p2p/enode: improve IPv6 support, add ENR text representation (#19663)

* p2p/enr: add entries for for IPv4/IPv6 separation

This adds entry types for "ip6", "udp6", "tcp6" keys. The IP type stays
around because removing it would break a lot of code and force everyone
to care about the distinction.

* p2p/enode: track IPv4 and IPv6 address separately

LocalNode predicts the local node's UDP endpoint and updates the record.
This change makes it predict IPv4 and IPv6 endpoints separately since
they can now be in the record at the same time.

* p2p/enode: implement base64 text format
* all: switch to enode.Parse(...)

This allows passing base64-encoded node records to all the places that
previously accepted enode:// URLs. The URL format is still supported.

* cmd/bootnode, p2p: log node URL instead of ENR

...and return the base64 record in NodeInfo.

cmd/bootnode/main.go

@@ -143,7 +143,7 @@ func printNotice(nodeKey *ecdsa.PublicKey, addr net.UDPAddr) {
 		addr.IP = net.IP{127, 0, 0, 1}
 	}
 	n := enode.NewV4(nodeKey, addr.IP, 0, addr.Port)
-	fmt.Println(n.String())
+	fmt.Println(n.URLv4())
 	fmt.Println("Note: you're using cmd/bootnode, a developer tool.")
 	fmt.Println("We recommend using a regular node as bootstrap node for production deployments.")
 }

cmd/faucet/faucet.go

@@ -260,7 +260,7 @@ func newFaucet(genesis *core.Genesis, port int, enodes []*discv5.Node, network u
 		return nil, err
 	}
 	for _, boot := range enodes {
-		old, err := enode.ParseV4(boot.String())
+		old, err := enode.Parse(enode.ValidSchemes, boot.String())
 		if err == nil {
 			stack.Server().AddPeer(old)
 		}

cmd/utils/flags.go

@@ -794,7 +794,7 @@ func setBootstrapNodes(ctx *cli.Context, cfg *p2p.Config) {
 	cfg.BootstrapNodes = make([]*enode.Node, 0, len(urls))
 	for _, url := range urls {
 		if url != "" {
-			node, err := enode.ParseV4(url)
+			node, err := enode.Parse(enode.ValidSchemes, url)
 			if err != nil {
 				log.Crit("Bootstrap URL invalid", "enode", url, "err", err)
 				continue

cmd/wnode/main.go

@@ -203,7 +203,7 @@ func initialize() {
 		if len(*argEnode) == 0 {
 			argEnode = scanLineA("Please enter the peer's enode: ")
 		}
-		peer := enode.MustParseV4(*argEnode)
+		peer := enode.MustParse(*argEnode)
 		peers = append(peers, peer)
 	}
 
@@ -747,9 +747,9 @@ func requestExpiredMessagesLoop() {
 }
 
 func extractIDFromEnode(s string) []byte {
-	n, err := enode.ParseV4(s)
+	n, err := enode.Parse(enode.ValidSchemes, s)
 	if err != nil {
-		utils.Fatalf("Failed to parse enode: %s", err)
+		utils.Fatalf("Failed to parse node: %s", err)
 	}
 	return n.ID().Bytes()
 }

les/serverpool.go

@@ -505,7 +505,7 @@ func parseTrustedNodes(trustedNodes []string) map[enode.ID]*enode.Node {
 	nodes := make(map[enode.ID]*enode.Node)
 
 	for _, node := range trustedNodes {
-		node, err := enode.ParseV4(node)
+		node, err := enode.Parse(enode.ValidSchemes, node)
 		if err != nil {
 			log.Warn("Trusted node URL invalid", "enode", node, "err", err)
 			continue

les/ulc.go

@@ -34,7 +34,7 @@ func newULC(ulcConfig *eth.ULCConfig) *ulc {
 	}
 	m := make(map[string]struct{}, len(ulcConfig.TrustedServers))
 	for _, id := range ulcConfig.TrustedServers {
-		node, err := enode.ParseV4(id)
+		node, err := enode.Parse(enode.ValidSchemes, id)
 		if err != nil {
 			log.Debug("Failed to parse trusted server", "id", id, "err", err)
 			continue

node/api.go

@@ -49,7 +49,7 @@ func (api *PrivateAdminAPI) AddPeer(url string) (bool, error) {
 		return false, ErrNodeStopped
 	}
 	// Try to add the url as a static peer and return
-	node, err := enode.ParseV4(url)
+	node, err := enode.Parse(enode.ValidSchemes, url)
 	if err != nil {
 		return false, fmt.Errorf("invalid enode: %v", err)
 	}
@@ -65,7 +65,7 @@ func (api *PrivateAdminAPI) RemovePeer(url string) (bool, error) {
 		return false, ErrNodeStopped
 	}
 	// Try to remove the url as a static peer and return
-	node, err := enode.ParseV4(url)
+	node, err := enode.Parse(enode.ValidSchemes, url)
 	if err != nil {
 		return false, fmt.Errorf("invalid enode: %v", err)
 	}
@@ -80,7 +80,7 @@ func (api *PrivateAdminAPI) AddTrustedPeer(url string) (bool, error) {
 	if server == nil {
 		return false, ErrNodeStopped
 	}
-	node, err := enode.ParseV4(url)
+	node, err := enode.Parse(enode.ValidSchemes, url)
 	if err != nil {
 		return false, fmt.Errorf("invalid enode: %v", err)
 	}
@@ -96,7 +96,7 @@ func (api *PrivateAdminAPI) RemoveTrustedPeer(url string) (bool, error) {
 	if server == nil {
 		return false, ErrNodeStopped
 	}
-	node, err := enode.ParseV4(url)
+	node, err := enode.Parse(enode.ValidSchemes, url)
 	if err != nil {
 		return false, fmt.Errorf("invalid enode: %v", err)
 	}

node/config.go

@@ -425,7 +425,7 @@ func (c *Config) parsePersistentNodes(w *bool, path string) []*enode.Node {
 		if url == "" {
 			continue
 		}
-		node, err := enode.ParseV4(url)
+		node, err := enode.Parse(enode.ValidSchemes, url)
 		if err != nil {
 			log.Error(fmt.Sprintf("Node URL %s: %v\n", url, err))
 			continue

p2p/discover/v4_udp_test.go

@@ -342,10 +342,10 @@ func TestUDPv4_findnodeMultiReply(t *testing.T) {
 
 	// send the reply as two packets.
 	list := []*node{
-		wrapNode(enode.MustParseV4("enode://ba85011c70bcc5c04d8607d3a0ed29aa6179c092cbdda10d5d32684fb33ed01bd94f588ca8f91ac48318087dcb02eaf36773a7a453f0eedd6742af668097b29c@10.0.1.16:30303?discport=30304")),
-		wrapNode(enode.MustParseV4("enode://81fa361d25f157cd421c60dcc28d8dac5ef6a89476633339c5df30287474520caca09627da18543d9079b5b288698b542d56167aa5c09111e55acdbbdf2ef799@10.0.1.16:30303")),
-		wrapNode(enode.MustParseV4("enode://9bffefd833d53fac8e652415f4973bee289e8b1a5c6c4cbe70abf817ce8a64cee11b823b66a987f51aaa9fba0d6a91b3e6bf0d5a5d1042de8e9eeea057b217f8@10.0.1.36:30301?discport=17")),
-		wrapNode(enode.MustParseV4("enode://1b5b4aa662d7cb44a7221bfba67302590b643028197a7d5214790f3bac7aaa4a3241be9e83c09cf1f6c69d007c634faae3dc1b1221793e8446c0b3a09de65960@10.0.1.16:30303")),
+		wrapNode(enode.MustParse("enode://ba85011c70bcc5c04d8607d3a0ed29aa6179c092cbdda10d5d32684fb33ed01bd94f588ca8f91ac48318087dcb02eaf36773a7a453f0eedd6742af668097b29c@10.0.1.16:30303?discport=30304")),
+		wrapNode(enode.MustParse("enode://81fa361d25f157cd421c60dcc28d8dac5ef6a89476633339c5df30287474520caca09627da18543d9079b5b288698b542d56167aa5c09111e55acdbbdf2ef799@10.0.1.16:30303")),
+		wrapNode(enode.MustParse("enode://9bffefd833d53fac8e652415f4973bee289e8b1a5c6c4cbe70abf817ce8a64cee11b823b66a987f51aaa9fba0d6a91b3e6bf0d5a5d1042de8e9eeea057b217f8@10.0.1.36:30301?discport=17")),
+		wrapNode(enode.MustParse("enode://1b5b4aa662d7cb44a7221bfba67302590b643028197a7d5214790f3bac7aaa4a3241be9e83c09cf1f6c69d007c634faae3dc1b1221793e8446c0b3a09de65960@10.0.1.16:30303")),
 	}
 	rpclist := make([]rpcNode, len(list))
 	for i := range list {

p2p/enode/localnode.go

@@ -48,23 +48,32 @@ type LocalNode struct {
 	db  *DB
 
 	// everything below is protected by a lock
-	mu          sync.Mutex
-	seq         uint64
-	entries     map[string]enr.Entry
-	udpTrack    *netutil.IPTracker // predicts external UDP endpoint
-	staticIP    net.IP
-	fallbackIP  net.IP
-	fallbackUDP int
+	mu        sync.Mutex
+	seq       uint64
+	entries   map[string]enr.Entry
+	endpoint4 lnEndpoint
+	endpoint6 lnEndpoint
+}
+
+type lnEndpoint struct {
+	track                *netutil.IPTracker
+	staticIP, fallbackIP net.IP
+	fallbackUDP          int
 }
 
 // NewLocalNode creates a local node.
 func NewLocalNode(db *DB, key *ecdsa.PrivateKey) *LocalNode {
 	ln := &LocalNode{
-		id:       PubkeyToIDV4(&key.PublicKey),
-		db:       db,
-		key:      key,
-		udpTrack: netutil.NewIPTracker(iptrackWindow, iptrackContactWindow, iptrackMinStatements),
-		entries:  make(map[string]enr.Entry),
+		id:      PubkeyToIDV4(&key.PublicKey),
+		db:      db,
+		key:     key,
+		entries: make(map[string]enr.Entry),
+		endpoint4: lnEndpoint{
+			track: netutil.NewIPTracker(iptrackWindow, iptrackContactWindow, iptrackMinStatements),
+		},
+		endpoint6: lnEndpoint{
+			track: netutil.NewIPTracker(iptrackWindow, iptrackContactWindow, iptrackMinStatements),
+		},
 	}
 	ln.seq = db.localSeq(ln.id)
 	ln.invalidate()
@@ -89,13 +98,22 @@ func (ln *LocalNode) Node() *Node {
 	return ln.cur.Load().(*Node)
 }
 
+// Seq returns the current sequence number of the local node record.
+func (ln *LocalNode) Seq() uint64 {
+	ln.mu.Lock()
+	defer ln.mu.Unlock()
+
+	return ln.seq
+}
+
 // ID returns the local node ID.
 func (ln *LocalNode) ID() ID {
 	return ln.id
 }
 
-// Set puts the given entry into the local record, overwriting
-// any existing value.
+// Set puts the given entry into the local record, overwriting any existing value.
+// Use Set*IP and SetFallbackUDP to set IP addresses and UDP port, otherwise they'll
+// be overwritten by the endpoint predictor.
 func (ln *LocalNode) Set(e enr.Entry) {
 	ln.mu.Lock()
 	defer ln.mu.Unlock()
@@ -127,13 +145,20 @@ func (ln *LocalNode) delete(e enr.Entry) {
 	}
 }
 
+func (ln *LocalNode) endpointForIP(ip net.IP) *lnEndpoint {
+	if ip.To4() != nil {
+		return &ln.endpoint4
+	}
+	return &ln.endpoint6
+}
+
 // SetStaticIP sets the local IP to the given one unconditionally.
 // This disables endpoint prediction.
 func (ln *LocalNode) SetStaticIP(ip net.IP) {
 	ln.mu.Lock()
 	defer ln.mu.Unlock()
 
-	ln.staticIP = ip
+	ln.endpointForIP(ip).staticIP = ip
 	ln.updateEndpoints()
 }
 
@@ -143,17 +168,18 @@ func (ln *LocalNode) SetFallbackIP(ip net.IP) {
 	ln.mu.Lock()
 	defer ln.mu.Unlock()
 
-	ln.fallbackIP = ip
+	ln.endpointForIP(ip).fallbackIP = ip
 	ln.updateEndpoints()
 }
 
-// SetFallbackUDP sets the last-resort UDP port. This port is used
+// SetFallbackUDP sets the last-resort UDP-on-IPv4 port. This port is used
 // if no endpoint prediction can be made.
 func (ln *LocalNode) SetFallbackUDP(port int) {
 	ln.mu.Lock()
 	defer ln.mu.Unlock()
 
-	ln.fallbackUDP = port
+	ln.endpoint4.fallbackUDP = port
+	ln.endpoint6.fallbackUDP = port
 	ln.updateEndpoints()
 }
 
@@ -163,7 +189,7 @@ func (ln *LocalNode) UDPEndpointStatement(fromaddr, endpoint *net.UDPAddr) {
 	ln.mu.Lock()
 	defer ln.mu.Unlock()
 
-	ln.udpTrack.AddStatement(fromaddr.String(), endpoint.String())
+	ln.endpointForIP(endpoint.IP).track.AddStatement(fromaddr.String(), endpoint.String())
 	ln.updateEndpoints()
 }
 
@@ -173,32 +199,50 @@ func (ln *LocalNode) UDPContact(toaddr *net.UDPAddr) {
 	ln.mu.Lock()
 	defer ln.mu.Unlock()
 
-	ln.udpTrack.AddContact(toaddr.String())
+	ln.endpointForIP(toaddr.IP).track.AddContact(toaddr.String())
 	ln.updateEndpoints()
 }
 
+// updateEndpoints updates the record with predicted endpoints.
 func (ln *LocalNode) updateEndpoints() {
-	// Determine the endpoints.
-	newIP := ln.fallbackIP
-	newUDP := ln.fallbackUDP
-	if ln.staticIP != nil {
-		newIP = ln.staticIP
-	} else if ip, port := predictAddr(ln.udpTrack); ip != nil {
-		newIP = ip
-		newUDP = port
-	}
+	ip4, udp4 := ln.endpoint4.get()
+	ip6, udp6 := ln.endpoint6.get()
 
-	// Update the record.
-	if newIP != nil && !newIP.IsUnspecified() {
-		ln.set(enr.IP(newIP))
-		if newUDP != 0 {
-			ln.set(enr.UDP(newUDP))
-		} else {
-			ln.delete(enr.UDP(0))
-		}
+	if ip4 != nil && !ip4.IsUnspecified() {
+		ln.set(enr.IPv4(ip4))
 	} else {
-		ln.delete(enr.IP{})
+		ln.delete(enr.IPv4{})
+	}
+	if ip6 != nil && !ip6.IsUnspecified() {
+		ln.set(enr.IPv6(ip6))
+	} else {
+		ln.delete(enr.IPv6{})
+	}
+	if udp4 != 0 {
+		ln.set(enr.UDP(udp4))
+	} else {
+		ln.delete(enr.UDP(0))
+	}
+	if udp6 != 0 && udp6 != udp4 {
+		ln.set(enr.UDP6(udp6))
+	} else {
+		ln.delete(enr.UDP6(0))
+	}
+}
+
+// get returns the endpoint with highest precedence.
+func (e *lnEndpoint) get() (newIP net.IP, newPort int) {
+	newPort = e.fallbackUDP
+	if e.fallbackIP != nil {
+		newIP = e.fallbackIP
+	}
+	if e.staticIP != nil {
+		newIP = e.staticIP
+	} else if ip, port := predictAddr(e.track); ip != nil {
+		newIP = ip
+		newPort = port
 	}
+	return newIP, newPort
 }
 
 // predictAddr wraps IPTracker.PredictEndpoint, converting from its string-based

p2p/enode/localnode_test.go

@@ -17,10 +17,13 @@
 package enode
 
 import (
+	"math/rand"
+	"net"
 	"testing"
 
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/p2p/enr"
+	"github.com/stretchr/testify/assert"
 )
 
 func newLocalNodeForTesting() (*LocalNode, *DB) {
@@ -74,3 +77,46 @@ func TestLocalNodeSeqPersist(t *testing.T) {
 		t.Fatalf("wrong seq %d on instance with changed key, want 1", s)
 	}
 }
+
+// This test checks behavior of the endpoint predictor.
+func TestLocalNodeEndpoint(t *testing.T) {
+	var (
+		fallback  = &net.UDPAddr{IP: net.IP{127, 0, 0, 1}, Port: 80}
+		predicted = &net.UDPAddr{IP: net.IP{127, 0, 1, 2}, Port: 81}
+		staticIP  = net.IP{127, 0, 1, 2}
+	)
+	ln, db := newLocalNodeForTesting()
+	defer db.Close()
+
+	// Nothing is set initially.
+	assert.Equal(t, net.IP(nil), ln.Node().IP())
+	assert.Equal(t, 0, ln.Node().UDP())
+	assert.Equal(t, uint64(1), ln.Node().Seq())
+
+	// Set up fallback address.
+	ln.SetFallbackIP(fallback.IP)
+	ln.SetFallbackUDP(fallback.Port)
+	assert.Equal(t, fallback.IP, ln.Node().IP())
+	assert.Equal(t, fallback.Port, ln.Node().UDP())
+	assert.Equal(t, uint64(2), ln.Node().Seq())
+
+	// Add endpoint statements from random hosts.
+	for i := 0; i < iptrackMinStatements; i++ {
+		assert.Equal(t, fallback.IP, ln.Node().IP())
+		assert.Equal(t, fallback.Port, ln.Node().UDP())
+		assert.Equal(t, uint64(2), ln.Node().Seq())
+
+		from := &net.UDPAddr{IP: make(net.IP, 4), Port: 90}
+		rand.Read(from.IP)
+		ln.UDPEndpointStatement(from, predicted)
+	}
+	assert.Equal(t, predicted.IP, ln.Node().IP())
+	assert.Equal(t, predicted.Port, ln.Node().UDP())
+	assert.Equal(t, uint64(3), ln.Node().Seq())
+
+	// Static IP overrides prediction.
+	ln.SetStaticIP(staticIP)
+	assert.Equal(t, staticIP, ln.Node().IP())
+	assert.Equal(t, fallback.Port, ln.Node().UDP())
+	assert.Equal(t, uint64(4), ln.Node().Seq())
+}