xref: /freebsd/contrib/tcpdump/print-ntp.c (revision dd41de95a84d979615a2ef11df6850622bf6184e)
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 #ifdef HAVE_CONFIG_H
28 #include "config.h"
29 #endif
30 
31 #include <netdissect-stdinc.h>
32 
33 #ifdef HAVE_STRFTIME
34 #include <time.h>
35 #endif
36 
37 #include "netdissect.h"
38 #include "addrtoname.h"
39 #include "extract.h"
40 
41 /*
42  * Based on ntp.h from the U of MD implementation
43  *	This file is based on Version 2 of the NTP spec (RFC1119).
44  */
45 
46 /*
47  *  Definitions for the masses
48  */
49 #define	JAN_1970	2208988800U	/* 1970 - 1900 in seconds */
50 
51 /*
52  * Structure definitions for NTP fixed point values
53  *
54  *    0			  1		      2			  3
55  *    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
56  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
57  *   |			       Integer Part			     |
58  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
59  *   |			       Fraction Part			     |
60  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
61  *
62  *    0			  1		      2			  3
63  *    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
64  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
65  *   |		  Integer Part	     |	   Fraction Part	     |
66  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
67 */
68 struct l_fixedpt {
69 	uint32_t int_part;
70 	uint32_t fraction;
71 };
72 
73 struct s_fixedpt {
74 	uint16_t int_part;
75 	uint16_t fraction;
76 };
77 
78 /* rfc2030
79  *                      1                   2                   3
80  *  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
81  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
82  * |LI | VN  |Mode |    Stratum    |     Poll      |   Precision   |
83  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
84  * |                          Root Delay                           |
85  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
86  * |                       Root Dispersion                         |
87  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
88  * |                     Reference Identifier                      |
89  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
90  * |                                                               |
91  * |                   Reference Timestamp (64)                    |
92  * |                                                               |
93  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
94  * |                                                               |
95  * |                   Originate Timestamp (64)                    |
96  * |                                                               |
97  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
98  * |                                                               |
99  * |                    Receive Timestamp (64)                     |
100  * |                                                               |
101  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
102  * |                                                               |
103  * |                    Transmit Timestamp (64)                    |
104  * |                                                               |
105  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
106  * |                 Key Identifier (optional) (32)                |
107  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
