CfgUSBLoader/lib/libext2fs/source/ext2dir.c
2015-01-17 10:11:08 +00:00

658 lines
14 KiB
C

/**
* ext2_dir.c - devoptab directory routines for EXT2-based devices.
*
* Copyright (c) 2006 Michael "Chishm" Chisholm
* Copyright (c) 2009 Rhys "Shareese" Koedijk
* Copyright (c) 2010 Dimok
*
* 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_STATVFS_H
#include <sys/statvfs.h>
#endif
#ifdef HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#include "ext2_internal.h"
#include "ext2dir.h"
#include <sys/dir.h>
#define STATE(x) ((ext2_dir_state*)(x)->dirStruct)
void ext2CloseDir (ext2_dir_state *dir)
{
// Sanity check
if (!dir || !dir->vd)
return;
// Free the directory entries (if any)
while (dir->first) {
ext2_dir_entry *next = dir->first->next;
mem_free(dir->first->name);
mem_free(dir->first);
dir->first = next;
}
// Close the directory (if open)
if (dir->ni)
ext2CloseEntry(dir->vd, dir->ni);
// Reset the directory state
dir->ni = NULL;
dir->first = NULL;
dir->current = NULL;
return;
}
int ext2_stat_r (struct _reent *r, const char *path, struct stat *st)
{
// Short circuit cases were we don't actually have to do anything
if (!st || !path)
return 0;
ext2_log_trace("path %s, st %p\n", path, st);
ext2_vd *vd = NULL;
ext2_inode_t *ni = NULL;
// Get the volume descriptor for this path
vd = ext2GetVolume(path);
if (!vd) {
r->_errno = ENODEV;
return -1;
}
if(strcmp(path, ".") == 0 || strcmp(path, "..") == 0)
{
memset(st, 0, sizeof(struct stat));
st->st_mode = S_IFDIR;
return 0;
}
// Lock
ext2Lock(vd);
// Find the entry
ni = ext2OpenEntry(vd, path);
if (!ni) {
r->_errno = errno;
ext2Unlock(vd);
return -1;
}
// Get the entry stats
int ret = ext2Stat(vd, ni, st);
if (ret)
r->_errno = errno;
// Close the entry
ext2CloseEntry(vd, ni);
ext2Unlock(vd);
return 0;
}
int ext2_link_r (struct _reent *r, const char *existing, const char *newLink)
{
ext2_log_trace("existing %s, newLink %s\n", existing, newLink);
ext2_vd *vd = NULL;
ext2_inode_t *ni = NULL;
// Get the volume descriptor for this path
vd = ext2GetVolume(existing);
if (!vd) {
r->_errno = ENODEV;
return -1;
}
// Lock
ext2Lock(vd);
// Create a symbolic link between the two paths
ni = ext2Create(vd, existing, S_IFLNK, newLink);
if (!ni) {
ext2Unlock(vd);
r->_errno = errno;
return -1;
}
// Close the symbolic link
ext2CloseEntry(vd, ni);
// Unlock
ext2Unlock(vd);
return 0;
}
int ext2_unlink_r (struct _reent *r, const char *name)
{
ext2_log_trace("name %s\n", name);
ext2_vd *vd = NULL;
// Get the volume descriptor for this path
vd = ext2GetVolume(name);
if (!vd) {
r->_errno = ENODEV;
return -1;
}
// Unlink the entry
int ret = ext2Unlink(vd, name);
if (ret)
r->_errno = errno;
return ret;
}
int ext2_chdir_r (struct _reent *r, const char *name)
{
ext2_log_trace("name %s\n", name);
ext2_vd *vd = NULL;
ext2_inode_t *ni = NULL;
// Get the volume descriptor for this path
vd = ext2GetVolume(name);
if (!vd) {
r->_errno = ENODEV;
return -1;
}
// Lock
ext2Lock(vd);
// Find the directory
ni = ext2OpenEntry(vd, name);
if (!ni) {
ext2Unlock(vd);
r->_errno = ENOENT;
return -1;
}
// Ensure that this directory is indeed a directory
if (!LINUX_S_ISDIR(ni->ni.i_mode)) {
ext2CloseEntry(vd, ni);
ext2Unlock(vd);
r->_errno = ENOTDIR;
return -1;
}
// Close the old current directory (if any)
if (vd->cwd_ni)
ext2CloseEntry(vd, vd->cwd_ni);
// Set the new current directory
vd->cwd_ni = ni;
// Unlock
ext2Unlock(vd);
return 0;
}
int ext2_rename_r (struct _reent *r, const char *oldName, const char *newName)
{
ext2_log_trace("oldName %s, newName %s\n", oldName, newName);
ext2_vd *vd = NULL;
ext2_inode_t *ni = NULL;
// Get the volume descriptor for this path
vd = ext2GetVolume(oldName);
if (!vd) {
r->_errno = ENODEV;
return -1;
}
// Lock
ext2Lock(vd);
// You cannot rename between devices
