diff options
Diffstat (limited to 'cpukit/libcsupport/src/utimensat.c')
| -rw-r--r-- | cpukit/libcsupport/src/utimensat.c | 225 |
1 files changed, 225 insertions, 0 deletions
diff --git a/cpukit/libcsupport/src/utimensat.c b/cpukit/libcsupport/src/utimensat.c new file mode 100644 index 0000000000..c053218ad0 --- /dev/null +++ b/cpukit/libcsupport/src/utimensat.c @@ -0,0 +1,225 @@ +/* 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; +} |