p2p/discover: add node URL functions, distinguish TCP/UDP ports

The discovery RPC protocol does not yet distinguish TCP and UDP ports.
But it can't hurt to do so in our internal model.

8 files changed, 532 insertions, 326 deletions

diff --git a/p2p/discover/node.go b/p2p/discover/node.go
new file mode 100644
index 000000000..a49a2f547
--- /dev/null
+++ b/p2p/discover/node.go
@@ -0,0 +1,289 @@
+package discover
+
+import (
+	"crypto/ecdsa"
+	"crypto/elliptic"
+	"encoding/hex"
+	"errors"
+	"fmt"
+	"io"
+	"math/rand"
+	"net"
+	"net/url"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/ethereum/go-ethereum/crypto/secp256k1"
+	"github.com/ethereum/go-ethereum/rlp"
+)
+
+// Node represents a host on the network.
+type Node struct {
+	ID NodeID
+	IP net.IP
+
+	DiscPort int // UDP listening port for discovery protocol
+	TCPPort  int // TCP listening port for RLPx
+
+	active time.Time
+}
+
+func newNode(id NodeID, addr *net.UDPAddr) *Node {
+	return &Node{
+		ID:       id,
+		IP:       addr.IP,
+		DiscPort: addr.Port,
+		TCPPort:  addr.Port,
+		active:   time.Now(),
+	}
+}
+
+func (n *Node) isValid() bool {
+	// TODO: don't accept localhost, LAN addresses from internet hosts
+	return !n.IP.IsMulticast() && !n.IP.IsUnspecified() && n.TCPPort != 0 && n.DiscPort != 0
+}
+
+// The string representation of a Node is a URL.
+// Please see ParseNode for a description of the format.
+func (n *Node) String() string {
+	addr := net.TCPAddr{IP: n.IP, Port: n.TCPPort}
+	u := url.URL{
+		Scheme: "enode",
+		User:   url.User(fmt.Sprintf("%x", n.ID[:])),
+		Host:   addr.String(),
+	}
+	if n.DiscPort != n.TCPPort {
+		u.RawQuery = "discport=" + strconv.Itoa(n.DiscPort)
+	}
+	return u.String()
+}
+
+// ParseNode parses a node URL.
+//
+// A node URL has scheme "enode".
+//
+// The hexadecimal node ID is encoded in the username portion of the
+// URL, separated from the host by an @ sign. The hostname can only be
+// given as an IP address, DNS domain names are not allowed. The port
+// in the host name section is the TCP listening port. If the TCP and
+// UDP (discovery) ports differ, the UDP port is specified as query
+// parameter "discport".
+//
+// In the following example, the node URL describes
+// a node with IP address 10.3.58.6, TCP listening port 30303
+// and UDP discovery port 30301.
+//
+//    enode://<hex node id>@10.3.58.6:30303?discport=30301
+func ParseNode(rawurl string) (*Node, error) {
+	var n Node
+	u, err := url.Parse(rawurl)
+	if u.Scheme != "enode" {
+		return nil, errors.New("invalid URL scheme, want \"enode\"")
+	}
+	if u.User == nil {
+		return nil, errors.New("does not contain node ID")
+	}
+	if n.ID, err = HexID(u.User.String()); err != nil {
+		return nil, fmt.Errorf("invalid node ID (%v)", err)
+	}
+	ip, port, err := net.SplitHostPort(u.Host)
+	if err != nil {
+		return nil, fmt.Errorf("invalid host: %v", err)
+	}
+	if n.IP = net.ParseIP(ip); n.IP == nil {
+		return nil, errors.New("invalid IP address")
+	}
+	if n.TCPPort, err = strconv.Atoi(port); err != nil {
+		return nil, errors.New("invalid port")
+	}
+	qv := u.Query()
+	if qv.Get("discport") == "" {
+		n.DiscPort = n.TCPPort
+	} else {
+		if n.DiscPort, err = strconv.Atoi(qv.Get("discport")); err != nil {
+			return nil, errors.New("invalid discport in query")
+		}
+	}
+	return &n, nil
+}
+
+// MustParseNode parses a node URL. It panics if the URL is not valid.
+func MustParseNode(rawurl string) *Node {
+	n, err := ParseNode(rawurl)
+	if err != nil {
+		panic("invalid node URL: " + err.Error())
+	}
+	return n
+}
+
+func (n Node) EncodeRLP(w io.Writer) error {
+	return rlp.Encode(w, rpcNode{IP: n.IP.String(), Port: uint16(n.TCPPort), ID: n.ID})
+}
+func (n *Node) DecodeRLP(s *rlp.Stream) (err error) {
+	var ext rpcNode
+	if err = s.Decode(&ext); err == nil {
+		n.TCPPort = int(ext.Port)
+		n.DiscPort = int(ext.Port)
+		n.ID = ext.ID
+		if n.IP = net.ParseIP(ext.IP); n.IP == nil {
+			return errors.New("invalid IP string")
+		}
+	}
+	return err
+}
+
+// NodeID is a unique identifier for each node.
+// The node identifier is a marshaled elliptic curve public key.
+type NodeID [512 / 8]byte
+
+// NodeID prints as a long hexadecimal number.
+func (n NodeID) String() string {
+	return fmt.Sprintf("%#x", n[:])
+}
+
+// The Go syntax representation of a NodeID is a call to HexID.
+func (n NodeID) GoString() string {
+	return fmt.Sprintf("discover.HexID(\"%#x\")", n[:])
+}
+
+// HexID converts a hex string to a NodeID.
+// The string may be prefixed with 0x.
+func HexID(in string) (NodeID, error) {
+	if strings.HasPrefix(in, "0x") {
+		in = in[2:]
+	}
+	var id NodeID