if(vd != ext2GetVolume(newName)) {
ext2Unlock(vd);
r->_errno = EXDEV;
return -1;
}
// Check that there is no existing entry with the new name
ni = ext2OpenEntry(vd, newName);
if (ni) {
ext2CloseEntry(vd, ni);
ext2Unlock(vd);
r->_errno = EEXIST;
return -1;
}
// Link the old entry with the new one
if (ext2Link(vd, oldName, newName)) {
ext2Unlock(vd);
return -1;
}
// Unlink the old entry
if (ext2Unlink(vd, oldName)) {
if (ext2Unlink(vd, newName)) {
ext2Unlock(vd);
return -1;
}
ext2Unlock(vd);
return -1;
}
// Unlock
ext2Unlock(vd);
return 0;
}
int ext2_mkdir_r (struct _reent *r, const char *path, int mode)
{
ext2_log_trace("path %s, mode %i\n", path, mode);
ext2_vd *vd = NULL;
ext2_inode_t *ni = NULL;
// Get the volume descriptor for this path
vd = ext2GetVolume(path);
if (!vd) {
r->_errno = ENODEV;
return -1;
}
// Lock
ext2Lock(vd);
// Create the directory
ni = ext2Create(vd, path, S_IFDIR, NULL);
if (!ni) {
ext2Unlock(vd);
r->_errno = errno;
return -1;
}
// Close the directory
ext2CloseEntry(vd, ni);
// Unlock
ext2Unlock(vd);
return 0;
}
int ext2_statvfs_r (struct _reent *r, const char *path, struct statvfs *buf)
{
ext2_log_trace("path %s, buf %p\n", path, buf);
ext2_vd *vd = NULL;
// Get the volume descriptor for this path
vd = ext2GetVolume(path);
if (!vd) {
r->_errno = ENODEV;
return -1;
}
// Short circuit cases were we don't actually have to do anything
if (!buf)
return 0;
// Lock
ext2Lock(vd);
// Zero out the stat buffer
memset(buf, 0, sizeof(struct statvfs));
// File system block size
switch(vd->fs->super->s_log_block_size)
{
case 1:
buf->f_bsize = 2048;
break;
case 2:
buf->f_bsize = 4096;
break;
case 3:
buf->f_bsize = 8192;
break;
default:
case 0:
buf->f_bsize = 1024;
break;
}
// Fundamental file system block size
buf->f_frsize = buf->f_bsize;
// Total number of blocks on file system in units of f_frsize
buf->f_blocks = vd->fs->super->s_blocks_count | (((u64) vd->fs->super->s_blocks_count_hi) << 32);
// Free blocks available for all and for non-privileged processes
buf->f_bfree = vd->fs->super->s_free_blocks_count | (((u64) vd->fs->super->s_free_blocks_hi) << 32);
// Number of inodes at this point in time
buf->f_files = vd->fs->super->s_inodes_count;
// Free inodes available for all and for non-privileged processes
buf->f_ffree = vd->fs->super->s_free_inodes_count;
// File system id
buf->f_fsid = vd->fs->super->s_magic;
// Bit mask of f_flag values.
buf->f_flag = vd->fs->super->s_flags;
// Maximum length of filenames
buf->f_namemax = EXT2_NAME_LEN;
// Unlock
ext2Unlock(vd);
return 0;
}
/**
* PRIVATE: Callback for directory walking
*/
static int DirIterateCallback(struct ext2_dir_entry *dirent, int offset, int blocksize, char *buf, void *dirState)
{
// Sanity check
if(!dirent)
{
errno = EINVAL;
return -1;
}
ext2_dir_state* dir = STATE(((DIR_ITER *) dirState));
// Sanity check
if (!dir || !dir->vd) {
errno = EINVAL;
return -1;
}
//skip ".." on root directory
if(dir->ni->ino == dir->vd->root && strcmp(dirent->name, "..") == 0)
{
return EXT2_ET_OK;
}
// Allocate a new directory entry
ext2_dir_entry *entry = (ext2_dir_entry *) mem_alloc(sizeof(ext2_dir_entry));
if (!entry)
{
errno = ENOMEM;
return -1;
}
memset(entry, 0, sizeof(ext2_dir_entry));
int stringlen = dirent->name_len & 0xFF;
entry->name = mem_alloc(stringlen+1);
if(!entry->name)
{
mem_free(entry);
errno = ENOMEM;
return -1;
}
// The null termination is not necessarily there in the fs, we gotta do it
int i;
for(i = 0; i < stringlen; ++i)
entry->name[i] = dirent->name[i];
entry->name[i] = '\0';
// Link the entry to the directory
if (!dir->first) {
dir->first = entry;
dir->length = dirent->rec_len;
} else {
ext2_dir_entry *last = dir->first;
while (last->next) last = last->next;
last->next = entry;
}
return EXT2_ET_OK;
}
