xref: /freebsd/contrib/tcpdump/print-ntp.c (revision daf1cffce2e07931f27c6c6998652e90df6ba87e)
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[] =
30     "@(#) $Header: /tcpdump/master/tcpdump/print-ntp.c,v 1.27 1999/11/21 09:36:57 fenner Exp $ (LBL)";
31 #endif
32 
33 #ifdef HAVE_CONFIG_H
34 #include "config.h"
35 #endif
36 
37 #include <sys/param.h>
38 #include <sys/time.h>
39 #include <sys/socket.h>
40 
41 #if __STDC__
42 struct mbuf;
43 struct rtentry;
44 #endif
45 #include <net/if.h>
46 
47 #include <netinet/in.h>
48 #include <net/ethernet.h>
49 
50 #include <ctype.h>
51 #include <stdio.h>
52 #include <string.h>
53 
54 #include "interface.h"
55 #include "addrtoname.h"
56 #ifdef MODEMASK
57 #undef MODEMASK					/* Solaris sucks */
58 #endif
59 #include "ntp.h"
60 
61 static void p_sfix(const struct s_fixedpt *);
62 static void p_ntp_time(const struct l_fixedpt *);
63 static void p_ntp_delta(const struct l_fixedpt *, const struct l_fixedpt *);
64 
65 /*
66  * Print ntp requests
67  */
68 void
69 ntp_print(register const u_char *cp, u_int length)
70 {
71 	register const struct ntpdata *bp;
72 	int mode, version, leapind;
73 	static char rclock[5];
74 
75 	bp = (struct ntpdata *)cp;
76 	/* Note funny sized packets */
77 	if (length != sizeof(struct ntpdata))
78 		(void)printf(" [len=%d]", length);
79 
80 	TCHECK(bp->status);
81 
82 	version = (int)(bp->status & VERSIONMASK) >> 3;
83 	printf(" v%d", version);
84 
85 	leapind = bp->status & LEAPMASK;
86 	switch (leapind) {
87 
88 	case NO_WARNING:
89 		break;
90 
91 	case PLUS_SEC:
92 		fputs(" +1s", stdout);
93 		break;
94 
95 	case MINUS_SEC:
96 		fputs(" -1s", stdout);
97 		break;
98 	}
99 
100 	mode = bp->status & MODEMASK;
101 	switch (mode) {
102 
103 	case MODE_UNSPEC:	/* unspecified */
104 		fputs(" unspec", stdout);
105 		break;
106 
107 	case MODE_SYM_ACT:	/* symmetric active */
108 		fputs(" sym_act", stdout);
109 		break;
110 
111 	case MODE_SYM_PAS:	/* symmetric passive */
112 		fputs(" sym_pas", stdout);
113 		break;
114 
115 	case MODE_CLIENT:	/* client */
116 		fputs(" client", stdout);
117 		break;
118 
119 	case MODE_SERVER:	/* server */
120 		fputs(" server", stdout);
121 		break;
122 
123 	case MODE_BROADCAST:	/* broadcast */
124 		fputs(" bcast", stdout);
125 		break;
126 
127 	case MODE_RES1:		/* reserved */
128 		fputs(" res1", stdout);
129 		break;
130 
131 	case MODE_RES2:		/* reserved */
132 		fputs(" res2", stdout);
133 		break;
134 
135 	}
136 
137 	TCHECK(bp->stratum);
138 	printf(" strat %d", bp->stratum);
139 
140 	TCHECK(bp->ppoll);
141 	printf(" poll %d", bp->ppoll);
142 
143 	/* Can't TCHECK bp->precision bitfield so bp->distance + 0 instead */
144 	TCHECK2(bp->distance, 0);
145 	printf(" prec %d", bp->precision);
146 
147 	if (!vflag)
148 		return;
149 
150 	TCHECK(bp->distance);
151 	fputs(" dist ", stdout);
152 	p_sfix(&bp->distance);
153 
154 	TCHECK(bp->dispersion);
155 	fputs(" disp ", stdout);
156 	p_sfix(&bp->dispersion);
157 
158 	TCHECK(bp->refid);
159 	fputs(" ref ", stdout);
160 	/* Interpretation depends on stratum */
161 	switch (bp->stratum) {
162 
163 	case UNSPECIFIED:
164 		printf("(unspec)");
165 		break;
166 
167 	case PRIM_REF:
168 		strncpy(rclock, (char *)&(bp->refid), 4);
169 		rclock[4] = '\0';
170 		fputs(rclock, stdout);
171 		break;
172 
173 	case INFO_QUERY:
174 		printf("%s INFO_QUERY", ipaddr_string(&(bp->refid)));
175 		/* this doesn't have more content */
176 		return;
177 
178 	case INFO_REPLY:
179 		printf("%s INFO_REPLY", ipaddr_string(&(bp->refid)));
180 		/* this is too complex to be worth printing */
181 		return;
182 
183 	default:
184 		printf("%s", ipaddr_string(&(bp->refid)));
185 		break;
186 	}
187 
188 	TCHECK(bp->reftime);
189 	putchar('@');
190 	p_ntp_time(&(bp->reftime));
191 
192 	TCHECK(bp->org);
193 	fputs(" orig ", stdout);
194 	p_ntp_time(&(bp->org));
195 
196 	TCHECK(bp->rec);
197 	fputs(" rec ", stdout);
198 	p_ntp_delta(&(bp->org), &(bp->rec));
199 
200 	TCHECK(bp->xmt);
201 	fputs(" xmt ", stdout);
202 	p_ntp_delta(&(bp->org), &(bp->xmt));
203 
204 	return;
205 
206 trunc:
207 	fputs(" [|ntp]", stdout);
208 }
209 
210 static void
211 p_sfix(register const struct s_fixedpt *sfp)
212 {
213 	register int i;
214 	register int f;
215 	register float ff;
216 
217 	i = ntohs(sfp->int_part);
218 	f = ntohs(sfp->fraction);
219 	ff = f / 65536.0;	/* shift radix point by 16 bits */
220 	f = ff * 1000000.0;	/* Treat fraction as parts per million */
221 	printf("%d.%06d", i, f);
222 }
223 
224 #define	FMAXINT	(4294967296.0)	/* floating point rep. of MAXINT */
225 
226 static void
227 p_ntp_time(register const struct l_fixedpt *lfp)
228 {
229 	register int32_t i;
230 	register u_int32_t uf;
231 	register u_int32_t f;
232 	register float ff;
233 
234 	i = ntohl(lfp->int_part);
235 	uf = ntohl(lfp->fraction);
236 	ff = uf;
237 	if (ff < 0.0)		/* some compilers are buggy */
238 		ff += FMAXINT;
239 	ff = ff / FMAXINT;	/* shift radix point by 32 bits */
240 	f = ff * 1000000000.0;	/* treat fraction as parts per billion */
241 	printf("%u.%09d", i, f);
242 }
243 
244 /* Prints time difference between *lfp and *olfp */
245 static void
246 p_ntp_delta(register const struct l_fixedpt *olfp,
247 	    register const struct l_fixedpt *lfp)
248 {
249 	register int32_t i;
250 	register u_int32_t uf;
251 	register u_int32_t ouf;
252 	register u_int32_t f;
253 	register float ff;
254 	int signbit;
255 
256 	i = ntohl(lfp->int_part) - ntohl(olfp->int_part);
257 
258 	uf = ntohl(lfp->fraction);
259 	ouf = ntohl(olfp->fraction);
260 
261 	if (i > 0) {		/* new is definitely greater than old */
262 		signbit = 0;
263 		f = uf - ouf;
264 		if (ouf > uf)	/* must borrow from high-order bits */
265 			i -= 1;
266 	} else if (i < 0) {	/* new is definitely less than old */
267 		signbit = 1;
268 		f = ouf - uf;
269 		if (uf > ouf)	/* must carry into the high-order bits */
270 			i += 1;
271 		i = -i;
272 	} else {		/* int_part is zero */
273 		if (uf > ouf) {
274 			signbit = 0;
275 			f = uf - ouf;
276 		} else {
277 			signbit = 1;
278 			f = ouf - uf;
279 		}
280 	}
281 
282 	ff = f;
283 	if (ff < 0.0)		/* some compilers are buggy */
284 		ff += FMAXINT;
285 	ff = ff / FMAXINT;	/* shift radix point by 32 bits */
286 	f = ff * 1000000000.0;	/* treat fraction as parts per billion */
287 	if (signbit)
288 		putchar('-');
289 	else
290 		putchar('+');
291 	printf("%d.%09d", i, f);
292 }
293