p2p/discv5: added new topic discovery package

1 files changed, 337 insertions, 0 deletions

diff --git a/p2p/discv5/table_test.go b/p2p/discv5/table_test.go
new file mode 100644
index 000000000..b7335540a
--- /dev/null
+++ b/p2p/discv5/table_test.go
@@ -0,0 +1,337 @@
+// 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 (
+	"crypto/ecdsa"
+	"fmt"
+	"math/rand"
+
+	"net"
+	"reflect"
+	"testing"
+	"testing/quick"
+	"time"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/crypto"
+)
+
+type nullTransport struct{}
+
+func (nullTransport) sendPing(remote *Node, remoteAddr *net.UDPAddr) []byte { return []byte{1} }
+func (nullTransport) sendPong(remote *Node, pingHash []byte)                {}
+func (nullTransport) sendFindnode(remote *Node, target NodeID)              {}
+func (nullTransport) sendNeighbours(remote *Node, nodes []*Node)            {}
+func (nullTransport) localAddr() *net.UDPAddr                               { return new(net.UDPAddr) }
+func (nullTransport) Close()                                                {}
+
+// func TestTable_pingReplace(t *testing.T) {
+// 	doit := func(newNodeIsResponding, lastInBucketIsResponding bool) {
+// 		transport := newPingRecorder()
+// 		tab, _ := newTable(transport, NodeID{}, &net.UDPAddr{})
+// 		defer tab.Close()
+// 		pingSender := NewNode(MustHexID("a502af0f59b2aab7746995408c79e9ca312d2793cc997e44fc55eda62f0150bbb8c59a6f9269ba3a081518b62699ee807c7c19c20125ddfccca872608af9e370"), net.IP{}, 99, 99)
+//
+// 		// fill up the sender's bucket.
+// 		last := fillBucket(tab, 253)
+//
+// 		// this call to bond should replace the last node
+// 		// in its bucket if the node is not responding.
+// 		transport.responding[last.ID] = lastInBucketIsResponding
+// 		transport.responding[pingSender.ID] = newNodeIsResponding
+// 		tab.bond(true, pingSender.ID, &net.UDPAddr{}, 0)
+//
+// 		// first ping goes to sender (bonding pingback)
+// 		if !transport.pinged[pingSender.ID] {
+// 			t.Error("table did not ping back sender")
+// 		}
+// 		if newNodeIsResponding {
+// 			// second ping goes to oldest node in bucket
+// 			// to see whether it is still alive.
+// 			if !transport.pinged[last.ID] {
+// 				t.Error("table did not ping last node in bucket")
+// 			}
+// 		}
+//
+// 		tab.mutex.Lock()
+// 		defer tab.mutex.Unlock()
+// 		if l := len(tab.buckets[253].entries); l != bucketSize {
+// 			t.Errorf("wrong bucket size after bond: got %d, want %d", l, bucketSize)
+// 		}
+//
+// 		if lastInBucketIsResponding || !newNodeIsResponding {
+// 			if !contains(tab.buckets[253].entries, last.ID) {
+// 				t.Error("last entry was removed")
+// 			}
+// 			if contains(tab.buckets[253].entries, pingSender.ID) {
+// 				t.Error("new entry was added")
+// 			}
+// 		} else {
+// 			if contains(tab.buckets[253].entries, last.ID) {
+// 				t.Error("last entry was not removed")
+// 			}
+// 			if !contains(tab.buckets[253].entries, pingSender.ID) {
+// 				t.Error("new entry was not added")
+// 			}
+// 		}
+// 	}
+//
+// 	doit(true, true)
+// 	doit(false, true)
+// 	doit(true, false)
+// 	doit(false, false)
+// }
+
+func TestBucket_bumpNoDuplicates(t *testing.T) {
+	t.Parallel()
+	cfg := &quick.Config{
+		MaxCount: 1000,
+		Rand:     rand.New(rand.NewSource(time.Now().Unix())),
+		Values: func(args []reflect.Value, rand *rand.Rand) {
+			// generate a random list of nodes. this will be the content of the bucket.
