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 * $FreeBSD$
26 */
27
28#ifndef lint
29static const char rcsid[] _U_ =
30    "@(#) $Header: /tcpdump/master/tcpdump/print-ntp.c,v 1.43 2007-11-30 13:45:10 hannes Exp $ (LBL)";
31#endif
32
33#ifdef HAVE_CONFIG_H
34#include "config.h"
35#endif
36
37#include <tcpdump-stdinc.h>
38
39#include <stdio.h>
40#include <string.h>
41#ifdef HAVE_STRFTIME
42#include <time.h>
43#endif
44
45#include "interface.h"
46#include "addrtoname.h"
47#include "extract.h"
48#ifdef MODEMASK
49#undef MODEMASK					/* Solaris sucks */
50#endif
51#include "ntp.h"
52
53static void p_sfix(const struct s_fixedpt *);
54static void p_ntp_time(const struct l_fixedpt *);
55static void p_ntp_delta(const struct l_fixedpt *, const struct l_fixedpt *);
56
57static struct tok ntp_mode_values[] = {
58    { MODE_UNSPEC,    "unspecified" },
59    { MODE_SYM_ACT,   "symmetric active" },
60    { MODE_SYM_PAS,   "symmetric passive" },
61    { MODE_CLIENT,    "Client" },
62    { MODE_SERVER,    "Server" },
63    { MODE_BROADCAST, "Broadcast" },
64    { MODE_RES1,      "Reserved" },
65    { MODE_RES2,      "Reserved" },
66    { 0, NULL }
67};
68
69static struct tok ntp_leapind_values[] = {
70    { NO_WARNING,     "" },
71    { PLUS_SEC,       "+1s" },
72    { MINUS_SEC,      "-1s" },
73    { ALARM,          "clock unsynchronized" },
74    { 0, NULL }
75};
76
77static struct tok ntp_stratum_values[] = {
78	{ UNSPECIFIED,	"unspecified" },
79	{ PRIM_REF, 	"primary reference" },
80	{ 0, NULL }
81};
82
83/*
84 * Print ntp requests
85 */
86void
87ntp_print(register const u_char *cp, u_int length)
88{
89	register const struct ntpdata *bp;
90	int mode, version, leapind;
91
92	bp = (struct ntpdata *)cp;
93
94	TCHECK(bp->status);
95
96	version = (int)(bp->status & VERSIONMASK) >> 3;
97	printf("NTPv%d", version);
98
99	mode = bp->status & MODEMASK;
100        if (!vflag) {
101            printf (", %s, length %u",
102                    tok2str(ntp_mode_values, "Unknown mode", mode),
103                    length);
104            return;
105        }
106
107        printf (", length %u\n\t%s",
108                length,
109                tok2str(ntp_mode_values, "Unknown mode", mode));
110
111	leapind = bp->status & LEAPMASK;
112        printf (", Leap indicator: %s (%u)",
113                tok2str(ntp_leapind_values, "Unknown", leapind),
114                leapind);
115
116	TCHECK(bp->stratum);
117	printf(", Stratum %u (%s)",
118		bp->stratum,
119		tok2str(ntp_stratum_values, (bp->stratum >=2 && bp->stratum<=15) ? "secondary reference" : "reserved", bp->stratum));
120
121	TCHECK(bp->ppoll);
122	printf(", poll %u (%us)", bp->ppoll, 1 << bp->ppoll);
123
124	/* Can't TCHECK bp->precision bitfield so bp->distance + 0 instead */
125	TCHECK2(bp->root_delay, 0);
126	printf(", precision %d", bp->precision);
127
128	TCHECK(bp->root_delay);
129	fputs("\n\tRoot Delay: ", stdout);
130	p_sfix(&bp->root_delay);
131
132	TCHECK(bp->root_dispersion);
133	fputs(", Root dispersion: ", stdout);
134	p_sfix(&bp->root_dispersion);
135
136	TCHECK(bp->refid);
137	fputs(", Reference-ID: ", stdout);
138	/* Interpretation depends on stratum */
139	switch (bp->stratum) {
140
141	case UNSPECIFIED:
142		printf("(unspec)");
143		break;
144
145	case PRIM_REF:
146		if (fn_printn((u_char *)&(bp->refid), 4, snapend))
147			goto trunc;
148		break;
149
150	case INFO_QUERY:
151		printf("%s INFO_QUERY", ipaddr_string(&(bp->refid)));
152		/* this doesn't have more content */
153		return;
154
155	case INFO_REPLY:
156		printf("%s INFO_REPLY", ipaddr_string(&(bp->refid)));
157		/* this is too complex to be worth printing */
158		return;
159
160	default:
161		printf("%s", ipaddr_string(&(bp->refid)));
162		break;
163	}
164
165	TCHECK(bp->ref_timestamp);
166	fputs("\n\t  Reference Timestamp:  ", stdout);
167	p_ntp_time(&(bp->ref_timestamp));
168
169	TCHECK(bp->org_timestamp);
170	fputs("\n\t  Originator Timestamp: ", stdout);
171	p_ntp_time(&(bp->org_timestamp));
172
