usbloadergx/source/libntfs/ntfsfile.c

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2009-12-19 15:06:57 +01:00
/**
* ntfsfile.c - devoptab file routines for NTFS-based devices.
*
* Copyright (c) 2009 Rhys "Shareese" Koedijk
* Copyright (c) 2006 Michael "Chishm" Chisholm
*
* This program/include file is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as published
* by the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program/include file is distributed in the hope that it will be
* useful, but WITHOUT ANY WARRANTY; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#ifdef HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#ifdef HAVE_FCNTL_H
#include <fcntl.h>
#endif
#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#include "ntfsinternal.h"
#include "ntfsfile.h"
#define STATE(x) ((ntfs_file_state*)x)
void ntfsCloseFile (ntfs_file_state *file)
{
// Sanity check
if (!file || !file->vd)
return;
// Special case fix ups for compressed and/or encrypted files
if (file->compressed)
ntfs_attr_pclose(file->data_na);
#ifdef HAVE_SETXATTR
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if (file->encrypted)
ntfs_efs_fixup_attribute(NULL, file->data_na);
#endif
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// Close the file data attribute (if open)
if (file->data_na)
ntfs_attr_close(file->data_na);
// Sync the file (and its attributes) to disc
if(file->write)
ntfsSync(file->vd, file->ni);
// Close the file (if open)
if (file->ni)
ntfsCloseEntry(file->vd, file->ni);
// Reset the file state
file->ni = NULL;
file->data_na = NULL;
file->flags = 0;
file->read = false;
file->write = false;
file->append = false;
file->pos = 0;
file->len = 0;
return;
}
int ntfs_open_r (struct _reent *r, void *fileStruct, const char *path, int flags, int mode)
{
ntfs_log_trace("fileStruct %p, path %s, flags %i, mode %i\n", fileStruct, path, flags, mode);
ntfs_file_state* file = STATE(fileStruct);
// Get the volume descriptor for this path
file->vd = ntfsGetVolume(path);
if (!file->vd) {
r->_errno = ENODEV;
return -1;
}
// Lock
ntfsLock(file->vd);
// Determine which mode the file is opened for
file->flags = flags;
if ((flags & 0x03) == O_RDONLY) {
file->read = true;
file->write = false;
file->append = false;
} else if ((flags & 0x03) == O_WRONLY) {
file->read = false;
file->write = true;
file->append = (flags & O_APPEND);
} else if ((flags & 0x03) == O_RDWR) {
file->read = true;
file->write = true;
file->append = (flags & O_APPEND);
} else {
r->_errno = EACCES;
ntfsUnlock(file->vd);
return -1;
}
// Try and find the file and (if found) ensure that it is not a directory
file->ni = ntfsOpenEntry(file->vd, path);
if (file->ni && (file->ni->mrec->flags & MFT_RECORD_IS_DIRECTORY)) {
ntfsCloseEntry(file->vd, file->ni);
ntfsUnlock(file->vd);
r->_errno = EISDIR;
return -1;
}
// Are we creating this file?
if (flags & O_CREAT) {
// The file SHOULD NOT already exist
if (file->ni) {
ntfsCloseEntry(file->vd, file->ni);
ntfsUnlock(file->vd);
r->_errno = EEXIST;
return -1;
}
// Create the file
file->ni = ntfsCreate(file->vd, path, S_IFREG, NULL);
if (!file->ni) {
ntfsUnlock(file->vd);
return -1;
}
}
// Sanity check, the file should be open by now
if (!file->ni) {
ntfsUnlock(file->vd);
r->_errno = ENOENT;
return -1;
}
// Open the files data attribute
file->data_na = ntfs_attr_open(file->ni, AT_DATA, AT_UNNAMED, 0);
if(!file->data_na) {
ntfsCloseEntry(file->vd, file->ni);
ntfsUnlock(file->vd);
return -1;
}
// Determine if this files data is compressed and/or encrypted
file->compressed = NAttrCompressed(file->data_na) || (file->ni->flags & FILE_ATTR_COMPRESSED);
file->encrypted = NAttrEncrypted(file->data_na) || (file->ni->flags & FILE_ATTR_ENCRYPTED);
// We cannot read/write encrypted files
if (file->encrypted) {
ntfs_attr_close(file->data_na);
ntfsCloseEntry(file->vd, file->ni);
ntfsUnlock(file->vd);
r->_errno = EACCES;
return -1;
}
// Make sure we aren't trying to write to a read-only file
if ((file->ni->flags & FILE_ATTR_READONLY) && file->write) {
ntfs_attr_close(file->data_na);
ntfsCloseEntry(file->vd, file->ni);
ntfsUnlock(file->vd);
r->_errno = EROFS;
return -1;
}
// Truncate the file if requested
if ((flags & O_TRUNC) && file->write) {
if (ntfs_attr_truncate(file->data_na, 0)) {
ntfs_attr_close(file->data_na);
ntfsCloseEntry(file->vd, file->ni);
ntfsUnlock(file->vd);
r->_errno = errno;
return -1;
}
}
// Set the files current position and length
file->pos = 0;
file->len = file->data_na->data_size;
ntfs_log_trace("file->len %d\n", file->len);
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// Update file times
ntfsUpdateTimes(file->vd, file->ni, NTFS_UPDATE_ATIME);
// Insert the file into the double-linked FILO list of open files
if (file->vd->firstOpenFile) {
file->nextOpenFile = file->vd->firstOpenFile;
file->vd->firstOpenFile->prevOpenFile = file;
} else {
file->nextOpenFile = NULL;
}
file->prevOpenFile = NULL;
file->vd->firstOpenFile = file;
file->vd->openFileCount++;
// Unlock
ntfsUnlock(file->vd);
return (int)fileStruct;
}
int ntfs_close_r (struct _reent *r, int fd)
{
ntfs_log_trace("fd %p\n", fd);
ntfs_file_state* file = STATE(fd);
// Sanity check
if (!file || !file->vd) {
r->_errno = EBADF;
return -1;
}
// Lock
ntfsLock(file->vd);
// Close the file
ntfsCloseFile(file);
// Remove the file from the double-linked FILO list of open files
file->vd->openFileCount--;
if (file->nextOpenFile)
file->nextOpenFile->prevOpenFile = file->prevOpenFile;
if (file->prevOpenFile)
file->prevOpenFile->nextOpenFile = file->nextOpenFile;
else
file->vd->firstOpenFile = file->nextOpenFile;
// Unlock
ntfsUnlock(file->vd);
return 0;
}
ssize_t ntfs_write_r (struct _reent *r, int fd, const char *ptr, size_t len)
{
ntfs_log_trace("fd %p, ptr %p, len %Li\n", fd, ptr, len);
ntfs_file_state* file = STATE(fd);
ssize_t written = 0;
off_t old_pos = 0;
// Sanity check
if (!file || !file->vd || !file->ni || !file->data_na) {
r->_errno = EINVAL;
return -1;
}
// Short circuit cases where we don't actually have to do anything
if (!ptr || len <= 0) {
return 0;
}
// Lock
ntfsLock(file->vd);
// Check that we are allowed to write to this file
if (!file->write) {
ntfsUnlock(file->vd);
r->_errno = EACCES;
return -1;
}
// If we are in append mode, backup the current position and move to the end of the file
if (file->append) {
old_pos = file->pos;
file->pos = file->len;
}
// Write to the files data atrribute
while (len) {
ssize_t ret = ntfs_attr_pwrite(file->data_na, file->pos, len, ptr);
if (ret <= 0) {
ntfsUnlock(file->vd);
r->_errno = errno;
return -1;
}
len -= ret;
file->pos += ret;
written += ret;
}
// If we are in append mode, restore the current position to were it was prior to this write
if (file->append) {
file->pos = old_pos;
}
// Mark the file for archiving (if we actually wrote something)
if (written)
file->ni->flags |= FILE_ATTR_ARCHIVE;
// Update file times (if we actually wrote something)
if (written)
ntfsUpdateTimes(file->vd, file->ni, NTFS_UPDATE_MCTIME);
// Update the files data length
file->len = file->data_na->data_size;
// Unlock
ntfsUnlock(file->vd);
return written;
}
ssize_t ntfs_read_r (struct _reent *r, int fd, char *ptr, size_t len)
{
ntfs_log_trace("fd %p, ptr %p, len %Li\n", fd, ptr, len);
ntfs_file_state* file = STATE(fd);
ssize_t read = 0;
// Sanity check
if (!file || !file->vd || !file->ni || !file->data_na) {
r->_errno = EINVAL;
return -1;
}
// Short circuit cases where we don't actually have to do anything
if (!ptr || len <= 0) {
return 0;
}
// Lock
ntfsLock(file->vd);
// Check that we are allowed to read from this file
if (!file->read) {
ntfsUnlock(file->vd);
r->_errno = EACCES;
return -1;
}
// Don't read past the end of file
