p2p/discv5: add deprecation warning and remove unused code (#20367)

* p2p/discv5: add deprecation warning and remove unused code

* p2p/discv5: remove unused variables

p2p/discv5/README

@@ -0,0 +1,4 @@
+This package is an early prototype of Discovery v5. Do not use this code.
+
+See https://github.com/ethereum/devp2p/blob/master/discv5/discv5.md for the
+current Discovery v5 specification.

p2p/discv5/database.go

@@ -58,12 +58,11 @@ var (
 	nodeDBVersionKey = []byte("version") // Version of the database to flush if changes
 	nodeDBItemPrefix = []byte("n:")      // Identifier to prefix node entries with
 
-	nodeDBDiscoverRoot          = ":discover"
+	nodeDBDiscoverRoot      = ":discover"
-	nodeDBDiscoverPing          = nodeDBDiscoverRoot + ":lastping"
+	nodeDBDiscoverPing      = nodeDBDiscoverRoot + ":lastping"
-	nodeDBDiscoverPong          = nodeDBDiscoverRoot + ":lastpong"
+	nodeDBDiscoverPong      = nodeDBDiscoverRoot + ":lastpong"
-	nodeDBDiscoverFindFails     = nodeDBDiscoverRoot + ":findfail"
+	nodeDBDiscoverFindFails = nodeDBDiscoverRoot + ":findfail"
-	nodeDBDiscoverLocalEndpoint = nodeDBDiscoverRoot + ":localendpoint"
+	nodeDBTopicRegTickets   = ":tickets"
-	nodeDBTopicRegTickets       = ":tickets"
 )
 
 // newNodeDB creates a new node database for storing and retrieving infos about
@@ -311,20 +310,6 @@ func (db *nodeDB) updateFindFails(id NodeID, fails int) error {
 	return db.storeInt64(makeKey(id, nodeDBDiscoverFindFails), int64(fails))
 }
 
-// localEndpoint returns the last local endpoint communicated to the
-// given remote node.
-func (db *nodeDB) localEndpoint(id NodeID) *rpcEndpoint {
-	var ep rpcEndpoint
-	if err := db.fetchRLP(makeKey(id, nodeDBDiscoverLocalEndpoint), &ep); err != nil {
-		return nil
-	}
-	return &ep
-}
-
-func (db *nodeDB) updateLocalEndpoint(id NodeID, ep rpcEndpoint) error {
-	return db.storeRLP(makeKey(id, nodeDBDiscoverLocalEndpoint), &ep)
-}
-
 // querySeeds retrieves random nodes to be used as potential seed nodes
 // for bootstrapping.
 func (db *nodeDB) querySeeds(n int, maxAge time.Duration) []*Node {

p2p/discv5/net.go

@@ -77,14 +77,6 @@ type Network struct {
 	nursery       []*Node
 	nodes         map[NodeID]*Node // tracks active nodes with state != known
 	timeoutTimers map[timeoutEvent]*time.Timer
-
-	// Revalidation queues.
-	// Nodes put on these queues will be pinged eventually.
-	slowRevalidateQueue []*Node
-	fastRevalidateQueue []*Node
-
-	// Buffers for state transition.
-	sendBuf []*ingressPacket
 }
 
 // transport is implemented by the UDP transport.
@@ -104,10 +96,9 @@ type transport interface {
 }
 
 type findnodeQuery struct {
-	remote   *Node
+	remote *Node
-	target   common.Hash
+	target common.Hash
-	reply    chan<- []*Node
+	reply  chan<- []*Node
-	nresults int // counter for received nodes
 }
 
 type topicRegisterReq struct {
@@ -650,10 +641,10 @@ loop:
 	if net.conn != nil {
 		net.conn.Close()
 	}
-	if refreshDone != nil {
+	// TODO: wait for pending refresh.
-		// TODO: wait for pending refresh.
+	// if refreshDone != nil {
-		//<-refreshResults
+	// 	<-refreshResults
-	}
+	// }
 	// Cancel all pending timeouts.
 	for _, timer := range net.timeoutTimers {
 		timer.Stop()

p2p/discv5/net_test.go

@@ -17,7 +17,6 @@
 package discv5
 
 import (
-	"fmt"
 	"net"
 	"testing"
 	"time"
@@ -265,10 +264,6 @@ type preminedTestnet struct {
 	net       *Network
 }
 
-func (tn *preminedTestnet) sendFindnode(to *Node, target NodeID) {
-	panic("sendFindnode called")
-}
-
 func (tn *preminedTestnet) sendFindnodeHash(to *Node, target common.Hash) {
 	// current log distance is encoded in port number
 	// fmt.Println("findnode query at dist", toaddr.Port)
@@ -316,10 +311,6 @@ func (tn *preminedTestnet) sendNeighbours(to *Node, nodes []*Node) {
 	panic("sendNeighbours called")
 }
 
-func (tn *preminedTestnet) sendTopicQuery(to *Node, topic Topic) {
-	panic("sendTopicQuery called")
-}
-
 func (tn *preminedTestnet) sendTopicNodes(to *Node, queryHash common.Hash, nodes []*Node) {
 	panic("sendTopicNodes called")
 }
@@ -334,41 +325,6 @@ func (*preminedTestnet) localAddr() *net.UDPAddr {
 	return &net.UDPAddr{IP: net.ParseIP("10.0.1.1"), Port: 40000}
 }
 
