print(ndo, message + 12 + rc, message + 2 + len, type);
521             }
522         }
523             break;
524 
525         case MESSAGE_REQUEST: {
526             if (!ndo->ndo_vflag)
527                 ND_PRINT((ndo, " request"));
528             else {
529                 int rc;
530                 u_char prefix[16], plen;
531                 ND_PRINT((ndo, "\n\tRequest "));
532                 if(len < 2) goto invalid;
533                 plen = message[3] + (message[2] == 1 ? 96 : 0);
534                 rc = network_prefix(message[2], message[3], 0,
535                                     message + 4, NULL, len - 2, prefix);
536                 if(rc < 0) goto invalid;
537                 ND_PRINT((ndo, "for %s",
538                        message[2] == 0 ? "any" : format_prefix(ndo, prefix, plen)));
539             }
540         }
541             break;
542 
543         case MESSAGE_MH_REQUEST : {
544             if (!ndo->ndo_vflag)
545                 ND_PRINT((ndo, " mh-request"));
546             else {
547                 int rc;
548                 u_short seqno;
549                 u_char prefix[16], plen;
550                 ND_PRINT((ndo, "\n\tMH-Request "));
551                 if(len < 14) goto invalid;
552                 seqno = EXTRACT_16BITS(message + 4);
553                 rc = network_prefix(message[2], message[3], 0,
554                                     message + 16, NULL, len - 14, prefix);
555                 if(rc < 0) goto invalid;
556                 plen = message[3] + (message[2] == 1 ? 96 : 0);
557                 ND_PRINT((ndo, "(%u hops) for %s seqno %u id %s",
558                        message[6], format_prefix(ndo, prefix, plen),
559                        seqno, format_id(message + 8)));
560             }
561         }
562             break;
563         case MESSAGE_TSPC :
564             if (!ndo->ndo_vflag)
565                 ND_PRINT((ndo, " tspc"));
566             else {
567                 ND_PRINT((ndo, "\n\tTS/PC "));
568                 if(len < 6) goto invalid;
569                 ND_PRINT((ndo, "timestamp %u packetcounter %u", EXTRACT_32BITS (message + 4),
570                        EXTRACT_16BITS(message + 2)));
571             }
572             break;
573         case MESSAGE_HMAC : {
574             if (!ndo->ndo_vflag)
575                 ND_PRINT((ndo, " hmac"));
576             else {
577                 unsigned j;
578                 ND_PRINT((ndo, "\n\tHMAC "));
579                 if(len < 18) goto invalid;
580                 ND_PRINT((ndo, "key-id %u digest-%u ", EXTRACT_16BITS(message + 2), len - 2));
581                 for (j = 0; j < len - 2; j++)
582                     ND_PRINT((ndo, "%02X", message[4 + j]));
583             }
584         }
585             break;
586 
587         case MESSAGE_UPDATE_SRC_SPECIFIC : {
588             if(!ndo->ndo_vflag) {
589                 ND_PRINT((ndo, " ss-update"));
590             } else {
591                 u_char prefix[16], src_prefix[16];
592                 u_short interval, seqno, metric;
593                 u_char ae, plen, src_plen, omitted;
594                 int rc;
595                 int parsed_len = 10;
596                 ND_PRINT((ndo, "\n\tSS-Update"));
597                 if(len < 10) goto invalid;
598                 ae = message[2];
599                 src_plen = message[3];
600                 plen = message[4];
601                 omitted = message[5];
602                 interval = EXTRACT_16BITS(message + 6);
603                 seqno = EXTRACT_16BITS(message + 8);
604                 metric = EXTRACT_16BITS(message + 10);
605                 rc = network_prefix(ae, plen, omitted, message + 2 + parsed_len,
606                                     ae == 1 ? v4_prefix : v6_prefix,
607                                     len - parsed_len, prefix);
608                 if(rc < 0) goto invalid;
609                 if(ae == 1)
610                     plen += 96;
611                 parsed_len += rc;
612                 rc = network_prefix(ae, src_plen, 0, message + 2 + parsed_len,
613                                     NULL, len - parsed_len, src_prefix);
614                 if(rc < 0) goto invalid;
615                 if(ae == 1)
616                     src_plen += 96;
