client: enable freeing relay flows based on inactivity

client/client.c

@@ -2144,7 +2144,7 @@ out:
     
     // relay frame
     if (relay_dest) {
-        DPRelaySource_SubmitFrame(&src_peer->relay_source, &relay_dest->relay_sink, data, data_len, options.send_buffer_relay_size, -1);
+        DPRelaySource_SubmitFrame(&src_peer->relay_source, &relay_dest->relay_sink, data, data_len, options.send_buffer_relay_size, PEER_RELAY_FLOW_INACTIVITY_TIME);
     }
     
     // inform DataProto of received packet

client/client.h

@@ -64,6 +64,8 @@
 #define PEER_DEFAULT_SEND_BUFFER_SIZE 32
 // size of frame send buffer for relayed packets, in number of frames
 #define PEER_DEFAULT_SEND_BUFFER_RELAY_SIZE 32
+// time after an unused relay flow is freed (-1 for never)
+#define PEER_RELAY_FLOW_INACTIVITY_TIME 10000
 // retry time
 #define PEER_RETRY_TIME 5000