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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 <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 - Connection 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 - Connection 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(netdissect_options *ndo,
195 const struct dccp_hdr* dh, u_int len)
196 {
197 u_int cov;
198
199 if (DCCPH_CSCOV(dh) == 0)
200 return len;
201 cov = (EXTRACT_U_1(dh->dccph_doff) + DCCPH_CSCOV(dh) - 1) * sizeof(uint32_t);
202 return (cov > len)? len : cov;
203 }
204
205 static uint16_t dccp_cksum(netdissect_options *ndo, const struct ip *ip,
206 const struct dccp_hdr *dh, u_int len)
207 {
208 return nextproto4_cksum(ndo, ip, (const uint8_t *)(const void *)dh, len,
209 dccp_csum_coverage(ndo, dh, len), IPPROTO_DCCP);
210 }
211
212 static uint16_t dccp6_cksum(netdissect_options *ndo, const struct ip6_hdr *ip6,
213 const struct dccp_hdr *dh, u_int len)
214 {
215 return nextproto6_cksum(ndo, ip6, (const uint8_t *)(const void *)dh, len,
216 dccp_csum_coverage(ndo, dh, len), IPPROTO_DCCP);
217 }
218
219 static const char *dccp_reset_code(uint8_t code)
220 {
221 if (code >= __DCCP_RESET_CODE_LAST)
222 return "invalid";
223 return dccp_reset_codes[code];
224 }
225
226 static uint64_t
227 dccp_seqno(netdissect_options *ndo, const u_char *bp)
228 {
229 const struct dccp_hdr *dh = (const struct dccp_hdr *)bp;
230 uint64_t seqno;
231
232 if (DCCPH_X(dh) != 0) {
233 const struct dccp_hdr_ext *dhx = (const struct dccp_hdr_ext *)bp;
234 seqno = EXTRACT_BE_U_6(dhx->dccph_seq);
235 } else {
236 seqno = EXTRACT_BE_U_3(dh->dccph_seq);
237 }
238
239 return seqno;
240 }
241
242 static unsigned int
243 dccp_basic_hdr_len(netdissect_options *ndo, const struct dccp_hdr *dh)
244 {
245 return DCCPH_X(dh) ? sizeof(struct dccp_hdr_ext) : sizeof(struct dccp_hdr);
246 }
247
248 static void dccp_print_ack_no(netdissect_options *ndo, const u_char *bp)
249 {
250 const struct dccp_hdr *dh = (const struct dccp_hdr *)bp;
251 const u_char *ackp = bp + dccp_basic_hdr_len(ndo, dh);
252 uint64_t ackno;
253
254 if (DCCPH_X(dh) != 0) {
255 ND_TCHECK_8(ackp);
256 ackno = EXTRACT_BE_U_6(ackp + 2);
257 } else {
258 ND_TCHECK_4(ackp);
259 ackno = EXTRACT_BE_U_3(ackp + 1);
260 }
261
262 ND_PRINT("(ack=%" PRIu64 ") ", ackno);
263 trunc:
264 return;
265 }
266
267 static u_int dccp_print_option(netdissect_options *, const u_char *, u_int);
268
269 /**
270 * dccp_print - show dccp packet
271 * @bp - beginning of dccp packet
272 * @data2 - beginning of enclosing
273 * @len - length of ip packet
274 */
275 void
276 dccp_print(netdissect_options *ndo, const u_char *bp, const u_char *data2,
277 u_int len)
278 {
279 const struct dccp_hdr *dh;
280 const struct ip *ip;
281 const struct ip6_hdr *ip6;
282 const u_char *cp;
