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DCCP: Fix a truncation message
[tcpdump] / print-dccp.c
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 <stdio.h>
21 #include <string.h>
22
23 #include "netdissect.h"
24 #include "addrtoname.h"
25 #include "extract.h"
26 #include "ip.h"
27 #include "ip6.h"
28 #include "ipproto.h"
29
30 /* RFC4340: Datagram Congestion Control Protocol (DCCP) */
31
32 /**
33 * struct dccp_hdr - generic part of DCCP packet header, with a 24-bit
34 * sequence number
35 *
36 * @dccph_sport - Relevant port on the endpoint that sent this packet
37 * @dccph_dport - Relevant port on the other endpoint
38 * @dccph_doff - Data Offset from the start of the DCCP header, in 32-bit words
39 * @dccph_ccval - Used by the HC-Sender CCID
40 * @dccph_cscov - Parts of the packet that are covered by the Checksum field
41 * @dccph_checksum - Internet checksum, depends on dccph_cscov
42 * @dccph_x - 0 = 24 bit sequence number, 1 = 48
43 * @dccph_type - packet type, see DCCP_PKT_ prefixed macros
44 * @dccph_seq - 24-bit sequence number
45 */
46 struct dccp_hdr {
47 nd_uint16_t dccph_sport,
48 dccph_dport;
49 nd_uint8_t dccph_doff;
50 nd_uint8_t dccph_ccval_cscov;
51 nd_uint16_t dccph_checksum;
52 nd_uint8_t dccph_xtr;
53 nd_uint24_t dccph_seq;
54 };
55
56 /**
57 * struct dccp_hdr_ext - generic part of DCCP packet header, with a 48-bit
58 * sequence number
59 *
60 * @dccph_sport - Relevant port on the endpoint that sent this packet
61 * @dccph_dport - Relevant port on the other endpoint
62 * @dccph_doff - Data Offset from the start of the DCCP header, in 32-bit words
63 * @dccph_ccval - Used by the HC-Sender CCID
64 * @dccph_cscov - Parts of the packet that are covered by the Checksum field
65 * @dccph_checksum - Internet checksum, depends on dccph_cscov
66 * @dccph_x - 0 = 24 bit sequence number, 1 = 48
67 * @dccph_type - packet type, see DCCP_PKT_ prefixed macros
68 * @dccph_seq - 48-bit sequence number
69 */
70 struct dccp_hdr_ext {
71 nd_uint16_t dccph_sport,
72 dccph_dport;
73 nd_uint8_t dccph_doff;
74 nd_uint8_t dccph_ccval_cscov;
75 nd_uint16_t dccph_checksum;
76 nd_uint8_t dccph_xtr;
77 nd_uint8_t reserved;
78 nd_uint48_t dccph_seq;
79 };
80
81 #define DCCPH_CCVAL(dh) ((EXTRACT_U_1((dh)->dccph_ccval_cscov) >> 4) & 0xF)
82 #define DCCPH_CSCOV(dh) (EXTRACT_U_1((dh)->dccph_ccval_cscov) & 0xF)
83
84 #define DCCPH_X(dh) (EXTRACT_U_1((dh)->dccph_xtr) & 1)
85 #define DCCPH_TYPE(dh) ((EXTRACT_U_1((dh)->dccph_xtr) >> 1) & 0xF)
86
87 /**
88 * struct dccp_hdr_request - Conection initiation request header
89 *
90 * @dccph_req_service - Service to which the client app wants to connect
91 */
92 struct dccp_hdr_request {
93 nd_uint32_t dccph_req_service;
94 };
95
96 /**