173	TCHECK(bp->rec_timestamp);
174	fputs("\n\t  Receive Timestamp:    ", stdout);
175	p_ntp_time(&(bp->rec_timestamp));
176
177	TCHECK(bp->xmt_timestamp);
178	fputs("\n\t  Transmit Timestamp:   ", stdout);
179	p_ntp_time(&(bp->xmt_timestamp));
180
181	fputs("\n\t    Originator - Receive Timestamp:  ", stdout);
182	p_ntp_delta(&(bp->org_timestamp), &(bp->rec_timestamp));
183
184	fputs("\n\t    Originator - Transmit Timestamp: ", stdout);
185	p_ntp_delta(&(bp->org_timestamp), &(bp->xmt_timestamp));
186
187	if ( (sizeof(struct ntpdata) - length) == 16) { 	/* Optional: key-id */
188		TCHECK(bp->key_id);
189		printf("\n\tKey id: %u", bp->key_id);
190	} else if ( (sizeof(struct ntpdata) - length) == 0) { 	/* Optional: key-id + authentication */
191		TCHECK(bp->key_id);
192		printf("\n\tKey id: %u", bp->key_id);
193		TCHECK2(bp->message_digest, sizeof (bp->message_digest));
194                printf("\n\tAuthentication: %08x%08x%08x%08x",
195        		       EXTRACT_32BITS(bp->message_digest),
196		               EXTRACT_32BITS(bp->message_digest + 4),
197		               EXTRACT_32BITS(bp->message_digest + 8),
198		               EXTRACT_32BITS(bp->message_digest + 12));
199        }
200	return;
201
202trunc:
203	fputs(" [|ntp]", stdout);
204}
205
206static void
207p_sfix(register const struct s_fixedpt *sfp)
208{
209	register int i;
210	register int f;
211	register float ff;
212
213	i = EXTRACT_16BITS(&sfp->int_part);
214	f = EXTRACT_16BITS(&sfp->fraction);
215	ff = f / 65536.0;	/* shift radix point by 16 bits */
216	f = ff * 1000000.0;	/* Treat fraction as parts per million */
217	printf("%d.%06d", i, f);
218}
219
220#define	FMAXINT	(4294967296.0)	/* floating point rep. of MAXINT */
221
222static void
223p_ntp_time(register const struct l_fixedpt *lfp)
224{
225	register int32_t i;
226	register u_int32_t uf;
227	register u_int32_t f;
228	register float ff;
229
230	i = EXTRACT_32BITS(&lfp->int_part);
231	uf = EXTRACT_32BITS(&lfp->fraction);
232	ff = uf;
233	if (ff < 0.0)		/* some compilers are buggy */
234		ff += FMAXINT;
235	ff = ff / FMAXINT;	/* shift radix point by 32 bits */
236	f = ff * 1000000000.0;	/* treat fraction as parts per billion */
237	printf("%u.%09d", i, f);
238
239#ifdef HAVE_STRFTIME
240	/*
241	 * print the time in human-readable format.
242	 */
243	if (i) {
244	    time_t seconds = i - JAN_1970;
245	    struct tm *tm;
246	    char time_buf[128];
247
248	    tm = localtime(&seconds);
249	    strftime(time_buf, sizeof (time_buf), "%Y/%m/%d %H:%M:%S", tm);
250	    printf (" (%s)", time_buf);
251	}
252#endif
253}
254
255/* Prints time difference between *lfp and *olfp */
256static void
257p_ntp_delta(register const struct l_fixedpt *olfp,
258	    register const struct l_fixedpt *lfp)
259{
260	register int32_t i;
261	register u_int32_t u, uf;
262	register u_int32_t ou, ouf;
263	register u_int32_t f;
264	register float ff;
265	int signbit;
266
267	u = EXTRACT_32BITS(&lfp->int_part);
268	ou = EXTRACT_32BITS(&olfp->int_part);
269	uf = EXTRACT_32BITS(&lfp->fraction);
270	ouf = EXTRACT_32BITS(&olfp->fraction);
271	if (ou == 0 && ouf == 0) {
272		p_ntp_time(lfp);
273		return;
274	}
275
276	i = u - ou;
277
278	if (i > 0) {		/* new is definitely greater than old */
279		signbit = 0;
280		f = uf - ouf;
281		if (ouf > uf)	/* must borrow from high-order bits */
282			i -= 1;
283	} else if (i < 0) {	/* new is definitely less than old */
284		signbit = 1;
285		f = ouf - uf;
286		if (uf > ouf)	/* must carry into the high-order bits */
287			i += 1;
288		i = -i;
289	} else {		/* int_part is zero */
290		if (uf > ouf) {
291			signbit = 0;
292			f = uf - ouf;
293		} else {
294			signbit = 1;
295			f = ouf - uf;
296		}
297	}
298
299	ff = f;
300	if (ff < 0.0)		/* some compilers are buggy */
301		ff += FMAXINT;
302	ff = ff / FMAXINT;	/* shift radix point by 32 bits */
303	f = ff * 1000000000.0;	/* treat fraction as parts per billion */
304	if (signbit)
305		putchar('-');
306	else
307		putchar('+');
308	printf("%d.%09d", i, f);
309}
310
311