libcsupport/src/fchown.c

0001 /* SPDX-License-Identifier: BSD-2-Clause */
0002
0003 /**
0004  *  @file
0005  *
0006  *  @brief Change Owner and Group of a File
0007  *  @ingroup libcsupport
0008  */
0009
0010 /*
0011  *  COPYRIGHT (c) 1989-1999.
0012  *  On-Line Applications Research Corporation (OAR).
0013  *
0014  * Redistribution and use in source and binary forms, with or without
0015  * modification, are permitted provided that the following conditions
0016  * are met:
0017  * 1. Redistributions of source code must retain the above copyright
0018  *    notice, this list of conditions and the following disclaimer.
0019  * 2. Redistributions in binary form must reproduce the above copyright
0020  *    notice, this list of conditions and the following disclaimer in the
0021  *    documentation and/or other materials provided with the distribution.
0022  *
0023  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
0024  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
0025  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
0026  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
0027  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
0028  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
0029  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
0030  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
0031  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
0032  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
0033  * POSSIBILITY OF SUCH DAMAGE.
0034  */
0035
0036 #ifdef HAVE_CONFIG_H
0037 #include "config.h"
0038 #endif
0039
0040 #include <string.h>
0041 #include <unistd.h>
0042
0043 #include <rtems/libio_.h>
0044
0045 int rtems_filesystem_chown(
0046   const rtems_filesystem_location_info_t *loc,
0047   uid_t owner,
0048   gid_t group
0049 )
0050 {
0051   const rtems_filesystem_mount_table_entry_t *mt_entry = loc->mt_entry;
0052   int rv;
0053
0054   if ( mt_entry->writeable || rtems_filesystem_location_is_null( loc ) ) {
0055     struct stat st;
0056
0057     memset( &st, 0, sizeof(st) );
0058
0059     rv = (*loc->handlers->fstat_h)( loc, &st );
0060     if ( rv == 0 ) {
0061       uid_t uid = geteuid();
0062
0063       if ( uid == 0 || st.st_uid == uid ) {
0064         rv = (*mt_entry->ops->chown_h)( loc, owner, group );
0065       } else {
0066         errno = EPERM;
0067         rv = -1;
0068       }
0069     }
0070   } else {
0071     errno = EROFS;
0072     rv = -1;
0073   }
0074
0075   return rv;
0076 }
0077
0078 /**
0079  *  POSIX 1003.1b 5.6.5 - Change Owner and Group of a File
0080  */
0081 int fchown( int fd, uid_t owner, gid_t group )
0082 {
0083   int rv;
0084   rtems_libio_t *iop;
0085
0086   LIBIO_GET_IOP( fd, iop );
0087
0088   rtems_filesystem_instance_lock( &iop->pathinfo );
0089
0090   rv = rtems_filesystem_chown( &iop->pathinfo, owner, group );
0091
0092   rtems_filesystem_instance_unlock( &iop->pathinfo );
0093
0094   rtems_libio_iop_drop( iop );
0095
0096   return rv;
0097 }