static int wrapfs_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
{
int err;
struct file *file, *lower_file;
const struct vm_operations_struct *lower_vm_ops;
struct vm_area_struct lower_vma;
/*printk(KERN_ALERT "In wrapfs_fault()\n"); */
memcpy(&lower_vma, vma, sizeof(struct vm_area_struct));
file = lower_vma.vm_file;
lower_vm_ops = WRAPFS_F(file)->lower_vm_ops;
BUG_ON(!lower_vm_ops);
lower_file = wrapfs_lower_file(file);
/*
* XXX: vm_ops->fault may be called in parallel. Because we have to
* resort to temporarily changing the vma->vm_file to point to the
* lower file, a concurrent invocation of wrapfs_fault could see a
* different value. In this workaround, we keep a different copy of
* the vma structure in our stack, so we never expose a different
* value of the vma->vm_file called to us, even temporarily. A
* better fix would be to change the calling semantics of ->fault to
* take an explicit file pointer.
*/
lower_vma.vm_file = lower_file;
err = lower_vm_ops->fault(&lower_vma, vmf);
return err;
}
static int wrapfs_fsync(struct file *file, loff_t start, loff_t end, int datasync)
{
int err;
struct file *lower_file;
struct path lower_path;
struct dentry *dentry = file->f_path.dentry;
#ifdef EXTRA_CREDIT
if(wrapfs_get_debug(file->f_dentry->d_sb) & DEBUG_FILE)
DEBUG_MESG("Enter");
#endif
err = generic_file_fsync(file, start, end, datasync);
if (err)
goto out;
lower_file = wrapfs_lower_file(file);
wrapfs_get_lower_path(dentry, &lower_path);
err = vfs_fsync_range(lower_file, start, end, datasync);
wrapfs_put_lower_path(dentry, &lower_path);
out:
#ifdef EXTRA_CREDIT
if(wrapfs_get_debug(file->f_dentry->d_sb) & DEBUG_FILE)
DEBUG_RETURN("Exit", err);
#endif
return err;
}
/* release all lower object references & free the file info structure */
static int wrapfs_file_release(struct inode *inode, struct file *file)
{
struct file *lower_file;
#ifdef EXTRA_CREDIT
int CHKSUM_SIZE =0;
char *algo = kmalloc(sizeof(char)*10,GFP_KERNEL);
int *algo_len = kmalloc(sizeof(int)*1,GFP_KERNEL);
char *getchkbuf = kmalloc(sizeof(char)*32,GFP_KERNEL);
#else
char *getchkbuf = kmalloc(sizeof(char)*CHKSUM_SIZE,GFP_KERNEL);
#endif
char *has_integrity = kmalloc(sizeof(char)*1,GFP_KERNEL);
int rc;
lower_file = wrapfs_lower_file(file);
if (lower_file) {
if(lower_file->f_mode == O_RDONLY)
goto out_release;
else if(!S_ISDIR(lower_file->f_path.dentry->d_inode->i_mode)&& wrapfs_get_write_dirty(inode) == WRITE_DIRTY_BIT)
{
#ifdef EXTRA_CREDIT
CHKSUM_SIZE = get_default_chksum_size(lower_file->f_path.dentry,algo,algo_len);
#endif
if(!has_integrity || !getchkbuf)
{
rc = -ENOMEM;
goto out_release;
}
spin_lock(&inode->i_lock);
wrapfs_set_write_dirty(inode,READ_DIRTY_BIT);
spin_unlock(&inode->i_lock);
if(vfs_getxattr(lower_file->f_path.dentry,XATTR_HAS_INTEGRITY,has_integrity,1)>0)
{
if(!memcmp(has_integrity,"1",1))
{
calculate_checksum(lower_file,getchkbuf,CHKSUM_SIZE);
rc = vfs_setxattr(lower_file->f_path.dentry,XATTR_INTEGRITY_VAL,getchkbuf,CHKSUM_SIZE,XATTR_CREATE);
if(rc == -EEXIST)
rc = vfs_setxattr(lower_file->f_path.dentry,XATTR_INTEGRITY_VAL,getchkbuf,CHKSUM_SIZE,XATTR_REPLACE);
}
}
}
out_release:
wrapfs_set_lower_file(file, NULL);
fput(lower_file);
}
kfree(WRAPFS_F(file));
kfree(getchkbuf);
kfree(has_integrity);
#ifdef EXTRA_CREDIT
kfree(algo);
kfree(algo_len);
#endif
return 0;
}
static ssize_t wrapfs_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
int err = 0;
struct file *lower_file;
struct dentry *dentry = file->f_path.dentry;
if(wrapfs_get_debug(file->f_dentry->d_sb) & DEBUG_FILE)
DEBUG_MESG("Enter");
// printk("wrapfs_write: Writing '%s'\n", file->f_dentry->d_iname);
lower_file = wrapfs_lower_file(file);
err = vfs_write(lower_file, buf, count, ppos);
/* update our inode times+sizes upon a successful lower write */
if (err >= 0) {
fsstack_copy_inode_size(dentry->d_inode,
lower_file->f_path.dentry->d_inode);
fsstack_copy_attr_times(dentry->d_inode,
lower_file->f_path.dentry->d_inode);
}
if(wrapfs_get_debug(file->f_dentry->d_sb) & DEBUG_FILE)
DEBUG_RETURN("Exit", err);
return err;
}
static long wrapfs_compat_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
long err = -ENOTTY;
struct file *lower_file;
#ifdef EXTRA_CREDIT
if(wrapfs_get_debug(file->f_dentry->d_sb) & DEBUG_FILE)
DEBUG_MESG("Enter");
#endif
lower_file = wrapfs_lower_file(file);
/* XXX: use vfs_ioctl if/when VFS exports it */
if (!lower_file || !lower_file->f_op)
goto out;
if (lower_file->f_op->compat_ioctl)
err = lower_file->f_op->compat_ioctl(lower_file, cmd, arg);
out:
#ifdef EXTRA_CREDIT
if(wrapfs_get_debug(file->f_dentry->d_sb) & DEBUG_FILE)
DEBUG_RETURN("Exit", err);
#endif
return err;
}
static int wrapfs_flush(struct file *file, fl_owner_t id)
{
int err = 0;
struct file *lower_file = NULL;
lower_file = wrapfs_lower_file(file);
if (lower_file && lower_file->f_op && lower_file->f_op->flush)
err = lower_file->f_op->flush(lower_file, id);
return err;
}
static int wrapfs_fasync(int fd, struct file *file, int flag)
{
int err = 0;
struct file *lower_file = NULL;
lower_file = wrapfs_lower_file(file);
if (lower_file->f_op && lower_file->f_op->fasync)
err = lower_file->f_op->fasync(fd, lower_file, flag);
return err;
}
/* release all lower object references & free the file info structure */
static int wrapfs_file_release(struct inode *inode, struct file *file)
{
struct file *lower_file;
lower_file = wrapfs_lower_file(file);
if (lower_file) {
wrapfs_set_lower_file(file, NULL);
fput(lower_file);
}
kfree(WRAPFS_F(file));
return 0;
}
int wrapfs_read_lower(char *data, loff_t offset, size_t size,
struct inode *wrapfs_inode, struct file *file)
{
struct file *lower_file;
mm_segment_t fs_save;
ssize_t rc;
mode_t previous_mode;
#ifdef WRAPFS_CRYPTO
struct crypto_cipher *tfm;
char *decrypted_page_buffer = NULL; // free this
#endif
lower_file = wrapfs_lower_file(file);
if (!lower_file)
return -EIO;
fs_save = get_fs();
set_fs(get_ds());
previous_mode = lower_file->f_mode;
lower_file->f_mode |= FMODE_READ;
rc = vfs_read(lower_file, data, size, &offset);
lower_file->f_mode = previous_mode;
#ifdef WRAPFS_CRYPTO
decrypted_page_buffer = kmalloc(size, GFP_KERNEL);
if (decrypted_page_buffer == NULL)
goto out;
memset(decrypted_page_buffer, 0, size);
tfm = crypto_alloc_cipher("aes", 0, 16);
if (!IS_ERR(tfm))
