extern int move_addr_to_user(void *kaddr, int klen, void __user *uaddr, int __user *ulen);
extern int move_addr_to_kernel(void __user *uaddr, int ulen, void *kaddr);
extern int put_cmsg(struct msghdr*, int level, int type, int len, void *data);
extern int move_addr_to_user(void *kaddr, int klen, void __user *uaddr, int __user *ulen);
extern int move_addr_to_kernel(void __user *uaddr, int ulen, void *kaddr);
extern int put_cmsg(struct msghdr*, int level, int type, int len, void *data);