97 * struct dccp_hdr_response - Conection initiation response header
98 *
99 * @dccph_resp_ack - 48 bit ack number, contains GSR
100 * @dccph_resp_service - Echoes the Service Code on a received DCCP-Request
101 */
102 struct dccp_hdr_response {
103 nd_uint64_t dccph_resp_ack; /* always 8 bytes, first 2 reserved */
104 nd_uint32_t dccph_resp_service;
105 };
106
107 /**
108 * struct dccp_hdr_reset - Unconditionally shut down a connection
109 *
110 * @dccph_resp_ack - 48 bit ack number
111 * @dccph_reset_service - Echoes the Service Code on a received DCCP-Request
112 */
113 struct dccp_hdr_reset {
114 nd_uint64_t dccph_reset_ack; /* always 8 bytes, first 2 reserved */
115 nd_uint8_t dccph_reset_code;
116 nd_uint8_t dccph_reset_data1;
117 nd_uint8_t dccph_reset_data2;
118 nd_uint8_t dccph_reset_data3;
119 };
120
121 enum dccp_pkt_type {
122 DCCP_PKT_REQUEST = 0,
123 DCCP_PKT_RESPONSE,
124 DCCP_PKT_DATA,
125 DCCP_PKT_ACK,
126 DCCP_PKT_DATAACK,
127 DCCP_PKT_CLOSEREQ,
128 DCCP_PKT_CLOSE,
129 DCCP_PKT_RESET,
130 DCCP_PKT_SYNC,
131 DCCP_PKT_SYNCACK
132 };
133
134 static const struct tok dccp_pkt_type_str[] = {
135 { DCCP_PKT_REQUEST, "DCCP-Request" },
136 { DCCP_PKT_RESPONSE, "DCCP-Response" },
137 { DCCP_PKT_DATA, "DCCP-Data" },
138 { DCCP_PKT_ACK, "DCCP-Ack" },
139 { DCCP_PKT_DATAACK, "DCCP-DataAck" },
140 { DCCP_PKT_CLOSEREQ, "DCCP-CloseReq" },
141 { DCCP_PKT_CLOSE, "DCCP-Close" },
142 { DCCP_PKT_RESET, "DCCP-Reset" },
143 { DCCP_PKT_SYNC, "DCCP-Sync" },
144 { DCCP_PKT_SYNCACK, "DCCP-SyncAck" },
145 { 0, NULL}
146 };
147
148 enum dccp_reset_codes {
149 DCCP_RESET_CODE_UNSPECIFIED = 0,
150 DCCP_RESET_CODE_CLOSED,
151 DCCP_RESET_CODE_ABORTED,
152 DCCP_RESET_CODE_NO_CONNECTION,
153 DCCP_RESET_CODE_PACKET_ERROR,
154 DCCP_RESET_CODE_OPTION_ERROR,
155 DCCP_RESET_CODE_MANDATORY_ERROR,
156 DCCP_RESET_CODE_CONNECTION_REFUSED,
157 DCCP_RESET_CODE_BAD_SERVICE_CODE,
158 DCCP_RESET_CODE_TOO_BUSY,
159 DCCP_RESET_CODE_BAD_INIT_COOKIE,
160 DCCP_RESET_CODE_AGGRESSION_PENALTY,
161 __DCCP_RESET_CODE_LAST
162 };
163
164
165 static const char *dccp_reset_codes[] = {
166 "unspecified",
167 "closed",
168 "aborted",
169 "no_connection",
170 "packet_error",
171 "option_error",
172 "mandatory_error",
173 "connection_refused",
174 "bad_service_code",
175 "too_busy",
176 "bad_init_cookie",
177 "aggression_penalty",
178 };
179
180 static const char *dccp_feature_nums[] = {
181 "reserved",
182 "ccid",
183 "allow_short_seqno",
184 "sequence_window",
185 "ecn_incapable",
186 "ack_ratio",
187 "send_ack_vector",
188 "send_ndp_count",
189 "minimum checksum coverage",
190 "check data checksum",
191 };
192
193 static u_int
194 dccp_csum_coverage(const struct dccp_hdr* dh, u_int len)
195 {
196 u_int cov;
197
