print-ntp.c revision 313537 
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*/
68struct l_fixedpt {
69	uint32_t int_part;
70	uint32_t fraction;
71};
72
73struct 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
116struct 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
170static void p_sfix(netdissect_options *ndo, const struct s_fixedpt *);
171static void p_ntp_time(netdissect_options *, const struct l_fixedpt *);
172static void p_ntp_delta(netdissect_options *, const struct l_fixedpt *, const struct l_fixedpt *);
173
174static 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
186static 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
194static 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 */
203void
204ntp_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
320trunc:
321	ND_PRINT((ndo, " [|ntp]"));
322}
323
324static void
325p_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
341static void
342p_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 */
376static void
377p_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