/*
* MSDOS directory handlers implementation
*
* Copyright (C) 2001 OKTET Ltd., St.-Petersburg, Russia
* Author: Eugeny S. Mints <Eugeny.Mints@oktet.ru>
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.com/license/LICENSE.
*
* @(#) $Id$
*/
#if HAVE_CONFIG_H
#include "config.h"
#endif
#include <ctype.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <rtems/libio_.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <dirent.h>
#include "fat.h"
#include "fat_fat_operations.h"
#include "fat_file.h"
#include "msdos.h"
/* msdos_dir_open --
* Open fat-file which correspondes to the directory being opened and
* set offset field of file control block to zero.
*/
int
msdos_dir_open(rtems_libio_t *iop, const char *pathname, int oflag,
mode_t mode)
{
int rc = RC_OK;
rtems_status_code sc = RTEMS_SUCCESSFUL;
msdos_fs_info_t *fs_info = iop->pathinfo.mt_entry->fs_info;
fat_file_fd_t *fat_fd = iop->pathinfo.node_access;
sc = rtems_semaphore_obtain(fs_info->vol_sema, RTEMS_WAIT,
MSDOS_VOLUME_SEMAPHORE_TIMEOUT);
if (sc != RTEMS_SUCCESSFUL)
rtems_set_errno_and_return_minus_one( EIO );
rc = fat_file_reopen(fat_fd);
if (rc != RC_OK)
{
rtems_semaphore_release(fs_info->vol_sema);
return rc;
}
iop->offset = 0;
rtems_semaphore_release(fs_info->vol_sema);
return RC_OK;
}
/* msdos_dir_close --
* Close fat-file which correspondes to the directory being closed
*
* PARAMETERS:
* iop - file control block
*
* RETURNS:
* RC_OK, if directory closed successfully, or -1 if error occured (errno
* set apropriately.
*/
int
msdos_dir_close(rtems_libio_t *iop)
{
int rc = RC_OK;
rtems_status_code sc = RTEMS_SUCCESSFUL;
msdos_fs_info_t *fs_info = iop->pathinfo.mt_entry->fs_info;
fat_file_fd_t *fat_fd = iop->pathinfo.node_access;
sc = rtems_semaphore_obtain(fs_info->vol_sema, RTEMS_WAIT,
MSDOS_VOLUME_SEMAPHORE_TIMEOUT);
if (sc != RTEMS_SUCCESSFUL)
rtems_set_errno_and_return_minus_one( EIO );
rc = fat_file_close(iop->pathinfo.mt_entry, fat_fd);
if (rc != RC_OK)
{
rtems_semaphore_release(fs_info->vol_sema);
return rc;
}
rtems_semaphore_release(fs_info->vol_sema);
return RC_OK;
}
/* msdos_format_dirent_with_dot --
* This routine convert a (short) MSDOS filename as present on disk
* (fixed 8+3 characters, filled with blanks, without separator dot)
* to a "normal" format, with between 0 and 8 name chars,
* a separating dot and up to 3 extension characters
* Rules to work:
* - copy any (0-8) "name" part characters that are non-blank
* - if an extension exists, append a dot
* - copy any (0-3) non-blank extension characters
* - append a '\0' (dont count it for the rturn code
*
* PARAMETERS:
* dst: pointer to destination char array (must be big enough)
* src: pointer to source characters
*
*
* RETURNS:
* the number of bytes (without trailing '\0'(written to destination
*/
static ssize_t
msdos_format_dirent_with_dot(char *dst,const char *src)
{
ssize_t len;
int i;
const char *src_tmp;
/*
* find last non-blank character of base name
*/
for ((i = MSDOS_SHORT_BASE_LEN ,
src_tmp = src + MSDOS_SHORT_BASE_LEN-1);
((i > 0) &&
(*src_tmp == ' '));
i--,src_tmp--)
{};
/*
* copy base name to destination
*/
src_tmp = src;
len = i;
while (i-- > 0) {
*dst++ = tolower((unsigned char)(*src_tmp++));
}
/*
* find last non-blank character of extension
*/
for ((i = MSDOS_SHORT_EXT_LEN ,
src_tmp = src + MSDOS_SHORT_BASE_LEN+MSDOS_SHORT_EXT_LEN-1);
((i > 0) &&
(*src_tmp == ' '));
i--,src_tmp--)
{};
/*
* extension is not empty
*/
if (i > 0) {
*dst++ = '.'; /* append dot */
len += i + 1; /* extension + dot */
src_tmp = src + MSDOS_SHORT_BASE_LEN;
while (i-- > 0) {
*dst++ = tolower((unsigned char)(*src_tmp++));
len++;
}
}
*dst = '\0'; /* terminate string */
return len;
}
/* msdos_dir_read --
* This routine will read the next directory entry based on the directory
* offset. The offset should be equal to -n- time the size of an
* individual dirent structure. If n is not an integer multiple of the
* sizeof a dirent structure, an integer division will be performed to
* determine directory entry that will be returned in the buffer. Count
* should reflect -m- times the sizeof dirent bytes to be placed in the
* buffer.