198 if (DCCPH_CSCOV(dh) == 0)
199 return len;
200 cov = (EXTRACT_U_1(dh->dccph_doff) + DCCPH_CSCOV(dh) - 1) * sizeof(uint32_t);
201 return (cov > len)? len : cov;
202 }
203
204 static int dccp_cksum(netdissect_options *ndo, const struct ip *ip,
205 const struct dccp_hdr *dh, u_int len)
206 {
207 return nextproto4_cksum(ndo, ip, (const uint8_t *)(const void *)dh, len,
208 dccp_csum_coverage(dh, len), IPPROTO_DCCP);
209 }
210
211 static int dccp6_cksum(netdissect_options *ndo, const struct ip6_hdr *ip6,
212 const struct dccp_hdr *dh, u_int len)
213 {
214 return nextproto6_cksum(ndo, ip6, (const uint8_t *)(const void *)dh, len,
215 dccp_csum_coverage(dh, len), IPPROTO_DCCP);
216 }
217
218 static const char *dccp_reset_code(uint8_t code)
219 {
220 if (code >= __DCCP_RESET_CODE_LAST)
221 return "invalid";
222 return dccp_reset_codes[code];
223 }
224
225 static uint64_t dccp_seqno(const u_char *bp)
226 {
227 const struct dccp_hdr *dh = (const struct dccp_hdr *)bp;
228 uint64_t seqno;
229
230 if (DCCPH_X(dh) != 0) {
231 const struct dccp_hdr_ext *dhx = (const struct dccp_hdr_ext *)bp;
232 seqno = EXTRACT_BE_U_6(dhx->dccph_seq);
233 } else {
234 seqno = EXTRACT_BE_U_3(dh->dccph_seq);
235 }
236
237 return seqno;
238 }
239
240 static unsigned int
241 dccp_basic_hdr_len(const struct dccp_hdr *dh)
242 {
243 return DCCPH_X(dh) ? sizeof(struct dccp_hdr_ext) : sizeof(struct dccp_hdr);
244 }
245
246 static void dccp_print_ack_no(netdissect_options *ndo, const u_char *bp)
247 {
248 const struct dccp_hdr *dh = (const struct dccp_hdr *)bp;
249 const u_char *ackp = bp + dccp_basic_hdr_len(dh);
250 uint64_t ackno;
251
252 if (DCCPH_X(dh) != 0) {
253 ND_TCHECK_8(ackp);
254 ackno = EXTRACT_BE_U_6(ackp + 2);
255 } else {
256 ND_TCHECK_4(ackp);
257 ackno = EXTRACT_BE_U_3(ackp + 1);
258 }
259
260 ND_PRINT("(ack=%" PRIu64 ") ", ackno);
261 trunc:
262 return;
263 }
264
265 static u_int dccp_print_option(netdissect_options *, const u_char *, u_int);
266
267 /**
268 * dccp_print - show dccp packet
269 * @bp - beginning of dccp packet
270 * @data2 - beginning of enclosing
271 * @len - lenght of ip packet
272 */
273 void
274 dccp_print(netdissect_options *ndo, const u_char *bp, const u_char *data2,
275 u_int len)
276 {
277 const struct dccp_hdr *dh;
278 const struct ip *ip;
279 const struct ip6_hdr *ip6;
280 const u_char *cp;
281 u_short sport, dport;
282 u_int hlen;
283 u_int fixed_hdrlen;
284 uint8_t dccph_type;
285
286 ndo->ndo_protocol = "dccp";
287 dh = (const struct dccp_hdr *)bp;
288
289 ip = (const struct ip *)data2;
290 if (IP_V(ip) == 6)
291 ip6 = (const struct ip6_hdr *)data2;
292 else
293 ip6 = NULL;
294
295 /* make sure we have enough data to look at the X bit */
296 cp = (const u_char *)(dh + 1);
