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 1.31 2000-10-06 04:23:13 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 #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         static char rclock[5];
  65
  66         bp = (struct ntpdata *)cp;
  67         /* Note funny sized packets */
  68         if (length != sizeof(struct ntpdata))
  69                 (void)printf(" [len=%d]", length);
  70
  71         TCHECK(bp->status);
  72
  73         version = (int)(bp->status & VERSIONMASK) >> 3;
  74         printf(" v%d", version);
  75
  76         leapind = bp->status & LEAPMASK;
  77         switch (leapind) {
  78
  79         case NO_WARNING:
  80                 break;
  81
  82         case PLUS_SEC:
  83                 fputs(" +1s", stdout);
  84                 break;
  85
  86         case MINUS_SEC:
  87                 fputs(" -1s", stdout);
  88                 break;
  89         }
  90
  91         mode = bp->status & MODEMASK;
  92         switch (mode) {
  93
  94         case MODE_UNSPEC:       /* unspecified */
  95                 fputs(" unspec", stdout);
  96                 break;
  97
  98         case MODE_SYM_ACT:      /* symmetric active */
  99                 fputs(" sym_act", stdout);
 100                 break;
 101
 102         case MODE_SYM_PAS:      /* symmetric passive */
 103                 fputs(" sym_pas", stdout);
 104                 break;
 105
 106         case MODE_CLIENT:       /* client */
 107                 fputs(" client", stdout);
 108                 break;
 109
 110         case MODE_SERVER:       /* server */
 111                 fputs(" server", stdout);
 112                 break;
 113
 114         case MODE_BROADCAST:    /* broadcast */
 115                 fputs(" bcast", stdout);
 116                 break;
 117
 118         case MODE_RES1:         /* reserved */
 119                 fputs(" res1", stdout);
 120                 break;
 121
 122         case MODE_RES2:         /* reserved */
 123                 fputs(" res2", stdout);
 124                 break;
 125
 126         }
 127
 128         TCHECK(bp->stratum);
 129         printf(" strat %d", bp->stratum);
 130
 131         TCHECK(bp->ppoll);
 132         printf(" poll %d", bp->ppoll);
 133
 134         /* Can't TCHECK bp->precision bitfield so bp->distance + 0 instead */
 135         TCHECK2(bp->distance, 0);
 136         printf(" prec %d", bp->precision);
 137
 138         if (!vflag)
 139                 return;
 140
 141         TCHECK(bp->distance);
 142         fputs(" dist ", stdout);
 143         p_sfix(&bp->distance);
 144
 145         TCHECK(bp->dispersion);
 146         fputs(" disp ", stdout);
 147         p_sfix(&bp->dispersion);
 148
 149         TCHECK(bp->refid);
 150         fputs(" ref ", stdout);
 151         /* Interpretation depends on stratum */
 152         switch (bp->stratum) {
 153
 154         case UNSPECIFIED:
 155                 printf("(unspec)");
 156                 break;
 157
 158         case PRIM_REF:
 159                 strncpy(rclock, (char *)&(bp->refid), 4);
 160                 rclock[4] = '\0';
 161                 fputs(rclock, stdout);
 162                 break;
 163
 164         case INFO_QUERY:
 165                 printf("%s INFO_QUERY", ipaddr_string(&(bp->refid)));
 166                 /* this doesn't have more content */
 167                 return;
 168
 169         case INFO_REPLY:
 170                 printf("%s INFO_REPLY", ipaddr_string(&(bp->refid)));
 171                 /* this is too complex to be worth printing */
 172                 return;
 173
 174         default:
 175                 printf("%s", ipaddr_string(&(bp->refid)));
 176                 break;
 177         }
 178
 179         TCHECK(bp->reftime);
 180         putchar('@');
 181         p_ntp_time(&(bp->reftime));
 182
 183         TCHECK(bp->org);
 184         fputs(" orig ", stdout);
 185         p_ntp_time(&(bp->org));
 186
 187         TCHECK(bp->rec);
 188         fputs(" rec ", stdout);
 189         p_ntp_delta(&(bp->org), &(bp->rec));
 190
 191         TCHECK(bp->xmt);
 192         fputs(" xmt ", stdout);
 193         p_ntp_delta(&(bp->org), &(bp->xmt));
 194
 195         return;
 196
 197 trunc:
 198         fputs(" [|ntp]", stdout);
 199 }
 200
 201 static void
 202 p_sfix(register const struct s_fixedpt *sfp)
 203 {
 204         register int i;
 205         register int f;
 206         register float ff;
 207
 208         i = ntohs(sfp->int_part);
 209         f = ntohs(sfp->fraction);
 210         ff = f / 65536.0;       /* shift radix point by 16 bits */
 211         f = ff * 1000000.0;     /* Treat fraction as parts per million */
 212         printf("%d.%06d", i, f);
 213 }
 214
 215 #define FMAXINT (4294967296.0)  /* floating point rep. of MAXINT */
 216
 217 static void
 218 p_ntp_time(register const struct l_fixedpt *lfp)
 219 {
 220         register int32_t i;
 221         register u_int32_t uf;
 222         register u_int32_t f;
 223         register float ff;
 224
 225         i = ntohl(lfp->int_part);
 226         uf = ntohl(lfp->fraction);
 227         ff = uf;
 228         if (ff < 0.0)           /* some compilers are buggy */
 229                 ff += FMAXINT;
 230         ff = ff / FMAXINT;      /* shift radix point by 32 bits */
 231         f = ff * 1000000000.0;  /* treat fraction as parts per billion */
 232         printf("%u.%09d", i, f);
 233 }
 234
 235 /* Prints time difference between *lfp and *olfp */
 236 static void
 237 p_ntp_delta(register const struct l_fixedpt *olfp,
 238             register const struct l_fixedpt *lfp)
 239 {
 240         register int32_t i;
 241         register u_int32_t uf;
 242         register u_int32_t ouf;
 243         register u_int32_t f;
 244         register float ff;
 245         int signbit;
 246
 247         i = ntohl(lfp->int_part) - ntohl(olfp->int_part);
 248
 249         uf = ntohl(lfp->fraction);
 250         ouf = ntohl(olfp->fraction);
 251
 252         if (i > 0) {            /* new is definitely greater than old */
 253                 signbit = 0;
 254                 f = uf - ouf;
 255                 if (ouf > uf)   /* must borrow from high-order bits */
 256                         i -= 1;
 257         } else if (i < 0) {     /* new is definitely less than old */
 258                 signbit = 1;
 259                 f = ouf - uf;
 260                 if (uf > ouf)   /* must carry into the high-order bits */
 261                         i += 1;
 262                 i = -i;
 263         } else {                /* int_part is zero */
 264                 if (uf > ouf) {
 265                         signbit = 0;
 266                         f = uf - ouf;
 267                 } else {
 268                         signbit = 1;
 269                         f = ouf - uf;
 270                 }
 271         }
 272
 273         ff = f;
 274         if (ff < 0.0)           /* some compilers are buggy */
 275                 ff += FMAXINT;
 276         ff = ff / FMAXINT;      /* shift radix point by 32 bits */
 277         f = ff * 1000000000.0;  /* treat fraction as parts per billion */
 278         if (signbit)
 279                 putchar('-');
 280         else
 281                 putchar('+');
 282         printf("%d.%09d", i, f);
 283 }