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[] _U_ =
  28     "@(#) $Header: /tcpdump/master/tcpdump/print-ntp.c,v 1.43 2007-11-30 13:45:10 hannes 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 static struct tok ntp_stratum_values[] = {
  76         { UNSPECIFIED,  "unspecified" },
  77         { PRIM_REF,     "primary reference" },
  78         { 0, NULL }
  79 };
  80
  81 /*
  82  * Print ntp requests
  83  */
  84 void
  85 ntp_print(register const u_char *cp, u_int length)
  86 {
  87         register const struct ntpdata *bp;
  88         int mode, version, leapind;
  89
  90         bp = (struct ntpdata *)cp;
  91
  92         TCHECK(bp->status);
  93
  94         version = (int)(bp->status & VERSIONMASK) >> 3;
  95         printf("NTPv%d", version);
  96
  97         mode = bp->status & MODEMASK;
  98         if (!vflag) {
  99             printf (", %s, length %u",
 100                     tok2str(ntp_mode_values, "Unknown mode", mode),
 101                     length);
 102             return;
 103         }
 104
 105         printf (", length %u\n\t%s",
 106                 length,
 107                 tok2str(ntp_mode_values, "Unknown mode", mode));
 108
 109         leapind = bp->status & LEAPMASK;
 110         printf (", Leap indicator: %s (%u)",
 111                 tok2str(ntp_leapind_values, "Unknown", leapind),
 112                 leapind);
 113
 114         TCHECK(bp->stratum);
 115         printf(", Stratum %u (%s)",
 116                 bp->stratum,
 117                 tok2str(ntp_stratum_values, (bp->stratum >=2 && bp->stratum<=15) ? "secondary reference" : "reserved", bp->stratum));
 118
 119         TCHECK(bp->ppoll);
 120         printf(", poll %u (%us)", bp->ppoll, 1 << bp->ppoll);
 121
 122         /* Can't TCHECK bp->precision bitfield so bp->distance + 0 instead */
 123         TCHECK2(bp->root_delay, 0);
 124         printf(", precision %d", bp->precision);
 125
 126         TCHECK(bp->root_delay);
 127         fputs("\n\tRoot Delay: ", stdout);
 128         p_sfix(&bp->root_delay);
 129
 130         TCHECK(bp->root_dispersion);
 131         fputs(", Root dispersion: ", stdout);
 132         p_sfix(&bp->root_dispersion);
 133
 134         TCHECK(bp->refid);
 135         fputs(", Reference-ID: ", stdout);
 136         /* Interpretation depends on stratum */
 137         switch (bp->stratum) {
 138
 139         case UNSPECIFIED:
 140                 printf("(unspec)");
 141                 break;
 142
 143         case PRIM_REF:
 144                 if (fn_printn((u_char *)&(bp->refid), 4, snapend))
 145                         goto trunc;
 146                 break;
 147
 148         case INFO_QUERY:
 149                 printf("%s INFO_QUERY", ipaddr_string(&(bp->refid)));
 150                 /* this doesn't have more content */
 151                 return;
 152
 153         case INFO_REPLY:
 154                 printf("%s INFO_REPLY", ipaddr_string(&(bp->refid)));
 155                 /* this is too complex to be worth printing */
 156                 return;
 157
 158         default:
 159                 printf("%s", ipaddr_string(&(bp->refid)));
 160                 break;
 161         }
 162
 163         TCHECK(bp->ref_timestamp);
 164         fputs("\n\t  Reference Timestamp:  ", stdout);
 165         p_ntp_time(&(bp->ref_timestamp));
 166
 167         TCHECK(bp->org_timestamp);
 168         fputs("\n\t  Originator Timestamp: ", stdout);
 169         p_ntp_time(&(bp->org_timestamp));
 170
 171         TCHECK(bp->rec_timestamp);
 172         fputs("\n\t  Receive Timestamp:    ", stdout);
 173         p_ntp_time(&(bp->rec_timestamp));
 174
 175         TCHECK(bp->xmt_timestamp);
 176         fputs("\n\t  Transmit Timestamp:   ", stdout);
 177         p_ntp_time(&(bp->xmt_timestamp));
 178
 179         fputs("\n\t    Originator - Receive Timestamp:  ", stdout);
 180         p_ntp_delta(&(bp->org_timestamp), &(bp->rec_timestamp));
 181
 182         fputs("\n\t    Originator - Transmit Timestamp: ", stdout);
 183         p_ntp_delta(&(bp->org_timestamp), &(bp->xmt_timestamp));
 184
 185         if ( (sizeof(struct ntpdata) - length) == 16) {         /* Optional: key-id */
 186                 TCHECK(bp->key_id);
 187                 printf("\n\tKey id: %u", bp->key_id);
 188         } else if ( (sizeof(struct ntpdata) - length) == 0) {   /* Optional: key-id + authentication */
