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[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 "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
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
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
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
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
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
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
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
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
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 }
[mirror] the TCPdump network dissector