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