From 9bcb1d53a6b0b474c1aab9373d323d210b60e6b0 Mon Sep 17 00:00:00 2001
From: Steven Allen <steven@stebalien.com>
Date: Thu, 8 Mar 2018 10:46:19 -0800
Subject: [PATCH 1/2] more correctly handle close and errors

1. Only propagate close on successful EOF.
2. Reset *both* streams on error.
---
 .../internal/circuitv1-deprecated/relay.go     | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/p2p/protocol/internal/circuitv1-deprecated/relay.go b/p2p/protocol/internal/circuitv1-deprecated/relay.go
index edeafc9a84..91ba7f23c6 100644
--- a/p2p/protocol/internal/circuitv1-deprecated/relay.go
+++ b/p2p/protocol/internal/circuitv1-deprecated/relay.go
@@ -293,19 +293,29 @@ func (r *Relay) handleHopStream(s inet.Stream, msg *pb.CircuitRelay) {
 	// error, not an EOF.
 	go func() {
 		count, err := io.Copy(s, bs)
-		if err != io.EOF && err != nil {
+		if err != nil {
 			log.Debugf("relay copy error: %s", err)
+			// Reset both.
+			s.Reset()
+			bs.Reset()
+		} else {
+			// propagate the close
+			s.Close()
 		}
-		s.Close()
 		log.Debugf("relayed %d bytes from %s to %s", count, dst.ID.Pretty(), src.ID.Pretty())
 	}()
 
 	go func() {
 		count, err := io.Copy(bs, s)
-		if err != io.EOF && err != nil {
+		if err != nil {
 			log.Debugf("relay copy error: %s", err)
+			// Reset both.
+			bs.Reset()
+			s.Reset()
+		} else {
+			// propagate the close
+			bs.Close()
 		}
-		bs.Close()
 		log.Debugf("relayed %d bytes from %s to %s", count, src.ID.Pretty(), dst.ID.Pretty())
 	}()
 }

From b64da1fd89c2a263ec22c1613d9a4c195cf41e32 Mon Sep 17 00:00:00 2001
From: Steven Allen <steven@stebalien.com>
Date: Thu, 8 Mar 2018 10:51:35 -0800
Subject: [PATCH 2/2] test resetting relay connections

---
 .../circuitv1-deprecated/relay_test.go        | 61 +++++++++++++++++++
 1 file changed, 61 insertions(+)

diff --git a/p2p/protocol/internal/circuitv1-deprecated/relay_test.go b/p2p/protocol/internal/circuitv1-deprecated/relay_test.go
index 05c1154015..0b655e2ad3 100644
--- a/p2p/protocol/internal/circuitv1-deprecated/relay_test.go
+++ b/p2p/protocol/internal/circuitv1-deprecated/relay_test.go
@@ -111,6 +111,67 @@ func TestBasicRelay(t *testing.T) {
 	}
 }
 
+func TestRelayReset(t *testing.T) {
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	hosts := getNetHosts(t, ctx, 3)
+
+	connect(t, hosts[0], hosts[1])
+	connect(t, hosts[1], hosts[2])
+
+	time.Sleep(10 * time.Millisecond)
+
+	r1, err := NewRelay(ctx, hosts[0])
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	_, err = NewRelay(ctx, hosts[1], OptHop)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	r3, err := NewRelay(ctx, hosts[2])
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	msg := []byte("relay works!")
+	go func() {
+		list := r3.Listener()
+
+		con, err := list.Accept()
+		if err != nil {
+			t.Error(err)
+			return
+		}
+
+		_, err = con.Write(msg)
+		if err != nil {
+			t.Error(err)
+			return
+		}
+		hosts[2].Close()
+	}()
+
+	rinfo := hosts[1].Peerstore().PeerInfo(hosts[1].ID())
+	dinfo := hosts[2].Peerstore().PeerInfo(hosts[2].ID())
+
+	rctx, rcancel := context.WithTimeout(ctx, time.Second)
+	defer rcancel()
+
+	con, err := r1.DialPeer(rctx, rinfo, dinfo)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	_, err = ioutil.ReadAll(con)
+	if err == nil {
+		t.Fatal("expected error for reset relayed connection")
+	}
+}
+
 func TestBasicRelayDial(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()