-// mine generates a testnet struct literal with nodes at
-// various distances to the given target.
-func (tn *preminedTestnet) mine(target NodeID) {
-	tn.target = target
-	tn.targetSha = crypto.Keccak256Hash(tn.target[:])
-	found := 0
-	for found < bucketSize*10 {
-		k := newkey()
-		id := PubkeyID(&k.PublicKey)
-		sha := crypto.Keccak256Hash(id[:])
-		ld := logdist(tn.targetSha, sha)
-		if len(tn.dists[ld]) < bucketSize {
-			tn.dists[ld] = append(tn.dists[ld], id)
-			fmt.Println("found ID with ld", ld)
-			found++
-		}
-	}
-	fmt.Println("&preminedTestnet{")
-	fmt.Printf("	target: %#v,\n", tn.target)
-	fmt.Printf("	targetSha: %#v,\n", tn.targetSha)
-	fmt.Printf("	dists: [%d][]NodeID{\n", len(tn.dists))
-	for ld, ns := range &tn.dists {
-		if len(ns) == 0 {
-			continue
-		}
-		fmt.Printf("		%d: []NodeID{\n", ld)
-		for _, n := range ns {
-			fmt.Printf("			MustHexID(\"%x\"),\n", n[:])
-		}
-		fmt.Println("		},")
-	}
-	fmt.Println("	},")
-	fmt.Println("}")
-}
-
 func injectResponse(net *Network, from *Node, ev nodeEvent, packet interface{}) {
 	go net.reqReadPacket(ingressPacket{remoteID: from.ID, remoteAddr: from.addr(), ev: ev, data: packet})
 }

p2p/discv5/node.go

@@ -66,23 +66,6 @@ func (n *Node) addr() *net.UDPAddr {
 	return &net.UDPAddr{IP: n.IP, Port: int(n.UDP)}
 }
 
-func (n *Node) setAddr(a *net.UDPAddr) {
-	n.IP = a.IP
-	if ipv4 := a.IP.To4(); ipv4 != nil {
-		n.IP = ipv4
-	}
-	n.UDP = uint16(a.Port)
-}
-
-// compares the given address against the stored values.
-func (n *Node) addrEqual(a *net.UDPAddr) bool {
-	ip := a.IP
-	if ipv4 := a.IP.To4(); ipv4 != nil {
-		ip = ipv4
-	}
-	return n.UDP == uint16(a.Port) && n.IP.Equal(ip)
-}
-
 // Incomplete returns true for nodes with no IP address.
 func (n *Node) Incomplete() bool {
 	return n.IP == nil
@@ -326,14 +309,6 @@ func (n NodeID) Pubkey() (*ecdsa.PublicKey, error) {
 	return p, nil
 }
 
-func (id NodeID) mustPubkey() ecdsa.PublicKey {
-	pk, err := id.Pubkey()
-	if err != nil {
-		panic(err)
-	}
-	return *pk
-}
-
 // recoverNodeID computes the public key used to sign the
 // given hash from the signature.
 func recoverNodeID(hash, sig []byte) (id NodeID, err error) {