* If there are not -m- dirent elements from the current directory
* position to the end of the exisiting file, the remaining entries will
* be placed in the buffer and the returned value will be equal to
* -m actual- times the size of a directory entry.
*
* PARAMETERS:
* iop - file control block
* buffer - buffer provided by user
* count - count of bytes to read
*
* RETURNS:
* the number of bytes read on success, or -1 if error occured (errno
* set apropriately).
*/
ssize_t
msdos_dir_read(rtems_libio_t *iop, void *buffer, size_t count)
{
int rc = RC_OK;
rtems_status_code sc = RTEMS_SUCCESSFUL;
msdos_fs_info_t *fs_info = iop->pathinfo.mt_entry->fs_info;
fat_file_fd_t *fat_fd = iop->pathinfo.node_access;
fat_file_fd_t *tmp_fat_fd = NULL;
struct dirent tmp_dirent;
uint32_t start = 0;
ssize_t ret = 0;
uint32_t cmpltd = 0;
uint32_t j = 0, i = 0;
uint32_t bts2rd = 0;
uint32_t cur_cln = 0;
uint32_t lfn_start = FAT_FILE_SHORT_NAME;
uint8_t lfn_checksum = 0;
int lfn_entries = 0;
/*
* cast start and count - protect against using sizes that are not exact
* multiples of the -dirent- size. These could result in unexpected
* results
*/
start = iop->offset / sizeof(struct dirent);
count = (count / sizeof(struct dirent)) * sizeof(struct dirent);
/*
* optimization: we know that root directory for FAT12/16 volumes is
* sequential set of sectors and any cluster is sequential set of sectors
* too, so read such set of sectors is quick operation for low-level IO
* layer.
*/
bts2rd = (FAT_FD_OF_ROOT_DIR(fat_fd) &&
(fs_info->fat.vol.type & (FAT_FAT12 | FAT_FAT16))) ?
fat_fd->fat_file_size :
fs_info->fat.vol.bpc;
sc = rtems_semaphore_obtain(fs_info->vol_sema, RTEMS_WAIT,
MSDOS_VOLUME_SEMAPHORE_TIMEOUT);
if (sc != RTEMS_SUCCESSFUL)
rtems_set_errno_and_return_minus_one(EIO);
while (count > 0)
{
/*
* fat-file is already opened by open call, so read it
* Always read directory fat-file from the beggining because of MSDOS
* directories feature :( - we should count elements currently
* present in the directory because there may be holes :)
*/
ret = fat_file_read(iop->pathinfo.mt_entry, fat_fd, (j * bts2rd),
bts2rd, fs_info->cl_buf);
if (ret < MSDOS_DIRECTORY_ENTRY_STRUCT_SIZE)
{
rtems_semaphore_release(fs_info->vol_sema);
rtems_set_errno_and_return_minus_one(EIO);
}
for (i = 0; i < ret; i += MSDOS_DIRECTORY_ENTRY_STRUCT_SIZE)
{
char* entry = (char*) fs_info->cl_buf + i;
/*
* Is this directory from here on empty ?
*/
if ((*MSDOS_DIR_ENTRY_TYPE(entry)) ==
MSDOS_THIS_DIR_ENTRY_AND_REST_EMPTY)
{
rtems_semaphore_release(fs_info->vol_sema);
return cmpltd;
}
/* Is the directory entry empty */
if ((*MSDOS_DIR_ENTRY_TYPE(entry)) == MSDOS_THIS_DIR_ENTRY_EMPTY)
continue;
/* Is the directory entry empty a volume label */
if (((*MSDOS_DIR_ATTR(entry)) & MSDOS_ATTR_VOLUME_ID) &&
((*MSDOS_DIR_ATTR(entry) & MSDOS_ATTR_LFN_MASK) != MSDOS_ATTR_LFN))
continue;
/*
* Check the attribute to see if the entry is for a long file
* name.
