src/imfs/imfs_dir_default.c

0001 /* SPDX-License-Identifier: BSD-2-Clause */
0002
0003 /**
0004  * @file
0005  *
0006  * @ingroup IMFS
0007  */
0008
0009 /*
0010  *  COPYRIGHT (c) 1989-1999.
0011  *  On-Line Applications Research Corporation (OAR).
0012  *
0013  * Redistribution and use in source and binary forms, with or without
0014  * modification, are permitted provided that the following conditions
0015  * are met:
0016  * 1. Redistributions of source code must retain the above copyright
0017  *    notice, this list of conditions and the following disclaimer.
0018  * 2. Redistributions in binary form must reproduce the above copyright
0019  *    notice, this list of conditions and the following disclaimer in the
0020  *    documentation and/or other materials provided with the distribution.
0021  *
0022  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
0023  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
0024  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
0025  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
0026  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
0027  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
0028  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
0029  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
0030  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
0031  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
0032  * POSSIBILITY OF SUCH DAMAGE.
0033  */
0034
0035 #ifdef HAVE_CONFIG_H
0036 #include "config.h"
0037 #endif
0038
0039 #include <rtems/imfs.h>
0040
0041 #include <sys/param.h>
0042 #include <dirent.h>
0043 #include <string.h>
0044
0045 static ssize_t IMFS_dir_read(
0046   rtems_libio_t  *iop,
0047   void           *buffer,
0048   size_t          count
0049 )
0050 {
0051   /*
0052    *  Read up to element  iop->offset in the directory chain of the
0053    *  imfs_jnode_t struct for this file descriptor.
0054    */
0055    const IMFS_directory_t    *dir;
0056    const rtems_chain_node    *node;
0057    const rtems_chain_control *entries;
0058    struct dirent             *dir_ent;
0059    ssize_t                    bytes_transferred;
0060    off_t                      current_entry;
0061    off_t                      first_entry;
0062    off_t                      last_entry;
0063
0064    rtems_filesystem_instance_lock( &iop->pathinfo );
0065
0066    dir = IMFS_iop_to_directory( iop );
0067    entries = &dir->Entries;
0068
0069    /* Move to the first of the desired directory entries */
0070
0071    bytes_transferred = 0;
0072    first_entry = iop->offset;
0073    /* protect against using sizes that are not exact multiples of the */
0074    /* -dirent- size. These could result in unexpected results          */
0075    last_entry = first_entry
0076      + (count / sizeof( *dir_ent )) * sizeof( *dir_ent );
0077
0078    /* The directory was not empty so try to move to the desired entry in chain*/
0079    for (
0080       current_entry = 0,
0081         node = rtems_chain_immutable_first( entries );
0082       current_entry < last_entry
0083         && !rtems_chain_is_tail( entries, node );
0084       current_entry +=  sizeof( *dir_ent ),
0085         node = rtems_chain_immutable_next( node )
0086    ) {
0087       if( current_entry >= first_entry ) {
0088          const IMFS_jnode_t *imfs_node = (const IMFS_jnode_t *) node;
0089
0090          dir_ent = (struct dirent *) ((char *) buffer + bytes_transferred);
0091
0092          /* Move the entry to the return buffer */
0093          dir_ent->d_off = current_entry;
0094          dir_ent->d_reclen = sizeof( *dir_ent );
0095          dir_ent->d_ino = IMFS_node_to_ino( imfs_node );
0096 #ifdef DT_DIR
0097          dir_ent->d_type = IFTODT( imfs_node->st_mode );
0098 #endif
0099          dir_ent->d_namlen =
0100            MIN( imfs_node->namelen, sizeof( dir_ent->d_name ) - 1 );
0101          dir_ent->d_name[ dir_ent->d_namlen ] = '\0';
0102          memcpy( dir_ent->d_name, imfs_node->name, dir_ent->d_namlen );
0103
0104          iop->offset += sizeof( *dir_ent );
0105          bytes_transferred += (ssize_t) sizeof( *dir_ent );
0106       }
0107    }
0108
0109    rtems_filesystem_instance_unlock( &iop->pathinfo );
0110
0111    return bytes_transferred;
0112 }
0113
0114 static size_t IMFS_directory_size( const IMFS_jnode_t *node )
0115 {
0116   size_t size = 0;
0117   const IMFS_directory_t *dir = (const IMFS_directory_t *) node;
0118   const rtems_chain_control *chain = &dir->Entries;
0119   const rtems_chain_node *current = rtems_chain_immutable_first( chain );
0120   const rtems_chain_node *tail = rtems_chain_immutable_tail( chain );
0121
0122   while ( current != tail ) {
0123     size += sizeof( struct dirent );
0124     current = rtems_chain_immutable_next( current );
0125   }
0126
0127   return size;
0128 }
0129
0130 static int IMFS_stat_directory(
0131   const rtems_filesystem_location_info_t *loc,
0132   struct stat *buf
0133 )
0134 {
0135   const IMFS_jnode_t *node = loc->node_access;
0136
0137   buf->st_size = IMFS_directory_size( node );
0138
0139   return IMFS_stat( loc, buf );
0140 }
0141
0142 static const rtems_filesystem_file_handlers_r IMFS_dir_default_handlers = {
0143   .open_h = rtems_filesystem_default_open,
0144   .close_h = rtems_filesystem_default_close,
0145   .read_h = IMFS_dir_read,
0146   .write_h = rtems_filesystem_default_write,
0147   .ioctl_h = rtems_filesystem_default_ioctl,
0148   .lseek_h = rtems_filesystem_default_lseek_directory,
0149   .fstat_h = IMFS_stat_directory,
0150   .ftruncate_h = rtems_filesystem_default_ftruncate_directory,
0151   .fsync_h = rtems_filesystem_default_fsync_or_fdatasync_success,
0152   .fdatasync_h = rtems_filesystem_default_fsync_or_fdatasync_success,
0153   .fcntl_h = rtems_filesystem_default_fcntl,
0154   .kqfilter_h = rtems_filesystem_default_kqfilter,
0155   .mmap_h = rtems_filesystem_default_mmap,
0156   .poll_h = rtems_filesystem_default_poll,
0157   .readv_h = rtems_filesystem_default_readv,
0158   .writev_h = rtems_filesystem_default_writev
0159 };
0160
0161 const IMFS_mknod_control IMFS_mknod_control_dir_default = {
0162   {
0163     .handlers = &IMFS_dir_default_handlers,
0164     .node_initialize = IMFS_node_initialize_directory,
0165     .node_remove = IMFS_node_remove_directory,
0166     .node_destroy = IMFS_node_destroy_default
0167   },
0168   .node_size = sizeof( IMFS_directory_t )
0169 };