297 if (cp > ndo->ndo_snapend)
298 goto trunc;
299 if (len < sizeof(struct dccp_hdr)) {
300 ND_PRINT("truncated-dccp - %u bytes missing!",
301 len - (u_int)sizeof(struct dccp_hdr));
302 return;
303 }
304
305 /* get the length of the generic header */
306 fixed_hdrlen = dccp_basic_hdr_len(dh);
307 if (len < fixed_hdrlen) {
308 ND_PRINT("truncated-dccp - %u bytes missing!",
309 len - fixed_hdrlen);
310 return;
311 }
312 ND_TCHECK_LEN(dh, fixed_hdrlen);
313
314 sport = EXTRACT_BE_U_2(dh->dccph_sport);
315 dport = EXTRACT_BE_U_2(dh->dccph_dport);
316 hlen = EXTRACT_U_1(dh->dccph_doff) * 4;
317
318 if (ip6) {
319 ND_PRINT("%s.%u > %s.%u: ",
320 ip6addr_string(ndo, ip6->ip6_src), sport,
321 ip6addr_string(ndo, ip6->ip6_dst), dport);
322 } else {
323 ND_PRINT("%s.%u > %s.%u: ",
324 ipaddr_string(ndo, ip->ip_src), sport,
325 ipaddr_string(ndo, ip->ip_dst), dport);
326 }
327
328 ND_PRINT("DCCP");
329
330 if (ndo->ndo_qflag) {
331 ND_PRINT(" %u", len - hlen);
332 if (hlen > len) {
333 ND_PRINT(" [bad hdr length %u - too long, > %u]",
334 hlen, len);
335 }
336 return;
337 }
338
339 /* other variables in generic header */
340 if (ndo->ndo_vflag) {
341 ND_PRINT(" (CCVal %u, CsCov %u, ", DCCPH_CCVAL(dh), DCCPH_CSCOV(dh));
342 }
343
344 /* checksum calculation */
345 if (ndo->ndo_vflag && ND_TTEST_LEN(bp, len)) {
346 uint16_t sum = 0, dccp_sum;
347
348 dccp_sum = EXTRACT_BE_U_2(dh->dccph_checksum);
349 ND_PRINT("cksum 0x%04x ", dccp_sum);
350 if (IP_V(ip) == 4)
351 sum = dccp_cksum(ndo, ip, dh, len);
352 else if (IP_V(ip) == 6)
353 sum = dccp6_cksum(ndo, ip6, dh, len);
354 if (sum != 0)
355 ND_PRINT("(incorrect -> 0x%04x)",in_cksum_shouldbe(dccp_sum, sum));
356 else
357 ND_PRINT("(correct)");
358 }
359
360 if (ndo->ndo_vflag)
361 ND_PRINT(")");
362 ND_PRINT(" ");
363
364 dccph_type = DCCPH_TYPE(dh);
365 switch (dccph_type) {
366 case DCCP_PKT_REQUEST: {
367 const struct dccp_hdr_request *dhr =
368 (const struct dccp_hdr_request *)(bp + fixed_hdrlen);
369 fixed_hdrlen += 4;
370 if (len < fixed_hdrlen) {
371 ND_PRINT("truncated-%s - %u bytes missing!",
372 tok2str(dccp_pkt_type_str, "", dccph_type),
373 len - fixed_hdrlen);
374 return;
375 }
376 ND_TCHECK_SIZE(dhr);
377 ND_PRINT("%s (service=%u) ",
378 tok2str(dccp_pkt_type_str, "", dccph_type),
379 EXTRACT_BE_U_4(dhr->dccph_req_service));
380 break;
381 }
382 case DCCP_PKT_RESPONSE: {
383 const struct dccp_hdr_response *dhr =
384 (const struct dccp_hdr_response *)(bp + fixed_hdrlen);
385 fixed_hdrlen += 12;
386 if (len < fixed_hdrlen) {
387 ND_PRINT("truncated-%s - %u bytes missing!",
388 tok2str(dccp_pkt_type_str, "", dccph_type),
389 len - fixed_hdrlen);
390 return;
391 }
392 ND_TCHECK_SIZE(dhr);
393 ND_PRINT("%s (service=%u) ",
394 tok2str(dccp_pkt_type_str, "", dccph_type),
395 EXTRACT_BE_U_4(dhr->dccph_resp_service));
396 break;
397 }
398 case DCCP_PKT_DATA:
399 ND_PRINT("%s ", tok2str(dccp_pkt_type_str, "", dccph_type));
400 break;
401 case DCCP_PKT_ACK: {
402 fixed_hdrlen += 8;
403 if (len < fixed_hdrlen) {
404 ND_PRINT("truncated-%s - %u bytes missing!",
405 tok2str(dccp_pkt_type_str, "", dccph_type),
406 len - fixed_hdrlen);
407 return;
408 }
409 ND_PRINT("%s ", tok2str(dccp_pkt_type_str, "", dccph_type));
410 break;
411 }
412 case DCCP_PKT_DATAACK: {
413 fixed_hdrlen += 8;
414 if (len < fixed_hdrlen) {
415 ND_PRINT("truncated-%s - %u bytes missing!",
416 tok2str(dccp_pkt_type_str, "", dccph_type),
417 len - fixed_hdrlen);
418 return;
419 }
420 ND_PRINT("%s ", tok2str(dccp_pkt_type_str, "", dccph_type));
421 break;
422 }
423 case DCCP_PKT_CLOSEREQ:
424 fixed_hdrlen += 8;
425 if (len < fixed_hdrlen) {
426 ND_PRINT("truncated-%s - %u bytes missing!",
427 tok2str(dccp_pkt_type_str, "", dccph_type),
428 len - fixed_hdrlen);
429 return;
430 }
431 ND_PRINT("%s ", tok2str(dccp_pkt_type_str, "", dccph_type));
432 break;
433 case DCCP_PKT_CLOSE:
434 fixed_hdrlen += 8;
435 if (len < fixed_hdrlen) {
436 ND_PRINT("truncated-%s - %u bytes missing!",
437 tok2str(dccp_pkt_type_str, "", dccph_type),
438 len - fixed_hdrlen);
439 return;
440 }
441 ND_PRINT("%s ", tok2str(dccp_pkt_type_str, "", dccph_type));
442 break;
443 case DCCP_PKT_RESET: {
444 const struct dccp_hdr_reset *dhr =
445 (const struct dccp_hdr_reset *)(bp + fixed_hdrlen);
446 fixed_hdrlen += 12;
447 if (len < fixed_hdrlen) {
448 ND_PRINT("truncated-%s - %u bytes missing!",
449 tok2str(dccp_pkt_type_str, "", dccph_type),
450 len - fixed_hdrlen);
451 return;
452 }
453 ND_TCHECK_SIZE(dhr);
454 ND_PRINT("%s (code=%s) ",
455 tok2str(dccp_pkt_type_str, "", dccph_type),
456 dccp_reset_code(EXTRACT_U_1(dhr->dccph_reset_code)));
457 break;
458 }
459 case DCCP_PKT_SYNC:
460 fixed_hdrlen += 8;
461 if (len < fixed_hdrlen) {
462 ND_PRINT("truncated-%s - %u bytes missing!",
463 tok2str(dccp_pkt_type_str, "", dccph_type),
464 len - fixed_hdrlen);
465 return;
466 }
467 ND_PRINT("%s ", tok2str(dccp_pkt_type_str, "", dccph_type));
468 break;
469 case DCCP_PKT_SYNCACK:
470 fixed_hdrlen += 8;
471 if (len < fixed_hdrlen) {
472 ND_PRINT("truncated-%s - %u bytes missing!",
473 tok2str(dccp_pkt_type_str, "", dccph_type),
474 len - fixed_hdrlen);
475 return;
476 }
477 ND_PRINT("%s ", tok2str(dccp_pkt_type_str, "", dccph_type));
478 break;
479 default:
480 ND_PRINT("%s ", tok2str(dccp_pkt_type_str, "unknown-type-%u", dccph_type));
481 break;
482 }
483
484 if ((DCCPH_TYPE(dh) != DCCP_PKT_DATA) &&
485 (DCCPH_TYPE(dh) != DCCP_PKT_REQUEST))
486 dccp_print_ack_no(ndo, bp);
487
488 if (ndo->ndo_vflag < 2)
489 return;
490
491 ND_PRINT("seq %" PRIu64, dccp_seqno(bp));
492
493 /* process options */
494 if (hlen > fixed_hdrlen){
495 u_int optlen;
496 cp = bp + fixed_hdrlen;
497 ND_PRINT(" <");
498
499 hlen -= fixed_hdrlen;
500 while(1){
501 optlen = dccp_print_option(ndo, cp, hlen);
502 if (!optlen)
503 break;
504 if (hlen <= optlen)
505 break;
506 hlen -= optlen;
507 cp += optlen;
508 ND_PRINT(", ");
509 }
510 ND_PRINT(">");
511 }
512 return;
513 trunc:
514 nd_print_trunc(ndo);
515 return;
516 }
517
518 static const struct tok dccp_option_values[] = {
519 { 0, "nop" },
520 { 1, "mandatory" },
521 { 2, "slowreceiver" },
522 { 32, "change_l" },
523 { 33, "confirm_l" },
524 { 34, "change_r" },
525 { 35, "confirm_r" },
526 { 36, "initcookie" },
527 { 37, "ndp_count" },
528 { 38, "ack_vector0" },
529 { 39, "ack_vector1" },
530 { 40, "data_dropped" },
531 { 41, "timestamp" },
532 { 42, "timestamp_echo" },
533 { 43, "elapsed_time" },
534 { 44, "data_checksum" },
535 { 0, NULL }
536 };
537
538 static u_int
539 dccp_print_option(netdissect_options *ndo, const u_char *option, u_int hlen)
540 {
541 uint8_t optlen, i;
542
543 ND_TCHECK_1(option);
544
545 if (EXTRACT_U_1(option) >= 32) {
546 ND_TCHECK_1(option + 1);
547 optlen = EXTRACT_U_1(option + 1);
548 if (optlen < 2) {
549 if (EXTRACT_U_1(option) >= 128)
550 ND_PRINT("CCID option %u optlen too short", EXTRACT_U_1(option));
551 else
552 ND_PRINT("%s optlen too short",
553 tok2str(dccp_option_values, "Option %u", EXTRACT_U_1(option)));
554 return 0;
555 }
556 } else
557 optlen = 1;
558
559 if (hlen < optlen) {
560 if (EXTRACT_U_1(option) >= 128)
561 ND_PRINT("CCID option %u optlen goes past header length",
562 EXTRACT_U_1(option));
563 else
564 ND_PRINT("%s optlen goes past header length",
565 tok2str(dccp_option_values, "Option %u", EXTRACT_U_1(option)));
566 return 0;
567 }
568 ND_TCHECK_LEN(option, optlen);
569
570 if (EXTRACT_U_1(option) >= 128) {
571 ND_PRINT("CCID option %u", EXTRACT_U_1(option));
572 switch (optlen) {
573 case 4:
574 ND_PRINT(" %u", EXTRACT_BE_U_2(option + 2));
575 break;
576 case 6:
577 ND_PRINT(" %u", EXTRACT_BE_U_4(option + 2));
578 break;
579 default:
580 break;
581 }
582 } else {
583 ND_PRINT("%s", tok2str(dccp_option_values, "Option %u", EXTRACT_U_1(option)));
584 switch (EXTRACT_U_1(option)) {
585 case 32:
586 case 33:
587 case 34:
588 case 35:
589 if (optlen < 3) {
590 ND_PRINT(" optlen too short");
591 return optlen;
592 }
593 if (EXTRACT_U_1(option + 2) < 10){
594 ND_PRINT(" %s", dccp_feature_nums[EXTRACT_U_1(option + 2)]);
595 for (i = 0; i < optlen - 3; i++)
596 ND_PRINT(" %u", EXTRACT_U_1(option + 3 + i));
597 }
598 break;
599 case 36:
600 if (optlen > 2) {
601 ND_PRINT(" 0x");
