p2p: prevent connections from same ip

p2p/errors.go

@@ -1,14 +1,32 @@
 package p2p
 
 import (
-	"errors"
 	"fmt"
 )
 
-var (
-	ErrSwitchDuplicatePeer = errors.New("Duplicate peer")
-	ErrSwitchConnectToSelf = errors.New("Connect to self")
-)
+type ErrSwitchDuplicatePeerID struct {
+	ID ID
+}
+
+func (e ErrSwitchDuplicatePeerID) Error() string {
+	return fmt.Errorf("Duplicate peer ID %v", e.ID)
+}
+
+type ErrSwitchDuplicatePeerIP struct {
+	Addr string
+}
+
+func (e ErrSwitchDuplicatePeerIP) Error() string {
+	return fmt.Errorf("Duplicate peer IP %v", e.Addr)
+}
+
+type ErrSwitchConnectToSelf struct {
+	Addr *NetAddress
+}
+
+func (e ErrSwitchConnectToSelf) Error() string {
+	return fmt.Errorf("Connect to self: %v", e.Addr)
+}
 
 type ErrSwitchAuthenticationFailure struct {
 	Dialed *NetAddress

p2p/peer.go

@@ -17,6 +17,7 @@ type Peer interface {
 	cmn.Service
 
 	ID() ID             // peer's cryptographic ID
+	RemoteIP() string   // remote IP of the connection
 	IsOutbound() bool   // did we dial the peer
 	IsPersistent() bool // do we redial this peer when we disconnect
 	NodeInfo() NodeInfo // peer's info
@@ -45,6 +46,15 @@ func (pc peerConn) ID() ID {
 	return PubKeyToID(pc.conn.(*tmconn.SecretConnection).RemotePubKey())
 }
 
+// Return the IP from the connection RemoteAddr
+func (pc peerConn) RemoteIP() string {
+	host, _, err := net.SplitHostPort(pc.conn.RemoteAddr().String())
+	if err != nil {
+		panic(err)
+	}
+	return host
+}
+
 // peer implements Peer.
 //
 // Before using a peer, you will need to perform a handshake on connection.

p2p/peer_set.go

@@ -7,6 +7,7 @@ import (
 // IPeerSet has a (immutable) subset of the methods of PeerSet.
 type IPeerSet interface {
 	Has(key ID) bool
+	HasIP(ip string) bool
 	Get(key ID) Peer
 	List() []Peer
 	Size() int
@@ -17,9 +18,10 @@ type IPeerSet interface {
 // PeerSet is a special structure for keeping a table of peers.
 // Iteration over the peers is super fast and thread-safe.
 type PeerSet struct {
-	mtx    sync.Mutex
-	lookup map[ID]*peerSetItem
-	list   []Peer
+	mtx      sync.Mutex
+	lookup   map[ID]*peerSetItem
+	lookupIP map[string]struct{}
+	list     []Peer
 }
 
 type peerSetItem struct {
@@ -30,8 +32,9 @@ type peerSetItem struct {
 // NewPeerSet creates a new peerSet with a list of initial capacity of 256 items.
 func NewPeerSet() *PeerSet {
 	return &PeerSet{
-		lookup: make(map[ID]*peerSetItem),
-		list:   make([]Peer, 0, 256),
+		lookup:   make(map[ID]*peerSetItem),
+		lookupIP: make(map[string]struct{}),
+		list:     make([]Peer, 0, 256),
 	}
 }
 
@@ -41,7 +44,10 @@ func (ps *PeerSet) Add(peer Peer) error {
 	ps.mtx.Lock()
 	defer ps.mtx.Unlock()
 	if ps.lookup[peer.ID()] != nil {
-		return ErrSwitchDuplicatePeer
+		return ErrSwitchDuplicatePeerID{peer.ID()}
+	}
+	if _, ok := ps.lookupIP[peer.RemoteIP()]; ok {
+		return ErrSwitchDuplicatePeerIP{peer.RemoteIP()}
 	}
 
 	index := len(ps.list)
@@ -49,6 +55,7 @@ func (ps *PeerSet) Add(peer Peer) error {
 	// iterating over the ps.list slice.
 	ps.list = append(ps.list, peer)
 	ps.lookup[peer.ID()] = &peerSetItem{peer, index}
+	ps.lookupIP[peer.RemoteIP()] = struct{}{}
 	return nil
 }
 
@@ -61,6 +68,15 @@ func (ps *PeerSet) Has(peerKey ID) bool {
 	return ok
 }
 
+// HasIP returns true iff the PeerSet contains
+// the peer referred to by this IP address.
+func (ps *PeerSet) HasIP(peerIP string) bool {
+	ps.mtx.Lock()
+	_, ok := ps.lookupIP[peerIP]
+	ps.mtx.Unlock()
+	return ok
+}
+
 // Get looks up a peer by the provided peerKey.
 func (ps *PeerSet) Get(peerKey ID) Peer {
 	ps.mtx.Lock()
@@ -76,6 +92,7 @@ func (ps *PeerSet) Get(peerKey ID) Peer {
 func (ps *PeerSet) Remove(peer Peer) {
 	ps.mtx.Lock()
 	defer ps.mtx.Unlock()
+	delete(ps.lookupIP[peer.RemoteIP()])
 	item := ps.lookup[peer.ID()]
 	if item == nil {
 		return

p2p/switch.go

@@ -403,7 +403,7 @@ func (sw *Switch) DialPeersAsync(addrBook AddrBook, peers []string, persistent b
 			sw.randomSleep(0)
 			err := sw.DialPeerWithAddress(addr, persistent)
 			if err != nil {
-				switch err {
+				switch err.(type) {
 				case ErrSwitchConnectToSelf, ErrSwitchDuplicatePeer:
 					sw.Logger.Debug("Error dialing peer", "err", err)
 				default:
@@ -534,6 +534,8 @@ func (sw *Switch) addPeer(pc peerConn) error {
 		return err
 	}
 
+	// dont connect to multiple peers on the same IP
+
 	// NOTE: if AuthEnc==false, we don't have a peerID until after the handshake.
 	// If AuthEnc==true then we already know the ID and could do the checks first before the handshake,
 	// but it's simple to just deal with both cases the same after the handshake.
@@ -564,20 +566,24 @@ func (sw *Switch) addPeer(pc peerConn) error {
 	// Avoid self
 	if sw.nodeKey.ID() == peerID {
 		addr := peerNodeInfo.NetAddress()
-
-		// remove the given address from the address book if we added it earlier
+		// remove the given address from the address book
+		// and add to our addresses to avoid dialing again
 		sw.addrBook.RemoveAddress(addr)
-
-		// add the given address to the address book to avoid dialing ourselves
-		// again this is our public address
 		sw.addrBook.AddOurAddress(addr)
-
-		return ErrSwitchConnectToSelf
+		return ErrSwitchConnectToSelf{addr}
 	}
 
 	// Avoid duplicate
 	if sw.peers.Has(peerID) {
-		return ErrSwitchDuplicatePeer
+		return ErrSwitchDuplicatePeerID{peerID}
+	}
+
+	// check ips for both the connection addr and the self reported addr
+	if sw.peers.HasIP(addr) {
+		return ErrSwitchDuplicatePeerIP{addr}
+	}
+	if sw.peers.HasIP(peerNodeInfo.ListenAddr) {
+		return ErrSwitchDuplicatePeerIP{peerNodeInfo.ListenAddr}
 	}
 
 	// Filter peer against ID white list