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[] =
  28     "@(#) $Header: /tcpdump/master/tcpdump/print-ntp.c,v 1.34 2002-08-01 08:53:21 risso 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
  40 #include "interface.h"
  41 #include "addrtoname.h"
  42 #ifdef MODEMASK
  43 #undef MODEMASK                                 /* Solaris sucks */
  44 #endif
  45 #include "ntp.h"
  46
  47 static void p_sfix(const struct s_fixedpt *);
  48 static void p_ntp_time(const struct l_fixedpt *);
  49 static void p_ntp_delta(const struct l_fixedpt *, const struct l_fixedpt *);
  50
  51 /*
  52  * Print ntp requests
  53  */
  54 void
  55 ntp_print(register const u_char *cp, u_int length)
  56 {
  57         register const struct ntpdata *bp;
  58         int mode, version, leapind;
  59
  60         bp = (struct ntpdata *)cp;
  61         /* Note funny sized packets */
  62         if (length != sizeof(struct ntpdata))
  63                 (void)printf(" [len=%d]", length);
  64
  65         TCHECK(bp->status);
  66
  67         version = (int)(bp->status & VERSIONMASK) >> 3;
  68         printf(" v%d", version);
  69
  70         leapind = bp->status & LEAPMASK;
  71         switch (leapind) {
  72
  73         case NO_WARNING:
  74                 break;
  75
  76         case PLUS_SEC:
  77                 fputs(" +1s", stdout);
  78                 break;
  79
  80         case MINUS_SEC:
  81                 fputs(" -1s", stdout);
  82                 break;
  83         }
  84
  85         mode = bp->status & MODEMASK;
  86         switch (mode) {
  87
  88         case MODE_UNSPEC:       /* unspecified */
  89                 fputs(" unspec", stdout);
  90                 break;
  91
  92         case MODE_SYM_ACT:      /* symmetric active */
  93                 fputs(" sym_act", stdout);
  94                 break;
  95
  96         case MODE_SYM_PAS:      /* symmetric passive */
  97                 fputs(" sym_pas", stdout);
  98                 break;
  99
 100         case MODE_CLIENT:       /* client */
 101                 fputs(" client", stdout);
 102                 break;
 103
 104         case MODE_SERVER:       /* server */
 105                 fputs(" server", stdout);
 106                 break;
 107
 108         case MODE_BROADCAST:    /* broadcast */
 109                 fputs(" bcast", stdout);
 110                 break;
 111
 112         case MODE_RES1:         /* reserved */
 113                 fputs(" res1", stdout);
 114                 break;
 115
 116         case MODE_RES2:         /* reserved */
 117                 fputs(" res2", stdout);
 118                 break;
 119
 120         }
 121
 122         TCHECK(bp->stratum);
 123         printf(" strat %d", bp->stratum);
 124
 125         TCHECK(bp->ppoll);
 126         printf(" poll %d", bp->ppoll);
 127
 128         /* Can't TCHECK bp->precision bitfield so bp->distance + 0 instead */
 129         TCHECK2(bp->distance, 0);
 130         printf(" prec %d", bp->precision);
 131
 132         if (!vflag)
 133                 return;
 134
 135         TCHECK(bp->distance);
 136         fputs(" dist ", stdout);
 137         p_sfix(&bp->distance);
 138
 139         TCHECK(bp->dispersion);
 140         fputs(" disp ", stdout);
 141         p_sfix(&bp->dispersion);
 142
 143         TCHECK(bp->refid);
 144         fputs(" ref ", stdout);
 145         /* Interpretation depends on stratum */
 146         switch (bp->stratum) {
 147
 148         case UNSPECIFIED:
 149                 printf("(unspec)");
 150                 break;
 151
 152         case PRIM_REF:
 153                 fn_printn((u_char *)&(bp->refid), 4, NULL);
 154                 break;
 155
 156         case INFO_QUERY:
 157                 printf("%s INFO_QUERY", ipaddr_string(&(bp->refid)));
 158                 /* this doesn't have more content */
 159                 return;
 160