602 for (i = 0; i < optlen - 2; i++)
603 ND_PRINT("%02x", EXTRACT_U_1(option + 2 + i));
604 }
605 break;
606 case 37:
607 for (i = 0; i < optlen - 2; i++)
608 ND_PRINT(" %u", EXTRACT_U_1(option + 2 + i));
609 break;
610 case 38:
611 if (optlen > 2) {
612 ND_PRINT(" 0x");
613 for (i = 0; i < optlen - 2; i++)
614 ND_PRINT("%02x", EXTRACT_U_1(option + 2 + i));
615 }
616 break;
617 case 39:
618 if (optlen > 2) {
619 ND_PRINT(" 0x");
620 for (i = 0; i < optlen - 2; i++)
621 ND_PRINT("%02x", EXTRACT_U_1(option + 2 + i));
622 }
623 break;
624 case 40:
625 if (optlen > 2) {
626 ND_PRINT(" 0x");
627 for (i = 0; i < optlen - 2; i++)
628 ND_PRINT("%02x", EXTRACT_U_1(option + 2 + i));
629 }
630 break;
631 case 41:
632 /*
633 * 13.1. Timestamp Option
634 *
635 * +--------+--------+--------+--------+--------+--------+
636 * |00101001|00000110| Timestamp Value |
637 * +--------+--------+--------+--------+--------+--------+
638 * Type=41 Length=6
639 */
640 if (optlen == 6)
641 ND_PRINT(" %u", EXTRACT_BE_U_4(option + 2));
642 else
643 ND_PRINT(" [optlen != 6]");
644 break;
645 case 42:
646 /*
647 * 13.3. Timestamp Echo Option
648 *
649 * +--------+--------+--------+--------+--------+--------+
650 * |00101010|00000110| Timestamp Echo |
651 * +--------+--------+--------+--------+--------+--------+
652 * Type=42 Len=6
653 *
654 * +--------+--------+------- ... -------+--------+--------+
655 * |00101010|00001000| Timestamp Echo | Elapsed Time |
656 * +--------+--------+------- ... -------+--------+--------+
657 * Type=42 Len=8 (4 bytes)
658 *
659 * +--------+--------+------- ... -------+------- ... -------+
660 * |00101010|00001010| Timestamp Echo | Elapsed Time |
661 * +--------+--------+------- ... -------+------- ... -------+
662 * Type=42 Len=10 (4 bytes) (4 bytes)
663 */
664 switch (optlen) {
665 case 6:
666 ND_PRINT(" %u", EXTRACT_BE_U_4(option + 2));
667 break;
668 case 8:
669 ND_PRINT(" %u", EXTRACT_BE_U_4(option + 2));
670 ND_PRINT(" (elapsed time %u)", EXTRACT_BE_U_2(option + 6));
671 break;
672 case 10:
673 ND_PRINT(" %u", EXTRACT_BE_U_4(option + 2));
674 ND_PRINT(" (elapsed time %u)", EXTRACT_BE_U_4(option + 6));
675 break;
676 default:
677 ND_PRINT(" [optlen != 6 or 8 or 10]");
678 break;
679 }
680 break;
681 case 43:
682 if (optlen == 6)
683 ND_PRINT(" %u", EXTRACT_BE_U_4(option + 2));
684 else if (optlen == 4)
685 ND_PRINT(" %u", EXTRACT_BE_U_2(option + 2));
686 else
687 ND_PRINT(" [optlen != 4 or 6]");
688 break;
689 case 44:
690 if (optlen > 2) {
691 ND_PRINT(" ");
692 for (i = 0; i < optlen - 2; i++)
693 ND_PRINT("%02x", EXTRACT_U_1(option + 2 + i));
694 }
695 break;
696 }
697 }
698
699 return optlen;
700 trunc:
701 nd_print_trunc(ndo);
702 return 0;
703 }
[mirror] the TCPdump network dissector