p2p/discv5/ntp.go

@@ -1,126 +0,0 @@
-// 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/>.
-
-// Contains the NTP time drift detection via the SNTP protocol:
-//   https://tools.ietf.org/html/rfc4330
-
-package discv5
-
-import (
-	"fmt"
-	"net"
-	"sort"
-	"strings"
-	"time"
-
-	"github.com/ethereum/go-ethereum/log"
-)
-
-const (
-	ntpPool   = "pool.ntp.org" // ntpPool is the NTP server to query for the current time
-	ntpChecks = 3              // Number of measurements to do against the NTP server
-)
-
-// durationSlice attaches the methods of sort.Interface to []time.Duration,
-// sorting in increasing order.
-type durationSlice []time.Duration
-
-func (s durationSlice) Len() int           { return len(s) }
-func (s durationSlice) Less(i, j int) bool { return s[i] < s[j] }
-func (s durationSlice) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
-
-// checkClockDrift queries an NTP server for clock drifts and warns the user if
-// one large enough is detected.
-func checkClockDrift() {
-	drift, err := sntpDrift(ntpChecks)
-	if err != nil {
-		return
-	}
-	if drift < -driftThreshold || drift > driftThreshold {
-		warning := fmt.Sprintf("System clock seems off by %v, which can prevent network connectivity", drift)
-		howtofix := fmt.Sprintf("Please enable network time synchronisation in system settings")
-		separator := strings.Repeat("-", len(warning))
-
-		log.Warn(separator)
-		log.Warn(warning)
-		log.Warn(howtofix)
-		log.Warn(separator)
-	} else {
-		log.Debug(fmt.Sprintf("Sanity NTP check reported %v drift, all ok", drift))
-	}
-}
-
-// sntpDrift does a naive time resolution against an NTP server and returns the
-// measured drift. This method uses the simple version of NTP. It's not precise
-// but should be fine for these purposes.
-//
-// Note, it executes two extra measurements compared to the number of requested
-// ones to be able to discard the two extremes as outliers.
-func sntpDrift(measurements int) (time.Duration, error) {
-	// Resolve the address of the NTP server
-	addr, err := net.ResolveUDPAddr("udp", ntpPool+":123")
-	if err != nil {
-		return 0, err
-	}
-	// Construct the time request (empty package with only 2 fields set):
-	//   Bits 3-5: Protocol version, 3
-	//   Bits 6-8: Mode of operation, client, 3
-	request := make([]byte, 48)
-	request[0] = 3<<3 | 3
-
-	// Execute each of the measurements
-	drifts := []time.Duration{}
-	for i := 0; i < measurements+2; i++ {
-		// Dial the NTP server and send the time retrieval request
-		conn, err := net.DialUDP("udp", nil, addr)
-		if err != nil {
-			return 0, err
-		}
-		defer conn.Close()
-
-		sent := time.Now()
-		if _, err = conn.Write(request); err != nil {
-			return 0, err
-		}
-		// Retrieve the reply and calculate the elapsed time
-		conn.SetDeadline(time.Now().Add(5 * time.Second))
-
-		reply := make([]byte, 48)
-		if _, err = conn.Read(reply); err != nil {
-			return 0, err
-		}
-		elapsed := time.Since(sent)
-
-		// Reconstruct the time from the reply data
-		sec := uint64(reply[43]) | uint64(reply[42])<<8 | uint64(reply[41])<<16 | uint64(reply[40])<<24
-		frac := uint64(reply[47]) | uint64(reply[46])<<8 | uint64(reply[45])<<16 | uint64(reply[44])<<24
-
-		nanosec := sec*1e9 + (frac*1e9)>>32
-
-		t := time.Date(1900, 1, 1, 0, 0, 0, 0, time.UTC).Add(time.Duration(nanosec)).Local()
-
-		// Calculate the drift based on an assumed answer time of RRT/2
-		drifts = append(drifts, sent.Sub(t)+elapsed/2)
-	}
-	// Calculate average drif (drop two extremities to avoid outliers)
-	sort.Sort(durationSlice(drifts))
-
-	drift := time.Duration(0)
-	for i := 1; i < len(drifts)-1; i++ {
-		drift += drifts[i]
-	}
-	return drift / time.Duration(measurements), nil
-}

p2p/discv5/sim_test.go

@@ -294,15 +294,6 @@ func (s *simulation) launchNode(log bool) *Network {
 	return net
 }
 
-func (s *simulation) dropNode(id NodeID) {
-	s.mu.Lock()
-	n := s.nodes[id]
-	delete(s.nodes, id)
-	s.mu.Unlock()
-
-	n.Close()
-}
-
 type simTransport struct {
 	joinTime   time.Time
 	sender     NodeID
@@ -358,22 +349,6 @@ func (st *simTransport) sendPing(remote *Node, remoteAddr *net.UDPAddr, topics [
 	return hash
 }
 
-func (st *simTransport) sendPong(remote *Node, pingHash []byte) {
-	raddr := remote.addr()
-
-	st.sendPacket(remote.ID, ingressPacket{
-		remoteID:   st.sender,
-		remoteAddr: st.senderAddr,
-		hash:       st.nextHash(),
-		ev:         pongPacket,
-		data: &pong{
-			To:         rpcEndpoint{IP: raddr.IP, UDP: uint16(raddr.Port), TCP: 30303},
-			ReplyTok:   pingHash,
-			Expiration: uint64(time.Now().Unix() + int64(expiration)),
-		},
-	})
-}
-
 func (st *simTransport) sendFindnodeHash(remote *Node, target common.Hash) {
 	st.sendPacket(remote.ID, ingressPacket{
 		remoteID:   st.sender,

p2p/discv5/table.go

@@ -14,12 +14,8 @@
 // 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 implements the RLPx v5 Topic Discovery Protocol.
+// Package discv5 is a prototype implementation of Discvery v5.
-//
+// Deprecated: do not use this package.
-// The Topic Discovery protocol provides a way to find RLPx nodes that
-// can be connected to. It uses a Kademlia-like protocol to maintain a
-// distributed database of the IDs and endpoints of all listening
-// nodes.
 package discv5
 
 import (

p2p/discv5/table_test.go

@@ -31,72 +31,6 @@ import (
 	"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{
@@ -139,17 +73,6 @@ func TestBucket_bumpNoDuplicates(t *testing.T) {
 	}
 }
 
-// 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) {
@@ -159,28 +82,6 @@ func nodeAtDistance(base common.Hash, ld int) (n *Node) {
 	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()
 

p2p/discv5/ticket.go

@@ -22,7 +22,6 @@ import (
 	"fmt"
 	"math"
 	"math/rand"
-	"sort"
 	"time"
 
