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 1.32 2001-08-20 15:36:57 fenner Exp $ (LBL)";
  29 #endif
  30
  31 #ifdef HAVE_CONFIG_H
  32 #include "config.h"
  33 #endif
  34
  35 #include <sys/param.h>
  36 #include <sys/time.h>
  37 #include <sys/socket.h>
  38
  39 #include <netinet/in.h>
  40
  41 #include <ctype.h>
  42 #include <stdio.h>
  43 #include <string.h>
  44
  45 #include "interface.h"
  46 #include "addrtoname.h"
  47 #ifdef MODEMASK
  48 #undef MODEMASK                                 /* Solaris sucks */
  49 #endif
  50 #include "ntp.h"
  51
  52 static void p_sfix(const struct s_fixedpt *);
  53 static void p_ntp_time(const struct l_fixedpt *);
  54 static void p_ntp_delta(const struct l_fixedpt *, const struct l_fixedpt *);
  55
  56 /*
  57  * Print ntp requests
  58  */
  59 void
  60 ntp_print(register const u_char *cp, u_int length)
  61 {
  62         register const struct ntpdata *bp;
  63         int mode, version, leapind;
  64
  65         bp = (struct ntpdata *)cp;
  66         /* Note funny sized packets */
  67         if (length != sizeof(struct ntpdata))
  68                 (void)printf(" [len=%d]", length);
  69
  70         TCHECK(bp->status);
  71
  72         version = (int)(bp->status & VERSIONMASK) >> 3;
  73         printf(" v%d", version);
  74
  75         leapind = bp->status & LEAPMASK;
  76         switch (leapind) {
  77
  78         case NO_WARNING:
  79                 break;
  80
  81         case PLUS_SEC:
  82                 fputs(" +1s", stdout);
  83                 break;
  84
  85         case MINUS_SEC:
  86                 fputs(" -1s", stdout);
  87                 break;
  88         }
  89
  90         mode = bp->status & MODEMASK;
  91         switch (mode) {
  92
  93         case MODE_UNSPEC:       /* unspecified */
  94                 fputs(" unspec", stdout);
  95                 break;
  96
  97         case MODE_SYM_ACT:      /* symmetric active */
  98                 fputs(" sym_act", stdout);
  99                 break;
 100
 101         case MODE_SYM_PAS:      /* symmetric passive */
 102                 fputs(" sym_pas", stdout);
 103                 break;
 104
 105         case MODE_CLIENT:       /* client */
 106                 fputs(" client", stdout);
 107                 break;
 108
 109         case MODE_SERVER:       /* server */
 110                 fputs(" server", stdout);
 111                 break;
 112
 113         case MODE_BROADCAST:    /* broadcast */
 114                 fputs(" bcast", stdout);
 115                 break;
 116
 117         case MODE_RES1:         /* reserved */
 118                 fputs(" res1", stdout);
 119                 break;
 120
 121         case MODE_RES2:         /* reserved */
 122                 fputs(" res2", stdout);
 123                 break;
 124
 125         }
 126
 127         TCHECK(bp->stratum);
 128         printf(" strat %d", bp->stratum);
 129
 130         TCHECK(bp->ppoll);
 131         printf(" poll %d", bp->ppoll);
 132
 133         /* Can't TCHECK bp->precision bitfield so bp->distance + 0 instead */
 134         TCHECK2(bp->distance, 0);
 135         printf(" prec %d", bp->precision);
 136
 137         if (!vflag)
 138                 return;
 139
 140         TCHECK(bp->distance);
 141         fputs(" dist ", stdout);
 142         p_sfix(&bp->distance);
 143
 144         TCHECK(bp->dispersion);
 145         fputs(" disp ", stdout);
 146         p_sfix(&bp->dispersion);
 147
 148         TCHECK(bp->refid);
 149         fputs(" ref ", stdout);
 150         /* Interpretation depends on stratum */
 151         switch (bp->stratum) {
 152
 153         case UNSPECIFIED:
 154                 printf("(unspec)");
 155                 break;
 156
 157         case PRIM_REF:
 158                 fn_printn((char *)&(bp->refid), 4, NULL);
 159                 break;
 160
 161         case INFO_QUERY:
 162                 printf("%s INFO_QUERY", ipaddr_string(&(bp->refid)));
