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 1.28 2000-07-01 03:39:07 assar 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 #include <net/if.h>
  42
  43 #include <netinet/in.h>
  44 #include <netinet/if_ether.h>
  45
  46 #include <ctype.h>
  47 #include <stdio.h>
  48 #include <string.h>
  49
  50 #include "interface.h"
  51 #include "addrtoname.h"
  52 #ifdef MODEMASK
  53 #undef MODEMASK                                 /* Solaris sucks */
  54 #endif
  55 #include "ntp.h"
  56
  57 static void p_sfix(const struct s_fixedpt *);
  58 static void p_ntp_time(const struct l_fixedpt *);
  59 static void p_ntp_delta(const struct l_fixedpt *, const struct l_fixedpt *);
  60
  61 /*
  62  * Print ntp requests
  63  */
  64 void
  65 ntp_print(register const u_char *cp, u_int length)
  66 {
  67         register const struct ntpdata *bp;
  68         int mode, version, leapind;
  69         static char rclock[5];
  70
  71         bp = (struct ntpdata *)cp;
  72         /* Note funny sized packets */
  73         if (length != sizeof(struct ntpdata))
  74                 (void)printf(" [len=%d]", length);
  75
  76         TCHECK(bp->status);
  77
  78         version = (int)(bp->status & VERSIONMASK) >> 3;
  79         printf(" v%d", version);
  80
  81         leapind = bp->status & LEAPMASK;
  82         switch (leapind) {
  83
  84         case NO_WARNING:
  85                 break;
  86
  87         case PLUS_SEC:
  88                 fputs(" +1s", stdout);
  89                 break;
  90
  91         case MINUS_SEC:
  92                 fputs(" -1s", stdout);
  93                 break;
  94         }
  95
  96         mode = bp->status & MODEMASK;
  97         switch (mode) {
  98
  99         case MODE_UNSPEC:       /* unspecified */
 100                 fputs(" unspec", stdout);
 101                 break;
 102
 103         case MODE_SYM_ACT:      /* symmetric active */
 104                 fputs(" sym_act", stdout);
 105                 break;
 106
 107         case MODE_SYM_PAS:      /* symmetric passive */
 108                 fputs(" sym_pas", stdout);
 109                 break;
 110
 111         case MODE_CLIENT:       /* client */
 112                 fputs(" client", stdout);
 113                 break;
 114
 115         case MODE_SERVER:       /* server */
 116                 fputs(" server", stdout);
 117                 break;
 118
 119         case MODE_BROADCAST:    /* broadcast */
 120                 fputs(" bcast", stdout);
 121                 break;
 122
 123         case MODE_RES1:         /* reserved */
 124                 fputs(" res1", stdout);
 125                 break;
 126
 127         case MODE_RES2:         /* reserved */
 128                 fputs(" res2", stdout);
 129                 break;
 130
 131         }
 132
 133         TCHECK(bp->stratum);
 134         printf(" strat %d", bp->stratum);
 135
 136         TCHECK(bp->ppoll);
 137         printf(" poll %d", bp->ppoll);
 138
 139         /* Can't TCHECK bp->precision bitfield so bp->distance + 0 instead */
 140         TCHECK2(bp->distance, 0);
 141         printf(" prec %d", bp->precision);
 142
 143         if (!vflag)
 144                 return;
 145
 146         TCHECK(bp->distance);
 147         fputs(" dist ", stdout);
 148         p_sfix(&bp->distance);
 149
 150         TCHECK(bp->dispersion);
 151         fputs(" disp ", stdout);
 152         p_sfix(&bp->dispersion);
 153
 154         TCHECK(bp->refid);
 155         fputs(" ref ", stdout);
 156         /* Interpretation depends on stratum */
 157         switch (bp->stratum) {
 158
 159         case UNSPECIFIED:
 160                 printf("(unspec)");
 161                 break;
 162
 163         case PRIM_REF:
 164                 strncpy(rclock, (char *)&(bp->refid), 4);
 165                 rclock[4] = '\0';
 166                 fputs(rclock, stdout);
 167                 break;
 168
 169         case INFO_QUERY:
 170                 printf("%s INFO_QUERY", ipaddr_string(&(bp->refid)));
