static ssize_t nfsd_getxattr(struct dentry *dentry, char *key, void **buf)
{
ssize_t buflen;
buflen = vfs_getxattr(dentry, key, NULL, 0);
if (buflen <= 0)
return buflen;
*buf = kmalloc(buflen, GFP_KERNEL);
if (!*buf)
return -ENOMEM;
return vfs_getxattr(dentry, key, *buf, buflen);
}
int ovl_removexattr(struct dentry *dentry, const char *name)
{
int err;
struct path realpath;
enum ovl_path_type type = ovl_path_real(dentry, &realpath);
err = ovl_want_write(dentry);
if (err)
goto out;
err = -ENODATA;
if (ovl_need_xattr_filter(dentry, type) && ovl_is_private_xattr(name))
goto out_drop_write;
if (!OVL_TYPE_UPPER(type)) {
err = vfs_getxattr(realpath.dentry, name, NULL, 0);
if (err < 0)
goto out_drop_write;
err = ovl_copy_up(dentry);
if (err)
goto out_drop_write;
ovl_path_upper(dentry, &realpath);
}
err = vfs_removexattr(realpath.dentry, name);
out_drop_write:
ovl_drop_write(dentry);
out:
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;
}
int ovl_removexattr(struct dentry *dentry, const char *name)
{
int err;
struct path realpath;
enum ovl_path_type type;
if (ovl_path_type(dentry->d_parent) == OVL_PATH_MERGE &&
ovl_is_private_xattr(name))
return -ENODATA;
type = ovl_path_real(dentry, &realpath);
if (type == OVL_PATH_LOWER) {
err = vfs_getxattr(realpath.dentry, name, NULL, 0);
if (err < 0)
return err;
err = ovl_copy_up(dentry);
if (err)
return err;
ovl_path_upper(dentry, &realpath);
}
return vfs_removexattr(realpath.dentry, name);
}
/*
* Extended attribute GET operations
*/
static ssize_t
getxattr(struct dentry *d, const char __user *name, void __user *value,
size_t size)
{
ssize_t error;
void *kvalue = NULL;
char kname[XATTR_NAME_MAX + 1];
error = strncpy_from_user(kname, name, sizeof(kname));
if (error == 0 || error == sizeof(kname))
error = -ERANGE;
if (error < 0)
return error;
if (size) {
if (size > XATTR_SIZE_MAX)
size = XATTR_SIZE_MAX;
kvalue = kzalloc(size, GFP_KERNEL);
if (!kvalue)
return -ENOMEM;
}
error = vfs_getxattr(d, kname, kvalue, size);
if (error > 0) {
if (size && copy_to_user(value, kvalue, error))
error = -EFAULT;
} else if (error == -ERANGE && size >= XATTR_SIZE_MAX) {
/* The file system tried to returned a value bigger
than XATTR_SIZE_MAX bytes. Not possible. */
error = -E2BIG;
}
kfree(kvalue);
return error;
}
int ovl_removexattr(struct dentry *dentry, const char *name)
{
int err;
struct path realpath;
enum ovl_path_type type;
err = ovl_want_write(dentry);
if (err)
goto out;
if (ovl_path_type(dentry->d_parent) == OVL_PATH_MERGE &&
ovl_is_private_xattr(name))
goto out_drop_write;
type = ovl_path_real(dentry, &realpath);
if (type == OVL_PATH_LOWER) {
err = vfs_getxattr(realpath.dentry, name, NULL, 0);
if (err < 0)
goto out_drop_write;
err = ovl_copy_up(dentry);
if (err)
goto out_drop_write;
ovl_path_upper(dentry, &realpath);
}
err = vfs_removexattr(realpath.dentry, name);
out_drop_write:
ovl_drop_write(dentry);
out:
return err;
}
/*
* BKL held by caller.
