avoid connection to self

p2p/pex_reactor.go

@@ -212,10 +212,11 @@ func (pexR *PEXReactor) ensurePeers() {
 
 	// if no addresses to dial, pick a random connected peer and ask for more peers
 	if toDial.Size() == 0 {
-		peers := pexR.sw.Peers().List()
-		i := rand.Int() % len(peers)
-		log.Debug("No addresses to dial. Sending pexRequest to random peer", "peer", peers[i])
-		pexR.RequestPEX(peers[i])
+		if peers := pexR.sw.Peers().List(); len(peers) > 0 {
+			i := rand.Int() % len(peers)
+			log.Debug("No addresses to dial. Sending pexRequest to random peer", "peer", peers[i])
+			pexR.RequestPEX(peers[i])
+		}
 	}
 }
 

p2p/switch.go

@@ -171,10 +171,16 @@ func (sw *Switch) AddPeerWithConnection(conn net.Conn, outbound bool) (*Peer, er
 		conn.Close()
 		return nil, err
 	}
+	// check version, chain id
 	if err := sw.nodeInfo.CompatibleWith(peerNodeInfo); err != nil {
 		conn.Close()
 		return nil, err
 	}
+	// avoid self
+	if peerNodeInfo.UUID == sw.nodeInfo.UUID {
+		conn.Close()
+		return nil, fmt.Errorf("Ignoring connection from self")
+	}
 
 	// the peerNodeInfo is not verified,
 	// so we overwrite the IP with that from the conn

p2p/switch_test.go

@@ -9,6 +9,8 @@ import (
 	"github.com/tendermint/tendermint/binary"
 	. "github.com/tendermint/tendermint/common"
 	"github.com/tendermint/tendermint/types"
+
+	"github.com/tendermint/tendermint/Godeps/_workspace/src/code.google.com/p/go-uuid/uuid"
 )
 
 type PeerMessage struct {
@@ -78,12 +80,14 @@ func makeSwitchPair(t testing.TB, initSwitch func(*Switch) *Switch) (*Switch, *S
 		Moniker: "switch1",
 		ChainID: "testing",
 		Version: "123.123.123",
+		UUID:    uuid.New(),
 	})
 	s2 := initSwitch(NewSwitch())
 	s2.SetNodeInfo(&types.NodeInfo{
 		Moniker: "switch2",
 		ChainID: "testing",
 		Version: "123.123.123",
+		UUID:    uuid.New(),
 	})
 
 	// Start switches