+			n := rand.Intn(bucketSize-1) + 1
+			nodes := make([]*Node, n)
+			for i := range nodes {
+				nodes[i] = nodeAtDistance(common.Hash{}, 200)
+			}
+			args[0] = reflect.ValueOf(nodes)
+			// generate random bump positions.
+			bumps := make([]int, rand.Intn(100))
+			for i := range bumps {
+				bumps[i] = rand.Intn(len(nodes))
+			}
+			args[1] = reflect.ValueOf(bumps)
+		},
+	}
+
+	prop := func(nodes []*Node, bumps []int) (ok bool) {
+		b := &bucket{entries: make([]*Node, len(nodes))}
+		copy(b.entries, nodes)
+		for i, pos := range bumps {
+			b.bump(b.entries[pos])
+			if hasDuplicates(b.entries) {
+				t.Logf("bucket has duplicates after %d/%d bumps:", i+1, len(bumps))
+				for _, n := range b.entries {
+					t.Logf("  %p", n)
+				}
+				return false
+			}
+		}
+		return true
+	}
+	if err := quick.Check(prop, cfg); err != nil {
+		t.Error(err)
+	}
+}
+
+// fillBucket inserts nodes into the given bucket until
+// it is full. The node's IDs dont correspond to their
+// hashes.
+func fillBucket(tab *Table, ld int) (last *Node) {
+	b := tab.buckets[ld]
+	for len(b.entries) < bucketSize {
+		b.entries = append(b.entries, nodeAtDistance(tab.self.sha, ld))
+	}
+	return b.entries[bucketSize-1]
+}
+
+// nodeAtDistance creates a node for which logdist(base, n.sha) == ld.
+// The node's ID does not correspond to n.sha.
+func nodeAtDistance(base common.Hash, ld int) (n *Node) {
+	n = new(Node)
+	n.sha = hashAtDistance(base, ld)
+	copy(n.ID[:], n.sha[:]) // ensure the node still has a unique ID
+	return n
+}
+
+type pingRecorder struct{ responding, pinged map[NodeID]bool }
+
+func newPingRecorder() *pingRecorder {
+	return &pingRecorder{make(map[NodeID]bool), make(map[NodeID]bool)}
+}
+
+func (t *pingRecorder) findnode(toid NodeID, toaddr *net.UDPAddr, target NodeID) ([]*Node, error) {
+	panic("findnode called on pingRecorder")
+}
+func (t *pingRecorder) close() {}
+func (t *pingRecorder) waitping(from NodeID) error {
+	return nil // remote always pings
+}
+func (t *pingRecorder) ping(toid NodeID, toaddr *net.UDPAddr) error {
+	t.pinged[toid] = true
+	if t.responding[toid] {
+		return nil
+	} else {
+		return errTimeout
+	}
+}
+
+func TestTable_closest(t *testing.T) {
+	t.Parallel()
+
+	test := func(test *closeTest) bool {
+		// for any node table, Target and N
+		tab := newTable(test.Self, &net.UDPAddr{})
+		tab.stuff(test.All)
+
+		// check that doClosest(Target, N) returns nodes
+		result := tab.closest(test.Target, test.N).entries
+		if hasDuplicates(result) {
+			t.Errorf("result contains duplicates")
+			return false
+		}
+		if !sortedByDistanceTo(test.Target, result) {
+			t.Errorf("result is not sorted by distance to target")
+			return false
+		}
+
+		// check that the number of results is min(N, tablen)
+		wantN := test.N
+		if tab.count < test.N {
+			wantN = tab.count
+		}
+		if len(result) != wantN {
+			t.Errorf("wrong number of nodes: got %d, want %d", len(result), wantN)
+			return false
+		} else if len(result) == 0 {
+			return true // no need to check distance
+		}
+
+		// check that the result nodes have minimum distance to target.
