MINOR: mux_pt: implement remaining mux_ops methods

This is a basic pass-through implementation which is now basic but
complete and operational, just not used yet.
diff --git a/src/mux_pt.c b/src/mux_pt.c
index 64aae14..48a676f 100644
--- a/src/mux_pt.c
+++ b/src/mux_pt.c
@@ -35,6 +35,26 @@
 	return conn->data->wake ? conn->data->wake(conn) : 0;
 }
 
+/* callback used to update the mux's polling flags after changing a cs' status.
+ * The caller (cs_mux_update_poll) will take care of propagating any changes to
+ * the transport layer.
+ */
+static void mux_pt_update_poll(struct conn_stream *cs)
+{
+	struct connection *conn = cs->conn;
+	int flags = 0;
+
+	conn_refresh_polling_flags(conn);
+
+	if (cs->flags & CS_FL_DATA_RD_ENA)
+		flags |= CO_FL_XPRT_RD_ENA;
+	if (cs->flags & CS_FL_DATA_WR_ENA)
+		flags |= CO_FL_XPRT_WR_ENA;
+
+	conn->flags = (conn->flags & ~(CO_FL_XPRT_RD_ENA | CO_FL_XPRT_WR_ENA)) | flags;
+	conn_cond_update_xprt_polling(conn);
+}
+
 /* callback to be used by default for the pass-through mux. It simply calls the
  * data layer recv() callback much must be set.
  */
@@ -51,12 +71,87 @@
 	conn->data->send(conn);
 }
 
+/*
+ * Attach a new stream to a connection
+ * (Used for outgoing connections)
+ */
+static struct conn_stream *mux_pt_attach(struct connection *conn)
+{
+	return NULL;
+}
+
+/*
+ * Detach the stream from the connection
+ * (Used for outgoing connections)
+ */
+static void mux_pt_detach(struct conn_stream *cs)
+{
+}
+
+static void mux_pt_shutr(struct conn_stream *cs, int clean)
+{
+	if (conn_xprt_ready(cs->conn) && cs->conn->xprt->shutr)
+		cs->conn->xprt->shutr(cs->conn, clean);
+}
+
+static void mux_pt_shutw(struct conn_stream *cs, int clean)
+{
+	if (conn_xprt_ready(cs->conn) && cs->conn->xprt->shutw)
+		cs->conn->xprt->shutw(cs->conn, clean);
+}
+
+/*
+ * Called from the upper layer, to get more data
+ */
+static int mux_pt_rcv_buf(struct conn_stream *cs, struct buffer *buf, int count)
+{
+	int ret;
+
+	ret = cs->conn->xprt->rcv_buf(cs->conn, buf, count);
+	if (conn_xprt_read0_pending(cs->conn))
+		cs->flags |= CS_FL_EOS;
+	return (ret);
+}
+
+/* Called from the upper layer, to send data */
+static int mux_pt_snd_buf(struct conn_stream *cs, struct buffer *buf, int flags)
+{
+	return (cs->conn->xprt->snd_buf(cs->conn, buf, flags));
+}
+
+/* Send and get, using splicing */
+static int mux_pt_rcv_pipe(struct conn_stream *cs, struct pipe *pipe, unsigned int count)
+{
+	int ret;
+
+	ret = cs->conn->xprt->rcv_pipe(cs->conn, pipe, count);
+	if (conn_xprt_read0_pending(cs->conn))
+		cs->flags |= CS_FL_EOS;
+	return (ret);
+}
+
+static int mux_pt_snd_pipe(struct conn_stream *cs, struct pipe *pipe)
+{
+	return (cs->conn->xprt->snd_pipe(cs->conn, pipe));
+}
+
 /* The mux operations */
 const struct mux_ops mux_pt_ops = {
 	.init = mux_pt_init,
 	.recv = mux_pt_recv,
 	.send = mux_pt_send,
 	.wake = mux_pt_wake,
+	.update_poll = mux_pt_update_poll,
+	.rcv_buf = mux_pt_rcv_buf,
+	.snd_buf = mux_pt_snd_buf,
+#if defined(CONFIG_HAP_LINUX_SPLICE)
+	.rcv_pipe = mux_pt_rcv_pipe,
+	.snd_pipe = mux_pt_snd_pipe,
+#endif
+	.attach = mux_pt_attach,
+	.detach = mux_pt_detach,
+	.shutr = mux_pt_shutr,
+	.shutw = mux_pt_shutw,
 	.name = "PASS",
 };