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  *      By Jeffrey Mogul/DECWRL
  22  *      loosely based on print-bootp.c
  23  */
  24
  25 /* \summary: Network Time Protocol (NTP) printer */
  26
  27 #ifdef HAVE_CONFIG_H
  28 #include "config.h"
  29 #endif
  30
  31 #include <netdissect-stdinc.h>
  32
  33 #ifdef HAVE_STRFTIME
  34 #include <time.h>
  35 #endif
  36
  37 #include "netdissect.h"
  38 #include "addrtoname.h"
  39 #include "extract.h"
  40
  41 /*
  42  * Based on ntp.h from the U of MD implementation
  43  *      This file is based on Version 2 of the NTP spec (RFC1119).
  44  */
  45
  46 /*
  47  *  Definitions for the masses
  48  */
  49 #define JAN_1970        2208988800U     /* 1970 - 1900 in seconds */
  50
  51 /*
  52  * Structure definitions for NTP fixed point values
  53  *
  54  *    0                   1                   2                   3
  55  *    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
  56  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  57  *   |                         Integer Part                          |
  58  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  59  *   |                         Fraction Part                         |
  60  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  61  *
  62  *    0                   1                   2                   3
  63  *    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
  64  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  65  *   |            Integer Part       |     Fraction Part             |
  66  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  67 */
  68 struct l_fixedpt {
  69         uint32_t int_part;
  70         uint32_t fraction;
  71 };
  72
  73 struct s_fixedpt {
  74         uint16_t int_part;
  75         uint16_t fraction;
  76 };
  77
  78 /* rfc2030
  79  *                      1                   2                   3
  80  *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
  81  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  82  * |LI | VN  |Mode |    Stratum    |     Poll      |   Precision   |
  83  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  84  * |                          Root Delay                           |
  85  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  86  * |                       Root Dispersion                         |
  87  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  88  * |                     Reference Identifier                      |
  89  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  90  * |                                                               |
  91  * |                   Reference Timestamp (64)                    |
  92  * |                                                               |
  93  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  94  * |                                                               |
  95  * |                   Originate Timestamp (64)                    |
  96  * |                                                               |
  97  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  98  * |                                                               |
  99  * |                    Receive Timestamp (64)                     |
 100  * |                                                               |
 101  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 102  * |                                                               |
 103  * |                    Transmit Timestamp (64)                    |
 104  * |                                                               |
 105  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 106  * |                 Key Identifier (optional) (32)                |
 107  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 108  * |                                                               |
 109  * |                                                               |
 110  * |                 Message Digest (optional) (128)               |
 111  * |                                                               |
 112  * |                                                               |
 113  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 114  */
 115