+		for _, b := range tab.buckets {
+			for _, n := range b.entries {
+				if contains(result, n.ID) {
+					continue // don't run the check below for nodes in result
+				}
+				farthestResult := result[len(result)-1].sha
+				if distcmp(test.Target, n.sha, farthestResult) < 0 {
+					t.Errorf("table contains node that is closer to target but it's not in result")
+					t.Logf("  Target:          %v", test.Target)
+					t.Logf("  Farthest Result: %v", farthestResult)
+					t.Logf("  ID:              %v", n.ID)
+					return false
+				}
+			}
+		}
+		return true
+	}
+	if err := quick.Check(test, quickcfg()); err != nil {
+		t.Error(err)
+	}
+}
+
+func TestTable_ReadRandomNodesGetAll(t *testing.T) {
+	cfg := &quick.Config{
+		MaxCount: 200,
+		Rand:     rand.New(rand.NewSource(time.Now().Unix())),
+		Values: func(args []reflect.Value, rand *rand.Rand) {
+			args[0] = reflect.ValueOf(make([]*Node, rand.Intn(1000)))
+		},
+	}
+	test := func(buf []*Node) bool {
+		tab := newTable(NodeID{}, &net.UDPAddr{})
+		for i := 0; i < len(buf); i++ {
+			ld := cfg.Rand.Intn(len(tab.buckets))
+			tab.stuff([]*Node{nodeAtDistance(tab.self.sha, ld)})
+		}
+		gotN := tab.readRandomNodes(buf)
+		if gotN != tab.count {
+			t.Errorf("wrong number of nodes, got %d, want %d", gotN, tab.count)
+			return false
+		}
+		if hasDuplicates(buf[:gotN]) {
+			t.Errorf("result contains duplicates")
+			return false
+		}
+		return true
+	}
+	if err := quick.Check(test, cfg); err != nil {
+		t.Error(err)
+	}
+}
+
+type closeTest struct {
+	Self   NodeID
+	Target common.Hash
+	All    []*Node
+	N      int
+}
+
+func (*closeTest) Generate(rand *rand.Rand, size int) reflect.Value {
+	t := &closeTest{
+		Self:   gen(NodeID{}, rand).(NodeID),
+		Target: gen(common.Hash{}, rand).(common.Hash),
+		N:      rand.Intn(bucketSize),
+	}
+	for _, id := range gen([]NodeID{}, rand).([]NodeID) {
+		t.All = append(t.All, &Node{ID: id})
+	}
+	return reflect.ValueOf(t)
+}
+
+func hasDuplicates(slice []*Node) bool {
+	seen := make(map[NodeID]bool)
+	for i, e := range slice {
+		if e == nil {
+			panic(fmt.Sprintf("nil *Node at %d", i))
+		}
+		if seen[e.ID] {
+			return true
+		}
+		seen[e.ID] = true
+	}
+	return false
+}
+
+func sortedByDistanceTo(distbase common.Hash, slice []*Node) bool {
+	var last common.Hash
+	for i, e := range slice {
+		if i > 0 && distcmp(distbase, e.sha, last) < 0 {
+			return false
+		}
+		last = e.sha
+	}
+	return true
+}
+
+func contains(ns []*Node, id NodeID) bool {
+	for _, n := range ns {
+		if n.ID == id {
+			return true
+		}
+	}
+	return false
+}
+
+// gen wraps quick.Value so it's easier to use.
+// it generates a random value of the given value's type.
+func gen(typ interface{}, rand *rand.Rand) interface{} {
+	v, ok := quick.Value(reflect.TypeOf(typ), rand)
+	if !ok {
+		panic(fmt.Sprintf("couldn't generate random value of type %T", typ))
+	}
+	return v.Interface()
+}
+
+func newkey() *ecdsa.PrivateKey {
+	key, err := crypto.GenerateKey()
+	if err != nil {
+		panic("couldn't generate key: " + err.Error())
+	}
+	return key
+}