 	"github.com/ethereum/go-ethereum/common"
@@ -33,8 +32,6 @@ import (
 
 const (
 	ticketTimeBucketLen = time.Minute
-	timeWindow          = 10 // * ticketTimeBucketLen
-	wantTicketsInWindow = 10
 	collectFrequency    = time.Second * 30
 	registerFrequency   = time.Second * 60
 	maxCollectDebt      = 10
@@ -139,7 +136,6 @@ type ticketStore struct {
 
 	lastBucketFetched timeBucket
 	nextTicketCached  *ticketRef
-	nextTicketReg     mclock.AbsTime
 
 	searchTopicMap        map[Topic]searchTopic
 	nextTopicQueryCleanup mclock.AbsTime
@@ -268,57 +264,6 @@ func (s *ticketStore) nextSearchLookup(topic Topic) lookupInfo {
 	return target
 }
 
-// ticketsInWindow returns the tickets of a given topic in the registration window.
-func (s *ticketStore) ticketsInWindow(topic Topic) []ticketRef {
-	// Sanity check that the topic still exists before operating on it
-	if s.tickets[topic] == nil {
-		log.Warn("Listing non-existing discovery tickets", "topic", topic)
-		return nil
-	}
-	// Gather all the tickers in the next time window
-	var tickets []ticketRef
-
-	buckets := s.tickets[topic].buckets
-	for idx := timeBucket(0); idx < timeWindow; idx++ {
-		tickets = append(tickets, buckets[s.lastBucketFetched+idx]...)
-	}
-	log.Trace("Retrieved discovery registration tickets", "topic", topic, "from", s.lastBucketFetched, "tickets", len(tickets))
-	return tickets
-}
-
-func (s *ticketStore) removeExcessTickets(t Topic) {
-	tickets := s.ticketsInWindow(t)
-	if len(tickets) <= wantTicketsInWindow {
-		return
-	}
-	sort.Sort(ticketRefByWaitTime(tickets))
-	for _, r := range tickets[wantTicketsInWindow:] {
-		s.removeTicketRef(r)
-	}
-}
-
-type ticketRefByWaitTime []ticketRef
-
-// Len is the number of elements in the collection.
-func (s ticketRefByWaitTime) Len() int {
-	return len(s)
-}
-
-func (ref ticketRef) waitTime() mclock.AbsTime {
-	return ref.t.regTime[ref.idx] - ref.t.issueTime
-}
-
-// Less reports whether the element with
-// index i should sort before the element with index j.
-func (s ticketRefByWaitTime) Less(i, j int) bool {
-	return s[i].waitTime() < s[j].waitTime()
-}
-
-// Swap swaps the elements with indexes i and j.
-func (s ticketRefByWaitTime) Swap(i, j int) {
-	s[i], s[j] = s[j], s[i]
-}
-
 func (s *ticketStore) addTicketRef(r ticketRef) {
 	topic := r.t.topics[r.idx]
 	tickets := s.tickets[topic]
@@ -565,15 +510,6 @@ func (s *ticketStore) addTicket(localTime mclock.AbsTime, pingHash []byte, ticke
 	}
 }
 
-func (s *ticketStore) getNodeTicket(node *Node) *ticket {
-	if s.nodes[node] == nil {
-		log.Trace("Retrieving node ticket", "node", node.ID, "serial", nil)
-	} else {
-		log.Trace("Retrieving node ticket", "node", node.ID, "serial", s.nodes[node].serial)
-	}
-	return s.nodes[node]
-}
-
 func (s *ticketStore) canQueryTopic(node *Node, topic Topic) bool {
 	qq := s.queriesSent[node]
 	if qq != nil {
@@ -770,12 +706,6 @@ func globalRandRead(b []byte) {
 	}
 }
 
-func (r *topicRadius) isInRadius(addrHash common.Hash) bool {
-	nodePrefix := binary.BigEndian.Uint64(addrHash[0:8])
-	dist := nodePrefix ^ r.topicHashPrefix
-	return dist < r.radius
-}
-
 func (r *topicRadius) chooseLookupBucket(a, b int) int {
 	if a < 0 {
 		a = 0

p2p/discv5/udp.go

@@ -27,7 +27,6 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/log"
-	"github.com/ethereum/go-ethereum/p2p/nat"
 	"github.com/ethereum/go-ethereum/p2p/netutil"
 	"github.com/ethereum/go-ethereum/rlp"
 )
@@ -38,15 +37,12 @@ const Version = 4
 var (
 	errPacketTooSmall = errors.New("too small")
 	errBadPrefix      = errors.New("bad prefix")
-	errTimeout        = errors.New("RPC timeout")
 )
 
 // Timeouts
 const (
 	respTimeout = 500 * time.Millisecond
 	expiration  = 20 * time.Second
-
-	driftThreshold = 10 * time.Second // Allowed clock drift before warning user
 )
 
 // RPC request structures
@@ -187,10 +183,6 @@ func makeEndpoint(addr *net.UDPAddr, tcpPort uint16) rpcEndpoint {
 	return rpcEndpoint{IP: ip, UDP: uint16(addr.Port), TCP: tcpPort}
 }
 
-func (e1 rpcEndpoint) equal(e2 rpcEndpoint) bool {
-	return e1.UDP == e2.UDP && e1.TCP == e2.TCP && e1.IP.Equal(e2.IP)
-}
-
 func nodeFromRPC(sender *net.UDPAddr, rn rpcNode) (*Node, error) {
 	if err := netutil.CheckRelayIP(sender.IP, rn.IP); err != nil {
 		return nil, err
@@ -225,7 +217,6 @@ type udp struct {
 	conn        conn
 	priv        *ecdsa.PrivateKey
 	ourEndpoint rpcEndpoint
-	nat         nat.Interface
 	net         *Network
 }
 
