/* * Implement receive operations on a socket. * We depend on the way that records are added to the sockbuf * by sbappend*. In particular, each record (mbufs linked through m_next) * must begin with an address if the protocol so specifies, * followed by an optional mbuf or mbufs containing ancillary data, * and then zero or more mbufs of data. * In order to avoid blocking network interrupts for the entire time here, * we splx() while doing the actual copy to user space. * Although the sockbuf is locked, new data may still be appended, * and thus we must maintain consistency of the sockbuf during that time. * * The caller may receive the data as a single mbuf chain by supplying * an mbuf **mp0 for use in returning the chain. The uio is then used * only for the count in uio_resid. */