 163                 /* this doesn't have more content */
 164                 return;
 165
 166         case INFO_REPLY:
 167                 printf("%s INFO_REPLY", ipaddr_string(&(bp->refid)));
 168                 /* this is too complex to be worth printing */
 169                 return;
 170
 171         default:
 172                 printf("%s", ipaddr_string(&(bp->refid)));
 173                 break;
 174         }
 175
 176         TCHECK(bp->reftime);
 177         putchar('@');
 178         p_ntp_time(&(bp->reftime));
 179
 180         TCHECK(bp->org);
 181         fputs(" orig ", stdout);
 182         p_ntp_time(&(bp->org));
 183
 184         TCHECK(bp->rec);
 185         fputs(" rec ", stdout);
 186         p_ntp_delta(&(bp->org), &(bp->rec));
 187
 188         TCHECK(bp->xmt);
 189         fputs(" xmt ", stdout);
 190         p_ntp_delta(&(bp->org), &(bp->xmt));
 191
 192         return;
 193
 194 trunc:
 195         fputs(" [|ntp]", stdout);
 196 }
 197
 198 static void
 199 p_sfix(register const struct s_fixedpt *sfp)
 200 {
 201         register int i;
 202         register int f;
 203         register float ff;
 204
 205         i = ntohs(sfp->int_part);
 206         f = ntohs(sfp->fraction);
 207         ff = f / 65536.0;       /* shift radix point by 16 bits */
 208         f = ff * 1000000.0;     /* Treat fraction as parts per million */
 209         printf("%d.%06d", i, f);
 210 }
 211
 212 #define FMAXINT (4294967296.0)  /* floating point rep. of MAXINT */
 213
 214 static void
 215 p_ntp_time(register const struct l_fixedpt *lfp)
 216 {
 217         register int32_t i;
 218         register u_int32_t uf;
 219         register u_int32_t f;
 220         register float ff;
 221
 222         i = ntohl(lfp->int_part);
 223         uf = ntohl(lfp->fraction);
 224         ff = uf;
 225         if (ff < 0.0)           /* some compilers are buggy */
 226                 ff += FMAXINT;
 227         ff = ff / FMAXINT;      /* shift radix point by 32 bits */
 228         f = ff * 1000000000.0;  /* treat fraction as parts per billion */
 229         printf("%u.%09d", i, f);
 230 }
 231
 232 /* Prints time difference between *lfp and *olfp */
 233 static void
 234 p_ntp_delta(register const struct l_fixedpt *olfp,
 235             register const struct l_fixedpt *lfp)
 236 {
 237         register int32_t i;
 238         register u_int32_t uf;
 239         register u_int32_t ouf;
 240         register u_int32_t f;
 241         register float ff;
 242         int signbit;
 243
 244         i = ntohl(lfp->int_part) - ntohl(olfp->int_part);
 245
 246         uf = ntohl(lfp->fraction);
 247         ouf = ntohl(olfp->fraction);
 248
 249         if (i > 0) {            /* new is definitely greater than old */
 250                 signbit = 0;
 251                 f = uf - ouf;
 252                 if (ouf > uf)   /* must borrow from high-order bits */
 253                         i -= 1;
 254         } else if (i < 0) {     /* new is definitely less than old */
 255                 signbit = 1;
 256                 f = ouf - uf;
 257                 if (uf > ouf)   /* must carry into the high-order bits */
 258                         i += 1;
 259                 i = -i;
 260         } else {                /* int_part is zero */
 261                 if (uf > ouf) {
 262                         signbit = 0;
 263                         f = uf - ouf;
 264                 } else {
 265                         signbit = 1;
 266                         f = ouf - uf;
 267                 }
 268         }
 269
 270         ff = f;
 271         if (ff < 0.0)           /* some compilers are buggy */
 272                 ff += FMAXINT;
 273         ff = ff / FMAXINT;      /* shift radix point by 32 bits */
 274         f = ff * 1000000000.0;  /* treat fraction as parts per billion */
 275         if (signbit)
 276                 putchar('-');
 277         else
 278                 putchar('+');
 279         printf("%d.%09d", i, f);
 280 }