+	b, err := hex.DecodeString(in)
+	if err != nil {
+		return id, err
+	} else if len(b) != len(id) {
+		return id, fmt.Errorf("wrong length, need %d hex bytes", len(id))
+	}
+	copy(id[:], b)
+	return id, nil
+}
+
+// MustHexID converts a hex string to a NodeID.
+// It panics if the string is not a valid NodeID.
+func MustHexID(in string) NodeID {
+	id, err := HexID(in)
+	if err != nil {
+		panic(err)
+	}
+	return id
+}
+
+// PubkeyID returns a marshaled representation of the given public key.
+func PubkeyID(pub *ecdsa.PublicKey) NodeID {
+	var id NodeID
+	pbytes := elliptic.Marshal(pub.Curve, pub.X, pub.Y)
+	if len(pbytes)-1 != len(id) {
+		panic(fmt.Errorf("need %d bit pubkey, got %d bits", (len(id)+1)*8, len(pbytes)))
+	}
+	copy(id[:], pbytes[1:])
+	return id
+}
+
+// recoverNodeID computes the public key used to sign the
+// given hash from the signature.
+func recoverNodeID(hash, sig []byte) (id NodeID, err error) {
+	pubkey, err := secp256k1.RecoverPubkey(hash, sig)
+	if err != nil {
+		return id, err
+	}
+	if len(pubkey)-1 != len(id) {
+		return id, fmt.Errorf("recovered pubkey has %d bits, want %d bits", len(pubkey)*8, (len(id)+1)*8)
+	}
+	for i := range id {
+		id[i] = pubkey[i+1]
+	}
+	return id, nil
+}
+
+// distcmp compares the distances a->target and b->target.
+// Returns -1 if a is closer to target, 1 if b is closer to target
+// and 0 if they are equal.
+func distcmp(target, a, b NodeID) int {
+	for i := range target {
+		da := a[i] ^ target[i]
+		db := b[i] ^ target[i]
+		if da > db {
+			return 1
+		} else if da < db {
+			return -1
+		}
+	}
+	return 0
+}
+
+// table of leading zero counts for bytes [0..255]
+var lzcount = [256]int{
+	8, 7, 6, 6, 5, 5, 5, 5,
+	4, 4, 4, 4, 4, 4, 4, 4,
+	3, 3, 3, 3, 3, 3, 3, 3,
+	3, 3, 3, 3, 3, 3, 3, 3,
+	2, 2, 2, 2, 2, 2, 2, 2,
+	2, 2, 2, 2, 2, 2, 2, 2,
+	2, 2, 2, 2, 2, 2, 2, 2,
+	2, 2, 2, 2, 2, 2, 2, 2,
+	1, 1, 1, 1, 1, 1, 1, 1,
+	1, 1, 1, 1, 1, 1, 1, 1,
+	1, 1, 1, 1, 1, 1, 1, 1,
+	1, 1, 1, 1, 1, 1, 1, 1,
+	1, 1, 1, 1, 1, 1, 1, 1,
+	1, 1, 1, 1, 1, 1, 1, 1,
+	1, 1, 1, 1, 1, 1, 1, 1,
+	1, 1, 1, 1, 1, 1, 1, 1,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+}
+
+// logdist returns the logarithmic distance between a and b, log2(a ^ b).
+func logdist(a, b NodeID) int {
+	lz := 0
+	for i := range a {
+		x := a[i] ^ b[i]
+		if x == 0 {
+			lz += 8
+		} else {
+			lz += lzcount[x]
+			break
+		}
+	}
+	return len(a)*8 - lz
+}
+
+// randomID returns a random NodeID such that logdist(a, b) == n
+func randomID(a NodeID, n int) (b NodeID) {
+	if n == 0 {
+		return a
+	}
+	// flip bit at position n, fill the rest with random bits
+	b = a
+	pos := len(a) - n/8 - 1
+	bit := byte(0x01) << (byte(n%8) - 1)
+	if bit == 0 {
+		pos++
+		bit = 0x80
+	}
+	b[pos] = a[pos]&^bit | ^a[pos]&bit // TODO: randomize end bits
+	for i := pos + 1; i < len(a); i++ {
+		b[i] = byte(rand.Intn(255))
+	}
+	return b
+}
diff --git a/p2p/discover/node_test.go b/p2p/discover/node_test.go
new file mode 100644
index 000000000..ae82ae4f1
--- /dev/null
+++ b/p2p/discover/node_test.go
@@ -0,0 +1,201 @@
+package discover
+
+import (
+	"math/big"
+	"math/rand"
+	"net"
+	"reflect"
+	"testing"
+	"testing/quick"
+	"time"
+
+	"github.com/ethereum/go-ethereum/crypto"
+)
+
+var (
+	quickrand = rand.New(rand.NewSource(time.Now().Unix()))
+	quickcfg  = &quick.Config{MaxCount: 5000, Rand: quickrand}
+)
+
+var parseNodeTests = []struct {
+	rawurl     string
+	wantError  string
+	wantResult *Node
+}{
+	{
+		rawurl:    "http://foobar",
+		wantError: `invalid URL scheme, want "enode"`,
+	},
+	{
+		rawurl:    "enode://foobar",
+		wantError: `does not contain node ID`,
+	},
+	{
+		rawurl:    "enode://01010101@123.124.125.126:3",
+		wantError: `invalid node ID (wrong length, need 64 hex bytes)`,
+	},
+	{
+		rawurl:    "enode://1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439@hostname:3",
+		wantError: `invalid IP address`,
+	},
+	{
+		rawurl:    "enode://1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439@127.0.0.1:foo",
+		wantError: `invalid port`,
+	},
+	{
+		rawurl:    "enode://1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439@127.0.0.1:3?discport=foo",
+		wantError: `invalid discport in query`,
+	},
+	{
+		rawurl: "enode://1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439@127.0.0.1:52150",
+		wantResult: &Node{
+			ID:       MustHexID("0x1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439"),
+			IP:       net.ParseIP("127.0.0.1"),
+			DiscPort: 52150,
+			TCPPort:  52150,
+		},
+	},
+	{
+		rawurl: "enode://1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439@[::]:52150",
+		wantResult: &Node{