@@ -274,13 +265,6 @@ func (t *udp) sendPing(remote *Node, toaddr *net.UDPAddr, topics []Topic) (hash
 	return hash
 }
 
-func (t *udp) sendFindnode(remote *Node, target NodeID) {
-	t.sendPacket(remote.ID, remote.addr(), byte(findnodePacket), findnode{
-		Target:     target,
-		Expiration: uint64(time.Now().Add(expiration).Unix()),
-	})
-}
-
 func (t *udp) sendNeighbours(remote *Node, results []*Node) {
 	// Send neighbors in chunks with at most maxNeighbors per packet
 	// to stay below the 1280 byte limit.

p2p/discv5/udp_test.go

@@ -1,450 +0,0 @@
-// 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 (
-	"encoding/hex"
-	"errors"
-	"io"
-	"net"
-	"reflect"
-	"sync"
-	"testing"
-
-	"github.com/davecgh/go-spew/spew"
-	"github.com/ethereum/go-ethereum/common"
-	"github.com/ethereum/go-ethereum/crypto"
-	"github.com/ethereum/go-ethereum/rlp"
-)
-
-func init() {
-	spew.Config.DisableMethods = true
-}
-
-// shared test variables
-var (
-	testLocal = rpcEndpoint{IP: net.ParseIP("3.3.3.3").To4(), UDP: 5, TCP: 6}
-)
-
-// type udpTest struct {
-// 	t                   *testing.T
-// 	pipe                *dgramPipe
-// 	table               *Table
-// 	udp                 *udp
-// 	sent                [][]byte
-// 	localkey, remotekey *ecdsa.PrivateKey
-// 	remoteaddr          *net.UDPAddr
-// }
-//
-// func newUDPTest(t *testing.T) *udpTest {
-// 	test := &udpTest{
-// 		t:          t,
-// 		pipe:       newpipe(),
-// 		localkey:   newkey(),
-// 		remotekey:  newkey(),
-// 		remoteaddr: &net.UDPAddr{IP: net.IP{1, 2, 3, 4}, Port: 30303},
-// 	}
-// 	test.table, test.udp, _ = newUDP(test.localkey, test.pipe, nil, "")
-// 	return test
-// }
-//
-// // handles a packet as if it had been sent to the transport.
-// func (test *udpTest) packetIn(wantError error, ptype byte, data packet) error {
-// 	enc, err := encodePacket(test.remotekey, ptype, data)
-// 	if err != nil {
-// 		return test.errorf("packet (%d) encode error: %v", ptype, err)
-// 	}
-// 	test.sent = append(test.sent, enc)
-// 	if err = test.udp.handlePacket(test.remoteaddr, enc); err != wantError {
-// 		return test.errorf("error mismatch: got %q, want %q", err, wantError)
-// 	}
-// 	return nil
-// }
-//
-// // waits for a packet to be sent by the transport.
-// // validate should have type func(*udpTest, X) error, where X is a packet type.
-// func (test *udpTest) waitPacketOut(validate interface{}) error {
-// 	dgram := test.pipe.waitPacketOut()
-// 	p, _, _, err := decodePacket(dgram)
-// 	if err != nil {
-// 		return test.errorf("sent packet decode error: %v", err)
-// 	}
-// 	fn := reflect.ValueOf(validate)
-// 	exptype := fn.Type().In(0)
-// 	if reflect.TypeOf(p) != exptype {
-// 		return test.errorf("sent packet type mismatch, got: %v, want: %v", reflect.TypeOf(p), exptype)
-// 	}
-// 	fn.Call([]reflect.Value{reflect.ValueOf(p)})
-// 	return nil
-// }
-//
-// func (test *udpTest) errorf(format string, args ...interface{}) error {
-// 	_, file, line, ok := runtime.Caller(2) // errorf + waitPacketOut
-// 	if ok {
-// 		file = filepath.Base(file)
-// 	} else {
-// 		file = "???"
-// 		line = 1
-// 	}
-// 	err := fmt.Errorf(format, args...)
-// 	fmt.Printf("\t%s:%d: %v\n", file, line, err)
-// 	test.t.Fail()
-// 	return err
-// }
-//
-// func TestUDP_packetErrors(t *testing.T) {
-// 	test := newUDPTest(t)
-// 	defer test.table.Close()
-//
-// 	test.packetIn(errExpired, pingPacket, &ping{From: testRemote, To: testLocalAnnounced, Version: Version})
-// 	test.packetIn(errUnsolicitedReply, pongPacket, &pong{ReplyTok: []byte{}, Expiration: futureExp})
-// 	test.packetIn(errUnknownNode, findnodePacket, &findnode{Expiration: futureExp})
-// 	test.packetIn(errUnsolicitedReply, neighborsPacket, &neighbors{Expiration: futureExp})
-// }
-//