 116 struct ntpdata {
 117         u_char status;          /* status of local clock and leap info */
 118         u_char stratum;         /* Stratum level */
 119         int ppoll:8;            /* poll value */
 120         int precision:8;
 121         struct s_fixedpt root_delay;
 122         struct s_fixedpt root_dispersion;
 123         uint32_t refid;
 124         struct l_fixedpt ref_timestamp;
 125         struct l_fixedpt org_timestamp;
 126         struct l_fixedpt rec_timestamp;
 127         struct l_fixedpt xmt_timestamp;
 128         uint32_t key_id;
 129         uint8_t  message_digest[16];
 130 };
 131 /*
 132  *      Leap Second Codes (high order two bits)
 133  */
 134 #define NO_WARNING      0x00    /* no warning */
 135 #define PLUS_SEC        0x40    /* add a second (61 seconds) */
 136 #define MINUS_SEC       0x80    /* minus a second (59 seconds) */
 137 #define ALARM           0xc0    /* alarm condition (clock unsynchronized) */
 138
 139 /*
 140  *      Clock Status Bits that Encode Version
 141  */
 142 #define NTPVERSION_1    0x08
 143 #define VERSIONMASK     0x38
 144 #define LEAPMASK        0xc0
 145 #ifdef MODEMASK
 146 #undef MODEMASK                                 /* Solaris sucks */
 147 #endif
 148 #define MODEMASK        0x07
 149
 150 /*
 151  *      Code values
 152  */
 153 #define MODE_UNSPEC     0       /* unspecified */
 154 #define MODE_SYM_ACT    1       /* symmetric active */
 155 #define MODE_SYM_PAS    2       /* symmetric passive */
 156 #define MODE_CLIENT     3       /* client */
 157 #define MODE_SERVER     4       /* server */
 158 #define MODE_BROADCAST  5       /* broadcast */
 159 #define MODE_RES1       6       /* reserved */
 160 #define MODE_RES2       7       /* reserved */
 161
 162 /*
 163  *      Stratum Definitions
 164  */
 165 #define UNSPECIFIED     0
 166 #define PRIM_REF        1       /* radio clock */
 167 #define INFO_QUERY      62      /* **** THIS implementation dependent **** */
 168 #define INFO_REPLY      63      /* **** THIS implementation dependent **** */
 169
 170 static void p_sfix(netdissect_options *ndo, const struct s_fixedpt *);
 171 static void p_ntp_time(netdissect_options *, const struct l_fixedpt *);
 172 static void p_ntp_delta(netdissect_options *, const struct l_fixedpt *, const struct l_fixedpt *);
 173 static void p_poll(netdissect_options *, register const int);
 174
 175 static const struct tok ntp_mode_values[] = {
 176     { MODE_UNSPEC,    "unspecified" },
 177     { MODE_SYM_ACT,   "symmetric active" },
 178     { MODE_SYM_PAS,   "symmetric passive" },
 179     { MODE_CLIENT,    "Client" },
 180     { MODE_SERVER,    "Server" },
 181     { MODE_BROADCAST, "Broadcast" },
 182     { MODE_RES1,      "Reserved" },
 183     { MODE_RES2,      "Reserved" },
 184     { 0, NULL }
 185 };
 186
 187 static const struct tok ntp_leapind_values[] = {
 188     { NO_WARNING,     "" },
 189     { PLUS_SEC,       "+1s" },
 190     { MINUS_SEC,      "-1s" },
 191     { ALARM,          "clock unsynchronized" },
 192     { 0, NULL }
 193 };
 194
 195 static const struct tok ntp_stratum_values[] = {
 196         { UNSPECIFIED,  "unspecified" },
 197         { PRIM_REF,     "primary reference" },
 198         { 0, NULL }
 199 };
 200
 201 /*
 202  * Print ntp requests
 203  */
 204 void
 205 ntp_print(netdissect_options *ndo,
 206           register const u_char *cp, u_int length)
 207 {
 208         register const struct ntpdata *bp;
 209         int mode, version, leapind;
 210
 211         bp = (const struct ntpdata *)cp;
 212
 213         ND_TCHECK(bp->status);
 214
 215         version = (int)(bp->status & VERSIONMASK) >> 3;
 216         ND_PRINT((ndo, "NTPv%d", version));
 217
 218         mode = bp->status & MODEMASK;
 219         if (!ndo->ndo_vflag) {
 220                 ND_PRINT((ndo, ", %s, length %u",
 221                           tok2str(ntp_mode_values, "Unknown mode", mode),
 222                           length));
 223                 return;
 224         }
 225
 226         ND_PRINT((ndo, ", length %u\n\t%s",
 227                   length,
 228                   tok2str(ntp_mode_values, "Unknown mode", mode)));
 229
 230         leapind = bp->status & LEAPMASK;
 231         ND_PRINT((ndo, ", Leap indicator: %s (%u)",
