xref: /freebsd/contrib/tcpdump/print-ntp.c (revision 4c8945a06b01a5c8122cdeb402af36bb46a06acc)
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
29 static 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 
53 static void p_sfix(const struct s_fixedpt *);
54 static void p_ntp_time(const struct l_fixedpt *);
55 static void p_ntp_delta(const struct l_fixedpt *, const struct l_fixedpt *);
56 
57 static 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 
69 static 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 
77 static struct tok ntp_stratum_values[] = {
78 	{ UNSPECIFIED,	"unspecified" },
79 	{ PRIM_REF, 	"primary reference" },
80 	{ 0, NULL }
81 };
82 
83 /*
84  * Print ntp requests
85  */
86 void
87 ntp_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 %us", 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 
202 trunc:
203 	fputs(" [|ntp]", stdout);
204 }
205 
206 static void
207 p_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 
222 static void
223 p_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 */
256 static void
257 p_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