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Remove useless 'return' at end of void functions (style)
[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) ((GET_U_1((dh)->dccph_ccval_cscov) >> 4) & 0xF)
82 #define DCCPH_CSCOV(dh) (GET_U_1((dh)->dccph_ccval_cscov) & 0xF)
83
84 #define DCCPH_X(dh) (GET_U_1((dh)->dccph_xtr) & 1)
85 #define DCCPH_TYPE(dh) ((GET_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 = (GET_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 = GET_BE_U_6(dhx->dccph_seq);
235 } else {
236 seqno = GET_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 ackno = GET_BE_U_6(ackp + 2);
256 } else {
257 ackno = GET_BE_U_3(ackp + 1);
258 }
259
260 ND_PRINT("(ack=%" PRIu64 ") ", ackno);
261 }
262
263 static u_int dccp_print_option(netdissect_options *, const u_char *, u_int);
264
265 /**
266 * dccp_print - show dccp packet
267 * @bp - beginning of dccp packet
268 * @data2 - beginning of enclosing
269 * @len - length of ip packet
270 */
271 void
272 dccp_print(netdissect_options *ndo, const u_char *bp, const u_char *data2,
273 u_int len)
274 {
275 const struct dccp_hdr *dh;
276 const struct ip *ip;
277 const struct ip6_hdr *ip6;
278 const u_char *cp;
279 u_short sport, dport;
280 u_int hlen;
281 u_int fixed_hdrlen;
282 uint8_t dccph_type;
283
284 ndo->ndo_protocol = "dccp";
285 dh = (const struct dccp_hdr *)bp;
286
287 ip = (const struct ip *)data2;
288 if (IP_V(ip) == 6)
289 ip6 = (const struct ip6_hdr *)data2;
290 else
291 ip6 = NULL;
292
293 /* make sure we have enough data to look at the X bit */
294 cp = (const u_char *)(dh + 1);
295 if (cp > ndo->ndo_snapend)
296 goto trunc;
297 if (len < sizeof(struct dccp_hdr)) {
298 ND_PRINT("truncated-dccp - %u bytes missing!",
299 (u_int)sizeof(struct dccp_hdr) - len);
300 return;
301 }
302
303 /* get the length of the generic header */
304 fixed_hdrlen = dccp_basic_hdr_len(ndo, dh);
305 if (len < fixed_hdrlen) {
306 ND_PRINT("truncated-dccp - %u bytes missing!",
307 fixed_hdrlen - len);
308 return;
309 }
310 ND_TCHECK_LEN(dh, fixed_hdrlen);
311
312 sport = GET_BE_U_2(dh->dccph_sport);
313 dport = GET_BE_U_2(dh->dccph_dport);
314 hlen = GET_U_1(dh->dccph_doff) * 4;
315
316 if (ip6) {
317 ND_PRINT("%s.%u > %s.%u: ",
318 GET_IP6ADDR_STRING(ip6->ip6_src), sport,
319 GET_IP6ADDR_STRING(ip6->ip6_dst), dport);
320 } else {
321 ND_PRINT("%s.%u > %s.%u: ",
322 GET_IPADDR_STRING(ip->ip_src), sport,
323 GET_IPADDR_STRING(ip->ip_dst), dport);
324 }
325
326 nd_print_protocol_caps(ndo);
327
328 if (ndo->ndo_qflag) {
329 ND_PRINT(" %u", len - hlen);
330 if (hlen > len) {
331 ND_PRINT(" [bad hdr length %u - too long, > %u]",
332 hlen, len);
333 }
334 return;
335 }
336
337 /* other variables in generic header */
338 if (ndo->ndo_vflag) {
339 ND_PRINT(" (CCVal %u, CsCov %u, ", DCCPH_CCVAL(dh), DCCPH_CSCOV(dh));