+			ID:       MustHexID("0x1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439"),
+			IP:       net.ParseIP("::"),
+			DiscPort: 52150,
+			TCPPort:  52150,
+		},
+	},
+	{
+		rawurl: "enode://1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439@127.0.0.1:52150?discport=223344",
+		wantResult: &Node{
+			ID:       MustHexID("0x1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439"),
+			IP:       net.ParseIP("127.0.0.1"),
+			DiscPort: 223344,
+			TCPPort:  52150,
+		},
+	},
+}
+
+func TestParseNode(t *testing.T) {
+	for i, test := range parseNodeTests {
+		n, err := ParseNode(test.rawurl)
+		if err == nil && test.wantError != "" {
+			t.Errorf("test %d: got nil error, expected %#q", i, test.wantError)
+			continue
+		}
+		if err != nil && err.Error() != test.wantError {
+			t.Errorf("test %d: got error %#q, expected %#q", i, err.Error(), test.wantError)
+			continue
+		}
+		if !reflect.DeepEqual(n, test.wantResult) {
+			t.Errorf("test %d: result mismatch:\ngot:  %#v, want: %#v", i, n, test.wantResult)
+		}
+	}
+}
+
+func TestNodeString(t *testing.T) {
+	for i, test := range parseNodeTests {
+		if test.wantError != "" {
+			continue
+		}
+		str := test.wantResult.String()
+		if str != test.rawurl {
+			t.Errorf("test %d: Node.String() mismatch:\ngot:  %s\nwant: %s", i, str, test.rawurl)
+		}
+	}
+}
+
+func TestHexID(t *testing.T) {
+	ref := NodeID{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 128, 106, 217, 182, 31, 165, 174, 1, 67, 7, 235, 220, 150, 66, 83, 173, 205, 159, 44, 10, 57, 42, 161, 26, 188}
+	id1 := MustHexID("0x000000000000000000000000000000000000000000000000000000000000000000000000000000806ad9b61fa5ae014307ebdc964253adcd9f2c0a392aa11abc")
+	id2 := MustHexID("000000000000000000000000000000000000000000000000000000000000000000000000000000806ad9b61fa5ae014307ebdc964253adcd9f2c0a392aa11abc")
+
+	if id1 != ref {
+		t.Errorf("wrong id1\ngot  %v\nwant %v", id1[:], ref[:])
+	}
+	if id2 != ref {
+		t.Errorf("wrong id2\ngot  %v\nwant %v", id2[:], ref[:])
+	}
+}
+
+func TestNodeID_recover(t *testing.T) {
+	prv := newkey()
+	hash := make([]byte, 32)
+	sig, err := crypto.Sign(hash, prv)
+	if err != nil {
+		t.Fatalf("signing error: %v", err)
+	}
+
+	pub := PubkeyID(&prv.PublicKey)
+	recpub, err := recoverNodeID(hash, sig)
+	if err != nil {
+		t.Fatalf("recovery error: %v", err)
+	}
+	if pub != recpub {
+		t.Errorf("recovered wrong pubkey:\ngot:  %v\nwant: %v", recpub, pub)
+	}
+}
+
+func TestNodeID_distcmp(t *testing.T) {
+	distcmpBig := func(target, a, b NodeID) int {
+		tbig := new(big.Int).SetBytes(target[:])
+		abig := new(big.Int).SetBytes(a[:])
+		bbig := new(big.Int).SetBytes(b[:])
+		return new(big.Int).Xor(tbig, abig).Cmp(new(big.Int).Xor(tbig, bbig))
+	}
+	if err := quick.CheckEqual(distcmp, distcmpBig, quickcfg); err != nil {
+		t.Error(err)
+	}
+}
+
+// the random tests is likely to miss the case where they're equal.
+func TestNodeID_distcmpEqual(t *testing.T) {
+	base := NodeID{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15}
+	x := NodeID{15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0}
+	if distcmp(base, x, x) != 0 {
+		t.Errorf("distcmp(base, x, x) != 0")
+	}
+}
+
+func TestNodeID_logdist(t *testing.T) {
+	logdistBig := func(a, b NodeID) int {
+		abig, bbig := new(big.Int).SetBytes(a[:]), new(big.Int).SetBytes(b[:])
+		return new(big.Int).Xor(abig, bbig).BitLen()
+	}
+	if err := quick.CheckEqual(logdist, logdistBig, quickcfg); err != nil {
+		t.Error(err)
+	}
+}
+
+// the random tests is likely to miss the case where they're equal.
+func TestNodeID_logdistEqual(t *testing.T) {
+	x := NodeID{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15}
+	if logdist(x, x) != 0 {
+		t.Errorf("logdist(x, x) != 0")
+	}
+}
+
+func TestNodeID_randomID(t *testing.T) {
+	// we don't use quick.Check here because its output isn't
+	// very helpful when the test fails.
+	for i := 0; i < quickcfg.MaxCount; i++ {
+		a := gen(NodeID{}, quickrand).(NodeID)
+		dist := quickrand.Intn(len(NodeID{}) * 8)
+		result := randomID(a, dist)
+		actualdist := logdist(result, a)
+
+		if dist != actualdist {
+			t.Log("a:     ", a)
+			t.Log("result:", result)
+			t.Fatalf("#%d: distance of result is %d, want %d", i, actualdist, dist)
+		}
+	}
+}
+
+func (NodeID) Generate(rand *rand.Rand, size int) reflect.Value {
+	var id NodeID
+	m := rand.Intn(len(id))
+	for i := len(id) - 1; i > m; i-- {
+		id[i] = byte(rand.Uint32())
+	}
+	return reflect.ValueOf(id)
+}
diff --git a/p2p/discover/table.go b/p2p/discover/table.go
index ea9680404..6025507eb 100644
--- a/p2p/discover/table.go
+++ b/p2p/discover/table.go
@@ -7,20 +7,10 @@
 package discover
 
