int afs_permission(struct inode *inode, int mask)
{
	struct afs_vnode *vnode = AFS_FS_I(inode);
	afs_access_t uninitialized_var(access);
	struct key *key;
	int ret;

	if (mask & MAY_NOT_BLOCK)
		return -ECHILD;

	_enter("{{%x:%u},%lx},%x,",
	       vnode->fid.vid, vnode->fid.vnode, vnode->flags, mask);

	key = afs_request_key(vnode->volume->cell);
	if (IS_ERR(key)) {
		_leave(" = %ld [key]", PTR_ERR(key));
		return PTR_ERR(key);
	}

	
	if (!vnode->cb_promised) {
		_debug("not promised");
		ret = afs_vnode_fetch_status(vnode, NULL, key);
		if (ret < 0)
			goto error;
		_debug("new promise [fl=%lx]", vnode->flags);
	}

	
	ret = afs_check_permit(vnode, key, &access);
	if (ret < 0)
		goto error;

	
	_debug("REQ %x ACC %x on %s",
	       mask, access, S_ISDIR(inode->i_mode) ? "dir" : "file");

	if (S_ISDIR(inode->i_mode)) {
		if (mask & MAY_EXEC) {
			if (!(access & AFS_ACE_LOOKUP))
				goto permission_denied;
		} else if (mask & MAY_READ) {
			if (!(access & AFS_ACE_READ))
				goto permission_denied;
		} else if (mask & MAY_WRITE) {
			if (!(access & (AFS_ACE_DELETE | 
					AFS_ACE_INSERT | 
					AFS_ACE_WRITE))) 
				goto permission_denied;
		} else {
			BUG();
		}
	} else {
		if (!(access & AFS_ACE_LOOKUP))
			goto permission_denied;
		if (mask & (MAY_EXEC | MAY_READ)) {
			if (!(access & AFS_ACE_READ))
				goto permission_denied;
		} else if (mask & MAY_WRITE) {
			if (!(access & AFS_ACE_WRITE))
				goto permission_denied;
		}
	}

	key_put(key);
	ret = generic_permission(inode, mask);
	_leave(" = %d", ret);
	return ret;

permission_denied:
	ret = -EACCES;
error:
	key_put(key);
	_leave(" = %d", ret);
	return ret;
}
예제 #2
0
/*
 * check the permissions on an AFS file
 * - AFS ACLs are attached to directories only, and a file is controlled by its
 *   parent directory's ACL
 */
int afs_permission(struct inode *inode, int mask)
{
	struct afs_vnode *vnode = AFS_FS_I(inode);
	afs_access_t uninitialized_var(access);
	struct key *key;
	int ret;

	_enter("{{%x:%u},%lx},%x,",
	       vnode->fid.vid, vnode->fid.vnode, vnode->flags, mask);

	key = afs_request_key(vnode->volume->cell);
	if (IS_ERR(key)) {
		_leave(" = %ld [key]", PTR_ERR(key));
		return PTR_ERR(key);
	}

	/* if the promise has expired, we need to check the server again */
	if (!vnode->cb_promised) {
		_debug("not promised");
		ret = afs_vnode_fetch_status(vnode, NULL, key);
		if (ret < 0)
			goto error;
		_debug("new promise [fl=%lx]", vnode->flags);
	}

	/* check the permits to see if we've got one yet */
	ret = afs_check_permit(vnode, key, &access);
	if (ret < 0)
		goto error;

	/* interpret the access mask */
	_debug("REQ %x ACC %x on %s",
	       mask, access, S_ISDIR(inode->i_mode) ? "dir" : "file");

	if (S_ISDIR(inode->i_mode)) {
		if (mask & MAY_EXEC) {
			if (!(access & AFS_ACE_LOOKUP))
				goto permission_denied;
		} else if (mask & MAY_READ) {
			if (!(access & AFS_ACE_READ))
				goto permission_denied;
		} else if (mask & MAY_WRITE) {
			if (!(access & (AFS_ACE_DELETE | /* rmdir, unlink, rename from */
					AFS_ACE_INSERT | /* create, mkdir, symlink, rename to */
					AFS_ACE_WRITE))) /* chmod */
				goto permission_denied;
		} else {
			BUG();
		}
	} else {
		if (!(access & AFS_ACE_LOOKUP))
			goto permission_denied;
		if (mask & (MAY_EXEC | MAY_READ)) {
			if (!(access & AFS_ACE_READ))
				goto permission_denied;
		} else if (mask & MAY_WRITE) {
			if (!(access & AFS_ACE_WRITE))
				goto permission_denied;
		}
	}

	key_put(key);
	ret = generic_permission(inode, mask, NULL);
	_leave(" = %d", ret);
	return ret;

permission_denied:
	ret = -EACCES;
error:
	key_put(key);
	_leave(" = %d", ret);
	return ret;
}