xref: /dragonfly/contrib/tcpdump/print-dccp.c (revision 59c07fbdf8168fa08c76c515186d561b5a92690c)
1 /*
2  * Copyright (C) Arnaldo Carvalho de Melo 2004
3  * Copyright (C) Ian McDonald 2005
4  * Copyright (C) Yoshifumi Nishida 2005
5  *
6  * This software may be distributed either under the terms of the
7  * BSD-style license that accompanies tcpdump or the GNU GPL version 2
8  */
9 
10 /* \summary: Datagram Congestion Control Protocol (DCCP) printer */
11 
12 /* specification: RFC 4340 */
13 
14 #ifdef HAVE_CONFIG_H
15 #include <config.h>
16 #endif
17 
18 #include "netdissect-stdinc.h"
19 
20 #include "netdissect.h"
21 #include "addrtoname.h"
22 #include "extract.h"
23 #include "ip.h"
24 #include "ip6.h"
25 #include "ipproto.h"
26 
27 /* RFC4340: Datagram Congestion Control Protocol (DCCP) */
28 
29 /**
30  * struct dccp_hdr - generic part of DCCP packet header, with a 24-bit
31  * sequence number
32  *
33  * @dccph_sport - Relevant port on the endpoint that sent this packet
34  * @dccph_dport - Relevant port on the other endpoint
35  * @dccph_doff - Data Offset from the start of the DCCP header, in 32-bit words
36  * @dccph_ccval - Used by the HC-Sender CCID
37  * @dccph_cscov - Parts of the packet that are covered by the Checksum field
38  * @dccph_checksum - Internet checksum, depends on dccph_cscov
39  * @dccph_x - 0 = 24 bit sequence number, 1 = 48
40  * @dccph_type - packet type, see DCCP_PKT_ prefixed macros
41  * @dccph_seq - 24-bit sequence number
42  */
43 struct dccp_hdr {
44           nd_uint16_t         dccph_sport,
45                               dccph_dport;
46           nd_uint8_t          dccph_doff;
47           nd_uint8_t          dccph_ccval_cscov;
48           nd_uint16_t         dccph_checksum;
49           nd_uint8_t          dccph_xtr;
50           nd_uint24_t         dccph_seq;
51 };
52 
53 /**
54  * struct dccp_hdr_ext - generic part of DCCP packet header, with a 48-bit
55  * sequence number
56  *
57  * @dccph_sport - Relevant port on the endpoint that sent this packet
58  * @dccph_dport - Relevant port on the other endpoint
59  * @dccph_doff - Data Offset from the start of the DCCP header, in 32-bit words
60  * @dccph_ccval - Used by the HC-Sender CCID
61  * @dccph_cscov - Parts of the packet that are covered by the Checksum field
62  * @dccph_checksum - Internet checksum, depends on dccph_cscov
63  * @dccph_x - 0 = 24 bit sequence number, 1 = 48
64  * @dccph_type - packet type, see DCCP_PKT_ prefixed macros
65  * @dccph_seq - 48-bit sequence number
66  */
67 struct dccp_hdr_ext {
68           nd_uint16_t         dccph_sport,
69                               dccph_dport;
70           nd_uint8_t          dccph_doff;
71           nd_uint8_t          dccph_ccval_cscov;
72           nd_uint16_t         dccph_checksum;
73           nd_uint8_t          dccph_xtr;
74           nd_uint8_t          reserved;
75           nd_uint48_t         dccph_seq;
76 };
77 
78 #define DCCPH_CCVAL(dh)       ((GET_U_1((dh)->dccph_ccval_cscov) >> 4) & 0xF)
79 #define DCCPH_CSCOV(dh)       (GET_U_1((dh)->dccph_ccval_cscov) & 0xF)
80 
81 #define DCCPH_X(dh) (GET_U_1((dh)->dccph_xtr) & 1)
82 #define DCCPH_TYPE(dh)        ((GET_U_1((dh)->dccph_xtr) >> 1) & 0xF)
83 
84 /**
85  * struct dccp_hdr_request - Connection initiation request header
86  *
87  * @dccph_req_service - Service to which the client app wants to connect
88  */
89 struct dccp_hdr_request {
90           nd_uint32_t         dccph_req_service;
91 };
92 
93 /**
94  * struct dccp_hdr_response - Connection initiation response header
95  *
96  * @dccph_resp_ack - 48 bit ack number, contains GSR
97  * @dccph_resp_service - Echoes the Service Code on a received DCCP-Request
98  */
99 struct dccp_hdr_response {
100           nd_uint64_t         dccph_resp_ack;     /* always 8 bytes, first 2 reserved */
101           nd_uint32_t         dccph_resp_service;
102 };
103 
104 /**
105  * struct dccp_hdr_reset - Unconditionally shut down a connection
106  *
107  * @dccph_resp_ack - 48 bit ack number
108  * @dccph_reset_service - Echoes the Service Code on a received DCCP-Request
109  */
110 struct dccp_hdr_reset {
111           nd_uint64_t         dccph_reset_ack;    /* always 8 bytes, first 2 reserved */
112           nd_uint8_t          dccph_reset_code;
113           nd_uint8_t          dccph_reset_data1;
114           nd_uint8_t          dccph_reset_data2;
115           nd_uint8_t          dccph_reset_data3;
116 };
117 
118 enum dccp_pkt_type {
119           DCCP_PKT_REQUEST = 0,