crypto_cipher_setkey(tfm, WRAPFS_SB(file->f_dentry->d_sb)->key, 16);
else
goto fail;
crypto_cipher_decrypt_one(tfm, decrypted_page_buffer, data);
/*printk(KERN_ALERT "Decrypted buffer = %s\n", decrypted_page_buffer);*/
memcpy(data, decrypted_page_buffer, size);
#endif
set_fs(fs_save);
#ifdef WRAPFS_CRYPTO
crypto_free_cipher(tfm);
fail:
kfree(decrypted_page_buffer);
out:
#endif
return rc;
}
static int wrapfs_open(struct inode *inode, struct file *file)
{
int err = 0;
struct file *lower_file = NULL;
struct path lower_path;
#ifdef EXTRA_CREDIT
if(wrapfs_get_debug(file->f_dentry->d_sb) & DEBUG_FILE)
DEBUG_MESG("Enter");
#endif
/* don't open unhashed/deleted files */
if (d_unhashed(file->f_path.dentry)) {
err = -ENOENT;
goto out_err;
}
file->private_data = kzalloc(sizeof(struct wrapfs_file_info), GFP_KERNEL);
if (!WRAPFS_F(file)) {
err = -ENOMEM;
goto out_err;
}
/* open lower object and link wrapfs's file struct to lower's */
wrapfs_get_lower_path(file->f_path.dentry, &lower_path);
lower_file = dentry_open(lower_path.dentry, lower_path.mnt,
file->f_flags, current_cred());
if (IS_ERR(lower_file)) {
err = PTR_ERR(lower_file);
lower_file = wrapfs_lower_file(file);
if (lower_file) {
wrapfs_set_lower_file(file, NULL);
fput(lower_file); /* fput calls dput for lower_dentry */
}
} else {
wrapfs_set_lower_file(file, lower_file);
}
if (err)
kfree(WRAPFS_F(file));
else
fsstack_copy_attr_all(inode, wrapfs_lower_inode(inode));
out_err:
#ifdef EXTRA_CREDIT
if(wrapfs_get_debug(file->f_dentry->d_sb) & DEBUG_FILE)
DEBUG_RETURN("Exit", err);
#endif
return err;
}
static int wrapfs_readdir(struct file *file, void *dirent, filldir_t filldir)
{
int err = 0;
struct file *lower_file = NULL;
struct dentry *dentry = file->f_path.dentry;
lower_file = wrapfs_lower_file(file);
err = vfs_readdir(lower_file, filldir, dirent);
file->f_pos = lower_file->f_pos;
if (err >= 0) /* copy the atime */
fsstack_copy_attr_atime(dentry->d_inode,
lower_file->f_path.dentry->d_inode);
return err;
}
static int wrapfs_readdir(struct file *file, void *dirent, filldir_t filldir)
{
int err = 0;
struct file *lower_file = NULL;
struct dentry *wrapfs_dentry = file->f_path.dentry;
#ifdef EXTRA_CREDIT
struct wrapfs_getdents_callback buf;
if(wrapfs_get_debug(file->f_dentry->d_sb) & DEBUG_FILE)
DEBUG_MESG("Enter");
#endif
lower_file = wrapfs_lower_file(file);
// lower_file->f_pos = file->f_pos;
#ifdef EXTRA_CREDIT
if(wrapfs_get_debug(file->f_dentry->d_sb) & DEBUG_OTHER)
DEBUG_MESG("Encrypting and Decrypting filenames");
memset(&buf, 0, sizeof(buf));
buf.dirent = dirent;
buf.dentry = wrapfs_dentry;
buf.filldir = filldir;
buf.filldir_called = 0;
buf.entries_written = 0;
err = vfs_readdir(lower_file, wrapfs_filldir, (void *)&buf);
if(err<0)
goto out;
if(buf.filldir_called && !buf.entries_written) {
printk(KERN_ERR "wrapfs_readdir: filldir called but entries not written\n");
goto out;
}
#else
err = vfs_readdir(lower_file, filldir, dirent);
#endif
file->f_pos = lower_file->f_pos;
if (err >= 0) /* copy the atime */
fsstack_copy_attr_atime(wrapfs_dentry->d_inode, lower_file->f_path.dentry->d_inode);
#ifdef EXTRA_CREDIT
if(wrapfs_get_debug(file->f_dentry->d_sb) & DEBUG_FILE)
DEBUG_RETURN("Exit", err);
out:
#endif
return err;
}
static ssize_t wrapfs_read(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
int err;
struct file *lower_file;
struct dentry *dentry = file->f_path.dentry;
lower_file = wrapfs_lower_file(file);
err = vfs_read(lower_file, buf, count, ppos);
/* update our inode atime upon a successful lower read */
if (err >= 0)
fsstack_copy_attr_atime(dentry->d_inode,
lower_file->f_path.dentry->d_inode);
return err;
}
static ssize_t wrapfs_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
int err = 0;
struct file *lower_file;
struct dentry *dentry = file->f_path.dentry;
loff_t pos,lpos;
#ifdef WRAPFS_CRYPTO
char nokey[KEY_LENGTH] = {0,};
#endif
lower_file = wrapfs_lower_file(file);
#ifdef DEBUG_SUPPORT
if(debug_support(lower_file->f_dentry->d_sb,"file"))
UDBG;
#endif
lpos = lower_file->f_pos;
pos = file->f_pos;
if(WRAPFS_SB(lower_file->f_path.dentry->d_sb)->mount_options.mmap == 1)
{
#ifdef WRAPFS_CRYPTO
if(!strcmp(WRAPFS_SB(lower_file->f_dentry->d_sb)->key,nokey)|| no_key_func(WRAPFS_SB(lower_file->f_dentry->d_sb)->key))
{
printk("No key is entered. Encryption operations cannot be done\n");
return -ENOKEY;
}
#endif
err = do_sync_write(file, buf, count, ppos);
}
else
{
err = vfs_write(lower_file, buf, count, ppos);
}
/* update our inode times+sizes upon a successful lower write */
if (err >= 0) {
fsstack_copy_inode_size(dentry->d_inode,
lower_file->f_path.dentry->d_inode);
fsstack_copy_attr_times(dentry->d_inode,
lower_file->f_path.dentry->d_inode);
}
//dump_stack();
#ifdef DEBUG_SUPPORT
if(debug_support(lower_file->f_dentry->d_sb,"file"))
UDBGE(err);
#endif
return err;
}
static long wrapfs_compat_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
long err = -ENOTTY;
struct file *lower_file;
lower_file = wrapfs_lower_file(file);
/* XXX: use vfs_ioctl if/when VFS exports it */
if (!lower_file || !lower_file->f_op)
goto out;
if (lower_file->f_op->compat_ioctl)
err = lower_file->f_op->compat_ioctl(lower_file, cmd, arg);
out:
return err;
}
static long wrapfs_unlocked_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
long err = -ENOTTY;
struct file *lower_file;
#ifdef WRAPFS_CRYPTO
char zero_key[KEYLEN + 1];
char *key = NULL;
memset(zero_key, '0', sizeof(zero_key));
zero_key[KEYLEN] = '\0';
key = kmalloc(KEYLEN + 1, GFP_KERNEL);
if (!key) {
err = -ENOMEM;
goto out;
}
if(copy_from_user(key, (char *) arg, KEYLEN))
goto key_fail;
key[KEYLEN] = '\0';
/*printk(KERN_ALERT "strlen(key) = %d, memcmp(zero_key, key) = %d\n", strlen(key), memcmp(zero_key, key, strlen(key)));*/
if (0 == memcmp(zero_key, key, strlen(key)))
memcpy(WRAPFS_SB(file->f_dentry->d_sb)->key, zero_key, sizeof(zero_key) - 1);
else
memcpy(WRAPFS_SB(file->f_dentry->d_sb)->key, key, strlen(key));
/*printk(KERN_ALERT "key from super block = %s\n", WRAPFS_SB(file->f_dentry->d_sb)->key);*/
#endif
lower_file = wrapfs_lower_file(file);
/* XXX: use vfs_ioctl if/when VFS exports it */
if (!lower_file || !lower_file->f_op)
goto out;
if (lower_file->f_op->unlocked_ioctl)
err = lower_file->f_op->unlocked_ioctl(lower_file, cmd, arg);
#ifdef WRAPFS_CRYPTO