*/
if ((*MSDOS_DIR_ATTR(entry) & MSDOS_ATTR_LFN_MASK) ==
MSDOS_ATTR_LFN)
{
int o;
char* p;
int q;
/*
* Is this is the first entry of a LFN ?
*/
if (lfn_start == FAT_FILE_SHORT_NAME)
{
/*
* The first entry must have the last long entry flag set.
*/
if ((*MSDOS_DIR_ENTRY_TYPE(entry) &
MSDOS_LAST_LONG_ENTRY) == 0)
continue;
/*
* Remember the start location of the long file name.
*/
lfn_start =
((j * bts2rd) + i) / MSDOS_DIRECTORY_ENTRY_STRUCT_SIZE;
/*
* Get the number of entries so we can count down and
* also the checksum of the short entry.
*/
lfn_entries = (*MSDOS_DIR_ENTRY_TYPE(entry) &
MSDOS_LAST_LONG_ENTRY_MASK);
lfn_checksum = *MSDOS_DIR_LFN_CHECKSUM(entry);
memset (tmp_dirent.d_name, 0, sizeof(tmp_dirent.d_name));
}
/*
* If the entry number or the check sum do not match
* forget this series of long directory entries. These could
* be orphaned entries depending on the history of the
* disk.
*/
if ((lfn_entries != (*MSDOS_DIR_ENTRY_TYPE(entry) &
MSDOS_LAST_LONG_ENTRY_MASK)) ||
(lfn_checksum != *MSDOS_DIR_LFN_CHECKSUM(entry)))
{
lfn_start = FAT_FILE_SHORT_NAME;
continue;
}
/*
* Extract the file name into the directory entry. The data is
* stored in UNICODE characters (16bit). No translation is
* currently supported.
*
* The DOS maximum length is 255 characters without the
* trailing nul character. We need to range check the length to
* fit in the directory entry name field.
*/
lfn_entries--;
p = entry + 1;
o = lfn_entries * MSDOS_LFN_LEN_PER_ENTRY;
for (q = 0; q < MSDOS_LFN_LEN_PER_ENTRY; q++)
{
if (o >= (sizeof(tmp_dirent.d_name) - 1))
break;
tmp_dirent.d_name[o++] = *p;
if (*p == '\0')
break;
switch (q)
{
case 4:
p += 5;
break;
case 10:
p += 4;
break;
default:
p += 2;
break;
}
}
}
else
{
fat_dir_pos_t dir_pos;
/*
* Skip active entries until get the entry to start from.
*/
if (start)
{
lfn_start = FAT_FILE_SHORT_NAME;
start--;
continue;
}
/*
* Move the entry to the return buffer
*
* unfortunately there is no method to extract ino except to
* open fat-file descriptor :( ... so, open it
*/
/* get number of cluster we are working with */
rc = fat_file_ioctl(iop->pathinfo.mt_entry, fat_fd, F_CLU_NUM,
j * bts2rd, &cur_cln);
if (rc != RC_OK)
{
rtems_semaphore_release(fs_info->vol_sema);
return rc;
}
fat_dir_pos_init(&dir_pos);
dir_pos.sname.cln = cur_cln;
dir_pos.sname.ofs = i;
rc = fat_file_open(iop->pathinfo.mt_entry, &dir_pos, &tmp_fat_fd);
if (rc != RC_OK)
{
rtems_semaphore_release(fs_info->vol_sema);
return rc;
}
/* fill in dirent structure */
/* XXX: from what and in what d_off should be computed ?! */
tmp_dirent.d_off = start + cmpltd;
tmp_dirent.d_reclen = sizeof(struct dirent);
tmp_dirent.d_ino = tmp_fat_fd->ino;
/*
* If a long file name check if the correct number of
* entries have been found and if the checksum is correct.
* If not return the short file name.
