MINOR: conn_stream: Add a flag to notify the SI some data were received

The flag CS_FL_READ_PARTIAL can be set by the mux on the conn_stream to notify
the stream interface that some data were received. Is is used in si_cs_recv to
re-arm read timeout on the channel.
diff --git a/include/types/connection.h b/include/types/connection.h
index 7256219..dbf985b 100644
--- a/include/types/connection.h
+++ b/include/types/connection.h
@@ -82,7 +82,11 @@
 	CS_FL_REOS          = 0x00002000,  /* End of stream received (buffer not empty) */
 	CS_FL_WAIT_FOR_HS   = 0x00010000,  /* This stream is waiting for handhskae */
 
-	CS_FL_NOT_FIRST     = 0x00100000,  /* This stream is not the first one */
+	/* following flags are supposed to be set by the mux and read/unset by
+	 * the stream-interface :
+	 */
+	CS_FL_NOT_FIRST     = 0x00100000,  /* this stream is not the first one */
+	CS_FL_READ_PARTIAL  = 0x00200000,  /* some data were received (not necessarly xferred) */
 };
 
 /* cs_shutr() modes */
diff --git a/src/stream_interface.c b/src/stream_interface.c
index 3c7284f..1f82959 100644
--- a/src/stream_interface.c
+++ b/src/stream_interface.c
@@ -1217,6 +1217,12 @@
 		if (cs->flags & CS_FL_RCV_MORE)
 			si_rx_room_blk(si);
 
+		if (cs->flags & CS_FL_READ_PARTIAL) {
+			if (tick_isset(ic->rex))
+				ic->rex = tick_add_ifset(now_ms, ic->rto);
+			cs->flags &= ~CS_FL_READ_PARTIAL;
+		}
+
 		if (ret <= 0) {
 			break;
 		}