 import (
-	"crypto/ecdsa"
-	"crypto/elliptic"
-	"encoding/hex"
-	"fmt"
-	"io"
-	"math/rand"
 	"net"
 	"sort"
-	"strings"
 	"sync"
 	"time"
-
-	"github.com/ethereum/go-ethereum/crypto/secp256k1"
-	"github.com/ethereum/go-ethereum/rlp"
 )
 
 const (
@@ -53,36 +43,10 @@ type bucket struct {
 	entries    []*Node
 }
 
-// Node represents node metadata that is stored in the table.
-type Node struct {
-	Addr *net.UDPAddr
-	ID   NodeID
-
-	active time.Time
-}
-
-type rpcNode struct {
-	IP   string
-	Port uint16
-	ID   NodeID
-}
-
-func (n Node) EncodeRLP(w io.Writer) error {
-	return rlp.Encode(w, rpcNode{IP: n.Addr.IP.String(), Port: uint16(n.Addr.Port), ID: n.ID})
-}
-func (n *Node) DecodeRLP(s *rlp.Stream) (err error) {
-	var ext rpcNode
-	if err = s.Decode(&ext); err == nil {
-		n.Addr = &net.UDPAddr{IP: net.ParseIP(ext.IP), Port: int(ext.Port)}
-		n.ID = ext.ID
-	}
-	return err
-}
-
 func newTable(t transport, ourID NodeID, ourAddr *net.UDPAddr) *Table {
-	tab := &Table{net: t, self: &Node{ID: ourID, Addr: ourAddr}}
+	tab := &Table{net: t, self: newNode(ourID, ourAddr)}
 	for i := range tab.buckets {
-		tab.buckets[i] = &bucket{}
+		tab.buckets[i] = new(bucket)
 	}
 	return tab
 }
@@ -217,7 +181,7 @@ func (tab *Table) len() (n int) {
 func (tab *Table) bumpOrAdd(node NodeID, from *net.UDPAddr) (n *Node) {
 	b := tab.buckets[logdist(tab.self.ID, node)]
 	if n = b.bump(node); n == nil {
-		n = &Node{ID: node, Addr: from, active: time.Now()}
+		n = newNode(node, from)
 		if len(b.entries) == bucketSize {
 			tab.pingReplace(n, b)
 		} else {
@@ -238,6 +202,7 @@ func (tab *Table) pingReplace(n *Node, b *bucket) {
 		tab.mutex.Lock()
 		if len(b.entries) > 0 && b.entries[len(b.entries)-1] == old {
 			// slide down other entries and put the new one in front.
+			// TODO: insert in correct position to keep the order
 			copy(b.entries[1:], b.entries)
 			b.entries[0] = n
 		}
@@ -312,157 +277,3 @@ func (h *nodesByDistance) push(n *Node, maxElems int) {
 		h.entries[ix] = n
 	}
 }
-
-// NodeID is a unique identifier for each node.
-// The node identifier is a marshaled elliptic curve public key.
-type NodeID [512 / 8]byte
-
-// NodeID prints as a long hexadecimal number.
-func (n NodeID) String() string {
-	return fmt.Sprintf("%#x", n[:])
-}
-
-// The Go syntax representation of a NodeID is a call to HexID.
-func (n NodeID) GoString() string {
-	return fmt.Sprintf("HexID(\"%#x\")", n[:])
-}
-
-// HexID converts a hex string to a NodeID.
-// The string may be prefixed with 0x.
-func HexID(in string) (NodeID, error) {
-	if strings.HasPrefix(in, "0x") {
-		in = in[2:]
-	}
-	var id NodeID
-	b, err := hex.DecodeString(in)
-	if err != nil {
-		return id, err
-	} else if len(b) != len(id) {
-		return id, fmt.Errorf("wrong length, need %d hex bytes", len(id))
-	}
-	copy(id[:], b)
-	return id, nil
-}
-
-// MustHexID converts a hex string to a NodeID.
-// It panics if the string is not a valid NodeID.
-func MustHexID(in string) NodeID {
-	id, err := HexID(in)
-	if err != nil {
-		panic(err)
-	}
-	return id
-}
-
-func PubkeyID(pub *ecdsa.PublicKey) NodeID {
-	var id NodeID
-	pbytes := elliptic.Marshal(pub.Curve, pub.X, pub.Y)
-	if len(pbytes)-1 != len(id) {
-		panic(fmt.Errorf("invalid key: need %d bit pubkey, got %d bits", (len(id)+1)*8, len(pbytes)))
-	}
-	copy(id[:], pbytes[1:])
-	return id
-}
-
-// recoverNodeID computes the public key used to sign the
-// given hash from the signature.
-func recoverNodeID(hash, sig []byte) (id NodeID, err error) {
-	pubkey, err := secp256k1.RecoverPubkey(hash, sig)
-	if err != nil {
-		return id, err
-	}
-	if len(pubkey)-1 != len(id) {
-		return id, fmt.Errorf("recovered pubkey has %d bits, want %d bits", len(pubkey)*8, (len(id)+1)*8)
-	}
-	for i := range id {
-		id[i] = pubkey[i+1]
-	}
-	return id, nil
-}
-
-// distcmp compares the distances a->target and b->target.
-// Returns -1 if a is closer to target, 1 if b is closer to target
-// and 0 if they are equal.
-func distcmp(target, a, b NodeID) int {
-	for i := range target {
-		da := a[i] ^ target[i]
-		db := b[i] ^ target[i]
-		if da > db {
-			return 1
-		} else if da < db {
-			return -1
-		}
-	}
-	return 0
-}
-
-// table of leading zero counts for bytes [0..255]
-var lzcount = [256]int{
-	8, 7, 6, 6, 5, 5, 5, 5,
-	4, 4, 4, 4, 4, 4, 4, 4,
-	3, 3, 3, 3, 3, 3, 3, 3,
-	3, 3, 3, 3, 3, 3, 3, 3,
-	2, 2, 2, 2, 2, 2, 2, 2,
-	2, 2, 2, 2, 2, 2, 2, 2,
-	2, 2, 2, 2, 2, 2, 2, 2,
-	2, 2, 2, 2, 2, 2, 2, 2,
-	1, 1, 1, 1, 1, 1, 1, 1,
-	1, 1, 1, 1, 1, 1, 1, 1,
-	1, 1, 1, 1, 1, 1, 1, 1,
-	1, 1, 1, 1, 1, 1, 1, 1,
-	1, 1, 1, 1, 1, 1, 1, 1,
-	1, 1, 1, 1, 1, 1, 1, 1,
-	1, 1, 1, 1, 1, 1, 1, 1,
-	1, 1, 1, 1, 1, 1, 1, 1,
-	0, 0, 0, 0, 0, 0, 0, 0,
-	0, 0, 0, 0, 0, 0, 0, 0,
-	0, 0, 0, 0, 0, 0, 0, 0,
-	0, 0, 0, 0, 0, 0, 0, 0,
-	0, 0, 0, 0, 0, 0, 0, 0,
-	0, 0, 0, 0, 0, 0, 0, 0,
-	0, 0, 0, 0, 0, 0, 0, 0,
-	0, 0, 0, 0, 0, 0, 0, 0,
-	0, 0, 0, 0, 0, 0, 0, 0,
-	0, 0, 0, 0, 0, 0, 0, 0,
-	0, 0, 0, 0, 0, 0, 0, 0,
-	0, 0, 0, 0, 0, 0, 0, 0,
-	0, 0, 0, 0, 0, 0, 0, 0,
-	0, 0, 0, 0, 0, 0, 0, 0,
-	0, 0, 0, 0, 0, 0, 0, 0,
-	0, 0, 0, 0, 0, 0, 0, 0,
-}
-
-// logdist returns the logarithmic distance between a and b, log2(a ^ b).
-func logdist(a, b NodeID) int {
-	lz := 0
-	for i := range a {
-		x := a[i] ^ b[i]
-		if x == 0 {
-			lz += 8
-		} else {
-			lz += lzcount[x]
-			break
-		}
-	}
-	return len(a)*8 - lz
-}
-
-// randomID returns a random NodeID such that logdist(a, b) == n
-func randomID(a NodeID, n int) (b NodeID) {
-	if n == 0 {
-		return a
-	}
-	// flip bit at position n, fill the rest with random bits
-	b = a
-	pos := len(a) - n/8 - 1
-	bit := byte(0x01) << (byte(n%8) - 1)
-	if bit == 0 {
-		pos++
-		bit = 0x80
-	}
-	b[pos] = a[pos]&^bit | ^a[pos]&bit // TODO: randomize end bits
-	for i := pos + 1; i < len(a); i++ {
-		b[i] = byte(rand.Intn(255))
-	}
-	return b
-}
diff --git a/p2p/discover/table_test.go b/p2p/discover/table_test.go
index 90f89b147..9b05ce7f4 100644
--- a/p2p/discover/table_test.go
+++ b/p2p/discover/table_test.go
@@ -4,7 +4,6 @@ import (
 	"crypto/ecdsa"
 	"errors"
 	"fmt"
-	"math/big"
 	"math/rand"
 	"net"
 	"reflect"
@@ -15,107 +14,6 @@ import (
 	"github.com/ethereum/go-ethereum/crypto"
 )
 
