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 * Format and print ntp packets.
22 *	By Jeffrey Mogul/DECWRL
23 *	loosely based on print-bootp.c
24 */
25
26#ifndef lint
27static const char rcsid[] _U_ =
28    "@(#) $Header: /tcpdump/master/tcpdump/print-ntp.c,v 1.43 2007-11-30 13:45:10 hannes Exp $ (LBL)";
29#endif
30
31#ifdef HAVE_CONFIG_H
32#include "config.h"
33#endif
34
35#include <tcpdump-stdinc.h>
36
37#include <stdio.h>
38#include <string.h>
39#ifdef HAVE_STRFTIME
40#include <time.h>
41#endif
42
43#include "interface.h"
44#include "addrtoname.h"
45#include "extract.h"
46#ifdef MODEMASK
47#undef MODEMASK					/* Solaris sucks */
48#endif
49#include "ntp.h"
50
51static void p_sfix(const struct s_fixedpt *);
52static void p_ntp_time(const struct l_fixedpt *);
53static void p_ntp_delta(const struct l_fixedpt *, const struct l_fixedpt *);
54
55static const struct tok ntp_mode_values[] = {
56    { MODE_UNSPEC,    "unspecified" },
57    { MODE_SYM_ACT,   "symmetric active" },
58    { MODE_SYM_PAS,   "symmetric passive" },
59    { MODE_CLIENT,    "Client" },
60    { MODE_SERVER,    "Server" },
61    { MODE_BROADCAST, "Broadcast" },
62    { MODE_RES1,      "Reserved" },
63    { MODE_RES2,      "Reserved" },
64    { 0, NULL }
65};
66
67static const struct tok ntp_leapind_values[] = {
68    { NO_WARNING,     "" },
69    { PLUS_SEC,       "+1s" },
70    { MINUS_SEC,      "-1s" },
71    { ALARM,          "clock unsynchronized" },
72    { 0, NULL }
73};
74
75static const struct tok ntp_stratum_values[] = {
76	{ UNSPECIFIED,	"unspecified" },
77	{ PRIM_REF, 	"primary reference" },
78	{ 0, NULL }
79};
80
81/*
82 * Print ntp requests
83 */
84void
85ntp_print(register const u_char *cp, u_int length)
86{
87	register const struct ntpdata *bp;
88	int mode, version, leapind;
89
90	bp = (struct ntpdata *)cp;
91
92	TCHECK(bp->status);
93
94	version = (int)(bp->status & VERSIONMASK) >> 3;
95	printf("NTPv%d", version);
96
97	mode = bp->status & MODEMASK;
98        if (!vflag) {
99            printf (", %s, length %u",
100                    tok2str(ntp_mode_values, "Unknown mode", mode),
101                    length);
102            return;
103        }
104
105        printf (", length %u\n\t%s",
106                length,
107                tok2str(ntp_mode_values, "Unknown mode", mode));
108
109	leapind = bp->status & LEAPMASK;
110        printf (", Leap indicator: %s (%u)",
111                tok2str(ntp_leapind_values, "Unknown", leapind),
112                leapind);
113
114	TCHECK(bp->stratum);
115	printf(", Stratum %u (%s)",
116		bp->stratum,
117		tok2str(ntp_stratum_values, (bp->stratum >=2 && bp->stratum<=15) ? "secondary reference" : "reserved", bp->stratum));
118
119	TCHECK(bp->ppoll);
120	printf(", poll %u (%us)", bp->ppoll, 1 << bp->ppoll);
121
122	/* Can't TCHECK bp->precision bitfield so bp->distance + 0 instead */
123	TCHECK2(bp->root_delay, 0);
124	printf(", precision %d", bp->precision);
125
126	TCHECK(bp->root_delay);
127	fputs("\n\tRoot Delay: ", stdout);
128	p_sfix(&bp->root_delay);
129
130	TCHECK(bp->root_dispersion);
131	fputs(", Root dispersion: ", stdout);
132	p_sfix(&bp->root_dispersion);
133
134	TCHECK(bp->refid);
135	fputs(", Reference-ID: ", stdout);
136	/* Interpretation depends on stratum */
137	switch (bp->stratum) {
138
139	case UNSPECIFIED:
140		printf("(unspec)");
141		break;
142
143	case PRIM_REF:
144		if (fn_printn((u_char *)&(bp->refid), 4, snapend))
145			goto trunc;
146		break;
147
148	case INFO_QUERY:
149		printf("%s INFO_QUERY", ipaddr_string(&(bp->refid)));
150		/* this doesn't have more content */
151		return;
152
153	case INFO_REPLY:
154		printf("%s INFO_REPLY", ipaddr_string(&(bp->refid)));
155		/* this is too complex to be worth printing */
156		return;
157
158	default:
159		printf("%s", ipaddr_string(&(bp->refid)));
160		break;
161	}
162
163	TCHECK(bp->ref_timestamp);
164	fputs("\n\t  Reference Timestamp:  ", stdout);
165	p_ntp_time(&(bp->ref_timestamp));
166
167	TCHECK(bp->org_timestamp);
168	fputs("\n\t  Originator Timestamp: ", stdout);
