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      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[] _U_ =
     28     "@(#) $Header: /tcpdump/master/tcpdump/print-ntp.c,v 1.41.2.1 2005/05/06 07:57:18 guy Exp $ (LBL)";
     29 #endif
     30 
     31 #ifdef HAVE_CONFIG_H
     32 #include "config.h"
     33 #endif
     34 
     35 #include <tcpdump-stdinc.h>
     36 
     37 #include <stdio.h>
     38 #include <string.h>
     39 #ifdef HAVE_STRFTIME
     40 #include <time.h>
     41 #endif
     42 
     43 #include "interface.h"
     44 #include "addrtoname.h"
     45 #include "extract.h"
     46 #ifdef MODEMASK
     47 #undef MODEMASK					/* Solaris sucks */
     48 #endif
     49 #include "ntp.h"
     50 
     51 static void p_sfix(const struct s_fixedpt *);
     52 static void p_ntp_time(const struct l_fixedpt *);
     53 static void p_ntp_delta(const struct l_fixedpt *, const struct l_fixedpt *);
     54 
     55 static struct tok ntp_mode_values[] = {
     56     { MODE_UNSPEC,    "unspecified" },
     57     { MODE_SYM_ACT,   "symmetric active" },
     58     { MODE_SYM_PAS,   "symmetric passive" },
     59     { MODE_CLIENT,    "Client" },
     60     { MODE_SERVER,    "Server" },
     61     { MODE_BROADCAST, "Broadcast" },
     62     { MODE_RES1,      "Reserved" },
     63     { MODE_RES2,      "Reserved" },
     64     { 0, NULL }
     65 };
     66 
     67 static struct tok ntp_leapind_values[] = {
     68     { NO_WARNING,     "" },
     69     { PLUS_SEC,       "+1s" },
     70     { MINUS_SEC,      "-1s" },
     71     { ALARM,          "clock unsynchronized" },
     72     { 0, NULL }
     73 };
     74 
     75 /*
     76  * Print ntp requests
     77  */
     78 void
     79 ntp_print(register const u_char *cp, u_int length)
     80 {
     81 	register const struct ntpdata *bp;
     82 	int mode, version, leapind;
     83 
     84 	bp = (struct ntpdata *)cp;
     85 
     86 	TCHECK(bp->status);
     87 
     88 	version = (int)(bp->status & VERSIONMASK) >> 3;
     89 	printf("NTPv%d", version);
     90 
     91 	mode = bp->status & MODEMASK;
     92         if (!vflag) {
     93             printf (", %s, length %u",
     94                     tok2str(ntp_mode_values, "Unknown mode", mode),
     95                     length);
     96             return;
     97         }
     98 
     99         printf (", length %u\n\t%s",
    100                 length,
    101                 tok2str(ntp_mode_values, "Unknown mode", mode));
    102 
    103 	leapind = bp->status & LEAPMASK;
    104         printf (", Leap indicator: %s (%u)",
    105                 tok2str(ntp_leapind_values, "Unknown", leapind),
    106                 leapind);
    107 
    108 	TCHECK(bp->stratum);
    109 	printf(", Stratum %u", bp->stratum);
    110 
    111 	TCHECK(bp->ppoll);
    112 	printf(", poll %us", bp->ppoll);
    113 
    114 	/* Can't TCHECK bp->precision bitfield so bp->distance + 0 instead */
    115 	TCHECK2(bp->root_delay, 0);
    116 	printf(", precision %d", bp->precision);
    117 
    118 	TCHECK(bp->root_delay);
    119 	fputs("\n\tRoot Delay: ", stdout);
    120 	p_sfix(&bp->root_delay);
    121 
    122 	TCHECK(bp->root_dispersion);
    123 	fputs(", Root dispersion: ", stdout);
    124 	p_sfix(&bp->root_dispersion);
    125 
    126 	TCHECK(bp->refid);
    127 	fputs(", Reference-ID: ", stdout);
    128 	/* Interpretation depends on stratum */
    129 	switch (bp->stratum) {
    130 
    131 	case UNSPECIFIED:
    132 		printf("(unspec)");
    133 		break;
    134 
    135 	case PRIM_REF:
    136 		if (fn_printn((u_char *)&(bp->refid), 4, snapend))
    137 			goto trunc;
    138 		break;
    139 
    140 	case INFO_QUERY:
    141 		printf("%s INFO_QUERY", ipaddr_string(&(bp->refid)));
    142 		/* this doesn't have more content */
    143 		return;
    144 
    145 	case INFO_REPLY:
    146 		printf("%s INFO_REPLY", ipaddr_string(&(bp->refid)));
    147 		/* this is too complex to be worth printing */
    148 		return;
    149 
    150 	default:
    151 		printf("%s", ipaddr_string(&(bp->refid)));
    152 		break;
    153 	}
    154 
    155 	TCHECK(bp->ref_timestamp);
    156 	fputs("\n\t  Reference Timestamp:  ", stdout);
