size_t nbd_wr_sync(int fd, void *buffer, size_t size, bool do_read);
int tcp_socket_outgoing(const char *address, uint16_t port);
int tcp_socket_incoming(const char *address, uint16_t port);
size_t nbd_wr_sync(int fd, void *buffer, size_t size, bool do_read);
int tcp_socket_outgoing(const char *address, uint16_t port);
int tcp_socket_incoming(const char *address, uint16_t port);