-// func TestUDP_findnode(t *testing.T) {
-// 	test := newUDPTest(t)
-// 	defer test.table.Close()
-//
-// 	// put a few nodes into the table. their exact
-// 	// distribution shouldn't matter much, although we need to
-// 	// take care not to overflow any bucket.
-// 	targetHash := crypto.Keccak256Hash(testTarget[:])
-// 	nodes := &nodesByDistance{target: targetHash}
-// 	for i := 0; i < bucketSize; i++ {
-// 		nodes.push(nodeAtDistance(test.table.self.sha, i+2), bucketSize)
-// 	}
-// 	test.table.stuff(nodes.entries)
-//
-// 	// ensure there's a bond with the test node,
-// 	// findnode won't be accepted otherwise.
-// 	test.table.db.updateNode(NewNode(
-// 		PubkeyID(&test.remotekey.PublicKey),
-// 		test.remoteaddr.IP,
-// 		uint16(test.remoteaddr.Port),
-// 		99,
-// 	))
-// 	// check that closest neighbors are returned.
-// 	test.packetIn(nil, findnodePacket, &findnode{Target: testTarget, Expiration: futureExp})
-// 	expected := test.table.closest(targetHash, bucketSize)
-//
-// 	waitNeighbors := func(want []*Node) {
-// 		test.waitPacketOut(func(p *neighbors) {
-// 			if len(p.Nodes) != len(want) {
-// 				t.Errorf("wrong number of results: got %d, want %d", len(p.Nodes), bucketSize)
-// 			}
-// 			for i := range p.Nodes {
-// 				if p.Nodes[i].ID != want[i].ID {
-// 					t.Errorf("result mismatch at %d:\n  got:  %v\n  want: %v", i, p.Nodes[i], expected.entries[i])
-// 				}
-// 			}
-// 		})
-// 	}
-// 	waitNeighbors(expected.entries[:maxNeighbors])
-// 	waitNeighbors(expected.entries[maxNeighbors:])
-// }
-//
-// func TestUDP_findnodeMultiReply(t *testing.T) {
-// 	test := newUDPTest(t)
-// 	defer test.table.Close()
-//
-// 	// queue a pending findnode request
-// 	resultc, errc := make(chan []*Node), make(chan error)
-// 	go func() {
-// 		rid := PubkeyID(&test.remotekey.PublicKey)
-// 		ns, err := test.udp.findnode(rid, test.remoteaddr, testTarget)
-// 		if err != nil && len(ns) == 0 {
-// 			errc <- err
-// 		} else {
-// 			resultc <- ns
-// 		}
-// 	}()
-//
-// 	// wait for the findnode to be sent.
-// 	// after it is sent, the transport is waiting for a reply
-// 	test.waitPacketOut(func(p *findnode) {
-// 		if p.Target != testTarget {
-// 			t.Errorf("wrong target: got %v, want %v", p.Target, testTarget)
-// 		}
-// 	})
-//
-// 	// send the reply as two packets.
-// 	list := []*Node{
-// 		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?discport=17"),
-// 		MustParseNode("enode://1b5b4aa662d7cb44a7221bfba67302590b643028197a7d5214790f3bac7aaa4a3241be9e83c09cf1f6c69d007c634faae3dc1b1221793e8446c0b3a09de65960@10.0.1.16:30303"),
-// 	}
-// 	rpclist := make([]rpcNode, len(list))
-// 	for i := range list {
-// 		rpclist[i] = nodeToRPC(list[i])
-// 	}
-// 	test.packetIn(nil, neighborsPacket, &neighbors{Expiration: futureExp, Nodes: rpclist[:2]})
-// 	test.packetIn(nil, neighborsPacket, &neighbors{Expiration: futureExp, Nodes: rpclist[2:]})
-//
-// 	// check that the sent neighbors are all returned by findnode
-// 	select {
-// 	case result := <-resultc:
-// 		if !reflect.DeepEqual(result, list) {
-// 			t.Errorf("neighbors mismatch:\n  got:  %v\n  want: %v", result, list)
-// 		}
-// 	case err := <-errc:
-// 		t.Errorf("findnode error: %v", err)
-// 	case <-time.After(5 * time.Second):
-// 		t.Error("findnode did not return within 5 seconds")
-// 	}
-// }
-//
-// func TestUDP_successfulPing(t *testing.T) {
-// 	test := newUDPTest(t)
-// 	added := make(chan *Node, 1)
-// 	test.table.nodeAddedHook = func(n *Node) { added <- n }
-// 	defer test.table.Close()
-//
-// 	// The remote side sends a ping packet to initiate the exchange.
-// 	go test.packetIn(nil, pingPacket, &ping{From: testRemote, To: testLocalAnnounced, Version: Version, Expiration: futureExp})
-//
-// 	// the ping is replied to.