 232                   tok2str(ntp_leapind_values, "Unknown", leapind),
 233                   leapind));
 234
 235         ND_TCHECK(bp->stratum);
 236         ND_PRINT((ndo, ", Stratum %u (%s)",
 237                 bp->stratum,
 238                 tok2str(ntp_stratum_values, (bp->stratum >=2 && bp->stratum<=15) ? "secondary reference" : "reserved", bp->stratum)));
 239
 240         /* Can't ND_TCHECK bp->ppoll bitfield so bp->stratum + 2 instead */
 241         ND_TCHECK2(bp->stratum, 2);
 242         ND_PRINT((ndo, ", poll %d", bp->ppoll));
 243         p_poll(ndo, bp->ppoll);
 244
 245         /* Can't ND_TCHECK bp->precision bitfield so bp->distance + 0 instead */
 246         ND_TCHECK2(bp->root_delay, 0);
 247         ND_PRINT((ndo, ", precision %d", bp->precision));
 248
 249         ND_TCHECK(bp->root_delay);
 250         ND_PRINT((ndo, "\n\tRoot Delay: "));
 251         p_sfix(ndo, &bp->root_delay);
 252
 253         ND_TCHECK(bp->root_dispersion);
 254         ND_PRINT((ndo, ", Root dispersion: "));
 255         p_sfix(ndo, &bp->root_dispersion);
 256
 257         ND_TCHECK(bp->refid);
 258         ND_PRINT((ndo, ", Reference-ID: "));
 259         /* Interpretation depends on stratum */
 260         switch (bp->stratum) {
 261
 262         case UNSPECIFIED:
 263                 ND_PRINT((ndo, "(unspec)"));
 264                 break;
 265
 266         case PRIM_REF:
 267                 if (fn_printn(ndo, (const u_char *)&(bp->refid), 4, ndo->ndo_snapend))
 268                         goto trunc;
 269                 break;
 270
 271         case INFO_QUERY:
 272                 ND_PRINT((ndo, "%s INFO_QUERY", ipaddr_string(ndo, &(bp->refid))));
 273                 /* this doesn't have more content */
 274                 return;
 275
 276         case INFO_REPLY:
 277                 ND_PRINT((ndo, "%s INFO_REPLY", ipaddr_string(ndo, &(bp->refid))));
 278                 /* this is too complex to be worth printing */
 279                 return;
 280
 281         default:
 282                 /* In NTPv4 (RFC 5905) refid is an IPv4 address or first 32 bits of
 283                    MD5 sum of IPv6 address */
 284                 ND_PRINT((ndo, "0x%08x", EXTRACT_32BITS(&bp->refid)));
 285                 break;
 286         }
 287
 288         ND_TCHECK(bp->ref_timestamp);
 289         ND_PRINT((ndo, "\n\t  Reference Timestamp:  "));
 290         p_ntp_time(ndo, &(bp->ref_timestamp));
 291
 292         ND_TCHECK(bp->org_timestamp);
 293         ND_PRINT((ndo, "\n\t  Originator Timestamp: "));
 294         p_ntp_time(ndo, &(bp->org_timestamp));
 295
 296         ND_TCHECK(bp->rec_timestamp);
 297         ND_PRINT((ndo, "\n\t  Receive Timestamp:    "));
 298         p_ntp_time(ndo, &(bp->rec_timestamp));
 299
 300         ND_TCHECK(bp->xmt_timestamp);
 301         ND_PRINT((ndo, "\n\t  Transmit Timestamp:   "));
 302         p_ntp_time(ndo, &(bp->xmt_timestamp));
 303
 304         ND_PRINT((ndo, "\n\t    Originator - Receive Timestamp:  "));
 305         p_ntp_delta(ndo, &(bp->org_timestamp), &(bp->rec_timestamp));
 306
 307         ND_PRINT((ndo, "\n\t    Originator - Transmit Timestamp: "));
 308         p_ntp_delta(ndo, &(bp->org_timestamp), &(bp->xmt_timestamp));
 309
 310         if ( (sizeof(struct ntpdata) - length) == 16) {         /* Optional: key-id */
 311                 ND_TCHECK(bp->key_id);
 312                 ND_PRINT((ndo, "\n\tKey id: %u", EXTRACT_32BITS(&bp->key_id)));
 313         } else if ( (sizeof(struct ntpdata) - length) == 0) {   /* Optional: key-id + authentication */
 314                 ND_TCHECK(bp->key_id);
 315                 ND_PRINT((ndo, "\n\tKey id: %u", EXTRACT_32BITS(&bp->key_id)));
 316                 ND_TCHECK2(bp->message_digest, sizeof (bp->message_digest));
 317                 ND_PRINT((ndo, "\n\tAuthentication: %08x%08x%08x%08x",
 318                                EXTRACT_32BITS(bp->message_digest),
 319                                EXTRACT_32BITS(bp->message_digest + 4),
 320                                EXTRACT_32BITS(bp->message_digest + 8),
 321                                EXTRACT_32BITS(bp->message_digest + 12)));
 322         }
 323         return;
 324
 325 trunc:
 326         ND_PRINT((ndo, " [|ntp]"));
 327 }
 328
 329 static void
