From: Matt Joiner <anacrolix@gmail.com>
Date: Wed, 5 Aug 2015 22:59:30 +0000 (+1000)
Subject: dht: Short circuit non-DHT traffic
X-Git-Tag: v1.0.0~1071
X-Git-Url: http://www.git.stargrave.org/?a=commitdiff_plain;h=a7c374cff7616f68fadcbf146c219849992b6e43;p=btrtrc.git

dht: Short circuit non-DHT traffic
---

diff --git a/dht/dht.go b/dht/dht.go
index 6585a6ce..91276855 100644
--- a/dht/dht.go
+++ b/dht/dht.go
@@ -604,6 +604,11 @@ func (s *Server) init() (err error) {
 }
 
 func (s *Server) processPacket(b []byte, addr dHTAddr) {
+	if len(b) < 2 || b[0] != 'd' || b[len(b)-1] != 'e' {
+		// KRPC messages are bencoded dicts.
+		readNotKRPCDict.Add(1)
+		return
+	}
 	var d Msg
 	err := bencode.Unmarshal(b, &d)
 	if err != nil {
diff --git a/dht/expvar.go b/dht/expvar.go
index fe1fc06c..4fdf69ce 100644
--- a/dht/expvar.go
+++ b/dht/expvar.go
@@ -7,6 +7,7 @@ import (
 var (
 	read               = expvar.NewInt("dhtRead")
 	readBlocked        = expvar.NewInt("dhtReadBlocked")
+	readNotKRPCDict    = expvar.NewInt("dhtReadNotKRPCDict")
 	readUnmarshalError = expvar.NewInt("dhtReadUnmarshalError")
 	readQuery          = expvar.NewInt("dhtReadQuery")
 	announceErrors     = expvar.NewInt("dhtAnnounceErrors")