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 1.30 2000-09-28 06:43:04 guy 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 struct mbuf;
  40 struct rtentry;
  41
  42 #include <netinet/in.h>
  43
  44 #include <ctype.h>
  45 #include <stdio.h>
  46 #include <string.h>
  47
  48 #include "interface.h"
  49 #include "addrtoname.h"
  50 #ifdef MODEMASK
  51 #undef MODEMASK                                 /* Solaris sucks */
  52 #endif
  53 #include "ntp.h"
  54
  55 static void p_sfix(const struct s_fixedpt *);
  56 static void p_ntp_time(const struct l_fixedpt *);
  57 static void p_ntp_delta(const struct l_fixedpt *, const struct l_fixedpt *);
  58
  59 /*
  60  * Print ntp requests
  61  */
  62 void
  63 ntp_print(register const u_char *cp, u_int length)
  64 {
  65         register const struct ntpdata *bp;
  66         int mode, version, leapind;
  67         static char rclock[5];
  68
  69         bp = (struct ntpdata *)cp;
  70         /* Note funny sized packets */
  71         if (length != sizeof(struct ntpdata))
  72                 (void)printf(" [len=%d]", length);
  73
  74         TCHECK(bp->status);
  75
  76         version = (int)(bp->status & VERSIONMASK) >> 3;
  77         printf(" v%d", version);
  78
  79         leapind = bp->status & LEAPMASK;
  80         switch (leapind) {
  81
  82         case NO_WARNING:
  83                 break;
  84
  85         case PLUS_SEC:
  86                 fputs(" +1s", stdout);
  87                 break;
  88
  89         case MINUS_SEC:
  90                 fputs(" -1s", stdout);
  91                 break;
  92         }
  93
  94         mode = bp->status & MODEMASK;
  95         switch (mode) {
  96
  97         case MODE_UNSPEC:       /* unspecified */
  98                 fputs(" unspec", stdout);
  99                 break;
 100
 101         case MODE_SYM_ACT:      /* symmetric active */
 102                 fputs(" sym_act", stdout);
 103                 break;
 104
 105         case MODE_SYM_PAS:      /* symmetric passive */
 106                 fputs(" sym_pas", stdout);
 107                 break;
 108
 109         case MODE_CLIENT:       /* client */
 110                 fputs(" client", stdout);
 111                 break;
 112
 113         case MODE_SERVER:       /* server */
 114                 fputs(" server", stdout);
 115                 break;
 116
 117         case MODE_BROADCAST:    /* broadcast */
 118                 fputs(" bcast", stdout);
 119                 break;
 120
 121         case MODE_RES1:         /* reserved */
 122                 fputs(" res1", stdout);
 123                 break;
 124
 125         case MODE_RES2:         /* reserved */
 126                 fputs(" res2", stdout);
 127                 break;
 128
 129         }
 130
 131         TCHECK(bp->stratum);
 132         printf(" strat %d", bp->stratum);
 133
 134         TCHECK(bp->ppoll);
 135         printf(" poll %d", bp->ppoll);
 136
 137         /* Can't TCHECK bp->precision bitfield so bp->distance + 0 instead */
 138         TCHECK2(bp->distance, 0);
 139         printf(" prec %d", bp->precision);
 140
 141         if (!vflag)
 142                 return;
 143
 144         TCHECK(bp->distance);
 145         fputs(" dist ", stdout);
 146         p_sfix(&bp->distance);
 147
 148         TCHECK(bp->dispersion);
 149         fputs(" disp ", stdout);
 150         p_sfix(&bp->dispersion);
 151
 152         TCHECK(bp->refid);
 153         fputs(" ref ", stdout);
 154         /* Interpretation depends on stratum */
 155         switch (bp->stratum) {
 156
 157         case UNSPECIFIED:
 158                 printf("(unspec)");
 159                 break;
 160
 161         case PRIM_REF:
 162                 strncpy(rclock, (char *)&(bp->refid), 4);
 163                 rclock[4] = '\0';
 164                 fputs(rclock, stdout);
 165                 break;
 166
 167         case INFO_QUERY:
 168                 printf("%s INFO_QUERY", ipaddr_string(&(bp->refid)));
