xref: /freebsd/contrib/tcpdump/print-ntp.c (revision 6b3455a7665208c366849f0b2b3bc916fb97516e)
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 1.37.2.2 2003/11/16 08:51:36 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 /*
58  * Print ntp requests
59  */
60 void
61 ntp_print(register const u_char *cp, u_int length)
62 {
63 	register const struct ntpdata *bp;
64 	int mode, version, leapind;
65 
66 	bp = (struct ntpdata *)cp;
67 	/* Note funny sized packets */
68 	if (length != sizeof(struct ntpdata))
69 		(void)printf(" [len=%d]", length);
70 
71 	TCHECK(bp->status);
72 
73 	version = (int)(bp->status & VERSIONMASK) >> 3;
74 	printf("NTPv%d", version);
75 
76 	leapind = bp->status & LEAPMASK;
77 	switch (leapind) {
78 
79 	case NO_WARNING:
80 		break;
81 
82 	case PLUS_SEC:
83 		fputs(" +1s", stdout);
84 		break;
85 
86 	case MINUS_SEC:
87 		fputs(" -1s", stdout);
88 		break;
89 	}
90 
91 	mode = bp->status & MODEMASK;
92 	switch (mode) {
93 
94 	case MODE_UNSPEC:	/* unspecified */
95 		fputs(" unspec", stdout);
96 		break;
97 
98 	case MODE_SYM_ACT:	/* symmetric active */
99 		fputs(" sym_act", stdout);
100 		break;
101 
102 	case MODE_SYM_PAS:	/* symmetric passive */
103 		fputs(" sym_pas", stdout);
104 		break;
105 
106 	case MODE_CLIENT:	/* client */
107 		fputs(" client", stdout);
108 		break;
109 
110 	case MODE_SERVER:	/* server */
111 		fputs(" server", stdout);
112 		break;
113 
114 	case MODE_BROADCAST:	/* broadcast */
115 		fputs(" bcast", stdout);
116 		break;
117 
118 	case MODE_RES1:		/* reserved */
119 		fputs(" res1", stdout);
120 		break;
121 
122 	case MODE_RES2:		/* reserved */
123 		fputs(" res2", stdout);
124 		break;
125 
126 	}
127 
128 	TCHECK(bp->stratum);
129 	printf(", strat %d", bp->stratum);
130 
131 	TCHECK(bp->ppoll);
132 	printf(", poll %d", bp->ppoll);
133 
134 	/* Can't TCHECK bp->precision bitfield so bp->distance + 0 instead */
135 	TCHECK2(bp->distance, 0);
136 	printf(", prec %d", bp->precision);
137 
138 	if (!vflag)
139 		return;
140 
141 	TCHECK(bp->distance);
142 	fputs(" dist ", stdout);
143 	p_sfix(&bp->distance);
144 
145 	TCHECK(bp->dispersion);
146 	fputs(", disp ", stdout);
147 	p_sfix(&bp->dispersion);
148 
149 	TCHECK(bp->refid);
150 	fputs(", ref ", stdout);
151 	/* Interpretation depends on stratum */
152 	switch (bp->stratum) {
153 
154 	case UNSPECIFIED:
155 		printf("(unspec)");
156 		break;
157 
158 	case PRIM_REF:
159 		fn_printn((u_char *)&(bp->refid), 4, NULL);
160 		break;
161 
162 	case INFO_QUERY:
163 		printf("%s INFO_QUERY", ipaddr_string(&(bp->refid)));
164 		/* this doesn't have more content */
165 		return;
166 
167 	case INFO_REPLY:
168 		printf("%s INFO_REPLY", ipaddr_string(&(bp->refid)));
169 		/* this is too complex to be worth printing */
170 		return;
171 
172 	default:
173 		printf("%s", ipaddr_string(&(bp->refid)));
174 		break;
175 	}
176 
177 	TCHECK(bp->reftime);
178 	putchar('@');
179 	p_ntp_time(&(bp->reftime));
180 
181 	TCHECK(bp->org);
182 	fputs(" orig ", stdout);
183 	p_ntp_time(&(bp->org));
184 
185 	TCHECK(bp->rec);
186 	fputs(" rec ", stdout);
