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 1.29 2000-09-23 08:03:38 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 #include <net/if.h>
  42
  43 #include <netinet/in.h>
  44
  45 #include <ctype.h>
  46 #include <stdio.h>
  47 #include <string.h>
  48
  49 #include "interface.h"
  50 #include "addrtoname.h"
  51 #ifdef MODEMASK
  52 #undef MODEMASK                                 /* Solaris sucks */
  53 #endif
  54 #include "ntp.h"
  55
  56 static void p_sfix(const struct s_fixedpt *);
  57 static void p_ntp_time(const struct l_fixedpt *);
  58 static void p_ntp_delta(const struct l_fixedpt *, const struct l_fixedpt *);
  59
  60 /*
  61  * Print ntp requests
  62  */
  63 void
  64 ntp_print(register const u_char *cp, u_int length)
  65 {
  66         register const struct ntpdata *bp;
  67         int mode, version, leapind;
  68         static char rclock[5];
  69
  70         bp = (struct ntpdata *)cp;
  71         /* Note funny sized packets */
  72         if (length != sizeof(struct ntpdata))
  73                 (void)printf(" [len=%d]", length);
  74
  75         TCHECK(bp->status);
  76
  77         version = (int)(bp->status & VERSIONMASK) >> 3;
  78         printf(" v%d", version);
  79
  80         leapind = bp->status & LEAPMASK;
  81         switch (leapind) {
  82
  83         case NO_WARNING:
  84                 break;
  85
  86         case PLUS_SEC:
  87                 fputs(" +1s", stdout);
  88                 break;
  89
  90         case MINUS_SEC:
  91                 fputs(" -1s", stdout);
  92                 break;
  93         }
  94
  95         mode = bp->status & MODEMASK;
  96         switch (mode) {
  97
  98         case MODE_UNSPEC:       /* unspecified */
  99                 fputs(" unspec", stdout);
 100                 break;
 101
 102         case MODE_SYM_ACT:      /* symmetric active */
 103                 fputs(" sym_act", stdout);
 104                 break;
 105
 106         case MODE_SYM_PAS:      /* symmetric passive */
 107                 fputs(" sym_pas", stdout);
 108                 break;
 109
 110         case MODE_CLIENT:       /* client */
 111                 fputs(" client", stdout);
 112                 break;
 113
 114         case MODE_SERVER:       /* server */
 115                 fputs(" server", stdout);
 116                 break;
 117
 118         case MODE_BROADCAST:    /* broadcast */
 119                 fputs(" bcast", stdout);
 120                 break;
 121
 122         case MODE_RES1:         /* reserved */
 123                 fputs(" res1", stdout);
 124                 break;
 125
 126         case MODE_RES2:         /* reserved */
 127                 fputs(" res2", stdout);
 128                 break;
 129
 130         }
 131
 132         TCHECK(bp->stratum);
 133         printf(" strat %d", bp->stratum);
 134
 135         TCHECK(bp->ppoll);
 136         printf(" poll %d", bp->ppoll);
 137
 138         /* Can't TCHECK bp->precision bitfield so bp->distance + 0 instead */
 139         TCHECK2(bp->distance, 0);
 140         printf(" prec %d", bp->precision);
 141
 142         if (!vflag)
 143                 return;
 144
 145         TCHECK(bp->distance);
 146         fputs(" dist ", stdout);
 147         p_sfix(&bp->distance);
 148
 149         TCHECK(bp->dispersion);
 150         fputs(" disp ", stdout);
 151         p_sfix(&bp->dispersion);
 152
 153         TCHECK(bp->refid);
 154         fputs(" ref ", stdout);
 155         /* Interpretation depends on stratum */
 156         switch (bp->stratum) {
 157
 158         case UNSPECIFIED:
 159                 printf("(unspec)");
 160                 break;
 161
 162         case PRIM_REF:
 163                 strncpy(rclock, (char *)&(bp->refid), 4);
 164                 rclock[4] = '\0';
 165                 fputs(rclock, stdout);
 166                 break;
 167
 168         case INFO_QUERY:
 169                 printf("%s INFO_QUERY", ipaddr_string(&(bp->refid)));