DIR_ITER *ext2_diropen_r (struct _reent *r, DIR_ITER *dirState, const char *path)
{
ext2_log_trace("dirState %p, path %s\n", dirState, path);
if(!dirState)
{
r->_errno = EINVAL;
return NULL;
}
ext2_dir_state* dir = STATE(dirState);
if(!dir)
{
r->_errno = EINVAL;
return NULL;
}
// Get the volume descriptor for this path
dir->vd = ext2GetVolume(path);
if (!dir->vd) {
r->_errno = ENODEV;
return NULL;
}
// Lock
ext2Lock(dir->vd);
// Find the directory
dir->ni = ext2OpenEntry(dir->vd, path);
if (!dir->ni) {
ext2Unlock(dir->vd);
r->_errno = ENOENT;
return NULL;
}
// Ensure that this directory is indeed a directory
if (!LINUX_S_ISDIR(dir->ni->ni.i_mode)) {
ext2CloseEntry(dir->vd, dir->ni);
ext2Unlock(dir->vd);
r->_errno = ENOTDIR;
return NULL;
}
// Read the directory
dir->first = dir->current = NULL;
if (ext2fs_dir_iterate(dir->vd->fs, dir->ni->ino, 0, 0, DirIterateCallback, dirState) != EXT2_ET_OK) {
ext2CloseDir(dir);
ext2Unlock(dir->vd);
r->_errno = errno;
return NULL;
}
// Move to the first entry in the directory
dir->current = dir->first;
// Update directory times
ext2UpdateTimes(dir->vd, dir->ni, EXT2_UPDATE_ATIME);
// Insert the directory into the double-linked FILO list of open directories
if (dir->vd->firstOpenDir) {
dir->nextOpenDir = dir->vd->firstOpenDir;
dir->vd->firstOpenDir->prevOpenDir = dir;
} else {
dir->nextOpenDir = NULL;
}
dir->prevOpenDir = NULL;
dir->vd->cwd_ni = dir->ni;
dir->vd->firstOpenDir = dir;
dir->vd->openDirCount++;
// Unlock
ext2Unlock(dir->vd);
return dirState;
}
int ext2_dirreset_r (struct _reent *r, DIR_ITER *dirState)
{
ext2_log_trace("dirState %p\n", dirState);
if(!dirState)
{
r->_errno = EINVAL;
return -1;
}
ext2_dir_state* dir = STATE(dirState);
// Sanity check
if (!dir || !dir->vd || !dir->ni) {
r->_errno = EBADF;
return -1;
}
// Lock
ext2Lock(dir->vd);
// Move to the first entry in the directory
dir->current = dir->first;
// Update directory times
ext2UpdateTimes(dir->vd, dir->ni, EXT2_UPDATE_ATIME);
// Unlock
ext2Unlock(dir->vd);
return 0;
}
int ext2_dirnext_r (struct _reent *r, DIR_ITER *dirState, char *filename, struct stat *filestat)
{
ext2_log_trace("dirState %p, filename %p, filestat %p\n", dirState, filename, filestat);
if(!dirState)
{
r->_errno = EINVAL;
return -1;
}
ext2_dir_state* dir = STATE(dirState);
ext2_inode_t *ni = NULL;
// Sanity check
if (!dir || !dir->vd || !dir->ni) {
r->_errno = EBADF;
return -1;
}
// Lock
ext2Lock(dir->vd);
// Check that there is a entry waiting to be fetched
if (!dir->current) {
ext2Unlock(dir->vd);
r->_errno = ENOENT;
return -1;
}
// Fetch the current entry
strcpy(filename, dir->current->name);
if(filestat != NULL)
{
if(strcmp(dir->current->name, ".") == 0 || strcmp(dir->current->name, "..") == 0)
{
memset(filestat, 0, sizeof(struct stat));
filestat->st_mode = S_IFDIR;
}
else
{
ni = ext2OpenEntry(dir->vd, dir->current->name);
if (ni) {
ext2Stat(dir->vd, ni, filestat);
ext2CloseEntry(dir->vd, ni);
}
}
}
// Move to the next entry in the directory
dir->current = dir->current->next;
// Update directory times
ext2UpdateTimes(dir->vd, dir->ni, EXT2_UPDATE_ATIME);
// Unlock
ext2Unlock(dir->vd);
return 0;
}
int ext2_dirclose_r (struct _reent *r, DIR_ITER *dirState)
{
ext2_log_trace("dirState %p\n", dirState);
if(!dirState)
{
r->_errno = EINVAL;
return -1;
}
ext2_dir_state* dir = STATE(dirState);
// Sanity check
if (!dir || !dir->vd) {
r->_errno = EBADF;
return -1;
}
// Lock
ext2Lock(dir->vd);
// Close the directory
ext2CloseDir(dir);
// Remove the directory from the double-linked FILO list of open directories
dir->vd->openDirCount--;
if (dir->nextOpenDir)
dir->nextOpenDir->prevOpenDir = dir->prevOpenDir;
if (dir->prevOpenDir)
dir->prevOpenDir->nextOpenDir = dir->nextOpenDir;
else
dir->vd->firstOpenDir = dir->nextOpenDir;
// Unlock
ext2Unlock(dir->vd);
return 0;
}