Function ngs_rcvdata

freebsd/netgraph/ng_socket.c:1005–1047

* Receive data on a hook */

 * Receive data on a hook
 */
static int
ngs_rcvdata(hook_p hook, item_p item)
{
	struct ngsock *const priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
	struct ngpcb *const pcbp = priv->datasock;
	struct socket *so;
	struct sockaddr_ng *addr;
	char *addrbuf[NG_HOOKSIZ + 4];
	int addrlen;
	struct mbuf *m;

	NGI_GET_M(item, m);
	NG_FREE_ITEM(item);

	/* If there is no data socket, black-hole it. */
	if (pcbp == NULL) {
		NG_FREE_M(m);
		return (0);
	}
	so = pcbp->ng_socket;

	/* Get the return address into a sockaddr. */
	addrlen = strlen(NG_HOOK_NAME(hook));	/* <= NG_HOOKSIZ - 1 */
	addr = (struct sockaddr_ng *) addrbuf;
	addr->sg_len = addrlen + 3;
	addr->sg_family = AF_NETGRAPH;
	bcopy(NG_HOOK_NAME(hook), addr->sg_data, addrlen);
	addr->sg_data[addrlen] = '\0';

	/* Try to tell the socket which hook it came in on. */
	SOCKBUF_LOCK(&so->so_rcv);
	if (sbappendaddr_locked(&so->so_rcv, (struct sockaddr *)addr, m,
	    NULL) == 0) {
		SOCKBUF_UNLOCK(&so->so_rcv);
		m_freem(m);
		TRAP_ERROR;
		return (ENOBUFS);
	}

	/* sorwakeup_locked () releases the lock internally. */
	sorwakeup_locked(so);
	return (0);
}

/*
 * Hook disconnection