external/bsd/tcpdump/dist/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 #include <sys/cdefs.h>
  27 #ifndef lint
  28 __RCSID("$NetBSD: print-ntp.c,v 1.5 2014/11/20 03:05:03 christos Exp $");
  29 #endif
  30
  31 #define NETDISSECT_REWORKED
  32 #ifdef HAVE_CONFIG_H
  33 #include "config.h"
  34 #endif
  35
  36 #include <tcpdump-stdinc.h>
  37
  38 #ifdef HAVE_STRFTIME
  39 #include <time.h>
  40 #endif
  41
  42 #include "interface.h"
  43 #include "addrtoname.h"
  44 #include "extract.h"
  45
  46 /*
  47  * Based on ntp.h from the U of MD implementation
  48  *      This file is based on Version 2 of the NTP spec (RFC1119).
  49  */
  50
  51 /*
  52  *  Definitions for the masses
  53  */
  54 #define JAN_1970        2208988800U     /* 1970 - 1900 in seconds */
  55
  56 /*
  57  * Structure definitions for NTP fixed point values
  58  *
  59  *    0                   1                   2                   3
  60  *    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
  61  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  62  *   |                         Integer Part                          |
  63  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  64  *   |                         Fraction Part                         |
  65  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  66  *
  67  *    0                   1                   2                   3
  68  *    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
  69  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  70  *   |            Integer Part       |     Fraction Part             |
  71  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  72 */
  73 struct l_fixedpt {
  74         uint32_t int_part;
  75         uint32_t fraction;
  76 };
  77
  78 struct s_fixedpt {
  79         uint16_t int_part;
  80         uint16_t fraction;
  81 };
  82
  83 /* rfc2030
  84  *                      1                   2                   3
  85  *  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
  86  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  87  * |LI | VN  |Mode |    Stratum    |     Poll      |   Precision   |
  88  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  89  * |                          Root Delay                           |
  90  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  91  * |                       Root Dispersion                         |
  92  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  93  * |                     Reference Identifier                      |
  94  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  95  * |                                                               |
  96  * |                   Reference Timestamp (64)                    |
  97  * |                                                               |
  98  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  99  * |                                                               |
 100  * |                   Originate Timestamp (64)                    |
 101  * |                                                               |
 102  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 103  * |                                                               |
 104  * |                    Receive Timestamp (64)                     |
 105  * |                                                               |
 106  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 107  * |                                                               |
 108  * |                    Transmit Timestamp (64)                    |
 109  * |                                                               |
 110  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 111  * |                 Key Identifier (optional) (32)                |
 112  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 113  * |                                                               |
 114  * |                                                               |
 115  * |                 Message Digest (optional) (128)               |
 116  * |                                                               |
 117  * |                                                               |
 118  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 119  */
 120
 121 struct ntpdata {
 122         u_char status;          /* status of local clock and leap info */
 123         u_char stratum;         /* Stratum level */
 124         u_char ppoll;           /* poll value */
 125         int precision:8;
 126         struct s_fixedpt root_delay;
 127         struct s_fixedpt root_dispersion;
 128         uint32_t refid;
 129         struct l_fixedpt ref_timestamp;
 130         struct l_fixedpt org_timestamp;
 131         struct l_fixedpt rec_timestamp;
 132         struct l_fixedpt xmt_timestamp;
 133         uint32_t key_id;
 134         uint8_t  message_digest[16];
 135 };
 136 /*
 137  *      Leap Second Codes (high order two bits)
 138  */
 139 #define NO_WARNING      0x00    /* no warning */
 140 #define PLUS_SEC        0x40    /* add a second (61 seconds) */
 141 #define MINUS_SEC       0x80    /* minus a second (59 seconds) */
 142 #define ALARM           0xc0    /* alarm condition (clock unsynchronized) */
 143
 144 /*
 145  *      Clock Status Bits that Encode Version
 146  */
 147 #define NTPVERSION_1    0x08
 148 #define VERSIONMASK     0x38
 149 #define LEAPMASK        0xc0
 150 #ifdef MODEMASK
 151 #undef MODEMASK                                 /* Solaris sucks */
