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[tcpdump] / print-ntp.c
1 /*
2 * Copyright (c) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that: (1) source code distributions
7 * retain the above copyright notice and this paragraph in its entirety, (2)
8 * distributions including binary code include the above copyright notice and
9 * this paragraph in its entirety in the documentation or other materials
10 * provided with the distribution, and (3) all advertising materials mentioning
11 * features or use of this software display the following acknowledgement:
12 * ``This product includes software developed by the University of California,
13 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
14 * the University nor the names of its contributors may be used to endorse
15 * or promote products derived from this software without specific prior
16 * written permission.
17 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
18 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
19 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
20 *
21 * By Jeffrey Mogul/DECWRL
22 * loosely based on print-bootp.c
23 */
24
25 /* \summary: Network Time Protocol (NTP) printer */
26
27 /*
28 * specification:
29 *
30 * RFC 1119 - NTPv2
31 * RFC 1305 - NTPv3
32 * RFC 5905 - NTPv4
33 */
34
35 #ifdef HAVE_CONFIG_H
36 #include <config.h>
37 #endif
38
39 #include "netdissect-stdinc.h"
40
41 #ifdef HAVE_STRFTIME
42 #include <time.h>
43 #endif
44
45 #include "netdissect.h"
46 #include "addrtoname.h"
47 #include "extract.h"
48
49 static const char tstr[] = " [|ntp]";
50
51 /*
52 * Based on ntp.h from the U of MD implementation
53 * This file is based on Version 2 of the NTP spec (RFC1119).
54 */
55
56 /*
57 * Definitions for the masses
58 */
59 #define JAN_1970 INT64_T_CONSTANT(2208988800) /* 1970 - 1900 in seconds */
60
61 /*
62 * Structure definitions for NTP fixed point values
63 *
64 * 0 1 2 3
65 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
66 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
67 * | Integer Part |
68 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
69 * | Fraction Part |
70 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
71 *
72 * 0 1 2 3
73 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
74 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
75 * | Integer Part | Fraction Part |
76 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
77 */
78 struct l_fixedpt {
79 nd_uint32_t int_part;
80 nd_uint32_t fraction;
81 };
82
83 struct s_fixedpt {
84 nd_uint16_t int_part;
85 nd_uint16_t fraction;
86 };
87
88 /* rfc2030
89 * 1 2 3
90 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
91 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
92 * |LI | VN |Mode | Stratum | Poll | Precision |
93 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
94 * | Root Delay |
95 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
96 * | Root Dispersion |
97 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
98 * | Reference Identifier |
99 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
100 * | |
101 * | Reference Timestamp (64) |
102 * | |
103 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
104 * | |
105 * | Originate Timestamp (64) |
106 * | |
107 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
108 * | |
109 * | Receive Timestamp (64) |
110 * | |
111 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
112 * | |
113 * | Transmit Timestamp (64) |
114 * | |
115 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
116 * | Key Identifier (optional) (32) |
117 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
118 * | |
119 * | |
120 * | Message Digest (optional) (128) |
121 * | |
122 * | |
123 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
124 */
125
126 /* Length of the NTP data message with the mandatory fields ("the header")
127 * and without any optional fields (extension, Key Identifier,
128 * Message Digest).