 330 p_sfix(netdissect_options *ndo,
 331        register const struct s_fixedpt *sfp)
 332 {
 333         register int i;
 334         register int f;
 335         register double ff;
 336
 337         i = EXTRACT_16BITS(&sfp->int_part);
 338         f = EXTRACT_16BITS(&sfp->fraction);
 339         ff = f / 65536.0;               /* shift radix point by 16 bits */
 340         f = (int)(ff * 1000000.0);      /* Treat fraction as parts per million */
 341         ND_PRINT((ndo, "%d.%06d", i, f));
 342 }
 343
 344 #define FMAXINT (4294967296.0)  /* floating point rep. of MAXINT */
 345
 346 static void
 347 p_ntp_time(netdissect_options *ndo,
 348            register const struct l_fixedpt *lfp)
 349 {
 350         register int32_t i;
 351         register uint32_t uf;
 352         register uint32_t f;
 353         register double ff;
 354
 355         i = EXTRACT_32BITS(&lfp->int_part);
 356         uf = EXTRACT_32BITS(&lfp->fraction);
 357         ff = uf;
 358         if (ff < 0.0)           /* some compilers are buggy */
 359                 ff += FMAXINT;
 360         ff = ff / FMAXINT;                      /* shift radix point by 32 bits */
 361         f = (uint32_t)(ff * 1000000000.0);      /* treat fraction as parts per billion */
 362         ND_PRINT((ndo, "%u.%09d", i, f));
 363
 364 #ifdef HAVE_STRFTIME
 365         /*
 366          * print the time in human-readable format.
 367          */
 368         if (i) {
 369             time_t seconds = i - JAN_1970;
 370             struct tm *tm;
 371             char time_buf[128];
 372
 373             tm = localtime(&seconds);
 374             strftime(time_buf, sizeof (time_buf), "%Y/%m/%d %H:%M:%S", tm);
 375             ND_PRINT((ndo, " (%s)", time_buf));
 376         }
 377 #endif
 378 }
 379
 380 /* Prints time difference between *lfp and *olfp */
 381 static void
 382 p_ntp_delta(netdissect_options *ndo,
 383             register const struct l_fixedpt *olfp,
 384             register const struct l_fixedpt *lfp)
 385 {
 386         register int32_t i;
 387         register uint32_t u, uf;
 388         register uint32_t ou, ouf;
 389         register uint32_t f;
 390         register double ff;
 391         int signbit;
 392
 393         u = EXTRACT_32BITS(&lfp->int_part);
 394         ou = EXTRACT_32BITS(&olfp->int_part);
 395         uf = EXTRACT_32BITS(&lfp->fraction);
 396         ouf = EXTRACT_32BITS(&olfp->fraction);
 397         if (ou == 0 && ouf == 0) {
 398                 p_ntp_time(ndo, lfp);
 399                 return;
 400         }
 401
 402         i = u - ou;
 403
 404         if (i > 0) {            /* new is definitely greater than old */
 405                 signbit = 0;
 406                 f = uf - ouf;
 407                 if (ouf > uf)   /* must borrow from high-order bits */
 408                         i -= 1;
 409         } else if (i < 0) {     /* new is definitely less than old */
 410                 signbit = 1;
 411                 f = ouf - uf;
 412                 if (uf > ouf)   /* must carry into the high-order bits */
 413                         i += 1;
 414                 i = -i;
 415         } else {                /* int_part is zero */
 416                 if (uf > ouf) {
 417                         signbit = 0;
 418                         f = uf - ouf;
 419                 } else {
 420                         signbit = 1;
 421                         f = ouf - uf;
 422                 }
 423         }
 424
 425         ff = f;
 426         if (ff < 0.0)           /* some compilers are buggy */
 427                 ff += FMAXINT;
 428         ff = ff / FMAXINT;                      /* shift radix point by 32 bits */
 429         f = (uint32_t)(ff * 1000000000.0);      /* treat fraction as parts per billion */
 430         ND_PRINT((ndo, "%s%d.%09d", signbit ? "-" : "+", i, f));
 431 }
 432
 433 /* Prints polling interval in log2 as seconds or fraction of second */
 434 static void
 435 p_poll(netdissect_options *ndo,
 436        register const int poll)
 437 {
 438         if (poll <= -32 || poll >= 32)
 439                 return;
 440
 441         if (poll >= 0)
 442                 ND_PRINT((ndo, " (%us)", 1U << poll));
 443         else
 444                 ND_PRINT((ndo, " (1/%us)", 1U << -poll));
 445 }
 446