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/*
* Copyright (c) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that: (1) source code distributions
* retain the above copyright notice and this paragraph in its entirety, (2)
* distributions including binary code include the above copyright notice and
* this paragraph in its entirety in the documentation or other materials
* provided with the distribution, and (3) all advertising materials mentioning
* features or use of this software display the following acknowledgement:
* ``This product includes software developed by the University of California,
* Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
* the University nor the names of its contributors may be used to endorse
* or promote products derived from this software without specific prior
* written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*
*/
#include <config.h>
#include "ntp.h"
#include "extract.h"
/* NTP epoch 1: January 1, 1900, 00:00:00 UTC. */
#define DIFF_1970_1900 INT64_C(2208988800) /* 1970 - 1900 in seconds */
/* RFC4330 - 3. NTP Timestamp Format - 6h 28m 16s UTC on 7 February 2036 */
/* NTP epoch 2: February 7, 2036, 06:28:16 UTC. */
#define DIFF_2036_1970 INT64_C(2085978496) /* 2036 - 1970 in seconds */
void
p_ntp_time_fmt(netdissect_options *ndo, const char *fmt,
const struct l_fixedpt *lfp)
{
uint32_t i;
uint32_t uf;
uint32_t f;
double ff;
i = GET_BE_U_4(lfp->int_part);
uf = GET_BE_U_4(lfp->fraction);
ff = uf;
if (ff < 0.0) /* some compilers are buggy */
ff += FMAXINT;
ff = ff / FMAXINT; /* shift radix point by 32 bits */
f = (uint32_t)(ff * 1000000000.0); /* treat fraction as parts per billion */
ND_PRINT("%u.%09u", i, f);
/*
* print the UTC time in human-readable format.
*/
if (i) {
int64_t seconds_64bit;
time_t seconds;
char time_buf[128];
const char *time_string;
if ((i & 0x80000000) != 0)
seconds_64bit = (int64_t)i - DIFF_1970_1900;
else
seconds_64bit = (int64_t)i + DIFF_2036_1970;
seconds = (time_t)seconds_64bit;
if (seconds != seconds_64bit) {
/*
* It doesn't fit into a time_t, so we can't hand it
* to gmtime.
*/
time_string = "[timestamp overflow]";
} else {
time_string = nd_format_time(time_buf, sizeof (time_buf),
fmt, gmtime(&seconds));
}
ND_PRINT(" (%s)", time_string);
}
}
void
p_ntp_time(netdissect_options *ndo, const struct l_fixedpt *lfp)
{
/* use ISO 8601 (RFC3339) format */
p_ntp_time_fmt(ndo, "%Y-%m-%dT%H:%M:%SZ", lfp);
}
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