129 */
130 #define NTP_TIMEMSG_MINLEN 48U
131
132 struct ntp_time_data {
133 nd_uint8_t status; /* status of local clock and leap info */
134 nd_uint8_t stratum; /* Stratum level */
135 nd_int8_t ppoll; /* poll value */
136 nd_int8_t precision;
137 struct s_fixedpt root_delay;
138 struct s_fixedpt root_dispersion;
139 nd_uint32_t refid;
140 struct l_fixedpt ref_timestamp;
141 struct l_fixedpt org_timestamp;
142 struct l_fixedpt rec_timestamp;
143 struct l_fixedpt xmt_timestamp;
144 nd_uint32_t key_id;
145 nd_uint8_t message_digest[20];
146 };
147 /*
148 * Leap Second Codes (high order two bits)
149 */
150 #define NO_WARNING 0x00 /* no warning */
151 #define PLUS_SEC 0x40 /* add a second (61 seconds) */
152 #define MINUS_SEC 0x80 /* minus a second (59 seconds) */
153 #define ALARM 0xc0 /* alarm condition (clock unsynchronized) */
154
155 /*
156 * Clock Status Bits that Encode Version
157 */
158 #define NTPVERSION_1 0x08
159 #define VERSIONMASK 0x38
160 #define VERSIONSHIFT 3
161 #define LEAPMASK 0xc0
162 #define LEAPSHIFT 6
163 #ifdef MODEMASK
164 #undef MODEMASK /* Solaris sucks */
165 #endif
166 #define MODEMASK 0x07
167 #define MODESHIFT 0
168
169 /*
170 * Code values
171 */
172 #define MODE_UNSPEC 0 /* unspecified */
173 #define MODE_SYM_ACT 1 /* symmetric active */
174 #define MODE_SYM_PAS 2 /* symmetric passive */
175 #define MODE_CLIENT 3 /* client */
176 #define MODE_SERVER 4 /* server */
177 #define MODE_BROADCAST 5 /* broadcast */
178 #define MODE_CONTROL 6 /* control message */
179 #define MODE_RES2 7 /* reserved */
180
181 /*
182 * Stratum Definitions
183 */
184 #define UNSPECIFIED 0
185 #define PRIM_REF 1 /* radio clock */
186 #define INFO_QUERY 62 /* **** THIS implementation dependent **** */
187 #define INFO_REPLY 63 /* **** THIS implementation dependent **** */
188
189 static void p_sfix(netdissect_options *ndo, const struct s_fixedpt *);
190 static void p_ntp_time(netdissect_options *, const struct l_fixedpt *);
191 static void p_ntp_delta(netdissect_options *, const struct l_fixedpt *, const struct l_fixedpt *);
192 static void p_poll(netdissect_options *, const int);
193
194 static const struct tok ntp_mode_values[] = {
195 { MODE_UNSPEC, "unspecified" },
196 { MODE_SYM_ACT, "symmetric active" },
197 { MODE_SYM_PAS, "symmetric passive" },
198 { MODE_CLIENT, "Client" },
199 { MODE_SERVER, "Server" },
200 { MODE_BROADCAST, "Broadcast" },
201 { MODE_CONTROL, "Control Message" },
202 { MODE_RES2, "Reserved" },
203 { 0, NULL }
204 };
205
206 static const struct tok ntp_leapind_values[] = {
207 { NO_WARNING, "" },
208 { PLUS_SEC, "+1s" },
209 { MINUS_SEC, "-1s" },
210 { ALARM, "clock unsynchronized" },
211 { 0, NULL }
212 };
213
214 static const struct tok ntp_stratum_values[] = {
215 { UNSPECIFIED, "unspecified" },
216 { PRIM_REF, "primary reference" },
217 { 0, NULL }
218 };
219
220 /* draft-ietf-ntp-mode-6-cmds-02
221 * 0 1 2 3
222 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
223 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
224 * |LI | VN |Mode |R|E|M| OpCode | Sequence Number |
225 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
226 * | Status | Association ID |
227 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
228 * | Offset | Count |
229 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
230 * | |
231 * / Data (up to 468 bytes) /
232 * | |
233 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
234 * | Padding (optional) |
235 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
236 * | |
237 * / Authenticator (optional, 96 bytes) /
238 * | |
239 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
240 *
241 * Figure 1: NTP Control Message Header
242 */
243
244 /* Length of the NTP control message with the mandatory fields ("the header")
245 * and without any optional fields (Data, Padding, Authenticator).