187 	p_ntp_delta(&(bp->org), &(bp->rec));
188 
189 	TCHECK(bp->xmt);
190 	fputs(" xmt ", stdout);
191 	p_ntp_delta(&(bp->org), &(bp->xmt));
192 
193 	return;
194 
195 trunc:
196 	fputs(" [|ntp]", stdout);
197 }
198 
199 static void
200 p_sfix(register const struct s_fixedpt *sfp)
201 {
202 	register int i;
203 	register int f;
204 	register float ff;
205 
206 	i = EXTRACT_16BITS(&sfp->int_part);
207 	f = EXTRACT_16BITS(&sfp->fraction);
208 	ff = f / 65536.0;	/* shift radix point by 16 bits */
209 	f = ff * 1000000.0;	/* Treat fraction as parts per million */
210 	printf("%d.%06d", i, f);
211 }
212 
213 #define	FMAXINT	(4294967296.0)	/* floating point rep. of MAXINT */
214 
215 static void
216 p_ntp_time(register const struct l_fixedpt *lfp)
217 {
218 	register int32_t i;
219 	register u_int32_t uf;
220 	register u_int32_t f;
221 	register float ff;
222 
223 	i = EXTRACT_32BITS(&lfp->int_part);
224 	uf = EXTRACT_32BITS(&lfp->fraction);
225 	ff = uf;
226 	if (ff < 0.0)		/* some compilers are buggy */
227 		ff += FMAXINT;
228 	ff = ff / FMAXINT;	/* shift radix point by 32 bits */
229 	f = ff * 1000000000.0;	/* treat fraction as parts per billion */
230 	printf("%u.%09d", i, f);
231 
232 #ifdef HAVE_STRFTIME
233 	/*
234 	 * For extra verbosity, print the time in human-readable format.
235 	 */
236 	if (vflag > 1 && i) {
237 	    time_t seconds = i - JAN_1970;
238 	    struct tm *tm;
239 	    char time_buf[128];
240 
241 	    tm = localtime(&seconds);
242 	    strftime(time_buf, sizeof (time_buf), "%Y/%m/%d %H:%M:%S", tm);
243 	    printf (" (%s)", time_buf);
244 	}
245 #endif
246 }
247 
248 /* Prints time difference between *lfp and *olfp */
249 static void
250 p_ntp_delta(register const struct l_fixedpt *olfp,
251 	    register const struct l_fixedpt *lfp)
252 {
253 	register int32_t i;
254 	register u_int32_t u, uf;
255 	register u_int32_t ou, ouf;
256 	register u_int32_t f;
257 	register float ff;
258 	int signbit;
259 
260 	u = EXTRACT_32BITS(&lfp->int_part);
261 	ou = EXTRACT_32BITS(&olfp->int_part);
262 	uf = EXTRACT_32BITS(&lfp->fraction);
263 	ouf = EXTRACT_32BITS(&olfp->fraction);
264 	if (ou == 0 && ouf == 0) {
265 		p_ntp_time(lfp);
266 		return;
267 	}
268 
269 	i = u - ou;
270 
271 	if (i > 0) {		/* new is definitely greater than old */
272 		signbit = 0;
273 		f = uf - ouf;
274 		if (ouf > uf)	/* must borrow from high-order bits */
275 			i -= 1;
276 	} else if (i < 0) {	/* new is definitely less than old */
277 		signbit = 1;
278 		f = ouf - uf;
279 		if (uf > ouf)	/* must carry into the high-order bits */
280 			i += 1;
281 		i = -i;
282 	} else {		/* int_part is zero */
283 		if (uf > ouf) {
284 			signbit = 0;
285 			f = uf - ouf;
286 		} else {
287 			signbit = 1;
288 			f = ouf - uf;
289 		}
290 	}
291 
292 	ff = f;
293 	if (ff < 0.0)		/* some compilers are buggy */
294 		ff += FMAXINT;
295 	ff = ff / FMAXINT;	/* shift radix point by 32 bits */
296 	f = ff * 1000000000.0;	/* treat fraction as parts per billion */
297 	if (signbit)
298 		putchar('-');
299 	else
300 		putchar('+');
301 	printf("%d.%09d", i, f);
302 }
303 
304