p2p/discv5: added new topic discovery package

1 files changed, 305 insertions, 0 deletions

diff --git a/p2p/discv5/node_test.go b/p2p/discv5/node_test.go
new file mode 100644
index 000000000..ce4ad9e4d
--- /dev/null
+++ b/p2p/discv5/node_test.go
@@ -0,0 +1,305 @@
+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package discv5
+
+import (
+	"fmt"
+	"math/big"
+	"math/rand"
+	"net"
+	"reflect"
+	"strings"
+	"testing"
+	"testing/quick"
+	"time"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/crypto"
+)
+
+func ExampleNewNode() {
+	id := MustHexID("1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439")
+
+	// Complete nodes contain UDP and TCP endpoints:
+	n1 := NewNode(id, net.ParseIP("2001:db8:3c4d:15::abcd:ef12"), 52150, 30303)
+	fmt.Println("n1:", n1)
+	fmt.Println("n1.Incomplete() ->", n1.Incomplete())
+
+	// An incomplete node can be created by passing zero values
+	// for all parameters except id.
+	n2 := NewNode(id, nil, 0, 0)
+	fmt.Println("n2:", n2)
+	fmt.Println("n2.Incomplete() ->", n2.Incomplete())
+
+	// Output:
+	// n1: enode://1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439@[2001:db8:3c4d:15::abcd:ef12]:30303?discport=52150
+	// n1.Incomplete() -> false
+	// n2: enode://1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439
+	// n2.Incomplete() -> true
+}
+
+var parseNodeTests = []struct {
+	rawurl     string
+	wantError  string
+	wantResult *Node
+}{
+	{
+		rawurl:    "http://foobar",
+		wantError: `invalid URL scheme, want "enode"`,
+	},
+	{
+		rawurl:    "enode://01010101@123.124.125.126:3",
+		wantError: `invalid node ID (wrong length, want 128 hex chars)`,
+	},
+	// Complete nodes with IP address.
+	{
+		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: NewNode(
+			MustHexID("0x1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439"),
+			net.IP{0x7f, 0x0, 0x0, 0x1},
+			52150,
+			52150,
+		),
+	},
+	{
+		rawurl: "enode://1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439@[::]:52150",
+		wantResult: NewNode(
+			MustHexID("0x1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439"),
+			net.ParseIP("::"),
+			52150,
+			52150,
+		),
+	},
+	{
+		rawurl: "enode://1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439@[2001:db8:3c4d:15::abcd:ef12]:52150",
+		wantResult: NewNode(
+			MustHexID("0x1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439"),
+			net.ParseIP("2001:db8:3c4d:15::abcd:ef12"),
+			52150,
+			52150,
+		),
+	},
+	{
+		rawurl: "enode://1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439@127.0.0.1:52150?discport=22334",
+		wantResult: NewNode(
+			MustHexID("0x1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439"),
+			net.IP{0x7f, 0x0, 0x0, 0x1},
+			22334,
+			52150,
+		),
+	},
+	// Incomplete nodes with no address.
+	{
+		rawurl: "1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439",
+		wantResult: NewNode(
+			MustHexID("0x1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439"),
+			nil, 0, 0,
+		),
+	},
+	{
+		rawurl: "enode://1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439",
+		wantResult: NewNode(
+			MustHexID("0x1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439"),
+			nil, 0, 0,
+		),
+	},
+	// Invalid URLs
+	{
+		rawurl:    "01010101",
+		wantError: `invalid node ID (wrong length, want 128 hex chars)`,
+	},
+	{
+		rawurl:    "enode://01010101",
+		wantError: `invalid node ID (wrong length, want 128 hex chars)`,
+	},
+	{
+		// This test checks that errors from url.Parse are handled.
+		rawurl:    "://foo",
+		wantError: `parse ://foo: missing protocol scheme`,
+	},
+}
+
+func TestParseNode(t *testing.T) {
+	for _, test := range parseNodeTests {
+		n, err := ParseNode(test.rawurl)
+		if test.wantError != "" {
+			if err == nil {
+				t.Errorf("test %q:\n  got nil error, expected %#q", test.rawurl, test.wantError)
+				continue
+			} else if err.Error() != test.wantError {
+				t.Errorf("test %q:\n  got error %#q, expected %#q", test.rawurl, err.Error(), test.wantError)
+				continue
+			}
+		} else {
+			if err != nil {
+				t.Errorf("test %q:\n  unexpected error: %v", test.rawurl, err)
+				continue
+			}
+			if !reflect.DeepEqual(n, test.wantResult) {
+				t.Errorf("test %q:\n  result mismatch:\ngot:  %#v, want: %#v", test.rawurl, n, test.wantResult)
+			}
+		}
+	}
+}
+
+func TestNodeString(t *testing.T) {
+	for i, test := range parseNodeTests {
+		if test.wantError == "" && strings.HasPrefix(test.rawurl, "enode://") {
+			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)
+	}
+
+	ecdsa, err := pub.Pubkey()
+	if err != nil {
+		t.Errorf("Pubkey error: %v", err)
+	}
+	if !reflect.DeepEqual(ecdsa, &prv.PublicKey) {
+		t.Errorf("Pubkey mismatch:\n  got:  %#v\n  want: %#v", ecdsa, &prv.PublicKey)
+	}
+}
+
+func TestNodeID_pubkeyBad(t *testing.T) {
+	ecdsa, err := NodeID{}.Pubkey()
+	if err == nil {
+		t.Error("expected error for zero ID")
+	}
+	if ecdsa != nil {
+		t.Error("expected nil result")
+	}
+}
+
+func TestNodeID_distcmp(t *testing.T) {
+	distcmpBig := func(target, a, b common.Hash) 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 := common.Hash{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15}
+	x := common.Hash{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 common.Hash) 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 := common.Hash{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_hashAtDistance(t *testing.T) {
+	// we don't use quick.Check here because its output isn't
+	// very helpful when the test fails.
+	cfg := quickcfg()
+	for i := 0; i < cfg.MaxCount; i++ {
+		a := gen(common.Hash{}, cfg.Rand).(common.Hash)
+		dist := cfg.Rand.Intn(len(common.Hash{}) * 8)
+		result := hashAtDistance(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 quickcfg() *quick.Config {
+	return &quick.Config{
+		MaxCount: 5000,
+		Rand:     rand.New(rand.NewSource(time.Now().Unix())),
+	}
+}
+
+// TODO: The Generate method can be dropped when we require Go >= 1.5
+// because testing/quick learned to generate arrays in 1.5.
+
+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)
+}