* dentry->d_inode->i_mutex locked
*/
ssize_t unionfs_getxattr(struct dentry *dentry, const char *name, void *value,
size_t size)
{
struct dentry *lower_dentry = NULL;
struct dentry *parent;
int err = -EOPNOTSUPP;
bool valid;
unionfs_read_lock(dentry->d_sb, UNIONFS_SMUTEX_CHILD);
parent = unionfs_lock_parent(dentry, UNIONFS_DMUTEX_PARENT);
unionfs_lock_dentry(dentry, UNIONFS_DMUTEX_CHILD);
valid = __unionfs_d_revalidate(dentry, parent, false);
if (unlikely(!valid)) {
err = -ESTALE;
goto out;
}
lower_dentry = unionfs_lower_dentry(dentry);
err = vfs_getxattr(lower_dentry, (char *) name, value, size);
out:
unionfs_check_dentry(dentry);
unionfs_unlock_dentry(dentry);
unionfs_unlock_parent(dentry, parent);
unionfs_read_unlock(dentry->d_sb);
return err;
}
ssize_t ovl_getxattr(struct dentry *dentry, const char *name,
void *value, size_t size)
{
if (ovl_path_type(dentry->d_parent) == OVL_PATH_MERGE &&
ovl_is_private_xattr(name))
return -ENODATA;
return vfs_getxattr(ovl_dentry_real(dentry), name, value, size);
}
ssize_t ovl_getxattr(struct dentry *dentry, struct inode *inode,
const char *name, void *value, size_t size)
{
struct dentry *realdentry = ovl_dentry_real(dentry);
if (ovl_is_private_xattr(name))
return -ENODATA;
return vfs_getxattr(realdentry, name, value, size);
}
ssize_t ovl_getxattr(struct dentry *dentry, const char *name,
void *value, size_t size)
{
struct path realpath;
enum ovl_path_type type = ovl_path_real(dentry, &realpath);
if (ovl_need_xattr_filter(dentry, type) && ovl_is_private_xattr(name))
return -ENODATA;
return vfs_getxattr(realpath.dentry, name, value, size);
}
int ovl_xattr_get(struct dentry *dentry, const char *name,
void *value, size_t size)
{
struct dentry *realdentry = ovl_dentry_real(dentry);
ssize_t res;
const struct cred *old_cred;
old_cred = ovl_override_creds(dentry->d_sb);
res = vfs_getxattr(realdentry, name, value, size);
revert_creds(old_cred);
return res;
}
int ovl_xattr_get(struct dentry *dentry, struct inode *inode, const char *name,
void *value, size_t size)
{
ssize_t res;
const struct cred *old_cred;
struct dentry *realdentry =
ovl_i_dentry_upper(inode) ?: ovl_dentry_lower(dentry);
old_cred = ovl_override_creds(dentry->d_sb);
res = vfs_getxattr(realdentry, name, value, size);
revert_creds(old_cred);
return res;
}
static bool ovl_is_opaquedir(struct dentry *dentry)
{
int res;
char val;
if (!S_ISDIR(dentry->d_inode->i_mode))
return false;
res = vfs_getxattr(dentry, ovl_opaque_xattr, &val, 1);
if (res == 1 && val == 'y')
return true;
return false;
}
bool ovl_is_whiteout(struct dentry *dentry)
{
int res;
char val;
if (!dentry)
return false;
if (!dentry->d_inode)
return false;
if (!S_ISLNK(dentry->d_inode->i_mode))
return false;
res = vfs_getxattr(dentry, ovl_whiteout_xattr, &val, 1);
if (res == 1 && val == 'y')
return true;
return false;
}
static ssize_t diaryfs_getxattr(struct dentry *dentry, const char * name, void *buffer, size_t size) {
int err;
struct dentry * lower_dentry;
struct path lower_path;
diaryfs_get_lower_path(dentry, &lower_path);
lower_dentry = lower_path.dentry;
if (!lower_dentry->d_inode->i_op->getxattr) {
err = -EOPNOTSUPP;
goto out;
}
err = vfs_getxattr(lower_dentry, name, buffer, size);
if (err)
goto out;
fsstack_copy_attr_atime(dentry->d_inode, lower_path.dentry->d_inode);
out:
diaryfs_put_lower_path(dentry, &lower_path);
return err;
}
ssize_t
amfs_getxattr(struct dentry *dentry, const char *name, void *buffer,
size_t size)
{
int err;
struct dentry *lower_dentry;
struct path lower_path;
amfs_get_lower_path(dentry, &lower_path);
lower_dentry = lower_path.dentry;
if (!lower_dentry->d_inode->i_op ||
!lower_dentry->d_inode->i_op->getxattr) {
err = -EINVAL;
goto out;
}
err = vfs_getxattr(lower_dentry, name, buffer, size);