-var (
-	quickrand = rand.New(rand.NewSource(time.Now().Unix()))
-	quickcfg  = &quick.Config{MaxCount: 5000, Rand: quickrand}
-)
-
-func TestHexID(t *testing.T) {
-	ref := NodeID{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 128, 106, 217, 182, 31, 165, 174, 1, 67, 7, 235, 220, 150, 66, 83, 173, 205, 159, 44, 10, 57, 42, 161, 26, 188}
-	id1 := MustHexID("0x000000000000000000000000000000000000000000000000000000000000000000000000000000806ad9b61fa5ae014307ebdc964253adcd9f2c0a392aa11abc")
-	id2 := MustHexID("000000000000000000000000000000000000000000000000000000000000000000000000000000806ad9b61fa5ae014307ebdc964253adcd9f2c0a392aa11abc")
-
-	if id1 != ref {
-		t.Errorf("wrong id1\ngot  %v\nwant %v", id1[:], ref[:])
-	}
-	if id2 != ref {
-		t.Errorf("wrong id2\ngot  %v\nwant %v", id2[:], ref[:])
-	}
-}
-
-func TestNodeID_recover(t *testing.T) {
-	prv := newkey()
-	hash := make([]byte, 32)
-	sig, err := crypto.Sign(hash, prv)
-	if err != nil {
-		t.Fatalf("signing error: %v", err)
-	}
-
-	pub := PubkeyID(&prv.PublicKey)
-	recpub, err := recoverNodeID(hash, sig)
-	if err != nil {
-		t.Fatalf("recovery error: %v", err)
-	}
-	if pub != recpub {
-		t.Errorf("recovered wrong pubkey:\ngot:  %v\nwant: %v", recpub, pub)
-	}
-}
-
-func TestNodeID_distcmp(t *testing.T) {
-	distcmpBig := func(target, a, b NodeID) int {
-		tbig := new(big.Int).SetBytes(target[:])
-		abig := new(big.Int).SetBytes(a[:])
-		bbig := new(big.Int).SetBytes(b[:])
-		return new(big.Int).Xor(tbig, abig).Cmp(new(big.Int).Xor(tbig, bbig))
-	}
-	if err := quick.CheckEqual(distcmp, distcmpBig, quickcfg); err != nil {
-		t.Error(err)
-	}
-}
-
-// the random tests is likely to miss the case where they're equal.
-func TestNodeID_distcmpEqual(t *testing.T) {
-	base := NodeID{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15}
-	x := NodeID{15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0}
-	if distcmp(base, x, x) != 0 {
-		t.Errorf("distcmp(base, x, x) != 0")
-	}
-}
-
-func TestNodeID_logdist(t *testing.T) {
-	logdistBig := func(a, b NodeID) int {
-		abig, bbig := new(big.Int).SetBytes(a[:]), new(big.Int).SetBytes(b[:])
-		return new(big.Int).Xor(abig, bbig).BitLen()
-	}
-	if err := quick.CheckEqual(logdist, logdistBig, quickcfg); err != nil {
-		t.Error(err)
-	}
-}
-
-// the random tests is likely to miss the case where they're equal.
-func TestNodeID_logdistEqual(t *testing.T) {
-	x := NodeID{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15}
-	if logdist(x, x) != 0 {
-		t.Errorf("logdist(x, x) != 0")
-	}
-}
-
-func TestNodeID_randomID(t *testing.T) {
-	// we don't use quick.Check here because its output isn't
-	// very helpful when the test fails.
-	for i := 0; i < quickcfg.MaxCount; i++ {
-		a := gen(NodeID{}, quickrand).(NodeID)
-		dist := quickrand.Intn(len(NodeID{}) * 8)
-		result := randomID(a, dist)
-		actualdist := logdist(result, a)
-
-		if dist != actualdist {
-			t.Log("a:     ", a)
-			t.Log("result:", result)
-			t.Fatalf("#%d: distance of result is %d, want %d", i, actualdist, dist)
-		}
-	}
-}
-
-func (NodeID) Generate(rand *rand.Rand, size int) reflect.Value {
-	var id NodeID
-	m := rand.Intn(len(id))
-	for i := len(id) - 1; i > m; i-- {
-		id[i] = byte(rand.Uint32())
-	}
-	return reflect.ValueOf(id)
-}
-
 func TestTable_bumpOrAddPingReplace(t *testing.T) {
 	pingC := make(pingC)
 	tab := newTable(pingC, NodeID{}, &net.UDPAddr{})
@@ -123,7 +21,7 @@ func TestTable_bumpOrAddPingReplace(t *testing.T) {
 