 169                 /* this doesn't have more content */
 170                 return;
 171
 172         case INFO_REPLY:
 173                 printf("%s INFO_REPLY", ipaddr_string(&(bp->refid)));
 174                 /* this is too complex to be worth printing */
 175                 return;
 176
 177         default:
 178                 printf("%s", ipaddr_string(&(bp->refid)));
 179                 break;
 180         }
 181
 182         TCHECK(bp->reftime);
 183         putchar('@');
 184         p_ntp_time(&(bp->reftime));
 185
 186         TCHECK(bp->org);
 187         fputs(" orig ", stdout);
 188         p_ntp_time(&(bp->org));
 189
 190         TCHECK(bp->rec);
 191         fputs(" rec ", stdout);
 192         p_ntp_delta(&(bp->org), &(bp->rec));
 193
 194         TCHECK(bp->xmt);
 195         fputs(" xmt ", stdout);
 196         p_ntp_delta(&(bp->org), &(bp->xmt));
 197
 198         return;
 199
 200 trunc:
 201         fputs(" [|ntp]", stdout);
 202 }
 203
 204 static void
 205 p_sfix(register const struct s_fixedpt *sfp)
 206 {
 207         register int i;
 208         register int f;
 209         register float ff;
 210
 211         i = ntohs(sfp->int_part);
 212         f = ntohs(sfp->fraction);
 213         ff = f / 65536.0;       /* shift radix point by 16 bits */
 214         f = ff * 1000000.0;     /* Treat fraction as parts per million */
 215         printf("%d.%06d", i, f);
 216 }
 217
 218 #define FMAXINT (4294967296.0)  /* floating point rep. of MAXINT */
 219
 220 static void
 221 p_ntp_time(register const struct l_fixedpt *lfp)
 222 {
 223         register int32_t i;
 224         register u_int32_t uf;
 225         register u_int32_t f;
 226         register float ff;
 227
 228         i = ntohl(lfp->int_part);
 229         uf = ntohl(lfp->fraction);
 230         ff = uf;
 231         if (ff < 0.0)           /* some compilers are buggy */
 232                 ff += FMAXINT;
 233         ff = ff / FMAXINT;      /* shift radix point by 32 bits */
 234         f = ff * 1000000000.0;  /* treat fraction as parts per billion */
 235         printf("%u.%09d", i, f);
 236 }
 237
 238 /* Prints time difference between *lfp and *olfp */
 239 static void
 240 p_ntp_delta(register const struct l_fixedpt *olfp,
 241             register const struct l_fixedpt *lfp)
 242 {
 243         register int32_t i;
 244         register u_int32_t uf;
 245         register u_int32_t ouf;
 246         register u_int32_t f;
 247         register float ff;
 248         int signbit;
 249
 250         i = ntohl(lfp->int_part) - ntohl(olfp->int_part);
 251
 252         uf = ntohl(lfp->fraction);
 253         ouf = ntohl(olfp->fraction);
 254
 255         if (i > 0) {            /* new is definitely greater than old */
 256                 signbit = 0;
 257                 f = uf - ouf;
 258                 if (ouf > uf)   /* must borrow from high-order bits */
 259                         i -= 1;
 260         } else if (i < 0) {     /* new is definitely less than old */
 261                 signbit = 1;
 262                 f = ouf - uf;
 263                 if (uf > ouf)   /* must carry into the high-order bits */
 264                         i += 1;
 265                 i = -i;
 266         } else {                /* int_part is zero */
 267                 if (uf > ouf) {
 268                         signbit = 0;
 269                         f = uf - ouf;
 270                 } else {
 271                         signbit = 1;
 272                         f = ouf - uf;
 273                 }
 274         }
 275
 276         ff = f;
 277         if (ff < 0.0)           /* some compilers are buggy */
 278                 ff += FMAXINT;
 279         ff = ff / FMAXINT;      /* shift radix point by 32 bits */
 280         f = ff * 1000000000.0;  /* treat fraction as parts per billion */
 281         if (signbit)
 282                 putchar('-');
 283         else
 284                 putchar('+');
 285         printf("%d.%09d", i, f);
 286 }