xref: /freebsd/contrib/tcpdump/print-ntp.c (revision 4cf49a43559ed9fdad601bdcccd2c55963008675)
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
27 static const char rcsid[] =
28     "@(#) $Header: print-ntp.c,v 1.26 97/06/13 12:56:37 leres Exp $ (LBL)";
29 #endif
30 
31 #include <sys/param.h>
32 #include <sys/time.h>
33 #include <sys/socket.h>
34 
35 #if __STDC__
36 struct mbuf;
37 struct rtentry;
38 #endif
39 #include <net/if.h>
40 
41 #include <netinet/in.h>
42 #include <net/ethernet.h>
43 
44 #include <ctype.h>
45 #include <stdio.h>
46 #include <string.h>
47 
48 #include "interface.h"
49 #include "addrtoname.h"
50 #ifdef MODEMASK
51 #undef MODEMASK					/* Solaris sucks */
52 #endif
53 #include "ntp.h"
54 
55 static void p_sfix(const struct s_fixedpt *);
56 static void p_ntp_time(const struct l_fixedpt *);
57 static void p_ntp_delta(const struct l_fixedpt *, const struct l_fixedpt *);
58 
59 /*
60  * Print ntp requests
61  */
62 void
63 ntp_print(register const u_char *cp, u_int length)
64 {
65 	register const struct ntpdata *bp;
66 	int mode, version, leapind;
67 	static char rclock[5];
68 
69 	bp = (struct ntpdata *)cp;
70 	/* Note funny sized packets */
71 	if (length != sizeof(struct ntpdata))
72 		(void)printf(" [len=%d]", length);
73 
74 	TCHECK(bp->status);
75 
76 	version = (int)(bp->status & VERSIONMASK) >> 3;
77 	printf(" v%d", version);
78 
79 	leapind = bp->status & LEAPMASK;
80 	switch (leapind) {
81 
82 	case NO_WARNING:
83 		break;
84 
85 	case PLUS_SEC:
86 		fputs(" +1s", stdout);
87 		break;
88 
89 	case MINUS_SEC:
90 		fputs(" -1s", stdout);
91 		break;
92 	}
93 
94 	mode = bp->status & MODEMASK;
95 	switch (mode) {
96 
97 	case MODE_UNSPEC:	/* unspecified */
98 		fputs(" unspec", stdout);
99 		break;
100 
101 	case MODE_SYM_ACT:	/* symmetric active */
102 		fputs(" sym_act", stdout);
103 		break;
104 
105 	case MODE_SYM_PAS:	/* symmetric passive */
106 		fputs(" sym_pas", stdout);
107 		break;
108 
109 	case MODE_CLIENT:	/* client */
110 		fputs(" client", stdout);
111 		break;
112 
113 	case MODE_SERVER:	/* server */
114 		fputs(" server", stdout);
115 		break;
116 
117 	case MODE_BROADCAST:	/* broadcast */
118 		fputs(" bcast", stdout);
119 		break;
120 
121 	case MODE_RES1:		/* reserved */
122 		fputs(" res1", stdout);
123 		break;
124 
125 	case MODE_RES2:		/* reserved */
126 		fputs(" res2", stdout);
127 		break;
128 
129 	}
130 
131 	TCHECK(bp->stratum);
132 	printf(" strat %d", bp->stratum);
133 
134 	TCHECK(bp->ppoll);
135 	printf(" poll %d", bp->ppoll);
136 
137 	/* Can't TCHECK bp->precision bitfield so bp->distance + 0 instead */
138 	TCHECK2(bp->distance, 0);
139 	printf(" prec %d", bp->precision);
140 
141 	if (!vflag)
142 		return;
143 
144 	TCHECK(bp->distance);
145 	fputs(" dist ", stdout);
146 	p_sfix(&bp->distance);
147 
148 	TCHECK(bp->dispersion);
149 	fputs(" disp ", stdout);
150 	p_sfix(&bp->dispersion);
151 
152 	TCHECK(bp->refid);
153 	fputs(" ref ", stdout);
154 	/* Interpretation depends on stratum */
155 	switch (bp->stratum) {
156 
157 	case UNSPECIFIED:
158 		printf("(unspec)");
159 		break;
160 
161 	case PRIM_REF:
162 		strncpy(rclock, (char *)&(bp->refid), 4);
