size_t len, int noblock, int flags, int *addr_len);
extern int udp_sendpage(struct sock *sk, struct page *page, int offset,
size_t size, int flags);
size_t len, int noblock, int flags, int *addr_len);
extern int udp_sendpage(struct sock *sk, struct page *page, int offset,
size_t size, int flags);