 161         case INFO_REPLY:
 162                 printf("%s INFO_REPLY", ipaddr_string(&(bp->refid)));
 163                 /* this is too complex to be worth printing */
 164                 return;
 165
 166         default:
 167                 printf("%s", ipaddr_string(&(bp->refid)));
 168                 break;
 169         }
 170
 171         TCHECK(bp->reftime);
 172         putchar('@');
 173         p_ntp_time(&(bp->reftime));
 174
 175         TCHECK(bp->org);
 176         fputs(" orig ", stdout);
 177         p_ntp_time(&(bp->org));
 178
 179         TCHECK(bp->rec);
 180         fputs(" rec ", stdout);
 181         p_ntp_delta(&(bp->org), &(bp->rec));
 182
 183         TCHECK(bp->xmt);
 184         fputs(" xmt ", stdout);
 185         p_ntp_delta(&(bp->org), &(bp->xmt));
 186
 187         return;
 188
 189 trunc:
 190         fputs(" [|ntp]", stdout);
 191 }
 192
 193 static void
 194 p_sfix(register const struct s_fixedpt *sfp)
 195 {
 196         register int i;
 197         register int f;
 198         register float ff;
 199
 200         i = ntohs(sfp->int_part);
 201         f = ntohs(sfp->fraction);
 202         ff = f / 65536.0;       /* shift radix point by 16 bits */
 203         f = ff * 1000000.0;     /* Treat fraction as parts per million */
 204         printf("%d.%06d", i, f);
 205 }
 206
 207 #define FMAXINT (4294967296.0)  /* floating point rep. of MAXINT */
 208
 209 static void
 210 p_ntp_time(register const struct l_fixedpt *lfp)
 211 {
 212         register int32_t i;
 213         register u_int32_t uf;
 214         register u_int32_t f;
 215         register float ff;
 216
 217         i = ntohl(lfp->int_part);
 218         uf = ntohl(lfp->fraction);
 219         ff = uf;
 220         if (ff < 0.0)           /* some compilers are buggy */
 221                 ff += FMAXINT;
 222         ff = ff / FMAXINT;      /* shift radix point by 32 bits */
 223         f = ff * 1000000000.0;  /* treat fraction as parts per billion */
 224         printf("%u.%09d", i, f);
 225 }
 226
 227 /* Prints time difference between *lfp and *olfp */
 228 static void
 229 p_ntp_delta(register const struct l_fixedpt *olfp,
 230             register const struct l_fixedpt *lfp)
 231 {
 232         register int32_t i;
 233         register u_int32_t uf;
 234         register u_int32_t ouf;
 235         register u_int32_t f;
 236         register float ff;
 237         int signbit;
 238
 239         i = ntohl(lfp->int_part) - ntohl(olfp->int_part);
 240
 241         uf = ntohl(lfp->fraction);
 242         ouf = ntohl(olfp->fraction);
 243
 244         if (i > 0) {            /* new is definitely greater than old */
 245                 signbit = 0;
 246                 f = uf - ouf;
 247                 if (ouf > uf)   /* must borrow from high-order bits */
 248                         i -= 1;
 249         } else if (i < 0) {     /* new is definitely less than old */
 250                 signbit = 1;
 251                 f = ouf - uf;
 252                 if (uf > ouf)   /* must carry into the high-order bits */
 253                         i += 1;
 254                 i = -i;
 255         } else {                /* int_part is zero */
 256                 if (uf > ouf) {
 257                         signbit = 0;
 258                         f = uf - ouf;
 259                 } else {
 260                         signbit = 1;
 261                         f = ouf - uf;
 262                 }
 263         }
 264
 265         ff = f;
 266         if (ff < 0.0)           /* some compilers are buggy */
 267                 ff += FMAXINT;
 268         ff = ff / FMAXINT;      /* shift radix point by 32 bits */
 269         f = ff * 1000000000.0;  /* treat fraction as parts per billion */
 270         if (signbit)
 271                 putchar('-');
 272         else
 273                 putchar('+');
 274         printf("%d.%09d", i, f);
 275 }