Function soclose

freebsd/kern/uipc_socket.c:1177–1253

* Close a socket on last file table reference removal. Initiate disconnect * if connected. Free socket when disconnect complete. * * This function will sorele() the socket. Note that soclose() may be called * prior to the ref count reaching zero. The actual socket structure will * not be freed until the ref count reaches zero. */

 * not be freed until the ref count reaches zero.
 */
int
soclose(struct socket *so)
{
	struct accept_queue lqueue;
	bool listening;
	int error = 0;

	KASSERT(!(so->so_state & SS_NOFDREF), ("soclose: SS_NOFDREF on enter"));

	CURVNET_SET(so->so_vnet);
	funsetown(&so->so_sigio);
	if (so->so_state & SS_ISCONNECTED) {
		if ((so->so_state & SS_ISDISCONNECTING) == 0) {
			error = sodisconnect(so);
			if (error) {
				if (error == ENOTCONN)
					error = 0;
				goto drop;
			}
		}

		if ((so->so_options & SO_LINGER) != 0 && so->so_linger != 0) {
			if ((so->so_state & SS_ISDISCONNECTING) &&
			    (so->so_state & SS_NBIO))
				goto drop;
			while (so->so_state & SS_ISCONNECTED) {
				error = tsleep(&so->so_timeo,
				    PSOCK | PCATCH, "soclos",
				    so->so_linger * hz);
				if (error)
					break;
			}
		}
	}

drop:
	if (so->so_proto->pr_usrreqs->pru_close != NULL)
		(*so->so_proto->pr_usrreqs->pru_close)(so);

	SOCK_LOCK(so);
	if ((listening = (so->so_options & SO_ACCEPTCONN))) {
		struct socket *sp;

		TAILQ_INIT(&lqueue);
		TAILQ_SWAP(&lqueue, &so->sol_incomp, socket, so_list);
		TAILQ_CONCAT(&lqueue, &so->sol_comp, so_list);

		so->sol_qlen = so->sol_incqlen = 0;

		TAILQ_FOREACH(sp, &lqueue, so_list) {
			SOCK_LOCK(sp);
			sp->so_qstate = SQ_NONE;
			sp->so_listen = NULL;
			SOCK_UNLOCK(sp);
			/* Guaranteed not to be the last. */
			refcount_release(&so->so_count);
		}
	}