163 		rclock[4] = '\0';
164 		fputs(rclock, stdout);
165 		break;
166 
167 	case INFO_QUERY:
168 		printf("%s INFO_QUERY", ipaddr_string(&(bp->refid)));
169 		/* this doesn't have more content */
170 		return;
171 
172 	case INFO_REPLY:
173 		printf("%s INFO_REPLY", ipaddr_string(&(bp->refid)));
174 		/* this is too complex to be worth printing */
175 		return;
176 
177 	default:
178 		printf("%s", ipaddr_string(&(bp->refid)));
179 		break;
180 	}
181 
182 	TCHECK(bp->reftime);
183 	putchar('@');
184 	p_ntp_time(&(bp->reftime));
185 
186 	TCHECK(bp->org);
187 	fputs(" orig ", stdout);
188 	p_ntp_time(&(bp->org));
189 
190 	TCHECK(bp->rec);
191 	fputs(" rec ", stdout);
192 	p_ntp_delta(&(bp->org), &(bp->rec));
193 
194 	TCHECK(bp->xmt);
195 	fputs(" xmt ", stdout);
196 	p_ntp_delta(&(bp->org), &(bp->xmt));
197 
198 	return;
199 
200 trunc:
201 	fputs(" [|ntp]", stdout);
202 }
203 
204 static void
205 p_sfix(register const struct s_fixedpt *sfp)
206 {
207 	register int i;
208 	register int f;
209 	register float ff;
210 
211 	i = ntohs(sfp->int_part);
212 	f = ntohs(sfp->fraction);
213 	ff = f / 65536.0;	/* shift radix point by 16 bits */
214 	f = ff * 1000000.0;	/* Treat fraction as parts per million */
215 	printf("%d.%06d", i, f);
216 }
217 
218 #define	FMAXINT	(4294967296.0)	/* floating point rep. of MAXINT */
219 
220 static void
221 p_ntp_time(register const struct l_fixedpt *lfp)
222 {
223 	register int32_t i;
224 	register u_int32_t uf;
225 	register u_int32_t f;
226 	register float ff;
227 
228 	i = ntohl(lfp->int_part);
229 	uf = ntohl(lfp->fraction);
230 	ff = uf;
231 	if (ff < 0.0)		/* some compilers are buggy */
232 		ff += FMAXINT;
233 	ff = ff / FMAXINT;	/* shift radix point by 32 bits */
234 	f = ff * 1000000000.0;	/* treat fraction as parts per billion */
235 	printf("%u.%09d", i, f);
236 }
237 
238 /* Prints time difference between *lfp and *olfp */
239 static void
240 p_ntp_delta(register const struct l_fixedpt *olfp,
241 	    register const struct l_fixedpt *lfp)
242 {
243 	register int32_t i;
244 	register u_int32_t uf;
245 	register u_int32_t ouf;
246 	register u_int32_t f;
247 	register float ff;
248 	int signbit;
249 
250 	i = ntohl(lfp->int_part) - ntohl(olfp->int_part);
251 
252 	uf = ntohl(lfp->fraction);
253 	ouf = ntohl(olfp->fraction);
254 
255 	if (i > 0) {		/* new is definitely greater than old */
256 		signbit = 0;
257 		f = uf - ouf;
258 		if (ouf > uf)	/* must borrow from high-order bits */
259 			i -= 1;
260 	} else if (i < 0) {	/* new is definitely less than old */
261 		signbit = 1;
262 		f = ouf - uf;
263 		if (uf > ouf)	/* must carry into the high-order bits */
264 			i += 1;
265 		i = -i;
266 	} else {		/* int_part is zero */
267 		if (uf > ouf) {
268 			signbit = 0;
269 			f = uf - ouf;
270 		} else {
271 			signbit = 1;
272 			f = ouf - uf;
273 		}
274 	}
275 
276 	ff = f;
277 	if (ff < 0.0)		/* some compilers are buggy */
278 		ff += FMAXINT;
279 	ff = ff / FMAXINT;	/* shift radix point by 32 bits */
280 	f = ff * 1000000000.0;	/* treat fraction as parts per billion */
281 	if (signbit)
282 		putchar('-');
283 	else
284 		putchar('+');
285 	printf("%d.%09d", i, f);
286 }
287