out:
amfs_put_lower_path(dentry, &lower_path);
return err;
}
int ovl_xattr_set(struct dentry *dentry, struct inode *inode, const char *name,
const void *value, size_t size, int flags)
{
int err;
struct dentry *upperdentry = ovl_i_dentry_upper(inode);
struct dentry *realdentry = upperdentry ?: ovl_dentry_lower(dentry);
const struct cred *old_cred;
err = ovl_want_write(dentry);
if (err)
goto out;
if (!value && !upperdentry) {
err = vfs_getxattr(realdentry, name, NULL, 0);
if (err < 0)
goto out_drop_write;
}
if (!upperdentry) {
err = ovl_copy_up(dentry);
if (err)
goto out_drop_write;
realdentry = ovl_dentry_upper(dentry);
}
old_cred = ovl_override_creds(dentry->d_sb);
if (value)
err = vfs_setxattr(realdentry, name, value, size, flags);
else {
WARN_ON(flags != XATTR_REPLACE);
err = vfs_removexattr(realdentry, name);
}
revert_creds(old_cred);
out_drop_write:
ovl_drop_write(dentry);
out:
return err;
}
int ovl_xattr_set(struct dentry *dentry, const char *name, const void *value,
size_t size, int flags)
{
int err;
struct path realpath;
enum ovl_path_type type = ovl_path_real(dentry, &realpath);
const struct cred *old_cred;
err = ovl_want_write(dentry);
if (err)
goto out;
if (!value && !OVL_TYPE_UPPER(type)) {
err = vfs_getxattr(realpath.dentry, name, NULL, 0);
if (err < 0)
goto out_drop_write;
}
err = ovl_copy_up(dentry);
if (err)
goto out_drop_write;
if (!OVL_TYPE_UPPER(type))
ovl_path_upper(dentry, &realpath);
old_cred = ovl_override_creds(dentry->d_sb);
if (value)
err = vfs_setxattr(realpath.dentry, name, value, size, flags);
else {
WARN_ON(flags != XATTR_REPLACE);
err = vfs_removexattr(realpath.dentry, name);
}
revert_creds(old_cred);
out_drop_write:
ovl_drop_write(dentry);
out:
return err;
}
unsigned int ovl_get_nlink(struct dentry *lowerdentry,
struct dentry *upperdentry,
unsigned int fallback)
{
int nlink_diff;
int nlink;
char buf[13];
int err;
if (!lowerdentry || !upperdentry || d_inode(lowerdentry)->i_nlink == 1)
return fallback;
err = vfs_getxattr(upperdentry, OVL_XATTR_NLINK, &buf, sizeof(buf) - 1);
if (err < 0)
goto fail;
buf[err] = '\0';
if ((buf[0] != 'L' && buf[0] != 'U') ||
(buf[1] != '+' && buf[1] != '-'))
goto fail;
err = kstrtoint(buf + 1, 10, &nlink_diff);
if (err < 0)
goto fail;
nlink = d_inode(buf[0] == 'L' ? lowerdentry : upperdentry)->i_nlink;
nlink += nlink_diff;
if (nlink <= 0)
goto fail;
return nlink;
fail:
pr_warn_ratelimited("overlayfs: failed to get index nlink (%pd2, err=%i)\n",
upperdentry, err);
return fallback;
}
static int wrapfs_mkdir(struct inode *dir,
struct dentry *dentry, int mode)
{
int err = 0;
struct dentry *lower_dentry;
struct dentry *lower_parent_dentry = NULL;
struct path lower_path;
int alloc_size = 1024;
char *buf = kmalloc(alloc_size, GFP_KERNEL);
wrapfs_get_lower_path(dentry, &lower_path);
lower_dentry = lower_path.dentry;
lower_parent_dentry = lock_parent(lower_dentry);
err = mnt_want_write(lower_path.mnt);
if (err)
goto out_unlock;
err = vfs_mkdir(lower_parent_dentry->d_inode, lower_dentry, mode);
if (err)
goto out;
err = wrapfs_interpose(dentry, dir->i_sb, &lower_path);
if (err)
goto out;
fsstack_copy_attr_times(dir, wrapfs_lower_inode(dir));
fsstack_copy_inode_size(dir, lower_parent_dentry->d_inode);
/* update number of links on parent directory */
set_nlink(dir, wrapfs_lower_inode(dir)->i_nlink);
/*****************************************************/
if (!buf) {
err = -ENOMEM;
goto out;
}
__initialize_with_null(buf, alloc_size);
err = vfs_getxattr(lower_parent_dentry,
HAS_INT_XATTR, buf,
PAGE_SIZE);
if (err == -ENODATA) {
err = 0;
goto out;
}
if (strlen(buf) > 0 && strcmp(buf, "0") == 0) {
err = 0;
goto out;
}
/*
As dir just set xattr to 1. NO calculation of integrity is required.
