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 } 432 433