340 }
341
342 /* checksum calculation */
343 if (ndo->ndo_vflag && ND_TTEST_LEN(bp, len)) {
344 uint16_t sum = 0, dccp_sum;
345
346 dccp_sum = GET_BE_U_2(dh->dccph_checksum);
347 ND_PRINT("cksum 0x%04x ", dccp_sum);
348 if (IP_V(ip) == 4)
349 sum = dccp_cksum(ndo, ip, dh, len);
350 else if (IP_V(ip) == 6)
351 sum = dccp6_cksum(ndo, ip6, dh, len);
352 if (sum != 0)
353 ND_PRINT("(incorrect -> 0x%04x)",in_cksum_shouldbe(dccp_sum, sum));
354 else
355 ND_PRINT("(correct)");
356 }
357
358 if (ndo->ndo_vflag)
359 ND_PRINT(")");
360 ND_PRINT(" ");
361
362 dccph_type = DCCPH_TYPE(dh);
363 switch (dccph_type) {
364 case DCCP_PKT_REQUEST: {
365 const struct dccp_hdr_request *dhr =
366 (const struct dccp_hdr_request *)(bp + fixed_hdrlen);
367 fixed_hdrlen += 4;
368 if (len < fixed_hdrlen) {
369 ND_PRINT("truncated-%s - %u bytes missing!",
370 tok2str(dccp_pkt_type_str, "", dccph_type),
371 fixed_hdrlen - len);
372 return;
373 }
374 ND_TCHECK_SIZE(dhr);
375 ND_PRINT("%s (service=%u) ",
376 tok2str(dccp_pkt_type_str, "", dccph_type),
377 GET_BE_U_4(dhr->dccph_req_service));
378 break;
379 }
380 case DCCP_PKT_RESPONSE: {
381 const struct dccp_hdr_response *dhr =
382 (const struct dccp_hdr_response *)(bp + fixed_hdrlen);
383 fixed_hdrlen += 12;
384 if (len < fixed_hdrlen) {
385 ND_PRINT("truncated-%s - %u bytes missing!",
386 tok2str(dccp_pkt_type_str, "", dccph_type),
387 fixed_hdrlen - len);
388 return;
389 }
390 ND_TCHECK_SIZE(dhr);
391 ND_PRINT("%s (service=%u) ",
392 tok2str(dccp_pkt_type_str, "", dccph_type),
393 GET_BE_U_4(dhr->dccph_resp_service));
394 break;
395 }
396 case DCCP_PKT_DATA:
397 ND_PRINT("%s ", tok2str(dccp_pkt_type_str, "", dccph_type));
398 break;
399 case DCCP_PKT_ACK: {
400 fixed_hdrlen += 8;
401 if (len < fixed_hdrlen) {
402 ND_PRINT("truncated-%s - %u bytes missing!",
403 tok2str(dccp_pkt_type_str, "", dccph_type),
404 fixed_hdrlen - len);
405 return;
406 }
407 ND_PRINT("%s ", tok2str(dccp_pkt_type_str, "", dccph_type));
408 break;
409 }
410 case DCCP_PKT_DATAACK: {
411 fixed_hdrlen += 8;
412 if (len < fixed_hdrlen) {
413 ND_PRINT("truncated-%s - %u bytes missing!",
414 tok2str(dccp_pkt_type_str, "", dccph_type),
415 fixed_hdrlen - len);
416 return;
417 }
418 ND_PRINT("%s ", tok2str(dccp_pkt_type_str, "", dccph_type));
419 break;
420 }
421 case DCCP_PKT_CLOSEREQ:
422 fixed_hdrlen += 8;
423 if (len < fixed_hdrlen) {
424 ND_PRINT("truncated-%s - %u bytes missing!",
425 tok2str(dccp_pkt_type_str, "", dccph_type),
426 fixed_hdrlen - len);
427 return;
428 }
429 ND_PRINT("%s ", tok2str(dccp_pkt_type_str, "", dccph_type));
430 break;
431 case DCCP_PKT_CLOSE:
432 fixed_hdrlen += 8;
433 if (len < fixed_hdrlen) {
434 ND_PRINT("truncated-%s - %u bytes missing!",
435 tok2str(dccp_pkt_type_str, "", dccph_type),