 189                 TCHECK(bp->key_id);
 190                 printf("\n\tKey id: %u", bp->key_id);
 191                 TCHECK2(bp->message_digest, sizeof (bp->message_digest));
 192                 printf("\n\tAuthentication: %08x%08x%08x%08x",
 193                                EXTRACT_32BITS(bp->message_digest),
 194                                EXTRACT_32BITS(bp->message_digest + 4),
 195                                EXTRACT_32BITS(bp->message_digest + 8),
 196                                EXTRACT_32BITS(bp->message_digest + 12));
 197         }
 198         return;
 199
 200 trunc:
 201         fputs(" [|ntp]", stdout);
 202 }
 203
 204 static void
 205 p_sfix(register const struct s_fixedpt *sfp)
 206 {
 207         register int i;
 208         register int f;
 209         register float ff;
 210
 211         i = EXTRACT_16BITS(&sfp->int_part);
 212         f = EXTRACT_16BITS(&sfp->fraction);
 213         ff = f / 65536.0;       /* shift radix point by 16 bits */
 214         f = ff * 1000000.0;     /* Treat fraction as parts per million */
 215         printf("%d.%06d", i, f);
 216 }
 217
 218 #define FMAXINT (4294967296.0)  /* floating point rep. of MAXINT */
 219
 220 static void
 221 p_ntp_time(register const struct l_fixedpt *lfp)
 222 {
 223         register int32_t i;
 224         register u_int32_t uf;
 225         register u_int32_t f;
 226         register float ff;
 227
 228         i = EXTRACT_32BITS(&lfp->int_part);
 229         uf = EXTRACT_32BITS(&lfp->fraction);
 230         ff = uf;
 231         if (ff < 0.0)           /* some compilers are buggy */
 232                 ff += FMAXINT;
 233         ff = ff / FMAXINT;      /* shift radix point by 32 bits */
 234         f = ff * 1000000000.0;  /* treat fraction as parts per billion */
 235         printf("%u.%09d", i, f);
 236
 237 #ifdef HAVE_STRFTIME
 238         /*
 239          * print the time in human-readable format.
 240          */
 241         if (i) {
 242             time_t seconds = i - JAN_1970;
 243             struct tm *tm;
 244             char time_buf[128];
 245
 246             tm = localtime(&seconds);
 247             strftime(time_buf, sizeof (time_buf), "%Y/%m/%d %H:%M:%S", tm);
 248             printf (" (%s)", time_buf);
 249         }
 250 #endif
 251 }
 252
 253 /* Prints time difference between *lfp and *olfp */
 254 static void
 255 p_ntp_delta(register const struct l_fixedpt *olfp,
 256             register const struct l_fixedpt *lfp)
 257 {
 258         register int32_t i;
 259         register u_int32_t u, uf;
 260         register u_int32_t ou, ouf;
 261         register u_int32_t f;
 262         register float ff;
 263         int signbit;
 264
 265         u = EXTRACT_32BITS(&lfp->int_part);
 266         ou = EXTRACT_32BITS(&olfp->int_part);
 267         uf = EXTRACT_32BITS(&lfp->fraction);
 268         ouf = EXTRACT_32BITS(&olfp->fraction);
 269         if (ou == 0 && ouf == 0) {
 270                 p_ntp_time(lfp);
 271                 return;
 272         }
 273
 274         i = u - ou;
 275
 276         if (i > 0) {            /* new is definitely greater than old */
 277                 signbit = 0;
 278                 f = uf - ouf;
 279                 if (ouf > uf)   /* must borrow from high-order bits */
 280                         i -= 1;
 281         } else if (i < 0) {     /* new is definitely less than old */
 282                 signbit = 1;
 283                 f = ouf - uf;
 284                 if (uf > ouf)   /* must carry into the high-order bits */
 285                         i += 1;
 286                 i = -i;
 287         } else {                /* int_part is zero */
 288                 if (uf > ouf) {
 289                         signbit = 0;
 290                         f = uf - ouf;
 291                 } else {
 292                         signbit = 1;
 293                         f = ouf - uf;
 294                 }
 295         }
 296
 297         ff = f;
 298         if (ff < 0.0)           /* some compilers are buggy */
 299                 ff += FMAXINT;
 300         ff = ff / FMAXINT;      /* shift radix point by 32 bits */
 301         f = ff * 1000000000.0;  /* treat fraction as parts per billion */
 302         if (signbit)
 303                 putchar('-');
 304         else
 305                 putchar('+');
 306         printf("%d.%09d", i, f);
 307 }
 308