p2p: Reject addrs coming from private peers (#2032)

Refs #1706

CHANGELOG.md

@@ -11,6 +11,7 @@ BREAKING CHANGES:
 IMPROVEMENTS:
 - [abci, libs/common] Generated gogoproto static marshaller methods
 - [config] Increase default send/recv rates to 5 mB/s
+- [p2p] reject addresses coming from private peers
 - [p2p] allow persistent peers to be private
 
 BUG FIXES:

docs/spec/reactors/pex/pex.md

@@ -12,7 +12,8 @@ them.
 Some peers can be marked as `private`, which means
 we will not put them in the address book or gossip them to others.
 
-All peers except private peers are tracked using the address book.
+All peers except private peers and peers coming from them are tracked using the
+address book.
 
 ## Discovery
 

p2p/pex/addrbook.go

@@ -638,6 +638,7 @@ func (a *addrBook) addAddress(addr, src *p2p.NetAddress) error {
 	if a.routabilityStrict && !addr.Routable() {
 		return ErrAddrBookNonRoutable{addr}
 	}
+
 	// TODO: we should track ourAddrs by ID and by IP:PORT and refuse both.
 	if _, ok := a.ourAddrs[addr.String()]; ok {
 		return ErrAddrBookSelf{addr}
@@ -647,6 +648,10 @@ func (a *addrBook) addAddress(addr, src *p2p.NetAddress) error {
 		return ErrAddrBookPrivate{addr}
 	}
 
+	if _, ok := a.privateIDs[src.ID]; ok {
+		return ErrAddrBookPrivateSrc{src}
+	}
+
 	ka := a.addrLookup[addr.ID]
 	if ka != nil {
 		// If its already old and the addr is the same, ignore it.

p2p/pex/addrbook_test.go

@@ -8,7 +8,6 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
 
 	cmn "github.com/tendermint/tendermint/libs/common"
 	"github.com/tendermint/tendermint/libs/log"
@@ -374,10 +373,19 @@ func TestPrivatePeers(t *testing.T) {
 	}
 	book.AddPrivateIDs(private)
 
+	// private addrs must not be added
 	for _, addr := range addrs {
 		err := book.AddAddress(addr, addr)
-		require.Error(t, err, "AddAddress should have failed with private peer %s", addr)
-		_, ok := err.(ErrAddrBookPrivate)
-		require.True(t, ok, "Wrong error type, wanted ErrAddrBookPrivate, got error: %s", err)
+		if assert.Error(t, err) {
+			_, ok := err.(ErrAddrBookPrivate)
+			assert.True(t, ok)
+		}
+	}
+
+	// addrs coming from private peers must not be added
+	err := book.AddAddress(randIPv4Address(t), addrs[0])
+	if assert.Error(t, err) {
+		_, ok := err.(ErrAddrBookPrivateSrc)
+		assert.True(t, ok)
 	}
 }

p2p/pex/errors.go

@@ -30,6 +30,14 @@ func (err ErrAddrBookPrivate) Error() string {
 	return fmt.Sprintf("Cannot add private peer with address %v", err.Addr)
 }
 
+type ErrAddrBookPrivateSrc struct {
+	Src *p2p.NetAddress
+}
+
+func (err ErrAddrBookPrivateSrc) Error() string {
+	return fmt.Sprintf("Cannot add peer coming from private peer with address %v", err.Src)
+}
+
 type ErrAddrBookNilAddr struct {
 	Addr *p2p.NetAddress
 	Src  *p2p.NetAddress