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 1.27 1999-11-21 09:36:57 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 #if __STDC__
  40 struct mbuf;
  41 struct rtentry;
  42 #endif
  43 #include <net/if.h>
  44
  45 #include <netinet/in.h>
  46 #include <netinet/if_ether.h>
  47
  48 #include <ctype.h>
  49 #include <stdio.h>
  50 #include <string.h>
  51
  52 #include "interface.h"
  53 #include "addrtoname.h"
  54 #ifdef MODEMASK
  55 #undef MODEMASK                                 /* Solaris sucks */
  56 #endif
  57 #include "ntp.h"
  58
  59 static void p_sfix(const struct s_fixedpt *);
  60 static void p_ntp_time(const struct l_fixedpt *);
  61 static void p_ntp_delta(const struct l_fixedpt *, const struct l_fixedpt *);
  62
  63 /*
  64  * Print ntp requests
  65  */
  66 void
  67 ntp_print(register const u_char *cp, u_int length)
  68 {
  69         register const struct ntpdata *bp;
  70         int mode, version, leapind;
  71         static char rclock[5];
  72
  73         bp = (struct ntpdata *)cp;
  74         /* Note funny sized packets */
  75         if (length != sizeof(struct ntpdata))
  76                 (void)printf(" [len=%d]", length);
  77
  78         TCHECK(bp->status);
  79
  80         version = (int)(bp->status & VERSIONMASK) >> 3;
  81         printf(" v%d", version);
  82
  83         leapind = bp->status & LEAPMASK;
  84         switch (leapind) {
  85
  86         case NO_WARNING:
  87                 break;
  88
  89         case PLUS_SEC:
  90                 fputs(" +1s", stdout);
  91                 break;
  92
  93         case MINUS_SEC:
  94                 fputs(" -1s", stdout);
  95                 break;
  96         }
  97
  98         mode = bp->status & MODEMASK;
  99         switch (mode) {
 100
 101         case MODE_UNSPEC:       /* unspecified */
 102                 fputs(" unspec", stdout);
 103                 break;
 104
 105         case MODE_SYM_ACT:      /* symmetric active */
 106                 fputs(" sym_act", stdout);
 107                 break;
 108
 109         case MODE_SYM_PAS:      /* symmetric passive */
 110                 fputs(" sym_pas", stdout);
 111                 break;
 112
 113         case MODE_CLIENT:       /* client */
 114                 fputs(" client", stdout);
 115                 break;
 116
 117         case MODE_SERVER:       /* server */
 118                 fputs(" server", stdout);
 119                 break;
 120
 121         case MODE_BROADCAST:    /* broadcast */
 122                 fputs(" bcast", stdout);
 123                 break;
 124
 125         case MODE_RES1:         /* reserved */
 126                 fputs(" res1", stdout);
 127                 break;
 128
 129         case MODE_RES2:         /* reserved */
 130                 fputs(" res2", stdout);
 131                 break;
 132
 133         }
 134
 135         TCHECK(bp->stratum);
 136         printf(" strat %d", bp->stratum);
 137
 138         TCHECK(bp->ppoll);
 139         printf(" poll %d", bp->ppoll);
 140
 141         /* Can't TCHECK bp->precision bitfield so bp->distance + 0 instead */
 142         TCHECK2(bp->distance, 0);
 143         printf(" prec %d", bp->precision);
 144
 145         if (!vflag)
 146                 return;
 147
 148         TCHECK(bp->distance);
 149         fputs(" dist ", stdout);
 150         p_sfix(&bp->distance);
 151
 152         TCHECK(bp->dispersion);
 153         fputs(" disp ", stdout);
 154         p_sfix(&bp->dispersion);
 155
 156         TCHECK(bp->refid);
 157         fputs(" ref ", stdout);
 158         /* Interpretation depends on stratum */
 159         switch (bp->stratum) {
 160
 161         case UNSPECIFIED:
 162                 printf("(unspec)");
 163                 break;
 164
 165         case PRIM_REF:
 166                 strncpy(rclock, (char *)&(bp->refid), 4);
 167                 rclock[4] = '\0';
 168                 fputs(rclock, stdout);
 169                 break;
 170
 171         case INFO_QUERY:
 172                 printf("%s INFO_QUERY", ipaddr_string(&(bp->refid)));
 173                 /* this doesn't have more content */
 174                 return;
 175
 176         case INFO_REPLY:
 177                 printf("%s INFO_REPLY", ipaddr_string(&(bp->refid)));
 178                 /* this is too complex to be worth printing */
 179                 return;
 180
 181         default:
 182                 printf("%s", ipaddr_string(&(bp->refid)));
 183                 break;
 184         }
 185
 186         TCHECK(bp->reftime);
 187         putchar('@');
 188         p_ntp_time(&(bp->reftime));
 189
 190         TCHECK(bp->org);
 191         fputs(" orig ", stdout);
 192         p_ntp_time(&(bp->org));
 193
 194         TCHECK(bp->rec);
 195         fputs(" rec ", stdout);
 196         p_ntp_delta(&(bp->org), &(bp->rec));
 197
 198         TCHECK(bp->xmt);
 199         fputs(" xmt ", stdout);
 200         p_ntp_delta(&(bp->org), &(bp->xmt));
 201
 202         return;
 203
 204 trunc:
 205         fputs(" [|ntp]", stdout);
 206 }
 207
 208 static void
 209 p_sfix(register const struct s_fixedpt *sfp)
 210 {
 211         register int i;
 212         register int f;
 213         register float ff;
 214
 215         i = ntohs(sfp->int_part);
 216         f = ntohs(sfp->fraction);
 217         ff = f / 65536.0;       /* shift radix point by 16 bits */
 218         f = ff * 1000000.0;     /* Treat fraction as parts per million */
 219         printf("%d.%06d", i, f);
 220 }
 221
 222 #define FMAXINT (4294967296.0)  /* floating point rep. of MAXINT */
 223
 224 static void
 225 p_ntp_time(register const struct l_fixedpt *lfp)
 226 {
 227         register int32_t i;
 228         register u_int32_t uf;
 229         register u_int32_t f;
 230         register float ff;
 231
 232         i = ntohl(lfp->int_part);
 233         uf = ntohl(lfp->fraction);
 234         ff = uf;
 235         if (ff < 0.0)           /* some compilers are buggy */
 236                 ff += FMAXINT;
 237         ff = ff / FMAXINT;      /* shift radix point by 32 bits */
 238         f = ff * 1000000000.0;  /* treat fraction as parts per billion */
 239         printf("%u.%09d", i, f);
 240 }
 241
 242 /* Prints time difference between *lfp and *olfp */
 243 static void
 244 p_ntp_delta(register const struct l_fixedpt *olfp,
 245             register const struct l_fixedpt *lfp)
 246 {
 247         register int32_t i;
 248         register u_int32_t uf;
 249         register u_int32_t ouf;
 250         register u_int32_t f;
 251         register float ff;
 252         int signbit;
 253
 254         i = ntohl(lfp->int_part) - ntohl(olfp->int_part);
 255
 256         uf = ntohl(lfp->fraction);
 257         ouf = ntohl(olfp->fraction);
 258
 259         if (i > 0) {            /* new is definitely greater than old */
 260                 signbit = 0;
 261                 f = uf - ouf;
 262                 if (ouf > uf)   /* must borrow from high-order bits */
 263                         i -= 1;
 264         } else if (i < 0) {     /* new is definitely less than old */
 265                 signbit = 1;
 266                 f = ouf - uf;
 267                 if (uf > ouf)   /* must carry into the high-order bits */
 268                         i += 1;
 269                 i = -i;
 270         } else {                /* int_part is zero */
 271                 if (uf > ouf) {
 272                         signbit = 0;
 273                         f = uf - ouf;
 274                 } else {
 275                         signbit = 1;
 276                         f = ouf - uf;
 277                 }
 278         }
 279
 280         ff = f;
 281         if (ff < 0.0)           /* some compilers are buggy */
 282                 ff += FMAXINT;
 283         ff = ff / FMAXINT;      /* shift radix point by 32 bits */
 284         f = ff * 1000000000.0;  /* treat fraction as parts per billion */
 285         if (signbit)
 286                 putchar('-');
 287         else
 288                 putchar('+');
 289         printf("%d.%09d", i, f);
 290 }