 	// this bumpOrAdd should not replace the last node
 	// because the node replies to ping.
-	new := tab.bumpOrAdd(randomID(tab.self.ID, 200), nil)
+	new := tab.bumpOrAdd(randomID(tab.self.ID, 200), &net.UDPAddr{})
 
 	pinged := <-pingC
 	if pinged != last.ID {
@@ -149,7 +47,7 @@ func TestTable_bumpOrAddPingTimeout(t *testing.T) {
 
 	// this bumpOrAdd should replace the last node
 	// because the node does not reply to ping.
-	new := tab.bumpOrAdd(randomID(tab.self.ID, 200), nil)
+	new := tab.bumpOrAdd(randomID(tab.self.ID, 200), &net.UDPAddr{})
 
 	// wait for async bucket update. damn. this needs to go away.
 	time.Sleep(2 * time.Millisecond)
@@ -329,19 +227,17 @@ type findnodeOracle struct {
 }
 
 func (t findnodeOracle) findnode(n *Node, target NodeID) ([]*Node, error) {
-	t.t.Logf("findnode query at dist %d", n.Addr.Port)
+	t.t.Logf("findnode query at dist %d", n.DiscPort)
 	// current log distance is encoded in port number
 	var result []*Node
-	switch port := n.Addr.Port; port {
+	switch n.DiscPort {
 	case 0:
 		panic("query to node at distance 0")
-	case 1:
-		result = append(result, &Node{ID: t.target, Addr: &net.UDPAddr{Port: 0}})
 	default:
 		// TODO: add more randomness to distances
-		port--
+		next := n.DiscPort - 1
 		for i := 0; i < bucketSize; i++ {
-			result = append(result, &Node{ID: randomID(t.target, port), Addr: &net.UDPAddr{Port: port}})
+			result = append(result, &Node{ID: randomID(t.target, next), DiscPort: next})
 		}
 	}
 	return result, nil
diff --git a/p2p/discover/udp.go b/p2p/discover/udp.go
index 449139c1d..67e349aa4 100644
--- a/p2p/discover/udp.go
+++ b/p2p/discover/udp.go
@@ -69,6 +69,12 @@ type (
 	}
 )
 
+type rpcNode struct {
+	IP   string
+	Port uint16
+	ID   NodeID
+}
+
 // udp implements the RPC protocol.
 type udp struct {
 	conn       *net.UDPConn
@@ -121,7 +127,7 @@ func ListenUDP(priv *ecdsa.PrivateKey, laddr string) (*Table, error) {
 		return nil, err
 	}
 	net.Table = newTable(net, PubkeyID(&priv.PublicKey), realaddr)
-	log.Debugf("Listening on %v, my ID %x\n", realaddr, net.self.ID[:])
+	log.Debugf("Listening, %v\n", net.self)
 	return net.Table, nil
 }
 
@@ -159,8 +165,8 @@ func (t *udp) ping(e *Node) error {
 	// TODO: maybe check for ReplyTo field in callback to measure RTT
 	errc := t.pending(e.ID, pongPacket, func(interface{}) bool { return true })
 	t.send(e, pingPacket, ping{
-		IP:         t.self.Addr.String(),
-		Port:       uint16(t.self.Addr.Port),
+		IP:         t.self.IP.String(),
+		Port:       uint16(t.self.TCPPort),
 		Expiration: uint64(time.Now().Add(expiration).Unix()),
 	})
 	return <-errc
@@ -176,7 +182,7 @@ func (t *udp) findnode(to *Node, target NodeID) ([]*Node, error) {
 		for i := 0; i < len(reply.Nodes); i++ {
 			nreceived++
 			n := reply.Nodes[i]
-			if validAddr(n.Addr) && n.ID != t.self.ID {
+			if n.ID != t.self.ID && n.isValid() {
 				nodes = append(nodes, n)
 			}
 		}
@@ -191,10 +197,6 @@ func (t *udp) findnode(to *Node, target NodeID) ([]*Node, error) {
 	return nodes, err
 }
 
-func validAddr(a *net.UDPAddr) bool {
-	return !a.IP.IsMulticast() && !a.IP.IsUnspecified() && a.Port != 0
-}
-
 // pending adds a reply callback to the pending reply queue.
 // see the documentation of type pending for a detailed explanation.
 func (t *udp) pending(id NodeID, ptype byte, callback func(interface{}) bool) <-chan error {
@@ -302,8 +304,9 @@ func (t *udp) send(to *Node, ptype byte, req interface{}) error {
 	// the future.
 	copy(packet, crypto.Sha3(packet[macSize:]))
 
-	log.DebugDetailf(">>> %v %T %v\n", to.Addr, req, req)
-	if _, err = t.conn.WriteToUDP(packet, to.Addr); err != nil {
+	toaddr := &net.UDPAddr{IP: to.IP, Port: to.DiscPort}
+	log.DebugDetailf(">>> %v %T %v\n", toaddr, req, req)
+	if _, err = t.conn.WriteToUDP(packet, toaddr); err != nil {
 		log.DebugDetailln("UDP send failed:", err)
 	}
 	return err
@@ -365,11 +368,14 @@ func (req *ping) handle(t *udp, from *net.UDPAddr, fromID NodeID, mac []byte) er
 		return errExpired
 	}
 	t.mutex.Lock()
-	// Note: we're ignoring the provided IP/Port right now.
-	e := t.bumpOrAdd(fromID, from)
+	// Note: we're ignoring the provided IP address right now
+	n := t.bumpOrAdd(fromID, from)
+	if req.Port != 0 {
+		n.TCPPort = int(req.Port)
+	}
 	t.mutex.Unlock()
 
