p2p/discover: new endpoint format

This commit changes the discovery protocol to use the new "v4" endpoint
format, which allows for separate UDP and TCP ports and makes it
possible to discover the UDP address after NAT.

1 files changed, 53 insertions, 28 deletions

diff --git a/p2p/discover/udp_test.go b/p2p/discover/udp_test.go
index 47e04b85a..378edaaa7 100644
--- a/p2p/discover/udp_test.go
+++ b/p2p/discover/udp_test.go
@@ -23,6 +23,15 @@ func init() {
 	logger.AddLogSystem(logger.NewStdLogSystem(os.Stdout, logpkg.LstdFlags, logger.ErrorLevel))
 }
 
+// shared test variables
+var (
+	futureExp          = uint64(time.Now().Add(10 * time.Hour).Unix())
+	testTarget         = MustHexID("01010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101")
+	testRemote         = rpcEndpoint{IP: net.ParseIP("1.1.1.1").To4(), UDP: 1, TCP: 2}
+	testLocalAnnounced = rpcEndpoint{IP: net.ParseIP("2.2.2.2").To4(), UDP: 3, TCP: 4}
+	testLocal          = rpcEndpoint{IP: net.ParseIP("3.3.3.3").To4(), UDP: 5, TCP: 6}
+)
+
 type udpTest struct {
 	t                   *testing.T
 	pipe                *dgramPipe
@@ -52,8 +61,7 @@ func (test *udpTest) packetIn(wantError error, ptype byte, data packet) error {
 		return test.errorf("packet (%d) encode error: %v", err)
 	}
 	test.sent = append(test.sent, enc)
-	err = data.handle(test.udp, test.remoteaddr, PubkeyID(&test.remotekey.PublicKey), enc[:macSize])
-	if err != wantError {
+	if err = test.udp.handlePacket(test.remoteaddr, enc); err != wantError {
 		return test.errorf("error mismatch: got %q, want %q", err, wantError)
 	}
 	return nil
@@ -90,18 +98,12 @@ func (test *udpTest) errorf(format string, args ...interface{}) error {
 	return err
 }
 
-// shared test variables
-var (
-	futureExp  = uint64(time.Now().Add(10 * time.Hour).Unix())
-	testTarget = MustHexID("01010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101")
-)
-
 func TestUDP_packetErrors(t *testing.T) {
 	test := newUDPTest(t)
 	defer test.table.Close()
 
-	test.packetIn(errExpired, pingPacket, &ping{IP: "foo", Port: 99, Version: Version})
-	test.packetIn(errBadVersion, pingPacket, &ping{IP: "foo", Port: 99, Version: 99, Expiration: futureExp})
+	test.packetIn(errExpired, pingPacket, &ping{From: testRemote, To: testLocalAnnounced, Version: Version})
+	test.packetIn(errBadVersion, pingPacket, &ping{From: testRemote, To: testLocalAnnounced, Version: 99, Expiration: futureExp})
 	test.packetIn(errUnsolicitedReply, pongPacket, &pong{ReplyTok: []byte{}, Expiration: futureExp})
 	test.packetIn(errUnknownNode, findnodePacket, &findnode{Expiration: futureExp})
 	test.packetIn(errUnsolicitedReply, neighborsPacket, &neighbors{Expiration: futureExp})
@@ -147,10 +149,10 @@ func TestUDP_findnode(t *testing.T) {
 	nodes := &nodesByDistance{target: target}
 	for i := 0; i < bucketSize; i++ {
 		nodes.push(&Node{
-			IP:       net.IP{1, 2, 3, byte(i)},
-			DiscPort: i + 2,
-			TCPPort:  i + 2,
-			ID:       randomID(test.table.self.ID, i+2),
+			IP:  net.IP{1, 2, 3, byte(i)},
+			UDP: uint16(i + 2),
+			TCP: uint16(i + 3),
+			ID:  randomID(test.table.self.ID, i+2),
 		}, bucketSize)
 	}
 	test.table.add(nodes.entries)
@@ -158,10 +160,10 @@ func TestUDP_findnode(t *testing.T) {
 	// ensure there's a bond with the test node,
 	// findnode won't be accepted otherwise.
 	test.table.db.updateNode(&Node{
-		ID:       PubkeyID(&test.remotekey.PublicKey),
-		IP:       test.remoteaddr.IP,
-		DiscPort: test.remoteaddr.Port,
-		TCPPort:  99,
+		ID:  PubkeyID(&test.remotekey.PublicKey),
+		IP:  test.remoteaddr.IP,
+		UDP: uint16(test.remoteaddr.Port),
+		TCP: 99,
 	})
 	// check that closest neighbors are returned.
 	test.packetIn(nil, findnodePacket, &findnode{Target: testTarget, Expiration: futureExp})
@@ -204,9 +206,9 @@ func TestUDP_findnodeMultiReply(t *testing.T) {
 
 	// send the reply as two packets.
 	list := []*Node{
-		MustParseNode("enode://ba85011c70bcc5c04d8607d3a0ed29aa6179c092cbdda10d5d32684fb33ed01bd94f588ca8f91ac48318087dcb02eaf36773a7a453f0eedd6742af668097b29c@10.0.1.16:30303"),
+		MustParseNode("enode://ba85011c70bcc5c04d8607d3a0ed29aa6179c092cbdda10d5d32684fb33ed01bd94f588ca8f91ac48318087dcb02eaf36773a7a453f0eedd6742af668097b29c@10.0.1.16:30303?discport=30304"),
 		MustParseNode("enode://81fa361d25f157cd421c60dcc28d8dac5ef6a89476633339c5df30287474520caca09627da18543d9079b5b288698b542d56167aa5c09111e55acdbbdf2ef799@10.0.1.16:30303"),
-		MustParseNode("enode://9bffefd833d53fac8e652415f4973bee289e8b1a5c6c4cbe70abf817ce8a64cee11b823b66a987f51aaa9fba0d6a91b3e6bf0d5a5d1042de8e9eeea057b217f8@10.0.1.36:30301"),
+		MustParseNode("enode://9bffefd833d53fac8e652415f4973bee289e8b1a5c6c4cbe70abf817ce8a64cee11b823b66a987f51aaa9fba0d6a91b3e6bf0d5a5d1042de8e9eeea057b217f8@10.0.1.36:30301?discport=17"),
 		MustParseNode("enode://1b5b4aa662d7cb44a7221bfba67302590b643028197a7d5214790f3bac7aaa4a3241be9e83c09cf1f6c69d007c634faae3dc1b1221793e8446c0b3a09de65960@10.0.1.16:30303"),
 	}
 	test.packetIn(nil, neighborsPacket, &neighbors{Expiration: futureExp, Nodes: list[:2]})
@@ -231,7 +233,8 @@ func TestUDP_successfulPing(t *testing.T) {
 
 	done := make(chan struct{})
 	go func() {
-		test.packetIn(nil, pingPacket, &ping{IP: "foo", Port: 99, Version: Version, Expiration: futureExp})
+		// The remote side sends a ping packet to initiate the exchange.
+		test.packetIn(nil, pingPacket, &ping{From: testRemote, To: testLocalAnnounced, Version: Version, Expiration: futureExp})
 		close(done)
 	}()
 
@@ -239,12 +242,34 @@ func TestUDP_successfulPing(t *testing.T) {
 	test.waitPacketOut(func(p *pong) {
 		pinghash := test.sent[0][:macSize]
 		if !bytes.Equal(p.ReplyTok, pinghash) {
-			t.Errorf("got ReplyTok %x, want %x", p.ReplyTok, pinghash)
+			t.Errorf("got pong.ReplyTok %x, want %x", p.ReplyTok, pinghash)
+		}
+		wantTo := rpcEndpoint{
+			// The mirrored UDP address is the UDP packet sender
+			IP: test.remoteaddr.IP, UDP: uint16(test.remoteaddr.Port),
+			// The mirrored TCP port is the one from the ping packet
+			TCP: testRemote.TCP,
+		}
+		if !reflect.DeepEqual(p.To, wantTo) {
+			t.Errorf("got pong.To %v, want %v", p.To, wantTo)
 		}
 	})
 
 	// remote is unknown, the table pings back.
-	test.waitPacketOut(func(p *ping) error { return nil })
+	test.waitPacketOut(func(p *ping) error {
+		if !reflect.DeepEqual(p.From, test.udp.ourEndpoint) {
+			t.Errorf("got ping.From %v, want %v", p.From, test.udp.ourEndpoint)
+		}
+		wantTo := rpcEndpoint{
+			// The mirrored UDP address is the UDP packet sender.
+			IP: test.remoteaddr.IP, UDP: uint16(test.remoteaddr.Port),
+			TCP: 0,
+		}
+		if !reflect.DeepEqual(p.To, wantTo) {
+			t.Errorf("got ping.To %v, want %v", p.To, wantTo)
+		}
+		return nil
+	})
 	test.packetIn(nil, pongPacket, &pong{Expiration: futureExp})
 
 	// ping should return shortly after getting the pong packet.
@@ -259,11 +284,11 @@ func TestUDP_successfulPing(t *testing.T) {
 	if !bytes.Equal(rnode.IP, test.remoteaddr.IP) {
 		t.Errorf("node has wrong IP: got %v, want: %v", rnode.IP, test.remoteaddr.IP)
 	}
-	if rnode.DiscPort != test.remoteaddr.Port {
-		t.Errorf("node has wrong Port: got %v, want: %v", rnode.DiscPort, test.remoteaddr.Port)
+	if int(rnode.UDP) != test.remoteaddr.Port {
+		t.Errorf("node has wrong UDP port: got %v, want: %v", rnode.UDP, test.remoteaddr.Port)
 	}
-	if rnode.TCPPort != 99 {
-		t.Errorf("node has wrong Port: got %v, want: %v", rnode.TCPPort, 99)
+	if rnode.TCP != testRemote.TCP {
+		t.Errorf("node has wrong TCP port: got %v, want: %v", rnode.TCP, testRemote.TCP)
 	}
 }
 
@@ -327,7 +352,7 @@ func (c *dgramPipe) Close() error {
 }
 
 func (c *dgramPipe) LocalAddr() net.Addr {
-	return &net.UDPAddr{}
+	return &net.UDPAddr{IP: testLocal.IP, Port: int(testLocal.UDP)}
 }
 
 func (c *dgramPipe) waitPacketOut() []byte {