xref: /freebsd/contrib/tcpdump/print-ntp.c (revision f0a75d274af375d15b97b830966b99a02b7db911)
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 1.41.2.1 2005/05/06 07:57:18 guy 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 /*
78  * Print ntp requests
79  */
80 void
81 ntp_print(register const u_char *cp, u_int length)
82 {
83 	register const struct ntpdata *bp;
84 	int mode, version, leapind;
85 
86 	bp = (struct ntpdata *)cp;
87 
88 	TCHECK(bp->status);
89 
90 	version = (int)(bp->status & VERSIONMASK) >> 3;
91 	printf("NTPv%d", version);
92 
93 	mode = bp->status & MODEMASK;
94         if (!vflag) {
95             printf (", %s, length %u",
96                     tok2str(ntp_mode_values, "Unknown mode", mode),
97                     length);
98             return;
99         }
100 
101         printf (", length %u\n\t%s",
102                 length,
103                 tok2str(ntp_mode_values, "Unknown mode", mode));
104 
105 	leapind = bp->status & LEAPMASK;
106         printf (", Leap indicator: %s (%u)",
107                 tok2str(ntp_leapind_values, "Unknown", leapind),
108                 leapind);
109 
110 	TCHECK(bp->stratum);
111 	printf(", Stratum %u", bp->stratum);
112 
113 	TCHECK(bp->ppoll);
114 	printf(", poll %us", bp->ppoll);
115 
116 	/* Can't TCHECK bp->precision bitfield so bp->distance + 0 instead */
117 	TCHECK2(bp->root_delay, 0);
118 	printf(", precision %d", bp->precision);
119 
120 	TCHECK(bp->root_delay);
121 	fputs("\n\tRoot Delay: ", stdout);
122 	p_sfix(&bp->root_delay);
123 
124 	TCHECK(bp->root_dispersion);
125 	fputs(", Root dispersion: ", stdout);
126 	p_sfix(&bp->root_dispersion);
127 
128 	TCHECK(bp->refid);
129 	fputs(", Reference-ID: ", stdout);
130 	/* Interpretation depends on stratum */
131 	switch (bp->stratum) {
132 
133 	case UNSPECIFIED:
134 		printf("(unspec)");
135 		break;
136 
137 	case PRIM_REF:
138 		if (fn_printn((u_char *)&(bp->refid), 4, snapend))
139 			goto trunc;
140 		break;
141 
142 	case INFO_QUERY:
143 		printf("%s INFO_QUERY", ipaddr_string(&(bp->refid)));
144 		/* this doesn't have more content */
145 		return;
146 
147 	case INFO_REPLY:
148 		printf("%s INFO_REPLY", ipaddr_string(&(bp->refid)));
149 		/* this is too complex to be worth printing */
150 		return;
151 
152 	default:
153 		printf("%s", ipaddr_string(&(bp->refid)));
154 		break;
155 	}
156 
157 	TCHECK(bp->ref_timestamp);
158 	fputs("\n\t  Reference Timestamp:  ", stdout);
159 	p_ntp_time(&(bp->ref_timestamp));
160 
161 	TCHECK(bp->org_timestamp);
162 	fputs("\n\t  Originator Timestamp: ", stdout);
163 	p_ntp_time(&(bp->org_timestamp));
164 
165 	TCHECK(bp->rec_timestamp);
166 	fputs("\n\t  Receive Timestamp:    ", stdout);
167 	p_ntp_time(&(bp->rec_timestamp));
168 
169 	TCHECK(bp->xmt_timestamp);
170 	fputs("\n\t  Transmit Timestamp:   ", stdout);
171 	p_ntp_time(&(bp->xmt_timestamp));
172 
173 	fputs("\n\t    Originator - Receive Timestamp:  ", stdout);
174 	p_ntp_delta(&(bp->org_timestamp), &(bp->rec_timestamp));
175 
176 	fputs("\n\t    Originator - Transmit Timestamp: ", stdout);
