contrib/tcpdump/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[] _U_ =
  28     "@(#) $Header: /tcpdump/master/tcpdump/print-ntp.c,v 1.42 2005-05-06 07:56:53 guy Exp $ (LBL)";
  29 #endif
  30
  31 #ifdef HAVE_CONFIG_H
  32 #include "config.h"
  33 #endif
  34
  35 #include <tcpdump-stdinc.h>
  36
  37 #include <stdio.h>
  38 #include <string.h>
  39 #ifdef HAVE_STRFTIME
  40 #include <time.h>
  41 #endif
  42
  43 #include "interface.h"
  44 #include "addrtoname.h"
  45 #include "extract.h"
  46 #ifdef MODEMASK
  47 #undef MODEMASK                                 /* Solaris sucks */
  48 #endif
  49 #include "ntp.h"
  50
  51 static void p_sfix(const struct s_fixedpt *);
  52 static void p_ntp_time(const struct l_fixedpt *);
  53 static void p_ntp_delta(const struct l_fixedpt *, const struct l_fixedpt *);
  54
  55 static struct tok ntp_mode_values[] = {
  56     { MODE_UNSPEC,    "unspecified" },
  57     { MODE_SYM_ACT,   "symmetric active" },
  58     { MODE_SYM_PAS,   "symmetric passive" },
  59     { MODE_CLIENT,    "Client" },
  60     { MODE_SERVER,    "Server" },
  61     { MODE_BROADCAST, "Broadcast" },
  62     { MODE_RES1,      "Reserved" },
  63     { MODE_RES2,      "Reserved" },
  64     { 0, NULL }
  65 };
  66
  67 static struct tok ntp_leapind_values[] = {
  68     { NO_WARNING,     "" },
  69     { PLUS_SEC,       "+1s" },
  70     { MINUS_SEC,      "-1s" },
  71     { ALARM,          "clock unsynchronized" },
  72     { 0, NULL }
  73 };
  74
  75 /*
  76  * Print ntp requests
  77  */
  78 void
  79 ntp_print(register const u_char *cp, u_int length)
  80 {
  81         register const struct ntpdata *bp;
  82         int mode, version, leapind;
  83
  84         bp = (struct ntpdata *)cp;
  85
  86         TCHECK(bp->status);
  87
  88         version = (int)(bp->status & VERSIONMASK) >> 3;
  89         printf("NTPv%d", version);
  90
  91         mode = bp->status & MODEMASK;
  92         if (!vflag) {
  93             printf (", %s, length %u",
  94                     tok2str(ntp_mode_values, "Unknown mode", mode),
  95                     length);
  96             return;
  97         }
  98
  99         printf (", length %u\n\t%s",
 100                 length,
 101                 tok2str(ntp_mode_values, "Unknown mode", mode));
 102
 103         leapind = bp->status & LEAPMASK;
 104         printf (", Leap indicator: %s (%u)",
 105                 tok2str(ntp_leapind_values, "Unknown", leapind),
 106                 leapind);
 107
 108         TCHECK(bp->stratum);
 109         printf(", Stratum %u", bp->stratum);
 110
 111         TCHECK(bp->ppoll);
 112         printf(", poll %us", bp->ppoll);
 113
 114         /* Can't TCHECK bp->precision bitfield so bp->distance + 0 instead */
 115         TCHECK2(bp->root_delay, 0);
 116         printf(", precision %d", bp->precision);
 117
 118         TCHECK(bp->root_delay);
 119         fputs("\n\tRoot Delay: ", stdout);
 120         p_sfix(&bp->root_delay);
 121
 122         TCHECK(bp->root_dispersion);
 123         fputs(", Root dispersion: ", stdout);
 124         p_sfix(&bp->root_dispersion);
 125
 126         TCHECK(bp->refid);
 127         fputs(", Reference-ID: ", stdout);
 128         /* Interpretation depends on stratum */
 129         switch (bp->stratum) {
 130
 131         case UNSPECIFIED:
 132                 printf("(unspec)");
 133                 break;
 134
 135         case PRIM_REF:
 136                 if (fn_printn((u_char *)&(bp->refid), 4, snapend))
 137                         goto trunc;
 138                 break;
 139
 140         case INFO_QUERY:
 141                 printf("%s INFO_QUERY", ipaddr_string(&(bp->refid)));
 142                 /* this doesn't have more content */
 143                 return;
 144
 145         case INFO_REPLY:
 146                 printf("%s INFO_REPLY", ipaddr_string(&(bp->refid)));
 147                 /* this is too complex to be worth printing */
 148                 return;
 149
 150         default:
 151                 printf("%s", ipaddr_string(&(bp->refid)));
 152                 break;
 153         }
 154
 155         TCHECK(bp->ref_timestamp);
 156         fputs("\n\t  Reference Timestamp:  ", stdout);
 157         p_ntp_time(&(bp->ref_timestamp));
 158
 159         TCHECK(bp->org_timestamp);
 160         fputs("\n\t  Originator Timestamp: ", stdout);
 161         p_ntp_time(&(bp->org_timestamp));
 162
 163         TCHECK(bp->rec_timestamp);
 164         fputs("\n\t  Receive Timestamp:    ", stdout);
 165         p_ntp_time(&(bp->rec_timestamp));
 166
 167         TCHECK(bp->xmt_timestamp);
 168         fputs("\n\t  Transmit Timestamp:   ", stdout);
 169         p_ntp_time(&(bp->xmt_timestamp));
 170
 171         fputs("\n\t    Originator - Receive Timestamp:  ", stdout);
 172         p_ntp_delta(&(bp->org_timestamp), &(bp->rec_timestamp));
 173
 174         fputs("\n\t    Originator - Transmit Timestamp: ", stdout);
 175         p_ntp_delta(&(bp->org_timestamp), &(bp->xmt_timestamp));
 176
 177         /* FIXME key-id, authentication */
 178
 179         return;
 180
 181 trunc:
 182         fputs(" [|ntp]", stdout);
 183 }
 184
 185 static void
 186 p_sfix(register const struct s_fixedpt *sfp)
 187 {
 188         register int i;
 189         register int f;
 190         register float ff;
 191
 192         i = EXTRACT_16BITS(&sfp->int_part);
 193         f = EXTRACT_16BITS(&sfp->fraction);
 194         ff = f / 65536.0;       /* shift radix point by 16 bits */
 195         f = ff * 1000000.0;     /* Treat fraction as parts per million */
 196         printf("%d.%06d", i, f);
 197 }
 198
 199 #define FMAXINT (4294967296.0)  /* floating point rep. of MAXINT */
 200
 201 static void
 202 p_ntp_time(register const struct l_fixedpt *lfp)
 203 {
 204         register int32_t i;
 205         register u_int32_t uf;
 206         register u_int32_t f;
 207         register float ff;
 208
 209         i = EXTRACT_32BITS(&lfp->int_part);
 210         uf = EXTRACT_32BITS(&lfp->fraction);
 211         ff = uf;
 212         if (ff < 0.0)           /* some compilers are buggy */
 213                 ff += FMAXINT;
 214         ff = ff / FMAXINT;      /* shift radix point by 32 bits */
 215         f = ff * 1000000000.0;  /* treat fraction as parts per billion */
 216         printf("%u.%09d", i, f);
 217
 218 #ifdef HAVE_STRFTIME
 219         /*
 220          * print the time in human-readable format.
 221          */
 222         if (i) {
 223             time_t seconds = i - JAN_1970;
 224             struct tm *tm;
 225             char time_buf[128];
 226
 227             tm = localtime(&seconds);
 228             strftime(time_buf, sizeof (time_buf), "%Y/%m/%d %H:%M:%S", tm);
 229             printf (" (%s)", time_buf);
 230         }
 231 #endif
 232 }
 233
 234 /* Prints time difference between *lfp and *olfp */
 235 static void
 236 p_ntp_delta(register const struct l_fixedpt *olfp,
 237             register const struct l_fixedpt *lfp)
 238 {
 239         register int32_t i;
 240         register u_int32_t u, uf;
 241         register u_int32_t ou, ouf;
 242         register u_int32_t f;
 243         register float ff;
 244         int signbit;
 245
 246         u = EXTRACT_32BITS(&lfp->int_part);
 247         ou = EXTRACT_32BITS(&olfp->int_part);
 248         uf = EXTRACT_32BITS(&lfp->fraction);
 249         ouf = EXTRACT_32BITS(&olfp->fraction);
 250         if (ou == 0 && ouf == 0) {
 251                 p_ntp_time(lfp);
 252                 return;
 253         }
 254
 255         i = u - ou;
 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 }
 289