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 /* 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;
 }

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