617                 parsed_len += rc;
618 
619                 ND_PRINT((ndo, " %s from", format_prefix(ndo, prefix, plen)));
620                 ND_PRINT((ndo, " %s metric %u seqno %u interval %s",
621                           format_prefix(ndo, src_prefix, src_plen),
622                           metric, seqno, format_interval_update(interval)));
623                 /* extra data? */
624                 if((u_int)parsed_len < len)
625                     subtlvs_print(ndo, message + 2 + parsed_len,
626                                   message + 2 + len, type);
627             }
628         }
629             break;
630 
631         case MESSAGE_REQUEST_SRC_SPECIFIC : {
632             if(!ndo->ndo_vflag)
633                 ND_PRINT((ndo, " ss-request"));
634             else {
635                 int rc, parsed_len = 3;
636                 u_char ae, plen, src_plen, prefix[16], src_prefix[16];
637                 ND_PRINT((ndo, "\n\tSS-Request "));
638                 if(len < 3) goto invalid;
639                 ae = message[2];
640                 plen = message[3];
641                 src_plen = message[4];
642                 rc = network_prefix(ae, plen, 0, message + 2 + parsed_len,
643                                     NULL, len - parsed_len, prefix);
644                 if(rc < 0) goto invalid;
645                 if(ae == 1)
646                     plen += 96;
647                 parsed_len += rc;
648                 rc = network_prefix(ae, src_plen, 0, message + 2 + parsed_len,
649                                     NULL, len - parsed_len, src_prefix);
650                 if(rc < 0) goto invalid;
651                 if(ae == 1)
652                     src_plen += 96;
653                 parsed_len += rc;
654                 if(ae == 0) {
655                     ND_PRINT((ndo, "for any"));
656                 } else {
657                     ND_PRINT((ndo, "for (%s, ", format_prefix(ndo, prefix, plen)));
658                     ND_PRINT((ndo, "%s)", format_prefix(ndo, src_prefix, src_plen)));
659                 }
660             }
661         }
662             break;
663 
664         case MESSAGE_MH_REQUEST_SRC_SPECIFIC : {
665             if(!ndo->ndo_vflag)
666                 ND_PRINT((ndo, " ss-mh-request"));
667             else {
668                 int rc, parsed_len = 14;
669                 u_short seqno;
670                 u_char ae, plen, src_plen, prefix[16], src_prefix[16], hopc;
671                 const u_char *router_id = NULL;
672                 ND_PRINT((ndo, "\n\tSS-MH-Request "));
673                 if(len < 14) goto invalid;
674                 ae = message[2];
675                 plen = message[3];
676                 seqno = EXTRACT_16BITS(message + 4);
677                 hopc = message[6];
678                 src_plen = message[7];
679                 router_id = message + 8;
680                 rc = network_prefix(ae, plen, 0, message + 2 + parsed_len,
681                                     NULL, len - parsed_len, prefix);
682                 if(rc < 0) goto invalid;
683                 if(ae == 1)
684                     plen += 96;
685                 parsed_len += rc;
686                 rc = network_prefix(ae, src_plen, 0, message + 2 + parsed_len,
687                                     NULL, len - parsed_len, src_prefix);
688                 if(rc < 0) goto invalid;
689                 if(ae == 1)
690                     src_plen += 96;
691                 ND_PRINT((ndo, "(%u hops) for (%s, ",
692                           hopc, format_prefix(ndo, prefix, plen)));
693                 ND_PRINT((ndo, "%s) seqno %u id %s",
694                           format_prefix(ndo, src_prefix, src_plen),
695                           seqno, format_id(router_id)));
696             }
697         }
698             break;
699 
700         default:
701             if (!ndo->ndo_vflag)
702                 ND_PRINT((ndo, " unknown"));
703             else
704                 ND_PRINT((ndo, "\n\tUnknown message type %d", type));
705         }
706         i += len + 2;
707     }
708     return;
709 
710  trunc:
711     ND_PRINT((ndo, " %s", tstr));
712     return;
713 
714  invalid:
715     ND_PRINT((ndo, "%s", istr));
716     return;
717 }
718