283 u_short sport, dport;
284 u_int hlen;
285 u_int fixed_hdrlen;
286 uint8_t dccph_type;
287
288 ndo->ndo_protocol = "dccp";
289 dh = (const struct dccp_hdr *)bp;
290
291 ip = (const struct ip *)data2;
292 if (IP_V(ip) == 6)
293 ip6 = (const struct ip6_hdr *)data2;
294 else
295 ip6 = NULL;
296
297 /* make sure we have enough data to look at the X bit */
298 cp = (const u_char *)(dh + 1);
299 if (cp > ndo->ndo_snapend)
300 goto trunc;
301 if (len < sizeof(struct dccp_hdr)) {
302 ND_PRINT("truncated-dccp - %u bytes missing!",
303 (u_int)sizeof(struct dccp_hdr) - len);
304 return;
305 }
306
307 /* get the length of the generic header */
308 fixed_hdrlen = dccp_basic_hdr_len(ndo, dh);
309 if (len < fixed_hdrlen) {
310 ND_PRINT("truncated-dccp - %u bytes missing!",
311 fixed_hdrlen - len);
312 return;
313 }
314 ND_TCHECK_LEN(dh, fixed_hdrlen);
315
316 sport = EXTRACT_BE_U_2(dh->dccph_sport);
317 dport = EXTRACT_BE_U_2(dh->dccph_dport);
318 hlen = EXTRACT_U_1(dh->dccph_doff) * 4;
319
320 if (ip6) {
321 ND_PRINT("%s.%u > %s.%u: ",
322 ip6addr_string(ndo, ip6->ip6_src), sport,
323 ip6addr_string(ndo, ip6->ip6_dst), dport);
324 } else {
325 ND_PRINT("%s.%u > %s.%u: ",
326 ipaddr_string(ndo, ip->ip_src), sport,
327 ipaddr_string(ndo, ip->ip_dst), dport);
328 }
329
330 ND_PRINT("DCCP");
331
332 if (ndo->ndo_qflag) {
333 ND_PRINT(" %u", len - hlen);
334 if (hlen > len) {
335 ND_PRINT(" [bad hdr length %u - too long, > %u]",
336 hlen, len);
337 }
338 return;
339 }
340
341 /* other variables in generic header */
342 if (ndo->ndo_vflag) {
343 ND_PRINT(" (CCVal %u, CsCov %u, ", DCCPH_CCVAL(dh), DCCPH_CSCOV(dh));
344 }
345
346 /* checksum calculation */
347 if (ndo->ndo_vflag && ND_TTEST_LEN(bp, len)) {
348 uint16_t sum = 0, dccp_sum;
349
350 dccp_sum = EXTRACT_BE_U_2(dh->dccph_checksum);
351 ND_PRINT("cksum 0x%04x ", dccp_sum);
352 if (IP_V(ip) == 4)
353 sum = dccp_cksum(ndo, ip, dh, len);
354 else if (IP_V(ip) == 6)
355 sum = dccp6_cksum(ndo, ip6, dh, len);
356 if (sum != 0)
357 ND_PRINT("(incorrect -> 0x%04x)",in_cksum_shouldbe(dccp_sum, sum));
358 else
359 ND_PRINT("(correct)");
360 }
361
362 if (ndo->ndo_vflag)
363 ND_PRINT(")");
364 ND_PRINT(" ");
365
366 dccph_type = DCCPH_TYPE(dh);
367 switch (dccph_type) {
368 case DCCP_PKT_REQUEST: {
369 const struct dccp_hdr_request *dhr =
370 (const struct dccp_hdr_request *)(bp + fixed_hdrlen);
371 fixed_hdrlen += 4;
372 if (len < fixed_hdrlen) {
373 ND_PRINT("truncated-%s - %u bytes missing!",
374 tok2str(dccp_pkt_type_str, "", dccph_type),
375 fixed_hdrlen - len);
376 return;
377 }
378 ND_TCHECK_SIZE(dhr);
379 ND_PRINT("%s (service=%u) ",
380 tok2str(dccp_pkt_type_str, "", dccph_type),
381 EXTRACT_BE_U_4(dhr->dccph_req_service));
382 break;
383 }
384 case DCCP_PKT_RESPONSE: {
385 const struct dccp_hdr_response *dhr =
386 (const struct dccp_hdr_response *)(bp + fixed_hdrlen);
387 fixed_hdrlen += 12;
388 if (len < fixed_hdrlen) {
389 ND_PRINT("truncated-%s - %u bytes missing!",
390 tok2str(dccp_pkt_type_str, "", dccph_type),
391 fixed_hdrlen - len);
392 return;
393 }
394 ND_TCHECK_SIZE(dhr);
395 ND_PRINT("%s (service=%u) ",
396 tok2str(dccp_pkt_type_str, "", dccph_type),
397 EXTRACT_BE_U_4(dhr->dccph_resp_service));
398 break;
399 }
400 case DCCP_PKT_DATA:
401 ND_PRINT("%s ", tok2str(dccp_pkt_type_str, "", dccph_type));
402 break;
403 case DCCP_PKT_ACK: {
404 fixed_hdrlen += 8;
405 if (len < fixed_hdrlen) {
406 ND_PRINT("truncated-%s - %u bytes missing!",
407 tok2str(dccp_pkt_type_str, "", dccph_type),
408 fixed_hdrlen - len);
409 return;
410 }
411 ND_PRINT("%s ", tok2str(dccp_pkt_type_str, "", dccph_type));
412 break;
413 }
414 case DCCP_PKT_DATAACK: {
415 fixed_hdrlen += 8;
416 if (len < fixed_hdrlen) {
417 ND_PRINT("truncated-%s - %u bytes missing!",
418 tok2str(dccp_pkt_type_str, "", dccph_type),
419 fixed_hdrlen - len);
420 return;
421 }
422 ND_PRINT("%s ", tok2str(dccp_pkt_type_str, "", dccph_type));
423 break;
424 }
425 case DCCP_PKT_CLOSEREQ:
426 fixed_hdrlen += 8;
427 if (len < fixed_hdrlen) {
428 ND_PRINT("truncated-%s - %u bytes missing!",
429 tok2str(dccp_pkt_type_str, "", dccph_type),
430 fixed_hdrlen - len);
431 return;
432 }
433 ND_PRINT("%s ", tok2str(dccp_pkt_type_str, "", dccph_type));
434 break;
435 case DCCP_PKT_CLOSE:
436 fixed_hdrlen += 8;
437 if (len < fixed_hdrlen) {
438 ND_PRINT("truncated-%s - %u bytes missing!",
439 tok2str(dccp_pkt_type_str, "", dccph_type),
440 fixed_hdrlen - len);
441 return;
442 }
443 ND_PRINT("%s ", tok2str(dccp_pkt_type_str, "", dccph_type));
444 break;
445 case DCCP_PKT_RESET: {
446 const struct dccp_hdr_reset *dhr =
447 (const struct dccp_hdr_reset *)(bp + fixed_hdrlen);
448 fixed_hdrlen += 12;
449 if (len < fixed_hdrlen) {
450 ND_PRINT("truncated-%s - %u bytes missing!",
451 tok2str(dccp_pkt_type_str, "", dccph_type),
452 fixed_hdrlen - len);
453 return;
454 }
455 ND_TCHECK_SIZE(dhr);
456 ND_PRINT("%s (code=%s) ",
457 tok2str(dccp_pkt_type_str, "", dccph_type),
458 dccp_reset_code(EXTRACT_U_1(dhr->dccph_reset_code)));
459 break;
460 }
461 case DCCP_PKT_SYNC:
462 fixed_hdrlen += 8;
463 if (len < fixed_hdrlen) {
464 ND_PRINT("truncated-%s - %u bytes missing!",
465 tok2str(dccp_pkt_type_str, "", dccph_type),
466 fixed_hdrlen - len);
467 return;
468 }
469 ND_PRINT("%s ", tok2str(dccp_pkt_type_str, "", dccph_type));
470 break;
471 case DCCP_PKT_SYNCACK:
472 fixed_hdrlen += 8;
473 if (len < fixed_hdrlen) {
474 ND_PRINT("truncated-%s - %u bytes missing!",
475 tok2str(dccp_pkt_type_str, "", dccph_type),
476 fixed_hdrlen - len);
477 return;
478 }
479 ND_PRINT("%s ", tok2str(dccp_pkt_type_str, "", dccph_type));
480 break;
481 default:
482 ND_PRINT("%s ", tok2str(dccp_pkt_type_str, "unknown-type-%u", dccph_type));
483 break;
484 }
485
486 if ((DCCPH_TYPE(dh) != DCCP_PKT_DATA) &&
487 (DCCPH_TYPE(dh) != DCCP_PKT_REQUEST))
488 dccp_print_ack_no(ndo, bp);
489
490 if (ndo->ndo_vflag < 2)
491 return;
492
493 ND_PRINT("seq %" PRIu64, dccp_seqno(ndo, bp));
494
495 /* process options */
496 if (hlen > fixed_hdrlen){
497 u_int optlen;
498 cp = bp + fixed_hdrlen;
499 ND_PRINT(" <");
500
501 hlen -= fixed_hdrlen;
502 while(1){
503 optlen = dccp_print_option(ndo, cp, hlen);
504 if (!optlen)
505 break;
506 if (hlen <= optlen)
507 break;
508 hlen -= optlen;
509 cp += optlen;
510 ND_PRINT(", ");
511 }
512 ND_PRINT(">");
513 }
514 return;
515 trunc:
516 nd_print_trunc(ndo);
517 return;
518 }
519
520 static const struct tok dccp_option_values[] = {
521 { 0, "nop" },
522 { 1, "mandatory" },
523 { 2, "slowreceiver" },
524 { 32, "change_l" },
525 { 33, "confirm_l" },
526 { 34, "change_r" },
527 { 35, "confirm_r" },
528 { 36, "initcookie" },
529 { 37, "ndp_count" },
530 { 38, "ack_vector0" },
531 { 39, "ack_vector1" },
532 { 40, "data_dropped" },
533 { 41, "timestamp" },
534 { 42, "timestamp_echo" },
535 { 43, "elapsed_time" },
536 { 44, "data_checksum" },
537 { 0, NULL }
538 };
539
540 static u_int
541 dccp_print_option(netdissect_options *ndo, const u_char *option, u_int hlen)
542 {
543 uint8_t optlen, i;
544
545 ND_TCHECK_1(option);
546
547 if (EXTRACT_U_1(option) >= 32) {
548 ND_TCHECK_1(option + 1);
549 optlen = EXTRACT_U_1(option + 1);
550 if (optlen < 2) {
551 if (EXTRACT_U_1(option) >= 128)
552 ND_PRINT("CCID option %u optlen too short", EXTRACT_U_1(option));
553 else
554 ND_PRINT("%s optlen too short",
555 tok2str(dccp_option_values, "Option %u", EXTRACT_U_1(option)));
556 return 0;
557 }
558 } else
559 optlen = 1;
560
561 if (hlen < optlen) {
562 if (EXTRACT_U_1(option) >= 128)
563 ND_PRINT("CCID option %u optlen goes past header length",
564 EXTRACT_U_1(option));
565 else
566 ND_PRINT("%s optlen goes past header length",
567 tok2str(dccp_option_values, "Option %u", EXTRACT_U_1(option)));
568 return 0;
569 }
570 ND_TCHECK_LEN(option, optlen);
571
572 if (EXTRACT_U_1(option) >= 128) {
573 ND_PRINT("CCID option %u", EXTRACT_U_1(option));
574 switch (optlen) {
575 case 4:
576 ND_PRINT(" %u", EXTRACT_BE_U_2(option + 2));
577 break;
578 case 6:
579 ND_PRINT(" %u", EXTRACT_BE_U_4(option + 2));
580 break;
581 default:
582 break;
583 }
584 } else {
585 ND_PRINT("%s", tok2str(dccp_option_values, "Option %u", EXTRACT_U_1(option)));
586 switch (EXTRACT_U_1(option)) {
587 case 32:
588 case 33:
589 case 34:
590 case 35:
591 if (optlen < 3) {
592 ND_PRINT(" optlen too short");
593 return optlen;
594 }
595 if (EXTRACT_U_1(option + 2) < 10){
596 ND_PRINT(" %s", dccp_feature_nums[EXTRACT_U_1(option + 2)]);
597 for (i = 0; i < optlen - 3; i++)
598 ND_PRINT(" %u", EXTRACT_U_1(option + 3 + i));
599 }
600 break;
601 case 36:
602 if (optlen > 2) {
603 ND_PRINT(" 0x");
604 for (i = 0; i < optlen - 2; i++)
605 ND_PRINT("%02x", EXTRACT_U_1(option + 2 + i));
606 }
607 break;
608 case 37:
609 for (i = 0; i < optlen - 2; i++)
610 ND_PRINT(" %u", EXTRACT_U_1(option + 2 + i));
611 break;
612 case 38:
613 if (optlen > 2) {
614 ND_PRINT(" 0x");
615 for (i = 0; i < optlen - 2; i++)
616 ND_PRINT("%02x", EXTRACT_U_1(option + 2 + i));
617 }
618 break;
619 case 39:
620 if (optlen > 2) {
621 ND_PRINT(" 0x");
622 for (i = 0; i < optlen - 2; i++)
623 ND_PRINT("%02x", EXTRACT_U_1(option + 2 + i));
624 }
625 break;
626 case 40:
627 if (optlen > 2) {
628 ND_PRINT(" 0x");
629 for (i = 0; i < optlen - 2; i++)
630 ND_PRINT("%02x", EXTRACT_U_1(option + 2 + i));
631 }
632 break;
633 case 41:
634 /*
635 * 13.1. Timestamp Option
636 *
637 * +--------+--------+--------+--------+--------+--------+
638 * |00101001|00000110| Timestamp Value |
639 * +--------+--------+--------+--------+--------+--------+
640 * Type=41 Length=6
641 */
642 if (optlen == 6)
643 ND_PRINT(" %u", EXTRACT_BE_U_4(option + 2));
644 else
645 ND_PRINT(" [optlen != 6]");
646 break;
647 case 42:
648 /*
649 * 13.3. Timestamp Echo Option
650 *
651 * +--------+--------+--------+--------+--------+--------+
652 * |00101010|00000110| Timestamp Echo |
653 * +--------+--------+--------+--------+--------+--------+
654 * Type=42 Len=6
655 *
656 * +--------+--------+------- ... -------+--------+--------+
657 * |00101010|00001000| Timestamp Echo | Elapsed Time |
658 * +--------+--------+------- ... -------+--------+--------+
659 * Type=42 Len=8 (4 bytes)
660 *
661 * +--------+--------+------- ... -------+------- ... -------+
662 * |00101010|00001010| Timestamp Echo | Elapsed Time |
663 * +--------+--------+------- ... -------+------- ... -------+
664 * Type=42 Len=10 (4 bytes) (4 bytes)
665 */
666 switch (optlen) {
667 case 6:
668 ND_PRINT(" %u", EXTRACT_BE_U_4(option + 2));
669 break;
670 case 8:
671 ND_PRINT(" %u", EXTRACT_BE_U_4(option + 2));
672 ND_PRINT(" (elapsed time %u)", EXTRACT_BE_U_2(option + 6));
673 break;
674 case 10:
675 ND_PRINT(" %u", EXTRACT_BE_U_4(option + 2));
676 ND_PRINT(" (elapsed time %u)", EXTRACT_BE_U_4(option + 6));
677 break;
678 default:
679 ND_PRINT(" [optlen != 6 or 8 or 10]");
680 break;
681 }
682 break;
683 case 43:
684 if (optlen == 6)
685 ND_PRINT(" %u", EXTRACT_BE_U_4(option + 2));
686 else if (optlen == 4)
687 ND_PRINT(" %u", EXTRACT_BE_U_2(option + 2));
688 else
689 ND_PRINT(" [optlen != 4 or 6]");
690 break;
691 case 44:
692 if (optlen > 2) {
693 ND_PRINT(" ");
694 for (i = 0; i < optlen - 2; i++)
695 ND_PRINT("%02x", EXTRACT_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