if (file->pos + len > file->len) {
r->_errno = EOVERFLOW;
len = file->len - file->pos;
ntfs_log_trace("EOVERFLOW");
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}
ntfs_log_trace("file->pos:%d, len:%d, file->len:%d \n", (u32)file->pos, (u32)len, (u32)file->len);
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// Read from the files data attribute
while (len) {
ssize_t ret = ntfs_attr_pread(file->data_na, file->pos, len, ptr);
if (ret <= 0 || ret > len) {
ntfsUnlock(file->vd);
r->_errno = errno;
return -1;
}
ptr += ret;
len -= ret;
file->pos += ret;
read += ret;
}
//ntfs_log_trace("file->pos: %d \n", (u32)file->pos);
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// Update file times (if we actually read something)
if (read)
ntfsUpdateTimes(file->vd, file->ni, NTFS_UPDATE_ATIME);
// Unlock
ntfsUnlock(file->vd);
return read;
}
off_t ntfs_seek_r (struct _reent *r, int fd, off_t pos, int dir)
{
ntfs_log_trace("fd %p, pos %Li, dir %i\n", fd, pos, dir);
ntfs_file_state* file = STATE(fd);
off_t position = 0;
// Sanity check
if (!file || !file->vd || !file->ni || !file->data_na) {
r->_errno = EINVAL;
return -1;
}
// Lock
ntfsLock(file->vd);
// Set the files current position
switch(dir) {
case SEEK_SET: position = file->pos = MIN(MAX(pos, 0), file->len); break;
case SEEK_CUR: position = file->pos = MIN(MAX(file->pos + pos, 0), file->len); break;
case SEEK_END: position = file->pos = MIN(MAX(file->len + pos, 0), file->len); break;
}
// Unlock
ntfsUnlock(file->vd);
return position;
}
int ntfs_fstat_r (struct _reent *r, int fd, struct stat *st)
{
ntfs_log_trace("fd %p\n", fd);
ntfs_file_state* file = STATE(fd);
int ret = 0;
// Sanity check
if (!file || !file->vd || !file->ni || !file->data_na) {
r->_errno = EINVAL;
return -1;
}
// Short circuit cases were we don't actually have to do anything
if (!st)
return 0;
// Get the file stats
ret = ntfsStat(file->vd, file->ni, st);
if (ret)
r->_errno = errno;
return ret;
}
int ntfs_ftruncate_r (struct _reent *r, int fd, off_t len)
{
ntfs_log_trace("fd %p, len %Li\n", fd, len);
ntfs_file_state* file = STATE(fd);
// Sanity check
if (!file || !file->vd || !file->ni || !file->data_na) {
r->_errno = EINVAL;
return -1;
}
// Lock
ntfsLock(file->vd);
// Check that we are allowed to write to this file
if (!file->write) {
ntfsUnlock(file->vd);
r->_errno = EACCES;
return -1;
}
// For compressed files, only deleting and expanding contents are implemented
if (file->compressed &&
len > 0 &&
len < file->data_na->initialized_size) {
ntfsUnlock(file->vd);
r->_errno = EOPNOTSUPP;
return -1;
}
// Resize the files data attribute, either by expanding or truncating
if (file->compressed && len > file->data_na->initialized_size) {
char zero = 0;
if (ntfs_attr_pwrite(file->data_na, len - 1, 1, &zero) <= 0) {
ntfsUnlock(file->vd);
r->_errno = errno;
return -1;
}
} else {
if (ntfs_attr_truncate(file->data_na, len)) {
ntfsUnlock(file->vd);
r->_errno = errno;
return -1;
}
}
// Mark the file for archiving (if we actually changed something)
if (file->len != file->data_na->data_size)
file->ni->flags |= FILE_ATTR_ARCHIVE;
// Update file times (if we actually changed something)
if (file->len != file->data_na->data_size)
ntfsUpdateTimes(file->vd, file->ni, NTFS_UPDATE_MCTIME);
// Update the files data length
file->len = file->data_na->data_size;
// Sync the file (and its attributes) to disc
ntfsSync(file->vd, file->ni);
// Unlock
ntfsUnlock(file->vd);
return 0;
}
int ntfs_fsync_r (struct _reent *r, int fd)
{
ntfs_log_trace("fd %p\n", fd);
ntfs_file_state* file = STATE(fd);
int ret = 0;
// Sanity check
if (!file || !file->vd || !file->ni || !file->data_na) {
r->_errno = EINVAL;
return -1;
}
// Lock
ntfsLock(file->vd);
// Sync the file (and its attributes) to disc
ret = ntfsSync(file->vd, file->ni);
if (ret)
r->_errno = errno;
// Unlock
ntfsUnlock(file->vd);
return ret;
}