sosplice
struct sosplice ssp;
pool_init(&sosplice_pool, sizeof(struct sosplice), 0, IPL_SOFTNET, 0,
error = sosplice(so, -1, 0, NULL);
error = sosplice(so, *mtod(m, int *), 0, NULL);
error = sosplice(so,
int sosplice(struct socket *, int, off_t, struct timeval *);
struct sosplice *so_sp; /* [s br] */
struct sosplice ssp;