108  * |                                                               |
109  * |                                                               |
110  * |                 Message Digest (optional) (128)               |
111  * |                                                               |
112  * |                                                               |
113  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
114  */
115 
116 struct ntpdata {
117 	u_char status;		/* status of local clock and leap info */
118 	u_char stratum;		/* Stratum level */
119 	u_char ppoll;		/* poll value */
120 	int precision:8;
121 	struct s_fixedpt root_delay;
122 	struct s_fixedpt root_dispersion;
123 	uint32_t refid;
124 	struct l_fixedpt ref_timestamp;
125 	struct l_fixedpt org_timestamp;
126 	struct l_fixedpt rec_timestamp;
127 	struct l_fixedpt xmt_timestamp;
128         uint32_t key_id;
129         uint8_t  message_digest[16];
130 };
131 /*
132  *	Leap Second Codes (high order two bits)
133  */
134 #define	NO_WARNING	0x00	/* no warning */
135 #define	PLUS_SEC	0x40	/* add a second (61 seconds) */
136 #define	MINUS_SEC	0x80	/* minus a second (59 seconds) */
137 #define	ALARM		0xc0	/* alarm condition (clock unsynchronized) */
138 
139 /*
140  *	Clock Status Bits that Encode Version
141  */
142 #define	NTPVERSION_1	0x08
143 #define	VERSIONMASK	0x38
144 #define LEAPMASK	0xc0
145 #ifdef MODEMASK
146 #undef MODEMASK					/* Solaris sucks */
147 #endif
148 #define	MODEMASK	0x07
149 
150 /*
151  *	Code values
152  */
153 #define	MODE_UNSPEC	0	/* unspecified */
154 #define	MODE_SYM_ACT	1	/* symmetric active */
155 #define	MODE_SYM_PAS	2	/* symmetric passive */
156 #define	MODE_CLIENT	3	/* client */
157 #define	MODE_SERVER	4	/* server */
158 #define	MODE_BROADCAST	5	/* broadcast */
159 #define	MODE_RES1	6	/* reserved */
160 #define	MODE_RES2	7	/* reserved */
161 
162 /*
163  *	Stratum Definitions
164  */
165 #define	UNSPECIFIED	0
166 #define	PRIM_REF	1	/* radio clock */
167 #define	INFO_QUERY	62	/* **** THIS implementation dependent **** */
168 #define	INFO_REPLY	63	/* **** THIS implementation dependent **** */
169 
170 static void p_sfix(netdissect_options *ndo, const struct s_fixedpt *);
171 static void p_ntp_time(netdissect_options *, const struct l_fixedpt *);
172 static void p_ntp_delta(netdissect_options *, const struct l_fixedpt *, const struct l_fixedpt *);
173 
174 static const struct tok ntp_mode_values[] = {
175     { MODE_UNSPEC,    "unspecified" },
176     { MODE_SYM_ACT,   "symmetric active" },
177     { MODE_SYM_PAS,   "symmetric passive" },
178     { MODE_CLIENT,    "Client" },
179     { MODE_SERVER,    "Server" },
180     { MODE_BROADCAST, "Broadcast" },
181     { MODE_RES1,      "Reserved" },
182     { MODE_RES2,      "Reserved" },
183     { 0, NULL }
184 };
185 
186 static const struct tok ntp_leapind_values[] = {
187     { NO_WARNING,     "" },
188     { PLUS_SEC,       "+1s" },
189     { MINUS_SEC,      "-1s" },
190     { ALARM,          "clock unsynchronized" },
191     { 0, NULL }
192 };
193 
194 static const struct tok ntp_stratum_values[] = {
195 	{ UNSPECIFIED,	"unspecified" },
196 	{ PRIM_REF, 	"primary reference" },
197 	{ 0, NULL }
198 };
199 
200 /*
201  * Print ntp requests
202  */
203 void
204 ntp_print(netdissect_options *ndo,
205           register const u_char *cp, u_int length)
206 {
207 	register const struct ntpdata *bp;
208 	int mode, version, leapind;