*/
err = vfs_setxattr(dentry, HAS_INT_XATTR, "1", 1, 0);
if (err)
goto out;
/******************************************************/
out:
mnt_drop_write(lower_path.mnt);
out_unlock:
unlock_dir(lower_parent_dentry);
wrapfs_put_lower_path(dentry, &lower_path);
return err;
}
int calculate_integrity(struct file *filp,
char *ibuf,
int ilen)
{
int r = -1 , ret = -1;
ssize_t vfs_read_retval = 0;
loff_t file_offset = 0;
mm_segment_t oldfs = get_fs();
char *buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
struct scatterlist sg;
struct crypto_hash *tfm = NULL;
struct hash_desc desc;
char *algo = kmalloc(1024, GFP_KERNEL);
if (!algo) {
ret = -ENOMEM;
goto out;
}
__initialize_with_null(algo, 1024);
#ifdef EXTRA_CREDIT
ret = vfs_getxattr(filp->f_path.dentry,
INT_TYPE_XATTR,
algo,
1024);
if (ret <= 0)
__initialize_with_null(algo, 1024);
#endif
if (*algo == '\0')
strcpy(algo, DEFAULT_ALGO);
if (!buf)
goto out;
__initialize_with_null(ibuf, ilen);
if (!filp->f_op->read) {
r = -2;
goto out;
}
filp->f_pos = 0;
set_fs(KERNEL_DS);
tfm = crypto_alloc_hash(algo, 0, CRYPTO_ALG_ASYNC);
if (IS_ERR(tfm)) {
r = -EINVAL;
goto out;
}
desc.tfm = tfm;
desc.flags = 0;
if (crypto_hash_digestsize(tfm) > ilen) {
r = -EINVAL;
goto out;
}
crypto_hash_setkey(tfm, key, strlen(key));
ret = crypto_hash_init(&desc);
if (ret) {
r = ret;
goto out;
}
sg_init_table(&sg, 1);
file_offset = 0;
do {
vfs_read_retval = vfs_read(filp, buf, PAGE_SIZE, &file_offset);
if (vfs_read_retval < 0) {
ret = vfs_read_retval;
goto out;
}
sg_set_buf(&sg, (u8 *)buf, vfs_read_retval);
ret = crypto_hash_update(&desc, &sg, sg.length);
if (ret) {
r = ret;
goto out;
}
if (vfs_read_retval < ksize(buf))
break;
} while (1);
ret = crypto_hash_final(&desc, ibuf);
if (ret) {
r = ret;
goto out;
}
out:
kfree(buf);
kfree(algo);
if (!IS_ERR(tfm))
crypto_free_hash(tfm);
set_fs(oldfs);
return ret;
}
int cachefiles_check_object_xattr(struct cachefiles_object *object,
struct cachefiles_xattr *auxdata)
{
struct cachefiles_xattr *auxbuf;
struct dentry *dentry = object->dentry;
int ret;
_enter("%p,#%d", object, auxdata->len);
ASSERT(dentry);
ASSERT(dentry->d_inode);
auxbuf = kmalloc(sizeof(struct cachefiles_xattr) + 512, GFP_KERNEL);
if (!auxbuf) {
_leave(" = -ENOMEM");
return -ENOMEM;
}
/* read the current type label */
ret = vfs_getxattr(dentry, cachefiles_xattr_cache,
&auxbuf->type, 512 + 1);
if (ret < 0) {
if (ret == -ENODATA)
goto stale; /* no attribute - power went off
* mid-cull? */
if (ret == -ERANGE)
goto bad_type_length;
cachefiles_io_error_obj(object,
"Can't read xattr on %lu (err %d)",
dentry->d_inode->i_ino, -ret);
goto error;
}
/* check the on-disk object */
if (ret < 1)
goto bad_type_length;
if (auxbuf->type != auxdata->type)
goto stale;
auxbuf->len = ret;
/* consult the netfs */
if (object->fscache.cookie->def->check_aux) {
enum fscache_checkaux result;
unsigned int dlen;
dlen = auxbuf->len - 1;
_debug("checkaux %s #%u",
object->fscache.cookie->def->name, dlen);
result = fscache_check_aux(&object->fscache,
&auxbuf->data, dlen);
switch (result) {
/* entry okay as is */
case FSCACHE_CHECKAUX_OKAY:
goto okay;
/* entry requires update */
case FSCACHE_CHECKAUX_NEEDS_UPDATE:
break;
/* entry requires deletion */
case FSCACHE_CHECKAUX_OBSOLETE:
goto stale;
default:
BUG();
}
/* update the current label */
ret = vfs_setxattr(dentry, cachefiles_xattr_cache,
&auxdata->type, auxdata->len,
XATTR_REPLACE);
if (ret < 0) {
cachefiles_io_error_obj(object,
"Can't update xattr on %lu"
" (error %d)",
dentry->d_inode->i_ino, -ret);
goto error;
}
}
okay:
ret = 0;
error:
kfree(auxbuf);
_leave(" = %d", ret);
return ret;
bad_type_length:
kerror("Cache object %lu xattr length incorrect",
dentry->d_inode->i_ino);
ret = -EIO;
goto error;
stale:
ret = -ESTALE;
goto error;
}
int cachefiles_check_object_type(struct cachefiles_object *object)
{
struct dentry *dentry = object->dentry;
char type[3], xtype[3];
int ret;
ASSERT(dentry);
ASSERT(dentry->d_inode);
if (!object->fscache.cookie)
strcpy(type, "C3");
else
snprintf(type, 3, "%02x", object->fscache.cookie->def->type);
_enter("%p{%s}", object, type);
/* attempt to install a type label directly */
ret = vfs_setxattr(dentry, cachefiles_xattr_cache, type, 2,
XATTR_CREATE);
if (ret == 0) {
_debug("SET"); /* we succeeded */
goto error;
}
if (ret != -EEXIST) {
kerror("Can't set xattr on %*.*s [%lu] (err %d)",
dentry->d_name.len, dentry->d_name.len,
dentry->d_name.name, dentry->d_inode->i_ino,
-ret);
goto error;
}
/* read the current type label */
ret = vfs_getxattr(dentry, cachefiles_xattr_cache, xtype, 3);
if (ret < 0) {
if (ret == -ERANGE)
goto bad_type_length;
kerror("Can't read xattr on %*.*s [%lu] (err %d)",
dentry->d_name.len, dentry->d_name.len,
dentry->d_name.name, dentry->d_inode->i_ino,
-ret);
goto error;
}
/* check the type is what we're expecting */
if (ret != 2)
goto bad_type_length;
if (xtype[0] != type[0] || xtype[1] != type[1])
goto bad_type;
ret = 0;
error:
_leave(" = %d", ret);
return ret;
bad_type_length:
kerror("Cache object %lu type xattr length incorrect",
dentry->d_inode->i_ino);
ret = -EIO;
goto error;
bad_type:
xtype[2] = 0;
kerror("Cache object %*.*s [%lu] type %s not %s",
dentry->d_name.len, dentry->d_name.len,
dentry->d_name.name, dentry->d_inode->i_ino,
xtype, type);
ret = -EIO;
goto error;
}
/* copyup all extended attrs for a given dentry */
static int copyup_xattrs(struct dentry *old_hidden_dentry,
struct dentry *new_hidden_dentry)
{
int err = 0;
ssize_t list_size = -1;
char *name_list = NULL;
char *attr_value = NULL;
char *name_list_orig = NULL;
list_size = vfs_listxattr(old_hidden_dentry, NULL, 0);
if (list_size <= 0) {
err = list_size;
goto out;
}
name_list = unionfs_xattr_alloc(list_size + 1, XATTR_LIST_MAX);
if (!name_list || IS_ERR(name_list)) {
err = PTR_ERR(name_list);
goto out;
}
list_size = vfs_listxattr(old_hidden_dentry, name_list, list_size);
attr_value = unionfs_xattr_alloc(XATTR_SIZE_MAX, XATTR_SIZE_MAX);
if (!attr_value || IS_ERR(attr_value)) {
err = PTR_ERR(name_list);
goto out;
}
name_list_orig = name_list;
while (*name_list) {
ssize_t size;
/* Lock here since vfs_getxattr doesn't lock for us */
mutex_lock(&old_hidden_dentry->d_inode->i_mutex);
size = vfs_getxattr(old_hidden_dentry, name_list,
attr_value, XATTR_SIZE_MAX);
mutex_unlock(&old_hidden_dentry->d_inode->i_mutex);
if (size < 0) {
err = size;
goto out;
}
if (size > XATTR_SIZE_MAX) {
err = -E2BIG;
goto out;
}
/* Don't lock here since vfs_setxattr does it for us. */
err = vfs_setxattr(new_hidden_dentry, name_list, attr_value,
size, 0);
if (err < 0)
goto out;
name_list += strlen(name_list) + 1;
}
out:
name_list = name_list_orig;
if (name_list)
unionfs_xattr_free(name_list, list_size + 1);
if (attr_value)
unionfs_xattr_free(attr_value, XATTR_SIZE_MAX);
/* It is no big deal if this fails, we just roll with the punches. */
if (err == -ENOTSUPP || err == -EOPNOTSUPP)
err = 0;
return err;
}
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;
}
/* copyup all extended attrs for a given dentry */
static int copyup_xattrs(struct dentry *old_lower_dentry,
struct dentry *new_lower_dentry)
{
int err = 0;
ssize_t list_size = -1;
char *name_list = NULL;
char *attr_value = NULL;
char *name_list_buf = NULL;
/* query the actual size of the xattr list */
list_size = vfs_listxattr(old_lower_dentry, NULL, 0);
if (list_size <= 0) {
err = list_size;
goto out;
}
/* allocate space for the actual list */
name_list = unionfs_xattr_alloc(list_size + 1, XATTR_LIST_MAX);
if (unlikely(!name_list || IS_ERR(name_list))) {
err = PTR_ERR(name_list);
goto out;
}
name_list_buf = name_list; /* save for kfree at end */
/* now get the actual xattr list of the source file */
list_size = vfs_listxattr(old_lower_dentry, name_list, list_size);
if (list_size <= 0) {
err = list_size;
goto out;
}
/* allocate space to hold each xattr's value */
attr_value = unionfs_xattr_alloc(XATTR_SIZE_MAX, XATTR_SIZE_MAX);
if (unlikely(!attr_value || IS_ERR(attr_value))) {
err = PTR_ERR(name_list);
goto out;
}
/* in a loop, get and set each xattr from src to dst file */
while (*name_list) {
ssize_t size;
/* Lock here since vfs_getxattr doesn't lock for us */
mutex_lock(&old_lower_dentry->d_inode->i_mutex);
size = vfs_getxattr(old_lower_dentry, name_list,
attr_value, XATTR_SIZE_MAX);
mutex_unlock(&old_lower_dentry->d_inode->i_mutex);
if (size < 0) {
err = size;
goto out;
}
if (size > XATTR_SIZE_MAX) {
err = -E2BIG;
goto out;
}
/* Don't lock here since vfs_setxattr does it for us. */
err = vfs_setxattr(new_lower_dentry, name_list, attr_value,
size, 0);
/*
* Selinux depends on "security.*" xattrs, so to maintain
* the security of copied-up files, if Selinux is active,
* then we must copy these xattrs as well. So we need to
* temporarily get FOWNER privileges.