120           DCCP_PKT_RESPONSE,
121           DCCP_PKT_DATA,
122           DCCP_PKT_ACK,
123           DCCP_PKT_DATAACK,
124           DCCP_PKT_CLOSEREQ,
125           DCCP_PKT_CLOSE,
126           DCCP_PKT_RESET,
127           DCCP_PKT_SYNC,
128           DCCP_PKT_SYNCACK
129 };
130 
131 static const struct tok dccp_pkt_type_str[] = {
132           { DCCP_PKT_REQUEST, "DCCP-Request" },
133           { DCCP_PKT_RESPONSE, "DCCP-Response" },
134           { DCCP_PKT_DATA, "DCCP-Data" },
135           { DCCP_PKT_ACK, "DCCP-Ack" },
136           { DCCP_PKT_DATAACK, "DCCP-DataAck" },
137           { DCCP_PKT_CLOSEREQ, "DCCP-CloseReq" },
138           { DCCP_PKT_CLOSE, "DCCP-Close" },
139           { DCCP_PKT_RESET, "DCCP-Reset" },
140           { DCCP_PKT_SYNC, "DCCP-Sync" },
141           { DCCP_PKT_SYNCACK, "DCCP-SyncAck" },
142           { 0, NULL}
143 };
144 
145 enum dccp_reset_codes {
146           DCCP_RESET_CODE_UNSPECIFIED = 0,
147           DCCP_RESET_CODE_CLOSED,
148           DCCP_RESET_CODE_ABORTED,
149           DCCP_RESET_CODE_NO_CONNECTION,
150           DCCP_RESET_CODE_PACKET_ERROR,
151           DCCP_RESET_CODE_OPTION_ERROR,
152           DCCP_RESET_CODE_MANDATORY_ERROR,
153           DCCP_RESET_CODE_CONNECTION_REFUSED,
154           DCCP_RESET_CODE_BAD_SERVICE_CODE,
155           DCCP_RESET_CODE_TOO_BUSY,
156           DCCP_RESET_CODE_BAD_INIT_COOKIE,
157           DCCP_RESET_CODE_AGGRESSION_PENALTY,
158           __DCCP_RESET_CODE_LAST
159 };
160 
161 
162 static const char *dccp_reset_codes[] = {
163           "unspecified",
164           "closed",
165           "aborted",
166           "no_connection",
167           "packet_error",
168           "option_error",
169           "mandatory_error",
170           "connection_refused",
171           "bad_service_code",
172           "too_busy",
173           "bad_init_cookie",
174           "aggression_penalty",
175 };
176 
177 static const char *dccp_feature_nums[] = {
178           "reserved",
179           "ccid",
180           "allow_short_seqno",
181           "sequence_window",
182           "ecn_incapable",
183           "ack_ratio",
184           "send_ack_vector",
185           "send_ndp_count",
186           "minimum checksum coverage",
187           "check data checksum",
188 };
189 
190 static u_int
dccp_csum_coverage(netdissect_options * ndo,const struct dccp_hdr * dh,u_int len)191 dccp_csum_coverage(netdissect_options *ndo,
192                        const struct dccp_hdr* dh, u_int len)
193 {
194           u_int cov;
195 
196           if (DCCPH_CSCOV(dh) == 0)
197                     return len;
198           cov = (GET_U_1(dh->dccph_doff) + DCCPH_CSCOV(dh) - 1) * sizeof(uint32_t);
199           return (cov > len)? len : cov;
200 }
201 
dccp_cksum(netdissect_options * ndo,const struct ip * ip,const struct dccp_hdr * dh,u_int len)202 static uint16_t dccp_cksum(netdissect_options *ndo, const struct ip *ip,
203           const struct dccp_hdr *dh, u_int len)
204 {
205           return nextproto4_cksum(ndo, ip, (const uint8_t *)(const void *)dh, len,
206                                         dccp_csum_coverage(ndo, dh, len), IPPROTO_DCCP);
207 }
208 
dccp6_cksum(netdissect_options * ndo,const struct ip6_hdr * ip6,const struct dccp_hdr * dh,u_int len)209 static uint16_t dccp6_cksum(netdissect_options *ndo, const struct ip6_hdr *ip6,
210           const struct dccp_hdr *dh, u_int len)
211 {
212           return nextproto6_cksum(ndo, ip6, (const uint8_t *)(const void *)dh, len,
213                                         dccp_csum_coverage(ndo, dh, len), IPPROTO_DCCP);
214 }
215 
dccp_reset_code(uint8_t code)216 static const char *dccp_reset_code(uint8_t code)
217 {
218           if (code >= __DCCP_RESET_CODE_LAST)
219                     return "invalid";
220           return dccp_reset_codes[code];
221 }
222 
223 static uint64_t
dccp_seqno(netdissect_options * ndo,const u_char * bp)224 dccp_seqno(netdissect_options *ndo, const u_char *bp)
225 {
226           const struct dccp_hdr *dh = (const struct dccp_hdr *)bp;
227           uint64_t seqno;
228 
229           if (DCCPH_X(dh) != 0) {
230                     const struct dccp_hdr_ext *dhx = (const struct dccp_hdr_ext *)bp;
231                     seqno = GET_BE_U_6(dhx->dccph_seq);
232           } else {
233                     seqno = GET_BE_U_3(dh->dccph_seq);
234           }
235 
236           return seqno;
237 }
238 
239 static unsigned int
