From ef5b09563ff472be2a999abddf1c13c4b8abcc26 Mon Sep 17 00:00:00 2001
From: David Crawshaw <crawshaw@tailscale.com>
Date: Thu, 12 Mar 2020 11:10:55 -0400
Subject: [PATCH] derp: do not treat failure to relay as the fault of the
 sender

If Alice attempts to send a packet to Bob and the DERP server
encounters an error on the socket to Bob, we should not disconnect
Alice for that.

Signed-off-by: David Crawshaw <crawshaw@tailscale.com>
---
 derp/derp_server.go | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/derp/derp_server.go b/derp/derp_server.go
index 8ffbe6eea..e7dd59542 100644
--- a/derp/derp_server.go
+++ b/derp/derp_server.go
@@ -320,7 +320,9 @@ func (c *sclient) handleFrameSendPacket(ctx context.Context, ft frameType, fl ui
 		}
 		s.mu.Unlock()
 	}
-	return err
+
+	// Do not treat a send error as an error with this transmitting client.
+	return nil
 }
 
 func (s *Server) sendClientKeepAlives(ctx context.Context, c *sclient) {