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 1.41.2.1 2005/05/06 07:57:18 guy 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 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 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
75/*
76 * Print ntp requests
77 */
78void
79ntp_print(register const u_char *cp, u_int length)
80{
81	register const struct ntpdata *bp;
82	int mode, version, leapind;
83
84	bp = (struct ntpdata *)cp;
85
86	TCHECK(bp->status);
87
88	version = (int)(bp->status & VERSIONMASK) >> 3;
89	printf("NTPv%d", version);
90
91	mode = bp->status & MODEMASK;
92        if (!vflag) {
93            printf (", %s, length %u",
94                    tok2str(ntp_mode_values, "Unknown mode", mode),
95                    length);
96            return;
97        }
98
99        printf (", length %u\n\t%s",
100                length,
101                tok2str(ntp_mode_values, "Unknown mode", mode));
102
103	leapind = bp->status & LEAPMASK;
104        printf (", Leap indicator: %s (%u)",
105                tok2str(ntp_leapind_values, "Unknown", leapind),
106                leapind);
107
108	TCHECK(bp->stratum);
109	printf(", Stratum %u", bp->stratum);
110
111	TCHECK(bp->ppoll);
112	printf(", poll %us", bp->ppoll);
113
114	/* Can't TCHECK bp->precision bitfield so bp->distance + 0 instead */
115	TCHECK2(bp->root_delay, 0);
116	printf(", precision %d", bp->precision);
117
118	TCHECK(bp->root_delay);
119	fputs("\n\tRoot Delay: ", stdout);
120	p_sfix(&bp->root_delay);
121
122	TCHECK(bp->root_dispersion);
123	fputs(", Root dispersion: ", stdout);
124	p_sfix(&bp->root_dispersion);
125
126	TCHECK(bp->refid);
127	fputs(", Reference-ID: ", stdout);
128	/* Interpretation depends on stratum */
129	switch (bp->stratum) {
130
131	case UNSPECIFIED:
132		printf("(unspec)");
133		break;
134
135	case PRIM_REF:
136		if (fn_printn((u_char *)&(bp->refid), 4, snapend))
137			goto trunc;
138		break;
139
140	case INFO_QUERY:
141		printf("%s INFO_QUERY", ipaddr_string(&(bp->refid)));
142		/* this doesn't have more content */
143		return;
144
145	case INFO_REPLY:
146		printf("%s INFO_REPLY", ipaddr_string(&(bp->refid)));
147		/* this is too complex to be worth printing */
148		return;
149
150	default:
151		printf("%s", ipaddr_string(&(bp->refid)));
152		break;
153	}
154
155	TCHECK(bp->ref_timestamp);
156	fputs("\n\t  Reference Timestamp:  ", stdout);
157	p_ntp_time(&(bp->ref_timestamp));
158
159	TCHECK(bp->org_timestamp);
160	fputs("\n\t  Originator Timestamp: ", stdout);
161	p_ntp_time(&(bp->org_timestamp));
162
163	TCHECK(bp->rec_timestamp);
164	fputs("\n\t  Receive Timestamp:    ", stdout);
165	p_ntp_time(&(bp->rec_timestamp));
166
167	TCHECK(bp->xmt_timestamp);
168	fputs("\n\t  Transmit Timestamp:   ", stdout);
169	p_ntp_time(&(bp->xmt_timestamp));
170
171	fputs("\n\t    Originator - Receive Timestamp:  ", stdout);
172	p_ntp_delta(&(bp->org_timestamp), &(bp->rec_timestamp));
173
174	fputs("\n\t    Originator - Transmit Timestamp: ", stdout);
175	p_ntp_delta(&(bp->org_timestamp), &(bp->xmt_timestamp));
176
177        /* FIXME key-id, authentication */
178
179	return;
180
181trunc:
182	fputs(" [|ntp]", stdout);
183}
184
185static void
186p_sfix(register const struct s_fixedpt *sfp)
187{
188	register int i;
189	register int f;
190	register float ff;
191
192	i = EXTRACT_16BITS(&sfp->int_part);
193	f = EXTRACT_16BITS(&sfp->fraction);
194	ff = f / 65536.0;	/* shift radix point by 16 bits */
195	f = ff * 1000000.0;	/* Treat fraction as parts per million */
196	printf("%d.%06d", i, f);
197}
198
199#define	FMAXINT	(4294967296.0)	/* floating point rep. of MAXINT */
200
201static void
202p_ntp_time(register const struct l_fixedpt *lfp)
203{
204	register int32_t i;
205	register u_int32_t uf;
206	register u_int32_t f;
207	register float ff;
208
209	i = EXTRACT_32BITS(&lfp->int_part);
210	uf = EXTRACT_32BITS(&lfp->fraction);
211	ff = uf;
212	if (ff < 0.0)		/* some compilers are buggy */
213		ff += FMAXINT;
214	ff = ff / FMAXINT;	/* shift radix point by 32 bits */
215	f = ff * 1000000000.0;	/* treat fraction as parts per billion */
216	printf("%u.%09d", i, f);
217
218#ifdef HAVE_STRFTIME
219	/*
220	 * print the time in human-readable format.
221	 */
222	if (i) {
223	    time_t seconds = i - JAN_1970;
224	    struct tm *tm;
225	    char time_buf[128];
226
227	    tm = localtime(&seconds);
228	    strftime(time_buf, sizeof (time_buf), "%Y/%m/%d %H:%M:%S", tm);
229	    printf (" (%s)", time_buf);
230	}
231#endif
232}
233
234/* Prints time difference between *lfp and *olfp */
235static void
236p_ntp_delta(register const struct l_fixedpt *olfp,
237	    register const struct l_fixedpt *lfp)
238{
239	register int32_t i;
240	register u_int32_t u, uf;
241	register u_int32_t ou, ouf;
242	register u_int32_t f;
243	register float ff;
244	int signbit;
245
246	u = EXTRACT_32BITS(&lfp->int_part);
247	ou = EXTRACT_32BITS(&olfp->int_part);
248	uf = EXTRACT_32BITS(&lfp->fraction);
249	ouf = EXTRACT_32BITS(&olfp->fraction);
250	if (ou == 0 && ouf == 0) {
251		p_ntp_time(lfp);
252		return;
253	}
254
255	i = u - ou;
256
257	if (i > 0) {		/* new is definitely greater than old */
258		signbit = 0;
259		f = uf - ouf;
260		if (ouf > uf)	/* must borrow from high-order bits */
261			i -= 1;
262	} else if (i < 0) {	/* new is definitely less than old */
263		signbit = 1;
264		f = ouf - uf;
265		if (uf > ouf)	/* must carry into the high-order bits */
266			i += 1;
267		i = -i;
268	} else {		/* int_part is zero */
269		if (uf > ouf) {
270			signbit = 0;
271			f = uf - ouf;
272		} else {
273			signbit = 1;
274			f = ouf - uf;
275		}
276	}
277
278	ff = f;
279	if (ff < 0.0)		/* some compilers are buggy */
280		ff += FMAXINT;
281	ff = ff / FMAXINT;	/* shift radix point by 32 bits */
282	f = ff * 1000000000.0;	/* treat fraction as parts per billion */
283	if (signbit)
284		putchar('-');
285	else
286		putchar('+');
287	printf("%d.%09d", i, f);
288}
289
290