path: root/p2p/discv5/table_test.go

// Copyright 2016 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/dexon-foundation/dexon/common"
    "github.com/dexon-foundation/dexon/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
}