-	t.send(e, pongPacket, pong{
+	t.send(n, pongPacket, pong{
 		ReplyTok:   mac,
 		Expiration: uint64(time.Now().Add(expiration).Unix()),
 	})
diff --git a/p2p/discover/udp_test.go b/p2p/discover/udp_test.go
index 8ed6ec9c0..94680d6fc 100644
--- a/p2p/discover/udp_test.go
+++ b/p2p/discover/udp_test.go
@@ -4,6 +4,7 @@ import (
 	logpkg "log"
 	"net"
 	"os"
+	"reflect"
 	"testing"
 	"time"
 
@@ -11,7 +12,7 @@ import (
 )
 
 func init() {
-	logger.AddLogSystem(logger.NewStdLogSystem(os.Stdout, logpkg.LstdFlags, logger.DebugLevel))
+	logger.AddLogSystem(logger.NewStdLogSystem(os.Stdout, logpkg.LstdFlags, logger.ErrorLevel))
 }
 
 func TestUDP_ping(t *testing.T) {
@@ -52,7 +53,7 @@ func TestUDP_findnode(t *testing.T) {
 	defer n1.Close()
 	defer n2.Close()
 
-	entry := &Node{ID: NodeID{1}, Addr: &net.UDPAddr{IP: net.IP{1, 2, 3, 4}, Port: 15}}
+	entry := MustParseNode("enode://9d8a19597e312ef32d76e6b4903bb43d7bcd892d17b769d30b404bd3a4c2dca6c86184b17d0fdeeafe3b01e0e912d990ddc853db3f325d5419f31446543c30be@127.0.0.1:54194")
 	n2.add([]*Node{entry})
 
 	target := randomID(n1.self.ID, 100)
@@ -60,7 +61,7 @@ func TestUDP_findnode(t *testing.T) {
 	if len(result) != 1 {
 		t.Fatalf("wrong number of results: got %d, want 1", len(result))
 	}
-	if result[0].ID != entry.ID {
+	if !reflect.DeepEqual(result[0], entry) {
 		t.Errorf("wrong result: got %v, want %v", result[0], entry)
 	}
 }
@@ -103,8 +104,10 @@ func TestUDP_findnodeMultiReply(t *testing.T) {
 	nodes := make([]*Node, bucketSize)
 	for i := range nodes {
 		nodes[i] = &Node{
-			Addr: &net.UDPAddr{IP: net.IP{1, 2, 3, 4}, Port: i + 1},
-			ID:   randomID(n2.self.ID, i+1),
+			IP:       net.IP{1, 2, 3, 4},
+			DiscPort: i + 1,
+			TCPPort:  i + 1,
+			ID:       randomID(n2.self.ID, i+1),
 		}
 	}
 
diff --git a/p2p/server.go b/p2p/server.go
index 9b8030541..87be97a2f 100644
--- a/p2p/server.go
+++ b/p2p/server.go
@@ -136,7 +136,7 @@ func (srv *Server) PeerCount() int {
 // SuggestPeer creates a connection to the given Node if it
 // is not already connected.
 func (srv *Server) SuggestPeer(ip net.IP, port int, id discover.NodeID) {
-	srv.peerConnect <- &discover.Node{ID: id, Addr: &net.UDPAddr{IP: ip, Port: port}}
+	srv.peerConnect <- &discover.Node{ID: id, IP: ip, TCPPort: port}
 }
 
 // Broadcast sends an RLP-encoded message to all connected peers.
@@ -364,8 +364,9 @@ func (srv *Server) dialLoop() {
 }
 
 func (srv *Server) dialNode(dest *discover.Node) {
-	srvlog.Debugf("Dialing %v\n", dest.Addr)
-	conn, err := srv.Dialer.Dial("tcp", dest.Addr.String())
+	addr := &net.TCPAddr{IP: dest.IP, Port: dest.TCPPort}
+	srvlog.Debugf("Dialing %v\n", dest)
+	conn, err := srv.Dialer.Dial("tcp", addr.String())
 	if err != nil {
 		srvlog.DebugDetailf("dial error: %v", err)
 		return
diff --git a/p2p/server_test.go b/p2p/server_test.go
index a05e01014..89300cf1c 100644
--- a/p2p/server_test.go
+++ b/p2p/server_test.go
@@ -91,8 +91,7 @@ func TestServerDial(t *testing.T) {
 
 	// tell the server to connect
 	tcpAddr := listener.Addr().(*net.TCPAddr)
-	connAddr := &discover.Node{Addr: &net.UDPAddr{IP: tcpAddr.IP, Port: tcpAddr.Port}}
-	srv.peerConnect <- connAddr
+	srv.peerConnect <- &discover.Node{IP: tcpAddr.IP, TCPPort: tcpAddr.Port}
 
 	select {
 	case conn := <-accepted: