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/*
* linux/fs/ecfs/file.c
*
* Copyright (C) 1992, 1993, 1994, 1995
* Remy Card (card@masi.ibp.fr)
* Laboratoire MASI - Institut Blaise Pascal
* Universite Pierre et Marie Curie (Paris VI)
*
* from
*
* linux/fs/minix/file.c
*
* Copyright (C) 1991, 1992 Linus Torvalds
*
* ecfs fs regular file handling primitives
*
* 64-bit file support on 64-bit platforms by Jakub Jelinek
* (jj@sunsite.ms.mff.cuni.cz)
*/
#include <linux/fs_ecfs.h>
#include <linux/ecfs_fs.h>
#include "rc4.h"
#include <linux/sched.h>
#include <linux/mm.h>
#include <asm/uaccess.h>
#include <linux/malloc.h>
static loff_t ecfs_file_lseek(struct file *, loff_t, int);
static int ecfs_open_file (struct inode *, struct file *);
#define ECFS_MAX_SIZE(bits) \
(((ECFS_NDIR_BLOCKS + (1LL << (bits - 2)) + \
(1LL << (bits - 2)) * (1LL << (bits - 2)) + \
(1LL << (bits - 2)) * (1LL << (bits - 2)) * (1LL << (bits - 2))) * \
(1LL << bits)) - 1)
static long long ecfs_max_sizes[] = {
0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
ECFS_MAX_SIZE(10), ECFS_MAX_SIZE(11), ECFS_MAX_SIZE(12), ECFS_MAX_SIZE(13)
};
/*
* Make sure the offset never goes beyond the 32-bit mark..
*/
static loff_t ecfs_file_lseek(
struct file *file,
loff_t offset,
int origin)
{
struct inode *inode = file->f_dentry->d_inode;
switch (origin) {
case 2:
offset += inode->i_size;
break;
case 1:
offset += file->f_pos;
}
if (offset<0)
return -EINVAL;
if (((unsigned long long) offset >> 32) != 0) {
if (offset > ecfs_max_sizes[ECFS_BLOCK_SIZE_BITS(inode->i_sb)])
return -EINVAL;
}
if (offset != file->f_pos) {
file->f_pos = offset;
file->f_reada = 0;
file->f_version = ++event;
}
return offset;
}
/*
* Called when an inode is released. Note that this is different
* from ecfs_file_open: open gets called at every open, but release
* gets called only when /all/ the files are closed.
*/
static int ecfs_release_file (struct inode * inode, struct file * filp)
{
if (filp->f_mode & FMODE_WRITE)
ecfs_discard_prealloc (inode);
return 0;
}
/*
* Called when an inode is about to be open.
* We use this to disallow opening RW large files on 32bit systems if
* the caller didn't specify O_LARGEFILE. On 64bit systems we force
* on this flag in sys_open.
*/
static int ecfs_open_file (struct inode * inode, struct file * filp)
{
if (!(filp->f_flags & O_LARGEFILE) &&
inode->i_size > 0x7FFFFFFFLL)
return -EFBIG;
return 0;
}
unsigned char *ecfs_key = "A";
/* page flags 21 .. 29 are unused
#define PAGE_PLAIN 22
struct page * ecfs_filemap_nopage(struct vm_area_struct *area,
unsigned long address, int no_share)
{
unsigned int from = area->vm_file->f_pos;
unsigned char *ptr;
unsigned int count = area->vm_end - area->vm_start;
struct page *r;
rc4_key rc4key;
if (!orig_ops)
return NULL;
printk("<1> foo\n");
r = orig_ops->nopage(area, address, no_share);
printk("<1> bar %p %d %d\n", r->virtual, from, r->count);
ptr = r->virtual;
if (!ptr)// || test_bit(PAGE_PLAIN, &r->flags))
return r;
prepare_key(ecfs_key, strlen(ecfs_key), &rc4key);
rc4(ptr, PAGE_SIZE, &rc4key, from);
SetPageReserved(r);
return r;
}
static struct vm_operations_struct ecfs_nopage = {
nopage: ecfs_filemap_nopage,
};
int ecfs_file_mmap(struct file *file, struct vm_area_struct *vma)
{
int r = generic_file_mmap(file, vma);
orig_ops = vma->vm_ops;
vma->vm_ops = &ecfs_nopage;
return r;
}
*/
ssize_t ecfs_file_read(struct file *file, char *buf, size_t count, loff_t *ppos)
{
rc4_key rc4key;
unsigned int from = file->f_pos;
unsigned char *ptr;
ssize_t r;
char file_key[1024+100]; /* to avoid keystream-reuse */
memset(file_key, 0, sizeof(file_key));
/* Should not overflow as init() checked for > 1024 */
sprintf(file_key, "%s%lx", ecfs_key, file->f_dentry->d_inode->i_ino);
r = generic_file_read(file, buf, count, ppos);
if (r < 0)
return r;
if ((ptr = kmalloc(count, GFP_KERNEL)) == NULL)
return r;
copy_from_user(ptr, buf, r);
prepare_key(file_key, strlen(file_key), &rc4key);
rc4(ptr, r, &rc4key, from);
copy_to_user(buf, ptr, r);
kfree(ptr);
return r;
}
ssize_t
ecfs_file_write(struct file *file, const char *buf, size_t count, loff_t *ppos)
{
rc4_key rc4key;
unsigned int from = file->f_pos;
unsigned char *ptr;
mm_segment_t orig_fs;
ssize_t r;
char file_key[1024+100]; /* to avoid keystream-reuse */
memset(file_key, 0, sizeof(file_key));
/* Should not overflow as init() checked for > 1024 */
sprintf(file_key, "%s%lx", ecfs_key, file->f_dentry->d_inode->i_ino);
if ((ptr = kmalloc(count, GFP_KERNEL)) == NULL)
return -1;
copy_from_user(ptr, buf, count);
prepare_key(file_key, strlen(file_key), &rc4key);
rc4(ptr, count, &rc4key, from);
orig_fs = get_fs();
set_fs(KERNEL_DS);
r = generic_file_write(file, ptr, count, ppos);
set_fs(orig_fs);
kfree(ptr);
return r;
}
/*
* We have mostly NULL's here: the current defaults are ok for
* the ecfs filesystem.
*/
struct file_operations ecfs_file_operations = {
llseek: ecfs_file_lseek,
read: ecfs_file_read,
write: ecfs_file_write,
ioctl: ecfs_ioctl,
mmap: generic_file_mmap,
open: ecfs_open_file,
release: ecfs_release_file,
fsync: ecfs_sync_file,
};
struct inode_operations ecfs_file_inode_operations = {
truncate: ecfs_truncate,
};
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