209 
210 	bp = (const struct ntpdata *)cp;
211 
212 	ND_TCHECK(bp->status);
213 
214 	version = (int)(bp->status & VERSIONMASK) >> 3;
215 	ND_PRINT((ndo, "NTPv%d", version));
216 
217 	mode = bp->status & MODEMASK;
218 	if (!ndo->ndo_vflag) {
219 		ND_PRINT((ndo, ", %s, length %u",
220 		          tok2str(ntp_mode_values, "Unknown mode", mode),
221 		          length));
222 		return;
223 	}
224 
225 	ND_PRINT((ndo, ", length %u\n\t%s",
226 	          length,
227 	          tok2str(ntp_mode_values, "Unknown mode", mode)));
228 
229 	leapind = bp->status & LEAPMASK;
230 	ND_PRINT((ndo, ", Leap indicator: %s (%u)",
231 	          tok2str(ntp_leapind_values, "Unknown", leapind),
232 	          leapind));
233 
234 	ND_TCHECK(bp->stratum);
235 	ND_PRINT((ndo, ", Stratum %u (%s)",
236 		bp->stratum,
237 		tok2str(ntp_stratum_values, (bp->stratum >=2 && bp->stratum<=15) ? "secondary reference" : "reserved", bp->stratum)));
238 
239 	ND_TCHECK(bp->ppoll);
240 	ND_PRINT((ndo, ", poll %u (%us)", bp->ppoll, 1 << bp->ppoll));
241 
242 	/* Can't ND_TCHECK bp->precision bitfield so bp->distance + 0 instead */
243 	ND_TCHECK2(bp->root_delay, 0);
244 	ND_PRINT((ndo, ", precision %d", bp->precision));
245 
246 	ND_TCHECK(bp->root_delay);
247 	ND_PRINT((ndo, "\n\tRoot Delay: "));
248 	p_sfix(ndo, &bp->root_delay);
249 
250 	ND_TCHECK(bp->root_dispersion);
251 	ND_PRINT((ndo, ", Root dispersion: "));
252 	p_sfix(ndo, &bp->root_dispersion);
253 
254 	ND_TCHECK(bp->refid);
255 	ND_PRINT((ndo, ", Reference-ID: "));
256 	/* Interpretation depends on stratum */
257 	switch (bp->stratum) {
258 
259 	case UNSPECIFIED:
260 		ND_PRINT((ndo, "(unspec)"));
261 		break;
262 
263 	case PRIM_REF:
264 		if (fn_printn(ndo, (const u_char *)&(bp->refid), 4, ndo->ndo_snapend))
265 			goto trunc;
266 		break;
267 
268 	case INFO_QUERY:
269 		ND_PRINT((ndo, "%s INFO_QUERY", ipaddr_string(ndo, &(bp->refid))));
270 		/* this doesn't have more content */
271 		return;
272 
273 	case INFO_REPLY:
274 		ND_PRINT((ndo, "%s INFO_REPLY", ipaddr_string(ndo, &(bp->refid))));
275 		/* this is too complex to be worth printing */
276 		return;
277 
278 	default:
279 		ND_PRINT((ndo, "%s", ipaddr_string(ndo, &(bp->refid))));
280 		break;
281 	}
282 
283 	ND_TCHECK(bp->ref_timestamp);
284 	ND_PRINT((ndo, "\n\t  Reference Timestamp:  "));
285 	p_ntp_time(ndo, &(bp->ref_timestamp));
286 
287 	ND_TCHECK(bp->org_timestamp);
288 	ND_PRINT((ndo, "\n\t  Originator Timestamp: "));
289 	p_ntp_time(ndo, &(bp->org_timestamp));
290 
291 	ND_TCHECK(bp->rec_timestamp);
292 	ND_PRINT((ndo, "\n\t  Receive Timestamp:    "));
293 	p_ntp_time(ndo, &(bp->rec_timestamp));
294 
295 	ND_TCHECK(bp->xmt_timestamp);
296 	ND_PRINT((ndo, "\n\t  Transmit Timestamp:   "));
297 	p_ntp_time(ndo, &(bp->xmt_timestamp));
298 
299 	ND_PRINT((ndo, "\n\t    Originator - Receive Timestamp:  "));
300 	p_ntp_delta(ndo, &(bp->org_timestamp), &(bp->rec_timestamp));
301 
302 	ND_PRINT((ndo, "\n\t    Originator - Transmit Timestamp: "));
303 	p_ntp_delta(ndo, &(bp->org_timestamp), &(bp->xmt_timestamp));
304 
305 	if ( (sizeof(struct ntpdata) - length) == 16) { 	/* Optional: key-id */
306 		ND_TCHECK(bp->key_id);
307 		ND_PRINT((ndo, "\n\tKey id: %u", bp->key_id));
308 	} else if ( (sizeof(struct ntpdata) - length) == 0) { 	/* Optional: key-id + authentication */
309 		ND_TCHECK(bp->key_id);
310 		ND_PRINT((ndo, "\n\tKey id: %u", bp->key_id));