    157 	p_ntp_time(&(bp->ref_timestamp));
    158 
    159 	TCHECK(bp->org_timestamp);
    160 	fputs("\n\t  Originator Timestamp: ", stdout);
    161 	p_ntp_time(&(bp->org_timestamp));
    162 
    163 	TCHECK(bp->rec_timestamp);
    164 	fputs("\n\t  Receive Timestamp:    ", stdout);
    165 	p_ntp_time(&(bp->rec_timestamp));
    166 
    167 	TCHECK(bp->xmt_timestamp);
    168 	fputs("\n\t  Transmit Timestamp:   ", stdout);
    169 	p_ntp_time(&(bp->xmt_timestamp));
    170 
    171 	fputs("\n\t    Originator - Receive Timestamp:  ", stdout);
    172 	p_ntp_delta(&(bp->org_timestamp), &(bp->rec_timestamp));
    173 
    174 	fputs("\n\t    Originator - Transmit Timestamp: ", stdout);
    175 	p_ntp_delta(&(bp->org_timestamp), &(bp->xmt_timestamp));
    176 
    177         /* FIXME key-id, authentication */
    178 
    179 	return;
    180 
    181 trunc:
    182 	fputs(" [|ntp]", stdout);
    183 }
    184 
    185 static void
    186 p_sfix(register const struct s_fixedpt *sfp)
    187 {
    188 	register int i;
    189 	register int f;
    190 	register float ff;
    191 
    192 	i = EXTRACT_16BITS(&sfp->int_part);
    193 	f = EXTRACT_16BITS(&sfp->fraction);
    194 	ff = f / 65536.0;	/* shift radix point by 16 bits */
    195 	f = ff * 1000000.0;	/* Treat fraction as parts per million */
    196 	printf("%d.%06d", i, f);
    197 }
    198 
    199 #define	FMAXINT	(4294967296.0)	/* floating point rep. of MAXINT */
    200 
    201 static void
    202 p_ntp_time(register const struct l_fixedpt *lfp)
    203 {
    204 	register int32_t i;
    205 	register u_int32_t uf;
    206 	register u_int32_t f;
    207 	register float ff;
    208 
    209 	i = EXTRACT_32BITS(&lfp->int_part);
    210 	uf = EXTRACT_32BITS(&lfp->fraction);
    211 	ff = uf;
    212 	if (ff < 0.0)		/* some compilers are buggy */
    213 		ff += FMAXINT;
    214 	ff = ff / FMAXINT;	/* shift radix point by 32 bits */
    215 	f = ff * 1000000000.0;	/* treat fraction as parts per billion */
    216 	printf("%u.%09d", i, f);
    217 
    218 #ifdef HAVE_STRFTIME
    219 	/*
    220 	 * print the time in human-readable format.
    221 	 */
    222 	if (i) {
    223 	    time_t seconds = i - JAN_1970;
    224 	    struct tm *tm;
    225 	    char time_buf[128];
    226 
    227 	    tm = localtime(&seconds);
    228 	    strftime(time_buf, sizeof (time_buf), "%Y/%m/%d %H:%M:%S", tm);
    229 	    printf (" (%s)", time_buf);
    230 	}
    231 #endif
    232 }
    233 
    234 /* Prints time difference between *lfp and *olfp */
    235 static void
    236 p_ntp_delta(register const struct l_fixedpt *olfp,
    237 	    register const struct l_fixedpt *lfp)
    238 {
    239 	register int32_t i;
    240 	register u_int32_t u, uf;
    241 	register u_int32_t ou, ouf;
    242 	register u_int32_t f;
    243 	register float ff;
    244 	int signbit;
    245 
    246 	u = EXTRACT_32BITS(&lfp->int_part);
    247 	ou = EXTRACT_32BITS(&olfp->int_part);
    248 	uf = EXTRACT_32BITS(&lfp->fraction);
    249 	ouf = EXTRACT_32BITS(&olfp->fraction);
    250 	if (ou == 0 && ouf == 0) {
    251 		p_ntp_time(lfp);
    252 		return;
    253 	}
    254 
    255 	i = u - ou;
    256 
    257 	if (i > 0) {		/* new is definitely greater than old */
    258 		signbit = 0;
    259 		f = uf - ouf;
    260 		if (ouf > uf)	/* must borrow from high-order bits */
    261 			i -= 1;
    262 	} else if (i < 0) {	/* new is definitely less than old */
    263 		signbit = 1;
    264 		f = ouf - uf;
    265 		if (uf > ouf)	/* must carry into the high-order bits */
    266 			i += 1;
    267 		i = -i;
    268 	} else {		/* int_part is zero */
    269 		if (uf > ouf) {
    270 			signbit = 0;
    271 			f = uf - ouf;
    272 		} else {
    273 			signbit = 1;
    274 			f = ouf - uf;
    275 		}
    276 	}
    277 
    278 	ff = f;
    279 	if (ff < 0.0)		/* some compilers are buggy */
    280 		ff += FMAXINT;
    281 	ff = ff / FMAXINT;	/* shift radix point by 32 bits */
    282 	f = ff * 1000000000.0;	/* treat fraction as parts per billion */
    283 	if (signbit)
    284 		putchar('-');
    285 	else
    286 		putchar('+');
    287 	printf("%d.%09d", i, f);
    288 }
    289 
    290