dccp_basic_hdr_len(netdissect_options * ndo,const struct dccp_hdr * dh)240 dccp_basic_hdr_len(netdissect_options *ndo, const struct dccp_hdr *dh)
241 {
242           return DCCPH_X(dh) ? sizeof(struct dccp_hdr_ext) : sizeof(struct dccp_hdr);
243 }
244 
dccp_print_ack_no(netdissect_options * ndo,const u_char * bp)245 static void dccp_print_ack_no(netdissect_options *ndo, const u_char *bp)
246 {
247           const struct dccp_hdr *dh = (const struct dccp_hdr *)bp;
248           const u_char *ackp = bp + dccp_basic_hdr_len(ndo, dh);
249           uint64_t ackno;
250 
251           if (DCCPH_X(dh) != 0) {
252                     ackno = GET_BE_U_6(ackp + 2);
253           } else {
254                     ackno = GET_BE_U_3(ackp + 1);
255           }
256 
257           ND_PRINT("(ack=%" PRIu64 ") ", ackno);
258 }
259 
260 static u_int dccp_print_option(netdissect_options *, const u_char *, u_int);
261 
262 /**
263  * dccp_print - show dccp packet
264  * @bp - beginning of dccp packet
265  * @data2 - beginning of enclosing
266  * @len - length of ip packet
267  */
268 void
dccp_print(netdissect_options * ndo,const u_char * bp,const u_char * data2,u_int len)269 dccp_print(netdissect_options *ndo, const u_char *bp, const u_char *data2,
270              u_int len)
271 {
272           const struct dccp_hdr *dh;
273           const struct ip *ip;
274           const struct ip6_hdr *ip6;
275           const u_char *cp;
276           u_short sport, dport;
277           u_int hlen;
278           u_int fixed_hdrlen;
279           uint8_t   dccph_type;
280 
281           ndo->ndo_protocol = "dccp";
282           dh = (const struct dccp_hdr *)bp;
283 
284           ip = (const struct ip *)data2;
285           if (IP_V(ip) == 6)
286                     ip6 = (const struct ip6_hdr *)data2;
287           else
288                     ip6 = NULL;
289 
290           /* make sure we have enough data to look at the X bit */
291           cp = (const u_char *)(dh + 1);
292           if (cp > ndo->ndo_snapend)
293                     goto trunc;
294           if (len < sizeof(struct dccp_hdr)) {
295                     ND_PRINT("truncated-dccp - %zu bytes missing!",
296                                sizeof(struct dccp_hdr) - len);
297                     return;
298           }
299 
300           /* get the length of the generic header */
301           fixed_hdrlen = dccp_basic_hdr_len(ndo, dh);
302           if (len < fixed_hdrlen) {
303                     ND_PRINT("truncated-dccp - %u bytes missing!",
304                                 fixed_hdrlen - len);
305                     return;
306           }
307           ND_TCHECK_LEN(dh, fixed_hdrlen);
308 
309           sport = GET_BE_U_2(dh->dccph_sport);
310           dport = GET_BE_U_2(dh->dccph_dport);
311           hlen = GET_U_1(dh->dccph_doff) * 4;
312 
313           if (ip6) {
314                     ND_PRINT("%s.%u > %s.%u: ",
315                                 GET_IP6ADDR_STRING(ip6->ip6_src), sport,
316                                 GET_IP6ADDR_STRING(ip6->ip6_dst), dport);
317           } else {
318                     ND_PRINT("%s.%u > %s.%u: ",
319                                 GET_IPADDR_STRING(ip->ip_src), sport,
320                                 GET_IPADDR_STRING(ip->ip_dst), dport);
321           }
322 
323           nd_print_protocol_caps(ndo);
324 
325           if (ndo->ndo_qflag) {
326                     ND_PRINT(" %u", len - hlen);
327                     if (hlen > len) {
328                               ND_PRINT(" [bad hdr length %u - too long, > %u]",
329                                           hlen, len);
330                     }
331                     return;
332           }
333 
334           /* other variables in generic header */
335           if (ndo->ndo_vflag) {
336                     ND_PRINT(" (CCVal %u, CsCov %u, ", DCCPH_CCVAL(dh), DCCPH_CSCOV(dh));
337           }
338 
339           /* checksum calculation */
340           if (ndo->ndo_vflag && ND_TTEST_LEN(bp, len)) {
341                     uint16_t sum = 0, dccp_sum;
342 
343                     dccp_sum = GET_BE_U_2(dh->dccph_checksum);
344                     ND_PRINT("cksum 0x%04x ", dccp_sum);
345                     if (IP_V(ip) == 4)
346                               sum = dccp_cksum(ndo, ip, dh, len);
347                     else if (IP_V(ip) == 6)
348                               sum = dccp6_cksum(ndo, ip6, dh, len);
349                     if (sum != 0)
350                               ND_PRINT("(incorrect -> 0x%04x)",in_cksum_shouldbe(dccp_sum, sum));
