The Tcpdump Group git mirrors - tcpdump/blob - print-ntp.c

   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 1.37.2.2 2003-11-16 08:51:36 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 /*
  56  * Print ntp requests
  57  */
  58 void
  59 ntp_print(register const u_char *cp, u_int length)
  60 {
  61         register const struct ntpdata *bp;
  62         int mode, version, leapind;
  63
  64         bp = (struct ntpdata *)cp;
  65         /* Note funny sized packets */
  66         if (length != sizeof(struct ntpdata))
  67                 (void)printf(" [len=%d]", length);
  68
  69         TCHECK(bp->status);
  70
  71         version = (int)(bp->status & VERSIONMASK) >> 3;
  72         printf("NTPv%d", version);
  73
  74         leapind = bp->status & LEAPMASK;
  75         switch (leapind) {
  76
  77         case NO_WARNING:
  78                 break;
  79
  80         case PLUS_SEC:
  81                 fputs(" +1s", stdout);
  82                 break;
  83
  84         case MINUS_SEC:
  85                 fputs(" -1s", stdout);
  86                 break;
  87         }
  88
  89         mode = bp->status & MODEMASK;
  90         switch (mode) {
  91
  92         case MODE_UNSPEC:       /* unspecified */
  93                 fputs(" unspec", stdout);
  94                 break;
  95
  96         case MODE_SYM_ACT:      /* symmetric active */
  97                 fputs(" sym_act", stdout);
  98                 break;
  99
 100         case MODE_SYM_PAS:      /* symmetric passive */
 101                 fputs(" sym_pas", stdout);
 102                 break;
 103
 104         case MODE_CLIENT:       /* client */
 105                 fputs(" client", stdout);
 106                 break;
 107
 108         case MODE_SERVER:       /* server */
 109                 fputs(" server", stdout);
 110                 break;
 111
 112         case MODE_BROADCAST:    /* broadcast */
 113                 fputs(" bcast", stdout);
 114                 break;
 115
 116         case MODE_RES1:         /* reserved */
 117                 fputs(" res1", stdout);
 118                 break;
 119
 120         case MODE_RES2:         /* reserved */
 121                 fputs(" res2", stdout);
 122                 break;
 123
 124         }
 125
 126         TCHECK(bp->stratum);
 127         printf(", strat %d", bp->stratum);
 128
 129         TCHECK(bp->ppoll);
 130         printf(", poll %d", bp->ppoll);
 131
 132         /* Can't TCHECK bp->precision bitfield so bp->distance + 0 instead */
 133         TCHECK2(bp->distance, 0);
 134         printf(", prec %d", bp->precision);
 135
 136         if (!vflag)
 137                 return;
 138
 139         TCHECK(bp->distance);
 140         fputs(" dist ", stdout);
 141         p_sfix(&bp->distance);
 142
 143         TCHECK(bp->dispersion);
 144         fputs(", disp ", stdout);
 145         p_sfix(&bp->dispersion);
 146
 147         TCHECK(bp->refid);
 148         fputs(", ref ", stdout);
 149         /* Interpretation depends on stratum */
 150         switch (bp->stratum) {
 151
 152         case UNSPECIFIED:
 153                 printf("(unspec)");
 154                 break;
 155
 156         case PRIM_REF:
 157                 fn_printn((u_char *)&(bp->refid), 4, NULL);
 158                 break;
 159
 160         case INFO_QUERY:
 161                 printf("%s INFO_QUERY", ipaddr_string(&(bp->refid)));
 162                 /* this doesn't have more content */
 163                 return;
 164
 165         case INFO_REPLY:
 166                 printf("%s INFO_REPLY", ipaddr_string(&(bp->refid)));
 167                 /* this is too complex to be worth printing */
 168                 return;
 169
 170         default:
 171                 printf("%s", ipaddr_string(&(bp->refid)));
 172                 break;
 173         }
 174
 175         TCHECK(bp->reftime);
 176         putchar('@');
 177         p_ntp_time(&(bp->reftime));
 178
 179         TCHECK(bp->org);
 180         fputs(" orig ", stdout);
 181         p_ntp_time(&(bp->org));
 182
 183         TCHECK(bp->rec);
 184         fputs(" rec ", stdout);
 185         p_ntp_delta(&(bp->org), &(bp->rec));
 186
 187         TCHECK(bp->xmt);
 188         fputs(" xmt ", stdout);
 189         p_ntp_delta(&(bp->org), &(bp->xmt));
 190
 191         return;
 192
 193 trunc:
 194         fputs(" [|ntp]", stdout);
 195 }
 196
 197 static void
 198 p_sfix(register const struct s_fixedpt *sfp)
 199 {
 200         register int i;
 201         register int f;
 202         register float ff;
 203
 204         i = EXTRACT_16BITS(&sfp->int_part);
 205         f = EXTRACT_16BITS(&sfp->fraction);
 206         ff = f / 65536.0;       /* shift radix point by 16 bits */
 207         f = ff * 1000000.0;     /* Treat fraction as parts per million */
 208         printf("%d.%06d", i, f);
 209 }
 210
 211 #define FMAXINT (4294967296.0)  /* floating point rep. of MAXINT */
 212
 213 static void
 214 p_ntp_time(register const struct l_fixedpt *lfp)
 215 {
 216         register int32_t i;
 217         register u_int32_t uf;
 218         register u_int32_t f;
 219         register float ff;
 220
 221         i = EXTRACT_32BITS(&lfp->int_part);
 222         uf = EXTRACT_32BITS(&lfp->fraction);
 223         ff = uf;
 224         if (ff < 0.0)           /* some compilers are buggy */
 225                 ff += FMAXINT;
 226         ff = ff / FMAXINT;      /* shift radix point by 32 bits */
 227         f = ff * 1000000000.0;  /* treat fraction as parts per billion */
 228         printf("%u.%09d", i, f);
 229
 230 #ifdef HAVE_STRFTIME
 231         /*
 232          * For extra verbosity, print the time in human-readable format.
 233          */
 234         if (vflag > 1 && i) {
 235             time_t seconds = i - JAN_1970;
 236             struct tm *tm;
 237             char time_buf[128];
 238
 239             tm = localtime(&seconds);
 240             strftime(time_buf, sizeof (time_buf), "%Y/%m/%d %H:%M:%S", tm);
 241             printf (" (%s)", time_buf);
 242         }
 243 #endif
 244 }
 245
 246 /* Prints time difference between *lfp and *olfp */
 247 static void
 248 p_ntp_delta(register const struct l_fixedpt *olfp,
 249             register const struct l_fixedpt *lfp)
 250 {
 251         register int32_t i;
 252         register u_int32_t u, uf;
 253         register u_int32_t ou, ouf;
 254         register u_int32_t f;
 255         register float ff;
 256         int signbit;
 257
 258         u = EXTRACT_32BITS(&lfp->int_part);
 259         ou = EXTRACT_32BITS(&olfp->int_part);
 260         uf = EXTRACT_32BITS(&lfp->fraction);
 261         ouf = EXTRACT_32BITS(&olfp->fraction);
 262         if (ou == 0 && ouf == 0) {
 263                 p_ntp_time(lfp);
 264                 return;
 265         }
 266
 267         i = u - ou;
 268
 269         if (i > 0) {            /* new is definitely greater than old */
 270                 signbit = 0;
 271                 f = uf - ouf;
 272                 if (ouf > uf)   /* must borrow from high-order bits */
 273                         i -= 1;
 274         } else if (i < 0) {     /* new is definitely less than old */
 275                 signbit = 1;
 276                 f = ouf - uf;
 277                 if (uf > ouf)   /* must carry into the high-order bits */
 278                         i += 1;
 279                 i = -i;
 280         } else {                /* int_part is zero */
 281                 if (uf > ouf) {
 282                         signbit = 0;
 283                         f = uf - ouf;
 284                 } else {
 285                         signbit = 1;
 286                         f = ouf - uf;
 287                 }
 288         }
 289
 290         ff = f;
 291         if (ff < 0.0)           /* some compilers are buggy */
 292                 ff += FMAXINT;
 293         ff = ff / FMAXINT;      /* shift radix point by 32 bits */
 294         f = ff * 1000000000.0;  /* treat fraction as parts per billion */
 295         if (signbit)
 296                 putchar('-');
 297         else
 298                 putchar('+');
 299         printf("%d.%09d", i, f);
 300 }
 301