169	p_ntp_time(&(bp->org_timestamp));
170
171	TCHECK(bp->rec_timestamp);
172	fputs("\n\t  Receive Timestamp:    ", stdout);
173	p_ntp_time(&(bp->rec_timestamp));
174
175	TCHECK(bp->xmt_timestamp);
176	fputs("\n\t  Transmit Timestamp:   ", stdout);
177	p_ntp_time(&(bp->xmt_timestamp));
178
179	fputs("\n\t    Originator - Receive Timestamp:  ", stdout);
180	p_ntp_delta(&(bp->org_timestamp), &(bp->rec_timestamp));
181
182	fputs("\n\t    Originator - Transmit Timestamp: ", stdout);
183	p_ntp_delta(&(bp->org_timestamp), &(bp->xmt_timestamp));
184
185	if ( (sizeof(struct ntpdata) - length) == 16) { 	/* Optional: key-id */
186		TCHECK(bp->key_id);
187		printf("\n\tKey id: %u", bp->key_id);
188	} else if ( (sizeof(struct ntpdata) - length) == 0) { 	/* Optional: key-id + authentication */
189		TCHECK(bp->key_id);
190		printf("\n\tKey id: %u", bp->key_id);
191		TCHECK2(bp->message_digest, sizeof (bp->message_digest));
192                printf("\n\tAuthentication: %08x%08x%08x%08x",
193        		       EXTRACT_32BITS(bp->message_digest),
194		               EXTRACT_32BITS(bp->message_digest + 4),
195		               EXTRACT_32BITS(bp->message_digest + 8),
196		               EXTRACT_32BITS(bp->message_digest + 12));
197        }
198	return;
199
200trunc:
201	fputs(" [|ntp]", stdout);
202}
203
204static void
205p_sfix(register const struct s_fixedpt *sfp)
206{
207	register int i;
208	register int f;
209	register float ff;
210
211	i = EXTRACT_16BITS(&sfp->int_part);
212	f = EXTRACT_16BITS(&sfp->fraction);
213	ff = f / 65536.0;	/* shift radix point by 16 bits */
214	f = ff * 1000000.0;	/* Treat fraction as parts per million */
215	printf("%d.%06d", i, f);
216}
217
218#define	FMAXINT	(4294967296.0)	/* floating point rep. of MAXINT */
219
220static void
221p_ntp_time(register const struct l_fixedpt *lfp)
222{
223	register int32_t i;
224	register u_int32_t uf;
225	register u_int32_t f;
226	register float ff;
227
228	i = EXTRACT_32BITS(&lfp->int_part);
229	uf = EXTRACT_32BITS(&lfp->fraction);
230	ff = uf;
231	if (ff < 0.0)		/* some compilers are buggy */
232		ff += FMAXINT;
233	ff = ff / FMAXINT;	/* shift radix point by 32 bits */
234	f = ff * 1000000000.0;	/* treat fraction as parts per billion */
235	printf("%u.%09d", i, f);
236
237#ifdef HAVE_STRFTIME
238	/*
239	 * print the time in human-readable format.
240	 */
241	if (i) {
242	    time_t seconds = i - JAN_1970;
243	    struct tm *tm;
244	    char time_buf[128];
245
246	    tm = localtime(&seconds);
247	    strftime(time_buf, sizeof (time_buf), "%Y/%m/%d %H:%M:%S", tm);
248	    printf (" (%s)", time_buf);
249	}
250#endif
251}
252
253/* Prints time difference between *lfp and *olfp */
254static void
255p_ntp_delta(register const struct l_fixedpt *olfp,
256	    register const struct l_fixedpt *lfp)
257{
258	register int32_t i;
259	register u_int32_t u, uf;
260	register u_int32_t ou, ouf;
261	register u_int32_t f;
262	register float ff;
263	int signbit;
264
265	u = EXTRACT_32BITS(&lfp->int_part);
266	ou = EXTRACT_32BITS(&olfp->int_part);
267	uf = EXTRACT_32BITS(&lfp->fraction);
268	ouf = EXTRACT_32BITS(&olfp->fraction);
269	if (ou == 0 && ouf == 0) {
270		p_ntp_time(lfp);
271		return;
272	}
273
274	i = u - ou;
275
276	if (i > 0) {		/* new is definitely greater than old */
277		signbit = 0;
278		f = uf - ouf;
279		if (ouf > uf)	/* must borrow from high-order bits */
280			i -= 1;
281	} else if (i < 0) {	/* new is definitely less than old */
282		signbit = 1;
283		f = ouf - uf;
284		if (uf > ouf)	/* must carry into the high-order bits */
285			i += 1;
286		i = -i;
287	} else {		/* int_part is zero */
288		if (uf > ouf) {
289			signbit = 0;
290			f = uf - ouf;
291		} else {
292			signbit = 1;
293			f = ouf - uf;
294		}
295	}
296
297	ff = f;
298	if (ff < 0.0)		/* some compilers are buggy */
299		ff += FMAXINT;
300	ff = ff / FMAXINT;	/* shift radix point by 32 bits */
301	f = ff * 1000000000.0;	/* treat fraction as parts per billion */
302	if (signbit)
303		putchar('-');
304	else
305		putchar('+');
306	printf("%d.%09d", i, f);
307}
308
309