-// 	test.waitPacketOut(func(p *pong) {
-// 		pinghash := test.sent[0][:macSize]
-// 		if !bytes.Equal(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 {
-// 		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})
-//
-// 	// the node should be added to the table shortly after getting the
-// 	// pong packet.
-// 	select {
-// 	case n := <-added:
-// 		rid := PubkeyID(&test.remotekey.PublicKey)
-// 		if n.ID != rid {
-// 			t.Errorf("node has wrong ID: got %v, want %v", n.ID, rid)
-// 		}
-// 		if !bytes.Equal(n.IP, test.remoteaddr.IP) {
-// 			t.Errorf("node has wrong IP: got %v, want: %v", n.IP, test.remoteaddr.IP)
-// 		}
-// 		if int(n.UDP) != test.remoteaddr.Port {
-// 			t.Errorf("node has wrong UDP port: got %v, want: %v", n.UDP, test.remoteaddr.Port)
-// 		}
-// 		if n.TCP != testRemote.TCP {
-// 			t.Errorf("node has wrong TCP port: got %v, want: %v", n.TCP, testRemote.TCP)
-// 		}
-// 	case <-time.After(2 * time.Second):
-// 		t.Errorf("node was not added within 2 seconds")
-// 	}
-// }
-
-var testPackets = []struct {
-	input      string
-	wantPacket interface{}
-}{
-	{
-		input: "71dbda3a79554728d4f94411e42ee1f8b0d561c10e1e5f5893367948c6a7d70bb87b235fa28a77070271b6c164a2dce8c7e13a5739b53b5e96f2e5acb0e458a02902f5965d55ecbeb2ebb6cabb8b2b232896a36b737666c55265ad0a68412f250001ea04cb847f000001820cfa8215a8d790000000000000000000000000000000018208ae820d058443b9a355",
-		wantPacket: &ping{
-			Version:    4,
-			From:       rpcEndpoint{net.ParseIP("127.0.0.1").To4(), 3322, 5544},
-			To:         rpcEndpoint{net.ParseIP("::1"), 2222, 3333},
-			Expiration: 1136239445,
-			Rest:       []rlp.RawValue{},
-		},
-	},
-	{
-		input: "e9614ccfd9fc3e74360018522d30e1419a143407ffcce748de3e22116b7e8dc92ff74788c0b6663aaa3d67d641936511c8f8d6ad8698b820a7cf9e1be7155e9a241f556658c55428ec0563514365799a4be2be5a685a80971ddcfa80cb422cdd0101ec04cb847f000001820cfa8215a8d790000000000000000000000000000000018208ae820d058443b9a3550102",
-		wantPacket: &ping{
-			Version:    4,
-			From:       rpcEndpoint{net.ParseIP("127.0.0.1").To4(), 3322, 5544},
-			To:         rpcEndpoint{net.ParseIP("::1"), 2222, 3333},
-			Expiration: 1136239445,
-			Rest:       []rlp.RawValue{{0x01}, {0x02}},
-		},
-	},
-	{
-		input: "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",
-		wantPacket: &ping{
-			Version:    555,
-			From:       rpcEndpoint{net.ParseIP("2001:db8:3c4d:15::abcd:ef12"), 3322, 5544},
-			To:         rpcEndpoint{net.ParseIP("2001:db8:85a3:8d3:1319:8a2e:370:7348"), 2222, 33338},
-			Expiration: 1136239445,
-			Rest:       []rlp.RawValue{{0xC5, 0x01, 0x02, 0x03, 0x04, 0x05}},
-		},
-	},
-	{
-		input: "09b2428d83348d27cdf7064ad9024f526cebc19e4958f0fdad87c15eb598dd61d08423e0bf66b2069869e1724125f820d851c136684082774f870e614d95a2855d000f05d1648b2d5945470bc187c2d2216fbe870f43ed0909009882e176a46b0102f846d79020010db885a308d313198a2e037073488208ae82823aa0fbc914b16819237dcd8801d7e53f69e9719adecb3cc0e790c57e91ca4461c9548443b9a355c6010203c2040506a0c969a58f6f9095004c0177a6b47f451530cab38966a25cca5cb58f055542124e",
-		wantPacket: &pong{
-			To:         rpcEndpoint{net.ParseIP("2001:db8:85a3:8d3:1319:8a2e:370:7348"), 2222, 33338},
-			ReplyTok:   common.Hex2Bytes("fbc914b16819237dcd8801d7e53f69e9719adecb3cc0e790c57e91ca4461c954"),
-			Expiration: 1136239445,
-			Rest:       []rlp.RawValue{{0xC6, 0x01, 0x02, 0x03, 0xC2, 0x04, 0x05}, {0x06}},
-		},
-	},
-	{
-		input: "c7c44041b9f7c7e41934417ebac9a8e1a4c6298f74553f2fcfdcae6ed6fe53163eb3d2b52e39fe91831b8a927bf4fc222c3902202027e5e9eb812195f95d20061ef5cd31d502e47ecb61183f74a504fe04c51e73df81f25c4d506b26db4517490103f84eb840ca634cae0d49acb401d8a4c6b6fe8c55b70d115bf400769cc1400f3258cd31387574077f301b421bc84df7266c44e9e6d569fc56be00812904767bf5ccd1fc7f8443b9a35582999983999999280dc62cc8255c73471e0a61da0c89acdc0e035e260add7fc0c04ad9ebf3919644c91cb247affc82b69bd2ca235c71eab8e49737c937a2c396",