177 	p_ntp_delta(&(bp->org_timestamp), &(bp->xmt_timestamp));
178 
179         /* FIXME key-id, authentication */
180 
181 	return;
182 
183 trunc:
184 	fputs(" [|ntp]", stdout);
185 }
186 
187 static void
188 p_sfix(register const struct s_fixedpt *sfp)
189 {
190 	register int i;
191 	register int f;
192 	register float ff;
193 
194 	i = EXTRACT_16BITS(&sfp->int_part);
195 	f = EXTRACT_16BITS(&sfp->fraction);
196 	ff = f / 65536.0;	/* shift radix point by 16 bits */
197 	f = ff * 1000000.0;	/* Treat fraction as parts per million */
198 	printf("%d.%06d", i, f);
199 }
200 
201 #define	FMAXINT	(4294967296.0)	/* floating point rep. of MAXINT */
202 
203 static void
204 p_ntp_time(register const struct l_fixedpt *lfp)
205 {
206 	register int32_t i;
207 	register u_int32_t uf;
208 	register u_int32_t f;
209 	register float ff;
210 
211 	i = EXTRACT_32BITS(&lfp->int_part);
212 	uf = EXTRACT_32BITS(&lfp->fraction);
213 	ff = uf;
214 	if (ff < 0.0)		/* some compilers are buggy */
215 		ff += FMAXINT;
216 	ff = ff / FMAXINT;	/* shift radix point by 32 bits */
217 	f = ff * 1000000000.0;	/* treat fraction as parts per billion */
218 	printf("%u.%09d", i, f);
219 
220 #ifdef HAVE_STRFTIME
221 	/*
222 	 * print the time in human-readable format.
223 	 */
224 	if (i) {
225 	    time_t seconds = i - JAN_1970;
226 	    struct tm *tm;
227 	    char time_buf[128];
228 
229 	    tm = localtime(&seconds);
230 	    strftime(time_buf, sizeof (time_buf), "%Y/%m/%d %H:%M:%S", tm);
231 	    printf (" (%s)", time_buf);
232 	}
233 #endif
234 }
235 
236 /* Prints time difference between *lfp and *olfp */
237 static void
238 p_ntp_delta(register const struct l_fixedpt *olfp,
239 	    register const struct l_fixedpt *lfp)
240 {
241 	register int32_t i;
242 	register u_int32_t u, uf;
243 	register u_int32_t ou, ouf;
244 	register u_int32_t f;
245 	register float ff;
246 	int signbit;
247 
248 	u = EXTRACT_32BITS(&lfp->int_part);
249 	ou = EXTRACT_32BITS(&olfp->int_part);
250 	uf = EXTRACT_32BITS(&lfp->fraction);
251 	ouf = EXTRACT_32BITS(&olfp->fraction);
252 	if (ou == 0 && ouf == 0) {
253 		p_ntp_time(lfp);
254 		return;
255 	}
256 
257 	i = u - ou;
258 
259 	if (i > 0) {		/* new is definitely greater than old */
260 		signbit = 0;
261 		f = uf - ouf;
262 		if (ouf > uf)	/* must borrow from high-order bits */
263 			i -= 1;
264 	} else if (i < 0) {	/* new is definitely less than old */
265 		signbit = 1;
266 		f = ouf - uf;
267 		if (uf > ouf)	/* must carry into the high-order bits */
268 			i += 1;
269 		i = -i;
270 	} else {		/* int_part is zero */
271 		if (uf > ouf) {
272 			signbit = 0;
273 			f = uf - ouf;
274 		} else {
275 			signbit = 1;
276 			f = ouf - uf;
277 		}
278 	}
279 
280 	ff = f;
281 	if (ff < 0.0)		/* some compilers are buggy */
282 		ff += FMAXINT;
283 	ff = ff / FMAXINT;	/* shift radix point by 32 bits */
284 	f = ff * 1000000000.0;	/* treat fraction as parts per billion */
285 	if (signbit)
286 		putchar('-');
287 	else
288 		putchar('+');
289 	printf("%d.%09d", i, f);
290 }
291 
292