246 */
247 #define NTP_CTRLMSG_MINLEN 12U
248
249 struct ntp_control_data {
250 nd_uint8_t magic; /* LI, VN, Mode */
251 nd_uint8_t control; /* R, E, M, OpCode */
252 nd_uint16_t sequence; /* Sequence Number */
253 nd_uint16_t status; /* Status */
254 nd_uint16_t assoc; /* Association ID */
255 nd_uint16_t offset; /* Offset */
256 nd_uint16_t count; /* Count */
257 nd_uint8_t data[564]; /* Data, [Padding, [Authenticator]] */
258 };
259
260 /*
261 * Print NTP time requests and responses
262 */
263 static void
264 ntp_time_print(netdissect_options *ndo,
265 const struct ntp_time_data *bp, u_int length)
266 {
267 uint8_t stratum;
268
269 if (length < NTP_TIMEMSG_MINLEN)
270 goto invalid;
271
272 ND_TCHECK_1(bp->stratum);
273 stratum = EXTRACT_U_1(bp->stratum);
274 ND_PRINT(", Stratum %u (%s)",
275 stratum,
276 tok2str(ntp_stratum_values, (stratum >=2 && stratum<=15) ? "secondary reference" : "reserved", stratum));
277
278 ND_TCHECK_1(bp->ppoll);
279 ND_PRINT(", poll %d", EXTRACT_S_1(bp->ppoll));
280 p_poll(ndo, EXTRACT_U_1(bp->ppoll));
281
282 ND_TCHECK_1(bp->precision);
283 ND_PRINT(", precision %d", EXTRACT_S_1(bp->precision));
284
285 ND_TCHECK_SIZE(&bp->root_delay);
286 ND_PRINT("\n\tRoot Delay: ");
287 p_sfix(ndo, &bp->root_delay);
288
289 ND_TCHECK_SIZE(&bp->root_dispersion);
290 ND_PRINT(", Root dispersion: ");
291 p_sfix(ndo, &bp->root_dispersion);
292
293 ND_TCHECK_4(bp->refid);
294 ND_PRINT(", Reference-ID: ");
295 /* Interpretation depends on stratum */
296 switch (stratum) {
297
298 case UNSPECIFIED:
299 ND_PRINT("(unspec)");
300 break;
301
302 case PRIM_REF:
303 if (fn_printn(ndo, (const u_char *)&(bp->refid), 4, ndo->ndo_snapend))
304 goto trunc;
305 break;
306
307 case INFO_QUERY:
308 ND_PRINT("%s INFO_QUERY", ipaddr_string(ndo, bp->refid));
309 /* this doesn't have more content */
310 return;
311
312 case INFO_REPLY:
313 ND_PRINT("%s INFO_REPLY", ipaddr_string(ndo, bp->refid));
314 /* this is too complex to be worth printing */
315 return;
316
317 default:
318 /* In NTPv4 (RFC 5905) refid is an IPv4 address or first 32 bits of
319 MD5 sum of IPv6 address */
320 ND_PRINT("0x%08x", EXTRACT_BE_U_4(bp->refid));
321 break;
322 }
323
324 ND_TCHECK_SIZE(&bp->ref_timestamp);
325 ND_PRINT("\n\t Reference Timestamp: ");
326 p_ntp_time(ndo, &(bp->ref_timestamp));
327
328 ND_TCHECK_SIZE(&bp->org_timestamp);
329 ND_PRINT("\n\t Originator Timestamp: ");
330 p_ntp_time(ndo, &(bp->org_timestamp));
331
332 ND_TCHECK_SIZE(&bp->rec_timestamp);
333 ND_PRINT("\n\t Receive Timestamp: ");
334 p_ntp_time(ndo, &(bp->rec_timestamp));
335
336 ND_TCHECK_SIZE(&bp->xmt_timestamp);
337 ND_PRINT("\n\t Transmit Timestamp: ");
338 p_ntp_time(ndo, &(bp->xmt_timestamp));
339
340 ND_PRINT("\n\t Originator - Receive Timestamp: ");
341 p_ntp_delta(ndo, &(bp->org_timestamp), &(bp->rec_timestamp));
342
