io_connect
io_connect(conn->iofwd, conn->ai);
int io_connect(struct io *, struct addrinfo *);
int io_connect(struct io *, const struct sockaddr *, const struct sockaddr *);
if (io_connect(s->io, sa, s->route->src->sa) == -1) {
if (io_connect(proto->io, proto->params.dst, proto->params.src) == -1) {