 152 #endif
 153 #define MODEMASK        0x07
 154
 155 /*
 156  *      Code values
 157  */
 158 #define MODE_UNSPEC     0       /* unspecified */
 159 #define MODE_SYM_ACT    1       /* symmetric active */
 160 #define MODE_SYM_PAS    2       /* symmetric passive */
 161 #define MODE_CLIENT     3       /* client */
 162 #define MODE_SERVER     4       /* server */
 163 #define MODE_BROADCAST  5       /* broadcast */
 164 #define MODE_RES1       6       /* reserved */
 165 #define MODE_RES2       7       /* reserved */
 166
 167 /*
 168  *      Stratum Definitions
 169  */
 170 #define UNSPECIFIED     0
 171 #define PRIM_REF        1       /* radio clock */
 172 #define INFO_QUERY      62      /* **** THIS implementation dependent **** */
 173 #define INFO_REPLY      63      /* **** THIS implementation dependent **** */
 174
 175 static void p_sfix(netdissect_options *ndo, const struct s_fixedpt *);
 176 static void p_ntp_time(netdissect_options *, const struct l_fixedpt *);
 177 static void p_ntp_delta(netdissect_options *, const struct l_fixedpt *, const struct l_fixedpt *);
 178
 179 static const struct tok ntp_mode_values[] = {
 180     { MODE_UNSPEC,    "unspecified" },
 181     { MODE_SYM_ACT,   "symmetric active" },
 182     { MODE_SYM_PAS,   "symmetric passive" },
 183     { MODE_CLIENT,    "Client" },
 184     { MODE_SERVER,    "Server" },
 185     { MODE_BROADCAST, "Broadcast" },
 186     { MODE_RES1,      "Reserved" },
 187     { MODE_RES2,      "Reserved" },
 188     { 0, NULL }
 189 };
 190
 191 static const struct tok ntp_leapind_values[] = {
 192     { NO_WARNING,     "" },
 193     { PLUS_SEC,       "+1s" },
 194     { MINUS_SEC,      "-1s" },
 195     { ALARM,          "clock unsynchronized" },
 196     { 0, NULL }
 197 };
 198
 199 static const struct tok ntp_stratum_values[] = {
 200         { UNSPECIFIED,  "unspecified" },
 201         { PRIM_REF,     "primary reference" },
 202         { 0, NULL }
 203 };
 204
 205 /*
 206  * Print ntp requests
 207  */
 208 void
 209 ntp_print(netdissect_options *ndo,
 210           register const u_char *cp, u_int length)
 211 {
 212         register const struct ntpdata *bp;
 213         int mode, version, leapind;
 214
 215         bp = (struct ntpdata *)cp;
 216
 217         ND_TCHECK(bp->status);
 218
 219         version = (int)(bp->status & VERSIONMASK) >> 3;
 220         ND_PRINT((ndo, "NTPv%d", version));
 221
 222         mode = bp->status & MODEMASK;
 223         if (!ndo->ndo_vflag) {
 224                 ND_PRINT((ndo, ", %s, length %u",
 225                           tok2str(ntp_mode_values, "Unknown mode", mode),
 226                           length));
 227                 return;
 228         }
 229
 230         ND_PRINT((ndo, ", length %u\n\t%s",
 231                   length,
 232                   tok2str(ntp_mode_values, "Unknown mode", mode)));
 233
 234         leapind = bp->status & LEAPMASK;
 235         ND_PRINT((ndo, ", Leap indicator: %s (%u)",
 236                   tok2str(ntp_leapind_values, "Unknown", leapind),
 237                   leapind));
 238
 239         ND_TCHECK(bp->stratum);
 240         ND_PRINT((ndo, ", Stratum %u (%s)",
 241                 bp->stratum,
 242                 tok2str(ntp_stratum_values, (bp->stratum >=2 && bp->stratum<=15) ? "secondary reference" : "reserved", bp->stratum)));
 243
 244         ND_TCHECK(bp->ppoll);
 245         ND_PRINT((ndo, ", poll %u (%us)", bp->ppoll, 1 << bp->ppoll));
 246
 247         /* Can't ND_TCHECK bp->precision bitfield so bp->distance + 0 instead */
 248         ND_TCHECK2(bp->root_delay, 0);
 249         ND_PRINT((ndo, ", precision %d", bp->precision));
 250
 251         ND_TCHECK(bp->root_delay);
 252         ND_PRINT((ndo, "\n\tRoot Delay: "));
 253         p_sfix(ndo, &bp->root_delay);
 254
 255         ND_TCHECK(bp->root_dispersion);
 256         ND_PRINT((ndo, ", Root dispersion: "));
 257         p_sfix(ndo, &bp->root_dispersion);
 258
 259         ND_TCHECK(bp->refid);
 260         ND_PRINT((ndo, ", Reference-ID: "));
 261         /* Interpretation depends on stratum */
 262         switch (bp->stratum) {
 263
 264         case UNSPECIFIED:
 265                 ND_PRINT((ndo, "(unspec)"));
 266                 break;
 267
 268         case PRIM_REF:
 269                 if (fn_printn(ndo, (u_char *)&(bp->refid), 4, ndo->ndo_snapend))
 270                         goto trunc;
 271                 break;
 272
 273         case INFO_QUERY:
 274                 ND_PRINT((ndo, "%s INFO_QUERY", ipaddr_string(ndo, &(bp->refid))));
 275                 /* this doesn't have more content */
 276                 return;
 277
 278         case INFO_REPLY:
 279                 ND_PRINT((ndo, "%s INFO_REPLY", ipaddr_string(ndo, &(bp->refid))));
 280                 /* this is too complex to be worth printing */
 281                 return;
 282
 283         default:
 284                 ND_PRINT((ndo, "%s", ipaddr_string(ndo, &(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", 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", 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 float 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 = 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 float 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 = 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 float 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 = ff * 1000000000.0;  /* treat fraction as parts per billion */
 430         ND_PRINT((ndo, "%s%d.%09d", signbit ? "-" : "+", i, f));
 431 }
 432