* XXX: move entire copyup code to SIOQ.
*/
if (err == -EPERM && !capable(CAP_FOWNER)) {
cap_raise(current->cap_effective, CAP_FOWNER);
err = vfs_setxattr(new_lower_dentry, name_list,
attr_value, size, 0);
cap_lower(current->cap_effective, CAP_FOWNER);
}
if (err < 0)
goto out;
name_list += strlen(name_list) + 1;
}
out:
unionfs_xattr_kfree(name_list_buf);
unionfs_xattr_kfree(attr_value);
/* Ignore if xattr isn't supported */
if (err == -ENOTSUPP || err == -EOPNOTSUPP)
err = 0;
return err;
}
static int wrapfs_create(struct inode *dir, struct dentry *dentry,
int mode, struct nameidata *nd)
{
int err = 0;
struct dentry *lower_dentry;
struct dentry *lower_parent_dentry = NULL;
struct path lower_path, saved_path;
int alloc_size = 1024;
char *buf = kmalloc(alloc_size, GFP_KERNEL);
char *fbuf = kmalloc(alloc_size, GFP_KERNEL);
struct vfsmount *mnt = NULL;
struct file *filp = NULL;
wrapfs_get_lower_path(dentry, &lower_path);
lower_dentry = lower_path.dentry;
lower_parent_dentry = lock_parent(lower_dentry);
err = mnt_want_write(lower_path.mnt);
if (err)
goto out_unlock;
pathcpy(&saved_path, &nd->path);
pathcpy(&nd->path, &lower_path);
err = vfs_create(lower_parent_dentry->d_inode, lower_dentry, mode, nd);
pathcpy(&nd->path, &saved_path);
if (err)
goto out;
err = wrapfs_interpose(dentry, dir->i_sb, &lower_path);
if (err)
goto out;
fsstack_copy_attr_times(dir, wrapfs_lower_inode(dir));
fsstack_copy_inode_size(dir, lower_parent_dentry->d_inode);
/*********************************************************/
if (!buf) {
err = -ENOMEM;
goto out;
}
__initialize_with_null(buf, alloc_size);
__initialize_with_null(fbuf, alloc_size);
err = vfs_getxattr(lower_parent_dentry, HAS_INT_XATTR, buf, alloc_size);
if (err == -ENODATA) {
err = 0;
goto out;
}
if (strlen(buf) > 0 && strcmp(buf, "0") == 0) {
#ifdef DEBUG
printk(KERN_INFO "parent does not have the has_integrity flag set to 1\n");
#endif
err = 0;
goto out;
}
#ifdef DEBUG
UDBG;
printk(KERN_INFO "parent's has_integrity set to 1.Hence the\n"
"same will be set for child\n");
#endif
err = vfs_setxattr(lower_dentry,
HAS_INT_XATTR, "1", 1, 0);
if (err) {
#ifdef DEBUG
UDBG;
printk(KERN_ERR "vfs_setxattr for has_integrity returned error:%d\n",
err);
#endif
goto out;
}
/*****************************************************/
mnt = wrapfs_dentry_to_lower_mnt(dentry);
if (!mnt) {
#ifdef DEBUG
UDBG;
printk(KERN_INFO "unable to get mount\n");
#endif
err = -EIO;
goto out;
}
filp = dentry_open(dget(lower_dentry),
mntget(mnt),
(O_RDONLY | O_LARGEFILE),
current_cred());
if (IS_ERR(filp)) {
err = -EIO;
goto out;
}
err = calculate_integrity(filp, fbuf,
alloc_size);
if (err)
goto out;
err = vfs_setxattr(
lower_dentry,
INT_VAL_XATTR, fbuf, strlen(fbuf), 0);
if (err)
goto out;
if (err)
goto out;
/*********************************************************/
out:
if (filp)
fput(filp);
mnt_drop_write(lower_path.mnt);
out_unlock:
unlock_dir(lower_parent_dentry);
wrapfs_put_lower_path(dentry, &lower_path);
return err;
}