key_fail:
kfree(key);
#endif
out:
return err;
}
static int wrapfs_fsync(struct file *file, loff_t start, loff_t end,
int datasync)
{
int err;
struct file *lower_file;
struct path lower_path;
struct dentry *dentry = file->f_path.dentry;
err = generic_file_fsync(file, start, end, datasync);
if (err)
goto out;
lower_file = wrapfs_lower_file(file);
wrapfs_get_lower_path(dentry, &lower_path);
err = vfs_fsync_range(lower_file, start, end, datasync);
wrapfs_put_lower_path(dentry, &lower_path);
out:
return err;
}
static int wrapfs_flush(struct file *file, fl_owner_t id)
{
int err = 0;
struct file *lower_file = NULL;
lower_file = wrapfs_lower_file(file);
#ifdef DEBUG_SUPPORT
if(debug_support(lower_file->f_dentry->d_sb,"file"))
UDBG;
#endif
if (lower_file && lower_file->f_op && lower_file->f_op->flush)
err = lower_file->f_op->flush(lower_file, id);
#ifdef DEBUG_SUPPORT
if(debug_support(lower_file->f_dentry->d_sb,"file"))
UDBGE(err);
#endif
return err;
}
int wrapfs_write_lower(struct inode *wrapfs_inode, char *data,
loff_t offset, size_t size, struct file *file)
{
struct file *lower_file;
mm_segment_t fs_save;
ssize_t rc;
lower_file = wrapfs_lower_file(file);
if (!lower_file)
return -EIO;
fs_save = get_fs();
set_fs(get_ds());
rc = vfs_write(lower_file, data, size, &offset);
set_fs(fs_save);
mark_inode_dirty_sync(wrapfs_inode);
return rc;
}
static ssize_t wrapfs_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
int err = 0;
struct file *lower_file;
struct dentry *dentry = file->f_path.dentry;
lower_file = wrapfs_lower_file(file);
err = vfs_write(lower_file, buf, count, ppos);
/* update our inode times+sizes upon a successful lower write */
if (err >= 0) {
fsstack_copy_inode_size(dentry->d_inode,
lower_file->f_path.dentry->d_inode);
fsstack_copy_attr_times(dentry->d_inode,
lower_file->f_path.dentry->d_inode);
}
return err;
}
static int wrapfs_flush(struct file *file, fl_owner_t id)
{
int err = 0;
struct file *lower_file = NULL;
#ifdef EXTRA_CREDIT
if(wrapfs_get_debug(file->f_dentry->d_sb) & DEBUG_FILE)
DEBUG_MESG("Enter");
#endif
lower_file = wrapfs_lower_file(file);
if (lower_file && lower_file->f_op && lower_file->f_op->flush)
err = lower_file->f_op->flush(lower_file, id);
#ifdef EXTRA_CREDIT
if(wrapfs_get_debug(file->f_dentry->d_sb) & DEBUG_FILE)
DEBUG_RETURN("Exit", err);
#endif
return err;
}
static int wrapfs_fasync(int fd, struct file *file, int flag)
{
int err = 0;
struct file *lower_file = NULL;
#ifdef EXTRA_CREDIT
if(wrapfs_get_debug(file->f_dentry->d_sb) & DEBUG_FILE)
DEBUG_MESG("Enter");
#endif
lower_file = wrapfs_lower_file(file);
if (lower_file->f_op && lower_file->f_op->fasync)
err = lower_file->f_op->fasync(fd, lower_file, flag);
#ifdef EXTRA_CREDIT
if(wrapfs_get_debug(file->f_dentry->d_sb) & DEBUG_FILE)
DEBUG_RETURN("Exit", err);
#endif
return err;
}
static int wrapfs_readdir(struct file *file, void *dirent, filldir_t filldir)
{
int err = 0;
struct file *lower_file = NULL;
struct dentry *dentry = file->f_path.dentry;
lower_file = wrapfs_lower_file(file);
#ifdef DEBUG_SUPPORT
if(debug_support(lower_file->f_dentry->d_sb,"file"))
UDBG;
#endif
err = vfs_readdir(lower_file, filldir, dirent);
