From 08d7c1e4af30bf42691653b8a0d07ef85b0aced4 Mon Sep 17 00:00:00 2001
From: Sir Darkrengarius <darkren92@gmail.com>
Date: Thu, 6 Feb 2020 20:31:43 +0300
Subject: [PATCH] Start fixing

---
 pkg/router/route_group.go | 60 +++++++++++++++++++++++++++++++++++++--
 pkg/router/router.go      |  9 ++----
 2 files changed, 60 insertions(+), 9 deletions(-)

diff --git a/pkg/router/route_group.go b/pkg/router/route_group.go
index 6a3ebfd1ad..a88b58c9ee 100644
--- a/pkg/router/route_group.go
+++ b/pkg/router/route_group.go
@@ -76,8 +76,9 @@ type RouteGroup struct {
 	// - fwd/tps should have the same number of elements.
 	// - the corresponding element of tps should have tpID of the corresponding rule in fwd.
 	// - fwd references 'ForwardRule' rules for writes.
-	fwd []routing.Rule // forward rules (for writing)
-	rvs []routing.Rule // reverse rules (for reading)
+	fwd                  []routing.Rule // forward rules (for writing)
+	rvs                  []routing.Rule // reverse rules (for reading)
+	rvsRouteLastActivity time.Time
 
 	lastSent int64
 
@@ -123,6 +124,7 @@ func NewRouteGroup(cfg *RouteGroupConfig, rt routing.Table, desc routing.RouteDe
 	}
 
 	go rg.keepAliveLoop(cfg.KeepAliveInterval)
+	go rg.checkRouteIsAliveLoop()
 
 	return rg
 }
@@ -427,6 +429,33 @@ func (rg *RouteGroup) close(code routing.CloseCode) error {
 	return nil
 }
 
+func (rg *RouteGroup) handlePacket(packet routing.Packet) error {
+	rg.mu.Lock()
+	// no need to check rule expiry, since router won't allow packet in
+	// in case it's expired, so simply update the activity
+	rg.rvsRouteLastActivity = time.Now()
+	rg.mu.Unlock()
+
+	switch packet.Type() {
+	case routing.ClosePacket:
+		return rg.handleClosePacket(routing.CloseCode(packet.Payload()[0]))
+	case routing.DataPacket:
+		return rg.handleDataPacket(packet)
+	}
+
+	return nil
+}
+
+func (rg *RouteGroup) handleDataPacket(packet routing.Packet) error {
+	select {
+	case <-rg.closed:
+		return io.ErrClosedPipe
+	case rg.readCh <- packet.Payload():
+	}
+
+	return nil
+}
+
 func (rg *RouteGroup) handleClosePacket(code routing.CloseCode) error {
 	rg.logger.Infof("Got close packet with code %d", code)
 
@@ -471,6 +500,33 @@ func (rg *RouteGroup) waitForCloseLoop(waitTimeout time.Duration) error {
 	return nil
 }
 
+func (rg *RouteGroup) checkRouteIsAliveLoop() {
+	ticker := time.NewTicker(routing.DefaultGCInterval)
+	defer ticker.Stop()
+
+	for range ticker.C {
+		rg.mu.Lock()
+		rule, err := rg.rule()
+		if err != nil {
+			rg.mu.Unlock()
+			rg.logger.Errorf("Error getting rule to check activity: %v", err)
+			continue
+		}
+
+		idling := time.Since(rg.rvsRouteLastActivity)
+		keepAlive := rule.KeepAlive()
+
+		if idling > keepAlive {
+			// rule is timed out, remote closed, stop this loop
+
+			rg.mu.Unlock()
+			return
+		}
+
+		rg.mu.Unlock()
+	}
+}
+
 func (rg *RouteGroup) isCloseInitiator() bool {
 	return atomic.LoadInt32(&rg.closeInitiated) == 1
 }
diff --git a/pkg/router/router.go b/pkg/router/router.go
index 71e98906d3..9157009d92 100644
--- a/pkg/router/router.go
+++ b/pkg/router/router.go
@@ -368,12 +368,7 @@ func (r *router) handleDataPacket(ctx context.Context, packet routing.Packet) er
 	r.logger.Infof("Got new remote packet with route ID %d. Using rule: %s", packet.RouteID(), rule)
 	r.logger.Infof("Packet contents (len = %d): %v", len(packet.Payload()), packet.Payload())
 
-	select {
-	case <-rg.closed:
-		return io.ErrClosedPipe
-	case rg.readCh <- packet.Payload():
-		return nil
-	}
+	return rg.handlePacket(packet)
 }
 
 func (r *router) handleClosePacket(ctx context.Context, packet routing.Packet) error {
@@ -421,7 +416,7 @@ func (r *router) handleClosePacket(ctx context.Context, packet routing.Packet) e
 		return io.ErrClosedPipe
 	}
 
-	if err := rg.handleClosePacket(closeCode); err != nil {
+	if err := rg.handlePacket(packet); err != nil {
 		return fmt.Errorf("error handling close packet with code %d by route group with descriptor %s: %v",
 			closeCode, &desc, err)
 	}