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 1.36 2002-12-28 17:15:06 hannes 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 #include "extract.h"
  43 #ifdef MODEMASK
  44 #undef MODEMASK                                 /* Solaris sucks */
  45 #endif
  46 #include "ntp.h"
  47
  48 static void p_sfix(const struct s_fixedpt *);
  49 static void p_ntp_time(const struct l_fixedpt *);
  50 static void p_ntp_delta(const struct l_fixedpt *, const struct l_fixedpt *);
  51
  52 /*
  53  * Print ntp requests
  54  */
  55 void
  56 ntp_print(register const u_char *cp, u_int length)
  57 {
  58         register const struct ntpdata *bp;
  59         int mode, version, leapind;
  60
  61         bp = (struct ntpdata *)cp;
  62         /* Note funny sized packets */
  63         if (length != sizeof(struct ntpdata))
  64                 (void)printf(" [len=%d]", length);
  65
  66         TCHECK(bp->status);
  67
  68         version = (int)(bp->status & VERSIONMASK) >> 3;
  69         printf("NTPv%d", version);
  70
  71         leapind = bp->status & LEAPMASK;
  72         switch (leapind) {
  73
  74         case NO_WARNING:
  75                 break;
  76
  77         case PLUS_SEC:
  78                 fputs(" +1s", stdout);
  79                 break;
  80
  81         case MINUS_SEC:
  82                 fputs(" -1s", stdout);
  83                 break;
  84         }
  85
  86         mode = bp->status & MODEMASK;
  87         switch (mode) {
  88
  89         case MODE_UNSPEC:       /* unspecified */
  90                 fputs(" unspec", stdout);
  91                 break;
  92
  93         case MODE_SYM_ACT:      /* symmetric active */
  94                 fputs(" sym_act", stdout);
  95                 break;
  96
  97         case MODE_SYM_PAS:      /* symmetric passive */
  98                 fputs(" sym_pas", stdout);
  99                 break;
 100
 101         case MODE_CLIENT:       /* client */
 102                 fputs(" client", stdout);
 103                 break;
 104
 105         case MODE_SERVER:       /* server */
 106                 fputs(" server", stdout);
 107                 break;
 108
 109         case MODE_BROADCAST:    /* broadcast */
 110                 fputs(" bcast", stdout);
 111                 break;
 112
 113         case MODE_RES1:         /* reserved */
 114                 fputs(" res1", stdout);
 115                 break;
 116
 117         case MODE_RES2:         /* reserved */
 118                 fputs(" res2", stdout);
 119                 break;
 120
 121         }
 122
 123         TCHECK(bp->stratum);
 124         printf(", strat %d", bp->stratum);
 125
 126         TCHECK(bp->ppoll);
 127         printf(", poll %d", bp->ppoll);
 128
 129         /* Can't TCHECK bp->precision bitfield so bp->distance + 0 instead */
 130         TCHECK2(bp->distance, 0);
 131         printf(", prec %d", bp->precision);
 132
 133         if (!vflag)
 134                 return;
 135
 136         TCHECK(bp->distance);
 137         fputs(" dist ", stdout);
 138         p_sfix(&bp->distance);
 139
 140         TCHECK(bp->dispersion);
 141         fputs(", disp ", stdout);
 142         p_sfix(&bp->dispersion);
 143
 144         TCHECK(bp->refid);
 145         fputs(", ref ", stdout);
 146         /* Interpretation depends on stratum */
 147         switch (bp->stratum) {
 148
 149         case UNSPECIFIED:
 150                 printf("(unspec)");
 151                 break;
 152
 153         case PRIM_REF:
 154                 fn_printn((u_char *)&(bp->refid), 4, NULL);
 155                 break;
 156
 157         case INFO_QUERY:
 158                 printf("%s INFO_QUERY", ipaddr_string(&(bp->refid)));
 159                 /* this doesn't have more content */
 160                 return;
 161
 162         case INFO_REPLY:
 163                 printf("%s INFO_REPLY", ipaddr_string(&(bp->refid)));