351                     else
352                               ND_PRINT("(correct)");
353           }
354 
355           if (ndo->ndo_vflag)
356                     ND_PRINT(")");
357           ND_PRINT(" ");
358 
359           dccph_type = DCCPH_TYPE(dh);
360           switch (dccph_type) {
361           case DCCP_PKT_REQUEST: {
362                     const struct dccp_hdr_request *dhr =
363                               (const struct dccp_hdr_request *)(bp + fixed_hdrlen);
364                     fixed_hdrlen += 4;
365                     if (len < fixed_hdrlen) {
366                               ND_PRINT("truncated-%s - %u bytes missing!",
367                                           tok2str(dccp_pkt_type_str, "", dccph_type),
368                                           fixed_hdrlen - len);
369                               return;
370                     }
371                     ND_TCHECK_SIZE(dhr);
372                     ND_PRINT("%s (service=%u) ",
373                                 tok2str(dccp_pkt_type_str, "", dccph_type),
374                                 GET_BE_U_4(dhr->dccph_req_service));
375                     break;
376           }
377           case DCCP_PKT_RESPONSE: {
378                     const struct dccp_hdr_response *dhr =
379                               (const struct dccp_hdr_response *)(bp + fixed_hdrlen);
380                     fixed_hdrlen += 12;
381                     if (len < fixed_hdrlen) {
382                               ND_PRINT("truncated-%s - %u bytes missing!",
383                                           tok2str(dccp_pkt_type_str, "", dccph_type),
384                                           fixed_hdrlen - len);
385                               return;
386                     }
387                     ND_TCHECK_SIZE(dhr);
388                     ND_PRINT("%s (service=%u) ",
389                                 tok2str(dccp_pkt_type_str, "", dccph_type),
390                                 GET_BE_U_4(dhr->dccph_resp_service));
391                     break;
392           }
393           case DCCP_PKT_DATA:
394                     ND_PRINT("%s ", tok2str(dccp_pkt_type_str, "", dccph_type));
395                     break;
396           case DCCP_PKT_ACK: {
397                     fixed_hdrlen += 8;
398                     if (len < fixed_hdrlen) {
399                               ND_PRINT("truncated-%s - %u bytes missing!",
400                                           tok2str(dccp_pkt_type_str, "", dccph_type),
401                                           fixed_hdrlen - len);
402                               return;
403                     }
404                     ND_PRINT("%s ", tok2str(dccp_pkt_type_str, "", dccph_type));
405                     break;
406           }
407           case DCCP_PKT_DATAACK: {
408                     fixed_hdrlen += 8;
409                     if (len < fixed_hdrlen) {
410                               ND_PRINT("truncated-%s - %u bytes missing!",
411                                           tok2str(dccp_pkt_type_str, "", dccph_type),
412                                           fixed_hdrlen - len);
413                               return;
414                     }
415                     ND_PRINT("%s ", tok2str(dccp_pkt_type_str, "", dccph_type));
416                     break;
417           }
418           case DCCP_PKT_CLOSEREQ:
419                     fixed_hdrlen += 8;
420                     if (len < fixed_hdrlen) {
421                               ND_PRINT("truncated-%s - %u bytes missing!",
422                                           tok2str(dccp_pkt_type_str, "", dccph_type),
423                                           fixed_hdrlen - len);
424                               return;
425                     }
426                     ND_PRINT("%s ", tok2str(dccp_pkt_type_str, "", dccph_type));
427                     break;
428           case DCCP_PKT_CLOSE:
429                     fixed_hdrlen += 8;
430                     if (len < fixed_hdrlen) {
431                               ND_PRINT("truncated-%s - %u bytes missing!",
432                                           tok2str(dccp_pkt_type_str, "", dccph_type),
433                                           fixed_hdrlen - len);
434                               return;
435                     }
436                     ND_PRINT("%s ", tok2str(dccp_pkt_type_str, "", dccph_type));
437                     break;
