123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254 |
- // Copyright 2018 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 discover
- import (
- "bytes"
- "crypto/ecdsa"
- "encoding/hex"
- "errors"
- "fmt"
- "math/rand"
- "net"
- "sort"
- "sync"
- "github.com/ethereum/go-ethereum/crypto"
- "github.com/ethereum/go-ethereum/log"
- "github.com/ethereum/go-ethereum/p2p/enode"
- "github.com/ethereum/go-ethereum/p2p/enr"
- )
- var nullNode *enode.Node
- func init() {
- var r enr.Record
- r.Set(enr.IP{0, 0, 0, 0})
- nullNode = enode.SignNull(&r, enode.ID{})
- }
- func newTestTable(t transport) (*Table, *enode.DB) {
- db, _ := enode.OpenDB("")
- tab, _ := newTable(t, db, nil, log.Root())
- go tab.loop()
- return tab, db
- }
- // nodeAtDistance creates a node for which enode.LogDist(base, n.id) == ld.
- func nodeAtDistance(base enode.ID, ld int, ip net.IP) *node {
- var r enr.Record
- r.Set(enr.IP(ip))
- return wrapNode(enode.SignNull(&r, idAtDistance(base, ld)))
- }
- // nodesAtDistance creates n nodes for which enode.LogDist(base, node.ID()) == ld.
- func nodesAtDistance(base enode.ID, ld int, n int) []*enode.Node {
- results := make([]*enode.Node, n)
- for i := range results {
- results[i] = unwrapNode(nodeAtDistance(base, ld, intIP(i)))
- }
- return results
- }
- func nodesToRecords(nodes []*enode.Node) []*enr.Record {
- records := make([]*enr.Record, len(nodes))
- for i := range nodes {
- records[i] = nodes[i].Record()
- }
- return records
- }
- // idAtDistance returns a random hash such that enode.LogDist(a, b) == n
- func idAtDistance(a enode.ID, n int) (b enode.ID) {
- 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
- }
- func intIP(i int) net.IP {
- return net.IP{byte(i), 0, 2, byte(i)}
- }
- // fillBucket inserts nodes into the given bucket until it is full.
- func fillBucket(tab *Table, n *node) (last *node) {
- ld := enode.LogDist(tab.self().ID(), n.ID())
- b := tab.bucket(n.ID())
- for len(b.entries) < bucketSize {
- b.entries = append(b.entries, nodeAtDistance(tab.self().ID(), ld, intIP(ld)))
- }
- return b.entries[bucketSize-1]
- }
- // fillTable adds nodes the table to the end of their corresponding bucket
- // if the bucket is not full. The caller must not hold tab.mutex.
- func fillTable(tab *Table, nodes []*node) {
- for _, n := range nodes {
- tab.addSeenNode(n)
- }
- }
- type pingRecorder struct {
- mu sync.Mutex
- dead, pinged map[enode.ID]bool
- records map[enode.ID]*enode.Node
- n *enode.Node
- }
- func newPingRecorder() *pingRecorder {
- var r enr.Record
- r.Set(enr.IP{0, 0, 0, 0})
- n := enode.SignNull(&r, enode.ID{})
- return &pingRecorder{
- dead: make(map[enode.ID]bool),
- pinged: make(map[enode.ID]bool),
- records: make(map[enode.ID]*enode.Node),
- n: n,
- }
- }
- // setRecord updates a node record. Future calls to ping and
- // requestENR will return this record.
- func (t *pingRecorder) updateRecord(n *enode.Node) {
- t.mu.Lock()
- defer t.mu.Unlock()
- t.records[n.ID()] = n
- }
- // Stubs to satisfy the transport interface.
- func (t *pingRecorder) Self() *enode.Node { return nullNode }
- func (t *pingRecorder) lookupSelf() []*enode.Node { return nil }
- func (t *pingRecorder) lookupRandom() []*enode.Node { return nil }
- // ping simulates a ping request.
- func (t *pingRecorder) ping(n *enode.Node) (seq uint64, err error) {
- t.mu.Lock()
- defer t.mu.Unlock()
- t.pinged[n.ID()] = true
- if t.dead[n.ID()] {
- return 0, errTimeout
- }
- if t.records[n.ID()] != nil {
- seq = t.records[n.ID()].Seq()
- }
- return seq, nil
- }
- // requestENR simulates an ENR request.
- func (t *pingRecorder) RequestENR(n *enode.Node) (*enode.Node, error) {
- t.mu.Lock()
- defer t.mu.Unlock()
- if t.dead[n.ID()] || t.records[n.ID()] == nil {
- return nil, errTimeout
- }
- return t.records[n.ID()], nil
- }
- func hasDuplicates(slice []*node) bool {
- seen := make(map[enode.ID]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
- }
- // checkNodesEqual checks whether the two given node lists contain the same nodes.
- func checkNodesEqual(got, want []*enode.Node) error {
- if len(got) == len(want) {
- for i := range got {
- if !nodeEqual(got[i], want[i]) {
- goto NotEqual
- }
- }
- }
- return nil
- NotEqual:
- output := new(bytes.Buffer)
- fmt.Fprintf(output, "got %d nodes:\n", len(got))
- for _, n := range got {
- fmt.Fprintf(output, " %v %v\n", n.ID(), n)
- }
- fmt.Fprintf(output, "want %d:\n", len(want))
- for _, n := range want {
- fmt.Fprintf(output, " %v %v\n", n.ID(), n)
- }
- return errors.New(output.String())
- }
- func nodeEqual(n1 *enode.Node, n2 *enode.Node) bool {
- return n1.ID() == n2.ID() && n1.IP().Equal(n2.IP())
- }
- func sortByID(nodes []*enode.Node) {
- sort.Slice(nodes, func(i, j int) bool {
- return string(nodes[i].ID().Bytes()) < string(nodes[j].ID().Bytes())
- })
- }
- func sortedByDistanceTo(distbase enode.ID, slice []*node) bool {
- return sort.SliceIsSorted(slice, func(i, j int) bool {
- return enode.DistCmp(distbase, slice[i].ID(), slice[j].ID()) < 0
- })
- }
- // hexEncPrivkey decodes h as a private key.
- func hexEncPrivkey(h string) *ecdsa.PrivateKey {
- b, err := hex.DecodeString(h)
- if err != nil {
- panic(err)
- }
- key, err := crypto.ToECDSA(b)
- if err != nil {
- panic(err)
- }
- return key
- }
- // hexEncPubkey decodes h as a public key.
- func hexEncPubkey(h string) (ret encPubkey) {
- b, err := hex.DecodeString(h)
- if err != nil {
- panic(err)
- }
- if len(b) != len(ret) {
- panic("invalid length")
- }
- copy(ret[:], b)
- return ret
- }
|