/* SPDX-License-Identifier: BSD-2-Clause */
/**
* @file
*
* @ingroup libcsupport
*
* @brief Set file access and modification times in nanoseconds.
*/
/*
* COPYRIGHT (C) 2021 On-Line Applications Research Corporation (OAR).
*
* 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.
*
* 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 OWNER 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.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <rtems/libio_.h>
#include <rtems/score/todimpl.h>
#include <fcntl.h>
#include <string.h>
/*
* Make sure that tv_nsec is either UTIME_NOW, UTIME_OMIT, a value
* greater than zero, or a value less-than a billion.
*
* These guidelines come from the description of the EINVAL errors on
* https://pubs.opengroup.org/onlinepubs/9699919799/functions/futimens.html
*/
bool rtems_filesystem_utime_tv_nsec_valid(struct timespec time)
{
if ( time.tv_nsec == UTIME_NOW ) {
return true;
}
if ( time.tv_nsec == UTIME_OMIT ) {
return true;
}
if ( time.tv_nsec < 0 ) {
return false;
}
if ( time.tv_nsec >= TOD_NANOSECONDS_PER_SECOND ) {
return false;
}
return true;
}
/* Determine whether the access and modified timestamps can be updated */
int rtems_filesystem_utime_check_permissions(
const rtems_filesystem_location_info_t * currentloc,
const struct timespec times[2]
)
{
struct stat st = {};
int rv;
bool write_access;
rv = (*currentloc->handlers->fstat_h)( currentloc, &st );
if ( rv != 0 ) {
rtems_set_errno_and_return_minus_one( ENOENT );
}
write_access = rtems_filesystem_check_access(
RTEMS_FS_PERMS_WRITE,
st.st_mode,
st.st_uid,
st.st_gid
);
/*
* The logic for the EACCES error is an inverted subset of the EPERM
* conditional according to the POSIX standard.
*/
if ( (times == NULL) ||
( (times[0].tv_nsec == UTIME_NOW) && (times[1].tv_nsec == UTIME_NOW) )) {
if ( !write_access ) {
rtems_set_errno_and_return_minus_one( EACCES );
}
} else {
if ( times[0].tv_nsec != UTIME_OMIT || times[1].tv_nsec != UTIME_OMIT ) {
if ( !write_access ) {
rtems_set_errno_and_return_minus_one( EPERM );
}
}
}
return 0;
}
/*
* Determine if the current time needs to be gotten, and then check
* whether the values in times are valid.
*/
int rtems_filesystem_utime_update(
const struct timespec times[2],
struct timespec new_times[2]
)
{
bool got_time = false;
struct timespec now;
/*
* If times is NULL, it's equivalent to adding UTIME_NOW in both time
* elements
*/
if ( times == NULL ) {
_Timespec_Set( &new_times[0], 0, UTIME_NOW );
_Timespec_Set( &new_times[1], 0, UTIME_NOW );
} else {
new_times[0] = times[0];
new_times[1] = times[1];
}
if ( new_times[0].tv_nsec == UTIME_NOW ) {
clock_gettime( CLOCK_REALTIME, &now );
new_times[0] = now;
got_time = true;
}
if ( new_times[1].tv_nsec == UTIME_NOW ) {
if ( !got_time ) {
clock_gettime( CLOCK_REALTIME, &now );
}
new_times[1] = now;
}
if ( !_Timespec_Is_non_negative( &new_times[0] ) ) {
rtems_set_errno_and_return_minus_one( EINVAL );
}
if ( !_Timespec_Is_non_negative( &new_times[1] ) ) {
rtems_set_errno_and_return_minus_one( EINVAL );
}
if ( !rtems_filesystem_utime_tv_nsec_valid( new_times[0] ) ) {
rtems_set_errno_and_return_minus_one( EINVAL );
}
if ( !rtems_filesystem_utime_tv_nsec_valid( new_times[1] ) ) {
rtems_set_errno_and_return_minus_one( EINVAL );
}
return 0;
}
/**
* https://pubs.opengroup.org/onlinepubs/9699919799.2008edition/functions/futimens.html
*
* Set file access and modification times
*/
int utimensat(
int fd,
const char *path,
const struct timespec times[2],
int flag
)
{
int rv = 0;
rtems_filesystem_eval_path_context_t ctx;
int eval_flags = RTEMS_FS_FOLLOW_LINK;
const rtems_filesystem_location_info_t *currentloc = NULL;
struct timespec new_times[2];
/*
* RTEMS does not currently support operating on a real file descriptor
*/
if ( fd != AT_FDCWD ) {
rtems_set_errno_and_return_minus_one( ENOSYS );
}
/*
* RTEMS does not currently support AT_SYMLINK_NOFOLLOW
*/
if ( flag != 0 ) {
rtems_set_errno_and_return_minus_one( ENOSYS );
}
rv = rtems_filesystem_utime_update( times, new_times );
if ( rv != 0 ) {
return rv;
}
currentloc = rtems_filesystem_eval_path_start( &ctx, path, eval_flags );
rv = rtems_filesystem_utime_check_permissions( currentloc, times );
if ( rv != 0 ) {
rtems_filesystem_eval_path_cleanup( &ctx );
return rv;
}
rv = (*currentloc->mt_entry->ops->utimens_h)(
currentloc,
new_times
);
rtems_filesystem_eval_path_cleanup( &ctx );
return rv;
}
