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;
}
/* 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 int __open_file(struct inode *inode, struct file *file,
struct dentry *parent)
{
struct dentry *lower_dentry;
struct file *lower_file;
struct vfsmount *lower_mnt;
struct dentry *dentry = file->f_path.dentry;
int lower_flags;
int i = 0, idx = 0;
for (i = 0; i <= 1; i++) {
lower_dentry = wrapfs_lower_dentry_idx(dentry, i);
if (!lower_dentry || !lower_dentry->d_inode)
continue;
lower_flags = file->f_flags;
if (lower_dentry->d_inode && (i == 1)) {
UDBG;
if (lower_flags & O_TRUNC) {
int size = 0;
int err = -EROFS;
UDBG;
err = copyup_file(parent->d_inode, file,
i, 0, size);
if (!err)
break;
return err;
} else
lower_flags &= ~(OPEN_WRITE_FLAGS);
}
dget(lower_dentry);
lower_mnt = mntget(wrapfs_lower_mnt_idx(dentry, i));
if (!lower_mnt)
lower_mnt = mntget(wrapfs_lower_mnt_idx(parent, i));
lower_file = dentry_open(lower_dentry, lower_mnt, lower_flags,
current_cred());
if (IS_ERR(lower_file))
return PTR_ERR(lower_file);
wrapfs_set_lower_file(file, lower_file);
branchget(inode->i_sb, i);
idx = i;
goto out;
}
out:
if (!wrapfs_lower_inode_idx(inode, idx))
fsstack_copy_attr_all(inode,
wrapfs_lower_inode_idx(inode, idx));
return 0;
}
/* 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;
}
/* 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 int wrapfs_open(struct inode *inode, struct file *file)
{
int err = 0;
struct file *lower_file = NULL;
struct path lower_path;
#ifdef EXTRA_CREDIT
int CHKSUM_SIZE =0;
char *algo = kmalloc(sizeof(char)*10,GFP_KERNEL);
int *algo_len = kmalloc(sizeof(char)*1,GFP_KERNEL);
char *chkbuf = kmalloc(sizeof(char)*32,GFP_KERNEL);
char *getchkbuf = kmalloc(sizeof(char)*32,GFP_KERNEL);
#else
char *chkbuf = kmalloc(sizeof(char)*CHKSUM_SIZE,GFP_KERNEL);
char *getchkbuf = kmalloc(sizeof(char)*CHKSUM_SIZE,GFP_KERNEL);
#endif
char *has_integrity = kmalloc(sizeof(char)*1,GFP_KERNEL);
int rc = 0;
if(!chkbuf || !has_integrity || !getchkbuf)
{
err = -ENOMEM;
goto out_err;
}
/* 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 {
#ifdef EXTRA_CREDIT
CHKSUM_SIZE = get_default_chksum_size(lower_path.dentry,algo,algo_len);
#endif
rc = vfs_getxattr(lower_path.dentry,XATTR_HAS_INTEGRITY,has_integrity,1);
if(rc > 0 && !S_ISDIR(lower_path.dentry->d_inode->i_mode))
{
wrapfs_set_lower_file(file,lower_file);
if(lower_file->f_mode == O_TRUNC)
wrapfs_set_write_dirty(inode,WRITE_DIRTY_BIT);
if(!memcmp(has_integrity,"1",1) && wrapfs_get_write_dirty(inode)!=WRITE_DIRTY_BIT && rc ==1)
{
if(vfs_getxattr(lower_path.dentry,XATTR_INTEGRITY_VAL,chkbuf,CHKSUM_SIZE)>0)
{
//mutex_lock(&lower_path.dentry->d_inode->i_mutex);
calculate_checksum(lower_file,getchkbuf,CHKSUM_SIZE);
if(memcmp(chkbuf,getchkbuf,CHKSUM_SIZE))
{
printk("Integrity mismatch\n");
err = -EPERM;
wrapfs_set_lower_file(file,NULL);
fput(lower_file);
}
//mutex_unlock(&lower_path.dentry->d_inode->i_mutex);
}
}
else if(!memcmp(has_integrity,"0",1) && rc ==1)
{
if(vfs_getxattr(lower_path.dentry,XATTR_INTEGRITY_VAL,chkbuf,CHKSUM_SIZE)>0)
{
err = -EIO;
wrapfs_set_lower_file(file,NULL);
fput(lower_file);
}
else
wrapfs_set_lower_file(file,lower_file);
}
else
{
printk("File corrupted.Unexpected value for has_integrity attribute\n");
err = -EPERM;
wrapfs_set_lower_file(file,NULL);
fput(lower_file);
}
}
else if(vfs_getxattr(lower_path.dentry,XATTR_HAS_INTEGRITY,has_integrity,1)<=0 && vfs_getxattr(lower_path.dentry,XATTR_INTEGRITY_VAL,chkbuf,CHKSUM_SIZE)>0)
{
err = -EIO;
wrapfs_set_lower_file(file,NULL);
fput(lower_file);
}
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:
kfree(chkbuf);
kfree(getchkbuf);
kfree(has_integrity);
#ifdef EXTRA_CREDIT
kfree(algo);
kfree(algo_len);
#endif
return err;
}
