Merge pull request #1282 from tendermint/1126-private-peers

private peers

p2p/pex/pex_reactor.go

@@ -74,6 +74,10 @@ type PEXReactorConfig struct {
 	// Seeds is a list of addresses reactor may use
 	// if it can't connect to peers in the addrbook.
 	Seeds []string
+
+	// PrivatePeerIDs is a list of peer IDs, which must not be gossiped to other
+	// peers.
+	PrivatePeerIDs []string
 }
 
 type _attemptsToDial struct {
@@ -152,7 +156,9 @@ func (r *PEXReactor) AddPeer(p Peer) {
 		// Let the ensurePeersRoutine handle asking for more
 		// peers when we need - we don't trust inbound peers as much.
 		addr := p.NodeInfo().NetAddress()
-		r.book.AddAddress(addr, addr)
+		if !isAddrPrivate(addr, r.config.PrivatePeerIDs) {
+			r.book.AddAddress(addr, addr)
+		}
 	}
 }
 
@@ -252,7 +258,7 @@ func (r *PEXReactor) ReceiveAddrs(addrs []*p2p.NetAddress, src Peer) error {
 
 	srcAddr := src.NodeInfo().NetAddress()
 	for _, netAddr := range addrs {
-		if netAddr != nil {
+		if netAddr != nil && !isAddrPrivate(netAddr, r.config.PrivatePeerIDs) {
 			r.book.AddAddress(netAddr, srcAddr)
 		}
 	}
@@ -580,6 +586,16 @@ func (r *PEXReactor) attemptDisconnects() {
 	}
 }
 
+// isAddrPrivate returns true if addr is private.
+func isAddrPrivate(addr *p2p.NetAddress, privatePeerIDs []string) bool {
+	for _, id := range privatePeerIDs {
+		if string(addr.ID) == id {
+			return true
+		}
+	}
+	return false
+}
+
 //-----------------------------------------------------------------------------
 // Messages
 

p2p/pex/pex_reactor_test.go

@@ -268,6 +268,25 @@ func TestPEXReactorCrawlStatus(t *testing.T) {
 	// TODO: test
 }
 
+func TestPEXReactorDoesNotAddPrivatePeersToAddrBook(t *testing.T) {
+	peer := p2p.CreateRandomPeer(false)
+
+	pexR, book := createReactor(&PEXReactorConfig{PrivatePeerIDs: []string{string(peer.NodeInfo().ID())}})
+	defer teardownReactor(book)
+
+	// we have to send a request to receive responses
+	pexR.RequestAddrs(peer)
+
+	size := book.Size()
+	addrs := []*p2p.NetAddress{peer.NodeInfo().NetAddress()}
+	msg := wire.BinaryBytes(struct{ PexMessage }{&pexAddrsMessage{Addrs: addrs}})
+	pexR.Receive(PexChannel, peer, msg)
+	assert.Equal(t, size, book.Size())
+
+	pexR.AddPeer(peer)
+	assert.Equal(t, size, book.Size())
+}
+
 func TestPEXReactorDialPeer(t *testing.T) {
 	pexR, book := createReactor(&PEXReactorConfig{})
 	defer teardownReactor(book)
@@ -376,7 +395,7 @@ func createReactor(config *PEXReactorConfig) (r *PEXReactor, book *addrBook) {
 	book = NewAddrBook(filepath.Join(dir, "addrbook.json"), true)
 	book.SetLogger(log.TestingLogger())
 
-	r = NewPEXReactor(book, &PEXReactorConfig{})
+	r = NewPEXReactor(book, config)
 	r.SetLogger(log.TestingLogger())
 	return
 }