311 		ND_TCHECK2(bp->message_digest, sizeof (bp->message_digest));
312                 ND_PRINT((ndo, "\n\tAuthentication: %08x%08x%08x%08x",
313         		       EXTRACT_32BITS(bp->message_digest),
314 		               EXTRACT_32BITS(bp->message_digest + 4),
315 		               EXTRACT_32BITS(bp->message_digest + 8),
316 		               EXTRACT_32BITS(bp->message_digest + 12)));
317         }
318 	return;
319 
320 trunc:
321 	ND_PRINT((ndo, " [|ntp]"));
322 }
323 
324 static void
325 p_sfix(netdissect_options *ndo,
326        register const struct s_fixedpt *sfp)
327 {
328 	register int i;
329 	register int f;
330 	register double ff;
331 
332 	i = EXTRACT_16BITS(&sfp->int_part);
333 	f = EXTRACT_16BITS(&sfp->fraction);
334 	ff = f / 65536.0;		/* shift radix point by 16 bits */
335 	f = (int)(ff * 1000000.0);	/* Treat fraction as parts per million */
336 	ND_PRINT((ndo, "%d.%06d", i, f));
337 }
338 
339 #define	FMAXINT	(4294967296.0)	/* floating point rep. of MAXINT */
340 
341 static void
342 p_ntp_time(netdissect_options *ndo,
343            register const struct l_fixedpt *lfp)
344 {
345 	register int32_t i;
346 	register uint32_t uf;
347 	register uint32_t f;
348 	register double ff;
349 
350 	i = EXTRACT_32BITS(&lfp->int_part);
351 	uf = EXTRACT_32BITS(&lfp->fraction);
352 	ff = uf;
353 	if (ff < 0.0)		/* some compilers are buggy */
354 		ff += FMAXINT;
355 	ff = ff / FMAXINT;			/* shift radix point by 32 bits */
356 	f = (uint32_t)(ff * 1000000000.0);	/* treat fraction as parts per billion */
357 	ND_PRINT((ndo, "%u.%09d", i, f));
358 
359 #ifdef HAVE_STRFTIME
360 	/*
361 	 * print the time in human-readable format.
362 	 */
363 	if (i) {
364 	    time_t seconds = i - JAN_1970;
365 	    struct tm *tm;
366 	    char time_buf[128];
367 
368 	    tm = localtime(&seconds);
369 	    strftime(time_buf, sizeof (time_buf), "%Y/%m/%d %H:%M:%S", tm);
370 	    ND_PRINT((ndo, " (%s)", time_buf));
371 	}
372 #endif
373 }
374 
375 /* Prints time difference between *lfp and *olfp */
376 static void
377 p_ntp_delta(netdissect_options *ndo,
378             register const struct l_fixedpt *olfp,
379             register const struct l_fixedpt *lfp)
380 {
381 	register int32_t i;
382 	register uint32_t u, uf;
383 	register uint32_t ou, ouf;
384 	register uint32_t f;
385 	register double ff;
386 	int signbit;
387 
388 	u = EXTRACT_32BITS(&lfp->int_part);
389 	ou = EXTRACT_32BITS(&olfp->int_part);
390 	uf = EXTRACT_32BITS(&lfp->fraction);
391 	ouf = EXTRACT_32BITS(&olfp->fraction);
392 	if (ou == 0 && ouf == 0) {
393 		p_ntp_time(ndo, lfp);
394 		return;
395 	}
396 
397 	i = u - ou;
398 
399 	if (i > 0) {		/* new is definitely greater than old */
400 		signbit = 0;
401 		f = uf - ouf;
402 		if (ouf > uf)	/* must borrow from high-order bits */
403 			i -= 1;
404 	} else if (i < 0) {	/* new is definitely less than old */
405 		signbit = 1;
406 		f = ouf - uf;
407 		if (uf > ouf)	/* must carry into the high-order bits */
408 			i += 1;
409 		i = -i;
410 	} else {		/* int_part is zero */
411 		if (uf > ouf) {
412 			signbit = 0;
413 			f = uf - ouf;
414 		} else {
415 			signbit = 1;
416 			f = ouf - uf;
417 		}
418 	}
419 
420 	ff = f;
421 	if (ff < 0.0)		/* some compilers are buggy */
422 		ff += FMAXINT;
423 	ff = ff / FMAXINT;			/* shift radix point by 32 bits */
424 	f = (uint32_t)(ff * 1000000000.0);	/* treat fraction as parts per billion */
425 	ND_PRINT((ndo, "%s%d.%09d", signbit ? "-" : "+", i, f));
426 }
427 
428