 171                 /* this doesn't have more content */
 172                 return;
 173
 174         case INFO_REPLY:
 175                 printf("%s INFO_REPLY", ipaddr_string(&(bp->refid)));
 176                 /* this is too complex to be worth printing */
 177                 return;
 178
 179         default:
 180                 printf("%s", ipaddr_string(&(bp->refid)));
 181                 break;
 182         }
 183
 184         TCHECK(bp->reftime);
 185         putchar('@');
 186         p_ntp_time(&(bp->reftime));
 187
 188         TCHECK(bp->org);
 189         fputs(" orig ", stdout);
 190         p_ntp_time(&(bp->org));
 191
 192         TCHECK(bp->rec);
 193         fputs(" rec ", stdout);
 194         p_ntp_delta(&(bp->org), &(bp->rec));
 195
 196         TCHECK(bp->xmt);
 197         fputs(" xmt ", stdout);
 198         p_ntp_delta(&(bp->org), &(bp->xmt));
 199
 200         return;
 201
 202 trunc:
 203         fputs(" [|ntp]", stdout);
 204 }
 205
 206 static void
 207 p_sfix(register const struct s_fixedpt *sfp)
 208 {
 209         register int i;
 210         register int f;
 211         register float ff;
 212
 213         i = ntohs(sfp->int_part);
 214         f = ntohs(sfp->fraction);
 215         ff = f / 65536.0;       /* shift radix point by 16 bits */
 216         f = ff * 1000000.0;     /* Treat fraction as parts per million */
 217         printf("%d.%06d", i, f);
 218 }
 219
 220 #define FMAXINT (4294967296.0)  /* floating point rep. of MAXINT */
 221
 222 static void
 223 p_ntp_time(register const struct l_fixedpt *lfp)
 224 {
 225         register int32_t i;
 226         register u_int32_t uf;
 227         register u_int32_t f;
 228         register float ff;
 229
 230         i = ntohl(lfp->int_part);
 231         uf = ntohl(lfp->fraction);
 232         ff = uf;
 233         if (ff < 0.0)           /* some compilers are buggy */
 234                 ff += FMAXINT;
 235         ff = ff / FMAXINT;      /* shift radix point by 32 bits */
 236         f = ff * 1000000000.0;  /* treat fraction as parts per billion */
 237         printf("%u.%09d", i, f);
 238 }
 239
 240 /* Prints time difference between *lfp and *olfp */
 241 static void
 242 p_ntp_delta(register const struct l_fixedpt *olfp,
 243             register const struct l_fixedpt *lfp)
 244 {
 245         register int32_t i;
 246         register u_int32_t uf;
 247         register u_int32_t ouf;
 248         register u_int32_t f;
 249         register float ff;
 250         int signbit;
 251
 252         i = ntohl(lfp->int_part) - ntohl(olfp->int_part);
 253
 254         uf = ntohl(lfp->fraction);
 255         ouf = ntohl(olfp->fraction);
 256
 257         if (i > 0) {            /* new is definitely greater than old */
 258                 signbit = 0;
 259                 f = uf - ouf;
 260                 if (ouf > uf)   /* must borrow from high-order bits */
 261                         i -= 1;
 262         } else if (i < 0) {     /* new is definitely less than old */
 263                 signbit = 1;
 264                 f = ouf - uf;
 265                 if (uf > ouf)   /* must carry into the high-order bits */
 266                         i += 1;
 267                 i = -i;
 268         } else {                /* int_part is zero */
 269                 if (uf > ouf) {
 270                         signbit = 0;
 271                         f = uf - ouf;
 272                 } else {
 273                         signbit = 1;
 274                         f = ouf - uf;
 275                 }
 276         }
 277
 278         ff = f;
 279         if (ff < 0.0)           /* some compilers are buggy */
 280                 ff += FMAXINT;
 281         ff = ff / FMAXINT;      /* shift radix point by 32 bits */
 282         f = ff * 1000000000.0;  /* treat fraction as parts per billion */
 283         if (signbit)
 284                 putchar('-');
 285         else
 286                 putchar('+');
 287         printf("%d.%09d", i, f);
 288 }