438           case DCCP_PKT_RESET: {
439                     const struct dccp_hdr_reset *dhr =
440                               (const struct dccp_hdr_reset *)(bp + fixed_hdrlen);
441                     fixed_hdrlen += 12;
442                     if (len < fixed_hdrlen) {
443                               ND_PRINT("truncated-%s - %u bytes missing!",
444                                           tok2str(dccp_pkt_type_str, "", dccph_type),
445                                           fixed_hdrlen - len);
446                               return;
447                     }
448                     ND_TCHECK_SIZE(dhr);
449                     ND_PRINT("%s (code=%s) ",
450                                 tok2str(dccp_pkt_type_str, "", dccph_type),
451                                 dccp_reset_code(GET_U_1(dhr->dccph_reset_code)));
452                     break;
453           }
454           case DCCP_PKT_SYNC:
455                     fixed_hdrlen += 8;
456                     if (len < fixed_hdrlen) {
457                               ND_PRINT("truncated-%s - %u bytes missing!",
458                                           tok2str(dccp_pkt_type_str, "", dccph_type),
459                                           fixed_hdrlen - len);
460                               return;
461                     }
462                     ND_PRINT("%s ", tok2str(dccp_pkt_type_str, "", dccph_type));
463                     break;
464           case DCCP_PKT_SYNCACK:
465                     fixed_hdrlen += 8;
466                     if (len < fixed_hdrlen) {
467                               ND_PRINT("truncated-%s - %u bytes missing!",
468                                           tok2str(dccp_pkt_type_str, "", dccph_type),
469                                           fixed_hdrlen - len);
470                               return;
471                     }
472                     ND_PRINT("%s ", tok2str(dccp_pkt_type_str, "", dccph_type));
473                     break;
474           default:
475                     ND_PRINT("%s ", tok2str(dccp_pkt_type_str, "unknown-type-%u", dccph_type));
476                     break;
477           }
478 
479           if ((DCCPH_TYPE(dh) != DCCP_PKT_DATA) &&
480                               (DCCPH_TYPE(dh) != DCCP_PKT_REQUEST))
481                     dccp_print_ack_no(ndo, bp);
482 
483           if (ndo->ndo_vflag < 2)
484                     return;
485 
486           ND_PRINT("seq %" PRIu64, dccp_seqno(ndo, bp));
487 
488           /* process options */
489           if (hlen > fixed_hdrlen){
490                     u_int optlen;
491                     cp = bp + fixed_hdrlen;
492                     ND_PRINT(" <");
493 
494                     hlen -= fixed_hdrlen;
495                     while(1){
496                               optlen = dccp_print_option(ndo, cp, hlen);
497                               if (!optlen)
498                                         break;
499                               if (hlen <= optlen)
500                                         break;
501                               hlen -= optlen;
502                               cp += optlen;
503                               ND_PRINT(", ");
504                     }
505                     ND_PRINT(">");
506           }
507           return;
508 trunc:
509           nd_print_trunc(ndo);
510 }
511 
512 static const struct tok dccp_option_values[] = {
513           { 0, "nop" },
514           { 1, "mandatory" },
515           { 2, "slowreceiver" },
516           { 32, "change_l" },
517           { 33, "confirm_l" },
518           { 34, "change_r" },
519           { 35, "confirm_r" },
520           { 36, "initcookie" },
521           { 37, "ndp_count" },
522           { 38, "ack_vector0" },
523           { 39, "ack_vector1" },
524           { 40, "data_dropped" },
525           { 41, "timestamp" },
526           { 42, "timestamp_echo" },
527           { 43, "elapsed_time" },
528           { 44, "data_checksum" },
529           { 0, NULL }
530 };
531 
532 static u_int
dccp_print_option(netdissect_options * ndo,const u_char * option,u_int hlen)533 dccp_print_option(netdissect_options *ndo, const u_char *option, u_int hlen)
534 {
535           uint8_t optlen, i;
536 
537           if (GET_U_1(option) >= 32) {
538                     optlen = GET_U_1(option + 1);
539                     if (optlen < 2) {
540                               if (GET_U_1(option) >= 128)
541                                         ND_PRINT("CCID option %u optlen too short",
