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 1.41 2004-01-28 14:54:50 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 /*
  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                 fn_printn((u_char *)&(bp->refid), 4, NULL);
 137                 break;
 138
 139         case INFO_QUERY:
 140                 printf("%s INFO_QUERY", ipaddr_string(&(bp->refid)));
 141                 /* this doesn't have more content */
 142                 return;
 143
 144         case INFO_REPLY:
 145                 printf("%s INFO_REPLY", ipaddr_string(&(bp->refid)));
 146                 /* this is too complex to be worth printing */
 147                 return;
 148
 149         default:
 150                 printf("%s", ipaddr_string(&(bp->refid)));
 151                 break;
 152         }
 153
 154         TCHECK(bp->ref_timestamp);
 155         fputs("\n\t  Reference Timestamp:  ", stdout);
 156         p_ntp_time(&(bp->ref_timestamp));
 157
 158         TCHECK(bp->org_timestamp);
 159         fputs("\n\t  Originator Timestamp: ", stdout);
 160         p_ntp_time(&(bp->org_timestamp));
 161
 162         TCHECK(bp->rec_timestamp);
 163         fputs("\n\t  Receive Timestamp:    ", stdout);
 164         p_ntp_time(&(bp->rec_timestamp));
 165
 166         TCHECK(bp->xmt_timestamp);
 167         fputs("\n\t  Transmit Timestamp:   ", stdout);
 168         p_ntp_time(&(bp->xmt_timestamp));
 169
 170         fputs("\n\t    Originator - Receive Timestamp:  ", stdout);
 171         p_ntp_delta(&(bp->org_timestamp), &(bp->rec_timestamp));
 172
 173         fputs("\n\t    Originator - Transmit Timestamp: ", stdout);
 174         p_ntp_delta(&(bp->org_timestamp), &(bp->xmt_timestamp));
 175
 176         /* FIXME key-id, authentication */
 177
 178         return;
 179
 180 trunc:
 181         fputs(" [|ntp]", stdout);
 182 }
 183
 184 static void
 185 p_sfix(register const struct s_fixedpt *sfp)
 186 {
 187         register int i;
 188         register int f;
 189         register float ff;
 190
 191         i = EXTRACT_16BITS(&sfp->int_part);
 192         f = EXTRACT_16BITS(&sfp->fraction);
 193         ff = f / 65536.0;       /* shift radix point by 16 bits */
 194         f = ff * 1000000.0;     /* Treat fraction as parts per million */
 195         printf("%d.%06d", i, f);
 196 }
 197
 198 #define FMAXINT (4294967296.0)  /* floating point rep. of MAXINT */
 199
 200 static void
 201 p_ntp_time(register const struct l_fixedpt *lfp)
 202 {
 203         register int32_t i;
 204         register u_int32_t uf;
 205         register u_int32_t f;
 206         register float ff;
 207
 208         i = EXTRACT_32BITS(&lfp->int_part);
 209         uf = EXTRACT_32BITS(&lfp->fraction);
 210         ff = uf;
 211         if (ff < 0.0)           /* some compilers are buggy */
 212                 ff += FMAXINT;
 213         ff = ff / FMAXINT;      /* shift radix point by 32 bits */
 214         f = ff * 1000000000.0;  /* treat fraction as parts per billion */
 215         printf("%u.%09d", i, f);
 216
 217 #ifdef HAVE_STRFTIME
 218         /*
 219          * print the time in human-readable format.
 220          */
 221         if (i) {
 222             time_t seconds = i - JAN_1970;
 223             struct tm *tm;
 224             char time_buf[128];
 225
 226             tm = localtime(&seconds);
 227             strftime(time_buf, sizeof (time_buf), "%Y/%m/%d %H:%M:%S", tm);
 228             printf (" (%s)", time_buf);
 229         }
 230 #endif
 231 }
 232
 233 /* Prints time difference between *lfp and *olfp */
 234 static void
 235 p_ntp_delta(register const struct l_fixedpt *olfp,
 236             register const struct l_fixedpt *lfp)
 237 {
 238         register int32_t i;
 239         register u_int32_t u, uf;
 240         register u_int32_t ou, ouf;
 241         register u_int32_t f;
 242         register float ff;
 243         int signbit;
 244
 245         u = EXTRACT_32BITS(&lfp->int_part);
 246         ou = EXTRACT_32BITS(&olfp->int_part);
 247         uf = EXTRACT_32BITS(&lfp->fraction);
 248         ouf = EXTRACT_32BITS(&olfp->fraction);
 249         if (ou == 0 && ouf == 0) {
 250                 p_ntp_time(lfp);
 251                 return;
 252         }
 253
 254         i = u - ou;
 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 }
 288