file->f_pos = lower_file->f_pos;
if (err >= 0) /* copy the atime */
fsstack_copy_attr_atime(dentry->d_inode,
lower_file->f_path.dentry->d_inode);
#ifdef DEBUG_SUPPORT
if(debug_support(lower_file->f_dentry->d_sb,"file"))
UDBGE(err);
#endif
return err;
}
static ssize_t wrapfs_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
int err = 0;
struct file *lower_file;
struct dentry *dentry = file->f_path.dentry;
#ifdef WRAPFS_CRYPTO
char zero_key[KEYLEN + 1];
memset(zero_key, '0', sizeof(zero_key));
zero_key[KEYLEN] = '\0';
#endif
/*printk(KERN_ALERT "In wrapfs_write()\n");*/
lower_file = wrapfs_lower_file(file);
if (1 == WRAPFS_SB(file->f_dentry->d_sb)->mount_options.mmap) {
#ifdef WRAPFS_CRYPTO
if (0 == memcmp(&(WRAPFS_SB(file->f_dentry->d_sb)->key), &zero_key, KEYLEN))
return -ENOKEY;
#endif
err = do_sync_write(file, buf, count, ppos);
}
else
{
/*printk(KERN_ALERT "calling vfs_read()\n");*/
err = vfs_write(lower_file, buf, count, ppos);
}
/* update our inode times+sizes upon a successful lower write */
if (err >= 0) {
fsstack_copy_inode_size(dentry->d_inode,
lower_file->f_path.dentry->d_inode);
fsstack_copy_attr_times(dentry->d_inode,
lower_file->f_path.dentry->d_inode);
}
return err;
}
static ssize_t wrapfs_read(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
int err;
struct file *lower_file;
struct dentry *dentry = file->f_path.dentry;
if(wrapfs_get_debug(file->f_dentry->d_sb) & DEBUG_FILE)
DEBUG_MESG("Enter");
// printk("wrapfs_read: Read '%s' using vfs_read\n", file->f_dentry->d_iname);
lower_file = wrapfs_lower_file(file);
err = vfs_read(lower_file, buf, count, ppos);
/* update our inode atime upon a successful lower read */
if (err >= 0)
fsstack_copy_attr_atime(dentry->d_inode, lower_file->f_path.dentry->d_inode);
if(wrapfs_get_debug(file->f_dentry->d_sb) & DEBUG_FILE)
DEBUG_RETURN("Exit", err);
return err;
}
/* release all lower object references & free the file info structure */
static int wrapfs_file_release(struct inode *inode, struct file *file)
{
struct file *lower_file;
#ifdef EXTRA_CREDIT
if(wrapfs_get_debug(file->f_dentry->d_sb) & DEBUG_FILE)
DEBUG_MESG("Enter");
#endif
lower_file = wrapfs_lower_file(file);
if (lower_file) {
wrapfs_set_lower_file(file, NULL);
fput(lower_file);
}
#ifdef EXTRA_CREDIT
if(wrapfs_get_debug(file->f_dentry->d_sb) & DEBUG_FILE)
DEBUG_MESG("Exit");
#endif
kfree(WRAPFS_F(file));
return 0;
}
static ssize_t wrapfs_read(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
int err;
struct file *lower_file;
struct dentry *dentry = file->f_path.dentry;
#ifdef WRAPFS_CRYPTO
char nokey[KEY_LENGTH]={0,};
#endif
lower_file = wrapfs_lower_file(file);
#ifdef DEBUG_SUPPORT
if(debug_support(lower_file->f_dentry->d_sb,"file"))
UDBG;
#endif
if(WRAPFS_SB(lower_file->f_path.dentry->d_sb)->mount_options.mmap == 1)
{
#ifdef WRAPFS_CRYPTO
if(!strcmp(WRAPFS_SB(lower_file->f_dentry->d_sb)->key,nokey) || no_key_func(WRAPFS_SB(lower_file->f_dentry->d_sb)->key))
{
printk("No Key entered. Encrypt operations cannot be done\n");
return -ENOKEY;
}
#endif
err = do_sync_read(file, buf, count, ppos);
}
else
err = vfs_read(lower_file, buf, count, ppos);
