/*
* Copyright (c) 2008 Jakub Jermar
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/** @addtogroup fs
* @{
*/
/**
* @file fat_ops.c
* @brief Implementation of VFS operations for the FAT file system server.
*/
#include "fat.h"
#include "../../vfs/vfs.h"
#include <libfs.h>
#include <ipc/ipc.h>
#include <async.h>
#include <errno.h>
#include <string.h>
#include <byteorder.h>
#define FAT_NAME_LEN 8
#define FAT_EXT_LEN 3
#define FAT_PAD ' '
#define FAT_DENTRY_UNUSED 0x00
#define FAT_DENTRY_E5_ESC 0x05
#define FAT_DENTRY_DOT 0x2e
#define FAT_DENTRY_ERASED 0xe5
static void dentry_name_canonify(fat_dentry_t *d, char *buf)
{
int i;
for (i = 0; i < FAT_NAME_LEN; i++) {
if (d->name[i] == FAT_PAD) {
buf++;
break;
}
if (d->name[i] == FAT_DENTRY_E5_ESC)
*buf++ = 0xe5;
else
*buf++ = d->name[i];
}
if (d->ext[0] != FAT_PAD)
*buf++ = '.';
for (i = 0; i < FAT_EXT_LEN; i++) {
if (d->ext[i] == FAT_PAD) {
*buf = '\0';
return;
}
if (d->ext[i] == FAT_DENTRY_E5_ESC)
*buf++ = 0xe5;
else
*buf++ = d->ext[i];
}
}
static fat_dentry_t *fat_dentry_get(fat_node_t *dirnode, unsigned idx)
{
return NULL; /* TODO */
}
static void fat_dentry_put(fat_dentry_t *dentry)
{
/* TODO */
}
static void *fat_node_get(dev_handle_t dev_handle, fs_index_t index)
{
return NULL; /* TODO */
}
static void *fat_match(void *prnt, const char *component)
{
fat_node_t *parentp = (fat_node_t *)prnt;
char name[FAT_NAME_LEN + 1 + FAT_EXT_LEN + 1];
unsigned i;
unsigned dentries;
fat_dentry_t *d;
dentries = parentp->size / sizeof(fat_dentry_t);
for (i = 0; i < dentries; i++) {
d = fat_dentry_get(parentp, i);
if (d->attr & FAT_ATTR_VOLLABEL) {
/* volume label entry */
fat_dentry_put(d);
continue;
}
if (d->name[0] == FAT_DENTRY_ERASED) {
/* not-currently-used entry */
fat_dentry_put(d);
continue;
}
if (d->name[0] == FAT_DENTRY_UNUSED) {
/* never used entry */
fat_dentry_put(d);
break;
}
if (d->name[0] == FAT_DENTRY_DOT) {
/*
* Most likely '.' or '..'.
* It cannot occur in a regular file name.
*/
fat_dentry_put(d);
continue;
}
dentry_name_canonify(d, name);
if (strcmp(name
, component
) == 0) { /* hit */
void *node = fat_node_get(parentp->dev_handle,
(fs_index_t)uint16_t_le2host(d->firstc));
fat_dentry_put(d);
return node;
} else {
/* miss */
fat_dentry_put(d);
}
}
return NULL;
}
/** libfs operations */
libfs_ops_t fat_libfs_ops = {
.match = fat_match,
.node_get = fat_node_get,
.create = NULL,
.destroy = NULL,
.link = NULL,
.unlink = NULL,
.index_get = NULL,
.size_get = NULL,
.lnkcnt_get = NULL,
.has_children = NULL,
.root_get = NULL,
.plb_get_char = NULL,
.is_directory = NULL,
.is_file = NULL
};
void fat_lookup(ipc_callid_t rid, ipc_call_t *request)
{
libfs_lookup(&fat_libfs_ops, fat_reg.fs_handle, rid, request);
}
/**
* @}
*/