436 fixed_hdrlen - len);
437 return;
438 }
439 ND_PRINT("%s ", tok2str(dccp_pkt_type_str, "", dccph_type));
440 break;
441 case DCCP_PKT_RESET: {
442 const struct dccp_hdr_reset *dhr =
443 (const struct dccp_hdr_reset *)(bp + fixed_hdrlen);
444 fixed_hdrlen += 12;
445 if (len < fixed_hdrlen) {
446 ND_PRINT("truncated-%s - %u bytes missing!",
447 tok2str(dccp_pkt_type_str, "", dccph_type),
448 fixed_hdrlen - len);
449 return;
450 }
451 ND_TCHECK_SIZE(dhr);
452 ND_PRINT("%s (code=%s) ",
453 tok2str(dccp_pkt_type_str, "", dccph_type),
454 dccp_reset_code(GET_U_1(dhr->dccph_reset_code)));
455 break;
456 }
457 case DCCP_PKT_SYNC:
458 fixed_hdrlen += 8;
459 if (len < fixed_hdrlen) {
460 ND_PRINT("truncated-%s - %u bytes missing!",
461 tok2str(dccp_pkt_type_str, "", dccph_type),
462 fixed_hdrlen - len);
463 return;
464 }
465 ND_PRINT("%s ", tok2str(dccp_pkt_type_str, "", dccph_type));
466 break;
467 case DCCP_PKT_SYNCACK:
468 fixed_hdrlen += 8;
469 if (len < fixed_hdrlen) {
470 ND_PRINT("truncated-%s - %u bytes missing!",
471 tok2str(dccp_pkt_type_str, "", dccph_type),
472 fixed_hdrlen - len);
473 return;
474 }
475 ND_PRINT("%s ", tok2str(dccp_pkt_type_str, "", dccph_type));
476 break;
477 default:
478 ND_PRINT("%s ", tok2str(dccp_pkt_type_str, "unknown-type-%u", dccph_type));
479 break;
480 }
481
482 if ((DCCPH_TYPE(dh) != DCCP_PKT_DATA) &&
483 (DCCPH_TYPE(dh) != DCCP_PKT_REQUEST))
484 dccp_print_ack_no(ndo, bp);
485
486 if (ndo->ndo_vflag < 2)
487 return;
488
489 ND_PRINT("seq %" PRIu64, dccp_seqno(ndo, bp));
490
491 /* process options */
492 if (hlen > fixed_hdrlen){
493 u_int optlen;
494 cp = bp + fixed_hdrlen;
495 ND_PRINT(" <");
496
497 hlen -= fixed_hdrlen;
498 while(1){
499 optlen = dccp_print_option(ndo, cp, hlen);
500 if (!optlen)
501 break;
502 if (hlen <= optlen)
503 break;
504 hlen -= optlen;
505 cp += optlen;
506 ND_PRINT(", ");
507 }
508 ND_PRINT(">");
509 }
510 return;
511 trunc:
512 nd_print_trunc(ndo);
513 }
514
515 static const struct tok dccp_option_values[] = {
516 { 0, "nop" },
517 { 1, "mandatory" },
518 { 2, "slowreceiver" },
519 { 32, "change_l" },
520 { 33, "confirm_l" },
521 { 34, "change_r" },
522 { 35, "confirm_r" },
523 { 36, "initcookie" },
524 { 37, "ndp_count" },
525 { 38, "ack_vector0" },
526 { 39, "ack_vector1" },
527 { 40, "data_dropped" },
528 { 41, "timestamp" },
529 { 42, "timestamp_echo" },
530 { 43, "elapsed_time" },
531 { 44, "data_checksum" },
532 { 0, NULL }
533 };
534
535 static u_int
536 dccp_print_option(netdissect_options *ndo, const u_char *option, u_int hlen)
537 {
538 uint8_t optlen, i;
539
540 if (GET_U_1(option) >= 32) {
541 optlen = GET_U_1(option + 1);
542 if (optlen < 2) {
543 if (GET_U_1(option) >= 128)
544 ND_PRINT("CCID option %u optlen too short",
545 GET_U_1(option));
546 else
547 ND_PRINT("%s optlen too short",
548 tok2str(dccp_option_values, "Option %u", GET_U_1(option)));
549 return 0;
550 }
551 } else
552 optlen = 1;
553
554 if (hlen < optlen) {
555 if (GET_U_1(option) >= 128)
556 ND_PRINT("CCID option %u optlen goes past header length",
557 GET_U_1(option));
558 else
559 ND_PRINT("%s optlen goes past header length",
560 tok2str(dccp_option_values, "Option %u", GET_U_1(option)));
561 return 0;
562 }
563 ND_TCHECK_LEN(option, optlen);
564
565 if (GET_U_1(option) >= 128) {
566 ND_PRINT("CCID option %u", GET_U_1(option));
567 switch (optlen) {
568 case 4:
569 ND_PRINT(" %u", GET_BE_U_2(option + 2));
570 break;
571 case 6:
572 ND_PRINT(" %u", GET_BE_U_4(option + 2));
573 break;
574 default:
575 break;
576 }
577 } else {
578 ND_PRINT("%s",
579 tok2str(dccp_option_values, "Option %u", GET_U_1(option)));
580 switch (GET_U_1(option)) {
581 case 32:
582 case 33:
583 case 34:
584 case 35:
585 if (optlen < 3) {
586 ND_PRINT(" optlen too short");
587 return optlen;
588 }
589 if (GET_U_1(option + 2) < 10){
590 ND_PRINT(" %s",
591 dccp_feature_nums[GET_U_1(option + 2)]);
592 for (i = 0; i < optlen - 3; i++)
593 ND_PRINT(" %u",
594 GET_U_1(option + 3 + i));
595 }
596 break;
597 case 36:
598 if (optlen > 2) {
599 ND_PRINT(" 0x");
600 for (i = 0; i < optlen - 2; i++)
601 ND_PRINT("%02x",
602 GET_U_1(option + 2 + i));
603 }
604 break;
605 case 37:
606 for (i = 0; i < optlen - 2; i++)
607 ND_PRINT(" %u", GET_U_1(option + 2 + i));
608 break;
609 case 38:
610 if (optlen > 2) {
611 ND_PRINT(" 0x");
612 for (i = 0; i < optlen - 2; i++)
613 ND_PRINT("%02x",
614 GET_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",
622 GET_U_1(option + 2 + i));
623 }
624 break;
625 case 40:
626 if (optlen > 2) {
627 ND_PRINT(" 0x");
628 for (i = 0; i < optlen - 2; i++)
629 ND_PRINT("%02x",
630 GET_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", GET_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", GET_BE_U_4(option + 2));
669 break;
670 case 8:
671 ND_PRINT(" %u", GET_BE_U_4(option + 2));
672 ND_PRINT(" (elapsed time %u)",
673 GET_BE_U_2(option + 6));
674 break;
675 case 10:
676 ND_PRINT(" %u", GET_BE_U_4(option + 2));
677 ND_PRINT(" (elapsed time %u)",
678 GET_BE_U_4(option + 6));
679 break;
680 default:
681 ND_PRINT(" [optlen != 6 or 8 or 10]");
682 break;
683 }
684 break;
685 case 43:
686 if (optlen == 6)
687 ND_PRINT(" %u", GET_BE_U_4(option + 2));
688 else if (optlen == 4)
689 ND_PRINT(" %u", GET_BE_U_2(option + 2));
690 else
691 ND_PRINT(" [optlen != 4 or 6]");
692 break;
693 case 44:
694 if (optlen > 2) {
695 ND_PRINT(" ");
696 for (i = 0; i < optlen - 2; i++)
697 ND_PRINT("%02x",
698 GET_U_1(option + 2 + i));
699 }
700 break;
701 }
702 }
703
704 return optlen;
705 trunc:
706 nd_print_trunc(ndo);
707 return 0;
708 }
[mirror] the TCPdump network dissector