542                                                    GET_U_1(option));
543                               else
544                                         ND_PRINT("%s optlen too short",
545                                                     tok2str(dccp_option_values, "Option %u", GET_U_1(option)));
546                               return 0;
547                     }
548           } else
549                     optlen = 1;
550 
551           if (hlen < optlen) {
552                     if (GET_U_1(option) >= 128)
553                               ND_PRINT("CCID option %u optlen goes past header length",
554                                           GET_U_1(option));
555                     else
556                               ND_PRINT("%s optlen goes past header length",
557                                           tok2str(dccp_option_values, "Option %u", GET_U_1(option)));
558                     return 0;
559           }
560           ND_TCHECK_LEN(option, optlen);
561 
562           if (GET_U_1(option) >= 128) {
563                     ND_PRINT("CCID option %u", GET_U_1(option));
564                     switch (optlen) {
565                               case 4:
566                                         ND_PRINT(" %u", GET_BE_U_2(option + 2));
567                                         break;
568                               case 6:
569                                         ND_PRINT(" %u", GET_BE_U_4(option + 2));
570                                         break;
571                               default:
572                                         break;
573                     }
574           } else {
575                     ND_PRINT("%s",
576                                tok2str(dccp_option_values, "Option %u", GET_U_1(option)));
577                     switch (GET_U_1(option)) {
578                     case 32:
579                     case 33:
580                     case 34:
581                     case 35:
582                               if (optlen < 3) {
583                                         ND_PRINT(" optlen too short");
584                                         return optlen;
585                               }
586                               if (GET_U_1(option + 2) < 10){
587                                         ND_PRINT(" %s",
588                                                    dccp_feature_nums[GET_U_1(option + 2)]);
589                                         for (i = 0; i < optlen - 3; i++)
590                                                   ND_PRINT(" %u",
591                                                              GET_U_1(option + 3 + i));
592                               }
593                               break;
594                     case 36:
595                               if (optlen > 2) {
596                                         ND_PRINT(" 0x");
597                                         for (i = 0; i < optlen - 2; i++)
598                                                   ND_PRINT("%02x",
599                                                              GET_U_1(option + 2 + i));
600                               }
601                               break;
602                     case 37:
603                               for (i = 0; i < optlen - 2; i++)
604                                         ND_PRINT(" %u", GET_U_1(option + 2 + i));
605                               break;
606                     case 38:
607                               if (optlen > 2) {
608                                         ND_PRINT(" 0x");
609                                         for (i = 0; i < optlen - 2; i++)
610                                                   ND_PRINT("%02x",
611                                                              GET_U_1(option + 2 + i));
612                               }
613                               break;
614                     case 39:
615                               if (optlen > 2) {
616                                         ND_PRINT(" 0x");
617                                         for (i = 0; i < optlen - 2; i++)
618                                                   ND_PRINT("%02x",
619                                                              GET_U_1(option + 2 + i));
620                               }
621                               break;
622                     case 40:
623                               if (optlen > 2) {
624                                         ND_PRINT(" 0x");