343 ND_PRINT("\n\t Originator - Transmit Timestamp: ");
344 p_ntp_delta(ndo, &(bp->org_timestamp), &(bp->xmt_timestamp));
345
346 /* FIXME: this code is not aware of any extension fields */
347 if (length == NTP_TIMEMSG_MINLEN + 4) { /* Optional: key-id (crypto-NAK) */
348 ND_TCHECK_4(bp->key_id);
349 ND_PRINT("\n\tKey id: %u", EXTRACT_BE_U_4(bp->key_id));
350 } else if (length == NTP_TIMEMSG_MINLEN + 4 + 16) { /* Optional: key-id + 128-bit digest */
351 ND_TCHECK_4(bp->key_id);
352 ND_PRINT("\n\tKey id: %u", EXTRACT_BE_U_4(bp->key_id));
353 ND_TCHECK_LEN(bp->message_digest, 16);
354 ND_PRINT("\n\tAuthentication: %08x%08x%08x%08x",
355 EXTRACT_BE_U_4(bp->message_digest),
356 EXTRACT_BE_U_4(bp->message_digest + 4),
357 EXTRACT_BE_U_4(bp->message_digest + 8),
358 EXTRACT_BE_U_4(bp->message_digest + 12));
359 } else if (length == NTP_TIMEMSG_MINLEN + 4 + 20) { /* Optional: key-id + 160-bit digest */
360 ND_TCHECK_4(bp->key_id);
361 ND_PRINT("\n\tKey id: %u", EXTRACT_BE_U_4(bp->key_id));
362 ND_TCHECK_LEN(bp->message_digest, 20);
363 ND_PRINT("\n\tAuthentication: %08x%08x%08x%08x%08x",
364 EXTRACT_BE_U_4(bp->message_digest),
365 EXTRACT_BE_U_4(bp->message_digest + 4),
366 EXTRACT_BE_U_4(bp->message_digest + 8),
367 EXTRACT_BE_U_4(bp->message_digest + 12),
368 EXTRACT_BE_U_4(bp->message_digest + 16));
369 } else if (length > NTP_TIMEMSG_MINLEN) {
370 ND_PRINT("\n\t(%u more bytes after the header)", length - NTP_TIMEMSG_MINLEN);
371 }
372 return;
373
374 invalid:
375 ND_PRINT(" %s", istr);
376 ND_TCHECK_LEN(bp, length);
377 return;
378
379 trunc:
380 ND_PRINT(" %s", tstr);
381 }
382
383 /*
384 * Print NTP control message requests and responses
385 */
386 static void
387 ntp_control_print(netdissect_options *ndo,
388 const struct ntp_control_data *cd, u_int length)
389 {
390 uint8_t control, R, E, M, opcode;
391 uint16_t sequence, status, assoc, offset, count;
392
393 if (length < NTP_CTRLMSG_MINLEN)
394 goto invalid;
395
396 ND_TCHECK_1(cd->control);
397 control = EXTRACT_U_1(cd->control);
398 R = (control & 0x80) != 0;
399 E = (control & 0x40) != 0;
400 M = (control & 0x20) != 0;
401 opcode = control & 0x1f;
402 ND_PRINT(", %s, %s, %s, OpCode=%u\n",
403 R ? "Response" : "Request", E ? "Error" : "OK",
404 M ? "More" : "Last", opcode);
405
406 ND_TCHECK_2(cd->sequence);
407 sequence = EXTRACT_BE_U_2(cd->sequence);
408 ND_PRINT("\tSequence=%hu", sequence);
409
410 ND_TCHECK_2(cd->status);
411 status = EXTRACT_BE_U_2(cd->status);
412 ND_PRINT(", Status=%#hx", status);
413
414 ND_TCHECK_2(cd->assoc);
415 assoc = EXTRACT_BE_U_2(cd->assoc);
416 ND_PRINT(", Assoc.=%hu", assoc);
417
418 ND_TCHECK_2(cd->offset);
419 offset = EXTRACT_BE_U_2(cd->offset);
420 ND_PRINT(", Offset=%hu", offset);
421
422 ND_TCHECK_2(cd->count);
423 count = EXTRACT_BE_U_2(cd->count);
424 ND_PRINT(", Count=%hu", count);