 164                 /* this is too complex to be worth printing */
 165                 return;
 166
 167         default:
 168                 printf("%s", ipaddr_string(&(bp->refid)));
 169                 break;
 170         }
 171
 172         TCHECK(bp->reftime);
 173         putchar('@');
 174         p_ntp_time(&(bp->reftime));
 175
 176         TCHECK(bp->org);
 177         fputs(" orig ", stdout);
 178         p_ntp_time(&(bp->org));
 179
 180         TCHECK(bp->rec);
 181         fputs(" rec ", stdout);
 182         p_ntp_delta(&(bp->org), &(bp->rec));
 183
 184         TCHECK(bp->xmt);
 185         fputs(" xmt ", stdout);
 186         p_ntp_delta(&(bp->org), &(bp->xmt));
 187
 188         return;
 189
 190 trunc:
 191         fputs(" [|ntp]", stdout);
 192 }
 193
 194 static void
 195 p_sfix(register const struct s_fixedpt *sfp)
 196 {
 197         register int i;
 198         register int f;
 199         register float ff;
 200
 201         i = EXTRACT_16BITS(&sfp->int_part);
 202         f = EXTRACT_16BITS(&sfp->fraction);
 203         ff = f / 65536.0;       /* shift radix point by 16 bits */
 204         f = ff * 1000000.0;     /* Treat fraction as parts per million */
 205         printf("%d.%06d", i, f);
 206 }
 207
 208 #define FMAXINT (4294967296.0)  /* floating point rep. of MAXINT */
 209
 210 static void
 211 p_ntp_time(register const struct l_fixedpt *lfp)
 212 {
 213         register int32_t i;
 214         register u_int32_t uf;
 215         register u_int32_t f;
 216         register float ff;
 217
 218         i = EXTRACT_32BITS(&lfp->int_part);
 219         uf = EXTRACT_32BITS(&lfp->fraction);
 220         ff = uf;
 221         if (ff < 0.0)           /* some compilers are buggy */
 222                 ff += FMAXINT;
 223         ff = ff / FMAXINT;      /* shift radix point by 32 bits */
 224         f = ff * 1000000000.0;  /* treat fraction as parts per billion */
 225         printf("%u.%09d", i, f);
 226 }
 227
 228 /* Prints time difference between *lfp and *olfp */
 229 static void
 230 p_ntp_delta(register const struct l_fixedpt *olfp,
 231             register const struct l_fixedpt *lfp)
 232 {
 233         register int32_t i;
 234         register u_int32_t uf;
 235         register u_int32_t ouf;
 236         register u_int32_t f;
 237         register float ff;
 238         int signbit;
 239
 240         i = EXTRACT_32BITS(&lfp->int_part) - EXTRACT_32BITS(&olfp->int_part);
 241
 242         uf = EXTRACT_32BITS(&lfp->fraction);
 243         ouf = EXTRACT_32BITS(&olfp->fraction);
 244
 245         if (i > 0) {            /* new is definitely greater than old */
 246                 signbit = 0;
 247                 f = uf - ouf;
 248                 if (ouf > uf)   /* must borrow from high-order bits */
 249                         i -= 1;
 250         } else if (i < 0) {     /* new is definitely less than old */
 251                 signbit = 1;
 252                 f = ouf - uf;
 253                 if (uf > ouf)   /* must carry into the high-order bits */
 254                         i += 1;
 255                 i = -i;
 256         } else {                /* int_part is zero */
 257                 if (uf > ouf) {
 258                         signbit = 0;
 259                         f = uf - ouf;
 260                 } else {
 261                         signbit = 1;
 262                         f = ouf - uf;
 263                 }
 264         }
 265
 266         ff = f;
 267         if (ff < 0.0)           /* some compilers are buggy */
 268                 ff += FMAXINT;
 269         ff = ff / FMAXINT;      /* shift radix point by 32 bits */
 270         f = ff * 1000000000.0;  /* treat fraction as parts per billion */
 271         if (signbit)
 272                 putchar('-');
 273         else
 274                 putchar('+');
 275         printf("%d.%09d", i, f);
 276 }
 277