625                                         for (i = 0; i < optlen - 2; i++)
626                                                   ND_PRINT("%02x",
627                                                              GET_U_1(option + 2 + i));
628                               }
629                               break;
630                     case 41:
631                     /*
632                      * 13.1.  Timestamp Option
633                      *
634                      *  +--------+--------+--------+--------+--------+--------+
635                      *  |00101001|00000110|          Timestamp Value          |
636                      *  +--------+--------+--------+--------+--------+--------+
637                      *   Type=41  Length=6
638                      */
639                               if (optlen == 6)
640                                         ND_PRINT(" %u", GET_BE_U_4(option + 2));
641                               else
642                                         ND_PRINT(" [optlen != 6]");
643                               break;
644                     case 42:
645                     /*
646                      * 13.3.  Timestamp Echo Option
647                      *
648                      *  +--------+--------+--------+--------+--------+--------+
649                      *  |00101010|00000110|           Timestamp Echo          |
650                      *  +--------+--------+--------+--------+--------+--------+
651                      *   Type=42    Len=6
652                      *
653                      *  +--------+--------+------- ... -------+--------+--------+
654                      *  |00101010|00001000|  Timestamp Echo   |   Elapsed Time  |
655                      *  +--------+--------+------- ... -------+--------+--------+
656                      *   Type=42    Len=8       (4 bytes)
657                      *
658                      *  +--------+--------+------- ... -------+------- ... -------+
659                      *  |00101010|00001010|  Timestamp Echo   |    Elapsed Time   |
660                      *  +--------+--------+------- ... -------+------- ... -------+
661                      *   Type=42   Len=10       (4 bytes)           (4 bytes)
662                      */
663                               switch (optlen) {
664                               case 6:
665                                         ND_PRINT(" %u", GET_BE_U_4(option + 2));
666                                         break;
667                               case 8:
668                                         ND_PRINT(" %u", GET_BE_U_4(option + 2));
669                                         ND_PRINT(" (elapsed time %u)",
670                                                    GET_BE_U_2(option + 6));
671                                         break;
672                               case 10:
673                                         ND_PRINT(" %u", GET_BE_U_4(option + 2));
674                                         ND_PRINT(" (elapsed time %u)",
675                                                    GET_BE_U_4(option + 6));
676                                         break;
677                               default:
678                                         ND_PRINT(" [optlen != 6 or 8 or 10]");
679                                         break;
680                               }
681                               break;
682                     case 43:
683                               if (optlen == 6)
684                                         ND_PRINT(" %u", GET_BE_U_4(option + 2));
685                               else if (optlen == 4)
686                                         ND_PRINT(" %u", GET_BE_U_2(option + 2));
687                               else
688                                         ND_PRINT(" [optlen != 4 or 6]");
689                               break;
690                     case 44:
691                               if (optlen > 2) {
692                                         ND_PRINT(" ");
693                                         for (i = 0; i < optlen - 2; i++)
694                                                   ND_PRINT("%02x",
695                                                              GET_U_1(option + 2 + i));
696                               }
697                               break;
698                     }
699           }
700 
701           return optlen;
702 trunc:
703           nd_print_trunc(ndo);
704           return 0;
705 }
706