Function ngs_rcvmsg

freebsd/netgraph/ng_socket.c:890–1000

* Incoming messages get passed up to the control socket. * Unless they are for us specifically (socket_type) */

 * Unless they are for us specifically (socket_type)
 */
static int
ngs_rcvmsg(node_p node, item_p item, hook_p lasthook)
{
	struct ngsock *const priv = NG_NODE_PRIVATE(node);
	struct ngpcb *pcbp;
	struct socket *so;
	struct sockaddr_ng addr;
	struct ng_mesg *msg;
	struct mbuf *m;
	ng_ID_t	retaddr = NGI_RETADDR(item);
	int addrlen;
	int error = 0;

	NGI_GET_MSG(item, msg);
	NG_FREE_ITEM(item);

	/*
	 * Grab priv->mtx here to prevent destroying of control socket
	 * after checking that priv->ctlsock is not NULL.
	 */
	mtx_lock(&priv->mtx);
	pcbp = priv->ctlsock;

	/*
	 * Only allow mesgs to be passed if we have the control socket.
	 * Data sockets can only support the generic messages.
	 */
	if (pcbp == NULL) {
		mtx_unlock(&priv->mtx);
		TRAP_ERROR;
		NG_FREE_MSG(msg);
		return (EINVAL);
	}
	so = pcbp->ng_socket;
	SOCKBUF_LOCK(&so->so_rcv);

	/* As long as the race is handled, priv->mtx may be unlocked now. */
	mtx_unlock(&priv->mtx);

#ifdef TRACE_MESSAGES
	printf("[%x]:---------->[socket]: c=<%d>cmd=%x(%s) f=%x #%d\n",
		retaddr,
		msg->header.typecookie,
		msg->header.cmd,
		msg->header.cmdstr,
		msg->header.flags,
		msg->header.token);
#endif

	if (msg->header.typecookie == NGM_SOCKET_COOKIE) {
		switch (msg->header.cmd) {
		case NGM_SOCK_CMD_NOLINGER:
			priv->flags |= NGS_FLAG_NOLINGER;
			break;
		case NGM_SOCK_CMD_LINGER:
			priv->flags &= ~NGS_FLAG_NOLINGER;
			break;
		default: