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21 * Format and print ntp packets.
22 * By Jeffrey Mogul/DECWRL
23 * loosely based on print-bootp.c
28 #define NETDISSECT_REWORKED
33 #include <tcpdump-stdinc.h>
39 #include "interface.h"
40 #include "addrtoname.h"
44 * Based on ntp.h from the U of MD implementation
45 * This file is based on Version 2 of the NTP spec (RFC1119).
49 * Definitions for the masses
51 #define JAN_1970 2208988800U /* 1970 - 1900 in seconds */
54 * Structure definitions for NTP fixed point values
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 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
60 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
62 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
87 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
89 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
90 * | Reference Identifier |
91 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
93 * | Reference Timestamp (64) |
95 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
97 * | Originate Timestamp (64) |
99 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
101 * | Receive Timestamp (64) |
103 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
105 * | Transmit Timestamp (64) |
107 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
108 * | Key Identifier (optional) (32) |
109 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
112 * | Message Digest (optional) (128) |
115 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
119 u_char status; /* status of local clock and leap info */
120 u_char stratum; /* Stratum level */
121 u_char ppoll; /* poll value */
123 struct s_fixedpt root_delay;
124 struct s_fixedpt root_dispersion;
126 struct l_fixedpt ref_timestamp;
127 struct l_fixedpt org_timestamp;
128 struct l_fixedpt rec_timestamp;
129 struct l_fixedpt xmt_timestamp;
131 uint8_t message_digest[16];
134 * Leap Second Codes (high order two bits)
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) */
142 * Clock Status Bits that Encode Version
144 #define NTPVERSION_1 0x08
145 #define VERSIONMASK 0x38
146 #define LEAPMASK 0xc0
148 #undef MODEMASK /* Solaris sucks */
150 #define MODEMASK 0x07
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 */
165 * Stratum Definitions
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 **** */
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 *);
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" },
188 static const struct tok ntp_leapind_values[] = {
191 { MINUS_SEC, "-1s" },
192 { ALARM, "clock unsynchronized" },
196 static const struct tok ntp_stratum_values[] = {
197 { UNSPECIFIED, "unspecified" },
198 { PRIM_REF, "primary reference" },
206 ntp_print(netdissect_options *ndo,
207 register const u_char *cp, u_int length)
209 register const struct ntpdata *bp;
210 int mode, version, leapind;
212 bp = (struct ntpdata *)cp;
214 ND_TCHECK(bp->status);
216 version = (int)(bp->status & VERSIONMASK) >> 3;
217 ND_PRINT((ndo, "NTPv%d", version));
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),
227 ND_PRINT((ndo, ", length %u\n\t%s",
229 tok2str(ntp_mode_values, "Unknown mode", mode)));
231 leapind = bp->status & LEAPMASK;
232 ND_PRINT((ndo, ", Leap indicator: %s (%u)",
233 tok2str(ntp_leapind_values, "Unknown", leapind),
236 ND_TCHECK(bp->stratum);
237 ND_PRINT((ndo, ", Stratum %u (%s)",
239 tok2str(ntp_stratum_values, (bp->stratum >=2 && bp->stratum<=15) ? "secondary reference" : "reserved", bp->stratum)));
241 ND_TCHECK(bp->ppoll);
242 ND_PRINT((ndo, ", poll %u (%us)", bp->ppoll, 1 << bp->ppoll));
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));
248 ND_TCHECK(bp->root_delay);
249 ND_PRINT((ndo, "\n\tRoot Delay: "));
250 p_sfix(ndo, &bp->root_delay);
252 ND_TCHECK(bp->root_dispersion);
253 ND_PRINT((ndo, ", Root dispersion: "));
254 p_sfix(ndo, &bp->root_dispersion);
256 ND_TCHECK(bp->refid);
257 ND_PRINT((ndo, ", Reference-ID: "));
258 /* Interpretation depends on stratum */
259 switch (bp->stratum) {
262 ND_PRINT((ndo, "(unspec)"));
266 if (fn_printn(ndo, (u_char *)&(bp->refid), 4, ndo->ndo_snapend))
271 ND_PRINT((ndo, "%s INFO_QUERY", ipaddr_string(ndo, &(bp->refid))));
272 /* this doesn't have more content */
276 ND_PRINT((ndo, "%s INFO_REPLY", ipaddr_string(ndo, &(bp->refid))));
277 /* this is too complex to be worth printing */
281 ND_PRINT((ndo, "%s", ipaddr_string(ndo, &(bp->refid))));
285 ND_TCHECK(bp->ref_timestamp);
286 ND_PRINT((ndo, "\n\t Reference Timestamp: "));
287 p_ntp_time(ndo, &(bp->ref_timestamp));
289 ND_TCHECK(bp->org_timestamp);
290 ND_PRINT((ndo, "\n\t Originator Timestamp: "));
291 p_ntp_time(ndo, &(bp->org_timestamp));
293 ND_TCHECK(bp->rec_timestamp);
294 ND_PRINT((ndo, "\n\t Receive Timestamp: "));
295 p_ntp_time(ndo, &(bp->rec_timestamp));
297 ND_TCHECK(bp->xmt_timestamp);
298 ND_PRINT((ndo, "\n\t Transmit Timestamp: "));
299 p_ntp_time(ndo, &(bp->xmt_timestamp));
301 ND_PRINT((ndo, "\n\t Originator - Receive Timestamp: "));
302 p_ntp_delta(ndo, &(bp->org_timestamp), &(bp->rec_timestamp));
304 ND_PRINT((ndo, "\n\t Originator - Transmit Timestamp: "));
305 p_ntp_delta(ndo, &(bp->org_timestamp), &(bp->xmt_timestamp));
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)));
323 ND_PRINT((ndo, " [|ntp]"));
327 p_sfix(netdissect_options *ndo,
328 register const struct s_fixedpt *sfp)
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));
341 #define FMAXINT (4294967296.0) /* floating point rep. of MAXINT */
344 p_ntp_time(netdissect_options *ndo,
345 register const struct l_fixedpt *lfp)
348 register uint32_t uf;
352 i = EXTRACT_32BITS(&lfp->int_part);
353 uf = EXTRACT_32BITS(&lfp->fraction);
355 if (ff < 0.0) /* some compilers are buggy */
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));
363 * print the time in human-readable format.
366 time_t seconds = i - JAN_1970;
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));
377 /* Prints time difference between *lfp and *olfp */
379 p_ntp_delta(netdissect_options *ndo,
380 register const struct l_fixedpt *olfp,
381 register const struct l_fixedpt *lfp)
384 register uint32_t u, uf;
385 register uint32_t ou, ouf;
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);
401 if (i > 0) { /* new is definitely greater than old */
404 if (ouf > uf) /* must borrow from high-order bits */
406 } else if (i < 0) { /* new is definitely less than old */
409 if (uf > ouf) /* must carry into the high-order bits */
412 } else { /* int_part is zero */
423 if (ff < 0.0) /* some compilers are buggy */
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));