shadow/libmisc/gettime.c

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/*
* SPDX-FileCopyrightText: 2017, Chris Lamb
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <config.h>
#ident "$Id$"
#include <errno.h>
#include <limits.h>
#include <stdio.h>
#include "defines.h"
#include "prototypes.h"
#include "shadowlog.h"
/*
* gettime() returns the time as the number of seconds since the Epoch
*
* Like time(), gettime() returns the time as the number of seconds since the
* Epoch, 1970-01-01 00:00:00 +0000 (UTC), except that if the SOURCE_DATE_EPOCH
* environment variable is exported it will use that instead.
*/
/*@observer@*/time_t gettime ()
{
char *endptr;
char *source_date_epoch;
time_t fallback;
unsigned long long epoch;
FILE *shadow_logfd = log_get_logfd();
fallback = time (NULL);
source_date_epoch = shadow_getenv ("SOURCE_DATE_EPOCH");
if (!source_date_epoch)
return fallback;
errno = 0;
epoch = strtoull (source_date_epoch, &endptr, 10);
if ((errno == ERANGE && (epoch == ULLONG_MAX || epoch == 0))
|| (errno != 0 && epoch == 0)) {
fprintf (shadow_logfd,
_("Environment variable $SOURCE_DATE_EPOCH: strtoull: %s\n"),
strerror(errno));
} else if (endptr == source_date_epoch) {
fprintf (shadow_logfd,
_("Environment variable $SOURCE_DATE_EPOCH: No digits were found: %s\n"),
endptr);
} else if (*endptr != '\0') {
fprintf (shadow_logfd,
_("Environment variable $SOURCE_DATE_EPOCH: Trailing garbage: %s\n"),
endptr);
} else if (epoch > ULONG_MAX) {
fprintf (shadow_logfd,
_("Environment variable $SOURCE_DATE_EPOCH: value must be smaller than or equal to %lu but was found to be: %llu\n"),
ULONG_MAX, epoch);
} else if (epoch > fallback) {
fprintf (shadow_logfd,
_("Environment variable $SOURCE_DATE_EPOCH: value must be smaller than or equal to the current time (%lu) but was found to be: %llu\n"),
fallback, epoch);
} else {
/* Valid */
return (time_t)epoch;
}
return fallback;
}