Files
shadow/lib/gettime.c
Alejandro Colomar 1c464d9a2d lib/, src/: Fix error handling after strto[u]l[l](3)
-  Set errno = 0 before the call.  Otherwise, it may contain anything.
-  ERANGE is not the only possible errno value of these functions.  They
   can also set it to EINVAL.
-  Any errno value after these calls is bad; just compare against 0.
-  Don't check for the return value; just errno.  This function is
   guaranteed to not modify errno on success (POSIX).
-  Check endptr == str, which may or may not set EINVAL.

Suggested-by: Iker Pedrosa <ipedrosa@redhat.com>
Signed-off-by: Alejandro Colomar <alx@kernel.org>
2023-12-04 12:21:55 +01:00

68 lines
1.8 KiB
C

/*
* 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 (void)
{
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 != 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 ((time_t)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 epoch;
}
return fallback;
}