-		wantPacket: &findnode{
-			Target:     MustHexID("ca634cae0d49acb401d8a4c6b6fe8c55b70d115bf400769cc1400f3258cd31387574077f301b421bc84df7266c44e9e6d569fc56be00812904767bf5ccd1fc7f"),
-			Expiration: 1136239445,
-			Rest:       []rlp.RawValue{{0x82, 0x99, 0x99}, {0x83, 0x99, 0x99, 0x99}},
-		},
-	},
-	{
-		input: "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",
-		wantPacket: &neighbors{
-			Nodes: []rpcNode{
-				{
-					ID:  MustHexID("3155e1427f85f10a5c9a7755877748041af1bcd8d474ec065eb33df57a97babf54bfd2103575fa829115d224c523596b401065a97f74010610fce76382c0bf32"),
-					IP:  net.ParseIP("99.33.22.55").To4(),
-					UDP: 4444,
-					TCP: 4445,
-				},
-				{
-					ID:  MustHexID("312c55512422cf9b8a4097e9a6ad79402e87a15ae909a4bfefa22398f03d20951933beea1e4dfa6f968212385e829f04c2d314fc2d4e255e0d3bc08792b069db"),
-					IP:  net.ParseIP("1.2.3.4").To4(),
-					UDP: 1,
-					TCP: 1,
-				},
-				{
-					ID:  MustHexID("38643200b172dcfef857492156971f0e6aa2c538d8b74010f8e140811d53b98c765dd2d96126051913f44582e8c199ad7c6d6819e9a56483f637feaac9448aac"),
-					IP:  net.ParseIP("2001:db8:3c4d:15::abcd:ef12"),
-					UDP: 3333,
-					TCP: 3333,
-				},
-				{
-					ID:  MustHexID("8dcab8618c3253b558d459da53bd8fa68935a719aff8b811197101a4b2b47dd2d47295286fc00cc081bb542d760717d1bdd6bec2c37cd72eca367d6dd3b9df73"),
-					IP:  net.ParseIP("2001:db8:85a3:8d3:1319:8a2e:370:7348"),
-					UDP: 999,
-					TCP: 1000,
-				},
-			},
-			Expiration: 1136239445,
-			Rest:       []rlp.RawValue{{0x01}, {0x02}, {0x03}},
-		},
-	},
-}
-
-func TestForwardCompatibility(t *testing.T) {
-	t.Skip("skipped while working on discovery v5")
-
-	testkey, _ := crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
-	wantNodeID := PubkeyID(&testkey.PublicKey)
-
-	for _, test := range testPackets {
-		input, err := hex.DecodeString(test.input)
-		if err != nil {
-			t.Fatalf("invalid hex: %s", test.input)
-		}
-		var pkt ingressPacket
-		if err := decodePacket(input, &pkt); err != nil {
-			t.Errorf("did not accept packet %s\n%v", test.input, err)
-			continue
-		}
-		if !reflect.DeepEqual(pkt.data, test.wantPacket) {
-			t.Errorf("got %s\nwant %s", spew.Sdump(pkt.data), spew.Sdump(test.wantPacket))
-		}
-		if pkt.remoteID != wantNodeID {
-			t.Errorf("got id %v\nwant id %v", pkt.remoteID, wantNodeID)
-		}
-	}
-}
-
-// dgramPipe is a fake UDP socket. It queues all sent datagrams.
-type dgramPipe struct {
-	mu      *sync.Mutex
-	cond    *sync.Cond
-	closing chan struct{}
-	closed  bool
-	queue   [][]byte
-}
-
-func newpipe() *dgramPipe {
-	mu := new(sync.Mutex)
-	return &dgramPipe{
-		closing: make(chan struct{}),
-		cond:    &sync.Cond{L: mu},
-		mu:      mu,
-	}
-}
-
-// WriteToUDP queues a datagram.
-func (c *dgramPipe) WriteToUDP(b []byte, to *net.UDPAddr) (n int, err error) {
-	msg := make([]byte, len(b))
-	copy(msg, b)
-	c.mu.Lock()
-	defer c.mu.Unlock()
-	if c.closed {
-		return 0, errors.New("closed")
-	}
-	c.queue = append(c.queue, msg)
-	c.cond.Signal()
-	return len(b), nil
-}
-
-// ReadFromUDP just hangs until the pipe is closed.
-func (c *dgramPipe) ReadFromUDP(b []byte) (n int, addr *net.UDPAddr, err error) {
-	<-c.closing
-	return 0, nil, io.EOF
-}
-
-func (c *dgramPipe) Close() error {
-	c.mu.Lock()
-	defer c.mu.Unlock()
-	if !c.closed {
-		close(c.closing)
-		c.closed = true
-	}
-	return nil
-}
-
-func (c *dgramPipe) LocalAddr() net.Addr {
-	return &net.UDPAddr{IP: testLocal.IP, Port: int(testLocal.UDP)}
-}
-
-func (c *dgramPipe) waitPacketOut() []byte {
-	c.mu.Lock()
-	defer c.mu.Unlock()
-	for len(c.queue) == 0 {
-		c.cond.Wait()
-	}
-	p := c.queue[0]
-	copy(c.queue, c.queue[1:])
-	c.queue = c.queue[:len(c.queue)-1]
-	return p
-}