 170                 /* this doesn't have more content */
 171                 return;
 172
 173         case INFO_REPLY:
 174                 printf("%s INFO_REPLY", ipaddr_string(&(bp->refid)));
 175                 /* this is too complex to be worth printing */
 176                 return;
 177
 178         default:
 179                 printf("%s", ipaddr_string(&(bp->refid)));
 180                 break;
 181         }
 182
 183         TCHECK(bp->reftime);
 184         putchar('@');
 185         p_ntp_time(&(bp->reftime));
 186
 187         TCHECK(bp->org);
 188         fputs(" orig ", stdout);
 189         p_ntp_time(&(bp->org));
 190
 191         TCHECK(bp->rec);
 192         fputs(" rec ", stdout);
 193         p_ntp_delta(&(bp->org), &(bp->rec));
 194
 195         TCHECK(bp->xmt);
 196         fputs(" xmt ", stdout);
 197         p_ntp_delta(&(bp->org), &(bp->xmt));
 198
 199         return;
 200
 201 trunc:
 202         fputs(" [|ntp]", stdout);
 203 }
 204
 205 static void
 206 p_sfix(register const struct s_fixedpt *sfp)
 207 {
 208         register int i;
 209         register int f;
 210         register float ff;
 211
 212         i = ntohs(sfp->int_part);
 213         f = ntohs(sfp->fraction);
 214         ff = f / 65536.0;       /* shift radix point by 16 bits */
 215         f = ff * 1000000.0;     /* Treat fraction as parts per million */
 216         printf("%d.%06d", i, f);
 217 }
 218
 219 #define FMAXINT (4294967296.0)  /* floating point rep. of MAXINT */
 220
 221 static void
 222 p_ntp_time(register const struct l_fixedpt *lfp)
 223 {
 224         register int32_t i;
 225         register u_int32_t uf;
 226         register u_int32_t f;
 227         register float ff;
 228
 229         i = ntohl(lfp->int_part);
 230         uf = ntohl(lfp->fraction);
 231         ff = uf;
 232         if (ff < 0.0)           /* some compilers are buggy */
 233                 ff += FMAXINT;
 234         ff = ff / FMAXINT;      /* shift radix point by 32 bits */
 235         f = ff * 1000000000.0;  /* treat fraction as parts per billion */
 236         printf("%u.%09d", i, f);
 237 }
 238
 239 /* Prints time difference between *lfp and *olfp */
 240 static void
 241 p_ntp_delta(register const struct l_fixedpt *olfp,
 242             register const struct l_fixedpt *lfp)
 243 {
 244         register int32_t i;
 245         register u_int32_t uf;
 246         register u_int32_t ouf;
 247         register u_int32_t f;
 248         register float ff;
 249         int signbit;
 250
 251         i = ntohl(lfp->int_part) - ntohl(olfp->int_part);
 252
 253         uf = ntohl(lfp->fraction);
 254         ouf = ntohl(olfp->fraction);
 255
 256         if (i > 0) {            /* new is definitely greater than old */
 257                 signbit = 0;
 258                 f = uf - ouf;
 259                 if (ouf > uf)   /* must borrow from high-order bits */
 260                         i -= 1;
 261         } else if (i < 0) {     /* new is definitely less than old */
 262                 signbit = 1;
 263                 f = ouf - uf;
 264                 if (uf > ouf)   /* must carry into the high-order bits */
 265                         i += 1;
 266                 i = -i;
 267         } else {                /* int_part is zero */
 268                 if (uf > ouf) {
 269                         signbit = 0;
 270                         f = uf - ouf;
 271                 } else {
 272                         signbit = 1;
 273                         f = ouf - uf;
 274                 }
 275         }
 276
 277         ff = f;
 278         if (ff < 0.0)           /* some compilers are buggy */
 279                 ff += FMAXINT;
 280         ff = ff / FMAXINT;      /* shift radix point by 32 bits */
 281         f = ff * 1000000000.0;  /* treat fraction as parts per billion */
 282         if (signbit)
 283                 putchar('-');
 284         else
 285                 putchar('+');
 286         printf("%d.%09d", i, f);
 287 }