/* update our inode atime upon a successful lower read */
if (err >= 0)
fsstack_copy_attr_atime(dentry->d_inode,
lower_file->f_path.dentry->d_inode);
#ifdef DEBUG_SUPPORT
if(debug_support(lower_file->f_dentry->d_sb,"file"))
UDBGE(err);
#endif
return err;
}
static int wrapfs_mmap(struct file *file, struct vm_area_struct *vma)
{
int err = 0;
bool willwrite;
struct file *lower_file;
const struct vm_operations_struct *saved_vm_ops = NULL;
#ifdef DEBUG_SUPPORT
if(debug_support(wrapfs_lower_file(file)->f_dentry->d_sb,"file"))
UDBG;
#endif
/* this might be deferred to mmap's writepage */
willwrite = ((vma->vm_flags | VM_SHARED | VM_WRITE) == vma->vm_flags);
/*
* File systems which do not implement ->writepage may use
* generic_file_readonly_mmap as their ->mmap op. If you call
* generic_file_readonly_mmap with VM_WRITE, you'd get an -EINVAL.
* But we cannot call the lower ->mmap op, so we can't tell that
* writeable mappings won't work. Therefore, our only choice is to
* check if the lower file system supports the ->writepage, and if
* not, return EINVAL (the same error that
* generic_file_readonly_mmap returns in that case).
*/
lower_file = wrapfs_lower_file(file);
if (willwrite && !lower_file->f_mapping->a_ops->writepage) {
err = -EINVAL;
printk(KERN_ERR "wrapfs: lower file system does not "
"support writeable mmap\n");
goto out;
}
/*
* find and save lower vm_ops.
*
* XXX: the VFS should have a cleaner way of finding the lower vm_ops
*/
if (!WRAPFS_F(file)->lower_vm_ops) {
err = lower_file->f_op->mmap(lower_file, vma);
if (err) {
printk(KERN_ERR "wrapfs: lower mmap failed %d\n", err);
goto out;
}
saved_vm_ops = vma->vm_ops; /* save: came from lower ->mmap */
err = do_munmap(current->mm, vma->vm_start,
vma->vm_end - vma->vm_start);
if (err) {
printk(KERN_ERR "wrapfs: do_munmap failed %d\n", err);
goto out;
}
}
/*
* Next 3 lines are all I need from generic_file_mmap. I definitely
* don't want its test for ->readpage which returns -ENOEXEC.
*/
file_accessed(file);
vma->vm_ops = &wrapfs_vm_ops;
vma->vm_flags |= VM_CAN_NONLINEAR;
file->f_mapping->a_ops = &wrapfs_aops; /* set our aops */
if (!WRAPFS_F(file)->lower_vm_ops) /* save for our ->fault */
WRAPFS_F(file)->lower_vm_ops = saved_vm_ops;
out:
#ifdef DEBUG_SUPPORT
if(debug_support(lower_file->f_dentry->d_sb,"file"))
UDBGE(err);
#endif
return err;
}
static long wrapfs_unlocked_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
long err = -ENOTTY;
struct file *lower_file;
#ifdef WRAPFS_CRYPTO
char *key = kmalloc(KEY_LENGTH+1,GFP_KERNEL);
char nokey[KEY_LENGTH]={0,};
long rc = 0;
//char hex[CHKSUM_SIZE*2 + 1];
#endif
lower_file = wrapfs_lower_file(file);
#ifdef DEBUG_SUPPORT
if(debug_support(lower_file->f_dentry->d_sb,"file"))
UDBG;
#endif
/* XXX: use vfs_ioctl if/when VFS exports it */
#ifdef WRAPFS_CRYPTO
if(cmd == IOCTL_KEY)
{
if(key == NULL)
{
err = -ENOMEM;
goto end;
}
if(copy_from_user(key,(char*)arg,KEY_LENGTH))
{
err = -EFAULT;
goto end;
}
if(key == NULL)
{
printk("No key is entered. No encryption will be done\n");
goto end;
}
key[strlen((char*)arg)] ='\0';
if(no_key_func(key))
{
printk("All Zeros are not allowed\n");
rc = -EPERM;
goto end;
}
if(WRAPFS_SB(lower_file->f_dentry->d_sb)->mount_options.mmap == 1 && strcmp(WRAPFS_SB(lower_file->f_dentry->d_sb)->key,nokey))
{
printk("Only one key per instance of mount\n");
rc = -EPERM;
goto end;
}
strcpy(WRAPFS_SB(lower_file->f_dentry->d_sb)->key, key);
//if(calculate_key(key,WRAPFS_SB(lower_file->f_dentry->d_sb)->key,CHKSUM_SIZE))
// goto out;
//for(t=0;t<CHKSUM_SIZE;t++)
// sprintf(&hex[t*2],"%.2x",(unsigned char)WRAPFS_SB(lower_file->f_dentry->d_sb)->key[t]);
//strcpy(WRAPFS_SB(lower_file->f_dentry->d_sb)->key,hex);
}
end:
#endif
if (!lower_file || !lower_file->f_op)
goto out;
if (lower_file->f_op->unlocked_ioctl)
err = lower_file->f_op->unlocked_ioctl(lower_file, cmd, arg);
out:
#ifdef WRAPFS_CRYPTO
if(rc == -EPERM)
err =rc;
if(key!=NULL)
kfree(key);
#endif
#ifdef DEBUG_SUPPORT
if(debug_support(lower_file->f_dentry->d_sb,"file"))
UDBGE((int)err);
#endif
return err;
}
static int wrapfs_setattr(struct dentry *dentry, struct iattr *ia)
{
int err = 0;
struct dentry *lower_dentry;
struct inode *inode;
struct inode *lower_inode;
struct path lower_path;
struct iattr lower_ia;
inode = dentry->d_inode;
/*
* Check if user has permission to change inode. We don't check if
* this user can change the lower inode: that should happen when
* calling notify_change on the lower inode.
*/
err = inode_change_ok(inode, ia);
if (err)
goto out_err;
wrapfs_get_lower_path(dentry, &lower_path);
lower_dentry = lower_path.dentry;
lower_inode = wrapfs_lower_inode(inode);
/* prepare our own lower struct iattr (with the lower file) */
memcpy(&lower_ia, ia, sizeof(lower_ia));
if (ia->ia_valid & ATTR_FILE)
lower_ia.ia_file = wrapfs_lower_file(ia->ia_file);
/*
* If shrinking, first truncate upper level to cancel writing dirty
* pages beyond the new eof; and also if its' maxbytes is more
* limiting (fail with -EFBIG before making any change to the lower
* level). There is no need to vmtruncate the upper level
* afterwards in the other cases: we fsstack_copy_inode_size from
* the lower level.
*/
if (ia->ia_valid & ATTR_SIZE) {
err = inode_newsize_ok(inode, ia->ia_size);
if (err)
goto out;
truncate_setsize(inode, ia->ia_size);
}
/*
* mode change is for clearing setuid/setgid bits. Allow lower fs
* to interpret this in its own way.
*/
if (lower_ia.ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
lower_ia.ia_valid &= ~ATTR_MODE;
/* notify the (possibly copied-up) lower inode */
/*
* Note: we use lower_dentry->d_inode, because lower_inode may be
* unlinked (no inode->i_sb and i_ino==0. This happens if someone
* tries to open(), unlink(), then ftruncate() a file.
*/
mutex_lock(&lower_dentry->d_inode->i_mutex);
err = notify_change(lower_dentry, &lower_ia); /* note: lower_ia */
mutex_unlock(&lower_dentry->d_inode->i_mutex);
if (err)
goto out;
/* get attributes from the lower inode */
fsstack_copy_attr_all(inode, lower_inode);
/*
* Not running fsstack_copy_inode_size(inode, lower_inode), because
* VFS should update our inode size, and notify_change on
* lower_inode should update its size.
*/
out:
wrapfs_put_lower_path(dentry, &lower_path);
out_err:
return err;
}