*/
if (lfn_start != FAT_FILE_SHORT_NAME)
{
uint8_t cs = 0;
uint8_t* p = (uint8_t*) entry;
int i;
for (i = 0; i < 11; i++, p++)
cs = ((cs & 1) ? 0x80 : 0) + (cs >> 1) + *p;
if (lfn_entries || (lfn_checksum != cs))
lfn_start = FAT_FILE_SHORT_NAME;
}
if (lfn_start == FAT_FILE_SHORT_NAME)
{
/*
* convert dir entry from fixed 8+3 format (without dot)
* to 0..8 + 1dot + 0..3 format
*/
tmp_dirent.d_namlen = msdos_format_dirent_with_dot(
tmp_dirent.d_name, entry); /* src text */
}
else
{
tmp_dirent.d_namlen = strlen(tmp_dirent.d_name);
}
memcpy(buffer + cmpltd, &tmp_dirent, sizeof(struct dirent));
iop->offset = iop->offset + sizeof(struct dirent);
cmpltd += (sizeof(struct dirent));
count -= (sizeof(struct dirent));
/* inode number extracted, close fat-file */
rc = fat_file_close(iop->pathinfo.mt_entry, tmp_fat_fd);
if (rc != RC_OK)
{
rtems_semaphore_release(fs_info->vol_sema);
return rc;
}
}
if (count <= 0)
break;
}
j++;
}
rtems_semaphore_release(fs_info->vol_sema);
return cmpltd;
}
/* msdos_dir_write --
* no write for directory
*/
/* msdos_dir_stat --
*
* This routine will obtain the following information concerning the current
* directory:
* st_dev device id
* st_ino node serial number :)
* st_mode mode extracted from the node
* st_size total size in bytes
* st_blksize blocksize for filesystem I/O
* st_blocks number of blocks allocated
* stat_mtime time of last modification
*
* PARAMETERS:
* loc - this directory
* buf - stat buffer provided by user
*
* RETURNS:
* RC_OK and filled stat buffer on success, or -1 if error occured (errno
* set apropriately).
*/
int
msdos_dir_stat(
const rtems_filesystem_location_info_t *loc,
struct stat *buf
)
{
rtems_status_code sc = RTEMS_SUCCESSFUL;
msdos_fs_info_t *fs_info = loc->mt_entry->fs_info;
fat_file_fd_t *fat_fd = loc->node_access;
sc = rtems_semaphore_obtain(fs_info->vol_sema, RTEMS_WAIT,
MSDOS_VOLUME_SEMAPHORE_TIMEOUT);
if (sc != RTEMS_SUCCESSFUL)
rtems_set_errno_and_return_minus_one(EIO);
buf->st_dev = rtems_disk_get_device_identifier(fs_info->fat.vol.dd);
buf->st_ino = fat_fd->ino;
buf->st_mode = S_IFDIR | S_IRWXU | S_IRWXG | S_IRWXO;
buf->st_rdev = 0ll;
buf->st_size = fat_fd->fat_file_size;
buf->st_blocks = fat_fd->fat_file_size >> FAT_SECTOR512_BITS;
buf->st_blksize = fs_info->fat.vol.bps;
buf->st_mtime = fat_fd->mtime;
rtems_semaphore_release(fs_info->vol_sema);
return RC_OK;
}
/* msdos_dir_truncate --
* No truncate for directory.
*
* PARAMETERS:
*
* RETURNS:
*
*/
/* msdos_dir_sync --
* The following routine does a syncronization on a MSDOS directory node.
* DIR_WrtTime, DIR_WrtDate and DIR_fileSize fields of 32 Bytes Directory
* Entry Structure should not be updated for directories, so only call
* to corresponding fat-file routine.
*
* PARAMETERS:
* iop - file control block
*
* RETURNS:
* RC_OK on success, or -1 if error occured (errno set apropriately).
*/
int
msdos_dir_sync(rtems_libio_t *iop)
{
int rc = RC_OK;
rtems_status_code sc = RTEMS_SUCCESSFUL;
fat_file_fd_t *fat_fd = iop->pathinfo.node_access;
msdos_fs_info_t *fs_info = iop->pathinfo.mt_entry->fs_info;
sc = rtems_semaphore_obtain(fs_info->vol_sema, RTEMS_WAIT,
MSDOS_VOLUME_SEMAPHORE_TIMEOUT);
if (sc != RTEMS_SUCCESSFUL)
rtems_set_errno_and_return_minus_one(EIO);
rc = fat_file_datasync(iop->pathinfo.mt_entry, fat_fd);
rtems_semaphore_release(fs_info->vol_sema);
return rc;
}
