shadow/libmisc/gettime.c

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/*
* Copyright (c) 2017, Chris Lamb
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the copyright holders or contributors may not be used to
* endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
* PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <config.h>
#ident "$Id$"
#include <errno.h>
#include <limits.h>
#include <stdio.h>
#include "defines.h"
#include "prototypes.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;
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;
}