425
426 if (NTP_CTRLMSG_MINLEN + count > length)
427 goto invalid;
428 if (count != 0) {
429 ND_TCHECK_LEN(cd->data, count);
430 ND_PRINT("\n\tTO-BE-DONE: data not interpreted");
431 }
432 return;
433
434 invalid:
435 ND_PRINT(" %s", istr);
436 ND_TCHECK_LEN(cd, length);
437 return;
438
439 trunc:
440 ND_PRINT(" %s", tstr);
441 }
442
443 union ntpdata {
444 struct ntp_time_data td;
445 struct ntp_control_data cd;
446 };
447
448 /*
449 * Print NTP requests, handling the common VN, LI, and Mode
450 */
451 void
452 ntp_print(netdissect_options *ndo,
453 const u_char *cp, u_int length)
454 {
455 const union ntpdata *bp = (const union ntpdata *)cp;
456 u_int mode, version, leapind;
457 uint8_t status;
458
459 ND_TCHECK_1(bp->td.status);
460 status = EXTRACT_U_1(bp->td.status);
461
462 version = (status & VERSIONMASK) >> VERSIONSHIFT;
463 ND_PRINT("NTPv%u", version);
464
465 mode = (status & MODEMASK) >> MODESHIFT;
466 if (!ndo->ndo_vflag) {
467 ND_PRINT(", %s, length %u",
468 tok2str(ntp_mode_values, "Unknown mode", mode),
469 length);
470 return;
471 }
472
473 ND_PRINT(", %s, length %u\n",
474 tok2str(ntp_mode_values, "Unknown mode", mode), length);
475
476 /* leapind = (status & LEAPMASK) >> LEAPSHIFT; */
477 leapind = (status & LEAPMASK);
478 ND_PRINT("\tLeap indicator: %s (%u)",
479 tok2str(ntp_leapind_values, "Unknown", leapind),
480 leapind);
481
482 switch (mode) {
483
484 case MODE_UNSPEC:
485 case MODE_SYM_ACT:
486 case MODE_SYM_PAS:
487 case MODE_CLIENT:
488 case MODE_SERVER:
489 case MODE_BROADCAST:
490 ntp_time_print(ndo, &bp->td, length);
491 break;
492
493 case MODE_CONTROL:
494 ntp_control_print(ndo, &bp->cd, length);
495 break;
496
497 default:
498 break; /* XXX: not implemented! */
499 }
500 return;
501
502 trunc:
503 ND_PRINT(" %s", tstr);
504 }
505
506 static void
507 p_sfix(netdissect_options *ndo,
508 const struct s_fixedpt *sfp)
509 {
510 int i;
511 int f;
512 double ff;
513
514 i = EXTRACT_BE_U_2(sfp->int_part);
515 f = EXTRACT_BE_U_2(sfp->fraction);
516 ff = f / 65536.0; /* shift radix point by 16 bits */
517 f = (int)(ff * 1000000.0); /* Treat fraction as parts per million */
518 ND_PRINT("%d.%06d", i, f);
519 }
520
521 #define FMAXINT (4294967296.0) /* floating point rep. of MAXINT */
522
523 static void
524 p_ntp_time(netdissect_options *ndo,
525 const struct l_fixedpt *lfp)
526 {
527 uint32_t i;
528 uint32_t uf;
529 uint32_t f;
530 double ff;
531
532 i = EXTRACT_BE_U_4(lfp->int_part);
533 uf = EXTRACT_BE_U_4(lfp->fraction);
534 ff = uf;
535 if (ff < 0.0) /* some compilers are buggy */
536 ff += FMAXINT;
537 ff = ff / FMAXINT; /* shift radix point by 32 bits */
538 f = (uint32_t)(ff * 1000000000.0); /* treat fraction as parts per billion */
539 ND_PRINT("%u.%09d", i, f);
540
541 #ifdef HAVE_STRFTIME
542 /*
543 * print the UTC time in human-readable format.
544 */
545 if (i) {
546 int64_t seconds_64bit = (int64_t)i - JAN_1970;
547 time_t seconds;
548 struct tm *tm;
549 char time_buf[128];
550
551 seconds = (time_t)seconds_64bit;
552 if (seconds != seconds_64bit) {
553 /*
554 * It doesn't fit into a time_t, so we can't hand it
555 * to gmtime.
556 */
557 ND_PRINT(" (unrepresentable)");
558 } else {
559 tm = gmtime(&seconds);
560 if (tm == NULL) {
561 /*
562 * gmtime() can't handle it.
563 * (Yes, that might happen with some version of
564 * Microsoft's C library.)
565 */
566 ND_PRINT(" (unrepresentable)");
567 } else {
568 /* use ISO 8601 (RFC3339) format */
569 strftime(time_buf, sizeof (time_buf), "%Y-%m-%dT%H:%M:%S", tm);
570 ND_PRINT(" (%s)", time_buf);
571 }
572 }
573 }
574 #endif
575 }
576
577 /* Prints time difference between *lfp and *olfp */
578 static void
579 p_ntp_delta(netdissect_options *ndo,
580 const struct l_fixedpt *olfp,
581 const struct l_fixedpt *lfp)
582 {
583 int32_t i;
584 uint32_t u, uf;
585 uint32_t ou, ouf;
586 uint32_t f;
587 double ff;
588 int signbit;
589
590 u = EXTRACT_BE_U_4(lfp->int_part);
591 ou = EXTRACT_BE_U_4(olfp->int_part);
592 uf = EXTRACT_BE_U_4(lfp->fraction);
593 ouf = EXTRACT_BE_U_4(olfp->fraction);
594 if (ou == 0 && ouf == 0) {
595 p_ntp_time(ndo, lfp);
596 return;
597 }
598
599 i = u - ou;
600
601 if (i > 0) { /* new is definitely greater than old */
602 signbit = 0;
603 f = uf - ouf;
604 if (ouf > uf) /* must borrow from high-order bits */
605 i -= 1;
606 } else if (i < 0) { /* new is definitely less than old */
607 signbit = 1;
608 f = ouf - uf;
609 if (uf > ouf) /* must carry into the high-order bits */
610 i += 1;
611 i = -i;
612 } else { /* int_part is zero */
613 if (uf > ouf) {
614 signbit = 0;
615 f = uf - ouf;
616 } else {
617 signbit = 1;
618 f = ouf - uf;
619 }
620 }
621
622 ff = f;
623 if (ff < 0.0) /* some compilers are buggy */
624 ff += FMAXINT;
625 ff = ff / FMAXINT; /* shift radix point by 32 bits */
626 f = (uint32_t)(ff * 1000000000.0); /* treat fraction as parts per billion */
627 ND_PRINT("%s%d.%09d", signbit ? "-" : "+", i, f);
628 }
629
630 /* Prints polling interval in log2 as seconds or fraction of second */
631 static void
632 p_poll(netdissect_options *ndo,
633 const int poll_interval)
634 {
635 if (poll_interval <= -32 || poll_interval >= 32)
636 return;
637
638 if (poll_interval >= 0)
639 ND_PRINT(" (%us)", 1U << poll_interval);
640 else
641 ND_PRINT(" (1/%us)", 1U << -poll_interval);
642 }
643
[mirror] the TCPdump network dissector